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
next prev parent 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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