diff options
| author | Rik van Riel <riel@redhat.com> | 2010-03-05 13:42:09 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2010-03-06 11:26:26 -0800 |
| commit | c44b674323f4a2480dbeb65d4b487fa5f06f49e0 (patch) | |
| tree | b753050e6752eb2fc961ad3ea5dfdf88ef88364d /include/linux/rmap.h | |
| parent | 033a64b56aed798991de18d226085dfb1ccd858d (diff) | |
rmap: move exclusively owned pages to own anon_vma in do_wp_page()
When the parent process breaks the COW on a page, both the original which
is mapped at child and the new page which is mapped parent end up in that
same anon_vma. Generally this won't be a problem, but for some workloads
it could preserve the O(N) rmap scanning complexity.
A simple fix is to ensure that, when a page which is mapped child gets
reused in do_wp_page, because we already are the exclusive owner, the page
gets moved to our own exclusive child's anon_vma.
Signed-off-by: Rik van Riel <riel@redhat.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Larry Woodman <lwoodman@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
Reviewed-by: Minchan Kim <minchan.kim@gmail.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Hugh Dickins <hugh.dickins@tiscali.co.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'include/linux/rmap.h')
| -rw-r--r-- | include/linux/rmap.h | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/include/linux/rmap.h b/include/linux/rmap.h index 62da2001d55..72be23b1480 100644 --- a/include/linux/rmap.h +++ b/include/linux/rmap.h @@ -125,6 +125,7 @@ static inline void anon_vma_merge(struct vm_area_struct *vma, /* * rmap interfaces called when adding or removing pte of page */ +void page_move_anon_rmap(struct page *, struct vm_area_struct *, unsigned long); void page_add_anon_rmap(struct page *, struct vm_area_struct *, unsigned long); void page_add_new_anon_rmap(struct page *, struct vm_area_struct *, unsigned long); void page_add_file_rmap(struct page *); |