Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754687AbZI3QNr (ORCPT ); Wed, 30 Sep 2009 12:13:47 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751936AbZI3QNr (ORCPT ); Wed, 30 Sep 2009 12:13:47 -0400 Received: from casper.infradead.org ([85.118.1.10]:42667 "EHLO casper.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751740AbZI3QNq (ORCPT ); Wed, 30 Sep 2009 12:13:46 -0400 Date: Wed, 30 Sep 2009 18:13:57 +0200 From: Arjan van de Ven To: Eric Dumazet Cc: Linus Torvalds , Martin Schwidefsky , Thomas Gleixner , John Stultz , Linux Kernel Mailing List , Peter Zijlstra , Ingo Molnar Subject: Re: Linux 2.6.32-rc1 Message-ID: <20090930181357.637bf8ec@infradead.org> In-Reply-To: <4AC37FE5.7020200@gmail.com> References: <4AC060AE.1090401@gmail.com> <20090928191506.40b61793@mschwide.boeblingen.de.ibm.com> <4AC10365.7090802@gmail.com> <4AC2712C.4080901@gmail.com> <20090929232248.735bf4df@infradead.org> <20090930170754.0886ff2e@infradead.org> <4AC37FE5.7020200@gmail.com> Organization: Intel X-Mailer: Claws Mail 3.7.2 (GTK+ 2.16.6; i586-redhat-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-SRS-Rewrite: SMTP reverse-path rewritten from by casper.infradead.org See http://www.infradead.org/rpr.html Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 817 Lines: 27 On Wed, 30 Sep 2009 17:57:25 +0200 Eric Dumazet wrote: > > Note: > > lock; cmpxchg8b (%%esi) > > gives 4 bytes opcode : f0 0f c7 0e > Because alternative (call cmpxchg8b_emu) uses 5 bytes, a nop will be > added. > > Choosing ".byte 0xf0, 0x0f, 0xc7, 0x4e, 0x00" aka "lock cmpxchg8b > 0x0(%esi)" is a litle bit better ? doesn't matter normally.. nops fall out quickly in the execution path ;) -- Arjan van de Ven Intel Open Source Technology Centre For development, discussion and tips for power savings, visit http://www.lesswatts.org -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/