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-rw-r--r--kernel/sched/rt.c127
1 files changed, 102 insertions, 25 deletions
diff --git a/kernel/sched/rt.c b/kernel/sched/rt.c
index bd2267ad404f..b3512f1afce9 100644
--- a/kernel/sched/rt.c
+++ b/kernel/sched/rt.c
@@ -79,6 +79,8 @@ void init_rt_rq(struct rt_rq *rt_rq, struct rq *rq)
rt_rq->overloaded = 0;
plist_head_init(&rt_rq->pushable_tasks);
#endif
+ /* We start is dequeued state, because no RT tasks are queued */
+ rt_rq->rt_queued = 0;
rt_rq->rt_time = 0;
rt_rq->rt_throttled = 0;
@@ -112,6 +114,13 @@ static inline struct rt_rq *rt_rq_of_se(struct sched_rt_entity *rt_se)
return rt_se->rt_rq;
}
+static inline struct rq *rq_of_rt_se(struct sched_rt_entity *rt_se)
+{
+ struct rt_rq *rt_rq = rt_se->rt_rq;
+
+ return rt_rq->rq;
+}
+
void free_rt_sched_group(struct task_group *tg)
{
int i;
@@ -211,10 +220,16 @@ static inline struct rq *rq_of_rt_rq(struct rt_rq *rt_rq)
return container_of(rt_rq, struct rq, rt);
}
-static inline struct rt_rq *rt_rq_of_se(struct sched_rt_entity *rt_se)
+static inline struct rq *rq_of_rt_se(struct sched_rt_entity *rt_se)
{
struct task_struct *p = rt_task_of(rt_se);
- struct rq *rq = task_rq(p);
+
+ return task_rq(p);
+}
+
+static inline struct rt_rq *rt_rq_of_se(struct sched_rt_entity *rt_se)
+{
+ struct rq *rq = rq_of_rt_se(rt_se);
return &rq->rt;
}
@@ -391,6 +406,9 @@ static inline void set_post_schedule(struct rq *rq)
}
#endif /* CONFIG_SMP */
+static void enqueue_top_rt_rq(struct rt_rq *rt_rq);
+static void dequeue_top_rt_rq(struct rt_rq *rt_rq);
+
static inline int on_rt_rq(struct sched_rt_entity *rt_se)
{
return !list_empty(&rt_se->run_list);
@@ -452,8 +470,11 @@ static void sched_rt_rq_enqueue(struct rt_rq *rt_rq)
rt_se = rt_rq->tg->rt_se[cpu];
if (rt_rq->rt_nr_running) {
- if (rt_se && !on_rt_rq(rt_se))
+ if (!rt_se)
+ enqueue_top_rt_rq(rt_rq);
+ else if (!on_rt_rq(rt_se))
enqueue_rt_entity(rt_se, false);
+
if (rt_rq->highest_prio.curr < curr->prio)
resched_task(curr);
}
@@ -466,10 +487,17 @@ static void sched_rt_rq_dequeue(struct rt_rq *rt_rq)
rt_se = rt_rq->tg->rt_se[cpu];
- if (rt_se && on_rt_rq(rt_se))
+ if (!rt_se)
+ dequeue_top_rt_rq(rt_rq);
+ else if (on_rt_rq(rt_se))
dequeue_rt_entity(rt_se);
}
+static inline int rt_rq_throttled(struct rt_rq *rt_rq)
+{
+ return rt_rq->rt_throttled && !rt_rq->rt_nr_boosted;
+}
+
static int rt_se_boosted(struct sched_rt_entity *rt_se)
{
struct rt_rq *rt_rq = group_rt_rq(rt_se);
@@ -532,12 +560,23 @@ static inline struct rt_rq *group_rt_rq(struct sched_rt_entity *rt_se)
static inline void sched_rt_rq_enqueue(struct rt_rq *rt_rq)
{
- if (rt_rq->rt_nr_running)
- resched_task(rq_of_rt_rq(rt_rq)->curr);
+ struct rq *rq = rq_of_rt_rq(rt_rq);
+
+ if (!rt_rq->rt_nr_running)
+ return;
+
+ enqueue_top_rt_rq(rt_rq);
+ resched_task(rq->curr);
}
static inline void sched_rt_rq_dequeue(struct rt_rq *rt_rq)
{
+ dequeue_top_rt_rq(rt_rq);
+}
+
+static inline int rt_rq_throttled(struct rt_rq *rt_rq)
+{
+ return rt_rq->rt_throttled;
}
static inline const struct cpumask *sched_rt_period_mask(void)
@@ -851,14 +890,8 @@ static int sched_rt_runtime_exceeded(struct rt_rq *rt_rq)
* but accrue some time due to boosting.
*/
if (likely(rt_b->rt_runtime)) {
- static bool once = false;
-
rt_rq->rt_throttled = 1;
-
- if (!once) {
- once = true;
- printk_sched("sched: RT throttling activated\n");
- }
+ printk_deferred_once("sched: RT throttling activated\n");
} else {
/*
* In case we did anyway, make it go away,
@@ -922,6 +955,38 @@ static void update_curr_rt(struct rq *rq)
}
}
+static void
+dequeue_top_rt_rq(struct rt_rq *rt_rq)
+{
+ struct rq *rq = rq_of_rt_rq(rt_rq);
+
+ BUG_ON(&rq->rt != rt_rq);
+
+ if (!rt_rq->rt_queued)
+ return;
+
+ BUG_ON(!rq->nr_running);
+
+ sub_nr_running(rq, rt_rq->rt_nr_running);
+ rt_rq->rt_queued = 0;
+}
+
+static void
+enqueue_top_rt_rq(struct rt_rq *rt_rq)
+{
+ struct rq *rq = rq_of_rt_rq(rt_rq);
+
+ BUG_ON(&rq->rt != rt_rq);
+
+ if (rt_rq->rt_queued)
+ return;
+ if (rt_rq_throttled(rt_rq) || !rt_rq->rt_nr_running)
+ return;
+
+ add_nr_running(rq, rt_rq->rt_nr_running);
+ rt_rq->rt_queued = 1;
+}
+
#if defined CONFIG_SMP
static void
@@ -1045,12 +1110,23 @@ void dec_rt_group(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq) {}
#endif /* CONFIG_RT_GROUP_SCHED */
static inline
+unsigned int rt_se_nr_running(struct sched_rt_entity *rt_se)
+{
+ struct rt_rq *group_rq = group_rt_rq(rt_se);
+
+ if (group_rq)
+ return group_rq->rt_nr_running;
+ else
+ return 1;
+}
+
+static inline
void inc_rt_tasks(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq)
{
int prio = rt_se_prio(rt_se);
WARN_ON(!rt_prio(prio));
- rt_rq->rt_nr_running++;
+ rt_rq->rt_nr_running += rt_se_nr_running(rt_se);
inc_rt_prio(rt_rq, prio);
inc_rt_migration(rt_se, rt_rq);
@@ -1062,7 +1138,7 @@ void dec_rt_tasks(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq)
{
WARN_ON(!rt_prio(rt_se_prio(rt_se)));
WARN_ON(!rt_rq->rt_nr_running);
- rt_rq->rt_nr_running--;
+ rt_rq->rt_nr_running -= rt_se_nr_running(rt_se);
dec_rt_prio(rt_rq, rt_se_prio(rt_se));
dec_rt_migration(rt_se, rt_rq);
@@ -1119,6 +1195,8 @@ static void dequeue_rt_stack(struct sched_rt_entity *rt_se)
back = rt_se;
}
+ dequeue_top_rt_rq(rt_rq_of_se(back));
+
for (rt_se = back; rt_se; rt_se = rt_se->back) {
if (on_rt_rq(rt_se))
__dequeue_rt_entity(rt_se);
@@ -1127,13 +1205,18 @@ static void dequeue_rt_stack(struct sched_rt_entity *rt_se)
static void enqueue_rt_entity(struct sched_rt_entity *rt_se, bool head)
{
+ struct rq *rq = rq_of_rt_se(rt_se);
+
dequeue_rt_stack(rt_se);
for_each_sched_rt_entity(rt_se)
__enqueue_rt_entity(rt_se, head);
+ enqueue_top_rt_rq(&rq->rt);
}
static void dequeue_rt_entity(struct sched_rt_entity *rt_se)
{
+ struct rq *rq = rq_of_rt_se(rt_se);
+
dequeue_rt_stack(rt_se);
for_each_sched_rt_entity(rt_se) {
@@ -1142,6 +1225,7 @@ static void dequeue_rt_entity(struct sched_rt_entity *rt_se)
if (rt_rq && rt_rq->rt_nr_running)
__enqueue_rt_entity(rt_se, false);
}
+ enqueue_top_rt_rq(&rq->rt);
}
/*
@@ -1159,8 +1243,6 @@ enqueue_task_rt(struct rq *rq, struct task_struct *p, int flags)
if (!task_current(rq, p) && p->nr_cpus_allowed > 1)
enqueue_pushable_task(rq, p);
-
- inc_nr_running(rq);
}
static void dequeue_task_rt(struct rq *rq, struct task_struct *p, int flags)
@@ -1171,8 +1253,6 @@ static void dequeue_task_rt(struct rq *rq, struct task_struct *p, int flags)
dequeue_rt_entity(rt_se);
dequeue_pushable_task(rq, p);
-
- dec_nr_running(rq);
}
/*
@@ -1377,10 +1457,7 @@ pick_next_task_rt(struct rq *rq, struct task_struct *prev)
if (prev->sched_class == &rt_sched_class)
update_curr_rt(rq);
- if (!rt_rq->rt_nr_running)
- return NULL;
-
- if (rt_rq_throttled(rt_rq))
+ if (!rt_rq->rt_queued)
return NULL;
put_prev_task(rq, prev);
@@ -1892,9 +1969,9 @@ static void switched_to_rt(struct rq *rq, struct task_struct *p)
*/
if (p->on_rq && rq->curr != p) {
#ifdef CONFIG_SMP
- if (rq->rt.overloaded && push_rt_task(rq) &&
+ if (p->nr_cpus_allowed > 1 && rq->rt.overloaded &&
/* Don't resched if we changed runqueues */
- rq != task_rq(p))
+ push_rt_task(rq) && rq != task_rq(p))
check_resched = 0;
#endif /* CONFIG_SMP */
if (check_resched && p->prio < rq->curr->prio)