[PATCH 1/2][v2] sched: Make newidle_balance() static again

[Chen Yu]

After Commit 6e2df0581f56 ("sched: Fix pick_next_task() vs 'change'
pattern race"), there is no need to expose newidle_balance() as it
is only used within fair.c file. Change this function back to static again.

No functional change.

Suggested-by: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Reported-by: kbuild test robot <lkp@xxxxxxxxx>
Signed-off-by: Chen Yu <yu.c.chen@xxxxxxxxx>
---
v2: Rename the remaining idle_balance() to newidle_balance()
    to fix an compile error when CONFIG_SMP is not set.
---
 kernel/sched/fair.c  | 6 ++++--
 kernel/sched/sched.h | 4 ----
 2 files changed, 4 insertions(+), 6 deletions(-)

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 02f323b85b6d..cca5c9b7b5ae 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -3873,6 +3873,8 @@ static inline unsigned long cfs_rq_load_avg(struct cfs_rq *cfs_rq)
 	return cfs_rq->avg.load_avg;
 }
 
+static int newidle_balance(struct rq *this_rq, struct rq_flags *rf);
+
 static inline unsigned long task_util(struct task_struct *p)
 {
 	return READ_ONCE(p->se.avg.util_avg);
@@ -4054,7 +4056,7 @@ attach_entity_load_avg(struct cfs_rq *cfs_rq, struct sched_entity *se) {}
 static inline void
 detach_entity_load_avg(struct cfs_rq *cfs_rq, struct sched_entity *se) {}
 
-static inline int idle_balance(struct rq *rq, struct rq_flags *rf)
+static inline int newidle_balance(struct rq *rq, struct rq_flags *rf)
 {
 	return 0;
 }
@@ -10425,7 +10427,7 @@ static inline void nohz_newidle_balance(struct rq *this_rq) { }
  *     0 - failed, no new tasks
  *   > 0 - success, new (fair) tasks present
  */
-int newidle_balance(struct rq *this_rq, struct rq_flags *rf)
+static int newidle_balance(struct rq *this_rq, struct rq_flags *rf)
 {
 	unsigned long next_balance = jiffies + HZ;
 	int this_cpu = this_rq->cpu;
diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h
index db3a57675ccf..be83f88495fb 100644
--- a/kernel/sched/sched.h
+++ b/kernel/sched/sched.h
@@ -1504,14 +1504,10 @@ static inline void unregister_sched_domain_sysctl(void)
 }
 #endif
 
-extern int newidle_balance(struct rq *this_rq, struct rq_flags *rf);
-
 #else
 
 static inline void sched_ttwu_pending(void) { }
 
-static inline int newidle_balance(struct rq *this_rq, struct rq_flags *rf) { return 0; }
-
 #endif /* CONFIG_SMP */
 
 #include "stats.h"
-- 
2.17.1