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From: "H. Peter Anvin" <hpa@zytor.com>
To: Andi Kleen <andi@firstfloor.org>
Cc: "Ma, Ling" <ling.ma@intel.com>, Ingo Molnar <mingo@redhat.com>,
	Thomas Gleixner <tglx@linutronix.de>,
	linux-kernel <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH RFC] [X86] performance improvement for memcpy_64.S by fast string.
Date: Mon, 09 Nov 2009 14:36:57 -0800	[thread overview]
Message-ID: <4AF89989.2010402@zytor.com> (raw)
In-Reply-To: <20091109185434.GH26740@basil.fritz.box>

On 11/09/2009 10:54 AM, Andi Kleen wrote:
>> Ling's numbers didn't seem to show a significant slowdown on Core 2 (it
>> was something like 0.95x baseline in the worst case, and most of the
>> cases were positive) so Core 2 doesn't seem to have a problem.
> 
> I ran quite a lot of micro benchmarks with various alignments and sizes
> the 'q' variant was not always a win. I haven't checked that particular
> version though.

Well, if you have concrete information about what the problem cases are,
then please provide it.  If you don't, but have a hunch where these
potential problems may lie, then please indicate what they might be.
Otherwise, there isn't any actionable information here.

	-hpa

  reply	other threads:[~2009-11-09 22:37 UTC|newest]

Thread overview: 33+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2009-11-06  9:41 [PATCH RFC] [X86] performance improvement for memcpy_64.S by fast string ling.ma
2009-11-06 16:51 ` Andi Kleen
2009-11-08 10:18   ` Ingo Molnar
2009-11-06 17:07 ` H. Peter Anvin
2009-11-06 19:26   ` H. Peter Anvin
2009-11-09  7:24     ` Ma, Ling
2009-11-09  7:36       ` H. Peter Anvin
2009-11-09  8:08         ` Ingo Molnar
2009-11-11  7:05           ` Ma, Ling
2009-11-11  7:18             ` Ingo Molnar
2009-11-11  7:57               ` Ma, Ling
2009-11-11 23:21                 ` H. Peter Anvin
2009-11-12  2:12                   ` Ma, Ling
2009-11-11 20:34             ` Cyrill Gorcunov
2009-11-11 22:39               ` H. Peter Anvin
2009-11-12  4:28                 ` Cyrill Gorcunov
2009-11-12  4:49                   ` Ma, Ling
2009-11-12  5:26                     ` H. Peter Anvin
2009-11-12  7:42                       ` Ma, Ling
2009-11-12  9:54                     ` Cyrill Gorcunov
2009-11-12 12:16           ` Pavel Machek
2009-11-13  7:33             ` Ingo Molnar
2009-11-13  8:04               ` H. Peter Anvin
2009-11-13  8:10                 ` Ingo Molnar
2009-11-09  9:26         ` Andi Kleen
2009-11-09 16:41           ` H. Peter Anvin
2009-11-09 18:54             ` Andi Kleen
2009-11-09 22:36               ` H. Peter Anvin [this message]
2009-11-12 12:16       ` Pavel Machek
2009-11-13  5:33         ` Ma, Ling
2009-11-13  6:04           ` H. Peter Anvin
2009-11-13  7:23             ` Ma, Ling
2009-11-13  7:30               ` H. Peter Anvin

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