__wake_up_sync_key
void __wake_up_sync_key(struct wait_queue_head *wq_head, unsigned int mode, void *key);
__wake_up_sync_key((x), TASK_INTERRUPTIBLE, poll_to_key(m))
__wake_up_sync_key(&parent->signal->wait_chldexit,
EXPORT_SYMBOL_GPL(__wake_up_sync_key);
__wake_up_sync_key(wq_head, mode, NULL);