diff options
| author | Kirill A. Shutemov <kirill.shutemov@linux.intel.com> | 2012-12-12 13:50:54 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2012-12-12 17:38:31 -0800 |
| commit | 93b4796dede916de74b21fbd637588da6a99a7ec (patch) | |
| tree | 3833de6051bb1b8d361a614743aafa56b43902e1 /include/linux | |
| parent | fc9fe822f7112db23e51e2be3b886f5d8f0afdb6 (diff) | |
thp: do_huge_pmd_wp_page(): handle huge zero page
On write access to huge zero page we alloc a new huge page and clear it.
If ENOMEM, graceful fallback: we create a new pmd table and set pte around
fault address to newly allocated normal (4k) page. All other ptes in the
pmd set to normal zero page.
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: "H. Peter Anvin" <hpa@linux.intel.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Acked-by: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'include/linux')
| -rw-r--r-- | include/linux/mm.h | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/include/linux/mm.h b/include/linux/mm.h index 4af4f0b1be4..4b80bad4a36 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -516,6 +516,14 @@ static inline pte_t maybe_mkwrite(pte_t pte, struct vm_area_struct *vma) } #endif +#ifndef my_zero_pfn +static inline unsigned long my_zero_pfn(unsigned long addr) +{ + extern unsigned long zero_pfn; + return zero_pfn; +} +#endif + /* * Multiple processes may "see" the same page. E.g. for untouched * mappings of /dev/null, all processes see the same page full of |