v4.19.13 snapshot.
diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h
new file mode 100644
index 0000000..652f602
--- /dev/null
+++ b/include/linux/memcontrol.h
@@ -0,0 +1,1335 @@
+/* memcontrol.h - Memory Controller
+ *
+ * Copyright IBM Corporation, 2007
+ * Author Balbir Singh <balbir@linux.vnet.ibm.com>
+ *
+ * Copyright 2007 OpenVZ SWsoft Inc
+ * Author: Pavel Emelianov <xemul@openvz.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#ifndef _LINUX_MEMCONTROL_H
+#define _LINUX_MEMCONTROL_H
+#include <linux/cgroup.h>
+#include <linux/vm_event_item.h>
+#include <linux/hardirq.h>
+#include <linux/jump_label.h>
+#include <linux/page_counter.h>
+#include <linux/vmpressure.h>
+#include <linux/eventfd.h>
+#include <linux/mm.h>
+#include <linux/vmstat.h>
+#include <linux/writeback.h>
+#include <linux/page-flags.h>
+
+struct mem_cgroup;
+struct page;
+struct mm_struct;
+struct kmem_cache;
+
+/* Cgroup-specific page state, on top of universal node page state */
+enum memcg_stat_item {
+	MEMCG_CACHE = NR_VM_NODE_STAT_ITEMS,
+	MEMCG_RSS,
+	MEMCG_RSS_HUGE,
+	MEMCG_SWAP,
+	MEMCG_SOCK,
+	/* XXX: why are these zone and not node counters? */
+	MEMCG_KERNEL_STACK_KB,
+	MEMCG_NR_STAT,
+};
+
+enum memcg_memory_event {
+	MEMCG_LOW,
+	MEMCG_HIGH,
+	MEMCG_MAX,
+	MEMCG_OOM,
+	MEMCG_OOM_KILL,
+	MEMCG_SWAP_MAX,
+	MEMCG_SWAP_FAIL,
+	MEMCG_NR_MEMORY_EVENTS,
+};
+
+enum mem_cgroup_protection {
+	MEMCG_PROT_NONE,
+	MEMCG_PROT_LOW,
+	MEMCG_PROT_MIN,
+};
+
+struct mem_cgroup_reclaim_cookie {
+	pg_data_t *pgdat;
+	int priority;
+	unsigned int generation;
+};
+
+#ifdef CONFIG_MEMCG
+
+#define MEM_CGROUP_ID_SHIFT	16
+#define MEM_CGROUP_ID_MAX	USHRT_MAX
+
+struct mem_cgroup_id {
+	int id;
+	atomic_t ref;
+};
+
+/*
+ * Per memcg event counter is incremented at every pagein/pageout. With THP,
+ * it will be incremated by the number of pages. This counter is used for
+ * for trigger some periodic events. This is straightforward and better
+ * than using jiffies etc. to handle periodic memcg event.
+ */
+enum mem_cgroup_events_target {
+	MEM_CGROUP_TARGET_THRESH,
+	MEM_CGROUP_TARGET_SOFTLIMIT,
+	MEM_CGROUP_TARGET_NUMAINFO,
+	MEM_CGROUP_NTARGETS,
+};
+
+struct mem_cgroup_stat_cpu {
+	long count[MEMCG_NR_STAT];
+	unsigned long events[NR_VM_EVENT_ITEMS];
+	unsigned long nr_page_events;
+	unsigned long targets[MEM_CGROUP_NTARGETS];
+};
+
+struct mem_cgroup_reclaim_iter {
+	struct mem_cgroup *position;
+	/* scan generation, increased every round-trip */
+	unsigned int generation;
+};
+
+struct lruvec_stat {
+	long count[NR_VM_NODE_STAT_ITEMS];
+};
+
+/*
+ * Bitmap of shrinker::id corresponding to memcg-aware shrinkers,
+ * which have elements charged to this memcg.
+ */
+struct memcg_shrinker_map {
+	struct rcu_head rcu;
+	unsigned long map[0];
+};
+
+/*
+ * per-zone information in memory controller.
+ */
+struct mem_cgroup_per_node {
+	struct lruvec		lruvec;
+
+	struct lruvec_stat __percpu *lruvec_stat_cpu;
+	atomic_long_t		lruvec_stat[NR_VM_NODE_STAT_ITEMS];
+
+	unsigned long		lru_zone_size[MAX_NR_ZONES][NR_LRU_LISTS];
+
+	struct mem_cgroup_reclaim_iter	iter[DEF_PRIORITY + 1];
+
+#ifdef CONFIG_MEMCG_KMEM
+	struct memcg_shrinker_map __rcu	*shrinker_map;
+#endif
+	struct rb_node		tree_node;	/* RB tree node */
+	unsigned long		usage_in_excess;/* Set to the value by which */
+						/* the soft limit is exceeded*/
+	bool			on_tree;
+	bool			congested;	/* memcg has many dirty pages */
+						/* backed by a congested BDI */
+
+	struct mem_cgroup	*memcg;		/* Back pointer, we cannot */
+						/* use container_of	   */
+};
+
+struct mem_cgroup_threshold {
+	struct eventfd_ctx *eventfd;
+	unsigned long threshold;
+};
+
+/* For threshold */
+struct mem_cgroup_threshold_ary {
+	/* An array index points to threshold just below or equal to usage. */
+	int current_threshold;
+	/* Size of entries[] */
+	unsigned int size;
+	/* Array of thresholds */
+	struct mem_cgroup_threshold entries[0];
+};
+
+struct mem_cgroup_thresholds {
+	/* Primary thresholds array */
+	struct mem_cgroup_threshold_ary *primary;
+	/*
+	 * Spare threshold array.
+	 * This is needed to make mem_cgroup_unregister_event() "never fail".
+	 * It must be able to store at least primary->size - 1 entries.
+	 */
+	struct mem_cgroup_threshold_ary *spare;
+};
+
+enum memcg_kmem_state {
+	KMEM_NONE,
+	KMEM_ALLOCATED,
+	KMEM_ONLINE,
+};
+
+#if defined(CONFIG_SMP)
+struct memcg_padding {
+	char x[0];
+} ____cacheline_internodealigned_in_smp;
+#define MEMCG_PADDING(name)      struct memcg_padding name;
+#else
+#define MEMCG_PADDING(name)
+#endif
+
+/*
+ * The memory controller data structure. The memory controller controls both
+ * page cache and RSS per cgroup. We would eventually like to provide
+ * statistics based on the statistics developed by Rik Van Riel for clock-pro,
+ * to help the administrator determine what knobs to tune.
+ */
+struct mem_cgroup {
+	struct cgroup_subsys_state css;
+
+	/* Private memcg ID. Used to ID objects that outlive the cgroup */
+	struct mem_cgroup_id id;
+
+	/* Accounted resources */
+	struct page_counter memory;
+	struct page_counter swap;
+
+	/* Legacy consumer-oriented counters */
+	struct page_counter memsw;
+	struct page_counter kmem;
+	struct page_counter tcpmem;
+
+	/* Upper bound of normal memory consumption range */
+	unsigned long high;
+
+	/* Range enforcement for interrupt charges */
+	struct work_struct high_work;
+
+	unsigned long soft_limit;
+
+	/* vmpressure notifications */
+	struct vmpressure vmpressure;
+
+	/*
+	 * Should the accounting and control be hierarchical, per subtree?
+	 */
+	bool use_hierarchy;
+
+	/*
+	 * Should the OOM killer kill all belonging tasks, had it kill one?
+	 */
+	bool oom_group;
+
+	/* protected by memcg_oom_lock */
+	bool		oom_lock;
+	int		under_oom;
+
+	int	swappiness;
+	/* OOM-Killer disable */
+	int		oom_kill_disable;
+
+	/* memory.events */
+	struct cgroup_file events_file;
+
+	/* handle for "memory.swap.events" */
+	struct cgroup_file swap_events_file;
+
+	/* protect arrays of thresholds */
+	struct mutex thresholds_lock;
+
+	/* thresholds for memory usage. RCU-protected */
+	struct mem_cgroup_thresholds thresholds;
+
+	/* thresholds for mem+swap usage. RCU-protected */
+	struct mem_cgroup_thresholds memsw_thresholds;
+
+	/* For oom notifier event fd */
+	struct list_head oom_notify;
+
+	/*
+	 * Should we move charges of a task when a task is moved into this
+	 * mem_cgroup ? And what type of charges should we move ?
+	 */
+	unsigned long move_charge_at_immigrate;
+	/* taken only while moving_account > 0 */
+	spinlock_t		move_lock;
+	unsigned long		move_lock_flags;
+
+	MEMCG_PADDING(_pad1_);
+
+	/*
+	 * set > 0 if pages under this cgroup are moving to other cgroup.
+	 */
+	atomic_t		moving_account;
+	struct task_struct	*move_lock_task;
+
+	/* memory.stat */
+	struct mem_cgroup_stat_cpu __percpu *stat_cpu;
+
+	MEMCG_PADDING(_pad2_);
+
+	atomic_long_t		stat[MEMCG_NR_STAT];
+	atomic_long_t		events[NR_VM_EVENT_ITEMS];
+	atomic_long_t memory_events[MEMCG_NR_MEMORY_EVENTS];
+
+	unsigned long		socket_pressure;
+
+	/* Legacy tcp memory accounting */
+	bool			tcpmem_active;
+	int			tcpmem_pressure;
+
+#ifdef CONFIG_MEMCG_KMEM
+        /* Index in the kmem_cache->memcg_params.memcg_caches array */
+	int kmemcg_id;
+	enum memcg_kmem_state kmem_state;
+	struct list_head kmem_caches;
+#endif
+
+	int last_scanned_node;
+#if MAX_NUMNODES > 1
+	nodemask_t	scan_nodes;
+	atomic_t	numainfo_events;
+	atomic_t	numainfo_updating;
+#endif
+
+#ifdef CONFIG_CGROUP_WRITEBACK
+	struct list_head cgwb_list;
+	struct wb_domain cgwb_domain;
+#endif
+
+	/* List of events which userspace want to receive */
+	struct list_head event_list;
+	spinlock_t event_list_lock;
+
+	struct mem_cgroup_per_node *nodeinfo[0];
+	/* WARNING: nodeinfo must be the last member here */
+};
+
+/*
+ * size of first charge trial. "32" comes from vmscan.c's magic value.
+ * TODO: maybe necessary to use big numbers in big irons.
+ */
+#define MEMCG_CHARGE_BATCH 32U
+
+extern struct mem_cgroup *root_mem_cgroup;
+
+static inline bool mem_cgroup_is_root(struct mem_cgroup *memcg)
+{
+	return (memcg == root_mem_cgroup);
+}
+
+static inline bool mem_cgroup_disabled(void)
+{
+	return !cgroup_subsys_enabled(memory_cgrp_subsys);
+}
+
+enum mem_cgroup_protection mem_cgroup_protected(struct mem_cgroup *root,
+						struct mem_cgroup *memcg);
+
+int mem_cgroup_try_charge(struct page *page, struct mm_struct *mm,
+			  gfp_t gfp_mask, struct mem_cgroup **memcgp,
+			  bool compound);
+int mem_cgroup_try_charge_delay(struct page *page, struct mm_struct *mm,
+			  gfp_t gfp_mask, struct mem_cgroup **memcgp,
+			  bool compound);
+void mem_cgroup_commit_charge(struct page *page, struct mem_cgroup *memcg,
+			      bool lrucare, bool compound);
+void mem_cgroup_cancel_charge(struct page *page, struct mem_cgroup *memcg,
+		bool compound);
+void mem_cgroup_uncharge(struct page *page);
+void mem_cgroup_uncharge_list(struct list_head *page_list);
+
+void mem_cgroup_migrate(struct page *oldpage, struct page *newpage);
+
+static struct mem_cgroup_per_node *
+mem_cgroup_nodeinfo(struct mem_cgroup *memcg, int nid)
+{
+	return memcg->nodeinfo[nid];
+}
+
+/**
+ * mem_cgroup_lruvec - get the lru list vector for a node or a memcg zone
+ * @node: node of the wanted lruvec
+ * @memcg: memcg of the wanted lruvec
+ *
+ * Returns the lru list vector holding pages for a given @node or a given
+ * @memcg and @zone. This can be the node lruvec, if the memory controller
+ * is disabled.
+ */
+static inline struct lruvec *mem_cgroup_lruvec(struct pglist_data *pgdat,
+				struct mem_cgroup *memcg)
+{
+	struct mem_cgroup_per_node *mz;
+	struct lruvec *lruvec;
+
+	if (mem_cgroup_disabled()) {
+		lruvec = node_lruvec(pgdat);
+		goto out;
+	}
+
+	mz = mem_cgroup_nodeinfo(memcg, pgdat->node_id);
+	lruvec = &mz->lruvec;
+out:
+	/*
+	 * Since a node can be onlined after the mem_cgroup was created,
+	 * we have to be prepared to initialize lruvec->pgdat here;
+	 * and if offlined then reonlined, we need to reinitialize it.
+	 */
+	if (unlikely(lruvec->pgdat != pgdat))
+		lruvec->pgdat = pgdat;
+	return lruvec;
+}
+
+struct lruvec *mem_cgroup_page_lruvec(struct page *, struct pglist_data *);
+
+bool task_in_mem_cgroup(struct task_struct *task, struct mem_cgroup *memcg);
+struct mem_cgroup *mem_cgroup_from_task(struct task_struct *p);
+
+struct mem_cgroup *get_mem_cgroup_from_mm(struct mm_struct *mm);
+
+struct mem_cgroup *get_mem_cgroup_from_page(struct page *page);
+
+static inline
+struct mem_cgroup *mem_cgroup_from_css(struct cgroup_subsys_state *css){
+	return css ? container_of(css, struct mem_cgroup, css) : NULL;
+}
+
+static inline void mem_cgroup_put(struct mem_cgroup *memcg)
+{
+	if (memcg)
+		css_put(&memcg->css);
+}
+
+#define mem_cgroup_from_counter(counter, member)	\
+	container_of(counter, struct mem_cgroup, member)
+
+struct mem_cgroup *mem_cgroup_iter(struct mem_cgroup *,
+				   struct mem_cgroup *,
+				   struct mem_cgroup_reclaim_cookie *);
+void mem_cgroup_iter_break(struct mem_cgroup *, struct mem_cgroup *);
+int mem_cgroup_scan_tasks(struct mem_cgroup *,
+			  int (*)(struct task_struct *, void *), void *);
+
+static inline unsigned short mem_cgroup_id(struct mem_cgroup *memcg)
+{
+	if (mem_cgroup_disabled())
+		return 0;
+
+	return memcg->id.id;
+}
+struct mem_cgroup *mem_cgroup_from_id(unsigned short id);
+
+static inline struct mem_cgroup *lruvec_memcg(struct lruvec *lruvec)
+{
+	struct mem_cgroup_per_node *mz;
+
+	if (mem_cgroup_disabled())
+		return NULL;
+
+	mz = container_of(lruvec, struct mem_cgroup_per_node, lruvec);
+	return mz->memcg;
+}
+
+/**
+ * parent_mem_cgroup - find the accounting parent of a memcg
+ * @memcg: memcg whose parent to find
+ *
+ * Returns the parent memcg, or NULL if this is the root or the memory
+ * controller is in legacy no-hierarchy mode.
+ */
+static inline struct mem_cgroup *parent_mem_cgroup(struct mem_cgroup *memcg)
+{
+	if (!memcg->memory.parent)
+		return NULL;
+	return mem_cgroup_from_counter(memcg->memory.parent, memory);
+}
+
+static inline bool mem_cgroup_is_descendant(struct mem_cgroup *memcg,
+			      struct mem_cgroup *root)
+{
+	if (root == memcg)
+		return true;
+	if (!root->use_hierarchy)
+		return false;
+	return cgroup_is_descendant(memcg->css.cgroup, root->css.cgroup);
+}
+
+static inline bool mm_match_cgroup(struct mm_struct *mm,
+				   struct mem_cgroup *memcg)
+{
+	struct mem_cgroup *task_memcg;
+	bool match = false;
+
+	rcu_read_lock();
+	task_memcg = mem_cgroup_from_task(rcu_dereference(mm->owner));
+	if (task_memcg)
+		match = mem_cgroup_is_descendant(task_memcg, memcg);
+	rcu_read_unlock();
+	return match;
+}
+
+struct cgroup_subsys_state *mem_cgroup_css_from_page(struct page *page);
+ino_t page_cgroup_ino(struct page *page);
+
+static inline bool mem_cgroup_online(struct mem_cgroup *memcg)
+{
+	if (mem_cgroup_disabled())
+		return true;
+	return !!(memcg->css.flags & CSS_ONLINE);
+}
+
+/*
+ * For memory reclaim.
+ */
+int mem_cgroup_select_victim_node(struct mem_cgroup *memcg);
+
+void mem_cgroup_update_lru_size(struct lruvec *lruvec, enum lru_list lru,
+		int zid, int nr_pages);
+
+unsigned long mem_cgroup_node_nr_lru_pages(struct mem_cgroup *memcg,
+					   int nid, unsigned int lru_mask);
+
+static inline
+unsigned long mem_cgroup_get_lru_size(struct lruvec *lruvec, enum lru_list lru)
+{
+	struct mem_cgroup_per_node *mz;
+	unsigned long nr_pages = 0;
+	int zid;
+
+	mz = container_of(lruvec, struct mem_cgroup_per_node, lruvec);
+	for (zid = 0; zid < MAX_NR_ZONES; zid++)
+		nr_pages += mz->lru_zone_size[zid][lru];
+	return nr_pages;
+}
+
+static inline
+unsigned long mem_cgroup_get_zone_lru_size(struct lruvec *lruvec,
+		enum lru_list lru, int zone_idx)
+{
+	struct mem_cgroup_per_node *mz;
+
+	mz = container_of(lruvec, struct mem_cgroup_per_node, lruvec);
+	return mz->lru_zone_size[zone_idx][lru];
+}
+
+void mem_cgroup_handle_over_high(void);
+
+unsigned long mem_cgroup_get_max(struct mem_cgroup *memcg);
+
+void mem_cgroup_print_oom_info(struct mem_cgroup *memcg,
+				struct task_struct *p);
+
+static inline void mem_cgroup_enter_user_fault(void)
+{
+	WARN_ON(current->in_user_fault);
+	current->in_user_fault = 1;
+}
+
+static inline void mem_cgroup_exit_user_fault(void)
+{
+	WARN_ON(!current->in_user_fault);
+	current->in_user_fault = 0;
+}
+
+static inline bool task_in_memcg_oom(struct task_struct *p)
+{
+	return p->memcg_in_oom;
+}
+
+bool mem_cgroup_oom_synchronize(bool wait);
+struct mem_cgroup *mem_cgroup_get_oom_group(struct task_struct *victim,
+					    struct mem_cgroup *oom_domain);
+void mem_cgroup_print_oom_group(struct mem_cgroup *memcg);
+
+#ifdef CONFIG_MEMCG_SWAP
+extern int do_swap_account;
+#endif
+
+struct mem_cgroup *lock_page_memcg(struct page *page);
+void __unlock_page_memcg(struct mem_cgroup *memcg);
+void unlock_page_memcg(struct page *page);
+
+/* idx can be of type enum memcg_stat_item or node_stat_item */
+static inline unsigned long memcg_page_state(struct mem_cgroup *memcg,
+					     int idx)
+{
+	long x = atomic_long_read(&memcg->stat[idx]);
+#ifdef CONFIG_SMP
+	if (x < 0)
+		x = 0;
+#endif
+	return x;
+}
+
+/* idx can be of type enum memcg_stat_item or node_stat_item */
+static inline void __mod_memcg_state(struct mem_cgroup *memcg,
+				     int idx, int val)
+{
+	long x;
+
+	if (mem_cgroup_disabled())
+		return;
+
+	x = val + __this_cpu_read(memcg->stat_cpu->count[idx]);
+	if (unlikely(abs(x) > MEMCG_CHARGE_BATCH)) {
+		atomic_long_add(x, &memcg->stat[idx]);
+		x = 0;
+	}
+	__this_cpu_write(memcg->stat_cpu->count[idx], x);
+}
+
+/* idx can be of type enum memcg_stat_item or node_stat_item */
+static inline void mod_memcg_state(struct mem_cgroup *memcg,
+				   int idx, int val)
+{
+	unsigned long flags;
+
+	local_irq_save(flags);
+	__mod_memcg_state(memcg, idx, val);
+	local_irq_restore(flags);
+}
+
+/**
+ * mod_memcg_page_state - update page state statistics
+ * @page: the page
+ * @idx: page state item to account
+ * @val: number of pages (positive or negative)
+ *
+ * The @page must be locked or the caller must use lock_page_memcg()
+ * to prevent double accounting when the page is concurrently being
+ * moved to another memcg:
+ *
+ *   lock_page(page) or lock_page_memcg(page)
+ *   if (TestClearPageState(page))
+ *     mod_memcg_page_state(page, state, -1);
+ *   unlock_page(page) or unlock_page_memcg(page)
+ *
+ * Kernel pages are an exception to this, since they'll never move.
+ */
+static inline void __mod_memcg_page_state(struct page *page,
+					  int idx, int val)
+{
+	if (page->mem_cgroup)
+		__mod_memcg_state(page->mem_cgroup, idx, val);
+}
+
+static inline void mod_memcg_page_state(struct page *page,
+					int idx, int val)
+{
+	if (page->mem_cgroup)
+		mod_memcg_state(page->mem_cgroup, idx, val);
+}
+
+static inline unsigned long lruvec_page_state(struct lruvec *lruvec,
+					      enum node_stat_item idx)
+{
+	struct mem_cgroup_per_node *pn;
+	long x;
+
+	if (mem_cgroup_disabled())
+		return node_page_state(lruvec_pgdat(lruvec), idx);
+
+	pn = container_of(lruvec, struct mem_cgroup_per_node, lruvec);
+	x = atomic_long_read(&pn->lruvec_stat[idx]);
+#ifdef CONFIG_SMP
+	if (x < 0)
+		x = 0;
+#endif
+	return x;
+}
+
+static inline void __mod_lruvec_state(struct lruvec *lruvec,
+				      enum node_stat_item idx, int val)
+{
+	struct mem_cgroup_per_node *pn;
+	long x;
+
+	/* Update node */
+	__mod_node_page_state(lruvec_pgdat(lruvec), idx, val);
+
+	if (mem_cgroup_disabled())
+		return;
+
+	pn = container_of(lruvec, struct mem_cgroup_per_node, lruvec);
+
+	/* Update memcg */
+	__mod_memcg_state(pn->memcg, idx, val);
+
+	/* Update lruvec */
+	x = val + __this_cpu_read(pn->lruvec_stat_cpu->count[idx]);
+	if (unlikely(abs(x) > MEMCG_CHARGE_BATCH)) {
+		atomic_long_add(x, &pn->lruvec_stat[idx]);
+		x = 0;
+	}
+	__this_cpu_write(pn->lruvec_stat_cpu->count[idx], x);
+}
+
+static inline void mod_lruvec_state(struct lruvec *lruvec,
+				    enum node_stat_item idx, int val)
+{
+	unsigned long flags;
+
+	local_irq_save(flags);
+	__mod_lruvec_state(lruvec, idx, val);
+	local_irq_restore(flags);
+}
+
+static inline void __mod_lruvec_page_state(struct page *page,
+					   enum node_stat_item idx, int val)
+{
+	pg_data_t *pgdat = page_pgdat(page);
+	struct lruvec *lruvec;
+
+	/* Untracked pages have no memcg, no lruvec. Update only the node */
+	if (!page->mem_cgroup) {
+		__mod_node_page_state(pgdat, idx, val);
+		return;
+	}
+
+	lruvec = mem_cgroup_lruvec(pgdat, page->mem_cgroup);
+	__mod_lruvec_state(lruvec, idx, val);
+}
+
+static inline void mod_lruvec_page_state(struct page *page,
+					 enum node_stat_item idx, int val)
+{
+	unsigned long flags;
+
+	local_irq_save(flags);
+	__mod_lruvec_page_state(page, idx, val);
+	local_irq_restore(flags);
+}
+
+unsigned long mem_cgroup_soft_limit_reclaim(pg_data_t *pgdat, int order,
+						gfp_t gfp_mask,
+						unsigned long *total_scanned);
+
+static inline void __count_memcg_events(struct mem_cgroup *memcg,
+					enum vm_event_item idx,
+					unsigned long count)
+{
+	unsigned long x;
+
+	if (mem_cgroup_disabled())
+		return;
+
+	x = count + __this_cpu_read(memcg->stat_cpu->events[idx]);
+	if (unlikely(x > MEMCG_CHARGE_BATCH)) {
+		atomic_long_add(x, &memcg->events[idx]);
+		x = 0;
+	}
+	__this_cpu_write(memcg->stat_cpu->events[idx], x);
+}
+
+static inline void count_memcg_events(struct mem_cgroup *memcg,
+				      enum vm_event_item idx,
+				      unsigned long count)
+{
+	unsigned long flags;
+
+	local_irq_save(flags);
+	__count_memcg_events(memcg, idx, count);
+	local_irq_restore(flags);
+}
+
+static inline void count_memcg_page_event(struct page *page,
+					  enum vm_event_item idx)
+{
+	if (page->mem_cgroup)
+		count_memcg_events(page->mem_cgroup, idx, 1);
+}
+
+static inline void count_memcg_event_mm(struct mm_struct *mm,
+					enum vm_event_item idx)
+{
+	struct mem_cgroup *memcg;
+
+	if (mem_cgroup_disabled())
+		return;
+
+	rcu_read_lock();
+	memcg = mem_cgroup_from_task(rcu_dereference(mm->owner));
+	if (likely(memcg))
+		count_memcg_events(memcg, idx, 1);
+	rcu_read_unlock();
+}
+
+static inline void memcg_memory_event(struct mem_cgroup *memcg,
+				      enum memcg_memory_event event)
+{
+	atomic_long_inc(&memcg->memory_events[event]);
+	cgroup_file_notify(&memcg->events_file);
+}
+
+static inline void memcg_memory_event_mm(struct mm_struct *mm,
+					 enum memcg_memory_event event)
+{
+	struct mem_cgroup *memcg;
+
+	if (mem_cgroup_disabled())
+		return;
+
+	rcu_read_lock();
+	memcg = mem_cgroup_from_task(rcu_dereference(mm->owner));
+	if (likely(memcg))
+		memcg_memory_event(memcg, event);
+	rcu_read_unlock();
+}
+
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE
+void mem_cgroup_split_huge_fixup(struct page *head);
+#endif
+
+#else /* CONFIG_MEMCG */
+
+#define MEM_CGROUP_ID_SHIFT	0
+#define MEM_CGROUP_ID_MAX	0
+
+struct mem_cgroup;
+
+static inline bool mem_cgroup_is_root(struct mem_cgroup *memcg)
+{
+	return true;
+}
+
+static inline bool mem_cgroup_disabled(void)
+{
+	return true;
+}
+
+static inline void memcg_memory_event(struct mem_cgroup *memcg,
+				      enum memcg_memory_event event)
+{
+}
+
+static inline void memcg_memory_event_mm(struct mm_struct *mm,
+					 enum memcg_memory_event event)
+{
+}
+
+static inline enum mem_cgroup_protection mem_cgroup_protected(
+	struct mem_cgroup *root, struct mem_cgroup *memcg)
+{
+	return MEMCG_PROT_NONE;
+}
+
+static inline int mem_cgroup_try_charge(struct page *page, struct mm_struct *mm,
+					gfp_t gfp_mask,
+					struct mem_cgroup **memcgp,
+					bool compound)
+{
+	*memcgp = NULL;
+	return 0;
+}
+
+static inline int mem_cgroup_try_charge_delay(struct page *page,
+					      struct mm_struct *mm,
+					      gfp_t gfp_mask,
+					      struct mem_cgroup **memcgp,
+					      bool compound)
+{
+	*memcgp = NULL;
+	return 0;
+}
+
+static inline void mem_cgroup_commit_charge(struct page *page,
+					    struct mem_cgroup *memcg,
+					    bool lrucare, bool compound)
+{
+}
+
+static inline void mem_cgroup_cancel_charge(struct page *page,
+					    struct mem_cgroup *memcg,
+					    bool compound)
+{
+}
+
+static inline void mem_cgroup_uncharge(struct page *page)
+{
+}
+
+static inline void mem_cgroup_uncharge_list(struct list_head *page_list)
+{
+}
+
+static inline void mem_cgroup_migrate(struct page *old, struct page *new)
+{
+}
+
+static inline struct lruvec *mem_cgroup_lruvec(struct pglist_data *pgdat,
+				struct mem_cgroup *memcg)
+{
+	return node_lruvec(pgdat);
+}
+
+static inline struct lruvec *mem_cgroup_page_lruvec(struct page *page,
+						    struct pglist_data *pgdat)
+{
+	return &pgdat->lruvec;
+}
+
+static inline bool mm_match_cgroup(struct mm_struct *mm,
+		struct mem_cgroup *memcg)
+{
+	return true;
+}
+
+static inline bool task_in_mem_cgroup(struct task_struct *task,
+				      const struct mem_cgroup *memcg)
+{
+	return true;
+}
+
+static inline struct mem_cgroup *get_mem_cgroup_from_mm(struct mm_struct *mm)
+{
+	return NULL;
+}
+
+static inline struct mem_cgroup *get_mem_cgroup_from_page(struct page *page)
+{
+	return NULL;
+}
+
+static inline void mem_cgroup_put(struct mem_cgroup *memcg)
+{
+}
+
+static inline struct mem_cgroup *
+mem_cgroup_iter(struct mem_cgroup *root,
+		struct mem_cgroup *prev,
+		struct mem_cgroup_reclaim_cookie *reclaim)
+{
+	return NULL;
+}
+
+static inline void mem_cgroup_iter_break(struct mem_cgroup *root,
+					 struct mem_cgroup *prev)
+{
+}
+
+static inline int mem_cgroup_scan_tasks(struct mem_cgroup *memcg,
+		int (*fn)(struct task_struct *, void *), void *arg)
+{
+	return 0;
+}
+
+static inline unsigned short mem_cgroup_id(struct mem_cgroup *memcg)
+{
+	return 0;
+}
+
+static inline struct mem_cgroup *mem_cgroup_from_id(unsigned short id)
+{
+	WARN_ON_ONCE(id);
+	/* XXX: This should always return root_mem_cgroup */
+	return NULL;
+}
+
+static inline struct mem_cgroup *lruvec_memcg(struct lruvec *lruvec)
+{
+	return NULL;
+}
+
+static inline bool mem_cgroup_online(struct mem_cgroup *memcg)
+{
+	return true;
+}
+
+static inline unsigned long
+mem_cgroup_get_lru_size(struct lruvec *lruvec, enum lru_list lru)
+{
+	return 0;
+}
+static inline
+unsigned long mem_cgroup_get_zone_lru_size(struct lruvec *lruvec,
+		enum lru_list lru, int zone_idx)
+{
+	return 0;
+}
+
+static inline unsigned long
+mem_cgroup_node_nr_lru_pages(struct mem_cgroup *memcg,
+			     int nid, unsigned int lru_mask)
+{
+	return 0;
+}
+
+static inline unsigned long mem_cgroup_get_max(struct mem_cgroup *memcg)
+{
+	return 0;
+}
+
+static inline void
+mem_cgroup_print_oom_info(struct mem_cgroup *memcg, struct task_struct *p)
+{
+}
+
+static inline struct mem_cgroup *lock_page_memcg(struct page *page)
+{
+	return NULL;
+}
+
+static inline void __unlock_page_memcg(struct mem_cgroup *memcg)
+{
+}
+
+static inline void unlock_page_memcg(struct page *page)
+{
+}
+
+static inline void mem_cgroup_handle_over_high(void)
+{
+}
+
+static inline void mem_cgroup_enter_user_fault(void)
+{
+}
+
+static inline void mem_cgroup_exit_user_fault(void)
+{
+}
+
+static inline bool task_in_memcg_oom(struct task_struct *p)
+{
+	return false;
+}
+
+static inline bool mem_cgroup_oom_synchronize(bool wait)
+{
+	return false;
+}
+
+static inline struct mem_cgroup *mem_cgroup_get_oom_group(
+	struct task_struct *victim, struct mem_cgroup *oom_domain)
+{
+	return NULL;
+}
+
+static inline void mem_cgroup_print_oom_group(struct mem_cgroup *memcg)
+{
+}
+
+static inline unsigned long memcg_page_state(struct mem_cgroup *memcg,
+					     int idx)
+{
+	return 0;
+}
+
+static inline void __mod_memcg_state(struct mem_cgroup *memcg,
+				     int idx,
+				     int nr)
+{
+}
+
+static inline void mod_memcg_state(struct mem_cgroup *memcg,
+				   int idx,
+				   int nr)
+{
+}
+
+static inline void __mod_memcg_page_state(struct page *page,
+					  int idx,
+					  int nr)
+{
+}
+
+static inline void mod_memcg_page_state(struct page *page,
+					int idx,
+					int nr)
+{
+}
+
+static inline unsigned long lruvec_page_state(struct lruvec *lruvec,
+					      enum node_stat_item idx)
+{
+	return node_page_state(lruvec_pgdat(lruvec), idx);
+}
+
+static inline void __mod_lruvec_state(struct lruvec *lruvec,
+				      enum node_stat_item idx, int val)
+{
+	__mod_node_page_state(lruvec_pgdat(lruvec), idx, val);
+}
+
+static inline void mod_lruvec_state(struct lruvec *lruvec,
+				    enum node_stat_item idx, int val)
+{
+	mod_node_page_state(lruvec_pgdat(lruvec), idx, val);
+}
+
+static inline void __mod_lruvec_page_state(struct page *page,
+					   enum node_stat_item idx, int val)
+{
+	__mod_node_page_state(page_pgdat(page), idx, val);
+}
+
+static inline void mod_lruvec_page_state(struct page *page,
+					 enum node_stat_item idx, int val)
+{
+	mod_node_page_state(page_pgdat(page), idx, val);
+}
+
+static inline
+unsigned long mem_cgroup_soft_limit_reclaim(pg_data_t *pgdat, int order,
+					    gfp_t gfp_mask,
+					    unsigned long *total_scanned)
+{
+	return 0;
+}
+
+static inline void mem_cgroup_split_huge_fixup(struct page *head)
+{
+}
+
+static inline void count_memcg_events(struct mem_cgroup *memcg,
+				      enum vm_event_item idx,
+				      unsigned long count)
+{
+}
+
+static inline void count_memcg_page_event(struct page *page,
+					  int idx)
+{
+}
+
+static inline
+void count_memcg_event_mm(struct mm_struct *mm, enum vm_event_item idx)
+{
+}
+#endif /* CONFIG_MEMCG */
+
+/* idx can be of type enum memcg_stat_item or node_stat_item */
+static inline void __inc_memcg_state(struct mem_cgroup *memcg,
+				     int idx)
+{
+	__mod_memcg_state(memcg, idx, 1);
+}
+
+/* idx can be of type enum memcg_stat_item or node_stat_item */
+static inline void __dec_memcg_state(struct mem_cgroup *memcg,
+				     int idx)
+{
+	__mod_memcg_state(memcg, idx, -1);
+}
+
+/* idx can be of type enum memcg_stat_item or node_stat_item */
+static inline void __inc_memcg_page_state(struct page *page,
+					  int idx)
+{
+	__mod_memcg_page_state(page, idx, 1);
+}
+
+/* idx can be of type enum memcg_stat_item or node_stat_item */
+static inline void __dec_memcg_page_state(struct page *page,
+					  int idx)
+{
+	__mod_memcg_page_state(page, idx, -1);
+}
+
+static inline void __inc_lruvec_state(struct lruvec *lruvec,
+				      enum node_stat_item idx)
+{
+	__mod_lruvec_state(lruvec, idx, 1);
+}
+
+static inline void __dec_lruvec_state(struct lruvec *lruvec,
+				      enum node_stat_item idx)
+{
+	__mod_lruvec_state(lruvec, idx, -1);
+}
+
+static inline void __inc_lruvec_page_state(struct page *page,
+					   enum node_stat_item idx)
+{
+	__mod_lruvec_page_state(page, idx, 1);
+}
+
+static inline void __dec_lruvec_page_state(struct page *page,
+					   enum node_stat_item idx)
+{
+	__mod_lruvec_page_state(page, idx, -1);
+}
+
+/* idx can be of type enum memcg_stat_item or node_stat_item */
+static inline void inc_memcg_state(struct mem_cgroup *memcg,
+				   int idx)
+{
+	mod_memcg_state(memcg, idx, 1);
+}
+
+/* idx can be of type enum memcg_stat_item or node_stat_item */
+static inline void dec_memcg_state(struct mem_cgroup *memcg,
+				   int idx)
+{
+	mod_memcg_state(memcg, idx, -1);
+}
+
+/* idx can be of type enum memcg_stat_item or node_stat_item */
+static inline void inc_memcg_page_state(struct page *page,
+					int idx)
+{
+	mod_memcg_page_state(page, idx, 1);
+}
+
+/* idx can be of type enum memcg_stat_item or node_stat_item */
+static inline void dec_memcg_page_state(struct page *page,
+					int idx)
+{
+	mod_memcg_page_state(page, idx, -1);
+}
+
+static inline void inc_lruvec_state(struct lruvec *lruvec,
+				    enum node_stat_item idx)
+{
+	mod_lruvec_state(lruvec, idx, 1);
+}
+
+static inline void dec_lruvec_state(struct lruvec *lruvec,
+				    enum node_stat_item idx)
+{
+	mod_lruvec_state(lruvec, idx, -1);
+}
+
+static inline void inc_lruvec_page_state(struct page *page,
+					 enum node_stat_item idx)
+{
+	mod_lruvec_page_state(page, idx, 1);
+}
+
+static inline void dec_lruvec_page_state(struct page *page,
+					 enum node_stat_item idx)
+{
+	mod_lruvec_page_state(page, idx, -1);
+}
+
+#ifdef CONFIG_CGROUP_WRITEBACK
+
+struct wb_domain *mem_cgroup_wb_domain(struct bdi_writeback *wb);
+void mem_cgroup_wb_stats(struct bdi_writeback *wb, unsigned long *pfilepages,
+			 unsigned long *pheadroom, unsigned long *pdirty,
+			 unsigned long *pwriteback);
+
+#else	/* CONFIG_CGROUP_WRITEBACK */
+
+static inline struct wb_domain *mem_cgroup_wb_domain(struct bdi_writeback *wb)
+{
+	return NULL;
+}
+
+static inline void mem_cgroup_wb_stats(struct bdi_writeback *wb,
+				       unsigned long *pfilepages,
+				       unsigned long *pheadroom,
+				       unsigned long *pdirty,
+				       unsigned long *pwriteback)
+{
+}
+
+#endif	/* CONFIG_CGROUP_WRITEBACK */
+
+struct sock;
+bool mem_cgroup_charge_skmem(struct mem_cgroup *memcg, unsigned int nr_pages);
+void mem_cgroup_uncharge_skmem(struct mem_cgroup *memcg, unsigned int nr_pages);
+#ifdef CONFIG_MEMCG
+extern struct static_key_false memcg_sockets_enabled_key;
+#define mem_cgroup_sockets_enabled static_branch_unlikely(&memcg_sockets_enabled_key)
+void mem_cgroup_sk_alloc(struct sock *sk);
+void mem_cgroup_sk_free(struct sock *sk);
+static inline bool mem_cgroup_under_socket_pressure(struct mem_cgroup *memcg)
+{
+	if (!cgroup_subsys_on_dfl(memory_cgrp_subsys) && memcg->tcpmem_pressure)
+		return true;
+	do {
+		if (time_before(jiffies, memcg->socket_pressure))
+			return true;
+	} while ((memcg = parent_mem_cgroup(memcg)));
+	return false;
+}
+#else
+#define mem_cgroup_sockets_enabled 0
+static inline void mem_cgroup_sk_alloc(struct sock *sk) { };
+static inline void mem_cgroup_sk_free(struct sock *sk) { };
+static inline bool mem_cgroup_under_socket_pressure(struct mem_cgroup *memcg)
+{
+	return false;
+}
+#endif
+
+struct kmem_cache *memcg_kmem_get_cache(struct kmem_cache *cachep);
+void memcg_kmem_put_cache(struct kmem_cache *cachep);
+int memcg_kmem_charge_memcg(struct page *page, gfp_t gfp, int order,
+			    struct mem_cgroup *memcg);
+int memcg_kmem_charge(struct page *page, gfp_t gfp, int order);
+void memcg_kmem_uncharge(struct page *page, int order);
+
+#ifdef CONFIG_MEMCG_KMEM
+extern struct static_key_false memcg_kmem_enabled_key;
+extern struct workqueue_struct *memcg_kmem_cache_wq;
+
+extern int memcg_nr_cache_ids;
+void memcg_get_cache_ids(void);
+void memcg_put_cache_ids(void);
+
+/*
+ * Helper macro to loop through all memcg-specific caches. Callers must still
+ * check if the cache is valid (it is either valid or NULL).
+ * the slab_mutex must be held when looping through those caches
+ */
+#define for_each_memcg_cache_index(_idx)	\
+	for ((_idx) = 0; (_idx) < memcg_nr_cache_ids; (_idx)++)
+
+static inline bool memcg_kmem_enabled(void)
+{
+	return static_branch_unlikely(&memcg_kmem_enabled_key);
+}
+
+/*
+ * helper for accessing a memcg's index. It will be used as an index in the
+ * child cache array in kmem_cache, and also to derive its name. This function
+ * will return -1 when this is not a kmem-limited memcg.
+ */
+static inline int memcg_cache_id(struct mem_cgroup *memcg)
+{
+	return memcg ? memcg->kmemcg_id : -1;
+}
+
+extern int memcg_expand_shrinker_maps(int new_id);
+
+extern void memcg_set_shrinker_bit(struct mem_cgroup *memcg,
+				   int nid, int shrinker_id);
+#else
+#define for_each_memcg_cache_index(_idx)	\
+	for (; NULL; )
+
+static inline bool memcg_kmem_enabled(void)
+{
+	return false;
+}
+
+static inline int memcg_cache_id(struct mem_cgroup *memcg)
+{
+	return -1;
+}
+
+static inline void memcg_get_cache_ids(void)
+{
+}
+
+static inline void memcg_put_cache_ids(void)
+{
+}
+
+static inline void memcg_set_shrinker_bit(struct mem_cgroup *memcg,
+					  int nid, int shrinker_id) { }
+#endif /* CONFIG_MEMCG_KMEM */
+
+#endif /* _LINUX_MEMCONTROL_H */