android_kernel_motorola_sm6375/include
Repository files (latest commit first)
Filename Latest commit message Latest commit date
Roman Gushchin 422580c3ce mm/oom_kill.c: add tracepoints for oom reaper-related events
During the debugging of the problem described in
https://lkml.org/lkml/2017/5/17/542 and fixed by Tetsuo Handa in
https://lkml.org/lkml/2017/5/19/383 , I've found that the existing debug
output is not really useful to understand issues related to the oom
reaper.

So, I assume, that adding some tracepoints might help with debugging of
similar issues.

Trace the following events:
 1) a process is marked as an oom victim,
 2) a process is added to the oom reaper list,
 3) the oom reaper starts reaping process's mm,
 4) the oom reaper finished reaping,
 5) the oom reaper skips reaping.

How it works in practice? Below is an example which show how the problem
mentioned above can be found: one process is added twice to the
oom_reaper list:

  $ cd /sys/kernel/debug/tracing
  $ echo "oom:mark_victim" > set_event
  $ echo "oom:wake_reaper" >> set_event
  $ echo "oom:skip_task_reaping" >> set_event
  $ echo "oom:start_task_reaping" >> set_event
  $ echo "oom:finish_task_reaping" >> set_event
  $ cat trace_pipe
          allocate-502   [001] ....    91.836405: mark_victim: pid=502
          allocate-502   [001] .N..    91.837356: wake_reaper: pid=502
          allocate-502   [000] .N..    91.871149: wake_reaper: pid=502
        oom_reaper-23    [000] ....    91.871177: start_task_reaping: pid=502
        oom_reaper-23    [000] .N..    91.879511: finish_task_reaping: pid=502
        oom_reaper-23    [000] ....    91.879580: skip_task_reaping: pid=502

Link: http://lkml.kernel.org/r/20170530185231.GA13412@castle
Signed-off-by: Roman Gushchin <guro@fb.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-07-10 16:32:32 -07:00
..
acpi
asm-generic powerpc updates for 4.13 2017-07-07 13:55:45 -07:00
clocksource
crypto
drm main drm pull for v4.13 2017-07-09 18:48:37 -07:00
dt-bindings This is the bulk of GPIO changes for the v4.13 series: 2017-07-07 12:40:27 -07:00
keys
kvm
linux mm: unify new_node_page and alloc_migrate_target 2017-07-10 16:32:31 -07:00
math-emu
media main drm pull for v4.13 2017-07-09 18:48:37 -07:00
memory
misc
net Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2017-07-08 12:01:22 -07:00
pcmcia
ras
rdma Fixes #3 for 4.12-rc 2017-07-06 11:45:08 -07:00
rxrpc
scsi SCSI misc on 20170704 2017-07-06 12:10:33 -07:00
soc
sound
target
trace mm/oom_kill.c: add tracepoints for oom reaper-related events 2017-07-10 16:32:32 -07:00
uapi main drm pull for v4.13 2017-07-09 18:48:37 -07:00
video
xen This is the first pull request for the new dma-mapping subsystem 2017-07-06 19:20:54 -07:00