From mboxrd@z Thu Jan  1 00:00:00 1970
Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43)
	id 1M1Mip-0005Aj-Kx
	for qemu-devel@nongnu.org; Tue, 05 May 2009 11:38:19 -0400
Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43)
	id 1M1Mij-000543-PZ
	for qemu-devel@nongnu.org; Tue, 05 May 2009 11:38:18 -0400
Received: from [199.232.76.173] (port=49182 helo=monty-python.gnu.org)
	by lists.gnu.org with esmtp (Exim 4.43) id 1M1Mij-00053m-Hs
	for qemu-devel@nongnu.org; Tue, 05 May 2009 11:38:13 -0400
Received: from mail2.shareable.org ([80.68.89.115]:41704)
	by monty-python.gnu.org with esmtps (TLS-1.0:RSA_AES_256_CBC_SHA1:32)
	(Exim 4.60) (envelope-from <jamie@shareable.org>) id 1M1Mii-0008Bn-O3
	for qemu-devel@nongnu.org; Tue, 05 May 2009 11:38:12 -0400
Date: Tue, 5 May 2009 16:38:09 +0100
From: Jamie Lokier <jamie@shareable.org>
Subject: Re: [Qemu-devel] barriers: block layer preparations
Message-ID: <20090505153809.GC31100@shareable.org>
References: <20090505120804.GA30651@lst.de> <20090505120817.GA30721@lst.de>
	<4A00446B.7070404@redhat.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <4A00446B.7070404@redhat.com>
List-Id: qemu-devel.nongnu.org
List-Unsubscribe: <http://lists.nongnu.org/mailman/listinfo/qemu-devel>,
	<mailto:qemu-devel-request@nongnu.org?subject=unsubscribe>
List-Archive: <http://lists.gnu.org/pipermail/qemu-devel>
List-Post: <mailto:qemu-devel@nongnu.org>
List-Help: <mailto:qemu-devel-request@nongnu.org?subject=help>
List-Subscribe: <http://lists.nongnu.org/mailman/listinfo/qemu-devel>,
	<mailto:qemu-devel-request@nongnu.org?subject=subscribe>
To: Avi Kivity <avi@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>, qemu-devel@nongnu.org

Avi Kivity wrote:
> An alternative approach is to add a new op, bdrv_aio_barrier(), 
> submitted immediately after the write.  It's probably more complicated 
> overall.

Is it ok to submit a zero-length bdrv_aio_writev(), when you need a
barrier without data?

-- Jamie