God bless Paul E. McKenney, whose 2004 dissertation put on a rigorous footing the grubby claims of many foul patents. RCU, as it is commonly understood to mean, exploits atomicity of aligned pointer writes to provide high-performance (pretty much optimal for a heavy reader bias) reader-writer locks.
The liburcu project of the LTTng (Linux Trace Toolkit Next Generation) effort is a userspace RCU library.
- "Introduction to Read-Copy Update" by Paul McKenney
- "What is RCU, Fundamentally?" by Paul McKenney and Jonathan Walpole on LWN 2007-12-17
- "What is RCU?" by Paul McKenney, extending the previous
- "The Design of Preemptible RCU" by Paul McKenney on LWN 2007-10-08
- "Priority-Boosting RCU Read-Side Critical Sections" by Paul McKenney on LWN 2007-02-05