On Mon, Mar 17, 2014 at 03:07:30PM -0700, Andrew Morton wrote: > On Mon, 17 Mar 2014 18:51:58 +0000 Steve Capper <steve.capper@xxxxxxxxxx> wrote: > > > Introduce huge pte versions of pte_page, pte_present and pte_young. > > This allows ARM (without LPAE) to use alternative pte processing logic > > for huge ptes. > > > > Where these functions are not defined by architectural code they > > fallback to the standard functions. > > > > Signed-off-by: Steve Capper <steve.capper@xxxxxxxxxx> > > --- > > Hi, > > I'm resending this patch to provoke some discussion. > > > > We already have some huge_pte_ style functions, and this patch adds a > > few more (that simplify to the pte_ equivalents where unspecified). > > > > Having separate hugetlb versions of pte_page, present and mkyoung > > allows for a greatly simplified huge page implementation for ARM with > > the classical MMU (which has a different bit layout for huge ptes). > > Looks OK to me. One thing... > > > --- a/include/linux/hugetlb.h > > +++ b/include/linux/hugetlb.h > > @@ -353,6 +353,18 @@ static inline pte_t arch_make_huge_pte(pte_t entry, struct vm_area_struct *vma, > > } > > #endif > > > > +#ifndef huge_pte_page > > +#define huge_pte_page(pte) pte_page(pte) > > +#endif > > This #ifndef x #define x thing works well, but it is 100% unclear which > arch header file is supposed to define x if it wishes to override the > definition. We've had problems with that in the past where different > architectures put it in different files and various breakages ensued. > > So can we decide which arch header file is responsible for defining > these, then document that right here in a comment and add an explicit > #include <asm/that-file.h>? Thanks Andrew, Yes I see your point, this could quickly become unstable. I'll see how these look in include/asm-generic/hugetlb.h instead. Cheers, -- Steve -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>