From mboxrd@z Thu Jan  1 00:00:00 1970
From: Tejun Heo <tj-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>
Subject: Re: [patch -mm v2 2/3] mm, memcg: replace cgroup aware oom killer
 mount option with tunable
Date: Mon, 29 Jan 2018 11:11:39 -0800
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To: Michal Hocko <mhocko-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>
Cc: Andrew Morton <akpm-de/tnXTf+JLsfHDXvbKv3WD2FQJk+8+b@public.gmane.org>, David Rientjes <rientjes-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org>, Roman Gushchin <guro-b10kYP2dOMg@public.gmane.org>, Vladimir Davydov <vdavydov.dev-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>, Johannes Weiner <hannes-druUgvl0LCNAfugRpC6u6w@public.gmane.org>, Tetsuo Handa <penguin-kernel-1yMVhJb1mP/7nzcFbJAaVXf5DAMn2ifp@public.gmane.org>, kernel-team-b10kYP2dOMg@public.gmane.org, cgroups-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-doc-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-mm-Bw31MaZKKs3YtjvyW6yDsg@public.gmane.org

Hello, Michal.

On Mon, Jan 29, 2018 at 11:46:57AM +0100, Michal Hocko wrote:
> @@ -1292,7 +1292,11 @@ the memory controller considers only cgroups belonging to the sub-tree
>  of the OOM'ing cgroup.
>  
>  The root cgroup is treated as a leaf memory cgroup, so it's compared
> -with other leaf memory cgroups and cgroups with oom_group option set.
> +with other leaf memory cgroups and cgroups with oom_group option
> +set. Due to internal implementation restrictions the size of the root
> +cgroup is a cumulative sum of oom_badness of all its tasks (in other
> +words oom_score_adj of each task is obeyed). This might change in the
> +future.

Thanks, we can definitely use more documentation.  However, it's a bit
difficult to follow.  Maybe expand it to a separate paragraph on the
current behavior with a clear warning that the default OOM heuristics
is subject to changes?

Thanks.

-- 
tejun