From: Oleg Nesterov <oleg@redhat.com>
To: Cong Wang <xiyou.wangcong@gmail.com>
Cc: Michal Hocko <mhocko@suse.cz>,
David Rientjes <rientjes@google.com>,
"Rafael J. Wysocki" <rjw@rjwysocki.net>,
Tejun Heo <tj@kernel.org>,
Andrew Morton <akpm@linux-foundation.org>,
LKML <linux-kernel@vger.kernel.org>
Subject: Re: + freezer-check-oom-kill-while-being-frozen.patch added to -mm tree
Date: Thu, 16 Oct 2014 23:35:12 +0200 [thread overview]
Message-ID: <20141016213512.GA28099@redhat.com> (raw)
In-Reply-To: <CAM_iQpXM6eUnvofOq0c71Nx3HygzriKKpN6Vc1+fY=dzFR08ig@mail.gmail.com>
On 10/16, Cong Wang wrote:
>
> On Thu, Oct 16, 2014 at 2:11 PM, Oleg Nesterov <oleg@redhat.com> wrote:
> >
> > But also I can't understand why this patch helps. The changelog says:
> >
> > do_send_sig_info will wake up the thread
> >
> > why?
> >
>
> This is a question for Michal who rewrites my changelog:
>
> http://marc.info/?l=linux-kernel&m=140986986423092&w=2
>
> :)
OK, I hope Michal can answer my question if you do not want to
do this ;) So far I think this patch is not right.
If a task B is already frozen, it sleeps in D state.
If OOM selects B as a victim after that, it won't be woken by
SIGKILL, thus it obviously can't call should_thaw_current() and
notice TIF_MEMDIE.
Btw, I also do not understand the cgroup_freezing() check in
should_thaw_current(), but this is another story.
Oleg.
next prev parent reply other threads:[~2014-10-16 21:38 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-10-16 20:39 + freezer-check-oom-kill-while-being-frozen.patch added to -mm tree Oleg Nesterov
2014-10-16 20:53 ` Cong Wang
2014-10-16 21:11 ` Oleg Nesterov
2014-10-16 21:19 ` Cong Wang
2014-10-16 21:35 ` Oleg Nesterov [this message]
2014-10-16 21:52 ` Cong Wang
2014-10-16 22:22 ` Oleg Nesterov
2014-10-17 2:33 ` Cong Wang
2014-10-17 7:46 ` [PATCH -v2] freezer: check OOM kill while being frozen Michal Hocko
2014-10-17 16:10 ` Oleg Nesterov
2014-10-17 16:20 ` Michal Hocko
2014-10-20 15:17 ` Michal Hocko
2014-10-20 17:40 ` Oleg Nesterov
2014-10-17 15:24 ` + freezer-check-oom-kill-while-being-frozen.patch added to -mm tree Oleg Nesterov
2014-10-17 16:07 ` Michal Hocko
2014-10-17 6:59 ` Michal Hocko
2014-10-17 15:31 ` Oleg Nesterov
2014-10-17 16:06 ` Michal Hocko
-- strict thread matches above, loose matches on Subject: below --
2014-10-14 22:07 akpm
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