Commit | Line | Data |
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a38e4082 DC |
1 | /* |
2 | * Copyright (c) 2013 Red Hat, Inc. and Parallels Inc. All rights reserved. | |
3 | * Authors: David Chinner and Glauber Costa | |
4 | * | |
5 | * Generic LRU infrastructure | |
6 | */ | |
7 | #include <linux/kernel.h> | |
8 | #include <linux/module.h> | |
3b1d58a4 | 9 | #include <linux/mm.h> |
a38e4082 | 10 | #include <linux/list_lru.h> |
5ca302c8 | 11 | #include <linux/slab.h> |
a38e4082 DC |
12 | |
13 | bool list_lru_add(struct list_lru *lru, struct list_head *item) | |
14 | { | |
3b1d58a4 DC |
15 | int nid = page_to_nid(virt_to_page(item)); |
16 | struct list_lru_node *nlru = &lru->node[nid]; | |
17 | ||
18 | spin_lock(&nlru->lock); | |
19 | WARN_ON_ONCE(nlru->nr_items < 0); | |
a38e4082 | 20 | if (list_empty(item)) { |
3b1d58a4 DC |
21 | list_add_tail(item, &nlru->list); |
22 | if (nlru->nr_items++ == 0) | |
23 | node_set(nid, lru->active_nodes); | |
24 | spin_unlock(&nlru->lock); | |
a38e4082 DC |
25 | return true; |
26 | } | |
3b1d58a4 | 27 | spin_unlock(&nlru->lock); |
a38e4082 DC |
28 | return false; |
29 | } | |
30 | EXPORT_SYMBOL_GPL(list_lru_add); | |
31 | ||
32 | bool list_lru_del(struct list_lru *lru, struct list_head *item) | |
33 | { | |
3b1d58a4 DC |
34 | int nid = page_to_nid(virt_to_page(item)); |
35 | struct list_lru_node *nlru = &lru->node[nid]; | |
36 | ||
37 | spin_lock(&nlru->lock); | |
a38e4082 DC |
38 | if (!list_empty(item)) { |
39 | list_del_init(item); | |
3b1d58a4 DC |
40 | if (--nlru->nr_items == 0) |
41 | node_clear(nid, lru->active_nodes); | |
42 | WARN_ON_ONCE(nlru->nr_items < 0); | |
43 | spin_unlock(&nlru->lock); | |
a38e4082 DC |
44 | return true; |
45 | } | |
3b1d58a4 | 46 | spin_unlock(&nlru->lock); |
a38e4082 DC |
47 | return false; |
48 | } | |
49 | EXPORT_SYMBOL_GPL(list_lru_del); | |
50 | ||
6a4f496f GC |
51 | unsigned long |
52 | list_lru_count_node(struct list_lru *lru, int nid) | |
a38e4082 | 53 | { |
3b1d58a4 | 54 | unsigned long count = 0; |
6a4f496f | 55 | struct list_lru_node *nlru = &lru->node[nid]; |
3b1d58a4 | 56 | |
6a4f496f GC |
57 | spin_lock(&nlru->lock); |
58 | WARN_ON_ONCE(nlru->nr_items < 0); | |
59 | count += nlru->nr_items; | |
60 | spin_unlock(&nlru->lock); | |
3b1d58a4 DC |
61 | |
62 | return count; | |
63 | } | |
6a4f496f | 64 | EXPORT_SYMBOL_GPL(list_lru_count_node); |
3b1d58a4 | 65 | |
6a4f496f | 66 | unsigned long |
3b1d58a4 DC |
67 | list_lru_walk_node(struct list_lru *lru, int nid, list_lru_walk_cb isolate, |
68 | void *cb_arg, unsigned long *nr_to_walk) | |
69 | { | |
70 | ||
71 | struct list_lru_node *nlru = &lru->node[nid]; | |
a38e4082 | 72 | struct list_head *item, *n; |
3b1d58a4 | 73 | unsigned long isolated = 0; |
a38e4082 | 74 | |
3b1d58a4 | 75 | spin_lock(&nlru->lock); |
a38e4082 | 76 | restart: |
3b1d58a4 | 77 | list_for_each_safe(item, n, &nlru->list) { |
a38e4082 | 78 | enum lru_status ret; |
5cedf721 DC |
79 | |
80 | /* | |
81 | * decrement nr_to_walk first so that we don't livelock if we | |
82 | * get stuck on large numbesr of LRU_RETRY items | |
83 | */ | |
c56b097a | 84 | if (!*nr_to_walk) |
5cedf721 | 85 | break; |
c56b097a | 86 | --*nr_to_walk; |
5cedf721 | 87 | |
3b1d58a4 | 88 | ret = isolate(item, &nlru->lock, cb_arg); |
a38e4082 DC |
89 | switch (ret) { |
90 | case LRU_REMOVED: | |
3b1d58a4 DC |
91 | if (--nlru->nr_items == 0) |
92 | node_clear(nid, lru->active_nodes); | |
93 | WARN_ON_ONCE(nlru->nr_items < 0); | |
94 | isolated++; | |
a38e4082 DC |
95 | break; |
96 | case LRU_ROTATE: | |
3b1d58a4 | 97 | list_move_tail(item, &nlru->list); |
a38e4082 DC |
98 | break; |
99 | case LRU_SKIP: | |
100 | break; | |
101 | case LRU_RETRY: | |
5cedf721 DC |
102 | /* |
103 | * The lru lock has been dropped, our list traversal is | |
104 | * now invalid and so we have to restart from scratch. | |
105 | */ | |
a38e4082 DC |
106 | goto restart; |
107 | default: | |
108 | BUG(); | |
109 | } | |
a38e4082 | 110 | } |
3b1d58a4 DC |
111 | |
112 | spin_unlock(&nlru->lock); | |
113 | return isolated; | |
114 | } | |
115 | EXPORT_SYMBOL_GPL(list_lru_walk_node); | |
116 | ||
a38e4082 DC |
117 | int list_lru_init(struct list_lru *lru) |
118 | { | |
3b1d58a4 | 119 | int i; |
5ca302c8 GC |
120 | size_t size = sizeof(*lru->node) * nr_node_ids; |
121 | ||
122 | lru->node = kzalloc(size, GFP_KERNEL); | |
123 | if (!lru->node) | |
124 | return -ENOMEM; | |
a38e4082 | 125 | |
3b1d58a4 | 126 | nodes_clear(lru->active_nodes); |
5ca302c8 | 127 | for (i = 0; i < nr_node_ids; i++) { |
3b1d58a4 DC |
128 | spin_lock_init(&lru->node[i].lock); |
129 | INIT_LIST_HEAD(&lru->node[i].list); | |
130 | lru->node[i].nr_items = 0; | |
131 | } | |
a38e4082 DC |
132 | return 0; |
133 | } | |
134 | EXPORT_SYMBOL_GPL(list_lru_init); | |
5ca302c8 GC |
135 | |
136 | void list_lru_destroy(struct list_lru *lru) | |
137 | { | |
138 | kfree(lru->node); | |
139 | } | |
140 | EXPORT_SYMBOL_GPL(list_lru_destroy); |