[Self-interest] memory systems in Linux and Mac virtual machines

[Jecel Assumpcao Jr]

Russell,

> I do get an early crash when I try your code on ourself.io 
> 
> Admittedly I am running the linux VM under the FreeBSD
> emulation layer, so it is quite possibly related to that. 

I have not looked at the sources for the VM in the past couple of
decades, but I remember Squeak having similar problems. Those were
normally related to having pointers treated as signed integers which
messed up some comparisons.

A complicating factor was at some point Linux stopped allocating space
from address 0 up and started giving applications random locations in
virtual address space in the name of security. That made heaps that
previous seemed to work at up to 2GB suddenly cause problems at much
smaller sizes in ways that were hard to reproduce.

Self originally ran on SunOS (I think), so a native FreeBSD port might
be a reasonable project. But it might be too much for a Google Summer of
Code student.

-- Jecel