From: Mike Galbraith <mgalbraith@novell.com>
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
Subject: Re: Deadlocks due to per-process plugging
Date: Mon, 16 Jul 2012 12:13:05 +0200 [thread overview]
Message-ID: <1342433585.7659.46.camel@marge.simpson.net> (raw)
In-Reply-To: <alpine.LFD.2.02.1207161157510.32033@ionos>
On Mon, 2012-07-16 at 11:59 +0200, Thomas Gleixner wrote:
> On Mon, 16 Jul 2012, Mike Galbraith wrote:
> > On Mon, 2012-07-16 at 10:59 +0200, Thomas Gleixner wrote:
> > > On Mon, 16 Jul 2012, Mike Galbraith wrote:
> > > > On Sun, 2012-07-15 at 11:14 +0200, Mike Galbraith wrote:
> > > > > On Sun, 2012-07-15 at 10:59 +0200, Thomas Gleixner wrote:
> > > >
> > > > > > Can you figure out on which lock the stuck thread which did not unplug
> > > > > > due to tsk_is_pi_blocked was blocked?
> > > > >
> > > > > I'll take a peek.
> > > >
> > > > Sorry for late reply, took a half day away from box. Jan had already
> > > > done the full ext3 IO deadlock analysis:
> > > >
> > > > Again kjournald is waiting for buffer IO on block 4367635 (sector
> > > > 78364838) to finish. Now it is dbench thread 0xffff88026f330e70 which
> > > > has submitted this buffer for IO and is still holding this buffer behind
> > > > its plug (request for sector 78364822..78364846). The dbench thread is
> > > > waiting on j_checkpoint mutex (apparently it has successfully got the
> > > > mutex in the past, checkpointed some buffers, released the mutex and
> > > > hung when trying to acquire it again in the next loop of
> > > > __log_wait_for_space()).
> > >
> > > And what's holding j_checkpoint mutex and not making progress?
> >
> > Waiting for wakeup from kjournald.
>
> So kicking the io in __log_wait_for_space()
>
> spin_unlock(&journal->j_state_lock);
>
> --> HERE
>
> mutex_lock(&journal->j_checkpoint_mutex);
>
> should fix the issue, right ?
Should for this scenario. Jan said he could think of ways to likely
make the same happen in xfs.
-Mike
next prev parent reply other threads:[~2012-07-16 10:13 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 [this message]
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
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
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=1342433585.7659.46.camel@marge.simpson.net \
--to=mgalbraith@novell.com \
--cc=jack@suse.cz \
--cc=jaxboe@fusionio.com \
--cc=jmoyer@redhat.com \
--cc=linux-fsdevel@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=mgalbraith@suse.com \
--cc=tglx@linutronix.de \
--cc=tj@kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).