From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Vrabel Subject: Re: [Xen-devel] [PATCH 3/8] x86/xen/p2m: Replace ACCESS_ONCE with READ_ONCE Date: Thu, 15 Jan 2015 10:43:40 +0000 Message-ID: <54B799DC.1050008@citrix.com> References: <1421312314-72330-1-git-send-email-borntraeger@de.ibm.com> <1421312314-72330-4-git-send-email-borntraeger@de.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset="windows-1252" Content-Transfer-Encoding: 8bit Return-path: In-Reply-To: <1421312314-72330-4-git-send-email-borntraeger@de.ibm.com> Sender: linux-kernel-owner@vger.kernel.org To: Christian Borntraeger , 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 List-Id: linux-arch.vger.kernel.org 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 Let me know if you want me to merge this via the Xen tree. David From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from smtp02.citrix.com ([66.165.176.63]:39789 "EHLO SMTP02.CITRIX.COM" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751537AbbAOKno (ORCPT ); Thu, 15 Jan 2015 05:43:44 -0500 Message-ID: <54B799DC.1050008@citrix.com> Date: Thu, 15 Jan 2015 10:43:40 +0000 From: David Vrabel 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> In-Reply-To: <1421312314-72330-4-git-send-email-borntraeger@de.ibm.com> Content-Type: text/plain; charset="windows-1252" Content-Transfer-Encoding: 8bit Sender: linux-arch-owner@vger.kernel.org List-ID: To: Christian Borntraeger , 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 Message-ID: <20150115104340.61iXSNmuKOmxI6F473aki0gfhqG2y_twXCC8X8iGRd4@z> 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 Let me know if you want me to merge this via the Xen tree. David