3 files changed, 22 insertions, 11 deletions

diff --git a/include/linux/sched.h b/include/linux/sched.h
index e5f928a079e8..836a86c32a65 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -1012,6 +1012,7 @@ struct sched_class {
                               struct rq *busiest, struct sched_domain *sd,
                               enum cpu_idle_type idle);
         void (*pre_schedule) (struct rq *this_rq, struct task_struct *task);
+        int (*needs_post_schedule) (struct rq *this_rq);
         void (*post_schedule) (struct rq *this_rq);
         void (*task_wake_up) (struct rq *this_rq, struct task_struct *task);
 
diff --git a/kernel/sched.c b/kernel/sched.c
index 8fca364f3593..3acbad8991a2 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -2621,6 +2621,12 @@ static void finish_task_switch(struct rq *rq, struct task_struct *prev)
 {
         struct mm_struct *mm = rq->prev_mm;
         long prev_state;
+#ifdef CONFIG_SMP
+        int post_schedule = 0;
+
+        if (current->sched_class->needs_post_schedule)
+                post_schedule = current->sched_class->needs_post_schedule(rq);
+#endif
 
         rq->prev_mm = NULL;
 
@@ -2639,7 +2645,7 @@ static void finish_task_switch(struct rq *rq, struct task_struct *prev)
         finish_arch_switch(prev);
         finish_lock_switch(rq, prev);
 #ifdef CONFIG_SMP
-        if (current->sched_class->post_schedule)
+        if (post_schedule)
                 current->sched_class->post_schedule(rq);
 #endif
 
diff --git a/kernel/sched_rt.c b/kernel/sched_rt.c
index 8d33843cb2c4..b0b6ea4ed674 100644
--- a/kernel/sched_rt.c
+++ b/kernel/sched_rt.c
@@ -1290,20 +1290,23 @@ static void pre_schedule_rt(struct rq *rq, struct task_struct *prev)
                 pull_rt_task(rq);
 }
 
+/*
+ * assumes rq->lock is held
+ */
+static int needs_post_schedule_rt(struct rq *rq)
+{
+        return rq->rt.overloaded ? 1 : 0;
+}
+
 static void post_schedule_rt(struct rq *rq)
 {
         /*
-         * If we have more than one rt_task queued, then
-         * see if we can push the other rt_tasks off to other CPUS.
-         * Note we may release the rq lock, and since
-         * the lock was owned by prev, we need to release it
-         * first via finish_lock_switch and then reaquire it here.
+         * This is only called if needs_post_schedule_rt() indicates that
+         * we need to push tasks away
          */
-        if (unlikely(rq->rt.overloaded)) {
-                spin_lock_irq(&rq->lock);
-                push_rt_tasks(rq);
-                spin_unlock_irq(&rq->lock);
-        }
+        spin_lock_irq(&rq->lock);
+        push_rt_tasks(rq);
+        spin_unlock_irq(&rq->lock);
 }
 
 /*
@@ -1557,6 +1560,7 @@ static const struct sched_class rt_sched_class = {
         .rq_online              = rq_online_rt,
         .rq_offline             = rq_offline_rt,
         .pre_schedule           = pre_schedule_rt,
+        .needs_post_schedule    = needs_post_schedule_rt,
         .post_schedule          = post_schedule_rt,
         .task_wake_up           = task_wake_up_rt,
         .switched_from          = switched_from_rt,