From mboxrd@z Thu Jan 1 00:00:00 1970 From: Diwaker Gupta Subject: Re: I/O descriptor ring size bottleneck? Date: Sun, 20 Mar 2005 16:06:38 -0800 Message-ID: <1b0b455705032016066e62d3b8@mail.gmail.com> References: Reply-To: Diwaker Gupta Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit In-Reply-To: Sender: xen-devel-admin@lists.sourceforge.net Errors-To: xen-devel-admin@lists.sourceforge.net List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , List-Archive: To: Ian Pratt Cc: xen-devel@lists.sourceforge.net, ian.pratt@cl.cam.ac.uk List-Id: xen-devel@lists.xenproject.org > BTW, I'd actually be very suspicious of dummynet's ability to operate at > 500Mb/s. It's possible that the reduced bandwidth is due to some bad > interaction between burstiness caused by Xen's context switching and > dummynet. Could you elaborate a bit more on this? Even if dummynet can't operate at 500Mbps, we should atleast see the same degradation in performance right? > Are your dom0 and domU running on the same processor? Could you try > using hyperthreading or SMP? Yep, same processor. For various other reasons, I wanted to avoid SMP, so I was running with the nosmp option. I'll try running with SMP and post an update. > Have you checked that domU <-> domU performance is good on the LAN with > a single TCP connection? I had a long time back, but I think that was with SMP. I'll check again. -- Diwaker Gupta http://resolute.ucsd.edu/diwaker ------------------------------------------------------- SF email is sponsored by - The IT Product Guide Read honest & candid reviews on hundreds of IT Products from real users. Discover which products truly live up to the hype. Start reading now. http://ads.osdn.com/?ad_id=6595&alloc_id=14396&op=click