When combined with the next patch, which breaks out of rebalancing when an RT task is runnable, significant latency reductions are seen on systems with many CPUs. Signed-off-by: Scott Wood <swood@xxxxxxxxxx> --- kernel/sched/fair.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 74c3c5280d6b..dfde7f0ce3db 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -10376,7 +10376,7 @@ static void nohz_newidle_balance(struct rq *this_rq) time_before(jiffies, READ_ONCE(nohz.next_blocked))) return; - raw_spin_unlock(&this_rq->lock); + raw_spin_unlock_irq(&this_rq->lock); /* * This CPU is going to be idle and blocked load of idle CPUs * need to be updated. Run the ilb locally as it is a good @@ -10385,7 +10385,7 @@ static void nohz_newidle_balance(struct rq *this_rq) */ if (!_nohz_idle_balance(this_rq, NOHZ_STATS_KICK, CPU_NEWLY_IDLE)) kick_ilb(NOHZ_STATS_KICK); - raw_spin_lock(&this_rq->lock); + raw_spin_lock_irq(&this_rq->lock); } #else /* !CONFIG_NO_HZ_COMMON */ @@ -10452,7 +10452,7 @@ int newidle_balance(void) goto out; } - raw_spin_unlock(&this_rq->lock); + raw_spin_unlock_irq(&this_rq->lock); update_blocked_averages(this_cpu); rcu_read_lock(); @@ -10493,7 +10493,7 @@ int newidle_balance(void) } rcu_read_unlock(); - raw_spin_lock(&this_rq->lock); + raw_spin_lock_irq(&this_rq->lock); if (curr_cost > this_rq->max_idle_balance_cost) this_rq->max_idle_balance_cost = curr_cost; -- 2.18.2
