1 files changed, 362 insertions, 38 deletions

diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 59dd8c116372..2efcf38f3b73 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -27,6 +27,7 @@
 #include <linux/backing-dev.h>
 #include <linux/bit_spinlock.h>
 #include <linux/rcupdate.h>
+#include <linux/mutex.h>
 #include <linux/slab.h>
 #include <linux/swap.h>
 #include <linux/spinlock.h>
@@ -132,12 +133,18 @@ struct mem_cgroup {
          */
         struct res_counter res;
         /*
+         * the counter to account for mem+swap usage.
+         */
+        struct res_counter memsw;
+        /*
          * Per cgroup active and inactive list, similar to the
          * per zone LRU lists.
          */
         struct mem_cgroup_lru_info info;
 
         int     prev_priority;  /* for recording reclaim priority */
+        int             obsolete;
+        atomic_t        refcnt;
         /*
          * statistics. This must be placed at the end of memcg.
          */
@@ -167,6 +174,17 @@ pcg_default_flags[NR_CHARGE_TYPE] = {
         0, /* FORCE */
 };
 
+
+/* for encoding cft->private value on file */
+#define _MEM                    (0)
+#define _MEMSWAP                (1)
+#define MEMFILE_PRIVATE(x, val) (((x) << 16) | (val))
+#define MEMFILE_TYPE(val)       (((val) >> 16) & 0xffff)
+#define MEMFILE_ATTR(val)       ((val) & 0xffff)
+
+static void mem_cgroup_get(struct mem_cgroup *mem);
+static void mem_cgroup_put(struct mem_cgroup *mem);
+
 /*
  * Always modified under lru lock. Then, not necessary to preempt_disable()
  */
@@ -485,7 +503,8 @@ unsigned long mem_cgroup_isolate_pages(unsigned long nr_to_scan,
  * oom-killer can be invoked.
  */
 static int __mem_cgroup_try_charge(struct mm_struct *mm,
-                        gfp_t gfp_mask, struct mem_cgroup **memcg, bool oom)
+                        gfp_t gfp_mask, struct mem_cgroup **memcg,
+                        bool oom)
 {
         struct mem_cgroup *mem;
         int nr_retries = MEM_CGROUP_RECLAIM_RETRIES;
@@ -513,12 +532,25 @@ static int __mem_cgroup_try_charge(struct mm_struct *mm,
                 css_get(&mem->css);
         }
 
+        while (1) {
+                int ret;
+                bool noswap = false;
 
-        while (unlikely(res_counter_charge(&mem->res, PAGE_SIZE))) {
+                ret = res_counter_charge(&mem->res, PAGE_SIZE);
+                if (likely(!ret)) {
+                        if (!do_swap_account)
+                                break;
+                        ret = res_counter_charge(&mem->memsw, PAGE_SIZE);
+                        if (likely(!ret))
+                                break;
+                        /* mem+swap counter fails */
+                        res_counter_uncharge(&mem->res, PAGE_SIZE);
+                        noswap = true;
+                }
                 if (!(gfp_mask & __GFP_WAIT))
                         goto nomem;
 
-                if (try_to_free_mem_cgroup_pages(mem, gfp_mask))
+                if (try_to_free_mem_cgroup_pages(mem, gfp_mask, noswap))
                         continue;
 
                 /*
@@ -527,8 +559,13 @@ static int __mem_cgroup_try_charge(struct mm_struct *mm,
                  * moved to swap cache or just unmapped from the cgroup.
                  * Check the limit again to see if the reclaim reduced the
                  * current usage of the cgroup before giving up
+                 *
                  */
-                if (res_counter_check_under_limit(&mem->res))
+                if (!do_swap_account &&
+                        res_counter_check_under_limit(&mem->res))
+                        continue;
+                if (do_swap_account &&
+                        res_counter_check_under_limit(&mem->memsw))
                         continue;
 
                 if (!nr_retries--) {
@@ -582,6 +619,8 @@ static void __mem_cgroup_commit_charge(struct mem_cgroup *mem,
         if (unlikely(PageCgroupUsed(pc))) {
                 unlock_page_cgroup(pc);
                 res_counter_uncharge(&mem->res, PAGE_SIZE);
+                if (do_swap_account)
+                        res_counter_uncharge(&mem->memsw, PAGE_SIZE);
                 css_put(&mem->css);
                 return;
         }
@@ -646,6 +685,8 @@ static int mem_cgroup_move_account(struct page_cgroup *pc,
                 __mem_cgroup_remove_list(from_mz, pc);
                 css_put(&from->css);
                 res_counter_uncharge(&from->res, PAGE_SIZE);
+                if (do_swap_account)
+                        res_counter_uncharge(&from->memsw, PAGE_SIZE);
                 pc->mem_cgroup = to;
                 css_get(&to->css);
                 __mem_cgroup_add_list(to_mz, pc, false);
@@ -692,8 +733,11 @@ static int mem_cgroup_move_parent(struct page_cgroup *pc,
         /* drop extra refcnt */
         css_put(&parent->css);
         /* uncharge if move fails */
-        if (ret)
+        if (ret) {
                 res_counter_uncharge(&parent->res, PAGE_SIZE);
+                if (do_swap_account)
+                        res_counter_uncharge(&parent->memsw, PAGE_SIZE);
+        }
 
         return ret;
 }
@@ -791,7 +835,42 @@ int mem_cgroup_cache_charge(struct page *page, struct mm_struct *mm,
                                 MEM_CGROUP_CHARGE_TYPE_SHMEM, NULL);
 }
 
+int mem_cgroup_try_charge_swapin(struct mm_struct *mm,
+                                 struct page *page,
+                                 gfp_t mask, struct mem_cgroup **ptr)
+{
+        struct mem_cgroup *mem;
+        swp_entry_t     ent;
+
+        if (mem_cgroup_subsys.disabled)
+                return 0;
+
+        if (!do_swap_account)
+                goto charge_cur_mm;
+
+        /*
+         * A racing thread's fault, or swapoff, may have already updated
+         * the pte, and even removed page from swap cache: return success
+         * to go on to do_swap_page()'s pte_same() test, which should fail.
+         */
+        if (!PageSwapCache(page))
+                return 0;
+
+        ent.val = page_private(page);
+
+        mem = lookup_swap_cgroup(ent);
+        if (!mem || mem->obsolete)
+                goto charge_cur_mm;
+        *ptr = mem;
+        return __mem_cgroup_try_charge(NULL, mask, ptr, true);
+charge_cur_mm:
+        if (unlikely(!mm))
+                mm = &init_mm;
+        return __mem_cgroup_try_charge(mm, mask, ptr, true);
+}
+
 #ifdef CONFIG_SWAP
+
 int mem_cgroup_cache_charge_swapin(struct page *page,
                         struct mm_struct *mm, gfp_t mask, bool locked)
 {
@@ -808,8 +887,28 @@ int mem_cgroup_cache_charge_swapin(struct page *page,
          * we reach here.
          */
         if (PageSwapCache(page)) {
+                struct mem_cgroup *mem = NULL;
+                swp_entry_t ent;
+
+                ent.val = page_private(page);
+                if (do_swap_account) {
+                        mem = lookup_swap_cgroup(ent);
+                        if (mem && mem->obsolete)
+                                mem = NULL;
+                        if (mem)
+                                mm = NULL;
+                }
                 ret = mem_cgroup_charge_common(page, mm, mask,
-                                MEM_CGROUP_CHARGE_TYPE_SHMEM, NULL);
+                                MEM_CGROUP_CHARGE_TYPE_SHMEM, mem);
+
+                if (!ret && do_swap_account) {
+                        /* avoid double counting */
+                        mem = swap_cgroup_record(ent, NULL);
+                        if (mem) {
+                                res_counter_uncharge(&mem->memsw, PAGE_SIZE);
+                                mem_cgroup_put(mem);
+                        }
+                }
         }
         if (!locked)
                 unlock_page(page);
@@ -828,6 +927,23 @@ void mem_cgroup_commit_charge_swapin(struct page *page, struct mem_cgroup *ptr)
                 return;
         pc = lookup_page_cgroup(page);
         __mem_cgroup_commit_charge(ptr, pc, MEM_CGROUP_CHARGE_TYPE_MAPPED);
+        /*
+         * Now swap is on-memory. This means this page may be
+         * counted both as mem and swap....double count.
+         * Fix it by uncharging from memsw. This SwapCache is stable
+         * because we're still under lock_page().
+         */
+        if (do_swap_account) {
+                swp_entry_t ent = {.val = page_private(page)};
+                struct mem_cgroup *memcg;
+                memcg = swap_cgroup_record(ent, NULL);
+                if (memcg) {
+                        /* If memcg is obsolete, memcg can be != ptr */
+                        res_counter_uncharge(&memcg->memsw, PAGE_SIZE);
+                        mem_cgroup_put(memcg);
+                }
+
+        }
 }
 
 void mem_cgroup_cancel_charge_swapin(struct mem_cgroup *mem)
@@ -837,6 +953,8 @@ void mem_cgroup_cancel_charge_swapin(struct mem_cgroup *mem)
         if (!mem)
                 return;
         res_counter_uncharge(&mem->res, PAGE_SIZE);
+        if (do_swap_account)
+                res_counter_uncharge(&mem->memsw, PAGE_SIZE);
         css_put(&mem->css);
 }
 
@@ -844,29 +962,31 @@ void mem_cgroup_cancel_charge_swapin(struct mem_cgroup *mem)
 /*
  * uncharge if !page_mapped(page)
  */
-static void
+static struct mem_cgroup *
 __mem_cgroup_uncharge_common(struct page *page, enum charge_type ctype)
 {
         struct page_cgroup *pc;
-        struct mem_cgroup *mem;
+        struct mem_cgroup *mem = NULL;
         struct mem_cgroup_per_zone *mz;
         unsigned long flags;
 
         if (mem_cgroup_subsys.disabled)
-                return;
+                return NULL;
 
         if (PageSwapCache(page))
-                return;
+                return NULL;
 
         /*
          * Check if our page_cgroup is valid
          */
         pc = lookup_page_cgroup(page);
         if (unlikely(!pc || !PageCgroupUsed(pc)))
-                return;
+                return NULL;
 
         lock_page_cgroup(pc);
 
+        mem = pc->mem_cgroup;
+
         if (!PageCgroupUsed(pc))
                 goto unlock_out;
 
@@ -886,8 +1006,11 @@ __mem_cgroup_uncharge_common(struct page *page, enum charge_type ctype)
                 break;
         }
 
+        res_counter_uncharge(&mem->res, PAGE_SIZE);
+        if (do_swap_account && (ctype != MEM_CGROUP_CHARGE_TYPE_SWAPOUT))
+                res_counter_uncharge(&mem->memsw, PAGE_SIZE);
+
         ClearPageCgroupUsed(pc);
-        mem = pc->mem_cgroup;
 
         mz = page_cgroup_zoneinfo(pc);
         spin_lock_irqsave(&mz->lru_lock, flags);
@@ -895,14 +1018,13 @@ __mem_cgroup_uncharge_common(struct page *page, enum charge_type ctype)
         spin_unlock_irqrestore(&mz->lru_lock, flags);
         unlock_page_cgroup(pc);
 
-        res_counter_uncharge(&mem->res, PAGE_SIZE);
         css_put(&mem->css);
 
-        return;
+        return mem;
 
 unlock_out:
         unlock_page_cgroup(pc);
-        return;
+        return NULL;
 }
 
 void mem_cgroup_uncharge_page(struct page *page)
@@ -922,10 +1044,42 @@ void mem_cgroup_uncharge_cache_page(struct page *page)
         __mem_cgroup_uncharge_common(page, MEM_CGROUP_CHARGE_TYPE_CACHE);
 }
 
-void mem_cgroup_uncharge_swapcache(struct page *page)
+/*
+ * called from __delete_from_swap_cache() and drop "page" account.
+ * memcg information is recorded to swap_cgroup of "ent"
+ */
+void mem_cgroup_uncharge_swapcache(struct page *page, swp_entry_t ent)
+{
+        struct mem_cgroup *memcg;
+
+        memcg = __mem_cgroup_uncharge_common(page,
+                                        MEM_CGROUP_CHARGE_TYPE_SWAPOUT);
+        /* record memcg information */
+        if (do_swap_account && memcg) {
+                swap_cgroup_record(ent, memcg);
+                mem_cgroup_get(memcg);
+        }
+}
+
+#ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP
+/*
+ * called from swap_entry_free(). remove record in swap_cgroup and
+ * uncharge "memsw" account.
+ */
+void mem_cgroup_uncharge_swap(swp_entry_t ent)
 {
-        __mem_cgroup_uncharge_common(page, MEM_CGROUP_CHARGE_TYPE_SWAPOUT);
+        struct mem_cgroup *memcg;
+
+        if (!do_swap_account)
+                return;
+
+        memcg = swap_cgroup_record(ent, NULL);
+        if (memcg) {
+                res_counter_uncharge(&memcg->memsw, PAGE_SIZE);
+                mem_cgroup_put(memcg);
+        }
 }
+#endif
 
 /*
  * Before starting migration, account PAGE_SIZE to mem_cgroup that the old
@@ -1034,7 +1188,7 @@ int mem_cgroup_shrink_usage(struct mm_struct *mm, gfp_t gfp_mask)
         rcu_read_unlock();
 
         do {
-                progress = try_to_free_mem_cgroup_pages(mem, gfp_mask);
+                progress = try_to_free_mem_cgroup_pages(mem, gfp_mask, true);
                 progress += res_counter_check_under_limit(&mem->res);
         } while (!progress && --retry);
 
@@ -1044,26 +1198,84 @@ int mem_cgroup_shrink_usage(struct mm_struct *mm, gfp_t gfp_mask)
         return 0;
 }
 
+static DEFINE_MUTEX(set_limit_mutex);
+
 static int mem_cgroup_resize_limit(struct mem_cgroup *memcg,
-                                   unsigned long long val)
+                                unsigned long long val)
 {
 
         int retry_count = MEM_CGROUP_RECLAIM_RETRIES;
         int progress;
+        u64 memswlimit;
         int ret = 0;
 
-        while (res_counter_set_limit(&memcg->res, val)) {
+        while (retry_count) {
                 if (signal_pending(current)) {
                         ret = -EINTR;
                         break;
                 }
-                if (!retry_count) {
-                        ret = -EBUSY;
+                /*
+                 * 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.
+                 */
+                mutex_lock(&set_limit_mutex);
+                memswlimit = res_counter_read_u64(&memcg->memsw, RES_LIMIT);
+                if (memswlimit < val) {
+                        ret = -EINVAL;
+                        mutex_unlock(&set_limit_mutex);
                         break;
                 }
+                ret = res_counter_set_limit(&memcg->res, val);
+                mutex_unlock(&set_limit_mutex);
+
+                if (!ret)
+                        break;
+
                 progress = try_to_free_mem_cgroup_pages(memcg,
-                                GFP_HIGHUSER_MOVABLE);
-                if (!progress)
+                                GFP_HIGHUSER_MOVABLE, false);
+                if (!progress)                  retry_count--;
+        }
+        return ret;
+}
+
+int mem_cgroup_resize_memsw_limit(struct mem_cgroup *memcg,
+                                unsigned long long val)
+{
+        int retry_count = MEM_CGROUP_RECLAIM_RETRIES;
+        u64 memlimit, oldusage, curusage;
+        int ret;
+
+        if (!do_swap_account)
+                return -EINVAL;
+
+        while (retry_count) {
+                if (signal_pending(current)) {
+                        ret = -EINTR;
+                        break;
+                }
+                /*
+                 * 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.
+                 */
+                mutex_lock(&set_limit_mutex);
+                memlimit = res_counter_read_u64(&memcg->res, RES_LIMIT);
+                if (memlimit > val) {
+                        ret = -EINVAL;
+                        mutex_unlock(&set_limit_mutex);
+                        break;
+                }
+                ret = res_counter_set_limit(&memcg->memsw, val);
+                mutex_unlock(&set_limit_mutex);
+
+                if (!ret)
+                        break;
+
+                oldusage = res_counter_read_u64(&memcg->memsw, RES_USAGE);
+                try_to_free_mem_cgroup_pages(memcg, GFP_HIGHUSER_MOVABLE, true);
+                curusage = res_counter_read_u64(&memcg->memsw, RES_USAGE);
+                if (curusage >= oldusage)
                         retry_count--;
         }
         return ret;
@@ -1193,7 +1405,7 @@ try_to_free:
                         goto out;
                 }
                 progress = try_to_free_mem_cgroup_pages(mem,
-                                                  GFP_HIGHUSER_MOVABLE);
+                                                  GFP_HIGHUSER_MOVABLE, false);
                 if (!progress) {
                         nr_retries--;
                         /* maybe some writeback is necessary */
@@ -1216,8 +1428,25 @@ int mem_cgroup_force_empty_write(struct cgroup *cont, unsigned int event)
 
 static u64 mem_cgroup_read(struct cgroup *cont, struct cftype *cft)
 {
-        return res_counter_read_u64(&mem_cgroup_from_cont(cont)->res,
-                                    cft->private);
+        struct mem_cgroup *mem = mem_cgroup_from_cont(cont);
+        u64 val = 0;
+        int type, name;
+
+        type = MEMFILE_TYPE(cft->private);
+        name = MEMFILE_ATTR(cft->private);
+        switch (type) {
+        case _MEM:
+                val = res_counter_read_u64(&mem->res, name);
+                break;
+        case _MEMSWAP:
+                if (do_swap_account)
+                        val = res_counter_read_u64(&mem->memsw, name);
+                break;
+        default:
+                BUG();
+                break;
+        }
+        return val;
 }
 /*
  * The user of this function is...
@@ -1227,15 +1456,22 @@ static int mem_cgroup_write(struct cgroup *cont, struct cftype *cft,
                             const char *buffer)
 {
         struct mem_cgroup *memcg = mem_cgroup_from_cont(cont);
+        int type, name;
         unsigned long long val;
         int ret;
 
-        switch (cft->private) {
+        type = MEMFILE_TYPE(cft->private);
+        name = MEMFILE_ATTR(cft->private);
+        switch (name) {
         case RES_LIMIT:
                 /* This function does all necessary parse...reuse it */
                 ret = res_counter_memparse_write_strategy(buffer, &val);
-                if (!ret)
+                if (ret)
+                        break;
+                if (type == _MEM)
                         ret = mem_cgroup_resize_limit(memcg, val);
+                else
+                        ret = mem_cgroup_resize_memsw_limit(memcg, val);
                 break;
         default:
                 ret = -EINVAL; /* should be BUG() ? */
@@ -1247,14 +1483,23 @@ static int mem_cgroup_write(struct cgroup *cont, struct cftype *cft,
 static int mem_cgroup_reset(struct cgroup *cont, unsigned int event)
 {
         struct mem_cgroup *mem;
+        int type, name;
 
         mem = mem_cgroup_from_cont(cont);
-        switch (event) {
+        type = MEMFILE_TYPE(event);
+        name = MEMFILE_ATTR(event);
+        switch (name) {
         case RES_MAX_USAGE:
-                res_counter_reset_max(&mem->res);
+                if (type == _MEM)
+                        res_counter_reset_max(&mem->res);
+                else
+                        res_counter_reset_max(&mem->memsw);
                 break;
         case RES_FAILCNT:
-                res_counter_reset_failcnt(&mem->res);
+                if (type == _MEM)
+                        res_counter_reset_failcnt(&mem->res);
+                else
+                        res_counter_reset_failcnt(&mem->memsw);
                 break;
         }
         return 0;
@@ -1315,24 +1560,24 @@ static int mem_control_stat_show(struct cgroup *cont, struct cftype *cft,
 static struct cftype mem_cgroup_files[] = {
         {
                 .name = "usage_in_bytes",
-                .private = RES_USAGE,
+                .private = MEMFILE_PRIVATE(_MEM, RES_USAGE),
                 .read_u64 = mem_cgroup_read,
         },
         {
                 .name = "max_usage_in_bytes",
-                .private = RES_MAX_USAGE,
+                .private = MEMFILE_PRIVATE(_MEM, RES_MAX_USAGE),
                 .trigger = mem_cgroup_reset,
                 .read_u64 = mem_cgroup_read,
         },
         {
                 .name = "limit_in_bytes",
-                .private = RES_LIMIT,
+                .private = MEMFILE_PRIVATE(_MEM, RES_LIMIT),
                 .write_string = mem_cgroup_write,
                 .read_u64 = mem_cgroup_read,
         },
         {
                 .name = "failcnt",
-                .private = RES_FAILCNT,
+                .private = MEMFILE_PRIVATE(_MEM, RES_FAILCNT),
                 .trigger = mem_cgroup_reset,
                 .read_u64 = mem_cgroup_read,
         },
@@ -1346,6 +1591,47 @@ static struct cftype mem_cgroup_files[] = {
         },
 };
 
+#ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP
+static struct cftype memsw_cgroup_files[] = {
+        {
+                .name = "memsw.usage_in_bytes",
+                .private = MEMFILE_PRIVATE(_MEMSWAP, RES_USAGE),
+                .read_u64 = mem_cgroup_read,
+        },
+        {
+                .name = "memsw.max_usage_in_bytes",
+                .private = MEMFILE_PRIVATE(_MEMSWAP, RES_MAX_USAGE),
+                .trigger = mem_cgroup_reset,
+                .read_u64 = mem_cgroup_read,
+        },
+        {
+                .name = "memsw.limit_in_bytes",
+                .private = MEMFILE_PRIVATE(_MEMSWAP, RES_LIMIT),
+                .write_string = mem_cgroup_write,
+                .read_u64 = mem_cgroup_read,
+        },
+        {
+                .name = "memsw.failcnt",
+                .private = MEMFILE_PRIVATE(_MEMSWAP, RES_FAILCNT),
+                .trigger = mem_cgroup_reset,
+                .read_u64 = mem_cgroup_read,
+        },
+};
+
+static int register_memsw_files(struct cgroup *cont, struct cgroup_subsys *ss)
+{
+        if (!do_swap_account)
+                return 0;
+        return cgroup_add_files(cont, ss, memsw_cgroup_files,
+                                ARRAY_SIZE(memsw_cgroup_files));
+};
+#else
+static int register_memsw_files(struct cgroup *cont, struct cgroup_subsys *ss)
+{
+        return 0;
+}
+#endif
+
 static int alloc_mem_cgroup_per_zone_info(struct mem_cgroup *mem, int node)
 {
         struct mem_cgroup_per_node *pn;
@@ -1404,14 +1690,44 @@ static struct mem_cgroup *mem_cgroup_alloc(void)
         return mem;
 }
 
+/*
+ * At destroying mem_cgroup, references from swap_cgroup can remain.
+ * (scanning all at force_empty is too costly...)
+ *
+ * Instead of clearing all references at force_empty, we remember
+ * the number of reference from swap_cgroup and free mem_cgroup when
+ * it goes down to 0.
+ *
+ * When mem_cgroup is destroyed, mem->obsolete will be set to 0 and
+ * entry which points to this memcg will be ignore at swapin.
+ *
+ * Removal of cgroup itself succeeds regardless of refs from swap.
+ */
+
 static void mem_cgroup_free(struct mem_cgroup *mem)
 {
+        if (atomic_read(&mem->refcnt) > 0)
+                return;
         if (mem_cgroup_size() < PAGE_SIZE)
                 kfree(mem);
         else
                 vfree(mem);
 }
 
+static void mem_cgroup_get(struct mem_cgroup *mem)
+{
+        atomic_inc(&mem->refcnt);
+}
+
+static void mem_cgroup_put(struct mem_cgroup *mem)
+{
+        if (atomic_dec_and_test(&mem->refcnt)) {
+                if (!mem->obsolete)
+                        return;
+                mem_cgroup_free(mem);
+        }
+}
+
 
 #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP
 static void __init enable_swap_cgroup(void)
@@ -1436,6 +1752,7 @@ mem_cgroup_create(struct cgroup_subsys *ss, struct cgroup *cont)
                 return ERR_PTR(-ENOMEM);
 
         res_counter_init(&mem->res);
+        res_counter_init(&mem->memsw);
 
         for_each_node_state(node, N_POSSIBLE)
                 if (alloc_mem_cgroup_per_zone_info(mem, node))
@@ -1456,6 +1773,7 @@ static void mem_cgroup_pre_destroy(struct cgroup_subsys *ss,
                                         struct cgroup *cont)
 {
         struct mem_cgroup *mem = mem_cgroup_from_cont(cont);
+        mem->obsolete = 1;
         mem_cgroup_force_empty(mem, false);
 }
 
@@ -1474,8 +1792,14 @@ static void mem_cgroup_destroy(struct cgroup_subsys *ss,
 static int mem_cgroup_populate(struct cgroup_subsys *ss,
                                 struct cgroup *cont)
 {
-        return cgroup_add_files(cont, ss, mem_cgroup_files,
-                                        ARRAY_SIZE(mem_cgroup_files));
+        int ret;
+
+        ret = cgroup_add_files(cont, ss, mem_cgroup_files,
+                                ARRAY_SIZE(mem_cgroup_files));
+
+        if (!ret)
+                ret = register_memsw_files(cont, ss);
+        return ret;
 }
 
 static void mem_cgroup_move_task(struct cgroup_subsys *ss,