{
struct rt_bandwidth *rt_b =
container_of(timer, struct rt_bandwidth, rt_period_timer);
- ktime_t now;
- int overrun;
int idle = 0;
+ int overrun;
+ raw_spin_lock(&rt_b->rt_runtime_lock);
for (;;) {
- now = hrtimer_cb_get_time(timer);
- overrun = hrtimer_forward(timer, now, rt_b->rt_period);
-
+ overrun = hrtimer_forward_now(timer, rt_b->rt_period);
if (!overrun)
break;
+ raw_spin_unlock(&rt_b->rt_runtime_lock);
idle = do_sched_rt_period_timer(rt_b, overrun);
+ raw_spin_lock(&rt_b->rt_runtime_lock);
}
+ if (idle)
+ rt_b->rt_period_active = 0;
+ raw_spin_unlock(&rt_b->rt_runtime_lock);
return idle ? HRTIMER_NORESTART : HRTIMER_RESTART;
}
if (!rt_bandwidth_enabled() || rt_b->rt_runtime == RUNTIME_INF)
return;
- if (hrtimer_active(&rt_b->rt_period_timer))
- return;
-
raw_spin_lock(&rt_b->rt_runtime_lock);
- start_bandwidth_timer(&rt_b->rt_period_timer, rt_b->rt_period);
+ if (!rt_b->rt_period_active) {
+ rt_b->rt_period_active = 1;
+ hrtimer_forward_now(&rt_b->rt_period_timer, rt_b->rt_period);
+ hrtimer_start_expires(&rt_b->rt_period_timer, HRTIMER_MODE_ABS_PINNED);
+ }
raw_spin_unlock(&rt_b->rt_runtime_lock);
}
-#ifdef CONFIG_SMP
+#if defined(CONFIG_SMP) && defined(HAVE_RT_PUSH_IPI)
static void push_irq_work_func(struct irq_work *work);
#endif
#ifdef CONFIG_SMP
-static int pull_rt_task(struct rq *this_rq);
+static void pull_rt_task(struct rq *this_rq);
static inline bool need_pull_rt_task(struct rq *rq, struct task_struct *prev)
{
rt_rq = &rq_of_rt_rq(rt_rq)->rt;
rt_rq->rt_nr_total++;
- if (p->nr_cpus_allowed > 1)
+ if (tsk_nr_cpus_allowed(p) > 1)
rt_rq->rt_nr_migratory++;
update_rt_migration(rt_rq);
rt_rq = &rq_of_rt_rq(rt_rq)->rt;
rt_rq->rt_nr_total--;
- if (p->nr_cpus_allowed > 1)
+ if (tsk_nr_cpus_allowed(p) > 1)
rt_rq->rt_nr_migratory--;
update_rt_migration(rt_rq);
return !plist_head_empty(&rq->rt.pushable_tasks);
}
-static inline void set_post_schedule(struct rq *rq)
+static DEFINE_PER_CPU(struct callback_head, rt_push_head);
+static DEFINE_PER_CPU(struct callback_head, rt_pull_head);
+
+static void push_rt_tasks(struct rq *);
+static void pull_rt_task(struct rq *);
+
+static inline void queue_push_tasks(struct rq *rq)
{
- /*
- * We detect this state here so that we can avoid taking the RQ
- * lock again later if there is no need to push
- */
- rq->post_schedule = has_pushable_tasks(rq);
+ if (!has_pushable_tasks(rq))
+ return;
+
+ queue_balance_callback(rq, &per_cpu(rt_push_head, rq->cpu), push_rt_tasks);
+}
+
+static inline void queue_pull_task(struct rq *rq)
+{
+ queue_balance_callback(rq, &per_cpu(rt_pull_head, rq->cpu), pull_rt_task);
}
static void enqueue_pushable_task(struct rq *rq, struct task_struct *p)
return false;
}
-static inline int pull_rt_task(struct rq *this_rq)
+static inline void pull_rt_task(struct rq *this_rq)
{
- return 0;
}
-static inline void set_post_schedule(struct rq *rq)
+static inline void queue_push_tasks(struct rq *rq)
{
}
#endif /* CONFIG_SMP */
/*
* We ran out of runtime, see if we can borrow some from our neighbours.
*/
-static int do_balance_runtime(struct rt_rq *rt_rq)
+static void do_balance_runtime(struct rt_rq *rt_rq)
{
struct rt_bandwidth *rt_b = sched_rt_bandwidth(rt_rq);
struct root_domain *rd = rq_of_rt_rq(rt_rq)->rd;
- int i, weight, more = 0;
+ int i, weight;
u64 rt_period;
weight = cpumask_weight(rd->span);
diff = rt_period - rt_rq->rt_runtime;
iter->rt_runtime -= diff;
rt_rq->rt_runtime += diff;
- more = 1;
if (rt_rq->rt_runtime == rt_period) {
raw_spin_unlock(&iter->rt_runtime_lock);
break;
raw_spin_unlock(&iter->rt_runtime_lock);
}
raw_spin_unlock(&rt_b->rt_runtime_lock);
-
- return more;
}
/*
}
}
-static int balance_runtime(struct rt_rq *rt_rq)
+static void balance_runtime(struct rt_rq *rt_rq)
{
- int more = 0;
-
if (!sched_feat(RT_RUNTIME_SHARE))
- return more;
+ return;
if (rt_rq->rt_time > rt_rq->rt_runtime) {
raw_spin_unlock(&rt_rq->rt_runtime_lock);
- more = do_balance_runtime(rt_rq);
+ do_balance_runtime(rt_rq);
raw_spin_lock(&rt_rq->rt_runtime_lock);
}
-
- return more;
}
#else /* !CONFIG_SMP */
-static inline int balance_runtime(struct rt_rq *rt_rq)
-{
- return 0;
-}
+static inline void balance_runtime(struct rt_rq *rt_rq) {}
#endif /* CONFIG_SMP */
static int do_sched_rt_period_timer(struct rt_bandwidth *rt_b, int overrun)
enqueue_rt_entity(rt_se, flags & ENQUEUE_HEAD);
- if (!task_current(rq, p) && p->nr_cpus_allowed > 1)
+ if (!task_current(rq, p) && tsk_nr_cpus_allowed(p) > 1)
enqueue_pushable_task(rq, p);
}
rq = cpu_rq(cpu);
rcu_read_lock();
- curr = ACCESS_ONCE(rq->curr); /* unlocked access */
+ curr = READ_ONCE(rq->curr); /* unlocked access */
/*
* If the current task on @p's runqueue is an RT task, then
* will have to sort it out.
*/
if (curr && unlikely(rt_task(curr)) &&
- (curr->nr_cpus_allowed < 2 ||
+ (tsk_nr_cpus_allowed(curr) < 2 ||
curr->prio <= p->prio)) {
int target = find_lowest_rq(p);
* Current can't be migrated, useless to reschedule,
* let's hope p can move out.
*/
- if (rq->curr->nr_cpus_allowed == 1 ||
+ if (tsk_nr_cpus_allowed(rq->curr) == 1 ||
!cpupri_find(&rq->rd->cpupri, rq->curr, NULL))
return;
* p is migratable, so let's not schedule it and
* see if it is pushed or pulled somewhere else.
*/
- if (p->nr_cpus_allowed != 1
+ if (tsk_nr_cpus_allowed(p) != 1
&& cpupri_find(&rq->rd->cpupri, p, NULL))
return;
struct rt_rq *rt_rq = &rq->rt;
if (need_pull_rt_task(rq, prev)) {
+ /*
+ * This is OK, because current is on_cpu, which avoids it being
+ * picked for load-balance and preemption/IRQs are still
+ * disabled avoiding further scheduler activity on it and we're
+ * being very careful to re-start the picking loop.
+ */
+ lockdep_unpin_lock(&rq->lock);
pull_rt_task(rq);
+ lockdep_pin_lock(&rq->lock);
/*
* pull_rt_task() can drop (and re-acquire) rq->lock; this
* means a dl or stop task can slip in, in which case we need
/* The running task is never eligible for pushing */
dequeue_pushable_task(rq, p);
- set_post_schedule(rq);
+ queue_push_tasks(rq);
return p;
}
* The previous task needs to be made eligible for pushing
* if it is still active
*/
- if (on_rt_rq(&p->rt) && p->nr_cpus_allowed > 1)
+ if (on_rt_rq(&p->rt) && tsk_nr_cpus_allowed(p) > 1)
enqueue_pushable_task(rq, p);
}
if (unlikely(!lowest_mask))
return -1;
- if (task->nr_cpus_allowed == 1)
+ if (tsk_nr_cpus_allowed(task) == 1)
return -1; /* No other targets possible */
if (!cpupri_find(&task_rq(task)->rd->cpupri, task, lowest_mask))
BUG_ON(rq->cpu != task_cpu(p));
BUG_ON(task_current(rq, p));
- BUG_ON(p->nr_cpus_allowed <= 1);
+ BUG_ON(tsk_nr_cpus_allowed(p) <= 1);
BUG_ON(!task_on_rq_queued(p));
BUG_ON(!rt_task(p));
}
#endif /* HAVE_RT_PUSH_IPI */
-static int pull_rt_task(struct rq *this_rq)
+static void pull_rt_task(struct rq *this_rq)
{
- int this_cpu = this_rq->cpu, ret = 0, cpu;
+ int this_cpu = this_rq->cpu, cpu;
+ bool resched = false;
struct task_struct *p;
struct rq *src_rq;
if (likely(!rt_overloaded(this_rq)))
- return 0;
+ return;
/*
* Match the barrier from rt_set_overloaded; this guarantees that if we
#ifdef HAVE_RT_PUSH_IPI
if (sched_feat(RT_PUSH_IPI)) {
tell_cpu_to_push(this_rq);
- return 0;
+ return;
}
#endif
if (p->prio < src_rq->curr->prio)
goto skip;
- ret = 1;
+ resched = true;
deactivate_task(src_rq, p, 0);
set_task_cpu(p, this_cpu);
double_unlock_balance(this_rq, src_rq);
}
- return ret;
-}
-
-static void post_schedule_rt(struct rq *rq)
-{
- push_rt_tasks(rq);
+ if (resched)
+ resched_curr(this_rq);
}
/*
{
if (!task_running(rq, p) &&
!test_tsk_need_resched(rq->curr) &&
- has_pushable_tasks(rq) &&
- p->nr_cpus_allowed > 1 &&
+ tsk_nr_cpus_allowed(p) > 1 &&
(dl_task(rq->curr) || rt_task(rq->curr)) &&
- (rq->curr->nr_cpus_allowed < 2 ||
+ (tsk_nr_cpus_allowed(rq->curr) < 2 ||
rq->curr->prio <= p->prio))
push_rt_tasks(rq);
}
-static void set_cpus_allowed_rt(struct task_struct *p,
- const struct cpumask *new_mask)
-{
- struct rq *rq;
- int weight;
-
- BUG_ON(!rt_task(p));
-
- if (!task_on_rq_queued(p))
- return;
-
- weight = cpumask_weight(new_mask);
-
- /*
- * Only update if the process changes its state from whether it
- * can migrate or not.
- */
- if ((p->nr_cpus_allowed > 1) == (weight > 1))
- return;
-
- rq = task_rq(p);
-
- /*
- * The process used to be able to migrate OR it can now migrate
- */
- if (weight <= 1) {
- if (!task_current(rq, p))
- dequeue_pushable_task(rq, p);
- BUG_ON(!rq->rt.rt_nr_migratory);
- rq->rt.rt_nr_migratory--;
- } else {
- if (!task_current(rq, p))
- enqueue_pushable_task(rq, p);
- rq->rt.rt_nr_migratory++;
- }
-
- update_rt_migration(&rq->rt);
-}
-
/* Assumes rq->lock is held */
static void rq_online_rt(struct rq *rq)
{
if (!task_on_rq_queued(p) || rq->rt.rt_nr_running)
return;
- if (pull_rt_task(rq))
- resched_curr(rq);
+ queue_pull_task(rq);
}
void __init init_sched_rt_class(void)
*/
static void switched_to_rt(struct rq *rq, struct task_struct *p)
{
- int check_resched = 1;
-
/*
* If we are already running, then there's nothing
* that needs to be done. But if we are not running
*/
if (task_on_rq_queued(p) && rq->curr != p) {
#ifdef CONFIG_SMP
- if (p->nr_cpus_allowed > 1 && rq->rt.overloaded &&
- /* Don't resched if we changed runqueues */
- push_rt_task(rq) && rq != task_rq(p))
- check_resched = 0;
-#endif /* CONFIG_SMP */
- if (check_resched && p->prio < rq->curr->prio)
+ if (tsk_nr_cpus_allowed(p) > 1 && rq->rt.overloaded)
+ queue_push_tasks(rq);
+#else
+ if (p->prio < rq->curr->prio)
resched_curr(rq);
+#endif /* CONFIG_SMP */
}
}
* may need to pull tasks to this runqueue.
*/
if (oldprio < p->prio)
- pull_rt_task(rq);
+ queue_pull_task(rq);
+
/*
* If there's a higher priority task waiting to run
- * then reschedule. Note, the above pull_rt_task
- * can release the rq lock and p could migrate.
- * Only reschedule if p is still on the same runqueue.
+ * then reschedule.
*/
- if (p->prio > rq->rt.highest_prio.curr && rq->curr == p)
+ if (p->prio > rq->rt.highest_prio.curr)
resched_curr(rq);
#else
/* For UP simply resched on drop of prio */
#ifdef CONFIG_SMP
.select_task_rq = select_task_rq_rt,
- .set_cpus_allowed = set_cpus_allowed_rt,
+ .set_cpus_allowed = set_cpus_allowed_common,
.rq_online = rq_online_rt,
.rq_offline = rq_offline_rt,
- .post_schedule = post_schedule_rt,
.task_woken = task_woken_rt,
.switched_from = switched_from_rt,
#endif
Code Review / kvmfornfv.git / blobdiff