Merge branch 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs
[cascardo/linux.git] / mm / memcontrol.c
index 4217461..4baddba 100644 (file)
@@ -373,7 +373,6 @@ static void mem_cgroup_put(struct mem_cgroup *memcg);
 
 /* Writing them here to avoid exposing memcg's inner layout */
 #ifdef CONFIG_CGROUP_MEM_RES_CTLR_KMEM
-#ifdef CONFIG_INET
 #include <net/sock.h>
 #include <net/ip.h>
 
@@ -420,6 +419,7 @@ void sock_release_memcg(struct sock *sk)
        }
 }
 
+#ifdef CONFIG_INET
 struct cg_proto *tcp_proto_cgroup(struct mem_cgroup *memcg)
 {
        if (!memcg || mem_cgroup_is_root(memcg))
@@ -565,7 +565,7 @@ static void mem_cgroup_remove_from_trees(struct mem_cgroup *memcg)
        struct mem_cgroup_per_zone *mz;
        struct mem_cgroup_tree_per_zone *mctz;
 
-       for_each_node_state(node, N_POSSIBLE) {
+       for_each_node(node) {
                for (zone = 0; zone < MAX_NR_ZONES; zone++) {
                        mz = mem_cgroup_zoneinfo(memcg, node, zone);
                        mctz = soft_limit_tree_node_zone(node, zone);
@@ -655,16 +655,6 @@ static void mem_cgroup_swap_statistics(struct mem_cgroup *memcg,
        this_cpu_add(memcg->stat->count[MEM_CGROUP_STAT_SWAPOUT], val);
 }
 
-void mem_cgroup_pgfault(struct mem_cgroup *memcg, int val)
-{
-       this_cpu_add(memcg->stat->events[MEM_CGROUP_EVENTS_PGFAULT], val);
-}
-
-void mem_cgroup_pgmajfault(struct mem_cgroup *memcg, int val)
-{
-       this_cpu_add(memcg->stat->events[MEM_CGROUP_EVENTS_PGMAJFAULT], val);
-}
-
 static unsigned long mem_cgroup_read_events(struct mem_cgroup *memcg,
                                            enum mem_cgroup_events_index idx)
 {
@@ -748,37 +738,32 @@ static unsigned long mem_cgroup_nr_lru_pages(struct mem_cgroup *memcg,
        return total;
 }
 
-static bool __memcg_event_check(struct mem_cgroup *memcg, int target)
+static bool mem_cgroup_event_ratelimit(struct mem_cgroup *memcg,
+                                      enum mem_cgroup_events_target target)
 {
        unsigned long val, next;
 
        val = __this_cpu_read(memcg->stat->events[MEM_CGROUP_EVENTS_COUNT]);
        next = __this_cpu_read(memcg->stat->targets[target]);
        /* from time_after() in jiffies.h */
-       return ((long)next - (long)val < 0);
-}
-
-static void __mem_cgroup_target_update(struct mem_cgroup *memcg, int target)
-{
-       unsigned long val, next;
-
-       val = __this_cpu_read(memcg->stat->events[MEM_CGROUP_EVENTS_COUNT]);
-
-       switch (target) {
-       case MEM_CGROUP_TARGET_THRESH:
-               next = val + THRESHOLDS_EVENTS_TARGET;
-               break;
-       case MEM_CGROUP_TARGET_SOFTLIMIT:
-               next = val + SOFTLIMIT_EVENTS_TARGET;
-               break;
-       case MEM_CGROUP_TARGET_NUMAINFO:
-               next = val + NUMAINFO_EVENTS_TARGET;
-               break;
-       default:
-               return;
+       if ((long)next - (long)val < 0) {
+               switch (target) {
+               case MEM_CGROUP_TARGET_THRESH:
+                       next = val + THRESHOLDS_EVENTS_TARGET;
+                       break;
+               case MEM_CGROUP_TARGET_SOFTLIMIT:
+                       next = val + SOFTLIMIT_EVENTS_TARGET;
+                       break;
+               case MEM_CGROUP_TARGET_NUMAINFO:
+                       next = val + NUMAINFO_EVENTS_TARGET;
+                       break;
+               default:
+                       break;
+               }
+               __this_cpu_write(memcg->stat->targets[target], next);
+               return true;
        }
-
-       __this_cpu_write(memcg->stat->targets[target], next);
+       return false;
 }
 
 /*
@@ -789,25 +774,27 @@ static void memcg_check_events(struct mem_cgroup *memcg, struct page *page)
 {
        preempt_disable();
        /* threshold event is triggered in finer grain than soft limit */
-       if (unlikely(__memcg_event_check(memcg, MEM_CGROUP_TARGET_THRESH))) {
+       if (unlikely(mem_cgroup_event_ratelimit(memcg,
+                                               MEM_CGROUP_TARGET_THRESH))) {
+               bool do_softlimit, do_numainfo;
+
+               do_softlimit = mem_cgroup_event_ratelimit(memcg,
+                                               MEM_CGROUP_TARGET_SOFTLIMIT);
+#if MAX_NUMNODES > 1
+               do_numainfo = mem_cgroup_event_ratelimit(memcg,
+                                               MEM_CGROUP_TARGET_NUMAINFO);
+#endif
+               preempt_enable();
+
                mem_cgroup_threshold(memcg);
-               __mem_cgroup_target_update(memcg, MEM_CGROUP_TARGET_THRESH);
-               if (unlikely(__memcg_event_check(memcg,
-                            MEM_CGROUP_TARGET_SOFTLIMIT))) {
+               if (unlikely(do_softlimit))
                        mem_cgroup_update_tree(memcg, page);
-                       __mem_cgroup_target_update(memcg,
-                                                  MEM_CGROUP_TARGET_SOFTLIMIT);
-               }
 #if MAX_NUMNODES > 1
-               if (unlikely(__memcg_event_check(memcg,
-                       MEM_CGROUP_TARGET_NUMAINFO))) {
+               if (unlikely(do_numainfo))
                        atomic_inc(&memcg->numainfo_events);
-                       __mem_cgroup_target_update(memcg,
-                               MEM_CGROUP_TARGET_NUMAINFO);
-               }
 #endif
-       }
-       preempt_enable();
+       } else
+               preempt_enable();
 }
 
 struct mem_cgroup *mem_cgroup_from_cont(struct cgroup *cont)
@@ -981,11 +968,11 @@ void mem_cgroup_count_vm_event(struct mm_struct *mm, enum vm_event_item idx)
                goto out;
 
        switch (idx) {
-       case PGMAJFAULT:
-               mem_cgroup_pgmajfault(memcg, 1);
-               break;
        case PGFAULT:
-               mem_cgroup_pgfault(memcg, 1);
+               this_cpu_inc(memcg->stat->events[MEM_CGROUP_EVENTS_PGFAULT]);
+               break;
+       case PGMAJFAULT:
+               this_cpu_inc(memcg->stat->events[MEM_CGROUP_EVENTS_PGMAJFAULT]);
                break;
        default:
                BUG();
@@ -1053,30 +1040,7 @@ struct lruvec *mem_cgroup_lru_add_list(struct zone *zone, struct page *page,
                return &zone->lruvec;
 
        pc = lookup_page_cgroup(page);
-       VM_BUG_ON(PageCgroupAcctLRU(pc));
-       /*
-        * putback:                             charge:
-        * SetPageLRU                           SetPageCgroupUsed
-        * smp_mb                               smp_mb
-        * PageCgroupUsed && add to memcg LRU   PageLRU && add to memcg LRU
-        *
-        * Ensure that one of the two sides adds the page to the memcg
-        * LRU during a race.
-        */
-       smp_mb();
-       /*
-        * If the page is uncharged, it may be freed soon, but it
-        * could also be swap cache (readahead, swapoff) that needs to
-        * be reclaimable in the future.  root_mem_cgroup will babysit
-        * it for the time being.
-        */
-       if (PageCgroupUsed(pc)) {
-               /* Ensure pc->mem_cgroup is visible after reading PCG_USED. */
-               smp_rmb();
-               memcg = pc->mem_cgroup;
-               SetPageCgroupAcctLRU(pc);
-       } else
-               memcg = root_mem_cgroup;
+       memcg = pc->mem_cgroup;
        mz = page_cgroup_zoneinfo(memcg, page);
        /* compound_order() is stabilized through lru_lock */
        MEM_CGROUP_ZSTAT(mz, lru) += 1 << compound_order(page);
@@ -1103,20 +1067,11 @@ void mem_cgroup_lru_del_list(struct page *page, enum lru_list lru)
                return;
 
        pc = lookup_page_cgroup(page);
-       /*
-        * root_mem_cgroup babysits uncharged LRU pages, but
-        * PageCgroupUsed is cleared when the page is about to get
-        * freed.  PageCgroupAcctLRU remembers whether the
-        * LRU-accounting happened against pc->mem_cgroup or
-        * root_mem_cgroup.
-        */
-       if (TestClearPageCgroupAcctLRU(pc)) {
-               VM_BUG_ON(!pc->mem_cgroup);
-               memcg = pc->mem_cgroup;
-       } else
-               memcg = root_mem_cgroup;
+       memcg = pc->mem_cgroup;
+       VM_BUG_ON(!memcg);
        mz = page_cgroup_zoneinfo(memcg, page);
        /* huge page split is done under lru_lock. so, we have no races. */
+       VM_BUG_ON(MEM_CGROUP_ZSTAT(mz, lru) < (1 << compound_order(page)));
        MEM_CGROUP_ZSTAT(mz, lru) -= 1 << compound_order(page);
 }
 
@@ -1149,86 +1104,6 @@ struct lruvec *mem_cgroup_lru_move_lists(struct zone *zone,
        return mem_cgroup_lru_add_list(zone, page, to);
 }
 
-/*
- * At handling SwapCache and other FUSE stuff, pc->mem_cgroup may be changed
- * while it's linked to lru because the page may be reused after it's fully
- * uncharged. To handle that, unlink page_cgroup from LRU when charge it again.
- * It's done under lock_page and expected that zone->lru_lock isnever held.
- */
-static void mem_cgroup_lru_del_before_commit(struct page *page)
-{
-       enum lru_list lru;
-       unsigned long flags;
-       struct zone *zone = page_zone(page);
-       struct page_cgroup *pc = lookup_page_cgroup(page);
-
-       /*
-        * Doing this check without taking ->lru_lock seems wrong but this
-        * is safe. Because if page_cgroup's USED bit is unset, the page
-        * will not be added to any memcg's LRU. If page_cgroup's USED bit is
-        * set, the commit after this will fail, anyway.
-        * This all charge/uncharge is done under some mutual execustion.
-        * So, we don't need to taking care of changes in USED bit.
-        */
-       if (likely(!PageLRU(page)))
-               return;
-
-       spin_lock_irqsave(&zone->lru_lock, flags);
-       lru = page_lru(page);
-       /*
-        * The uncharged page could still be registered to the LRU of
-        * the stale pc->mem_cgroup.
-        *
-        * As pc->mem_cgroup is about to get overwritten, the old LRU
-        * accounting needs to be taken care of.  Let root_mem_cgroup
-        * babysit the page until the new memcg is responsible for it.
-        *
-        * The PCG_USED bit is guarded by lock_page() as the page is
-        * swapcache/pagecache.
-        */
-       if (PageLRU(page) && PageCgroupAcctLRU(pc) && !PageCgroupUsed(pc)) {
-               del_page_from_lru_list(zone, page, lru);
-               add_page_to_lru_list(zone, page, lru);
-       }
-       spin_unlock_irqrestore(&zone->lru_lock, flags);
-}
-
-static void mem_cgroup_lru_add_after_commit(struct page *page)
-{
-       enum lru_list lru;
-       unsigned long flags;
-       struct zone *zone = page_zone(page);
-       struct page_cgroup *pc = lookup_page_cgroup(page);
-       /*
-        * putback:                             charge:
-        * SetPageLRU                           SetPageCgroupUsed
-        * smp_mb                               smp_mb
-        * PageCgroupUsed && add to memcg LRU   PageLRU && add to memcg LRU
-        *
-        * Ensure that one of the two sides adds the page to the memcg
-        * LRU during a race.
-        */
-       smp_mb();
-       /* taking care of that the page is added to LRU while we commit it */
-       if (likely(!PageLRU(page)))
-               return;
-       spin_lock_irqsave(&zone->lru_lock, flags);
-       lru = page_lru(page);
-       /*
-        * If the page is not on the LRU, someone will soon put it
-        * there.  If it is, and also already accounted for on the
-        * memcg-side, it must be on the right lruvec as setting
-        * pc->mem_cgroup and PageCgroupUsed is properly ordered.
-        * Otherwise, root_mem_cgroup has been babysitting the page
-        * during the charge.  Move it to the new memcg now.
-        */
-       if (PageLRU(page) && !PageCgroupAcctLRU(pc)) {
-               del_page_from_lru_list(zone, page, lru);
-               add_page_to_lru_list(zone, page, lru);
-       }
-       spin_unlock_irqrestore(&zone->lru_lock, flags);
-}
-
 /*
  * Checks whether given mem is same or in the root_mem_cgroup's
  * hierarchy subtree
@@ -1251,10 +1126,21 @@ int task_in_mem_cgroup(struct task_struct *task, const struct mem_cgroup *memcg)
        struct task_struct *p;
 
        p = find_lock_task_mm(task);
-       if (!p)
-               return 0;
-       curr = try_get_mem_cgroup_from_mm(p->mm);
-       task_unlock(p);
+       if (p) {
+               curr = try_get_mem_cgroup_from_mm(p->mm);
+               task_unlock(p);
+       } else {
+               /*
+                * All threads may have already detached their mm's, but the oom
+                * killer still needs to detect if they have already been oom
+                * killed to prevent needlessly killing additional tasks.
+                */
+               task_lock(task);
+               curr = mem_cgroup_from_task(task);
+               if (curr)
+                       css_get(&curr->css);
+               task_unlock(task);
+       }
        if (!curr)
                return 0;
        /*
@@ -1973,7 +1859,7 @@ void mem_cgroup_update_page_stat(struct page *page,
        bool need_unlock = false;
        unsigned long uninitialized_var(flags);
 
-       if (unlikely(!pc))
+       if (mem_cgroup_disabled())
                return;
 
        rcu_read_lock();
@@ -2299,8 +2185,25 @@ static int mem_cgroup_do_charge(struct mem_cgroup *memcg, gfp_t gfp_mask,
 }
 
 /*
- * Unlike exported interface, "oom" parameter is added. if oom==true,
- * oom-killer can be invoked.
+ * __mem_cgroup_try_charge() does
+ * 1. detect memcg to be charged against from passed *mm and *ptr,
+ * 2. update res_counter
+ * 3. call memory reclaim if necessary.
+ *
+ * In some special case, if the task is fatal, fatal_signal_pending() or
+ * has TIF_MEMDIE, this function returns -EINTR while writing root_mem_cgroup
+ * to *ptr. There are two reasons for this. 1: fatal threads should quit as soon
+ * as possible without any hazards. 2: all pages should have a valid
+ * pc->mem_cgroup. If mm is NULL and the caller doesn't pass a valid memcg
+ * pointer, that is treated as a charge to root_mem_cgroup.
+ *
+ * So __mem_cgroup_try_charge() will return
+ *  0       ...  on success, filling *ptr with a valid memcg pointer.
+ *  -ENOMEM ...  charge failure because of resource limits.
+ *  -EINTR  ...  if thread is fatal. *ptr is filled with root_mem_cgroup.
+ *
+ * Unlike the exported interface, an "oom" parameter is added. if oom==true,
+ * the oom-killer can be invoked.
  */
 static int __mem_cgroup_try_charge(struct mm_struct *mm,
                                   gfp_t gfp_mask,
@@ -2329,7 +2232,7 @@ static int __mem_cgroup_try_charge(struct mm_struct *mm,
         * set, if so charge the init_mm (happens for pagecache usage).
         */
        if (!*ptr && !mm)
-               goto bypass;
+               *ptr = root_mem_cgroup;
 again:
        if (*ptr) { /* css should be a valid one */
                memcg = *ptr;
@@ -2355,7 +2258,9 @@ again:
                 * task-struct. So, mm->owner can be NULL.
                 */
                memcg = mem_cgroup_from_task(p);
-               if (!memcg || mem_cgroup_is_root(memcg)) {
+               if (!memcg)
+                       memcg = root_mem_cgroup;
+               if (mem_cgroup_is_root(memcg)) {
                        rcu_read_unlock();
                        goto done;
                }
@@ -2430,8 +2335,8 @@ nomem:
        *ptr = NULL;
        return -ENOMEM;
 bypass:
-       *ptr = NULL;
-       return 0;
+       *ptr = root_mem_cgroup;
+       return -EINTR;
 }
 
 /*
@@ -2487,7 +2392,7 @@ struct mem_cgroup *try_get_mem_cgroup_from_page(struct page *page)
                        memcg = NULL;
        } else if (PageSwapCache(page)) {
                ent.val = page_private(page);
-               id = lookup_swap_cgroup(ent);
+               id = lookup_swap_cgroup_id(ent);
                rcu_read_lock();
                memcg = mem_cgroup_lookup(id);
                if (memcg && !css_tryget(&memcg->css))
@@ -2539,6 +2444,7 @@ static void __mem_cgroup_commit_charge(struct mem_cgroup *memcg,
 
        mem_cgroup_charge_statistics(memcg, PageCgroupCache(pc), nr_pages);
        unlock_page_cgroup(pc);
+       WARN_ON_ONCE(PageLRU(page));
        /*
         * "charge_statistics" updated event counter. Then, check it.
         * Insert ancestor (and ancestor's ancestors), to softlimit RB-tree.
@@ -2550,7 +2456,7 @@ static void __mem_cgroup_commit_charge(struct mem_cgroup *memcg,
 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
 
 #define PCGF_NOCOPY_AT_SPLIT ((1 << PCG_LOCK) | (1 << PCG_MOVE_LOCK) |\
-                       (1 << PCG_ACCT_LRU) | (1 << PCG_MIGRATION))
+                       (1 << PCG_MIGRATION))
 /*
  * Because tail pages are not marked as "used", set it. We're under
  * zone->lru_lock, 'splitting on pmd' and compound_lock.
@@ -2569,25 +2475,10 @@ void mem_cgroup_split_huge_fixup(struct page *head)
                pc = head_pc + i;
                pc->mem_cgroup = head_pc->mem_cgroup;
                smp_wmb();/* see __commit_charge() */
-               /*
-                * LRU flags cannot be copied because we need to add tail
-                * page to LRU by generic call and our hooks will be called.
-                */
                pc->flags = head_pc->flags & ~PCGF_NOCOPY_AT_SPLIT;
        }
-
-       if (PageCgroupAcctLRU(head_pc)) {
-               enum lru_list lru;
-               struct mem_cgroup_per_zone *mz;
-               /*
-                * We hold lru_lock, then, reduce counter directly.
-                */
-               lru = page_lru(head);
-               mz = page_cgroup_zoneinfo(head_pc->mem_cgroup, head);
-               MEM_CGROUP_ZSTAT(mz, lru) -= HPAGE_PMD_NR - 1;
-       }
 }
-#endif
+#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
 
 /**
  * mem_cgroup_move_account - move account of the page
@@ -2702,7 +2593,7 @@ static int mem_cgroup_move_parent(struct page *page,
 
        parent = mem_cgroup_from_cont(pcg);
        ret = __mem_cgroup_try_charge(NULL, gfp_mask, nr_pages, &parent, false);
-       if (ret || !parent)
+       if (ret)
                goto put_back;
 
        if (nr_pages > 1)
@@ -2748,12 +2639,9 @@ static int mem_cgroup_charge_common(struct page *page, struct mm_struct *mm,
        }
 
        pc = lookup_page_cgroup(page);
-       BUG_ON(!pc); /* XXX: remove this and move pc lookup into commit */
-
        ret = __mem_cgroup_try_charge(mm, gfp_mask, nr_pages, &memcg, oom);
-       if (ret || !memcg)
+       if (ret == -ENOMEM)
                return ret;
-
        __mem_cgroup_commit_charge(memcg, page, nr_pages, pc, ctype);
        return 0;
 }
@@ -2763,19 +2651,11 @@ int mem_cgroup_newpage_charge(struct page *page,
 {
        if (mem_cgroup_disabled())
                return 0;
-       /*
-        * If already mapped, we don't have to account.
-        * If page cache, page->mapping has address_space.
-        * But page->mapping may have out-of-use anon_vma pointer,
-        * detecit it by PageAnon() check. newly-mapped-anon's page->mapping
-        * is NULL.
-        */
-       if (page_mapped(page) || (page->mapping && !PageAnon(page)))
-               return 0;
-       if (unlikely(!mm))
-               mm = &init_mm;
+       VM_BUG_ON(page_mapped(page));
+       VM_BUG_ON(page->mapping && !PageAnon(page));
+       VM_BUG_ON(!mm);
        return mem_cgroup_charge_common(page, mm, gfp_mask,
-                               MEM_CGROUP_CHARGE_TYPE_MAPPED);
+                                       MEM_CGROUP_CHARGE_TYPE_MAPPED);
 }
 
 static void
@@ -2787,14 +2667,27 @@ __mem_cgroup_commit_charge_lrucare(struct page *page, struct mem_cgroup *memcg,
                                        enum charge_type ctype)
 {
        struct page_cgroup *pc = lookup_page_cgroup(page);
+       struct zone *zone = page_zone(page);
+       unsigned long flags;
+       bool removed = false;
+
        /*
         * In some case, SwapCache, FUSE(splice_buf->radixtree), the page
         * is already on LRU. It means the page may on some other page_cgroup's
         * LRU. Take care of it.
         */
-       mem_cgroup_lru_del_before_commit(page);
+       spin_lock_irqsave(&zone->lru_lock, flags);
+       if (PageLRU(page)) {
+               del_page_from_lru_list(zone, page, page_lru(page));
+               ClearPageLRU(page);
+               removed = true;
+       }
        __mem_cgroup_commit_charge(memcg, page, 1, pc, ctype);
-       mem_cgroup_lru_add_after_commit(page);
+       if (removed) {
+               add_page_to_lru_list(zone, page, page_lru(page));
+               SetPageLRU(page);
+       }
+       spin_unlock_irqrestore(&zone->lru_lock, flags);
        return;
 }
 
@@ -2802,6 +2695,7 @@ int mem_cgroup_cache_charge(struct page *page, struct mm_struct *mm,
                                gfp_t gfp_mask)
 {
        struct mem_cgroup *memcg = NULL;
+       enum charge_type type = MEM_CGROUP_CHARGE_TYPE_CACHE;
        int ret;
 
        if (mem_cgroup_disabled())
@@ -2811,31 +2705,16 @@ int mem_cgroup_cache_charge(struct page *page, struct mm_struct *mm,
 
        if (unlikely(!mm))
                mm = &init_mm;
+       if (!page_is_file_cache(page))
+               type = MEM_CGROUP_CHARGE_TYPE_SHMEM;
 
-       if (page_is_file_cache(page)) {
-               ret = __mem_cgroup_try_charge(mm, gfp_mask, 1, &memcg, true);
-               if (ret || !memcg)
-                       return ret;
-
-               /*
-                * FUSE reuses pages without going through the final
-                * put that would remove them from the LRU list, make
-                * sure that they get relinked properly.
-                */
-               __mem_cgroup_commit_charge_lrucare(page, memcg,
-                                       MEM_CGROUP_CHARGE_TYPE_CACHE);
-               return ret;
-       }
-       /* shmem */
-       if (PageSwapCache(page)) {
+       if (!PageSwapCache(page))
+               ret = mem_cgroup_charge_common(page, mm, gfp_mask, type);
+       else { /* page is swapcache/shmem */
                ret = mem_cgroup_try_charge_swapin(mm, page, gfp_mask, &memcg);
                if (!ret)
-                       __mem_cgroup_commit_charge_swapin(page, memcg,
-                                       MEM_CGROUP_CHARGE_TYPE_SHMEM);
-       } else
-               ret = mem_cgroup_charge_common(page, mm, gfp_mask,
-                                       MEM_CGROUP_CHARGE_TYPE_SHMEM);
-
+                       __mem_cgroup_commit_charge_swapin(page, memcg, type);
+       }
        return ret;
 }
 
@@ -2847,12 +2726,12 @@ int mem_cgroup_cache_charge(struct page *page, struct mm_struct *mm,
  */
 int mem_cgroup_try_charge_swapin(struct mm_struct *mm,
                                 struct page *page,
-                                gfp_t mask, struct mem_cgroup **ptr)
+                                gfp_t mask, struct mem_cgroup **memcgp)
 {
        struct mem_cgroup *memcg;
        int ret;
 
-       *ptr = NULL;
+       *memcgp = NULL;
 
        if (mem_cgroup_disabled())
                return 0;
@@ -2870,27 +2749,32 @@ int mem_cgroup_try_charge_swapin(struct mm_struct *mm,
        memcg = try_get_mem_cgroup_from_page(page);
        if (!memcg)
                goto charge_cur_mm;
-       *ptr = memcg;
-       ret = __mem_cgroup_try_charge(NULL, mask, 1, ptr, true);
+       *memcgp = memcg;
+       ret = __mem_cgroup_try_charge(NULL, mask, 1, memcgp, true);
        css_put(&memcg->css);
+       if (ret == -EINTR)
+               ret = 0;
        return ret;
 charge_cur_mm:
        if (unlikely(!mm))
                mm = &init_mm;
-       return __mem_cgroup_try_charge(mm, mask, 1, ptr, true);
+       ret = __mem_cgroup_try_charge(mm, mask, 1, memcgp, true);
+       if (ret == -EINTR)
+               ret = 0;
+       return ret;
 }
 
 static void
-__mem_cgroup_commit_charge_swapin(struct page *page, struct mem_cgroup *ptr,
+__mem_cgroup_commit_charge_swapin(struct page *page, struct mem_cgroup *memcg,
                                        enum charge_type ctype)
 {
        if (mem_cgroup_disabled())
                return;
-       if (!ptr)
+       if (!memcg)
                return;
-       cgroup_exclude_rmdir(&ptr->css);
+       cgroup_exclude_rmdir(&memcg->css);
 
-       __mem_cgroup_commit_charge_lrucare(page, ptr, ctype);
+       __mem_cgroup_commit_charge_lrucare(page, memcg, ctype);
        /*
         * Now swap is on-memory. This means this page may be
         * counted both as mem and swap....double count.
@@ -2900,21 +2784,22 @@ __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)};
+               struct mem_cgroup *swap_memcg;
                unsigned short id;
-               struct mem_cgroup *memcg;
 
                id = swap_cgroup_record(ent, 0);
                rcu_read_lock();
-               memcg = mem_cgroup_lookup(id);
-               if (memcg) {
+               swap_memcg = mem_cgroup_lookup(id);
+               if (swap_memcg) {
                        /*
                         * This recorded memcg can be obsolete one. So, avoid
                         * calling css_tryget
                         */
-                       if (!mem_cgroup_is_root(memcg))
-                               res_counter_uncharge(&memcg->memsw, PAGE_SIZE);
-                       mem_cgroup_swap_statistics(memcg, false);
-                       mem_cgroup_put(memcg);
+                       if (!mem_cgroup_is_root(swap_memcg))
+                               res_counter_uncharge(&swap_memcg->memsw,
+                                                    PAGE_SIZE);
+                       mem_cgroup_swap_statistics(swap_memcg, false);
+                       mem_cgroup_put(swap_memcg);
                }
                rcu_read_unlock();
        }
@@ -2923,13 +2808,14 @@ __mem_cgroup_commit_charge_swapin(struct page *page, struct mem_cgroup *ptr,
         * 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);
+       cgroup_release_and_wakeup_rmdir(&memcg->css);
 }
 
-void mem_cgroup_commit_charge_swapin(struct page *page, struct mem_cgroup *ptr)
+void mem_cgroup_commit_charge_swapin(struct page *page,
+                                    struct mem_cgroup *memcg)
 {
-       __mem_cgroup_commit_charge_swapin(page, ptr,
-                                       MEM_CGROUP_CHARGE_TYPE_MAPPED);
+       __mem_cgroup_commit_charge_swapin(page, memcg,
+                                         MEM_CGROUP_CHARGE_TYPE_MAPPED);
 }
 
 void mem_cgroup_cancel_charge_swapin(struct mem_cgroup *memcg)
@@ -3019,7 +2905,7 @@ __mem_cgroup_uncharge_common(struct page *page, enum charge_type ctype)
         * Check if our page_cgroup is valid
         */
        pc = lookup_page_cgroup(page);
-       if (unlikely(!pc || !PageCgroupUsed(pc)))
+       if (unlikely(!PageCgroupUsed(pc)))
                return NULL;
 
        lock_page_cgroup(pc);
@@ -3082,8 +2968,7 @@ void mem_cgroup_uncharge_page(struct page *page)
        /* early check. */
        if (page_mapped(page))
                return;
-       if (page->mapping && !PageAnon(page))
-               return;
+       VM_BUG_ON(page->mapping && !PageAnon(page));
        __mem_cgroup_uncharge_common(page, MEM_CGROUP_CHARGE_TYPE_MAPPED);
 }
 
@@ -3141,6 +3026,23 @@ void mem_cgroup_uncharge_end(void)
        batch->memcg = NULL;
 }
 
+/*
+ * A function for resetting pc->mem_cgroup for newly allocated pages.
+ * This function should be called if the newpage will be added to LRU
+ * before start accounting.
+ */
+void mem_cgroup_reset_owner(struct page *newpage)
+{
+       struct page_cgroup *pc;
+
+       if (mem_cgroup_disabled())
+               return;
+
+       pc = lookup_page_cgroup(newpage);
+       VM_BUG_ON(PageCgroupUsed(pc));
+       pc->mem_cgroup = root_mem_cgroup;
+}
+
 #ifdef CONFIG_SWAP
 /*
  * called after __delete_from_swap_cache() and drop "page" account.
@@ -3258,14 +3160,14 @@ static inline int mem_cgroup_move_swap_account(swp_entry_t entry,
  * page belongs to.
  */
 int mem_cgroup_prepare_migration(struct page *page,
-       struct page *newpage, struct mem_cgroup **ptr, gfp_t gfp_mask)
+       struct page *newpage, struct mem_cgroup **memcgp, gfp_t gfp_mask)
 {
        struct mem_cgroup *memcg = NULL;
        struct page_cgroup *pc;
        enum charge_type ctype;
        int ret = 0;
 
-       *ptr = NULL;
+       *memcgp = NULL;
 
        VM_BUG_ON(PageTransHuge(page));
        if (mem_cgroup_disabled())
@@ -3316,10 +3218,10 @@ int mem_cgroup_prepare_migration(struct page *page,
        if (!memcg)
                return 0;
 
-       *ptr = memcg;
-       ret = __mem_cgroup_try_charge(NULL, gfp_mask, 1, ptr, false);
+       *memcgp = memcg;
+       ret = __mem_cgroup_try_charge(NULL, gfp_mask, 1, memcgp, false);
        css_put(&memcg->css);/* drop extra refcnt */
-       if (ret || *ptr == NULL) {
+       if (ret) {
                if (PageAnon(page)) {
                        lock_page_cgroup(pc);
                        ClearPageCgroupMigration(pc);
@@ -3329,6 +3231,7 @@ int mem_cgroup_prepare_migration(struct page *page,
                         */
                        mem_cgroup_uncharge_page(page);
                }
+               /* we'll need to revisit this error code (we have -EINTR) */
                return -ENOMEM;
        }
        /*
@@ -3344,7 +3247,7 @@ int mem_cgroup_prepare_migration(struct page *page,
                ctype = MEM_CGROUP_CHARGE_TYPE_CACHE;
        else
                ctype = MEM_CGROUP_CHARGE_TYPE_SHMEM;
-       __mem_cgroup_commit_charge(memcg, page, 1, pc, ctype);
+       __mem_cgroup_commit_charge(memcg, newpage, 1, pc, ctype);
        return ret;
 }
 
@@ -3407,9 +3310,7 @@ void mem_cgroup_replace_page_cache(struct page *oldpage,
 {
        struct mem_cgroup *memcg;
        struct page_cgroup *pc;
-       struct zone *zone;
        enum charge_type type = MEM_CGROUP_CHARGE_TYPE_CACHE;
-       unsigned long flags;
 
        if (mem_cgroup_disabled())
                return;
@@ -3425,20 +3326,12 @@ void mem_cgroup_replace_page_cache(struct page *oldpage,
        if (PageSwapBacked(oldpage))
                type = MEM_CGROUP_CHARGE_TYPE_SHMEM;
 
-       zone = page_zone(newpage);
-       pc = lookup_page_cgroup(newpage);
        /*
         * Even if newpage->mapping was NULL before starting replacement,
         * the newpage may be on LRU(or pagevec for LRU) already. We lock
         * LRU while we overwrite pc->mem_cgroup.
         */
-       spin_lock_irqsave(&zone->lru_lock, flags);
-       if (PageLRU(newpage))
-               del_page_from_lru_list(zone, newpage, page_lru(newpage));
-       __mem_cgroup_commit_charge(memcg, newpage, 1, pc, type);
-       if (PageLRU(newpage))
-               add_page_to_lru_list(zone, newpage, page_lru(newpage));
-       spin_unlock_irqrestore(&zone->lru_lock, flags);
+       __mem_cgroup_commit_charge_lrucare(newpage, memcg, type);
 }
 
 #ifdef CONFIG_DEBUG_VM
@@ -3447,6 +3340,11 @@ static struct page_cgroup *lookup_page_cgroup_used(struct page *page)
        struct page_cgroup *pc;
 
        pc = lookup_page_cgroup(page);
+       /*
+        * Can be NULL while feeding pages into the page allocator for
+        * the first time, i.e. during boot or memory hotplug;
+        * or when mem_cgroup_disabled().
+        */
        if (likely(pc) && PageCgroupUsed(pc))
                return pc;
        return NULL;
@@ -3466,23 +3364,8 @@ void mem_cgroup_print_bad_page(struct page *page)
 
        pc = lookup_page_cgroup_used(page);
        if (pc) {
-               int ret = -1;
-               char *path;
-
-               printk(KERN_ALERT "pc:%p pc->flags:%lx pc->mem_cgroup:%p",
+               printk(KERN_ALERT "pc:%p pc->flags:%lx pc->mem_cgroup:%p\n",
                       pc, pc->flags, pc->mem_cgroup);
-
-               path = kmalloc(PATH_MAX, GFP_KERNEL);
-               if (path) {
-                       rcu_read_lock();
-                       ret = cgroup_path(pc->mem_cgroup->css.cgroup,
-                                                       path, PATH_MAX);
-                       rcu_read_unlock();
-               }
-
-               printk(KERN_CONT "(%s)\n",
-                               (ret < 0) ? "cannot get the path" : path);
-               kfree(path);
        }
 }
 #endif
@@ -3753,7 +3636,7 @@ static int mem_cgroup_force_empty_list(struct mem_cgroup *memcg,
                pc = lookup_page_cgroup(page);
 
                ret = mem_cgroup_move_parent(page, pc, memcg, GFP_KERNEL);
-               if (ret == -ENOMEM)
+               if (ret == -ENOMEM || ret == -EINTR)
                        break;
 
                if (ret == -EBUSY || ret == -EINVAL) {
@@ -4912,7 +4795,7 @@ static void __mem_cgroup_free(struct mem_cgroup *memcg)
        mem_cgroup_remove_from_trees(memcg);
        free_css_id(&mem_cgroup_subsys, &memcg->css);
 
-       for_each_node_state(node, N_POSSIBLE)
+       for_each_node(node)
                free_mem_cgroup_per_zone_info(memcg, node);
 
        free_percpu(memcg->stat);
@@ -4971,13 +4854,13 @@ static int mem_cgroup_soft_limit_tree_init(void)
        struct mem_cgroup_tree_per_zone *rtpz;
        int tmp, node, zone;
 
-       for_each_node_state(node, N_POSSIBLE) {
+       for_each_node(node) {
                tmp = node;
                if (!node_state(node, N_NORMAL_MEMORY))
                        tmp = -1;
                rtpn = kzalloc_node(sizeof(*rtpn), GFP_KERNEL, tmp);
                if (!rtpn)
-                       return 1;
+                       goto err_cleanup;
 
                soft_limit_tree.rb_tree_per_node[node] = rtpn;
 
@@ -4988,6 +4871,16 @@ static int mem_cgroup_soft_limit_tree_init(void)
                }
        }
        return 0;
+
+err_cleanup:
+       for_each_node(node) {
+               if (!soft_limit_tree.rb_tree_per_node[node])
+                       break;
+               kfree(soft_limit_tree.rb_tree_per_node[node]);
+               soft_limit_tree.rb_tree_per_node[node] = NULL;
+       }
+       return 1;
+
 }
 
 static struct cgroup_subsys_state * __ref
@@ -5001,7 +4894,7 @@ mem_cgroup_create(struct cgroup_subsys *ss, struct cgroup *cont)
        if (!memcg)
                return ERR_PTR(error);
 
-       for_each_node_state(node, N_POSSIBLE)
+       for_each_node(node)
                if (alloc_mem_cgroup_per_zone_info(memcg, node))
                        goto free_out;
 
@@ -5134,9 +5027,9 @@ one_by_one:
                }
                ret = __mem_cgroup_try_charge(NULL,
                                        GFP_KERNEL, 1, &memcg, false);
-               if (ret || !memcg)
+               if (ret)
                        /* mem_cgroup_clear_mc() will do uncharge later */
-                       return -ENOMEM;
+                       return ret;
                mc.precharge++;
        }
        return ret;
@@ -5281,7 +5174,7 @@ static int is_target_pte_for_mc(struct vm_area_struct *vma,
        }
        /* There is a swap entry and a page doesn't exist or isn't charged */
        if (ent.val && !ret &&
-                       css_id(&mc.from->css) == lookup_swap_cgroup(ent)) {
+                       css_id(&mc.from->css) == lookup_swap_cgroup_id(ent)) {
                ret = MC_TARGET_SWAP;
                if (target)
                        target->ent = ent;