Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750714AbWBVVv4 (ORCPT ); Wed, 22 Feb 2006 16:51:56 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1750748AbWBVVv4 (ORCPT ); Wed, 22 Feb 2006 16:51:56 -0500 Received: from liaag1aa.mx.compuserve.com ([149.174.40.27]:3456 "EHLO liaag1aa.mx.compuserve.com") by vger.kernel.org with ESMTP id S1750714AbWBVVvz (ORCPT ); Wed, 22 Feb 2006 16:51:55 -0500 Date: Wed, 22 Feb 2006 16:45:45 -0500 From: Chuck Ebbert <76306.1226@compuserve.com> Subject: Re: [patch 5/6] lightweight robust futexes: i386 To: "Ulrich Drepper" Cc: linux-kernel , "Ulrich Drepper" , "Arjan van de Ven" , "Andrew Morton" , "Thomas Gleixner" , "Ingo Molnar" Message-ID: <200602221648_MC3-1-B90A-1A02@compuserve.com> MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1132 Lines: 31 In-Reply-To: On Tue, 21 Feb 2006 at 08:38:04 -0800, Ulrich Drepper wrote: > On 2/21/06, Chuck Ebbert <76306.1226@compuserve.com> wrote: > > > + : "=a" (oldval), "=m" (*uaddr) > > ^^^^ > > Should be "+m" because it's both read and written. > > No, this is why there is the "0" input parameter. But this is arg 1, not 0. With a memory clobber it's irrelevant anyway though. > > > + : "memory" > > ^^^^^^^^ > > Is this necessary? Every possible memory location that could be > > affected has been listed in the operands if the above change is made. > > This makes the asm a barrier for the compiler. A comment to that effect would be nice; IOW document the reason for it. -- Chuck "Equations are the Devil's sentences." --Stephen Colbert - 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/