1 /* memcontrol.c - Memory Controller
3 * Copyright IBM Corporation, 2007
4 * Author Balbir Singh <balbir@linux.vnet.ibm.com>
6 * Copyright 2007 OpenVZ SWsoft Inc
7 * Author: Pavel Emelianov <xemul@openvz.org>
10 * Copyright (C) 2009 Nokia Corporation
11 * Author: Kirill A. Shutemov
13 * Kernel Memory Controller
14 * Copyright (C) 2012 Parallels Inc. and Google Inc.
15 * Authors: Glauber Costa and Suleiman Souhlal
17 * This program is free software; you can redistribute it and/or modify
18 * it under the terms of the GNU General Public License as published by
19 * the Free Software Foundation; either version 2 of the License, or
20 * (at your option) any later version.
22 * This program is distributed in the hope that it will be useful,
23 * but WITHOUT ANY WARRANTY; without even the implied warranty of
24 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
25 * GNU General Public License for more details.
28 #include <linux/res_counter.h>
29 #include <linux/memcontrol.h>
30 #include <linux/cgroup.h>
32 #include <linux/hugetlb.h>
33 #include <linux/pagemap.h>
34 #include <linux/smp.h>
35 #include <linux/page-flags.h>
36 #include <linux/backing-dev.h>
37 #include <linux/bit_spinlock.h>
38 #include <linux/rcupdate.h>
39 #include <linux/limits.h>
40 #include <linux/export.h>
41 #include <linux/mutex.h>
42 #include <linux/rbtree.h>
43 #include <linux/slab.h>
44 #include <linux/swap.h>
45 #include <linux/swapops.h>
46 #include <linux/spinlock.h>
47 #include <linux/eventfd.h>
48 #include <linux/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 mem_cgroup_reclaim_iter
{
148 * last scanned hierarchy member. Valid only if last_dead_count
149 * matches memcg->dead_count of the hierarchy root group.
151 struct mem_cgroup
*last_visited
;
154 /* scan generation, increased every round-trip */
155 unsigned int generation
;
159 * per-zone information in memory controller.
161 struct mem_cgroup_per_zone
{
162 struct lruvec lruvec
;
163 unsigned long lru_size
[NR_LRU_LISTS
];
165 struct mem_cgroup_reclaim_iter reclaim_iter
[DEF_PRIORITY
+ 1];
167 struct rb_node tree_node
; /* RB tree node */
168 unsigned long long usage_in_excess
;/* Set to the value by which */
169 /* the soft limit is exceeded*/
171 struct mem_cgroup
*memcg
; /* Back pointer, we cannot */
172 /* use container_of */
175 struct mem_cgroup_per_node
{
176 struct mem_cgroup_per_zone zoneinfo
[MAX_NR_ZONES
];
180 * Cgroups above their limits are maintained in a RB-Tree, independent of
181 * their hierarchy representation
184 struct mem_cgroup_tree_per_zone
{
185 struct rb_root rb_root
;
189 struct mem_cgroup_tree_per_node
{
190 struct mem_cgroup_tree_per_zone rb_tree_per_zone
[MAX_NR_ZONES
];
193 struct mem_cgroup_tree
{
194 struct mem_cgroup_tree_per_node
*rb_tree_per_node
[MAX_NUMNODES
];
197 static struct mem_cgroup_tree soft_limit_tree __read_mostly
;
199 struct mem_cgroup_threshold
{
200 struct eventfd_ctx
*eventfd
;
205 struct mem_cgroup_threshold_ary
{
206 /* An array index points to threshold just below or equal to usage. */
207 int current_threshold
;
208 /* Size of entries[] */
210 /* Array of thresholds */
211 struct mem_cgroup_threshold entries
[0];
214 struct mem_cgroup_thresholds
{
215 /* Primary thresholds array */
216 struct mem_cgroup_threshold_ary
*primary
;
218 * Spare threshold array.
219 * This is needed to make mem_cgroup_unregister_event() "never fail".
220 * It must be able to store at least primary->size - 1 entries.
222 struct mem_cgroup_threshold_ary
*spare
;
226 struct mem_cgroup_eventfd_list
{
227 struct list_head list
;
228 struct eventfd_ctx
*eventfd
;
232 * cgroup_event represents events which userspace want to receive.
234 struct mem_cgroup_event
{
236 * memcg which the event belongs to.
238 struct mem_cgroup
*memcg
;
240 * eventfd to signal userspace about the event.
242 struct eventfd_ctx
*eventfd
;
244 * Each of these stored in a list by the cgroup.
246 struct list_head list
;
248 * register_event() callback will be used to add new userspace
249 * waiter for changes related to this event. Use eventfd_signal()
250 * on eventfd to send notification to userspace.
252 int (*register_event
)(struct mem_cgroup
*memcg
,
253 struct eventfd_ctx
*eventfd
, const char *args
);
255 * unregister_event() callback will be called when userspace closes
256 * the eventfd or on cgroup removing. This callback must be set,
257 * if you want provide notification functionality.
259 void (*unregister_event
)(struct mem_cgroup
*memcg
,
260 struct eventfd_ctx
*eventfd
);
262 * All fields below needed to unregister event when
263 * userspace closes eventfd.
266 wait_queue_head_t
*wqh
;
268 struct work_struct remove
;
271 static void mem_cgroup_threshold(struct mem_cgroup
*memcg
);
272 static void mem_cgroup_oom_notify(struct mem_cgroup
*memcg
);
275 * The memory controller data structure. The memory controller controls both
276 * page cache and RSS per cgroup. We would eventually like to provide
277 * statistics based on the statistics developed by Rik Van Riel for clock-pro,
278 * to help the administrator determine what knobs to tune.
280 * TODO: Add a water mark for the memory controller. Reclaim will begin when
281 * we hit the water mark. May be even add a low water mark, such that
282 * no reclaim occurs from a cgroup at it's low water mark, this is
283 * a feature that will be implemented much later in the future.
286 struct cgroup_subsys_state css
;
288 * the counter to account for memory usage
290 struct res_counter res
;
292 /* vmpressure notifications */
293 struct vmpressure vmpressure
;
296 * the counter to account for mem+swap usage.
298 struct res_counter memsw
;
301 * the counter to account for kernel memory usage.
303 struct res_counter kmem
;
305 * Should the accounting and control be hierarchical, per subtree?
308 unsigned long kmem_account_flags
; /* See KMEM_ACCOUNTED_*, below */
312 atomic_t oom_wakeups
;
315 /* OOM-Killer disable */
316 int oom_kill_disable
;
318 /* set when res.limit == memsw.limit */
319 bool memsw_is_minimum
;
321 /* protect arrays of thresholds */
322 struct mutex thresholds_lock
;
324 /* thresholds for memory usage. RCU-protected */
325 struct mem_cgroup_thresholds thresholds
;
327 /* thresholds for mem+swap usage. RCU-protected */
328 struct mem_cgroup_thresholds memsw_thresholds
;
330 /* For oom notifier event fd */
331 struct list_head oom_notify
;
334 * Should we move charges of a task when a task is moved into this
335 * mem_cgroup ? And what type of charges should we move ?
337 unsigned long move_charge_at_immigrate
;
339 * set > 0 if pages under this cgroup are moving to other cgroup.
341 atomic_t moving_account
;
342 /* taken only while moving_account > 0 */
343 spinlock_t move_lock
;
347 struct mem_cgroup_stat_cpu __percpu
*stat
;
349 * used when a cpu is offlined or other synchronizations
350 * See mem_cgroup_read_stat().
352 struct mem_cgroup_stat_cpu nocpu_base
;
353 spinlock_t pcp_counter_lock
;
356 #if defined(CONFIG_MEMCG_KMEM) && defined(CONFIG_INET)
357 struct cg_proto tcp_mem
;
359 #if defined(CONFIG_MEMCG_KMEM)
360 /* analogous to slab_common's slab_caches list, but per-memcg;
361 * protected by memcg_slab_mutex */
362 struct list_head memcg_slab_caches
;
363 /* Index in the kmem_cache->memcg_params->memcg_caches array */
367 int last_scanned_node
;
369 nodemask_t scan_nodes
;
370 atomic_t numainfo_events
;
371 atomic_t numainfo_updating
;
374 /* List of events which userspace want to receive */
375 struct list_head event_list
;
376 spinlock_t event_list_lock
;
378 struct mem_cgroup_per_node
*nodeinfo
[0];
379 /* WARNING: nodeinfo must be the last member here */
382 /* internal only representation about the status of kmem accounting. */
384 KMEM_ACCOUNTED_ACTIVE
, /* accounted by this cgroup itself */
385 KMEM_ACCOUNTED_DEAD
, /* dead memcg with pending kmem charges */
388 #ifdef CONFIG_MEMCG_KMEM
389 static inline void memcg_kmem_set_active(struct mem_cgroup
*memcg
)
391 set_bit(KMEM_ACCOUNTED_ACTIVE
, &memcg
->kmem_account_flags
);
394 static bool memcg_kmem_is_active(struct mem_cgroup
*memcg
)
396 return test_bit(KMEM_ACCOUNTED_ACTIVE
, &memcg
->kmem_account_flags
);
399 static void memcg_kmem_mark_dead(struct mem_cgroup
*memcg
)
402 * Our caller must use css_get() first, because memcg_uncharge_kmem()
403 * will call css_put() if it sees the memcg is dead.
406 if (test_bit(KMEM_ACCOUNTED_ACTIVE
, &memcg
->kmem_account_flags
))
407 set_bit(KMEM_ACCOUNTED_DEAD
, &memcg
->kmem_account_flags
);
410 static bool memcg_kmem_test_and_clear_dead(struct mem_cgroup
*memcg
)
412 return test_and_clear_bit(KMEM_ACCOUNTED_DEAD
,
413 &memcg
->kmem_account_flags
);
417 /* Stuffs for move charges at task migration. */
419 * Types of charges to be moved. "move_charge_at_immitgrate" and
420 * "immigrate_flags" are treated as a left-shifted bitmap of these types.
423 MOVE_CHARGE_TYPE_ANON
, /* private anonymous page and swap of it */
424 MOVE_CHARGE_TYPE_FILE
, /* file page(including tmpfs) and swap of it */
428 /* "mc" and its members are protected by cgroup_mutex */
429 static struct move_charge_struct
{
430 spinlock_t lock
; /* for from, to */
431 struct mem_cgroup
*from
;
432 struct mem_cgroup
*to
;
433 unsigned long immigrate_flags
;
434 unsigned long precharge
;
435 unsigned long moved_charge
;
436 unsigned long moved_swap
;
437 struct task_struct
*moving_task
; /* a task moving charges */
438 wait_queue_head_t waitq
; /* a waitq for other context */
440 .lock
= __SPIN_LOCK_UNLOCKED(mc
.lock
),
441 .waitq
= __WAIT_QUEUE_HEAD_INITIALIZER(mc
.waitq
),
444 static bool move_anon(void)
446 return test_bit(MOVE_CHARGE_TYPE_ANON
, &mc
.immigrate_flags
);
449 static bool move_file(void)
451 return test_bit(MOVE_CHARGE_TYPE_FILE
, &mc
.immigrate_flags
);
455 * Maximum loops in mem_cgroup_hierarchical_reclaim(), used for soft
456 * limit reclaim to prevent infinite loops, if they ever occur.
458 #define MEM_CGROUP_MAX_RECLAIM_LOOPS 100
459 #define MEM_CGROUP_MAX_SOFT_LIMIT_RECLAIM_LOOPS 2
462 MEM_CGROUP_CHARGE_TYPE_CACHE
= 0,
463 MEM_CGROUP_CHARGE_TYPE_ANON
,
464 MEM_CGROUP_CHARGE_TYPE_SWAPOUT
, /* for accounting swapcache */
465 MEM_CGROUP_CHARGE_TYPE_DROP
, /* a page was unused swap cache */
469 /* for encoding cft->private value on file */
477 #define MEMFILE_PRIVATE(x, val) ((x) << 16 | (val))
478 #define MEMFILE_TYPE(val) ((val) >> 16 & 0xffff)
479 #define MEMFILE_ATTR(val) ((val) & 0xffff)
480 /* Used for OOM nofiier */
481 #define OOM_CONTROL (0)
484 * Reclaim flags for mem_cgroup_hierarchical_reclaim
486 #define MEM_CGROUP_RECLAIM_NOSWAP_BIT 0x0
487 #define MEM_CGROUP_RECLAIM_NOSWAP (1 << MEM_CGROUP_RECLAIM_NOSWAP_BIT)
488 #define MEM_CGROUP_RECLAIM_SHRINK_BIT 0x1
489 #define MEM_CGROUP_RECLAIM_SHRINK (1 << MEM_CGROUP_RECLAIM_SHRINK_BIT)
492 * The memcg_create_mutex will be held whenever a new cgroup is created.
493 * As a consequence, any change that needs to protect against new child cgroups
494 * appearing has to hold it as well.
496 static DEFINE_MUTEX(memcg_create_mutex
);
498 struct mem_cgroup
*mem_cgroup_from_css(struct cgroup_subsys_state
*s
)
500 return s
? container_of(s
, struct mem_cgroup
, css
) : NULL
;
503 /* Some nice accessors for the vmpressure. */
504 struct vmpressure
*memcg_to_vmpressure(struct mem_cgroup
*memcg
)
507 memcg
= root_mem_cgroup
;
508 return &memcg
->vmpressure
;
511 struct cgroup_subsys_state
*vmpressure_to_css(struct vmpressure
*vmpr
)
513 return &container_of(vmpr
, struct mem_cgroup
, vmpressure
)->css
;
516 static inline bool mem_cgroup_is_root(struct mem_cgroup
*memcg
)
518 return (memcg
== root_mem_cgroup
);
522 * We restrict the id in the range of [1, 65535], so it can fit into
525 #define MEM_CGROUP_ID_MAX USHRT_MAX
527 static inline unsigned short mem_cgroup_id(struct mem_cgroup
*memcg
)
530 * The ID of the root cgroup is 0, but memcg treat 0 as an
531 * invalid ID, so we return (cgroup_id + 1).
533 return memcg
->css
.cgroup
->id
+ 1;
536 static inline struct mem_cgroup
*mem_cgroup_from_id(unsigned short id
)
538 struct cgroup_subsys_state
*css
;
540 css
= css_from_id(id
- 1, &memory_cgrp_subsys
);
541 return mem_cgroup_from_css(css
);
544 /* Writing them here to avoid exposing memcg's inner layout */
545 #if defined(CONFIG_INET) && defined(CONFIG_MEMCG_KMEM)
547 void sock_update_memcg(struct sock
*sk
)
549 if (mem_cgroup_sockets_enabled
) {
550 struct mem_cgroup
*memcg
;
551 struct cg_proto
*cg_proto
;
553 BUG_ON(!sk
->sk_prot
->proto_cgroup
);
555 /* Socket cloning can throw us here with sk_cgrp already
556 * filled. It won't however, necessarily happen from
557 * process context. So the test for root memcg given
558 * the current task's memcg won't help us in this case.
560 * Respecting the original socket's memcg is a better
561 * decision in this case.
564 BUG_ON(mem_cgroup_is_root(sk
->sk_cgrp
->memcg
));
565 css_get(&sk
->sk_cgrp
->memcg
->css
);
570 memcg
= mem_cgroup_from_task(current
);
571 cg_proto
= sk
->sk_prot
->proto_cgroup(memcg
);
572 if (!mem_cgroup_is_root(memcg
) &&
573 memcg_proto_active(cg_proto
) && css_tryget(&memcg
->css
)) {
574 sk
->sk_cgrp
= cg_proto
;
579 EXPORT_SYMBOL(sock_update_memcg
);
581 void sock_release_memcg(struct sock
*sk
)
583 if (mem_cgroup_sockets_enabled
&& sk
->sk_cgrp
) {
584 struct mem_cgroup
*memcg
;
585 WARN_ON(!sk
->sk_cgrp
->memcg
);
586 memcg
= sk
->sk_cgrp
->memcg
;
587 css_put(&sk
->sk_cgrp
->memcg
->css
);
591 struct cg_proto
*tcp_proto_cgroup(struct mem_cgroup
*memcg
)
593 if (!memcg
|| mem_cgroup_is_root(memcg
))
596 return &memcg
->tcp_mem
;
598 EXPORT_SYMBOL(tcp_proto_cgroup
);
600 static void disarm_sock_keys(struct mem_cgroup
*memcg
)
602 if (!memcg_proto_activated(&memcg
->tcp_mem
))
604 static_key_slow_dec(&memcg_socket_limit_enabled
);
607 static void disarm_sock_keys(struct mem_cgroup
*memcg
)
612 #ifdef CONFIG_MEMCG_KMEM
614 * This will be the memcg's index in each cache's ->memcg_params->memcg_caches.
615 * The main reason for not using cgroup id for this:
616 * this works better in sparse environments, where we have a lot of memcgs,
617 * but only a few kmem-limited. Or also, if we have, for instance, 200
618 * memcgs, and none but the 200th is kmem-limited, we'd have to have a
619 * 200 entry array for that.
621 * The current size of the caches array is stored in
622 * memcg_limited_groups_array_size. It will double each time we have to
625 static DEFINE_IDA(kmem_limited_groups
);
626 int memcg_limited_groups_array_size
;
629 * MIN_SIZE is different than 1, because we would like to avoid going through
630 * the alloc/free process all the time. In a small machine, 4 kmem-limited
631 * cgroups is a reasonable guess. In the future, it could be a parameter or
632 * tunable, but that is strictly not necessary.
634 * MAX_SIZE should be as large as the number of cgrp_ids. Ideally, we could get
635 * this constant directly from cgroup, but it is understandable that this is
636 * better kept as an internal representation in cgroup.c. In any case, the
637 * cgrp_id space is not getting any smaller, and we don't have to necessarily
638 * increase ours as well if it increases.
640 #define MEMCG_CACHES_MIN_SIZE 4
641 #define MEMCG_CACHES_MAX_SIZE MEM_CGROUP_ID_MAX
644 * A lot of the calls to the cache allocation functions are expected to be
645 * inlined by the compiler. Since the calls to memcg_kmem_get_cache are
646 * conditional to this static branch, we'll have to allow modules that does
647 * kmem_cache_alloc and the such to see this symbol as well
649 struct static_key memcg_kmem_enabled_key
;
650 EXPORT_SYMBOL(memcg_kmem_enabled_key
);
652 static void disarm_kmem_keys(struct mem_cgroup
*memcg
)
654 if (memcg_kmem_is_active(memcg
)) {
655 static_key_slow_dec(&memcg_kmem_enabled_key
);
656 ida_simple_remove(&kmem_limited_groups
, memcg
->kmemcg_id
);
659 * This check can't live in kmem destruction function,
660 * since the charges will outlive the cgroup
662 WARN_ON(res_counter_read_u64(&memcg
->kmem
, RES_USAGE
) != 0);
665 static void disarm_kmem_keys(struct mem_cgroup
*memcg
)
668 #endif /* CONFIG_MEMCG_KMEM */
670 static void disarm_static_keys(struct mem_cgroup
*memcg
)
672 disarm_sock_keys(memcg
);
673 disarm_kmem_keys(memcg
);
676 static void drain_all_stock_async(struct mem_cgroup
*memcg
);
678 static struct mem_cgroup_per_zone
*
679 mem_cgroup_zone_zoneinfo(struct mem_cgroup
*memcg
, struct zone
*zone
)
681 int nid
= zone_to_nid(zone
);
682 int zid
= zone_idx(zone
);
684 return &memcg
->nodeinfo
[nid
]->zoneinfo
[zid
];
687 struct cgroup_subsys_state
*mem_cgroup_css(struct mem_cgroup
*memcg
)
692 static struct mem_cgroup_per_zone
*
693 mem_cgroup_page_zoneinfo(struct mem_cgroup
*memcg
, struct page
*page
)
695 int nid
= page_to_nid(page
);
696 int zid
= page_zonenum(page
);
698 return &memcg
->nodeinfo
[nid
]->zoneinfo
[zid
];
701 static struct mem_cgroup_tree_per_zone
*
702 soft_limit_tree_node_zone(int nid
, int zid
)
704 return &soft_limit_tree
.rb_tree_per_node
[nid
]->rb_tree_per_zone
[zid
];
707 static struct mem_cgroup_tree_per_zone
*
708 soft_limit_tree_from_page(struct page
*page
)
710 int nid
= page_to_nid(page
);
711 int zid
= page_zonenum(page
);
713 return &soft_limit_tree
.rb_tree_per_node
[nid
]->rb_tree_per_zone
[zid
];
717 __mem_cgroup_insert_exceeded(struct mem_cgroup
*memcg
,
718 struct mem_cgroup_per_zone
*mz
,
719 struct mem_cgroup_tree_per_zone
*mctz
,
720 unsigned long long new_usage_in_excess
)
722 struct rb_node
**p
= &mctz
->rb_root
.rb_node
;
723 struct rb_node
*parent
= NULL
;
724 struct mem_cgroup_per_zone
*mz_node
;
729 mz
->usage_in_excess
= new_usage_in_excess
;
730 if (!mz
->usage_in_excess
)
734 mz_node
= rb_entry(parent
, struct mem_cgroup_per_zone
,
736 if (mz
->usage_in_excess
< mz_node
->usage_in_excess
)
739 * We can't avoid mem cgroups that are over their soft
740 * limit by the same amount
742 else if (mz
->usage_in_excess
>= mz_node
->usage_in_excess
)
745 rb_link_node(&mz
->tree_node
, parent
, p
);
746 rb_insert_color(&mz
->tree_node
, &mctz
->rb_root
);
751 __mem_cgroup_remove_exceeded(struct mem_cgroup
*memcg
,
752 struct mem_cgroup_per_zone
*mz
,
753 struct mem_cgroup_tree_per_zone
*mctz
)
757 rb_erase(&mz
->tree_node
, &mctz
->rb_root
);
762 mem_cgroup_remove_exceeded(struct mem_cgroup
*memcg
,
763 struct mem_cgroup_per_zone
*mz
,
764 struct mem_cgroup_tree_per_zone
*mctz
)
766 spin_lock(&mctz
->lock
);
767 __mem_cgroup_remove_exceeded(memcg
, mz
, mctz
);
768 spin_unlock(&mctz
->lock
);
772 static void mem_cgroup_update_tree(struct mem_cgroup
*memcg
, struct page
*page
)
774 unsigned long long excess
;
775 struct mem_cgroup_per_zone
*mz
;
776 struct mem_cgroup_tree_per_zone
*mctz
;
778 mctz
= soft_limit_tree_from_page(page
);
780 * Necessary to update all ancestors when hierarchy is used.
781 * because their event counter is not touched.
783 for (; memcg
; memcg
= parent_mem_cgroup(memcg
)) {
784 mz
= mem_cgroup_page_zoneinfo(memcg
, page
);
785 excess
= res_counter_soft_limit_excess(&memcg
->res
);
787 * We have to update the tree if mz is on RB-tree or
788 * mem is over its softlimit.
790 if (excess
|| mz
->on_tree
) {
791 spin_lock(&mctz
->lock
);
792 /* if on-tree, remove it */
794 __mem_cgroup_remove_exceeded(memcg
, mz
, mctz
);
796 * Insert again. mz->usage_in_excess will be updated.
797 * If excess is 0, no tree ops.
799 __mem_cgroup_insert_exceeded(memcg
, mz
, mctz
, excess
);
800 spin_unlock(&mctz
->lock
);
805 static void mem_cgroup_remove_from_trees(struct mem_cgroup
*memcg
)
807 struct mem_cgroup_tree_per_zone
*mctz
;
808 struct mem_cgroup_per_zone
*mz
;
812 for (zid
= 0; zid
< MAX_NR_ZONES
; zid
++) {
813 mz
= &memcg
->nodeinfo
[nid
]->zoneinfo
[zid
];
814 mctz
= soft_limit_tree_node_zone(nid
, zid
);
815 mem_cgroup_remove_exceeded(memcg
, mz
, mctz
);
820 static struct mem_cgroup_per_zone
*
821 __mem_cgroup_largest_soft_limit_node(struct mem_cgroup_tree_per_zone
*mctz
)
823 struct rb_node
*rightmost
= NULL
;
824 struct mem_cgroup_per_zone
*mz
;
828 rightmost
= rb_last(&mctz
->rb_root
);
830 goto done
; /* Nothing to reclaim from */
832 mz
= rb_entry(rightmost
, struct mem_cgroup_per_zone
, tree_node
);
834 * Remove the node now but someone else can add it back,
835 * we will to add it back at the end of reclaim to its correct
836 * position in the tree.
838 __mem_cgroup_remove_exceeded(mz
->memcg
, mz
, mctz
);
839 if (!res_counter_soft_limit_excess(&mz
->memcg
->res
) ||
840 !css_tryget(&mz
->memcg
->css
))
846 static struct mem_cgroup_per_zone
*
847 mem_cgroup_largest_soft_limit_node(struct mem_cgroup_tree_per_zone
*mctz
)
849 struct mem_cgroup_per_zone
*mz
;
851 spin_lock(&mctz
->lock
);
852 mz
= __mem_cgroup_largest_soft_limit_node(mctz
);
853 spin_unlock(&mctz
->lock
);
858 * Implementation Note: reading percpu statistics for memcg.
860 * Both of vmstat[] and percpu_counter has threshold and do periodic
861 * synchronization to implement "quick" read. There are trade-off between
862 * reading cost and precision of value. Then, we may have a chance to implement
863 * a periodic synchronizion of counter in memcg's counter.
865 * But this _read() function is used for user interface now. The user accounts
866 * memory usage by memory cgroup and he _always_ requires exact value because
867 * he accounts memory. Even if we provide quick-and-fuzzy read, we always
868 * have to visit all online cpus and make sum. So, for now, unnecessary
869 * synchronization is not implemented. (just implemented for cpu hotplug)
871 * If there are kernel internal actions which can make use of some not-exact
872 * value, and reading all cpu value can be performance bottleneck in some
873 * common workload, threashold and synchonization as vmstat[] should be
876 static long mem_cgroup_read_stat(struct mem_cgroup
*memcg
,
877 enum mem_cgroup_stat_index idx
)
883 for_each_online_cpu(cpu
)
884 val
+= per_cpu(memcg
->stat
->count
[idx
], cpu
);
885 #ifdef CONFIG_HOTPLUG_CPU
886 spin_lock(&memcg
->pcp_counter_lock
);
887 val
+= memcg
->nocpu_base
.count
[idx
];
888 spin_unlock(&memcg
->pcp_counter_lock
);
894 static void mem_cgroup_swap_statistics(struct mem_cgroup
*memcg
,
897 int val
= (charge
) ? 1 : -1;
898 this_cpu_add(memcg
->stat
->count
[MEM_CGROUP_STAT_SWAP
], val
);
901 static unsigned long mem_cgroup_read_events(struct mem_cgroup
*memcg
,
902 enum mem_cgroup_events_index idx
)
904 unsigned long val
= 0;
908 for_each_online_cpu(cpu
)
909 val
+= per_cpu(memcg
->stat
->events
[idx
], cpu
);
910 #ifdef CONFIG_HOTPLUG_CPU
911 spin_lock(&memcg
->pcp_counter_lock
);
912 val
+= memcg
->nocpu_base
.events
[idx
];
913 spin_unlock(&memcg
->pcp_counter_lock
);
919 static void mem_cgroup_charge_statistics(struct mem_cgroup
*memcg
,
921 bool anon
, int nr_pages
)
924 * Here, RSS means 'mapped anon' and anon's SwapCache. Shmem/tmpfs is
925 * counted as CACHE even if it's on ANON LRU.
928 __this_cpu_add(memcg
->stat
->count
[MEM_CGROUP_STAT_RSS
],
931 __this_cpu_add(memcg
->stat
->count
[MEM_CGROUP_STAT_CACHE
],
934 if (PageTransHuge(page
))
935 __this_cpu_add(memcg
->stat
->count
[MEM_CGROUP_STAT_RSS_HUGE
],
938 /* pagein of a big page is an event. So, ignore page size */
940 __this_cpu_inc(memcg
->stat
->events
[MEM_CGROUP_EVENTS_PGPGIN
]);
942 __this_cpu_inc(memcg
->stat
->events
[MEM_CGROUP_EVENTS_PGPGOUT
]);
943 nr_pages
= -nr_pages
; /* for event */
946 __this_cpu_add(memcg
->stat
->nr_page_events
, nr_pages
);
949 unsigned long mem_cgroup_get_lru_size(struct lruvec
*lruvec
, enum lru_list lru
)
951 struct mem_cgroup_per_zone
*mz
;
953 mz
= container_of(lruvec
, struct mem_cgroup_per_zone
, lruvec
);
954 return mz
->lru_size
[lru
];
957 static unsigned long mem_cgroup_node_nr_lru_pages(struct mem_cgroup
*memcg
,
959 unsigned int lru_mask
)
961 unsigned long nr
= 0;
964 VM_BUG_ON((unsigned)nid
>= nr_node_ids
);
966 for (zid
= 0; zid
< MAX_NR_ZONES
; zid
++) {
967 struct mem_cgroup_per_zone
*mz
;
971 if (!(BIT(lru
) & lru_mask
))
973 mz
= &memcg
->nodeinfo
[nid
]->zoneinfo
[zid
];
974 nr
+= mz
->lru_size
[lru
];
980 static unsigned long mem_cgroup_nr_lru_pages(struct mem_cgroup
*memcg
,
981 unsigned int lru_mask
)
983 unsigned long nr
= 0;
986 for_each_node_state(nid
, N_MEMORY
)
987 nr
+= mem_cgroup_node_nr_lru_pages(memcg
, nid
, lru_mask
);
991 static bool mem_cgroup_event_ratelimit(struct mem_cgroup
*memcg
,
992 enum mem_cgroup_events_target target
)
994 unsigned long val
, next
;
996 val
= __this_cpu_read(memcg
->stat
->nr_page_events
);
997 next
= __this_cpu_read(memcg
->stat
->targets
[target
]);
998 /* from time_after() in jiffies.h */
999 if ((long)next
- (long)val
< 0) {
1001 case MEM_CGROUP_TARGET_THRESH
:
1002 next
= val
+ THRESHOLDS_EVENTS_TARGET
;
1004 case MEM_CGROUP_TARGET_SOFTLIMIT
:
1005 next
= val
+ SOFTLIMIT_EVENTS_TARGET
;
1007 case MEM_CGROUP_TARGET_NUMAINFO
:
1008 next
= val
+ NUMAINFO_EVENTS_TARGET
;
1013 __this_cpu_write(memcg
->stat
->targets
[target
], next
);
1020 * Check events in order.
1023 static void memcg_check_events(struct mem_cgroup
*memcg
, struct page
*page
)
1026 /* threshold event is triggered in finer grain than soft limit */
1027 if (unlikely(mem_cgroup_event_ratelimit(memcg
,
1028 MEM_CGROUP_TARGET_THRESH
))) {
1030 bool do_numainfo __maybe_unused
;
1032 do_softlimit
= mem_cgroup_event_ratelimit(memcg
,
1033 MEM_CGROUP_TARGET_SOFTLIMIT
);
1034 #if MAX_NUMNODES > 1
1035 do_numainfo
= mem_cgroup_event_ratelimit(memcg
,
1036 MEM_CGROUP_TARGET_NUMAINFO
);
1040 mem_cgroup_threshold(memcg
);
1041 if (unlikely(do_softlimit
))
1042 mem_cgroup_update_tree(memcg
, page
);
1043 #if MAX_NUMNODES > 1
1044 if (unlikely(do_numainfo
))
1045 atomic_inc(&memcg
->numainfo_events
);
1051 struct mem_cgroup
*mem_cgroup_from_task(struct task_struct
*p
)
1054 * mm_update_next_owner() may clear mm->owner to NULL
1055 * if it races with swapoff, page migration, etc.
1056 * So this can be called with p == NULL.
1061 return mem_cgroup_from_css(task_css(p
, memory_cgrp_id
));
1064 static struct mem_cgroup
*get_mem_cgroup_from_mm(struct mm_struct
*mm
)
1066 struct mem_cgroup
*memcg
= NULL
;
1071 * Page cache insertions can happen withou an
1072 * actual mm context, e.g. during disk probing
1073 * on boot, loopback IO, acct() writes etc.
1076 memcg
= root_mem_cgroup
;
1078 memcg
= mem_cgroup_from_task(rcu_dereference(mm
->owner
));
1079 if (unlikely(!memcg
))
1080 memcg
= root_mem_cgroup
;
1082 } while (!css_tryget(&memcg
->css
));
1088 * Returns a next (in a pre-order walk) alive memcg (with elevated css
1089 * ref. count) or NULL if the whole root's subtree has been visited.
1091 * helper function to be used by mem_cgroup_iter
1093 static struct mem_cgroup
*__mem_cgroup_iter_next(struct mem_cgroup
*root
,
1094 struct mem_cgroup
*last_visited
)
1096 struct cgroup_subsys_state
*prev_css
, *next_css
;
1098 prev_css
= last_visited
? &last_visited
->css
: NULL
;
1100 next_css
= css_next_descendant_pre(prev_css
, &root
->css
);
1103 * Even if we found a group we have to make sure it is
1104 * alive. css && !memcg means that the groups should be
1105 * skipped and we should continue the tree walk.
1106 * last_visited css is safe to use because it is
1107 * protected by css_get and the tree walk is rcu safe.
1109 * We do not take a reference on the root of the tree walk
1110 * because we might race with the root removal when it would
1111 * be the only node in the iterated hierarchy and mem_cgroup_iter
1112 * would end up in an endless loop because it expects that at
1113 * least one valid node will be returned. Root cannot disappear
1114 * because caller of the iterator should hold it already so
1115 * skipping css reference should be safe.
1118 if ((next_css
== &root
->css
) ||
1119 ((next_css
->flags
& CSS_ONLINE
) && css_tryget(next_css
)))
1120 return mem_cgroup_from_css(next_css
);
1122 prev_css
= next_css
;
1129 static void mem_cgroup_iter_invalidate(struct mem_cgroup
*root
)
1132 * When a group in the hierarchy below root is destroyed, the
1133 * hierarchy iterator can no longer be trusted since it might
1134 * have pointed to the destroyed group. Invalidate it.
1136 atomic_inc(&root
->dead_count
);
1139 static struct mem_cgroup
*
1140 mem_cgroup_iter_load(struct mem_cgroup_reclaim_iter
*iter
,
1141 struct mem_cgroup
*root
,
1144 struct mem_cgroup
*position
= NULL
;
1146 * A cgroup destruction happens in two stages: offlining and
1147 * release. They are separated by a RCU grace period.
1149 * If the iterator is valid, we may still race with an
1150 * offlining. The RCU lock ensures the object won't be
1151 * released, tryget will fail if we lost the race.
1153 *sequence
= atomic_read(&root
->dead_count
);
1154 if (iter
->last_dead_count
== *sequence
) {
1156 position
= iter
->last_visited
;
1159 * We cannot take a reference to root because we might race
1160 * with root removal and returning NULL would end up in
1161 * an endless loop on the iterator user level when root
1162 * would be returned all the time.
1164 if (position
&& position
!= root
&&
1165 !css_tryget(&position
->css
))
1171 static void mem_cgroup_iter_update(struct mem_cgroup_reclaim_iter
*iter
,
1172 struct mem_cgroup
*last_visited
,
1173 struct mem_cgroup
*new_position
,
1174 struct mem_cgroup
*root
,
1177 /* root reference counting symmetric to mem_cgroup_iter_load */
1178 if (last_visited
&& last_visited
!= root
)
1179 css_put(&last_visited
->css
);
1181 * We store the sequence count from the time @last_visited was
1182 * loaded successfully instead of rereading it here so that we
1183 * don't lose destruction events in between. We could have
1184 * raced with the destruction of @new_position after all.
1186 iter
->last_visited
= new_position
;
1188 iter
->last_dead_count
= sequence
;
1192 * mem_cgroup_iter - iterate over memory cgroup hierarchy
1193 * @root: hierarchy root
1194 * @prev: previously returned memcg, NULL on first invocation
1195 * @reclaim: cookie for shared reclaim walks, NULL for full walks
1197 * Returns references to children of the hierarchy below @root, or
1198 * @root itself, or %NULL after a full round-trip.
1200 * Caller must pass the return value in @prev on subsequent
1201 * invocations for reference counting, or use mem_cgroup_iter_break()
1202 * to cancel a hierarchy walk before the round-trip is complete.
1204 * Reclaimers can specify a zone and a priority level in @reclaim to
1205 * divide up the memcgs in the hierarchy among all concurrent
1206 * reclaimers operating on the same zone and priority.
1208 struct mem_cgroup
*mem_cgroup_iter(struct mem_cgroup
*root
,
1209 struct mem_cgroup
*prev
,
1210 struct mem_cgroup_reclaim_cookie
*reclaim
)
1212 struct mem_cgroup
*memcg
= NULL
;
1213 struct mem_cgroup
*last_visited
= NULL
;
1215 if (mem_cgroup_disabled())
1219 root
= root_mem_cgroup
;
1221 if (prev
&& !reclaim
)
1222 last_visited
= prev
;
1224 if (!root
->use_hierarchy
&& root
!= root_mem_cgroup
) {
1232 struct mem_cgroup_reclaim_iter
*uninitialized_var(iter
);
1233 int uninitialized_var(seq
);
1236 struct mem_cgroup_per_zone
*mz
;
1238 mz
= mem_cgroup_zone_zoneinfo(root
, reclaim
->zone
);
1239 iter
= &mz
->reclaim_iter
[reclaim
->priority
];
1240 if (prev
&& reclaim
->generation
!= iter
->generation
) {
1241 iter
->last_visited
= NULL
;
1245 last_visited
= mem_cgroup_iter_load(iter
, root
, &seq
);
1248 memcg
= __mem_cgroup_iter_next(root
, last_visited
);
1251 mem_cgroup_iter_update(iter
, last_visited
, memcg
, root
,
1256 else if (!prev
&& memcg
)
1257 reclaim
->generation
= iter
->generation
;
1266 if (prev
&& prev
!= root
)
1267 css_put(&prev
->css
);
1273 * mem_cgroup_iter_break - abort a hierarchy walk prematurely
1274 * @root: hierarchy root
1275 * @prev: last visited hierarchy member as returned by mem_cgroup_iter()
1277 void mem_cgroup_iter_break(struct mem_cgroup
*root
,
1278 struct mem_cgroup
*prev
)
1281 root
= root_mem_cgroup
;
1282 if (prev
&& prev
!= root
)
1283 css_put(&prev
->css
);
1287 * Iteration constructs for visiting all cgroups (under a tree). If
1288 * loops are exited prematurely (break), mem_cgroup_iter_break() must
1289 * be used for reference counting.
1291 #define for_each_mem_cgroup_tree(iter, root) \
1292 for (iter = mem_cgroup_iter(root, NULL, NULL); \
1294 iter = mem_cgroup_iter(root, iter, NULL))
1296 #define for_each_mem_cgroup(iter) \
1297 for (iter = mem_cgroup_iter(NULL, NULL, NULL); \
1299 iter = mem_cgroup_iter(NULL, iter, NULL))
1301 void __mem_cgroup_count_vm_event(struct mm_struct
*mm
, enum vm_event_item idx
)
1303 struct mem_cgroup
*memcg
;
1306 memcg
= mem_cgroup_from_task(rcu_dereference(mm
->owner
));
1307 if (unlikely(!memcg
))
1312 this_cpu_inc(memcg
->stat
->events
[MEM_CGROUP_EVENTS_PGFAULT
]);
1315 this_cpu_inc(memcg
->stat
->events
[MEM_CGROUP_EVENTS_PGMAJFAULT
]);
1323 EXPORT_SYMBOL(__mem_cgroup_count_vm_event
);
1326 * mem_cgroup_zone_lruvec - get the lru list vector for a zone and memcg
1327 * @zone: zone of the wanted lruvec
1328 * @memcg: memcg of the wanted lruvec
1330 * Returns the lru list vector holding pages for the given @zone and
1331 * @mem. This can be the global zone lruvec, if the memory controller
1334 struct lruvec
*mem_cgroup_zone_lruvec(struct zone
*zone
,
1335 struct mem_cgroup
*memcg
)
1337 struct mem_cgroup_per_zone
*mz
;
1338 struct lruvec
*lruvec
;
1340 if (mem_cgroup_disabled()) {
1341 lruvec
= &zone
->lruvec
;
1345 mz
= mem_cgroup_zone_zoneinfo(memcg
, zone
);
1346 lruvec
= &mz
->lruvec
;
1349 * Since a node can be onlined after the mem_cgroup was created,
1350 * we have to be prepared to initialize lruvec->zone here;
1351 * and if offlined then reonlined, we need to reinitialize it.
1353 if (unlikely(lruvec
->zone
!= zone
))
1354 lruvec
->zone
= zone
;
1359 * Following LRU functions are allowed to be used without PCG_LOCK.
1360 * Operations are called by routine of global LRU independently from memcg.
1361 * What we have to take care of here is validness of pc->mem_cgroup.
1363 * Changes to pc->mem_cgroup happens when
1366 * In typical case, "charge" is done before add-to-lru. Exception is SwapCache.
1367 * It is added to LRU before charge.
1368 * If PCG_USED bit is not set, page_cgroup is not added to this private LRU.
1369 * When moving account, the page is not on LRU. It's isolated.
1373 * mem_cgroup_page_lruvec - return lruvec for adding an lru page
1375 * @zone: zone of the page
1377 struct lruvec
*mem_cgroup_page_lruvec(struct page
*page
, struct zone
*zone
)
1379 struct mem_cgroup_per_zone
*mz
;
1380 struct mem_cgroup
*memcg
;
1381 struct page_cgroup
*pc
;
1382 struct lruvec
*lruvec
;
1384 if (mem_cgroup_disabled()) {
1385 lruvec
= &zone
->lruvec
;
1389 pc
= lookup_page_cgroup(page
);
1390 memcg
= pc
->mem_cgroup
;
1393 * Surreptitiously switch any uncharged offlist page to root:
1394 * an uncharged page off lru does nothing to secure
1395 * its former mem_cgroup from sudden removal.
1397 * Our caller holds lru_lock, and PageCgroupUsed is updated
1398 * under page_cgroup lock: between them, they make all uses
1399 * of pc->mem_cgroup safe.
1401 if (!PageLRU(page
) && !PageCgroupUsed(pc
) && memcg
!= root_mem_cgroup
)
1402 pc
->mem_cgroup
= memcg
= root_mem_cgroup
;
1404 mz
= mem_cgroup_page_zoneinfo(memcg
, page
);
1405 lruvec
= &mz
->lruvec
;
1408 * Since a node can be onlined after the mem_cgroup was created,
1409 * we have to be prepared to initialize lruvec->zone here;
1410 * and if offlined then reonlined, we need to reinitialize it.
1412 if (unlikely(lruvec
->zone
!= zone
))
1413 lruvec
->zone
= zone
;
1418 * mem_cgroup_update_lru_size - account for adding or removing an lru page
1419 * @lruvec: mem_cgroup per zone lru vector
1420 * @lru: index of lru list the page is sitting on
1421 * @nr_pages: positive when adding or negative when removing
1423 * This function must be called when a page is added to or removed from an
1426 void mem_cgroup_update_lru_size(struct lruvec
*lruvec
, enum lru_list lru
,
1429 struct mem_cgroup_per_zone
*mz
;
1430 unsigned long *lru_size
;
1432 if (mem_cgroup_disabled())
1435 mz
= container_of(lruvec
, struct mem_cgroup_per_zone
, lruvec
);
1436 lru_size
= mz
->lru_size
+ lru
;
1437 *lru_size
+= nr_pages
;
1438 VM_BUG_ON((long)(*lru_size
) < 0);
1442 * Checks whether given mem is same or in the root_mem_cgroup's
1445 bool __mem_cgroup_same_or_subtree(const struct mem_cgroup
*root_memcg
,
1446 struct mem_cgroup
*memcg
)
1448 if (root_memcg
== memcg
)
1450 if (!root_memcg
->use_hierarchy
|| !memcg
)
1452 return cgroup_is_descendant(memcg
->css
.cgroup
, root_memcg
->css
.cgroup
);
1455 static bool mem_cgroup_same_or_subtree(const struct mem_cgroup
*root_memcg
,
1456 struct mem_cgroup
*memcg
)
1461 ret
= __mem_cgroup_same_or_subtree(root_memcg
, memcg
);
1466 bool task_in_mem_cgroup(struct task_struct
*task
,
1467 const struct mem_cgroup
*memcg
)
1469 struct mem_cgroup
*curr
= NULL
;
1470 struct task_struct
*p
;
1473 p
= find_lock_task_mm(task
);
1475 curr
= get_mem_cgroup_from_mm(p
->mm
);
1479 * All threads may have already detached their mm's, but the oom
1480 * killer still needs to detect if they have already been oom
1481 * killed to prevent needlessly killing additional tasks.
1484 curr
= mem_cgroup_from_task(task
);
1486 css_get(&curr
->css
);
1490 * We should check use_hierarchy of "memcg" not "curr". Because checking
1491 * use_hierarchy of "curr" here make this function true if hierarchy is
1492 * enabled in "curr" and "curr" is a child of "memcg" in *cgroup*
1493 * hierarchy(even if use_hierarchy is disabled in "memcg").
1495 ret
= mem_cgroup_same_or_subtree(memcg
, curr
);
1496 css_put(&curr
->css
);
1500 int mem_cgroup_inactive_anon_is_low(struct lruvec
*lruvec
)
1502 unsigned long inactive_ratio
;
1503 unsigned long inactive
;
1504 unsigned long active
;
1507 inactive
= mem_cgroup_get_lru_size(lruvec
, LRU_INACTIVE_ANON
);
1508 active
= mem_cgroup_get_lru_size(lruvec
, LRU_ACTIVE_ANON
);
1510 gb
= (inactive
+ active
) >> (30 - PAGE_SHIFT
);
1512 inactive_ratio
= int_sqrt(10 * gb
);
1516 return inactive
* inactive_ratio
< active
;
1519 #define mem_cgroup_from_res_counter(counter, member) \
1520 container_of(counter, struct mem_cgroup, member)
1523 * mem_cgroup_margin - calculate chargeable space of a memory cgroup
1524 * @memcg: the memory cgroup
1526 * Returns the maximum amount of memory @mem can be charged with, in
1529 static unsigned long mem_cgroup_margin(struct mem_cgroup
*memcg
)
1531 unsigned long long margin
;
1533 margin
= res_counter_margin(&memcg
->res
);
1534 if (do_swap_account
)
1535 margin
= min(margin
, res_counter_margin(&memcg
->memsw
));
1536 return margin
>> PAGE_SHIFT
;
1539 int mem_cgroup_swappiness(struct mem_cgroup
*memcg
)
1542 if (mem_cgroup_disabled() || !css_parent(&memcg
->css
))
1543 return vm_swappiness
;
1545 return memcg
->swappiness
;
1549 * memcg->moving_account is used for checking possibility that some thread is
1550 * calling move_account(). When a thread on CPU-A starts moving pages under
1551 * a memcg, other threads should check memcg->moving_account under
1552 * rcu_read_lock(), like this:
1556 * memcg->moving_account+1 if (memcg->mocing_account)
1558 * synchronize_rcu() update something.
1563 /* for quick checking without looking up memcg */
1564 atomic_t memcg_moving __read_mostly
;
1566 static void mem_cgroup_start_move(struct mem_cgroup
*memcg
)
1568 atomic_inc(&memcg_moving
);
1569 atomic_inc(&memcg
->moving_account
);
1573 static void mem_cgroup_end_move(struct mem_cgroup
*memcg
)
1576 * Now, mem_cgroup_clear_mc() may call this function with NULL.
1577 * We check NULL in callee rather than caller.
1580 atomic_dec(&memcg_moving
);
1581 atomic_dec(&memcg
->moving_account
);
1586 * A routine for checking "mem" is under move_account() or not.
1588 * Checking a cgroup is mc.from or mc.to or under hierarchy of
1589 * moving cgroups. This is for waiting at high-memory pressure
1592 static bool mem_cgroup_under_move(struct mem_cgroup
*memcg
)
1594 struct mem_cgroup
*from
;
1595 struct mem_cgroup
*to
;
1598 * Unlike task_move routines, we access mc.to, mc.from not under
1599 * mutual exclusion by cgroup_mutex. Here, we take spinlock instead.
1601 spin_lock(&mc
.lock
);
1607 ret
= mem_cgroup_same_or_subtree(memcg
, from
)
1608 || mem_cgroup_same_or_subtree(memcg
, to
);
1610 spin_unlock(&mc
.lock
);
1614 static bool mem_cgroup_wait_acct_move(struct mem_cgroup
*memcg
)
1616 if (mc
.moving_task
&& current
!= mc
.moving_task
) {
1617 if (mem_cgroup_under_move(memcg
)) {
1619 prepare_to_wait(&mc
.waitq
, &wait
, TASK_INTERRUPTIBLE
);
1620 /* moving charge context might have finished. */
1623 finish_wait(&mc
.waitq
, &wait
);
1631 * Take this lock when
1632 * - a code tries to modify page's memcg while it's USED.
1633 * - a code tries to modify page state accounting in a memcg.
1635 static void move_lock_mem_cgroup(struct mem_cgroup
*memcg
,
1636 unsigned long *flags
)
1638 spin_lock_irqsave(&memcg
->move_lock
, *flags
);
1641 static void move_unlock_mem_cgroup(struct mem_cgroup
*memcg
,
1642 unsigned long *flags
)
1644 spin_unlock_irqrestore(&memcg
->move_lock
, *flags
);
1647 #define K(x) ((x) << (PAGE_SHIFT-10))
1649 * mem_cgroup_print_oom_info: Print OOM information relevant to memory controller.
1650 * @memcg: The memory cgroup that went over limit
1651 * @p: Task that is going to be killed
1653 * NOTE: @memcg and @p's mem_cgroup can be different when hierarchy is
1656 void mem_cgroup_print_oom_info(struct mem_cgroup
*memcg
, struct task_struct
*p
)
1658 /* oom_info_lock ensures that parallel ooms do not interleave */
1659 static DEFINE_MUTEX(oom_info_lock
);
1660 struct mem_cgroup
*iter
;
1666 mutex_lock(&oom_info_lock
);
1669 pr_info("Task in ");
1670 pr_cont_cgroup_path(task_cgroup(p
, memory_cgrp_id
));
1671 pr_info(" killed as a result of limit of ");
1672 pr_cont_cgroup_path(memcg
->css
.cgroup
);
1677 pr_info("memory: usage %llukB, limit %llukB, failcnt %llu\n",
1678 res_counter_read_u64(&memcg
->res
, RES_USAGE
) >> 10,
1679 res_counter_read_u64(&memcg
->res
, RES_LIMIT
) >> 10,
1680 res_counter_read_u64(&memcg
->res
, RES_FAILCNT
));
1681 pr_info("memory+swap: usage %llukB, limit %llukB, failcnt %llu\n",
1682 res_counter_read_u64(&memcg
->memsw
, RES_USAGE
) >> 10,
1683 res_counter_read_u64(&memcg
->memsw
, RES_LIMIT
) >> 10,
1684 res_counter_read_u64(&memcg
->memsw
, RES_FAILCNT
));
1685 pr_info("kmem: usage %llukB, limit %llukB, failcnt %llu\n",
1686 res_counter_read_u64(&memcg
->kmem
, RES_USAGE
) >> 10,
1687 res_counter_read_u64(&memcg
->kmem
, RES_LIMIT
) >> 10,
1688 res_counter_read_u64(&memcg
->kmem
, RES_FAILCNT
));
1690 for_each_mem_cgroup_tree(iter
, memcg
) {
1691 pr_info("Memory cgroup stats for ");
1692 pr_cont_cgroup_path(iter
->css
.cgroup
);
1695 for (i
= 0; i
< MEM_CGROUP_STAT_NSTATS
; i
++) {
1696 if (i
== MEM_CGROUP_STAT_SWAP
&& !do_swap_account
)
1698 pr_cont(" %s:%ldKB", mem_cgroup_stat_names
[i
],
1699 K(mem_cgroup_read_stat(iter
, i
)));
1702 for (i
= 0; i
< NR_LRU_LISTS
; i
++)
1703 pr_cont(" %s:%luKB", mem_cgroup_lru_names
[i
],
1704 K(mem_cgroup_nr_lru_pages(iter
, BIT(i
))));
1708 mutex_unlock(&oom_info_lock
);
1712 * This function returns the number of memcg under hierarchy tree. Returns
1713 * 1(self count) if no children.
1715 static int mem_cgroup_count_children(struct mem_cgroup
*memcg
)
1718 struct mem_cgroup
*iter
;
1720 for_each_mem_cgroup_tree(iter
, memcg
)
1726 * Return the memory (and swap, if configured) limit for a memcg.
1728 static u64
mem_cgroup_get_limit(struct mem_cgroup
*memcg
)
1732 limit
= res_counter_read_u64(&memcg
->res
, RES_LIMIT
);
1735 * Do not consider swap space if we cannot swap due to swappiness
1737 if (mem_cgroup_swappiness(memcg
)) {
1740 limit
+= total_swap_pages
<< PAGE_SHIFT
;
1741 memsw
= res_counter_read_u64(&memcg
->memsw
, RES_LIMIT
);
1744 * If memsw is finite and limits the amount of swap space
1745 * available to this memcg, return that limit.
1747 limit
= min(limit
, memsw
);
1753 static void mem_cgroup_out_of_memory(struct mem_cgroup
*memcg
, gfp_t gfp_mask
,
1756 struct mem_cgroup
*iter
;
1757 unsigned long chosen_points
= 0;
1758 unsigned long totalpages
;
1759 unsigned int points
= 0;
1760 struct task_struct
*chosen
= NULL
;
1763 * If current has a pending SIGKILL or is exiting, then automatically
1764 * select it. The goal is to allow it to allocate so that it may
1765 * quickly exit and free its memory.
1767 if (fatal_signal_pending(current
) || current
->flags
& PF_EXITING
) {
1768 set_thread_flag(TIF_MEMDIE
);
1772 check_panic_on_oom(CONSTRAINT_MEMCG
, gfp_mask
, order
, NULL
);
1773 totalpages
= mem_cgroup_get_limit(memcg
) >> PAGE_SHIFT
? : 1;
1774 for_each_mem_cgroup_tree(iter
, memcg
) {
1775 struct css_task_iter it
;
1776 struct task_struct
*task
;
1778 css_task_iter_start(&iter
->css
, &it
);
1779 while ((task
= css_task_iter_next(&it
))) {
1780 switch (oom_scan_process_thread(task
, totalpages
, NULL
,
1782 case OOM_SCAN_SELECT
:
1784 put_task_struct(chosen
);
1786 chosen_points
= ULONG_MAX
;
1787 get_task_struct(chosen
);
1789 case OOM_SCAN_CONTINUE
:
1791 case OOM_SCAN_ABORT
:
1792 css_task_iter_end(&it
);
1793 mem_cgroup_iter_break(memcg
, iter
);
1795 put_task_struct(chosen
);
1800 points
= oom_badness(task
, memcg
, NULL
, totalpages
);
1801 if (!points
|| points
< chosen_points
)
1803 /* Prefer thread group leaders for display purposes */
1804 if (points
== chosen_points
&&
1805 thread_group_leader(chosen
))
1809 put_task_struct(chosen
);
1811 chosen_points
= points
;
1812 get_task_struct(chosen
);
1814 css_task_iter_end(&it
);
1819 points
= chosen_points
* 1000 / totalpages
;
1820 oom_kill_process(chosen
, gfp_mask
, order
, points
, totalpages
, memcg
,
1821 NULL
, "Memory cgroup out of memory");
1824 static unsigned long mem_cgroup_reclaim(struct mem_cgroup
*memcg
,
1826 unsigned long flags
)
1828 unsigned long total
= 0;
1829 bool noswap
= false;
1832 if (flags
& MEM_CGROUP_RECLAIM_NOSWAP
)
1834 if (!(flags
& MEM_CGROUP_RECLAIM_SHRINK
) && memcg
->memsw_is_minimum
)
1837 for (loop
= 0; loop
< MEM_CGROUP_MAX_RECLAIM_LOOPS
; loop
++) {
1839 drain_all_stock_async(memcg
);
1840 total
+= try_to_free_mem_cgroup_pages(memcg
, gfp_mask
, noswap
);
1842 * Allow limit shrinkers, which are triggered directly
1843 * by userspace, to catch signals and stop reclaim
1844 * after minimal progress, regardless of the margin.
1846 if (total
&& (flags
& MEM_CGROUP_RECLAIM_SHRINK
))
1848 if (mem_cgroup_margin(memcg
))
1851 * If nothing was reclaimed after two attempts, there
1852 * may be no reclaimable pages in this hierarchy.
1861 * test_mem_cgroup_node_reclaimable
1862 * @memcg: the target memcg
1863 * @nid: the node ID to be checked.
1864 * @noswap : specify true here if the user wants flle only information.
1866 * This function returns whether the specified memcg contains any
1867 * reclaimable pages on a node. Returns true if there are any reclaimable
1868 * pages in the node.
1870 static bool test_mem_cgroup_node_reclaimable(struct mem_cgroup
*memcg
,
1871 int nid
, bool noswap
)
1873 if (mem_cgroup_node_nr_lru_pages(memcg
, nid
, LRU_ALL_FILE
))
1875 if (noswap
|| !total_swap_pages
)
1877 if (mem_cgroup_node_nr_lru_pages(memcg
, nid
, LRU_ALL_ANON
))
1882 #if MAX_NUMNODES > 1
1885 * Always updating the nodemask is not very good - even if we have an empty
1886 * list or the wrong list here, we can start from some node and traverse all
1887 * nodes based on the zonelist. So update the list loosely once per 10 secs.
1890 static void mem_cgroup_may_update_nodemask(struct mem_cgroup
*memcg
)
1894 * numainfo_events > 0 means there was at least NUMAINFO_EVENTS_TARGET
1895 * pagein/pageout changes since the last update.
1897 if (!atomic_read(&memcg
->numainfo_events
))
1899 if (atomic_inc_return(&memcg
->numainfo_updating
) > 1)
1902 /* make a nodemask where this memcg uses memory from */
1903 memcg
->scan_nodes
= node_states
[N_MEMORY
];
1905 for_each_node_mask(nid
, node_states
[N_MEMORY
]) {
1907 if (!test_mem_cgroup_node_reclaimable(memcg
, nid
, false))
1908 node_clear(nid
, memcg
->scan_nodes
);
1911 atomic_set(&memcg
->numainfo_events
, 0);
1912 atomic_set(&memcg
->numainfo_updating
, 0);
1916 * Selecting a node where we start reclaim from. Because what we need is just
1917 * reducing usage counter, start from anywhere is O,K. Considering
1918 * memory reclaim from current node, there are pros. and cons.
1920 * Freeing memory from current node means freeing memory from a node which
1921 * we'll use or we've used. So, it may make LRU bad. And if several threads
1922 * hit limits, it will see a contention on a node. But freeing from remote
1923 * node means more costs for memory reclaim because of memory latency.
1925 * Now, we use round-robin. Better algorithm is welcomed.
1927 int mem_cgroup_select_victim_node(struct mem_cgroup
*memcg
)
1931 mem_cgroup_may_update_nodemask(memcg
);
1932 node
= memcg
->last_scanned_node
;
1934 node
= next_node(node
, memcg
->scan_nodes
);
1935 if (node
== MAX_NUMNODES
)
1936 node
= first_node(memcg
->scan_nodes
);
1938 * We call this when we hit limit, not when pages are added to LRU.
1939 * No LRU may hold pages because all pages are UNEVICTABLE or
1940 * memcg is too small and all pages are not on LRU. In that case,
1941 * we use curret node.
1943 if (unlikely(node
== MAX_NUMNODES
))
1944 node
= numa_node_id();
1946 memcg
->last_scanned_node
= node
;
1951 * Check all nodes whether it contains reclaimable pages or not.
1952 * For quick scan, we make use of scan_nodes. This will allow us to skip
1953 * unused nodes. But scan_nodes is lazily updated and may not cotain
1954 * enough new information. We need to do double check.
1956 static bool mem_cgroup_reclaimable(struct mem_cgroup
*memcg
, bool noswap
)
1961 * quick check...making use of scan_node.
1962 * We can skip unused nodes.
1964 if (!nodes_empty(memcg
->scan_nodes
)) {
1965 for (nid
= first_node(memcg
->scan_nodes
);
1967 nid
= next_node(nid
, memcg
->scan_nodes
)) {
1969 if (test_mem_cgroup_node_reclaimable(memcg
, nid
, noswap
))
1974 * Check rest of nodes.
1976 for_each_node_state(nid
, N_MEMORY
) {
1977 if (node_isset(nid
, memcg
->scan_nodes
))
1979 if (test_mem_cgroup_node_reclaimable(memcg
, nid
, noswap
))
1986 int mem_cgroup_select_victim_node(struct mem_cgroup
*memcg
)
1991 static bool mem_cgroup_reclaimable(struct mem_cgroup
*memcg
, bool noswap
)
1993 return test_mem_cgroup_node_reclaimable(memcg
, 0, noswap
);
1997 static int mem_cgroup_soft_reclaim(struct mem_cgroup
*root_memcg
,
2000 unsigned long *total_scanned
)
2002 struct mem_cgroup
*victim
= NULL
;
2005 unsigned long excess
;
2006 unsigned long nr_scanned
;
2007 struct mem_cgroup_reclaim_cookie reclaim
= {
2012 excess
= res_counter_soft_limit_excess(&root_memcg
->res
) >> PAGE_SHIFT
;
2015 victim
= mem_cgroup_iter(root_memcg
, victim
, &reclaim
);
2020 * If we have not been able to reclaim
2021 * anything, it might because there are
2022 * no reclaimable pages under this hierarchy
2027 * We want to do more targeted reclaim.
2028 * excess >> 2 is not to excessive so as to
2029 * reclaim too much, nor too less that we keep
2030 * coming back to reclaim from this cgroup
2032 if (total
>= (excess
>> 2) ||
2033 (loop
> MEM_CGROUP_MAX_RECLAIM_LOOPS
))
2038 if (!mem_cgroup_reclaimable(victim
, false))
2040 total
+= mem_cgroup_shrink_node_zone(victim
, gfp_mask
, false,
2042 *total_scanned
+= nr_scanned
;
2043 if (!res_counter_soft_limit_excess(&root_memcg
->res
))
2046 mem_cgroup_iter_break(root_memcg
, victim
);
2050 #ifdef CONFIG_LOCKDEP
2051 static struct lockdep_map memcg_oom_lock_dep_map
= {
2052 .name
= "memcg_oom_lock",
2056 static DEFINE_SPINLOCK(memcg_oom_lock
);
2059 * Check OOM-Killer is already running under our hierarchy.
2060 * If someone is running, return false.
2062 static bool mem_cgroup_oom_trylock(struct mem_cgroup
*memcg
)
2064 struct mem_cgroup
*iter
, *failed
= NULL
;
2066 spin_lock(&memcg_oom_lock
);
2068 for_each_mem_cgroup_tree(iter
, memcg
) {
2069 if (iter
->oom_lock
) {
2071 * this subtree of our hierarchy is already locked
2072 * so we cannot give a lock.
2075 mem_cgroup_iter_break(memcg
, iter
);
2078 iter
->oom_lock
= true;
2083 * OK, we failed to lock the whole subtree so we have
2084 * to clean up what we set up to the failing subtree
2086 for_each_mem_cgroup_tree(iter
, memcg
) {
2087 if (iter
== failed
) {
2088 mem_cgroup_iter_break(memcg
, iter
);
2091 iter
->oom_lock
= false;
2094 mutex_acquire(&memcg_oom_lock_dep_map
, 0, 1, _RET_IP_
);
2096 spin_unlock(&memcg_oom_lock
);
2101 static void mem_cgroup_oom_unlock(struct mem_cgroup
*memcg
)
2103 struct mem_cgroup
*iter
;
2105 spin_lock(&memcg_oom_lock
);
2106 mutex_release(&memcg_oom_lock_dep_map
, 1, _RET_IP_
);
2107 for_each_mem_cgroup_tree(iter
, memcg
)
2108 iter
->oom_lock
= false;
2109 spin_unlock(&memcg_oom_lock
);
2112 static void mem_cgroup_mark_under_oom(struct mem_cgroup
*memcg
)
2114 struct mem_cgroup
*iter
;
2116 for_each_mem_cgroup_tree(iter
, memcg
)
2117 atomic_inc(&iter
->under_oom
);
2120 static void mem_cgroup_unmark_under_oom(struct mem_cgroup
*memcg
)
2122 struct mem_cgroup
*iter
;
2125 * When a new child is created while the hierarchy is under oom,
2126 * mem_cgroup_oom_lock() may not be called. We have to use
2127 * atomic_add_unless() here.
2129 for_each_mem_cgroup_tree(iter
, memcg
)
2130 atomic_add_unless(&iter
->under_oom
, -1, 0);
2133 static DECLARE_WAIT_QUEUE_HEAD(memcg_oom_waitq
);
2135 struct oom_wait_info
{
2136 struct mem_cgroup
*memcg
;
2140 static int memcg_oom_wake_function(wait_queue_t
*wait
,
2141 unsigned mode
, int sync
, void *arg
)
2143 struct mem_cgroup
*wake_memcg
= (struct mem_cgroup
*)arg
;
2144 struct mem_cgroup
*oom_wait_memcg
;
2145 struct oom_wait_info
*oom_wait_info
;
2147 oom_wait_info
= container_of(wait
, struct oom_wait_info
, wait
);
2148 oom_wait_memcg
= oom_wait_info
->memcg
;
2151 * Both of oom_wait_info->memcg and wake_memcg are stable under us.
2152 * Then we can use css_is_ancestor without taking care of RCU.
2154 if (!mem_cgroup_same_or_subtree(oom_wait_memcg
, wake_memcg
)
2155 && !mem_cgroup_same_or_subtree(wake_memcg
, oom_wait_memcg
))
2157 return autoremove_wake_function(wait
, mode
, sync
, arg
);
2160 static void memcg_wakeup_oom(struct mem_cgroup
*memcg
)
2162 atomic_inc(&memcg
->oom_wakeups
);
2163 /* for filtering, pass "memcg" as argument. */
2164 __wake_up(&memcg_oom_waitq
, TASK_NORMAL
, 0, memcg
);
2167 static void memcg_oom_recover(struct mem_cgroup
*memcg
)
2169 if (memcg
&& atomic_read(&memcg
->under_oom
))
2170 memcg_wakeup_oom(memcg
);
2173 static void mem_cgroup_oom(struct mem_cgroup
*memcg
, gfp_t mask
, int order
)
2175 if (!current
->memcg_oom
.may_oom
)
2178 * We are in the middle of the charge context here, so we
2179 * don't want to block when potentially sitting on a callstack
2180 * that holds all kinds of filesystem and mm locks.
2182 * Also, the caller may handle a failed allocation gracefully
2183 * (like optional page cache readahead) and so an OOM killer
2184 * invocation might not even be necessary.
2186 * That's why we don't do anything here except remember the
2187 * OOM context and then deal with it at the end of the page
2188 * fault when the stack is unwound, the locks are released,
2189 * and when we know whether the fault was overall successful.
2191 css_get(&memcg
->css
);
2192 current
->memcg_oom
.memcg
= memcg
;
2193 current
->memcg_oom
.gfp_mask
= mask
;
2194 current
->memcg_oom
.order
= order
;
2198 * mem_cgroup_oom_synchronize - complete memcg OOM handling
2199 * @handle: actually kill/wait or just clean up the OOM state
2201 * This has to be called at the end of a page fault if the memcg OOM
2202 * handler was enabled.
2204 * Memcg supports userspace OOM handling where failed allocations must
2205 * sleep on a waitqueue until the userspace task resolves the
2206 * situation. Sleeping directly in the charge context with all kinds
2207 * of locks held is not a good idea, instead we remember an OOM state
2208 * in the task and mem_cgroup_oom_synchronize() has to be called at
2209 * the end of the page fault to complete the OOM handling.
2211 * Returns %true if an ongoing memcg OOM situation was detected and
2212 * completed, %false otherwise.
2214 bool mem_cgroup_oom_synchronize(bool handle
)
2216 struct mem_cgroup
*memcg
= current
->memcg_oom
.memcg
;
2217 struct oom_wait_info owait
;
2220 /* OOM is global, do not handle */
2227 owait
.memcg
= memcg
;
2228 owait
.wait
.flags
= 0;
2229 owait
.wait
.func
= memcg_oom_wake_function
;
2230 owait
.wait
.private = current
;
2231 INIT_LIST_HEAD(&owait
.wait
.task_list
);
2233 prepare_to_wait(&memcg_oom_waitq
, &owait
.wait
, TASK_KILLABLE
);
2234 mem_cgroup_mark_under_oom(memcg
);
2236 locked
= mem_cgroup_oom_trylock(memcg
);
2239 mem_cgroup_oom_notify(memcg
);
2241 if (locked
&& !memcg
->oom_kill_disable
) {
2242 mem_cgroup_unmark_under_oom(memcg
);
2243 finish_wait(&memcg_oom_waitq
, &owait
.wait
);
2244 mem_cgroup_out_of_memory(memcg
, current
->memcg_oom
.gfp_mask
,
2245 current
->memcg_oom
.order
);
2248 mem_cgroup_unmark_under_oom(memcg
);
2249 finish_wait(&memcg_oom_waitq
, &owait
.wait
);
2253 mem_cgroup_oom_unlock(memcg
);
2255 * There is no guarantee that an OOM-lock contender
2256 * sees the wakeups triggered by the OOM kill
2257 * uncharges. Wake any sleepers explicitely.
2259 memcg_oom_recover(memcg
);
2262 current
->memcg_oom
.memcg
= NULL
;
2263 css_put(&memcg
->css
);
2268 * Used to update mapped file or writeback or other statistics.
2270 * Notes: Race condition
2272 * We usually use lock_page_cgroup() for accessing page_cgroup member but
2273 * it tends to be costly. But considering some conditions, we doesn't need
2274 * to do so _always_.
2276 * Considering "charge", lock_page_cgroup() is not required because all
2277 * file-stat operations happen after a page is attached to radix-tree. There
2278 * are no race with "charge".
2280 * Considering "uncharge", we know that memcg doesn't clear pc->mem_cgroup
2281 * at "uncharge" intentionally. So, we always see valid pc->mem_cgroup even
2282 * if there are race with "uncharge". Statistics itself is properly handled
2285 * Considering "move", this is an only case we see a race. To make the race
2286 * small, we check memcg->moving_account and detect there are possibility
2287 * of race or not. If there is, we take a lock.
2290 void __mem_cgroup_begin_update_page_stat(struct page
*page
,
2291 bool *locked
, unsigned long *flags
)
2293 struct mem_cgroup
*memcg
;
2294 struct page_cgroup
*pc
;
2296 pc
= lookup_page_cgroup(page
);
2298 memcg
= pc
->mem_cgroup
;
2299 if (unlikely(!memcg
|| !PageCgroupUsed(pc
)))
2302 * If this memory cgroup is not under account moving, we don't
2303 * need to take move_lock_mem_cgroup(). Because we already hold
2304 * rcu_read_lock(), any calls to move_account will be delayed until
2305 * rcu_read_unlock().
2307 VM_BUG_ON(!rcu_read_lock_held());
2308 if (atomic_read(&memcg
->moving_account
) <= 0)
2311 move_lock_mem_cgroup(memcg
, flags
);
2312 if (memcg
!= pc
->mem_cgroup
|| !PageCgroupUsed(pc
)) {
2313 move_unlock_mem_cgroup(memcg
, flags
);
2319 void __mem_cgroup_end_update_page_stat(struct page
*page
, unsigned long *flags
)
2321 struct page_cgroup
*pc
= lookup_page_cgroup(page
);
2324 * It's guaranteed that pc->mem_cgroup never changes while
2325 * lock is held because a routine modifies pc->mem_cgroup
2326 * should take move_lock_mem_cgroup().
2328 move_unlock_mem_cgroup(pc
->mem_cgroup
, flags
);
2331 void mem_cgroup_update_page_stat(struct page
*page
,
2332 enum mem_cgroup_stat_index idx
, int val
)
2334 struct mem_cgroup
*memcg
;
2335 struct page_cgroup
*pc
= lookup_page_cgroup(page
);
2336 unsigned long uninitialized_var(flags
);
2338 if (mem_cgroup_disabled())
2341 VM_BUG_ON(!rcu_read_lock_held());
2342 memcg
= pc
->mem_cgroup
;
2343 if (unlikely(!memcg
|| !PageCgroupUsed(pc
)))
2346 this_cpu_add(memcg
->stat
->count
[idx
], val
);
2350 * size of first charge trial. "32" comes from vmscan.c's magic value.
2351 * TODO: maybe necessary to use big numbers in big irons.
2353 #define CHARGE_BATCH 32U
2354 struct memcg_stock_pcp
{
2355 struct mem_cgroup
*cached
; /* this never be root cgroup */
2356 unsigned int nr_pages
;
2357 struct work_struct work
;
2358 unsigned long flags
;
2359 #define FLUSHING_CACHED_CHARGE 0
2361 static DEFINE_PER_CPU(struct memcg_stock_pcp
, memcg_stock
);
2362 static DEFINE_MUTEX(percpu_charge_mutex
);
2365 * consume_stock: Try to consume stocked charge on this cpu.
2366 * @memcg: memcg to consume from.
2367 * @nr_pages: how many pages to charge.
2369 * The charges will only happen if @memcg matches the current cpu's memcg
2370 * stock, and at least @nr_pages are available in that stock. Failure to
2371 * service an allocation will refill the stock.
2373 * returns true if successful, false otherwise.
2375 static bool consume_stock(struct mem_cgroup
*memcg
, unsigned int nr_pages
)
2377 struct memcg_stock_pcp
*stock
;
2380 if (nr_pages
> CHARGE_BATCH
)
2383 stock
= &get_cpu_var(memcg_stock
);
2384 if (memcg
== stock
->cached
&& stock
->nr_pages
>= nr_pages
)
2385 stock
->nr_pages
-= nr_pages
;
2386 else /* need to call res_counter_charge */
2388 put_cpu_var(memcg_stock
);
2393 * Returns stocks cached in percpu to res_counter and reset cached information.
2395 static void drain_stock(struct memcg_stock_pcp
*stock
)
2397 struct mem_cgroup
*old
= stock
->cached
;
2399 if (stock
->nr_pages
) {
2400 unsigned long bytes
= stock
->nr_pages
* PAGE_SIZE
;
2402 res_counter_uncharge(&old
->res
, bytes
);
2403 if (do_swap_account
)
2404 res_counter_uncharge(&old
->memsw
, bytes
);
2405 stock
->nr_pages
= 0;
2407 stock
->cached
= NULL
;
2411 * This must be called under preempt disabled or must be called by
2412 * a thread which is pinned to local cpu.
2414 static void drain_local_stock(struct work_struct
*dummy
)
2416 struct memcg_stock_pcp
*stock
= this_cpu_ptr(&memcg_stock
);
2418 clear_bit(FLUSHING_CACHED_CHARGE
, &stock
->flags
);
2421 static void __init
memcg_stock_init(void)
2425 for_each_possible_cpu(cpu
) {
2426 struct memcg_stock_pcp
*stock
=
2427 &per_cpu(memcg_stock
, cpu
);
2428 INIT_WORK(&stock
->work
, drain_local_stock
);
2433 * Cache charges(val) which is from res_counter, to local per_cpu area.
2434 * This will be consumed by consume_stock() function, later.
2436 static void refill_stock(struct mem_cgroup
*memcg
, unsigned int nr_pages
)
2438 struct memcg_stock_pcp
*stock
= &get_cpu_var(memcg_stock
);
2440 if (stock
->cached
!= memcg
) { /* reset if necessary */
2442 stock
->cached
= memcg
;
2444 stock
->nr_pages
+= nr_pages
;
2445 put_cpu_var(memcg_stock
);
2449 * Drains all per-CPU charge caches for given root_memcg resp. subtree
2450 * of the hierarchy under it. sync flag says whether we should block
2451 * until the work is done.
2453 static void drain_all_stock(struct mem_cgroup
*root_memcg
, bool sync
)
2457 /* Notify other cpus that system-wide "drain" is running */
2460 for_each_online_cpu(cpu
) {
2461 struct memcg_stock_pcp
*stock
= &per_cpu(memcg_stock
, cpu
);
2462 struct mem_cgroup
*memcg
;
2464 memcg
= stock
->cached
;
2465 if (!memcg
|| !stock
->nr_pages
)
2467 if (!mem_cgroup_same_or_subtree(root_memcg
, memcg
))
2469 if (!test_and_set_bit(FLUSHING_CACHED_CHARGE
, &stock
->flags
)) {
2471 drain_local_stock(&stock
->work
);
2473 schedule_work_on(cpu
, &stock
->work
);
2481 for_each_online_cpu(cpu
) {
2482 struct memcg_stock_pcp
*stock
= &per_cpu(memcg_stock
, cpu
);
2483 if (test_bit(FLUSHING_CACHED_CHARGE
, &stock
->flags
))
2484 flush_work(&stock
->work
);
2491 * Tries to drain stocked charges in other cpus. This function is asynchronous
2492 * and just put a work per cpu for draining localy on each cpu. Caller can
2493 * expects some charges will be back to res_counter later but cannot wait for
2496 static void drain_all_stock_async(struct mem_cgroup
*root_memcg
)
2499 * If someone calls draining, avoid adding more kworker runs.
2501 if (!mutex_trylock(&percpu_charge_mutex
))
2503 drain_all_stock(root_memcg
, false);
2504 mutex_unlock(&percpu_charge_mutex
);
2507 /* This is a synchronous drain interface. */
2508 static void drain_all_stock_sync(struct mem_cgroup
*root_memcg
)
2510 /* called when force_empty is called */
2511 mutex_lock(&percpu_charge_mutex
);
2512 drain_all_stock(root_memcg
, true);
2513 mutex_unlock(&percpu_charge_mutex
);
2517 * This function drains percpu counter value from DEAD cpu and
2518 * move it to local cpu. Note that this function can be preempted.
2520 static void mem_cgroup_drain_pcp_counter(struct mem_cgroup
*memcg
, int cpu
)
2524 spin_lock(&memcg
->pcp_counter_lock
);
2525 for (i
= 0; i
< MEM_CGROUP_STAT_NSTATS
; i
++) {
2526 long x
= per_cpu(memcg
->stat
->count
[i
], cpu
);
2528 per_cpu(memcg
->stat
->count
[i
], cpu
) = 0;
2529 memcg
->nocpu_base
.count
[i
] += x
;
2531 for (i
= 0; i
< MEM_CGROUP_EVENTS_NSTATS
; i
++) {
2532 unsigned long x
= per_cpu(memcg
->stat
->events
[i
], cpu
);
2534 per_cpu(memcg
->stat
->events
[i
], cpu
) = 0;
2535 memcg
->nocpu_base
.events
[i
] += x
;
2537 spin_unlock(&memcg
->pcp_counter_lock
);
2540 static int memcg_cpu_hotplug_callback(struct notifier_block
*nb
,
2541 unsigned long action
,
2544 int cpu
= (unsigned long)hcpu
;
2545 struct memcg_stock_pcp
*stock
;
2546 struct mem_cgroup
*iter
;
2548 if (action
== CPU_ONLINE
)
2551 if (action
!= CPU_DEAD
&& action
!= CPU_DEAD_FROZEN
)
2554 for_each_mem_cgroup(iter
)
2555 mem_cgroup_drain_pcp_counter(iter
, cpu
);
2557 stock
= &per_cpu(memcg_stock
, cpu
);
2563 /* See mem_cgroup_try_charge() for details */
2565 CHARGE_OK
, /* success */
2566 CHARGE_RETRY
, /* need to retry but retry is not bad */
2567 CHARGE_NOMEM
, /* we can't do more. return -ENOMEM */
2568 CHARGE_WOULDBLOCK
, /* GFP_WAIT wasn't set and no enough res. */
2571 static int mem_cgroup_do_charge(struct mem_cgroup
*memcg
, gfp_t gfp_mask
,
2572 unsigned int nr_pages
, unsigned int min_pages
,
2575 unsigned long csize
= nr_pages
* PAGE_SIZE
;
2576 struct mem_cgroup
*mem_over_limit
;
2577 struct res_counter
*fail_res
;
2578 unsigned long flags
= 0;
2581 ret
= res_counter_charge(&memcg
->res
, csize
, &fail_res
);
2584 if (!do_swap_account
)
2586 ret
= res_counter_charge(&memcg
->memsw
, csize
, &fail_res
);
2590 res_counter_uncharge(&memcg
->res
, csize
);
2591 mem_over_limit
= mem_cgroup_from_res_counter(fail_res
, memsw
);
2592 flags
|= MEM_CGROUP_RECLAIM_NOSWAP
;
2594 mem_over_limit
= mem_cgroup_from_res_counter(fail_res
, res
);
2596 * Never reclaim on behalf of optional batching, retry with a
2597 * single page instead.
2599 if (nr_pages
> min_pages
)
2600 return CHARGE_RETRY
;
2602 if (!(gfp_mask
& __GFP_WAIT
))
2603 return CHARGE_WOULDBLOCK
;
2605 if (gfp_mask
& __GFP_NORETRY
)
2606 return CHARGE_NOMEM
;
2608 ret
= mem_cgroup_reclaim(mem_over_limit
, gfp_mask
, flags
);
2609 if (mem_cgroup_margin(mem_over_limit
) >= nr_pages
)
2610 return CHARGE_RETRY
;
2612 * Even though the limit is exceeded at this point, reclaim
2613 * may have been able to free some pages. Retry the charge
2614 * before killing the task.
2616 * Only for regular pages, though: huge pages are rather
2617 * unlikely to succeed so close to the limit, and we fall back
2618 * to regular pages anyway in case of failure.
2620 if (nr_pages
<= (1 << PAGE_ALLOC_COSTLY_ORDER
) && ret
)
2621 return CHARGE_RETRY
;
2624 * At task move, charge accounts can be doubly counted. So, it's
2625 * better to wait until the end of task_move if something is going on.
2627 if (mem_cgroup_wait_acct_move(mem_over_limit
))
2628 return CHARGE_RETRY
;
2631 mem_cgroup_oom(mem_over_limit
, gfp_mask
, get_order(csize
));
2633 return CHARGE_NOMEM
;
2637 * mem_cgroup_try_charge - try charging a memcg
2638 * @memcg: memcg to charge
2639 * @nr_pages: number of pages to charge
2640 * @oom: trigger OOM if reclaim fails
2642 * Returns 0 if @memcg was charged successfully, -EINTR if the charge
2643 * was bypassed to root_mem_cgroup, and -ENOMEM if the charge failed.
2645 static int mem_cgroup_try_charge(struct mem_cgroup
*memcg
,
2647 unsigned int nr_pages
,
2650 unsigned int batch
= max(CHARGE_BATCH
, nr_pages
);
2651 int nr_oom_retries
= MEM_CGROUP_RECLAIM_RETRIES
;
2654 if (mem_cgroup_is_root(memcg
))
2657 * Unlike in global OOM situations, memcg is not in a physical
2658 * memory shortage. Allow dying and OOM-killed tasks to
2659 * bypass the last charges so that they can exit quickly and
2660 * free their memory.
2662 if (unlikely(test_thread_flag(TIF_MEMDIE
) ||
2663 fatal_signal_pending(current
) ||
2664 current
->flags
& PF_EXITING
))
2667 if (unlikely(task_in_memcg_oom(current
)))
2670 if (gfp_mask
& __GFP_NOFAIL
)
2673 if (consume_stock(memcg
, nr_pages
))
2677 bool invoke_oom
= oom
&& !nr_oom_retries
;
2679 /* If killed, bypass charge */
2680 if (fatal_signal_pending(current
))
2683 ret
= mem_cgroup_do_charge(memcg
, gfp_mask
, batch
,
2684 nr_pages
, invoke_oom
);
2688 case CHARGE_RETRY
: /* not in OOM situation but retry */
2691 case CHARGE_WOULDBLOCK
: /* !__GFP_WAIT */
2693 case CHARGE_NOMEM
: /* OOM routine works */
2694 if (!oom
|| invoke_oom
)
2699 } while (ret
!= CHARGE_OK
);
2701 if (batch
> nr_pages
)
2702 refill_stock(memcg
, batch
- nr_pages
);
2706 if (!(gfp_mask
& __GFP_NOFAIL
))
2713 * mem_cgroup_try_charge_mm - try charging a mm
2714 * @mm: mm_struct to charge
2715 * @nr_pages: number of pages to charge
2716 * @oom: trigger OOM if reclaim fails
2718 * Returns the charged mem_cgroup associated with the given mm_struct or
2719 * NULL the charge failed.
2721 static struct mem_cgroup
*mem_cgroup_try_charge_mm(struct mm_struct
*mm
,
2723 unsigned int nr_pages
,
2727 struct mem_cgroup
*memcg
;
2730 memcg
= get_mem_cgroup_from_mm(mm
);
2731 ret
= mem_cgroup_try_charge(memcg
, gfp_mask
, nr_pages
, oom
);
2732 css_put(&memcg
->css
);
2734 memcg
= root_mem_cgroup
;
2742 * Somemtimes we have to undo a charge we got by try_charge().
2743 * This function is for that and do uncharge, put css's refcnt.
2744 * gotten by try_charge().
2746 static void __mem_cgroup_cancel_charge(struct mem_cgroup
*memcg
,
2747 unsigned int nr_pages
)
2749 if (!mem_cgroup_is_root(memcg
)) {
2750 unsigned long bytes
= nr_pages
* PAGE_SIZE
;
2752 res_counter_uncharge(&memcg
->res
, bytes
);
2753 if (do_swap_account
)
2754 res_counter_uncharge(&memcg
->memsw
, bytes
);
2759 * Cancel chrages in this cgroup....doesn't propagate to parent cgroup.
2760 * This is useful when moving usage to parent cgroup.
2762 static void __mem_cgroup_cancel_local_charge(struct mem_cgroup
*memcg
,
2763 unsigned int nr_pages
)
2765 unsigned long bytes
= nr_pages
* PAGE_SIZE
;
2767 if (mem_cgroup_is_root(memcg
))
2770 res_counter_uncharge_until(&memcg
->res
, memcg
->res
.parent
, bytes
);
2771 if (do_swap_account
)
2772 res_counter_uncharge_until(&memcg
->memsw
,
2773 memcg
->memsw
.parent
, bytes
);
2777 * A helper function to get mem_cgroup from ID. must be called under
2778 * rcu_read_lock(). The caller is responsible for calling css_tryget if
2779 * the mem_cgroup is used for charging. (dropping refcnt from swap can be
2780 * called against removed memcg.)
2782 static struct mem_cgroup
*mem_cgroup_lookup(unsigned short id
)
2784 /* ID 0 is unused ID */
2787 return mem_cgroup_from_id(id
);
2790 struct mem_cgroup
*try_get_mem_cgroup_from_page(struct page
*page
)
2792 struct mem_cgroup
*memcg
= NULL
;
2793 struct page_cgroup
*pc
;
2797 VM_BUG_ON_PAGE(!PageLocked(page
), page
);
2799 pc
= lookup_page_cgroup(page
);
2800 lock_page_cgroup(pc
);
2801 if (PageCgroupUsed(pc
)) {
2802 memcg
= pc
->mem_cgroup
;
2803 if (memcg
&& !css_tryget(&memcg
->css
))
2805 } else if (PageSwapCache(page
)) {
2806 ent
.val
= page_private(page
);
2807 id
= lookup_swap_cgroup_id(ent
);
2809 memcg
= mem_cgroup_lookup(id
);
2810 if (memcg
&& !css_tryget(&memcg
->css
))
2814 unlock_page_cgroup(pc
);
2818 static void __mem_cgroup_commit_charge(struct mem_cgroup
*memcg
,
2820 unsigned int nr_pages
,
2821 enum charge_type ctype
,
2824 struct page_cgroup
*pc
= lookup_page_cgroup(page
);
2825 struct zone
*uninitialized_var(zone
);
2826 struct lruvec
*lruvec
;
2827 bool was_on_lru
= false;
2830 lock_page_cgroup(pc
);
2831 VM_BUG_ON_PAGE(PageCgroupUsed(pc
), page
);
2833 * we don't need page_cgroup_lock about tail pages, becase they are not
2834 * accessed by any other context at this point.
2838 * In some cases, SwapCache and FUSE(splice_buf->radixtree), the page
2839 * may already be on some other mem_cgroup's LRU. Take care of it.
2842 zone
= page_zone(page
);
2843 spin_lock_irq(&zone
->lru_lock
);
2844 if (PageLRU(page
)) {
2845 lruvec
= mem_cgroup_zone_lruvec(zone
, pc
->mem_cgroup
);
2847 del_page_from_lru_list(page
, lruvec
, page_lru(page
));
2852 pc
->mem_cgroup
= memcg
;
2854 * We access a page_cgroup asynchronously without lock_page_cgroup().
2855 * Especially when a page_cgroup is taken from a page, pc->mem_cgroup
2856 * is accessed after testing USED bit. To make pc->mem_cgroup visible
2857 * before USED bit, we need memory barrier here.
2858 * See mem_cgroup_add_lru_list(), etc.
2861 SetPageCgroupUsed(pc
);
2865 lruvec
= mem_cgroup_zone_lruvec(zone
, pc
->mem_cgroup
);
2866 VM_BUG_ON_PAGE(PageLRU(page
), page
);
2868 add_page_to_lru_list(page
, lruvec
, page_lru(page
));
2870 spin_unlock_irq(&zone
->lru_lock
);
2873 if (ctype
== MEM_CGROUP_CHARGE_TYPE_ANON
)
2878 mem_cgroup_charge_statistics(memcg
, page
, anon
, nr_pages
);
2879 unlock_page_cgroup(pc
);
2882 * "charge_statistics" updated event counter. Then, check it.
2883 * Insert ancestor (and ancestor's ancestors), to softlimit RB-tree.
2884 * if they exceeds softlimit.
2886 memcg_check_events(memcg
, page
);
2889 static DEFINE_MUTEX(set_limit_mutex
);
2891 #ifdef CONFIG_MEMCG_KMEM
2893 * The memcg_slab_mutex is held whenever a per memcg kmem cache is created or
2894 * destroyed. It protects memcg_caches arrays and memcg_slab_caches lists.
2896 static DEFINE_MUTEX(memcg_slab_mutex
);
2898 static DEFINE_MUTEX(activate_kmem_mutex
);
2900 static inline bool memcg_can_account_kmem(struct mem_cgroup
*memcg
)
2902 return !mem_cgroup_disabled() && !mem_cgroup_is_root(memcg
) &&
2903 memcg_kmem_is_active(memcg
);
2907 * This is a bit cumbersome, but it is rarely used and avoids a backpointer
2908 * in the memcg_cache_params struct.
2910 static struct kmem_cache
*memcg_params_to_cache(struct memcg_cache_params
*p
)
2912 struct kmem_cache
*cachep
;
2914 VM_BUG_ON(p
->is_root_cache
);
2915 cachep
= p
->root_cache
;
2916 return cache_from_memcg_idx(cachep
, memcg_cache_id(p
->memcg
));
2919 #ifdef CONFIG_SLABINFO
2920 static int mem_cgroup_slabinfo_read(struct seq_file
*m
, void *v
)
2922 struct mem_cgroup
*memcg
= mem_cgroup_from_css(seq_css(m
));
2923 struct memcg_cache_params
*params
;
2925 if (!memcg_can_account_kmem(memcg
))
2928 print_slabinfo_header(m
);
2930 mutex_lock(&memcg_slab_mutex
);
2931 list_for_each_entry(params
, &memcg
->memcg_slab_caches
, list
)
2932 cache_show(memcg_params_to_cache(params
), m
);
2933 mutex_unlock(&memcg_slab_mutex
);
2939 static int memcg_charge_kmem(struct mem_cgroup
*memcg
, gfp_t gfp
, u64 size
)
2941 struct res_counter
*fail_res
;
2944 ret
= res_counter_charge(&memcg
->kmem
, size
, &fail_res
);
2948 ret
= mem_cgroup_try_charge(memcg
, gfp
, size
>> PAGE_SHIFT
,
2949 oom_gfp_allowed(gfp
));
2950 if (ret
== -EINTR
) {
2952 * mem_cgroup_try_charge() chosed to bypass to root due to
2953 * OOM kill or fatal signal. Since our only options are to
2954 * either fail the allocation or charge it to this cgroup, do
2955 * it as a temporary condition. But we can't fail. From a
2956 * kmem/slab perspective, the cache has already been selected,
2957 * by mem_cgroup_kmem_get_cache(), so it is too late to change
2960 * This condition will only trigger if the task entered
2961 * memcg_charge_kmem in a sane state, but was OOM-killed during
2962 * mem_cgroup_try_charge() above. Tasks that were already
2963 * dying when the allocation triggers should have been already
2964 * directed to the root cgroup in memcontrol.h
2966 res_counter_charge_nofail(&memcg
->res
, size
, &fail_res
);
2967 if (do_swap_account
)
2968 res_counter_charge_nofail(&memcg
->memsw
, size
,
2972 res_counter_uncharge(&memcg
->kmem
, size
);
2977 static void memcg_uncharge_kmem(struct mem_cgroup
*memcg
, u64 size
)
2979 res_counter_uncharge(&memcg
->res
, size
);
2980 if (do_swap_account
)
2981 res_counter_uncharge(&memcg
->memsw
, size
);
2984 if (res_counter_uncharge(&memcg
->kmem
, size
))
2988 * Releases a reference taken in kmem_cgroup_css_offline in case
2989 * this last uncharge is racing with the offlining code or it is
2990 * outliving the memcg existence.
2992 * The memory barrier imposed by test&clear is paired with the
2993 * explicit one in memcg_kmem_mark_dead().
2995 if (memcg_kmem_test_and_clear_dead(memcg
))
2996 css_put(&memcg
->css
);
3000 * helper for acessing a memcg's index. It will be used as an index in the
3001 * child cache array in kmem_cache, and also to derive its name. This function
3002 * will return -1 when this is not a kmem-limited memcg.
3004 int memcg_cache_id(struct mem_cgroup
*memcg
)
3006 return memcg
? memcg
->kmemcg_id
: -1;
3009 static size_t memcg_caches_array_size(int num_groups
)
3012 if (num_groups
<= 0)
3015 size
= 2 * num_groups
;
3016 if (size
< MEMCG_CACHES_MIN_SIZE
)
3017 size
= MEMCG_CACHES_MIN_SIZE
;
3018 else if (size
> MEMCG_CACHES_MAX_SIZE
)
3019 size
= MEMCG_CACHES_MAX_SIZE
;
3025 * We should update the current array size iff all caches updates succeed. This
3026 * can only be done from the slab side. The slab mutex needs to be held when
3029 void memcg_update_array_size(int num
)
3031 if (num
> memcg_limited_groups_array_size
)
3032 memcg_limited_groups_array_size
= memcg_caches_array_size(num
);
3035 int memcg_update_cache_size(struct kmem_cache
*s
, int num_groups
)
3037 struct memcg_cache_params
*cur_params
= s
->memcg_params
;
3039 VM_BUG_ON(!is_root_cache(s
));
3041 if (num_groups
> memcg_limited_groups_array_size
) {
3043 struct memcg_cache_params
*new_params
;
3044 ssize_t size
= memcg_caches_array_size(num_groups
);
3046 size
*= sizeof(void *);
3047 size
+= offsetof(struct memcg_cache_params
, memcg_caches
);
3049 new_params
= kzalloc(size
, GFP_KERNEL
);
3053 new_params
->is_root_cache
= true;
3056 * There is the chance it will be bigger than
3057 * memcg_limited_groups_array_size, if we failed an allocation
3058 * in a cache, in which case all caches updated before it, will
3059 * have a bigger array.
3061 * But if that is the case, the data after
3062 * memcg_limited_groups_array_size is certainly unused
3064 for (i
= 0; i
< memcg_limited_groups_array_size
; i
++) {
3065 if (!cur_params
->memcg_caches
[i
])
3067 new_params
->memcg_caches
[i
] =
3068 cur_params
->memcg_caches
[i
];
3072 * Ideally, we would wait until all caches succeed, and only
3073 * then free the old one. But this is not worth the extra
3074 * pointer per-cache we'd have to have for this.
3076 * It is not a big deal if some caches are left with a size
3077 * bigger than the others. And all updates will reset this
3080 rcu_assign_pointer(s
->memcg_params
, new_params
);
3082 kfree_rcu(cur_params
, rcu_head
);
3087 int memcg_alloc_cache_params(struct mem_cgroup
*memcg
, struct kmem_cache
*s
,
3088 struct kmem_cache
*root_cache
)
3092 if (!memcg_kmem_enabled())
3096 size
= offsetof(struct memcg_cache_params
, memcg_caches
);
3097 size
+= memcg_limited_groups_array_size
* sizeof(void *);
3099 size
= sizeof(struct memcg_cache_params
);
3101 s
->memcg_params
= kzalloc(size
, GFP_KERNEL
);
3102 if (!s
->memcg_params
)
3106 s
->memcg_params
->memcg
= memcg
;
3107 s
->memcg_params
->root_cache
= root_cache
;
3108 css_get(&memcg
->css
);
3110 s
->memcg_params
->is_root_cache
= true;
3115 void memcg_free_cache_params(struct kmem_cache
*s
)
3117 if (!s
->memcg_params
)
3119 if (!s
->memcg_params
->is_root_cache
)
3120 css_put(&s
->memcg_params
->memcg
->css
);
3121 kfree(s
->memcg_params
);
3124 static void memcg_register_cache(struct mem_cgroup
*memcg
,
3125 struct kmem_cache
*root_cache
)
3127 static char memcg_name_buf
[NAME_MAX
+ 1]; /* protected by
3129 struct kmem_cache
*cachep
;
3132 lockdep_assert_held(&memcg_slab_mutex
);
3134 id
= memcg_cache_id(memcg
);
3137 * Since per-memcg caches are created asynchronously on first
3138 * allocation (see memcg_kmem_get_cache()), several threads can try to
3139 * create the same cache, but only one of them may succeed.
3141 if (cache_from_memcg_idx(root_cache
, id
))
3144 cgroup_name(memcg
->css
.cgroup
, memcg_name_buf
, NAME_MAX
+ 1);
3145 cachep
= memcg_create_kmem_cache(memcg
, root_cache
, memcg_name_buf
);
3147 * If we could not create a memcg cache, do not complain, because
3148 * that's not critical at all as we can always proceed with the root
3154 list_add(&cachep
->memcg_params
->list
, &memcg
->memcg_slab_caches
);
3157 * Since readers won't lock (see cache_from_memcg_idx()), we need a
3158 * barrier here to ensure nobody will see the kmem_cache partially
3163 BUG_ON(root_cache
->memcg_params
->memcg_caches
[id
]);
3164 root_cache
->memcg_params
->memcg_caches
[id
] = cachep
;
3167 static void memcg_unregister_cache(struct kmem_cache
*cachep
)
3169 struct kmem_cache
*root_cache
;
3170 struct mem_cgroup
*memcg
;
3173 lockdep_assert_held(&memcg_slab_mutex
);
3175 BUG_ON(is_root_cache(cachep
));
3177 root_cache
= cachep
->memcg_params
->root_cache
;
3178 memcg
= cachep
->memcg_params
->memcg
;
3179 id
= memcg_cache_id(memcg
);
3181 BUG_ON(root_cache
->memcg_params
->memcg_caches
[id
] != cachep
);
3182 root_cache
->memcg_params
->memcg_caches
[id
] = NULL
;
3184 list_del(&cachep
->memcg_params
->list
);
3186 kmem_cache_destroy(cachep
);
3190 * During the creation a new cache, we need to disable our accounting mechanism
3191 * altogether. This is true even if we are not creating, but rather just
3192 * enqueing new caches to be created.
3194 * This is because that process will trigger allocations; some visible, like
3195 * explicit kmallocs to auxiliary data structures, name strings and internal
3196 * cache structures; some well concealed, like INIT_WORK() that can allocate
3197 * objects during debug.
3199 * If any allocation happens during memcg_kmem_get_cache, we will recurse back
3200 * to it. This may not be a bounded recursion: since the first cache creation
3201 * failed to complete (waiting on the allocation), we'll just try to create the
3202 * cache again, failing at the same point.
3204 * memcg_kmem_get_cache is prepared to abort after seeing a positive count of
3205 * memcg_kmem_skip_account. So we enclose anything that might allocate memory
3206 * inside the following two functions.
3208 static inline void memcg_stop_kmem_account(void)
3210 VM_BUG_ON(!current
->mm
);
3211 current
->memcg_kmem_skip_account
++;
3214 static inline void memcg_resume_kmem_account(void)
3216 VM_BUG_ON(!current
->mm
);
3217 current
->memcg_kmem_skip_account
--;
3220 int __memcg_cleanup_cache_params(struct kmem_cache
*s
)
3222 struct kmem_cache
*c
;
3225 mutex_lock(&memcg_slab_mutex
);
3226 for_each_memcg_cache_index(i
) {
3227 c
= cache_from_memcg_idx(s
, i
);
3231 memcg_unregister_cache(c
);
3233 if (cache_from_memcg_idx(s
, i
))
3236 mutex_unlock(&memcg_slab_mutex
);
3240 static void memcg_unregister_all_caches(struct mem_cgroup
*memcg
)
3242 struct kmem_cache
*cachep
;
3243 struct memcg_cache_params
*params
, *tmp
;
3245 if (!memcg_kmem_is_active(memcg
))
3248 mutex_lock(&memcg_slab_mutex
);
3249 list_for_each_entry_safe(params
, tmp
, &memcg
->memcg_slab_caches
, list
) {
3250 cachep
= memcg_params_to_cache(params
);
3251 kmem_cache_shrink(cachep
);
3252 if (atomic_read(&cachep
->memcg_params
->nr_pages
) == 0)
3253 memcg_unregister_cache(cachep
);
3255 mutex_unlock(&memcg_slab_mutex
);
3258 struct memcg_register_cache_work
{
3259 struct mem_cgroup
*memcg
;
3260 struct kmem_cache
*cachep
;
3261 struct work_struct work
;
3264 static void memcg_register_cache_func(struct work_struct
*w
)
3266 struct memcg_register_cache_work
*cw
=
3267 container_of(w
, struct memcg_register_cache_work
, work
);
3268 struct mem_cgroup
*memcg
= cw
->memcg
;
3269 struct kmem_cache
*cachep
= cw
->cachep
;
3271 mutex_lock(&memcg_slab_mutex
);
3272 memcg_register_cache(memcg
, cachep
);
3273 mutex_unlock(&memcg_slab_mutex
);
3275 css_put(&memcg
->css
);
3280 * Enqueue the creation of a per-memcg kmem_cache.
3282 static void __memcg_schedule_register_cache(struct mem_cgroup
*memcg
,
3283 struct kmem_cache
*cachep
)
3285 struct memcg_register_cache_work
*cw
;
3287 cw
= kmalloc(sizeof(*cw
), GFP_NOWAIT
);
3289 css_put(&memcg
->css
);
3294 cw
->cachep
= cachep
;
3296 INIT_WORK(&cw
->work
, memcg_register_cache_func
);
3297 schedule_work(&cw
->work
);
3300 static void memcg_schedule_register_cache(struct mem_cgroup
*memcg
,
3301 struct kmem_cache
*cachep
)
3304 * We need to stop accounting when we kmalloc, because if the
3305 * corresponding kmalloc cache is not yet created, the first allocation
3306 * in __memcg_schedule_register_cache will recurse.
3308 * However, it is better to enclose the whole function. Depending on
3309 * the debugging options enabled, INIT_WORK(), for instance, can
3310 * trigger an allocation. This too, will make us recurse. Because at
3311 * this point we can't allow ourselves back into memcg_kmem_get_cache,
3312 * the safest choice is to do it like this, wrapping the whole function.
3314 memcg_stop_kmem_account();
3315 __memcg_schedule_register_cache(memcg
, cachep
);
3316 memcg_resume_kmem_account();
3319 int __memcg_charge_slab(struct kmem_cache
*cachep
, gfp_t gfp
, int order
)
3323 res
= memcg_charge_kmem(cachep
->memcg_params
->memcg
, gfp
,
3324 PAGE_SIZE
<< order
);
3326 atomic_add(1 << order
, &cachep
->memcg_params
->nr_pages
);
3330 void __memcg_uncharge_slab(struct kmem_cache
*cachep
, int order
)
3332 memcg_uncharge_kmem(cachep
->memcg_params
->memcg
, PAGE_SIZE
<< order
);
3333 atomic_sub(1 << order
, &cachep
->memcg_params
->nr_pages
);
3337 * Return the kmem_cache we're supposed to use for a slab allocation.
3338 * We try to use the current memcg's version of the cache.
3340 * If the cache does not exist yet, if we are the first user of it,
3341 * we either create it immediately, if possible, or create it asynchronously
3343 * In the latter case, we will let the current allocation go through with
3344 * the original cache.
3346 * Can't be called in interrupt context or from kernel threads.
3347 * This function needs to be called with rcu_read_lock() held.
3349 struct kmem_cache
*__memcg_kmem_get_cache(struct kmem_cache
*cachep
,
3352 struct mem_cgroup
*memcg
;
3353 struct kmem_cache
*memcg_cachep
;
3355 VM_BUG_ON(!cachep
->memcg_params
);
3356 VM_BUG_ON(!cachep
->memcg_params
->is_root_cache
);
3358 if (!current
->mm
|| current
->memcg_kmem_skip_account
)
3362 memcg
= mem_cgroup_from_task(rcu_dereference(current
->mm
->owner
));
3364 if (!memcg_can_account_kmem(memcg
))
3367 memcg_cachep
= cache_from_memcg_idx(cachep
, memcg_cache_id(memcg
));
3368 if (likely(memcg_cachep
)) {
3369 cachep
= memcg_cachep
;
3373 /* The corresponding put will be done in the workqueue. */
3374 if (!css_tryget(&memcg
->css
))
3379 * If we are in a safe context (can wait, and not in interrupt
3380 * context), we could be be predictable and return right away.
3381 * This would guarantee that the allocation being performed
3382 * already belongs in the new cache.
3384 * However, there are some clashes that can arrive from locking.
3385 * For instance, because we acquire the slab_mutex while doing
3386 * memcg_create_kmem_cache, this means no further allocation
3387 * could happen with the slab_mutex held. So it's better to
3390 memcg_schedule_register_cache(memcg
, cachep
);
3398 * We need to verify if the allocation against current->mm->owner's memcg is
3399 * possible for the given order. But the page is not allocated yet, so we'll
3400 * need a further commit step to do the final arrangements.
3402 * It is possible for the task to switch cgroups in this mean time, so at
3403 * commit time, we can't rely on task conversion any longer. We'll then use
3404 * the handle argument to return to the caller which cgroup we should commit
3405 * against. We could also return the memcg directly and avoid the pointer
3406 * passing, but a boolean return value gives better semantics considering
3407 * the compiled-out case as well.
3409 * Returning true means the allocation is possible.
3412 __memcg_kmem_newpage_charge(gfp_t gfp
, struct mem_cgroup
**_memcg
, int order
)
3414 struct mem_cgroup
*memcg
;
3420 * Disabling accounting is only relevant for some specific memcg
3421 * internal allocations. Therefore we would initially not have such
3422 * check here, since direct calls to the page allocator that are
3423 * accounted to kmemcg (alloc_kmem_pages and friends) only happen
3424 * outside memcg core. We are mostly concerned with cache allocations,
3425 * and by having this test at memcg_kmem_get_cache, we are already able
3426 * to relay the allocation to the root cache and bypass the memcg cache
3429 * There is one exception, though: the SLUB allocator does not create
3430 * large order caches, but rather service large kmallocs directly from
3431 * the page allocator. Therefore, the following sequence when backed by
3432 * the SLUB allocator:
3434 * memcg_stop_kmem_account();
3435 * kmalloc(<large_number>)
3436 * memcg_resume_kmem_account();
3438 * would effectively ignore the fact that we should skip accounting,
3439 * since it will drive us directly to this function without passing
3440 * through the cache selector memcg_kmem_get_cache. Such large
3441 * allocations are extremely rare but can happen, for instance, for the
3442 * cache arrays. We bring this test here.
3444 if (!current
->mm
|| current
->memcg_kmem_skip_account
)
3447 memcg
= get_mem_cgroup_from_mm(current
->mm
);
3449 if (!memcg_can_account_kmem(memcg
)) {
3450 css_put(&memcg
->css
);
3454 ret
= memcg_charge_kmem(memcg
, gfp
, PAGE_SIZE
<< order
);
3458 css_put(&memcg
->css
);
3462 void __memcg_kmem_commit_charge(struct page
*page
, struct mem_cgroup
*memcg
,
3465 struct page_cgroup
*pc
;
3467 VM_BUG_ON(mem_cgroup_is_root(memcg
));
3469 /* The page allocation failed. Revert */
3471 memcg_uncharge_kmem(memcg
, PAGE_SIZE
<< order
);
3475 pc
= lookup_page_cgroup(page
);
3476 lock_page_cgroup(pc
);
3477 pc
->mem_cgroup
= memcg
;
3478 SetPageCgroupUsed(pc
);
3479 unlock_page_cgroup(pc
);
3482 void __memcg_kmem_uncharge_pages(struct page
*page
, int order
)
3484 struct mem_cgroup
*memcg
= NULL
;
3485 struct page_cgroup
*pc
;
3488 pc
= lookup_page_cgroup(page
);
3490 * Fast unlocked return. Theoretically might have changed, have to
3491 * check again after locking.
3493 if (!PageCgroupUsed(pc
))
3496 lock_page_cgroup(pc
);
3497 if (PageCgroupUsed(pc
)) {
3498 memcg
= pc
->mem_cgroup
;
3499 ClearPageCgroupUsed(pc
);
3501 unlock_page_cgroup(pc
);
3504 * We trust that only if there is a memcg associated with the page, it
3505 * is a valid allocation
3510 VM_BUG_ON_PAGE(mem_cgroup_is_root(memcg
), page
);
3511 memcg_uncharge_kmem(memcg
, PAGE_SIZE
<< order
);
3514 static inline void memcg_unregister_all_caches(struct mem_cgroup
*memcg
)
3517 #endif /* CONFIG_MEMCG_KMEM */
3519 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
3521 #define PCGF_NOCOPY_AT_SPLIT (1 << PCG_LOCK | 1 << PCG_MIGRATION)
3523 * Because tail pages are not marked as "used", set it. We're under
3524 * zone->lru_lock, 'splitting on pmd' and compound_lock.
3525 * charge/uncharge will be never happen and move_account() is done under
3526 * compound_lock(), so we don't have to take care of races.
3528 void mem_cgroup_split_huge_fixup(struct page
*head
)
3530 struct page_cgroup
*head_pc
= lookup_page_cgroup(head
);
3531 struct page_cgroup
*pc
;
3532 struct mem_cgroup
*memcg
;
3535 if (mem_cgroup_disabled())
3538 memcg
= head_pc
->mem_cgroup
;
3539 for (i
= 1; i
< HPAGE_PMD_NR
; i
++) {
3541 pc
->mem_cgroup
= memcg
;
3542 smp_wmb();/* see __commit_charge() */
3543 pc
->flags
= head_pc
->flags
& ~PCGF_NOCOPY_AT_SPLIT
;
3545 __this_cpu_sub(memcg
->stat
->count
[MEM_CGROUP_STAT_RSS_HUGE
],
3548 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
3551 * mem_cgroup_move_account - move account of the page
3553 * @nr_pages: number of regular pages (>1 for huge pages)
3554 * @pc: page_cgroup of the page.
3555 * @from: mem_cgroup which the page is moved from.
3556 * @to: mem_cgroup which the page is moved to. @from != @to.
3558 * The caller must confirm following.
3559 * - page is not on LRU (isolate_page() is useful.)
3560 * - compound_lock is held when nr_pages > 1
3562 * This function doesn't do "charge" to new cgroup and doesn't do "uncharge"
3565 static int mem_cgroup_move_account(struct page
*page
,
3566 unsigned int nr_pages
,
3567 struct page_cgroup
*pc
,
3568 struct mem_cgroup
*from
,
3569 struct mem_cgroup
*to
)
3571 unsigned long flags
;
3573 bool anon
= PageAnon(page
);
3575 VM_BUG_ON(from
== to
);
3576 VM_BUG_ON_PAGE(PageLRU(page
), page
);
3578 * The page is isolated from LRU. So, collapse function
3579 * will not handle this page. But page splitting can happen.
3580 * Do this check under compound_page_lock(). The caller should
3584 if (nr_pages
> 1 && !PageTransHuge(page
))
3587 lock_page_cgroup(pc
);
3590 if (!PageCgroupUsed(pc
) || pc
->mem_cgroup
!= from
)
3593 move_lock_mem_cgroup(from
, &flags
);
3595 if (!anon
&& page_mapped(page
)) {
3596 __this_cpu_sub(from
->stat
->count
[MEM_CGROUP_STAT_FILE_MAPPED
],
3598 __this_cpu_add(to
->stat
->count
[MEM_CGROUP_STAT_FILE_MAPPED
],
3602 if (PageWriteback(page
)) {
3603 __this_cpu_sub(from
->stat
->count
[MEM_CGROUP_STAT_WRITEBACK
],
3605 __this_cpu_add(to
->stat
->count
[MEM_CGROUP_STAT_WRITEBACK
],
3609 mem_cgroup_charge_statistics(from
, page
, anon
, -nr_pages
);
3611 /* caller should have done css_get */
3612 pc
->mem_cgroup
= to
;
3613 mem_cgroup_charge_statistics(to
, page
, anon
, nr_pages
);
3614 move_unlock_mem_cgroup(from
, &flags
);
3617 unlock_page_cgroup(pc
);
3621 memcg_check_events(to
, page
);
3622 memcg_check_events(from
, page
);
3628 * mem_cgroup_move_parent - moves page to the parent group
3629 * @page: the page to move
3630 * @pc: page_cgroup of the page
3631 * @child: page's cgroup
3633 * move charges to its parent or the root cgroup if the group has no
3634 * parent (aka use_hierarchy==0).
3635 * Although this might fail (get_page_unless_zero, isolate_lru_page or
3636 * mem_cgroup_move_account fails) the failure is always temporary and
3637 * it signals a race with a page removal/uncharge or migration. In the
3638 * first case the page is on the way out and it will vanish from the LRU
3639 * on the next attempt and the call should be retried later.
3640 * Isolation from the LRU fails only if page has been isolated from
3641 * the LRU since we looked at it and that usually means either global
3642 * reclaim or migration going on. The page will either get back to the
3644 * Finaly mem_cgroup_move_account fails only if the page got uncharged
3645 * (!PageCgroupUsed) or moved to a different group. The page will
3646 * disappear in the next attempt.
3648 static int mem_cgroup_move_parent(struct page
*page
,
3649 struct page_cgroup
*pc
,
3650 struct mem_cgroup
*child
)
3652 struct mem_cgroup
*parent
;
3653 unsigned int nr_pages
;
3654 unsigned long uninitialized_var(flags
);
3657 VM_BUG_ON(mem_cgroup_is_root(child
));
3660 if (!get_page_unless_zero(page
))
3662 if (isolate_lru_page(page
))
3665 nr_pages
= hpage_nr_pages(page
);
3667 parent
= parent_mem_cgroup(child
);
3669 * If no parent, move charges to root cgroup.
3672 parent
= root_mem_cgroup
;
3675 VM_BUG_ON_PAGE(!PageTransHuge(page
), page
);
3676 flags
= compound_lock_irqsave(page
);
3679 ret
= mem_cgroup_move_account(page
, nr_pages
,
3682 __mem_cgroup_cancel_local_charge(child
, nr_pages
);
3685 compound_unlock_irqrestore(page
, flags
);
3686 putback_lru_page(page
);
3693 int mem_cgroup_charge_anon(struct page
*page
,
3694 struct mm_struct
*mm
, gfp_t gfp_mask
)
3696 unsigned int nr_pages
= 1;
3697 struct mem_cgroup
*memcg
;
3700 if (mem_cgroup_disabled())
3703 VM_BUG_ON_PAGE(page_mapped(page
), page
);
3704 VM_BUG_ON_PAGE(page
->mapping
&& !PageAnon(page
), page
);
3707 if (PageTransHuge(page
)) {
3708 nr_pages
<<= compound_order(page
);
3709 VM_BUG_ON_PAGE(!PageTransHuge(page
), page
);
3711 * Never OOM-kill a process for a huge page. The
3712 * fault handler will fall back to regular pages.
3717 memcg
= mem_cgroup_try_charge_mm(mm
, gfp_mask
, nr_pages
, oom
);
3720 __mem_cgroup_commit_charge(memcg
, page
, nr_pages
,
3721 MEM_CGROUP_CHARGE_TYPE_ANON
, false);
3726 * While swap-in, try_charge -> commit or cancel, the page is locked.
3727 * And when try_charge() successfully returns, one refcnt to memcg without
3728 * struct page_cgroup is acquired. This refcnt will be consumed by
3729 * "commit()" or removed by "cancel()"
3731 static int __mem_cgroup_try_charge_swapin(struct mm_struct
*mm
,
3734 struct mem_cgroup
**memcgp
)
3736 struct mem_cgroup
*memcg
= NULL
;
3737 struct page_cgroup
*pc
;
3740 pc
= lookup_page_cgroup(page
);
3742 * Every swap fault against a single page tries to charge the
3743 * page, bail as early as possible. shmem_unuse() encounters
3744 * already charged pages, too. The USED bit is protected by
3745 * the page lock, which serializes swap cache removal, which
3746 * in turn serializes uncharging.
3748 if (PageCgroupUsed(pc
))
3750 if (do_swap_account
)
3751 memcg
= try_get_mem_cgroup_from_page(page
);
3753 memcg
= get_mem_cgroup_from_mm(mm
);
3754 ret
= mem_cgroup_try_charge(memcg
, mask
, 1, true);
3755 css_put(&memcg
->css
);
3757 memcg
= root_mem_cgroup
;
3765 int mem_cgroup_try_charge_swapin(struct mm_struct
*mm
, struct page
*page
,
3766 gfp_t gfp_mask
, struct mem_cgroup
**memcgp
)
3768 if (mem_cgroup_disabled()) {
3773 * A racing thread's fault, or swapoff, may have already
3774 * updated the pte, and even removed page from swap cache: in
3775 * those cases unuse_pte()'s pte_same() test will fail; but
3776 * there's also a KSM case which does need to charge the page.
3778 if (!PageSwapCache(page
)) {
3779 struct mem_cgroup
*memcg
;
3781 memcg
= mem_cgroup_try_charge_mm(mm
, gfp_mask
, 1, true);
3787 return __mem_cgroup_try_charge_swapin(mm
, page
, gfp_mask
, memcgp
);
3790 void mem_cgroup_cancel_charge_swapin(struct mem_cgroup
*memcg
)
3792 if (mem_cgroup_disabled())
3796 __mem_cgroup_cancel_charge(memcg
, 1);
3800 __mem_cgroup_commit_charge_swapin(struct page
*page
, struct mem_cgroup
*memcg
,
3801 enum charge_type ctype
)
3803 if (mem_cgroup_disabled())
3808 __mem_cgroup_commit_charge(memcg
, page
, 1, ctype
, true);
3810 * Now swap is on-memory. This means this page may be
3811 * counted both as mem and swap....double count.
3812 * Fix it by uncharging from memsw. Basically, this SwapCache is stable
3813 * under lock_page(). But in do_swap_page()::memory.c, reuse_swap_page()
3814 * may call delete_from_swap_cache() before reach here.
3816 if (do_swap_account
&& PageSwapCache(page
)) {
3817 swp_entry_t ent
= {.val
= page_private(page
)};
3818 mem_cgroup_uncharge_swap(ent
);
3822 void mem_cgroup_commit_charge_swapin(struct page
*page
,
3823 struct mem_cgroup
*memcg
)
3825 __mem_cgroup_commit_charge_swapin(page
, memcg
,
3826 MEM_CGROUP_CHARGE_TYPE_ANON
);
3829 int mem_cgroup_charge_file(struct page
*page
, struct mm_struct
*mm
,
3832 enum charge_type type
= MEM_CGROUP_CHARGE_TYPE_CACHE
;
3833 struct mem_cgroup
*memcg
;
3836 if (mem_cgroup_disabled())
3838 if (PageCompound(page
))
3841 if (PageSwapCache(page
)) { /* shmem */
3842 ret
= __mem_cgroup_try_charge_swapin(mm
, page
,
3846 __mem_cgroup_commit_charge_swapin(page
, memcg
, type
);
3850 memcg
= mem_cgroup_try_charge_mm(mm
, gfp_mask
, 1, true);
3853 __mem_cgroup_commit_charge(memcg
, page
, 1, type
, false);
3857 static void mem_cgroup_do_uncharge(struct mem_cgroup
*memcg
,
3858 unsigned int nr_pages
,
3859 const enum charge_type ctype
)
3861 struct memcg_batch_info
*batch
= NULL
;
3862 bool uncharge_memsw
= true;
3864 /* If swapout, usage of swap doesn't decrease */
3865 if (!do_swap_account
|| ctype
== MEM_CGROUP_CHARGE_TYPE_SWAPOUT
)
3866 uncharge_memsw
= false;
3868 batch
= ¤t
->memcg_batch
;
3870 * In usual, we do css_get() when we remember memcg pointer.
3871 * But in this case, we keep res->usage until end of a series of
3872 * uncharges. Then, it's ok to ignore memcg's refcnt.
3875 batch
->memcg
= memcg
;
3877 * do_batch > 0 when unmapping pages or inode invalidate/truncate.
3878 * In those cases, all pages freed continuously can be expected to be in
3879 * the same cgroup and we have chance to coalesce uncharges.
3880 * But we do uncharge one by one if this is killed by OOM(TIF_MEMDIE)
3881 * because we want to do uncharge as soon as possible.
3884 if (!batch
->do_batch
|| test_thread_flag(TIF_MEMDIE
))
3885 goto direct_uncharge
;
3888 goto direct_uncharge
;
3891 * In typical case, batch->memcg == mem. This means we can
3892 * merge a series of uncharges to an uncharge of res_counter.
3893 * If not, we uncharge res_counter ony by one.
3895 if (batch
->memcg
!= memcg
)
3896 goto direct_uncharge
;
3897 /* remember freed charge and uncharge it later */
3900 batch
->memsw_nr_pages
++;
3903 res_counter_uncharge(&memcg
->res
, nr_pages
* PAGE_SIZE
);
3905 res_counter_uncharge(&memcg
->memsw
, nr_pages
* PAGE_SIZE
);
3906 if (unlikely(batch
->memcg
!= memcg
))
3907 memcg_oom_recover(memcg
);
3911 * uncharge if !page_mapped(page)
3913 static struct mem_cgroup
*
3914 __mem_cgroup_uncharge_common(struct page
*page
, enum charge_type ctype
,
3917 struct mem_cgroup
*memcg
= NULL
;
3918 unsigned int nr_pages
= 1;
3919 struct page_cgroup
*pc
;
3922 if (mem_cgroup_disabled())
3925 if (PageTransHuge(page
)) {
3926 nr_pages
<<= compound_order(page
);
3927 VM_BUG_ON_PAGE(!PageTransHuge(page
), page
);
3930 * Check if our page_cgroup is valid
3932 pc
= lookup_page_cgroup(page
);
3933 if (unlikely(!PageCgroupUsed(pc
)))
3936 lock_page_cgroup(pc
);
3938 memcg
= pc
->mem_cgroup
;
3940 if (!PageCgroupUsed(pc
))
3943 anon
= PageAnon(page
);
3946 case MEM_CGROUP_CHARGE_TYPE_ANON
:
3948 * Generally PageAnon tells if it's the anon statistics to be
3949 * updated; but sometimes e.g. mem_cgroup_uncharge_page() is
3950 * used before page reached the stage of being marked PageAnon.
3954 case MEM_CGROUP_CHARGE_TYPE_DROP
:
3955 /* See mem_cgroup_prepare_migration() */
3956 if (page_mapped(page
))
3959 * Pages under migration may not be uncharged. But
3960 * end_migration() /must/ be the one uncharging the
3961 * unused post-migration page and so it has to call
3962 * here with the migration bit still set. See the
3963 * res_counter handling below.
3965 if (!end_migration
&& PageCgroupMigration(pc
))
3968 case MEM_CGROUP_CHARGE_TYPE_SWAPOUT
:
3969 if (!PageAnon(page
)) { /* Shared memory */
3970 if (page
->mapping
&& !page_is_file_cache(page
))
3972 } else if (page_mapped(page
)) /* Anon */
3979 mem_cgroup_charge_statistics(memcg
, page
, anon
, -nr_pages
);
3981 ClearPageCgroupUsed(pc
);
3983 * pc->mem_cgroup is not cleared here. It will be accessed when it's
3984 * freed from LRU. This is safe because uncharged page is expected not
3985 * to be reused (freed soon). Exception is SwapCache, it's handled by
3986 * special functions.
3989 unlock_page_cgroup(pc
);
3991 * even after unlock, we have memcg->res.usage here and this memcg
3992 * will never be freed, so it's safe to call css_get().
3994 memcg_check_events(memcg
, page
);
3995 if (do_swap_account
&& ctype
== MEM_CGROUP_CHARGE_TYPE_SWAPOUT
) {
3996 mem_cgroup_swap_statistics(memcg
, true);
3997 css_get(&memcg
->css
);
4000 * Migration does not charge the res_counter for the
4001 * replacement page, so leave it alone when phasing out the
4002 * page that is unused after the migration.
4004 if (!end_migration
&& !mem_cgroup_is_root(memcg
))
4005 mem_cgroup_do_uncharge(memcg
, nr_pages
, ctype
);
4010 unlock_page_cgroup(pc
);
4014 void mem_cgroup_uncharge_page(struct page
*page
)
4017 if (page_mapped(page
))
4019 VM_BUG_ON_PAGE(page
->mapping
&& !PageAnon(page
), page
);
4021 * If the page is in swap cache, uncharge should be deferred
4022 * to the swap path, which also properly accounts swap usage
4023 * and handles memcg lifetime.
4025 * Note that this check is not stable and reclaim may add the
4026 * page to swap cache at any time after this. However, if the
4027 * page is not in swap cache by the time page->mapcount hits
4028 * 0, there won't be any page table references to the swap
4029 * slot, and reclaim will free it and not actually write the
4032 if (PageSwapCache(page
))
4034 __mem_cgroup_uncharge_common(page
, MEM_CGROUP_CHARGE_TYPE_ANON
, false);
4037 void mem_cgroup_uncharge_cache_page(struct page
*page
)
4039 VM_BUG_ON_PAGE(page_mapped(page
), page
);
4040 VM_BUG_ON_PAGE(page
->mapping
, page
);
4041 __mem_cgroup_uncharge_common(page
, MEM_CGROUP_CHARGE_TYPE_CACHE
, false);
4045 * Batch_start/batch_end is called in unmap_page_range/invlidate/trucate.
4046 * In that cases, pages are freed continuously and we can expect pages
4047 * are in the same memcg. All these calls itself limits the number of
4048 * pages freed at once, then uncharge_start/end() is called properly.
4049 * This may be called prural(2) times in a context,
4052 void mem_cgroup_uncharge_start(void)
4054 current
->memcg_batch
.do_batch
++;
4055 /* We can do nest. */
4056 if (current
->memcg_batch
.do_batch
== 1) {
4057 current
->memcg_batch
.memcg
= NULL
;
4058 current
->memcg_batch
.nr_pages
= 0;
4059 current
->memcg_batch
.memsw_nr_pages
= 0;
4063 void mem_cgroup_uncharge_end(void)
4065 struct memcg_batch_info
*batch
= ¤t
->memcg_batch
;
4067 if (!batch
->do_batch
)
4071 if (batch
->do_batch
) /* If stacked, do nothing. */
4077 * This "batch->memcg" is valid without any css_get/put etc...
4078 * bacause we hide charges behind us.
4080 if (batch
->nr_pages
)
4081 res_counter_uncharge(&batch
->memcg
->res
,
4082 batch
->nr_pages
* PAGE_SIZE
);
4083 if (batch
->memsw_nr_pages
)
4084 res_counter_uncharge(&batch
->memcg
->memsw
,
4085 batch
->memsw_nr_pages
* PAGE_SIZE
);
4086 memcg_oom_recover(batch
->memcg
);
4087 /* forget this pointer (for sanity check) */
4088 batch
->memcg
= NULL
;
4093 * called after __delete_from_swap_cache() and drop "page" account.
4094 * memcg information is recorded to swap_cgroup of "ent"
4097 mem_cgroup_uncharge_swapcache(struct page
*page
, swp_entry_t ent
, bool swapout
)
4099 struct mem_cgroup
*memcg
;
4100 int ctype
= MEM_CGROUP_CHARGE_TYPE_SWAPOUT
;
4102 if (!swapout
) /* this was a swap cache but the swap is unused ! */
4103 ctype
= MEM_CGROUP_CHARGE_TYPE_DROP
;
4105 memcg
= __mem_cgroup_uncharge_common(page
, ctype
, false);
4108 * record memcg information, if swapout && memcg != NULL,
4109 * css_get() was called in uncharge().
4111 if (do_swap_account
&& swapout
&& memcg
)
4112 swap_cgroup_record(ent
, mem_cgroup_id(memcg
));
4116 #ifdef CONFIG_MEMCG_SWAP
4118 * called from swap_entry_free(). remove record in swap_cgroup and
4119 * uncharge "memsw" account.
4121 void mem_cgroup_uncharge_swap(swp_entry_t ent
)
4123 struct mem_cgroup
*memcg
;
4126 if (!do_swap_account
)
4129 id
= swap_cgroup_record(ent
, 0);
4131 memcg
= mem_cgroup_lookup(id
);
4134 * We uncharge this because swap is freed.
4135 * This memcg can be obsolete one. We avoid calling css_tryget
4137 if (!mem_cgroup_is_root(memcg
))
4138 res_counter_uncharge(&memcg
->memsw
, PAGE_SIZE
);
4139 mem_cgroup_swap_statistics(memcg
, false);
4140 css_put(&memcg
->css
);
4146 * mem_cgroup_move_swap_account - move swap charge and swap_cgroup's record.
4147 * @entry: swap entry to be moved
4148 * @from: mem_cgroup which the entry is moved from
4149 * @to: mem_cgroup which the entry is moved to
4151 * It succeeds only when the swap_cgroup's record for this entry is the same
4152 * as the mem_cgroup's id of @from.
4154 * Returns 0 on success, -EINVAL on failure.
4156 * The caller must have charged to @to, IOW, called res_counter_charge() about
4157 * both res and memsw, and called css_get().
4159 static int mem_cgroup_move_swap_account(swp_entry_t entry
,
4160 struct mem_cgroup
*from
, struct mem_cgroup
*to
)
4162 unsigned short old_id
, new_id
;
4164 old_id
= mem_cgroup_id(from
);
4165 new_id
= mem_cgroup_id(to
);
4167 if (swap_cgroup_cmpxchg(entry
, old_id
, new_id
) == old_id
) {
4168 mem_cgroup_swap_statistics(from
, false);
4169 mem_cgroup_swap_statistics(to
, true);
4171 * This function is only called from task migration context now.
4172 * It postpones res_counter and refcount handling till the end
4173 * of task migration(mem_cgroup_clear_mc()) for performance
4174 * improvement. But we cannot postpone css_get(to) because if
4175 * the process that has been moved to @to does swap-in, the
4176 * refcount of @to might be decreased to 0.
4178 * We are in attach() phase, so the cgroup is guaranteed to be
4179 * alive, so we can just call css_get().
4187 static inline int mem_cgroup_move_swap_account(swp_entry_t entry
,
4188 struct mem_cgroup
*from
, struct mem_cgroup
*to
)
4195 * Before starting migration, account PAGE_SIZE to mem_cgroup that the old
4198 void mem_cgroup_prepare_migration(struct page
*page
, struct page
*newpage
,
4199 struct mem_cgroup
**memcgp
)
4201 struct mem_cgroup
*memcg
= NULL
;
4202 unsigned int nr_pages
= 1;
4203 struct page_cgroup
*pc
;
4204 enum charge_type ctype
;
4208 if (mem_cgroup_disabled())
4211 if (PageTransHuge(page
))
4212 nr_pages
<<= compound_order(page
);
4214 pc
= lookup_page_cgroup(page
);
4215 lock_page_cgroup(pc
);
4216 if (PageCgroupUsed(pc
)) {
4217 memcg
= pc
->mem_cgroup
;
4218 css_get(&memcg
->css
);
4220 * At migrating an anonymous page, its mapcount goes down
4221 * to 0 and uncharge() will be called. But, even if it's fully
4222 * unmapped, migration may fail and this page has to be
4223 * charged again. We set MIGRATION flag here and delay uncharge
4224 * until end_migration() is called
4226 * Corner Case Thinking
4228 * When the old page was mapped as Anon and it's unmap-and-freed
4229 * while migration was ongoing.
4230 * If unmap finds the old page, uncharge() of it will be delayed
4231 * until end_migration(). If unmap finds a new page, it's
4232 * uncharged when it make mapcount to be 1->0. If unmap code
4233 * finds swap_migration_entry, the new page will not be mapped
4234 * and end_migration() will find it(mapcount==0).
4237 * When the old page was mapped but migraion fails, the kernel
4238 * remaps it. A charge for it is kept by MIGRATION flag even
4239 * if mapcount goes down to 0. We can do remap successfully
4240 * without charging it again.
4243 * The "old" page is under lock_page() until the end of
4244 * migration, so, the old page itself will not be swapped-out.
4245 * If the new page is swapped out before end_migraton, our
4246 * hook to usual swap-out path will catch the event.
4249 SetPageCgroupMigration(pc
);
4251 unlock_page_cgroup(pc
);
4253 * If the page is not charged at this point,
4261 * We charge new page before it's used/mapped. So, even if unlock_page()
4262 * is called before end_migration, we can catch all events on this new
4263 * page. In the case new page is migrated but not remapped, new page's
4264 * mapcount will be finally 0 and we call uncharge in end_migration().
4267 ctype
= MEM_CGROUP_CHARGE_TYPE_ANON
;
4269 ctype
= MEM_CGROUP_CHARGE_TYPE_CACHE
;
4271 * The page is committed to the memcg, but it's not actually
4272 * charged to the res_counter since we plan on replacing the
4273 * old one and only one page is going to be left afterwards.
4275 __mem_cgroup_commit_charge(memcg
, newpage
, nr_pages
, ctype
, false);
4278 /* remove redundant charge if migration failed*/
4279 void mem_cgroup_end_migration(struct mem_cgroup
*memcg
,
4280 struct page
*oldpage
, struct page
*newpage
, bool migration_ok
)
4282 struct page
*used
, *unused
;
4283 struct page_cgroup
*pc
;
4289 if (!migration_ok
) {
4296 anon
= PageAnon(used
);
4297 __mem_cgroup_uncharge_common(unused
,
4298 anon
? MEM_CGROUP_CHARGE_TYPE_ANON
4299 : MEM_CGROUP_CHARGE_TYPE_CACHE
,
4301 css_put(&memcg
->css
);
4303 * We disallowed uncharge of pages under migration because mapcount
4304 * of the page goes down to zero, temporarly.
4305 * Clear the flag and check the page should be charged.
4307 pc
= lookup_page_cgroup(oldpage
);
4308 lock_page_cgroup(pc
);
4309 ClearPageCgroupMigration(pc
);
4310 unlock_page_cgroup(pc
);
4313 * If a page is a file cache, radix-tree replacement is very atomic
4314 * and we can skip this check. When it was an Anon page, its mapcount
4315 * goes down to 0. But because we added MIGRATION flage, it's not
4316 * uncharged yet. There are several case but page->mapcount check
4317 * and USED bit check in mem_cgroup_uncharge_page() will do enough
4318 * check. (see prepare_charge() also)
4321 mem_cgroup_uncharge_page(used
);
4325 * At replace page cache, newpage is not under any memcg but it's on
4326 * LRU. So, this function doesn't touch res_counter but handles LRU
4327 * in correct way. Both pages are locked so we cannot race with uncharge.
4329 void mem_cgroup_replace_page_cache(struct page
*oldpage
,
4330 struct page
*newpage
)
4332 struct mem_cgroup
*memcg
= NULL
;
4333 struct page_cgroup
*pc
;
4334 enum charge_type type
= MEM_CGROUP_CHARGE_TYPE_CACHE
;
4336 if (mem_cgroup_disabled())
4339 pc
= lookup_page_cgroup(oldpage
);
4340 /* fix accounting on old pages */
4341 lock_page_cgroup(pc
);
4342 if (PageCgroupUsed(pc
)) {
4343 memcg
= pc
->mem_cgroup
;
4344 mem_cgroup_charge_statistics(memcg
, oldpage
, false, -1);
4345 ClearPageCgroupUsed(pc
);
4347 unlock_page_cgroup(pc
);
4350 * When called from shmem_replace_page(), in some cases the
4351 * oldpage has already been charged, and in some cases not.
4356 * Even if newpage->mapping was NULL before starting replacement,
4357 * the newpage may be on LRU(or pagevec for LRU) already. We lock
4358 * LRU while we overwrite pc->mem_cgroup.
4360 __mem_cgroup_commit_charge(memcg
, newpage
, 1, type
, true);
4363 #ifdef CONFIG_DEBUG_VM
4364 static struct page_cgroup
*lookup_page_cgroup_used(struct page
*page
)
4366 struct page_cgroup
*pc
;
4368 pc
= lookup_page_cgroup(page
);
4370 * Can be NULL while feeding pages into the page allocator for
4371 * the first time, i.e. during boot or memory hotplug;
4372 * or when mem_cgroup_disabled().
4374 if (likely(pc
) && PageCgroupUsed(pc
))
4379 bool mem_cgroup_bad_page_check(struct page
*page
)
4381 if (mem_cgroup_disabled())
4384 return lookup_page_cgroup_used(page
) != NULL
;
4387 void mem_cgroup_print_bad_page(struct page
*page
)
4389 struct page_cgroup
*pc
;
4391 pc
= lookup_page_cgroup_used(page
);
4393 pr_alert("pc:%p pc->flags:%lx pc->mem_cgroup:%p\n",
4394 pc
, pc
->flags
, pc
->mem_cgroup
);
4399 static int mem_cgroup_resize_limit(struct mem_cgroup
*memcg
,
4400 unsigned long long val
)
4403 u64 memswlimit
, memlimit
;
4405 int children
= mem_cgroup_count_children(memcg
);
4406 u64 curusage
, oldusage
;
4410 * For keeping hierarchical_reclaim simple, how long we should retry
4411 * is depends on callers. We set our retry-count to be function
4412 * of # of children which we should visit in this loop.
4414 retry_count
= MEM_CGROUP_RECLAIM_RETRIES
* children
;
4416 oldusage
= res_counter_read_u64(&memcg
->res
, RES_USAGE
);
4419 while (retry_count
) {
4420 if (signal_pending(current
)) {
4425 * Rather than hide all in some function, I do this in
4426 * open coded manner. You see what this really does.
4427 * We have to guarantee memcg->res.limit <= memcg->memsw.limit.
4429 mutex_lock(&set_limit_mutex
);
4430 memswlimit
= res_counter_read_u64(&memcg
->memsw
, RES_LIMIT
);
4431 if (memswlimit
< val
) {
4433 mutex_unlock(&set_limit_mutex
);
4437 memlimit
= res_counter_read_u64(&memcg
->res
, RES_LIMIT
);
4441 ret
= res_counter_set_limit(&memcg
->res
, val
);
4443 if (memswlimit
== val
)
4444 memcg
->memsw_is_minimum
= true;
4446 memcg
->memsw_is_minimum
= false;
4448 mutex_unlock(&set_limit_mutex
);
4453 mem_cgroup_reclaim(memcg
, GFP_KERNEL
,
4454 MEM_CGROUP_RECLAIM_SHRINK
);
4455 curusage
= res_counter_read_u64(&memcg
->res
, RES_USAGE
);
4456 /* Usage is reduced ? */
4457 if (curusage
>= oldusage
)
4460 oldusage
= curusage
;
4462 if (!ret
&& enlarge
)
4463 memcg_oom_recover(memcg
);
4468 static int mem_cgroup_resize_memsw_limit(struct mem_cgroup
*memcg
,
4469 unsigned long long val
)
4472 u64 memlimit
, memswlimit
, oldusage
, curusage
;
4473 int children
= mem_cgroup_count_children(memcg
);
4477 /* see mem_cgroup_resize_res_limit */
4478 retry_count
= children
* MEM_CGROUP_RECLAIM_RETRIES
;
4479 oldusage
= res_counter_read_u64(&memcg
->memsw
, RES_USAGE
);
4480 while (retry_count
) {
4481 if (signal_pending(current
)) {
4486 * Rather than hide all in some function, I do this in
4487 * open coded manner. You see what this really does.
4488 * We have to guarantee memcg->res.limit <= memcg->memsw.limit.
4490 mutex_lock(&set_limit_mutex
);
4491 memlimit
= res_counter_read_u64(&memcg
->res
, RES_LIMIT
);
4492 if (memlimit
> val
) {
4494 mutex_unlock(&set_limit_mutex
);
4497 memswlimit
= res_counter_read_u64(&memcg
->memsw
, RES_LIMIT
);
4498 if (memswlimit
< val
)
4500 ret
= res_counter_set_limit(&memcg
->memsw
, val
);
4502 if (memlimit
== val
)
4503 memcg
->memsw_is_minimum
= true;
4505 memcg
->memsw_is_minimum
= false;
4507 mutex_unlock(&set_limit_mutex
);
4512 mem_cgroup_reclaim(memcg
, GFP_KERNEL
,
4513 MEM_CGROUP_RECLAIM_NOSWAP
|
4514 MEM_CGROUP_RECLAIM_SHRINK
);
4515 curusage
= res_counter_read_u64(&memcg
->memsw
, RES_USAGE
);
4516 /* Usage is reduced ? */
4517 if (curusage
>= oldusage
)
4520 oldusage
= curusage
;
4522 if (!ret
&& enlarge
)
4523 memcg_oom_recover(memcg
);
4527 unsigned long mem_cgroup_soft_limit_reclaim(struct zone
*zone
, int order
,
4529 unsigned long *total_scanned
)
4531 unsigned long nr_reclaimed
= 0;
4532 struct mem_cgroup_per_zone
*mz
, *next_mz
= NULL
;
4533 unsigned long reclaimed
;
4535 struct mem_cgroup_tree_per_zone
*mctz
;
4536 unsigned long long excess
;
4537 unsigned long nr_scanned
;
4542 mctz
= soft_limit_tree_node_zone(zone_to_nid(zone
), zone_idx(zone
));
4544 * This loop can run a while, specially if mem_cgroup's continuously
4545 * keep exceeding their soft limit and putting the system under
4552 mz
= mem_cgroup_largest_soft_limit_node(mctz
);
4557 reclaimed
= mem_cgroup_soft_reclaim(mz
->memcg
, zone
,
4558 gfp_mask
, &nr_scanned
);
4559 nr_reclaimed
+= reclaimed
;
4560 *total_scanned
+= nr_scanned
;
4561 spin_lock(&mctz
->lock
);
4564 * If we failed to reclaim anything from this memory cgroup
4565 * it is time to move on to the next cgroup
4571 * Loop until we find yet another one.
4573 * By the time we get the soft_limit lock
4574 * again, someone might have aded the
4575 * group back on the RB tree. Iterate to
4576 * make sure we get a different mem.
4577 * mem_cgroup_largest_soft_limit_node returns
4578 * NULL if no other cgroup is present on
4582 __mem_cgroup_largest_soft_limit_node(mctz
);
4584 css_put(&next_mz
->memcg
->css
);
4585 else /* next_mz == NULL or other memcg */
4589 __mem_cgroup_remove_exceeded(mz
->memcg
, mz
, mctz
);
4590 excess
= res_counter_soft_limit_excess(&mz
->memcg
->res
);
4592 * One school of thought says that we should not add
4593 * back the node to the tree if reclaim returns 0.
4594 * But our reclaim could return 0, simply because due
4595 * to priority we are exposing a smaller subset of
4596 * memory to reclaim from. Consider this as a longer
4599 /* If excess == 0, no tree ops */
4600 __mem_cgroup_insert_exceeded(mz
->memcg
, mz
, mctz
, excess
);
4601 spin_unlock(&mctz
->lock
);
4602 css_put(&mz
->memcg
->css
);
4605 * Could not reclaim anything and there are no more
4606 * mem cgroups to try or we seem to be looping without
4607 * reclaiming anything.
4609 if (!nr_reclaimed
&&
4611 loop
> MEM_CGROUP_MAX_SOFT_LIMIT_RECLAIM_LOOPS
))
4613 } while (!nr_reclaimed
);
4615 css_put(&next_mz
->memcg
->css
);
4616 return nr_reclaimed
;
4620 * mem_cgroup_force_empty_list - clears LRU of a group
4621 * @memcg: group to clear
4624 * @lru: lru to to clear
4626 * Traverse a specified page_cgroup list and try to drop them all. This doesn't
4627 * reclaim the pages page themselves - pages are moved to the parent (or root)
4630 static void mem_cgroup_force_empty_list(struct mem_cgroup
*memcg
,
4631 int node
, int zid
, enum lru_list lru
)
4633 struct lruvec
*lruvec
;
4634 unsigned long flags
;
4635 struct list_head
*list
;
4639 zone
= &NODE_DATA(node
)->node_zones
[zid
];
4640 lruvec
= mem_cgroup_zone_lruvec(zone
, memcg
);
4641 list
= &lruvec
->lists
[lru
];
4645 struct page_cgroup
*pc
;
4648 spin_lock_irqsave(&zone
->lru_lock
, flags
);
4649 if (list_empty(list
)) {
4650 spin_unlock_irqrestore(&zone
->lru_lock
, flags
);
4653 page
= list_entry(list
->prev
, struct page
, lru
);
4655 list_move(&page
->lru
, list
);
4657 spin_unlock_irqrestore(&zone
->lru_lock
, flags
);
4660 spin_unlock_irqrestore(&zone
->lru_lock
, flags
);
4662 pc
= lookup_page_cgroup(page
);
4664 if (mem_cgroup_move_parent(page
, pc
, memcg
)) {
4665 /* found lock contention or "pc" is obsolete. */
4670 } while (!list_empty(list
));
4674 * make mem_cgroup's charge to be 0 if there is no task by moving
4675 * all the charges and pages to the parent.
4676 * This enables deleting this mem_cgroup.
4678 * Caller is responsible for holding css reference on the memcg.
4680 static void mem_cgroup_reparent_charges(struct mem_cgroup
*memcg
)
4686 /* This is for making all *used* pages to be on LRU. */
4687 lru_add_drain_all();
4688 drain_all_stock_sync(memcg
);
4689 mem_cgroup_start_move(memcg
);
4690 for_each_node_state(node
, N_MEMORY
) {
4691 for (zid
= 0; zid
< MAX_NR_ZONES
; zid
++) {
4694 mem_cgroup_force_empty_list(memcg
,
4699 mem_cgroup_end_move(memcg
);
4700 memcg_oom_recover(memcg
);
4704 * Kernel memory may not necessarily be trackable to a specific
4705 * process. So they are not migrated, and therefore we can't
4706 * expect their value to drop to 0 here.
4707 * Having res filled up with kmem only is enough.
4709 * This is a safety check because mem_cgroup_force_empty_list
4710 * could have raced with mem_cgroup_replace_page_cache callers
4711 * so the lru seemed empty but the page could have been added
4712 * right after the check. RES_USAGE should be safe as we always
4713 * charge before adding to the LRU.
4715 usage
= res_counter_read_u64(&memcg
->res
, RES_USAGE
) -
4716 res_counter_read_u64(&memcg
->kmem
, RES_USAGE
);
4717 } while (usage
> 0);
4720 static inline bool memcg_has_children(struct mem_cgroup
*memcg
)
4722 lockdep_assert_held(&memcg_create_mutex
);
4724 * The lock does not prevent addition or deletion to the list
4725 * of children, but it prevents a new child from being
4726 * initialized based on this parent in css_online(), so it's
4727 * enough to decide whether hierarchically inherited
4728 * attributes can still be changed or not.
4730 return memcg
->use_hierarchy
&&
4731 !list_empty(&memcg
->css
.cgroup
->children
);
4735 * Reclaims as many pages from the given memcg as possible and moves
4736 * the rest to the parent.
4738 * Caller is responsible for holding css reference for memcg.
4740 static int mem_cgroup_force_empty(struct mem_cgroup
*memcg
)
4742 int nr_retries
= MEM_CGROUP_RECLAIM_RETRIES
;
4743 struct cgroup
*cgrp
= memcg
->css
.cgroup
;
4745 /* returns EBUSY if there is a task or if we come here twice. */
4746 if (cgroup_has_tasks(cgrp
) || !list_empty(&cgrp
->children
))
4749 /* we call try-to-free pages for make this cgroup empty */
4750 lru_add_drain_all();
4751 /* try to free all pages in this cgroup */
4752 while (nr_retries
&& res_counter_read_u64(&memcg
->res
, RES_USAGE
) > 0) {
4755 if (signal_pending(current
))
4758 progress
= try_to_free_mem_cgroup_pages(memcg
, GFP_KERNEL
,
4762 /* maybe some writeback is necessary */
4763 congestion_wait(BLK_RW_ASYNC
, HZ
/10);
4768 mem_cgroup_reparent_charges(memcg
);
4773 static int mem_cgroup_force_empty_write(struct cgroup_subsys_state
*css
,
4776 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
4778 if (mem_cgroup_is_root(memcg
))
4780 return mem_cgroup_force_empty(memcg
);
4783 static u64
mem_cgroup_hierarchy_read(struct cgroup_subsys_state
*css
,
4786 return mem_cgroup_from_css(css
)->use_hierarchy
;
4789 static int mem_cgroup_hierarchy_write(struct cgroup_subsys_state
*css
,
4790 struct cftype
*cft
, u64 val
)
4793 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
4794 struct mem_cgroup
*parent_memcg
= mem_cgroup_from_css(css_parent(&memcg
->css
));
4796 mutex_lock(&memcg_create_mutex
);
4798 if (memcg
->use_hierarchy
== val
)
4802 * If parent's use_hierarchy is set, we can't make any modifications
4803 * in the child subtrees. If it is unset, then the change can
4804 * occur, provided the current cgroup has no children.
4806 * For the root cgroup, parent_mem is NULL, we allow value to be
4807 * set if there are no children.
4809 if ((!parent_memcg
|| !parent_memcg
->use_hierarchy
) &&
4810 (val
== 1 || val
== 0)) {
4811 if (list_empty(&memcg
->css
.cgroup
->children
))
4812 memcg
->use_hierarchy
= val
;
4819 mutex_unlock(&memcg_create_mutex
);
4825 static unsigned long mem_cgroup_recursive_stat(struct mem_cgroup
*memcg
,
4826 enum mem_cgroup_stat_index idx
)
4828 struct mem_cgroup
*iter
;
4831 /* Per-cpu values can be negative, use a signed accumulator */
4832 for_each_mem_cgroup_tree(iter
, memcg
)
4833 val
+= mem_cgroup_read_stat(iter
, idx
);
4835 if (val
< 0) /* race ? */
4840 static inline u64
mem_cgroup_usage(struct mem_cgroup
*memcg
, bool swap
)
4844 if (!mem_cgroup_is_root(memcg
)) {
4846 return res_counter_read_u64(&memcg
->res
, RES_USAGE
);
4848 return res_counter_read_u64(&memcg
->memsw
, RES_USAGE
);
4852 * Transparent hugepages are still accounted for in MEM_CGROUP_STAT_RSS
4853 * as well as in MEM_CGROUP_STAT_RSS_HUGE.
4855 val
= mem_cgroup_recursive_stat(memcg
, MEM_CGROUP_STAT_CACHE
);
4856 val
+= mem_cgroup_recursive_stat(memcg
, MEM_CGROUP_STAT_RSS
);
4859 val
+= mem_cgroup_recursive_stat(memcg
, MEM_CGROUP_STAT_SWAP
);
4861 return val
<< PAGE_SHIFT
;
4864 static u64
mem_cgroup_read_u64(struct cgroup_subsys_state
*css
,
4867 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
4872 type
= MEMFILE_TYPE(cft
->private);
4873 name
= MEMFILE_ATTR(cft
->private);
4877 if (name
== RES_USAGE
)
4878 val
= mem_cgroup_usage(memcg
, false);
4880 val
= res_counter_read_u64(&memcg
->res
, name
);
4883 if (name
== RES_USAGE
)
4884 val
= mem_cgroup_usage(memcg
, true);
4886 val
= res_counter_read_u64(&memcg
->memsw
, name
);
4889 val
= res_counter_read_u64(&memcg
->kmem
, name
);
4898 #ifdef CONFIG_MEMCG_KMEM
4899 /* should be called with activate_kmem_mutex held */
4900 static int __memcg_activate_kmem(struct mem_cgroup
*memcg
,
4901 unsigned long long limit
)
4906 if (memcg_kmem_is_active(memcg
))
4910 * We are going to allocate memory for data shared by all memory
4911 * cgroups so let's stop accounting here.
4913 memcg_stop_kmem_account();
4916 * For simplicity, we won't allow this to be disabled. It also can't
4917 * be changed if the cgroup has children already, or if tasks had
4920 * If tasks join before we set the limit, a person looking at
4921 * kmem.usage_in_bytes will have no way to determine when it took
4922 * place, which makes the value quite meaningless.
4924 * After it first became limited, changes in the value of the limit are
4925 * of course permitted.
4927 mutex_lock(&memcg_create_mutex
);
4928 if (cgroup_has_tasks(memcg
->css
.cgroup
) || memcg_has_children(memcg
))
4930 mutex_unlock(&memcg_create_mutex
);
4934 memcg_id
= ida_simple_get(&kmem_limited_groups
,
4935 0, MEMCG_CACHES_MAX_SIZE
, GFP_KERNEL
);
4942 * Make sure we have enough space for this cgroup in each root cache's
4945 mutex_lock(&memcg_slab_mutex
);
4946 err
= memcg_update_all_caches(memcg_id
+ 1);
4947 mutex_unlock(&memcg_slab_mutex
);
4951 memcg
->kmemcg_id
= memcg_id
;
4952 INIT_LIST_HEAD(&memcg
->memcg_slab_caches
);
4955 * We couldn't have accounted to this cgroup, because it hasn't got the
4956 * active bit set yet, so this should succeed.
4958 err
= res_counter_set_limit(&memcg
->kmem
, limit
);
4961 static_key_slow_inc(&memcg_kmem_enabled_key
);
4963 * Setting the active bit after enabling static branching will
4964 * guarantee no one starts accounting before all call sites are
4967 memcg_kmem_set_active(memcg
);
4969 memcg_resume_kmem_account();
4973 ida_simple_remove(&kmem_limited_groups
, memcg_id
);
4977 static int memcg_activate_kmem(struct mem_cgroup
*memcg
,
4978 unsigned long long limit
)
4982 mutex_lock(&activate_kmem_mutex
);
4983 ret
= __memcg_activate_kmem(memcg
, limit
);
4984 mutex_unlock(&activate_kmem_mutex
);
4988 static int memcg_update_kmem_limit(struct mem_cgroup
*memcg
,
4989 unsigned long long val
)
4993 if (!memcg_kmem_is_active(memcg
))
4994 ret
= memcg_activate_kmem(memcg
, val
);
4996 ret
= res_counter_set_limit(&memcg
->kmem
, val
);
5000 static int memcg_propagate_kmem(struct mem_cgroup
*memcg
)
5003 struct mem_cgroup
*parent
= parent_mem_cgroup(memcg
);
5008 mutex_lock(&activate_kmem_mutex
);
5010 * If the parent cgroup is not kmem-active now, it cannot be activated
5011 * after this point, because it has at least one child already.
5013 if (memcg_kmem_is_active(parent
))
5014 ret
= __memcg_activate_kmem(memcg
, RES_COUNTER_MAX
);
5015 mutex_unlock(&activate_kmem_mutex
);
5019 static int memcg_update_kmem_limit(struct mem_cgroup
*memcg
,
5020 unsigned long long val
)
5024 #endif /* CONFIG_MEMCG_KMEM */
5027 * The user of this function is...
5030 static int mem_cgroup_write(struct cgroup_subsys_state
*css
, struct cftype
*cft
,
5033 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
5036 unsigned long long val
;
5039 type
= MEMFILE_TYPE(cft
->private);
5040 name
= MEMFILE_ATTR(cft
->private);
5044 if (mem_cgroup_is_root(memcg
)) { /* Can't set limit on root */
5048 /* This function does all necessary parse...reuse it */
5049 ret
= res_counter_memparse_write_strategy(buffer
, &val
);
5053 ret
= mem_cgroup_resize_limit(memcg
, val
);
5054 else if (type
== _MEMSWAP
)
5055 ret
= mem_cgroup_resize_memsw_limit(memcg
, val
);
5056 else if (type
== _KMEM
)
5057 ret
= memcg_update_kmem_limit(memcg
, val
);
5061 case RES_SOFT_LIMIT
:
5062 ret
= res_counter_memparse_write_strategy(buffer
, &val
);
5066 * For memsw, soft limits are hard to implement in terms
5067 * of semantics, for now, we support soft limits for
5068 * control without swap
5071 ret
= res_counter_set_soft_limit(&memcg
->res
, val
);
5076 ret
= -EINVAL
; /* should be BUG() ? */
5082 static void memcg_get_hierarchical_limit(struct mem_cgroup
*memcg
,
5083 unsigned long long *mem_limit
, unsigned long long *memsw_limit
)
5085 unsigned long long min_limit
, min_memsw_limit
, tmp
;
5087 min_limit
= res_counter_read_u64(&memcg
->res
, RES_LIMIT
);
5088 min_memsw_limit
= res_counter_read_u64(&memcg
->memsw
, RES_LIMIT
);
5089 if (!memcg
->use_hierarchy
)
5092 while (css_parent(&memcg
->css
)) {
5093 memcg
= mem_cgroup_from_css(css_parent(&memcg
->css
));
5094 if (!memcg
->use_hierarchy
)
5096 tmp
= res_counter_read_u64(&memcg
->res
, RES_LIMIT
);
5097 min_limit
= min(min_limit
, tmp
);
5098 tmp
= res_counter_read_u64(&memcg
->memsw
, RES_LIMIT
);
5099 min_memsw_limit
= min(min_memsw_limit
, tmp
);
5102 *mem_limit
= min_limit
;
5103 *memsw_limit
= min_memsw_limit
;
5106 static int mem_cgroup_reset(struct cgroup_subsys_state
*css
, unsigned int event
)
5108 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
5112 type
= MEMFILE_TYPE(event
);
5113 name
= MEMFILE_ATTR(event
);
5118 res_counter_reset_max(&memcg
->res
);
5119 else if (type
== _MEMSWAP
)
5120 res_counter_reset_max(&memcg
->memsw
);
5121 else if (type
== _KMEM
)
5122 res_counter_reset_max(&memcg
->kmem
);
5128 res_counter_reset_failcnt(&memcg
->res
);
5129 else if (type
== _MEMSWAP
)
5130 res_counter_reset_failcnt(&memcg
->memsw
);
5131 else if (type
== _KMEM
)
5132 res_counter_reset_failcnt(&memcg
->kmem
);
5141 static u64
mem_cgroup_move_charge_read(struct cgroup_subsys_state
*css
,
5144 return mem_cgroup_from_css(css
)->move_charge_at_immigrate
;
5148 static int mem_cgroup_move_charge_write(struct cgroup_subsys_state
*css
,
5149 struct cftype
*cft
, u64 val
)
5151 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
5153 if (val
>= (1 << NR_MOVE_TYPE
))
5157 * No kind of locking is needed in here, because ->can_attach() will
5158 * check this value once in the beginning of the process, and then carry
5159 * on with stale data. This means that changes to this value will only
5160 * affect task migrations starting after the change.
5162 memcg
->move_charge_at_immigrate
= val
;
5166 static int mem_cgroup_move_charge_write(struct cgroup_subsys_state
*css
,
5167 struct cftype
*cft
, u64 val
)
5174 static int memcg_numa_stat_show(struct seq_file
*m
, void *v
)
5178 unsigned int lru_mask
;
5181 static const struct numa_stat stats
[] = {
5182 { "total", LRU_ALL
},
5183 { "file", LRU_ALL_FILE
},
5184 { "anon", LRU_ALL_ANON
},
5185 { "unevictable", BIT(LRU_UNEVICTABLE
) },
5187 const struct numa_stat
*stat
;
5190 struct mem_cgroup
*memcg
= mem_cgroup_from_css(seq_css(m
));
5192 for (stat
= stats
; stat
< stats
+ ARRAY_SIZE(stats
); stat
++) {
5193 nr
= mem_cgroup_nr_lru_pages(memcg
, stat
->lru_mask
);
5194 seq_printf(m
, "%s=%lu", stat
->name
, nr
);
5195 for_each_node_state(nid
, N_MEMORY
) {
5196 nr
= mem_cgroup_node_nr_lru_pages(memcg
, nid
,
5198 seq_printf(m
, " N%d=%lu", nid
, nr
);
5203 for (stat
= stats
; stat
< stats
+ ARRAY_SIZE(stats
); stat
++) {
5204 struct mem_cgroup
*iter
;
5207 for_each_mem_cgroup_tree(iter
, memcg
)
5208 nr
+= mem_cgroup_nr_lru_pages(iter
, stat
->lru_mask
);
5209 seq_printf(m
, "hierarchical_%s=%lu", stat
->name
, nr
);
5210 for_each_node_state(nid
, N_MEMORY
) {
5212 for_each_mem_cgroup_tree(iter
, memcg
)
5213 nr
+= mem_cgroup_node_nr_lru_pages(
5214 iter
, nid
, stat
->lru_mask
);
5215 seq_printf(m
, " N%d=%lu", nid
, nr
);
5222 #endif /* CONFIG_NUMA */
5224 static inline void mem_cgroup_lru_names_not_uptodate(void)
5226 BUILD_BUG_ON(ARRAY_SIZE(mem_cgroup_lru_names
) != NR_LRU_LISTS
);
5229 static int memcg_stat_show(struct seq_file
*m
, void *v
)
5231 struct mem_cgroup
*memcg
= mem_cgroup_from_css(seq_css(m
));
5232 struct mem_cgroup
*mi
;
5235 for (i
= 0; i
< MEM_CGROUP_STAT_NSTATS
; i
++) {
5236 if (i
== MEM_CGROUP_STAT_SWAP
&& !do_swap_account
)
5238 seq_printf(m
, "%s %ld\n", mem_cgroup_stat_names
[i
],
5239 mem_cgroup_read_stat(memcg
, i
) * PAGE_SIZE
);
5242 for (i
= 0; i
< MEM_CGROUP_EVENTS_NSTATS
; i
++)
5243 seq_printf(m
, "%s %lu\n", mem_cgroup_events_names
[i
],
5244 mem_cgroup_read_events(memcg
, i
));
5246 for (i
= 0; i
< NR_LRU_LISTS
; i
++)
5247 seq_printf(m
, "%s %lu\n", mem_cgroup_lru_names
[i
],
5248 mem_cgroup_nr_lru_pages(memcg
, BIT(i
)) * PAGE_SIZE
);
5250 /* Hierarchical information */
5252 unsigned long long limit
, memsw_limit
;
5253 memcg_get_hierarchical_limit(memcg
, &limit
, &memsw_limit
);
5254 seq_printf(m
, "hierarchical_memory_limit %llu\n", limit
);
5255 if (do_swap_account
)
5256 seq_printf(m
, "hierarchical_memsw_limit %llu\n",
5260 for (i
= 0; i
< MEM_CGROUP_STAT_NSTATS
; i
++) {
5263 if (i
== MEM_CGROUP_STAT_SWAP
&& !do_swap_account
)
5265 for_each_mem_cgroup_tree(mi
, memcg
)
5266 val
+= mem_cgroup_read_stat(mi
, i
) * PAGE_SIZE
;
5267 seq_printf(m
, "total_%s %lld\n", mem_cgroup_stat_names
[i
], val
);
5270 for (i
= 0; i
< MEM_CGROUP_EVENTS_NSTATS
; i
++) {
5271 unsigned long long val
= 0;
5273 for_each_mem_cgroup_tree(mi
, memcg
)
5274 val
+= mem_cgroup_read_events(mi
, i
);
5275 seq_printf(m
, "total_%s %llu\n",
5276 mem_cgroup_events_names
[i
], val
);
5279 for (i
= 0; i
< NR_LRU_LISTS
; i
++) {
5280 unsigned long long val
= 0;
5282 for_each_mem_cgroup_tree(mi
, memcg
)
5283 val
+= mem_cgroup_nr_lru_pages(mi
, BIT(i
)) * PAGE_SIZE
;
5284 seq_printf(m
, "total_%s %llu\n", mem_cgroup_lru_names
[i
], val
);
5287 #ifdef CONFIG_DEBUG_VM
5290 struct mem_cgroup_per_zone
*mz
;
5291 struct zone_reclaim_stat
*rstat
;
5292 unsigned long recent_rotated
[2] = {0, 0};
5293 unsigned long recent_scanned
[2] = {0, 0};
5295 for_each_online_node(nid
)
5296 for (zid
= 0; zid
< MAX_NR_ZONES
; zid
++) {
5297 mz
= &memcg
->nodeinfo
[nid
]->zoneinfo
[zid
];
5298 rstat
= &mz
->lruvec
.reclaim_stat
;
5300 recent_rotated
[0] += rstat
->recent_rotated
[0];
5301 recent_rotated
[1] += rstat
->recent_rotated
[1];
5302 recent_scanned
[0] += rstat
->recent_scanned
[0];
5303 recent_scanned
[1] += rstat
->recent_scanned
[1];
5305 seq_printf(m
, "recent_rotated_anon %lu\n", recent_rotated
[0]);
5306 seq_printf(m
, "recent_rotated_file %lu\n", recent_rotated
[1]);
5307 seq_printf(m
, "recent_scanned_anon %lu\n", recent_scanned
[0]);
5308 seq_printf(m
, "recent_scanned_file %lu\n", recent_scanned
[1]);
5315 static u64
mem_cgroup_swappiness_read(struct cgroup_subsys_state
*css
,
5318 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
5320 return mem_cgroup_swappiness(memcg
);
5323 static int mem_cgroup_swappiness_write(struct cgroup_subsys_state
*css
,
5324 struct cftype
*cft
, u64 val
)
5326 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
5331 if (css_parent(css
))
5332 memcg
->swappiness
= val
;
5334 vm_swappiness
= val
;
5339 static void __mem_cgroup_threshold(struct mem_cgroup
*memcg
, bool swap
)
5341 struct mem_cgroup_threshold_ary
*t
;
5347 t
= rcu_dereference(memcg
->thresholds
.primary
);
5349 t
= rcu_dereference(memcg
->memsw_thresholds
.primary
);
5354 usage
= mem_cgroup_usage(memcg
, swap
);
5357 * current_threshold points to threshold just below or equal to usage.
5358 * If it's not true, a threshold was crossed after last
5359 * call of __mem_cgroup_threshold().
5361 i
= t
->current_threshold
;
5364 * Iterate backward over array of thresholds starting from
5365 * current_threshold and check if a threshold is crossed.
5366 * If none of thresholds below usage is crossed, we read
5367 * only one element of the array here.
5369 for (; i
>= 0 && unlikely(t
->entries
[i
].threshold
> usage
); i
--)
5370 eventfd_signal(t
->entries
[i
].eventfd
, 1);
5372 /* i = current_threshold + 1 */
5376 * Iterate forward over array of thresholds starting from
5377 * current_threshold+1 and check if a threshold is crossed.
5378 * If none of thresholds above usage is crossed, we read
5379 * only one element of the array here.
5381 for (; i
< t
->size
&& unlikely(t
->entries
[i
].threshold
<= usage
); i
++)
5382 eventfd_signal(t
->entries
[i
].eventfd
, 1);
5384 /* Update current_threshold */
5385 t
->current_threshold
= i
- 1;
5390 static void mem_cgroup_threshold(struct mem_cgroup
*memcg
)
5393 __mem_cgroup_threshold(memcg
, false);
5394 if (do_swap_account
)
5395 __mem_cgroup_threshold(memcg
, true);
5397 memcg
= parent_mem_cgroup(memcg
);
5401 static int compare_thresholds(const void *a
, const void *b
)
5403 const struct mem_cgroup_threshold
*_a
= a
;
5404 const struct mem_cgroup_threshold
*_b
= b
;
5406 if (_a
->threshold
> _b
->threshold
)
5409 if (_a
->threshold
< _b
->threshold
)
5415 static int mem_cgroup_oom_notify_cb(struct mem_cgroup
*memcg
)
5417 struct mem_cgroup_eventfd_list
*ev
;
5419 list_for_each_entry(ev
, &memcg
->oom_notify
, list
)
5420 eventfd_signal(ev
->eventfd
, 1);
5424 static void mem_cgroup_oom_notify(struct mem_cgroup
*memcg
)
5426 struct mem_cgroup
*iter
;
5428 for_each_mem_cgroup_tree(iter
, memcg
)
5429 mem_cgroup_oom_notify_cb(iter
);
5432 static int __mem_cgroup_usage_register_event(struct mem_cgroup
*memcg
,
5433 struct eventfd_ctx
*eventfd
, const char *args
, enum res_type type
)
5435 struct mem_cgroup_thresholds
*thresholds
;
5436 struct mem_cgroup_threshold_ary
*new;
5437 u64 threshold
, usage
;
5440 ret
= res_counter_memparse_write_strategy(args
, &threshold
);
5444 mutex_lock(&memcg
->thresholds_lock
);
5447 thresholds
= &memcg
->thresholds
;
5448 else if (type
== _MEMSWAP
)
5449 thresholds
= &memcg
->memsw_thresholds
;
5453 usage
= mem_cgroup_usage(memcg
, type
== _MEMSWAP
);
5455 /* Check if a threshold crossed before adding a new one */
5456 if (thresholds
->primary
)
5457 __mem_cgroup_threshold(memcg
, type
== _MEMSWAP
);
5459 size
= thresholds
->primary
? thresholds
->primary
->size
+ 1 : 1;
5461 /* Allocate memory for new array of thresholds */
5462 new = kmalloc(sizeof(*new) + size
* sizeof(struct mem_cgroup_threshold
),
5470 /* Copy thresholds (if any) to new array */
5471 if (thresholds
->primary
) {
5472 memcpy(new->entries
, thresholds
->primary
->entries
, (size
- 1) *
5473 sizeof(struct mem_cgroup_threshold
));
5476 /* Add new threshold */
5477 new->entries
[size
- 1].eventfd
= eventfd
;
5478 new->entries
[size
- 1].threshold
= threshold
;
5480 /* Sort thresholds. Registering of new threshold isn't time-critical */
5481 sort(new->entries
, size
, sizeof(struct mem_cgroup_threshold
),
5482 compare_thresholds
, NULL
);
5484 /* Find current threshold */
5485 new->current_threshold
= -1;
5486 for (i
= 0; i
< size
; i
++) {
5487 if (new->entries
[i
].threshold
<= usage
) {
5489 * new->current_threshold will not be used until
5490 * rcu_assign_pointer(), so it's safe to increment
5493 ++new->current_threshold
;
5498 /* Free old spare buffer and save old primary buffer as spare */
5499 kfree(thresholds
->spare
);
5500 thresholds
->spare
= thresholds
->primary
;
5502 rcu_assign_pointer(thresholds
->primary
, new);
5504 /* To be sure that nobody uses thresholds */
5508 mutex_unlock(&memcg
->thresholds_lock
);
5513 static int mem_cgroup_usage_register_event(struct mem_cgroup
*memcg
,
5514 struct eventfd_ctx
*eventfd
, const char *args
)
5516 return __mem_cgroup_usage_register_event(memcg
, eventfd
, args
, _MEM
);
5519 static int memsw_cgroup_usage_register_event(struct mem_cgroup
*memcg
,
5520 struct eventfd_ctx
*eventfd
, const char *args
)
5522 return __mem_cgroup_usage_register_event(memcg
, eventfd
, args
, _MEMSWAP
);
5525 static void __mem_cgroup_usage_unregister_event(struct mem_cgroup
*memcg
,
5526 struct eventfd_ctx
*eventfd
, enum res_type type
)
5528 struct mem_cgroup_thresholds
*thresholds
;
5529 struct mem_cgroup_threshold_ary
*new;
5533 mutex_lock(&memcg
->thresholds_lock
);
5535 thresholds
= &memcg
->thresholds
;
5536 else if (type
== _MEMSWAP
)
5537 thresholds
= &memcg
->memsw_thresholds
;
5541 if (!thresholds
->primary
)
5544 usage
= mem_cgroup_usage(memcg
, type
== _MEMSWAP
);
5546 /* Check if a threshold crossed before removing */
5547 __mem_cgroup_threshold(memcg
, type
== _MEMSWAP
);
5549 /* Calculate new number of threshold */
5551 for (i
= 0; i
< thresholds
->primary
->size
; i
++) {
5552 if (thresholds
->primary
->entries
[i
].eventfd
!= eventfd
)
5556 new = thresholds
->spare
;
5558 /* Set thresholds array to NULL if we don't have thresholds */
5567 /* Copy thresholds and find current threshold */
5568 new->current_threshold
= -1;
5569 for (i
= 0, j
= 0; i
< thresholds
->primary
->size
; i
++) {
5570 if (thresholds
->primary
->entries
[i
].eventfd
== eventfd
)
5573 new->entries
[j
] = thresholds
->primary
->entries
[i
];
5574 if (new->entries
[j
].threshold
<= usage
) {
5576 * new->current_threshold will not be used
5577 * until rcu_assign_pointer(), so it's safe to increment
5580 ++new->current_threshold
;
5586 /* Swap primary and spare array */
5587 thresholds
->spare
= thresholds
->primary
;
5588 /* If all events are unregistered, free the spare array */
5590 kfree(thresholds
->spare
);
5591 thresholds
->spare
= NULL
;
5594 rcu_assign_pointer(thresholds
->primary
, new);
5596 /* To be sure that nobody uses thresholds */
5599 mutex_unlock(&memcg
->thresholds_lock
);
5602 static void mem_cgroup_usage_unregister_event(struct mem_cgroup
*memcg
,
5603 struct eventfd_ctx
*eventfd
)
5605 return __mem_cgroup_usage_unregister_event(memcg
, eventfd
, _MEM
);
5608 static void memsw_cgroup_usage_unregister_event(struct mem_cgroup
*memcg
,
5609 struct eventfd_ctx
*eventfd
)
5611 return __mem_cgroup_usage_unregister_event(memcg
, eventfd
, _MEMSWAP
);
5614 static int mem_cgroup_oom_register_event(struct mem_cgroup
*memcg
,
5615 struct eventfd_ctx
*eventfd
, const char *args
)
5617 struct mem_cgroup_eventfd_list
*event
;
5619 event
= kmalloc(sizeof(*event
), GFP_KERNEL
);
5623 spin_lock(&memcg_oom_lock
);
5625 event
->eventfd
= eventfd
;
5626 list_add(&event
->list
, &memcg
->oom_notify
);
5628 /* already in OOM ? */
5629 if (atomic_read(&memcg
->under_oom
))
5630 eventfd_signal(eventfd
, 1);
5631 spin_unlock(&memcg_oom_lock
);
5636 static void mem_cgroup_oom_unregister_event(struct mem_cgroup
*memcg
,
5637 struct eventfd_ctx
*eventfd
)
5639 struct mem_cgroup_eventfd_list
*ev
, *tmp
;
5641 spin_lock(&memcg_oom_lock
);
5643 list_for_each_entry_safe(ev
, tmp
, &memcg
->oom_notify
, list
) {
5644 if (ev
->eventfd
== eventfd
) {
5645 list_del(&ev
->list
);
5650 spin_unlock(&memcg_oom_lock
);
5653 static int mem_cgroup_oom_control_read(struct seq_file
*sf
, void *v
)
5655 struct mem_cgroup
*memcg
= mem_cgroup_from_css(seq_css(sf
));
5657 seq_printf(sf
, "oom_kill_disable %d\n", memcg
->oom_kill_disable
);
5658 seq_printf(sf
, "under_oom %d\n", (bool)atomic_read(&memcg
->under_oom
));
5662 static int mem_cgroup_oom_control_write(struct cgroup_subsys_state
*css
,
5663 struct cftype
*cft
, u64 val
)
5665 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
5667 /* cannot set to root cgroup and only 0 and 1 are allowed */
5668 if (!css_parent(css
) || !((val
== 0) || (val
== 1)))
5671 memcg
->oom_kill_disable
= val
;
5673 memcg_oom_recover(memcg
);
5678 #ifdef CONFIG_MEMCG_KMEM
5679 static int memcg_init_kmem(struct mem_cgroup
*memcg
, struct cgroup_subsys
*ss
)
5683 memcg
->kmemcg_id
= -1;
5684 ret
= memcg_propagate_kmem(memcg
);
5688 return mem_cgroup_sockets_init(memcg
, ss
);
5691 static void memcg_destroy_kmem(struct mem_cgroup
*memcg
)
5693 mem_cgroup_sockets_destroy(memcg
);
5696 static void kmem_cgroup_css_offline(struct mem_cgroup
*memcg
)
5698 if (!memcg_kmem_is_active(memcg
))
5702 * kmem charges can outlive the cgroup. In the case of slab
5703 * pages, for instance, a page contain objects from various
5704 * processes. As we prevent from taking a reference for every
5705 * such allocation we have to be careful when doing uncharge
5706 * (see memcg_uncharge_kmem) and here during offlining.
5708 * The idea is that that only the _last_ uncharge which sees
5709 * the dead memcg will drop the last reference. An additional
5710 * reference is taken here before the group is marked dead
5711 * which is then paired with css_put during uncharge resp. here.
5713 * Although this might sound strange as this path is called from
5714 * css_offline() when the referencemight have dropped down to 0
5715 * and shouldn't be incremented anymore (css_tryget would fail)
5716 * we do not have other options because of the kmem allocations
5719 css_get(&memcg
->css
);
5721 memcg_kmem_mark_dead(memcg
);
5723 if (res_counter_read_u64(&memcg
->kmem
, RES_USAGE
) != 0)
5726 if (memcg_kmem_test_and_clear_dead(memcg
))
5727 css_put(&memcg
->css
);
5730 static int memcg_init_kmem(struct mem_cgroup
*memcg
, struct cgroup_subsys
*ss
)
5735 static void memcg_destroy_kmem(struct mem_cgroup
*memcg
)
5739 static void kmem_cgroup_css_offline(struct mem_cgroup
*memcg
)
5745 * DO NOT USE IN NEW FILES.
5747 * "cgroup.event_control" implementation.
5749 * This is way over-engineered. It tries to support fully configurable
5750 * events for each user. Such level of flexibility is completely
5751 * unnecessary especially in the light of the planned unified hierarchy.
5753 * Please deprecate this and replace with something simpler if at all
5758 * Unregister event and free resources.
5760 * Gets called from workqueue.
5762 static void memcg_event_remove(struct work_struct
*work
)
5764 struct mem_cgroup_event
*event
=
5765 container_of(work
, struct mem_cgroup_event
, remove
);
5766 struct mem_cgroup
*memcg
= event
->memcg
;
5768 remove_wait_queue(event
->wqh
, &event
->wait
);
5770 event
->unregister_event(memcg
, event
->eventfd
);
5772 /* Notify userspace the event is going away. */
5773 eventfd_signal(event
->eventfd
, 1);
5775 eventfd_ctx_put(event
->eventfd
);
5777 css_put(&memcg
->css
);
5781 * Gets called on POLLHUP on eventfd when user closes it.
5783 * Called with wqh->lock held and interrupts disabled.
5785 static int memcg_event_wake(wait_queue_t
*wait
, unsigned mode
,
5786 int sync
, void *key
)
5788 struct mem_cgroup_event
*event
=
5789 container_of(wait
, struct mem_cgroup_event
, wait
);
5790 struct mem_cgroup
*memcg
= event
->memcg
;
5791 unsigned long flags
= (unsigned long)key
;
5793 if (flags
& POLLHUP
) {
5795 * If the event has been detached at cgroup removal, we
5796 * can simply return knowing the other side will cleanup
5799 * We can't race against event freeing since the other
5800 * side will require wqh->lock via remove_wait_queue(),
5803 spin_lock(&memcg
->event_list_lock
);
5804 if (!list_empty(&event
->list
)) {
5805 list_del_init(&event
->list
);
5807 * We are in atomic context, but cgroup_event_remove()
5808 * may sleep, so we have to call it in workqueue.
5810 schedule_work(&event
->remove
);
5812 spin_unlock(&memcg
->event_list_lock
);
5818 static void memcg_event_ptable_queue_proc(struct file
*file
,
5819 wait_queue_head_t
*wqh
, poll_table
*pt
)
5821 struct mem_cgroup_event
*event
=
5822 container_of(pt
, struct mem_cgroup_event
, pt
);
5825 add_wait_queue(wqh
, &event
->wait
);
5829 * DO NOT USE IN NEW FILES.
5831 * Parse input and register new cgroup event handler.
5833 * Input must be in format '<event_fd> <control_fd> <args>'.
5834 * Interpretation of args is defined by control file implementation.
5836 static int memcg_write_event_control(struct cgroup_subsys_state
*css
,
5837 struct cftype
*cft
, char *buffer
)
5839 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
5840 struct mem_cgroup_event
*event
;
5841 struct cgroup_subsys_state
*cfile_css
;
5842 unsigned int efd
, cfd
;
5849 efd
= simple_strtoul(buffer
, &endp
, 10);
5854 cfd
= simple_strtoul(buffer
, &endp
, 10);
5855 if ((*endp
!= ' ') && (*endp
!= '\0'))
5859 event
= kzalloc(sizeof(*event
), GFP_KERNEL
);
5863 event
->memcg
= memcg
;
5864 INIT_LIST_HEAD(&event
->list
);
5865 init_poll_funcptr(&event
->pt
, memcg_event_ptable_queue_proc
);
5866 init_waitqueue_func_entry(&event
->wait
, memcg_event_wake
);
5867 INIT_WORK(&event
->remove
, memcg_event_remove
);
5875 event
->eventfd
= eventfd_ctx_fileget(efile
.file
);
5876 if (IS_ERR(event
->eventfd
)) {
5877 ret
= PTR_ERR(event
->eventfd
);
5884 goto out_put_eventfd
;
5887 /* the process need read permission on control file */
5888 /* AV: shouldn't we check that it's been opened for read instead? */
5889 ret
= inode_permission(file_inode(cfile
.file
), MAY_READ
);
5894 * Determine the event callbacks and set them in @event. This used
5895 * to be done via struct cftype but cgroup core no longer knows
5896 * about these events. The following is crude but the whole thing
5897 * is for compatibility anyway.
5899 * DO NOT ADD NEW FILES.
5901 name
= cfile
.file
->f_dentry
->d_name
.name
;
5903 if (!strcmp(name
, "memory.usage_in_bytes")) {
5904 event
->register_event
= mem_cgroup_usage_register_event
;
5905 event
->unregister_event
= mem_cgroup_usage_unregister_event
;
5906 } else if (!strcmp(name
, "memory.oom_control")) {
5907 event
->register_event
= mem_cgroup_oom_register_event
;
5908 event
->unregister_event
= mem_cgroup_oom_unregister_event
;
5909 } else if (!strcmp(name
, "memory.pressure_level")) {
5910 event
->register_event
= vmpressure_register_event
;
5911 event
->unregister_event
= vmpressure_unregister_event
;
5912 } else if (!strcmp(name
, "memory.memsw.usage_in_bytes")) {
5913 event
->register_event
= memsw_cgroup_usage_register_event
;
5914 event
->unregister_event
= memsw_cgroup_usage_unregister_event
;
5921 * Verify @cfile should belong to @css. Also, remaining events are
5922 * automatically removed on cgroup destruction but the removal is
5923 * asynchronous, so take an extra ref on @css.
5925 cfile_css
= css_tryget_from_dir(cfile
.file
->f_dentry
->d_parent
,
5926 &memory_cgrp_subsys
);
5928 if (IS_ERR(cfile_css
))
5930 if (cfile_css
!= css
) {
5935 ret
= event
->register_event(memcg
, event
->eventfd
, buffer
);
5939 efile
.file
->f_op
->poll(efile
.file
, &event
->pt
);
5941 spin_lock(&memcg
->event_list_lock
);
5942 list_add(&event
->list
, &memcg
->event_list
);
5943 spin_unlock(&memcg
->event_list_lock
);
5955 eventfd_ctx_put(event
->eventfd
);
5964 static struct cftype mem_cgroup_files
[] = {
5966 .name
= "usage_in_bytes",
5967 .private = MEMFILE_PRIVATE(_MEM
, RES_USAGE
),
5968 .read_u64
= mem_cgroup_read_u64
,
5971 .name
= "max_usage_in_bytes",
5972 .private = MEMFILE_PRIVATE(_MEM
, RES_MAX_USAGE
),
5973 .trigger
= mem_cgroup_reset
,
5974 .read_u64
= mem_cgroup_read_u64
,
5977 .name
= "limit_in_bytes",
5978 .private = MEMFILE_PRIVATE(_MEM
, RES_LIMIT
),
5979 .write_string
= mem_cgroup_write
,
5980 .read_u64
= mem_cgroup_read_u64
,
5983 .name
= "soft_limit_in_bytes",
5984 .private = MEMFILE_PRIVATE(_MEM
, RES_SOFT_LIMIT
),
5985 .write_string
= mem_cgroup_write
,
5986 .read_u64
= mem_cgroup_read_u64
,
5990 .private = MEMFILE_PRIVATE(_MEM
, RES_FAILCNT
),
5991 .trigger
= mem_cgroup_reset
,
5992 .read_u64
= mem_cgroup_read_u64
,
5996 .seq_show
= memcg_stat_show
,
5999 .name
= "force_empty",
6000 .trigger
= mem_cgroup_force_empty_write
,
6003 .name
= "use_hierarchy",
6004 .flags
= CFTYPE_INSANE
,
6005 .write_u64
= mem_cgroup_hierarchy_write
,
6006 .read_u64
= mem_cgroup_hierarchy_read
,
6009 .name
= "cgroup.event_control", /* XXX: for compat */
6010 .write_string
= memcg_write_event_control
,
6011 .flags
= CFTYPE_NO_PREFIX
,
6015 .name
= "swappiness",
6016 .read_u64
= mem_cgroup_swappiness_read
,
6017 .write_u64
= mem_cgroup_swappiness_write
,
6020 .name
= "move_charge_at_immigrate",
6021 .read_u64
= mem_cgroup_move_charge_read
,
6022 .write_u64
= mem_cgroup_move_charge_write
,
6025 .name
= "oom_control",
6026 .seq_show
= mem_cgroup_oom_control_read
,
6027 .write_u64
= mem_cgroup_oom_control_write
,
6028 .private = MEMFILE_PRIVATE(_OOM_TYPE
, OOM_CONTROL
),
6031 .name
= "pressure_level",
6035 .name
= "numa_stat",
6036 .seq_show
= memcg_numa_stat_show
,
6039 #ifdef CONFIG_MEMCG_KMEM
6041 .name
= "kmem.limit_in_bytes",
6042 .private = MEMFILE_PRIVATE(_KMEM
, RES_LIMIT
),
6043 .write_string
= mem_cgroup_write
,
6044 .read_u64
= mem_cgroup_read_u64
,
6047 .name
= "kmem.usage_in_bytes",
6048 .private = MEMFILE_PRIVATE(_KMEM
, RES_USAGE
),
6049 .read_u64
= mem_cgroup_read_u64
,
6052 .name
= "kmem.failcnt",
6053 .private = MEMFILE_PRIVATE(_KMEM
, RES_FAILCNT
),
6054 .trigger
= mem_cgroup_reset
,
6055 .read_u64
= mem_cgroup_read_u64
,
6058 .name
= "kmem.max_usage_in_bytes",
6059 .private = MEMFILE_PRIVATE(_KMEM
, RES_MAX_USAGE
),
6060 .trigger
= mem_cgroup_reset
,
6061 .read_u64
= mem_cgroup_read_u64
,
6063 #ifdef CONFIG_SLABINFO
6065 .name
= "kmem.slabinfo",
6066 .seq_show
= mem_cgroup_slabinfo_read
,
6070 { }, /* terminate */
6073 #ifdef CONFIG_MEMCG_SWAP
6074 static struct cftype memsw_cgroup_files
[] = {
6076 .name
= "memsw.usage_in_bytes",
6077 .private = MEMFILE_PRIVATE(_MEMSWAP
, RES_USAGE
),
6078 .read_u64
= mem_cgroup_read_u64
,
6081 .name
= "memsw.max_usage_in_bytes",
6082 .private = MEMFILE_PRIVATE(_MEMSWAP
, RES_MAX_USAGE
),
6083 .trigger
= mem_cgroup_reset
,
6084 .read_u64
= mem_cgroup_read_u64
,
6087 .name
= "memsw.limit_in_bytes",
6088 .private = MEMFILE_PRIVATE(_MEMSWAP
, RES_LIMIT
),
6089 .write_string
= mem_cgroup_write
,
6090 .read_u64
= mem_cgroup_read_u64
,
6093 .name
= "memsw.failcnt",
6094 .private = MEMFILE_PRIVATE(_MEMSWAP
, RES_FAILCNT
),
6095 .trigger
= mem_cgroup_reset
,
6096 .read_u64
= mem_cgroup_read_u64
,
6098 { }, /* terminate */
6101 static int alloc_mem_cgroup_per_zone_info(struct mem_cgroup
*memcg
, int node
)
6103 struct mem_cgroup_per_node
*pn
;
6104 struct mem_cgroup_per_zone
*mz
;
6105 int zone
, tmp
= node
;
6107 * This routine is called against possible nodes.
6108 * But it's BUG to call kmalloc() against offline node.
6110 * TODO: this routine can waste much memory for nodes which will
6111 * never be onlined. It's better to use memory hotplug callback
6114 if (!node_state(node
, N_NORMAL_MEMORY
))
6116 pn
= kzalloc_node(sizeof(*pn
), GFP_KERNEL
, tmp
);
6120 for (zone
= 0; zone
< MAX_NR_ZONES
; zone
++) {
6121 mz
= &pn
->zoneinfo
[zone
];
6122 lruvec_init(&mz
->lruvec
);
6123 mz
->usage_in_excess
= 0;
6124 mz
->on_tree
= false;
6127 memcg
->nodeinfo
[node
] = pn
;
6131 static void free_mem_cgroup_per_zone_info(struct mem_cgroup
*memcg
, int node
)
6133 kfree(memcg
->nodeinfo
[node
]);
6136 static struct mem_cgroup
*mem_cgroup_alloc(void)
6138 struct mem_cgroup
*memcg
;
6141 size
= sizeof(struct mem_cgroup
);
6142 size
+= nr_node_ids
* sizeof(struct mem_cgroup_per_node
*);
6144 memcg
= kzalloc(size
, GFP_KERNEL
);
6148 memcg
->stat
= alloc_percpu(struct mem_cgroup_stat_cpu
);
6151 spin_lock_init(&memcg
->pcp_counter_lock
);
6160 * At destroying mem_cgroup, references from swap_cgroup can remain.
6161 * (scanning all at force_empty is too costly...)
6163 * Instead of clearing all references at force_empty, we remember
6164 * the number of reference from swap_cgroup and free mem_cgroup when
6165 * it goes down to 0.
6167 * Removal of cgroup itself succeeds regardless of refs from swap.
6170 static void __mem_cgroup_free(struct mem_cgroup
*memcg
)
6174 mem_cgroup_remove_from_trees(memcg
);
6177 free_mem_cgroup_per_zone_info(memcg
, node
);
6179 free_percpu(memcg
->stat
);
6182 * We need to make sure that (at least for now), the jump label
6183 * destruction code runs outside of the cgroup lock. This is because
6184 * get_online_cpus(), which is called from the static_branch update,
6185 * can't be called inside the cgroup_lock. cpusets are the ones
6186 * enforcing this dependency, so if they ever change, we might as well.
6188 * schedule_work() will guarantee this happens. Be careful if you need
6189 * to move this code around, and make sure it is outside
6192 disarm_static_keys(memcg
);
6197 * Returns the parent mem_cgroup in memcgroup hierarchy with hierarchy enabled.
6199 struct mem_cgroup
*parent_mem_cgroup(struct mem_cgroup
*memcg
)
6201 if (!memcg
->res
.parent
)
6203 return mem_cgroup_from_res_counter(memcg
->res
.parent
, res
);
6205 EXPORT_SYMBOL(parent_mem_cgroup
);
6207 static void __init
mem_cgroup_soft_limit_tree_init(void)
6209 struct mem_cgroup_tree_per_node
*rtpn
;
6210 struct mem_cgroup_tree_per_zone
*rtpz
;
6211 int tmp
, node
, zone
;
6213 for_each_node(node
) {
6215 if (!node_state(node
, N_NORMAL_MEMORY
))
6217 rtpn
= kzalloc_node(sizeof(*rtpn
), GFP_KERNEL
, tmp
);
6220 soft_limit_tree
.rb_tree_per_node
[node
] = rtpn
;
6222 for (zone
= 0; zone
< MAX_NR_ZONES
; zone
++) {
6223 rtpz
= &rtpn
->rb_tree_per_zone
[zone
];
6224 rtpz
->rb_root
= RB_ROOT
;
6225 spin_lock_init(&rtpz
->lock
);
6230 static struct cgroup_subsys_state
* __ref
6231 mem_cgroup_css_alloc(struct cgroup_subsys_state
*parent_css
)
6233 struct mem_cgroup
*memcg
;
6234 long error
= -ENOMEM
;
6237 memcg
= mem_cgroup_alloc();
6239 return ERR_PTR(error
);
6242 if (alloc_mem_cgroup_per_zone_info(memcg
, node
))
6246 if (parent_css
== NULL
) {
6247 root_mem_cgroup
= memcg
;
6248 res_counter_init(&memcg
->res
, NULL
);
6249 res_counter_init(&memcg
->memsw
, NULL
);
6250 res_counter_init(&memcg
->kmem
, NULL
);
6253 memcg
->last_scanned_node
= MAX_NUMNODES
;
6254 INIT_LIST_HEAD(&memcg
->oom_notify
);
6255 memcg
->move_charge_at_immigrate
= 0;
6256 mutex_init(&memcg
->thresholds_lock
);
6257 spin_lock_init(&memcg
->move_lock
);
6258 vmpressure_init(&memcg
->vmpressure
);
6259 INIT_LIST_HEAD(&memcg
->event_list
);
6260 spin_lock_init(&memcg
->event_list_lock
);
6265 __mem_cgroup_free(memcg
);
6266 return ERR_PTR(error
);
6270 mem_cgroup_css_online(struct cgroup_subsys_state
*css
)
6272 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
6273 struct mem_cgroup
*parent
= mem_cgroup_from_css(css_parent(css
));
6275 if (css
->cgroup
->id
> MEM_CGROUP_ID_MAX
)
6281 mutex_lock(&memcg_create_mutex
);
6283 memcg
->use_hierarchy
= parent
->use_hierarchy
;
6284 memcg
->oom_kill_disable
= parent
->oom_kill_disable
;
6285 memcg
->swappiness
= mem_cgroup_swappiness(parent
);
6287 if (parent
->use_hierarchy
) {
6288 res_counter_init(&memcg
->res
, &parent
->res
);
6289 res_counter_init(&memcg
->memsw
, &parent
->memsw
);
6290 res_counter_init(&memcg
->kmem
, &parent
->kmem
);
6293 * No need to take a reference to the parent because cgroup
6294 * core guarantees its existence.
6297 res_counter_init(&memcg
->res
, NULL
);
6298 res_counter_init(&memcg
->memsw
, NULL
);
6299 res_counter_init(&memcg
->kmem
, NULL
);
6301 * Deeper hierachy with use_hierarchy == false doesn't make
6302 * much sense so let cgroup subsystem know about this
6303 * unfortunate state in our controller.
6305 if (parent
!= root_mem_cgroup
)
6306 memory_cgrp_subsys
.broken_hierarchy
= true;
6308 mutex_unlock(&memcg_create_mutex
);
6310 return memcg_init_kmem(memcg
, &memory_cgrp_subsys
);
6314 * Announce all parents that a group from their hierarchy is gone.
6316 static void mem_cgroup_invalidate_reclaim_iterators(struct mem_cgroup
*memcg
)
6318 struct mem_cgroup
*parent
= memcg
;
6320 while ((parent
= parent_mem_cgroup(parent
)))
6321 mem_cgroup_iter_invalidate(parent
);
6324 * if the root memcg is not hierarchical we have to check it
6327 if (!root_mem_cgroup
->use_hierarchy
)
6328 mem_cgroup_iter_invalidate(root_mem_cgroup
);
6331 static void mem_cgroup_css_offline(struct cgroup_subsys_state
*css
)
6333 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
6334 struct mem_cgroup_event
*event
, *tmp
;
6335 struct cgroup_subsys_state
*iter
;
6338 * Unregister events and notify userspace.
6339 * Notify userspace about cgroup removing only after rmdir of cgroup
6340 * directory to avoid race between userspace and kernelspace.
6342 spin_lock(&memcg
->event_list_lock
);
6343 list_for_each_entry_safe(event
, tmp
, &memcg
->event_list
, list
) {
6344 list_del_init(&event
->list
);
6345 schedule_work(&event
->remove
);
6347 spin_unlock(&memcg
->event_list_lock
);
6349 kmem_cgroup_css_offline(memcg
);
6351 mem_cgroup_invalidate_reclaim_iterators(memcg
);
6354 * This requires that offlining is serialized. Right now that is
6355 * guaranteed because css_killed_work_fn() holds the cgroup_mutex.
6357 css_for_each_descendant_post(iter
, css
)
6358 mem_cgroup_reparent_charges(mem_cgroup_from_css(iter
));
6360 memcg_unregister_all_caches(memcg
);
6361 vmpressure_cleanup(&memcg
->vmpressure
);
6364 static void mem_cgroup_css_free(struct cgroup_subsys_state
*css
)
6366 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
6368 * XXX: css_offline() would be where we should reparent all
6369 * memory to prepare the cgroup for destruction. However,
6370 * memcg does not do css_tryget() and res_counter charging
6371 * under the same RCU lock region, which means that charging
6372 * could race with offlining. Offlining only happens to
6373 * cgroups with no tasks in them but charges can show up
6374 * without any tasks from the swapin path when the target
6375 * memcg is looked up from the swapout record and not from the
6376 * current task as it usually is. A race like this can leak
6377 * charges and put pages with stale cgroup pointers into
6381 * lookup_swap_cgroup_id()
6383 * mem_cgroup_lookup()
6386 * disable css_tryget()
6389 * reparent_charges()
6390 * res_counter_charge()
6393 * pc->mem_cgroup = dead memcg
6396 * The bulk of the charges are still moved in offline_css() to
6397 * avoid pinning a lot of pages in case a long-term reference
6398 * like a swapout record is deferring the css_free() to long
6399 * after offlining. But this makes sure we catch any charges
6400 * made after offlining:
6402 mem_cgroup_reparent_charges(memcg
);
6404 memcg_destroy_kmem(memcg
);
6405 __mem_cgroup_free(memcg
);
6409 /* Handlers for move charge at task migration. */
6410 #define PRECHARGE_COUNT_AT_ONCE 256
6411 static int mem_cgroup_do_precharge(unsigned long count
)
6414 int batch_count
= PRECHARGE_COUNT_AT_ONCE
;
6415 struct mem_cgroup
*memcg
= mc
.to
;
6417 if (mem_cgroup_is_root(memcg
)) {
6418 mc
.precharge
+= count
;
6419 /* we don't need css_get for root */
6422 /* try to charge at once */
6424 struct res_counter
*dummy
;
6426 * "memcg" cannot be under rmdir() because we've already checked
6427 * by cgroup_lock_live_cgroup() that it is not removed and we
6428 * are still under the same cgroup_mutex. So we can postpone
6431 if (res_counter_charge(&memcg
->res
, PAGE_SIZE
* count
, &dummy
))
6433 if (do_swap_account
&& res_counter_charge(&memcg
->memsw
,
6434 PAGE_SIZE
* count
, &dummy
)) {
6435 res_counter_uncharge(&memcg
->res
, PAGE_SIZE
* count
);
6438 mc
.precharge
+= count
;
6442 /* fall back to one by one charge */
6444 if (signal_pending(current
)) {
6448 if (!batch_count
--) {
6449 batch_count
= PRECHARGE_COUNT_AT_ONCE
;
6452 ret
= mem_cgroup_try_charge(memcg
, GFP_KERNEL
, 1, false);
6454 /* mem_cgroup_clear_mc() will do uncharge later */
6462 * get_mctgt_type - get target type of moving charge
6463 * @vma: the vma the pte to be checked belongs
6464 * @addr: the address corresponding to the pte to be checked
6465 * @ptent: the pte to be checked
6466 * @target: the pointer the target page or swap ent will be stored(can be NULL)
6469 * 0(MC_TARGET_NONE): if the pte is not a target for move charge.
6470 * 1(MC_TARGET_PAGE): if the page corresponding to this pte is a target for
6471 * move charge. if @target is not NULL, the page is stored in target->page
6472 * with extra refcnt got(Callers should handle it).
6473 * 2(MC_TARGET_SWAP): if the swap entry corresponding to this pte is a
6474 * target for charge migration. if @target is not NULL, the entry is stored
6477 * Called with pte lock held.
6484 enum mc_target_type
{
6490 static struct page
*mc_handle_present_pte(struct vm_area_struct
*vma
,
6491 unsigned long addr
, pte_t ptent
)
6493 struct page
*page
= vm_normal_page(vma
, addr
, ptent
);
6495 if (!page
|| !page_mapped(page
))
6497 if (PageAnon(page
)) {
6498 /* we don't move shared anon */
6501 } else if (!move_file())
6502 /* we ignore mapcount for file pages */
6504 if (!get_page_unless_zero(page
))
6511 static struct page
*mc_handle_swap_pte(struct vm_area_struct
*vma
,
6512 unsigned long addr
, pte_t ptent
, swp_entry_t
*entry
)
6514 struct page
*page
= NULL
;
6515 swp_entry_t ent
= pte_to_swp_entry(ptent
);
6517 if (!move_anon() || non_swap_entry(ent
))
6520 * Because lookup_swap_cache() updates some statistics counter,
6521 * we call find_get_page() with swapper_space directly.
6523 page
= find_get_page(swap_address_space(ent
), ent
.val
);
6524 if (do_swap_account
)
6525 entry
->val
= ent
.val
;
6530 static struct page
*mc_handle_swap_pte(struct vm_area_struct
*vma
,
6531 unsigned long addr
, pte_t ptent
, swp_entry_t
*entry
)
6537 static struct page
*mc_handle_file_pte(struct vm_area_struct
*vma
,
6538 unsigned long addr
, pte_t ptent
, swp_entry_t
*entry
)
6540 struct page
*page
= NULL
;
6541 struct address_space
*mapping
;
6544 if (!vma
->vm_file
) /* anonymous vma */
6549 mapping
= vma
->vm_file
->f_mapping
;
6550 if (pte_none(ptent
))
6551 pgoff
= linear_page_index(vma
, addr
);
6552 else /* pte_file(ptent) is true */
6553 pgoff
= pte_to_pgoff(ptent
);
6555 /* page is moved even if it's not RSS of this task(page-faulted). */
6557 /* shmem/tmpfs may report page out on swap: account for that too. */
6558 if (shmem_mapping(mapping
)) {
6559 page
= find_get_entry(mapping
, pgoff
);
6560 if (radix_tree_exceptional_entry(page
)) {
6561 swp_entry_t swp
= radix_to_swp_entry(page
);
6562 if (do_swap_account
)
6564 page
= find_get_page(swap_address_space(swp
), swp
.val
);
6567 page
= find_get_page(mapping
, pgoff
);
6569 page
= find_get_page(mapping
, pgoff
);
6574 static enum mc_target_type
get_mctgt_type(struct vm_area_struct
*vma
,
6575 unsigned long addr
, pte_t ptent
, union mc_target
*target
)
6577 struct page
*page
= NULL
;
6578 struct page_cgroup
*pc
;
6579 enum mc_target_type ret
= MC_TARGET_NONE
;
6580 swp_entry_t ent
= { .val
= 0 };
6582 if (pte_present(ptent
))
6583 page
= mc_handle_present_pte(vma
, addr
, ptent
);
6584 else if (is_swap_pte(ptent
))
6585 page
= mc_handle_swap_pte(vma
, addr
, ptent
, &ent
);
6586 else if (pte_none(ptent
) || pte_file(ptent
))
6587 page
= mc_handle_file_pte(vma
, addr
, ptent
, &ent
);
6589 if (!page
&& !ent
.val
)
6592 pc
= lookup_page_cgroup(page
);
6594 * Do only loose check w/o page_cgroup lock.
6595 * mem_cgroup_move_account() checks the pc is valid or not under
6598 if (PageCgroupUsed(pc
) && pc
->mem_cgroup
== mc
.from
) {
6599 ret
= MC_TARGET_PAGE
;
6601 target
->page
= page
;
6603 if (!ret
|| !target
)
6606 /* There is a swap entry and a page doesn't exist or isn't charged */
6607 if (ent
.val
&& !ret
&&
6608 mem_cgroup_id(mc
.from
) == lookup_swap_cgroup_id(ent
)) {
6609 ret
= MC_TARGET_SWAP
;
6616 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
6618 * We don't consider swapping or file mapped pages because THP does not
6619 * support them for now.
6620 * Caller should make sure that pmd_trans_huge(pmd) is true.
6622 static enum mc_target_type
get_mctgt_type_thp(struct vm_area_struct
*vma
,
6623 unsigned long addr
, pmd_t pmd
, union mc_target
*target
)
6625 struct page
*page
= NULL
;
6626 struct page_cgroup
*pc
;
6627 enum mc_target_type ret
= MC_TARGET_NONE
;
6629 page
= pmd_page(pmd
);
6630 VM_BUG_ON_PAGE(!page
|| !PageHead(page
), page
);
6633 pc
= lookup_page_cgroup(page
);
6634 if (PageCgroupUsed(pc
) && pc
->mem_cgroup
== mc
.from
) {
6635 ret
= MC_TARGET_PAGE
;
6638 target
->page
= page
;
6644 static inline enum mc_target_type
get_mctgt_type_thp(struct vm_area_struct
*vma
,
6645 unsigned long addr
, pmd_t pmd
, union mc_target
*target
)
6647 return MC_TARGET_NONE
;
6651 static int mem_cgroup_count_precharge_pte_range(pmd_t
*pmd
,
6652 unsigned long addr
, unsigned long end
,
6653 struct mm_walk
*walk
)
6655 struct vm_area_struct
*vma
= walk
->private;
6659 if (pmd_trans_huge_lock(pmd
, vma
, &ptl
) == 1) {
6660 if (get_mctgt_type_thp(vma
, addr
, *pmd
, NULL
) == MC_TARGET_PAGE
)
6661 mc
.precharge
+= HPAGE_PMD_NR
;
6666 if (pmd_trans_unstable(pmd
))
6668 pte
= pte_offset_map_lock(vma
->vm_mm
, pmd
, addr
, &ptl
);
6669 for (; addr
!= end
; pte
++, addr
+= PAGE_SIZE
)
6670 if (get_mctgt_type(vma
, addr
, *pte
, NULL
))
6671 mc
.precharge
++; /* increment precharge temporarily */
6672 pte_unmap_unlock(pte
- 1, ptl
);
6678 static unsigned long mem_cgroup_count_precharge(struct mm_struct
*mm
)
6680 unsigned long precharge
;
6681 struct vm_area_struct
*vma
;
6683 down_read(&mm
->mmap_sem
);
6684 for (vma
= mm
->mmap
; vma
; vma
= vma
->vm_next
) {
6685 struct mm_walk mem_cgroup_count_precharge_walk
= {
6686 .pmd_entry
= mem_cgroup_count_precharge_pte_range
,
6690 if (is_vm_hugetlb_page(vma
))
6692 walk_page_range(vma
->vm_start
, vma
->vm_end
,
6693 &mem_cgroup_count_precharge_walk
);
6695 up_read(&mm
->mmap_sem
);
6697 precharge
= mc
.precharge
;
6703 static int mem_cgroup_precharge_mc(struct mm_struct
*mm
)
6705 unsigned long precharge
= mem_cgroup_count_precharge(mm
);
6707 VM_BUG_ON(mc
.moving_task
);
6708 mc
.moving_task
= current
;
6709 return mem_cgroup_do_precharge(precharge
);
6712 /* cancels all extra charges on mc.from and mc.to, and wakes up all waiters. */
6713 static void __mem_cgroup_clear_mc(void)
6715 struct mem_cgroup
*from
= mc
.from
;
6716 struct mem_cgroup
*to
= mc
.to
;
6719 /* we must uncharge all the leftover precharges from mc.to */
6721 __mem_cgroup_cancel_charge(mc
.to
, mc
.precharge
);
6725 * we didn't uncharge from mc.from at mem_cgroup_move_account(), so
6726 * we must uncharge here.
6728 if (mc
.moved_charge
) {
6729 __mem_cgroup_cancel_charge(mc
.from
, mc
.moved_charge
);
6730 mc
.moved_charge
= 0;
6732 /* we must fixup refcnts and charges */
6733 if (mc
.moved_swap
) {
6734 /* uncharge swap account from the old cgroup */
6735 if (!mem_cgroup_is_root(mc
.from
))
6736 res_counter_uncharge(&mc
.from
->memsw
,
6737 PAGE_SIZE
* mc
.moved_swap
);
6739 for (i
= 0; i
< mc
.moved_swap
; i
++)
6740 css_put(&mc
.from
->css
);
6742 if (!mem_cgroup_is_root(mc
.to
)) {
6744 * we charged both to->res and to->memsw, so we should
6747 res_counter_uncharge(&mc
.to
->res
,
6748 PAGE_SIZE
* mc
.moved_swap
);
6750 /* we've already done css_get(mc.to) */
6753 memcg_oom_recover(from
);
6754 memcg_oom_recover(to
);
6755 wake_up_all(&mc
.waitq
);
6758 static void mem_cgroup_clear_mc(void)
6760 struct mem_cgroup
*from
= mc
.from
;
6763 * we must clear moving_task before waking up waiters at the end of
6766 mc
.moving_task
= NULL
;
6767 __mem_cgroup_clear_mc();
6768 spin_lock(&mc
.lock
);
6771 spin_unlock(&mc
.lock
);
6772 mem_cgroup_end_move(from
);
6775 static int mem_cgroup_can_attach(struct cgroup_subsys_state
*css
,
6776 struct cgroup_taskset
*tset
)
6778 struct task_struct
*p
= cgroup_taskset_first(tset
);
6780 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
6781 unsigned long move_charge_at_immigrate
;
6784 * We are now commited to this value whatever it is. Changes in this
6785 * tunable will only affect upcoming migrations, not the current one.
6786 * So we need to save it, and keep it going.
6788 move_charge_at_immigrate
= memcg
->move_charge_at_immigrate
;
6789 if (move_charge_at_immigrate
) {
6790 struct mm_struct
*mm
;
6791 struct mem_cgroup
*from
= mem_cgroup_from_task(p
);
6793 VM_BUG_ON(from
== memcg
);
6795 mm
= get_task_mm(p
);
6798 /* We move charges only when we move a owner of the mm */
6799 if (mm
->owner
== p
) {
6802 VM_BUG_ON(mc
.precharge
);
6803 VM_BUG_ON(mc
.moved_charge
);
6804 VM_BUG_ON(mc
.moved_swap
);
6805 mem_cgroup_start_move(from
);
6806 spin_lock(&mc
.lock
);
6809 mc
.immigrate_flags
= move_charge_at_immigrate
;
6810 spin_unlock(&mc
.lock
);
6811 /* We set mc.moving_task later */
6813 ret
= mem_cgroup_precharge_mc(mm
);
6815 mem_cgroup_clear_mc();
6822 static void mem_cgroup_cancel_attach(struct cgroup_subsys_state
*css
,
6823 struct cgroup_taskset
*tset
)
6825 mem_cgroup_clear_mc();
6828 static int mem_cgroup_move_charge_pte_range(pmd_t
*pmd
,
6829 unsigned long addr
, unsigned long end
,
6830 struct mm_walk
*walk
)
6833 struct vm_area_struct
*vma
= walk
->private;
6836 enum mc_target_type target_type
;
6837 union mc_target target
;
6839 struct page_cgroup
*pc
;
6842 * We don't take compound_lock() here but no race with splitting thp
6844 * - if pmd_trans_huge_lock() returns 1, the relevant thp is not
6845 * under splitting, which means there's no concurrent thp split,
6846 * - if another thread runs into split_huge_page() just after we
6847 * entered this if-block, the thread must wait for page table lock
6848 * to be unlocked in __split_huge_page_splitting(), where the main
6849 * part of thp split is not executed yet.
6851 if (pmd_trans_huge_lock(pmd
, vma
, &ptl
) == 1) {
6852 if (mc
.precharge
< HPAGE_PMD_NR
) {
6856 target_type
= get_mctgt_type_thp(vma
, addr
, *pmd
, &target
);
6857 if (target_type
== MC_TARGET_PAGE
) {
6859 if (!isolate_lru_page(page
)) {
6860 pc
= lookup_page_cgroup(page
);
6861 if (!mem_cgroup_move_account(page
, HPAGE_PMD_NR
,
6862 pc
, mc
.from
, mc
.to
)) {
6863 mc
.precharge
-= HPAGE_PMD_NR
;
6864 mc
.moved_charge
+= HPAGE_PMD_NR
;
6866 putback_lru_page(page
);
6874 if (pmd_trans_unstable(pmd
))
6877 pte
= pte_offset_map_lock(vma
->vm_mm
, pmd
, addr
, &ptl
);
6878 for (; addr
!= end
; addr
+= PAGE_SIZE
) {
6879 pte_t ptent
= *(pte
++);
6885 switch (get_mctgt_type(vma
, addr
, ptent
, &target
)) {
6886 case MC_TARGET_PAGE
:
6888 if (isolate_lru_page(page
))
6890 pc
= lookup_page_cgroup(page
);
6891 if (!mem_cgroup_move_account(page
, 1, pc
,
6894 /* we uncharge from mc.from later. */
6897 putback_lru_page(page
);
6898 put
: /* get_mctgt_type() gets the page */
6901 case MC_TARGET_SWAP
:
6903 if (!mem_cgroup_move_swap_account(ent
, mc
.from
, mc
.to
)) {
6905 /* we fixup refcnts and charges later. */
6913 pte_unmap_unlock(pte
- 1, ptl
);
6918 * We have consumed all precharges we got in can_attach().
6919 * We try charge one by one, but don't do any additional
6920 * charges to mc.to if we have failed in charge once in attach()
6923 ret
= mem_cgroup_do_precharge(1);
6931 static void mem_cgroup_move_charge(struct mm_struct
*mm
)
6933 struct vm_area_struct
*vma
;
6935 lru_add_drain_all();
6937 if (unlikely(!down_read_trylock(&mm
->mmap_sem
))) {
6939 * Someone who are holding the mmap_sem might be waiting in
6940 * waitq. So we cancel all extra charges, wake up all waiters,
6941 * and retry. Because we cancel precharges, we might not be able
6942 * to move enough charges, but moving charge is a best-effort
6943 * feature anyway, so it wouldn't be a big problem.
6945 __mem_cgroup_clear_mc();
6949 for (vma
= mm
->mmap
; vma
; vma
= vma
->vm_next
) {
6951 struct mm_walk mem_cgroup_move_charge_walk
= {
6952 .pmd_entry
= mem_cgroup_move_charge_pte_range
,
6956 if (is_vm_hugetlb_page(vma
))
6958 ret
= walk_page_range(vma
->vm_start
, vma
->vm_end
,
6959 &mem_cgroup_move_charge_walk
);
6962 * means we have consumed all precharges and failed in
6963 * doing additional charge. Just abandon here.
6967 up_read(&mm
->mmap_sem
);
6970 static void mem_cgroup_move_task(struct cgroup_subsys_state
*css
,
6971 struct cgroup_taskset
*tset
)
6973 struct task_struct
*p
= cgroup_taskset_first(tset
);
6974 struct mm_struct
*mm
= get_task_mm(p
);
6978 mem_cgroup_move_charge(mm
);
6982 mem_cgroup_clear_mc();
6984 #else /* !CONFIG_MMU */
6985 static int mem_cgroup_can_attach(struct cgroup_subsys_state
*css
,
6986 struct cgroup_taskset
*tset
)
6990 static void mem_cgroup_cancel_attach(struct cgroup_subsys_state
*css
,
6991 struct cgroup_taskset
*tset
)
6994 static void mem_cgroup_move_task(struct cgroup_subsys_state
*css
,
6995 struct cgroup_taskset
*tset
)
7001 * Cgroup retains root cgroups across [un]mount cycles making it necessary
7002 * to verify sane_behavior flag on each mount attempt.
7004 static void mem_cgroup_bind(struct cgroup_subsys_state
*root_css
)
7007 * use_hierarchy is forced with sane_behavior. cgroup core
7008 * guarantees that @root doesn't have any children, so turning it
7009 * on for the root memcg is enough.
7011 if (cgroup_sane_behavior(root_css
->cgroup
))
7012 mem_cgroup_from_css(root_css
)->use_hierarchy
= true;
7015 struct cgroup_subsys memory_cgrp_subsys
= {
7016 .css_alloc
= mem_cgroup_css_alloc
,
7017 .css_online
= mem_cgroup_css_online
,
7018 .css_offline
= mem_cgroup_css_offline
,
7019 .css_free
= mem_cgroup_css_free
,
7020 .can_attach
= mem_cgroup_can_attach
,
7021 .cancel_attach
= mem_cgroup_cancel_attach
,
7022 .attach
= mem_cgroup_move_task
,
7023 .bind
= mem_cgroup_bind
,
7024 .base_cftypes
= mem_cgroup_files
,
7028 #ifdef CONFIG_MEMCG_SWAP
7029 static int __init
enable_swap_account(char *s
)
7031 if (!strcmp(s
, "1"))
7032 really_do_swap_account
= 1;
7033 else if (!strcmp(s
, "0"))
7034 really_do_swap_account
= 0;
7037 __setup("swapaccount=", enable_swap_account
);
7039 static void __init
memsw_file_init(void)
7041 WARN_ON(cgroup_add_cftypes(&memory_cgrp_subsys
, memsw_cgroup_files
));
7044 static void __init
enable_swap_cgroup(void)
7046 if (!mem_cgroup_disabled() && really_do_swap_account
) {
7047 do_swap_account
= 1;
7053 static void __init
enable_swap_cgroup(void)
7059 * subsys_initcall() for memory controller.
7061 * Some parts like hotcpu_notifier() have to be initialized from this context
7062 * because of lock dependencies (cgroup_lock -> cpu hotplug) but basically
7063 * everything that doesn't depend on a specific mem_cgroup structure should
7064 * be initialized from here.
7066 static int __init
mem_cgroup_init(void)
7068 hotcpu_notifier(memcg_cpu_hotplug_callback
, 0);
7069 enable_swap_cgroup();
7070 mem_cgroup_soft_limit_tree_init();
7074 subsys_initcall(mem_cgroup_init
);