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Date: Mon, 24 Feb 2003 22:10:57 +0100
From: Andrea Arcangeli <andrea@suse.de>
To: Bill Huey <billh@gnuppy.monkey.org>
Cc: Andrew Morton <akpm@digeo.com>, wli@holomorphy.com, lm@work.bitmover.com,
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Subject: Re: Minutes from Feb 21 LSE Call
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On Mon, Feb 24, 2003 at 12:56:17AM -0800, Bill Huey wrote:
> On Mon, Feb 24, 2003 at 12:40:05AM -0800, Andrew Morton wrote:
> > There is no evidence for any such thing.  Nor has any plausible
> > theory been put forward as to why such an improvement should occur.
> 
> I find what you're saying a rather unbelievable given some of the
> benchmarks I saw when the preempt patch started to floating around.
> 
> If you search linuxdevices.com for articles on preempt, you'll see a
> claim about IO performance improvements with the patch. If somethings
> changed then I'd like to know.
> 
> The numbers are here:
> 	http://kpreempt.sourceforge.net/

most kernels out there are buggy w/o preempt. 2.4.21pre4aa3 has most of
the needed preemption checks in the kernel loops instead. It's quite
pointless to compare preempt with an otherwise buggy kernel.

Andrea
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