From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wi0-f181.google.com (mail-wi0-f181.google.com [209.85.212.181]) by kanga.kvack.org (Postfix) with ESMTP id 2A7296B0032 for ; Thu, 15 Jan 2015 06:07:19 -0500 (EST) Received: by mail-wi0-f181.google.com with SMTP id hi2so16949591wib.2 for ; Thu, 15 Jan 2015 03:07:18 -0800 (PST) Received: from e06smtp15.uk.ibm.com (e06smtp15.uk.ibm.com. [195.75.94.111]) by mx.google.com with ESMTPS id cw8si9820770wib.27.2015.01.15.03.07.18 for (version=TLSv1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Thu, 15 Jan 2015 03:07:18 -0800 (PST) Received: from /spool/local by e06smtp15.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Thu, 15 Jan 2015 11:07:17 -0000 Received: from b06cxnps3074.portsmouth.uk.ibm.com (d06relay09.portsmouth.uk.ibm.com [9.149.109.194]) by d06dlp03.portsmouth.uk.ibm.com (Postfix) with ESMTP id BE1CE1B08061 for ; Thu, 15 Jan 2015 11:07:51 +0000 (GMT) Received: from d06av12.portsmouth.uk.ibm.com (d06av12.portsmouth.uk.ibm.com [9.149.37.247]) by b06cxnps3074.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id t0FB7EL262652580 for ; Thu, 15 Jan 2015 11:07:15 GMT Received: from d06av12.portsmouth.uk.ibm.com (localhost [127.0.0.1]) by d06av12.portsmouth.uk.ibm.com (8.14.4/8.14.4/NCO v10.0 AVout) with ESMTP id t0FB7Drt017632 for ; Thu, 15 Jan 2015 04:07:14 -0700 Message-ID: <54B79F5F.1040806@de.ibm.com> Date: Thu, 15 Jan 2015 12:07:11 +0100 From: Christian Borntraeger MIME-Version: 1.0 Subject: Re: [Xen-devel] [PATCH 3/8] x86/xen/p2m: Replace ACCESS_ONCE with READ_ONCE References: <1421312314-72330-1-git-send-email-borntraeger@de.ibm.com> <1421312314-72330-4-git-send-email-borntraeger@de.ibm.com> <54B799DC.1050008@citrix.com> In-Reply-To: <54B799DC.1050008@citrix.com> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: David Vrabel , linux-kernel@vger.kernel.org Cc: linux-arch@vger.kernel.org, kvm@vger.kernel.org, x86@kernel.org, kvm-ppc@vger.kernel.org, linux-mm@kvack.org, xen-devel@lists.xenproject.org, linuxppc-dev@lists.ozlabs.org Am 15.01.2015 um 11:43 schrieb David Vrabel: > On 15/01/15 08:58, Christian Borntraeger wrote: >> ACCESS_ONCE does not work reliably on non-scalar types. For >> example gcc 4.6 and 4.7 might remove the volatile tag for such >> accesses during the SRA (scalar replacement of aggregates) step >> (https://gcc.gnu.org/bugzilla/show_bug.cgi?id=58145) >> >> Change the p2m code to replace ACCESS_ONCE with READ_ONCE. > > Acked-by: David Vrabel Thanks > Let me know if you want me to merge this via the Xen tree. With your Acked-by, I can easily carry this in my tree. We can then ensure that this patch is merged before the ACCESS_ONCE is made stricter - making bisecting easier. Christian -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org