From mboxrd@z Thu Jan  1 00:00:00 1970
Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43)
	id 1MTFGN-0003Q8-7v
	for qemu-devel@nongnu.org; Tue, 21 Jul 2009 09:20:11 -0400
Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43)
	id 1MTFGI-0003NP-AN
	for qemu-devel@nongnu.org; Tue, 21 Jul 2009 09:20:10 -0400
Received: from [199.232.76.173] (port=51859 helo=monty-python.gnu.org)
	by lists.gnu.org with esmtp (Exim 4.43) id 1MTFGI-0003NI-7g
	for qemu-devel@nongnu.org; Tue, 21 Jul 2009 09:20:06 -0400
Received: from mx2.redhat.com ([66.187.237.31]:54968)
	by monty-python.gnu.org with esmtp (Exim 4.60)
	(envelope-from <kraxel@redhat.com>) id 1MTFGH-00054R-ON
	for qemu-devel@nongnu.org; Tue, 21 Jul 2009 09:20:06 -0400
Message-ID: <4A65C07D.6080103@redhat.com>
Date: Tue, 21 Jul 2009 15:19:57 +0200
From: Gerd Hoffmann <kraxel@redhat.com>
MIME-Version: 1.0
Subject: Re: [Qemu-devel] Re: [PATCH] update server bits on vnc_update
References: <1247892434-21209-1-git-send-email-glommer@redhat.com>
	<4A6577A1.9010509@redhat.com>
	<alpine.DEB.2.00.0907211344260.12499@kaball-desktop>
In-Reply-To: <alpine.DEB.2.00.0907211344260.12499@kaball-desktop>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
Content-Transfer-Encoding: 7bit
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: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Cc: Glauber Costa <glommer@redhat.com>, "aliguori@us.ibm.com" <aliguori@us.ibm.com>, "qemu-devel@nongnu.org" <qemu-devel@nongnu.org>

On 07/21/09 14:56, Stefano Stabellini wrote:
> we call vga_hw_update in vnc_update_client, that means we call it once
> per vnc client connected! We should call it only once, probably in a
> separate timer, that is enabled only if at least one client is connect.

Good point.  Even better would be a timer shared by all clients, then 
loop over all clients (pretty much like vnc_dpy_update calls vnc_update 
for all connected clients).  That would make moving vga_hw_update out of 
the loop trivial ;)

> I also don't like the fact that we are allocating a server surface per
> client connected, this can become a problem very fast: I think we could
> probably get away with just one server surface for all the clients.

I don't think so.  server surface matches the vnc clients view of the 
framebuffer.  We need that to avoid sending screen updates for regions 
which didn't change.  Different clients can have a different views here 
for a number of reasons:  Because they support different feature sets. 
Because we try to skip frames if the pipe is full.  Thus sharing the 
server surface is non-trivial and we'll lose certain optimization when 
doing that.

cheers,
   Gerd