Merge tag 'arc-fixes-for-3.12' of git://git.kernel.org/pub/scm/linux/kernel/git/vgupt...
[pandora-kernel.git] / mm / memcontrol.c
index 2c71f24..1c52ddb 100644 (file)
@@ -39,6 +39,7 @@
 #include <linux/limits.h>
 #include <linux/export.h>
 #include <linux/mutex.h>
+#include <linux/rbtree.h>
 #include <linux/slab.h>
 #include <linux/swap.h>
 #include <linux/swapops.h>
@@ -84,26 +85,12 @@ static int really_do_swap_account __initdata = 0;
 #endif
 
 
-/*
- * Statistics for memory cgroup.
- */
-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 anon rss */
-       MEM_CGROUP_STAT_RSS_HUGE,       /* # of pages charged as anon huge */
-       MEM_CGROUP_STAT_FILE_MAPPED,    /* # of pages charged as file rss */
-       MEM_CGROUP_STAT_SWAP,           /* # of pages, swapped out */
-       MEM_CGROUP_STAT_NSTATS,
-};
-
 static const char * const mem_cgroup_stat_names[] = {
        "cache",
        "rss",
        "rss_huge",
        "mapped_file",
+       "writeback",
        "swap",
 };
 
@@ -174,6 +161,10 @@ struct mem_cgroup_per_zone {
 
        struct mem_cgroup_reclaim_iter reclaim_iter[DEF_PRIORITY + 1];
 
+       struct rb_node          tree_node;      /* RB tree node */
+       unsigned long long      usage_in_excess;/* Set to the value by which */
+                                               /* the soft limit is exceeded*/
+       bool                    on_tree;
        struct mem_cgroup       *memcg;         /* Back pointer, we cannot */
                                                /* use container_of        */
 };
@@ -182,6 +173,26 @@ struct mem_cgroup_per_node {
        struct mem_cgroup_per_zone zoneinfo[MAX_NR_ZONES];
 };
 
+/*
+ * Cgroups above their limits are maintained in a RB-Tree, independent of
+ * their hierarchy representation
+ */
+
+struct mem_cgroup_tree_per_zone {
+       struct rb_root rb_root;
+       spinlock_t lock;
+};
+
+struct mem_cgroup_tree_per_node {
+       struct mem_cgroup_tree_per_zone rb_tree_per_zone[MAX_NR_ZONES];
+};
+
+struct mem_cgroup_tree {
+       struct mem_cgroup_tree_per_node *rb_tree_per_node[MAX_NUMNODES];
+};
+
+static struct mem_cgroup_tree soft_limit_tree __read_mostly;
+
 struct mem_cgroup_threshold {
        struct eventfd_ctx *eventfd;
        u64 threshold;
@@ -317,22 +328,6 @@ struct mem_cgroup {
        atomic_t        numainfo_events;
        atomic_t        numainfo_updating;
 #endif
-       /*
-        * Protects soft_contributed transitions.
-        * See mem_cgroup_update_soft_limit
-        */
-       spinlock_t soft_lock;
-
-       /*
-        * If true then this group has increased parents' children_in_excess
-        * when it got over the soft limit.
-        * When a group falls bellow the soft limit, parents' children_in_excess
-        * is decreased and soft_contributed changed to false.
-        */
-       bool soft_contributed;
-
-       /* Number of children that are in soft limit excess */
-       atomic_t children_in_excess;
 
        struct mem_cgroup_per_node *nodeinfo[0];
        /* WARNING: nodeinfo must be the last member here */
@@ -436,6 +431,7 @@ static bool move_file(void)
  * limit reclaim to prevent infinite loops, if they ever occur.
  */
 #define        MEM_CGROUP_MAX_RECLAIM_LOOPS            100
+#define        MEM_CGROUP_MAX_SOFT_LIMIT_RECLAIM_LOOPS 2
 
 enum charge_type {
        MEM_CGROUP_CHARGE_TYPE_CACHE = 0,
@@ -662,6 +658,164 @@ page_cgroup_zoneinfo(struct mem_cgroup *memcg, struct page *page)
        return mem_cgroup_zoneinfo(memcg, nid, zid);
 }
 
+static struct mem_cgroup_tree_per_zone *
+soft_limit_tree_node_zone(int nid, int zid)
+{
+       return &soft_limit_tree.rb_tree_per_node[nid]->rb_tree_per_zone[zid];
+}
+
+static struct mem_cgroup_tree_per_zone *
+soft_limit_tree_from_page(struct page *page)
+{
+       int nid = page_to_nid(page);
+       int zid = page_zonenum(page);
+
+       return &soft_limit_tree.rb_tree_per_node[nid]->rb_tree_per_zone[zid];
+}
+
+static void
+__mem_cgroup_insert_exceeded(struct mem_cgroup *memcg,
+                               struct mem_cgroup_per_zone *mz,
+                               struct mem_cgroup_tree_per_zone *mctz,
+                               unsigned long long new_usage_in_excess)
+{
+       struct rb_node **p = &mctz->rb_root.rb_node;
+       struct rb_node *parent = NULL;
+       struct mem_cgroup_per_zone *mz_node;
+
+       if (mz->on_tree)
+               return;
+
+       mz->usage_in_excess = new_usage_in_excess;
+       if (!mz->usage_in_excess)
+               return;
+       while (*p) {
+               parent = *p;
+               mz_node = rb_entry(parent, struct mem_cgroup_per_zone,
+                                       tree_node);
+               if (mz->usage_in_excess < mz_node->usage_in_excess)
+                       p = &(*p)->rb_left;
+               /*
+                * We can't avoid mem cgroups that are over their soft
+                * limit by the same amount
+                */
+               else if (mz->usage_in_excess >= mz_node->usage_in_excess)
+                       p = &(*p)->rb_right;
+       }
+       rb_link_node(&mz->tree_node, parent, p);
+       rb_insert_color(&mz->tree_node, &mctz->rb_root);
+       mz->on_tree = true;
+}
+
+static void
+__mem_cgroup_remove_exceeded(struct mem_cgroup *memcg,
+                               struct mem_cgroup_per_zone *mz,
+                               struct mem_cgroup_tree_per_zone *mctz)
+{
+       if (!mz->on_tree)
+               return;
+       rb_erase(&mz->tree_node, &mctz->rb_root);
+       mz->on_tree = false;
+}
+
+static void
+mem_cgroup_remove_exceeded(struct mem_cgroup *memcg,
+                               struct mem_cgroup_per_zone *mz,
+                               struct mem_cgroup_tree_per_zone *mctz)
+{
+       spin_lock(&mctz->lock);
+       __mem_cgroup_remove_exceeded(memcg, mz, mctz);
+       spin_unlock(&mctz->lock);
+}
+
+
+static void mem_cgroup_update_tree(struct mem_cgroup *memcg, struct page *page)
+{
+       unsigned long long excess;
+       struct mem_cgroup_per_zone *mz;
+       struct mem_cgroup_tree_per_zone *mctz;
+       int nid = page_to_nid(page);
+       int zid = page_zonenum(page);
+       mctz = soft_limit_tree_from_page(page);
+
+       /*
+        * Necessary to update all ancestors when hierarchy is used.
+        * because their event counter is not touched.
+        */
+       for (; memcg; memcg = parent_mem_cgroup(memcg)) {
+               mz = mem_cgroup_zoneinfo(memcg, nid, zid);
+               excess = res_counter_soft_limit_excess(&memcg->res);
+               /*
+                * We have to update the tree if mz is on RB-tree or
+                * mem is over its softlimit.
+                */
+               if (excess || mz->on_tree) {
+                       spin_lock(&mctz->lock);
+                       /* if on-tree, remove it */
+                       if (mz->on_tree)
+                               __mem_cgroup_remove_exceeded(memcg, mz, mctz);
+                       /*
+                        * Insert again. mz->usage_in_excess will be updated.
+                        * If excess is 0, no tree ops.
+                        */
+                       __mem_cgroup_insert_exceeded(memcg, mz, mctz, excess);
+                       spin_unlock(&mctz->lock);
+               }
+       }
+}
+
+static void mem_cgroup_remove_from_trees(struct mem_cgroup *memcg)
+{
+       int node, zone;
+       struct mem_cgroup_per_zone *mz;
+       struct mem_cgroup_tree_per_zone *mctz;
+
+       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);
+                       mem_cgroup_remove_exceeded(memcg, mz, mctz);
+               }
+       }
+}
+
+static struct mem_cgroup_per_zone *
+__mem_cgroup_largest_soft_limit_node(struct mem_cgroup_tree_per_zone *mctz)
+{
+       struct rb_node *rightmost = NULL;
+       struct mem_cgroup_per_zone *mz;
+
+retry:
+       mz = NULL;
+       rightmost = rb_last(&mctz->rb_root);
+       if (!rightmost)
+               goto done;              /* Nothing to reclaim from */
+
+       mz = rb_entry(rightmost, struct mem_cgroup_per_zone, tree_node);
+       /*
+        * Remove the node now but someone else can add it back,
+        * we will to add it back at the end of reclaim to its correct
+        * position in the tree.
+        */
+       __mem_cgroup_remove_exceeded(mz->memcg, mz, mctz);
+       if (!res_counter_soft_limit_excess(&mz->memcg->res) ||
+               !css_tryget(&mz->memcg->css))
+               goto retry;
+done:
+       return mz;
+}
+
+static struct mem_cgroup_per_zone *
+mem_cgroup_largest_soft_limit_node(struct mem_cgroup_tree_per_zone *mctz)
+{
+       struct mem_cgroup_per_zone *mz;
+
+       spin_lock(&mctz->lock);
+       mz = __mem_cgroup_largest_soft_limit_node(mctz);
+       spin_unlock(&mctz->lock);
+       return mz;
+}
+
 /*
  * Implementation Note: reading percpu statistics for memcg.
  *
@@ -835,48 +989,6 @@ static bool mem_cgroup_event_ratelimit(struct mem_cgroup *memcg,
        return false;
 }
 
-/*
- * Called from rate-limited memcg_check_events when enough
- * MEM_CGROUP_TARGET_SOFTLIMIT events are accumulated and it makes sure
- * that all the parents up the hierarchy will be notified that this group
- * is in excess or that it is not in excess anymore. mmecg->soft_contributed
- * makes the transition a single action whenever the state flips from one to
- * the other.
- */
-static void mem_cgroup_update_soft_limit(struct mem_cgroup *memcg)
-{
-       unsigned long long excess = res_counter_soft_limit_excess(&memcg->res);
-       struct mem_cgroup *parent = memcg;
-       int delta = 0;
-
-       spin_lock(&memcg->soft_lock);
-       if (excess) {
-               if (!memcg->soft_contributed) {
-                       delta = 1;
-                       memcg->soft_contributed = true;
-               }
-       } else {
-               if (memcg->soft_contributed) {
-                       delta = -1;
-                       memcg->soft_contributed = false;
-               }
-       }
-
-       /*
-        * Necessary to update all ancestors when hierarchy is used
-        * because their event counter is not touched.
-        * We track children even outside the hierarchy for the root
-        * cgroup because tree walk starting at root should visit
-        * all cgroups and we want to prevent from pointless tree
-        * walk if no children is below the limit.
-        */
-       while (delta && (parent = parent_mem_cgroup(parent)))
-               atomic_add(delta, &parent->children_in_excess);
-       if (memcg != root_mem_cgroup && !root_mem_cgroup->use_hierarchy)
-               atomic_add(delta, &root_mem_cgroup->children_in_excess);
-       spin_unlock(&memcg->soft_lock);
-}
-
 /*
  * Check events in order.
  *
@@ -900,7 +1012,7 @@ static void memcg_check_events(struct mem_cgroup *memcg, struct page *page)
 
                mem_cgroup_threshold(memcg);
                if (unlikely(do_softlimit))
-                       mem_cgroup_update_soft_limit(memcg);
+                       mem_cgroup_update_tree(memcg, page);
 #if MAX_NUMNODES > 1
                if (unlikely(do_numainfo))
                        atomic_inc(&memcg->numainfo_events);
@@ -943,15 +1055,6 @@ struct mem_cgroup *try_get_mem_cgroup_from_mm(struct mm_struct *mm)
        return memcg;
 }
 
-static enum mem_cgroup_filter_t
-mem_cgroup_filter(struct mem_cgroup *memcg, struct mem_cgroup *root,
-               mem_cgroup_iter_filter cond)
-{
-       if (!cond)
-               return VISIT;
-       return cond(memcg, root);
-}
-
 /*
  * Returns a next (in a pre-order walk) alive memcg (with elevated css
  * ref. count) or NULL if the whole root's subtree has been visited.
@@ -959,7 +1062,7 @@ mem_cgroup_filter(struct mem_cgroup *memcg, struct mem_cgroup *root,
  * helper function to be used by mem_cgroup_iter
  */
 static struct mem_cgroup *__mem_cgroup_iter_next(struct mem_cgroup *root,
-               struct mem_cgroup *last_visited, mem_cgroup_iter_filter cond)
+               struct mem_cgroup *last_visited)
 {
        struct cgroup_subsys_state *prev_css, *next_css;
 
@@ -977,31 +1080,11 @@ skip_node:
        if (next_css) {
                struct mem_cgroup *mem = mem_cgroup_from_css(next_css);
 
-               switch (mem_cgroup_filter(mem, root, cond)) {
-               case SKIP:
+               if (css_tryget(&mem->css))
+                       return mem;
+               else {
                        prev_css = next_css;
                        goto skip_node;
-               case SKIP_TREE:
-                       if (mem == root)
-                               return NULL;
-                       /*
-                        * css_rightmost_descendant is not an optimal way to
-                        * skip through a subtree (especially for imbalanced
-                        * trees leaning to right) but that's what we have right
-                        * now. More effective solution would be traversing
-                        * right-up for first non-NULL without calling
-                        * css_next_descendant_pre afterwards.
-                        */
-                       prev_css = css_rightmost_descendant(next_css);
-                       goto skip_node;
-               case VISIT:
-                       if (css_tryget(&mem->css))
-                               return mem;
-                       else {
-                               prev_css = next_css;
-                               goto skip_node;
-                       }
-                       break;
                }
        }
 
@@ -1065,7 +1148,6 @@ static void mem_cgroup_iter_update(struct mem_cgroup_reclaim_iter *iter,
  * @root: hierarchy root
  * @prev: previously returned memcg, NULL on first invocation
  * @reclaim: cookie for shared reclaim walks, NULL for full walks
- * @cond: filter for visited nodes, NULL for no filter
  *
  * Returns references to children of the hierarchy below @root, or
  * @root itself, or %NULL after a full round-trip.
@@ -1078,18 +1160,15 @@ static void mem_cgroup_iter_update(struct mem_cgroup_reclaim_iter *iter,
  * divide up the memcgs in the hierarchy among all concurrent
  * reclaimers operating on the same zone and priority.
  */
-struct mem_cgroup *mem_cgroup_iter_cond(struct mem_cgroup *root,
+struct mem_cgroup *mem_cgroup_iter(struct mem_cgroup *root,
                                   struct mem_cgroup *prev,
-                                  struct mem_cgroup_reclaim_cookie *reclaim,
-                                  mem_cgroup_iter_filter cond)
+                                  struct mem_cgroup_reclaim_cookie *reclaim)
 {
        struct mem_cgroup *memcg = NULL;
        struct mem_cgroup *last_visited = NULL;
 
-       if (mem_cgroup_disabled()) {
-               /* first call must return non-NULL, second return NULL */
-               return (struct mem_cgroup *)(unsigned long)!prev;
-       }
+       if (mem_cgroup_disabled())
+               return NULL;
 
        if (!root)
                root = root_mem_cgroup;
@@ -1100,9 +1179,7 @@ struct mem_cgroup *mem_cgroup_iter_cond(struct mem_cgroup *root,
        if (!root->use_hierarchy && root != root_mem_cgroup) {
                if (prev)
                        goto out_css_put;
-               if (mem_cgroup_filter(root, root, cond) == VISIT)
-                       return root;
-               return NULL;
+               return root;
        }
 
        rcu_read_lock();
@@ -1125,7 +1202,7 @@ struct mem_cgroup *mem_cgroup_iter_cond(struct mem_cgroup *root,
                        last_visited = mem_cgroup_iter_load(iter, root, &seq);
                }
 
-               memcg = __mem_cgroup_iter_next(root, last_visited, cond);
+               memcg = __mem_cgroup_iter_next(root, last_visited);
 
                if (reclaim) {
                        mem_cgroup_iter_update(iter, last_visited, memcg, seq);
@@ -1136,11 +1213,7 @@ struct mem_cgroup *mem_cgroup_iter_cond(struct mem_cgroup *root,
                                reclaim->generation = iter->generation;
                }
 
-               /*
-                * We have finished the whole tree walk or no group has been
-                * visited because filter told us to skip the root node.
-                */
-               if (!memcg && (prev || (cond && !last_visited)))
+               if (prev && !memcg)
                        goto out_unlock;
        }
 out_unlock:
@@ -1781,7 +1854,6 @@ static unsigned long mem_cgroup_reclaim(struct mem_cgroup *memcg,
        return total;
 }
 
-#if MAX_NUMNODES > 1
 /**
  * test_mem_cgroup_node_reclaimable
  * @memcg: the target memcg
@@ -1804,6 +1876,7 @@ static bool test_mem_cgroup_node_reclaimable(struct mem_cgroup *memcg,
        return false;
 
 }
+#if MAX_NUMNODES > 1
 
 /*
  * Always updating the nodemask is not very good - even if we have an empty
@@ -1871,50 +1944,104 @@ int mem_cgroup_select_victim_node(struct mem_cgroup *memcg)
        return node;
 }
 
+/*
+ * Check all nodes whether it contains reclaimable pages or not.
+ * For quick scan, we make use of scan_nodes. This will allow us to skip
+ * unused nodes. But scan_nodes is lazily updated and may not cotain
+ * enough new information. We need to do double check.
+ */
+static bool mem_cgroup_reclaimable(struct mem_cgroup *memcg, bool noswap)
+{
+       int nid;
+
+       /*
+        * quick check...making use of scan_node.
+        * We can skip unused nodes.
+        */
+       if (!nodes_empty(memcg->scan_nodes)) {
+               for (nid = first_node(memcg->scan_nodes);
+                    nid < MAX_NUMNODES;
+                    nid = next_node(nid, memcg->scan_nodes)) {
+
+                       if (test_mem_cgroup_node_reclaimable(memcg, nid, noswap))
+                               return true;
+               }
+       }
+       /*
+        * Check rest of nodes.
+        */
+       for_each_node_state(nid, N_MEMORY) {
+               if (node_isset(nid, memcg->scan_nodes))
+                       continue;
+               if (test_mem_cgroup_node_reclaimable(memcg, nid, noswap))
+                       return true;
+       }
+       return false;
+}
+
 #else
 int mem_cgroup_select_victim_node(struct mem_cgroup *memcg)
 {
        return 0;
 }
 
-#endif
-
-/*
- * A group is eligible for the soft limit reclaim under the given root
- * hierarchy if
- *     a) it is over its soft limit
- *     b) any parent up the hierarchy is over its soft limit
- *
- * If the given group doesn't have any children over the limit then it
- * doesn't make any sense to iterate its subtree.
- */
-enum mem_cgroup_filter_t
-mem_cgroup_soft_reclaim_eligible(struct mem_cgroup *memcg,
-               struct mem_cgroup *root)
+static bool mem_cgroup_reclaimable(struct mem_cgroup *memcg, bool noswap)
 {
-       struct mem_cgroup *parent;
-
-       if (!memcg)
-               memcg = root_mem_cgroup;
-       parent = memcg;
-
-       if (res_counter_soft_limit_excess(&memcg->res))
-               return VISIT;
+       return test_mem_cgroup_node_reclaimable(memcg, 0, noswap);
+}
+#endif
 
-       /*
-        * If any parent up to the root in the hierarchy is over its soft limit
-        * then we have to obey and reclaim from this group as well.
-        */
-       while ((parent = parent_mem_cgroup(parent))) {
-               if (res_counter_soft_limit_excess(&parent->res))
-                       return VISIT;
-               if (parent == root)
+static int mem_cgroup_soft_reclaim(struct mem_cgroup *root_memcg,
+                                  struct zone *zone,
+                                  gfp_t gfp_mask,
+                                  unsigned long *total_scanned)
+{
+       struct mem_cgroup *victim = NULL;
+       int total = 0;
+       int loop = 0;
+       unsigned long excess;
+       unsigned long nr_scanned;
+       struct mem_cgroup_reclaim_cookie reclaim = {
+               .zone = zone,
+               .priority = 0,
+       };
+
+       excess = res_counter_soft_limit_excess(&root_memcg->res) >> PAGE_SHIFT;
+
+       while (1) {
+               victim = mem_cgroup_iter(root_memcg, victim, &reclaim);
+               if (!victim) {
+                       loop++;
+                       if (loop >= 2) {
+                               /*
+                                * If we have not been able to reclaim
+                                * anything, it might because there are
+                                * no reclaimable pages under this hierarchy
+                                */
+                               if (!total)
+                                       break;
+                               /*
+                                * We want to do more targeted reclaim.
+                                * excess >> 2 is not to excessive so as to
+                                * reclaim too much, nor too less that we keep
+                                * coming back to reclaim from this cgroup
+                                */
+                               if (total >= (excess >> 2) ||
+                                       (loop > MEM_CGROUP_MAX_RECLAIM_LOOPS))
+                                       break;
+                       }
+                       continue;
+               }
+               if (!mem_cgroup_reclaimable(victim, false))
+                       continue;
+               total += mem_cgroup_shrink_node_zone(victim, gfp_mask, false,
+                                                    zone, &nr_scanned);
+               *total_scanned += nr_scanned;
+               if (!res_counter_soft_limit_excess(&root_memcg->res))
                        break;
        }
-
-       if (!atomic_read(&memcg->children_in_excess))
-               return SKIP_TREE;
-       return SKIP;
+       mem_cgroup_iter_break(root_memcg, victim);
+       return total;
 }
 
 static DEFINE_SPINLOCK(memcg_oom_lock);
@@ -2231,7 +2358,7 @@ void __mem_cgroup_end_update_page_stat(struct page *page, unsigned long *flags)
 }
 
 void mem_cgroup_update_page_stat(struct page *page,
-                                enum mem_cgroup_page_stat_item idx, int val)
+                                enum mem_cgroup_stat_index idx, int val)
 {
        struct mem_cgroup *memcg;
        struct page_cgroup *pc = lookup_page_cgroup(page);
@@ -2240,18 +2367,11 @@ void mem_cgroup_update_page_stat(struct page *page,
        if (mem_cgroup_disabled())
                return;
 
+       VM_BUG_ON(!rcu_read_lock_held());
        memcg = pc->mem_cgroup;
        if (unlikely(!memcg || !PageCgroupUsed(pc)))
                return;
 
-       switch (idx) {
-       case MEMCG_NR_FILE_MAPPED:
-               idx = MEM_CGROUP_STAT_FILE_MAPPED;
-               break;
-       default:
-               BUG();
-       }
-
        this_cpu_add(memcg->stat->count[idx], val);
 }
 
@@ -2833,7 +2953,9 @@ static void __mem_cgroup_commit_charge(struct mem_cgroup *memcg,
        unlock_page_cgroup(pc);
 
        /*
-        * "charge_statistics" updated event counter.
+        * "charge_statistics" updated event counter. Then, check it.
+        * Insert ancestor (and ancestor's ancestors), to softlimit RB-tree.
+        * if they exceeds softlimit.
         */
        memcg_check_events(memcg, page);
 }
@@ -3676,6 +3798,20 @@ void mem_cgroup_split_huge_fixup(struct page *head)
 }
 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
 
+static inline
+void mem_cgroup_move_account_page_stat(struct mem_cgroup *from,
+                                       struct mem_cgroup *to,
+                                       unsigned int nr_pages,
+                                       enum mem_cgroup_stat_index idx)
+{
+       /* Update stat data for mem_cgroup */
+       preempt_disable();
+       WARN_ON_ONCE(from->stat->count[idx] < nr_pages);
+       __this_cpu_add(from->stat->count[idx], -nr_pages);
+       __this_cpu_add(to->stat->count[idx], nr_pages);
+       preempt_enable();
+}
+
 /**
  * mem_cgroup_move_account - move account of the page
  * @page: the page
@@ -3721,13 +3857,14 @@ static int mem_cgroup_move_account(struct page *page,
 
        move_lock_mem_cgroup(from, &flags);
 
-       if (!anon && page_mapped(page)) {
-               /* Update mapped_file data for mem_cgroup */
-               preempt_disable();
-               __this_cpu_dec(from->stat->count[MEM_CGROUP_STAT_FILE_MAPPED]);
-               __this_cpu_inc(to->stat->count[MEM_CGROUP_STAT_FILE_MAPPED]);
-               preempt_enable();
-       }
+       if (!anon && page_mapped(page))
+               mem_cgroup_move_account_page_stat(from, to, nr_pages,
+                       MEM_CGROUP_STAT_FILE_MAPPED);
+
+       if (PageWriteback(page))
+               mem_cgroup_move_account_page_stat(from, to, nr_pages,
+                       MEM_CGROUP_STAT_WRITEBACK);
+
        mem_cgroup_charge_statistics(from, page, anon, -nr_pages);
 
        /* caller should have done css_get */
@@ -4653,6 +4790,98 @@ static int mem_cgroup_resize_memsw_limit(struct mem_cgroup *memcg,
        return ret;
 }
 
+unsigned long mem_cgroup_soft_limit_reclaim(struct zone *zone, int order,
+                                           gfp_t gfp_mask,
+                                           unsigned long *total_scanned)
+{
+       unsigned long nr_reclaimed = 0;
+       struct mem_cgroup_per_zone *mz, *next_mz = NULL;
+       unsigned long reclaimed;
+       int loop = 0;
+       struct mem_cgroup_tree_per_zone *mctz;
+       unsigned long long excess;
+       unsigned long nr_scanned;
+
+       if (order > 0)
+               return 0;
+
+       mctz = soft_limit_tree_node_zone(zone_to_nid(zone), zone_idx(zone));
+       /*
+        * This loop can run a while, specially if mem_cgroup's continuously
+        * keep exceeding their soft limit and putting the system under
+        * pressure
+        */
+       do {
+               if (next_mz)
+                       mz = next_mz;
+               else
+                       mz = mem_cgroup_largest_soft_limit_node(mctz);
+               if (!mz)
+                       break;
+
+               nr_scanned = 0;
+               reclaimed = mem_cgroup_soft_reclaim(mz->memcg, zone,
+                                                   gfp_mask, &nr_scanned);
+               nr_reclaimed += reclaimed;
+               *total_scanned += nr_scanned;
+               spin_lock(&mctz->lock);
+
+               /*
+                * If we failed to reclaim anything from this memory cgroup
+                * it is time to move on to the next cgroup
+                */
+               next_mz = NULL;
+               if (!reclaimed) {
+                       do {
+                               /*
+                                * Loop until we find yet another one.
+                                *
+                                * By the time we get the soft_limit lock
+                                * again, someone might have aded the
+                                * group back on the RB tree. Iterate to
+                                * make sure we get a different mem.
+                                * mem_cgroup_largest_soft_limit_node returns
+                                * NULL if no other cgroup is present on
+                                * the tree
+                                */
+                               next_mz =
+                               __mem_cgroup_largest_soft_limit_node(mctz);
+                               if (next_mz == mz)
+                                       css_put(&next_mz->memcg->css);
+                               else /* next_mz == NULL or other memcg */
+                                       break;
+                       } while (1);
+               }
+               __mem_cgroup_remove_exceeded(mz->memcg, mz, mctz);
+               excess = res_counter_soft_limit_excess(&mz->memcg->res);
+               /*
+                * One school of thought says that we should not add
+                * back the node to the tree if reclaim returns 0.
+                * But our reclaim could return 0, simply because due
+                * to priority we are exposing a smaller subset of
+                * memory to reclaim from. Consider this as a longer
+                * term TODO.
+                */
+               /* If excess == 0, no tree ops */
+               __mem_cgroup_insert_exceeded(mz->memcg, mz, mctz, excess);
+               spin_unlock(&mctz->lock);
+               css_put(&mz->memcg->css);
+               loop++;
+               /*
+                * Could not reclaim anything and there are no more
+                * mem cgroups to try or we seem to be looping without
+                * reclaiming anything.
+                */
+               if (!nr_reclaimed &&
+                       (next_mz == NULL ||
+                       loop > MEM_CGROUP_MAX_SOFT_LIMIT_RECLAIM_LOOPS))
+                       break;
+       } while (!nr_reclaimed);
+       if (next_mz)
+               css_put(&next_mz->memcg->css);
+       return nr_reclaimed;
+}
+
 /**
  * mem_cgroup_force_empty_list - clears LRU of a group
  * @memcg: group to clear
@@ -5917,6 +6146,8 @@ static int alloc_mem_cgroup_per_zone_info(struct mem_cgroup *memcg, int node)
        for (zone = 0; zone < MAX_NR_ZONES; zone++) {
                mz = &pn->zoneinfo[zone];
                lruvec_init(&mz->lruvec);
+               mz->usage_in_excess = 0;
+               mz->on_tree = false;
                mz->memcg = memcg;
        }
        memcg->nodeinfo[node] = pn;
@@ -5972,6 +6203,7 @@ static void __mem_cgroup_free(struct mem_cgroup *memcg)
        int node;
        size_t size = memcg_size();
 
+       mem_cgroup_remove_from_trees(memcg);
        free_css_id(&mem_cgroup_subsys, &memcg->css);
 
        for_each_node(node)
@@ -6008,6 +6240,29 @@ struct mem_cgroup *parent_mem_cgroup(struct mem_cgroup *memcg)
 }
 EXPORT_SYMBOL(parent_mem_cgroup);
 
+static void __init mem_cgroup_soft_limit_tree_init(void)
+{
+       struct mem_cgroup_tree_per_node *rtpn;
+       struct mem_cgroup_tree_per_zone *rtpz;
+       int tmp, node, zone;
+
+       for_each_node(node) {
+               tmp = node;
+               if (!node_state(node, N_NORMAL_MEMORY))
+                       tmp = -1;
+               rtpn = kzalloc_node(sizeof(*rtpn), GFP_KERNEL, tmp);
+               BUG_ON(!rtpn);
+
+               soft_limit_tree.rb_tree_per_node[node] = rtpn;
+
+               for (zone = 0; zone < MAX_NR_ZONES; zone++) {
+                       rtpz = &rtpn->rb_tree_per_zone[zone];
+                       rtpz->rb_root = RB_ROOT;
+                       spin_lock_init(&rtpz->lock);
+               }
+       }
+}
+
 static struct cgroup_subsys_state * __ref
 mem_cgroup_css_alloc(struct cgroup_subsys_state *parent_css)
 {
@@ -6037,7 +6292,6 @@ mem_cgroup_css_alloc(struct cgroup_subsys_state *parent_css)
        mutex_init(&memcg->thresholds_lock);
        spin_lock_init(&memcg->move_lock);
        vmpressure_init(&memcg->vmpressure);
-       spin_lock_init(&memcg->soft_lock);
 
        return &memcg->css;
 
@@ -6115,13 +6369,6 @@ static void mem_cgroup_css_offline(struct cgroup_subsys_state *css)
 
        mem_cgroup_invalidate_reclaim_iterators(memcg);
        mem_cgroup_reparent_charges(memcg);
-       if (memcg->soft_contributed) {
-               while ((memcg = parent_mem_cgroup(memcg)))
-                       atomic_dec(&memcg->children_in_excess);
-
-               if (memcg != root_mem_cgroup && !root_mem_cgroup->use_hierarchy)
-                       atomic_dec(&root_mem_cgroup->children_in_excess);
-       }
        mem_cgroup_destroy_all_caches(memcg);
        vmpressure_cleanup(&memcg->vmpressure);
 }
@@ -6796,6 +7043,7 @@ static int __init mem_cgroup_init(void)
 {
        hotcpu_notifier(memcg_cpu_hotplug_callback, 0);
        enable_swap_cgroup();
+       mem_cgroup_soft_limit_tree_init();
        memcg_stock_init();
        return 0;
 }