Can anyone explain ..

[Jonas Nygren]

I have just compiled sicstus prolog on the DECstation3100 and ran into  a
strange beahviour. When compiling the wam-engine, which is implemented as
one 800 lines long procedure, 'cc' complained and  asked me to define an
 -Olimit 0f at least 2772. I declared it 3000 and tried to recompile to get
an optimized version of the wam but had no luck. My machine only has the
minimum 8 Mbytes so I tried to run this compilation in single user mode. 
Here follows the result of two seperate 'ps -axv' which I did to document
the situation:

  PID TT STAT  TIME SL RE PAGEIN SIZE  RSS  LIM TSIZ TRS %CPU %MEM COMMAND
 1786 co P     1:06  0  4  19014 6756  388   xx  408  12  0.0  6.9 uopt1.31
 1793 co R     0:00  0  2      7  296  256   xx  104  88 29.9  6.0 ps
    1 ?  IW    0:01 99 99    552  260    0 5904   68   0  0.0  0.0 init
 1773 co S     0:00  2  4    356   84   60   xx  152 108  0.0  3.0 csh
 1754 co IW    0:00 99 99     93   16    0 5904   36   0  0.0  0.0 sh
    2 ?  D     0:18  4 99      0 1632    0 5904    0   0  0.0  0.1 pagedaemon
 1782 co IW    0:00 99 99      7   36    0   xx   68   0  0.0  0.0 cc1.31
    0 ?  D     0:12  4 99      0    0    0 5904    0   0  0.0  0.1 swapper


  PID TT STAT  TIME SL RE PAGEIN SIZE  RSS  LIM TSIZ TRS %CPU %MEM COMMAND
 1786 co P     3:27  0  3  91115 7396  368   xx  408   4  0.0  6.4 uopt1.31
 1797 co R     0:00  0  2      7  296  256   xx  104  88  8.5  6.0 ps
    1 ?  IW    0:01 99 99    552  260    0 5904   68   0  0.0  0.0 init
 1773 co S     0:01  1  3    470   84   60   xx  152 100  0.0  2.8 csh
 1754 co IW    0:00 99 99     93   16    0 5904   36   0  0.0  0.0 sh
    2 ?  D     0:23  3 99      0 1632    0 5904    0   0  0.0  0.1 pagedaemon
 1782 co IW    0:00 99 99      7   36    0   xx   68   0  0.0  0.0 cc1.31
    0 ?  D     0:12  3 99      0    0    0 5904    0   0  0.0  0.1 swapper

As you can see there is an awful lot of PAGEIN's done but also a lot of 
real physical memory available. 'uopt1.31' only use 6.4% of the memory
and other processes are only using a total of 9%. WHY don't uopt use
some of the 80+% mem available? What can I be doing wrong? Is there any
parameter I could tune to get a different beahviour?

I really would like the PMAX to show off well in any prolog benchmarks
so I hope somebody out there have any tips on how to allow uopt to use more 
memory so that I can get an optimized version of the wam procedure which
is the heart of sicstus prolog.

Thanx in advance