From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from SMTP02.CITRIX.COM (smtp02.citrix.com [66.165.176.63]) (using TLSv1 with cipher RC4-SHA (128/128 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id B63041A0D4E for ; Thu, 15 Jan 2015 21:54:58 +1100 (AEDT) Message-ID: <54B799DC.1050008@citrix.com> Date: Thu, 15 Jan 2015 10:43:40 +0000 From: David Vrabel MIME-Version: 1.0 To: Christian Borntraeger , 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" 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 on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , 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