In test, some pages in swap-cache can't be migrated, as they aren't rmap.
unmap_and_move() ignores swap-cache page which is just read in and hasn't
rmap (see the comments in the code), but swap_aops provides .migratepage.
Better to migrate such pages instead of ignore them.
Signed-off-by: Shaohua Li <[email protected]>
---
mm/migrate.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
Index: linux/mm/migrate.c
===================================================================
--- linux.orig/mm/migrate.c 2009-06-26 09:41:05.000000000 +0800
+++ linux/mm/migrate.c 2009-06-26 10:00:49.000000000 +0800
@@ -147,7 +147,7 @@ out:
static void remove_file_migration_ptes(struct page *old, struct page *new)
{
struct vm_area_struct *vma;
- struct address_space *mapping = page_mapping(new);
+ struct address_space *mapping = new->mapping;
struct prio_tree_iter iter;
pgoff_t pgoff = new->index << (PAGE_CACHE_SHIFT - PAGE_SHIFT);
@@ -664,13 +664,15 @@ static int unmap_and_move(new_page_t get
* needs to be effective.
*/
try_to_free_buffers(page);
+ goto rcu_unlock;
}
- goto rcu_unlock;
+ goto skip_unmap;
}
/* Establish migration ptes or remove ptes */
try_to_unmap(page, 1);
+skip_unmap:
if (!page_mapped(page))
rc = move_to_new_page(newpage, page);