From: Michal Hocko <mhocko@kernel.org>
To: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: akpm@linux-foundation.org, rientjes@google.com, mgorman@suse.de,
oleg@redhat.com, torvalds@linux-foundation.org, hughd@google.com,
andrea@kernel.org, riel@redhat.com, linux-mm@kvack.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH 2/6] mm,oom: don't abort on exiting processes when selecting a victim.
Date: Wed, 17 Feb 2016 15:00:06 +0100 [thread overview]
Message-ID: <20160217140006.GM29196@dhcp22.suse.cz> (raw)
In-Reply-To: <201602172207.GAG52105.FOtMJOFQOVSFHL@I-love.SAKURA.ne.jp>
On Wed 17-02-16 22:07:31, Tetsuo Handa wrote:
> Michal Hocko wrote:
> > On Wed 17-02-16 19:30:41, Tetsuo Handa wrote:
> > > >From 22bd036766e70f0df38c38f3ecc226e857d20faf Mon Sep 17 00:00:00 2001
> > > From: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
> > > Date: Wed, 17 Feb 2016 16:30:59 +0900
> > > Subject: [PATCH 2/6] mm,oom: don't abort on exiting processes when selecting a victim.
> > >
> > > Currently, oom_scan_process_thread() returns OOM_SCAN_ABORT when there
> > > is a thread which is exiting. But it is possible that that thread is
> > > blocked at down_read(&mm->mmap_sem) in exit_mm() called from do_exit()
> > > whereas one of threads sharing that memory is doing a GFP_KERNEL
> > > allocation between down_write(&mm->mmap_sem) and up_write(&mm->mmap_sem)
> > > (e.g. mmap()). Under such situation, the OOM killer does not choose a
> > > victim, which results in silent OOM livelock problem.
> >
> > Again, such a thread/task will have fatal_signal_pending and so have
> > access to memory reserves. So the text is slightly misleading imho.
> > Sure if the memory reserves are depleted then we will not move on but
> > then it is not clear whether the current patch helps either.
>
> I don't think so.
> Please see http://lkml.kernel.org/r/201602151958.HCJ48972.FFOFOLMHSQVJtO@I-love.SAKURA.ne.jp .
I have missed this one. Reading...
Hmm, so you are not referring to OOM killed task but naturally exiting
thread which is racing with the OOM killer. I guess you have a point
there! Could you update the changelog with the above example and repost
please?
Thanks!
--
Michal Hocko
SUSE Labs
next prev parent reply other threads:[~2016-02-17 14:00 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-02-17 10:28 [PATCH 0/6] preparation for merging the OOM reaper Tetsuo Handa
2016-02-17 10:29 ` [PATCH 1/6] mm,oom: exclude TIF_MEMDIE processes from candidates Tetsuo Handa
2016-02-17 12:41 ` Michal Hocko
2016-02-17 16:40 ` Tetsuo Handa
2016-02-17 17:33 ` Michal Hocko
2016-02-17 20:55 ` Tetsuo Handa
2016-02-17 10:30 ` [PATCH 2/6] mm,oom: don't abort on exiting processes when selecting a victim Tetsuo Handa
2016-02-17 12:54 ` Michal Hocko
2016-02-17 13:07 ` Tetsuo Handa
2016-02-17 14:00 ` Michal Hocko [this message]
2016-02-17 14:39 ` Tetsuo Handa
2016-02-17 15:01 ` Michal Hocko
2016-02-17 15:29 ` Tetsuo Handa
2016-02-17 16:17 ` Michal Hocko
2016-02-18 11:21 ` Tetsuo Handa
2016-02-17 10:32 ` [PATCH 3/6] mm,oom: exclude oom_task_origin processes if they are OOM victims Tetsuo Handa
2016-02-17 13:02 ` Michal Hocko
2016-02-17 10:33 ` [PATCH 4/6] mm,oom: exclude oom_task_origin processes if they are OOM-unkillable Tetsuo Handa
2016-02-17 13:10 ` Michal Hocko
2016-02-17 13:36 ` Tetsuo Handa
2016-02-17 13:44 ` Michal Hocko
2016-02-17 10:34 ` [PATCH 5/6] mm,oom: Re-enable OOM killer using timers Tetsuo Handa
2016-02-17 13:20 ` Michal Hocko
2016-04-09 14:00 ` Tetsuo Handa
2016-04-09 14:04 ` Tetsuo Handa
2016-02-17 10:36 ` [PATCH 6/6] mm,oom: wait for OOM victims when using oom_kill_allocating_task == 1 Tetsuo Handa
2016-02-17 13:32 ` Michal Hocko
2016-02-18 10:45 ` Tetsuo Handa
2016-02-18 12:20 ` Michal Hocko
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