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-rw-r--r--kernel/sched/core.c84
1 files changed, 63 insertions, 21 deletions
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index bb5e7fd25354..6f488072e2fd 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -144,7 +144,7 @@ static inline bool __sched_core_less(struct task_struct *a, struct task_struct *
return false;
/* flip prio, so high prio is leftmost */
- if (prio_less(b, a, task_rq(a)->core->core_forceidle))
+ if (prio_less(b, a, !!task_rq(a)->core->core_forceidle_count))
return true;
return false;
@@ -181,15 +181,23 @@ void sched_core_enqueue(struct rq *rq, struct task_struct *p)
rb_add(&p->core_node, &rq->core_tree, rb_sched_core_less);
}
-void sched_core_dequeue(struct rq *rq, struct task_struct *p)
+void sched_core_dequeue(struct rq *rq, struct task_struct *p, int flags)
{
rq->core->core_task_seq++;
- if (!sched_core_enqueued(p))
- return;
+ if (sched_core_enqueued(p)) {
+ rb_erase(&p->core_node, &rq->core_tree);
+ RB_CLEAR_NODE(&p->core_node);
+ }
- rb_erase(&p->core_node, &rq->core_tree);
- RB_CLEAR_NODE(&p->core_node);
+ /*
+ * Migrating the last task off the cpu, with the cpu in forced idle
+ * state. Reschedule to create an accounting edge for forced idle,
+ * and re-examine whether the core is still in forced idle state.
+ */
+ if (!(flags & DEQUEUE_SAVE) && rq->nr_running == 1 &&
+ rq->core->core_forceidle_count && rq->curr == rq->idle)
+ resched_curr(rq);
}
/*
@@ -280,6 +288,8 @@ static void __sched_core_flip(bool enabled)
for_each_cpu(t, smt_mask)
cpu_rq(t)->core_enabled = enabled;
+ cpu_rq(cpu)->core->core_forceidle_start = 0;
+
sched_core_unlock(cpu, &flags);
cpumask_andnot(&sched_core_mask, &sched_core_mask, smt_mask);
@@ -364,7 +374,8 @@ void sched_core_put(void)
#else /* !CONFIG_SCHED_CORE */
static inline void sched_core_enqueue(struct rq *rq, struct task_struct *p) { }
-static inline void sched_core_dequeue(struct rq *rq, struct task_struct *p) { }
+static inline void
+sched_core_dequeue(struct rq *rq, struct task_struct *p, int flags) { }
#endif /* CONFIG_SCHED_CORE */
@@ -2005,7 +2016,7 @@ static inline void enqueue_task(struct rq *rq, struct task_struct *p, int flags)
static inline void dequeue_task(struct rq *rq, struct task_struct *p, int flags)
{
if (sched_core_enabled(rq))
- sched_core_dequeue(rq, p);
+ sched_core_dequeue(rq, p, flags);
if (!(flags & DEQUEUE_NOCLOCK))
update_rq_clock(rq);
@@ -5244,6 +5255,7 @@ void scheduler_tick(void)
if (sched_feat(LATENCY_WARN))
resched_latency = cpu_resched_latency(rq);
calc_global_load_tick(rq);
+ sched_core_tick(rq);
rq_unlock(rq, &rf);
@@ -5656,6 +5668,7 @@ pick_next_task(struct rq *rq, struct task_struct *prev, struct rq_flags *rf)
struct task_struct *next, *p, *max = NULL;
const struct cpumask *smt_mask;
bool fi_before = false;
+ bool core_clock_updated = (rq == rq->core);
unsigned long cookie;
int i, cpu, occ = 0;
struct rq *rq_i;
@@ -5708,10 +5721,18 @@ pick_next_task(struct rq *rq, struct task_struct *prev, struct rq_flags *rf)
/* reset state */
rq->core->core_cookie = 0UL;
- if (rq->core->core_forceidle) {
+ if (rq->core->core_forceidle_count) {
+ if (!core_clock_updated) {
+ update_rq_clock(rq->core);
+ core_clock_updated = true;
+ }
+ sched_core_account_forceidle(rq);
+ /* reset after accounting force idle */
+ rq->core->core_forceidle_start = 0;
+ rq->core->core_forceidle_count = 0;
+ rq->core->core_forceidle_occupation = 0;
need_sync = true;
fi_before = true;
- rq->core->core_forceidle = false;
}
/*
@@ -5753,7 +5774,12 @@ pick_next_task(struct rq *rq, struct task_struct *prev, struct rq_flags *rf)
for_each_cpu_wrap(i, smt_mask, cpu) {
rq_i = cpu_rq(i);
- if (i != cpu)
+ /*
+ * Current cpu always has its clock updated on entrance to
+ * pick_next_task(). If the current cpu is not the core,
+ * the core may also have been updated above.
+ */
+ if (i != cpu && (rq_i != rq->core || !core_clock_updated))
update_rq_clock(rq_i);
p = rq_i->core_pick = pick_task(rq_i);
@@ -5783,7 +5809,7 @@ pick_next_task(struct rq *rq, struct task_struct *prev, struct rq_flags *rf)
if (p == rq_i->idle) {
if (rq_i->nr_running) {
- rq->core->core_forceidle = true;
+ rq->core->core_forceidle_count++;
if (!fi_before)
rq->core->core_forceidle_seq++;
}
@@ -5792,6 +5818,12 @@ pick_next_task(struct rq *rq, struct task_struct *prev, struct rq_flags *rf)
}
}
+ if (schedstat_enabled() && rq->core->core_forceidle_count) {
+ if (cookie)
+ rq->core->core_forceidle_start = rq_clock(rq->core);
+ rq->core->core_forceidle_occupation = occ;
+ }
+
rq->core->core_pick_seq = rq->core->core_task_seq;
next = rq->core_pick;
rq->core_sched_seq = rq->core->core_pick_seq;
@@ -5828,8 +5860,8 @@ pick_next_task(struct rq *rq, struct task_struct *prev, struct rq_flags *rf)
* 1 0 1
* 1 1 0
*/
- if (!(fi_before && rq->core->core_forceidle))
- task_vruntime_update(rq_i, rq_i->core_pick, rq->core->core_forceidle);
+ if (!(fi_before && rq->core->core_forceidle_count))
+ task_vruntime_update(rq_i, rq_i->core_pick, !!rq->core->core_forceidle_count);
rq_i->core_pick->core_occupation = occ;
@@ -6033,11 +6065,19 @@ static void sched_core_cpu_deactivate(unsigned int cpu)
goto unlock;
/* copy the shared state to the new leader */
- core_rq->core_task_seq = rq->core_task_seq;
- core_rq->core_pick_seq = rq->core_pick_seq;
- core_rq->core_cookie = rq->core_cookie;
- core_rq->core_forceidle = rq->core_forceidle;
- core_rq->core_forceidle_seq = rq->core_forceidle_seq;
+ core_rq->core_task_seq = rq->core_task_seq;
+ core_rq->core_pick_seq = rq->core_pick_seq;
+ core_rq->core_cookie = rq->core_cookie;
+ core_rq->core_forceidle_count = rq->core_forceidle_count;
+ core_rq->core_forceidle_seq = rq->core_forceidle_seq;
+ core_rq->core_forceidle_occupation = rq->core_forceidle_occupation;
+
+ /*
+ * Accounting edge for forced idle is handled in pick_next_task().
+ * Don't need another one here, since the hotplug thread shouldn't
+ * have a cookie.
+ */
+ core_rq->core_forceidle_start = 0;
/* install new leader */
for_each_cpu(t, smt_mask) {
@@ -7126,7 +7166,7 @@ unsigned long effective_cpu_util(int cpu, unsigned long util_cfs,
unsigned long sched_cpu_util(int cpu, unsigned long max)
{
- return effective_cpu_util(cpu, cpu_util_cfs(cpu_rq(cpu)), max,
+ return effective_cpu_util(cpu, cpu_util_cfs(cpu), max,
ENERGY_UTIL, NULL);
}
#endif /* CONFIG_SMP */
@@ -9409,7 +9449,9 @@ void __init sched_init(void)
rq->core_pick = NULL;
rq->core_enabled = 0;
rq->core_tree = RB_ROOT;
- rq->core_forceidle = false;
+ rq->core_forceidle_count = 0;
+ rq->core_forceidle_occupation = 0;
+ rq->core_forceidle_start = 0;
rq->core_cookie = 0UL;
#endif
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