[mirror_ubuntu-bionic-kernel.git] / mm / list_lru.c

/*
 * Copyright (c) 2013 Red Hat, Inc. and Parallels Inc. All rights reserved.
 * Authors: David Chinner and Glauber Costa
 *
 * Generic LRU infrastructure
 */
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/mm.h>
#include <linux/list_lru.h>
#include <linux/slab.h>
#include <linux/mutex.h>
#include <linux/memcontrol.h>

#ifdef CONFIG_MEMCG_KMEM
static LIST_HEAD(list_lrus);
static DEFINE_MUTEX(list_lrus_mutex);

static void list_lru_register(struct list_lru *lru)
{
	mutex_lock(&list_lrus_mutex);
	list_add(&lru->list, &list_lrus);
	mutex_unlock(&list_lrus_mutex);
}

static void list_lru_unregister(struct list_lru *lru)
{
	mutex_lock(&list_lrus_mutex);
	list_del(&lru->list);
	mutex_unlock(&list_lrus_mutex);
}
#else
static void list_lru_register(struct list_lru *lru)
{
}

static void list_lru_unregister(struct list_lru *lru)
{
}
#endif /* CONFIG_MEMCG_KMEM */

#ifdef CONFIG_MEMCG_KMEM
static inline bool list_lru_memcg_aware(struct list_lru *lru)
{
	return !!lru->node[0].memcg_lrus;
}

static inline struct list_lru_one *
list_lru_from_memcg_idx(struct list_lru_node *nlru, int idx)
{
	/*
	 * The lock protects the array of per cgroup lists from relocation
	 * (see memcg_update_list_lru_node).
	 */
	lockdep_assert_held(&nlru->lock);
	if (nlru->memcg_lrus && idx >= 0)
		return nlru->memcg_lrus->lru[idx];

	return &nlru->lru;
}

static inline struct list_lru_one *
list_lru_from_kmem(struct list_lru_node *nlru, void *ptr)
{
	struct mem_cgroup *memcg;

	if (!nlru->memcg_lrus)
		return &nlru->lru;

	memcg = mem_cgroup_from_kmem(ptr);
	if (!memcg)
		return &nlru->lru;

	return list_lru_from_memcg_idx(nlru, memcg_cache_id(memcg));
}
#else
static inline bool list_lru_memcg_aware(struct list_lru *lru)
{
	return false;
}

static inline struct list_lru_one *
list_lru_from_memcg_idx(struct list_lru_node *nlru, int idx)
{
	return &nlru->lru;
}

static inline struct list_lru_one *
list_lru_from_kmem(struct list_lru_node *nlru, void *ptr)
{
	return &nlru->lru;
}
#endif /* CONFIG_MEMCG_KMEM */

bool list_lru_add(struct list_lru *lru, struct list_head *item)
{
	int nid = page_to_nid(virt_to_page(item));
	struct list_lru_node *nlru = &lru->node[nid];
	struct list_lru_one *l;

	spin_lock(&nlru->lock);
	l = list_lru_from_kmem(nlru, item);
	WARN_ON_ONCE(l->nr_items < 0);
	if (list_empty(item)) {
		list_add_tail(item, &l->list);
		l->nr_items++;
		spin_unlock(&nlru->lock);
		return true;
	}
	spin_unlock(&nlru->lock);
	return false;
}
EXPORT_SYMBOL_GPL(list_lru_add);

bool list_lru_del(struct list_lru *lru, struct list_head *item)
{
	int nid = page_to_nid(virt_to_page(item));
	struct list_lru_node *nlru = &lru->node[nid];
	struct list_lru_one *l;

	spin_lock(&nlru->lock);
	l = list_lru_from_kmem(nlru, item);
	if (!list_empty(item)) {
		list_del_init(item);
		l->nr_items--;
		WARN_ON_ONCE(l->nr_items < 0);
		spin_unlock(&nlru->lock);
		return true;
	}
	spin_unlock(&nlru->lock);
	return false;
}
EXPORT_SYMBOL_GPL(list_lru_del);

void list_lru_isolate(struct list_lru_one *list, struct list_head *item)
{
	list_del_init(item);
	list->nr_items--;
}
EXPORT_SYMBOL_GPL(list_lru_isolate);

void list_lru_isolate_move(struct list_lru_one *list, struct list_head *item,
			   struct list_head *head)
{
	list_move(item, head);
	list->nr_items--;
}
EXPORT_SYMBOL_GPL(list_lru_isolate_move);

static unsigned long __list_lru_count_one(struct list_lru *lru,
					  int nid, int memcg_idx)
{
	struct list_lru_node *nlru = &lru->node[nid];
	struct list_lru_one *l;
	unsigned long count;

	spin_lock(&nlru->lock);
	l = list_lru_from_memcg_idx(nlru, memcg_idx);
	WARN_ON_ONCE(l->nr_items < 0);
	count = l->nr_items;
	spin_unlock(&nlru->lock);

	return count;
}

unsigned long list_lru_count_one(struct list_lru *lru,
				 int nid, struct mem_cgroup *memcg)
{
	return __list_lru_count_one(lru, nid, memcg_cache_id(memcg));
}
EXPORT_SYMBOL_GPL(list_lru_count_one);

unsigned long list_lru_count_node(struct list_lru *lru, int nid)
{
	long count = 0;
	int memcg_idx;

	count += __list_lru_count_one(lru, nid, -1);
	if (list_lru_memcg_aware(lru)) {
		for_each_memcg_cache_index(memcg_idx)
			count += __list_lru_count_one(lru, nid, memcg_idx);
	}
	return count;
}
EXPORT_SYMBOL_GPL(list_lru_count_node);

static unsigned long
__list_lru_walk_one(struct list_lru *lru, int nid, int memcg_idx,
		    list_lru_walk_cb isolate, void *cb_arg,
		    unsigned long *nr_to_walk)
{

	struct list_lru_node *nlru = &lru->node[nid];
	struct list_lru_one *l;
	struct list_head *item, *n;
	unsigned long isolated = 0;

	spin_lock(&nlru->lock);
	l = list_lru_from_memcg_idx(nlru, memcg_idx);
restart:
	list_for_each_safe(item, n, &l->list) {
		enum lru_status ret;

		/*
		 * decrement nr_to_walk first so that we don't livelock if we
		 * get stuck on large numbesr of LRU_RETRY items
		 */
		if (!*nr_to_walk)
			break;
		--*nr_to_walk;

		ret = isolate(item, l, &nlru->lock, cb_arg);
		switch (ret) {
		case LRU_REMOVED_RETRY:
			assert_spin_locked(&nlru->lock);
		case LRU_REMOVED:
			isolated++;
			/*
			 * If the lru lock has been dropped, our list
			 * traversal is now invalid and so we have to
			 * restart from scratch.
			 */
			if (ret == LRU_REMOVED_RETRY)
				goto restart;
			break;
		case LRU_ROTATE:
			list_move_tail(item, &l->list);
			break;
		case LRU_SKIP:
			break;
		case LRU_RETRY:
			/*
			 * The lru lock has been dropped, our list traversal is
			 * now invalid and so we have to restart from scratch.
			 */
			assert_spin_locked(&nlru->lock);
			goto restart;
		default:
			BUG();
		}
	}

	spin_unlock(&nlru->lock);
	return isolated;
}

unsigned long
list_lru_walk_one(struct list_lru *lru, int nid, struct mem_cgroup *memcg,
		  list_lru_walk_cb isolate, void *cb_arg,
		  unsigned long *nr_to_walk)
{
	return __list_lru_walk_one(lru, nid, memcg_cache_id(memcg),
				   isolate, cb_arg, nr_to_walk);
}
EXPORT_SYMBOL_GPL(list_lru_walk_one);

unsigned long list_lru_walk_node(struct list_lru *lru, int nid,
				 list_lru_walk_cb isolate, void *cb_arg,
				 unsigned long *nr_to_walk)
{
	long isolated = 0;
	int memcg_idx;

	isolated += __list_lru_walk_one(lru, nid, -1, isolate, cb_arg,
					nr_to_walk);
	if (*nr_to_walk > 0 && list_lru_memcg_aware(lru)) {
		for_each_memcg_cache_index(memcg_idx) {
			isolated += __list_lru_walk_one(lru, nid, memcg_idx,
						isolate, cb_arg, nr_to_walk);
			if (*nr_to_walk <= 0)
				break;
		}
	}
	return isolated;
}
EXPORT_SYMBOL_GPL(list_lru_walk_node);

static void init_one_lru(struct list_lru_one *l)
{
	INIT_LIST_HEAD(&l->list);
	l->nr_items = 0;
}

#ifdef CONFIG_MEMCG_KMEM
static void __memcg_destroy_list_lru_node(struct list_lru_memcg *memcg_lrus,
					  int begin, int end)
{
	int i;

	for (i = begin; i < end; i++)
		kfree(memcg_lrus->lru[i]);
}

static int __memcg_init_list_lru_node(struct list_lru_memcg *memcg_lrus,
				      int begin, int end)
{
	int i;

	for (i = begin; i < end; i++) {
		struct list_lru_one *l;

		l = kmalloc(sizeof(struct list_lru_one), GFP_KERNEL);
		if (!l)
			goto fail;

		init_one_lru(l);
		memcg_lrus->lru[i] = l;
	}
	return 0;
fail:
	__memcg_destroy_list_lru_node(memcg_lrus, begin, i - 1);
	return -ENOMEM;
}

static int memcg_init_list_lru_node(struct list_lru_node *nlru)
{
	int size = memcg_nr_cache_ids;

	nlru->memcg_lrus = kmalloc(size * sizeof(void *), GFP_KERNEL);
	if (!nlru->memcg_lrus)
		return -ENOMEM;

	if (__memcg_init_list_lru_node(nlru->memcg_lrus, 0, size)) {
		kfree(nlru->memcg_lrus);
		return -ENOMEM;
	}

	return 0;
}

static void memcg_destroy_list_lru_node(struct list_lru_node *nlru)
{
	__memcg_destroy_list_lru_node(nlru->memcg_lrus, 0, memcg_nr_cache_ids);
	kfree(nlru->memcg_lrus);
}

static int memcg_update_list_lru_node(struct list_lru_node *nlru,
				      int old_size, int new_size)
{
	struct list_lru_memcg *old, *new;

	BUG_ON(old_size > new_size);

	old = nlru->memcg_lrus;
	new = kmalloc(new_size * sizeof(void *), GFP_KERNEL);
	if (!new)
		return -ENOMEM;

	if (__memcg_init_list_lru_node(new, old_size, new_size)) {
		kfree(new);
		return -ENOMEM;
	}

	memcpy(new, old, old_size * sizeof(void *));

	/*
	 * The lock guarantees that we won't race with a reader
	 * (see list_lru_from_memcg_idx).
	 *
	 * Since list_lru_{add,del} may be called under an IRQ-safe lock,
	 * we have to use IRQ-safe primitives here to avoid deadlock.
	 */
	spin_lock_irq(&nlru->lock);
	nlru->memcg_lrus = new;
	spin_unlock_irq(&nlru->lock);

	kfree(old);
	return 0;
}

static void memcg_cancel_update_list_lru_node(struct list_lru_node *nlru,
					      int old_size, int new_size)
{
	/* do not bother shrinking the array back to the old size, because we
	 * cannot handle allocation failures here */
	__memcg_destroy_list_lru_node(nlru->memcg_lrus, old_size, new_size);
}

static int memcg_init_list_lru(struct list_lru *lru, bool memcg_aware)
{
	int i;

	for (i = 0; i < nr_node_ids; i++) {
		if (!memcg_aware)
			lru->node[i].memcg_lrus = NULL;
		else if (memcg_init_list_lru_node(&lru->node[i]))
			goto fail;
	}
	return 0;
fail:
	for (i = i - 1; i >= 0; i--)
		memcg_destroy_list_lru_node(&lru->node[i]);
	return -ENOMEM;
}

static void memcg_destroy_list_lru(struct list_lru *lru)
{
	int i;

	if (!list_lru_memcg_aware(lru))
		return;

	for (i = 0; i < nr_node_ids; i++)
		memcg_destroy_list_lru_node(&lru->node[i]);
}

static int memcg_update_list_lru(struct list_lru *lru,
				 int old_size, int new_size)
{
	int i;

	if (!list_lru_memcg_aware(lru))
		return 0;

	for (i = 0; i < nr_node_ids; i++) {
		if (memcg_update_list_lru_node(&lru->node[i],
					       old_size, new_size))
			goto fail;
	}
	return 0;
fail:
	for (i = i - 1; i >= 0; i--)
		memcg_cancel_update_list_lru_node(&lru->node[i],
						  old_size, new_size);
	return -ENOMEM;
}

static void memcg_cancel_update_list_lru(struct list_lru *lru,
					 int old_size, int new_size)
{
	int i;

	if (!list_lru_memcg_aware(lru))
		return;

	for (i = 0; i < nr_node_ids; i++)
		memcg_cancel_update_list_lru_node(&lru->node[i],
						  old_size, new_size);
}

int memcg_update_all_list_lrus(int new_size)
{
	int ret = 0;
	struct list_lru *lru;
	int old_size = memcg_nr_cache_ids;

	mutex_lock(&list_lrus_mutex);
	list_for_each_entry(lru, &list_lrus, list) {
		ret = memcg_update_list_lru(lru, old_size, new_size);
		if (ret)
			goto fail;
	}
out:
	mutex_unlock(&list_lrus_mutex);
	return ret;
fail:
	list_for_each_entry_continue_reverse(lru, &list_lrus, list)
		memcg_cancel_update_list_lru(lru, old_size, new_size);
	goto out;
}
#else
static int memcg_init_list_lru(struct list_lru *lru, bool memcg_aware)
{
	return 0;
}

static void memcg_destroy_list_lru(struct list_lru *lru)
{
}
#endif /* CONFIG_MEMCG_KMEM */

int __list_lru_init(struct list_lru *lru, bool memcg_aware,
		    struct lock_class_key *key)
{
	int i;
	size_t size = sizeof(*lru->node) * nr_node_ids;
	int err = -ENOMEM;

	memcg_get_cache_ids();

	lru->node = kzalloc(size, GFP_KERNEL);
	if (!lru->node)
		goto out;

	for (i = 0; i < nr_node_ids; i++) {
		spin_lock_init(&lru->node[i].lock);
		if (key)
			lockdep_set_class(&lru->node[i].lock, key);
		init_one_lru(&lru->node[i].lru);
	}

	err = memcg_init_list_lru(lru, memcg_aware);
	if (err) {
		kfree(lru->node);
		goto out;
	}

	list_lru_register(lru);
out:
	memcg_put_cache_ids();
	return err;
}
EXPORT_SYMBOL_GPL(__list_lru_init);

void list_lru_destroy(struct list_lru *lru)
{
	/* Already destroyed or not yet initialized? */
	if (!lru->node)
		return;

	memcg_get_cache_ids();

	list_lru_unregister(lru);

	memcg_destroy_list_lru(lru);
	kfree(lru->node);
	lru->node = NULL;

	memcg_put_cache_ids();
}
EXPORT_SYMBOL_GPL(list_lru_destroy);
Commit	Line	Data
a38e4082 DC	1	/*
	2	* Copyright (c) 2013 Red Hat, Inc. and Parallels Inc. All rights reserved.
	3	* Authors: David Chinner and Glauber Costa
	4	*
	5	* Generic LRU infrastructure
	6	*/
	7	#include <linux/kernel.h>
	8	#include <linux/module.h>
3b1d58a4	9	#include <linux/mm.h>
a38e4082	10	#include <linux/list_lru.h>
5ca302c8	11	#include <linux/slab.h>
c0a5b560	12	#include <linux/mutex.h>
60d3fd32	13	#include <linux/memcontrol.h>
c0a5b560 VD	14
	15	#ifdef CONFIG_MEMCG_KMEM
	16	static LIST_HEAD(list_lrus);
	17	static DEFINE_MUTEX(list_lrus_mutex);
	18
	19	static void list_lru_register(struct list_lru *lru)
	20	{
	21	mutex_lock(&list_lrus_mutex);
	22	list_add(&lru->list, &list_lrus);
	23	mutex_unlock(&list_lrus_mutex);
	24	}
	25
	26	static void list_lru_unregister(struct list_lru *lru)
	27	{
	28	mutex_lock(&list_lrus_mutex);
	29	list_del(&lru->list);
	30	mutex_unlock(&list_lrus_mutex);
	31	}
	32	#else
	33	static void list_lru_register(struct list_lru *lru)
	34	{
	35	}
	36
	37	static void list_lru_unregister(struct list_lru *lru)
	38	{
	39	}
	40	#endif /* CONFIG_MEMCG_KMEM */
a38e4082	41
60d3fd32 VD	42	#ifdef CONFIG_MEMCG_KMEM
	43	static inline bool list_lru_memcg_aware(struct list_lru *lru)
	44	{
	45	return !!lru->node[0].memcg_lrus;
	46	}
	47
	48	static inline struct list_lru_one *
	49	list_lru_from_memcg_idx(struct list_lru_node *nlru, int idx)
	50	{
	51	/*
	52	* The lock protects the array of per cgroup lists from relocation
	53	* (see memcg_update_list_lru_node).
	54	*/
	55	lockdep_assert_held(&nlru->lock);
	56	if (nlru->memcg_lrus && idx >= 0)
	57	return nlru->memcg_lrus->lru[idx];
	58
	59	return &nlru->lru;
	60	}
	61
	62	static inline struct list_lru_one *
	63	list_lru_from_kmem(struct list_lru_node nlru, void ptr)
	64	{
	65	struct mem_cgroup *memcg;
	66
	67	if (!nlru->memcg_lrus)
	68	return &nlru->lru;
	69
	70	memcg = mem_cgroup_from_kmem(ptr);
	71	if (!memcg)
	72	return &nlru->lru;
	73
	74	return list_lru_from_memcg_idx(nlru, memcg_cache_id(memcg));
	75	}
	76	#else
	77	static inline bool list_lru_memcg_aware(struct list_lru *lru)
	78	{
	79	return false;
	80	}
	81
	82	static inline struct list_lru_one *
	83	list_lru_from_memcg_idx(struct list_lru_node *nlru, int idx)
	84	{
	85	return &nlru->lru;
	86	}
	87
	88	static inline struct list_lru_one *
	89	list_lru_from_kmem(struct list_lru_node nlru, void ptr)
	90	{
	91	return &nlru->lru;
	92	}
	93	#endif /* CONFIG_MEMCG_KMEM */
	94
a38e4082 DC	95	bool list_lru_add(struct list_lru lru, struct list_head item)
a38e4082 DC	96	{
3b1d58a4 DC	97	int nid = page_to_nid(virt_to_page(item));
3b1d58a4 DC	98	struct list_lru_node *nlru = &lru->node[nid];
60d3fd32	99	struct list_lru_one *l;
3b1d58a4 DC	100
3b1d58a4 DC	101	spin_lock(&nlru->lock);
60d3fd32 VD	102	l = list_lru_from_kmem(nlru, item);
60d3fd32 VD	103	WARN_ON_ONCE(l->nr_items < 0);
a38e4082	104	if (list_empty(item)) {
60d3fd32 VD	105	list_add_tail(item, &l->list);
60d3fd32 VD	106	l->nr_items++;
3b1d58a4	107	spin_unlock(&nlru->lock);
a38e4082 DC	108	return true;
a38e4082 DC	109	}
3b1d58a4	110	spin_unlock(&nlru->lock);
a38e4082 DC	111	return false;
	112	}
	113	EXPORT_SYMBOL_GPL(list_lru_add);
	114
	115	bool list_lru_del(struct list_lru lru, struct list_head item)
	116	{
3b1d58a4 DC	117	int nid = page_to_nid(virt_to_page(item));
3b1d58a4 DC	118	struct list_lru_node *nlru = &lru->node[nid];
60d3fd32	119	struct list_lru_one *l;
3b1d58a4 DC	120
3b1d58a4 DC	121	spin_lock(&nlru->lock);
60d3fd32	122	l = list_lru_from_kmem(nlru, item);
a38e4082 DC	123	if (!list_empty(item)) {
a38e4082 DC	124	list_del_init(item);
60d3fd32 VD	125	l->nr_items--;
60d3fd32 VD	126	WARN_ON_ONCE(l->nr_items < 0);
3b1d58a4	127	spin_unlock(&nlru->lock);
a38e4082 DC	128	return true;
a38e4082 DC	129	}
3b1d58a4	130	spin_unlock(&nlru->lock);
a38e4082 DC	131	return false;
	132	}
	133	EXPORT_SYMBOL_GPL(list_lru_del);
	134
3f97b163 VD	135	void list_lru_isolate(struct list_lru_one list, struct list_head item)
	136	{
	137	list_del_init(item);
	138	list->nr_items--;
	139	}
	140	EXPORT_SYMBOL_GPL(list_lru_isolate);
	141
	142	void list_lru_isolate_move(struct list_lru_one list, struct list_head item,
	143	struct list_head *head)
	144	{
	145	list_move(item, head);
	146	list->nr_items--;
	147	}
	148	EXPORT_SYMBOL_GPL(list_lru_isolate_move);
	149
60d3fd32 VD	150	static unsigned long __list_lru_count_one(struct list_lru *lru,
60d3fd32 VD	151	int nid, int memcg_idx)
a38e4082	152	{
6a4f496f	153	struct list_lru_node *nlru = &lru->node[nid];
60d3fd32 VD	154	struct list_lru_one *l;
60d3fd32 VD	155	unsigned long count;
3b1d58a4	156
6a4f496f	157	spin_lock(&nlru->lock);
60d3fd32 VD	158	l = list_lru_from_memcg_idx(nlru, memcg_idx);
	159	WARN_ON_ONCE(l->nr_items < 0);
	160	count = l->nr_items;
6a4f496f	161	spin_unlock(&nlru->lock);
3b1d58a4 DC	162
	163	return count;
	164	}
60d3fd32 VD	165
	166	unsigned long list_lru_count_one(struct list_lru *lru,
	167	int nid, struct mem_cgroup *memcg)
	168	{
	169	return __list_lru_count_one(lru, nid, memcg_cache_id(memcg));
	170	}
	171	EXPORT_SYMBOL_GPL(list_lru_count_one);
	172
	173	unsigned long list_lru_count_node(struct list_lru *lru, int nid)
	174	{
	175	long count = 0;
	176	int memcg_idx;
	177
	178	count += __list_lru_count_one(lru, nid, -1);
	179	if (list_lru_memcg_aware(lru)) {
	180	for_each_memcg_cache_index(memcg_idx)
	181	count += __list_lru_count_one(lru, nid, memcg_idx);
	182	}
	183	return count;
	184	}
6a4f496f	185	EXPORT_SYMBOL_GPL(list_lru_count_node);
3b1d58a4	186
60d3fd32 VD	187	static unsigned long
	188	__list_lru_walk_one(struct list_lru *lru, int nid, int memcg_idx,
	189	list_lru_walk_cb isolate, void *cb_arg,
	190	unsigned long *nr_to_walk)
3b1d58a4 DC	191	{
3b1d58a4 DC	192
60d3fd32 VD	193	struct list_lru_node *nlru = &lru->node[nid];
60d3fd32 VD	194	struct list_lru_one *l;
a38e4082	195	struct list_head item, n;
3b1d58a4	196	unsigned long isolated = 0;
a38e4082	197
3b1d58a4	198	spin_lock(&nlru->lock);
60d3fd32	199	l = list_lru_from_memcg_idx(nlru, memcg_idx);
a38e4082	200	restart:
60d3fd32	201	list_for_each_safe(item, n, &l->list) {
a38e4082	202	enum lru_status ret;
5cedf721 DC	203
	204	/*
	205	* decrement nr_to_walk first so that we don't livelock if we
	206	* get stuck on large numbesr of LRU_RETRY items
	207	*/
c56b097a	208	if (!*nr_to_walk)
5cedf721	209	break;
c56b097a	210	--*nr_to_walk;
5cedf721	211
3f97b163	212	ret = isolate(item, l, &nlru->lock, cb_arg);
a38e4082	213	switch (ret) {
449dd698 JW	214	case LRU_REMOVED_RETRY:
449dd698 JW	215	assert_spin_locked(&nlru->lock);
a38e4082	216	case LRU_REMOVED:
3b1d58a4	217	isolated++;
449dd698 JW	218	/*
	219	* If the lru lock has been dropped, our list
	220	* traversal is now invalid and so we have to
	221	* restart from scratch.
	222	*/
	223	if (ret == LRU_REMOVED_RETRY)
	224	goto restart;
a38e4082 DC	225	break;
a38e4082 DC	226	case LRU_ROTATE:
60d3fd32	227	list_move_tail(item, &l->list);
a38e4082 DC	228	break;
	229	case LRU_SKIP:
	230	break;
	231	case LRU_RETRY:
5cedf721 DC	232	/*
	233	* The lru lock has been dropped, our list traversal is
	234	* now invalid and so we have to restart from scratch.
	235	*/
449dd698	236	assert_spin_locked(&nlru->lock);
a38e4082 DC	237	goto restart;
	238	default:
	239	BUG();
	240	}
a38e4082	241	}
3b1d58a4 DC	242
	243	spin_unlock(&nlru->lock);
	244	return isolated;
	245	}
60d3fd32 VD	246
	247	unsigned long
	248	list_lru_walk_one(struct list_lru lru, int nid, struct mem_cgroup memcg,
	249	list_lru_walk_cb isolate, void *cb_arg,
	250	unsigned long *nr_to_walk)
	251	{
	252	return __list_lru_walk_one(lru, nid, memcg_cache_id(memcg),
	253	isolate, cb_arg, nr_to_walk);
	254	}
	255	EXPORT_SYMBOL_GPL(list_lru_walk_one);
	256
	257	unsigned long list_lru_walk_node(struct list_lru *lru, int nid,
	258	list_lru_walk_cb isolate, void *cb_arg,
	259	unsigned long *nr_to_walk)
	260	{
	261	long isolated = 0;
	262	int memcg_idx;
	263
	264	isolated += __list_lru_walk_one(lru, nid, -1, isolate, cb_arg,
	265	nr_to_walk);
	266	if (*nr_to_walk > 0 && list_lru_memcg_aware(lru)) {
	267	for_each_memcg_cache_index(memcg_idx) {
	268	isolated += __list_lru_walk_one(lru, nid, memcg_idx,
	269	isolate, cb_arg, nr_to_walk);
	270	if (*nr_to_walk <= 0)
	271	break;
	272	}
	273	}
	274	return isolated;
	275	}
3b1d58a4 DC	276	EXPORT_SYMBOL_GPL(list_lru_walk_node);
3b1d58a4 DC	277
60d3fd32 VD	278	static void init_one_lru(struct list_lru_one *l)
	279	{
	280	INIT_LIST_HEAD(&l->list);
	281	l->nr_items = 0;
	282	}
	283
	284	#ifdef CONFIG_MEMCG_KMEM
	285	static void __memcg_destroy_list_lru_node(struct list_lru_memcg *memcg_lrus,
	286	int begin, int end)
	287	{
	288	int i;
	289
	290	for (i = begin; i < end; i++)
	291	kfree(memcg_lrus->lru[i]);
	292	}
	293
	294	static int __memcg_init_list_lru_node(struct list_lru_memcg *memcg_lrus,
	295	int begin, int end)
	296	{
	297	int i;
	298
	299	for (i = begin; i < end; i++) {
	300	struct list_lru_one *l;
	301
	302	l = kmalloc(sizeof(struct list_lru_one), GFP_KERNEL);
	303	if (!l)
	304	goto fail;
	305
	306	init_one_lru(l);
	307	memcg_lrus->lru[i] = l;
	308	}
	309	return 0;
	310	fail:
	311	__memcg_destroy_list_lru_node(memcg_lrus, begin, i - 1);
	312	return -ENOMEM;
	313	}
	314
	315	static int memcg_init_list_lru_node(struct list_lru_node *nlru)
	316	{
	317	int size = memcg_nr_cache_ids;
	318
	319	nlru->memcg_lrus = kmalloc(size * sizeof(void *), GFP_KERNEL);
	320	if (!nlru->memcg_lrus)
	321	return -ENOMEM;
	322
	323	if (__memcg_init_list_lru_node(nlru->memcg_lrus, 0, size)) {
	324	kfree(nlru->memcg_lrus);
	325	return -ENOMEM;
	326	}
	327
	328	return 0;
	329	}
	330
	331	static void memcg_destroy_list_lru_node(struct list_lru_node *nlru)
	332	{
	333	__memcg_destroy_list_lru_node(nlru->memcg_lrus, 0, memcg_nr_cache_ids);
	334	kfree(nlru->memcg_lrus);
	335	}
	336
	337	static int memcg_update_list_lru_node(struct list_lru_node *nlru,
	338	int old_size, int new_size)
	339	{
	340	struct list_lru_memcg old, new;
	341
342	BUG_ON(old_size > new_size);
343
344	old = nlru->memcg_lrus;
345	new = kmalloc(new_size * sizeof(void *), GFP_KERNEL);
346	if (!new)
347	return -ENOMEM;
348
349	if (__memcg_init_list_lru_node(new, old_size, new_size)) {
350	kfree(new);
351	return -ENOMEM;
352	}
353
354	memcpy(new, old, old_size * sizeof(void *));
355
356	/*
357	* The lock guarantees that we won't race with a reader
358	* (see list_lru_from_memcg_idx).
359	*
360	* Since list_lru_{add,del} may be called under an IRQ-safe lock,
361	* we have to use IRQ-safe primitives here to avoid deadlock.
362	*/
363	spin_lock_irq(&nlru->lock);
364	nlru->memcg_lrus = new;
365	spin_unlock_irq(&nlru->lock);
366
367	kfree(old);
368	return 0;
369	}
370
371	static void memcg_cancel_update_list_lru_node(struct list_lru_node *nlru,
372	int old_size, int new_size)
373	{
374	/* do not bother shrinking the array back to the old size, because we
375	* cannot handle allocation failures here */
376	__memcg_destroy_list_lru_node(nlru->memcg_lrus, old_size, new_size);
377	}
378
379	static int memcg_init_list_lru(struct list_lru *lru, bool memcg_aware)
380	{
381	int i;
382
383	for (i = 0; i < nr_node_ids; i++) {
384	if (!memcg_aware)
385	lru->node[i].memcg_lrus = NULL;
386	else if (memcg_init_list_lru_node(&lru->node[i]))
387	goto fail;
388	}
389	return 0;
390	fail:
391	for (i = i - 1; i >= 0; i--)
392	memcg_destroy_list_lru_node(&lru->node[i]);
393	return -ENOMEM;
394	}
395
396	static void memcg_destroy_list_lru(struct list_lru *lru)
397	{
398	int i;
399
400	if (!list_lru_memcg_aware(lru))
401	return;
402
403	for (i = 0; i < nr_node_ids; i++)
404	memcg_destroy_list_lru_node(&lru->node[i]);
405	}
406
407	static int memcg_update_list_lru(struct list_lru *lru,
408	int old_size, int new_size)
409	{
410	int i;
411
412	if (!list_lru_memcg_aware(lru))
413	return 0;
414
415	for (i = 0; i < nr_node_ids; i++) {
416	if (memcg_update_list_lru_node(&lru->node[i],
417	old_size, new_size))
418	goto fail;
419	}
420	return 0;
421	fail:
422	for (i = i - 1; i >= 0; i--)
423	memcg_cancel_update_list_lru_node(&lru->node[i],
424	old_size, new_size);
425	return -ENOMEM;
426	}
427
428	static void memcg_cancel_update_list_lru(struct list_lru *lru,
429	int old_size, int new_size)
430	{
431	int i;
432
433	if (!list_lru_memcg_aware(lru))
434	return;
435
436	for (i = 0; i < nr_node_ids; i++)
437	memcg_cancel_update_list_lru_node(&lru->node[i],
438	old_size, new_size);
439	}
440
441	int memcg_update_all_list_lrus(int new_size)
442	{
443	int ret = 0;
444	struct list_lru *lru;
445	int old_size = memcg_nr_cache_ids;
446
447	mutex_lock(&list_lrus_mutex);
448	list_for_each_entry(lru, &list_lrus, list) {
449	ret = memcg_update_list_lru(lru, old_size, new_size);
450	if (ret)
451	goto fail;
452	}
453	out:
454	mutex_unlock(&list_lrus_mutex);
455	return ret;
456	fail:
457	list_for_each_entry_continue_reverse(lru, &list_lrus, list)
458	memcg_cancel_update_list_lru(lru, old_size, new_size);
459	goto out;
460	}
461	#else
462	static int memcg_init_list_lru(struct list_lru *lru, bool memcg_aware)
463	{
464	return 0;
465	}
466
467	static void memcg_destroy_list_lru(struct list_lru *lru)
468	{
469	}
470	#endif /* CONFIG_MEMCG_KMEM */
471
472	int __list_lru_init(struct list_lru *lru, bool memcg_aware,
473	struct lock_class_key *key)
a38e4082	474	{
3b1d58a4	475	int i;
5ca302c8	476	size_t size = sizeof(lru->node) nr_node_ids;
60d3fd32 VD	477	int err = -ENOMEM;
	478
	479	memcg_get_cache_ids();
5ca302c8 GC	480
	481	lru->node = kzalloc(size, GFP_KERNEL);
	482	if (!lru->node)
60d3fd32	483	goto out;
a38e4082	484
5ca302c8	485	for (i = 0; i < nr_node_ids; i++) {
3b1d58a4	486	spin_lock_init(&lru->node[i].lock);
449dd698 JW	487	if (key)
449dd698 JW	488	lockdep_set_class(&lru->node[i].lock, key);
60d3fd32 VD	489	init_one_lru(&lru->node[i].lru);
	490	}
	491
	492	err = memcg_init_list_lru(lru, memcg_aware);
	493	if (err) {
	494	kfree(lru->node);
	495	goto out;
3b1d58a4	496	}
60d3fd32	497
c0a5b560	498	list_lru_register(lru);
60d3fd32 VD	499	out:
	500	memcg_put_cache_ids();
	501	return err;
a38e4082	502	}
60d3fd32	503	EXPORT_SYMBOL_GPL(__list_lru_init);
5ca302c8 GC	504
	505	void list_lru_destroy(struct list_lru *lru)
	506	{
c0a5b560 VD	507	/* Already destroyed or not yet initialized? */
	508	if (!lru->node)
	509	return;
60d3fd32 VD	510
	511	memcg_get_cache_ids();
	512
c0a5b560	513	list_lru_unregister(lru);
60d3fd32 VD	514
60d3fd32 VD	515	memcg_destroy_list_lru(lru);
5ca302c8	516	kfree(lru->node);
c0a5b560	517	lru->node = NULL;
60d3fd32 VD	518
60d3fd32 VD	519	memcg_put_cache_ids();
5ca302c8 GC	520	}
5ca302c8 GC	521	EXPORT_SYMBOL_GPL(list_lru_destroy);