[PATCH 5/7 v4] sched/fair: reorder newidle_balance pulled_task tests

From: Vincent Guittot
Date: Wed Feb 24 2021 - 09:51:56 EST


Reorder the tests and skip useless ones when no load balance has been
performed and rq lock has not been released.

Signed-off-by: Vincent Guittot <vincent.guittot@xxxxxxxxxx>
---
kernel/sched/fair.c | 10 +++++-----
1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 0323fda07682..586f6ce0d302 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -10584,7 +10584,6 @@ static int newidle_balance(struct rq *this_rq, struct rq_flags *rf)
if (curr_cost > this_rq->max_idle_balance_cost)
this_rq->max_idle_balance_cost = curr_cost;

-out:
/*
* While browsing the domains, we released the rq lock, a task could
* have been enqueued in the meantime. Since we're not going idle,
@@ -10593,14 +10592,15 @@ static int newidle_balance(struct rq *this_rq, struct rq_flags *rf)
if (this_rq->cfs.h_nr_running && !pulled_task)
pulled_task = 1;

- /* Move the next balance forward */
- if (time_after(this_rq->next_balance, next_balance))
- this_rq->next_balance = next_balance;
-
/* Is there a task of a high priority class? */
if (this_rq->nr_running != this_rq->cfs.h_nr_running)
pulled_task = -1;

+out:
+ /* Move the next balance forward */
+ if (time_after(this_rq->next_balance, next_balance))
+ this_rq->next_balance = next_balance;
+
if (pulled_task)
this_rq->idle_stamp = 0;
else
--
2.17.1