Merge tag 'v3.16' into p/abusse/merge_upgrade
[projects/modsched/linux.git] / kernel / sched / cfs / rt.c
index bd2267a..a490831 100644 (file)
@@ -79,6 +79,8 @@ void init_rt_rq(struct rt_rq *rt_rq, struct rq *rq)
        rt_rq->overloaded = 0;
        plist_head_init(&rt_rq->pushable_tasks);
 #endif
+       /* We start is dequeued state, because no RT tasks are queued */
+       rt_rq->rt_queued = 0;
 
        rt_rq->rt_time = 0;
        rt_rq->rt_throttled = 0;
@@ -112,6 +114,13 @@ static inline struct rt_rq *rt_rq_of_se(struct sched_rt_entity *rt_se)
        return rt_se->rt_rq;
 }
 
+static inline struct rq *rq_of_rt_se(struct sched_rt_entity *rt_se)
+{
+       struct rt_rq *rt_rq = rt_se->rt_rq;
+
+       return rt_rq->rq;
+}
+
 void free_rt_sched_group(struct task_group *tg)
 {
        int i;
@@ -211,10 +220,16 @@ static inline struct rq *rq_of_rt_rq(struct rt_rq *rt_rq)
        return container_of(rt_rq, struct rq, rt);
 }
 
-static inline struct rt_rq *rt_rq_of_se(struct sched_rt_entity *rt_se)
+static inline struct rq *rq_of_rt_se(struct sched_rt_entity *rt_se)
 {
        struct task_struct *p = rt_task_of(rt_se);
-       struct rq *rq = task_rq(p);
+
+       return task_rq(p);
+}
+
+static inline struct rt_rq *rt_rq_of_se(struct sched_rt_entity *rt_se)
+{
+       struct rq *rq = rq_of_rt_se(rt_se);
 
        return &rq->rt;
 }
@@ -391,6 +406,9 @@ static inline void set_post_schedule(struct rq *rq)
 }
 #endif /* CONFIG_SMP */
 
+static void enqueue_top_rt_rq(struct rt_rq *rt_rq);
+static void dequeue_top_rt_rq(struct rt_rq *rt_rq);
+
 static inline int on_rt_rq(struct sched_rt_entity *rt_se)
 {
        return !list_empty(&rt_se->run_list);
@@ -452,8 +470,11 @@ static void sched_rt_rq_enqueue(struct rt_rq *rt_rq)
        rt_se = rt_rq->tg->rt_se[cpu];
 
        if (rt_rq->rt_nr_running) {
-               if (rt_se && !on_rt_rq(rt_se))
+               if (!rt_se)
+                       enqueue_top_rt_rq(rt_rq);
+               else if (!on_rt_rq(rt_se))
                        enqueue_rt_entity(rt_se, false);
+
                if (rt_rq->highest_prio.curr < curr->prio)
                        resched_task(curr);
        }
@@ -466,10 +487,17 @@ static void sched_rt_rq_dequeue(struct rt_rq *rt_rq)
 
        rt_se = rt_rq->tg->rt_se[cpu];
 
-       if (rt_se && on_rt_rq(rt_se))
+       if (!rt_se)
+               dequeue_top_rt_rq(rt_rq);
+       else if (on_rt_rq(rt_se))
                dequeue_rt_entity(rt_se);
 }
 
+static inline int rt_rq_throttled(struct rt_rq *rt_rq)
+{
+       return rt_rq->rt_throttled && !rt_rq->rt_nr_boosted;
+}
+
 static int rt_se_boosted(struct sched_rt_entity *rt_se)
 {
        struct rt_rq *rt_rq = group_rt_rq(rt_se);
@@ -532,12 +560,23 @@ static inline struct rt_rq *group_rt_rq(struct sched_rt_entity *rt_se)
 
 static inline void sched_rt_rq_enqueue(struct rt_rq *rt_rq)
 {
-       if (rt_rq->rt_nr_running)
-               resched_task(rq_of_rt_rq(rt_rq)->curr);
+       struct rq *rq = rq_of_rt_rq(rt_rq);
+
+       if (!rt_rq->rt_nr_running)
+               return;
+
+       enqueue_top_rt_rq(rt_rq);
+       resched_task(rq->curr);
 }
 
 static inline void sched_rt_rq_dequeue(struct rt_rq *rt_rq)
 {
+       dequeue_top_rt_rq(rt_rq);
+}
+
+static inline int rt_rq_throttled(struct rt_rq *rt_rq)
+{
+       return rt_rq->rt_throttled;
 }
 
 static inline const struct cpumask *sched_rt_period_mask(void)
@@ -851,14 +890,8 @@ static int sched_rt_runtime_exceeded(struct rt_rq *rt_rq)
                 * but accrue some time due to boosting.
                 */
                if (likely(rt_b->rt_runtime)) {
-                       static bool once = false;
-
                        rt_rq->rt_throttled = 1;
-
-                       if (!once) {
-                               once = true;
-                               printk_sched("sched: RT throttling activated\n");
-                       }
+                       printk_deferred_once("sched: RT throttling activated\n");
                } else {
                        /*
                         * In case we did anyway, make it go away,
@@ -885,7 +918,6 @@ static void update_curr_rt(struct rq *rq)
 {
        struct task_struct *curr = rq->curr;
        struct sched_rt_entity *rt_se = &curr->rt;
-       struct rt_rq *rt_rq = rt_rq_of_se(rt_se);
        u64 delta_exec;
 
        if (curr->sched_class != &rt_sched_class)
@@ -910,7 +942,7 @@ static void update_curr_rt(struct rq *rq)
                return;
 
        for_each_sched_rt_entity(rt_se) {
-               rt_rq = rt_rq_of_se(rt_se);
+               struct rt_rq *rt_rq = rt_rq_of_se(rt_se);
 
                if (sched_rt_runtime(rt_rq) != RUNTIME_INF) {
                        raw_spin_lock(&rt_rq->rt_runtime_lock);
@@ -922,6 +954,38 @@ static void update_curr_rt(struct rq *rq)
        }
 }
 
+static void
+dequeue_top_rt_rq(struct rt_rq *rt_rq)
+{
+       struct rq *rq = rq_of_rt_rq(rt_rq);
+
+       BUG_ON(&rq->rt != rt_rq);
+
+       if (!rt_rq->rt_queued)
+               return;
+
+       BUG_ON(!rq->nr_running);
+
+       sub_nr_running(rq, rt_rq->rt_nr_running);
+       rt_rq->rt_queued = 0;
+}
+
+static void
+enqueue_top_rt_rq(struct rt_rq *rt_rq)
+{
+       struct rq *rq = rq_of_rt_rq(rt_rq);
+
+       BUG_ON(&rq->rt != rt_rq);
+
+       if (rt_rq->rt_queued)
+               return;
+       if (rt_rq_throttled(rt_rq) || !rt_rq->rt_nr_running)
+               return;
+
+       add_nr_running(rq, rt_rq->rt_nr_running);
+       rt_rq->rt_queued = 1;
+}
+
 #if defined CONFIG_SMP
 
 static void
@@ -1044,13 +1108,24 @@ void dec_rt_group(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq) {}
 
 #endif /* CONFIG_RT_GROUP_SCHED */
 
+static inline
+unsigned int rt_se_nr_running(struct sched_rt_entity *rt_se)
+{
+       struct rt_rq *group_rq = group_rt_rq(rt_se);
+
+       if (group_rq)
+               return group_rq->rt_nr_running;
+       else
+               return 1;
+}
+
 static inline
 void inc_rt_tasks(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq)
 {
        int prio = rt_se_prio(rt_se);
 
        WARN_ON(!rt_prio(prio));
-       rt_rq->rt_nr_running++;
+       rt_rq->rt_nr_running += rt_se_nr_running(rt_se);
 
        inc_rt_prio(rt_rq, prio);
        inc_rt_migration(rt_se, rt_rq);
@@ -1062,7 +1137,7 @@ void dec_rt_tasks(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq)
 {
        WARN_ON(!rt_prio(rt_se_prio(rt_se)));
        WARN_ON(!rt_rq->rt_nr_running);
-       rt_rq->rt_nr_running--;
+       rt_rq->rt_nr_running -= rt_se_nr_running(rt_se);
 
        dec_rt_prio(rt_rq, rt_se_prio(rt_se));
        dec_rt_migration(rt_se, rt_rq);
@@ -1119,6 +1194,8 @@ static void dequeue_rt_stack(struct sched_rt_entity *rt_se)
                back = rt_se;
        }
 
+       dequeue_top_rt_rq(rt_rq_of_se(back));
+
        for (rt_se = back; rt_se; rt_se = rt_se->back) {
                if (on_rt_rq(rt_se))
                        __dequeue_rt_entity(rt_se);
@@ -1127,13 +1204,18 @@ static void dequeue_rt_stack(struct sched_rt_entity *rt_se)
 
 static void enqueue_rt_entity(struct sched_rt_entity *rt_se, bool head)
 {
+       struct rq *rq = rq_of_rt_se(rt_se);
+
        dequeue_rt_stack(rt_se);
        for_each_sched_rt_entity(rt_se)
                __enqueue_rt_entity(rt_se, head);
+       enqueue_top_rt_rq(&rq->rt);
 }
 
 static void dequeue_rt_entity(struct sched_rt_entity *rt_se)
 {
+       struct rq *rq = rq_of_rt_se(rt_se);
+
        dequeue_rt_stack(rt_se);
 
        for_each_sched_rt_entity(rt_se) {
@@ -1142,6 +1224,7 @@ static void dequeue_rt_entity(struct sched_rt_entity *rt_se)
                if (rt_rq && rt_rq->rt_nr_running)
                        __enqueue_rt_entity(rt_se, false);
        }
+       enqueue_top_rt_rq(&rq->rt);
 }
 
 /*
@@ -1159,8 +1242,6 @@ enqueue_task_rt(struct rq *rq, struct task_struct *p, int flags)
 
        if (!task_current(rq, p) && p->nr_cpus_allowed > 1)
                enqueue_pushable_task(rq, p);
-
-       inc_nr_running(rq);
 }
 
 static void dequeue_task_rt(struct rq *rq, struct task_struct *p, int flags)
@@ -1171,8 +1252,6 @@ static void dequeue_task_rt(struct rq *rq, struct task_struct *p, int flags)
        dequeue_rt_entity(rt_se);
 
        dequeue_pushable_task(rq, p);
-
-       dec_nr_running(rq);
 }
 
 /*
@@ -1377,10 +1456,7 @@ pick_next_task_rt(struct rq *rq, struct task_struct *prev)
        if (prev->sched_class == &rt_sched_class)
                update_curr_rt(rq);
 
-       if (!rt_rq->rt_nr_running)
-               return NULL;
-
-       if (rt_rq_throttled(rt_rq))
+       if (!rt_rq->rt_queued)
                return NULL;
 
        put_prev_task(rq, prev);
@@ -1892,9 +1968,9 @@ static void switched_to_rt(struct rq *rq, struct task_struct *p)
         */
        if (p->on_rq && rq->curr != p) {
 #ifdef CONFIG_SMP
-               if (rq->rt.overloaded && push_rt_task(rq) &&
+               if (p->nr_cpus_allowed > 1 && rq->rt.overloaded &&
                    /* Don't resched if we changed runqueues */
-                   rq != task_rq(p))
+                   push_rt_task(rq) && rq != task_rq(p))
                        check_resched = 0;
 #endif /* CONFIG_SMP */
                if (check_resched && p->prio < rq->curr->prio)