Orange Pi5 kernel

^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  1) # SPDX-License-Identifier: GPL-2.0
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  2) config ZRAM
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  3) 	tristate "Compressed RAM block device support"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  4) 	depends on BLOCK && SYSFS && ZSMALLOC && CRYPTO
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  5) 	select CRYPTO_LZO
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  6) 	help
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  7) 	  Creates virtual block devices called /dev/zramX (X = 0, 1, ...).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  8) 	  Pages written to these disks are compressed and stored in memory
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  9) 	  itself. These disks allow very fast I/O and compression provides
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 10) 	  good amounts of memory savings.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 11) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 12) 	  It has several use cases, for example: /tmp storage, use as swap
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 13) 	  disks and maybe many more.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 14) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 15) 	  See Documentation/admin-guide/blockdev/zram.rst for more information.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 16) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 17) config ZRAM_WRITEBACK
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 18)        bool "Write back incompressible or idle page to backing device"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 19)        depends on ZRAM
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 20)        help
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 21) 	 With incompressible page, there is no memory saving to keep it
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 22) 	 in memory. Instead, write it out to backing device.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 23) 	 For this feature, admin should set up backing device via
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 24) 	 /sys/block/zramX/backing_dev.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 25) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 26) 	 With /sys/block/zramX/{idle,writeback}, application could ask
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 27) 	 idle page's writeback to the backing device to save in memory.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 28) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 29) 	 See Documentation/admin-guide/blockdev/zram.rst for more information.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 30) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 31) config ZRAM_MEMORY_TRACKING
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 32) 	bool "Track zRam block status"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 33) 	depends on ZRAM && DEBUG_FS
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 34) 	help
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 35) 	  With this feature, admin can track the state of allocated blocks
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 36) 	  of zRAM. Admin could see the information via
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 37) 	  /sys/kernel/debug/zram/zramX/block_state.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 38) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 39) 	  See Documentation/admin-guide/blockdev/zram.rst for more information.