^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1) acpi= [HW,ACPI,X86,ARM64]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2) Advanced Configuration and Power Interface
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3) Format: { force | on | off | strict | noirq | rsdt |
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4) copy_dsdt }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5) force -- enable ACPI if default was off
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6) on -- enable ACPI but allow fallback to DT [arm64]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 7) off -- disable ACPI if default was on
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 8) noirq -- do not use ACPI for IRQ routing
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 9) strict -- Be less tolerant of platforms that are not
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 10) strictly ACPI specification compliant.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 11) rsdt -- prefer RSDT over (default) XSDT
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 12) copy_dsdt -- copy DSDT to memory
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 13) For ARM64, ONLY "acpi=off", "acpi=on" or "acpi=force"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 14) are available
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 15)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 16) See also Documentation/power/runtime_pm.rst, pci=noacpi
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 17)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 18) acpi_apic_instance= [ACPI, IOAPIC]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 19) Format: <int>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 20) 2: use 2nd APIC table, if available
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 21) 1,0: use 1st APIC table
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 22) default: 0
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 23)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 24) acpi_backlight= [HW,ACPI]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 25) { vendor | video | native | none }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 26) If set to vendor, prefer vendor-specific driver
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 27) (e.g. thinkpad_acpi, sony_acpi, etc.) instead
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 28) of the ACPI video.ko driver.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 29) If set to video, use the ACPI video.ko driver.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 30) If set to native, use the device's native backlight mode.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 31) If set to none, disable the ACPI backlight interface.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 32)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 33) acpi_force_32bit_fadt_addr
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 34) force FADT to use 32 bit addresses rather than the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 35) 64 bit X_* addresses. Some firmware have broken 64
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 36) bit addresses for force ACPI ignore these and use
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 37) the older legacy 32 bit addresses.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 38)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 39) acpica_no_return_repair [HW, ACPI]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 40) Disable AML predefined validation mechanism
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 41) This mechanism can repair the evaluation result to make
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 42) the return objects more ACPI specification compliant.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 43) This option is useful for developers to identify the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 44) root cause of an AML interpreter issue when the issue
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 45) has something to do with the repair mechanism.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 46)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 47) acpi.debug_layer= [HW,ACPI,ACPI_DEBUG]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 48) acpi.debug_level= [HW,ACPI,ACPI_DEBUG]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 49) Format: <int>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 50) CONFIG_ACPI_DEBUG must be enabled to produce any ACPI
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 51) debug output. Bits in debug_layer correspond to a
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 52) _COMPONENT in an ACPI source file, e.g.,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 53) #define _COMPONENT ACPI_PCI_COMPONENT
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 54) Bits in debug_level correspond to a level in
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 55) ACPI_DEBUG_PRINT statements, e.g.,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 56) ACPI_DEBUG_PRINT((ACPI_DB_INFO, ...
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 57) The debug_level mask defaults to "info". See
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 58) Documentation/firmware-guide/acpi/debug.rst for more information about
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 59) debug layers and levels.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 60)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 61) Enable processor driver info messages:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 62) acpi.debug_layer=0x20000000
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 63) Enable PCI/PCI interrupt routing info messages:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 64) acpi.debug_layer=0x400000
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 65) Enable AML "Debug" output, i.e., stores to the Debug
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 66) object while interpreting AML:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 67) acpi.debug_layer=0xffffffff acpi.debug_level=0x2
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 68) Enable all messages related to ACPI hardware:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 69) acpi.debug_layer=0x2 acpi.debug_level=0xffffffff
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 70)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 71) Some values produce so much output that the system is
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 72) unusable. The "log_buf_len" parameter may be useful
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 73) if you need to capture more output.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 74)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 75) acpi_enforce_resources= [ACPI]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 76) { strict | lax | no }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 77) Check for resource conflicts between native drivers
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 78) and ACPI OperationRegions (SystemIO and SystemMemory
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 79) only). IO ports and memory declared in ACPI might be
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 80) used by the ACPI subsystem in arbitrary AML code and
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 81) can interfere with legacy drivers.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 82) strict (default): access to resources claimed by ACPI
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 83) is denied; legacy drivers trying to access reserved
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 84) resources will fail to bind to device using them.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 85) lax: access to resources claimed by ACPI is allowed;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 86) legacy drivers trying to access reserved resources
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 87) will bind successfully but a warning message is logged.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 88) no: ACPI OperationRegions are not marked as reserved,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 89) no further checks are performed.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 90)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 91) acpi_force_table_verification [HW,ACPI]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 92) Enable table checksum verification during early stage.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 93) By default, this is disabled due to x86 early mapping
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 94) size limitation.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 95)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 96) acpi_irq_balance [HW,ACPI]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 97) ACPI will balance active IRQs
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 98) default in APIC mode
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 99)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 100) acpi_irq_nobalance [HW,ACPI]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 101) ACPI will not move active IRQs (default)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 102) default in PIC mode
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 103)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 104) acpi_irq_isa= [HW,ACPI] If irq_balance, mark listed IRQs used by ISA
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 105) Format: <irq>,<irq>...
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 106)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 107) acpi_irq_pci= [HW,ACPI] If irq_balance, clear listed IRQs for
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 108) use by PCI
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 109) Format: <irq>,<irq>...
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 110)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 111) acpi_mask_gpe= [HW,ACPI]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 112) Due to the existence of _Lxx/_Exx, some GPEs triggered
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 113) by unsupported hardware/firmware features can result in
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 114) GPE floodings that cannot be automatically disabled by
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 115) the GPE dispatcher.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 116) This facility can be used to prevent such uncontrolled
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 117) GPE floodings.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 118) Format: <byte>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 119)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 120) acpi_no_auto_serialize [HW,ACPI]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 121) Disable auto-serialization of AML methods
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 122) AML control methods that contain the opcodes to create
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 123) named objects will be marked as "Serialized" by the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 124) auto-serialization feature.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 125) This feature is enabled by default.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 126) This option allows to turn off the feature.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 127)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 128) acpi_no_memhotplug [ACPI] Disable memory hotplug. Useful for kdump
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 129) kernels.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 130)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 131) acpi_no_static_ssdt [HW,ACPI]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 132) Disable installation of static SSDTs at early boot time
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 133) By default, SSDTs contained in the RSDT/XSDT will be
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 134) installed automatically and they will appear under
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 135) /sys/firmware/acpi/tables.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 136) This option turns off this feature.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 137) Note that specifying this option does not affect
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 138) dynamic table installation which will install SSDT
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 139) tables to /sys/firmware/acpi/tables/dynamic.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 140)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 141) acpi_no_watchdog [HW,ACPI,WDT]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 142) Ignore the ACPI-based watchdog interface (WDAT) and let
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 143) a native driver control the watchdog device instead.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 144)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 145) acpi_rsdp= [ACPI,EFI,KEXEC]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 146) Pass the RSDP address to the kernel, mostly used
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 147) on machines running EFI runtime service to boot the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 148) second kernel for kdump.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 149)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 150) acpi_os_name= [HW,ACPI] Tell ACPI BIOS the name of the OS
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 151) Format: To spoof as Windows 98: ="Microsoft Windows"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 152)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 153) acpi_rev_override [ACPI] Override the _REV object to return 5 (instead
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 154) of 2 which is mandated by ACPI 6) as the supported ACPI
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 155) specification revision (when using this switch, it may
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 156) be necessary to carry out a cold reboot _twice_ in a
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 157) row to make it take effect on the platform firmware).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 158)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 159) acpi_osi= [HW,ACPI] Modify list of supported OS interface strings
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 160) acpi_osi="string1" # add string1
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 161) acpi_osi="!string2" # remove string2
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 162) acpi_osi=!* # remove all strings
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 163) acpi_osi=! # disable all built-in OS vendor
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 164) strings
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 165) acpi_osi=!! # enable all built-in OS vendor
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 166) strings
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 167) acpi_osi= # disable all strings
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 168)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 169) 'acpi_osi=!' can be used in combination with single or
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 170) multiple 'acpi_osi="string1"' to support specific OS
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 171) vendor string(s). Note that such command can only
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 172) affect the default state of the OS vendor strings, thus
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 173) it cannot affect the default state of the feature group
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 174) strings and the current state of the OS vendor strings,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 175) specifying it multiple times through kernel command line
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 176) is meaningless. This command is useful when one do not
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 177) care about the state of the feature group strings which
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 178) should be controlled by the OSPM.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 179) Examples:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 180) 1. 'acpi_osi=! acpi_osi="Windows 2000"' is equivalent
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 181) to 'acpi_osi="Windows 2000" acpi_osi=!', they all
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 182) can make '_OSI("Windows 2000")' TRUE.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 183)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 184) 'acpi_osi=' cannot be used in combination with other
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 185) 'acpi_osi=' command lines, the _OSI method will not
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 186) exist in the ACPI namespace. NOTE that such command can
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 187) only affect the _OSI support state, thus specifying it
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 188) multiple times through kernel command line is also
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 189) meaningless.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 190) Examples:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 191) 1. 'acpi_osi=' can make 'CondRefOf(_OSI, Local1)'
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 192) FALSE.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 193)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 194) 'acpi_osi=!*' can be used in combination with single or
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 195) multiple 'acpi_osi="string1"' to support specific
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 196) string(s). Note that such command can affect the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 197) current state of both the OS vendor strings and the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 198) feature group strings, thus specifying it multiple times
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 199) through kernel command line is meaningful. But it may
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 200) still not able to affect the final state of a string if
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 201) there are quirks related to this string. This command
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 202) is useful when one want to control the state of the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 203) feature group strings to debug BIOS issues related to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 204) the OSPM features.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 205) Examples:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 206) 1. 'acpi_osi="Module Device" acpi_osi=!*' can make
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 207) '_OSI("Module Device")' FALSE.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 208) 2. 'acpi_osi=!* acpi_osi="Module Device"' can make
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 209) '_OSI("Module Device")' TRUE.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 210) 3. 'acpi_osi=! acpi_osi=!* acpi_osi="Windows 2000"' is
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 211) equivalent to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 212) 'acpi_osi=!* acpi_osi=! acpi_osi="Windows 2000"'
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 213) and
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 214) 'acpi_osi=!* acpi_osi="Windows 2000" acpi_osi=!',
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 215) they all will make '_OSI("Windows 2000")' TRUE.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 216)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 217) acpi_pm_good [X86]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 218) Override the pmtimer bug detection: force the kernel
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 219) to assume that this machine's pmtimer latches its value
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 220) and always returns good values.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 221)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 222) acpi_sci= [HW,ACPI] ACPI System Control Interrupt trigger mode
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 223) Format: { level | edge | high | low }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 224)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 225) acpi_skip_timer_override [HW,ACPI]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 226) Recognize and ignore IRQ0/pin2 Interrupt Override.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 227) For broken nForce2 BIOS resulting in XT-PIC timer.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 228)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 229) acpi_sleep= [HW,ACPI] Sleep options
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 230) Format: { s3_bios, s3_mode, s3_beep, s4_nohwsig,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 231) old_ordering, nonvs, sci_force_enable, nobl }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 232) See Documentation/power/video.rst for information on
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 233) s3_bios and s3_mode.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 234) s3_beep is for debugging; it makes the PC's speaker beep
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 235) as soon as the kernel's real-mode entry point is called.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 236) s4_nohwsig prevents ACPI hardware signature from being
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 237) used during resume from hibernation.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 238) old_ordering causes the ACPI 1.0 ordering of the _PTS
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 239) control method, with respect to putting devices into
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 240) low power states, to be enforced (the ACPI 2.0 ordering
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 241) of _PTS is used by default).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 242) nonvs prevents the kernel from saving/restoring the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 243) ACPI NVS memory during suspend/hibernation and resume.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 244) sci_force_enable causes the kernel to set SCI_EN directly
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 245) on resume from S1/S3 (which is against the ACPI spec,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 246) but some broken systems don't work without it).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 247) nobl causes the internal blacklist of systems known to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 248) behave incorrectly in some ways with respect to system
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 249) suspend and resume to be ignored (use wisely).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 250)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 251) acpi_use_timer_override [HW,ACPI]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 252) Use timer override. For some broken Nvidia NF5 boards
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 253) that require a timer override, but don't have HPET
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 254)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 255) add_efi_memmap [EFI; X86] Include EFI memory map in
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 256) kernel's map of available physical RAM.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 257)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 258) agp= [AGP]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 259) { off | try_unsupported }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 260) off: disable AGP support
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 261) try_unsupported: try to drive unsupported chipsets
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 262) (may crash computer or cause data corruption)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 263)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 264) ALSA [HW,ALSA]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 265) See Documentation/sound/alsa-configuration.rst
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 266)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 267) alignment= [KNL,ARM]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 268) Allow the default userspace alignment fault handler
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 269) behaviour to be specified. Bit 0 enables warnings,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 270) bit 1 enables fixups, and bit 2 sends a segfault.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 271)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 272) align_va_addr= [X86-64]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 273) Align virtual addresses by clearing slice [14:12] when
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 274) allocating a VMA at process creation time. This option
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 275) gives you up to 3% performance improvement on AMD F15h
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 276) machines (where it is enabled by default) for a
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 277) CPU-intensive style benchmark, and it can vary highly in
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 278) a microbenchmark depending on workload and compiler.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 279)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 280) 32: only for 32-bit processes
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 281) 64: only for 64-bit processes
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 282) on: enable for both 32- and 64-bit processes
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 283) off: disable for both 32- and 64-bit processes
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 284)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 285) alloc_snapshot [FTRACE]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 286) Allocate the ftrace snapshot buffer on boot up when the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 287) main buffer is allocated. This is handy if debugging
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 288) and you need to use tracing_snapshot() on boot up, and
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 289) do not want to use tracing_snapshot_alloc() as it needs
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 290) to be done where GFP_KERNEL allocations are allowed.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 291)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 292) allow_file_spec_access
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 293) Allow speculative faults on file backed pages.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 294) Speculative faults are enabled only for those vm_ops
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 295) that implement and return true for allow_speculation
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 296) callback.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 297)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 298) allow_mismatched_32bit_el0 [ARM64]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 299) Allow execve() of 32-bit applications and setting of the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 300) PER_LINUX32 personality on systems where only a strict
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 301) subset of the CPUs support 32-bit EL0. When this
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 302) parameter is present, the set of CPUs supporting 32-bit
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 303) EL0 is indicated by /sys/devices/system/cpu/aarch32_el0
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 304) and hot-unplug operations may be restricted.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 305)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 306) amd_iommu= [HW,X86-64]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 307) Pass parameters to the AMD IOMMU driver in the system.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 308) Possible values are:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 309) fullflush - enable flushing of IO/TLB entries when
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 310) they are unmapped. Otherwise they are
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 311) flushed before they will be reused, which
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 312) is a lot of faster
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 313) off - do not initialize any AMD IOMMU found in
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 314) the system
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 315) force_isolation - Force device isolation for all
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 316) devices. The IOMMU driver is not
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 317) allowed anymore to lift isolation
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 318) requirements as needed. This option
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 319) does not override iommu=pt
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 320)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 321) amd_iommu_dump= [HW,X86-64]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 322) Enable AMD IOMMU driver option to dump the ACPI table
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 323) for AMD IOMMU. With this option enabled, AMD IOMMU
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 324) driver will print ACPI tables for AMD IOMMU during
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 325) IOMMU initialization.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 326)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 327) amd_iommu_intr= [HW,X86-64]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 328) Specifies one of the following AMD IOMMU interrupt
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 329) remapping modes:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 330) legacy - Use legacy interrupt remapping mode.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 331) vapic - Use virtual APIC mode, which allows IOMMU
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 332) to inject interrupts directly into guest.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 333) This mode requires kvm-amd.avic=1.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 334) (Default when IOMMU HW support is present.)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 335)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 336) amijoy.map= [HW,JOY] Amiga joystick support
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 337) Map of devices attached to JOY0DAT and JOY1DAT
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 338) Format: <a>,<b>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 339) See also Documentation/input/joydev/joystick.rst
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 340)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 341) analog.map= [HW,JOY] Analog joystick and gamepad support
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 342) Specifies type or capabilities of an analog joystick
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 343) connected to one of 16 gameports
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 344) Format: <type1>,<type2>,..<type16>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 345)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 346) apc= [HW,SPARC]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 347) Power management functions (SPARCstation-4/5 + deriv.)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 348) Format: noidle
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 349) Disable APC CPU standby support. SPARCstation-Fox does
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 350) not play well with APC CPU idle - disable it if you have
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 351) APC and your system crashes randomly.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 352)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 353) apic= [APIC,X86] Advanced Programmable Interrupt Controller
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 354) Change the output verbosity while booting
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 355) Format: { quiet (default) | verbose | debug }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 356) Change the amount of debugging information output
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 357) when initialising the APIC and IO-APIC components.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 358) For X86-32, this can also be used to specify an APIC
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 359) driver name.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 360) Format: apic=driver_name
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 361) Examples: apic=bigsmp
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 362)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 363) apic_extnmi= [APIC,X86] External NMI delivery setting
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 364) Format: { bsp (default) | all | none }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 365) bsp: External NMI is delivered only to CPU 0
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 366) all: External NMIs are broadcast to all CPUs as a
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 367) backup of CPU 0
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 368) none: External NMI is masked for all CPUs. This is
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 369) useful so that a dump capture kernel won't be
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 370) shot down by NMI
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 371)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 372) autoconf= [IPV6]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 373) See Documentation/networking/ipv6.rst.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 374)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 375) show_lapic= [APIC,X86] Advanced Programmable Interrupt Controller
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 376) Limit apic dumping. The parameter defines the maximal
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 377) number of local apics being dumped. Also it is possible
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 378) to set it to "all" by meaning -- no limit here.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 379) Format: { 1 (default) | 2 | ... | all }.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 380) The parameter valid if only apic=debug or
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 381) apic=verbose is specified.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 382) Example: apic=debug show_lapic=all
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 383)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 384) apm= [APM] Advanced Power Management
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 385) See header of arch/x86/kernel/apm_32.c.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 386)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 387) arcrimi= [HW,NET] ARCnet - "RIM I" (entirely mem-mapped) cards
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 388) Format: <io>,<irq>,<nodeID>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 389)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 390) arm64.nobti [ARM64] Unconditionally disable Branch Target
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 391) Identification support
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 392)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 393) arm64.nopauth [ARM64] Unconditionally disable Pointer Authentication
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 394) support
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 395)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 396) arm64.nomte [ARM64] Unconditionally disable Memory Tagging Extension
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 397) support
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 398)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 399) ataflop= [HW,M68k]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 400)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 401) atarimouse= [HW,MOUSE] Atari Mouse
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 402)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 403) atkbd.extra= [HW] Enable extra LEDs and keys on IBM RapidAccess,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 404) EzKey and similar keyboards
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 405)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 406) atkbd.reset= [HW] Reset keyboard during initialization
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 407)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 408) atkbd.set= [HW] Select keyboard code set
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 409) Format: <int> (2 = AT (default), 3 = PS/2)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 410)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 411) atkbd.scroll= [HW] Enable scroll wheel on MS Office and similar
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 412) keyboards
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 413)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 414) atkbd.softraw= [HW] Choose between synthetic and real raw mode
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 415) Format: <bool> (0 = real, 1 = synthetic (default))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 416)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 417) atkbd.softrepeat= [HW]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 418) Use software keyboard repeat
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 419)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 420) audit= [KNL] Enable the audit sub-system
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 421) Format: { "0" | "1" | "off" | "on" }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 422) 0 | off - kernel audit is disabled and can not be
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 423) enabled until the next reboot
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 424) unset - kernel audit is initialized but disabled and
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 425) will be fully enabled by the userspace auditd.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 426) 1 | on - kernel audit is initialized and partially
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 427) enabled, storing at most audit_backlog_limit
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 428) messages in RAM until it is fully enabled by the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 429) userspace auditd.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 430) Default: unset
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 431)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 432) audit_backlog_limit= [KNL] Set the audit queue size limit.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 433) Format: <int> (must be >=0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 434) Default: 64
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 435)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 436) bau= [X86_UV] Enable the BAU on SGI UV. The default
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 437) behavior is to disable the BAU (i.e. bau=0).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 438) Format: { "0" | "1" }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 439) 0 - Disable the BAU.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 440) 1 - Enable the BAU.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 441) unset - Disable the BAU.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 442)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 443) baycom_epp= [HW,AX25]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 444) Format: <io>,<mode>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 445)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 446) baycom_par= [HW,AX25] BayCom Parallel Port AX.25 Modem
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 447) Format: <io>,<mode>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 448) See header of drivers/net/hamradio/baycom_par.c.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 449)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 450) baycom_ser_fdx= [HW,AX25]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 451) BayCom Serial Port AX.25 Modem (Full Duplex Mode)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 452) Format: <io>,<irq>,<mode>[,<baud>]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 453) See header of drivers/net/hamradio/baycom_ser_fdx.c.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 454)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 455) baycom_ser_hdx= [HW,AX25]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 456) BayCom Serial Port AX.25 Modem (Half Duplex Mode)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 457) Format: <io>,<irq>,<mode>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 458) See header of drivers/net/hamradio/baycom_ser_hdx.c.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 459)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 460) blkdevparts= Manual partition parsing of block device(s) for
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 461) embedded devices based on command line input.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 462) See Documentation/block/cmdline-partition.rst
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 463)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 464) boot_delay= Milliseconds to delay each printk during boot.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 465) Values larger than 10 seconds (10000) are changed to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 466) no delay (0).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 467) Format: integer
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 468)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 469) bootconfig [KNL]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 470) Extended command line options can be added to an initrd
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 471) and this will cause the kernel to look for it.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 472)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 473) See Documentation/admin-guide/bootconfig.rst
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 474)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 475) bert_disable [ACPI]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 476) Disable BERT OS support on buggy BIOSes.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 477)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 478) bgrt_disable [ACPI][X86]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 479) Disable BGRT to avoid flickering OEM logo.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 480)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 481) bttv.card= [HW,V4L] bttv (bt848 + bt878 based grabber cards)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 482) bttv.radio= Most important insmod options are available as
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 483) kernel args too.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 484) bttv.pll= See Documentation/admin-guide/media/bttv.rst
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 485) bttv.tuner=
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 486)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 487) bulk_remove=off [PPC] This parameter disables the use of the pSeries
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 488) firmware feature for flushing multiple hpte entries
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 489) at a time.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 490)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 491) c101= [NET] Moxa C101 synchronous serial card
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 492)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 493) cachesize= [BUGS=X86-32] Override level 2 CPU cache size detection.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 494) Sometimes CPU hardware bugs make them report the cache
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 495) size incorrectly. The kernel will attempt work arounds
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 496) to fix known problems, but for some CPUs it is not
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 497) possible to determine what the correct size should be.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 498) This option provides an override for these situations.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 499)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 500) carrier_timeout=
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 501) [NET] Specifies amount of time (in seconds) that
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 502) the kernel should wait for a network carrier. By default
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 503) it waits 120 seconds.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 504)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 505) ca_keys= [KEYS] This parameter identifies a specific key(s) on
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 506) the system trusted keyring to be used for certificate
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 507) trust validation.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 508) format: { id:<keyid> | builtin }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 509)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 510) cca= [MIPS] Override the kernel pages' cache coherency
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 511) algorithm. Accepted values range from 0 to 7
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 512) inclusive. See arch/mips/include/asm/pgtable-bits.h
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 513) for platform specific values (SB1, Loongson3 and
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 514) others).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 515)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 516) ccw_timeout_log [S390]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 517) See Documentation/s390/common_io.rst for details.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 518)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 519) cgroup_disable= [KNL] Disable a particular controller or optional feature
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 520) Format: {name of the controller(s) or feature(s) to disable}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 521) The effects of cgroup_disable=foo are:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 522) - foo isn't auto-mounted if you mount all cgroups in
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 523) a single hierarchy
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 524) - foo isn't visible as an individually mountable
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 525) subsystem
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 526) - if foo is an optional feature then the feature is
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 527) disabled and corresponding cgroup files are not
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 528) created
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 529) {Currently only "memory" controller deal with this and
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 530) cut the overhead, others just disable the usage. So
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 531) only cgroup_disable=memory is actually worthy}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 532) Specifying "pressure" disables per-cgroup pressure
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 533) stall information accounting feature
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 534)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 535) cgroup_no_v1= [KNL] Disable cgroup controllers and named hierarchies in v1
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 536) Format: { { controller | "all" | "named" }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 537) [,{ controller | "all" | "named" }...] }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 538) Like cgroup_disable, but only applies to cgroup v1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 539) the blacklisted controllers remain available in cgroup2.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 540) "all" blacklists all controllers and "named" disables
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 541) named mounts. Specifying both "all" and "named" disables
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 542) all v1 hierarchies.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 543)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 544) cgroup.memory= [KNL] Pass options to the cgroup memory controller.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 545) Format: <string>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 546) nosocket -- Disable socket memory accounting.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 547) nokmem -- Disable kernel memory accounting.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 548)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 549) checkreqprot [SELINUX] Set initial checkreqprot flag value.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 550) Format: { "0" | "1" }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 551) See security/selinux/Kconfig help text.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 552) 0 -- check protection applied by kernel (includes
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 553) any implied execute protection).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 554) 1 -- check protection requested by application.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 555) Default value is set via a kernel config option.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 556) Value can be changed at runtime via
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 557) /sys/fs/selinux/checkreqprot.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 558) Setting checkreqprot to 1 is deprecated.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 559)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 560) cio_ignore= [S390]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 561) See Documentation/s390/common_io.rst for details.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 562) clk_ignore_unused
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 563) [CLK]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 564) Prevents the clock framework from automatically gating
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 565) clocks that have not been explicitly enabled by a Linux
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 566) device driver but are enabled in hardware at reset or
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 567) by the bootloader/firmware. Note that this does not
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 568) force such clocks to be always-on nor does it reserve
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 569) those clocks in any way. This parameter is useful for
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 570) debug and development, but should not be needed on a
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 571) platform with proper driver support. For more
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 572) information, see Documentation/driver-api/clk.rst.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 573)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 574) clock= [BUGS=X86-32, HW] gettimeofday clocksource override.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 575) [Deprecated]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 576) Forces specified clocksource (if available) to be used
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 577) when calculating gettimeofday(). If specified
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 578) clocksource is not available, it defaults to PIT.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 579) Format: { pit | tsc | cyclone | pmtmr }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 580)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 581) clocksource= Override the default clocksource
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 582) Format: <string>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 583) Override the default clocksource and use the clocksource
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 584) with the name specified.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 585) Some clocksource names to choose from, depending on
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 586) the platform:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 587) [all] jiffies (this is the base, fallback clocksource)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 588) [ACPI] acpi_pm
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 589) [ARM] imx_timer1,OSTS,netx_timer,mpu_timer2,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 590) pxa_timer,timer3,32k_counter,timer0_1
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 591) [X86-32] pit,hpet,tsc;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 592) scx200_hrt on Geode; cyclone on IBM x440
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 593) [MIPS] MIPS
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 594) [PARISC] cr16
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 595) [S390] tod
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 596) [SH] SuperH
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 597) [SPARC64] tick
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 598) [X86-64] hpet,tsc
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 599)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 600) clocksource.arm_arch_timer.evtstrm=
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 601) [ARM,ARM64]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 602) Format: <bool>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 603) Enable/disable the eventstream feature of the ARM
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 604) architected timer so that code using WFE-based polling
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 605) loops can be debugged more effectively on production
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 606) systems.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 607)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 608) clocksource.max_cswd_read_retries= [KNL]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 609) Number of clocksource_watchdog() retries due to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 610) external delays before the clock will be marked
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 611) unstable. Defaults to three retries, that is,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 612) four attempts to read the clock under test.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 613)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 614) clearcpuid=BITNUM[,BITNUM...] [X86]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 615) Disable CPUID feature X for the kernel. See
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 616) arch/x86/include/asm/cpufeatures.h for the valid bit
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 617) numbers. Note the Linux specific bits are not necessarily
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 618) stable over kernel options, but the vendor specific
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 619) ones should be.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 620) Also note that user programs calling CPUID directly
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 621) or using the feature without checking anything
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 622) will still see it. This just prevents it from
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 623) being used by the kernel or shown in /proc/cpuinfo.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 624) Also note the kernel might malfunction if you disable
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 625) some critical bits.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 626)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 627) cma=nn[MG]@[start[MG][-end[MG]]]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 628) [KNL,CMA]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 629) Sets the size of kernel global memory area for
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 630) contiguous memory allocations and optionally the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 631) placement constraint by the physical address range of
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 632) memory allocations. A value of 0 disables CMA
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 633) altogether. For more information, see
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 634) kernel/dma/contiguous.c
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 635)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 636) cma_pernuma=nn[MG]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 637) [ARM64,KNL]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 638) Sets the size of kernel per-numa memory area for
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 639) contiguous memory allocations. A value of 0 disables
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 640) per-numa CMA altogether. And If this option is not
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 641) specificed, the default value is 0.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 642) With per-numa CMA enabled, DMA users on node nid will
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 643) first try to allocate buffer from the pernuma area
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 644) which is located in node nid, if the allocation fails,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 645) they will fallback to the global default memory area.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 646)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 647) cmo_free_hint= [PPC] Format: { yes | no }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 648) Specify whether pages are marked as being inactive
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 649) when they are freed. This is used in CMO environments
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 650) to determine OS memory pressure for page stealing by
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 651) a hypervisor.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 652) Default: yes
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 653)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 654) coherent_pool=nn[KMG] [ARM,KNL]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 655) Sets the size of memory pool for coherent, atomic dma
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 656) allocations, by default set to 256K.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 657)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 658) com20020= [HW,NET] ARCnet - COM20020 chipset
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 659) Format:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 660) <io>[,<irq>[,<nodeID>[,<backplane>[,<ckp>[,<timeout>]]]]]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 661)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 662) com90io= [HW,NET] ARCnet - COM90xx chipset (IO-mapped buffers)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 663) Format: <io>[,<irq>]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 664)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 665) com90xx= [HW,NET]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 666) ARCnet - COM90xx chipset (memory-mapped buffers)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 667) Format: <io>[,<irq>[,<memstart>]]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 668)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 669) condev= [HW,S390] console device
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 670) conmode=
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 671)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 672) console= [KNL] Output console device and options.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 673)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 674) tty<n> Use the virtual console device <n>.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 675)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 676) ttyS<n>[,options]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 677) ttyUSB0[,options]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 678) Use the specified serial port. The options are of
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 679) the form "bbbbpnf", where "bbbb" is the baud rate,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 680) "p" is parity ("n", "o", or "e"), "n" is number of
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 681) bits, and "f" is flow control ("r" for RTS or
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 682) omit it). Default is "9600n8".
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 683)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 684) See Documentation/admin-guide/serial-console.rst for more
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 685) information. See
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 686) Documentation/networking/netconsole.rst for an
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 687) alternative.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 688)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 689) uart[8250],io,<addr>[,options]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 690) uart[8250],mmio,<addr>[,options]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 691) uart[8250],mmio16,<addr>[,options]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 692) uart[8250],mmio32,<addr>[,options]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 693) uart[8250],0x<addr>[,options]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 694) Start an early, polled-mode console on the 8250/16550
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 695) UART at the specified I/O port or MMIO address,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 696) switching to the matching ttyS device later.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 697) MMIO inter-register address stride is either 8-bit
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 698) (mmio), 16-bit (mmio16), or 32-bit (mmio32).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 699) If none of [io|mmio|mmio16|mmio32], <addr> is assumed
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 700) to be equivalent to 'mmio'. 'options' are specified in
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 701) the same format described for ttyS above; if unspecified,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 702) the h/w is not re-initialized.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 703)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 704) hvc<n> Use the hypervisor console device <n>. This is for
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 705) both Xen and PowerPC hypervisors.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 706)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 707) If the device connected to the port is not a TTY but a braille
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 708) device, prepend "brl," before the device type, for instance
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 709) console=brl,ttyS0
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 710) For now, only VisioBraille is supported.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 711)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 712) console_msg_format=
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 713) [KNL] Change console messages format
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 714) default
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 715) By default we print messages on consoles in
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 716) "[time stamp] text\n" format (time stamp may not be
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 717) printed, depending on CONFIG_PRINTK_TIME or
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 718) `printk_time' param).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 719) syslog
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 720) Switch to syslog format: "<%u>[time stamp] text\n"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 721) IOW, each message will have a facility and loglevel
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 722) prefix. The format is similar to one used by syslog()
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 723) syscall, or to executing "dmesg -S --raw" or to reading
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 724) from /proc/kmsg.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 725)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 726) consoleblank= [KNL] The console blank (screen saver) timeout in
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 727) seconds. A value of 0 disables the blank timer.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 728) Defaults to 0.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 729)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 730) coredump_filter=
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 731) [KNL] Change the default value for
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 732) /proc/<pid>/coredump_filter.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 733) See also Documentation/filesystems/proc.rst.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 734)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 735) coresight_cpu_debug.enable
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 736) [ARM,ARM64]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 737) Format: <bool>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 738) Enable/disable the CPU sampling based debugging.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 739) 0: default value, disable debugging
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 740) 1: enable debugging at boot time
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 741)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 742) cpuidle.off=1 [CPU_IDLE]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 743) disable the cpuidle sub-system
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 744)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 745) cpuidle.governor=
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 746) [CPU_IDLE] Name of the cpuidle governor to use.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 747)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 748) cpufreq.off=1 [CPU_FREQ]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 749) disable the cpufreq sub-system
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 750)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 751) cpufreq.default_governor=
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 752) [CPU_FREQ] Name of the default cpufreq governor or
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 753) policy to use. This governor must be registered in the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 754) kernel before the cpufreq driver probes.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 755)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 756) cpu_init_udelay=N
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 757) [X86] Delay for N microsec between assert and de-assert
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 758) of APIC INIT to start processors. This delay occurs
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 759) on every CPU online, such as boot, and resume from suspend.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 760) Default: 10000
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 761)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 762) cpcihp_generic= [HW,PCI] Generic port I/O CompactPCI driver
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 763) Format:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 764) <first_slot>,<last_slot>,<port>,<enum_bit>[,<debug>]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 765)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 766) crashkernel=size[KMG][@offset[KMG]]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 767) [KNL] Using kexec, Linux can switch to a 'crash kernel'
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 768) upon panic. This parameter reserves the physical
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 769) memory region [offset, offset + size] for that kernel
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 770) image. If '@offset' is omitted, then a suitable offset
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 771) is selected automatically.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 772) [KNL, X86-64] Select a region under 4G first, and
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 773) fall back to reserve region above 4G when '@offset'
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 774) hasn't been specified.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 775) See Documentation/admin-guide/kdump/kdump.rst for further details.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 776)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 777) crashkernel=range1:size1[,range2:size2,...][@offset]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 778) [KNL] Same as above, but depends on the memory
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 779) in the running system. The syntax of range is
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 780) start-[end] where start and end are both
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 781) a memory unit (amount[KMG]). See also
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 782) Documentation/admin-guide/kdump/kdump.rst for an example.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 783)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 784) crashkernel=size[KMG],high
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 785) [KNL, X86-64] range could be above 4G. Allow kernel
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 786) to allocate physical memory region from top, so could
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 787) be above 4G if system have more than 4G ram installed.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 788) Otherwise memory region will be allocated below 4G, if
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 789) available.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 790) It will be ignored if crashkernel=X is specified.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 791) crashkernel=size[KMG],low
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 792) [KNL, X86-64] range under 4G. When crashkernel=X,high
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 793) is passed, kernel could allocate physical memory region
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 794) above 4G, that cause second kernel crash on system
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 795) that require some amount of low memory, e.g. swiotlb
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 796) requires at least 64M+32K low memory, also enough extra
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 797) low memory is needed to make sure DMA buffers for 32-bit
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 798) devices won't run out. Kernel would try to allocate at
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 799) at least 256M below 4G automatically.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 800) This one let user to specify own low range under 4G
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 801) for second kernel instead.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 802) 0: to disable low allocation.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 803) It will be ignored when crashkernel=X,high is not used
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 804) or memory reserved is below 4G.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 805)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 806) cryptomgr.notests
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 807) [KNL] Disable crypto self-tests
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 808)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 809) cs89x0_dma= [HW,NET]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 810) Format: <dma>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 811)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 812) cs89x0_media= [HW,NET]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 813) Format: { rj45 | aui | bnc }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 814)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 815) dasd= [HW,NET]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 816) See header of drivers/s390/block/dasd_devmap.c.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 817)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 818) db9.dev[2|3]= [HW,JOY] Multisystem joystick support via parallel port
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 819) (one device per port)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 820) Format: <port#>,<type>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 821) See also Documentation/input/devices/joystick-parport.rst
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 822)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 823) ddebug_query= [KNL,DYNAMIC_DEBUG] Enable debug messages at early boot
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 824) time. See
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 825) Documentation/admin-guide/dynamic-debug-howto.rst for
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 826) details. Deprecated, see dyndbg.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 827)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 828) debug [KNL] Enable kernel debugging (events log level).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 829)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 830) debug_boot_weak_hash
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 831) [KNL] Enable printing [hashed] pointers early in the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 832) boot sequence. If enabled, we use a weak hash instead
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 833) of siphash to hash pointers. Use this option if you are
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 834) seeing instances of '(___ptrval___)') and need to see a
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 835) value (hashed pointer) instead. Cryptographically
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 836) insecure, please do not use on production kernels.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 837)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 838) debug_locks_verbose=
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 839) [KNL] verbose self-tests
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 840) Format=<0|1>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 841) Print debugging info while doing the locking API
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 842) self-tests.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 843) We default to 0 (no extra messages), setting it to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 844) 1 will print _a lot_ more information - normally
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 845) only useful to kernel developers.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 846)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 847) debug_objects [KNL] Enable object debugging
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 848)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 849) no_debug_objects
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 850) [KNL] Disable object debugging
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 851)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 852) debug_guardpage_minorder=
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 853) [KNL] When CONFIG_DEBUG_PAGEALLOC is set, this
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 854) parameter allows control of the order of pages that will
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 855) be intentionally kept free (and hence protected) by the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 856) buddy allocator. Bigger value increase the probability
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 857) of catching random memory corruption, but reduce the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 858) amount of memory for normal system use. The maximum
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 859) possible value is MAX_ORDER/2. Setting this parameter
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 860) to 1 or 2 should be enough to identify most random
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 861) memory corruption problems caused by bugs in kernel or
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 862) driver code when a CPU writes to (or reads from) a
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 863) random memory location. Note that there exists a class
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 864) of memory corruptions problems caused by buggy H/W or
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 865) F/W or by drivers badly programing DMA (basically when
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 866) memory is written at bus level and the CPU MMU is
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 867) bypassed) which are not detectable by
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 868) CONFIG_DEBUG_PAGEALLOC, hence this option will not help
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 869) tracking down these problems.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 870)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 871) debug_pagealloc=
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 872) [KNL] When CONFIG_DEBUG_PAGEALLOC is set, this parameter
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 873) enables the feature at boot time. By default, it is
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 874) disabled and the system will work mostly the same as a
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 875) kernel built without CONFIG_DEBUG_PAGEALLOC.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 876) Note: to get most of debug_pagealloc error reports, it's
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 877) useful to also enable the page_owner functionality.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 878) on: enable the feature
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 879)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 880) debugfs= [KNL] This parameter enables what is exposed to userspace
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 881) and debugfs internal clients.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 882) Format: { on, no-mount, off }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 883) on: All functions are enabled.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 884) no-mount:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 885) Filesystem is not registered but kernel clients can
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 886) access APIs and a crashkernel can be used to read
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 887) its content. There is nothing to mount.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 888) off: Filesystem is not registered and clients
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 889) get a -EPERM as result when trying to register files
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 890) or directories within debugfs.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 891) This is equivalent of the runtime functionality if
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 892) debugfs was not enabled in the kernel at all.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 893) Default value is set in build-time with a kernel configuration.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 894)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 895) debugpat [X86] Enable PAT debugging
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 896)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 897) decnet.addr= [HW,NET]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 898) Format: <area>[,<node>]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 899) See also Documentation/networking/decnet.rst.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 900)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 901) default_hugepagesz=
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 902) [HW] The size of the default HugeTLB page. This is
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 903) the size represented by the legacy /proc/ hugepages
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 904) APIs. In addition, this is the default hugetlb size
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 905) used for shmget(), mmap() and mounting hugetlbfs
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 906) filesystems. If not specified, defaults to the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 907) architecture's default huge page size. Huge page
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 908) sizes are architecture dependent. See also
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 909) Documentation/admin-guide/mm/hugetlbpage.rst.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 910) Format: size[KMG]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 911)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 912) deferred_probe_timeout=
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 913) [KNL] Debugging option to set a timeout in seconds for
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 914) deferred probe to give up waiting on dependencies to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 915) probe. Only specific dependencies (subsystems or
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 916) drivers) that have opted in will be ignored. A timeout of 0
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 917) will timeout at the end of initcalls. This option will also
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 918) dump out devices still on the deferred probe list after
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 919) retrying.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 920)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 921) dfltcc= [HW,S390]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 922) Format: { on | off | def_only | inf_only | always }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 923) on: s390 zlib hardware support for compression on
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 924) level 1 and decompression (default)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 925) off: No s390 zlib hardware support
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 926) def_only: s390 zlib hardware support for deflate
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 927) only (compression on level 1)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 928) inf_only: s390 zlib hardware support for inflate
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 929) only (decompression)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 930) always: Same as 'on' but ignores the selected compression
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 931) level always using hardware support (used for debugging)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 932)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 933) dhash_entries= [KNL]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 934) Set number of hash buckets for dentry cache.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 935)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 936) disable_1tb_segments [PPC]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 937) Disables the use of 1TB hash page table segments. This
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 938) causes the kernel to fall back to 256MB segments which
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 939) can be useful when debugging issues that require an SLB
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 940) miss to occur.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 941)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 942) disable_dma32= [KNL]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 943) Dynamically disable ZONE_DMA32 on kernels compiled with
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 944) CONFIG_ZONE_DMA32=y.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 945)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 946) stress_slb [PPC]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 947) Limits the number of kernel SLB entries, and flushes
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 948) them frequently to increase the rate of SLB faults
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 949) on kernel addresses.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 950)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 951) disable= [IPV6]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 952) See Documentation/networking/ipv6.rst.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 953)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 954) hardened_usercopy=
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 955) [KNL] Under CONFIG_HARDENED_USERCOPY, whether
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 956) hardening is enabled for this boot. Hardened
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 957) usercopy checking is used to protect the kernel
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 958) from reading or writing beyond known memory
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 959) allocation boundaries as a proactive defense
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 960) against bounds-checking flaws in the kernel's
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 961) copy_to_user()/copy_from_user() interface.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 962) on Perform hardened usercopy checks (default).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 963) off Disable hardened usercopy checks.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 964)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 965) disable_radix [PPC]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 966) Disable RADIX MMU mode on POWER9
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 967)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 968) radix_hcall_invalidate=on [PPC/PSERIES]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 969) Disable RADIX GTSE feature and use hcall for TLB
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 970) invalidate.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 971)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 972) disable_tlbie [PPC]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 973) Disable TLBIE instruction. Currently does not work
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 974) with KVM, with HASH MMU, or with coherent accelerators.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 975)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 976) disable_cpu_apicid= [X86,APIC,SMP]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 977) Format: <int>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 978) The number of initial APIC ID for the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 979) corresponding CPU to be disabled at boot,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 980) mostly used for the kdump 2nd kernel to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 981) disable BSP to wake up multiple CPUs without
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 982) causing system reset or hang due to sending
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 983) INIT from AP to BSP.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 984)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 985) perf_v4_pmi= [X86,INTEL]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 986) Format: <bool>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 987) Disable Intel PMU counter freezing feature.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 988) The feature only exists starting from
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 989) Arch Perfmon v4 (Skylake and newer).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 990)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 991) disable_ddw [PPC/PSERIES]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 992) Disable Dynamic DMA Window support. Use this
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 993) to workaround buggy firmware.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 994)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 995) disable_ipv6= [IPV6]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 996) See Documentation/networking/ipv6.rst.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 997)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 998) disable_mtrr_cleanup [X86]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 999) The kernel tries to adjust MTRR layout from continuous
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1000) to discrete, to make X server driver able to add WB
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1001) entry later. This parameter disables that.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1002)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1003) disable_mtrr_trim [X86, Intel and AMD only]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1004) By default the kernel will trim any uncacheable
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1005) memory out of your available memory pool based on
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1006) MTRR settings. This parameter disables that behavior,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1007) possibly causing your machine to run very slowly.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1008)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1009) disable_timer_pin_1 [X86]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1010) Disable PIN 1 of APIC timer
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1011) Can be useful to work around chipset bugs.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1012)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1013) dis_ucode_ldr [X86] Disable the microcode loader.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1014)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1015) dma_debug=off If the kernel is compiled with DMA_API_DEBUG support,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1016) this option disables the debugging code at boot.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1017)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1018) dma_debug_entries=<number>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1019) This option allows to tune the number of preallocated
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1020) entries for DMA-API debugging code. One entry is
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1021) required per DMA-API allocation. Use this if the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1022) DMA-API debugging code disables itself because the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1023) architectural default is too low.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1024)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1025) dma_debug_driver=<driver_name>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1026) With this option the DMA-API debugging driver
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1027) filter feature can be enabled at boot time. Just
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1028) pass the driver to filter for as the parameter.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1029) The filter can be disabled or changed to another
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1030) driver later using sysfs.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1031)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1032) driver_async_probe= [KNL]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1033) List of driver names to be probed asynchronously.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1034) Format: <driver_name1>,<driver_name2>...
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1035)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1036) drm.edid_firmware=[<connector>:]<file>[,[<connector>:]<file>]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1037) Broken monitors, graphic adapters, KVMs and EDIDless
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1038) panels may send no or incorrect EDID data sets.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1039) This parameter allows to specify an EDID data sets
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1040) in the /lib/firmware directory that are used instead.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1041) Generic built-in EDID data sets are used, if one of
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1042) edid/1024x768.bin, edid/1280x1024.bin,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1043) edid/1680x1050.bin, or edid/1920x1080.bin is given
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1044) and no file with the same name exists. Details and
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1045) instructions how to build your own EDID data are
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1046) available in Documentation/admin-guide/edid.rst. An EDID
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1047) data set will only be used for a particular connector,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1048) if its name and a colon are prepended to the EDID
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1049) name. Each connector may use a unique EDID data
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1050) set by separating the files with a comma. An EDID
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1051) data set with no connector name will be used for
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1052) any connectors not explicitly specified.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1053)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1054) dscc4.setup= [NET]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1055)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1056) dt_cpu_ftrs= [PPC]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1057) Format: {"off" | "known"}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1058) Control how the dt_cpu_ftrs device-tree binding is
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1059) used for CPU feature discovery and setup (if it
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1060) exists).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1061) off: Do not use it, fall back to legacy cpu table.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1062) known: Do not pass through unknown features to guests
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1063) or userspace, only those that the kernel is aware of.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1064)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1065) dump_apple_properties [X86]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1066) Dump name and content of EFI device properties on
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1067) x86 Macs. Useful for driver authors to determine
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1068) what data is available or for reverse-engineering.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1069)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1070) dyndbg[="val"] [KNL,DYNAMIC_DEBUG]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1071) <module>.dyndbg[="val"]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1072) Enable debug messages at boot time. See
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1073) Documentation/admin-guide/dynamic-debug-howto.rst
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1074) for details.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1075)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1076) nopku [X86] Disable Memory Protection Keys CPU feature found
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1077) in some Intel CPUs.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1078)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1079) <module>.async_probe [KNL]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1080) Enable asynchronous probe on this module.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1081)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1082) early_ioremap_debug [KNL]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1083) Enable debug messages in early_ioremap support. This
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1084) is useful for tracking down temporary early mappings
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1085) which are not unmapped.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1086)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1087) earlycon= [KNL] Output early console device and options.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1088)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1089) When used with no options, the early console is
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1090) determined by stdout-path property in device tree's
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1091) chosen node or the ACPI SPCR table if supported by
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1092) the platform.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1093)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1094) cdns,<addr>[,options]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1095) Start an early, polled-mode console on a Cadence
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1096) (xuartps) serial port at the specified address. Only
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1097) supported option is baud rate. If baud rate is not
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1098) specified, the serial port must already be setup and
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1099) configured.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1100)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1101) uart[8250],io,<addr>[,options]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1102) uart[8250],mmio,<addr>[,options]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1103) uart[8250],mmio32,<addr>[,options]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1104) uart[8250],mmio32be,<addr>[,options]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1105) uart[8250],0x<addr>[,options]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1106) Start an early, polled-mode console on the 8250/16550
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1107) UART at the specified I/O port or MMIO address.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1108) MMIO inter-register address stride is either 8-bit
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1109) (mmio) or 32-bit (mmio32 or mmio32be).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1110) If none of [io|mmio|mmio32|mmio32be], <addr> is assumed
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1111) to be equivalent to 'mmio'. 'options' are specified
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1112) in the same format described for "console=ttyS<n>"; if
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1113) unspecified, the h/w is not initialized.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1114)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1115) pl011,<addr>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1116) pl011,mmio32,<addr>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1117) Start an early, polled-mode console on a pl011 serial
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1118) port at the specified address. The pl011 serial port
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1119) must already be setup and configured. Options are not
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1120) yet supported. If 'mmio32' is specified, then only
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1121) the driver will use only 32-bit accessors to read/write
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1122) the device registers.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1123)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1124) meson,<addr>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1125) Start an early, polled-mode console on a meson serial
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1126) port at the specified address. The serial port must
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1127) already be setup and configured. Options are not yet
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1128) supported.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1129)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1130) msm_serial,<addr>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1131) Start an early, polled-mode console on an msm serial
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1132) port at the specified address. The serial port
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1133) must already be setup and configured. Options are not
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1134) yet supported.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1135)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1136) msm_serial_dm,<addr>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1137) Start an early, polled-mode console on an msm serial
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1138) dm port at the specified address. The serial port
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1139) must already be setup and configured. Options are not
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1140) yet supported.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1141)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1142) owl,<addr>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1143) Start an early, polled-mode console on a serial port
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1144) of an Actions Semi SoC, such as S500 or S900, at the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1145) specified address. The serial port must already be
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1146) setup and configured. Options are not yet supported.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1147)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1148) rda,<addr>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1149) Start an early, polled-mode console on a serial port
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1150) of an RDA Micro SoC, such as RDA8810PL, at the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1151) specified address. The serial port must already be
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1152) setup and configured. Options are not yet supported.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1153)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1154) sbi
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1155) Use RISC-V SBI (Supervisor Binary Interface) for early
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1156) console.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1157)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1158) smh Use ARM semihosting calls for early console.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1159)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1160) s3c2410,<addr>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1161) s3c2412,<addr>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1162) s3c2440,<addr>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1163) s3c6400,<addr>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1164) s5pv210,<addr>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1165) exynos4210,<addr>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1166) Use early console provided by serial driver available
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1167) on Samsung SoCs, requires selecting proper type and
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1168) a correct base address of the selected UART port. The
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1169) serial port must already be setup and configured.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1170) Options are not yet supported.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1171)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1172) lantiq,<addr>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1173) Start an early, polled-mode console on a lantiq serial
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1174) (lqasc) port at the specified address. The serial port
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1175) must already be setup and configured. Options are not
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1176) yet supported.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1177)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1178) lpuart,<addr>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1179) lpuart32,<addr>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1180) Use early console provided by Freescale LP UART driver
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1181) found on Freescale Vybrid and QorIQ LS1021A processors.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1182) A valid base address must be provided, and the serial
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1183) port must already be setup and configured.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1184)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1185) ec_imx21,<addr>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1186) ec_imx6q,<addr>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1187) Start an early, polled-mode, output-only console on the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1188) Freescale i.MX UART at the specified address. The UART
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1189) must already be setup and configured.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1190)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1191) ar3700_uart,<addr>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1192) Start an early, polled-mode console on the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1193) Armada 3700 serial port at the specified
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1194) address. The serial port must already be setup
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1195) and configured. Options are not yet supported.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1196)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1197) qcom_geni,<addr>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1198) Start an early, polled-mode console on a Qualcomm
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1199) Generic Interface (GENI) based serial port at the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1200) specified address. The serial port must already be
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1201) setup and configured. Options are not yet supported.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1202)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1203) efifb,[options]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1204) Start an early, unaccelerated console on the EFI
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1205) memory mapped framebuffer (if available). On cache
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1206) coherent non-x86 systems that use system memory for
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1207) the framebuffer, pass the 'ram' option so that it is
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1208) mapped with the correct attributes.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1209)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1210) linflex,<addr>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1211) Use early console provided by Freescale LINFlexD UART
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1212) serial driver for NXP S32V234 SoCs. A valid base
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1213) address must be provided, and the serial port must
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1214) already be setup and configured.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1215)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1216) earlyprintk= [X86,SH,ARM,M68k,S390]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1217) earlyprintk=vga
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1218) earlyprintk=sclp
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1219) earlyprintk=xen
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1220) earlyprintk=serial[,ttySn[,baudrate]]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1221) earlyprintk=serial[,0x...[,baudrate]]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1222) earlyprintk=ttySn[,baudrate]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1223) earlyprintk=dbgp[debugController#]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1224) earlyprintk=pciserial[,force],bus:device.function[,baudrate]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1225) earlyprintk=xdbc[xhciController#]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1226)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1227) earlyprintk is useful when the kernel crashes before
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1228) the normal console is initialized. It is not enabled by
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1229) default because it has some cosmetic problems.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1230)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1231) Append ",keep" to not disable it when the real console
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1232) takes over.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1233)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1234) Only one of vga, efi, serial, or usb debug port can
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1235) be used at a time.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1236)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1237) Currently only ttyS0 and ttyS1 may be specified by
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1238) name. Other I/O ports may be explicitly specified
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1239) on some architectures (x86 and arm at least) by
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1240) replacing ttySn with an I/O port address, like this:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1241) earlyprintk=serial,0x1008,115200
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1242) You can find the port for a given device in
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1243) /proc/tty/driver/serial:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1244) 2: uart:ST16650V2 port:00001008 irq:18 ...
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1245)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1246) Interaction with the standard serial driver is not
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1247) very good.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1248)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1249) The VGA and EFI output is eventually overwritten by
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1250) the real console.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1251)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1252) The xen output can only be used by Xen PV guests.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1253)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1254) The sclp output can only be used on s390.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1255)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1256) The optional "force" to "pciserial" enables use of a
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1257) PCI device even when its classcode is not of the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1258) UART class.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1259)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1260) edac_report= [HW,EDAC] Control how to report EDAC event
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1261) Format: {"on" | "off" | "force"}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1262) on: enable EDAC to report H/W event. May be overridden
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1263) by other higher priority error reporting module.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1264) off: disable H/W event reporting through EDAC.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1265) force: enforce the use of EDAC to report H/W event.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1266) default: on.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1267)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1268) ekgdboc= [X86,KGDB] Allow early kernel console debugging
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1269) ekgdboc=kbd
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1270)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1271) This is designed to be used in conjunction with
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1272) the boot argument: earlyprintk=vga
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1273)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1274) This parameter works in place of the kgdboc parameter
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1275) but can only be used if the backing tty is available
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1276) very early in the boot process. For early debugging
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1277) via a serial port see kgdboc_earlycon instead.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1278)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1279) edd= [EDD]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1280) Format: {"off" | "on" | "skip[mbr]"}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1281)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1282) efi= [EFI]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1283) Format: { "debug", "disable_early_pci_dma",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1284) "nochunk", "noruntime", "nosoftreserve",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1285) "novamap", "no_disable_early_pci_dma" }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1286) debug: enable misc debug output.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1287) disable_early_pci_dma: disable the busmaster bit on all
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1288) PCI bridges while in the EFI boot stub.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1289) nochunk: disable reading files in "chunks" in the EFI
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1290) boot stub, as chunking can cause problems with some
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1291) firmware implementations.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1292) noruntime : disable EFI runtime services support
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1293) nosoftreserve: The EFI_MEMORY_SP (Specific Purpose)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1294) attribute may cause the kernel to reserve the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1295) memory range for a memory mapping driver to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1296) claim. Specify efi=nosoftreserve to disable this
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1297) reservation and treat the memory by its base type
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1298) (i.e. EFI_CONVENTIONAL_MEMORY / "System RAM").
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1299) novamap: do not call SetVirtualAddressMap().
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1300) no_disable_early_pci_dma: Leave the busmaster bit set
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1301) on all PCI bridges while in the EFI boot stub
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1302)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1303) efi_no_storage_paranoia [EFI; X86]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1304) Using this parameter you can use more than 50% of
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1305) your efi variable storage. Use this parameter only if
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1306) you are really sure that your UEFI does sane gc and
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1307) fulfills the spec otherwise your board may brick.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1308)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1309) efi_fake_mem= nn[KMG]@ss[KMG]:aa[,nn[KMG]@ss[KMG]:aa,..] [EFI; X86]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1310) Add arbitrary attribute to specific memory range by
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1311) updating original EFI memory map.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1312) Region of memory which aa attribute is added to is
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1313) from ss to ss+nn.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1314)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1315) If efi_fake_mem=2G@4G:0x10000,2G@0x10a0000000:0x10000
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1316) is specified, EFI_MEMORY_MORE_RELIABLE(0x10000)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1317) attribute is added to range 0x100000000-0x180000000 and
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1318) 0x10a0000000-0x1120000000.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1319)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1320) If efi_fake_mem=8G@9G:0x40000 is specified, the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1321) EFI_MEMORY_SP(0x40000) attribute is added to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1322) range 0x240000000-0x43fffffff.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1323)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1324) Using this parameter you can do debugging of EFI memmap
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1325) related features. For example, you can do debugging of
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1326) Address Range Mirroring feature even if your box
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1327) doesn't support it, or mark specific memory as
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1328) "soft reserved".
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1329)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1330) efivar_ssdt= [EFI; X86] Name of an EFI variable that contains an SSDT
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1331) that is to be dynamically loaded by Linux. If there are
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1332) multiple variables with the same name but with different
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1333) vendor GUIDs, all of them will be loaded. See
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1334) Documentation/admin-guide/acpi/ssdt-overlays.rst for details.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1335)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1336)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1337) eisa_irq_edge= [PARISC,HW]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1338) See header of drivers/parisc/eisa.c.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1339)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1340) elanfreq= [X86-32]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1341) See comment before function elanfreq_setup() in
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1342) arch/x86/kernel/cpu/cpufreq/elanfreq.c.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1343)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1344) elfcorehdr=[size[KMG]@]offset[KMG] [IA64,PPC,SH,X86,S390]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1345) Specifies physical address of start of kernel core
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1346) image elf header and optionally the size. Generally
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1347) kexec loader will pass this option to capture kernel.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1348) See Documentation/admin-guide/kdump/kdump.rst for details.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1349)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1350) enable_mtrr_cleanup [X86]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1351) The kernel tries to adjust MTRR layout from continuous
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1352) to discrete, to make X server driver able to add WB
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1353) entry later. This parameter enables that.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1354)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1355) enable_timer_pin_1 [X86]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1356) Enable PIN 1 of APIC timer
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1357) Can be useful to work around chipset bugs
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1358) (in particular on some ATI chipsets).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1359) The kernel tries to set a reasonable default.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1360)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1361) enforcing [SELINUX] Set initial enforcing status.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1362) Format: {"0" | "1"}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1363) See security/selinux/Kconfig help text.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1364) 0 -- permissive (log only, no denials).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1365) 1 -- enforcing (deny and log).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1366) Default value is 0.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1367) Value can be changed at runtime via
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1368) /sys/fs/selinux/enforce.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1369)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1370) erst_disable [ACPI]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1371) Disable Error Record Serialization Table (ERST)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1372) support.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1373)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1374) ether= [HW,NET] Ethernet cards parameters
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1375) This option is obsoleted by the "netdev=" option, which
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1376) has equivalent usage. See its documentation for details.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1377)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1378) evm= [EVM]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1379) Format: { "fix" }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1380) Permit 'security.evm' to be updated regardless of
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1381) current integrity status.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1382)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1383) failslab=
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1384) fail_usercopy=
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1385) fail_page_alloc=
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1386) fail_make_request=[KNL]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1387) General fault injection mechanism.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1388) Format: <interval>,<probability>,<space>,<times>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1389) See also Documentation/fault-injection/.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1390)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1391) fb_tunnels= [NET]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1392) Format: { initns | none }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1393) See Documentation/admin-guide/sysctl/net.rst for
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1394) fb_tunnels_only_for_init_ns
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1395)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1396) floppy= [HW]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1397) See Documentation/admin-guide/blockdev/floppy.rst.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1398)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1399) force_pal_cache_flush
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1400) [IA-64] Avoid check_sal_cache_flush which may hang on
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1401) buggy SAL_CACHE_FLUSH implementations. Using this
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1402) parameter will force ia64_sal_cache_flush to call
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1403) ia64_pal_cache_flush instead of SAL_CACHE_FLUSH.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1404)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1405) forcepae [X86-32]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1406) Forcefully enable Physical Address Extension (PAE).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1407) Many Pentium M systems disable PAE but may have a
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1408) functionally usable PAE implementation.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1409) Warning: use of this parameter will taint the kernel
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1410) and may cause unknown problems.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1411)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1412) ftrace=[tracer]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1413) [FTRACE] will set and start the specified tracer
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1414) as early as possible in order to facilitate early
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1415) boot debugging.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1416)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1417) ftrace_dump_on_oops[=orig_cpu]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1418) [FTRACE] will dump the trace buffers on oops.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1419) If no parameter is passed, ftrace will dump
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1420) buffers of all CPUs, but if you pass orig_cpu, it will
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1421) dump only the buffer of the CPU that triggered the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1422) oops.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1423)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1424) ftrace_filter=[function-list]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1425) [FTRACE] Limit the functions traced by the function
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1426) tracer at boot up. function-list is a comma separated
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1427) list of functions. This list can be changed at run
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1428) time by the set_ftrace_filter file in the debugfs
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1429) tracing directory.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1430)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1431) ftrace_notrace=[function-list]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1432) [FTRACE] Do not trace the functions specified in
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1433) function-list. This list can be changed at run time
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1434) by the set_ftrace_notrace file in the debugfs
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1435) tracing directory.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1436)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1437) ftrace_graph_filter=[function-list]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1438) [FTRACE] Limit the top level callers functions traced
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1439) by the function graph tracer at boot up.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1440) function-list is a comma separated list of functions
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1441) that can be changed at run time by the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1442) set_graph_function file in the debugfs tracing directory.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1443)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1444) ftrace_graph_notrace=[function-list]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1445) [FTRACE] Do not trace from the functions specified in
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1446) function-list. This list is a comma separated list of
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1447) functions that can be changed at run time by the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1448) set_graph_notrace file in the debugfs tracing directory.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1449)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1450) ftrace_graph_max_depth=<uint>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1451) [FTRACE] Used with the function graph tracer. This is
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1452) the max depth it will trace into a function. This value
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1453) can be changed at run time by the max_graph_depth file
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1454) in the tracefs tracing directory. default: 0 (no limit)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1455)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1456) fw_devlink= [KNL] Create device links between consumer and supplier
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1457) devices by scanning the firmware to infer the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1458) consumer/supplier relationships. This feature is
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1459) especially useful when drivers are loaded as modules as
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1460) it ensures proper ordering of tasks like device probing
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1461) (suppliers first, then consumers), supplier boot state
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1462) clean up (only after all consumers have probed),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1463) suspend/resume & runtime PM (consumers first, then
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1464) suppliers).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1465) Format: { off | permissive | on | rpm }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1466) off -- Don't create device links from firmware info.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1467) permissive -- Create device links from firmware info
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1468) but use it only for ordering boot state clean
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1469) up (sync_state() calls).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1470) on -- Create device links from firmware info and use it
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1471) to enforce probe and suspend/resume ordering.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1472) rpm -- Like "on", but also use to order runtime PM.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1473)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1474) fw_devlink.strict=<bool>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1475) [KNL] Treat all inferred dependencies as mandatory
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1476) dependencies. This only applies for fw_devlink=on|rpm.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1477) Format: <bool>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1478)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1479) gamecon.map[2|3]=
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1480) [HW,JOY] Multisystem joystick and NES/SNES/PSX pad
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1481) support via parallel port (up to 5 devices per port)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1482) Format: <port#>,<pad1>,<pad2>,<pad3>,<pad4>,<pad5>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1483) See also Documentation/input/devices/joystick-parport.rst
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1484)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1485) gamma= [HW,DRM]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1486)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1487) gart_fix_e820= [X86-64] disable the fix e820 for K8 GART
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1488) Format: off | on
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1489) default: on
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1490)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1491) gcov_persist= [GCOV] When non-zero (default), profiling data for
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1492) kernel modules is saved and remains accessible via
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1493) debugfs, even when the module is unloaded/reloaded.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1494) When zero, profiling data is discarded and associated
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1495) debugfs files are removed at module unload time.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1496)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1497) goldfish [X86] Enable the goldfish android emulator platform.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1498) Don't use this when you are not running on the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1499) android emulator
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1500)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1501) gpt [EFI] Forces disk with valid GPT signature but
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1502) invalid Protective MBR to be treated as GPT. If the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1503) primary GPT is corrupted, it enables the backup/alternate
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1504) GPT to be used instead.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1505)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1506) grcan.enable0= [HW] Configuration of physical interface 0. Determines
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1507) the "Enable 0" bit of the configuration register.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1508) Format: 0 | 1
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1509) Default: 0
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1510) grcan.enable1= [HW] Configuration of physical interface 1. Determines
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1511) the "Enable 0" bit of the configuration register.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1512) Format: 0 | 1
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1513) Default: 0
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1514) grcan.select= [HW] Select which physical interface to use.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1515) Format: 0 | 1
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1516) Default: 0
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1517) grcan.txsize= [HW] Sets the size of the tx buffer.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1518) Format: <unsigned int> such that (txsize & ~0x1fffc0) == 0.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1519) Default: 1024
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1520) grcan.rxsize= [HW] Sets the size of the rx buffer.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1521) Format: <unsigned int> such that (rxsize & ~0x1fffc0) == 0.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1522) Default: 1024
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1523)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1524) gpio-mockup.gpio_mockup_ranges
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1525) [HW] Sets the ranges of gpiochip of for this device.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1526) Format: <start1>,<end1>,<start2>,<end2>...
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1527)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1528) hardlockup_all_cpu_backtrace=
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1529) [KNL] Should the hard-lockup detector generate
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1530) backtraces on all cpus.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1531) Format: 0 | 1
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1532)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1533) hashdist= [KNL,NUMA] Large hashes allocated during boot
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1534) are distributed across NUMA nodes. Defaults on
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1535) for 64-bit NUMA, off otherwise.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1536) Format: 0 | 1 (for off | on)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1537)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1538) hcl= [IA-64] SGI's Hardware Graph compatibility layer
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1539)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1540) hd= [EIDE] (E)IDE hard drive subsystem geometry
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1541) Format: <cyl>,<head>,<sect>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1542)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1543) hest_disable [ACPI]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1544) Disable Hardware Error Source Table (HEST) support;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1545) corresponding firmware-first mode error processing
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1546) logic will be disabled.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1547)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1548) highmem=nn[KMG] [KNL,BOOT] forces the highmem zone to have an exact
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1549) size of <nn>. This works even on boxes that have no
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1550) highmem otherwise. This also works to reduce highmem
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1551) size on bigger boxes.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1552)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1553) highres= [KNL] Enable/disable high resolution timer mode.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1554) Valid parameters: "on", "off"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1555) Default: "on"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1556)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1557) hlt [BUGS=ARM,SH]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1558)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1559) hpet= [X86-32,HPET] option to control HPET usage
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1560) Format: { enable (default) | disable | force |
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1561) verbose }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1562) disable: disable HPET and use PIT instead
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1563) force: allow force enabled of undocumented chips (ICH4,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1564) VIA, nVidia)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1565) verbose: show contents of HPET registers during setup
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1566)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1567) hpet_mmap= [X86, HPET_MMAP] Allow userspace to mmap HPET
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1568) registers. Default set by CONFIG_HPET_MMAP_DEFAULT.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1569)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1570) hugetlb_cma= [HW] The size of a cma area used for allocation
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1571) of gigantic hugepages.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1572) Format: nn[KMGTPE]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1573)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1574) Reserve a cma area of given size and allocate gigantic
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1575) hugepages using the cma allocator. If enabled, the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1576) boot-time allocation of gigantic hugepages is skipped.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1577)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1578) hugepages= [HW] Number of HugeTLB pages to allocate at boot.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1579) If this follows hugepagesz (below), it specifies
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1580) the number of pages of hugepagesz to be allocated.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1581) If this is the first HugeTLB parameter on the command
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1582) line, it specifies the number of pages to allocate for
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1583) the default huge page size. See also
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1584) Documentation/admin-guide/mm/hugetlbpage.rst.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1585) Format: <integer>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1586)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1587) hugepagesz=
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1588) [HW] The size of the HugeTLB pages. This is used in
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1589) conjunction with hugepages (above) to allocate huge
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1590) pages of a specific size at boot. The pair
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1591) hugepagesz=X hugepages=Y can be specified once for
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1592) each supported huge page size. Huge page sizes are
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1593) architecture dependent. See also
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1594) Documentation/admin-guide/mm/hugetlbpage.rst.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1595) Format: size[KMG]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1596)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1597) hung_task_panic=
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1598) [KNL] Should the hung task detector generate panics.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1599) Format: 0 | 1
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1600)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1601) A value of 1 instructs the kernel to panic when a
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1602) hung task is detected. The default value is controlled
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1603) by the CONFIG_BOOTPARAM_HUNG_TASK_PANIC build-time
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1604) option. The value selected by this boot parameter can
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1605) be changed later by the kernel.hung_task_panic sysctl.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1606)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1607) hvc_iucv= [S390] Number of z/VM IUCV hypervisor console (HVC)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1608) terminal devices. Valid values: 0..8
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1609) hvc_iucv_allow= [S390] Comma-separated list of z/VM user IDs.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1610) If specified, z/VM IUCV HVC accepts connections
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1611) from listed z/VM user IDs only.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1612)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1613) hvc_dcc.enable= [ARM,ARM64] Enable DCC driver at runtime. For GKI,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1614) disabled at runtime by default to prevent
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1615) crashes in devices which do not support DCC.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1616)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1617) hv_nopvspin [X86,HYPER_V] Disables the paravirt spinlock optimizations
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1618) which allow the hypervisor to 'idle' the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1619) guest on lock contention.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1620)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1621) keep_bootcon [KNL]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1622) Do not unregister boot console at start. This is only
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1623) useful for debugging when something happens in the window
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1624) between unregistering the boot console and initializing
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1625) the real console.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1626)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1627) i2c_bus= [HW] Override the default board specific I2C bus speed
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1628) or register an additional I2C bus that is not
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1629) registered from board initialization code.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1630) Format:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1631) <bus_id>,<clkrate>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1632)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1633) i8042.debug [HW] Toggle i8042 debug mode
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1634) i8042.unmask_kbd_data
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1635) [HW] Enable printing of interrupt data from the KBD port
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1636) (disabled by default, and as a pre-condition
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1637) requires that i8042.debug=1 be enabled)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1638) i8042.direct [HW] Put keyboard port into non-translated mode
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1639) i8042.dumbkbd [HW] Pretend that controller can only read data from
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1640) keyboard and cannot control its state
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1641) (Don't attempt to blink the leds)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1642) i8042.noaux [HW] Don't check for auxiliary (== mouse) port
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1643) i8042.nokbd [HW] Don't check/create keyboard port
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1644) i8042.noloop [HW] Disable the AUX Loopback command while probing
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1645) for the AUX port
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1646) i8042.nomux [HW] Don't check presence of an active multiplexing
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1647) controller
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1648) i8042.nopnp [HW] Don't use ACPIPnP / PnPBIOS to discover KBD/AUX
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1649) controllers
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1650) i8042.notimeout [HW] Ignore timeout condition signalled by controller
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1651) i8042.reset [HW] Reset the controller during init, cleanup and
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1652) suspend-to-ram transitions, only during s2r
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1653) transitions, or never reset
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1654) Format: { 1 | Y | y | 0 | N | n }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1655) 1, Y, y: always reset controller
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1656) 0, N, n: don't ever reset controller
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1657) Default: only on s2r transitions on x86; most other
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1658) architectures force reset to be always executed
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1659) i8042.unlock [HW] Unlock (ignore) the keylock
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1660) i8042.kbdreset [HW] Reset device connected to KBD port
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1661) i8042.probe_defer
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1662) [HW] Allow deferred probing upon i8042 probe errors
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1663)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1664) i810= [HW,DRM]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1665)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1666) i8k.ignore_dmi [HW] Continue probing hardware even if DMI data
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1667) indicates that the driver is running on unsupported
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1668) hardware.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1669) i8k.force [HW] Activate i8k driver even if SMM BIOS signature
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1670) does not match list of supported models.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1671) i8k.power_status
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1672) [HW] Report power status in /proc/i8k
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1673) (disabled by default)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1674) i8k.restricted [HW] Allow controlling fans only if SYS_ADMIN
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1675) capability is set.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1676)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1677) i915.invert_brightness=
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1678) [DRM] Invert the sense of the variable that is used to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1679) set the brightness of the panel backlight. Normally a
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1680) brightness value of 0 indicates backlight switched off,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1681) and the maximum of the brightness value sets the backlight
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1682) to maximum brightness. If this parameter is set to 0
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1683) (default) and the machine requires it, or this parameter
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1684) is set to 1, a brightness value of 0 sets the backlight
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1685) to maximum brightness, and the maximum of the brightness
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1686) value switches the backlight off.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1687) -1 -- never invert brightness
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1688) 0 -- machine default
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1689) 1 -- force brightness inversion
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1690)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1691) icn= [HW,ISDN]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1692) Format: <io>[,<membase>[,<icn_id>[,<icn_id2>]]]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1693)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1694) ide-core.nodma= [HW] (E)IDE subsystem
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1695) Format: =0.0 to prevent dma on hda, =0.1 hdb =1.0 hdc
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1696) .vlb_clock .pci_clock .noflush .nohpa .noprobe .nowerr
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1697) .cdrom .chs .ignore_cable are additional options
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1698) See Documentation/ide/ide.rst.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1699)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1700) ide-generic.probe-mask= [HW] (E)IDE subsystem
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1701) Format: <int>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1702) Probe mask for legacy ISA IDE ports. Depending on
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1703) platform up to 6 ports are supported, enabled by
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1704) setting corresponding bits in the mask to 1. The
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1705) default value is 0x0, which has a special meaning.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1706) On systems that have PCI, it triggers scanning the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1707) PCI bus for the first and the second port, which
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1708) are then probed. On systems without PCI the value
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1709) of 0x0 enables probing the two first ports as if it
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1710) was 0x3.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1711)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1712) ide-pci-generic.all-generic-ide [HW] (E)IDE subsystem
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1713) Claim all unknown PCI IDE storage controllers.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1714)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1715) idle= [X86]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1716) Format: idle=poll, idle=halt, idle=nomwait
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1717) Poll forces a polling idle loop that can slightly
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1718) improve the performance of waking up a idle CPU, but
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1719) will use a lot of power and make the system run hot.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1720) Not recommended.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1721) idle=halt: Halt is forced to be used for CPU idle.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1722) In such case C2/C3 won't be used again.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1723) idle=nomwait: Disable mwait for CPU C-states
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1724)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1725) ieee754= [MIPS] Select IEEE Std 754 conformance mode
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1726) Format: { strict | legacy | 2008 | relaxed }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1727) Default: strict
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1728)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1729) Choose which programs will be accepted for execution
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1730) based on the IEEE 754 NaN encoding(s) supported by
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1731) the FPU and the NaN encoding requested with the value
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1732) of an ELF file header flag individually set by each
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1733) binary. Hardware implementations are permitted to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1734) support either or both of the legacy and the 2008 NaN
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1735) encoding mode.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1736)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1737) Available settings are as follows:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1738) strict accept binaries that request a NaN encoding
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1739) supported by the FPU
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1740) legacy only accept legacy-NaN binaries, if supported
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1741) by the FPU
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1742) 2008 only accept 2008-NaN binaries, if supported
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1743) by the FPU
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1744) relaxed accept any binaries regardless of whether
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1745) supported by the FPU
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1746)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1747) The FPU emulator is always able to support both NaN
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1748) encodings, so if no FPU hardware is present or it has
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1749) been disabled with 'nofpu', then the settings of
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1750) 'legacy' and '2008' strap the emulator accordingly,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1751) 'relaxed' straps the emulator for both legacy-NaN and
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1752) 2008-NaN, whereas 'strict' enables legacy-NaN only on
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1753) legacy processors and both NaN encodings on MIPS32 or
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1754) MIPS64 CPUs.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1755)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1756) The setting for ABS.fmt/NEG.fmt instruction execution
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1757) mode generally follows that for the NaN encoding,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1758) except where unsupported by hardware.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1759)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1760) ignore_loglevel [KNL]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1761) Ignore loglevel setting - this will print /all/
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1762) kernel messages to the console. Useful for debugging.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1763) We also add it as printk module parameter, so users
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1764) could change it dynamically, usually by
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1765) /sys/module/printk/parameters/ignore_loglevel.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1766)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1767) ignore_rlimit_data
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1768) Ignore RLIMIT_DATA setting for data mappings,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1769) print warning at first misuse. Can be changed via
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1770) /sys/module/kernel/parameters/ignore_rlimit_data.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1771)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1772) ihash_entries= [KNL]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1773) Set number of hash buckets for inode cache.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1774)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1775) ima_appraise= [IMA] appraise integrity measurements
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1776) Format: { "off" | "enforce" | "fix" | "log" }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1777) default: "enforce"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1778)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1779) ima_appraise_tcb [IMA] Deprecated. Use ima_policy= instead.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1780) The builtin appraise policy appraises all files
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1781) owned by uid=0.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1782)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1783) ima_canonical_fmt [IMA]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1784) Use the canonical format for the binary runtime
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1785) measurements, instead of host native format.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1786)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1787) ima_hash= [IMA]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1788) Format: { md5 | sha1 | rmd160 | sha256 | sha384
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1789) | sha512 | ... }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1790) default: "sha1"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1791)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1792) The list of supported hash algorithms is defined
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1793) in crypto/hash_info.h.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1794)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1795) ima_policy= [IMA]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1796) The builtin policies to load during IMA setup.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1797) Format: "tcb | appraise_tcb | secure_boot |
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1798) fail_securely"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1799)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1800) The "tcb" policy measures all programs exec'd, files
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1801) mmap'd for exec, and all files opened with the read
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1802) mode bit set by either the effective uid (euid=0) or
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1803) uid=0.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1804)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1805) The "appraise_tcb" policy appraises the integrity of
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1806) all files owned by root.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1807)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1808) The "secure_boot" policy appraises the integrity
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1809) of files (eg. kexec kernel image, kernel modules,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1810) firmware, policy, etc) based on file signatures.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1811)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1812) The "fail_securely" policy forces file signature
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1813) verification failure also on privileged mounted
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1814) filesystems with the SB_I_UNVERIFIABLE_SIGNATURE
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1815) flag.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1816)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1817) ima_tcb [IMA] Deprecated. Use ima_policy= instead.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1818) Load a policy which meets the needs of the Trusted
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1819) Computing Base. This means IMA will measure all
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1820) programs exec'd, files mmap'd for exec, and all files
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1821) opened for read by uid=0.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1822)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1823) ima_template= [IMA]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1824) Select one of defined IMA measurements template formats.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1825) Formats: { "ima" | "ima-ng" | "ima-sig" }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1826) Default: "ima-ng"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1827)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1828) ima_template_fmt=
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1829) [IMA] Define a custom template format.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1830) Format: { "field1|...|fieldN" }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1831)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1832) ima.ahash_minsize= [IMA] Minimum file size for asynchronous hash usage
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1833) Format: <min_file_size>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1834) Set the minimal file size for using asynchronous hash.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1835) If left unspecified, ahash usage is disabled.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1836)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1837) ahash performance varies for different data sizes on
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1838) different crypto accelerators. This option can be used
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1839) to achieve the best performance for a particular HW.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1840)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1841) ima.ahash_bufsize= [IMA] Asynchronous hash buffer size
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1842) Format: <bufsize>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1843) Set hashing buffer size. Default: 4k.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1844)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1845) ahash performance varies for different chunk sizes on
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1846) different crypto accelerators. This option can be used
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1847) to achieve best performance for particular HW.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1848)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1849) init= [KNL]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1850) Format: <full_path>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1851) Run specified binary instead of /sbin/init as init
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1852) process.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1853)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1854) initcall_debug [KNL] Trace initcalls as they are executed. Useful
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1855) for working out where the kernel is dying during
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1856) startup.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1857)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1858) initcall_blacklist= [KNL] Do not execute a comma-separated list of
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1859) initcall functions. Useful for debugging built-in
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1860) modules and initcalls.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1861)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1862) initrd= [BOOT] Specify the location of the initial ramdisk
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1863)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1864) initrdmem= [KNL] Specify a physical address and size from which to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1865) load the initrd. If an initrd is compiled in or
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1866) specified in the bootparams, it takes priority over this
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1867) setting.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1868) Format: ss[KMG],nn[KMG]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1869) Default is 0, 0
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1870)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1871) init_on_alloc= [MM] Fill newly allocated pages and heap objects with
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1872) zeroes.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1873) Format: 0 | 1
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1874) Default set by CONFIG_INIT_ON_ALLOC_DEFAULT_ON.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1875)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1876) init_on_free= [MM] Fill freed pages and heap objects with zeroes.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1877) Format: 0 | 1
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1878) Default set by CONFIG_INIT_ON_FREE_DEFAULT_ON.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1879)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1880) init_pkru= [X86] Specify the default memory protection keys rights
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1881) register contents for all processes. 0x55555554 by
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1882) default (disallow access to all but pkey 0). Can
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1883) override in debugfs after boot.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1884)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1885) inport.irq= [HW] Inport (ATI XL and Microsoft) busmouse driver
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1886) Format: <irq>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1887)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1888) int_pln_enable [X86] Enable power limit notification interrupt
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1889)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1890) integrity_audit=[IMA]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1891) Format: { "0" | "1" }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1892) 0 -- basic integrity auditing messages. (Default)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1893) 1 -- additional integrity auditing messages.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1894)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1895) intel_iommu= [DMAR] Intel IOMMU driver (DMAR) option
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1896) on
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1897) Enable intel iommu driver.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1898) off
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1899) Disable intel iommu driver.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1900) igfx_off [Default Off]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1901) By default, gfx is mapped as normal device. If a gfx
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1902) device has a dedicated DMAR unit, the DMAR unit is
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1903) bypassed by not enabling DMAR with this option. In
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1904) this case, gfx device will use physical address for
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1905) DMA.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1906) forcedac [X86-64]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1907) With this option iommu will not optimize to look
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1908) for io virtual address below 32-bit forcing dual
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1909) address cycle on pci bus for cards supporting greater
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1910) than 32-bit addressing. The default is to look
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1911) for translation below 32-bit and if not available
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1912) then look in the higher range.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1913) strict [Default Off]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1914) With this option on every unmap_single operation will
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1915) result in a hardware IOTLB flush operation as opposed
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1916) to batching them for performance.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1917) sp_off [Default Off]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1918) By default, super page will be supported if Intel IOMMU
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1919) has the capability. With this option, super page will
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1920) not be supported.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1921) sm_on [Default Off]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1922) By default, scalable mode will be disabled even if the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1923) hardware advertises that it has support for the scalable
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1924) mode translation. With this option set, scalable mode
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1925) will be used on hardware which claims to support it.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1926) tboot_noforce [Default Off]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1927) Do not force the Intel IOMMU enabled under tboot.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1928) By default, tboot will force Intel IOMMU on, which
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1929) could harm performance of some high-throughput
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1930) devices like 40GBit network cards, even if identity
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1931) mapping is enabled.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1932) Note that using this option lowers the security
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1933) provided by tboot because it makes the system
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1934) vulnerable to DMA attacks.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1935) nobounce [Default off]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1936) Disable bounce buffer for untrusted devices such as
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1937) the Thunderbolt devices. This will treat the untrusted
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1938) devices as the trusted ones, hence might expose security
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1939) risks of DMA attacks.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1940)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1941) intel_idle.max_cstate= [KNL,HW,ACPI,X86]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1942) 0 disables intel_idle and fall back on acpi_idle.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1943) 1 to 9 specify maximum depth of C-state.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1944)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1945) intel_pstate= [X86]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1946) disable
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1947) Do not enable intel_pstate as the default
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1948) scaling driver for the supported processors
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1949) passive
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1950) Use intel_pstate as a scaling driver, but configure it
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1951) to work with generic cpufreq governors (instead of
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1952) enabling its internal governor). This mode cannot be
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1953) used along with the hardware-managed P-states (HWP)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1954) feature.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1955) force
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1956) Enable intel_pstate on systems that prohibit it by default
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1957) in favor of acpi-cpufreq. Forcing the intel_pstate driver
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1958) instead of acpi-cpufreq may disable platform features, such
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1959) as thermal controls and power capping, that rely on ACPI
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1960) P-States information being indicated to OSPM and therefore
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1961) should be used with caution. This option does not work with
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1962) processors that aren't supported by the intel_pstate driver
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1963) or on platforms that use pcc-cpufreq instead of acpi-cpufreq.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1964) no_hwp
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1965) Do not enable hardware P state control (HWP)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1966) if available.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1967) hwp_only
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1968) Only load intel_pstate on systems which support
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1969) hardware P state control (HWP) if available.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1970) support_acpi_ppc
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1971) Enforce ACPI _PPC performance limits. If the Fixed ACPI
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1972) Description Table, specifies preferred power management
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1973) profile as "Enterprise Server" or "Performance Server",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1974) then this feature is turned on by default.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1975) per_cpu_perf_limits
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1976) Allow per-logical-CPU P-State performance control limits using
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1977) cpufreq sysfs interface
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1978)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1979) intremap= [X86-64, Intel-IOMMU]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1980) on enable Interrupt Remapping (default)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1981) off disable Interrupt Remapping
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1982) nosid disable Source ID checking
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1983) no_x2apic_optout
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1984) BIOS x2APIC opt-out request will be ignored
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1985) nopost disable Interrupt Posting
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1986)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1987) iomem= Disable strict checking of access to MMIO memory
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1988) strict regions from userspace.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1989) relaxed
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1990)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1991) iommu= [X86]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1992) off
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1993) force
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1994) noforce
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1995) biomerge
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1996) panic
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1997) nopanic
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1998) merge
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1999) nomerge
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2000) soft
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2001) pt [X86]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2002) nopt [X86]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2003) nobypass [PPC/POWERNV]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2004) Disable IOMMU bypass, using IOMMU for PCI devices.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2005)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2006) iommu.strict= [ARM64] Configure TLB invalidation behaviour
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2007) Format: { "0" | "1" }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2008) 0 - Lazy mode.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2009) Request that DMA unmap operations use deferred
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2010) invalidation of hardware TLBs, for increased
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2011) throughput at the cost of reduced device isolation.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2012) Will fall back to strict mode if not supported by
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2013) the relevant IOMMU driver.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2014) 1 - Strict mode (default).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2015) DMA unmap operations invalidate IOMMU hardware TLBs
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2016) synchronously.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2017)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2018) iommu.passthrough=
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2019) [ARM64, X86] Configure DMA to bypass the IOMMU by default.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2020) Format: { "0" | "1" }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2021) 0 - Use IOMMU translation for DMA.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2022) 1 - Bypass the IOMMU for DMA.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2023) unset - Use value of CONFIG_IOMMU_DEFAULT_PASSTHROUGH.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2024)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2025) io7= [HW] IO7 for Marvel-based Alpha systems
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2026) See comment before marvel_specify_io7 in
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2027) arch/alpha/kernel/core_marvel.c.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2028)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2029) io_delay= [X86] I/O delay method
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2030) 0x80
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2031) Standard port 0x80 based delay
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2032) 0xed
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2033) Alternate port 0xed based delay (needed on some systems)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2034) udelay
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2035) Simple two microseconds delay
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2036) none
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2037) No delay
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2038)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2039) ip= [IP_PNP]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2040) See Documentation/admin-guide/nfs/nfsroot.rst.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2041)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2042) ipcmni_extend [KNL] Extend the maximum number of unique System V
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2043) IPC identifiers from 32,768 to 16,777,216.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2044)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2045) irqaffinity= [SMP] Set the default irq affinity mask
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2046) The argument is a cpu list, as described above.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2047)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2048) irqchip.gicv2_force_probe=
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2049) [ARM, ARM64]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2050) Format: <bool>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2051) Force the kernel to look for the second 4kB page
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2052) of a GICv2 controller even if the memory range
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2053) exposed by the device tree is too small.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2054)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2055) irqchip.gicv3_nolpi=
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2056) [ARM, ARM64]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2057) Force the kernel to ignore the availability of
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2058) LPIs (and by consequence ITSs). Intended for system
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2059) that use the kernel as a bootloader, and thus want
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2060) to let secondary kernels in charge of setting up
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2061) LPIs.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2062)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2063) irqchip.gicv3_pseudo_nmi= [ARM64]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2064) Enables support for pseudo-NMIs in the kernel. This
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2065) requires the kernel to be built with
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2066) CONFIG_ARM64_PSEUDO_NMI.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2067)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2068) irqfixup [HW]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2069) When an interrupt is not handled search all handlers
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2070) for it. Intended to get systems with badly broken
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2071) firmware running.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2072)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2073) irqpoll [HW]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2074) When an interrupt is not handled search all handlers
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2075) for it. Also check all handlers each timer
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2076) interrupt. Intended to get systems with badly broken
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2077) firmware running.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2078)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2079) isapnp= [ISAPNP]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2080) Format: <RDP>,<reset>,<pci_scan>,<verbosity>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2081)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2082) isolcpus= [KNL,SMP,ISOL] Isolate a given set of CPUs from disturbance.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2083) [Deprecated - use cpusets instead]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2084) Format: [flag-list,]<cpu-list>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2085)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2086) Specify one or more CPUs to isolate from disturbances
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2087) specified in the flag list (default: domain):
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2088)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2089) nohz
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2090) Disable the tick when a single task runs.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2091)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2092) A residual 1Hz tick is offloaded to workqueues, which you
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2093) need to affine to housekeeping through the global
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2094) workqueue's affinity configured via the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2095) /sys/devices/virtual/workqueue/cpumask sysfs file, or
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2096) by using the 'domain' flag described below.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2097)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2098) NOTE: by default the global workqueue runs on all CPUs,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2099) so to protect individual CPUs the 'cpumask' file has to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2100) be configured manually after bootup.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2101)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2102) domain
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2103) Isolate from the general SMP balancing and scheduling
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2104) algorithms. Note that performing domain isolation this way
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2105) is irreversible: it's not possible to bring back a CPU to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2106) the domains once isolated through isolcpus. It's strongly
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2107) advised to use cpusets instead to disable scheduler load
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2108) balancing through the "cpuset.sched_load_balance" file.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2109) It offers a much more flexible interface where CPUs can
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2110) move in and out of an isolated set anytime.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2111)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2112) You can move a process onto or off an "isolated" CPU via
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2113) the CPU affinity syscalls or cpuset.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2114) <cpu number> begins at 0 and the maximum value is
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2115) "number of CPUs in system - 1".
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2116)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2117) managed_irq
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2118)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2119) Isolate from being targeted by managed interrupts
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2120) which have an interrupt mask containing isolated
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2121) CPUs. The affinity of managed interrupts is
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2122) handled by the kernel and cannot be changed via
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2123) the /proc/irq/* interfaces.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2124)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2125) This isolation is best effort and only effective
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2126) if the automatically assigned interrupt mask of a
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2127) device queue contains isolated and housekeeping
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2128) CPUs. If housekeeping CPUs are online then such
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2129) interrupts are directed to the housekeeping CPU
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2130) so that IO submitted on the housekeeping CPU
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2131) cannot disturb the isolated CPU.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2132)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2133) If a queue's affinity mask contains only isolated
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2134) CPUs then this parameter has no effect on the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2135) interrupt routing decision, though interrupts are
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2136) only delivered when tasks running on those
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2137) isolated CPUs submit IO. IO submitted on
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2138) housekeeping CPUs has no influence on those
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2139) queues.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2140)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2141) The format of <cpu-list> is described above.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2142)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2143) iucv= [HW,NET]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2144)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2145) ivrs_ioapic [HW,X86-64]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2146) Provide an override to the IOAPIC-ID<->DEVICE-ID
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2147) mapping provided in the IVRS ACPI table. For
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2148) example, to map IOAPIC-ID decimal 10 to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2149) PCI device 00:14.0 write the parameter as:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2150) ivrs_ioapic[10]=00:14.0
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2151)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2152) ivrs_hpet [HW,X86-64]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2153) Provide an override to the HPET-ID<->DEVICE-ID
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2154) mapping provided in the IVRS ACPI table. For
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2155) example, to map HPET-ID decimal 0 to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2156) PCI device 00:14.0 write the parameter as:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2157) ivrs_hpet[0]=00:14.0
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2158)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2159) ivrs_acpihid [HW,X86-64]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2160) Provide an override to the ACPI-HID:UID<->DEVICE-ID
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2161) mapping provided in the IVRS ACPI table. For
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2162) example, to map UART-HID:UID AMD0020:0 to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2163) PCI device 00:14.5 write the parameter as:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2164) ivrs_acpihid[00:14.5]=AMD0020:0
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2165)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2166) js= [HW,JOY] Analog joystick
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2167) See Documentation/input/joydev/joystick.rst.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2168)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2169) nokaslr [KNL]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2170) When CONFIG_RANDOMIZE_BASE is set, this disables
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2171) kernel and module base offset ASLR (Address Space
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2172) Layout Randomization).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2173)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2174) kasan_multi_shot
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2175) [KNL] Enforce KASAN (Kernel Address Sanitizer) to print
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2176) report on every invalid memory access. Without this
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2177) parameter KASAN will print report only for the first
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2178) invalid access.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2179)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2180) keepinitrd [HW,ARM]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2181)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2182) kernelcore= [KNL,X86,IA-64,PPC]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2183) Format: nn[KMGTPE] | nn% | "mirror"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2184) This parameter specifies the amount of memory usable by
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2185) the kernel for non-movable allocations. The requested
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2186) amount is spread evenly throughout all nodes in the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2187) system as ZONE_NORMAL. The remaining memory is used for
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2188) movable memory in its own zone, ZONE_MOVABLE. In the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2189) event, a node is too small to have both ZONE_NORMAL and
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2190) ZONE_MOVABLE, kernelcore memory will take priority and
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2191) other nodes will have a larger ZONE_MOVABLE.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2192)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2193) ZONE_MOVABLE is used for the allocation of pages that
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2194) may be reclaimed or moved by the page migration
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2195) subsystem. Note that allocations like PTEs-from-HighMem
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2196) still use the HighMem zone if it exists, and the Normal
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2197) zone if it does not.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2198)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2199) It is possible to specify the exact amount of memory in
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2200) the form of "nn[KMGTPE]", a percentage of total system
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2201) memory in the form of "nn%", or "mirror". If "mirror"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2202) option is specified, mirrored (reliable) memory is used
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2203) for non-movable allocations and remaining memory is used
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2204) for Movable pages. "nn[KMGTPE]", "nn%", and "mirror"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2205) are exclusive, so you cannot specify multiple forms.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2206)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2207) kgdbdbgp= [KGDB,HW] kgdb over EHCI usb debug port.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2208) Format: <Controller#>[,poll interval]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2209) The controller # is the number of the ehci usb debug
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2210) port as it is probed via PCI. The poll interval is
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2211) optional and is the number seconds in between
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2212) each poll cycle to the debug port in case you need
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2213) the functionality for interrupting the kernel with
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2214) gdb or control-c on the dbgp connection. When
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2215) not using this parameter you use sysrq-g to break into
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2216) the kernel debugger.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2217)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2218) kgdboc= [KGDB,HW] kgdb over consoles.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2219) Requires a tty driver that supports console polling,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2220) or a supported polling keyboard driver (non-usb).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2221) Serial only format: <serial_device>[,baud]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2222) keyboard only format: kbd
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2223) keyboard and serial format: kbd,<serial_device>[,baud]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2224) Optional Kernel mode setting:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2225) kms, kbd format: kms,kbd
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2226) kms, kbd and serial format: kms,kbd,<ser_dev>[,baud]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2227)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2228) kgdboc_earlycon= [KGDB,HW]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2229) If the boot console provides the ability to read
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2230) characters and can work in polling mode, you can use
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2231) this parameter to tell kgdb to use it as a backend
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2232) until the normal console is registered. Intended to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2233) be used together with the kgdboc parameter which
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2234) specifies the normal console to transition to.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2235)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2236) The name of the early console should be specified
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2237) as the value of this parameter. Note that the name of
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2238) the early console might be different than the tty
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2239) name passed to kgdboc. It's OK to leave the value
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2240) blank and the first boot console that implements
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2241) read() will be picked.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2242)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2243) kgdbwait [KGDB] Stop kernel execution and enter the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2244) kernel debugger at the earliest opportunity.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2245)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2246) kmac= [MIPS] Korina ethernet MAC address.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2247) Configure the RouterBoard 532 series on-chip
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2248) Ethernet adapter MAC address.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2249)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2250) kmemleak= [KNL] Boot-time kmemleak enable/disable
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2251) Valid arguments: on, off
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2252) Default: on
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2253) Built with CONFIG_DEBUG_KMEMLEAK_DEFAULT_OFF=y,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2254) the default is off.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2255)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2256) kprobe_event=[probe-list]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2257) [FTRACE] Add kprobe events and enable at boot time.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2258) The probe-list is a semicolon delimited list of probe
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2259) definitions. Each definition is same as kprobe_events
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2260) interface, but the parameters are comma delimited.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2261) For example, to add a kprobe event on vfs_read with
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2262) arg1 and arg2, add to the command line;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2263)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2264) kprobe_event=p,vfs_read,$arg1,$arg2
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2265)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2266) See also Documentation/trace/kprobetrace.rst "Kernel
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2267) Boot Parameter" section.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2268)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2269) kpti= [ARM64] Control page table isolation of user
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2270) and kernel address spaces.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2271) Default: enabled on cores which need mitigation.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2272) 0: force disabled
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2273) 1: force enabled
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2274)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2275) kvm.ignore_msrs=[KVM] Ignore guest accesses to unhandled MSRs.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2276) Default is 0 (don't ignore, but inject #GP)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2277)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2278) kvm.enable_vmware_backdoor=[KVM] Support VMware backdoor PV interface.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2279) Default is false (don't support).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2280)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2281) kvm.mmu_audit= [KVM] This is a R/W parameter which allows audit
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2282) KVM MMU at runtime.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2283) Default is 0 (off)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2284)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2285) kvm.nx_huge_pages=
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2286) [KVM] Controls the software workaround for the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2287) X86_BUG_ITLB_MULTIHIT bug.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2288) force : Always deploy workaround.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2289) off : Never deploy workaround.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2290) auto : Deploy workaround based on the presence of
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2291) X86_BUG_ITLB_MULTIHIT.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2292)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2293) Default is 'auto'.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2294)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2295) If the software workaround is enabled for the host,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2296) guests do need not to enable it for nested guests.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2297)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2298) kvm.nx_huge_pages_recovery_ratio=
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2299) [KVM] Controls how many 4KiB pages are periodically zapped
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2300) back to huge pages. 0 disables the recovery, otherwise if
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2301) the value is N KVM will zap 1/Nth of the 4KiB pages every
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2302) minute. The default is 60.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2303)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2304) kvm-amd.nested= [KVM,AMD] Allow nested virtualization in KVM/SVM.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2305) Default is 1 (enabled)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2306)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2307) kvm-amd.npt= [KVM,AMD] Disable nested paging (virtualized MMU)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2308) for all guests.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2309) Default is 1 (enabled) if in 64-bit or 32-bit PAE mode.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2310)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2311) kvm-arm.mode=
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2312) [KVM,ARM] Select one of KVM/arm64's modes of operation.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2313)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2314) nvhe: Standard nVHE-based mode, without support for
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2315) protected guests.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2316)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2317) protected: nVHE-based mode with support for guests whose
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2318) state is kept private from the host.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2319) Not valid if the kernel is running in EL2.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2320)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2321) Defaults to VHE/nVHE based on hardware support and
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2322) the value of CONFIG_ARM64_VHE.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2323)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2324) kvm-arm.vgic_v3_group0_trap=
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2325) [KVM,ARM] Trap guest accesses to GICv3 group-0
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2326) system registers
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2327)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2328) kvm-arm.vgic_v3_group1_trap=
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2329) [KVM,ARM] Trap guest accesses to GICv3 group-1
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2330) system registers
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2331)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2332) kvm-arm.vgic_v3_common_trap=
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2333) [KVM,ARM] Trap guest accesses to GICv3 common
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2334) system registers
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2335)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2336) kvm-arm.vgic_v4_enable=
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2337) [KVM,ARM] Allow use of GICv4 for direct injection of
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2338) LPIs.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2339)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2340) kvm_cma_resv_ratio=n [PPC]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2341) Reserves given percentage from system memory area for
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2342) contiguous memory allocation for KVM hash pagetable
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2343) allocation.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2344) By default it reserves 5% of total system memory.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2345) Format: <integer>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2346) Default: 5
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2347)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2348) kvm-intel.ept= [KVM,Intel] Disable extended page tables
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2349) (virtualized MMU) support on capable Intel chips.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2350) Default is 1 (enabled)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2351)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2352) kvm-intel.emulate_invalid_guest_state=
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2353) [KVM,Intel] Disable emulation of invalid guest state.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2354) Ignored if kvm-intel.enable_unrestricted_guest=1, as
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2355) guest state is never invalid for unrestricted guests.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2356) This param doesn't apply to nested guests (L2), as KVM
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2357) never emulates invalid L2 guest state.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2358) Default is 1 (enabled)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2359)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2360) kvm-intel.flexpriority=
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2361) [KVM,Intel] Disable FlexPriority feature (TPR shadow).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2362) Default is 1 (enabled)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2363)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2364) kvm-intel.nested=
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2365) [KVM,Intel] Enable VMX nesting (nVMX).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2366) Default is 0 (disabled)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2367)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2368) kvm-intel.unrestricted_guest=
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2369) [KVM,Intel] Disable unrestricted guest feature
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2370) (virtualized real and unpaged mode) on capable
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2371) Intel chips. Default is 1 (enabled)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2372)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2373) kvm-intel.vmentry_l1d_flush=[KVM,Intel] Mitigation for L1 Terminal Fault
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2374) CVE-2018-3620.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2375)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2376) Valid arguments: never, cond, always
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2377)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2378) always: L1D cache flush on every VMENTER.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2379) cond: Flush L1D on VMENTER only when the code between
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2380) VMEXIT and VMENTER can leak host memory.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2381) never: Disables the mitigation
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2382)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2383) Default is cond (do L1 cache flush in specific instances)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2384)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2385) kvm-intel.vpid= [KVM,Intel] Disable Virtual Processor Identification
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2386) feature (tagged TLBs) on capable Intel chips.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2387) Default is 1 (enabled)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2388)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2389) l1tf= [X86] Control mitigation of the L1TF vulnerability on
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2390) affected CPUs
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2391)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2392) The kernel PTE inversion protection is unconditionally
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2393) enabled and cannot be disabled.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2394)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2395) full
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2396) Provides all available mitigations for the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2397) L1TF vulnerability. Disables SMT and
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2398) enables all mitigations in the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2399) hypervisors, i.e. unconditional L1D flush.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2400)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2401) SMT control and L1D flush control via the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2402) sysfs interface is still possible after
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2403) boot. Hypervisors will issue a warning
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2404) when the first VM is started in a
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2405) potentially insecure configuration,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2406) i.e. SMT enabled or L1D flush disabled.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2407)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2408) full,force
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2409) Same as 'full', but disables SMT and L1D
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2410) flush runtime control. Implies the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2411) 'nosmt=force' command line option.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2412) (i.e. sysfs control of SMT is disabled.)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2413)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2414) flush
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2415) Leaves SMT enabled and enables the default
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2416) hypervisor mitigation, i.e. conditional
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2417) L1D flush.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2418)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2419) SMT control and L1D flush control via the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2420) sysfs interface is still possible after
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2421) boot. Hypervisors will issue a warning
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2422) when the first VM is started in a
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2423) potentially insecure configuration,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2424) i.e. SMT enabled or L1D flush disabled.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2425)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2426) flush,nosmt
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2427)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2428) Disables SMT and enables the default
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2429) hypervisor mitigation.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2430)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2431) SMT control and L1D flush control via the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2432) sysfs interface is still possible after
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2433) boot. Hypervisors will issue a warning
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2434) when the first VM is started in a
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2435) potentially insecure configuration,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2436) i.e. SMT enabled or L1D flush disabled.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2437)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2438) flush,nowarn
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2439) Same as 'flush', but hypervisors will not
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2440) warn when a VM is started in a potentially
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2441) insecure configuration.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2442)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2443) off
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2444) Disables hypervisor mitigations and doesn't
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2445) emit any warnings.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2446) It also drops the swap size and available
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2447) RAM limit restriction on both hypervisor and
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2448) bare metal.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2449)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2450) Default is 'flush'.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2451)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2452) For details see: Documentation/admin-guide/hw-vuln/l1tf.rst
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2453)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2454) l2cr= [PPC]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2455)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2456) l3cr= [PPC]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2457)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2458) lapic [X86-32,APIC] Enable the local APIC even if BIOS
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2459) disabled it.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2460)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2461) lapic= [X86,APIC] Do not use TSC deadline
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2462) value for LAPIC timer one-shot implementation. Default
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2463) back to the programmable timer unit in the LAPIC.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2464) Format: notscdeadline
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2465)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2466) lapic_timer_c2_ok [X86,APIC] trust the local apic timer
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2467) in C2 power state.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2468)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2469) libata.dma= [LIBATA] DMA control
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2470) libata.dma=0 Disable all PATA and SATA DMA
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2471) libata.dma=1 PATA and SATA Disk DMA only
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2472) libata.dma=2 ATAPI (CDROM) DMA only
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2473) libata.dma=4 Compact Flash DMA only
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2474) Combinations also work, so libata.dma=3 enables DMA
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2475) for disks and CDROMs, but not CFs.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2476)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2477) libata.ignore_hpa= [LIBATA] Ignore HPA limit
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2478) libata.ignore_hpa=0 keep BIOS limits (default)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2479) libata.ignore_hpa=1 ignore limits, using full disk
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2480)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2481) libata.noacpi [LIBATA] Disables use of ACPI in libata suspend/resume
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2482) when set.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2483) Format: <int>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2484)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2485) libata.force= [LIBATA] Force configurations. The format is comma
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2486) separated list of "[ID:]VAL" where ID is
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2487) PORT[.DEVICE]. PORT and DEVICE are decimal numbers
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2488) matching port, link or device. Basically, it matches
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2489) the ATA ID string printed on console by libata. If
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2490) the whole ID part is omitted, the last PORT and DEVICE
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2491) values are used. If ID hasn't been specified yet, the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2492) configuration applies to all ports, links and devices.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2493)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2494) If only DEVICE is omitted, the parameter applies to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2495) the port and all links and devices behind it. DEVICE
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2496) number of 0 either selects the first device or the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2497) first fan-out link behind PMP device. It does not
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2498) select the host link. DEVICE number of 15 selects the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2499) host link and device attached to it.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2500)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2501) The VAL specifies the configuration to force. As long
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2502) as there's no ambiguity shortcut notation is allowed.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2503) For example, both 1.5 and 1.5G would work for 1.5Gbps.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2504) The following configurations can be forced.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2505)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2506) * Cable type: 40c, 80c, short40c, unk, ign or sata.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2507) Any ID with matching PORT is used.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2508)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2509) * SATA link speed limit: 1.5Gbps or 3.0Gbps.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2510)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2511) * Transfer mode: pio[0-7], mwdma[0-4] and udma[0-7].
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2512) udma[/][16,25,33,44,66,100,133] notation is also
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2513) allowed.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2514)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2515) * [no]ncq: Turn on or off NCQ.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2516)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2517) * [no]ncqtrim: Turn off queued DSM TRIM.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2518)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2519) * nohrst, nosrst, norst: suppress hard, soft
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2520) and both resets.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2521)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2522) * rstonce: only attempt one reset during
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2523) hot-unplug link recovery
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2524)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2525) * dump_id: dump IDENTIFY data.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2526)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2527) * atapi_dmadir: Enable ATAPI DMADIR bridge support
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2528)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2529) * disable: Disable this device.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2530)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2531) If there are multiple matching configurations changing
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2532) the same attribute, the last one is used.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2533)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2534) memblock=debug [KNL] Enable memblock debug messages.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2535)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2536) load_ramdisk= [RAM] [Deprecated]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2537)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2538) lockd.nlm_grace_period=P [NFS] Assign grace period.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2539) Format: <integer>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2540)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2541) lockd.nlm_tcpport=N [NFS] Assign TCP port.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2542) Format: <integer>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2543)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2544) lockd.nlm_timeout=T [NFS] Assign timeout value.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2545) Format: <integer>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2546)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2547) lockd.nlm_udpport=M [NFS] Assign UDP port.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2548) Format: <integer>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2549)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2550) lockdown= [SECURITY]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2551) { integrity | confidentiality }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2552) Enable the kernel lockdown feature. If set to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2553) integrity, kernel features that allow userland to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2554) modify the running kernel are disabled. If set to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2555) confidentiality, kernel features that allow userland
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2556) to extract confidential information from the kernel
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2557) are also disabled.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2558)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2559) locktorture.nreaders_stress= [KNL]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2560) Set the number of locking read-acquisition kthreads.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2561) Defaults to being automatically set based on the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2562) number of online CPUs.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2563)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2564) locktorture.nwriters_stress= [KNL]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2565) Set the number of locking write-acquisition kthreads.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2566)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2567) locktorture.onoff_holdoff= [KNL]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2568) Set time (s) after boot for CPU-hotplug testing.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2569)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2570) locktorture.onoff_interval= [KNL]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2571) Set time (s) between CPU-hotplug operations, or
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2572) zero to disable CPU-hotplug testing.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2573)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2574) locktorture.shuffle_interval= [KNL]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2575) Set task-shuffle interval (jiffies). Shuffling
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2576) tasks allows some CPUs to go into dyntick-idle
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2577) mode during the locktorture test.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2578)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2579) locktorture.shutdown_secs= [KNL]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2580) Set time (s) after boot system shutdown. This
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2581) is useful for hands-off automated testing.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2582)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2583) locktorture.stat_interval= [KNL]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2584) Time (s) between statistics printk()s.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2585)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2586) locktorture.stutter= [KNL]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2587) Time (s) to stutter testing, for example,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2588) specifying five seconds causes the test to run for
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2589) five seconds, wait for five seconds, and so on.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2590) This tests the locking primitive's ability to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2591) transition abruptly to and from idle.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2592)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2593) locktorture.torture_type= [KNL]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2594) Specify the locking implementation to test.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2595)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2596) locktorture.verbose= [KNL]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2597) Enable additional printk() statements.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2598)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2599) logibm.irq= [HW,MOUSE] Logitech Bus Mouse Driver
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2600) Format: <irq>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2601)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2602) loglevel= All Kernel Messages with a loglevel smaller than the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2603) console loglevel will be printed to the console. It can
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2604) also be changed with klogd or other programs. The
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2605) loglevels are defined as follows:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2606)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2607) 0 (KERN_EMERG) system is unusable
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2608) 1 (KERN_ALERT) action must be taken immediately
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2609) 2 (KERN_CRIT) critical conditions
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2610) 3 (KERN_ERR) error conditions
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2611) 4 (KERN_WARNING) warning conditions
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2612) 5 (KERN_NOTICE) normal but significant condition
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2613) 6 (KERN_INFO) informational
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2614) 7 (KERN_DEBUG) debug-level messages
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2615)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2616) log_buf_len=n[KMG] Sets the size of the printk ring buffer,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2617) in bytes. n must be a power of two and greater
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2618) than the minimal size. The minimal size is defined
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2619) by LOG_BUF_SHIFT kernel config parameter. There is
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2620) also CONFIG_LOG_CPU_MAX_BUF_SHIFT config parameter
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2621) that allows to increase the default size depending on
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2622) the number of CPUs. See init/Kconfig for more details.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2623)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2624) logo.nologo [FB] Disables display of the built-in Linux logo.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2625) This may be used to provide more screen space for
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2626) kernel log messages and is useful when debugging
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2627) kernel boot problems.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2628)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2629) lp=0 [LP] Specify parallel ports to use, e.g,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2630) lp=port[,port...] lp=none,parport0 (lp0 not configured, lp1 uses
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2631) lp=reset first parallel port). 'lp=0' disables the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2632) lp=auto printer driver. 'lp=reset' (which can be
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2633) specified in addition to the ports) causes
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2634) attached printers to be reset. Using
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2635) lp=port1,port2,... specifies the parallel ports
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2636) to associate lp devices with, starting with
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2637) lp0. A port specification may be 'none' to skip
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2638) that lp device, or a parport name such as
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2639) 'parport0'. Specifying 'lp=auto' instead of a
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2640) port specification list means that device IDs
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2641) from each port should be examined, to see if
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2642) an IEEE 1284-compliant printer is attached; if
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2643) so, the driver will manage that printer.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2644) See also header of drivers/char/lp.c.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2645)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2646) lpj=n [KNL]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2647) Sets loops_per_jiffy to given constant, thus avoiding
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2648) time-consuming boot-time autodetection (up to 250 ms per
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2649) CPU). 0 enables autodetection (default). To determine
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2650) the correct value for your kernel, boot with normal
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2651) autodetection and see what value is printed. Note that
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2652) on SMP systems the preset will be applied to all CPUs,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2653) which is likely to cause problems if your CPUs need
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2654) significantly divergent settings. An incorrect value
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2655) will cause delays in the kernel to be wrong, leading to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2656) unpredictable I/O errors and other breakage. Although
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2657) unlikely, in the extreme case this might damage your
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2658) hardware.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2659)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2660) ltpc= [NET]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2661) Format: <io>,<irq>,<dma>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2662)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2663) lsm.debug [SECURITY] Enable LSM initialization debugging output.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2664)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2665) lsm=lsm1,...,lsmN
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2666) [SECURITY] Choose order of LSM initialization. This
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2667) overrides CONFIG_LSM, and the "security=" parameter.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2668)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2669) machvec= [IA-64] Force the use of a particular machine-vector
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2670) (machvec) in a generic kernel.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2671) Example: machvec=hpzx1
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2672)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2673) machtype= [Loongson] Share the same kernel image file between
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2674) different yeeloong laptops.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2675) Example: machtype=lemote-yeeloong-2f-7inch
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2676)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2677) max_addr=nn[KMG] [KNL,BOOT,ia64] All physical memory greater
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2678) than or equal to this physical address is ignored.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2679)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2680) maxcpus= [SMP] Maximum number of processors that an SMP kernel
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2681) will bring up during bootup. maxcpus=n : n >= 0 limits
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2682) the kernel to bring up 'n' processors. Surely after
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2683) bootup you can bring up the other plugged cpu by executing
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2684) "echo 1 > /sys/devices/system/cpu/cpuX/online". So maxcpus
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2685) only takes effect during system bootup.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2686) While n=0 is a special case, it is equivalent to "nosmp",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2687) which also disables the IO APIC.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2688)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2689) max_loop= [LOOP] The number of loop block devices that get
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2690) (loop.max_loop) unconditionally pre-created at init time. The default
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2691) number is configured by BLK_DEV_LOOP_MIN_COUNT. Instead
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2692) of statically allocating a predefined number, loop
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2693) devices can be requested on-demand with the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2694) /dev/loop-control interface.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2695)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2696) mce [X86-32] Machine Check Exception
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2697)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2698) mce=option [X86-64] See Documentation/x86/x86_64/boot-options.rst
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2699)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2700) md= [HW] RAID subsystems devices and level
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2701) See Documentation/admin-guide/md.rst.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2702)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2703) mdacon= [MDA]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2704) Format: <first>,<last>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2705) Specifies range of consoles to be captured by the MDA.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2706)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2707) mds= [X86,INTEL]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2708) Control mitigation for the Micro-architectural Data
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2709) Sampling (MDS) vulnerability.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2710)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2711) Certain CPUs are vulnerable to an exploit against CPU
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2712) internal buffers which can forward information to a
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2713) disclosure gadget under certain conditions.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2714)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2715) In vulnerable processors, the speculatively
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2716) forwarded data can be used in a cache side channel
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2717) attack, to access data to which the attacker does
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2718) not have direct access.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2719)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2720) This parameter controls the MDS mitigation. The
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2721) options are:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2722)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2723) full - Enable MDS mitigation on vulnerable CPUs
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2724) full,nosmt - Enable MDS mitigation and disable
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2725) SMT on vulnerable CPUs
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2726) off - Unconditionally disable MDS mitigation
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2727)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2728) On TAA-affected machines, mds=off can be prevented by
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2729) an active TAA mitigation as both vulnerabilities are
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2730) mitigated with the same mechanism so in order to disable
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2731) this mitigation, you need to specify tsx_async_abort=off
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2732) too.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2733)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2734) Not specifying this option is equivalent to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2735) mds=full.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2736)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2737) For details see: Documentation/admin-guide/hw-vuln/mds.rst
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2738)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2739) mem=nn[KMG] [KNL,BOOT] Force usage of a specific amount of memory
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2740) Amount of memory to be used in cases as follows:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2741)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2742) 1 for test;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2743) 2 when the kernel is not able to see the whole system memory;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2744) 3 memory that lies after 'mem=' boundary is excluded from
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2745) the hypervisor, then assigned to KVM guests.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2746)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2747) [X86] Work as limiting max address. Use together
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2748) with memmap= to avoid physical address space collisions.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2749) Without memmap= PCI devices could be placed at addresses
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2750) belonging to unused RAM.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2751)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2752) Note that this only takes effects during boot time since
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2753) in above case 3, memory may need be hot added after boot
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2754) if system memory of hypervisor is not sufficient.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2755)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2756) mem=nopentium [BUGS=X86-32] Disable usage of 4MB pages for kernel
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2757) memory.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2758)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2759) memchunk=nn[KMG]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2760) [KNL,SH] Allow user to override the default size for
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2761) per-device physically contiguous DMA buffers.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2762)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2763) memhp_default_state=online/offline
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2764) [KNL] Set the initial state for the memory hotplug
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2765) onlining policy. If not specified, the default value is
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2766) set according to the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2767) CONFIG_MEMORY_HOTPLUG_DEFAULT_ONLINE kernel config
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2768) option.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2769) See Documentation/admin-guide/mm/memory-hotplug.rst.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2770)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2771) memmap=exactmap [KNL,X86] Enable setting of an exact
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2772) E820 memory map, as specified by the user.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2773) Such memmap=exactmap lines can be constructed based on
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2774) BIOS output or other requirements. See the memmap=nn@ss
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2775) option description.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2776)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2777) memmap=nn[KMG]@ss[KMG]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2778) [KNL] Force usage of a specific region of memory.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2779) Region of memory to be used is from ss to ss+nn.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2780) If @ss[KMG] is omitted, it is equivalent to mem=nn[KMG],
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2781) which limits max address to nn[KMG].
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2782) Multiple different regions can be specified,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2783) comma delimited.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2784) Example:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2785) memmap=100M@2G,100M#3G,1G!1024G
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2786)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2787) memmap=nn[KMG]#ss[KMG]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2788) [KNL,ACPI] Mark specific memory as ACPI data.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2789) Region of memory to be marked is from ss to ss+nn.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2790)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2791) memmap=nn[KMG]$ss[KMG]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2792) [KNL,ACPI] Mark specific memory as reserved.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2793) Region of memory to be reserved is from ss to ss+nn.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2794) Example: Exclude memory from 0x18690000-0x1869ffff
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2795) memmap=64K$0x18690000
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2796) or
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2797) memmap=0x10000$0x18690000
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2798) Some bootloaders may need an escape character before '$',
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2799) like Grub2, otherwise '$' and the following number
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2800) will be eaten.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2801)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2802) memmap=nn[KMG]!ss[KMG]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2803) [KNL,X86] Mark specific memory as protected.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2804) Region of memory to be used, from ss to ss+nn.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2805) The memory region may be marked as e820 type 12 (0xc)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2806) and is NVDIMM or ADR memory.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2807)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2808) memmap=<size>%<offset>-<oldtype>+<newtype>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2809) [KNL,ACPI] Convert memory within the specified region
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2810) from <oldtype> to <newtype>. If "-<oldtype>" is left
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2811) out, the whole region will be marked as <newtype>,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2812) even if previously unavailable. If "+<newtype>" is left
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2813) out, matching memory will be removed. Types are
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2814) specified as e820 types, e.g., 1 = RAM, 2 = reserved,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2815) 3 = ACPI, 12 = PRAM.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2816)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2817) memory_corruption_check=0/1 [X86]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2818) Some BIOSes seem to corrupt the first 64k of
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2819) memory when doing things like suspend/resume.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2820) Setting this option will scan the memory
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2821) looking for corruption. Enabling this will
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2822) both detect corruption and prevent the kernel
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2823) from using the memory being corrupted.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2824) However, its intended as a diagnostic tool; if
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2825) repeatable BIOS-originated corruption always
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2826) affects the same memory, you can use memmap=
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2827) to prevent the kernel from using that memory.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2828)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2829) memory_corruption_check_size=size [X86]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2830) By default it checks for corruption in the low
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2831) 64k, making this memory unavailable for normal
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2832) use. Use this parameter to scan for
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2833) corruption in more or less memory.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2834)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2835) memory_corruption_check_period=seconds [X86]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2836) By default it checks for corruption every 60
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2837) seconds. Use this parameter to check at some
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2838) other rate. 0 disables periodic checking.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2839)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2840) memtest= [KNL,X86,ARM,PPC] Enable memtest
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2841) Format: <integer>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2842) default : 0 <disable>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2843) Specifies the number of memtest passes to be
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2844) performed. Each pass selects another test
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2845) pattern from a given set of patterns. Memtest
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2846) fills the memory with this pattern, validates
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2847) memory contents and reserves bad memory
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2848) regions that are detected.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2849)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2850) mem_encrypt= [X86-64] AMD Secure Memory Encryption (SME) control
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2851) Valid arguments: on, off
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2852) Default (depends on kernel configuration option):
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2853) on (CONFIG_AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT=y)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2854) off (CONFIG_AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT=n)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2855) mem_encrypt=on: Activate SME
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2856) mem_encrypt=off: Do not activate SME
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2857)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2858) Refer to Documentation/virt/kvm/amd-memory-encryption.rst
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2859) for details on when memory encryption can be activated.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2860)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2861) mem_sleep_default= [SUSPEND] Default system suspend mode:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2862) s2idle - Suspend-To-Idle
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2863) shallow - Power-On Suspend or equivalent (if supported)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2864) deep - Suspend-To-RAM or equivalent (if supported)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2865) See Documentation/admin-guide/pm/sleep-states.rst.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2866)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2867) meye.*= [HW] Set MotionEye Camera parameters
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2868) See Documentation/admin-guide/media/meye.rst.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2869)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2870) mfgpt_irq= [IA-32] Specify the IRQ to use for the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2871) Multi-Function General Purpose Timers on AMD Geode
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2872) platforms.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2873)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2874) mfgptfix [X86-32] Fix MFGPT timers on AMD Geode platforms when
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2875) the BIOS has incorrectly applied a workaround. TinyBIOS
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2876) version 0.98 is known to be affected, 0.99 fixes the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2877) problem by letting the user disable the workaround.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2878)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2879) mga= [HW,DRM]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2880)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2881) min_addr=nn[KMG] [KNL,BOOT,ia64] All physical memory below this
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2882) physical address is ignored.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2883)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2884) mini2440= [ARM,HW,KNL]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2885) Format:[0..2][b][c][t]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2886) Default: "0tb"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2887) MINI2440 configuration specification:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2888) 0 - The attached screen is the 3.5" TFT
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2889) 1 - The attached screen is the 7" TFT
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2890) 2 - The VGA Shield is attached (1024x768)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2891) Leaving out the screen size parameter will not load
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2892) the TFT driver, and the framebuffer will be left
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2893) unconfigured.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2894) b - Enable backlight. The TFT backlight pin will be
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2895) linked to the kernel VESA blanking code and a GPIO
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2896) LED. This parameter is not necessary when using the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2897) VGA shield.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2898) c - Enable the s3c camera interface.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2899) t - Reserved for enabling touchscreen support. The
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2900) touchscreen support is not enabled in the mainstream
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2901) kernel as of 2.6.30, a preliminary port can be found
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2902) in the "bleeding edge" mini2440 support kernel at
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2903) https://repo.or.cz/w/linux-2.6/mini2440.git
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2904)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2905) mitigations=
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2906) [X86,PPC,S390,ARM64] Control optional mitigations for
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2907) CPU vulnerabilities. This is a set of curated,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2908) arch-independent options, each of which is an
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2909) aggregation of existing arch-specific options.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2910)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2911) off
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2912) Disable all optional CPU mitigations. This
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2913) improves system performance, but it may also
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2914) expose users to several CPU vulnerabilities.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2915) Equivalent to: nopti [X86,PPC]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2916) kpti=0 [ARM64]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2917) nospectre_v1 [X86,PPC]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2918) nobp=0 [S390]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2919) nospectre_v2 [X86,PPC,S390,ARM64]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2920) spectre_v2_user=off [X86]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2921) spec_store_bypass_disable=off [X86,PPC]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2922) ssbd=force-off [ARM64]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2923) l1tf=off [X86]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2924) mds=off [X86]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2925) tsx_async_abort=off [X86]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2926) kvm.nx_huge_pages=off [X86]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2927) no_entry_flush [PPC]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2928) no_uaccess_flush [PPC]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2929)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2930) Exceptions:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2931) This does not have any effect on
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2932) kvm.nx_huge_pages when
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2933) kvm.nx_huge_pages=force.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2934)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2935) auto (default)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2936) Mitigate all CPU vulnerabilities, but leave SMT
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2937) enabled, even if it's vulnerable. This is for
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2938) users who don't want to be surprised by SMT
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2939) getting disabled across kernel upgrades, or who
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2940) have other ways of avoiding SMT-based attacks.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2941) Equivalent to: (default behavior)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2942)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2943) auto,nosmt
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2944) Mitigate all CPU vulnerabilities, disabling SMT
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2945) if needed. This is for users who always want to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2946) be fully mitigated, even if it means losing SMT.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2947) Equivalent to: l1tf=flush,nosmt [X86]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2948) mds=full,nosmt [X86]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2949) tsx_async_abort=full,nosmt [X86]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2950)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2951) mminit_loglevel=
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2952) [KNL] When CONFIG_DEBUG_MEMORY_INIT is set, this
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2953) parameter allows control of the logging verbosity for
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2954) the additional memory initialisation checks. A value
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2955) of 0 disables mminit logging and a level of 4 will
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2956) log everything. Information is printed at KERN_DEBUG
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2957) so loglevel=8 may also need to be specified.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2958)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2959) module.sig_enforce
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2960) [KNL] When CONFIG_MODULE_SIG is set, this means that
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2961) modules without (valid) signatures will fail to load.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2962) Note that if CONFIG_MODULE_SIG_FORCE is set, that
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2963) is always true, so this option does nothing.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2964)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2965) module_blacklist= [KNL] Do not load a comma-separated list of
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2966) modules. Useful for debugging problem modules.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2967)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2968) mousedev.tap_time=
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2969) [MOUSE] Maximum time between finger touching and
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2970) leaving touchpad surface for touch to be considered
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2971) a tap and be reported as a left button click (for
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2972) touchpads working in absolute mode only).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2973) Format: <msecs>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2974) mousedev.xres= [MOUSE] Horizontal screen resolution, used for devices
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2975) reporting absolute coordinates, such as tablets
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2976) mousedev.yres= [MOUSE] Vertical screen resolution, used for devices
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2977) reporting absolute coordinates, such as tablets
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2978)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2979) movablecore= [KNL,X86,IA-64,PPC]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2980) Format: nn[KMGTPE] | nn%
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2981) This parameter is the complement to kernelcore=, it
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2982) specifies the amount of memory used for migratable
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2983) allocations. If both kernelcore and movablecore is
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2984) specified, then kernelcore will be at *least* the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2985) specified value but may be more. If movablecore on its
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2986) own is specified, the administrator must be careful
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2987) that the amount of memory usable for all allocations
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2988) is not too small.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2989)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2990) movable_node [KNL] Boot-time switch to make hotplugable memory
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2991) NUMA nodes to be movable. This means that the memory
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2992) of such nodes will be usable only for movable
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2993) allocations which rules out almost all kernel
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2994) allocations. Use with caution!
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2995)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2996) MTD_Partition= [MTD]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2997) Format: <name>,<region-number>,<size>,<offset>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2998)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2999) MTD_Region= [MTD] Format:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3000) <name>,<region-number>[,<base>,<size>,<buswidth>,<altbuswidth>]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3001)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3002) mtdparts= [MTD]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3003) See drivers/mtd/parsers/cmdlinepart.c
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3004)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3005) multitce=off [PPC] This parameter disables the use of the pSeries
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3006) firmware feature for updating multiple TCE entries
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3007) at a time.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3008)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3009) kswapd_per_node=
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3010) kswapd_per_node allows you to control the number of kswapd threads
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3011) running on the system. This provides the ability to devote additional
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3012) CPU resources toward proactive page replacement with the goal of
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3013) reducing direct reclaims. When direct reclaims are prevented, the CPU
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3014) consumed by them is prevented as well. Depending on the workload, the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3015) result can cause aggregate CPU usage on the system to go up, down or
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3016) stay the same.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3017)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3018) More aggressive page replacement can reduce direct reclaims which
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3019) cause latency for tasks and decrease throughput when doing filesystem
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3020) IO through the pagecache. Direct reclaims are recorded using the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3021) allocstall counter in /proc/vmstat.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3022)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3023) The range of acceptible values are 1-16. Always start with lower
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3024) values in the 2-6 range. Higher values should be justified with
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3025) testing. If direct reclaims occur in spite of high values, the cost
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3026) of direct reclaims (in latency) that occur can be higher due to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3027) increased lock contention.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3028)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3029) onenand.bdry= [HW,MTD] Flex-OneNAND Boundary Configuration
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3030)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3031) Format: [die0_boundary][,die0_lock][,die1_boundary][,die1_lock]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3032)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3033) boundary - index of last SLC block on Flex-OneNAND.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3034) The remaining blocks are configured as MLC blocks.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3035) lock - Configure if Flex-OneNAND boundary should be locked.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3036) Once locked, the boundary cannot be changed.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3037) 1 indicates lock status, 0 indicates unlock status.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3038)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3039) mtdset= [ARM]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3040) ARM/S3C2412 JIVE boot control
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3041)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3042) See arch/arm/mach-s3c2412/mach-jive.c
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3043)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3044) mtouchusb.raw_coordinates=
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3045) [HW] Make the MicroTouch USB driver use raw coordinates
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3046) ('y', default) or cooked coordinates ('n')
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3047)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3048) mtrr_chunk_size=nn[KMG] [X86]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3049) used for mtrr cleanup. It is largest continuous chunk
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3050) that could hold holes aka. UC entries.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3051)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3052) mtrr_gran_size=nn[KMG] [X86]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3053) Used for mtrr cleanup. It is granularity of mtrr block.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3054) Default is 1.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3055) Large value could prevent small alignment from
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3056) using up MTRRs.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3057)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3058) mtrr_spare_reg_nr=n [X86]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3059) Format: <integer>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3060) Range: 0,7 : spare reg number
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3061) Default : 1
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3062) Used for mtrr cleanup. It is spare mtrr entries number.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3063) Set to 2 or more if your graphical card needs more.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3064)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3065) n2= [NET] SDL Inc. RISCom/N2 synchronous serial card
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3066)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3067) netdev= [NET] Network devices parameters
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3068) Format: <irq>,<io>,<mem_start>,<mem_end>,<name>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3069) Note that mem_start is often overloaded to mean
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3070) something different and driver-specific.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3071) This usage is only documented in each driver source
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3072) file if at all.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3073)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3074) nf_conntrack.acct=
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3075) [NETFILTER] Enable connection tracking flow accounting
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3076) 0 to disable accounting
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3077) 1 to enable accounting
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3078) Default value is 0.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3079)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3080) nfsaddrs= [NFS] Deprecated. Use ip= instead.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3081) See Documentation/admin-guide/nfs/nfsroot.rst.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3082)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3083) nfsroot= [NFS] nfs root filesystem for disk-less boxes.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3084) See Documentation/admin-guide/nfs/nfsroot.rst.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3085)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3086) nfsrootdebug [NFS] enable nfsroot debugging messages.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3087) See Documentation/admin-guide/nfs/nfsroot.rst.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3088)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3089) nfs.callback_nr_threads=
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3090) [NFSv4] set the total number of threads that the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3091) NFS client will assign to service NFSv4 callback
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3092) requests.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3093)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3094) nfs.callback_tcpport=
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3095) [NFS] set the TCP port on which the NFSv4 callback
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3096) channel should listen.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3097)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3098) nfs.cache_getent=
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3099) [NFS] sets the pathname to the program which is used
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3100) to update the NFS client cache entries.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3101)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3102) nfs.cache_getent_timeout=
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3103) [NFS] sets the timeout after which an attempt to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3104) update a cache entry is deemed to have failed.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3105)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3106) nfs.idmap_cache_timeout=
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3107) [NFS] set the maximum lifetime for idmapper cache
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3108) entries.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3109)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3110) nfs.enable_ino64=
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3111) [NFS] enable 64-bit inode numbers.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3112) If zero, the NFS client will fake up a 32-bit inode
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3113) number for the readdir() and stat() syscalls instead
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3114) of returning the full 64-bit number.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3115) The default is to return 64-bit inode numbers.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3116)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3117) nfs.max_session_cb_slots=
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3118) [NFSv4.1] Sets the maximum number of session
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3119) slots the client will assign to the callback
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3120) channel. This determines the maximum number of
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3121) callbacks the client will process in parallel for
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3122) a particular server.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3123)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3124) nfs.max_session_slots=
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3125) [NFSv4.1] Sets the maximum number of session slots
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3126) the client will attempt to negotiate with the server.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3127) This limits the number of simultaneous RPC requests
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3128) that the client can send to the NFSv4.1 server.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3129) Note that there is little point in setting this
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3130) value higher than the max_tcp_slot_table_limit.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3131)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3132) nfs.nfs4_disable_idmapping=
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3133) [NFSv4] When set to the default of '1', this option
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3134) ensures that both the RPC level authentication
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3135) scheme and the NFS level operations agree to use
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3136) numeric uids/gids if the mount is using the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3137) 'sec=sys' security flavour. In effect it is
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3138) disabling idmapping, which can make migration from
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3139) legacy NFSv2/v3 systems to NFSv4 easier.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3140) Servers that do not support this mode of operation
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3141) will be autodetected by the client, and it will fall
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3142) back to using the idmapper.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3143) To turn off this behaviour, set the value to '0'.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3144) nfs.nfs4_unique_id=
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3145) [NFS4] Specify an additional fixed unique ident-
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3146) ification string that NFSv4 clients can insert into
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3147) their nfs_client_id4 string. This is typically a
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3148) UUID that is generated at system install time.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3149)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3150) nfs.send_implementation_id =
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3151) [NFSv4.1] Send client implementation identification
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3152) information in exchange_id requests.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3153) If zero, no implementation identification information
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3154) will be sent.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3155) The default is to send the implementation identification
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3156) information.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3157)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3158) nfs.recover_lost_locks =
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3159) [NFSv4] Attempt to recover locks that were lost due
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3160) to a lease timeout on the server. Please note that
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3161) doing this risks data corruption, since there are
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3162) no guarantees that the file will remain unchanged
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3163) after the locks are lost.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3164) If you want to enable the kernel legacy behaviour of
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3165) attempting to recover these locks, then set this
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3166) parameter to '1'.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3167) The default parameter value of '0' causes the kernel
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3168) not to attempt recovery of lost locks.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3169)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3170) nfs4.layoutstats_timer =
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3171) [NFSv4.2] Change the rate at which the kernel sends
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3172) layoutstats to the pNFS metadata server.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3173)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3174) Setting this to value to 0 causes the kernel to use
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3175) whatever value is the default set by the layout
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3176) driver. A non-zero value sets the minimum interval
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3177) in seconds between layoutstats transmissions.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3178)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3179) nfsd.nfs4_disable_idmapping=
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3180) [NFSv4] When set to the default of '1', the NFSv4
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3181) server will return only numeric uids and gids to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3182) clients using auth_sys, and will accept numeric uids
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3183) and gids from such clients. This is intended to ease
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3184) migration from NFSv2/v3.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3185)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3186) nmi_backtrace.backtrace_idle [KNL]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3187) Dump stacks even of idle CPUs in response to an
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3188) NMI stack-backtrace request.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3189)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3190) nmi_debug= [KNL,SH] Specify one or more actions to take
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3191) when a NMI is triggered.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3192) Format: [state][,regs][,debounce][,die]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3193)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3194) nmi_watchdog= [KNL,BUGS=X86] Debugging features for SMP kernels
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3195) Format: [panic,][nopanic,][num]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3196) Valid num: 0 or 1
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3197) 0 - turn hardlockup detector in nmi_watchdog off
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3198) 1 - turn hardlockup detector in nmi_watchdog on
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3199) When panic is specified, panic when an NMI watchdog
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3200) timeout occurs (or 'nopanic' to not panic on an NMI
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3201) watchdog, if CONFIG_BOOTPARAM_HARDLOCKUP_PANIC is set)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3202) To disable both hard and soft lockup detectors,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3203) please see 'nowatchdog'.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3204) This is useful when you use a panic=... timeout and
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3205) need the box quickly up again.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3206)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3207) These settings can be accessed at runtime via
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3208) the nmi_watchdog and hardlockup_panic sysctls.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3209)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3210) netpoll.carrier_timeout=
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3211) [NET] Specifies amount of time (in seconds) that
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3212) netpoll should wait for a carrier. By default netpoll
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3213) waits 4 seconds.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3214)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3215) no387 [BUGS=X86-32] Tells the kernel to use the 387 maths
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3216) emulation library even if a 387 maths coprocessor
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3217) is present.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3218)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3219) no5lvl [X86-64] Disable 5-level paging mode. Forces
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3220) kernel to use 4-level paging instead.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3221)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3222) nofsgsbase [X86] Disables FSGSBASE instructions.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3223)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3224) no_console_suspend
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3225) [HW] Never suspend the console
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3226) Disable suspending of consoles during suspend and
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3227) hibernate operations. Once disabled, debugging
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3228) messages can reach various consoles while the rest
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3229) of the system is being put to sleep (ie, while
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3230) debugging driver suspend/resume hooks). This may
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3231) not work reliably with all consoles, but is known
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3232) to work with serial and VGA consoles.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3233) To facilitate more flexible debugging, we also add
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3234) console_suspend, a printk module parameter to control
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3235) it. Users could use console_suspend (usually
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3236) /sys/module/printk/parameters/console_suspend) to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3237) turn on/off it dynamically.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3238)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3239) novmcoredd [KNL,KDUMP]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3240) Disable device dump. Device dump allows drivers to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3241) append dump data to vmcore so you can collect driver
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3242) specified debug info. Drivers can append the data
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3243) without any limit and this data is stored in memory,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3244) so this may cause significant memory stress. Disabling
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3245) device dump can help save memory but the driver debug
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3246) data will be no longer available. This parameter
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3247) is only available when CONFIG_PROC_VMCORE_DEVICE_DUMP
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3248) is set.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3249)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3250) noaliencache [MM, NUMA, SLAB] Disables the allocation of alien
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3251) caches in the slab allocator. Saves per-node memory,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3252) but will impact performance.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3253)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3254) noalign [KNL,ARM]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3255)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3256) noaltinstr [S390] Disables alternative instructions patching
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3257) (CPU alternatives feature).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3258)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3259) noapic [SMP,APIC] Tells the kernel to not make use of any
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3260) IOAPICs that may be present in the system.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3261)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3262) noautogroup Disable scheduler automatic task group creation.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3263)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3264) nobats [PPC] Do not use BATs for mapping kernel lowmem
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3265) on "Classic" PPC cores.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3266)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3267) nocache [ARM]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3268)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3269) noclflush [BUGS=X86] Don't use the CLFLUSH instruction
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3270)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3271) nodelayacct [KNL] Disable per-task delay accounting
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3272)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3273) nodsp [SH] Disable hardware DSP at boot time.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3274)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3275) noefi Disable EFI runtime services support.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3276)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3277) no_entry_flush [PPC] Don't flush the L1-D cache when entering the kernel.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3278)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3279) noexec [IA-64]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3280)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3281) noexec [X86]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3282) On X86-32 available only on PAE configured kernels.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3283) noexec=on: enable non-executable mappings (default)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3284) noexec=off: disable non-executable mappings
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3285)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3286) nosmap [X86,PPC]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3287) Disable SMAP (Supervisor Mode Access Prevention)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3288) even if it is supported by processor.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3289)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3290) nosmep [X86,PPC]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3291) Disable SMEP (Supervisor Mode Execution Prevention)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3292) even if it is supported by processor.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3293)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3294) noexec32 [X86-64]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3295) This affects only 32-bit executables.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3296) noexec32=on: enable non-executable mappings (default)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3297) read doesn't imply executable mappings
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3298) noexec32=off: disable non-executable mappings
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3299) read implies executable mappings
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3300)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3301) nofpu [MIPS,SH] Disable hardware FPU at boot time.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3302)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3303) nofxsr [BUGS=X86-32] Disables x86 floating point extended
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3304) register save and restore. The kernel will only save
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3305) legacy floating-point registers on task switch.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3306)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3307) nohugeiomap [KNL,X86,PPC,ARM64] Disable kernel huge I/O mappings.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3308)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3309) nosmt [KNL,S390] Disable symmetric multithreading (SMT).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3310) Equivalent to smt=1.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3311)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3312) [KNL,X86] Disable symmetric multithreading (SMT).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3313) nosmt=force: Force disable SMT, cannot be undone
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3314) via the sysfs control file.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3315)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3316) nospectre_v1 [X86,PPC] Disable mitigations for Spectre Variant 1
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3317) (bounds check bypass). With this option data leaks are
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3318) possible in the system.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3319)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3320) nospectre_v2 [X86,PPC_FSL_BOOK3E,ARM64] Disable all mitigations for
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3321) the Spectre variant 2 (indirect branch prediction)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3322) vulnerability. System may allow data leaks with this
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3323) option.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3324)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3325) nospec_store_bypass_disable
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3326) [HW] Disable all mitigations for the Speculative Store Bypass vulnerability
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3327)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3328) no_uaccess_flush
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3329) [PPC] Don't flush the L1-D cache after accessing user data.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3330)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3331) noxsave [BUGS=X86] Disables x86 extended register state save
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3332) and restore using xsave. The kernel will fallback to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3333) enabling legacy floating-point and sse state.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3334)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3335) noxsaveopt [X86] Disables xsaveopt used in saving x86 extended
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3336) register states. The kernel will fall back to use
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3337) xsave to save the states. By using this parameter,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3338) performance of saving the states is degraded because
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3339) xsave doesn't support modified optimization while
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3340) xsaveopt supports it on xsaveopt enabled systems.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3341)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3342) noxsaves [X86] Disables xsaves and xrstors used in saving and
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3343) restoring x86 extended register state in compacted
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3344) form of xsave area. The kernel will fall back to use
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3345) xsaveopt and xrstor to save and restore the states
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3346) in standard form of xsave area. By using this
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3347) parameter, xsave area per process might occupy more
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3348) memory on xsaves enabled systems.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3349)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3350) nohlt [BUGS=ARM,SH] Tells the kernel that the sleep(SH) or
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3351) wfi(ARM) instruction doesn't work correctly and not to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3352) use it. This is also useful when using JTAG debugger.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3353)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3354) no_file_caps Tells the kernel not to honor file capabilities. The
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3355) only way then for a file to be executed with privilege
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3356) is to be setuid root or executed by root.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3357)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3358) nohalt [IA-64] Tells the kernel not to use the power saving
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3359) function PAL_HALT_LIGHT when idle. This increases
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3360) power-consumption. On the positive side, it reduces
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3361) interrupt wake-up latency, which may improve performance
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3362) in certain environments such as networked servers or
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3363) real-time systems.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3364)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3365) no_hash_pointers
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3366) Force pointers printed to the console or buffers to be
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3367) unhashed. By default, when a pointer is printed via %p
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3368) format string, that pointer is "hashed", i.e. obscured
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3369) by hashing the pointer value. This is a security feature
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3370) that hides actual kernel addresses from unprivileged
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3371) users, but it also makes debugging the kernel more
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3372) difficult since unequal pointers can no longer be
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3373) compared. However, if this command-line option is
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3374) specified, then all normal pointers will have their true
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3375) value printed. Pointers printed via %pK may still be
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3376) hashed. This option should only be specified when
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3377) debugging the kernel. Please do not use on production
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3378) kernels.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3379)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3380) nohibernate [HIBERNATION] Disable hibernation and resume.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3381)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3382) nohz= [KNL] Boottime enable/disable dynamic ticks
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3383) Valid arguments: on, off
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3384) Default: on
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3385)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3386) nohz_full= [KNL,BOOT,SMP,ISOL]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3387) The argument is a cpu list, as described above.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3388) In kernels built with CONFIG_NO_HZ_FULL=y, set
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3389) the specified list of CPUs whose tick will be stopped
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3390) whenever possible. The boot CPU will be forced outside
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3391) the range to maintain the timekeeping. Any CPUs
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3392) in this list will have their RCU callbacks offloaded,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3393) just as if they had also been called out in the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3394) rcu_nocbs= boot parameter.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3395)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3396) noiotrap [SH] Disables trapped I/O port accesses.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3397)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3398) noirqdebug [X86-32] Disables the code which attempts to detect and
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3399) disable unhandled interrupt sources.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3400)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3401) no_timer_check [X86,APIC] Disables the code which tests for
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3402) broken timer IRQ sources.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3403)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3404) noisapnp [ISAPNP] Disables ISA PnP code.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3405)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3406) noinitrd [RAM] Tells the kernel not to load any configured
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3407) initial RAM disk.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3408)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3409) nointremap [X86-64, Intel-IOMMU] Do not enable interrupt
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3410) remapping.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3411) [Deprecated - use intremap=off]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3412)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3413) nointroute [IA-64]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3414)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3415) noinvpcid [X86] Disable the INVPCID cpu feature.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3416)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3417) nojitter [IA-64] Disables jitter checking for ITC timers.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3418)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3419) no-kvmclock [X86,KVM] Disable paravirtualized KVM clock driver
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3420)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3421) no-kvmapf [X86,KVM] Disable paravirtualized asynchronous page
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3422) fault handling.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3423)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3424) no-vmw-sched-clock
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3425) [X86,PV_OPS] Disable paravirtualized VMware scheduler
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3426) clock and use the default one.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3427)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3428) no-steal-acc [X86,PV_OPS,ARM64] Disable paravirtualized steal time
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3429) accounting. steal time is computed, but won't
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3430) influence scheduler behaviour
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3431)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3432) nolapic [X86-32,APIC] Do not enable or use the local APIC.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3433)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3434) nolapic_timer [X86-32,APIC] Do not use the local APIC timer.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3435)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3436) noltlbs [PPC] Do not use large page/tlb entries for kernel
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3437) lowmem mapping on PPC40x and PPC8xx
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3438)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3439) nomca [IA-64] Disable machine check abort handling
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3440)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3441) nomce [X86-32] Disable Machine Check Exception
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3442)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3443) nomfgpt [X86-32] Disable Multi-Function General Purpose
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3444) Timer usage (for AMD Geode machines).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3445)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3446) nonmi_ipi [X86] Disable using NMI IPIs during panic/reboot to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3447) shutdown the other cpus. Instead use the REBOOT_VECTOR
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3448) irq.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3449)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3450) nomodule Disable module load
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3451)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3452) nopat [X86] Disable PAT (page attribute table extension of
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3453) pagetables) support.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3454)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3455) nopcid [X86-64] Disable the PCID cpu feature.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3456)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3457) norandmaps Don't use address space randomization. Equivalent to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3458) echo 0 > /proc/sys/kernel/randomize_va_space
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3459)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3460) noreplace-smp [X86-32,SMP] Don't replace SMP instructions
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3461) with UP alternatives
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3462)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3463) nordrand [X86] Disable kernel use of the RDRAND and
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3464) RDSEED instructions even if they are supported
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3465) by the processor. RDRAND and RDSEED are still
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3466) available to user space applications.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3467)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3468) noresume [SWSUSP] Disables resume and restores original swap
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3469) space.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3470)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3471) no-scroll [VGA] Disables scrollback.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3472) This is required for the Braillex ib80-piezo Braille
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3473) reader made by F.H. Papenmeier (Germany).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3474)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3475) nosbagart [IA-64]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3476)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3477) nosep [BUGS=X86-32] Disables x86 SYSENTER/SYSEXIT support.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3478)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3479) nosmp [SMP] Tells an SMP kernel to act as a UP kernel,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3480) and disable the IO APIC. legacy for "maxcpus=0".
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3481)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3482) nosoftlockup [KNL] Disable the soft-lockup detector.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3483)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3484) nosync [HW,M68K] Disables sync negotiation for all devices.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3485)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3486) nowatchdog [KNL] Disable both lockup detectors, i.e.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3487) soft-lockup and NMI watchdog (hard-lockup).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3488)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3489) nowb [ARM]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3490)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3491) nox2apic [X86-64,APIC] Do not enable x2APIC mode.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3492)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3493) cpu0_hotplug [X86] Turn on CPU0 hotplug feature when
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3494) CONFIG_BOOTPARAM_HOTPLUG_CPU0 is off.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3495) Some features depend on CPU0. Known dependencies are:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3496) 1. Resume from suspend/hibernate depends on CPU0.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3497) Suspend/hibernate will fail if CPU0 is offline and you
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3498) need to online CPU0 before suspend/hibernate.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3499) 2. PIC interrupts also depend on CPU0. CPU0 can't be
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3500) removed if a PIC interrupt is detected.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3501) It's said poweroff/reboot may depend on CPU0 on some
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3502) machines although I haven't seen such issues so far
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3503) after CPU0 is offline on a few tested machines.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3504) If the dependencies are under your control, you can
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3505) turn on cpu0_hotplug.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3506)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3507) nps_mtm_hs_ctr= [KNL,ARC]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3508) This parameter sets the maximum duration, in
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3509) cycles, each HW thread of the CTOP can run
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3510) without interruptions, before HW switches it.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3511) The actual maximum duration is 16 times this
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3512) parameter's value.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3513) Format: integer between 1 and 255
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3514) Default: 255
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3515)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3516) nptcg= [IA-64] Override max number of concurrent global TLB
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3517) purges which is reported from either PAL_VM_SUMMARY or
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3518) SAL PALO.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3519)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3520) nr_cpus= [SMP] Maximum number of processors that an SMP kernel
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3521) could support. nr_cpus=n : n >= 1 limits the kernel to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3522) support 'n' processors. It could be larger than the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3523) number of already plugged CPU during bootup, later in
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3524) runtime you can physically add extra cpu until it reaches
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3525) n. So during boot up some boot time memory for per-cpu
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3526) variables need be pre-allocated for later physical cpu
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3527) hot plugging.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3528)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3529) nr_uarts= [SERIAL] maximum number of UARTs to be registered.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3530)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3531) numa_balancing= [KNL,X86] Enable or disable automatic NUMA balancing.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3532) Allowed values are enable and disable
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3533)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3534) numa_zonelist_order= [KNL, BOOT] Select zonelist order for NUMA.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3535) 'node', 'default' can be specified
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3536) This can be set from sysctl after boot.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3537) See Documentation/admin-guide/sysctl/vm.rst for details.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3538)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3539) ohci1394_dma=early [HW] enable debugging via the ohci1394 driver.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3540) See Documentation/core-api/debugging-via-ohci1394.rst for more
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3541) info.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3542)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3543) olpc_ec_timeout= [OLPC] ms delay when issuing EC commands
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3544) Rather than timing out after 20 ms if an EC
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3545) command is not properly ACKed, override the length
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3546) of the timeout. We have interrupts disabled while
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3547) waiting for the ACK, so if this is set too high
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3548) interrupts *may* be lost!
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3549)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3550) omap_mux= [OMAP] Override bootloader pin multiplexing.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3551) Format: <mux_mode0.mode_name=value>...
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3552) For example, to override I2C bus2:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3553) omap_mux=i2c2_scl.i2c2_scl=0x100,i2c2_sda.i2c2_sda=0x100
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3554)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3555) oprofile.timer= [HW]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3556) Use timer interrupt instead of performance counters
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3557)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3558) oprofile.cpu_type= Force an oprofile cpu type
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3559) This might be useful if you have an older oprofile
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3560) userland or if you want common events.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3561) Format: { arch_perfmon }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3562) arch_perfmon: [X86] Force use of architectural
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3563) perfmon on Intel CPUs instead of the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3564) CPU specific event set.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3565) timer: [X86] Force use of architectural NMI
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3566) timer mode (see also oprofile.timer
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3567) for generic hr timer mode)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3568)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3569) oops=panic Always panic on oopses. Default is to just kill the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3570) process, but there is a small probability of
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3571) deadlocking the machine.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3572) This will also cause panics on machine check exceptions.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3573) Useful together with panic=30 to trigger a reboot.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3574)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3575) page_alloc.shuffle=
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3576) [KNL] Boolean flag to control whether the page allocator
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3577) should randomize its free lists. The randomization may
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3578) be automatically enabled if the kernel detects it is
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3579) running on a platform with a direct-mapped memory-side
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3580) cache, and this parameter can be used to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3581) override/disable that behavior. The state of the flag
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3582) can be read from sysfs at:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3583) /sys/module/page_alloc/parameters/shuffle.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3584)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3585) page_owner= [KNL] Boot-time page_owner enabling option.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3586) Storage of the information about who allocated
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3587) each page is disabled in default. With this switch,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3588) we can turn it on.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3589) on: enable the feature
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3590)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3591) page_poison= [KNL] Boot-time parameter changing the state of
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3592) poisoning on the buddy allocator, available with
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3593) CONFIG_PAGE_POISONING=y.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3594) off: turn off poisoning (default)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3595) on: turn on poisoning
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3596)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3597) panic= [KNL] Kernel behaviour on panic: delay <timeout>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3598) timeout > 0: seconds before rebooting
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3599) timeout = 0: wait forever
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3600) timeout < 0: reboot immediately
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3601) Format: <timeout>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3602)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3603) panic_print= Bitmask for printing system info when panic happens.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3604) User can chose combination of the following bits:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3605) bit 0: print all tasks info
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3606) bit 1: print system memory info
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3607) bit 2: print timer info
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3608) bit 3: print locks info if CONFIG_LOCKDEP is on
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3609) bit 4: print ftrace buffer
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3610) bit 5: print all printk messages in buffer
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3611)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3612) panic_on_taint= Bitmask for conditionally calling panic() in add_taint()
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3613) Format: <hex>[,nousertaint]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3614) Hexadecimal bitmask representing the set of TAINT flags
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3615) that will cause the kernel to panic when add_taint() is
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3616) called with any of the flags in this set.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3617) The optional switch "nousertaint" can be utilized to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3618) prevent userspace forced crashes by writing to sysctl
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3619) /proc/sys/kernel/tainted any flagset matching with the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3620) bitmask set on panic_on_taint.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3621) See Documentation/admin-guide/tainted-kernels.rst for
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3622) extra details on the taint flags that users can pick
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3623) to compose the bitmask to assign to panic_on_taint.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3624)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3625) panic_on_warn panic() instead of WARN(). Useful to cause kdump
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3626) on a WARN().
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3627)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3628) pelt= [KNL] Boot-time parameter changing the PELT half life in ms
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3629) Format: <int>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3630) 32: Set the half life to 32ms
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3631) 8: Set the half life to 8ms
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3632) default: 32
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3633)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3634) crash_kexec_post_notifiers
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3635) Run kdump after running panic-notifiers and dumping
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3636) kmsg. This only for the users who doubt kdump always
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3637) succeeds in any situation.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3638) Note that this also increases risks of kdump failure,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3639) because some panic notifiers can make the crashed
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3640) kernel more unstable.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3641)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3642) parkbd.port= [HW] Parallel port number the keyboard adapter is
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3643) connected to, default is 0.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3644) Format: <parport#>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3645) parkbd.mode= [HW] Parallel port keyboard adapter mode of operation,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3646) 0 for XT, 1 for AT (default is AT).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3647) Format: <mode>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3648)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3649) parport= [HW,PPT] Specify parallel ports. 0 disables.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3650) Format: { 0 | auto | 0xBBB[,IRQ[,DMA]] }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3651) Use 'auto' to force the driver to use any
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3652) IRQ/DMA settings detected (the default is to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3653) ignore detected IRQ/DMA settings because of
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3654) possible conflicts). You can specify the base
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3655) address, IRQ, and DMA settings; IRQ and DMA
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3656) should be numbers, or 'auto' (for using detected
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3657) settings on that particular port), or 'nofifo'
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3658) (to avoid using a FIFO even if it is detected).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3659) Parallel ports are assigned in the order they
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3660) are specified on the command line, starting
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3661) with parport0.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3662)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3663) parport_init_mode= [HW,PPT]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3664) Configure VIA parallel port to operate in
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3665) a specific mode. This is necessary on Pegasos
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3666) computer where firmware has no options for setting
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3667) up parallel port mode and sets it to spp.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3668) Currently this function knows 686a and 8231 chips.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3669) Format: [spp|ps2|epp|ecp|ecpepp]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3670)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3671) pause_on_oops=
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3672) Halt all CPUs after the first oops has been printed for
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3673) the specified number of seconds. This is to be used if
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3674) your oopses keep scrolling off the screen.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3675)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3676) pcbit= [HW,ISDN]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3677)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3678) pcd. [PARIDE]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3679) See header of drivers/block/paride/pcd.c.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3680) See also Documentation/admin-guide/blockdev/paride.rst.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3681)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3682) pci=option[,option...] [PCI] various PCI subsystem options.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3683)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3684) Some options herein operate on a specific device
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3685) or a set of devices (<pci_dev>). These are
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3686) specified in one of the following formats:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3687)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3688) [<domain>:]<bus>:<dev>.<func>[/<dev>.<func>]*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3689) pci:<vendor>:<device>[:<subvendor>:<subdevice>]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3690)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3691) Note: the first format specifies a PCI
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3692) bus/device/function address which may change
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3693) if new hardware is inserted, if motherboard
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3694) firmware changes, or due to changes caused
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3695) by other kernel parameters. If the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3696) domain is left unspecified, it is
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3697) taken to be zero. Optionally, a path
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3698) to a device through multiple device/function
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3699) addresses can be specified after the base
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3700) address (this is more robust against
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3701) renumbering issues). The second format
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3702) selects devices using IDs from the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3703) configuration space which may match multiple
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3704) devices in the system.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3705)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3706) earlydump dump PCI config space before the kernel
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3707) changes anything
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3708) off [X86] don't probe for the PCI bus
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3709) bios [X86-32] force use of PCI BIOS, don't access
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3710) the hardware directly. Use this if your machine
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3711) has a non-standard PCI host bridge.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3712) nobios [X86-32] disallow use of PCI BIOS, only direct
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3713) hardware access methods are allowed. Use this
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3714) if you experience crashes upon bootup and you
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3715) suspect they are caused by the BIOS.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3716) conf1 [X86] Force use of PCI Configuration Access
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3717) Mechanism 1 (config address in IO port 0xCF8,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3718) data in IO port 0xCFC, both 32-bit).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3719) conf2 [X86] Force use of PCI Configuration Access
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3720) Mechanism 2 (IO port 0xCF8 is an 8-bit port for
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3721) the function, IO port 0xCFA, also 8-bit, sets
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3722) bus number. The config space is then accessed
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3723) through ports 0xC000-0xCFFF).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3724) See http://wiki.osdev.org/PCI for more info
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3725) on the configuration access mechanisms.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3726) noaer [PCIE] If the PCIEAER kernel config parameter is
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3727) enabled, this kernel boot option can be used to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3728) disable the use of PCIE advanced error reporting.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3729) nodomains [PCI] Disable support for multiple PCI
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3730) root domains (aka PCI segments, in ACPI-speak).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3731) nommconf [X86] Disable use of MMCONFIG for PCI
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3732) Configuration
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3733) check_enable_amd_mmconf [X86] check for and enable
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3734) properly configured MMIO access to PCI
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3735) config space on AMD family 10h CPU
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3736) nomsi [MSI] If the PCI_MSI kernel config parameter is
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3737) enabled, this kernel boot option can be used to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3738) disable the use of MSI interrupts system-wide.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3739) noioapicquirk [APIC] Disable all boot interrupt quirks.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3740) Safety option to keep boot IRQs enabled. This
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3741) should never be necessary.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3742) ioapicreroute [APIC] Enable rerouting of boot IRQs to the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3743) primary IO-APIC for bridges that cannot disable
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3744) boot IRQs. This fixes a source of spurious IRQs
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3745) when the system masks IRQs.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3746) noioapicreroute [APIC] Disable workaround that uses the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3747) boot IRQ equivalent of an IRQ that connects to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3748) a chipset where boot IRQs cannot be disabled.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3749) The opposite of ioapicreroute.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3750) biosirq [X86-32] Use PCI BIOS calls to get the interrupt
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3751) routing table. These calls are known to be buggy
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3752) on several machines and they hang the machine
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3753) when used, but on other computers it's the only
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3754) way to get the interrupt routing table. Try
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3755) this option if the kernel is unable to allocate
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3756) IRQs or discover secondary PCI buses on your
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3757) motherboard.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3758) rom [X86] Assign address space to expansion ROMs.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3759) Use with caution as certain devices share
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3760) address decoders between ROMs and other
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3761) resources.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3762) norom [X86] Do not assign address space to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3763) expansion ROMs that do not already have
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3764) BIOS assigned address ranges.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3765) nobar [X86] Do not assign address space to the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3766) BARs that weren't assigned by the BIOS.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3767) irqmask=0xMMMM [X86] Set a bit mask of IRQs allowed to be
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3768) assigned automatically to PCI devices. You can
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3769) make the kernel exclude IRQs of your ISA cards
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3770) this way.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3771) pirqaddr=0xAAAAA [X86] Specify the physical address
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3772) of the PIRQ table (normally generated
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3773) by the BIOS) if it is outside the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3774) F0000h-100000h range.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3775) lastbus=N [X86] Scan all buses thru bus #N. Can be
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3776) useful if the kernel is unable to find your
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3777) secondary buses and you want to tell it
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3778) explicitly which ones they are.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3779) assign-busses [X86] Always assign all PCI bus
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3780) numbers ourselves, overriding
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3781) whatever the firmware may have done.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3782) usepirqmask [X86] Honor the possible IRQ mask stored
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3783) in the BIOS $PIR table. This is needed on
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3784) some systems with broken BIOSes, notably
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3785) some HP Pavilion N5400 and Omnibook XE3
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3786) notebooks. This will have no effect if ACPI
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3787) IRQ routing is enabled.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3788) noacpi [X86] Do not use ACPI for IRQ routing
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3789) or for PCI scanning.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3790) use_crs [X86] Use PCI host bridge window information
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3791) from ACPI. On BIOSes from 2008 or later, this
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3792) is enabled by default. If you need to use this,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3793) please report a bug.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3794) nocrs [X86] Ignore PCI host bridge windows from ACPI.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3795) If you need to use this, please report a bug.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3796) routeirq Do IRQ routing for all PCI devices.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3797) This is normally done in pci_enable_device(),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3798) so this option is a temporary workaround
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3799) for broken drivers that don't call it.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3800) skip_isa_align [X86] do not align io start addr, so can
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3801) handle more pci cards
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3802) noearly [X86] Don't do any early type 1 scanning.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3803) This might help on some broken boards which
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3804) machine check when some devices' config space
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3805) is read. But various workarounds are disabled
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3806) and some IOMMU drivers will not work.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3807) bfsort Sort PCI devices into breadth-first order.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3808) This sorting is done to get a device
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3809) order compatible with older (<= 2.4) kernels.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3810) nobfsort Don't sort PCI devices into breadth-first order.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3811) pcie_bus_tune_off Disable PCIe MPS (Max Payload Size)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3812) tuning and use the BIOS-configured MPS defaults.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3813) pcie_bus_safe Set every device's MPS to the largest value
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3814) supported by all devices below the root complex.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3815) pcie_bus_perf Set device MPS to the largest allowable MPS
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3816) based on its parent bus. Also set MRRS (Max
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3817) Read Request Size) to the largest supported
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3818) value (no larger than the MPS that the device
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3819) or bus can support) for best performance.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3820) pcie_bus_peer2peer Set every device's MPS to 128B, which
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3821) every device is guaranteed to support. This
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3822) configuration allows peer-to-peer DMA between
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3823) any pair of devices, possibly at the cost of
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3824) reduced performance. This also guarantees
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3825) that hot-added devices will work.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3826) cbiosize=nn[KMG] The fixed amount of bus space which is
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3827) reserved for the CardBus bridge's IO window.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3828) The default value is 256 bytes.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3829) cbmemsize=nn[KMG] The fixed amount of bus space which is
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3830) reserved for the CardBus bridge's memory
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3831) window. The default value is 64 megabytes.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3832) resource_alignment=
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3833) Format:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3834) [<order of align>@]<pci_dev>[; ...]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3835) Specifies alignment and device to reassign
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3836) aligned memory resources. How to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3837) specify the device is described above.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3838) If <order of align> is not specified,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3839) PAGE_SIZE is used as alignment.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3840) A PCI-PCI bridge can be specified if resource
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3841) windows need to be expanded.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3842) To specify the alignment for several
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3843) instances of a device, the PCI vendor,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3844) device, subvendor, and subdevice may be
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3845) specified, e.g., 12@pci:8086:9c22:103c:198f
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3846) for 4096-byte alignment.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3847) ecrc= Enable/disable PCIe ECRC (transaction layer
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3848) end-to-end CRC checking).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3849) bios: Use BIOS/firmware settings. This is the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3850) the default.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3851) off: Turn ECRC off
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3852) on: Turn ECRC on.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3853) hpiosize=nn[KMG] The fixed amount of bus space which is
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3854) reserved for hotplug bridge's IO window.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3855) Default size is 256 bytes.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3856) hpmmiosize=nn[KMG] The fixed amount of bus space which is
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3857) reserved for hotplug bridge's MMIO window.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3858) Default size is 2 megabytes.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3859) hpmmioprefsize=nn[KMG] The fixed amount of bus space which is
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3860) reserved for hotplug bridge's MMIO_PREF window.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3861) Default size is 2 megabytes.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3862) hpmemsize=nn[KMG] The fixed amount of bus space which is
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3863) reserved for hotplug bridge's MMIO and
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3864) MMIO_PREF window.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3865) Default size is 2 megabytes.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3866) hpbussize=nn The minimum amount of additional bus numbers
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3867) reserved for buses below a hotplug bridge.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3868) Default is 1.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3869) realloc= Enable/disable reallocating PCI bridge resources
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3870) if allocations done by BIOS are too small to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3871) accommodate resources required by all child
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3872) devices.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3873) off: Turn realloc off
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3874) on: Turn realloc on
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3875) realloc same as realloc=on
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3876) noari do not use PCIe ARI.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3877) noats [PCIE, Intel-IOMMU, AMD-IOMMU]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3878) do not use PCIe ATS (and IOMMU device IOTLB).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3879) pcie_scan_all Scan all possible PCIe devices. Otherwise we
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3880) only look for one device below a PCIe downstream
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3881) port.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3882) big_root_window Try to add a big 64bit memory window to the PCIe
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3883) root complex on AMD CPUs. Some GFX hardware
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3884) can resize a BAR to allow access to all VRAM.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3885) Adding the window is slightly risky (it may
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3886) conflict with unreported devices), so this
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3887) taints the kernel.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3888) disable_acs_redir=<pci_dev>[; ...]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3889) Specify one or more PCI devices (in the format
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3890) specified above) separated by semicolons.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3891) Each device specified will have the PCI ACS
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3892) redirect capabilities forced off which will
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3893) allow P2P traffic between devices through
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3894) bridges without forcing it upstream. Note:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3895) this removes isolation between devices and
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3896) may put more devices in an IOMMU group.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3897) force_floating [S390] Force usage of floating interrupts.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3898) nomio [S390] Do not use MIO instructions.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3899) norid [S390] ignore the RID field and force use of
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3900) one PCI domain per PCI function
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3901)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3902) pcie_aspm= [PCIE] Forcibly enable or disable PCIe Active State Power
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3903) Management.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3904) off Disable ASPM.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3905) force Enable ASPM even on devices that claim not to support it.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3906) WARNING: Forcing ASPM on may cause system lockups.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3907)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3908) pcie_ports= [PCIE] PCIe port services handling:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3909) native Use native PCIe services (PME, AER, DPC, PCIe hotplug)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3910) even if the platform doesn't give the OS permission to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3911) use them. This may cause conflicts if the platform
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3912) also tries to use these services.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3913) dpc-native Use native PCIe service for DPC only. May
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3914) cause conflicts if firmware uses AER or DPC.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3915) compat Disable native PCIe services (PME, AER, DPC, PCIe
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3916) hotplug).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3917)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3918) pcie_port_pm= [PCIE] PCIe port power management handling:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3919) off Disable power management of all PCIe ports
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3920) force Forcibly enable power management of all PCIe ports
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3921)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3922) pcie_pme= [PCIE,PM] Native PCIe PME signaling options:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3923) nomsi Do not use MSI for native PCIe PME signaling (this makes
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3924) all PCIe root ports use INTx for all services).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3925)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3926) pcmv= [HW,PCMCIA] BadgePAD 4
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3927)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3928) pd_ignore_unused
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3929) [PM]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3930) Keep all power-domains already enabled by bootloader on,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3931) even if no driver has claimed them. This is useful
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3932) for debug and development, but should not be
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3933) needed on a platform with proper driver support.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3934)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3935) pd. [PARIDE]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3936) See Documentation/admin-guide/blockdev/paride.rst.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3937)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3938) pdcchassis= [PARISC,HW] Disable/Enable PDC Chassis Status codes at
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3939) boot time.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3940) Format: { 0 | 1 }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3941) See arch/parisc/kernel/pdc_chassis.c
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3942)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3943) percpu_alloc= Select which percpu first chunk allocator to use.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3944) Currently supported values are "embed" and "page".
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3945) Archs may support subset or none of the selections.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3946) See comments in mm/percpu.c for details on each
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3947) allocator. This parameter is primarily for debugging
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3948) and performance comparison.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3949)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3950) pf. [PARIDE]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3951) See Documentation/admin-guide/blockdev/paride.rst.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3952)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3953) pg. [PARIDE]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3954) See Documentation/admin-guide/blockdev/paride.rst.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3955)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3956) pirq= [SMP,APIC] Manual mp-table setup
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3957) See Documentation/x86/i386/IO-APIC.rst.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3958)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3959) plip= [PPT,NET] Parallel port network link
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3960) Format: { parport<nr> | timid | 0 }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3961) See also Documentation/admin-guide/parport.rst.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3962)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3963) pmtmr= [X86] Manual setup of pmtmr I/O Port.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3964) Override pmtimer IOPort with a hex value.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3965) e.g. pmtmr=0x508
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3966)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3967) pm_debug_messages [SUSPEND,KNL]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3968) Enable suspend/resume debug messages during boot up.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3969)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3970) pnp.debug=1 [PNP]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3971) Enable PNP debug messages (depends on the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3972) CONFIG_PNP_DEBUG_MESSAGES option). Change at run-time
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3973) via /sys/module/pnp/parameters/debug. We always show
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3974) current resource usage; turning this on also shows
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3975) possible settings and some assignment information.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3976)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3977) pnpacpi= [ACPI]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3978) { off }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3979)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3980) pnpbios= [ISAPNP]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3981) { on | off | curr | res | no-curr | no-res }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3982)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3983) pnp_reserve_irq=
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3984) [ISAPNP] Exclude IRQs for the autoconfiguration
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3985)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3986) pnp_reserve_dma=
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3987) [ISAPNP] Exclude DMAs for the autoconfiguration
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3988)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3989) pnp_reserve_io= [ISAPNP] Exclude I/O ports for the autoconfiguration
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3990) Ranges are in pairs (I/O port base and size).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3991)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3992) pnp_reserve_mem=
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3993) [ISAPNP] Exclude memory regions for the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3994) autoconfiguration.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3995) Ranges are in pairs (memory base and size).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3996)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3997) ports= [IP_VS_FTP] IPVS ftp helper module
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3998) Default is 21.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3999) Up to 8 (IP_VS_APP_MAX_PORTS) ports
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4000) may be specified.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4001) Format: <port>,<port>....
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4002)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4003) powersave=off [PPC] This option disables power saving features.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4004) It specifically disables cpuidle and sets the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4005) platform machine description specific power_save
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4006) function to NULL. On Idle the CPU just reduces
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4007) execution priority.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4008)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4009) ppc_strict_facility_enable
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4010) [PPC] This option catches any kernel floating point,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4011) Altivec, VSX and SPE outside of regions specifically
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4012) allowed (eg kernel_enable_fpu()/kernel_disable_fpu()).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4013) There is some performance impact when enabling this.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4014)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4015) ppc_tm= [PPC]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4016) Format: {"off"}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4017) Disable Hardware Transactional Memory
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4018)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4019) print-fatal-signals=
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4020) [KNL] debug: print fatal signals
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4021)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4022) If enabled, warn about various signal handling
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4023) related application anomalies: too many signals,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4024) too many POSIX.1 timers, fatal signals causing a
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4025) coredump - etc.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4026)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4027) If you hit the warning due to signal overflow,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4028) you might want to try "ulimit -i unlimited".
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4029)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4030) default: off.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4031)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4032) printk.always_kmsg_dump=
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4033) Trigger kmsg_dump for cases other than kernel oops or
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4034) panics
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4035) Format: <bool> (1/Y/y=enable, 0/N/n=disable)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4036) default: disabled
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4037)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4038) printk.devkmsg={on,off,ratelimit}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4039) Control writing to /dev/kmsg.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4040) on - unlimited logging to /dev/kmsg from userspace
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4041) off - logging to /dev/kmsg disabled
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4042) ratelimit - ratelimit the logging
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4043) Default: ratelimit
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4044)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4045) printk.time= Show timing data prefixed to each printk message line
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4046) Format: <bool> (1/Y/y=enable, 0/N/n=disable)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4047)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4048) processor.max_cstate= [HW,ACPI]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4049) Limit processor to maximum C-state
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4050) max_cstate=9 overrides any DMI blacklist limit.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4051)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4052) processor.nocst [HW,ACPI]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4053) Ignore the _CST method to determine C-states,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4054) instead using the legacy FADT method
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4055)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4056) profile= [KNL] Enable kernel profiling via /proc/profile
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4057) Format: [<profiletype>,]<number>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4058) Param: <profiletype>: "schedule", "sleep", or "kvm"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4059) [defaults to kernel profiling]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4060) Param: "schedule" - profile schedule points.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4061) Param: "sleep" - profile D-state sleeping (millisecs).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4062) Requires CONFIG_SCHEDSTATS
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4063) Param: "kvm" - profile VM exits.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4064) Param: <number> - step/bucket size as a power of 2 for
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4065) statistical time based profiling.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4066)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4067) prompt_ramdisk= [RAM] [Deprecated]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4068)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4069) prot_virt= [S390] enable hosting protected virtual machines
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4070) isolated from the hypervisor (if hardware supports
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4071) that).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4072) Format: <bool>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4073)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4074) psi= [KNL] Enable or disable pressure stall information
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4075) tracking.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4076) Format: <bool>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4077)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4078) psmouse.proto= [HW,MOUSE] Highest PS2 mouse protocol extension to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4079) probe for; one of (bare|imps|exps|lifebook|any).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4080) psmouse.rate= [HW,MOUSE] Set desired mouse report rate, in reports
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4081) per second.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4082) psmouse.resetafter= [HW,MOUSE]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4083) Try to reset the device after so many bad packets
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4084) (0 = never).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4085) psmouse.resolution=
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4086) [HW,MOUSE] Set desired mouse resolution, in dpi.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4087) psmouse.smartscroll=
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4088) [HW,MOUSE] Controls Logitech smartscroll autorepeat.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4089) 0 = disabled, 1 = enabled (default).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4090)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4091) pstore.backend= Specify the name of the pstore backend to use
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4092)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4093) pt. [PARIDE]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4094) See Documentation/admin-guide/blockdev/paride.rst.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4095)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4096) pti= [X86-64] Control Page Table Isolation of user and
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4097) kernel address spaces. Disabling this feature
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4098) removes hardening, but improves performance of
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4099) system calls and interrupts.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4100)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4101) on - unconditionally enable
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4102) off - unconditionally disable
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4103) auto - kernel detects whether your CPU model is
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4104) vulnerable to issues that PTI mitigates
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4105)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4106) Not specifying this option is equivalent to pti=auto.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4107)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4108) nopti [X86-64]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4109) Equivalent to pti=off
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4110)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4111) pty.legacy_count=
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4112) [KNL] Number of legacy pty's. Overwrites compiled-in
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4113) default number.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4114)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4115) quiet [KNL] Disable most log messages
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4116)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4117) r128= [HW,DRM]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4118)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4119) raid= [HW,RAID]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4120) See Documentation/admin-guide/md.rst.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4121)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4122) ramdisk_size= [RAM] Sizes of RAM disks in kilobytes
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4123) See Documentation/admin-guide/blockdev/ramdisk.rst.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4124)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4125) ramdisk_start= [RAM] RAM disk image start address
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4126)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4127) random.trust_cpu={on,off}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4128) [KNL] Enable or disable trusting the use of the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4129) CPU's random number generator (if available) to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4130) fully seed the kernel's CRNG. Default is controlled
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4131) by CONFIG_RANDOM_TRUST_CPU.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4132)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4133) ras=option[,option,...] [KNL] RAS-specific options
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4134)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4135) cec_disable [X86]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4136) Disable the Correctable Errors Collector,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4137) see CONFIG_RAS_CEC help text.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4138)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4139) rcu_nocbs= [KNL]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4140) The argument is a cpu list, as described above,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4141) except that the string "all" can be used to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4142) specify every CPU on the system.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4143)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4144) In kernels built with CONFIG_RCU_NOCB_CPU=y, set
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4145) the specified list of CPUs to be no-callback CPUs.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4146) Invocation of these CPUs' RCU callbacks will be
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4147) offloaded to "rcuox/N" kthreads created for that
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4148) purpose, where "x" is "p" for RCU-preempt, and
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4149) "s" for RCU-sched, and "N" is the CPU number.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4150) This reduces OS jitter on the offloaded CPUs,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4151) which can be useful for HPC and real-time
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4152) workloads. It can also improve energy efficiency
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4153) for asymmetric multiprocessors.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4154)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4155) rcu_nocb_poll [KNL]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4156) Rather than requiring that offloaded CPUs
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4157) (specified by rcu_nocbs= above) explicitly
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4158) awaken the corresponding "rcuoN" kthreads,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4159) make these kthreads poll for callbacks.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4160) This improves the real-time response for the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4161) offloaded CPUs by relieving them of the need to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4162) wake up the corresponding kthread, but degrades
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4163) energy efficiency by requiring that the kthreads
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4164) periodically wake up to do the polling.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4165)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4166) rcutree.blimit= [KNL]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4167) Set maximum number of finished RCU callbacks to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4168) process in one batch.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4169)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4170) rcutree.dump_tree= [KNL]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4171) Dump the structure of the rcu_node combining tree
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4172) out at early boot. This is used for diagnostic
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4173) purposes, to verify correct tree setup.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4174)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4175) rcutree.gp_cleanup_delay= [KNL]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4176) Set the number of jiffies to delay each step of
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4177) RCU grace-period cleanup.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4178)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4179) rcutree.gp_init_delay= [KNL]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4180) Set the number of jiffies to delay each step of
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4181) RCU grace-period initialization.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4182)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4183) rcutree.gp_preinit_delay= [KNL]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4184) Set the number of jiffies to delay each step of
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4185) RCU grace-period pre-initialization, that is,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4186) the propagation of recent CPU-hotplug changes up
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4187) the rcu_node combining tree.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4188)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4189) rcutree.use_softirq= [KNL]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4190) If set to zero, move all RCU_SOFTIRQ processing to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4191) per-CPU rcuc kthreads. Defaults to a non-zero
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4192) value, meaning that RCU_SOFTIRQ is used by default.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4193) Specify rcutree.use_softirq=0 to use rcuc kthreads.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4194)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4195) rcutree.rcu_fanout_exact= [KNL]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4196) Disable autobalancing of the rcu_node combining
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4197) tree. This is used by rcutorture, and might
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4198) possibly be useful for architectures having high
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4199) cache-to-cache transfer latencies.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4200)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4201) rcutree.rcu_fanout_leaf= [KNL]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4202) Change the number of CPUs assigned to each
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4203) leaf rcu_node structure. Useful for very
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4204) large systems, which will choose the value 64,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4205) and for NUMA systems with large remote-access
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4206) latencies, which will choose a value aligned
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4207) with the appropriate hardware boundaries.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4208)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4209) rcutree.rcu_min_cached_objs= [KNL]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4210) Minimum number of objects which are cached and
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4211) maintained per one CPU. Object size is equal
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4212) to PAGE_SIZE. The cache allows to reduce the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4213) pressure to page allocator, also it makes the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4214) whole algorithm to behave better in low memory
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4215) condition.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4216)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4217) rcutree.jiffies_till_first_fqs= [KNL]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4218) Set delay from grace-period initialization to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4219) first attempt to force quiescent states.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4220) Units are jiffies, minimum value is zero,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4221) and maximum value is HZ.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4222)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4223) rcutree.jiffies_till_next_fqs= [KNL]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4224) Set delay between subsequent attempts to force
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4225) quiescent states. Units are jiffies, minimum
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4226) value is one, and maximum value is HZ.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4227)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4228) rcutree.jiffies_till_sched_qs= [KNL]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4229) Set required age in jiffies for a
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4230) given grace period before RCU starts
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4231) soliciting quiescent-state help from
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4232) rcu_note_context_switch() and cond_resched().
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4233) If not specified, the kernel will calculate
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4234) a value based on the most recent settings
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4235) of rcutree.jiffies_till_first_fqs
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4236) and rcutree.jiffies_till_next_fqs.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4237) This calculated value may be viewed in
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4238) rcutree.jiffies_to_sched_qs. Any attempt to set
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4239) rcutree.jiffies_to_sched_qs will be cheerfully
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4240) overwritten.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4241)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4242) rcutree.kthread_prio= [KNL,BOOT]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4243) Set the SCHED_FIFO priority of the RCU per-CPU
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4244) kthreads (rcuc/N). This value is also used for
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4245) the priority of the RCU boost threads (rcub/N)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4246) and for the RCU grace-period kthreads (rcu_bh,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4247) rcu_preempt, and rcu_sched). If RCU_BOOST is
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4248) set, valid values are 1-99 and the default is 1
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4249) (the least-favored priority). Otherwise, when
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4250) RCU_BOOST is not set, valid values are 0-99 and
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4251) the default is zero (non-realtime operation).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4252)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4253) rcutree.rcu_nocb_gp_stride= [KNL]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4254) Set the number of NOCB callback kthreads in
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4255) each group, which defaults to the square root
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4256) of the number of CPUs. Larger numbers reduce
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4257) the wakeup overhead on the global grace-period
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4258) kthread, but increases that same overhead on
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4259) each group's NOCB grace-period kthread.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4260)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4261) rcutree.qhimark= [KNL]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4262) Set threshold of queued RCU callbacks beyond which
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4263) batch limiting is disabled.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4264)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4265) rcutree.qlowmark= [KNL]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4266) Set threshold of queued RCU callbacks below which
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4267) batch limiting is re-enabled.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4268)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4269) rcutree.qovld= [KNL]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4270) Set threshold of queued RCU callbacks beyond which
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4271) RCU's force-quiescent-state scan will aggressively
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4272) enlist help from cond_resched() and sched IPIs to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4273) help CPUs more quickly reach quiescent states.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4274) Set to less than zero to make this be set based
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4275) on rcutree.qhimark at boot time and to zero to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4276) disable more aggressive help enlistment.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4277)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4278) rcutree.rcu_idle_gp_delay= [KNL]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4279) Set wakeup interval for idle CPUs that have
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4280) RCU callbacks (RCU_FAST_NO_HZ=y).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4281)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4282) rcutree.rcu_idle_lazy_gp_delay= [KNL]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4283) Set wakeup interval for idle CPUs that have
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4284) only "lazy" RCU callbacks (RCU_FAST_NO_HZ=y).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4285) Lazy RCU callbacks are those which RCU can
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4286) prove do nothing more than free memory.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4287)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4288) rcutree.rcu_kick_kthreads= [KNL]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4289) Cause the grace-period kthread to get an extra
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4290) wake_up() if it sleeps three times longer than
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4291) it should at force-quiescent-state time.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4292) This wake_up() will be accompanied by a
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4293) WARN_ONCE() splat and an ftrace_dump().
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4294)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4295) rcutree.rcu_unlock_delay= [KNL]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4296) In CONFIG_RCU_STRICT_GRACE_PERIOD=y kernels,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4297) this specifies an rcu_read_unlock()-time delay
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4298) in microseconds. This defaults to zero.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4299) Larger delays increase the probability of
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4300) catching RCU pointer leaks, that is, buggy use
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4301) of RCU-protected pointers after the relevant
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4302) rcu_read_unlock() has completed.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4303)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4304) rcutree.sysrq_rcu= [KNL]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4305) Commandeer a sysrq key to dump out Tree RCU's
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4306) rcu_node tree with an eye towards determining
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4307) why a new grace period has not yet started.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4308)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4309) rcuscale.gp_async= [KNL]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4310) Measure performance of asynchronous
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4311) grace-period primitives such as call_rcu().
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4312)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4313) rcuscale.gp_async_max= [KNL]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4314) Specify the maximum number of outstanding
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4315) callbacks per writer thread. When a writer
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4316) thread exceeds this limit, it invokes the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4317) corresponding flavor of rcu_barrier() to allow
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4318) previously posted callbacks to drain.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4319)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4320) rcuscale.gp_exp= [KNL]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4321) Measure performance of expedited synchronous
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4322) grace-period primitives.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4323)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4324) rcuscale.holdoff= [KNL]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4325) Set test-start holdoff period. The purpose of
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4326) this parameter is to delay the start of the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4327) test until boot completes in order to avoid
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4328) interference.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4329)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4330) rcuscale.kfree_rcu_test= [KNL]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4331) Set to measure performance of kfree_rcu() flooding.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4332)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4333) rcuscale.kfree_nthreads= [KNL]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4334) The number of threads running loops of kfree_rcu().
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4335)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4336) rcuscale.kfree_alloc_num= [KNL]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4337) Number of allocations and frees done in an iteration.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4338)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4339) rcuscale.kfree_loops= [KNL]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4340) Number of loops doing rcuscale.kfree_alloc_num number
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4341) of allocations and frees.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4342)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4343) rcuscale.nreaders= [KNL]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4344) Set number of RCU readers. The value -1 selects
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4345) N, where N is the number of CPUs. A value
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4346) "n" less than -1 selects N-n+1, where N is again
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4347) the number of CPUs. For example, -2 selects N
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4348) (the number of CPUs), -3 selects N+1, and so on.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4349) A value of "n" less than or equal to -N selects
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4350) a single reader.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4351)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4352) rcuscale.nwriters= [KNL]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4353) Set number of RCU writers. The values operate
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4354) the same as for rcuscale.nreaders.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4355) N, where N is the number of CPUs
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4356)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4357) rcuscale.perf_type= [KNL]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4358) Specify the RCU implementation to test.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4359)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4360) rcuscale.shutdown= [KNL]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4361) Shut the system down after performance tests
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4362) complete. This is useful for hands-off automated
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4363) testing.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4364)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4365) rcuscale.verbose= [KNL]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4366) Enable additional printk() statements.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4367)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4368) rcuscale.writer_holdoff= [KNL]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4369) Write-side holdoff between grace periods,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4370) in microseconds. The default of zero says
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4371) no holdoff.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4372)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4373) rcutorture.fqs_duration= [KNL]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4374) Set duration of force_quiescent_state bursts
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4375) in microseconds.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4376)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4377) rcutorture.fqs_holdoff= [KNL]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4378) Set holdoff time within force_quiescent_state bursts
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4379) in microseconds.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4380)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4381) rcutorture.fqs_stutter= [KNL]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4382) Set wait time between force_quiescent_state bursts
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4383) in seconds.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4384)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4385) rcutorture.fwd_progress= [KNL]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4386) Enable RCU grace-period forward-progress testing
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4387) for the types of RCU supporting this notion.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4388)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4389) rcutorture.fwd_progress_div= [KNL]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4390) Specify the fraction of a CPU-stall-warning
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4391) period to do tight-loop forward-progress testing.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4392)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4393) rcutorture.fwd_progress_holdoff= [KNL]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4394) Number of seconds to wait between successive
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4395) forward-progress tests.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4396)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4397) rcutorture.fwd_progress_need_resched= [KNL]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4398) Enclose cond_resched() calls within checks for
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4399) need_resched() during tight-loop forward-progress
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4400) testing.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4401)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4402) rcutorture.gp_cond= [KNL]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4403) Use conditional/asynchronous update-side
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4404) primitives, if available.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4405)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4406) rcutorture.gp_exp= [KNL]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4407) Use expedited update-side primitives, if available.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4408)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4409) rcutorture.gp_normal= [KNL]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4410) Use normal (non-expedited) asynchronous
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4411) update-side primitives, if available.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4412)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4413) rcutorture.gp_sync= [KNL]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4414) Use normal (non-expedited) synchronous
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4415) update-side primitives, if available. If all
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4416) of rcutorture.gp_cond=, rcutorture.gp_exp=,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4417) rcutorture.gp_normal=, and rcutorture.gp_sync=
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4418) are zero, rcutorture acts as if is interpreted
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4419) they are all non-zero.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4420)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4421) rcutorture.irqreader= [KNL]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4422) Run RCU readers from irq handlers, or, more
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4423) accurately, from a timer handler. Not all RCU
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4424) flavors take kindly to this sort of thing.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4425)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4426) rcutorture.leakpointer= [KNL]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4427) Leak an RCU-protected pointer out of the reader.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4428) This can of course result in splats, and is
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4429) intended to test the ability of things like
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4430) CONFIG_RCU_STRICT_GRACE_PERIOD=y to detect
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4431) such leaks.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4432)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4433) rcutorture.n_barrier_cbs= [KNL]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4434) Set callbacks/threads for rcu_barrier() testing.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4435)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4436) rcutorture.nfakewriters= [KNL]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4437) Set number of concurrent RCU writers. These just
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4438) stress RCU, they don't participate in the actual
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4439) test, hence the "fake".
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4440)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4441) rcutorture.nreaders= [KNL]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4442) Set number of RCU readers. The value -1 selects
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4443) N-1, where N is the number of CPUs. A value
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4444) "n" less than -1 selects N-n-2, where N is again
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4445) the number of CPUs. For example, -2 selects N
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4446) (the number of CPUs), -3 selects N+1, and so on.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4447)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4448) rcutorture.object_debug= [KNL]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4449) Enable debug-object double-call_rcu() testing.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4450)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4451) rcutorture.onoff_holdoff= [KNL]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4452) Set time (s) after boot for CPU-hotplug testing.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4453)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4454) rcutorture.onoff_interval= [KNL]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4455) Set time (jiffies) between CPU-hotplug operations,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4456) or zero to disable CPU-hotplug testing.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4457)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4458) rcutorture.read_exit= [KNL]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4459) Set the number of read-then-exit kthreads used
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4460) to test the interaction of RCU updaters and
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4461) task-exit processing.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4462)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4463) rcutorture.read_exit_burst= [KNL]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4464) The number of times in a given read-then-exit
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4465) episode that a set of read-then-exit kthreads
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4466) is spawned.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4467)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4468) rcutorture.read_exit_delay= [KNL]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4469) The delay, in seconds, between successive
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4470) read-then-exit testing episodes.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4471)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4472) rcutorture.shuffle_interval= [KNL]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4473) Set task-shuffle interval (s). Shuffling tasks
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4474) allows some CPUs to go into dyntick-idle mode
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4475) during the rcutorture test.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4476)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4477) rcutorture.shutdown_secs= [KNL]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4478) Set time (s) after boot system shutdown. This
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4479) is useful for hands-off automated testing.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4480)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4481) rcutorture.stall_cpu= [KNL]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4482) Duration of CPU stall (s) to test RCU CPU stall
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4483) warnings, zero to disable.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4484)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4485) rcutorture.stall_cpu_block= [KNL]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4486) Sleep while stalling if set. This will result
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4487) in warnings from preemptible RCU in addition
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4488) to any other stall-related activity.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4489)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4490) rcutorture.stall_cpu_holdoff= [KNL]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4491) Time to wait (s) after boot before inducing stall.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4492)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4493) rcutorture.stall_cpu_irqsoff= [KNL]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4494) Disable interrupts while stalling if set.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4495)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4496) rcutorture.stall_gp_kthread= [KNL]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4497) Duration (s) of forced sleep within RCU
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4498) grace-period kthread to test RCU CPU stall
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4499) warnings, zero to disable. If both stall_cpu
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4500) and stall_gp_kthread are specified, the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4501) kthread is starved first, then the CPU.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4502)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4503) rcutorture.stat_interval= [KNL]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4504) Time (s) between statistics printk()s.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4505)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4506) rcutorture.stutter= [KNL]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4507) Time (s) to stutter testing, for example, specifying
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4508) five seconds causes the test to run for five seconds,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4509) wait for five seconds, and so on. This tests RCU's
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4510) ability to transition abruptly to and from idle.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4511)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4512) rcutorture.test_boost= [KNL]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4513) Test RCU priority boosting? 0=no, 1=maybe, 2=yes.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4514) "Maybe" means test if the RCU implementation
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4515) under test support RCU priority boosting.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4516)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4517) rcutorture.test_boost_duration= [KNL]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4518) Duration (s) of each individual boost test.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4519)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4520) rcutorture.test_boost_interval= [KNL]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4521) Interval (s) between each boost test.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4522)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4523) rcutorture.test_no_idle_hz= [KNL]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4524) Test RCU's dyntick-idle handling. See also the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4525) rcutorture.shuffle_interval parameter.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4526)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4527) rcutorture.torture_type= [KNL]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4528) Specify the RCU implementation to test.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4529)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4530) rcutorture.verbose= [KNL]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4531) Enable additional printk() statements.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4532)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4533) rcupdate.rcu_cpu_stall_ftrace_dump= [KNL]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4534) Dump ftrace buffer after reporting RCU CPU
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4535) stall warning.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4536)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4537) rcupdate.rcu_cpu_stall_suppress= [KNL]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4538) Suppress RCU CPU stall warning messages.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4539)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4540) rcupdate.rcu_cpu_stall_suppress_at_boot= [KNL]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4541) Suppress RCU CPU stall warning messages and
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4542) rcutorture writer stall warnings that occur
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4543) during early boot, that is, during the time
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4544) before the init task is spawned.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4545)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4546) rcupdate.rcu_cpu_stall_timeout= [KNL]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4547) Set timeout for RCU CPU stall warning messages.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4548)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4549) rcupdate.rcu_expedited= [KNL]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4550) Use expedited grace-period primitives, for
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4551) example, synchronize_rcu_expedited() instead
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4552) of synchronize_rcu(). This reduces latency,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4553) but can increase CPU utilization, degrade
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4554) real-time latency, and degrade energy efficiency.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4555) No effect on CONFIG_TINY_RCU kernels.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4556)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4557) rcupdate.rcu_normal= [KNL]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4558) Use only normal grace-period primitives,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4559) for example, synchronize_rcu() instead of
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4560) synchronize_rcu_expedited(). This improves
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4561) real-time latency, CPU utilization, and
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4562) energy efficiency, but can expose users to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4563) increased grace-period latency. This parameter
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4564) overrides rcupdate.rcu_expedited. No effect on
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4565) CONFIG_TINY_RCU kernels.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4566)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4567) rcupdate.rcu_normal_after_boot= [KNL]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4568) Once boot has completed (that is, after
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4569) rcu_end_inkernel_boot() has been invoked), use
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4570) only normal grace-period primitives. No effect
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4571) on CONFIG_TINY_RCU kernels.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4572)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4573) rcupdate.rcu_task_ipi_delay= [KNL]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4574) Set time in jiffies during which RCU tasks will
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4575) avoid sending IPIs, starting with the beginning
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4576) of a given grace period. Setting a large
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4577) number avoids disturbing real-time workloads,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4578) but lengthens grace periods.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4579)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4580) rcupdate.rcu_task_stall_timeout= [KNL]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4581) Set timeout in jiffies for RCU task stall warning
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4582) messages. Disable with a value less than or equal
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4583) to zero.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4584)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4585) rcupdate.rcu_self_test= [KNL]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4586) Run the RCU early boot self tests
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4587)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4588) rdinit= [KNL]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4589) Format: <full_path>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4590) Run specified binary instead of /init from the ramdisk,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4591) used for early userspace startup. See initrd.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4592)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4593) rdrand= [X86]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4594) force - Override the decision by the kernel to hide the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4595) advertisement of RDRAND support (this affects
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4596) certain AMD processors because of buggy BIOS
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4597) support, specifically around the suspend/resume
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4598) path).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4599)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4600) rdt= [HW,X86,RDT]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4601) Turn on/off individual RDT features. List is:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4602) cmt, mbmtotal, mbmlocal, l3cat, l3cdp, l2cat, l2cdp,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4603) mba.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4604) E.g. to turn on cmt and turn off mba use:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4605) rdt=cmt,!mba
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4606)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4607) reboot= [KNL]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4608) Format (x86 or x86_64):
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4609) [w[arm] | c[old] | h[ard] | s[oft] | g[pio]] \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4610) [[,]s[mp]#### \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4611) [[,]b[ios] | a[cpi] | k[bd] | t[riple] | e[fi] | p[ci]] \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4612) [[,]f[orce]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4613) Where reboot_mode is one of warm (soft) or cold (hard) or gpio
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4614) (prefix with 'panic_' to set mode for panic
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4615) reboot only),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4616) reboot_type is one of bios, acpi, kbd, triple, efi, or pci,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4617) reboot_force is either force or not specified,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4618) reboot_cpu is s[mp]#### with #### being the processor
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4619) to be used for rebooting.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4620)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4621) refscale.holdoff= [KNL]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4622) Set test-start holdoff period. The purpose of
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4623) this parameter is to delay the start of the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4624) test until boot completes in order to avoid
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4625) interference.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4626)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4627) refscale.loops= [KNL]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4628) Set the number of loops over the synchronization
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4629) primitive under test. Increasing this number
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4630) reduces noise due to loop start/end overhead,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4631) but the default has already reduced the per-pass
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4632) noise to a handful of picoseconds on ca. 2020
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4633) x86 laptops.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4634)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4635) refscale.nreaders= [KNL]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4636) Set number of readers. The default value of -1
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4637) selects N, where N is roughly 75% of the number
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4638) of CPUs. A value of zero is an interesting choice.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4639)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4640) refscale.nruns= [KNL]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4641) Set number of runs, each of which is dumped onto
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4642) the console log.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4643)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4644) refscale.readdelay= [KNL]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4645) Set the read-side critical-section duration,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4646) measured in microseconds.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4647)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4648) refscale.scale_type= [KNL]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4649) Specify the read-protection implementation to test.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4650)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4651) refscale.shutdown= [KNL]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4652) Shut down the system at the end of the performance
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4653) test. This defaults to 1 (shut it down) when
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4654) refscale is built into the kernel and to 0 (leave
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4655) it running) when refscale is built as a module.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4656)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4657) refscale.verbose= [KNL]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4658) Enable additional printk() statements.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4659)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4660) relax_domain_level=
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4661) [KNL, SMP] Set scheduler's default relax_domain_level.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4662) See Documentation/admin-guide/cgroup-v1/cpusets.rst.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4663)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4664) reserve= [KNL,BUGS] Force kernel to ignore I/O ports or memory
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4665) Format: <base1>,<size1>[,<base2>,<size2>,...]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4666) Reserve I/O ports or memory so the kernel won't use
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4667) them. If <base> is less than 0x10000, the region
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4668) is assumed to be I/O ports; otherwise it is memory.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4669)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4670) reservetop= [X86-32]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4671) Format: nn[KMG]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4672) Reserves a hole at the top of the kernel virtual
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4673) address space.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4674)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4675) reservelow= [X86]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4676) Format: nn[K]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4677) Set the amount of memory to reserve for BIOS at
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4678) the bottom of the address space.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4679)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4680) reset_devices [KNL] Force drivers to reset the underlying device
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4681) during initialization.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4682)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4683) resume= [SWSUSP]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4684) Specify the partition device for software suspend
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4685) Format:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4686) {/dev/<dev> | PARTUUID=<uuid> | <int>:<int> | <hex>}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4687)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4688) resume_offset= [SWSUSP]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4689) Specify the offset from the beginning of the partition
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4690) given by "resume=" at which the swap header is located,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4691) in <PAGE_SIZE> units (needed only for swap files).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4692) See Documentation/power/swsusp-and-swap-files.rst
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4693)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4694) resumedelay= [HIBERNATION] Delay (in seconds) to pause before attempting to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4695) read the resume files
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4696)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4697) resumewait [HIBERNATION] Wait (indefinitely) for resume device to show up.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4698) Useful for devices that are detected asynchronously
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4699) (e.g. USB and MMC devices).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4700)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4701) hibernate= [HIBERNATION]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4702) noresume Don't check if there's a hibernation image
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4703) present during boot.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4704) nocompress Don't compress/decompress hibernation images.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4705) no Disable hibernation and resume.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4706) protect_image Turn on image protection during restoration
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4707) (that will set all pages holding image data
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4708) during restoration read-only).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4709)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4710) retain_initrd [RAM] Keep initrd memory after extraction
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4711)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4712) rfkill.default_state=
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4713) 0 "airplane mode". All wifi, bluetooth, wimax, gps, fm,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4714) etc. communication is blocked by default.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4715) 1 Unblocked.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4716)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4717) rfkill.master_switch_mode=
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4718) 0 The "airplane mode" button does nothing.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4719) 1 The "airplane mode" button toggles between everything
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4720) blocked and the previous configuration.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4721) 2 The "airplane mode" button toggles between everything
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4722) blocked and everything unblocked.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4723)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4724) rhash_entries= [KNL,NET]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4725) Set number of hash buckets for route cache
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4726)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4727) ring3mwait=disable
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4728) [KNL] Disable ring 3 MONITOR/MWAIT feature on supported
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4729) CPUs.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4730)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4731) ro [KNL] Mount root device read-only on boot
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4732)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4733) rodata= [KNL]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4734) on Mark read-only kernel memory as read-only (default).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4735) off Leave read-only kernel memory writable for debugging.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4736)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4737) rockchip.usb_uart
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4738) Enable the uart passthrough on the designated usb port
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4739) on Rockchip SoCs. When active, the signals of the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4740) debug-uart get routed to the D+ and D- pins of the usb
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4741) port and the regular usb controller gets disabled.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4742)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4743) root= [KNL] Root filesystem
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4744) See name_to_dev_t comment in init/do_mounts.c.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4745)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4746) rootdelay= [KNL] Delay (in seconds) to pause before attempting to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4747) mount the root filesystem
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4748)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4749) rootflags= [KNL] Set root filesystem mount option string
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4750)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4751) rootfstype= [KNL] Set root filesystem type
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4752)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4753) rootwait [KNL] Wait (indefinitely) for root device to show up.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4754) Useful for devices that are detected asynchronously
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4755) (e.g. USB and MMC devices).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4756)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4757) rproc_mem=nn[KMG][@address]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4758) [KNL,ARM,CMA] Remoteproc physical memory block.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4759) Memory area to be used by remote processor image,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4760) managed by CMA.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4761)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4762) rw [KNL] Mount root device read-write on boot
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4763)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4764) S [KNL] Run init in single mode
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4765)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4766) s390_iommu= [HW,S390]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4767) Set s390 IOTLB flushing mode
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4768) strict
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4769) With strict flushing every unmap operation will result in
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4770) an IOTLB flush. Default is lazy flushing before reuse,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4771) which is faster.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4772)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4773) sa1100ir [NET]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4774) See drivers/net/irda/sa1100_ir.c.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4775)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4776) sbni= [NET] Granch SBNI12 leased line adapter
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4777)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4778) sched_debug [KNL] Enables verbose scheduler debug messages.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4779)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4780) schedstats= [KNL,X86] Enable or disable scheduled statistics.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4781) Allowed values are enable and disable. This feature
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4782) incurs a small amount of overhead in the scheduler
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4783) but is useful for debugging and performance tuning.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4784)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4785) sched_thermal_decay_shift=
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4786) [KNL, SMP] Set a decay shift for scheduler thermal
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4787) pressure signal. Thermal pressure signal follows the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4788) default decay period of other scheduler pelt
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4789) signals(usually 32 ms but configurable). Setting
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4790) sched_thermal_decay_shift will left shift the decay
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4791) period for the thermal pressure signal by the shift
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4792) value.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4793) i.e. with the default pelt decay period of 32 ms
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4794) sched_thermal_decay_shift thermal pressure decay pr
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4795) 1 64 ms
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4796) 2 128 ms
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4797) and so on.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4798) Format: integer between 0 and 10
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4799) Default is 0.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4800)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4801) scftorture.holdoff= [KNL]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4802) Number of seconds to hold off before starting
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4803) test. Defaults to zero for module insertion and
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4804) to 10 seconds for built-in smp_call_function()
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4805) tests.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4806)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4807) scftorture.longwait= [KNL]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4808) Request ridiculously long waits randomly selected
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4809) up to the chosen limit in seconds. Zero (the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4810) default) disables this feature. Please note
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4811) that requesting even small non-zero numbers of
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4812) seconds can result in RCU CPU stall warnings,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4813) softlockup complaints, and so on.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4814)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4815) scftorture.nthreads= [KNL]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4816) Number of kthreads to spawn to invoke the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4817) smp_call_function() family of functions.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4818) The default of -1 specifies a number of kthreads
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4819) equal to the number of CPUs.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4820)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4821) scftorture.onoff_holdoff= [KNL]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4822) Number seconds to wait after the start of the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4823) test before initiating CPU-hotplug operations.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4824)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4825) scftorture.onoff_interval= [KNL]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4826) Number seconds to wait between successive
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4827) CPU-hotplug operations. Specifying zero (which
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4828) is the default) disables CPU-hotplug operations.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4829)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4830) scftorture.shutdown_secs= [KNL]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4831) The number of seconds following the start of the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4832) test after which to shut down the system. The
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4833) default of zero avoids shutting down the system.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4834) Non-zero values are useful for automated tests.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4835)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4836) scftorture.stat_interval= [KNL]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4837) The number of seconds between outputting the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4838) current test statistics to the console. A value
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4839) of zero disables statistics output.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4840)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4841) scftorture.stutter_cpus= [KNL]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4842) The number of jiffies to wait between each change
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4843) to the set of CPUs under test.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4844)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4845) scftorture.use_cpus_read_lock= [KNL]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4846) Use use_cpus_read_lock() instead of the default
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4847) preempt_disable() to disable CPU hotplug
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4848) while invoking one of the smp_call_function*()
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4849) functions.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4850)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4851) scftorture.verbose= [KNL]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4852) Enable additional printk() statements.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4853)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4854) scftorture.weight_single= [KNL]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4855) The probability weighting to use for the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4856) smp_call_function_single() function with a zero
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4857) "wait" parameter. A value of -1 selects the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4858) default if all other weights are -1. However,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4859) if at least one weight has some other value, a
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4860) value of -1 will instead select a weight of zero.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4861)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4862) scftorture.weight_single_wait= [KNL]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4863) The probability weighting to use for the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4864) smp_call_function_single() function with a
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4865) non-zero "wait" parameter. See weight_single.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4866)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4867) scftorture.weight_many= [KNL]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4868) The probability weighting to use for the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4869) smp_call_function_many() function with a zero
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4870) "wait" parameter. See weight_single.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4871) Note well that setting a high probability for
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4872) this weighting can place serious IPI load
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4873) on the system.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4874)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4875) scftorture.weight_many_wait= [KNL]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4876) The probability weighting to use for the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4877) smp_call_function_many() function with a
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4878) non-zero "wait" parameter. See weight_single
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4879) and weight_many.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4880)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4881) scftorture.weight_all= [KNL]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4882) The probability weighting to use for the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4883) smp_call_function_all() function with a zero
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4884) "wait" parameter. See weight_single and
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4885) weight_many.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4886)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4887) scftorture.weight_all_wait= [KNL]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4888) The probability weighting to use for the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4889) smp_call_function_all() function with a
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4890) non-zero "wait" parameter. See weight_single
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4891) and weight_many.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4892)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4893) skew_tick= [KNL] Offset the periodic timer tick per cpu to mitigate
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4894) xtime_lock contention on larger systems, and/or RCU lock
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4895) contention on all systems with CONFIG_MAXSMP set.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4896) Format: { "0" | "1" }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4897) 0 -- disable. (may be 1 via CONFIG_CMDLINE="skew_tick=1"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4898) 1 -- enable.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4899) Note: increases power consumption, thus should only be
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4900) enabled if running jitter sensitive (HPC/RT) workloads.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4901)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4902) security= [SECURITY] Choose a legacy "major" security module to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4903) enable at boot. This has been deprecated by the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4904) "lsm=" parameter.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4905)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4906) selinux= [SELINUX] Disable or enable SELinux at boot time.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4907) Format: { "0" | "1" }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4908) See security/selinux/Kconfig help text.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4909) 0 -- disable.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4910) 1 -- enable.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4911) Default value is 1.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4912)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4913) apparmor= [APPARMOR] Disable or enable AppArmor at boot time
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4914) Format: { "0" | "1" }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4915) See security/apparmor/Kconfig help text
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4916) 0 -- disable.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4917) 1 -- enable.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4918) Default value is set via kernel config option.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4919)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4920) serialnumber [BUGS=X86-32]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4921)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4922) shapers= [NET]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4923) Maximal number of shapers.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4924)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4925) simeth= [IA-64]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4926) simscsi=
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4927)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4928) slram= [HW,MTD]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4929)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4930) slab_nomerge [MM]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4931) Disable merging of slabs with similar size. May be
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4932) necessary if there is some reason to distinguish
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4933) allocs to different slabs, especially in hardened
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4934) environments where the risk of heap overflows and
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4935) layout control by attackers can usually be
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4936) frustrated by disabling merging. This will reduce
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4937) most of the exposure of a heap attack to a single
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4938) cache (risks via metadata attacks are mostly
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4939) unchanged). Debug options disable merging on their
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4940) own.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4941) For more information see Documentation/vm/slub.rst.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4942)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4943) slab_max_order= [MM, SLAB]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4944) Determines the maximum allowed order for slabs.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4945) A high setting may cause OOMs due to memory
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4946) fragmentation. Defaults to 1 for systems with
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4947) more than 32MB of RAM, 0 otherwise.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4948)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4949) slub_debug[=options[,slabs][;[options[,slabs]]...] [MM, SLUB]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4950) Enabling slub_debug allows one to determine the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4951) culprit if slab objects become corrupted. Enabling
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4952) slub_debug can create guard zones around objects and
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4953) may poison objects when not in use. Also tracks the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4954) last alloc / free. For more information see
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4955) Documentation/vm/slub.rst.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4956)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4957) slub_memcg_sysfs= [MM, SLUB]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4958) Determines whether to enable sysfs directories for
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4959) memory cgroup sub-caches. 1 to enable, 0 to disable.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4960) The default is determined by CONFIG_SLUB_MEMCG_SYSFS_ON.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4961) Enabling this can lead to a very high number of debug
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4962) directories and files being created under
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4963) /sys/kernel/slub.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4964)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4965) slub_max_order= [MM, SLUB]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4966) Determines the maximum allowed order for slabs.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4967) A high setting may cause OOMs due to memory
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4968) fragmentation. For more information see
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4969) Documentation/vm/slub.rst.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4970)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4971) slub_min_objects= [MM, SLUB]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4972) The minimum number of objects per slab. SLUB will
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4973) increase the slab order up to slub_max_order to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4974) generate a sufficiently large slab able to contain
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4975) the number of objects indicated. The higher the number
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4976) of objects the smaller the overhead of tracking slabs
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4977) and the less frequently locks need to be acquired.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4978) For more information see Documentation/vm/slub.rst.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4979)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4980) slub_min_order= [MM, SLUB]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4981) Determines the minimum page order for slabs. Must be
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4982) lower than slub_max_order.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4983) For more information see Documentation/vm/slub.rst.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4984)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4985) slub_nomerge [MM, SLUB]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4986) Same with slab_nomerge. This is supported for legacy.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4987) See slab_nomerge for more information.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4988)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4989) smart2= [HW]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4990) Format: <io1>[,<io2>[,...,<io8>]]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4991)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4992) smsc-ircc2.nopnp [HW] Don't use PNP to discover SMC devices
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4993) smsc-ircc2.ircc_cfg= [HW] Device configuration I/O port
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4994) smsc-ircc2.ircc_sir= [HW] SIR base I/O port
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4995) smsc-ircc2.ircc_fir= [HW] FIR base I/O port
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4996) smsc-ircc2.ircc_irq= [HW] IRQ line
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4997) smsc-ircc2.ircc_dma= [HW] DMA channel
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4998) smsc-ircc2.ircc_transceiver= [HW] Transceiver type:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4999) 0: Toshiba Satellite 1800 (GP data pin select)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5000) 1: Fast pin select (default)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5001) 2: ATC IRMode
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5002)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5003) smt [KNL,S390] Set the maximum number of threads (logical
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5004) CPUs) to use per physical CPU on systems capable of
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5005) symmetric multithreading (SMT). Will be capped to the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5006) actual hardware limit.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5007) Format: <integer>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5008) Default: -1 (no limit)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5009)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5010) softlockup_panic=
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5011) [KNL] Should the soft-lockup detector generate panics.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5012) Format: 0 | 1
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5013)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5014) A value of 1 instructs the soft-lockup detector
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5015) to panic the machine when a soft-lockup occurs. It is
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5016) also controlled by the kernel.softlockup_panic sysctl
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5017) and CONFIG_BOOTPARAM_SOFTLOCKUP_PANIC, which is the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5018) respective build-time switch to that functionality.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5019)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5020) softlockup_all_cpu_backtrace=
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5021) [KNL] Should the soft-lockup detector generate
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5022) backtraces on all cpus.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5023) Format: 0 | 1
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5024)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5025) sonypi.*= [HW] Sony Programmable I/O Control Device driver
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5026) See Documentation/admin-guide/laptops/sonypi.rst
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5027)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5028) spectre_v2= [X86] Control mitigation of Spectre variant 2
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5029) (indirect branch speculation) vulnerability.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5030) The default operation protects the kernel from
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5031) user space attacks.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5032)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5033) on - unconditionally enable, implies
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5034) spectre_v2_user=on
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5035) off - unconditionally disable, implies
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5036) spectre_v2_user=off
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5037) auto - kernel detects whether your CPU model is
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5038) vulnerable
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5039)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5040) Selecting 'on' will, and 'auto' may, choose a
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5041) mitigation method at run time according to the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5042) CPU, the available microcode, the setting of the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5043) CONFIG_RETPOLINE configuration option, and the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5044) compiler with which the kernel was built.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5045)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5046) Selecting 'on' will also enable the mitigation
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5047) against user space to user space task attacks.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5048)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5049) Selecting 'off' will disable both the kernel and
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5050) the user space protections.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5051)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5052) Specific mitigations can also be selected manually:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5053)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5054) retpoline - replace indirect branches
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5055) retpoline,generic - Retpolines
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5056) retpoline,lfence - LFENCE; indirect branch
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5057) retpoline,amd - alias for retpoline,lfence
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5058) eibrs - enhanced IBRS
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5059) eibrs,retpoline - enhanced IBRS + Retpolines
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5060) eibrs,lfence - enhanced IBRS + LFENCE
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5061)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5062) Not specifying this option is equivalent to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5063) spectre_v2=auto.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5064)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5065) spectre_v2_user=
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5066) [X86] Control mitigation of Spectre variant 2
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5067) (indirect branch speculation) vulnerability between
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5068) user space tasks
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5069)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5070) on - Unconditionally enable mitigations. Is
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5071) enforced by spectre_v2=on
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5072)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5073) off - Unconditionally disable mitigations. Is
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5074) enforced by spectre_v2=off
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5075)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5076) prctl - Indirect branch speculation is enabled,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5077) but mitigation can be enabled via prctl
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5078) per thread. The mitigation control state
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5079) is inherited on fork.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5080)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5081) prctl,ibpb
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5082) - Like "prctl" above, but only STIBP is
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5083) controlled per thread. IBPB is issued
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5084) always when switching between different user
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5085) space processes.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5086)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5087) seccomp
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5088) - Same as "prctl" above, but all seccomp
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5089) threads will enable the mitigation unless
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5090) they explicitly opt out.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5091)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5092) seccomp,ibpb
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5093) - Like "seccomp" above, but only STIBP is
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5094) controlled per thread. IBPB is issued
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5095) always when switching between different
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5096) user space processes.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5097)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5098) auto - Kernel selects the mitigation depending on
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5099) the available CPU features and vulnerability.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5100)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5101) Default mitigation:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5102) If CONFIG_SECCOMP=y then "seccomp", otherwise "prctl"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5103)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5104) Not specifying this option is equivalent to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5105) spectre_v2_user=auto.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5106)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5107) spec_store_bypass_disable=
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5108) [HW] Control Speculative Store Bypass (SSB) Disable mitigation
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5109) (Speculative Store Bypass vulnerability)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5110)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5111) Certain CPUs are vulnerable to an exploit against a
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5112) a common industry wide performance optimization known
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5113) as "Speculative Store Bypass" in which recent stores
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5114) to the same memory location may not be observed by
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5115) later loads during speculative execution. The idea
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5116) is that such stores are unlikely and that they can
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5117) be detected prior to instruction retirement at the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5118) end of a particular speculation execution window.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5119)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5120) In vulnerable processors, the speculatively forwarded
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5121) store can be used in a cache side channel attack, for
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5122) example to read memory to which the attacker does not
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5123) directly have access (e.g. inside sandboxed code).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5124)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5125) This parameter controls whether the Speculative Store
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5126) Bypass optimization is used.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5127)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5128) On x86 the options are:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5129)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5130) on - Unconditionally disable Speculative Store Bypass
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5131) off - Unconditionally enable Speculative Store Bypass
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5132) auto - Kernel detects whether the CPU model contains an
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5133) implementation of Speculative Store Bypass and
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5134) picks the most appropriate mitigation. If the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5135) CPU is not vulnerable, "off" is selected. If the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5136) CPU is vulnerable the default mitigation is
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5137) architecture and Kconfig dependent. See below.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5138) prctl - Control Speculative Store Bypass per thread
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5139) via prctl. Speculative Store Bypass is enabled
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5140) for a process by default. The state of the control
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5141) is inherited on fork.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5142) seccomp - Same as "prctl" above, but all seccomp threads
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5143) will disable SSB unless they explicitly opt out.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5144)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5145) Default mitigations:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5146) X86: If CONFIG_SECCOMP=y "seccomp", otherwise "prctl"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5147)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5148) On powerpc the options are:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5149)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5150) on,auto - On Power8 and Power9 insert a store-forwarding
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5151) barrier on kernel entry and exit. On Power7
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5152) perform a software flush on kernel entry and
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5153) exit.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5154) off - No action.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5155)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5156) Not specifying this option is equivalent to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5157) spec_store_bypass_disable=auto.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5158)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5159) spia_io_base= [HW,MTD]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5160) spia_fio_base=
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5161) spia_pedr=
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5162) spia_peddr=
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5163)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5164) split_lock_detect=
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5165) [X86] Enable split lock detection
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5166)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5167) When enabled (and if hardware support is present), atomic
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5168) instructions that access data across cache line
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5169) boundaries will result in an alignment check exception.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5170)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5171) off - not enabled
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5172)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5173) warn - the kernel will emit rate limited warnings
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5174) about applications triggering the #AC
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5175) exception. This mode is the default on CPUs
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5176) that supports split lock detection.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5177)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5178) fatal - the kernel will send SIGBUS to applications
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5179) that trigger the #AC exception.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5180)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5181) If an #AC exception is hit in the kernel or in
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5182) firmware (i.e. not while executing in user mode)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5183) the kernel will oops in either "warn" or "fatal"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5184) mode.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5185)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5186) srbds= [X86,INTEL]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5187) Control the Special Register Buffer Data Sampling
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5188) (SRBDS) mitigation.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5189)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5190) Certain CPUs are vulnerable to an MDS-like
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5191) exploit which can leak bits from the random
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5192) number generator.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5193)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5194) By default, this issue is mitigated by
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5195) microcode. However, the microcode fix can cause
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5196) the RDRAND and RDSEED instructions to become
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5197) much slower. Among other effects, this will
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5198) result in reduced throughput from /dev/urandom.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5199)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5200) The microcode mitigation can be disabled with
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5201) the following option:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5202)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5203) off: Disable mitigation and remove
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5204) performance impact to RDRAND and RDSEED
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5205)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5206) srcutree.counter_wrap_check [KNL]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5207) Specifies how frequently to check for
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5208) grace-period sequence counter wrap for the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5209) srcu_data structure's ->srcu_gp_seq_needed field.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5210) The greater the number of bits set in this kernel
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5211) parameter, the less frequently counter wrap will
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5212) be checked for. Note that the bottom two bits
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5213) are ignored.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5214)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5215) srcutree.exp_holdoff [KNL]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5216) Specifies how many nanoseconds must elapse
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5217) since the end of the last SRCU grace period for
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5218) a given srcu_struct until the next normal SRCU
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5219) grace period will be considered for automatic
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5220) expediting. Set to zero to disable automatic
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5221) expediting.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5222)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5223) ssbd= [ARM64,HW]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5224) Speculative Store Bypass Disable control
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5225)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5226) On CPUs that are vulnerable to the Speculative
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5227) Store Bypass vulnerability and offer a
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5228) firmware based mitigation, this parameter
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5229) indicates how the mitigation should be used:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5230)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5231) force-on: Unconditionally enable mitigation for
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5232) for both kernel and userspace
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5233) force-off: Unconditionally disable mitigation for
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5234) for both kernel and userspace
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5235) kernel: Always enable mitigation in the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5236) kernel, and offer a prctl interface
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5237) to allow userspace to register its
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5238) interest in being mitigated too.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5239)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5240) stack_guard_gap= [MM]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5241) override the default stack gap protection. The value
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5242) is in page units and it defines how many pages prior
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5243) to (for stacks growing down) resp. after (for stacks
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5244) growing up) the main stack are reserved for no other
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5245) mapping. Default value is 256 pages.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5246)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5247) stack_depot_disable= [KNL]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5248) Setting this to true through kernel command line will
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5249) disable the stack depot thereby saving the static memory
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5250) consumed by the stack hash table. By default this is set
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5251) to false.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5252)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5253) stacktrace [FTRACE]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5254) Enabled the stack tracer on boot up.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5255)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5256) stacktrace_filter=[function-list]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5257) [FTRACE] Limit the functions that the stack tracer
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5258) will trace at boot up. function-list is a comma separated
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5259) list of functions. This list can be changed at run
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5260) time by the stack_trace_filter file in the debugfs
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5261) tracing directory. Note, this enables stack tracing
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5262) and the stacktrace above is not needed.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5263)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5264) sti= [PARISC,HW]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5265) Format: <num>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5266) Set the STI (builtin display/keyboard on the HP-PARISC
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5267) machines) console (graphic card) which should be used
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5268) as the initial boot-console.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5269) See also comment in drivers/video/console/sticore.c.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5270)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5271) sti_font= [HW]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5272) See comment in drivers/video/console/sticore.c.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5273)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5274) stifb= [HW]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5275) Format: bpp:<bpp1>[:<bpp2>[:<bpp3>...]]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5276)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5277) sunrpc.min_resvport=
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5278) sunrpc.max_resvport=
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5279) [NFS,SUNRPC]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5280) SunRPC servers often require that client requests
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5281) originate from a privileged port (i.e. a port in the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5282) range 0 < portnr < 1024).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5283) An administrator who wishes to reserve some of these
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5284) ports for other uses may adjust the range that the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5285) kernel's sunrpc client considers to be privileged
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5286) using these two parameters to set the minimum and
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5287) maximum port values.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5288)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5289) sunrpc.svc_rpc_per_connection_limit=
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5290) [NFS,SUNRPC]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5291) Limit the number of requests that the server will
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5292) process in parallel from a single connection.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5293) The default value is 0 (no limit).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5294)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5295) sunrpc.pool_mode=
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5296) [NFS]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5297) Control how the NFS server code allocates CPUs to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5298) service thread pools. Depending on how many NICs
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5299) you have and where their interrupts are bound, this
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5300) option will affect which CPUs will do NFS serving.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5301) Note: this parameter cannot be changed while the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5302) NFS server is running.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5303)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5304) auto the server chooses an appropriate mode
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5305) automatically using heuristics
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5306) global a single global pool contains all CPUs
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5307) percpu one pool for each CPU
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5308) pernode one pool for each NUMA node (equivalent
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5309) to global on non-NUMA machines)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5310)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5311) sunrpc.tcp_slot_table_entries=
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5312) sunrpc.udp_slot_table_entries=
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5313) [NFS,SUNRPC]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5314) Sets the upper limit on the number of simultaneous
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5315) RPC calls that can be sent from the client to a
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5316) server. Increasing these values may allow you to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5317) improve throughput, but will also increase the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5318) amount of memory reserved for use by the client.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5319)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5320) suspend.pm_test_delay=
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5321) [SUSPEND]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5322) Sets the number of seconds to remain in a suspend test
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5323) mode before resuming the system (see
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5324) /sys/power/pm_test). Only available when CONFIG_PM_DEBUG
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5325) is set. Default value is 5.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5326)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5327) svm= [PPC]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5328) Format: { on | off | y | n | 1 | 0 }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5329) This parameter controls use of the Protected
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5330) Execution Facility on pSeries.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5331)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5332) swapaccount=[0|1]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5333) [KNL] Enable accounting of swap in memory resource
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5334) controller if no parameter or 1 is given or disable
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5335) it if 0 is given (See Documentation/admin-guide/cgroup-v1/memory.rst)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5336)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5337) swiotlb= [ARM,IA-64,PPC,MIPS,X86]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5338) Format: { <int> | force | noforce }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5339) <int> -- Number of I/O TLB slabs
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5340) force -- force using of bounce buffers even if they
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5341) wouldn't be automatically used by the kernel
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5342) noforce -- Never use bounce buffers (for debugging)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5343)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5344) switches= [HW,M68k]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5345)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5346) sysctl.*= [KNL]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5347) Set a sysctl parameter, right before loading the init
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5348) process, as if the value was written to the respective
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5349) /proc/sys/... file. Both '.' and '/' are recognized as
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5350) separators. Unrecognized parameters and invalid values
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5351) are reported in the kernel log. Sysctls registered
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5352) later by a loaded module cannot be set this way.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5353) Example: sysctl.vm.swappiness=40
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5354)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5355) sysfs.deprecated=0|1 [KNL]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5356) Enable/disable old style sysfs layout for old udev
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5357) on older distributions. When this option is enabled
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5358) very new udev will not work anymore. When this option
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5359) is disabled (or CONFIG_SYSFS_DEPRECATED not compiled)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5360) in older udev will not work anymore.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5361) Default depends on CONFIG_SYSFS_DEPRECATED_V2 set in
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5362) the kernel configuration.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5363)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5364) sysrq_always_enabled
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5365) [KNL]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5366) Ignore sysrq setting - this boot parameter will
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5367) neutralize any effect of /proc/sys/kernel/sysrq.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5368) Useful for debugging.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5369)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5370) tcpmhash_entries= [KNL,NET]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5371) Set the number of tcp_metrics_hash slots.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5372) Default value is 8192 or 16384 depending on total
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5373) ram pages. This is used to specify the TCP metrics
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5374) cache size. See Documentation/networking/ip-sysctl.rst
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5375) "tcp_no_metrics_save" section for more details.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5376)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5377) tdfx= [HW,DRM]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5378)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5379) test_suspend= [SUSPEND][,N]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5380) Specify "mem" (for Suspend-to-RAM) or "standby" (for
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5381) standby suspend) or "freeze" (for suspend type freeze)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5382) as the system sleep state during system startup with
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5383) the optional capability to repeat N number of times.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5384) The system is woken from this state using a
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5385) wakeup-capable RTC alarm.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5386)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5387) thash_entries= [KNL,NET]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5388) Set number of hash buckets for TCP connection
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5389)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5390) thermal.act= [HW,ACPI]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5391) -1: disable all active trip points in all thermal zones
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5392) <degrees C>: override all lowest active trip points
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5393)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5394) thermal.crt= [HW,ACPI]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5395) -1: disable all critical trip points in all thermal zones
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5396) <degrees C>: override all critical trip points
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5397)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5398) thermal.nocrt= [HW,ACPI]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5399) Set to disable actions on ACPI thermal zone
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5400) critical and hot trip points.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5401)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5402) thermal.off= [HW,ACPI]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5403) 1: disable ACPI thermal control
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5404)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5405) thermal.psv= [HW,ACPI]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5406) -1: disable all passive trip points
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5407) <degrees C>: override all passive trip points to this
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5408) value
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5409)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5410) thermal.tzp= [HW,ACPI]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5411) Specify global default ACPI thermal zone polling rate
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5412) <deci-seconds>: poll all this frequency
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5413) 0: no polling (default)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5414)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5415) threadirqs [KNL]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5416) Force threading of all interrupt handlers except those
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5417) marked explicitly IRQF_NO_THREAD.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5418)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5419) topology= [S390]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5420) Format: {off | on}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5421) Specify if the kernel should make use of the cpu
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5422) topology information if the hardware supports this.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5423) The scheduler will make use of this information and
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5424) e.g. base its process migration decisions on it.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5425) Default is on.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5426)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5427) topology_updates= [KNL, PPC, NUMA]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5428) Format: {off}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5429) Specify if the kernel should ignore (off)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5430) topology updates sent by the hypervisor to this
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5431) LPAR.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5432)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5433) torture.disable_onoff_at_boot= [KNL]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5434) Prevent the CPU-hotplug component of torturing
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5435) until after init has spawned.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5436)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5437) torture.ftrace_dump_at_shutdown= [KNL]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5438) Dump the ftrace buffer at torture-test shutdown,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5439) even if there were no errors. This can be a
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5440) very costly operation when many torture tests
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5441) are running concurrently, especially on systems
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5442) with rotating-rust storage.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5443)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5444) tp720= [HW,PS2]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5445)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5446) tpm_suspend_pcr=[HW,TPM]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5447) Format: integer pcr id
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5448) Specify that at suspend time, the tpm driver
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5449) should extend the specified pcr with zeros,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5450) as a workaround for some chips which fail to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5451) flush the last written pcr on TPM_SaveState.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5452) This will guarantee that all the other pcrs
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5453) are saved.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5454)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5455) trace_buf_size=nn[KMG]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5456) [FTRACE] will set tracing buffer size on each cpu.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5457)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5458) trace_event=[event-list]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5459) [FTRACE] Set and start specified trace events in order
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5460) to facilitate early boot debugging. The event-list is a
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5461) comma separated list of trace events to enable. See
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5462) also Documentation/trace/events.rst
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5463)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5464) trace_options=[option-list]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5465) [FTRACE] Enable or disable tracer options at boot.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5466) The option-list is a comma delimited list of options
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5467) that can be enabled or disabled just as if you were
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5468) to echo the option name into
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5469)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5470) /sys/kernel/debug/tracing/trace_options
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5471)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5472) For example, to enable stacktrace option (to dump the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5473) stack trace of each event), add to the command line:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5474)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5475) trace_options=stacktrace
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5476)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5477) See also Documentation/trace/ftrace.rst "trace options"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5478) section.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5479)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5480) tp_printk[FTRACE]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5481) Have the tracepoints sent to printk as well as the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5482) tracing ring buffer. This is useful for early boot up
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5483) where the system hangs or reboots and does not give the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5484) option for reading the tracing buffer or performing a
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5485) ftrace_dump_on_oops.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5486)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5487) To turn off having tracepoints sent to printk,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5488) echo 0 > /proc/sys/kernel/tracepoint_printk
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5489) Note, echoing 1 into this file without the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5490) tracepoint_printk kernel cmdline option has no effect.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5491)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5492) ** CAUTION **
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5493)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5494) Having tracepoints sent to printk() and activating high
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5495) frequency tracepoints such as irq or sched, can cause
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5496) the system to live lock.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5497)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5498) traceoff_on_warning
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5499) [FTRACE] enable this option to disable tracing when a
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5500) warning is hit. This turns off "tracing_on". Tracing can
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5501) be enabled again by echoing '1' into the "tracing_on"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5502) file located in /sys/kernel/debug/tracing/
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5503)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5504) This option is useful, as it disables the trace before
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5505) the WARNING dump is called, which prevents the trace to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5506) be filled with content caused by the warning output.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5507)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5508) This option can also be set at run time via the sysctl
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5509) option: kernel/traceoff_on_warning
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5510)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5511) transparent_hugepage=
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5512) [KNL]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5513) Format: [always|madvise|never]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5514) Can be used to control the default behavior of the system
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5515) with respect to transparent hugepages.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5516) See Documentation/admin-guide/mm/transhuge.rst
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5517) for more details.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5518)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5519) tsc= Disable clocksource stability checks for TSC.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5520) Format: <string>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5521) [x86] reliable: mark tsc clocksource as reliable, this
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5522) disables clocksource verification at runtime, as well
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5523) as the stability checks done at bootup. Used to enable
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5524) high-resolution timer mode on older hardware, and in
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5525) virtualized environment.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5526) [x86] noirqtime: Do not use TSC to do irq accounting.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5527) Used to run time disable IRQ_TIME_ACCOUNTING on any
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5528) platforms where RDTSC is slow and this accounting
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5529) can add overhead.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5530) [x86] unstable: mark the TSC clocksource as unstable, this
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5531) marks the TSC unconditionally unstable at bootup and
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5532) avoids any further wobbles once the TSC watchdog notices.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5533) [x86] nowatchdog: disable clocksource watchdog. Used
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5534) in situations with strict latency requirements (where
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5535) interruptions from clocksource watchdog are not
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5536) acceptable).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5537)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5538) tsc_early_khz= [X86] Skip early TSC calibration and use the given
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5539) value instead. Useful when the early TSC frequency discovery
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5540) procedure is not reliable, such as on overclocked systems
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5541) with CPUID.16h support and partial CPUID.15h support.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5542) Format: <unsigned int>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5543)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5544) tsx= [X86] Control Transactional Synchronization
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5545) Extensions (TSX) feature in Intel processors that
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5546) support TSX control.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5547)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5548) This parameter controls the TSX feature. The options are:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5549)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5550) on - Enable TSX on the system. Although there are
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5551) mitigations for all known security vulnerabilities,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5552) TSX has been known to be an accelerator for
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5553) several previous speculation-related CVEs, and
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5554) so there may be unknown security risks associated
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5555) with leaving it enabled.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5556)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5557) off - Disable TSX on the system. (Note that this
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5558) option takes effect only on newer CPUs which are
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5559) not vulnerable to MDS, i.e., have
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5560) MSR_IA32_ARCH_CAPABILITIES.MDS_NO=1 and which get
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5561) the new IA32_TSX_CTRL MSR through a microcode
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5562) update. This new MSR allows for the reliable
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5563) deactivation of the TSX functionality.)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5564)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5565) auto - Disable TSX if X86_BUG_TAA is present,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5566) otherwise enable TSX on the system.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5567)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5568) Not specifying this option is equivalent to tsx=off.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5569)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5570) See Documentation/admin-guide/hw-vuln/tsx_async_abort.rst
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5571) for more details.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5572)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5573) tsx_async_abort= [X86,INTEL] Control mitigation for the TSX Async
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5574) Abort (TAA) vulnerability.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5575)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5576) Similar to Micro-architectural Data Sampling (MDS)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5577) certain CPUs that support Transactional
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5578) Synchronization Extensions (TSX) are vulnerable to an
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5579) exploit against CPU internal buffers which can forward
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5580) information to a disclosure gadget under certain
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5581) conditions.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5582)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5583) In vulnerable processors, the speculatively forwarded
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5584) data can be used in a cache side channel attack, to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5585) access data to which the attacker does not have direct
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5586) access.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5587)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5588) This parameter controls the TAA mitigation. The
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5589) options are:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5590)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5591) full - Enable TAA mitigation on vulnerable CPUs
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5592) if TSX is enabled.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5593)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5594) full,nosmt - Enable TAA mitigation and disable SMT on
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5595) vulnerable CPUs. If TSX is disabled, SMT
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5596) is not disabled because CPU is not
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5597) vulnerable to cross-thread TAA attacks.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5598) off - Unconditionally disable TAA mitigation
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5599)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5600) On MDS-affected machines, tsx_async_abort=off can be
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5601) prevented by an active MDS mitigation as both vulnerabilities
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5602) are mitigated with the same mechanism so in order to disable
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5603) this mitigation, you need to specify mds=off too.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5604)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5605) Not specifying this option is equivalent to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5606) tsx_async_abort=full. On CPUs which are MDS affected
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5607) and deploy MDS mitigation, TAA mitigation is not
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5608) required and doesn't provide any additional
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5609) mitigation.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5610)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5611) For details see:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5612) Documentation/admin-guide/hw-vuln/tsx_async_abort.rst
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5613)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5614) turbografx.map[2|3]= [HW,JOY]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5615) TurboGraFX parallel port interface
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5616) Format:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5617) <port#>,<js1>,<js2>,<js3>,<js4>,<js5>,<js6>,<js7>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5618) See also Documentation/input/devices/joystick-parport.rst
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5619)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5620) udbg-immortal [PPC] When debugging early kernel crashes that
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5621) happen after console_init() and before a proper
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5622) console driver takes over, this boot options might
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5623) help "seeing" what's going on.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5624)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5625) uhash_entries= [KNL,NET]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5626) Set number of hash buckets for UDP/UDP-Lite connections
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5627)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5628) uhci-hcd.ignore_oc=
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5629) [USB] Ignore overcurrent events (default N).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5630) Some badly-designed motherboards generate lots of
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5631) bogus events, for ports that aren't wired to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5632) anything. Set this parameter to avoid log spamming.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5633) Note that genuine overcurrent events won't be
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5634) reported either.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5635)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5636) unknown_nmi_panic
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5637) [X86] Cause panic on unknown NMI.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5638)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5639) usbcore.authorized_default=
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5640) [USB] Default USB device authorization:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5641) (default -1 = authorized except for wireless USB,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5642) 0 = not authorized, 1 = authorized, 2 = authorized
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5643) if device connected to internal port)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5644)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5645) usbcore.autosuspend=
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5646) [USB] The autosuspend time delay (in seconds) used
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5647) for newly-detected USB devices (default 2). This
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5648) is the time required before an idle device will be
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5649) autosuspended. Devices for which the delay is set
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5650) to a negative value won't be autosuspended at all.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5651)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5652) usbcore.usbfs_snoop=
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5653) [USB] Set to log all usbfs traffic (default 0 = off).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5654)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5655) usbcore.usbfs_snoop_max=
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5656) [USB] Maximum number of bytes to snoop in each URB
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5657) (default = 65536).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5658)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5659) usbcore.blinkenlights=
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5660) [USB] Set to cycle leds on hubs (default 0 = off).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5661)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5662) usbcore.old_scheme_first=
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5663) [USB] Start with the old device initialization
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5664) scheme (default 0 = off).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5665)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5666) usbcore.usbfs_memory_mb=
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5667) [USB] Memory limit (in MB) for buffers allocated by
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5668) usbfs (default = 16, 0 = max = 2047).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5669)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5670) usbcore.use_both_schemes=
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5671) [USB] Try the other device initialization scheme
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5672) if the first one fails (default 1 = enabled).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5673)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5674) usbcore.initial_descriptor_timeout=
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5675) [USB] Specifies timeout for the initial 64-byte
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5676) USB_REQ_GET_DESCRIPTOR request in milliseconds
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5677) (default 5000 = 5.0 seconds).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5678)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5679) usbcore.nousb [USB] Disable the USB subsystem
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5680)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5681) usbcore.quirks=
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5682) [USB] A list of quirk entries to augment the built-in
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5683) usb core quirk list. List entries are separated by
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5684) commas. Each entry has the form
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5685) VendorID:ProductID:Flags. The IDs are 4-digit hex
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5686) numbers and Flags is a set of letters. Each letter
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5687) will change the built-in quirk; setting it if it is
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5688) clear and clearing it if it is set. The letters have
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5689) the following meanings:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5690) a = USB_QUIRK_STRING_FETCH_255 (string
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5691) descriptors must not be fetched using
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5692) a 255-byte read);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5693) b = USB_QUIRK_RESET_RESUME (device can't resume
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5694) correctly so reset it instead);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5695) c = USB_QUIRK_NO_SET_INTF (device can't handle
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5696) Set-Interface requests);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5697) d = USB_QUIRK_CONFIG_INTF_STRINGS (device can't
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5698) handle its Configuration or Interface
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5699) strings);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5700) e = USB_QUIRK_RESET (device can't be reset
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5701) (e.g morph devices), don't use reset);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5702) f = USB_QUIRK_HONOR_BNUMINTERFACES (device has
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5703) more interface descriptions than the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5704) bNumInterfaces count, and can't handle
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5705) talking to these interfaces);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5706) g = USB_QUIRK_DELAY_INIT (device needs a pause
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5707) during initialization, after we read
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5708) the device descriptor);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5709) h = USB_QUIRK_LINEAR_UFRAME_INTR_BINTERVAL (For
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5710) high speed and super speed interrupt
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5711) endpoints, the USB 2.0 and USB 3.0 spec
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5712) require the interval in microframes (1
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5713) microframe = 125 microseconds) to be
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5714) calculated as interval = 2 ^
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5715) (bInterval-1).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5716) Devices with this quirk report their
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5717) bInterval as the result of this
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5718) calculation instead of the exponent
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5719) variable used in the calculation);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5720) i = USB_QUIRK_DEVICE_QUALIFIER (device can't
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5721) handle device_qualifier descriptor
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5722) requests);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5723) j = USB_QUIRK_IGNORE_REMOTE_WAKEUP (device
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5724) generates spurious wakeup, ignore
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5725) remote wakeup capability);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5726) k = USB_QUIRK_NO_LPM (device can't handle Link
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5727) Power Management);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5728) l = USB_QUIRK_LINEAR_FRAME_INTR_BINTERVAL
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5729) (Device reports its bInterval as linear
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5730) frames instead of the USB 2.0
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5731) calculation);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5732) m = USB_QUIRK_DISCONNECT_SUSPEND (Device needs
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5733) to be disconnected before suspend to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5734) prevent spurious wakeup);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5735) n = USB_QUIRK_DELAY_CTRL_MSG (Device needs a
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5736) pause after every control message);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5737) o = USB_QUIRK_HUB_SLOW_RESET (Hub needs extra
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5738) delay after resetting its port);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5739) Example: quirks=0781:5580:bk,0a5c:5834:gij
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5740)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5741) usbhid.mousepoll=
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5742) [USBHID] The interval which mice are to be polled at.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5743)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5744) usbhid.jspoll=
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5745) [USBHID] The interval which joysticks are to be polled at.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5746)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5747) usbhid.kbpoll=
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5748) [USBHID] The interval which keyboards are to be polled at.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5749)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5750) usb-storage.delay_use=
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5751) [UMS] The delay in seconds before a new device is
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5752) scanned for Logical Units (default 1).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5753)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5754) usb-storage.quirks=
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5755) [UMS] A list of quirks entries to supplement or
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5756) override the built-in unusual_devs list. List
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5757) entries are separated by commas. Each entry has
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5758) the form VID:PID:Flags where VID and PID are Vendor
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5759) and Product ID values (4-digit hex numbers) and
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5760) Flags is a set of characters, each corresponding
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5761) to a common usb-storage quirk flag as follows:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5762) a = SANE_SENSE (collect more than 18 bytes
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5763) of sense data, not on uas);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5764) b = BAD_SENSE (don't collect more than 18
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5765) bytes of sense data, not on uas);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5766) c = FIX_CAPACITY (decrease the reported
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5767) device capacity by one sector);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5768) d = NO_READ_DISC_INFO (don't use
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5769) READ_DISC_INFO command, not on uas);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5770) e = NO_READ_CAPACITY_16 (don't use
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5771) READ_CAPACITY_16 command);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5772) f = NO_REPORT_OPCODES (don't use report opcodes
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5773) command, uas only);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5774) g = MAX_SECTORS_240 (don't transfer more than
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5775) 240 sectors at a time, uas only);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5776) h = CAPACITY_HEURISTICS (decrease the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5777) reported device capacity by one
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5778) sector if the number is odd);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5779) i = IGNORE_DEVICE (don't bind to this
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5780) device);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5781) j = NO_REPORT_LUNS (don't use report luns
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5782) command, uas only);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5783) k = NO_SAME (do not use WRITE_SAME, uas only)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5784) l = NOT_LOCKABLE (don't try to lock and
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5785) unlock ejectable media, not on uas);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5786) m = MAX_SECTORS_64 (don't transfer more
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5787) than 64 sectors = 32 KB at a time,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5788) not on uas);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5789) n = INITIAL_READ10 (force a retry of the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5790) initial READ(10) command, not on uas);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5791) o = CAPACITY_OK (accept the capacity
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5792) reported by the device, not on uas);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5793) p = WRITE_CACHE (the device cache is ON
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5794) by default, not on uas);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5795) r = IGNORE_RESIDUE (the device reports
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5796) bogus residue values, not on uas);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5797) s = SINGLE_LUN (the device has only one
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5798) Logical Unit);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5799) t = NO_ATA_1X (don't allow ATA(12) and ATA(16)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5800) commands, uas only);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5801) u = IGNORE_UAS (don't bind to the uas driver);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5802) w = NO_WP_DETECT (don't test whether the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5803) medium is write-protected).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5804) y = ALWAYS_SYNC (issue a SYNCHRONIZE_CACHE
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5805) even if the device claims no cache,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5806) not on uas)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5807) Example: quirks=0419:aaf5:rl,0421:0433:rc
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5808)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5809) user_debug= [KNL,ARM]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5810) Format: <int>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5811) See arch/arm/Kconfig.debug help text.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5812) 1 - undefined instruction events
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5813) 2 - system calls
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5814) 4 - invalid data aborts
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5815) 8 - SIGSEGV faults
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5816) 16 - SIGBUS faults
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5817) Example: user_debug=31
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5818)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5819) userpte=
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5820) [X86] Flags controlling user PTE allocations.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5821)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5822) nohigh = do not allocate PTE pages in
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5823) HIGHMEM regardless of setting
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5824) of CONFIG_HIGHPTE.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5825)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5826) vdso= [X86,SH]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5827) On X86_32, this is an alias for vdso32=. Otherwise:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5828)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5829) vdso=1: enable VDSO (the default)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5830) vdso=0: disable VDSO mapping
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5831)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5832) vdso32= [X86] Control the 32-bit vDSO
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5833) vdso32=1: enable 32-bit VDSO
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5834) vdso32=0 or vdso32=2: disable 32-bit VDSO
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5835)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5836) See the help text for CONFIG_COMPAT_VDSO for more
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5837) details. If CONFIG_COMPAT_VDSO is set, the default is
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5838) vdso32=0; otherwise, the default is vdso32=1.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5839)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5840) For compatibility with older kernels, vdso32=2 is an
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5841) alias for vdso32=0.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5842)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5843) Try vdso32=0 if you encounter an error that says:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5844) dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed!
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5845)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5846) vector= [IA-64,SMP]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5847) vector=percpu: enable percpu vector domain
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5848)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5849) video= [FB] Frame buffer configuration
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5850) See Documentation/fb/modedb.rst.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5851)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5852) video.brightness_switch_enabled= [0,1]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5853) If set to 1, on receiving an ACPI notify event
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5854) generated by hotkey, video driver will adjust brightness
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5855) level and then send out the event to user space through
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5856) the allocated input device; If set to 0, video driver
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5857) will only send out the event without touching backlight
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5858) brightness level.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5859) default: 1
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5860)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5861) virtio_mmio.device=
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5862) [VMMIO] Memory mapped virtio (platform) device.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5863)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5864) <size>@<baseaddr>:<irq>[:<id>]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5865) where:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5866) <size> := size (can use standard suffixes
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5867) like K, M and G)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5868) <baseaddr> := physical base address
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5869) <irq> := interrupt number (as passed to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5870) request_irq())
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5871) <id> := (optional) platform device id
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5872) example:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5873) virtio_mmio.device=1K@0x100b0000:48:7
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5874)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5875) Can be used multiple times for multiple devices.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5876)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5877) vga= [BOOT,X86-32] Select a particular video mode
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5878) See Documentation/x86/boot.rst and
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5879) Documentation/admin-guide/svga.rst.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5880) Use vga=ask for menu.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5881) This is actually a boot loader parameter; the value is
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5882) passed to the kernel using a special protocol.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5883)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5884) vm_debug[=options] [KNL] Available with CONFIG_DEBUG_VM=y.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5885) May slow down system boot speed, especially when
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5886) enabled on systems with a large amount of memory.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5887) All options are enabled by default, and this
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5888) interface is meant to allow for selectively
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5889) enabling or disabling specific virtual memory
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5890) debugging features.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5891)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5892) Available options are:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5893) P Enable page structure init time poisoning
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5894) - Disable all of the above options
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5895)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5896) vmalloc=nn[KMG] [KNL,BOOT] Forces the vmalloc area to have an exact
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5897) size of <nn>. This can be used to increase the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5898) minimum size (128MB on x86). It can also be used to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5899) decrease the size and leave more room for directly
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5900) mapped kernel RAM.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5901)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5902) vmcp_cma=nn[MG] [KNL,S390]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5903) Sets the memory size reserved for contiguous memory
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5904) allocations for the vmcp device driver.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5905)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5906) vmhalt= [KNL,S390] Perform z/VM CP command after system halt.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5907) Format: <command>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5908)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5909) vmpanic= [KNL,S390] Perform z/VM CP command after kernel panic.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5910) Format: <command>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5911)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5912) vmpoff= [KNL,S390] Perform z/VM CP command after power off.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5913) Format: <command>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5914)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5915) vsyscall= [X86-64]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5916) Controls the behavior of vsyscalls (i.e. calls to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5917) fixed addresses of 0xffffffffff600x00 from legacy
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5918) code). Most statically-linked binaries and older
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5919) versions of glibc use these calls. Because these
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5920) functions are at fixed addresses, they make nice
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5921) targets for exploits that can control RIP.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5922)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5923) emulate [default] Vsyscalls turn into traps and are
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5924) emulated reasonably safely. The vsyscall
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5925) page is readable.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5926)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5927) xonly Vsyscalls turn into traps and are
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5928) emulated reasonably safely. The vsyscall
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5929) page is not readable.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5930)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5931) none Vsyscalls don't work at all. This makes
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5932) them quite hard to use for exploits but
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5933) might break your system.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5934)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5935) vt.color= [VT] Default text color.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5936) Format: 0xYX, X = foreground, Y = background.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5937) Default: 0x07 = light gray on black.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5938)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5939) vt.cur_default= [VT] Default cursor shape.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5940) Format: 0xCCBBAA, where AA, BB, and CC are the same as
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5941) the parameters of the <Esc>[?A;B;Cc escape sequence;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5942) see VGA-softcursor.txt. Default: 2 = underline.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5943)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5944) vt.default_blu= [VT]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5945) Format: <blue0>,<blue1>,<blue2>,...,<blue15>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5946) Change the default blue palette of the console.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5947) This is a 16-member array composed of values
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5948) ranging from 0-255.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5949)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5950) vt.default_grn= [VT]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5951) Format: <green0>,<green1>,<green2>,...,<green15>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5952) Change the default green palette of the console.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5953) This is a 16-member array composed of values
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5954) ranging from 0-255.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5955)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5956) vt.default_red= [VT]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5957) Format: <red0>,<red1>,<red2>,...,<red15>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5958) Change the default red palette of the console.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5959) This is a 16-member array composed of values
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5960) ranging from 0-255.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5961)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5962) vt.default_utf8=
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5963) [VT]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5964) Format=<0|1>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5965) Set system-wide default UTF-8 mode for all tty's.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5966) Default is 1, i.e. UTF-8 mode is enabled for all
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5967) newly opened terminals.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5968)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5969) vt.global_cursor_default=
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5970) [VT]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5971) Format=<-1|0|1>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5972) Set system-wide default for whether a cursor
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5973) is shown on new VTs. Default is -1,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5974) i.e. cursors will be created by default unless
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5975) overridden by individual drivers. 0 will hide
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5976) cursors, 1 will display them.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5977)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5978) vt.italic= [VT] Default color for italic text; 0-15.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5979) Default: 2 = green.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5980)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5981) vt.underline= [VT] Default color for underlined text; 0-15.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5982) Default: 3 = cyan.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5983)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5984) watchdog timers [HW,WDT] For information on watchdog timers,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5985) see Documentation/watchdog/watchdog-parameters.rst
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5986) or other driver-specific files in the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5987) Documentation/watchdog/ directory.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5988)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5989) watchdog_thresh=
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5990) [KNL]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5991) Set the hard lockup detector stall duration
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5992) threshold in seconds. The soft lockup detector
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5993) threshold is set to twice the value. A value of 0
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5994) disables both lockup detectors. Default is 10
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5995) seconds.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5996)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5997) workqueue.watchdog_thresh=
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5998) If CONFIG_WQ_WATCHDOG is configured, workqueue can
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5999) warn stall conditions and dump internal state to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6000) help debugging. 0 disables workqueue stall
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6001) detection; otherwise, it's the stall threshold
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6002) duration in seconds. The default value is 30 and
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6003) it can be updated at runtime by writing to the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6004) corresponding sysfs file.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6005)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6006) workqueue.disable_numa
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6007) By default, all work items queued to unbound
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6008) workqueues are affine to the NUMA nodes they're
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6009) issued on, which results in better behavior in
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6010) general. If NUMA affinity needs to be disabled for
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6011) whatever reason, this option can be used. Note
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6012) that this also can be controlled per-workqueue for
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6013) workqueues visible under /sys/bus/workqueue/.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6014)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6015) workqueue.power_efficient
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6016) Per-cpu workqueues are generally preferred because
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6017) they show better performance thanks to cache
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6018) locality; unfortunately, per-cpu workqueues tend to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6019) be more power hungry than unbound workqueues.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6020)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6021) Enabling this makes the per-cpu workqueues which
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6022) were observed to contribute significantly to power
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6023) consumption unbound, leading to measurably lower
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6024) power usage at the cost of small performance
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6025) overhead.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6026)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6027) The default value of this parameter is determined by
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6028) the config option CONFIG_WQ_POWER_EFFICIENT_DEFAULT.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6029)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6030) workqueue.debug_force_rr_cpu
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6031) Workqueue used to implicitly guarantee that work
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6032) items queued without explicit CPU specified are put
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6033) on the local CPU. This guarantee is no longer true
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6034) and while local CPU is still preferred work items
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6035) may be put on foreign CPUs. This debug option
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6036) forces round-robin CPU selection to flush out
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6037) usages which depend on the now broken guarantee.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6038) When enabled, memory and cache locality will be
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6039) impacted.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6040)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6041) x2apic_phys [X86-64,APIC] Use x2apic physical mode instead of
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6042) default x2apic cluster mode on platforms
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6043) supporting x2apic.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6044)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6045) x86_intel_mid_timer= [X86-32,APBT]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6046) Choose timer option for x86 Intel MID platform.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6047) Two valid options are apbt timer only and lapic timer
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6048) plus one apbt timer for broadcast timer.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6049) x86_intel_mid_timer=apbt_only | lapic_and_apbt
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6050)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6051) xen_512gb_limit [KNL,X86-64,XEN]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6052) Restricts the kernel running paravirtualized under Xen
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6053) to use only up to 512 GB of RAM. The reason to do so is
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6054) crash analysis tools and Xen tools for doing domain
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6055) save/restore/migration must be enabled to handle larger
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6056) domains.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6057)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6058) xen_emul_unplug= [HW,X86,XEN]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6059) Unplug Xen emulated devices
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6060) Format: [unplug0,][unplug1]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6061) ide-disks -- unplug primary master IDE devices
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6062) aux-ide-disks -- unplug non-primary-master IDE devices
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6063) nics -- unplug network devices
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6064) all -- unplug all emulated devices (NICs and IDE disks)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6065) unnecessary -- unplugging emulated devices is
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6066) unnecessary even if the host did not respond to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6067) the unplug protocol
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6068) never -- do not unplug even if version check succeeds
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6069)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6070) xen_legacy_crash [X86,XEN]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6071) Crash from Xen panic notifier, without executing late
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6072) panic() code such as dumping handler.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6073)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6074) xen_nopvspin [X86,XEN]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6075) Disables the qspinlock slowpath using Xen PV optimizations.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6076) This parameter is obsoleted by "nopvspin" parameter, which
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6077) has equivalent effect for XEN platform.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6078)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6079) xen_nopv [X86]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6080) Disables the PV optimizations forcing the HVM guest to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6081) run as generic HVM guest with no PV drivers.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6082) This option is obsoleted by the "nopv" option, which
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6083) has equivalent effect for XEN platform.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6084)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6085) xen_no_vector_callback
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6086) [KNL,X86,XEN] Disable the vector callback for Xen
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6087) event channel interrupts.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6088)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6089) xen_scrub_pages= [XEN]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6090) Boolean option to control scrubbing pages before giving them back
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6091) to Xen, for use by other domains. Can be also changed at runtime
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6092) with /sys/devices/system/xen_memory/xen_memory0/scrub_pages.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6093) Default value controlled with CONFIG_XEN_SCRUB_PAGES_DEFAULT.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6094)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6095) xen_timer_slop= [X86-64,XEN]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6096) Set the timer slop (in nanoseconds) for the virtual Xen
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6097) timers (default is 100000). This adjusts the minimum
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6098) delta of virtualized Xen timers, where lower values
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6099) improve timer resolution at the expense of processing
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6100) more timer interrupts.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6101)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6102) xen.balloon_boot_timeout= [XEN]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6103) The time (in seconds) to wait before giving up to boot
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6104) in case initial ballooning fails to free enough memory.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6105) Applies only when running as HVM or PVH guest and
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6106) started with less memory configured than allowed at
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6107) max. Default is 180.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6108)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6109) xen.event_eoi_delay= [XEN]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6110) How long to delay EOI handling in case of event
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6111) storms (jiffies). Default is 10.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6112)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6113) xen.event_loop_timeout= [XEN]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6114) After which time (jiffies) the event handling loop
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6115) should start to delay EOI handling. Default is 2.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6116)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6117) xen.fifo_events= [XEN]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6118) Boolean parameter to disable using fifo event handling
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6119) even if available. Normally fifo event handling is
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6120) preferred over the 2-level event handling, as it is
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6121) fairer and the number of possible event channels is
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6122) much higher. Default is on (use fifo events).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6123)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6124) nopv= [X86,XEN,KVM,HYPER_V,VMWARE]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6125) Disables the PV optimizations forcing the guest to run
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6126) as generic guest with no PV drivers. Currently support
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6127) XEN HVM, KVM, HYPER_V and VMWARE guest.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6128)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6129) nopvspin [X86,XEN,KVM]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6130) Disables the qspinlock slow path using PV optimizations
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6131) which allow the hypervisor to 'idle' the guest on lock
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6132) contention.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6133)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6134) xirc2ps_cs= [NET,PCMCIA]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6135) Format:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6136) <irq>,<irq_mask>,<io>,<full_duplex>,<do_sound>,<lockup_hack>[,<irq2>[,<irq3>[,<irq4>]]]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6137)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6138) xive= [PPC]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6139) By default on POWER9 and above, the kernel will
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6140) natively use the XIVE interrupt controller. This option
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6141) allows the fallback firmware mode to be used:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6142)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6143) off Fallback to firmware control of XIVE interrupt
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6144) controller on both pseries and powernv
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6145) platforms. Only useful on POWER9 and above.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6146)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6147) xhci-hcd.quirks [USB,KNL]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6148) A hex value specifying bitmask with supplemental xhci
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6149) host controller quirks. Meaning of each bit can be
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6150) consulted in header drivers/usb/host/xhci.h.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6151)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6152) xmon [PPC]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6153) Format: { early | on | rw | ro | off }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6154) Controls if xmon debugger is enabled. Default is off.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6155) Passing only "xmon" is equivalent to "xmon=early".
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6156) early Call xmon as early as possible on boot; xmon
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6157) debugger is called from setup_arch().
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6158) on xmon debugger hooks will be installed so xmon
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6159) is only called on a kernel crash. Default mode,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6160) i.e. either "ro" or "rw" mode, is controlled
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6161) with CONFIG_XMON_DEFAULT_RO_MODE.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6162) rw xmon debugger hooks will be installed so xmon
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6163) is called only on a kernel crash, mode is write,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6164) meaning SPR registers, memory and, other data
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6165) can be written using xmon commands.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6166) ro same as "rw" option above but SPR registers,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6167) memory, and other data can't be written using
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6168) xmon commands.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6169) off xmon is disabled.
Orange Pi5 kernel
Deprecated Linux kernel 5.10.110 for OrangePi 5/5B/5+ boards
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