Re: pmd_alloc, pte_alloc, Was Re: 2.4.3 and Alpha

[Paul Mackerras]

[e-mail] writes:

>   Basically in the pmd, it would seem that the current design in 2.4.3 forces
> you to have pointers in there. Currently in our source we're using offsets
> instead of a 64 bit pointer... this of course saved us from having to alloc 2
> contiguous pages in memory. 

Nope, the representation of the pgd/pmd/pte entries is entirely up to
you (us :).  The pmd entries for example are accessed through pmd_none,
pmd_present, pte_offset, etc., and are set with pmd_populate.  Those
functions are all defined in asm/pgtable.h and asm/pgalloc.c.  So you
can make the representation whatever you like as long as those
functions all do the right thing.  Same goes for the pgd and pte
levels.

Paul.