number of updates per grace period.
9. All RCU list-traversal primitives, which include
- rcu_dereference(), list_for_each_rcu(), list_for_each_entry_rcu(),
+ rcu_dereference(), list_for_each_entry_rcu(),
list_for_each_continue_rcu(), and list_for_each_safe_rcu(),
must be either within an RCU read-side critical section or
must be protected by appropriate update-side locks. RCU