[PATCH] sched/fair: Remove empty idle enter and exit functions.

* [PATCH] sched/fair: Remove empty idle enter and exit functions.
@ 2015-10-20 12:04 Dietmar Eggemann
  2015-11-23 16:17 ` [tip:sched/core] " tip-bot for Dietmar Eggemann
  0 siblings, 1 reply; 2+ messages in thread
From: Dietmar Eggemann @ 2015-10-20 12:04 UTC (permalink / raw)
  To: Peter Zijlstra, Ingo Molnar; +Cc: linux-kernel, Yuyang Du

Commit cd126afe838d ("sched/fair: Remove rq's runnable avg") got rid of
rq->avg and so there is no need to update it any more when entering or
exiting idle.

Remove the now empty functions idle_{enter|exit}_fair().

Signed-off-by: Dietmar Eggemann <dietmar.eggemann@arm.com>
---
 kernel/sched/fair.c      | 24 +-----------------------
 kernel/sched/idle_task.c |  1 -
 kernel/sched/sched.h     |  8 --------
 3 files changed, 1 insertion(+), 32 deletions(-)

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 824aa9f501a3..54e2cb4ed027 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -2835,24 +2835,6 @@ void remove_entity_load_avg(struct sched_entity *se)
 	atomic_long_add(se->avg.util_avg, &cfs_rq->removed_util_avg);
 }
 
-/*
- * Update the rq's load with the elapsed running time before entering
- * idle. if the last scheduled task is not a CFS task, idle_enter will
- * be the only way to update the runnable statistic.
- */
-void idle_enter_fair(struct rq *this_rq)
-{
-}
-
-/*
- * Update the rq's load with the elapsed idle time before a task is
- * scheduled. if the newly scheduled task is not a CFS task, idle_exit will
- * be the only way to update the runnable statistic.
- */
-void idle_exit_fair(struct rq *this_rq)
-{
-}
-
 static inline unsigned long cfs_rq_runnable_load_avg(struct cfs_rq *cfs_rq)
 {
 	return cfs_rq->runnable_load_avg;
@@ -7248,8 +7230,6 @@ static int idle_balance(struct rq *this_rq)
 	int pulled_task = 0;
 	u64 curr_cost = 0;
 
-	idle_enter_fair(this_rq);
-
 	/*
 	 * We must set idle_stamp _before_ calling idle_balance(), such that we
 	 * measure the duration of idle_balance() as idle time.
@@ -7330,10 +7310,8 @@ static int idle_balance(struct rq *this_rq)
 	if (this_rq->nr_running != this_rq->cfs.h_nr_running)
 		pulled_task = -1;
 
-	if (pulled_task) {
-		idle_exit_fair(this_rq);
+	if (pulled_task)
 		this_rq->idle_stamp = 0;
-	}
 
 	return pulled_task;
 }
diff --git a/kernel/sched/idle_task.c b/kernel/sched/idle_task.c
index c4ae0f1fdf9b..47ce94931f1b 100644
--- a/kernel/sched/idle_task.c
+++ b/kernel/sched/idle_task.c
@@ -47,7 +47,6 @@ dequeue_task_idle(struct rq *rq, struct task_struct *p, int flags)
 
 static void put_prev_task_idle(struct rq *rq, struct task_struct *prev)
 {
-	idle_exit_fair(rq);
 	rq_last_tick_reset(rq);
 }
 
diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h
index efd3bfc7e347..2eb2002aa336 100644
--- a/kernel/sched/sched.h
+++ b/kernel/sched/sched.h
@@ -1249,16 +1249,8 @@ extern void update_group_capacity(struct sched_domain *sd, int cpu);
 
 extern void trigger_load_balance(struct rq *rq);
 
-extern void idle_enter_fair(struct rq *this_rq);
-extern void idle_exit_fair(struct rq *this_rq);
-
 extern void set_cpus_allowed_common(struct task_struct *p, const struct cpumask *new_mask);
 
-#else
-
-static inline void idle_enter_fair(struct rq *rq) { }
-static inline void idle_exit_fair(struct rq *rq) { }
-
 #endif
 
 #ifdef CONFIG_CPU_IDLE
-- 
1.9.1


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