[<prev] [next>] [thread-next>] [day] [month] [year] [list]
Message-Id: <1194601672.20251.60.camel@ymzhang>
Date: Fri, 09 Nov 2007 17:47:52 +0800
From: "Zhang, Yanmin" <yanmin_zhang@...ux.intel.com>
To: a.p.zijlstra@...llo.nl
Cc: LKML <linux-kernel@...r.kernel.org>
Subject: iozone write 50% regression in kernel 2.6.24-rc1
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
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
Powered by blists - more mailing lists