Newsgroups: comp.lang.lisp
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From: cracauer@wavehh.hanse.de (Martin Cracauer)
Subject: Re: cmu-lisp: GC lossage
Message-ID: <1996Apr18.101748.10289@wavehh.hanse.de>
Organization: BSD User Group Hamburg
References: <317193EF.5C1BD0FB@arch.su.edu.au>
Distribution: inet
Date: Thu, 18 Apr 96 10:17:48 GMT
Lines: 64

Thorsten Schnier <thorsten@arch.su.edu.au> writes:

>I am trying to run an evolutionary system in CMU LISP (17f on
>solaris). The genotypes in the ES are represented as lists,
>sometimes taking up quite a large block of data (the printed 
>representation of the data is about 20MB, the garbage collection
>reports >10 Mb). Unfortunately, after a while I run into the
>following error: 

>GC lossage.  No scavenge function for object 0x00000002
>LDB monitor
>ldb>
>EOF on something other than a tty.

>(the program is run as a batch job)

>This seems to be an internal CMUCL error, are there any patches 
>available, or do you know of anything else I can do?

Is it possible that you are out of paging space? Try swapinfo.

You might try to reach the limit where CMUCL starts GC, for example in
your ~/init.lisp

(setq *bytes-consed-between-gcs* (* 1024 1024 4))
or even higher. Not a solution, but it might bring the system to run.

You might try a different platform. Sparc/SunOS still looks like the
most decent platform for CMUCL.

Paul Werkowski's port of CMU CL to Intel-based PCs has a completly
different GC, in case you have a FreeBSD or NetBSD/i386 machine. If
that solves your problem, it might be possible to build a
Sparc/Solaris binary with this GC implementation.

>The program works in GCL, but unfortunately GCL spends _very_
>much time during GCs, making it about 20-30 times slower than
>CMUCL.

If all fails and GC is really the primay performance problem, you
might try Clisp as well, which has a GC that is faster in some
situations than that of GCL. 

>BTW: I tried to check for new information on CMULISP at
>lisp-sun1.slisp.cs.cmu.edu, but I got a '550 Can't set guest privileges'
>error. Isn't that supposed to be the new distribution site?

I use

ftp://ftp.cs.cmu.edu/afs/cs.cmu.edu/project/clisp/release

although I noticed that this URL doesn't work with certain procy
caches (and/or Netscape Navigator's ftp implementation). Try a
standalone ftp client.

Some information for CMUCL is availiable from my home page. I'm
preparing a collection of all patches I've seen since the last
release. None of them touches the GC.

Martin
-- 
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
Martin Cracauer <cracauer@wavehh.hanse.de>  -  BSD User Group Hamburg
BSD, Lisp and other programming info http://www.bik-gmbh.de/~cracauer
