mm/memcg: apply add/del_page to lruvec

Take lruvec further: pass it instead of zone to add_page_to_lru_list() and
del_page_from_lru_list(); and pagevec_lru_move_fn() pass lruvec down to
its target functions.

This cleanup eliminates a swathe of cruft in memcontrol.c, including
mem_cgroup_lru_add_list(), mem_cgroup_lru_del_list() and
mem_cgroup_lru_move_lists() - which never actually touched the lists.

In their place, mem_cgroup_page_lruvec() to decide the lruvec, previously
a side-effect of add, and mem_cgroup_update_lru_size() to maintain the
lru_size stats.

Whilst these are simplifications in their own right, the goal is to bring
the evaluation of lruvec next to the spin_locking of the lrus, in
preparation for a future patch.

Signed-off-by: Hugh Dickins <hughd@google.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-by: Michal Hocko <mhocko@suse.cz>
Acked-by: Konstantin Khlebnikov <khlebnikov@openvz.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
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 16d45d9..1397ccf 100644
--- a/include/linux/mm_inline.h
+++ b/include/linux/mm_inline.h
@@ -21,22 +21,22 @@
 	return !PageSwapBacked(page);
 }
 
-static __always_inline void
-add_page_to_lru_list(struct zone *zone, struct page *page, enum lru_list lru)
+static __always_inline void add_page_to_lru_list(struct page *page,
+				struct lruvec *lruvec, enum lru_list lru)
 {
-	struct lruvec *lruvec;
-
-	lruvec = mem_cgroup_lru_add_list(zone, page, lru);
+	int nr_pages = hpage_nr_pages(page);
+	mem_cgroup_update_lru_size(lruvec, lru, nr_pages);
 	list_add(&page->lru, &lruvec->lists[lru]);
-	__mod_zone_page_state(zone, NR_LRU_BASE + lru, hpage_nr_pages(page));
+	__mod_zone_page_state(lruvec_zone(lruvec), NR_LRU_BASE + lru, nr_pages);
 }
 
-static __always_inline void
-del_page_from_lru_list(struct zone *zone, struct page *page, enum lru_list lru)
+static __always_inline void del_page_from_lru_list(struct page *page,
+				struct lruvec *lruvec, enum lru_list lru)
 {
-	mem_cgroup_lru_del_list(page, lru);
+	int nr_pages = hpage_nr_pages(page);
+	mem_cgroup_update_lru_size(lruvec, lru, -nr_pages);
 	list_del(&page->lru);
-	__mod_zone_page_state(zone, NR_LRU_BASE + lru, -hpage_nr_pages(page));
+	__mod_zone_page_state(lruvec_zone(lruvec), NR_LRU_BASE + lru, -nr_pages);
 }
 
 /**