Re: bisected boot regression post 2.6.25-rc3.. please revert

From: Jeremy Fitzhardinge
Date: Sun Mar 09 2008 - 22:46:00 EST


Linus Torvalds wrote:
So I would *very* strongly instead argue:

- "unsigned long" is the native kernel type for all address manipulation, and thus "PAGE_SIZE" and "PAGE_MASK" should continue to have that type.

- anything that uses any other type without explicitly making sure it's safe is mis-using those macros. IOW, PAGE_MASk was *never* a type that had anything what-so-ever to do with page table entry bits, and this is purely a page table entry issue!

Yes. PTE_MASK already exists for masking the address bits out of a pte. It should have the type pteval_t, which will deal with the PAE case cleanly. It should also only have the middle pfn bits set, so that _PAGE_NX is also not included.

It's currently defined in terms of PHYSICAL_PAGE_MASK, which 1) is only used to define PTE_MASK, and 2) defined (wrongly) in terms of PAGE_MASK (though __PHYSICAL_MASK is correctly defined).

J
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