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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright (c) 2013 Red Hat, Inc. and Parallels Inc. All rights reserved.
4 * Authors: David Chinner and Glauber Costa
5 *
6 * Generic LRU infrastructure
7 */
8#include <linux/kernel.h>
9#include <linux/module.h>
10#include <linux/mm.h>
11#include <linux/list_lru.h>
12#include <linux/slab.h>
13#include <linux/mutex.h>
14#include <linux/memcontrol.h>
15#include "slab.h"
16
17#ifdef CONFIG_MEMCG_KMEM
18static LIST_HEAD(list_lrus);
19static DEFINE_MUTEX(list_lrus_mutex);
20
21static void list_lru_register(struct list_lru *lru)
22{
23 mutex_lock(&list_lrus_mutex);
24 list_add(&lru->list, &list_lrus);
25 mutex_unlock(&list_lrus_mutex);
26}
27
28static void list_lru_unregister(struct list_lru *lru)
29{
30 mutex_lock(&list_lrus_mutex);
31 list_del(&lru->list);
32 mutex_unlock(&list_lrus_mutex);
33}
34
35static int lru_shrinker_id(struct list_lru *lru)
36{
37 return lru->shrinker_id;
38}
39
40static inline bool list_lru_memcg_aware(struct list_lru *lru)
41{
42 return lru->memcg_aware;
43}
44
45static inline struct list_lru_one *
46list_lru_from_memcg_idx(struct list_lru_node *nlru, int idx)
47{
48 struct list_lru_memcg *memcg_lrus;
49 /*
50 * Either lock or RCU protects the array of per cgroup lists
51 * from relocation (see memcg_update_list_lru_node).
52 */
53 memcg_lrus = rcu_dereference_check(nlru->memcg_lrus,
54 lockdep_is_held(&nlru->lock));
55 if (memcg_lrus && idx >= 0)
56 return memcg_lrus->lru[idx];
57 return &nlru->lru;
58}
59
60static __always_inline struct mem_cgroup *mem_cgroup_from_kmem(void *ptr)
61{
62 struct page *page;
63
64 if (!memcg_kmem_enabled())
65 return NULL;
66 page = virt_to_head_page(ptr);
67 return memcg_from_slab_page(page);
68}
69
70static inline struct list_lru_one *
71list_lru_from_kmem(struct list_lru_node *nlru, void *ptr,
72 struct mem_cgroup **memcg_ptr)
73{
74 struct list_lru_one *l = &nlru->lru;
75 struct mem_cgroup *memcg = NULL;
76
77 if (!nlru->memcg_lrus)
78 goto out;
79
80 memcg = mem_cgroup_from_kmem(ptr);
81 if (!memcg)
82 goto out;
83
84 l = list_lru_from_memcg_idx(nlru, memcg_cache_id(memcg));
85out:
86 if (memcg_ptr)
87 *memcg_ptr = memcg;
88 return l;
89}
90#else
91static void list_lru_register(struct list_lru *lru)
92{
93}
94
95static void list_lru_unregister(struct list_lru *lru)
96{
97}
98
99static int lru_shrinker_id(struct list_lru *lru)
100{
101 return -1;
102}
103
104static inline bool list_lru_memcg_aware(struct list_lru *lru)
105{
106 return false;
107}
108
109static inline struct list_lru_one *
110list_lru_from_memcg_idx(struct list_lru_node *nlru, int idx)
111{
112 return &nlru->lru;
113}
114
115static inline struct list_lru_one *
116list_lru_from_kmem(struct list_lru_node *nlru, void *ptr,
117 struct mem_cgroup **memcg_ptr)
118{
119 if (memcg_ptr)
120 *memcg_ptr = NULL;
121 return &nlru->lru;
122}
123#endif /* CONFIG_MEMCG_KMEM */
124
125bool list_lru_add(struct list_lru *lru, struct list_head *item)
126{
127 int nid = page_to_nid(virt_to_page(item));
128 struct list_lru_node *nlru = &lru->node[nid];
129 struct mem_cgroup *memcg;
130 struct list_lru_one *l;
131
132 spin_lock(&nlru->lock);
133 if (list_empty(item)) {
134 l = list_lru_from_kmem(nlru, item, &memcg);
135 list_add_tail(item, &l->list);
136 /* Set shrinker bit if the first element was added */
137 if (!l->nr_items++)
138 memcg_set_shrinker_bit(memcg, nid,
139 lru_shrinker_id(lru));
140 nlru->nr_items++;
141 spin_unlock(&nlru->lock);
142 return true;
143 }
144 spin_unlock(&nlru->lock);
145 return false;
146}
147EXPORT_SYMBOL_GPL(list_lru_add);
148
149bool list_lru_del(struct list_lru *lru, struct list_head *item)
150{
151 int nid = page_to_nid(virt_to_page(item));
152 struct list_lru_node *nlru = &lru->node[nid];
153 struct list_lru_one *l;
154
155 spin_lock(&nlru->lock);
156 if (!list_empty(item)) {
157 l = list_lru_from_kmem(nlru, item, NULL);
158 list_del_init(item);
159 l->nr_items--;
160 nlru->nr_items--;
161 spin_unlock(&nlru->lock);
162 return true;
163 }
164 spin_unlock(&nlru->lock);
165 return false;
166}
167EXPORT_SYMBOL_GPL(list_lru_del);
168
169void list_lru_isolate(struct list_lru_one *list, struct list_head *item)
170{
171 list_del_init(item);
172 list->nr_items--;
173}
174EXPORT_SYMBOL_GPL(list_lru_isolate);
175
176void list_lru_isolate_move(struct list_lru_one *list, struct list_head *item,
177 struct list_head *head)
178{
179 list_move(item, head);
180 list->nr_items--;
181}
182EXPORT_SYMBOL_GPL(list_lru_isolate_move);
183
184unsigned long list_lru_count_one(struct list_lru *lru,
185 int nid, struct mem_cgroup *memcg)
186{
187 struct list_lru_node *nlru = &lru->node[nid];
188 struct list_lru_one *l;
189 unsigned long count;
190
191 rcu_read_lock();
192 l = list_lru_from_memcg_idx(nlru, memcg_cache_id(memcg));
193 count = l->nr_items;
194 rcu_read_unlock();
195
196 return count;
197}
198EXPORT_SYMBOL_GPL(list_lru_count_one);
199
200unsigned long list_lru_count_node(struct list_lru *lru, int nid)
201{
202 struct list_lru_node *nlru;
203
204 nlru = &lru->node[nid];
205 return nlru->nr_items;
206}
207EXPORT_SYMBOL_GPL(list_lru_count_node);
208
209static unsigned long
210__list_lru_walk_one(struct list_lru_node *nlru, int memcg_idx,
211 list_lru_walk_cb isolate, void *cb_arg,
212 unsigned long *nr_to_walk)
213{
214
215 struct list_lru_one *l;
216 struct list_head *item, *n;
217 unsigned long isolated = 0;
218
219 l = list_lru_from_memcg_idx(nlru, memcg_idx);
220restart:
221 list_for_each_safe(item, n, &l->list) {
222 enum lru_status ret;
223
224 /*
225 * decrement nr_to_walk first so that we don't livelock if we
226 * get stuck on large numbesr of LRU_RETRY items
227 */
228 if (!*nr_to_walk)
229 break;
230 --*nr_to_walk;
231
232 ret = isolate(item, l, &nlru->lock, cb_arg);
233 switch (ret) {
234 case LRU_REMOVED_RETRY:
235 assert_spin_locked(&nlru->lock);
236 /* fall through */
237 case LRU_REMOVED:
238 isolated++;
239 nlru->nr_items--;
240 /*
241 * If the lru lock has been dropped, our list
242 * traversal is now invalid and so we have to
243 * restart from scratch.
244 */
245 if (ret == LRU_REMOVED_RETRY)
246 goto restart;
247 break;
248 case LRU_ROTATE:
249 list_move_tail(item, &l->list);
250 break;
251 case LRU_SKIP:
252 break;
253 case LRU_RETRY:
254 /*
255 * The lru lock has been dropped, our list traversal is
256 * now invalid and so we have to restart from scratch.
257 */
258 assert_spin_locked(&nlru->lock);
259 goto restart;
260 default:
261 BUG();
262 }
263 }
264 return isolated;
265}
266
267unsigned long
268list_lru_walk_one(struct list_lru *lru, int nid, struct mem_cgroup *memcg,
269 list_lru_walk_cb isolate, void *cb_arg,
270 unsigned long *nr_to_walk)
271{
272 struct list_lru_node *nlru = &lru->node[nid];
273 unsigned long ret;
274
275 spin_lock(&nlru->lock);
276 ret = __list_lru_walk_one(nlru, memcg_cache_id(memcg), isolate, cb_arg,
277 nr_to_walk);
278 spin_unlock(&nlru->lock);
279 return ret;
280}
281EXPORT_SYMBOL_GPL(list_lru_walk_one);
282
283unsigned long
284list_lru_walk_one_irq(struct list_lru *lru, int nid, struct mem_cgroup *memcg,
285 list_lru_walk_cb isolate, void *cb_arg,
286 unsigned long *nr_to_walk)
287{
288 struct list_lru_node *nlru = &lru->node[nid];
289 unsigned long ret;
290
291 spin_lock_irq(&nlru->lock);
292 ret = __list_lru_walk_one(nlru, memcg_cache_id(memcg), isolate, cb_arg,
293 nr_to_walk);
294 spin_unlock_irq(&nlru->lock);
295 return ret;
296}
297
298unsigned long list_lru_walk_node(struct list_lru *lru, int nid,
299 list_lru_walk_cb isolate, void *cb_arg,
300 unsigned long *nr_to_walk)
301{
302 long isolated = 0;
303 int memcg_idx;
304
305 isolated += list_lru_walk_one(lru, nid, NULL, isolate, cb_arg,
306 nr_to_walk);
307 if (*nr_to_walk > 0 && list_lru_memcg_aware(lru)) {
308 for_each_memcg_cache_index(memcg_idx) {
309 struct list_lru_node *nlru = &lru->node[nid];
310
311 spin_lock(&nlru->lock);
312 isolated += __list_lru_walk_one(nlru, memcg_idx,
313 isolate, cb_arg,
314 nr_to_walk);
315 spin_unlock(&nlru->lock);
316
317 if (*nr_to_walk <= 0)
318 break;
319 }
320 }
321 return isolated;
322}
323EXPORT_SYMBOL_GPL(list_lru_walk_node);
324
325static void init_one_lru(struct list_lru_one *l)
326{
327 INIT_LIST_HEAD(&l->list);
328 l->nr_items = 0;
329}
330
331#ifdef CONFIG_MEMCG_KMEM
332static void __memcg_destroy_list_lru_node(struct list_lru_memcg *memcg_lrus,
333 int begin, int end)
334{
335 int i;
336
337 for (i = begin; i < end; i++)
338 kfree(memcg_lrus->lru[i]);
339}
340
341static int __memcg_init_list_lru_node(struct list_lru_memcg *memcg_lrus,
342 int begin, int end)
343{
344 int i;
345
346 for (i = begin; i < end; i++) {
347 struct list_lru_one *l;
348
349 l = kmalloc(sizeof(struct list_lru_one), GFP_KERNEL);
350 if (!l)
351 goto fail;
352
353 init_one_lru(l);
354 memcg_lrus->lru[i] = l;
355 }
356 return 0;
357fail:
358 __memcg_destroy_list_lru_node(memcg_lrus, begin, i);
359 return -ENOMEM;
360}
361
362static int memcg_init_list_lru_node(struct list_lru_node *nlru)
363{
364 struct list_lru_memcg *memcg_lrus;
365 int size = memcg_nr_cache_ids;
366
367 memcg_lrus = kvmalloc(sizeof(*memcg_lrus) +
368 size * sizeof(void *), GFP_KERNEL);
369 if (!memcg_lrus)
370 return -ENOMEM;
371
372 if (__memcg_init_list_lru_node(memcg_lrus, 0, size)) {
373 kvfree(memcg_lrus);
374 return -ENOMEM;
375 }
376 RCU_INIT_POINTER(nlru->memcg_lrus, memcg_lrus);
377
378 return 0;
379}
380
381static void memcg_destroy_list_lru_node(struct list_lru_node *nlru)
382{
383 struct list_lru_memcg *memcg_lrus;
384 /*
385 * This is called when shrinker has already been unregistered,
386 * and nobody can use it. So, there is no need to use kvfree_rcu().
387 */
388 memcg_lrus = rcu_dereference_protected(nlru->memcg_lrus, true);
389 __memcg_destroy_list_lru_node(memcg_lrus, 0, memcg_nr_cache_ids);
390 kvfree(memcg_lrus);
391}
392
393static void kvfree_rcu(struct rcu_head *head)
394{
395 struct list_lru_memcg *mlru;
396
397 mlru = container_of(head, struct list_lru_memcg, rcu);
398 kvfree(mlru);
399}
400
401static int memcg_update_list_lru_node(struct list_lru_node *nlru,
402 int old_size, int new_size)
403{
404 struct list_lru_memcg *old, *new;
405
406 BUG_ON(old_size > new_size);
407
408 old = rcu_dereference_protected(nlru->memcg_lrus,
409 lockdep_is_held(&list_lrus_mutex));
410 new = kvmalloc(sizeof(*new) + new_size * sizeof(void *), GFP_KERNEL);
411 if (!new)
412 return -ENOMEM;
413
414 if (__memcg_init_list_lru_node(new, old_size, new_size)) {
415 kvfree(new);
416 return -ENOMEM;
417 }
418
419 memcpy(&new->lru, &old->lru, old_size * sizeof(void *));
420
421 /*
422 * The locking below allows readers that hold nlru->lock avoid taking
423 * rcu_read_lock (see list_lru_from_memcg_idx).
424 *
425 * Since list_lru_{add,del} may be called under an IRQ-safe lock,
426 * we have to use IRQ-safe primitives here to avoid deadlock.
427 */
428 spin_lock_irq(&nlru->lock);
429 rcu_assign_pointer(nlru->memcg_lrus, new);
430 spin_unlock_irq(&nlru->lock);
431
432 call_rcu(&old->rcu, kvfree_rcu);
433 return 0;
434}
435
436static void memcg_cancel_update_list_lru_node(struct list_lru_node *nlru,
437 int old_size, int new_size)
438{
439 struct list_lru_memcg *memcg_lrus;
440
441 memcg_lrus = rcu_dereference_protected(nlru->memcg_lrus,
442 lockdep_is_held(&list_lrus_mutex));
443 /* do not bother shrinking the array back to the old size, because we
444 * cannot handle allocation failures here */
445 __memcg_destroy_list_lru_node(memcg_lrus, old_size, new_size);
446}
447
448static int memcg_init_list_lru(struct list_lru *lru, bool memcg_aware)
449{
450 int i;
451
452 lru->memcg_aware = memcg_aware;
453
454 if (!memcg_aware)
455 return 0;
456
457 for_each_node(i) {
458 if (memcg_init_list_lru_node(&lru->node[i]))
459 goto fail;
460 }
461 return 0;
462fail:
463 for (i = i - 1; i >= 0; i--) {
464 if (!lru->node[i].memcg_lrus)
465 continue;
466 memcg_destroy_list_lru_node(&lru->node[i]);
467 }
468 return -ENOMEM;
469}
470
471static void memcg_destroy_list_lru(struct list_lru *lru)
472{
473 int i;
474
475 if (!list_lru_memcg_aware(lru))
476 return;
477
478 for_each_node(i)
479 memcg_destroy_list_lru_node(&lru->node[i]);
480}
481
482static int memcg_update_list_lru(struct list_lru *lru,
483 int old_size, int new_size)
484{
485 int i;
486
487 if (!list_lru_memcg_aware(lru))
488 return 0;
489
490 for_each_node(i) {
491 if (memcg_update_list_lru_node(&lru->node[i],
492 old_size, new_size))
493 goto fail;
494 }
495 return 0;
496fail:
497 for (i = i - 1; i >= 0; i--) {
498 if (!lru->node[i].memcg_lrus)
499 continue;
500
501 memcg_cancel_update_list_lru_node(&lru->node[i],
502 old_size, new_size);
503 }
504 return -ENOMEM;
505}
506
507static void memcg_cancel_update_list_lru(struct list_lru *lru,
508 int old_size, int new_size)
509{
510 int i;
511
512 if (!list_lru_memcg_aware(lru))
513 return;
514
515 for_each_node(i)
516 memcg_cancel_update_list_lru_node(&lru->node[i],
517 old_size, new_size);
518}
519
520int memcg_update_all_list_lrus(int new_size)
521{
522 int ret = 0;
523 struct list_lru *lru;
524 int old_size = memcg_nr_cache_ids;
525
526 mutex_lock(&list_lrus_mutex);
527 list_for_each_entry(lru, &list_lrus, list) {
528 ret = memcg_update_list_lru(lru, old_size, new_size);
529 if (ret)
530 goto fail;
531 }
532out:
533 mutex_unlock(&list_lrus_mutex);
534 return ret;
535fail:
536 list_for_each_entry_continue_reverse(lru, &list_lrus, list)
537 memcg_cancel_update_list_lru(lru, old_size, new_size);
538 goto out;
539}
540
541static void memcg_drain_list_lru_node(struct list_lru *lru, int nid,
542 int src_idx, struct mem_cgroup *dst_memcg)
543{
544 struct list_lru_node *nlru = &lru->node[nid];
545 int dst_idx = dst_memcg->kmemcg_id;
546 struct list_lru_one *src, *dst;
547 bool set;
548
549 /*
550 * Since list_lru_{add,del} may be called under an IRQ-safe lock,
551 * we have to use IRQ-safe primitives here to avoid deadlock.
552 */
553 spin_lock_irq(&nlru->lock);
554
555 src = list_lru_from_memcg_idx(nlru, src_idx);
556 dst = list_lru_from_memcg_idx(nlru, dst_idx);
557
558 list_splice_init(&src->list, &dst->list);
559 set = (!dst->nr_items && src->nr_items);
560 dst->nr_items += src->nr_items;
561 if (set)
562 memcg_set_shrinker_bit(dst_memcg, nid, lru_shrinker_id(lru));
563 src->nr_items = 0;
564
565 spin_unlock_irq(&nlru->lock);
566}
567
568static void memcg_drain_list_lru(struct list_lru *lru,
569 int src_idx, struct mem_cgroup *dst_memcg)
570{
571 int i;
572
573 if (!list_lru_memcg_aware(lru))
574 return;
575
576 for_each_node(i)
577 memcg_drain_list_lru_node(lru, i, src_idx, dst_memcg);
578}
579
580void memcg_drain_all_list_lrus(int src_idx, struct mem_cgroup *dst_memcg)
581{
582 struct list_lru *lru;
583
584 mutex_lock(&list_lrus_mutex);
585 list_for_each_entry(lru, &list_lrus, list)
586 memcg_drain_list_lru(lru, src_idx, dst_memcg);
587 mutex_unlock(&list_lrus_mutex);
588}
589#else
590static int memcg_init_list_lru(struct list_lru *lru, bool memcg_aware)
591{
592 return 0;
593}
594
595static void memcg_destroy_list_lru(struct list_lru *lru)
596{
597}
598#endif /* CONFIG_MEMCG_KMEM */
599
600int __list_lru_init(struct list_lru *lru, bool memcg_aware,
601 struct lock_class_key *key, struct shrinker *shrinker)
602{
603 int i;
604 int err = -ENOMEM;
605
606#ifdef CONFIG_MEMCG_KMEM
607 if (shrinker)
608 lru->shrinker_id = shrinker->id;
609 else
610 lru->shrinker_id = -1;
611#endif
612 memcg_get_cache_ids();
613
614 lru->node = kcalloc(nr_node_ids, sizeof(*lru->node), GFP_KERNEL);
615 if (!lru->node)
616 goto out;
617
618 for_each_node(i) {
619 spin_lock_init(&lru->node[i].lock);
620 if (key)
621 lockdep_set_class(&lru->node[i].lock, key);
622 init_one_lru(&lru->node[i].lru);
623 }
624
625 err = memcg_init_list_lru(lru, memcg_aware);
626 if (err) {
627 kfree(lru->node);
628 /* Do this so a list_lru_destroy() doesn't crash: */
629 lru->node = NULL;
630 goto out;
631 }
632
633 list_lru_register(lru);
634out:
635 memcg_put_cache_ids();
636 return err;
637}
638EXPORT_SYMBOL_GPL(__list_lru_init);
639
640void list_lru_destroy(struct list_lru *lru)
641{
642 /* Already destroyed or not yet initialized? */
643 if (!lru->node)
644 return;
645
646 memcg_get_cache_ids();
647
648 list_lru_unregister(lru);
649
650 memcg_destroy_list_lru(lru);
651 kfree(lru->node);
652 lru->node = NULL;
653
654#ifdef CONFIG_MEMCG_KMEM
655 lru->shrinker_id = -1;
656#endif
657 memcg_put_cache_ids();
658}
659EXPORT_SYMBOL_GPL(list_lru_destroy);
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>
9#include <linux/mm.h>
10#include <linux/list_lru.h>
11#include <linux/slab.h>
12#include <linux/mutex.h>
13#include <linux/memcontrol.h>
14
15#if defined(CONFIG_MEMCG) && !defined(CONFIG_SLOB)
16static LIST_HEAD(list_lrus);
17static DEFINE_MUTEX(list_lrus_mutex);
18
19static void list_lru_register(struct list_lru *lru)
20{
21 mutex_lock(&list_lrus_mutex);
22 list_add(&lru->list, &list_lrus);
23 mutex_unlock(&list_lrus_mutex);
24}
25
26static void list_lru_unregister(struct list_lru *lru)
27{
28 mutex_lock(&list_lrus_mutex);
29 list_del(&lru->list);
30 mutex_unlock(&list_lrus_mutex);
31}
32#else
33static void list_lru_register(struct list_lru *lru)
34{
35}
36
37static void list_lru_unregister(struct list_lru *lru)
38{
39}
40#endif /* CONFIG_MEMCG && !CONFIG_SLOB */
41
42#if defined(CONFIG_MEMCG) && !defined(CONFIG_SLOB)
43static inline bool list_lru_memcg_aware(struct list_lru *lru)
44{
45 /*
46 * This needs node 0 to be always present, even
47 * in the systems supporting sparse numa ids.
48 */
49 return !!lru->node[0].memcg_lrus;
50}
51
52static inline struct list_lru_one *
53list_lru_from_memcg_idx(struct list_lru_node *nlru, int idx)
54{
55 /*
56 * The lock protects the array of per cgroup lists from relocation
57 * (see memcg_update_list_lru_node).
58 */
59 lockdep_assert_held(&nlru->lock);
60 if (nlru->memcg_lrus && idx >= 0)
61 return nlru->memcg_lrus->lru[idx];
62
63 return &nlru->lru;
64}
65
66static __always_inline struct mem_cgroup *mem_cgroup_from_kmem(void *ptr)
67{
68 struct page *page;
69
70 if (!memcg_kmem_enabled())
71 return NULL;
72 page = virt_to_head_page(ptr);
73 return page->mem_cgroup;
74}
75
76static inline struct list_lru_one *
77list_lru_from_kmem(struct list_lru_node *nlru, void *ptr)
78{
79 struct mem_cgroup *memcg;
80
81 if (!nlru->memcg_lrus)
82 return &nlru->lru;
83
84 memcg = mem_cgroup_from_kmem(ptr);
85 if (!memcg)
86 return &nlru->lru;
87
88 return list_lru_from_memcg_idx(nlru, memcg_cache_id(memcg));
89}
90#else
91static inline bool list_lru_memcg_aware(struct list_lru *lru)
92{
93 return false;
94}
95
96static inline struct list_lru_one *
97list_lru_from_memcg_idx(struct list_lru_node *nlru, int idx)
98{
99 return &nlru->lru;
100}
101
102static inline struct list_lru_one *
103list_lru_from_kmem(struct list_lru_node *nlru, void *ptr)
104{
105 return &nlru->lru;
106}
107#endif /* CONFIG_MEMCG && !CONFIG_SLOB */
108
109bool list_lru_add(struct list_lru *lru, struct list_head *item)
110{
111 int nid = page_to_nid(virt_to_page(item));
112 struct list_lru_node *nlru = &lru->node[nid];
113 struct list_lru_one *l;
114
115 spin_lock(&nlru->lock);
116 if (list_empty(item)) {
117 l = list_lru_from_kmem(nlru, item);
118 list_add_tail(item, &l->list);
119 l->nr_items++;
120 spin_unlock(&nlru->lock);
121 return true;
122 }
123 spin_unlock(&nlru->lock);
124 return false;
125}
126EXPORT_SYMBOL_GPL(list_lru_add);
127
128bool list_lru_del(struct list_lru *lru, struct list_head *item)
129{
130 int nid = page_to_nid(virt_to_page(item));
131 struct list_lru_node *nlru = &lru->node[nid];
132 struct list_lru_one *l;
133
134 spin_lock(&nlru->lock);
135 if (!list_empty(item)) {
136 l = list_lru_from_kmem(nlru, item);
137 list_del_init(item);
138 l->nr_items--;
139 spin_unlock(&nlru->lock);
140 return true;
141 }
142 spin_unlock(&nlru->lock);
143 return false;
144}
145EXPORT_SYMBOL_GPL(list_lru_del);
146
147void list_lru_isolate(struct list_lru_one *list, struct list_head *item)
148{
149 list_del_init(item);
150 list->nr_items--;
151}
152EXPORT_SYMBOL_GPL(list_lru_isolate);
153
154void list_lru_isolate_move(struct list_lru_one *list, struct list_head *item,
155 struct list_head *head)
156{
157 list_move(item, head);
158 list->nr_items--;
159}
160EXPORT_SYMBOL_GPL(list_lru_isolate_move);
161
162static unsigned long __list_lru_count_one(struct list_lru *lru,
163 int nid, int memcg_idx)
164{
165 struct list_lru_node *nlru = &lru->node[nid];
166 struct list_lru_one *l;
167 unsigned long count;
168
169 spin_lock(&nlru->lock);
170 l = list_lru_from_memcg_idx(nlru, memcg_idx);
171 count = l->nr_items;
172 spin_unlock(&nlru->lock);
173
174 return count;
175}
176
177unsigned long list_lru_count_one(struct list_lru *lru,
178 int nid, struct mem_cgroup *memcg)
179{
180 return __list_lru_count_one(lru, nid, memcg_cache_id(memcg));
181}
182EXPORT_SYMBOL_GPL(list_lru_count_one);
183
184unsigned long list_lru_count_node(struct list_lru *lru, int nid)
185{
186 long count = 0;
187 int memcg_idx;
188
189 count += __list_lru_count_one(lru, nid, -1);
190 if (list_lru_memcg_aware(lru)) {
191 for_each_memcg_cache_index(memcg_idx)
192 count += __list_lru_count_one(lru, nid, memcg_idx);
193 }
194 return count;
195}
196EXPORT_SYMBOL_GPL(list_lru_count_node);
197
198static unsigned long
199__list_lru_walk_one(struct list_lru *lru, int nid, int memcg_idx,
200 list_lru_walk_cb isolate, void *cb_arg,
201 unsigned long *nr_to_walk)
202{
203
204 struct list_lru_node *nlru = &lru->node[nid];
205 struct list_lru_one *l;
206 struct list_head *item, *n;
207 unsigned long isolated = 0;
208
209 spin_lock(&nlru->lock);
210 l = list_lru_from_memcg_idx(nlru, memcg_idx);
211restart:
212 list_for_each_safe(item, n, &l->list) {
213 enum lru_status ret;
214
215 /*
216 * decrement nr_to_walk first so that we don't livelock if we
217 * get stuck on large numbesr of LRU_RETRY items
218 */
219 if (!*nr_to_walk)
220 break;
221 --*nr_to_walk;
222
223 ret = isolate(item, l, &nlru->lock, cb_arg);
224 switch (ret) {
225 case LRU_REMOVED_RETRY:
226 assert_spin_locked(&nlru->lock);
227 case LRU_REMOVED:
228 isolated++;
229 /*
230 * If the lru lock has been dropped, our list
231 * traversal is now invalid and so we have to
232 * restart from scratch.
233 */
234 if (ret == LRU_REMOVED_RETRY)
235 goto restart;
236 break;
237 case LRU_ROTATE:
238 list_move_tail(item, &l->list);
239 break;
240 case LRU_SKIP:
241 break;
242 case LRU_RETRY:
243 /*
244 * The lru lock has been dropped, our list traversal is
245 * now invalid and so we have to restart from scratch.
246 */
247 assert_spin_locked(&nlru->lock);
248 goto restart;
249 default:
250 BUG();
251 }
252 }
253
254 spin_unlock(&nlru->lock);
255 return isolated;
256}
257
258unsigned long
259list_lru_walk_one(struct list_lru *lru, int nid, struct mem_cgroup *memcg,
260 list_lru_walk_cb isolate, void *cb_arg,
261 unsigned long *nr_to_walk)
262{
263 return __list_lru_walk_one(lru, nid, memcg_cache_id(memcg),
264 isolate, cb_arg, nr_to_walk);
265}
266EXPORT_SYMBOL_GPL(list_lru_walk_one);
267
268unsigned long list_lru_walk_node(struct list_lru *lru, int nid,
269 list_lru_walk_cb isolate, void *cb_arg,
270 unsigned long *nr_to_walk)
271{
272 long isolated = 0;
273 int memcg_idx;
274
275 isolated += __list_lru_walk_one(lru, nid, -1, isolate, cb_arg,
276 nr_to_walk);
277 if (*nr_to_walk > 0 && list_lru_memcg_aware(lru)) {
278 for_each_memcg_cache_index(memcg_idx) {
279 isolated += __list_lru_walk_one(lru, nid, memcg_idx,
280 isolate, cb_arg, nr_to_walk);
281 if (*nr_to_walk <= 0)
282 break;
283 }
284 }
285 return isolated;
286}
287EXPORT_SYMBOL_GPL(list_lru_walk_node);
288
289static void init_one_lru(struct list_lru_one *l)
290{
291 INIT_LIST_HEAD(&l->list);
292 l->nr_items = 0;
293}
294
295#if defined(CONFIG_MEMCG) && !defined(CONFIG_SLOB)
296static void __memcg_destroy_list_lru_node(struct list_lru_memcg *memcg_lrus,
297 int begin, int end)
298{
299 int i;
300
301 for (i = begin; i < end; i++)
302 kfree(memcg_lrus->lru[i]);
303}
304
305static int __memcg_init_list_lru_node(struct list_lru_memcg *memcg_lrus,
306 int begin, int end)
307{
308 int i;
309
310 for (i = begin; i < end; i++) {
311 struct list_lru_one *l;
312
313 l = kmalloc(sizeof(struct list_lru_one), GFP_KERNEL);
314 if (!l)
315 goto fail;
316
317 init_one_lru(l);
318 memcg_lrus->lru[i] = l;
319 }
320 return 0;
321fail:
322 __memcg_destroy_list_lru_node(memcg_lrus, begin, i - 1);
323 return -ENOMEM;
324}
325
326static int memcg_init_list_lru_node(struct list_lru_node *nlru)
327{
328 int size = memcg_nr_cache_ids;
329
330 nlru->memcg_lrus = kmalloc(size * sizeof(void *), GFP_KERNEL);
331 if (!nlru->memcg_lrus)
332 return -ENOMEM;
333
334 if (__memcg_init_list_lru_node(nlru->memcg_lrus, 0, size)) {
335 kfree(nlru->memcg_lrus);
336 return -ENOMEM;
337 }
338
339 return 0;
340}
341
342static void memcg_destroy_list_lru_node(struct list_lru_node *nlru)
343{
344 __memcg_destroy_list_lru_node(nlru->memcg_lrus, 0, memcg_nr_cache_ids);
345 kfree(nlru->memcg_lrus);
346}
347
348static int memcg_update_list_lru_node(struct list_lru_node *nlru,
349 int old_size, int new_size)
350{
351 struct list_lru_memcg *old, *new;
352
353 BUG_ON(old_size > new_size);
354
355 old = nlru->memcg_lrus;
356 new = kmalloc(new_size * sizeof(void *), GFP_KERNEL);
357 if (!new)
358 return -ENOMEM;
359
360 if (__memcg_init_list_lru_node(new, old_size, new_size)) {
361 kfree(new);
362 return -ENOMEM;
363 }
364
365 memcpy(new, old, old_size * sizeof(void *));
366
367 /*
368 * The lock guarantees that we won't race with a reader
369 * (see list_lru_from_memcg_idx).
370 *
371 * Since list_lru_{add,del} may be called under an IRQ-safe lock,
372 * we have to use IRQ-safe primitives here to avoid deadlock.
373 */
374 spin_lock_irq(&nlru->lock);
375 nlru->memcg_lrus = new;
376 spin_unlock_irq(&nlru->lock);
377
378 kfree(old);
379 return 0;
380}
381
382static void memcg_cancel_update_list_lru_node(struct list_lru_node *nlru,
383 int old_size, int new_size)
384{
385 /* do not bother shrinking the array back to the old size, because we
386 * cannot handle allocation failures here */
387 __memcg_destroy_list_lru_node(nlru->memcg_lrus, old_size, new_size);
388}
389
390static int memcg_init_list_lru(struct list_lru *lru, bool memcg_aware)
391{
392 int i;
393
394 if (!memcg_aware)
395 return 0;
396
397 for_each_node(i) {
398 if (memcg_init_list_lru_node(&lru->node[i]))
399 goto fail;
400 }
401 return 0;
402fail:
403 for (i = i - 1; i >= 0; i--) {
404 if (!lru->node[i].memcg_lrus)
405 continue;
406 memcg_destroy_list_lru_node(&lru->node[i]);
407 }
408 return -ENOMEM;
409}
410
411static void memcg_destroy_list_lru(struct list_lru *lru)
412{
413 int i;
414
415 if (!list_lru_memcg_aware(lru))
416 return;
417
418 for_each_node(i)
419 memcg_destroy_list_lru_node(&lru->node[i]);
420}
421
422static int memcg_update_list_lru(struct list_lru *lru,
423 int old_size, int new_size)
424{
425 int i;
426
427 if (!list_lru_memcg_aware(lru))
428 return 0;
429
430 for_each_node(i) {
431 if (memcg_update_list_lru_node(&lru->node[i],
432 old_size, new_size))
433 goto fail;
434 }
435 return 0;
436fail:
437 for (i = i - 1; i >= 0; i--) {
438 if (!lru->node[i].memcg_lrus)
439 continue;
440
441 memcg_cancel_update_list_lru_node(&lru->node[i],
442 old_size, new_size);
443 }
444 return -ENOMEM;
445}
446
447static void memcg_cancel_update_list_lru(struct list_lru *lru,
448 int old_size, int new_size)
449{
450 int i;
451
452 if (!list_lru_memcg_aware(lru))
453 return;
454
455 for_each_node(i)
456 memcg_cancel_update_list_lru_node(&lru->node[i],
457 old_size, new_size);
458}
459
460int memcg_update_all_list_lrus(int new_size)
461{
462 int ret = 0;
463 struct list_lru *lru;
464 int old_size = memcg_nr_cache_ids;
465
466 mutex_lock(&list_lrus_mutex);
467 list_for_each_entry(lru, &list_lrus, list) {
468 ret = memcg_update_list_lru(lru, old_size, new_size);
469 if (ret)
470 goto fail;
471 }
472out:
473 mutex_unlock(&list_lrus_mutex);
474 return ret;
475fail:
476 list_for_each_entry_continue_reverse(lru, &list_lrus, list)
477 memcg_cancel_update_list_lru(lru, old_size, new_size);
478 goto out;
479}
480
481static void memcg_drain_list_lru_node(struct list_lru_node *nlru,
482 int src_idx, int dst_idx)
483{
484 struct list_lru_one *src, *dst;
485
486 /*
487 * Since list_lru_{add,del} may be called under an IRQ-safe lock,
488 * we have to use IRQ-safe primitives here to avoid deadlock.
489 */
490 spin_lock_irq(&nlru->lock);
491
492 src = list_lru_from_memcg_idx(nlru, src_idx);
493 dst = list_lru_from_memcg_idx(nlru, dst_idx);
494
495 list_splice_init(&src->list, &dst->list);
496 dst->nr_items += src->nr_items;
497 src->nr_items = 0;
498
499 spin_unlock_irq(&nlru->lock);
500}
501
502static void memcg_drain_list_lru(struct list_lru *lru,
503 int src_idx, int dst_idx)
504{
505 int i;
506
507 if (!list_lru_memcg_aware(lru))
508 return;
509
510 for_each_node(i)
511 memcg_drain_list_lru_node(&lru->node[i], src_idx, dst_idx);
512}
513
514void memcg_drain_all_list_lrus(int src_idx, int dst_idx)
515{
516 struct list_lru *lru;
517
518 mutex_lock(&list_lrus_mutex);
519 list_for_each_entry(lru, &list_lrus, list)
520 memcg_drain_list_lru(lru, src_idx, dst_idx);
521 mutex_unlock(&list_lrus_mutex);
522}
523#else
524static int memcg_init_list_lru(struct list_lru *lru, bool memcg_aware)
525{
526 return 0;
527}
528
529static void memcg_destroy_list_lru(struct list_lru *lru)
530{
531}
532#endif /* CONFIG_MEMCG && !CONFIG_SLOB */
533
534int __list_lru_init(struct list_lru *lru, bool memcg_aware,
535 struct lock_class_key *key)
536{
537 int i;
538 size_t size = sizeof(*lru->node) * nr_node_ids;
539 int err = -ENOMEM;
540
541 memcg_get_cache_ids();
542
543 lru->node = kzalloc(size, GFP_KERNEL);
544 if (!lru->node)
545 goto out;
546
547 for_each_node(i) {
548 spin_lock_init(&lru->node[i].lock);
549 if (key)
550 lockdep_set_class(&lru->node[i].lock, key);
551 init_one_lru(&lru->node[i].lru);
552 }
553
554 err = memcg_init_list_lru(lru, memcg_aware);
555 if (err) {
556 kfree(lru->node);
557 /* Do this so a list_lru_destroy() doesn't crash: */
558 lru->node = NULL;
559 goto out;
560 }
561
562 list_lru_register(lru);
563out:
564 memcg_put_cache_ids();
565 return err;
566}
567EXPORT_SYMBOL_GPL(__list_lru_init);
568
569void list_lru_destroy(struct list_lru *lru)
570{
571 /* Already destroyed or not yet initialized? */
572 if (!lru->node)
573 return;
574
575 memcg_get_cache_ids();
576
577 list_lru_unregister(lru);
578
579 memcg_destroy_list_lru(lru);
580 kfree(lru->node);
581 lru->node = NULL;
582
583 memcg_put_cache_ids();
584}
585EXPORT_SYMBOL_GPL(list_lru_destroy);