linux-raid.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Neil Brown <neilb@suse.de>
To: Tim Small <tim@seoss.co.uk>
Cc: "linux-raid@vger.kernel.org" <linux-raid@vger.kernel.org>
Subject: Re: Deadlock in md barrier code? / RAID1 / LVM CoW snapshot + ext3 / Debian 5.0 - lenny 2.6.26 kernel
Date: Tue, 19 Oct 2010 17:16:50 +1100	[thread overview]
Message-ID: <20101019171650.20c83e7e@notabene> (raw)
In-Reply-To: <4CBC9774.6020500@seoss.co.uk>

On Mon, 18 Oct 2010 19:52:36 +0100
Tim Small <tim@seoss.co.uk> wrote:

> Neil Brown wrote:
> > Maybe if you can get me a full sysrq-T list that might help.
> >    
> 
> At last, yes, courtesy of Ben Hutchings...
> 
> http://buttersideup.com/files/md-raid1-lockup-lvm-snapshot/deadlock-openvz-2.6.26-Debian5.txt

Thanks!

> 
> ... any use?

Only in as much as that it excludes some possible avenues of investigation,
which has some value.

But I'm out of ideas.  I cannot think of anything that could keep
->nr_pending or ->barrier elevated such that raise_barrier would
block for a long time.

Maybe you could try adding printks to print
  conf->{barrier,nr_pending,nr_waiting,nr_queued}
just before and after the second wait_event_lock_irq in raise_barrier().

That might help...

NeilBrown




> 
> Cheers,
> 
> Tim.
> 


  reply	other threads:[~2010-10-19  6:16 UTC|newest]

Thread overview: 21+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-09-17 14:53 Deadlock in md barrier code? / RAID1 / LVM CoW snapshot + ext3 / Debian 5.0 - lenny 2.6.26 kernel Tim Small
2010-09-17 22:59 ` Neil Brown
2010-09-20 19:59   ` Tim Small
2010-09-21 21:02     ` Tim Small
2010-09-21 22:30       ` Neil Brown
2010-10-12 13:59         ` Tim Small
2010-10-12 14:06         ` Tim Small
2010-10-12 16:48           ` CoolCold
2010-10-13  8:51             ` Tim Small
2010-10-13 13:00               ` CoolCold
2010-10-18 18:52         ` Tim Small
2010-10-19  6:16           ` Neil Brown [this message]
2010-10-19 16:24             ` Tim Small
2010-10-19 16:29               ` Tim Small
2010-10-19 19:29                 ` Tim Small
2010-10-20 20:34                   ` Tim Small
2010-10-20 23:04                     ` Neil Brown
2010-11-18 18:04                       ` Tim Small
2010-11-21 23:05                         ` Neil Brown
2010-12-06 15:42                           ` Tim Small
2010-09-21 22:21     ` Neil Brown

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=20101019171650.20c83e7e@notabene \
    --to=neilb@suse.de \
    --cc=linux-raid@vger.kernel.org \
    --cc=tim@seoss.co.uk \
    /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).