kernel/sched: Fix util_est accounting for DELAY_DEQUEUE

Remove delayed tasks from util_est even they are runnable.

Exclude delayed task which are (a) migrating between rq's or (b) in a
SAVE/RESTORE dequeue/enqueue.

Signed-off-by: Dietmar Eggemann <dietmar.eggemann@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/c49ef5fe-a909-43f1-b02f-a765ab9cedbf@arm.com

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index e946ca0b1ecdf057ec72ae4687767b3cb3212343..922d690316617309102cc238a928730160fc06b9 100644 (file)
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -6948,18 +6948,19 @@ enqueue_task_fair(struct rq *rq, struct task_struct *p, int flags)
        int rq_h_nr_running = rq->cfs.h_nr_running;
        u64 slice = 0;
 
-       if (flags & ENQUEUE_DELAYED) {
-               requeue_delayed_entity(se);
-               return;
-       }
-
        /*
         * The code below (indirectly) updates schedutil which looks at
         * the cfs_rq utilization to select a frequency.
         * Let's add the task's estimated utilization to the cfs_rq's
         * estimated utilization, before we update schedutil.
         */
-       util_est_enqueue(&rq->cfs, p);
+       if (!(p->se.sched_delayed && (task_on_rq_migrating(p) || (flags & ENQUEUE_RESTORE))))
+               util_est_enqueue(&rq->cfs, p);
+
+       if (flags & ENQUEUE_DELAYED) {
+               requeue_delayed_entity(se);
+               return;
+       }
 
        /*
         * If in_iowait is set, the code below may not trigger any cpufreq
@@ -7177,7 +7178,8 @@ static int dequeue_entities(struct rq *rq, struct sched_entity *se, int flags)
  */
 static bool dequeue_task_fair(struct rq *rq, struct task_struct *p, int flags)
 {
-       util_est_dequeue(&rq->cfs, p);
+       if (!(p->se.sched_delayed && (task_on_rq_migrating(p) || (flags & DEQUEUE_SAVE))))
+               util_est_dequeue(&rq->cfs, p);
 
        if (dequeue_entities(rq, &p->se, flags) < 0) {
                util_est_update(&rq->cfs, p, DEQUEUE_SLEEP);