Path: utzoo!utgpu!watserv1!ria!csd.uwo.ca!crispin
From: crispin@csd.uwo.ca (Crispin Cowan)
Newsgroups: comp.arch
Subject: Re: Coprocessors - Business?
Message-ID: <2594@ria.ccs.uwo.ca>
Date: 28 Mar 91 18:55:18 GMT
References: <2892@megatek.megatek.uucp>
Sender: news@ria.ccs.uwo.ca
Organization: University of Western Ontario, London, Ont.
Lines: 88

In article <2892@megatek.megatek.uucp> mark@megatek.UUCP (mark thompson) writes:
>Whenever I read architecture manuals for (eg. the Moto 68000 series),
>they invariably support several coprocessors. Also invariably, one of
>those coprocessors is for floating point.

>Often, the other is an MMU or some other silly system controller.

>Has anyone tried to do something wonderful with one of the undedicated
>coprocessors, examples of wonderful being I/O channel controllers or a
>business instruction set?

In the Sylvan project, we built a tasking coprocessor for 68020s and
68030s for a multiprocessor.  The intent was to create a lightweight
tasking environment for a tightly-coupled multiprocessor, with
tightly-coupled performance and loosely-coupled semantics, so that
programs could be scaled up to distributed networks of computers.  This
achieved a loocal message passing cycle time (approx RPC) of 136
microseconds, relative to about 500-1000 in software-only message
passing kernels supporting similar task models.

The first two citations below describe Sylvan's implementation and
performance.  The following two are early proposals describing what
Sylvan should look like.

Crispin
-----
Crispin Cowan, CS grad student, University of Western Ontario
Work:  MC28-C, x3342 crispin@csd.uwo.ca
Home:  890 Elias St., London, Ontario, N5W 3P2
"If you want an operating system that is full of vitality and has a
great future, use OS/2."  --Andy Tanenbaum

@inproceedings
  (
    bur89,
    author = "F. J. Burkowski and G. V. Cormack and G. D. P. Dueck",
    title = "{Architectural Support for Synchronous Task
Communication}",
    booktitle = "Proceedings of the Third International Conference on
        Architectural Support for Programming Languages and Operating
        Systems",
    year = 1989,
    pages = "40-53",
    address = "Boston, MA",
    month = "April"
  )

@inproceedings
  (
    bur91,
    author = "F. J. Burkowski and Charles L. A. Clarke and Crispin Cowan
	 and Gordon J. Vreugdenhil",
    title = "{Performance Evaluation of the Sylvan Multiprocessor
	Architecture}",
    booktitle = "Proceedings of the Second Symposium on Experiences with
	Distributed and Multiprocessor Systems",
    year = 1991,
    pages = "165-184",
    address = "Atlanta, GA",
    month = "March"
  )

@inproceedings
  (
    bur85:honolulu,
    author = "F. J. Burkowski and D. Dyment",
    title = "{Sylvan: A Message-Based Multiprocessor Architecture}",
    booktitle = "Proc. 18th Hawaii International Conference On Systems
        Sciences",
    year = 1985,
    pages = "31-42",
    address = "Honolulu",
    month = "January"
  )

@inproceedings
  (
    bur85:knoxville,
    author = "F. J. Burkowski and G. V. Cormack and J. D. Dyment and
        J. K. Pachl",
    title = "{A Message-Based Architecture for High Concurrency}",
    booktitle = "Proc. 1st Conference on Hypercube Multiprocessors",
    year = 1985,
    pages = "27-37",
    address = "Knoxville, Tenessee",
    month = "August"
  )