1 files changed, 121 insertions, 96 deletions

diff --git a/kernel/sched.c b/kernel/sched.c
index 927c9307cd00..669c49aa57f0 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -204,11 +204,16 @@ void init_rt_bandwidth(struct rt_bandwidth *rt_b, u64 period, u64 runtime)
 	rt_b->rt_period_timer.cb_mode = HRTIMER_CB_IRQSAFE_NO_SOFTIRQ;
 }
 
+static inline int rt_bandwidth_enabled(void)
+{
+	return sysctl_sched_rt_runtime >= 0;
+}
+
 static void start_rt_bandwidth(struct rt_bandwidth *rt_b)
 {
 	ktime_t now;
 
-	if (rt_b->rt_runtime == RUNTIME_INF)
+	if (rt_bandwidth_enabled() && rt_b->rt_runtime == RUNTIME_INF)
 		return;
 
 	if (hrtimer_active(&rt_b->rt_period_timer))
@@ -298,9 +303,9 @@ static DEFINE_PER_CPU(struct cfs_rq, init_cfs_rq) ____cacheline_aligned_in_smp;
 static DEFINE_PER_CPU(struct sched_rt_entity, init_sched_rt_entity);
 static DEFINE_PER_CPU(struct rt_rq, init_rt_rq) ____cacheline_aligned_in_smp;
 #endif /* CONFIG_RT_GROUP_SCHED */
-#else /* !CONFIG_FAIR_GROUP_SCHED */
+#else /* !CONFIG_USER_SCHED */
 #define root_task_group init_task_group
-#endif /* CONFIG_FAIR_GROUP_SCHED */
+#endif /* CONFIG_USER_SCHED */
 
 /* task_group_lock serializes add/remove of task groups and also changes to
  * a task group's cpu shares.
@@ -1087,7 +1092,7 @@ hotplug_hrtick(struct notifier_block *nfb, unsigned long action, void *hcpu)
 	return NOTIFY_DONE;
 }
 
-static void init_hrtick(void)
+static __init void init_hrtick(void)
 {
 	hotcpu_notifier(hotplug_hrtick, 0);
 }
@@ -1380,38 +1385,24 @@ static inline void dec_cpu_load(struct rq *rq, unsigned long load)
 	update_load_sub(&rq->load, load);
 }
 
-#ifdef CONFIG_SMP
-static unsigned long source_load(int cpu, int type);
-static unsigned long target_load(int cpu, int type);
-static int task_hot(struct task_struct *p, u64 now, struct sched_domain *sd);
-
-static unsigned long cpu_avg_load_per_task(int cpu)
-{
-	struct rq *rq = cpu_rq(cpu);
-
-	if (rq->nr_running)
-		rq->avg_load_per_task = rq->load.weight / rq->nr_running;
-
-	return rq->avg_load_per_task;
-}
-
-#ifdef CONFIG_FAIR_GROUP_SCHED
-
-typedef void (*tg_visitor)(struct task_group *, int, struct sched_domain *);
+#if (defined(CONFIG_SMP) && defined(CONFIG_FAIR_GROUP_SCHED)) || defined(CONFIG_RT_GROUP_SCHED)
+typedef int (*tg_visitor)(struct task_group *, void *);
 
 /*
  * Iterate the full tree, calling @down when first entering a node and @up when
  * leaving it for the final time.
  */
-static void
-walk_tg_tree(tg_visitor down, tg_visitor up, int cpu, struct sched_domain *sd)
+static int walk_tg_tree(tg_visitor down, tg_visitor up, void *data)
 {
 	struct task_group *parent, *child;
+	int ret;
 
 	rcu_read_lock();
 	parent = &root_task_group;
 down:
-	(*down)(parent, cpu, sd);
+	ret = (*down)(parent, data);
+	if (ret)
+		goto out_unlock;
 	list_for_each_entry_rcu(child, &parent->children, siblings) {
 		parent = child;
 		goto down;
@@ -1419,15 +1410,43 @@ down:
 up:
 		continue;
 	}
-	(*up)(parent, cpu, sd);
+	ret = (*up)(parent, data);
+	if (ret)
+		goto out_unlock;
 
 	child = parent;
 	parent = parent->parent;
 	if (parent)
 		goto up;
+out_unlock:
 	rcu_read_unlock();
+
+	return ret;
 }
 
+static int tg_nop(struct task_group *tg, void *data)
+{
+	return 0;
+}
+#endif
+
+#ifdef CONFIG_SMP
+static unsigned long source_load(int cpu, int type);
+static unsigned long target_load(int cpu, int type);
+static int task_hot(struct task_struct *p, u64 now, struct sched_domain *sd);
+
+static unsigned long cpu_avg_load_per_task(int cpu)
+{
+	struct rq *rq = cpu_rq(cpu);
+
+	if (rq->nr_running)
+		rq->avg_load_per_task = rq->load.weight / rq->nr_running;
+
+	return rq->avg_load_per_task;
+}
+
+#ifdef CONFIG_FAIR_GROUP_SCHED
+
 static void __set_se_shares(struct sched_entity *se, unsigned long shares);
 
 /*
@@ -1486,11 +1505,11 @@ __update_group_shares_cpu(struct task_group *tg, int cpu,
  * This needs to be done in a bottom-up fashion because the rq weight of a
  * parent group depends on the shares of its child groups.
  */
-static void
-tg_shares_up(struct task_group *tg, int cpu, struct sched_domain *sd)
+static int tg_shares_up(struct task_group *tg, void *data)
 {
 	unsigned long rq_weight = 0;
 	unsigned long shares = 0;
+	struct sched_domain *sd = data;
 	int i;
 
 	for_each_cpu_mask(i, sd->span) {
@@ -1515,6 +1534,8 @@ tg_shares_up(struct task_group *tg, int cpu, struct sched_domain *sd)
 		__update_group_shares_cpu(tg, i, shares, rq_weight);
 		spin_unlock_irqrestore(&rq->lock, flags);
 	}
+
+	return 0;
 }
 
 /*
@@ -1522,10 +1543,10 @@ tg_shares_up(struct task_group *tg, int cpu, struct sched_domain *sd)
  * This needs to be done in a top-down fashion because the load of a child
  * group is a fraction of its parents load.
  */
-static void
-tg_load_down(struct task_group *tg, int cpu, struct sched_domain *sd)
+static int tg_load_down(struct task_group *tg, void *data)
 {
 	unsigned long load;
+	long cpu = (long)data;
 
 	if (!tg->parent) {
 		load = cpu_rq(cpu)->load.weight;
@@ -1536,11 +1557,8 @@ tg_load_down(struct task_group *tg, int cpu, struct sched_domain *sd)
 	}
 
 	tg->cfs_rq[cpu]->h_load = load;
-}
 
-static void
-tg_nop(struct task_group *tg, int cpu, struct sched_domain *sd)
-{
+	return 0;
 }
 
 static void update_shares(struct sched_domain *sd)
@@ -1550,7 +1568,7 @@ static void update_shares(struct sched_domain *sd)
 
 	if (elapsed >= (s64)(u64)sysctl_sched_shares_ratelimit) {
 		sd->last_update = now;
-		walk_tg_tree(tg_nop, tg_shares_up, 0, sd);
+		walk_tg_tree(tg_nop, tg_shares_up, sd);
 	}
 }
 
@@ -1561,9 +1579,9 @@ static void update_shares_locked(struct rq *rq, struct sched_domain *sd)
 	spin_lock(&rq->lock);
 }
 
-static void update_h_load(int cpu)
+static void update_h_load(long cpu)
 {
-	walk_tg_tree(tg_load_down, tg_nop, cpu, NULL);
+	walk_tg_tree(tg_load_down, tg_nop, (void *)cpu);
 }
 
 #else
@@ -5171,7 +5189,8 @@ recheck:
 		 * Do not allow realtime tasks into groups that have no runtime
 		 * assigned.
 		 */
-		if (rt_policy(policy) && task_group(p)->rt_bandwidth.rt_runtime == 0)
+		if (rt_bandwidth_enabled() && rt_policy(policy) &&
+				task_group(p)->rt_bandwidth.rt_runtime == 0)
 			return -EPERM;
 #endif
 
@@ -8808,73 +8827,77 @@ static DEFINE_MUTEX(rt_constraints_mutex);
 static unsigned long to_ratio(u64 period, u64 runtime)
 {
 	if (runtime == RUNTIME_INF)
-		return 1ULL << 16;
+		return 1ULL << 20;
 
-	return div64_u64(runtime << 16, period);
+	return div64_u64(runtime << 20, period);
 }
 
-#ifdef CONFIG_CGROUP_SCHED
-static int __rt_schedulable(struct task_group *tg, u64 period, u64 runtime)
+/* Must be called with tasklist_lock held */
+static inline int tg_has_rt_tasks(struct task_group *tg)
 {
-	struct task_group *tgi, *parent = tg->parent;
-	unsigned long total = 0;
+	struct task_struct *g, *p;
 
-	if (!parent) {
-		if (global_rt_period() < period)
-			return 0;
+	do_each_thread(g, p) {
+		if (rt_task(p) && rt_rq_of_se(&p->rt)->tg == tg)
+			return 1;
+	} while_each_thread(g, p);
 
-		return to_ratio(period, runtime) <
-			to_ratio(global_rt_period(), global_rt_runtime());
-	}
+	return 0;
+}
 
-	if (ktime_to_ns(parent->rt_bandwidth.rt_period) < period)
-		return 0;
+struct rt_schedulable_data {
+	struct task_group *tg;
+	u64 rt_period;
+	u64 rt_runtime;
+};
 
-	rcu_read_lock();
-	list_for_each_entry_rcu(tgi, &parent->children, siblings) {
-		if (tgi == tg)
-			continue;
+static int tg_schedulable(struct task_group *tg, void *data)
+{
+	struct rt_schedulable_data *d = data;
+	struct task_group *child;
+	unsigned long total, sum = 0;
+	u64 period, runtime;
 
-		total += to_ratio(ktime_to_ns(tgi->rt_bandwidth.rt_period),
-				tgi->rt_bandwidth.rt_runtime);
+	period = ktime_to_ns(tg->rt_bandwidth.rt_period);
+	runtime = tg->rt_bandwidth.rt_runtime;
+
+	if (tg == d->tg) {
+		period = d->rt_period;
+		runtime = d->rt_runtime;
 	}
-	rcu_read_unlock();
 
-	return total + to_ratio(period, runtime) <=
-		to_ratio(ktime_to_ns(parent->rt_bandwidth.rt_period),
-				parent->rt_bandwidth.rt_runtime);
-}
-#elif defined CONFIG_USER_SCHED
-static int __rt_schedulable(struct task_group *tg, u64 period, u64 runtime)
-{
-	struct task_group *tgi;
-	unsigned long total = 0;
-	unsigned long global_ratio =
-		to_ratio(global_rt_period(), global_rt_runtime());
+	if (rt_bandwidth_enabled() && !runtime && tg_has_rt_tasks(tg))
+		return -EBUSY;
 
-	rcu_read_lock();
-	list_for_each_entry_rcu(tgi, &task_groups, list) {
-		if (tgi == tg)
-			continue;
+	total = to_ratio(period, runtime);
+
+	list_for_each_entry_rcu(child, &tg->children, siblings) {
+		period = ktime_to_ns(child->rt_bandwidth.rt_period);
+		runtime = child->rt_bandwidth.rt_runtime;
 
-		total += to_ratio(ktime_to_ns(tgi->rt_bandwidth.rt_period),
-				tgi->rt_bandwidth.rt_runtime);
+		if (child == d->tg) {
+			period = d->rt_period;
+			runtime = d->rt_runtime;
+		}
+
+		sum += to_ratio(period, runtime);
 	}
-	rcu_read_unlock();
 
-	return total + to_ratio(period, runtime) < global_ratio;
+	if (sum > total)
+		return -EINVAL;
+
+	return 0;
 }
-#endif
 
-/* Must be called with tasklist_lock held */
-static inline int tg_has_rt_tasks(struct task_group *tg)
+static int __rt_schedulable(struct task_group *tg, u64 period, u64 runtime)
 {
-	struct task_struct *g, *p;
-	do_each_thread(g, p) {
-		if (rt_task(p) && rt_rq_of_se(&p->rt)->tg == tg)
-			return 1;
-	} while_each_thread(g, p);
-	return 0;
+	struct rt_schedulable_data data = {
+		.tg = tg,
+		.rt_period = period,
+		.rt_runtime = runtime,
+	};
+
+	return walk_tg_tree(tg_schedulable, tg_nop, &data);
 }
 
 static int tg_set_bandwidth(struct task_group *tg,
@@ -8884,14 +8907,9 @@ static int tg_set_bandwidth(struct task_group *tg,
 
 	mutex_lock(&rt_constraints_mutex);
 	read_lock(&tasklist_lock);
-	if (rt_runtime == 0 && tg_has_rt_tasks(tg)) {
-		err = -EBUSY;
+	err = __rt_schedulable(tg, rt_period, rt_runtime);
+	if (err)
 		goto unlock;
-	}
-	if (!__rt_schedulable(tg, rt_period, rt_runtime)) {
-		err = -EINVAL;
-		goto unlock;
-	}
 
 	spin_lock_irq(&tg->rt_bandwidth.rt_runtime_lock);
 	tg->rt_bandwidth.rt_period = ns_to_ktime(rt_period);
@@ -8964,12 +8982,16 @@ static int sched_rt_global_constraints(void)
 	u64 rt_runtime, rt_period;
 	int ret = 0;
 
+	if (sysctl_sched_rt_period <= 0)
+		return -EINVAL;
+
 	rt_period = ktime_to_ns(tg->rt_bandwidth.rt_period);
 	rt_runtime = tg->rt_bandwidth.rt_runtime;
 
 	mutex_lock(&rt_constraints_mutex);
-	if (!__rt_schedulable(tg, rt_period, rt_runtime))
-		ret = -EINVAL;
+	read_lock(&tasklist_lock);
+	ret = __rt_schedulable(tg, rt_period, rt_runtime);
+	read_unlock(&tasklist_lock);
 	mutex_unlock(&rt_constraints_mutex);
 
 	return ret;
@@ -8980,6 +9002,9 @@ static int sched_rt_global_constraints(void)
 	unsigned long flags;
 	int i;
 
+	if (sysctl_sched_rt_period <= 0)
+		return -EINVAL;
+
 	spin_lock_irqsave(&def_rt_bandwidth.rt_runtime_lock, flags);
 	for_each_possible_cpu(i) {
 		struct rt_rq *rt_rq = &cpu_rq(i)->rt;