sched/fair: Sync load_sum with load_avg after dequeue

commit 9e077b5 ("sched/pelt: Check that *_avg are null when *_sum are")
reported some inconsitencies between *_avg and *_sum.

commit 1c35b07 ("sched/fair: Ensure _sum and _avg values stay consistent")
fixed some but one remains when dequeuing load.

sync the cfs's load_sum with its load_avg after dequeuing the load of a
sched_entity.

Fixes: 9e077b5 ("sched/pelt: Check that *_avg are null when *_sum are")
Reported-by: Sachin Sant <[email protected]>
Signed-off-by: Vincent Guittot <[email protected]>
Signed-off-by: Peter Zijlstra (Intel) <[email protected]>
Reviewed-by: Odin Ugedal <[email protected]>
Tested-by: Sachin Sant <[email protected]>
Link: https://lore.kernel.org/r/[email protected]

kernel/sched/fair.c

@@ -3037,8 +3037,9 @@ enqueue_load_avg(struct cfs_rq *cfs_rq, struct sched_entity *se)
 static inline void
 dequeue_load_avg(struct cfs_rq *cfs_rq, struct sched_entity *se)
 {
+	u32 divider = get_pelt_divider(&se->avg);
 	sub_positive(&cfs_rq->avg.load_avg, se->avg.load_avg);
-	sub_positive(&cfs_rq->avg.load_sum, se_weight(se) * se->avg.load_sum);
+	cfs_rq->avg.load_sum = cfs_rq->avg.load_avg * divider;
 }
 #else
 static inline void