From: Oleg Nesterov <oleg@redhat.com>
To: Michal Hocko <mhocko@kernel.org>
Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>,
linux-mm@kvack.org, Andrew Morton <akpm@linux-foundation.org>,
Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>,
David Rientjes <rientjes@google.com>,
Vladimir Davydov <vdavydov@parallels.com>,
"Michael S. Tsirkin" <mst@redhat.com>
Subject: Re: [PATCH 09/10] vhost, mm: make sure that oom_reaper doesn't reap memory read by vhost
Date: Fri, 12 Aug 2016 18:05:12 +0200 [thread overview]
Message-ID: <20160812160512.GA30930@redhat.com> (raw)
In-Reply-To: <20160812144157.GL3639@dhcp22.suse.cz>
On 08/12, Michal Hocko wrote:
>
> On Fri 12-08-16 15:21:41, Oleg Nesterov wrote:
>
> > Whats really interesting is that I still fail to understand do we really
> > need this hack, iiuc you are not sure too, and Michael didn't bother to
> > explain why a bogus zero from anon memory is worse than other problems
> > caused by SIGKKILL from oom-kill.c.
>
> Yes, I admit that I am not familiar with the vhost memory usage model so
> I can only speculate. But the mere fact that the mm is bound to a device
> fd
Yes, and I already tried to complain. This doesn't look right in any case.
> which can be passed over to a different process makes me worried.
> This means that the mm is basically isolated from the original process
> until the last fd is closed which is under control of the process which
> holds it. The mm can still be access during that time from the vhost
> worker. And I guess this is exactly where the problem lies.
Agreed.
Oleg.
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next prev parent reply other threads:[~2016-08-12 16:05 UTC|newest]
Thread overview: 47+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-07-28 19:42 [RFC PATCH 0/10] fortify oom killer even more Michal Hocko
2016-07-28 19:42 ` [PATCH 01/10] mm,oom_reaper: Reduce find_lock_task_mm() usage Michal Hocko
2016-07-28 19:42 ` [PATCH 02/10] mm,oom_reaper: Do not attempt to reap a task twice Michal Hocko
2016-07-28 19:42 ` [PATCH 03/10] oom: keep mm of the killed task available Michal Hocko
2016-07-28 19:42 ` [PATCH 04/10] mm, oom: get rid of signal_struct::oom_victims Michal Hocko
2016-07-28 19:42 ` [PATCH 05/10] kernel, oom: fix potential pgd_lock deadlock from __mmdrop Michal Hocko
2016-07-28 19:42 ` [PATCH 06/10] oom, suspend: fix oom_killer_disable vs. pm suspend properly Michal Hocko
2016-07-28 19:42 ` [PATCH 07/10] mm, oom: enforce exit_oom_victim on current task Michal Hocko
2016-07-28 19:42 ` [PATCH 08/10] exit, oom: postpone exit_oom_victim to later Michal Hocko
2016-07-30 8:20 ` Tetsuo Handa
2016-07-31 9:35 ` Michal Hocko
2016-07-31 10:19 ` Michal Hocko
2016-08-01 10:46 ` Tetsuo Handa
2016-08-01 11:33 ` Michal Hocko
2016-08-02 10:32 ` Tetsuo Handa
2016-08-02 11:31 ` Michal Hocko
2016-07-28 19:42 ` [PATCH 09/10] vhost, mm: make sure that oom_reaper doesn't reap memory read by vhost Michal Hocko
2016-07-28 20:41 ` Michael S. Tsirkin
2016-07-29 6:04 ` Michal Hocko
2016-07-29 13:14 ` Michael S. Tsirkin
2016-07-29 13:35 ` Michal Hocko
2016-07-29 17:57 ` Michael S. Tsirkin
2016-07-31 9:44 ` Michal Hocko
2016-08-12 9:42 ` Michal Hocko
2016-08-12 13:21 ` Oleg Nesterov
2016-08-12 14:41 ` Michal Hocko
2016-08-12 16:05 ` Oleg Nesterov [this message]
2016-08-12 15:57 ` Paul E. McKenney
2016-08-12 16:09 ` Oleg Nesterov
2016-08-12 16:26 ` Paul E. McKenney
2016-08-12 16:23 ` Michal Hocko
2016-08-13 0:15 ` Michael S. Tsirkin
2016-08-14 8:41 ` Michal Hocko
2016-08-14 16:57 ` Michael S. Tsirkin
2016-08-14 23:06 ` Michael S. Tsirkin
2016-08-15 9:49 ` Michal Hocko
2016-08-17 16:58 ` Michal Hocko
2016-08-22 13:03 ` Michal Hocko
2016-08-22 21:01 ` Michael S. Tsirkin
2016-08-23 7:55 ` Michal Hocko
2016-08-23 9:06 ` Michal Hocko
2016-08-23 12:54 ` Michael S. Tsirkin
2016-08-24 16:42 ` Michal Hocko
2016-08-12 9:43 ` Michal Hocko
2016-07-29 17:07 ` Oleg Nesterov
2016-07-31 9:11 ` Michal Hocko
2016-07-28 19:42 ` [PATCH 10/10] oom, oom_reaper: allow to reap mm shared by the kthreads Michal Hocko
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