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

From: Dietmar Eggemann
Date: Tue Oct 20 2015 - 08:04:59 EST


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@xxxxxxx>
---
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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