There were others that also did Unix SMP (some on BSD). Encore offering
BSD, AT&T or Mach (their storage arrays contained a core cluster of 2 SMP
nodes, later bought by Sun); Sequent; and Pyramid dualPort OS/x around
1985/87.

Pyramid had dual-CPU 90Mx/98x and I think a single lock (memory fades a
bit). Later more fine-grained around the time of the 1-CPU 9810 up to 4-CPU
9845. Before eventually going to MIPS CPU SMPs, then adding MPP to the MIPS
range.

IIRC, this was on a mostly-BSD 4.2/4.3 base(?) when I worked in the Pyramid
team producing their POSIX threads library & parallel debugger (late 80s).


Although Pyramid did have their ATT "unverse" incorporated into the same
Unix, hence dualPort. So there was a bunch of SVR3/4 support included:
extra set of syscalls; u.u_universe to select which; conditional symbolic
links using u.u_universe to resolve to UCB or ATT paths for lib & bin dirs;
merged TTY driver with a superset of stty attributes; etc.

Apollo Domain had something similar to conditional symbolic links, but
expanding environment variables to determine the target path. Different
flexibility/overhead tradeoff.

I wonder if any dualPort or DC/OSx Pyramid source survives...
or the old Australian promo poster from PTC BURP, where I got elected the
PHB, standing like a dork at the console of a 9840 cabinet (I think I was
the only one in a long sleeve shirt that day, and had an emergency tie at
the back of my desk drawer, so...)


On Tue, 4 Jan 2022, 08:04 Greg 'groggy' Lehey, <grog@lemis.com> wrote:

> On Monday,  3 January 2022 at 15:44:11 -0800, Larry McVoy wrote:
> > On Mon, Jan 03, 2022 at 05:21:51PM -0600, Doug McIntyre wrote:
> >> On Mon, Jan 03, 2022 at 04:15:08PM -0500, Dan Cross wrote:
> >> I'd agree, 2.4 was pretty slow and chunky, 2.5 was alright, but 2.5.1
> was quite usable and stable.
> >> Also by this time, the hardware was going in directions that SunOS
> wouldn't keep up with.
> >
> > Yeah, Doug is right, SunOS was pretty simple, it didn't really take
> advantage
> > of SMP, Greg Limes tried to thread it but it was too big a job for one
> guy.
> >
> > That's not to say that SunOS couldn't have evolved into SMP, I'm 100%
> > sure it could have.  It just didn't.  It's a shame.
>
> An interesting question.  I had always thought that SMP was (one of?)
> the technical reasons why Sun moved from a BSD to a System V base.
> Since then, of course, we've done lots of work on SMP support for at
> least FreeBSD.  Does anybody have an overview of how good the support
> is compared to modern Solaris?  Is there any intrinsic reason why one
> should be better than the other?
>
> Greg
> --
> Sent from my desktop computer.
> Finger grog@lemis.com for PGP public key.
> See complete headers for address and phone numbers.
> This message is digitally signed.  If your Microsoft mail program
> reports problems, please read http://lemis.com/broken-MUA.php
>