On Mon, Oct 11, 2021 at 3:09 AM George Michaelson <ggm@algebras.org> wrote:

> My memory is, that at least one model (OSF/1) required reboot, because
> it did some intermediate call optimisation to remove/elide indirect refs.

Hmm, as far as I know,/my experience was that with OSF/1 was fine with
shared libs, no reboot needed (at least on the 386 reference -- I never
tried it on the PMAX].
I suspect you might be thinking about drivers and kernel modules, which
were not nearly as clean - particularly in the pure (Mach 3.0 based) OSF/1
microkernel implementation [which was hardly 'micro' in size].   IIRC Rob's
new memory system code for SunOS was one of the first UNIX implementations
that supported loadable kernel modules.

Anyway, for the original OSF/1, I really don't think shared libs caused a
reboot using the original CMU Mach 2.5 memory code, but adding things to
the kernel did. I know that was changed with the MMU rewrite for Tru64, but
I think it was also done in later versions of the OSF RI kernel (but I've
forgotten).