1 files changed, 1478 insertions, 369 deletions

diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 866dcc7eeb0c..e2996b80601f 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -21,11 +21,13 @@
 #include <linux/memcontrol.h>
 #include <linux/cgroup.h>
 #include <linux/mm.h>
+#include <linux/pagemap.h>
 #include <linux/smp.h>
 #include <linux/page-flags.h>
 #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>
@@ -34,12 +36,23 @@
 #include <linux/vmalloc.h>
 #include <linux/mm_inline.h>
 #include <linux/page_cgroup.h>
+#include "internal.h"
 
 #include <asm/uaccess.h>
 
 struct cgroup_subsys mem_cgroup_subsys __read_mostly;
 #define MEM_CGROUP_RECLAIM_RETRIES      5
 
+#ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP
+/* Turned on only when memory cgroup is enabled && really_do_swap_account = 0 */
+int do_swap_account __read_mostly;
+static int really_do_swap_account __initdata = 1; /* for remember boot option*/
+#else
+#define do_swap_account         (0)
+#endif
+
+static DEFINE_MUTEX(memcg_tasklist);    /* can be hold under cgroup_mutex */
+
 /*
  * Statistics for memory cgroup.
  */
@@ -60,7 +73,7 @@ struct mem_cgroup_stat_cpu {
 } ____cacheline_aligned_in_smp;
 
 struct mem_cgroup_stat {
-        struct mem_cgroup_stat_cpu cpustat[NR_CPUS];
+        struct mem_cgroup_stat_cpu cpustat[0];
 };
 
 /*
@@ -89,9 +102,10 @@ struct mem_cgroup_per_zone {
         /*
          * spin_lock to protect the per cgroup LRU
          */
-        spinlock_t              lru_lock;
         struct list_head        lists[NR_LRU_LISTS];
         unsigned long           count[NR_LRU_LISTS];
+
+        struct zone_reclaim_stat reclaim_stat;
 };
 /* Macro for accessing counter */
 #define MEM_CGROUP_ZSTAT(mz, idx)       ((mz)->count[(idx)])
@@ -122,44 +136,73 @@ 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;
 
+        /*
+          protect against reclaim related member.
+        */
+        spinlock_t reclaim_param_lock;
+
         int     prev_priority;  /* for recording reclaim priority */
+
+        /*
+         * While reclaiming in a hiearchy, we cache the last child we
+         * reclaimed from. Protected by hierarchy_mutex
+         */
+        struct mem_cgroup *last_scanned_child;
         /*
-         * statistics.
+         * Should the accounting and control be hierarchical, per subtree?
+         */
+        bool use_hierarchy;
+        unsigned long   last_oom_jiffies;
+        atomic_t        refcnt;
+
+        unsigned int    swappiness;
+
+        /*
+         * statistics. This must be placed at the end of memcg.
          */
         struct mem_cgroup_stat stat;
 };
-static struct mem_cgroup init_mem_cgroup;
 
 enum charge_type {
         MEM_CGROUP_CHARGE_TYPE_CACHE = 0,
         MEM_CGROUP_CHARGE_TYPE_MAPPED,
         MEM_CGROUP_CHARGE_TYPE_SHMEM,   /* used by page migration of shmem */
         MEM_CGROUP_CHARGE_TYPE_FORCE,   /* used by force_empty */
+        MEM_CGROUP_CHARGE_TYPE_SWAPOUT, /* for accounting swapcache */
         NR_CHARGE_TYPE,
 };
 
 /* only for here (for easy reading.) */
 #define PCGF_CACHE      (1UL << PCG_CACHE)
 #define PCGF_USED       (1UL << PCG_USED)
-#define PCGF_ACTIVE     (1UL << PCG_ACTIVE)
 #define PCGF_LOCK       (1UL << PCG_LOCK)
-#define PCGF_FILE       (1UL << PCG_FILE)
 static const unsigned long
 pcg_default_flags[NR_CHARGE_TYPE] = {
-        PCGF_CACHE | PCGF_FILE | PCGF_USED | PCGF_LOCK, /* File Cache */
-        PCGF_ACTIVE | PCGF_USED | PCGF_LOCK, /* Anon */
-        PCGF_ACTIVE | PCGF_CACHE | PCGF_USED | PCGF_LOCK, /* Shmem */
+        PCGF_CACHE | PCGF_USED | PCGF_LOCK, /* File Cache */
+        PCGF_USED | PCGF_LOCK, /* Anon */
+        PCGF_CACHE | PCGF_USED | PCGF_LOCK, /* Shmem */
         0, /* FORCE */
 };
 
-/*
- * Always modified under lru lock. Then, not necessary to preempt_disable()
- */
+/* 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);
+
 static void mem_cgroup_charge_statistics(struct mem_cgroup *mem,
                                          struct page_cgroup *pc,
                                          bool charge)
@@ -167,10 +210,9 @@ static void mem_cgroup_charge_statistics(struct mem_cgroup *mem,
         int val = (charge)? 1 : -1;
         struct mem_cgroup_stat *stat = &mem->stat;
         struct mem_cgroup_stat_cpu *cpustat;
+        int cpu = get_cpu();
 
-        VM_BUG_ON(!irqs_disabled());
-
-        cpustat = &stat->cpustat[smp_processor_id()];
+        cpustat = &stat->cpustat[cpu];
         if (PageCgroupCache(pc))
                 __mem_cgroup_stat_add_safe(cpustat, MEM_CGROUP_STAT_CACHE, val);
         else
@@ -182,6 +224,7 @@ static void mem_cgroup_charge_statistics(struct mem_cgroup *mem,
         else
                 __mem_cgroup_stat_add_safe(cpustat,
                                 MEM_CGROUP_STAT_PGPGOUT_COUNT, 1);
+        put_cpu();
 }
 
 static struct mem_cgroup_per_zone *
@@ -197,6 +240,9 @@ page_cgroup_zoneinfo(struct page_cgroup *pc)
         int nid = page_cgroup_nid(pc);
         int zid = page_cgroup_zid(pc);
 
+        if (!mem)
+                return NULL;
+
         return mem_cgroup_zoneinfo(mem, nid, zid);
 }
 
@@ -236,77 +282,152 @@ struct mem_cgroup *mem_cgroup_from_task(struct task_struct *p)
                                 struct mem_cgroup, css);
 }
 
-static void __mem_cgroup_remove_list(struct mem_cgroup_per_zone *mz,
-                        struct page_cgroup *pc)
+static struct mem_cgroup *try_get_mem_cgroup_from_mm(struct mm_struct *mm)
 {
-        int lru = LRU_BASE;
+        struct mem_cgroup *mem = NULL;
+        /*
+         * Because we have no locks, mm->owner's may be being moved to other
+         * cgroup. We use css_tryget() here even if this looks
+         * pessimistic (rather than adding locks here).
+         */
+        rcu_read_lock();
+        do {
+                mem = mem_cgroup_from_task(rcu_dereference(mm->owner));
+                if (unlikely(!mem))
+                        break;
+        } while (!css_tryget(&mem->css));
+        rcu_read_unlock();
+        return mem;
+}
 
-        if (PageCgroupUnevictable(pc))
-                lru = LRU_UNEVICTABLE;
-        else {
-                if (PageCgroupActive(pc))
-                        lru += LRU_ACTIVE;
-                if (PageCgroupFile(pc))
-                        lru += LRU_FILE;
-        }
+static bool mem_cgroup_is_obsolete(struct mem_cgroup *mem)
+{
+        if (!mem)
+                return true;
+        return css_is_removed(&mem->css);
+}
 
-        MEM_CGROUP_ZSTAT(mz, lru) -= 1;
+/*
+ * Following LRU functions are allowed to be used without PCG_LOCK.
+ * Operations are called by routine of global LRU independently from memcg.
+ * What we have to take care of here is validness of pc->mem_cgroup.
+ *
+ * Changes to pc->mem_cgroup happens when
+ * 1. charge
+ * 2. moving account
+ * In typical case, "charge" is done before add-to-lru. Exception is SwapCache.
+ * It is added to LRU before charge.
+ * If PCG_USED bit is not set, page_cgroup is not added to this private LRU.
+ * When moving account, the page is not on LRU. It's isolated.
+ */
 
-        mem_cgroup_charge_statistics(pc->mem_cgroup, pc, false);
-        list_del(&pc->lru);
+void mem_cgroup_del_lru_list(struct page *page, enum lru_list lru)
+{
+        struct page_cgroup *pc;
+        struct mem_cgroup *mem;
+        struct mem_cgroup_per_zone *mz;
+
+        if (mem_cgroup_disabled())
+                return;
+        pc = lookup_page_cgroup(page);
+        /* can happen while we handle swapcache. */
+        if (list_empty(&pc->lru) || !pc->mem_cgroup)
+                return;
+        /*
+         * We don't check PCG_USED bit. It's cleared when the "page" is finally
+         * removed from global LRU.
+         */
+        mz = page_cgroup_zoneinfo(pc);
+        mem = pc->mem_cgroup;
+        MEM_CGROUP_ZSTAT(mz, lru) -= 1;
+        list_del_init(&pc->lru);
+        return;
 }
 
-static void __mem_cgroup_add_list(struct mem_cgroup_per_zone *mz,
-                                struct page_cgroup *pc)
+void mem_cgroup_del_lru(struct page *page)
 {
-        int lru = LRU_BASE;
+        mem_cgroup_del_lru_list(page, page_lru(page));
+}
 
-        if (PageCgroupUnevictable(pc))
-                lru = LRU_UNEVICTABLE;
-        else {
-                if (PageCgroupActive(pc))
-                        lru += LRU_ACTIVE;
-                if (PageCgroupFile(pc))
-                        lru += LRU_FILE;
-        }
+void mem_cgroup_rotate_lru_list(struct page *page, enum lru_list lru)
+{
+        struct mem_cgroup_per_zone *mz;
+        struct page_cgroup *pc;
 
-        MEM_CGROUP_ZSTAT(mz, lru) += 1;
-        list_add(&pc->lru, &mz->lists[lru]);
+        if (mem_cgroup_disabled())
+                return;
 
-        mem_cgroup_charge_statistics(pc->mem_cgroup, pc, true);
+        pc = lookup_page_cgroup(page);
+        smp_rmb();
+        /* unused page is not rotated. */
+        if (!PageCgroupUsed(pc))
+                return;
+        mz = page_cgroup_zoneinfo(pc);
+        list_move(&pc->lru, &mz->lists[lru]);
 }
 
-static void __mem_cgroup_move_lists(struct page_cgroup *pc, enum lru_list lru)
+void mem_cgroup_add_lru_list(struct page *page, enum lru_list lru)
 {
-        struct mem_cgroup_per_zone *mz = page_cgroup_zoneinfo(pc);
-        int active    = PageCgroupActive(pc);
-        int file      = PageCgroupFile(pc);
-        int unevictable = PageCgroupUnevictable(pc);
-        enum lru_list from = unevictable ? LRU_UNEVICTABLE :
-                                (LRU_FILE * !!file + !!active);
+        struct page_cgroup *pc;
+        struct mem_cgroup_per_zone *mz;
 
-        if (lru == from)
+        if (mem_cgroup_disabled())
+                return;
+        pc = lookup_page_cgroup(page);
+        /* barrier to sync with "charge" */
+        smp_rmb();
+        if (!PageCgroupUsed(pc))
                 return;
 
-        MEM_CGROUP_ZSTAT(mz, from) -= 1;
+        mz = page_cgroup_zoneinfo(pc);
+        MEM_CGROUP_ZSTAT(mz, lru) += 1;
+        list_add(&pc->lru, &mz->lists[lru]);
+}
+
+/*
+ * At handling SwapCache, pc->mem_cgroup may be changed while it's linked to
+ * lru because the page may.be reused after it's fully uncharged (because of
+ * SwapCache behavior).To handle that, unlink page_cgroup from LRU when charge
+ * it again. This function is only used to charge SwapCache. It's done under
+ * lock_page and expected that zone->lru_lock is never held.
+ */
+static void mem_cgroup_lru_del_before_commit_swapcache(struct page *page)
+{
+        unsigned long flags;
+        struct zone *zone = page_zone(page);
+        struct page_cgroup *pc = lookup_page_cgroup(page);
+
+        spin_lock_irqsave(&zone->lru_lock, flags);
         /*
-         * However this is done under mz->lru_lock, another flags, which
-         * are not related to LRU, will be modified from out-of-lock.
-         * We have to use atomic set/clear flags.
+         * Forget old LRU when this page_cgroup is *not* used. This Used bit
+         * is guarded by lock_page() because the page is SwapCache.
          */
-        if (is_unevictable_lru(lru)) {
-                ClearPageCgroupActive(pc);
-                SetPageCgroupUnevictable(pc);
-        } else {
-                if (is_active_lru(lru))
-                        SetPageCgroupActive(pc);
-                else
-                        ClearPageCgroupActive(pc);
-                ClearPageCgroupUnevictable(pc);
-        }
+        if (!PageCgroupUsed(pc))
+                mem_cgroup_del_lru_list(page, page_lru(page));
+        spin_unlock_irqrestore(&zone->lru_lock, flags);
+}
 
-        MEM_CGROUP_ZSTAT(mz, lru) += 1;
-        list_move(&pc->lru, &mz->lists[lru]);
+static void mem_cgroup_lru_add_after_commit_swapcache(struct page *page)
+{
+        unsigned long flags;
+        struct zone *zone = page_zone(page);
+        struct page_cgroup *pc = lookup_page_cgroup(page);
+
+        spin_lock_irqsave(&zone->lru_lock, flags);
+        /* link when the page is linked to LRU but page_cgroup isn't */
+        if (PageLRU(page) && list_empty(&pc->lru))
+                mem_cgroup_add_lru_list(page, page_lru(page));
+        spin_unlock_irqrestore(&zone->lru_lock, flags);
+}
+
+
+void mem_cgroup_move_lists(struct page *page,
+                           enum lru_list from, enum lru_list to)
+{
+        if (mem_cgroup_disabled())
+                return;
+        mem_cgroup_del_lru_list(page, from);
+        mem_cgroup_add_lru_list(page, to);
 }
 
 int task_in_mem_cgroup(struct task_struct *task, const struct mem_cgroup *mem)
@@ -320,37 +441,6 @@ int task_in_mem_cgroup(struct task_struct *task, const struct mem_cgroup *mem)
 }
 
 /*
- * This routine assumes that the appropriate zone's lru lock is already held
- */
-void mem_cgroup_move_lists(struct page *page, enum lru_list lru)
-{
-        struct page_cgroup *pc;
-        struct mem_cgroup_per_zone *mz;
-        unsigned long flags;
-
-        if (mem_cgroup_subsys.disabled)
-                return;
-
-        /*
-         * We cannot lock_page_cgroup while holding zone's lru_lock,
-         * because other holders of lock_page_cgroup can be interrupted
-         * with an attempt to rotate_reclaimable_page.  But we cannot
-         * safely get to page_cgroup without it, so just try_lock it:
-         * mem_cgroup_isolate_pages allows for page left on wrong list.
-         */
-        pc = lookup_page_cgroup(page);
-        if (!trylock_page_cgroup(pc))
-                return;
-        if (pc && PageCgroupUsed(pc)) {
-                mz = page_cgroup_zoneinfo(pc);
-                spin_lock_irqsave(&mz->lru_lock, flags);
-                __mem_cgroup_move_lists(pc, lru);
-                spin_unlock_irqrestore(&mz->lru_lock, flags);
-        }
-        unlock_page_cgroup(pc);
-}
-
-/*
  * Calculate mapped_ratio under memory controller. This will be used in
  * vmscan.c for deteremining we have to reclaim mapped pages.
  */
@@ -372,39 +462,108 @@ int mem_cgroup_calc_mapped_ratio(struct mem_cgroup *mem)
  */
 int mem_cgroup_get_reclaim_priority(struct mem_cgroup *mem)
 {
-        return mem->prev_priority;
+        int prev_priority;
+
+        spin_lock(&mem->reclaim_param_lock);
+        prev_priority = mem->prev_priority;
+        spin_unlock(&mem->reclaim_param_lock);
+
+        return prev_priority;
 }
 
 void mem_cgroup_note_reclaim_priority(struct mem_cgroup *mem, int priority)
 {
+        spin_lock(&mem->reclaim_param_lock);
         if (priority < mem->prev_priority)
                 mem->prev_priority = priority;
+        spin_unlock(&mem->reclaim_param_lock);
 }
 
 void mem_cgroup_record_reclaim_priority(struct mem_cgroup *mem, int priority)
 {
+        spin_lock(&mem->reclaim_param_lock);
         mem->prev_priority = priority;
+        spin_unlock(&mem->reclaim_param_lock);
 }
 
-/*
- * Calculate # of pages to be scanned in this priority/zone.
- * See also vmscan.c
- *
- * priority starts from "DEF_PRIORITY" and decremented in each loop.
- * (see include/linux/mmzone.h)
- */
+static int calc_inactive_ratio(struct mem_cgroup *memcg, unsigned long *present_pages)
+{
+        unsigned long active;
+        unsigned long inactive;
+        unsigned long gb;
+        unsigned long inactive_ratio;
+
+        inactive = mem_cgroup_get_all_zonestat(memcg, LRU_INACTIVE_ANON);
+        active = mem_cgroup_get_all_zonestat(memcg, LRU_ACTIVE_ANON);
+
+        gb = (inactive + active) >> (30 - PAGE_SHIFT);
+        if (gb)
+                inactive_ratio = int_sqrt(10 * gb);
+        else
+                inactive_ratio = 1;
+
+        if (present_pages) {
+                present_pages[0] = inactive;
+                present_pages[1] = active;
+        }
+
+        return inactive_ratio;
+}
+
+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;
 
-long mem_cgroup_calc_reclaim(struct mem_cgroup *mem, struct zone *zone,
-                                        int priority, enum lru_list lru)
+        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;
+}
+
+unsigned long mem_cgroup_zone_nr_pages(struct mem_cgroup *memcg,
+                                       struct zone *zone,
+                                       enum lru_list lru)
 {
-        long nr_pages;
         int nid = zone->zone_pgdat->node_id;
         int zid = zone_idx(zone);
-        struct mem_cgroup_per_zone *mz = mem_cgroup_zoneinfo(mem, nid, zid);
+        struct mem_cgroup_per_zone *mz = mem_cgroup_zoneinfo(memcg, nid, zid);
 
-        nr_pages = MEM_CGROUP_ZSTAT(mz, lru);
+        return MEM_CGROUP_ZSTAT(mz, lru);
+}
 
-        return (nr_pages >> priority);
+struct zone_reclaim_stat *mem_cgroup_get_reclaim_stat(struct mem_cgroup *memcg,
+                                                      struct zone *zone)
+{
+        int nid = zone->zone_pgdat->node_id;
+        int zid = zone_idx(zone);
+        struct mem_cgroup_per_zone *mz = mem_cgroup_zoneinfo(memcg, nid, zid);
+
+        return &mz->reclaim_stat;
+}
+
+struct zone_reclaim_stat *
+mem_cgroup_get_reclaim_stat_from_page(struct page *page)
+{
+        struct page_cgroup *pc;
+        struct mem_cgroup_per_zone *mz;
+
+        if (mem_cgroup_disabled())
+                return NULL;
+
+        pc = lookup_page_cgroup(page);
+        mz = page_cgroup_zoneinfo(pc);
+        if (!mz)
+                return NULL;
+
+        return &mz->reclaim_stat;
 }
 
 unsigned long mem_cgroup_isolate_pages(unsigned long nr_to_scan,
@@ -429,95 +588,281 @@ unsigned long mem_cgroup_isolate_pages(unsigned long nr_to_scan,
         mz = mem_cgroup_zoneinfo(mem_cont, nid, zid);
         src = &mz->lists[lru];
 
-        spin_lock(&mz->lru_lock);
         scan = 0;
         list_for_each_entry_safe_reverse(pc, tmp, src, lru) {
                 if (scan >= nr_to_scan)
                         break;
+
+                page = pc->page;
                 if (unlikely(!PageCgroupUsed(pc)))
                         continue;
-                page = pc->page;
-
                 if (unlikely(!PageLRU(page)))
                         continue;
 
-                /*
-                 * TODO: play better with lumpy reclaim, grabbing anything.
-                 */
-                if (PageUnevictable(page) ||
-                    (PageActive(page) && !active) ||
-                    (!PageActive(page) && active)) {
-                        __mem_cgroup_move_lists(pc, page_lru(page));
-                        continue;
-                }
-
                 scan++;
-                list_move(&pc->lru, &pc_list);
-
                 if (__isolate_lru_page(page, mode, file) == 0) {
                         list_move(&page->lru, dst);
                         nr_taken++;
                 }
         }
 
-        list_splice(&pc_list, src);
-        spin_unlock(&mz->lru_lock);
-
         *scanned = scan;
         return nr_taken;
 }
 
+#define mem_cgroup_from_res_counter(counter, member)    \
+        container_of(counter, struct mem_cgroup, member)
+
 /*
- * Charge the memory controller for page usage.
- * Return
- * 0 if the charge was successful
- * < 0 if the cgroup is over its limit
+ * This routine finds the DFS walk successor. This routine should be
+ * called with hierarchy_mutex held
  */
-static int mem_cgroup_charge_common(struct page *page, struct mm_struct *mm,
-                                gfp_t gfp_mask, enum charge_type ctype,
-                                struct mem_cgroup *memcg)
+static struct mem_cgroup *
+mem_cgroup_get_next_node(struct mem_cgroup *curr, struct mem_cgroup *root_mem)
 {
+        struct cgroup *cgroup, *curr_cgroup, *root_cgroup;
+
+        curr_cgroup = curr->css.cgroup;
+        root_cgroup = root_mem->css.cgroup;
+
+        if (!list_empty(&curr_cgroup->children)) {
+                /*
+                 * Walk down to children
+                 */
+                mem_cgroup_put(curr);
+                cgroup = list_entry(curr_cgroup->children.next,
+                                                struct cgroup, sibling);
+                curr = mem_cgroup_from_cont(cgroup);
+                mem_cgroup_get(curr);
+                goto done;
+        }
+
+visit_parent:
+        if (curr_cgroup == root_cgroup) {
+                mem_cgroup_put(curr);
+                curr = root_mem;
+                mem_cgroup_get(curr);
+                goto done;
+        }
+
+        /*
+         * Goto next sibling
+         */
+        if (curr_cgroup->sibling.next != &curr_cgroup->parent->children) {
+                mem_cgroup_put(curr);
+                cgroup = list_entry(curr_cgroup->sibling.next, struct cgroup,
+                                                sibling);
+                curr = mem_cgroup_from_cont(cgroup);
+                mem_cgroup_get(curr);
+                goto done;
+        }
+
+        /*
+         * Go up to next parent and next parent's sibling if need be
+         */
+        curr_cgroup = curr_cgroup->parent;
+        goto visit_parent;
+
+done:
+        root_mem->last_scanned_child = curr;
+        return curr;
+}
+
+/*
+ * Visit the first child (need not be the first child as per the ordering
+ * of the cgroup list, since we track last_scanned_child) of @mem and use
+ * that to reclaim free pages from.
+ */
+static struct mem_cgroup *
+mem_cgroup_get_first_node(struct mem_cgroup *root_mem)
+{
+        struct cgroup *cgroup;
+        struct mem_cgroup *ret;
+        bool obsolete;
+
+        obsolete = mem_cgroup_is_obsolete(root_mem->last_scanned_child);
+
+        /*
+         * Scan all children under the mem_cgroup mem
+         */
+        mutex_lock(&mem_cgroup_subsys.hierarchy_mutex);
+        if (list_empty(&root_mem->css.cgroup->children)) {
+                ret = root_mem;
+                goto done;
+        }
+
+        if (!root_mem->last_scanned_child || obsolete) {
+
+                if (obsolete && root_mem->last_scanned_child)
+                        mem_cgroup_put(root_mem->last_scanned_child);
+
+                cgroup = list_first_entry(&root_mem->css.cgroup->children,
+                                struct cgroup, sibling);
+                ret = mem_cgroup_from_cont(cgroup);
+                mem_cgroup_get(ret);
+        } else
+                ret = mem_cgroup_get_next_node(root_mem->last_scanned_child,
+                                                root_mem);
+
+done:
+        root_mem->last_scanned_child = ret;
+        mutex_unlock(&mem_cgroup_subsys.hierarchy_mutex);
+        return ret;
+}
+
+static bool mem_cgroup_check_under_limit(struct mem_cgroup *mem)
+{
+        if (do_swap_account) {
+                if (res_counter_check_under_limit(&mem->res) &&
+                        res_counter_check_under_limit(&mem->memsw))
+                        return true;
+        } else
+                if (res_counter_check_under_limit(&mem->res))
+                        return true;
+        return false;
+}
+
+static unsigned int get_swappiness(struct mem_cgroup *memcg)
+{
+        struct cgroup *cgrp = memcg->css.cgroup;
+        unsigned int swappiness;
+
+        /* root ? */
+        if (cgrp->parent == NULL)
+                return vm_swappiness;
+
+        spin_lock(&memcg->reclaim_param_lock);
+        swappiness = memcg->swappiness;
+        spin_unlock(&memcg->reclaim_param_lock);
+
+        return swappiness;
+}
+
+/*
+ * Dance down the hierarchy if needed to reclaim memory. We remember the
+ * last child 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.
+ */
+static int mem_cgroup_hierarchical_reclaim(struct mem_cgroup *root_mem,
+                                                gfp_t gfp_mask, bool noswap)
+{
+        struct mem_cgroup *next_mem;
+        int ret = 0;
+
+        /*
+         * Reclaim unconditionally and don't check for return value.
+         * We need to reclaim in the current group and down the tree.
+         * One might think about checking for children before reclaiming,
+         * but there might be left over accounting, even after children
+         * have left.
+         */
+        ret = try_to_free_mem_cgroup_pages(root_mem, gfp_mask, noswap,
+                                           get_swappiness(root_mem));
+        if (mem_cgroup_check_under_limit(root_mem))
+                return 0;
+        if (!root_mem->use_hierarchy)
+                return ret;
+
+        next_mem = mem_cgroup_get_first_node(root_mem);
+
+        while (next_mem != root_mem) {
+                if (mem_cgroup_is_obsolete(next_mem)) {
+                        mem_cgroup_put(next_mem);
+                        next_mem = mem_cgroup_get_first_node(root_mem);
+                        continue;
+                }
+                ret = try_to_free_mem_cgroup_pages(next_mem, gfp_mask, noswap,
+                                                   get_swappiness(next_mem));
+                if (mem_cgroup_check_under_limit(root_mem))
+                        return 0;
+                mutex_lock(&mem_cgroup_subsys.hierarchy_mutex);
+                next_mem = mem_cgroup_get_next_node(next_mem, root_mem);
+                mutex_unlock(&mem_cgroup_subsys.hierarchy_mutex);
+        }
+        return ret;
+}
+
+bool mem_cgroup_oom_called(struct task_struct *task)
+{
+        bool ret = false;
         struct mem_cgroup *mem;
-        struct page_cgroup *pc;
-        unsigned long nr_retries = MEM_CGROUP_RECLAIM_RETRIES;
-        struct mem_cgroup_per_zone *mz;
-        unsigned long flags;
+        struct mm_struct *mm;
 
-        pc = lookup_page_cgroup(page);
-        /* can happen at boot */
-        if (unlikely(!pc))
+        rcu_read_lock();
+        mm = task->mm;
+        if (!mm)
+                mm = &init_mm;
+        mem = mem_cgroup_from_task(rcu_dereference(mm->owner));
+        if (mem && time_before(jiffies, mem->last_oom_jiffies + HZ/10))
+                ret = true;
+        rcu_read_unlock();
+        return ret;
+}
+/*
+ * Unlike exported interface, "oom" parameter is added. if oom==true,
+ * 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)
+{
+        struct mem_cgroup *mem, *mem_over_limit;
+        int nr_retries = MEM_CGROUP_RECLAIM_RETRIES;
+        struct res_counter *fail_res;
+
+        if (unlikely(test_thread_flag(TIF_MEMDIE))) {
+                /* Don't account this! */
+                *memcg = NULL;
                 return 0;
-        prefetchw(pc);
+        }
+
         /*
          * We always charge the cgroup the mm_struct belongs to.
          * The mm_struct's mem_cgroup changes on task migration if the
          * thread group leader migrates. It's possible that mm is not
          * set, if so charge the init_mm (happens for pagecache usage).
          */
-
-        if (likely(!memcg)) {
-                rcu_read_lock();
-                mem = mem_cgroup_from_task(rcu_dereference(mm->owner));
-                if (unlikely(!mem)) {
-                        rcu_read_unlock();
-                        return 0;
-                }
-                /*
-                 * For every charge from the cgroup, increment reference count
-                 */
-                css_get(&mem->css);
-                rcu_read_unlock();
+        mem = *memcg;
+        if (likely(!mem)) {
+                mem = try_get_mem_cgroup_from_mm(mm);
+                *memcg = mem;
         } else {
-                mem = memcg;
-                css_get(&memcg->css);
+                css_get(&mem->css);
         }
+        if (unlikely(!mem))
+                return 0;
+
+        VM_BUG_ON(mem_cgroup_is_obsolete(mem));
+
+        while (1) {
+                int ret;
+                bool noswap = false;
+
+                ret = res_counter_charge(&mem->res, PAGE_SIZE, &fail_res);
+                if (likely(!ret)) {
+                        if (!do_swap_account)
+                                break;
+                        ret = res_counter_charge(&mem->memsw, PAGE_SIZE,
+                                                        &fail_res);
+                        if (likely(!ret))
+                                break;
+                        /* mem+swap counter fails */
+                        res_counter_uncharge(&mem->res, PAGE_SIZE);
+                        noswap = true;
+                        mem_over_limit = mem_cgroup_from_res_counter(fail_res,
+                                                                        memsw);
+                } else
+                        /* mem counter fails */
+                        mem_over_limit = mem_cgroup_from_res_counter(fail_res,
+                                                                        res);
 
-        while (unlikely(res_counter_charge(&mem->res, PAGE_SIZE))) {
                 if (!(gfp_mask & __GFP_WAIT))
-                        goto out;
+                        goto nomem;
 
-                if (try_to_free_mem_cgroup_pages(mem, gfp_mask))
-                        continue;
+                ret = mem_cgroup_hierarchical_reclaim(mem_over_limit, gfp_mask,
+                                                        noswap);
 
                 /*
                  * try_to_free_mem_cgroup_pages() might not give us a full
@@ -525,49 +870,214 @@ static int mem_cgroup_charge_common(struct page *page, 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 (mem_cgroup_check_under_limit(mem_over_limit))
                         continue;
 
                 if (!nr_retries--) {
-                        mem_cgroup_out_of_memory(mem, gfp_mask);
-                        goto out;
+                        if (oom) {
+                                mutex_lock(&memcg_tasklist);
+                                mem_cgroup_out_of_memory(mem_over_limit, gfp_mask);
+                                mutex_unlock(&memcg_tasklist);
+                                mem_over_limit->last_oom_jiffies = jiffies;
+                        }
+                        goto nomem;
                 }
         }
+        return 0;
+nomem:
+        css_put(&mem->css);
+        return -ENOMEM;
+}
 
+static struct mem_cgroup *try_get_mem_cgroup_from_swapcache(struct page *page)
+{
+        struct mem_cgroup *mem;
+        swp_entry_t ent;
+
+        if (!PageSwapCache(page))
+                return NULL;
+
+        ent.val = page_private(page);
+        mem = lookup_swap_cgroup(ent);
+        if (!mem)
+                return NULL;
+        if (!css_tryget(&mem->css))
+                return NULL;
+        return mem;
+}
+
+/*
+ * commit a charge got by __mem_cgroup_try_charge() and makes page_cgroup to be
+ * USED state. If already USED, uncharge and return.
+ */
+
+static void __mem_cgroup_commit_charge(struct mem_cgroup *mem,
+                                     struct page_cgroup *pc,
+                                     enum charge_type ctype)
+{
+        /* try_charge() can return NULL to *memcg, taking care of it. */
+        if (!mem)
+                return;
 
         lock_page_cgroup(pc);
         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);
-
-                goto done;
+                return;
         }
         pc->mem_cgroup = mem;
-        /*
-         * If a page is accounted as a page cache, insert to inactive list.
-         * If anon, insert to active list.
-         */
+        smp_wmb();
         pc->flags = pcg_default_flags[ctype];
 
-        mz = page_cgroup_zoneinfo(pc);
+        mem_cgroup_charge_statistics(mem, pc, true);
 
-        spin_lock_irqsave(&mz->lru_lock, flags);
-        __mem_cgroup_add_list(mz, pc);
-        spin_unlock_irqrestore(&mz->lru_lock, flags);
         unlock_page_cgroup(pc);
+}
 
-done:
-        return 0;
+/**
+ * mem_cgroup_move_account - move account of the page
+ * @pc: page_cgroup of the page.
+ * @from: mem_cgroup which the page is moved from.
+ * @to: mem_cgroup which the page is moved to. @from != @to.
+ *
+ * The caller must confirm following.
+ * - page is not on LRU (isolate_page() is useful.)
+ *
+ * returns 0 at success,
+ * returns -EBUSY when lock is busy or "pc" is unstable.
+ *
+ * This function does "uncharge" from old cgroup but doesn't do "charge" to
+ * new cgroup. It should be done by a caller.
+ */
+
+static int mem_cgroup_move_account(struct page_cgroup *pc,
+        struct mem_cgroup *from, struct mem_cgroup *to)
+{
+        struct mem_cgroup_per_zone *from_mz, *to_mz;
+        int nid, zid;
+        int ret = -EBUSY;
+
+        VM_BUG_ON(from == to);
+        VM_BUG_ON(PageLRU(pc->page));
+
+        nid = page_cgroup_nid(pc);
+        zid = page_cgroup_zid(pc);
+        from_mz =  mem_cgroup_zoneinfo(from, nid, zid);
+        to_mz =  mem_cgroup_zoneinfo(to, nid, zid);
+
+        if (!trylock_page_cgroup(pc))
+                return ret;
+
+        if (!PageCgroupUsed(pc))
+                goto out;
+
+        if (pc->mem_cgroup != from)
+                goto out;
+
+        css_put(&from->css);
+        res_counter_uncharge(&from->res, PAGE_SIZE);
+        mem_cgroup_charge_statistics(from, pc, false);
+        if (do_swap_account)
+                res_counter_uncharge(&from->memsw, PAGE_SIZE);
+        pc->mem_cgroup = to;
+        mem_cgroup_charge_statistics(to, pc, true);
+        css_get(&to->css);
+        ret = 0;
 out:
-        css_put(&mem->css);
-        return -ENOMEM;
+        unlock_page_cgroup(pc);
+        return ret;
+}
+
+/*
+ * move charges to its parent.
+ */
+
+static int mem_cgroup_move_parent(struct page_cgroup *pc,
+                                  struct mem_cgroup *child,
+                                  gfp_t gfp_mask)
+{
+        struct page *page = pc->page;
+        struct cgroup *cg = child->css.cgroup;
+        struct cgroup *pcg = cg->parent;
+        struct mem_cgroup *parent;
+        int ret;
+
+        /* Is ROOT ? */
+        if (!pcg)
+                return -EINVAL;
+
+
+        parent = mem_cgroup_from_cont(pcg);
+
+
+        ret = __mem_cgroup_try_charge(NULL, gfp_mask, &parent, false);
+        if (ret || !parent)
+                return ret;
+
+        if (!get_page_unless_zero(page))
+                return -EBUSY;
+
+        ret = isolate_lru_page(page);
+
+        if (ret)
+                goto cancel;
+
+        ret = mem_cgroup_move_account(pc, child, parent);
+
+        /* drop extra refcnt by try_charge() (move_account increment one) */
+        css_put(&parent->css);
+        putback_lru_page(page);
+        if (!ret) {
+                put_page(page);
+                return 0;
+        }
+        /* uncharge if move fails */
+cancel:
+        res_counter_uncharge(&parent->res, PAGE_SIZE);
+        if (do_swap_account)
+                res_counter_uncharge(&parent->memsw, PAGE_SIZE);
+        put_page(page);
+        return ret;
+}
+
+/*
+ * Charge the memory controller for page usage.
+ * Return
+ * 0 if the charge was successful
+ * < 0 if the cgroup is over its limit
+ */
+static int mem_cgroup_charge_common(struct page *page, struct mm_struct *mm,
+                                gfp_t gfp_mask, enum charge_type ctype,
+                                struct mem_cgroup *memcg)
+{
+        struct mem_cgroup *mem;
+        struct page_cgroup *pc;
+        int ret;
+
+        pc = lookup_page_cgroup(page);
+        /* can happen at boot */
+        if (unlikely(!pc))
+                return 0;
+        prefetchw(pc);
+
+        mem = memcg;
+        ret = __mem_cgroup_try_charge(mm, gfp_mask, &mem, true);
+        if (ret || !mem)
+                return ret;
+
+        __mem_cgroup_commit_charge(mem, pc, ctype);
+        return 0;
 }
 
-int mem_cgroup_charge(struct page *page, struct mm_struct *mm, gfp_t gfp_mask)
+int mem_cgroup_newpage_charge(struct page *page,
+                              struct mm_struct *mm, gfp_t gfp_mask)
 {
-        if (mem_cgroup_subsys.disabled)
+        if (mem_cgroup_disabled())
                 return 0;
         if (PageCompound(page))
                 return 0;
@@ -589,7 +1099,10 @@ int mem_cgroup_charge(struct page *page, struct mm_struct *mm, gfp_t gfp_mask)
 int mem_cgroup_cache_charge(struct page *page, struct mm_struct *mm,
                                 gfp_t gfp_mask)
 {
-        if (mem_cgroup_subsys.disabled)
+        struct mem_cgroup *mem = NULL;
+        int ret;
+
+        if (mem_cgroup_disabled())
                 return 0;
         if (PageCompound(page))
                 return 0;
@@ -601,6 +1114,8 @@ int mem_cgroup_cache_charge(struct page *page, struct mm_struct *mm,
          * For GFP_NOWAIT case, the page may be pre-charged before calling
          * add_to_page_cache(). (See shmem.c) check it here and avoid to call
          * charge twice. (It works but has to pay a bit larger cost.)
+         * And when the page is SwapCache, it should take swap information
+         * into account. This is under lock_page() now.
          */
         if (!(gfp_mask & __GFP_WAIT)) {
                 struct page_cgroup *pc;
@@ -617,58 +1132,198 @@ int mem_cgroup_cache_charge(struct page *page, struct mm_struct *mm,
                 unlock_page_cgroup(pc);
         }
 
-        if (unlikely(!mm))
+        if (do_swap_account && PageSwapCache(page)) {
+                mem = try_get_mem_cgroup_from_swapcache(page);
+                if (mem)
+                        mm = NULL;
+                  else
+                        mem = NULL;
+                /* SwapCache may be still linked to LRU now. */
+                mem_cgroup_lru_del_before_commit_swapcache(page);
+        }
+
+        if (unlikely(!mm && !mem))
                 mm = &init_mm;
 
         if (page_is_file_cache(page))
                 return mem_cgroup_charge_common(page, mm, gfp_mask,
                                 MEM_CGROUP_CHARGE_TYPE_CACHE, NULL);
-        else
-                return mem_cgroup_charge_common(page, mm, gfp_mask,
-                                MEM_CGROUP_CHARGE_TYPE_SHMEM, NULL);
+
+        ret = mem_cgroup_charge_common(page, mm, gfp_mask,
+                                MEM_CGROUP_CHARGE_TYPE_SHMEM, mem);
+        if (mem)
+                css_put(&mem->css);
+        if (PageSwapCache(page))
+                mem_cgroup_lru_add_after_commit_swapcache(page);
+
+        if (do_swap_account && !ret && PageSwapCache(page)) {
+                swp_entry_t ent = {.val = page_private(page)};
+                /* avoid double counting */
+                mem = swap_cgroup_record(ent, NULL);
+                if (mem) {
+                        res_counter_uncharge(&mem->memsw, PAGE_SIZE);
+                        mem_cgroup_put(mem);
+                }
+        }
+        return ret;
+}
+
+/*
+ * While swap-in, try_charge -> commit or cancel, the page is locked.
+ * And when try_charge() successfully returns, one refcnt to memcg without
+ * struct page_cgroup is aquired. This refcnt will be cumsumed by
+ * "commit()" or removed by "cancel()"
+ */
+int mem_cgroup_try_charge_swapin(struct mm_struct *mm,
+                                 struct page *page,
+                                 gfp_t mask, struct mem_cgroup **ptr)
+{
+        struct mem_cgroup *mem;
+        int ret;
+
+        if (mem_cgroup_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;
+        mem = try_get_mem_cgroup_from_swapcache(page);
+        if (!mem)
+                goto charge_cur_mm;
+        *ptr = mem;
+        ret = __mem_cgroup_try_charge(NULL, mask, ptr, true);
+        /* drop extra refcnt from tryget */
+        css_put(&mem->css);
+        return ret;
+charge_cur_mm:
+        if (unlikely(!mm))
+                mm = &init_mm;
+        return __mem_cgroup_try_charge(mm, mask, ptr, true);
+}
+
+void mem_cgroup_commit_charge_swapin(struct page *page, struct mem_cgroup *ptr)
+{
+        struct page_cgroup *pc;
+
+        if (mem_cgroup_disabled())
+                return;
+        if (!ptr)
+                return;
+        pc = lookup_page_cgroup(page);
+        mem_cgroup_lru_del_before_commit_swapcache(page);
+        __mem_cgroup_commit_charge(ptr, pc, MEM_CGROUP_CHARGE_TYPE_MAPPED);
+        mem_cgroup_lru_add_after_commit_swapcache(page);
+        /*
+         * 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. Basically, this SwapCache is stable
+         * under lock_page(). But in do_swap_page()::memory.c, reuse_swap_page()
+         * may call delete_from_swap_cache() before reach here.
+         */
+        if (do_swap_account && PageSwapCache(page)) {
+                swp_entry_t ent = {.val = page_private(page)};
+                struct mem_cgroup *memcg;
+                memcg = swap_cgroup_record(ent, NULL);
+                if (memcg) {
+                        res_counter_uncharge(&memcg->memsw, PAGE_SIZE);
+                        mem_cgroup_put(memcg);
+                }
+
+        }
+        /* add this page(page_cgroup) to the LRU we want. */
+
 }
 
+void mem_cgroup_cancel_charge_swapin(struct mem_cgroup *mem)
+{
+        if (mem_cgroup_disabled())
+                return;
+        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);
+}
+
+
 /*
  * 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;
+        if (mem_cgroup_disabled())
+                return NULL;
+
+        if (PageSwapCache(page))
+                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);
-        if ((ctype == MEM_CGROUP_CHARGE_TYPE_MAPPED && page_mapped(page))
-             || !PageCgroupUsed(pc)) {
-                /* This happens at race in zap_pte_range() and do_swap_page()*/
-                unlock_page_cgroup(pc);
-                return;
+
+        mem = pc->mem_cgroup;
+
+        if (!PageCgroupUsed(pc))
+                goto unlock_out;
+
+        switch (ctype) {
+        case MEM_CGROUP_CHARGE_TYPE_MAPPED:
+                if (page_mapped(page))
+                        goto unlock_out;
+                break;
+        case MEM_CGROUP_CHARGE_TYPE_SWAPOUT:
+                if (!PageAnon(page)) {  /* Shared memory */
+                        if (page->mapping && !page_is_file_cache(page))
+                                goto unlock_out;
+                } else if (page_mapped(page)) /* Anon */
+                                goto unlock_out;
+                break;
+        default:
+                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);
+
+        mem_cgroup_charge_statistics(mem, pc, false);
         ClearPageCgroupUsed(pc);
-        mem = pc->mem_cgroup;
+        /*
+         * pc->mem_cgroup is not cleared here. It will be accessed when it's
+         * freed from LRU. This is safe because uncharged page is expected not
+         * to be reused (freed soon). Exception is SwapCache, it's handled by
+         * special functions.
+         */
 
         mz = page_cgroup_zoneinfo(pc);
-        spin_lock_irqsave(&mz->lru_lock, flags);
-        __mem_cgroup_remove_list(mz, pc);
-        spin_unlock_irqrestore(&mz->lru_lock, flags);
         unlock_page_cgroup(pc);
 
-        res_counter_uncharge(&mem->res, PAGE_SIZE);
-        css_put(&mem->css);
+        /* at swapout, this memcg will be accessed to record to swap */
+        if (ctype != MEM_CGROUP_CHARGE_TYPE_SWAPOUT)
+                css_put(&mem->css);
 
-        return;
+        return mem;
+
+unlock_out:
+        unlock_page_cgroup(pc);
+        return NULL;
 }
 
 void mem_cgroup_uncharge_page(struct page *page)
@@ -689,16 +1344,55 @@ void mem_cgroup_uncharge_cache_page(struct page *page)
 }
 
 /*
- * Before starting migration, account against new 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);
+        }
+        if (memcg)
+                css_put(&memcg->css);
+}
+
+#ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP
+/*
+ * called from swap_entry_free(). remove record in swap_cgroup and
+ * uncharge "memsw" account.
  */
-int mem_cgroup_prepare_migration(struct page *page, struct page *newpage)
+void mem_cgroup_uncharge_swap(swp_entry_t ent)
+{
+        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
+ * page belongs to.
+ */
+int mem_cgroup_prepare_migration(struct page *page, struct mem_cgroup **ptr)
 {
         struct page_cgroup *pc;
         struct mem_cgroup *mem = NULL;
-        enum charge_type ctype = MEM_CGROUP_CHARGE_TYPE_MAPPED;
         int ret = 0;
 
-        if (mem_cgroup_subsys.disabled)
+        if (mem_cgroup_disabled())
                 return 0;
 
         pc = lookup_page_cgroup(page);
@@ -706,41 +1400,67 @@ int mem_cgroup_prepare_migration(struct page *page, struct page *newpage)
         if (PageCgroupUsed(pc)) {
                 mem = pc->mem_cgroup;
                 css_get(&mem->css);
-                if (PageCgroupCache(pc)) {
-                        if (page_is_file_cache(page))
-                                ctype = MEM_CGROUP_CHARGE_TYPE_CACHE;
-                        else
-                                ctype = MEM_CGROUP_CHARGE_TYPE_SHMEM;
-                }
         }
         unlock_page_cgroup(pc);
+
         if (mem) {
-                ret = mem_cgroup_charge_common(newpage, NULL, GFP_KERNEL,
-                        ctype, mem);
+                ret = __mem_cgroup_try_charge(NULL, GFP_KERNEL, &mem, false);
                 css_put(&mem->css);
         }
+        *ptr = mem;
         return ret;
 }
 
 /* remove redundant charge if migration failed*/
-void mem_cgroup_end_migration(struct page *newpage)
+void mem_cgroup_end_migration(struct mem_cgroup *mem,
+                struct page *oldpage, struct page *newpage)
 {
+        struct page *target, *unused;
+        struct page_cgroup *pc;
+        enum charge_type ctype;
+
+        if (!mem)
+                return;
+
+        /* at migration success, oldpage->mapping is NULL. */
+        if (oldpage->mapping) {
+                target = oldpage;
+                unused = NULL;
+        } else {
+                target = newpage;
+                unused = oldpage;
+        }
+
+        if (PageAnon(target))
+                ctype = MEM_CGROUP_CHARGE_TYPE_MAPPED;
+        else if (page_is_file_cache(target))
+                ctype = MEM_CGROUP_CHARGE_TYPE_CACHE;
+        else
+                ctype = MEM_CGROUP_CHARGE_TYPE_SHMEM;
+
+        /* unused page is not on radix-tree now. */
+        if (unused)
+                __mem_cgroup_uncharge_common(unused, ctype);
+
+        pc = lookup_page_cgroup(target);
         /*
-         * At success, page->mapping is not NULL.
-         * special rollback care is necessary when
-         * 1. at migration failure. (newpage->mapping is cleared in this case)
-         * 2. the newpage was moved but not remapped again because the task
-         *    exits and the newpage is obsolete. In this case, the new page
-         *    may be a swapcache. So, we just call mem_cgroup_uncharge_page()
-         *    always for avoiding mess. The  page_cgroup will be removed if
-         *    unnecessary. File cache pages is still on radix-tree. Don't
-         *    care it.
+         * __mem_cgroup_commit_charge() check PCG_USED bit of page_cgroup.
+         * So, double-counting is effectively avoided.
          */
-        if (!newpage->mapping)
-                __mem_cgroup_uncharge_common(newpage,
-                                MEM_CGROUP_CHARGE_TYPE_FORCE);
-        else if (PageAnon(newpage))
-                mem_cgroup_uncharge_page(newpage);
+        __mem_cgroup_commit_charge(mem, pc, ctype);
+
+        /*
+         * Both of oldpage and newpage are still under lock_page().
+         * Then, we don't have to care about race in radix-tree.
+         * But we have to be careful that this page is unmapped or not.
+         *
+         * There is a case for !page_mapped(). At the start of
+         * migration, oldpage was mapped. But now, it's zapped.
+         * But we know *target* page is not freed/reused under us.
+         * mem_cgroup_uncharge_page() does all necessary checks.
+         */
+        if (ctype == MEM_CGROUP_CHARGE_TYPE_MAPPED)
+                mem_cgroup_uncharge_page(target);
 }
 
 /*
@@ -748,29 +1468,26 @@ void mem_cgroup_end_migration(struct page *newpage)
  * This is typically used for page reclaiming for shmem for reducing side
  * effect of page allocation from shmem, which is used by some mem_cgroup.
  */
-int mem_cgroup_shrink_usage(struct mm_struct *mm, gfp_t gfp_mask)
+int mem_cgroup_shrink_usage(struct page *page,
+                            struct mm_struct *mm,
+                            gfp_t gfp_mask)
 {
-        struct mem_cgroup *mem;
+        struct mem_cgroup *mem = NULL;
         int progress = 0;
         int retry = MEM_CGROUP_RECLAIM_RETRIES;
 
-        if (mem_cgroup_subsys.disabled)
+        if (mem_cgroup_disabled())
                 return 0;
-        if (!mm)
+        if (page)
+                mem = try_get_mem_cgroup_from_swapcache(page);
+        if (!mem && mm)
+                mem = try_get_mem_cgroup_from_mm(mm);
+        if (unlikely(!mem))
                 return 0;
 
-        rcu_read_lock();
-        mem = mem_cgroup_from_task(rcu_dereference(mm->owner));
-        if (unlikely(!mem)) {
-                rcu_read_unlock();
-                return 0;
-        }
-        css_get(&mem->css);
-        rcu_read_unlock();
-
         do {
-                progress = try_to_free_mem_cgroup_pages(mem, gfp_mask);
-                progress += res_counter_check_under_limit(&mem->res);
+                progress = mem_cgroup_hierarchical_reclaim(mem, gfp_mask, true);
+                progress += mem_cgroup_check_under_limit(mem);
         } while (!progress && --retry);
 
         css_put(&mem->css);
@@ -779,116 +1496,295 @@ int mem_cgroup_shrink_usage(struct mm_struct *mm, gfp_t gfp_mask)
         return 0;
 }
 
-int mem_cgroup_resize_limit(struct mem_cgroup *memcg, unsigned long long val)
+static DEFINE_MUTEX(set_limit_mutex);
+
+static int mem_cgroup_resize_limit(struct mem_cgroup *memcg,
+                                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;
                 }
-                progress = try_to_free_mem_cgroup_pages(memcg, GFP_KERNEL);
-                if (!progress)
-                        retry_count--;
+                ret = res_counter_set_limit(&memcg->res, val);
+                mutex_unlock(&set_limit_mutex);
+
+                if (!ret)
+                        break;
+
+                progress = mem_cgroup_hierarchical_reclaim(memcg, GFP_KERNEL,
+                                                           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);
+                mem_cgroup_hierarchical_reclaim(memcg, GFP_KERNEL, true);
+                curusage = res_counter_read_u64(&memcg->memsw, RES_USAGE);
+                if (curusage >= oldusage)
+                        retry_count--;
+        }
+        return ret;
+}
 
 /*
  * This routine traverse page_cgroup in given list and drop them all.
  * *And* this routine doesn't reclaim page itself, just removes page_cgroup.
  */
-#define FORCE_UNCHARGE_BATCH    (128)
-static void mem_cgroup_force_empty_list(struct mem_cgroup *mem,
-                            struct mem_cgroup_per_zone *mz,
-                            enum lru_list lru)
+static int mem_cgroup_force_empty_list(struct mem_cgroup *mem,
+                                int node, int zid, enum lru_list lru)
 {
-        struct page_cgroup *pc;
-        struct page *page;
-        int count = FORCE_UNCHARGE_BATCH;
-        unsigned long flags;
+        struct zone *zone;
+        struct mem_cgroup_per_zone *mz;
+        struct page_cgroup *pc, *busy;
+        unsigned long flags, loop;
         struct list_head *list;
+        int ret = 0;
 
+        zone = &NODE_DATA(node)->node_zones[zid];
+        mz = mem_cgroup_zoneinfo(mem, node, zid);
         list = &mz->lists[lru];
 
-        spin_lock_irqsave(&mz->lru_lock, flags);
-        while (!list_empty(list)) {
-                pc = list_entry(list->prev, struct page_cgroup, lru);
-                page = pc->page;
-                if (!PageCgroupUsed(pc))
-                        break;
-                get_page(page);
-                spin_unlock_irqrestore(&mz->lru_lock, flags);
-                /*
-                 * Check if this page is on LRU. !LRU page can be found
-                 * if it's under page migration.
-                 */
-                if (PageLRU(page)) {
-                        __mem_cgroup_uncharge_common(page,
-                                        MEM_CGROUP_CHARGE_TYPE_FORCE);
-                        put_page(page);
-                        if (--count <= 0) {
-                                count = FORCE_UNCHARGE_BATCH;
-                                cond_resched();
-                        }
-                } else {
-                        spin_lock_irqsave(&mz->lru_lock, flags);
+        loop = MEM_CGROUP_ZSTAT(mz, lru);
+        /* give some margin against EBUSY etc...*/
+        loop += 256;
+        busy = NULL;
+        while (loop--) {
+                ret = 0;
+                spin_lock_irqsave(&zone->lru_lock, flags);
+                if (list_empty(list)) {
+                        spin_unlock_irqrestore(&zone->lru_lock, flags);
                         break;
                 }
-                spin_lock_irqsave(&mz->lru_lock, flags);
+                pc = list_entry(list->prev, struct page_cgroup, lru);
+                if (busy == pc) {
+                        list_move(&pc->lru, list);
+                        busy = 0;
+                        spin_unlock_irqrestore(&zone->lru_lock, flags);
+                        continue;
+                }
+                spin_unlock_irqrestore(&zone->lru_lock, flags);
+
+                ret = mem_cgroup_move_parent(pc, mem, GFP_KERNEL);
+                if (ret == -ENOMEM)
+                        break;
+
+                if (ret == -EBUSY || ret == -EINVAL) {
+                        /* found lock contention or "pc" is obsolete. */
+                        busy = pc;
+                        cond_resched();
+                } else
+                        busy = NULL;
         }
-        spin_unlock_irqrestore(&mz->lru_lock, flags);
+
+        if (!ret && !list_empty(list))
+                return -EBUSY;
+        return ret;
 }
 
 /*
  * 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)
+static int mem_cgroup_force_empty(struct mem_cgroup *mem, bool free_all)
 {
-        int ret = -EBUSY;
-        int node, zid;
+        int ret;
+        int node, zid, shrink;
+        int nr_retries = MEM_CGROUP_RECLAIM_RETRIES;
+        struct cgroup *cgrp = mem->css.cgroup;
 
         css_get(&mem->css);
-        /*
-         * page reclaim code (kswapd etc..) will move pages between
-         * active_list <-> inactive_list while we don't take a lock.
-         * So, we have to do loop here until all lists are empty.
-         */
+
+        shrink = 0;
+        /* should free all ? */
+        if (free_all)
+                goto try_to_free;
+move_account:
         while (mem->res.usage > 0) {
-                if (atomic_read(&mem->css.cgroup->count) > 0)
+                ret = -EBUSY;
+                if (cgroup_task_count(cgrp) || !list_empty(&cgrp->children))
+                        goto out;
+                ret = -EINTR;
+                if (signal_pending(current))
                         goto out;
                 /* This is for making all *used* pages to be on LRU. */
                 lru_add_drain_all();
-                for_each_node_state(node, N_POSSIBLE)
-                        for (zid = 0; zid < MAX_NR_ZONES; zid++) {
-                                struct mem_cgroup_per_zone *mz;
+                ret = 0;
+                for_each_node_state(node, N_POSSIBLE) {
+                        for (zid = 0; !ret && zid < MAX_NR_ZONES; zid++) {
                                 enum lru_list l;
-                                mz = mem_cgroup_zoneinfo(mem, node, zid);
-                                for_each_lru(l)
-                                        mem_cgroup_force_empty_list(mem, mz, l);
+                                for_each_lru(l) {
+                                        ret = mem_cgroup_force_empty_list(mem,
+                                                        node, zid, l);
+                                        if (ret)
+                                                break;
+                                }
                         }
+                        if (ret)
+                                break;
+                }
+                /* it seems parent cgroup doesn't have enough mem */
+                if (ret == -ENOMEM)
+                        goto try_to_free;
                 cond_resched();
         }
         ret = 0;
 out:
         css_put(&mem->css);
         return ret;
+
+try_to_free:
+        /* returns EBUSY if there is a task or if we come here twice. */
+        if (cgroup_task_count(cgrp) || !list_empty(&cgrp->children) || shrink) {
+                ret = -EBUSY;
+                goto out;
+        }
+        /* we call try-to-free pages for make this cgroup empty */
+        lru_add_drain_all();
+        /* try to free all pages in this cgroup */
+        shrink = 1;
+        while (nr_retries && mem->res.usage > 0) {
+                int progress;
+
+                if (signal_pending(current)) {
+                        ret = -EINTR;
+                        goto out;
+                }
+                progress = try_to_free_mem_cgroup_pages(mem, GFP_KERNEL,
+                                                false, get_swappiness(mem));
+                if (!progress) {
+                        nr_retries--;
+                        /* maybe some writeback is necessary */
+                        congestion_wait(WRITE, HZ/10);
+                }
+
+        }
+        lru_add_drain();
+        /* try move_account...there may be some *locked* pages. */
+        if (mem->res.usage)
+                goto move_account;
+        ret = 0;
+        goto out;
+}
+
+int mem_cgroup_force_empty_write(struct cgroup *cont, unsigned int event)
+{
+        return mem_cgroup_force_empty(mem_cgroup_from_cont(cont), true);
+}
+
+
+static u64 mem_cgroup_hierarchy_read(struct cgroup *cont, struct cftype *cft)
+{
+        return mem_cgroup_from_cont(cont)->use_hierarchy;
+}
+
+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 cgroup *parent = cont->parent;
+        struct mem_cgroup *parent_mem = NULL;
+
+        if (parent)
+                parent_mem = mem_cgroup_from_cont(parent);
+
+        cgroup_lock();
+        /*
+         * If parent's use_hiearchy is set, we can't make any modifications
+         * in the child subtrees. If it is unset, then the change can
+         * occur, provided the current cgroup has no children.
+         *
+         * 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) &&
+                                (val == 1 || val == 0)) {
+                if (list_empty(&cont->children))
+                        mem->use_hierarchy = val;
+                else
+                        retval = -EBUSY;
+        } else
+                retval = -EINVAL;
+        cgroup_unlock();
+
+        return retval;
 }
 
 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...
@@ -898,15 +1794,22 @@ 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() ? */
@@ -915,27 +1818,59 @@ static int mem_cgroup_write(struct cgroup *cont, struct cftype *cft,
         return ret;
 }
 
+static void memcg_get_hierarchical_limit(struct mem_cgroup *memcg,
+                unsigned long long *mem_limit, unsigned long long *memsw_limit)
+{
+        struct cgroup *cgroup;
+        unsigned long long min_limit, min_memsw_limit, tmp;
+
+        min_limit = res_counter_read_u64(&memcg->res, RES_LIMIT);
+        min_memsw_limit = res_counter_read_u64(&memcg->memsw, RES_LIMIT);
+        cgroup = memcg->css.cgroup;
+        if (!memcg->use_hierarchy)
+                goto out;
+
+        while (cgroup->parent) {
+                cgroup = cgroup->parent;
+                memcg = mem_cgroup_from_cont(cgroup);
+                if (!memcg->use_hierarchy)
+                        break;
+                tmp = res_counter_read_u64(&memcg->res, RES_LIMIT);
+                min_limit = min(min_limit, tmp);
+                tmp = res_counter_read_u64(&memcg->memsw, RES_LIMIT);
+                min_memsw_limit = min(min_memsw_limit, tmp);
+        }
+out:
+        *mem_limit = min_limit;
+        *memsw_limit = min_memsw_limit;
+        return;
+}
+
 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;
 }
 
-static int mem_force_empty_write(struct cgroup *cont, unsigned int event)
-{
-        return mem_cgroup_force_empty(mem_cgroup_from_cont(cont));
-}
-
 static const struct mem_cgroup_stat_desc {
         const char *msg;
         u64 unit;
@@ -984,43 +1919,163 @@ static int mem_control_stat_show(struct cgroup *cont, struct cftype *cft,
                 cb->fill(cb, "unevictable", unevictable * PAGE_SIZE);
 
         }
+        {
+                unsigned long long limit, memsw_limit;
+                memcg_get_hierarchical_limit(mem_cont, &limit, &memsw_limit);
+                cb->fill(cb, "hierarchical_memory_limit", limit);
+                if (do_swap_account)
+                        cb->fill(cb, "hierarchical_memsw_limit", memsw_limit);
+        }
+
+#ifdef CONFIG_DEBUG_VM
+        cb->fill(cb, "inactive_ratio", calc_inactive_ratio(mem_cont, NULL));
+
+        {
+                int nid, zid;
+                struct mem_cgroup_per_zone *mz;
+                unsigned long recent_rotated[2] = {0, 0};
+                unsigned long recent_scanned[2] = {0, 0};
+
+                for_each_online_node(nid)
+                        for (zid = 0; zid < MAX_NR_ZONES; zid++) {
+                                mz = mem_cgroup_zoneinfo(mem_cont, nid, zid);
+
+                                recent_rotated[0] +=
+                                        mz->reclaim_stat.recent_rotated[0];
+                                recent_rotated[1] +=
+                                        mz->reclaim_stat.recent_rotated[1];
+                                recent_scanned[0] +=
+                                        mz->reclaim_stat.recent_scanned[0];
+                                recent_scanned[1] +=
+                                        mz->reclaim_stat.recent_scanned[1];
+                        }
+                cb->fill(cb, "recent_rotated_anon", recent_rotated[0]);
+                cb->fill(cb, "recent_rotated_file", recent_rotated[1]);
+                cb->fill(cb, "recent_scanned_anon", recent_scanned[0]);
+                cb->fill(cb, "recent_scanned_file", recent_scanned[1]);
+        }
+#endif
+
+        return 0;
+}
+
+static u64 mem_cgroup_swappiness_read(struct cgroup *cgrp, struct cftype *cft)
+{
+        struct mem_cgroup *memcg = mem_cgroup_from_cont(cgrp);
+
+        return get_swappiness(memcg);
+}
+
+static int mem_cgroup_swappiness_write(struct cgroup *cgrp, struct cftype *cft,
+                                       u64 val)
+{
+        struct mem_cgroup *memcg = mem_cgroup_from_cont(cgrp);
+        struct mem_cgroup *parent;
+        if (val > 100)
+                return -EINVAL;
+
+        if (cgrp->parent == NULL)
+                return -EINVAL;
+
+        parent = mem_cgroup_from_cont(cgrp->parent);
+        /* If under hierarchy, only empty-root can set this value */
+        if ((parent->use_hierarchy) ||
+            (memcg->use_hierarchy && !list_empty(&cgrp->children)))
+                return -EINVAL;
+
+        spin_lock(&memcg->reclaim_param_lock);
+        memcg->swappiness = val;
+        spin_unlock(&memcg->reclaim_param_lock);
+
         return 0;
 }
 
+
 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,
         },
         {
+                .name = "stat",
+                .read_map = mem_control_stat_show,
+        },
+        {
                 .name = "force_empty",
-                .trigger = mem_force_empty_write,
+                .trigger = mem_cgroup_force_empty_write,
         },
         {
-                .name = "stat",
-                .read_map = mem_control_stat_show,
+                .name = "use_hierarchy",
+                .write_u64 = mem_cgroup_hierarchy_write,
+                .read_u64 = mem_cgroup_hierarchy_read,
+        },
+        {
+                .name = "swappiness",
+                .read_u64 = mem_cgroup_swappiness_read,
+                .write_u64 = mem_cgroup_swappiness_write,
         },
 };
 
+#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;
@@ -1046,7 +2101,6 @@ static int alloc_mem_cgroup_per_zone_info(struct mem_cgroup *mem, int node)
 
         for (zone = 0; zone < MAX_NR_ZONES; zone++) {
                 mz = &pn->zoneinfo[zone];
-                spin_lock_init(&mz->lru_lock);
                 for_each_lru(l)
                         INIT_LIST_HEAD(&mz->lists[l]);
         }
@@ -1058,55 +2112,113 @@ static void free_mem_cgroup_per_zone_info(struct mem_cgroup *mem, int node)
         kfree(mem->info.nodeinfo[node]);
 }
 
+static int mem_cgroup_size(void)
+{
+        int cpustat_size = nr_cpu_ids * sizeof(struct mem_cgroup_stat_cpu);
+        return sizeof(struct mem_cgroup) + cpustat_size;
+}
+
 static struct mem_cgroup *mem_cgroup_alloc(void)
 {
         struct mem_cgroup *mem;
+        int size = mem_cgroup_size();
 
-        if (sizeof(*mem) < PAGE_SIZE)
-                mem = kmalloc(sizeof(*mem), GFP_KERNEL);
+        if (size < PAGE_SIZE)
+                mem = kmalloc(size, GFP_KERNEL);
         else
-                mem = vmalloc(sizeof(*mem));
+                mem = vmalloc(size);
 
         if (mem)
-                memset(mem, 0, sizeof(*mem));
+                memset(mem, 0, size);
         return mem;
 }
 
-static void mem_cgroup_free(struct mem_cgroup *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.
+ *
+ * Removal of cgroup itself succeeds regardless of refs from swap.
+ */
+
+static void __mem_cgroup_free(struct mem_cgroup *mem)
 {
-        if (sizeof(*mem) < PAGE_SIZE)
+        int node;
+
+        for_each_node_state(node, N_POSSIBLE)
+                free_mem_cgroup_per_zone_info(mem, node);
+
+        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))
+                __mem_cgroup_free(mem);
+}
+
+
+#ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP
+static void __init enable_swap_cgroup(void)
+{
+        if (!mem_cgroup_disabled() && really_do_swap_account)
+                do_swap_account = 1;
+}
+#else
+static void __init enable_swap_cgroup(void)
+{
+}
+#endif
 
 static struct cgroup_subsys_state *
 mem_cgroup_create(struct cgroup_subsys *ss, struct cgroup *cont)
 {
-        struct mem_cgroup *mem;
+        struct mem_cgroup *mem, *parent;
         int node;
 
-        if (unlikely((cont->parent) == NULL)) {
-                mem = &init_mem_cgroup;
-        } else {
-                mem = mem_cgroup_alloc();
-                if (!mem)
-                        return ERR_PTR(-ENOMEM);
-        }
-
-        res_counter_init(&mem->res);
+        mem = mem_cgroup_alloc();
+        if (!mem)
+                return ERR_PTR(-ENOMEM);
 
         for_each_node_state(node, N_POSSIBLE)
                 if (alloc_mem_cgroup_per_zone_info(mem, node))
                         goto free_out;
+        /* root ? */
+        if (cont->parent == NULL) {
+                enable_swap_cgroup();
+                parent = NULL;
+        } else {
+                parent = mem_cgroup_from_cont(cont->parent);
+                mem->use_hierarchy = parent->use_hierarchy;
+        }
 
+        if (parent && parent->use_hierarchy) {
+                res_counter_init(&mem->res, &parent->res);
+                res_counter_init(&mem->memsw, &parent->memsw);
+        } else {
+                res_counter_init(&mem->res, NULL);
+                res_counter_init(&mem->memsw, NULL);
+        }
+        mem->last_scanned_child = NULL;
+        spin_lock_init(&mem->reclaim_param_lock);
+
+        if (parent)
+                mem->swappiness = get_swappiness(parent);
+        atomic_set(&mem->refcnt, 1);
         return &mem->css;
 free_out:
-        for_each_node_state(node, N_POSSIBLE)
-                free_mem_cgroup_per_zone_info(mem, node);
-        if (cont->parent != NULL)
-                mem_cgroup_free(mem);
+        __mem_cgroup_free(mem);
         return ERR_PTR(-ENOMEM);
 }
 
@@ -1114,26 +2226,26 @@ static void mem_cgroup_pre_destroy(struct cgroup_subsys *ss,
                                         struct cgroup *cont)
 {
         struct mem_cgroup *mem = mem_cgroup_from_cont(cont);
-        mem_cgroup_force_empty(mem);
+        mem_cgroup_force_empty(mem, false);
 }
 
 static void mem_cgroup_destroy(struct cgroup_subsys *ss,
                                 struct cgroup *cont)
 {
-        int node;
-        struct mem_cgroup *mem = mem_cgroup_from_cont(cont);
-
-        for_each_node_state(node, N_POSSIBLE)
-                free_mem_cgroup_per_zone_info(mem, node);
-
-        mem_cgroup_free(mem_cgroup_from_cont(cont));
+        mem_cgroup_put(mem_cgroup_from_cont(cont));
 }
 
 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,
@@ -1141,25 +2253,12 @@ static void mem_cgroup_move_task(struct cgroup_subsys *ss,
                                 struct cgroup *old_cont,
                                 struct task_struct *p)
 {
-        struct mm_struct *mm;
-        struct mem_cgroup *mem, *old_mem;
-
-        mm = get_task_mm(p);
-        if (mm == NULL)
-                return;
-
-        mem = mem_cgroup_from_cont(cont);
-        old_mem = mem_cgroup_from_cont(old_cont);
-
+        mutex_lock(&memcg_tasklist);
         /*
-         * Only thread group leaders are allowed to migrate, the mm_struct is
-         * in effect owned by the leader
+         * FIXME: It's better to move charges of this process from old
+         * memcg to new memcg. But it's just on TODO-List now.
          */
-        if (!thread_group_leader(p))
-                goto out;
-
-out:
-        mmput(mm);
+        mutex_unlock(&memcg_tasklist);
 }
 
 struct cgroup_subsys mem_cgroup_subsys = {
@@ -1172,3 +2271,13 @@ struct cgroup_subsys mem_cgroup_subsys = {
         .attach = mem_cgroup_move_task,
         .early_init = 0,
 };
+
+#ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP
+
+static int __init disable_swap_account(char *s)
+{
+        really_do_swap_account = 0;
+        return 1;
+}
+__setup("noswapaccount", disable_swap_account);
+#endif