1 /* memcontrol.c - Memory Controller
3 * Copyright IBM Corporation, 2007
4 * Author Balbir Singh <balbir@linux.vnet.ibm.com>
6 * Copyright 2007 OpenVZ SWsoft Inc
7 * Author: Pavel Emelianov <xemul@openvz.org>
10 * Copyright (C) 2009 Nokia Corporation
11 * Author: Kirill A. Shutemov
13 * Kernel Memory Controller
14 * Copyright (C) 2012 Parallels Inc. and Google Inc.
15 * Authors: Glauber Costa and Suleiman Souhlal
17 * This program is free software; you can redistribute it and/or modify
18 * it under the terms of the GNU General Public License as published by
19 * the Free Software Foundation; either version 2 of the License, or
20 * (at your option) any later version.
22 * This program is distributed in the hope that it will be useful,
23 * but WITHOUT ANY WARRANTY; without even the implied warranty of
24 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
25 * GNU General Public License for more details.
28 #include <linux/res_counter.h>
29 #include <linux/memcontrol.h>
30 #include <linux/cgroup.h>
32 #include <linux/hugetlb.h>
33 #include <linux/pagemap.h>
34 #include <linux/smp.h>
35 #include <linux/page-flags.h>
36 #include <linux/backing-dev.h>
37 #include <linux/bit_spinlock.h>
38 #include <linux/rcupdate.h>
39 #include <linux/limits.h>
40 #include <linux/export.h>
41 #include <linux/mutex.h>
42 #include <linux/rbtree.h>
43 #include <linux/slab.h>
44 #include <linux/swap.h>
45 #include <linux/swapops.h>
46 #include <linux/spinlock.h>
47 #include <linux/eventfd.h>
48 #include <linux/sort.h>
50 #include <linux/seq_file.h>
51 #include <linux/vmalloc.h>
52 #include <linux/vmpressure.h>
53 #include <linux/mm_inline.h>
54 #include <linux/page_cgroup.h>
55 #include <linux/cpu.h>
56 #include <linux/oom.h>
60 #include <net/tcp_memcontrol.h>
62 #include <asm/uaccess.h>
64 #include <trace/events/vmscan.h>
66 struct cgroup_subsys mem_cgroup_subsys __read_mostly
;
67 EXPORT_SYMBOL(mem_cgroup_subsys
);
69 #define MEM_CGROUP_RECLAIM_RETRIES 5
70 static struct mem_cgroup
*root_mem_cgroup __read_mostly
;
72 #ifdef CONFIG_MEMCG_SWAP
73 /* Turned on only when memory cgroup is enabled && really_do_swap_account = 1 */
74 int do_swap_account __read_mostly
;
76 /* for remember boot option*/
77 #ifdef CONFIG_MEMCG_SWAP_ENABLED
78 static int really_do_swap_account __initdata
= 1;
80 static int really_do_swap_account __initdata
= 0;
84 #define do_swap_account 0
89 * Statistics for memory cgroup.
91 enum mem_cgroup_stat_index
{
93 * For MEM_CONTAINER_TYPE_ALL, usage = pagecache + rss.
95 MEM_CGROUP_STAT_CACHE
, /* # of pages charged as cache */
96 MEM_CGROUP_STAT_RSS
, /* # of pages charged as anon rss */
97 MEM_CGROUP_STAT_RSS_HUGE
, /* # of pages charged as anon huge */
98 MEM_CGROUP_STAT_FILE_MAPPED
, /* # of pages charged as file rss */
99 MEM_CGROUP_STAT_SWAP
, /* # of pages, swapped out */
100 MEM_CGROUP_STAT_NSTATS
,
103 static const char * const mem_cgroup_stat_names
[] = {
111 enum mem_cgroup_events_index
{
112 MEM_CGROUP_EVENTS_PGPGIN
, /* # of pages paged in */
113 MEM_CGROUP_EVENTS_PGPGOUT
, /* # of pages paged out */
114 MEM_CGROUP_EVENTS_PGFAULT
, /* # of page-faults */
115 MEM_CGROUP_EVENTS_PGMAJFAULT
, /* # of major page-faults */
116 MEM_CGROUP_EVENTS_NSTATS
,
119 static const char * const mem_cgroup_events_names
[] = {
126 static const char * const mem_cgroup_lru_names
[] = {
135 * Per memcg event counter is incremented at every pagein/pageout. With THP,
136 * it will be incremated by the number of pages. This counter is used for
137 * for trigger some periodic events. This is straightforward and better
138 * than using jiffies etc. to handle periodic memcg event.
140 enum mem_cgroup_events_target
{
141 MEM_CGROUP_TARGET_THRESH
,
142 MEM_CGROUP_TARGET_SOFTLIMIT
,
143 MEM_CGROUP_TARGET_NUMAINFO
,
146 #define THRESHOLDS_EVENTS_TARGET 128
147 #define SOFTLIMIT_EVENTS_TARGET 1024
148 #define NUMAINFO_EVENTS_TARGET 1024
150 struct mem_cgroup_stat_cpu
{
151 long count
[MEM_CGROUP_STAT_NSTATS
];
152 unsigned long events
[MEM_CGROUP_EVENTS_NSTATS
];
153 unsigned long nr_page_events
;
154 unsigned long targets
[MEM_CGROUP_NTARGETS
];
157 struct mem_cgroup_reclaim_iter
{
159 * last scanned hierarchy member. Valid only if last_dead_count
160 * matches memcg->dead_count of the hierarchy root group.
162 struct mem_cgroup
*last_visited
;
163 unsigned long last_dead_count
;
165 /* scan generation, increased every round-trip */
166 unsigned int generation
;
170 * per-zone information in memory controller.
172 struct mem_cgroup_per_zone
{
173 struct lruvec lruvec
;
174 unsigned long lru_size
[NR_LRU_LISTS
];
176 struct mem_cgroup_reclaim_iter reclaim_iter
[DEF_PRIORITY
+ 1];
178 struct rb_node tree_node
; /* RB tree node */
179 unsigned long long usage_in_excess
;/* Set to the value by which */
180 /* the soft limit is exceeded*/
182 struct mem_cgroup
*memcg
; /* Back pointer, we cannot */
183 /* use container_of */
186 struct mem_cgroup_per_node
{
187 struct mem_cgroup_per_zone zoneinfo
[MAX_NR_ZONES
];
190 struct mem_cgroup_lru_info
{
191 struct mem_cgroup_per_node
*nodeinfo
[0];
195 * Cgroups above their limits are maintained in a RB-Tree, independent of
196 * their hierarchy representation
199 struct mem_cgroup_tree_per_zone
{
200 struct rb_root rb_root
;
204 struct mem_cgroup_tree_per_node
{
205 struct mem_cgroup_tree_per_zone rb_tree_per_zone
[MAX_NR_ZONES
];
208 struct mem_cgroup_tree
{
209 struct mem_cgroup_tree_per_node
*rb_tree_per_node
[MAX_NUMNODES
];
212 static struct mem_cgroup_tree soft_limit_tree __read_mostly
;
214 struct mem_cgroup_threshold
{
215 struct eventfd_ctx
*eventfd
;
220 struct mem_cgroup_threshold_ary
{
221 /* An array index points to threshold just below or equal to usage. */
222 int current_threshold
;
223 /* Size of entries[] */
225 /* Array of thresholds */
226 struct mem_cgroup_threshold entries
[0];
229 struct mem_cgroup_thresholds
{
230 /* Primary thresholds array */
231 struct mem_cgroup_threshold_ary
*primary
;
233 * Spare threshold array.
234 * This is needed to make mem_cgroup_unregister_event() "never fail".
235 * It must be able to store at least primary->size - 1 entries.
237 struct mem_cgroup_threshold_ary
*spare
;
241 struct mem_cgroup_eventfd_list
{
242 struct list_head list
;
243 struct eventfd_ctx
*eventfd
;
246 static void mem_cgroup_threshold(struct mem_cgroup
*memcg
);
247 static void mem_cgroup_oom_notify(struct mem_cgroup
*memcg
);
250 * The memory controller data structure. The memory controller controls both
251 * page cache and RSS per cgroup. We would eventually like to provide
252 * statistics based on the statistics developed by Rik Van Riel for clock-pro,
253 * to help the administrator determine what knobs to tune.
255 * TODO: Add a water mark for the memory controller. Reclaim will begin when
256 * we hit the water mark. May be even add a low water mark, such that
257 * no reclaim occurs from a cgroup at it's low water mark, this is
258 * a feature that will be implemented much later in the future.
261 struct cgroup_subsys_state css
;
263 * the counter to account for memory usage
265 struct res_counter res
;
267 /* vmpressure notifications */
268 struct vmpressure vmpressure
;
272 * the counter to account for mem+swap usage.
274 struct res_counter memsw
;
277 * rcu_freeing is used only when freeing struct mem_cgroup,
278 * so put it into a union to avoid wasting more memory.
279 * It must be disjoint from the css field. It could be
280 * in a union with the res field, but res plays a much
281 * larger part in mem_cgroup life than memsw, and might
282 * be of interest, even at time of free, when debugging.
283 * So share rcu_head with the less interesting memsw.
285 struct rcu_head rcu_freeing
;
287 * We also need some space for a worker in deferred freeing.
288 * By the time we call it, rcu_freeing is no longer in use.
290 struct work_struct work_freeing
;
294 * the counter to account for kernel memory usage.
296 struct res_counter kmem
;
298 * Should the accounting and control be hierarchical, per subtree?
301 unsigned long kmem_account_flags
; /* See KMEM_ACCOUNTED_*, below */
305 atomic_t oom_wakeups
;
310 /* OOM-Killer disable */
311 int oom_kill_disable
;
313 /* set when res.limit == memsw.limit */
314 bool memsw_is_minimum
;
316 /* protect arrays of thresholds */
317 struct mutex thresholds_lock
;
319 /* thresholds for memory usage. RCU-protected */
320 struct mem_cgroup_thresholds thresholds
;
322 /* thresholds for mem+swap usage. RCU-protected */
323 struct mem_cgroup_thresholds memsw_thresholds
;
325 /* For oom notifier event fd */
326 struct list_head oom_notify
;
329 * Should we move charges of a task when a task is moved into this
330 * mem_cgroup ? And what type of charges should we move ?
332 unsigned long move_charge_at_immigrate
;
334 * set > 0 if pages under this cgroup are moving to other cgroup.
336 atomic_t moving_account
;
337 /* taken only while moving_account > 0 */
338 spinlock_t move_lock
;
342 struct mem_cgroup_stat_cpu __percpu
*stat
;
344 * used when a cpu is offlined or other synchronizations
345 * See mem_cgroup_read_stat().
347 struct mem_cgroup_stat_cpu nocpu_base
;
348 spinlock_t pcp_counter_lock
;
351 #if defined(CONFIG_MEMCG_KMEM) && defined(CONFIG_INET)
352 struct tcp_memcontrol tcp_mem
;
354 #if defined(CONFIG_MEMCG_KMEM)
355 /* analogous to slab_common's slab_caches list. per-memcg */
356 struct list_head memcg_slab_caches
;
357 /* Not a spinlock, we can take a lot of time walking the list */
358 struct mutex slab_caches_mutex
;
359 /* Index in the kmem_cache->memcg_params->memcg_caches array */
363 int last_scanned_node
;
365 nodemask_t scan_nodes
;
366 atomic_t numainfo_events
;
367 atomic_t numainfo_updating
;
371 * Per cgroup active and inactive list, similar to the
372 * per zone LRU lists.
374 * WARNING: This has to be the last element of the struct. Don't
375 * add new fields after this point.
377 struct mem_cgroup_lru_info info
;
380 static size_t memcg_size(void)
382 return sizeof(struct mem_cgroup
) +
383 nr_node_ids
* sizeof(struct mem_cgroup_per_node
*);
386 /* internal only representation about the status of kmem accounting. */
388 KMEM_ACCOUNTED_ACTIVE
= 0, /* accounted by this cgroup itself */
389 KMEM_ACCOUNTED_ACTIVATED
, /* static key enabled. */
390 KMEM_ACCOUNTED_DEAD
, /* dead memcg with pending kmem charges */
393 /* We account when limit is on, but only after call sites are patched */
394 #define KMEM_ACCOUNTED_MASK \
395 ((1 << KMEM_ACCOUNTED_ACTIVE) | (1 << KMEM_ACCOUNTED_ACTIVATED))
397 #ifdef CONFIG_MEMCG_KMEM
398 static inline void memcg_kmem_set_active(struct mem_cgroup
*memcg
)
400 set_bit(KMEM_ACCOUNTED_ACTIVE
, &memcg
->kmem_account_flags
);
403 static bool memcg_kmem_is_active(struct mem_cgroup
*memcg
)
405 return test_bit(KMEM_ACCOUNTED_ACTIVE
, &memcg
->kmem_account_flags
);
408 static void memcg_kmem_set_activated(struct mem_cgroup
*memcg
)
410 set_bit(KMEM_ACCOUNTED_ACTIVATED
, &memcg
->kmem_account_flags
);
413 static void memcg_kmem_clear_activated(struct mem_cgroup
*memcg
)
415 clear_bit(KMEM_ACCOUNTED_ACTIVATED
, &memcg
->kmem_account_flags
);
418 static void memcg_kmem_mark_dead(struct mem_cgroup
*memcg
)
420 if (test_bit(KMEM_ACCOUNTED_ACTIVE
, &memcg
->kmem_account_flags
))
421 set_bit(KMEM_ACCOUNTED_DEAD
, &memcg
->kmem_account_flags
);
424 static bool memcg_kmem_test_and_clear_dead(struct mem_cgroup
*memcg
)
426 return test_and_clear_bit(KMEM_ACCOUNTED_DEAD
,
427 &memcg
->kmem_account_flags
);
431 /* Stuffs for move charges at task migration. */
433 * Types of charges to be moved. "move_charge_at_immitgrate" and
434 * "immigrate_flags" are treated as a left-shifted bitmap of these types.
437 MOVE_CHARGE_TYPE_ANON
, /* private anonymous page and swap of it */
438 MOVE_CHARGE_TYPE_FILE
, /* file page(including tmpfs) and swap of it */
442 /* "mc" and its members are protected by cgroup_mutex */
443 static struct move_charge_struct
{
444 spinlock_t lock
; /* for from, to */
445 struct mem_cgroup
*from
;
446 struct mem_cgroup
*to
;
447 unsigned long immigrate_flags
;
448 unsigned long precharge
;
449 unsigned long moved_charge
;
450 unsigned long moved_swap
;
451 struct task_struct
*moving_task
; /* a task moving charges */
452 wait_queue_head_t waitq
; /* a waitq for other context */
454 .lock
= __SPIN_LOCK_UNLOCKED(mc
.lock
),
455 .waitq
= __WAIT_QUEUE_HEAD_INITIALIZER(mc
.waitq
),
458 static bool move_anon(void)
460 return test_bit(MOVE_CHARGE_TYPE_ANON
, &mc
.immigrate_flags
);
463 static bool move_file(void)
465 return test_bit(MOVE_CHARGE_TYPE_FILE
, &mc
.immigrate_flags
);
469 * Maximum loops in mem_cgroup_hierarchical_reclaim(), used for soft
470 * limit reclaim to prevent infinite loops, if they ever occur.
472 #define MEM_CGROUP_MAX_RECLAIM_LOOPS 100
473 #define MEM_CGROUP_MAX_SOFT_LIMIT_RECLAIM_LOOPS 2
476 MEM_CGROUP_CHARGE_TYPE_CACHE
= 0,
477 MEM_CGROUP_CHARGE_TYPE_ANON
,
478 MEM_CGROUP_CHARGE_TYPE_SWAPOUT
, /* for accounting swapcache */
479 MEM_CGROUP_CHARGE_TYPE_DROP
, /* a page was unused swap cache */
483 /* for encoding cft->private value on file */
491 #define MEMFILE_PRIVATE(x, val) ((x) << 16 | (val))
492 #define MEMFILE_TYPE(val) ((val) >> 16 & 0xffff)
493 #define MEMFILE_ATTR(val) ((val) & 0xffff)
494 /* Used for OOM nofiier */
495 #define OOM_CONTROL (0)
498 * Reclaim flags for mem_cgroup_hierarchical_reclaim
500 #define MEM_CGROUP_RECLAIM_NOSWAP_BIT 0x0
501 #define MEM_CGROUP_RECLAIM_NOSWAP (1 << MEM_CGROUP_RECLAIM_NOSWAP_BIT)
502 #define MEM_CGROUP_RECLAIM_SHRINK_BIT 0x1
503 #define MEM_CGROUP_RECLAIM_SHRINK (1 << MEM_CGROUP_RECLAIM_SHRINK_BIT)
506 * The memcg_create_mutex will be held whenever a new cgroup is created.
507 * As a consequence, any change that needs to protect against new child cgroups
508 * appearing has to hold it as well.
510 static DEFINE_MUTEX(memcg_create_mutex
);
512 static void mem_cgroup_get(struct mem_cgroup
*memcg
);
513 static void mem_cgroup_put(struct mem_cgroup
*memcg
);
516 struct mem_cgroup
*mem_cgroup_from_css(struct cgroup_subsys_state
*s
)
518 return container_of(s
, struct mem_cgroup
, css
);
521 /* Some nice accessors for the vmpressure. */
522 struct vmpressure
*memcg_to_vmpressure(struct mem_cgroup
*memcg
)
525 memcg
= root_mem_cgroup
;
526 return &memcg
->vmpressure
;
529 struct cgroup_subsys_state
*vmpressure_to_css(struct vmpressure
*vmpr
)
531 return &container_of(vmpr
, struct mem_cgroup
, vmpressure
)->css
;
534 struct vmpressure
*css_to_vmpressure(struct cgroup_subsys_state
*css
)
536 return &mem_cgroup_from_css(css
)->vmpressure
;
539 static inline bool mem_cgroup_is_root(struct mem_cgroup
*memcg
)
541 return (memcg
== root_mem_cgroup
);
544 /* Writing them here to avoid exposing memcg's inner layout */
545 #if defined(CONFIG_INET) && defined(CONFIG_MEMCG_KMEM)
547 void sock_update_memcg(struct sock
*sk
)
549 if (mem_cgroup_sockets_enabled
) {
550 struct mem_cgroup
*memcg
;
551 struct cg_proto
*cg_proto
;
553 BUG_ON(!sk
->sk_prot
->proto_cgroup
);
555 /* Socket cloning can throw us here with sk_cgrp already
556 * filled. It won't however, necessarily happen from
557 * process context. So the test for root memcg given
558 * the current task's memcg won't help us in this case.
560 * Respecting the original socket's memcg is a better
561 * decision in this case.
564 BUG_ON(mem_cgroup_is_root(sk
->sk_cgrp
->memcg
));
565 mem_cgroup_get(sk
->sk_cgrp
->memcg
);
570 memcg
= mem_cgroup_from_task(current
);
571 cg_proto
= sk
->sk_prot
->proto_cgroup(memcg
);
572 if (!mem_cgroup_is_root(memcg
) && memcg_proto_active(cg_proto
)) {
573 mem_cgroup_get(memcg
);
574 sk
->sk_cgrp
= cg_proto
;
579 EXPORT_SYMBOL(sock_update_memcg
);
581 void sock_release_memcg(struct sock
*sk
)
583 if (mem_cgroup_sockets_enabled
&& sk
->sk_cgrp
) {
584 struct mem_cgroup
*memcg
;
585 WARN_ON(!sk
->sk_cgrp
->memcg
);
586 memcg
= sk
->sk_cgrp
->memcg
;
587 mem_cgroup_put(memcg
);
591 struct cg_proto
*tcp_proto_cgroup(struct mem_cgroup
*memcg
)
593 if (!memcg
|| mem_cgroup_is_root(memcg
))
596 return &memcg
->tcp_mem
.cg_proto
;
598 EXPORT_SYMBOL(tcp_proto_cgroup
);
600 static void disarm_sock_keys(struct mem_cgroup
*memcg
)
602 if (!memcg_proto_activated(&memcg
->tcp_mem
.cg_proto
))
604 static_key_slow_dec(&memcg_socket_limit_enabled
);
607 static void disarm_sock_keys(struct mem_cgroup
*memcg
)
612 #ifdef CONFIG_MEMCG_KMEM
614 * This will be the memcg's index in each cache's ->memcg_params->memcg_caches.
615 * There are two main reasons for not using the css_id for this:
616 * 1) this works better in sparse environments, where we have a lot of memcgs,
617 * but only a few kmem-limited. Or also, if we have, for instance, 200
618 * memcgs, and none but the 200th is kmem-limited, we'd have to have a
619 * 200 entry array for that.
621 * 2) In order not to violate the cgroup API, we would like to do all memory
622 * allocation in ->create(). At that point, we haven't yet allocated the
623 * css_id. Having a separate index prevents us from messing with the cgroup
626 * The current size of the caches array is stored in
627 * memcg_limited_groups_array_size. It will double each time we have to
630 static DEFINE_IDA(kmem_limited_groups
);
631 int memcg_limited_groups_array_size
;
634 * MIN_SIZE is different than 1, because we would like to avoid going through
635 * the alloc/free process all the time. In a small machine, 4 kmem-limited
636 * cgroups is a reasonable guess. In the future, it could be a parameter or
637 * tunable, but that is strictly not necessary.
639 * MAX_SIZE should be as large as the number of css_ids. Ideally, we could get
640 * this constant directly from cgroup, but it is understandable that this is
641 * better kept as an internal representation in cgroup.c. In any case, the
642 * css_id space is not getting any smaller, and we don't have to necessarily
643 * increase ours as well if it increases.
645 #define MEMCG_CACHES_MIN_SIZE 4
646 #define MEMCG_CACHES_MAX_SIZE 65535
649 * A lot of the calls to the cache allocation functions are expected to be
650 * inlined by the compiler. Since the calls to memcg_kmem_get_cache are
651 * conditional to this static branch, we'll have to allow modules that does
652 * kmem_cache_alloc and the such to see this symbol as well
654 struct static_key memcg_kmem_enabled_key
;
655 EXPORT_SYMBOL(memcg_kmem_enabled_key
);
657 static void disarm_kmem_keys(struct mem_cgroup
*memcg
)
659 if (memcg_kmem_is_active(memcg
)) {
660 static_key_slow_dec(&memcg_kmem_enabled_key
);
661 ida_simple_remove(&kmem_limited_groups
, memcg
->kmemcg_id
);
664 * This check can't live in kmem destruction function,
665 * since the charges will outlive the cgroup
667 WARN_ON(res_counter_read_u64(&memcg
->kmem
, RES_USAGE
) != 0);
670 static void disarm_kmem_keys(struct mem_cgroup
*memcg
)
673 #endif /* CONFIG_MEMCG_KMEM */
675 static void disarm_static_keys(struct mem_cgroup
*memcg
)
677 disarm_sock_keys(memcg
);
678 disarm_kmem_keys(memcg
);
681 static void drain_all_stock_async(struct mem_cgroup
*memcg
);
683 static struct mem_cgroup_per_zone
*
684 mem_cgroup_zoneinfo(struct mem_cgroup
*memcg
, int nid
, int zid
)
686 VM_BUG_ON((unsigned)nid
>= nr_node_ids
);
687 return &memcg
->info
.nodeinfo
[nid
]->zoneinfo
[zid
];
690 struct cgroup_subsys_state
*mem_cgroup_css(struct mem_cgroup
*memcg
)
695 static struct mem_cgroup_per_zone
*
696 page_cgroup_zoneinfo(struct mem_cgroup
*memcg
, struct page
*page
)
698 int nid
= page_to_nid(page
);
699 int zid
= page_zonenum(page
);
701 return mem_cgroup_zoneinfo(memcg
, nid
, zid
);
704 static struct mem_cgroup_tree_per_zone
*
705 soft_limit_tree_node_zone(int nid
, int zid
)
707 return &soft_limit_tree
.rb_tree_per_node
[nid
]->rb_tree_per_zone
[zid
];
710 static struct mem_cgroup_tree_per_zone
*
711 soft_limit_tree_from_page(struct page
*page
)
713 int nid
= page_to_nid(page
);
714 int zid
= page_zonenum(page
);
716 return &soft_limit_tree
.rb_tree_per_node
[nid
]->rb_tree_per_zone
[zid
];
720 __mem_cgroup_insert_exceeded(struct mem_cgroup
*memcg
,
721 struct mem_cgroup_per_zone
*mz
,
722 struct mem_cgroup_tree_per_zone
*mctz
,
723 unsigned long long new_usage_in_excess
)
725 struct rb_node
**p
= &mctz
->rb_root
.rb_node
;
726 struct rb_node
*parent
= NULL
;
727 struct mem_cgroup_per_zone
*mz_node
;
732 mz
->usage_in_excess
= new_usage_in_excess
;
733 if (!mz
->usage_in_excess
)
737 mz_node
= rb_entry(parent
, struct mem_cgroup_per_zone
,
739 if (mz
->usage_in_excess
< mz_node
->usage_in_excess
)
742 * We can't avoid mem cgroups that are over their soft
743 * limit by the same amount
745 else if (mz
->usage_in_excess
>= mz_node
->usage_in_excess
)
748 rb_link_node(&mz
->tree_node
, parent
, p
);
749 rb_insert_color(&mz
->tree_node
, &mctz
->rb_root
);
754 __mem_cgroup_remove_exceeded(struct mem_cgroup
*memcg
,
755 struct mem_cgroup_per_zone
*mz
,
756 struct mem_cgroup_tree_per_zone
*mctz
)
760 rb_erase(&mz
->tree_node
, &mctz
->rb_root
);
765 mem_cgroup_remove_exceeded(struct mem_cgroup
*memcg
,
766 struct mem_cgroup_per_zone
*mz
,
767 struct mem_cgroup_tree_per_zone
*mctz
)
769 spin_lock(&mctz
->lock
);
770 __mem_cgroup_remove_exceeded(memcg
, mz
, mctz
);
771 spin_unlock(&mctz
->lock
);
775 static void mem_cgroup_update_tree(struct mem_cgroup
*memcg
, struct page
*page
)
777 unsigned long long excess
;
778 struct mem_cgroup_per_zone
*mz
;
779 struct mem_cgroup_tree_per_zone
*mctz
;
780 int nid
= page_to_nid(page
);
781 int zid
= page_zonenum(page
);
782 mctz
= soft_limit_tree_from_page(page
);
785 * Necessary to update all ancestors when hierarchy is used.
786 * because their event counter is not touched.
788 for (; memcg
; memcg
= parent_mem_cgroup(memcg
)) {
789 mz
= mem_cgroup_zoneinfo(memcg
, nid
, zid
);
790 excess
= res_counter_soft_limit_excess(&memcg
->res
);
792 * We have to update the tree if mz is on RB-tree or
793 * mem is over its softlimit.
795 if (excess
|| mz
->on_tree
) {
796 spin_lock(&mctz
->lock
);
797 /* if on-tree, remove it */
799 __mem_cgroup_remove_exceeded(memcg
, mz
, mctz
);
801 * Insert again. mz->usage_in_excess will be updated.
802 * If excess is 0, no tree ops.
804 __mem_cgroup_insert_exceeded(memcg
, mz
, mctz
, excess
);
805 spin_unlock(&mctz
->lock
);
810 static void mem_cgroup_remove_from_trees(struct mem_cgroup
*memcg
)
813 struct mem_cgroup_per_zone
*mz
;
814 struct mem_cgroup_tree_per_zone
*mctz
;
816 for_each_node(node
) {
817 for (zone
= 0; zone
< MAX_NR_ZONES
; zone
++) {
818 mz
= mem_cgroup_zoneinfo(memcg
, node
, zone
);
819 mctz
= soft_limit_tree_node_zone(node
, zone
);
820 mem_cgroup_remove_exceeded(memcg
, mz
, mctz
);
825 static struct mem_cgroup_per_zone
*
826 __mem_cgroup_largest_soft_limit_node(struct mem_cgroup_tree_per_zone
*mctz
)
828 struct rb_node
*rightmost
= NULL
;
829 struct mem_cgroup_per_zone
*mz
;
833 rightmost
= rb_last(&mctz
->rb_root
);
835 goto done
; /* Nothing to reclaim from */
837 mz
= rb_entry(rightmost
, struct mem_cgroup_per_zone
, tree_node
);
839 * Remove the node now but someone else can add it back,
840 * we will to add it back at the end of reclaim to its correct
841 * position in the tree.
843 __mem_cgroup_remove_exceeded(mz
->memcg
, mz
, mctz
);
844 if (!res_counter_soft_limit_excess(&mz
->memcg
->res
) ||
845 !css_tryget(&mz
->memcg
->css
))
851 static struct mem_cgroup_per_zone
*
852 mem_cgroup_largest_soft_limit_node(struct mem_cgroup_tree_per_zone
*mctz
)
854 struct mem_cgroup_per_zone
*mz
;
856 spin_lock(&mctz
->lock
);
857 mz
= __mem_cgroup_largest_soft_limit_node(mctz
);
858 spin_unlock(&mctz
->lock
);
863 * Implementation Note: reading percpu statistics for memcg.
865 * Both of vmstat[] and percpu_counter has threshold and do periodic
866 * synchronization to implement "quick" read. There are trade-off between
867 * reading cost and precision of value. Then, we may have a chance to implement
868 * a periodic synchronizion of counter in memcg's counter.
870 * But this _read() function is used for user interface now. The user accounts
871 * memory usage by memory cgroup and he _always_ requires exact value because
872 * he accounts memory. Even if we provide quick-and-fuzzy read, we always
873 * have to visit all online cpus and make sum. So, for now, unnecessary
874 * synchronization is not implemented. (just implemented for cpu hotplug)
876 * If there are kernel internal actions which can make use of some not-exact
877 * value, and reading all cpu value can be performance bottleneck in some
878 * common workload, threashold and synchonization as vmstat[] should be
881 static long mem_cgroup_read_stat(struct mem_cgroup
*memcg
,
882 enum mem_cgroup_stat_index idx
)
888 for_each_online_cpu(cpu
)
889 val
+= per_cpu(memcg
->stat
->count
[idx
], cpu
);
890 #ifdef CONFIG_HOTPLUG_CPU
891 spin_lock(&memcg
->pcp_counter_lock
);
892 val
+= memcg
->nocpu_base
.count
[idx
];
893 spin_unlock(&memcg
->pcp_counter_lock
);
899 static void mem_cgroup_swap_statistics(struct mem_cgroup
*memcg
,
902 int val
= (charge
) ? 1 : -1;
903 this_cpu_add(memcg
->stat
->count
[MEM_CGROUP_STAT_SWAP
], val
);
906 static unsigned long mem_cgroup_read_events(struct mem_cgroup
*memcg
,
907 enum mem_cgroup_events_index idx
)
909 unsigned long val
= 0;
912 for_each_online_cpu(cpu
)
913 val
+= per_cpu(memcg
->stat
->events
[idx
], cpu
);
914 #ifdef CONFIG_HOTPLUG_CPU
915 spin_lock(&memcg
->pcp_counter_lock
);
916 val
+= memcg
->nocpu_base
.events
[idx
];
917 spin_unlock(&memcg
->pcp_counter_lock
);
922 static void mem_cgroup_charge_statistics(struct mem_cgroup
*memcg
,
924 bool anon
, int nr_pages
)
929 * Here, RSS means 'mapped anon' and anon's SwapCache. Shmem/tmpfs is
930 * counted as CACHE even if it's on ANON LRU.
933 __this_cpu_add(memcg
->stat
->count
[MEM_CGROUP_STAT_RSS
],
936 __this_cpu_add(memcg
->stat
->count
[MEM_CGROUP_STAT_CACHE
],
939 if (PageTransHuge(page
))
940 __this_cpu_add(memcg
->stat
->count
[MEM_CGROUP_STAT_RSS_HUGE
],
943 /* pagein of a big page is an event. So, ignore page size */
945 __this_cpu_inc(memcg
->stat
->events
[MEM_CGROUP_EVENTS_PGPGIN
]);
947 __this_cpu_inc(memcg
->stat
->events
[MEM_CGROUP_EVENTS_PGPGOUT
]);
948 nr_pages
= -nr_pages
; /* for event */
951 __this_cpu_add(memcg
->stat
->nr_page_events
, nr_pages
);
957 mem_cgroup_get_lru_size(struct lruvec
*lruvec
, enum lru_list lru
)
959 struct mem_cgroup_per_zone
*mz
;
961 mz
= container_of(lruvec
, struct mem_cgroup_per_zone
, lruvec
);
962 return mz
->lru_size
[lru
];
966 mem_cgroup_zone_nr_lru_pages(struct mem_cgroup
*memcg
, int nid
, int zid
,
967 unsigned int lru_mask
)
969 struct mem_cgroup_per_zone
*mz
;
971 unsigned long ret
= 0;
973 mz
= mem_cgroup_zoneinfo(memcg
, nid
, zid
);
976 if (BIT(lru
) & lru_mask
)
977 ret
+= mz
->lru_size
[lru
];
983 mem_cgroup_node_nr_lru_pages(struct mem_cgroup
*memcg
,
984 int nid
, unsigned int lru_mask
)
989 for (zid
= 0; zid
< MAX_NR_ZONES
; zid
++)
990 total
+= mem_cgroup_zone_nr_lru_pages(memcg
,
996 static unsigned long mem_cgroup_nr_lru_pages(struct mem_cgroup
*memcg
,
997 unsigned int lru_mask
)
1002 for_each_node_state(nid
, N_MEMORY
)
1003 total
+= mem_cgroup_node_nr_lru_pages(memcg
, nid
, lru_mask
);
1007 static bool mem_cgroup_event_ratelimit(struct mem_cgroup
*memcg
,
1008 enum mem_cgroup_events_target target
)
1010 unsigned long val
, next
;
1012 val
= __this_cpu_read(memcg
->stat
->nr_page_events
);
1013 next
= __this_cpu_read(memcg
->stat
->targets
[target
]);
1014 /* from time_after() in jiffies.h */
1015 if ((long)next
- (long)val
< 0) {
1017 case MEM_CGROUP_TARGET_THRESH
:
1018 next
= val
+ THRESHOLDS_EVENTS_TARGET
;
1020 case MEM_CGROUP_TARGET_SOFTLIMIT
:
1021 next
= val
+ SOFTLIMIT_EVENTS_TARGET
;
1023 case MEM_CGROUP_TARGET_NUMAINFO
:
1024 next
= val
+ NUMAINFO_EVENTS_TARGET
;
1029 __this_cpu_write(memcg
->stat
->targets
[target
], next
);
1036 * Check events in order.
1039 static void memcg_check_events(struct mem_cgroup
*memcg
, struct page
*page
)
1042 /* threshold event is triggered in finer grain than soft limit */
1043 if (unlikely(mem_cgroup_event_ratelimit(memcg
,
1044 MEM_CGROUP_TARGET_THRESH
))) {
1046 bool do_numainfo __maybe_unused
;
1048 do_softlimit
= mem_cgroup_event_ratelimit(memcg
,
1049 MEM_CGROUP_TARGET_SOFTLIMIT
);
1050 #if MAX_NUMNODES > 1
1051 do_numainfo
= mem_cgroup_event_ratelimit(memcg
,
1052 MEM_CGROUP_TARGET_NUMAINFO
);
1056 mem_cgroup_threshold(memcg
);
1057 if (unlikely(do_softlimit
))
1058 mem_cgroup_update_tree(memcg
, page
);
1059 #if MAX_NUMNODES > 1
1060 if (unlikely(do_numainfo
))
1061 atomic_inc(&memcg
->numainfo_events
);
1067 struct mem_cgroup
*mem_cgroup_from_cont(struct cgroup
*cont
)
1069 return mem_cgroup_from_css(
1070 cgroup_subsys_state(cont
, mem_cgroup_subsys_id
));
1073 struct mem_cgroup
*mem_cgroup_from_task(struct task_struct
*p
)
1076 * mm_update_next_owner() may clear mm->owner to NULL
1077 * if it races with swapoff, page migration, etc.
1078 * So this can be called with p == NULL.
1083 return mem_cgroup_from_css(task_subsys_state(p
, mem_cgroup_subsys_id
));
1086 struct mem_cgroup
*try_get_mem_cgroup_from_mm(struct mm_struct
*mm
)
1088 struct mem_cgroup
*memcg
= NULL
;
1093 * Because we have no locks, mm->owner's may be being moved to other
1094 * cgroup. We use css_tryget() here even if this looks
1095 * pessimistic (rather than adding locks here).
1099 memcg
= mem_cgroup_from_task(rcu_dereference(mm
->owner
));
1100 if (unlikely(!memcg
))
1102 } while (!css_tryget(&memcg
->css
));
1108 * Returns a next (in a pre-order walk) alive memcg (with elevated css
1109 * ref. count) or NULL if the whole root's subtree has been visited.
1111 * helper function to be used by mem_cgroup_iter
1113 static struct mem_cgroup
*__mem_cgroup_iter_next(struct mem_cgroup
*root
,
1114 struct mem_cgroup
*last_visited
)
1116 struct cgroup
*prev_cgroup
, *next_cgroup
;
1119 * Root is not visited by cgroup iterators so it needs an
1125 prev_cgroup
= (last_visited
== root
) ? NULL
1126 : last_visited
->css
.cgroup
;
1128 next_cgroup
= cgroup_next_descendant_pre(
1129 prev_cgroup
, root
->css
.cgroup
);
1132 * Even if we found a group we have to make sure it is
1133 * alive. css && !memcg means that the groups should be
1134 * skipped and we should continue the tree walk.
1135 * last_visited css is safe to use because it is
1136 * protected by css_get and the tree walk is rcu safe.
1139 struct mem_cgroup
*mem
= mem_cgroup_from_cont(
1141 if (css_tryget(&mem
->css
))
1144 prev_cgroup
= next_cgroup
;
1153 * mem_cgroup_iter - iterate over memory cgroup hierarchy
1154 * @root: hierarchy root
1155 * @prev: previously returned memcg, NULL on first invocation
1156 * @reclaim: cookie for shared reclaim walks, NULL for full walks
1158 * Returns references to children of the hierarchy below @root, or
1159 * @root itself, or %NULL after a full round-trip.
1161 * Caller must pass the return value in @prev on subsequent
1162 * invocations for reference counting, or use mem_cgroup_iter_break()
1163 * to cancel a hierarchy walk before the round-trip is complete.
1165 * Reclaimers can specify a zone and a priority level in @reclaim to
1166 * divide up the memcgs in the hierarchy among all concurrent
1167 * reclaimers operating on the same zone and priority.
1169 struct mem_cgroup
*mem_cgroup_iter(struct mem_cgroup
*root
,
1170 struct mem_cgroup
*prev
,
1171 struct mem_cgroup_reclaim_cookie
*reclaim
)
1173 struct mem_cgroup
*memcg
= NULL
;
1174 struct mem_cgroup
*last_visited
= NULL
;
1175 unsigned long uninitialized_var(dead_count
);
1177 if (mem_cgroup_disabled())
1181 root
= root_mem_cgroup
;
1183 if (prev
&& !reclaim
)
1184 last_visited
= prev
;
1186 if (!root
->use_hierarchy
&& root
!= root_mem_cgroup
) {
1194 struct mem_cgroup_reclaim_iter
*uninitialized_var(iter
);
1197 int nid
= zone_to_nid(reclaim
->zone
);
1198 int zid
= zone_idx(reclaim
->zone
);
1199 struct mem_cgroup_per_zone
*mz
;
1201 mz
= mem_cgroup_zoneinfo(root
, nid
, zid
);
1202 iter
= &mz
->reclaim_iter
[reclaim
->priority
];
1203 if (prev
&& reclaim
->generation
!= iter
->generation
) {
1204 iter
->last_visited
= NULL
;
1209 * If the dead_count mismatches, a destruction
1210 * has happened or is happening concurrently.
1211 * If the dead_count matches, a destruction
1212 * might still happen concurrently, but since
1213 * we checked under RCU, that destruction
1214 * won't free the object until we release the
1215 * RCU reader lock. Thus, the dead_count
1216 * check verifies the pointer is still valid,
1217 * css_tryget() verifies the cgroup pointed to
1220 dead_count
= atomic_read(&root
->dead_count
);
1221 if (dead_count
== iter
->last_dead_count
) {
1223 last_visited
= iter
->last_visited
;
1224 if (last_visited
&& last_visited
!= root
&&
1225 !css_tryget(&last_visited
->css
))
1226 last_visited
= NULL
;
1230 memcg
= __mem_cgroup_iter_next(root
, last_visited
);
1233 if (last_visited
&& last_visited
!= root
)
1234 css_put(&last_visited
->css
);
1236 iter
->last_visited
= memcg
;
1238 iter
->last_dead_count
= dead_count
;
1242 else if (!prev
&& memcg
)
1243 reclaim
->generation
= iter
->generation
;
1252 if (prev
&& prev
!= root
)
1253 css_put(&prev
->css
);
1259 * mem_cgroup_iter_break - abort a hierarchy walk prematurely
1260 * @root: hierarchy root
1261 * @prev: last visited hierarchy member as returned by mem_cgroup_iter()
1263 void mem_cgroup_iter_break(struct mem_cgroup
*root
,
1264 struct mem_cgroup
*prev
)
1267 root
= root_mem_cgroup
;
1268 if (prev
&& prev
!= root
)
1269 css_put(&prev
->css
);
1273 * Iteration constructs for visiting all cgroups (under a tree). If
1274 * loops are exited prematurely (break), mem_cgroup_iter_break() must
1275 * be used for reference counting.
1277 #define for_each_mem_cgroup_tree(iter, root) \
1278 for (iter = mem_cgroup_iter(root, NULL, NULL); \
1280 iter = mem_cgroup_iter(root, iter, NULL))
1282 #define for_each_mem_cgroup(iter) \
1283 for (iter = mem_cgroup_iter(NULL, NULL, NULL); \
1285 iter = mem_cgroup_iter(NULL, iter, NULL))
1287 void __mem_cgroup_count_vm_event(struct mm_struct
*mm
, enum vm_event_item idx
)
1289 struct mem_cgroup
*memcg
;
1292 memcg
= mem_cgroup_from_task(rcu_dereference(mm
->owner
));
1293 if (unlikely(!memcg
))
1298 this_cpu_inc(memcg
->stat
->events
[MEM_CGROUP_EVENTS_PGFAULT
]);
1301 this_cpu_inc(memcg
->stat
->events
[MEM_CGROUP_EVENTS_PGMAJFAULT
]);
1309 EXPORT_SYMBOL(__mem_cgroup_count_vm_event
);
1312 * mem_cgroup_zone_lruvec - get the lru list vector for a zone and memcg
1313 * @zone: zone of the wanted lruvec
1314 * @memcg: memcg of the wanted lruvec
1316 * Returns the lru list vector holding pages for the given @zone and
1317 * @mem. This can be the global zone lruvec, if the memory controller
1320 struct lruvec
*mem_cgroup_zone_lruvec(struct zone
*zone
,
1321 struct mem_cgroup
*memcg
)
1323 struct mem_cgroup_per_zone
*mz
;
1324 struct lruvec
*lruvec
;
1326 if (mem_cgroup_disabled()) {
1327 lruvec
= &zone
->lruvec
;
1331 mz
= mem_cgroup_zoneinfo(memcg
, zone_to_nid(zone
), zone_idx(zone
));
1332 lruvec
= &mz
->lruvec
;
1335 * Since a node can be onlined after the mem_cgroup was created,
1336 * we have to be prepared to initialize lruvec->zone here;
1337 * and if offlined then reonlined, we need to reinitialize it.
1339 if (unlikely(lruvec
->zone
!= zone
))
1340 lruvec
->zone
= zone
;
1345 * Following LRU functions are allowed to be used without PCG_LOCK.
1346 * Operations are called by routine of global LRU independently from memcg.
1347 * What we have to take care of here is validness of pc->mem_cgroup.
1349 * Changes to pc->mem_cgroup happens when
1352 * In typical case, "charge" is done before add-to-lru. Exception is SwapCache.
1353 * It is added to LRU before charge.
1354 * If PCG_USED bit is not set, page_cgroup is not added to this private LRU.
1355 * When moving account, the page is not on LRU. It's isolated.
1359 * mem_cgroup_page_lruvec - return lruvec for adding an lru page
1361 * @zone: zone of the page
1363 struct lruvec
*mem_cgroup_page_lruvec(struct page
*page
, struct zone
*zone
)
1365 struct mem_cgroup_per_zone
*mz
;
1366 struct mem_cgroup
*memcg
;
1367 struct page_cgroup
*pc
;
1368 struct lruvec
*lruvec
;
1370 if (mem_cgroup_disabled()) {
1371 lruvec
= &zone
->lruvec
;
1375 pc
= lookup_page_cgroup(page
);
1376 memcg
= pc
->mem_cgroup
;
1379 * Surreptitiously switch any uncharged offlist page to root:
1380 * an uncharged page off lru does nothing to secure
1381 * its former mem_cgroup from sudden removal.
1383 * Our caller holds lru_lock, and PageCgroupUsed is updated
1384 * under page_cgroup lock: between them, they make all uses
1385 * of pc->mem_cgroup safe.
1387 if (!PageLRU(page
) && !PageCgroupUsed(pc
) && memcg
!= root_mem_cgroup
)
1388 pc
->mem_cgroup
= memcg
= root_mem_cgroup
;
1390 mz
= page_cgroup_zoneinfo(memcg
, page
);
1391 lruvec
= &mz
->lruvec
;
1394 * Since a node can be onlined after the mem_cgroup was created,
1395 * we have to be prepared to initialize lruvec->zone here;
1396 * and if offlined then reonlined, we need to reinitialize it.
1398 if (unlikely(lruvec
->zone
!= zone
))
1399 lruvec
->zone
= zone
;
1404 * mem_cgroup_update_lru_size - account for adding or removing an lru page
1405 * @lruvec: mem_cgroup per zone lru vector
1406 * @lru: index of lru list the page is sitting on
1407 * @nr_pages: positive when adding or negative when removing
1409 * This function must be called when a page is added to or removed from an
1412 void mem_cgroup_update_lru_size(struct lruvec
*lruvec
, enum lru_list lru
,
1415 struct mem_cgroup_per_zone
*mz
;
1416 unsigned long *lru_size
;
1418 if (mem_cgroup_disabled())
1421 mz
= container_of(lruvec
, struct mem_cgroup_per_zone
, lruvec
);
1422 lru_size
= mz
->lru_size
+ lru
;
1423 *lru_size
+= nr_pages
;
1424 VM_BUG_ON((long)(*lru_size
) < 0);
1428 * Checks whether given mem is same or in the root_mem_cgroup's
1431 bool __mem_cgroup_same_or_subtree(const struct mem_cgroup
*root_memcg
,
1432 struct mem_cgroup
*memcg
)
1434 if (root_memcg
== memcg
)
1436 if (!root_memcg
->use_hierarchy
|| !memcg
)
1438 return css_is_ancestor(&memcg
->css
, &root_memcg
->css
);
1441 static bool mem_cgroup_same_or_subtree(const struct mem_cgroup
*root_memcg
,
1442 struct mem_cgroup
*memcg
)
1447 ret
= __mem_cgroup_same_or_subtree(root_memcg
, memcg
);
1452 int task_in_mem_cgroup(struct task_struct
*task
, const struct mem_cgroup
*memcg
)
1455 struct mem_cgroup
*curr
= NULL
;
1456 struct task_struct
*p
;
1458 p
= find_lock_task_mm(task
);
1460 curr
= try_get_mem_cgroup_from_mm(p
->mm
);
1464 * All threads may have already detached their mm's, but the oom
1465 * killer still needs to detect if they have already been oom
1466 * killed to prevent needlessly killing additional tasks.
1469 curr
= mem_cgroup_from_task(task
);
1471 css_get(&curr
->css
);
1477 * We should check use_hierarchy of "memcg" not "curr". Because checking
1478 * use_hierarchy of "curr" here make this function true if hierarchy is
1479 * enabled in "curr" and "curr" is a child of "memcg" in *cgroup*
1480 * hierarchy(even if use_hierarchy is disabled in "memcg").
1482 ret
= mem_cgroup_same_or_subtree(memcg
, curr
);
1483 css_put(&curr
->css
);
1487 int mem_cgroup_inactive_anon_is_low(struct lruvec
*lruvec
)
1489 unsigned long inactive_ratio
;
1490 unsigned long inactive
;
1491 unsigned long active
;
1494 inactive
= mem_cgroup_get_lru_size(lruvec
, LRU_INACTIVE_ANON
);
1495 active
= mem_cgroup_get_lru_size(lruvec
, LRU_ACTIVE_ANON
);
1497 gb
= (inactive
+ active
) >> (30 - PAGE_SHIFT
);
1499 inactive_ratio
= int_sqrt(10 * gb
);
1503 return inactive
* inactive_ratio
< active
;
1506 #define mem_cgroup_from_res_counter(counter, member) \
1507 container_of(counter, struct mem_cgroup, member)
1510 * mem_cgroup_margin - calculate chargeable space of a memory cgroup
1511 * @memcg: the memory cgroup
1513 * Returns the maximum amount of memory @mem can be charged with, in
1516 static unsigned long mem_cgroup_margin(struct mem_cgroup
*memcg
)
1518 unsigned long long margin
;
1520 margin
= res_counter_margin(&memcg
->res
);
1521 if (do_swap_account
)
1522 margin
= min(margin
, res_counter_margin(&memcg
->memsw
));
1523 return margin
>> PAGE_SHIFT
;
1526 int mem_cgroup_swappiness(struct mem_cgroup
*memcg
)
1528 struct cgroup
*cgrp
= memcg
->css
.cgroup
;
1531 if (cgrp
->parent
== NULL
)
1532 return vm_swappiness
;
1534 return memcg
->swappiness
;
1538 * memcg->moving_account is used for checking possibility that some thread is
1539 * calling move_account(). When a thread on CPU-A starts moving pages under
1540 * a memcg, other threads should check memcg->moving_account under
1541 * rcu_read_lock(), like this:
1545 * memcg->moving_account+1 if (memcg->mocing_account)
1547 * synchronize_rcu() update something.
1552 /* for quick checking without looking up memcg */
1553 atomic_t memcg_moving __read_mostly
;
1555 static void mem_cgroup_start_move(struct mem_cgroup
*memcg
)
1557 atomic_inc(&memcg_moving
);
1558 atomic_inc(&memcg
->moving_account
);
1562 static void mem_cgroup_end_move(struct mem_cgroup
*memcg
)
1565 * Now, mem_cgroup_clear_mc() may call this function with NULL.
1566 * We check NULL in callee rather than caller.
1569 atomic_dec(&memcg_moving
);
1570 atomic_dec(&memcg
->moving_account
);
1575 * 2 routines for checking "mem" is under move_account() or not.
1577 * mem_cgroup_stolen() - checking whether a cgroup is mc.from or not. This
1578 * is used for avoiding races in accounting. If true,
1579 * pc->mem_cgroup may be overwritten.
1581 * mem_cgroup_under_move() - checking a cgroup is mc.from or mc.to or
1582 * under hierarchy of moving cgroups. This is for
1583 * waiting at hith-memory prressure caused by "move".
1586 static bool mem_cgroup_stolen(struct mem_cgroup
*memcg
)
1588 VM_BUG_ON(!rcu_read_lock_held());
1589 return atomic_read(&memcg
->moving_account
) > 0;
1592 static bool mem_cgroup_under_move(struct mem_cgroup
*memcg
)
1594 struct mem_cgroup
*from
;
1595 struct mem_cgroup
*to
;
1598 * Unlike task_move routines, we access mc.to, mc.from not under
1599 * mutual exclusion by cgroup_mutex. Here, we take spinlock instead.
1601 spin_lock(&mc
.lock
);
1607 ret
= mem_cgroup_same_or_subtree(memcg
, from
)
1608 || mem_cgroup_same_or_subtree(memcg
, to
);
1610 spin_unlock(&mc
.lock
);
1614 static bool mem_cgroup_wait_acct_move(struct mem_cgroup
*memcg
)
1616 if (mc
.moving_task
&& current
!= mc
.moving_task
) {
1617 if (mem_cgroup_under_move(memcg
)) {
1619 prepare_to_wait(&mc
.waitq
, &wait
, TASK_INTERRUPTIBLE
);
1620 /* moving charge context might have finished. */
1623 finish_wait(&mc
.waitq
, &wait
);
1631 * Take this lock when
1632 * - a code tries to modify page's memcg while it's USED.
1633 * - a code tries to modify page state accounting in a memcg.
1634 * see mem_cgroup_stolen(), too.
1636 static void move_lock_mem_cgroup(struct mem_cgroup
*memcg
,
1637 unsigned long *flags
)
1639 spin_lock_irqsave(&memcg
->move_lock
, *flags
);
1642 static void move_unlock_mem_cgroup(struct mem_cgroup
*memcg
,
1643 unsigned long *flags
)
1645 spin_unlock_irqrestore(&memcg
->move_lock
, *flags
);
1648 #define K(x) ((x) << (PAGE_SHIFT-10))
1650 * mem_cgroup_print_oom_info: Print OOM information relevant to memory controller.
1651 * @memcg: The memory cgroup that went over limit
1652 * @p: Task that is going to be killed
1654 * NOTE: @memcg and @p's mem_cgroup can be different when hierarchy is
1657 void mem_cgroup_print_oom_info(struct mem_cgroup
*memcg
, struct task_struct
*p
)
1659 struct cgroup
*task_cgrp
;
1660 struct cgroup
*mem_cgrp
;
1662 * Need a buffer in BSS, can't rely on allocations. The code relies
1663 * on the assumption that OOM is serialized for memory controller.
1664 * If this assumption is broken, revisit this code.
1666 static char memcg_name
[PATH_MAX
];
1668 struct mem_cgroup
*iter
;
1676 mem_cgrp
= memcg
->css
.cgroup
;
1677 task_cgrp
= task_cgroup(p
, mem_cgroup_subsys_id
);
1679 ret
= cgroup_path(task_cgrp
, memcg_name
, PATH_MAX
);
1682 * Unfortunately, we are unable to convert to a useful name
1683 * But we'll still print out the usage information
1690 pr_info("Task in %s killed", memcg_name
);
1693 ret
= cgroup_path(mem_cgrp
, memcg_name
, PATH_MAX
);
1701 * Continues from above, so we don't need an KERN_ level
1703 pr_cont(" as a result of limit of %s\n", memcg_name
);
1706 pr_info("memory: usage %llukB, limit %llukB, failcnt %llu\n",
1707 res_counter_read_u64(&memcg
->res
, RES_USAGE
) >> 10,
1708 res_counter_read_u64(&memcg
->res
, RES_LIMIT
) >> 10,
1709 res_counter_read_u64(&memcg
->res
, RES_FAILCNT
));
1710 pr_info("memory+swap: usage %llukB, limit %llukB, failcnt %llu\n",
1711 res_counter_read_u64(&memcg
->memsw
, RES_USAGE
) >> 10,
1712 res_counter_read_u64(&memcg
->memsw
, RES_LIMIT
) >> 10,
1713 res_counter_read_u64(&memcg
->memsw
, RES_FAILCNT
));
1714 pr_info("kmem: usage %llukB, limit %llukB, failcnt %llu\n",
1715 res_counter_read_u64(&memcg
->kmem
, RES_USAGE
) >> 10,
1716 res_counter_read_u64(&memcg
->kmem
, RES_LIMIT
) >> 10,
1717 res_counter_read_u64(&memcg
->kmem
, RES_FAILCNT
));
1719 for_each_mem_cgroup_tree(iter
, memcg
) {
1720 pr_info("Memory cgroup stats");
1723 ret
= cgroup_path(iter
->css
.cgroup
, memcg_name
, PATH_MAX
);
1725 pr_cont(" for %s", memcg_name
);
1729 for (i
= 0; i
< MEM_CGROUP_STAT_NSTATS
; i
++) {
1730 if (i
== MEM_CGROUP_STAT_SWAP
&& !do_swap_account
)
1732 pr_cont(" %s:%ldKB", mem_cgroup_stat_names
[i
],
1733 K(mem_cgroup_read_stat(iter
, i
)));
1736 for (i
= 0; i
< NR_LRU_LISTS
; i
++)
1737 pr_cont(" %s:%luKB", mem_cgroup_lru_names
[i
],
1738 K(mem_cgroup_nr_lru_pages(iter
, BIT(i
))));
1745 * This function returns the number of memcg under hierarchy tree. Returns
1746 * 1(self count) if no children.
1748 static int mem_cgroup_count_children(struct mem_cgroup
*memcg
)
1751 struct mem_cgroup
*iter
;
1753 for_each_mem_cgroup_tree(iter
, memcg
)
1759 * Return the memory (and swap, if configured) limit for a memcg.
1761 static u64
mem_cgroup_get_limit(struct mem_cgroup
*memcg
)
1765 limit
= res_counter_read_u64(&memcg
->res
, RES_LIMIT
);
1768 * Do not consider swap space if we cannot swap due to swappiness
1770 if (mem_cgroup_swappiness(memcg
)) {
1773 limit
+= total_swap_pages
<< PAGE_SHIFT
;
1774 memsw
= res_counter_read_u64(&memcg
->memsw
, RES_LIMIT
);
1777 * If memsw is finite and limits the amount of swap space
1778 * available to this memcg, return that limit.
1780 limit
= min(limit
, memsw
);
1786 static void mem_cgroup_out_of_memory(struct mem_cgroup
*memcg
, gfp_t gfp_mask
,
1789 struct mem_cgroup
*iter
;
1790 unsigned long chosen_points
= 0;
1791 unsigned long totalpages
;
1792 unsigned int points
= 0;
1793 struct task_struct
*chosen
= NULL
;
1796 * If current has a pending SIGKILL or is exiting, then automatically
1797 * select it. The goal is to allow it to allocate so that it may
1798 * quickly exit and free its memory.
1800 if (fatal_signal_pending(current
) || current
->flags
& PF_EXITING
) {
1801 set_thread_flag(TIF_MEMDIE
);
1805 check_panic_on_oom(CONSTRAINT_MEMCG
, gfp_mask
, order
, NULL
);
1806 totalpages
= mem_cgroup_get_limit(memcg
) >> PAGE_SHIFT
? : 1;
1807 for_each_mem_cgroup_tree(iter
, memcg
) {
1808 struct cgroup
*cgroup
= iter
->css
.cgroup
;
1809 struct cgroup_iter it
;
1810 struct task_struct
*task
;
1812 cgroup_iter_start(cgroup
, &it
);
1813 while ((task
= cgroup_iter_next(cgroup
, &it
))) {
1814 switch (oom_scan_process_thread(task
, totalpages
, NULL
,
1816 case OOM_SCAN_SELECT
:
1818 put_task_struct(chosen
);
1820 chosen_points
= ULONG_MAX
;
1821 get_task_struct(chosen
);
1823 case OOM_SCAN_CONTINUE
:
1825 case OOM_SCAN_ABORT
:
1826 cgroup_iter_end(cgroup
, &it
);
1827 mem_cgroup_iter_break(memcg
, iter
);
1829 put_task_struct(chosen
);
1834 points
= oom_badness(task
, memcg
, NULL
, totalpages
);
1835 if (points
> chosen_points
) {
1837 put_task_struct(chosen
);
1839 chosen_points
= points
;
1840 get_task_struct(chosen
);
1843 cgroup_iter_end(cgroup
, &it
);
1848 points
= chosen_points
* 1000 / totalpages
;
1849 oom_kill_process(chosen
, gfp_mask
, order
, points
, totalpages
, memcg
,
1850 NULL
, "Memory cgroup out of memory");
1853 static unsigned long mem_cgroup_reclaim(struct mem_cgroup
*memcg
,
1855 unsigned long flags
)
1857 unsigned long total
= 0;
1858 bool noswap
= false;
1861 if (flags
& MEM_CGROUP_RECLAIM_NOSWAP
)
1863 if (!(flags
& MEM_CGROUP_RECLAIM_SHRINK
) && memcg
->memsw_is_minimum
)
1866 for (loop
= 0; loop
< MEM_CGROUP_MAX_RECLAIM_LOOPS
; loop
++) {
1868 drain_all_stock_async(memcg
);
1869 total
+= try_to_free_mem_cgroup_pages(memcg
, gfp_mask
, noswap
);
1871 * Allow limit shrinkers, which are triggered directly
1872 * by userspace, to catch signals and stop reclaim
1873 * after minimal progress, regardless of the margin.
1875 if (total
&& (flags
& MEM_CGROUP_RECLAIM_SHRINK
))
1877 if (mem_cgroup_margin(memcg
))
1880 * If nothing was reclaimed after two attempts, there
1881 * may be no reclaimable pages in this hierarchy.
1890 * test_mem_cgroup_node_reclaimable
1891 * @memcg: the target memcg
1892 * @nid: the node ID to be checked.
1893 * @noswap : specify true here if the user wants flle only information.
1895 * This function returns whether the specified memcg contains any
1896 * reclaimable pages on a node. Returns true if there are any reclaimable
1897 * pages in the node.
1899 static bool test_mem_cgroup_node_reclaimable(struct mem_cgroup
*memcg
,
1900 int nid
, bool noswap
)
1902 if (mem_cgroup_node_nr_lru_pages(memcg
, nid
, LRU_ALL_FILE
))
1904 if (noswap
|| !total_swap_pages
)
1906 if (mem_cgroup_node_nr_lru_pages(memcg
, nid
, LRU_ALL_ANON
))
1911 #if MAX_NUMNODES > 1
1914 * Always updating the nodemask is not very good - even if we have an empty
1915 * list or the wrong list here, we can start from some node and traverse all
1916 * nodes based on the zonelist. So update the list loosely once per 10 secs.
1919 static void mem_cgroup_may_update_nodemask(struct mem_cgroup
*memcg
)
1923 * numainfo_events > 0 means there was at least NUMAINFO_EVENTS_TARGET
1924 * pagein/pageout changes since the last update.
1926 if (!atomic_read(&memcg
->numainfo_events
))
1928 if (atomic_inc_return(&memcg
->numainfo_updating
) > 1)
1931 /* make a nodemask where this memcg uses memory from */
1932 memcg
->scan_nodes
= node_states
[N_MEMORY
];
1934 for_each_node_mask(nid
, node_states
[N_MEMORY
]) {
1936 if (!test_mem_cgroup_node_reclaimable(memcg
, nid
, false))
1937 node_clear(nid
, memcg
->scan_nodes
);
1940 atomic_set(&memcg
->numainfo_events
, 0);
1941 atomic_set(&memcg
->numainfo_updating
, 0);
1945 * Selecting a node where we start reclaim from. Because what we need is just
1946 * reducing usage counter, start from anywhere is O,K. Considering
1947 * memory reclaim from current node, there are pros. and cons.
1949 * Freeing memory from current node means freeing memory from a node which
1950 * we'll use or we've used. So, it may make LRU bad. And if several threads
1951 * hit limits, it will see a contention on a node. But freeing from remote
1952 * node means more costs for memory reclaim because of memory latency.
1954 * Now, we use round-robin. Better algorithm is welcomed.
1956 int mem_cgroup_select_victim_node(struct mem_cgroup
*memcg
)
1960 mem_cgroup_may_update_nodemask(memcg
);
1961 node
= memcg
->last_scanned_node
;
1963 node
= next_node(node
, memcg
->scan_nodes
);
1964 if (node
== MAX_NUMNODES
)
1965 node
= first_node(memcg
->scan_nodes
);
1967 * We call this when we hit limit, not when pages are added to LRU.
1968 * No LRU may hold pages because all pages are UNEVICTABLE or
1969 * memcg is too small and all pages are not on LRU. In that case,
1970 * we use curret node.
1972 if (unlikely(node
== MAX_NUMNODES
))
1973 node
= numa_node_id();
1975 memcg
->last_scanned_node
= node
;
1980 * Check all nodes whether it contains reclaimable pages or not.
1981 * For quick scan, we make use of scan_nodes. This will allow us to skip
1982 * unused nodes. But scan_nodes is lazily updated and may not cotain
1983 * enough new information. We need to do double check.
1985 static bool mem_cgroup_reclaimable(struct mem_cgroup
*memcg
, bool noswap
)
1990 * quick check...making use of scan_node.
1991 * We can skip unused nodes.
1993 if (!nodes_empty(memcg
->scan_nodes
)) {
1994 for (nid
= first_node(memcg
->scan_nodes
);
1996 nid
= next_node(nid
, memcg
->scan_nodes
)) {
1998 if (test_mem_cgroup_node_reclaimable(memcg
, nid
, noswap
))
2003 * Check rest of nodes.
2005 for_each_node_state(nid
, N_MEMORY
) {
2006 if (node_isset(nid
, memcg
->scan_nodes
))
2008 if (test_mem_cgroup_node_reclaimable(memcg
, nid
, noswap
))
2015 int mem_cgroup_select_victim_node(struct mem_cgroup
*memcg
)
2020 static bool mem_cgroup_reclaimable(struct mem_cgroup
*memcg
, bool noswap
)
2022 return test_mem_cgroup_node_reclaimable(memcg
, 0, noswap
);
2026 static int mem_cgroup_soft_reclaim(struct mem_cgroup
*root_memcg
,
2029 unsigned long *total_scanned
)
2031 struct mem_cgroup
*victim
= NULL
;
2034 unsigned long excess
;
2035 unsigned long nr_scanned
;
2036 struct mem_cgroup_reclaim_cookie reclaim
= {
2041 excess
= res_counter_soft_limit_excess(&root_memcg
->res
) >> PAGE_SHIFT
;
2044 victim
= mem_cgroup_iter(root_memcg
, victim
, &reclaim
);
2049 * If we have not been able to reclaim
2050 * anything, it might because there are
2051 * no reclaimable pages under this hierarchy
2056 * We want to do more targeted reclaim.
2057 * excess >> 2 is not to excessive so as to
2058 * reclaim too much, nor too less that we keep
2059 * coming back to reclaim from this cgroup
2061 if (total
>= (excess
>> 2) ||
2062 (loop
> MEM_CGROUP_MAX_RECLAIM_LOOPS
))
2067 if (!mem_cgroup_reclaimable(victim
, false))
2069 total
+= mem_cgroup_shrink_node_zone(victim
, gfp_mask
, false,
2071 *total_scanned
+= nr_scanned
;
2072 if (!res_counter_soft_limit_excess(&root_memcg
->res
))
2075 mem_cgroup_iter_break(root_memcg
, victim
);
2079 static DEFINE_SPINLOCK(memcg_oom_lock
);
2082 * Check OOM-Killer is already running under our hierarchy.
2083 * If someone is running, return false.
2085 static bool mem_cgroup_oom_trylock(struct mem_cgroup
*memcg
)
2087 struct mem_cgroup
*iter
, *failed
= NULL
;
2089 spin_lock(&memcg_oom_lock
);
2091 for_each_mem_cgroup_tree(iter
, memcg
) {
2092 if (iter
->oom_lock
) {
2094 * this subtree of our hierarchy is already locked
2095 * so we cannot give a lock.
2098 mem_cgroup_iter_break(memcg
, iter
);
2101 iter
->oom_lock
= true;
2106 * OK, we failed to lock the whole subtree so we have
2107 * to clean up what we set up to the failing subtree
2109 for_each_mem_cgroup_tree(iter
, memcg
) {
2110 if (iter
== failed
) {
2111 mem_cgroup_iter_break(memcg
, iter
);
2114 iter
->oom_lock
= false;
2118 spin_unlock(&memcg_oom_lock
);
2123 static void mem_cgroup_oom_unlock(struct mem_cgroup
*memcg
)
2125 struct mem_cgroup
*iter
;
2127 spin_lock(&memcg_oom_lock
);
2128 for_each_mem_cgroup_tree(iter
, memcg
)
2129 iter
->oom_lock
= false;
2130 spin_unlock(&memcg_oom_lock
);
2133 static void mem_cgroup_mark_under_oom(struct mem_cgroup
*memcg
)
2135 struct mem_cgroup
*iter
;
2137 for_each_mem_cgroup_tree(iter
, memcg
)
2138 atomic_inc(&iter
->under_oom
);
2141 static void mem_cgroup_unmark_under_oom(struct mem_cgroup
*memcg
)
2143 struct mem_cgroup
*iter
;
2146 * When a new child is created while the hierarchy is under oom,
2147 * mem_cgroup_oom_lock() may not be called. We have to use
2148 * atomic_add_unless() here.
2150 for_each_mem_cgroup_tree(iter
, memcg
)
2151 atomic_add_unless(&iter
->under_oom
, -1, 0);
2154 static DECLARE_WAIT_QUEUE_HEAD(memcg_oom_waitq
);
2156 struct oom_wait_info
{
2157 struct mem_cgroup
*memcg
;
2161 static int memcg_oom_wake_function(wait_queue_t
*wait
,
2162 unsigned mode
, int sync
, void *arg
)
2164 struct mem_cgroup
*wake_memcg
= (struct mem_cgroup
*)arg
;
2165 struct mem_cgroup
*oom_wait_memcg
;
2166 struct oom_wait_info
*oom_wait_info
;
2168 oom_wait_info
= container_of(wait
, struct oom_wait_info
, wait
);
2169 oom_wait_memcg
= oom_wait_info
->memcg
;
2172 * Both of oom_wait_info->memcg and wake_memcg are stable under us.
2173 * Then we can use css_is_ancestor without taking care of RCU.
2175 if (!mem_cgroup_same_or_subtree(oom_wait_memcg
, wake_memcg
)
2176 && !mem_cgroup_same_or_subtree(wake_memcg
, oom_wait_memcg
))
2178 return autoremove_wake_function(wait
, mode
, sync
, arg
);
2181 static void memcg_wakeup_oom(struct mem_cgroup
*memcg
)
2183 atomic_inc(&memcg
->oom_wakeups
);
2184 /* for filtering, pass "memcg" as argument. */
2185 __wake_up(&memcg_oom_waitq
, TASK_NORMAL
, 0, memcg
);
2188 static void memcg_oom_recover(struct mem_cgroup
*memcg
)
2190 if (memcg
&& atomic_read(&memcg
->under_oom
))
2191 memcg_wakeup_oom(memcg
);
2194 static void mem_cgroup_oom(struct mem_cgroup
*memcg
, gfp_t mask
, int order
)
2196 if (!current
->memcg_oom
.may_oom
)
2199 * We are in the middle of the charge context here, so we
2200 * don't want to block when potentially sitting on a callstack
2201 * that holds all kinds of filesystem and mm locks.
2203 * Also, the caller may handle a failed allocation gracefully
2204 * (like optional page cache readahead) and so an OOM killer
2205 * invocation might not even be necessary.
2207 * That's why we don't do anything here except remember the
2208 * OOM context and then deal with it at the end of the page
2209 * fault when the stack is unwound, the locks are released,
2210 * and when we know whether the fault was overall successful.
2212 css_get(&memcg
->css
);
2213 current
->memcg_oom
.memcg
= memcg
;
2214 current
->memcg_oom
.gfp_mask
= mask
;
2215 current
->memcg_oom
.order
= order
;
2219 * mem_cgroup_oom_synchronize - complete memcg OOM handling
2220 * @handle: actually kill/wait or just clean up the OOM state
2222 * This has to be called at the end of a page fault if the memcg OOM
2223 * handler was enabled.
2225 * Memcg supports userspace OOM handling where failed allocations must
2226 * sleep on a waitqueue until the userspace task resolves the
2227 * situation. Sleeping directly in the charge context with all kinds
2228 * of locks held is not a good idea, instead we remember an OOM state
2229 * in the task and mem_cgroup_oom_synchronize() has to be called at
2230 * the end of the page fault to complete the OOM handling.
2232 * Returns %true if an ongoing memcg OOM situation was detected and
2233 * completed, %false otherwise.
2235 bool mem_cgroup_oom_synchronize(bool handle
)
2237 struct mem_cgroup
*memcg
= current
->memcg_oom
.memcg
;
2238 struct oom_wait_info owait
;
2241 /* OOM is global, do not handle */
2248 owait
.memcg
= memcg
;
2249 owait
.wait
.flags
= 0;
2250 owait
.wait
.func
= memcg_oom_wake_function
;
2251 owait
.wait
.private = current
;
2252 INIT_LIST_HEAD(&owait
.wait
.task_list
);
2254 prepare_to_wait(&memcg_oom_waitq
, &owait
.wait
, TASK_KILLABLE
);
2255 mem_cgroup_mark_under_oom(memcg
);
2257 locked
= mem_cgroup_oom_trylock(memcg
);
2260 mem_cgroup_oom_notify(memcg
);
2262 if (locked
&& !memcg
->oom_kill_disable
) {
2263 mem_cgroup_unmark_under_oom(memcg
);
2264 finish_wait(&memcg_oom_waitq
, &owait
.wait
);
2265 mem_cgroup_out_of_memory(memcg
, current
->memcg_oom
.gfp_mask
,
2266 current
->memcg_oom
.order
);
2269 mem_cgroup_unmark_under_oom(memcg
);
2270 finish_wait(&memcg_oom_waitq
, &owait
.wait
);
2274 mem_cgroup_oom_unlock(memcg
);
2276 * There is no guarantee that an OOM-lock contender
2277 * sees the wakeups triggered by the OOM kill
2278 * uncharges. Wake any sleepers explicitely.
2280 memcg_oom_recover(memcg
);
2283 current
->memcg_oom
.memcg
= NULL
;
2284 css_put(&memcg
->css
);
2289 * Currently used to update mapped file statistics, but the routine can be
2290 * generalized to update other statistics as well.
2292 * Notes: Race condition
2294 * We usually use page_cgroup_lock() for accessing page_cgroup member but
2295 * it tends to be costly. But considering some conditions, we doesn't need
2296 * to do so _always_.
2298 * Considering "charge", lock_page_cgroup() is not required because all
2299 * file-stat operations happen after a page is attached to radix-tree. There
2300 * are no race with "charge".
2302 * Considering "uncharge", we know that memcg doesn't clear pc->mem_cgroup
2303 * at "uncharge" intentionally. So, we always see valid pc->mem_cgroup even
2304 * if there are race with "uncharge". Statistics itself is properly handled
2307 * Considering "move", this is an only case we see a race. To make the race
2308 * small, we check mm->moving_account and detect there are possibility of race
2309 * If there is, we take a lock.
2312 void __mem_cgroup_begin_update_page_stat(struct page
*page
,
2313 bool *locked
, unsigned long *flags
)
2315 struct mem_cgroup
*memcg
;
2316 struct page_cgroup
*pc
;
2318 pc
= lookup_page_cgroup(page
);
2320 memcg
= pc
->mem_cgroup
;
2321 if (unlikely(!memcg
|| !PageCgroupUsed(pc
)))
2324 * If this memory cgroup is not under account moving, we don't
2325 * need to take move_lock_mem_cgroup(). Because we already hold
2326 * rcu_read_lock(), any calls to move_account will be delayed until
2327 * rcu_read_unlock() if mem_cgroup_stolen() == true.
2329 if (!mem_cgroup_stolen(memcg
))
2332 move_lock_mem_cgroup(memcg
, flags
);
2333 if (memcg
!= pc
->mem_cgroup
|| !PageCgroupUsed(pc
)) {
2334 move_unlock_mem_cgroup(memcg
, flags
);
2340 void __mem_cgroup_end_update_page_stat(struct page
*page
, unsigned long *flags
)
2342 struct page_cgroup
*pc
= lookup_page_cgroup(page
);
2345 * It's guaranteed that pc->mem_cgroup never changes while
2346 * lock is held because a routine modifies pc->mem_cgroup
2347 * should take move_lock_mem_cgroup().
2349 move_unlock_mem_cgroup(pc
->mem_cgroup
, flags
);
2352 void mem_cgroup_update_page_stat(struct page
*page
,
2353 enum mem_cgroup_page_stat_item idx
, int val
)
2355 struct mem_cgroup
*memcg
;
2356 struct page_cgroup
*pc
= lookup_page_cgroup(page
);
2357 unsigned long uninitialized_var(flags
);
2359 if (mem_cgroup_disabled())
2362 memcg
= pc
->mem_cgroup
;
2363 if (unlikely(!memcg
|| !PageCgroupUsed(pc
)))
2367 case MEMCG_NR_FILE_MAPPED
:
2368 idx
= MEM_CGROUP_STAT_FILE_MAPPED
;
2374 this_cpu_add(memcg
->stat
->count
[idx
], val
);
2378 * size of first charge trial. "32" comes from vmscan.c's magic value.
2379 * TODO: maybe necessary to use big numbers in big irons.
2381 #define CHARGE_BATCH 32U
2382 struct memcg_stock_pcp
{
2383 struct mem_cgroup
*cached
; /* this never be root cgroup */
2384 unsigned int nr_pages
;
2385 struct work_struct work
;
2386 unsigned long flags
;
2387 #define FLUSHING_CACHED_CHARGE 0
2389 static DEFINE_PER_CPU(struct memcg_stock_pcp
, memcg_stock
);
2390 static DEFINE_MUTEX(percpu_charge_mutex
);
2393 * consume_stock: Try to consume stocked charge on this cpu.
2394 * @memcg: memcg to consume from.
2395 * @nr_pages: how many pages to charge.
2397 * The charges will only happen if @memcg matches the current cpu's memcg
2398 * stock, and at least @nr_pages are available in that stock. Failure to
2399 * service an allocation will refill the stock.
2401 * returns true if successful, false otherwise.
2403 static bool consume_stock(struct mem_cgroup
*memcg
, unsigned int nr_pages
)
2405 struct memcg_stock_pcp
*stock
;
2408 if (nr_pages
> CHARGE_BATCH
)
2411 stock
= &get_cpu_var(memcg_stock
);
2412 if (memcg
== stock
->cached
&& stock
->nr_pages
>= nr_pages
)
2413 stock
->nr_pages
-= nr_pages
;
2414 else /* need to call res_counter_charge */
2416 put_cpu_var(memcg_stock
);
2421 * Returns stocks cached in percpu to res_counter and reset cached information.
2423 static void drain_stock(struct memcg_stock_pcp
*stock
)
2425 struct mem_cgroup
*old
= stock
->cached
;
2427 if (stock
->nr_pages
) {
2428 unsigned long bytes
= stock
->nr_pages
* PAGE_SIZE
;
2430 res_counter_uncharge(&old
->res
, bytes
);
2431 if (do_swap_account
)
2432 res_counter_uncharge(&old
->memsw
, bytes
);
2433 stock
->nr_pages
= 0;
2435 stock
->cached
= NULL
;
2439 * This must be called under preempt disabled or must be called by
2440 * a thread which is pinned to local cpu.
2442 static void drain_local_stock(struct work_struct
*dummy
)
2444 struct memcg_stock_pcp
*stock
= &__get_cpu_var(memcg_stock
);
2446 clear_bit(FLUSHING_CACHED_CHARGE
, &stock
->flags
);
2449 static void __init
memcg_stock_init(void)
2453 for_each_possible_cpu(cpu
) {
2454 struct memcg_stock_pcp
*stock
=
2455 &per_cpu(memcg_stock
, cpu
);
2456 INIT_WORK(&stock
->work
, drain_local_stock
);
2461 * Cache charges(val) which is from res_counter, to local per_cpu area.
2462 * This will be consumed by consume_stock() function, later.
2464 static void refill_stock(struct mem_cgroup
*memcg
, unsigned int nr_pages
)
2466 struct memcg_stock_pcp
*stock
= &get_cpu_var(memcg_stock
);
2468 if (stock
->cached
!= memcg
) { /* reset if necessary */
2470 stock
->cached
= memcg
;
2472 stock
->nr_pages
+= nr_pages
;
2473 put_cpu_var(memcg_stock
);
2477 * Drains all per-CPU charge caches for given root_memcg resp. subtree
2478 * of the hierarchy under it. sync flag says whether we should block
2479 * until the work is done.
2481 static void drain_all_stock(struct mem_cgroup
*root_memcg
, bool sync
)
2485 /* Notify other cpus that system-wide "drain" is running */
2488 for_each_online_cpu(cpu
) {
2489 struct memcg_stock_pcp
*stock
= &per_cpu(memcg_stock
, cpu
);
2490 struct mem_cgroup
*memcg
;
2492 memcg
= stock
->cached
;
2493 if (!memcg
|| !stock
->nr_pages
)
2495 if (!mem_cgroup_same_or_subtree(root_memcg
, memcg
))
2497 if (!test_and_set_bit(FLUSHING_CACHED_CHARGE
, &stock
->flags
)) {
2499 drain_local_stock(&stock
->work
);
2501 schedule_work_on(cpu
, &stock
->work
);
2509 for_each_online_cpu(cpu
) {
2510 struct memcg_stock_pcp
*stock
= &per_cpu(memcg_stock
, cpu
);
2511 if (test_bit(FLUSHING_CACHED_CHARGE
, &stock
->flags
))
2512 flush_work(&stock
->work
);
2519 * Tries to drain stocked charges in other cpus. This function is asynchronous
2520 * and just put a work per cpu for draining localy on each cpu. Caller can
2521 * expects some charges will be back to res_counter later but cannot wait for
2524 static void drain_all_stock_async(struct mem_cgroup
*root_memcg
)
2527 * If someone calls draining, avoid adding more kworker runs.
2529 if (!mutex_trylock(&percpu_charge_mutex
))
2531 drain_all_stock(root_memcg
, false);
2532 mutex_unlock(&percpu_charge_mutex
);
2535 /* This is a synchronous drain interface. */
2536 static void drain_all_stock_sync(struct mem_cgroup
*root_memcg
)
2538 /* called when force_empty is called */
2539 mutex_lock(&percpu_charge_mutex
);
2540 drain_all_stock(root_memcg
, true);
2541 mutex_unlock(&percpu_charge_mutex
);
2545 * This function drains percpu counter value from DEAD cpu and
2546 * move it to local cpu. Note that this function can be preempted.
2548 static void mem_cgroup_drain_pcp_counter(struct mem_cgroup
*memcg
, int cpu
)
2552 spin_lock(&memcg
->pcp_counter_lock
);
2553 for (i
= 0; i
< MEM_CGROUP_STAT_NSTATS
; i
++) {
2554 long x
= per_cpu(memcg
->stat
->count
[i
], cpu
);
2556 per_cpu(memcg
->stat
->count
[i
], cpu
) = 0;
2557 memcg
->nocpu_base
.count
[i
] += x
;
2559 for (i
= 0; i
< MEM_CGROUP_EVENTS_NSTATS
; i
++) {
2560 unsigned long x
= per_cpu(memcg
->stat
->events
[i
], cpu
);
2562 per_cpu(memcg
->stat
->events
[i
], cpu
) = 0;
2563 memcg
->nocpu_base
.events
[i
] += x
;
2565 spin_unlock(&memcg
->pcp_counter_lock
);
2568 static int __cpuinit
memcg_cpu_hotplug_callback(struct notifier_block
*nb
,
2569 unsigned long action
,
2572 int cpu
= (unsigned long)hcpu
;
2573 struct memcg_stock_pcp
*stock
;
2574 struct mem_cgroup
*iter
;
2576 if (action
== CPU_ONLINE
)
2579 if (action
!= CPU_DEAD
&& action
!= CPU_DEAD_FROZEN
)
2582 for_each_mem_cgroup(iter
)
2583 mem_cgroup_drain_pcp_counter(iter
, cpu
);
2585 stock
= &per_cpu(memcg_stock
, cpu
);
2591 /* See __mem_cgroup_try_charge() for details */
2593 CHARGE_OK
, /* success */
2594 CHARGE_RETRY
, /* need to retry but retry is not bad */
2595 CHARGE_NOMEM
, /* we can't do more. return -ENOMEM */
2596 CHARGE_WOULDBLOCK
, /* GFP_WAIT wasn't set and no enough res. */
2599 static int mem_cgroup_do_charge(struct mem_cgroup
*memcg
, gfp_t gfp_mask
,
2600 unsigned int nr_pages
, unsigned int min_pages
,
2603 unsigned long csize
= nr_pages
* PAGE_SIZE
;
2604 struct mem_cgroup
*mem_over_limit
;
2605 struct res_counter
*fail_res
;
2606 unsigned long flags
= 0;
2609 ret
= res_counter_charge(&memcg
->res
, csize
, &fail_res
);
2612 if (!do_swap_account
)
2614 ret
= res_counter_charge(&memcg
->memsw
, csize
, &fail_res
);
2618 res_counter_uncharge(&memcg
->res
, csize
);
2619 mem_over_limit
= mem_cgroup_from_res_counter(fail_res
, memsw
);
2620 flags
|= MEM_CGROUP_RECLAIM_NOSWAP
;
2622 mem_over_limit
= mem_cgroup_from_res_counter(fail_res
, res
);
2624 * Never reclaim on behalf of optional batching, retry with a
2625 * single page instead.
2627 if (nr_pages
> min_pages
)
2628 return CHARGE_RETRY
;
2630 if (!(gfp_mask
& __GFP_WAIT
))
2631 return CHARGE_WOULDBLOCK
;
2633 if (gfp_mask
& __GFP_NORETRY
)
2634 return CHARGE_NOMEM
;
2636 ret
= mem_cgroup_reclaim(mem_over_limit
, gfp_mask
, flags
);
2637 if (mem_cgroup_margin(mem_over_limit
) >= nr_pages
)
2638 return CHARGE_RETRY
;
2640 * Even though the limit is exceeded at this point, reclaim
2641 * may have been able to free some pages. Retry the charge
2642 * before killing the task.
2644 * Only for regular pages, though: huge pages are rather
2645 * unlikely to succeed so close to the limit, and we fall back
2646 * to regular pages anyway in case of failure.
2648 if (nr_pages
<= (1 << PAGE_ALLOC_COSTLY_ORDER
) && ret
)
2649 return CHARGE_RETRY
;
2652 * At task move, charge accounts can be doubly counted. So, it's
2653 * better to wait until the end of task_move if something is going on.
2655 if (mem_cgroup_wait_acct_move(mem_over_limit
))
2656 return CHARGE_RETRY
;
2659 mem_cgroup_oom(mem_over_limit
, gfp_mask
, get_order(csize
));
2661 return CHARGE_NOMEM
;
2665 * __mem_cgroup_try_charge() does
2666 * 1. detect memcg to be charged against from passed *mm and *ptr,
2667 * 2. update res_counter
2668 * 3. call memory reclaim if necessary.
2670 * In some special case, if the task is fatal, fatal_signal_pending() or
2671 * has TIF_MEMDIE, this function returns -EINTR while writing root_mem_cgroup
2672 * to *ptr. There are two reasons for this. 1: fatal threads should quit as soon
2673 * as possible without any hazards. 2: all pages should have a valid
2674 * pc->mem_cgroup. If mm is NULL and the caller doesn't pass a valid memcg
2675 * pointer, that is treated as a charge to root_mem_cgroup.
2677 * So __mem_cgroup_try_charge() will return
2678 * 0 ... on success, filling *ptr with a valid memcg pointer.
2679 * -ENOMEM ... charge failure because of resource limits.
2680 * -EINTR ... if thread is fatal. *ptr is filled with root_mem_cgroup.
2682 * Unlike the exported interface, an "oom" parameter is added. if oom==true,
2683 * the oom-killer can be invoked.
2685 static int __mem_cgroup_try_charge(struct mm_struct
*mm
,
2687 unsigned int nr_pages
,
2688 struct mem_cgroup
**ptr
,
2691 unsigned int batch
= max(CHARGE_BATCH
, nr_pages
);
2692 int nr_oom_retries
= MEM_CGROUP_RECLAIM_RETRIES
;
2693 struct mem_cgroup
*memcg
= NULL
;
2697 * Unlike gloval-vm's OOM-kill, we're not in memory shortage
2698 * in system level. So, allow to go ahead dying process in addition to
2701 if (unlikely(test_thread_flag(TIF_MEMDIE
)
2702 || fatal_signal_pending(current
)))
2705 if (unlikely(task_in_memcg_oom(current
)))
2709 * We always charge the cgroup the mm_struct belongs to.
2710 * The mm_struct's mem_cgroup changes on task migration if the
2711 * thread group leader migrates. It's possible that mm is not
2712 * set, if so charge the root memcg (happens for pagecache usage).
2715 *ptr
= root_mem_cgroup
;
2717 if (*ptr
) { /* css should be a valid one */
2719 if (mem_cgroup_is_root(memcg
))
2721 if (consume_stock(memcg
, nr_pages
))
2723 css_get(&memcg
->css
);
2725 struct task_struct
*p
;
2728 p
= rcu_dereference(mm
->owner
);
2730 * Because we don't have task_lock(), "p" can exit.
2731 * In that case, "memcg" can point to root or p can be NULL with
2732 * race with swapoff. Then, we have small risk of mis-accouning.
2733 * But such kind of mis-account by race always happens because
2734 * we don't have cgroup_mutex(). It's overkill and we allo that
2736 * (*) swapoff at el will charge against mm-struct not against
2737 * task-struct. So, mm->owner can be NULL.
2739 memcg
= mem_cgroup_from_task(p
);
2741 memcg
= root_mem_cgroup
;
2742 if (mem_cgroup_is_root(memcg
)) {
2746 if (consume_stock(memcg
, nr_pages
)) {
2748 * It seems dagerous to access memcg without css_get().
2749 * But considering how consume_stok works, it's not
2750 * necessary. If consume_stock success, some charges
2751 * from this memcg are cached on this cpu. So, we
2752 * don't need to call css_get()/css_tryget() before
2753 * calling consume_stock().
2758 /* after here, we may be blocked. we need to get refcnt */
2759 if (!css_tryget(&memcg
->css
)) {
2767 bool invoke_oom
= oom
&& !nr_oom_retries
;
2769 /* If killed, bypass charge */
2770 if (fatal_signal_pending(current
)) {
2771 css_put(&memcg
->css
);
2775 ret
= mem_cgroup_do_charge(memcg
, gfp_mask
, batch
,
2776 nr_pages
, invoke_oom
);
2780 case CHARGE_RETRY
: /* not in OOM situation but retry */
2782 css_put(&memcg
->css
);
2785 case CHARGE_WOULDBLOCK
: /* !__GFP_WAIT */
2786 css_put(&memcg
->css
);
2788 case CHARGE_NOMEM
: /* OOM routine works */
2789 if (!oom
|| invoke_oom
) {
2790 css_put(&memcg
->css
);
2796 } while (ret
!= CHARGE_OK
);
2798 if (batch
> nr_pages
)
2799 refill_stock(memcg
, batch
- nr_pages
);
2800 css_put(&memcg
->css
);
2808 *ptr
= root_mem_cgroup
;
2813 * Somemtimes we have to undo a charge we got by try_charge().
2814 * This function is for that and do uncharge, put css's refcnt.
2815 * gotten by try_charge().
2817 static void __mem_cgroup_cancel_charge(struct mem_cgroup
*memcg
,
2818 unsigned int nr_pages
)
2820 if (!mem_cgroup_is_root(memcg
)) {
2821 unsigned long bytes
= nr_pages
* PAGE_SIZE
;
2823 res_counter_uncharge(&memcg
->res
, bytes
);
2824 if (do_swap_account
)
2825 res_counter_uncharge(&memcg
->memsw
, bytes
);
2830 * Cancel chrages in this cgroup....doesn't propagate to parent cgroup.
2831 * This is useful when moving usage to parent cgroup.
2833 static void __mem_cgroup_cancel_local_charge(struct mem_cgroup
*memcg
,
2834 unsigned int nr_pages
)
2836 unsigned long bytes
= nr_pages
* PAGE_SIZE
;
2838 if (mem_cgroup_is_root(memcg
))
2841 res_counter_uncharge_until(&memcg
->res
, memcg
->res
.parent
, bytes
);
2842 if (do_swap_account
)
2843 res_counter_uncharge_until(&memcg
->memsw
,
2844 memcg
->memsw
.parent
, bytes
);
2848 * A helper function to get mem_cgroup from ID. must be called under
2849 * rcu_read_lock(). The caller is responsible for calling css_tryget if
2850 * the mem_cgroup is used for charging. (dropping refcnt from swap can be
2851 * called against removed memcg.)
2853 static struct mem_cgroup
*mem_cgroup_lookup(unsigned short id
)
2855 struct cgroup_subsys_state
*css
;
2857 /* ID 0 is unused ID */
2860 css
= css_lookup(&mem_cgroup_subsys
, id
);
2863 return mem_cgroup_from_css(css
);
2866 struct mem_cgroup
*try_get_mem_cgroup_from_page(struct page
*page
)
2868 struct mem_cgroup
*memcg
= NULL
;
2869 struct page_cgroup
*pc
;
2873 VM_BUG_ON(!PageLocked(page
));
2875 pc
= lookup_page_cgroup(page
);
2876 lock_page_cgroup(pc
);
2877 if (PageCgroupUsed(pc
)) {
2878 memcg
= pc
->mem_cgroup
;
2879 if (memcg
&& !css_tryget(&memcg
->css
))
2881 } else if (PageSwapCache(page
)) {
2882 ent
.val
= page_private(page
);
2883 id
= lookup_swap_cgroup_id(ent
);
2885 memcg
= mem_cgroup_lookup(id
);
2886 if (memcg
&& !css_tryget(&memcg
->css
))
2890 unlock_page_cgroup(pc
);
2894 static void __mem_cgroup_commit_charge(struct mem_cgroup
*memcg
,
2896 unsigned int nr_pages
,
2897 enum charge_type ctype
,
2900 struct page_cgroup
*pc
= lookup_page_cgroup(page
);
2901 struct zone
*uninitialized_var(zone
);
2902 struct lruvec
*lruvec
;
2903 bool was_on_lru
= false;
2906 lock_page_cgroup(pc
);
2907 VM_BUG_ON(PageCgroupUsed(pc
));
2909 * we don't need page_cgroup_lock about tail pages, becase they are not
2910 * accessed by any other context at this point.
2914 * In some cases, SwapCache and FUSE(splice_buf->radixtree), the page
2915 * may already be on some other mem_cgroup's LRU. Take care of it.
2918 zone
= page_zone(page
);
2919 spin_lock_irq(&zone
->lru_lock
);
2920 if (PageLRU(page
)) {
2921 lruvec
= mem_cgroup_zone_lruvec(zone
, pc
->mem_cgroup
);
2923 del_page_from_lru_list(page
, lruvec
, page_lru(page
));
2928 pc
->mem_cgroup
= memcg
;
2930 * We access a page_cgroup asynchronously without lock_page_cgroup().
2931 * Especially when a page_cgroup is taken from a page, pc->mem_cgroup
2932 * is accessed after testing USED bit. To make pc->mem_cgroup visible
2933 * before USED bit, we need memory barrier here.
2934 * See mem_cgroup_add_lru_list(), etc.
2937 SetPageCgroupUsed(pc
);
2941 lruvec
= mem_cgroup_zone_lruvec(zone
, pc
->mem_cgroup
);
2942 VM_BUG_ON(PageLRU(page
));
2944 add_page_to_lru_list(page
, lruvec
, page_lru(page
));
2946 spin_unlock_irq(&zone
->lru_lock
);
2949 if (ctype
== MEM_CGROUP_CHARGE_TYPE_ANON
)
2954 mem_cgroup_charge_statistics(memcg
, page
, anon
, nr_pages
);
2955 unlock_page_cgroup(pc
);
2958 * "charge_statistics" updated event counter. Then, check it.
2959 * Insert ancestor (and ancestor's ancestors), to softlimit RB-tree.
2960 * if they exceeds softlimit.
2962 memcg_check_events(memcg
, page
);
2965 static DEFINE_MUTEX(set_limit_mutex
);
2967 #ifdef CONFIG_MEMCG_KMEM
2968 static inline bool memcg_can_account_kmem(struct mem_cgroup
*memcg
)
2970 return !mem_cgroup_disabled() && !mem_cgroup_is_root(memcg
) &&
2971 (memcg
->kmem_account_flags
& KMEM_ACCOUNTED_MASK
);
2975 * This is a bit cumbersome, but it is rarely used and avoids a backpointer
2976 * in the memcg_cache_params struct.
2978 static struct kmem_cache
*memcg_params_to_cache(struct memcg_cache_params
*p
)
2980 struct kmem_cache
*cachep
;
2982 VM_BUG_ON(p
->is_root_cache
);
2983 cachep
= p
->root_cache
;
2984 return cachep
->memcg_params
->memcg_caches
[memcg_cache_id(p
->memcg
)];
2987 #ifdef CONFIG_SLABINFO
2988 static int mem_cgroup_slabinfo_read(struct cgroup
*cont
, struct cftype
*cft
,
2991 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cont
);
2992 struct memcg_cache_params
*params
;
2994 if (!memcg_can_account_kmem(memcg
))
2997 print_slabinfo_header(m
);
2999 mutex_lock(&memcg
->slab_caches_mutex
);
3000 list_for_each_entry(params
, &memcg
->memcg_slab_caches
, list
)
3001 cache_show(memcg_params_to_cache(params
), m
);
3002 mutex_unlock(&memcg
->slab_caches_mutex
);
3008 static int memcg_charge_kmem(struct mem_cgroup
*memcg
, gfp_t gfp
, u64 size
)
3010 struct res_counter
*fail_res
;
3011 struct mem_cgroup
*_memcg
;
3015 ret
= res_counter_charge(&memcg
->kmem
, size
, &fail_res
);
3020 * Conditions under which we can wait for the oom_killer. Those are
3021 * the same conditions tested by the core page allocator
3023 may_oom
= (gfp
& __GFP_FS
) && !(gfp
& __GFP_NORETRY
);
3026 ret
= __mem_cgroup_try_charge(NULL
, gfp
, size
>> PAGE_SHIFT
,
3029 if (ret
== -EINTR
) {
3031 * __mem_cgroup_try_charge() chosed to bypass to root due to
3032 * OOM kill or fatal signal. Since our only options are to
3033 * either fail the allocation or charge it to this cgroup, do
3034 * it as a temporary condition. But we can't fail. From a
3035 * kmem/slab perspective, the cache has already been selected,
3036 * by mem_cgroup_kmem_get_cache(), so it is too late to change
3039 * This condition will only trigger if the task entered
3040 * memcg_charge_kmem in a sane state, but was OOM-killed during
3041 * __mem_cgroup_try_charge() above. Tasks that were already
3042 * dying when the allocation triggers should have been already
3043 * directed to the root cgroup in memcontrol.h
3045 res_counter_charge_nofail(&memcg
->res
, size
, &fail_res
);
3046 if (do_swap_account
)
3047 res_counter_charge_nofail(&memcg
->memsw
, size
,
3051 res_counter_uncharge(&memcg
->kmem
, size
);
3056 static void memcg_uncharge_kmem(struct mem_cgroup
*memcg
, u64 size
)
3058 res_counter_uncharge(&memcg
->res
, size
);
3059 if (do_swap_account
)
3060 res_counter_uncharge(&memcg
->memsw
, size
);
3063 if (res_counter_uncharge(&memcg
->kmem
, size
))
3066 if (memcg_kmem_test_and_clear_dead(memcg
))
3067 mem_cgroup_put(memcg
);
3070 void memcg_cache_list_add(struct mem_cgroup
*memcg
, struct kmem_cache
*cachep
)
3075 mutex_lock(&memcg
->slab_caches_mutex
);
3076 list_add(&cachep
->memcg_params
->list
, &memcg
->memcg_slab_caches
);
3077 mutex_unlock(&memcg
->slab_caches_mutex
);
3081 * helper for acessing a memcg's index. It will be used as an index in the
3082 * child cache array in kmem_cache, and also to derive its name. This function
3083 * will return -1 when this is not a kmem-limited memcg.
3085 int memcg_cache_id(struct mem_cgroup
*memcg
)
3087 return memcg
? memcg
->kmemcg_id
: -1;
3091 * This ends up being protected by the set_limit mutex, during normal
3092 * operation, because that is its main call site.
3094 * But when we create a new cache, we can call this as well if its parent
3095 * is kmem-limited. That will have to hold set_limit_mutex as well.
3097 int memcg_update_cache_sizes(struct mem_cgroup
*memcg
)
3101 num
= ida_simple_get(&kmem_limited_groups
,
3102 0, MEMCG_CACHES_MAX_SIZE
, GFP_KERNEL
);
3106 * After this point, kmem_accounted (that we test atomically in
3107 * the beginning of this conditional), is no longer 0. This
3108 * guarantees only one process will set the following boolean
3109 * to true. We don't need test_and_set because we're protected
3110 * by the set_limit_mutex anyway.
3112 memcg_kmem_set_activated(memcg
);
3114 ret
= memcg_update_all_caches(num
+1);
3116 ida_simple_remove(&kmem_limited_groups
, num
);
3117 memcg_kmem_clear_activated(memcg
);
3121 memcg
->kmemcg_id
= num
;
3122 INIT_LIST_HEAD(&memcg
->memcg_slab_caches
);
3123 mutex_init(&memcg
->slab_caches_mutex
);
3127 static size_t memcg_caches_array_size(int num_groups
)
3130 if (num_groups
<= 0)
3133 size
= 2 * num_groups
;
3134 if (size
< MEMCG_CACHES_MIN_SIZE
)
3135 size
= MEMCG_CACHES_MIN_SIZE
;
3136 else if (size
> MEMCG_CACHES_MAX_SIZE
)
3137 size
= MEMCG_CACHES_MAX_SIZE
;
3143 * We should update the current array size iff all caches updates succeed. This
3144 * can only be done from the slab side. The slab mutex needs to be held when
3147 void memcg_update_array_size(int num
)
3149 if (num
> memcg_limited_groups_array_size
)
3150 memcg_limited_groups_array_size
= memcg_caches_array_size(num
);
3153 static void kmem_cache_destroy_work_func(struct work_struct
*w
);
3155 int memcg_update_cache_size(struct kmem_cache
*s
, int num_groups
)
3157 struct memcg_cache_params
*cur_params
= s
->memcg_params
;
3159 VM_BUG_ON(s
->memcg_params
&& !s
->memcg_params
->is_root_cache
);
3161 if (num_groups
> memcg_limited_groups_array_size
) {
3163 ssize_t size
= memcg_caches_array_size(num_groups
);
3165 size
*= sizeof(void *);
3166 size
+= sizeof(struct memcg_cache_params
);
3168 s
->memcg_params
= kzalloc(size
, GFP_KERNEL
);
3169 if (!s
->memcg_params
) {
3170 s
->memcg_params
= cur_params
;
3174 s
->memcg_params
->is_root_cache
= true;
3177 * There is the chance it will be bigger than
3178 * memcg_limited_groups_array_size, if we failed an allocation
3179 * in a cache, in which case all caches updated before it, will
3180 * have a bigger array.
3182 * But if that is the case, the data after
3183 * memcg_limited_groups_array_size is certainly unused
3185 for (i
= 0; i
< memcg_limited_groups_array_size
; i
++) {
3186 if (!cur_params
->memcg_caches
[i
])
3188 s
->memcg_params
->memcg_caches
[i
] =
3189 cur_params
->memcg_caches
[i
];
3193 * Ideally, we would wait until all caches succeed, and only
3194 * then free the old one. But this is not worth the extra
3195 * pointer per-cache we'd have to have for this.
3197 * It is not a big deal if some caches are left with a size
3198 * bigger than the others. And all updates will reset this
3206 int memcg_register_cache(struct mem_cgroup
*memcg
, struct kmem_cache
*s
,
3207 struct kmem_cache
*root_cache
)
3209 size_t size
= sizeof(struct memcg_cache_params
);
3211 if (!memcg_kmem_enabled())
3215 size
+= memcg_limited_groups_array_size
* sizeof(void *);
3217 s
->memcg_params
= kzalloc(size
, GFP_KERNEL
);
3218 if (!s
->memcg_params
)
3222 s
->memcg_params
->memcg
= memcg
;
3223 s
->memcg_params
->root_cache
= root_cache
;
3224 INIT_WORK(&s
->memcg_params
->destroy
,
3225 kmem_cache_destroy_work_func
);
3227 s
->memcg_params
->is_root_cache
= true;
3232 void memcg_release_cache(struct kmem_cache
*s
)
3234 struct kmem_cache
*root
;
3235 struct mem_cgroup
*memcg
;
3239 * This happens, for instance, when a root cache goes away before we
3242 if (!s
->memcg_params
)
3245 if (s
->memcg_params
->is_root_cache
)
3248 memcg
= s
->memcg_params
->memcg
;
3249 id
= memcg_cache_id(memcg
);
3251 root
= s
->memcg_params
->root_cache
;
3252 root
->memcg_params
->memcg_caches
[id
] = NULL
;
3254 mutex_lock(&memcg
->slab_caches_mutex
);
3255 list_del(&s
->memcg_params
->list
);
3256 mutex_unlock(&memcg
->slab_caches_mutex
);
3258 mem_cgroup_put(memcg
);
3260 kfree(s
->memcg_params
);
3264 * During the creation a new cache, we need to disable our accounting mechanism
3265 * altogether. This is true even if we are not creating, but rather just
3266 * enqueing new caches to be created.
3268 * This is because that process will trigger allocations; some visible, like
3269 * explicit kmallocs to auxiliary data structures, name strings and internal
3270 * cache structures; some well concealed, like INIT_WORK() that can allocate
3271 * objects during debug.
3273 * If any allocation happens during memcg_kmem_get_cache, we will recurse back
3274 * to it. This may not be a bounded recursion: since the first cache creation
3275 * failed to complete (waiting on the allocation), we'll just try to create the
3276 * cache again, failing at the same point.
3278 * memcg_kmem_get_cache is prepared to abort after seeing a positive count of
3279 * memcg_kmem_skip_account. So we enclose anything that might allocate memory
3280 * inside the following two functions.
3282 static inline void memcg_stop_kmem_account(void)
3284 VM_BUG_ON(!current
->mm
);
3285 current
->memcg_kmem_skip_account
++;
3288 static inline void memcg_resume_kmem_account(void)
3290 VM_BUG_ON(!current
->mm
);
3291 current
->memcg_kmem_skip_account
--;
3294 static void kmem_cache_destroy_work_func(struct work_struct
*w
)
3296 struct kmem_cache
*cachep
;
3297 struct memcg_cache_params
*p
;
3299 p
= container_of(w
, struct memcg_cache_params
, destroy
);
3301 cachep
= memcg_params_to_cache(p
);
3304 * If we get down to 0 after shrink, we could delete right away.
3305 * However, memcg_release_pages() already puts us back in the workqueue
3306 * in that case. If we proceed deleting, we'll get a dangling
3307 * reference, and removing the object from the workqueue in that case
3308 * is unnecessary complication. We are not a fast path.
3310 * Note that this case is fundamentally different from racing with
3311 * shrink_slab(): if memcg_cgroup_destroy_cache() is called in
3312 * kmem_cache_shrink, not only we would be reinserting a dead cache
3313 * into the queue, but doing so from inside the worker racing to
3316 * So if we aren't down to zero, we'll just schedule a worker and try
3319 if (atomic_read(&cachep
->memcg_params
->nr_pages
) != 0) {
3320 kmem_cache_shrink(cachep
);
3321 if (atomic_read(&cachep
->memcg_params
->nr_pages
) == 0)
3324 kmem_cache_destroy(cachep
);
3327 void mem_cgroup_destroy_cache(struct kmem_cache
*cachep
)
3329 if (!cachep
->memcg_params
->dead
)
3333 * There are many ways in which we can get here.
3335 * We can get to a memory-pressure situation while the delayed work is
3336 * still pending to run. The vmscan shrinkers can then release all
3337 * cache memory and get us to destruction. If this is the case, we'll
3338 * be executed twice, which is a bug (the second time will execute over
3339 * bogus data). In this case, cancelling the work should be fine.
3341 * But we can also get here from the worker itself, if
3342 * kmem_cache_shrink is enough to shake all the remaining objects and
3343 * get the page count to 0. In this case, we'll deadlock if we try to
3344 * cancel the work (the worker runs with an internal lock held, which
3345 * is the same lock we would hold for cancel_work_sync().)
3347 * Since we can't possibly know who got us here, just refrain from
3348 * running if there is already work pending
3350 if (work_pending(&cachep
->memcg_params
->destroy
))
3353 * We have to defer the actual destroying to a workqueue, because
3354 * we might currently be in a context that cannot sleep.
3356 schedule_work(&cachep
->memcg_params
->destroy
);
3360 * This lock protects updaters, not readers. We want readers to be as fast as
3361 * they can, and they will either see NULL or a valid cache value. Our model
3362 * allow them to see NULL, in which case the root memcg will be selected.
3364 * We need this lock because multiple allocations to the same cache from a non
3365 * will span more than one worker. Only one of them can create the cache.
3367 static DEFINE_MUTEX(memcg_cache_mutex
);
3370 * Called with memcg_cache_mutex held
3372 static struct kmem_cache
*kmem_cache_dup(struct mem_cgroup
*memcg
,
3373 struct kmem_cache
*s
)
3375 struct kmem_cache
*new;
3376 static char *tmp_name
= NULL
;
3378 lockdep_assert_held(&memcg_cache_mutex
);
3381 * kmem_cache_create_memcg duplicates the given name and
3382 * cgroup_name for this name requires RCU context.
3383 * This static temporary buffer is used to prevent from
3384 * pointless shortliving allocation.
3387 tmp_name
= kmalloc(PATH_MAX
, GFP_KERNEL
);
3393 snprintf(tmp_name
, PATH_MAX
, "%s(%d:%s)", s
->name
,
3394 memcg_cache_id(memcg
), cgroup_name(memcg
->css
.cgroup
));
3397 new = kmem_cache_create_memcg(memcg
, tmp_name
, s
->object_size
, s
->align
,
3398 (s
->flags
& ~SLAB_PANIC
), s
->ctor
, s
);
3401 new->allocflags
|= __GFP_KMEMCG
;
3406 static struct kmem_cache
*memcg_create_kmem_cache(struct mem_cgroup
*memcg
,
3407 struct kmem_cache
*cachep
)
3409 struct kmem_cache
*new_cachep
;
3412 BUG_ON(!memcg_can_account_kmem(memcg
));
3414 idx
= memcg_cache_id(memcg
);
3416 mutex_lock(&memcg_cache_mutex
);
3417 new_cachep
= cachep
->memcg_params
->memcg_caches
[idx
];
3421 new_cachep
= kmem_cache_dup(memcg
, cachep
);
3422 if (new_cachep
== NULL
) {
3423 new_cachep
= cachep
;
3427 mem_cgroup_get(memcg
);
3428 atomic_set(&new_cachep
->memcg_params
->nr_pages
, 0);
3430 cachep
->memcg_params
->memcg_caches
[idx
] = new_cachep
;
3432 * the readers won't lock, make sure everybody sees the updated value,
3433 * so they won't put stuff in the queue again for no reason
3437 mutex_unlock(&memcg_cache_mutex
);
3441 void kmem_cache_destroy_memcg_children(struct kmem_cache
*s
)
3443 struct kmem_cache
*c
;
3446 if (!s
->memcg_params
)
3448 if (!s
->memcg_params
->is_root_cache
)
3452 * If the cache is being destroyed, we trust that there is no one else
3453 * requesting objects from it. Even if there are, the sanity checks in
3454 * kmem_cache_destroy should caught this ill-case.
3456 * Still, we don't want anyone else freeing memcg_caches under our
3457 * noses, which can happen if a new memcg comes to life. As usual,
3458 * we'll take the set_limit_mutex to protect ourselves against this.
3460 mutex_lock(&set_limit_mutex
);
3461 for (i
= 0; i
< memcg_limited_groups_array_size
; i
++) {
3462 c
= s
->memcg_params
->memcg_caches
[i
];
3467 * We will now manually delete the caches, so to avoid races
3468 * we need to cancel all pending destruction workers and
3469 * proceed with destruction ourselves.
3471 * kmem_cache_destroy() will call kmem_cache_shrink internally,
3472 * and that could spawn the workers again: it is likely that
3473 * the cache still have active pages until this very moment.
3474 * This would lead us back to mem_cgroup_destroy_cache.
3476 * But that will not execute at all if the "dead" flag is not
3477 * set, so flip it down to guarantee we are in control.
3479 c
->memcg_params
->dead
= false;
3480 cancel_work_sync(&c
->memcg_params
->destroy
);
3481 kmem_cache_destroy(c
);
3483 mutex_unlock(&set_limit_mutex
);
3486 struct create_work
{
3487 struct mem_cgroup
*memcg
;
3488 struct kmem_cache
*cachep
;
3489 struct work_struct work
;
3492 static void mem_cgroup_destroy_all_caches(struct mem_cgroup
*memcg
)
3494 struct kmem_cache
*cachep
;
3495 struct memcg_cache_params
*params
;
3497 if (!memcg_kmem_is_active(memcg
))
3500 mutex_lock(&memcg
->slab_caches_mutex
);
3501 list_for_each_entry(params
, &memcg
->memcg_slab_caches
, list
) {
3502 cachep
= memcg_params_to_cache(params
);
3503 cachep
->memcg_params
->dead
= true;
3504 schedule_work(&cachep
->memcg_params
->destroy
);
3506 mutex_unlock(&memcg
->slab_caches_mutex
);
3509 static void memcg_create_cache_work_func(struct work_struct
*w
)
3511 struct create_work
*cw
;
3513 cw
= container_of(w
, struct create_work
, work
);
3514 memcg_create_kmem_cache(cw
->memcg
, cw
->cachep
);
3515 /* Drop the reference gotten when we enqueued. */
3516 css_put(&cw
->memcg
->css
);
3521 * Enqueue the creation of a per-memcg kmem_cache.
3523 static void __memcg_create_cache_enqueue(struct mem_cgroup
*memcg
,
3524 struct kmem_cache
*cachep
)
3526 struct create_work
*cw
;
3528 cw
= kmalloc(sizeof(struct create_work
), GFP_NOWAIT
);
3530 css_put(&memcg
->css
);
3535 cw
->cachep
= cachep
;
3537 INIT_WORK(&cw
->work
, memcg_create_cache_work_func
);
3538 schedule_work(&cw
->work
);
3541 static void memcg_create_cache_enqueue(struct mem_cgroup
*memcg
,
3542 struct kmem_cache
*cachep
)
3545 * We need to stop accounting when we kmalloc, because if the
3546 * corresponding kmalloc cache is not yet created, the first allocation
3547 * in __memcg_create_cache_enqueue will recurse.
3549 * However, it is better to enclose the whole function. Depending on
3550 * the debugging options enabled, INIT_WORK(), for instance, can
3551 * trigger an allocation. This too, will make us recurse. Because at
3552 * this point we can't allow ourselves back into memcg_kmem_get_cache,
3553 * the safest choice is to do it like this, wrapping the whole function.
3555 memcg_stop_kmem_account();
3556 __memcg_create_cache_enqueue(memcg
, cachep
);
3557 memcg_resume_kmem_account();
3560 * Return the kmem_cache we're supposed to use for a slab allocation.
3561 * We try to use the current memcg's version of the cache.
3563 * If the cache does not exist yet, if we are the first user of it,
3564 * we either create it immediately, if possible, or create it asynchronously
3566 * In the latter case, we will let the current allocation go through with
3567 * the original cache.
3569 * Can't be called in interrupt context or from kernel threads.
3570 * This function needs to be called with rcu_read_lock() held.
3572 struct kmem_cache
*__memcg_kmem_get_cache(struct kmem_cache
*cachep
,
3575 struct mem_cgroup
*memcg
;
3578 VM_BUG_ON(!cachep
->memcg_params
);
3579 VM_BUG_ON(!cachep
->memcg_params
->is_root_cache
);
3581 if (!current
->mm
|| current
->memcg_kmem_skip_account
)
3585 memcg
= mem_cgroup_from_task(rcu_dereference(current
->mm
->owner
));
3587 if (!memcg_can_account_kmem(memcg
))
3590 idx
= memcg_cache_id(memcg
);
3593 * barrier to mare sure we're always seeing the up to date value. The
3594 * code updating memcg_caches will issue a write barrier to match this.
3596 read_barrier_depends();
3597 if (likely(cachep
->memcg_params
->memcg_caches
[idx
])) {
3598 cachep
= cachep
->memcg_params
->memcg_caches
[idx
];
3602 /* The corresponding put will be done in the workqueue. */
3603 if (!css_tryget(&memcg
->css
))
3608 * If we are in a safe context (can wait, and not in interrupt
3609 * context), we could be be predictable and return right away.
3610 * This would guarantee that the allocation being performed
3611 * already belongs in the new cache.
3613 * However, there are some clashes that can arrive from locking.
3614 * For instance, because we acquire the slab_mutex while doing
3615 * kmem_cache_dup, this means no further allocation could happen
3616 * with the slab_mutex held.
3618 * Also, because cache creation issue get_online_cpus(), this
3619 * creates a lock chain: memcg_slab_mutex -> cpu_hotplug_mutex,
3620 * that ends up reversed during cpu hotplug. (cpuset allocates
3621 * a bunch of GFP_KERNEL memory during cpuup). Due to all that,
3622 * better to defer everything.
3624 memcg_create_cache_enqueue(memcg
, cachep
);
3630 EXPORT_SYMBOL(__memcg_kmem_get_cache
);
3633 * We need to verify if the allocation against current->mm->owner's memcg is
3634 * possible for the given order. But the page is not allocated yet, so we'll
3635 * need a further commit step to do the final arrangements.
3637 * It is possible for the task to switch cgroups in this mean time, so at
3638 * commit time, we can't rely on task conversion any longer. We'll then use
3639 * the handle argument to return to the caller which cgroup we should commit
3640 * against. We could also return the memcg directly and avoid the pointer
3641 * passing, but a boolean return value gives better semantics considering
3642 * the compiled-out case as well.
3644 * Returning true means the allocation is possible.
3647 __memcg_kmem_newpage_charge(gfp_t gfp
, struct mem_cgroup
**_memcg
, int order
)
3649 struct mem_cgroup
*memcg
;
3653 memcg
= try_get_mem_cgroup_from_mm(current
->mm
);
3656 * very rare case described in mem_cgroup_from_task. Unfortunately there
3657 * isn't much we can do without complicating this too much, and it would
3658 * be gfp-dependent anyway. Just let it go
3660 if (unlikely(!memcg
))
3663 if (!memcg_can_account_kmem(memcg
)) {
3664 css_put(&memcg
->css
);
3668 ret
= memcg_charge_kmem(memcg
, gfp
, PAGE_SIZE
<< order
);
3672 css_put(&memcg
->css
);
3676 void __memcg_kmem_commit_charge(struct page
*page
, struct mem_cgroup
*memcg
,
3679 struct page_cgroup
*pc
;
3681 VM_BUG_ON(mem_cgroup_is_root(memcg
));
3683 /* The page allocation failed. Revert */
3685 memcg_uncharge_kmem(memcg
, PAGE_SIZE
<< order
);
3689 pc
= lookup_page_cgroup(page
);
3690 lock_page_cgroup(pc
);
3691 pc
->mem_cgroup
= memcg
;
3692 SetPageCgroupUsed(pc
);
3693 unlock_page_cgroup(pc
);
3696 void __memcg_kmem_uncharge_pages(struct page
*page
, int order
)
3698 struct mem_cgroup
*memcg
= NULL
;
3699 struct page_cgroup
*pc
;
3702 pc
= lookup_page_cgroup(page
);
3704 * Fast unlocked return. Theoretically might have changed, have to
3705 * check again after locking.
3707 if (!PageCgroupUsed(pc
))
3710 lock_page_cgroup(pc
);
3711 if (PageCgroupUsed(pc
)) {
3712 memcg
= pc
->mem_cgroup
;
3713 ClearPageCgroupUsed(pc
);
3715 unlock_page_cgroup(pc
);
3718 * We trust that only if there is a memcg associated with the page, it
3719 * is a valid allocation
3724 VM_BUG_ON(mem_cgroup_is_root(memcg
));
3725 memcg_uncharge_kmem(memcg
, PAGE_SIZE
<< order
);
3728 static inline void mem_cgroup_destroy_all_caches(struct mem_cgroup
*memcg
)
3731 #endif /* CONFIG_MEMCG_KMEM */
3733 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
3735 #define PCGF_NOCOPY_AT_SPLIT (1 << PCG_LOCK | 1 << PCG_MIGRATION)
3737 * Because tail pages are not marked as "used", set it. We're under
3738 * zone->lru_lock, 'splitting on pmd' and compound_lock.
3739 * charge/uncharge will be never happen and move_account() is done under
3740 * compound_lock(), so we don't have to take care of races.
3742 void mem_cgroup_split_huge_fixup(struct page
*head
)
3744 struct page_cgroup
*head_pc
= lookup_page_cgroup(head
);
3745 struct page_cgroup
*pc
;
3746 struct mem_cgroup
*memcg
;
3749 if (mem_cgroup_disabled())
3752 memcg
= head_pc
->mem_cgroup
;
3753 for (i
= 1; i
< HPAGE_PMD_NR
; i
++) {
3755 pc
->mem_cgroup
= memcg
;
3756 smp_wmb();/* see __commit_charge() */
3757 pc
->flags
= head_pc
->flags
& ~PCGF_NOCOPY_AT_SPLIT
;
3759 __this_cpu_sub(memcg
->stat
->count
[MEM_CGROUP_STAT_RSS_HUGE
],
3762 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
3765 * mem_cgroup_move_account - move account of the page
3767 * @nr_pages: number of regular pages (>1 for huge pages)
3768 * @pc: page_cgroup of the page.
3769 * @from: mem_cgroup which the page is moved from.
3770 * @to: mem_cgroup which the page is moved to. @from != @to.
3772 * The caller must confirm following.
3773 * - page is not on LRU (isolate_page() is useful.)
3774 * - compound_lock is held when nr_pages > 1
3776 * This function doesn't do "charge" to new cgroup and doesn't do "uncharge"
3779 static int mem_cgroup_move_account(struct page
*page
,
3780 unsigned int nr_pages
,
3781 struct page_cgroup
*pc
,
3782 struct mem_cgroup
*from
,
3783 struct mem_cgroup
*to
)
3785 unsigned long flags
;
3787 bool anon
= PageAnon(page
);
3789 VM_BUG_ON(from
== to
);
3790 VM_BUG_ON(PageLRU(page
));
3792 * The page is isolated from LRU. So, collapse function
3793 * will not handle this page. But page splitting can happen.
3794 * Do this check under compound_page_lock(). The caller should
3798 if (nr_pages
> 1 && !PageTransHuge(page
))
3801 lock_page_cgroup(pc
);
3804 if (!PageCgroupUsed(pc
) || pc
->mem_cgroup
!= from
)
3807 move_lock_mem_cgroup(from
, &flags
);
3809 if (!anon
&& page_mapped(page
)) {
3810 /* Update mapped_file data for mem_cgroup */
3812 __this_cpu_dec(from
->stat
->count
[MEM_CGROUP_STAT_FILE_MAPPED
]);
3813 __this_cpu_inc(to
->stat
->count
[MEM_CGROUP_STAT_FILE_MAPPED
]);
3816 mem_cgroup_charge_statistics(from
, page
, anon
, -nr_pages
);
3818 /* caller should have done css_get */
3819 pc
->mem_cgroup
= to
;
3820 mem_cgroup_charge_statistics(to
, page
, anon
, nr_pages
);
3821 move_unlock_mem_cgroup(from
, &flags
);
3824 unlock_page_cgroup(pc
);
3828 memcg_check_events(to
, page
);
3829 memcg_check_events(from
, page
);
3835 * mem_cgroup_move_parent - moves page to the parent group
3836 * @page: the page to move
3837 * @pc: page_cgroup of the page
3838 * @child: page's cgroup
3840 * move charges to its parent or the root cgroup if the group has no
3841 * parent (aka use_hierarchy==0).
3842 * Although this might fail (get_page_unless_zero, isolate_lru_page or
3843 * mem_cgroup_move_account fails) the failure is always temporary and
3844 * it signals a race with a page removal/uncharge or migration. In the
3845 * first case the page is on the way out and it will vanish from the LRU
3846 * on the next attempt and the call should be retried later.
3847 * Isolation from the LRU fails only if page has been isolated from
3848 * the LRU since we looked at it and that usually means either global
3849 * reclaim or migration going on. The page will either get back to the
3851 * Finaly mem_cgroup_move_account fails only if the page got uncharged
3852 * (!PageCgroupUsed) or moved to a different group. The page will
3853 * disappear in the next attempt.
3855 static int mem_cgroup_move_parent(struct page
*page
,
3856 struct page_cgroup
*pc
,
3857 struct mem_cgroup
*child
)
3859 struct mem_cgroup
*parent
;
3860 unsigned int nr_pages
;
3861 unsigned long uninitialized_var(flags
);
3864 VM_BUG_ON(mem_cgroup_is_root(child
));
3867 if (!get_page_unless_zero(page
))
3869 if (isolate_lru_page(page
))
3872 nr_pages
= hpage_nr_pages(page
);
3874 parent
= parent_mem_cgroup(child
);
3876 * If no parent, move charges to root cgroup.
3879 parent
= root_mem_cgroup
;
3882 VM_BUG_ON(!PageTransHuge(page
));
3883 flags
= compound_lock_irqsave(page
);
3886 ret
= mem_cgroup_move_account(page
, nr_pages
,
3889 __mem_cgroup_cancel_local_charge(child
, nr_pages
);
3892 compound_unlock_irqrestore(page
, flags
);
3893 putback_lru_page(page
);
3901 * Charge the memory controller for page usage.
3903 * 0 if the charge was successful
3904 * < 0 if the cgroup is over its limit
3906 static int mem_cgroup_charge_common(struct page
*page
, struct mm_struct
*mm
,
3907 gfp_t gfp_mask
, enum charge_type ctype
)
3909 struct mem_cgroup
*memcg
= NULL
;
3910 unsigned int nr_pages
= 1;
3914 if (PageTransHuge(page
)) {
3915 nr_pages
<<= compound_order(page
);
3916 VM_BUG_ON(!PageTransHuge(page
));
3918 * Never OOM-kill a process for a huge page. The
3919 * fault handler will fall back to regular pages.
3924 ret
= __mem_cgroup_try_charge(mm
, gfp_mask
, nr_pages
, &memcg
, oom
);
3927 __mem_cgroup_commit_charge(memcg
, page
, nr_pages
, ctype
, false);
3931 int mem_cgroup_newpage_charge(struct page
*page
,
3932 struct mm_struct
*mm
, gfp_t gfp_mask
)
3934 if (mem_cgroup_disabled())
3936 VM_BUG_ON(page_mapped(page
));
3937 VM_BUG_ON(page
->mapping
&& !PageAnon(page
));
3939 return mem_cgroup_charge_common(page
, mm
, gfp_mask
,
3940 MEM_CGROUP_CHARGE_TYPE_ANON
);
3944 * While swap-in, try_charge -> commit or cancel, the page is locked.
3945 * And when try_charge() successfully returns, one refcnt to memcg without
3946 * struct page_cgroup is acquired. This refcnt will be consumed by
3947 * "commit()" or removed by "cancel()"
3949 static int __mem_cgroup_try_charge_swapin(struct mm_struct
*mm
,
3952 struct mem_cgroup
**memcgp
)
3954 struct mem_cgroup
*memcg
;
3955 struct page_cgroup
*pc
;
3958 pc
= lookup_page_cgroup(page
);
3960 * Every swap fault against a single page tries to charge the
3961 * page, bail as early as possible. shmem_unuse() encounters
3962 * already charged pages, too. The USED bit is protected by
3963 * the page lock, which serializes swap cache removal, which
3964 * in turn serializes uncharging.
3966 if (PageCgroupUsed(pc
))
3968 if (!do_swap_account
)
3970 memcg
= try_get_mem_cgroup_from_page(page
);
3974 ret
= __mem_cgroup_try_charge(NULL
, mask
, 1, memcgp
, true);
3975 css_put(&memcg
->css
);
3980 ret
= __mem_cgroup_try_charge(mm
, mask
, 1, memcgp
, true);
3986 int mem_cgroup_try_charge_swapin(struct mm_struct
*mm
, struct page
*page
,
3987 gfp_t gfp_mask
, struct mem_cgroup
**memcgp
)
3990 if (mem_cgroup_disabled())
3993 * A racing thread's fault, or swapoff, may have already
3994 * updated the pte, and even removed page from swap cache: in
3995 * those cases unuse_pte()'s pte_same() test will fail; but
3996 * there's also a KSM case which does need to charge the page.
3998 if (!PageSwapCache(page
)) {
4001 ret
= __mem_cgroup_try_charge(mm
, gfp_mask
, 1, memcgp
, true);
4006 return __mem_cgroup_try_charge_swapin(mm
, page
, gfp_mask
, memcgp
);
4009 void mem_cgroup_cancel_charge_swapin(struct mem_cgroup
*memcg
)
4011 if (mem_cgroup_disabled())
4015 __mem_cgroup_cancel_charge(memcg
, 1);
4019 __mem_cgroup_commit_charge_swapin(struct page
*page
, struct mem_cgroup
*memcg
,
4020 enum charge_type ctype
)
4022 if (mem_cgroup_disabled())
4027 __mem_cgroup_commit_charge(memcg
, page
, 1, ctype
, true);
4029 * Now swap is on-memory. This means this page may be
4030 * counted both as mem and swap....double count.
4031 * Fix it by uncharging from memsw. Basically, this SwapCache is stable
4032 * under lock_page(). But in do_swap_page()::memory.c, reuse_swap_page()
4033 * may call delete_from_swap_cache() before reach here.
4035 if (do_swap_account
&& PageSwapCache(page
)) {
4036 swp_entry_t ent
= {.val
= page_private(page
)};
4037 mem_cgroup_uncharge_swap(ent
);
4041 void mem_cgroup_commit_charge_swapin(struct page
*page
,
4042 struct mem_cgroup
*memcg
)
4044 __mem_cgroup_commit_charge_swapin(page
, memcg
,
4045 MEM_CGROUP_CHARGE_TYPE_ANON
);
4048 int mem_cgroup_cache_charge(struct page
*page
, struct mm_struct
*mm
,
4051 struct mem_cgroup
*memcg
= NULL
;
4052 enum charge_type type
= MEM_CGROUP_CHARGE_TYPE_CACHE
;
4055 if (mem_cgroup_disabled())
4057 if (PageCompound(page
))
4060 if (!PageSwapCache(page
))
4061 ret
= mem_cgroup_charge_common(page
, mm
, gfp_mask
, type
);
4062 else { /* page is swapcache/shmem */
4063 ret
= __mem_cgroup_try_charge_swapin(mm
, page
,
4066 __mem_cgroup_commit_charge_swapin(page
, memcg
, type
);
4071 static void mem_cgroup_do_uncharge(struct mem_cgroup
*memcg
,
4072 unsigned int nr_pages
,
4073 const enum charge_type ctype
)
4075 struct memcg_batch_info
*batch
= NULL
;
4076 bool uncharge_memsw
= true;
4078 /* If swapout, usage of swap doesn't decrease */
4079 if (!do_swap_account
|| ctype
== MEM_CGROUP_CHARGE_TYPE_SWAPOUT
)
4080 uncharge_memsw
= false;
4082 batch
= ¤t
->memcg_batch
;
4084 * In usual, we do css_get() when we remember memcg pointer.
4085 * But in this case, we keep res->usage until end of a series of
4086 * uncharges. Then, it's ok to ignore memcg's refcnt.
4089 batch
->memcg
= memcg
;
4091 * do_batch > 0 when unmapping pages or inode invalidate/truncate.
4092 * In those cases, all pages freed continuously can be expected to be in
4093 * the same cgroup and we have chance to coalesce uncharges.
4094 * But we do uncharge one by one if this is killed by OOM(TIF_MEMDIE)
4095 * because we want to do uncharge as soon as possible.
4098 if (!batch
->do_batch
|| test_thread_flag(TIF_MEMDIE
))
4099 goto direct_uncharge
;
4102 goto direct_uncharge
;
4105 * In typical case, batch->memcg == mem. This means we can
4106 * merge a series of uncharges to an uncharge of res_counter.
4107 * If not, we uncharge res_counter ony by one.
4109 if (batch
->memcg
!= memcg
)
4110 goto direct_uncharge
;
4111 /* remember freed charge and uncharge it later */
4114 batch
->memsw_nr_pages
++;
4117 res_counter_uncharge(&memcg
->res
, nr_pages
* PAGE_SIZE
);
4119 res_counter_uncharge(&memcg
->memsw
, nr_pages
* PAGE_SIZE
);
4120 if (unlikely(batch
->memcg
!= memcg
))
4121 memcg_oom_recover(memcg
);
4125 * uncharge if !page_mapped(page)
4127 static struct mem_cgroup
*
4128 __mem_cgroup_uncharge_common(struct page
*page
, enum charge_type ctype
,
4131 struct mem_cgroup
*memcg
= NULL
;
4132 unsigned int nr_pages
= 1;
4133 struct page_cgroup
*pc
;
4136 if (mem_cgroup_disabled())
4139 if (PageTransHuge(page
)) {
4140 nr_pages
<<= compound_order(page
);
4141 VM_BUG_ON(!PageTransHuge(page
));
4144 * Check if our page_cgroup is valid
4146 pc
= lookup_page_cgroup(page
);
4147 if (unlikely(!PageCgroupUsed(pc
)))
4150 lock_page_cgroup(pc
);
4152 memcg
= pc
->mem_cgroup
;
4154 if (!PageCgroupUsed(pc
))
4157 anon
= PageAnon(page
);
4160 case MEM_CGROUP_CHARGE_TYPE_ANON
:
4162 * Generally PageAnon tells if it's the anon statistics to be
4163 * updated; but sometimes e.g. mem_cgroup_uncharge_page() is
4164 * used before page reached the stage of being marked PageAnon.
4168 case MEM_CGROUP_CHARGE_TYPE_DROP
:
4169 /* See mem_cgroup_prepare_migration() */
4170 if (page_mapped(page
))
4173 * Pages under migration may not be uncharged. But
4174 * end_migration() /must/ be the one uncharging the
4175 * unused post-migration page and so it has to call
4176 * here with the migration bit still set. See the
4177 * res_counter handling below.
4179 if (!end_migration
&& PageCgroupMigration(pc
))
4182 case MEM_CGROUP_CHARGE_TYPE_SWAPOUT
:
4183 if (!PageAnon(page
)) { /* Shared memory */
4184 if (page
->mapping
&& !page_is_file_cache(page
))
4186 } else if (page_mapped(page
)) /* Anon */
4193 mem_cgroup_charge_statistics(memcg
, page
, anon
, -nr_pages
);
4195 ClearPageCgroupUsed(pc
);
4197 * pc->mem_cgroup is not cleared here. It will be accessed when it's
4198 * freed from LRU. This is safe because uncharged page is expected not
4199 * to be reused (freed soon). Exception is SwapCache, it's handled by
4200 * special functions.
4203 unlock_page_cgroup(pc
);
4205 * even after unlock, we have memcg->res.usage here and this memcg
4206 * will never be freed.
4208 memcg_check_events(memcg
, page
);
4209 if (do_swap_account
&& ctype
== MEM_CGROUP_CHARGE_TYPE_SWAPOUT
) {
4210 mem_cgroup_swap_statistics(memcg
, true);
4211 mem_cgroup_get(memcg
);
4214 * Migration does not charge the res_counter for the
4215 * replacement page, so leave it alone when phasing out the
4216 * page that is unused after the migration.
4218 if (!end_migration
&& !mem_cgroup_is_root(memcg
))
4219 mem_cgroup_do_uncharge(memcg
, nr_pages
, ctype
);
4224 unlock_page_cgroup(pc
);
4228 void mem_cgroup_uncharge_page(struct page
*page
)
4231 if (page_mapped(page
))
4233 VM_BUG_ON(page
->mapping
&& !PageAnon(page
));
4235 * If the page is in swap cache, uncharge should be deferred
4236 * to the swap path, which also properly accounts swap usage
4237 * and handles memcg lifetime.
4239 * Note that this check is not stable and reclaim may add the
4240 * page to swap cache at any time after this. However, if the
4241 * page is not in swap cache by the time page->mapcount hits
4242 * 0, there won't be any page table references to the swap
4243 * slot, and reclaim will free it and not actually write the
4246 if (PageSwapCache(page
))
4248 __mem_cgroup_uncharge_common(page
, MEM_CGROUP_CHARGE_TYPE_ANON
, false);
4251 void mem_cgroup_uncharge_cache_page(struct page
*page
)
4253 VM_BUG_ON(page_mapped(page
));
4254 VM_BUG_ON(page
->mapping
);
4255 __mem_cgroup_uncharge_common(page
, MEM_CGROUP_CHARGE_TYPE_CACHE
, false);
4259 * Batch_start/batch_end is called in unmap_page_range/invlidate/trucate.
4260 * In that cases, pages are freed continuously and we can expect pages
4261 * are in the same memcg. All these calls itself limits the number of
4262 * pages freed at once, then uncharge_start/end() is called properly.
4263 * This may be called prural(2) times in a context,
4266 void mem_cgroup_uncharge_start(void)
4268 current
->memcg_batch
.do_batch
++;
4269 /* We can do nest. */
4270 if (current
->memcg_batch
.do_batch
== 1) {
4271 current
->memcg_batch
.memcg
= NULL
;
4272 current
->memcg_batch
.nr_pages
= 0;
4273 current
->memcg_batch
.memsw_nr_pages
= 0;
4277 void mem_cgroup_uncharge_end(void)
4279 struct memcg_batch_info
*batch
= ¤t
->memcg_batch
;
4281 if (!batch
->do_batch
)
4285 if (batch
->do_batch
) /* If stacked, do nothing. */
4291 * This "batch->memcg" is valid without any css_get/put etc...
4292 * bacause we hide charges behind us.
4294 if (batch
->nr_pages
)
4295 res_counter_uncharge(&batch
->memcg
->res
,
4296 batch
->nr_pages
* PAGE_SIZE
);
4297 if (batch
->memsw_nr_pages
)
4298 res_counter_uncharge(&batch
->memcg
->memsw
,
4299 batch
->memsw_nr_pages
* PAGE_SIZE
);
4300 memcg_oom_recover(batch
->memcg
);
4301 /* forget this pointer (for sanity check) */
4302 batch
->memcg
= NULL
;
4307 * called after __delete_from_swap_cache() and drop "page" account.
4308 * memcg information is recorded to swap_cgroup of "ent"
4311 mem_cgroup_uncharge_swapcache(struct page
*page
, swp_entry_t ent
, bool swapout
)
4313 struct mem_cgroup
*memcg
;
4314 int ctype
= MEM_CGROUP_CHARGE_TYPE_SWAPOUT
;
4316 if (!swapout
) /* this was a swap cache but the swap is unused ! */
4317 ctype
= MEM_CGROUP_CHARGE_TYPE_DROP
;
4319 memcg
= __mem_cgroup_uncharge_common(page
, ctype
, false);
4322 * record memcg information, if swapout && memcg != NULL,
4323 * mem_cgroup_get() was called in uncharge().
4325 if (do_swap_account
&& swapout
&& memcg
)
4326 swap_cgroup_record(ent
, css_id(&memcg
->css
));
4330 #ifdef CONFIG_MEMCG_SWAP
4332 * called from swap_entry_free(). remove record in swap_cgroup and
4333 * uncharge "memsw" account.
4335 void mem_cgroup_uncharge_swap(swp_entry_t ent
)
4337 struct mem_cgroup
*memcg
;
4340 if (!do_swap_account
)
4343 id
= swap_cgroup_record(ent
, 0);
4345 memcg
= mem_cgroup_lookup(id
);
4348 * We uncharge this because swap is freed.
4349 * This memcg can be obsolete one. We avoid calling css_tryget
4351 if (!mem_cgroup_is_root(memcg
))
4352 res_counter_uncharge(&memcg
->memsw
, PAGE_SIZE
);
4353 mem_cgroup_swap_statistics(memcg
, false);
4354 mem_cgroup_put(memcg
);
4360 * mem_cgroup_move_swap_account - move swap charge and swap_cgroup's record.
4361 * @entry: swap entry to be moved
4362 * @from: mem_cgroup which the entry is moved from
4363 * @to: mem_cgroup which the entry is moved to
4365 * It succeeds only when the swap_cgroup's record for this entry is the same
4366 * as the mem_cgroup's id of @from.
4368 * Returns 0 on success, -EINVAL on failure.
4370 * The caller must have charged to @to, IOW, called res_counter_charge() about
4371 * both res and memsw, and called css_get().
4373 static int mem_cgroup_move_swap_account(swp_entry_t entry
,
4374 struct mem_cgroup
*from
, struct mem_cgroup
*to
)
4376 unsigned short old_id
, new_id
;
4378 old_id
= css_id(&from
->css
);
4379 new_id
= css_id(&to
->css
);
4381 if (swap_cgroup_cmpxchg(entry
, old_id
, new_id
) == old_id
) {
4382 mem_cgroup_swap_statistics(from
, false);
4383 mem_cgroup_swap_statistics(to
, true);
4385 * This function is only called from task migration context now.
4386 * It postpones res_counter and refcount handling till the end
4387 * of task migration(mem_cgroup_clear_mc()) for performance
4388 * improvement. But we cannot postpone mem_cgroup_get(to)
4389 * because if the process that has been moved to @to does
4390 * swap-in, the refcount of @to might be decreased to 0.
4398 static inline int mem_cgroup_move_swap_account(swp_entry_t entry
,
4399 struct mem_cgroup
*from
, struct mem_cgroup
*to
)
4406 * Before starting migration, account PAGE_SIZE to mem_cgroup that the old
4409 void mem_cgroup_prepare_migration(struct page
*page
, struct page
*newpage
,
4410 struct mem_cgroup
**memcgp
)
4412 struct mem_cgroup
*memcg
= NULL
;
4413 unsigned int nr_pages
= 1;
4414 struct page_cgroup
*pc
;
4415 enum charge_type ctype
;
4419 if (mem_cgroup_disabled())
4422 if (PageTransHuge(page
))
4423 nr_pages
<<= compound_order(page
);
4425 pc
= lookup_page_cgroup(page
);
4426 lock_page_cgroup(pc
);
4427 if (PageCgroupUsed(pc
)) {
4428 memcg
= pc
->mem_cgroup
;
4429 css_get(&memcg
->css
);
4431 * At migrating an anonymous page, its mapcount goes down
4432 * to 0 and uncharge() will be called. But, even if it's fully
4433 * unmapped, migration may fail and this page has to be
4434 * charged again. We set MIGRATION flag here and delay uncharge
4435 * until end_migration() is called
4437 * Corner Case Thinking
4439 * When the old page was mapped as Anon and it's unmap-and-freed
4440 * while migration was ongoing.
4441 * If unmap finds the old page, uncharge() of it will be delayed
4442 * until end_migration(). If unmap finds a new page, it's
4443 * uncharged when it make mapcount to be 1->0. If unmap code
4444 * finds swap_migration_entry, the new page will not be mapped
4445 * and end_migration() will find it(mapcount==0).
4448 * When the old page was mapped but migraion fails, the kernel
4449 * remaps it. A charge for it is kept by MIGRATION flag even
4450 * if mapcount goes down to 0. We can do remap successfully
4451 * without charging it again.
4454 * The "old" page is under lock_page() until the end of
4455 * migration, so, the old page itself will not be swapped-out.
4456 * If the new page is swapped out before end_migraton, our
4457 * hook to usual swap-out path will catch the event.
4460 SetPageCgroupMigration(pc
);
4462 unlock_page_cgroup(pc
);
4464 * If the page is not charged at this point,
4472 * We charge new page before it's used/mapped. So, even if unlock_page()
4473 * is called before end_migration, we can catch all events on this new
4474 * page. In the case new page is migrated but not remapped, new page's
4475 * mapcount will be finally 0 and we call uncharge in end_migration().
4478 ctype
= MEM_CGROUP_CHARGE_TYPE_ANON
;
4480 ctype
= MEM_CGROUP_CHARGE_TYPE_CACHE
;
4482 * The page is committed to the memcg, but it's not actually
4483 * charged to the res_counter since we plan on replacing the
4484 * old one and only one page is going to be left afterwards.
4486 __mem_cgroup_commit_charge(memcg
, newpage
, nr_pages
, ctype
, false);
4489 /* remove redundant charge if migration failed*/
4490 void mem_cgroup_end_migration(struct mem_cgroup
*memcg
,
4491 struct page
*oldpage
, struct page
*newpage
, bool migration_ok
)
4493 struct page
*used
, *unused
;
4494 struct page_cgroup
*pc
;
4500 if (!migration_ok
) {
4507 anon
= PageAnon(used
);
4508 __mem_cgroup_uncharge_common(unused
,
4509 anon
? MEM_CGROUP_CHARGE_TYPE_ANON
4510 : MEM_CGROUP_CHARGE_TYPE_CACHE
,
4512 css_put(&memcg
->css
);
4514 * We disallowed uncharge of pages under migration because mapcount
4515 * of the page goes down to zero, temporarly.
4516 * Clear the flag and check the page should be charged.
4518 pc
= lookup_page_cgroup(oldpage
);
4519 lock_page_cgroup(pc
);
4520 ClearPageCgroupMigration(pc
);
4521 unlock_page_cgroup(pc
);
4524 * If a page is a file cache, radix-tree replacement is very atomic
4525 * and we can skip this check. When it was an Anon page, its mapcount
4526 * goes down to 0. But because we added MIGRATION flage, it's not
4527 * uncharged yet. There are several case but page->mapcount check
4528 * and USED bit check in mem_cgroup_uncharge_page() will do enough
4529 * check. (see prepare_charge() also)
4532 mem_cgroup_uncharge_page(used
);
4536 * At replace page cache, newpage is not under any memcg but it's on
4537 * LRU. So, this function doesn't touch res_counter but handles LRU
4538 * in correct way. Both pages are locked so we cannot race with uncharge.
4540 void mem_cgroup_replace_page_cache(struct page
*oldpage
,
4541 struct page
*newpage
)
4543 struct mem_cgroup
*memcg
= NULL
;
4544 struct page_cgroup
*pc
;
4545 enum charge_type type
= MEM_CGROUP_CHARGE_TYPE_CACHE
;
4547 if (mem_cgroup_disabled())
4550 pc
= lookup_page_cgroup(oldpage
);
4551 /* fix accounting on old pages */
4552 lock_page_cgroup(pc
);
4553 if (PageCgroupUsed(pc
)) {
4554 memcg
= pc
->mem_cgroup
;
4555 mem_cgroup_charge_statistics(memcg
, oldpage
, false, -1);
4556 ClearPageCgroupUsed(pc
);
4558 unlock_page_cgroup(pc
);
4561 * When called from shmem_replace_page(), in some cases the
4562 * oldpage has already been charged, and in some cases not.
4567 * Even if newpage->mapping was NULL before starting replacement,
4568 * the newpage may be on LRU(or pagevec for LRU) already. We lock
4569 * LRU while we overwrite pc->mem_cgroup.
4571 __mem_cgroup_commit_charge(memcg
, newpage
, 1, type
, true);
4574 #ifdef CONFIG_DEBUG_VM
4575 static struct page_cgroup
*lookup_page_cgroup_used(struct page
*page
)
4577 struct page_cgroup
*pc
;
4579 pc
= lookup_page_cgroup(page
);
4581 * Can be NULL while feeding pages into the page allocator for
4582 * the first time, i.e. during boot or memory hotplug;
4583 * or when mem_cgroup_disabled().
4585 if (likely(pc
) && PageCgroupUsed(pc
))
4590 bool mem_cgroup_bad_page_check(struct page
*page
)
4592 if (mem_cgroup_disabled())
4595 return lookup_page_cgroup_used(page
) != NULL
;
4598 void mem_cgroup_print_bad_page(struct page
*page
)
4600 struct page_cgroup
*pc
;
4602 pc
= lookup_page_cgroup_used(page
);
4604 pr_alert("pc:%p pc->flags:%lx pc->mem_cgroup:%p\n",
4605 pc
, pc
->flags
, pc
->mem_cgroup
);
4610 static int mem_cgroup_resize_limit(struct mem_cgroup
*memcg
,
4611 unsigned long long val
)
4614 u64 memswlimit
, memlimit
;
4616 int children
= mem_cgroup_count_children(memcg
);
4617 u64 curusage
, oldusage
;
4621 * For keeping hierarchical_reclaim simple, how long we should retry
4622 * is depends on callers. We set our retry-count to be function
4623 * of # of children which we should visit in this loop.
4625 retry_count
= MEM_CGROUP_RECLAIM_RETRIES
* children
;
4627 oldusage
= res_counter_read_u64(&memcg
->res
, RES_USAGE
);
4630 while (retry_count
) {
4631 if (signal_pending(current
)) {
4636 * Rather than hide all in some function, I do this in
4637 * open coded manner. You see what this really does.
4638 * We have to guarantee memcg->res.limit <= memcg->memsw.limit.
4640 mutex_lock(&set_limit_mutex
);
4641 memswlimit
= res_counter_read_u64(&memcg
->memsw
, RES_LIMIT
);
4642 if (memswlimit
< val
) {
4644 mutex_unlock(&set_limit_mutex
);
4648 memlimit
= res_counter_read_u64(&memcg
->res
, RES_LIMIT
);
4652 ret
= res_counter_set_limit(&memcg
->res
, val
);
4654 if (memswlimit
== val
)
4655 memcg
->memsw_is_minimum
= true;
4657 memcg
->memsw_is_minimum
= false;
4659 mutex_unlock(&set_limit_mutex
);
4664 mem_cgroup_reclaim(memcg
, GFP_KERNEL
,
4665 MEM_CGROUP_RECLAIM_SHRINK
);
4666 curusage
= res_counter_read_u64(&memcg
->res
, RES_USAGE
);
4667 /* Usage is reduced ? */
4668 if (curusage
>= oldusage
)
4671 oldusage
= curusage
;
4673 if (!ret
&& enlarge
)
4674 memcg_oom_recover(memcg
);
4679 static int mem_cgroup_resize_memsw_limit(struct mem_cgroup
*memcg
,
4680 unsigned long long val
)
4683 u64 memlimit
, memswlimit
, oldusage
, curusage
;
4684 int children
= mem_cgroup_count_children(memcg
);
4688 /* see mem_cgroup_resize_res_limit */
4689 retry_count
= children
* MEM_CGROUP_RECLAIM_RETRIES
;
4690 oldusage
= res_counter_read_u64(&memcg
->memsw
, RES_USAGE
);
4691 while (retry_count
) {
4692 if (signal_pending(current
)) {
4697 * Rather than hide all in some function, I do this in
4698 * open coded manner. You see what this really does.
4699 * We have to guarantee memcg->res.limit <= memcg->memsw.limit.
4701 mutex_lock(&set_limit_mutex
);
4702 memlimit
= res_counter_read_u64(&memcg
->res
, RES_LIMIT
);
4703 if (memlimit
> val
) {
4705 mutex_unlock(&set_limit_mutex
);
4708 memswlimit
= res_counter_read_u64(&memcg
->memsw
, RES_LIMIT
);
4709 if (memswlimit
< val
)
4711 ret
= res_counter_set_limit(&memcg
->memsw
, val
);
4713 if (memlimit
== val
)
4714 memcg
->memsw_is_minimum
= true;
4716 memcg
->memsw_is_minimum
= false;
4718 mutex_unlock(&set_limit_mutex
);
4723 mem_cgroup_reclaim(memcg
, GFP_KERNEL
,
4724 MEM_CGROUP_RECLAIM_NOSWAP
|
4725 MEM_CGROUP_RECLAIM_SHRINK
);
4726 curusage
= res_counter_read_u64(&memcg
->memsw
, RES_USAGE
);
4727 /* Usage is reduced ? */
4728 if (curusage
>= oldusage
)
4731 oldusage
= curusage
;
4733 if (!ret
&& enlarge
)
4734 memcg_oom_recover(memcg
);
4738 unsigned long mem_cgroup_soft_limit_reclaim(struct zone
*zone
, int order
,
4740 unsigned long *total_scanned
)
4742 unsigned long nr_reclaimed
= 0;
4743 struct mem_cgroup_per_zone
*mz
, *next_mz
= NULL
;
4744 unsigned long reclaimed
;
4746 struct mem_cgroup_tree_per_zone
*mctz
;
4747 unsigned long long excess
;
4748 unsigned long nr_scanned
;
4753 mctz
= soft_limit_tree_node_zone(zone_to_nid(zone
), zone_idx(zone
));
4755 * This loop can run a while, specially if mem_cgroup's continuously
4756 * keep exceeding their soft limit and putting the system under
4763 mz
= mem_cgroup_largest_soft_limit_node(mctz
);
4768 reclaimed
= mem_cgroup_soft_reclaim(mz
->memcg
, zone
,
4769 gfp_mask
, &nr_scanned
);
4770 nr_reclaimed
+= reclaimed
;
4771 *total_scanned
+= nr_scanned
;
4772 spin_lock(&mctz
->lock
);
4775 * If we failed to reclaim anything from this memory cgroup
4776 * it is time to move on to the next cgroup
4782 * Loop until we find yet another one.
4784 * By the time we get the soft_limit lock
4785 * again, someone might have aded the
4786 * group back on the RB tree. Iterate to
4787 * make sure we get a different mem.
4788 * mem_cgroup_largest_soft_limit_node returns
4789 * NULL if no other cgroup is present on
4793 __mem_cgroup_largest_soft_limit_node(mctz
);
4795 css_put(&next_mz
->memcg
->css
);
4796 else /* next_mz == NULL or other memcg */
4800 __mem_cgroup_remove_exceeded(mz
->memcg
, mz
, mctz
);
4801 excess
= res_counter_soft_limit_excess(&mz
->memcg
->res
);
4803 * One school of thought says that we should not add
4804 * back the node to the tree if reclaim returns 0.
4805 * But our reclaim could return 0, simply because due
4806 * to priority we are exposing a smaller subset of
4807 * memory to reclaim from. Consider this as a longer
4810 /* If excess == 0, no tree ops */
4811 __mem_cgroup_insert_exceeded(mz
->memcg
, mz
, mctz
, excess
);
4812 spin_unlock(&mctz
->lock
);
4813 css_put(&mz
->memcg
->css
);
4816 * Could not reclaim anything and there are no more
4817 * mem cgroups to try or we seem to be looping without
4818 * reclaiming anything.
4820 if (!nr_reclaimed
&&
4822 loop
> MEM_CGROUP_MAX_SOFT_LIMIT_RECLAIM_LOOPS
))
4824 } while (!nr_reclaimed
);
4826 css_put(&next_mz
->memcg
->css
);
4827 return nr_reclaimed
;
4831 * mem_cgroup_force_empty_list - clears LRU of a group
4832 * @memcg: group to clear
4835 * @lru: lru to to clear
4837 * Traverse a specified page_cgroup list and try to drop them all. This doesn't
4838 * reclaim the pages page themselves - pages are moved to the parent (or root)
4841 static void mem_cgroup_force_empty_list(struct mem_cgroup
*memcg
,
4842 int node
, int zid
, enum lru_list lru
)
4844 struct lruvec
*lruvec
;
4845 unsigned long flags
;
4846 struct list_head
*list
;
4850 zone
= &NODE_DATA(node
)->node_zones
[zid
];
4851 lruvec
= mem_cgroup_zone_lruvec(zone
, memcg
);
4852 list
= &lruvec
->lists
[lru
];
4856 struct page_cgroup
*pc
;
4859 spin_lock_irqsave(&zone
->lru_lock
, flags
);
4860 if (list_empty(list
)) {
4861 spin_unlock_irqrestore(&zone
->lru_lock
, flags
);
4864 page
= list_entry(list
->prev
, struct page
, lru
);
4866 list_move(&page
->lru
, list
);
4868 spin_unlock_irqrestore(&zone
->lru_lock
, flags
);
4871 spin_unlock_irqrestore(&zone
->lru_lock
, flags
);
4873 pc
= lookup_page_cgroup(page
);
4875 if (mem_cgroup_move_parent(page
, pc
, memcg
)) {
4876 /* found lock contention or "pc" is obsolete. */
4881 } while (!list_empty(list
));
4885 * make mem_cgroup's charge to be 0 if there is no task by moving
4886 * all the charges and pages to the parent.
4887 * This enables deleting this mem_cgroup.
4889 * Caller is responsible for holding css reference on the memcg.
4891 static void mem_cgroup_reparent_charges(struct mem_cgroup
*memcg
)
4897 /* This is for making all *used* pages to be on LRU. */
4898 lru_add_drain_all();
4899 drain_all_stock_sync(memcg
);
4900 mem_cgroup_start_move(memcg
);
4901 for_each_node_state(node
, N_MEMORY
) {
4902 for (zid
= 0; zid
< MAX_NR_ZONES
; zid
++) {
4905 mem_cgroup_force_empty_list(memcg
,
4910 mem_cgroup_end_move(memcg
);
4911 memcg_oom_recover(memcg
);
4915 * Kernel memory may not necessarily be trackable to a specific
4916 * process. So they are not migrated, and therefore we can't
4917 * expect their value to drop to 0 here.
4918 * Having res filled up with kmem only is enough.
4920 * This is a safety check because mem_cgroup_force_empty_list
4921 * could have raced with mem_cgroup_replace_page_cache callers
4922 * so the lru seemed empty but the page could have been added
4923 * right after the check. RES_USAGE should be safe as we always
4924 * charge before adding to the LRU.
4926 usage
= res_counter_read_u64(&memcg
->res
, RES_USAGE
) -
4927 res_counter_read_u64(&memcg
->kmem
, RES_USAGE
);
4928 } while (usage
> 0);
4932 * This mainly exists for tests during the setting of set of use_hierarchy.
4933 * Since this is the very setting we are changing, the current hierarchy value
4936 static inline bool __memcg_has_children(struct mem_cgroup
*memcg
)
4940 /* bounce at first found */
4941 cgroup_for_each_child(pos
, memcg
->css
.cgroup
)
4947 * Must be called with memcg_create_mutex held, unless the cgroup is guaranteed
4948 * to be already dead (as in mem_cgroup_force_empty, for instance). This is
4949 * from mem_cgroup_count_children(), in the sense that we don't really care how
4950 * many children we have; we only need to know if we have any. It also counts
4951 * any memcg without hierarchy as infertile.
4953 static inline bool memcg_has_children(struct mem_cgroup
*memcg
)
4955 return memcg
->use_hierarchy
&& __memcg_has_children(memcg
);
4959 * Reclaims as many pages from the given memcg as possible and moves
4960 * the rest to the parent.
4962 * Caller is responsible for holding css reference for memcg.
4964 static int mem_cgroup_force_empty(struct mem_cgroup
*memcg
)
4966 int nr_retries
= MEM_CGROUP_RECLAIM_RETRIES
;
4967 struct cgroup
*cgrp
= memcg
->css
.cgroup
;
4969 /* returns EBUSY if there is a task or if we come here twice. */
4970 if (cgroup_task_count(cgrp
) || !list_empty(&cgrp
->children
))
4973 /* we call try-to-free pages for make this cgroup empty */
4974 lru_add_drain_all();
4975 /* try to free all pages in this cgroup */
4976 while (nr_retries
&& res_counter_read_u64(&memcg
->res
, RES_USAGE
) > 0) {
4979 if (signal_pending(current
))
4982 progress
= try_to_free_mem_cgroup_pages(memcg
, GFP_KERNEL
,
4986 /* maybe some writeback is necessary */
4987 congestion_wait(BLK_RW_ASYNC
, HZ
/10);
4992 mem_cgroup_reparent_charges(memcg
);
4997 static int mem_cgroup_force_empty_write(struct cgroup
*cont
, unsigned int event
)
4999 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cont
);
5002 if (mem_cgroup_is_root(memcg
))
5004 css_get(&memcg
->css
);
5005 ret
= mem_cgroup_force_empty(memcg
);
5006 css_put(&memcg
->css
);
5012 static u64
mem_cgroup_hierarchy_read(struct cgroup
*cont
, struct cftype
*cft
)
5014 return mem_cgroup_from_cont(cont
)->use_hierarchy
;
5017 static int mem_cgroup_hierarchy_write(struct cgroup
*cont
, struct cftype
*cft
,
5021 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cont
);
5022 struct cgroup
*parent
= cont
->parent
;
5023 struct mem_cgroup
*parent_memcg
= NULL
;
5026 parent_memcg
= mem_cgroup_from_cont(parent
);
5028 mutex_lock(&memcg_create_mutex
);
5030 if (memcg
->use_hierarchy
== val
)
5034 * If parent's use_hierarchy is set, we can't make any modifications
5035 * in the child subtrees. If it is unset, then the change can
5036 * occur, provided the current cgroup has no children.
5038 * For the root cgroup, parent_mem is NULL, we allow value to be
5039 * set if there are no children.
5041 if ((!parent_memcg
|| !parent_memcg
->use_hierarchy
) &&
5042 (val
== 1 || val
== 0)) {
5043 if (!__memcg_has_children(memcg
))
5044 memcg
->use_hierarchy
= val
;
5051 mutex_unlock(&memcg_create_mutex
);
5057 static unsigned long mem_cgroup_recursive_stat(struct mem_cgroup
*memcg
,
5058 enum mem_cgroup_stat_index idx
)
5060 struct mem_cgroup
*iter
;
5063 /* Per-cpu values can be negative, use a signed accumulator */
5064 for_each_mem_cgroup_tree(iter
, memcg
)
5065 val
+= mem_cgroup_read_stat(iter
, idx
);
5067 if (val
< 0) /* race ? */
5072 static inline u64
mem_cgroup_usage(struct mem_cgroup
*memcg
, bool swap
)
5076 if (!mem_cgroup_is_root(memcg
)) {
5078 return res_counter_read_u64(&memcg
->res
, RES_USAGE
);
5080 return res_counter_read_u64(&memcg
->memsw
, RES_USAGE
);
5084 * Transparent hugepages are still accounted for in MEM_CGROUP_STAT_RSS
5085 * as well as in MEM_CGROUP_STAT_RSS_HUGE.
5087 val
= mem_cgroup_recursive_stat(memcg
, MEM_CGROUP_STAT_CACHE
);
5088 val
+= mem_cgroup_recursive_stat(memcg
, MEM_CGROUP_STAT_RSS
);
5091 val
+= mem_cgroup_recursive_stat(memcg
, MEM_CGROUP_STAT_SWAP
);
5093 return val
<< PAGE_SHIFT
;
5096 static ssize_t
mem_cgroup_read(struct cgroup
*cont
, struct cftype
*cft
,
5097 struct file
*file
, char __user
*buf
,
5098 size_t nbytes
, loff_t
*ppos
)
5100 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cont
);
5106 type
= MEMFILE_TYPE(cft
->private);
5107 name
= MEMFILE_ATTR(cft
->private);
5111 if (name
== RES_USAGE
)
5112 val
= mem_cgroup_usage(memcg
, false);
5114 val
= res_counter_read_u64(&memcg
->res
, name
);
5117 if (name
== RES_USAGE
)
5118 val
= mem_cgroup_usage(memcg
, true);
5120 val
= res_counter_read_u64(&memcg
->memsw
, name
);
5123 val
= res_counter_read_u64(&memcg
->kmem
, name
);
5129 len
= scnprintf(str
, sizeof(str
), "%llu\n", (unsigned long long)val
);
5130 return simple_read_from_buffer(buf
, nbytes
, ppos
, str
, len
);
5133 static int memcg_update_kmem_limit(struct cgroup
*cont
, u64 val
)
5136 #ifdef CONFIG_MEMCG_KMEM
5137 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cont
);
5139 * For simplicity, we won't allow this to be disabled. It also can't
5140 * be changed if the cgroup has children already, or if tasks had
5143 * If tasks join before we set the limit, a person looking at
5144 * kmem.usage_in_bytes will have no way to determine when it took
5145 * place, which makes the value quite meaningless.
5147 * After it first became limited, changes in the value of the limit are
5148 * of course permitted.
5150 mutex_lock(&memcg_create_mutex
);
5151 mutex_lock(&set_limit_mutex
);
5152 if (!memcg
->kmem_account_flags
&& val
!= RESOURCE_MAX
) {
5153 if (cgroup_task_count(cont
) || memcg_has_children(memcg
)) {
5157 ret
= res_counter_set_limit(&memcg
->kmem
, val
);
5160 ret
= memcg_update_cache_sizes(memcg
);
5162 res_counter_set_limit(&memcg
->kmem
, RESOURCE_MAX
);
5165 static_key_slow_inc(&memcg_kmem_enabled_key
);
5167 * setting the active bit after the inc will guarantee no one
5168 * starts accounting before all call sites are patched
5170 memcg_kmem_set_active(memcg
);
5173 * kmem charges can outlive the cgroup. In the case of slab
5174 * pages, for instance, a page contain objects from various
5175 * processes, so it is unfeasible to migrate them away. We
5176 * need to reference count the memcg because of that.
5178 mem_cgroup_get(memcg
);
5180 ret
= res_counter_set_limit(&memcg
->kmem
, val
);
5182 mutex_unlock(&set_limit_mutex
);
5183 mutex_unlock(&memcg_create_mutex
);
5188 #ifdef CONFIG_MEMCG_KMEM
5189 static int memcg_propagate_kmem(struct mem_cgroup
*memcg
)
5192 struct mem_cgroup
*parent
= parent_mem_cgroup(memcg
);
5196 memcg
->kmem_account_flags
= parent
->kmem_account_flags
;
5198 * When that happen, we need to disable the static branch only on those
5199 * memcgs that enabled it. To achieve this, we would be forced to
5200 * complicate the code by keeping track of which memcgs were the ones
5201 * that actually enabled limits, and which ones got it from its
5204 * It is a lot simpler just to do static_key_slow_inc() on every child
5205 * that is accounted.
5207 if (!memcg_kmem_is_active(memcg
))
5211 * destroy(), called if we fail, will issue static_key_slow_inc() and
5212 * mem_cgroup_put() if kmem is enabled. We have to either call them
5213 * unconditionally, or clear the KMEM_ACTIVE flag. I personally find
5214 * this more consistent, since it always leads to the same destroy path
5216 mem_cgroup_get(memcg
);
5217 static_key_slow_inc(&memcg_kmem_enabled_key
);
5219 mutex_lock(&set_limit_mutex
);
5220 ret
= memcg_update_cache_sizes(memcg
);
5221 mutex_unlock(&set_limit_mutex
);
5225 #endif /* CONFIG_MEMCG_KMEM */
5228 * The user of this function is...
5231 static int mem_cgroup_write(struct cgroup
*cont
, struct cftype
*cft
,
5234 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cont
);
5237 unsigned long long val
;
5240 type
= MEMFILE_TYPE(cft
->private);
5241 name
= MEMFILE_ATTR(cft
->private);
5245 if (mem_cgroup_is_root(memcg
)) { /* Can't set limit on root */
5249 /* This function does all necessary parse...reuse it */
5250 ret
= res_counter_memparse_write_strategy(buffer
, &val
);
5254 ret
= mem_cgroup_resize_limit(memcg
, val
);
5255 else if (type
== _MEMSWAP
)
5256 ret
= mem_cgroup_resize_memsw_limit(memcg
, val
);
5257 else if (type
== _KMEM
)
5258 ret
= memcg_update_kmem_limit(cont
, val
);
5262 case RES_SOFT_LIMIT
:
5263 ret
= res_counter_memparse_write_strategy(buffer
, &val
);
5267 * For memsw, soft limits are hard to implement in terms
5268 * of semantics, for now, we support soft limits for
5269 * control without swap
5272 ret
= res_counter_set_soft_limit(&memcg
->res
, val
);
5277 ret
= -EINVAL
; /* should be BUG() ? */
5283 static void memcg_get_hierarchical_limit(struct mem_cgroup
*memcg
,
5284 unsigned long long *mem_limit
, unsigned long long *memsw_limit
)
5286 struct cgroup
*cgroup
;
5287 unsigned long long min_limit
, min_memsw_limit
, tmp
;
5289 min_limit
= res_counter_read_u64(&memcg
->res
, RES_LIMIT
);
5290 min_memsw_limit
= res_counter_read_u64(&memcg
->memsw
, RES_LIMIT
);
5291 cgroup
= memcg
->css
.cgroup
;
5292 if (!memcg
->use_hierarchy
)
5295 while (cgroup
->parent
) {
5296 cgroup
= cgroup
->parent
;
5297 memcg
= mem_cgroup_from_cont(cgroup
);
5298 if (!memcg
->use_hierarchy
)
5300 tmp
= res_counter_read_u64(&memcg
->res
, RES_LIMIT
);
5301 min_limit
= min(min_limit
, tmp
);
5302 tmp
= res_counter_read_u64(&memcg
->memsw
, RES_LIMIT
);
5303 min_memsw_limit
= min(min_memsw_limit
, tmp
);
5306 *mem_limit
= min_limit
;
5307 *memsw_limit
= min_memsw_limit
;
5310 static int mem_cgroup_reset(struct cgroup
*cont
, unsigned int event
)
5312 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cont
);
5316 type
= MEMFILE_TYPE(event
);
5317 name
= MEMFILE_ATTR(event
);
5322 res_counter_reset_max(&memcg
->res
);
5323 else if (type
== _MEMSWAP
)
5324 res_counter_reset_max(&memcg
->memsw
);
5325 else if (type
== _KMEM
)
5326 res_counter_reset_max(&memcg
->kmem
);
5332 res_counter_reset_failcnt(&memcg
->res
);
5333 else if (type
== _MEMSWAP
)
5334 res_counter_reset_failcnt(&memcg
->memsw
);
5335 else if (type
== _KMEM
)
5336 res_counter_reset_failcnt(&memcg
->kmem
);
5345 static u64
mem_cgroup_move_charge_read(struct cgroup
*cgrp
,
5348 return mem_cgroup_from_cont(cgrp
)->move_charge_at_immigrate
;
5352 static int mem_cgroup_move_charge_write(struct cgroup
*cgrp
,
5353 struct cftype
*cft
, u64 val
)
5355 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cgrp
);
5357 if (val
>= (1 << NR_MOVE_TYPE
))
5361 * No kind of locking is needed in here, because ->can_attach() will
5362 * check this value once in the beginning of the process, and then carry
5363 * on with stale data. This means that changes to this value will only
5364 * affect task migrations starting after the change.
5366 memcg
->move_charge_at_immigrate
= val
;
5370 static int mem_cgroup_move_charge_write(struct cgroup
*cgrp
,
5371 struct cftype
*cft
, u64 val
)
5378 static int memcg_numa_stat_show(struct cgroup
*cont
, struct cftype
*cft
,
5382 unsigned long total_nr
, file_nr
, anon_nr
, unevictable_nr
;
5383 unsigned long node_nr
;
5384 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cont
);
5386 total_nr
= mem_cgroup_nr_lru_pages(memcg
, LRU_ALL
);
5387 seq_printf(m
, "total=%lu", total_nr
);
5388 for_each_node_state(nid
, N_MEMORY
) {
5389 node_nr
= mem_cgroup_node_nr_lru_pages(memcg
, nid
, LRU_ALL
);
5390 seq_printf(m
, " N%d=%lu", nid
, node_nr
);
5394 file_nr
= mem_cgroup_nr_lru_pages(memcg
, LRU_ALL_FILE
);
5395 seq_printf(m
, "file=%lu", file_nr
);
5396 for_each_node_state(nid
, N_MEMORY
) {
5397 node_nr
= mem_cgroup_node_nr_lru_pages(memcg
, nid
,
5399 seq_printf(m
, " N%d=%lu", nid
, node_nr
);
5403 anon_nr
= mem_cgroup_nr_lru_pages(memcg
, LRU_ALL_ANON
);
5404 seq_printf(m
, "anon=%lu", anon_nr
);
5405 for_each_node_state(nid
, N_MEMORY
) {
5406 node_nr
= mem_cgroup_node_nr_lru_pages(memcg
, nid
,
5408 seq_printf(m
, " N%d=%lu", nid
, node_nr
);
5412 unevictable_nr
= mem_cgroup_nr_lru_pages(memcg
, BIT(LRU_UNEVICTABLE
));
5413 seq_printf(m
, "unevictable=%lu", unevictable_nr
);
5414 for_each_node_state(nid
, N_MEMORY
) {
5415 node_nr
= mem_cgroup_node_nr_lru_pages(memcg
, nid
,
5416 BIT(LRU_UNEVICTABLE
));
5417 seq_printf(m
, " N%d=%lu", nid
, node_nr
);
5422 #endif /* CONFIG_NUMA */
5424 static inline void mem_cgroup_lru_names_not_uptodate(void)
5426 BUILD_BUG_ON(ARRAY_SIZE(mem_cgroup_lru_names
) != NR_LRU_LISTS
);
5429 static int memcg_stat_show(struct cgroup
*cont
, struct cftype
*cft
,
5432 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cont
);
5433 struct mem_cgroup
*mi
;
5436 for (i
= 0; i
< MEM_CGROUP_STAT_NSTATS
; i
++) {
5437 if (i
== MEM_CGROUP_STAT_SWAP
&& !do_swap_account
)
5439 seq_printf(m
, "%s %ld\n", mem_cgroup_stat_names
[i
],
5440 mem_cgroup_read_stat(memcg
, i
) * PAGE_SIZE
);
5443 for (i
= 0; i
< MEM_CGROUP_EVENTS_NSTATS
; i
++)
5444 seq_printf(m
, "%s %lu\n", mem_cgroup_events_names
[i
],
5445 mem_cgroup_read_events(memcg
, i
));
5447 for (i
= 0; i
< NR_LRU_LISTS
; i
++)
5448 seq_printf(m
, "%s %lu\n", mem_cgroup_lru_names
[i
],
5449 mem_cgroup_nr_lru_pages(memcg
, BIT(i
)) * PAGE_SIZE
);
5451 /* Hierarchical information */
5453 unsigned long long limit
, memsw_limit
;
5454 memcg_get_hierarchical_limit(memcg
, &limit
, &memsw_limit
);
5455 seq_printf(m
, "hierarchical_memory_limit %llu\n", limit
);
5456 if (do_swap_account
)
5457 seq_printf(m
, "hierarchical_memsw_limit %llu\n",
5461 for (i
= 0; i
< MEM_CGROUP_STAT_NSTATS
; i
++) {
5464 if (i
== MEM_CGROUP_STAT_SWAP
&& !do_swap_account
)
5466 for_each_mem_cgroup_tree(mi
, memcg
)
5467 val
+= mem_cgroup_read_stat(mi
, i
) * PAGE_SIZE
;
5468 seq_printf(m
, "total_%s %lld\n", mem_cgroup_stat_names
[i
], val
);
5471 for (i
= 0; i
< MEM_CGROUP_EVENTS_NSTATS
; i
++) {
5472 unsigned long long val
= 0;
5474 for_each_mem_cgroup_tree(mi
, memcg
)
5475 val
+= mem_cgroup_read_events(mi
, i
);
5476 seq_printf(m
, "total_%s %llu\n",
5477 mem_cgroup_events_names
[i
], val
);
5480 for (i
= 0; i
< NR_LRU_LISTS
; i
++) {
5481 unsigned long long val
= 0;
5483 for_each_mem_cgroup_tree(mi
, memcg
)
5484 val
+= mem_cgroup_nr_lru_pages(mi
, BIT(i
)) * PAGE_SIZE
;
5485 seq_printf(m
, "total_%s %llu\n", mem_cgroup_lru_names
[i
], val
);
5488 #ifdef CONFIG_DEBUG_VM
5491 struct mem_cgroup_per_zone
*mz
;
5492 struct zone_reclaim_stat
*rstat
;
5493 unsigned long recent_rotated
[2] = {0, 0};
5494 unsigned long recent_scanned
[2] = {0, 0};
5496 for_each_online_node(nid
)
5497 for (zid
= 0; zid
< MAX_NR_ZONES
; zid
++) {
5498 mz
= mem_cgroup_zoneinfo(memcg
, nid
, zid
);
5499 rstat
= &mz
->lruvec
.reclaim_stat
;
5501 recent_rotated
[0] += rstat
->recent_rotated
[0];
5502 recent_rotated
[1] += rstat
->recent_rotated
[1];
5503 recent_scanned
[0] += rstat
->recent_scanned
[0];
5504 recent_scanned
[1] += rstat
->recent_scanned
[1];
5506 seq_printf(m
, "recent_rotated_anon %lu\n", recent_rotated
[0]);
5507 seq_printf(m
, "recent_rotated_file %lu\n", recent_rotated
[1]);
5508 seq_printf(m
, "recent_scanned_anon %lu\n", recent_scanned
[0]);
5509 seq_printf(m
, "recent_scanned_file %lu\n", recent_scanned
[1]);
5516 static u64
mem_cgroup_swappiness_read(struct cgroup
*cgrp
, struct cftype
*cft
)
5518 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cgrp
);
5520 return mem_cgroup_swappiness(memcg
);
5523 static int mem_cgroup_swappiness_write(struct cgroup
*cgrp
, struct cftype
*cft
,
5526 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cgrp
);
5527 struct mem_cgroup
*parent
;
5532 if (cgrp
->parent
== NULL
)
5535 parent
= mem_cgroup_from_cont(cgrp
->parent
);
5537 mutex_lock(&memcg_create_mutex
);
5539 /* If under hierarchy, only empty-root can set this value */
5540 if ((parent
->use_hierarchy
) || memcg_has_children(memcg
)) {
5541 mutex_unlock(&memcg_create_mutex
);
5545 memcg
->swappiness
= val
;
5547 mutex_unlock(&memcg_create_mutex
);
5552 static void __mem_cgroup_threshold(struct mem_cgroup
*memcg
, bool swap
)
5554 struct mem_cgroup_threshold_ary
*t
;
5560 t
= rcu_dereference(memcg
->thresholds
.primary
);
5562 t
= rcu_dereference(memcg
->memsw_thresholds
.primary
);
5567 usage
= mem_cgroup_usage(memcg
, swap
);
5570 * current_threshold points to threshold just below or equal to usage.
5571 * If it's not true, a threshold was crossed after last
5572 * call of __mem_cgroup_threshold().
5574 i
= t
->current_threshold
;
5577 * Iterate backward over array of thresholds starting from
5578 * current_threshold and check if a threshold is crossed.
5579 * If none of thresholds below usage is crossed, we read
5580 * only one element of the array here.
5582 for (; i
>= 0 && unlikely(t
->entries
[i
].threshold
> usage
); i
--)
5583 eventfd_signal(t
->entries
[i
].eventfd
, 1);
5585 /* i = current_threshold + 1 */
5589 * Iterate forward over array of thresholds starting from
5590 * current_threshold+1 and check if a threshold is crossed.
5591 * If none of thresholds above usage is crossed, we read
5592 * only one element of the array here.
5594 for (; i
< t
->size
&& unlikely(t
->entries
[i
].threshold
<= usage
); i
++)
5595 eventfd_signal(t
->entries
[i
].eventfd
, 1);
5597 /* Update current_threshold */
5598 t
->current_threshold
= i
- 1;
5603 static void mem_cgroup_threshold(struct mem_cgroup
*memcg
)
5606 __mem_cgroup_threshold(memcg
, false);
5607 if (do_swap_account
)
5608 __mem_cgroup_threshold(memcg
, true);
5610 memcg
= parent_mem_cgroup(memcg
);
5614 static int compare_thresholds(const void *a
, const void *b
)
5616 const struct mem_cgroup_threshold
*_a
= a
;
5617 const struct mem_cgroup_threshold
*_b
= b
;
5619 if (_a
->threshold
> _b
->threshold
)
5622 if (_a
->threshold
< _b
->threshold
)
5628 static int mem_cgroup_oom_notify_cb(struct mem_cgroup
*memcg
)
5630 struct mem_cgroup_eventfd_list
*ev
;
5632 list_for_each_entry(ev
, &memcg
->oom_notify
, list
)
5633 eventfd_signal(ev
->eventfd
, 1);
5637 static void mem_cgroup_oom_notify(struct mem_cgroup
*memcg
)
5639 struct mem_cgroup
*iter
;
5641 for_each_mem_cgroup_tree(iter
, memcg
)
5642 mem_cgroup_oom_notify_cb(iter
);
5645 static int mem_cgroup_usage_register_event(struct cgroup
*cgrp
,
5646 struct cftype
*cft
, struct eventfd_ctx
*eventfd
, const char *args
)
5648 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cgrp
);
5649 struct mem_cgroup_thresholds
*thresholds
;
5650 struct mem_cgroup_threshold_ary
*new;
5651 enum res_type type
= MEMFILE_TYPE(cft
->private);
5652 u64 threshold
, usage
;
5655 ret
= res_counter_memparse_write_strategy(args
, &threshold
);
5659 mutex_lock(&memcg
->thresholds_lock
);
5662 thresholds
= &memcg
->thresholds
;
5663 else if (type
== _MEMSWAP
)
5664 thresholds
= &memcg
->memsw_thresholds
;
5668 usage
= mem_cgroup_usage(memcg
, type
== _MEMSWAP
);
5670 /* Check if a threshold crossed before adding a new one */
5671 if (thresholds
->primary
)
5672 __mem_cgroup_threshold(memcg
, type
== _MEMSWAP
);
5674 size
= thresholds
->primary
? thresholds
->primary
->size
+ 1 : 1;
5676 /* Allocate memory for new array of thresholds */
5677 new = kmalloc(sizeof(*new) + size
* sizeof(struct mem_cgroup_threshold
),
5685 /* Copy thresholds (if any) to new array */
5686 if (thresholds
->primary
) {
5687 memcpy(new->entries
, thresholds
->primary
->entries
, (size
- 1) *
5688 sizeof(struct mem_cgroup_threshold
));
5691 /* Add new threshold */
5692 new->entries
[size
- 1].eventfd
= eventfd
;
5693 new->entries
[size
- 1].threshold
= threshold
;
5695 /* Sort thresholds. Registering of new threshold isn't time-critical */
5696 sort(new->entries
, size
, sizeof(struct mem_cgroup_threshold
),
5697 compare_thresholds
, NULL
);
5699 /* Find current threshold */
5700 new->current_threshold
= -1;
5701 for (i
= 0; i
< size
; i
++) {
5702 if (new->entries
[i
].threshold
<= usage
) {
5704 * new->current_threshold will not be used until
5705 * rcu_assign_pointer(), so it's safe to increment
5708 ++new->current_threshold
;
5713 /* Free old spare buffer and save old primary buffer as spare */
5714 kfree(thresholds
->spare
);
5715 thresholds
->spare
= thresholds
->primary
;
5717 rcu_assign_pointer(thresholds
->primary
, new);
5719 /* To be sure that nobody uses thresholds */
5723 mutex_unlock(&memcg
->thresholds_lock
);
5728 static void mem_cgroup_usage_unregister_event(struct cgroup
*cgrp
,
5729 struct cftype
*cft
, struct eventfd_ctx
*eventfd
)
5731 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cgrp
);
5732 struct mem_cgroup_thresholds
*thresholds
;
5733 struct mem_cgroup_threshold_ary
*new;
5734 enum res_type type
= MEMFILE_TYPE(cft
->private);
5738 mutex_lock(&memcg
->thresholds_lock
);
5740 thresholds
= &memcg
->thresholds
;
5741 else if (type
== _MEMSWAP
)
5742 thresholds
= &memcg
->memsw_thresholds
;
5746 if (!thresholds
->primary
)
5749 usage
= mem_cgroup_usage(memcg
, type
== _MEMSWAP
);
5751 /* Check if a threshold crossed before removing */
5752 __mem_cgroup_threshold(memcg
, type
== _MEMSWAP
);
5754 /* Calculate new number of threshold */
5756 for (i
= 0; i
< thresholds
->primary
->size
; i
++) {
5757 if (thresholds
->primary
->entries
[i
].eventfd
!= eventfd
)
5761 new = thresholds
->spare
;
5763 /* Set thresholds array to NULL if we don't have thresholds */
5772 /* Copy thresholds and find current threshold */
5773 new->current_threshold
= -1;
5774 for (i
= 0, j
= 0; i
< thresholds
->primary
->size
; i
++) {
5775 if (thresholds
->primary
->entries
[i
].eventfd
== eventfd
)
5778 new->entries
[j
] = thresholds
->primary
->entries
[i
];
5779 if (new->entries
[j
].threshold
<= usage
) {
5781 * new->current_threshold will not be used
5782 * until rcu_assign_pointer(), so it's safe to increment
5785 ++new->current_threshold
;
5791 /* Swap primary and spare array */
5792 thresholds
->spare
= thresholds
->primary
;
5794 rcu_assign_pointer(thresholds
->primary
, new);
5796 /* To be sure that nobody uses thresholds */
5799 /* If all events are unregistered, free the spare array */
5801 kfree(thresholds
->spare
);
5802 thresholds
->spare
= NULL
;
5805 mutex_unlock(&memcg
->thresholds_lock
);
5808 static int mem_cgroup_oom_register_event(struct cgroup
*cgrp
,
5809 struct cftype
*cft
, struct eventfd_ctx
*eventfd
, const char *args
)
5811 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cgrp
);
5812 struct mem_cgroup_eventfd_list
*event
;
5813 enum res_type type
= MEMFILE_TYPE(cft
->private);
5815 BUG_ON(type
!= _OOM_TYPE
);
5816 event
= kmalloc(sizeof(*event
), GFP_KERNEL
);
5820 spin_lock(&memcg_oom_lock
);
5822 event
->eventfd
= eventfd
;
5823 list_add(&event
->list
, &memcg
->oom_notify
);
5825 /* already in OOM ? */
5826 if (atomic_read(&memcg
->under_oom
))
5827 eventfd_signal(eventfd
, 1);
5828 spin_unlock(&memcg_oom_lock
);
5833 static void mem_cgroup_oom_unregister_event(struct cgroup
*cgrp
,
5834 struct cftype
*cft
, struct eventfd_ctx
*eventfd
)
5836 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cgrp
);
5837 struct mem_cgroup_eventfd_list
*ev
, *tmp
;
5838 enum res_type type
= MEMFILE_TYPE(cft
->private);
5840 BUG_ON(type
!= _OOM_TYPE
);
5842 spin_lock(&memcg_oom_lock
);
5844 list_for_each_entry_safe(ev
, tmp
, &memcg
->oom_notify
, list
) {
5845 if (ev
->eventfd
== eventfd
) {
5846 list_del(&ev
->list
);
5851 spin_unlock(&memcg_oom_lock
);
5854 static int mem_cgroup_oom_control_read(struct cgroup
*cgrp
,
5855 struct cftype
*cft
, struct cgroup_map_cb
*cb
)
5857 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cgrp
);
5859 cb
->fill(cb
, "oom_kill_disable", memcg
->oom_kill_disable
);
5861 if (atomic_read(&memcg
->under_oom
))
5862 cb
->fill(cb
, "under_oom", 1);
5864 cb
->fill(cb
, "under_oom", 0);
5868 static int mem_cgroup_oom_control_write(struct cgroup
*cgrp
,
5869 struct cftype
*cft
, u64 val
)
5871 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cgrp
);
5872 struct mem_cgroup
*parent
;
5874 /* cannot set to root cgroup and only 0 and 1 are allowed */
5875 if (!cgrp
->parent
|| !((val
== 0) || (val
== 1)))
5878 parent
= mem_cgroup_from_cont(cgrp
->parent
);
5880 mutex_lock(&memcg_create_mutex
);
5881 /* oom-kill-disable is a flag for subhierarchy. */
5882 if ((parent
->use_hierarchy
) || memcg_has_children(memcg
)) {
5883 mutex_unlock(&memcg_create_mutex
);
5886 memcg
->oom_kill_disable
= val
;
5888 memcg_oom_recover(memcg
);
5889 mutex_unlock(&memcg_create_mutex
);
5893 #ifdef CONFIG_MEMCG_KMEM
5894 static int memcg_init_kmem(struct mem_cgroup
*memcg
, struct cgroup_subsys
*ss
)
5898 memcg
->kmemcg_id
= -1;
5899 ret
= memcg_propagate_kmem(memcg
);
5903 return mem_cgroup_sockets_init(memcg
, ss
);
5906 static void kmem_cgroup_destroy(struct mem_cgroup
*memcg
)
5908 mem_cgroup_sockets_destroy(memcg
);
5910 memcg_kmem_mark_dead(memcg
);
5912 if (res_counter_read_u64(&memcg
->kmem
, RES_USAGE
) != 0)
5916 * Charges already down to 0, undo mem_cgroup_get() done in the charge
5917 * path here, being careful not to race with memcg_uncharge_kmem: it is
5918 * possible that the charges went down to 0 between mark_dead and the
5919 * res_counter read, so in that case, we don't need the put
5921 if (memcg_kmem_test_and_clear_dead(memcg
))
5922 mem_cgroup_put(memcg
);
5925 static int memcg_init_kmem(struct mem_cgroup
*memcg
, struct cgroup_subsys
*ss
)
5930 static void kmem_cgroup_destroy(struct mem_cgroup
*memcg
)
5935 static struct cftype mem_cgroup_files
[] = {
5937 .name
= "usage_in_bytes",
5938 .private = MEMFILE_PRIVATE(_MEM
, RES_USAGE
),
5939 .read
= mem_cgroup_read
,
5940 .register_event
= mem_cgroup_usage_register_event
,
5941 .unregister_event
= mem_cgroup_usage_unregister_event
,
5944 .name
= "max_usage_in_bytes",
5945 .private = MEMFILE_PRIVATE(_MEM
, RES_MAX_USAGE
),
5946 .trigger
= mem_cgroup_reset
,
5947 .read
= mem_cgroup_read
,
5950 .name
= "limit_in_bytes",
5951 .private = MEMFILE_PRIVATE(_MEM
, RES_LIMIT
),
5952 .write_string
= mem_cgroup_write
,
5953 .read
= mem_cgroup_read
,
5956 .name
= "soft_limit_in_bytes",
5957 .private = MEMFILE_PRIVATE(_MEM
, RES_SOFT_LIMIT
),
5958 .write_string
= mem_cgroup_write
,
5959 .read
= mem_cgroup_read
,
5963 .private = MEMFILE_PRIVATE(_MEM
, RES_FAILCNT
),
5964 .trigger
= mem_cgroup_reset
,
5965 .read
= mem_cgroup_read
,
5969 .read_seq_string
= memcg_stat_show
,
5972 .name
= "force_empty",
5973 .trigger
= mem_cgroup_force_empty_write
,
5976 .name
= "use_hierarchy",
5977 .flags
= CFTYPE_INSANE
,
5978 .write_u64
= mem_cgroup_hierarchy_write
,
5979 .read_u64
= mem_cgroup_hierarchy_read
,
5982 .name
= "swappiness",
5983 .read_u64
= mem_cgroup_swappiness_read
,
5984 .write_u64
= mem_cgroup_swappiness_write
,
5987 .name
= "move_charge_at_immigrate",
5988 .read_u64
= mem_cgroup_move_charge_read
,
5989 .write_u64
= mem_cgroup_move_charge_write
,
5992 .name
= "oom_control",
5993 .read_map
= mem_cgroup_oom_control_read
,
5994 .write_u64
= mem_cgroup_oom_control_write
,
5995 .register_event
= mem_cgroup_oom_register_event
,
5996 .unregister_event
= mem_cgroup_oom_unregister_event
,
5997 .private = MEMFILE_PRIVATE(_OOM_TYPE
, OOM_CONTROL
),
6000 .name
= "pressure_level",
6001 .register_event
= vmpressure_register_event
,
6002 .unregister_event
= vmpressure_unregister_event
,
6006 .name
= "numa_stat",
6007 .read_seq_string
= memcg_numa_stat_show
,
6010 #ifdef CONFIG_MEMCG_KMEM
6012 .name
= "kmem.limit_in_bytes",
6013 .private = MEMFILE_PRIVATE(_KMEM
, RES_LIMIT
),
6014 .write_string
= mem_cgroup_write
,
6015 .read
= mem_cgroup_read
,
6018 .name
= "kmem.usage_in_bytes",
6019 .private = MEMFILE_PRIVATE(_KMEM
, RES_USAGE
),
6020 .read
= mem_cgroup_read
,
6023 .name
= "kmem.failcnt",
6024 .private = MEMFILE_PRIVATE(_KMEM
, RES_FAILCNT
),
6025 .trigger
= mem_cgroup_reset
,
6026 .read
= mem_cgroup_read
,
6029 .name
= "kmem.max_usage_in_bytes",
6030 .private = MEMFILE_PRIVATE(_KMEM
, RES_MAX_USAGE
),
6031 .trigger
= mem_cgroup_reset
,
6032 .read
= mem_cgroup_read
,
6034 #ifdef CONFIG_SLABINFO
6036 .name
= "kmem.slabinfo",
6037 .read_seq_string
= mem_cgroup_slabinfo_read
,
6041 { }, /* terminate */
6044 #ifdef CONFIG_MEMCG_SWAP
6045 static struct cftype memsw_cgroup_files
[] = {
6047 .name
= "memsw.usage_in_bytes",
6048 .private = MEMFILE_PRIVATE(_MEMSWAP
, RES_USAGE
),
6049 .read
= mem_cgroup_read
,
6050 .register_event
= mem_cgroup_usage_register_event
,
6051 .unregister_event
= mem_cgroup_usage_unregister_event
,
6054 .name
= "memsw.max_usage_in_bytes",
6055 .private = MEMFILE_PRIVATE(_MEMSWAP
, RES_MAX_USAGE
),
6056 .trigger
= mem_cgroup_reset
,
6057 .read
= mem_cgroup_read
,
6060 .name
= "memsw.limit_in_bytes",
6061 .private = MEMFILE_PRIVATE(_MEMSWAP
, RES_LIMIT
),
6062 .write_string
= mem_cgroup_write
,
6063 .read
= mem_cgroup_read
,
6066 .name
= "memsw.failcnt",
6067 .private = MEMFILE_PRIVATE(_MEMSWAP
, RES_FAILCNT
),
6068 .trigger
= mem_cgroup_reset
,
6069 .read
= mem_cgroup_read
,
6071 { }, /* terminate */
6074 static int alloc_mem_cgroup_per_zone_info(struct mem_cgroup
*memcg
, int node
)
6076 struct mem_cgroup_per_node
*pn
;
6077 struct mem_cgroup_per_zone
*mz
;
6078 int zone
, tmp
= node
;
6080 * This routine is called against possible nodes.
6081 * But it's BUG to call kmalloc() against offline node.
6083 * TODO: this routine can waste much memory for nodes which will
6084 * never be onlined. It's better to use memory hotplug callback
6087 if (!node_state(node
, N_NORMAL_MEMORY
))
6089 pn
= kzalloc_node(sizeof(*pn
), GFP_KERNEL
, tmp
);
6093 for (zone
= 0; zone
< MAX_NR_ZONES
; zone
++) {
6094 mz
= &pn
->zoneinfo
[zone
];
6095 lruvec_init(&mz
->lruvec
);
6096 mz
->usage_in_excess
= 0;
6097 mz
->on_tree
= false;
6100 memcg
->info
.nodeinfo
[node
] = pn
;
6104 static void free_mem_cgroup_per_zone_info(struct mem_cgroup
*memcg
, int node
)
6106 kfree(memcg
->info
.nodeinfo
[node
]);
6109 static struct mem_cgroup
*mem_cgroup_alloc(void)
6111 struct mem_cgroup
*memcg
;
6112 size_t size
= memcg_size();
6114 /* Can be very big if nr_node_ids is very big */
6115 if (size
< PAGE_SIZE
)
6116 memcg
= kzalloc(size
, GFP_KERNEL
);
6118 memcg
= vzalloc(size
);
6123 memcg
->stat
= alloc_percpu(struct mem_cgroup_stat_cpu
);
6126 spin_lock_init(&memcg
->pcp_counter_lock
);
6130 if (size
< PAGE_SIZE
)
6138 * At destroying mem_cgroup, references from swap_cgroup can remain.
6139 * (scanning all at force_empty is too costly...)
6141 * Instead of clearing all references at force_empty, we remember
6142 * the number of reference from swap_cgroup and free mem_cgroup when
6143 * it goes down to 0.
6145 * Removal of cgroup itself succeeds regardless of refs from swap.
6148 static void __mem_cgroup_free(struct mem_cgroup
*memcg
)
6151 size_t size
= memcg_size();
6153 mem_cgroup_remove_from_trees(memcg
);
6154 free_css_id(&mem_cgroup_subsys
, &memcg
->css
);
6157 free_mem_cgroup_per_zone_info(memcg
, node
);
6159 free_percpu(memcg
->stat
);
6162 * We need to make sure that (at least for now), the jump label
6163 * destruction code runs outside of the cgroup lock. This is because
6164 * get_online_cpus(), which is called from the static_branch update,
6165 * can't be called inside the cgroup_lock. cpusets are the ones
6166 * enforcing this dependency, so if they ever change, we might as well.
6168 * schedule_work() will guarantee this happens. Be careful if you need
6169 * to move this code around, and make sure it is outside
6172 disarm_static_keys(memcg
);
6173 if (size
< PAGE_SIZE
)
6181 * Helpers for freeing a kmalloc()ed/vzalloc()ed mem_cgroup by RCU,
6182 * but in process context. The work_freeing structure is overlaid
6183 * on the rcu_freeing structure, which itself is overlaid on memsw.
6185 static void free_work(struct work_struct
*work
)
6187 struct mem_cgroup
*memcg
;
6189 memcg
= container_of(work
, struct mem_cgroup
, work_freeing
);
6190 __mem_cgroup_free(memcg
);
6193 static void free_rcu(struct rcu_head
*rcu_head
)
6195 struct mem_cgroup
*memcg
;
6197 memcg
= container_of(rcu_head
, struct mem_cgroup
, rcu_freeing
);
6198 INIT_WORK(&memcg
->work_freeing
, free_work
);
6199 schedule_work(&memcg
->work_freeing
);
6202 static void mem_cgroup_get(struct mem_cgroup
*memcg
)
6204 atomic_inc(&memcg
->refcnt
);
6207 static void __mem_cgroup_put(struct mem_cgroup
*memcg
, int count
)
6209 if (atomic_sub_and_test(count
, &memcg
->refcnt
)) {
6210 struct mem_cgroup
*parent
= parent_mem_cgroup(memcg
);
6211 call_rcu(&memcg
->rcu_freeing
, free_rcu
);
6213 mem_cgroup_put(parent
);
6217 static void mem_cgroup_put(struct mem_cgroup
*memcg
)
6219 __mem_cgroup_put(memcg
, 1);
6223 * Returns the parent mem_cgroup in memcgroup hierarchy with hierarchy enabled.
6225 struct mem_cgroup
*parent_mem_cgroup(struct mem_cgroup
*memcg
)
6227 if (!memcg
->res
.parent
)
6229 return mem_cgroup_from_res_counter(memcg
->res
.parent
, res
);
6231 EXPORT_SYMBOL(parent_mem_cgroup
);
6233 static void __init
mem_cgroup_soft_limit_tree_init(void)
6235 struct mem_cgroup_tree_per_node
*rtpn
;
6236 struct mem_cgroup_tree_per_zone
*rtpz
;
6237 int tmp
, node
, zone
;
6239 for_each_node(node
) {
6241 if (!node_state(node
, N_NORMAL_MEMORY
))
6243 rtpn
= kzalloc_node(sizeof(*rtpn
), GFP_KERNEL
, tmp
);
6246 soft_limit_tree
.rb_tree_per_node
[node
] = rtpn
;
6248 for (zone
= 0; zone
< MAX_NR_ZONES
; zone
++) {
6249 rtpz
= &rtpn
->rb_tree_per_zone
[zone
];
6250 rtpz
->rb_root
= RB_ROOT
;
6251 spin_lock_init(&rtpz
->lock
);
6256 static struct cgroup_subsys_state
* __ref
6257 mem_cgroup_css_alloc(struct cgroup
*cont
)
6259 struct mem_cgroup
*memcg
;
6260 long error
= -ENOMEM
;
6263 memcg
= mem_cgroup_alloc();
6265 return ERR_PTR(error
);
6268 if (alloc_mem_cgroup_per_zone_info(memcg
, node
))
6272 if (cont
->parent
== NULL
) {
6273 root_mem_cgroup
= memcg
;
6274 res_counter_init(&memcg
->res
, NULL
);
6275 res_counter_init(&memcg
->memsw
, NULL
);
6276 res_counter_init(&memcg
->kmem
, NULL
);
6279 memcg
->last_scanned_node
= MAX_NUMNODES
;
6280 INIT_LIST_HEAD(&memcg
->oom_notify
);
6281 atomic_set(&memcg
->refcnt
, 1);
6282 memcg
->move_charge_at_immigrate
= 0;
6283 mutex_init(&memcg
->thresholds_lock
);
6284 spin_lock_init(&memcg
->move_lock
);
6285 vmpressure_init(&memcg
->vmpressure
);
6290 __mem_cgroup_free(memcg
);
6291 return ERR_PTR(error
);
6295 mem_cgroup_css_online(struct cgroup
*cont
)
6297 struct mem_cgroup
*memcg
, *parent
;
6303 mutex_lock(&memcg_create_mutex
);
6304 memcg
= mem_cgroup_from_cont(cont
);
6305 parent
= mem_cgroup_from_cont(cont
->parent
);
6307 memcg
->use_hierarchy
= parent
->use_hierarchy
;
6308 memcg
->oom_kill_disable
= parent
->oom_kill_disable
;
6309 memcg
->swappiness
= mem_cgroup_swappiness(parent
);
6311 if (parent
->use_hierarchy
) {
6312 res_counter_init(&memcg
->res
, &parent
->res
);
6313 res_counter_init(&memcg
->memsw
, &parent
->memsw
);
6314 res_counter_init(&memcg
->kmem
, &parent
->kmem
);
6317 * We increment refcnt of the parent to ensure that we can
6318 * safely access it on res_counter_charge/uncharge.
6319 * This refcnt will be decremented when freeing this
6320 * mem_cgroup(see mem_cgroup_put).
6322 mem_cgroup_get(parent
);
6324 res_counter_init(&memcg
->res
, NULL
);
6325 res_counter_init(&memcg
->memsw
, NULL
);
6326 res_counter_init(&memcg
->kmem
, NULL
);
6328 * Deeper hierachy with use_hierarchy == false doesn't make
6329 * much sense so let cgroup subsystem know about this
6330 * unfortunate state in our controller.
6332 if (parent
!= root_mem_cgroup
)
6333 mem_cgroup_subsys
.broken_hierarchy
= true;
6336 error
= memcg_init_kmem(memcg
, &mem_cgroup_subsys
);
6337 mutex_unlock(&memcg_create_mutex
);
6342 * Announce all parents that a group from their hierarchy is gone.
6344 static void mem_cgroup_invalidate_reclaim_iterators(struct mem_cgroup
*memcg
)
6346 struct mem_cgroup
*parent
= memcg
;
6348 while ((parent
= parent_mem_cgroup(parent
)))
6349 atomic_inc(&parent
->dead_count
);
6352 * if the root memcg is not hierarchical we have to check it
6355 if (!root_mem_cgroup
->use_hierarchy
)
6356 atomic_inc(&root_mem_cgroup
->dead_count
);
6359 static void mem_cgroup_css_offline(struct cgroup
*cont
)
6361 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cont
);
6362 struct cgroup
*iter
;
6364 mem_cgroup_invalidate_reclaim_iterators(memcg
);
6367 * This requires that offlining is serialized. Right now that is
6368 * guaranteed because css_killed_work_fn() holds the cgroup_mutex.
6371 cgroup_for_each_descendant_post(iter
, cont
) {
6373 mem_cgroup_reparent_charges(mem_cgroup_from_cont(iter
));
6377 mem_cgroup_reparent_charges(memcg
);
6379 mem_cgroup_destroy_all_caches(memcg
);
6382 static void mem_cgroup_css_free(struct cgroup
*cont
)
6384 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cont
);
6386 kmem_cgroup_destroy(memcg
);
6388 mem_cgroup_put(memcg
);
6392 /* Handlers for move charge at task migration. */
6393 #define PRECHARGE_COUNT_AT_ONCE 256
6394 static int mem_cgroup_do_precharge(unsigned long count
)
6397 int batch_count
= PRECHARGE_COUNT_AT_ONCE
;
6398 struct mem_cgroup
*memcg
= mc
.to
;
6400 if (mem_cgroup_is_root(memcg
)) {
6401 mc
.precharge
+= count
;
6402 /* we don't need css_get for root */
6405 /* try to charge at once */
6407 struct res_counter
*dummy
;
6409 * "memcg" cannot be under rmdir() because we've already checked
6410 * by cgroup_lock_live_cgroup() that it is not removed and we
6411 * are still under the same cgroup_mutex. So we can postpone
6414 if (res_counter_charge(&memcg
->res
, PAGE_SIZE
* count
, &dummy
))
6416 if (do_swap_account
&& res_counter_charge(&memcg
->memsw
,
6417 PAGE_SIZE
* count
, &dummy
)) {
6418 res_counter_uncharge(&memcg
->res
, PAGE_SIZE
* count
);
6421 mc
.precharge
+= count
;
6425 /* fall back to one by one charge */
6427 if (signal_pending(current
)) {
6431 if (!batch_count
--) {
6432 batch_count
= PRECHARGE_COUNT_AT_ONCE
;
6435 ret
= __mem_cgroup_try_charge(NULL
,
6436 GFP_KERNEL
, 1, &memcg
, false);
6438 /* mem_cgroup_clear_mc() will do uncharge later */
6446 * get_mctgt_type - get target type of moving charge
6447 * @vma: the vma the pte to be checked belongs
6448 * @addr: the address corresponding to the pte to be checked
6449 * @ptent: the pte to be checked
6450 * @target: the pointer the target page or swap ent will be stored(can be NULL)
6453 * 0(MC_TARGET_NONE): if the pte is not a target for move charge.
6454 * 1(MC_TARGET_PAGE): if the page corresponding to this pte is a target for
6455 * move charge. if @target is not NULL, the page is stored in target->page
6456 * with extra refcnt got(Callers should handle it).
6457 * 2(MC_TARGET_SWAP): if the swap entry corresponding to this pte is a
6458 * target for charge migration. if @target is not NULL, the entry is stored
6461 * Called with pte lock held.
6468 enum mc_target_type
{
6474 static struct page
*mc_handle_present_pte(struct vm_area_struct
*vma
,
6475 unsigned long addr
, pte_t ptent
)
6477 struct page
*page
= vm_normal_page(vma
, addr
, ptent
);
6479 if (!page
|| !page_mapped(page
))
6481 if (PageAnon(page
)) {
6482 /* we don't move shared anon */
6485 } else if (!move_file())
6486 /* we ignore mapcount for file pages */
6488 if (!get_page_unless_zero(page
))
6495 static struct page
*mc_handle_swap_pte(struct vm_area_struct
*vma
,
6496 unsigned long addr
, pte_t ptent
, swp_entry_t
*entry
)
6498 struct page
*page
= NULL
;
6499 swp_entry_t ent
= pte_to_swp_entry(ptent
);
6501 if (!move_anon() || non_swap_entry(ent
))
6504 * Because lookup_swap_cache() updates some statistics counter,
6505 * we call find_get_page() with swapper_space directly.
6507 page
= find_get_page(swap_address_space(ent
), ent
.val
);
6508 if (do_swap_account
)
6509 entry
->val
= ent
.val
;
6514 static struct page
*mc_handle_swap_pte(struct vm_area_struct
*vma
,
6515 unsigned long addr
, pte_t ptent
, swp_entry_t
*entry
)
6521 static struct page
*mc_handle_file_pte(struct vm_area_struct
*vma
,
6522 unsigned long addr
, pte_t ptent
, swp_entry_t
*entry
)
6524 struct page
*page
= NULL
;
6525 struct address_space
*mapping
;
6528 if (!vma
->vm_file
) /* anonymous vma */
6533 mapping
= vma
->vm_file
->f_mapping
;
6534 if (pte_none(ptent
))
6535 pgoff
= linear_page_index(vma
, addr
);
6536 else /* pte_file(ptent) is true */
6537 pgoff
= pte_to_pgoff(ptent
);
6539 /* page is moved even if it's not RSS of this task(page-faulted). */
6540 page
= find_get_page(mapping
, pgoff
);
6543 /* shmem/tmpfs may report page out on swap: account for that too. */
6544 if (radix_tree_exceptional_entry(page
)) {
6545 swp_entry_t swap
= radix_to_swp_entry(page
);
6546 if (do_swap_account
)
6548 page
= find_get_page(swap_address_space(swap
), swap
.val
);
6554 static enum mc_target_type
get_mctgt_type(struct vm_area_struct
*vma
,
6555 unsigned long addr
, pte_t ptent
, union mc_target
*target
)
6557 struct page
*page
= NULL
;
6558 struct page_cgroup
*pc
;
6559 enum mc_target_type ret
= MC_TARGET_NONE
;
6560 swp_entry_t ent
= { .val
= 0 };
6562 if (pte_present(ptent
))
6563 page
= mc_handle_present_pte(vma
, addr
, ptent
);
6564 else if (is_swap_pte(ptent
))
6565 page
= mc_handle_swap_pte(vma
, addr
, ptent
, &ent
);
6566 else if (pte_none(ptent
) || pte_file(ptent
))
6567 page
= mc_handle_file_pte(vma
, addr
, ptent
, &ent
);
6569 if (!page
&& !ent
.val
)
6572 pc
= lookup_page_cgroup(page
);
6574 * Do only loose check w/o page_cgroup lock.
6575 * mem_cgroup_move_account() checks the pc is valid or not under
6578 if (PageCgroupUsed(pc
) && pc
->mem_cgroup
== mc
.from
) {
6579 ret
= MC_TARGET_PAGE
;
6581 target
->page
= page
;
6583 if (!ret
|| !target
)
6586 /* There is a swap entry and a page doesn't exist or isn't charged */
6587 if (ent
.val
&& !ret
&&
6588 css_id(&mc
.from
->css
) == lookup_swap_cgroup_id(ent
)) {
6589 ret
= MC_TARGET_SWAP
;
6596 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
6598 * We don't consider swapping or file mapped pages because THP does not
6599 * support them for now.
6600 * Caller should make sure that pmd_trans_huge(pmd) is true.
6602 static enum mc_target_type
get_mctgt_type_thp(struct vm_area_struct
*vma
,
6603 unsigned long addr
, pmd_t pmd
, union mc_target
*target
)
6605 struct page
*page
= NULL
;
6606 struct page_cgroup
*pc
;
6607 enum mc_target_type ret
= MC_TARGET_NONE
;
6609 page
= pmd_page(pmd
);
6610 VM_BUG_ON(!page
|| !PageHead(page
));
6613 pc
= lookup_page_cgroup(page
);
6614 if (PageCgroupUsed(pc
) && pc
->mem_cgroup
== mc
.from
) {
6615 ret
= MC_TARGET_PAGE
;
6618 target
->page
= page
;
6624 static inline enum mc_target_type
get_mctgt_type_thp(struct vm_area_struct
*vma
,
6625 unsigned long addr
, pmd_t pmd
, union mc_target
*target
)
6627 return MC_TARGET_NONE
;
6631 static int mem_cgroup_count_precharge_pte_range(pmd_t
*pmd
,
6632 unsigned long addr
, unsigned long end
,
6633 struct mm_walk
*walk
)
6635 struct vm_area_struct
*vma
= walk
->private;
6639 if (pmd_trans_huge_lock(pmd
, vma
) == 1) {
6640 if (get_mctgt_type_thp(vma
, addr
, *pmd
, NULL
) == MC_TARGET_PAGE
)
6641 mc
.precharge
+= HPAGE_PMD_NR
;
6642 spin_unlock(&vma
->vm_mm
->page_table_lock
);
6646 if (pmd_trans_unstable(pmd
))
6648 pte
= pte_offset_map_lock(vma
->vm_mm
, pmd
, addr
, &ptl
);
6649 for (; addr
!= end
; pte
++, addr
+= PAGE_SIZE
)
6650 if (get_mctgt_type(vma
, addr
, *pte
, NULL
))
6651 mc
.precharge
++; /* increment precharge temporarily */
6652 pte_unmap_unlock(pte
- 1, ptl
);
6658 static unsigned long mem_cgroup_count_precharge(struct mm_struct
*mm
)
6660 unsigned long precharge
;
6661 struct vm_area_struct
*vma
;
6663 down_read(&mm
->mmap_sem
);
6664 for (vma
= mm
->mmap
; vma
; vma
= vma
->vm_next
) {
6665 struct mm_walk mem_cgroup_count_precharge_walk
= {
6666 .pmd_entry
= mem_cgroup_count_precharge_pte_range
,
6670 if (is_vm_hugetlb_page(vma
))
6672 walk_page_range(vma
->vm_start
, vma
->vm_end
,
6673 &mem_cgroup_count_precharge_walk
);
6675 up_read(&mm
->mmap_sem
);
6677 precharge
= mc
.precharge
;
6683 static int mem_cgroup_precharge_mc(struct mm_struct
*mm
)
6685 unsigned long precharge
= mem_cgroup_count_precharge(mm
);
6687 VM_BUG_ON(mc
.moving_task
);
6688 mc
.moving_task
= current
;
6689 return mem_cgroup_do_precharge(precharge
);
6692 /* cancels all extra charges on mc.from and mc.to, and wakes up all waiters. */
6693 static void __mem_cgroup_clear_mc(void)
6695 struct mem_cgroup
*from
= mc
.from
;
6696 struct mem_cgroup
*to
= mc
.to
;
6698 /* we must uncharge all the leftover precharges from mc.to */
6700 __mem_cgroup_cancel_charge(mc
.to
, mc
.precharge
);
6704 * we didn't uncharge from mc.from at mem_cgroup_move_account(), so
6705 * we must uncharge here.
6707 if (mc
.moved_charge
) {
6708 __mem_cgroup_cancel_charge(mc
.from
, mc
.moved_charge
);
6709 mc
.moved_charge
= 0;
6711 /* we must fixup refcnts and charges */
6712 if (mc
.moved_swap
) {
6713 /* uncharge swap account from the old cgroup */
6714 if (!mem_cgroup_is_root(mc
.from
))
6715 res_counter_uncharge(&mc
.from
->memsw
,
6716 PAGE_SIZE
* mc
.moved_swap
);
6717 __mem_cgroup_put(mc
.from
, mc
.moved_swap
);
6719 if (!mem_cgroup_is_root(mc
.to
)) {
6721 * we charged both to->res and to->memsw, so we should
6724 res_counter_uncharge(&mc
.to
->res
,
6725 PAGE_SIZE
* mc
.moved_swap
);
6727 /* we've already done mem_cgroup_get(mc.to) */
6730 memcg_oom_recover(from
);
6731 memcg_oom_recover(to
);
6732 wake_up_all(&mc
.waitq
);
6735 static void mem_cgroup_clear_mc(void)
6737 struct mem_cgroup
*from
= mc
.from
;
6740 * we must clear moving_task before waking up waiters at the end of
6743 mc
.moving_task
= NULL
;
6744 __mem_cgroup_clear_mc();
6745 spin_lock(&mc
.lock
);
6748 spin_unlock(&mc
.lock
);
6749 mem_cgroup_end_move(from
);
6752 static int mem_cgroup_can_attach(struct cgroup
*cgroup
,
6753 struct cgroup_taskset
*tset
)
6755 struct task_struct
*p
= cgroup_taskset_first(tset
);
6757 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cgroup
);
6758 unsigned long move_charge_at_immigrate
;
6761 * We are now commited to this value whatever it is. Changes in this
6762 * tunable will only affect upcoming migrations, not the current one.
6763 * So we need to save it, and keep it going.
6765 move_charge_at_immigrate
= memcg
->move_charge_at_immigrate
;
6766 if (move_charge_at_immigrate
) {
6767 struct mm_struct
*mm
;
6768 struct mem_cgroup
*from
= mem_cgroup_from_task(p
);
6770 VM_BUG_ON(from
== memcg
);
6772 mm
= get_task_mm(p
);
6775 /* We move charges only when we move a owner of the mm */
6776 if (mm
->owner
== p
) {
6779 VM_BUG_ON(mc
.precharge
);
6780 VM_BUG_ON(mc
.moved_charge
);
6781 VM_BUG_ON(mc
.moved_swap
);
6782 mem_cgroup_start_move(from
);
6783 spin_lock(&mc
.lock
);
6786 mc
.immigrate_flags
= move_charge_at_immigrate
;
6787 spin_unlock(&mc
.lock
);
6788 /* We set mc.moving_task later */
6790 ret
= mem_cgroup_precharge_mc(mm
);
6792 mem_cgroup_clear_mc();
6799 static void mem_cgroup_cancel_attach(struct cgroup
*cgroup
,
6800 struct cgroup_taskset
*tset
)
6802 mem_cgroup_clear_mc();
6805 static int mem_cgroup_move_charge_pte_range(pmd_t
*pmd
,
6806 unsigned long addr
, unsigned long end
,
6807 struct mm_walk
*walk
)
6810 struct vm_area_struct
*vma
= walk
->private;
6813 enum mc_target_type target_type
;
6814 union mc_target target
;
6816 struct page_cgroup
*pc
;
6819 * We don't take compound_lock() here but no race with splitting thp
6821 * - if pmd_trans_huge_lock() returns 1, the relevant thp is not
6822 * under splitting, which means there's no concurrent thp split,
6823 * - if another thread runs into split_huge_page() just after we
6824 * entered this if-block, the thread must wait for page table lock
6825 * to be unlocked in __split_huge_page_splitting(), where the main
6826 * part of thp split is not executed yet.
6828 if (pmd_trans_huge_lock(pmd
, vma
) == 1) {
6829 if (mc
.precharge
< HPAGE_PMD_NR
) {
6830 spin_unlock(&vma
->vm_mm
->page_table_lock
);
6833 target_type
= get_mctgt_type_thp(vma
, addr
, *pmd
, &target
);
6834 if (target_type
== MC_TARGET_PAGE
) {
6836 if (!isolate_lru_page(page
)) {
6837 pc
= lookup_page_cgroup(page
);
6838 if (!mem_cgroup_move_account(page
, HPAGE_PMD_NR
,
6839 pc
, mc
.from
, mc
.to
)) {
6840 mc
.precharge
-= HPAGE_PMD_NR
;
6841 mc
.moved_charge
+= HPAGE_PMD_NR
;
6843 putback_lru_page(page
);
6847 spin_unlock(&vma
->vm_mm
->page_table_lock
);
6851 if (pmd_trans_unstable(pmd
))
6854 pte
= pte_offset_map_lock(vma
->vm_mm
, pmd
, addr
, &ptl
);
6855 for (; addr
!= end
; addr
+= PAGE_SIZE
) {
6856 pte_t ptent
= *(pte
++);
6862 switch (get_mctgt_type(vma
, addr
, ptent
, &target
)) {
6863 case MC_TARGET_PAGE
:
6865 if (isolate_lru_page(page
))
6867 pc
= lookup_page_cgroup(page
);
6868 if (!mem_cgroup_move_account(page
, 1, pc
,
6871 /* we uncharge from mc.from later. */
6874 putback_lru_page(page
);
6875 put
: /* get_mctgt_type() gets the page */
6878 case MC_TARGET_SWAP
:
6880 if (!mem_cgroup_move_swap_account(ent
, mc
.from
, mc
.to
)) {
6882 /* we fixup refcnts and charges later. */
6890 pte_unmap_unlock(pte
- 1, ptl
);
6895 * We have consumed all precharges we got in can_attach().
6896 * We try charge one by one, but don't do any additional
6897 * charges to mc.to if we have failed in charge once in attach()
6900 ret
= mem_cgroup_do_precharge(1);
6908 static void mem_cgroup_move_charge(struct mm_struct
*mm
)
6910 struct vm_area_struct
*vma
;
6912 lru_add_drain_all();
6914 if (unlikely(!down_read_trylock(&mm
->mmap_sem
))) {
6916 * Someone who are holding the mmap_sem might be waiting in
6917 * waitq. So we cancel all extra charges, wake up all waiters,
6918 * and retry. Because we cancel precharges, we might not be able
6919 * to move enough charges, but moving charge is a best-effort
6920 * feature anyway, so it wouldn't be a big problem.
6922 __mem_cgroup_clear_mc();
6926 for (vma
= mm
->mmap
; vma
; vma
= vma
->vm_next
) {
6928 struct mm_walk mem_cgroup_move_charge_walk
= {
6929 .pmd_entry
= mem_cgroup_move_charge_pte_range
,
6933 if (is_vm_hugetlb_page(vma
))
6935 ret
= walk_page_range(vma
->vm_start
, vma
->vm_end
,
6936 &mem_cgroup_move_charge_walk
);
6939 * means we have consumed all precharges and failed in
6940 * doing additional charge. Just abandon here.
6944 up_read(&mm
->mmap_sem
);
6947 static void mem_cgroup_move_task(struct cgroup
*cont
,
6948 struct cgroup_taskset
*tset
)
6950 struct task_struct
*p
= cgroup_taskset_first(tset
);
6951 struct mm_struct
*mm
= get_task_mm(p
);
6955 mem_cgroup_move_charge(mm
);
6959 mem_cgroup_clear_mc();
6961 #else /* !CONFIG_MMU */
6962 static int mem_cgroup_can_attach(struct cgroup
*cgroup
,
6963 struct cgroup_taskset
*tset
)
6967 static void mem_cgroup_cancel_attach(struct cgroup
*cgroup
,
6968 struct cgroup_taskset
*tset
)
6971 static void mem_cgroup_move_task(struct cgroup
*cont
,
6972 struct cgroup_taskset
*tset
)
6978 * Cgroup retains root cgroups across [un]mount cycles making it necessary
6979 * to verify sane_behavior flag on each mount attempt.
6981 static void mem_cgroup_bind(struct cgroup
*root
)
6984 * use_hierarchy is forced with sane_behavior. cgroup core
6985 * guarantees that @root doesn't have any children, so turning it
6986 * on for the root memcg is enough.
6988 if (cgroup_sane_behavior(root
))
6989 mem_cgroup_from_cont(root
)->use_hierarchy
= true;
6992 struct cgroup_subsys mem_cgroup_subsys
= {
6994 .subsys_id
= mem_cgroup_subsys_id
,
6995 .css_alloc
= mem_cgroup_css_alloc
,
6996 .css_online
= mem_cgroup_css_online
,
6997 .css_offline
= mem_cgroup_css_offline
,
6998 .css_free
= mem_cgroup_css_free
,
6999 .can_attach
= mem_cgroup_can_attach
,
7000 .cancel_attach
= mem_cgroup_cancel_attach
,
7001 .attach
= mem_cgroup_move_task
,
7002 .bind
= mem_cgroup_bind
,
7003 .base_cftypes
= mem_cgroup_files
,
7008 #ifdef CONFIG_MEMCG_SWAP
7009 static int __init
enable_swap_account(char *s
)
7011 /* consider enabled if no parameter or 1 is given */
7012 if (!strcmp(s
, "1"))
7013 really_do_swap_account
= 1;
7014 else if (!strcmp(s
, "0"))
7015 really_do_swap_account
= 0;
7018 __setup("swapaccount=", enable_swap_account
);
7020 static void __init
memsw_file_init(void)
7022 WARN_ON(cgroup_add_cftypes(&mem_cgroup_subsys
, memsw_cgroup_files
));
7025 static void __init
enable_swap_cgroup(void)
7027 if (!mem_cgroup_disabled() && really_do_swap_account
) {
7028 do_swap_account
= 1;
7034 static void __init
enable_swap_cgroup(void)
7040 * subsys_initcall() for memory controller.
7042 * Some parts like hotcpu_notifier() have to be initialized from this context
7043 * because of lock dependencies (cgroup_lock -> cpu hotplug) but basically
7044 * everything that doesn't depend on a specific mem_cgroup structure should
7045 * be initialized from here.
7047 static int __init
mem_cgroup_init(void)
7049 hotcpu_notifier(memcg_cpu_hotplug_callback
, 0);
7050 enable_swap_cgroup();
7051 mem_cgroup_soft_limit_tree_init();
7055 subsys_initcall(mem_cgroup_init
);