* Srivatsa Vaddagiri ([email protected]) wrote: > On Fri, Dec 03, 2010 at 09:28:25AM -0800, Chris Wright wrote: > > * Srivatsa Vaddagiri ([email protected]) wrote: > > > On Thu, Dec 02, 2010 at 11:14:16AM -0800, Chris Wright wrote: > > > > Perhaps it should be a VM level option. And then invert the notion. > > > > Create one idle domain w/out hlt trap. Give that VM a vcpu per pcpu > > > > (pin in place probably). And have that VM do nothing other than hlt. > > > > Then it's always runnable according to scheduler, and can "consume" the > > > > extra work that CFS wants to give away. > > > > > > That's not sufficient. Lets we have 3 guests A, B, C that need to be > > > rate limited to 25% on a single cpu system. We create this idle guest > > > D that is 100% cpu hog as per above definition. Now when one of the > > > guest is idle, what ensures that the idle cycles of A is given only > > > to D and not partly to B/C? > > > > Yeah, I pictured priorties handling this. > > All guest are of equal priorty in this case (that's how we are able to divide > time into 25% chunks), so unless we dynamically boost D's priority based on > how > idle other VMs are, its not going to be easy!
Right, I think there has to be an external mgmt entity. Because num vcpus is not static. So priorities have to be rebalanaced at vcpu create/destroy time. thanks, -chris -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
