--- /dev/null
+/*
+ * 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);
+ 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--;
+ 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;
+
+ 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;
+}
+
+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 (i = 0; i < nr_node_ids; 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 (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);
Code Review / kvmfornfv.git / blobdiff