On Wed, Jan 5, 2011 at 12:54 AM, Rik van Riel <riel@xxxxxxxxxx> wrote: > On 01/04/2011 11:51 AM, Hillf Danton wrote: > >>> Wouldn't that break for FIFO and RR tasks? >>> >>> There's a reason all the scheduler folks wanted a >>> per-class yield_to_task function :) >>> >> >> Where is the yield_to callback in the patch for RT schedule class? >> If @p is RT, what could you do? > > If the user chooses to overcommit the CPU with realtime > tasks, the user cannot expect realtime response. > > For realtime, I have not implemented the yield_to callback > at all because it would probably break realtime semantics > and I assume people will not overcommit the CPU with realtime > tasks anyway. > > I could see running a few realtime guests on a system, with > the number of realtime VCPUs not exceeding the number of > physical CPUs. > Then it looks curr->sched_class != p->sched_class is not enough, and yield_to can not ease the lock contention in KVM in case where p->rq->curr is RT. -- 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
