smpboot_unregister_percpu_thread
smpboot_unregister_percpu_thread(&wti_threads);
smpboot_unregister_percpu_thread(&vmbus_irq_threads);
smpboot_unregister_percpu_thread(&vmbus_irq_threads);
void smpboot_unregister_percpu_thread(struct smp_hotplug_thread *plug_thread);
EXPORT_SYMBOL_GPL(smpboot_unregister_percpu_thread);