diff options
| author | Peter Zijlstra <a.p.zijlstra@chello.nl> | 2011-05-24 17:12:10 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2011-05-25 08:39:19 -0700 |
| commit | 746b18d421da7f27e948e8af1ad82b6d0309324d (patch) | |
| tree | d4e756977673b7b8166c00e34a21d85c5e26ea6e /mm/migrate.c | |
| parent | 6111e4ca6829a0e8b092b8e5eeb6b5366091f29c (diff) | |
| download | linux-746b18d421da7f27e948e8af1ad82b6d0309324d.tar.bz2 | |
mm: use refcounts for page_lock_anon_vma()
Convert page_lock_anon_vma() over to use refcounts. This is done to
prepare for the conversion of anon_vma from spinlock to mutex.
Sadly this inceases the cost of page_lock_anon_vma() from one to two
atomics, a follow up patch addresses this, lets keep that simple for now.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Acked-by: Hugh Dickins <hughd@google.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: David Miller <davem@davemloft.net>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Nick Piggin <npiggin@kernel.dk>
Cc: Namhyung Kim <namhyung@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/migrate.c')
| -rw-r--r-- | mm/migrate.c | 17 |
1 files changed, 4 insertions, 13 deletions
diff --git a/mm/migrate.c b/mm/migrate.c index 34132f8e9109..e4a5c912983d 100644 --- a/mm/migrate.c +++ b/mm/migrate.c @@ -721,15 +721,11 @@ static int unmap_and_move(new_page_t get_new_page, unsigned long private, * Only page_lock_anon_vma() understands the subtleties of * getting a hold on an anon_vma from outside one of its mms. */ - anon_vma = page_lock_anon_vma(page); + anon_vma = page_get_anon_vma(page); if (anon_vma) { /* - * Take a reference count on the anon_vma if the - * page is mapped so that it is guaranteed to - * exist when the page is remapped later + * Anon page */ - get_anon_vma(anon_vma); - page_unlock_anon_vma(anon_vma); } else if (PageSwapCache(page)) { /* * We cannot be sure that the anon_vma of an unmapped @@ -857,13 +853,8 @@ static int unmap_and_move_huge_page(new_page_t get_new_page, lock_page(hpage); } - if (PageAnon(hpage)) { - anon_vma = page_lock_anon_vma(hpage); - if (anon_vma) { - get_anon_vma(anon_vma); - page_unlock_anon_vma(anon_vma); - } - } + if (PageAnon(hpage)) + anon_vma = page_get_anon_vma(hpage); try_to_unmap(hpage, TTU_MIGRATION|TTU_IGNORE_MLOCK|TTU_IGNORE_ACCESS); |