diff --git a/kernel/cpu.c b/kernel/cpu.c index 49273130e4f1..96c0a868232e 100644 --- a/kernel/cpu.c +++ b/kernel/cpu.c @@ -494,8 +494,7 @@ static int bringup_wait_for_ap(unsigned int cpu) if (WARN_ON_ONCE((!cpu_online(cpu)))) return -ECANCELED; - /* Unpark the stopper thread and the hotplug thread of the target cpu */ - stop_machine_unpark(cpu); + /* Unpark the hotplug thread of the target cpu */ kthread_unpark(st->thread); /* @@ -1064,8 +1063,8 @@ void notify_cpu_starting(unsigned int cpu) /* * Called from the idle task. Wake up the controlling task which brings the - * stopper and the hotplug thread of the upcoming CPU up and then delegates - * the rest of the online bringup to the hotplug thread. + * hotplug thread of the upcoming CPU up and then delegates the rest of the + * online bringup to the hotplug thread. */ void cpuhp_online_idle(enum cpuhp_state state) { @@ -1075,6 +1074,12 @@ void cpuhp_online_idle(enum cpuhp_state state) if (state != CPUHP_AP_ONLINE_IDLE) return; + /* + * Unpart the stopper thread before we start the idle loop (and start + * scheduling); this ensures the stopper task is always available. + */ + stop_machine_unpark(smp_processor_id()); + st->state = CPUHP_AP_ONLINE_IDLE; complete_ap_thread(st, true); }