From: "Zhang, Yanmin" <yanmin_zhang@linux.intel.com>
To: a.p.zijlstra@chello.nl
Cc: LKML <linux-kernel@vger.kernel.org>
Subject: iozone write 50% regression in kernel 2.6.24-rc1
Date: Fri, 09 Nov 2007 17:47:52 +0800 [thread overview]
Message-ID: <1194601672.20251.60.camel@ymzhang> (raw)
Comparing with 2.6.23, iozone sequential write/rewrite (512M) has 50% regression
in kernel 2.6.24-rc1. 2.6.24-rc2 has the same regression.
My machine has 8 processor cores and 8GB memory.
By bisect, I located patch
http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commitdiff;h=04fbfdc14e5f48463820d6b9807daa5e9c92c51f.
Another behavior: with kernel 2.6.23, if I run iozone for many times after rebooting machine,
the result looks stable. But with 2.6.24-rc1, the first run of iozone got a very small result and
following run has 4Xorig_result.
What I reported is the regression of 2nd/3rd run, because first run has bigger regression.
I also tried to change /proc/sys/vm/dirty_ratio,dirty_backgroud_ratio and didn't get improvement.
-yanmin
next reply other threads:[~2007-11-09 9:49 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-11-09 9:47 Zhang, Yanmin [this message]
2007-11-09 9:54 ` iozone write 50% regression in kernel 2.6.24-rc1 Peter Zijlstra
2007-11-12 2:14 ` Zhang, Yanmin
2007-11-12 9:45 ` Peter Zijlstra
2007-11-12 9:51 ` Zhang, Yanmin
2007-11-12 13:26 ` Peter Zijlstra
[not found] ` <47386BC4.3050403@panasas.com>
2007-11-12 16:48 ` Peter Zijlstra
2007-11-13 2:19 ` Zhang, Yanmin
2007-11-13 8:34 ` Zhang, Yanmin
2007-11-13 18:32 ` Peter Zijlstra
2007-11-12 17:25 ` Mark Lord
2007-11-13 1:49 ` Zhang, Yanmin
-- strict thread matches above, loose matches on Subject: below --
2007-11-09 12:36 Martin Knoblauch
2007-11-12 0:45 ` Zhang, Yanmin
2007-11-12 12:58 Martin Knoblauch
2007-11-13 2:04 ` Zhang, Yanmin
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