1. "However, a separate synchronization mechanism must be supplied to keep the writers from
destructively interfering with each other, as noted in the first list above."
Maybe I miss or repeat something, but serious downsize of this upgrade-to-write seems to be in
this possibly stale value of the search got as an RCU reader, which would always(?) require
2. This example:
"RCU is a Restricted Reference-Counting Mechanism
Regardless of these restrictions, the following code can safely delete p:
2 p = head;
3 head = NULL;
5 synchronize_rcu(); /* Wait for all references to be released. */
should probably promote rcu_assign_pointer() more...
3. "And" maybe one more tiny fix:
"RCU is a Bulk Reference-Counting Mechanism
starting and I/O and released [...]"