1 files changed, 23 insertions, 18 deletions

diff --git a/kernel/sched.c b/kernel/sched.c
index d9dbf8ee6ca4..ec9ea9119b98 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -972,22 +972,26 @@ void kick_process(task_t *p)
 static inline unsigned long __source_load(int cpu, int type, enum idle_type idle)
 {
         runqueue_t *rq = cpu_rq(cpu);
-        unsigned long cpu_load = rq->cpu_load[type-1],
+        unsigned long source_load, cpu_load = rq->cpu_load[type-1],
                 load_now = rq->nr_running * SCHED_LOAD_SCALE;
 
-        if (idle == NOT_IDLE) {
+        if (type == 0)
+                source_load = load_now;
+        else
+                source_load = min(cpu_load, load_now);
+
+        if (idle == NOT_IDLE || rq->nr_running > 1)
                 /*
-                 * If we are balancing busy runqueues the load is biased by
-                 * priority to create 'nice' support across cpus.
+                 * If we are busy rebalancing the load is biased by
+                 * priority to create 'nice' support across cpus. When
+                 * idle rebalancing we should only bias the source_load if
+                 * there is more than one task running on that queue to
+                 * prevent idle rebalance from trying to pull tasks from a
+                 * queue with only one running task.
                  */
-                cpu_load *= rq->prio_bias;
-                load_now *= rq->prio_bias;
-        }
+                source_load *= rq->prio_bias;
 
-        if (type == 0)
-                return load_now;
-
-        return min(cpu_load, load_now);
+        return source_load;
 }
 
 static inline unsigned long source_load(int cpu, int type)
@@ -1001,17 +1005,18 @@ static inline unsigned long source_load(int cpu, int type)
 static inline unsigned long __target_load(int cpu, int type, enum idle_type idle)
 {
         runqueue_t *rq = cpu_rq(cpu);
-        unsigned long cpu_load = rq->cpu_load[type-1],
+        unsigned long target_load, cpu_load = rq->cpu_load[type-1],
                 load_now = rq->nr_running * SCHED_LOAD_SCALE;
 
         if (type == 0)
-                return load_now;
+                target_load = load_now;
+        else
+                target_load = max(cpu_load, load_now);
 
-        if (idle == NOT_IDLE) {
-                cpu_load *= rq->prio_bias;
-                load_now *= rq->prio_bias;
-        }
-        return max(cpu_load, load_now);
+        if (idle == NOT_IDLE || rq->nr_running > 1)
+                target_load *= rq->prio_bias;
+
+        return target_load;
 }
 
 static inline unsigned long target_load(int cpu, int type)