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

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
......@@ -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;
......@@ -819,7 +819,10 @@ 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;
list_add_tail(&rt_se->run_list, queue);
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);
......@@ -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);
......
Markdown is supported
0% or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment