From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tommi Virtanen Subject: Re: Serious performance issues Date: Mon, 07 Mar 2005 11:23:27 +0200 Message-ID: <422C1D8F.9090804@tv.debian.net> References: Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed 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 Ian Pratt wrote: > Are you using the standard bridging scripts? I guess not since your > bridge name is different. The only time I've seen something like this is > when some of the bridge timeout parameters are set to 0 jiffies (setting > to 1 jiffy is OK). I'm not. I had a fully working UML setup and wanted to share that between UML and Xen. The 0 jiffie thing was a good hint. That was the problem with bridge. I'm guessing I had that issue all along with my native linux setup. Summary: Problem #1: plugging in my Logitech USB trackball creates an uhci_hcd and timer interrupt storm that degrades performance to about 10% of normal. Unplug does not stop storm. Unknown cause, not fixed, workaround is not to plug in any USB device except hubs. Problem #2: bridge setfd/sethello 0 causes timer interrupt storm, but does not degrade performance significantly. Workaround is to not set such low numbers. Will talk to brctl/bridging maintainers to make it more foolproof. ------------------------------------------------------- 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