/*
   * Real-Time Scheduling Class (mapped to the SCHED_FIFO and SCHED_RR
   * 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);
  }

  static inline struct rq *rq_of_rt_rq(struct rt_rq *rt_rq)
  {
  	return rt_rq->rq;
  }
  
  static inline struct rt_rq *rt_rq_of_se(struct sched_rt_entity *rt_se)
  {
  	return rt_se->rt_rq;
  }
  
  #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);
  }
  
  static inline struct rt_rq *rt_rq_of_se(struct sched_rt_entity *rt_se)
  {
  	struct task_struct *p = rt_task_of(rt_se);
  	struct rq *rq = task_rq(p);
  
  	return &rq->rt;
  }
  
  #endif /* CONFIG_RT_GROUP_SCHED */

  #ifdef CONFIG_SMP

  static inline int rt_overloaded(struct rq *rq)

  {

  	return atomic_read(&rq->rd->rto_count);

  }

  static inline void rt_set_overload(struct rq *rq)
  {

  	if (!rq->online)
  		return;

  	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
  	 * if we should look at the mask. It would be a shame
  	 * if we looked at the mask, but the mask was not
  	 * updated yet.
  	 */
  	wmb();

  	atomic_inc(&rq->rd->rto_count);

  }

  static inline void rt_clear_overload(struct rq *rq)
  {

  	if (!rq->online)
  		return;

  	/* the order here really doesn't matter */

  	atomic_dec(&rq->rd->rto_count);

  	cpumask_clear_cpu(rq->cpu, rq->rd->rto_mask);

  }

  static void update_rt_migration(struct rt_rq *rt_rq)

  {

  	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;

  		}

  	} else if (rt_rq->overloaded) {
  		rt_clear_overload(rq_of_rt_rq(rt_rq));
  		rt_rq->overloaded = 0;

  	}

  }

  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++;
  
  	update_rt_migration(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--;
  
  	update_rt_migration(rt_rq);
  }

  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);
  }

  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)

  {

  }

  static inline void dequeue_pushable_task(struct rq *rq, struct task_struct *p)
  {
  }

  static inline

  void inc_rt_migration(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq)
  {
  }

  static inline

  void dec_rt_migration(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq)
  {
  }

  #endif /* CONFIG_SMP */

  static inline int on_rt_rq(struct sched_rt_entity *rt_se)
  {
  	return !list_empty(&rt_se->run_list);
  }

  #ifdef CONFIG_RT_GROUP_SCHED

  static inline u64 sched_rt_runtime(struct rt_rq *rt_rq)

  {
  	if (!rt_rq->tg)

  		return RUNTIME_INF;

  	return rt_rq->rt_runtime;
  }
  
  static inline u64 sched_rt_period(struct rt_rq *rt_rq)
  {
  	return ktime_to_ns(rt_rq->tg->rt_bandwidth.rt_period);

  }

  typedef struct task_group *rt_rq_iter_t;

  static inline struct task_group *next_task_group(struct task_group *tg)
  {
  	do {
  		tg = list_entry_rcu(tg->list.next,
  			typeof(struct task_group), list);
  	} while (&tg->list != &task_groups && task_group_is_autogroup(tg));
  
  	if (&tg->list == &task_groups)
  		tg = NULL;
  
  	return tg;
  }
  
  #define for_each_rt_rq(rt_rq, iter, rq)					\
  	for (iter = container_of(&task_groups, typeof(*iter), list);	\
  		(iter = next_task_group(iter)) &&			\
  		(rt_rq = iter->rt_rq[cpu_of(rq)]);)

  static inline void list_add_leaf_rt_rq(struct rt_rq *rt_rq)
  {
  	list_add_rcu(&rt_rq->leaf_rt_rq_list,
  			&rq_of_rt_rq(rt_rq)->leaf_rt_rq_list);
  }
  
  static inline void list_del_leaf_rt_rq(struct rt_rq *rt_rq)
  {
  	list_del_rcu(&rt_rq->leaf_rt_rq_list);
  }

  #define for_each_leaf_rt_rq(rt_rq, rq) \

  	list_for_each_entry_rcu(rt_rq, &rq->leaf_rt_rq_list, leaf_rt_rq_list)

  #define for_each_sched_rt_entity(rt_se) \
  	for (; rt_se; rt_se = rt_se->parent)
  
  static inline struct rt_rq *group_rt_rq(struct sched_rt_entity *rt_se)
  {
  	return rt_se->my_q;
  }

  static void enqueue_rt_entity(struct sched_rt_entity *rt_se, bool head);

  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;

  	int cpu = cpu_of(rq_of_rt_rq(rt_rq));
  
  	rt_se = rt_rq->tg->rt_se[cpu];

  	if (rt_rq->rt_nr_running) {
  		if (rt_se && !on_rt_rq(rt_se))

  			enqueue_rt_entity(rt_se, false);

  		if (rt_rq->highest_prio.curr < curr->prio)

  			resched_task(curr);

  	}
  }

  static void sched_rt_rq_dequeue(struct rt_rq *rt_rq)

  {

  	struct sched_rt_entity *rt_se;

  	int cpu = cpu_of(rq_of_rt_rq(rt_rq));

  	rt_se = rt_rq->tg->rt_se[cpu];

  
  	if (rt_se && on_rt_rq(rt_se))
  		dequeue_rt_entity(rt_se);
  }

  static inline int rt_rq_throttled(struct rt_rq *rt_rq)
  {
  	return rt_rq->rt_throttled && !rt_rq->rt_nr_boosted;
  }
  
  static int rt_se_boosted(struct sched_rt_entity *rt_se)
  {
  	struct rt_rq *rt_rq = group_rt_rq(rt_se);
  	struct task_struct *p;
  
  	if (rt_rq)
  		return !!rt_rq->rt_nr_boosted;
  
  	p = rt_task_of(rt_se);
  	return p->prio != p->normal_prio;
  }

  #ifdef CONFIG_SMP

  static inline const struct cpumask *sched_rt_period_mask(void)

  {
  	return cpu_rq(smp_processor_id())->rd->span;
  }

  #else

  static inline const struct cpumask *sched_rt_period_mask(void)

  {

  	return cpu_online_mask;

  }
  #endif

  static inline
  struct rt_rq *sched_rt_period_rt_rq(struct rt_bandwidth *rt_b, int cpu)

  {

  	return container_of(rt_b, struct task_group, rt_bandwidth)->rt_rq[cpu];
  }

  static inline struct rt_bandwidth *sched_rt_bandwidth(struct rt_rq *rt_rq)
  {
  	return &rt_rq->tg->rt_bandwidth;
  }

  #else /* !CONFIG_RT_GROUP_SCHED */

  
  static inline u64 sched_rt_runtime(struct rt_rq *rt_rq)
  {

  	return rt_rq->rt_runtime;
  }
  
  static inline u64 sched_rt_period(struct rt_rq *rt_rq)
  {
  	return ktime_to_ns(def_rt_bandwidth.rt_period);

  }

  typedef struct rt_rq *rt_rq_iter_t;
  
  #define for_each_rt_rq(rt_rq, iter, rq) \
  	for ((void) iter, rt_rq = &rq->rt; rt_rq; rt_rq = NULL)

  static inline void list_add_leaf_rt_rq(struct rt_rq *rt_rq)
  {
  }
  
  static inline void list_del_leaf_rt_rq(struct rt_rq *rt_rq)
  {
  }

  #define for_each_leaf_rt_rq(rt_rq, rq) \
  	for (rt_rq = &rq->rt; rt_rq; rt_rq = NULL)

  #define for_each_sched_rt_entity(rt_se) \
  	for (; rt_se; rt_se = NULL)
  
  static inline struct rt_rq *group_rt_rq(struct sched_rt_entity *rt_se)
  {
  	return NULL;
  }

  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)

  {
  }

  static inline int rt_rq_throttled(struct rt_rq *rt_rq)
  {
  	return rt_rq->rt_throttled;
  }

  static inline const struct cpumask *sched_rt_period_mask(void)

  {

  	return cpu_online_mask;

  }
  
  static inline
  struct rt_rq *sched_rt_period_rt_rq(struct rt_bandwidth *rt_b, int cpu)
  {
  	return &cpu_rq(cpu)->rt;
  }

  static inline struct rt_bandwidth *sched_rt_bandwidth(struct rt_rq *rt_rq)
  {
  	return &def_rt_bandwidth;
  }

  #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);
  	struct root_domain *rd = cpu_rq(smp_processor_id())->rd;
  	int i, weight, more = 0;
  	u64 rt_period;

  	weight = cpumask_weight(rd->span);

  	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);
  		s64 diff;
  
  		if (iter == rt_rq)
  			continue;

  		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
  		 * 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) {

  			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;
  			rt_rq->rt_runtime += diff;
  			more = 1;
  			if (rt_rq->rt_runtime == rt_period) {

  				raw_spin_unlock(&iter->rt_runtime_lock);

  				break;
  			}
  		}

  next:

  		raw_spin_unlock(&iter->rt_runtime_lock);

  	}

  	raw_spin_unlock(&rt_b->rt_runtime_lock);

  
  	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;

  	rt_rq_iter_t iter;

  	struct rt_rq *rt_rq;
  
  	if (unlikely(!scheduler_running))
  		return;

  	for_each_rt_rq(rt_rq, iter, rq) {

  		struct rt_bandwidth *rt_b = sched_rt_bandwidth(rt_rq);
  		s64 want;
  		int i;

  		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
  		 * 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;

  		raw_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;

  		/*
  		 * 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;

  			/*
  			 * Can't reclaim from ourselves or disabled runqueues.
  			 */

  			if (iter == rt_rq || iter->rt_runtime == RUNTIME_INF)

  				continue;

  			raw_spin_lock(&iter->rt_runtime_lock);

  			if (want > 0) {
  				diff = min_t(s64, iter->rt_runtime, want);
  				iter->rt_runtime -= diff;
  				want -= diff;
  			} else {
  				iter->rt_runtime -= want;
  				want -= want;
  			}

  			raw_spin_unlock(&iter->rt_runtime_lock);

  
  			if (!want)
  				break;
  		}

  		raw_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;

  		raw_spin_unlock(&rt_rq->rt_runtime_lock);
  		raw_spin_unlock(&rt_b->rt_runtime_lock);

  	}
  }
  
  static void disable_runtime(struct rq *rq)
  {
  	unsigned long flags;

  	raw_spin_lock_irqsave(&rq->lock, flags);

  	__disable_runtime(rq);

  	raw_spin_unlock_irqrestore(&rq->lock, flags);

  }
  
  static void __enable_runtime(struct rq *rq)
  {

  	rt_rq_iter_t iter;

  	struct rt_rq *rt_rq;
  
  	if (unlikely(!scheduler_running))
  		return;

  	/*
  	 * Reset each runqueue's bandwidth settings
  	 */

  	for_each_rt_rq(rt_rq, iter, rq) {

  		struct rt_bandwidth *rt_b = sched_rt_bandwidth(rt_rq);

  		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;

  		raw_spin_unlock(&rt_rq->rt_runtime_lock);
  		raw_spin_unlock(&rt_b->rt_runtime_lock);

  	}
  }
  
  static void enable_runtime(struct rq *rq)
  {
  	unsigned long flags;

  	raw_spin_lock_irqsave(&rq->lock, flags);

  	__enable_runtime(rq);

  	raw_spin_unlock_irqrestore(&rq->lock, flags);

  }

  static int balance_runtime(struct rt_rq *rt_rq)
  {
  	int more = 0;
  
  	if (rt_rq->rt_time > rt_rq->rt_runtime) {

  		raw_spin_unlock(&rt_rq->rt_runtime_lock);

  		more = do_balance_runtime(rt_rq);

  		raw_spin_lock(&rt_rq->rt_runtime_lock);

  	}
  
  	return more;
  }

  #else /* !CONFIG_SMP */

  static inline int balance_runtime(struct rt_rq *rt_rq)
  {
  	return 0;
  }

  #endif /* CONFIG_SMP */

  static int do_sched_rt_period_timer(struct rt_bandwidth *rt_b, int overrun)
  {
  	int i, idle = 1;

  	const struct cpumask *span;

  	if (!rt_bandwidth_enabled() || rt_b->rt_runtime == RUNTIME_INF)

  		return 1;
  
  	span = sched_rt_period_mask();

  	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);

  		raw_spin_lock(&rq->lock);

  		if (rt_rq->rt_time) {
  			u64 runtime;

  			raw_spin_lock(&rt_rq->rt_runtime_lock);

  			if (rt_rq->rt_throttled)
  				balance_runtime(rt_rq);
  			runtime = rt_rq->rt_runtime;
  			rt_rq->rt_time -= min(rt_rq->rt_time, overrun*runtime);
  			if (rt_rq->rt_throttled && rt_rq->rt_time < runtime) {
  				rt_rq->rt_throttled = 0;
  				enqueue = 1;

  
  				/*
  				 * Force a clock update if the CPU was idle,
  				 * lest wakeup -> unthrottle time accumulate.
  				 */
  				if (rt_rq->rt_nr_running && rq->curr == rq->idle)
  					rq->skip_clock_update = -1;

  			}
  			if (rt_rq->rt_time || rt_rq->rt_nr_running)
  				idle = 0;

  			raw_spin_unlock(&rt_rq->rt_runtime_lock);

  		} else if (rt_rq->rt_nr_running) {

  			idle = 0;

  			if (!rt_rq_throttled(rt_rq))
  				enqueue = 1;
  		}

  
  		if (enqueue)
  			sched_rt_rq_enqueue(rt_rq);

  		raw_spin_unlock(&rq->lock);

  	}
  
  	return idle;
  }

  static inline int rt_se_prio(struct sched_rt_entity *rt_se)
  {

  #ifdef CONFIG_RT_GROUP_SCHED

  	struct rt_rq *rt_rq = group_rt_rq(rt_se);
  
  	if (rt_rq)

  		return rt_rq->highest_prio.curr;

  #endif
  
  	return rt_task_of(rt_se)->prio;
  }

  static int sched_rt_runtime_exceeded(struct rt_rq *rt_rq)

  {

  	u64 runtime = sched_rt_runtime(rt_rq);

  	if (rt_rq->rt_throttled)

  		return rt_rq_throttled(rt_rq);

  	if (sched_rt_runtime(rt_rq) >= sched_rt_period(rt_rq))
  		return 0;

  	balance_runtime(rt_rq);
  	runtime = sched_rt_runtime(rt_rq);
  	if (runtime == RUNTIME_INF)
  		return 0;

  	if (rt_rq->rt_time > runtime) {

  		rt_rq->rt_throttled = 1;

  		if (rt_rq_throttled(rt_rq)) {

  			sched_rt_rq_dequeue(rt_rq);

  			return 1;
  		}

  	}
  
  	return 0;
  }

  /*
   * Update the current task's runtime statistics. Skip current tasks that
   * are not in our scheduling class.
   */

  static void update_curr_rt(struct rq *rq)

  {
  	struct task_struct *curr = rq->curr;

  	struct sched_rt_entity *rt_se = &curr->rt;
  	struct rt_rq *rt_rq = rt_rq_of_se(rt_se);

  	u64 delta_exec;

  	if (curr->sched_class != &rt_sched_class)

  		return;

  	delta_exec = rq->clock_task - curr->se.exec_start;

  	if (unlikely((s64)delta_exec < 0))
  		delta_exec = 0;

  	schedstat_set(curr->se.statistics.exec_max, max(curr->se.statistics.exec_max, delta_exec));

  
  	curr->se.sum_exec_runtime += delta_exec;

  	account_group_exec_runtime(curr, delta_exec);

  	curr->se.exec_start = rq->clock_task;

  	cpuacct_charge(curr, delta_exec);

  	sched_rt_avg_update(rq, delta_exec);

  	if (!rt_bandwidth_enabled())
  		return;

  	for_each_sched_rt_entity(rt_se) {
  		rt_rq = rt_rq_of_se(rt_se);

  		if (sched_rt_runtime(rt_rq) != RUNTIME_INF) {

  			raw_spin_lock(&rt_rq->rt_runtime_lock);

  			rt_rq->rt_time += delta_exec;
  			if (sched_rt_runtime_exceeded(rt_rq))
  				resched_task(curr);

  			raw_spin_unlock(&rt_rq->rt_runtime_lock);

  		}

  	}

  }

  #if defined CONFIG_SMP

  
  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;
  }

  static void
  inc_rt_prio_smp(struct rt_rq *rt_rq, int prio, int prev_prio)

  {

  	struct rq *rq = rq_of_rt_rq(rt_rq);

  	if (prio < prev_prio) {

  		/*
  		 * If the new task is higher in priority than anything on the

  		 * run-queue, we know that the previous high becomes our
  		 * next-highest.

  		 */

  		rt_rq->highest_prio.next = prev_prio;

  
  		if (rq->online)

  			cpupri_set(&rq->rd->cpupri, rq->cpu, prio);

  	} 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);

  }

  static void
  dec_rt_prio_smp(struct rt_rq *rt_rq, int prio, int prev_prio)
  {
  	struct rq *rq = rq_of_rt_rq(rt_rq);

  	if (rt_rq->rt_nr_running && (prio <= rt_rq->highest_prio.next))
  		rt_rq->highest_prio.next = next_prio(rq);
  
  	if (rq->online && rt_rq->highest_prio.curr != prev_prio)
  		cpupri_set(&rq->rd->cpupri, rq->cpu, rt_rq->highest_prio.curr);

  }

  #else /* CONFIG_SMP */

  static inline

  void inc_rt_prio_smp(struct rt_rq *rt_rq, int prio, int prev_prio) {}
  static inline
  void dec_rt_prio_smp(struct rt_rq *rt_rq, int prio, int prev_prio) {}
  
  #endif /* CONFIG_SMP */

  #if defined CONFIG_SMP || defined CONFIG_RT_GROUP_SCHED

  static void
  inc_rt_prio(struct rt_rq *rt_rq, int prio)
  {
  	int prev_prio = rt_rq->highest_prio.curr;
  
  	if (prio < prev_prio)
  		rt_rq->highest_prio.curr = prio;
  
  	inc_rt_prio_smp(rt_rq, prio, prev_prio);
  }
  
  static void
  dec_rt_prio(struct rt_rq *rt_rq, int prio)
  {
  	int prev_prio = rt_rq->highest_prio.curr;

  	if (rt_rq->rt_nr_running) {

  		WARN_ON(prio < prev_prio);

  		/*

  		 * This may have been our highest task, and therefore
  		 * we may have some recomputation to do

  		 */

  		if (prio == prev_prio) {

  			struct rt_prio_array *array = &rt_rq->active;
  
  			rt_rq->highest_prio.curr =

  				sched_find_first_bit(array->bitmap);

  		}

  	} else

  		rt_rq->highest_prio.curr = MAX_RT_PRIO;

  	dec_rt_prio_smp(rt_rq, prio, prev_prio);
  }

  #else
  
  static inline void inc_rt_prio(struct rt_rq *rt_rq, int prio) {}
  static inline void dec_rt_prio(struct rt_rq *rt_rq, int prio) {}
  
  #endif /* CONFIG_SMP || CONFIG_RT_GROUP_SCHED */

  #ifdef CONFIG_RT_GROUP_SCHED

  
  static void
  inc_rt_group(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq)
  {
  	if (rt_se_boosted(rt_se))
  		rt_rq->rt_nr_boosted++;
  
  	if (rt_rq->tg)
  		start_rt_bandwidth(&rt_rq->tg->rt_bandwidth);
  }
  
  static void
  dec_rt_group(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq)
  {

  	if (rt_se_boosted(rt_se))
  		rt_rq->rt_nr_boosted--;
  
  	WARN_ON(!rt_rq->rt_nr_running && rt_rq->rt_nr_boosted);

  }
  
  #else /* CONFIG_RT_GROUP_SCHED */
  
  static void
  inc_rt_group(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq)
  {
  	start_rt_bandwidth(&def_rt_bandwidth);
  }
  
  static inline
  void dec_rt_group(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq) {}
  
  #endif /* CONFIG_RT_GROUP_SCHED */
  
  static inline
  void inc_rt_tasks(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq)
  {
  	int prio = rt_se_prio(rt_se);
  
  	WARN_ON(!rt_prio(prio));
  	rt_rq->rt_nr_running++;
  
  	inc_rt_prio(rt_rq, prio);
  	inc_rt_migration(rt_se, rt_rq);
  	inc_rt_group(rt_se, rt_rq);
  }
  
  static inline
  void dec_rt_tasks(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq)
  {
  	WARN_ON(!rt_prio(rt_se_prio(rt_se)));
  	WARN_ON(!rt_rq->rt_nr_running);
  	rt_rq->rt_nr_running--;
  
  	dec_rt_prio(rt_rq, rt_se_prio(rt_se));
  	dec_rt_migration(rt_se, rt_rq);
  	dec_rt_group(rt_se, rt_rq);

  }

  static void __enqueue_rt_entity(struct sched_rt_entity *rt_se, bool head)

  {

  	struct rt_rq *rt_rq = rt_rq_of_se(rt_se);
  	struct rt_prio_array *array = &rt_rq->active;
  	struct rt_rq *group_rq = group_rt_rq(rt_se);

  	struct list_head *queue = array->queue + rt_se_prio(rt_se);

  	/*
  	 * Don't enqueue the group if its throttled, or when empty.
  	 * The latter is a consequence of the former when a child group
  	 * get throttled and the current group doesn't have any other
  	 * active members.
  	 */
  	if (group_rq && (rt_rq_throttled(group_rq) || !group_rq->rt_nr_running))

  		return;

  	if (!rt_rq->rt_nr_running)
  		list_add_leaf_rt_rq(rt_rq);

  	if (head)
  		list_add(&rt_se->run_list, queue);
  	else
  		list_add_tail(&rt_se->run_list, queue);

  	__set_bit(rt_se_prio(rt_se), array->bitmap);

  	inc_rt_tasks(rt_se, rt_rq);
  }

  static void __dequeue_rt_entity(struct sched_rt_entity *rt_se)

  {
  	struct rt_rq *rt_rq = rt_rq_of_se(rt_se);
  	struct rt_prio_array *array = &rt_rq->active;
  
  	list_del_init(&rt_se->run_list);
  	if (list_empty(array->queue + rt_se_prio(rt_se)))
  		__clear_bit(rt_se_prio(rt_se), array->bitmap);
  
  	dec_rt_tasks(rt_se, rt_rq);

  	if (!rt_rq->rt_nr_running)
  		list_del_leaf_rt_rq(rt_rq);

  }
  
  /*
   * Because the prio of an upper entry depends on the lower
   * entries, we must remove entries top - down.

   */

  static void dequeue_rt_stack(struct sched_rt_entity *rt_se)

  {

  	struct sched_rt_entity *back = NULL;

  	for_each_sched_rt_entity(rt_se) {
  		rt_se->back = back;
  		back = rt_se;
  	}
  
  	for (rt_se = back; rt_se; rt_se = rt_se->back) {
  		if (on_rt_rq(rt_se))

  			__dequeue_rt_entity(rt_se);
  	}
  }

  static void enqueue_rt_entity(struct sched_rt_entity *rt_se, bool head)

  {
  	dequeue_rt_stack(rt_se);
  	for_each_sched_rt_entity(rt_se)

  		__enqueue_rt_entity(rt_se, head);

  }
  
  static void dequeue_rt_entity(struct sched_rt_entity *rt_se)
  {
  	dequeue_rt_stack(rt_se);
  
  	for_each_sched_rt_entity(rt_se) {
  		struct rt_rq *rt_rq = group_rt_rq(rt_se);
  
  		if (rt_rq && rt_rq->rt_nr_running)

  			__enqueue_rt_entity(rt_se, false);

  	}

  }
  
  /*
   * Adding/removing a task to/from a priority array:
   */

  static void

  enqueue_task_rt(struct rq *rq, struct task_struct *p, int flags)

  {
  	struct sched_rt_entity *rt_se = &p->rt;

  	if (flags & ENQUEUE_WAKEUP)

  		rt_se->timeout = 0;

  	enqueue_rt_entity(rt_se, flags & ENQUEUE_HEAD);

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

  }

  static void dequeue_task_rt(struct rq *rq, struct task_struct *p, int flags)

  {

  	struct sched_rt_entity *rt_se = &p->rt;

  	update_curr_rt(rq);

  	dequeue_rt_entity(rt_se);

  	dequeue_pushable_task(rq, p);

  }
  
  /*
   * Put task to the end of the run list without the overhead of dequeue
   * followed by enqueue.
   */

  static void
  requeue_rt_entity(struct rt_rq *rt_rq, struct sched_rt_entity *rt_se, int head)

  {

  	if (on_rt_rq(rt_se)) {

  		struct rt_prio_array *array = &rt_rq->active;
  		struct list_head *queue = array->queue + rt_se_prio(rt_se);
  
  		if (head)
  			list_move(&rt_se->run_list, queue);
  		else
  			list_move_tail(&rt_se->run_list, queue);

  	}

  }

  static void requeue_task_rt(struct rq *rq, struct task_struct *p, int head)

  {

  	struct sched_rt_entity *rt_se = &p->rt;
  	struct rt_rq *rt_rq;

  	for_each_sched_rt_entity(rt_se) {
  		rt_rq = rt_rq_of_se(rt_se);

  		requeue_rt_entity(rt_rq, rt_se, head);

  	}

  }

  static void yield_task_rt(struct rq *rq)

  {

  	requeue_task_rt(rq, rq->curr, 0);

  }

  #ifdef CONFIG_SMP

  static int find_lowest_rq(struct task_struct *task);

  static int

  select_task_rq_rt(struct task_struct *p, int sd_flag, int flags)

  {

  	struct task_struct *curr;
  	struct rq *rq;
  	int cpu;

  	if (sd_flag != SD_BALANCE_WAKE)

  		return smp_processor_id();

  	cpu = task_cpu(p);
  	rq = cpu_rq(cpu);
  
  	rcu_read_lock();
  	curr = ACCESS_ONCE(rq->curr); /* unlocked access */

  	/*

  	 * If the current task on @p's runqueue is an RT task, then

  	 * try to see if we can wake this RT task up on another
  	 * runqueue. Otherwise simply start this RT task
  	 * on its current runqueue.
  	 *

  	 * We want to avoid overloading runqueues. If the woken
  	 * task is a higher priority, then it will stay on this CPU
  	 * and the lower prio task should be moved to another CPU.
  	 * Even though this will probably make the lower prio task
  	 * lose its cache, we do not want to bounce a higher task
  	 * around just because it gave up its CPU, perhaps for a
  	 * lock?
  	 *
  	 * For equal prio tasks, we just let the scheduler sort it out.

  	 *
  	 * Otherwise, just let it ride on the affined RQ and the
  	 * post-schedule router will push the preempted task away
  	 *
  	 * This test is optimistic, if we get it wrong the load-balancer
  	 * will have to sort it out.

  	 */

  	if (curr && unlikely(rt_task(curr)) &&
  	    (curr->rt.nr_cpus_allowed < 2 ||

  	     curr->prio <= p->prio) &&

  	    (p->rt.nr_cpus_allowed > 1)) {

  		int target = find_lowest_rq(p);

  		if (target != -1)
  			cpu = target;

  	}

  	rcu_read_unlock();

  	return cpu;

  }

  
  static void check_preempt_equal_prio(struct rq *rq, struct task_struct *p)
  {

  	if (rq->curr->rt.nr_cpus_allowed == 1)
  		return;

  	if (p->rt.nr_cpus_allowed != 1

  	    && cpupri_find(&rq->rd->cpupri, p, NULL))
  		return;

  	if (!cpupri_find(&rq->rd->cpupri, rq->curr, NULL))
  		return;

  
  	/*
  	 * There appears to be other cpus that can accept
  	 * current and none to run 'p', so lets reschedule
  	 * to try and push current away:
  	 */
  	requeue_task_rt(rq, p, 1);
  	resched_task(rq->curr);
  }

  #endif /* CONFIG_SMP */

  /*
   * 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 flags)

  {

  	if (p->prio < rq->curr->prio) {

  		resched_task(rq->curr);

  		return;
  	}
  
  #ifdef CONFIG_SMP
  	/*
  	 * If:
  	 *
  	 * - the newly woken task is of equal priority to the current task
  	 * - the newly woken task is non-migratable while current is migratable
  	 * - current will be preempted on the next reschedule
  	 *
  	 * we should check to see if current can readily move to a different
  	 * cpu.  If so, we will reschedule to allow the push logic to try
  	 * to move current somewhere else, making room for our non-migratable
  	 * task.
  	 */

  	if (p->prio == rq->curr->prio && !test_tsk_need_resched(rq->curr))

  		check_preempt_equal_prio(rq, p);

  #endif

  }

  static struct sched_rt_entity *pick_next_rt_entity(struct rq *rq,
  						   struct rt_rq *rt_rq)

  {

  	struct rt_prio_array *array = &rt_rq->active;
  	struct sched_rt_entity *next = NULL;

  	struct list_head *queue;
  	int idx;
  
  	idx = sched_find_first_bit(array->bitmap);

  	BUG_ON(idx >= MAX_RT_PRIO);

  
  	queue = array->queue + idx;

  	next = list_entry(queue->next, struct sched_rt_entity, run_list);

  	return next;
  }

  static struct task_struct *_pick_next_task_rt(struct rq *rq)

  {
  	struct sched_rt_entity *rt_se;
  	struct task_struct *p;
  	struct rt_rq *rt_rq;

  	rt_rq = &rq->rt;

  	if (!rt_rq->rt_nr_running)

  		return NULL;

  	if (rt_rq_throttled(rt_rq))

  		return NULL;
  
  	do {
  		rt_se = pick_next_rt_entity(rq, rt_rq);

  		BUG_ON(!rt_se);

  		rt_rq = group_rt_rq(rt_se);
  	} while (rt_rq);
  
  	p = rt_task_of(rt_se);

  	p->se.exec_start = rq->clock_task;

  
  	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);

  #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;

  }

  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 (on_rt_rq(&p->rt) && p->rt.nr_cpus_allowed > 1)

  		enqueue_pushable_task(rq, p);

  }

  #ifdef CONFIG_SMP

  /* Only try algorithms three times */
  #define RT_MAX_TRIES 3

  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 || cpumask_test_cpu(cpu, &p->cpus_allowed)) &&

  	    (p->rt.nr_cpus_allowed > 1))

  		return 1;
  	return 0;
  }

  /* Return the second highest RT task, NULL otherwise */

  static struct task_struct *pick_next_highest_task_rt(struct rq *rq, int cpu)

  {

  	struct task_struct *next = NULL;
  	struct sched_rt_entity *rt_se;
  	struct rt_prio_array *array;
  	struct rt_rq *rt_rq;

  	int idx;

  	for_each_leaf_rt_rq(rt_rq, rq) {
  		array = &rt_rq->active;
  		idx = sched_find_first_bit(array->bitmap);

  next_idx:

  		if (idx >= MAX_RT_PRIO)
  			continue;
  		if (next && next->prio < idx)
  			continue;
  		list_for_each_entry(rt_se, array->queue + idx, run_list) {

  			struct task_struct *p;
  
  			if (!rt_entity_is_task(rt_se))
  				continue;
  
  			p = rt_task_of(rt_se);

  			if (pick_rt_task(rq, p, cpu)) {
  				next = p;
  				break;
  			}
  		}
  		if (!next) {
  			idx = find_next_bit(array->bitmap, MAX_RT_PRIO, idx+1);
  			goto next_idx;
  		}

  	}

  	return next;
  }

  static DEFINE_PER_CPU(cpumask_var_t, local_cpu_mask);

  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);

  	/* Make sure the mask is initialized first */
  	if (unlikely(!lowest_mask))
  		return -1;

  	if (task->rt.nr_cpus_allowed == 1)
  		return -1; /* No other targets possible */

  	if (!cpupri_find(&task_rq(task)->rd->cpupri, task, lowest_mask))
  		return -1; /* No targets found */

  
  	/*
  	 * 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.
  	 *
  	 * We prioritize the last cpu that the task executed on since
  	 * it is most likely cache-hot in that location.
  	 */

  	if (cpumask_test_cpu(cpu, lowest_mask))

  		return cpu;
  
  	/*
  	 * Otherwise, we consult the sched_domains span maps to figure
  	 * out which cpu is logically closest to our hot cache data.
  	 */

  	if (!cpumask_test_cpu(this_cpu, lowest_mask))
  		this_cpu = -1; /* Skip this_cpu opt if not among lowest */

  	rcu_read_lock();

  	for_each_domain(cpu, sd) {
  		if (sd->flags & SD_WAKE_AFFINE) {
  			int 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))) {
  				rcu_read_unlock();

  				return this_cpu;

  			}

  
  			best_cpu = cpumask_first_and(lowest_mask,
  						     sched_domain_span(sd));

  			if (best_cpu < nr_cpu_ids) {
  				rcu_read_unlock();

  				return best_cpu;

  			}

  		}
  	}

  	rcu_read_unlock();

  
  	/*
  	 * And finally, if there were no matches within the domains
  	 * just give the caller *something* to work with from the compatible
  	 * locations.
  	 */

  	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 */

  static struct rq *find_lock_lowest_rq(struct task_struct *task, struct rq *rq)

  {
  	struct rq *lowest_rq = NULL;

  	int tries;

  	int cpu;

  	for (tries = 0; tries < RT_MAX_TRIES; tries++) {
  		cpu = find_lowest_rq(task);

  		if ((cpu == -1) || (cpu == rq->cpu))

  			break;

  		lowest_rq = cpu_rq(cpu);

  		/* if the prio of this runqueue changed, try again */

  		if (double_lock_balance(rq, lowest_rq)) {

  			/*
  			 * We had to unlock the run queue. In
  			 * the mean time, task could have
  			 * migrated already or had its affinity changed.
  			 * Also make sure that it wasn't scheduled on its rq.
  			 */

  			if (unlikely(task_rq(task) != rq ||

  				     !cpumask_test_cpu(lowest_rq->cpu,
  						       &task->cpus_allowed) ||

  				     task_running(rq, task) ||

  				     !task->on_rq)) {

  				raw_spin_unlock(&lowest_rq->lock);

  				lowest_rq = NULL;
  				break;
  			}
  		}
  
  		/* If this rq is still suitable use it. */

  		if (lowest_rq->rt.highest_prio.curr > task->prio)

  			break;
  
  		/* try again */

  		double_unlock_balance(rq, lowest_rq);

  		lowest_rq = NULL;
  	}
  
  	return lowest_rq;
  }

  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->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
   * of lesser priority.
   */

  static int push_rt_task(struct rq *rq)

  {
  	struct task_struct *next_task;
  	struct rq *lowest_rq;

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

  	next_task = pick_next_pushable_task(rq);

  	if (!next_task)
  		return 0;

  retry:

  	if (unlikely(next_task == rq->curr)) {

  		WARN_ON(1);

  		return 0;

  	}

  
  	/*
  	 * It's possible that the next_task slipped in of
  	 * higher priority than current. If that's the case
  	 * just reschedule current.
  	 */

  	if (unlikely(next_task->prio < rq->curr->prio)) {
  		resched_task(rq->curr);

  		return 0;
  	}

  	/* We might release rq lock */

  	get_task_struct(next_task);
  
  	/* find_lock_lowest_rq locks the rq if found */

  	lowest_rq = find_lock_lowest_rq(next_task, rq);

  	if (!lowest_rq) {
  		struct task_struct *task;
  		/*

  		 * find lock_lowest_rq releases rq->lock

  		 * 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 hasn't 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.

  		 */

  		put_task_struct(next_task);
  		next_task = task;
  		goto retry;

  	}

  	deactivate_task(rq, next_task, 0);

  	set_task_cpu(next_task, lowest_rq->cpu);
  	activate_task(lowest_rq, next_task, 0);
  
  	resched_task(lowest_rq->curr);

  	double_unlock_balance(rq, lowest_rq);

  out:
  	put_task_struct(next_task);

  	return 1;

  }

  static void push_rt_tasks(struct rq *rq)
  {
  	/* push_rt_task will return true if it moved an RT */
  	while (push_rt_task(rq))
  		;
  }

  static int pull_rt_task(struct rq *this_rq)
  {

  	int this_cpu = this_rq->cpu, ret = 0, cpu;

  	struct task_struct *p;

  	struct rq *src_rq;

  	if (likely(!rt_overloaded(this_rq)))

  		return 0;

  	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

  		 * alter this_rq

  		 */

  		double_lock_balance(this_rq, src_rq);

  
  		/*
  		 * Are there still pullable RT tasks?
  		 */

  		if (src_rq->rt.rt_nr_running <= 1)
  			goto skip;

  		p = pick_next_highest_task_rt(src_rq, this_cpu);
  
  		/*
  		 * Do we have an RT task that preempts
  		 * the to-be-scheduled task?
  		 */

  		if (p && (p->prio < this_rq->rt.highest_prio.curr)) {

  			WARN_ON(p == src_rq->curr);

  			WARN_ON(!p->on_rq);

  
  			/*
  			 * There's a chance that p is higher in priority
  			 * than what's currently running on its cpu.
  			 * 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

  			 */

  			if (p->prio < src_rq->curr->prio)

  				goto skip;

  
  			ret = 1;
  
  			deactivate_task(src_rq, p, 0);
  			set_task_cpu(p, this_cpu);
  			activate_task(this_rq, p, 0);
  			/*
  			 * We continue with the search, just in
  			 * case there's an even higher prio task

  			 * in another runqueue. (low likelihood

  			 * but possible)

  			 */

  		}

  skip:

  		double_unlock_balance(this_rq, src_rq);

  	}
  
  	return ret;
  }

  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 (rq->rt.highest_prio.curr > prev->prio)

  		pull_rt_task(rq);
  }

  static void post_schedule_rt(struct rq *rq)

  {

  	push_rt_tasks(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_woken_rt(struct rq *rq, struct task_struct *p)

  {

  	if (!task_running(rq, p) &&

  	    !test_tsk_need_resched(rq->curr) &&

  	    has_pushable_tasks(rq) &&

  	    p->rt.nr_cpus_allowed > 1 &&

  	    rt_task(rq->curr) &&

  	    (rq->curr->rt.nr_cpus_allowed < 2 ||

  	     rq->curr->prio <= p->prio))

  		push_rt_tasks(rq);
  }

  static void set_cpus_allowed_rt(struct task_struct *p,

  				const struct cpumask *new_mask)

  {

  	int weight = cpumask_weight(new_mask);

  
  	BUG_ON(!rt_task(p));
  
  	/*
  	 * Update the migration status of the RQ if we have an RT task
  	 * which is running AND changing its weight value.
  	 */

  	if (p->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);
  
  		}