[TUHS] CMU Mach sources?

Larry McVoy lm at mcvoy.com
Thu Jun 27 11:02:25 AEST 2019


On Wed, Jun 26, 2019 at 05:22:05PM -0700, Chris Hanson wrote:
> On Jun 26, 2019, at 1:21 PM, Larry McVoy <lm at mcvoy.com> wrote:
> > 
> > I also agree with whoever said the Mach guys were trying out all sorts
> > of different ideas, that's cool.  What's not cool is that when those
> > ideas didn't pan out they left in all the substrate that had proven to
> > be not needed.
> 
> It seems like you???re still missing the point.

I'm not missing anything.  Go read this:

https://www.cs.ubc.ca/~norm/508/2009W1/mach_usenix86.pdf

It talks about how simple Mach is, how it is going to be what Unix
wanted to be but Unix got too complicated.  Etc.  It sounds fantastic,
too good to be true and that's exactly what the code is.  You can go
on all you want about all the cool research it enabled, which I've not
disputed other than to say I didn't see much work out.  But OK, cool
research vehicle, got it.

What it is not is the simple awesome system that the papers described.

I was super stoked when I read that initial Mach paper, it seemed like
they wanted to clean up Unix and they had a plan.  I was very hopeful
that they were doing that, I agreed with their statements in section 2.

Anyone who has read the code would have a hard time reconciling their
code with the picture they painted in their papers.  And indeed, the
Mach supporters have said nothing about the code, other than to say it
is a research system and you can't expect clean code.  

If it had been advertised as that you wouldn't hear a peep out of me.

But it was advertised as a clean up of poor choices in Unix, it was
advertised as simple and clean.  It is anything but that.

I've got no problem with prototypes so long as it is clear that's what
it is.  My disappointment with Mach is I thought they were cleaning
things up, that's what they said, that's not what they delivered.

My beef is with their false advertising.  If they had advertised that
this was a research system for exploring OS research, not a production
ready system, I'd have been fine.  That's not how I read the Mach papers.
They made promises that they didn't deliver.  

With that, I'm done on this topic.  I'm not going to convince some people
of what I think, and they are not going to convince me of what I think.


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