diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 2e08b88cce12..88eae79d1a3c 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -8343,6 +8343,7 @@ static int idle_balance(struct rq *this_rq) struct sched_domain *sd; int pulled_task = 0; u64 curr_cost = 0; + long removed_util=0; idle_enter_fair(this_rq); @@ -8366,6 +8367,17 @@ static int idle_balance(struct rq *this_rq) raw_spin_unlock(&this_rq->lock); + /* + * If removed_util_avg is !0 we most probably migrated some task away + * from this_cpu. In this case we might be willing to trigger an OPP + * update, but we want to do so if we don't find anybody else to pull + * here (we will trigger an OPP update with the pulled task's enqueue + * anyway). + * + * Record removed_util before calling update_blocked_averages, and use + * it below (before returning) to see if an OPP update is required. + */ + removed_util = atomic_long_read(&(this_rq->cfs).removed_util_avg); update_blocked_averages(this_cpu); rcu_read_lock(); for_each_domain(this_cpu, sd) { @@ -8430,6 +8442,12 @@ out: if (pulled_task) { idle_exit_fair(this_rq); this_rq->idle_stamp = 0; + } else if (removed_util) { + /* + * No task pulled and someone has been migrated away. + * Good case to trigger an OPP update. + */ + update_capacity_of(this_cpu); } return pulled_task;