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From: Fam Zheng <famz@redhat.com>
To: Alberto Garcia <berto@igalia.com>
Cc: Anton Nefedov <anton.nefedov@virtuozzo.com>,
	qemu-devel@nongnu.org, kwolf@redhat.com, qemu-block@nongnu.org,
	mreitz@redhat.com
Subject: Re: [Qemu-devel] [Qemu-block] segfault in parallel blockjobs (iotest 30)
Date: Fri, 10 Nov 2017 11:02:23 +0800	[thread overview]
Message-ID: <20171110030223.GA7303@lemon> (raw)
In-Reply-To: <w518tff4dvi.fsf@maestria.local.igalia.com>

On Thu, 11/09 17:26, Alberto Garcia wrote:
> On Wed 08 Nov 2017 03:45:38 PM CET, Alberto Garcia wrote:
> 
> > I'm thinking that perhaps we should add the pause point directly to
> > block_job_defer_to_main_loop(), to prevent any block job from running
> > the exit function when it's paused.
> 
> I was trying this and unfortunately this breaks the mirror job at least
> (reproduced with a simple block-commit on the topmost node, which uses
> commit_active_start() -> mirror_start_job()).
> 
> So what happens is that mirror_run() always calls bdrv_drained_begin()
> before returning, pausing the block job. The closing bdrv_drained_end()
> call is at the end of mirror_exit(), already in the main loop.
> 
> So the mirror job is always calling block_job_defer_to_main_loop() and
> mirror_exit() when the job is paused.
> 

FWIW, I think Max's report on 194 failures is related:

https://lists.gnu.org/archive/html/qemu-devel/2017-11/msg01822.html

so perhaps it's worth testing his patch too:

https://lists.gnu.org/archive/html/qemu-devel/2017-11/msg01835.html

Fam

  reply	other threads:[~2017-11-10  3:02 UTC|newest]

Thread overview: 21+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-11-07 16:19 [Qemu-devel] segfault in parallel blockjobs (iotest 30) Anton Nefedov
2017-11-08 13:58 ` [Qemu-devel] [Qemu-block] " Alberto Garcia
2017-11-08 14:45 ` Alberto Garcia
2017-11-08 15:50   ` Anton Nefedov
2017-11-09  6:05     ` Fam Zheng
2017-11-09 10:03       ` Alberto Garcia
2017-11-09 16:26   ` Alberto Garcia
2017-11-10  3:02     ` Fam Zheng [this message]
2017-11-15 15:42       ` Alberto Garcia
2017-11-15 16:31         ` Anton Nefedov
2017-11-16 15:54           ` Alberto Garcia
2017-11-16 16:09             ` Anton Nefedov
2017-11-21 12:51               ` Alberto Garcia
2017-11-21 15:18                 ` Anton Nefedov
2017-11-21 15:31                   ` Alberto Garcia
2017-11-22  0:13                     ` John Snow
2017-11-22 12:55                   ` Alberto Garcia
2017-11-22 15:58                     ` John Snow
2017-11-16 21:56             ` John Snow
2017-11-17 16:16               ` Alberto Garcia
2017-11-22 15:05 ` Alberto Garcia

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