[LAD] concurrent access on smp

[Paul Giblock]

> If your data structures and their use require locking, which you would like
> to avoid, there is a concept called Read-Copy-Update which is for example
> heavily used in the kernel and is also available as an userspace library
> (http://lttng.org/urcu).

Yes, the RCU approach is quite effective.  However, better to not call
it that since IBM has a patent on it last I checked.

-- Paul