diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 4e305d174b55..36774e5dab01 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -7647,8 +7647,22 @@ out: * When the cpu is attached to null domain for ex, it will not be * updated. */ - if (likely(update_next_balance)) + if (likely(update_next_balance)) { rq->next_balance = next_balance; + +#ifdef CONFIG_NO_HZ_COMMON + /* + * If this CPU has been elected to perform the nohz idle + * balance. Other idle CPUs have already rebalanced with + * nohz_idle_balance() and nohz.next_balance has been + * updated accordingly. This CPU is now running the idle load + * balance for itself and we need to update the + * nohz.next_balance accordingly. + */ + if ((idle == CPU_IDLE) && time_after(nohz.next_balance, rq->next_balance)) + nohz.next_balance = rq->next_balance; +#endif + } } #ifdef CONFIG_NO_HZ_COMMON @@ -7661,6 +7675,9 @@ static void nohz_idle_balance(struct rq *this_rq, enum cpu_idle_type idle) int this_cpu = this_rq->cpu; struct rq *rq; int balance_cpu; + /* Earliest time when we have to do rebalance again */ + unsigned long next_balance = jiffies + 60*HZ; + int update_next_balance = 0; if (idle != CPU_IDLE || !test_bit(NOHZ_BALANCE_KICK, nohz_flags(this_cpu))) @@ -7692,10 +7709,19 @@ static void nohz_idle_balance(struct rq *this_rq, enum cpu_idle_type idle) rebalance_domains(rq, CPU_IDLE); } - if (time_after(this_rq->next_balance, rq->next_balance)) - this_rq->next_balance = rq->next_balance; + if (time_after(next_balance, rq->next_balance)) { + next_balance = rq->next_balance; + update_next_balance = 1; + } } - nohz.next_balance = this_rq->next_balance; + + /* + * next_balance will be updated only when there is a need. + * When the CPU is attached to null domain for ex, it will not be + * updated. + */ + if (likely(update_next_balance)) + nohz.next_balance = next_balance; end: clear_bit(NOHZ_BALANCE_KICK, nohz_flags(this_cpu)); }