From mboxrd@z Thu Jan  1 00:00:00 1970
Received: from eggs.gnu.org ([2001:4830:134:3::10]:57848)
	by lists.gnu.org with esmtp (Exim 4.71)
	(envelope-from <famz@redhat.com>) id 1YsjQ2-0005h5-Vq
	for qemu-devel@nongnu.org; Wed, 13 May 2015 23:02:43 -0400
Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71)
	(envelope-from <famz@redhat.com>) id 1YsjQ2-0000cs-3i
	for qemu-devel@nongnu.org; Wed, 13 May 2015 23:02:42 -0400
Date: Thu, 14 May 2015 11:02:33 +0800
From: Fam Zheng <famz@redhat.com>
Message-ID: <20150514030233.GF862@ad.nay.redhat.com>
References: <1431538099-3286-1-git-send-email-famz@redhat.com>
	<1431538099-3286-12-git-send-email-famz@redhat.com>
	<555326ED.3050609@redhat.com>
	<20150513110843.GB30644@ad.nay.redhat.com>
	<5553369C.9010907@redhat.com>
	<20150513151715.GH30644@ad.nay.redhat.com>
	<55536CD6.5040008@redhat.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <55536CD6.5040008@redhat.com>
Subject: Re: [Qemu-devel] [PATCH v2 11/11] block: Block "device IO" during
 bdrv_drain and bdrv_drain_all
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: Paolo Bonzini <pbonzini@redhat.com>
Cc: Kevin Wolf <kwolf@redhat.com>, qemu-block@nongnu.org, qemu-devel@nongnu.org, jcody@redhat.com, armbru@redhat.com, mreitz@redhat.com, Stefan Hajnoczi <stefanha@redhat.com>

On Wed, 05/13 17:25, Paolo Bonzini wrote:
> 
> 
> On 13/05/2015 17:17, Fam Zheng wrote:
> >> > 
> >> > It can be the topic of a separate series.  But this patch brings a
> >> > false sense of security (either the blocker is unnecessary, or it
> >> > needs to last after bdrv_drain returns), so I think it should be
> >> > dropped.
> > Doesn't this let bdrv_drain_all return when virtio-blk-dataplane is having high
> > workload, in places where you say "the blocker is unnecessary"?
> 
> Yes, you're right.  Please document it in the commit message and the
> code, it's tricky.

OK, will do it.

Fam