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From: avie@wb1.cs.cmu.edu (Avadis Tevanian)
Newsgroups: comp.sys.next
Subject: Re: Mathematica (NeXT 1.0)
Message-ID: <6239@pt.cs.cmu.edu>
Date: 23 Sep 89 00:04:21 GMT
References: <811smithw@yvax.byu.edu>
Organization: NeXT, Inc.
Lines: 36

In article <811smithw@yvax.byu.edu> smithw@yvax.byu.edu writes:
>
>  I have some interesting problems with mathematica to report.  I'd be
>interested to hear from anyone who has found others.  My machine is
>the 8 MB od only version.  I've noticed problems with memory before
>when running mathematica.  Today I tried finding the inverse of a
>certain symbolic matrix.  I watched the memory with ps -xva.  The program
>seems to hang onto disk space once it is used for swap and never lets go.
>When the thing really got going, it wouldn't even let me kill it with
>the skull and crossbones.  I got some failure panel for the abattoir.
>The swapfile increased in size to about 32 MB and when I was finally able
>to kill the process from shell it kept the space anyway (not quite the
>definition of swap is it? But wait...)

You are running into a problem where you just plain need more disk space
due to the size of Mathematica.  If you need to perform Mathematica
computations that use that much memory, then you should free up space
on your disk.  To do this, look at the printed release notes, which suggest
several files/directories that you may want to remove (e.g., TeX,
documentation, ...).

Also, the operating system is capable of shrinking the swapfile.  It will
shrink the size of the swapfile to correspond to the maximum page left
in the swapfile.  Unfortunately, what often happens is that a large
program will extend the swapfile to size n, another long lived background
process will cause a new page to be swapped to n+1, the original large
program will exit, but the swapfile will remain at size n+1 because it
is the largest.  Although the space freed in the middle of the file will
be reused, the fact of the matter is that the file is still large.  The sure
fire way to reclaim the swap space is to reboot the system, which truncates
the swapfile to a predetermined size (16 meg, I believe).
-- 
Avadis Tevanian, Jr.    (Avie)
Manager, Systems Software
NeXT, Inc.
avie@cs.cmu.edu or avie@NeXT.com