Re: [PATCH 1/2] mm, oom: do not rely on TIF_MEMDIE for memory reserves access

From: Michal Hocko <mhocko@kernel.org>
To: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: akpm@linux-foundation.org, rientjes@google.com,
	hannes@cmpxchg.org, guro@fb.com, linux-mm@kvack.org,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH 1/2] mm, oom: do not rely on TIF_MEMDIE for memory reserves access
Date: Thu, 3 Aug 2017 10:21:04 +0200	[thread overview]
Message-ID: <20170803082104.GE12521@dhcp22.suse.cz> (raw)
In-Reply-To: <201708031703.HGC35950.LSJFOHQFtFMOVO@I-love.SAKURA.ne.jp>

On Thu 03-08-17 17:03:20, Tetsuo Handa wrote:
> Michal Hocko wrote:
> > Look, I really appreciate your sentiment for for nommu platform but with
> > an absolute lack of _any_ oom reports on that platform that I am aware
> > of nor any reports about lockups during oom I am less than thrilled to
> > add a code to fix a problem which even might not exist. Nommu is usually
> > very special with a very specific workload running (e.g. no overcommit)
> > so I strongly suspect that any OOM theories are highly academic.
> 
> If you believe that there is really no oom report, get rid of the OOM
> killer completely.

I am not an user or even an owner of such a platform. As I've said all I
care about is to not regress for those guys and I believe that the patch
doesn't change nommu behavior in any risky way. If yes, point them out
and I will try to address them.

> > All I do care about is to not regress nommu as much as possible. So can
> > we get back to the proposed patch and updates I have done to address
> > your review feedback please?
> 
> No unless we get rid of the OOM killer if CONFIG_MMU=n.

Are you saying that you are going to nack the patch based on this
reasoning? This is just ridiculous.

-- 
Michal Hocko
SUSE Labs