From: Jens Axboe <axboe@suse.de>
To: Keir Fraser <Keir.Fraser@cl.cam.ac.uk>
Cc: Ian Pratt <m+Ian.Pratt@cl.cam.ac.uk>,
Xen development list <xen-devel@lists.xensource.com>,
Kurt Garloff <garloff@suse.de>, Vincent Hanquez <tab@snarc.org>,
Christian Limpach <Christian.Limpach@cl.cam.ac.uk>
Subject: Re: poor domU VBD performance.
Date: Thu, 31 Mar 2005 10:19:01 +0200 [thread overview]
Message-ID: <20050331081900.GK9204@suse.de> (raw)
In-Reply-To: <63537e2b84ddbba6cb3d970f73c6ab35@cl.cam.ac.uk>
On Thu, Mar 31 2005, Keir Fraser wrote:
>
> On 31 Mar 2005, at 08:10, Jens Axboe wrote:
>
> >Here is a temporary work-around, this should bring you close to 100%
> >performance at the cost of some extra unplugs. Uncompiled.
>
> Yep, this does the job for me. Thanks! Avoiding the extra unplugs is
> harder than it sounds as each request in a batch may go to a different
> request queue. To minimise the number of unplugs per batch we'd need to
> add code to remember which queues we had used in the current batch,
> then kick them at the end of the batch. Is there likely to be any
Or just keep track of the previous queue, if that has changed unplug the
previous queue and update previous queue variable.
> measurable benefit from reducing the number of unplugs?
Probably not, since the plugging happened at the front end as well. So
you should get a nice stream of io in any way.
--
Jens Axboe
next prev parent reply other threads:[~2005-03-31 8:19 UTC|newest]
Thread overview: 64+ messages / expand[flat|nested] mbox.gz Atom feed top
2005-03-30 11:16 RE: RE: poor domU VBD performance Ian Pratt
2005-03-30 17:01 ` peter bier
2005-03-30 18:05 ` Andrew Theurer
2005-03-31 7:05 ` RE: " Jens Axboe
2005-03-31 7:10 ` Jens Axboe
2005-03-31 8:17 ` Keir Fraser
2005-03-31 8:19 ` Jens Axboe [this message]
2005-03-31 14:33 ` Philip R Auld
2005-03-31 15:34 ` Kurt Garloff
2005-03-31 15:39 ` Jens Axboe
2005-03-31 15:41 ` Jens Axboe
2005-03-31 16:27 ` Nivedita Singhvi
2005-03-31 17:43 ` Jens Axboe
2005-03-31 18:27 ` Kurt Garloff
2005-03-31 21:59 ` Nivedita Singhvi
2005-03-31 15:49 ` Keir Fraser
2005-03-31 16:02 ` Andrew Theurer
2005-03-31 17:44 ` Jens Axboe
2005-03-31 16:55 ` Philip R Auld
2005-03-31 16:53 ` Philip R Auld
2005-03-31 18:01 ` Jens Axboe
2005-03-31 18:43 ` Philip R Auld
2005-03-31 19:07 ` Keir Fraser
2005-03-31 19:10 ` Keir Fraser
2005-03-31 19:20 ` Jens Axboe
2005-03-31 19:21 ` Jens Axboe
-- strict thread matches above, loose matches on Subject: below --
2005-04-04 19:36 Ian Pratt
2005-04-04 22:35 ` Nicholas Lee
2005-04-12 10:29 ` peter bier
2005-04-02 10:56 Ian Pratt
2005-04-02 12:10 ` Cédric Schieli
2005-04-01 23:22 Ian Pratt
2005-04-02 10:36 ` Cédric Schieli
2005-04-02 19:54 ` peter bier
2005-03-31 22:36 Ian Pratt
2005-03-31 23:05 ` Andrew Theurer
2005-04-01 21:40 ` Cédric Schieli
2005-03-31 21:32 Ian Pratt
2005-03-31 22:13 ` Andrew Theurer
2005-03-31 17:55 Ian Pratt
2005-03-31 18:04 ` Jens Axboe
2005-03-31 18:57 ` Keir Fraser
2005-03-31 19:22 ` Jens Axboe
2005-03-31 20:49 ` Andrew Theurer
2005-03-31 21:15 ` Keir Fraser
2005-03-31 21:27 ` Andrew Theurer
2005-04-01 5:43 ` Jens Axboe
2005-04-01 16:36 ` peter bier
[not found] <A95E2296287EAD4EB592B5DEEFCE0E9D1E3905@liverpoolst.ad.cl.cam.ac.uk>
2005-03-29 22:45 ` RE: " Kurt Garloff
2005-03-29 22:59 ` Andrew Theurer
2005-03-29 23:19 ` Kurt Garloff
2005-03-29 23:26 ` Andrew Theurer
2005-03-29 14:19 Ian Pratt
2005-03-29 15:27 ` peter bier
2005-03-28 22:17 Ian Pratt
2005-03-29 8:44 ` peter bier
2005-03-28 20:14 Ian Pratt
2005-03-28 20:18 ` Andrew Theurer
2005-03-28 21:48 ` Andrew Theurer
2005-03-28 23:38 ` Peter Bier
2005-03-29 0:27 ` Andrew Theurer
2005-03-29 11:39 ` peter bier
2005-03-28 18:55 Ian Pratt
2005-03-28 19:33 ` Andrew Theurer
2005-03-27 17:41 Ian Pratt
2005-03-28 8:48 ` peter bier
2005-03-28 12:44 ` peter bier
2005-03-29 6:20 ` Pasi Kärkkäinen
2005-03-26 18:14 Peter Bier
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