From: "Miquel van Smoorenburg" <miquels@cistron.nl>
To: linux-kernel@vger.kernel.org
Subject: Re: Multi-threaded IO performance regression on 2.6 kernel?
Date: Thu, 21 Jul 2005 09:00:23 +0000 (UTC) [thread overview]
Message-ID: <dbno77$a6c$1@news.cistron.nl> (raw)
In-Reply-To: 1784BBD8D1F15B4C9FB0F09F0A939F9001A3E463@SZEXMTA4.amd.com
In article <1784BBD8D1F15B4C9FB0F09F0A939F9001A3E463@SZEXMTA4.amd.com>,
Xie, Bill <bill.xie@amd.com> wrote:
>All,
>
>I am testing the multi-threaded IO performance on Opteron servers.
>
>I use dd as the test tools. The single dd can reach 60MBps for single disk.
>
>on 2.6.5 kernel, If dd numbers exceed the CPU numbers, vmstat bi reduced
>to 20MBps.
>
>on 2.4.21 kernel, multi-threaded IO performance works fine, even I run
>40 dd command at same time.
>
>Does anybody experienced similar issue also?
First, use a more recent kernel, 2.6.11.x or 2.6.12.x. Then try if
changing the I/O scheduler (/sys/block/sda/queue/scheduler) to
deadline or cfq makes a difference.
I'm using 2.6.11.x and the cfq scheduler on most servers right now.
Mike.
prev parent reply other threads:[~2005-07-21 9:00 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2005-07-21 7:48 Multi-threaded IO performance regression on 2.6 kernel? Xie, Bill
2005-07-21 9:00 ` Miquel van Smoorenburg [this message]
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