From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755015AbZKLXDv (ORCPT ); Thu, 12 Nov 2009 18:03:51 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754926AbZKLXDu (ORCPT ); Thu, 12 Nov 2009 18:03:50 -0500 Received: from artax.karlin.mff.cuni.cz ([195.113.26.195]:48330 "EHLO artax.karlin.mff.cuni.cz" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754890AbZKLXDu (ORCPT ); Thu, 12 Nov 2009 18:03:50 -0500 Date: Thu, 12 Nov 2009 13:16:04 +0100 From: Pavel Machek To: "Ma, Ling" Cc: "H. Peter Anvin" , "mingo@elte.hu" , "tglx@linutronix.de" , "linux-kernel@vger.kernel.org" Subject: Re: [PATCH RFC] [X86] performance improvement for memcpy_64.S by fast string. Message-ID: <20091112121604.GC1394@ucw.cz> References: <1257500482-16182-1-git-send-email-ling.ma@intel.com> <4AF457E0.4040107@zytor.com> <4AF4784C.5090800@zytor.com> <8FED46E8A9CA574792FC7AACAC38FE7714FCF772C9@PDSMSX501.ccr.corp.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <8FED46E8A9CA574792FC7AACAC38FE7714FCF772C9@PDSMSX501.ccr.corp.intel.com> User-Agent: Mutt/1.5.18 (2008-05-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon 2009-11-09 15:24:03, Ma, Ling wrote: > Hi All > > Today we run our benchmark on Core2 and Sandy Bridge: > > 1. Retrieve result on Core2 > Speedup on Core2 > Len Alignement Speedup > 1024, 0/ 0: 0.95x > 2048, 0/ 0: 1.03x Well, so you are running cache hot and it is only a win on huge copies... how common are those? > Application run through perf > For (i= 1024; i < 1024 * 16; i = i + 64) > do_memcpy(0, 0, i); Pavel -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html