[TUHS] SunOS vs Linux

Kirk McKusick mckusick at mckusick.com
Sun Jan 8 16:10:22 AEST 2017

> Date: Fri, 6 Jan 2017 20:09:18 -0700
> From: Warner Losh <imp at bsdimp.com>
> To: "Greg 'groggy' Lehey" <grog at lemis.com>
> Cc: Clem Cole <clemc at ccc.com>, The Eunuchs Hysterical Society
>         <tuhs at tuhs.org>
> Subject: Re: [TUHS] SunOS vs Linux
>> On Friday,  6 January 2017 at  9:27:36 -0500, Clem Cole wrote:
>> I think that if SunOS 4 had been released to the world at the right
>> time, the free BSDs wouldn't have happened in the way they did either;
>> they would have evolved intimately coupled with SunOS.
> With the right license (BSD), I'd go so far as to saying there'd be no
> BSD 4.4, or if there was, it would have been rebased from the SunOS
> base... There were discussions between CSRG and Sun about Sun donating
> it's reworked VM and VFS to Berkeley to replace the Mach VM that was
> in there... Don't know the scope of these talks, or if they included
> any of the dozens of other areas that Sun improved from its BSD 4.3
> base... The talks fell apart over the value of the code, if the rumors
> I've heard are correct.
> Warner

Since I was involved with the negotiations with Sun, I can speak
directly to this discussion. The 4.2BSD VM was based on the
implementation done by Ozalp Babaoglu that was incorporated into
the BSD kernel by Bill Joy. It was very VAX centric and was not
able to handle shared read-write mappings.

Before Bill Joy left Berkeley for Sun, he wrote up the API
specification for the mmap interface but did not finish an
implementation. At Sun, he was very involved in the implementation
though did not write much (if any) of the code for the SunOS VM.

The original plan was to ship 4.2BSD with an mmap implementation,
but with Bill's departure that did not happen. So, it fell to me
to sort out how to get it into 4.3BSD. CSRG did not have the
resources to do it from scratch (there were only three of us).
So, I researched existing implementations and it came down to
the SunOS and MACH implementations. The obvious choice was SunOS,
so I approached Sun about contributing their implementation to
Berkeley. We had had a lot of cooperation about exchanging bug
fixes, so this is not as crazy as it seems.

The Sun engineers were all for it, and convinced their managers
to push my request up the hierarchy. Skipping over lots of drama
it eventually got to Scott McNealy who was dubious, but eventually
bought into the idea and cleared it. At that point it went to the
Sun lawyers to draw up the paperwork. The lawyers came back and
said that "giving away SunOS technology could lead to a stockholder
lawsuit concerning the giving away of stockhoder assets." End of
discussion. We had to go with MACH.

	Kirk McKusick

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