Merge branch 'sched/latest' of... (0a6d4e1d) · Commits · git / linux-net

include/linux/init_task.h

+1 −0

Original line number	Diff line number	Diff line
		@@ -142,6 +142,7 @@ extern struct cred init_cred;
		.nr_cpus_allowed = NR_CPUS, \
		}, \
		.tasks = LIST_HEAD_INIT(tsk.tasks), \
		.pushable_tasks = PLIST_NODE_INIT(tsk.pushable_tasks, MAX_PRIO), \
		.ptraced = LIST_HEAD_INIT(tsk.ptraced), \
		.ptrace_entry = LIST_HEAD_INIT(tsk.ptrace_entry), \
		.real_parent = &tsk, \

include/linux/plist.h

+6 −3

Original line number	Diff line number	Diff line
		@@ -96,6 +96,10 @@ struct plist_node {
		# define PLIST_HEAD_LOCK_INIT(_lock)
		#endif

		#define _PLIST_HEAD_INIT(head) \
		.prio_list = LIST_HEAD_INIT((head).prio_list), \
		.node_list = LIST_HEAD_INIT((head).node_list)

		/**
		* PLIST_HEAD_INIT - static struct plist_head initializer
		* @head: struct plist_head variable name
		@@ -103,8 +107,7 @@ struct plist_node {
		*/
		#define PLIST_HEAD_INIT(head, _lock) \
		{ \
		.prio_list = LIST_HEAD_INIT((head).prio_list), \
		.node_list = LIST_HEAD_INIT((head).node_list), \
		_PLIST_HEAD_INIT(head), \
		PLIST_HEAD_LOCK_INIT(&(_lock)) \
		}

		@@ -116,7 +119,7 @@ struct plist_node {
		#define PLIST_NODE_INIT(node, __prio) \
		{ \
		.prio = (__prio), \
		.plist = PLIST_HEAD_INIT((node).plist, NULL), \
		.plist = { _PLIST_HEAD_INIT((node).plist) }, \
		}

		/**

include/linux/sched.h

+2 −0

Original line number	Diff line number	Diff line
		@@ -977,6 +977,7 @@ struct sched_class {
		struct rq busiest, struct sched_domain sd,
		enum cpu_idle_type idle);
		void (pre_schedule) (struct rq this_rq, struct task_struct *task);
		int (needs_post_schedule) (struct rq this_rq);
		void (post_schedule) (struct rq this_rq);
		void (task_wake_up) (struct rq this_rq, struct task_struct *task);

		@@ -1143,6 +1144,7 @@ struct task_struct {
		#endif

		struct list_head tasks;
		struct plist_node pushable_tasks;

		struct mm_struct mm, active_mm;

kernel/sched.c

+78 −11

Original line number	Diff line number	Diff line
		@@ -464,11 +464,15 @@ struct rt_rq {
		struct rt_prio_array active;
		unsigned long rt_nr_running;
		#if defined CONFIG_SMP \|\| defined CONFIG_RT_GROUP_SCHED
		int highest_prio; /* highest queued rt task prio */
		struct {
		int curr; /* highest queued rt task prio */
		int next; /* next highest */
		} highest_prio;
		#endif
		#ifdef CONFIG_SMP
		unsigned long rt_nr_migratory;
		int overloaded;
		struct plist_head pushable_tasks;
		#endif
		int rt_throttled;
		u64 rt_time;
		@@ -1607,21 +1611,42 @@ static inline void update_shares_locked(struct rq rq, struct sched_domain sd)

		#endif

		#ifdef CONFIG_PREEMPT

		/*
		* double_lock_balance - lock the busiest runqueue, this_rq is locked already.
		* fair double_lock_balance: Safely acquires both rq->locks in a fair
		* way at the expense of forcing extra atomic operations in all
		* invocations. This assures that the double_lock is acquired using the
		* same underlying policy as the spinlock_t on this architecture, which
		* reduces latency compared to the unfair variant below. However, it
		* also adds more overhead and therefore may reduce throughput.
		*/
		static int double_lock_balance(struct rq this_rq, struct rq busiest)
		static inline int _double_lock_balance(struct rq this_rq, struct rq busiest)
		__releases(this_rq->lock)
		__acquires(busiest->lock)
		__acquires(this_rq->lock)
		{
		int ret = 0;

		if (unlikely(!irqs_disabled())) {
		/* printk() doesn't work good under rq->lock */
		spin_unlock(&this_rq->lock);
		BUG_ON(1);
		double_rq_lock(this_rq, busiest);

		return 1;
		}

		#else
		/*
		* Unfair double_lock_balance: Optimizes throughput at the expense of
		* latency by eliminating extra atomic operations when the locks are
		* already in proper order on entry. This favors lower cpu-ids and will
		* grant the double lock to lower cpus over higher ids under contention,
		* regardless of entry order into the function.
		*/
		static int _double_lock_balance(struct rq this_rq, struct rq busiest)
		__releases(this_rq->lock)
		__acquires(busiest->lock)
		__acquires(this_rq->lock)
		{
		int ret = 0;

		if (unlikely(!spin_trylock(&busiest->lock))) {
		if (busiest < this_rq) {
		spin_unlock(&this_rq->lock);
		@@ -1634,6 +1659,22 @@ static int double_lock_balance(struct rq this_rq, struct rq busiest)
		return ret;
		}

		#endif /* CONFIG_PREEMPT */

		/*
		* double_lock_balance - lock the busiest runqueue, this_rq is locked already.
		*/
		static int double_lock_balance(struct rq this_rq, struct rq busiest)
		{
		if (unlikely(!irqs_disabled())) {
		/* printk() doesn't work good under rq->lock */
		spin_unlock(&this_rq->lock);
		BUG_ON(1);
		}

		return _double_lock_balance(this_rq, busiest);
		}

		static inline void double_unlock_balance(struct rq this_rq, struct rq busiest)
		__releases(busiest->lock)
		{
		@@ -2445,6 +2486,8 @@ void sched_fork(struct task_struct *p, int clone_flags)
		/* Want to start with kernel preemption disabled. */
		task_thread_info(p)->preempt_count = 1;
		#endif
		plist_node_init(&p->pushable_tasks, MAX_PRIO);

		put_cpu();
		}

		@@ -2585,6 +2628,12 @@ static void finish_task_switch(struct rq rq, struct task_struct prev)
		{
		struct mm_struct *mm = rq->prev_mm;
		long prev_state;
		#ifdef CONFIG_SMP
		int post_schedule = 0;

		if (current->sched_class->needs_post_schedule)
		post_schedule = current->sched_class->needs_post_schedule(rq);
		#endif

		rq->prev_mm = NULL;

		@@ -2603,7 +2652,7 @@ static void finish_task_switch(struct rq rq, struct task_struct prev)
		finish_arch_switch(prev);
		finish_lock_switch(rq, prev);
		#ifdef CONFIG_SMP
		if (current->sched_class->post_schedule)
		if (post_schedule)
		current->sched_class->post_schedule(rq);
		#endif

		@@ -2984,6 +3033,16 @@ balance_tasks(struct rq this_rq, int this_cpu, struct rq busiest,
		pulled++;
		rem_load_move -= p->se.load.weight;

		#ifdef CONFIG_PREEMPT
		/*
		* NEWIDLE balancing is a source of latency, so preemptible kernels
		* will stop after the first task is pulled to minimize the critical
		* section.
		*/
		if (idle == CPU_NEWLY_IDLE)
		goto out;
		#endif

		/*
		* We only want to steal up to the prescribed amount of weighted load.
		*/
		@@ -3030,9 +3089,15 @@ static int move_tasks(struct rq this_rq, int this_cpu, struct rq busiest,
		sd, idle, all_pinned, &this_best_prio);
		class = class->next;

		#ifdef CONFIG_PREEMPT
		/*
		* NEWIDLE balancing is a source of latency, so preemptible
		* kernels will stop after the first task is pulled to minimize
		* the critical section.
		*/
		if (idle == CPU_NEWLY_IDLE && this_rq->nr_running)
		break;

		#endif
		} while (class && max_load_move > total_load_moved);

		return total_load_moved > 0;
		@@ -8201,11 +8266,13 @@ static void init_rt_rq(struct rt_rq rt_rq, struct rq rq)
		__set_bit(MAX_RT_PRIO, array->bitmap);

		#if defined CONFIG_SMP \|\| defined CONFIG_RT_GROUP_SCHED
		rt_rq->highest_prio = MAX_RT_PRIO;
		rt_rq->highest_prio.curr = MAX_RT_PRIO;
		rt_rq->highest_prio.next = MAX_RT_PRIO;
		#endif
		#ifdef CONFIG_SMP
		rt_rq->rt_nr_migratory = 0;
		rt_rq->overloaded = 0;
		plist_head_init(&rq->rt.pushable_tasks, &rq->lock);
		#endif

		rt_rq->rt_time = 0;

kernel/sched_rt.c

+224 −100

Original line number	Diff line number	Diff line
		@@ -49,6 +49,24 @@ static void update_rt_migration(struct rq *rq)
		rq->rt.overloaded = 0;
		}
		}

		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);
		}

		#else

		#define enqueue_pushable_task(rq, p) do { } while (0)
		#define dequeue_pushable_task(rq, p) do { } while (0)

		#endif /* CONFIG_SMP */

		static inline struct task_struct rt_task_of(struct sched_rt_entity rt_se)
		@@ -108,7 +126,7 @@ static void sched_rt_rq_enqueue(struct rt_rq *rt_rq)
		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)
		if (rt_rq->highest_prio.curr < curr->prio)
		resched_task(curr);
		}
		}
		@@ -473,7 +491,7 @@ static inline int rt_se_prio(struct sched_rt_entity *rt_se)
		struct rt_rq *rt_rq = group_rt_rq(rt_se);

		if (rt_rq)
		return rt_rq->highest_prio;
		return rt_rq->highest_prio.curr;
		#endif

		return rt_task_of(rt_se)->prio;
		@@ -547,33 +565,64 @@ static void update_curr_rt(struct rq *rq)
		}
		}

		#if defined CONFIG_SMP \|\| defined CONFIG_RT_GROUP_SCHED

		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;
		}
		#endif

		static inline
		void inc_rt_tasks(struct sched_rt_entity rt_se, struct rt_rq rt_rq)
		{
		WARN_ON(!rt_prio(rt_se_prio(rt_se)));
		rt_rq->rt_nr_running++;
		#if defined CONFIG_SMP \|\| defined CONFIG_RT_GROUP_SCHED
		if (rt_se_prio(rt_se) < rt_rq->highest_prio) {
		int prio = rt_se_prio(rt_se);
		#ifdef CONFIG_SMP
		struct rq *rq = rq_of_rt_rq(rt_rq);
		#endif

		rt_rq->highest_prio = rt_se_prio(rt_se);
		WARN_ON(!rt_prio(prio));
		rt_rq->rt_nr_running++;
		#if defined CONFIG_SMP \|\| defined CONFIG_RT_GROUP_SCHED
		if (prio < rt_rq->highest_prio.curr) {

		/*
		* If the new task is higher in priority than anything on the
		* run-queue, we have a new high that must be published to
		* the world. We also know that the previous high becomes
		* our next-highest.
		*/
		rt_rq->highest_prio.next = rt_rq->highest_prio.curr;
		rt_rq->highest_prio.curr = prio;
		#ifdef CONFIG_SMP
		if (rq->online)
		cpupri_set(&rq->rd->cpupri, rq->cpu,
		rt_se_prio(rt_se));
		cpupri_set(&rq->rd->cpupri, rq->cpu, prio);
		#endif
		}
		} 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);
		#endif
		#ifdef CONFIG_SMP
		if (rt_se->nr_cpus_allowed > 1) {
		struct rq *rq = rq_of_rt_rq(rt_rq);

		if (rt_se->nr_cpus_allowed > 1)
		rq->rt.rt_nr_migratory++;
		}

		update_rt_migration(rq_of_rt_rq(rt_rq));
		update_rt_migration(rq);
		#endif
		#ifdef CONFIG_RT_GROUP_SCHED
		if (rt_se_boosted(rt_se))
		@@ -590,7 +639,8 @@ static inline
		void dec_rt_tasks(struct sched_rt_entity rt_se, struct rt_rq rt_rq)
		{
		#ifdef CONFIG_SMP
		int highest_prio = rt_rq->highest_prio;
		struct rq *rq = rq_of_rt_rq(rt_rq);
		int highest_prio = rt_rq->highest_prio.curr;
		#endif

		WARN_ON(!rt_prio(rt_se_prio(rt_se)));
		@@ -598,33 +648,34 @@ void dec_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_rq->rt_nr_running) {
		struct rt_prio_array *array;
		int prio = rt_se_prio(rt_se);

		WARN_ON(rt_se_prio(rt_se) < rt_rq->highest_prio);
		if (rt_se_prio(rt_se) == rt_rq->highest_prio) {
		/* recalculate */
		array = &rt_rq->active;
		rt_rq->highest_prio =
		WARN_ON(prio < rt_rq->highest_prio.curr);

		/*
		* This may have been our highest or next-highest priority
		* task and therefore we may have some recomputation to do
		*/
		if (prio == rt_rq->highest_prio.curr) {
		struct rt_prio_array *array = &rt_rq->active;

		rt_rq->highest_prio.curr =
		sched_find_first_bit(array->bitmap);
		} /* otherwise leave rq->highest prio alone */
		}

		if (prio <= rt_rq->highest_prio.next)
		rt_rq->highest_prio.next = next_prio(rq);
		} else
		rt_rq->highest_prio = MAX_RT_PRIO;
		rt_rq->highest_prio.curr = MAX_RT_PRIO;
		#endif
		#ifdef CONFIG_SMP
		if (rt_se->nr_cpus_allowed > 1) {
		struct rq *rq = rq_of_rt_rq(rt_rq);
		if (rt_se->nr_cpus_allowed > 1)
		rq->rt.rt_nr_migratory--;
		}

		if (rt_rq->highest_prio != highest_prio) {
		struct rq *rq = rq_of_rt_rq(rt_rq);

		if (rq->online)
		cpupri_set(&rq->rd->cpupri, rq->cpu,
		rt_rq->highest_prio);
		}
		if (rq->online && rt_rq->highest_prio.curr != highest_prio)
		cpupri_set(&rq->rd->cpupri, rq->cpu, rt_rq->highest_prio.curr);

		update_rt_migration(rq_of_rt_rq(rt_rq));
		update_rt_migration(rq);
		#endif /* CONFIG_SMP */
		#ifdef CONFIG_RT_GROUP_SCHED
		if (rt_se_boosted(rt_se))
		@@ -718,6 +769,9 @@ static void enqueue_task_rt(struct rq rq, struct task_struct p, int wakeup)

		enqueue_rt_entity(rt_se);

		if (!task_current(rq, p) && p->rt.nr_cpus_allowed > 1)
		enqueue_pushable_task(rq, p);

		inc_cpu_load(rq, p->se.load.weight);
		}

		@@ -728,6 +782,8 @@ static void dequeue_task_rt(struct rq rq, struct task_struct p, int sleep)
		update_curr_rt(rq);
		dequeue_rt_entity(rt_se);

		dequeue_pushable_task(rq, p);

		dec_cpu_load(rq, p->se.load.weight);
		}

		@@ -878,7 +934,7 @@ static struct sched_rt_entity pick_next_rt_entity(struct rq rq,
		return next;
		}

		static struct task_struct pick_next_task_rt(struct rq rq)
		static struct task_struct _pick_next_task_rt(struct rq rq)
		{
		struct sched_rt_entity *rt_se;
		struct task_struct *p;
		@@ -900,6 +956,18 @@ static struct task_struct pick_next_task_rt(struct rq 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);

		return p;
		}

		@@ -907,6 +975,13 @@ 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
		@@ -1072,7 +1147,7 @@ static struct rq find_lock_lowest_rq(struct task_struct task, struct rq *rq)
		}

		/* If this rq is still suitable use it. */
		if (lowest_rq->rt.highest_prio > task->prio)
		if (lowest_rq->rt.highest_prio.curr > task->prio)
		break;

		/* try again */
		@@ -1083,6 +1158,31 @@ 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;

		if (!has_pushable_tasks(rq))
		return NULL;

		p = plist_first_entry(&rq->rt.pushable_tasks,
		struct task_struct, pushable_tasks);

		BUG_ON(rq->cpu != task_cpu(p));
		BUG_ON(task_current(rq, p));
		BUG_ON(p->rt.nr_cpus_allowed <= 1);

		BUG_ON(!p->se.on_rq);
		BUG_ON(!rt_task(p));

		return p;
		}

		/*
		* 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
		@@ -1092,13 +1192,11 @@ static int push_rt_task(struct rq *rq)
		{
		struct task_struct *next_task;
		struct rq *lowest_rq;
		int ret = 0;
		int paranoid = RT_MAX_TRIES;

		if (!rq->rt.overloaded)
		return 0;

		next_task = pick_next_highest_task_rt(rq, -1);
		next_task = pick_next_pushable_task(rq);
		if (!next_task)
		return 0;

		@@ -1127,17 +1225,35 @@ static int push_rt_task(struct rq *rq)
		struct task_struct *task;
		/*
		* find lock_lowest_rq releases rq->lock
		* so it is possible that next_task has changed.
		* If it has, then try again.
		* 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.
		*/
		task = pick_next_highest_task_rt(rq, -1);
		if (unlikely(task != next_task) && task && paranoid--) {
		put_task_struct(next_task);
		next_task = task;
		goto retry;
		}
		goto out;
		}

		deactivate_task(rq, next_task, 0);
		set_task_cpu(next_task, lowest_rq->cpu);
		@@ -1147,23 +1263,12 @@ static int push_rt_task(struct rq *rq)

		double_unlock_balance(rq, lowest_rq);

		ret = 1;
		out:
		put_task_struct(next_task);

		return ret;
		return 1;
		}

		/*
		* TODO: Currently we just use the second highest prio task on
		* the queue, and stop when it can't migrate (or there's
		* no more RT tasks). There may be a case where a lower
		* priority RT task has a different affinity than the
		* higher RT task. In this case the lower RT task could
		* possibly be able to migrate where as the higher priority
		* RT task could not. We currently ignore this issue.
		* Enhancements are welcome!
		*/
		static void push_rt_tasks(struct rq *rq)
		{
		/* push_rt_task will return true if it moved an RT */
		@@ -1174,33 +1279,35 @@ static void push_rt_tasks(struct rq *rq)
		static int pull_rt_task(struct rq *this_rq)
		{
		int this_cpu = this_rq->cpu, ret = 0, cpu;
		struct task_struct p, next;
		struct task_struct *p;
		struct rq *src_rq;

		if (likely(!rt_overloaded(this_rq)))
		return 0;

		next = pick_next_task_rt(this_rq);

		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
		* steal our next task - hence we must cause
		* the caller to recalculate the next task
		* in that case:
		* alter this_rq
		*/
		if (double_lock_balance(this_rq, src_rq)) {
		struct task_struct *old_next = next;

		next = pick_next_task_rt(this_rq);
		if (next != old_next)
		ret = 1;
		}
		double_lock_balance(this_rq, src_rq);

		/*
		* Are there still pullable RT tasks?
		@@ -1214,7 +1321,7 @@ static int pull_rt_task(struct rq *this_rq)
		* Do we have an RT task that preempts
		* the to-be-scheduled task?
		*/
		if (p && (!next \|\| (p->prio < next->prio))) {
		if (p && (p->prio < this_rq->rt.highest_prio.curr)) {
		WARN_ON(p == src_rq->curr);
		WARN_ON(!p->se.on_rq);

		@@ -1224,12 +1331,9 @@ static int pull_rt_task(struct rq *this_rq)
		* 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 or
		* this_rq next task is lower in prio than
		* the current task on that rq.
		* current task on the run queue
		*/
		if (p->prio < src_rq->curr->prio \|\|
		(next && next->prio < src_rq->curr->prio))
		if (p->prio < src_rq->curr->prio)
		goto skip;

		ret = 1;
		@@ -1242,13 +1346,7 @@ static int pull_rt_task(struct rq *this_rq)
		* case there's an even higher prio task
		* in another runqueue. (low likelyhood
		* but possible)
		*
		* Update next so that we won't pick a task
		* on another cpu with a priority lower (or equal)
		* than the one we just picked.
		*/
		next = p;

		}
		skip:
		double_unlock_balance(this_rq, src_rq);
		@@ -1260,25 +1358,28 @@ static int pull_rt_task(struct rq *this_rq)
		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 > prev->prio)
		if (unlikely(rt_task(prev)) && rq->rt.highest_prio.curr > prev->prio)
		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)
		{
		/*
		* If we have more than one rt_task queued, then
		* see if we can push the other rt_tasks off to other CPUS.
		* Note we may release the rq lock, and since
		* the lock was owned by prev, we need to release it
		* first via finish_lock_switch and then reaquire it here.
		* This is only called if needs_post_schedule_rt() indicates that
		* we need to push tasks away
		*/
		if (unlikely(rq->rt.overloaded)) {
		spin_lock_irq(&rq->lock);
		push_rt_tasks(rq);
		spin_unlock_irq(&rq->lock);
		}
		}

		/*
		* If we are not running and we are not going to reschedule soon, we should
		@@ -1288,7 +1389,8 @@ static void task_wake_up_rt(struct rq rq, struct task_struct p)
		{
		if (!task_running(rq, p) &&
		!test_tsk_need_resched(rq->curr) &&
		rq->rt.overloaded)
		has_pushable_tasks(rq) &&
		p->rt.nr_cpus_allowed > 1)
		push_rt_tasks(rq);
		}

		@@ -1324,6 +1426,24 @@ static void set_cpus_allowed_rt(struct task_struct *p,
		if (p->se.on_rq && (weight != p->rt.nr_cpus_allowed)) {
		struct rq *rq = task_rq(p);

		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);

		/*
		* Requeue if our weight is changing and still > 1
		*/
		if (weight > 1)
		enqueue_pushable_task(rq, p);

		}

		if ((p->rt.nr_cpus_allowed <= 1) && (weight > 1)) {
		rq->rt.rt_nr_migratory++;
		} else if ((p->rt.nr_cpus_allowed > 1) && (weight <= 1)) {
		@@ -1346,7 +1466,7 @@ static void rq_online_rt(struct rq *rq)

		__enable_runtime(rq);

		cpupri_set(&rq->rd->cpupri, rq->cpu, rq->rt.highest_prio);
		cpupri_set(&rq->rd->cpupri, rq->cpu, rq->rt.highest_prio.curr);
		}

		/* Assumes rq->lock is held */
		@@ -1438,7 +1558,7 @@ static void prio_changed_rt(struct rq rq, struct task_struct p,
		* 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 && rq->curr == p)
		if (p->prio > rq->rt.highest_prio.curr && rq->curr == p)
		resched_task(p);
		#else
		/* For UP simply resched on drop of prio */
		@@ -1509,6 +1629,9 @@ static void set_curr_task_rt(struct rq *rq)
		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 const struct sched_class rt_sched_class = {
		@@ -1531,6 +1654,7 @@ 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,