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Date: Thu, 12 Dec 2013 17:32:22 +0100
From: Michal Hocko <mhocko@suse.cz>
To: Tejun Heo <tj@kernel.org>
Cc: Tim Hockin <thockin@hockin.org>, David Rientjes <rientjes@google.com>,
        Johannes Weiner <hannes@cmpxchg.org>,
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Subject: Re: [patch 7/8] mm, memcg: allow processes handling oom
 notifications to access reserves
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On Thu 12-12-13 09:21:56, Tejun Heo wrote:
[...]
> There'd still be all the bells and whistles to configure and monitor
> system-level OOM and if there's justified need for improvements, we
> surely can and should do that;

You weren't on the CC of the original thread which has started here
https://lkml.org/lkml/2013/11/19/191. And the original request for
discussion was more about user defined _policies_ for the global
OOM rather than user space global OOM handler. I feel that there
are usacases where the current "kill a single task based on some
calculations" is far from optimal which leads to hacks which try to cope
with after oom condition somehow gracefully.

I do agree with you that pulling oom handling sounds too dangerous
even with all the code that it would need and I feel we should go a
different path than (ab)using memcg.oom_control interface for that.
I still think we need to have a way to tell the global OOM killer what
to do.

[...]
-- 
Michal Hocko
SUSE Labs