From: Michal Hocko <mhocko@kernel.org>
To: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
Cc: Shakeel Butt <shakeelb@google.com>, linux-mm@kvack.org
Subject: Re: [PATCH] mm: mempolicy: don't select exited threads as OOM victims
Date: Wed, 3 Jul 2019 09:06:32 +0200 [thread overview]
Message-ID: <20190703070632.GL978@dhcp22.suse.cz> (raw)
In-Reply-To: <0c26d2d5-19b1-7915-e47e-60d86a946d09@i-love.sakura.ne.jp>
On Wed 03-07-19 06:26:55, Tetsuo Handa wrote:
> On 2019/07/02 22:51, Michal Hocko wrote:
> >>> I do not see any strong reason to keep the current ordering. OOM victim
> >>> check is trivial so it shouldn't add a visible overhead for few
> >>> unkillable tasks that we might encounter.
> >>>
> >>
> >> Yes if we can tolerate that there can be only one OOM victim for !memcg OOM events
> >> (because an OOM victim in a different OOM context will hit "goto abort;" path).
> >
> > You are right. Considering that we now have a guarantee of a forward
> > progress then this should be tolerateable (a victim in a disjoint
> > numaset will go away and other one can go ahead and trigger its own
> > OOM).
>
> But it might take very long period before MMF_OOM_SKIP is set by the OOM reaper
> or exit_mmap(). Until MMF_OOM_SKIP is set, OOM events from disjoint numaset can't
> make forward progress.
If that is a concern then I would stick with the current status quo
until we see the issue to be reported by real workloads.
--
Michal Hocko
SUSE Labs
prev parent reply other threads:[~2019-07-03 7:06 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-06-29 11:24 [PATCH] mm: mempolicy: don't select exited threads as OOM victims Tetsuo Handa
2019-07-01 11:17 ` Michal Hocko
2019-07-01 13:04 ` Tetsuo Handa
2019-07-01 13:17 ` Michal Hocko
2019-07-01 13:38 ` Tetsuo Handa
2019-07-01 13:48 ` Michal Hocko
2019-07-01 13:56 ` Tetsuo Handa
2019-07-01 14:04 ` Michal Hocko
2019-07-01 14:16 ` Michal Hocko
2019-07-02 13:19 ` Tetsuo Handa
2019-07-02 13:51 ` Michal Hocko
2019-07-02 21:26 ` Tetsuo Handa
2019-07-03 7:06 ` Michal Hocko [this message]
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