sched/deadline: Add SCHED_DEADLINE inheritance logic

[mirror_ubuntu-artful-kernel.git] / kernel / sched / core.c

diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index aebcc70b5c93f79174a5885f26e0208f40240197..599ee3b11b443e6c39ea31be0643f967c7da1eaf 100644 (file)
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -947,7 +947,7 @@ static inline void check_class_changed(struct rq *rq, struct task_struct *p,
                if (prev_class->switched_from)
                        prev_class->switched_from(rq, p);
                p->sched_class->switched_to(rq, p);
-       } else if (oldprio != p->prio)
+       } else if (oldprio != p->prio || dl_task(p))
                p->sched_class->prio_changed(rq, p, oldprio);
 }
 
@@ -2781,7 +2781,7 @@ EXPORT_SYMBOL(sleep_on_timeout);
  */
 void rt_mutex_setprio(struct task_struct *p, int prio)
 {
-       int oldprio, on_rq, running;
+       int oldprio, on_rq, running, enqueue_flag = 0;
        struct rq *rq;
        const struct sched_class *prev_class;
 
@@ -2808,6 +2808,7 @@ void rt_mutex_setprio(struct task_struct *p, int prio)
        }
 
        trace_sched_pi_setprio(p, prio);
+       p->pi_top_task = rt_mutex_get_top_task(p);
        oldprio = p->prio;
        prev_class = p->sched_class;
        on_rq = p->on_rq;
@@ -2817,19 +2818,42 @@ void rt_mutex_setprio(struct task_struct *p, int prio)
        if (running)
                p->sched_class->put_prev_task(rq, p);
 
-       if (dl_prio(prio))
+       /*
+        * Boosting condition are:
+        * 1. -rt task is running and holds mutex A
+        *      --> -dl task blocks on mutex A
+        *
+        * 2. -dl task is running and holds mutex A
+        *      --> -dl task blocks on mutex A and could preempt the
+        *          running task
+        */
+       if (dl_prio(prio)) {
+               if (!dl_prio(p->normal_prio) || (p->pi_top_task &&
+                       dl_entity_preempt(&p->pi_top_task->dl, &p->dl))) {
+                       p->dl.dl_boosted = 1;
+                       p->dl.dl_throttled = 0;
+                       enqueue_flag = ENQUEUE_REPLENISH;
+               } else
+                       p->dl.dl_boosted = 0;
                p->sched_class = &dl_sched_class;
-       else if (rt_prio(prio))
+       } else if (rt_prio(prio)) {
+               if (dl_prio(oldprio))
+                       p->dl.dl_boosted = 0;
+               if (oldprio < prio)
+                       enqueue_flag = ENQUEUE_HEAD;
                p->sched_class = &rt_sched_class;
-       else
+       } else {
+               if (dl_prio(oldprio))
+                       p->dl.dl_boosted = 0;
                p->sched_class = &fair_sched_class;
+       }
 
        p->prio = prio;
 
        if (running)
                p->sched_class->set_curr_task(rq);
        if (on_rq)
-               enqueue_task(rq, p, oldprio < prio ? ENQUEUE_HEAD : 0);
+               enqueue_task(rq, p, enqueue_flag);
 
        check_class_changed(rq, p, prev_class, oldprio);
 out_unlock: