From 8850cb663b5cda04d33f9cfbc38889d73d3c8e24 Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Tue, 21 Sep 2021 22:16:02 +0200 Subject: sched: Simplify wake_up_*idle*() Simplify and make wake_up_if_idle() more robust, also don't iterate the whole machine with preempt_disable() in it's caller: wake_up_all_idle_cpus(). This prepares for another wake_up_if_idle() user that needs a full do_idle() cycle. Signed-off-by: Peter Zijlstra (Intel) Acked-by: Vasily Gorbik Tested-by: Vasily Gorbik # on s390 Link: https://lkml.kernel.org/r/20210929152428.769328779@infradead.org --- kernel/sched/core.c | 14 +++++--------- 1 file changed, 5 insertions(+), 9 deletions(-) (limited to 'kernel/sched') diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 74db3c3afa6d..3b55ef99c03f 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -3695,15 +3695,11 @@ void wake_up_if_idle(int cpu) if (!is_idle_task(rcu_dereference(rq->curr))) goto out; - if (set_nr_if_polling(rq->idle)) { - trace_sched_wake_idle_without_ipi(cpu); - } else { - rq_lock_irqsave(rq, &rf); - if (is_idle_task(rq->curr)) - smp_send_reschedule(cpu); - /* Else CPU is not idle, do nothing here: */ - rq_unlock_irqrestore(rq, &rf); - } + rq_lock_irqsave(rq, &rf); + if (is_idle_task(rq->curr)) + resched_curr(rq); + /* Else CPU is not idle, do nothing here: */ + rq_unlock_irqrestore(rq, &rf); out: rcu_read_unlock(); -- cgit