+void rcu_barrier(void);
+
+ Wait for all call_rcu() work initiated prior to rcu_barrier() by
+ _any_ thread on the system to have completed before rcu_barrier()
+ returns. rcu_barrier() should never be called from a call_rcu()
+ thread. This function can be used, for instance, to ensure that
+ all memory reclaim involving a shared object has completed
+ before allowing dlclose() of this shared object to complete.
+