From: Anthony Liguori <anthony@codemonkey.ws>
To: qemu-devel@nongnu.org
Subject: Re: [Qemu-devel] [patch] Fix block I/O hang.
Date: Wed, 12 Nov 2008 08:57:45 -0600 [thread overview]
Message-ID: <491AEEE9.5010900@codemonkey.ws> (raw)
In-Reply-To: <491AD436.40908@redhat.com>
Gerd Hoffmann wrote:
> Anthony Liguori wrote:
>
>> Gerd Hoffmann wrote:
>>
>>> Hi,
>>>
>>> $subject says all.
>>>
>>> please apply,
>>> Gerd
>>>
>
>
>> Under what circumstances? posix_aio_read() is only invoked from a
>> select callback. This means there should be data available to be read.
>>
>
> Well, there are *two* select loops: main_loop_wait() and
> qemu_aio_wait(). Calling sync block i/o functions from a i/o handler
> causes the two select loops run nested => boom.
>
Yeah, qemu_aio_wait needs to die. Can you resubmit your patch with a
better description, and change the read() look in posix_aio_read() to
consume as much data as possible before hitting EAGAIN?
Regards,
Anthony Liguori
> cheers,
> Gerd
>
>
>
next prev parent reply other threads:[~2008-11-12 14:57 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-11-11 16:35 [Qemu-devel] [patch] Fix block I/O hang Gerd Hoffmann
2008-11-11 16:49 ` Anthony Liguori
2008-11-11 17:48 ` Gerd Hoffmann
2008-11-11 17:55 ` Anthony Liguori
2008-11-11 20:51 ` Gerd Hoffmann
2008-11-11 21:07 ` Anthony Liguori
2008-11-11 21:34 ` Gerd Hoffmann
2008-11-12 13:49 ` Johannes Stezenbach
2008-11-12 14:58 ` Anthony Liguori
2008-11-12 15:01 ` Gerd Hoffmann
2008-11-12 13:03 ` Gerd Hoffmann
2008-11-12 14:57 ` Anthony Liguori [this message]
2008-11-13 9:14 ` Gerd Hoffmann
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