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-rw-r--r--kernel/sched.c41
1 files changed, 23 insertions, 18 deletions
diff --git a/kernel/sched.c b/kernel/sched.c
index d9dbf8e..ec9ea911 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)
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