From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <linux-kernel-owner@vger.kernel.org>
Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand
	id S932475AbcAKLMQ (ORCPT <rfc822;w@1wt.eu>);
	Mon, 11 Jan 2016 06:12:16 -0500
Received: from smtp02.citrix.com ([66.165.176.63]:50154 "EHLO
	SMTP02.CITRIX.COM" rhost-flags-OK-OK-OK-OK) by vger.kernel.org
	with ESMTP id S1759544AbcAKLMN (ORCPT
	<rfc822;linux-kernel@vger.kernel.org>);
	Mon, 11 Jan 2016 06:12:13 -0500
X-IronPort-AV: E=Sophos;i="5.20,552,1444694400"; 
   d="scan'208";a="330353750"
Message-ID: <56938E06.9050702@citrix.com>
Date: Mon, 11 Jan 2016 11:12:06 +0000
From: David Vrabel <david.vrabel@citrix.com>
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Icedove/31.8.0
MIME-Version: 1.0
To: "Michael S. Tsirkin" <mst@redhat.com>, <linux-kernel@vger.kernel.org>
CC: Peter Zijlstra <peterz@infradead.org>, Arnd Bergmann <arnd@arndb.de>,
        <linux-arch@vger.kernel.org>,
        Andrew Cooper <andrew.cooper3@citrix.com>,
        Russell King - ARM Linux <linux@arm.linux.org.uk>,
        <virtualization@lists.linux-foundation.org>,
        Stefano Stabellini <stefano.stabellini@eu.citrix.com>,
        Thomas Gleixner <tglx@linutronix.de>, Ingo Molnar <mingo@elte.hu>,
        "H. Peter Anvin" <hpa@zytor.com>, Joe Perches <joe@perches.com>,
        David Miller <davem@davemloft.net>, <linux-ia64@vger.kernel.org>,
        <linuxppc-dev@lists.ozlabs.org>, <linux-s390@vger.kernel.org>,
        <sparclinux@vger.kernel.org>, <linux-arm-kernel@lists.infradead.org>,
        <linux-metag@vger.kernel.org>, <linux-mips@linux-mips.org>,
        <x86@kernel.org>, <user-mode-linux-devel@lists.sourceforge.net>,
        <adi-buildroot-devel@lists.sourceforge.net>,
        <linux-sh@vger.kernel.org>, <linux-xtensa@linux-xtensa.org>,
        <xen-devel@lists.xenproject.org>,
        "Konrad Rzeszutek Wilk" <konrad.wilk@oracle.com>,
        Boris Ostrovsky <boris.ostrovsky@oracle.com>,
        Julien Grall <julien.grall@citrix.com>,
        "Ross Lagerwall" <ross.lagerwall@citrix.com>,
        Stefano Stabellini <stefano.stabellini@citrix.com>,
        Wei Liu <wei.liu2@citrix.com>
Subject: Re: [PATCH v3 39/41] xen/events: use virt_xxx barriers
References: <1452426622-4471-1-git-send-email-mst@redhat.com>
 <1452426622-4471-40-git-send-email-mst@redhat.com>
In-Reply-To: <1452426622-4471-40-git-send-email-mst@redhat.com>
Content-Type: text/plain; charset="windows-1252"
Content-Transfer-Encoding: 7bit
X-DLP: MIA2
Sender: linux-kernel-owner@vger.kernel.org
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org

On 10/01/16 14:21, Michael S. Tsirkin wrote:
> drivers/xen/events/events_fifo.c uses rmb() to communicate with the
> other side.
> 
> For guests compiled with CONFIG_SMP, smp_rmb would be sufficient, so
> rmb() here is only needed if a non-SMP guest runs on an SMP host.
> 
> Switch to the virt_rmb barrier which serves this exact purpose.
> 
> Pull in asm/barrier.h here to make sure the file is self-contained.
> 
> Suggested-by: David Vrabel <david.vrabel@citrix.com>
> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

Acked-by: David Vrabel <david.vrabel@citrix.com>

David