/* SPDX-License-Identifier: GPL-2.0 */ /* * Copyright (c) 2013 Red Hat, Inc. and Parallels Inc. All rights reserved. * Authors: David Chinner and Glauber Costa * * Generic LRU infrastructure */ #ifndef _LRU_LIST_H #define _LRU_LIST_H #include <linux/list.h> #include <linux/nodemask.h> #include <linux/shrinker.h> #include <linux/xarray.h> struct mem_cgroup; /* list_lru_walk_cb has to always return one of those */ enum lru_status { … }; struct list_lru_one { … }; struct list_lru_memcg { … }; struct list_lru_node { … } ____cacheline_aligned_in_smp; struct list_lru { … }; void list_lru_destroy(struct list_lru *lru); int __list_lru_init(struct list_lru *lru, bool memcg_aware, struct lock_class_key *key, struct shrinker *shrinker); #define list_lru_init(lru) … #define list_lru_init_memcg(lru, shrinker) … int memcg_list_lru_alloc(struct mem_cgroup *memcg, struct list_lru *lru, gfp_t gfp); void memcg_reparent_list_lrus(struct mem_cgroup *memcg, struct mem_cgroup *parent); /** * list_lru_add: add an element to the lru list's tail * @lru: the lru pointer * @item: the item to be added. * @nid: the node id of the sublist to add the item to. * @memcg: the cgroup of the sublist to add the item to. * * If the element is already part of a list, this function returns doing * nothing. Therefore the caller does not need to keep state about whether or * not the element already belongs in the list and is allowed to lazy update * it. Note however that this is valid for *a* list, not *this* list. If * the caller organize itself in a way that elements can be in more than * one type of list, it is up to the caller to fully remove the item from * the previous list (with list_lru_del() for instance) before moving it * to @lru. * * Return: true if the list was updated, false otherwise */ bool list_lru_add(struct list_lru *lru, struct list_head *item, int nid, struct mem_cgroup *memcg); /** * list_lru_add_obj: add an element to the lru list's tail * @lru: the lru pointer * @item: the item to be added. * * This function is similar to list_lru_add(), but the NUMA node and the * memcg of the sublist is determined by @item list_head. This assumption is * valid for slab objects LRU such as dentries, inodes, etc. * * Return value: true if the list was updated, false otherwise */ bool list_lru_add_obj(struct list_lru *lru, struct list_head *item); /** * list_lru_del: delete an element from the lru list * @lru: the lru pointer * @item: the item to be deleted. * @nid: the node id of the sublist to delete the item from. * @memcg: the cgroup of the sublist to delete the item from. * * This function works analogously as list_lru_add() in terms of list * manipulation. The comments about an element already pertaining to * a list are also valid for list_lru_del(). * * Return: true if the list was updated, false otherwise */ bool list_lru_del(struct list_lru *lru, struct list_head *item, int nid, struct mem_cgroup *memcg); /** * list_lru_del_obj: delete an element from the lru list * @lru: the lru pointer * @item: the item to be deleted. * * This function is similar to list_lru_del(), but the NUMA node and the * memcg of the sublist is determined by @item list_head. This assumption is * valid for slab objects LRU such as dentries, inodes, etc. * * Return value: true if the list was updated, false otherwise. */ bool list_lru_del_obj(struct list_lru *lru, struct list_head *item); /** * list_lru_count_one: return the number of objects currently held by @lru * @lru: the lru pointer. * @nid: the node id to count from. * @memcg: the cgroup to count from. * * There is no guarantee that the list is not updated while the count is being * computed. Callers that want such a guarantee need to provide an outer lock. * * Return: 0 for empty lists, otherwise the number of objects * currently held by @lru. */ unsigned long list_lru_count_one(struct list_lru *lru, int nid, struct mem_cgroup *memcg); unsigned long list_lru_count_node(struct list_lru *lru, int nid); static inline unsigned long list_lru_shrink_count(struct list_lru *lru, struct shrink_control *sc) { … } static inline unsigned long list_lru_count(struct list_lru *lru) { … } void list_lru_isolate(struct list_lru_one *list, struct list_head *item); void list_lru_isolate_move(struct list_lru_one *list, struct list_head *item, struct list_head *head); list_lru_walk_cb; /** * list_lru_walk_one: walk a @lru, isolating and disposing freeable items. * @lru: the lru pointer. * @nid: the node id to scan from. * @memcg: the cgroup to scan from. * @isolate: callback function that is responsible for deciding what to do with * the item currently being scanned * @cb_arg: opaque type that will be passed to @isolate * @nr_to_walk: how many items to scan. * * This function will scan all elements in a particular @lru, calling the * @isolate callback for each of those items, along with the current list * spinlock and a caller-provided opaque. The @isolate callback can choose to * drop the lock internally, but *must* return with the lock held. The callback * will return an enum lru_status telling the @lru infrastructure what to * do with the object being scanned. * * Please note that @nr_to_walk does not mean how many objects will be freed, * just how many objects will be scanned. * * Return: the number of objects effectively removed from the LRU. */ 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); /** * list_lru_walk_one_irq: walk a @lru, isolating and disposing freeable items. * @lru: the lru pointer. * @nid: the node id to scan from. * @memcg: the cgroup to scan from. * @isolate: callback function that is responsible for deciding what to do with * the item currently being scanned * @cb_arg: opaque type that will be passed to @isolate * @nr_to_walk: how many items to scan. * * Same as list_lru_walk_one() except that the spinlock is acquired with * spin_lock_irq(). */ 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); 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); static inline unsigned long list_lru_shrink_walk(struct list_lru *lru, struct shrink_control *sc, list_lru_walk_cb isolate, void *cb_arg) { … } static inline unsigned long list_lru_shrink_walk_irq(struct list_lru *lru, struct shrink_control *sc, list_lru_walk_cb isolate, void *cb_arg) { … } static inline unsigned long list_lru_walk(struct list_lru *lru, list_lru_walk_cb isolate, void *cb_arg, unsigned long nr_to_walk) { … } #endif /* _LRU_LIST_H */
Codebase Browser
linux