From mboxrd@z Thu Jan  1 00:00:00 1970
Received: from eggs.gnu.org ([140.186.70.92]:42326)
	by lists.gnu.org with esmtp (Exim 4.71) (envelope-from <hch@lst.de>)
	id 1RiTEX-0002Tn-Iz
	for qemu-devel@nongnu.org; Wed, 04 Jan 2012 10:58:34 -0500
Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71)
	(envelope-from <hch@lst.de>) id 1RiTES-0001rt-2y
	for qemu-devel@nongnu.org; Wed, 04 Jan 2012 10:58:33 -0500
Received: from verein.lst.de ([213.95.11.211]:59411 helo=newverein.lst.de)
	by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from <hch@lst.de>)
	id 1RiTER-0001rd-Um
	for qemu-devel@nongnu.org; Wed, 04 Jan 2012 10:58:28 -0500
Date: Wed, 4 Jan 2012 16:58:25 +0100
From: Christoph Hellwig <hch@lst.de>
Message-ID: <20120104155825.GA11210@lst.de>
References: <1313152395-25248-1-git-send-email-morita.kazutaka@lab.ntt.co.jp>
	<20111223133850.GA12770@lst.de> <20111229120626.GA32331@lst.de>
	<20111230103500.GA1740@stefanha-thinkpad.localdomain>
	<20120102153959.GA22823@lst.de>
	<20120103081655.GB28636@stefanha-thinkpad.localdomain>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <20120103081655.GB28636@stefanha-thinkpad.localdomain>
Subject: Re: [Qemu-devel] coroutine bug?,
	was Re: [PATCH] sheepdog: use	coroutines
List-Id: <qemu-devel.nongnu.org>
List-Unsubscribe: <https://lists.nongnu.org/mailman/options/qemu-devel>,
	<mailto:qemu-devel-request@nongnu.org?subject=unsubscribe>
List-Archive: <http://lists.nongnu.org/archive/html/qemu-devel>
List-Post: <mailto:qemu-devel@nongnu.org>
List-Help: <mailto:qemu-devel-request@nongnu.org?subject=help>
List-Subscribe: <https://lists.nongnu.org/mailman/listinfo/qemu-devel>,
	<mailto:qemu-devel-request@nongnu.org?subject=subscribe>
To: Stefan Hajnoczi <stefanha@gmail.com>
Cc: kwolf@redhat.com, sheepdog@lists.wpkg.org, Christoph Hellwig <hch@lst.de>, MORITA Kazutaka <morita.kazutaka@lab.ntt.co.jp>, qemu-devel@nongnu.org

On Tue, Jan 03, 2012 at 08:16:55AM +0000, Stefan Hajnoczi wrote:
> On Mon, Jan 02, 2012 at 04:39:59PM +0100, Christoph Hellwig wrote:
> > I've tried to understand how the recursive calling happens, but unfortunately
> > the whole coroutine code lacks any sort of documentation how it should
> > behave or what it asserts about the callers.
> 
> There is documentation on the public coroutine functions, see
> qemu-coroutine.h.

Ok, I was looking in the source files and the documentation directory only
as that is where I expected the documentation to sit.

Btw, what is the plan forward for the block I/O interface?  Only
qcow2, sheepdog and nbd implement the coroutine interfaces, and none of the
hardware emulations calls them directly.  Also at least for interfaces
like the librbd callbacks coroutines don't even seem to be that useful.