Linux 2.6.31-rc6
[safe/jmp/linux-2.6] / mm / memcontrol.c
index 33fc030..fd4529d 100644 (file)
@@ -27,6 +27,7 @@
 #include <linux/backing-dev.h>
 #include <linux/bit_spinlock.h>
 #include <linux/rcupdate.h>
+#include <linux/limits.h>
 #include <linux/mutex.h>
 #include <linux/slab.h>
 #include <linux/swap.h>
@@ -44,7 +45,7 @@ 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 */
+/* Turned on only when memory cgroup is enabled && really_do_swap_account = 1 */
 int do_swap_account __read_mostly;
 static int really_do_swap_account __initdata = 1; /* for remember boot option*/
 #else
@@ -61,7 +62,8 @@ enum mem_cgroup_stat_index {
         * For MEM_CONTAINER_TYPE_ALL, usage = pagecache + rss.
         */
        MEM_CGROUP_STAT_CACHE,     /* # of pages charged as cache */
-       MEM_CGROUP_STAT_RSS,       /* # of pages charged as rss */
+       MEM_CGROUP_STAT_RSS,       /* # of pages charged as anon rss */
+       MEM_CGROUP_STAT_MAPPED_FILE,  /* # of pages charged as file rss */
        MEM_CGROUP_STAT_PGPGIN_COUNT,   /* # of pages paged in */
        MEM_CGROUP_STAT_PGPGOUT_COUNT,  /* # of pages paged out */
 
@@ -175,6 +177,9 @@ struct mem_cgroup {
 
        unsigned int    swappiness;
 
+       /* set when res.limit == memsw.limit */
+       bool            memsw_is_minimum;
+
        /*
         * statistics. This must be placed at the end of memcg.
         */
@@ -187,6 +192,7 @@ enum charge_type {
        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 */
+       MEM_CGROUP_CHARGE_TYPE_DROP,    /* a page was unused swap cache */
        NR_CHARGE_TYPE,
 };
 
@@ -295,6 +301,9 @@ struct mem_cgroup *mem_cgroup_from_task(struct task_struct *p)
 static struct mem_cgroup *try_get_mem_cgroup_from_mm(struct mm_struct *mm)
 {
        struct mem_cgroup *mem = NULL;
+
+       if (!mm)
+               return 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
@@ -310,14 +319,6 @@ static struct mem_cgroup *try_get_mem_cgroup_from_mm(struct mm_struct *mm)
        return mem;
 }
 
-static bool mem_cgroup_is_obsolete(struct mem_cgroup *mem)
-{
-       if (!mem)
-               return true;
-       return css_is_removed(&mem->css);
-}
-
-
 /*
  * Call callback function against all cgroup under hierarchy tree.
  */
@@ -486,31 +487,24 @@ void mem_cgroup_move_lists(struct page *page,
 int task_in_mem_cgroup(struct task_struct *task, const struct mem_cgroup *mem)
 {
        int ret;
+       struct mem_cgroup *curr = NULL;
 
        task_lock(task);
-       ret = task->mm && mm_match_cgroup(task->mm, mem);
+       rcu_read_lock();
+       curr = try_get_mem_cgroup_from_mm(task->mm);
+       rcu_read_unlock();
        task_unlock(task);
+       if (!curr)
+               return 0;
+       if (curr->use_hierarchy)
+               ret = css_is_ancestor(&curr->css, &mem->css);
+       else
+               ret = (curr == mem);
+       css_put(&curr->css);
        return ret;
 }
 
 /*
- * Calculate mapped_ratio under memory controller. This will be used in
- * vmscan.c for deteremining we have to reclaim mapped pages.
- */
-int mem_cgroup_calc_mapped_ratio(struct mem_cgroup *mem)
-{
-       long total, rss;
-
-       /*
-        * usage is recorded in bytes. But, here, we assume the number of
-        * physical pages can be represented by "long" on any arch.
-        */
-       total = (long) (mem->res.usage >> PAGE_SHIFT) + 1L;
-       rss = (long)mem_cgroup_read_stat(&mem->stat, MEM_CGROUP_STAT_RSS);
-       return (int)((rss * 100L) / total);
-}
-
-/*
  * prev_priority control...this will be used in memory reclaim path.
  */
 int mem_cgroup_get_reclaim_priority(struct mem_cgroup *mem)
@@ -581,6 +575,17 @@ int mem_cgroup_inactive_anon_is_low(struct mem_cgroup *memcg)
        return 0;
 }
 
+int mem_cgroup_inactive_file_is_low(struct mem_cgroup *memcg)
+{
+       unsigned long active;
+       unsigned long inactive;
+
+       inactive = mem_cgroup_get_local_zonestat(memcg, LRU_INACTIVE_FILE);
+       active = mem_cgroup_get_local_zonestat(memcg, LRU_ACTIVE_FILE);
+
+       return (active > inactive);
+}
+
 unsigned long mem_cgroup_zone_nr_pages(struct mem_cgroup *memcg,
                                       struct zone *zone,
                                       enum lru_list lru)
@@ -644,6 +649,7 @@ unsigned long mem_cgroup_isolate_pages(unsigned long nr_to_scan,
        int zid = zone_idx(z);
        struct mem_cgroup_per_zone *mz;
        int lru = LRU_FILE * !!file + !!active;
+       int ret;
 
        BUG_ON(!mem_cont);
        mz = mem_cgroup_zoneinfo(mem_cont, nid, zid);
@@ -661,9 +667,19 @@ unsigned long mem_cgroup_isolate_pages(unsigned long nr_to_scan,
                        continue;
 
                scan++;
-               if (__isolate_lru_page(page, mode, file) == 0) {
+               ret = __isolate_lru_page(page, mode, file);
+               switch (ret) {
+               case 0:
                        list_move(&page->lru, dst);
+                       mem_cgroup_del_lru(page);
                        nr_taken++;
+                       break;
+               case -EBUSY:
+                       /* we don't affect global LRU but rotate in our LRU */
+                       mem_cgroup_rotate_lru_list(page, page_lru(page));
+                       break;
+               default:
+                       break;
                }
        }
 
@@ -702,6 +718,91 @@ static unsigned int get_swappiness(struct mem_cgroup *memcg)
        return swappiness;
 }
 
+static int mem_cgroup_count_children_cb(struct mem_cgroup *mem, void *data)
+{
+       int *val = data;
+       (*val)++;
+       return 0;
+}
+
+/**
+ * mem_cgroup_print_mem_info: Called from OOM with tasklist_lock held in read mode.
+ * @memcg: The memory cgroup that went over limit
+ * @p: Task that is going to be killed
+ *
+ * NOTE: @memcg and @p's mem_cgroup can be different when hierarchy is
+ * enabled
+ */
+void mem_cgroup_print_oom_info(struct mem_cgroup *memcg, struct task_struct *p)
+{
+       struct cgroup *task_cgrp;
+       struct cgroup *mem_cgrp;
+       /*
+        * Need a buffer in BSS, can't rely on allocations. The code relies
+        * on the assumption that OOM is serialized for memory controller.
+        * If this assumption is broken, revisit this code.
+        */
+       static char memcg_name[PATH_MAX];
+       int ret;
+
+       if (!memcg)
+               return;
+
+
+       rcu_read_lock();
+
+       mem_cgrp = memcg->css.cgroup;
+       task_cgrp = task_cgroup(p, mem_cgroup_subsys_id);
+
+       ret = cgroup_path(task_cgrp, memcg_name, PATH_MAX);
+       if (ret < 0) {
+               /*
+                * Unfortunately, we are unable to convert to a useful name
+                * But we'll still print out the usage information
+                */
+               rcu_read_unlock();
+               goto done;
+       }
+       rcu_read_unlock();
+
+       printk(KERN_INFO "Task in %s killed", memcg_name);
+
+       rcu_read_lock();
+       ret = cgroup_path(mem_cgrp, memcg_name, PATH_MAX);
+       if (ret < 0) {
+               rcu_read_unlock();
+               goto done;
+       }
+       rcu_read_unlock();
+
+       /*
+        * Continues from above, so we don't need an KERN_ level
+        */
+       printk(KERN_CONT " as a result of limit of %s\n", memcg_name);
+done:
+
+       printk(KERN_INFO "memory: usage %llukB, limit %llukB, failcnt %llu\n",
+               res_counter_read_u64(&memcg->res, RES_USAGE) >> 10,
+               res_counter_read_u64(&memcg->res, RES_LIMIT) >> 10,
+               res_counter_read_u64(&memcg->res, RES_FAILCNT));
+       printk(KERN_INFO "memory+swap: usage %llukB, limit %llukB, "
+               "failcnt %llu\n",
+               res_counter_read_u64(&memcg->memsw, RES_USAGE) >> 10,
+               res_counter_read_u64(&memcg->memsw, RES_LIMIT) >> 10,
+               res_counter_read_u64(&memcg->memsw, RES_FAILCNT));
+}
+
+/*
+ * This function returns the number of memcg under hierarchy tree. Returns
+ * 1(self count) if no children.
+ */
+static int mem_cgroup_count_children(struct mem_cgroup *mem)
+{
+       int num = 0;
+       mem_cgroup_walk_tree(mem, &num, mem_cgroup_count_children_cb);
+       return num;
+}
+
 /*
  * 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
@@ -750,14 +851,20 @@ mem_cgroup_select_victim(struct mem_cgroup *root_mem)
  *
  * We give up and return to the caller when we visit root_mem twice.
  * (other groups can be removed while we're walking....)
+ *
+ * If shrink==true, for avoiding to free too much, this returns immedieately.
  */
 static int mem_cgroup_hierarchical_reclaim(struct mem_cgroup *root_mem,
-                                               gfp_t gfp_mask, bool noswap)
+                                  gfp_t gfp_mask, bool noswap, bool shrink)
 {
        struct mem_cgroup *victim;
        int ret, total = 0;
        int loop = 0;
 
+       /* If memsw_is_minimum==1, swap-out is of-no-use. */
+       if (root_mem->memsw_is_minimum)
+               noswap = true;
+
        while (loop < 2) {
                victim = mem_cgroup_select_victim(root_mem);
                if (victim == root_mem)
@@ -771,6 +878,13 @@ static int mem_cgroup_hierarchical_reclaim(struct mem_cgroup *root_mem,
                ret = try_to_free_mem_cgroup_pages(victim, gfp_mask, noswap,
                                                   get_swappiness(victim));
                css_put(&victim->css);
+               /*
+                * At shrinking usage, we can't check we should stop here or
+                * reclaim more. It's depends on callers. last_scanned_child
+                * will work enough for keeping fairness under tree.
+                */
+               if (shrink)
+                       return ret;
                total += ret;
                if (mem_cgroup_check_under_limit(root_mem))
                        return 1 + total;
@@ -794,6 +908,57 @@ bool mem_cgroup_oom_called(struct task_struct *task)
        rcu_read_unlock();
        return ret;
 }
+
+static int record_last_oom_cb(struct mem_cgroup *mem, void *data)
+{
+       mem->last_oom_jiffies = jiffies;
+       return 0;
+}
+
+static void record_last_oom(struct mem_cgroup *mem)
+{
+       mem_cgroup_walk_tree(mem, NULL, record_last_oom_cb);
+}
+
+/*
+ * Currently used to update mapped file statistics, but the routine can be
+ * generalized to update other statistics as well.
+ */
+void mem_cgroup_update_mapped_file_stat(struct page *page, int val)
+{
+       struct mem_cgroup *mem;
+       struct mem_cgroup_stat *stat;
+       struct mem_cgroup_stat_cpu *cpustat;
+       int cpu;
+       struct page_cgroup *pc;
+
+       if (!page_is_file_cache(page))
+               return;
+
+       pc = lookup_page_cgroup(page);
+       if (unlikely(!pc))
+               return;
+
+       lock_page_cgroup(pc);
+       mem = pc->mem_cgroup;
+       if (!mem)
+               goto done;
+
+       if (!PageCgroupUsed(pc))
+               goto done;
+
+       /*
+        * Preemption is already disabled, we don't need get_cpu()
+        */
+       cpu = smp_processor_id();
+       stat = &mem->stat;
+       cpustat = &stat->cpustat[cpu];
+
+       __mem_cgroup_stat_add_safe(cpustat, MEM_CGROUP_STAT_MAPPED_FILE, val);
+done:
+       unlock_page_cgroup(pc);
+}
+
 /*
  * Unlike exported interface, "oom" parameter is added. if oom==true,
  * oom-killer can be invoked.
@@ -828,7 +993,7 @@ static int __mem_cgroup_try_charge(struct mm_struct *mm,
        if (unlikely(!mem))
                return 0;
 
-       VM_BUG_ON(mem_cgroup_is_obsolete(mem));
+       VM_BUG_ON(css_is_removed(&mem->css));
 
        while (1) {
                int ret;
@@ -856,7 +1021,7 @@ static int __mem_cgroup_try_charge(struct mm_struct *mm,
                        goto nomem;
 
                ret = mem_cgroup_hierarchical_reclaim(mem_over_limit, gfp_mask,
-                                                       noswap);
+                                                       noswap, false);
                if (ret)
                        continue;
 
@@ -876,7 +1041,7 @@ static int __mem_cgroup_try_charge(struct mm_struct *mm,
                                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;
+                               record_last_oom(mem_over_limit);
                        }
                        goto nomem;
                }
@@ -887,20 +1052,54 @@ nomem:
        return -ENOMEM;
 }
 
+
+/*
+ * A helper function to get mem_cgroup from ID. must be called under
+ * rcu_read_lock(). The caller must check css_is_removed() or some if
+ * it's concern. (dropping refcnt from swap can be called against removed
+ * memcg.)
+ */
+static struct mem_cgroup *mem_cgroup_lookup(unsigned short id)
+{
+       struct cgroup_subsys_state *css;
+
+       /* ID 0 is unused ID */
+       if (!id)
+               return NULL;
+       css = css_lookup(&mem_cgroup_subsys, id);
+       if (!css)
+               return NULL;
+       return container_of(css, struct mem_cgroup, css);
+}
+
 static struct mem_cgroup *try_get_mem_cgroup_from_swapcache(struct page *page)
 {
        struct mem_cgroup *mem;
+       struct page_cgroup *pc;
+       unsigned short id;
        swp_entry_t ent;
 
+       VM_BUG_ON(!PageLocked(page));
+
        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;
+       pc = lookup_page_cgroup(page);
+       lock_page_cgroup(pc);
+       if (PageCgroupUsed(pc)) {
+               mem = pc->mem_cgroup;
+               if (mem && !css_tryget(&mem->css))
+                       mem = NULL;
+       } else {
+               ent.val = page_private(page);
+               id = lookup_swap_cgroup(ent);
+               rcu_read_lock();
+               mem = mem_cgroup_lookup(id);
+               if (mem && !css_tryget(&mem->css))
+                       mem = NULL;
+               rcu_read_unlock();
+       }
+       unlock_page_cgroup(pc);
        return mem;
 }
 
@@ -957,6 +1156,10 @@ static int mem_cgroup_move_account(struct page_cgroup *pc,
        struct mem_cgroup_per_zone *from_mz, *to_mz;
        int nid, zid;
        int ret = -EBUSY;
+       struct page *page;
+       int cpu;
+       struct mem_cgroup_stat *stat;
+       struct mem_cgroup_stat_cpu *cpustat;
 
        VM_BUG_ON(from == to);
        VM_BUG_ON(PageLRU(pc->page));
@@ -977,6 +1180,23 @@ static int mem_cgroup_move_account(struct page_cgroup *pc,
 
        res_counter_uncharge(&from->res, PAGE_SIZE);
        mem_cgroup_charge_statistics(from, pc, false);
+
+       page = pc->page;
+       if (page_is_file_cache(page) && page_mapped(page)) {
+               cpu = smp_processor_id();
+               /* Update mapped_file data for mem_cgroup "from" */
+               stat = &from->stat;
+               cpustat = &stat->cpustat[cpu];
+               __mem_cgroup_stat_add_safe(cpustat, MEM_CGROUP_STAT_MAPPED_FILE,
+                                               -1);
+
+               /* Update mapped_file data for mem_cgroup "to" */
+               stat = &to->stat;
+               cpustat = &stat->cpustat[cpu];
+               __mem_cgroup_stat_add_safe(cpustat, MEM_CGROUP_STAT_MAPPED_FILE,
+                                               1);
+       }
+
        if (do_swap_account)
                res_counter_uncharge(&from->memsw, PAGE_SIZE);
        css_put(&from->css);
@@ -987,6 +1207,12 @@ static int mem_cgroup_move_account(struct page_cgroup *pc,
        ret = 0;
 out:
        unlock_page_cgroup(pc);
+       /*
+        * We charges against "to" which may not have any tasks. Then, "to"
+        * can be under rmdir(). But in current implementation, caller of
+        * this function is just force_empty() and it's garanteed that
+        * "to" is never removed. So, we don't check rmdir status here.
+        */
        return ret;
 }
 
@@ -1099,6 +1325,10 @@ int mem_cgroup_newpage_charge(struct page *page,
                                MEM_CGROUP_CHARGE_TYPE_MAPPED, NULL);
 }
 
+static void
+__mem_cgroup_commit_charge_swapin(struct page *page, struct mem_cgroup *ptr,
+                                       enum charge_type ctype);
+
 int mem_cgroup_cache_charge(struct page *page, struct mm_struct *mm,
                                gfp_t gfp_mask)
 {
@@ -1135,16 +1365,6 @@ int mem_cgroup_cache_charge(struct page *page, struct mm_struct *mm,
                unlock_page_cgroup(pc);
        }
 
-       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;
 
@@ -1152,22 +1372,16 @@ int mem_cgroup_cache_charge(struct page *page, struct mm_struct *mm,
                return mem_cgroup_charge_common(page, mm, gfp_mask,
                                MEM_CGROUP_CHARGE_TYPE_CACHE, 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);
+       /* shmem */
+       if (PageSwapCache(page)) {
+               ret = mem_cgroup_try_charge_swapin(mm, page, gfp_mask, &mem);
+               if (!ret)
+                       __mem_cgroup_commit_charge_swapin(page, mem,
+                                       MEM_CGROUP_CHARGE_TYPE_SHMEM);
+       } else
+               ret = mem_cgroup_charge_common(page, mm, gfp_mask,
+                                       MEM_CGROUP_CHARGE_TYPE_SHMEM, mem);
 
-       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;
 }
 
@@ -1210,7 +1424,9 @@ charge_cur_mm:
        return __mem_cgroup_try_charge(mm, mask, ptr, true);
 }
 
-void mem_cgroup_commit_charge_swapin(struct page *page, struct mem_cgroup *ptr)
+static void
+__mem_cgroup_commit_charge_swapin(struct page *page, struct mem_cgroup *ptr,
+                                       enum charge_type ctype)
 {
        struct page_cgroup *pc;
 
@@ -1218,9 +1434,10 @@ void mem_cgroup_commit_charge_swapin(struct page *page, struct mem_cgroup *ptr)
                return;
        if (!ptr)
                return;
+       cgroup_exclude_rmdir(&ptr->css);
        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_commit_charge(ptr, pc, ctype);
        mem_cgroup_lru_add_after_commit_swapcache(page);
        /*
         * Now swap is on-memory. This means this page may be
@@ -1231,16 +1448,34 @@ void mem_cgroup_commit_charge_swapin(struct page *page, struct mem_cgroup *ptr)
         */
        if (do_swap_account && PageSwapCache(page)) {
                swp_entry_t ent = {.val = page_private(page)};
+               unsigned short id;
                struct mem_cgroup *memcg;
-               memcg = swap_cgroup_record(ent, NULL);
+
+               id = swap_cgroup_record(ent, 0);
+               rcu_read_lock();
+               memcg = mem_cgroup_lookup(id);
                if (memcg) {
+                       /*
+                        * This recorded memcg can be obsolete one. So, avoid
+                        * calling css_tryget
+                        */
                        res_counter_uncharge(&memcg->memsw, PAGE_SIZE);
                        mem_cgroup_put(memcg);
                }
-
+               rcu_read_unlock();
        }
-       /* add this page(page_cgroup) to the LRU we want. */
+       /*
+        * At swapin, we may charge account against cgroup which has no tasks.
+        * So, rmdir()->pre_destroy() can be called while we do this charge.
+        * In that case, we need to call pre_destroy() again. check it here.
+        */
+       cgroup_release_and_wakeup_rmdir(&ptr->css);
+}
 
+void mem_cgroup_commit_charge_swapin(struct page *page, struct mem_cgroup *ptr)
+{
+       __mem_cgroup_commit_charge_swapin(page, ptr,
+                                       MEM_CGROUP_CHARGE_TYPE_MAPPED);
 }
 
 void mem_cgroup_cancel_charge_swapin(struct mem_cgroup *mem)
@@ -1288,6 +1523,7 @@ __mem_cgroup_uncharge_common(struct page *page, enum charge_type ctype)
 
        switch (ctype) {
        case MEM_CGROUP_CHARGE_TYPE_MAPPED:
+       case MEM_CGROUP_CHARGE_TYPE_DROP:
                if (page_mapped(page))
                        goto unlock_out;
                break;
@@ -1346,24 +1582,31 @@ void mem_cgroup_uncharge_cache_page(struct page *page)
        __mem_cgroup_uncharge_common(page, MEM_CGROUP_CHARGE_TYPE_CACHE);
 }
 
+#ifdef CONFIG_SWAP
 /*
- * called from __delete_from_swap_cache() and drop "page" account.
+ * called after __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)
+void
+mem_cgroup_uncharge_swapcache(struct page *page, swp_entry_t ent, bool swapout)
 {
        struct mem_cgroup *memcg;
+       int ctype = MEM_CGROUP_CHARGE_TYPE_SWAPOUT;
+
+       if (!swapout) /* this was a swap cache but the swap is unused ! */
+               ctype = MEM_CGROUP_CHARGE_TYPE_DROP;
+
+       memcg = __mem_cgroup_uncharge_common(page, ctype);
 
-       memcg = __mem_cgroup_uncharge_common(page,
-                                       MEM_CGROUP_CHARGE_TYPE_SWAPOUT);
        /* record memcg information */
-       if (do_swap_account && memcg) {
-               swap_cgroup_record(ent, memcg);
+       if (do_swap_account && swapout && memcg) {
+               swap_cgroup_record(ent, css_id(&memcg->css));
                mem_cgroup_get(memcg);
        }
-       if (memcg)
+       if (swapout && memcg)
                css_put(&memcg->css);
 }
+#endif
 
 #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP
 /*
@@ -1373,15 +1616,23 @@ void mem_cgroup_uncharge_swapcache(struct page *page, swp_entry_t ent)
 void mem_cgroup_uncharge_swap(swp_entry_t ent)
 {
        struct mem_cgroup *memcg;
+       unsigned short id;
 
        if (!do_swap_account)
                return;
 
-       memcg = swap_cgroup_record(ent, NULL);
+       id = swap_cgroup_record(ent, 0);
+       rcu_read_lock();
+       memcg = mem_cgroup_lookup(id);
        if (memcg) {
+               /*
+                * We uncharge this because swap is freed.
+                * This memcg can be obsolete one. We avoid calling css_tryget
+                */
                res_counter_uncharge(&memcg->memsw, PAGE_SIZE);
                mem_cgroup_put(memcg);
        }
+       rcu_read_unlock();
 }
 #endif
 
@@ -1424,7 +1675,7 @@ void mem_cgroup_end_migration(struct mem_cgroup *mem,
 
        if (!mem)
                return;
-
+       cgroup_exclude_rmdir(&mem->css);
        /* at migration success, oldpage->mapping is NULL. */
        if (oldpage->mapping) {
                target = oldpage;
@@ -1464,39 +1715,37 @@ void mem_cgroup_end_migration(struct mem_cgroup *mem,
         */
        if (ctype == MEM_CGROUP_CHARGE_TYPE_MAPPED)
                mem_cgroup_uncharge_page(target);
+       /*
+        * At migration, we may charge account against cgroup which has no tasks
+        * So, rmdir()->pre_destroy() can be called while we do this charge.
+        * In that case, we need to call pre_destroy() again. check it here.
+        */
+       cgroup_release_and_wakeup_rmdir(&mem->css);
 }
 
 /*
- * A call to try to shrink memory usage under specified resource controller.
- * 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.
+ * A call to try to shrink memory usage on charge failure at shmem's swapin.
+ * Calling hierarchical_reclaim is not enough because we should update
+ * last_oom_jiffies to prevent pagefault_out_of_memory from invoking global OOM.
+ * Moreover considering hierarchy, we should reclaim from the mem_over_limit,
+ * not from the memcg which this page would be charged to.
+ * try_charge_swapin does all of these works properly.
  */
-int mem_cgroup_shrink_usage(struct page *page,
+int mem_cgroup_shmem_charge_fallback(struct page *page,
                            struct mm_struct *mm,
                            gfp_t gfp_mask)
 {
        struct mem_cgroup *mem = NULL;
-       int progress = 0;
-       int retry = MEM_CGROUP_RECLAIM_RETRIES;
+       int ret;
 
        if (mem_cgroup_disabled())
                return 0;
-       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;
 
-       do {
-               progress = mem_cgroup_hierarchical_reclaim(mem, gfp_mask, true);
-               progress += mem_cgroup_check_under_limit(mem);
-       } while (!progress && --retry);
+       ret = mem_cgroup_try_charge_swapin(mm, page, gfp_mask, &mem);
+       if (!ret)
+               mem_cgroup_cancel_charge_swapin(mem); /* it does !mem check */
 
-       css_put(&mem->css);
-       if (!retry)
-               return -ENOMEM;
-       return 0;
+       return ret;
 }
 
 static DEFINE_MUTEX(set_limit_mutex);
@@ -1504,11 +1753,21 @@ 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 retry_count;
        int progress;
        u64 memswlimit;
        int ret = 0;
+       int children = mem_cgroup_count_children(memcg);
+       u64 curusage, oldusage;
+
+       /*
+        * For keeping hierarchical_reclaim simple, how long we should retry
+        * is depends on callers. We set our retry-count to be function
+        * of # of children which we should visit in this loop.
+        */
+       retry_count = MEM_CGROUP_RECLAIM_RETRIES * children;
+
+       oldusage = res_counter_read_u64(&memcg->res, RES_USAGE);
 
        while (retry_count) {
                if (signal_pending(current)) {
@@ -1528,29 +1787,41 @@ static int mem_cgroup_resize_limit(struct mem_cgroup *memcg,
                        break;
                }
                ret = res_counter_set_limit(&memcg->res, val);
+               if (!ret) {
+                       if (memswlimit == val)
+                               memcg->memsw_is_minimum = true;
+                       else
+                               memcg->memsw_is_minimum = false;
+               }
                mutex_unlock(&set_limit_mutex);
 
                if (!ret)
                        break;
 
                progress = mem_cgroup_hierarchical_reclaim(memcg, GFP_KERNEL,
-                                                          false);
-               if (!progress)                  retry_count--;
+                                                  false, true);
+               curusage = res_counter_read_u64(&memcg->res, RES_USAGE);
+               /* Usage is reduced ? */
+               if (curusage >= oldusage)
+                       retry_count--;
+               else
+                       oldusage = curusage;
        }
 
        return ret;
 }
 
-int mem_cgroup_resize_memsw_limit(struct mem_cgroup *memcg,
-                               unsigned long long val)
+static int mem_cgroup_resize_memsw_limit(struct mem_cgroup *memcg,
+                                       unsigned long long val)
 {
-       int retry_count = MEM_CGROUP_RECLAIM_RETRIES;
+       int retry_count;
        u64 memlimit, oldusage, curusage;
-       int ret;
-
-       if (!do_swap_account)
-               return -EINVAL;
+       int children = mem_cgroup_count_children(memcg);
+       int ret = -EBUSY;
 
+       /* see mem_cgroup_resize_res_limit */
+       retry_count = children * MEM_CGROUP_RECLAIM_RETRIES;
+       oldusage = res_counter_read_u64(&memcg->memsw, RES_USAGE);
        while (retry_count) {
                if (signal_pending(current)) {
                        ret = -EINTR;
@@ -1569,16 +1840,24 @@ int mem_cgroup_resize_memsw_limit(struct mem_cgroup *memcg,
                        break;
                }
                ret = res_counter_set_limit(&memcg->memsw, val);
+               if (!ret) {
+                       if (memlimit == val)
+                               memcg->memsw_is_minimum = true;
+                       else
+                               memcg->memsw_is_minimum = false;
+               }
                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);
+               mem_cgroup_hierarchical_reclaim(memcg, GFP_KERNEL, true, true);
                curusage = res_counter_read_u64(&memcg->memsw, RES_USAGE);
+               /* Usage is reduced ? */
                if (curusage >= oldusage)
                        retry_count--;
+               else
+                       oldusage = curusage;
        }
        return ret;
 }
@@ -1711,7 +1990,7 @@ try_to_free:
                if (!progress) {
                        nr_retries--;
                        /* maybe some writeback is necessary */
-                       congestion_wait(WRITE, HZ/10);
+                       congestion_wait(BLK_RW_ASYNC, HZ/10);
                }
 
        }
@@ -1780,8 +2059,7 @@ static u64 mem_cgroup_read(struct cgroup *cont, struct cftype *cft)
                val = res_counter_read_u64(&mem->res, name);
                break;
        case _MEMSWAP:
-               if (do_swap_account)
-                       val = res_counter_read_u64(&mem->memsw, name);
+               val = res_counter_read_u64(&mem->memsw, name);
                break;
        default:
                BUG();
@@ -1879,6 +2157,7 @@ static int mem_cgroup_reset(struct cgroup *cont, unsigned int event)
 enum {
        MCS_CACHE,
        MCS_RSS,
+       MCS_MAPPED_FILE,
        MCS_PGPGIN,
        MCS_PGPGOUT,
        MCS_INACTIVE_ANON,
@@ -1899,6 +2178,7 @@ struct {
 } memcg_stat_strings[NR_MCS_STAT] = {
        {"cache", "total_cache"},
        {"rss", "total_rss"},
+       {"mapped_file", "total_mapped_file"},
        {"pgpgin", "total_pgpgin"},
        {"pgpgout", "total_pgpgout"},
        {"inactive_anon", "total_inactive_anon"},
@@ -1919,6 +2199,8 @@ static int mem_cgroup_get_local_stat(struct mem_cgroup *mem, void *data)
        s->stat[MCS_CACHE] += val * PAGE_SIZE;
        val = mem_cgroup_read_stat(&mem->stat, MEM_CGROUP_STAT_RSS);
        s->stat[MCS_RSS] += val * PAGE_SIZE;
+       val = mem_cgroup_read_stat(&mem->stat, MEM_CGROUP_STAT_MAPPED_FILE);
+       s->stat[MCS_MAPPED_FILE] += val * PAGE_SIZE;
        val = mem_cgroup_read_stat(&mem->stat, MEM_CGROUP_STAT_PGPGIN_COUNT);
        s->stat[MCS_PGPGIN] += val;
        val = mem_cgroup_read_stat(&mem->stat, MEM_CGROUP_STAT_PGPGOUT_COUNT);