[linux.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)
{
	/*
	 * This needs node 0 to be always present, even
	 * in the systems supporting sparse numa ids.
	 */
	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 __always_inline struct mem_cgroup *mem_cgroup_from_kmem(void *ptr)
{
	struct page *page;

	if (!memcg_kmem_enabled())
		return NULL;
	page = virt_to_head_page(ptr);
	return page->mem_cgroup;
}

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);
	if (list_empty(item)) {
		l = list_lru_from_kmem(nlru, 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);
	if (!list_empty(item)) {
		l = list_lru_from_kmem(nlru, item);
		list_del_init(item);
		l->nr_items--;
		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);
	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;

	if (!memcg_aware)
		return 0;

	for_each_node(i) {
		if (memcg_init_list_lru_node(&lru->node[i]))
			goto fail;
	}
	return 0;
fail:
	for (i = i - 1; i >= 0; i--) {
		if (!lru->node[i].memcg_lrus)
			continue;
		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_each_node(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_each_node(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--) {
		if (!lru->node[i].memcg_lrus)
			continue;

		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_each_node(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;
}

static void memcg_drain_list_lru_node(struct list_lru_node *nlru,
				      int src_idx, int dst_idx)
{
	struct list_lru_one *src, *dst;

	/*
	 * 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);

	src = list_lru_from_memcg_idx(nlru, src_idx);
	dst = list_lru_from_memcg_idx(nlru, dst_idx);

	list_splice_init(&src->list, &dst->list);
	dst->nr_items += src->nr_items;
	src->nr_items = 0;

	spin_unlock_irq(&nlru->lock);
}

static void memcg_drain_list_lru(struct list_lru *lru,
				 int src_idx, int dst_idx)
{
	int i;

	if (!list_lru_memcg_aware(lru))
		return;

	for_each_node(i)
		memcg_drain_list_lru_node(&lru->node[i], src_idx, dst_idx);
}

void memcg_drain_all_list_lrus(int src_idx, int dst_idx)
{
	struct list_lru *lru;

	mutex_lock(&list_lrus_mutex);
	list_for_each_entry(lru, &list_lrus, list)
		memcg_drain_list_lru(lru, src_idx, dst_idx);
	mutex_unlock(&list_lrus_mutex);
}
#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_each_node(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	{
145949a1 R	45	/*
	46	* This needs node 0 to be always present, even
	47	* in the systems supporting sparse numa ids.
	48	*/
60d3fd32 VD	49	return !!lru->node[0].memcg_lrus;
	50	}
	51
	52	static inline struct list_lru_one *
	53	list_lru_from_memcg_idx(struct list_lru_node *nlru, int idx)
	54	{
	55	/*
	56	* The lock protects the array of per cgroup lists from relocation
	57	* (see memcg_update_list_lru_node).
	58	*/
	59	lockdep_assert_held(&nlru->lock);
	60	if (nlru->memcg_lrus && idx >= 0)
	61	return nlru->memcg_lrus->lru[idx];
	62
	63	return &nlru->lru;
	64	}
	65
df406551 VD	66	static __always_inline struct mem_cgroup mem_cgroup_from_kmem(void ptr)
	67	{
	68	struct page *page;
	69
	70	if (!memcg_kmem_enabled())
	71	return NULL;
	72	page = virt_to_head_page(ptr);
	73	return page->mem_cgroup;
	74	}
	75
60d3fd32 VD	76	static inline struct list_lru_one *
	77	list_lru_from_kmem(struct list_lru_node nlru, void ptr)
	78	{
	79	struct mem_cgroup *memcg;
	80
	81	if (!nlru->memcg_lrus)
	82	return &nlru->lru;
	83
	84	memcg = mem_cgroup_from_kmem(ptr);
	85	if (!memcg)
	86	return &nlru->lru;
	87
	88	return list_lru_from_memcg_idx(nlru, memcg_cache_id(memcg));
	89	}
	90	#else
	91	static inline bool list_lru_memcg_aware(struct list_lru *lru)
	92	{
	93	return false;
	94	}
	95
	96	static inline struct list_lru_one *
	97	list_lru_from_memcg_idx(struct list_lru_node *nlru, int idx)
	98	{
	99	return &nlru->lru;
	100	}
	101
	102	static inline struct list_lru_one *
	103	list_lru_from_kmem(struct list_lru_node nlru, void ptr)
	104	{
	105	return &nlru->lru;
	106	}
	107	#endif /* CONFIG_MEMCG_KMEM */
	108
a38e4082 DC	109	bool list_lru_add(struct list_lru lru, struct list_head item)
a38e4082 DC	110	{
3b1d58a4 DC	111	int nid = page_to_nid(virt_to_page(item));
3b1d58a4 DC	112	struct list_lru_node *nlru = &lru->node[nid];
60d3fd32	113	struct list_lru_one *l;
3b1d58a4 DC	114
3b1d58a4 DC	115	spin_lock(&nlru->lock);
a38e4082	116	if (list_empty(item)) {
26f5d760	117	l = list_lru_from_kmem(nlru, item);
60d3fd32 VD	118	list_add_tail(item, &l->list);
60d3fd32 VD	119	l->nr_items++;
3b1d58a4	120	spin_unlock(&nlru->lock);
a38e4082 DC	121	return true;
a38e4082 DC	122	}
3b1d58a4	123	spin_unlock(&nlru->lock);
a38e4082 DC	124	return false;
	125	}
	126	EXPORT_SYMBOL_GPL(list_lru_add);
	127
	128	bool list_lru_del(struct list_lru lru, struct list_head item)
	129	{
3b1d58a4 DC	130	int nid = page_to_nid(virt_to_page(item));
3b1d58a4 DC	131	struct list_lru_node *nlru = &lru->node[nid];
60d3fd32	132	struct list_lru_one *l;
3b1d58a4 DC	133
3b1d58a4 DC	134	spin_lock(&nlru->lock);
a38e4082	135	if (!list_empty(item)) {
26f5d760	136	l = list_lru_from_kmem(nlru, item);
a38e4082	137	list_del_init(item);
60d3fd32	138	l->nr_items--;
3b1d58a4	139	spin_unlock(&nlru->lock);
a38e4082 DC	140	return true;
a38e4082 DC	141	}
3b1d58a4	142	spin_unlock(&nlru->lock);
a38e4082 DC	143	return false;
	144	}
	145	EXPORT_SYMBOL_GPL(list_lru_del);
	146
3f97b163 VD	147	void list_lru_isolate(struct list_lru_one list, struct list_head item)
	148	{
	149	list_del_init(item);
	150	list->nr_items--;
	151	}
	152	EXPORT_SYMBOL_GPL(list_lru_isolate);
	153
	154	void list_lru_isolate_move(struct list_lru_one list, struct list_head item,
	155	struct list_head *head)
	156	{
	157	list_move(item, head);
	158	list->nr_items--;
	159	}
	160	EXPORT_SYMBOL_GPL(list_lru_isolate_move);
	161
60d3fd32 VD	162	static unsigned long __list_lru_count_one(struct list_lru *lru,
60d3fd32 VD	163	int nid, int memcg_idx)
a38e4082	164	{
6a4f496f	165	struct list_lru_node *nlru = &lru->node[nid];
60d3fd32 VD	166	struct list_lru_one *l;
60d3fd32 VD	167	unsigned long count;
3b1d58a4	168
6a4f496f	169	spin_lock(&nlru->lock);
60d3fd32	170	l = list_lru_from_memcg_idx(nlru, memcg_idx);
60d3fd32	171	count = l->nr_items;
6a4f496f	172	spin_unlock(&nlru->lock);
3b1d58a4 DC	173
	174	return count;
	175	}
60d3fd32 VD	176
	177	unsigned long list_lru_count_one(struct list_lru *lru,
	178	int nid, struct mem_cgroup *memcg)
	179	{
	180	return __list_lru_count_one(lru, nid, memcg_cache_id(memcg));
	181	}
	182	EXPORT_SYMBOL_GPL(list_lru_count_one);
	183
	184	unsigned long list_lru_count_node(struct list_lru *lru, int nid)
	185	{
	186	long count = 0;
	187	int memcg_idx;
	188
	189	count += __list_lru_count_one(lru, nid, -1);
	190	if (list_lru_memcg_aware(lru)) {
	191	for_each_memcg_cache_index(memcg_idx)
	192	count += __list_lru_count_one(lru, nid, memcg_idx);
	193	}
	194	return count;
	195	}
6a4f496f	196	EXPORT_SYMBOL_GPL(list_lru_count_node);
3b1d58a4	197
60d3fd32 VD	198	static unsigned long
	199	__list_lru_walk_one(struct list_lru *lru, int nid, int memcg_idx,
	200	list_lru_walk_cb isolate, void *cb_arg,
	201	unsigned long *nr_to_walk)
3b1d58a4 DC	202	{
3b1d58a4 DC	203
60d3fd32 VD	204	struct list_lru_node *nlru = &lru->node[nid];
60d3fd32 VD	205	struct list_lru_one *l;
a38e4082	206	struct list_head item, n;
3b1d58a4	207	unsigned long isolated = 0;
a38e4082	208
3b1d58a4	209	spin_lock(&nlru->lock);
60d3fd32	210	l = list_lru_from_memcg_idx(nlru, memcg_idx);
a38e4082	211	restart:
60d3fd32	212	list_for_each_safe(item, n, &l->list) {
a38e4082	213	enum lru_status ret;
5cedf721 DC	214
	215	/*
	216	* decrement nr_to_walk first so that we don't livelock if we
	217	* get stuck on large numbesr of LRU_RETRY items
	218	*/
c56b097a	219	if (!*nr_to_walk)
5cedf721	220	break;
c56b097a	221	--*nr_to_walk;
5cedf721	222
3f97b163	223	ret = isolate(item, l, &nlru->lock, cb_arg);
a38e4082	224	switch (ret) {
449dd698 JW	225	case LRU_REMOVED_RETRY:
449dd698 JW	226	assert_spin_locked(&nlru->lock);
a38e4082	227	case LRU_REMOVED:
3b1d58a4	228	isolated++;
449dd698 JW	229	/*
	230	* If the lru lock has been dropped, our list
	231	* traversal is now invalid and so we have to
	232	* restart from scratch.
	233	*/
	234	if (ret == LRU_REMOVED_RETRY)
	235	goto restart;
a38e4082 DC	236	break;
a38e4082 DC	237	case LRU_ROTATE:
60d3fd32	238	list_move_tail(item, &l->list);
a38e4082 DC	239	break;
	240	case LRU_SKIP:
	241	break;
	242	case LRU_RETRY:
5cedf721 DC	243	/*
	244	* The lru lock has been dropped, our list traversal is
	245	* now invalid and so we have to restart from scratch.
	246	*/
449dd698	247	assert_spin_locked(&nlru->lock);
a38e4082 DC	248	goto restart;
	249	default:
	250	BUG();
	251	}
a38e4082	252	}
3b1d58a4 DC	253
	254	spin_unlock(&nlru->lock);
	255	return isolated;
	256	}
60d3fd32 VD	257
	258	unsigned long
	259	list_lru_walk_one(struct list_lru lru, int nid, struct mem_cgroup memcg,
	260	list_lru_walk_cb isolate, void *cb_arg,
	261	unsigned long *nr_to_walk)
	262	{
	263	return __list_lru_walk_one(lru, nid, memcg_cache_id(memcg),
	264	isolate, cb_arg, nr_to_walk);
	265	}
	266	EXPORT_SYMBOL_GPL(list_lru_walk_one);
	267
	268	unsigned long list_lru_walk_node(struct list_lru *lru, int nid,
	269	list_lru_walk_cb isolate, void *cb_arg,
	270	unsigned long *nr_to_walk)
	271	{
	272	long isolated = 0;
	273	int memcg_idx;
	274
	275	isolated += __list_lru_walk_one(lru, nid, -1, isolate, cb_arg,
	276	nr_to_walk);
	277	if (*nr_to_walk > 0 && list_lru_memcg_aware(lru)) {
	278	for_each_memcg_cache_index(memcg_idx) {
	279	isolated += __list_lru_walk_one(lru, nid, memcg_idx,
	280	isolate, cb_arg, nr_to_walk);
	281	if (*nr_to_walk <= 0)
	282	break;
	283	}
	284	}
	285	return isolated;
	286	}
3b1d58a4 DC	287	EXPORT_SYMBOL_GPL(list_lru_walk_node);
3b1d58a4 DC	288
60d3fd32 VD	289	static void init_one_lru(struct list_lru_one *l)
	290	{
	291	INIT_LIST_HEAD(&l->list);
	292	l->nr_items = 0;
	293	}
	294
	295	#ifdef CONFIG_MEMCG_KMEM
	296	static void __memcg_destroy_list_lru_node(struct list_lru_memcg *memcg_lrus,
	297	int begin, int end)
	298	{
	299	int i;
	300
	301	for (i = begin; i < end; i++)
	302	kfree(memcg_lrus->lru[i]);
	303	}
	304
	305	static int __memcg_init_list_lru_node(struct list_lru_memcg *memcg_lrus,
	306	int begin, int end)
	307	{
	308	int i;
	309
	310	for (i = begin; i < end; i++) {
	311	struct list_lru_one *l;
	312
	313	l = kmalloc(sizeof(struct list_lru_one), GFP_KERNEL);
	314	if (!l)
	315	goto fail;
	316
	317	init_one_lru(l);
	318	memcg_lrus->lru[i] = l;
	319	}
	320	return 0;
	321	fail:
	322	__memcg_destroy_list_lru_node(memcg_lrus, begin, i - 1);
	323	return -ENOMEM;
	324	}
	325
	326	static int memcg_init_list_lru_node(struct list_lru_node *nlru)
	327	{
	328	int size = memcg_nr_cache_ids;
	329
	330	nlru->memcg_lrus = kmalloc(size * sizeof(void *), GFP_KERNEL);
	331	if (!nlru->memcg_lrus)
	332	return -ENOMEM;
	333
	334	if (__memcg_init_list_lru_node(nlru->memcg_lrus, 0, size)) {
	335	kfree(nlru->memcg_lrus);
	336	return -ENOMEM;
	337	}
	338
	339	return 0;
	340	}
	341
	342	static void memcg_destroy_list_lru_node(struct list_lru_node *nlru)
	343	{
	344	__memcg_destroy_list_lru_node(nlru->memcg_lrus, 0, memcg_nr_cache_ids);
	345	kfree(nlru->memcg_lrus);
	346	}
	347
	348	static int memcg_update_list_lru_node(struct list_lru_node *nlru,
	349	int old_size, int new_size)
	350	{
	351	struct list_lru_memcg old, new;
	352
353	BUG_ON(old_size > new_size);
354
355	old = nlru->memcg_lrus;
356	new = kmalloc(new_size * sizeof(void *), GFP_KERNEL);
357	if (!new)
358	return -ENOMEM;
359
360	if (__memcg_init_list_lru_node(new, old_size, new_size)) {
361	kfree(new);
362	return -ENOMEM;
363	}
364
365	memcpy(new, old, old_size * sizeof(void *));
366
367	/*
368	* The lock guarantees that we won't race with a reader
369	* (see list_lru_from_memcg_idx).
370	*
371	* Since list_lru_{add,del} may be called under an IRQ-safe lock,
372	* we have to use IRQ-safe primitives here to avoid deadlock.
373	*/
374	spin_lock_irq(&nlru->lock);
375	nlru->memcg_lrus = new;
376	spin_unlock_irq(&nlru->lock);
377
378	kfree(old);
379	return 0;
380	}
381
382	static void memcg_cancel_update_list_lru_node(struct list_lru_node *nlru,
383	int old_size, int new_size)
384	{
385	/* do not bother shrinking the array back to the old size, because we
386	* cannot handle allocation failures here */
387	__memcg_destroy_list_lru_node(nlru->memcg_lrus, old_size, new_size);
388	}
389
390	static int memcg_init_list_lru(struct list_lru *lru, bool memcg_aware)
391	{
392	int i;
393
145949a1 R	394	if (!memcg_aware)
	395	return 0;
	396
	397	for_each_node(i) {
	398	if (memcg_init_list_lru_node(&lru->node[i]))
60d3fd32 VD	399	goto fail;
	400	}
	401	return 0;
	402	fail:
145949a1 R	403	for (i = i - 1; i >= 0; i--) {
	404	if (!lru->node[i].memcg_lrus)
	405	continue;
60d3fd32	406	memcg_destroy_list_lru_node(&lru->node[i]);
145949a1	407	}
60d3fd32 VD	408	return -ENOMEM;
	409	}
	410
	411	static void memcg_destroy_list_lru(struct list_lru *lru)
	412	{
	413	int i;
	414
	415	if (!list_lru_memcg_aware(lru))
	416	return;
	417
145949a1	418	for_each_node(i)
60d3fd32 VD	419	memcg_destroy_list_lru_node(&lru->node[i]);
	420	}
	421
	422	static int memcg_update_list_lru(struct list_lru *lru,
	423	int old_size, int new_size)
	424	{
	425	int i;
	426
	427	if (!list_lru_memcg_aware(lru))
	428	return 0;
	429
145949a1	430	for_each_node(i) {
60d3fd32 VD	431	if (memcg_update_list_lru_node(&lru->node[i],
	432	old_size, new_size))
	433	goto fail;
	434	}
	435	return 0;
	436	fail:
145949a1 R	437	for (i = i - 1; i >= 0; i--) {
	438	if (!lru->node[i].memcg_lrus)
	439	continue;
	440
60d3fd32 VD	441	memcg_cancel_update_list_lru_node(&lru->node[i],
60d3fd32 VD	442	old_size, new_size);
145949a1	443	}
60d3fd32 VD	444	return -ENOMEM;
	445	}
	446
	447	static void memcg_cancel_update_list_lru(struct list_lru *lru,
	448	int old_size, int new_size)
	449	{
	450	int i;
	451
	452	if (!list_lru_memcg_aware(lru))
	453	return;
	454
145949a1	455	for_each_node(i)
60d3fd32 VD	456	memcg_cancel_update_list_lru_node(&lru->node[i],
	457	old_size, new_size);
	458	}
	459
	460	int memcg_update_all_list_lrus(int new_size)
	461	{
	462	int ret = 0;
	463	struct list_lru *lru;
	464	int old_size = memcg_nr_cache_ids;
	465
	466	mutex_lock(&list_lrus_mutex);
	467	list_for_each_entry(lru, &list_lrus, list) {
	468	ret = memcg_update_list_lru(lru, old_size, new_size);
	469	if (ret)
	470	goto fail;
	471	}
	472	out:
	473	mutex_unlock(&list_lrus_mutex);
	474	return ret;
	475	fail:
	476	list_for_each_entry_continue_reverse(lru, &list_lrus, list)
	477	memcg_cancel_update_list_lru(lru, old_size, new_size);
	478	goto out;
	479	}
2788cf0c VD	480
	481	static void memcg_drain_list_lru_node(struct list_lru_node *nlru,
	482	int src_idx, int dst_idx)
	483	{
	484	struct list_lru_one src, dst;
	485
	486	/*
	487	* Since list_lru_{add,del} may be called under an IRQ-safe lock,
	488	* we have to use IRQ-safe primitives here to avoid deadlock.
	489	*/
	490	spin_lock_irq(&nlru->lock);
	491
	492	src = list_lru_from_memcg_idx(nlru, src_idx);
	493	dst = list_lru_from_memcg_idx(nlru, dst_idx);
	494
	495	list_splice_init(&src->list, &dst->list);
	496	dst->nr_items += src->nr_items;
	497	src->nr_items = 0;
	498
	499	spin_unlock_irq(&nlru->lock);
	500	}
	501
	502	static void memcg_drain_list_lru(struct list_lru *lru,
	503	int src_idx, int dst_idx)
	504	{
	505	int i;
	506
	507	if (!list_lru_memcg_aware(lru))
	508	return;
	509
145949a1	510	for_each_node(i)
2788cf0c VD	511	memcg_drain_list_lru_node(&lru->node[i], src_idx, dst_idx);
	512	}
	513
	514	void memcg_drain_all_list_lrus(int src_idx, int dst_idx)
	515	{
	516	struct list_lru *lru;
	517
	518	mutex_lock(&list_lrus_mutex);
	519	list_for_each_entry(lru, &list_lrus, list)
	520	memcg_drain_list_lru(lru, src_idx, dst_idx);
	521	mutex_unlock(&list_lrus_mutex);
	522	}
60d3fd32 VD	523	#else
	524	static int memcg_init_list_lru(struct list_lru *lru, bool memcg_aware)
	525	{
	526	return 0;
	527	}
	528
	529	static void memcg_destroy_list_lru(struct list_lru *lru)
	530	{
	531	}
	532	#endif /* CONFIG_MEMCG_KMEM */
	533
	534	int __list_lru_init(struct list_lru *lru, bool memcg_aware,
	535	struct lock_class_key *key)
a38e4082	536	{
3b1d58a4	537	int i;
5ca302c8	538	size_t size = sizeof(lru->node) nr_node_ids;
60d3fd32 VD	539	int err = -ENOMEM;
	540
	541	memcg_get_cache_ids();
5ca302c8 GC	542
	543	lru->node = kzalloc(size, GFP_KERNEL);
	544	if (!lru->node)
60d3fd32	545	goto out;
a38e4082	546
145949a1	547	for_each_node(i) {
3b1d58a4	548	spin_lock_init(&lru->node[i].lock);
449dd698 JW	549	if (key)
449dd698 JW	550	lockdep_set_class(&lru->node[i].lock, key);
60d3fd32 VD	551	init_one_lru(&lru->node[i].lru);
	552	}
	553
	554	err = memcg_init_list_lru(lru, memcg_aware);
	555	if (err) {
	556	kfree(lru->node);
	557	goto out;
3b1d58a4	558	}
60d3fd32	559
c0a5b560	560	list_lru_register(lru);
60d3fd32 VD	561	out:
	562	memcg_put_cache_ids();
	563	return err;
a38e4082	564	}
60d3fd32	565	EXPORT_SYMBOL_GPL(__list_lru_init);
5ca302c8 GC	566
	567	void list_lru_destroy(struct list_lru *lru)
	568	{
c0a5b560 VD	569	/* Already destroyed or not yet initialized? */
	570	if (!lru->node)
	571	return;
60d3fd32 VD	572
	573	memcg_get_cache_ids();
	574
c0a5b560	575	list_lru_unregister(lru);
60d3fd32 VD	576
60d3fd32 VD	577	memcg_destroy_list_lru(lru);
5ca302c8	578	kfree(lru->node);
c0a5b560	579	lru->node = NULL;
60d3fd32 VD	580
60d3fd32 VD	581	memcg_put_cache_ids();
5ca302c8 GC	582	}
5ca302c8 GC	583	EXPORT_SYMBOL_GPL(list_lru_destroy);