From 62eede62dafb4a6633eae7ffbeb34c60dba5e7b1 Mon Sep 17 00:00:00 2001 From: Hugh Dickins Date: Mon, 21 Sep 2009 17:03:34 -0700 Subject: mm: ZERO_PAGE without PTE_SPECIAL Reinstate anonymous use of ZERO_PAGE to all architectures, not just to those which __HAVE_ARCH_PTE_SPECIAL: as suggested by Nick Piggin. Contrary to how I'd imagined it, there's nothing ugly about this, just a zero_pfn test built into one or another block of vm_normal_page(). But the MIPS ZERO_PAGE-of-many-colours case demands is_zero_pfn() and my_zero_pfn() inlines. Reinstate its mremap move_pte() shuffling of ZERO_PAGEs we did from 2.6.17 to 2.6.19? Not unless someone shouts for that: it would have to take vm_flags to weed out some cases. Signed-off-by: Hugh Dickins Cc: Rik van Riel Reviewed-by: KAMEZAWA Hiroyuki Cc: KOSAKI Motohiro Cc: Nick Piggin Cc: Mel Gorman Cc: Minchan Kim Cc: Ralf Baechle Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- arch/mips/include/asm/pgtable.h | 10 ++++++++++ 1 file changed, 10 insertions(+) (limited to 'arch/mips/include/asm/pgtable.h') diff --git a/arch/mips/include/asm/pgtable.h b/arch/mips/include/asm/pgtable.h index 1a9f9b257551..d6eb6134abec 100644 --- a/arch/mips/include/asm/pgtable.h +++ b/arch/mips/include/asm/pgtable.h @@ -76,6 +76,16 @@ extern unsigned long zero_page_mask; #define ZERO_PAGE(vaddr) \ (virt_to_page((void *)(empty_zero_page + (((unsigned long)(vaddr)) & zero_page_mask)))) +#define is_zero_pfn is_zero_pfn +static inline int is_zero_pfn(unsigned long pfn) +{ + extern unsigned long zero_pfn; + unsigned long offset_from_zero_pfn = pfn - zero_pfn; + return offset_from_zero_pfn <= (zero_page_mask >> PAGE_SHIFT); +} + +#define my_zero_pfn(addr) page_to_pfn(ZERO_PAGE(addr)) + extern void paging_init(void); /* -- cgit v1.2.3