From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753624AbYCKQTe (ORCPT ); Tue, 11 Mar 2008 12:19:34 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752406AbYCKQTY (ORCPT ); Tue, 11 Mar 2008 12:19:24 -0400 Received: from mx2.mail.elte.hu ([157.181.151.9]:39411 "EHLO mx2.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752221AbYCKQTY (ORCPT ); Tue, 11 Mar 2008 12:19:24 -0400 Date: Tue, 11 Mar 2008 17:19:05 +0100 From: Ingo Molnar To: Mikael Pettersson Cc: tglx@linutronix.de, mingo@redhat.com, hpa@zytor.com, linux-kernel@vger.kernel.org Subject: Re: [PATCH 2.6.25-rc5] x86: correct/clarify comment in nops.h Message-ID: <20080311161901.GA32355@elte.hu> References: <18390.43171.335608.379379@harpo.it.uu.se> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <18390.43171.335608.379379@harpo.it.uu.se> User-Agent: Mutt/1.5.17 (2007-11-01) X-ELTE-VirusStatus: clean X-ELTE-SpamScore: -1.1 X-ELTE-SpamLevel: X-ELTE-SpamCheck: no X-ELTE-SpamVersion: ELTE 2.0 X-ELTE-SpamCheck-Details: score=-1.1 required=5.9 tests=BAYES_05 autolearn=no SpamAssassin version=3.2.3 -1.1 BAYES_05 BODY: Bayesian spam probability is 1 to 5% [score: 0.0147] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org * Mikael Pettersson wrote: > describes certain multibyte instructions as "generic" > nops when in fact they aren't nops at all in 64-bit mode (missing > REX.W causing truncation of a register). > > Update the comment to state that K8 or P6 style nops should be used in > 64-bit mode. This matches what the alternatives code does. > /* generic versions from gas > 1: nop > + the following instructions are NOT nops in 64-bit mode, > + for 64-bit mode use K8 or P6 nops instead > 2: movl %esi,%esi > 3: leal 0x00(%esi),%esi > 4: leal 0x00(,%esi,1),%esi thanks Mikael, applied. Ingo