Adding upstream version 6.6.15.upstream/6.6.15

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

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);