perf_event: Provide vmalloc() based mmap() backing
[safe/jmp/linux-2.6] / kernel / sched_rt.c
index 48d1f6e..a4d790c 100644 (file)
@@ -3,13 +3,18 @@
  * 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);
 }
 
-#ifdef CONFIG_RT_GROUP_SCHED
-
 static inline struct rq *rq_of_rt_rq(struct rt_rq *rt_rq)
 {
        return rt_rq->rq;
@@ -22,6 +27,13 @@ static inline struct rt_rq *rt_rq_of_se(struct sched_rt_entity *rt_se)
 
 #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);
@@ -73,7 +85,7 @@ static inline void rt_clear_overload(struct rq *rq)
 
 static void update_rt_migration(struct rt_rq *rt_rq)
 {
-       if (rt_rq->rt_nr_migratory && (rt_rq->rt_nr_running > 1)) {
+       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;
@@ -86,6 +98,12 @@ static void update_rt_migration(struct rt_rq *rt_rq)
 
 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++;
 
@@ -94,6 +112,12 @@ static void inc_rt_migration(struct sched_rt_entity *rt_se, struct rt_rq *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--;
 
@@ -112,6 +136,11 @@ 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)
@@ -586,6 +615,8 @@ static void update_curr_rt(struct rq *rq)
        curr->se.exec_start = rq->clock;
        cpuacct_charge(curr, delta_exec);
 
+       sched_rt_avg_update(rq, delta_exec);
+
        if (!rt_bandwidth_enabled())
                return;
 
@@ -858,8 +889,6 @@ static void enqueue_task_rt(struct rq *rq, struct task_struct *p, int wakeup)
 
        if (!task_current(rq, p) && p->rt.nr_cpus_allowed > 1)
                enqueue_pushable_task(rq, p);
-
-       inc_cpu_load(rq, p->se.load.weight);
 }
 
 static void dequeue_task_rt(struct rq *rq, struct task_struct *p, int sleep)
@@ -870,8 +899,6 @@ static void dequeue_task_rt(struct rq *rq, struct task_struct *p, int sleep)
        dequeue_rt_entity(rt_se);
 
        dequeue_pushable_task(rq, p);
-
-       dec_cpu_load(rq, p->se.load.weight);
 }
 
 /*
@@ -911,10 +938,13 @@ static void yield_task_rt(struct rq *rq)
 #ifdef CONFIG_SMP
 static int find_lowest_rq(struct task_struct *task);
 
-static int select_task_rq_rt(struct task_struct *p, int sync)
+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
@@ -948,20 +978,15 @@ static int select_task_rq_rt(struct task_struct *p, int sync)
 
 static void check_preempt_equal_prio(struct rq *rq, struct task_struct *p)
 {
-       cpumask_var_t mask;
-
        if (rq->curr->rt.nr_cpus_allowed == 1)
                return;
 
-       if (!alloc_cpumask_var(&mask, GFP_ATOMIC))
-               return;
-
        if (p->rt.nr_cpus_allowed != 1
-           && cpupri_find(&rq->rd->cpupri, p, mask))
-               goto free;
+           && cpupri_find(&rq->rd->cpupri, p, NULL))
+               return;
 
-       if (!cpupri_find(&rq->rd->cpupri, rq->curr, mask))
-               goto free;
+       if (!cpupri_find(&rq->rd->cpupri, rq->curr, NULL))
+               return;
 
        /*
         * There appears to be other cpus that can accept
@@ -970,8 +995,6 @@ static void check_preempt_equal_prio(struct rq *rq, struct task_struct *p)
         */
        requeue_task_rt(rq, p, 1);
        resched_task(rq->curr);
-free:
-       free_cpumask_var(mask);
 }
 
 #endif /* CONFIG_SMP */
@@ -979,7 +1002,7 @@ free:
 /*
  * Preempt the current task with a newly woken task if needed:
  */
-static void check_preempt_curr_rt(struct rq *rq, struct task_struct *p, int sync)
+static void check_preempt_curr_rt(struct rq *rq, struct task_struct *p, int flags)
 {
        if (p->prio < rq->curr->prio) {
                resched_task(rq->curr);
@@ -1055,6 +1078,14 @@ static struct task_struct *pick_next_task_rt(struct rq *rq)
        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;
 }
 
@@ -1122,16 +1153,17 @@ static struct task_struct *pick_next_highest_task_rt(struct rq *rq, int cpu)
 
 static DEFINE_PER_CPU(cpumask_var_t, local_cpu_mask);
 
-static inline int pick_optimal_cpu(int this_cpu, cpumask_t *mask)
+static inline int pick_optimal_cpu(int this_cpu,
+                                  const struct cpumask *mask)
 {
        int first;
 
        /* "this_cpu" is cheaper to preempt than a remote processor */
-       if ((this_cpu != -1) && cpu_isset(this_cpu, *mask))
+       if ((this_cpu != -1) && cpumask_test_cpu(this_cpu, mask))
                return this_cpu;
 
-       first = first_cpu(*mask);
-       if (first != NR_CPUS)
+       first = cpumask_first(mask);
+       if (first < nr_cpu_ids)
                return first;
 
        return -1;
@@ -1143,6 +1175,7 @@ static int find_lowest_rq(struct task_struct *task)
        struct cpumask *lowest_mask = __get_cpu_var(local_cpu_mask);
        int this_cpu = smp_processor_id();
        int cpu      = task_cpu(task);
+       cpumask_var_t domain_mask;
 
        if (task->rt.nr_cpus_allowed == 1)
                return -1; /* No other targets possible */
@@ -1151,13 +1184,6 @@ static int find_lowest_rq(struct task_struct *task)
                return -1; /* No targets found */
 
        /*
-        * Only consider CPUs that are usable for migration.
-        * I guess we might want to change cpupri_find() to ignore those
-        * in the first place.
-        */
-       cpumask_and(lowest_mask, lowest_mask, cpu_active_mask);
-
-       /*
         * 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.
@@ -1175,19 +1201,25 @@ static int find_lowest_rq(struct task_struct *task)
        if (this_cpu == cpu)
                this_cpu = -1; /* Skip this_cpu opt if the same */
 
-       for_each_domain(cpu, sd) {
-               if (sd->flags & SD_WAKE_AFFINE) {
-                       cpumask_t domain_mask;
-                       int       best_cpu;
+       if (alloc_cpumask_var(&domain_mask, GFP_ATOMIC)) {
+               for_each_domain(cpu, sd) {
+                       if (sd->flags & SD_WAKE_AFFINE) {
+                               int best_cpu;
+
+                               cpumask_and(domain_mask,
+                                           sched_domain_span(sd),
+                                           lowest_mask);
 
-                       cpumask_and(&domain_mask, sched_domain_span(sd),
-                                   lowest_mask);
+                               best_cpu = pick_optimal_cpu(this_cpu,
+                                                           domain_mask);
 
-                       best_cpu = pick_optimal_cpu(this_cpu,
-                                                   &domain_mask);
-                       if (best_cpu != -1)
-                               return best_cpu;
+                               if (best_cpu != -1) {
+                                       free_cpumask_var(domain_mask);
+                                       return best_cpu;
+                               }
+                       }
                }
+               free_cpumask_var(domain_mask);
        }
 
        /*
@@ -1245,11 +1277,6 @@ static struct rq *find_lock_lowest_rq(struct task_struct *task, struct rq *rq)
        return lowest_rq;
 }
 
-static inline int has_pushable_tasks(struct rq *rq)
-{
-       return !plist_head_empty(&rq->rt.pushable_tasks);
-}
-
 static struct task_struct *pick_next_pushable_task(struct rq *rq)
 {
        struct task_struct *p;
@@ -1449,23 +1476,9 @@ static void pre_schedule_rt(struct rq *rq, struct task_struct *prev)
                pull_rt_task(rq);
 }
 
-/*
- * assumes rq->lock is held
- */
-static int needs_post_schedule_rt(struct rq *rq)
-{
-       return has_pushable_tasks(rq);
-}
-
 static void post_schedule_rt(struct rq *rq)
 {
-       /*
-        * This is only called if needs_post_schedule_rt() indicates that
-        * we need to push tasks away
-        */
-       spin_lock_irq(&rq->lock);
        push_rt_tasks(rq);
-       spin_unlock_irq(&rq->lock);
 }
 
 /*
@@ -1590,7 +1603,7 @@ static inline void init_sched_rt_class(void)
        unsigned int i;
 
        for_each_possible_cpu(i)
-               alloc_cpumask_var_node(&per_cpu(local_cpu_mask, i),
+               zalloc_cpumask_var_node(&per_cpu(local_cpu_mask, i),
                                        GFP_KERNEL, cpu_to_node(i));
 }
 #endif /* CONFIG_SMP */
@@ -1721,6 +1734,17 @@ static void set_curr_task_rt(struct rq *rq)
        dequeue_pushable_task(rq, p);
 }
 
+unsigned int get_rr_interval_rt(struct task_struct *task)
+{
+       /*
+        * Time slice is 0 for SCHED_FIFO tasks
+        */
+       if (task->policy == SCHED_RR)
+               return DEF_TIMESLICE;
+       else
+               return 0;
+}
+
 static const struct sched_class rt_sched_class = {
        .next                   = &fair_sched_class,
        .enqueue_task           = enqueue_task_rt,
@@ -1741,7 +1765,6 @@ static const struct sched_class rt_sched_class = {
        .rq_online              = rq_online_rt,
        .rq_offline             = rq_offline_rt,
        .pre_schedule           = pre_schedule_rt,
-       .needs_post_schedule    = needs_post_schedule_rt,
        .post_schedule          = post_schedule_rt,
        .task_wake_up           = task_wake_up_rt,
        .switched_from          = switched_from_rt,
@@ -1750,6 +1773,8 @@ static const struct sched_class rt_sched_class = {
        .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,
 };