mm/oom_kill: count global and memory cgroup oom kills
Show count of oom killer invocations in /proc/vmstat and count of
processes killed in memory cgroup in knob "memory.events" (in
memory.oom_control for v1 cgroup).
Also describe difference between "oom" and "oom_kill" in memory cgroup
documentation. Currently oom in memory cgroup kills tasks iff shortage
has happened inside page fault.
These counters helps in monitoring oom kills - for now the only way is
grepping for magic words in kernel log.
[akpm@linux-foundation.org: fix for mem_cgroup_count_vm_event() rename]
[akpm@linux-foundation.org: fix comment, per Konstantin]
Link: http://lkml.kernel.org/r/149570810989.203600.9492483715840752937.stgit@buzz
Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: Roman Guschin <guroan@gmail.com>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h
index b2a5b1c..72d0853 100644
--- a/include/linux/memcontrol.h
+++ b/include/linux/memcontrol.h
@@ -582,8 +582,11 @@ static inline void count_memcg_event_mm(struct mm_struct *mm,
rcu_read_lock();
memcg = mem_cgroup_from_task(rcu_dereference(mm->owner));
- if (likely(memcg))
+ if (likely(memcg)) {
this_cpu_inc(memcg->stat->events[idx]);
+ if (idx == OOM_KILL)
+ cgroup_file_notify(&memcg->events_file);
+ }
rcu_read_unlock();
}
#ifdef CONFIG_TRANSPARENT_HUGEPAGE