kernel/async.c: fix printk warnings
[safe/jmp/linux-2.6] / kernel / sched_rt.c
index d3d1ccc..bac1061 100644 (file)
@@ -15,7 +15,7 @@ static inline void rt_set_overload(struct rq *rq)
        if (!rq->online)
                return;
 
-       cpu_set(rq->cpu, rq->rd->rto_mask);
+       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
@@ -34,7 +34,7 @@ static inline void rt_clear_overload(struct rq *rq)
 
        /* the order here really doesn't matter */
        atomic_dec(&rq->rd->rto_count);
-       cpu_clear(rq->cpu, rq->rd->rto_mask);
+       cpumask_clear_cpu(rq->cpu, rq->rd->rto_mask);
 }
 
 static void update_rt_migration(struct rq *rq)
@@ -77,7 +77,7 @@ static inline u64 sched_rt_period(struct rt_rq *rt_rq)
 }
 
 #define for_each_leaf_rt_rq(rt_rq, rq) \
-       list_for_each_entry(rt_rq, &rq->leaf_rt_rq_list, leaf_rt_rq_list)
+       list_for_each_entry_rcu(rt_rq, &rq->leaf_rt_rq_list, leaf_rt_rq_list)
 
 static inline struct rq *rq_of_rt_rq(struct rt_rq *rt_rq)
 {
@@ -102,12 +102,12 @@ static void dequeue_rt_entity(struct sched_rt_entity *rt_se);
 
 static void sched_rt_rq_enqueue(struct rt_rq *rt_rq)
 {
+       struct task_struct *curr = rq_of_rt_rq(rt_rq)->curr;
        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->rt_nr_running) {
+               if (rt_se && !on_rt_rq(rt_se))
+                       enqueue_rt_entity(rt_se);
                if (rt_rq->highest_prio < curr->prio)
                        resched_task(curr);
        }
@@ -139,14 +139,14 @@ static int rt_se_boosted(struct sched_rt_entity *rt_se)
 }
 
 #ifdef CONFIG_SMP
-static inline cpumask_t sched_rt_period_mask(void)
+static inline const struct cpumask *sched_rt_period_mask(void)
 {
        return cpu_rq(smp_processor_id())->rd->span;
 }
 #else
-static inline cpumask_t sched_rt_period_mask(void)
+static inline const struct cpumask *sched_rt_period_mask(void)
 {
-       return cpu_online_map;
+       return cpu_online_mask;
 }
 #endif
 
@@ -199,6 +199,8 @@ static inline struct rt_rq *group_rt_rq(struct sched_rt_entity *rt_se)
 
 static inline void sched_rt_rq_enqueue(struct rt_rq *rt_rq)
 {
+       if (rt_rq->rt_nr_running)
+               resched_task(rq_of_rt_rq(rt_rq)->curr);
 }
 
 static inline void sched_rt_rq_dequeue(struct rt_rq *rt_rq)
@@ -210,9 +212,9 @@ static inline int rt_rq_throttled(struct rt_rq *rt_rq)
        return rt_rq->rt_throttled;
 }
 
-static inline cpumask_t sched_rt_period_mask(void)
+static inline const struct cpumask *sched_rt_period_mask(void)
 {
-       return cpu_online_map;
+       return cpu_online_mask;
 }
 
 static inline
@@ -229,6 +231,9 @@ static inline struct rt_bandwidth *sched_rt_bandwidth(struct rt_rq *rt_rq)
 #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);
@@ -236,11 +241,11 @@ static int do_balance_runtime(struct rt_rq *rt_rq)
        int i, weight, more = 0;
        u64 rt_period;
 
-       weight = cpus_weight(rd->span);
+       weight = cpumask_weight(rd->span);
 
        spin_lock(&rt_b->rt_runtime_lock);
        rt_period = ktime_to_ns(rt_b->rt_period);
-       for_each_cpu_mask(i, rd->span) {
+       for_each_cpu(i, rd->span) {
                struct rt_rq *iter = sched_rt_period_rt_rq(rt_b, i);
                s64 diff;
 
@@ -248,12 +253,21 @@ static int do_balance_runtime(struct rt_rq *rt_rq)
                        continue;
 
                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) {
-                       do_div(diff, weight);
+                       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;
@@ -272,6 +286,9 @@ next:
        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;
@@ -287,18 +304,34 @@ static void __disable_runtime(struct rq *rq)
 
                spin_lock(&rt_b->rt_runtime_lock);
                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;
                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;
 
-               for_each_cpu_mask(i, rd->span) {
+               /*
+                * 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;
 
-                       if (iter == rt_rq)
+                       /*
+                        * Can't reclaim from ourselves or disabled runqueues.
+                        */
+                       if (iter == rt_rq || iter->rt_runtime == RUNTIME_INF)
                                continue;
 
                        spin_lock(&iter->rt_runtime_lock);
@@ -317,8 +350,16 @@ static void __disable_runtime(struct rq *rq)
                }
 
                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;
                spin_unlock(&rt_rq->rt_runtime_lock);
                spin_unlock(&rt_b->rt_runtime_lock);
@@ -341,6 +382,9 @@ static void __enable_runtime(struct rq *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);
 
@@ -348,6 +392,7 @@ static void __enable_runtime(struct rq *rq)
                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);
        }
@@ -384,13 +429,13 @@ static inline int balance_runtime(struct rt_rq *rt_rq)
 static int do_sched_rt_period_timer(struct rt_bandwidth *rt_b, int overrun)
 {
        int i, idle = 1;
-       cpumask_t span;
+       const struct cpumask *span;
 
-       if (rt_b->rt_runtime == RUNTIME_INF)
+       if (!rt_bandwidth_enabled() || rt_b->rt_runtime == RUNTIME_INF)
                return 1;
 
        span = sched_rt_period_mask();
-       for_each_cpu_mask(i, span) {
+       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);
@@ -438,9 +483,6 @@ 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);
 
@@ -484,17 +526,24 @@ static void update_curr_rt(struct rq *rq)
        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);
 
+       if (!rt_bandwidth_enabled())
+               return;
+
        for_each_sched_rt_entity(rt_se) {
                rt_rq = rt_rq_of_se(rt_se);
 
-               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);
+               if (sched_rt_runtime(rt_rq) != RUNTIME_INF) {
+                       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);
+               }
        }
 }
 
@@ -505,7 +554,9 @@ void inc_rt_tasks(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq)
        rt_rq->rt_nr_running++;
 #if defined CONFIG_SMP || defined CONFIG_RT_GROUP_SCHED
        if (rt_se_prio(rt_se) < rt_rq->highest_prio) {
+#ifdef CONFIG_SMP
                struct rq *rq = rq_of_rt_rq(rt_rq);
+#endif
 
                rt_rq->highest_prio = rt_se_prio(rt_se);
 #ifdef CONFIG_SMP
@@ -754,17 +805,20 @@ 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_t mask;
+       cpumask_var_t mask;
 
        if (rq->curr->rt.nr_cpus_allowed == 1)
                return;
 
-       if (p->rt.nr_cpus_allowed != 1
-           && cpupri_find(&rq->rd->cpupri, p, &mask))
+       if (!alloc_cpumask_var(&mask, GFP_ATOMIC))
                return;
 
-       if (!cpupri_find(&rq->rd->cpupri, rq->curr, &mask))
-               return;
+       if (p->rt.nr_cpus_allowed != 1
+           && cpupri_find(&rq->rd->cpupri, p, mask))
+               goto free;
+
+       if (!cpupri_find(&rq->rd->cpupri, rq->curr, mask))
+               goto free;
 
        /*
         * There appears to be other cpus that can accept
@@ -773,6 +827,8 @@ 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 */
@@ -780,7 +836,7 @@ 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)
+static void check_preempt_curr_rt(struct rq *rq, struct task_struct *p, int sync)
 {
        if (p->prio < rq->curr->prio) {
                resched_task(rq->curr);
@@ -858,13 +914,12 @@ static void put_prev_task_rt(struct rq *rq, struct task_struct *p)
 /* Only try algorithms three times */
 #define RT_MAX_TRIES 3
 
-static int double_lock_balance(struct rq *this_rq, struct rq *busiest);
 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)
 {
        if (!task_running(rq, p) &&
-           (cpu < 0 || cpu_isset(cpu, p->cpus_allowed)) &&
+           (cpu < 0 || cpumask_test_cpu(cpu, &p->cpus_allowed)) &&
            (p->rt.nr_cpus_allowed > 1))
                return 1;
        return 0;
@@ -903,7 +958,7 @@ static struct task_struct *pick_next_highest_task_rt(struct rq *rq, int cpu)
        return next;
 }
 
-static DEFINE_PER_CPU(cpumask_t, local_cpu_mask);
+static DEFINE_PER_CPU(cpumask_var_t, local_cpu_mask);
 
 static inline int pick_optimal_cpu(int this_cpu, cpumask_t *mask)
 {
@@ -913,8 +968,8 @@ static inline int pick_optimal_cpu(int this_cpu, cpumask_t *mask)
        if ((this_cpu != -1) && cpu_isset(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;
@@ -923,7 +978,7 @@ static inline int pick_optimal_cpu(int this_cpu, cpumask_t *mask)
 static int find_lowest_rq(struct task_struct *task)
 {
        struct sched_domain *sd;
-       cpumask_t *lowest_mask = &__get_cpu_var(local_cpu_mask);
+       struct cpumask *lowest_mask = __get_cpu_var(local_cpu_mask);
        int this_cpu = smp_processor_id();
        int cpu      = task_cpu(task);
 
@@ -934,6 +989,13 @@ 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.
@@ -941,7 +1003,7 @@ static int find_lowest_rq(struct task_struct *task)
         * We prioritize the last cpu that the task executed on since
         * it is most likely cache-hot in that location.
         */
-       if (cpu_isset(cpu, *lowest_mask))
+       if (cpumask_test_cpu(cpu, lowest_mask))
                return cpu;
 
        /*
@@ -956,7 +1018,8 @@ static int find_lowest_rq(struct task_struct *task)
                        cpumask_t domain_mask;
                        int       best_cpu;
 
-                       cpus_and(domain_mask, sd->span, *lowest_mask);
+                       cpumask_and(&domain_mask, sched_domain_span(sd),
+                                   lowest_mask);
 
                        best_cpu = pick_optimal_cpu(this_cpu,
                                                    &domain_mask);
@@ -997,8 +1060,8 @@ static struct rq *find_lock_lowest_rq(struct task_struct *task, struct rq *rq)
                         * Also make sure that it wasn't scheduled on its rq.
                         */
                        if (unlikely(task_rq(task) != rq ||
-                                    !cpu_isset(lowest_rq->cpu,
-                                               task->cpus_allowed) ||
+                                    !cpumask_test_cpu(lowest_rq->cpu,
+                                                      &task->cpus_allowed) ||
                                     task_running(rq, task) ||
                                     !task->se.on_rq)) {
 
@@ -1013,7 +1076,7 @@ static struct rq *find_lock_lowest_rq(struct task_struct *task, struct rq *rq)
                        break;
 
                /* try again */
-               spin_unlock(&lowest_rq->lock);
+               double_unlock_balance(rq, lowest_rq);
                lowest_rq = NULL;
        }
 
@@ -1082,7 +1145,7 @@ static int push_rt_task(struct rq *rq)
 
        resched_task(lowest_rq->curr);
 
-       spin_unlock(&lowest_rq->lock);
+       double_unlock_balance(rq, lowest_rq);
 
        ret = 1;
 out:
@@ -1119,7 +1182,7 @@ static int pull_rt_task(struct rq *this_rq)
 
        next = pick_next_task_rt(this_rq);
 
-       for_each_cpu_mask(cpu, this_rq->rd->rto_mask) {
+       for_each_cpu(cpu, this_rq->rd->rto_mask) {
                if (this_cpu == cpu)
                        continue;
 
@@ -1188,7 +1251,7 @@ static int pull_rt_task(struct rq *this_rq)
 
                }
  skip:
-               spin_unlock(&src_rq->lock);
+               double_unlock_balance(this_rq, src_rq);
        }
 
        return ret;
@@ -1248,9 +1311,9 @@ move_one_task_rt(struct rq *this_rq, int this_cpu, struct rq *busiest,
 }
 
 static void set_cpus_allowed_rt(struct task_struct *p,
-                               const cpumask_t *new_mask)
+                               const struct cpumask *new_mask)
 {
-       int weight = cpus_weight(*new_mask);
+       int weight = cpumask_weight(new_mask);
 
        BUG_ON(!rt_task(p));
 
@@ -1271,7 +1334,7 @@ static void set_cpus_allowed_rt(struct task_struct *p,
                update_rt_migration(rq);
        }
 
-       p->cpus_allowed    = *new_mask;
+       cpumask_copy(&p->cpus_allowed, new_mask);
        p->rt.nr_cpus_allowed = weight;
 }
 
@@ -1314,6 +1377,15 @@ static void switched_from_rt(struct rq *rq, struct task_struct *p,
        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)
+               alloc_cpumask_var_node(&per_cpu(local_cpu_mask, i),
+                                       GFP_KERNEL, cpu_to_node(i));
+}
 #endif /* CONFIG_SMP */
 
 /*
@@ -1400,7 +1472,7 @@ static void watchdog(struct rq *rq, struct task_struct *p)
                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;
+                       p->cputime_expires.sched_exp = p->se.sum_exec_runtime;
        }
 }
 
@@ -1444,9 +1516,6 @@ static const struct sched_class rt_sched_class = {
        .enqueue_task           = enqueue_task_rt,
        .dequeue_task           = dequeue_task_rt,
        .yield_task             = yield_task_rt,
-#ifdef CONFIG_SMP
-       .select_task_rq         = select_task_rq_rt,
-#endif /* CONFIG_SMP */
 
        .check_preempt_curr     = check_preempt_curr_rt,
 
@@ -1454,6 +1523,8 @@ static const struct sched_class rt_sched_class = {
        .put_prev_task          = put_prev_task_rt,
 
 #ifdef CONFIG_SMP
+       .select_task_rq         = select_task_rq_rt,
+
        .load_balance           = load_balance_rt,
        .move_one_task          = move_one_task_rt,
        .set_cpus_allowed       = set_cpus_allowed_rt,
@@ -1485,3 +1556,4 @@ static void print_rt_stats(struct seq_file *m, int cpu)
        rcu_read_unlock();
 }
 #endif /* CONFIG_SCHED_DEBUG */
+