diff --git a/[refs] b/[refs]
index 0018f5ce5be3..1aa510c615b4 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: edcf4748cd56adcdf0856cc99ef108a4ea3ac7fe
+refs/heads/master: ceddc3a52d783fabbf1ba623601419b9d6337194
diff --git a/trunk/mm/vmscan.c b/trunk/mm/vmscan.c
index f5b5f029288c..5be8107e7758 100644
--- a/trunk/mm/vmscan.c
+++ b/trunk/mm/vmscan.c
@@ -286,6 +286,11 @@ static inline int page_mapping_inuse(struct page *page)
 
 static inline int is_page_cache_freeable(struct page *page)
 {
+	/*
+	 * A freeable page cache page is referenced only by the caller
+	 * that isolated the page, the page cache radix tree and
+	 * optional buffer heads at page->private.
+	 */
 	return page_count(page) - page_has_private(page) == 2;
 }