> If it's laid out that way, then that's a hack, and therein lies the real
> problem.  :-)

It's not more of a hack than any other design decision.  Remember that not
all of the world is Linux.

> A much better answer is to deal with it that way only for
> initial bootstrap (until VM is up), then set aside a whole PTEG for kernel
> space (say, PTEG 0), but map exactly what is needed for the kernel.  Then
> when you load a module, add another PTE into group 0.

Huh?  AFAICT, a PTEG contains just 8 mappings, so you can map at most
32 KB with one PTEG.  Not too much :-).

> The Mach VM
> implementation under MkLinux does something along these lines, as far as I
> can tell from trivial perusal.  And we all know how big its "modules" 
> (servers) can be.  :-)

I don't have a clue.  And I don't give a damn either.

> Yes, but you wouldn't _want_ all functions to be compiled that way -- just
> the ones that cross module/kernel boundaries.  It really should be done on
> a function by function basis if you elect to use this method, but fixing
> the kernel mapping is probably easier, and much more flexible.  :-)

Why not?  1. it will be done only for LKMs, and 2. it's more or less
done this way for the PowerOpen ABI on all function calls, so it probably
isn't too bad.

Ciao,
Wolfgang
-- 
ws@TooLs.DE     Wolfgang Solfrank, TooLs GmbH 	+49-228-985800