mm: make per-memcg LRU lists exclusive

Now that all code that operated on global per-zone LRU lists is
converted to operate on per-memory cgroup LRU lists instead, there is no
reason to keep the double-LRU scheme around any longer.

The pc->lru member is removed and page->lru is linked directly to the
per-memory cgroup LRU lists, which removes two pointers from a
descriptor that exists for every page frame in the system.

Signed-off-by: Johannes Weiner <jweiner@redhat.com>
Signed-off-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Ying Han <yinghan@google.com>
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Reviewed-by: Michal Hocko <mhocko@suse.cz>
Reviewed-by: Kirill A. Shutemov <kirill@shutemov.name>
Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Cc: Balbir Singh <bsingharora@gmail.com>
Cc: Greg Thelen <gthelen@google.com>
Cc: Michel Lespinasse <walken@google.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Minchan Kim <minchan.kim@gmail.com>
Cc: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/swap.c

@@ -232,12 +232,14 @@ static void pagevec_lru_move_fn(struct pagevec *pvec,
 static void pagevec_move_tail_fn(struct page *page, void *arg)
 {
 	int *pgmoved = arg;
-	struct zone *zone = page_zone(page);
 
 	if (PageLRU(page) && !PageActive(page) && !PageUnevictable(page)) {
 		enum lru_list lru = page_lru_base_type(page);
-		list_move_tail(&page->lru, &zone->lruvec.lists[lru]);
-		mem_cgroup_rotate_reclaimable_page(page);
+		struct lruvec *lruvec;
+
+		lruvec = mem_cgroup_lru_move_lists(page_zone(page),
+						   page, lru, lru);
+		list_move_tail(&page->lru, &lruvec->lists[lru]);
 		(*pgmoved)++;
 	}
 }
@@ -476,12 +478,13 @@ static void lru_deactivate_fn(struct page *page, void *arg)
 		 */
 		SetPageReclaim(page);
 	} else {
+		struct lruvec *lruvec;
 		/*
 		 * The page's writeback ends up during pagevec
 		 * We moves tha page into tail of inactive.
 		 */
-		list_move_tail(&page->lru, &zone->lruvec.lists[lru]);
-		mem_cgroup_rotate_reclaimable_page(page);
+		lruvec = mem_cgroup_lru_move_lists(zone, page, lru, lru);
+		list_move_tail(&page->lru, &lruvec->lists[lru]);
 		__count_vm_event(PGROTATED);
 	}
 
@@ -663,6 +666,8 @@ void lru_add_page_tail(struct zone* zone,
 	SetPageLRU(page_tail);
 
 	if (page_evictable(page_tail, NULL)) {
+		struct lruvec *lruvec;
+
 		if (PageActive(page)) {
 			SetPageActive(page_tail);
 			active = 1;
@@ -672,11 +677,13 @@ void lru_add_page_tail(struct zone* zone,
 			lru = LRU_INACTIVE_ANON;
 		}
 		update_page_reclaim_stat(zone, page_tail, file, active);
+		lruvec = mem_cgroup_lru_add_list(zone, page_tail, lru);
 		if (likely(PageLRU(page)))
-			__add_page_to_lru_list(zone, page_tail, lru,
-					       page->lru.prev);
+			list_add(&page_tail->lru, page->lru.prev);
 		else
-			add_page_to_lru_list(zone, page_tail, lru);
+			list_add(&page_tail->lru, &lruvec->lists[lru]);
+		__mod_zone_page_state(zone, NR_LRU_BASE + lru,
+				      hpage_nr_pages(page_tail));
 	} else {
 		SetPageUnevictable(page_tail);
 		add_page_to_lru_list(zone, page_tail, LRU_UNEVICTABLE);