From mboxrd@z Thu Jan 1 00:00:00 1970 From: Paul Dorman Subject: Re: xen affinity in an SMP system Date: Tue, 12 Oct 2004 07:23:08 +1300 Sender: xen-devel-admin@lists.sourceforge.net Message-ID: <200410120723.08911.pauld@cwa.co.nz> References: Mime-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: Content-Disposition: inline Errors-To: xen-devel-admin@lists.sourceforge.net List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , List-Archive: To: xen-devel@lists.sourceforge.net List-Id: xen-devel@lists.xenproject.org On Monday 11 October 2004 10:01 pm, Keir Fraser wrote: > > > As I understand it, a domain is tied to a specific CPU on startup, and > > > if it can be changed, it can only be changed manually. Is that right? > > > > Yup, it's changed manually using an xm command (probably "xm pincpu [dom] > > [cpu]" but I've never used it and could be wrong ;-). > > Yes, that works. > > > > Is it possible to have xen (or xend) check at regular intervals and > > > move a domain to another physical CPU depending on current load? > > > > Currently this isn't done but it's perfectly feasible. Sensible options > > are: 1) Have an scheduler in Xen that will migrate domains about at run > > time. 2) Have the load balancer task in Xend. > > Alternatively you could do it with a small external program. This > would poll either xend to get load stats for each domain, or could use > libxc directly. It would then talk to xend to re-pin appropriate > domains. > > A nice simple modular piece of functionality that would be easy to > maintain and modify. This is the approach I like for sure. It's much easier for someone like me (who isn't a low-level systems programmer) to write scripts to do this sort of stuff. I think you'll get much more community input this way too, and it doesn't negate the possibility of building load-balancing capabilities in at a later date. I intend to use a combination of tools on the VMs themselves, reporting back to a central control script, and whatever auxilliary information I can get from Xen and dom-0's proc. Paul ------------------------------------------------------- This SF.net email is sponsored by: IT Product Guide on ITManagersJournal Use IT products in your business? Tell us what you think of them. Give us Your Opinions, Get Free ThinkGeek Gift Certificates! Click to find out more http://productguide.itmanagersjournal.com/guidepromo.tmpl