linux-master/kernel/cpu.c

484 DEFINE_STATIC_PERCPU_RWSEM(cpu_hotplug_lock);
488 	percpu_down_read(&cpu_hotplug_lock);
494 	return percpu_down_read_trylock(&cpu_hotplug_lock);
500 	percpu_up_read(&cpu_hotplug_lock);
506 	percpu_down_write(&cpu_hotplug_lock);
511 	percpu_up_write(&cpu_hotplug_lock);
525 	percpu_rwsem_assert_held(&cpu_hotplug_lock);
531 	return percpu_rwsem_is_held(&cpu_hotplug_lock);
537 	rwsem_acquire(&cpu_hotplug_lock.dep_map, 0, 0, _THIS_IP_);
542 	rwsem_release(&cpu_hotplug_lock.dep_map, _THIS_IP_);
1213  * Serialize hotplug trainwrecks outside of the cpu_hotplug_lock
1231  * not required to be done under cpu_hotplug_lock, but that's a different