From: Bernd Schubert <bernd.schubert@fastmail.fm>
To: mark delfman <markdelfman@googlemail.com>
Cc: Linux RAID Mailing List <linux-raid@vger.kernel.org>
Subject: Re: single cpu thread performance limit?
Date: Thu, 11 Aug 2011 21:04:12 +0200 [thread overview]
Message-ID: <4E4427AC.6070005@fastmail.fm> (raw)
In-Reply-To: <CAACGR8sSieD1MLCEnY0Wv24pHd9xpcJ=mhduwGMCqo5A5ttZpw@mail.gmail.com>
On 08/11/2011 05:58 PM, mark delfman wrote:
> I seem to have hit a significant hard stop in MD RAID1/10 performance
> which seems to be linked to a single CPU thread.
>
> I am using extremely high speed (IOPS) internal block devices – 8 in
> total. They are capable of achieving> 1million iops.
>
> However if I use RAID1 / 10 then MD seems to use a single thread which
> will reach 100% CPU utilisation (single core) at around 200K IOPS.
> Limiting the entire performance to around 200K.
>
Out of interest, could you please run "perf top" to let us see where the
kernel is busy?
Thanks,
Bernd
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prev parent reply other threads:[~2011-08-11 19:04 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-08-11 15:58 single cpu thread performance limit? mark delfman
2011-08-11 16:01 ` Mathias Burén
2011-08-11 16:07 ` mark delfman
2011-08-11 18:58 ` Stan Hoeppner
2011-08-11 19:37 ` mark delfman
2011-08-11 19:57 ` Joe Landman
2011-08-12 9:04 ` David Brown
2011-08-11 20:51 ` Stan Hoeppner
2011-08-12 1:05 ` Stan Hoeppner
2011-08-12 12:48 ` Asdo
2011-08-12 13:23 ` mark delfman
2011-08-12 14:23 ` Asdo
2011-08-12 20:51 ` Stan Hoeppner
2011-08-11 19:04 ` Bernd Schubert [this message]
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