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From: "Rafael J. Wysocki" <rjw@rjwysocki.net>
To: Tejun Heo <tj@kernel.org>
Cc: Michal Hocko <mhocko@suse.cz>,
	Cong Wang <xiyou.wangcong@gmail.com>,
	LKML <linux-kernel@vger.kernel.org>,
	David Rientjes <rientjes@google.com>,
	Andrew Morton <akpm@linux-foundation.org>
Subject: Re: [Patch v4 1/2] freezer: check OOM kill while being frozen
Date: Tue, 09 Sep 2014 22:48:29 +0200	[thread overview]
Message-ID: <5074996.Ni2JIb7nJr@vostro.rjw.lan> (raw)
In-Reply-To: <20140909152336.GB8890@mtj.dyndns.org>

On Wednesday, September 10, 2014 12:23:36 AM Tejun Heo wrote:
> On Tue, Sep 09, 2014 at 05:16:55PM +0200, Michal Hocko wrote:
> > But OOM killer doesn't kill kernel threads as they do not own any
> > memory. So the check should be safe, no?
> 
> Even for userland tasks, try_to_freeze() can currently be anywhere in
> the kernel.  The frequently used ones are few but there are some odd
> ones out, and, again, there's nothing enforcing any structure on
> try_to_freeze() usage.  The other thing is that we may do quite a bit
> during exiting including allocating memory.  Are those safe for system
> PM?  Rafael, what exactly are the rules for PM?  What shouldn't
> change?

We can't make any assumptions regarding the availability of any devices.
That is, whatever can end up in device access may potentially fail.

Rafael


  parent reply	other threads:[~2014-09-09 20:29 UTC|newest]

Thread overview: 61+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-09-04 22:30 [Patch v4 1/2] freezer: check OOM kill while being frozen Cong Wang
2014-09-04 22:30 ` [Patch v4 2/2] freezer: remove obsolete comments in __thaw_task() Cong Wang
2014-09-05  9:45   ` Michal Hocko
2014-09-05 14:09   ` Tejun Heo
2014-09-05 14:08 ` [Patch v4 1/2] freezer: check OOM kill while being frozen Tejun Heo
2014-09-05 16:31   ` Cong Wang
2014-09-05 18:00     ` Tejun Heo
2014-09-05 18:12       ` Cong Wang
2014-09-05 22:45         ` Tejun Heo
2014-09-05 23:32           ` Rafael J. Wysocki
2014-09-08 17:40             ` Cong Wang
2014-09-08 20:54               ` Rafael J. Wysocki
2014-09-08 20:58                 ` Cong Wang
2014-09-08 21:53                   ` Rafael J. Wysocki
2014-09-08 22:22                     ` Tejun Heo
2014-09-08 22:48                       ` Rafael J. Wysocki
2014-09-08 22:50                         ` Tejun Heo
2014-09-08 23:15                           ` Rafael J. Wysocki
2014-09-08 23:00                             ` Cong Wang
2014-09-08 23:23                               ` Rafael J. Wysocki
2014-09-08 23:16                                 ` Cong Wang
2014-09-08 23:42                                   ` Rafael J. Wysocki
2014-09-08 23:29                                     ` Cong Wang
2014-09-08 23:59                                       ` Rafael J. Wysocki
2014-09-10 20:30                                       ` Cong Wang
2014-09-10 23:38                                         ` Rafael J. Wysocki
2014-09-10 23:20                                           ` Cong Wang
2014-09-11 16:30                                         ` Michal Hocko
2014-09-12 23:59                                           ` Tejun Heo
2014-09-14 16:43                                             ` Rafael J. Wysocki
2014-09-15  0:56                                               ` Tejun Heo
2014-09-15  3:34                                                 ` Rafael J. Wysocki
2014-09-15  9:36                                                   ` Michal Hocko
2014-09-16 22:55                                                     ` Cong Wang
2014-09-22  8:21                                                       ` Michal Hocko
2014-09-09 15:16                           ` Michal Hocko
2014-09-09 15:23                             ` Tejun Heo
2014-09-09 16:06                               ` Michal Hocko
2014-09-09 16:46                                 ` Tejun Heo
2014-09-09 17:12                                   ` Michal Hocko
2014-09-09 20:53                                   ` Rafael J. Wysocki
2014-09-10 13:24                                     ` Michal Hocko
2014-09-11 13:08                                       ` Michal Hocko
2014-09-11 14:17                                         ` Rafael J. Wysocki
2014-09-11 14:04                                           ` Michal Hocko
2014-09-11 14:26                                             ` Rafael J. Wysocki
2014-09-11 14:10                                               ` Michal Hocko
2014-09-11 14:32                                                 ` Rafael J. Wysocki
2014-09-11 14:28                                                   ` Michal Hocko
2014-09-11 14:52                                                     ` Rafael J. Wysocki
2014-09-11 14:45                                                       ` Michal Hocko
2014-09-14 16:39                                                         ` Rafael J. Wysocki
2014-09-12 23:48                                       ` Tejun Heo
2014-09-15 14:28                                         ` Michal Hocko
2014-09-16  5:56                                           ` Tejun Heo
2014-09-09 20:48                               ` Rafael J. Wysocki [this message]
2014-09-10  5:21                                 ` Cong Wang
2014-09-05 16:43   ` Cong Wang
2014-09-05 16:54     ` Michal Hocko
2014-09-15 11:22 ` Michal Hocko
2014-09-16 22:58   ` Cong Wang

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