[Sbcl-help] How to set dynamic-space-start and dynamic-space-end (and other parameters in parms.lisp) to allow use of more than 8GB RAM on x86-64?

[Alistair G. <ali...@gm...>]

I am using sbcl 1.0.29 for data analysis on ubuntu 9.10 Linux x86-64
with 96GB RAM.

sbcl dies at about 8GB of heap usage, regardless of the what I specify
for --dynamic-space-size on the command line.

I notice that 8GB is the same number as determined by
dynamic-space-start and dynamic-space-end in
src/compiler/x86-64/parms.lisp:

(progn
  (def!constant read-only-space-start     #x20000000)
  (def!constant read-only-space-end       #x200ff000)

  (def!constant static-space-start        #x20100000)
  (def!constant static-space-end          #x201ff000)

  (def!constant dynamic-space-start   #x1000000000)
  #!-openbsd
  (def!constant dynamic-space-end     #x11ffff0000)
  #!+openbsd
  ;; This is lower on OpenBSD to allow SBCL to run under the default
  ;; 512M data size limit.
  (def!constant dynamic-space-end     #x101bcf0000)

  (def!constant linkage-table-space-start #x20200000)
  (def!constant linkage-table-space-end   #x202ff000)

  (def!constant linkage-table-entry-size 16))


Therefore, I would like to rebuild sbcl after modifying the settings
in parms.lisp to allow the full use of my 96GB RAM. What exactly
should I change?

I suspect that I can just lower dynamic-space-start, but how low can I
set it to? Do I need to change anything else?

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