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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-11 08:27:49 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-11 08:27:49 +0000
commitace9429bb58fd418f0c81d4c2835699bddf6bde6 (patch)
treeb2d64bc10158fdd5497876388cd68142ca374ed3 /mm/list_lru.c
parentInitial commit. (diff)
downloadlinux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.tar.xz
linux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.zip
Adding upstream version 6.6.15.upstream/6.6.15
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'mm/list_lru.c')
-rw-r--r--mm/list_lru.c605
1 files changed, 605 insertions, 0 deletions
diff --git a/mm/list_lru.c b/mm/list_lru.c
new file mode 100644
index 0000000000..a05e5bef3b
--- /dev/null
+++ b/mm/list_lru.c
@@ -0,0 +1,605 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * 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>
+#include "slab.h"
+#include "internal.h"
+
+#ifdef CONFIG_MEMCG_KMEM
+static LIST_HEAD(memcg_list_lrus);
+static DEFINE_MUTEX(list_lrus_mutex);
+
+static inline bool list_lru_memcg_aware(struct list_lru *lru)
+{
+ return lru->memcg_aware;
+}
+
+static void list_lru_register(struct list_lru *lru)
+{
+ if (!list_lru_memcg_aware(lru))
+ return;
+
+ mutex_lock(&list_lrus_mutex);
+ list_add(&lru->list, &memcg_list_lrus);
+ mutex_unlock(&list_lrus_mutex);
+}
+
+static void list_lru_unregister(struct list_lru *lru)
+{
+ if (!list_lru_memcg_aware(lru))
+ return;
+
+ mutex_lock(&list_lrus_mutex);
+ list_del(&lru->list);
+ mutex_unlock(&list_lrus_mutex);
+}
+
+static int lru_shrinker_id(struct list_lru *lru)
+{
+ return lru->shrinker_id;
+}
+
+static inline struct list_lru_one *
+list_lru_from_memcg_idx(struct list_lru *lru, int nid, int idx)
+{
+ if (list_lru_memcg_aware(lru) && idx >= 0) {
+ struct list_lru_memcg *mlru = xa_load(&lru->xa, idx);
+
+ return mlru ? &mlru->node[nid] : NULL;
+ }
+ return &lru->node[nid].lru;
+}
+
+static inline struct list_lru_one *
+list_lru_from_kmem(struct list_lru *lru, int nid, void *ptr,
+ struct mem_cgroup **memcg_ptr)
+{
+ struct list_lru_node *nlru = &lru->node[nid];
+ struct list_lru_one *l = &nlru->lru;
+ struct mem_cgroup *memcg = NULL;
+
+ if (!list_lru_memcg_aware(lru))
+ goto out;
+
+ memcg = mem_cgroup_from_slab_obj(ptr);
+ if (!memcg)
+ goto out;
+
+ l = list_lru_from_memcg_idx(lru, nid, memcg_kmem_id(memcg));
+out:
+ if (memcg_ptr)
+ *memcg_ptr = memcg;
+ return l;
+}
+#else
+static void list_lru_register(struct list_lru *lru)
+{
+}
+
+static void list_lru_unregister(struct list_lru *lru)
+{
+}
+
+static int lru_shrinker_id(struct list_lru *lru)
+{
+ return -1;
+}
+
+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 *lru, int nid, int idx)
+{
+ return &lru->node[nid].lru;
+}
+
+static inline struct list_lru_one *
+list_lru_from_kmem(struct list_lru *lru, int nid, void *ptr,
+ struct mem_cgroup **memcg_ptr)
+{
+ if (memcg_ptr)
+ *memcg_ptr = NULL;
+ return &lru->node[nid].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 mem_cgroup *memcg;
+ struct list_lru_one *l;
+
+ spin_lock(&nlru->lock);
+ if (list_empty(item)) {
+ l = list_lru_from_kmem(lru, nid, item, &memcg);
+ list_add_tail(item, &l->list);
+ /* Set shrinker bit if the first element was added */
+ if (!l->nr_items++)
+ set_shrinker_bit(memcg, nid,
+ lru_shrinker_id(lru));
+ nlru->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(lru, nid, item, NULL);
+ list_del_init(item);
+ l->nr_items--;
+ nlru->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);
+
+unsigned long list_lru_count_one(struct list_lru *lru,
+ int nid, struct mem_cgroup *memcg)
+{
+ struct list_lru_one *l;
+ long count;
+
+ rcu_read_lock();
+ l = list_lru_from_memcg_idx(lru, nid, memcg_kmem_id(memcg));
+ count = l ? READ_ONCE(l->nr_items) : 0;
+ rcu_read_unlock();
+
+ if (unlikely(count < 0))
+ count = 0;
+
+ return count;
+}
+EXPORT_SYMBOL_GPL(list_lru_count_one);
+
+unsigned long list_lru_count_node(struct list_lru *lru, int nid)
+{
+ struct list_lru_node *nlru;
+
+ nlru = &lru->node[nid];
+ return nlru->nr_items;
+}
+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;
+
+restart:
+ l = list_lru_from_memcg_idx(lru, nid, memcg_idx);
+ if (!l)
+ goto out;
+
+ 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 numbers 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);
+ fallthrough;
+ case LRU_REMOVED:
+ isolated++;
+ nlru->nr_items--;
+ /*
+ * 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();
+ }
+ }
+out:
+ 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)
+{
+ struct list_lru_node *nlru = &lru->node[nid];
+ unsigned long ret;
+
+ spin_lock(&nlru->lock);
+ ret = __list_lru_walk_one(lru, nid, memcg_kmem_id(memcg), isolate,
+ cb_arg, nr_to_walk);
+ spin_unlock(&nlru->lock);
+ return ret;
+}
+EXPORT_SYMBOL_GPL(list_lru_walk_one);
+
+unsigned long
+list_lru_walk_one_irq(struct list_lru *lru, int nid, struct mem_cgroup *memcg,
+ list_lru_walk_cb isolate, void *cb_arg,
+ unsigned long *nr_to_walk)
+{
+ struct list_lru_node *nlru = &lru->node[nid];
+ unsigned long ret;
+
+ spin_lock_irq(&nlru->lock);
+ ret = __list_lru_walk_one(lru, nid, memcg_kmem_id(memcg), isolate,
+ cb_arg, nr_to_walk);
+ spin_unlock_irq(&nlru->lock);
+ return ret;
+}
+
+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;
+
+ isolated += list_lru_walk_one(lru, nid, NULL, isolate, cb_arg,
+ nr_to_walk);
+
+#ifdef CONFIG_MEMCG_KMEM
+ if (*nr_to_walk > 0 && list_lru_memcg_aware(lru)) {
+ struct list_lru_memcg *mlru;
+ unsigned long index;
+
+ xa_for_each(&lru->xa, index, mlru) {
+ struct list_lru_node *nlru = &lru->node[nid];
+
+ spin_lock(&nlru->lock);
+ isolated += __list_lru_walk_one(lru, nid, index,
+ isolate, cb_arg,
+ nr_to_walk);
+ spin_unlock(&nlru->lock);
+
+ if (*nr_to_walk <= 0)
+ break;
+ }
+ }
+#endif
+
+ 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 struct list_lru_memcg *memcg_init_list_lru_one(gfp_t gfp)
+{
+ int nid;
+ struct list_lru_memcg *mlru;
+
+ mlru = kmalloc(struct_size(mlru, node, nr_node_ids), gfp);
+ if (!mlru)
+ return NULL;
+
+ for_each_node(nid)
+ init_one_lru(&mlru->node[nid]);
+
+ return mlru;
+}
+
+static void memcg_list_lru_free(struct list_lru *lru, int src_idx)
+{
+ struct list_lru_memcg *mlru = xa_erase_irq(&lru->xa, src_idx);
+
+ /*
+ * The __list_lru_walk_one() can walk the list of this node.
+ * We need kvfree_rcu() here. And the walking of the list
+ * is under lru->node[nid]->lock, which can serve as a RCU
+ * read-side critical section.
+ */
+ if (mlru)
+ kvfree_rcu(mlru, rcu);
+}
+
+static inline void memcg_init_list_lru(struct list_lru *lru, bool memcg_aware)
+{
+ if (memcg_aware)
+ xa_init_flags(&lru->xa, XA_FLAGS_LOCK_IRQ);
+ lru->memcg_aware = memcg_aware;
+}
+
+static void memcg_destroy_list_lru(struct list_lru *lru)
+{
+ XA_STATE(xas, &lru->xa, 0);
+ struct list_lru_memcg *mlru;
+
+ if (!list_lru_memcg_aware(lru))
+ return;
+
+ xas_lock_irq(&xas);
+ xas_for_each(&xas, mlru, ULONG_MAX) {
+ kfree(mlru);
+ xas_store(&xas, NULL);
+ }
+ xas_unlock_irq(&xas);
+}
+
+static void memcg_reparent_list_lru_node(struct list_lru *lru, int nid,
+ int src_idx, struct mem_cgroup *dst_memcg)
+{
+ struct list_lru_node *nlru = &lru->node[nid];
+ int dst_idx = dst_memcg->kmemcg_id;
+ 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(lru, nid, src_idx);
+ if (!src)
+ goto out;
+ dst = list_lru_from_memcg_idx(lru, nid, dst_idx);
+
+ list_splice_init(&src->list, &dst->list);
+
+ if (src->nr_items) {
+ dst->nr_items += src->nr_items;
+ set_shrinker_bit(dst_memcg, nid, lru_shrinker_id(lru));
+ src->nr_items = 0;
+ }
+out:
+ spin_unlock_irq(&nlru->lock);
+}
+
+static void memcg_reparent_list_lru(struct list_lru *lru,
+ int src_idx, struct mem_cgroup *dst_memcg)
+{
+ int i;
+
+ for_each_node(i)
+ memcg_reparent_list_lru_node(lru, i, src_idx, dst_memcg);
+
+ memcg_list_lru_free(lru, src_idx);
+}
+
+void memcg_reparent_list_lrus(struct mem_cgroup *memcg, struct mem_cgroup *parent)
+{
+ struct cgroup_subsys_state *css;
+ struct list_lru *lru;
+ int src_idx = memcg->kmemcg_id;
+
+ /*
+ * Change kmemcg_id of this cgroup and all its descendants to the
+ * parent's id, and then move all entries from this cgroup's list_lrus
+ * to ones of the parent.
+ *
+ * After we have finished, all list_lrus corresponding to this cgroup
+ * are guaranteed to remain empty. So we can safely free this cgroup's
+ * list lrus in memcg_list_lru_free().
+ *
+ * Changing ->kmemcg_id to the parent can prevent memcg_list_lru_alloc()
+ * from allocating list lrus for this cgroup after memcg_list_lru_free()
+ * call.
+ */
+ rcu_read_lock();
+ css_for_each_descendant_pre(css, &memcg->css) {
+ struct mem_cgroup *child;
+
+ child = mem_cgroup_from_css(css);
+ WRITE_ONCE(child->kmemcg_id, parent->kmemcg_id);
+ }
+ rcu_read_unlock();
+
+ mutex_lock(&list_lrus_mutex);
+ list_for_each_entry(lru, &memcg_list_lrus, list)
+ memcg_reparent_list_lru(lru, src_idx, parent);
+ mutex_unlock(&list_lrus_mutex);
+}
+
+static inline bool memcg_list_lru_allocated(struct mem_cgroup *memcg,
+ struct list_lru *lru)
+{
+ int idx = memcg->kmemcg_id;
+
+ return idx < 0 || xa_load(&lru->xa, idx);
+}
+
+int memcg_list_lru_alloc(struct mem_cgroup *memcg, struct list_lru *lru,
+ gfp_t gfp)
+{
+ int i;
+ unsigned long flags;
+ struct list_lru_memcg_table {
+ struct list_lru_memcg *mlru;
+ struct mem_cgroup *memcg;
+ } *table;
+ XA_STATE(xas, &lru->xa, 0);
+
+ if (!list_lru_memcg_aware(lru) || memcg_list_lru_allocated(memcg, lru))
+ return 0;
+
+ gfp &= GFP_RECLAIM_MASK;
+ table = kmalloc_array(memcg->css.cgroup->level, sizeof(*table), gfp);
+ if (!table)
+ return -ENOMEM;
+
+ /*
+ * Because the list_lru can be reparented to the parent cgroup's
+ * list_lru, we should make sure that this cgroup and all its
+ * ancestors have allocated list_lru_memcg.
+ */
+ for (i = 0; memcg; memcg = parent_mem_cgroup(memcg), i++) {
+ if (memcg_list_lru_allocated(memcg, lru))
+ break;
+
+ table[i].memcg = memcg;
+ table[i].mlru = memcg_init_list_lru_one(gfp);
+ if (!table[i].mlru) {
+ while (i--)
+ kfree(table[i].mlru);
+ kfree(table);
+ return -ENOMEM;
+ }
+ }
+
+ xas_lock_irqsave(&xas, flags);
+ while (i--) {
+ int index = READ_ONCE(table[i].memcg->kmemcg_id);
+ struct list_lru_memcg *mlru = table[i].mlru;
+
+ xas_set(&xas, index);
+retry:
+ if (unlikely(index < 0 || xas_error(&xas) || xas_load(&xas))) {
+ kfree(mlru);
+ } else {
+ xas_store(&xas, mlru);
+ if (xas_error(&xas) == -ENOMEM) {
+ xas_unlock_irqrestore(&xas, flags);
+ if (xas_nomem(&xas, gfp))
+ xas_set_err(&xas, 0);
+ xas_lock_irqsave(&xas, flags);
+ /*
+ * The xas lock has been released, this memcg
+ * can be reparented before us. So reload
+ * memcg id. More details see the comments
+ * in memcg_reparent_list_lrus().
+ */
+ index = READ_ONCE(table[i].memcg->kmemcg_id);
+ if (index < 0)
+ xas_set_err(&xas, 0);
+ else if (!xas_error(&xas) && index != xas.xa_index)
+ xas_set(&xas, index);
+ goto retry;
+ }
+ }
+ }
+ /* xas_nomem() is used to free memory instead of memory allocation. */
+ if (xas.xa_alloc)
+ xas_nomem(&xas, gfp);
+ xas_unlock_irqrestore(&xas, flags);
+ kfree(table);
+
+ return xas_error(&xas);
+}
+#else
+static inline void memcg_init_list_lru(struct list_lru *lru, bool memcg_aware)
+{
+}
+
+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, struct shrinker *shrinker)
+{
+ int i;
+
+#ifdef CONFIG_MEMCG_KMEM
+ if (shrinker)
+ lru->shrinker_id = shrinker->id;
+ else
+ lru->shrinker_id = -1;
+#endif
+
+ lru->node = kcalloc(nr_node_ids, sizeof(*lru->node), GFP_KERNEL);
+ if (!lru->node)
+ return -ENOMEM;
+
+ 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);
+ }
+
+ memcg_init_list_lru(lru, memcg_aware);
+ list_lru_register(lru);
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(__list_lru_init);
+
+void list_lru_destroy(struct list_lru *lru)
+{
+ /* Already destroyed or not yet initialized? */
+ if (!lru->node)
+ return;
+
+ list_lru_unregister(lru);
+
+ memcg_destroy_list_lru(lru);
+ kfree(lru->node);
+ lru->node = NULL;
+
+#ifdef CONFIG_MEMCG_KMEM
+ lru->shrinker_id = -1;
+#endif
+}
+EXPORT_SYMBOL_GPL(list_lru_destroy);