From: Lukas Hejtmanek <xhejtman@ics.muni.cz>
To: "Jun'ichi Nomura" <j-nomura@ce.jp.nec.com>
Cc: Mike Snitzer <snitzer@redhat.com>,
Kiyoshi Ueda <k-ueda@ct.jp.nec.com>,
agk@redhat.com, linux-kernel@vger.kernel.org
Subject: Re: request baset device mapper in Linux
Date: Wed, 5 Oct 2011 12:35:45 +0200 [thread overview]
Message-ID: <20111005103545.GQ14063@ics.muni.cz> (raw)
In-Reply-To: <4E8C11B0.30000@ce.jp.nec.com>
On Wed, Oct 05, 2011 at 05:13:36PM +0900, Jun'ichi Nomura wrote:
> > yes, 3GB/s and only kwapd0 and kswapd1 is running, no kworker or ksoftirqd..
>
> Hmm.. did you find any difference in your profile this time?
not sure what do you mean.
> I'm trying to reproduce it myself but no success so far
> (perhaps disks are not fast enough to saturate CPU on my test machine).
hmm, I have 80 SAS 2.0 disks and two E5640 @ 2.67GHz cpus.
> As ksoftirqd in top implies your CPU4 gets too much I/O completions,
> 'rq_affnity = 2' for both dm and SCSI devices might be a solution.
> It'll distribute block completion softirqs to submitters and possibly
> reduce the loads of the 1st CPU in the socket.
> (See the commit below. It's a new feature of 3.1. Not available in 3.0...)
So what next? Should I try 3.1 kernel with this patch applied?
--
Lukáš Hejtmánek
next prev parent reply other threads:[~2011-10-05 10:36 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-07-20 8:26 request baset device mapper in Linux Lukas Hejtmanek
2011-07-21 11:11 ` Kiyoshi Ueda
2011-07-21 13:26 ` Lukas Hejtmanek
2011-07-22 6:56 ` Kiyoshi Ueda
2011-07-22 8:19 ` Lukas Hejtmanek
2011-07-23 7:28 ` Jun'ichi Nomura
2011-07-24 22:16 ` Lukas Hejtmanek
2011-08-01 9:31 ` Kiyoshi Ueda
2011-09-08 13:27 ` Lukas Hejtmanek
2011-09-15 18:49 ` Mike Snitzer
2011-09-16 14:08 ` Lukas Hejtmanek
2011-09-19 5:50 ` Jun'ichi Nomura
2011-09-29 20:57 ` Lukas Hejtmanek
2011-10-05 8:13 ` Jun'ichi Nomura
2011-10-05 10:35 ` Lukas Hejtmanek [this message]
2011-10-06 5:11 ` Jun'ichi Nomura
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