page allocator: move free_page_mlock() to page_alloc.c

Currently, free_page_mlock() is only called from page_alloc.c.  Thus, we
can move it to page_alloc.c.

Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: Dave Hansen <dave@linux.vnet.ibm.com>
Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/mm/internal.h b/mm/internal.h
index 58ec1bc..4b1672a 100644
--- a/mm/internal.h
+++ b/mm/internal.h
@@ -150,18 +150,6 @@
 	}
 }
 
-/*
- * free_page_mlock() -- clean up attempts to free and mlocked() page.
- * Page should not be on lru, so no need to fix that up.
- * free_pages_check() will verify...
- */
-static inline void free_page_mlock(struct page *page)
-{
-	__ClearPageMlocked(page);
-	__dec_zone_page_state(page, NR_MLOCK);
-	__count_vm_event(UNEVICTABLE_MLOCKFREED);
-}
-
 #else /* CONFIG_HAVE_MLOCKED_PAGE_BIT */
 static inline int is_mlocked_vma(struct vm_area_struct *v, struct page *p)
 {
@@ -170,7 +158,6 @@
 static inline void clear_page_mlock(struct page *page) { }
 static inline void mlock_vma_page(struct page *page) { }
 static inline void mlock_migrate_page(struct page *new, struct page *old) { }
-static inline void free_page_mlock(struct page *page) { }
 
 #endif /* CONFIG_HAVE_MLOCKED_PAGE_BIT */
 
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 0c9f406..5dac5d8 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -493,6 +493,22 @@
 	zone->free_area[order].nr_free++;
 }
 
+#ifdef CONFIG_HAVE_MLOCKED_PAGE_BIT
+/*
+ * free_page_mlock() -- clean up attempts to free and mlocked() page.
+ * Page should not be on lru, so no need to fix that up.
+ * free_pages_check() will verify...
+ */
+static inline void free_page_mlock(struct page *page)
+{
+	__ClearPageMlocked(page);
+	__dec_zone_page_state(page, NR_MLOCK);
+	__count_vm_event(UNEVICTABLE_MLOCKFREED);
+}
+#else
+static void free_page_mlock(struct page *page) { }
+#endif
+
 static inline int free_pages_check(struct page *page)
 {
 	if (unlikely(page_mapcount(page) |