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From: Mike Galbraith <efault@gmx.de>
To: Thomas Gleixner <tglx@linutronix.de>
Cc: Jan Kara <jack@suse.cz>, Jeff Moyer <jmoyer@redhat.com>,
	LKML <linux-kernel@vger.kernel.org>,
	linux-fsdevel@vger.kernel.org, Tejun Heo <tj@kernel.org>,
	Jens Axboe <jaxboe@fusionio.com>,
	mgalbraith@suse.com, Steven Rostedt <rostedt@goodmis.org>
Subject: Re: Deadlocks due to per-process plugging
Date: Sat, 21 Jul 2012 09:47:15 +0200	[thread overview]
Message-ID: <1342856835.7739.19.camel@marge.simpson.net> (raw)
In-Reply-To: <1342589411.7321.59.camel@marge.simpson.net>

On Wed, 2012-07-18 at 07:30 +0200, Mike Galbraith wrote: 
> On Wed, 2012-07-18 at 06:44 +0200, Mike Galbraith wrote:
> 
> > The patch in question for missing Cc.  Maybe should be only mutex, but I
> > see no reason why IO dependency can only possibly exist for mutexes...
> 
> Well that was easy, box quickly said "nope, mutex only does NOT cut it".

And I also learned (ouch) that both doesn't cut it either.  Ksoftirqd
(or sirq-blk) being nailed by q->lock in blk_done_softirq() is.. not
particularly wonderful.  As long as that doesn't happen, IO deadlock
doesn't happen, troublesome filesystems just work.  If it does happen
though, you've instantly got a problem.

-Mike


  reply	other threads:[~2012-07-21  7:47 UTC|newest]

Thread overview: 33+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-07-11 13:37 Deadlocks due to per-process plugging Jan Kara
2012-07-11 16:05 ` Jeff Moyer
2012-07-11 20:16   ` Jan Kara
2012-07-11 22:12     ` Thomas Gleixner
2012-07-12  4:12       ` Mike Galbraith
2012-07-13 12:38       ` Jan Kara
2012-07-12  2:07     ` Mike Galbraith
2012-07-12 14:15     ` Thomas Gleixner
2012-07-13 12:33       ` Jan Kara
2012-07-13 14:25         ` Thomas Gleixner
2012-07-13 14:46           ` Jan Kara
2012-07-15  8:59             ` Thomas Gleixner
2012-07-15  9:14               ` Mike Galbraith
2012-07-15  9:51                 ` Thomas Gleixner
2012-07-16  2:22                 ` Mike Galbraith
2012-07-16  8:59                   ` Thomas Gleixner
2012-07-16  9:48                     ` Mike Galbraith
2012-07-16  9:59                       ` Thomas Gleixner
2012-07-16 10:13                         ` Mike Galbraith
2012-07-16 10:08                       ` Mike Galbraith
2012-07-16 10:19                         ` Thomas Gleixner
2012-07-16 10:30                           ` Mike Galbraith
2012-07-16 11:24                           ` Mike Galbraith
2012-07-16 14:35                             ` Mike Galbraith
2012-07-17 13:10                           ` Mike Galbraith
2012-07-18  4:44                             ` Mike Galbraith
2012-07-18  5:30                               ` Mike Galbraith
2012-07-21  7:47                                 ` Mike Galbraith [this message]
2012-07-22 18:43                                   ` Mike Galbraith
2012-07-23  9:46                                     ` Mike Galbraith
2012-07-14 11:00           ` Mike Galbraith
2012-07-14 11:06             ` Mike Galbraith
2012-07-15  7:14             ` Mike Galbraith

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