From: Tejun Heo <tj@kernel.org>
To: Michal Hocko <mhocko@suse.cz>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>,
Andrew Morton <akpm@linux-foundation.org>,
Cong Wang <xiyou.wangcong@gmail.com>,
David Rientjes <rientjes@google.com>,
Oleg Nesterov <oleg@redhat.com>,
LKML <linux-kernel@vger.kernel.org>,
linux-mm@kvack.org, Linux PM list <linux-pm@vger.kernel.org>
Subject: Re: [PATCH 3/4] OOM, PM: OOM killed task shouldn't escape PM suspend
Date: Thu, 6 Nov 2014 11:33:04 -0500 [thread overview]
Message-ID: <20141106163304.GE25642@htj.dyndns.org> (raw)
In-Reply-To: <20141106163124.GK7202@dhcp22.suse.cz>
On Thu, Nov 06, 2014 at 05:31:24PM +0100, Michal Hocko wrote:
> On Thu 06-11-14 11:12:11, Tejun Heo wrote:
> > On Thu, Nov 06, 2014 at 05:01:58PM +0100, Michal Hocko wrote:
> > > Yes, OOM killer simply kicks the process sets TIF_MEMDIE and terminates.
> > > That will release the read_lock, allow this to take the write lock and
> > > check whether it the current has been killed without any races.
> > > OOM killer doesn't wait for the killed task. The allocation is retried.
> > >
> > > Does this explain your concern?
> >
> > Draining oom killer then doesn't mean anything, no? OOM killer may
> > have been disabled and drained but the killed tasks might wake up
> > after the PM freezer considers them to be frozen, right? What am I
> > missing?
>
> The mutual exclusion between OOM and the freezer will cause that the
> victim will have TIF_MEMDIE already set when try_to_freeze_tasks even
> starts. Then freezing_slow_path wouldn't allow the task to enter the
> fridge so the wake up moment is not really that important.
What if it was already in the freezer?
--
tejun
WARNING: multiple messages have this Message-ID (diff)
From: Tejun Heo <tj@kernel.org>
To: Michal Hocko <mhocko@suse.cz>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>,
Andrew Morton <akpm@linux-foundation.org>,
Cong Wang <xiyou.wangcong@gmail.com>,
David Rientjes <rientjes@google.com>,
Oleg Nesterov <oleg@redhat.com>,
LKML <linux-kernel@vger.kernel.org>,
linux-mm@kvack.org, Linux PM list <linux-pm@vger.kernel.org>
Subject: Re: [PATCH 3/4] OOM, PM: OOM killed task shouldn't escape PM suspend
Date: Thu, 6 Nov 2014 11:33:04 -0500 [thread overview]
Message-ID: <20141106163304.GE25642@htj.dyndns.org> (raw)
In-Reply-To: <20141106163124.GK7202@dhcp22.suse.cz>
On Thu, Nov 06, 2014 at 05:31:24PM +0100, Michal Hocko wrote:
> On Thu 06-11-14 11:12:11, Tejun Heo wrote:
> > On Thu, Nov 06, 2014 at 05:01:58PM +0100, Michal Hocko wrote:
> > > Yes, OOM killer simply kicks the process sets TIF_MEMDIE and terminates.
> > > That will release the read_lock, allow this to take the write lock and
> > > check whether it the current has been killed without any races.
> > > OOM killer doesn't wait for the killed task. The allocation is retried.
> > >
> > > Does this explain your concern?
> >
> > Draining oom killer then doesn't mean anything, no? OOM killer may
> > have been disabled and drained but the killed tasks might wake up
> > after the PM freezer considers them to be frozen, right? What am I
> > missing?
>
> The mutual exclusion between OOM and the freezer will cause that the
> victim will have TIF_MEMDIE already set when try_to_freeze_tasks even
> starts. Then freezing_slow_path wouldn't allow the task to enter the
> fridge so the wake up moment is not really that important.
What if it was already in the freezer?
--
tejun
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next prev parent reply other threads:[~2014-11-06 16:33 UTC|newest]
Thread overview: 190+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-10-21 7:27 [PATCH 0/4 -v2] OOM vs. freezer interaction fixes Michal Hocko
2014-10-21 7:27 ` Michal Hocko
2014-10-21 7:27 ` Michal Hocko
2014-10-21 7:27 ` [PATCH 1/4] freezer: Do not freeze tasks killed by OOM killer Michal Hocko
2014-10-21 7:27 ` Michal Hocko
2014-10-21 12:04 ` Rafael J. Wysocki
2014-10-21 12:04 ` Rafael J. Wysocki
2014-10-21 7:27 ` [PATCH 2/4] freezer: remove obsolete comments in __thaw_task() Michal Hocko
2014-10-21 7:27 ` Michal Hocko
2014-10-21 12:04 ` Rafael J. Wysocki
2014-10-21 12:04 ` Rafael J. Wysocki
2014-10-21 7:27 ` [PATCH 3/4] OOM, PM: OOM killed task shouldn't escape PM suspend Michal Hocko
2014-10-21 7:27 ` Michal Hocko
2014-10-21 12:09 ` Rafael J. Wysocki
2014-10-21 12:09 ` Rafael J. Wysocki
2014-10-21 13:14 ` Michal Hocko
2014-10-21 13:14 ` Michal Hocko
2014-10-21 13:42 ` Rafael J. Wysocki
2014-10-21 13:42 ` Rafael J. Wysocki
2014-10-21 14:11 ` Michal Hocko
2014-10-21 14:11 ` Michal Hocko
2014-10-21 14:41 ` Rafael J. Wysocki
2014-10-21 14:41 ` Rafael J. Wysocki
2014-10-21 14:29 ` Michal Hocko
2014-10-21 14:29 ` Michal Hocko
2014-10-22 14:39 ` Rafael J. Wysocki
2014-10-22 14:39 ` Rafael J. Wysocki
2014-10-22 14:22 ` Michal Hocko
2014-10-22 14:22 ` Michal Hocko
2014-10-22 21:18 ` Rafael J. Wysocki
2014-10-22 21:18 ` Rafael J. Wysocki
2014-10-26 18:49 ` Pavel Machek
2014-10-26 18:49 ` Pavel Machek
2014-11-04 19:27 ` Tejun Heo
2014-11-04 19:27 ` Tejun Heo
2014-11-05 12:46 ` Michal Hocko
2014-11-05 12:46 ` Michal Hocko
2014-11-05 13:02 ` Tejun Heo
2014-11-05 13:02 ` Tejun Heo
2014-11-05 13:31 ` Michal Hocko
2014-11-05 13:31 ` Michal Hocko
2014-11-05 13:42 ` Michal Hocko
2014-11-05 13:42 ` Michal Hocko
2014-11-05 14:14 ` Michal Hocko
2014-11-05 14:14 ` Michal Hocko
2014-11-05 14:14 ` Michal Hocko
2014-11-05 15:45 ` Michal Hocko
2014-11-05 15:45 ` Michal Hocko
2014-11-05 15:44 ` Tejun Heo
2014-11-05 15:44 ` Tejun Heo
2014-11-05 16:01 ` Michal Hocko
2014-11-05 16:01 ` Michal Hocko
2014-11-05 16:29 ` Tejun Heo
2014-11-05 16:29 ` Tejun Heo
2014-11-05 16:39 ` Michal Hocko
2014-11-05 16:39 ` Michal Hocko
2014-11-05 16:54 ` Tejun Heo
2014-11-05 16:54 ` Tejun Heo
2014-11-05 17:01 ` Tejun Heo
2014-11-05 17:01 ` Tejun Heo
2014-11-06 13:05 ` Michal Hocko
2014-11-06 13:05 ` Michal Hocko
2014-11-06 13:05 ` Michal Hocko
2014-11-06 15:09 ` Tejun Heo
2014-11-06 15:09 ` Tejun Heo
2014-11-06 16:01 ` Michal Hocko
2014-11-06 16:01 ` Michal Hocko
2014-11-06 16:12 ` Tejun Heo
2014-11-06 16:12 ` Tejun Heo
2014-11-06 16:31 ` Michal Hocko
2014-11-06 16:31 ` Michal Hocko
2014-11-06 16:33 ` Tejun Heo [this message]
2014-11-06 16:33 ` Tejun Heo
2014-11-06 16:58 ` Michal Hocko
2014-11-06 16:58 ` Michal Hocko
2014-11-05 17:46 ` Michal Hocko
2014-11-05 17:46 ` Michal Hocko
2014-11-05 17:55 ` Tejun Heo
2014-11-05 17:55 ` Tejun Heo
2014-11-06 12:49 ` Michal Hocko
2014-11-06 12:49 ` Michal Hocko
2014-11-06 15:01 ` Tejun Heo
2014-11-06 15:01 ` Tejun Heo
2014-11-06 16:02 ` Michal Hocko
2014-11-06 16:02 ` Michal Hocko
2014-11-06 16:02 ` Michal Hocko
2014-11-06 16:28 ` Tejun Heo
2014-11-06 16:28 ` Tejun Heo
2014-11-10 16:30 ` Michal Hocko
2014-11-10 16:30 ` Michal Hocko
2014-11-12 18:58 ` [RFC 0/4] OOM vs PM freezer fixes Michal Hocko
2014-11-12 18:58 ` Michal Hocko
2014-11-12 18:58 ` [RFC 1/4] OOM, PM: Do not miss OOM killed frozen tasks Michal Hocko
2014-11-12 18:58 ` Michal Hocko
2014-11-14 17:55 ` Tejun Heo
2014-11-14 17:55 ` Tejun Heo
2014-11-12 18:58 ` [RFC 2/4] OOM, PM: make OOM detection in the freezer path raceless Michal Hocko
2014-11-12 18:58 ` Michal Hocko
2014-11-12 18:58 ` [RFC 3/4] OOM, PM: handle pm freezer as an OOM victim correctly Michal Hocko
2014-11-12 18:58 ` Michal Hocko
2014-11-12 18:58 ` [RFC 4/4] OOM: thaw the OOM victim if it is frozen Michal Hocko
2014-11-12 18:58 ` Michal Hocko
2014-11-14 20:14 ` [RFC 0/4] OOM vs PM freezer fixes Tejun Heo
2014-11-14 20:14 ` Tejun Heo
2014-11-18 21:08 ` Michal Hocko
2014-11-18 21:08 ` Michal Hocko
2014-11-18 21:10 ` [RFC 1/2] oom: add helper for setting and clearing TIF_MEMDIE Michal Hocko
2014-11-18 21:10 ` Michal Hocko
2014-11-18 21:10 ` [RFC 2/2] OOM, PM: make OOM detection in the freezer path raceless Michal Hocko
2014-11-18 21:10 ` Michal Hocko
2014-11-27 0:47 ` Rafael J. Wysocki
2014-11-27 0:47 ` Rafael J. Wysocki
2014-12-02 22:08 ` Tejun Heo
2014-12-02 22:08 ` Tejun Heo
2014-12-04 14:16 ` Michal Hocko
2014-12-04 14:16 ` Michal Hocko
2014-12-04 14:44 ` Tejun Heo
2014-12-04 14:44 ` Tejun Heo
2014-12-04 16:56 ` Michal Hocko
2014-12-04 16:56 ` Michal Hocko
2014-12-04 17:18 ` Michal Hocko
2014-12-04 17:18 ` Michal Hocko
2014-12-05 16:41 ` [PATCH 0/4] OOM vs PM freezer fixes Michal Hocko
2014-12-05 16:41 ` Michal Hocko
2014-12-05 16:41 ` [PATCH -v2 1/5] oom: add helpers for setting and clearing TIF_MEMDIE Michal Hocko
2014-12-05 16:41 ` Michal Hocko
2014-12-06 12:56 ` Tejun Heo
2014-12-06 12:56 ` Tejun Heo
2014-12-07 10:13 ` Michal Hocko
2014-12-07 10:13 ` Michal Hocko
2015-01-07 17:57 ` Tejun Heo
2015-01-07 17:57 ` Tejun Heo
2015-01-07 18:23 ` Michal Hocko
2015-01-07 18:23 ` Michal Hocko
2014-12-05 16:41 ` [PATCH -v2 2/5] OOM: thaw the OOM victim if it is frozen Michal Hocko
2014-12-05 16:41 ` Michal Hocko
2014-12-06 13:06 ` Tejun Heo
2014-12-06 13:06 ` Tejun Heo
2014-12-07 10:24 ` Michal Hocko
2014-12-07 10:24 ` Michal Hocko
2014-12-07 10:45 ` Michal Hocko
2014-12-07 10:45 ` Michal Hocko
2014-12-07 13:59 ` Tejun Heo
2014-12-07 13:59 ` Tejun Heo
2014-12-07 18:55 ` Michal Hocko
2014-12-07 18:55 ` Michal Hocko
2014-12-05 16:41 ` [PATCH -v2 3/5] PM: convert printk to pr_* equivalent Michal Hocko
2014-12-05 16:41 ` Michal Hocko
2014-12-05 22:40 ` Rafael J. Wysocki
2014-12-05 22:40 ` Rafael J. Wysocki
2014-12-07 10:26 ` Michal Hocko
2014-12-07 10:26 ` Michal Hocko
2014-12-06 13:08 ` Tejun Heo
2014-12-06 13:08 ` Tejun Heo
2014-12-05 16:41 ` [PATCH -v2 4/5] sysrq: " Michal Hocko
2014-12-05 16:41 ` Michal Hocko
2014-12-06 13:09 ` Tejun Heo
2014-12-06 13:09 ` Tejun Heo
2014-12-05 16:41 ` [PATCH -v2 5/5] OOM, PM: make OOM detection in the freezer path raceless Michal Hocko
2014-12-05 16:41 ` Michal Hocko
2014-12-06 13:11 ` Tejun Heo
2014-12-06 13:11 ` Tejun Heo
2014-12-07 10:11 ` Michal Hocko
2014-12-07 10:11 ` Michal Hocko
2015-01-07 18:41 ` Tejun Heo
2015-01-07 18:41 ` Tejun Heo
2015-01-07 18:48 ` Michal Hocko
2015-01-07 18:48 ` Michal Hocko
2015-01-08 11:51 ` Michal Hocko
2015-01-08 11:51 ` Michal Hocko
2014-12-07 10:09 ` [PATCH 0/4] OOM vs PM freezer fixes Michal Hocko
2014-12-07 10:09 ` Michal Hocko
2014-12-07 13:55 ` Tejun Heo
2014-12-07 13:55 ` Tejun Heo
2014-12-07 19:00 ` Michal Hocko
2014-12-07 19:00 ` Michal Hocko
2014-12-18 16:27 ` Michal Hocko
2014-12-18 16:27 ` Michal Hocko
2014-11-05 14:55 ` [PATCH 3/4] OOM, PM: OOM killed task shouldn't escape PM suspend Michal Hocko
2014-11-05 14:55 ` Michal Hocko
2014-10-26 18:40 ` Pavel Machek
2014-10-26 18:40 ` Pavel Machek
2014-10-21 7:27 ` [PATCH 4/4] PM: convert do_each_thread to for_each_process_thread Michal Hocko
2014-10-21 7:27 ` Michal Hocko
2014-10-21 12:10 ` Rafael J. Wysocki
2014-10-21 12:10 ` Rafael J. Wysocki
2014-10-21 13:19 ` Michal Hocko
2014-10-21 13:19 ` Michal Hocko
2014-10-21 13:43 ` Rafael J. Wysocki
2014-10-21 13:43 ` Rafael J. Wysocki
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