From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756446Ab0GMRvY (ORCPT ); Tue, 13 Jul 2010 13:51:24 -0400 Received: from smtp1.linux-foundation.org ([140.211.169.13]:50387 "EHLO smtp1.linux-foundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751996Ab0GMRvX (ORCPT ); Tue, 13 Jul 2010 13:51:23 -0400 MIME-Version: 1.0 In-Reply-To: <20100713172526.GE15122@anguilla.noreply.org> 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> Date: Tue, 13 Jul 2010 10:50:46 -0700 Message-ID: Subject: Re: [patch 134/149] x86, paravirt: Add a global synchronization point for pvclock From: Linus Torvalds 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 Content-Type: multipart/mixed; boundary=000e0cd6a80e4457be048b488285 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --000e0cd6a80e4457be048b488285 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable On Tue, Jul 13, 2010 at 10:25 AM, Peter Palfrader wro= te: > > 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. =A0Or I backported it wrong. No, you didn't back-port it wrong. I just didn't fix the right part. I thought the PV code used xchg, not cmpxchg, so I only patched that. But cmpxchg has the exact same issue. Does this fix it? Again: UNTESTED. Linus --000e0cd6a80e4457be048b488285 Content-Type: application/octet-stream; name=diff Content-Disposition: attachment; filename=diff Content-Transfer-Encoding: base64 X-Attachment-Id: f_gbl1fe5v0 IGFyY2gveDg2L2luY2x1ZGUvYXNtL2NtcHhjaGdfNjQuaCB8ICAgMjggKysrKysrKysrKysrLS0t LS0tLS0tLS0tLS0tLQogMSBmaWxlcyBjaGFuZ2VkLCAxMiBpbnNlcnRpb25zKCspLCAxNiBkZWxl dGlvbnMoLSkKCmRpZmYgLS1naXQgYS9hcmNoL3g4Ni9pbmNsdWRlL2FzbS9jbXB4Y2hnXzY0Lmgg Yi9hcmNoL3g4Ni9pbmNsdWRlL2FzbS9jbXB4Y2hnXzY0LmgKaW5kZXggNDg1YWU0MS4uZjZmYWNl NyAxMDA2NDQKLS0tIGEvYXJjaC94ODYvaW5jbHVkZS9hc20vY21weGNoZ182NC5oCisrKyBiL2Fy Y2gveDg2L2luY2x1ZGUvYXNtL2NtcHhjaGdfNjQuaApAQCAtNzEsMjggKzcxLDI0IEBAIGV4dGVy biB2b2lkIF9fY21weGNoZ193cm9uZ19zaXplKHZvaWQpOwogCV9fdHlwZW9mX18oKihwdHIpKSBf X25ldyA9IChuZXcpOwkJCQlcCiAJc3dpdGNoIChzaXplKSB7CQkJCQkJCVwKIAljYXNlIDE6CQkJ CQkJCQlcCi0JCWFzbSB2b2xhdGlsZShsb2NrICJjbXB4Y2hnYiAlYjEsJTIiCQkJXAotCQkJICAg ICA6ICI9YSIoX19yZXQpCQkJCVwKLQkJCSAgICAgOiAicSIoX19uZXcpLCAibSIoKl9feGcocHRy KSksICIwIihfX29sZCkJXAotCQkJICAgICA6ICJtZW1vcnkiKTsJCQkJXAorCQlhc20gdm9sYXRp bGUobG9jayAiY21weGNoZ2IgJWIyLCUxIgkJCVwKKwkJCSAgICAgOiAiPWEiKF9fcmV0KSwgIitt IiAoKnB0cikJCQlcCisJCQkgICAgIDogInEiKF9fbmV3KSwgIjAiKF9fb2xkKSk7CQkJXAogCQli cmVhazsJCQkJCQkJXAogCWNhc2UgMjoJCQkJCQkJCVwKLQkJYXNtIHZvbGF0aWxlKGxvY2sgImNt cHhjaGd3ICV3MSwlMiIJCQlcCi0JCQkgICAgIDogIj1hIihfX3JldCkJCQkJXAotCQkJICAgICA6 ICJyIihfX25ldyksICJtIigqX194ZyhwdHIpKSwgIjAiKF9fb2xkKQlcCi0JCQkgICAgIDogIm1l bW9yeSIpOwkJCQlcCisJCWFzbSB2b2xhdGlsZShsb2NrICJjbXB4Y2hndyAldzIsJTEiCQkJXAor CQkJICAgICA6ICI9YSIoX19yZXQpLCAiK20iICgqcHRyKQkJCVwKKwkJCSAgICAgOiAiciIoX19u ZXcpLCAiMCIoX19vbGQpKTsJCQlcCiAJCWJyZWFrOwkJCQkJCQlcCiAJY2FzZSA0OgkJCQkJCQkJ XAotCQlhc20gdm9sYXRpbGUobG9jayAiY21weGNoZ2wgJWsxLCUyIgkJCVwKLQkJCSAgICAgOiAi PWEiKF9fcmV0KQkJCQlcCi0JCQkgICAgIDogInIiKF9fbmV3KSwgIm0iKCpfX3hnKHB0cikpLCAi MCIoX19vbGQpCVwKLQkJCSAgICAgOiAibWVtb3J5Iik7CQkJCVwKKwkJYXNtIHZvbGF0aWxlKGxv Y2sgImNtcHhjaGdsICVrMiwlMSIJCQlcCisJCQkgICAgIDogIj1hIihfX3JldCksICIrbSIgKCpw dHIpCQkJXAorCQkJICAgICA6ICJyIihfX25ldyksICIwIihfX29sZCkpOwkJCVwKIAkJYnJlYWs7 CQkJCQkJCVwKIAljYXNlIDg6CQkJCQkJCQlcCi0JCWFzbSB2b2xhdGlsZShsb2NrICJjbXB4Y2hn cSAlMSwlMiIJCQlcCi0JCQkgICAgIDogIj1hIihfX3JldCkJCQkJXAotCQkJICAgICA6ICJyIihf X25ldyksICJtIigqX194ZyhwdHIpKSwgIjAiKF9fb2xkKQlcCi0JCQkgICAgIDogIm1lbW9yeSIp OwkJCQlcCisJCWFzbSB2b2xhdGlsZShsb2NrICJjbXB4Y2hncSAlMiwlMSIJCQlcCisJCQkgICAg IDogIj1hIihfX3JldCksICIrbSIgKCpwdHIpCQkJXAorCQkJICAgICA6ICJyIihfX25ldyksICIw IihfX29sZCkpOwkJCVwKIAkJYnJlYWs7CQkJCQkJCVwKIAlkZWZhdWx0OgkJCQkJCQlcCiAJCV9f Y21weGNoZ193cm9uZ19zaXplKCk7CQkJCQlcCg== --000e0cd6a80e4457be048b488285--