Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757491Ab0GNTh1 (ORCPT ); Wed, 14 Jul 2010 15:37:27 -0400 Received: from terminus.zytor.com ([198.137.202.10]:43011 "EHLO mail.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752526Ab0GNThZ (ORCPT ); Wed, 14 Jul 2010 15:37:25 -0400 Message-ID: <4C3E11BD.2090503@zytor.com> Date: Wed, 14 Jul 2010 12:36:29 -0700 From: "H. Peter Anvin" User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.1.10) Gecko/20100621 Fedora/3.0.5-1.fc13 Thunderbird/3.0.5 MIME-Version: 1.0 To: "H.J. Lu" CC: Jeremy Fitzhardinge , Linus Torvalds , Peter Palfrader , Avi Kivity , Greg KH , linux-kernel@vger.kernel.org, stable@kernel.org, stable-review@kernel.org, akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, Glauber Costa , Zachary Amsden , Marcelo Tosatti Subject: Re: [patch 134/149] x86, paravirt: Add a global synchronization point for pvclock References: <20100707124731.GJ15122@anguilla.noreply.org> <20100713102350.GW15122@anguilla.noreply.org> <4C3C68C8.4060409@redhat.com> <20100713141902.GB15122@anguilla.noreply.org> <4C3C8CE5.1080705@redhat.com> <20100713162207.GC15122@anguilla.noreply.org> <4C3C9589.4090602@redhat.com> <4C3C96EC.8060901@redhat.com> <4C3C9839.4090404@redhat.com> <20100713172526.GE15122@anguilla.noreply.org> <4C3CAE8F.10900@goop.org> <4C3CE560.5050701@zytor.com> <4C3CFB8B.1090804@goop.org> <4C3DF1BE.2070404@goop.org> <4C3DF447.1000801@zytor.com> <4C3DF519.6030406@goop.org> <4C3DF7AF.7010402@zytor.com> <4C3DFA88.5020007@goop.org> <4C3DFD12.3050700@zytor.com> <4C3E096B.8050505@zytor.com> In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1070 Lines: 32 On 07/14/2010 12:32 PM, H.J. Lu wrote: > On Wed, Jul 14, 2010 at 12:00 PM, H. Peter Anvin wrote: >> On 07/14/2010 11:18 AM, H.J. Lu wrote: >>> >>> There are some discussions on: >>> >>> http://gcc.gnu.org/ml/gcc-patches/2010-06/msg02001.html >>> http://gcc.gnu.org/ml/gcc-patches/2010-07/msg00001.html >>> >>> Are they related? >>> >> >> Not directly as far as I can tell. >> >> The issue is if gcc can ever reorder, duplicate or elide a volatile >> operation (either asm volatile or a volatile-annotated memory >> reference.) In my (and Linus') opinion, this would be an incredibly >> serious bug. > > Is there a gcc bug for this? > Are you asking for a bug report against the documentation? We're not sure what the semantics intended by the gcc team to be, which I guess is a documentation bug. -hpa -- 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/