At the end of
the AOS work circa 1996, most of the kernel was 4.4,
except for the network stack which was 4.3-Reno, and the VM system which
was still 4.3 (hence no mmap).
This happened outside of IBM, didn't it? What prevented the rest of the VM
code being ported?
Most - if not all - the AOS work was done by Roger Florkowski and Mark
Dapoz, and Roger was definitely working for IBM at that time.
I think time was limiting factor, but also Roger was not really wanting
to port the Mach VM to AOS due to the RT MMU limitations - in
particular, there is no way for multiple virtual addresses to point to
the same page, so you need to keep evicting/switching mappings when you
want a page to be available to the kernel and the currently running
userland process. That was fixed in the POWER MMU.
I vaguely remember Metaware being somewhat religiously
extreme, but again
the details are fuzzy now. Was there some kind of ecclesiastical reference
in the man page?
I'm afraid that doesn't ring any bell.
Miod