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From: "Marcin Gibuła" <m.gibula@beyond.pl>
To: qemu-devel@nongnu.org
Cc: kwolf@redhat.com, Paolo Bonzini <pbonzini@redhat.com>
Subject: Re: [Qemu-devel] qemu 2.0, deadlock in block-commit
Date: Fri, 23 May 2014 15:14:00 +0200	[thread overview]
Message-ID: <537F4998.8030805@beyond.pl> (raw)
In-Reply-To: <537F4156.8090105@beyond.pl>

>> bdrv_requests_pending(), called by bdrv_requests_pending_all(), is the
>> function that determines for each of the disks in your VM if it still
>> has requests in flight that need to be completed. This function must
>> have returned true even though there is nothing to wait for.
>>
>> Can you check which of its conditions led to this behaviour, and for
>> which disk it did? Either by setting a breakpoint there and
>> singlestepping through the function the next time it is called (if the
>> poll even has a timeout), or by inspecting the conditions manually in
>> gdb.

The condition that is true is:

if (!QLIST_EMPTY(&bs->tracked_requests))

and it's returned for intermediate qcow2 which is being commited.

-- 
mg

  reply	other threads:[~2014-05-23 13:14 UTC|newest]

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-05-22 20:49 [Qemu-devel] qemu 2.0, deadlock in block-commit Marcin Gibuła
2014-05-22 21:05 ` Marcin Gibuła
2014-05-23  8:19   ` Paolo Bonzini
2014-05-23  8:21     ` Marcin Gibuła
2014-05-23  9:25     ` Marcin Gibuła
2014-05-23 12:29       ` Kevin Wolf
2014-05-23 12:38         ` Marcin Gibuła
2014-05-23 13:14           ` Marcin Gibuła [this message]
2014-05-23 13:18             ` Marcin Gibuła
2014-05-23 22:02             ` Marcin Gibuła
2014-05-22 21:25 ` Eric Blake
2014-05-22 21:43   ` Marcin Gibuła
2014-05-23 12:58 ` Stefan Hajnoczi
2014-05-23 16:25   ` Marcin Gibuła

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