Re: (resend) Converting architectures to 4 level page tables

[Nick Piggin <nickpiggin@yahoo.com.au>]

David S. Miller wrote:
> On Sun, 23 Jan 2005 11:08:46 +1100
> Nick Piggin <nickpiggin@yahoo.com.au> wrote:
> 
> 
>>* replace
>>     #include <asm-generic/4level-fixup.h>
>>   in asm/pgtable.h with
>>     #include <asm-generic/pgtable-nopud.h>
> 
> 
> This breaks platforms like sparc64 because PTRS_PER_PMD is not
> a compile time constant.  It is actually dependant upon whether
> the current thread is using a 32-bit or 64-bit address space.
> 

Not sure I follow.... Oh, if it is just a matter of that
breaking the conditional compilation then OK, hmm.

These functions will simply never be called if the relevant
PTRS_PER_XXX is 1. Actually it is dependant on p?d_none
always being false.

So you shouldn't even need that runtime check there I think.
The #if was just a small space saving, but you could simply
remove that and be done with it I think. Or have I missed
something?