[PATCH] sched/fair: enqueue_task_fair optimization

From: Vincent Guittot
Date: Mon May 11 2020 - 15:23:13 EST


enqueue_task_fair() jumps to enqueue_throttle when cfs_rq_of(se) is
throttled, which means that se can't be NULL and we can skip the test.

Signed-off-by: Vincent Guittot <vincent.guittot@xxxxxxxxxx>
---
kernel/sched/fair.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 4b73518aa25c..910bbbe50365 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -5512,7 +5512,6 @@ enqueue_task_fair(struct rq *rq, struct task_struct *p, int flags)
list_add_leaf_cfs_rq(cfs_rq);
}

-enqueue_throttle:
if (!se) {
add_nr_running(rq, 1);
/*
@@ -5534,6 +5533,7 @@ enqueue_task_fair(struct rq *rq, struct task_struct *p, int flags)

}

+enqueue_throttle:
if (cfs_bandwidth_used()) {
/*
* When bandwidth control is enabled; the cfs_rq_throttled()
--
2.17.1