On Mon, 2008-02-18 at 20:18 +0530, Balbir Singh wrote: > > Humm, the check that should have avoided that is: > > > > /* > > * Are we the only task in the tree? > > */ > > if (unlikely(rq->load.weight == curr->se.load.weight)) > > return; > > > > > > But I guess that overlooks rt tasks, they also increase the load. > > So I guess something like this ought to fix it.. > > > > Peter, > > I don't remember any real time tasks running on the system, so I would be > surprised if that is indeed the case.
Various kthreads have rt prio. Notably the load_balancer_monitor(). > Having said that, rightmost was indeed > NULL, so I need to figure out why it was. The other question is why would a > real > time task be found by sched_yield_fair? Because a rt task contributes weight and would make the test above fail because rt->load would be larger than expected. > > diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c > > index b9ade89..83eb30c 100644 > > --- a/kernel/sched_fair.c > > +++ b/kernel/sched_fair.c > > @@ -998,7 +998,7 @@ static void yield_task_fair(struct rq *rq) > > /* > > * Already in the rightmost position? > > */ > > - if (unlikely(rightmost->vruntime < se->vruntime)) > > + if (unlikely(!rightmost || rightmost->vruntime < se->vruntime)) > > return; > > > > /* > > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
