Benevolent Dictatorship

Rodrigo Ventura yoda@isr.ist.utl.pt
Fri, 20 Mar 1998 19:29:36 +0100 (GMT+0100)


>>>>> "Rainer" == Rainer Joswig <joswig@lavielle.com> writes:

    >> CMUCL: as I said before, I found it too heavy. Ok, it compiles
    >> directly to assembly, and this is great for speed, but the GC is too
    >> slow, it GC's too much. I think it's too huge to serve as a base for a
    >> LispOS.

    Rainer> People are working to improve GC (by having a generational GC).

    Rainer> When it comes to size, I don't care about that too much nowadays.
    Rainer> My home PC has 128 MB RAM, my next Laptop will have > 200 if
    Rainer> possible. RAM is cheap these days. Don't waste memory if
    Rainer> not necessary, but this is not my primary concern these days.

        Huge RAM requirements are not satisfied with cheap RAM. Wanna
see why? Well, you have Windows95 and the Office, you have Netscape,
you have statically linked Motif, etc. Why are Object Oriented
solutions so slow? Because they waste alot of memory, just to provide
the programmer extra funconality, which becomes almost useless
afterwards.

        What I mean is that more memory induces more CPU time browsing
though it. Means more time loading, GC'ing, etc. It's not just the
SIMM (or DIMM) price, but rather the whole system performance. Of
course there is such thing as time-memory trade-off, but this is not
the case.

    Rainer> Currently CMU CL is the only choice for a CL-based system (IMHO).
    >> 
    >> Why do you say "only"?

    Rainer> Because it is the only system with a native code compiler.
    Rainer> And some people are still hacking with CMU CL.

        My opinion fall down alot when I tried a trivial factorial
function, and observed CMUCL core dumping! How can a factorial
function core-dump the CL system with large integers??? And when I
tried a agent society simulation I developed using CLISP, it kept on
GC'ing continuously, and ended-up going nowhere. Another thing I
didn't like was the hard-coded directory locations.

        Regards,

-- 
--

*** Rodrigo Martins de Matos Ventura, alias <Yoda>
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***   Instituto de Sistemas e Robotica, Polo de Lisboa
***    Instituto Superior Tecnico, Lisboa, Portugal
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