X-Git-Url: http://drtracing.org/?a=blobdiff_plain;f=kernel%2Fsched_rt.c;h=0a6d2e516420516cb1d0c35a5345db1f356f71ab;hb=05dda977f2574c3341abef9b74c27d2b362e1e3a;hp=29963af782aedb669a41a3cfce538bf0713cceea;hpb=fa717060f1ab7eb6570f2fb49136f838fc9195a9;p=deliverable%2Flinux.git

diff --git a/kernel/sched_rt.c b/kernel/sched_rt.c
index 29963af782ae..0a6d2e516420 100644
--- a/kernel/sched_rt.c
+++ b/kernel/sched_rt.c
@@ -45,6 +45,196 @@ static void update_rt_migration(struct rq *rq)
 }
 #endif /* CONFIG_SMP */
 
+static inline struct task_struct *rt_task_of(struct sched_rt_entity *rt_se)
+{
+	return container_of(rt_se, struct task_struct, rt);
+}
+
+static inline int on_rt_rq(struct sched_rt_entity *rt_se)
+{
+	return !list_empty(&rt_se->run_list);
+}
+
+#ifdef CONFIG_RT_GROUP_SCHED
+
+static inline u64 sched_rt_runtime(struct rt_rq *rt_rq)
+{
+	if (!rt_rq->tg)
+		return RUNTIME_INF;
+
+	return rt_rq->tg->rt_runtime;
+}
+
+#define for_each_leaf_rt_rq(rt_rq, rq) \
+	list_for_each_entry(rt_rq, &rq->leaf_rt_rq_list, leaf_rt_rq_list)
+
+static inline struct rq *rq_of_rt_rq(struct rt_rq *rt_rq)
+{
+	return rt_rq->rq;
+}
+
+static inline struct rt_rq *rt_rq_of_se(struct sched_rt_entity *rt_se)
+{
+	return rt_se->rt_rq;
+}
+
+#define for_each_sched_rt_entity(rt_se) \
+	for (; rt_se; rt_se = rt_se->parent)
+
+static inline struct rt_rq *group_rt_rq(struct sched_rt_entity *rt_se)
+{
+	return rt_se->my_q;
+}
+
+static void enqueue_rt_entity(struct sched_rt_entity *rt_se);
+static void dequeue_rt_entity(struct sched_rt_entity *rt_se);
+
+static void sched_rt_rq_enqueue(struct rt_rq *rt_rq)
+{
+	struct sched_rt_entity *rt_se = rt_rq->rt_se;
+
+	if (rt_se && !on_rt_rq(rt_se) && rt_rq->rt_nr_running) {
+		struct task_struct *curr = rq_of_rt_rq(rt_rq)->curr;
+
+		enqueue_rt_entity(rt_se);
+		if (rt_rq->highest_prio < curr->prio)
+			resched_task(curr);
+	}
+}
+
+static void sched_rt_rq_dequeue(struct rt_rq *rt_rq)
+{
+	struct sched_rt_entity *rt_se = rt_rq->rt_se;
+
+	if (rt_se && 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);
+	struct task_struct *p;
+
+	if (rt_rq)
+		return !!rt_rq->rt_nr_boosted;
+
+	p = rt_task_of(rt_se);
+	return p->prio != p->normal_prio;
+}
+
+#else
+
+static inline u64 sched_rt_runtime(struct rt_rq *rt_rq)
+{
+	if (sysctl_sched_rt_runtime == -1)
+		return RUNTIME_INF;
+
+	return (u64)sysctl_sched_rt_runtime * NSEC_PER_USEC;
+}
+
+#define for_each_leaf_rt_rq(rt_rq, rq) \
+	for (rt_rq = &rq->rt; rt_rq; rt_rq = NULL)
+
+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)
+{
+	struct task_struct *p = rt_task_of(rt_se);
+	struct rq *rq = task_rq(p);
+
+	return &rq->rt;
+}
+
+#define for_each_sched_rt_entity(rt_se) \
+	for (; rt_se; rt_se = NULL)
+
+static inline struct rt_rq *group_rt_rq(struct sched_rt_entity *rt_se)
+{
+	return NULL;
+}
+
+static inline void sched_rt_rq_enqueue(struct rt_rq *rt_rq)
+{
+}
+
+static inline void sched_rt_rq_dequeue(struct rt_rq *rt_rq)
+{
+}
+
+static inline int rt_rq_throttled(struct rt_rq *rt_rq)
+{
+	return rt_rq->rt_throttled;
+}
+#endif
+
+static inline int rt_se_prio(struct sched_rt_entity *rt_se)
+{
+#ifdef CONFIG_RT_GROUP_SCHED
+	struct rt_rq *rt_rq = group_rt_rq(rt_se);
+
+	if (rt_rq)
+		return rt_rq->highest_prio;
+#endif
+
+	return rt_task_of(rt_se)->prio;
+}
+
+static int sched_rt_runtime_exceeded(struct rt_rq *rt_rq)
+{
+	u64 runtime = sched_rt_runtime(rt_rq);
+
+	if (runtime == RUNTIME_INF)
+		return 0;
+
+	if (rt_rq->rt_throttled)
+		return rt_rq_throttled(rt_rq);
+
+	if (rt_rq->rt_time > runtime) {
+		struct rq *rq = rq_of_rt_rq(rt_rq);
+
+		rq->rt_throttled = 1;
+		rt_rq->rt_throttled = 1;
+
+		if (rt_rq_throttled(rt_rq)) {
+			sched_rt_rq_dequeue(rt_rq);
+			return 1;
+		}
+	}
+
+	return 0;
+}
+
+static void update_sched_rt_period(struct rq *rq)
+{
+	struct rt_rq *rt_rq;
+	u64 period;
+
+	while (rq->clock > rq->rt_period_expire) {
+		period = (u64)sysctl_sched_rt_period * NSEC_PER_USEC;
+		rq->rt_period_expire += period;
+
+		for_each_leaf_rt_rq(rt_rq, rq) {
+			u64 runtime = sched_rt_runtime(rt_rq);
+
+			rt_rq->rt_time -= min(rt_rq->rt_time, runtime);
+			if (rt_rq->rt_throttled && rt_rq->rt_time < runtime) {
+				rt_rq->rt_throttled = 0;
+				sched_rt_rq_enqueue(rt_rq);
+			}
+		}
+
+		rq->rt_throttled = 0;
+	}
+}
+
 /*
  * Update the current task's runtime statistics. Skip current tasks that
  * are not in our scheduling class.
@@ -52,6 +242,8 @@ static void update_rt_migration(struct rq *rq)
 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 (!task_has_rt_policy(curr))
@@ -66,88 +258,186 @@ static void update_curr_rt(struct rq *rq)
 	curr->se.sum_exec_runtime += delta_exec;
 	curr->se.exec_start = rq->clock;
 	cpuacct_charge(curr, delta_exec);
+
+	rt_rq->rt_time += delta_exec;
+	if (sched_rt_runtime_exceeded(rt_rq))
+		resched_task(curr);
 }
 
-static inline void inc_rt_tasks(struct task_struct *p, struct rq *rq)
+static inline
+void inc_rt_tasks(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq)
 {
-	WARN_ON(!rt_task(p));
-	rq->rt.rt_nr_running++;
+	WARN_ON(!rt_prio(rt_se_prio(rt_se)));
+	rt_rq->rt_nr_running++;
+#if defined CONFIG_SMP || defined CONFIG_RT_GROUP_SCHED
+	if (rt_se_prio(rt_se) < rt_rq->highest_prio)
+		rt_rq->highest_prio = rt_se_prio(rt_se);
+#endif
 #ifdef CONFIG_SMP
-	if (p->prio < rq->rt.highest_prio)
-		rq->rt.highest_prio = p->prio;
-	if (p->nr_cpus_allowed > 1)
+	if (rt_se->nr_cpus_allowed > 1) {
+		struct rq *rq = rq_of_rt_rq(rt_rq);
 		rq->rt.rt_nr_migratory++;
+	}
 
-	update_rt_migration(rq);
-#endif /* CONFIG_SMP */
+	update_rt_migration(rq_of_rt_rq(rt_rq));
+#endif
+#ifdef CONFIG_RT_GROUP_SCHED
+	if (rt_se_boosted(rt_se))
+		rt_rq->rt_nr_boosted++;
+#endif
 }
 
-static inline void dec_rt_tasks(struct task_struct *p, struct rq *rq)
+static inline
+void dec_rt_tasks(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq)
 {
-	WARN_ON(!rt_task(p));
-	WARN_ON(!rq->rt.rt_nr_running);
-	rq->rt.rt_nr_running--;
-#ifdef CONFIG_SMP
-	if (rq->rt.rt_nr_running) {
+	WARN_ON(!rt_prio(rt_se_prio(rt_se)));
+	WARN_ON(!rt_rq->rt_nr_running);
+	rt_rq->rt_nr_running--;
+#if defined CONFIG_SMP || defined CONFIG_RT_GROUP_SCHED
+	if (rt_rq->rt_nr_running) {
 		struct rt_prio_array *array;
 
-		WARN_ON(p->prio < rq->rt.highest_prio);
-		if (p->prio == rq->rt.highest_prio) {
+		WARN_ON(rt_se_prio(rt_se) < rt_rq->highest_prio);
+		if (rt_se_prio(rt_se) == rt_rq->highest_prio) {
 			/* recalculate */
-			array = &rq->rt.active;
-			rq->rt.highest_prio =
+			array = &rt_rq->active;
+			rt_rq->highest_prio =
 				sched_find_first_bit(array->bitmap);
 		} /* otherwise leave rq->highest prio alone */
 	} else
-		rq->rt.highest_prio = MAX_RT_PRIO;
-	if (p->nr_cpus_allowed > 1)
+		rt_rq->highest_prio = MAX_RT_PRIO;
+#endif
+#ifdef CONFIG_SMP
+	if (rt_se->nr_cpus_allowed > 1) {
+		struct rq *rq = rq_of_rt_rq(rt_rq);
 		rq->rt.rt_nr_migratory--;
+	}
 
-	update_rt_migration(rq);
+	update_rt_migration(rq_of_rt_rq(rt_rq));
 #endif /* CONFIG_SMP */
+#ifdef CONFIG_RT_GROUP_SCHED
+	if (rt_se_boosted(rt_se))
+		rt_rq->rt_nr_boosted--;
+
+	WARN_ON(!rt_rq->rt_nr_running && rt_rq->rt_nr_boosted);
+#endif
 }
 
-static void enqueue_task_rt(struct rq *rq, struct task_struct *p, int wakeup)
+static void enqueue_rt_entity(struct sched_rt_entity *rt_se)
 {
-	struct rt_prio_array *array = &rq->rt.active;
+	struct rt_rq *rt_rq = rt_rq_of_se(rt_se);
+	struct rt_prio_array *array = &rt_rq->active;
+	struct rt_rq *group_rq = group_rt_rq(rt_se);
 
-	list_add_tail(&p->rt.run_list, array->queue + p->prio);
-	__set_bit(p->prio, array->bitmap);
-	inc_cpu_load(rq, p->se.load.weight);
+	if (group_rq && rt_rq_throttled(group_rq))
+		return;
+
+	list_add_tail(&rt_se->run_list, array->queue + rt_se_prio(rt_se));
+	__set_bit(rt_se_prio(rt_se), array->bitmap);
+
+	inc_rt_tasks(rt_se, rt_rq);
+}
+
+static void dequeue_rt_entity(struct sched_rt_entity *rt_se)
+{
+	struct rt_rq *rt_rq = rt_rq_of_se(rt_se);
+	struct rt_prio_array *array = &rt_rq->active;
+
+	list_del_init(&rt_se->run_list);
+	if (list_empty(array->queue + rt_se_prio(rt_se)))
+		__clear_bit(rt_se_prio(rt_se), array->bitmap);
+
+	dec_rt_tasks(rt_se, rt_rq);
+}
+
+/*
+ * Because the prio of an upper entry depends on the lower
+ * entries, we must remove entries top - down.
+ *
+ * XXX: O(1/2 h^2) because we can only walk up, not down the chain.
+ *      doesn't matter much for now, as h=2 for GROUP_SCHED.
+ */
+static void dequeue_rt_stack(struct task_struct *p)
+{
+	struct sched_rt_entity *rt_se, *top_se;
 
-	inc_rt_tasks(p, rq);
+	/*
+	 * dequeue all, top - down.
+	 */
+	do {
+		rt_se = &p->rt;
+		top_se = NULL;
+		for_each_sched_rt_entity(rt_se) {
+			if (on_rt_rq(rt_se))
+				top_se = rt_se;
+		}
+		if (top_se)
+			dequeue_rt_entity(top_se);
+	} while (top_se);
 }
 
 /*
  * Adding/removing a task to/from a priority array:
  */
+static void enqueue_task_rt(struct rq *rq, struct task_struct *p, int wakeup)
+{
+	struct sched_rt_entity *rt_se = &p->rt;
+
+	if (wakeup)
+		rt_se->timeout = 0;
+
+	dequeue_rt_stack(p);
+
+	/*
+	 * enqueue everybody, bottom - up.
+	 */
+	for_each_sched_rt_entity(rt_se)
+		enqueue_rt_entity(rt_se);
+}
+
 static void dequeue_task_rt(struct rq *rq, struct task_struct *p, int sleep)
 {
-	struct rt_prio_array *array = &rq->rt.active;
+	struct sched_rt_entity *rt_se = &p->rt;
+	struct rt_rq *rt_rq;
 
 	update_curr_rt(rq);
 
-	list_del(&p->rt.run_list);
-	if (list_empty(array->queue + p->prio))
-		__clear_bit(p->prio, array->bitmap);
-	dec_cpu_load(rq, p->se.load.weight);
+	dequeue_rt_stack(p);
 
-	dec_rt_tasks(p, rq);
+	/*
+	 * re-enqueue all non-empty rt_rq entities.
+	 */
+	for_each_sched_rt_entity(rt_se) {
+		rt_rq = group_rt_rq(rt_se);
+		if (rt_rq && rt_rq->rt_nr_running)
+			enqueue_rt_entity(rt_se);
+	}
 }
 
 /*
  * Put task to the end of the run list without the overhead of dequeue
  * followed by enqueue.
  */
+static
+void requeue_rt_entity(struct rt_rq *rt_rq, struct sched_rt_entity *rt_se)
+{
+	struct rt_prio_array *array = &rt_rq->active;
+
+	list_move_tail(&rt_se->run_list, array->queue + rt_se_prio(rt_se));
+}
+
 static void requeue_task_rt(struct rq *rq, struct task_struct *p)
 {
-	struct rt_prio_array *array = &rq->rt.active;
+	struct sched_rt_entity *rt_se = &p->rt;
+	struct rt_rq *rt_rq;
 
-	list_move_tail(&p->rt.run_list, array->queue + p->prio);
+	for_each_sched_rt_entity(rt_se) {
+		rt_rq = rt_rq_of_se(rt_se);
+		requeue_rt_entity(rt_rq, rt_se);
+	}
 }
 
-static void
-yield_task_rt(struct rq *rq)
+static void yield_task_rt(struct rq *rq)
 {
 	requeue_task_rt(rq, rq->curr);
 }
@@ -177,7 +467,7 @@ static int select_task_rq_rt(struct task_struct *p, int sync)
 	 * cold cache anyway.
 	 */
 	if (unlikely(rt_task(rq->curr)) &&
-	    (p->nr_cpus_allowed > 1)) {
+	    (p->rt.nr_cpus_allowed > 1)) {
 		int cpu = find_lowest_rq(p);
 
 		return (cpu == -1) ? task_cpu(p) : cpu;
@@ -200,25 +490,48 @@ static void check_preempt_curr_rt(struct rq *rq, struct task_struct *p)
 		resched_task(rq->curr);
 }
 
-static struct task_struct *pick_next_task_rt(struct rq *rq)
+static struct sched_rt_entity *pick_next_rt_entity(struct rq *rq,
+						   struct rt_rq *rt_rq)
 {
-	struct rt_prio_array *array = &rq->rt.active;
-	struct task_struct *next;
+	struct rt_prio_array *array = &rt_rq->active;
+	struct sched_rt_entity *next = NULL;
 	struct list_head *queue;
 	int idx;
 
 	idx = sched_find_first_bit(array->bitmap);
-	if (idx >= MAX_RT_PRIO)
-		return NULL;
+	BUG_ON(idx >= MAX_RT_PRIO);
 
 	queue = array->queue + idx;
-	next = list_entry(queue->next, struct task_struct, rt.run_list);
-
-	next->se.exec_start = rq->clock;
+	next = list_entry(queue->next, struct sched_rt_entity, run_list);
 
 	return next;
 }
 
+static struct task_struct *pick_next_task_rt(struct rq *rq)
+{
+	struct sched_rt_entity *rt_se;
+	struct task_struct *p;
+	struct rt_rq *rt_rq;
+
+	rt_rq = &rq->rt;
+
+	if (unlikely(!rt_rq->rt_nr_running))
+		return NULL;
+
+	if (rt_rq_throttled(rt_rq))
+		return NULL;
+
+	do {
+		rt_se = pick_next_rt_entity(rq, rt_rq);
+		BUG_ON(!rt_se);
+		rt_rq = group_rt_rq(rt_se);
+	} while (rt_rq);
+
+	p = rt_task_of(rt_se);
+	p->se.exec_start = rq->clock;
+	return p;
+}
+
 static void put_prev_task_rt(struct rq *rq, struct task_struct *p)
 {
 	update_curr_rt(rq);
@@ -226,6 +539,7 @@ static void put_prev_task_rt(struct rq *rq, struct task_struct *p)
 }
 
 #ifdef CONFIG_SMP
+
 /* Only try algorithms three times */
 #define RT_MAX_TRIES 3
 
@@ -236,7 +550,7 @@ static int pick_rt_task(struct rq *rq, struct task_struct *p, int cpu)
 {
 	if (!task_running(rq, p) &&
 	    (cpu < 0 || cpu_isset(cpu, p->cpus_allowed)) &&
-	    (p->nr_cpus_allowed > 1))
+	    (p->rt.nr_cpus_allowed > 1))
 		return 1;
 	return 0;
 }
@@ -244,52 +558,33 @@ static int pick_rt_task(struct rq *rq, struct task_struct *p, int cpu)
 /* Return the second highest RT task, NULL otherwise */
 static struct task_struct *pick_next_highest_task_rt(struct rq *rq, int cpu)
 {
-	struct rt_prio_array *array = &rq->rt.active;
-	struct task_struct *next;
-	struct list_head *queue;
+	struct task_struct *next = NULL;
+	struct sched_rt_entity *rt_se;
+	struct rt_prio_array *array;
+	struct rt_rq *rt_rq;
 	int idx;
 
-	if (likely(rq->rt.rt_nr_running < 2))
-		return NULL;
-
-	idx = sched_find_first_bit(array->bitmap);
-	if (unlikely(idx >= MAX_RT_PRIO)) {
-		WARN_ON(1); /* rt_nr_running is bad */
-		return NULL;
-	}
-
-	queue = array->queue + idx;
-	BUG_ON(list_empty(queue));
-
-	next = list_entry(queue->next, struct task_struct, rt.run_list);
-	if (unlikely(pick_rt_task(rq, next, cpu)))
-		goto out;
-
-	if (queue->next->next != queue) {
-		/* same prio task */
-		next = list_entry(queue->next->next, struct task_struct,
-				  rt.run_list);
-		if (pick_rt_task(rq, next, cpu))
-			goto out;
-	}
-
- retry:
-	/* slower, but more flexible */
-	idx = find_next_bit(array->bitmap, MAX_RT_PRIO, idx+1);
-	if (unlikely(idx >= MAX_RT_PRIO))
-		return NULL;
-
-	queue = array->queue + idx;
-	BUG_ON(list_empty(queue));
-
-	list_for_each_entry(next, queue, rt.run_list) {
-		if (pick_rt_task(rq, next, cpu))
-			goto out;
+	for_each_leaf_rt_rq(rt_rq, rq) {
+		array = &rt_rq->active;
+		idx = sched_find_first_bit(array->bitmap);
+ next_idx:
+		if (idx >= MAX_RT_PRIO)
+			continue;
+		if (next && next->prio < idx)
+			continue;
+		list_for_each_entry(rt_se, array->queue + idx, run_list) {
+			struct task_struct *p = rt_task_of(rt_se);
+			if (pick_rt_task(rq, p, cpu)) {
+				next = p;
+				break;
+			}
+		}
+		if (!next) {
+			idx = find_next_bit(array->bitmap, MAX_RT_PRIO, idx+1);
+			goto next_idx;
+		}
 	}
 
-	goto retry;
-
- out:
 	return next;
 }
 
@@ -604,10 +899,8 @@ static int pull_rt_task(struct rq *this_rq)
 		/*
 		 * Are there still pullable RT tasks?
 		 */
-		if (src_rq->rt.rt_nr_running <= 1) {
-			spin_unlock(&src_rq->lock);
-			continue;
-		}
+		if (src_rq->rt.rt_nr_running <= 1)
+			goto skip;
 
 		p = pick_next_highest_task_rt(src_rq, this_cpu);
 
@@ -631,7 +924,7 @@ static int pull_rt_task(struct rq *this_rq)
 			 */
 			if (p->prio < src_rq->curr->prio ||
 			    (next && next->prio < src_rq->curr->prio))
-				goto out;
+				goto skip;
 
 			ret = 1;
 
@@ -651,7 +944,7 @@ static int pull_rt_task(struct rq *this_rq)
 			next = p;
 
 		}
- out:
+ skip:
 		spin_unlock(&src_rq->lock);
 	}
 
@@ -718,12 +1011,12 @@ static void set_cpus_allowed_rt(struct task_struct *p, cpumask_t *new_mask)
 	 * Update the migration status of the RQ if we have an RT task
 	 * which is running AND changing its weight value.
 	 */
-	if (p->se.on_rq && (weight != p->nr_cpus_allowed)) {
+	if (p->se.on_rq && (weight != p->rt.nr_cpus_allowed)) {
 		struct rq *rq = task_rq(p);
 
-		if ((p->nr_cpus_allowed <= 1) && (weight > 1)) {
+		if ((p->rt.nr_cpus_allowed <= 1) && (weight > 1)) {
 			rq->rt.rt_nr_migratory++;
-		} else if ((p->nr_cpus_allowed > 1) && (weight <= 1)) {
+		} else if ((p->rt.nr_cpus_allowed > 1) && (weight <= 1)) {
 			BUG_ON(!rq->rt.rt_nr_migratory);
 			rq->rt.rt_nr_migratory--;
 		}
@@ -732,7 +1025,7 @@ static void set_cpus_allowed_rt(struct task_struct *p, cpumask_t *new_mask)
 	}
 
 	p->cpus_allowed    = *new_mask;
-	p->nr_cpus_allowed = weight;
+	p->rt.nr_cpus_allowed = weight;
 }
 
 /* Assumes rq->lock is held */
@@ -814,9 +1107,11 @@ static void prio_changed_rt(struct rq *rq, struct task_struct *p,
 			pull_rt_task(rq);
 		/*
 		 * If there's a higher priority task waiting to run
-		 * then reschedule.
+		 * then reschedule. Note, the above pull_rt_task
+		 * can release the rq lock and p could migrate.
+		 * Only reschedule if p is still on the same runqueue.
 		 */
-		if (p->prio > rq->rt.highest_prio)
+		if (p->prio > rq->rt.highest_prio && rq->curr == p)
 			resched_task(p);
 #else
 		/* For UP simply resched on drop of prio */
@@ -834,11 +1129,32 @@ static void prio_changed_rt(struct rq *rq, struct task_struct *p,
 	}
 }
 
+static void watchdog(struct rq *rq, struct task_struct *p)
+{
+	unsigned long soft, hard;
+
+	if (!p->signal)
+		return;
+
+	soft = p->signal->rlim[RLIMIT_RTTIME].rlim_cur;
+	hard = p->signal->rlim[RLIMIT_RTTIME].rlim_max;
+
+	if (soft != RLIM_INFINITY) {
+		unsigned long next;
+
+		p->rt.timeout++;
+		next = DIV_ROUND_UP(min(soft, hard), USEC_PER_SEC/HZ);
+		if (p->rt.timeout > next)
+			p->it_sched_expires = p->se.sum_exec_runtime;
+	}
+}
 
-static void task_tick_rt(struct rq *rq, struct task_struct *p)
+static void task_tick_rt(struct rq *rq, struct task_struct *p, int queued)
 {
 	update_curr_rt(rq);
 
+	watchdog(rq, p);
+
 	/*
 	 * RR tasks need a special form of timeslice management.
 	 * FIFO tasks have no timeslices.