mm: add Set,ClearPageSwapCache stubs

If we add NOOP stubs for SetPageSwapCache() and ClearPageSwapCache(), then
we can remove the #ifdef CONFIG_SWAPs from mm/migrate.c.

Signed-off-by: Hugh Dickins <hugh@veritas.com>
Acked-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Cc: Mel Gorman <mel@csn.ul.ie>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 0 insertions, 4 deletions

diff --git a/mm/migrate.c b/mm/migrate.c
index 60510306c44a..55373983c9c6 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -300,12 +300,10 @@ static int migrate_page_move_mapping(struct address_space *mapping,
          * Now we know that no one else is looking at the page.
          */
         get_page(newpage);      /* add cache reference */
-#ifdef CONFIG_SWAP
         if (PageSwapCache(page)) {
                 SetPageSwapCache(newpage);
                 set_page_private(newpage, page_private(page));
         }
-#endif
 
         radix_tree_replace_slot(pslot, newpage);
 
@@ -373,9 +371,7 @@ static void migrate_page_copy(struct page *newpage, struct page *page)
 
         mlock_migrate_page(newpage, page);
 
-#ifdef CONFIG_SWAP
         ClearPageSwapCache(page);
-#endif
         ClearPagePrivate(page);
         set_page_private(page, 0);
         /* page->mapping contains a flag for PageAnon() */