From 6d91add09f4bad5f4d4233b13faa392f0c4b16be Mon Sep 17 00:00:00 2001
From: Hugh Dickins <hugh@veritas.com>
Date: Tue, 6 Jan 2009 14:39:24 -0800
Subject: [PATCH] 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>
---
include/linux/page-flags.h | 1 +
mm/migrate.c | 4 ----
2 files changed, 1 insertion(+), 4 deletions(-)
diff --git a/include/linux/page-flags.h b/include/linux/page-flags.h
index b12f93a3c345..628ec0802492 100644
--- a/include/linux/page-flags.h
+++ b/include/linux/page-flags.h
@@ -228,6 +228,7 @@ PAGEFLAG_FALSE(HighMem)
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 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() */
--
2.34.1