From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757428AbZEVWIv (ORCPT ); Fri, 22 May 2009 18:08:51 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1757588AbZEVWIo (ORCPT ); Fri, 22 May 2009 18:08:44 -0400 Received: from one.firstfloor.org ([213.235.205.2]:50168 "EHLO one.firstfloor.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757129AbZEVWIo (ORCPT ); Fri, 22 May 2009 18:08:44 -0400 Date: Sat, 23 May 2009 00:14:56 +0200 From: Andi Kleen To: Samuel Thibault , Andi Kleen , "Michael S. Zick" , linux-kernel@vger.kernel.org Subject: Re: [BUG FIX] Make x86_32 uni-processor Atomic ops, Atomic Message-ID: <20090522221456.GK846@one.firstfloor.org> References: <200905221139.26941.lkml@morethan.org> <200905221453.41895.lkml@morethan.org> <20090522200536.GZ10166@const.famille.thibault.fr> <200905221532.43775.lkml@morethan.org> <20090522204300.GA10166@const.famille.thibault.fr> <20090522215939.GI846@one.firstfloor.org> <20090522220049.GD10166@const.famille.thibault.fr> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20090522220049.GD10166@const.famille.thibault.fr> User-Agent: Mutt/1.4.2.1i Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > That's what I meant: AIUI, LOCK_PREFIX has always only been used for > inter-processor interaction (atomic variables, spinlocks, etc.), not for PCI has a locked transaction, but I don't think it's widely supported. With normal uncached access it is also not very useful. > processor-device interaction. Well in Linux yes, but not architecturally in x86. That is why the CPUs don't just nop it out with a single core (which Michael assumes they do, but they don't) -Andi -- ak@linux.intel.com -- Speaking for myself only.