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-rw-r--r--kernel/sched_rt.c83
1 files changed, 60 insertions, 23 deletions
diff --git a/kernel/sched_rt.c b/kernel/sched_rt.c
index e7cebdc65f8..64b2a37c07d 100644
--- a/kernel/sched_rt.c
+++ b/kernel/sched_rt.c
@@ -183,6 +183,14 @@ static inline u64 sched_rt_period(struct rt_rq *rt_rq)
return ktime_to_ns(rt_rq->tg->rt_bandwidth.rt_period);
}
+typedef struct task_group *rt_rq_iter_t;
+
+#define for_each_rt_rq(rt_rq, iter, rq) \
+ for (iter = list_entry_rcu(task_groups.next, typeof(*iter), list); \
+ (&iter->list != &task_groups) && \
+ (rt_rq = iter->rt_rq[cpu_of(rq)]); \
+ iter = list_entry_rcu(iter->list.next, typeof(*iter), list))
+
static inline void list_add_leaf_rt_rq(struct rt_rq *rt_rq)
{
list_add_rcu(&rt_rq->leaf_rt_rq_list,
@@ -288,6 +296,11 @@ static inline u64 sched_rt_period(struct rt_rq *rt_rq)
return ktime_to_ns(def_rt_bandwidth.rt_period);
}
+typedef struct rt_rq *rt_rq_iter_t;
+
+#define for_each_rt_rq(rt_rq, iter, rq) \
+ for ((void) iter, rt_rq = &rq->rt; rt_rq; rt_rq = NULL)
+
static inline void list_add_leaf_rt_rq(struct rt_rq *rt_rq)
{
}
@@ -402,12 +415,13 @@ next:
static void __disable_runtime(struct rq *rq)
{
struct root_domain *rd = rq->rd;
+ rt_rq_iter_t iter;
struct rt_rq *rt_rq;
if (unlikely(!scheduler_running))
return;
- for_each_leaf_rt_rq(rt_rq, rq) {
+ for_each_rt_rq(rt_rq, iter, rq) {
struct rt_bandwidth *rt_b = sched_rt_bandwidth(rt_rq);
s64 want;
int i;
@@ -487,6 +501,7 @@ static void disable_runtime(struct rq *rq)
static void __enable_runtime(struct rq *rq)
{
+ rt_rq_iter_t iter;
struct rt_rq *rt_rq;
if (unlikely(!scheduler_running))
@@ -495,7 +510,7 @@ static void __enable_runtime(struct rq *rq)
/*
* Reset each runqueue's bandwidth settings
*/
- for_each_leaf_rt_rq(rt_rq, rq) {
+ for_each_rt_rq(rt_rq, iter, rq) {
struct rt_bandwidth *rt_b = sched_rt_bandwidth(rt_rq);
raw_spin_lock(&rt_b->rt_runtime_lock);
@@ -562,6 +577,13 @@ static int do_sched_rt_period_timer(struct rt_bandwidth *rt_b, int overrun)
if (rt_rq->rt_throttled && rt_rq->rt_time < runtime) {
rt_rq->rt_throttled = 0;
enqueue = 1;
+
+ /*
+ * Force a clock update if the CPU was idle,
+ * lest wakeup -> unthrottle time accumulate.
+ */
+ if (rt_rq->rt_nr_running && rq->curr == rq->idle)
+ rq->skip_clock_update = -1;
}
if (rt_rq->rt_time || rt_rq->rt_nr_running)
idle = 0;
@@ -977,13 +999,23 @@ static void yield_task_rt(struct rq *rq)
static int find_lowest_rq(struct task_struct *task);
static int
-select_task_rq_rt(struct rq *rq, struct task_struct *p, int sd_flag, int flags)
+select_task_rq_rt(struct task_struct *p, int sd_flag, int flags)
{
+ struct task_struct *curr;
+ struct rq *rq;
+ int cpu;
+
if (sd_flag != SD_BALANCE_WAKE)
return smp_processor_id();
+ cpu = task_cpu(p);
+ rq = cpu_rq(cpu);
+
+ rcu_read_lock();
+ curr = ACCESS_ONCE(rq->curr); /* unlocked access */
+
/*
- * If the current task is an RT task, then
+ * If the current task on @p's runqueue is an RT task, then
* try to see if we can wake this RT task up on another
* runqueue. Otherwise simply start this RT task
* on its current runqueue.
@@ -997,21 +1029,25 @@ select_task_rq_rt(struct rq *rq, struct task_struct *p, int sd_flag, int flags)
* lock?
*
* For equal prio tasks, we just let the scheduler sort it out.
+ *
+ * Otherwise, just let it ride on the affined RQ and the
+ * post-schedule router will push the preempted task away
+ *
+ * This test is optimistic, if we get it wrong the load-balancer
+ * will have to sort it out.
*/
- if (unlikely(rt_task(rq->curr)) &&
- (rq->curr->rt.nr_cpus_allowed < 2 ||
- rq->curr->prio < p->prio) &&
+ if (curr && unlikely(rt_task(curr)) &&
+ (curr->rt.nr_cpus_allowed < 2 ||
+ curr->prio < p->prio) &&
(p->rt.nr_cpus_allowed > 1)) {
- int cpu = find_lowest_rq(p);
+ int target = find_lowest_rq(p);
- return (cpu == -1) ? task_cpu(p) : cpu;
+ if (target != -1)
+ cpu = target;
}
+ rcu_read_unlock();
- /*
- * Otherwise, just let it ride on the affined RQ and the
- * post-schedule router will push the preempted task away
- */
- return task_cpu(p);
+ return cpu;
}
static void check_preempt_equal_prio(struct rq *rq, struct task_struct *p)
@@ -1136,7 +1172,7 @@ static void put_prev_task_rt(struct rq *rq, struct task_struct *p)
* The previous task needs to be made eligible for pushing
* if it is still active
*/
- if (p->se.on_rq && p->rt.nr_cpus_allowed > 1)
+ if (on_rt_rq(&p->rt) && p->rt.nr_cpus_allowed > 1)
enqueue_pushable_task(rq, p);
}
@@ -1287,7 +1323,7 @@ static struct rq *find_lock_lowest_rq(struct task_struct *task, struct rq *rq)
!cpumask_test_cpu(lowest_rq->cpu,
&task->cpus_allowed) ||
task_running(rq, task) ||
- !task->se.on_rq)) {
+ !task->on_rq)) {
raw_spin_unlock(&lowest_rq->lock);
lowest_rq = NULL;
@@ -1321,7 +1357,7 @@ static struct task_struct *pick_next_pushable_task(struct rq *rq)
BUG_ON(task_current(rq, p));
BUG_ON(p->rt.nr_cpus_allowed <= 1);
- BUG_ON(!p->se.on_rq);
+ BUG_ON(!p->on_rq);
BUG_ON(!rt_task(p));
return p;
@@ -1467,7 +1503,7 @@ static int pull_rt_task(struct rq *this_rq)
*/
if (p && (p->prio < this_rq->rt.highest_prio.curr)) {
WARN_ON(p == src_rq->curr);
- WARN_ON(!p->se.on_rq);
+ WARN_ON(!p->on_rq);
/*
* There's a chance that p is higher in priority
@@ -1538,7 +1574,7 @@ static void set_cpus_allowed_rt(struct task_struct *p,
* Update the migration status of the RQ if we have an RT task
* which is running AND changing its weight value.
*/
- if (p->se.on_rq && (weight != p->rt.nr_cpus_allowed)) {
+ if (p->on_rq && (weight != p->rt.nr_cpus_allowed)) {
struct rq *rq = task_rq(p);
if (!task_current(rq, p)) {
@@ -1608,7 +1644,7 @@ static void switched_from_rt(struct rq *rq, struct task_struct *p)
* we may need to handle the pulling of RT tasks
* now.
*/
- if (p->se.on_rq && !rq->rt.rt_nr_running)
+ if (p->on_rq && !rq->rt.rt_nr_running)
pull_rt_task(rq);
}
@@ -1638,7 +1674,7 @@ static void switched_to_rt(struct rq *rq, struct task_struct *p)
* If that current running task is also an RT task
* then see if we can move to another run queue.
*/
- if (p->se.on_rq && rq->curr != p) {
+ if (p->on_rq && rq->curr != p) {
#ifdef CONFIG_SMP
if (rq->rt.overloaded && push_rt_task(rq) &&
/* Don't resched if we changed runqueues */
@@ -1657,7 +1693,7 @@ static void switched_to_rt(struct rq *rq, struct task_struct *p)
static void
prio_changed_rt(struct rq *rq, struct task_struct *p, int oldprio)
{
- if (!p->se.on_rq)
+ if (!p->on_rq)
return;
if (rq->curr == p) {
@@ -1796,10 +1832,11 @@ extern void print_rt_rq(struct seq_file *m, int cpu, struct rt_rq *rt_rq);
static void print_rt_stats(struct seq_file *m, int cpu)
{
+ rt_rq_iter_t iter;
struct rt_rq *rt_rq;
rcu_read_lock();
- for_each_leaf_rt_rq(rt_rq, cpu_rq(cpu))
+ for_each_rt_rq(rt_rq, iter, cpu_rq(cpu))
print_rt_rq(m, cpu, rt_rq);
rcu_read_unlock();
}
generated by cgit v1.2.3-70-g09d2 (git 2.46.0) at 2024-11-11 03:55:06 +0000