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
];
191 * Cgroups above their limits are maintained in a RB-Tree, independent of
192 * their hierarchy representation
195 struct mem_cgroup_tree_per_zone
{
196 struct rb_root rb_root
;
200 struct mem_cgroup_tree_per_node
{
201 struct mem_cgroup_tree_per_zone rb_tree_per_zone
[MAX_NR_ZONES
];
204 struct mem_cgroup_tree
{
205 struct mem_cgroup_tree_per_node
*rb_tree_per_node
[MAX_NUMNODES
];
208 static struct mem_cgroup_tree soft_limit_tree __read_mostly
;
210 struct mem_cgroup_threshold
{
211 struct eventfd_ctx
*eventfd
;
216 struct mem_cgroup_threshold_ary
{
217 /* An array index points to threshold just below or equal to usage. */
218 int current_threshold
;
219 /* Size of entries[] */
221 /* Array of thresholds */
222 struct mem_cgroup_threshold entries
[0];
225 struct mem_cgroup_thresholds
{
226 /* Primary thresholds array */
227 struct mem_cgroup_threshold_ary
*primary
;
229 * Spare threshold array.
230 * This is needed to make mem_cgroup_unregister_event() "never fail".
231 * It must be able to store at least primary->size - 1 entries.
233 struct mem_cgroup_threshold_ary
*spare
;
237 struct mem_cgroup_eventfd_list
{
238 struct list_head list
;
239 struct eventfd_ctx
*eventfd
;
242 static void mem_cgroup_threshold(struct mem_cgroup
*memcg
);
243 static void mem_cgroup_oom_notify(struct mem_cgroup
*memcg
);
246 * The memory controller data structure. The memory controller controls both
247 * page cache and RSS per cgroup. We would eventually like to provide
248 * statistics based on the statistics developed by Rik Van Riel for clock-pro,
249 * to help the administrator determine what knobs to tune.
251 * TODO: Add a water mark for the memory controller. Reclaim will begin when
252 * we hit the water mark. May be even add a low water mark, such that
253 * no reclaim occurs from a cgroup at it's low water mark, this is
254 * a feature that will be implemented much later in the future.
257 struct cgroup_subsys_state css
;
259 * the counter to account for memory usage
261 struct res_counter res
;
263 /* vmpressure notifications */
264 struct vmpressure vmpressure
;
268 * the counter to account for mem+swap usage.
270 struct res_counter memsw
;
273 * rcu_freeing is used only when freeing struct mem_cgroup,
274 * so put it into a union to avoid wasting more memory.
275 * It must be disjoint from the css field. It could be
276 * in a union with the res field, but res plays a much
277 * larger part in mem_cgroup life than memsw, and might
278 * be of interest, even at time of free, when debugging.
279 * So share rcu_head with the less interesting memsw.
281 struct rcu_head rcu_freeing
;
283 * We also need some space for a worker in deferred freeing.
284 * By the time we call it, rcu_freeing is no longer in use.
286 struct work_struct work_freeing
;
290 * the counter to account for kernel memory usage.
292 struct res_counter kmem
;
294 * Should the accounting and control be hierarchical, per subtree?
297 unsigned long kmem_account_flags
; /* See KMEM_ACCOUNTED_*, below */
305 /* OOM-Killer disable */
306 int oom_kill_disable
;
308 /* set when res.limit == memsw.limit */
309 bool memsw_is_minimum
;
311 /* protect arrays of thresholds */
312 struct mutex thresholds_lock
;
314 /* thresholds for memory usage. RCU-protected */
315 struct mem_cgroup_thresholds thresholds
;
317 /* thresholds for mem+swap usage. RCU-protected */
318 struct mem_cgroup_thresholds memsw_thresholds
;
320 /* For oom notifier event fd */
321 struct list_head oom_notify
;
324 * Should we move charges of a task when a task is moved into this
325 * mem_cgroup ? And what type of charges should we move ?
327 unsigned long move_charge_at_immigrate
;
329 * set > 0 if pages under this cgroup are moving to other cgroup.
331 atomic_t moving_account
;
332 /* taken only while moving_account > 0 */
333 spinlock_t move_lock
;
337 struct mem_cgroup_stat_cpu __percpu
*stat
;
339 * used when a cpu is offlined or other synchronizations
340 * See mem_cgroup_read_stat().
342 struct mem_cgroup_stat_cpu nocpu_base
;
343 spinlock_t pcp_counter_lock
;
346 #if defined(CONFIG_MEMCG_KMEM) && defined(CONFIG_INET)
347 struct tcp_memcontrol tcp_mem
;
349 #if defined(CONFIG_MEMCG_KMEM)
350 /* analogous to slab_common's slab_caches list. per-memcg */
351 struct list_head memcg_slab_caches
;
352 /* Not a spinlock, we can take a lot of time walking the list */
353 struct mutex slab_caches_mutex
;
354 /* Index in the kmem_cache->memcg_params->memcg_caches array */
358 int last_scanned_node
;
360 nodemask_t scan_nodes
;
361 atomic_t numainfo_events
;
362 atomic_t numainfo_updating
;
365 struct mem_cgroup_per_node
*nodeinfo
[0];
366 /* WARNING: nodeinfo must be the last member here */
369 static size_t memcg_size(void)
371 return sizeof(struct mem_cgroup
) +
372 nr_node_ids
* sizeof(struct mem_cgroup_per_node
);
375 /* internal only representation about the status of kmem accounting. */
377 KMEM_ACCOUNTED_ACTIVE
= 0, /* accounted by this cgroup itself */
378 KMEM_ACCOUNTED_ACTIVATED
, /* static key enabled. */
379 KMEM_ACCOUNTED_DEAD
, /* dead memcg with pending kmem charges */
382 /* We account when limit is on, but only after call sites are patched */
383 #define KMEM_ACCOUNTED_MASK \
384 ((1 << KMEM_ACCOUNTED_ACTIVE) | (1 << KMEM_ACCOUNTED_ACTIVATED))
386 #ifdef CONFIG_MEMCG_KMEM
387 static inline void memcg_kmem_set_active(struct mem_cgroup
*memcg
)
389 set_bit(KMEM_ACCOUNTED_ACTIVE
, &memcg
->kmem_account_flags
);
392 static bool memcg_kmem_is_active(struct mem_cgroup
*memcg
)
394 return test_bit(KMEM_ACCOUNTED_ACTIVE
, &memcg
->kmem_account_flags
);
397 static void memcg_kmem_set_activated(struct mem_cgroup
*memcg
)
399 set_bit(KMEM_ACCOUNTED_ACTIVATED
, &memcg
->kmem_account_flags
);
402 static void memcg_kmem_clear_activated(struct mem_cgroup
*memcg
)
404 clear_bit(KMEM_ACCOUNTED_ACTIVATED
, &memcg
->kmem_account_flags
);
407 static void memcg_kmem_mark_dead(struct mem_cgroup
*memcg
)
409 if (test_bit(KMEM_ACCOUNTED_ACTIVE
, &memcg
->kmem_account_flags
))
410 set_bit(KMEM_ACCOUNTED_DEAD
, &memcg
->kmem_account_flags
);
413 static bool memcg_kmem_test_and_clear_dead(struct mem_cgroup
*memcg
)
415 return test_and_clear_bit(KMEM_ACCOUNTED_DEAD
,
416 &memcg
->kmem_account_flags
);
420 /* Stuffs for move charges at task migration. */
422 * Types of charges to be moved. "move_charge_at_immitgrate" and
423 * "immigrate_flags" are treated as a left-shifted bitmap of these types.
426 MOVE_CHARGE_TYPE_ANON
, /* private anonymous page and swap of it */
427 MOVE_CHARGE_TYPE_FILE
, /* file page(including tmpfs) and swap of it */
431 /* "mc" and its members are protected by cgroup_mutex */
432 static struct move_charge_struct
{
433 spinlock_t lock
; /* for from, to */
434 struct mem_cgroup
*from
;
435 struct mem_cgroup
*to
;
436 unsigned long immigrate_flags
;
437 unsigned long precharge
;
438 unsigned long moved_charge
;
439 unsigned long moved_swap
;
440 struct task_struct
*moving_task
; /* a task moving charges */
441 wait_queue_head_t waitq
; /* a waitq for other context */
443 .lock
= __SPIN_LOCK_UNLOCKED(mc
.lock
),
444 .waitq
= __WAIT_QUEUE_HEAD_INITIALIZER(mc
.waitq
),
447 static bool move_anon(void)
449 return test_bit(MOVE_CHARGE_TYPE_ANON
, &mc
.immigrate_flags
);
452 static bool move_file(void)
454 return test_bit(MOVE_CHARGE_TYPE_FILE
, &mc
.immigrate_flags
);
458 * Maximum loops in mem_cgroup_hierarchical_reclaim(), used for soft
459 * limit reclaim to prevent infinite loops, if they ever occur.
461 #define MEM_CGROUP_MAX_RECLAIM_LOOPS 100
462 #define MEM_CGROUP_MAX_SOFT_LIMIT_RECLAIM_LOOPS 2
465 MEM_CGROUP_CHARGE_TYPE_CACHE
= 0,
466 MEM_CGROUP_CHARGE_TYPE_ANON
,
467 MEM_CGROUP_CHARGE_TYPE_SWAPOUT
, /* for accounting swapcache */
468 MEM_CGROUP_CHARGE_TYPE_DROP
, /* a page was unused swap cache */
472 /* for encoding cft->private value on file */
480 #define MEMFILE_PRIVATE(x, val) ((x) << 16 | (val))
481 #define MEMFILE_TYPE(val) ((val) >> 16 & 0xffff)
482 #define MEMFILE_ATTR(val) ((val) & 0xffff)
483 /* Used for OOM nofiier */
484 #define OOM_CONTROL (0)
487 * Reclaim flags for mem_cgroup_hierarchical_reclaim
489 #define MEM_CGROUP_RECLAIM_NOSWAP_BIT 0x0
490 #define MEM_CGROUP_RECLAIM_NOSWAP (1 << MEM_CGROUP_RECLAIM_NOSWAP_BIT)
491 #define MEM_CGROUP_RECLAIM_SHRINK_BIT 0x1
492 #define MEM_CGROUP_RECLAIM_SHRINK (1 << MEM_CGROUP_RECLAIM_SHRINK_BIT)
495 * The memcg_create_mutex will be held whenever a new cgroup is created.
496 * As a consequence, any change that needs to protect against new child cgroups
497 * appearing has to hold it as well.
499 static DEFINE_MUTEX(memcg_create_mutex
);
501 static void mem_cgroup_get(struct mem_cgroup
*memcg
);
502 static void mem_cgroup_put(struct mem_cgroup
*memcg
);
505 struct mem_cgroup
*mem_cgroup_from_css(struct cgroup_subsys_state
*s
)
507 return container_of(s
, struct mem_cgroup
, css
);
510 /* Some nice accessors for the vmpressure. */
511 struct vmpressure
*memcg_to_vmpressure(struct mem_cgroup
*memcg
)
514 memcg
= root_mem_cgroup
;
515 return &memcg
->vmpressure
;
518 struct cgroup_subsys_state
*vmpressure_to_css(struct vmpressure
*vmpr
)
520 return &container_of(vmpr
, struct mem_cgroup
, vmpressure
)->css
;
523 struct vmpressure
*css_to_vmpressure(struct cgroup_subsys_state
*css
)
525 return &mem_cgroup_from_css(css
)->vmpressure
;
528 static inline bool mem_cgroup_is_root(struct mem_cgroup
*memcg
)
530 return (memcg
== root_mem_cgroup
);
533 /* Writing them here to avoid exposing memcg's inner layout */
534 #if defined(CONFIG_INET) && defined(CONFIG_MEMCG_KMEM)
536 void sock_update_memcg(struct sock
*sk
)
538 if (mem_cgroup_sockets_enabled
) {
539 struct mem_cgroup
*memcg
;
540 struct cg_proto
*cg_proto
;
542 BUG_ON(!sk
->sk_prot
->proto_cgroup
);
544 /* Socket cloning can throw us here with sk_cgrp already
545 * filled. It won't however, necessarily happen from
546 * process context. So the test for root memcg given
547 * the current task's memcg won't help us in this case.
549 * Respecting the original socket's memcg is a better
550 * decision in this case.
553 BUG_ON(mem_cgroup_is_root(sk
->sk_cgrp
->memcg
));
554 mem_cgroup_get(sk
->sk_cgrp
->memcg
);
559 memcg
= mem_cgroup_from_task(current
);
560 cg_proto
= sk
->sk_prot
->proto_cgroup(memcg
);
561 if (!mem_cgroup_is_root(memcg
) && memcg_proto_active(cg_proto
)) {
562 mem_cgroup_get(memcg
);
563 sk
->sk_cgrp
= cg_proto
;
568 EXPORT_SYMBOL(sock_update_memcg
);
570 void sock_release_memcg(struct sock
*sk
)
572 if (mem_cgroup_sockets_enabled
&& sk
->sk_cgrp
) {
573 struct mem_cgroup
*memcg
;
574 WARN_ON(!sk
->sk_cgrp
->memcg
);
575 memcg
= sk
->sk_cgrp
->memcg
;
576 mem_cgroup_put(memcg
);
580 struct cg_proto
*tcp_proto_cgroup(struct mem_cgroup
*memcg
)
582 if (!memcg
|| mem_cgroup_is_root(memcg
))
585 return &memcg
->tcp_mem
.cg_proto
;
587 EXPORT_SYMBOL(tcp_proto_cgroup
);
589 static void disarm_sock_keys(struct mem_cgroup
*memcg
)
591 if (!memcg_proto_activated(&memcg
->tcp_mem
.cg_proto
))
593 static_key_slow_dec(&memcg_socket_limit_enabled
);
596 static void disarm_sock_keys(struct mem_cgroup
*memcg
)
601 #ifdef CONFIG_MEMCG_KMEM
603 * This will be the memcg's index in each cache's ->memcg_params->memcg_caches.
604 * There are two main reasons for not using the css_id for this:
605 * 1) this works better in sparse environments, where we have a lot of memcgs,
606 * but only a few kmem-limited. Or also, if we have, for instance, 200
607 * memcgs, and none but the 200th is kmem-limited, we'd have to have a
608 * 200 entry array for that.
610 * 2) In order not to violate the cgroup API, we would like to do all memory
611 * allocation in ->create(). At that point, we haven't yet allocated the
612 * css_id. Having a separate index prevents us from messing with the cgroup
615 * The current size of the caches array is stored in
616 * memcg_limited_groups_array_size. It will double each time we have to
619 static DEFINE_IDA(kmem_limited_groups
);
620 int memcg_limited_groups_array_size
;
623 * MIN_SIZE is different than 1, because we would like to avoid going through
624 * the alloc/free process all the time. In a small machine, 4 kmem-limited
625 * cgroups is a reasonable guess. In the future, it could be a parameter or
626 * tunable, but that is strictly not necessary.
628 * MAX_SIZE should be as large as the number of css_ids. Ideally, we could get
629 * this constant directly from cgroup, but it is understandable that this is
630 * better kept as an internal representation in cgroup.c. In any case, the
631 * css_id space is not getting any smaller, and we don't have to necessarily
632 * increase ours as well if it increases.
634 #define MEMCG_CACHES_MIN_SIZE 4
635 #define MEMCG_CACHES_MAX_SIZE 65535
638 * A lot of the calls to the cache allocation functions are expected to be
639 * inlined by the compiler. Since the calls to memcg_kmem_get_cache are
640 * conditional to this static branch, we'll have to allow modules that does
641 * kmem_cache_alloc and the such to see this symbol as well
643 struct static_key memcg_kmem_enabled_key
;
644 EXPORT_SYMBOL(memcg_kmem_enabled_key
);
646 static void disarm_kmem_keys(struct mem_cgroup
*memcg
)
648 if (memcg_kmem_is_active(memcg
)) {
649 static_key_slow_dec(&memcg_kmem_enabled_key
);
650 ida_simple_remove(&kmem_limited_groups
, memcg
->kmemcg_id
);
653 * This check can't live in kmem destruction function,
654 * since the charges will outlive the cgroup
656 WARN_ON(res_counter_read_u64(&memcg
->kmem
, RES_USAGE
) != 0);
659 static void disarm_kmem_keys(struct mem_cgroup
*memcg
)
662 #endif /* CONFIG_MEMCG_KMEM */
664 static void disarm_static_keys(struct mem_cgroup
*memcg
)
666 disarm_sock_keys(memcg
);
667 disarm_kmem_keys(memcg
);
670 static void drain_all_stock_async(struct mem_cgroup
*memcg
);
672 static struct mem_cgroup_per_zone
*
673 mem_cgroup_zoneinfo(struct mem_cgroup
*memcg
, int nid
, int zid
)
675 VM_BUG_ON((unsigned)nid
>= nr_node_ids
);
676 return &memcg
->nodeinfo
[nid
]->zoneinfo
[zid
];
679 struct cgroup_subsys_state
*mem_cgroup_css(struct mem_cgroup
*memcg
)
684 static struct mem_cgroup_per_zone
*
685 page_cgroup_zoneinfo(struct mem_cgroup
*memcg
, struct page
*page
)
687 int nid
= page_to_nid(page
);
688 int zid
= page_zonenum(page
);
690 return mem_cgroup_zoneinfo(memcg
, nid
, zid
);
693 static struct mem_cgroup_tree_per_zone
*
694 soft_limit_tree_node_zone(int nid
, int zid
)
696 return &soft_limit_tree
.rb_tree_per_node
[nid
]->rb_tree_per_zone
[zid
];
699 static struct mem_cgroup_tree_per_zone
*
700 soft_limit_tree_from_page(struct page
*page
)
702 int nid
= page_to_nid(page
);
703 int zid
= page_zonenum(page
);
705 return &soft_limit_tree
.rb_tree_per_node
[nid
]->rb_tree_per_zone
[zid
];
709 __mem_cgroup_insert_exceeded(struct mem_cgroup
*memcg
,
710 struct mem_cgroup_per_zone
*mz
,
711 struct mem_cgroup_tree_per_zone
*mctz
,
712 unsigned long long new_usage_in_excess
)
714 struct rb_node
**p
= &mctz
->rb_root
.rb_node
;
715 struct rb_node
*parent
= NULL
;
716 struct mem_cgroup_per_zone
*mz_node
;
721 mz
->usage_in_excess
= new_usage_in_excess
;
722 if (!mz
->usage_in_excess
)
726 mz_node
= rb_entry(parent
, struct mem_cgroup_per_zone
,
728 if (mz
->usage_in_excess
< mz_node
->usage_in_excess
)
731 * We can't avoid mem cgroups that are over their soft
732 * limit by the same amount
734 else if (mz
->usage_in_excess
>= mz_node
->usage_in_excess
)
737 rb_link_node(&mz
->tree_node
, parent
, p
);
738 rb_insert_color(&mz
->tree_node
, &mctz
->rb_root
);
743 __mem_cgroup_remove_exceeded(struct mem_cgroup
*memcg
,
744 struct mem_cgroup_per_zone
*mz
,
745 struct mem_cgroup_tree_per_zone
*mctz
)
749 rb_erase(&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
)
758 spin_lock(&mctz
->lock
);
759 __mem_cgroup_remove_exceeded(memcg
, mz
, mctz
);
760 spin_unlock(&mctz
->lock
);
764 static void mem_cgroup_update_tree(struct mem_cgroup
*memcg
, struct page
*page
)
766 unsigned long long excess
;
767 struct mem_cgroup_per_zone
*mz
;
768 struct mem_cgroup_tree_per_zone
*mctz
;
769 int nid
= page_to_nid(page
);
770 int zid
= page_zonenum(page
);
771 mctz
= soft_limit_tree_from_page(page
);
774 * Necessary to update all ancestors when hierarchy is used.
775 * because their event counter is not touched.
777 for (; memcg
; memcg
= parent_mem_cgroup(memcg
)) {
778 mz
= mem_cgroup_zoneinfo(memcg
, nid
, zid
);
779 excess
= res_counter_soft_limit_excess(&memcg
->res
);
781 * We have to update the tree if mz is on RB-tree or
782 * mem is over its softlimit.
784 if (excess
|| mz
->on_tree
) {
785 spin_lock(&mctz
->lock
);
786 /* if on-tree, remove it */
788 __mem_cgroup_remove_exceeded(memcg
, mz
, mctz
);
790 * Insert again. mz->usage_in_excess will be updated.
791 * If excess is 0, no tree ops.
793 __mem_cgroup_insert_exceeded(memcg
, mz
, mctz
, excess
);
794 spin_unlock(&mctz
->lock
);
799 static void mem_cgroup_remove_from_trees(struct mem_cgroup
*memcg
)
802 struct mem_cgroup_per_zone
*mz
;
803 struct mem_cgroup_tree_per_zone
*mctz
;
805 for_each_node(node
) {
806 for (zone
= 0; zone
< MAX_NR_ZONES
; zone
++) {
807 mz
= mem_cgroup_zoneinfo(memcg
, node
, zone
);
808 mctz
= soft_limit_tree_node_zone(node
, zone
);
809 mem_cgroup_remove_exceeded(memcg
, mz
, mctz
);
814 static struct mem_cgroup_per_zone
*
815 __mem_cgroup_largest_soft_limit_node(struct mem_cgroup_tree_per_zone
*mctz
)
817 struct rb_node
*rightmost
= NULL
;
818 struct mem_cgroup_per_zone
*mz
;
822 rightmost
= rb_last(&mctz
->rb_root
);
824 goto done
; /* Nothing to reclaim from */
826 mz
= rb_entry(rightmost
, struct mem_cgroup_per_zone
, tree_node
);
828 * Remove the node now but someone else can add it back,
829 * we will to add it back at the end of reclaim to its correct
830 * position in the tree.
832 __mem_cgroup_remove_exceeded(mz
->memcg
, mz
, mctz
);
833 if (!res_counter_soft_limit_excess(&mz
->memcg
->res
) ||
834 !css_tryget(&mz
->memcg
->css
))
840 static struct mem_cgroup_per_zone
*
841 mem_cgroup_largest_soft_limit_node(struct mem_cgroup_tree_per_zone
*mctz
)
843 struct mem_cgroup_per_zone
*mz
;
845 spin_lock(&mctz
->lock
);
846 mz
= __mem_cgroup_largest_soft_limit_node(mctz
);
847 spin_unlock(&mctz
->lock
);
852 * Implementation Note: reading percpu statistics for memcg.
854 * Both of vmstat[] and percpu_counter has threshold and do periodic
855 * synchronization to implement "quick" read. There are trade-off between
856 * reading cost and precision of value. Then, we may have a chance to implement
857 * a periodic synchronizion of counter in memcg's counter.
859 * But this _read() function is used for user interface now. The user accounts
860 * memory usage by memory cgroup and he _always_ requires exact value because
861 * he accounts memory. Even if we provide quick-and-fuzzy read, we always
862 * have to visit all online cpus and make sum. So, for now, unnecessary
863 * synchronization is not implemented. (just implemented for cpu hotplug)
865 * If there are kernel internal actions which can make use of some not-exact
866 * value, and reading all cpu value can be performance bottleneck in some
867 * common workload, threashold and synchonization as vmstat[] should be
870 static long mem_cgroup_read_stat(struct mem_cgroup
*memcg
,
871 enum mem_cgroup_stat_index idx
)
877 for_each_online_cpu(cpu
)
878 val
+= per_cpu(memcg
->stat
->count
[idx
], cpu
);
879 #ifdef CONFIG_HOTPLUG_CPU
880 spin_lock(&memcg
->pcp_counter_lock
);
881 val
+= memcg
->nocpu_base
.count
[idx
];
882 spin_unlock(&memcg
->pcp_counter_lock
);
888 static void mem_cgroup_swap_statistics(struct mem_cgroup
*memcg
,
891 int val
= (charge
) ? 1 : -1;
892 this_cpu_add(memcg
->stat
->count
[MEM_CGROUP_STAT_SWAP
], val
);
895 static unsigned long mem_cgroup_read_events(struct mem_cgroup
*memcg
,
896 enum mem_cgroup_events_index idx
)
898 unsigned long val
= 0;
901 for_each_online_cpu(cpu
)
902 val
+= per_cpu(memcg
->stat
->events
[idx
], cpu
);
903 #ifdef CONFIG_HOTPLUG_CPU
904 spin_lock(&memcg
->pcp_counter_lock
);
905 val
+= memcg
->nocpu_base
.events
[idx
];
906 spin_unlock(&memcg
->pcp_counter_lock
);
911 static void mem_cgroup_charge_statistics(struct mem_cgroup
*memcg
,
913 bool anon
, int nr_pages
)
918 * Here, RSS means 'mapped anon' and anon's SwapCache. Shmem/tmpfs is
919 * counted as CACHE even if it's on ANON LRU.
922 __this_cpu_add(memcg
->stat
->count
[MEM_CGROUP_STAT_RSS
],
925 __this_cpu_add(memcg
->stat
->count
[MEM_CGROUP_STAT_CACHE
],
928 if (PageTransHuge(page
))
929 __this_cpu_add(memcg
->stat
->count
[MEM_CGROUP_STAT_RSS_HUGE
],
932 /* pagein of a big page is an event. So, ignore page size */
934 __this_cpu_inc(memcg
->stat
->events
[MEM_CGROUP_EVENTS_PGPGIN
]);
936 __this_cpu_inc(memcg
->stat
->events
[MEM_CGROUP_EVENTS_PGPGOUT
]);
937 nr_pages
= -nr_pages
; /* for event */
940 __this_cpu_add(memcg
->stat
->nr_page_events
, nr_pages
);
946 mem_cgroup_get_lru_size(struct lruvec
*lruvec
, enum lru_list lru
)
948 struct mem_cgroup_per_zone
*mz
;
950 mz
= container_of(lruvec
, struct mem_cgroup_per_zone
, lruvec
);
951 return mz
->lru_size
[lru
];
955 mem_cgroup_zone_nr_lru_pages(struct mem_cgroup
*memcg
, int nid
, int zid
,
956 unsigned int lru_mask
)
958 struct mem_cgroup_per_zone
*mz
;
960 unsigned long ret
= 0;
962 mz
= mem_cgroup_zoneinfo(memcg
, nid
, zid
);
965 if (BIT(lru
) & lru_mask
)
966 ret
+= mz
->lru_size
[lru
];
972 mem_cgroup_node_nr_lru_pages(struct mem_cgroup
*memcg
,
973 int nid
, unsigned int lru_mask
)
978 for (zid
= 0; zid
< MAX_NR_ZONES
; zid
++)
979 total
+= mem_cgroup_zone_nr_lru_pages(memcg
,
985 static unsigned long mem_cgroup_nr_lru_pages(struct mem_cgroup
*memcg
,
986 unsigned int lru_mask
)
991 for_each_node_state(nid
, N_MEMORY
)
992 total
+= mem_cgroup_node_nr_lru_pages(memcg
, nid
, lru_mask
);
996 static bool mem_cgroup_event_ratelimit(struct mem_cgroup
*memcg
,
997 enum mem_cgroup_events_target target
)
999 unsigned long val
, next
;
1001 val
= __this_cpu_read(memcg
->stat
->nr_page_events
);
1002 next
= __this_cpu_read(memcg
->stat
->targets
[target
]);
1003 /* from time_after() in jiffies.h */
1004 if ((long)next
- (long)val
< 0) {
1006 case MEM_CGROUP_TARGET_THRESH
:
1007 next
= val
+ THRESHOLDS_EVENTS_TARGET
;
1009 case MEM_CGROUP_TARGET_SOFTLIMIT
:
1010 next
= val
+ SOFTLIMIT_EVENTS_TARGET
;
1012 case MEM_CGROUP_TARGET_NUMAINFO
:
1013 next
= val
+ NUMAINFO_EVENTS_TARGET
;
1018 __this_cpu_write(memcg
->stat
->targets
[target
], next
);
1025 * Check events in order.
1028 static void memcg_check_events(struct mem_cgroup
*memcg
, struct page
*page
)
1031 /* threshold event is triggered in finer grain than soft limit */
1032 if (unlikely(mem_cgroup_event_ratelimit(memcg
,
1033 MEM_CGROUP_TARGET_THRESH
))) {
1035 bool do_numainfo __maybe_unused
;
1037 do_softlimit
= mem_cgroup_event_ratelimit(memcg
,
1038 MEM_CGROUP_TARGET_SOFTLIMIT
);
1039 #if MAX_NUMNODES > 1
1040 do_numainfo
= mem_cgroup_event_ratelimit(memcg
,
1041 MEM_CGROUP_TARGET_NUMAINFO
);
1045 mem_cgroup_threshold(memcg
);
1046 if (unlikely(do_softlimit
))
1047 mem_cgroup_update_tree(memcg
, page
);
1048 #if MAX_NUMNODES > 1
1049 if (unlikely(do_numainfo
))
1050 atomic_inc(&memcg
->numainfo_events
);
1056 struct mem_cgroup
*mem_cgroup_from_cont(struct cgroup
*cont
)
1058 return mem_cgroup_from_css(
1059 cgroup_subsys_state(cont
, mem_cgroup_subsys_id
));
1062 struct mem_cgroup
*mem_cgroup_from_task(struct task_struct
*p
)
1065 * mm_update_next_owner() may clear mm->owner to NULL
1066 * if it races with swapoff, page migration, etc.
1067 * So this can be called with p == NULL.
1072 return mem_cgroup_from_css(task_subsys_state(p
, mem_cgroup_subsys_id
));
1075 struct mem_cgroup
*try_get_mem_cgroup_from_mm(struct mm_struct
*mm
)
1077 struct mem_cgroup
*memcg
= NULL
;
1082 * Because we have no locks, mm->owner's may be being moved to other
1083 * cgroup. We use css_tryget() here even if this looks
1084 * pessimistic (rather than adding locks here).
1088 memcg
= mem_cgroup_from_task(rcu_dereference(mm
->owner
));
1089 if (unlikely(!memcg
))
1091 } while (!css_tryget(&memcg
->css
));
1097 * Returns a next (in a pre-order walk) alive memcg (with elevated css
1098 * ref. count) or NULL if the whole root's subtree has been visited.
1100 * helper function to be used by mem_cgroup_iter
1102 static struct mem_cgroup
*__mem_cgroup_iter_next(struct mem_cgroup
*root
,
1103 struct mem_cgroup
*last_visited
)
1105 struct cgroup
*prev_cgroup
, *next_cgroup
;
1108 * Root is not visited by cgroup iterators so it needs an
1114 prev_cgroup
= (last_visited
== root
) ? NULL
1115 : last_visited
->css
.cgroup
;
1117 next_cgroup
= cgroup_next_descendant_pre(
1118 prev_cgroup
, root
->css
.cgroup
);
1121 * Even if we found a group we have to make sure it is
1122 * alive. css && !memcg means that the groups should be
1123 * skipped and we should continue the tree walk.
1124 * last_visited css is safe to use because it is
1125 * protected by css_get and the tree walk is rcu safe.
1128 struct mem_cgroup
*mem
= mem_cgroup_from_cont(
1130 if (css_tryget(&mem
->css
))
1133 prev_cgroup
= next_cgroup
;
1141 static void mem_cgroup_iter_invalidate(struct mem_cgroup
*root
)
1144 * When a group in the hierarchy below root is destroyed, the
1145 * hierarchy iterator can no longer be trusted since it might
1146 * have pointed to the destroyed group. Invalidate it.
1148 atomic_inc(&root
->dead_count
);
1151 static struct mem_cgroup
*
1152 mem_cgroup_iter_load(struct mem_cgroup_reclaim_iter
*iter
,
1153 struct mem_cgroup
*root
,
1156 struct mem_cgroup
*position
= NULL
;
1158 * A cgroup destruction happens in two stages: offlining and
1159 * release. They are separated by a RCU grace period.
1161 * If the iterator is valid, we may still race with an
1162 * offlining. The RCU lock ensures the object won't be
1163 * released, tryget will fail if we lost the race.
1165 *sequence
= atomic_read(&root
->dead_count
);
1166 if (iter
->last_dead_count
== *sequence
) {
1168 position
= iter
->last_visited
;
1169 if (position
&& !css_tryget(&position
->css
))
1175 static void mem_cgroup_iter_update(struct mem_cgroup_reclaim_iter
*iter
,
1176 struct mem_cgroup
*last_visited
,
1177 struct mem_cgroup
*new_position
,
1181 css_put(&last_visited
->css
);
1183 * We store the sequence count from the time @last_visited was
1184 * loaded successfully instead of rereading it here so that we
1185 * don't lose destruction events in between. We could have
1186 * raced with the destruction of @new_position after all.
1188 iter
->last_visited
= new_position
;
1190 iter
->last_dead_count
= sequence
;
1194 * mem_cgroup_iter - iterate over memory cgroup hierarchy
1195 * @root: hierarchy root
1196 * @prev: previously returned memcg, NULL on first invocation
1197 * @reclaim: cookie for shared reclaim walks, NULL for full walks
1199 * Returns references to children of the hierarchy below @root, or
1200 * @root itself, or %NULL after a full round-trip.
1202 * Caller must pass the return value in @prev on subsequent
1203 * invocations for reference counting, or use mem_cgroup_iter_break()
1204 * to cancel a hierarchy walk before the round-trip is complete.
1206 * Reclaimers can specify a zone and a priority level in @reclaim to
1207 * divide up the memcgs in the hierarchy among all concurrent
1208 * reclaimers operating on the same zone and priority.
1210 struct mem_cgroup
*mem_cgroup_iter(struct mem_cgroup
*root
,
1211 struct mem_cgroup
*prev
,
1212 struct mem_cgroup_reclaim_cookie
*reclaim
)
1214 struct mem_cgroup
*memcg
= NULL
;
1215 struct mem_cgroup
*last_visited
= NULL
;
1217 if (mem_cgroup_disabled())
1221 root
= root_mem_cgroup
;
1223 if (prev
&& !reclaim
)
1224 last_visited
= prev
;
1226 if (!root
->use_hierarchy
&& root
!= root_mem_cgroup
) {
1234 struct mem_cgroup_reclaim_iter
*uninitialized_var(iter
);
1235 int uninitialized_var(seq
);
1238 int nid
= zone_to_nid(reclaim
->zone
);
1239 int zid
= zone_idx(reclaim
->zone
);
1240 struct mem_cgroup_per_zone
*mz
;
1242 mz
= mem_cgroup_zoneinfo(root
, nid
, zid
);
1243 iter
= &mz
->reclaim_iter
[reclaim
->priority
];
1244 if (prev
&& reclaim
->generation
!= iter
->generation
) {
1245 iter
->last_visited
= NULL
;
1249 last_visited
= mem_cgroup_iter_load(iter
, root
, &seq
);
1252 memcg
= __mem_cgroup_iter_next(root
, last_visited
);
1255 mem_cgroup_iter_update(iter
, last_visited
, memcg
, seq
);
1259 else if (!prev
&& memcg
)
1260 reclaim
->generation
= iter
->generation
;
1269 if (prev
&& prev
!= root
)
1270 css_put(&prev
->css
);
1276 * mem_cgroup_iter_break - abort a hierarchy walk prematurely
1277 * @root: hierarchy root
1278 * @prev: last visited hierarchy member as returned by mem_cgroup_iter()
1280 void mem_cgroup_iter_break(struct mem_cgroup
*root
,
1281 struct mem_cgroup
*prev
)
1284 root
= root_mem_cgroup
;
1285 if (prev
&& prev
!= root
)
1286 css_put(&prev
->css
);
1290 * Iteration constructs for visiting all cgroups (under a tree). If
1291 * loops are exited prematurely (break), mem_cgroup_iter_break() must
1292 * be used for reference counting.
1294 #define for_each_mem_cgroup_tree(iter, root) \
1295 for (iter = mem_cgroup_iter(root, NULL, NULL); \
1297 iter = mem_cgroup_iter(root, iter, NULL))
1299 #define for_each_mem_cgroup(iter) \
1300 for (iter = mem_cgroup_iter(NULL, NULL, NULL); \
1302 iter = mem_cgroup_iter(NULL, iter, NULL))
1304 void __mem_cgroup_count_vm_event(struct mm_struct
*mm
, enum vm_event_item idx
)
1306 struct mem_cgroup
*memcg
;
1309 memcg
= mem_cgroup_from_task(rcu_dereference(mm
->owner
));
1310 if (unlikely(!memcg
))
1315 this_cpu_inc(memcg
->stat
->events
[MEM_CGROUP_EVENTS_PGFAULT
]);
1318 this_cpu_inc(memcg
->stat
->events
[MEM_CGROUP_EVENTS_PGMAJFAULT
]);
1326 EXPORT_SYMBOL(__mem_cgroup_count_vm_event
);
1329 * mem_cgroup_zone_lruvec - get the lru list vector for a zone and memcg
1330 * @zone: zone of the wanted lruvec
1331 * @memcg: memcg of the wanted lruvec
1333 * Returns the lru list vector holding pages for the given @zone and
1334 * @mem. This can be the global zone lruvec, if the memory controller
1337 struct lruvec
*mem_cgroup_zone_lruvec(struct zone
*zone
,
1338 struct mem_cgroup
*memcg
)
1340 struct mem_cgroup_per_zone
*mz
;
1341 struct lruvec
*lruvec
;
1343 if (mem_cgroup_disabled()) {
1344 lruvec
= &zone
->lruvec
;
1348 mz
= mem_cgroup_zoneinfo(memcg
, zone_to_nid(zone
), zone_idx(zone
));
1349 lruvec
= &mz
->lruvec
;
1352 * Since a node can be onlined after the mem_cgroup was created,
1353 * we have to be prepared to initialize lruvec->zone here;
1354 * and if offlined then reonlined, we need to reinitialize it.
1356 if (unlikely(lruvec
->zone
!= zone
))
1357 lruvec
->zone
= zone
;
1362 * Following LRU functions are allowed to be used without PCG_LOCK.
1363 * Operations are called by routine of global LRU independently from memcg.
1364 * What we have to take care of here is validness of pc->mem_cgroup.
1366 * Changes to pc->mem_cgroup happens when
1369 * In typical case, "charge" is done before add-to-lru. Exception is SwapCache.
1370 * It is added to LRU before charge.
1371 * If PCG_USED bit is not set, page_cgroup is not added to this private LRU.
1372 * When moving account, the page is not on LRU. It's isolated.
1376 * mem_cgroup_page_lruvec - return lruvec for adding an lru page
1378 * @zone: zone of the page
1380 struct lruvec
*mem_cgroup_page_lruvec(struct page
*page
, struct zone
*zone
)
1382 struct mem_cgroup_per_zone
*mz
;
1383 struct mem_cgroup
*memcg
;
1384 struct page_cgroup
*pc
;
1385 struct lruvec
*lruvec
;
1387 if (mem_cgroup_disabled()) {
1388 lruvec
= &zone
->lruvec
;
1392 pc
= lookup_page_cgroup(page
);
1393 memcg
= pc
->mem_cgroup
;
1396 * Surreptitiously switch any uncharged offlist page to root:
1397 * an uncharged page off lru does nothing to secure
1398 * its former mem_cgroup from sudden removal.
1400 * Our caller holds lru_lock, and PageCgroupUsed is updated
1401 * under page_cgroup lock: between them, they make all uses
1402 * of pc->mem_cgroup safe.
1404 if (!PageLRU(page
) && !PageCgroupUsed(pc
) && memcg
!= root_mem_cgroup
)
1405 pc
->mem_cgroup
= memcg
= root_mem_cgroup
;
1407 mz
= page_cgroup_zoneinfo(memcg
, page
);
1408 lruvec
= &mz
->lruvec
;
1411 * Since a node can be onlined after the mem_cgroup was created,
1412 * we have to be prepared to initialize lruvec->zone here;
1413 * and if offlined then reonlined, we need to reinitialize it.
1415 if (unlikely(lruvec
->zone
!= zone
))
1416 lruvec
->zone
= zone
;
1421 * mem_cgroup_update_lru_size - account for adding or removing an lru page
1422 * @lruvec: mem_cgroup per zone lru vector
1423 * @lru: index of lru list the page is sitting on
1424 * @nr_pages: positive when adding or negative when removing
1426 * This function must be called when a page is added to or removed from an
1429 void mem_cgroup_update_lru_size(struct lruvec
*lruvec
, enum lru_list lru
,
1432 struct mem_cgroup_per_zone
*mz
;
1433 unsigned long *lru_size
;
1435 if (mem_cgroup_disabled())
1438 mz
= container_of(lruvec
, struct mem_cgroup_per_zone
, lruvec
);
1439 lru_size
= mz
->lru_size
+ lru
;
1440 *lru_size
+= nr_pages
;
1441 VM_BUG_ON((long)(*lru_size
) < 0);
1445 * Checks whether given mem is same or in the root_mem_cgroup's
1448 bool __mem_cgroup_same_or_subtree(const struct mem_cgroup
*root_memcg
,
1449 struct mem_cgroup
*memcg
)
1451 if (root_memcg
== memcg
)
1453 if (!root_memcg
->use_hierarchy
|| !memcg
)
1455 return css_is_ancestor(&memcg
->css
, &root_memcg
->css
);
1458 static bool mem_cgroup_same_or_subtree(const struct mem_cgroup
*root_memcg
,
1459 struct mem_cgroup
*memcg
)
1464 ret
= __mem_cgroup_same_or_subtree(root_memcg
, memcg
);
1469 bool task_in_mem_cgroup(struct task_struct
*task
,
1470 const struct mem_cgroup
*memcg
)
1472 struct mem_cgroup
*curr
= NULL
;
1473 struct task_struct
*p
;
1476 p
= find_lock_task_mm(task
);
1478 curr
= try_get_mem_cgroup_from_mm(p
->mm
);
1482 * All threads may have already detached their mm's, but the oom
1483 * killer still needs to detect if they have already been oom
1484 * killed to prevent needlessly killing additional tasks.
1487 curr
= mem_cgroup_from_task(task
);
1489 css_get(&curr
->css
);
1495 * We should check use_hierarchy of "memcg" not "curr". Because checking
1496 * use_hierarchy of "curr" here make this function true if hierarchy is
1497 * enabled in "curr" and "curr" is a child of "memcg" in *cgroup*
1498 * hierarchy(even if use_hierarchy is disabled in "memcg").
1500 ret
= mem_cgroup_same_or_subtree(memcg
, curr
);
1501 css_put(&curr
->css
);
1505 int mem_cgroup_inactive_anon_is_low(struct lruvec
*lruvec
)
1507 unsigned long inactive_ratio
;
1508 unsigned long inactive
;
1509 unsigned long active
;
1512 inactive
= mem_cgroup_get_lru_size(lruvec
, LRU_INACTIVE_ANON
);
1513 active
= mem_cgroup_get_lru_size(lruvec
, LRU_ACTIVE_ANON
);
1515 gb
= (inactive
+ active
) >> (30 - PAGE_SHIFT
);
1517 inactive_ratio
= int_sqrt(10 * gb
);
1521 return inactive
* inactive_ratio
< active
;
1524 #define mem_cgroup_from_res_counter(counter, member) \
1525 container_of(counter, struct mem_cgroup, member)
1528 * mem_cgroup_margin - calculate chargeable space of a memory cgroup
1529 * @memcg: the memory cgroup
1531 * Returns the maximum amount of memory @mem can be charged with, in
1534 static unsigned long mem_cgroup_margin(struct mem_cgroup
*memcg
)
1536 unsigned long long margin
;
1538 margin
= res_counter_margin(&memcg
->res
);
1539 if (do_swap_account
)
1540 margin
= min(margin
, res_counter_margin(&memcg
->memsw
));
1541 return margin
>> PAGE_SHIFT
;
1544 int mem_cgroup_swappiness(struct mem_cgroup
*memcg
)
1546 struct cgroup
*cgrp
= memcg
->css
.cgroup
;
1549 if (cgrp
->parent
== NULL
)
1550 return vm_swappiness
;
1552 return memcg
->swappiness
;
1556 * memcg->moving_account is used for checking possibility that some thread is
1557 * calling move_account(). When a thread on CPU-A starts moving pages under
1558 * a memcg, other threads should check memcg->moving_account under
1559 * rcu_read_lock(), like this:
1563 * memcg->moving_account+1 if (memcg->mocing_account)
1565 * synchronize_rcu() update something.
1570 /* for quick checking without looking up memcg */
1571 atomic_t memcg_moving __read_mostly
;
1573 static void mem_cgroup_start_move(struct mem_cgroup
*memcg
)
1575 atomic_inc(&memcg_moving
);
1576 atomic_inc(&memcg
->moving_account
);
1580 static void mem_cgroup_end_move(struct mem_cgroup
*memcg
)
1583 * Now, mem_cgroup_clear_mc() may call this function with NULL.
1584 * We check NULL in callee rather than caller.
1587 atomic_dec(&memcg_moving
);
1588 atomic_dec(&memcg
->moving_account
);
1593 * 2 routines for checking "mem" is under move_account() or not.
1595 * mem_cgroup_stolen() - checking whether a cgroup is mc.from or not. This
1596 * is used for avoiding races in accounting. If true,
1597 * pc->mem_cgroup may be overwritten.
1599 * mem_cgroup_under_move() - checking a cgroup is mc.from or mc.to or
1600 * under hierarchy of moving cgroups. This is for
1601 * waiting at hith-memory prressure caused by "move".
1604 static bool mem_cgroup_stolen(struct mem_cgroup
*memcg
)
1606 VM_BUG_ON(!rcu_read_lock_held());
1607 return atomic_read(&memcg
->moving_account
) > 0;
1610 static bool mem_cgroup_under_move(struct mem_cgroup
*memcg
)
1612 struct mem_cgroup
*from
;
1613 struct mem_cgroup
*to
;
1616 * Unlike task_move routines, we access mc.to, mc.from not under
1617 * mutual exclusion by cgroup_mutex. Here, we take spinlock instead.
1619 spin_lock(&mc
.lock
);
1625 ret
= mem_cgroup_same_or_subtree(memcg
, from
)
1626 || mem_cgroup_same_or_subtree(memcg
, to
);
1628 spin_unlock(&mc
.lock
);
1632 static bool mem_cgroup_wait_acct_move(struct mem_cgroup
*memcg
)
1634 if (mc
.moving_task
&& current
!= mc
.moving_task
) {
1635 if (mem_cgroup_under_move(memcg
)) {
1637 prepare_to_wait(&mc
.waitq
, &wait
, TASK_INTERRUPTIBLE
);
1638 /* moving charge context might have finished. */
1641 finish_wait(&mc
.waitq
, &wait
);
1649 * Take this lock when
1650 * - a code tries to modify page's memcg while it's USED.
1651 * - a code tries to modify page state accounting in a memcg.
1652 * see mem_cgroup_stolen(), too.
1654 static void move_lock_mem_cgroup(struct mem_cgroup
*memcg
,
1655 unsigned long *flags
)
1657 spin_lock_irqsave(&memcg
->move_lock
, *flags
);
1660 static void move_unlock_mem_cgroup(struct mem_cgroup
*memcg
,
1661 unsigned long *flags
)
1663 spin_unlock_irqrestore(&memcg
->move_lock
, *flags
);
1666 #define K(x) ((x) << (PAGE_SHIFT-10))
1668 * mem_cgroup_print_oom_info: Print OOM information relevant to memory controller.
1669 * @memcg: The memory cgroup that went over limit
1670 * @p: Task that is going to be killed
1672 * NOTE: @memcg and @p's mem_cgroup can be different when hierarchy is
1675 void mem_cgroup_print_oom_info(struct mem_cgroup
*memcg
, struct task_struct
*p
)
1677 struct cgroup
*task_cgrp
;
1678 struct cgroup
*mem_cgrp
;
1680 * Need a buffer in BSS, can't rely on allocations. The code relies
1681 * on the assumption that OOM is serialized for memory controller.
1682 * If this assumption is broken, revisit this code.
1684 static char memcg_name
[PATH_MAX
];
1686 struct mem_cgroup
*iter
;
1694 mem_cgrp
= memcg
->css
.cgroup
;
1695 task_cgrp
= task_cgroup(p
, mem_cgroup_subsys_id
);
1697 ret
= cgroup_path(task_cgrp
, memcg_name
, PATH_MAX
);
1700 * Unfortunately, we are unable to convert to a useful name
1701 * But we'll still print out the usage information
1708 pr_info("Task in %s killed", memcg_name
);
1711 ret
= cgroup_path(mem_cgrp
, memcg_name
, PATH_MAX
);
1719 * Continues from above, so we don't need an KERN_ level
1721 pr_cont(" as a result of limit of %s\n", memcg_name
);
1724 pr_info("memory: usage %llukB, limit %llukB, failcnt %llu\n",
1725 res_counter_read_u64(&memcg
->res
, RES_USAGE
) >> 10,
1726 res_counter_read_u64(&memcg
->res
, RES_LIMIT
) >> 10,
1727 res_counter_read_u64(&memcg
->res
, RES_FAILCNT
));
1728 pr_info("memory+swap: usage %llukB, limit %llukB, failcnt %llu\n",
1729 res_counter_read_u64(&memcg
->memsw
, RES_USAGE
) >> 10,
1730 res_counter_read_u64(&memcg
->memsw
, RES_LIMIT
) >> 10,
1731 res_counter_read_u64(&memcg
->memsw
, RES_FAILCNT
));
1732 pr_info("kmem: usage %llukB, limit %llukB, failcnt %llu\n",
1733 res_counter_read_u64(&memcg
->kmem
, RES_USAGE
) >> 10,
1734 res_counter_read_u64(&memcg
->kmem
, RES_LIMIT
) >> 10,
1735 res_counter_read_u64(&memcg
->kmem
, RES_FAILCNT
));
1737 for_each_mem_cgroup_tree(iter
, memcg
) {
1738 pr_info("Memory cgroup stats");
1741 ret
= cgroup_path(iter
->css
.cgroup
, memcg_name
, PATH_MAX
);
1743 pr_cont(" for %s", memcg_name
);
1747 for (i
= 0; i
< MEM_CGROUP_STAT_NSTATS
; i
++) {
1748 if (i
== MEM_CGROUP_STAT_SWAP
&& !do_swap_account
)
1750 pr_cont(" %s:%ldKB", mem_cgroup_stat_names
[i
],
1751 K(mem_cgroup_read_stat(iter
, i
)));
1754 for (i
= 0; i
< NR_LRU_LISTS
; i
++)
1755 pr_cont(" %s:%luKB", mem_cgroup_lru_names
[i
],
1756 K(mem_cgroup_nr_lru_pages(iter
, BIT(i
))));
1763 * This function returns the number of memcg under hierarchy tree. Returns
1764 * 1(self count) if no children.
1766 static int mem_cgroup_count_children(struct mem_cgroup
*memcg
)
1769 struct mem_cgroup
*iter
;
1771 for_each_mem_cgroup_tree(iter
, memcg
)
1777 * Return the memory (and swap, if configured) limit for a memcg.
1779 static u64
mem_cgroup_get_limit(struct mem_cgroup
*memcg
)
1783 limit
= res_counter_read_u64(&memcg
->res
, RES_LIMIT
);
1786 * Do not consider swap space if we cannot swap due to swappiness
1788 if (mem_cgroup_swappiness(memcg
)) {
1791 limit
+= total_swap_pages
<< PAGE_SHIFT
;
1792 memsw
= res_counter_read_u64(&memcg
->memsw
, RES_LIMIT
);
1795 * If memsw is finite and limits the amount of swap space
1796 * available to this memcg, return that limit.
1798 limit
= min(limit
, memsw
);
1804 static void mem_cgroup_out_of_memory(struct mem_cgroup
*memcg
, gfp_t gfp_mask
,
1807 struct mem_cgroup
*iter
;
1808 unsigned long chosen_points
= 0;
1809 unsigned long totalpages
;
1810 unsigned int points
= 0;
1811 struct task_struct
*chosen
= NULL
;
1814 * If current has a pending SIGKILL or is exiting, then automatically
1815 * select it. The goal is to allow it to allocate so that it may
1816 * quickly exit and free its memory.
1818 if (fatal_signal_pending(current
) || current
->flags
& PF_EXITING
) {
1819 set_thread_flag(TIF_MEMDIE
);
1823 check_panic_on_oom(CONSTRAINT_MEMCG
, gfp_mask
, order
, NULL
);
1824 totalpages
= mem_cgroup_get_limit(memcg
) >> PAGE_SHIFT
? : 1;
1825 for_each_mem_cgroup_tree(iter
, memcg
) {
1826 struct cgroup
*cgroup
= iter
->css
.cgroup
;
1827 struct cgroup_iter it
;
1828 struct task_struct
*task
;
1830 cgroup_iter_start(cgroup
, &it
);
1831 while ((task
= cgroup_iter_next(cgroup
, &it
))) {
1832 switch (oom_scan_process_thread(task
, totalpages
, NULL
,
1834 case OOM_SCAN_SELECT
:
1836 put_task_struct(chosen
);
1838 chosen_points
= ULONG_MAX
;
1839 get_task_struct(chosen
);
1841 case OOM_SCAN_CONTINUE
:
1843 case OOM_SCAN_ABORT
:
1844 cgroup_iter_end(cgroup
, &it
);
1845 mem_cgroup_iter_break(memcg
, iter
);
1847 put_task_struct(chosen
);
1852 points
= oom_badness(task
, memcg
, NULL
, totalpages
);
1853 if (points
> chosen_points
) {
1855 put_task_struct(chosen
);
1857 chosen_points
= points
;
1858 get_task_struct(chosen
);
1861 cgroup_iter_end(cgroup
, &it
);
1866 points
= chosen_points
* 1000 / totalpages
;
1867 oom_kill_process(chosen
, gfp_mask
, order
, points
, totalpages
, memcg
,
1868 NULL
, "Memory cgroup out of memory");
1871 static unsigned long mem_cgroup_reclaim(struct mem_cgroup
*memcg
,
1873 unsigned long flags
)
1875 unsigned long total
= 0;
1876 bool noswap
= false;
1879 if (flags
& MEM_CGROUP_RECLAIM_NOSWAP
)
1881 if (!(flags
& MEM_CGROUP_RECLAIM_SHRINK
) && memcg
->memsw_is_minimum
)
1884 for (loop
= 0; loop
< MEM_CGROUP_MAX_RECLAIM_LOOPS
; loop
++) {
1886 drain_all_stock_async(memcg
);
1887 total
+= try_to_free_mem_cgroup_pages(memcg
, gfp_mask
, noswap
);
1889 * Allow limit shrinkers, which are triggered directly
1890 * by userspace, to catch signals and stop reclaim
1891 * after minimal progress, regardless of the margin.
1893 if (total
&& (flags
& MEM_CGROUP_RECLAIM_SHRINK
))
1895 if (mem_cgroup_margin(memcg
))
1898 * If nothing was reclaimed after two attempts, there
1899 * may be no reclaimable pages in this hierarchy.
1908 * test_mem_cgroup_node_reclaimable
1909 * @memcg: the target memcg
1910 * @nid: the node ID to be checked.
1911 * @noswap : specify true here if the user wants flle only information.
1913 * This function returns whether the specified memcg contains any
1914 * reclaimable pages on a node. Returns true if there are any reclaimable
1915 * pages in the node.
1917 static bool test_mem_cgroup_node_reclaimable(struct mem_cgroup
*memcg
,
1918 int nid
, bool noswap
)
1920 if (mem_cgroup_node_nr_lru_pages(memcg
, nid
, LRU_ALL_FILE
))
1922 if (noswap
|| !total_swap_pages
)
1924 if (mem_cgroup_node_nr_lru_pages(memcg
, nid
, LRU_ALL_ANON
))
1929 #if MAX_NUMNODES > 1
1932 * Always updating the nodemask is not very good - even if we have an empty
1933 * list or the wrong list here, we can start from some node and traverse all
1934 * nodes based on the zonelist. So update the list loosely once per 10 secs.
1937 static void mem_cgroup_may_update_nodemask(struct mem_cgroup
*memcg
)
1941 * numainfo_events > 0 means there was at least NUMAINFO_EVENTS_TARGET
1942 * pagein/pageout changes since the last update.
1944 if (!atomic_read(&memcg
->numainfo_events
))
1946 if (atomic_inc_return(&memcg
->numainfo_updating
) > 1)
1949 /* make a nodemask where this memcg uses memory from */
1950 memcg
->scan_nodes
= node_states
[N_MEMORY
];
1952 for_each_node_mask(nid
, node_states
[N_MEMORY
]) {
1954 if (!test_mem_cgroup_node_reclaimable(memcg
, nid
, false))
1955 node_clear(nid
, memcg
->scan_nodes
);
1958 atomic_set(&memcg
->numainfo_events
, 0);
1959 atomic_set(&memcg
->numainfo_updating
, 0);
1963 * Selecting a node where we start reclaim from. Because what we need is just
1964 * reducing usage counter, start from anywhere is O,K. Considering
1965 * memory reclaim from current node, there are pros. and cons.
1967 * Freeing memory from current node means freeing memory from a node which
1968 * we'll use or we've used. So, it may make LRU bad. And if several threads
1969 * hit limits, it will see a contention on a node. But freeing from remote
1970 * node means more costs for memory reclaim because of memory latency.
1972 * Now, we use round-robin. Better algorithm is welcomed.
1974 int mem_cgroup_select_victim_node(struct mem_cgroup
*memcg
)
1978 mem_cgroup_may_update_nodemask(memcg
);
1979 node
= memcg
->last_scanned_node
;
1981 node
= next_node(node
, memcg
->scan_nodes
);
1982 if (node
== MAX_NUMNODES
)
1983 node
= first_node(memcg
->scan_nodes
);
1985 * We call this when we hit limit, not when pages are added to LRU.
1986 * No LRU may hold pages because all pages are UNEVICTABLE or
1987 * memcg is too small and all pages are not on LRU. In that case,
1988 * we use curret node.
1990 if (unlikely(node
== MAX_NUMNODES
))
1991 node
= numa_node_id();
1993 memcg
->last_scanned_node
= node
;
1998 * Check all nodes whether it contains reclaimable pages or not.
1999 * For quick scan, we make use of scan_nodes. This will allow us to skip
2000 * unused nodes. But scan_nodes is lazily updated and may not cotain
2001 * enough new information. We need to do double check.
2003 static bool mem_cgroup_reclaimable(struct mem_cgroup
*memcg
, bool noswap
)
2008 * quick check...making use of scan_node.
2009 * We can skip unused nodes.
2011 if (!nodes_empty(memcg
->scan_nodes
)) {
2012 for (nid
= first_node(memcg
->scan_nodes
);
2014 nid
= next_node(nid
, memcg
->scan_nodes
)) {
2016 if (test_mem_cgroup_node_reclaimable(memcg
, nid
, noswap
))
2021 * Check rest of nodes.
2023 for_each_node_state(nid
, N_MEMORY
) {
2024 if (node_isset(nid
, memcg
->scan_nodes
))
2026 if (test_mem_cgroup_node_reclaimable(memcg
, nid
, noswap
))
2033 int mem_cgroup_select_victim_node(struct mem_cgroup
*memcg
)
2038 static bool mem_cgroup_reclaimable(struct mem_cgroup
*memcg
, bool noswap
)
2040 return test_mem_cgroup_node_reclaimable(memcg
, 0, noswap
);
2044 static int mem_cgroup_soft_reclaim(struct mem_cgroup
*root_memcg
,
2047 unsigned long *total_scanned
)
2049 struct mem_cgroup
*victim
= NULL
;
2052 unsigned long excess
;
2053 unsigned long nr_scanned
;
2054 struct mem_cgroup_reclaim_cookie reclaim
= {
2059 excess
= res_counter_soft_limit_excess(&root_memcg
->res
) >> PAGE_SHIFT
;
2062 victim
= mem_cgroup_iter(root_memcg
, victim
, &reclaim
);
2067 * If we have not been able to reclaim
2068 * anything, it might because there are
2069 * no reclaimable pages under this hierarchy
2074 * We want to do more targeted reclaim.
2075 * excess >> 2 is not to excessive so as to
2076 * reclaim too much, nor too less that we keep
2077 * coming back to reclaim from this cgroup
2079 if (total
>= (excess
>> 2) ||
2080 (loop
> MEM_CGROUP_MAX_RECLAIM_LOOPS
))
2085 if (!mem_cgroup_reclaimable(victim
, false))
2087 total
+= mem_cgroup_shrink_node_zone(victim
, gfp_mask
, false,
2089 *total_scanned
+= nr_scanned
;
2090 if (!res_counter_soft_limit_excess(&root_memcg
->res
))
2093 mem_cgroup_iter_break(root_memcg
, victim
);
2098 * Check OOM-Killer is already running under our hierarchy.
2099 * If someone is running, return false.
2100 * Has to be called with memcg_oom_lock
2102 static bool mem_cgroup_oom_lock(struct mem_cgroup
*memcg
)
2104 struct mem_cgroup
*iter
, *failed
= NULL
;
2106 for_each_mem_cgroup_tree(iter
, memcg
) {
2107 if (iter
->oom_lock
) {
2109 * this subtree of our hierarchy is already locked
2110 * so we cannot give a lock.
2113 mem_cgroup_iter_break(memcg
, iter
);
2116 iter
->oom_lock
= true;
2123 * OK, we failed to lock the whole subtree so we have to clean up
2124 * what we set up to the failing subtree
2126 for_each_mem_cgroup_tree(iter
, memcg
) {
2127 if (iter
== failed
) {
2128 mem_cgroup_iter_break(memcg
, iter
);
2131 iter
->oom_lock
= false;
2137 * Has to be called with memcg_oom_lock
2139 static int mem_cgroup_oom_unlock(struct mem_cgroup
*memcg
)
2141 struct mem_cgroup
*iter
;
2143 for_each_mem_cgroup_tree(iter
, memcg
)
2144 iter
->oom_lock
= false;
2148 static void mem_cgroup_mark_under_oom(struct mem_cgroup
*memcg
)
2150 struct mem_cgroup
*iter
;
2152 for_each_mem_cgroup_tree(iter
, memcg
)
2153 atomic_inc(&iter
->under_oom
);
2156 static void mem_cgroup_unmark_under_oom(struct mem_cgroup
*memcg
)
2158 struct mem_cgroup
*iter
;
2161 * When a new child is created while the hierarchy is under oom,
2162 * mem_cgroup_oom_lock() may not be called. We have to use
2163 * atomic_add_unless() here.
2165 for_each_mem_cgroup_tree(iter
, memcg
)
2166 atomic_add_unless(&iter
->under_oom
, -1, 0);
2169 static DEFINE_SPINLOCK(memcg_oom_lock
);
2170 static DECLARE_WAIT_QUEUE_HEAD(memcg_oom_waitq
);
2172 struct oom_wait_info
{
2173 struct mem_cgroup
*memcg
;
2177 static int memcg_oom_wake_function(wait_queue_t
*wait
,
2178 unsigned mode
, int sync
, void *arg
)
2180 struct mem_cgroup
*wake_memcg
= (struct mem_cgroup
*)arg
;
2181 struct mem_cgroup
*oom_wait_memcg
;
2182 struct oom_wait_info
*oom_wait_info
;
2184 oom_wait_info
= container_of(wait
, struct oom_wait_info
, wait
);
2185 oom_wait_memcg
= oom_wait_info
->memcg
;
2188 * Both of oom_wait_info->memcg and wake_memcg are stable under us.
2189 * Then we can use css_is_ancestor without taking care of RCU.
2191 if (!mem_cgroup_same_or_subtree(oom_wait_memcg
, wake_memcg
)
2192 && !mem_cgroup_same_or_subtree(wake_memcg
, oom_wait_memcg
))
2194 return autoremove_wake_function(wait
, mode
, sync
, arg
);
2197 static void memcg_wakeup_oom(struct mem_cgroup
*memcg
)
2199 /* for filtering, pass "memcg" as argument. */
2200 __wake_up(&memcg_oom_waitq
, TASK_NORMAL
, 0, memcg
);
2203 static void memcg_oom_recover(struct mem_cgroup
*memcg
)
2205 if (memcg
&& atomic_read(&memcg
->under_oom
))
2206 memcg_wakeup_oom(memcg
);
2210 * try to call OOM killer. returns false if we should exit memory-reclaim loop.
2212 static bool mem_cgroup_handle_oom(struct mem_cgroup
*memcg
, gfp_t mask
,
2215 struct oom_wait_info owait
;
2216 bool locked
, need_to_kill
;
2218 owait
.memcg
= memcg
;
2219 owait
.wait
.flags
= 0;
2220 owait
.wait
.func
= memcg_oom_wake_function
;
2221 owait
.wait
.private = current
;
2222 INIT_LIST_HEAD(&owait
.wait
.task_list
);
2223 need_to_kill
= true;
2224 mem_cgroup_mark_under_oom(memcg
);
2226 /* At first, try to OOM lock hierarchy under memcg.*/
2227 spin_lock(&memcg_oom_lock
);
2228 locked
= mem_cgroup_oom_lock(memcg
);
2230 * Even if signal_pending(), we can't quit charge() loop without
2231 * accounting. So, UNINTERRUPTIBLE is appropriate. But SIGKILL
2232 * under OOM is always welcomed, use TASK_KILLABLE here.
2234 prepare_to_wait(&memcg_oom_waitq
, &owait
.wait
, TASK_KILLABLE
);
2235 if (!locked
|| memcg
->oom_kill_disable
)
2236 need_to_kill
= false;
2238 mem_cgroup_oom_notify(memcg
);
2239 spin_unlock(&memcg_oom_lock
);
2242 finish_wait(&memcg_oom_waitq
, &owait
.wait
);
2243 mem_cgroup_out_of_memory(memcg
, mask
, order
);
2246 finish_wait(&memcg_oom_waitq
, &owait
.wait
);
2248 spin_lock(&memcg_oom_lock
);
2250 mem_cgroup_oom_unlock(memcg
);
2251 memcg_wakeup_oom(memcg
);
2252 spin_unlock(&memcg_oom_lock
);
2254 mem_cgroup_unmark_under_oom(memcg
);
2256 if (test_thread_flag(TIF_MEMDIE
) || fatal_signal_pending(current
))
2258 /* Give chance to dying process */
2259 schedule_timeout_uninterruptible(1);
2264 * Currently used to update mapped file statistics, but the routine can be
2265 * generalized to update other statistics as well.
2267 * Notes: Race condition
2269 * We usually use page_cgroup_lock() for accessing page_cgroup member but
2270 * it tends to be costly. But considering some conditions, we doesn't need
2271 * to do so _always_.
2273 * Considering "charge", lock_page_cgroup() is not required because all
2274 * file-stat operations happen after a page is attached to radix-tree. There
2275 * are no race with "charge".
2277 * Considering "uncharge", we know that memcg doesn't clear pc->mem_cgroup
2278 * at "uncharge" intentionally. So, we always see valid pc->mem_cgroup even
2279 * if there are race with "uncharge". Statistics itself is properly handled
2282 * Considering "move", this is an only case we see a race. To make the race
2283 * small, we check mm->moving_account and detect there are possibility of race
2284 * If there is, we take a lock.
2287 void __mem_cgroup_begin_update_page_stat(struct page
*page
,
2288 bool *locked
, unsigned long *flags
)
2290 struct mem_cgroup
*memcg
;
2291 struct page_cgroup
*pc
;
2293 pc
= lookup_page_cgroup(page
);
2295 memcg
= pc
->mem_cgroup
;
2296 if (unlikely(!memcg
|| !PageCgroupUsed(pc
)))
2299 * If this memory cgroup is not under account moving, we don't
2300 * need to take move_lock_mem_cgroup(). Because we already hold
2301 * rcu_read_lock(), any calls to move_account will be delayed until
2302 * rcu_read_unlock() if mem_cgroup_stolen() == true.
2304 if (!mem_cgroup_stolen(memcg
))
2307 move_lock_mem_cgroup(memcg
, flags
);
2308 if (memcg
!= pc
->mem_cgroup
|| !PageCgroupUsed(pc
)) {
2309 move_unlock_mem_cgroup(memcg
, flags
);
2315 void __mem_cgroup_end_update_page_stat(struct page
*page
, unsigned long *flags
)
2317 struct page_cgroup
*pc
= lookup_page_cgroup(page
);
2320 * It's guaranteed that pc->mem_cgroup never changes while
2321 * lock is held because a routine modifies pc->mem_cgroup
2322 * should take move_lock_mem_cgroup().
2324 move_unlock_mem_cgroup(pc
->mem_cgroup
, flags
);
2327 void mem_cgroup_update_page_stat(struct page
*page
,
2328 enum mem_cgroup_page_stat_item idx
, int val
)
2330 struct mem_cgroup
*memcg
;
2331 struct page_cgroup
*pc
= lookup_page_cgroup(page
);
2332 unsigned long uninitialized_var(flags
);
2334 if (mem_cgroup_disabled())
2337 memcg
= pc
->mem_cgroup
;
2338 if (unlikely(!memcg
|| !PageCgroupUsed(pc
)))
2342 case MEMCG_NR_FILE_MAPPED
:
2343 idx
= MEM_CGROUP_STAT_FILE_MAPPED
;
2349 this_cpu_add(memcg
->stat
->count
[idx
], val
);
2353 * size of first charge trial. "32" comes from vmscan.c's magic value.
2354 * TODO: maybe necessary to use big numbers in big irons.
2356 #define CHARGE_BATCH 32U
2357 struct memcg_stock_pcp
{
2358 struct mem_cgroup
*cached
; /* this never be root cgroup */
2359 unsigned int nr_pages
;
2360 struct work_struct work
;
2361 unsigned long flags
;
2362 #define FLUSHING_CACHED_CHARGE 0
2364 static DEFINE_PER_CPU(struct memcg_stock_pcp
, memcg_stock
);
2365 static DEFINE_MUTEX(percpu_charge_mutex
);
2368 * consume_stock: Try to consume stocked charge on this cpu.
2369 * @memcg: memcg to consume from.
2370 * @nr_pages: how many pages to charge.
2372 * The charges will only happen if @memcg matches the current cpu's memcg
2373 * stock, and at least @nr_pages are available in that stock. Failure to
2374 * service an allocation will refill the stock.
2376 * returns true if successful, false otherwise.
2378 static bool consume_stock(struct mem_cgroup
*memcg
, unsigned int nr_pages
)
2380 struct memcg_stock_pcp
*stock
;
2383 if (nr_pages
> CHARGE_BATCH
)
2386 stock
= &get_cpu_var(memcg_stock
);
2387 if (memcg
== stock
->cached
&& stock
->nr_pages
>= nr_pages
)
2388 stock
->nr_pages
-= nr_pages
;
2389 else /* need to call res_counter_charge */
2391 put_cpu_var(memcg_stock
);
2396 * Returns stocks cached in percpu to res_counter and reset cached information.
2398 static void drain_stock(struct memcg_stock_pcp
*stock
)
2400 struct mem_cgroup
*old
= stock
->cached
;
2402 if (stock
->nr_pages
) {
2403 unsigned long bytes
= stock
->nr_pages
* PAGE_SIZE
;
2405 res_counter_uncharge(&old
->res
, bytes
);
2406 if (do_swap_account
)
2407 res_counter_uncharge(&old
->memsw
, bytes
);
2408 stock
->nr_pages
= 0;
2410 stock
->cached
= NULL
;
2414 * This must be called under preempt disabled or must be called by
2415 * a thread which is pinned to local cpu.
2417 static void drain_local_stock(struct work_struct
*dummy
)
2419 struct memcg_stock_pcp
*stock
= &__get_cpu_var(memcg_stock
);
2421 clear_bit(FLUSHING_CACHED_CHARGE
, &stock
->flags
);
2424 static void __init
memcg_stock_init(void)
2428 for_each_possible_cpu(cpu
) {
2429 struct memcg_stock_pcp
*stock
=
2430 &per_cpu(memcg_stock
, cpu
);
2431 INIT_WORK(&stock
->work
, drain_local_stock
);
2436 * Cache charges(val) which is from res_counter, to local per_cpu area.
2437 * This will be consumed by consume_stock() function, later.
2439 static void refill_stock(struct mem_cgroup
*memcg
, unsigned int nr_pages
)
2441 struct memcg_stock_pcp
*stock
= &get_cpu_var(memcg_stock
);
2443 if (stock
->cached
!= memcg
) { /* reset if necessary */
2445 stock
->cached
= memcg
;
2447 stock
->nr_pages
+= nr_pages
;
2448 put_cpu_var(memcg_stock
);
2452 * Drains all per-CPU charge caches for given root_memcg resp. subtree
2453 * of the hierarchy under it. sync flag says whether we should block
2454 * until the work is done.
2456 static void drain_all_stock(struct mem_cgroup
*root_memcg
, bool sync
)
2460 /* Notify other cpus that system-wide "drain" is running */
2463 for_each_online_cpu(cpu
) {
2464 struct memcg_stock_pcp
*stock
= &per_cpu(memcg_stock
, cpu
);
2465 struct mem_cgroup
*memcg
;
2467 memcg
= stock
->cached
;
2468 if (!memcg
|| !stock
->nr_pages
)
2470 if (!mem_cgroup_same_or_subtree(root_memcg
, memcg
))
2472 if (!test_and_set_bit(FLUSHING_CACHED_CHARGE
, &stock
->flags
)) {
2474 drain_local_stock(&stock
->work
);
2476 schedule_work_on(cpu
, &stock
->work
);
2484 for_each_online_cpu(cpu
) {
2485 struct memcg_stock_pcp
*stock
= &per_cpu(memcg_stock
, cpu
);
2486 if (test_bit(FLUSHING_CACHED_CHARGE
, &stock
->flags
))
2487 flush_work(&stock
->work
);
2494 * Tries to drain stocked charges in other cpus. This function is asynchronous
2495 * and just put a work per cpu for draining localy on each cpu. Caller can
2496 * expects some charges will be back to res_counter later but cannot wait for
2499 static void drain_all_stock_async(struct mem_cgroup
*root_memcg
)
2502 * If someone calls draining, avoid adding more kworker runs.
2504 if (!mutex_trylock(&percpu_charge_mutex
))
2506 drain_all_stock(root_memcg
, false);
2507 mutex_unlock(&percpu_charge_mutex
);
2510 /* This is a synchronous drain interface. */
2511 static void drain_all_stock_sync(struct mem_cgroup
*root_memcg
)
2513 /* called when force_empty is called */
2514 mutex_lock(&percpu_charge_mutex
);
2515 drain_all_stock(root_memcg
, true);
2516 mutex_unlock(&percpu_charge_mutex
);
2520 * This function drains percpu counter value from DEAD cpu and
2521 * move it to local cpu. Note that this function can be preempted.
2523 static void mem_cgroup_drain_pcp_counter(struct mem_cgroup
*memcg
, int cpu
)
2527 spin_lock(&memcg
->pcp_counter_lock
);
2528 for (i
= 0; i
< MEM_CGROUP_STAT_NSTATS
; i
++) {
2529 long x
= per_cpu(memcg
->stat
->count
[i
], cpu
);
2531 per_cpu(memcg
->stat
->count
[i
], cpu
) = 0;
2532 memcg
->nocpu_base
.count
[i
] += x
;
2534 for (i
= 0; i
< MEM_CGROUP_EVENTS_NSTATS
; i
++) {
2535 unsigned long x
= per_cpu(memcg
->stat
->events
[i
], cpu
);
2537 per_cpu(memcg
->stat
->events
[i
], cpu
) = 0;
2538 memcg
->nocpu_base
.events
[i
] += x
;
2540 spin_unlock(&memcg
->pcp_counter_lock
);
2543 static int __cpuinit
memcg_cpu_hotplug_callback(struct notifier_block
*nb
,
2544 unsigned long action
,
2547 int cpu
= (unsigned long)hcpu
;
2548 struct memcg_stock_pcp
*stock
;
2549 struct mem_cgroup
*iter
;
2551 if (action
== CPU_ONLINE
)
2554 if (action
!= CPU_DEAD
&& action
!= CPU_DEAD_FROZEN
)
2557 for_each_mem_cgroup(iter
)
2558 mem_cgroup_drain_pcp_counter(iter
, cpu
);
2560 stock
= &per_cpu(memcg_stock
, cpu
);
2566 /* See __mem_cgroup_try_charge() for details */
2568 CHARGE_OK
, /* success */
2569 CHARGE_RETRY
, /* need to retry but retry is not bad */
2570 CHARGE_NOMEM
, /* we can't do more. return -ENOMEM */
2571 CHARGE_WOULDBLOCK
, /* GFP_WAIT wasn't set and no enough res. */
2572 CHARGE_OOM_DIE
, /* the current is killed because of OOM */
2575 static int mem_cgroup_do_charge(struct mem_cgroup
*memcg
, gfp_t gfp_mask
,
2576 unsigned int nr_pages
, unsigned int min_pages
,
2579 unsigned long csize
= nr_pages
* PAGE_SIZE
;
2580 struct mem_cgroup
*mem_over_limit
;
2581 struct res_counter
*fail_res
;
2582 unsigned long flags
= 0;
2585 ret
= res_counter_charge(&memcg
->res
, csize
, &fail_res
);
2588 if (!do_swap_account
)
2590 ret
= res_counter_charge(&memcg
->memsw
, csize
, &fail_res
);
2594 res_counter_uncharge(&memcg
->res
, csize
);
2595 mem_over_limit
= mem_cgroup_from_res_counter(fail_res
, memsw
);
2596 flags
|= MEM_CGROUP_RECLAIM_NOSWAP
;
2598 mem_over_limit
= mem_cgroup_from_res_counter(fail_res
, res
);
2600 * Never reclaim on behalf of optional batching, retry with a
2601 * single page instead.
2603 if (nr_pages
> min_pages
)
2604 return CHARGE_RETRY
;
2606 if (!(gfp_mask
& __GFP_WAIT
))
2607 return CHARGE_WOULDBLOCK
;
2609 if (gfp_mask
& __GFP_NORETRY
)
2610 return CHARGE_NOMEM
;
2612 ret
= mem_cgroup_reclaim(mem_over_limit
, gfp_mask
, flags
);
2613 if (mem_cgroup_margin(mem_over_limit
) >= nr_pages
)
2614 return CHARGE_RETRY
;
2616 * Even though the limit is exceeded at this point, reclaim
2617 * may have been able to free some pages. Retry the charge
2618 * before killing the task.
2620 * Only for regular pages, though: huge pages are rather
2621 * unlikely to succeed so close to the limit, and we fall back
2622 * to regular pages anyway in case of failure.
2624 if (nr_pages
<= (1 << PAGE_ALLOC_COSTLY_ORDER
) && ret
)
2625 return CHARGE_RETRY
;
2628 * At task move, charge accounts can be doubly counted. So, it's
2629 * better to wait until the end of task_move if something is going on.
2631 if (mem_cgroup_wait_acct_move(mem_over_limit
))
2632 return CHARGE_RETRY
;
2634 /* If we don't need to call oom-killer at el, return immediately */
2636 return CHARGE_NOMEM
;
2638 if (!mem_cgroup_handle_oom(mem_over_limit
, gfp_mask
, get_order(csize
)))
2639 return CHARGE_OOM_DIE
;
2641 return CHARGE_RETRY
;
2645 * __mem_cgroup_try_charge() does
2646 * 1. detect memcg to be charged against from passed *mm and *ptr,
2647 * 2. update res_counter
2648 * 3. call memory reclaim if necessary.
2650 * In some special case, if the task is fatal, fatal_signal_pending() or
2651 * has TIF_MEMDIE, this function returns -EINTR while writing root_mem_cgroup
2652 * to *ptr. There are two reasons for this. 1: fatal threads should quit as soon
2653 * as possible without any hazards. 2: all pages should have a valid
2654 * pc->mem_cgroup. If mm is NULL and the caller doesn't pass a valid memcg
2655 * pointer, that is treated as a charge to root_mem_cgroup.
2657 * So __mem_cgroup_try_charge() will return
2658 * 0 ... on success, filling *ptr with a valid memcg pointer.
2659 * -ENOMEM ... charge failure because of resource limits.
2660 * -EINTR ... if thread is fatal. *ptr is filled with root_mem_cgroup.
2662 * Unlike the exported interface, an "oom" parameter is added. if oom==true,
2663 * the oom-killer can be invoked.
2665 static int __mem_cgroup_try_charge(struct mm_struct
*mm
,
2667 unsigned int nr_pages
,
2668 struct mem_cgroup
**ptr
,
2671 unsigned int batch
= max(CHARGE_BATCH
, nr_pages
);
2672 int nr_oom_retries
= MEM_CGROUP_RECLAIM_RETRIES
;
2673 struct mem_cgroup
*memcg
= NULL
;
2677 * Unlike gloval-vm's OOM-kill, we're not in memory shortage
2678 * in system level. So, allow to go ahead dying process in addition to
2681 if (unlikely(test_thread_flag(TIF_MEMDIE
)
2682 || fatal_signal_pending(current
)))
2686 * We always charge the cgroup the mm_struct belongs to.
2687 * The mm_struct's mem_cgroup changes on task migration if the
2688 * thread group leader migrates. It's possible that mm is not
2689 * set, if so charge the root memcg (happens for pagecache usage).
2692 *ptr
= root_mem_cgroup
;
2694 if (*ptr
) { /* css should be a valid one */
2696 if (mem_cgroup_is_root(memcg
))
2698 if (consume_stock(memcg
, nr_pages
))
2700 css_get(&memcg
->css
);
2702 struct task_struct
*p
;
2705 p
= rcu_dereference(mm
->owner
);
2707 * Because we don't have task_lock(), "p" can exit.
2708 * In that case, "memcg" can point to root or p can be NULL with
2709 * race with swapoff. Then, we have small risk of mis-accouning.
2710 * But such kind of mis-account by race always happens because
2711 * we don't have cgroup_mutex(). It's overkill and we allo that
2713 * (*) swapoff at el will charge against mm-struct not against
2714 * task-struct. So, mm->owner can be NULL.
2716 memcg
= mem_cgroup_from_task(p
);
2718 memcg
= root_mem_cgroup
;
2719 if (mem_cgroup_is_root(memcg
)) {
2723 if (consume_stock(memcg
, nr_pages
)) {
2725 * It seems dagerous to access memcg without css_get().
2726 * But considering how consume_stok works, it's not
2727 * necessary. If consume_stock success, some charges
2728 * from this memcg are cached on this cpu. So, we
2729 * don't need to call css_get()/css_tryget() before
2730 * calling consume_stock().
2735 /* after here, we may be blocked. we need to get refcnt */
2736 if (!css_tryget(&memcg
->css
)) {
2746 /* If killed, bypass charge */
2747 if (fatal_signal_pending(current
)) {
2748 css_put(&memcg
->css
);
2753 if (oom
&& !nr_oom_retries
) {
2755 nr_oom_retries
= MEM_CGROUP_RECLAIM_RETRIES
;
2758 ret
= mem_cgroup_do_charge(memcg
, gfp_mask
, batch
, nr_pages
,
2763 case CHARGE_RETRY
: /* not in OOM situation but retry */
2765 css_put(&memcg
->css
);
2768 case CHARGE_WOULDBLOCK
: /* !__GFP_WAIT */
2769 css_put(&memcg
->css
);
2771 case CHARGE_NOMEM
: /* OOM routine works */
2773 css_put(&memcg
->css
);
2776 /* If oom, we never return -ENOMEM */
2779 case CHARGE_OOM_DIE
: /* Killed by OOM Killer */
2780 css_put(&memcg
->css
);
2783 } while (ret
!= CHARGE_OK
);
2785 if (batch
> nr_pages
)
2786 refill_stock(memcg
, batch
- nr_pages
);
2787 css_put(&memcg
->css
);
2795 *ptr
= root_mem_cgroup
;
2800 * Somemtimes we have to undo a charge we got by try_charge().
2801 * This function is for that and do uncharge, put css's refcnt.
2802 * gotten by try_charge().
2804 static void __mem_cgroup_cancel_charge(struct mem_cgroup
*memcg
,
2805 unsigned int nr_pages
)
2807 if (!mem_cgroup_is_root(memcg
)) {
2808 unsigned long bytes
= nr_pages
* PAGE_SIZE
;
2810 res_counter_uncharge(&memcg
->res
, bytes
);
2811 if (do_swap_account
)
2812 res_counter_uncharge(&memcg
->memsw
, bytes
);
2817 * Cancel chrages in this cgroup....doesn't propagate to parent cgroup.
2818 * This is useful when moving usage to parent cgroup.
2820 static void __mem_cgroup_cancel_local_charge(struct mem_cgroup
*memcg
,
2821 unsigned int nr_pages
)
2823 unsigned long bytes
= nr_pages
* PAGE_SIZE
;
2825 if (mem_cgroup_is_root(memcg
))
2828 res_counter_uncharge_until(&memcg
->res
, memcg
->res
.parent
, bytes
);
2829 if (do_swap_account
)
2830 res_counter_uncharge_until(&memcg
->memsw
,
2831 memcg
->memsw
.parent
, bytes
);
2835 * A helper function to get mem_cgroup from ID. must be called under
2836 * rcu_read_lock(). The caller is responsible for calling css_tryget if
2837 * the mem_cgroup is used for charging. (dropping refcnt from swap can be
2838 * called against removed memcg.)
2840 static struct mem_cgroup
*mem_cgroup_lookup(unsigned short id
)
2842 struct cgroup_subsys_state
*css
;
2844 /* ID 0 is unused ID */
2847 css
= css_lookup(&mem_cgroup_subsys
, id
);
2850 return mem_cgroup_from_css(css
);
2853 struct mem_cgroup
*try_get_mem_cgroup_from_page(struct page
*page
)
2855 struct mem_cgroup
*memcg
= NULL
;
2856 struct page_cgroup
*pc
;
2860 VM_BUG_ON(!PageLocked(page
));
2862 pc
= lookup_page_cgroup(page
);
2863 lock_page_cgroup(pc
);
2864 if (PageCgroupUsed(pc
)) {
2865 memcg
= pc
->mem_cgroup
;
2866 if (memcg
&& !css_tryget(&memcg
->css
))
2868 } else if (PageSwapCache(page
)) {
2869 ent
.val
= page_private(page
);
2870 id
= lookup_swap_cgroup_id(ent
);
2872 memcg
= mem_cgroup_lookup(id
);
2873 if (memcg
&& !css_tryget(&memcg
->css
))
2877 unlock_page_cgroup(pc
);
2881 static void __mem_cgroup_commit_charge(struct mem_cgroup
*memcg
,
2883 unsigned int nr_pages
,
2884 enum charge_type ctype
,
2887 struct page_cgroup
*pc
= lookup_page_cgroup(page
);
2888 struct zone
*uninitialized_var(zone
);
2889 struct lruvec
*lruvec
;
2890 bool was_on_lru
= false;
2893 lock_page_cgroup(pc
);
2894 VM_BUG_ON(PageCgroupUsed(pc
));
2896 * we don't need page_cgroup_lock about tail pages, becase they are not
2897 * accessed by any other context at this point.
2901 * In some cases, SwapCache and FUSE(splice_buf->radixtree), the page
2902 * may already be on some other mem_cgroup's LRU. Take care of it.
2905 zone
= page_zone(page
);
2906 spin_lock_irq(&zone
->lru_lock
);
2907 if (PageLRU(page
)) {
2908 lruvec
= mem_cgroup_zone_lruvec(zone
, pc
->mem_cgroup
);
2910 del_page_from_lru_list(page
, lruvec
, page_lru(page
));
2915 pc
->mem_cgroup
= memcg
;
2917 * We access a page_cgroup asynchronously without lock_page_cgroup().
2918 * Especially when a page_cgroup is taken from a page, pc->mem_cgroup
2919 * is accessed after testing USED bit. To make pc->mem_cgroup visible
2920 * before USED bit, we need memory barrier here.
2921 * See mem_cgroup_add_lru_list(), etc.
2924 SetPageCgroupUsed(pc
);
2928 lruvec
= mem_cgroup_zone_lruvec(zone
, pc
->mem_cgroup
);
2929 VM_BUG_ON(PageLRU(page
));
2931 add_page_to_lru_list(page
, lruvec
, page_lru(page
));
2933 spin_unlock_irq(&zone
->lru_lock
);
2936 if (ctype
== MEM_CGROUP_CHARGE_TYPE_ANON
)
2941 mem_cgroup_charge_statistics(memcg
, page
, anon
, nr_pages
);
2942 unlock_page_cgroup(pc
);
2945 * "charge_statistics" updated event counter. Then, check it.
2946 * Insert ancestor (and ancestor's ancestors), to softlimit RB-tree.
2947 * if they exceeds softlimit.
2949 memcg_check_events(memcg
, page
);
2952 static DEFINE_MUTEX(set_limit_mutex
);
2954 #ifdef CONFIG_MEMCG_KMEM
2955 static inline bool memcg_can_account_kmem(struct mem_cgroup
*memcg
)
2957 return !mem_cgroup_disabled() && !mem_cgroup_is_root(memcg
) &&
2958 (memcg
->kmem_account_flags
& KMEM_ACCOUNTED_MASK
);
2962 * This is a bit cumbersome, but it is rarely used and avoids a backpointer
2963 * in the memcg_cache_params struct.
2965 static struct kmem_cache
*memcg_params_to_cache(struct memcg_cache_params
*p
)
2967 struct kmem_cache
*cachep
;
2969 VM_BUG_ON(p
->is_root_cache
);
2970 cachep
= p
->root_cache
;
2971 return cachep
->memcg_params
->memcg_caches
[memcg_cache_id(p
->memcg
)];
2974 #ifdef CONFIG_SLABINFO
2975 static int mem_cgroup_slabinfo_read(struct cgroup
*cont
, struct cftype
*cft
,
2978 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cont
);
2979 struct memcg_cache_params
*params
;
2981 if (!memcg_can_account_kmem(memcg
))
2984 print_slabinfo_header(m
);
2986 mutex_lock(&memcg
->slab_caches_mutex
);
2987 list_for_each_entry(params
, &memcg
->memcg_slab_caches
, list
)
2988 cache_show(memcg_params_to_cache(params
), m
);
2989 mutex_unlock(&memcg
->slab_caches_mutex
);
2995 static int memcg_charge_kmem(struct mem_cgroup
*memcg
, gfp_t gfp
, u64 size
)
2997 struct res_counter
*fail_res
;
2998 struct mem_cgroup
*_memcg
;
3002 ret
= res_counter_charge(&memcg
->kmem
, size
, &fail_res
);
3007 * Conditions under which we can wait for the oom_killer. Those are
3008 * the same conditions tested by the core page allocator
3010 may_oom
= (gfp
& __GFP_FS
) && !(gfp
& __GFP_NORETRY
);
3013 ret
= __mem_cgroup_try_charge(NULL
, gfp
, size
>> PAGE_SHIFT
,
3016 if (ret
== -EINTR
) {
3018 * __mem_cgroup_try_charge() chosed to bypass to root due to
3019 * OOM kill or fatal signal. Since our only options are to
3020 * either fail the allocation or charge it to this cgroup, do
3021 * it as a temporary condition. But we can't fail. From a
3022 * kmem/slab perspective, the cache has already been selected,
3023 * by mem_cgroup_kmem_get_cache(), so it is too late to change
3026 * This condition will only trigger if the task entered
3027 * memcg_charge_kmem in a sane state, but was OOM-killed during
3028 * __mem_cgroup_try_charge() above. Tasks that were already
3029 * dying when the allocation triggers should have been already
3030 * directed to the root cgroup in memcontrol.h
3032 res_counter_charge_nofail(&memcg
->res
, size
, &fail_res
);
3033 if (do_swap_account
)
3034 res_counter_charge_nofail(&memcg
->memsw
, size
,
3038 res_counter_uncharge(&memcg
->kmem
, size
);
3043 static void memcg_uncharge_kmem(struct mem_cgroup
*memcg
, u64 size
)
3045 res_counter_uncharge(&memcg
->res
, size
);
3046 if (do_swap_account
)
3047 res_counter_uncharge(&memcg
->memsw
, size
);
3050 if (res_counter_uncharge(&memcg
->kmem
, size
))
3053 if (memcg_kmem_test_and_clear_dead(memcg
))
3054 mem_cgroup_put(memcg
);
3057 void memcg_cache_list_add(struct mem_cgroup
*memcg
, struct kmem_cache
*cachep
)
3062 mutex_lock(&memcg
->slab_caches_mutex
);
3063 list_add(&cachep
->memcg_params
->list
, &memcg
->memcg_slab_caches
);
3064 mutex_unlock(&memcg
->slab_caches_mutex
);
3068 * helper for acessing a memcg's index. It will be used as an index in the
3069 * child cache array in kmem_cache, and also to derive its name. This function
3070 * will return -1 when this is not a kmem-limited memcg.
3072 int memcg_cache_id(struct mem_cgroup
*memcg
)
3074 return memcg
? memcg
->kmemcg_id
: -1;
3078 * This ends up being protected by the set_limit mutex, during normal
3079 * operation, because that is its main call site.
3081 * But when we create a new cache, we can call this as well if its parent
3082 * is kmem-limited. That will have to hold set_limit_mutex as well.
3084 int memcg_update_cache_sizes(struct mem_cgroup
*memcg
)
3088 num
= ida_simple_get(&kmem_limited_groups
,
3089 0, MEMCG_CACHES_MAX_SIZE
, GFP_KERNEL
);
3093 * After this point, kmem_accounted (that we test atomically in
3094 * the beginning of this conditional), is no longer 0. This
3095 * guarantees only one process will set the following boolean
3096 * to true. We don't need test_and_set because we're protected
3097 * by the set_limit_mutex anyway.
3099 memcg_kmem_set_activated(memcg
);
3101 ret
= memcg_update_all_caches(num
+1);
3103 ida_simple_remove(&kmem_limited_groups
, num
);
3104 memcg_kmem_clear_activated(memcg
);
3108 memcg
->kmemcg_id
= num
;
3109 INIT_LIST_HEAD(&memcg
->memcg_slab_caches
);
3110 mutex_init(&memcg
->slab_caches_mutex
);
3114 static size_t memcg_caches_array_size(int num_groups
)
3117 if (num_groups
<= 0)
3120 size
= 2 * num_groups
;
3121 if (size
< MEMCG_CACHES_MIN_SIZE
)
3122 size
= MEMCG_CACHES_MIN_SIZE
;
3123 else if (size
> MEMCG_CACHES_MAX_SIZE
)
3124 size
= MEMCG_CACHES_MAX_SIZE
;
3130 * We should update the current array size iff all caches updates succeed. This
3131 * can only be done from the slab side. The slab mutex needs to be held when
3134 void memcg_update_array_size(int num
)
3136 if (num
> memcg_limited_groups_array_size
)
3137 memcg_limited_groups_array_size
= memcg_caches_array_size(num
);
3140 static void kmem_cache_destroy_work_func(struct work_struct
*w
);
3142 int memcg_update_cache_size(struct kmem_cache
*s
, int num_groups
)
3144 struct memcg_cache_params
*cur_params
= s
->memcg_params
;
3146 VM_BUG_ON(s
->memcg_params
&& !s
->memcg_params
->is_root_cache
);
3148 if (num_groups
> memcg_limited_groups_array_size
) {
3150 ssize_t size
= memcg_caches_array_size(num_groups
);
3152 size
*= sizeof(void *);
3153 size
+= sizeof(struct memcg_cache_params
);
3155 s
->memcg_params
= kzalloc(size
, GFP_KERNEL
);
3156 if (!s
->memcg_params
) {
3157 s
->memcg_params
= cur_params
;
3161 s
->memcg_params
->is_root_cache
= true;
3164 * There is the chance it will be bigger than
3165 * memcg_limited_groups_array_size, if we failed an allocation
3166 * in a cache, in which case all caches updated before it, will
3167 * have a bigger array.
3169 * But if that is the case, the data after
3170 * memcg_limited_groups_array_size is certainly unused
3172 for (i
= 0; i
< memcg_limited_groups_array_size
; i
++) {
3173 if (!cur_params
->memcg_caches
[i
])
3175 s
->memcg_params
->memcg_caches
[i
] =
3176 cur_params
->memcg_caches
[i
];
3180 * Ideally, we would wait until all caches succeed, and only
3181 * then free the old one. But this is not worth the extra
3182 * pointer per-cache we'd have to have for this.
3184 * It is not a big deal if some caches are left with a size
3185 * bigger than the others. And all updates will reset this
3193 int memcg_register_cache(struct mem_cgroup
*memcg
, struct kmem_cache
*s
,
3194 struct kmem_cache
*root_cache
)
3196 size_t size
= sizeof(struct memcg_cache_params
);
3198 if (!memcg_kmem_enabled())
3202 size
+= memcg_limited_groups_array_size
* sizeof(void *);
3204 s
->memcg_params
= kzalloc(size
, GFP_KERNEL
);
3205 if (!s
->memcg_params
)
3208 INIT_WORK(&s
->memcg_params
->destroy
,
3209 kmem_cache_destroy_work_func
);
3211 s
->memcg_params
->memcg
= memcg
;
3212 s
->memcg_params
->root_cache
= root_cache
;
3214 s
->memcg_params
->is_root_cache
= true;
3219 void memcg_release_cache(struct kmem_cache
*s
)
3221 struct kmem_cache
*root
;
3222 struct mem_cgroup
*memcg
;
3226 * This happens, for instance, when a root cache goes away before we
3229 if (!s
->memcg_params
)
3232 if (s
->memcg_params
->is_root_cache
)
3235 memcg
= s
->memcg_params
->memcg
;
3236 id
= memcg_cache_id(memcg
);
3238 root
= s
->memcg_params
->root_cache
;
3239 root
->memcg_params
->memcg_caches
[id
] = NULL
;
3241 mutex_lock(&memcg
->slab_caches_mutex
);
3242 list_del(&s
->memcg_params
->list
);
3243 mutex_unlock(&memcg
->slab_caches_mutex
);
3245 mem_cgroup_put(memcg
);
3247 kfree(s
->memcg_params
);
3251 * During the creation a new cache, we need to disable our accounting mechanism
3252 * altogether. This is true even if we are not creating, but rather just
3253 * enqueing new caches to be created.
3255 * This is because that process will trigger allocations; some visible, like
3256 * explicit kmallocs to auxiliary data structures, name strings and internal
3257 * cache structures; some well concealed, like INIT_WORK() that can allocate
3258 * objects during debug.
3260 * If any allocation happens during memcg_kmem_get_cache, we will recurse back
3261 * to it. This may not be a bounded recursion: since the first cache creation
3262 * failed to complete (waiting on the allocation), we'll just try to create the
3263 * cache again, failing at the same point.
3265 * memcg_kmem_get_cache is prepared to abort after seeing a positive count of
3266 * memcg_kmem_skip_account. So we enclose anything that might allocate memory
3267 * inside the following two functions.
3269 static inline void memcg_stop_kmem_account(void)
3271 VM_BUG_ON(!current
->mm
);
3272 current
->memcg_kmem_skip_account
++;
3275 static inline void memcg_resume_kmem_account(void)
3277 VM_BUG_ON(!current
->mm
);
3278 current
->memcg_kmem_skip_account
--;
3281 static void kmem_cache_destroy_work_func(struct work_struct
*w
)
3283 struct kmem_cache
*cachep
;
3284 struct memcg_cache_params
*p
;
3286 p
= container_of(w
, struct memcg_cache_params
, destroy
);
3288 cachep
= memcg_params_to_cache(p
);
3291 * If we get down to 0 after shrink, we could delete right away.
3292 * However, memcg_release_pages() already puts us back in the workqueue
3293 * in that case. If we proceed deleting, we'll get a dangling
3294 * reference, and removing the object from the workqueue in that case
3295 * is unnecessary complication. We are not a fast path.
3297 * Note that this case is fundamentally different from racing with
3298 * shrink_slab(): if memcg_cgroup_destroy_cache() is called in
3299 * kmem_cache_shrink, not only we would be reinserting a dead cache
3300 * into the queue, but doing so from inside the worker racing to
3303 * So if we aren't down to zero, we'll just schedule a worker and try
3306 if (atomic_read(&cachep
->memcg_params
->nr_pages
) != 0) {
3307 kmem_cache_shrink(cachep
);
3308 if (atomic_read(&cachep
->memcg_params
->nr_pages
) == 0)
3311 kmem_cache_destroy(cachep
);
3314 void mem_cgroup_destroy_cache(struct kmem_cache
*cachep
)
3316 if (!cachep
->memcg_params
->dead
)
3320 * There are many ways in which we can get here.
3322 * We can get to a memory-pressure situation while the delayed work is
3323 * still pending to run. The vmscan shrinkers can then release all
3324 * cache memory and get us to destruction. If this is the case, we'll
3325 * be executed twice, which is a bug (the second time will execute over
3326 * bogus data). In this case, cancelling the work should be fine.
3328 * But we can also get here from the worker itself, if
3329 * kmem_cache_shrink is enough to shake all the remaining objects and
3330 * get the page count to 0. In this case, we'll deadlock if we try to
3331 * cancel the work (the worker runs with an internal lock held, which
3332 * is the same lock we would hold for cancel_work_sync().)
3334 * Since we can't possibly know who got us here, just refrain from
3335 * running if there is already work pending
3337 if (work_pending(&cachep
->memcg_params
->destroy
))
3340 * We have to defer the actual destroying to a workqueue, because
3341 * we might currently be in a context that cannot sleep.
3343 schedule_work(&cachep
->memcg_params
->destroy
);
3347 * This lock protects updaters, not readers. We want readers to be as fast as
3348 * they can, and they will either see NULL or a valid cache value. Our model
3349 * allow them to see NULL, in which case the root memcg will be selected.
3351 * We need this lock because multiple allocations to the same cache from a non
3352 * will span more than one worker. Only one of them can create the cache.
3354 static DEFINE_MUTEX(memcg_cache_mutex
);
3357 * Called with memcg_cache_mutex held
3359 static struct kmem_cache
*kmem_cache_dup(struct mem_cgroup
*memcg
,
3360 struct kmem_cache
*s
)
3362 struct kmem_cache
*new;
3363 static char *tmp_name
= NULL
;
3365 lockdep_assert_held(&memcg_cache_mutex
);
3368 * kmem_cache_create_memcg duplicates the given name and
3369 * cgroup_name for this name requires RCU context.
3370 * This static temporary buffer is used to prevent from
3371 * pointless shortliving allocation.
3374 tmp_name
= kmalloc(PATH_MAX
, GFP_KERNEL
);
3380 snprintf(tmp_name
, PATH_MAX
, "%s(%d:%s)", s
->name
,
3381 memcg_cache_id(memcg
), cgroup_name(memcg
->css
.cgroup
));
3384 new = kmem_cache_create_memcg(memcg
, tmp_name
, s
->object_size
, s
->align
,
3385 (s
->flags
& ~SLAB_PANIC
), s
->ctor
, s
);
3388 new->allocflags
|= __GFP_KMEMCG
;
3393 static struct kmem_cache
*memcg_create_kmem_cache(struct mem_cgroup
*memcg
,
3394 struct kmem_cache
*cachep
)
3396 struct kmem_cache
*new_cachep
;
3399 BUG_ON(!memcg_can_account_kmem(memcg
));
3401 idx
= memcg_cache_id(memcg
);
3403 mutex_lock(&memcg_cache_mutex
);
3404 new_cachep
= cachep
->memcg_params
->memcg_caches
[idx
];
3408 new_cachep
= kmem_cache_dup(memcg
, cachep
);
3409 if (new_cachep
== NULL
) {
3410 new_cachep
= cachep
;
3414 mem_cgroup_get(memcg
);
3415 atomic_set(&new_cachep
->memcg_params
->nr_pages
, 0);
3417 cachep
->memcg_params
->memcg_caches
[idx
] = new_cachep
;
3419 * the readers won't lock, make sure everybody sees the updated value,
3420 * so they won't put stuff in the queue again for no reason
3424 mutex_unlock(&memcg_cache_mutex
);
3428 void kmem_cache_destroy_memcg_children(struct kmem_cache
*s
)
3430 struct kmem_cache
*c
;
3433 if (!s
->memcg_params
)
3435 if (!s
->memcg_params
->is_root_cache
)
3439 * If the cache is being destroyed, we trust that there is no one else
3440 * requesting objects from it. Even if there are, the sanity checks in
3441 * kmem_cache_destroy should caught this ill-case.
3443 * Still, we don't want anyone else freeing memcg_caches under our
3444 * noses, which can happen if a new memcg comes to life. As usual,
3445 * we'll take the set_limit_mutex to protect ourselves against this.
3447 mutex_lock(&set_limit_mutex
);
3448 for (i
= 0; i
< memcg_limited_groups_array_size
; i
++) {
3449 c
= s
->memcg_params
->memcg_caches
[i
];
3454 * We will now manually delete the caches, so to avoid races
3455 * we need to cancel all pending destruction workers and
3456 * proceed with destruction ourselves.
3458 * kmem_cache_destroy() will call kmem_cache_shrink internally,
3459 * and that could spawn the workers again: it is likely that
3460 * the cache still have active pages until this very moment.
3461 * This would lead us back to mem_cgroup_destroy_cache.
3463 * But that will not execute at all if the "dead" flag is not
3464 * set, so flip it down to guarantee we are in control.
3466 c
->memcg_params
->dead
= false;
3467 cancel_work_sync(&c
->memcg_params
->destroy
);
3468 kmem_cache_destroy(c
);
3470 mutex_unlock(&set_limit_mutex
);
3473 struct create_work
{
3474 struct mem_cgroup
*memcg
;
3475 struct kmem_cache
*cachep
;
3476 struct work_struct work
;
3479 static void mem_cgroup_destroy_all_caches(struct mem_cgroup
*memcg
)
3481 struct kmem_cache
*cachep
;
3482 struct memcg_cache_params
*params
;
3484 if (!memcg_kmem_is_active(memcg
))
3487 mutex_lock(&memcg
->slab_caches_mutex
);
3488 list_for_each_entry(params
, &memcg
->memcg_slab_caches
, list
) {
3489 cachep
= memcg_params_to_cache(params
);
3490 cachep
->memcg_params
->dead
= true;
3491 schedule_work(&cachep
->memcg_params
->destroy
);
3493 mutex_unlock(&memcg
->slab_caches_mutex
);
3496 static void memcg_create_cache_work_func(struct work_struct
*w
)
3498 struct create_work
*cw
;
3500 cw
= container_of(w
, struct create_work
, work
);
3501 memcg_create_kmem_cache(cw
->memcg
, cw
->cachep
);
3502 /* Drop the reference gotten when we enqueued. */
3503 css_put(&cw
->memcg
->css
);
3508 * Enqueue the creation of a per-memcg kmem_cache.
3510 static void __memcg_create_cache_enqueue(struct mem_cgroup
*memcg
,
3511 struct kmem_cache
*cachep
)
3513 struct create_work
*cw
;
3515 cw
= kmalloc(sizeof(struct create_work
), GFP_NOWAIT
);
3517 css_put(&memcg
->css
);
3522 cw
->cachep
= cachep
;
3524 INIT_WORK(&cw
->work
, memcg_create_cache_work_func
);
3525 schedule_work(&cw
->work
);
3528 static void memcg_create_cache_enqueue(struct mem_cgroup
*memcg
,
3529 struct kmem_cache
*cachep
)
3532 * We need to stop accounting when we kmalloc, because if the
3533 * corresponding kmalloc cache is not yet created, the first allocation
3534 * in __memcg_create_cache_enqueue will recurse.
3536 * However, it is better to enclose the whole function. Depending on
3537 * the debugging options enabled, INIT_WORK(), for instance, can
3538 * trigger an allocation. This too, will make us recurse. Because at
3539 * this point we can't allow ourselves back into memcg_kmem_get_cache,
3540 * the safest choice is to do it like this, wrapping the whole function.
3542 memcg_stop_kmem_account();
3543 __memcg_create_cache_enqueue(memcg
, cachep
);
3544 memcg_resume_kmem_account();
3547 * Return the kmem_cache we're supposed to use for a slab allocation.
3548 * We try to use the current memcg's version of the cache.
3550 * If the cache does not exist yet, if we are the first user of it,
3551 * we either create it immediately, if possible, or create it asynchronously
3553 * In the latter case, we will let the current allocation go through with
3554 * the original cache.
3556 * Can't be called in interrupt context or from kernel threads.
3557 * This function needs to be called with rcu_read_lock() held.
3559 struct kmem_cache
*__memcg_kmem_get_cache(struct kmem_cache
*cachep
,
3562 struct mem_cgroup
*memcg
;
3565 VM_BUG_ON(!cachep
->memcg_params
);
3566 VM_BUG_ON(!cachep
->memcg_params
->is_root_cache
);
3568 if (!current
->mm
|| current
->memcg_kmem_skip_account
)
3572 memcg
= mem_cgroup_from_task(rcu_dereference(current
->mm
->owner
));
3574 if (!memcg_can_account_kmem(memcg
))
3577 idx
= memcg_cache_id(memcg
);
3580 * barrier to mare sure we're always seeing the up to date value. The
3581 * code updating memcg_caches will issue a write barrier to match this.
3583 read_barrier_depends();
3584 if (likely(cachep
->memcg_params
->memcg_caches
[idx
])) {
3585 cachep
= cachep
->memcg_params
->memcg_caches
[idx
];
3589 /* The corresponding put will be done in the workqueue. */
3590 if (!css_tryget(&memcg
->css
))
3595 * If we are in a safe context (can wait, and not in interrupt
3596 * context), we could be be predictable and return right away.
3597 * This would guarantee that the allocation being performed
3598 * already belongs in the new cache.
3600 * However, there are some clashes that can arrive from locking.
3601 * For instance, because we acquire the slab_mutex while doing
3602 * kmem_cache_dup, this means no further allocation could happen
3603 * with the slab_mutex held.
3605 * Also, because cache creation issue get_online_cpus(), this
3606 * creates a lock chain: memcg_slab_mutex -> cpu_hotplug_mutex,
3607 * that ends up reversed during cpu hotplug. (cpuset allocates
3608 * a bunch of GFP_KERNEL memory during cpuup). Due to all that,
3609 * better to defer everything.
3611 memcg_create_cache_enqueue(memcg
, cachep
);
3617 EXPORT_SYMBOL(__memcg_kmem_get_cache
);
3620 * We need to verify if the allocation against current->mm->owner's memcg is
3621 * possible for the given order. But the page is not allocated yet, so we'll
3622 * need a further commit step to do the final arrangements.
3624 * It is possible for the task to switch cgroups in this mean time, so at
3625 * commit time, we can't rely on task conversion any longer. We'll then use
3626 * the handle argument to return to the caller which cgroup we should commit
3627 * against. We could also return the memcg directly and avoid the pointer
3628 * passing, but a boolean return value gives better semantics considering
3629 * the compiled-out case as well.
3631 * Returning true means the allocation is possible.
3634 __memcg_kmem_newpage_charge(gfp_t gfp
, struct mem_cgroup
**_memcg
, int order
)
3636 struct mem_cgroup
*memcg
;
3640 memcg
= try_get_mem_cgroup_from_mm(current
->mm
);
3643 * very rare case described in mem_cgroup_from_task. Unfortunately there
3644 * isn't much we can do without complicating this too much, and it would
3645 * be gfp-dependent anyway. Just let it go
3647 if (unlikely(!memcg
))
3650 if (!memcg_can_account_kmem(memcg
)) {
3651 css_put(&memcg
->css
);
3655 ret
= memcg_charge_kmem(memcg
, gfp
, PAGE_SIZE
<< order
);
3659 css_put(&memcg
->css
);
3663 void __memcg_kmem_commit_charge(struct page
*page
, struct mem_cgroup
*memcg
,
3666 struct page_cgroup
*pc
;
3668 VM_BUG_ON(mem_cgroup_is_root(memcg
));
3670 /* The page allocation failed. Revert */
3672 memcg_uncharge_kmem(memcg
, PAGE_SIZE
<< order
);
3676 pc
= lookup_page_cgroup(page
);
3677 lock_page_cgroup(pc
);
3678 pc
->mem_cgroup
= memcg
;
3679 SetPageCgroupUsed(pc
);
3680 unlock_page_cgroup(pc
);
3683 void __memcg_kmem_uncharge_pages(struct page
*page
, int order
)
3685 struct mem_cgroup
*memcg
= NULL
;
3686 struct page_cgroup
*pc
;
3689 pc
= lookup_page_cgroup(page
);
3691 * Fast unlocked return. Theoretically might have changed, have to
3692 * check again after locking.
3694 if (!PageCgroupUsed(pc
))
3697 lock_page_cgroup(pc
);
3698 if (PageCgroupUsed(pc
)) {
3699 memcg
= pc
->mem_cgroup
;
3700 ClearPageCgroupUsed(pc
);
3702 unlock_page_cgroup(pc
);
3705 * We trust that only if there is a memcg associated with the page, it
3706 * is a valid allocation
3711 VM_BUG_ON(mem_cgroup_is_root(memcg
));
3712 memcg_uncharge_kmem(memcg
, PAGE_SIZE
<< order
);
3715 static inline void mem_cgroup_destroy_all_caches(struct mem_cgroup
*memcg
)
3718 #endif /* CONFIG_MEMCG_KMEM */
3720 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
3722 #define PCGF_NOCOPY_AT_SPLIT (1 << PCG_LOCK | 1 << PCG_MIGRATION)
3724 * Because tail pages are not marked as "used", set it. We're under
3725 * zone->lru_lock, 'splitting on pmd' and compound_lock.
3726 * charge/uncharge will be never happen and move_account() is done under
3727 * compound_lock(), so we don't have to take care of races.
3729 void mem_cgroup_split_huge_fixup(struct page
*head
)
3731 struct page_cgroup
*head_pc
= lookup_page_cgroup(head
);
3732 struct page_cgroup
*pc
;
3733 struct mem_cgroup
*memcg
;
3736 if (mem_cgroup_disabled())
3739 memcg
= head_pc
->mem_cgroup
;
3740 for (i
= 1; i
< HPAGE_PMD_NR
; i
++) {
3742 pc
->mem_cgroup
= memcg
;
3743 smp_wmb();/* see __commit_charge() */
3744 pc
->flags
= head_pc
->flags
& ~PCGF_NOCOPY_AT_SPLIT
;
3746 __this_cpu_sub(memcg
->stat
->count
[MEM_CGROUP_STAT_RSS_HUGE
],
3749 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
3752 * mem_cgroup_move_account - move account of the page
3754 * @nr_pages: number of regular pages (>1 for huge pages)
3755 * @pc: page_cgroup of the page.
3756 * @from: mem_cgroup which the page is moved from.
3757 * @to: mem_cgroup which the page is moved to. @from != @to.
3759 * The caller must confirm following.
3760 * - page is not on LRU (isolate_page() is useful.)
3761 * - compound_lock is held when nr_pages > 1
3763 * This function doesn't do "charge" to new cgroup and doesn't do "uncharge"
3766 static int mem_cgroup_move_account(struct page
*page
,
3767 unsigned int nr_pages
,
3768 struct page_cgroup
*pc
,
3769 struct mem_cgroup
*from
,
3770 struct mem_cgroup
*to
)
3772 unsigned long flags
;
3774 bool anon
= PageAnon(page
);
3776 VM_BUG_ON(from
== to
);
3777 VM_BUG_ON(PageLRU(page
));
3779 * The page is isolated from LRU. So, collapse function
3780 * will not handle this page. But page splitting can happen.
3781 * Do this check under compound_page_lock(). The caller should
3785 if (nr_pages
> 1 && !PageTransHuge(page
))
3788 lock_page_cgroup(pc
);
3791 if (!PageCgroupUsed(pc
) || pc
->mem_cgroup
!= from
)
3794 move_lock_mem_cgroup(from
, &flags
);
3796 if (!anon
&& page_mapped(page
)) {
3797 /* Update mapped_file data for mem_cgroup */
3799 __this_cpu_dec(from
->stat
->count
[MEM_CGROUP_STAT_FILE_MAPPED
]);
3800 __this_cpu_inc(to
->stat
->count
[MEM_CGROUP_STAT_FILE_MAPPED
]);
3803 mem_cgroup_charge_statistics(from
, page
, anon
, -nr_pages
);
3805 /* caller should have done css_get */
3806 pc
->mem_cgroup
= to
;
3807 mem_cgroup_charge_statistics(to
, page
, anon
, nr_pages
);
3808 move_unlock_mem_cgroup(from
, &flags
);
3811 unlock_page_cgroup(pc
);
3815 memcg_check_events(to
, page
);
3816 memcg_check_events(from
, page
);
3822 * mem_cgroup_move_parent - moves page to the parent group
3823 * @page: the page to move
3824 * @pc: page_cgroup of the page
3825 * @child: page's cgroup
3827 * move charges to its parent or the root cgroup if the group has no
3828 * parent (aka use_hierarchy==0).
3829 * Although this might fail (get_page_unless_zero, isolate_lru_page or
3830 * mem_cgroup_move_account fails) the failure is always temporary and
3831 * it signals a race with a page removal/uncharge or migration. In the
3832 * first case the page is on the way out and it will vanish from the LRU
3833 * on the next attempt and the call should be retried later.
3834 * Isolation from the LRU fails only if page has been isolated from
3835 * the LRU since we looked at it and that usually means either global
3836 * reclaim or migration going on. The page will either get back to the
3838 * Finaly mem_cgroup_move_account fails only if the page got uncharged
3839 * (!PageCgroupUsed) or moved to a different group. The page will
3840 * disappear in the next attempt.
3842 static int mem_cgroup_move_parent(struct page
*page
,
3843 struct page_cgroup
*pc
,
3844 struct mem_cgroup
*child
)
3846 struct mem_cgroup
*parent
;
3847 unsigned int nr_pages
;
3848 unsigned long uninitialized_var(flags
);
3851 VM_BUG_ON(mem_cgroup_is_root(child
));
3854 if (!get_page_unless_zero(page
))
3856 if (isolate_lru_page(page
))
3859 nr_pages
= hpage_nr_pages(page
);
3861 parent
= parent_mem_cgroup(child
);
3863 * If no parent, move charges to root cgroup.
3866 parent
= root_mem_cgroup
;
3869 VM_BUG_ON(!PageTransHuge(page
));
3870 flags
= compound_lock_irqsave(page
);
3873 ret
= mem_cgroup_move_account(page
, nr_pages
,
3876 __mem_cgroup_cancel_local_charge(child
, nr_pages
);
3879 compound_unlock_irqrestore(page
, flags
);
3880 putback_lru_page(page
);
3888 * Charge the memory controller for page usage.
3890 * 0 if the charge was successful
3891 * < 0 if the cgroup is over its limit
3893 static int mem_cgroup_charge_common(struct page
*page
, struct mm_struct
*mm
,
3894 gfp_t gfp_mask
, enum charge_type ctype
)
3896 struct mem_cgroup
*memcg
= NULL
;
3897 unsigned int nr_pages
= 1;
3901 if (PageTransHuge(page
)) {
3902 nr_pages
<<= compound_order(page
);
3903 VM_BUG_ON(!PageTransHuge(page
));
3905 * Never OOM-kill a process for a huge page. The
3906 * fault handler will fall back to regular pages.
3911 ret
= __mem_cgroup_try_charge(mm
, gfp_mask
, nr_pages
, &memcg
, oom
);
3914 __mem_cgroup_commit_charge(memcg
, page
, nr_pages
, ctype
, false);
3918 int mem_cgroup_newpage_charge(struct page
*page
,
3919 struct mm_struct
*mm
, gfp_t gfp_mask
)
3921 if (mem_cgroup_disabled())
3923 VM_BUG_ON(page_mapped(page
));
3924 VM_BUG_ON(page
->mapping
&& !PageAnon(page
));
3926 return mem_cgroup_charge_common(page
, mm
, gfp_mask
,
3927 MEM_CGROUP_CHARGE_TYPE_ANON
);
3931 * While swap-in, try_charge -> commit or cancel, the page is locked.
3932 * And when try_charge() successfully returns, one refcnt to memcg without
3933 * struct page_cgroup is acquired. This refcnt will be consumed by
3934 * "commit()" or removed by "cancel()"
3936 static int __mem_cgroup_try_charge_swapin(struct mm_struct
*mm
,
3939 struct mem_cgroup
**memcgp
)
3941 struct mem_cgroup
*memcg
;
3942 struct page_cgroup
*pc
;
3945 pc
= lookup_page_cgroup(page
);
3947 * Every swap fault against a single page tries to charge the
3948 * page, bail as early as possible. shmem_unuse() encounters
3949 * already charged pages, too. The USED bit is protected by
3950 * the page lock, which serializes swap cache removal, which
3951 * in turn serializes uncharging.
3953 if (PageCgroupUsed(pc
))
3955 if (!do_swap_account
)
3957 memcg
= try_get_mem_cgroup_from_page(page
);
3961 ret
= __mem_cgroup_try_charge(NULL
, mask
, 1, memcgp
, true);
3962 css_put(&memcg
->css
);
3967 ret
= __mem_cgroup_try_charge(mm
, mask
, 1, memcgp
, true);
3973 int mem_cgroup_try_charge_swapin(struct mm_struct
*mm
, struct page
*page
,
3974 gfp_t gfp_mask
, struct mem_cgroup
**memcgp
)
3977 if (mem_cgroup_disabled())
3980 * A racing thread's fault, or swapoff, may have already
3981 * updated the pte, and even removed page from swap cache: in
3982 * those cases unuse_pte()'s pte_same() test will fail; but
3983 * there's also a KSM case which does need to charge the page.
3985 if (!PageSwapCache(page
)) {
3988 ret
= __mem_cgroup_try_charge(mm
, gfp_mask
, 1, memcgp
, true);
3993 return __mem_cgroup_try_charge_swapin(mm
, page
, gfp_mask
, memcgp
);
3996 void mem_cgroup_cancel_charge_swapin(struct mem_cgroup
*memcg
)
3998 if (mem_cgroup_disabled())
4002 __mem_cgroup_cancel_charge(memcg
, 1);
4006 __mem_cgroup_commit_charge_swapin(struct page
*page
, struct mem_cgroup
*memcg
,
4007 enum charge_type ctype
)
4009 if (mem_cgroup_disabled())
4014 __mem_cgroup_commit_charge(memcg
, page
, 1, ctype
, true);
4016 * Now swap is on-memory. This means this page may be
4017 * counted both as mem and swap....double count.
4018 * Fix it by uncharging from memsw. Basically, this SwapCache is stable
4019 * under lock_page(). But in do_swap_page()::memory.c, reuse_swap_page()
4020 * may call delete_from_swap_cache() before reach here.
4022 if (do_swap_account
&& PageSwapCache(page
)) {
4023 swp_entry_t ent
= {.val
= page_private(page
)};
4024 mem_cgroup_uncharge_swap(ent
);
4028 void mem_cgroup_commit_charge_swapin(struct page
*page
,
4029 struct mem_cgroup
*memcg
)
4031 __mem_cgroup_commit_charge_swapin(page
, memcg
,
4032 MEM_CGROUP_CHARGE_TYPE_ANON
);
4035 int mem_cgroup_cache_charge(struct page
*page
, struct mm_struct
*mm
,
4038 struct mem_cgroup
*memcg
= NULL
;
4039 enum charge_type type
= MEM_CGROUP_CHARGE_TYPE_CACHE
;
4042 if (mem_cgroup_disabled())
4044 if (PageCompound(page
))
4047 if (!PageSwapCache(page
))
4048 ret
= mem_cgroup_charge_common(page
, mm
, gfp_mask
, type
);
4049 else { /* page is swapcache/shmem */
4050 ret
= __mem_cgroup_try_charge_swapin(mm
, page
,
4053 __mem_cgroup_commit_charge_swapin(page
, memcg
, type
);
4058 static void mem_cgroup_do_uncharge(struct mem_cgroup
*memcg
,
4059 unsigned int nr_pages
,
4060 const enum charge_type ctype
)
4062 struct memcg_batch_info
*batch
= NULL
;
4063 bool uncharge_memsw
= true;
4065 /* If swapout, usage of swap doesn't decrease */
4066 if (!do_swap_account
|| ctype
== MEM_CGROUP_CHARGE_TYPE_SWAPOUT
)
4067 uncharge_memsw
= false;
4069 batch
= ¤t
->memcg_batch
;
4071 * In usual, we do css_get() when we remember memcg pointer.
4072 * But in this case, we keep res->usage until end of a series of
4073 * uncharges. Then, it's ok to ignore memcg's refcnt.
4076 batch
->memcg
= memcg
;
4078 * do_batch > 0 when unmapping pages or inode invalidate/truncate.
4079 * In those cases, all pages freed continuously can be expected to be in
4080 * the same cgroup and we have chance to coalesce uncharges.
4081 * But we do uncharge one by one if this is killed by OOM(TIF_MEMDIE)
4082 * because we want to do uncharge as soon as possible.
4085 if (!batch
->do_batch
|| test_thread_flag(TIF_MEMDIE
))
4086 goto direct_uncharge
;
4089 goto direct_uncharge
;
4092 * In typical case, batch->memcg == mem. This means we can
4093 * merge a series of uncharges to an uncharge of res_counter.
4094 * If not, we uncharge res_counter ony by one.
4096 if (batch
->memcg
!= memcg
)
4097 goto direct_uncharge
;
4098 /* remember freed charge and uncharge it later */
4101 batch
->memsw_nr_pages
++;
4104 res_counter_uncharge(&memcg
->res
, nr_pages
* PAGE_SIZE
);
4106 res_counter_uncharge(&memcg
->memsw
, nr_pages
* PAGE_SIZE
);
4107 if (unlikely(batch
->memcg
!= memcg
))
4108 memcg_oom_recover(memcg
);
4112 * uncharge if !page_mapped(page)
4114 static struct mem_cgroup
*
4115 __mem_cgroup_uncharge_common(struct page
*page
, enum charge_type ctype
,
4118 struct mem_cgroup
*memcg
= NULL
;
4119 unsigned int nr_pages
= 1;
4120 struct page_cgroup
*pc
;
4123 if (mem_cgroup_disabled())
4126 if (PageTransHuge(page
)) {
4127 nr_pages
<<= compound_order(page
);
4128 VM_BUG_ON(!PageTransHuge(page
));
4131 * Check if our page_cgroup is valid
4133 pc
= lookup_page_cgroup(page
);
4134 if (unlikely(!PageCgroupUsed(pc
)))
4137 lock_page_cgroup(pc
);
4139 memcg
= pc
->mem_cgroup
;
4141 if (!PageCgroupUsed(pc
))
4144 anon
= PageAnon(page
);
4147 case MEM_CGROUP_CHARGE_TYPE_ANON
:
4149 * Generally PageAnon tells if it's the anon statistics to be
4150 * updated; but sometimes e.g. mem_cgroup_uncharge_page() is
4151 * used before page reached the stage of being marked PageAnon.
4155 case MEM_CGROUP_CHARGE_TYPE_DROP
:
4156 /* See mem_cgroup_prepare_migration() */
4157 if (page_mapped(page
))
4160 * Pages under migration may not be uncharged. But
4161 * end_migration() /must/ be the one uncharging the
4162 * unused post-migration page and so it has to call
4163 * here with the migration bit still set. See the
4164 * res_counter handling below.
4166 if (!end_migration
&& PageCgroupMigration(pc
))
4169 case MEM_CGROUP_CHARGE_TYPE_SWAPOUT
:
4170 if (!PageAnon(page
)) { /* Shared memory */
4171 if (page
->mapping
&& !page_is_file_cache(page
))
4173 } else if (page_mapped(page
)) /* Anon */
4180 mem_cgroup_charge_statistics(memcg
, page
, anon
, -nr_pages
);
4182 ClearPageCgroupUsed(pc
);
4184 * pc->mem_cgroup is not cleared here. It will be accessed when it's
4185 * freed from LRU. This is safe because uncharged page is expected not
4186 * to be reused (freed soon). Exception is SwapCache, it's handled by
4187 * special functions.
4190 unlock_page_cgroup(pc
);
4192 * even after unlock, we have memcg->res.usage here and this memcg
4193 * will never be freed.
4195 memcg_check_events(memcg
, page
);
4196 if (do_swap_account
&& ctype
== MEM_CGROUP_CHARGE_TYPE_SWAPOUT
) {
4197 mem_cgroup_swap_statistics(memcg
, true);
4198 mem_cgroup_get(memcg
);
4201 * Migration does not charge the res_counter for the
4202 * replacement page, so leave it alone when phasing out the
4203 * page that is unused after the migration.
4205 if (!end_migration
&& !mem_cgroup_is_root(memcg
))
4206 mem_cgroup_do_uncharge(memcg
, nr_pages
, ctype
);
4211 unlock_page_cgroup(pc
);
4215 void mem_cgroup_uncharge_page(struct page
*page
)
4218 if (page_mapped(page
))
4220 VM_BUG_ON(page
->mapping
&& !PageAnon(page
));
4222 * If the page is in swap cache, uncharge should be deferred
4223 * to the swap path, which also properly accounts swap usage
4224 * and handles memcg lifetime.
4226 * Note that this check is not stable and reclaim may add the
4227 * page to swap cache at any time after this. However, if the
4228 * page is not in swap cache by the time page->mapcount hits
4229 * 0, there won't be any page table references to the swap
4230 * slot, and reclaim will free it and not actually write the
4233 if (PageSwapCache(page
))
4235 __mem_cgroup_uncharge_common(page
, MEM_CGROUP_CHARGE_TYPE_ANON
, false);
4238 void mem_cgroup_uncharge_cache_page(struct page
*page
)
4240 VM_BUG_ON(page_mapped(page
));
4241 VM_BUG_ON(page
->mapping
);
4242 __mem_cgroup_uncharge_common(page
, MEM_CGROUP_CHARGE_TYPE_CACHE
, false);
4246 * Batch_start/batch_end is called in unmap_page_range/invlidate/trucate.
4247 * In that cases, pages are freed continuously and we can expect pages
4248 * are in the same memcg. All these calls itself limits the number of
4249 * pages freed at once, then uncharge_start/end() is called properly.
4250 * This may be called prural(2) times in a context,
4253 void mem_cgroup_uncharge_start(void)
4255 current
->memcg_batch
.do_batch
++;
4256 /* We can do nest. */
4257 if (current
->memcg_batch
.do_batch
== 1) {
4258 current
->memcg_batch
.memcg
= NULL
;
4259 current
->memcg_batch
.nr_pages
= 0;
4260 current
->memcg_batch
.memsw_nr_pages
= 0;
4264 void mem_cgroup_uncharge_end(void)
4266 struct memcg_batch_info
*batch
= ¤t
->memcg_batch
;
4268 if (!batch
->do_batch
)
4272 if (batch
->do_batch
) /* If stacked, do nothing. */
4278 * This "batch->memcg" is valid without any css_get/put etc...
4279 * bacause we hide charges behind us.
4281 if (batch
->nr_pages
)
4282 res_counter_uncharge(&batch
->memcg
->res
,
4283 batch
->nr_pages
* PAGE_SIZE
);
4284 if (batch
->memsw_nr_pages
)
4285 res_counter_uncharge(&batch
->memcg
->memsw
,
4286 batch
->memsw_nr_pages
* PAGE_SIZE
);
4287 memcg_oom_recover(batch
->memcg
);
4288 /* forget this pointer (for sanity check) */
4289 batch
->memcg
= NULL
;
4294 * called after __delete_from_swap_cache() and drop "page" account.
4295 * memcg information is recorded to swap_cgroup of "ent"
4298 mem_cgroup_uncharge_swapcache(struct page
*page
, swp_entry_t ent
, bool swapout
)
4300 struct mem_cgroup
*memcg
;
4301 int ctype
= MEM_CGROUP_CHARGE_TYPE_SWAPOUT
;
4303 if (!swapout
) /* this was a swap cache but the swap is unused ! */
4304 ctype
= MEM_CGROUP_CHARGE_TYPE_DROP
;
4306 memcg
= __mem_cgroup_uncharge_common(page
, ctype
, false);
4309 * record memcg information, if swapout && memcg != NULL,
4310 * mem_cgroup_get() was called in uncharge().
4312 if (do_swap_account
&& swapout
&& memcg
)
4313 swap_cgroup_record(ent
, css_id(&memcg
->css
));
4317 #ifdef CONFIG_MEMCG_SWAP
4319 * called from swap_entry_free(). remove record in swap_cgroup and
4320 * uncharge "memsw" account.
4322 void mem_cgroup_uncharge_swap(swp_entry_t ent
)
4324 struct mem_cgroup
*memcg
;
4327 if (!do_swap_account
)
4330 id
= swap_cgroup_record(ent
, 0);
4332 memcg
= mem_cgroup_lookup(id
);
4335 * We uncharge this because swap is freed.
4336 * This memcg can be obsolete one. We avoid calling css_tryget
4338 if (!mem_cgroup_is_root(memcg
))
4339 res_counter_uncharge(&memcg
->memsw
, PAGE_SIZE
);
4340 mem_cgroup_swap_statistics(memcg
, false);
4341 mem_cgroup_put(memcg
);
4347 * mem_cgroup_move_swap_account - move swap charge and swap_cgroup's record.
4348 * @entry: swap entry to be moved
4349 * @from: mem_cgroup which the entry is moved from
4350 * @to: mem_cgroup which the entry is moved to
4352 * It succeeds only when the swap_cgroup's record for this entry is the same
4353 * as the mem_cgroup's id of @from.
4355 * Returns 0 on success, -EINVAL on failure.
4357 * The caller must have charged to @to, IOW, called res_counter_charge() about
4358 * both res and memsw, and called css_get().
4360 static int mem_cgroup_move_swap_account(swp_entry_t entry
,
4361 struct mem_cgroup
*from
, struct mem_cgroup
*to
)
4363 unsigned short old_id
, new_id
;
4365 old_id
= css_id(&from
->css
);
4366 new_id
= css_id(&to
->css
);
4368 if (swap_cgroup_cmpxchg(entry
, old_id
, new_id
) == old_id
) {
4369 mem_cgroup_swap_statistics(from
, false);
4370 mem_cgroup_swap_statistics(to
, true);
4372 * This function is only called from task migration context now.
4373 * It postpones res_counter and refcount handling till the end
4374 * of task migration(mem_cgroup_clear_mc()) for performance
4375 * improvement. But we cannot postpone mem_cgroup_get(to)
4376 * because if the process that has been moved to @to does
4377 * swap-in, the refcount of @to might be decreased to 0.
4385 static inline int mem_cgroup_move_swap_account(swp_entry_t entry
,
4386 struct mem_cgroup
*from
, struct mem_cgroup
*to
)
4393 * Before starting migration, account PAGE_SIZE to mem_cgroup that the old
4396 void mem_cgroup_prepare_migration(struct page
*page
, struct page
*newpage
,
4397 struct mem_cgroup
**memcgp
)
4399 struct mem_cgroup
*memcg
= NULL
;
4400 unsigned int nr_pages
= 1;
4401 struct page_cgroup
*pc
;
4402 enum charge_type ctype
;
4406 if (mem_cgroup_disabled())
4409 if (PageTransHuge(page
))
4410 nr_pages
<<= compound_order(page
);
4412 pc
= lookup_page_cgroup(page
);
4413 lock_page_cgroup(pc
);
4414 if (PageCgroupUsed(pc
)) {
4415 memcg
= pc
->mem_cgroup
;
4416 css_get(&memcg
->css
);
4418 * At migrating an anonymous page, its mapcount goes down
4419 * to 0 and uncharge() will be called. But, even if it's fully
4420 * unmapped, migration may fail and this page has to be
4421 * charged again. We set MIGRATION flag here and delay uncharge
4422 * until end_migration() is called
4424 * Corner Case Thinking
4426 * When the old page was mapped as Anon and it's unmap-and-freed
4427 * while migration was ongoing.
4428 * If unmap finds the old page, uncharge() of it will be delayed
4429 * until end_migration(). If unmap finds a new page, it's
4430 * uncharged when it make mapcount to be 1->0. If unmap code
4431 * finds swap_migration_entry, the new page will not be mapped
4432 * and end_migration() will find it(mapcount==0).
4435 * When the old page was mapped but migraion fails, the kernel
4436 * remaps it. A charge for it is kept by MIGRATION flag even
4437 * if mapcount goes down to 0. We can do remap successfully
4438 * without charging it again.
4441 * The "old" page is under lock_page() until the end of
4442 * migration, so, the old page itself will not be swapped-out.
4443 * If the new page is swapped out before end_migraton, our
4444 * hook to usual swap-out path will catch the event.
4447 SetPageCgroupMigration(pc
);
4449 unlock_page_cgroup(pc
);
4451 * If the page is not charged at this point,
4459 * We charge new page before it's used/mapped. So, even if unlock_page()
4460 * is called before end_migration, we can catch all events on this new
4461 * page. In the case new page is migrated but not remapped, new page's
4462 * mapcount will be finally 0 and we call uncharge in end_migration().
4465 ctype
= MEM_CGROUP_CHARGE_TYPE_ANON
;
4467 ctype
= MEM_CGROUP_CHARGE_TYPE_CACHE
;
4469 * The page is committed to the memcg, but it's not actually
4470 * charged to the res_counter since we plan on replacing the
4471 * old one and only one page is going to be left afterwards.
4473 __mem_cgroup_commit_charge(memcg
, newpage
, nr_pages
, ctype
, false);
4476 /* remove redundant charge if migration failed*/
4477 void mem_cgroup_end_migration(struct mem_cgroup
*memcg
,
4478 struct page
*oldpage
, struct page
*newpage
, bool migration_ok
)
4480 struct page
*used
, *unused
;
4481 struct page_cgroup
*pc
;
4487 if (!migration_ok
) {
4494 anon
= PageAnon(used
);
4495 __mem_cgroup_uncharge_common(unused
,
4496 anon
? MEM_CGROUP_CHARGE_TYPE_ANON
4497 : MEM_CGROUP_CHARGE_TYPE_CACHE
,
4499 css_put(&memcg
->css
);
4501 * We disallowed uncharge of pages under migration because mapcount
4502 * of the page goes down to zero, temporarly.
4503 * Clear the flag and check the page should be charged.
4505 pc
= lookup_page_cgroup(oldpage
);
4506 lock_page_cgroup(pc
);
4507 ClearPageCgroupMigration(pc
);
4508 unlock_page_cgroup(pc
);
4511 * If a page is a file cache, radix-tree replacement is very atomic
4512 * and we can skip this check. When it was an Anon page, its mapcount
4513 * goes down to 0. But because we added MIGRATION flage, it's not
4514 * uncharged yet. There are several case but page->mapcount check
4515 * and USED bit check in mem_cgroup_uncharge_page() will do enough
4516 * check. (see prepare_charge() also)
4519 mem_cgroup_uncharge_page(used
);
4523 * At replace page cache, newpage is not under any memcg but it's on
4524 * LRU. So, this function doesn't touch res_counter but handles LRU
4525 * in correct way. Both pages are locked so we cannot race with uncharge.
4527 void mem_cgroup_replace_page_cache(struct page
*oldpage
,
4528 struct page
*newpage
)
4530 struct mem_cgroup
*memcg
= NULL
;
4531 struct page_cgroup
*pc
;
4532 enum charge_type type
= MEM_CGROUP_CHARGE_TYPE_CACHE
;
4534 if (mem_cgroup_disabled())
4537 pc
= lookup_page_cgroup(oldpage
);
4538 /* fix accounting on old pages */
4539 lock_page_cgroup(pc
);
4540 if (PageCgroupUsed(pc
)) {
4541 memcg
= pc
->mem_cgroup
;
4542 mem_cgroup_charge_statistics(memcg
, oldpage
, false, -1);
4543 ClearPageCgroupUsed(pc
);
4545 unlock_page_cgroup(pc
);
4548 * When called from shmem_replace_page(), in some cases the
4549 * oldpage has already been charged, and in some cases not.
4554 * Even if newpage->mapping was NULL before starting replacement,
4555 * the newpage may be on LRU(or pagevec for LRU) already. We lock
4556 * LRU while we overwrite pc->mem_cgroup.
4558 __mem_cgroup_commit_charge(memcg
, newpage
, 1, type
, true);
4561 #ifdef CONFIG_DEBUG_VM
4562 static struct page_cgroup
*lookup_page_cgroup_used(struct page
*page
)
4564 struct page_cgroup
*pc
;
4566 pc
= lookup_page_cgroup(page
);
4568 * Can be NULL while feeding pages into the page allocator for
4569 * the first time, i.e. during boot or memory hotplug;
4570 * or when mem_cgroup_disabled().
4572 if (likely(pc
) && PageCgroupUsed(pc
))
4577 bool mem_cgroup_bad_page_check(struct page
*page
)
4579 if (mem_cgroup_disabled())
4582 return lookup_page_cgroup_used(page
) != NULL
;
4585 void mem_cgroup_print_bad_page(struct page
*page
)
4587 struct page_cgroup
*pc
;
4589 pc
= lookup_page_cgroup_used(page
);
4591 pr_alert("pc:%p pc->flags:%lx pc->mem_cgroup:%p\n",
4592 pc
, pc
->flags
, pc
->mem_cgroup
);
4597 static int mem_cgroup_resize_limit(struct mem_cgroup
*memcg
,
4598 unsigned long long val
)
4601 u64 memswlimit
, memlimit
;
4603 int children
= mem_cgroup_count_children(memcg
);
4604 u64 curusage
, oldusage
;
4608 * For keeping hierarchical_reclaim simple, how long we should retry
4609 * is depends on callers. We set our retry-count to be function
4610 * of # of children which we should visit in this loop.
4612 retry_count
= MEM_CGROUP_RECLAIM_RETRIES
* children
;
4614 oldusage
= res_counter_read_u64(&memcg
->res
, RES_USAGE
);
4617 while (retry_count
) {
4618 if (signal_pending(current
)) {
4623 * Rather than hide all in some function, I do this in
4624 * open coded manner. You see what this really does.
4625 * We have to guarantee memcg->res.limit <= memcg->memsw.limit.
4627 mutex_lock(&set_limit_mutex
);
4628 memswlimit
= res_counter_read_u64(&memcg
->memsw
, RES_LIMIT
);
4629 if (memswlimit
< val
) {
4631 mutex_unlock(&set_limit_mutex
);
4635 memlimit
= res_counter_read_u64(&memcg
->res
, RES_LIMIT
);
4639 ret
= res_counter_set_limit(&memcg
->res
, val
);
4641 if (memswlimit
== val
)
4642 memcg
->memsw_is_minimum
= true;
4644 memcg
->memsw_is_minimum
= false;
4646 mutex_unlock(&set_limit_mutex
);
4651 mem_cgroup_reclaim(memcg
, GFP_KERNEL
,
4652 MEM_CGROUP_RECLAIM_SHRINK
);
4653 curusage
= res_counter_read_u64(&memcg
->res
, RES_USAGE
);
4654 /* Usage is reduced ? */
4655 if (curusage
>= oldusage
)
4658 oldusage
= curusage
;
4660 if (!ret
&& enlarge
)
4661 memcg_oom_recover(memcg
);
4666 static int mem_cgroup_resize_memsw_limit(struct mem_cgroup
*memcg
,
4667 unsigned long long val
)
4670 u64 memlimit
, memswlimit
, oldusage
, curusage
;
4671 int children
= mem_cgroup_count_children(memcg
);
4675 /* see mem_cgroup_resize_res_limit */
4676 retry_count
= children
* MEM_CGROUP_RECLAIM_RETRIES
;
4677 oldusage
= res_counter_read_u64(&memcg
->memsw
, RES_USAGE
);
4678 while (retry_count
) {
4679 if (signal_pending(current
)) {
4684 * Rather than hide all in some function, I do this in
4685 * open coded manner. You see what this really does.
4686 * We have to guarantee memcg->res.limit <= memcg->memsw.limit.
4688 mutex_lock(&set_limit_mutex
);
4689 memlimit
= res_counter_read_u64(&memcg
->res
, RES_LIMIT
);
4690 if (memlimit
> val
) {
4692 mutex_unlock(&set_limit_mutex
);
4695 memswlimit
= res_counter_read_u64(&memcg
->memsw
, RES_LIMIT
);
4696 if (memswlimit
< val
)
4698 ret
= res_counter_set_limit(&memcg
->memsw
, val
);
4700 if (memlimit
== val
)
4701 memcg
->memsw_is_minimum
= true;
4703 memcg
->memsw_is_minimum
= false;
4705 mutex_unlock(&set_limit_mutex
);
4710 mem_cgroup_reclaim(memcg
, GFP_KERNEL
,
4711 MEM_CGROUP_RECLAIM_NOSWAP
|
4712 MEM_CGROUP_RECLAIM_SHRINK
);
4713 curusage
= res_counter_read_u64(&memcg
->memsw
, RES_USAGE
);
4714 /* Usage is reduced ? */
4715 if (curusage
>= oldusage
)
4718 oldusage
= curusage
;
4720 if (!ret
&& enlarge
)
4721 memcg_oom_recover(memcg
);
4725 unsigned long mem_cgroup_soft_limit_reclaim(struct zone
*zone
, int order
,
4727 unsigned long *total_scanned
)
4729 unsigned long nr_reclaimed
= 0;
4730 struct mem_cgroup_per_zone
*mz
, *next_mz
= NULL
;
4731 unsigned long reclaimed
;
4733 struct mem_cgroup_tree_per_zone
*mctz
;
4734 unsigned long long excess
;
4735 unsigned long nr_scanned
;
4740 mctz
= soft_limit_tree_node_zone(zone_to_nid(zone
), zone_idx(zone
));
4742 * This loop can run a while, specially if mem_cgroup's continuously
4743 * keep exceeding their soft limit and putting the system under
4750 mz
= mem_cgroup_largest_soft_limit_node(mctz
);
4755 reclaimed
= mem_cgroup_soft_reclaim(mz
->memcg
, zone
,
4756 gfp_mask
, &nr_scanned
);
4757 nr_reclaimed
+= reclaimed
;
4758 *total_scanned
+= nr_scanned
;
4759 spin_lock(&mctz
->lock
);
4762 * If we failed to reclaim anything from this memory cgroup
4763 * it is time to move on to the next cgroup
4769 * Loop until we find yet another one.
4771 * By the time we get the soft_limit lock
4772 * again, someone might have aded the
4773 * group back on the RB tree. Iterate to
4774 * make sure we get a different mem.
4775 * mem_cgroup_largest_soft_limit_node returns
4776 * NULL if no other cgroup is present on
4780 __mem_cgroup_largest_soft_limit_node(mctz
);
4782 css_put(&next_mz
->memcg
->css
);
4783 else /* next_mz == NULL or other memcg */
4787 __mem_cgroup_remove_exceeded(mz
->memcg
, mz
, mctz
);
4788 excess
= res_counter_soft_limit_excess(&mz
->memcg
->res
);
4790 * One school of thought says that we should not add
4791 * back the node to the tree if reclaim returns 0.
4792 * But our reclaim could return 0, simply because due
4793 * to priority we are exposing a smaller subset of
4794 * memory to reclaim from. Consider this as a longer
4797 /* If excess == 0, no tree ops */
4798 __mem_cgroup_insert_exceeded(mz
->memcg
, mz
, mctz
, excess
);
4799 spin_unlock(&mctz
->lock
);
4800 css_put(&mz
->memcg
->css
);
4803 * Could not reclaim anything and there are no more
4804 * mem cgroups to try or we seem to be looping without
4805 * reclaiming anything.
4807 if (!nr_reclaimed
&&
4809 loop
> MEM_CGROUP_MAX_SOFT_LIMIT_RECLAIM_LOOPS
))
4811 } while (!nr_reclaimed
);
4813 css_put(&next_mz
->memcg
->css
);
4814 return nr_reclaimed
;
4818 * mem_cgroup_force_empty_list - clears LRU of a group
4819 * @memcg: group to clear
4822 * @lru: lru to to clear
4824 * Traverse a specified page_cgroup list and try to drop them all. This doesn't
4825 * reclaim the pages page themselves - pages are moved to the parent (or root)
4828 static void mem_cgroup_force_empty_list(struct mem_cgroup
*memcg
,
4829 int node
, int zid
, enum lru_list lru
)
4831 struct lruvec
*lruvec
;
4832 unsigned long flags
;
4833 struct list_head
*list
;
4837 zone
= &NODE_DATA(node
)->node_zones
[zid
];
4838 lruvec
= mem_cgroup_zone_lruvec(zone
, memcg
);
4839 list
= &lruvec
->lists
[lru
];
4843 struct page_cgroup
*pc
;
4846 spin_lock_irqsave(&zone
->lru_lock
, flags
);
4847 if (list_empty(list
)) {
4848 spin_unlock_irqrestore(&zone
->lru_lock
, flags
);
4851 page
= list_entry(list
->prev
, struct page
, lru
);
4853 list_move(&page
->lru
, list
);
4855 spin_unlock_irqrestore(&zone
->lru_lock
, flags
);
4858 spin_unlock_irqrestore(&zone
->lru_lock
, flags
);
4860 pc
= lookup_page_cgroup(page
);
4862 if (mem_cgroup_move_parent(page
, pc
, memcg
)) {
4863 /* found lock contention or "pc" is obsolete. */
4868 } while (!list_empty(list
));
4872 * make mem_cgroup's charge to be 0 if there is no task by moving
4873 * all the charges and pages to the parent.
4874 * This enables deleting this mem_cgroup.
4876 * Caller is responsible for holding css reference on the memcg.
4878 static void mem_cgroup_reparent_charges(struct mem_cgroup
*memcg
)
4884 /* This is for making all *used* pages to be on LRU. */
4885 lru_add_drain_all();
4886 drain_all_stock_sync(memcg
);
4887 mem_cgroup_start_move(memcg
);
4888 for_each_node_state(node
, N_MEMORY
) {
4889 for (zid
= 0; zid
< MAX_NR_ZONES
; zid
++) {
4892 mem_cgroup_force_empty_list(memcg
,
4897 mem_cgroup_end_move(memcg
);
4898 memcg_oom_recover(memcg
);
4902 * Kernel memory may not necessarily be trackable to a specific
4903 * process. So they are not migrated, and therefore we can't
4904 * expect their value to drop to 0 here.
4905 * Having res filled up with kmem only is enough.
4907 * This is a safety check because mem_cgroup_force_empty_list
4908 * could have raced with mem_cgroup_replace_page_cache callers
4909 * so the lru seemed empty but the page could have been added
4910 * right after the check. RES_USAGE should be safe as we always
4911 * charge before adding to the LRU.
4913 usage
= res_counter_read_u64(&memcg
->res
, RES_USAGE
) -
4914 res_counter_read_u64(&memcg
->kmem
, RES_USAGE
);
4915 } while (usage
> 0);
4919 * This mainly exists for tests during the setting of set of use_hierarchy.
4920 * Since this is the very setting we are changing, the current hierarchy value
4923 static inline bool __memcg_has_children(struct mem_cgroup
*memcg
)
4927 /* bounce at first found */
4928 cgroup_for_each_child(pos
, memcg
->css
.cgroup
)
4934 * Must be called with memcg_create_mutex held, unless the cgroup is guaranteed
4935 * to be already dead (as in mem_cgroup_force_empty, for instance). This is
4936 * from mem_cgroup_count_children(), in the sense that we don't really care how
4937 * many children we have; we only need to know if we have any. It also counts
4938 * any memcg without hierarchy as infertile.
4940 static inline bool memcg_has_children(struct mem_cgroup
*memcg
)
4942 return memcg
->use_hierarchy
&& __memcg_has_children(memcg
);
4946 * Reclaims as many pages from the given memcg as possible and moves
4947 * the rest to the parent.
4949 * Caller is responsible for holding css reference for memcg.
4951 static int mem_cgroup_force_empty(struct mem_cgroup
*memcg
)
4953 int nr_retries
= MEM_CGROUP_RECLAIM_RETRIES
;
4954 struct cgroup
*cgrp
= memcg
->css
.cgroup
;
4956 /* returns EBUSY if there is a task or if we come here twice. */
4957 if (cgroup_task_count(cgrp
) || !list_empty(&cgrp
->children
))
4960 /* we call try-to-free pages for make this cgroup empty */
4961 lru_add_drain_all();
4962 /* try to free all pages in this cgroup */
4963 while (nr_retries
&& res_counter_read_u64(&memcg
->res
, RES_USAGE
) > 0) {
4966 if (signal_pending(current
))
4969 progress
= try_to_free_mem_cgroup_pages(memcg
, GFP_KERNEL
,
4973 /* maybe some writeback is necessary */
4974 congestion_wait(BLK_RW_ASYNC
, HZ
/10);
4979 mem_cgroup_reparent_charges(memcg
);
4984 static int mem_cgroup_force_empty_write(struct cgroup
*cont
, unsigned int event
)
4986 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cont
);
4989 if (mem_cgroup_is_root(memcg
))
4991 css_get(&memcg
->css
);
4992 ret
= mem_cgroup_force_empty(memcg
);
4993 css_put(&memcg
->css
);
4999 static u64
mem_cgroup_hierarchy_read(struct cgroup
*cont
, struct cftype
*cft
)
5001 return mem_cgroup_from_cont(cont
)->use_hierarchy
;
5004 static int mem_cgroup_hierarchy_write(struct cgroup
*cont
, struct cftype
*cft
,
5008 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cont
);
5009 struct cgroup
*parent
= cont
->parent
;
5010 struct mem_cgroup
*parent_memcg
= NULL
;
5013 parent_memcg
= mem_cgroup_from_cont(parent
);
5015 mutex_lock(&memcg_create_mutex
);
5017 if (memcg
->use_hierarchy
== val
)
5021 * If parent's use_hierarchy is set, we can't make any modifications
5022 * in the child subtrees. If it is unset, then the change can
5023 * occur, provided the current cgroup has no children.
5025 * For the root cgroup, parent_mem is NULL, we allow value to be
5026 * set if there are no children.
5028 if ((!parent_memcg
|| !parent_memcg
->use_hierarchy
) &&
5029 (val
== 1 || val
== 0)) {
5030 if (!__memcg_has_children(memcg
))
5031 memcg
->use_hierarchy
= val
;
5038 mutex_unlock(&memcg_create_mutex
);
5044 static unsigned long mem_cgroup_recursive_stat(struct mem_cgroup
*memcg
,
5045 enum mem_cgroup_stat_index idx
)
5047 struct mem_cgroup
*iter
;
5050 /* Per-cpu values can be negative, use a signed accumulator */
5051 for_each_mem_cgroup_tree(iter
, memcg
)
5052 val
+= mem_cgroup_read_stat(iter
, idx
);
5054 if (val
< 0) /* race ? */
5059 static inline u64
mem_cgroup_usage(struct mem_cgroup
*memcg
, bool swap
)
5063 if (!mem_cgroup_is_root(memcg
)) {
5065 return res_counter_read_u64(&memcg
->res
, RES_USAGE
);
5067 return res_counter_read_u64(&memcg
->memsw
, RES_USAGE
);
5071 * Transparent hugepages are still accounted for in MEM_CGROUP_STAT_RSS
5072 * as well as in MEM_CGROUP_STAT_RSS_HUGE.
5074 val
= mem_cgroup_recursive_stat(memcg
, MEM_CGROUP_STAT_CACHE
);
5075 val
+= mem_cgroup_recursive_stat(memcg
, MEM_CGROUP_STAT_RSS
);
5078 val
+= mem_cgroup_recursive_stat(memcg
, MEM_CGROUP_STAT_SWAP
);
5080 return val
<< PAGE_SHIFT
;
5083 static ssize_t
mem_cgroup_read(struct cgroup
*cont
, struct cftype
*cft
,
5084 struct file
*file
, char __user
*buf
,
5085 size_t nbytes
, loff_t
*ppos
)
5087 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cont
);
5093 type
= MEMFILE_TYPE(cft
->private);
5094 name
= MEMFILE_ATTR(cft
->private);
5098 if (name
== RES_USAGE
)
5099 val
= mem_cgroup_usage(memcg
, false);
5101 val
= res_counter_read_u64(&memcg
->res
, name
);
5104 if (name
== RES_USAGE
)
5105 val
= mem_cgroup_usage(memcg
, true);
5107 val
= res_counter_read_u64(&memcg
->memsw
, name
);
5110 val
= res_counter_read_u64(&memcg
->kmem
, name
);
5116 len
= scnprintf(str
, sizeof(str
), "%llu\n", (unsigned long long)val
);
5117 return simple_read_from_buffer(buf
, nbytes
, ppos
, str
, len
);
5120 static int memcg_update_kmem_limit(struct cgroup
*cont
, u64 val
)
5123 #ifdef CONFIG_MEMCG_KMEM
5124 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cont
);
5126 * For simplicity, we won't allow this to be disabled. It also can't
5127 * be changed if the cgroup has children already, or if tasks had
5130 * If tasks join before we set the limit, a person looking at
5131 * kmem.usage_in_bytes will have no way to determine when it took
5132 * place, which makes the value quite meaningless.
5134 * After it first became limited, changes in the value of the limit are
5135 * of course permitted.
5137 mutex_lock(&memcg_create_mutex
);
5138 mutex_lock(&set_limit_mutex
);
5139 if (!memcg
->kmem_account_flags
&& val
!= RESOURCE_MAX
) {
5140 if (cgroup_task_count(cont
) || memcg_has_children(memcg
)) {
5144 ret
= res_counter_set_limit(&memcg
->kmem
, val
);
5147 ret
= memcg_update_cache_sizes(memcg
);
5149 res_counter_set_limit(&memcg
->kmem
, RESOURCE_MAX
);
5152 static_key_slow_inc(&memcg_kmem_enabled_key
);
5154 * setting the active bit after the inc will guarantee no one
5155 * starts accounting before all call sites are patched
5157 memcg_kmem_set_active(memcg
);
5160 * kmem charges can outlive the cgroup. In the case of slab
5161 * pages, for instance, a page contain objects from various
5162 * processes, so it is unfeasible to migrate them away. We
5163 * need to reference count the memcg because of that.
5165 mem_cgroup_get(memcg
);
5167 ret
= res_counter_set_limit(&memcg
->kmem
, val
);
5169 mutex_unlock(&set_limit_mutex
);
5170 mutex_unlock(&memcg_create_mutex
);
5175 #ifdef CONFIG_MEMCG_KMEM
5176 static int memcg_propagate_kmem(struct mem_cgroup
*memcg
)
5179 struct mem_cgroup
*parent
= parent_mem_cgroup(memcg
);
5183 memcg
->kmem_account_flags
= parent
->kmem_account_flags
;
5185 * When that happen, we need to disable the static branch only on those
5186 * memcgs that enabled it. To achieve this, we would be forced to
5187 * complicate the code by keeping track of which memcgs were the ones
5188 * that actually enabled limits, and which ones got it from its
5191 * It is a lot simpler just to do static_key_slow_inc() on every child
5192 * that is accounted.
5194 if (!memcg_kmem_is_active(memcg
))
5198 * destroy(), called if we fail, will issue static_key_slow_inc() and
5199 * mem_cgroup_put() if kmem is enabled. We have to either call them
5200 * unconditionally, or clear the KMEM_ACTIVE flag. I personally find
5201 * this more consistent, since it always leads to the same destroy path
5203 mem_cgroup_get(memcg
);
5204 static_key_slow_inc(&memcg_kmem_enabled_key
);
5206 mutex_lock(&set_limit_mutex
);
5207 ret
= memcg_update_cache_sizes(memcg
);
5208 mutex_unlock(&set_limit_mutex
);
5212 #endif /* CONFIG_MEMCG_KMEM */
5215 * The user of this function is...
5218 static int mem_cgroup_write(struct cgroup
*cont
, struct cftype
*cft
,
5221 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cont
);
5224 unsigned long long val
;
5227 type
= MEMFILE_TYPE(cft
->private);
5228 name
= MEMFILE_ATTR(cft
->private);
5232 if (mem_cgroup_is_root(memcg
)) { /* Can't set limit on root */
5236 /* This function does all necessary parse...reuse it */
5237 ret
= res_counter_memparse_write_strategy(buffer
, &val
);
5241 ret
= mem_cgroup_resize_limit(memcg
, val
);
5242 else if (type
== _MEMSWAP
)
5243 ret
= mem_cgroup_resize_memsw_limit(memcg
, val
);
5244 else if (type
== _KMEM
)
5245 ret
= memcg_update_kmem_limit(cont
, val
);
5249 case RES_SOFT_LIMIT
:
5250 ret
= res_counter_memparse_write_strategy(buffer
, &val
);
5254 * For memsw, soft limits are hard to implement in terms
5255 * of semantics, for now, we support soft limits for
5256 * control without swap
5259 ret
= res_counter_set_soft_limit(&memcg
->res
, val
);
5264 ret
= -EINVAL
; /* should be BUG() ? */
5270 static void memcg_get_hierarchical_limit(struct mem_cgroup
*memcg
,
5271 unsigned long long *mem_limit
, unsigned long long *memsw_limit
)
5273 struct cgroup
*cgroup
;
5274 unsigned long long min_limit
, min_memsw_limit
, tmp
;
5276 min_limit
= res_counter_read_u64(&memcg
->res
, RES_LIMIT
);
5277 min_memsw_limit
= res_counter_read_u64(&memcg
->memsw
, RES_LIMIT
);
5278 cgroup
= memcg
->css
.cgroup
;
5279 if (!memcg
->use_hierarchy
)
5282 while (cgroup
->parent
) {
5283 cgroup
= cgroup
->parent
;
5284 memcg
= mem_cgroup_from_cont(cgroup
);
5285 if (!memcg
->use_hierarchy
)
5287 tmp
= res_counter_read_u64(&memcg
->res
, RES_LIMIT
);
5288 min_limit
= min(min_limit
, tmp
);
5289 tmp
= res_counter_read_u64(&memcg
->memsw
, RES_LIMIT
);
5290 min_memsw_limit
= min(min_memsw_limit
, tmp
);
5293 *mem_limit
= min_limit
;
5294 *memsw_limit
= min_memsw_limit
;
5297 static int mem_cgroup_reset(struct cgroup
*cont
, unsigned int event
)
5299 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cont
);
5303 type
= MEMFILE_TYPE(event
);
5304 name
= MEMFILE_ATTR(event
);
5309 res_counter_reset_max(&memcg
->res
);
5310 else if (type
== _MEMSWAP
)
5311 res_counter_reset_max(&memcg
->memsw
);
5312 else if (type
== _KMEM
)
5313 res_counter_reset_max(&memcg
->kmem
);
5319 res_counter_reset_failcnt(&memcg
->res
);
5320 else if (type
== _MEMSWAP
)
5321 res_counter_reset_failcnt(&memcg
->memsw
);
5322 else if (type
== _KMEM
)
5323 res_counter_reset_failcnt(&memcg
->kmem
);
5332 static u64
mem_cgroup_move_charge_read(struct cgroup
*cgrp
,
5335 return mem_cgroup_from_cont(cgrp
)->move_charge_at_immigrate
;
5339 static int mem_cgroup_move_charge_write(struct cgroup
*cgrp
,
5340 struct cftype
*cft
, u64 val
)
5342 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cgrp
);
5344 if (val
>= (1 << NR_MOVE_TYPE
))
5348 * No kind of locking is needed in here, because ->can_attach() will
5349 * check this value once in the beginning of the process, and then carry
5350 * on with stale data. This means that changes to this value will only
5351 * affect task migrations starting after the change.
5353 memcg
->move_charge_at_immigrate
= val
;
5357 static int mem_cgroup_move_charge_write(struct cgroup
*cgrp
,
5358 struct cftype
*cft
, u64 val
)
5365 static int memcg_numa_stat_show(struct cgroup
*cont
, struct cftype
*cft
,
5369 unsigned long total_nr
, file_nr
, anon_nr
, unevictable_nr
;
5370 unsigned long node_nr
;
5371 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cont
);
5373 total_nr
= mem_cgroup_nr_lru_pages(memcg
, LRU_ALL
);
5374 seq_printf(m
, "total=%lu", total_nr
);
5375 for_each_node_state(nid
, N_MEMORY
) {
5376 node_nr
= mem_cgroup_node_nr_lru_pages(memcg
, nid
, LRU_ALL
);
5377 seq_printf(m
, " N%d=%lu", nid
, node_nr
);
5381 file_nr
= mem_cgroup_nr_lru_pages(memcg
, LRU_ALL_FILE
);
5382 seq_printf(m
, "file=%lu", file_nr
);
5383 for_each_node_state(nid
, N_MEMORY
) {
5384 node_nr
= mem_cgroup_node_nr_lru_pages(memcg
, nid
,
5386 seq_printf(m
, " N%d=%lu", nid
, node_nr
);
5390 anon_nr
= mem_cgroup_nr_lru_pages(memcg
, LRU_ALL_ANON
);
5391 seq_printf(m
, "anon=%lu", anon_nr
);
5392 for_each_node_state(nid
, N_MEMORY
) {
5393 node_nr
= mem_cgroup_node_nr_lru_pages(memcg
, nid
,
5395 seq_printf(m
, " N%d=%lu", nid
, node_nr
);
5399 unevictable_nr
= mem_cgroup_nr_lru_pages(memcg
, BIT(LRU_UNEVICTABLE
));
5400 seq_printf(m
, "unevictable=%lu", unevictable_nr
);
5401 for_each_node_state(nid
, N_MEMORY
) {
5402 node_nr
= mem_cgroup_node_nr_lru_pages(memcg
, nid
,
5403 BIT(LRU_UNEVICTABLE
));
5404 seq_printf(m
, " N%d=%lu", nid
, node_nr
);
5409 #endif /* CONFIG_NUMA */
5411 static inline void mem_cgroup_lru_names_not_uptodate(void)
5413 BUILD_BUG_ON(ARRAY_SIZE(mem_cgroup_lru_names
) != NR_LRU_LISTS
);
5416 static int memcg_stat_show(struct cgroup
*cont
, struct cftype
*cft
,
5419 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cont
);
5420 struct mem_cgroup
*mi
;
5423 for (i
= 0; i
< MEM_CGROUP_STAT_NSTATS
; i
++) {
5424 if (i
== MEM_CGROUP_STAT_SWAP
&& !do_swap_account
)
5426 seq_printf(m
, "%s %ld\n", mem_cgroup_stat_names
[i
],
5427 mem_cgroup_read_stat(memcg
, i
) * PAGE_SIZE
);
5430 for (i
= 0; i
< MEM_CGROUP_EVENTS_NSTATS
; i
++)
5431 seq_printf(m
, "%s %lu\n", mem_cgroup_events_names
[i
],
5432 mem_cgroup_read_events(memcg
, i
));
5434 for (i
= 0; i
< NR_LRU_LISTS
; i
++)
5435 seq_printf(m
, "%s %lu\n", mem_cgroup_lru_names
[i
],
5436 mem_cgroup_nr_lru_pages(memcg
, BIT(i
)) * PAGE_SIZE
);
5438 /* Hierarchical information */
5440 unsigned long long limit
, memsw_limit
;
5441 memcg_get_hierarchical_limit(memcg
, &limit
, &memsw_limit
);
5442 seq_printf(m
, "hierarchical_memory_limit %llu\n", limit
);
5443 if (do_swap_account
)
5444 seq_printf(m
, "hierarchical_memsw_limit %llu\n",
5448 for (i
= 0; i
< MEM_CGROUP_STAT_NSTATS
; i
++) {
5451 if (i
== MEM_CGROUP_STAT_SWAP
&& !do_swap_account
)
5453 for_each_mem_cgroup_tree(mi
, memcg
)
5454 val
+= mem_cgroup_read_stat(mi
, i
) * PAGE_SIZE
;
5455 seq_printf(m
, "total_%s %lld\n", mem_cgroup_stat_names
[i
], val
);
5458 for (i
= 0; i
< MEM_CGROUP_EVENTS_NSTATS
; i
++) {
5459 unsigned long long val
= 0;
5461 for_each_mem_cgroup_tree(mi
, memcg
)
5462 val
+= mem_cgroup_read_events(mi
, i
);
5463 seq_printf(m
, "total_%s %llu\n",
5464 mem_cgroup_events_names
[i
], val
);
5467 for (i
= 0; i
< NR_LRU_LISTS
; i
++) {
5468 unsigned long long val
= 0;
5470 for_each_mem_cgroup_tree(mi
, memcg
)
5471 val
+= mem_cgroup_nr_lru_pages(mi
, BIT(i
)) * PAGE_SIZE
;
5472 seq_printf(m
, "total_%s %llu\n", mem_cgroup_lru_names
[i
], val
);
5475 #ifdef CONFIG_DEBUG_VM
5478 struct mem_cgroup_per_zone
*mz
;
5479 struct zone_reclaim_stat
*rstat
;
5480 unsigned long recent_rotated
[2] = {0, 0};
5481 unsigned long recent_scanned
[2] = {0, 0};
5483 for_each_online_node(nid
)
5484 for (zid
= 0; zid
< MAX_NR_ZONES
; zid
++) {
5485 mz
= mem_cgroup_zoneinfo(memcg
, nid
, zid
);
5486 rstat
= &mz
->lruvec
.reclaim_stat
;
5488 recent_rotated
[0] += rstat
->recent_rotated
[0];
5489 recent_rotated
[1] += rstat
->recent_rotated
[1];
5490 recent_scanned
[0] += rstat
->recent_scanned
[0];
5491 recent_scanned
[1] += rstat
->recent_scanned
[1];
5493 seq_printf(m
, "recent_rotated_anon %lu\n", recent_rotated
[0]);
5494 seq_printf(m
, "recent_rotated_file %lu\n", recent_rotated
[1]);
5495 seq_printf(m
, "recent_scanned_anon %lu\n", recent_scanned
[0]);
5496 seq_printf(m
, "recent_scanned_file %lu\n", recent_scanned
[1]);
5503 static u64
mem_cgroup_swappiness_read(struct cgroup
*cgrp
, struct cftype
*cft
)
5505 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cgrp
);
5507 return mem_cgroup_swappiness(memcg
);
5510 static int mem_cgroup_swappiness_write(struct cgroup
*cgrp
, struct cftype
*cft
,
5513 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cgrp
);
5514 struct mem_cgroup
*parent
;
5519 if (cgrp
->parent
== NULL
)
5522 parent
= mem_cgroup_from_cont(cgrp
->parent
);
5524 mutex_lock(&memcg_create_mutex
);
5526 /* If under hierarchy, only empty-root can set this value */
5527 if ((parent
->use_hierarchy
) || memcg_has_children(memcg
)) {
5528 mutex_unlock(&memcg_create_mutex
);
5532 memcg
->swappiness
= val
;
5534 mutex_unlock(&memcg_create_mutex
);
5539 static void __mem_cgroup_threshold(struct mem_cgroup
*memcg
, bool swap
)
5541 struct mem_cgroup_threshold_ary
*t
;
5547 t
= rcu_dereference(memcg
->thresholds
.primary
);
5549 t
= rcu_dereference(memcg
->memsw_thresholds
.primary
);
5554 usage
= mem_cgroup_usage(memcg
, swap
);
5557 * current_threshold points to threshold just below or equal to usage.
5558 * If it's not true, a threshold was crossed after last
5559 * call of __mem_cgroup_threshold().
5561 i
= t
->current_threshold
;
5564 * Iterate backward over array of thresholds starting from
5565 * current_threshold and check if a threshold is crossed.
5566 * If none of thresholds below usage is crossed, we read
5567 * only one element of the array here.
5569 for (; i
>= 0 && unlikely(t
->entries
[i
].threshold
> usage
); i
--)
5570 eventfd_signal(t
->entries
[i
].eventfd
, 1);
5572 /* i = current_threshold + 1 */
5576 * Iterate forward over array of thresholds starting from
5577 * current_threshold+1 and check if a threshold is crossed.
5578 * If none of thresholds above usage is crossed, we read
5579 * only one element of the array here.
5581 for (; i
< t
->size
&& unlikely(t
->entries
[i
].threshold
<= usage
); i
++)
5582 eventfd_signal(t
->entries
[i
].eventfd
, 1);
5584 /* Update current_threshold */
5585 t
->current_threshold
= i
- 1;
5590 static void mem_cgroup_threshold(struct mem_cgroup
*memcg
)
5593 __mem_cgroup_threshold(memcg
, false);
5594 if (do_swap_account
)
5595 __mem_cgroup_threshold(memcg
, true);
5597 memcg
= parent_mem_cgroup(memcg
);
5601 static int compare_thresholds(const void *a
, const void *b
)
5603 const struct mem_cgroup_threshold
*_a
= a
;
5604 const struct mem_cgroup_threshold
*_b
= b
;
5606 return _a
->threshold
- _b
->threshold
;
5609 static int mem_cgroup_oom_notify_cb(struct mem_cgroup
*memcg
)
5611 struct mem_cgroup_eventfd_list
*ev
;
5613 list_for_each_entry(ev
, &memcg
->oom_notify
, list
)
5614 eventfd_signal(ev
->eventfd
, 1);
5618 static void mem_cgroup_oom_notify(struct mem_cgroup
*memcg
)
5620 struct mem_cgroup
*iter
;
5622 for_each_mem_cgroup_tree(iter
, memcg
)
5623 mem_cgroup_oom_notify_cb(iter
);
5626 static int mem_cgroup_usage_register_event(struct cgroup
*cgrp
,
5627 struct cftype
*cft
, struct eventfd_ctx
*eventfd
, const char *args
)
5629 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cgrp
);
5630 struct mem_cgroup_thresholds
*thresholds
;
5631 struct mem_cgroup_threshold_ary
*new;
5632 enum res_type type
= MEMFILE_TYPE(cft
->private);
5633 u64 threshold
, usage
;
5636 ret
= res_counter_memparse_write_strategy(args
, &threshold
);
5640 mutex_lock(&memcg
->thresholds_lock
);
5643 thresholds
= &memcg
->thresholds
;
5644 else if (type
== _MEMSWAP
)
5645 thresholds
= &memcg
->memsw_thresholds
;
5649 usage
= mem_cgroup_usage(memcg
, type
== _MEMSWAP
);
5651 /* Check if a threshold crossed before adding a new one */
5652 if (thresholds
->primary
)
5653 __mem_cgroup_threshold(memcg
, type
== _MEMSWAP
);
5655 size
= thresholds
->primary
? thresholds
->primary
->size
+ 1 : 1;
5657 /* Allocate memory for new array of thresholds */
5658 new = kmalloc(sizeof(*new) + size
* sizeof(struct mem_cgroup_threshold
),
5666 /* Copy thresholds (if any) to new array */
5667 if (thresholds
->primary
) {
5668 memcpy(new->entries
, thresholds
->primary
->entries
, (size
- 1) *
5669 sizeof(struct mem_cgroup_threshold
));
5672 /* Add new threshold */
5673 new->entries
[size
- 1].eventfd
= eventfd
;
5674 new->entries
[size
- 1].threshold
= threshold
;
5676 /* Sort thresholds. Registering of new threshold isn't time-critical */
5677 sort(new->entries
, size
, sizeof(struct mem_cgroup_threshold
),
5678 compare_thresholds
, NULL
);
5680 /* Find current threshold */
5681 new->current_threshold
= -1;
5682 for (i
= 0; i
< size
; i
++) {
5683 if (new->entries
[i
].threshold
<= usage
) {
5685 * new->current_threshold will not be used until
5686 * rcu_assign_pointer(), so it's safe to increment
5689 ++new->current_threshold
;
5694 /* Free old spare buffer and save old primary buffer as spare */
5695 kfree(thresholds
->spare
);
5696 thresholds
->spare
= thresholds
->primary
;
5698 rcu_assign_pointer(thresholds
->primary
, new);
5700 /* To be sure that nobody uses thresholds */
5704 mutex_unlock(&memcg
->thresholds_lock
);
5709 static void mem_cgroup_usage_unregister_event(struct cgroup
*cgrp
,
5710 struct cftype
*cft
, struct eventfd_ctx
*eventfd
)
5712 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cgrp
);
5713 struct mem_cgroup_thresholds
*thresholds
;
5714 struct mem_cgroup_threshold_ary
*new;
5715 enum res_type type
= MEMFILE_TYPE(cft
->private);
5719 mutex_lock(&memcg
->thresholds_lock
);
5721 thresholds
= &memcg
->thresholds
;
5722 else if (type
== _MEMSWAP
)
5723 thresholds
= &memcg
->memsw_thresholds
;
5727 if (!thresholds
->primary
)
5730 usage
= mem_cgroup_usage(memcg
, type
== _MEMSWAP
);
5732 /* Check if a threshold crossed before removing */
5733 __mem_cgroup_threshold(memcg
, type
== _MEMSWAP
);
5735 /* Calculate new number of threshold */
5737 for (i
= 0; i
< thresholds
->primary
->size
; i
++) {
5738 if (thresholds
->primary
->entries
[i
].eventfd
!= eventfd
)
5742 new = thresholds
->spare
;
5744 /* Set thresholds array to NULL if we don't have thresholds */
5753 /* Copy thresholds and find current threshold */
5754 new->current_threshold
= -1;
5755 for (i
= 0, j
= 0; i
< thresholds
->primary
->size
; i
++) {
5756 if (thresholds
->primary
->entries
[i
].eventfd
== eventfd
)
5759 new->entries
[j
] = thresholds
->primary
->entries
[i
];
5760 if (new->entries
[j
].threshold
<= usage
) {
5762 * new->current_threshold will not be used
5763 * until rcu_assign_pointer(), so it's safe to increment
5766 ++new->current_threshold
;
5772 /* Swap primary and spare array */
5773 thresholds
->spare
= thresholds
->primary
;
5774 /* If all events are unregistered, free the spare array */
5776 kfree(thresholds
->spare
);
5777 thresholds
->spare
= NULL
;
5780 rcu_assign_pointer(thresholds
->primary
, new);
5782 /* To be sure that nobody uses thresholds */
5785 mutex_unlock(&memcg
->thresholds_lock
);
5788 static int mem_cgroup_oom_register_event(struct cgroup
*cgrp
,
5789 struct cftype
*cft
, struct eventfd_ctx
*eventfd
, const char *args
)
5791 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cgrp
);
5792 struct mem_cgroup_eventfd_list
*event
;
5793 enum res_type type
= MEMFILE_TYPE(cft
->private);
5795 BUG_ON(type
!= _OOM_TYPE
);
5796 event
= kmalloc(sizeof(*event
), GFP_KERNEL
);
5800 spin_lock(&memcg_oom_lock
);
5802 event
->eventfd
= eventfd
;
5803 list_add(&event
->list
, &memcg
->oom_notify
);
5805 /* already in OOM ? */
5806 if (atomic_read(&memcg
->under_oom
))
5807 eventfd_signal(eventfd
, 1);
5808 spin_unlock(&memcg_oom_lock
);
5813 static void mem_cgroup_oom_unregister_event(struct cgroup
*cgrp
,
5814 struct cftype
*cft
, struct eventfd_ctx
*eventfd
)
5816 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cgrp
);
5817 struct mem_cgroup_eventfd_list
*ev
, *tmp
;
5818 enum res_type type
= MEMFILE_TYPE(cft
->private);
5820 BUG_ON(type
!= _OOM_TYPE
);
5822 spin_lock(&memcg_oom_lock
);
5824 list_for_each_entry_safe(ev
, tmp
, &memcg
->oom_notify
, list
) {
5825 if (ev
->eventfd
== eventfd
) {
5826 list_del(&ev
->list
);
5831 spin_unlock(&memcg_oom_lock
);
5834 static int mem_cgroup_oom_control_read(struct cgroup
*cgrp
,
5835 struct cftype
*cft
, struct cgroup_map_cb
*cb
)
5837 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cgrp
);
5839 cb
->fill(cb
, "oom_kill_disable", memcg
->oom_kill_disable
);
5841 if (atomic_read(&memcg
->under_oom
))
5842 cb
->fill(cb
, "under_oom", 1);
5844 cb
->fill(cb
, "under_oom", 0);
5848 static int mem_cgroup_oom_control_write(struct cgroup
*cgrp
,
5849 struct cftype
*cft
, u64 val
)
5851 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cgrp
);
5852 struct mem_cgroup
*parent
;
5854 /* cannot set to root cgroup and only 0 and 1 are allowed */
5855 if (!cgrp
->parent
|| !((val
== 0) || (val
== 1)))
5858 parent
= mem_cgroup_from_cont(cgrp
->parent
);
5860 mutex_lock(&memcg_create_mutex
);
5861 /* oom-kill-disable is a flag for subhierarchy. */
5862 if ((parent
->use_hierarchy
) || memcg_has_children(memcg
)) {
5863 mutex_unlock(&memcg_create_mutex
);
5866 memcg
->oom_kill_disable
= val
;
5868 memcg_oom_recover(memcg
);
5869 mutex_unlock(&memcg_create_mutex
);
5873 #ifdef CONFIG_MEMCG_KMEM
5874 static int memcg_init_kmem(struct mem_cgroup
*memcg
, struct cgroup_subsys
*ss
)
5878 memcg
->kmemcg_id
= -1;
5879 ret
= memcg_propagate_kmem(memcg
);
5883 return mem_cgroup_sockets_init(memcg
, ss
);
5886 static void kmem_cgroup_destroy(struct mem_cgroup
*memcg
)
5888 mem_cgroup_sockets_destroy(memcg
);
5890 memcg_kmem_mark_dead(memcg
);
5892 if (res_counter_read_u64(&memcg
->kmem
, RES_USAGE
) != 0)
5896 * Charges already down to 0, undo mem_cgroup_get() done in the charge
5897 * path here, being careful not to race with memcg_uncharge_kmem: it is
5898 * possible that the charges went down to 0 between mark_dead and the
5899 * res_counter read, so in that case, we don't need the put
5901 if (memcg_kmem_test_and_clear_dead(memcg
))
5902 mem_cgroup_put(memcg
);
5905 static int memcg_init_kmem(struct mem_cgroup
*memcg
, struct cgroup_subsys
*ss
)
5910 static void kmem_cgroup_destroy(struct mem_cgroup
*memcg
)
5915 static struct cftype mem_cgroup_files
[] = {
5917 .name
= "usage_in_bytes",
5918 .private = MEMFILE_PRIVATE(_MEM
, RES_USAGE
),
5919 .read
= mem_cgroup_read
,
5920 .register_event
= mem_cgroup_usage_register_event
,
5921 .unregister_event
= mem_cgroup_usage_unregister_event
,
5924 .name
= "max_usage_in_bytes",
5925 .private = MEMFILE_PRIVATE(_MEM
, RES_MAX_USAGE
),
5926 .trigger
= mem_cgroup_reset
,
5927 .read
= mem_cgroup_read
,
5930 .name
= "limit_in_bytes",
5931 .private = MEMFILE_PRIVATE(_MEM
, RES_LIMIT
),
5932 .write_string
= mem_cgroup_write
,
5933 .read
= mem_cgroup_read
,
5936 .name
= "soft_limit_in_bytes",
5937 .private = MEMFILE_PRIVATE(_MEM
, RES_SOFT_LIMIT
),
5938 .write_string
= mem_cgroup_write
,
5939 .read
= mem_cgroup_read
,
5943 .private = MEMFILE_PRIVATE(_MEM
, RES_FAILCNT
),
5944 .trigger
= mem_cgroup_reset
,
5945 .read
= mem_cgroup_read
,
5949 .read_seq_string
= memcg_stat_show
,
5952 .name
= "force_empty",
5953 .trigger
= mem_cgroup_force_empty_write
,
5956 .name
= "use_hierarchy",
5957 .flags
= CFTYPE_INSANE
,
5958 .write_u64
= mem_cgroup_hierarchy_write
,
5959 .read_u64
= mem_cgroup_hierarchy_read
,
5962 .name
= "swappiness",
5963 .read_u64
= mem_cgroup_swappiness_read
,
5964 .write_u64
= mem_cgroup_swappiness_write
,
5967 .name
= "move_charge_at_immigrate",
5968 .read_u64
= mem_cgroup_move_charge_read
,
5969 .write_u64
= mem_cgroup_move_charge_write
,
5972 .name
= "oom_control",
5973 .read_map
= mem_cgroup_oom_control_read
,
5974 .write_u64
= mem_cgroup_oom_control_write
,
5975 .register_event
= mem_cgroup_oom_register_event
,
5976 .unregister_event
= mem_cgroup_oom_unregister_event
,
5977 .private = MEMFILE_PRIVATE(_OOM_TYPE
, OOM_CONTROL
),
5980 .name
= "pressure_level",
5981 .register_event
= vmpressure_register_event
,
5982 .unregister_event
= vmpressure_unregister_event
,
5986 .name
= "numa_stat",
5987 .read_seq_string
= memcg_numa_stat_show
,
5990 #ifdef CONFIG_MEMCG_KMEM
5992 .name
= "kmem.limit_in_bytes",
5993 .private = MEMFILE_PRIVATE(_KMEM
, RES_LIMIT
),
5994 .write_string
= mem_cgroup_write
,
5995 .read
= mem_cgroup_read
,
5998 .name
= "kmem.usage_in_bytes",
5999 .private = MEMFILE_PRIVATE(_KMEM
, RES_USAGE
),
6000 .read
= mem_cgroup_read
,
6003 .name
= "kmem.failcnt",
6004 .private = MEMFILE_PRIVATE(_KMEM
, RES_FAILCNT
),
6005 .trigger
= mem_cgroup_reset
,
6006 .read
= mem_cgroup_read
,
6009 .name
= "kmem.max_usage_in_bytes",
6010 .private = MEMFILE_PRIVATE(_KMEM
, RES_MAX_USAGE
),
6011 .trigger
= mem_cgroup_reset
,
6012 .read
= mem_cgroup_read
,
6014 #ifdef CONFIG_SLABINFO
6016 .name
= "kmem.slabinfo",
6017 .read_seq_string
= mem_cgroup_slabinfo_read
,
6021 { }, /* terminate */
6024 #ifdef CONFIG_MEMCG_SWAP
6025 static struct cftype memsw_cgroup_files
[] = {
6027 .name
= "memsw.usage_in_bytes",
6028 .private = MEMFILE_PRIVATE(_MEMSWAP
, RES_USAGE
),
6029 .read
= mem_cgroup_read
,
6030 .register_event
= mem_cgroup_usage_register_event
,
6031 .unregister_event
= mem_cgroup_usage_unregister_event
,
6034 .name
= "memsw.max_usage_in_bytes",
6035 .private = MEMFILE_PRIVATE(_MEMSWAP
, RES_MAX_USAGE
),
6036 .trigger
= mem_cgroup_reset
,
6037 .read
= mem_cgroup_read
,
6040 .name
= "memsw.limit_in_bytes",
6041 .private = MEMFILE_PRIVATE(_MEMSWAP
, RES_LIMIT
),
6042 .write_string
= mem_cgroup_write
,
6043 .read
= mem_cgroup_read
,
6046 .name
= "memsw.failcnt",
6047 .private = MEMFILE_PRIVATE(_MEMSWAP
, RES_FAILCNT
),
6048 .trigger
= mem_cgroup_reset
,
6049 .read
= mem_cgroup_read
,
6051 { }, /* terminate */
6054 static int alloc_mem_cgroup_per_zone_info(struct mem_cgroup
*memcg
, int node
)
6056 struct mem_cgroup_per_node
*pn
;
6057 struct mem_cgroup_per_zone
*mz
;
6058 int zone
, tmp
= node
;
6060 * This routine is called against possible nodes.
6061 * But it's BUG to call kmalloc() against offline node.
6063 * TODO: this routine can waste much memory for nodes which will
6064 * never be onlined. It's better to use memory hotplug callback
6067 if (!node_state(node
, N_NORMAL_MEMORY
))
6069 pn
= kzalloc_node(sizeof(*pn
), GFP_KERNEL
, tmp
);
6073 for (zone
= 0; zone
< MAX_NR_ZONES
; zone
++) {
6074 mz
= &pn
->zoneinfo
[zone
];
6075 lruvec_init(&mz
->lruvec
);
6076 mz
->usage_in_excess
= 0;
6077 mz
->on_tree
= false;
6080 memcg
->nodeinfo
[node
] = pn
;
6084 static void free_mem_cgroup_per_zone_info(struct mem_cgroup
*memcg
, int node
)
6086 kfree(memcg
->nodeinfo
[node
]);
6089 static struct mem_cgroup
*mem_cgroup_alloc(void)
6091 struct mem_cgroup
*memcg
;
6092 size_t size
= memcg_size();
6094 /* Can be very big if nr_node_ids is very big */
6095 if (size
< PAGE_SIZE
)
6096 memcg
= kzalloc(size
, GFP_KERNEL
);
6098 memcg
= vzalloc(size
);
6103 memcg
->stat
= alloc_percpu(struct mem_cgroup_stat_cpu
);
6106 spin_lock_init(&memcg
->pcp_counter_lock
);
6110 if (size
< PAGE_SIZE
)
6118 * At destroying mem_cgroup, references from swap_cgroup can remain.
6119 * (scanning all at force_empty is too costly...)
6121 * Instead of clearing all references at force_empty, we remember
6122 * the number of reference from swap_cgroup and free mem_cgroup when
6123 * it goes down to 0.
6125 * Removal of cgroup itself succeeds regardless of refs from swap.
6128 static void __mem_cgroup_free(struct mem_cgroup
*memcg
)
6131 size_t size
= memcg_size();
6133 mem_cgroup_remove_from_trees(memcg
);
6134 free_css_id(&mem_cgroup_subsys
, &memcg
->css
);
6137 free_mem_cgroup_per_zone_info(memcg
, node
);
6139 free_percpu(memcg
->stat
);
6142 * We need to make sure that (at least for now), the jump label
6143 * destruction code runs outside of the cgroup lock. This is because
6144 * get_online_cpus(), which is called from the static_branch update,
6145 * can't be called inside the cgroup_lock. cpusets are the ones
6146 * enforcing this dependency, so if they ever change, we might as well.
6148 * schedule_work() will guarantee this happens. Be careful if you need
6149 * to move this code around, and make sure it is outside
6152 disarm_static_keys(memcg
);
6153 if (size
< PAGE_SIZE
)
6161 * Helpers for freeing a kmalloc()ed/vzalloc()ed mem_cgroup by RCU,
6162 * but in process context. The work_freeing structure is overlaid
6163 * on the rcu_freeing structure, which itself is overlaid on memsw.
6165 static void free_work(struct work_struct
*work
)
6167 struct mem_cgroup
*memcg
;
6169 memcg
= container_of(work
, struct mem_cgroup
, work_freeing
);
6170 __mem_cgroup_free(memcg
);
6173 static void free_rcu(struct rcu_head
*rcu_head
)
6175 struct mem_cgroup
*memcg
;
6177 memcg
= container_of(rcu_head
, struct mem_cgroup
, rcu_freeing
);
6178 INIT_WORK(&memcg
->work_freeing
, free_work
);
6179 schedule_work(&memcg
->work_freeing
);
6182 static void mem_cgroup_get(struct mem_cgroup
*memcg
)
6184 atomic_inc(&memcg
->refcnt
);
6187 static void __mem_cgroup_put(struct mem_cgroup
*memcg
, int count
)
6189 if (atomic_sub_and_test(count
, &memcg
->refcnt
)) {
6190 struct mem_cgroup
*parent
= parent_mem_cgroup(memcg
);
6191 call_rcu(&memcg
->rcu_freeing
, free_rcu
);
6193 mem_cgroup_put(parent
);
6197 static void mem_cgroup_put(struct mem_cgroup
*memcg
)
6199 __mem_cgroup_put(memcg
, 1);
6203 * Returns the parent mem_cgroup in memcgroup hierarchy with hierarchy enabled.
6205 struct mem_cgroup
*parent_mem_cgroup(struct mem_cgroup
*memcg
)
6207 if (!memcg
->res
.parent
)
6209 return mem_cgroup_from_res_counter(memcg
->res
.parent
, res
);
6211 EXPORT_SYMBOL(parent_mem_cgroup
);
6213 static void __init
mem_cgroup_soft_limit_tree_init(void)
6215 struct mem_cgroup_tree_per_node
*rtpn
;
6216 struct mem_cgroup_tree_per_zone
*rtpz
;
6217 int tmp
, node
, zone
;
6219 for_each_node(node
) {
6221 if (!node_state(node
, N_NORMAL_MEMORY
))
6223 rtpn
= kzalloc_node(sizeof(*rtpn
), GFP_KERNEL
, tmp
);
6226 soft_limit_tree
.rb_tree_per_node
[node
] = rtpn
;
6228 for (zone
= 0; zone
< MAX_NR_ZONES
; zone
++) {
6229 rtpz
= &rtpn
->rb_tree_per_zone
[zone
];
6230 rtpz
->rb_root
= RB_ROOT
;
6231 spin_lock_init(&rtpz
->lock
);
6236 static struct cgroup_subsys_state
* __ref
6237 mem_cgroup_css_alloc(struct cgroup
*cont
)
6239 struct mem_cgroup
*memcg
;
6240 long error
= -ENOMEM
;
6243 memcg
= mem_cgroup_alloc();
6245 return ERR_PTR(error
);
6248 if (alloc_mem_cgroup_per_zone_info(memcg
, node
))
6252 if (cont
->parent
== NULL
) {
6253 root_mem_cgroup
= memcg
;
6254 res_counter_init(&memcg
->res
, NULL
);
6255 res_counter_init(&memcg
->memsw
, NULL
);
6256 res_counter_init(&memcg
->kmem
, NULL
);
6259 memcg
->last_scanned_node
= MAX_NUMNODES
;
6260 INIT_LIST_HEAD(&memcg
->oom_notify
);
6261 atomic_set(&memcg
->refcnt
, 1);
6262 memcg
->move_charge_at_immigrate
= 0;
6263 mutex_init(&memcg
->thresholds_lock
);
6264 spin_lock_init(&memcg
->move_lock
);
6265 vmpressure_init(&memcg
->vmpressure
);
6270 __mem_cgroup_free(memcg
);
6271 return ERR_PTR(error
);
6275 mem_cgroup_css_online(struct cgroup
*cont
)
6277 struct mem_cgroup
*memcg
, *parent
;
6283 mutex_lock(&memcg_create_mutex
);
6284 memcg
= mem_cgroup_from_cont(cont
);
6285 parent
= mem_cgroup_from_cont(cont
->parent
);
6287 memcg
->use_hierarchy
= parent
->use_hierarchy
;
6288 memcg
->oom_kill_disable
= parent
->oom_kill_disable
;
6289 memcg
->swappiness
= mem_cgroup_swappiness(parent
);
6291 if (parent
->use_hierarchy
) {
6292 res_counter_init(&memcg
->res
, &parent
->res
);
6293 res_counter_init(&memcg
->memsw
, &parent
->memsw
);
6294 res_counter_init(&memcg
->kmem
, &parent
->kmem
);
6297 * We increment refcnt of the parent to ensure that we can
6298 * safely access it on res_counter_charge/uncharge.
6299 * This refcnt will be decremented when freeing this
6300 * mem_cgroup(see mem_cgroup_put).
6302 mem_cgroup_get(parent
);
6304 res_counter_init(&memcg
->res
, NULL
);
6305 res_counter_init(&memcg
->memsw
, NULL
);
6306 res_counter_init(&memcg
->kmem
, NULL
);
6308 * Deeper hierachy with use_hierarchy == false doesn't make
6309 * much sense so let cgroup subsystem know about this
6310 * unfortunate state in our controller.
6312 if (parent
!= root_mem_cgroup
)
6313 mem_cgroup_subsys
.broken_hierarchy
= true;
6316 error
= memcg_init_kmem(memcg
, &mem_cgroup_subsys
);
6317 mutex_unlock(&memcg_create_mutex
);
6320 * We call put now because our (and parent's) refcnts
6321 * are already in place. mem_cgroup_put() will internally
6322 * call __mem_cgroup_free, so return directly
6324 mem_cgroup_put(memcg
);
6325 if (parent
->use_hierarchy
)
6326 mem_cgroup_put(parent
);
6332 * Announce all parents that a group from their hierarchy is gone.
6334 static void mem_cgroup_invalidate_reclaim_iterators(struct mem_cgroup
*memcg
)
6336 struct mem_cgroup
*parent
= memcg
;
6338 while ((parent
= parent_mem_cgroup(parent
)))
6339 mem_cgroup_iter_invalidate(parent
);
6342 * if the root memcg is not hierarchical we have to check it
6345 if (!root_mem_cgroup
->use_hierarchy
)
6346 mem_cgroup_iter_invalidate(root_mem_cgroup
);
6349 static void mem_cgroup_css_offline(struct cgroup
*cont
)
6351 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cont
);
6353 mem_cgroup_invalidate_reclaim_iterators(memcg
);
6354 mem_cgroup_reparent_charges(memcg
);
6355 mem_cgroup_destroy_all_caches(memcg
);
6358 static void mem_cgroup_css_free(struct cgroup
*cont
)
6360 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cont
);
6362 kmem_cgroup_destroy(memcg
);
6364 mem_cgroup_put(memcg
);
6368 /* Handlers for move charge at task migration. */
6369 #define PRECHARGE_COUNT_AT_ONCE 256
6370 static int mem_cgroup_do_precharge(unsigned long count
)
6373 int batch_count
= PRECHARGE_COUNT_AT_ONCE
;
6374 struct mem_cgroup
*memcg
= mc
.to
;
6376 if (mem_cgroup_is_root(memcg
)) {
6377 mc
.precharge
+= count
;
6378 /* we don't need css_get for root */
6381 /* try to charge at once */
6383 struct res_counter
*dummy
;
6385 * "memcg" cannot be under rmdir() because we've already checked
6386 * by cgroup_lock_live_cgroup() that it is not removed and we
6387 * are still under the same cgroup_mutex. So we can postpone
6390 if (res_counter_charge(&memcg
->res
, PAGE_SIZE
* count
, &dummy
))
6392 if (do_swap_account
&& res_counter_charge(&memcg
->memsw
,
6393 PAGE_SIZE
* count
, &dummy
)) {
6394 res_counter_uncharge(&memcg
->res
, PAGE_SIZE
* count
);
6397 mc
.precharge
+= count
;
6401 /* fall back to one by one charge */
6403 if (signal_pending(current
)) {
6407 if (!batch_count
--) {
6408 batch_count
= PRECHARGE_COUNT_AT_ONCE
;
6411 ret
= __mem_cgroup_try_charge(NULL
,
6412 GFP_KERNEL
, 1, &memcg
, false);
6414 /* mem_cgroup_clear_mc() will do uncharge later */
6422 * get_mctgt_type - get target type of moving charge
6423 * @vma: the vma the pte to be checked belongs
6424 * @addr: the address corresponding to the pte to be checked
6425 * @ptent: the pte to be checked
6426 * @target: the pointer the target page or swap ent will be stored(can be NULL)
6429 * 0(MC_TARGET_NONE): if the pte is not a target for move charge.
6430 * 1(MC_TARGET_PAGE): if the page corresponding to this pte is a target for
6431 * move charge. if @target is not NULL, the page is stored in target->page
6432 * with extra refcnt got(Callers should handle it).
6433 * 2(MC_TARGET_SWAP): if the swap entry corresponding to this pte is a
6434 * target for charge migration. if @target is not NULL, the entry is stored
6437 * Called with pte lock held.
6444 enum mc_target_type
{
6450 static struct page
*mc_handle_present_pte(struct vm_area_struct
*vma
,
6451 unsigned long addr
, pte_t ptent
)
6453 struct page
*page
= vm_normal_page(vma
, addr
, ptent
);
6455 if (!page
|| !page_mapped(page
))
6457 if (PageAnon(page
)) {
6458 /* we don't move shared anon */
6461 } else if (!move_file())
6462 /* we ignore mapcount for file pages */
6464 if (!get_page_unless_zero(page
))
6471 static struct page
*mc_handle_swap_pte(struct vm_area_struct
*vma
,
6472 unsigned long addr
, pte_t ptent
, swp_entry_t
*entry
)
6474 struct page
*page
= NULL
;
6475 swp_entry_t ent
= pte_to_swp_entry(ptent
);
6477 if (!move_anon() || non_swap_entry(ent
))
6480 * Because lookup_swap_cache() updates some statistics counter,
6481 * we call find_get_page() with swapper_space directly.
6483 page
= find_get_page(swap_address_space(ent
), ent
.val
);
6484 if (do_swap_account
)
6485 entry
->val
= ent
.val
;
6490 static struct page
*mc_handle_swap_pte(struct vm_area_struct
*vma
,
6491 unsigned long addr
, pte_t ptent
, swp_entry_t
*entry
)
6497 static struct page
*mc_handle_file_pte(struct vm_area_struct
*vma
,
6498 unsigned long addr
, pte_t ptent
, swp_entry_t
*entry
)
6500 struct page
*page
= NULL
;
6501 struct address_space
*mapping
;
6504 if (!vma
->vm_file
) /* anonymous vma */
6509 mapping
= vma
->vm_file
->f_mapping
;
6510 if (pte_none(ptent
))
6511 pgoff
= linear_page_index(vma
, addr
);
6512 else /* pte_file(ptent) is true */
6513 pgoff
= pte_to_pgoff(ptent
);
6515 /* page is moved even if it's not RSS of this task(page-faulted). */
6516 page
= find_get_page(mapping
, pgoff
);
6519 /* shmem/tmpfs may report page out on swap: account for that too. */
6520 if (radix_tree_exceptional_entry(page
)) {
6521 swp_entry_t swap
= radix_to_swp_entry(page
);
6522 if (do_swap_account
)
6524 page
= find_get_page(swap_address_space(swap
), swap
.val
);
6530 static enum mc_target_type
get_mctgt_type(struct vm_area_struct
*vma
,
6531 unsigned long addr
, pte_t ptent
, union mc_target
*target
)
6533 struct page
*page
= NULL
;
6534 struct page_cgroup
*pc
;
6535 enum mc_target_type ret
= MC_TARGET_NONE
;
6536 swp_entry_t ent
= { .val
= 0 };
6538 if (pte_present(ptent
))
6539 page
= mc_handle_present_pte(vma
, addr
, ptent
);
6540 else if (is_swap_pte(ptent
))
6541 page
= mc_handle_swap_pte(vma
, addr
, ptent
, &ent
);
6542 else if (pte_none(ptent
) || pte_file(ptent
))
6543 page
= mc_handle_file_pte(vma
, addr
, ptent
, &ent
);
6545 if (!page
&& !ent
.val
)
6548 pc
= lookup_page_cgroup(page
);
6550 * Do only loose check w/o page_cgroup lock.
6551 * mem_cgroup_move_account() checks the pc is valid or not under
6554 if (PageCgroupUsed(pc
) && pc
->mem_cgroup
== mc
.from
) {
6555 ret
= MC_TARGET_PAGE
;
6557 target
->page
= page
;
6559 if (!ret
|| !target
)
6562 /* There is a swap entry and a page doesn't exist or isn't charged */
6563 if (ent
.val
&& !ret
&&
6564 css_id(&mc
.from
->css
) == lookup_swap_cgroup_id(ent
)) {
6565 ret
= MC_TARGET_SWAP
;
6572 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
6574 * We don't consider swapping or file mapped pages because THP does not
6575 * support them for now.
6576 * Caller should make sure that pmd_trans_huge(pmd) is true.
6578 static enum mc_target_type
get_mctgt_type_thp(struct vm_area_struct
*vma
,
6579 unsigned long addr
, pmd_t pmd
, union mc_target
*target
)
6581 struct page
*page
= NULL
;
6582 struct page_cgroup
*pc
;
6583 enum mc_target_type ret
= MC_TARGET_NONE
;
6585 page
= pmd_page(pmd
);
6586 VM_BUG_ON(!page
|| !PageHead(page
));
6589 pc
= lookup_page_cgroup(page
);
6590 if (PageCgroupUsed(pc
) && pc
->mem_cgroup
== mc
.from
) {
6591 ret
= MC_TARGET_PAGE
;
6594 target
->page
= page
;
6600 static inline enum mc_target_type
get_mctgt_type_thp(struct vm_area_struct
*vma
,
6601 unsigned long addr
, pmd_t pmd
, union mc_target
*target
)
6603 return MC_TARGET_NONE
;
6607 static int mem_cgroup_count_precharge_pte_range(pmd_t
*pmd
,
6608 unsigned long addr
, unsigned long end
,
6609 struct mm_walk
*walk
)
6611 struct vm_area_struct
*vma
= walk
->private;
6615 if (pmd_trans_huge_lock(pmd
, vma
) == 1) {
6616 if (get_mctgt_type_thp(vma
, addr
, *pmd
, NULL
) == MC_TARGET_PAGE
)
6617 mc
.precharge
+= HPAGE_PMD_NR
;
6618 spin_unlock(&vma
->vm_mm
->page_table_lock
);
6622 if (pmd_trans_unstable(pmd
))
6624 pte
= pte_offset_map_lock(vma
->vm_mm
, pmd
, addr
, &ptl
);
6625 for (; addr
!= end
; pte
++, addr
+= PAGE_SIZE
)
6626 if (get_mctgt_type(vma
, addr
, *pte
, NULL
))
6627 mc
.precharge
++; /* increment precharge temporarily */
6628 pte_unmap_unlock(pte
- 1, ptl
);
6634 static unsigned long mem_cgroup_count_precharge(struct mm_struct
*mm
)
6636 unsigned long precharge
;
6637 struct vm_area_struct
*vma
;
6639 down_read(&mm
->mmap_sem
);
6640 for (vma
= mm
->mmap
; vma
; vma
= vma
->vm_next
) {
6641 struct mm_walk mem_cgroup_count_precharge_walk
= {
6642 .pmd_entry
= mem_cgroup_count_precharge_pte_range
,
6646 if (is_vm_hugetlb_page(vma
))
6648 walk_page_range(vma
->vm_start
, vma
->vm_end
,
6649 &mem_cgroup_count_precharge_walk
);
6651 up_read(&mm
->mmap_sem
);
6653 precharge
= mc
.precharge
;
6659 static int mem_cgroup_precharge_mc(struct mm_struct
*mm
)
6661 unsigned long precharge
= mem_cgroup_count_precharge(mm
);
6663 VM_BUG_ON(mc
.moving_task
);
6664 mc
.moving_task
= current
;
6665 return mem_cgroup_do_precharge(precharge
);
6668 /* cancels all extra charges on mc.from and mc.to, and wakes up all waiters. */
6669 static void __mem_cgroup_clear_mc(void)
6671 struct mem_cgroup
*from
= mc
.from
;
6672 struct mem_cgroup
*to
= mc
.to
;
6674 /* we must uncharge all the leftover precharges from mc.to */
6676 __mem_cgroup_cancel_charge(mc
.to
, mc
.precharge
);
6680 * we didn't uncharge from mc.from at mem_cgroup_move_account(), so
6681 * we must uncharge here.
6683 if (mc
.moved_charge
) {
6684 __mem_cgroup_cancel_charge(mc
.from
, mc
.moved_charge
);
6685 mc
.moved_charge
= 0;
6687 /* we must fixup refcnts and charges */
6688 if (mc
.moved_swap
) {
6689 /* uncharge swap account from the old cgroup */
6690 if (!mem_cgroup_is_root(mc
.from
))
6691 res_counter_uncharge(&mc
.from
->memsw
,
6692 PAGE_SIZE
* mc
.moved_swap
);
6693 __mem_cgroup_put(mc
.from
, mc
.moved_swap
);
6695 if (!mem_cgroup_is_root(mc
.to
)) {
6697 * we charged both to->res and to->memsw, so we should
6700 res_counter_uncharge(&mc
.to
->res
,
6701 PAGE_SIZE
* mc
.moved_swap
);
6703 /* we've already done mem_cgroup_get(mc.to) */
6706 memcg_oom_recover(from
);
6707 memcg_oom_recover(to
);
6708 wake_up_all(&mc
.waitq
);
6711 static void mem_cgroup_clear_mc(void)
6713 struct mem_cgroup
*from
= mc
.from
;
6716 * we must clear moving_task before waking up waiters at the end of
6719 mc
.moving_task
= NULL
;
6720 __mem_cgroup_clear_mc();
6721 spin_lock(&mc
.lock
);
6724 spin_unlock(&mc
.lock
);
6725 mem_cgroup_end_move(from
);
6728 static int mem_cgroup_can_attach(struct cgroup
*cgroup
,
6729 struct cgroup_taskset
*tset
)
6731 struct task_struct
*p
= cgroup_taskset_first(tset
);
6733 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cgroup
);
6734 unsigned long move_charge_at_immigrate
;
6737 * We are now commited to this value whatever it is. Changes in this
6738 * tunable will only affect upcoming migrations, not the current one.
6739 * So we need to save it, and keep it going.
6741 move_charge_at_immigrate
= memcg
->move_charge_at_immigrate
;
6742 if (move_charge_at_immigrate
) {
6743 struct mm_struct
*mm
;
6744 struct mem_cgroup
*from
= mem_cgroup_from_task(p
);
6746 VM_BUG_ON(from
== memcg
);
6748 mm
= get_task_mm(p
);
6751 /* We move charges only when we move a owner of the mm */
6752 if (mm
->owner
== p
) {
6755 VM_BUG_ON(mc
.precharge
);
6756 VM_BUG_ON(mc
.moved_charge
);
6757 VM_BUG_ON(mc
.moved_swap
);
6758 mem_cgroup_start_move(from
);
6759 spin_lock(&mc
.lock
);
6762 mc
.immigrate_flags
= move_charge_at_immigrate
;
6763 spin_unlock(&mc
.lock
);
6764 /* We set mc.moving_task later */
6766 ret
= mem_cgroup_precharge_mc(mm
);
6768 mem_cgroup_clear_mc();
6775 static void mem_cgroup_cancel_attach(struct cgroup
*cgroup
,
6776 struct cgroup_taskset
*tset
)
6778 mem_cgroup_clear_mc();
6781 static int mem_cgroup_move_charge_pte_range(pmd_t
*pmd
,
6782 unsigned long addr
, unsigned long end
,
6783 struct mm_walk
*walk
)
6786 struct vm_area_struct
*vma
= walk
->private;
6789 enum mc_target_type target_type
;
6790 union mc_target target
;
6792 struct page_cgroup
*pc
;
6795 * We don't take compound_lock() here but no race with splitting thp
6797 * - if pmd_trans_huge_lock() returns 1, the relevant thp is not
6798 * under splitting, which means there's no concurrent thp split,
6799 * - if another thread runs into split_huge_page() just after we
6800 * entered this if-block, the thread must wait for page table lock
6801 * to be unlocked in __split_huge_page_splitting(), where the main
6802 * part of thp split is not executed yet.
6804 if (pmd_trans_huge_lock(pmd
, vma
) == 1) {
6805 if (mc
.precharge
< HPAGE_PMD_NR
) {
6806 spin_unlock(&vma
->vm_mm
->page_table_lock
);
6809 target_type
= get_mctgt_type_thp(vma
, addr
, *pmd
, &target
);
6810 if (target_type
== MC_TARGET_PAGE
) {
6812 if (!isolate_lru_page(page
)) {
6813 pc
= lookup_page_cgroup(page
);
6814 if (!mem_cgroup_move_account(page
, HPAGE_PMD_NR
,
6815 pc
, mc
.from
, mc
.to
)) {
6816 mc
.precharge
-= HPAGE_PMD_NR
;
6817 mc
.moved_charge
+= HPAGE_PMD_NR
;
6819 putback_lru_page(page
);
6823 spin_unlock(&vma
->vm_mm
->page_table_lock
);
6827 if (pmd_trans_unstable(pmd
))
6830 pte
= pte_offset_map_lock(vma
->vm_mm
, pmd
, addr
, &ptl
);
6831 for (; addr
!= end
; addr
+= PAGE_SIZE
) {
6832 pte_t ptent
= *(pte
++);
6838 switch (get_mctgt_type(vma
, addr
, ptent
, &target
)) {
6839 case MC_TARGET_PAGE
:
6841 if (isolate_lru_page(page
))
6843 pc
= lookup_page_cgroup(page
);
6844 if (!mem_cgroup_move_account(page
, 1, pc
,
6847 /* we uncharge from mc.from later. */
6850 putback_lru_page(page
);
6851 put
: /* get_mctgt_type() gets the page */
6854 case MC_TARGET_SWAP
:
6856 if (!mem_cgroup_move_swap_account(ent
, mc
.from
, mc
.to
)) {
6858 /* we fixup refcnts and charges later. */
6866 pte_unmap_unlock(pte
- 1, ptl
);
6871 * We have consumed all precharges we got in can_attach().
6872 * We try charge one by one, but don't do any additional
6873 * charges to mc.to if we have failed in charge once in attach()
6876 ret
= mem_cgroup_do_precharge(1);
6884 static void mem_cgroup_move_charge(struct mm_struct
*mm
)
6886 struct vm_area_struct
*vma
;
6888 lru_add_drain_all();
6890 if (unlikely(!down_read_trylock(&mm
->mmap_sem
))) {
6892 * Someone who are holding the mmap_sem might be waiting in
6893 * waitq. So we cancel all extra charges, wake up all waiters,
6894 * and retry. Because we cancel precharges, we might not be able
6895 * to move enough charges, but moving charge is a best-effort
6896 * feature anyway, so it wouldn't be a big problem.
6898 __mem_cgroup_clear_mc();
6902 for (vma
= mm
->mmap
; vma
; vma
= vma
->vm_next
) {
6904 struct mm_walk mem_cgroup_move_charge_walk
= {
6905 .pmd_entry
= mem_cgroup_move_charge_pte_range
,
6909 if (is_vm_hugetlb_page(vma
))
6911 ret
= walk_page_range(vma
->vm_start
, vma
->vm_end
,
6912 &mem_cgroup_move_charge_walk
);
6915 * means we have consumed all precharges and failed in
6916 * doing additional charge. Just abandon here.
6920 up_read(&mm
->mmap_sem
);
6923 static void mem_cgroup_move_task(struct cgroup
*cont
,
6924 struct cgroup_taskset
*tset
)
6926 struct task_struct
*p
= cgroup_taskset_first(tset
);
6927 struct mm_struct
*mm
= get_task_mm(p
);
6931 mem_cgroup_move_charge(mm
);
6935 mem_cgroup_clear_mc();
6937 #else /* !CONFIG_MMU */
6938 static int mem_cgroup_can_attach(struct cgroup
*cgroup
,
6939 struct cgroup_taskset
*tset
)
6943 static void mem_cgroup_cancel_attach(struct cgroup
*cgroup
,
6944 struct cgroup_taskset
*tset
)
6947 static void mem_cgroup_move_task(struct cgroup
*cont
,
6948 struct cgroup_taskset
*tset
)
6954 * Cgroup retains root cgroups across [un]mount cycles making it necessary
6955 * to verify sane_behavior flag on each mount attempt.
6957 static void mem_cgroup_bind(struct cgroup
*root
)
6960 * use_hierarchy is forced with sane_behavior. cgroup core
6961 * guarantees that @root doesn't have any children, so turning it
6962 * on for the root memcg is enough.
6964 if (cgroup_sane_behavior(root
))
6965 mem_cgroup_from_cont(root
)->use_hierarchy
= true;
6968 struct cgroup_subsys mem_cgroup_subsys
= {
6970 .subsys_id
= mem_cgroup_subsys_id
,
6971 .css_alloc
= mem_cgroup_css_alloc
,
6972 .css_online
= mem_cgroup_css_online
,
6973 .css_offline
= mem_cgroup_css_offline
,
6974 .css_free
= mem_cgroup_css_free
,
6975 .can_attach
= mem_cgroup_can_attach
,
6976 .cancel_attach
= mem_cgroup_cancel_attach
,
6977 .attach
= mem_cgroup_move_task
,
6978 .bind
= mem_cgroup_bind
,
6979 .base_cftypes
= mem_cgroup_files
,
6984 #ifdef CONFIG_MEMCG_SWAP
6985 static int __init
enable_swap_account(char *s
)
6987 /* consider enabled if no parameter or 1 is given */
6988 if (!strcmp(s
, "1"))
6989 really_do_swap_account
= 1;
6990 else if (!strcmp(s
, "0"))
6991 really_do_swap_account
= 0;
6994 __setup("swapaccount=", enable_swap_account
);
6996 static void __init
memsw_file_init(void)
6998 WARN_ON(cgroup_add_cftypes(&mem_cgroup_subsys
, memsw_cgroup_files
));
7001 static void __init
enable_swap_cgroup(void)
7003 if (!mem_cgroup_disabled() && really_do_swap_account
) {
7004 do_swap_account
= 1;
7010 static void __init
enable_swap_cgroup(void)
7016 * subsys_initcall() for memory controller.
7018 * Some parts like hotcpu_notifier() have to be initialized from this context
7019 * because of lock dependencies (cgroup_lock -> cpu hotplug) but basically
7020 * everything that doesn't depend on a specific mem_cgroup structure should
7021 * be initialized from here.
7023 static int __init
mem_cgroup_init(void)
7025 hotcpu_notifier(memcg_cpu_hotplug_callback
, 0);
7026 enable_swap_cgroup();
7027 mem_cgroup_soft_limit_tree_init();
7031 subsys_initcall(mem_cgroup_init
);