From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1Fr1mD-0003TZ-H1 for qemu-devel@nongnu.org; Thu, 15 Jun 2006 20:01:29 -0400 Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1Fr1mB-0003TN-Du for qemu-devel@nongnu.org; Thu, 15 Jun 2006 20:01:28 -0400 Received: from [199.232.76.173] (helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1Fr1mB-0003TK-9o for qemu-devel@nongnu.org; Thu, 15 Jun 2006 20:01:27 -0400 Received: from [32.97.110.151] (helo=e33.co.us.ibm.com) by monty-python.gnu.org with esmtps (TLS-1.0:DHE_RSA_AES_256_CBC_SHA:32) (Exim 4.52) id 1Fr1vg-0002sm-Aw for qemu-devel@nongnu.org; Thu, 15 Jun 2006 20:11:16 -0400 Received: from westrelay02.boulder.ibm.com (westrelay02.boulder.ibm.com [9.17.195.11]) by e33.co.us.ibm.com (8.12.11.20060308/8.12.11) with ESMTP id k5G01P07016625 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK) for ; Thu, 15 Jun 2006 20:01:25 -0400 Received: from d03av01.boulder.ibm.com (d03av01.boulder.ibm.com [9.17.195.167]) by westrelay02.boulder.ibm.com (8.13.6/NCO/VER7.0) with ESMTP id k5G01AoY262566 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO) for ; Thu, 15 Jun 2006 18:01:10 -0600 Received: from d03av01.boulder.ibm.com (loopback [127.0.0.1]) by d03av01.boulder.ibm.com (8.12.11.20060308/8.13.3) with ESMTP id k5G01PGY028132 for ; Thu, 15 Jun 2006 18:01:25 -0600 Message-ID: <4491F4D2.1050803@us.ibm.com> Date: Thu, 15 Jun 2006 19:01:22 -0500 From: Anthony Liguori MIME-Version: 1.0 Subject: Re: [Qemu-devel] Doing a Tcl/Tk based frontend References: <1150357642.5679.7.camel@excellence.kicks-ass.net> <9b0d5f320606150618q25cd2b51v6a2ee6fc951f26b9@mail.gmail.com> <44916C36.50505@gmail.com> <4491C457.2080402@gmail.com> <4491DF66.2090304@gmx.de> <1150411933.3016.26.camel@mjolnir> <20060615232325.GA5198@redhat.com> <4491EE46.9070702@gmx.de> <20060615235623.GB5198@redhat.com> In-Reply-To: <20060615235623.GB5198@redhat.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Reply-To: qemu-devel@nongnu.org List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: "Daniel P. Berrange" , qemu-devel@nongnu.org Daniel P. Berrange wrote: >> VNC is a good idea... But isn't it a bit "laggy" for this purpose? I >> think people accept a laggy mouse cursor in a VNC window that comes over >> the network, but won't really accept that in virtual machine that's >> running directly on their desktop. OTOH, I'm no VNC expert :) and maybe >> there are tricks to speed this up?! >> > > There is no performance issue with native VNC on either localhost or > a LAN. That's not quite true. I did quite a bit of benchmarking with VNC localhost. I figure the best case scenario is raw encoding. Even with my very optimized client, there is a slight latency and more importantly, a non trivial CPU overhead (~5%) Basically, if you can't see the host cursor, you can't notice the cursor latency. The CPU overhead only adds a trivial amount of time when qemu is CPU bound. Certainly acceptable IMHO. I'm 100% it's the right approach to take. Regards, Anthony Liguori > I know of places where people use a VNC session to a remote > Linux desktop for day-to-day software development with no serious > performance issues. Basically if your network is reasonably fast then > there should be no issues. NB, I'm talking LAN - not WAN / Internet > here, so assuming 100mb ethernet. > > That said its possible that a combination of VNC, and slow emulation > of the display adapter within the guest OS could lower performance a > bit more, but I'm still fairly optimistic that its usable. In any > case slow display adapter emulation would affect the native SDL display > mode too. > > Dan >