Subject: Re: [patch] voluntary-preempt-2.6.9-rc1-bk12-R6
From: Alan Cox <alan@lxorguk.ukuu.org.uk>
To: William Lee Irwin III <wli@holomorphy.com>
Cc: Andrew Morton <akpm@osdl.org>, Ingo Molnar <mingo@elte.hu>,
       rlrevell@joe-job.com,
       Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
       felipe_alfaro@linuxmail.org, mista.tapas@gmx.net, kr@cybsft.com,
       Mark_H_Johnson@Raytheon.com
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Date: Thu, 09 Sep 2004 23:11:39 +0100
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On Iau, 2004-09-09 at 23:45, William Lee Irwin III wrote:
> Something odd is going on, in part because I get *blistering* IO speeds
> running benchmarks like dbench, tiobench, et al on tmpfs with striped
> swap. In fact, IO speeds markedly faster than any other filesystem I've
> ever tried, by about 30MB/s (i.e. wirespeed, where others fall about
> 37.5% short of it). Virtual alignment issues do hurt, but the core
> allocation algorithm appears to be better than good, it's astounding.

Thats a very atypical load where you can expect to get long linear write
outs. The seek v write numbers for a disk nowdays have more in common
with a tape drive. Paging tends to be much much more random.

Alan

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