1 files changed, 41 insertions, 1 deletions

diff --git a/kernel/sched_idletask.c b/kernel/sched_idletask.c
index bf9c25c15b8b..2bcafa375633 100644
--- a/kernel/sched_idletask.c
+++ b/kernel/sched_idletask.c
@@ -5,6 +5,12 @@
  *  handled in sched_fair.c)
  */
 
+#ifdef CONFIG_SMP
+static int select_task_rq_idle(struct task_struct *p, int sync)
+{
+	return task_cpu(p); /* IDLE tasks as never migrated */
+}
+#endif /* CONFIG_SMP */
 /*
  * Idle tasks are unconditionally rescheduled:
  */
@@ -55,7 +61,7 @@ move_one_task_idle(struct rq *this_rq, int this_cpu, struct rq *busiest,
 }
 #endif
 
-static void task_tick_idle(struct rq *rq, struct task_struct *curr)
+static void task_tick_idle(struct rq *rq, struct task_struct *curr, int queued)
 {
 }
 
@@ -63,6 +69,33 @@ static void set_curr_task_idle(struct rq *rq)
 {
 }
 
+static void switched_to_idle(struct rq *rq, struct task_struct *p,
+			     int running)
+{
+	/* Can this actually happen?? */
+	if (running)
+		resched_task(rq->curr);
+	else
+		check_preempt_curr(rq, p);
+}
+
+static void prio_changed_idle(struct rq *rq, struct task_struct *p,
+			      int oldprio, int running)
+{
+	/* This can happen for hot plug CPUS */
+
+	/*
+	 * Reschedule if we are currently running on this runqueue and
+	 * our priority decreased, or if we are not currently running on
+	 * this runqueue and our priority is higher than the current's
+	 */
+	if (running) {
+		if (p->prio > oldprio)
+			resched_task(rq->curr);
+	} else
+		check_preempt_curr(rq, p);
+}
+
 /*
  * Simple, special scheduling class for the per-CPU idle tasks:
  */
@@ -72,6 +105,9 @@ const struct sched_class idle_sched_class = {
 
 	/* dequeue is not valid, we print a debug message there: */
 	.dequeue_task		= dequeue_task_idle,
+#ifdef CONFIG_SMP
+	.select_task_rq		= select_task_rq_idle,
+#endif /* CONFIG_SMP */
 
 	.check_preempt_curr	= check_preempt_curr_idle,
 
@@ -85,5 +121,9 @@ const struct sched_class idle_sched_class = {
 
 	.set_curr_task          = set_curr_task_idle,
 	.task_tick		= task_tick_idle,
+
+	.prio_changed		= prio_changed_idle,
+	.switched_to		= switched_to_idle,
+
 	/* no .task_new for idle tasks */
 };