rcu: Make rcu_read_lock_sched_held() take boot time into account
[linux-2.6.git] / kernel / sched_rt.c
index a8f89bc..f48328a 100644 (file)
@@ -3,15 +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
-
-#define rt_entity_is_task(rt_se) (!(rt_se)->my_q)
-
 static inline struct rq *rq_of_rt_rq(struct rt_rq *rt_rq)
 {
        return rt_rq->rq;
@@ -26,6 +29,11 @@ static inline struct rt_rq *rt_rq_of_se(struct sched_rt_entity *rt_se)
 
 #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);
@@ -128,6 +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)
@@ -314,7 +327,7 @@ static int do_balance_runtime(struct rt_rq *rt_rq)
 
        weight = cpumask_weight(rd->span);
 
-       spin_lock(&rt_b->rt_runtime_lock);
+       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);
@@ -323,7 +336,7 @@ static int do_balance_runtime(struct rt_rq *rt_rq)
                if (iter == rt_rq)
                        continue;
 
-               spin_lock(&iter->rt_runtime_lock);
+               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
@@ -345,14 +358,14 @@ static int do_balance_runtime(struct rt_rq *rt_rq)
                        rt_rq->rt_runtime += diff;
                        more = 1;
                        if (rt_rq->rt_runtime == rt_period) {
-                               spin_unlock(&iter->rt_runtime_lock);
+                               raw_spin_unlock(&iter->rt_runtime_lock);
                                break;
                        }
                }
 next:
-               spin_unlock(&iter->rt_runtime_lock);
+               raw_spin_unlock(&iter->rt_runtime_lock);
        }
-       spin_unlock(&rt_b->rt_runtime_lock);
+       raw_spin_unlock(&rt_b->rt_runtime_lock);
 
        return more;
 }
@@ -373,8 +386,8 @@ static void __disable_runtime(struct rq *rq)
                s64 want;
                int i;
 
-               spin_lock(&rt_b->rt_runtime_lock);
-               spin_lock(&rt_rq->rt_runtime_lock);
+               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
@@ -383,7 +396,7 @@ static void __disable_runtime(struct rq *rq)
                if (rt_rq->rt_runtime == RUNTIME_INF ||
                                rt_rq->rt_runtime == rt_b->rt_runtime)
                        goto balanced;
-               spin_unlock(&rt_rq->rt_runtime_lock);
+               raw_spin_unlock(&rt_rq->rt_runtime_lock);
 
                /*
                 * Calculate the difference between what we started out with
@@ -405,7 +418,7 @@ static void __disable_runtime(struct rq *rq)
                        if (iter == rt_rq || iter->rt_runtime == RUNTIME_INF)
                                continue;
 
-                       spin_lock(&iter->rt_runtime_lock);
+                       raw_spin_lock(&iter->rt_runtime_lock);
                        if (want > 0) {
                                diff = min_t(s64, iter->rt_runtime, want);
                                iter->rt_runtime -= diff;
@@ -414,13 +427,13 @@ static void __disable_runtime(struct rq *rq)
                                iter->rt_runtime -= want;
                                want -= want;
                        }
-                       spin_unlock(&iter->rt_runtime_lock);
+                       raw_spin_unlock(&iter->rt_runtime_lock);
 
                        if (!want)
                                break;
                }
 
-               spin_lock(&rt_rq->rt_runtime_lock);
+               raw_spin_lock(&rt_rq->rt_runtime_lock);
                /*
                 * We cannot be left wanting - that would mean some runtime
                 * leaked out of the system.
@@ -432,8 +445,8 @@ balanced:
                 * runtime - in which case borrowing doesn't make sense.
                 */
                rt_rq->rt_runtime = RUNTIME_INF;
-               spin_unlock(&rt_rq->rt_runtime_lock);
-               spin_unlock(&rt_b->rt_runtime_lock);
+               raw_spin_unlock(&rt_rq->rt_runtime_lock);
+               raw_spin_unlock(&rt_b->rt_runtime_lock);
        }
 }
 
@@ -441,9 +454,9 @@ static void disable_runtime(struct rq *rq)
 {
        unsigned long flags;
 
-       spin_lock_irqsave(&rq->lock, flags);
+       raw_spin_lock_irqsave(&rq->lock, flags);
        __disable_runtime(rq);
-       spin_unlock_irqrestore(&rq->lock, flags);
+       raw_spin_unlock_irqrestore(&rq->lock, flags);
 }
 
 static void __enable_runtime(struct rq *rq)
@@ -459,13 +472,13 @@ static void __enable_runtime(struct rq *rq)
        for_each_leaf_rt_rq(rt_rq, rq) {
                struct rt_bandwidth *rt_b = sched_rt_bandwidth(rt_rq);
 
-               spin_lock(&rt_b->rt_runtime_lock);
-               spin_lock(&rt_rq->rt_runtime_lock);
+               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;
-               spin_unlock(&rt_rq->rt_runtime_lock);
-               spin_unlock(&rt_b->rt_runtime_lock);
+               raw_spin_unlock(&rt_rq->rt_runtime_lock);
+               raw_spin_unlock(&rt_b->rt_runtime_lock);
        }
 }
 
@@ -473,9 +486,9 @@ static void enable_runtime(struct rq *rq)
 {
        unsigned long flags;
 
-       spin_lock_irqsave(&rq->lock, flags);
+       raw_spin_lock_irqsave(&rq->lock, flags);
        __enable_runtime(rq);
-       spin_unlock_irqrestore(&rq->lock, flags);
+       raw_spin_unlock_irqrestore(&rq->lock, flags);
 }
 
 static int balance_runtime(struct rt_rq *rt_rq)
@@ -483,9 +496,9 @@ static int balance_runtime(struct rt_rq *rt_rq)
        int more = 0;
 
        if (rt_rq->rt_time > rt_rq->rt_runtime) {
-               spin_unlock(&rt_rq->rt_runtime_lock);
+               raw_spin_unlock(&rt_rq->rt_runtime_lock);
                more = do_balance_runtime(rt_rq);
-               spin_lock(&rt_rq->rt_runtime_lock);
+               raw_spin_lock(&rt_rq->rt_runtime_lock);
        }
 
        return more;
@@ -511,11 +524,11 @@ static int do_sched_rt_period_timer(struct rt_bandwidth *rt_b, int overrun)
                struct rt_rq *rt_rq = sched_rt_period_rt_rq(rt_b, i);
                struct rq *rq = rq_of_rt_rq(rt_rq);
 
-               spin_lock(&rq->lock);
+               raw_spin_lock(&rq->lock);
                if (rt_rq->rt_time) {
                        u64 runtime;
 
-                       spin_lock(&rt_rq->rt_runtime_lock);
+                       raw_spin_lock(&rt_rq->rt_runtime_lock);
                        if (rt_rq->rt_throttled)
                                balance_runtime(rt_rq);
                        runtime = rt_rq->rt_runtime;
@@ -526,13 +539,13 @@ static int do_sched_rt_period_timer(struct rt_bandwidth *rt_b, int overrun)
                        }
                        if (rt_rq->rt_time || rt_rq->rt_nr_running)
                                idle = 0;
-                       spin_unlock(&rt_rq->rt_runtime_lock);
+                       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);
-               spin_unlock(&rq->lock);
+               raw_spin_unlock(&rq->lock);
        }
 
        return idle;
@@ -602,6 +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;
 
@@ -609,11 +624,11 @@ static void update_curr_rt(struct rq *rq)
                rt_rq = rt_rq_of_se(rt_se);
 
                if (sched_rt_runtime(rt_rq) != RUNTIME_INF) {
-                       spin_lock(&rt_rq->rt_runtime_lock);
+                       raw_spin_lock(&rt_rq->rt_runtime_lock);
                        rt_rq->rt_time += delta_exec;
                        if (sched_rt_runtime_exceeded(rt_rq))
                                resched_task(curr);
-                       spin_unlock(&rt_rq->rt_runtime_lock);
+                       raw_spin_unlock(&rt_rq->rt_runtime_lock);
                }
        }
 }
@@ -874,8 +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)
@@ -886,8 +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);
 }
 
 /*
@@ -927,10 +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
@@ -988,7 +1002,7 @@ static void check_preempt_equal_prio(struct rq *rq, struct task_struct *p)
 /*
  * 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);
@@ -1056,11 +1070,6 @@ static struct task_struct *_pick_next_task_rt(struct rq *rq)
        return p;
 }
 
-static inline int has_pushable_tasks(struct rq *rq)
-{
-       return !plist_head_empty(&rq->rt.pushable_tasks);
-}
-
 static struct task_struct *pick_next_task_rt(struct rq *rq)
 {
        struct task_struct *p = _pick_next_task_rt(rq);
@@ -1069,11 +1078,13 @@ 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;
 }
@@ -1142,29 +1153,12 @@ 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,
-                                  const struct cpumask *mask)
-{
-       int first;
-
-       /* "this_cpu" is cheaper to preempt than a remote processor */
-       if ((this_cpu != -1) && cpumask_test_cpu(this_cpu, mask))
-               return this_cpu;
-
-       first = cpumask_first(mask);
-       if (first < nr_cpu_ids)
-               return first;
-
-       return -1;
-}
-
 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);
-       cpumask_var_t domain_mask;
 
        if (task->rt.nr_cpus_allowed == 1)
                return -1; /* No other targets possible */
@@ -1173,13 +1167,6 @@ 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.
@@ -1194,28 +1181,26 @@ static int find_lowest_rq(struct task_struct *task)
         * Otherwise, we consult the sched_domains span maps to figure
         * out which cpu is logically closest to our hot cache data.
         */
-       if (this_cpu == cpu)
-               this_cpu = -1; /* Skip this_cpu opt if the same */
+       if (!cpumask_test_cpu(this_cpu, lowest_mask))
+               this_cpu = -1; /* Skip this_cpu opt if not among lowest */
 
-       if (alloc_cpumask_var(&domain_mask, GFP_ATOMIC)) {
-               for_each_domain(cpu, sd) {
-                       if (sd->flags & SD_WAKE_AFFINE) {
-                               int best_cpu;
+       for_each_domain(cpu, sd) {
+               if (sd->flags & SD_WAKE_AFFINE) {
+                       int best_cpu;
 
-                               cpumask_and(domain_mask,
-                                           sched_domain_span(sd),
-                                           lowest_mask);
-
-                               best_cpu = pick_optimal_cpu(this_cpu,
-                                                           domain_mask);
-
-                               if (best_cpu != -1) {
-                                       free_cpumask_var(domain_mask);
-                                       return 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;
                }
-               free_cpumask_var(domain_mask);
        }
 
        /*
@@ -1223,7 +1208,13 @@ static int find_lowest_rq(struct task_struct *task)
         * just give the caller *something* to work with from the compatible
         * locations.
         */
-       return pick_optimal_cpu(this_cpu, lowest_mask);
+       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 */
@@ -1255,7 +1246,7 @@ static struct rq *find_lock_lowest_rq(struct task_struct *task, struct rq *rq)
                                     task_running(rq, task) ||
                                     !task->se.on_rq)) {
 
-                               spin_unlock(&lowest_rq->lock);
+                               raw_spin_unlock(&lowest_rq->lock);
                                lowest_rq = NULL;
                                break;
                        }
@@ -1481,7 +1472,7 @@ static void post_schedule_rt(struct rq *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_wake_up_rt(struct rq *rq, struct task_struct *p)
+static void task_woken_rt(struct rq *rq, struct task_struct *p)
 {
        if (!task_running(rq, p) &&
            !test_tsk_need_resched(rq->curr) &&
@@ -1730,6 +1721,17 @@ static void set_curr_task_rt(struct rq *rq)
        dequeue_pushable_task(rq, p);
 }
 
+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;
+}
+
 static const struct sched_class rt_sched_class = {
        .next                   = &fair_sched_class,
        .enqueue_task           = enqueue_task_rt,
@@ -1751,13 +1753,15 @@ static const struct sched_class rt_sched_class = {
        .rq_offline             = rq_offline_rt,
        .pre_schedule           = pre_schedule_rt,
        .post_schedule          = post_schedule_rt,
-       .task_wake_up           = task_wake_up_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,
 };