On Fri, 2010-12-03 at 16:09 +0100, Mike Galbraith wrote: > On Fri, 2010-12-03 at 09:48 -0500, Rik van Riel wrote: > > On 12/03/2010 09:45 AM, Mike Galbraith wrote: > > > > > I'll have to go back and re-read that. Off the top of my head, I see no > > > way it could matter which container the numbers live in as long as they > > > keep advancing, and stay in the same runqueue. (hm, task weights would > > > have to be the same too or scaled. dangerous business, tinkering with > > > vruntimes) > > > > They're not necessarily in the same runqueue, the > > VCPU that is given time might be on another CPU > > than the one that was spinning on a lock. > > I don't think pumping vruntime cross cfs_rq would be safe, for the > reason noted (et al). No competition means vruntime is meaningless. > Donating just advances a clock that nobody's looking at. Yeah, cross-cpu you have to model it like exchanging lag. That's a slightly more complicated trick (esp. since we still don't have a proper measure for lag) but it should be doable. -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
