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authorPeter Zijlstra <a.p.zijlstra@chello.nl>2008-06-19 09:06:57 +0200
committerIngo Molnar <mingo@elte.hu>2008-06-19 09:06:57 +0200
commitad2a3f13b7258a5daaaeb8cff9f835aac468b71d (patch)
treeac9ea87be655aba0a372b6b4a25215547da0e291
parent7ea56616ba6b3d67a4892728182e38ae162ea3e7 (diff)
downloadconfigs-ad2a3f13b7258a5daaaeb8cff9f835aac468b71d.tar.gz
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>
-rw-r--r--kernel/sched_rt.c59
1 files changed, 33 insertions, 26 deletions
diff --git a/kernel/sched_rt.c b/kernel/sched_rt.c
index 3432d573205..837241568d7 100644
--- a/kernel/sched_rt.c
+++ b/kernel/sched_rt.c
@@ -449,13 +449,19 @@ void dec_rt_tasks(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq)
#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_prio_array *array = &rt_rq->active;
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;
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);
}
-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_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
* 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) {
rt_se->back = back;
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) {
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)
rt_se->timeout = 0;
- dequeue_rt_stack(p);
-
- /*
- * enqueue everybody, bottom - up.
- */
- for_each_sched_rt_entity(rt_se)
- enqueue_rt_entity(rt_se);
+ enqueue_rt_entity(rt_se);
}
static void dequeue_task_rt(struct rq *rq, struct task_struct *p, int sleep)
{
struct sched_rt_entity *rt_se = &p->rt;
- struct rt_rq *rt_rq;
update_curr_rt(rq);
-
- 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);
- }
+ dequeue_rt_entity(rt_se);
}
/*