From: "Zhang, Yanmin" <yanmin_zhang@linux.intel.com>
To: Mark Lord <lkml@rtr.ca>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>,
LKML <linux-kernel@vger.kernel.org>
Subject: Re: iozone write 50% regression in kernel 2.6.24-rc1
Date: Tue, 13 Nov 2007 09:49:04 +0800 [thread overview]
Message-ID: <1194918544.20251.133.camel@ymzhang> (raw)
In-Reply-To: <47388C6C.4020903@rtr.ca>
On Mon, 2007-11-12 at 12:25 -0500, Mark Lord wrote:
> Peter Zijlstra wrote:
> ..
> > While I see that the write speed as reported under .24 ~70MB/s is much
> > lower than the one reported under .23 ~200MB/s, I find it very hard to
> > believe my poor single SATA disk could actually do the 200MB/s for
> > longer than its cache 8/16 MB (not sure).
> >
> > vmstat shows that actual IO is done, even though the whole 512MB could
> > fit in cache, hence my suspicion that the ~70MB/s is the most realistic
> > of the two.
> ..
>
> Yeah, sequential 70MB/sec is quite realistic for a modern SATA drive.
>
> But significantly faster than that (say, 100MB/sec +) is unlikely at present.
I just use command '#iozone -i 0 -r 4k -s 512m', no '-e -c'. So if
we consider cache, the speed is very fast. On my machine with 2.6.23, the write speed is
631M/s, quite fast. :)
next prev parent reply other threads:[~2007-11-13 1:50 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-11-09 9:47 iozone write 50% regression in kernel 2.6.24-rc1 Zhang, Yanmin
2007-11-09 9:54 ` 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 [this message]
-- 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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