Index: linux-2.6.12-mm1/kernel/sched.c
===================================================================
--- linux-2.6.12-mm1.orig/kernel/sched.c	2005-06-26 13:12:24.000000000 +1000
+++ linux-2.6.12-mm1/kernel/sched.c	2005-06-26 14:53:11.000000000 +1000
@@ -669,6 +669,35 @@ static inline void dec_prio_bias(runqueu
 {
 	rq->prio_bias -= MAX_PRIO - prio;
 }
+
+static inline void inc_nr_running(task_t *p, runqueue_t *rq)
+{
+	rq->nr_running++;
+	if (rt_task(p)) {
+		/*
+		 * The migration thread does the actual balancing so its
+		 * effect on the priority bias should be minimal as it would
+		 * would otherwise be seen as ultra high priority.
+		 */
+		if (p == rq->migration_thread)
+			inc_prio_bias(rq, MAX_PRIO - 1);
+		else
+			inc_prio_bias(rq, p->prio);
+	} else
+		inc_prio_bias(rq, p->static_prio);
+}
+
+static inline void dec_nr_running(task_t *p, runqueue_t *rq)
+{
+	rq->nr_running--;
+	if (rt_task(p)) {
+		if (p == rq->migration_thread)
+			dec_prio_bias(rq, MAX_PRIO - 1);
+		else
+			dec_prio_bias(rq, p->prio);
+	} else
+		dec_prio_bias(rq, p->static_prio);
+}
 #else
 static inline void inc_prio_bias(runqueue_t *rq, int prio)
 {
@@ -677,25 +706,17 @@ static inline void inc_prio_bias(runqueu
 static inline void dec_prio_bias(runqueue_t *rq, int prio)
 {
 }
-#endif
 
 static inline void inc_nr_running(task_t *p, runqueue_t *rq)
 {
 	rq->nr_running++;
-	if (rt_task(p))
-		inc_prio_bias(rq, p->prio);
-	else
-		inc_prio_bias(rq, p->static_prio);
 }
 
 static inline void dec_nr_running(task_t *p, runqueue_t *rq)
 {
 	rq->nr_running--;
-	if (rt_task(p))
-		dec_prio_bias(rq, p->prio);
-	else
-		dec_prio_bias(rq, p->static_prio);
 }
+#endif
 
 /*
  * __activate_task - move a task to the runqueue.