From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758217AbXI2QMZ (ORCPT ); Sat, 29 Sep 2007 12:12:25 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755898AbXI2QMM (ORCPT ); Sat, 29 Sep 2007 12:12:12 -0400 Received: from smtp2.linux-foundation.org ([207.189.120.14]:53552 "EHLO smtp2.linux-foundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754986AbXI2QML (ORCPT ); Sat, 29 Sep 2007 12:12:11 -0400 Date: Sat, 29 Sep 2007 09:11:10 -0700 (PDT) From: Linus Torvalds To: Nick Piggin cc: Paul McKenney , David Howells , Linux Kernel Mailing List , Andi Kleen Subject: Re: [rfc][patch] i386: remove comment about barriers In-Reply-To: <20070929132848.GA21169@wotan.suse.de> Message-ID: References: <20070929132848.GA21169@wotan.suse.de> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=us-ascii Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Sat, 29 Sep 2007, Nick Piggin wrote: > > OK this was going to be a quick patch, but after sleeping on it, I think > it deserves a better analysis... I can prove the comment is incorrect with a > test program, but I'm not as sure about my thinking that leads me to call it > also misleading. You're 100% right, that comment is total crap. An lfence is *not* a memory barrier, it's just a read memory barrier. Although on some microarchitectures they may of course end up being the same thing. Linus