check_misfit_status() checks for both capacity pressure & available CPUs
with higher capacity. Now that we have a sane(ish) capacity comparison
margin which is used throughout load-balance, this can be condensed into a
single check:
capacity_greater(<root_domain max capacity>, <misfit task CPU's capacity>);
This has the added benefit of returning false if the misfit task CPU's is
heavily pressured, but there are no better candidates for migration.
Signed-off-by: Valentin Schneider <valentin.schnei...@arm.com>
---
kernel/sched/fair.c | 10 ++++------
1 file changed, 4 insertions(+), 6 deletions(-)
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 0959a770ecc0..ef44474b8fbf 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -8254,14 +8254,12 @@ check_cpu_capacity(struct rq *rq, struct sched_domain
*sd)
/*
* Check whether a rq has a misfit task and if it looks like we can actually
- * help that task: we can migrate the task to a CPU of higher capacity, or
- * the task's current CPU is heavily pressured.
+ * help that task: we can migrate the task to a CPU of higher capacity.
*/
-static inline int check_misfit_status(struct rq *rq, struct sched_domain *sd)
+static inline int check_misfit_status(struct rq *rq)
{
return rq->misfit_task_load &&
- (capacity_greater(rq->rd->max_cpu_capacity,
rq->cpu_capacity_orig) ||
- check_cpu_capacity(rq, sd));
+ capacity_greater(rq->rd->max_cpu_capacity, rq->cpu_capacity);
}
/*
@@ -10238,7 +10236,7 @@ static void nohz_balancer_kick(struct rq *rq)
* When ASYM_CPUCAPACITY; see if there's a higher capacity CPU
* to run the misfit task on.
*/
- if (check_misfit_status(rq, sd)) {
+ if (check_misfit_status(rq)) {
flags = NOHZ_KICK_MASK;
goto unlock;
}
--
2.27.0
