doesnt vms do something like this for some of their equivalent of shared 
libs? 
isildur

On Tue, 1 Oct 2002, Wojciech Puchar wrote:

> > >
> > > Shared libraries and the dynamic linker *already* share in this way...
> >
> > OTOH mapping libc at a fixed and reserved address would, on some
> > architectures at least, allow the code pages to use global TLB
> > entries.  This would mean that cache lines could be shared between
> > different processes.
> 
> and lot of time saved of ld_elf.so work.
> 
>