1 files changed, 507 insertions, 499 deletions

diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 2d5755544afe..7af1d5ee1598 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -201,8 +201,8 @@ struct mem_cgroup_eventfd_list {
         struct eventfd_ctx *eventfd;
 };
 
-static void mem_cgroup_threshold(struct mem_cgroup *mem);
-static void mem_cgroup_oom_notify(struct mem_cgroup *mem);
+static void mem_cgroup_threshold(struct mem_cgroup *memcg);
+static void mem_cgroup_oom_notify(struct mem_cgroup *memcg);
 
 /*
  * The memory controller data structure. The memory controller controls both
@@ -362,29 +362,29 @@ enum charge_type {
 #define MEM_CGROUP_RECLAIM_SOFT_BIT     0x2
 #define MEM_CGROUP_RECLAIM_SOFT         (1 << MEM_CGROUP_RECLAIM_SOFT_BIT)
 
-static void mem_cgroup_get(struct mem_cgroup *mem);
-static void mem_cgroup_put(struct mem_cgroup *mem);
-static struct mem_cgroup *parent_mem_cgroup(struct mem_cgroup *mem);
-static void drain_all_stock_async(struct mem_cgroup *mem);
+static void mem_cgroup_get(struct mem_cgroup *memcg);
+static void mem_cgroup_put(struct mem_cgroup *memcg);
+static struct mem_cgroup *parent_mem_cgroup(struct mem_cgroup *memcg);
+static void drain_all_stock_async(struct mem_cgroup *memcg);
 
 static struct mem_cgroup_per_zone *
-mem_cgroup_zoneinfo(struct mem_cgroup *mem, int nid, int zid)
+mem_cgroup_zoneinfo(struct mem_cgroup *memcg, int nid, int zid)
 {
-        return &mem->info.nodeinfo[nid]->zoneinfo[zid];
+        return &memcg->info.nodeinfo[nid]->zoneinfo[zid];
 }
 
-struct cgroup_subsys_state *mem_cgroup_css(struct mem_cgroup *mem)
+struct cgroup_subsys_state *mem_cgroup_css(struct mem_cgroup *memcg)
 {
-        return &mem->css;
+        return &memcg->css;
 }
 
 static struct mem_cgroup_per_zone *
-page_cgroup_zoneinfo(struct mem_cgroup *mem, struct page *page)
+page_cgroup_zoneinfo(struct mem_cgroup *memcg, struct page *page)
 {
         int nid = page_to_nid(page);
         int zid = page_zonenum(page);
 
-        return mem_cgroup_zoneinfo(mem, nid, zid);
+        return mem_cgroup_zoneinfo(memcg, nid, zid);
 }
 
 static struct mem_cgroup_tree_per_zone *
@@ -403,7 +403,7 @@ soft_limit_tree_from_page(struct page *page)
 }
 
 static void
-__mem_cgroup_insert_exceeded(struct mem_cgroup *mem,
+__mem_cgroup_insert_exceeded(struct mem_cgroup *memcg,
                                 struct mem_cgroup_per_zone *mz,
                                 struct mem_cgroup_tree_per_zone *mctz,
                                 unsigned long long new_usage_in_excess)
@@ -437,7 +437,7 @@ __mem_cgroup_insert_exceeded(struct mem_cgroup *mem,
 }
 
 static void
-__mem_cgroup_remove_exceeded(struct mem_cgroup *mem,
+__mem_cgroup_remove_exceeded(struct mem_cgroup *memcg,
                                 struct mem_cgroup_per_zone *mz,
                                 struct mem_cgroup_tree_per_zone *mctz)
 {
@@ -448,17 +448,17 @@ __mem_cgroup_remove_exceeded(struct mem_cgroup *mem,
 }
 
 static void
-mem_cgroup_remove_exceeded(struct mem_cgroup *mem,
+mem_cgroup_remove_exceeded(struct mem_cgroup *memcg,
                                 struct mem_cgroup_per_zone *mz,
                                 struct mem_cgroup_tree_per_zone *mctz)
 {
         spin_lock(&mctz->lock);
-        __mem_cgroup_remove_exceeded(mem, mz, mctz);
+        __mem_cgroup_remove_exceeded(memcg, mz, mctz);
         spin_unlock(&mctz->lock);
 }
 
 
-static void mem_cgroup_update_tree(struct mem_cgroup *mem, struct page *page)
+static void mem_cgroup_update_tree(struct mem_cgroup *memcg, struct page *page)
 {
         unsigned long long excess;
         struct mem_cgroup_per_zone *mz;
@@ -471,9 +471,9 @@ static void mem_cgroup_update_tree(struct mem_cgroup *mem, struct page *page)
          * Necessary to update all ancestors when hierarchy is used.
          * because their event counter is not touched.
          */
-        for (; mem; mem = parent_mem_cgroup(mem)) {
-                mz = mem_cgroup_zoneinfo(mem, nid, zid);
-                excess = res_counter_soft_limit_excess(&mem->res);
+        for (; memcg; memcg = parent_mem_cgroup(memcg)) {
+                mz = mem_cgroup_zoneinfo(memcg, nid, zid);
+                excess = res_counter_soft_limit_excess(&memcg->res);
                 /*
                  * We have to update the tree if mz is on RB-tree or
                  * mem is over its softlimit.
@@ -482,18 +482,18 @@ static void mem_cgroup_update_tree(struct mem_cgroup *mem, struct page *page)
                         spin_lock(&mctz->lock);
                         /* if on-tree, remove it */
                         if (mz->on_tree)
-                                __mem_cgroup_remove_exceeded(mem, mz, mctz);
+                                __mem_cgroup_remove_exceeded(memcg, mz, mctz);
                         /*
                          * Insert again. mz->usage_in_excess will be updated.
                          * If excess is 0, no tree ops.
                          */
-                        __mem_cgroup_insert_exceeded(mem, mz, mctz, excess);
+                        __mem_cgroup_insert_exceeded(memcg, mz, mctz, excess);
                         spin_unlock(&mctz->lock);
                 }
         }
 }
 
-static void mem_cgroup_remove_from_trees(struct mem_cgroup *mem)
+static void mem_cgroup_remove_from_trees(struct mem_cgroup *memcg)
 {
         int node, zone;
         struct mem_cgroup_per_zone *mz;
@@ -501,9 +501,9 @@ static void mem_cgroup_remove_from_trees(struct mem_cgroup *mem)
 
         for_each_node_state(node, N_POSSIBLE) {
                 for (zone = 0; zone < MAX_NR_ZONES; zone++) {
-                        mz = mem_cgroup_zoneinfo(mem, node, zone);
+                        mz = mem_cgroup_zoneinfo(memcg, node, zone);
                         mctz = soft_limit_tree_node_zone(node, zone);
-                        mem_cgroup_remove_exceeded(mem, mz, mctz);
+                        mem_cgroup_remove_exceeded(memcg, mz, mctz);
                 }
         }
 }
@@ -564,7 +564,7 @@ mem_cgroup_largest_soft_limit_node(struct mem_cgroup_tree_per_zone *mctz)
  * common workload, threashold and synchonization as vmstat[] should be
  * implemented.
  */
-static long mem_cgroup_read_stat(struct mem_cgroup *mem,
+static long mem_cgroup_read_stat(struct mem_cgroup *memcg,
                                  enum mem_cgroup_stat_index idx)
 {
         long val = 0;
@@ -572,81 +572,83 @@ static long mem_cgroup_read_stat(struct mem_cgroup *mem,
 
         get_online_cpus();
         for_each_online_cpu(cpu)
-                val += per_cpu(mem->stat->count[idx], cpu);
+                val += per_cpu(memcg->stat->count[idx], cpu);
 #ifdef CONFIG_HOTPLUG_CPU
-        spin_lock(&mem->pcp_counter_lock);
-        val += mem->nocpu_base.count[idx];
-        spin_unlock(&mem->pcp_counter_lock);
+        spin_lock(&memcg->pcp_counter_lock);
+        val += memcg->nocpu_base.count[idx];
+        spin_unlock(&memcg->pcp_counter_lock);
 #endif
         put_online_cpus();
         return val;
 }
 
-static void mem_cgroup_swap_statistics(struct mem_cgroup *mem,
+static void mem_cgroup_swap_statistics(struct mem_cgroup *memcg,
                                          bool charge)
 {
         int val = (charge) ? 1 : -1;
-        this_cpu_add(mem->stat->count[MEM_CGROUP_STAT_SWAPOUT], val);
+        this_cpu_add(memcg->stat->count[MEM_CGROUP_STAT_SWAPOUT], val);
 }
 
-void mem_cgroup_pgfault(struct mem_cgroup *mem, int val)
+void mem_cgroup_pgfault(struct mem_cgroup *memcg, int val)
 {
-        this_cpu_add(mem->stat->events[MEM_CGROUP_EVENTS_PGFAULT], val);
+        this_cpu_add(memcg->stat->events[MEM_CGROUP_EVENTS_PGFAULT], val);
 }
 
-void mem_cgroup_pgmajfault(struct mem_cgroup *mem, int val)
+void mem_cgroup_pgmajfault(struct mem_cgroup *memcg, int val)
 {
-        this_cpu_add(mem->stat->events[MEM_CGROUP_EVENTS_PGMAJFAULT], val);
+        this_cpu_add(memcg->stat->events[MEM_CGROUP_EVENTS_PGMAJFAULT], val);
 }
 
-static unsigned long mem_cgroup_read_events(struct mem_cgroup *mem,
+static unsigned long mem_cgroup_read_events(struct mem_cgroup *memcg,
                                             enum mem_cgroup_events_index idx)
 {
         unsigned long val = 0;
         int cpu;
 
         for_each_online_cpu(cpu)
-                val += per_cpu(mem->stat->events[idx], cpu);
+                val += per_cpu(memcg->stat->events[idx], cpu);
 #ifdef CONFIG_HOTPLUG_CPU
-        spin_lock(&mem->pcp_counter_lock);
-        val += mem->nocpu_base.events[idx];
-        spin_unlock(&mem->pcp_counter_lock);
+        spin_lock(&memcg->pcp_counter_lock);
+        val += memcg->nocpu_base.events[idx];
+        spin_unlock(&memcg->pcp_counter_lock);
 #endif
         return val;
 }
 
-static void mem_cgroup_charge_statistics(struct mem_cgroup *mem,
+static void mem_cgroup_charge_statistics(struct mem_cgroup *memcg,
                                          bool file, int nr_pages)
 {
         preempt_disable();
 
         if (file)
-                __this_cpu_add(mem->stat->count[MEM_CGROUP_STAT_CACHE], nr_pages);
+                __this_cpu_add(memcg->stat->count[MEM_CGROUP_STAT_CACHE],
+                                nr_pages);
         else
-                __this_cpu_add(mem->stat->count[MEM_CGROUP_STAT_RSS], nr_pages);
+                __this_cpu_add(memcg->stat->count[MEM_CGROUP_STAT_RSS],
+                                nr_pages);
 
         /* pagein of a big page is an event. So, ignore page size */
         if (nr_pages > 0)
-                __this_cpu_inc(mem->stat->events[MEM_CGROUP_EVENTS_PGPGIN]);
+                __this_cpu_inc(memcg->stat->events[MEM_CGROUP_EVENTS_PGPGIN]);
         else {
-                __this_cpu_inc(mem->stat->events[MEM_CGROUP_EVENTS_PGPGOUT]);
+                __this_cpu_inc(memcg->stat->events[MEM_CGROUP_EVENTS_PGPGOUT]);
                 nr_pages = -nr_pages; /* for event */
         }
 
-        __this_cpu_add(mem->stat->events[MEM_CGROUP_EVENTS_COUNT], nr_pages);
+        __this_cpu_add(memcg->stat->events[MEM_CGROUP_EVENTS_COUNT], nr_pages);
 
         preempt_enable();
 }
 
 unsigned long
-mem_cgroup_zone_nr_lru_pages(struct mem_cgroup *mem, int nid, int zid,
+mem_cgroup_zone_nr_lru_pages(struct mem_cgroup *memcg, int nid, int zid,
                         unsigned int lru_mask)
 {
         struct mem_cgroup_per_zone *mz;
         enum lru_list l;
         unsigned long ret = 0;
 
-        mz = mem_cgroup_zoneinfo(mem, nid, zid);
+        mz = mem_cgroup_zoneinfo(memcg, nid, zid);
 
         for_each_lru(l) {
                 if (BIT(l) & lru_mask)
@@ -656,44 +658,45 @@ mem_cgroup_zone_nr_lru_pages(struct mem_cgroup *mem, int nid, int zid,
 }
 
 static unsigned long
-mem_cgroup_node_nr_lru_pages(struct mem_cgroup *mem,
+mem_cgroup_node_nr_lru_pages(struct mem_cgroup *memcg,
                         int nid, unsigned int lru_mask)
 {
         u64 total = 0;
         int zid;
 
         for (zid = 0; zid < MAX_NR_ZONES; zid++)
-                total += mem_cgroup_zone_nr_lru_pages(mem, nid, zid, lru_mask);
+                total += mem_cgroup_zone_nr_lru_pages(memcg,
+                                                nid, zid, lru_mask);
 
         return total;
 }
 
-static unsigned long mem_cgroup_nr_lru_pages(struct mem_cgroup *mem,
+static unsigned long mem_cgroup_nr_lru_pages(struct mem_cgroup *memcg,
                         unsigned int lru_mask)
 {
         int nid;
         u64 total = 0;
 
         for_each_node_state(nid, N_HIGH_MEMORY)
-                total += mem_cgroup_node_nr_lru_pages(mem, nid, lru_mask);
+                total += mem_cgroup_node_nr_lru_pages(memcg, nid, lru_mask);
         return total;
 }
 
-static bool __memcg_event_check(struct mem_cgroup *mem, int target)
+static bool __memcg_event_check(struct mem_cgroup *memcg, int target)
 {
         unsigned long val, next;
 
-        val = this_cpu_read(mem->stat->events[MEM_CGROUP_EVENTS_COUNT]);
-        next = this_cpu_read(mem->stat->targets[target]);
+        val = __this_cpu_read(memcg->stat->events[MEM_CGROUP_EVENTS_COUNT]);
+        next = __this_cpu_read(memcg->stat->targets[target]);
         /* from time_after() in jiffies.h */
         return ((long)next - (long)val < 0);
 }
 
-static void __mem_cgroup_target_update(struct mem_cgroup *mem, int target)
+static void __mem_cgroup_target_update(struct mem_cgroup *memcg, int target)
 {
         unsigned long val, next;
 
-        val = this_cpu_read(mem->stat->events[MEM_CGROUP_EVENTS_COUNT]);
+        val = __this_cpu_read(memcg->stat->events[MEM_CGROUP_EVENTS_COUNT]);
 
         switch (target) {
         case MEM_CGROUP_TARGET_THRESH:
@@ -709,34 +712,36 @@ static void __mem_cgroup_target_update(struct mem_cgroup *mem, int target)
                 return;
         }
 
-        this_cpu_write(mem->stat->targets[target], next);
+        __this_cpu_write(memcg->stat->targets[target], next);
 }
 
 /*
  * Check events in order.
  *
  */
-static void memcg_check_events(struct mem_cgroup *mem, struct page *page)
+static void memcg_check_events(struct mem_cgroup *memcg, struct page *page)
 {
+        preempt_disable();
         /* threshold event is triggered in finer grain than soft limit */
-        if (unlikely(__memcg_event_check(mem, MEM_CGROUP_TARGET_THRESH))) {
-                mem_cgroup_threshold(mem);
-                __mem_cgroup_target_update(mem, MEM_CGROUP_TARGET_THRESH);
-                if (unlikely(__memcg_event_check(mem,
+        if (unlikely(__memcg_event_check(memcg, MEM_CGROUP_TARGET_THRESH))) {
+                mem_cgroup_threshold(memcg);
+                __mem_cgroup_target_update(memcg, MEM_CGROUP_TARGET_THRESH);
+                if (unlikely(__memcg_event_check(memcg,
                              MEM_CGROUP_TARGET_SOFTLIMIT))) {
-                        mem_cgroup_update_tree(mem, page);
-                        __mem_cgroup_target_update(mem,
+                        mem_cgroup_update_tree(memcg, page);
+                        __mem_cgroup_target_update(memcg,
                                                    MEM_CGROUP_TARGET_SOFTLIMIT);
                 }
 #if MAX_NUMNODES > 1
-                if (unlikely(__memcg_event_check(mem,
+                if (unlikely(__memcg_event_check(memcg,
                         MEM_CGROUP_TARGET_NUMAINFO))) {
-                        atomic_inc(&mem->numainfo_events);
-                        __mem_cgroup_target_update(mem,
+                        atomic_inc(&memcg->numainfo_events);
+                        __mem_cgroup_target_update(memcg,
                                 MEM_CGROUP_TARGET_NUMAINFO);
                 }
 #endif
         }
+        preempt_enable();
 }
 
 static struct mem_cgroup *mem_cgroup_from_cont(struct cgroup *cont)
@@ -762,7 +767,7 @@ struct mem_cgroup *mem_cgroup_from_task(struct task_struct *p)
 
 struct mem_cgroup *try_get_mem_cgroup_from_mm(struct mm_struct *mm)
 {
-        struct mem_cgroup *mem = NULL;
+        struct mem_cgroup *memcg = NULL;
 
         if (!mm)
                 return NULL;
@@ -773,25 +778,25 @@ struct mem_cgroup *try_get_mem_cgroup_from_mm(struct mm_struct *mm)
          */
         rcu_read_lock();
         do {
-                mem = mem_cgroup_from_task(rcu_dereference(mm->owner));
-                if (unlikely(!mem))
+                memcg = mem_cgroup_from_task(rcu_dereference(mm->owner));
+                if (unlikely(!memcg))
                         break;
-        } while (!css_tryget(&mem->css));
+        } while (!css_tryget(&memcg->css));
         rcu_read_unlock();
-        return mem;
+        return memcg;
 }
 
 /* The caller has to guarantee "mem" exists before calling this */
-static struct mem_cgroup *mem_cgroup_start_loop(struct mem_cgroup *mem)
+static struct mem_cgroup *mem_cgroup_start_loop(struct mem_cgroup *memcg)
 {
         struct cgroup_subsys_state *css;
         int found;
 
-        if (!mem) /* ROOT cgroup has the smallest ID */
+        if (!memcg) /* ROOT cgroup has the smallest ID */
                 return root_mem_cgroup; /*css_put/get against root is ignored*/
-        if (!mem->use_hierarchy) {
-                if (css_tryget(&mem->css))
-                        return mem;
+        if (!memcg->use_hierarchy) {
+                if (css_tryget(&memcg->css))
+                        return memcg;
                 return NULL;
         }
         rcu_read_lock();
@@ -799,13 +804,13 @@ static struct mem_cgroup *mem_cgroup_start_loop(struct mem_cgroup *mem)
          * searching a memory cgroup which has the smallest ID under given
          * ROOT cgroup. (ID >= 1)
          */
-        css = css_get_next(&mem_cgroup_subsys, 1, &mem->css, &found);
+        css = css_get_next(&mem_cgroup_subsys, 1, &memcg->css, &found);
         if (css && css_tryget(css))
-                mem = container_of(css, struct mem_cgroup, css);
+                memcg = container_of(css, struct mem_cgroup, css);
         else
-                mem = NULL;
+                memcg = NULL;
         rcu_read_unlock();
-        return mem;
+        return memcg;
 }
 
 static struct mem_cgroup *mem_cgroup_get_next(struct mem_cgroup *iter,
@@ -859,29 +864,29 @@ static struct mem_cgroup *mem_cgroup_get_next(struct mem_cgroup *iter,
         for_each_mem_cgroup_tree_cond(iter, NULL, true)
 
 
-static inline bool mem_cgroup_is_root(struct mem_cgroup *mem)
+static inline bool mem_cgroup_is_root(struct mem_cgroup *memcg)
 {
-        return (mem == root_mem_cgroup);
+        return (memcg == root_mem_cgroup);
 }
 
 void mem_cgroup_count_vm_event(struct mm_struct *mm, enum vm_event_item idx)
 {
-        struct mem_cgroup *mem;
+        struct mem_cgroup *memcg;
 
         if (!mm)
                 return;
 
         rcu_read_lock();
-        mem = mem_cgroup_from_task(rcu_dereference(mm->owner));
-        if (unlikely(!mem))
+        memcg = mem_cgroup_from_task(rcu_dereference(mm->owner));
+        if (unlikely(!memcg))
                 goto out;
 
         switch (idx) {
         case PGMAJFAULT:
-                mem_cgroup_pgmajfault(mem, 1);
+                mem_cgroup_pgmajfault(memcg, 1);
                 break;
         case PGFAULT:
-                mem_cgroup_pgfault(mem, 1);
+                mem_cgroup_pgfault(memcg, 1);
                 break;
         default:
                 BUG();
@@ -990,6 +995,16 @@ void mem_cgroup_add_lru_list(struct page *page, enum lru_list lru)
                 return;
         pc = lookup_page_cgroup(page);
         VM_BUG_ON(PageCgroupAcctLRU(pc));
+        /*
+         * putback:                             charge:
+         * SetPageLRU                           SetPageCgroupUsed
+         * smp_mb                               smp_mb
+         * PageCgroupUsed && add to memcg LRU   PageLRU && add to memcg LRU
+         *
+         * Ensure that one of the two sides adds the page to the memcg
+         * LRU during a race.
+         */
+        smp_mb();
         if (!PageCgroupUsed(pc))
                 return;
         /* Ensure pc->mem_cgroup is visible after reading PCG_USED. */
@@ -1041,7 +1056,16 @@ static void mem_cgroup_lru_add_after_commit(struct page *page)
         unsigned long flags;
         struct zone *zone = page_zone(page);
         struct page_cgroup *pc = lookup_page_cgroup(page);
-
+        /*
+         * putback:                             charge:
+         * SetPageLRU                           SetPageCgroupUsed
+         * smp_mb                               smp_mb
+         * PageCgroupUsed && add to memcg LRU   PageLRU && add to memcg LRU
+         *
+         * Ensure that one of the two sides adds the page to the memcg
+         * LRU during a race.
+         */
+        smp_mb();
         /* taking care of that the page is added to LRU while we commit it */
         if (likely(!PageLRU(page)))
                 return;
@@ -1063,21 +1087,21 @@ void mem_cgroup_move_lists(struct page *page,
 }
 
 /*
- * Checks whether given mem is same or in the root_mem's
+ * Checks whether given mem is same or in the root_mem_cgroup's
  * hierarchy subtree
  */
-static bool mem_cgroup_same_or_subtree(const struct mem_cgroup *root_mem,
-                struct mem_cgroup *mem)
+static bool mem_cgroup_same_or_subtree(const struct mem_cgroup *root_memcg,
+                struct mem_cgroup *memcg)
 {
-        if (root_mem != mem) {
-                return (root_mem->use_hierarchy &&
-                        css_is_ancestor(&mem->css, &root_mem->css));
+        if (root_memcg != memcg) {
+                return (root_memcg->use_hierarchy &&
+                        css_is_ancestor(&memcg->css, &root_memcg->css));
         }
 
         return true;
 }
 
-int task_in_mem_cgroup(struct task_struct *task, const struct mem_cgroup *mem)
+int task_in_mem_cgroup(struct task_struct *task, const struct mem_cgroup *memcg)
 {
         int ret;
         struct mem_cgroup *curr = NULL;
@@ -1091,25 +1115,29 @@ int task_in_mem_cgroup(struct task_struct *task, const struct mem_cgroup *mem)
         if (!curr)
                 return 0;
         /*
-         * We should check use_hierarchy of "mem" not "curr". Because checking
+         * We should check use_hierarchy of "memcg" not "curr". Because checking
          * use_hierarchy of "curr" here make this function true if hierarchy is
-         * enabled in "curr" and "curr" is a child of "mem" in *cgroup*
-         * hierarchy(even if use_hierarchy is disabled in "mem").
+         * enabled in "curr" and "curr" is a child of "memcg" in *cgroup*
+         * hierarchy(even if use_hierarchy is disabled in "memcg").
          */
-        ret = mem_cgroup_same_or_subtree(mem, curr);
+        ret = mem_cgroup_same_or_subtree(memcg, curr);
         css_put(&curr->css);
         return ret;
 }
 
-static int calc_inactive_ratio(struct mem_cgroup *memcg, unsigned long *present_pages)
+int mem_cgroup_inactive_anon_is_low(struct mem_cgroup *memcg, struct zone *zone)
 {
-        unsigned long active;
+        unsigned long inactive_ratio;
+        int nid = zone_to_nid(zone);
+        int zid = zone_idx(zone);
         unsigned long inactive;
+        unsigned long active;
         unsigned long gb;
-        unsigned long inactive_ratio;
 
-        inactive = mem_cgroup_nr_lru_pages(memcg, BIT(LRU_INACTIVE_ANON));
-        active = mem_cgroup_nr_lru_pages(memcg, BIT(LRU_ACTIVE_ANON));
+        inactive = mem_cgroup_zone_nr_lru_pages(memcg, nid, zid,
+                                                BIT(LRU_INACTIVE_ANON));
+        active = mem_cgroup_zone_nr_lru_pages(memcg, nid, zid,
+                                              BIT(LRU_ACTIVE_ANON));
 
         gb = (inactive + active) >> (30 - PAGE_SHIFT);
         if (gb)
@@ -1117,39 +1145,20 @@ static int calc_inactive_ratio(struct mem_cgroup *memcg, unsigned long *present_
         else
                 inactive_ratio = 1;
 
-        if (present_pages) {
-                present_pages[0] = inactive;
-                present_pages[1] = active;
-        }
-
-        return inactive_ratio;
+        return inactive * inactive_ratio < active;
 }
 
-int mem_cgroup_inactive_anon_is_low(struct mem_cgroup *memcg)
-{
-        unsigned long active;
-        unsigned long inactive;
-        unsigned long present_pages[2];
-        unsigned long inactive_ratio;
-
-        inactive_ratio = calc_inactive_ratio(memcg, present_pages);
-
-        inactive = present_pages[0];
-        active = present_pages[1];
-
-        if (inactive * inactive_ratio < active)
-                return 1;
-
-        return 0;
-}
-
-int mem_cgroup_inactive_file_is_low(struct mem_cgroup *memcg)
+int mem_cgroup_inactive_file_is_low(struct mem_cgroup *memcg, struct zone *zone)
 {
         unsigned long active;
         unsigned long inactive;
+        int zid = zone_idx(zone);
+        int nid = zone_to_nid(zone);
 
-        inactive = mem_cgroup_nr_lru_pages(memcg, BIT(LRU_INACTIVE_FILE));
-        active = mem_cgroup_nr_lru_pages(memcg, BIT(LRU_ACTIVE_FILE));
+        inactive = mem_cgroup_zone_nr_lru_pages(memcg, nid, zid,
+                                                BIT(LRU_INACTIVE_FILE));
+        active = mem_cgroup_zone_nr_lru_pages(memcg, nid, zid,
+                                              BIT(LRU_ACTIVE_FILE));
 
         return (active > inactive);
 }
@@ -1254,13 +1263,13 @@ unsigned long mem_cgroup_isolate_pages(unsigned long nr_to_scan,
  * Returns the maximum amount of memory @mem can be charged with, in
  * pages.
  */
-static unsigned long mem_cgroup_margin(struct mem_cgroup *mem)
+static unsigned long mem_cgroup_margin(struct mem_cgroup *memcg)
 {
         unsigned long long margin;
 
-        margin = res_counter_margin(&mem->res);
+        margin = res_counter_margin(&memcg->res);
         if (do_swap_account)
-                margin = min(margin, res_counter_margin(&mem->memsw));
+                margin = min(margin, res_counter_margin(&memcg->memsw));
         return margin >> PAGE_SHIFT;
 }
 
@@ -1275,33 +1284,33 @@ int mem_cgroup_swappiness(struct mem_cgroup *memcg)
         return memcg->swappiness;
 }
 
-static void mem_cgroup_start_move(struct mem_cgroup *mem)
+static void mem_cgroup_start_move(struct mem_cgroup *memcg)
 {
         int cpu;
 
         get_online_cpus();
-        spin_lock(&mem->pcp_counter_lock);
+        spin_lock(&memcg->pcp_counter_lock);
         for_each_online_cpu(cpu)
-                per_cpu(mem->stat->count[MEM_CGROUP_ON_MOVE], cpu) += 1;
-        mem->nocpu_base.count[MEM_CGROUP_ON_MOVE] += 1;
-        spin_unlock(&mem->pcp_counter_lock);
+                per_cpu(memcg->stat->count[MEM_CGROUP_ON_MOVE], cpu) += 1;
+        memcg->nocpu_base.count[MEM_CGROUP_ON_MOVE] += 1;
+        spin_unlock(&memcg->pcp_counter_lock);
         put_online_cpus();
 
         synchronize_rcu();
 }
 
-static void mem_cgroup_end_move(struct mem_cgroup *mem)
+static void mem_cgroup_end_move(struct mem_cgroup *memcg)
 {
         int cpu;
 
-        if (!mem)
+        if (!memcg)
                 return;
         get_online_cpus();
-        spin_lock(&mem->pcp_counter_lock);
+        spin_lock(&memcg->pcp_counter_lock);
         for_each_online_cpu(cpu)
-                per_cpu(mem->stat->count[MEM_CGROUP_ON_MOVE], cpu) -= 1;
-        mem->nocpu_base.count[MEM_CGROUP_ON_MOVE] -= 1;
-        spin_unlock(&mem->pcp_counter_lock);
+                per_cpu(memcg->stat->count[MEM_CGROUP_ON_MOVE], cpu) -= 1;
+        memcg->nocpu_base.count[MEM_CGROUP_ON_MOVE] -= 1;
+        spin_unlock(&memcg->pcp_counter_lock);
         put_online_cpus();
 }
 /*
@@ -1316,13 +1325,13 @@ static void mem_cgroup_end_move(struct mem_cgroup *mem)
  *                        waiting at hith-memory prressure caused by "move".
  */
 
-static bool mem_cgroup_stealed(struct mem_cgroup *mem)
+static bool mem_cgroup_stealed(struct mem_cgroup *memcg)
 {
         VM_BUG_ON(!rcu_read_lock_held());
-        return this_cpu_read(mem->stat->count[MEM_CGROUP_ON_MOVE]) > 0;
+        return this_cpu_read(memcg->stat->count[MEM_CGROUP_ON_MOVE]) > 0;
 }
 
-static bool mem_cgroup_under_move(struct mem_cgroup *mem)
+static bool mem_cgroup_under_move(struct mem_cgroup *memcg)
 {
         struct mem_cgroup *from;
         struct mem_cgroup *to;
@@ -1337,17 +1346,17 @@ static bool mem_cgroup_under_move(struct mem_cgroup *mem)
         if (!from)
                 goto unlock;
 
-        ret = mem_cgroup_same_or_subtree(mem, from)
-                || mem_cgroup_same_or_subtree(mem, to);
+        ret = mem_cgroup_same_or_subtree(memcg, from)
+                || mem_cgroup_same_or_subtree(memcg, to);
 unlock:
         spin_unlock(&mc.lock);
         return ret;
 }
 
-static bool mem_cgroup_wait_acct_move(struct mem_cgroup *mem)
+static bool mem_cgroup_wait_acct_move(struct mem_cgroup *memcg)
 {
         if (mc.moving_task && current != mc.moving_task) {
-                if (mem_cgroup_under_move(mem)) {
+                if (mem_cgroup_under_move(memcg)) {
                         DEFINE_WAIT(wait);
                         prepare_to_wait(&mc.waitq, &wait, TASK_INTERRUPTIBLE);
                         /* moving charge context might have finished. */
@@ -1431,12 +1440,12 @@ done:
  * This function returns the number of memcg under hierarchy tree. Returns
  * 1(self count) if no children.
  */
-static int mem_cgroup_count_children(struct mem_cgroup *mem)
+static int mem_cgroup_count_children(struct mem_cgroup *memcg)
 {
         int num = 0;
         struct mem_cgroup *iter;
 
-        for_each_mem_cgroup_tree(iter, mem)
+        for_each_mem_cgroup_tree(iter, memcg)
                 num++;
         return num;
 }
@@ -1466,21 +1475,21 @@ u64 mem_cgroup_get_limit(struct mem_cgroup *memcg)
  * that to reclaim free pages from.
  */
 static struct mem_cgroup *
-mem_cgroup_select_victim(struct mem_cgroup *root_mem)
+mem_cgroup_select_victim(struct mem_cgroup *root_memcg)
 {
         struct mem_cgroup *ret = NULL;
         struct cgroup_subsys_state *css;
         int nextid, found;
 
-        if (!root_mem->use_hierarchy) {
-                css_get(&root_mem->css);
-                ret = root_mem;
+        if (!root_memcg->use_hierarchy) {
+                css_get(&root_memcg->css);
+                ret = root_memcg;
         }
 
         while (!ret) {
                 rcu_read_lock();
-                nextid = root_mem->last_scanned_child + 1;
-                css = css_get_next(&mem_cgroup_subsys, nextid, &root_mem->css,
+                nextid = root_memcg->last_scanned_child + 1;
+                css = css_get_next(&mem_cgroup_subsys, nextid, &root_memcg->css,
                                    &found);
                 if (css && css_tryget(css))
                         ret = container_of(css, struct mem_cgroup, css);
@@ -1489,9 +1498,9 @@ mem_cgroup_select_victim(struct mem_cgroup *root_mem)
                 /* Updates scanning parameter */
                 if (!css) {
                         /* this means start scan from ID:1 */
-                        root_mem->last_scanned_child = 0;
+                        root_memcg->last_scanned_child = 0;
                 } else
-                        root_mem->last_scanned_child = found;
+                        root_memcg->last_scanned_child = found;
         }
 
         return ret;
@@ -1507,14 +1516,14 @@ mem_cgroup_select_victim(struct mem_cgroup *root_mem)
  * reclaimable pages on a node. Returns true if there are any reclaimable
  * pages in the node.
  */
-static bool test_mem_cgroup_node_reclaimable(struct mem_cgroup *mem,
+static bool test_mem_cgroup_node_reclaimable(struct mem_cgroup *memcg,
                 int nid, bool noswap)
 {
-        if (mem_cgroup_node_nr_lru_pages(mem, nid, LRU_ALL_FILE))
+        if (mem_cgroup_node_nr_lru_pages(memcg, nid, LRU_ALL_FILE))
                 return true;
         if (noswap || !total_swap_pages)
                 return false;
-        if (mem_cgroup_node_nr_lru_pages(mem, nid, LRU_ALL_ANON))
+        if (mem_cgroup_node_nr_lru_pages(memcg, nid, LRU_ALL_ANON))
                 return true;
         return false;
 
@@ -1527,29 +1536,29 @@ static bool test_mem_cgroup_node_reclaimable(struct mem_cgroup *mem,
  * nodes based on the zonelist. So update the list loosely once per 10 secs.
  *
  */
-static void mem_cgroup_may_update_nodemask(struct mem_cgroup *mem)
+static void mem_cgroup_may_update_nodemask(struct mem_cgroup *memcg)
 {
         int nid;
         /*
          * numainfo_events > 0 means there was at least NUMAINFO_EVENTS_TARGET
          * pagein/pageout changes since the last update.
          */
-        if (!atomic_read(&mem->numainfo_events))
+        if (!atomic_read(&memcg->numainfo_events))
                 return;
-        if (atomic_inc_return(&mem->numainfo_updating) > 1)
+        if (atomic_inc_return(&memcg->numainfo_updating) > 1)
                 return;
 
         /* make a nodemask where this memcg uses memory from */
-        mem->scan_nodes = node_states[N_HIGH_MEMORY];
+        memcg->scan_nodes = node_states[N_HIGH_MEMORY];
 
         for_each_node_mask(nid, node_states[N_HIGH_MEMORY]) {
 
-                if (!test_mem_cgroup_node_reclaimable(mem, nid, false))
-                        node_clear(nid, mem->scan_nodes);
+                if (!test_mem_cgroup_node_reclaimable(memcg, nid, false))
+                        node_clear(nid, memcg->scan_nodes);
         }
 
-        atomic_set(&mem->numainfo_events, 0);
-        atomic_set(&mem->numainfo_updating, 0);
+        atomic_set(&memcg->numainfo_events, 0);
+        atomic_set(&memcg->numainfo_updating, 0);
 }
 
 /*
@@ -1564,16 +1573,16 @@ static void mem_cgroup_may_update_nodemask(struct mem_cgroup *mem)
  *
  * Now, we use round-robin. Better algorithm is welcomed.
  */
-int mem_cgroup_select_victim_node(struct mem_cgroup *mem)
+int mem_cgroup_select_victim_node(struct mem_cgroup *memcg)
 {
         int node;
 
-        mem_cgroup_may_update_nodemask(mem);
-        node = mem->last_scanned_node;
+        mem_cgroup_may_update_nodemask(memcg);
+        node = memcg->last_scanned_node;
 
-        node = next_node(node, mem->scan_nodes);
+        node = next_node(node, memcg->scan_nodes);
         if (node == MAX_NUMNODES)
-                node = first_node(mem->scan_nodes);
+                node = first_node(memcg->scan_nodes);
         /*
          * We call this when we hit limit, not when pages are added to LRU.
          * No LRU may hold pages because all pages are UNEVICTABLE or
@@ -1583,7 +1592,7 @@ int mem_cgroup_select_victim_node(struct mem_cgroup *mem)
         if (unlikely(node == MAX_NUMNODES))
                 node = numa_node_id();
 
-        mem->last_scanned_node = node;
+        memcg->last_scanned_node = node;
         return node;
 }
 
@@ -1593,7 +1602,7 @@ int mem_cgroup_select_victim_node(struct mem_cgroup *mem)
  * unused nodes. But scan_nodes is lazily updated and may not cotain
  * enough new information. We need to do double check.
  */
-bool mem_cgroup_reclaimable(struct mem_cgroup *mem, bool noswap)
+bool mem_cgroup_reclaimable(struct mem_cgroup *memcg, bool noswap)
 {
         int nid;
 
@@ -1601,12 +1610,12 @@ bool mem_cgroup_reclaimable(struct mem_cgroup *mem, bool noswap)
          * quick check...making use of scan_node.
          * We can skip unused nodes.
          */
-        if (!nodes_empty(mem->scan_nodes)) {
-                for (nid = first_node(mem->scan_nodes);
+        if (!nodes_empty(memcg->scan_nodes)) {
+                for (nid = first_node(memcg->scan_nodes);
                      nid < MAX_NUMNODES;
-                     nid = next_node(nid, mem->scan_nodes)) {
+                     nid = next_node(nid, memcg->scan_nodes)) {
 
-                        if (test_mem_cgroup_node_reclaimable(mem, nid, noswap))
+                        if (test_mem_cgroup_node_reclaimable(memcg, nid, noswap))
                                 return true;
                 }
         }
@@ -1614,23 +1623,23 @@ bool mem_cgroup_reclaimable(struct mem_cgroup *mem, bool noswap)
          * Check rest of nodes.
          */
         for_each_node_state(nid, N_HIGH_MEMORY) {
-                if (node_isset(nid, mem->scan_nodes))
+                if (node_isset(nid, memcg->scan_nodes))
                         continue;
-                if (test_mem_cgroup_node_reclaimable(mem, nid, noswap))
+                if (test_mem_cgroup_node_reclaimable(memcg, nid, noswap))
                         return true;
         }
         return false;
 }
 
 #else
-int mem_cgroup_select_victim_node(struct mem_cgroup *mem)
+int mem_cgroup_select_victim_node(struct mem_cgroup *memcg)
 {
         return 0;
 }
 
-bool mem_cgroup_reclaimable(struct mem_cgroup *mem, bool noswap)
+bool mem_cgroup_reclaimable(struct mem_cgroup *memcg, bool noswap)
 {
-        return test_mem_cgroup_node_reclaimable(mem, 0, noswap);
+        return test_mem_cgroup_node_reclaimable(memcg, 0, noswap);
 }
 #endif
 
@@ -1639,14 +1648,14 @@ bool mem_cgroup_reclaimable(struct mem_cgroup *mem, bool noswap)
  * we reclaimed from, so that we don't end up penalizing one child extensively
  * based on its position in the children list.
  *
- * root_mem is the original ancestor that we've been reclaim from.
+ * root_memcg is the original ancestor that we've been reclaim from.
  *
- * We give up and return to the caller when we visit root_mem twice.
+ * We give up and return to the caller when we visit root_memcg twice.
  * (other groups can be removed while we're walking....)
  *
  * If shrink==true, for avoiding to free too much, this returns immedieately.
  */
-static int mem_cgroup_hierarchical_reclaim(struct mem_cgroup *root_mem,
+static int mem_cgroup_hierarchical_reclaim(struct mem_cgroup *root_memcg,
                                                 struct zone *zone,
                                                 gfp_t gfp_mask,
                                                 unsigned long reclaim_options,
@@ -1661,15 +1670,15 @@ static int mem_cgroup_hierarchical_reclaim(struct mem_cgroup *root_mem,
         unsigned long excess;
         unsigned long nr_scanned;
 
-        excess = res_counter_soft_limit_excess(&root_mem->res) >> PAGE_SHIFT;
+        excess = res_counter_soft_limit_excess(&root_memcg->res) >> PAGE_SHIFT;
 
         /* If memsw_is_minimum==1, swap-out is of-no-use. */
-        if (!check_soft && !shrink && root_mem->memsw_is_minimum)
+        if (!check_soft && !shrink && root_memcg->memsw_is_minimum)
                 noswap = true;
 
         while (1) {
-                victim = mem_cgroup_select_victim(root_mem);
-                if (victim == root_mem) {
+                victim = mem_cgroup_select_victim(root_memcg);
+                if (victim == root_memcg) {
                         loop++;
                         /*
                          * We are not draining per cpu cached charges during
@@ -1678,7 +1687,7 @@ static int mem_cgroup_hierarchical_reclaim(struct mem_cgroup *root_mem,
                          * charges will not give any.
                          */
                         if (!check_soft && loop >= 1)
-                                drain_all_stock_async(root_mem);
+                                drain_all_stock_async(root_memcg);
                         if (loop >= 2) {
                                 /*
                                  * If we have not been able to reclaim
@@ -1725,9 +1734,9 @@ static int mem_cgroup_hierarchical_reclaim(struct mem_cgroup *root_mem,
                         return ret;
                 total += ret;
                 if (check_soft) {
-                        if (!res_counter_soft_limit_excess(&root_mem->res))
+                        if (!res_counter_soft_limit_excess(&root_memcg->res))
                                 return total;
-                } else if (mem_cgroup_margin(root_mem))
+                } else if (mem_cgroup_margin(root_memcg))
                         return total;
         }
         return total;
@@ -1738,12 +1747,12 @@ static int mem_cgroup_hierarchical_reclaim(struct mem_cgroup *root_mem,
  * If someone is running, return false.
  * Has to be called with memcg_oom_lock
  */
-static bool mem_cgroup_oom_lock(struct mem_cgroup *mem)
+static bool mem_cgroup_oom_lock(struct mem_cgroup *memcg)
 {
         struct mem_cgroup *iter, *failed = NULL;
         bool cond = true;
 
-        for_each_mem_cgroup_tree_cond(iter, mem, cond) {
+        for_each_mem_cgroup_tree_cond(iter, memcg, cond) {
                 if (iter->oom_lock) {
                         /*
                          * this subtree of our hierarchy is already locked
@@ -1763,7 +1772,7 @@ static bool mem_cgroup_oom_lock(struct mem_cgroup *mem)
          * what we set up to the failing subtree
          */
         cond = true;
-        for_each_mem_cgroup_tree_cond(iter, mem, cond) {
+        for_each_mem_cgroup_tree_cond(iter, memcg, cond) {
                 if (iter == failed) {
                         cond = false;
                         continue;
@@ -1776,24 +1785,24 @@ static bool mem_cgroup_oom_lock(struct mem_cgroup *mem)
 /*
  * Has to be called with memcg_oom_lock
  */
-static int mem_cgroup_oom_unlock(struct mem_cgroup *mem)
+static int mem_cgroup_oom_unlock(struct mem_cgroup *memcg)
 {
         struct mem_cgroup *iter;
 
-        for_each_mem_cgroup_tree(iter, mem)
+        for_each_mem_cgroup_tree(iter, memcg)
                 iter->oom_lock = false;
         return 0;
 }
 
-static void mem_cgroup_mark_under_oom(struct mem_cgroup *mem)
+static void mem_cgroup_mark_under_oom(struct mem_cgroup *memcg)
 {
         struct mem_cgroup *iter;
 
-        for_each_mem_cgroup_tree(iter, mem)
+        for_each_mem_cgroup_tree(iter, memcg)
                 atomic_inc(&iter->under_oom);
 }
 
-static void mem_cgroup_unmark_under_oom(struct mem_cgroup *mem)
+static void mem_cgroup_unmark_under_oom(struct mem_cgroup *memcg)
 {
         struct mem_cgroup *iter;
 
@@ -1802,7 +1811,7 @@ static void mem_cgroup_unmark_under_oom(struct mem_cgroup *mem)
          * mem_cgroup_oom_lock() may not be called. We have to use
          * atomic_add_unless() here.
          */
-        for_each_mem_cgroup_tree(iter, mem)
+        for_each_mem_cgroup_tree(iter, memcg)
                 atomic_add_unless(&iter->under_oom, -1, 0);
 }
 
@@ -1817,85 +1826,85 @@ struct oom_wait_info {
 static int memcg_oom_wake_function(wait_queue_t *wait,
         unsigned mode, int sync, void *arg)
 {
-        struct mem_cgroup *wake_mem = (struct mem_cgroup *)arg,
-                          *oom_wait_mem;
+        struct mem_cgroup *wake_memcg = (struct mem_cgroup *)arg,
+                          *oom_wait_memcg;
         struct oom_wait_info *oom_wait_info;
 
         oom_wait_info = container_of(wait, struct oom_wait_info, wait);
-        oom_wait_mem = oom_wait_info->mem;
+        oom_wait_memcg = oom_wait_info->mem;
 
         /*
          * Both of oom_wait_info->mem and wake_mem are stable under us.
          * Then we can use css_is_ancestor without taking care of RCU.
          */
-        if (!mem_cgroup_same_or_subtree(oom_wait_mem, wake_mem)
-                        && !mem_cgroup_same_or_subtree(wake_mem, oom_wait_mem))
+        if (!mem_cgroup_same_or_subtree(oom_wait_memcg, wake_memcg)
+                && !mem_cgroup_same_or_subtree(wake_memcg, oom_wait_memcg))
                 return 0;
         return autoremove_wake_function(wait, mode, sync, arg);
 }
 
-static void memcg_wakeup_oom(struct mem_cgroup *mem)
+static void memcg_wakeup_oom(struct mem_cgroup *memcg)
 {
-        /* for filtering, pass "mem" as argument. */
-        __wake_up(&memcg_oom_waitq, TASK_NORMAL, 0, mem);
+        /* for filtering, pass "memcg" as argument. */
+        __wake_up(&memcg_oom_waitq, TASK_NORMAL, 0, memcg);
 }
 
-static void memcg_oom_recover(struct mem_cgroup *mem)
+static void memcg_oom_recover(struct mem_cgroup *memcg)
 {
-        if (mem && atomic_read(&mem->under_oom))
-                memcg_wakeup_oom(mem);
+        if (memcg && atomic_read(&memcg->under_oom))
+                memcg_wakeup_oom(memcg);
 }
 
 /*
  * try to call OOM killer. returns false if we should exit memory-reclaim loop.
  */
-bool mem_cgroup_handle_oom(struct mem_cgroup *mem, gfp_t mask)
+bool mem_cgroup_handle_oom(struct mem_cgroup *memcg, gfp_t mask)
 {
         struct oom_wait_info owait;
         bool locked, need_to_kill;
 
-        owait.mem = mem;
+        owait.mem = memcg;
         owait.wait.flags = 0;
         owait.wait.func = memcg_oom_wake_function;
         owait.wait.private = current;
         INIT_LIST_HEAD(&owait.wait.task_list);
         need_to_kill = true;
-        mem_cgroup_mark_under_oom(mem);
+        mem_cgroup_mark_under_oom(memcg);
 
-        /* At first, try to OOM lock hierarchy under mem.*/
+        /* At first, try to OOM lock hierarchy under memcg.*/
         spin_lock(&memcg_oom_lock);
-        locked = mem_cgroup_oom_lock(mem);
+        locked = mem_cgroup_oom_lock(memcg);
         /*
          * Even if signal_pending(), we can't quit charge() loop without
          * accounting. So, UNINTERRUPTIBLE is appropriate. But SIGKILL
          * under OOM is always welcomed, use TASK_KILLABLE here.
          */
         prepare_to_wait(&memcg_oom_waitq, &owait.wait, TASK_KILLABLE);
-        if (!locked || mem->oom_kill_disable)
+        if (!locked || memcg->oom_kill_disable)
                 need_to_kill = false;
         if (locked)
-                mem_cgroup_oom_notify(mem);
+                mem_cgroup_oom_notify(memcg);
         spin_unlock(&memcg_oom_lock);
 
         if (need_to_kill) {
                 finish_wait(&memcg_oom_waitq, &owait.wait);
-                mem_cgroup_out_of_memory(mem, mask);
+                mem_cgroup_out_of_memory(memcg, mask);
         } else {
                 schedule();
                 finish_wait(&memcg_oom_waitq, &owait.wait);
         }
         spin_lock(&memcg_oom_lock);
         if (locked)
-                mem_cgroup_oom_unlock(mem);
-        memcg_wakeup_oom(mem);
+                mem_cgroup_oom_unlock(memcg);
+        memcg_wakeup_oom(memcg);
         spin_unlock(&memcg_oom_lock);
 
-        mem_cgroup_unmark_under_oom(mem);
+        mem_cgroup_unmark_under_oom(memcg);
 
         if (test_thread_flag(TIF_MEMDIE) || fatal_signal_pending(current))
                 return false;
         /* Give chance to dying process */
-        schedule_timeout(1);
+        schedule_timeout_uninterruptible(1);
         return true;
 }
 
@@ -1926,7 +1935,7 @@ bool mem_cgroup_handle_oom(struct mem_cgroup *mem, gfp_t mask)
 void mem_cgroup_update_page_stat(struct page *page,
                                  enum mem_cgroup_page_stat_item idx, int val)
 {
-        struct mem_cgroup *mem;
+        struct mem_cgroup *memcg;
         struct page_cgroup *pc = lookup_page_cgroup(page);
         bool need_unlock = false;
         unsigned long uninitialized_var(flags);
@@ -1935,16 +1944,16 @@ void mem_cgroup_update_page_stat(struct page *page,
                 return;
 
         rcu_read_lock();
-        mem = pc->mem_cgroup;
-        if (unlikely(!mem || !PageCgroupUsed(pc)))
+        memcg = pc->mem_cgroup;
+        if (unlikely(!memcg || !PageCgroupUsed(pc)))
                 goto out;
         /* pc->mem_cgroup is unstable ? */
-        if (unlikely(mem_cgroup_stealed(mem)) || PageTransHuge(page)) {
+        if (unlikely(mem_cgroup_stealed(memcg)) || PageTransHuge(page)) {
                 /* take a lock against to access pc->mem_cgroup */
                 move_lock_page_cgroup(pc, &flags);
                 need_unlock = true;
-                mem = pc->mem_cgroup;
-                if (!mem || !PageCgroupUsed(pc))
+                memcg = pc->mem_cgroup;
+                if (!memcg || !PageCgroupUsed(pc))
                         goto out;
         }
 
@@ -1960,7 +1969,7 @@ void mem_cgroup_update_page_stat(struct page *page,
                 BUG();
         }
 
-        this_cpu_add(mem->stat->count[idx], val);
+        this_cpu_add(memcg->stat->count[idx], val);
 
 out:
         if (unlikely(need_unlock))
@@ -1991,13 +2000,13 @@ static DEFINE_MUTEX(percpu_charge_mutex);
  * cgroup which is not current target, returns false. This stock will be
  * refilled.
  */
-static bool consume_stock(struct mem_cgroup *mem)
+static bool consume_stock(struct mem_cgroup *memcg)
 {
         struct memcg_stock_pcp *stock;
         bool ret = true;
 
         stock = &get_cpu_var(memcg_stock);
-        if (mem == stock->cached && stock->nr_pages)
+        if (memcg == stock->cached && stock->nr_pages)
                 stock->nr_pages--;
         else /* need to call res_counter_charge */
                 ret = false;
@@ -2038,24 +2047,24 @@ static void drain_local_stock(struct work_struct *dummy)
  * Cache charges(val) which is from res_counter, to local per_cpu area.
  * This will be consumed by consume_stock() function, later.
  */
-static void refill_stock(struct mem_cgroup *mem, unsigned int nr_pages)
+static void refill_stock(struct mem_cgroup *memcg, unsigned int nr_pages)
 {
         struct memcg_stock_pcp *stock = &get_cpu_var(memcg_stock);
 
-        if (stock->cached != mem) { /* reset if necessary */
+        if (stock->cached != memcg) { /* reset if necessary */
                 drain_stock(stock);
-                stock->cached = mem;
+                stock->cached = memcg;
         }
         stock->nr_pages += nr_pages;
         put_cpu_var(memcg_stock);
 }
 
 /*
- * Drains all per-CPU charge caches for given root_mem resp. subtree
+ * Drains all per-CPU charge caches for given root_memcg resp. subtree
  * of the hierarchy under it. sync flag says whether we should block
  * until the work is done.
  */
-static void drain_all_stock(struct mem_cgroup *root_mem, bool sync)
+static void drain_all_stock(struct mem_cgroup *root_memcg, bool sync)
 {
         int cpu, curcpu;
 
@@ -2064,12 +2073,12 @@ static void drain_all_stock(struct mem_cgroup *root_mem, bool sync)
         curcpu = get_cpu();
         for_each_online_cpu(cpu) {
                 struct memcg_stock_pcp *stock = &per_cpu(memcg_stock, cpu);
-                struct mem_cgroup *mem;
+                struct mem_cgroup *memcg;
 
-                mem = stock->cached;
-                if (!mem || !stock->nr_pages)
+                memcg = stock->cached;
+                if (!memcg || !stock->nr_pages)
                         continue;
-                if (!mem_cgroup_same_or_subtree(root_mem, mem))
+                if (!mem_cgroup_same_or_subtree(root_memcg, memcg))
                         continue;
                 if (!test_and_set_bit(FLUSHING_CACHED_CHARGE, &stock->flags)) {
                         if (cpu == curcpu)
@@ -2098,23 +2107,23 @@ out:
  * expects some charges will be back to res_counter later but cannot wait for
  * it.
  */
-static void drain_all_stock_async(struct mem_cgroup *root_mem)
+static void drain_all_stock_async(struct mem_cgroup *root_memcg)
 {
         /*
          * If someone calls draining, avoid adding more kworker runs.
          */
         if (!mutex_trylock(&percpu_charge_mutex))
                 return;
-        drain_all_stock(root_mem, false);
+        drain_all_stock(root_memcg, false);
         mutex_unlock(&percpu_charge_mutex);
 }
 
 /* This is a synchronous drain interface. */
-static void drain_all_stock_sync(struct mem_cgroup *root_mem)
+static void drain_all_stock_sync(struct mem_cgroup *root_memcg)
 {
         /* called when force_empty is called */
         mutex_lock(&percpu_charge_mutex);
-        drain_all_stock(root_mem, true);
+        drain_all_stock(root_memcg, true);
         mutex_unlock(&percpu_charge_mutex);
 }
 
@@ -2122,35 +2131,35 @@ static void drain_all_stock_sync(struct mem_cgroup *root_mem)
  * This function drains percpu counter value from DEAD cpu and
  * move it to local cpu. Note that this function can be preempted.
  */
-static void mem_cgroup_drain_pcp_counter(struct mem_cgroup *mem, int cpu)
+static void mem_cgroup_drain_pcp_counter(struct mem_cgroup *memcg, int cpu)
 {
         int i;
 
-        spin_lock(&mem->pcp_counter_lock);
+        spin_lock(&memcg->pcp_counter_lock);
         for (i = 0; i < MEM_CGROUP_STAT_DATA; i++) {
-                long x = per_cpu(mem->stat->count[i], cpu);
+                long x = per_cpu(memcg->stat->count[i], cpu);
 
-                per_cpu(mem->stat->count[i], cpu) = 0;
-                mem->nocpu_base.count[i] += x;
+                per_cpu(memcg->stat->count[i], cpu) = 0;
+                memcg->nocpu_base.count[i] += x;
         }
         for (i = 0; i < MEM_CGROUP_EVENTS_NSTATS; i++) {
-                unsigned long x = per_cpu(mem->stat->events[i], cpu);
+                unsigned long x = per_cpu(memcg->stat->events[i], cpu);
 
-                per_cpu(mem->stat->events[i], cpu) = 0;
-                mem->nocpu_base.events[i] += x;
+                per_cpu(memcg->stat->events[i], cpu) = 0;
+                memcg->nocpu_base.events[i] += x;
         }
         /* need to clear ON_MOVE value, works as a kind of lock. */
-        per_cpu(mem->stat->count[MEM_CGROUP_ON_MOVE], cpu) = 0;
-        spin_unlock(&mem->pcp_counter_lock);
+        per_cpu(memcg->stat->count[MEM_CGROUP_ON_MOVE], cpu) = 0;
+        spin_unlock(&memcg->pcp_counter_lock);
 }
 
-static void synchronize_mem_cgroup_on_move(struct mem_cgroup *mem, int cpu)
+static void synchronize_mem_cgroup_on_move(struct mem_cgroup *memcg, int cpu)
 {
         int idx = MEM_CGROUP_ON_MOVE;
 
-        spin_lock(&mem->pcp_counter_lock);
-        per_cpu(mem->stat->count[idx], cpu) = mem->nocpu_base.count[idx];
-        spin_unlock(&mem->pcp_counter_lock);
+        spin_lock(&memcg->pcp_counter_lock);
+        per_cpu(memcg->stat->count[idx], cpu) = memcg->nocpu_base.count[idx];
+        spin_unlock(&memcg->pcp_counter_lock);
 }
 
 static int __cpuinit memcg_cpu_hotplug_callback(struct notifier_block *nb,
@@ -2188,7 +2197,7 @@ enum {
         CHARGE_OOM_DIE,         /* the current is killed because of OOM */
 };
 
-static int mem_cgroup_do_charge(struct mem_cgroup *mem, gfp_t gfp_mask,
+static int mem_cgroup_do_charge(struct mem_cgroup *memcg, gfp_t gfp_mask,
                                 unsigned int nr_pages, bool oom_check)
 {
         unsigned long csize = nr_pages * PAGE_SIZE;
@@ -2197,16 +2206,16 @@ static int mem_cgroup_do_charge(struct mem_cgroup *mem, gfp_t gfp_mask,
         unsigned long flags = 0;
         int ret;
 
-        ret = res_counter_charge(&mem->res, csize, &fail_res);
+        ret = res_counter_charge(&memcg->res, csize, &fail_res);
 
         if (likely(!ret)) {
                 if (!do_swap_account)
                         return CHARGE_OK;
-                ret = res_counter_charge(&mem->memsw, csize, &fail_res);
+                ret = res_counter_charge(&memcg->memsw, csize, &fail_res);
                 if (likely(!ret))
                         return CHARGE_OK;
 
-                res_counter_uncharge(&mem->res, csize);
+                res_counter_uncharge(&memcg->res, csize);
                 mem_over_limit = mem_cgroup_from_res_counter(fail_res, memsw);
                 flags |= MEM_CGROUP_RECLAIM_NOSWAP;
         } else
@@ -2264,12 +2273,12 @@ static int mem_cgroup_do_charge(struct mem_cgroup *mem, gfp_t gfp_mask,
 static int __mem_cgroup_try_charge(struct mm_struct *mm,
                                    gfp_t gfp_mask,
                                    unsigned int nr_pages,
-                                   struct mem_cgroup **memcg,
+                                   struct mem_cgroup **ptr,
                                    bool oom)
 {
         unsigned int batch = max(CHARGE_BATCH, nr_pages);
         int nr_oom_retries = MEM_CGROUP_RECLAIM_RETRIES;
-        struct mem_cgroup *mem = NULL;
+        struct mem_cgroup *memcg = NULL;
         int ret;
 
         /*
@@ -2287,17 +2296,17 @@ static int __mem_cgroup_try_charge(struct mm_struct *mm,
          * thread group leader migrates. It's possible that mm is not
          * set, if so charge the init_mm (happens for pagecache usage).
          */
-        if (!*memcg && !mm)
+        if (!*ptr && !mm)
                 goto bypass;
 again:
-        if (*memcg) { /* css should be a valid one */
-                mem = *memcg;
-                VM_BUG_ON(css_is_removed(&mem->css));
-                if (mem_cgroup_is_root(mem))
+        if (*ptr) { /* css should be a valid one */
+                memcg = *ptr;
+                VM_BUG_ON(css_is_removed(&memcg->css));
+                if (mem_cgroup_is_root(memcg))
                         goto done;
-                if (nr_pages == 1 && consume_stock(mem))
+                if (nr_pages == 1 && consume_stock(memcg))
                         goto done;
-                css_get(&mem->css);
+                css_get(&memcg->css);
         } else {
                 struct task_struct *p;
 
@@ -2305,7 +2314,7 @@ again:
                 p = rcu_dereference(mm->owner);
                 /*
                  * Because we don't have task_lock(), "p" can exit.
-                 * In that case, "mem" can point to root or p can be NULL with
+                 * In that case, "memcg" can point to root or p can be NULL with
                  * race with swapoff. Then, we have small risk of mis-accouning.
                  * But such kind of mis-account by race always happens because
                  * we don't have cgroup_mutex(). It's overkill and we allo that
@@ -2313,12 +2322,12 @@ again:
                  * (*) swapoff at el will charge against mm-struct not against
                  * task-struct. So, mm->owner can be NULL.
                  */
-                mem = mem_cgroup_from_task(p);
-                if (!mem || mem_cgroup_is_root(mem)) {
+                memcg = mem_cgroup_from_task(p);
+                if (!memcg || mem_cgroup_is_root(memcg)) {
                         rcu_read_unlock();
                         goto done;
                 }
-                if (nr_pages == 1 && consume_stock(mem)) {
+                if (nr_pages == 1 && consume_stock(memcg)) {
                         /*
                          * It seems dagerous to access memcg without css_get().
                          * But considering how consume_stok works, it's not
@@ -2331,7 +2340,7 @@ again:
                         goto done;
                 }
                 /* after here, we may be blocked. we need to get refcnt */
-                if (!css_tryget(&mem->css)) {
+                if (!css_tryget(&memcg->css)) {
                         rcu_read_unlock();
                         goto again;
                 }
@@ -2343,7 +2352,7 @@ again:
 
                 /* If killed, bypass charge */
                 if (fatal_signal_pending(current)) {
-                        css_put(&mem->css);
+                        css_put(&memcg->css);
                         goto bypass;
                 }
 
@@ -2353,43 +2362,43 @@ again:
                         nr_oom_retries = MEM_CGROUP_RECLAIM_RETRIES;
                 }
 
-                ret = mem_cgroup_do_charge(mem, gfp_mask, batch, oom_check);
+                ret = mem_cgroup_do_charge(memcg, gfp_mask, batch, oom_check);
                 switch (ret) {
                 case CHARGE_OK:
                         break;
                 case CHARGE_RETRY: /* not in OOM situation but retry */
                         batch = nr_pages;
-                        css_put(&mem->css);
-                        mem = NULL;
+                        css_put(&memcg->css);
+                        memcg = NULL;
                         goto again;
                 case CHARGE_WOULDBLOCK: /* !__GFP_WAIT */
-                        css_put(&mem->css);
+                        css_put(&memcg->css);
                         goto nomem;
                 case CHARGE_NOMEM: /* OOM routine works */
                         if (!oom) {
-                                css_put(&mem->css);
+                                css_put(&memcg->css);
                                 goto nomem;
                         }
                         /* If oom, we never return -ENOMEM */
                         nr_oom_retries--;
                         break;
                 case CHARGE_OOM_DIE: /* Killed by OOM Killer */
-                        css_put(&mem->css);
+                        css_put(&memcg->css);
                         goto bypass;
                 }
         } while (ret != CHARGE_OK);
 
         if (batch > nr_pages)
-                refill_stock(mem, batch - nr_pages);
-        css_put(&mem->css);
+                refill_stock(memcg, batch - nr_pages);
+        css_put(&memcg->css);
 done:
-        *memcg = mem;
+        *ptr = memcg;
         return 0;
 nomem:
-        *memcg = NULL;
+        *ptr = NULL;
         return -ENOMEM;
 bypass:
-        *memcg = NULL;
+        *ptr = NULL;
         return 0;
 }
 
@@ -2398,15 +2407,15 @@ bypass:
  * This function is for that and do uncharge, put css's refcnt.
  * gotten by try_charge().
  */
-static void __mem_cgroup_cancel_charge(struct mem_cgroup *mem,
+static void __mem_cgroup_cancel_charge(struct mem_cgroup *memcg,
                                        unsigned int nr_pages)
 {
-        if (!mem_cgroup_is_root(mem)) {
+        if (!mem_cgroup_is_root(memcg)) {
                 unsigned long bytes = nr_pages * PAGE_SIZE;
 
-                res_counter_uncharge(&mem->res, bytes);
+                res_counter_uncharge(&memcg->res, bytes);
                 if (do_swap_account)
-                        res_counter_uncharge(&mem->memsw, bytes);
+                        res_counter_uncharge(&memcg->memsw, bytes);
         }
 }
 
@@ -2431,7 +2440,7 @@ static struct mem_cgroup *mem_cgroup_lookup(unsigned short id)
 
 struct mem_cgroup *try_get_mem_cgroup_from_page(struct page *page)
 {
-        struct mem_cgroup *mem = NULL;
+        struct mem_cgroup *memcg = NULL;
         struct page_cgroup *pc;
         unsigned short id;
         swp_entry_t ent;
@@ -2441,23 +2450,23 @@ struct mem_cgroup *try_get_mem_cgroup_from_page(struct page *page)
         pc = lookup_page_cgroup(page);
         lock_page_cgroup(pc);
         if (PageCgroupUsed(pc)) {
-                mem = pc->mem_cgroup;
-                if (mem && !css_tryget(&mem->css))
-                        mem = NULL;
+                memcg = pc->mem_cgroup;
+                if (memcg && !css_tryget(&memcg->css))
+                        memcg = NULL;
         } else if (PageSwapCache(page)) {
                 ent.val = page_private(page);
                 id = lookup_swap_cgroup(ent);
                 rcu_read_lock();
-                mem = mem_cgroup_lookup(id);
-                if (mem && !css_tryget(&mem->css))
-                        mem = NULL;
+                memcg = mem_cgroup_lookup(id);
+                if (memcg && !css_tryget(&memcg->css))
+                        memcg = NULL;
                 rcu_read_unlock();
         }
         unlock_page_cgroup(pc);
-        return mem;
+        return memcg;
 }
 
-static void __mem_cgroup_commit_charge(struct mem_cgroup *mem,
+static void __mem_cgroup_commit_charge(struct mem_cgroup *memcg,
                                        struct page *page,
                                        unsigned int nr_pages,
                                        struct page_cgroup *pc,
@@ -2466,14 +2475,14 @@ static void __mem_cgroup_commit_charge(struct mem_cgroup *mem,
         lock_page_cgroup(pc);
         if (unlikely(PageCgroupUsed(pc))) {
                 unlock_page_cgroup(pc);
-                __mem_cgroup_cancel_charge(mem, nr_pages);
+                __mem_cgroup_cancel_charge(memcg, nr_pages);
                 return;
         }
         /*
          * we don't need page_cgroup_lock about tail pages, becase they are not
          * accessed by any other context at this point.
          */
-        pc->mem_cgroup = mem;
+        pc->mem_cgroup = memcg;
         /*
          * We access a page_cgroup asynchronously without lock_page_cgroup().
          * Especially when a page_cgroup is taken from a page, pc->mem_cgroup
@@ -2496,14 +2505,14 @@ static void __mem_cgroup_commit_charge(struct mem_cgroup *mem,
                 break;
         }
 
-        mem_cgroup_charge_statistics(mem, PageCgroupCache(pc), nr_pages);
+        mem_cgroup_charge_statistics(memcg, PageCgroupCache(pc), nr_pages);
         unlock_page_cgroup(pc);
         /*
          * "charge_statistics" updated event counter. Then, check it.
          * Insert ancestor (and ancestor's ancestors), to softlimit RB-tree.
          * if they exceeds softlimit.
          */
-        memcg_check_events(mem, page);
+        memcg_check_events(memcg, page);
 }
 
 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
@@ -2690,7 +2699,7 @@ out:
 static int mem_cgroup_charge_common(struct page *page, struct mm_struct *mm,
                                 gfp_t gfp_mask, enum charge_type ctype)
 {
-        struct mem_cgroup *mem = NULL;
+        struct mem_cgroup *memcg = NULL;
         unsigned int nr_pages = 1;
         struct page_cgroup *pc;
         bool oom = true;
@@ -2709,11 +2718,11 @@ static int mem_cgroup_charge_common(struct page *page, struct mm_struct *mm,
         pc = lookup_page_cgroup(page);
         BUG_ON(!pc); /* XXX: remove this and move pc lookup into commit */
 
-        ret = __mem_cgroup_try_charge(mm, gfp_mask, nr_pages, &mem, oom);
-        if (ret || !mem)
+        ret = __mem_cgroup_try_charge(mm, gfp_mask, nr_pages, &memcg, oom);
+        if (ret || !memcg)
                 return ret;
 
-        __mem_cgroup_commit_charge(mem, page, nr_pages, pc, ctype);
+        __mem_cgroup_commit_charge(memcg, page, nr_pages, pc, ctype);
         return 0;
 }
 
@@ -2742,7 +2751,7 @@ __mem_cgroup_commit_charge_swapin(struct page *page, struct mem_cgroup *ptr,
                                         enum charge_type ctype);
 
 static void
-__mem_cgroup_commit_charge_lrucare(struct page *page, struct mem_cgroup *mem,
+__mem_cgroup_commit_charge_lrucare(struct page *page, struct mem_cgroup *memcg,
                                         enum charge_type ctype)
 {
         struct page_cgroup *pc = lookup_page_cgroup(page);
@@ -2752,7 +2761,7 @@ __mem_cgroup_commit_charge_lrucare(struct page *page, struct mem_cgroup *mem,
          * LRU. Take care of it.
          */
         mem_cgroup_lru_del_before_commit(page);
-        __mem_cgroup_commit_charge(mem, page, 1, pc, ctype);
+        __mem_cgroup_commit_charge(memcg, page, 1, pc, ctype);
         mem_cgroup_lru_add_after_commit(page);
         return;
 }
@@ -2760,7 +2769,7 @@ __mem_cgroup_commit_charge_lrucare(struct page *page, struct mem_cgroup *mem,
 int mem_cgroup_cache_charge(struct page *page, struct mm_struct *mm,
                                 gfp_t gfp_mask)
 {
-        struct mem_cgroup *mem = NULL;
+        struct mem_cgroup *memcg = NULL;
         int ret;
 
         if (mem_cgroup_disabled())
@@ -2772,8 +2781,8 @@ int mem_cgroup_cache_charge(struct page *page, struct mm_struct *mm,
                 mm = &init_mm;
 
         if (page_is_file_cache(page)) {
-                ret = __mem_cgroup_try_charge(mm, gfp_mask, 1, &mem, true);
-                if (ret || !mem)
+                ret = __mem_cgroup_try_charge(mm, gfp_mask, 1, &memcg, true);
+                if (ret || !memcg)
                         return ret;
 
                 /*
@@ -2781,15 +2790,15 @@ int mem_cgroup_cache_charge(struct page *page, struct mm_struct *mm,
                  * put that would remove them from the LRU list, make
                  * sure that they get relinked properly.
                  */
-                __mem_cgroup_commit_charge_lrucare(page, mem,
+                __mem_cgroup_commit_charge_lrucare(page, memcg,
                                         MEM_CGROUP_CHARGE_TYPE_CACHE);
                 return ret;
         }
         /* shmem */
         if (PageSwapCache(page)) {
-                ret = mem_cgroup_try_charge_swapin(mm, page, gfp_mask, &mem);
+                ret = mem_cgroup_try_charge_swapin(mm, page, gfp_mask, &memcg);
                 if (!ret)
-                        __mem_cgroup_commit_charge_swapin(page, mem,
+                        __mem_cgroup_commit_charge_swapin(page, memcg,
                                         MEM_CGROUP_CHARGE_TYPE_SHMEM);
         } else
                 ret = mem_cgroup_charge_common(page, mm, gfp_mask,
@@ -2808,7 +2817,7 @@ int mem_cgroup_try_charge_swapin(struct mm_struct *mm,
                                  struct page *page,
                                  gfp_t mask, struct mem_cgroup **ptr)
 {
-        struct mem_cgroup *mem;
+        struct mem_cgroup *memcg;
         int ret;
 
         *ptr = NULL;
@@ -2826,12 +2835,12 @@ int mem_cgroup_try_charge_swapin(struct mm_struct *mm,
          */
         if (!PageSwapCache(page))
                 goto charge_cur_mm;
-        mem = try_get_mem_cgroup_from_page(page);
-        if (!mem)
+        memcg = try_get_mem_cgroup_from_page(page);
+        if (!memcg)
                 goto charge_cur_mm;
-        *ptr = mem;
+        *ptr = memcg;
         ret = __mem_cgroup_try_charge(NULL, mask, 1, ptr, true);
-        css_put(&mem->css);
+        css_put(&memcg->css);
         return ret;
 charge_cur_mm:
         if (unlikely(!mm))
@@ -2891,16 +2900,16 @@ void mem_cgroup_commit_charge_swapin(struct page *page, struct mem_cgroup *ptr)
                                         MEM_CGROUP_CHARGE_TYPE_MAPPED);
 }
 
-void mem_cgroup_cancel_charge_swapin(struct mem_cgroup *mem)
+void mem_cgroup_cancel_charge_swapin(struct mem_cgroup *memcg)
 {
         if (mem_cgroup_disabled())
                 return;
-        if (!mem)
+        if (!memcg)
                 return;
-        __mem_cgroup_cancel_charge(mem, 1);
+        __mem_cgroup_cancel_charge(memcg, 1);
 }
 
-static void mem_cgroup_do_uncharge(struct mem_cgroup *mem,
+static void mem_cgroup_do_uncharge(struct mem_cgroup *memcg,
                                    unsigned int nr_pages,
                                    const enum charge_type ctype)
 {
@@ -2918,7 +2927,7 @@ static void mem_cgroup_do_uncharge(struct mem_cgroup *mem,
          * uncharges. Then, it's ok to ignore memcg's refcnt.
          */
         if (!batch->memcg)
-                batch->memcg = mem;
+                batch->memcg = memcg;
         /*
          * do_batch > 0 when unmapping pages or inode invalidate/truncate.
          * In those cases, all pages freed continuously can be expected to be in
@@ -2938,7 +2947,7 @@ static void mem_cgroup_do_uncharge(struct mem_cgroup *mem,
          * merge a series of uncharges to an uncharge of res_counter.
          * If not, we uncharge res_counter ony by one.
          */
-        if (batch->memcg != mem)
+        if (batch->memcg != memcg)
                 goto direct_uncharge;
         /* remember freed charge and uncharge it later */
         batch->nr_pages++;
@@ -2946,11 +2955,11 @@ static void mem_cgroup_do_uncharge(struct mem_cgroup *mem,
                 batch->memsw_nr_pages++;
         return;
 direct_uncharge:
-        res_counter_uncharge(&mem->res, nr_pages * PAGE_SIZE);
+        res_counter_uncharge(&memcg->res, nr_pages * PAGE_SIZE);
         if (uncharge_memsw)
-                res_counter_uncharge(&mem->memsw, nr_pages * PAGE_SIZE);
-        if (unlikely(batch->memcg != mem))
-                memcg_oom_recover(mem);
+                res_counter_uncharge(&memcg->memsw, nr_pages * PAGE_SIZE);
+        if (unlikely(batch->memcg != memcg))
+                memcg_oom_recover(memcg);
         return;
 }
 
@@ -2960,7 +2969,7 @@ direct_uncharge:
 static struct mem_cgroup *
 __mem_cgroup_uncharge_common(struct page *page, enum charge_type ctype)
 {
-        struct mem_cgroup *mem = NULL;
+        struct mem_cgroup *memcg = NULL;
         unsigned int nr_pages = 1;
         struct page_cgroup *pc;
 
@@ -2983,7 +2992,7 @@ __mem_cgroup_uncharge_common(struct page *page, enum charge_type ctype)
 
         lock_page_cgroup(pc);
 
-        mem = pc->mem_cgroup;
+        memcg = pc->mem_cgroup;
 
         if (!PageCgroupUsed(pc))
                 goto unlock_out;
@@ -3006,7 +3015,7 @@ __mem_cgroup_uncharge_common(struct page *page, enum charge_type ctype)
                 break;
         }
 
-        mem_cgroup_charge_statistics(mem, PageCgroupCache(pc), -nr_pages);
+        mem_cgroup_charge_statistics(memcg, PageCgroupCache(pc), -nr_pages);
 
         ClearPageCgroupUsed(pc);
         /*
@@ -3018,18 +3027,18 @@ __mem_cgroup_uncharge_common(struct page *page, enum charge_type ctype)
 
         unlock_page_cgroup(pc);
         /*
-         * even after unlock, we have mem->res.usage here and this memcg
+         * even after unlock, we have memcg->res.usage here and this memcg
          * will never be freed.
          */
-        memcg_check_events(mem, page);
+        memcg_check_events(memcg, page);
         if (do_swap_account && ctype == MEM_CGROUP_CHARGE_TYPE_SWAPOUT) {
-                mem_cgroup_swap_statistics(mem, true);
-                mem_cgroup_get(mem);
+                mem_cgroup_swap_statistics(memcg, true);
+                mem_cgroup_get(memcg);
         }
-        if (!mem_cgroup_is_root(mem))
-                mem_cgroup_do_uncharge(mem, nr_pages, ctype);
+        if (!mem_cgroup_is_root(memcg))
+                mem_cgroup_do_uncharge(memcg, nr_pages, ctype);
 
-        return mem;
+        return memcg;
 
 unlock_out:
         unlock_page_cgroup(pc);
@@ -3219,7 +3228,7 @@ static inline int mem_cgroup_move_swap_account(swp_entry_t entry,
 int mem_cgroup_prepare_migration(struct page *page,
         struct page *newpage, struct mem_cgroup **ptr, gfp_t gfp_mask)
 {
-        struct mem_cgroup *mem = NULL;
+        struct mem_cgroup *memcg = NULL;
         struct page_cgroup *pc;
         enum charge_type ctype;
         int ret = 0;
@@ -3233,8 +3242,8 @@ int mem_cgroup_prepare_migration(struct page *page,
         pc = lookup_page_cgroup(page);
         lock_page_cgroup(pc);
         if (PageCgroupUsed(pc)) {
-                mem = pc->mem_cgroup;
-                css_get(&mem->css);
+                memcg = pc->mem_cgroup;
+                css_get(&memcg->css);
                 /*
                  * At migrating an anonymous page, its mapcount goes down
                  * to 0 and uncharge() will be called. But, even if it's fully
@@ -3272,12 +3281,12 @@ int mem_cgroup_prepare_migration(struct page *page,
          * If the page is not charged at this point,
          * we return here.
          */
-        if (!mem)
+        if (!memcg)
                 return 0;
 
-        *ptr = mem;
+        *ptr = memcg;
         ret = __mem_cgroup_try_charge(NULL, gfp_mask, 1, ptr, false);
-        css_put(&mem->css);/* drop extra refcnt */
+        css_put(&memcg->css);/* drop extra refcnt */
         if (ret || *ptr == NULL) {
                 if (PageAnon(page)) {
                         lock_page_cgroup(pc);
@@ -3303,21 +3312,21 @@ int mem_cgroup_prepare_migration(struct page *page,
                 ctype = MEM_CGROUP_CHARGE_TYPE_CACHE;
         else
                 ctype = MEM_CGROUP_CHARGE_TYPE_SHMEM;
-        __mem_cgroup_commit_charge(mem, page, 1, pc, ctype);
+        __mem_cgroup_commit_charge(memcg, page, 1, pc, ctype);
         return ret;
 }
 
 /* remove redundant charge if migration failed*/
-void mem_cgroup_end_migration(struct mem_cgroup *mem,
+void mem_cgroup_end_migration(struct mem_cgroup *memcg,
         struct page *oldpage, struct page *newpage, bool migration_ok)
 {
         struct page *used, *unused;
         struct page_cgroup *pc;
 
-        if (!mem)
+        if (!memcg)
                 return;
         /* blocks rmdir() */
-        cgroup_exclude_rmdir(&mem->css);
+        cgroup_exclude_rmdir(&memcg->css);
         if (!migration_ok) {
                 used = oldpage;
                 unused = newpage;
@@ -3353,7 +3362,7 @@ void mem_cgroup_end_migration(struct mem_cgroup *mem,
          * So, rmdir()->pre_destroy() can be called while we do this charge.
          * In that case, we need to call pre_destroy() again. check it here.
          */
-        cgroup_release_and_wakeup_rmdir(&mem->css);
+        cgroup_release_and_wakeup_rmdir(&memcg->css);
 }
 
 #ifdef CONFIG_DEBUG_VM
@@ -3432,7 +3441,7 @@ static int mem_cgroup_resize_limit(struct mem_cgroup *memcg,
                 /*
                  * Rather than hide all in some function, I do this in
                  * open coded manner. You see what this really does.
-                 * We have to guarantee mem->res.limit < mem->memsw.limit.
+                 * We have to guarantee memcg->res.limit < memcg->memsw.limit.
                  */
                 mutex_lock(&set_limit_mutex);
                 memswlimit = res_counter_read_u64(&memcg->memsw, RES_LIMIT);
@@ -3494,7 +3503,7 @@ static int mem_cgroup_resize_memsw_limit(struct mem_cgroup *memcg,
                 /*
                  * Rather than hide all in some function, I do this in
                  * open coded manner. You see what this really does.
-                 * We have to guarantee mem->res.limit < mem->memsw.limit.
+                 * We have to guarantee memcg->res.limit < memcg->memsw.limit.
                  */
                 mutex_lock(&set_limit_mutex);
                 memlimit = res_counter_read_u64(&memcg->res, RES_LIMIT);
@@ -3632,7 +3641,7 @@ unsigned long mem_cgroup_soft_limit_reclaim(struct zone *zone, int order,
  * This routine traverse page_cgroup in given list and drop them all.
  * *And* this routine doesn't reclaim page itself, just removes page_cgroup.
  */
-static int mem_cgroup_force_empty_list(struct mem_cgroup *mem,
+static int mem_cgroup_force_empty_list(struct mem_cgroup *memcg,
                                 int node, int zid, enum lru_list lru)
 {
         struct zone *zone;
@@ -3643,7 +3652,7 @@ static int mem_cgroup_force_empty_list(struct mem_cgroup *mem,
         int ret = 0;
 
         zone = &NODE_DATA(node)->node_zones[zid];
-        mz = mem_cgroup_zoneinfo(mem, node, zid);
+        mz = mem_cgroup_zoneinfo(memcg, node, zid);
         list = &mz->lists[lru];
 
         loop = MEM_CGROUP_ZSTAT(mz, lru);
@@ -3670,7 +3679,7 @@ static int mem_cgroup_force_empty_list(struct mem_cgroup *mem,
 
                 page = lookup_cgroup_page(pc);
 
-                ret = mem_cgroup_move_parent(page, pc, mem, GFP_KERNEL);
+                ret = mem_cgroup_move_parent(page, pc, memcg, GFP_KERNEL);
                 if (ret == -ENOMEM)
                         break;
 
@@ -3691,14 +3700,14 @@ static int mem_cgroup_force_empty_list(struct mem_cgroup *mem,
  * make mem_cgroup's charge to be 0 if there is no task.
  * This enables deleting this mem_cgroup.
  */
-static int mem_cgroup_force_empty(struct mem_cgroup *mem, bool free_all)
+static int mem_cgroup_force_empty(struct mem_cgroup *memcg, bool free_all)
 {
         int ret;
         int node, zid, shrink;
         int nr_retries = MEM_CGROUP_RECLAIM_RETRIES;
-        struct cgroup *cgrp = mem->css.cgroup;
+        struct cgroup *cgrp = memcg->css.cgroup;
 
-        css_get(&mem->css);
+        css_get(&memcg->css);
 
         shrink = 0;
         /* should free all ? */
@@ -3714,14 +3723,14 @@ move_account:
                         goto out;
                 /* This is for making all *used* pages to be on LRU. */
                 lru_add_drain_all();
-                drain_all_stock_sync(mem);
+                drain_all_stock_sync(memcg);
                 ret = 0;
-                mem_cgroup_start_move(mem);
+                mem_cgroup_start_move(memcg);
                 for_each_node_state(node, N_HIGH_MEMORY) {
                         for (zid = 0; !ret && zid < MAX_NR_ZONES; zid++) {
                                 enum lru_list l;
                                 for_each_lru(l) {
-                                        ret = mem_cgroup_force_empty_list(mem,
+                                        ret = mem_cgroup_force_empty_list(memcg,
                                                         node, zid, l);
                                         if (ret)
                                                 break;
@@ -3730,16 +3739,16 @@ move_account:
                         if (ret)
                                 break;
                 }
-                mem_cgroup_end_move(mem);
-                memcg_oom_recover(mem);
+                mem_cgroup_end_move(memcg);
+                memcg_oom_recover(memcg);
                 /* it seems parent cgroup doesn't have enough mem */
                 if (ret == -ENOMEM)
                         goto try_to_free;
                 cond_resched();
         /* "ret" should also be checked to ensure all lists are empty. */
-        } while (mem->res.usage > 0 || ret);
+        } while (memcg->res.usage > 0 || ret);
 out:
-        css_put(&mem->css);
+        css_put(&memcg->css);
         return ret;
 
 try_to_free:
@@ -3752,14 +3761,14 @@ try_to_free:
         lru_add_drain_all();
         /* try to free all pages in this cgroup */
         shrink = 1;
-        while (nr_retries && mem->res.usage > 0) {
+        while (nr_retries && memcg->res.usage > 0) {
                 int progress;
 
                 if (signal_pending(current)) {
                         ret = -EINTR;
                         goto out;
                 }
-                progress = try_to_free_mem_cgroup_pages(mem, GFP_KERNEL,
+                progress = try_to_free_mem_cgroup_pages(memcg, GFP_KERNEL,
                                                 false);
                 if (!progress) {
                         nr_retries--;
@@ -3788,12 +3797,12 @@ static int mem_cgroup_hierarchy_write(struct cgroup *cont, struct cftype *cft,
                                         u64 val)
 {
         int retval = 0;
-        struct mem_cgroup *mem = mem_cgroup_from_cont(cont);
+        struct mem_cgroup *memcg = mem_cgroup_from_cont(cont);
         struct cgroup *parent = cont->parent;
-        struct mem_cgroup *parent_mem = NULL;
+        struct mem_cgroup *parent_memcg = NULL;
 
         if (parent)
-                parent_mem = mem_cgroup_from_cont(parent);
+                parent_memcg = mem_cgroup_from_cont(parent);
 
         cgroup_lock();
         /*
@@ -3804,10 +3813,10 @@ static int mem_cgroup_hierarchy_write(struct cgroup *cont, struct cftype *cft,
          * For the root cgroup, parent_mem is NULL, we allow value to be
          * set if there are no children.
          */
-        if ((!parent_mem || !parent_mem->use_hierarchy) &&
+        if ((!parent_memcg || !parent_memcg->use_hierarchy) &&
                                 (val == 1 || val == 0)) {
                 if (list_empty(&cont->children))
-                        mem->use_hierarchy = val;
+                        memcg->use_hierarchy = val;
                 else
                         retval = -EBUSY;
         } else
@@ -3818,14 +3827,14 @@ static int mem_cgroup_hierarchy_write(struct cgroup *cont, struct cftype *cft,
 }
 
 
-static unsigned long mem_cgroup_recursive_stat(struct mem_cgroup *mem,
+static unsigned long mem_cgroup_recursive_stat(struct mem_cgroup *memcg,
                                                enum mem_cgroup_stat_index idx)
 {
         struct mem_cgroup *iter;
         long val = 0;
 
         /* Per-cpu values can be negative, use a signed accumulator */
-        for_each_mem_cgroup_tree(iter, mem)
+        for_each_mem_cgroup_tree(iter, memcg)
                 val += mem_cgroup_read_stat(iter, idx);
 
         if (val < 0) /* race ? */
@@ -3833,29 +3842,29 @@ static unsigned long mem_cgroup_recursive_stat(struct mem_cgroup *mem,
         return val;
 }
 
-static inline u64 mem_cgroup_usage(struct mem_cgroup *mem, bool swap)
+static inline u64 mem_cgroup_usage(struct mem_cgroup *memcg, bool swap)
 {
         u64 val;
 
-        if (!mem_cgroup_is_root(mem)) {
+        if (!mem_cgroup_is_root(memcg)) {
                 if (!swap)
-                        return res_counter_read_u64(&mem->res, RES_USAGE);
+                        return res_counter_read_u64(&memcg->res, RES_USAGE);
                 else
-                        return res_counter_read_u64(&mem->memsw, RES_USAGE);
+                        return res_counter_read_u64(&memcg->memsw, RES_USAGE);
         }
 
-        val = mem_cgroup_recursive_stat(mem, MEM_CGROUP_STAT_CACHE);
-        val += mem_cgroup_recursive_stat(mem, MEM_CGROUP_STAT_RSS);
+        val = mem_cgroup_recursive_stat(memcg, MEM_CGROUP_STAT_CACHE);
+        val += mem_cgroup_recursive_stat(memcg, MEM_CGROUP_STAT_RSS);
 
         if (swap)
-                val += mem_cgroup_recursive_stat(mem, MEM_CGROUP_STAT_SWAPOUT);
+                val += mem_cgroup_recursive_stat(memcg, MEM_CGROUP_STAT_SWAPOUT);
 
         return val << PAGE_SHIFT;
 }
 
 static u64 mem_cgroup_read(struct cgroup *cont, struct cftype *cft)
 {
-        struct mem_cgroup *mem = mem_cgroup_from_cont(cont);
+        struct mem_cgroup *memcg = mem_cgroup_from_cont(cont);
         u64 val;
         int type, name;
 
@@ -3864,15 +3873,15 @@ static u64 mem_cgroup_read(struct cgroup *cont, struct cftype *cft)
         switch (type) {
         case _MEM:
                 if (name == RES_USAGE)
-                        val = mem_cgroup_usage(mem, false);
+                        val = mem_cgroup_usage(memcg, false);
                 else
-                        val = res_counter_read_u64(&mem->res, name);
+                        val = res_counter_read_u64(&memcg->res, name);
                 break;
         case _MEMSWAP:
                 if (name == RES_USAGE)
-                        val = mem_cgroup_usage(mem, true);
+                        val = mem_cgroup_usage(memcg, true);
                 else
-                        val = res_counter_read_u64(&mem->memsw, name);
+                        val = res_counter_read_u64(&memcg->memsw, name);
                 break;
         default:
                 BUG();
@@ -3960,24 +3969,24 @@ out:
 
 static int mem_cgroup_reset(struct cgroup *cont, unsigned int event)
 {
-        struct mem_cgroup *mem;
+        struct mem_cgroup *memcg;
         int type, name;
 
-        mem = mem_cgroup_from_cont(cont);
+        memcg = mem_cgroup_from_cont(cont);
         type = MEMFILE_TYPE(event);
         name = MEMFILE_ATTR(event);
         switch (name) {
         case RES_MAX_USAGE:
                 if (type == _MEM)
-                        res_counter_reset_max(&mem->res);
+                        res_counter_reset_max(&memcg->res);
                 else
-                        res_counter_reset_max(&mem->memsw);
+                        res_counter_reset_max(&memcg->memsw);
                 break;
         case RES_FAILCNT:
                 if (type == _MEM)
-                        res_counter_reset_failcnt(&mem->res);
+                        res_counter_reset_failcnt(&memcg->res);
                 else
-                        res_counter_reset_failcnt(&mem->memsw);
+                        res_counter_reset_failcnt(&memcg->memsw);
                 break;
         }
 
@@ -3994,7 +4003,7 @@ static u64 mem_cgroup_move_charge_read(struct cgroup *cgrp,
 static int mem_cgroup_move_charge_write(struct cgroup *cgrp,
                                         struct cftype *cft, u64 val)
 {
-        struct mem_cgroup *mem = mem_cgroup_from_cont(cgrp);
+        struct mem_cgroup *memcg = mem_cgroup_from_cont(cgrp);
 
         if (val >= (1 << NR_MOVE_TYPE))
                 return -EINVAL;
@@ -4004,7 +4013,7 @@ static int mem_cgroup_move_charge_write(struct cgroup *cgrp,
          * inconsistent.
          */
         cgroup_lock();
-        mem->move_charge_at_immigrate = val;
+        memcg->move_charge_at_immigrate = val;
         cgroup_unlock();
 
         return 0;
@@ -4061,49 +4070,49 @@ struct {
 
 
 static void
-mem_cgroup_get_local_stat(struct mem_cgroup *mem, struct mcs_total_stat *s)
+mem_cgroup_get_local_stat(struct mem_cgroup *memcg, struct mcs_total_stat *s)
 {
         s64 val;
 
         /* per cpu stat */
-        val = mem_cgroup_read_stat(mem, MEM_CGROUP_STAT_CACHE);
+        val = mem_cgroup_read_stat(memcg, MEM_CGROUP_STAT_CACHE);
         s->stat[MCS_CACHE] += val * PAGE_SIZE;
-        val = mem_cgroup_read_stat(mem, MEM_CGROUP_STAT_RSS);
+        val = mem_cgroup_read_stat(memcg, MEM_CGROUP_STAT_RSS);
         s->stat[MCS_RSS] += val * PAGE_SIZE;
-        val = mem_cgroup_read_stat(mem, MEM_CGROUP_STAT_FILE_MAPPED);
+        val = mem_cgroup_read_stat(memcg, MEM_CGROUP_STAT_FILE_MAPPED);
         s->stat[MCS_FILE_MAPPED] += val * PAGE_SIZE;
-        val = mem_cgroup_read_events(mem, MEM_CGROUP_EVENTS_PGPGIN);
+        val = mem_cgroup_read_events(memcg, MEM_CGROUP_EVENTS_PGPGIN);
         s->stat[MCS_PGPGIN] += val;
-        val = mem_cgroup_read_events(mem, MEM_CGROUP_EVENTS_PGPGOUT);
+        val = mem_cgroup_read_events(memcg, MEM_CGROUP_EVENTS_PGPGOUT);
         s->stat[MCS_PGPGOUT] += val;
         if (do_swap_account) {
-                val = mem_cgroup_read_stat(mem, MEM_CGROUP_STAT_SWAPOUT);
+                val = mem_cgroup_read_stat(memcg, MEM_CGROUP_STAT_SWAPOUT);
                 s->stat[MCS_SWAP] += val * PAGE_SIZE;
         }
-        val = mem_cgroup_read_events(mem, MEM_CGROUP_EVENTS_PGFAULT);
+        val = mem_cgroup_read_events(memcg, MEM_CGROUP_EVENTS_PGFAULT);
         s->stat[MCS_PGFAULT] += val;
-        val = mem_cgroup_read_events(mem, MEM_CGROUP_EVENTS_PGMAJFAULT);
+        val = mem_cgroup_read_events(memcg, MEM_CGROUP_EVENTS_PGMAJFAULT);
         s->stat[MCS_PGMAJFAULT] += val;
 
         /* per zone stat */
-        val = mem_cgroup_nr_lru_pages(mem, BIT(LRU_INACTIVE_ANON));
+        val = mem_cgroup_nr_lru_pages(memcg, BIT(LRU_INACTIVE_ANON));
         s->stat[MCS_INACTIVE_ANON] += val * PAGE_SIZE;
-        val = mem_cgroup_nr_lru_pages(mem, BIT(LRU_ACTIVE_ANON));
+        val = mem_cgroup_nr_lru_pages(memcg, BIT(LRU_ACTIVE_ANON));
         s->stat[MCS_ACTIVE_ANON] += val * PAGE_SIZE;
-        val = mem_cgroup_nr_lru_pages(mem, BIT(LRU_INACTIVE_FILE));
+        val = mem_cgroup_nr_lru_pages(memcg, BIT(LRU_INACTIVE_FILE));
         s->stat[MCS_INACTIVE_FILE] += val * PAGE_SIZE;
-        val = mem_cgroup_nr_lru_pages(mem, BIT(LRU_ACTIVE_FILE));
+        val = mem_cgroup_nr_lru_pages(memcg, BIT(LRU_ACTIVE_FILE));
         s->stat[MCS_ACTIVE_FILE] += val * PAGE_SIZE;
-        val = mem_cgroup_nr_lru_pages(mem, BIT(LRU_UNEVICTABLE));
+        val = mem_cgroup_nr_lru_pages(memcg, BIT(LRU_UNEVICTABLE));
         s->stat[MCS_UNEVICTABLE] += val * PAGE_SIZE;
 }
 
 static void
-mem_cgroup_get_total_stat(struct mem_cgroup *mem, struct mcs_total_stat *s)
+mem_cgroup_get_total_stat(struct mem_cgroup *memcg, struct mcs_total_stat *s)
 {
         struct mem_cgroup *iter;
 
-        for_each_mem_cgroup_tree(iter, mem)
+        for_each_mem_cgroup_tree(iter, memcg)
                 mem_cgroup_get_local_stat(iter, s);
 }
 
@@ -4189,8 +4198,6 @@ static int mem_control_stat_show(struct cgroup *cont, struct cftype *cft,
         }
 
 #ifdef CONFIG_DEBUG_VM
-        cb->fill(cb, "inactive_ratio", calc_inactive_ratio(mem_cont, NULL));
-
         {
                 int nid, zid;
                 struct mem_cgroup_per_zone *mz;
@@ -4327,20 +4334,20 @@ static int compare_thresholds(const void *a, const void *b)
         return _a->threshold - _b->threshold;
 }
 
-static int mem_cgroup_oom_notify_cb(struct mem_cgroup *mem)
+static int mem_cgroup_oom_notify_cb(struct mem_cgroup *memcg)
 {
         struct mem_cgroup_eventfd_list *ev;
 
-        list_for_each_entry(ev, &mem->oom_notify, list)
+        list_for_each_entry(ev, &memcg->oom_notify, list)
                 eventfd_signal(ev->eventfd, 1);
         return 0;
 }
 
-static void mem_cgroup_oom_notify(struct mem_cgroup *mem)
+static void mem_cgroup_oom_notify(struct mem_cgroup *memcg)
 {
         struct mem_cgroup *iter;
 
-        for_each_mem_cgroup_tree(iter, mem)
+        for_each_mem_cgroup_tree(iter, memcg)
                 mem_cgroup_oom_notify_cb(iter);
 }
 
@@ -4530,7 +4537,7 @@ static int mem_cgroup_oom_register_event(struct cgroup *cgrp,
 static void mem_cgroup_oom_unregister_event(struct cgroup *cgrp,
         struct cftype *cft, struct eventfd_ctx *eventfd)
 {
-        struct mem_cgroup *mem = mem_cgroup_from_cont(cgrp);
+        struct mem_cgroup *memcg = mem_cgroup_from_cont(cgrp);
         struct mem_cgroup_eventfd_list *ev, *tmp;
         int type = MEMFILE_TYPE(cft->private);
 
@@ -4538,7 +4545,7 @@ static void mem_cgroup_oom_unregister_event(struct cgroup *cgrp,
 
         spin_lock(&memcg_oom_lock);
 
-        list_for_each_entry_safe(ev, tmp, &mem->oom_notify, list) {
+        list_for_each_entry_safe(ev, tmp, &memcg->oom_notify, list) {
                 if (ev->eventfd == eventfd) {
                         list_del(&ev->list);
                         kfree(ev);
@@ -4551,11 +4558,11 @@ static void mem_cgroup_oom_unregister_event(struct cgroup *cgrp,
 static int mem_cgroup_oom_control_read(struct cgroup *cgrp,
         struct cftype *cft,  struct cgroup_map_cb *cb)
 {
-        struct mem_cgroup *mem = mem_cgroup_from_cont(cgrp);
+        struct mem_cgroup *memcg = mem_cgroup_from_cont(cgrp);
 
-        cb->fill(cb, "oom_kill_disable", mem->oom_kill_disable);
+        cb->fill(cb, "oom_kill_disable", memcg->oom_kill_disable);
 
-        if (atomic_read(&mem->under_oom))
+        if (atomic_read(&memcg->under_oom))
                 cb->fill(cb, "under_oom", 1);
         else
                 cb->fill(cb, "under_oom", 0);
@@ -4565,7 +4572,7 @@ static int mem_cgroup_oom_control_read(struct cgroup *cgrp,
 static int mem_cgroup_oom_control_write(struct cgroup *cgrp,
         struct cftype *cft, u64 val)
 {
-        struct mem_cgroup *mem = mem_cgroup_from_cont(cgrp);
+        struct mem_cgroup *memcg = mem_cgroup_from_cont(cgrp);
         struct mem_cgroup *parent;
 
         /* cannot set to root cgroup and only 0 and 1 are allowed */
@@ -4577,13 +4584,13 @@ static int mem_cgroup_oom_control_write(struct cgroup *cgrp,
         cgroup_lock();
         /* oom-kill-disable is a flag for subhierarchy. */
         if ((parent->use_hierarchy) ||
-            (mem->use_hierarchy && !list_empty(&cgrp->children))) {
+            (memcg->use_hierarchy && !list_empty(&cgrp->children))) {
                 cgroup_unlock();
                 return -EINVAL;
         }
-        mem->oom_kill_disable = val;
+        memcg->oom_kill_disable = val;
         if (!val)
-                memcg_oom_recover(mem);
+                memcg_oom_recover(memcg);
         cgroup_unlock();
         return 0;
 }
@@ -4719,7 +4726,7 @@ static int register_memsw_files(struct cgroup *cont, struct cgroup_subsys *ss)
 }
 #endif
 
-static int alloc_mem_cgroup_per_zone_info(struct mem_cgroup *mem, int node)
+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;
@@ -4739,21 +4746,21 @@ static int alloc_mem_cgroup_per_zone_info(struct mem_cgroup *mem, int node)
         if (!pn)
                 return 1;
 
-        mem->info.nodeinfo[node] = pn;
         for (zone = 0; zone < MAX_NR_ZONES; zone++) {
                 mz = &pn->zoneinfo[zone];
                 for_each_lru(l)
                         INIT_LIST_HEAD(&mz->lists[l]);
                 mz->usage_in_excess = 0;
                 mz->on_tree = false;
-                mz->mem = mem;
+                mz->mem = memcg;
         }
+        memcg->info.nodeinfo[node] = pn;
         return 0;
 }
 
-static void free_mem_cgroup_per_zone_info(struct mem_cgroup *mem, int node)
+static void free_mem_cgroup_per_zone_info(struct mem_cgroup *memcg, int node)
 {
-        kfree(mem->info.nodeinfo[node]);
+        kfree(memcg->info.nodeinfo[node]);
 }
 
 static struct mem_cgroup *mem_cgroup_alloc(void)
@@ -4795,51 +4802,51 @@ out_free:
  * Removal of cgroup itself succeeds regardless of refs from swap.
  */
 
-static void __mem_cgroup_free(struct mem_cgroup *mem)
+static void __mem_cgroup_free(struct mem_cgroup *memcg)
 {
         int node;
 
-        mem_cgroup_remove_from_trees(mem);
-        free_css_id(&mem_cgroup_subsys, &mem->css);
+        mem_cgroup_remove_from_trees(memcg);
+        free_css_id(&mem_cgroup_subsys, &memcg->css);
 
         for_each_node_state(node, N_POSSIBLE)
-                free_mem_cgroup_per_zone_info(mem, node);
+                free_mem_cgroup_per_zone_info(memcg, node);
 
-        free_percpu(mem->stat);
+        free_percpu(memcg->stat);
         if (sizeof(struct mem_cgroup) < PAGE_SIZE)
-                kfree(mem);
+                kfree(memcg);
         else
-                vfree(mem);
+                vfree(memcg);
 }
 
-static void mem_cgroup_get(struct mem_cgroup *mem)
+static void mem_cgroup_get(struct mem_cgroup *memcg)
 {
-        atomic_inc(&mem->refcnt);
+        atomic_inc(&memcg->refcnt);
 }
 
-static void __mem_cgroup_put(struct mem_cgroup *mem, int count)
+static void __mem_cgroup_put(struct mem_cgroup *memcg, int count)
 {
-        if (atomic_sub_and_test(count, &mem->refcnt)) {
-                struct mem_cgroup *parent = parent_mem_cgroup(mem);
-                __mem_cgroup_free(mem);
+        if (atomic_sub_and_test(count, &memcg->refcnt)) {
+                struct mem_cgroup *parent = parent_mem_cgroup(memcg);
+                __mem_cgroup_free(memcg);
                 if (parent)
                         mem_cgroup_put(parent);
         }
 }
 
-static void mem_cgroup_put(struct mem_cgroup *mem)
+static void mem_cgroup_put(struct mem_cgroup *memcg)
 {
-        __mem_cgroup_put(mem, 1);
+        __mem_cgroup_put(memcg, 1);
 }
 
 /*
  * Returns the parent mem_cgroup in memcgroup hierarchy with hierarchy enabled.
  */
-static struct mem_cgroup *parent_mem_cgroup(struct mem_cgroup *mem)
+static struct mem_cgroup *parent_mem_cgroup(struct mem_cgroup *memcg)
 {
-        if (!mem->res.parent)
+        if (!memcg->res.parent)
                 return NULL;
-        return mem_cgroup_from_res_counter(mem->res.parent, res);
+        return mem_cgroup_from_res_counter(memcg->res.parent, res);
 }
 
 #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP
@@ -4882,16 +4889,16 @@ static int mem_cgroup_soft_limit_tree_init(void)
 static struct cgroup_subsys_state * __ref
 mem_cgroup_create(struct cgroup_subsys *ss, struct cgroup *cont)
 {
-        struct mem_cgroup *mem, *parent;
+        struct mem_cgroup *memcg, *parent;
         long error = -ENOMEM;
         int node;
 
-        mem = mem_cgroup_alloc();
-        if (!mem)
+        memcg = mem_cgroup_alloc();
+        if (!memcg)
                 return ERR_PTR(error);
 
         for_each_node_state(node, N_POSSIBLE)
-                if (alloc_mem_cgroup_per_zone_info(mem, node))
+                if (alloc_mem_cgroup_per_zone_info(memcg, node))
                         goto free_out;
 
         /* root ? */
@@ -4899,7 +4906,7 @@ mem_cgroup_create(struct cgroup_subsys *ss, struct cgroup *cont)
                 int cpu;
                 enable_swap_cgroup();
                 parent = NULL;
-                root_mem_cgroup = mem;
+                root_mem_cgroup = memcg;
                 if (mem_cgroup_soft_limit_tree_init())
                         goto free_out;
                 for_each_possible_cpu(cpu) {
@@ -4910,13 +4917,13 @@ mem_cgroup_create(struct cgroup_subsys *ss, struct cgroup *cont)
                 hotcpu_notifier(memcg_cpu_hotplug_callback, 0);
         } else {
                 parent = mem_cgroup_from_cont(cont->parent);
-                mem->use_hierarchy = parent->use_hierarchy;
-                mem->oom_kill_disable = parent->oom_kill_disable;
+                memcg->use_hierarchy = parent->use_hierarchy;
+                memcg->oom_kill_disable = parent->oom_kill_disable;
         }
 
         if (parent && parent->use_hierarchy) {
-                res_counter_init(&mem->res, &parent->res);
-                res_counter_init(&mem->memsw, &parent->memsw);
+                res_counter_init(&memcg->res, &parent->res);
+                res_counter_init(&memcg->memsw, &parent->memsw);
                 /*
                  * We increment refcnt of the parent to ensure that we can
                  * safely access it on res_counter_charge/uncharge.
@@ -4925,21 +4932,21 @@ mem_cgroup_create(struct cgroup_subsys *ss, struct cgroup *cont)
                  */
                 mem_cgroup_get(parent);
         } else {
-                res_counter_init(&mem->res, NULL);
-                res_counter_init(&mem->memsw, NULL);
+                res_counter_init(&memcg->res, NULL);
+                res_counter_init(&memcg->memsw, NULL);
         }
-        mem->last_scanned_child = 0;
-        mem->last_scanned_node = MAX_NUMNODES;
-        INIT_LIST_HEAD(&mem->oom_notify);
+        memcg->last_scanned_child = 0;
+        memcg->last_scanned_node = MAX_NUMNODES;
+        INIT_LIST_HEAD(&memcg->oom_notify);
 
         if (parent)
-                mem->swappiness = mem_cgroup_swappiness(parent);
-        atomic_set(&mem->refcnt, 1);
-        mem->move_charge_at_immigrate = 0;
-        mutex_init(&mem->thresholds_lock);
-        return &mem->css;
+                memcg->swappiness = mem_cgroup_swappiness(parent);
+        atomic_set(&memcg->refcnt, 1);
+        memcg->move_charge_at_immigrate = 0;
+        mutex_init(&memcg->thresholds_lock);
+        return &memcg->css;
 free_out:
-        __mem_cgroup_free(mem);
+        __mem_cgroup_free(memcg);
         root_mem_cgroup = NULL;
         return ERR_PTR(error);
 }
@@ -4947,17 +4954,17 @@ free_out:
 static int mem_cgroup_pre_destroy(struct cgroup_subsys *ss,
                                         struct cgroup *cont)
 {
-        struct mem_cgroup *mem = mem_cgroup_from_cont(cont);
+        struct mem_cgroup *memcg = mem_cgroup_from_cont(cont);
 
-        return mem_cgroup_force_empty(mem, false);
+        return mem_cgroup_force_empty(memcg, false);
 }
 
 static void mem_cgroup_destroy(struct cgroup_subsys *ss,
                                 struct cgroup *cont)
 {
-        struct mem_cgroup *mem = mem_cgroup_from_cont(cont);
+        struct mem_cgroup *memcg = mem_cgroup_from_cont(cont);
 
-        mem_cgroup_put(mem);
+        mem_cgroup_put(memcg);
 }
 
 static int mem_cgroup_populate(struct cgroup_subsys *ss,
@@ -4980,9 +4987,9 @@ static int mem_cgroup_do_precharge(unsigned long count)
 {
         int ret = 0;
         int batch_count = PRECHARGE_COUNT_AT_ONCE;
-        struct mem_cgroup *mem = mc.to;
+        struct mem_cgroup *memcg = mc.to;
 
-        if (mem_cgroup_is_root(mem)) {
+        if (mem_cgroup_is_root(memcg)) {
                 mc.precharge += count;
                 /* we don't need css_get for root */
                 return ret;
@@ -4991,16 +4998,16 @@ static int mem_cgroup_do_precharge(unsigned long count)
         if (count > 1) {
                 struct res_counter *dummy;
                 /*
-                 * "mem" cannot be under rmdir() because we've already checked
+                 * "memcg" cannot be under rmdir() because we've already checked
                  * by cgroup_lock_live_cgroup() that it is not removed and we
                  * are still under the same cgroup_mutex. So we can postpone
                  * css_get().
                  */
-                if (res_counter_charge(&mem->res, PAGE_SIZE * count, &dummy))
+                if (res_counter_charge(&memcg->res, PAGE_SIZE * count, &dummy))
                         goto one_by_one;
-                if (do_swap_account && res_counter_charge(&mem->memsw,
+                if (do_swap_account && res_counter_charge(&memcg->memsw,
                                                 PAGE_SIZE * count, &dummy)) {
-                        res_counter_uncharge(&mem->res, PAGE_SIZE * count);
+                        res_counter_uncharge(&memcg->res, PAGE_SIZE * count);
                         goto one_by_one;
                 }
                 mc.precharge += count;
@@ -5017,8 +5024,9 @@ one_by_one:
                         batch_count = PRECHARGE_COUNT_AT_ONCE;
                         cond_resched();
                 }
-                ret = __mem_cgroup_try_charge(NULL, GFP_KERNEL, 1, &mem, false);
-                if (ret || !mem)
+                ret = __mem_cgroup_try_charge(NULL,
+                                        GFP_KERNEL, 1, &memcg, false);
+                if (ret || !memcg)
                         /* mem_cgroup_clear_mc() will do uncharge later */
                         return -ENOMEM;
                 mc.precharge++;
@@ -5292,13 +5300,13 @@ static int mem_cgroup_can_attach(struct cgroup_subsys *ss,
                                 struct task_struct *p)
 {
         int ret = 0;
-        struct mem_cgroup *mem = mem_cgroup_from_cont(cgroup);
+        struct mem_cgroup *memcg = mem_cgroup_from_cont(cgroup);
 
-        if (mem->move_charge_at_immigrate) {
+        if (memcg->move_charge_at_immigrate) {
                 struct mm_struct *mm;
                 struct mem_cgroup *from = mem_cgroup_from_task(p);
 
-                VM_BUG_ON(from == mem);
+                VM_BUG_ON(from == memcg);
 
                 mm = get_task_mm(p);
                 if (!mm)
@@ -5313,7 +5321,7 @@ static int mem_cgroup_can_attach(struct cgroup_subsys *ss,
                         mem_cgroup_start_move(from);
                         spin_lock(&mc.lock);
                         mc.from = from;
-                        mc.to = mem;
+                        mc.to = memcg;
                         spin_unlock(&mc.lock);
                         /* We set mc.moving_task later */