From: Michal Hocko <mhocko@kernel.org>
To: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: linux-mm@kvack.org, rientjes@google.com, oleg@redhat.com,
vdavydov@parallels.com, mgorman@techsingularity.net,
hughd@google.com, riel@redhat.com, akpm@linux-foundation.org,
linux-kernel@vger.kernel.org
Subject: Re: mm, oom_reaper: How to handle race with oom_killer_disable() ?
Date: Tue, 21 Jun 2016 10:31:54 +0200 [thread overview]
Message-ID: <20160621083154.GA30848@dhcp22.suse.cz> (raw)
In-Reply-To: <20160613111943.GB6518@dhcp22.suse.cz>
On Mon 13-06-16 13:19:43, Michal Hocko wrote:
[...]
> I am trying to remember why we are disabling oom killer before kernel
> threads are frozen but not really sure about that right away.
OK, I guess I remember now. Say that a task would depend on a freezable
kernel thread to get to do_exit (stuck in wait_event etc...). We would
simply get stuck in oom_killer_disable for ever. So we need to address
it a different way.
One way would be what you are proposing but I guess it would be more
systematic to never call exit_oom_victim on a remote task. After [1] we
have a solid foundation to rely only on MMF_REAPED even when TIF_MEMDIE
is set. It is more code than your patch so I can see a reason to go with
yours if the following one seems too large or ugly.
[1] http://lkml.kernel.org/r/1466426628-15074-1-git-send-email-mhocko@kernel.org
What do you think about the following?
---
next prev parent reply other threads:[~2016-06-21 8:39 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-06-10 14:23 mm, oom_reaper: How to handle race with oom_killer_disable() ? Tetsuo Handa
2016-06-13 11:19 ` Michal Hocko
2016-06-21 8:31 ` Michal Hocko [this message]
2016-06-21 11:03 ` Tetsuo Handa
2016-06-21 11:46 ` Michal Hocko
2016-06-21 13:27 ` Michal Hocko
2016-06-21 15:32 ` Tetsuo Handa
2016-06-21 17:46 ` Michal Hocko
2016-06-21 21:47 ` Tetsuo Handa
2016-06-22 6:40 ` Michal Hocko
2016-06-22 6:50 ` Michal Hocko
2016-06-22 10:57 ` Tetsuo Handa
2016-06-22 12:08 ` Michal Hocko
2016-06-22 12:15 ` Michal Hocko
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