On Mon, 2 Jan 2006, Chapman Flack wrote:
> Out of curiosity, anybody have an idea what fraction of NetBSD
> supported MP architectures (maybe weighted by prominence?) have a
> cmpxchg instruction (or a loadlinked/storeconditional, lwarx/stwcx
> or other feature that can be used to the purpose)?

I don't, but maybe you want to start your research from this page:
http://www.netbsd.org/developers/features/


  - Hubert