Overhead of using locks instead of atomic intrinsics

Question

Does anyone know of published benchmarks of the overhead of locking instead of relying on certainly atomic operations/intrinsics (on a multiprocessor system) only?

I

Answer 1

I don't know where specific studies are, but you are unlikely to find a definitive locks-are-better answer anywhere. It depends very much on how you use them, how much contention they are subject to, and what you are using the primitives for. If all you want to do is increment numbers, then yes, you'll probably find atomic primitives to be faster than locks, but if you want to perform multi-word compare and swap, or complex updates to tree structures, etc., you'll find that the lock-free code is not only much more complex and difficult to debug, but that the performance advantages over a well-designed lock-based implementation are inconclusive at best, and hardly worth the substantial increase in complexity. TANSTAAFL.