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-rw-r--r--kernel/sched/core.c59
1 files changed, 34 insertions, 25 deletions
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index e506d9de16fc..e45c1d21b371 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -111,7 +111,7 @@ static inline int __task_prio(struct task_struct *p)
*/
/* real prio, less is less */
-static inline bool prio_less(struct task_struct *a, struct task_struct *b)
+static inline bool prio_less(struct task_struct *a, struct task_struct *b, bool in_fi)
{
int pa = __task_prio(a), pb = __task_prio(b);
@@ -125,19 +125,8 @@ static inline bool prio_less(struct task_struct *a, struct task_struct *b)
if (pa == -1) /* dl_prio() doesn't work because of stop_class above */
return !dl_time_before(a->dl.deadline, b->dl.deadline);
- if (pa == MAX_RT_PRIO + MAX_NICE) { /* fair */
- u64 vruntime = b->se.vruntime;
-
- /*
- * Normalize the vruntime if tasks are in different cpus.
- */
- if (task_cpu(a) != task_cpu(b)) {
- vruntime -= task_cfs_rq(b)->min_vruntime;
- vruntime += task_cfs_rq(a)->min_vruntime;
- }
-
- return !((s64)(a->se.vruntime - vruntime) <= 0);
- }
+ if (pa == MAX_RT_PRIO + MAX_NICE) /* fair */
+ return cfs_prio_less(a, b, in_fi);
return false;
}
@@ -151,7 +140,7 @@ 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))
+ if (prio_less(b, a, task_rq(a)->core->core_forceidle))
return true;
return false;
@@ -5350,7 +5339,7 @@ static inline bool cookie_match(struct task_struct *a, struct task_struct *b)
* - Else returns idle_task.
*/
static struct task_struct *
-pick_task(struct rq *rq, const struct sched_class *class, struct task_struct *max)
+pick_task(struct rq *rq, const struct sched_class *class, struct task_struct *max, bool in_fi)
{
struct task_struct *class_pick, *cookie_pick;
unsigned long cookie = rq->core->core_cookie;
@@ -5365,7 +5354,7 @@ pick_task(struct rq *rq, const struct sched_class *class, struct task_struct *ma
* higher priority than max.
*/
if (max && class_pick->core_cookie &&
- prio_less(class_pick, max))
+ prio_less(class_pick, max, in_fi))
return idle_sched_class.pick_task(rq);
return class_pick;
@@ -5384,19 +5373,22 @@ pick_task(struct rq *rq, const struct sched_class *class, struct task_struct *ma
* the core (so far) and it must be selected, otherwise we must go with
* the cookie pick in order to satisfy the constraint.
*/
- if (prio_less(cookie_pick, class_pick) &&
- (!max || prio_less(max, class_pick)))
+ if (prio_less(cookie_pick, class_pick, in_fi) &&
+ (!max || prio_less(max, class_pick, in_fi)))
return class_pick;
return cookie_pick;
}
+extern void task_vruntime_update(struct rq *rq, struct task_struct *p, bool in_fi);
+
static struct task_struct *
pick_next_task(struct rq *rq, struct task_struct *prev, struct rq_flags *rf)
{
struct task_struct *next, *max = NULL;
const struct sched_class *class;
const struct cpumask *smt_mask;
+ bool fi_before = false;
bool need_sync;
int i, j, cpu;
@@ -5478,9 +5470,14 @@ pick_next_task(struct rq *rq, struct task_struct *prev, struct rq_flags *rf)
if (!next->core_cookie) {
rq->core_pick = NULL;
+ /*
+ * For robustness, update the min_vruntime_fi for
+ * unconstrained picks as well.
+ */
+ WARN_ON_ONCE(fi_before);
+ task_vruntime_update(rq, next, false);
goto done;
}
- need_sync = true;
}
for_each_cpu(i, smt_mask) {
@@ -5511,11 +5508,16 @@ again:
* highest priority task already selected for this
* core.
*/
- p = pick_task(rq_i, class, max);
+ p = pick_task(rq_i, class, max, fi_before);
if (!p)
continue;
rq_i->core_pick = p;
+ if (rq_i->idle == p && rq_i->nr_running) {
+ rq->core->core_forceidle = true;
+ if (!fi_before)
+ rq->core->core_forceidle_seq++;
+ }
/*
* If this new candidate is of higher priority than the
@@ -5534,6 +5536,7 @@ again:
max = p;
if (old_max) {
+ rq->core->core_forceidle = false;
for_each_cpu(j, smt_mask) {
if (j == i)
continue;
@@ -5574,10 +5577,16 @@ again:
if (!rq_i->core_pick)
continue;
- if (is_task_rq_idle(rq_i->core_pick) && rq_i->nr_running &&
- !rq_i->core->core_forceidle) {
- rq_i->core->core_forceidle = true;
- }
+ /*
+ * Update for new !FI->FI transitions, or if continuing to be in !FI:
+ * fi_before fi update?
+ * 0 0 1
+ * 0 1 1
+ * 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 (i == cpu) {
rq_i->core_pick = NULL;