From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754656AbZKIWhS (ORCPT ); Mon, 9 Nov 2009 17:37:18 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754054AbZKIWhR (ORCPT ); Mon, 9 Nov 2009 17:37:17 -0500 Received: from terminus.zytor.com ([198.137.202.10]:51764 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753738AbZKIWhR (ORCPT ); Mon, 9 Nov 2009 17:37:17 -0500 Message-ID: <4AF89989.2010402@zytor.com> Date: Mon, 09 Nov 2009 14:36:57 -0800 From: "H. Peter Anvin" User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.1.4pre) Gecko/20091014 Fedora/3.0-2.8.b4.fc11 Thunderbird/3.0b4 MIME-Version: 1.0 To: Andi Kleen CC: "Ma, Ling" , Ingo Molnar , Thomas Gleixner , linux-kernel Subject: Re: [PATCH RFC] [X86] performance improvement for memcpy_64.S by fast string. 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> <4AF7C66C.6000009@zytor.com> <87ws2059s9.fsf@basil.nowhere.org> <4AF84640.7010705@zytor.com> <20091109185434.GH26740@basil.fritz.box> In-Reply-To: <20091109185434.GH26740@basil.fritz.box> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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