the system calls that are not currently in the name space are those that do not distribute

(and there have been a few things in the name space that don't distribute and are troublesome).

segbrk doesn't distribute. rfork doesn't distribute. you can have a control request in a name space that operates on another process,

or creates another process, but that's not a system call by the calling process: it's a request to another process for it to do something

(possibly in the kernel domain, if there is one).