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 we are balancing busy runqueues the load is biased by - * priority to create 'nice' support across cpus. - */ - cpu_load *= rq->prio_bias; - load_now *= rq->prio_bias; - } - if (type == 0) - return load_now; + source_load = load_now; + else + source_load = min(cpu_load, load_now); - return min(cpu_load, load_now); + if (idle == NOT_IDLE || rq->nr_running > 1) + /* + * 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. + */ + source_load *= rq->prio_bias; + + 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)