mm: add link from struct lruvec to struct zone

This is the first stage of struct mem_cgroup_zone removal.  Further
patches replace struct mem_cgroup_zone with a pointer to struct lruvec.

If CONFIG_CGROUP_MEM_RES_CTLR=n lruvec_zone() is just container_of().

Signed-off-by: Konstantin Khlebnikov <khlebnikov@openvz.org>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

3 files changed, 16 insertions, 10 deletions

diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index a8abf919c70a..39b2c14f1509 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -4738,7 +4738,6 @@ static int alloc_mem_cgroup_per_zone_info(struct mem_cgroup *memcg, int node)
 {
         struct mem_cgroup_per_node *pn;
         struct mem_cgroup_per_zone *mz;
-        enum lru_list lru;
         int zone, tmp = node;
         /*
          * This routine is called against possible nodes.
@@ -4756,8 +4755,7 @@ static int alloc_mem_cgroup_per_zone_info(struct mem_cgroup *memcg, int node)
 
         for (zone = 0; zone < MAX_NR_ZONES; zone++) {
                 mz = &pn->zoneinfo[zone];
-                for_each_lru(lru)
-                        INIT_LIST_HEAD(&mz->lruvec.lists[lru]);
+                lruvec_init(&mz->lruvec, &NODE_DATA(node)->node_zones[zone]);
                 mz->usage_in_excess = 0;
                 mz->on_tree = false;
                 mz->memcg = memcg;
diff --git a/mm/mmzone.c b/mm/mmzone.c
index 7cf7b7ddc7c5..6830eab5bf09 100644
--- a/mm/mmzone.c
+++ b/mm/mmzone.c
@@ -86,3 +86,17 @@ int memmap_valid_within(unsigned long pfn,
         return 1;
 }
 #endif /* CONFIG_ARCH_HAS_HOLES_MEMORYMODEL */
+
+void lruvec_init(struct lruvec *lruvec, struct zone *zone)
+{
+        enum lru_list lru;
+
+        memset(lruvec, 0, sizeof(struct lruvec));
+
+        for_each_lru(lru)
+                INIT_LIST_HEAD(&lruvec->lists[lru]);
+
+#ifdef CONFIG_CGROUP_MEM_RES_CTLR
+        lruvec->zone = zone;
+#endif
+}
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 8cbfc38e68ac..6092f331b32e 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -4358,7 +4358,6 @@ static void __paginginit free_area_init_core(struct pglist_data *pgdat,
         for (j = 0; j < MAX_NR_ZONES; j++) {
                 struct zone *zone = pgdat->node_zones + j;
                 unsigned long size, realsize, memmap_pages;
-                enum lru_list lru;
 
                 size = zone_spanned_pages_in_node(nid, j, zones_size);
                 realsize = size - zone_absent_pages_in_node(nid, j,
@@ -4408,12 +4407,7 @@ static void __paginginit free_area_init_core(struct pglist_data *pgdat,
                 zone->zone_pgdat = pgdat;
 
                 zone_pcp_init(zone);
-                for_each_lru(lru)
-                        INIT_LIST_HEAD(&zone->lruvec.lists[lru]);
-                zone->lruvec.reclaim_stat.recent_rotated[0] = 0;
-                zone->lruvec.reclaim_stat.recent_rotated[1] = 0;
-                zone->lruvec.reclaim_stat.recent_scanned[0] = 0;
-                zone->lruvec.reclaim_stat.recent_scanned[1] = 0;
+                lruvec_init(&zone->lruvec, zone);
                 zap_zone_vm_stats(zone);
                 zone->flags = 0;
                 if (!size)