Orange Pi5 kernel

^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  1) ==================
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  2) Control Groupstats
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  3) ==================
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  4) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  5) Control Groupstats is inspired by the discussion at
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  6) http://lkml.org/lkml/2007/4/11/187 and implements per cgroup statistics as
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  7) suggested by Andrew Morton in http://lkml.org/lkml/2007/4/11/263.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  8) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  9) Per cgroup statistics infrastructure re-uses code from the taskstats
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 10) interface. A new set of cgroup operations are registered with commands
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 11) and attributes specific to cgroups. It should be very easy to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 12) extend per cgroup statistics, by adding members to the cgroupstats
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 13) structure.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 14) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 15) The current model for cgroupstats is a pull, a push model (to post
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 16) statistics on interesting events), should be very easy to add. Currently
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 17) user space requests for statistics by passing the cgroup path.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 18) Statistics about the state of all the tasks in the cgroup is returned to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 19) user space.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 20) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 21) NOTE: We currently rely on delay accounting for extracting information
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 22) about tasks blocked on I/O. If CONFIG_TASK_DELAY_ACCT is disabled, this
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 23) information will not be available.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 24) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 25) To extract cgroup statistics a utility very similar to getdelays.c
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 26) has been developed, the sample output of the utility is shown below::
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 27) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 28)   ~/balbir/cgroupstats # ./getdelays  -C "/sys/fs/cgroup/a"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 29)   sleeping 1, blocked 0, running 1, stopped 0, uninterruptible 0
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 30)   ~/balbir/cgroupstats # ./getdelays  -C "/sys/fs/cgroup"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 31)   sleeping 155, blocked 0, running 1, stopped 0, uninterruptible 2