From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1M1Mtt-0000I1-Up for qemu-devel@nongnu.org; Tue, 05 May 2009 11:49:46 -0400 Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1M1Mtp-0000Ct-6M for qemu-devel@nongnu.org; Tue, 05 May 2009 11:49:45 -0400 Received: from [199.232.76.173] (port=43084 helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1M1Mto-0000Cc-SL for qemu-devel@nongnu.org; Tue, 05 May 2009 11:49:40 -0400 Received: from mx2.redhat.com ([66.187.237.31]:52752) by monty-python.gnu.org with esmtp (Exim 4.60) (envelope-from ) id 1M1Mtn-0002IY-TI for qemu-devel@nongnu.org; Tue, 05 May 2009 11:49:40 -0400 Message-ID: <4A00600D.30502@redhat.com> Date: Tue, 05 May 2009 18:49:33 +0300 From: Avi Kivity MIME-Version: 1.0 Subject: Re: [Qemu-devel] barriers: block layer preparations References: <20090505120804.GA30651@lst.de> <20090505120817.GA30721@lst.de> <4A00446B.7070404@redhat.com> <20090505153809.GC31100@shareable.org> In-Reply-To: <20090505153809.GC31100@shareable.org> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Jamie Lokier Cc: Christoph Hellwig , qemu-devel@nongnu.org Jamie Lokier wrote: > 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? > We could make it so. But my point was to make barriers and writes orthogonal. -- error compiling committee.c: too many arguments to function