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From: Johannes Weiner <hannes@cmpxchg.org>
To: Theodore Ts'o <tytso@mit.edu>
Cc: Dave Chinner <david@fromorbit.com>,
	Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>,
	mhocko@suse.cz, dchinner@redhat.com, linux-mm@kvack.org,
	rientjes@google.com, oleg@redhat.com, akpm@linux-foundation.org,
	mgorman@suse.de, torvalds@linux-foundation.org, xfs@oss.sgi.com
Subject: Re: How to handle TIF_MEMDIE stalls?
Date: Sat, 28 Feb 2015 17:15:58 -0500	[thread overview]
Message-ID: <20150228221558.GA23028@phnom.home.cmpxchg.org> (raw)
In-Reply-To: <20150228164158.GE5404@thunk.org>

On Sat, Feb 28, 2015 at 11:41:58AM -0500, Theodore Ts'o wrote:
> On Sat, Feb 28, 2015 at 11:29:43AM -0500, Johannes Weiner wrote:
> > 
> > I'm trying to figure out if the current nofail allocators can get
> > their memory needs figured out beforehand.  And reliably so - what
> > good are estimates that are right 90% of the time, when failing the
> > allocation means corrupting user data?  What is the contingency plan?
> 
> In the ideal world, we can figure out the exact memory needs
> beforehand.  But we live in an imperfect world, and given that block
> devices *also* need memory, the answer is "of course not".  We can't
> be perfect.  But we can least give some kind of hint, and we can offer
> to wait before we get into a situation where we need to loop in
> GFP_NOWAIT --- which is the contingency/fallback plan.

Overestimating should be fine, the result would a bit of false memory
pressure.  But underestimating and looping can't be an option or the
original lockups will still be there.  We need to guarantee forward
progress or the problem is somewhat mitigated at best - only now with
quite a bit more complexity in the allocator and the filesystems.

The block code would have to be looked at separately, but doesn't it
already use mempools etc. to guarantee progress?

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  reply	other threads:[~2015-02-28 22:16 UTC|newest]

Thread overview: 177+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-12-12 13:54 [RFC PATCH] oom: Don't count on mm-less current process Tetsuo Handa
2014-12-16 12:47 ` Michal Hocko
2014-12-17 11:54   ` Tetsuo Handa
2014-12-17 13:08     ` Michal Hocko
2014-12-18 12:11       ` Tetsuo Handa
2014-12-18 15:33         ` Michal Hocko
2014-12-19 12:07           ` Tetsuo Handa
2014-12-19 12:49             ` Michal Hocko
2014-12-20  9:13               ` Tetsuo Handa
2014-12-20 11:42                 ` Tetsuo Handa
2014-12-22 20:25                   ` Michal Hocko
2014-12-23  1:00                     ` Tetsuo Handa
2014-12-23  9:51                       ` Michal Hocko
2014-12-23 11:46                         ` Tetsuo Handa
2014-12-23 11:57                           ` Tetsuo Handa
2014-12-23 12:12                             ` Tetsuo Handa
2014-12-23 12:27                             ` Michal Hocko
2014-12-23 12:24                           ` Michal Hocko
2014-12-23 13:00                             ` Tetsuo Handa
2014-12-23 13:09                               ` Michal Hocko
2014-12-23 13:20                                 ` Tetsuo Handa
2014-12-23 13:43                                   ` Michal Hocko
2014-12-23 14:11                                     ` Tetsuo Handa
2014-12-23 14:57                                       ` Michal Hocko
2014-12-19 12:22           ` How to handle TIF_MEMDIE stalls? Tetsuo Handa
2014-12-20  2:03             ` Dave Chinner
2014-12-20 12:41               ` Tetsuo Handa
2014-12-20 22:35                 ` Dave Chinner
2014-12-21  8:45                   ` Tetsuo Handa
2014-12-21 20:42                     ` Dave Chinner
2014-12-22 16:57                       ` Michal Hocko
2014-12-22 21:30                         ` Dave Chinner
2014-12-23  9:41                           ` Johannes Weiner
2014-12-24  1:06                             ` Dave Chinner
2014-12-24  2:40                               ` Linus Torvalds
2014-12-29 18:19                     ` Michal Hocko
2014-12-30  6:42                       ` Tetsuo Handa
2014-12-30 11:21                         ` Michal Hocko
2014-12-30 13:33                           ` Tetsuo Handa
2014-12-31 10:24                             ` Tetsuo Handa
2015-02-09 11:44                           ` Tetsuo Handa
2015-02-10 13:58                             ` Tetsuo Handa
2015-02-10 15:19                               ` Johannes Weiner
2015-02-11  2:23                                 ` Tetsuo Handa
2015-02-11 13:37                                   ` Tetsuo Handa
2015-02-11 18:50                                     ` Oleg Nesterov
2015-02-11 18:59                                       ` Oleg Nesterov
2015-03-14 13:03                                         ` Tetsuo Handa
2015-02-17 12:23                                   ` Tetsuo Handa
2015-02-17 12:53                                     ` Johannes Weiner
2015-02-17 15:38                                       ` Michal Hocko
2015-02-17 22:54                                       ` Dave Chinner
2015-02-17 23:32                                         ` Dave Chinner
2015-02-18  8:25                                         ` Michal Hocko
2015-02-18 10:48                                           ` Dave Chinner
2015-02-18 12:16                                             ` Michal Hocko
2015-02-18 21:31                                               ` Dave Chinner
2015-02-19  9:40                                                 ` Michal Hocko
2015-02-19 22:03                                                   ` Dave Chinner
2015-02-20  9:27                                                     ` Michal Hocko
2015-02-19 11:01                                               ` Johannes Weiner
2015-02-19 12:29                                                 ` Michal Hocko
2015-02-19 12:58                                                   ` Michal Hocko
2015-02-19 15:29                                                     ` Tetsuo Handa
2015-02-19 21:53                                                       ` Tetsuo Handa
2015-02-20  9:13                                                       ` Michal Hocko
2015-02-20 13:37                                                         ` Stefan Ring
2015-02-19 13:29                                                   ` Tetsuo Handa
2015-02-20  9:10                                                     ` Michal Hocko
2015-02-20 12:20                                                       ` Tetsuo Handa
2015-02-20 12:38                                                         ` Michal Hocko
2015-02-19 21:43                                                   ` Dave Chinner
2015-02-20 12:48                                                     ` Michal Hocko
2015-02-20 23:09                                                       ` Dave Chinner
2015-02-19 10:24                                         ` Johannes Weiner
2015-02-19 22:52                                           ` Dave Chinner
2015-02-20 10:36                                             ` Tetsuo Handa
2015-02-20 23:15                                               ` Dave Chinner
2015-02-21  3:20                                                 ` Theodore Ts'o
2015-02-21  9:19                                                   ` Andrew Morton
2015-02-21 13:48                                                     ` Tetsuo Handa
2015-02-21 21:38                                                     ` Dave Chinner
2015-02-22  0:20                                                     ` Johannes Weiner
2015-02-23 10:48                                                       ` Michal Hocko
2015-02-23 11:23                                                         ` Tetsuo Handa
2015-02-23 21:33                                                       ` David Rientjes
2015-02-22 14:48                                                     ` __GFP_NOFAIL and oom_killer_disabled? Tetsuo Handa
2015-02-23 10:21                                                       ` Michal Hocko
2015-02-23 13:03                                                         ` Tetsuo Handa
2015-02-24 18:14                                                           ` Michal Hocko
2015-02-25 11:22                                                             ` Tetsuo Handa
2015-02-25 16:02                                                               ` Michal Hocko
2015-02-25 21:48                                                                 ` Tetsuo Handa
2015-02-25 21:51                                                                   ` Andrew Morton
2015-02-21 12:00                                                   ` How to handle TIF_MEMDIE stalls? Tetsuo Handa
2015-02-23 10:26                                                   ` Michal Hocko
2015-02-21 11:12                                                 ` Tetsuo Handa
2015-02-21 21:48                                                   ` Dave Chinner
2015-02-21 23:52                                             ` Johannes Weiner
2015-02-23  0:45                                               ` Dave Chinner
2015-02-23  1:29                                                 ` Andrew Morton
2015-02-23  7:32                                                   ` Dave Chinner
2015-02-27 18:24                                                     ` Vlastimil Babka
2015-02-28  0:03                                                       ` Dave Chinner
2015-02-28 15:17                                                         ` Theodore Ts'o
2015-03-02  9:39                                                     ` Vlastimil Babka
2015-03-02 22:31                                                       ` Dave Chinner
2015-03-03  9:13                                                         ` Vlastimil Babka
2015-03-04  1:33                                                           ` Dave Chinner
2015-03-04  8:50                                                             ` Vlastimil Babka
2015-03-04 11:03                                                               ` Dave Chinner
2015-03-07  0:20                                                         ` Johannes Weiner
2015-03-07  3:43                                                           ` Dave Chinner
2015-03-07 15:08                                                             ` Johannes Weiner
2015-03-02 20:22                                                     ` Johannes Weiner
2015-03-02 23:12                                                       ` Dave Chinner
2015-03-03  2:50                                                         ` Johannes Weiner
2015-03-04  6:52                                                           ` Dave Chinner
2015-03-04 15:04                                                             ` Johannes Weiner
2015-03-04 17:38                                                               ` Theodore Ts'o
2015-03-04 23:17                                                                 ` Dave Chinner
2015-02-28 16:29                                                 ` Johannes Weiner
2015-02-28 16:41                                                   ` Theodore Ts'o
2015-02-28 22:15                                                     ` Johannes Weiner [this message]
2015-03-01 11:17                                                       ` Tetsuo Handa
2015-03-06 11:53                                                         ` Tetsuo Handa
2015-03-01 13:43                                                       ` Theodore Ts'o
2015-03-01 16:15                                                         ` Johannes Weiner
2015-03-01 19:36                                                           ` Theodore Ts'o
2015-03-01 20:44                                                             ` Johannes Weiner
2015-03-01 20:17                                                         ` Johannes Weiner
2015-03-01 21:48                                                       ` Dave Chinner
2015-03-02  0:17                                                         ` Dave Chinner
2015-03-02 12:46                                                           ` Brian Foster
2015-02-28 18:36                                                 ` Vlastimil Babka
2015-03-02 15:18                                                 ` Michal Hocko
2015-03-02 16:05                                                   ` Johannes Weiner
2015-03-02 17:10                                                     ` Michal Hocko
2015-03-02 17:27                                                       ` Johannes Weiner
2015-03-02 16:39                                                   ` Theodore Ts'o
2015-03-02 16:58                                                     ` Michal Hocko
2015-03-04 12:52                                                       ` Dave Chinner
2015-02-17 14:59                                     ` Michal Hocko
2015-02-17 14:50                                 ` Michal Hocko
2015-02-17 14:37                             ` Michal Hocko
2015-02-17 14:44                               ` Michal Hocko
2015-02-16 11:23                           ` Tetsuo Handa
2015-02-16 15:42                             ` Johannes Weiner
2015-02-17 11:57                               ` Tetsuo Handa
2015-02-17 13:16                                 ` Johannes Weiner
2015-02-17 16:50                                   ` Michal Hocko
2015-02-17 23:25                                     ` Dave Chinner
2015-02-18  8:48                                       ` Michal Hocko
2015-02-18 11:23                                         ` Tetsuo Handa
2015-02-18 12:29                                           ` Michal Hocko
2015-02-18 14:06                                             ` Tetsuo Handa
2015-02-18 14:25                                               ` Michal Hocko
2015-02-19 10:48                                                 ` Tetsuo Handa
2015-02-20  8:26                                                   ` Michal Hocko
2015-02-23 22:08                                 ` David Rientjes
2015-02-24 11:20                                   ` Tetsuo Handa
2015-02-24 15:20                                     ` Theodore Ts'o
2015-02-24 21:02                                       ` Dave Chinner
2015-02-25 14:31                                         ` Tetsuo Handa
2015-02-27  7:39                                           ` Dave Chinner
2015-02-27 12:42                                             ` Tetsuo Handa
2015-02-27 13:12                                               ` Dave Chinner
2015-03-04 12:41                                                 ` Tetsuo Handa
2015-03-04 13:25                                                   ` Dave Chinner
2015-03-04 14:11                                                     ` Tetsuo Handa
2015-03-05  1:36                                                       ` Dave Chinner
2015-02-17 16:33                             ` Michal Hocko
2014-12-29 17:40                   ` [PATCH] mm: get rid of radix tree gfp mask for pagecache_get_page (was: Re: How to handle TIF_MEMDIE stalls?) Michal Hocko
2014-12-29 18:45                     ` Linus Torvalds
2014-12-29 19:33                       ` Michal Hocko
2014-12-30 13:42                         ` Michal Hocko
2014-12-30 21:45                           ` Linus Torvalds

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