Re: Linux 2.6.26-rc1 - pgtable_32.c:178 pmd_bad

[Linus Torvalds]

On Tue, 6 May 2008, Ingo Molnar wrote:
> 
> hm, the main objection was about whether to turn PAGE_SIZE from unsigned 
> into signed though - and that we didnt do.

No it wasn't.

The main objection was that you SHOULD NOT USE PAGE_SIZE_MASK AT ALL!

You should have used a pagetable-specific macro, becuse PAGE_MASK is 
simply fundamentally WRONG, and has absolutely nothing to do with the PFN 
bits, whether sign-extended or not!

The fact is, the page frane number bits are *not* ~PAGE_MASK or anything 
like that. They share only the low bits - not the high bits.

			Linus
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