tree ee11183c5789dd2f74bf7aa79b376639d6a506e0
parent b4b946274af6393f88ef6a90a23f4b9d1df30f66
author Michal Hocko <mhocko@suse.com> 1528449472 +0200
committer Michal Hocko <mhocko@suse.com> 1530696595 +0200

oom, memcg: clarify root memcg oom accounting

David Rientjes has pointed out that the current way how the root memcg is
accounted for the cgroup aware OOM killer is undocumented.  Unlike regular
cgroups there is no accounting going on in the root memcg (mostly for
performance reasons).  Therefore we are suming up oom_badness of its
tasks.  This might result in an over accounting because of the
oom_score_adj setting.  Document this for now.

Link: http://lkml.kernel.org/r/20180130122011.GB21609@dhcp22.suse.cz
[akpm: tweak text, fix typo]
Signed-off-by: Michal Hocko <mhocko@suse.com>
Acked-by: Roman Gushchin <guro@fb.com>
Acked-by: Tejun Heo <tj@kernel.org>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>