mm: remove del_page_from_lru, add page_off_lru

del_page_from_lru() repeats del_page_from_lru_list(), also working out
which LRU the page was on, clearing the relevant bits.  Decouple those
functions: remove del_page_from_lru() and add page_off_lru().

Signed-off-by: Hugh Dickins <hughd@google.com>
Reviewed-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/include/linux/mm_inline.h b/include/linux/mm_inline.h
index 8f84d2e..227fd3e 100644
--- a/include/linux/mm_inline.h
+++ b/include/linux/mm_inline.h
@@ -54,8 +54,14 @@
 	return LRU_INACTIVE_ANON;
 }
 
-static inline void
-del_page_from_lru(struct zone *zone, struct page *page)
+/**
+ * page_off_lru - which LRU list was page on? clearing its lru flags.
+ * @page: the page to test
+ *
+ * Returns the LRU list a page was on, as an index into the array of LRU
+ * lists; and clears its Unevictable or Active flags, ready for freeing.
+ */
+static inline enum lru_list page_off_lru(struct page *page)
 {
 	enum lru_list lru;
 
@@ -69,9 +75,7 @@
 			lru += LRU_ACTIVE;
 		}
 	}
-	mem_cgroup_lru_del_list(page, lru);
-	list_del(&page->lru);
-	__mod_zone_page_state(zone, NR_LRU_BASE + lru, -hpage_nr_pages(page));
+	return lru;
 }
 
 /**
@@ -92,7 +96,6 @@
 		if (PageActive(page))
 			lru += LRU_ACTIVE;
 	}
-
 	return lru;
 }