From: Valdis.Kletnieks@vt.edu
To: Borislav Petkov <bp@alien8.de>
Cc: Ingo Molnar <mingo@elte.hu>, melwyn lobo <linux.melwyn@gmail.com>,
linux-kernel@vger.kernel.org, "H. Peter Anvin" <hpa@zytor.com>,
Thomas Gleixner <tglx@linutronix.de>,
Linus Torvalds <torvalds@linux-foundation.org>,
Peter Zijlstra <a.p.zijlstra@chello.nl>,
borislav.petkov@amd.com
Subject: Re: x86 memcpy performance
Date: Mon, 15 Aug 2011 22:34:35 -0400 [thread overview]
Message-ID: <6296.1313462075@turing-police.cc.vt.edu> (raw)
In-Reply-To: Your message of "Sun, 14 Aug 2011 11:59:10 +0200." <20110814095910.GA18809@liondog.tnic>
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On Sun, 14 Aug 2011 11:59:10 +0200, Borislav Petkov said:
> Benchmarking with 10000 iterations, average results:
> size XM MM speedup
> 119 540.58 449.491 0.8314969419
> 12273 2307.86 4042.88 1.751787902
> 13924 2431.8 4224.48 1.737184756
> 14335 2469.4 4218.82 1.708440514
> 15018 2675.67 1904.07 0.711622886
> 16374 2989.75 5296.26 1.771470902
> 24564 4262.15 7696.86 1.805863077
> 27852 4362.53 3347.72 0.7673805572
> 28672 5122.8 7113.14 1.388524413
> 30033 4874.62 8740.04 1.792967931
The numbers for 15018 and 27852 are *way* odd for the MM case. I don't feel
really good about this till we understand what happened for those two cases.
Also, anytime I see "10000 iterations", I ask myself if the benchmark rigging
took proper note of hot/cold cache issues. That *may* explain the two oddball
results we see above - but not knowing more about how it was benched, it's hard
to say.
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next prev parent reply other threads:[~2011-08-16 2:36 UTC|newest]
Thread overview: 40+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-08-12 17:59 melwyn lobo
2011-08-12 18:33 ` Andi Kleen
2011-08-12 19:52 ` Ingo Molnar
2011-08-14 9:59 ` Borislav Petkov
2011-08-14 11:13 ` Denys Vlasenko
2011-08-14 12:40 ` Borislav Petkov
2011-08-15 13:27 ` melwyn lobo
2011-08-15 13:44 ` Denys Vlasenko
2011-08-16 2:34 ` Valdis.Kletnieks [this message]
2011-08-16 12:16 ` Borislav Petkov
2011-09-01 15:15 ` Maarten Lankhorst
2011-09-01 16:18 ` Linus Torvalds
2011-09-08 8:35 ` Borislav Petkov
2011-09-08 10:58 ` Maarten Lankhorst
2011-09-09 8:14 ` Borislav Petkov
2011-09-09 10:12 ` Maarten Lankhorst
2011-09-09 11:23 ` Maarten Lankhorst
2011-09-09 13:42 ` Borislav Petkov
2011-09-09 14:39 ` Linus Torvalds
2011-09-09 15:35 ` Borislav Petkov
2011-12-05 12:20 ` melwyn lobo
2011-12-05 12:54 ` melwyn lobo
2011-12-05 14:36 ` Alan Cox
2011-08-15 14:55 Borislav Petkov
2011-08-15 14:59 ` Andy Lutomirski
2011-08-15 15:29 ` Borislav Petkov
2011-08-15 15:36 ` Andrew Lutomirski
2011-08-15 16:12 ` Borislav Petkov
2011-08-15 17:04 ` Andrew Lutomirski
2011-08-15 18:49 ` Borislav Petkov
2011-08-15 19:11 ` Andrew Lutomirski
2011-08-15 20:05 ` Borislav Petkov
2011-08-15 20:08 ` Andrew Lutomirski
2011-08-15 16:12 ` H. Peter Anvin
2011-08-15 16:58 ` Andrew Lutomirski
2011-08-15 18:26 ` H. Peter Anvin
2011-08-15 18:35 ` Andrew Lutomirski
2011-08-15 18:52 ` H. Peter Anvin
2011-08-16 7:19 ` melwyn lobo
2011-08-16 7:43 ` Borislav Petkov
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