mm: remove unevictable_migrate_page function

unevictable_migrate_page() in mm/internal.h is a relic of the since
removed UNEVICTABLE_LRU Kconfig option.  This patch removes the function
and open codes the test in migrate_page_copy().

Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com>
Reviewed-by: Christoph Lameter <cl@linux-foundation.org>
Acked-by: Hugh Dickins <hugh.dickins@tiscali.co.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/internal.h

@@ -63,18 +63,6 @@ static inline unsigned long page_order(struct page *page)
 	return page_private(page);
 }
 
-/*
- * unevictable_migrate_page() called only from migrate_page_copy() to
- * migrate unevictable flag to new page.
- * Note that the old page has been isolated from the LRU lists at this
- * point so we don't need to worry about LRU statistics.
- */
-static inline void unevictable_migrate_page(struct page *new, struct page *old)
-{
-	if (TestClearPageUnevictable(old))
-		SetPageUnevictable(new);
-}
-
 #ifdef CONFIG_MMU
 extern long mlock_vma_pages_range(struct vm_area_struct *vma,
 			unsigned long start, unsigned long end);

mm/migrate.c

@@ -288,8 +288,8 @@ static void migrate_page_copy(struct page *newpage, struct page *page)
 	if (TestClearPageActive(page)) {
 		VM_BUG_ON(PageUnevictable(page));
 		SetPageActive(newpage);
-	} else
-		unevictable_migrate_page(newpage, page);
+	} else if (TestClearPageUnevictable(page))
+		SetPageUnevictable(newpage);
 	if (PageChecked(page))
 		SetPageChecked(newpage);
 	if (PageMappedToDisk(page))