From: Michal Hocko <mhocko@kernel.org>
To: David Rientjes <rientjes@google.com>
Cc: Oleg Nesterov <oleg@redhat.com>,
linux-mm@kvack.org,
Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>,
Vladimir Davydov <vdavydov@parallels.com>,
Andrew Morton <akpm@linux-foundation.org>,
LKML <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH 06/10] mm, oom: kill all tasks sharing the mm
Date: Thu, 9 Jun 2016 08:46:35 +0200 [thread overview]
Message-ID: <20160609064634.GC24777@dhcp22.suse.cz> (raw)
In-Reply-To: <alpine.DEB.2.10.1606081549490.12203@chino.kir.corp.google.com>
On Wed 08-06-16 15:51:20, David Rientjes wrote:
> On Wed, 8 Jun 2016, Michal Hocko wrote:
>
> > > Why is the patch asking users to report oom killing of a process that
> > > raced with setting /proc/pid/oom_score_adj to OOM_SCORE_ADJ_MIN? What is
> > > possibly actionable about it?
> >
> > Well, the primary point is to know whether such races happen in the real
> > loads and whether they actually matter. If yes we can harden the locking
> > or come up with a less racy solutions.
>
> A thread being set to oom disabled while racing with the oom killer
> obviously isn't a concern: it could very well be set to oom disabled after
> the SIGKILL is sent and before the signal is handled, and that's not even
> fixable without unneeded complexity because we don't know the source of
> the SIGKILL. Please remove the printk entirely.
OK, if you find it more confusing than useful I will not insist.
--
Michal Hocko
SUSE Labs
WARNING: multiple messages have this Message-ID (diff)
From: Michal Hocko <mhocko@kernel.org>
To: David Rientjes <rientjes@google.com>
Cc: Oleg Nesterov <oleg@redhat.com>,
linux-mm@kvack.org,
Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>,
Vladimir Davydov <vdavydov@parallels.com>,
Andrew Morton <akpm@linux-foundation.org>,
LKML <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH 06/10] mm, oom: kill all tasks sharing the mm
Date: Thu, 9 Jun 2016 08:46:35 +0200 [thread overview]
Message-ID: <20160609064634.GC24777@dhcp22.suse.cz> (raw)
In-Reply-To: <alpine.DEB.2.10.1606081549490.12203@chino.kir.corp.google.com>
On Wed 08-06-16 15:51:20, David Rientjes wrote:
> On Wed, 8 Jun 2016, Michal Hocko wrote:
>
> > > Why is the patch asking users to report oom killing of a process that
> > > raced with setting /proc/pid/oom_score_adj to OOM_SCORE_ADJ_MIN? What is
> > > possibly actionable about it?
> >
> > Well, the primary point is to know whether such races happen in the real
> > loads and whether they actually matter. If yes we can harden the locking
> > or come up with a less racy solutions.
>
> A thread being set to oom disabled while racing with the oom killer
> obviously isn't a concern: it could very well be set to oom disabled after
> the SIGKILL is sent and before the signal is handled, and that's not even
> fixable without unneeded complexity because we don't know the source of
> the SIGKILL. Please remove the printk entirely.
OK, if you find it more confusing than useful I will not insist.
--
Michal Hocko
SUSE Labs
--
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next prev parent reply other threads:[~2016-06-09 6:46 UTC|newest]
Thread overview: 75+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-06-03 9:16 [PATCH 0/10 -v3] Handle oom bypass more gracefully Michal Hocko
2016-06-03 9:16 ` Michal Hocko
2016-06-03 9:16 ` [PATCH 01/10] proc, oom: drop bogus task_lock and mm check Michal Hocko
2016-06-03 9:16 ` Michal Hocko
2016-06-03 9:16 ` [PATCH 02/10] proc, oom: drop bogus sighand lock Michal Hocko
2016-06-03 9:16 ` Michal Hocko
2016-06-03 9:16 ` [PATCH 03/10] proc, oom_adj: extract oom_score_adj setting into a helper Michal Hocko
2016-06-03 9:16 ` Michal Hocko
2016-06-03 9:16 ` [PATCH 04/10] mm, oom_adj: make sure processes sharing mm have same view of oom_score_adj Michal Hocko
2016-06-03 9:16 ` Michal Hocko
2016-06-03 9:16 ` [PATCH 05/10] mm, oom: skip vforked tasks from being selected Michal Hocko
2016-06-03 9:16 ` Michal Hocko
2016-06-03 9:16 ` [PATCH 06/10] mm, oom: kill all tasks sharing the mm Michal Hocko
2016-06-03 9:16 ` Michal Hocko
2016-06-06 22:27 ` David Rientjes
2016-06-06 22:27 ` David Rientjes
2016-06-06 23:20 ` Oleg Nesterov
2016-06-06 23:20 ` Oleg Nesterov
2016-06-07 6:37 ` Michal Hocko
2016-06-07 6:37 ` Michal Hocko
2016-06-07 22:15 ` David Rientjes
2016-06-07 22:15 ` David Rientjes
2016-06-08 6:22 ` Michal Hocko
2016-06-08 6:22 ` Michal Hocko
2016-06-08 22:51 ` David Rientjes
2016-06-08 22:51 ` David Rientjes
2016-06-09 6:46 ` Michal Hocko [this message]
2016-06-09 6:46 ` Michal Hocko
2016-06-03 9:16 ` [PATCH 07/10] mm, oom: fortify task_will_free_mem Michal Hocko
2016-06-03 9:16 ` Michal Hocko
2016-06-03 11:42 ` Tetsuo Handa
2016-06-03 12:12 ` Michal Hocko
2016-06-03 9:16 ` [PATCH 08/10] mm, oom: task_will_free_mem should skip oom_reaped tasks Michal Hocko
2016-06-03 9:16 ` Michal Hocko
2016-06-03 9:16 ` [RFC PATCH 09/10] mm, oom_reaper: do not attempt to reap a task more than twice Michal Hocko
2016-06-03 9:16 ` Michal Hocko
2016-06-03 9:16 ` [RFC PATCH 10/10] mm, oom: hide mm which is shared with kthread or global init Michal Hocko
2016-06-03 9:16 ` Michal Hocko
2016-06-03 15:16 ` Tetsuo Handa
2016-06-06 8:15 ` Michal Hocko
2016-06-06 8:15 ` Michal Hocko
2016-06-06 13:26 ` Michal Hocko
2016-06-06 13:26 ` Michal Hocko
2016-06-07 6:26 ` Michal Hocko
2016-06-07 6:26 ` Michal Hocko
2016-06-03 12:00 ` [PATCH 0/10 -v3] Handle oom bypass more gracefully Tetsuo Handa
2016-06-03 12:00 ` Tetsuo Handa
2016-06-03 12:20 ` Michal Hocko
2016-06-03 12:20 ` Michal Hocko
2016-06-03 12:22 ` Michal Hocko
2016-06-03 12:22 ` Michal Hocko
2016-06-04 10:57 ` Tetsuo Handa
2016-06-04 10:57 ` Tetsuo Handa
2016-06-06 8:39 ` Michal Hocko
2016-06-06 8:39 ` Michal Hocko
2016-06-03 15:17 ` Tetsuo Handa
2016-06-03 15:17 ` Tetsuo Handa
2016-06-06 8:36 ` Michal Hocko
2016-06-06 8:36 ` Michal Hocko
2016-06-07 14:30 ` Tetsuo Handa
2016-06-07 14:30 ` Tetsuo Handa
2016-06-07 15:05 ` Michal Hocko
2016-06-07 15:05 ` Michal Hocko
2016-06-07 21:49 ` Tetsuo Handa
2016-06-07 21:49 ` Tetsuo Handa
2016-06-08 7:27 ` Michal Hocko
2016-06-08 7:27 ` Michal Hocko
2016-06-08 14:55 ` Tetsuo Handa
2016-06-08 14:55 ` Tetsuo Handa
2016-06-08 16:05 ` Michal Hocko
2016-06-08 16:05 ` Michal Hocko
2016-06-09 11:52 [PATCH 0/10 -v4] " Michal Hocko
2016-06-09 11:52 ` [PATCH 06/10] mm, oom: kill all tasks sharing the mm Michal Hocko
2016-06-09 11:52 ` Michal Hocko
2016-06-20 12:43 [PATCH 0/10 -v5] Handle oom bypass more gracefully Michal Hocko
2016-06-20 12:43 ` [PATCH 06/10] mm, oom: kill all tasks sharing the mm Michal Hocko
2016-06-20 12:43 ` Michal Hocko
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