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From: Michal Hocko <mhocko@kernel.org>
To: linux-mm@kvack.org
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>,
	David Rientjes <rientjes@google.com>,
	Oleg Nesterov <oleg@redhat.com>,
	Vladimir Davydov <vdavydov@parallels.com>,
	Andrew Morton <akpm@linux-foundation.org>,
	LKML <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH 0/10 -v4] Handle oom bypass more gracefully
Date: Mon, 13 Jun 2016 16:13:24 +0200	[thread overview]
Message-ID: <20160613141324.GK6518@dhcp22.suse.cz> (raw)
In-Reply-To: <20160613112348.GC6518@dhcp22.suse.cz>

On Mon 13-06-16 13:23:48, Michal Hocko wrote:
> On Thu 09-06-16 13:52:07, Michal Hocko wrote:
> > I would like to explore ways how to remove kthreads (use_mm) special
> > case. It shouldn't be that hard, we just have to teach the page fault
> > handler to recognize oom victim mm and enforce EFAULT for kthreads
> > which have borrowed that mm.
> 
> So I was trying to come up with solution for this which would require to
> hook into the pagefault an enforce EFAULT when the mm is being reaped
> by the oom_repaer. Not hard but then I have checked the current users
> and none of them is really needing to read from the userspace (aka
> copy_from_user/get_user). So we actually do not need to do anything
> special.

As pointed out by Tetsuo [1] vhost does realy on copy_from_user. I just
missed that. So scratch this. I will revisit a potential solution for
this but that would be outside of this series scope.

[1] http://lkml.kernel.org/r/201606132252.IAE00593.OJQSFMtVFOLHOF@I-love.SAKURA.ne.jp
-- 
Michal Hocko
SUSE Labs

  reply	other threads:[~2016-06-13 14:13 UTC|newest]

Thread overview: 43+ 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 ` [PATCH 01/10] proc, oom: drop bogus task_lock and mm check Michal Hocko
2016-06-09 11:52 ` [PATCH 02/10] proc, oom: drop bogus sighand lock 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 ` [PATCH 04/10] mm, oom_adj: make sure processes sharing mm have same view of oom_score_adj Michal Hocko
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
2016-06-15 14:51   ` Oleg Nesterov
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 ` [PATCH 07/10] mm, oom: fortify task_will_free_mem Michal Hocko
2016-06-09 13:18   ` Tetsuo Handa
2016-06-09 14:20     ` Michal Hocko
2016-06-11  8:10       ` Tetsuo Handa
2016-06-13 11:27         ` Michal Hocko
2016-06-16 12:54           ` Tetsuo Handa
2016-06-16 14:29             ` Michal Hocko
2016-06-16 15:40               ` Tetsuo Handa
2016-06-16 15:53                 ` Michal Hocko
2016-06-17 11:38                   ` Tetsuo Handa
2016-06-17 12:26                     ` Michal Hocko
2016-06-17 13:12                       ` Tetsuo Handa
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
2016-06-17 11:35   ` Tetsuo Handa
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
2016-06-15 14:48   ` Oleg Nesterov
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 15:15   ` Tetsuo Handa
2016-06-09 15:41     ` Michal Hocko
2016-06-16 13:15       ` Tetsuo Handa
2016-06-16 13:36         ` Tetsuo Handa
2016-06-15 14:37   ` Oleg Nesterov
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 14:13   ` Michal Hocko [this message]
2016-06-14 20:17     ` Oleg Nesterov
2016-06-14 20:44       ` Oleg Nesterov
2016-06-16  6:33       ` Michal Hocko
2016-06-15 15:09 ` Oleg Nesterov
2016-06-16  6:34   ` Michal Hocko

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