rcu_nocb_lock
rcu_nocb_lock(rdp);
rcu_nocb_lock(my_rdp); /* irqs already disabled. */
static void rcu_nocb_lock(struct rcu_data *rdp);
rcu_nocb_lock(rdp);
rcu_nocb_lock(rdp);
rcu_nocb_lock(rdp);
rcu_nocb_lock(rdp); // Rare during call_rcu() flood.