Re: pud_bad vs pud_bad

[Jeremy Fitzhardinge]

Ingo Molnar wrote:
> * Jeremy Fitzhardinge <jeremy@xxxxxxxx> wrote:
>
>   
> > I'm looking at unifying the 32 and 64-bit versions of pud_bad.
> >
> > 32-bits defines it as:
> >
> > static inline int pud_bad(pud_t pud)
> > {
> > 	return (pud_val(pud) & ~(PTE_PFN_MASK | _KERNPG_TABLE | _PAGE_USER)) != 0;
> > }
> >
> > and 64 as:
> >
> > static inline int pud_bad(pud_t pud)
> > {
> > 	return (pud_val(pud) & ~(PTE_PFN_MASK | _PAGE_USER)) != _KERNPG_TABLE;
> > }
> >
> >
> > I'm inclined to go with the 64-bit version, but I'm wondering if there's 
> > something subtle I'm missing here.
> >     
>
> Why go with the 64-bit version? The 32-bit check looks more compact and 
> should result in smaller code.
>   

Well, its stricter.  But I don't really understand what condition its 
actually testing for.

   J
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