From: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
To: mhocko@kernel.org
Cc: linux-mm@kvack.org, rientjes@google.com, oleg@redhat.com,
vdavydov@parallels.com, akpm@linux-foundation.org,
linux-kernel@vger.kernel.org, penguin-kernel@I-love.SAKURA.ne.jp
Subject: Re: [PATCH 10/10] mm, oom: hide mm which is shared with kthread or global init
Date: Thu, 16 Jun 2016 22:36:09 +0900 [thread overview]
Message-ID: <201606162236.DDG82865.OFOtSLMJFVQHOF@I-love.SAKURA.ne.jp> (raw)
In-Reply-To: <201606162215.IIE64528.FFFLHOJQtSOOVM@I-love.SAKURA.ne.jp>
Tetsuo Handa wrote:
> But this is not safe for CONFIG_MMU=y kernels as well.
> can_oom_reap == false means that oom_reap_task() will not be called.
> It is possible that the TIF_MEMDIE thread falls into
>
> atomic_read(&task->signal->oom_victims) > 0 && find_lock_task_mm(task) == NULL
>
> situation. We are still risking OOM livelock. We must somehow clear (or ignore)
> TIF_MEMDIE even if oom_reap_task() is not called.
Oops. mmput() from exit_mm() does not block in that case. So, we won't livelock here.
>
> Can't we apply http://lkml.kernel.org/r/201606102323.BCC73478.FtOJHFQMSVFLOO@I-love.SAKURA.ne.jp now?
>
WARNING: multiple messages have this Message-ID (diff)
From: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
To: mhocko@kernel.org
Cc: linux-mm@kvack.org, rientjes@google.com, oleg@redhat.com,
vdavydov@parallels.com, akpm@linux-foundation.org,
linux-kernel@vger.kernel.org, penguin-kernel@I-love.SAKURA.ne.jp
Subject: Re: [PATCH 10/10] mm, oom: hide mm which is shared with kthread or global init
Date: Thu, 16 Jun 2016 22:36:09 +0900 [thread overview]
Message-ID: <201606162236.DDG82865.OFOtSLMJFVQHOF@I-love.SAKURA.ne.jp> (raw)
In-Reply-To: <201606162215.IIE64528.FFFLHOJQtSOOVM@I-love.SAKURA.ne.jp>
Tetsuo Handa wrote:
> But this is not safe for CONFIG_MMU=y kernels as well.
> can_oom_reap == false means that oom_reap_task() will not be called.
> It is possible that the TIF_MEMDIE thread falls into
>
> atomic_read(&task->signal->oom_victims) > 0 && find_lock_task_mm(task) == NULL
>
> situation. We are still risking OOM livelock. We must somehow clear (or ignore)
> TIF_MEMDIE even if oom_reap_task() is not called.
Oops. mmput() from exit_mm() does not block in that case. So, we won't livelock here.
>
> Can't we apply http://lkml.kernel.org/r/201606102323.BCC73478.FtOJHFQMSVFLOO@I-love.SAKURA.ne.jp now?
>
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next prev parent reply other threads:[~2016-06-16 13:36 UTC|newest]
Thread overview: 94+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-06-09 11:52 [PATCH 0/10 -v4] Handle oom bypass more gracefully Michal Hocko
2016-06-09 11:52 ` Michal Hocko
2016-06-09 11:52 ` [PATCH 01/10] proc, oom: drop bogus task_lock and mm check Michal Hocko
2016-06-09 11:52 ` Michal Hocko
2016-06-09 11:52 ` [PATCH 02/10] proc, oom: drop bogus sighand lock Michal Hocko
2016-06-09 11:52 ` Michal Hocko
2016-06-09 11:52 ` [PATCH 03/10] proc, oom_adj: extract oom_score_adj setting into a helper Michal Hocko
2016-06-09 11:52 ` Michal Hocko
2016-06-09 11:52 ` [PATCH 04/10] mm, oom_adj: make sure processes sharing mm have same view of oom_score_adj Michal Hocko
2016-06-09 11:52 ` Michal Hocko
2016-06-15 15:03 ` Oleg Nesterov
2016-06-15 15:03 ` Oleg Nesterov
2016-06-09 11:52 ` [PATCH 05/10] mm, oom: skip vforked tasks from being selected Michal Hocko
2016-06-09 11:52 ` Michal Hocko
2016-06-15 14:51 ` Oleg Nesterov
2016-06-15 14:51 ` Oleg Nesterov
2016-06-16 6:24 ` Michal Hocko
2016-06-16 6:24 ` 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
2016-06-09 11:52 ` [PATCH 07/10] mm, oom: fortify task_will_free_mem Michal Hocko
2016-06-09 11:52 ` Michal Hocko
2016-06-09 13:18 ` Tetsuo Handa
2016-06-09 13:18 ` Tetsuo Handa
2016-06-09 14:20 ` Michal Hocko
2016-06-09 14:20 ` Michal Hocko
2016-06-11 8:10 ` Tetsuo Handa
2016-06-11 8:10 ` Tetsuo Handa
2016-06-13 11:27 ` Michal Hocko
2016-06-13 11:27 ` Michal Hocko
2016-06-16 12:54 ` Tetsuo Handa
2016-06-16 12:54 ` Tetsuo Handa
2016-06-16 14:29 ` Michal Hocko
2016-06-16 14:29 ` Michal Hocko
2016-06-16 15:40 ` Tetsuo Handa
2016-06-16 15:40 ` Tetsuo Handa
2016-06-16 15:53 ` Michal Hocko
2016-06-16 15:53 ` Michal Hocko
2016-06-17 11:38 ` Tetsuo Handa
2016-06-17 11:38 ` Tetsuo Handa
2016-06-17 12:26 ` Michal Hocko
2016-06-17 12:26 ` Michal Hocko
2016-06-17 13:12 ` Tetsuo Handa
2016-06-17 13:12 ` Tetsuo Handa
2016-06-17 13:29 ` Michal Hocko
2016-06-17 13:29 ` Michal Hocko
2016-06-09 11:52 ` [PATCH 08/10] mm, oom: task_will_free_mem should skip oom_reaped tasks Michal Hocko
2016-06-09 11:52 ` Michal Hocko
2016-06-17 11:35 ` Tetsuo Handa
2016-06-17 11:35 ` Tetsuo Handa
2016-06-17 12:56 ` Michal Hocko
2016-06-17 12:56 ` Michal Hocko
2016-06-09 11:52 ` [PATCH 09/10] mm, oom_reaper: do not attempt to reap a task more than twice Michal Hocko
2016-06-09 11:52 ` Michal Hocko
2016-06-15 14:48 ` Oleg Nesterov
2016-06-15 14:48 ` Oleg Nesterov
2016-06-16 6:28 ` Michal Hocko
2016-06-16 6:28 ` Michal Hocko
2016-06-09 11:52 ` [PATCH 10/10] mm, oom: hide mm which is shared with kthread or global init Michal Hocko
2016-06-09 11:52 ` Michal Hocko
2016-06-09 15:15 ` Tetsuo Handa
2016-06-09 15:15 ` Tetsuo Handa
2016-06-09 15:41 ` Michal Hocko
2016-06-09 15:41 ` Michal Hocko
2016-06-16 13:15 ` Tetsuo Handa
2016-06-16 13:15 ` Tetsuo Handa
2016-06-16 13:36 ` Tetsuo Handa [this message]
2016-06-16 13:36 ` Tetsuo Handa
2016-06-15 14:37 ` Oleg Nesterov
2016-06-15 14:37 ` Oleg Nesterov
2016-06-16 6:31 ` Michal Hocko
2016-06-16 6:31 ` Michal Hocko
2016-06-13 11:23 ` [PATCH 0/10 -v4] Handle oom bypass more gracefully Michal Hocko
2016-06-13 11:23 ` Michal Hocko
2016-06-13 14:13 ` Michal Hocko
2016-06-13 14:13 ` Michal Hocko
2016-06-14 20:17 ` Oleg Nesterov
2016-06-14 20:17 ` Oleg Nesterov
2016-06-14 20:44 ` Oleg Nesterov
2016-06-14 20:44 ` Oleg Nesterov
2016-06-16 6:33 ` Michal Hocko
2016-06-16 6:33 ` Michal Hocko
2016-06-15 15:09 ` Oleg Nesterov
2016-06-15 15:09 ` Oleg Nesterov
2016-06-16 6:34 ` Michal Hocko
2016-06-16 6:34 ` Michal Hocko
2016-06-20 12:43 [PATCH 0/10 -v5] " Michal Hocko
2016-06-20 12:43 ` [PATCH 10/10] mm, oom: hide mm which is shared with kthread or global init Michal Hocko
2016-06-20 12:43 ` Michal Hocko
2016-07-19 12:05 ` Michal Hocko
2016-07-19 12:05 ` Michal Hocko
2016-07-19 23:27 ` Andrew Morton
2016-07-19 23:27 ` Andrew Morton
2016-07-20 6:29 ` Michal Hocko
2016-07-20 6:29 ` Michal Hocko
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