goto end;
}
- /*
- * For all RCU flavors except QSBR, we need to explicitly mark
- * RCU read-side critical sections with rcu_read_lock() and
- * rcu_read_unlock(). They can be nested. Those are no-ops for
- * the QSBR flavor.
- */
- rcu_read_lock();
-
/*
* RCU traversal of the linked list.
*/
cds_list_for_each_entry_rcu(node, &mylist, node) {
printf("Value: %" PRIu64 "\n", node->value);
}
- rcu_read_unlock();
/*
* Removing nodes from linked list. Safe against concurrent RCU
*/
cds_list_for_each_entry_safe(node, n, &mylist, node) {
cds_list_del_rcu(&node->node);
+ /*
+ * call_rcu() will ensure that the handler
+ * "rcu_free_node" is executed after a grace period.
+ * call_rcu() can be called from RCU read-side critical
+ * sections.
+ */
call_rcu(&node->rcu_head, rcu_free_node);
}
rcu_thread_online();
+ /*
+ * We can also wait for a quiescent state by calling
+ * synchronize_rcu() rather than using call_rcu(). It is usually
+ * a slower approach than call_rcu(), because the latter can
+ * batch work. Moreover, call_rcu() can be called from a RCU
+ * read-side critical section, but synchronize_rcu() ensures the
+ * caller thread is offline, thus acting as a quiescent state.
+ */
+ synchronize_rcu();
+
/*
* Waiting for previously called call_rcu handlers to complete
* before program exits, or in library destructors, is a good