linux-kernel - Re: [PATCH RFC] [x86] Optimize copy-page by reducing impact from HW prefetch

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Message-ID: <m2fwn13a3u.fsf@firstfloor.org>
Date:	Wed, 22 Jun 2011 13:05:41 -0700
From:	Andi Kleen <andi@...stfloor.org>
To:	ling.ma@...el.com
Cc:	mingo@...e.hu, hpa@...or.com, tglx@...utronix.de,
	linux-kernel@...r.kernel.org
Subject: Re: [PATCH RFC] [x86] Optimize copy-page by reducing impact from HW prefetch

ling.ma@...el.com writes:
> impact(DCU prefetcher), and simplify original code.
> The performance is improved about 15% on core2, 36% on snb respectively.
> (We use our micro-benchmark, and will do further test according to your requirment)

This doesn't make a lot of sense because neither Core-2 nor SNB use the
code path you patched. They all use the rep ; movs path

-Andi

-- 
ak@...ux.intel.com -- Speaking for myself only
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