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From: Michal Hocko <mhocko@kernel.org>
To: Andrew Morton <akpm@linux-foundation.org>
Cc: David Rientjes <rientjes@google.com>,
	Johannes Weiner <hannes@cmpxchg.org>,
	Roman Gushchin <guro@fb.com>,
	Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>,
	<linux-mm@kvack.org>, LKML <linux-kernel@vger.kernel.org>
Subject: [PATCH 0/2] mm, oom: do not grant oom victims full memory reserves access
Date: Thu, 27 Jul 2017 11:03:55 +0200	[thread overview]
Message-ID: <20170727090357.3205-1-mhocko@kernel.org> (raw)

Hi,
this is a part of a larger series I posted back in Oct last year [1]. I
have dropped patch 3 because it was incorrect and patch 4 is not
applicable without it.

The primary reason to apply patch 1 is to remove a risk of the complete
memory depletion by oom victims. While this is a theoretical risk right
now there is a demand for memcg aware oom killer which might kill all
processes inside a memcg which can be a lot of tasks. That would make
the risk quite real.

This issue is addressed by limiting access to memory reserves. We no
longer use TIF_MEMDIE to grant the access and use tsk_is_oom_victim
instead. See Patch 1 for more details. Patch 2 is a trivial follow up
cleanup.

I would still like to get rid of TIF_MEMDIE completely but I do not have
time to do it now and it is not a pressing issue.

[1] http://lkml.kernel.org/r/20161004090009.7974-1-mhocko@kernel.org

WARNING: multiple messages have this Message-ID (diff)
From: Michal Hocko <mhocko@kernel.org>
To: Andrew Morton <akpm@linux-foundation.org>
Cc: David Rientjes <rientjes@google.com>,
	Johannes Weiner <hannes@cmpxchg.org>,
	Roman Gushchin <guro@fb.com>,
	Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>,
	linux-mm@kvack.org, LKML <linux-kernel@vger.kernel.org>
Subject: [PATCH 0/2] mm, oom: do not grant oom victims full memory reserves access
Date: Thu, 27 Jul 2017 11:03:55 +0200	[thread overview]
Message-ID: <20170727090357.3205-1-mhocko@kernel.org> (raw)

Hi,
this is a part of a larger series I posted back in Oct last year [1]. I
have dropped patch 3 because it was incorrect and patch 4 is not
applicable without it.

The primary reason to apply patch 1 is to remove a risk of the complete
memory depletion by oom victims. While this is a theoretical risk right
now there is a demand for memcg aware oom killer which might kill all
processes inside a memcg which can be a lot of tasks. That would make
the risk quite real.

This issue is addressed by limiting access to memory reserves. We no
longer use TIF_MEMDIE to grant the access and use tsk_is_oom_victim
instead. See Patch 1 for more details. Patch 2 is a trivial follow up
cleanup.

I would still like to get rid of TIF_MEMDIE completely but I do not have
time to do it now and it is not a pressing issue.

[1] http://lkml.kernel.org/r/20161004090009.7974-1-mhocko@kernel.org

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             reply	other threads:[~2017-07-27  9:04 UTC|newest]

Thread overview: 53+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-07-27  9:03 Michal Hocko [this message]
2017-07-27  9:03 ` [PATCH 0/2] mm, oom: do not grant oom victims full memory reserves access Michal Hocko
2017-07-27  9:03 ` [PATCH 1/2] mm, oom: do not rely on TIF_MEMDIE for " Michal Hocko
2017-07-27  9:03   ` Michal Hocko
2017-08-01 15:30   ` Tetsuo Handa
2017-08-01 15:30     ` Tetsuo Handa
2017-08-01 16:52     ` Michal Hocko
2017-08-01 16:52       ` Michal Hocko
2017-08-02  6:10       ` Michal Hocko
2017-08-02  6:10         ` Michal Hocko
2017-08-03  1:39       ` Tetsuo Handa
2017-08-03  1:39         ` Tetsuo Handa
2017-08-03  7:06         ` Michal Hocko
2017-08-03  7:06           ` Michal Hocko
2017-08-03  8:03           ` Tetsuo Handa
2017-08-03  8:03             ` Tetsuo Handa
2017-08-03  8:21             ` Michal Hocko
2017-08-03  8:21               ` Michal Hocko
2017-08-02  8:29   ` [PATCH v2 " Michal Hocko
2017-08-02  8:29     ` Michal Hocko
2017-08-03  9:37     ` Mel Gorman
2017-08-03  9:37       ` Mel Gorman
2017-08-03 11:00       ` Michal Hocko
2017-08-03 11:00         ` Michal Hocko
2017-08-03 12:22         ` Mel Gorman
2017-08-03 12:22           ` Mel Gorman
2017-07-27  9:03 ` [PATCH 2/2] mm: replace TIF_MEMDIE checks by tsk_is_oom_victim Michal Hocko
2017-07-27  9:03   ` Michal Hocko
2017-07-27 14:01   ` Tetsuo Handa
2017-07-27 14:01     ` Tetsuo Handa
2017-07-27 14:08     ` Tetsuo Handa
2017-07-27 14:08       ` Tetsuo Handa
2017-07-27 14:18     ` Michal Hocko
2017-07-27 14:18       ` Michal Hocko
2017-07-27 14:45     ` Michal Hocko
2017-07-27 14:45       ` Michal Hocko
2017-07-27 14:55       ` Roman Gushchin
2017-07-27 14:55         ` Roman Gushchin
2017-07-29  8:33   ` kbuild test robot
2017-07-31  6:46     ` Michal Hocko
2017-07-31  6:46       ` Michal Hocko
2017-08-01 12:16 ` [PATCH 0/2] mm, oom: do not grant oom victims full memory reserves access Michal Hocko
2017-08-01 12:16   ` Michal Hocko
2017-08-01 12:23   ` Roman Gushchin
2017-08-01 12:23     ` Roman Gushchin
2017-08-01 12:29     ` Michal Hocko
2017-08-01 12:29       ` Michal Hocko
2017-08-01 12:42       ` Roman Gushchin
2017-08-01 12:42         ` Roman Gushchin
2017-08-01 12:54         ` Michal Hocko
2017-08-01 12:54           ` Michal Hocko
2017-08-07 14:21 ` Michal Hocko
2017-08-07 14:21   ` Michal Hocko

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