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authorMichal Hocko <mhocko@suse.com>2018-08-17 15:49:10 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2018-08-17 16:20:32 -0700
commita195d3f5b74f3f45a6742f9063b5e95a2522b46d (patch)
tree3de24cc97571ff50527318393f6d033c2a7de766 /mm/oom_kill.c
parent40d18ebffb3974272a920c41f2d74431152cae98 (diff)
downloadlinux-a195d3f5b74f3f45a6742f9063b5e95a2522b46d.tar.bz2
mm/oom_kill.c: document oom_lock
Add comments describing oom_lock's scope. Requested-by: David Rientjes <rientjes@google.com> Link: http://lkml.kernel.org/r/20180711120121.25635-1-mhocko@kernel.org Signed-off-by: Michal Hocko <mhocko@suse.com> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Cc: David Rientjes <rientjes@google.com> Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/oom_kill.c')
-rw-r--r--mm/oom_kill.c8
1 files changed, 8 insertions, 0 deletions
diff --git a/mm/oom_kill.c b/mm/oom_kill.c
index cd6520f7553d..412f43453a68 100644
--- a/mm/oom_kill.c
+++ b/mm/oom_kill.c
@@ -53,6 +53,14 @@ int sysctl_panic_on_oom;
int sysctl_oom_kill_allocating_task;
int sysctl_oom_dump_tasks = 1;
+/*
+ * Serializes oom killer invocations (out_of_memory()) from all contexts to
+ * prevent from over eager oom killing (e.g. when the oom killer is invoked
+ * from different domains).
+ *
+ * oom_killer_disable() relies on this lock to stabilize oom_killer_disabled
+ * and mark_oom_victim
+ */
DEFINE_MUTEX(oom_lock);
#ifdef CONFIG_NUMA