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Release 4.12 include/linux/list_lru.h

Directory: include/linux
 * 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>

struct mem_cgroup;

/* list_lru_walk_cb has to always return one of those */

enum lru_status {
LRU_REMOVED,		/* item removed from list */
LRU_REMOVED_RETRY,	/* item removed, but lock has been
                                   dropped and reacquired */
LRU_ROTATE,		/* item referenced, give another pass */
LRU_SKIP,		/* item cannot be locked, skip */
LRU_RETRY,		/* item not freeable. May drop the lock
                                   internally, but has to return locked. */

struct list_lru_one {
struct list_head	list;
	/* may become negative during memcg reparenting */
long			nr_items;

struct list_lru_memcg {
	/* array of per cgroup lists, indexed by memcg_cache_id */
struct list_lru_one	*lru[0];

struct list_lru_node {
	/* protects all lists on the node, including per cgroup */
spinlock_t		lock;
	/* global list, used for the root cgroup in cgroup aware lrus */
struct list_lru_one	lru;
#if defined(CONFIG_MEMCG) && !defined(CONFIG_SLOB)
	/* for cgroup aware lrus points to per cgroup lists, otherwise NULL */
struct list_lru_memcg	*memcg_lrus;

} ____cacheline_aligned_in_smp;

struct list_lru {
struct list_lru_node	*node;
#if defined(CONFIG_MEMCG) && !defined(CONFIG_SLOB)
struct list_head	list;

void list_lru_destroy(struct list_lru *lru);
int __list_lru_init(struct list_lru *lru, bool memcg_aware,
		    struct lock_class_key *key);

#define list_lru_init(lru)		__list_lru_init((lru), false, NULL)

#define list_lru_init_key(lru, key)	__list_lru_init((lru), false, (key))

#define list_lru_init_memcg(lru)	__list_lru_init((lru), true, NULL)

int memcg_update_all_list_lrus(int num_memcgs);
void memcg_drain_all_list_lrus(int src_idx, int dst_idx);

 * list_lru_add: add an element to the lru list's tail
 * @list_lru: the lru pointer
 * @item: the item to be added.
 * 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 @list_lru
 * Return value: true if the list was updated, false otherwise
bool list_lru_add(struct list_lru *lru, struct list_head *item);

 * list_lru_del: delete an element to the lru list
 * @list_lru: the lru pointer
 * @item: the item to be deleted.
 * 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 value: true if the list was updated, false otherwise
bool list_lru_del(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.
 * Always return a non-negative number, 0 for empty lists. 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.
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) { return list_lru_count_one(lru, sc->nid, sc->memcg); }


Vladimir Davydov32100.00%2100.00%

static inline unsigned long list_lru_count(struct list_lru *lru) { long count = 0; int nid; for_each_node_state(nid, N_NORMAL_MEMORY) count += list_lru_count_node(lru, nid); return count; }


Glauber de Oliveira Costa3794.87%150.00%
Vladimir Davydov25.13%150.00%

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); typedef enum lru_status (*list_lru_walk_cb)(struct list_head *item, struct list_lru_one *list, spinlock_t *lock, void *cb_arg); /** * list_lru_walk_one: walk a list_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 resposible 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 list_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 list_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 value: 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); 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) { return list_lru_walk_one(lru, sc->nid, sc->memcg, isolate, cb_arg, &sc->nr_to_scan); }


Vladimir Davydov4695.83%266.67%
Glauber de Oliveira Costa24.17%133.33%

static inline unsigned long list_lru_walk(struct list_lru *lru, list_lru_walk_cb isolate, void *cb_arg, unsigned long nr_to_walk) { long isolated = 0; int nid; for_each_node_state(nid, N_NORMAL_MEMORY) { isolated += list_lru_walk_node(lru, nid, isolate, cb_arg, &nr_to_walk); if (nr_to_walk <= 0) break; } return isolated; }


Glauber de Oliveira Costa6293.94%133.33%
Vladimir Davydov46.06%266.67%

#endif /* _LRU_LIST_H */

Overall Contributors

Vladimir Davydov26046.26%650.00%
Dave Chinner14425.62%216.67%
Glauber de Oliveira Costa12021.35%216.67%
Johannes Weiner386.76%216.67%
Directory: include/linux
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