4 files changed, 38 insertions, 18 deletions

diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h
index 50aaca81f63d..a23923ba8263 100644
--- a/include/linux/mmzone.h
+++ b/include/linux/mmzone.h
@@ -752,7 +752,7 @@ extern int init_currently_empty_zone(struct zone *zone, unsigned long start_pfn,
                                      unsigned long size,
                                      enum memmap_context context);
 
-extern void lruvec_init(struct lruvec *lruvec, struct zone *zone);
+extern void lruvec_init(struct lruvec *lruvec);
 
 static inline struct zone *lruvec_zone(struct lruvec *lruvec)
 {
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 93a7e36ded89..dd39ba000b31 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -1055,12 +1055,24 @@ struct lruvec *mem_cgroup_zone_lruvec(struct zone *zone,
                                       struct mem_cgroup *memcg)
 {
         struct mem_cgroup_per_zone *mz;
+        struct lruvec *lruvec;
 
-        if (mem_cgroup_disabled())
-                return &zone->lruvec;
+        if (mem_cgroup_disabled()) {
+                lruvec = &zone->lruvec;
+                goto out;
+        }
 
         mz = mem_cgroup_zoneinfo(memcg, zone_to_nid(zone), zone_idx(zone));
-        return &mz->lruvec;
+        lruvec = &mz->lruvec;
+out:
+        /*
+         * Since a node can be onlined after the mem_cgroup was created,
+         * we have to be prepared to initialize lruvec->zone here;
+         * and if offlined then reonlined, we need to reinitialize it.
+         */
+        if (unlikely(lruvec->zone != zone))
+                lruvec->zone = zone;
+        return lruvec;
 }
 
 /*
@@ -1087,9 +1099,12 @@ struct lruvec *mem_cgroup_page_lruvec(struct page *page, struct zone *zone)
         struct mem_cgroup_per_zone *mz;
         struct mem_cgroup *memcg;
         struct page_cgroup *pc;
+        struct lruvec *lruvec;
 
-        if (mem_cgroup_disabled())
-                return &zone->lruvec;
+        if (mem_cgroup_disabled()) {
+                lruvec = &zone->lruvec;
+                goto out;
+        }
 
         pc = lookup_page_cgroup(page);
         memcg = pc->mem_cgroup;
@@ -1107,7 +1122,16 @@ struct lruvec *mem_cgroup_page_lruvec(struct page *page, struct zone *zone)
                 pc->mem_cgroup = memcg = root_mem_cgroup;
 
         mz = page_cgroup_zoneinfo(memcg, page);
-        return &mz->lruvec;
+        lruvec = &mz->lruvec;
+out:
+        /*
+         * Since a node can be onlined after the mem_cgroup was created,
+         * we have to be prepared to initialize lruvec->zone here;
+         * and if offlined then reonlined, we need to reinitialize it.
+         */
+        if (unlikely(lruvec->zone != zone))
+                lruvec->zone = zone;
+        return lruvec;
 }
 
 /**
@@ -3697,17 +3721,17 @@ unsigned long mem_cgroup_soft_limit_reclaim(struct zone *zone, int order,
 static bool mem_cgroup_force_empty_list(struct mem_cgroup *memcg,
                                 int node, int zid, enum lru_list lru)
 {
-        struct mem_cgroup_per_zone *mz;
+        struct lruvec *lruvec;
         unsigned long flags, loop;
         struct list_head *list;
         struct page *busy;
         struct zone *zone;
 
         zone = &NODE_DATA(node)->node_zones[zid];
-        mz = mem_cgroup_zoneinfo(memcg, node, zid);
-        list = &mz->lruvec.lists[lru];
+        lruvec = mem_cgroup_zone_lruvec(zone, memcg);
+        list = &lruvec->lists[lru];
 
-        loop = mz->lru_size[lru];
+        loop = mem_cgroup_get_lru_size(lruvec, lru);
         /* give some margin against EBUSY etc...*/
         loop += 256;
         busy = NULL;
@@ -4745,7 +4769,7 @@ 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];
-                lruvec_init(&mz->lruvec, &NODE_DATA(node)->node_zones[zone]);
+                lruvec_init(&mz->lruvec);
                 mz->usage_in_excess = 0;
                 mz->on_tree = false;
                 mz->memcg = memcg;
diff --git a/mm/mmzone.c b/mm/mmzone.c
index 3cef80f6ac79..4596d81b89b1 100644
--- a/mm/mmzone.c
+++ b/mm/mmzone.c
@@ -87,7 +87,7 @@ int memmap_valid_within(unsigned long pfn,
 }
 #endif /* CONFIG_ARCH_HAS_HOLES_MEMORYMODEL */
 
-void lruvec_init(struct lruvec *lruvec, struct zone *zone)
+void lruvec_init(struct lruvec *lruvec)
 {
         enum lru_list lru;
 
@@ -95,8 +95,4 @@ void lruvec_init(struct lruvec *lruvec, struct zone *zone)
 
         for_each_lru(lru)
                 INIT_LIST_HEAD(&lruvec->lists[lru]);
-
-#ifdef CONFIG_MEMCG
-        lruvec->zone = zone;
-#endif
 }
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 5b74de6702e0..c91598b1b4c0 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -4505,7 +4505,7 @@ static void __paginginit free_area_init_core(struct pglist_data *pgdat,
                 zone->zone_pgdat = pgdat;
 
                 zone_pcp_init(zone);
-                lruvec_init(&zone->lruvec, zone);
+                lruvec_init(&zone->lruvec);
                 if (!size)
                         continue;