mm, vmscan: make shrink_node decisions more node-centric

Earlier patches focused on having direct reclaim and kswapd use data
that is node-centric for reclaiming but shrink_node() itself still uses
too much zone information.  This patch removes unnecessary zone-based
information with the most important decision being whether to continue
reclaim or not.  Some memcg APIs are adjusted as a result even though
memcg itself still uses some zone information.

[mgorman@techsingularity.net: optimization]
  Link: http://lkml.kernel.org/r/1468588165-12461-2-git-send-email-mgorman@techsingularity.net
Link: http://lkml.kernel.org/r/1467970510-21195-14-git-send-email-mgorman@techsingularity.net
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Hillf Danton <hillf.zj@alibaba-inc.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Rik van Riel <riel@surriel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 50c86ad..c9ebec9 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -1432,8 +1432,8 @@
 			}
 			continue;
 		}
-		total += mem_cgroup_shrink_node_zone(victim, gfp_mask, false,
-						     zone, &nr_scanned);
+		total += mem_cgroup_shrink_node(victim, gfp_mask, false,
+					zone, &nr_scanned);
 		*total_scanned += nr_scanned;
 		if (!soft_limit_excess(root_memcg))
 			break;