sched/deadline: Fix priority inheritance with multiple scheduling classes
[sfrench/cifs-2.6.git] / kernel / sched / deadline.c
index 6d93f451873493e9c0e61e749b462f0ca62e1d58..949bc5c083c136b5f36d6ee038387219179e8411 100644 (file)
@@ -43,6 +43,28 @@ static inline int on_dl_rq(struct sched_dl_entity *dl_se)
        return !RB_EMPTY_NODE(&dl_se->rb_node);
 }
 
+#ifdef CONFIG_RT_MUTEXES
+static inline struct sched_dl_entity *pi_of(struct sched_dl_entity *dl_se)
+{
+       return dl_se->pi_se;
+}
+
+static inline bool is_dl_boosted(struct sched_dl_entity *dl_se)
+{
+       return pi_of(dl_se) != dl_se;
+}
+#else
+static inline struct sched_dl_entity *pi_of(struct sched_dl_entity *dl_se)
+{
+       return dl_se;
+}
+
+static inline bool is_dl_boosted(struct sched_dl_entity *dl_se)
+{
+       return false;
+}
+#endif
+
 #ifdef CONFIG_SMP
 static inline struct dl_bw *dl_bw_of(int i)
 {
@@ -698,7 +720,7 @@ static inline void setup_new_dl_entity(struct sched_dl_entity *dl_se)
        struct dl_rq *dl_rq = dl_rq_of_se(dl_se);
        struct rq *rq = rq_of_dl_rq(dl_rq);
 
-       WARN_ON(dl_se->dl_boosted);
+       WARN_ON(is_dl_boosted(dl_se));
        WARN_ON(dl_time_before(rq_clock(rq), dl_se->deadline));
 
        /*
@@ -736,21 +758,20 @@ static inline void setup_new_dl_entity(struct sched_dl_entity *dl_se)
  * could happen are, typically, a entity voluntarily trying to overcome its
  * runtime, or it just underestimated it during sched_setattr().
  */
-static void replenish_dl_entity(struct sched_dl_entity *dl_se,
-                               struct sched_dl_entity *pi_se)
+static void replenish_dl_entity(struct sched_dl_entity *dl_se)
 {
        struct dl_rq *dl_rq = dl_rq_of_se(dl_se);
        struct rq *rq = rq_of_dl_rq(dl_rq);
 
-       BUG_ON(pi_se->dl_runtime <= 0);
+       BUG_ON(pi_of(dl_se)->dl_runtime <= 0);
 
        /*
         * This could be the case for a !-dl task that is boosted.
         * Just go with full inherited parameters.
         */
        if (dl_se->dl_deadline == 0) {
-               dl_se->deadline = rq_clock(rq) + pi_se->dl_deadline;
-               dl_se->runtime = pi_se->dl_runtime;
+               dl_se->deadline = rq_clock(rq) + pi_of(dl_se)->dl_deadline;
+               dl_se->runtime = pi_of(dl_se)->dl_runtime;
        }
 
        if (dl_se->dl_yielded && dl_se->runtime > 0)
@@ -763,8 +784,8 @@ static void replenish_dl_entity(struct sched_dl_entity *dl_se,
         * arbitrary large.
         */
        while (dl_se->runtime <= 0) {
-               dl_se->deadline += pi_se->dl_period;
-               dl_se->runtime += pi_se->dl_runtime;
+               dl_se->deadline += pi_of(dl_se)->dl_period;
+               dl_se->runtime += pi_of(dl_se)->dl_runtime;
        }
 
        /*
@@ -778,8 +799,8 @@ static void replenish_dl_entity(struct sched_dl_entity *dl_se,
         */
        if (dl_time_before(dl_se->deadline, rq_clock(rq))) {
                printk_deferred_once("sched: DL replenish lagged too much\n");
-               dl_se->deadline = rq_clock(rq) + pi_se->dl_deadline;
-               dl_se->runtime = pi_se->dl_runtime;
+               dl_se->deadline = rq_clock(rq) + pi_of(dl_se)->dl_deadline;
+               dl_se->runtime = pi_of(dl_se)->dl_runtime;
        }
 
        if (dl_se->dl_yielded)
@@ -812,8 +833,7 @@ static void replenish_dl_entity(struct sched_dl_entity *dl_se,
  * task with deadline equal to period this is the same of using
  * dl_period instead of dl_deadline in the equation above.
  */
-static bool dl_entity_overflow(struct sched_dl_entity *dl_se,
-                              struct sched_dl_entity *pi_se, u64 t)
+static bool dl_entity_overflow(struct sched_dl_entity *dl_se, u64 t)
 {
        u64 left, right;
 
@@ -835,9 +855,9 @@ static bool dl_entity_overflow(struct sched_dl_entity *dl_se,
         * of anything below microseconds resolution is actually fiction
         * (but still we want to give the user that illusion >;).
         */
-       left = (pi_se->dl_deadline >> DL_SCALE) * (dl_se->runtime >> DL_SCALE);
+       left = (pi_of(dl_se)->dl_deadline >> DL_SCALE) * (dl_se->runtime >> DL_SCALE);
        right = ((dl_se->deadline - t) >> DL_SCALE) *
-               (pi_se->dl_runtime >> DL_SCALE);
+               (pi_of(dl_se)->dl_runtime >> DL_SCALE);
 
        return dl_time_before(right, left);
 }
@@ -922,24 +942,23 @@ static inline bool dl_is_implicit(struct sched_dl_entity *dl_se)
  * Please refer to the comments update_dl_revised_wakeup() function to find
  * more about the Revised CBS rule.
  */
-static void update_dl_entity(struct sched_dl_entity *dl_se,
-                            struct sched_dl_entity *pi_se)
+static void update_dl_entity(struct sched_dl_entity *dl_se)
 {
        struct dl_rq *dl_rq = dl_rq_of_se(dl_se);
        struct rq *rq = rq_of_dl_rq(dl_rq);
 
        if (dl_time_before(dl_se->deadline, rq_clock(rq)) ||
-           dl_entity_overflow(dl_se, pi_se, rq_clock(rq))) {
+           dl_entity_overflow(dl_se, rq_clock(rq))) {
 
                if (unlikely(!dl_is_implicit(dl_se) &&
                             !dl_time_before(dl_se->deadline, rq_clock(rq)) &&
-                            !dl_se->dl_boosted)){
+                            !is_dl_boosted(dl_se))) {
                        update_dl_revised_wakeup(dl_se, rq);
                        return;
                }
 
-               dl_se->deadline = rq_clock(rq) + pi_se->dl_deadline;
-               dl_se->runtime = pi_se->dl_runtime;
+               dl_se->deadline = rq_clock(rq) + pi_of(dl_se)->dl_deadline;
+               dl_se->runtime = pi_of(dl_se)->dl_runtime;
        }
 }
 
@@ -1038,7 +1057,7 @@ static enum hrtimer_restart dl_task_timer(struct hrtimer *timer)
         * The task might have been boosted by someone else and might be in the
         * boosting/deboosting path, its not throttled.
         */
-       if (dl_se->dl_boosted)
+       if (is_dl_boosted(dl_se))
                goto unlock;
 
        /*
@@ -1066,7 +1085,7 @@ static enum hrtimer_restart dl_task_timer(struct hrtimer *timer)
         * but do not enqueue -- wait for our wakeup to do that.
         */
        if (!task_on_rq_queued(p)) {
-               replenish_dl_entity(dl_se, dl_se);
+               replenish_dl_entity(dl_se);
                goto unlock;
        }
 
@@ -1156,7 +1175,7 @@ static inline void dl_check_constrained_dl(struct sched_dl_entity *dl_se)
 
        if (dl_time_before(dl_se->deadline, rq_clock(rq)) &&
            dl_time_before(rq_clock(rq), dl_next_period(dl_se))) {
-               if (unlikely(dl_se->dl_boosted || !start_dl_timer(p)))
+               if (unlikely(is_dl_boosted(dl_se) || !start_dl_timer(p)))
                        return;
                dl_se->dl_throttled = 1;
                if (dl_se->runtime > 0)
@@ -1287,7 +1306,7 @@ throttle:
                        dl_se->dl_overrun = 1;
 
                __dequeue_task_dl(rq, curr, 0);
-               if (unlikely(dl_se->dl_boosted || !start_dl_timer(curr)))
+               if (unlikely(is_dl_boosted(dl_se) || !start_dl_timer(curr)))
                        enqueue_task_dl(rq, curr, ENQUEUE_REPLENISH);
 
                if (!is_leftmost(curr, &rq->dl))
@@ -1481,8 +1500,7 @@ static void __dequeue_dl_entity(struct sched_dl_entity *dl_se)
 }
 
 static void
-enqueue_dl_entity(struct sched_dl_entity *dl_se,
-                 struct sched_dl_entity *pi_se, int flags)
+enqueue_dl_entity(struct sched_dl_entity *dl_se, int flags)
 {
        BUG_ON(on_dl_rq(dl_se));
 
@@ -1493,9 +1511,9 @@ enqueue_dl_entity(struct sched_dl_entity *dl_se,
         */
        if (flags & ENQUEUE_WAKEUP) {
                task_contending(dl_se, flags);
-               update_dl_entity(dl_se, pi_se);
+               update_dl_entity(dl_se);
        } else if (flags & ENQUEUE_REPLENISH) {
-               replenish_dl_entity(dl_se, pi_se);
+               replenish_dl_entity(dl_se);
        } else if ((flags & ENQUEUE_RESTORE) &&
                  dl_time_before(dl_se->deadline,
                                 rq_clock(rq_of_dl_rq(dl_rq_of_se(dl_se))))) {
@@ -1512,19 +1530,7 @@ static void dequeue_dl_entity(struct sched_dl_entity *dl_se)
 
 static void enqueue_task_dl(struct rq *rq, struct task_struct *p, int flags)
 {
-       struct task_struct *pi_task = rt_mutex_get_top_task(p);
-       struct sched_dl_entity *pi_se = &p->dl;
-
-       /*
-        * Use the scheduling parameters of the top pi-waiter task if:
-        * - we have a top pi-waiter which is a SCHED_DEADLINE task AND
-        * - our dl_boosted is set (i.e. the pi-waiter's (absolute) deadline is
-        *   smaller than our deadline OR we are a !SCHED_DEADLINE task getting
-        *   boosted due to a SCHED_DEADLINE pi-waiter).
-        * Otherwise we keep our runtime and deadline.
-        */
-       if (pi_task && dl_prio(pi_task->normal_prio) && p->dl.dl_boosted) {
-               pi_se = &pi_task->dl;
+       if (is_dl_boosted(&p->dl)) {
                /*
                 * Because of delays in the detection of the overrun of a
                 * thread's runtime, it might be the case that a thread
@@ -1557,7 +1563,7 @@ static void enqueue_task_dl(struct rq *rq, struct task_struct *p, int flags)
                 * the throttle.
                 */
                p->dl.dl_throttled = 0;
-               BUG_ON(!p->dl.dl_boosted || flags != ENQUEUE_REPLENISH);
+               BUG_ON(!is_dl_boosted(&p->dl) || flags != ENQUEUE_REPLENISH);
                return;
        }
 
@@ -1594,7 +1600,7 @@ static void enqueue_task_dl(struct rq *rq, struct task_struct *p, int flags)
                return;
        }
 
-       enqueue_dl_entity(&p->dl, pi_se, flags);
+       enqueue_dl_entity(&p->dl, flags);
 
        if (!task_current(rq, p) && p->nr_cpus_allowed > 1)
                enqueue_pushable_dl_task(rq, p);
@@ -2787,11 +2793,14 @@ void __dl_clear_params(struct task_struct *p)
        dl_se->dl_bw                    = 0;
        dl_se->dl_density               = 0;
 
-       dl_se->dl_boosted               = 0;
        dl_se->dl_throttled             = 0;
        dl_se->dl_yielded               = 0;
        dl_se->dl_non_contending        = 0;
        dl_se->dl_overrun               = 0;
+
+#ifdef CONFIG_RT_MUTEXES
+       dl_se->pi_se                    = dl_se;
+#endif
 }
 
 bool dl_param_changed(struct task_struct *p, const struct sched_attr *attr)