From: Andi Kleen <andi@firstfloor.org>
To: "H. Peter Anvin" <hpa@zytor.com>
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 10:26:14 +0100 [thread overview]
Message-ID: <87ws2059s9.fsf@basil.nowhere.org> (raw)
In-Reply-To: <4AF7C66C.6000009@zytor.com> (H. Peter Anvin's message of "Sun, 08 Nov 2009 23:36:12 -0800")
"H. Peter Anvin" <hpa@zytor.com> writes:
>
> My personal opinion is that if we can show no significant slowdown on
> P4, K8, P-M/Core 1, Core 2, and Nehalem then we can simply use this code
The issue is Core 2.
P4 uses a different path, and Core 1 doesn't use the 64bit code.
> unconditionally. If one of them is radically worse than baseline, then
> we have to do something conditional, which is a lot more complicated.
I have an older patchkit which did this, and some more optimizations
to this code.
There was still one open issue, that is why I didn't post it. If there's
interest I can post it.
-Andi
--
ak@linux.intel.com -- Speaking for myself only.
next prev parent reply other threads:[~2009-11-09 9:26 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 [this message]
2009-11-09 16:41 ` H. Peter Anvin
2009-11-09 18:54 ` Andi Kleen
2009-11-09 22:36 ` H. Peter Anvin
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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