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>
diff --git a/include/linux/page-flags.h b/include/linux/page-flags.h
index b12f93a..628ec08 100644
--- a/include/linux/page-flags.h
+++ b/include/linux/page-flags.h
@@ -228,6 +228,7 @@
PAGEFLAG(SwapCache, swapcache)
#else
PAGEFLAG_FALSE(SwapCache)
+ SETPAGEFLAG_NOOP(SwapCache) CLEARPAGEFLAG_NOOP(SwapCache)
#endif
#ifdef CONFIG_UNEVICTABLE_LRU
diff --git a/mm/migrate.c b/mm/migrate.c
index 6051030..5537398 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -300,12 +300,10 @@
* 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 @@
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() */