While nobody asked, just two notes:

1. We would have a generic syscall for setting affinity with CPU set anyway,
   so it's more a question how the API would look in the library.

2. Solaris implements functionality of processor-sets in the kernel to get
   such stuff like pset_getloadavg(3). While this is flexible, I would rather
   like to keep that light, and use simple playing with bits in the library.

-- 
Best regards,
Mindaugas
www.NetBSD.org