wakeme_after_rcu
void wakeme_after_rcu(struct rcu_head *head);
call_srcu(ssp, &rs.head, wakeme_after_rcu);
__call_srcu(ssp, &rcu.head, wakeme_after_rcu, do_norm);
needwake = (func == wakeme_after_rcu) ||
EXPORT_SYMBOL_GPL(wakeme_after_rcu);
(crcu_array[i])(&rs_array[i].head, wakeme_after_rcu);