Date: Thu, 7 Sep 2017 09:43:30 -0500 (CDT)
From: Christopher Lameter <cl@linux.com>
To: David Rientjes <rientjes@google.com>
cc: Roman Gushchin <guro@fb.com>, nzimmer@sgi.com, holt@sgi.com,
        Michal Hocko <mhocko@kernel.org>, linux-mm@kvack.org,
        Vladimir Davydov <vdavydov.dev@gmail.com>,
        Johannes Weiner <hannes@cmpxchg.org>,
        Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>,
        Andrew Morton <akpm@linux-foundation.org>, Tejun Heo <tj@kernel.org>,
        kernel-team@fb.com, cgroups@vger.kernel.org, linux-doc@vger.kernel.org,
        linux-kernel@vger.kernel.org, sivanich@sgi.com
Subject: Re: [v7 5/5] mm, oom: cgroup v2 mount option to disable cgroup-aware
 OOM killer
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On Wed, 6 Sep 2017, David Rientjes wrote:

> > The oom_kill_allocating_task sysctl which causes the OOM killer
> > to simple kill the allocating task is useless. Killing the random
> > task is not the best idea.
> >
> > Nobody likes it, and hopefully nobody uses it.
> > We want to completely deprecate it at some point.
> >
>
> SGI required it when it was introduced simply to avoid the very expensive
> tasklist scan.  Adding Christoph Lameter to the cc since he was involved
> back then.

Really? From what I know and worked on way back when: The reason was to be
able to contain the affected application in a cpuset. Multiple apps may
have been running in multiple cpusets on a large NUMA machine and the OOM
condition in one cpuset should not affect the other. It also helped to
isolate the application behavior causing the oom in numerous cases.

Doesnt this requirement transfer to cgroups in the same way?

Left SGI in 2008 so adding Dimitri who may know about the current
situation. Robin Holt also left SGI as far as I know.