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/page_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/poll.h>
49 #include <linux/sort.h>
51 #include <linux/seq_file.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>
57 #include <linux/lockdep.h>
58 #include <linux/file.h>
62 #include <net/tcp_memcontrol.h>
65 #include <asm/uaccess.h>
67 #include <trace/events/vmscan.h>
69 struct cgroup_subsys memory_cgrp_subsys __read_mostly
;
70 EXPORT_SYMBOL(memory_cgrp_subsys
);
72 #define MEM_CGROUP_RECLAIM_RETRIES 5
73 static struct mem_cgroup
*root_mem_cgroup __read_mostly
;
75 #ifdef CONFIG_MEMCG_SWAP
76 /* Turned on only when memory cgroup is enabled && really_do_swap_account = 1 */
77 int do_swap_account __read_mostly
;
79 /* for remember boot option*/
80 #ifdef CONFIG_MEMCG_SWAP_ENABLED
81 static int really_do_swap_account __initdata
= 1;
83 static int really_do_swap_account __initdata
;
87 #define do_swap_account 0
91 static const char * const mem_cgroup_stat_names
[] = {
100 enum mem_cgroup_events_index
{
101 MEM_CGROUP_EVENTS_PGPGIN
, /* # of pages paged in */
102 MEM_CGROUP_EVENTS_PGPGOUT
, /* # of pages paged out */
103 MEM_CGROUP_EVENTS_PGFAULT
, /* # of page-faults */
104 MEM_CGROUP_EVENTS_PGMAJFAULT
, /* # of major page-faults */
105 MEM_CGROUP_EVENTS_NSTATS
,
108 static const char * const mem_cgroup_events_names
[] = {
115 static const char * const mem_cgroup_lru_names
[] = {
124 * Per memcg event counter is incremented at every pagein/pageout. With THP,
125 * it will be incremated by the number of pages. This counter is used for
126 * for trigger some periodic events. This is straightforward and better
127 * than using jiffies etc. to handle periodic memcg event.
129 enum mem_cgroup_events_target
{
130 MEM_CGROUP_TARGET_THRESH
,
131 MEM_CGROUP_TARGET_SOFTLIMIT
,
132 MEM_CGROUP_TARGET_NUMAINFO
,
135 #define THRESHOLDS_EVENTS_TARGET 128
136 #define SOFTLIMIT_EVENTS_TARGET 1024
137 #define NUMAINFO_EVENTS_TARGET 1024
139 struct mem_cgroup_stat_cpu
{
140 long count
[MEM_CGROUP_STAT_NSTATS
];
141 unsigned long events
[MEM_CGROUP_EVENTS_NSTATS
];
142 unsigned long nr_page_events
;
143 unsigned long targets
[MEM_CGROUP_NTARGETS
];
146 struct reclaim_iter
{
147 struct mem_cgroup
*position
;
148 /* scan generation, increased every round-trip */
149 unsigned int generation
;
153 * per-zone information in memory controller.
155 struct mem_cgroup_per_zone
{
156 struct lruvec lruvec
;
157 unsigned long lru_size
[NR_LRU_LISTS
];
159 struct reclaim_iter iter
[DEF_PRIORITY
+ 1];
161 struct rb_node tree_node
; /* RB tree node */
162 unsigned long usage_in_excess
;/* Set to the value by which */
163 /* the soft limit is exceeded*/
165 struct mem_cgroup
*memcg
; /* Back pointer, we cannot */
166 /* use container_of */
169 struct mem_cgroup_per_node
{
170 struct mem_cgroup_per_zone zoneinfo
[MAX_NR_ZONES
];
174 * Cgroups above their limits are maintained in a RB-Tree, independent of
175 * their hierarchy representation
178 struct mem_cgroup_tree_per_zone
{
179 struct rb_root rb_root
;
183 struct mem_cgroup_tree_per_node
{
184 struct mem_cgroup_tree_per_zone rb_tree_per_zone
[MAX_NR_ZONES
];
187 struct mem_cgroup_tree
{
188 struct mem_cgroup_tree_per_node
*rb_tree_per_node
[MAX_NUMNODES
];
191 static struct mem_cgroup_tree soft_limit_tree __read_mostly
;
193 struct mem_cgroup_threshold
{
194 struct eventfd_ctx
*eventfd
;
195 unsigned long threshold
;
199 struct mem_cgroup_threshold_ary
{
200 /* An array index points to threshold just below or equal to usage. */
201 int current_threshold
;
202 /* Size of entries[] */
204 /* Array of thresholds */
205 struct mem_cgroup_threshold entries
[0];
208 struct mem_cgroup_thresholds
{
209 /* Primary thresholds array */
210 struct mem_cgroup_threshold_ary
*primary
;
212 * Spare threshold array.
213 * This is needed to make mem_cgroup_unregister_event() "never fail".
214 * It must be able to store at least primary->size - 1 entries.
216 struct mem_cgroup_threshold_ary
*spare
;
220 struct mem_cgroup_eventfd_list
{
221 struct list_head list
;
222 struct eventfd_ctx
*eventfd
;
226 * cgroup_event represents events which userspace want to receive.
228 struct mem_cgroup_event
{
230 * memcg which the event belongs to.
232 struct mem_cgroup
*memcg
;
234 * eventfd to signal userspace about the event.
236 struct eventfd_ctx
*eventfd
;
238 * Each of these stored in a list by the cgroup.
240 struct list_head list
;
242 * register_event() callback will be used to add new userspace
243 * waiter for changes related to this event. Use eventfd_signal()
244 * on eventfd to send notification to userspace.
246 int (*register_event
)(struct mem_cgroup
*memcg
,
247 struct eventfd_ctx
*eventfd
, const char *args
);
249 * unregister_event() callback will be called when userspace closes
250 * the eventfd or on cgroup removing. This callback must be set,
251 * if you want provide notification functionality.
253 void (*unregister_event
)(struct mem_cgroup
*memcg
,
254 struct eventfd_ctx
*eventfd
);
256 * All fields below needed to unregister event when
257 * userspace closes eventfd.
260 wait_queue_head_t
*wqh
;
262 struct work_struct remove
;
265 static void mem_cgroup_threshold(struct mem_cgroup
*memcg
);
266 static void mem_cgroup_oom_notify(struct mem_cgroup
*memcg
);
269 * The memory controller data structure. The memory controller controls both
270 * page cache and RSS per cgroup. We would eventually like to provide
271 * statistics based on the statistics developed by Rik Van Riel for clock-pro,
272 * to help the administrator determine what knobs to tune.
274 * TODO: Add a water mark for the memory controller. Reclaim will begin when
275 * we hit the water mark. May be even add a low water mark, such that
276 * no reclaim occurs from a cgroup at it's low water mark, this is
277 * a feature that will be implemented much later in the future.
280 struct cgroup_subsys_state css
;
282 /* Accounted resources */
283 struct page_counter memory
;
284 struct page_counter memsw
;
285 struct page_counter kmem
;
287 unsigned long soft_limit
;
289 /* vmpressure notifications */
290 struct vmpressure vmpressure
;
292 /* css_online() has been completed */
296 * Should the accounting and control be hierarchical, per subtree?
299 unsigned long kmem_account_flags
; /* See KMEM_ACCOUNTED_*, below */
303 atomic_t oom_wakeups
;
306 /* OOM-Killer disable */
307 int oom_kill_disable
;
309 /* protect arrays of thresholds */
310 struct mutex thresholds_lock
;
312 /* thresholds for memory usage. RCU-protected */
313 struct mem_cgroup_thresholds thresholds
;
315 /* thresholds for mem+swap usage. RCU-protected */
316 struct mem_cgroup_thresholds memsw_thresholds
;
318 /* For oom notifier event fd */
319 struct list_head oom_notify
;
322 * Should we move charges of a task when a task is moved into this
323 * mem_cgroup ? And what type of charges should we move ?
325 unsigned long move_charge_at_immigrate
;
327 * set > 0 if pages under this cgroup are moving to other cgroup.
329 atomic_t moving_account
;
330 /* taken only while moving_account > 0 */
331 spinlock_t move_lock
;
335 struct mem_cgroup_stat_cpu __percpu
*stat
;
337 * used when a cpu is offlined or other synchronizations
338 * See mem_cgroup_read_stat().
340 struct mem_cgroup_stat_cpu nocpu_base
;
341 spinlock_t pcp_counter_lock
;
343 #if defined(CONFIG_MEMCG_KMEM) && defined(CONFIG_INET)
344 struct cg_proto tcp_mem
;
346 #if defined(CONFIG_MEMCG_KMEM)
347 /* analogous to slab_common's slab_caches list, but per-memcg;
348 * protected by memcg_slab_mutex */
349 struct list_head memcg_slab_caches
;
350 /* Index in the kmem_cache->memcg_params->memcg_caches array */
354 int last_scanned_node
;
356 nodemask_t scan_nodes
;
357 atomic_t numainfo_events
;
358 atomic_t numainfo_updating
;
361 /* List of events which userspace want to receive */
362 struct list_head event_list
;
363 spinlock_t event_list_lock
;
365 struct mem_cgroup_per_node
*nodeinfo
[0];
366 /* WARNING: nodeinfo must be the last member here */
369 /* internal only representation about the status of kmem accounting. */
371 KMEM_ACCOUNTED_ACTIVE
, /* accounted by this cgroup itself */
374 #ifdef CONFIG_MEMCG_KMEM
375 static inline void memcg_kmem_set_active(struct mem_cgroup
*memcg
)
377 set_bit(KMEM_ACCOUNTED_ACTIVE
, &memcg
->kmem_account_flags
);
380 static bool memcg_kmem_is_active(struct mem_cgroup
*memcg
)
382 return test_bit(KMEM_ACCOUNTED_ACTIVE
, &memcg
->kmem_account_flags
);
387 /* Stuffs for move charges at task migration. */
389 * Types of charges to be moved. "move_charge_at_immitgrate" and
390 * "immigrate_flags" are treated as a left-shifted bitmap of these types.
393 MOVE_CHARGE_TYPE_ANON
, /* private anonymous page and swap of it */
394 MOVE_CHARGE_TYPE_FILE
, /* file page(including tmpfs) and swap of it */
398 /* "mc" and its members are protected by cgroup_mutex */
399 static struct move_charge_struct
{
400 spinlock_t lock
; /* for from, to */
401 struct mem_cgroup
*from
;
402 struct mem_cgroup
*to
;
403 unsigned long immigrate_flags
;
404 unsigned long precharge
;
405 unsigned long moved_charge
;
406 unsigned long moved_swap
;
407 struct task_struct
*moving_task
; /* a task moving charges */
408 wait_queue_head_t waitq
; /* a waitq for other context */
410 .lock
= __SPIN_LOCK_UNLOCKED(mc
.lock
),
411 .waitq
= __WAIT_QUEUE_HEAD_INITIALIZER(mc
.waitq
),
414 static bool move_anon(void)
416 return test_bit(MOVE_CHARGE_TYPE_ANON
, &mc
.immigrate_flags
);
419 static bool move_file(void)
421 return test_bit(MOVE_CHARGE_TYPE_FILE
, &mc
.immigrate_flags
);
425 * Maximum loops in mem_cgroup_hierarchical_reclaim(), used for soft
426 * limit reclaim to prevent infinite loops, if they ever occur.
428 #define MEM_CGROUP_MAX_RECLAIM_LOOPS 100
429 #define MEM_CGROUP_MAX_SOFT_LIMIT_RECLAIM_LOOPS 2
432 MEM_CGROUP_CHARGE_TYPE_CACHE
= 0,
433 MEM_CGROUP_CHARGE_TYPE_ANON
,
434 MEM_CGROUP_CHARGE_TYPE_SWAPOUT
, /* for accounting swapcache */
435 MEM_CGROUP_CHARGE_TYPE_DROP
, /* a page was unused swap cache */
439 /* for encoding cft->private value on file */
447 #define MEMFILE_PRIVATE(x, val) ((x) << 16 | (val))
448 #define MEMFILE_TYPE(val) ((val) >> 16 & 0xffff)
449 #define MEMFILE_ATTR(val) ((val) & 0xffff)
450 /* Used for OOM nofiier */
451 #define OOM_CONTROL (0)
454 * The memcg_create_mutex will be held whenever a new cgroup is created.
455 * As a consequence, any change that needs to protect against new child cgroups
456 * appearing has to hold it as well.
458 static DEFINE_MUTEX(memcg_create_mutex
);
460 struct mem_cgroup
*mem_cgroup_from_css(struct cgroup_subsys_state
*s
)
462 return s
? container_of(s
, struct mem_cgroup
, css
) : NULL
;
465 /* Some nice accessors for the vmpressure. */
466 struct vmpressure
*memcg_to_vmpressure(struct mem_cgroup
*memcg
)
469 memcg
= root_mem_cgroup
;
470 return &memcg
->vmpressure
;
473 struct cgroup_subsys_state
*vmpressure_to_css(struct vmpressure
*vmpr
)
475 return &container_of(vmpr
, struct mem_cgroup
, vmpressure
)->css
;
478 static inline bool mem_cgroup_is_root(struct mem_cgroup
*memcg
)
480 return (memcg
== root_mem_cgroup
);
484 * We restrict the id in the range of [1, 65535], so it can fit into
487 #define MEM_CGROUP_ID_MAX USHRT_MAX
489 static inline unsigned short mem_cgroup_id(struct mem_cgroup
*memcg
)
491 return memcg
->css
.id
;
494 static inline struct mem_cgroup
*mem_cgroup_from_id(unsigned short id
)
496 struct cgroup_subsys_state
*css
;
498 css
= css_from_id(id
, &memory_cgrp_subsys
);
499 return mem_cgroup_from_css(css
);
502 /* Writing them here to avoid exposing memcg's inner layout */
503 #if defined(CONFIG_INET) && defined(CONFIG_MEMCG_KMEM)
505 void sock_update_memcg(struct sock
*sk
)
507 if (mem_cgroup_sockets_enabled
) {
508 struct mem_cgroup
*memcg
;
509 struct cg_proto
*cg_proto
;
511 BUG_ON(!sk
->sk_prot
->proto_cgroup
);
513 /* Socket cloning can throw us here with sk_cgrp already
514 * filled. It won't however, necessarily happen from
515 * process context. So the test for root memcg given
516 * the current task's memcg won't help us in this case.
518 * Respecting the original socket's memcg is a better
519 * decision in this case.
522 BUG_ON(mem_cgroup_is_root(sk
->sk_cgrp
->memcg
));
523 css_get(&sk
->sk_cgrp
->memcg
->css
);
528 memcg
= mem_cgroup_from_task(current
);
529 cg_proto
= sk
->sk_prot
->proto_cgroup(memcg
);
530 if (!mem_cgroup_is_root(memcg
) &&
531 memcg_proto_active(cg_proto
) &&
532 css_tryget_online(&memcg
->css
)) {
533 sk
->sk_cgrp
= cg_proto
;
538 EXPORT_SYMBOL(sock_update_memcg
);
540 void sock_release_memcg(struct sock
*sk
)
542 if (mem_cgroup_sockets_enabled
&& sk
->sk_cgrp
) {
543 struct mem_cgroup
*memcg
;
544 WARN_ON(!sk
->sk_cgrp
->memcg
);
545 memcg
= sk
->sk_cgrp
->memcg
;
546 css_put(&sk
->sk_cgrp
->memcg
->css
);
550 struct cg_proto
*tcp_proto_cgroup(struct mem_cgroup
*memcg
)
552 if (!memcg
|| mem_cgroup_is_root(memcg
))
555 return &memcg
->tcp_mem
;
557 EXPORT_SYMBOL(tcp_proto_cgroup
);
559 static void disarm_sock_keys(struct mem_cgroup
*memcg
)
561 if (!memcg_proto_activated(&memcg
->tcp_mem
))
563 static_key_slow_dec(&memcg_socket_limit_enabled
);
566 static void disarm_sock_keys(struct mem_cgroup
*memcg
)
571 #ifdef CONFIG_MEMCG_KMEM
573 * This will be the memcg's index in each cache's ->memcg_params->memcg_caches.
574 * The main reason for not using cgroup id for this:
575 * this works better in sparse environments, where we have a lot of memcgs,
576 * but only a few kmem-limited. Or also, if we have, for instance, 200
577 * memcgs, and none but the 200th is kmem-limited, we'd have to have a
578 * 200 entry array for that.
580 * The current size of the caches array is stored in
581 * memcg_limited_groups_array_size. It will double each time we have to
584 static DEFINE_IDA(kmem_limited_groups
);
585 int memcg_limited_groups_array_size
;
588 * MIN_SIZE is different than 1, because we would like to avoid going through
589 * the alloc/free process all the time. In a small machine, 4 kmem-limited
590 * cgroups is a reasonable guess. In the future, it could be a parameter or
591 * tunable, but that is strictly not necessary.
593 * MAX_SIZE should be as large as the number of cgrp_ids. Ideally, we could get
594 * this constant directly from cgroup, but it is understandable that this is
595 * better kept as an internal representation in cgroup.c. In any case, the
596 * cgrp_id space is not getting any smaller, and we don't have to necessarily
597 * increase ours as well if it increases.
599 #define MEMCG_CACHES_MIN_SIZE 4
600 #define MEMCG_CACHES_MAX_SIZE MEM_CGROUP_ID_MAX
603 * A lot of the calls to the cache allocation functions are expected to be
604 * inlined by the compiler. Since the calls to memcg_kmem_get_cache are
605 * conditional to this static branch, we'll have to allow modules that does
606 * kmem_cache_alloc and the such to see this symbol as well
608 struct static_key memcg_kmem_enabled_key
;
609 EXPORT_SYMBOL(memcg_kmem_enabled_key
);
611 static void memcg_free_cache_id(int id
);
613 static void disarm_kmem_keys(struct mem_cgroup
*memcg
)
615 if (memcg_kmem_is_active(memcg
)) {
616 static_key_slow_dec(&memcg_kmem_enabled_key
);
617 memcg_free_cache_id(memcg
->kmemcg_id
);
620 * This check can't live in kmem destruction function,
621 * since the charges will outlive the cgroup
623 WARN_ON(page_counter_read(&memcg
->kmem
));
626 static void disarm_kmem_keys(struct mem_cgroup
*memcg
)
629 #endif /* CONFIG_MEMCG_KMEM */
631 static void disarm_static_keys(struct mem_cgroup
*memcg
)
633 disarm_sock_keys(memcg
);
634 disarm_kmem_keys(memcg
);
637 static struct mem_cgroup_per_zone
*
638 mem_cgroup_zone_zoneinfo(struct mem_cgroup
*memcg
, struct zone
*zone
)
640 int nid
= zone_to_nid(zone
);
641 int zid
= zone_idx(zone
);
643 return &memcg
->nodeinfo
[nid
]->zoneinfo
[zid
];
646 struct cgroup_subsys_state
*mem_cgroup_css(struct mem_cgroup
*memcg
)
651 static struct mem_cgroup_per_zone
*
652 mem_cgroup_page_zoneinfo(struct mem_cgroup
*memcg
, struct page
*page
)
654 int nid
= page_to_nid(page
);
655 int zid
= page_zonenum(page
);
657 return &memcg
->nodeinfo
[nid
]->zoneinfo
[zid
];
660 static struct mem_cgroup_tree_per_zone
*
661 soft_limit_tree_node_zone(int nid
, int zid
)
663 return &soft_limit_tree
.rb_tree_per_node
[nid
]->rb_tree_per_zone
[zid
];
666 static struct mem_cgroup_tree_per_zone
*
667 soft_limit_tree_from_page(struct page
*page
)
669 int nid
= page_to_nid(page
);
670 int zid
= page_zonenum(page
);
672 return &soft_limit_tree
.rb_tree_per_node
[nid
]->rb_tree_per_zone
[zid
];
675 static void __mem_cgroup_insert_exceeded(struct mem_cgroup_per_zone
*mz
,
676 struct mem_cgroup_tree_per_zone
*mctz
,
677 unsigned long new_usage_in_excess
)
679 struct rb_node
**p
= &mctz
->rb_root
.rb_node
;
680 struct rb_node
*parent
= NULL
;
681 struct mem_cgroup_per_zone
*mz_node
;
686 mz
->usage_in_excess
= new_usage_in_excess
;
687 if (!mz
->usage_in_excess
)
691 mz_node
= rb_entry(parent
, struct mem_cgroup_per_zone
,
693 if (mz
->usage_in_excess
< mz_node
->usage_in_excess
)
696 * We can't avoid mem cgroups that are over their soft
697 * limit by the same amount
699 else if (mz
->usage_in_excess
>= mz_node
->usage_in_excess
)
702 rb_link_node(&mz
->tree_node
, parent
, p
);
703 rb_insert_color(&mz
->tree_node
, &mctz
->rb_root
);
707 static void __mem_cgroup_remove_exceeded(struct mem_cgroup_per_zone
*mz
,
708 struct mem_cgroup_tree_per_zone
*mctz
)
712 rb_erase(&mz
->tree_node
, &mctz
->rb_root
);
716 static void mem_cgroup_remove_exceeded(struct mem_cgroup_per_zone
*mz
,
717 struct mem_cgroup_tree_per_zone
*mctz
)
721 spin_lock_irqsave(&mctz
->lock
, flags
);
722 __mem_cgroup_remove_exceeded(mz
, mctz
);
723 spin_unlock_irqrestore(&mctz
->lock
, flags
);
726 static unsigned long soft_limit_excess(struct mem_cgroup
*memcg
)
728 unsigned long nr_pages
= page_counter_read(&memcg
->memory
);
729 unsigned long soft_limit
= ACCESS_ONCE(memcg
->soft_limit
);
730 unsigned long excess
= 0;
732 if (nr_pages
> soft_limit
)
733 excess
= nr_pages
- soft_limit
;
738 static void mem_cgroup_update_tree(struct mem_cgroup
*memcg
, struct page
*page
)
740 unsigned long excess
;
741 struct mem_cgroup_per_zone
*mz
;
742 struct mem_cgroup_tree_per_zone
*mctz
;
744 mctz
= soft_limit_tree_from_page(page
);
746 * Necessary to update all ancestors when hierarchy is used.
747 * because their event counter is not touched.
749 for (; memcg
; memcg
= parent_mem_cgroup(memcg
)) {
750 mz
= mem_cgroup_page_zoneinfo(memcg
, page
);
751 excess
= soft_limit_excess(memcg
);
753 * We have to update the tree if mz is on RB-tree or
754 * mem is over its softlimit.
756 if (excess
|| mz
->on_tree
) {
759 spin_lock_irqsave(&mctz
->lock
, flags
);
760 /* if on-tree, remove it */
762 __mem_cgroup_remove_exceeded(mz
, mctz
);
764 * Insert again. mz->usage_in_excess will be updated.
765 * If excess is 0, no tree ops.
767 __mem_cgroup_insert_exceeded(mz
, mctz
, excess
);
768 spin_unlock_irqrestore(&mctz
->lock
, flags
);
773 static void mem_cgroup_remove_from_trees(struct mem_cgroup
*memcg
)
775 struct mem_cgroup_tree_per_zone
*mctz
;
776 struct mem_cgroup_per_zone
*mz
;
780 for (zid
= 0; zid
< MAX_NR_ZONES
; zid
++) {
781 mz
= &memcg
->nodeinfo
[nid
]->zoneinfo
[zid
];
782 mctz
= soft_limit_tree_node_zone(nid
, zid
);
783 mem_cgroup_remove_exceeded(mz
, mctz
);
788 static struct mem_cgroup_per_zone
*
789 __mem_cgroup_largest_soft_limit_node(struct mem_cgroup_tree_per_zone
*mctz
)
791 struct rb_node
*rightmost
= NULL
;
792 struct mem_cgroup_per_zone
*mz
;
796 rightmost
= rb_last(&mctz
->rb_root
);
798 goto done
; /* Nothing to reclaim from */
800 mz
= rb_entry(rightmost
, struct mem_cgroup_per_zone
, tree_node
);
802 * Remove the node now but someone else can add it back,
803 * we will to add it back at the end of reclaim to its correct
804 * position in the tree.
806 __mem_cgroup_remove_exceeded(mz
, mctz
);
807 if (!soft_limit_excess(mz
->memcg
) ||
808 !css_tryget_online(&mz
->memcg
->css
))
814 static struct mem_cgroup_per_zone
*
815 mem_cgroup_largest_soft_limit_node(struct mem_cgroup_tree_per_zone
*mctz
)
817 struct mem_cgroup_per_zone
*mz
;
819 spin_lock_irq(&mctz
->lock
);
820 mz
= __mem_cgroup_largest_soft_limit_node(mctz
);
821 spin_unlock_irq(&mctz
->lock
);
826 * Implementation Note: reading percpu statistics for memcg.
828 * Both of vmstat[] and percpu_counter has threshold and do periodic
829 * synchronization to implement "quick" read. There are trade-off between
830 * reading cost and precision of value. Then, we may have a chance to implement
831 * a periodic synchronizion of counter in memcg's counter.
833 * But this _read() function is used for user interface now. The user accounts
834 * memory usage by memory cgroup and he _always_ requires exact value because
835 * he accounts memory. Even if we provide quick-and-fuzzy read, we always
836 * have to visit all online cpus and make sum. So, for now, unnecessary
837 * synchronization is not implemented. (just implemented for cpu hotplug)
839 * If there are kernel internal actions which can make use of some not-exact
840 * value, and reading all cpu value can be performance bottleneck in some
841 * common workload, threashold and synchonization as vmstat[] should be
844 static long mem_cgroup_read_stat(struct mem_cgroup
*memcg
,
845 enum mem_cgroup_stat_index idx
)
851 for_each_online_cpu(cpu
)
852 val
+= per_cpu(memcg
->stat
->count
[idx
], cpu
);
853 #ifdef CONFIG_HOTPLUG_CPU
854 spin_lock(&memcg
->pcp_counter_lock
);
855 val
+= memcg
->nocpu_base
.count
[idx
];
856 spin_unlock(&memcg
->pcp_counter_lock
);
862 static unsigned long mem_cgroup_read_events(struct mem_cgroup
*memcg
,
863 enum mem_cgroup_events_index idx
)
865 unsigned long val
= 0;
869 for_each_online_cpu(cpu
)
870 val
+= per_cpu(memcg
->stat
->events
[idx
], cpu
);
871 #ifdef CONFIG_HOTPLUG_CPU
872 spin_lock(&memcg
->pcp_counter_lock
);
873 val
+= memcg
->nocpu_base
.events
[idx
];
874 spin_unlock(&memcg
->pcp_counter_lock
);
880 static void mem_cgroup_charge_statistics(struct mem_cgroup
*memcg
,
885 * Here, RSS means 'mapped anon' and anon's SwapCache. Shmem/tmpfs is
886 * counted as CACHE even if it's on ANON LRU.
889 __this_cpu_add(memcg
->stat
->count
[MEM_CGROUP_STAT_RSS
],
892 __this_cpu_add(memcg
->stat
->count
[MEM_CGROUP_STAT_CACHE
],
895 if (PageTransHuge(page
))
896 __this_cpu_add(memcg
->stat
->count
[MEM_CGROUP_STAT_RSS_HUGE
],
899 /* pagein of a big page is an event. So, ignore page size */
901 __this_cpu_inc(memcg
->stat
->events
[MEM_CGROUP_EVENTS_PGPGIN
]);
903 __this_cpu_inc(memcg
->stat
->events
[MEM_CGROUP_EVENTS_PGPGOUT
]);
904 nr_pages
= -nr_pages
; /* for event */
907 __this_cpu_add(memcg
->stat
->nr_page_events
, nr_pages
);
910 unsigned long mem_cgroup_get_lru_size(struct lruvec
*lruvec
, enum lru_list lru
)
912 struct mem_cgroup_per_zone
*mz
;
914 mz
= container_of(lruvec
, struct mem_cgroup_per_zone
, lruvec
);
915 return mz
->lru_size
[lru
];
918 static unsigned long mem_cgroup_node_nr_lru_pages(struct mem_cgroup
*memcg
,
920 unsigned int lru_mask
)
922 unsigned long nr
= 0;
925 VM_BUG_ON((unsigned)nid
>= nr_node_ids
);
927 for (zid
= 0; zid
< MAX_NR_ZONES
; zid
++) {
928 struct mem_cgroup_per_zone
*mz
;
932 if (!(BIT(lru
) & lru_mask
))
934 mz
= &memcg
->nodeinfo
[nid
]->zoneinfo
[zid
];
935 nr
+= mz
->lru_size
[lru
];
941 static unsigned long mem_cgroup_nr_lru_pages(struct mem_cgroup
*memcg
,
942 unsigned int lru_mask
)
944 unsigned long nr
= 0;
947 for_each_node_state(nid
, N_MEMORY
)
948 nr
+= mem_cgroup_node_nr_lru_pages(memcg
, nid
, lru_mask
);
952 static bool mem_cgroup_event_ratelimit(struct mem_cgroup
*memcg
,
953 enum mem_cgroup_events_target target
)
955 unsigned long val
, next
;
957 val
= __this_cpu_read(memcg
->stat
->nr_page_events
);
958 next
= __this_cpu_read(memcg
->stat
->targets
[target
]);
959 /* from time_after() in jiffies.h */
960 if ((long)next
- (long)val
< 0) {
962 case MEM_CGROUP_TARGET_THRESH
:
963 next
= val
+ THRESHOLDS_EVENTS_TARGET
;
965 case MEM_CGROUP_TARGET_SOFTLIMIT
:
966 next
= val
+ SOFTLIMIT_EVENTS_TARGET
;
968 case MEM_CGROUP_TARGET_NUMAINFO
:
969 next
= val
+ NUMAINFO_EVENTS_TARGET
;
974 __this_cpu_write(memcg
->stat
->targets
[target
], next
);
981 * Check events in order.
984 static void memcg_check_events(struct mem_cgroup
*memcg
, struct page
*page
)
986 /* threshold event is triggered in finer grain than soft limit */
987 if (unlikely(mem_cgroup_event_ratelimit(memcg
,
988 MEM_CGROUP_TARGET_THRESH
))) {
990 bool do_numainfo __maybe_unused
;
992 do_softlimit
= mem_cgroup_event_ratelimit(memcg
,
993 MEM_CGROUP_TARGET_SOFTLIMIT
);
995 do_numainfo
= mem_cgroup_event_ratelimit(memcg
,
996 MEM_CGROUP_TARGET_NUMAINFO
);
998 mem_cgroup_threshold(memcg
);
999 if (unlikely(do_softlimit
))
1000 mem_cgroup_update_tree(memcg
, page
);
1001 #if MAX_NUMNODES > 1
1002 if (unlikely(do_numainfo
))
1003 atomic_inc(&memcg
->numainfo_events
);
1008 struct mem_cgroup
*mem_cgroup_from_task(struct task_struct
*p
)
1011 * mm_update_next_owner() may clear mm->owner to NULL
1012 * if it races with swapoff, page migration, etc.
1013 * So this can be called with p == NULL.
1018 return mem_cgroup_from_css(task_css(p
, memory_cgrp_id
));
1021 static struct mem_cgroup
*get_mem_cgroup_from_mm(struct mm_struct
*mm
)
1023 struct mem_cgroup
*memcg
= NULL
;
1028 * Page cache insertions can happen withou an
1029 * actual mm context, e.g. during disk probing
1030 * on boot, loopback IO, acct() writes etc.
1033 memcg
= root_mem_cgroup
;
1035 memcg
= mem_cgroup_from_task(rcu_dereference(mm
->owner
));
1036 if (unlikely(!memcg
))
1037 memcg
= root_mem_cgroup
;
1039 } while (!css_tryget_online(&memcg
->css
));
1045 * mem_cgroup_iter - iterate over memory cgroup hierarchy
1046 * @root: hierarchy root
1047 * @prev: previously returned memcg, NULL on first invocation
1048 * @reclaim: cookie for shared reclaim walks, NULL for full walks
1050 * Returns references to children of the hierarchy below @root, or
1051 * @root itself, or %NULL after a full round-trip.
1053 * Caller must pass the return value in @prev on subsequent
1054 * invocations for reference counting, or use mem_cgroup_iter_break()
1055 * to cancel a hierarchy walk before the round-trip is complete.
1057 * Reclaimers can specify a zone and a priority level in @reclaim to
1058 * divide up the memcgs in the hierarchy among all concurrent
1059 * reclaimers operating on the same zone and priority.
1061 struct mem_cgroup
*mem_cgroup_iter(struct mem_cgroup
*root
,
1062 struct mem_cgroup
*prev
,
1063 struct mem_cgroup_reclaim_cookie
*reclaim
)
1065 struct reclaim_iter
*uninitialized_var(iter
);
1066 struct cgroup_subsys_state
*css
= NULL
;
1067 struct mem_cgroup
*memcg
= NULL
;
1068 struct mem_cgroup
*pos
= NULL
;
1070 if (mem_cgroup_disabled())
1074 root
= root_mem_cgroup
;
1076 if (prev
&& !reclaim
)
1079 if (!root
->use_hierarchy
&& root
!= root_mem_cgroup
) {
1088 struct mem_cgroup_per_zone
*mz
;
1090 mz
= mem_cgroup_zone_zoneinfo(root
, reclaim
->zone
);
1091 iter
= &mz
->iter
[reclaim
->priority
];
1093 if (prev
&& reclaim
->generation
!= iter
->generation
)
1097 pos
= ACCESS_ONCE(iter
->position
);
1099 * A racing update may change the position and
1100 * put the last reference, hence css_tryget(),
1101 * or retry to see the updated position.
1103 } while (pos
&& !css_tryget(&pos
->css
));
1110 css
= css_next_descendant_pre(css
, &root
->css
);
1113 * Reclaimers share the hierarchy walk, and a
1114 * new one might jump in right at the end of
1115 * the hierarchy - make sure they see at least
1116 * one group and restart from the beginning.
1124 * Verify the css and acquire a reference. The root
1125 * is provided by the caller, so we know it's alive
1126 * and kicking, and don't take an extra reference.
1128 memcg
= mem_cgroup_from_css(css
);
1130 if (css
== &root
->css
)
1133 if (css_tryget(css
)) {
1135 * Make sure the memcg is initialized:
1136 * mem_cgroup_css_online() orders the the
1137 * initialization against setting the flag.
1139 if (smp_load_acquire(&memcg
->initialized
))
1149 if (cmpxchg(&iter
->position
, pos
, memcg
) == pos
) {
1151 css_get(&memcg
->css
);
1157 * pairs with css_tryget when dereferencing iter->position
1166 reclaim
->generation
= iter
->generation
;
1172 if (prev
&& prev
!= root
)
1173 css_put(&prev
->css
);
1179 * mem_cgroup_iter_break - abort a hierarchy walk prematurely
1180 * @root: hierarchy root
1181 * @prev: last visited hierarchy member as returned by mem_cgroup_iter()
1183 void mem_cgroup_iter_break(struct mem_cgroup
*root
,
1184 struct mem_cgroup
*prev
)
1187 root
= root_mem_cgroup
;
1188 if (prev
&& prev
!= root
)
1189 css_put(&prev
->css
);
1193 * Iteration constructs for visiting all cgroups (under a tree). If
1194 * loops are exited prematurely (break), mem_cgroup_iter_break() must
1195 * be used for reference counting.
1197 #define for_each_mem_cgroup_tree(iter, root) \
1198 for (iter = mem_cgroup_iter(root, NULL, NULL); \
1200 iter = mem_cgroup_iter(root, iter, NULL))
1202 #define for_each_mem_cgroup(iter) \
1203 for (iter = mem_cgroup_iter(NULL, NULL, NULL); \
1205 iter = mem_cgroup_iter(NULL, iter, NULL))
1207 void __mem_cgroup_count_vm_event(struct mm_struct
*mm
, enum vm_event_item idx
)
1209 struct mem_cgroup
*memcg
;
1212 memcg
= mem_cgroup_from_task(rcu_dereference(mm
->owner
));
1213 if (unlikely(!memcg
))
1218 this_cpu_inc(memcg
->stat
->events
[MEM_CGROUP_EVENTS_PGFAULT
]);
1221 this_cpu_inc(memcg
->stat
->events
[MEM_CGROUP_EVENTS_PGMAJFAULT
]);
1229 EXPORT_SYMBOL(__mem_cgroup_count_vm_event
);
1232 * mem_cgroup_zone_lruvec - get the lru list vector for a zone and memcg
1233 * @zone: zone of the wanted lruvec
1234 * @memcg: memcg of the wanted lruvec
1236 * Returns the lru list vector holding pages for the given @zone and
1237 * @mem. This can be the global zone lruvec, if the memory controller
1240 struct lruvec
*mem_cgroup_zone_lruvec(struct zone
*zone
,
1241 struct mem_cgroup
*memcg
)
1243 struct mem_cgroup_per_zone
*mz
;
1244 struct lruvec
*lruvec
;
1246 if (mem_cgroup_disabled()) {
1247 lruvec
= &zone
->lruvec
;
1251 mz
= mem_cgroup_zone_zoneinfo(memcg
, zone
);
1252 lruvec
= &mz
->lruvec
;
1255 * Since a node can be onlined after the mem_cgroup was created,
1256 * we have to be prepared to initialize lruvec->zone here;
1257 * and if offlined then reonlined, we need to reinitialize it.
1259 if (unlikely(lruvec
->zone
!= zone
))
1260 lruvec
->zone
= zone
;
1265 * mem_cgroup_page_lruvec - return lruvec for isolating/putting an LRU page
1267 * @zone: zone of the page
1269 * This function is only safe when following the LRU page isolation
1270 * and putback protocol: the LRU lock must be held, and the page must
1271 * either be PageLRU() or the caller must have isolated/allocated it.
1273 struct lruvec
*mem_cgroup_page_lruvec(struct page
*page
, struct zone
*zone
)
1275 struct mem_cgroup_per_zone
*mz
;
1276 struct mem_cgroup
*memcg
;
1277 struct page_cgroup
*pc
;
1278 struct lruvec
*lruvec
;
1280 if (mem_cgroup_disabled()) {
1281 lruvec
= &zone
->lruvec
;
1285 pc
= lookup_page_cgroup(page
);
1286 memcg
= pc
->mem_cgroup
;
1289 * Swapcache readahead pages are added to the LRU - and
1290 * possibly migrated - before they are charged. Ensure
1291 * pc->mem_cgroup is sane.
1293 if (!PageLRU(page
) && !PageCgroupUsed(pc
) && memcg
!= root_mem_cgroup
)
1294 pc
->mem_cgroup
= memcg
= root_mem_cgroup
;
1296 mz
= mem_cgroup_page_zoneinfo(memcg
, page
);
1297 lruvec
= &mz
->lruvec
;
1300 * Since a node can be onlined after the mem_cgroup was created,
1301 * we have to be prepared to initialize lruvec->zone here;
1302 * and if offlined then reonlined, we need to reinitialize it.
1304 if (unlikely(lruvec
->zone
!= zone
))
1305 lruvec
->zone
= zone
;
1310 * mem_cgroup_update_lru_size - account for adding or removing an lru page
1311 * @lruvec: mem_cgroup per zone lru vector
1312 * @lru: index of lru list the page is sitting on
1313 * @nr_pages: positive when adding or negative when removing
1315 * This function must be called when a page is added to or removed from an
1318 void mem_cgroup_update_lru_size(struct lruvec
*lruvec
, enum lru_list lru
,
1321 struct mem_cgroup_per_zone
*mz
;
1322 unsigned long *lru_size
;
1324 if (mem_cgroup_disabled())
1327 mz
= container_of(lruvec
, struct mem_cgroup_per_zone
, lruvec
);
1328 lru_size
= mz
->lru_size
+ lru
;
1329 *lru_size
+= nr_pages
;
1330 VM_BUG_ON((long)(*lru_size
) < 0);
1334 * Checks whether given mem is same or in the root_mem_cgroup's
1337 bool __mem_cgroup_same_or_subtree(const struct mem_cgroup
*root_memcg
,
1338 struct mem_cgroup
*memcg
)
1340 if (root_memcg
== memcg
)
1342 if (!root_memcg
->use_hierarchy
|| !memcg
)
1344 return cgroup_is_descendant(memcg
->css
.cgroup
, root_memcg
->css
.cgroup
);
1347 static bool mem_cgroup_same_or_subtree(const struct mem_cgroup
*root_memcg
,
1348 struct mem_cgroup
*memcg
)
1353 ret
= __mem_cgroup_same_or_subtree(root_memcg
, memcg
);
1358 bool task_in_mem_cgroup(struct task_struct
*task
,
1359 const struct mem_cgroup
*memcg
)
1361 struct mem_cgroup
*curr
= NULL
;
1362 struct task_struct
*p
;
1365 p
= find_lock_task_mm(task
);
1367 curr
= get_mem_cgroup_from_mm(p
->mm
);
1371 * All threads may have already detached their mm's, but the oom
1372 * killer still needs to detect if they have already been oom
1373 * killed to prevent needlessly killing additional tasks.
1376 curr
= mem_cgroup_from_task(task
);
1378 css_get(&curr
->css
);
1382 * We should check use_hierarchy of "memcg" not "curr". Because checking
1383 * use_hierarchy of "curr" here make this function true if hierarchy is
1384 * enabled in "curr" and "curr" is a child of "memcg" in *cgroup*
1385 * hierarchy(even if use_hierarchy is disabled in "memcg").
1387 ret
= mem_cgroup_same_or_subtree(memcg
, curr
);
1388 css_put(&curr
->css
);
1392 int mem_cgroup_inactive_anon_is_low(struct lruvec
*lruvec
)
1394 unsigned long inactive_ratio
;
1395 unsigned long inactive
;
1396 unsigned long active
;
1399 inactive
= mem_cgroup_get_lru_size(lruvec
, LRU_INACTIVE_ANON
);
1400 active
= mem_cgroup_get_lru_size(lruvec
, LRU_ACTIVE_ANON
);
1402 gb
= (inactive
+ active
) >> (30 - PAGE_SHIFT
);
1404 inactive_ratio
= int_sqrt(10 * gb
);
1408 return inactive
* inactive_ratio
< active
;
1411 #define mem_cgroup_from_counter(counter, member) \
1412 container_of(counter, struct mem_cgroup, member)
1415 * mem_cgroup_margin - calculate chargeable space of a memory cgroup
1416 * @memcg: the memory cgroup
1418 * Returns the maximum amount of memory @mem can be charged with, in
1421 static unsigned long mem_cgroup_margin(struct mem_cgroup
*memcg
)
1423 unsigned long margin
= 0;
1424 unsigned long count
;
1425 unsigned long limit
;
1427 count
= page_counter_read(&memcg
->memory
);
1428 limit
= ACCESS_ONCE(memcg
->memory
.limit
);
1430 margin
= limit
- count
;
1432 if (do_swap_account
) {
1433 count
= page_counter_read(&memcg
->memsw
);
1434 limit
= ACCESS_ONCE(memcg
->memsw
.limit
);
1436 margin
= min(margin
, limit
- count
);
1442 int mem_cgroup_swappiness(struct mem_cgroup
*memcg
)
1445 if (mem_cgroup_disabled() || !memcg
->css
.parent
)
1446 return vm_swappiness
;
1448 return memcg
->swappiness
;
1452 * memcg->moving_account is used for checking possibility that some thread is
1453 * calling move_account(). When a thread on CPU-A starts moving pages under
1454 * a memcg, other threads should check memcg->moving_account under
1455 * rcu_read_lock(), like this:
1459 * memcg->moving_account+1 if (memcg->mocing_account)
1461 * synchronize_rcu() update something.
1466 static void mem_cgroup_start_move(struct mem_cgroup
*memcg
)
1468 atomic_inc(&memcg
->moving_account
);
1472 static void mem_cgroup_end_move(struct mem_cgroup
*memcg
)
1475 * Now, mem_cgroup_clear_mc() may call this function with NULL.
1476 * We check NULL in callee rather than caller.
1479 atomic_dec(&memcg
->moving_account
);
1483 * A routine for checking "mem" is under move_account() or not.
1485 * Checking a cgroup is mc.from or mc.to or under hierarchy of
1486 * moving cgroups. This is for waiting at high-memory pressure
1489 static bool mem_cgroup_under_move(struct mem_cgroup
*memcg
)
1491 struct mem_cgroup
*from
;
1492 struct mem_cgroup
*to
;
1495 * Unlike task_move routines, we access mc.to, mc.from not under
1496 * mutual exclusion by cgroup_mutex. Here, we take spinlock instead.
1498 spin_lock(&mc
.lock
);
1504 ret
= mem_cgroup_same_or_subtree(memcg
, from
)
1505 || mem_cgroup_same_or_subtree(memcg
, to
);
1507 spin_unlock(&mc
.lock
);
1511 static bool mem_cgroup_wait_acct_move(struct mem_cgroup
*memcg
)
1513 if (mc
.moving_task
&& current
!= mc
.moving_task
) {
1514 if (mem_cgroup_under_move(memcg
)) {
1516 prepare_to_wait(&mc
.waitq
, &wait
, TASK_INTERRUPTIBLE
);
1517 /* moving charge context might have finished. */
1520 finish_wait(&mc
.waitq
, &wait
);
1528 * Take this lock when
1529 * - a code tries to modify page's memcg while it's USED.
1530 * - a code tries to modify page state accounting in a memcg.
1532 static void move_lock_mem_cgroup(struct mem_cgroup
*memcg
,
1533 unsigned long *flags
)
1535 spin_lock_irqsave(&memcg
->move_lock
, *flags
);
1538 static void move_unlock_mem_cgroup(struct mem_cgroup
*memcg
,
1539 unsigned long *flags
)
1541 spin_unlock_irqrestore(&memcg
->move_lock
, *flags
);
1544 #define K(x) ((x) << (PAGE_SHIFT-10))
1546 * mem_cgroup_print_oom_info: Print OOM information relevant to memory controller.
1547 * @memcg: The memory cgroup that went over limit
1548 * @p: Task that is going to be killed
1550 * NOTE: @memcg and @p's mem_cgroup can be different when hierarchy is
1553 void mem_cgroup_print_oom_info(struct mem_cgroup
*memcg
, struct task_struct
*p
)
1555 /* oom_info_lock ensures that parallel ooms do not interleave */
1556 static DEFINE_MUTEX(oom_info_lock
);
1557 struct mem_cgroup
*iter
;
1563 mutex_lock(&oom_info_lock
);
1566 pr_info("Task in ");
1567 pr_cont_cgroup_path(task_cgroup(p
, memory_cgrp_id
));
1568 pr_info(" killed as a result of limit of ");
1569 pr_cont_cgroup_path(memcg
->css
.cgroup
);
1574 pr_info("memory: usage %llukB, limit %llukB, failcnt %lu\n",
1575 K((u64
)page_counter_read(&memcg
->memory
)),
1576 K((u64
)memcg
->memory
.limit
), memcg
->memory
.failcnt
);
1577 pr_info("memory+swap: usage %llukB, limit %llukB, failcnt %lu\n",
1578 K((u64
)page_counter_read(&memcg
->memsw
)),
1579 K((u64
)memcg
->memsw
.limit
), memcg
->memsw
.failcnt
);
1580 pr_info("kmem: usage %llukB, limit %llukB, failcnt %lu\n",
1581 K((u64
)page_counter_read(&memcg
->kmem
)),
1582 K((u64
)memcg
->kmem
.limit
), memcg
->kmem
.failcnt
);
1584 for_each_mem_cgroup_tree(iter
, memcg
) {
1585 pr_info("Memory cgroup stats for ");
1586 pr_cont_cgroup_path(iter
->css
.cgroup
);
1589 for (i
= 0; i
< MEM_CGROUP_STAT_NSTATS
; i
++) {
1590 if (i
== MEM_CGROUP_STAT_SWAP
&& !do_swap_account
)
1592 pr_cont(" %s:%ldKB", mem_cgroup_stat_names
[i
],
1593 K(mem_cgroup_read_stat(iter
, i
)));
1596 for (i
= 0; i
< NR_LRU_LISTS
; i
++)
1597 pr_cont(" %s:%luKB", mem_cgroup_lru_names
[i
],
1598 K(mem_cgroup_nr_lru_pages(iter
, BIT(i
))));
1602 mutex_unlock(&oom_info_lock
);
1606 * This function returns the number of memcg under hierarchy tree. Returns
1607 * 1(self count) if no children.
1609 static int mem_cgroup_count_children(struct mem_cgroup
*memcg
)
1612 struct mem_cgroup
*iter
;
1614 for_each_mem_cgroup_tree(iter
, memcg
)
1620 * Return the memory (and swap, if configured) limit for a memcg.
1622 static unsigned long mem_cgroup_get_limit(struct mem_cgroup
*memcg
)
1624 unsigned long limit
;
1626 limit
= memcg
->memory
.limit
;
1627 if (mem_cgroup_swappiness(memcg
)) {
1628 unsigned long memsw_limit
;
1630 memsw_limit
= memcg
->memsw
.limit
;
1631 limit
= min(limit
+ total_swap_pages
, memsw_limit
);
1636 static void mem_cgroup_out_of_memory(struct mem_cgroup
*memcg
, gfp_t gfp_mask
,
1639 struct mem_cgroup
*iter
;
1640 unsigned long chosen_points
= 0;
1641 unsigned long totalpages
;
1642 unsigned int points
= 0;
1643 struct task_struct
*chosen
= NULL
;
1646 * If current has a pending SIGKILL or is exiting, then automatically
1647 * select it. The goal is to allow it to allocate so that it may
1648 * quickly exit and free its memory.
1650 if (fatal_signal_pending(current
) || current
->flags
& PF_EXITING
) {
1651 set_thread_flag(TIF_MEMDIE
);
1655 check_panic_on_oom(CONSTRAINT_MEMCG
, gfp_mask
, order
, NULL
);
1656 totalpages
= mem_cgroup_get_limit(memcg
) ? : 1;
1657 for_each_mem_cgroup_tree(iter
, memcg
) {
1658 struct css_task_iter it
;
1659 struct task_struct
*task
;
1661 css_task_iter_start(&iter
->css
, &it
);
1662 while ((task
= css_task_iter_next(&it
))) {
1663 switch (oom_scan_process_thread(task
, totalpages
, NULL
,
1665 case OOM_SCAN_SELECT
:
1667 put_task_struct(chosen
);
1669 chosen_points
= ULONG_MAX
;
1670 get_task_struct(chosen
);
1672 case OOM_SCAN_CONTINUE
:
1674 case OOM_SCAN_ABORT
:
1675 css_task_iter_end(&it
);
1676 mem_cgroup_iter_break(memcg
, iter
);
1678 put_task_struct(chosen
);
1683 points
= oom_badness(task
, memcg
, NULL
, totalpages
);
1684 if (!points
|| points
< chosen_points
)
1686 /* Prefer thread group leaders for display purposes */
1687 if (points
== chosen_points
&&
1688 thread_group_leader(chosen
))
1692 put_task_struct(chosen
);
1694 chosen_points
= points
;
1695 get_task_struct(chosen
);
1697 css_task_iter_end(&it
);
1702 points
= chosen_points
* 1000 / totalpages
;
1703 oom_kill_process(chosen
, gfp_mask
, order
, points
, totalpages
, memcg
,
1704 NULL
, "Memory cgroup out of memory");
1708 * test_mem_cgroup_node_reclaimable
1709 * @memcg: the target memcg
1710 * @nid: the node ID to be checked.
1711 * @noswap : specify true here if the user wants flle only information.
1713 * This function returns whether the specified memcg contains any
1714 * reclaimable pages on a node. Returns true if there are any reclaimable
1715 * pages in the node.
1717 static bool test_mem_cgroup_node_reclaimable(struct mem_cgroup
*memcg
,
1718 int nid
, bool noswap
)
1720 if (mem_cgroup_node_nr_lru_pages(memcg
, nid
, LRU_ALL_FILE
))
1722 if (noswap
|| !total_swap_pages
)
1724 if (mem_cgroup_node_nr_lru_pages(memcg
, nid
, LRU_ALL_ANON
))
1729 #if MAX_NUMNODES > 1
1732 * Always updating the nodemask is not very good - even if we have an empty
1733 * list or the wrong list here, we can start from some node and traverse all
1734 * nodes based on the zonelist. So update the list loosely once per 10 secs.
1737 static void mem_cgroup_may_update_nodemask(struct mem_cgroup
*memcg
)
1741 * numainfo_events > 0 means there was at least NUMAINFO_EVENTS_TARGET
1742 * pagein/pageout changes since the last update.
1744 if (!atomic_read(&memcg
->numainfo_events
))
1746 if (atomic_inc_return(&memcg
->numainfo_updating
) > 1)
1749 /* make a nodemask where this memcg uses memory from */
1750 memcg
->scan_nodes
= node_states
[N_MEMORY
];
1752 for_each_node_mask(nid
, node_states
[N_MEMORY
]) {
1754 if (!test_mem_cgroup_node_reclaimable(memcg
, nid
, false))
1755 node_clear(nid
, memcg
->scan_nodes
);
1758 atomic_set(&memcg
->numainfo_events
, 0);
1759 atomic_set(&memcg
->numainfo_updating
, 0);
1763 * Selecting a node where we start reclaim from. Because what we need is just
1764 * reducing usage counter, start from anywhere is O,K. Considering
1765 * memory reclaim from current node, there are pros. and cons.
1767 * Freeing memory from current node means freeing memory from a node which
1768 * we'll use or we've used. So, it may make LRU bad. And if several threads
1769 * hit limits, it will see a contention on a node. But freeing from remote
1770 * node means more costs for memory reclaim because of memory latency.
1772 * Now, we use round-robin. Better algorithm is welcomed.
1774 int mem_cgroup_select_victim_node(struct mem_cgroup
*memcg
)
1778 mem_cgroup_may_update_nodemask(memcg
);
1779 node
= memcg
->last_scanned_node
;
1781 node
= next_node(node
, memcg
->scan_nodes
);
1782 if (node
== MAX_NUMNODES
)
1783 node
= first_node(memcg
->scan_nodes
);
1785 * We call this when we hit limit, not when pages are added to LRU.
1786 * No LRU may hold pages because all pages are UNEVICTABLE or
1787 * memcg is too small and all pages are not on LRU. In that case,
1788 * we use curret node.
1790 if (unlikely(node
== MAX_NUMNODES
))
1791 node
= numa_node_id();
1793 memcg
->last_scanned_node
= node
;
1798 * Check all nodes whether it contains reclaimable pages or not.
1799 * For quick scan, we make use of scan_nodes. This will allow us to skip
1800 * unused nodes. But scan_nodes is lazily updated and may not cotain
1801 * enough new information. We need to do double check.
1803 static bool mem_cgroup_reclaimable(struct mem_cgroup
*memcg
, bool noswap
)
1808 * quick check...making use of scan_node.
1809 * We can skip unused nodes.
1811 if (!nodes_empty(memcg
->scan_nodes
)) {
1812 for (nid
= first_node(memcg
->scan_nodes
);
1814 nid
= next_node(nid
, memcg
->scan_nodes
)) {
1816 if (test_mem_cgroup_node_reclaimable(memcg
, nid
, noswap
))
1821 * Check rest of nodes.
1823 for_each_node_state(nid
, N_MEMORY
) {
1824 if (node_isset(nid
, memcg
->scan_nodes
))
1826 if (test_mem_cgroup_node_reclaimable(memcg
, nid
, noswap
))
1833 int mem_cgroup_select_victim_node(struct mem_cgroup
*memcg
)
1838 static bool mem_cgroup_reclaimable(struct mem_cgroup
*memcg
, bool noswap
)
1840 return test_mem_cgroup_node_reclaimable(memcg
, 0, noswap
);
1844 static int mem_cgroup_soft_reclaim(struct mem_cgroup
*root_memcg
,
1847 unsigned long *total_scanned
)
1849 struct mem_cgroup
*victim
= NULL
;
1852 unsigned long excess
;
1853 unsigned long nr_scanned
;
1854 struct mem_cgroup_reclaim_cookie reclaim
= {
1859 excess
= soft_limit_excess(root_memcg
);
1862 victim
= mem_cgroup_iter(root_memcg
, victim
, &reclaim
);
1867 * If we have not been able to reclaim
1868 * anything, it might because there are
1869 * no reclaimable pages under this hierarchy
1874 * We want to do more targeted reclaim.
1875 * excess >> 2 is not to excessive so as to
1876 * reclaim too much, nor too less that we keep
1877 * coming back to reclaim from this cgroup
1879 if (total
>= (excess
>> 2) ||
1880 (loop
> MEM_CGROUP_MAX_RECLAIM_LOOPS
))
1885 if (!mem_cgroup_reclaimable(victim
, false))
1887 total
+= mem_cgroup_shrink_node_zone(victim
, gfp_mask
, false,
1889 *total_scanned
+= nr_scanned
;
1890 if (!soft_limit_excess(root_memcg
))
1893 mem_cgroup_iter_break(root_memcg
, victim
);
1897 #ifdef CONFIG_LOCKDEP
1898 static struct lockdep_map memcg_oom_lock_dep_map
= {
1899 .name
= "memcg_oom_lock",
1903 static DEFINE_SPINLOCK(memcg_oom_lock
);
1906 * Check OOM-Killer is already running under our hierarchy.
1907 * If someone is running, return false.
1909 static bool mem_cgroup_oom_trylock(struct mem_cgroup
*memcg
)
1911 struct mem_cgroup
*iter
, *failed
= NULL
;
1913 spin_lock(&memcg_oom_lock
);
1915 for_each_mem_cgroup_tree(iter
, memcg
) {
1916 if (iter
->oom_lock
) {
1918 * this subtree of our hierarchy is already locked
1919 * so we cannot give a lock.
1922 mem_cgroup_iter_break(memcg
, iter
);
1925 iter
->oom_lock
= true;
1930 * OK, we failed to lock the whole subtree so we have
1931 * to clean up what we set up to the failing subtree
1933 for_each_mem_cgroup_tree(iter
, memcg
) {
1934 if (iter
== failed
) {
1935 mem_cgroup_iter_break(memcg
, iter
);
1938 iter
->oom_lock
= false;
1941 mutex_acquire(&memcg_oom_lock_dep_map
, 0, 1, _RET_IP_
);
1943 spin_unlock(&memcg_oom_lock
);
1948 static void mem_cgroup_oom_unlock(struct mem_cgroup
*memcg
)
1950 struct mem_cgroup
*iter
;
1952 spin_lock(&memcg_oom_lock
);
1953 mutex_release(&memcg_oom_lock_dep_map
, 1, _RET_IP_
);
1954 for_each_mem_cgroup_tree(iter
, memcg
)
1955 iter
->oom_lock
= false;
1956 spin_unlock(&memcg_oom_lock
);
1959 static void mem_cgroup_mark_under_oom(struct mem_cgroup
*memcg
)
1961 struct mem_cgroup
*iter
;
1963 for_each_mem_cgroup_tree(iter
, memcg
)
1964 atomic_inc(&iter
->under_oom
);
1967 static void mem_cgroup_unmark_under_oom(struct mem_cgroup
*memcg
)
1969 struct mem_cgroup
*iter
;
1972 * When a new child is created while the hierarchy is under oom,
1973 * mem_cgroup_oom_lock() may not be called. We have to use
1974 * atomic_add_unless() here.
1976 for_each_mem_cgroup_tree(iter
, memcg
)
1977 atomic_add_unless(&iter
->under_oom
, -1, 0);
1980 static DECLARE_WAIT_QUEUE_HEAD(memcg_oom_waitq
);
1982 struct oom_wait_info
{
1983 struct mem_cgroup
*memcg
;
1987 static int memcg_oom_wake_function(wait_queue_t
*wait
,
1988 unsigned mode
, int sync
, void *arg
)
1990 struct mem_cgroup
*wake_memcg
= (struct mem_cgroup
*)arg
;
1991 struct mem_cgroup
*oom_wait_memcg
;
1992 struct oom_wait_info
*oom_wait_info
;
1994 oom_wait_info
= container_of(wait
, struct oom_wait_info
, wait
);
1995 oom_wait_memcg
= oom_wait_info
->memcg
;
1998 * Both of oom_wait_info->memcg and wake_memcg are stable under us.
1999 * Then we can use css_is_ancestor without taking care of RCU.
2001 if (!mem_cgroup_same_or_subtree(oom_wait_memcg
, wake_memcg
)
2002 && !mem_cgroup_same_or_subtree(wake_memcg
, oom_wait_memcg
))
2004 return autoremove_wake_function(wait
, mode
, sync
, arg
);
2007 static void memcg_wakeup_oom(struct mem_cgroup
*memcg
)
2009 atomic_inc(&memcg
->oom_wakeups
);
2010 /* for filtering, pass "memcg" as argument. */
2011 __wake_up(&memcg_oom_waitq
, TASK_NORMAL
, 0, memcg
);
2014 static void memcg_oom_recover(struct mem_cgroup
*memcg
)
2016 if (memcg
&& atomic_read(&memcg
->under_oom
))
2017 memcg_wakeup_oom(memcg
);
2020 static void mem_cgroup_oom(struct mem_cgroup
*memcg
, gfp_t mask
, int order
)
2022 if (!current
->memcg_oom
.may_oom
)
2025 * We are in the middle of the charge context here, so we
2026 * don't want to block when potentially sitting on a callstack
2027 * that holds all kinds of filesystem and mm locks.
2029 * Also, the caller may handle a failed allocation gracefully
2030 * (like optional page cache readahead) and so an OOM killer
2031 * invocation might not even be necessary.
2033 * That's why we don't do anything here except remember the
2034 * OOM context and then deal with it at the end of the page
2035 * fault when the stack is unwound, the locks are released,
2036 * and when we know whether the fault was overall successful.
2038 css_get(&memcg
->css
);
2039 current
->memcg_oom
.memcg
= memcg
;
2040 current
->memcg_oom
.gfp_mask
= mask
;
2041 current
->memcg_oom
.order
= order
;
2045 * mem_cgroup_oom_synchronize - complete memcg OOM handling
2046 * @handle: actually kill/wait or just clean up the OOM state
2048 * This has to be called at the end of a page fault if the memcg OOM
2049 * handler was enabled.
2051 * Memcg supports userspace OOM handling where failed allocations must
2052 * sleep on a waitqueue until the userspace task resolves the
2053 * situation. Sleeping directly in the charge context with all kinds
2054 * of locks held is not a good idea, instead we remember an OOM state
2055 * in the task and mem_cgroup_oom_synchronize() has to be called at
2056 * the end of the page fault to complete the OOM handling.
2058 * Returns %true if an ongoing memcg OOM situation was detected and
2059 * completed, %false otherwise.
2061 bool mem_cgroup_oom_synchronize(bool handle
)
2063 struct mem_cgroup
*memcg
= current
->memcg_oom
.memcg
;
2064 struct oom_wait_info owait
;
2067 /* OOM is global, do not handle */
2074 owait
.memcg
= memcg
;
2075 owait
.wait
.flags
= 0;
2076 owait
.wait
.func
= memcg_oom_wake_function
;
2077 owait
.wait
.private = current
;
2078 INIT_LIST_HEAD(&owait
.wait
.task_list
);
2080 prepare_to_wait(&memcg_oom_waitq
, &owait
.wait
, TASK_KILLABLE
);
2081 mem_cgroup_mark_under_oom(memcg
);
2083 locked
= mem_cgroup_oom_trylock(memcg
);
2086 mem_cgroup_oom_notify(memcg
);
2088 if (locked
&& !memcg
->oom_kill_disable
) {
2089 mem_cgroup_unmark_under_oom(memcg
);
2090 finish_wait(&memcg_oom_waitq
, &owait
.wait
);
2091 mem_cgroup_out_of_memory(memcg
, current
->memcg_oom
.gfp_mask
,
2092 current
->memcg_oom
.order
);
2095 mem_cgroup_unmark_under_oom(memcg
);
2096 finish_wait(&memcg_oom_waitq
, &owait
.wait
);
2100 mem_cgroup_oom_unlock(memcg
);
2102 * There is no guarantee that an OOM-lock contender
2103 * sees the wakeups triggered by the OOM kill
2104 * uncharges. Wake any sleepers explicitely.
2106 memcg_oom_recover(memcg
);
2109 current
->memcg_oom
.memcg
= NULL
;
2110 css_put(&memcg
->css
);
2115 * mem_cgroup_begin_page_stat - begin a page state statistics transaction
2116 * @page: page that is going to change accounted state
2117 * @locked: &memcg->move_lock slowpath was taken
2118 * @flags: IRQ-state flags for &memcg->move_lock
2120 * This function must mark the beginning of an accounted page state
2121 * change to prevent double accounting when the page is concurrently
2122 * being moved to another memcg:
2124 * memcg = mem_cgroup_begin_page_stat(page, &locked, &flags);
2125 * if (TestClearPageState(page))
2126 * mem_cgroup_update_page_stat(memcg, state, -1);
2127 * mem_cgroup_end_page_stat(memcg, locked, flags);
2129 * The RCU lock is held throughout the transaction. The fast path can
2130 * get away without acquiring the memcg->move_lock (@locked is false)
2131 * because page moving starts with an RCU grace period.
2133 * The RCU lock also protects the memcg from being freed when the page
2134 * state that is going to change is the only thing preventing the page
2135 * from being uncharged. E.g. end-writeback clearing PageWriteback(),
2136 * which allows migration to go ahead and uncharge the page before the
2137 * account transaction might be complete.
2139 struct mem_cgroup
*mem_cgroup_begin_page_stat(struct page
*page
,
2141 unsigned long *flags
)
2143 struct mem_cgroup
*memcg
;
2144 struct page_cgroup
*pc
;
2148 if (mem_cgroup_disabled())
2151 pc
= lookup_page_cgroup(page
);
2153 memcg
= pc
->mem_cgroup
;
2154 if (unlikely(!memcg
|| !PageCgroupUsed(pc
)))
2158 if (atomic_read(&memcg
->moving_account
) <= 0)
2161 move_lock_mem_cgroup(memcg
, flags
);
2162 if (memcg
!= pc
->mem_cgroup
|| !PageCgroupUsed(pc
)) {
2163 move_unlock_mem_cgroup(memcg
, flags
);
2172 * mem_cgroup_end_page_stat - finish a page state statistics transaction
2173 * @memcg: the memcg that was accounted against
2174 * @locked: value received from mem_cgroup_begin_page_stat()
2175 * @flags: value received from mem_cgroup_begin_page_stat()
2177 void mem_cgroup_end_page_stat(struct mem_cgroup
*memcg
, bool locked
,
2178 unsigned long flags
)
2180 if (memcg
&& locked
)
2181 move_unlock_mem_cgroup(memcg
, &flags
);
2187 * mem_cgroup_update_page_stat - update page state statistics
2188 * @memcg: memcg to account against
2189 * @idx: page state item to account
2190 * @val: number of pages (positive or negative)
2192 * See mem_cgroup_begin_page_stat() for locking requirements.
2194 void mem_cgroup_update_page_stat(struct mem_cgroup
*memcg
,
2195 enum mem_cgroup_stat_index idx
, int val
)
2197 VM_BUG_ON(!rcu_read_lock_held());
2200 this_cpu_add(memcg
->stat
->count
[idx
], val
);
2204 * size of first charge trial. "32" comes from vmscan.c's magic value.
2205 * TODO: maybe necessary to use big numbers in big irons.
2207 #define CHARGE_BATCH 32U
2208 struct memcg_stock_pcp
{
2209 struct mem_cgroup
*cached
; /* this never be root cgroup */
2210 unsigned int nr_pages
;
2211 struct work_struct work
;
2212 unsigned long flags
;
2213 #define FLUSHING_CACHED_CHARGE 0
2215 static DEFINE_PER_CPU(struct memcg_stock_pcp
, memcg_stock
);
2216 static DEFINE_MUTEX(percpu_charge_mutex
);
2219 * consume_stock: Try to consume stocked charge on this cpu.
2220 * @memcg: memcg to consume from.
2221 * @nr_pages: how many pages to charge.
2223 * The charges will only happen if @memcg matches the current cpu's memcg
2224 * stock, and at least @nr_pages are available in that stock. Failure to
2225 * service an allocation will refill the stock.
2227 * returns true if successful, false otherwise.
2229 static bool consume_stock(struct mem_cgroup
*memcg
, unsigned int nr_pages
)
2231 struct memcg_stock_pcp
*stock
;
2234 if (nr_pages
> CHARGE_BATCH
)
2237 stock
= &get_cpu_var(memcg_stock
);
2238 if (memcg
== stock
->cached
&& stock
->nr_pages
>= nr_pages
) {
2239 stock
->nr_pages
-= nr_pages
;
2242 put_cpu_var(memcg_stock
);
2247 * Returns stocks cached in percpu and reset cached information.
2249 static void drain_stock(struct memcg_stock_pcp
*stock
)
2251 struct mem_cgroup
*old
= stock
->cached
;
2253 if (stock
->nr_pages
) {
2254 page_counter_uncharge(&old
->memory
, stock
->nr_pages
);
2255 if (do_swap_account
)
2256 page_counter_uncharge(&old
->memsw
, stock
->nr_pages
);
2257 css_put_many(&old
->css
, stock
->nr_pages
);
2258 stock
->nr_pages
= 0;
2260 stock
->cached
= NULL
;
2264 * This must be called under preempt disabled or must be called by
2265 * a thread which is pinned to local cpu.
2267 static void drain_local_stock(struct work_struct
*dummy
)
2269 struct memcg_stock_pcp
*stock
= this_cpu_ptr(&memcg_stock
);
2271 clear_bit(FLUSHING_CACHED_CHARGE
, &stock
->flags
);
2274 static void __init
memcg_stock_init(void)
2278 for_each_possible_cpu(cpu
) {
2279 struct memcg_stock_pcp
*stock
=
2280 &per_cpu(memcg_stock
, cpu
);
2281 INIT_WORK(&stock
->work
, drain_local_stock
);
2286 * Cache charges(val) to local per_cpu area.
2287 * This will be consumed by consume_stock() function, later.
2289 static void refill_stock(struct mem_cgroup
*memcg
, unsigned int nr_pages
)
2291 struct memcg_stock_pcp
*stock
= &get_cpu_var(memcg_stock
);
2293 if (stock
->cached
!= memcg
) { /* reset if necessary */
2295 stock
->cached
= memcg
;
2297 stock
->nr_pages
+= nr_pages
;
2298 put_cpu_var(memcg_stock
);
2302 * Drains all per-CPU charge caches for given root_memcg resp. subtree
2303 * of the hierarchy under it.
2305 static void drain_all_stock(struct mem_cgroup
*root_memcg
)
2309 /* If someone's already draining, avoid adding running more workers. */
2310 if (!mutex_trylock(&percpu_charge_mutex
))
2312 /* Notify other cpus that system-wide "drain" is running */
2315 for_each_online_cpu(cpu
) {
2316 struct memcg_stock_pcp
*stock
= &per_cpu(memcg_stock
, cpu
);
2317 struct mem_cgroup
*memcg
;
2319 memcg
= stock
->cached
;
2320 if (!memcg
|| !stock
->nr_pages
)
2322 if (!mem_cgroup_same_or_subtree(root_memcg
, memcg
))
2324 if (!test_and_set_bit(FLUSHING_CACHED_CHARGE
, &stock
->flags
)) {
2326 drain_local_stock(&stock
->work
);
2328 schedule_work_on(cpu
, &stock
->work
);
2333 mutex_unlock(&percpu_charge_mutex
);
2337 * This function drains percpu counter value from DEAD cpu and
2338 * move it to local cpu. Note that this function can be preempted.
2340 static void mem_cgroup_drain_pcp_counter(struct mem_cgroup
*memcg
, int cpu
)
2344 spin_lock(&memcg
->pcp_counter_lock
);
2345 for (i
= 0; i
< MEM_CGROUP_STAT_NSTATS
; i
++) {
2346 long x
= per_cpu(memcg
->stat
->count
[i
], cpu
);
2348 per_cpu(memcg
->stat
->count
[i
], cpu
) = 0;
2349 memcg
->nocpu_base
.count
[i
] += x
;
2351 for (i
= 0; i
< MEM_CGROUP_EVENTS_NSTATS
; i
++) {
2352 unsigned long x
= per_cpu(memcg
->stat
->events
[i
], cpu
);
2354 per_cpu(memcg
->stat
->events
[i
], cpu
) = 0;
2355 memcg
->nocpu_base
.events
[i
] += x
;
2357 spin_unlock(&memcg
->pcp_counter_lock
);
2360 static int memcg_cpu_hotplug_callback(struct notifier_block
*nb
,
2361 unsigned long action
,
2364 int cpu
= (unsigned long)hcpu
;
2365 struct memcg_stock_pcp
*stock
;
2366 struct mem_cgroup
*iter
;
2368 if (action
== CPU_ONLINE
)
2371 if (action
!= CPU_DEAD
&& action
!= CPU_DEAD_FROZEN
)
2374 for_each_mem_cgroup(iter
)
2375 mem_cgroup_drain_pcp_counter(iter
, cpu
);
2377 stock
= &per_cpu(memcg_stock
, cpu
);
2382 static int try_charge(struct mem_cgroup
*memcg
, gfp_t gfp_mask
,
2383 unsigned int nr_pages
)
2385 unsigned int batch
= max(CHARGE_BATCH
, nr_pages
);
2386 int nr_retries
= MEM_CGROUP_RECLAIM_RETRIES
;
2387 struct mem_cgroup
*mem_over_limit
;
2388 struct page_counter
*counter
;
2389 unsigned long nr_reclaimed
;
2390 bool may_swap
= true;
2391 bool drained
= false;
2394 if (mem_cgroup_is_root(memcg
))
2397 if (consume_stock(memcg
, nr_pages
))
2400 if (!do_swap_account
||
2401 !page_counter_try_charge(&memcg
->memsw
, batch
, &counter
)) {
2402 if (!page_counter_try_charge(&memcg
->memory
, batch
, &counter
))
2404 if (do_swap_account
)
2405 page_counter_uncharge(&memcg
->memsw
, batch
);
2406 mem_over_limit
= mem_cgroup_from_counter(counter
, memory
);
2408 mem_over_limit
= mem_cgroup_from_counter(counter
, memsw
);
2412 if (batch
> nr_pages
) {
2418 * Unlike in global OOM situations, memcg is not in a physical
2419 * memory shortage. Allow dying and OOM-killed tasks to
2420 * bypass the last charges so that they can exit quickly and
2421 * free their memory.
2423 if (unlikely(test_thread_flag(TIF_MEMDIE
) ||
2424 fatal_signal_pending(current
) ||
2425 current
->flags
& PF_EXITING
))
2428 if (unlikely(task_in_memcg_oom(current
)))
2431 if (!(gfp_mask
& __GFP_WAIT
))
2434 nr_reclaimed
= try_to_free_mem_cgroup_pages(mem_over_limit
, nr_pages
,
2435 gfp_mask
, may_swap
);
2437 if (mem_cgroup_margin(mem_over_limit
) >= nr_pages
)
2441 drain_all_stock(mem_over_limit
);
2446 if (gfp_mask
& __GFP_NORETRY
)
2449 * Even though the limit is exceeded at this point, reclaim
2450 * may have been able to free some pages. Retry the charge
2451 * before killing the task.
2453 * Only for regular pages, though: huge pages are rather
2454 * unlikely to succeed so close to the limit, and we fall back
2455 * to regular pages anyway in case of failure.
2457 if (nr_reclaimed
&& nr_pages
<= (1 << PAGE_ALLOC_COSTLY_ORDER
))
2460 * At task move, charge accounts can be doubly counted. So, it's
2461 * better to wait until the end of task_move if something is going on.
2463 if (mem_cgroup_wait_acct_move(mem_over_limit
))
2469 if (gfp_mask
& __GFP_NOFAIL
)
2472 if (fatal_signal_pending(current
))
2475 mem_cgroup_oom(mem_over_limit
, gfp_mask
, get_order(nr_pages
));
2477 if (!(gfp_mask
& __GFP_NOFAIL
))
2483 css_get_many(&memcg
->css
, batch
);
2484 if (batch
> nr_pages
)
2485 refill_stock(memcg
, batch
- nr_pages
);
2490 static void cancel_charge(struct mem_cgroup
*memcg
, unsigned int nr_pages
)
2492 if (mem_cgroup_is_root(memcg
))
2495 page_counter_uncharge(&memcg
->memory
, nr_pages
);
2496 if (do_swap_account
)
2497 page_counter_uncharge(&memcg
->memsw
, nr_pages
);
2499 css_put_many(&memcg
->css
, nr_pages
);
2503 * A helper function to get mem_cgroup from ID. must be called under
2504 * rcu_read_lock(). The caller is responsible for calling
2505 * css_tryget_online() if the mem_cgroup is used for charging. (dropping
2506 * refcnt from swap can be called against removed memcg.)
2508 static struct mem_cgroup
*mem_cgroup_lookup(unsigned short id
)
2510 /* ID 0 is unused ID */
2513 return mem_cgroup_from_id(id
);
2517 * try_get_mem_cgroup_from_page - look up page's memcg association
2520 * Look up, get a css reference, and return the memcg that owns @page.
2522 * The page must be locked to prevent racing with swap-in and page
2523 * cache charges. If coming from an unlocked page table, the caller
2524 * must ensure the page is on the LRU or this can race with charging.
2526 struct mem_cgroup
*try_get_mem_cgroup_from_page(struct page
*page
)
2528 struct mem_cgroup
*memcg
= NULL
;
2529 struct page_cgroup
*pc
;
2533 VM_BUG_ON_PAGE(!PageLocked(page
), page
);
2535 pc
= lookup_page_cgroup(page
);
2536 if (PageCgroupUsed(pc
)) {
2537 memcg
= pc
->mem_cgroup
;
2538 if (memcg
&& !css_tryget_online(&memcg
->css
))
2540 } else if (PageSwapCache(page
)) {
2541 ent
.val
= page_private(page
);
2542 id
= lookup_swap_cgroup_id(ent
);
2544 memcg
= mem_cgroup_lookup(id
);
2545 if (memcg
&& !css_tryget_online(&memcg
->css
))
2552 static void lock_page_lru(struct page
*page
, int *isolated
)
2554 struct zone
*zone
= page_zone(page
);
2556 spin_lock_irq(&zone
->lru_lock
);
2557 if (PageLRU(page
)) {
2558 struct lruvec
*lruvec
;
2560 lruvec
= mem_cgroup_page_lruvec(page
, zone
);
2562 del_page_from_lru_list(page
, lruvec
, page_lru(page
));
2568 static void unlock_page_lru(struct page
*page
, int isolated
)
2570 struct zone
*zone
= page_zone(page
);
2573 struct lruvec
*lruvec
;
2575 lruvec
= mem_cgroup_page_lruvec(page
, zone
);
2576 VM_BUG_ON_PAGE(PageLRU(page
), page
);
2578 add_page_to_lru_list(page
, lruvec
, page_lru(page
));
2580 spin_unlock_irq(&zone
->lru_lock
);
2583 static void commit_charge(struct page
*page
, struct mem_cgroup
*memcg
,
2586 struct page_cgroup
*pc
= lookup_page_cgroup(page
);
2589 VM_BUG_ON_PAGE(PageCgroupUsed(pc
), page
);
2591 * we don't need page_cgroup_lock about tail pages, becase they are not
2592 * accessed by any other context at this point.
2596 * In some cases, SwapCache and FUSE(splice_buf->radixtree), the page
2597 * may already be on some other mem_cgroup's LRU. Take care of it.
2600 lock_page_lru(page
, &isolated
);
2603 * Nobody should be changing or seriously looking at
2604 * pc->mem_cgroup and pc->flags at this point:
2606 * - the page is uncharged
2608 * - the page is off-LRU
2610 * - an anonymous fault has exclusive page access, except for
2611 * a locked page table
2613 * - a page cache insertion, a swapin fault, or a migration
2614 * have the page locked
2616 pc
->mem_cgroup
= memcg
;
2617 pc
->flags
= PCG_USED
| PCG_MEM
| (do_swap_account
? PCG_MEMSW
: 0);
2620 unlock_page_lru(page
, isolated
);
2623 #ifdef CONFIG_MEMCG_KMEM
2625 * The memcg_slab_mutex is held whenever a per memcg kmem cache is created or
2626 * destroyed. It protects memcg_caches arrays and memcg_slab_caches lists.
2628 static DEFINE_MUTEX(memcg_slab_mutex
);
2630 static DEFINE_MUTEX(activate_kmem_mutex
);
2633 * This is a bit cumbersome, but it is rarely used and avoids a backpointer
2634 * in the memcg_cache_params struct.
2636 static struct kmem_cache
*memcg_params_to_cache(struct memcg_cache_params
*p
)
2638 struct kmem_cache
*cachep
;
2640 VM_BUG_ON(p
->is_root_cache
);
2641 cachep
= p
->root_cache
;
2642 return cache_from_memcg_idx(cachep
, memcg_cache_id(p
->memcg
));
2645 #ifdef CONFIG_SLABINFO
2646 static int mem_cgroup_slabinfo_read(struct seq_file
*m
, void *v
)
2648 struct mem_cgroup
*memcg
= mem_cgroup_from_css(seq_css(m
));
2649 struct memcg_cache_params
*params
;
2651 if (!memcg_kmem_is_active(memcg
))
2654 print_slabinfo_header(m
);
2656 mutex_lock(&memcg_slab_mutex
);
2657 list_for_each_entry(params
, &memcg
->memcg_slab_caches
, list
)
2658 cache_show(memcg_params_to_cache(params
), m
);
2659 mutex_unlock(&memcg_slab_mutex
);
2665 static int memcg_charge_kmem(struct mem_cgroup
*memcg
, gfp_t gfp
,
2666 unsigned long nr_pages
)
2668 struct page_counter
*counter
;
2671 ret
= page_counter_try_charge(&memcg
->kmem
, nr_pages
, &counter
);
2675 ret
= try_charge(memcg
, gfp
, nr_pages
);
2676 if (ret
== -EINTR
) {
2678 * try_charge() chose to bypass to root due to OOM kill or
2679 * fatal signal. Since our only options are to either fail
2680 * the allocation or charge it to this cgroup, do it as a
2681 * temporary condition. But we can't fail. From a kmem/slab
2682 * perspective, the cache has already been selected, by
2683 * mem_cgroup_kmem_get_cache(), so it is too late to change
2686 * This condition will only trigger if the task entered
2687 * memcg_charge_kmem in a sane state, but was OOM-killed
2688 * during try_charge() above. Tasks that were already dying
2689 * when the allocation triggers should have been already
2690 * directed to the root cgroup in memcontrol.h
2692 page_counter_charge(&memcg
->memory
, nr_pages
);
2693 if (do_swap_account
)
2694 page_counter_charge(&memcg
->memsw
, nr_pages
);
2695 css_get_many(&memcg
->css
, nr_pages
);
2698 page_counter_uncharge(&memcg
->kmem
, nr_pages
);
2703 static void memcg_uncharge_kmem(struct mem_cgroup
*memcg
,
2704 unsigned long nr_pages
)
2706 page_counter_uncharge(&memcg
->memory
, nr_pages
);
2707 if (do_swap_account
)
2708 page_counter_uncharge(&memcg
->memsw
, nr_pages
);
2710 page_counter_uncharge(&memcg
->kmem
, nr_pages
);
2712 css_put_many(&memcg
->css
, nr_pages
);
2716 * helper for acessing a memcg's index. It will be used as an index in the
2717 * child cache array in kmem_cache, and also to derive its name. This function
2718 * will return -1 when this is not a kmem-limited memcg.
2720 int memcg_cache_id(struct mem_cgroup
*memcg
)
2722 return memcg
? memcg
->kmemcg_id
: -1;
2725 static int memcg_alloc_cache_id(void)
2730 id
= ida_simple_get(&kmem_limited_groups
,
2731 0, MEMCG_CACHES_MAX_SIZE
, GFP_KERNEL
);
2735 if (id
< memcg_limited_groups_array_size
)
2739 * There's no space for the new id in memcg_caches arrays,
2740 * so we have to grow them.
2743 size
= 2 * (id
+ 1);
2744 if (size
< MEMCG_CACHES_MIN_SIZE
)
2745 size
= MEMCG_CACHES_MIN_SIZE
;
2746 else if (size
> MEMCG_CACHES_MAX_SIZE
)
2747 size
= MEMCG_CACHES_MAX_SIZE
;
2749 mutex_lock(&memcg_slab_mutex
);
2750 err
= memcg_update_all_caches(size
);
2751 mutex_unlock(&memcg_slab_mutex
);
2754 ida_simple_remove(&kmem_limited_groups
, id
);
2760 static void memcg_free_cache_id(int id
)
2762 ida_simple_remove(&kmem_limited_groups
, id
);
2766 * We should update the current array size iff all caches updates succeed. This
2767 * can only be done from the slab side. The slab mutex needs to be held when
2770 void memcg_update_array_size(int num
)
2772 memcg_limited_groups_array_size
= num
;
2775 static void memcg_register_cache(struct mem_cgroup
*memcg
,
2776 struct kmem_cache
*root_cache
)
2778 static char memcg_name_buf
[NAME_MAX
+ 1]; /* protected by
2780 struct kmem_cache
*cachep
;
2783 lockdep_assert_held(&memcg_slab_mutex
);
2785 id
= memcg_cache_id(memcg
);
2788 * Since per-memcg caches are created asynchronously on first
2789 * allocation (see memcg_kmem_get_cache()), several threads can try to
2790 * create the same cache, but only one of them may succeed.
2792 if (cache_from_memcg_idx(root_cache
, id
))
2795 cgroup_name(memcg
->css
.cgroup
, memcg_name_buf
, NAME_MAX
+ 1);
2796 cachep
= memcg_create_kmem_cache(memcg
, root_cache
, memcg_name_buf
);
2798 * If we could not create a memcg cache, do not complain, because
2799 * that's not critical at all as we can always proceed with the root
2805 css_get(&memcg
->css
);
2806 list_add(&cachep
->memcg_params
->list
, &memcg
->memcg_slab_caches
);
2809 * Since readers won't lock (see cache_from_memcg_idx()), we need a
2810 * barrier here to ensure nobody will see the kmem_cache partially
2815 BUG_ON(root_cache
->memcg_params
->memcg_caches
[id
]);
2816 root_cache
->memcg_params
->memcg_caches
[id
] = cachep
;
2819 static void memcg_unregister_cache(struct kmem_cache
*cachep
)
2821 struct kmem_cache
*root_cache
;
2822 struct mem_cgroup
*memcg
;
2825 lockdep_assert_held(&memcg_slab_mutex
);
2827 BUG_ON(is_root_cache(cachep
));
2829 root_cache
= cachep
->memcg_params
->root_cache
;
2830 memcg
= cachep
->memcg_params
->memcg
;
2831 id
= memcg_cache_id(memcg
);
2833 BUG_ON(root_cache
->memcg_params
->memcg_caches
[id
] != cachep
);
2834 root_cache
->memcg_params
->memcg_caches
[id
] = NULL
;
2836 list_del(&cachep
->memcg_params
->list
);
2838 kmem_cache_destroy(cachep
);
2840 /* drop the reference taken in memcg_register_cache */
2841 css_put(&memcg
->css
);
2845 * During the creation a new cache, we need to disable our accounting mechanism
2846 * altogether. This is true even if we are not creating, but rather just
2847 * enqueing new caches to be created.
2849 * This is because that process will trigger allocations; some visible, like
2850 * explicit kmallocs to auxiliary data structures, name strings and internal
2851 * cache structures; some well concealed, like INIT_WORK() that can allocate
2852 * objects during debug.
2854 * If any allocation happens during memcg_kmem_get_cache, we will recurse back
2855 * to it. This may not be a bounded recursion: since the first cache creation
2856 * failed to complete (waiting on the allocation), we'll just try to create the
2857 * cache again, failing at the same point.
2859 * memcg_kmem_get_cache is prepared to abort after seeing a positive count of
2860 * memcg_kmem_skip_account. So we enclose anything that might allocate memory
2861 * inside the following two functions.
2863 static inline void memcg_stop_kmem_account(void)
2865 VM_BUG_ON(!current
->mm
);
2866 current
->memcg_kmem_skip_account
++;
2869 static inline void memcg_resume_kmem_account(void)
2871 VM_BUG_ON(!current
->mm
);
2872 current
->memcg_kmem_skip_account
--;
2875 int __memcg_cleanup_cache_params(struct kmem_cache
*s
)
2877 struct kmem_cache
*c
;
2880 mutex_lock(&memcg_slab_mutex
);
2881 for_each_memcg_cache_index(i
) {
2882 c
= cache_from_memcg_idx(s
, i
);
2886 memcg_unregister_cache(c
);
2888 if (cache_from_memcg_idx(s
, i
))
2891 mutex_unlock(&memcg_slab_mutex
);
2895 static void memcg_unregister_all_caches(struct mem_cgroup
*memcg
)
2897 struct kmem_cache
*cachep
;
2898 struct memcg_cache_params
*params
, *tmp
;
2900 if (!memcg_kmem_is_active(memcg
))
2903 mutex_lock(&memcg_slab_mutex
);
2904 list_for_each_entry_safe(params
, tmp
, &memcg
->memcg_slab_caches
, list
) {
2905 cachep
= memcg_params_to_cache(params
);
2906 kmem_cache_shrink(cachep
);
2907 if (atomic_read(&cachep
->memcg_params
->nr_pages
) == 0)
2908 memcg_unregister_cache(cachep
);
2910 mutex_unlock(&memcg_slab_mutex
);
2913 struct memcg_register_cache_work
{
2914 struct mem_cgroup
*memcg
;
2915 struct kmem_cache
*cachep
;
2916 struct work_struct work
;
2919 static void memcg_register_cache_func(struct work_struct
*w
)
2921 struct memcg_register_cache_work
*cw
=
2922 container_of(w
, struct memcg_register_cache_work
, work
);
2923 struct mem_cgroup
*memcg
= cw
->memcg
;
2924 struct kmem_cache
*cachep
= cw
->cachep
;
2926 mutex_lock(&memcg_slab_mutex
);
2927 memcg_register_cache(memcg
, cachep
);
2928 mutex_unlock(&memcg_slab_mutex
);
2930 css_put(&memcg
->css
);
2935 * Enqueue the creation of a per-memcg kmem_cache.
2937 static void __memcg_schedule_register_cache(struct mem_cgroup
*memcg
,
2938 struct kmem_cache
*cachep
)
2940 struct memcg_register_cache_work
*cw
;
2942 cw
= kmalloc(sizeof(*cw
), GFP_NOWAIT
);
2944 css_put(&memcg
->css
);
2949 cw
->cachep
= cachep
;
2951 INIT_WORK(&cw
->work
, memcg_register_cache_func
);
2952 schedule_work(&cw
->work
);
2955 static void memcg_schedule_register_cache(struct mem_cgroup
*memcg
,
2956 struct kmem_cache
*cachep
)
2959 * We need to stop accounting when we kmalloc, because if the
2960 * corresponding kmalloc cache is not yet created, the first allocation
2961 * in __memcg_schedule_register_cache will recurse.
2963 * However, it is better to enclose the whole function. Depending on
2964 * the debugging options enabled, INIT_WORK(), for instance, can
2965 * trigger an allocation. This too, will make us recurse. Because at
2966 * this point we can't allow ourselves back into memcg_kmem_get_cache,
2967 * the safest choice is to do it like this, wrapping the whole function.
2969 memcg_stop_kmem_account();
2970 __memcg_schedule_register_cache(memcg
, cachep
);
2971 memcg_resume_kmem_account();
2974 int __memcg_charge_slab(struct kmem_cache
*cachep
, gfp_t gfp
, int order
)
2976 unsigned int nr_pages
= 1 << order
;
2979 res
= memcg_charge_kmem(cachep
->memcg_params
->memcg
, gfp
, nr_pages
);
2981 atomic_add(nr_pages
, &cachep
->memcg_params
->nr_pages
);
2985 void __memcg_uncharge_slab(struct kmem_cache
*cachep
, int order
)
2987 unsigned int nr_pages
= 1 << order
;
2989 memcg_uncharge_kmem(cachep
->memcg_params
->memcg
, nr_pages
);
2990 atomic_sub(nr_pages
, &cachep
->memcg_params
->nr_pages
);
2994 * Return the kmem_cache we're supposed to use for a slab allocation.
2995 * We try to use the current memcg's version of the cache.
2997 * If the cache does not exist yet, if we are the first user of it,
2998 * we either create it immediately, if possible, or create it asynchronously
3000 * In the latter case, we will let the current allocation go through with
3001 * the original cache.
3003 * Can't be called in interrupt context or from kernel threads.
3004 * This function needs to be called with rcu_read_lock() held.
3006 struct kmem_cache
*__memcg_kmem_get_cache(struct kmem_cache
*cachep
,
3009 struct mem_cgroup
*memcg
;
3010 struct kmem_cache
*memcg_cachep
;
3012 VM_BUG_ON(!cachep
->memcg_params
);
3013 VM_BUG_ON(!cachep
->memcg_params
->is_root_cache
);
3015 if (!current
->mm
|| current
->memcg_kmem_skip_account
)
3019 memcg
= mem_cgroup_from_task(rcu_dereference(current
->mm
->owner
));
3021 if (!memcg_kmem_is_active(memcg
))
3024 memcg_cachep
= cache_from_memcg_idx(cachep
, memcg_cache_id(memcg
));
3025 if (likely(memcg_cachep
)) {
3026 cachep
= memcg_cachep
;
3030 /* The corresponding put will be done in the workqueue. */
3031 if (!css_tryget_online(&memcg
->css
))
3036 * If we are in a safe context (can wait, and not in interrupt
3037 * context), we could be be predictable and return right away.
3038 * This would guarantee that the allocation being performed
3039 * already belongs in the new cache.
3041 * However, there are some clashes that can arrive from locking.
3042 * For instance, because we acquire the slab_mutex while doing
3043 * memcg_create_kmem_cache, this means no further allocation
3044 * could happen with the slab_mutex held. So it's better to
3047 memcg_schedule_register_cache(memcg
, cachep
);
3055 * We need to verify if the allocation against current->mm->owner's memcg is
3056 * possible for the given order. But the page is not allocated yet, so we'll
3057 * need a further commit step to do the final arrangements.
3059 * It is possible for the task to switch cgroups in this mean time, so at
3060 * commit time, we can't rely on task conversion any longer. We'll then use
3061 * the handle argument to return to the caller which cgroup we should commit
3062 * against. We could also return the memcg directly and avoid the pointer
3063 * passing, but a boolean return value gives better semantics considering
3064 * the compiled-out case as well.
3066 * Returning true means the allocation is possible.
3069 __memcg_kmem_newpage_charge(gfp_t gfp
, struct mem_cgroup
**_memcg
, int order
)
3071 struct mem_cgroup
*memcg
;
3077 * Disabling accounting is only relevant for some specific memcg
3078 * internal allocations. Therefore we would initially not have such
3079 * check here, since direct calls to the page allocator that are
3080 * accounted to kmemcg (alloc_kmem_pages and friends) only happen
3081 * outside memcg core. We are mostly concerned with cache allocations,
3082 * and by having this test at memcg_kmem_get_cache, we are already able
3083 * to relay the allocation to the root cache and bypass the memcg cache
3086 * There is one exception, though: the SLUB allocator does not create
3087 * large order caches, but rather service large kmallocs directly from
3088 * the page allocator. Therefore, the following sequence when backed by
3089 * the SLUB allocator:
3091 * memcg_stop_kmem_account();
3092 * kmalloc(<large_number>)
3093 * memcg_resume_kmem_account();
3095 * would effectively ignore the fact that we should skip accounting,
3096 * since it will drive us directly to this function without passing
3097 * through the cache selector memcg_kmem_get_cache. Such large
3098 * allocations are extremely rare but can happen, for instance, for the
3099 * cache arrays. We bring this test here.
3101 if (!current
->mm
|| current
->memcg_kmem_skip_account
)
3104 memcg
= get_mem_cgroup_from_mm(current
->mm
);
3106 if (!memcg_kmem_is_active(memcg
)) {
3107 css_put(&memcg
->css
);
3111 ret
= memcg_charge_kmem(memcg
, gfp
, 1 << order
);
3115 css_put(&memcg
->css
);
3119 void __memcg_kmem_commit_charge(struct page
*page
, struct mem_cgroup
*memcg
,
3122 struct page_cgroup
*pc
;
3124 VM_BUG_ON(mem_cgroup_is_root(memcg
));
3126 /* The page allocation failed. Revert */
3128 memcg_uncharge_kmem(memcg
, 1 << order
);
3132 * The page is freshly allocated and not visible to any
3133 * outside callers yet. Set up pc non-atomically.
3135 pc
= lookup_page_cgroup(page
);
3136 pc
->mem_cgroup
= memcg
;
3137 pc
->flags
= PCG_USED
;
3140 void __memcg_kmem_uncharge_pages(struct page
*page
, int order
)
3142 struct mem_cgroup
*memcg
= NULL
;
3143 struct page_cgroup
*pc
;
3146 pc
= lookup_page_cgroup(page
);
3147 if (!PageCgroupUsed(pc
))
3150 memcg
= pc
->mem_cgroup
;
3154 * We trust that only if there is a memcg associated with the page, it
3155 * is a valid allocation
3160 VM_BUG_ON_PAGE(mem_cgroup_is_root(memcg
), page
);
3161 memcg_uncharge_kmem(memcg
, 1 << order
);
3164 static inline void memcg_unregister_all_caches(struct mem_cgroup
*memcg
)
3167 #endif /* CONFIG_MEMCG_KMEM */
3169 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
3172 * Because tail pages are not marked as "used", set it. We're under
3173 * zone->lru_lock, 'splitting on pmd' and compound_lock.
3174 * charge/uncharge will be never happen and move_account() is done under
3175 * compound_lock(), so we don't have to take care of races.
3177 void mem_cgroup_split_huge_fixup(struct page
*head
)
3179 struct page_cgroup
*head_pc
= lookup_page_cgroup(head
);
3180 struct page_cgroup
*pc
;
3181 struct mem_cgroup
*memcg
;
3184 if (mem_cgroup_disabled())
3187 memcg
= head_pc
->mem_cgroup
;
3188 for (i
= 1; i
< HPAGE_PMD_NR
; i
++) {
3190 pc
->mem_cgroup
= memcg
;
3191 pc
->flags
= head_pc
->flags
;
3193 __this_cpu_sub(memcg
->stat
->count
[MEM_CGROUP_STAT_RSS_HUGE
],
3196 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
3199 * mem_cgroup_move_account - move account of the page
3201 * @nr_pages: number of regular pages (>1 for huge pages)
3202 * @pc: page_cgroup of the page.
3203 * @from: mem_cgroup which the page is moved from.
3204 * @to: mem_cgroup which the page is moved to. @from != @to.
3206 * The caller must confirm following.
3207 * - page is not on LRU (isolate_page() is useful.)
3208 * - compound_lock is held when nr_pages > 1
3210 * This function doesn't do "charge" to new cgroup and doesn't do "uncharge"
3213 static int mem_cgroup_move_account(struct page
*page
,
3214 unsigned int nr_pages
,
3215 struct page_cgroup
*pc
,
3216 struct mem_cgroup
*from
,
3217 struct mem_cgroup
*to
)
3219 unsigned long flags
;
3222 VM_BUG_ON(from
== to
);
3223 VM_BUG_ON_PAGE(PageLRU(page
), page
);
3225 * The page is isolated from LRU. So, collapse function
3226 * will not handle this page. But page splitting can happen.
3227 * Do this check under compound_page_lock(). The caller should
3231 if (nr_pages
> 1 && !PageTransHuge(page
))
3235 * Prevent mem_cgroup_migrate() from looking at pc->mem_cgroup
3236 * of its source page while we change it: page migration takes
3237 * both pages off the LRU, but page cache replacement doesn't.
3239 if (!trylock_page(page
))
3243 if (!PageCgroupUsed(pc
) || pc
->mem_cgroup
!= from
)
3246 move_lock_mem_cgroup(from
, &flags
);
3248 if (!PageAnon(page
) && page_mapped(page
)) {
3249 __this_cpu_sub(from
->stat
->count
[MEM_CGROUP_STAT_FILE_MAPPED
],
3251 __this_cpu_add(to
->stat
->count
[MEM_CGROUP_STAT_FILE_MAPPED
],
3255 if (PageWriteback(page
)) {
3256 __this_cpu_sub(from
->stat
->count
[MEM_CGROUP_STAT_WRITEBACK
],
3258 __this_cpu_add(to
->stat
->count
[MEM_CGROUP_STAT_WRITEBACK
],
3263 * It is safe to change pc->mem_cgroup here because the page
3264 * is referenced, charged, and isolated - we can't race with
3265 * uncharging, charging, migration, or LRU putback.
3268 /* caller should have done css_get */
3269 pc
->mem_cgroup
= to
;
3270 move_unlock_mem_cgroup(from
, &flags
);
3273 local_irq_disable();
3274 mem_cgroup_charge_statistics(to
, page
, nr_pages
);
3275 memcg_check_events(to
, page
);
3276 mem_cgroup_charge_statistics(from
, page
, -nr_pages
);
3277 memcg_check_events(from
, page
);
3285 #ifdef CONFIG_MEMCG_SWAP
3286 static void mem_cgroup_swap_statistics(struct mem_cgroup
*memcg
,
3289 int val
= (charge
) ? 1 : -1;
3290 this_cpu_add(memcg
->stat
->count
[MEM_CGROUP_STAT_SWAP
], val
);
3294 * mem_cgroup_move_swap_account - move swap charge and swap_cgroup's record.
3295 * @entry: swap entry to be moved
3296 * @from: mem_cgroup which the entry is moved from
3297 * @to: mem_cgroup which the entry is moved to
3299 * It succeeds only when the swap_cgroup's record for this entry is the same
3300 * as the mem_cgroup's id of @from.
3302 * Returns 0 on success, -EINVAL on failure.
3304 * The caller must have charged to @to, IOW, called page_counter_charge() about
3305 * both res and memsw, and called css_get().
3307 static int mem_cgroup_move_swap_account(swp_entry_t entry
,
3308 struct mem_cgroup
*from
, struct mem_cgroup
*to
)
3310 unsigned short old_id
, new_id
;
3312 old_id
= mem_cgroup_id(from
);
3313 new_id
= mem_cgroup_id(to
);
3315 if (swap_cgroup_cmpxchg(entry
, old_id
, new_id
) == old_id
) {
3316 mem_cgroup_swap_statistics(from
, false);
3317 mem_cgroup_swap_statistics(to
, true);
3319 * This function is only called from task migration context now.
3320 * It postpones page_counter and refcount handling till the end
3321 * of task migration(mem_cgroup_clear_mc()) for performance
3322 * improvement. But we cannot postpone css_get(to) because if
3323 * the process that has been moved to @to does swap-in, the
3324 * refcount of @to might be decreased to 0.
3326 * We are in attach() phase, so the cgroup is guaranteed to be
3327 * alive, so we can just call css_get().
3335 static inline int mem_cgroup_move_swap_account(swp_entry_t entry
,
3336 struct mem_cgroup
*from
, struct mem_cgroup
*to
)
3342 #ifdef CONFIG_DEBUG_VM
3343 static struct page_cgroup
*lookup_page_cgroup_used(struct page
*page
)
3345 struct page_cgroup
*pc
;
3347 pc
= lookup_page_cgroup(page
);
3349 * Can be NULL while feeding pages into the page allocator for
3350 * the first time, i.e. during boot or memory hotplug;
3351 * or when mem_cgroup_disabled().
3353 if (likely(pc
) && PageCgroupUsed(pc
))
3358 bool mem_cgroup_bad_page_check(struct page
*page
)
3360 if (mem_cgroup_disabled())
3363 return lookup_page_cgroup_used(page
) != NULL
;
3366 void mem_cgroup_print_bad_page(struct page
*page
)
3368 struct page_cgroup
*pc
;
3370 pc
= lookup_page_cgroup_used(page
);
3372 pr_alert("pc:%p pc->flags:%lx pc->mem_cgroup:%p\n",
3373 pc
, pc
->flags
, pc
->mem_cgroup
);
3378 static DEFINE_MUTEX(memcg_limit_mutex
);
3380 static int mem_cgroup_resize_limit(struct mem_cgroup
*memcg
,
3381 unsigned long limit
)
3383 unsigned long curusage
;
3384 unsigned long oldusage
;
3385 bool enlarge
= false;
3390 * For keeping hierarchical_reclaim simple, how long we should retry
3391 * is depends on callers. We set our retry-count to be function
3392 * of # of children which we should visit in this loop.
3394 retry_count
= MEM_CGROUP_RECLAIM_RETRIES
*
3395 mem_cgroup_count_children(memcg
);
3397 oldusage
= page_counter_read(&memcg
->memory
);
3400 if (signal_pending(current
)) {
3405 mutex_lock(&memcg_limit_mutex
);
3406 if (limit
> memcg
->memsw
.limit
) {
3407 mutex_unlock(&memcg_limit_mutex
);
3411 if (limit
> memcg
->memory
.limit
)
3413 ret
= page_counter_limit(&memcg
->memory
, limit
);
3414 mutex_unlock(&memcg_limit_mutex
);
3419 try_to_free_mem_cgroup_pages(memcg
, 1, GFP_KERNEL
, true);
3421 curusage
= page_counter_read(&memcg
->memory
);
3422 /* Usage is reduced ? */
3423 if (curusage
>= oldusage
)
3426 oldusage
= curusage
;
3427 } while (retry_count
);
3429 if (!ret
&& enlarge
)
3430 memcg_oom_recover(memcg
);
3435 static int mem_cgroup_resize_memsw_limit(struct mem_cgroup
*memcg
,
3436 unsigned long limit
)
3438 unsigned long curusage
;
3439 unsigned long oldusage
;
3440 bool enlarge
= false;
3444 /* see mem_cgroup_resize_res_limit */
3445 retry_count
= MEM_CGROUP_RECLAIM_RETRIES
*
3446 mem_cgroup_count_children(memcg
);
3448 oldusage
= page_counter_read(&memcg
->memsw
);
3451 if (signal_pending(current
)) {
3456 mutex_lock(&memcg_limit_mutex
);
3457 if (limit
< memcg
->memory
.limit
) {
3458 mutex_unlock(&memcg_limit_mutex
);
3462 if (limit
> memcg
->memsw
.limit
)
3464 ret
= page_counter_limit(&memcg
->memsw
, limit
);
3465 mutex_unlock(&memcg_limit_mutex
);
3470 try_to_free_mem_cgroup_pages(memcg
, 1, GFP_KERNEL
, false);
3472 curusage
= page_counter_read(&memcg
->memsw
);
3473 /* Usage is reduced ? */
3474 if (curusage
>= oldusage
)
3477 oldusage
= curusage
;
3478 } while (retry_count
);
3480 if (!ret
&& enlarge
)
3481 memcg_oom_recover(memcg
);
3486 unsigned long mem_cgroup_soft_limit_reclaim(struct zone
*zone
, int order
,
3488 unsigned long *total_scanned
)
3490 unsigned long nr_reclaimed
= 0;
3491 struct mem_cgroup_per_zone
*mz
, *next_mz
= NULL
;
3492 unsigned long reclaimed
;
3494 struct mem_cgroup_tree_per_zone
*mctz
;
3495 unsigned long excess
;
3496 unsigned long nr_scanned
;
3501 mctz
= soft_limit_tree_node_zone(zone_to_nid(zone
), zone_idx(zone
));
3503 * This loop can run a while, specially if mem_cgroup's continuously
3504 * keep exceeding their soft limit and putting the system under
3511 mz
= mem_cgroup_largest_soft_limit_node(mctz
);
3516 reclaimed
= mem_cgroup_soft_reclaim(mz
->memcg
, zone
,
3517 gfp_mask
, &nr_scanned
);
3518 nr_reclaimed
+= reclaimed
;
3519 *total_scanned
+= nr_scanned
;
3520 spin_lock_irq(&mctz
->lock
);
3521 __mem_cgroup_remove_exceeded(mz
, mctz
);
3524 * If we failed to reclaim anything from this memory cgroup
3525 * it is time to move on to the next cgroup
3529 next_mz
= __mem_cgroup_largest_soft_limit_node(mctz
);
3531 excess
= soft_limit_excess(mz
->memcg
);
3533 * One school of thought says that we should not add
3534 * back the node to the tree if reclaim returns 0.
3535 * But our reclaim could return 0, simply because due
3536 * to priority we are exposing a smaller subset of
3537 * memory to reclaim from. Consider this as a longer
3540 /* If excess == 0, no tree ops */
3541 __mem_cgroup_insert_exceeded(mz
, mctz
, excess
);
3542 spin_unlock_irq(&mctz
->lock
);
3543 css_put(&mz
->memcg
->css
);
3546 * Could not reclaim anything and there are no more
3547 * mem cgroups to try or we seem to be looping without
3548 * reclaiming anything.
3550 if (!nr_reclaimed
&&
3552 loop
> MEM_CGROUP_MAX_SOFT_LIMIT_RECLAIM_LOOPS
))
3554 } while (!nr_reclaimed
);
3556 css_put(&next_mz
->memcg
->css
);
3557 return nr_reclaimed
;
3561 * Test whether @memcg has children, dead or alive. Note that this
3562 * function doesn't care whether @memcg has use_hierarchy enabled and
3563 * returns %true if there are child csses according to the cgroup
3564 * hierarchy. Testing use_hierarchy is the caller's responsiblity.
3566 static inline bool memcg_has_children(struct mem_cgroup
*memcg
)
3571 * The lock does not prevent addition or deletion of children, but
3572 * it prevents a new child from being initialized based on this
3573 * parent in css_online(), so it's enough to decide whether
3574 * hierarchically inherited attributes can still be changed or not.
3576 lockdep_assert_held(&memcg_create_mutex
);
3579 ret
= css_next_child(NULL
, &memcg
->css
);
3585 * Reclaims as many pages from the given memcg as possible and moves
3586 * the rest to the parent.
3588 * Caller is responsible for holding css reference for memcg.
3590 static int mem_cgroup_force_empty(struct mem_cgroup
*memcg
)
3592 int nr_retries
= MEM_CGROUP_RECLAIM_RETRIES
;
3594 /* we call try-to-free pages for make this cgroup empty */
3595 lru_add_drain_all();
3596 /* try to free all pages in this cgroup */
3597 while (nr_retries
&& page_counter_read(&memcg
->memory
)) {
3600 if (signal_pending(current
))
3603 progress
= try_to_free_mem_cgroup_pages(memcg
, 1,
3607 /* maybe some writeback is necessary */
3608 congestion_wait(BLK_RW_ASYNC
, HZ
/10);
3616 static ssize_t
mem_cgroup_force_empty_write(struct kernfs_open_file
*of
,
3617 char *buf
, size_t nbytes
,
3620 struct mem_cgroup
*memcg
= mem_cgroup_from_css(of_css(of
));
3622 if (mem_cgroup_is_root(memcg
))
3624 return mem_cgroup_force_empty(memcg
) ?: nbytes
;
3627 static u64
mem_cgroup_hierarchy_read(struct cgroup_subsys_state
*css
,
3630 return mem_cgroup_from_css(css
)->use_hierarchy
;
3633 static int mem_cgroup_hierarchy_write(struct cgroup_subsys_state
*css
,
3634 struct cftype
*cft
, u64 val
)
3637 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
3638 struct mem_cgroup
*parent_memcg
= mem_cgroup_from_css(memcg
->css
.parent
);
3640 mutex_lock(&memcg_create_mutex
);
3642 if (memcg
->use_hierarchy
== val
)
3646 * If parent's use_hierarchy is set, we can't make any modifications
3647 * in the child subtrees. If it is unset, then the change can
3648 * occur, provided the current cgroup has no children.
3650 * For the root cgroup, parent_mem is NULL, we allow value to be
3651 * set if there are no children.
3653 if ((!parent_memcg
|| !parent_memcg
->use_hierarchy
) &&
3654 (val
== 1 || val
== 0)) {
3655 if (!memcg_has_children(memcg
))
3656 memcg
->use_hierarchy
= val
;
3663 mutex_unlock(&memcg_create_mutex
);
3668 static unsigned long tree_stat(struct mem_cgroup
*memcg
,
3669 enum mem_cgroup_stat_index idx
)
3671 struct mem_cgroup
*iter
;
3674 /* Per-cpu values can be negative, use a signed accumulator */
3675 for_each_mem_cgroup_tree(iter
, memcg
)
3676 val
+= mem_cgroup_read_stat(iter
, idx
);
3678 if (val
< 0) /* race ? */
3683 static inline u64
mem_cgroup_usage(struct mem_cgroup
*memcg
, bool swap
)
3687 if (mem_cgroup_is_root(memcg
)) {
3688 val
= tree_stat(memcg
, MEM_CGROUP_STAT_CACHE
);
3689 val
+= tree_stat(memcg
, MEM_CGROUP_STAT_RSS
);
3691 val
+= tree_stat(memcg
, MEM_CGROUP_STAT_SWAP
);
3694 val
= page_counter_read(&memcg
->memory
);
3696 val
= page_counter_read(&memcg
->memsw
);
3698 return val
<< PAGE_SHIFT
;
3709 static u64
mem_cgroup_read_u64(struct cgroup_subsys_state
*css
,
3712 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
3713 struct page_counter
*counter
;
3715 switch (MEMFILE_TYPE(cft
->private)) {
3717 counter
= &memcg
->memory
;
3720 counter
= &memcg
->memsw
;
3723 counter
= &memcg
->kmem
;
3729 switch (MEMFILE_ATTR(cft
->private)) {
3731 if (counter
== &memcg
->memory
)
3732 return mem_cgroup_usage(memcg
, false);
3733 if (counter
== &memcg
->memsw
)
3734 return mem_cgroup_usage(memcg
, true);
3735 return (u64
)page_counter_read(counter
) * PAGE_SIZE
;
3737 return (u64
)counter
->limit
* PAGE_SIZE
;
3739 return (u64
)counter
->watermark
* PAGE_SIZE
;
3741 return counter
->failcnt
;
3742 case RES_SOFT_LIMIT
:
3743 return (u64
)memcg
->soft_limit
* PAGE_SIZE
;
3749 #ifdef CONFIG_MEMCG_KMEM
3750 /* should be called with activate_kmem_mutex held */
3751 static int __memcg_activate_kmem(struct mem_cgroup
*memcg
,
3752 unsigned long nr_pages
)
3757 if (memcg_kmem_is_active(memcg
))
3761 * We are going to allocate memory for data shared by all memory
3762 * cgroups so let's stop accounting here.
3764 memcg_stop_kmem_account();
3767 * For simplicity, we won't allow this to be disabled. It also can't
3768 * be changed if the cgroup has children already, or if tasks had
3771 * If tasks join before we set the limit, a person looking at
3772 * kmem.usage_in_bytes will have no way to determine when it took
3773 * place, which makes the value quite meaningless.
3775 * After it first became limited, changes in the value of the limit are
3776 * of course permitted.
3778 mutex_lock(&memcg_create_mutex
);
3779 if (cgroup_has_tasks(memcg
->css
.cgroup
) ||
3780 (memcg
->use_hierarchy
&& memcg_has_children(memcg
)))
3782 mutex_unlock(&memcg_create_mutex
);
3786 memcg_id
= memcg_alloc_cache_id();
3792 memcg
->kmemcg_id
= memcg_id
;
3793 INIT_LIST_HEAD(&memcg
->memcg_slab_caches
);
3796 * We couldn't have accounted to this cgroup, because it hasn't got the
3797 * active bit set yet, so this should succeed.
3799 err
= page_counter_limit(&memcg
->kmem
, nr_pages
);
3802 static_key_slow_inc(&memcg_kmem_enabled_key
);
3804 * Setting the active bit after enabling static branching will
3805 * guarantee no one starts accounting before all call sites are
3808 memcg_kmem_set_active(memcg
);
3810 memcg_resume_kmem_account();
3814 static int memcg_activate_kmem(struct mem_cgroup
*memcg
,
3815 unsigned long nr_pages
)
3819 mutex_lock(&activate_kmem_mutex
);
3820 ret
= __memcg_activate_kmem(memcg
, nr_pages
);
3821 mutex_unlock(&activate_kmem_mutex
);
3825 static int memcg_update_kmem_limit(struct mem_cgroup
*memcg
,
3826 unsigned long limit
)
3830 mutex_lock(&memcg_limit_mutex
);
3831 if (!memcg_kmem_is_active(memcg
))
3832 ret
= memcg_activate_kmem(memcg
, limit
);
3834 ret
= page_counter_limit(&memcg
->kmem
, limit
);
3835 mutex_unlock(&memcg_limit_mutex
);
3839 static int memcg_propagate_kmem(struct mem_cgroup
*memcg
)
3842 struct mem_cgroup
*parent
= parent_mem_cgroup(memcg
);
3847 mutex_lock(&activate_kmem_mutex
);
3849 * If the parent cgroup is not kmem-active now, it cannot be activated
3850 * after this point, because it has at least one child already.
3852 if (memcg_kmem_is_active(parent
))
3853 ret
= __memcg_activate_kmem(memcg
, PAGE_COUNTER_MAX
);
3854 mutex_unlock(&activate_kmem_mutex
);
3858 static int memcg_update_kmem_limit(struct mem_cgroup
*memcg
,
3859 unsigned long limit
)
3863 #endif /* CONFIG_MEMCG_KMEM */
3866 * The user of this function is...
3869 static ssize_t
mem_cgroup_write(struct kernfs_open_file
*of
,
3870 char *buf
, size_t nbytes
, loff_t off
)
3872 struct mem_cgroup
*memcg
= mem_cgroup_from_css(of_css(of
));
3873 unsigned long nr_pages
;
3876 buf
= strstrip(buf
);
3877 ret
= page_counter_memparse(buf
, &nr_pages
);
3881 switch (MEMFILE_ATTR(of_cft(of
)->private)) {
3883 if (mem_cgroup_is_root(memcg
)) { /* Can't set limit on root */
3887 switch (MEMFILE_TYPE(of_cft(of
)->private)) {
3889 ret
= mem_cgroup_resize_limit(memcg
, nr_pages
);
3892 ret
= mem_cgroup_resize_memsw_limit(memcg
, nr_pages
);
3895 ret
= memcg_update_kmem_limit(memcg
, nr_pages
);
3899 case RES_SOFT_LIMIT
:
3900 memcg
->soft_limit
= nr_pages
;
3904 return ret
?: nbytes
;
3907 static ssize_t
mem_cgroup_reset(struct kernfs_open_file
*of
, char *buf
,
3908 size_t nbytes
, loff_t off
)
3910 struct mem_cgroup
*memcg
= mem_cgroup_from_css(of_css(of
));
3911 struct page_counter
*counter
;
3913 switch (MEMFILE_TYPE(of_cft(of
)->private)) {
3915 counter
= &memcg
->memory
;
3918 counter
= &memcg
->memsw
;
3921 counter
= &memcg
->kmem
;
3927 switch (MEMFILE_ATTR(of_cft(of
)->private)) {
3929 page_counter_reset_watermark(counter
);
3932 counter
->failcnt
= 0;
3941 static u64
mem_cgroup_move_charge_read(struct cgroup_subsys_state
*css
,
3944 return mem_cgroup_from_css(css
)->move_charge_at_immigrate
;
3948 static int mem_cgroup_move_charge_write(struct cgroup_subsys_state
*css
,
3949 struct cftype
*cft
, u64 val
)
3951 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
3953 if (val
>= (1 << NR_MOVE_TYPE
))
3957 * No kind of locking is needed in here, because ->can_attach() will
3958 * check this value once in the beginning of the process, and then carry
3959 * on with stale data. This means that changes to this value will only
3960 * affect task migrations starting after the change.
3962 memcg
->move_charge_at_immigrate
= val
;
3966 static int mem_cgroup_move_charge_write(struct cgroup_subsys_state
*css
,
3967 struct cftype
*cft
, u64 val
)
3974 static int memcg_numa_stat_show(struct seq_file
*m
, void *v
)
3978 unsigned int lru_mask
;
3981 static const struct numa_stat stats
[] = {
3982 { "total", LRU_ALL
},
3983 { "file", LRU_ALL_FILE
},
3984 { "anon", LRU_ALL_ANON
},
3985 { "unevictable", BIT(LRU_UNEVICTABLE
) },
3987 const struct numa_stat
*stat
;
3990 struct mem_cgroup
*memcg
= mem_cgroup_from_css(seq_css(m
));
3992 for (stat
= stats
; stat
< stats
+ ARRAY_SIZE(stats
); stat
++) {
3993 nr
= mem_cgroup_nr_lru_pages(memcg
, stat
->lru_mask
);
3994 seq_printf(m
, "%s=%lu", stat
->name
, nr
);
3995 for_each_node_state(nid
, N_MEMORY
) {
3996 nr
= mem_cgroup_node_nr_lru_pages(memcg
, nid
,
3998 seq_printf(m
, " N%d=%lu", nid
, nr
);
4003 for (stat
= stats
; stat
< stats
+ ARRAY_SIZE(stats
); stat
++) {
4004 struct mem_cgroup
*iter
;
4007 for_each_mem_cgroup_tree(iter
, memcg
)
4008 nr
+= mem_cgroup_nr_lru_pages(iter
, stat
->lru_mask
);
4009 seq_printf(m
, "hierarchical_%s=%lu", stat
->name
, nr
);
4010 for_each_node_state(nid
, N_MEMORY
) {
4012 for_each_mem_cgroup_tree(iter
, memcg
)
4013 nr
+= mem_cgroup_node_nr_lru_pages(
4014 iter
, nid
, stat
->lru_mask
);
4015 seq_printf(m
, " N%d=%lu", nid
, nr
);
4022 #endif /* CONFIG_NUMA */
4024 static inline void mem_cgroup_lru_names_not_uptodate(void)
4026 BUILD_BUG_ON(ARRAY_SIZE(mem_cgroup_lru_names
) != NR_LRU_LISTS
);
4029 static int memcg_stat_show(struct seq_file
*m
, void *v
)
4031 struct mem_cgroup
*memcg
= mem_cgroup_from_css(seq_css(m
));
4032 unsigned long memory
, memsw
;
4033 struct mem_cgroup
*mi
;
4036 for (i
= 0; i
< MEM_CGROUP_STAT_NSTATS
; i
++) {
4037 if (i
== MEM_CGROUP_STAT_SWAP
&& !do_swap_account
)
4039 seq_printf(m
, "%s %ld\n", mem_cgroup_stat_names
[i
],
4040 mem_cgroup_read_stat(memcg
, i
) * PAGE_SIZE
);
4043 for (i
= 0; i
< MEM_CGROUP_EVENTS_NSTATS
; i
++)
4044 seq_printf(m
, "%s %lu\n", mem_cgroup_events_names
[i
],
4045 mem_cgroup_read_events(memcg
, i
));
4047 for (i
= 0; i
< NR_LRU_LISTS
; i
++)
4048 seq_printf(m
, "%s %lu\n", mem_cgroup_lru_names
[i
],
4049 mem_cgroup_nr_lru_pages(memcg
, BIT(i
)) * PAGE_SIZE
);
4051 /* Hierarchical information */
4052 memory
= memsw
= PAGE_COUNTER_MAX
;
4053 for (mi
= memcg
; mi
; mi
= parent_mem_cgroup(mi
)) {
4054 memory
= min(memory
, mi
->memory
.limit
);
4055 memsw
= min(memsw
, mi
->memsw
.limit
);
4057 seq_printf(m
, "hierarchical_memory_limit %llu\n",
4058 (u64
)memory
* PAGE_SIZE
);
4059 if (do_swap_account
)
4060 seq_printf(m
, "hierarchical_memsw_limit %llu\n",
4061 (u64
)memsw
* PAGE_SIZE
);
4063 for (i
= 0; i
< MEM_CGROUP_STAT_NSTATS
; i
++) {
4066 if (i
== MEM_CGROUP_STAT_SWAP
&& !do_swap_account
)
4068 for_each_mem_cgroup_tree(mi
, memcg
)
4069 val
+= mem_cgroup_read_stat(mi
, i
) * PAGE_SIZE
;
4070 seq_printf(m
, "total_%s %lld\n", mem_cgroup_stat_names
[i
], val
);
4073 for (i
= 0; i
< MEM_CGROUP_EVENTS_NSTATS
; i
++) {
4074 unsigned long long val
= 0;
4076 for_each_mem_cgroup_tree(mi
, memcg
)
4077 val
+= mem_cgroup_read_events(mi
, i
);
4078 seq_printf(m
, "total_%s %llu\n",
4079 mem_cgroup_events_names
[i
], val
);
4082 for (i
= 0; i
< NR_LRU_LISTS
; i
++) {
4083 unsigned long long val
= 0;
4085 for_each_mem_cgroup_tree(mi
, memcg
)
4086 val
+= mem_cgroup_nr_lru_pages(mi
, BIT(i
)) * PAGE_SIZE
;
4087 seq_printf(m
, "total_%s %llu\n", mem_cgroup_lru_names
[i
], val
);
4090 #ifdef CONFIG_DEBUG_VM
4093 struct mem_cgroup_per_zone
*mz
;
4094 struct zone_reclaim_stat
*rstat
;
4095 unsigned long recent_rotated
[2] = {0, 0};
4096 unsigned long recent_scanned
[2] = {0, 0};
4098 for_each_online_node(nid
)
4099 for (zid
= 0; zid
< MAX_NR_ZONES
; zid
++) {
4100 mz
= &memcg
->nodeinfo
[nid
]->zoneinfo
[zid
];
4101 rstat
= &mz
->lruvec
.reclaim_stat
;
4103 recent_rotated
[0] += rstat
->recent_rotated
[0];
4104 recent_rotated
[1] += rstat
->recent_rotated
[1];
4105 recent_scanned
[0] += rstat
->recent_scanned
[0];
4106 recent_scanned
[1] += rstat
->recent_scanned
[1];
4108 seq_printf(m
, "recent_rotated_anon %lu\n", recent_rotated
[0]);
4109 seq_printf(m
, "recent_rotated_file %lu\n", recent_rotated
[1]);
4110 seq_printf(m
, "recent_scanned_anon %lu\n", recent_scanned
[0]);
4111 seq_printf(m
, "recent_scanned_file %lu\n", recent_scanned
[1]);
4118 static u64
mem_cgroup_swappiness_read(struct cgroup_subsys_state
*css
,
4121 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
4123 return mem_cgroup_swappiness(memcg
);
4126 static int mem_cgroup_swappiness_write(struct cgroup_subsys_state
*css
,
4127 struct cftype
*cft
, u64 val
)
4129 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
4135 memcg
->swappiness
= val
;
4137 vm_swappiness
= val
;
4142 static void __mem_cgroup_threshold(struct mem_cgroup
*memcg
, bool swap
)
4144 struct mem_cgroup_threshold_ary
*t
;
4145 unsigned long usage
;
4150 t
= rcu_dereference(memcg
->thresholds
.primary
);
4152 t
= rcu_dereference(memcg
->memsw_thresholds
.primary
);
4157 usage
= mem_cgroup_usage(memcg
, swap
);
4160 * current_threshold points to threshold just below or equal to usage.
4161 * If it's not true, a threshold was crossed after last
4162 * call of __mem_cgroup_threshold().
4164 i
= t
->current_threshold
;
4167 * Iterate backward over array of thresholds starting from
4168 * current_threshold and check if a threshold is crossed.
4169 * If none of thresholds below usage is crossed, we read
4170 * only one element of the array here.
4172 for (; i
>= 0 && unlikely(t
->entries
[i
].threshold
> usage
); i
--)
4173 eventfd_signal(t
->entries
[i
].eventfd
, 1);
4175 /* i = current_threshold + 1 */
4179 * Iterate forward over array of thresholds starting from
4180 * current_threshold+1 and check if a threshold is crossed.
4181 * If none of thresholds above usage is crossed, we read
4182 * only one element of the array here.
4184 for (; i
< t
->size
&& unlikely(t
->entries
[i
].threshold
<= usage
); i
++)
4185 eventfd_signal(t
->entries
[i
].eventfd
, 1);
4187 /* Update current_threshold */
4188 t
->current_threshold
= i
- 1;
4193 static void mem_cgroup_threshold(struct mem_cgroup
*memcg
)
4196 __mem_cgroup_threshold(memcg
, false);
4197 if (do_swap_account
)
4198 __mem_cgroup_threshold(memcg
, true);
4200 memcg
= parent_mem_cgroup(memcg
);
4204 static int compare_thresholds(const void *a
, const void *b
)
4206 const struct mem_cgroup_threshold
*_a
= a
;
4207 const struct mem_cgroup_threshold
*_b
= b
;
4209 if (_a
->threshold
> _b
->threshold
)
4212 if (_a
->threshold
< _b
->threshold
)
4218 static int mem_cgroup_oom_notify_cb(struct mem_cgroup
*memcg
)
4220 struct mem_cgroup_eventfd_list
*ev
;
4222 spin_lock(&memcg_oom_lock
);
4224 list_for_each_entry(ev
, &memcg
->oom_notify
, list
)
4225 eventfd_signal(ev
->eventfd
, 1);
4227 spin_unlock(&memcg_oom_lock
);
4231 static void mem_cgroup_oom_notify(struct mem_cgroup
*memcg
)
4233 struct mem_cgroup
*iter
;
4235 for_each_mem_cgroup_tree(iter
, memcg
)
4236 mem_cgroup_oom_notify_cb(iter
);
4239 static int __mem_cgroup_usage_register_event(struct mem_cgroup
*memcg
,
4240 struct eventfd_ctx
*eventfd
, const char *args
, enum res_type type
)
4242 struct mem_cgroup_thresholds
*thresholds
;
4243 struct mem_cgroup_threshold_ary
*new;
4244 unsigned long threshold
;
4245 unsigned long usage
;
4248 ret
= page_counter_memparse(args
, &threshold
);
4252 mutex_lock(&memcg
->thresholds_lock
);
4255 thresholds
= &memcg
->thresholds
;
4256 usage
= mem_cgroup_usage(memcg
, false);
4257 } else if (type
== _MEMSWAP
) {
4258 thresholds
= &memcg
->memsw_thresholds
;
4259 usage
= mem_cgroup_usage(memcg
, true);
4263 /* Check if a threshold crossed before adding a new one */
4264 if (thresholds
->primary
)
4265 __mem_cgroup_threshold(memcg
, type
== _MEMSWAP
);
4267 size
= thresholds
->primary
? thresholds
->primary
->size
+ 1 : 1;
4269 /* Allocate memory for new array of thresholds */
4270 new = kmalloc(sizeof(*new) + size
* sizeof(struct mem_cgroup_threshold
),
4278 /* Copy thresholds (if any) to new array */
4279 if (thresholds
->primary
) {
4280 memcpy(new->entries
, thresholds
->primary
->entries
, (size
- 1) *
4281 sizeof(struct mem_cgroup_threshold
));
4284 /* Add new threshold */
4285 new->entries
[size
- 1].eventfd
= eventfd
;
4286 new->entries
[size
- 1].threshold
= threshold
;
4288 /* Sort thresholds. Registering of new threshold isn't time-critical */
4289 sort(new->entries
, size
, sizeof(struct mem_cgroup_threshold
),
4290 compare_thresholds
, NULL
);
4292 /* Find current threshold */
4293 new->current_threshold
= -1;
4294 for (i
= 0; i
< size
; i
++) {
4295 if (new->entries
[i
].threshold
<= usage
) {
4297 * new->current_threshold will not be used until
4298 * rcu_assign_pointer(), so it's safe to increment
4301 ++new->current_threshold
;
4306 /* Free old spare buffer and save old primary buffer as spare */
4307 kfree(thresholds
->spare
);
4308 thresholds
->spare
= thresholds
->primary
;
4310 rcu_assign_pointer(thresholds
->primary
, new);
4312 /* To be sure that nobody uses thresholds */
4316 mutex_unlock(&memcg
->thresholds_lock
);
4321 static int mem_cgroup_usage_register_event(struct mem_cgroup
*memcg
,
4322 struct eventfd_ctx
*eventfd
, const char *args
)
4324 return __mem_cgroup_usage_register_event(memcg
, eventfd
, args
, _MEM
);
4327 static int memsw_cgroup_usage_register_event(struct mem_cgroup
*memcg
,
4328 struct eventfd_ctx
*eventfd
, const char *args
)
4330 return __mem_cgroup_usage_register_event(memcg
, eventfd
, args
, _MEMSWAP
);
4333 static void __mem_cgroup_usage_unregister_event(struct mem_cgroup
*memcg
,
4334 struct eventfd_ctx
*eventfd
, enum res_type type
)
4336 struct mem_cgroup_thresholds
*thresholds
;
4337 struct mem_cgroup_threshold_ary
*new;
4338 unsigned long usage
;
4341 mutex_lock(&memcg
->thresholds_lock
);
4344 thresholds
= &memcg
->thresholds
;
4345 usage
= mem_cgroup_usage(memcg
, false);
4346 } else if (type
== _MEMSWAP
) {
4347 thresholds
= &memcg
->memsw_thresholds
;
4348 usage
= mem_cgroup_usage(memcg
, true);
4352 if (!thresholds
->primary
)
4355 /* Check if a threshold crossed before removing */
4356 __mem_cgroup_threshold(memcg
, type
== _MEMSWAP
);
4358 /* Calculate new number of threshold */
4360 for (i
= 0; i
< thresholds
->primary
->size
; i
++) {
4361 if (thresholds
->primary
->entries
[i
].eventfd
!= eventfd
)
4365 new = thresholds
->spare
;
4367 /* Set thresholds array to NULL if we don't have thresholds */
4376 /* Copy thresholds and find current threshold */
4377 new->current_threshold
= -1;
4378 for (i
= 0, j
= 0; i
< thresholds
->primary
->size
; i
++) {
4379 if (thresholds
->primary
->entries
[i
].eventfd
== eventfd
)
4382 new->entries
[j
] = thresholds
->primary
->entries
[i
];
4383 if (new->entries
[j
].threshold
<= usage
) {
4385 * new->current_threshold will not be used
4386 * until rcu_assign_pointer(), so it's safe to increment
4389 ++new->current_threshold
;
4395 /* Swap primary and spare array */
4396 thresholds
->spare
= thresholds
->primary
;
4397 /* If all events are unregistered, free the spare array */
4399 kfree(thresholds
->spare
);
4400 thresholds
->spare
= NULL
;
4403 rcu_assign_pointer(thresholds
->primary
, new);
4405 /* To be sure that nobody uses thresholds */
4408 mutex_unlock(&memcg
->thresholds_lock
);
4411 static void mem_cgroup_usage_unregister_event(struct mem_cgroup
*memcg
,
4412 struct eventfd_ctx
*eventfd
)
4414 return __mem_cgroup_usage_unregister_event(memcg
, eventfd
, _MEM
);
4417 static void memsw_cgroup_usage_unregister_event(struct mem_cgroup
*memcg
,
4418 struct eventfd_ctx
*eventfd
)
4420 return __mem_cgroup_usage_unregister_event(memcg
, eventfd
, _MEMSWAP
);
4423 static int mem_cgroup_oom_register_event(struct mem_cgroup
*memcg
,
4424 struct eventfd_ctx
*eventfd
, const char *args
)
4426 struct mem_cgroup_eventfd_list
*event
;
4428 event
= kmalloc(sizeof(*event
), GFP_KERNEL
);
4432 spin_lock(&memcg_oom_lock
);
4434 event
->eventfd
= eventfd
;
4435 list_add(&event
->list
, &memcg
->oom_notify
);
4437 /* already in OOM ? */
4438 if (atomic_read(&memcg
->under_oom
))
4439 eventfd_signal(eventfd
, 1);
4440 spin_unlock(&memcg_oom_lock
);
4445 static void mem_cgroup_oom_unregister_event(struct mem_cgroup
*memcg
,
4446 struct eventfd_ctx
*eventfd
)
4448 struct mem_cgroup_eventfd_list
*ev
, *tmp
;
4450 spin_lock(&memcg_oom_lock
);
4452 list_for_each_entry_safe(ev
, tmp
, &memcg
->oom_notify
, list
) {
4453 if (ev
->eventfd
== eventfd
) {
4454 list_del(&ev
->list
);
4459 spin_unlock(&memcg_oom_lock
);
4462 static int mem_cgroup_oom_control_read(struct seq_file
*sf
, void *v
)
4464 struct mem_cgroup
*memcg
= mem_cgroup_from_css(seq_css(sf
));
4466 seq_printf(sf
, "oom_kill_disable %d\n", memcg
->oom_kill_disable
);
4467 seq_printf(sf
, "under_oom %d\n", (bool)atomic_read(&memcg
->under_oom
));
4471 static int mem_cgroup_oom_control_write(struct cgroup_subsys_state
*css
,
4472 struct cftype
*cft
, u64 val
)
4474 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
4476 /* cannot set to root cgroup and only 0 and 1 are allowed */
4477 if (!css
->parent
|| !((val
== 0) || (val
== 1)))
4480 memcg
->oom_kill_disable
= val
;
4482 memcg_oom_recover(memcg
);
4487 #ifdef CONFIG_MEMCG_KMEM
4488 static int memcg_init_kmem(struct mem_cgroup
*memcg
, struct cgroup_subsys
*ss
)
4492 memcg
->kmemcg_id
= -1;
4493 ret
= memcg_propagate_kmem(memcg
);
4497 return mem_cgroup_sockets_init(memcg
, ss
);
4500 static void memcg_destroy_kmem(struct mem_cgroup
*memcg
)
4502 mem_cgroup_sockets_destroy(memcg
);
4505 static int memcg_init_kmem(struct mem_cgroup
*memcg
, struct cgroup_subsys
*ss
)
4510 static void memcg_destroy_kmem(struct mem_cgroup
*memcg
)
4516 * DO NOT USE IN NEW FILES.
4518 * "cgroup.event_control" implementation.
4520 * This is way over-engineered. It tries to support fully configurable
4521 * events for each user. Such level of flexibility is completely
4522 * unnecessary especially in the light of the planned unified hierarchy.
4524 * Please deprecate this and replace with something simpler if at all
4529 * Unregister event and free resources.
4531 * Gets called from workqueue.
4533 static void memcg_event_remove(struct work_struct
*work
)
4535 struct mem_cgroup_event
*event
=
4536 container_of(work
, struct mem_cgroup_event
, remove
);
4537 struct mem_cgroup
*memcg
= event
->memcg
;
4539 remove_wait_queue(event
->wqh
, &event
->wait
);
4541 event
->unregister_event(memcg
, event
->eventfd
);
4543 /* Notify userspace the event is going away. */
4544 eventfd_signal(event
->eventfd
, 1);
4546 eventfd_ctx_put(event
->eventfd
);
4548 css_put(&memcg
->css
);
4552 * Gets called on POLLHUP on eventfd when user closes it.
4554 * Called with wqh->lock held and interrupts disabled.
4556 static int memcg_event_wake(wait_queue_t
*wait
, unsigned mode
,
4557 int sync
, void *key
)
4559 struct mem_cgroup_event
*event
=
4560 container_of(wait
, struct mem_cgroup_event
, wait
);
4561 struct mem_cgroup
*memcg
= event
->memcg
;
4562 unsigned long flags
= (unsigned long)key
;
4564 if (flags
& POLLHUP
) {
4566 * If the event has been detached at cgroup removal, we
4567 * can simply return knowing the other side will cleanup
4570 * We can't race against event freeing since the other
4571 * side will require wqh->lock via remove_wait_queue(),
4574 spin_lock(&memcg
->event_list_lock
);
4575 if (!list_empty(&event
->list
)) {
4576 list_del_init(&event
->list
);
4578 * We are in atomic context, but cgroup_event_remove()
4579 * may sleep, so we have to call it in workqueue.
4581 schedule_work(&event
->remove
);
4583 spin_unlock(&memcg
->event_list_lock
);
4589 static void memcg_event_ptable_queue_proc(struct file
*file
,
4590 wait_queue_head_t
*wqh
, poll_table
*pt
)
4592 struct mem_cgroup_event
*event
=
4593 container_of(pt
, struct mem_cgroup_event
, pt
);
4596 add_wait_queue(wqh
, &event
->wait
);
4600 * DO NOT USE IN NEW FILES.
4602 * Parse input and register new cgroup event handler.
4604 * Input must be in format '<event_fd> <control_fd> <args>'.
4605 * Interpretation of args is defined by control file implementation.
4607 static ssize_t
memcg_write_event_control(struct kernfs_open_file
*of
,
4608 char *buf
, size_t nbytes
, loff_t off
)
4610 struct cgroup_subsys_state
*css
= of_css(of
);
4611 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
4612 struct mem_cgroup_event
*event
;
4613 struct cgroup_subsys_state
*cfile_css
;
4614 unsigned int efd
, cfd
;
4621 buf
= strstrip(buf
);
4623 efd
= simple_strtoul(buf
, &endp
, 10);
4628 cfd
= simple_strtoul(buf
, &endp
, 10);
4629 if ((*endp
!= ' ') && (*endp
!= '\0'))
4633 event
= kzalloc(sizeof(*event
), GFP_KERNEL
);
4637 event
->memcg
= memcg
;
4638 INIT_LIST_HEAD(&event
->list
);
4639 init_poll_funcptr(&event
->pt
, memcg_event_ptable_queue_proc
);
4640 init_waitqueue_func_entry(&event
->wait
, memcg_event_wake
);
4641 INIT_WORK(&event
->remove
, memcg_event_remove
);
4649 event
->eventfd
= eventfd_ctx_fileget(efile
.file
);
4650 if (IS_ERR(event
->eventfd
)) {
4651 ret
= PTR_ERR(event
->eventfd
);
4658 goto out_put_eventfd
;
4661 /* the process need read permission on control file */
4662 /* AV: shouldn't we check that it's been opened for read instead? */
4663 ret
= inode_permission(file_inode(cfile
.file
), MAY_READ
);
4668 * Determine the event callbacks and set them in @event. This used
4669 * to be done via struct cftype but cgroup core no longer knows
4670 * about these events. The following is crude but the whole thing
4671 * is for compatibility anyway.
4673 * DO NOT ADD NEW FILES.
4675 name
= cfile
.file
->f_dentry
->d_name
.name
;
4677 if (!strcmp(name
, "memory.usage_in_bytes")) {
4678 event
->register_event
= mem_cgroup_usage_register_event
;
4679 event
->unregister_event
= mem_cgroup_usage_unregister_event
;
4680 } else if (!strcmp(name
, "memory.oom_control")) {
4681 event
->register_event
= mem_cgroup_oom_register_event
;
4682 event
->unregister_event
= mem_cgroup_oom_unregister_event
;
4683 } else if (!strcmp(name
, "memory.pressure_level")) {
4684 event
->register_event
= vmpressure_register_event
;
4685 event
->unregister_event
= vmpressure_unregister_event
;
4686 } else if (!strcmp(name
, "memory.memsw.usage_in_bytes")) {
4687 event
->register_event
= memsw_cgroup_usage_register_event
;
4688 event
->unregister_event
= memsw_cgroup_usage_unregister_event
;
4695 * Verify @cfile should belong to @css. Also, remaining events are
4696 * automatically removed on cgroup destruction but the removal is
4697 * asynchronous, so take an extra ref on @css.
4699 cfile_css
= css_tryget_online_from_dir(cfile
.file
->f_dentry
->d_parent
,
4700 &memory_cgrp_subsys
);
4702 if (IS_ERR(cfile_css
))
4704 if (cfile_css
!= css
) {
4709 ret
= event
->register_event(memcg
, event
->eventfd
, buf
);
4713 efile
.file
->f_op
->poll(efile
.file
, &event
->pt
);
4715 spin_lock(&memcg
->event_list_lock
);
4716 list_add(&event
->list
, &memcg
->event_list
);
4717 spin_unlock(&memcg
->event_list_lock
);
4729 eventfd_ctx_put(event
->eventfd
);
4738 static struct cftype mem_cgroup_files
[] = {
4740 .name
= "usage_in_bytes",
4741 .private = MEMFILE_PRIVATE(_MEM
, RES_USAGE
),
4742 .read_u64
= mem_cgroup_read_u64
,
4745 .name
= "max_usage_in_bytes",
4746 .private = MEMFILE_PRIVATE(_MEM
, RES_MAX_USAGE
),
4747 .write
= mem_cgroup_reset
,
4748 .read_u64
= mem_cgroup_read_u64
,
4751 .name
= "limit_in_bytes",
4752 .private = MEMFILE_PRIVATE(_MEM
, RES_LIMIT
),
4753 .write
= mem_cgroup_write
,
4754 .read_u64
= mem_cgroup_read_u64
,
4757 .name
= "soft_limit_in_bytes",
4758 .private = MEMFILE_PRIVATE(_MEM
, RES_SOFT_LIMIT
),
4759 .write
= mem_cgroup_write
,
4760 .read_u64
= mem_cgroup_read_u64
,
4764 .private = MEMFILE_PRIVATE(_MEM
, RES_FAILCNT
),
4765 .write
= mem_cgroup_reset
,
4766 .read_u64
= mem_cgroup_read_u64
,
4770 .seq_show
= memcg_stat_show
,
4773 .name
= "force_empty",
4774 .write
= mem_cgroup_force_empty_write
,
4777 .name
= "use_hierarchy",
4778 .write_u64
= mem_cgroup_hierarchy_write
,
4779 .read_u64
= mem_cgroup_hierarchy_read
,
4782 .name
= "cgroup.event_control", /* XXX: for compat */
4783 .write
= memcg_write_event_control
,
4784 .flags
= CFTYPE_NO_PREFIX
,
4788 .name
= "swappiness",
4789 .read_u64
= mem_cgroup_swappiness_read
,
4790 .write_u64
= mem_cgroup_swappiness_write
,
4793 .name
= "move_charge_at_immigrate",
4794 .read_u64
= mem_cgroup_move_charge_read
,
4795 .write_u64
= mem_cgroup_move_charge_write
,
4798 .name
= "oom_control",
4799 .seq_show
= mem_cgroup_oom_control_read
,
4800 .write_u64
= mem_cgroup_oom_control_write
,
4801 .private = MEMFILE_PRIVATE(_OOM_TYPE
, OOM_CONTROL
),
4804 .name
= "pressure_level",
4808 .name
= "numa_stat",
4809 .seq_show
= memcg_numa_stat_show
,
4812 #ifdef CONFIG_MEMCG_KMEM
4814 .name
= "kmem.limit_in_bytes",
4815 .private = MEMFILE_PRIVATE(_KMEM
, RES_LIMIT
),
4816 .write
= mem_cgroup_write
,
4817 .read_u64
= mem_cgroup_read_u64
,
4820 .name
= "kmem.usage_in_bytes",
4821 .private = MEMFILE_PRIVATE(_KMEM
, RES_USAGE
),
4822 .read_u64
= mem_cgroup_read_u64
,
4825 .name
= "kmem.failcnt",
4826 .private = MEMFILE_PRIVATE(_KMEM
, RES_FAILCNT
),
4827 .write
= mem_cgroup_reset
,
4828 .read_u64
= mem_cgroup_read_u64
,
4831 .name
= "kmem.max_usage_in_bytes",
4832 .private = MEMFILE_PRIVATE(_KMEM
, RES_MAX_USAGE
),
4833 .write
= mem_cgroup_reset
,
4834 .read_u64
= mem_cgroup_read_u64
,
4836 #ifdef CONFIG_SLABINFO
4838 .name
= "kmem.slabinfo",
4839 .seq_show
= mem_cgroup_slabinfo_read
,
4843 { }, /* terminate */
4846 #ifdef CONFIG_MEMCG_SWAP
4847 static struct cftype memsw_cgroup_files
[] = {
4849 .name
= "memsw.usage_in_bytes",
4850 .private = MEMFILE_PRIVATE(_MEMSWAP
, RES_USAGE
),
4851 .read_u64
= mem_cgroup_read_u64
,
4854 .name
= "memsw.max_usage_in_bytes",
4855 .private = MEMFILE_PRIVATE(_MEMSWAP
, RES_MAX_USAGE
),
4856 .write
= mem_cgroup_reset
,
4857 .read_u64
= mem_cgroup_read_u64
,
4860 .name
= "memsw.limit_in_bytes",
4861 .private = MEMFILE_PRIVATE(_MEMSWAP
, RES_LIMIT
),
4862 .write
= mem_cgroup_write
,
4863 .read_u64
= mem_cgroup_read_u64
,
4866 .name
= "memsw.failcnt",
4867 .private = MEMFILE_PRIVATE(_MEMSWAP
, RES_FAILCNT
),
4868 .write
= mem_cgroup_reset
,
4869 .read_u64
= mem_cgroup_read_u64
,
4871 { }, /* terminate */
4874 static int alloc_mem_cgroup_per_zone_info(struct mem_cgroup
*memcg
, int node
)
4876 struct mem_cgroup_per_node
*pn
;
4877 struct mem_cgroup_per_zone
*mz
;
4878 int zone
, tmp
= node
;
4880 * This routine is called against possible nodes.
4881 * But it's BUG to call kmalloc() against offline node.
4883 * TODO: this routine can waste much memory for nodes which will
4884 * never be onlined. It's better to use memory hotplug callback
4887 if (!node_state(node
, N_NORMAL_MEMORY
))
4889 pn
= kzalloc_node(sizeof(*pn
), GFP_KERNEL
, tmp
);
4893 for (zone
= 0; zone
< MAX_NR_ZONES
; zone
++) {
4894 mz
= &pn
->zoneinfo
[zone
];
4895 lruvec_init(&mz
->lruvec
);
4896 mz
->usage_in_excess
= 0;
4897 mz
->on_tree
= false;
4900 memcg
->nodeinfo
[node
] = pn
;
4904 static void free_mem_cgroup_per_zone_info(struct mem_cgroup
*memcg
, int node
)
4906 kfree(memcg
->nodeinfo
[node
]);
4909 static struct mem_cgroup
*mem_cgroup_alloc(void)
4911 struct mem_cgroup
*memcg
;
4914 size
= sizeof(struct mem_cgroup
);
4915 size
+= nr_node_ids
* sizeof(struct mem_cgroup_per_node
*);
4917 memcg
= kzalloc(size
, GFP_KERNEL
);
4921 memcg
->stat
= alloc_percpu(struct mem_cgroup_stat_cpu
);
4924 spin_lock_init(&memcg
->pcp_counter_lock
);
4933 * At destroying mem_cgroup, references from swap_cgroup can remain.
4934 * (scanning all at force_empty is too costly...)
4936 * Instead of clearing all references at force_empty, we remember
4937 * the number of reference from swap_cgroup and free mem_cgroup when
4938 * it goes down to 0.
4940 * Removal of cgroup itself succeeds regardless of refs from swap.
4943 static void __mem_cgroup_free(struct mem_cgroup
*memcg
)
4947 mem_cgroup_remove_from_trees(memcg
);
4950 free_mem_cgroup_per_zone_info(memcg
, node
);
4952 free_percpu(memcg
->stat
);
4955 * We need to make sure that (at least for now), the jump label
4956 * destruction code runs outside of the cgroup lock. This is because
4957 * get_online_cpus(), which is called from the static_branch update,
4958 * can't be called inside the cgroup_lock. cpusets are the ones
4959 * enforcing this dependency, so if they ever change, we might as well.
4961 * schedule_work() will guarantee this happens. Be careful if you need
4962 * to move this code around, and make sure it is outside
4965 disarm_static_keys(memcg
);
4970 * Returns the parent mem_cgroup in memcgroup hierarchy with hierarchy enabled.
4972 struct mem_cgroup
*parent_mem_cgroup(struct mem_cgroup
*memcg
)
4974 if (!memcg
->memory
.parent
)
4976 return mem_cgroup_from_counter(memcg
->memory
.parent
, memory
);
4978 EXPORT_SYMBOL(parent_mem_cgroup
);
4980 static void __init
mem_cgroup_soft_limit_tree_init(void)
4982 struct mem_cgroup_tree_per_node
*rtpn
;
4983 struct mem_cgroup_tree_per_zone
*rtpz
;
4984 int tmp
, node
, zone
;
4986 for_each_node(node
) {
4988 if (!node_state(node
, N_NORMAL_MEMORY
))
4990 rtpn
= kzalloc_node(sizeof(*rtpn
), GFP_KERNEL
, tmp
);
4993 soft_limit_tree
.rb_tree_per_node
[node
] = rtpn
;
4995 for (zone
= 0; zone
< MAX_NR_ZONES
; zone
++) {
4996 rtpz
= &rtpn
->rb_tree_per_zone
[zone
];
4997 rtpz
->rb_root
= RB_ROOT
;
4998 spin_lock_init(&rtpz
->lock
);
5003 static struct cgroup_subsys_state
* __ref
5004 mem_cgroup_css_alloc(struct cgroup_subsys_state
*parent_css
)
5006 struct mem_cgroup
*memcg
;
5007 long error
= -ENOMEM
;
5010 memcg
= mem_cgroup_alloc();
5012 return ERR_PTR(error
);
5015 if (alloc_mem_cgroup_per_zone_info(memcg
, node
))
5019 if (parent_css
== NULL
) {
5020 root_mem_cgroup
= memcg
;
5021 page_counter_init(&memcg
->memory
, NULL
);
5022 page_counter_init(&memcg
->memsw
, NULL
);
5023 page_counter_init(&memcg
->kmem
, NULL
);
5026 memcg
->last_scanned_node
= MAX_NUMNODES
;
5027 INIT_LIST_HEAD(&memcg
->oom_notify
);
5028 memcg
->move_charge_at_immigrate
= 0;
5029 mutex_init(&memcg
->thresholds_lock
);
5030 spin_lock_init(&memcg
->move_lock
);
5031 vmpressure_init(&memcg
->vmpressure
);
5032 INIT_LIST_HEAD(&memcg
->event_list
);
5033 spin_lock_init(&memcg
->event_list_lock
);
5038 __mem_cgroup_free(memcg
);
5039 return ERR_PTR(error
);
5043 mem_cgroup_css_online(struct cgroup_subsys_state
*css
)
5045 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
5046 struct mem_cgroup
*parent
= mem_cgroup_from_css(css
->parent
);
5049 if (css
->id
> MEM_CGROUP_ID_MAX
)
5055 mutex_lock(&memcg_create_mutex
);
5057 memcg
->use_hierarchy
= parent
->use_hierarchy
;
5058 memcg
->oom_kill_disable
= parent
->oom_kill_disable
;
5059 memcg
->swappiness
= mem_cgroup_swappiness(parent
);
5061 if (parent
->use_hierarchy
) {
5062 page_counter_init(&memcg
->memory
, &parent
->memory
);
5063 page_counter_init(&memcg
->memsw
, &parent
->memsw
);
5064 page_counter_init(&memcg
->kmem
, &parent
->kmem
);
5067 * No need to take a reference to the parent because cgroup
5068 * core guarantees its existence.
5071 page_counter_init(&memcg
->memory
, NULL
);
5072 page_counter_init(&memcg
->memsw
, NULL
);
5073 page_counter_init(&memcg
->kmem
, NULL
);
5075 * Deeper hierachy with use_hierarchy == false doesn't make
5076 * much sense so let cgroup subsystem know about this
5077 * unfortunate state in our controller.
5079 if (parent
!= root_mem_cgroup
)
5080 memory_cgrp_subsys
.broken_hierarchy
= true;
5082 mutex_unlock(&memcg_create_mutex
);
5084 ret
= memcg_init_kmem(memcg
, &memory_cgrp_subsys
);
5089 * Make sure the memcg is initialized: mem_cgroup_iter()
5090 * orders reading memcg->initialized against its callers
5091 * reading the memcg members.
5093 smp_store_release(&memcg
->initialized
, 1);
5098 static void mem_cgroup_css_offline(struct cgroup_subsys_state
*css
)
5100 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
5101 struct mem_cgroup_event
*event
, *tmp
;
5104 * Unregister events and notify userspace.
5105 * Notify userspace about cgroup removing only after rmdir of cgroup
5106 * directory to avoid race between userspace and kernelspace.
5108 spin_lock(&memcg
->event_list_lock
);
5109 list_for_each_entry_safe(event
, tmp
, &memcg
->event_list
, list
) {
5110 list_del_init(&event
->list
);
5111 schedule_work(&event
->remove
);
5113 spin_unlock(&memcg
->event_list_lock
);
5115 memcg_unregister_all_caches(memcg
);
5116 vmpressure_cleanup(&memcg
->vmpressure
);
5119 static void mem_cgroup_css_free(struct cgroup_subsys_state
*css
)
5121 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
5123 memcg_destroy_kmem(memcg
);
5124 __mem_cgroup_free(memcg
);
5128 * mem_cgroup_css_reset - reset the states of a mem_cgroup
5129 * @css: the target css
5131 * Reset the states of the mem_cgroup associated with @css. This is
5132 * invoked when the userland requests disabling on the default hierarchy
5133 * but the memcg is pinned through dependency. The memcg should stop
5134 * applying policies and should revert to the vanilla state as it may be
5135 * made visible again.
5137 * The current implementation only resets the essential configurations.
5138 * This needs to be expanded to cover all the visible parts.
5140 static void mem_cgroup_css_reset(struct cgroup_subsys_state
*css
)
5142 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
5144 mem_cgroup_resize_limit(memcg
, PAGE_COUNTER_MAX
);
5145 mem_cgroup_resize_memsw_limit(memcg
, PAGE_COUNTER_MAX
);
5146 memcg_update_kmem_limit(memcg
, PAGE_COUNTER_MAX
);
5147 memcg
->soft_limit
= 0;
5151 /* Handlers for move charge at task migration. */
5152 static int mem_cgroup_do_precharge(unsigned long count
)
5156 /* Try a single bulk charge without reclaim first */
5157 ret
= try_charge(mc
.to
, GFP_KERNEL
& ~__GFP_WAIT
, count
);
5159 mc
.precharge
+= count
;
5162 if (ret
== -EINTR
) {
5163 cancel_charge(root_mem_cgroup
, count
);
5167 /* Try charges one by one with reclaim */
5169 ret
= try_charge(mc
.to
, GFP_KERNEL
& ~__GFP_NORETRY
, 1);
5171 * In case of failure, any residual charges against
5172 * mc.to will be dropped by mem_cgroup_clear_mc()
5173 * later on. However, cancel any charges that are
5174 * bypassed to root right away or they'll be lost.
5177 cancel_charge(root_mem_cgroup
, 1);
5187 * get_mctgt_type - get target type of moving charge
5188 * @vma: the vma the pte to be checked belongs
5189 * @addr: the address corresponding to the pte to be checked
5190 * @ptent: the pte to be checked
5191 * @target: the pointer the target page or swap ent will be stored(can be NULL)
5194 * 0(MC_TARGET_NONE): if the pte is not a target for move charge.
5195 * 1(MC_TARGET_PAGE): if the page corresponding to this pte is a target for
5196 * move charge. if @target is not NULL, the page is stored in target->page
5197 * with extra refcnt got(Callers should handle it).
5198 * 2(MC_TARGET_SWAP): if the swap entry corresponding to this pte is a
5199 * target for charge migration. if @target is not NULL, the entry is stored
5202 * Called with pte lock held.
5209 enum mc_target_type
{
5215 static struct page
*mc_handle_present_pte(struct vm_area_struct
*vma
,
5216 unsigned long addr
, pte_t ptent
)
5218 struct page
*page
= vm_normal_page(vma
, addr
, ptent
);
5220 if (!page
|| !page_mapped(page
))
5222 if (PageAnon(page
)) {
5223 /* we don't move shared anon */
5226 } else if (!move_file())
5227 /* we ignore mapcount for file pages */
5229 if (!get_page_unless_zero(page
))
5236 static struct page
*mc_handle_swap_pte(struct vm_area_struct
*vma
,
5237 unsigned long addr
, pte_t ptent
, swp_entry_t
*entry
)
5239 struct page
*page
= NULL
;
5240 swp_entry_t ent
= pte_to_swp_entry(ptent
);
5242 if (!move_anon() || non_swap_entry(ent
))
5245 * Because lookup_swap_cache() updates some statistics counter,
5246 * we call find_get_page() with swapper_space directly.
5248 page
= find_get_page(swap_address_space(ent
), ent
.val
);
5249 if (do_swap_account
)
5250 entry
->val
= ent
.val
;
5255 static struct page
*mc_handle_swap_pte(struct vm_area_struct
*vma
,
5256 unsigned long addr
, pte_t ptent
, swp_entry_t
*entry
)
5262 static struct page
*mc_handle_file_pte(struct vm_area_struct
*vma
,
5263 unsigned long addr
, pte_t ptent
, swp_entry_t
*entry
)
5265 struct page
*page
= NULL
;
5266 struct address_space
*mapping
;
5269 if (!vma
->vm_file
) /* anonymous vma */
5274 mapping
= vma
->vm_file
->f_mapping
;
5275 if (pte_none(ptent
))
5276 pgoff
= linear_page_index(vma
, addr
);
5277 else /* pte_file(ptent) is true */
5278 pgoff
= pte_to_pgoff(ptent
);
5280 /* page is moved even if it's not RSS of this task(page-faulted). */
5282 /* shmem/tmpfs may report page out on swap: account for that too. */
5283 if (shmem_mapping(mapping
)) {
5284 page
= find_get_entry(mapping
, pgoff
);
5285 if (radix_tree_exceptional_entry(page
)) {
5286 swp_entry_t swp
= radix_to_swp_entry(page
);
5287 if (do_swap_account
)
5289 page
= find_get_page(swap_address_space(swp
), swp
.val
);
5292 page
= find_get_page(mapping
, pgoff
);
5294 page
= find_get_page(mapping
, pgoff
);
5299 static enum mc_target_type
get_mctgt_type(struct vm_area_struct
*vma
,
5300 unsigned long addr
, pte_t ptent
, union mc_target
*target
)
5302 struct page
*page
= NULL
;
5303 struct page_cgroup
*pc
;
5304 enum mc_target_type ret
= MC_TARGET_NONE
;
5305 swp_entry_t ent
= { .val
= 0 };
5307 if (pte_present(ptent
))
5308 page
= mc_handle_present_pte(vma
, addr
, ptent
);
5309 else if (is_swap_pte(ptent
))
5310 page
= mc_handle_swap_pte(vma
, addr
, ptent
, &ent
);
5311 else if (pte_none(ptent
) || pte_file(ptent
))
5312 page
= mc_handle_file_pte(vma
, addr
, ptent
, &ent
);
5314 if (!page
&& !ent
.val
)
5317 pc
= lookup_page_cgroup(page
);
5319 * Do only loose check w/o serialization.
5320 * mem_cgroup_move_account() checks the pc is valid or
5321 * not under LRU exclusion.
5323 if (PageCgroupUsed(pc
) && pc
->mem_cgroup
== mc
.from
) {
5324 ret
= MC_TARGET_PAGE
;
5326 target
->page
= page
;
5328 if (!ret
|| !target
)
5331 /* There is a swap entry and a page doesn't exist or isn't charged */
5332 if (ent
.val
&& !ret
&&
5333 mem_cgroup_id(mc
.from
) == lookup_swap_cgroup_id(ent
)) {
5334 ret
= MC_TARGET_SWAP
;
5341 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
5343 * We don't consider swapping or file mapped pages because THP does not
5344 * support them for now.
5345 * Caller should make sure that pmd_trans_huge(pmd) is true.
5347 static enum mc_target_type
get_mctgt_type_thp(struct vm_area_struct
*vma
,
5348 unsigned long addr
, pmd_t pmd
, union mc_target
*target
)
5350 struct page
*page
= NULL
;
5351 struct page_cgroup
*pc
;
5352 enum mc_target_type ret
= MC_TARGET_NONE
;
5354 page
= pmd_page(pmd
);
5355 VM_BUG_ON_PAGE(!page
|| !PageHead(page
), page
);
5358 pc
= lookup_page_cgroup(page
);
5359 if (PageCgroupUsed(pc
) && pc
->mem_cgroup
== mc
.from
) {
5360 ret
= MC_TARGET_PAGE
;
5363 target
->page
= page
;
5369 static inline enum mc_target_type
get_mctgt_type_thp(struct vm_area_struct
*vma
,
5370 unsigned long addr
, pmd_t pmd
, union mc_target
*target
)
5372 return MC_TARGET_NONE
;
5376 static int mem_cgroup_count_precharge_pte_range(pmd_t
*pmd
,
5377 unsigned long addr
, unsigned long end
,
5378 struct mm_walk
*walk
)
5380 struct vm_area_struct
*vma
= walk
->private;
5384 if (pmd_trans_huge_lock(pmd
, vma
, &ptl
) == 1) {
5385 if (get_mctgt_type_thp(vma
, addr
, *pmd
, NULL
) == MC_TARGET_PAGE
)
5386 mc
.precharge
+= HPAGE_PMD_NR
;
5391 if (pmd_trans_unstable(pmd
))
5393 pte
= pte_offset_map_lock(vma
->vm_mm
, pmd
, addr
, &ptl
);
5394 for (; addr
!= end
; pte
++, addr
+= PAGE_SIZE
)
5395 if (get_mctgt_type(vma
, addr
, *pte
, NULL
))
5396 mc
.precharge
++; /* increment precharge temporarily */
5397 pte_unmap_unlock(pte
- 1, ptl
);
5403 static unsigned long mem_cgroup_count_precharge(struct mm_struct
*mm
)
5405 unsigned long precharge
;
5406 struct vm_area_struct
*vma
;
5408 down_read(&mm
->mmap_sem
);
5409 for (vma
= mm
->mmap
; vma
; vma
= vma
->vm_next
) {
5410 struct mm_walk mem_cgroup_count_precharge_walk
= {
5411 .pmd_entry
= mem_cgroup_count_precharge_pte_range
,
5415 if (is_vm_hugetlb_page(vma
))
5417 walk_page_range(vma
->vm_start
, vma
->vm_end
,
5418 &mem_cgroup_count_precharge_walk
);
5420 up_read(&mm
->mmap_sem
);
5422 precharge
= mc
.precharge
;
5428 static int mem_cgroup_precharge_mc(struct mm_struct
*mm
)
5430 unsigned long precharge
= mem_cgroup_count_precharge(mm
);
5432 VM_BUG_ON(mc
.moving_task
);
5433 mc
.moving_task
= current
;
5434 return mem_cgroup_do_precharge(precharge
);
5437 /* cancels all extra charges on mc.from and mc.to, and wakes up all waiters. */
5438 static void __mem_cgroup_clear_mc(void)
5440 struct mem_cgroup
*from
= mc
.from
;
5441 struct mem_cgroup
*to
= mc
.to
;
5443 /* we must uncharge all the leftover precharges from mc.to */
5445 cancel_charge(mc
.to
, mc
.precharge
);
5449 * we didn't uncharge from mc.from at mem_cgroup_move_account(), so
5450 * we must uncharge here.
5452 if (mc
.moved_charge
) {
5453 cancel_charge(mc
.from
, mc
.moved_charge
);
5454 mc
.moved_charge
= 0;
5456 /* we must fixup refcnts and charges */
5457 if (mc
.moved_swap
) {
5458 /* uncharge swap account from the old cgroup */
5459 if (!mem_cgroup_is_root(mc
.from
))
5460 page_counter_uncharge(&mc
.from
->memsw
, mc
.moved_swap
);
5463 * we charged both to->memory and to->memsw, so we
5464 * should uncharge to->memory.
5466 if (!mem_cgroup_is_root(mc
.to
))
5467 page_counter_uncharge(&mc
.to
->memory
, mc
.moved_swap
);
5469 css_put_many(&mc
.from
->css
, mc
.moved_swap
);
5471 /* we've already done css_get(mc.to) */
5474 memcg_oom_recover(from
);
5475 memcg_oom_recover(to
);
5476 wake_up_all(&mc
.waitq
);
5479 static void mem_cgroup_clear_mc(void)
5481 struct mem_cgroup
*from
= mc
.from
;
5484 * we must clear moving_task before waking up waiters at the end of
5487 mc
.moving_task
= NULL
;
5488 __mem_cgroup_clear_mc();
5489 spin_lock(&mc
.lock
);
5492 spin_unlock(&mc
.lock
);
5493 mem_cgroup_end_move(from
);
5496 static int mem_cgroup_can_attach(struct cgroup_subsys_state
*css
,
5497 struct cgroup_taskset
*tset
)
5499 struct task_struct
*p
= cgroup_taskset_first(tset
);
5501 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
5502 unsigned long move_charge_at_immigrate
;
5505 * We are now commited to this value whatever it is. Changes in this
5506 * tunable will only affect upcoming migrations, not the current one.
5507 * So we need to save it, and keep it going.
5509 move_charge_at_immigrate
= memcg
->move_charge_at_immigrate
;
5510 if (move_charge_at_immigrate
) {
5511 struct mm_struct
*mm
;
5512 struct mem_cgroup
*from
= mem_cgroup_from_task(p
);
5514 VM_BUG_ON(from
== memcg
);
5516 mm
= get_task_mm(p
);
5519 /* We move charges only when we move a owner of the mm */
5520 if (mm
->owner
== p
) {
5523 VM_BUG_ON(mc
.precharge
);
5524 VM_BUG_ON(mc
.moved_charge
);
5525 VM_BUG_ON(mc
.moved_swap
);
5526 mem_cgroup_start_move(from
);
5527 spin_lock(&mc
.lock
);
5530 mc
.immigrate_flags
= move_charge_at_immigrate
;
5531 spin_unlock(&mc
.lock
);
5532 /* We set mc.moving_task later */
5534 ret
= mem_cgroup_precharge_mc(mm
);
5536 mem_cgroup_clear_mc();
5543 static void mem_cgroup_cancel_attach(struct cgroup_subsys_state
*css
,
5544 struct cgroup_taskset
*tset
)
5546 mem_cgroup_clear_mc();
5549 static int mem_cgroup_move_charge_pte_range(pmd_t
*pmd
,
5550 unsigned long addr
, unsigned long end
,
5551 struct mm_walk
*walk
)
5554 struct vm_area_struct
*vma
= walk
->private;
5557 enum mc_target_type target_type
;
5558 union mc_target target
;
5560 struct page_cgroup
*pc
;
5563 * We don't take compound_lock() here but no race with splitting thp
5565 * - if pmd_trans_huge_lock() returns 1, the relevant thp is not
5566 * under splitting, which means there's no concurrent thp split,
5567 * - if another thread runs into split_huge_page() just after we
5568 * entered this if-block, the thread must wait for page table lock
5569 * to be unlocked in __split_huge_page_splitting(), where the main
5570 * part of thp split is not executed yet.
5572 if (pmd_trans_huge_lock(pmd
, vma
, &ptl
) == 1) {
5573 if (mc
.precharge
< HPAGE_PMD_NR
) {
5577 target_type
= get_mctgt_type_thp(vma
, addr
, *pmd
, &target
);
5578 if (target_type
== MC_TARGET_PAGE
) {
5580 if (!isolate_lru_page(page
)) {
5581 pc
= lookup_page_cgroup(page
);
5582 if (!mem_cgroup_move_account(page
, HPAGE_PMD_NR
,
5583 pc
, mc
.from
, mc
.to
)) {
5584 mc
.precharge
-= HPAGE_PMD_NR
;
5585 mc
.moved_charge
+= HPAGE_PMD_NR
;
5587 putback_lru_page(page
);
5595 if (pmd_trans_unstable(pmd
))
5598 pte
= pte_offset_map_lock(vma
->vm_mm
, pmd
, addr
, &ptl
);
5599 for (; addr
!= end
; addr
+= PAGE_SIZE
) {
5600 pte_t ptent
= *(pte
++);
5606 switch (get_mctgt_type(vma
, addr
, ptent
, &target
)) {
5607 case MC_TARGET_PAGE
:
5609 if (isolate_lru_page(page
))
5611 pc
= lookup_page_cgroup(page
);
5612 if (!mem_cgroup_move_account(page
, 1, pc
,
5615 /* we uncharge from mc.from later. */
5618 putback_lru_page(page
);
5619 put
: /* get_mctgt_type() gets the page */
5622 case MC_TARGET_SWAP
:
5624 if (!mem_cgroup_move_swap_account(ent
, mc
.from
, mc
.to
)) {
5626 /* we fixup refcnts and charges later. */
5634 pte_unmap_unlock(pte
- 1, ptl
);
5639 * We have consumed all precharges we got in can_attach().
5640 * We try charge one by one, but don't do any additional
5641 * charges to mc.to if we have failed in charge once in attach()
5644 ret
= mem_cgroup_do_precharge(1);
5652 static void mem_cgroup_move_charge(struct mm_struct
*mm
)
5654 struct vm_area_struct
*vma
;
5656 lru_add_drain_all();
5658 if (unlikely(!down_read_trylock(&mm
->mmap_sem
))) {
5660 * Someone who are holding the mmap_sem might be waiting in
5661 * waitq. So we cancel all extra charges, wake up all waiters,
5662 * and retry. Because we cancel precharges, we might not be able
5663 * to move enough charges, but moving charge is a best-effort
5664 * feature anyway, so it wouldn't be a big problem.
5666 __mem_cgroup_clear_mc();
5670 for (vma
= mm
->mmap
; vma
; vma
= vma
->vm_next
) {
5672 struct mm_walk mem_cgroup_move_charge_walk
= {
5673 .pmd_entry
= mem_cgroup_move_charge_pte_range
,
5677 if (is_vm_hugetlb_page(vma
))
5679 ret
= walk_page_range(vma
->vm_start
, vma
->vm_end
,
5680 &mem_cgroup_move_charge_walk
);
5683 * means we have consumed all precharges and failed in
5684 * doing additional charge. Just abandon here.
5688 up_read(&mm
->mmap_sem
);
5691 static void mem_cgroup_move_task(struct cgroup_subsys_state
*css
,
5692 struct cgroup_taskset
*tset
)
5694 struct task_struct
*p
= cgroup_taskset_first(tset
);
5695 struct mm_struct
*mm
= get_task_mm(p
);
5699 mem_cgroup_move_charge(mm
);
5703 mem_cgroup_clear_mc();
5705 #else /* !CONFIG_MMU */
5706 static int mem_cgroup_can_attach(struct cgroup_subsys_state
*css
,
5707 struct cgroup_taskset
*tset
)
5711 static void mem_cgroup_cancel_attach(struct cgroup_subsys_state
*css
,
5712 struct cgroup_taskset
*tset
)
5715 static void mem_cgroup_move_task(struct cgroup_subsys_state
*css
,
5716 struct cgroup_taskset
*tset
)
5722 * Cgroup retains root cgroups across [un]mount cycles making it necessary
5723 * to verify whether we're attached to the default hierarchy on each mount
5726 static void mem_cgroup_bind(struct cgroup_subsys_state
*root_css
)
5729 * use_hierarchy is forced on the default hierarchy. cgroup core
5730 * guarantees that @root doesn't have any children, so turning it
5731 * on for the root memcg is enough.
5733 if (cgroup_on_dfl(root_css
->cgroup
))
5734 mem_cgroup_from_css(root_css
)->use_hierarchy
= true;
5737 struct cgroup_subsys memory_cgrp_subsys
= {
5738 .css_alloc
= mem_cgroup_css_alloc
,
5739 .css_online
= mem_cgroup_css_online
,
5740 .css_offline
= mem_cgroup_css_offline
,
5741 .css_free
= mem_cgroup_css_free
,
5742 .css_reset
= mem_cgroup_css_reset
,
5743 .can_attach
= mem_cgroup_can_attach
,
5744 .cancel_attach
= mem_cgroup_cancel_attach
,
5745 .attach
= mem_cgroup_move_task
,
5746 .bind
= mem_cgroup_bind
,
5747 .legacy_cftypes
= mem_cgroup_files
,
5751 #ifdef CONFIG_MEMCG_SWAP
5752 static int __init
enable_swap_account(char *s
)
5754 if (!strcmp(s
, "1"))
5755 really_do_swap_account
= 1;
5756 else if (!strcmp(s
, "0"))
5757 really_do_swap_account
= 0;
5760 __setup("swapaccount=", enable_swap_account
);
5762 static void __init
memsw_file_init(void)
5764 WARN_ON(cgroup_add_legacy_cftypes(&memory_cgrp_subsys
,
5765 memsw_cgroup_files
));
5768 static void __init
enable_swap_cgroup(void)
5770 if (!mem_cgroup_disabled() && really_do_swap_account
) {
5771 do_swap_account
= 1;
5777 static void __init
enable_swap_cgroup(void)
5782 #ifdef CONFIG_MEMCG_SWAP
5784 * mem_cgroup_swapout - transfer a memsw charge to swap
5785 * @page: page whose memsw charge to transfer
5786 * @entry: swap entry to move the charge to
5788 * Transfer the memsw charge of @page to @entry.
5790 void mem_cgroup_swapout(struct page
*page
, swp_entry_t entry
)
5792 struct page_cgroup
*pc
;
5793 unsigned short oldid
;
5795 VM_BUG_ON_PAGE(PageLRU(page
), page
);
5796 VM_BUG_ON_PAGE(page_count(page
), page
);
5798 if (!do_swap_account
)
5801 pc
= lookup_page_cgroup(page
);
5803 /* Readahead page, never charged */
5804 if (!PageCgroupUsed(pc
))
5807 VM_BUG_ON_PAGE(!(pc
->flags
& PCG_MEMSW
), page
);
5809 oldid
= swap_cgroup_record(entry
, mem_cgroup_id(pc
->mem_cgroup
));
5810 VM_BUG_ON_PAGE(oldid
, page
);
5812 pc
->flags
&= ~PCG_MEMSW
;
5813 css_get(&pc
->mem_cgroup
->css
);
5814 mem_cgroup_swap_statistics(pc
->mem_cgroup
, true);
5818 * mem_cgroup_uncharge_swap - uncharge a swap entry
5819 * @entry: swap entry to uncharge
5821 * Drop the memsw charge associated with @entry.
5823 void mem_cgroup_uncharge_swap(swp_entry_t entry
)
5825 struct mem_cgroup
*memcg
;
5828 if (!do_swap_account
)
5831 id
= swap_cgroup_record(entry
, 0);
5833 memcg
= mem_cgroup_lookup(id
);
5835 if (!mem_cgroup_is_root(memcg
))
5836 page_counter_uncharge(&memcg
->memsw
, 1);
5837 mem_cgroup_swap_statistics(memcg
, false);
5838 css_put(&memcg
->css
);
5845 * mem_cgroup_try_charge - try charging a page
5846 * @page: page to charge
5847 * @mm: mm context of the victim
5848 * @gfp_mask: reclaim mode
5849 * @memcgp: charged memcg return
5851 * Try to charge @page to the memcg that @mm belongs to, reclaiming
5852 * pages according to @gfp_mask if necessary.
5854 * Returns 0 on success, with *@memcgp pointing to the charged memcg.
5855 * Otherwise, an error code is returned.
5857 * After page->mapping has been set up, the caller must finalize the
5858 * charge with mem_cgroup_commit_charge(). Or abort the transaction
5859 * with mem_cgroup_cancel_charge() in case page instantiation fails.
5861 int mem_cgroup_try_charge(struct page
*page
, struct mm_struct
*mm
,
5862 gfp_t gfp_mask
, struct mem_cgroup
**memcgp
)
5864 struct mem_cgroup
*memcg
= NULL
;
5865 unsigned int nr_pages
= 1;
5868 if (mem_cgroup_disabled())
5871 if (PageSwapCache(page
)) {
5872 struct page_cgroup
*pc
= lookup_page_cgroup(page
);
5874 * Every swap fault against a single page tries to charge the
5875 * page, bail as early as possible. shmem_unuse() encounters
5876 * already charged pages, too. The USED bit is protected by
5877 * the page lock, which serializes swap cache removal, which
5878 * in turn serializes uncharging.
5880 if (PageCgroupUsed(pc
))
5884 if (PageTransHuge(page
)) {
5885 nr_pages
<<= compound_order(page
);
5886 VM_BUG_ON_PAGE(!PageTransHuge(page
), page
);
5889 if (do_swap_account
&& PageSwapCache(page
))
5890 memcg
= try_get_mem_cgroup_from_page(page
);
5892 memcg
= get_mem_cgroup_from_mm(mm
);
5894 ret
= try_charge(memcg
, gfp_mask
, nr_pages
);
5896 css_put(&memcg
->css
);
5898 if (ret
== -EINTR
) {
5899 memcg
= root_mem_cgroup
;
5908 * mem_cgroup_commit_charge - commit a page charge
5909 * @page: page to charge
5910 * @memcg: memcg to charge the page to
5911 * @lrucare: page might be on LRU already
5913 * Finalize a charge transaction started by mem_cgroup_try_charge(),
5914 * after page->mapping has been set up. This must happen atomically
5915 * as part of the page instantiation, i.e. under the page table lock
5916 * for anonymous pages, under the page lock for page and swap cache.
5918 * In addition, the page must not be on the LRU during the commit, to
5919 * prevent racing with task migration. If it might be, use @lrucare.
5921 * Use mem_cgroup_cancel_charge() to cancel the transaction instead.
5923 void mem_cgroup_commit_charge(struct page
*page
, struct mem_cgroup
*memcg
,
5926 unsigned int nr_pages
= 1;
5928 VM_BUG_ON_PAGE(!page
->mapping
, page
);
5929 VM_BUG_ON_PAGE(PageLRU(page
) && !lrucare
, page
);
5931 if (mem_cgroup_disabled())
5934 * Swap faults will attempt to charge the same page multiple
5935 * times. But reuse_swap_page() might have removed the page
5936 * from swapcache already, so we can't check PageSwapCache().
5941 commit_charge(page
, memcg
, lrucare
);
5943 if (PageTransHuge(page
)) {
5944 nr_pages
<<= compound_order(page
);
5945 VM_BUG_ON_PAGE(!PageTransHuge(page
), page
);
5948 local_irq_disable();
5949 mem_cgroup_charge_statistics(memcg
, page
, nr_pages
);
5950 memcg_check_events(memcg
, page
);
5953 if (do_swap_account
&& PageSwapCache(page
)) {
5954 swp_entry_t entry
= { .val
= page_private(page
) };
5956 * The swap entry might not get freed for a long time,
5957 * let's not wait for it. The page already received a
5958 * memory+swap charge, drop the swap entry duplicate.
5960 mem_cgroup_uncharge_swap(entry
);
5965 * mem_cgroup_cancel_charge - cancel a page charge
5966 * @page: page to charge
5967 * @memcg: memcg to charge the page to
5969 * Cancel a charge transaction started by mem_cgroup_try_charge().
5971 void mem_cgroup_cancel_charge(struct page
*page
, struct mem_cgroup
*memcg
)
5973 unsigned int nr_pages
= 1;
5975 if (mem_cgroup_disabled())
5978 * Swap faults will attempt to charge the same page multiple
5979 * times. But reuse_swap_page() might have removed the page
5980 * from swapcache already, so we can't check PageSwapCache().
5985 if (PageTransHuge(page
)) {
5986 nr_pages
<<= compound_order(page
);
5987 VM_BUG_ON_PAGE(!PageTransHuge(page
), page
);
5990 cancel_charge(memcg
, nr_pages
);
5993 static void uncharge_batch(struct mem_cgroup
*memcg
, unsigned long pgpgout
,
5994 unsigned long nr_mem
, unsigned long nr_memsw
,
5995 unsigned long nr_anon
, unsigned long nr_file
,
5996 unsigned long nr_huge
, struct page
*dummy_page
)
5998 unsigned long flags
;
6000 if (!mem_cgroup_is_root(memcg
)) {
6002 page_counter_uncharge(&memcg
->memory
, nr_mem
);
6004 page_counter_uncharge(&memcg
->memsw
, nr_memsw
);
6005 memcg_oom_recover(memcg
);
6008 local_irq_save(flags
);
6009 __this_cpu_sub(memcg
->stat
->count
[MEM_CGROUP_STAT_RSS
], nr_anon
);
6010 __this_cpu_sub(memcg
->stat
->count
[MEM_CGROUP_STAT_CACHE
], nr_file
);
6011 __this_cpu_sub(memcg
->stat
->count
[MEM_CGROUP_STAT_RSS_HUGE
], nr_huge
);
6012 __this_cpu_add(memcg
->stat
->events
[MEM_CGROUP_EVENTS_PGPGOUT
], pgpgout
);
6013 __this_cpu_add(memcg
->stat
->nr_page_events
, nr_anon
+ nr_file
);
6014 memcg_check_events(memcg
, dummy_page
);
6015 local_irq_restore(flags
);
6017 if (!mem_cgroup_is_root(memcg
))
6018 css_put_many(&memcg
->css
, max(nr_mem
, nr_memsw
));
6021 static void uncharge_list(struct list_head
*page_list
)
6023 struct mem_cgroup
*memcg
= NULL
;
6024 unsigned long nr_memsw
= 0;
6025 unsigned long nr_anon
= 0;
6026 unsigned long nr_file
= 0;
6027 unsigned long nr_huge
= 0;
6028 unsigned long pgpgout
= 0;
6029 unsigned long nr_mem
= 0;
6030 struct list_head
*next
;
6033 next
= page_list
->next
;
6035 unsigned int nr_pages
= 1;
6036 struct page_cgroup
*pc
;
6038 page
= list_entry(next
, struct page
, lru
);
6039 next
= page
->lru
.next
;
6041 VM_BUG_ON_PAGE(PageLRU(page
), page
);
6042 VM_BUG_ON_PAGE(page_count(page
), page
);
6044 pc
= lookup_page_cgroup(page
);
6045 if (!PageCgroupUsed(pc
))
6049 * Nobody should be changing or seriously looking at
6050 * pc->mem_cgroup and pc->flags at this point, we have
6051 * fully exclusive access to the page.
6054 if (memcg
!= pc
->mem_cgroup
) {
6056 uncharge_batch(memcg
, pgpgout
, nr_mem
, nr_memsw
,
6057 nr_anon
, nr_file
, nr_huge
, page
);
6058 pgpgout
= nr_mem
= nr_memsw
= 0;
6059 nr_anon
= nr_file
= nr_huge
= 0;
6061 memcg
= pc
->mem_cgroup
;
6064 if (PageTransHuge(page
)) {
6065 nr_pages
<<= compound_order(page
);
6066 VM_BUG_ON_PAGE(!PageTransHuge(page
), page
);
6067 nr_huge
+= nr_pages
;
6071 nr_anon
+= nr_pages
;
6073 nr_file
+= nr_pages
;
6075 if (pc
->flags
& PCG_MEM
)
6077 if (pc
->flags
& PCG_MEMSW
)
6078 nr_memsw
+= nr_pages
;
6082 } while (next
!= page_list
);
6085 uncharge_batch(memcg
, pgpgout
, nr_mem
, nr_memsw
,
6086 nr_anon
, nr_file
, nr_huge
, page
);
6090 * mem_cgroup_uncharge - uncharge a page
6091 * @page: page to uncharge
6093 * Uncharge a page previously charged with mem_cgroup_try_charge() and
6094 * mem_cgroup_commit_charge().
6096 void mem_cgroup_uncharge(struct page
*page
)
6098 struct page_cgroup
*pc
;
6100 if (mem_cgroup_disabled())
6103 /* Don't touch page->lru of any random page, pre-check: */
6104 pc
= lookup_page_cgroup(page
);
6105 if (!PageCgroupUsed(pc
))
6108 INIT_LIST_HEAD(&page
->lru
);
6109 uncharge_list(&page
->lru
);
6113 * mem_cgroup_uncharge_list - uncharge a list of page
6114 * @page_list: list of pages to uncharge
6116 * Uncharge a list of pages previously charged with
6117 * mem_cgroup_try_charge() and mem_cgroup_commit_charge().
6119 void mem_cgroup_uncharge_list(struct list_head
*page_list
)
6121 if (mem_cgroup_disabled())
6124 if (!list_empty(page_list
))
6125 uncharge_list(page_list
);
6129 * mem_cgroup_migrate - migrate a charge to another page
6130 * @oldpage: currently charged page
6131 * @newpage: page to transfer the charge to
6132 * @lrucare: both pages might be on the LRU already
6134 * Migrate the charge from @oldpage to @newpage.
6136 * Both pages must be locked, @newpage->mapping must be set up.
6138 void mem_cgroup_migrate(struct page
*oldpage
, struct page
*newpage
,
6141 struct page_cgroup
*pc
;
6144 VM_BUG_ON_PAGE(!PageLocked(oldpage
), oldpage
);
6145 VM_BUG_ON_PAGE(!PageLocked(newpage
), newpage
);
6146 VM_BUG_ON_PAGE(!lrucare
&& PageLRU(oldpage
), oldpage
);
6147 VM_BUG_ON_PAGE(!lrucare
&& PageLRU(newpage
), newpage
);
6148 VM_BUG_ON_PAGE(PageAnon(oldpage
) != PageAnon(newpage
), newpage
);
6149 VM_BUG_ON_PAGE(PageTransHuge(oldpage
) != PageTransHuge(newpage
),
6152 if (mem_cgroup_disabled())
6155 /* Page cache replacement: new page already charged? */
6156 pc
= lookup_page_cgroup(newpage
);
6157 if (PageCgroupUsed(pc
))
6161 * Swapcache readahead pages can get migrated before being
6162 * charged, and migration from compaction can happen to an
6163 * uncharged page when the PFN walker finds a page that
6164 * reclaim just put back on the LRU but has not released yet.
6166 pc
= lookup_page_cgroup(oldpage
);
6167 if (!PageCgroupUsed(pc
))
6170 VM_BUG_ON_PAGE(!(pc
->flags
& PCG_MEM
), oldpage
);
6171 VM_BUG_ON_PAGE(do_swap_account
&& !(pc
->flags
& PCG_MEMSW
), oldpage
);
6174 lock_page_lru(oldpage
, &isolated
);
6179 unlock_page_lru(oldpage
, isolated
);
6181 commit_charge(newpage
, pc
->mem_cgroup
, lrucare
);
6185 * subsys_initcall() for memory controller.
6187 * Some parts like hotcpu_notifier() have to be initialized from this context
6188 * because of lock dependencies (cgroup_lock -> cpu hotplug) but basically
6189 * everything that doesn't depend on a specific mem_cgroup structure should
6190 * be initialized from here.
6192 static int __init
mem_cgroup_init(void)
6194 hotcpu_notifier(memcg_cpu_hotplug_callback
, 0);
6195 enable_swap_cgroup();
6196 mem_cgroup_soft_limit_tree_init();
6200 subsys_initcall(mem_cgroup_init
);