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| author | Thomas Gleixner <tglx@linutronix.de> | 2010-01-20 20:59:01 +0000 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2010-01-22 18:09:59 +0100 |
| commit | 37dad3fce97f01e5149d69de0833d8452c0e862e (patch) | |
| tree | b61b32fd56301211e06c4ff8d7d72a08eb7af182 /kernel/sched_rt.c | |
| parent | ea87bb7853168434f4a82426dd1ea8421f9e604d (diff) | |
| download | lwn-37dad3fce97f01e5149d69de0833d8452c0e862e.tar.gz lwn-37dad3fce97f01e5149d69de0833d8452c0e862e.zip | |
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: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Tested-by: Carsten Emde <cbe@osadl.org>
Tested-by: Mathias Weber <mathias.weber.mw1@roche.com>
LKML-Reference: <20100120171629.772169931@linutronix.de>
Diffstat (limited to 'kernel/sched_rt.c')
| -rw-r--r-- | kernel/sched_rt.c | 19 |
1 files changed, 11 insertions, 8 deletions
diff --git a/kernel/sched_rt.c b/kernel/sched_rt.c index 38076dabb44a..ca49ceb01201 100644 --- a/kernel/sched_rt.c +++ b/kernel/sched_rt.c @@ -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); |