* policies)
*/
+#ifdef CONFIG_RT_GROUP_SCHED
+
+#define rt_entity_is_task(rt_se) (!(rt_se)->my_q)
+
+static inline struct task_struct *rt_task_of(struct sched_rt_entity *rt_se)
+{
+#ifdef CONFIG_SCHED_DEBUG
+ WARN_ON_ONCE(!rt_entity_is_task(rt_se));
+#endif
+ return container_of(rt_se, struct task_struct, rt);
+}
+
+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;
+}
+
+#else /* CONFIG_RT_GROUP_SCHED */
+
+#define rt_entity_is_task(rt_se) (1)
+
+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 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;
+}
+
+#endif /* CONFIG_RT_GROUP_SCHED */
+
+#ifdef CONFIG_SMP
+
+static inline int rt_overloaded(struct rq *rq)
+{
+ return atomic_read(&rq->rd->rto_count);
+}
+
+static inline void rt_set_overload(struct rq *rq)
+{
+ if (!rq->online)
+ return;
+
+ cpumask_set_cpu(rq->cpu, rq->rd->rto_mask);
+ /*
+ * Make sure the mask is visible before we set
+ * the overload count. That is checked to determine
+ * if we should look at the mask. It would be a shame
+ * if we looked at the mask, but the mask was not
+ * updated yet.
+ */
+ wmb();
+ atomic_inc(&rq->rd->rto_count);
+}
+
+static inline void rt_clear_overload(struct rq *rq)
+{
+ if (!rq->online)
+ return;
+
+ /* the order here really doesn't matter */
+ atomic_dec(&rq->rd->rto_count);
+ cpumask_clear_cpu(rq->cpu, rq->rd->rto_mask);
+}
+
+static void update_rt_migration(struct rt_rq *rt_rq)
+{
+ if (rt_rq->rt_nr_migratory && rt_rq->rt_nr_total > 1) {
+ if (!rt_rq->overloaded) {
+ rt_set_overload(rq_of_rt_rq(rt_rq));
+ rt_rq->overloaded = 1;
+ }
+ } else if (rt_rq->overloaded) {
+ rt_clear_overload(rq_of_rt_rq(rt_rq));
+ rt_rq->overloaded = 0;
+ }
+}
+
+static void inc_rt_migration(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq)
+{
+ if (!rt_entity_is_task(rt_se))
+ return;
+
+ rt_rq = &rq_of_rt_rq(rt_rq)->rt;
+
+ rt_rq->rt_nr_total++;
+ if (rt_se->nr_cpus_allowed > 1)
+ rt_rq->rt_nr_migratory++;
+
+ update_rt_migration(rt_rq);
+}
+
+static void dec_rt_migration(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq)
+{
+ if (!rt_entity_is_task(rt_se))
+ return;
+
+ rt_rq = &rq_of_rt_rq(rt_rq)->rt;
+
+ rt_rq->rt_nr_total--;
+ if (rt_se->nr_cpus_allowed > 1)
+ rt_rq->rt_nr_migratory--;
+
+ update_rt_migration(rt_rq);
+}
+
+static void enqueue_pushable_task(struct rq *rq, struct task_struct *p)
+{
+ plist_del(&p->pushable_tasks, &rq->rt.pushable_tasks);
+ plist_node_init(&p->pushable_tasks, p->prio);
+ plist_add(&p->pushable_tasks, &rq->rt.pushable_tasks);
+}
+
+static void dequeue_pushable_task(struct rq *rq, struct task_struct *p)
+{
+ plist_del(&p->pushable_tasks, &rq->rt.pushable_tasks);
+}
+
+static inline int has_pushable_tasks(struct rq *rq)
+{
+ return !plist_head_empty(&rq->rt.pushable_tasks);
+}
+
+#else
+
+static inline void enqueue_pushable_task(struct rq *rq, struct task_struct *p)
+{
+}
+
+static inline void dequeue_pushable_task(struct rq *rq, struct task_struct *p)
+{
+}
+
+static inline
+void inc_rt_migration(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq)
+{
+}
+
+static inline
+void dec_rt_migration(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq)
+{
+}
+
+#endif /* CONFIG_SMP */
+
+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->rt_runtime;
+}
+
+static inline u64 sched_rt_period(struct rt_rq *rt_rq)
+{
+ return ktime_to_ns(rt_rq->tg->rt_bandwidth.rt_period);
+}
+
+#define for_each_leaf_rt_rq(rt_rq, rq) \
+ list_for_each_entry_rcu(rt_rq, &rq->leaf_rt_rq_list, leaf_rt_rq_list)
+
+#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, bool head);
+static void dequeue_rt_entity(struct sched_rt_entity *rt_se);
+
+static void sched_rt_rq_enqueue(struct rt_rq *rt_rq)
+{
+ int this_cpu = smp_processor_id();
+ struct task_struct *curr = rq_of_rt_rq(rt_rq)->curr;
+ struct sched_rt_entity *rt_se;
+
+ rt_se = rt_rq->tg->rt_se[this_cpu];
+
+ if (rt_rq->rt_nr_running) {
+ if (rt_se && !on_rt_rq(rt_se))
+ enqueue_rt_entity(rt_se, false);
+ if (rt_rq->highest_prio.curr < curr->prio)
+ resched_task(curr);
+ }
+}
+
+static void sched_rt_rq_dequeue(struct rt_rq *rt_rq)
+{
+ int this_cpu = smp_processor_id();
+ struct sched_rt_entity *rt_se;
+
+ rt_se = rt_rq->tg->rt_se[this_cpu];
+
+ 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;
+}
+
+#ifdef CONFIG_SMP
+static inline const struct cpumask *sched_rt_period_mask(void)
+{
+ return cpu_rq(smp_processor_id())->rd->span;
+}
+#else
+static inline const struct cpumask *sched_rt_period_mask(void)
+{
+ return cpu_online_mask;
+}
+#endif
+
+static inline
+struct rt_rq *sched_rt_period_rt_rq(struct rt_bandwidth *rt_b, int cpu)
+{
+ return container_of(rt_b, struct task_group, rt_bandwidth)->rt_rq[cpu];
+}
+
+static inline struct rt_bandwidth *sched_rt_bandwidth(struct rt_rq *rt_rq)
+{
+ return &rt_rq->tg->rt_bandwidth;
+}
+
+#else /* !CONFIG_RT_GROUP_SCHED */
+
+static inline u64 sched_rt_runtime(struct rt_rq *rt_rq)
+{
+ return rt_rq->rt_runtime;
+}
+
+static inline u64 sched_rt_period(struct rt_rq *rt_rq)
+{
+ return ktime_to_ns(def_rt_bandwidth.rt_period);
+}
+
+#define for_each_leaf_rt_rq(rt_rq, rq) \
+ for (rt_rq = &rq->rt; rt_rq; rt_rq = NULL)
+
+#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)
+{
+ if (rt_rq->rt_nr_running)
+ resched_task(rq_of_rt_rq(rt_rq)->curr);
+}
+
+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;
+}
+
+static inline const struct cpumask *sched_rt_period_mask(void)
+{
+ return cpu_online_mask;
+}
+
+static inline
+struct rt_rq *sched_rt_period_rt_rq(struct rt_bandwidth *rt_b, int cpu)
+{
+ return &cpu_rq(cpu)->rt;
+}
+
+static inline struct rt_bandwidth *sched_rt_bandwidth(struct rt_rq *rt_rq)
+{
+ return &def_rt_bandwidth;
+}
+
+#endif /* CONFIG_RT_GROUP_SCHED */
+
+#ifdef CONFIG_SMP
+/*
+ * We ran out of runtime, see if we can borrow some from our neighbours.
+ */
+static int do_balance_runtime(struct rt_rq *rt_rq)
+{
+ struct rt_bandwidth *rt_b = sched_rt_bandwidth(rt_rq);
+ struct root_domain *rd = cpu_rq(smp_processor_id())->rd;
+ int i, weight, more = 0;
+ u64 rt_period;
+
+ weight = cpumask_weight(rd->span);
+
+ raw_spin_lock(&rt_b->rt_runtime_lock);
+ rt_period = ktime_to_ns(rt_b->rt_period);
+ for_each_cpu(i, rd->span) {
+ struct rt_rq *iter = sched_rt_period_rt_rq(rt_b, i);
+ s64 diff;
+
+ if (iter == rt_rq)
+ continue;
+
+ raw_spin_lock(&iter->rt_runtime_lock);
+ /*
+ * Either all rqs have inf runtime and there's nothing to steal
+ * or __disable_runtime() below sets a specific rq to inf to
+ * indicate its been disabled and disalow stealing.
+ */
+ if (iter->rt_runtime == RUNTIME_INF)
+ goto next;
+
+ /*
+ * From runqueues with spare time, take 1/n part of their
+ * spare time, but no more than our period.
+ */
+ diff = iter->rt_runtime - iter->rt_time;
+ if (diff > 0) {
+ diff = div_u64((u64)diff, weight);
+ if (rt_rq->rt_runtime + diff > rt_period)
+ diff = rt_period - rt_rq->rt_runtime;
+ iter->rt_runtime -= diff;
+ rt_rq->rt_runtime += diff;
+ more = 1;
+ if (rt_rq->rt_runtime == rt_period) {
+ raw_spin_unlock(&iter->rt_runtime_lock);
+ break;
+ }
+ }
+next:
+ raw_spin_unlock(&iter->rt_runtime_lock);
+ }
+ raw_spin_unlock(&rt_b->rt_runtime_lock);
+
+ return more;
+}
+
+/*
+ * Ensure this RQ takes back all the runtime it lend to its neighbours.
+ */
+static void __disable_runtime(struct rq *rq)
+{
+ struct root_domain *rd = rq->rd;
+ struct rt_rq *rt_rq;
+
+ if (unlikely(!scheduler_running))
+ return;
+
+ for_each_leaf_rt_rq(rt_rq, rq) {
+ struct rt_bandwidth *rt_b = sched_rt_bandwidth(rt_rq);
+ s64 want;
+ int i;
+
+ raw_spin_lock(&rt_b->rt_runtime_lock);
+ raw_spin_lock(&rt_rq->rt_runtime_lock);
+ /*
+ * Either we're all inf and nobody needs to borrow, or we're
+ * already disabled and thus have nothing to do, or we have
+ * exactly the right amount of runtime to take out.
+ */
+ if (rt_rq->rt_runtime == RUNTIME_INF ||
+ rt_rq->rt_runtime == rt_b->rt_runtime)
+ goto balanced;
+ raw_spin_unlock(&rt_rq->rt_runtime_lock);
+
+ /*
+ * Calculate the difference between what we started out with
+ * and what we current have, that's the amount of runtime
+ * we lend and now have to reclaim.
+ */
+ want = rt_b->rt_runtime - rt_rq->rt_runtime;
+
+ /*
+ * Greedy reclaim, take back as much as we can.
+ */
+ for_each_cpu(i, rd->span) {
+ struct rt_rq *iter = sched_rt_period_rt_rq(rt_b, i);
+ s64 diff;
+
+ /*
+ * Can't reclaim from ourselves or disabled runqueues.
+ */
+ if (iter == rt_rq || iter->rt_runtime == RUNTIME_INF)
+ continue;
+
+ raw_spin_lock(&iter->rt_runtime_lock);
+ if (want > 0) {
+ diff = min_t(s64, iter->rt_runtime, want);
+ iter->rt_runtime -= diff;
+ want -= diff;
+ } else {
+ iter->rt_runtime -= want;
+ want -= want;
+ }
+ raw_spin_unlock(&iter->rt_runtime_lock);
+
+ if (!want)
+ break;
+ }
+
+ raw_spin_lock(&rt_rq->rt_runtime_lock);
+ /*
+ * We cannot be left wanting - that would mean some runtime
+ * leaked out of the system.
+ */
+ BUG_ON(want);
+balanced:
+ /*
+ * Disable all the borrow logic by pretending we have inf
+ * runtime - in which case borrowing doesn't make sense.
+ */
+ rt_rq->rt_runtime = RUNTIME_INF;
+ raw_spin_unlock(&rt_rq->rt_runtime_lock);
+ raw_spin_unlock(&rt_b->rt_runtime_lock);
+ }
+}
+
+static void disable_runtime(struct rq *rq)
+{
+ unsigned long flags;
+
+ raw_spin_lock_irqsave(&rq->lock, flags);
+ __disable_runtime(rq);
+ raw_spin_unlock_irqrestore(&rq->lock, flags);
+}
+
+static void __enable_runtime(struct rq *rq)
+{
+ struct rt_rq *rt_rq;
+
+ if (unlikely(!scheduler_running))
+ return;
+
+ /*
+ * Reset each runqueue's bandwidth settings
+ */
+ for_each_leaf_rt_rq(rt_rq, rq) {
+ struct rt_bandwidth *rt_b = sched_rt_bandwidth(rt_rq);
+
+ raw_spin_lock(&rt_b->rt_runtime_lock);
+ raw_spin_lock(&rt_rq->rt_runtime_lock);
+ rt_rq->rt_runtime = rt_b->rt_runtime;
+ rt_rq->rt_time = 0;
+ rt_rq->rt_throttled = 0;
+ raw_spin_unlock(&rt_rq->rt_runtime_lock);
+ raw_spin_unlock(&rt_b->rt_runtime_lock);
+ }
+}
+
+static void enable_runtime(struct rq *rq)
+{
+ unsigned long flags;
+
+ raw_spin_lock_irqsave(&rq->lock, flags);
+ __enable_runtime(rq);
+ raw_spin_unlock_irqrestore(&rq->lock, flags);
+}
+
+static int balance_runtime(struct rt_rq *rt_rq)
+{
+ int more = 0;
+
+ if (rt_rq->rt_time > rt_rq->rt_runtime) {
+ raw_spin_unlock(&rt_rq->rt_runtime_lock);
+ more = do_balance_runtime(rt_rq);
+ raw_spin_lock(&rt_rq->rt_runtime_lock);
+ }
+
+ return more;
+}
+#else /* !CONFIG_SMP */
+static inline int balance_runtime(struct rt_rq *rt_rq)
+{
+ return 0;
+}
+#endif /* CONFIG_SMP */
+
+static int do_sched_rt_period_timer(struct rt_bandwidth *rt_b, int overrun)
+{
+ int i, idle = 1;
+ const struct cpumask *span;
+
+ if (!rt_bandwidth_enabled() || rt_b->rt_runtime == RUNTIME_INF)
+ return 1;
+
+ span = sched_rt_period_mask();
+ for_each_cpu(i, span) {
+ int enqueue = 0;
+ struct rt_rq *rt_rq = sched_rt_period_rt_rq(rt_b, i);
+ struct rq *rq = rq_of_rt_rq(rt_rq);
+
+ raw_spin_lock(&rq->lock);
+ if (rt_rq->rt_time) {
+ u64 runtime;
+
+ raw_spin_lock(&rt_rq->rt_runtime_lock);
+ if (rt_rq->rt_throttled)
+ balance_runtime(rt_rq);
+ runtime = rt_rq->rt_runtime;
+ rt_rq->rt_time -= min(rt_rq->rt_time, overrun*runtime);
+ if (rt_rq->rt_throttled && rt_rq->rt_time < runtime) {
+ rt_rq->rt_throttled = 0;
+ enqueue = 1;
+ }
+ if (rt_rq->rt_time || rt_rq->rt_nr_running)
+ idle = 0;
+ raw_spin_unlock(&rt_rq->rt_runtime_lock);
+ } else if (rt_rq->rt_nr_running)
+ idle = 0;
+
+ if (enqueue)
+ sched_rt_rq_enqueue(rt_rq);
+ raw_spin_unlock(&rq->lock);
+ }
+
+ return idle;
+}
+
+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.curr;
+#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 (rt_rq->rt_throttled)
+ return rt_rq_throttled(rt_rq);
+
+ if (sched_rt_runtime(rt_rq) >= sched_rt_period(rt_rq))
+ return 0;
+
+ balance_runtime(rt_rq);
+ runtime = sched_rt_runtime(rt_rq);
+ if (runtime == RUNTIME_INF)
+ return 0;
+
+ if (rt_rq->rt_time > runtime) {
+ rt_rq->rt_throttled = 1;
+ if (rt_rq_throttled(rt_rq)) {
+ sched_rt_rq_dequeue(rt_rq);
+ return 1;
+ }
+ }
+
+ return 0;
+}
+
/*
* Update the current task's runtime statistics. Skip current tasks that
* are not in our scheduling class.
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))
schedstat_set(curr->se.exec_max, max(curr->se.exec_max, delta_exec));
curr->se.sum_exec_runtime += delta_exec;
+ account_group_exec_runtime(curr, delta_exec);
+
curr->se.exec_start = rq->clock;
cpuacct_charge(curr, delta_exec);
+
+ sched_rt_avg_update(rq, delta_exec);
+
+ if (!rt_bandwidth_enabled())
+ return;
+
+ for_each_sched_rt_entity(rt_se) {
+ rt_rq = rt_rq_of_se(rt_se);
+
+ if (sched_rt_runtime(rt_rq) != RUNTIME_INF) {
+ raw_spin_lock(&rt_rq->rt_runtime_lock);
+ rt_rq->rt_time += delta_exec;
+ if (sched_rt_runtime_exceeded(rt_rq))
+ resched_task(curr);
+ raw_spin_unlock(&rt_rq->rt_runtime_lock);
+ }
+ }
+}
+
+#if defined CONFIG_SMP
+
+static struct task_struct *pick_next_highest_task_rt(struct rq *rq, int cpu);
+
+static inline int next_prio(struct rq *rq)
+{
+ struct task_struct *next = pick_next_highest_task_rt(rq, rq->cpu);
+
+ if (next && rt_prio(next->prio))
+ return next->prio;
+ else
+ return MAX_RT_PRIO;
+}
+
+static void
+inc_rt_prio_smp(struct rt_rq *rt_rq, int prio, int prev_prio)
+{
+ struct rq *rq = rq_of_rt_rq(rt_rq);
+
+ if (prio < prev_prio) {
+
+ /*
+ * If the new task is higher in priority than anything on the
+ * run-queue, we know that the previous high becomes our
+ * next-highest.
+ */
+ rt_rq->highest_prio.next = prev_prio;
+
+ if (rq->online)
+ cpupri_set(&rq->rd->cpupri, rq->cpu, prio);
+
+ } else if (prio == rt_rq->highest_prio.curr)
+ /*
+ * If the next task is equal in priority to the highest on
+ * the run-queue, then we implicitly know that the next highest
+ * task cannot be any lower than current
+ */
+ rt_rq->highest_prio.next = prio;
+ else if (prio < rt_rq->highest_prio.next)
+ /*
+ * Otherwise, we need to recompute next-highest
+ */
+ rt_rq->highest_prio.next = next_prio(rq);
+}
+
+static void
+dec_rt_prio_smp(struct rt_rq *rt_rq, int prio, int prev_prio)
+{
+ struct rq *rq = rq_of_rt_rq(rt_rq);
+
+ if (rt_rq->rt_nr_running && (prio <= rt_rq->highest_prio.next))
+ rt_rq->highest_prio.next = next_prio(rq);
+
+ if (rq->online && rt_rq->highest_prio.curr != prev_prio)
+ cpupri_set(&rq->rd->cpupri, rq->cpu, rt_rq->highest_prio.curr);
+}
+
+#else /* CONFIG_SMP */
+
+static inline
+void inc_rt_prio_smp(struct rt_rq *rt_rq, int prio, int prev_prio) {}
+static inline
+void dec_rt_prio_smp(struct rt_rq *rt_rq, int prio, int prev_prio) {}
+
+#endif /* CONFIG_SMP */
+
+#if defined CONFIG_SMP || defined CONFIG_RT_GROUP_SCHED
+static void
+inc_rt_prio(struct rt_rq *rt_rq, int prio)
+{
+ int prev_prio = rt_rq->highest_prio.curr;
+
+ if (prio < prev_prio)
+ rt_rq->highest_prio.curr = prio;
+
+ inc_rt_prio_smp(rt_rq, prio, prev_prio);
+}
+
+static void
+dec_rt_prio(struct rt_rq *rt_rq, int prio)
+{
+ int prev_prio = rt_rq->highest_prio.curr;
+
+ if (rt_rq->rt_nr_running) {
+
+ WARN_ON(prio < prev_prio);
+
+ /*
+ * This may have been our highest task, and therefore
+ * we may have some recomputation to do
+ */
+ if (prio == prev_prio) {
+ struct rt_prio_array *array = &rt_rq->active;
+
+ rt_rq->highest_prio.curr =
+ sched_find_first_bit(array->bitmap);
+ }
+
+ } else
+ rt_rq->highest_prio.curr = MAX_RT_PRIO;
+
+ dec_rt_prio_smp(rt_rq, prio, prev_prio);
+}
+
+#else
+
+static inline void inc_rt_prio(struct rt_rq *rt_rq, int prio) {}
+static inline void dec_rt_prio(struct rt_rq *rt_rq, int prio) {}
+
+#endif /* CONFIG_SMP || CONFIG_RT_GROUP_SCHED */
+
+#ifdef CONFIG_RT_GROUP_SCHED
+
+static void
+inc_rt_group(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq)
+{
+ if (rt_se_boosted(rt_se))
+ rt_rq->rt_nr_boosted++;
+
+ if (rt_rq->tg)
+ start_rt_bandwidth(&rt_rq->tg->rt_bandwidth);
+}
+
+static void
+dec_rt_group(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq)
+{
+ if (rt_se_boosted(rt_se))
+ rt_rq->rt_nr_boosted--;
+
+ WARN_ON(!rt_rq->rt_nr_running && rt_rq->rt_nr_boosted);
+}
+
+#else /* CONFIG_RT_GROUP_SCHED */
+
+static void
+inc_rt_group(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq)
+{
+ start_rt_bandwidth(&def_rt_bandwidth);
}
-static inline void inc_rt_tasks(struct task_struct *p, struct rq *rq)
-{
- WARN_ON(!rt_task(p));
- rq->rt.rt_nr_running++;
-#ifdef CONFIG_SMP
- if (p->prio < rq->rt.highest_prio)
- rq->rt.highest_prio = p->prio;
-#endif /* CONFIG_SMP */
+static inline
+void dec_rt_group(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq) {}
+
+#endif /* CONFIG_RT_GROUP_SCHED */
+
+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++;
+
+ inc_rt_prio(rt_rq, prio);
+ inc_rt_migration(rt_se, rt_rq);
+ inc_rt_group(rt_se, rt_rq);
+}
+
+static inline
+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--;
+
+ dec_rt_prio(rt_rq, rt_se_prio(rt_se));
+ dec_rt_migration(rt_se, rt_rq);
+ dec_rt_group(rt_se, rt_rq);
+}
+
+static void __enqueue_rt_entity(struct sched_rt_entity *rt_se, bool head)
+{
+ 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);
+ struct list_head *queue = array->queue + rt_se_prio(rt_se);
+
+ /*
+ * Don't enqueue the group if its throttled, or when empty.
+ * The latter is a consequence of the former when a child group
+ * get throttled and the current group doesn't have any other
+ * active members.
+ */
+ if (group_rq && (rt_rq_throttled(group_rq) || !group_rq->rt_nr_running))
+ return;
+
+ if (head)
+ list_add(&rt_se->run_list, queue);
+ else
+ list_add_tail(&rt_se->run_list, queue);
+ __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.
+ */
+static void dequeue_rt_stack(struct sched_rt_entity *rt_se)
+{
+ struct sched_rt_entity *back = NULL;
+
+ for_each_sched_rt_entity(rt_se) {
+ rt_se->back = back;
+ back = rt_se;
+ }
+
+ for (rt_se = back; rt_se; rt_se = rt_se->back) {
+ if (on_rt_rq(rt_se))
+ __dequeue_rt_entity(rt_se);
+ }
}
-static inline void dec_rt_tasks(struct task_struct *p, struct rq *rq)
+static void enqueue_rt_entity(struct sched_rt_entity *rt_se, bool head)
{
- 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) {
- struct rt_prio_array *array;
-
- WARN_ON(p->prio < rq->rt.highest_prio);
- if (p->prio == rq->rt.highest_prio) {
- /* recalculate */
- array = &rq->rt.active;
- rq->rt.highest_prio =
- sched_find_first_bit(array->bitmap);
- } /* otherwise leave rq->highest prio alone */
- } else
- rq->rt.highest_prio = MAX_RT_PRIO;
-#endif /* CONFIG_SMP */
+ dequeue_rt_stack(rt_se);
+ for_each_sched_rt_entity(rt_se)
+ __enqueue_rt_entity(rt_se, head);
}
-static void enqueue_task_rt(struct rq *rq, struct task_struct *p, int wakeup)
+static void dequeue_rt_entity(struct sched_rt_entity *rt_se)
{
- struct rt_prio_array *array = &rq->rt.active;
+ dequeue_rt_stack(rt_se);
- list_add_tail(&p->run_list, array->queue + p->prio);
- __set_bit(p->prio, array->bitmap);
- inc_cpu_load(rq, p->se.load.weight);
+ for_each_sched_rt_entity(rt_se) {
+ struct rt_rq *rt_rq = group_rt_rq(rt_se);
- inc_rt_tasks(p, rq);
+ if (rt_rq && rt_rq->rt_nr_running)
+ __enqueue_rt_entity(rt_se, false);
+ }
}
/*
* Adding/removing a task to/from a priority array:
*/
+static void
+enqueue_task_rt(struct rq *rq, struct task_struct *p, int wakeup, bool head)
+{
+ struct sched_rt_entity *rt_se = &p->rt;
+
+ if (wakeup)
+ rt_se->timeout = 0;
+
+ enqueue_rt_entity(rt_se, head);
+
+ if (!task_current(rq, p) && p->rt.nr_cpus_allowed > 1)
+ enqueue_pushable_task(rq, p);
+}
+
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;
update_curr_rt(rq);
+ dequeue_rt_entity(rt_se);
- list_del(&p->run_list);
- if (list_empty(array->queue + p->prio))
- __clear_bit(p->prio, array->bitmap);
- dec_cpu_load(rq, p->se.load.weight);
-
- dec_rt_tasks(p, rq);
+ dequeue_pushable_task(rq, p);
}
/*
* Put task to the end of the run list without the overhead of dequeue
* followed by enqueue.
*/
-static void requeue_task_rt(struct rq *rq, struct task_struct *p)
+static void
+requeue_rt_entity(struct rt_rq *rt_rq, struct sched_rt_entity *rt_se, int head)
{
- struct rt_prio_array *array = &rq->rt.active;
+ if (on_rt_rq(rt_se)) {
+ struct rt_prio_array *array = &rt_rq->active;
+ struct list_head *queue = array->queue + rt_se_prio(rt_se);
- list_move_tail(&p->run_list, array->queue + p->prio);
+ if (head)
+ list_move(&rt_se->run_list, queue);
+ else
+ list_move_tail(&rt_se->run_list, queue);
+ }
}
-static void
-yield_task_rt(struct rq *rq)
+static void requeue_task_rt(struct rq *rq, struct task_struct *p, int head)
+{
+ struct sched_rt_entity *rt_se = &p->rt;
+ struct rt_rq *rt_rq;
+
+ for_each_sched_rt_entity(rt_se) {
+ rt_rq = rt_rq_of_se(rt_se);
+ requeue_rt_entity(rt_rq, rt_se, head);
+ }
+}
+
+static void yield_task_rt(struct rq *rq)
+{
+ requeue_task_rt(rq, rq->curr, 0);
+}
+
+#ifdef CONFIG_SMP
+static int find_lowest_rq(struct task_struct *task);
+
+static int select_task_rq_rt(struct task_struct *p, int sd_flag, int flags)
+{
+ struct rq *rq = task_rq(p);
+
+ if (sd_flag != SD_BALANCE_WAKE)
+ return smp_processor_id();
+
+ /*
+ * If the current task is an RT task, then
+ * try to see if we can wake this RT task up on another
+ * runqueue. Otherwise simply start this RT task
+ * on its current runqueue.
+ *
+ * We want to avoid overloading runqueues. Even if
+ * the RT task is of higher priority than the current RT task.
+ * RT tasks behave differently than other tasks. If
+ * one gets preempted, we try to push it off to another queue.
+ * So trying to keep a preempting RT task on the same
+ * cache hot CPU will force the running RT task to
+ * a cold CPU. So we waste all the cache for the lower
+ * RT task in hopes of saving some of a RT task
+ * that is just being woken and probably will have
+ * cold cache anyway.
+ */
+ if (unlikely(rt_task(rq->curr)) &&
+ (p->rt.nr_cpus_allowed > 1)) {
+ int cpu = find_lowest_rq(p);
+
+ return (cpu == -1) ? task_cpu(p) : cpu;
+ }
+
+ /*
+ * Otherwise, just let it ride on the affined RQ and the
+ * post-schedule router will push the preempted task away
+ */
+ return task_cpu(p);
+}
+
+static void check_preempt_equal_prio(struct rq *rq, struct task_struct *p)
{
- requeue_task_rt(rq, rq->curr);
+ if (rq->curr->rt.nr_cpus_allowed == 1)
+ return;
+
+ if (p->rt.nr_cpus_allowed != 1
+ && cpupri_find(&rq->rd->cpupri, p, NULL))
+ return;
+
+ if (!cpupri_find(&rq->rd->cpupri, rq->curr, NULL))
+ return;
+
+ /*
+ * There appears to be other cpus that can accept
+ * current and none to run 'p', so lets reschedule
+ * to try and push current away:
+ */
+ requeue_task_rt(rq, p, 1);
+ resched_task(rq->curr);
}
+#endif /* CONFIG_SMP */
+
/*
* Preempt the current task with a newly woken task if needed:
*/
-static void check_preempt_curr_rt(struct rq *rq, struct task_struct *p)
+static void check_preempt_curr_rt(struct rq *rq, struct task_struct *p, int flags)
{
- if (p->prio < rq->curr->prio)
+ if (p->prio < rq->curr->prio) {
resched_task(rq->curr);
+ return;
+ }
+
+#ifdef CONFIG_SMP
+ /*
+ * If:
+ *
+ * - the newly woken task is of equal priority to the current task
+ * - the newly woken task is non-migratable while current is migratable
+ * - current will be preempted on the next reschedule
+ *
+ * we should check to see if current can readily move to a different
+ * cpu. If so, we will reschedule to allow the push logic to try
+ * to move current somewhere else, making room for our non-migratable
+ * task.
+ */
+ if (p->prio == rq->curr->prio && !need_resched())
+ check_preempt_equal_prio(rq, p);
+#endif
}
-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, 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 struct task_struct *pick_next_task_rt(struct rq *rq)
+{
+ struct task_struct *p = _pick_next_task_rt(rq);
+
+ /* The running task is never eligible for pushing */
+ if (p)
+ dequeue_pushable_task(rq, p);
+
+#ifdef CONFIG_SMP
+ /*
+ * We detect this state here so that we can avoid taking the RQ
+ * lock again later if there is no need to push
+ */
+ rq->post_schedule = has_pushable_tasks(rq);
+#endif
+
+ return p;
+}
+
static void put_prev_task_rt(struct rq *rq, struct task_struct *p)
{
update_curr_rt(rq);
p->se.exec_start = 0;
+
+ /*
+ * The previous task needs to be made eligible for pushing
+ * if it is still active
+ */
+ if (p->se.on_rq && p->rt.nr_cpus_allowed > 1)
+ enqueue_pushable_task(rq, p);
}
#ifdef CONFIG_SMP
-/*
- * Load-balancing iterator. Note: while the runqueue stays locked
- * during the whole iteration, the current task might be
- * dequeued so the iterator has to be dequeue-safe. Here we
- * achieve that by always pre-iterating before returning
- * the current task:
- */
-static struct task_struct *load_balance_start_rt(void *arg)
+
+/* Only try algorithms three times */
+#define RT_MAX_TRIES 3
+
+static void deactivate_task(struct rq *rq, struct task_struct *p, int sleep);
+
+static int pick_rt_task(struct rq *rq, struct task_struct *p, int cpu)
{
- struct rq *rq = arg;
- struct rt_prio_array *array = &rq->rt.active;
- struct list_head *head, *curr;
- struct task_struct *p;
+ if (!task_running(rq, p) &&
+ (cpu < 0 || cpumask_test_cpu(cpu, &p->cpus_allowed)) &&
+ (p->rt.nr_cpus_allowed > 1))
+ return 1;
+ return 0;
+}
+
+/* Return the second highest RT task, NULL otherwise */
+static struct task_struct *pick_next_highest_task_rt(struct rq *rq, int cpu)
+{
+ struct task_struct *next = NULL;
+ struct sched_rt_entity *rt_se;
+ struct rt_prio_array *array;
+ struct rt_rq *rt_rq;
int idx;
- idx = sched_find_first_bit(array->bitmap);
- if (idx >= MAX_RT_PRIO)
- return NULL;
+ 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;
+
+ if (!rt_entity_is_task(rt_se))
+ continue;
+
+ 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;
+ }
+ }
+
+ return next;
+}
+
+static DEFINE_PER_CPU(cpumask_var_t, local_cpu_mask);
+
+static int find_lowest_rq(struct task_struct *task)
+{
+ struct sched_domain *sd;
+ struct cpumask *lowest_mask = __get_cpu_var(local_cpu_mask);
+ int this_cpu = smp_processor_id();
+ int cpu = task_cpu(task);
+
+ if (task->rt.nr_cpus_allowed == 1)
+ return -1; /* No other targets possible */
+
+ if (!cpupri_find(&task_rq(task)->rd->cpupri, task, lowest_mask))
+ return -1; /* No targets found */
+
+ /*
+ * At this point we have built a mask of cpus representing the
+ * lowest priority tasks in the system. Now we want to elect
+ * the best one based on our affinity and topology.
+ *
+ * We prioritize the last cpu that the task executed on since
+ * it is most likely cache-hot in that location.
+ */
+ if (cpumask_test_cpu(cpu, lowest_mask))
+ return cpu;
+
+ /*
+ * Otherwise, we consult the sched_domains span maps to figure
+ * out which cpu is logically closest to our hot cache data.
+ */
+ if (!cpumask_test_cpu(this_cpu, lowest_mask))
+ this_cpu = -1; /* Skip this_cpu opt if not among lowest */
+
+ for_each_domain(cpu, sd) {
+ if (sd->flags & SD_WAKE_AFFINE) {
+ int best_cpu;
+
+ /*
+ * "this_cpu" is cheaper to preempt than a
+ * remote processor.
+ */
+ if (this_cpu != -1 &&
+ cpumask_test_cpu(this_cpu, sched_domain_span(sd)))
+ return this_cpu;
+
+ best_cpu = cpumask_first_and(lowest_mask,
+ sched_domain_span(sd));
+ if (best_cpu < nr_cpu_ids)
+ return best_cpu;
+ }
+ }
+
+ /*
+ * And finally, if there were no matches within the domains
+ * just give the caller *something* to work with from the compatible
+ * locations.
+ */
+ if (this_cpu != -1)
+ return this_cpu;
+
+ cpu = cpumask_any(lowest_mask);
+ if (cpu < nr_cpu_ids)
+ return cpu;
+ return -1;
+}
+
+/* Will lock the rq it finds */
+static struct rq *find_lock_lowest_rq(struct task_struct *task, struct rq *rq)
+{
+ struct rq *lowest_rq = NULL;
+ int tries;
+ int cpu;
+
+ for (tries = 0; tries < RT_MAX_TRIES; tries++) {
+ cpu = find_lowest_rq(task);
+
+ if ((cpu == -1) || (cpu == rq->cpu))
+ break;
+
+ lowest_rq = cpu_rq(cpu);
+
+ /* if the prio of this runqueue changed, try again */
+ if (double_lock_balance(rq, lowest_rq)) {
+ /*
+ * We had to unlock the run queue. In
+ * the mean time, task could have
+ * migrated already or had its affinity changed.
+ * Also make sure that it wasn't scheduled on its rq.
+ */
+ if (unlikely(task_rq(task) != rq ||
+ !cpumask_test_cpu(lowest_rq->cpu,
+ &task->cpus_allowed) ||
+ task_running(rq, task) ||
+ !task->se.on_rq)) {
+
+ raw_spin_unlock(&lowest_rq->lock);
+ lowest_rq = NULL;
+ break;
+ }
+ }
+
+ /* If this rq is still suitable use it. */
+ if (lowest_rq->rt.highest_prio.curr > task->prio)
+ break;
+
+ /* try again */
+ double_unlock_balance(rq, lowest_rq);
+ lowest_rq = NULL;
+ }
+
+ return lowest_rq;
+}
+
+static struct task_struct *pick_next_pushable_task(struct rq *rq)
+{
+ struct task_struct *p;
- head = array->queue + idx;
- curr = head->prev;
+ if (!has_pushable_tasks(rq))
+ return NULL;
- p = list_entry(curr, struct task_struct, run_list);
+ p = plist_first_entry(&rq->rt.pushable_tasks,
+ struct task_struct, pushable_tasks);
- curr = curr->prev;
+ BUG_ON(rq->cpu != task_cpu(p));
+ BUG_ON(task_current(rq, p));
+ BUG_ON(p->rt.nr_cpus_allowed <= 1);
- rq->rt.rt_load_balance_idx = idx;
- rq->rt.rt_load_balance_head = head;
- rq->rt.rt_load_balance_curr = curr;
+ BUG_ON(!p->se.on_rq);
+ BUG_ON(!rt_task(p));
return p;
}
-static struct task_struct *load_balance_next_rt(void *arg)
+/*
+ * If the current CPU has more than one RT task, see if the non
+ * running task can migrate over to a CPU that is running a task
+ * of lesser priority.
+ */
+static int push_rt_task(struct rq *rq)
+{
+ struct task_struct *next_task;
+ struct rq *lowest_rq;
+
+ if (!rq->rt.overloaded)
+ return 0;
+
+ next_task = pick_next_pushable_task(rq);
+ if (!next_task)
+ return 0;
+
+ retry:
+ if (unlikely(next_task == rq->curr)) {
+ WARN_ON(1);
+ return 0;
+ }
+
+ /*
+ * It's possible that the next_task slipped in of
+ * higher priority than current. If that's the case
+ * just reschedule current.
+ */
+ if (unlikely(next_task->prio < rq->curr->prio)) {
+ resched_task(rq->curr);
+ return 0;
+ }
+
+ /* We might release rq lock */
+ get_task_struct(next_task);
+
+ /* find_lock_lowest_rq locks the rq if found */
+ lowest_rq = find_lock_lowest_rq(next_task, rq);
+ if (!lowest_rq) {
+ struct task_struct *task;
+ /*
+ * find lock_lowest_rq releases rq->lock
+ * so it is possible that next_task has migrated.
+ *
+ * We need to make sure that the task is still on the same
+ * run-queue and is also still the next task eligible for
+ * pushing.
+ */
+ task = pick_next_pushable_task(rq);
+ if (task_cpu(next_task) == rq->cpu && task == next_task) {
+ /*
+ * If we get here, the task hasnt moved at all, but
+ * it has failed to push. We will not try again,
+ * since the other cpus will pull from us when they
+ * are ready.
+ */
+ dequeue_pushable_task(rq, next_task);
+ goto out;
+ }
+
+ if (!task)
+ /* No more tasks, just exit */
+ goto out;
+
+ /*
+ * Something has shifted, try again.
+ */
+ put_task_struct(next_task);
+ next_task = task;
+ goto retry;
+ }
+
+ deactivate_task(rq, next_task, 0);
+ set_task_cpu(next_task, lowest_rq->cpu);
+ activate_task(lowest_rq, next_task, 0);
+
+ resched_task(lowest_rq->curr);
+
+ double_unlock_balance(rq, lowest_rq);
+
+out:
+ put_task_struct(next_task);
+
+ return 1;
+}
+
+static void push_rt_tasks(struct rq *rq)
+{
+ /* push_rt_task will return true if it moved an RT */
+ while (push_rt_task(rq))
+ ;
+}
+
+static int pull_rt_task(struct rq *this_rq)
{
- struct rq *rq = arg;
- struct rt_prio_array *array = &rq->rt.active;
- struct list_head *head, *curr;
+ int this_cpu = this_rq->cpu, ret = 0, cpu;
struct task_struct *p;
- int idx;
+ struct rq *src_rq;
+
+ if (likely(!rt_overloaded(this_rq)))
+ return 0;
+
+ for_each_cpu(cpu, this_rq->rd->rto_mask) {
+ if (this_cpu == cpu)
+ continue;
+
+ src_rq = cpu_rq(cpu);
+
+ /*
+ * Don't bother taking the src_rq->lock if the next highest
+ * task is known to be lower-priority than our current task.
+ * This may look racy, but if this value is about to go
+ * logically higher, the src_rq will push this task away.
+ * And if its going logically lower, we do not care
+ */
+ if (src_rq->rt.highest_prio.next >=
+ this_rq->rt.highest_prio.curr)
+ continue;
+
+ /*
+ * We can potentially drop this_rq's lock in
+ * double_lock_balance, and another CPU could
+ * alter this_rq
+ */
+ double_lock_balance(this_rq, src_rq);
+
+ /*
+ * Are there still pullable RT tasks?
+ */
+ if (src_rq->rt.rt_nr_running <= 1)
+ goto skip;
+
+ p = pick_next_highest_task_rt(src_rq, this_cpu);
+
+ /*
+ * Do we have an RT task that preempts
+ * the to-be-scheduled task?
+ */
+ if (p && (p->prio < this_rq->rt.highest_prio.curr)) {
+ WARN_ON(p == src_rq->curr);
+ WARN_ON(!p->se.on_rq);
+
+ /*
+ * There's a chance that p is higher in priority
+ * than what's currently running on its cpu.
+ * This is just that p is wakeing up and hasn't
+ * had a chance to schedule. We only pull
+ * p if it is lower in priority than the
+ * current task on the run queue
+ */
+ if (p->prio < src_rq->curr->prio)
+ goto skip;
+
+ ret = 1;
+
+ deactivate_task(src_rq, p, 0);
+ set_task_cpu(p, this_cpu);
+ activate_task(this_rq, p, 0);
+ /*
+ * We continue with the search, just in
+ * case there's an even higher prio task
+ * in another runqueue. (low likelyhood
+ * but possible)
+ */
+ }
+ skip:
+ double_unlock_balance(this_rq, src_rq);
+ }
+
+ return ret;
+}
+
+static void pre_schedule_rt(struct rq *rq, struct task_struct *prev)
+{
+ /* Try to pull RT tasks here if we lower this rq's prio */
+ if (unlikely(rt_task(prev)) && rq->rt.highest_prio.curr > prev->prio)
+ pull_rt_task(rq);
+}
+
+static void post_schedule_rt(struct rq *rq)
+{
+ push_rt_tasks(rq);
+}
+
+/*
+ * If we are not running and we are not going to reschedule soon, we should
+ * try to push tasks away now
+ */
+static void task_woken_rt(struct rq *rq, struct task_struct *p)
+{
+ if (!task_running(rq, p) &&
+ !test_tsk_need_resched(rq->curr) &&
+ has_pushable_tasks(rq) &&
+ p->rt.nr_cpus_allowed > 1)
+ push_rt_tasks(rq);
+}
+
+static void set_cpus_allowed_rt(struct task_struct *p,
+ const struct cpumask *new_mask)
+{
+ int weight = cpumask_weight(new_mask);
- idx = rq->rt.rt_load_balance_idx;
- head = rq->rt.rt_load_balance_head;
- curr = rq->rt.rt_load_balance_curr;
+ BUG_ON(!rt_task(p));
/*
- * If we arrived back to the head again then
- * iterate to the next queue (if any):
+ * Update the migration status of the RQ if we have an RT task
+ * which is running AND changing its weight value.
*/
- if (unlikely(head == curr)) {
- int next_idx = find_next_bit(array->bitmap, MAX_RT_PRIO, idx+1);
+ if (p->se.on_rq && (weight != p->rt.nr_cpus_allowed)) {
+ struct rq *rq = task_rq(p);
- if (next_idx >= MAX_RT_PRIO)
- return NULL;
+ if (!task_current(rq, p)) {
+ /*
+ * Make sure we dequeue this task from the pushable list
+ * before going further. It will either remain off of
+ * the list because we are no longer pushable, or it
+ * will be requeued.
+ */
+ if (p->rt.nr_cpus_allowed > 1)
+ dequeue_pushable_task(rq, p);
- idx = next_idx;
- head = array->queue + idx;
- curr = head->prev;
+ /*
+ * Requeue if our weight is changing and still > 1
+ */
+ if (weight > 1)
+ enqueue_pushable_task(rq, p);
- rq->rt.rt_load_balance_idx = idx;
- rq->rt.rt_load_balance_head = head;
+ }
+
+ if ((p->rt.nr_cpus_allowed <= 1) && (weight > 1)) {
+ rq->rt.rt_nr_migratory++;
+ } else if ((p->rt.nr_cpus_allowed > 1) && (weight <= 1)) {
+ BUG_ON(!rq->rt.rt_nr_migratory);
+ rq->rt.rt_nr_migratory--;
+ }
+
+ update_rt_migration(&rq->rt);
}
- p = list_entry(curr, struct task_struct, run_list);
+ cpumask_copy(&p->cpus_allowed, new_mask);
+ p->rt.nr_cpus_allowed = weight;
+}
+
+/* Assumes rq->lock is held */
+static void rq_online_rt(struct rq *rq)
+{
+ if (rq->rt.overloaded)
+ rt_set_overload(rq);
- curr = curr->prev;
+ __enable_runtime(rq);
- rq->rt.rt_load_balance_curr = curr;
+ cpupri_set(&rq->rd->cpupri, rq->cpu, rq->rt.highest_prio.curr);
+}
- return p;
+/* Assumes rq->lock is held */
+static void rq_offline_rt(struct rq *rq)
+{
+ if (rq->rt.overloaded)
+ rt_clear_overload(rq);
+
+ __disable_runtime(rq);
+
+ cpupri_set(&rq->rd->cpupri, rq->cpu, CPUPRI_INVALID);
+}
+
+/*
+ * When switch from the rt queue, we bring ourselves to a position
+ * that we might want to pull RT tasks from other runqueues.
+ */
+static void switched_from_rt(struct rq *rq, struct task_struct *p,
+ int running)
+{
+ /*
+ * If there are other RT tasks then we will reschedule
+ * and the scheduling of the other RT tasks will handle
+ * the balancing. But if we are the last RT task
+ * we may need to handle the pulling of RT tasks
+ * now.
+ */
+ if (!rq->rt.rt_nr_running)
+ pull_rt_task(rq);
+}
+
+static inline void init_sched_rt_class(void)
+{
+ unsigned int i;
+
+ for_each_possible_cpu(i)
+ zalloc_cpumask_var_node(&per_cpu(local_cpu_mask, i),
+ GFP_KERNEL, cpu_to_node(i));
}
+#endif /* CONFIG_SMP */
-static unsigned long
-load_balance_rt(struct rq *this_rq, int this_cpu, struct rq *busiest,
- unsigned long max_load_move,
- struct sched_domain *sd, enum cpu_idle_type idle,
- int *all_pinned, int *this_best_prio)
+/*
+ * When switching a task to RT, we may overload the runqueue
+ * with RT tasks. In this case we try to push them off to
+ * other runqueues.
+ */
+static void switched_to_rt(struct rq *rq, struct task_struct *p,
+ int running)
{
- struct rq_iterator rt_rq_iterator;
+ int check_resched = 1;
- rt_rq_iterator.start = load_balance_start_rt;
- rt_rq_iterator.next = load_balance_next_rt;
- /* pass 'busiest' rq argument into
- * load_balance_[start|next]_rt iterators
+ /*
+ * If we are already running, then there's nothing
+ * that needs to be done. But if we are not running
+ * we may need to preempt the current running task.
+ * If that current running task is also an RT task
+ * then see if we can move to another run queue.
*/
- rt_rq_iterator.arg = busiest;
+ if (!running) {
+#ifdef CONFIG_SMP
+ if (rq->rt.overloaded && push_rt_task(rq) &&
+ /* Don't resched if we changed runqueues */
+ rq != task_rq(p))
+ check_resched = 0;
+#endif /* CONFIG_SMP */
+ if (check_resched && p->prio < rq->curr->prio)
+ resched_task(rq->curr);
+ }
+}
- return balance_tasks(this_rq, this_cpu, busiest, max_load_move, sd,
- idle, all_pinned, this_best_prio, &rt_rq_iterator);
+/*
+ * Priority of the task has changed. This may cause
+ * us to initiate a push or pull.
+ */
+static void prio_changed_rt(struct rq *rq, struct task_struct *p,
+ int oldprio, int running)
+{
+ if (running) {
+#ifdef CONFIG_SMP
+ /*
+ * If our priority decreases while running, we
+ * may need to pull tasks to this runqueue.
+ */
+ if (oldprio < p->prio)
+ pull_rt_task(rq);
+ /*
+ * If there's a higher priority task waiting to run
+ * 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.curr && rq->curr == p)
+ resched_task(p);
+#else
+ /* For UP simply resched on drop of prio */
+ if (oldprio < p->prio)
+ resched_task(p);
+#endif /* CONFIG_SMP */
+ } else {
+ /*
+ * This task is not running, but if it is
+ * greater than the current running task
+ * then reschedule.
+ */
+ if (p->prio < rq->curr->prio)
+ resched_task(rq->curr);
+ }
}
-static int
-move_one_task_rt(struct rq *this_rq, int this_cpu, struct rq *busiest,
- struct sched_domain *sd, enum cpu_idle_type idle)
+static void watchdog(struct rq *rq, struct task_struct *p)
{
- struct rq_iterator rt_rq_iterator;
+ unsigned long soft, hard;
+
+ if (!p->signal)
+ return;
+
+ /* max may change after cur was read, this will be fixed next tick */
+ soft = task_rlimit(p, RLIMIT_RTTIME);
+ hard = task_rlimit_max(p, RLIMIT_RTTIME);
- rt_rq_iterator.start = load_balance_start_rt;
- rt_rq_iterator.next = load_balance_next_rt;
- rt_rq_iterator.arg = busiest;
+ if (soft != RLIM_INFINITY) {
+ unsigned long next;
- return iter_move_one_task(this_rq, this_cpu, busiest, sd, idle,
- &rt_rq_iterator);
+ p->rt.timeout++;
+ next = DIV_ROUND_UP(min(soft, hard), USEC_PER_SEC/HZ);
+ if (p->rt.timeout > next)
+ p->cputime_expires.sched_exp = p->se.sum_exec_runtime;
+ }
}
-#endif
-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.
if (p->policy != SCHED_RR)
return;
- if (--p->time_slice)
+ if (--p->rt.time_slice)
return;
- p->time_slice = DEF_TIMESLICE;
+ p->rt.time_slice = DEF_TIMESLICE;
/*
* Requeue to the end of queue if we are not the only element
* on the queue:
*/
- if (p->run_list.prev != p->run_list.next) {
- requeue_task_rt(rq, p);
+ if (p->rt.run_list.prev != p->rt.run_list.next) {
+ requeue_task_rt(rq, p, 0);
set_tsk_need_resched(p);
}
}
struct task_struct *p = rq->curr;
p->se.exec_start = rq->clock;
+
+ /* The running task is never eligible for pushing */
+ dequeue_pushable_task(rq, p);
+}
+
+static unsigned int get_rr_interval_rt(struct rq *rq, struct task_struct *task)
+{
+ /*
+ * Time slice is 0 for SCHED_FIFO tasks
+ */
+ if (task->policy == SCHED_RR)
+ return DEF_TIMESLICE;
+ else
+ return 0;
}
-const struct sched_class rt_sched_class = {
+static const struct sched_class rt_sched_class = {
.next = &fair_sched_class,
.enqueue_task = enqueue_task_rt,
.dequeue_task = dequeue_task_rt,
.put_prev_task = put_prev_task_rt,
#ifdef CONFIG_SMP
- .load_balance = load_balance_rt,
- .move_one_task = move_one_task_rt,
+ .select_task_rq = select_task_rq_rt,
+
+ .set_cpus_allowed = set_cpus_allowed_rt,
+ .rq_online = rq_online_rt,
+ .rq_offline = rq_offline_rt,
+ .pre_schedule = pre_schedule_rt,
+ .post_schedule = post_schedule_rt,
+ .task_woken = task_woken_rt,
+ .switched_from = switched_from_rt,
#endif
.set_curr_task = set_curr_task_rt,
.task_tick = task_tick_rt,
+
+ .get_rr_interval = get_rr_interval_rt,
+
+ .prio_changed = prio_changed_rt,
+ .switched_to = switched_to_rt,
};
+
+#ifdef CONFIG_SCHED_DEBUG
+extern void print_rt_rq(struct seq_file *m, int cpu, struct rt_rq *rt_rq);
+
+static void print_rt_stats(struct seq_file *m, int cpu)
+{
+ struct rt_rq *rt_rq;
+
+ rcu_read_lock();
+ for_each_leaf_rt_rq(rt_rq, cpu_rq(cpu))
+ print_rt_rq(m, cpu, rt_rq);
+ rcu_read_unlock();
+}
+#endif /* CONFIG_SCHED_DEBUG */
+
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff