diff options
| author | Hugh Dickins <hugh.dickins@tiscali.co.uk> | 2009-09-21 17:03:34 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2009-09-22 07:17:41 -0700 |
| commit | 62eede62dafb4a6633eae7ffbeb34c60dba5e7b1 (patch) | |
| tree | e55a0ca4ad0c55ad162443146268cfb4c473750f /arch | |
| parent | 3ae77f43b1118a76ea37952d444319c15e002c03 (diff) | |
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 <hugh.dickins@tiscali.co.uk>
Cc: Rik van Riel <riel@redhat.com>
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Nick Piggin <npiggin@suse.de>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Minchan Kim <minchan.kim@gmail.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/mips/include/asm/pgtable.h | 10 |
1 files changed, 10 insertions, 0 deletions
diff --git a/arch/mips/include/asm/pgtable.h b/arch/mips/include/asm/pgtable.h index 1a9f9b25755..d6eb6134abe 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); /* |