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Commit 07b4032c authored by Gregory Haskins's avatar Gregory Haskins Committed by Ingo Molnar
Browse files

sched: break out search for RT tasks 



Isolate the search logic into a function so that it can be used later
in places other than find_locked_lowest_rq().

Signed-off-by: default avatarGregory Haskins <ghaskins@novell.com>
Signed-off-by: default avatarSteven Rostedt <srostedt@redhat.com>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
parent e7693a36

kernel/sched_rt.c

+39 −27
Original line number Diff line number Diff line
@@ -263,25 +263,21 @@ static struct task_struct *pick_next_highest_task_rt(struct rq *rq, 


static DEFINE_PER_CPU(cpumask_t, local_cpu_mask);



/* Will lock the rq it finds */

static struct rq *find_lock_lowest_rq(struct task_struct *task,

				      struct rq *this_rq)

static int find_lowest_rq(struct task_struct *task)

{

	struct rq *lowest_rq = NULL;

	int cpu;

	int tries;

	cpumask_t *cpu_mask = &__get_cpu_var(local_cpu_mask);

	struct rq *lowest_rq = NULL;



	cpus_and(*cpu_mask, cpu_online_map, task->cpus_allowed);



	for (tries = 0; tries < RT_MAX_TRIES; tries++) {

	/*

	 * Scan each rq for the lowest prio.

	 */

	for_each_cpu_mask(cpu, *cpu_mask) {

			struct rq *rq = &per_cpu(runqueues, cpu);

		struct rq *rq = cpu_rq(cpu);



			if (cpu == this_rq->cpu)

		if (cpu == rq->cpu)

			continue;



		/* We look for lowest RT prio or non-rt CPU */
@@ -297,20 +293,36 @@ static struct rq *find_lock_lowest_rq(struct task_struct *task, 
		}

	}



		if (!lowest_rq)

	return lowest_rq ? lowest_rq->cpu : -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 cpu;

	int tries;



	for (tries = 0; tries < RT_MAX_TRIES; tries++) {

		cpu = find_lowest_rq(task);



		if (cpu == -1)

			break;



		lowest_rq = cpu_rq(cpu);



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

		if (double_lock_balance(this_rq, lowest_rq)) {

		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) != this_rq ||

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

				     !cpu_isset(lowest_rq->cpu, task->cpus_allowed) ||

				     task_running(this_rq, task) ||

				     task_running(rq, task) ||

				     !task->se.on_rq)) {

				spin_unlock(&lowest_rq->lock);

				lowest_rq = NULL;