I seem to recall that problems with pthreads, mySQL, etc. were related to       
not having ll/sc or an atomic store syscall on non-R4000 mips NetBSD            
systems.                                                                        
                                                                                
I wonder why you can't just use the memory system for synchronization -
there are probably a number of synchronization algorithms that would work,
and these wouldn't have the overhead of a system call,
                                                                                
Bob