From: "Marcin Gibuła" <m.gibula@beyond.pl>
To: Stefan Hajnoczi <stefanha@redhat.com>, qemu-devel@nongnu.org
Cc: Kevin Wolf <kwolf@redhat.com>,
Paolo Bonzini <pbonzini@redhat.com>,
Ming Lei <ming.lei@canonical.com>
Subject: Re: [Qemu-devel] [PATCH] linux-aio: avoid deadlock in nested aio_poll() calls
Date: Mon, 04 Aug 2014 18:10:44 +0200 [thread overview]
Message-ID: <53DFB084.9040405@beyond.pl> (raw)
In-Reply-To: <1407167793-20425-1-git-send-email-stefanha@redhat.com>
W dniu 2014-08-04 17:56, Stefan Hajnoczi pisze:
> If two Linux AIO request completions are fetched in the same
> io_getevents() call, QEMU will deadlock if request A's callback waits
> for request B to complete using an aio_poll() loop. This was reported
> to happen with the mirror blockjob.
s/mirror/commit/
> This patch moves completion processing into a BH and makes it resumable.
> Nested event loops can resume completion processing so that request B
> will complete and the deadlock will not occur.
>
> Cc: Kevin Wolf <kwolf@redhat.com>
> Cc: Paolo Bonzini <pbonzini@redhat.com>
> Cc: Ming Lei <ming.lei@canonical.com>
> Cc: Marcin Gibuła <m.gibula@beyond.pl>
> Reported-by: Marcin Gibuła <m.gibula@beyond.pl>
> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
I'll test it tomorrow.
--
mg
next prev parent reply other threads:[~2014-08-04 16:11 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-08-04 15:56 [Qemu-devel] [PATCH] linux-aio: avoid deadlock in nested aio_poll() calls Stefan Hajnoczi
2014-08-04 16:10 ` Marcin Gibuła [this message]
2014-08-05 10:44 ` Ming Lei
2014-08-05 13:43 ` Stefan Hajnoczi
2014-08-05 14:26 ` Marcin Gibuła
2014-08-05 14:48 ` Marcin Gibuła
2014-08-05 17:33 ` Marcin Gibuła
2014-08-29 14:59 ` Stefan Hajnoczi
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