Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 37dad3fc authored by Thomas Gleixner's avatar Thomas Gleixner
Browse files

sched: Implement head queueing for sched_rt 



The ability of enqueueing a task to the head of a SCHED_FIFO priority
list is required to fix some violations of POSIX scheduling policy.

Implement the functionality in sched_rt.

Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Acked-by: default avatarPeter Zijlstra <peterz@infradead.org>
Tested-by: default avatarCarsten Emde <cbe@osadl.org>
Tested-by: default avatarMathias Weber <mathias.weber.mw1@roche.com>
LKML-Reference: <20100120171629.772169931@linutronix.de>
parent ea87bb78

kernel/sched_rt.c

+11 −8
Original line number Diff line number Diff line
@@ -194,7 +194,7 @@ 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);

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)
@@ -204,7 +204,7 @@ 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);

			enqueue_rt_entity(rt_se, false);

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

			resched_task(curr);

	}
@@ -803,7 +803,7 @@ void dec_rt_tasks(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq) 
	dec_rt_group(rt_se, rt_rq);

}



static void __enqueue_rt_entity(struct sched_rt_entity *rt_se)

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;
@@ -819,6 +819,9 @@ static void __enqueue_rt_entity(struct sched_rt_entity *rt_se) 
	if (group_rq && (rt_rq_throttled(group_rq) || !group_rq->rt_nr_running))

		return;



	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);
@@ -856,11 +859,11 @@ static void dequeue_rt_stack(struct sched_rt_entity *rt_se) 
	}

}



static void enqueue_rt_entity(struct sched_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);

		__enqueue_rt_entity(rt_se, head);

}



static void dequeue_rt_entity(struct sched_rt_entity *rt_se)
@@ -871,7 +874,7 @@ static void dequeue_rt_entity(struct 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);

			__enqueue_rt_entity(rt_se, false);

	}

}
@@ -886,7 +889,7 @@ enqueue_task_rt(struct rq *rq, struct task_struct *p, int wakeup, bool head) 
	if (wakeup)

		rt_se->timeout = 0;



	enqueue_rt_entity(rt_se);

	enqueue_rt_entity(rt_se, head);



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

		enqueue_pushable_task(rq, p);