sched: rt-group: heirarchy aware throttle

The bandwidth throttle code dequeues a group when it runs out of quota, and
re-queues it once the period rolls over and the quota gets refreshed.

Sadly it failed to take the hierarchy into consideration. Share more of the
enqueue/dequeue code with regular task opterations.

Also, some operations like sched_setscheduler() can dequeue/enqueue tasks that
are in throttled runqueues, we should not inadvertly re-enqueue empty runqueues
so check for that.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Tested-by: Daniel K. <dk@uw.no>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This commit is contained in:
Peter Zijlstra 2008-06-19 09:06:57 +02:00 committed by Ingo Molnar
parent 7ea56616ba
commit ad2a3f13b7

View file

@ -449,13 +449,19 @@ void dec_rt_tasks(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq)
#endif #endif
} }
static void enqueue_rt_entity(struct sched_rt_entity *rt_se) static void __enqueue_rt_entity(struct sched_rt_entity *rt_se)
{ {
struct rt_rq *rt_rq = rt_rq_of_se(rt_se); struct rt_rq *rt_rq = rt_rq_of_se(rt_se);
struct rt_prio_array *array = &rt_rq->active; struct rt_prio_array *array = &rt_rq->active;
struct rt_rq *group_rq = group_rt_rq(rt_se); struct rt_rq *group_rq = group_rt_rq(rt_se);
if (group_rq && rt_rq_throttled(group_rq)) /*
* 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; return;
list_add_tail(&rt_se->run_list, array->queue + rt_se_prio(rt_se)); list_add_tail(&rt_se->run_list, array->queue + rt_se_prio(rt_se));
@ -464,7 +470,7 @@ static void enqueue_rt_entity(struct sched_rt_entity *rt_se)
inc_rt_tasks(rt_se, rt_rq); inc_rt_tasks(rt_se, rt_rq);
} }
static void dequeue_rt_entity(struct sched_rt_entity *rt_se) static void __dequeue_rt_entity(struct sched_rt_entity *rt_se)
{ {
struct rt_rq *rt_rq = rt_rq_of_se(rt_se); struct rt_rq *rt_rq = rt_rq_of_se(rt_se);
struct rt_prio_array *array = &rt_rq->active; struct rt_prio_array *array = &rt_rq->active;
@ -480,11 +486,10 @@ static void dequeue_rt_entity(struct sched_rt_entity *rt_se)
* Because the prio of an upper entry depends on the lower * Because the prio of an upper entry depends on the lower
* entries, we must remove entries top - down. * entries, we must remove entries top - down.
*/ */
static void dequeue_rt_stack(struct task_struct *p) static void dequeue_rt_stack(struct sched_rt_entity *rt_se)
{ {
struct sched_rt_entity *rt_se, *back = NULL; struct sched_rt_entity *back = NULL;
rt_se = &p->rt;
for_each_sched_rt_entity(rt_se) { for_each_sched_rt_entity(rt_se) {
rt_se->back = back; rt_se->back = back;
back = rt_se; back = rt_se;
@ -492,7 +497,26 @@ static void dequeue_rt_stack(struct task_struct *p)
for (rt_se = back; rt_se; rt_se = rt_se->back) { for (rt_se = back; rt_se; rt_se = rt_se->back) {
if (on_rt_rq(rt_se)) if (on_rt_rq(rt_se))
dequeue_rt_entity(rt_se); __dequeue_rt_entity(rt_se);
}
}
static void enqueue_rt_entity(struct sched_rt_entity *rt_se)
{
dequeue_rt_stack(rt_se);
for_each_sched_rt_entity(rt_se)
__enqueue_rt_entity(rt_se);
}
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);
} }
} }
@ -506,32 +530,15 @@ static void enqueue_task_rt(struct rq *rq, struct task_struct *p, int wakeup)
if (wakeup) if (wakeup)
rt_se->timeout = 0; rt_se->timeout = 0;
dequeue_rt_stack(p); enqueue_rt_entity(rt_se);
/*
* enqueue everybody, bottom - up.
*/
for_each_sched_rt_entity(rt_se)
enqueue_rt_entity(rt_se);
} }
static void dequeue_task_rt(struct rq *rq, struct task_struct *p, int sleep) static void dequeue_task_rt(struct rq *rq, struct task_struct *p, int sleep)
{ {
struct sched_rt_entity *rt_se = &p->rt; struct sched_rt_entity *rt_se = &p->rt;
struct rt_rq *rt_rq;
update_curr_rt(rq); update_curr_rt(rq);
dequeue_rt_entity(rt_se);
dequeue_rt_stack(p);
/*
* re-enqueue all non-empty rt_rq entities.
*/
for_each_sched_rt_entity(rt_se) {
rt_rq = group_rt_rq(rt_se);
if (rt_rq && rt_rq->rt_nr_running)
enqueue_rt_entity(rt_se);
}
} }
/* /*