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From: Avi Kivity <avi@redhat.com>
To: qemu-devel@nongnu.org
Cc: Anthony Liguori <aliguori@us.ibm.com>, kvm-devel <kvm@vger.kernel.org>
Subject: Re: [Qemu-devel] [RFC] Replace posix-aio with custom thread pool
Date: Tue, 09 Dec 2008 19:16:51 +0200	[thread overview]
Message-ID: <493EA803.9060703@redhat.com> (raw)
In-Reply-To: <493E941D.4000608@redhat.com>

Gerd Hoffmann wrote:
> Well, I see a massive slowdown when switching from sync to aio in the
> xen backend code.  I think the reason is that due to the lack of a
> vectored interface (and thus /me submitting separate aio requests for
> each iovec element) stuff gets parallelized *way* too much and disk seek
> times are killing me.
>   

Try switching to the deadline io scheduler.  cfq has a known issue with 
this.

-- 
error compiling committee.c: too many arguments to function


  parent reply	other threads:[~2008-12-09 17:16 UTC|newest]

Thread overview: 75+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2008-12-05 21:21 [RFC] Replace posix-aio with custom thread pool Anthony Liguori
2008-12-05 21:21 ` [Qemu-devel] " Anthony Liguori
2008-12-06  9:03 ` Blue Swirl
2008-12-06 18:26   ` Jamie Lokier
2008-12-08 18:23   ` Anthony Liguori
2008-12-08 18:23     ` Anthony Liguori
2008-12-09 15:51 ` Gerd Hoffmann
2008-12-09 16:01   ` Anthony Liguori
2008-12-10 16:44     ` Andrea Arcangeli
2008-12-10 17:21       ` Anthony Liguori
2008-12-10 17:21         ` Anthony Liguori
2008-12-10 17:29         ` Gerd Hoffmann
2008-12-10 18:50           ` Anthony Liguori
2008-12-10 19:08             ` Andrea Arcangeli
2008-12-10 19:08               ` Andrea Arcangeli
2008-12-11 13:12               ` Andrea Arcangeli
2008-12-11 15:24                 ` Gerd Hoffmann
2008-12-11 15:24                   ` Gerd Hoffmann
2008-12-11 15:53                   ` Andrea Arcangeli
2008-12-11 15:53                     ` Andrea Arcangeli
2008-12-11 16:11                     ` Gerd Hoffmann
2008-12-11 16:11                       ` Gerd Hoffmann
2008-12-11 16:49                       ` Andrea Arcangeli
2008-12-11 16:49                         ` Andrea Arcangeli
2008-12-11 17:20                         ` Gerd Hoffmann
2008-12-11 17:20                           ` Gerd Hoffmann
2008-12-11 18:11                           ` Andrea Arcangeli
2008-12-11 18:11                             ` Andrea Arcangeli
2008-12-11 20:38                             ` Gerd Hoffmann
2008-12-11 20:38                               ` Gerd Hoffmann
2008-12-11 20:40                             ` Anthony Liguori
2008-12-12  8:23                             ` Jens Axboe
2008-12-12  8:23                               ` Jens Axboe
2008-12-12 11:51                               ` Andrea Arcangeli
2008-12-12 11:51                                 ` Andrea Arcangeli
2008-12-12 11:54                                 ` Jens Axboe
2008-12-12 11:54                                   ` Jens Axboe
2008-12-12 14:13                                   ` Andrea Arcangeli
2008-12-12 14:13                                     ` Andrea Arcangeli
2008-12-12 14:24                                     ` Anthony Liguori
2008-12-12 14:24                                       ` Anthony Liguori
2008-12-12 16:33                                       ` Chris Wright
2008-12-12 16:33                                         ` Chris Wright
2008-12-12 16:51                                         ` Anthony Liguori
2008-12-12 16:51                                           ` Anthony Liguori
2008-12-12 16:52                                           ` Chris Wright
2008-12-12 16:52                                             ` Chris Wright
2008-12-11 21:32                         ` Christoph Hellwig
2008-12-12  0:27                           ` Andrea Arcangeli
2008-12-12  0:27                             ` Andrea Arcangeli
2008-12-11 21:30                     ` Christoph Hellwig
2008-12-11 16:41                   ` Anthony Liguori
2008-12-11 16:41                     ` Anthony Liguori
2008-12-12 14:24               ` Andrea Arcangeli
2008-12-12 14:24                 ` Andrea Arcangeli
2008-12-12 14:35                 ` Anthony Liguori
2008-12-12 14:35                   ` Anthony Liguori
2008-12-12 15:44                   ` Andrea Arcangeli
2008-12-12 15:44                     ` Andrea Arcangeli
2008-12-12 16:49                     ` Anthony Liguori
2008-12-12 16:49                       ` Anthony Liguori
2008-12-12 17:09                       ` Andrea Arcangeli
2008-12-12 17:09                         ` Andrea Arcangeli
2008-12-12 17:25                         ` Anthony Liguori
2008-12-12 17:25                           ` Anthony Liguori
2008-12-12 17:52                           ` Andrea Arcangeli
2008-12-12 17:52                             ` Andrea Arcangeli
2008-12-12 18:17                             ` Anthony Liguori
2008-12-12 18:17                               ` Anthony Liguori
2008-12-12 18:26                               ` Andrea Arcangeli
2008-12-12 20:12                                 ` Gerd Hoffmann
2008-12-12 20:17                                   ` Anthony Liguori
2008-12-12 20:35                                     ` Gerd Hoffmann
2008-12-09 17:16   ` Avi Kivity [this message]
2008-12-17 14:44 ` Ian Jackson

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