[PATCH 3.14 042/130] sched: Clean up idle task SMP logic

[Greg Kroah-Hartman]

3.14-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Peter Zijlstra <peterz@xxxxxxxxxxxxx>

commit 6c3b4d44ba2838f00614a5a2d777d4401e0bfd71 upstream.

The idle post_schedule flag is just a vile waste of time, furthermore
it appears unneeded, move the idle_enter_fair() call into
pick_next_task_idle().

Signed-off-by: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Daniel Lezcano <daniel.lezcano@xxxxxxxxxx>
Cc: Vincent Guittot <vincent.guittot@xxxxxxxxxx>
Cc: alex.shi@xxxxxxxxxx
Cc: mingo@xxxxxxxxxx
Cc: Steven Rostedt <rostedt@xxxxxxxxxxx>
Link: http://lkml.kernel.org/n/tip-aljykihtxJt3mkokxi0qZurb@xxxxxxxxxxxxxx
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: Byungchul Park <byungchul.park@xxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 kernel/sched/idle_task.c |    9 +--------
 1 file changed, 1 insertion(+), 8 deletions(-)

--- a/kernel/sched/idle_task.c
+++ b/kernel/sched/idle_task.c
@@ -19,11 +19,6 @@ static void pre_schedule_idle(struct rq
 	idle_exit_fair(rq);
 	rq_last_tick_reset(rq);
 }
-
-static void post_schedule_idle(struct rq *rq)
-{
-	idle_enter_fair(rq);
-}
 #endif /* CONFIG_SMP */
 /*
  * Idle tasks are unconditionally rescheduled:
@@ -37,8 +32,7 @@ static struct task_struct *pick_next_tas
 {
 	schedstat_inc(rq, sched_goidle);
 #ifdef CONFIG_SMP
-	/* Trigger the post schedule to do an idle_enter for CFS */
-	rq->post_schedule = 1;
+	idle_enter_fair(rq);
 #endif
 	return rq->idle;
 }
@@ -102,7 +96,6 @@ const struct sched_class idle_sched_clas
 #ifdef CONFIG_SMP
 	.select_task_rq		= select_task_rq_idle,
 	.pre_schedule		= pre_schedule_idle,
-	.post_schedule		= post_schedule_idle,
 #endif
 
 	.set_curr_task          = set_curr_task_idle,