From: Waiman Long <waiman.long@hp.com>
To: Chris Mason <clm@fb.com>
Cc: Marc Dionne <marc.c.dionne@gmail.com>,
Josef Bacik <jbacik@fb.com>,
linux-btrfs@vger.kernel.org, t-itoh@jp.fujitsu.com
Subject: Re: Lockups with btrfs on 3.16-rc1 - bisected
Date: Wed, 18 Jun 2014 23:21:31 -0400 [thread overview]
Message-ID: <53A2573B.1060901@hp.com> (raw)
In-Reply-To: <53A246C6.5050408@fb.com>
On 06/18/2014 10:11 PM, Chris Mason wrote:
> On 06/18/2014 10:03 PM, Marc Dionne wrote:
>> On Wed, Jun 18, 2014 at 8:41 PM, Marc Dionne<marc.c.dionne@gmail.com> wrote:
>>> On Wed, Jun 18, 2014 at 8:08 PM, Waiman Long<waiman.long@hp.com> wrote:
>>>> On 06/18/2014 08:03 PM, Marc Dionne wrote:
>> And for an additional data point, just removing those
>> CONFIG_DEBUG_LOCK_ALLOC ifdefs looks like it's sufficient to prevent
>> the symptoms when lockdep is not enabled.
> Ok, somehow we've added a lock inversion here that wasn't here before.
> Thanks for confirming, I'll nail it down.
>
> -chris
>
I am pretty sure that the hangup is caused by the following kind of code
fragment in the locking.c file:
if (eb->lock_nested) {
read_lock(&eb->lock);
if (eb->lock_nested && current->pid == eb->lock_owner) {
Is it possible to do the check without taking the read_lock?
-Longman
next prev parent reply other threads:[~2014-06-19 3:21 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-06-18 20:57 Lockups with btrfs on 3.16-rc1 - bisected Marc Dionne
2014-06-18 22:17 ` Waiman Long
2014-06-18 22:27 ` Josef Bacik
2014-06-18 22:47 ` Waiman Long
2014-06-18 23:10 ` Josef Bacik
2014-06-18 23:19 ` Waiman Long
2014-06-18 23:27 ` Chris Mason
2014-06-18 23:30 ` Waiman Long
2014-06-18 23:53 ` Chris Mason
2014-06-19 0:03 ` Marc Dionne
2014-06-19 0:08 ` Waiman Long
2014-06-19 0:41 ` Marc Dionne
2014-06-19 2:03 ` Marc Dionne
2014-06-19 2:11 ` Chris Mason
2014-06-19 3:21 ` Waiman Long [this message]
2014-06-19 16:51 ` Chris Mason
2014-06-19 17:52 ` Waiman Long
2014-06-19 20:10 ` Chris Mason
2014-06-19 21:50 ` Chris Mason
2014-06-19 23:21 ` Waiman Long
2014-06-20 3:20 ` Tsutomu Itoh
2014-06-21 1:09 ` Long, Wai Man
2014-06-19 9:49 ` btrfs-transacti:516 blocked 120 seconds on 3.16-rc1 Konstantinos Skarlatos
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