1 files changed, 460 insertions, 293 deletions

diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index ddffc74cdebe..f4ec4e7ca4cd 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -35,7 +35,6 @@
 #include <linux/limits.h>
 #include <linux/mutex.h>
 #include <linux/rbtree.h>
-#include <linux/shmem_fs.h>
 #include <linux/slab.h>
 #include <linux/swap.h>
 #include <linux/swapops.h>
@@ -108,10 +107,12 @@ enum mem_cgroup_events_index {
 enum mem_cgroup_events_target {
 	MEM_CGROUP_TARGET_THRESH,
 	MEM_CGROUP_TARGET_SOFTLIMIT,
+	MEM_CGROUP_TARGET_NUMAINFO,
 	MEM_CGROUP_NTARGETS,
 };
 #define THRESHOLDS_EVENTS_TARGET (128)
 #define SOFTLIMIT_EVENTS_TARGET (1024)
+#define NUMAINFO_EVENTS_TARGET	(1024)
 
 struct mem_cgroup_stat_cpu {
 	long count[MEM_CGROUP_STAT_NSTATS];
@@ -203,6 +204,50 @@ struct mem_cgroup_eventfd_list {
 static void mem_cgroup_threshold(struct mem_cgroup *mem);
 static void mem_cgroup_oom_notify(struct mem_cgroup *mem);
 
+enum {
+	SCAN_BY_LIMIT,
+	SCAN_BY_SYSTEM,
+	NR_SCAN_CONTEXT,
+	SCAN_BY_SHRINK,	/* not recorded now */
+};
+
+enum {
+	SCAN,
+	SCAN_ANON,
+	SCAN_FILE,
+	ROTATE,
+	ROTATE_ANON,
+	ROTATE_FILE,
+	FREED,
+	FREED_ANON,
+	FREED_FILE,
+	ELAPSED,
+	NR_SCANSTATS,
+};
+
+struct scanstat {
+	spinlock_t	lock;
+	unsigned long	stats[NR_SCAN_CONTEXT][NR_SCANSTATS];
+	unsigned long	rootstats[NR_SCAN_CONTEXT][NR_SCANSTATS];
+};
+
+const char *scanstat_string[NR_SCANSTATS] = {
+	"scanned_pages",
+	"scanned_anon_pages",
+	"scanned_file_pages",
+	"rotated_pages",
+	"rotated_anon_pages",
+	"rotated_file_pages",
+	"freed_pages",
+	"freed_anon_pages",
+	"freed_file_pages",
+	"elapsed_ns",
+};
+#define SCANSTAT_WORD_LIMIT	"_by_limit"
+#define SCANSTAT_WORD_SYSTEM	"_by_system"
+#define SCANSTAT_WORD_HIERARCHY	"_under_hierarchy"
+
+
 /*
  * The memory controller data structure. The memory controller controls both
  * page cache and RSS per cgroup. We would eventually like to provide
@@ -237,16 +282,20 @@ struct mem_cgroup {
 	int last_scanned_node;
 #if MAX_NUMNODES > 1
 	nodemask_t	scan_nodes;
-	unsigned long   next_scan_node_update;
+	atomic_t	numainfo_events;
+	atomic_t	numainfo_updating;
 #endif
 	/*
 	 * Should the accounting and control be hierarchical, per subtree?
 	 */
 	bool use_hierarchy;
-	atomic_t	oom_lock;
+
+	bool		oom_lock;
+	atomic_t	under_oom;
+
 	atomic_t	refcnt;
 
-	unsigned int	swappiness;
+	int	swappiness;
 	/* OOM-Killer disable */
 	int		oom_kill_disable;
 
@@ -264,7 +313,8 @@ struct mem_cgroup {
 
 	/* For oom notifier event fd */
 	struct list_head oom_notify;
-
+	/* For recording LRU-scan statistics */
+	struct scanstat scanstat;
 	/*
 	 * Should we move charges of a task when a task is moved into this
 	 * mem_cgroup ? And what type of charges should we move ?
@@ -577,15 +627,6 @@ static long mem_cgroup_read_stat(struct mem_cgroup *mem,
 	return val;
 }
 
-static long mem_cgroup_local_usage(struct mem_cgroup *mem)
-{
-	long ret;
-
-	ret = mem_cgroup_read_stat(mem, MEM_CGROUP_STAT_RSS);
-	ret += mem_cgroup_read_stat(mem, MEM_CGROUP_STAT_CACHE);
-	return ret;
-}
-
 static void mem_cgroup_swap_statistics(struct mem_cgroup *mem,
 					 bool charge)
 {
@@ -642,27 +683,44 @@ static void mem_cgroup_charge_statistics(struct mem_cgroup *mem,
 	preempt_enable();
 }
 
-static unsigned long
-mem_cgroup_get_zonestat_node(struct mem_cgroup *mem, int nid, enum lru_list idx)
+unsigned long
+mem_cgroup_zone_nr_lru_pages(struct mem_cgroup *mem, int nid, int zid,
+			unsigned int lru_mask)
 {
 	struct mem_cgroup_per_zone *mz;
+	enum lru_list l;
+	unsigned long ret = 0;
+
+	mz = mem_cgroup_zoneinfo(mem, nid, zid);
+
+	for_each_lru(l) {
+		if (BIT(l) & lru_mask)
+			ret += MEM_CGROUP_ZSTAT(mz, l);
+	}
+	return ret;
+}
+
+static unsigned long
+mem_cgroup_node_nr_lru_pages(struct mem_cgroup *mem,
+			int nid, unsigned int lru_mask)
+{
 	u64 total = 0;
 	int zid;
 
-	for (zid = 0; zid < MAX_NR_ZONES; zid++) {
-		mz = mem_cgroup_zoneinfo(mem, nid, zid);
-		total += MEM_CGROUP_ZSTAT(mz, idx);
-	}
+	for (zid = 0; zid < MAX_NR_ZONES; zid++)
+		total += mem_cgroup_zone_nr_lru_pages(mem, nid, zid, lru_mask);
+
 	return total;
 }
-static unsigned long mem_cgroup_get_local_zonestat(struct mem_cgroup *mem,
-					enum lru_list idx)
+
+static unsigned long mem_cgroup_nr_lru_pages(struct mem_cgroup *mem,
+			unsigned int lru_mask)
 {
 	int nid;
 	u64 total = 0;
 
-	for_each_online_node(nid)
-		total += mem_cgroup_get_zonestat_node(mem, nid, idx);
+	for_each_node_state(nid, N_HIGH_MEMORY)
+		total += mem_cgroup_node_nr_lru_pages(mem, nid, lru_mask);
 	return total;
 }
 
@@ -689,6 +747,9 @@ static void __mem_cgroup_target_update(struct mem_cgroup *mem, int target)
 	case MEM_CGROUP_TARGET_SOFTLIMIT:
 		next = val + SOFTLIMIT_EVENTS_TARGET;
 		break;
+	case MEM_CGROUP_TARGET_NUMAINFO:
+		next = val + NUMAINFO_EVENTS_TARGET;
+		break;
 	default:
 		return;
 	}
@@ -707,11 +768,19 @@ static void memcg_check_events(struct mem_cgroup *mem, struct page *page)
 		mem_cgroup_threshold(mem);
 		__mem_cgroup_target_update(mem, MEM_CGROUP_TARGET_THRESH);
 		if (unlikely(__memcg_event_check(mem,
-			MEM_CGROUP_TARGET_SOFTLIMIT))){
+			     MEM_CGROUP_TARGET_SOFTLIMIT))) {
 			mem_cgroup_update_tree(mem, page);
 			__mem_cgroup_target_update(mem,
-				MEM_CGROUP_TARGET_SOFTLIMIT);
+						   MEM_CGROUP_TARGET_SOFTLIMIT);
 		}
+#if MAX_NUMNODES > 1
+		if (unlikely(__memcg_event_check(mem,
+			MEM_CGROUP_TARGET_NUMAINFO))) {
+			atomic_inc(&mem->numainfo_events);
+			__mem_cgroup_target_update(mem,
+				MEM_CGROUP_TARGET_NUMAINFO);
+		}
+#endif
 	}
 }
 
@@ -1038,6 +1107,21 @@ void mem_cgroup_move_lists(struct page *page,
 	mem_cgroup_add_lru_list(page, to);
 }
 
+/*
+ * Checks whether given mem is same or in the root_mem's
+ * hierarchy subtree
+ */
+static bool mem_cgroup_same_or_subtree(const struct mem_cgroup *root_mem,
+		struct mem_cgroup *mem)
+{
+	if (root_mem != mem) {
+		return (root_mem->use_hierarchy &&
+			css_is_ancestor(&mem->css, &root_mem->css));
+	}
+
+	return true;
+}
+
 int task_in_mem_cgroup(struct task_struct *task, const struct mem_cgroup *mem)
 {
 	int ret;
@@ -1057,10 +1141,7 @@ int task_in_mem_cgroup(struct task_struct *task, const struct mem_cgroup *mem)
 	 * enabled in "curr" and "curr" is a child of "mem" in *cgroup*
 	 * hierarchy(even if use_hierarchy is disabled in "mem").
 	 */
-	if (mem->use_hierarchy)
-		ret = css_is_ancestor(&curr->css, &mem->css);
-	else
-		ret = (curr == mem);
+	ret = mem_cgroup_same_or_subtree(mem, curr);
 	css_put(&curr->css);
 	return ret;
 }
@@ -1072,8 +1153,8 @@ static int calc_inactive_ratio(struct mem_cgroup *memcg, unsigned long *present_
 	unsigned long gb;
 	unsigned long inactive_ratio;
 
-	inactive = mem_cgroup_get_local_zonestat(memcg, LRU_INACTIVE_ANON);
-	active = mem_cgroup_get_local_zonestat(memcg, LRU_ACTIVE_ANON);
+	inactive = mem_cgroup_nr_lru_pages(memcg, BIT(LRU_INACTIVE_ANON));
+	active = mem_cgroup_nr_lru_pages(memcg, BIT(LRU_ACTIVE_ANON));
 
 	gb = (inactive + active) >> (30 - PAGE_SHIFT);
 	if (gb)
@@ -1112,110 +1193,12 @@ 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);
+	inactive = mem_cgroup_nr_lru_pages(memcg, BIT(LRU_INACTIVE_FILE));
+	active = mem_cgroup_nr_lru_pages(memcg, BIT(LRU_ACTIVE_FILE));
 
 	return (active > inactive);
 }
 
-unsigned long mem_cgroup_zone_nr_lru_pages(struct mem_cgroup *memcg,
-						struct zone *zone,
-						enum lru_list lru)
-{
-	int nid = zone_to_nid(zone);
-	int zid = zone_idx(zone);
-	struct mem_cgroup_per_zone *mz = mem_cgroup_zoneinfo(memcg, nid, zid);
-
-	return MEM_CGROUP_ZSTAT(mz, lru);
-}
-
-#ifdef CONFIG_NUMA
-static unsigned long mem_cgroup_node_nr_file_lru_pages(struct mem_cgroup *memcg,
-							int nid)
-{
-	unsigned long ret;
-
-	ret = mem_cgroup_get_zonestat_node(memcg, nid, LRU_INACTIVE_FILE) +
-		mem_cgroup_get_zonestat_node(memcg, nid, LRU_ACTIVE_FILE);
-
-	return ret;
-}
-
-static unsigned long mem_cgroup_nr_file_lru_pages(struct mem_cgroup *memcg)
-{
-	u64 total = 0;
-	int nid;
-
-	for_each_node_state(nid, N_HIGH_MEMORY)
-		total += mem_cgroup_node_nr_file_lru_pages(memcg, nid);
-
-	return total;
-}
-
-static unsigned long mem_cgroup_node_nr_anon_lru_pages(struct mem_cgroup *memcg,
-							int nid)
-{
-	unsigned long ret;
-
-	ret = mem_cgroup_get_zonestat_node(memcg, nid, LRU_INACTIVE_ANON) +
-		mem_cgroup_get_zonestat_node(memcg, nid, LRU_ACTIVE_ANON);
-
-	return ret;
-}
-
-static unsigned long mem_cgroup_nr_anon_lru_pages(struct mem_cgroup *memcg)
-{
-	u64 total = 0;
-	int nid;
-
-	for_each_node_state(nid, N_HIGH_MEMORY)
-		total += mem_cgroup_node_nr_anon_lru_pages(memcg, nid);
-
-	return total;
-}
-
-static unsigned long
-mem_cgroup_node_nr_unevictable_lru_pages(struct mem_cgroup *memcg, int nid)
-{
-	return mem_cgroup_get_zonestat_node(memcg, nid, LRU_UNEVICTABLE);
-}
-
-static unsigned long
-mem_cgroup_nr_unevictable_lru_pages(struct mem_cgroup *memcg)
-{
-	u64 total = 0;
-	int nid;
-
-	for_each_node_state(nid, N_HIGH_MEMORY)
-		total += mem_cgroup_node_nr_unevictable_lru_pages(memcg, nid);
-
-	return total;
-}
-
-static unsigned long mem_cgroup_node_nr_lru_pages(struct mem_cgroup *memcg,
-							int nid)
-{
-	enum lru_list l;
-	u64 total = 0;
-
-	for_each_lru(l)
-		total += mem_cgroup_get_zonestat_node(memcg, nid, l);
-
-	return total;
-}
-
-static unsigned long mem_cgroup_nr_lru_pages(struct mem_cgroup *memcg)
-{
-	u64 total = 0;
-	int nid;
-
-	for_each_node_state(nid, N_HIGH_MEMORY)
-		total += mem_cgroup_node_nr_lru_pages(memcg, nid);
-
-	return total;
-}
-#endif /* CONFIG_NUMA */
-
 struct zone_reclaim_stat *mem_cgroup_get_reclaim_stat(struct mem_cgroup *memcg,
 						      struct zone *zone)
 {
@@ -1325,7 +1308,7 @@ static unsigned long mem_cgroup_margin(struct mem_cgroup *mem)
 	return margin >> PAGE_SHIFT;
 }
 
-static unsigned int get_swappiness(struct mem_cgroup *memcg)
+int mem_cgroup_swappiness(struct mem_cgroup *memcg)
 {
 	struct cgroup *cgrp = memcg->css.cgroup;
 
@@ -1397,10 +1380,9 @@ static bool mem_cgroup_under_move(struct mem_cgroup *mem)
 	to = mc.to;
 	if (!from)
 		goto unlock;
-	if (from == mem || to == mem
-	    || (mem->use_hierarchy && css_is_ancestor(&from->css, &mem->css))
-	    || (mem->use_hierarchy && css_is_ancestor(&to->css,	&mem->css)))
-		ret = true;
+
+	ret = mem_cgroup_same_or_subtree(mem, from)
+		|| mem_cgroup_same_or_subtree(mem, to);
 unlock:
 	spin_unlock(&mc.lock);
 	return ret;
@@ -1559,6 +1541,28 @@ mem_cgroup_select_victim(struct mem_cgroup *root_mem)
 	return ret;
 }
 
+/**
+ * test_mem_cgroup_node_reclaimable
+ * @mem: the target memcg
+ * @nid: the node ID to be checked.
+ * @noswap : specify true here if the user wants flle only information.
+ *
+ * This function returns whether the specified memcg contains any
+ * reclaimable pages on a node. Returns true if there are any reclaimable
+ * pages in the node.
+ */
+static bool test_mem_cgroup_node_reclaimable(struct mem_cgroup *mem,
+		int nid, bool noswap)
+{
+	if (mem_cgroup_node_nr_lru_pages(mem, nid, LRU_ALL_FILE))
+		return true;
+	if (noswap || !total_swap_pages)
+		return false;
+	if (mem_cgroup_node_nr_lru_pages(mem, nid, LRU_ALL_ANON))
+		return true;
+	return false;
+
+}
 #if MAX_NUMNODES > 1
 
 /*
@@ -1570,26 +1574,26 @@ mem_cgroup_select_victim(struct mem_cgroup *root_mem)
 static void mem_cgroup_may_update_nodemask(struct mem_cgroup *mem)
 {
 	int nid;
-
-	if (time_after(mem->next_scan_node_update, jiffies))
+	/*
+	 * numainfo_events > 0 means there was at least NUMAINFO_EVENTS_TARGET
+	 * pagein/pageout changes since the last update.
+	 */
+	if (!atomic_read(&mem->numainfo_events))
+		return;
+	if (atomic_inc_return(&mem->numainfo_updating) > 1)
 		return;
 
-	mem->next_scan_node_update = jiffies + 10*HZ;
 	/* make a nodemask where this memcg uses memory from */
 	mem->scan_nodes = node_states[N_HIGH_MEMORY];
 
 	for_each_node_mask(nid, node_states[N_HIGH_MEMORY]) {
 
-		if (mem_cgroup_get_zonestat_node(mem, nid, LRU_INACTIVE_FILE) ||
-		    mem_cgroup_get_zonestat_node(mem, nid, LRU_ACTIVE_FILE))
-			continue;
-
-		if (total_swap_pages &&
-		    (mem_cgroup_get_zonestat_node(mem, nid, LRU_INACTIVE_ANON) ||
-		     mem_cgroup_get_zonestat_node(mem, nid, LRU_ACTIVE_ANON)))
-			continue;
-		node_clear(nid, mem->scan_nodes);
+		if (!test_mem_cgroup_node_reclaimable(mem, nid, false))
+			node_clear(nid, mem->scan_nodes);
 	}
+
+	atomic_set(&mem->numainfo_events, 0);
+	atomic_set(&mem->numainfo_updating, 0);
 }
 
 /*
@@ -1627,13 +1631,91 @@ int mem_cgroup_select_victim_node(struct mem_cgroup *mem)
 	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.
+ */
+bool mem_cgroup_reclaimable(struct mem_cgroup *mem, bool noswap)
+{
+	int nid;
+
+	/*
+	 * quick check...making use of scan_node.
+	 * We can skip unused nodes.
+	 */
+	if (!nodes_empty(mem->scan_nodes)) {
+		for (nid = first_node(mem->scan_nodes);
+		     nid < MAX_NUMNODES;
+		     nid = next_node(nid, mem->scan_nodes)) {
+
+			if (test_mem_cgroup_node_reclaimable(mem, nid, noswap))
+				return true;
+		}
+	}
+	/*
+	 * Check rest of nodes.
+	 */
+	for_each_node_state(nid, N_HIGH_MEMORY) {
+		if (node_isset(nid, mem->scan_nodes))
+			continue;
+		if (test_mem_cgroup_node_reclaimable(mem, nid, noswap))
+			return true;
+	}
+	return false;
+}
+
 #else
 int mem_cgroup_select_victim_node(struct mem_cgroup *mem)
 {
 	return 0;
 }
+
+bool mem_cgroup_reclaimable(struct mem_cgroup *mem, bool noswap)
+{
+	return test_mem_cgroup_node_reclaimable(mem, 0, noswap);
+}
 #endif
 
+static void __mem_cgroup_record_scanstat(unsigned long *stats,
+			   struct memcg_scanrecord *rec)
+{
+
+	stats[SCAN] += rec->nr_scanned[0] + rec->nr_scanned[1];
+	stats[SCAN_ANON] += rec->nr_scanned[0];
+	stats[SCAN_FILE] += rec->nr_scanned[1];
+
+	stats[ROTATE] += rec->nr_rotated[0] + rec->nr_rotated[1];
+	stats[ROTATE_ANON] += rec->nr_rotated[0];
+	stats[ROTATE_FILE] += rec->nr_rotated[1];
+
+	stats[FREED] += rec->nr_freed[0] + rec->nr_freed[1];
+	stats[FREED_ANON] += rec->nr_freed[0];
+	stats[FREED_FILE] += rec->nr_freed[1];
+
+	stats[ELAPSED] += rec->elapsed;
+}
+
+static void mem_cgroup_record_scanstat(struct memcg_scanrecord *rec)
+{
+	struct mem_cgroup *mem;
+	int context = rec->context;
+
+	if (context >= NR_SCAN_CONTEXT)
+		return;
+
+	mem = rec->mem;
+	spin_lock(&mem->scanstat.lock);
+	__mem_cgroup_record_scanstat(mem->scanstat.stats[context], rec);
+	spin_unlock(&mem->scanstat.lock);
+
+	mem = rec->root;
+	spin_lock(&mem->scanstat.lock);
+	__mem_cgroup_record_scanstat(mem->scanstat.rootstats[context], rec);
+	spin_unlock(&mem->scanstat.lock);
+}
+
 /*
  * Scan the hierarchy if needed to reclaim memory. We remember the last child
  * we reclaimed from, so that we don't end up penalizing one child extensively
@@ -1658,15 +1740,25 @@ static int mem_cgroup_hierarchical_reclaim(struct mem_cgroup *root_mem,
 	bool noswap = reclaim_options & MEM_CGROUP_RECLAIM_NOSWAP;
 	bool shrink = reclaim_options & MEM_CGROUP_RECLAIM_SHRINK;
 	bool check_soft = reclaim_options & MEM_CGROUP_RECLAIM_SOFT;
+	struct memcg_scanrecord rec;
 	unsigned long excess;
-	unsigned long nr_scanned;
+	unsigned long scanned;
 
 	excess = res_counter_soft_limit_excess(&root_mem->res) >> PAGE_SHIFT;
 
 	/* If memsw_is_minimum==1, swap-out is of-no-use. */
-	if (!check_soft && root_mem->memsw_is_minimum)
+	if (!check_soft && !shrink && root_mem->memsw_is_minimum)
 		noswap = true;
 
+	if (shrink)
+		rec.context = SCAN_BY_SHRINK;
+	else if (check_soft)
+		rec.context = SCAN_BY_SYSTEM;
+	else
+		rec.context = SCAN_BY_LIMIT;
+
+	rec.root = root_mem;
+
 	while (1) {
 		victim = mem_cgroup_select_victim(root_mem);
 		if (victim == root_mem) {
@@ -1702,20 +1794,28 @@ static int mem_cgroup_hierarchical_reclaim(struct mem_cgroup *root_mem,
 				}
 			}
 		}
-		if (!mem_cgroup_local_usage(victim)) {
+		if (!mem_cgroup_reclaimable(victim, noswap)) {
 			/* this cgroup's local usage == 0 */
 			css_put(&victim->css);
 			continue;
 		}
+		rec.mem = victim;
+		rec.nr_scanned[0] = 0;
+		rec.nr_scanned[1] = 0;
+		rec.nr_rotated[0] = 0;
+		rec.nr_rotated[1] = 0;
+		rec.nr_freed[0] = 0;
+		rec.nr_freed[1] = 0;
+		rec.elapsed = 0;
 		/* we use swappiness of local cgroup */
 		if (check_soft) {
 			ret = mem_cgroup_shrink_node_zone(victim, gfp_mask,
-				noswap, get_swappiness(victim), zone,
-				&nr_scanned);
-			*total_scanned += nr_scanned;
+				noswap, zone, &rec, &scanned);
+			*total_scanned += scanned;
 		} else
 			ret = try_to_free_mem_cgroup_pages(victim, gfp_mask,
-						noswap, get_swappiness(victim));
+						noswap, &rec);
+		mem_cgroup_record_scanstat(&rec);
 		css_put(&victim->css);
 		/*
 		 * At shrinking usage, we can't check we should stop here or
@@ -1737,38 +1837,84 @@ static int mem_cgroup_hierarchical_reclaim(struct mem_cgroup *root_mem,
 /*
  * Check OOM-Killer is already running under our hierarchy.
  * If someone is running, return false.
+ * Has to be called with memcg_oom_lock
  */
 static bool mem_cgroup_oom_lock(struct mem_cgroup *mem)
 {
-	int x, lock_count = 0;
-	struct mem_cgroup *iter;
+	int lock_count = -1;
+	struct mem_cgroup *iter, *failed = NULL;
+	bool cond = true;
+
+	for_each_mem_cgroup_tree_cond(iter, mem, cond) {
+		bool locked = iter->oom_lock;
 
-	for_each_mem_cgroup_tree(iter, mem) {
-		x = atomic_inc_return(&iter->oom_lock);
-		lock_count = max(x, lock_count);
+		iter->oom_lock = true;
+		if (lock_count == -1)
+			lock_count = iter->oom_lock;
+		else if (lock_count != locked) {
+			/*
+			 * this subtree of our hierarchy is already locked
+			 * so we cannot give a lock.
+			 */
+			lock_count = 0;
+			failed = iter;
+			cond = false;
+		}
 	}
 
-	if (lock_count == 1)
-		return true;
-	return false;
+	if (!failed)
+		goto done;
+
+	/*
+	 * OK, we failed to lock the whole subtree so we have to clean up
+	 * what we set up to the failing subtree
+	 */
+	cond = true;
+	for_each_mem_cgroup_tree_cond(iter, mem, cond) {
+		if (iter == failed) {
+			cond = false;
+			continue;
+		}
+		iter->oom_lock = false;
+	}
+done:
+	return lock_count;
 }
 
+/*
+ * Has to be called with memcg_oom_lock
+ */
 static int mem_cgroup_oom_unlock(struct mem_cgroup *mem)
 {
 	struct mem_cgroup *iter;
 
+	for_each_mem_cgroup_tree(iter, mem)
+		iter->oom_lock = false;
+	return 0;
+}
+
+static void mem_cgroup_mark_under_oom(struct mem_cgroup *mem)
+{
+	struct mem_cgroup *iter;
+
+	for_each_mem_cgroup_tree(iter, mem)
+		atomic_inc(&iter->under_oom);
+}
+
+static void mem_cgroup_unmark_under_oom(struct mem_cgroup *mem)
+{
+	struct mem_cgroup *iter;
+
 	/*
 	 * When a new child is created while the hierarchy is under oom,
 	 * mem_cgroup_oom_lock() may not be called. We have to use
 	 * atomic_add_unless() here.
 	 */
 	for_each_mem_cgroup_tree(iter, mem)
-		atomic_add_unless(&iter->oom_lock, -1, 0);
-	return 0;
+		atomic_add_unless(&iter->under_oom, -1, 0);
 }
 
-
-static DEFINE_MUTEX(memcg_oom_mutex);
+static DEFINE_SPINLOCK(memcg_oom_lock);
 static DECLARE_WAIT_QUEUE_HEAD(memcg_oom_waitq);
 
 struct oom_wait_info {
@@ -1779,25 +1925,20 @@ struct oom_wait_info {
 static int memcg_oom_wake_function(wait_queue_t *wait,
 	unsigned mode, int sync, void *arg)
 {
-	struct mem_cgroup *wake_mem = (struct mem_cgroup *)arg;
+	struct mem_cgroup *wake_mem = (struct mem_cgroup *)arg,
+			  *oom_wait_mem;
 	struct oom_wait_info *oom_wait_info;
 
 	oom_wait_info = container_of(wait, struct oom_wait_info, wait);
+	oom_wait_mem = oom_wait_info->mem;
 
-	if (oom_wait_info->mem == wake_mem)
-		goto wakeup;
-	/* if no hierarchy, no match */
-	if (!oom_wait_info->mem->use_hierarchy || !wake_mem->use_hierarchy)
-		return 0;
 	/*
 	 * Both of oom_wait_info->mem and wake_mem are stable under us.
 	 * Then we can use css_is_ancestor without taking care of RCU.
 	 */
-	if (!css_is_ancestor(&oom_wait_info->mem->css, &wake_mem->css) &&
-	    !css_is_ancestor(&wake_mem->css, &oom_wait_info->mem->css))
+	if (!mem_cgroup_same_or_subtree(oom_wait_mem, wake_mem)
+			&& !mem_cgroup_same_or_subtree(wake_mem, oom_wait_mem))
 		return 0;
-
-wakeup:
 	return autoremove_wake_function(wait, mode, sync, arg);
 }
 
@@ -1809,7 +1950,7 @@ static void memcg_wakeup_oom(struct mem_cgroup *mem)
 
 static void memcg_oom_recover(struct mem_cgroup *mem)
 {
-	if (mem && atomic_read(&mem->oom_lock))
+	if (mem && atomic_read(&mem->under_oom))
 		memcg_wakeup_oom(mem);
 }
 
@@ -1827,8 +1968,10 @@ bool mem_cgroup_handle_oom(struct mem_cgroup *mem, gfp_t mask)
 	owait.wait.private = current;
 	INIT_LIST_HEAD(&owait.wait.task_list);
 	need_to_kill = true;
+	mem_cgroup_mark_under_oom(mem);
+
 	/* At first, try to OOM lock hierarchy under mem.*/
-	mutex_lock(&memcg_oom_mutex);
+	spin_lock(&memcg_oom_lock);
 	locked = mem_cgroup_oom_lock(mem);
 	/*
 	 * Even if signal_pending(), we can't quit charge() loop without
@@ -1840,7 +1983,7 @@ bool mem_cgroup_handle_oom(struct mem_cgroup *mem, gfp_t mask)
 		need_to_kill = false;
 	if (locked)
 		mem_cgroup_oom_notify(mem);
-	mutex_unlock(&memcg_oom_mutex);
+	spin_unlock(&memcg_oom_lock);
 
 	if (need_to_kill) {
 		finish_wait(&memcg_oom_waitq, &owait.wait);
@@ -1849,10 +1992,13 @@ bool mem_cgroup_handle_oom(struct mem_cgroup *mem, gfp_t mask)
 		schedule();
 		finish_wait(&memcg_oom_waitq, &owait.wait);
 	}
-	mutex_lock(&memcg_oom_mutex);
-	mem_cgroup_oom_unlock(mem);
+	spin_lock(&memcg_oom_lock);
+	if (locked)
+		mem_cgroup_oom_unlock(mem);
 	memcg_wakeup_oom(mem);
-	mutex_unlock(&memcg_oom_mutex);
+	spin_unlock(&memcg_oom_lock);
+
+	mem_cgroup_unmark_under_oom(mem);
 
 	if (test_thread_flag(TIF_MEMDIE) || fatal_signal_pending(current))
 		return false;
@@ -1945,7 +2091,6 @@ struct memcg_stock_pcp {
 #define FLUSHING_CACHED_CHARGE	(0)
 };
 static DEFINE_PER_CPU(struct memcg_stock_pcp, memcg_stock);
-static DEFINE_MUTEX(percpu_charge_mutex);
 
 /*
  * Try to consume stocked charge on this cpu. If success, one page is consumed
@@ -2013,19 +2158,14 @@ static void refill_stock(struct mem_cgroup *mem, unsigned int nr_pages)
 }
 
 /*
- * Tries to drain stocked charges in other cpus. This function is asynchronous
- * and just put a work per cpu for draining localy on each cpu. Caller can
- * expects some charges will be back to res_counter later but cannot wait for
- * it.
+ * Drains all per-CPU charge caches for given root_mem resp. subtree
+ * of the hierarchy under it. sync flag says whether we should block
+ * until the work is done.
  */
-static void drain_all_stock_async(struct mem_cgroup *root_mem)
+static void drain_all_stock(struct mem_cgroup *root_mem, bool sync)
 {
 	int cpu, curcpu;
-	/*
-	 * If someone calls draining, avoid adding more kworker runs.
-	 */
-	if (!mutex_trylock(&percpu_charge_mutex))
-		return;
+
 	/* Notify other cpus that system-wide "drain" is running */
 	get_online_cpus();
 	/*
@@ -2039,34 +2179,48 @@ static void drain_all_stock_async(struct mem_cgroup *root_mem)
 		struct memcg_stock_pcp *stock = &per_cpu(memcg_stock, cpu);
 		struct mem_cgroup *mem;
 
-		if (cpu == curcpu)
-			continue;
-
 		mem = stock->cached;
-		if (!mem)
+		if (!mem || !stock->nr_pages)
 			continue;
-		if (mem != root_mem) {
-			if (!root_mem->use_hierarchy)
-				continue;
-			/* check whether "mem" is under tree of "root_mem" */
-			if (!css_is_ancestor(&mem->css, &root_mem->css))
-				continue;
+		if (!mem_cgroup_same_or_subtree(root_mem, mem))
+			continue;
+		if (!test_and_set_bit(FLUSHING_CACHED_CHARGE, &stock->flags)) {
+			if (cpu == curcpu)
+				drain_local_stock(&stock->work);
+			else
+				schedule_work_on(cpu, &stock->work);
 		}
-		if (!test_and_set_bit(FLUSHING_CACHED_CHARGE, &stock->flags))
-			schedule_work_on(cpu, &stock->work);
 	}
+
+	if (!sync)
+		goto out;
+
+	for_each_online_cpu(cpu) {
+		struct memcg_stock_pcp *stock = &per_cpu(memcg_stock, cpu);
+		if (mem_cgroup_same_or_subtree(root_mem, stock->cached) &&
+				test_bit(FLUSHING_CACHED_CHARGE, &stock->flags))
+			flush_work(&stock->work);
+	}
+out:
  	put_online_cpus();
-	mutex_unlock(&percpu_charge_mutex);
-	/* We don't wait for flush_work */
+}
+
+/*
+ * Tries to drain stocked charges in other cpus. This function is asynchronous
+ * and just put a work per cpu for draining localy on each cpu. Caller can
+ * expects some charges will be back to res_counter later but cannot wait for
+ * it.
+ */
+static void drain_all_stock_async(struct mem_cgroup *root_mem)
+{
+	drain_all_stock(root_mem, false);
 }
 
 /* This is a synchronous drain interface. */
-static void drain_all_stock_sync(void)
+static void drain_all_stock_sync(struct mem_cgroup *root_mem)
 {
 	/* called when force_empty is called */
-	mutex_lock(&percpu_charge_mutex);
-	schedule_on_each_cpu(drain_local_stock);
-	mutex_unlock(&percpu_charge_mutex);
+	drain_all_stock(root_mem, true);
 }
 
 /*
@@ -2718,30 +2872,6 @@ int mem_cgroup_cache_charge(struct page *page, struct mm_struct *mm,
 		return 0;
 	if (PageCompound(page))
 		return 0;
-	/*
-	 * Corner case handling. This is called from add_to_page_cache()
-	 * in usual. But some FS (shmem) precharges this page before calling it
-	 * and call add_to_page_cache() with GFP_NOWAIT.
-	 *
-	 * For GFP_NOWAIT case, the page may be pre-charged before calling
-	 * add_to_page_cache(). (See shmem.c) check it here and avoid to call
-	 * charge twice. (It works but has to pay a bit larger cost.)
-	 * And when the page is SwapCache, it should take swap information
-	 * into account. This is under lock_page() now.
-	 */
-	if (!(gfp_mask & __GFP_WAIT)) {
-		struct page_cgroup *pc;
-
-		pc = lookup_page_cgroup(page);
-		if (!pc)
-			return 0;
-		lock_page_cgroup(pc);
-		if (PageCgroupUsed(pc)) {
-			unlock_page_cgroup(pc);
-			return 0;
-		}
-		unlock_page_cgroup(pc);
-	}
 
 	if (unlikely(!mm))
 		mm = &init_mm;
@@ -3331,31 +3461,6 @@ void mem_cgroup_end_migration(struct mem_cgroup *mem,
 	cgroup_release_and_wakeup_rmdir(&mem->css);
 }
 
-/*
- * 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_shmem_charge_fallback(struct page *page,
-			    struct mm_struct *mm,
-			    gfp_t gfp_mask)
-{
-	struct mem_cgroup *mem;
-	int ret;
-
-	if (mem_cgroup_disabled())
-		return 0;
-
-	ret = mem_cgroup_try_charge_swapin(mm, page, gfp_mask, &mem);
-	if (!ret)
-		mem_cgroup_cancel_charge_swapin(mem); /* it does !mem check */
-
-	return ret;
-}
-
 #ifdef CONFIG_DEBUG_VM
 static struct page_cgroup *lookup_page_cgroup_used(struct page *page)
 {
@@ -3714,7 +3819,7 @@ move_account:
 			goto out;
 		/* This is for making all *used* pages to be on LRU. */
 		lru_add_drain_all();
-		drain_all_stock_sync();
+		drain_all_stock_sync(mem);
 		ret = 0;
 		mem_cgroup_start_move(mem);
 		for_each_node_state(node, N_HIGH_MEMORY) {
@@ -3753,14 +3858,18 @@ try_to_free:
 	/* try to free all pages in this cgroup */
 	shrink = 1;
 	while (nr_retries && mem->res.usage > 0) {
+		struct memcg_scanrecord rec;
 		int progress;
 
 		if (signal_pending(current)) {
 			ret = -EINTR;
 			goto out;
 		}
+		rec.context = SCAN_BY_SHRINK;
+		rec.mem = mem;
+		rec.root = mem;
 		progress = try_to_free_mem_cgroup_pages(mem, GFP_KERNEL,
-						false, get_swappiness(mem));
+						false, &rec);
 		if (!progress) {
 			nr_retries--;
 			/* maybe some writeback is necessary */
@@ -4086,15 +4195,15 @@ mem_cgroup_get_local_stat(struct mem_cgroup *mem, struct mcs_total_stat *s)
 	s->stat[MCS_PGMAJFAULT] += val;
 
 	/* per zone stat */
-	val = mem_cgroup_get_local_zonestat(mem, LRU_INACTIVE_ANON);
+	val = mem_cgroup_nr_lru_pages(mem, BIT(LRU_INACTIVE_ANON));
 	s->stat[MCS_INACTIVE_ANON] += val * PAGE_SIZE;
-	val = mem_cgroup_get_local_zonestat(mem, LRU_ACTIVE_ANON);
+	val = mem_cgroup_nr_lru_pages(mem, BIT(LRU_ACTIVE_ANON));
 	s->stat[MCS_ACTIVE_ANON] += val * PAGE_SIZE;
-	val = mem_cgroup_get_local_zonestat(mem, LRU_INACTIVE_FILE);
+	val = mem_cgroup_nr_lru_pages(mem, BIT(LRU_INACTIVE_FILE));
 	s->stat[MCS_INACTIVE_FILE] += val * PAGE_SIZE;
-	val = mem_cgroup_get_local_zonestat(mem, LRU_ACTIVE_FILE);
+	val = mem_cgroup_nr_lru_pages(mem, BIT(LRU_ACTIVE_FILE));
 	s->stat[MCS_ACTIVE_FILE] += val * PAGE_SIZE;
-	val = mem_cgroup_get_local_zonestat(mem, LRU_UNEVICTABLE);
+	val = mem_cgroup_nr_lru_pages(mem, BIT(LRU_UNEVICTABLE));
 	s->stat[MCS_UNEVICTABLE] += val * PAGE_SIZE;
 }
 
@@ -4116,35 +4225,37 @@ static int mem_control_numa_stat_show(struct seq_file *m, void *arg)
 	struct cgroup *cont = m->private;
 	struct mem_cgroup *mem_cont = mem_cgroup_from_cont(cont);
 
-	total_nr = mem_cgroup_nr_lru_pages(mem_cont);
+	total_nr = mem_cgroup_nr_lru_pages(mem_cont, LRU_ALL);
 	seq_printf(m, "total=%lu", total_nr);
 	for_each_node_state(nid, N_HIGH_MEMORY) {
-		node_nr = mem_cgroup_node_nr_lru_pages(mem_cont, nid);
+		node_nr = mem_cgroup_node_nr_lru_pages(mem_cont, nid, LRU_ALL);
 		seq_printf(m, " N%d=%lu", nid, node_nr);
 	}
 	seq_putc(m, '\n');
 
-	file_nr = mem_cgroup_nr_file_lru_pages(mem_cont);
+	file_nr = mem_cgroup_nr_lru_pages(mem_cont, LRU_ALL_FILE);
 	seq_printf(m, "file=%lu", file_nr);
 	for_each_node_state(nid, N_HIGH_MEMORY) {
-		node_nr = mem_cgroup_node_nr_file_lru_pages(mem_cont, nid);
+		node_nr = mem_cgroup_node_nr_lru_pages(mem_cont, nid,
+				LRU_ALL_FILE);
 		seq_printf(m, " N%d=%lu", nid, node_nr);
 	}
 	seq_putc(m, '\n');
 
-	anon_nr = mem_cgroup_nr_anon_lru_pages(mem_cont);
+	anon_nr = mem_cgroup_nr_lru_pages(mem_cont, LRU_ALL_ANON);
 	seq_printf(m, "anon=%lu", anon_nr);
 	for_each_node_state(nid, N_HIGH_MEMORY) {
-		node_nr = mem_cgroup_node_nr_anon_lru_pages(mem_cont, nid);
+		node_nr = mem_cgroup_node_nr_lru_pages(mem_cont, nid,
+				LRU_ALL_ANON);
 		seq_printf(m, " N%d=%lu", nid, node_nr);
 	}
 	seq_putc(m, '\n');
 
-	unevictable_nr = mem_cgroup_nr_unevictable_lru_pages(mem_cont);
+	unevictable_nr = mem_cgroup_nr_lru_pages(mem_cont, BIT(LRU_UNEVICTABLE));
 	seq_printf(m, "unevictable=%lu", unevictable_nr);
 	for_each_node_state(nid, N_HIGH_MEMORY) {
-		node_nr = mem_cgroup_node_nr_unevictable_lru_pages(mem_cont,
-									nid);
+		node_nr = mem_cgroup_node_nr_lru_pages(mem_cont, nid,
+				BIT(LRU_UNEVICTABLE));
 		seq_printf(m, " N%d=%lu", nid, node_nr);
 	}
 	seq_putc(m, '\n');
@@ -4222,7 +4333,7 @@ static u64 mem_cgroup_swappiness_read(struct cgroup *cgrp, struct cftype *cft)
 {
 	struct mem_cgroup *memcg = mem_cgroup_from_cont(cgrp);
 
-	return get_swappiness(memcg);
+	return mem_cgroup_swappiness(memcg);
 }
 
 static int mem_cgroup_swappiness_write(struct cgroup *cgrp, struct cftype *cft,
@@ -4512,15 +4623,15 @@ static int mem_cgroup_oom_register_event(struct cgroup *cgrp,
 	if (!event)
 		return -ENOMEM;
 
-	mutex_lock(&memcg_oom_mutex);
+	spin_lock(&memcg_oom_lock);
 
 	event->eventfd = eventfd;
 	list_add(&event->list, &memcg->oom_notify);
 
 	/* already in OOM ? */
-	if (atomic_read(&memcg->oom_lock))
+	if (atomic_read(&memcg->under_oom))
 		eventfd_signal(eventfd, 1);
-	mutex_unlock(&memcg_oom_mutex);
+	spin_unlock(&memcg_oom_lock);
 
 	return 0;
 }
@@ -4534,7 +4645,7 @@ static void mem_cgroup_oom_unregister_event(struct cgroup *cgrp,
 
 	BUG_ON(type != _OOM_TYPE);
 
-	mutex_lock(&memcg_oom_mutex);
+	spin_lock(&memcg_oom_lock);
 
 	list_for_each_entry_safe(ev, tmp, &mem->oom_notify, list) {
 		if (ev->eventfd == eventfd) {
@@ -4543,7 +4654,7 @@ static void mem_cgroup_oom_unregister_event(struct cgroup *cgrp,
 		}
 	}
 
-	mutex_unlock(&memcg_oom_mutex);
+	spin_unlock(&memcg_oom_lock);
 }
 
 static int mem_cgroup_oom_control_read(struct cgroup *cgrp,
@@ -4553,7 +4664,7 @@ static int mem_cgroup_oom_control_read(struct cgroup *cgrp,
 
 	cb->fill(cb, "oom_kill_disable", mem->oom_kill_disable);
 
-	if (atomic_read(&mem->oom_lock))
+	if (atomic_read(&mem->under_oom))
 		cb->fill(cb, "under_oom", 1);
 	else
 		cb->fill(cb, "under_oom", 0);
@@ -4602,6 +4713,54 @@ static int mem_control_numa_stat_open(struct inode *unused, struct file *file)
 }
 #endif /* CONFIG_NUMA */
 
+static int mem_cgroup_vmscan_stat_read(struct cgroup *cgrp,
+				struct cftype *cft,
+				struct cgroup_map_cb *cb)
+{
+	struct mem_cgroup *mem = mem_cgroup_from_cont(cgrp);
+	char string[64];
+	int i;
+
+	for (i = 0; i < NR_SCANSTATS; i++) {
+		strcpy(string, scanstat_string[i]);
+		strcat(string, SCANSTAT_WORD_LIMIT);
+		cb->fill(cb, string,  mem->scanstat.stats[SCAN_BY_LIMIT][i]);
+	}
+
+	for (i = 0; i < NR_SCANSTATS; i++) {
+		strcpy(string, scanstat_string[i]);
+		strcat(string, SCANSTAT_WORD_SYSTEM);
+		cb->fill(cb, string,  mem->scanstat.stats[SCAN_BY_SYSTEM][i]);
+	}
+
+	for (i = 0; i < NR_SCANSTATS; i++) {
+		strcpy(string, scanstat_string[i]);
+		strcat(string, SCANSTAT_WORD_LIMIT);
+		strcat(string, SCANSTAT_WORD_HIERARCHY);
+		cb->fill(cb, string,  mem->scanstat.rootstats[SCAN_BY_LIMIT][i]);
+	}
+	for (i = 0; i < NR_SCANSTATS; i++) {
+		strcpy(string, scanstat_string[i]);
+		strcat(string, SCANSTAT_WORD_SYSTEM);
+		strcat(string, SCANSTAT_WORD_HIERARCHY);
+		cb->fill(cb, string,  mem->scanstat.rootstats[SCAN_BY_SYSTEM][i]);
+	}
+	return 0;
+}
+
+static int mem_cgroup_reset_vmscan_stat(struct cgroup *cgrp,
+				unsigned int event)
+{
+	struct mem_cgroup *mem = mem_cgroup_from_cont(cgrp);
+
+	spin_lock(&mem->scanstat.lock);
+	memset(&mem->scanstat.stats, 0, sizeof(mem->scanstat.stats));
+	memset(&mem->scanstat.rootstats, 0, sizeof(mem->scanstat.rootstats));
+	spin_unlock(&mem->scanstat.lock);
+	return 0;
+}
+
+
 static struct cftype mem_cgroup_files[] = {
 	{
 		.name = "usage_in_bytes",
@@ -4672,6 +4831,11 @@ static struct cftype mem_cgroup_files[] = {
 		.mode = S_IRUGO,
 	},
 #endif
+	{
+		.name = "vmscan_stat",
+		.read_map = mem_cgroup_vmscan_stat_read,
+		.trigger = mem_cgroup_reset_vmscan_stat,
+	},
 };
 
 #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP
@@ -4931,10 +5095,11 @@ mem_cgroup_create(struct cgroup_subsys *ss, struct cgroup *cont)
 	INIT_LIST_HEAD(&mem->oom_notify);
 
 	if (parent)
-		mem->swappiness = get_swappiness(parent);
+		mem->swappiness = mem_cgroup_swappiness(parent);
 	atomic_set(&mem->refcnt, 1);
 	mem->move_charge_at_immigrate = 0;
 	mutex_init(&mem->thresholds_lock);
+	spin_lock_init(&mem->scanstat.lock);
 	return &mem->css;
 free_out:
 	__mem_cgroup_free(mem);
@@ -5115,15 +5280,17 @@ static struct page *mc_handle_file_pte(struct vm_area_struct *vma,
 		pgoff = pte_to_pgoff(ptent);
 
 	/* page is moved even if it's not RSS of this task(page-faulted). */
-	if (!mapping_cap_swap_backed(mapping)) { /* normal file */
-		page = find_get_page(mapping, pgoff);
-	} else { /* shmem/tmpfs file. we should take account of swap too. */
-		swp_entry_t ent;
-		mem_cgroup_get_shmem_target(inode, pgoff, &page, &ent);
+	page = find_get_page(mapping, pgoff);
+
+#ifdef CONFIG_SWAP
+	/* shmem/tmpfs may report page out on swap: account for that too. */
+	if (radix_tree_exceptional_entry(page)) {
+		swp_entry_t swap = radix_to_swp_entry(page);
 		if (do_swap_account)
-			entry->val = ent.val;
+			*entry = swap;
+		page = find_get_page(&swapper_space, swap.val);
 	}
-
+#endif
 	return page;
 }