Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755029Ab0GNTcp (ORCPT ); Wed, 14 Jul 2010 15:32:45 -0400 Received: from mail-pz0-f46.google.com ([209.85.210.46]:58357 "EHLO mail-pz0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752526Ab0GNTcn convert rfc822-to-8bit (ORCPT ); Wed, 14 Jul 2010 15:32:43 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :cc:content-type:content-transfer-encoding; b=Vejq93iNUd/4CQKAr8Qkg1hpjQMUgfNjR1A0vdu8HHoP+d1SREsPbv2+2OK1c8NJFw 91NbUqKL/xCFBbtQO+SqXvOe/MwPJb+e3aubg/Nfh0v8tHiwloFqHgh/Yg7RdwImFbQf H3HJKv2OA+JDP+XvKWPYK2Z+NX7dIccHJ3B4c= MIME-Version: 1.0 In-Reply-To: <4C3E096B.8050505@zytor.com> References: <20100707124731.GJ15122@anguilla.noreply.org> <4C359D5A.1050906@redhat.com> <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> Date: Wed, 14 Jul 2010 12:32:42 -0700 Message-ID: Subject: Re: [patch 134/149] x86, paravirt: Add a global synchronization point for pvclock From: "H.J. Lu" To: "H. Peter Anvin" 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 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 850 Lines: 31 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? -- H.J. -- 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/