At 04:54 PM 7/26/2000 +0200, Anders Magnusson wrote:
> > > The hard limit on VAXen is 24MB of data.  This is because the page
> > > table design on VAX consumes an incredible amount of memory, so
> > > increasing it will steal much static allocated memory.
> >
> > Seems to me the *right* fix for this is to make userland page tables
> > pageable (or at least swappable).
> >
>They _are_ pageable. The problem is the parts of the kernel page table
>that must map the user page tables, that must be in physical contiguous
>memory and therefore allocated at boot.

The system page table must be in physically contiguous memory; user
page tables only need system virtually contiguous memory (except for
the RTVAX).  I'd sacrifice RTVAX support for better pmap management.
--
Matt Thomas               Internet:   matt@3am-software.com
3am Software Foundry      WWW URL:    http://www.3am-software.com/bio/matt/
Cupertino, CA             Disclaimer: I avow all knowledge of this message