forth and virtual memory

http://varnish.projects.linpro.no/wiki/ArchitectNotes

This is an impressive read........they guy seems to do some smart
things by letting the os kernel do a lot of the work its designed for
and he does some tricks to avoid systems calls and keepign things in
filesystems that are expensive.

Can forth use this level of detail when it exists on linux?  How does
forth interact with virtual memory?

Do clever forthers use this kind of optimization?

Good stuff.