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Date: Tue, 30 Jan 2018 12:30:17 -0500
From: Johannes Weiner <hannes@cmpxchg.org>
To: Michal Hocko <mhocko@kernel.org>
Cc: Roman Gushchin <guro@fb.com>, Tejun Heo <tj@kernel.org>,
        Andrew Morton <akpm@linux-foundation.org>,
        David Rientjes <rientjes@google.com>,
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        linux-kernel@vger.kernel.org, linux-mm@kvack.org
Subject: Re: [patch -mm v2 2/3] mm, memcg: replace cgroup aware oom killer
 mount option with tunable
Message-ID: <20180130173017.GA24827@cmpxchg.org>
References: <20180126143950.719912507bd993d92188877f@linux-foundation.org>
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On Tue, Jan 30, 2018 at 01:20:11PM +0100, Michal Hocko wrote:
> From 361275a05ad7026b8f721f8aa756a4975a2c42b1 Mon Sep 17 00:00:00 2001
> From: Michal Hocko <mhocko@suse.com>
> Date: Tue, 30 Jan 2018 09:54:15 +0100
> Subject: [PATCH] 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.
> 
> Acked-by: Roman Gushchin <guro@fb.com>
> Signed-off-by: Michal Hocko <mhocko@suse.com>

Acked-by: Johannes Weiner <hannes@cmpxchg.org>