diff options
| author | Hugh Dickins <hughd@google.com> | 2011-01-13 15:47:31 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2011-01-13 17:32:49 -0800 |
| commit | fd4a4663db293bfd5dc20fb4113977f62895e550 (patch) | |
| tree | a161c087d714042b5402b858b9a6ee75392ecab2 /mm | |
| parent | 1ce82b69e96c838d007f316b8347b911fdfa9842 (diff) | |
| download | lwn-fd4a4663db293bfd5dc20fb4113977f62895e550.tar.gz lwn-fd4a4663db293bfd5dc20fb4113977f62895e550.zip | |
mm: fix hugepage migration
2.6.37 added an unmap_and_move_huge_page() for memory failure recovery,
but its anon_vma handling was still based around the 2.6.35 conventions.
Update it to use page_lock_anon_vma, get_anon_vma, page_unlock_anon_vma,
drop_anon_vma in the same way as we're now changing unmap_and_move().
I don't particularly like to propose this for stable when I've not seen
its problems in practice nor tested the solution: but it's clearly out of
synch at present.
Signed-off-by: Hugh Dickins <hughd@google.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Rik van Riel <riel@redhat.com>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: "Jun'ichi Nomura" <j-nomura@ce.jp.nec.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: <stable@kernel.org> [2.6.37, 2.6.36]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm')
| -rw-r--r-- | mm/migrate.c | 23 |
1 files changed, 6 insertions, 17 deletions
diff --git a/mm/migrate.c b/mm/migrate.c index a20cf12edede..5b7d1fd29621 100644 --- a/mm/migrate.c +++ b/mm/migrate.c @@ -827,7 +827,6 @@ static int unmap_and_move_huge_page(new_page_t get_new_page, int rc = 0; int *result = NULL; struct page *new_hpage = get_new_page(hpage, private, &result); - int rcu_locked = 0; struct anon_vma *anon_vma = NULL; if (!new_hpage) @@ -842,12 +841,10 @@ static int unmap_and_move_huge_page(new_page_t get_new_page, } if (PageAnon(hpage)) { - rcu_read_lock(); - rcu_locked = 1; - - if (page_mapped(hpage)) { - anon_vma = page_anon_vma(hpage); - atomic_inc(&anon_vma->external_refcount); + anon_vma = page_lock_anon_vma(hpage); + if (anon_vma) { + get_anon_vma(anon_vma); + page_unlock_anon_vma(anon_vma); } } @@ -859,16 +856,8 @@ static int unmap_and_move_huge_page(new_page_t get_new_page, if (rc) remove_migration_ptes(hpage, hpage); - if (anon_vma && atomic_dec_and_lock(&anon_vma->external_refcount, - &anon_vma->lock)) { - int empty = list_empty(&anon_vma->head); - spin_unlock(&anon_vma->lock); - if (empty) - anon_vma_free(anon_vma); - } - - if (rcu_locked) - rcu_read_unlock(); + if (anon_vma) + drop_anon_vma(anon_vma); out: unlock_page(hpage); |