return false;
/*
- * FIFO realtime policy runs the highest priority task (after DEADLINE).
- * Other runnable tasks are of a lower priority. The scheduler tick
- * isn't needed.
- */
- fifo_nr_running = rq->rt.rt_nr_running - rq->rt.rr_nr_running;
- if (fifo_nr_running)
- return true;
-
- /*
- * Round-robin realtime tasks time slice with other tasks at the same
- * realtime priority.
+ * If there are more than one RR tasks, we need the tick to effect the
+ * actual RR behaviour.
*/
if (rq->rt.rr_nr_running) {
if (rq->rt.rr_nr_running == 1)
return false;
}
- /* Normal multitasking need periodic preemption checks */
- if (rq->cfs.nr_running > 1)
+ /*
+ * If there's no RR tasks, but FIFO tasks, we can skip the tick, no
+ * forced preemption between FIFO tasks.
+ */
+ fifo_nr_running = rq->rt.rt_nr_running - rq->rt.rr_nr_running;
+ if (fifo_nr_running)
+ return true;
+
+ /*
+ * If there are no DL,RR/FIFO tasks, there must only be CFS tasks left;
+ * if there's more than one we need the tick for involuntary
+ * preemption.
+ */
+ if (rq->nr_running > 1)
return false;
return true;
#endif
#endif
+static void sched_set_prio(struct task_struct *p, int prio)
+{
+ p->prio = prio;
+}
+
/*
* fork()/clone()-time setup:
*/
/*
* Make sure we do not leak PI boosting priority to the child.
*/
- p->prio = current->normal_prio;
+ sched_set_prio(p, current->normal_prio);
/*
* Revert to default priority/policy on fork if requested.
} else if (PRIO_TO_NICE(p->static_prio) < 0)
p->static_prio = NICE_TO_PRIO(0);
- p->prio = p->normal_prio = __normal_prio(p);
+ p->normal_prio = __normal_prio(p);
+ sched_set_prio(p, p->normal_prio);
set_load_weight(p);
/*
p->sched_class = &fair_sched_class;
}
- p->prio = prio;
+ sched_set_prio(p, prio);
if (running)
p->sched_class->set_curr_task(rq);
p->static_prio = NICE_TO_PRIO(nice);
set_load_weight(p);
old_prio = p->prio;
- p->prio = effective_prio(p);
+ sched_set_prio(p, effective_prio(p));
delta = p->prio - old_prio;
if (queued) {
* sched_setscheduler().
*/
if (keep_boost)
- p->prio = rt_mutex_get_effective_prio(p, normal_prio(p));
+ sched_set_prio(p, rt_mutex_get_effective_prio(p,
+ normal_prio(p)));
else
- p->prio = normal_prio(p);
+ sched_set_prio(p, normal_prio(p));
if (dl_prio(p->prio))
p->sched_class = &dl_sched_class;