memcg: mem_cgroup_shrink_node_zone() doesn't need sc.nodemask

Currently mem_cgroup_shrink_node_zone() call shrink_zone() directly.  thus
it doesn't need to initialize sc.nodemask because shrink_zone() doesn't
use it at all.

Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-by: Mel Gorman <mel@csn.ul.ie>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: Nishimura Daisuke <d-nishimura@mtf.biglobe.ne.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

include/linux/swap.h

@@ -244,8 +244,7 @@ extern unsigned long try_to_free_mem_cgroup_pages(struct mem_cgroup *mem,
 extern unsigned long mem_cgroup_shrink_node_zone(struct mem_cgroup *mem,
 						gfp_t gfp_mask, bool noswap,
 						unsigned int swappiness,
-						struct zone *zone,
-						int nid);
+						struct zone *zone);
 extern int __isolate_lru_page(struct page *page, int mode, int file);
 extern unsigned long shrink_all_memory(unsigned long nr_pages);
 extern int vm_swappiness;

mm/memcontrol.c

@@ -1300,8 +1300,7 @@ static int mem_cgroup_hierarchical_reclaim(struct mem_cgroup *root_mem,
 		/* we use swappiness of local cgroup */
 		if (check_soft)
 			ret = mem_cgroup_shrink_node_zone(victim, gfp_mask,
-				noswap, get_swappiness(victim), zone,
-				zone->zone_pgdat->node_id);
+				noswap, get_swappiness(victim), zone);
 		else
 			ret = try_to_free_mem_cgroup_pages(victim, gfp_mask,
 						noswap, get_swappiness(victim));

mm/vmscan.c

@@ -1969,7 +1969,7 @@ unsigned long try_to_free_pages(struct zonelist *zonelist, int order,
 unsigned long mem_cgroup_shrink_node_zone(struct mem_cgroup *mem,
 						gfp_t gfp_mask, bool noswap,
 						unsigned int swappiness,
-						struct zone *zone, int nid)
+						struct zone *zone)
 {
 	struct scan_control sc = {
 		.nr_to_reclaim = SWAP_CLUSTER_MAX,
@@ -1980,11 +1980,8 @@ unsigned long mem_cgroup_shrink_node_zone(struct mem_cgroup *mem,
 		.order = 0,
 		.mem_cgroup = mem,
 	};
-	nodemask_t nm  = nodemask_of_node(nid);
-
 	sc.gfp_mask = (gfp_mask & GFP_RECLAIM_MASK) |
 			(GFP_HIGHUSER_MOVABLE & ~GFP_RECLAIM_MASK);
-	sc.nodemask = &nm;
 
 	trace_mm_vmscan_memcg_softlimit_reclaim_begin(0,
 						      sc.may_writepage,