From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753749AbZKHKTH (ORCPT ); Sun, 8 Nov 2009 05:19:07 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752808AbZKHKTF (ORCPT ); Sun, 8 Nov 2009 05:19:05 -0500 Received: from mx3.mail.elte.hu ([157.181.1.138]:54250 "EHLO mx3.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751500AbZKHKTD (ORCPT ); Sun, 8 Nov 2009 05:19:03 -0500 Date: Sun, 8 Nov 2009 11:18:56 +0100 From: Ingo Molnar To: Andi Kleen Cc: ling.ma@intel.com, hpa@zytor.com, tglx@linutronix.de, linux-kernel@vger.kernel.org Subject: Re: [PATCH RFC] [X86] performance improvement for memcpy_64.S by fast string. Message-ID: <20091108101856.GA7409@elte.hu> References: <1257500482-16182-1-git-send-email-ling.ma@intel.com> <87my2z7g1b.fsf@basil.nowhere.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <87my2z7g1b.fsf@basil.nowhere.org> User-Agent: Mutt/1.5.20 (2009-08-17) X-ELTE-SpamScore: 0.0 X-ELTE-SpamLevel: X-ELTE-SpamCheck: no X-ELTE-SpamVersion: ELTE 2.0 X-ELTE-SpamCheck-Details: score=0.0 required=5.9 tests=none autolearn=no SpamAssassin version=3.2.5 _SUMMARY_ Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org * Andi Kleen wrote: > ling.ma@intel.com writes: > > > Intel Nehalem improves the performance of REP strings significantly > > over previous microarchitectures in several ways: > > The problem is that it's not necessarily a win on older CPUs to do it > this way. I'm wondering, why are you writing such obtruse comments to Intel submitted patches? I know it and you know it too which older CPUs have a slow string implementation, and you know the rough order of magnitude and significance as well and you have ideas how to solve it all. Instead you injected just the minimal amount of information into this thread to derail this patch you can see a problem with, but you didnt at all explain your full opinion openly and honestly and you certainly didnt give enough information to allow Ling Ma to act upon your opinion with maximum efficiency. I.e. you are not being helpful at all here and you are obstructing Intel folks actively, making their workflow and progress as inefficient as you possibly can. Why are you doing that? Ingo