Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757177Ab0GMRZ2 (ORCPT ); Tue, 13 Jul 2010 13:25:28 -0400 Received: from anguilla.debian.or.at ([86.59.21.37]:51639 "EHLO anguilla.debian.or.at" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757103Ab0GMRZ1 (ORCPT ); Tue, 13 Jul 2010 13:25:27 -0400 Date: Tue, 13 Jul 2010 19:25:26 +0200 From: Peter Palfrader To: Avi Kivity Cc: Greg KH , linux-kernel@vger.kernel.org, stable@kernel.org, stable-review@kernel.org, torvalds@linux-foundation.org, akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, Glauber Costa , Zachary Amsden , Jeremy Fitzhardinge , Marcelo Tosatti Subject: Re: [patch 134/149] x86, paravirt: Add a global synchronization point for pvclock Message-ID: <20100713172526.GE15122@anguilla.noreply.org> Mail-Followup-To: Peter Palfrader , Avi Kivity , Greg KH , linux-kernel@vger.kernel.org, stable@kernel.org, stable-review@kernel.org, torvalds@linux-foundation.org, akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, Glauber Costa , Zachary Amsden , Jeremy Fitzhardinge , Marcelo Tosatti 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> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-15 Content-Disposition: inline In-Reply-To: <4C3C9839.4090404@redhat.com> X-PGP: 1024D/94C09C7F 5B00 C96D 5D54 AEE1 206B AF84 DE7A AF6E 94C0 9C7F X-Request-PGP: http://www.palfrader.org/keys/94C09C7F.asc X-Accept-Language: de, en User-Agent: Mutt/1.5.18 (2008-05-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1164 Lines: 31 On Tue, 13 Jul 2010, Avi Kivity wrote: > On 07/13/2010 07:40 PM, Avi Kivity wrote: >> On 07/13/2010 07:34 PM, Avi Kivity wrote: >>> >>> My bet is that dropping 'static' will fix it. We may have the wrong >>> constraints on atomic64_cmpxchg64(), so the compiler thinks we never >>> change last_value. >>> >> >> The constraints are there, but maybe the toolchain is confused. >> > > No they aren't, as Linus just pointed out. His patch should fix the > problem. Linus's patch touches __xchg() whereas we're using __cmpxchg() in this particular case I think. At least, applying it to my 2.6.32.16 tree didn't help, last_value was still read-only. Or I backported it wrong. -- | .''`. ** Debian GNU/Linux ** Peter Palfrader | : :' : The universal http://www.palfrader.org/ | `. `' Operating System | `- http://www.debian.org/ -- 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/