From mboxrd@z Thu Jan 1 00:00:00 1970 From: Christian Borntraeger Date: Thu, 15 Jan 2015 11:07:11 +0000 Subject: Re: [Xen-devel] [PATCH 3/8] x86/xen/p2m: Replace ACCESS_ONCE with READ_ONCE Message-Id: <54B79F5F.1040806@de.ibm.com> List-Id: 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> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit 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?idX145) >> >> 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