Re: Stolen and degraded time and schedulers

Ingo Molnar
2007-03-16T08:40:47Z

* Jeremy Fitzhardinge <jeremy@goop.org> wrote:

> Ingo Molnar wrote:
> > touching the 'timer tick' is the wrong approach. 'stolen time' only
> > matters to the /scheduler tick/. So extend the hypervisor interface to
> > allow the injection of 'virtual' scheduler tick events: via the use of a
> > special clockevents device - do not change clockevents itself.
>
> I didn't. I was using sloppy terminology: I hang the stolen time
> accounting off the Xen timer interrupt routine, just so that it gets
> run every now and again.

i dont understand: how are you separating 'stolen time' drifts from
events generated for absolute timeouts?

> I suppose I could explicitly hook stolen time accounting into the
> scheduler, but its not obvious to me that it's necessary.

right now i dont see any clean way to solve this problem without having
two clockevents drivers: one for the scheduler, one for timer events.

Ingo