[TUHS] Ideas for a Unix paper I'm writing
tim.newsham at gmail.com
Tue Jun 28 11:00:57 AEST 2011
my two cents:
- system unity - the system was designed from the ground up,
including design tools such as assembler and language
and compiler, by a small group of people. This allowed
the designers to get great unity.
- Utility - the designers used the system, and made sure the system
they built was useful for them. This ensured that it was also useful
for other people like them, and it turns out for lots of other people
less like them, too.
- simplicity - perhaps a result of the small team of people, the system
was understandable. The designers sometimes chose simplicity over
generality or even elegance (ie. EAGAIN, making callers job harder, but
simplifying kernel). I think there's a great deal of pragmatism here that
worked well with the unity. They knew the whole system and were able
to see where to give a little and where to take a little.
- Open design - the fact that unix came with readable and understandable
documentation and source code helped it immensely! Users were free
to take the system, study it, change it and tailor it to their needs. Others
were able to imitate and extend (for better or worse).
and like any popular system, a dash of good luck.
On Mon, Jun 27, 2011 at 2:11 PM, Warren Toomey <wkt at tuhs.org> wrote:
> All, IEEE Spectrum have asked me to write a paper on Unix to celebrate the
> 40th anniversary of the release of 1st Edition in November 1971. I'm after
> ideas & suggestions!
> I think my general thrust is that Unix is an elegant design, and the
> design elements are still relevant today. The implementation is mostly
> irrelevant (consider how much the code has changed from assembly -> C,
> from the simple data structures in V7 through to current BSD), but the
> original API is classic. Note that about 28 of the 1st Ed syscalls are
> retained in current BSDs and Linux, and with the same syscall numbers.
> I'm having some trouble thinking of the right way to explain what is
> an elegant design at the OS/syscall level, so any inspirations/ideas
> would be most welcome. I might highlight a couple of syscall groups:
> open/close/read/write, and fork/exec/exit/wait.
> If you have any references/URLs you think I should look at, please
> pass them on to me.
> I'm also trying to chase down some quotes; my memory seems to be failing me
> but I'm sure I've seen these somewhere:
> - in a paper, I think by Thompson & Ritchie, where they assert that the
> kernel should provide no more than the most minimal services to the
> userland programs. I thought this was the CACM paper, but I can't spot
> this bit. Maybe it's in Thompson's preface to the Lions Commentary,
> of which my copy is elsewere at present.
> - I'm sure I remember someome (Kernighan?) say that Ritchie encouraged
> them to espouse the use of processes as context switching was cheap,
> but later measurements showed that in fact it wasn't that cheap in
> the early versions of Unix.
> Anyway, if you can think of good ideas/references about the elegance of
> Unix, especially from the design perspective, I would much appreciate them.
> TUHS mailing list
> TUHS at minnie.tuhs.org
Tim Newsham | www.thenewsh.com/~newsham | thenewsh.blogspot.com
More information about the TUHS