1 /* memcontrol.c - Memory Controller
3 * Copyright IBM Corporation, 2007
4 * Author Balbir Singh <balbir@linux.vnet.ibm.com>
6 * Copyright 2007 OpenVZ SWsoft Inc
7 * Author: Pavel Emelianov <xemul@openvz.org>
10 * Copyright (C) 2009 Nokia Corporation
11 * Author: Kirill A. Shutemov
13 * Kernel Memory Controller
14 * Copyright (C) 2012 Parallels Inc. and Google Inc.
15 * Authors: Glauber Costa and Suleiman Souhlal
17 * This program is free software; you can redistribute it and/or modify
18 * it under the terms of the GNU General Public License as published by
19 * the Free Software Foundation; either version 2 of the License, or
20 * (at your option) any later version.
22 * This program is distributed in the hope that it will be useful,
23 * but WITHOUT ANY WARRANTY; without even the implied warranty of
24 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
25 * GNU General Public License for more details.
28 #include <linux/res_counter.h>
29 #include <linux/memcontrol.h>
30 #include <linux/cgroup.h>
32 #include <linux/hugetlb.h>
33 #include <linux/pagemap.h>
34 #include <linux/smp.h>
35 #include <linux/page-flags.h>
36 #include <linux/backing-dev.h>
37 #include <linux/bit_spinlock.h>
38 #include <linux/rcupdate.h>
39 #include <linux/limits.h>
40 #include <linux/export.h>
41 #include <linux/mutex.h>
42 #include <linux/rbtree.h>
43 #include <linux/slab.h>
44 #include <linux/swap.h>
45 #include <linux/swapops.h>
46 #include <linux/spinlock.h>
47 #include <linux/eventfd.h>
48 #include <linux/sort.h>
50 #include <linux/seq_file.h>
51 #include <linux/vmalloc.h>
52 #include <linux/vmpressure.h>
53 #include <linux/mm_inline.h>
54 #include <linux/page_cgroup.h>
55 #include <linux/cpu.h>
56 #include <linux/oom.h>
60 #include <net/tcp_memcontrol.h>
62 #include <asm/uaccess.h>
64 #include <trace/events/vmscan.h>
66 struct cgroup_subsys mem_cgroup_subsys __read_mostly
;
67 EXPORT_SYMBOL(mem_cgroup_subsys
);
69 #define MEM_CGROUP_RECLAIM_RETRIES 5
70 static struct mem_cgroup
*root_mem_cgroup __read_mostly
;
72 #ifdef CONFIG_MEMCG_SWAP
73 /* Turned on only when memory cgroup is enabled && really_do_swap_account = 1 */
74 int do_swap_account __read_mostly
;
76 /* for remember boot option*/
77 #ifdef CONFIG_MEMCG_SWAP_ENABLED
78 static int really_do_swap_account __initdata
= 1;
80 static int really_do_swap_account __initdata
= 0;
84 #define do_swap_account 0
89 * Statistics for memory cgroup.
91 enum mem_cgroup_stat_index
{
93 * For MEM_CONTAINER_TYPE_ALL, usage = pagecache + rss.
95 MEM_CGROUP_STAT_CACHE
, /* # of pages charged as cache */
96 MEM_CGROUP_STAT_RSS
, /* # of pages charged as anon rss */
97 MEM_CGROUP_STAT_RSS_HUGE
, /* # of pages charged as anon huge */
98 MEM_CGROUP_STAT_FILE_MAPPED
, /* # of pages charged as file rss */
99 MEM_CGROUP_STAT_SWAP
, /* # of pages, swapped out */
100 MEM_CGROUP_STAT_NSTATS
,
103 static const char * const mem_cgroup_stat_names
[] = {
111 enum mem_cgroup_events_index
{
112 MEM_CGROUP_EVENTS_PGPGIN
, /* # of pages paged in */
113 MEM_CGROUP_EVENTS_PGPGOUT
, /* # of pages paged out */
114 MEM_CGROUP_EVENTS_PGFAULT
, /* # of page-faults */
115 MEM_CGROUP_EVENTS_PGMAJFAULT
, /* # of major page-faults */
116 MEM_CGROUP_EVENTS_NSTATS
,
119 static const char * const mem_cgroup_events_names
[] = {
126 static const char * const mem_cgroup_lru_names
[] = {
135 * Per memcg event counter is incremented at every pagein/pageout. With THP,
136 * it will be incremated by the number of pages. This counter is used for
137 * for trigger some periodic events. This is straightforward and better
138 * than using jiffies etc. to handle periodic memcg event.
140 enum mem_cgroup_events_target
{
141 MEM_CGROUP_TARGET_THRESH
,
142 MEM_CGROUP_TARGET_SOFTLIMIT
,
143 MEM_CGROUP_TARGET_NUMAINFO
,
146 #define THRESHOLDS_EVENTS_TARGET 128
147 #define SOFTLIMIT_EVENTS_TARGET 1024
148 #define NUMAINFO_EVENTS_TARGET 1024
150 struct mem_cgroup_stat_cpu
{
151 long count
[MEM_CGROUP_STAT_NSTATS
];
152 unsigned long events
[MEM_CGROUP_EVENTS_NSTATS
];
153 unsigned long nr_page_events
;
154 unsigned long targets
[MEM_CGROUP_NTARGETS
];
157 struct mem_cgroup_reclaim_iter
{
159 * last scanned hierarchy member. Valid only if last_dead_count
160 * matches memcg->dead_count of the hierarchy root group.
162 struct mem_cgroup
*last_visited
;
163 unsigned long last_dead_count
;
165 /* scan generation, increased every round-trip */
166 unsigned int generation
;
170 * per-zone information in memory controller.
172 struct mem_cgroup_per_zone
{
173 struct lruvec lruvec
;
174 unsigned long lru_size
[NR_LRU_LISTS
];
176 struct mem_cgroup_reclaim_iter reclaim_iter
[DEF_PRIORITY
+ 1];
178 struct rb_node tree_node
; /* RB tree node */
179 unsigned long long usage_in_excess
;/* Set to the value by which */
180 /* the soft limit is exceeded*/
182 struct mem_cgroup
*memcg
; /* Back pointer, we cannot */
183 /* use container_of */
186 struct mem_cgroup_per_node
{
187 struct mem_cgroup_per_zone zoneinfo
[MAX_NR_ZONES
];
190 struct mem_cgroup_lru_info
{
191 struct mem_cgroup_per_node
*nodeinfo
[0];
195 * Cgroups above their limits are maintained in a RB-Tree, independent of
196 * their hierarchy representation
199 struct mem_cgroup_tree_per_zone
{
200 struct rb_root rb_root
;
204 struct mem_cgroup_tree_per_node
{
205 struct mem_cgroup_tree_per_zone rb_tree_per_zone
[MAX_NR_ZONES
];
208 struct mem_cgroup_tree
{
209 struct mem_cgroup_tree_per_node
*rb_tree_per_node
[MAX_NUMNODES
];
212 static struct mem_cgroup_tree soft_limit_tree __read_mostly
;
214 struct mem_cgroup_threshold
{
215 struct eventfd_ctx
*eventfd
;
220 struct mem_cgroup_threshold_ary
{
221 /* An array index points to threshold just below or equal to usage. */
222 int current_threshold
;
223 /* Size of entries[] */
225 /* Array of thresholds */
226 struct mem_cgroup_threshold entries
[0];
229 struct mem_cgroup_thresholds
{
230 /* Primary thresholds array */
231 struct mem_cgroup_threshold_ary
*primary
;
233 * Spare threshold array.
234 * This is needed to make mem_cgroup_unregister_event() "never fail".
235 * It must be able to store at least primary->size - 1 entries.
237 struct mem_cgroup_threshold_ary
*spare
;
241 struct mem_cgroup_eventfd_list
{
242 struct list_head list
;
243 struct eventfd_ctx
*eventfd
;
246 static void mem_cgroup_threshold(struct mem_cgroup
*memcg
);
247 static void mem_cgroup_oom_notify(struct mem_cgroup
*memcg
);
250 * The memory controller data structure. The memory controller controls both
251 * page cache and RSS per cgroup. We would eventually like to provide
252 * statistics based on the statistics developed by Rik Van Riel for clock-pro,
253 * to help the administrator determine what knobs to tune.
255 * TODO: Add a water mark for the memory controller. Reclaim will begin when
256 * we hit the water mark. May be even add a low water mark, such that
257 * no reclaim occurs from a cgroup at it's low water mark, this is
258 * a feature that will be implemented much later in the future.
261 struct cgroup_subsys_state css
;
263 * the counter to account for memory usage
265 struct res_counter res
;
267 /* vmpressure notifications */
268 struct vmpressure vmpressure
;
272 * the counter to account for mem+swap usage.
274 struct res_counter memsw
;
277 * rcu_freeing is used only when freeing struct mem_cgroup,
278 * so put it into a union to avoid wasting more memory.
279 * It must be disjoint from the css field. It could be
280 * in a union with the res field, but res plays a much
281 * larger part in mem_cgroup life than memsw, and might
282 * be of interest, even at time of free, when debugging.
283 * So share rcu_head with the less interesting memsw.
285 struct rcu_head rcu_freeing
;
287 * We also need some space for a worker in deferred freeing.
288 * By the time we call it, rcu_freeing is no longer in use.
290 struct work_struct work_freeing
;
294 * the counter to account for kernel memory usage.
296 struct res_counter kmem
;
298 * Should the accounting and control be hierarchical, per subtree?
301 unsigned long kmem_account_flags
; /* See KMEM_ACCOUNTED_*, below */
309 /* OOM-Killer disable */
310 int oom_kill_disable
;
312 /* set when res.limit == memsw.limit */
313 bool memsw_is_minimum
;
315 /* protect arrays of thresholds */
316 struct mutex thresholds_lock
;
318 /* thresholds for memory usage. RCU-protected */
319 struct mem_cgroup_thresholds thresholds
;
321 /* thresholds for mem+swap usage. RCU-protected */
322 struct mem_cgroup_thresholds memsw_thresholds
;
324 /* For oom notifier event fd */
325 struct list_head oom_notify
;
328 * Should we move charges of a task when a task is moved into this
329 * mem_cgroup ? And what type of charges should we move ?
331 unsigned long move_charge_at_immigrate
;
333 * set > 0 if pages under this cgroup are moving to other cgroup.
335 atomic_t moving_account
;
336 /* taken only while moving_account > 0 */
337 spinlock_t move_lock
;
341 struct mem_cgroup_stat_cpu __percpu
*stat
;
343 * used when a cpu is offlined or other synchronizations
344 * See mem_cgroup_read_stat().
346 struct mem_cgroup_stat_cpu nocpu_base
;
347 spinlock_t pcp_counter_lock
;
350 #if defined(CONFIG_MEMCG_KMEM) && defined(CONFIG_INET)
351 struct tcp_memcontrol tcp_mem
;
353 #if defined(CONFIG_MEMCG_KMEM)
354 /* analogous to slab_common's slab_caches list. per-memcg */
355 struct list_head memcg_slab_caches
;
356 /* Not a spinlock, we can take a lot of time walking the list */
357 struct mutex slab_caches_mutex
;
358 /* Index in the kmem_cache->memcg_params->memcg_caches array */
362 int last_scanned_node
;
364 nodemask_t scan_nodes
;
365 atomic_t numainfo_events
;
366 atomic_t numainfo_updating
;
370 * Per cgroup active and inactive list, similar to the
371 * per zone LRU lists.
373 * WARNING: This has to be the last element of the struct. Don't
374 * add new fields after this point.
376 struct mem_cgroup_lru_info info
;
379 static size_t memcg_size(void)
381 return sizeof(struct mem_cgroup
) +
382 nr_node_ids
* sizeof(struct mem_cgroup_per_node
);
385 /* internal only representation about the status of kmem accounting. */
387 KMEM_ACCOUNTED_ACTIVE
= 0, /* accounted by this cgroup itself */
388 KMEM_ACCOUNTED_ACTIVATED
, /* static key enabled. */
389 KMEM_ACCOUNTED_DEAD
, /* dead memcg with pending kmem charges */
392 /* We account when limit is on, but only after call sites are patched */
393 #define KMEM_ACCOUNTED_MASK \
394 ((1 << KMEM_ACCOUNTED_ACTIVE) | (1 << KMEM_ACCOUNTED_ACTIVATED))
396 #ifdef CONFIG_MEMCG_KMEM
397 static inline void memcg_kmem_set_active(struct mem_cgroup
*memcg
)
399 set_bit(KMEM_ACCOUNTED_ACTIVE
, &memcg
->kmem_account_flags
);
402 static bool memcg_kmem_is_active(struct mem_cgroup
*memcg
)
404 return test_bit(KMEM_ACCOUNTED_ACTIVE
, &memcg
->kmem_account_flags
);
407 static void memcg_kmem_set_activated(struct mem_cgroup
*memcg
)
409 set_bit(KMEM_ACCOUNTED_ACTIVATED
, &memcg
->kmem_account_flags
);
412 static void memcg_kmem_clear_activated(struct mem_cgroup
*memcg
)
414 clear_bit(KMEM_ACCOUNTED_ACTIVATED
, &memcg
->kmem_account_flags
);
417 static void memcg_kmem_mark_dead(struct mem_cgroup
*memcg
)
419 if (test_bit(KMEM_ACCOUNTED_ACTIVE
, &memcg
->kmem_account_flags
))
420 set_bit(KMEM_ACCOUNTED_DEAD
, &memcg
->kmem_account_flags
);
423 static bool memcg_kmem_test_and_clear_dead(struct mem_cgroup
*memcg
)
425 return test_and_clear_bit(KMEM_ACCOUNTED_DEAD
,
426 &memcg
->kmem_account_flags
);
430 /* Stuffs for move charges at task migration. */
432 * Types of charges to be moved. "move_charge_at_immitgrate" and
433 * "immigrate_flags" are treated as a left-shifted bitmap of these types.
436 MOVE_CHARGE_TYPE_ANON
, /* private anonymous page and swap of it */
437 MOVE_CHARGE_TYPE_FILE
, /* file page(including tmpfs) and swap of it */
441 /* "mc" and its members are protected by cgroup_mutex */
442 static struct move_charge_struct
{
443 spinlock_t lock
; /* for from, to */
444 struct mem_cgroup
*from
;
445 struct mem_cgroup
*to
;
446 unsigned long immigrate_flags
;
447 unsigned long precharge
;
448 unsigned long moved_charge
;
449 unsigned long moved_swap
;
450 struct task_struct
*moving_task
; /* a task moving charges */
451 wait_queue_head_t waitq
; /* a waitq for other context */
453 .lock
= __SPIN_LOCK_UNLOCKED(mc
.lock
),
454 .waitq
= __WAIT_QUEUE_HEAD_INITIALIZER(mc
.waitq
),
457 static bool move_anon(void)
459 return test_bit(MOVE_CHARGE_TYPE_ANON
, &mc
.immigrate_flags
);
462 static bool move_file(void)
464 return test_bit(MOVE_CHARGE_TYPE_FILE
, &mc
.immigrate_flags
);
468 * Maximum loops in mem_cgroup_hierarchical_reclaim(), used for soft
469 * limit reclaim to prevent infinite loops, if they ever occur.
471 #define MEM_CGROUP_MAX_RECLAIM_LOOPS 100
472 #define MEM_CGROUP_MAX_SOFT_LIMIT_RECLAIM_LOOPS 2
475 MEM_CGROUP_CHARGE_TYPE_CACHE
= 0,
476 MEM_CGROUP_CHARGE_TYPE_ANON
,
477 MEM_CGROUP_CHARGE_TYPE_SWAPOUT
, /* for accounting swapcache */
478 MEM_CGROUP_CHARGE_TYPE_DROP
, /* a page was unused swap cache */
482 /* for encoding cft->private value on file */
490 #define MEMFILE_PRIVATE(x, val) ((x) << 16 | (val))
491 #define MEMFILE_TYPE(val) ((val) >> 16 & 0xffff)
492 #define MEMFILE_ATTR(val) ((val) & 0xffff)
493 /* Used for OOM nofiier */
494 #define OOM_CONTROL (0)
497 * Reclaim flags for mem_cgroup_hierarchical_reclaim
499 #define MEM_CGROUP_RECLAIM_NOSWAP_BIT 0x0
500 #define MEM_CGROUP_RECLAIM_NOSWAP (1 << MEM_CGROUP_RECLAIM_NOSWAP_BIT)
501 #define MEM_CGROUP_RECLAIM_SHRINK_BIT 0x1
502 #define MEM_CGROUP_RECLAIM_SHRINK (1 << MEM_CGROUP_RECLAIM_SHRINK_BIT)
505 * The memcg_create_mutex will be held whenever a new cgroup is created.
506 * As a consequence, any change that needs to protect against new child cgroups
507 * appearing has to hold it as well.
509 static DEFINE_MUTEX(memcg_create_mutex
);
511 static void mem_cgroup_get(struct mem_cgroup
*memcg
);
512 static void mem_cgroup_put(struct mem_cgroup
*memcg
);
515 struct mem_cgroup
*mem_cgroup_from_css(struct cgroup_subsys_state
*s
)
517 return container_of(s
, struct mem_cgroup
, css
);
520 /* Some nice accessors for the vmpressure. */
521 struct vmpressure
*memcg_to_vmpressure(struct mem_cgroup
*memcg
)
524 memcg
= root_mem_cgroup
;
525 return &memcg
->vmpressure
;
528 struct cgroup_subsys_state
*vmpressure_to_css(struct vmpressure
*vmpr
)
530 return &container_of(vmpr
, struct mem_cgroup
, vmpressure
)->css
;
533 struct vmpressure
*css_to_vmpressure(struct cgroup_subsys_state
*css
)
535 return &mem_cgroup_from_css(css
)->vmpressure
;
538 static inline bool mem_cgroup_is_root(struct mem_cgroup
*memcg
)
540 return (memcg
== root_mem_cgroup
);
543 /* Writing them here to avoid exposing memcg's inner layout */
544 #if defined(CONFIG_INET) && defined(CONFIG_MEMCG_KMEM)
546 void sock_update_memcg(struct sock
*sk
)
548 if (mem_cgroup_sockets_enabled
) {
549 struct mem_cgroup
*memcg
;
550 struct cg_proto
*cg_proto
;
552 BUG_ON(!sk
->sk_prot
->proto_cgroup
);
554 /* Socket cloning can throw us here with sk_cgrp already
555 * filled. It won't however, necessarily happen from
556 * process context. So the test for root memcg given
557 * the current task's memcg won't help us in this case.
559 * Respecting the original socket's memcg is a better
560 * decision in this case.
563 BUG_ON(mem_cgroup_is_root(sk
->sk_cgrp
->memcg
));
564 mem_cgroup_get(sk
->sk_cgrp
->memcg
);
569 memcg
= mem_cgroup_from_task(current
);
570 cg_proto
= sk
->sk_prot
->proto_cgroup(memcg
);
571 if (!mem_cgroup_is_root(memcg
) && memcg_proto_active(cg_proto
)) {
572 mem_cgroup_get(memcg
);
573 sk
->sk_cgrp
= cg_proto
;
578 EXPORT_SYMBOL(sock_update_memcg
);
580 void sock_release_memcg(struct sock
*sk
)
582 if (mem_cgroup_sockets_enabled
&& sk
->sk_cgrp
) {
583 struct mem_cgroup
*memcg
;
584 WARN_ON(!sk
->sk_cgrp
->memcg
);
585 memcg
= sk
->sk_cgrp
->memcg
;
586 mem_cgroup_put(memcg
);
590 struct cg_proto
*tcp_proto_cgroup(struct mem_cgroup
*memcg
)
592 if (!memcg
|| mem_cgroup_is_root(memcg
))
595 return &memcg
->tcp_mem
.cg_proto
;
597 EXPORT_SYMBOL(tcp_proto_cgroup
);
599 static void disarm_sock_keys(struct mem_cgroup
*memcg
)
601 if (!memcg_proto_activated(&memcg
->tcp_mem
.cg_proto
))
603 static_key_slow_dec(&memcg_socket_limit_enabled
);
606 static void disarm_sock_keys(struct mem_cgroup
*memcg
)
611 #ifdef CONFIG_MEMCG_KMEM
613 * This will be the memcg's index in each cache's ->memcg_params->memcg_caches.
614 * There are two main reasons for not using the css_id for this:
615 * 1) this works better in sparse environments, where we have a lot of memcgs,
616 * but only a few kmem-limited. Or also, if we have, for instance, 200
617 * memcgs, and none but the 200th is kmem-limited, we'd have to have a
618 * 200 entry array for that.
620 * 2) In order not to violate the cgroup API, we would like to do all memory
621 * allocation in ->create(). At that point, we haven't yet allocated the
622 * css_id. Having a separate index prevents us from messing with the cgroup
625 * The current size of the caches array is stored in
626 * memcg_limited_groups_array_size. It will double each time we have to
629 static DEFINE_IDA(kmem_limited_groups
);
630 int memcg_limited_groups_array_size
;
633 * MIN_SIZE is different than 1, because we would like to avoid going through
634 * the alloc/free process all the time. In a small machine, 4 kmem-limited
635 * cgroups is a reasonable guess. In the future, it could be a parameter or
636 * tunable, but that is strictly not necessary.
638 * MAX_SIZE should be as large as the number of css_ids. Ideally, we could get
639 * this constant directly from cgroup, but it is understandable that this is
640 * better kept as an internal representation in cgroup.c. In any case, the
641 * css_id space is not getting any smaller, and we don't have to necessarily
642 * increase ours as well if it increases.
644 #define MEMCG_CACHES_MIN_SIZE 4
645 #define MEMCG_CACHES_MAX_SIZE 65535
648 * A lot of the calls to the cache allocation functions are expected to be
649 * inlined by the compiler. Since the calls to memcg_kmem_get_cache are
650 * conditional to this static branch, we'll have to allow modules that does
651 * kmem_cache_alloc and the such to see this symbol as well
653 struct static_key memcg_kmem_enabled_key
;
654 EXPORT_SYMBOL(memcg_kmem_enabled_key
);
656 static void disarm_kmem_keys(struct mem_cgroup
*memcg
)
658 if (memcg_kmem_is_active(memcg
)) {
659 static_key_slow_dec(&memcg_kmem_enabled_key
);
660 ida_simple_remove(&kmem_limited_groups
, memcg
->kmemcg_id
);
663 * This check can't live in kmem destruction function,
664 * since the charges will outlive the cgroup
666 WARN_ON(res_counter_read_u64(&memcg
->kmem
, RES_USAGE
) != 0);
669 static void disarm_kmem_keys(struct mem_cgroup
*memcg
)
672 #endif /* CONFIG_MEMCG_KMEM */
674 static void disarm_static_keys(struct mem_cgroup
*memcg
)
676 disarm_sock_keys(memcg
);
677 disarm_kmem_keys(memcg
);
680 static void drain_all_stock_async(struct mem_cgroup
*memcg
);
682 static struct mem_cgroup_per_zone
*
683 mem_cgroup_zoneinfo(struct mem_cgroup
*memcg
, int nid
, int zid
)
685 VM_BUG_ON((unsigned)nid
>= nr_node_ids
);
686 return &memcg
->info
.nodeinfo
[nid
]->zoneinfo
[zid
];
689 struct cgroup_subsys_state
*mem_cgroup_css(struct mem_cgroup
*memcg
)
694 static struct mem_cgroup_per_zone
*
695 page_cgroup_zoneinfo(struct mem_cgroup
*memcg
, struct page
*page
)
697 int nid
= page_to_nid(page
);
698 int zid
= page_zonenum(page
);
700 return mem_cgroup_zoneinfo(memcg
, nid
, zid
);
703 static struct mem_cgroup_tree_per_zone
*
704 soft_limit_tree_node_zone(int nid
, int zid
)
706 return &soft_limit_tree
.rb_tree_per_node
[nid
]->rb_tree_per_zone
[zid
];
709 static struct mem_cgroup_tree_per_zone
*
710 soft_limit_tree_from_page(struct page
*page
)
712 int nid
= page_to_nid(page
);
713 int zid
= page_zonenum(page
);
715 return &soft_limit_tree
.rb_tree_per_node
[nid
]->rb_tree_per_zone
[zid
];
719 __mem_cgroup_insert_exceeded(struct mem_cgroup
*memcg
,
720 struct mem_cgroup_per_zone
*mz
,
721 struct mem_cgroup_tree_per_zone
*mctz
,
722 unsigned long long new_usage_in_excess
)
724 struct rb_node
**p
= &mctz
->rb_root
.rb_node
;
725 struct rb_node
*parent
= NULL
;
726 struct mem_cgroup_per_zone
*mz_node
;
731 mz
->usage_in_excess
= new_usage_in_excess
;
732 if (!mz
->usage_in_excess
)
736 mz_node
= rb_entry(parent
, struct mem_cgroup_per_zone
,
738 if (mz
->usage_in_excess
< mz_node
->usage_in_excess
)
741 * We can't avoid mem cgroups that are over their soft
742 * limit by the same amount
744 else if (mz
->usage_in_excess
>= mz_node
->usage_in_excess
)
747 rb_link_node(&mz
->tree_node
, parent
, p
);
748 rb_insert_color(&mz
->tree_node
, &mctz
->rb_root
);
753 __mem_cgroup_remove_exceeded(struct mem_cgroup
*memcg
,
754 struct mem_cgroup_per_zone
*mz
,
755 struct mem_cgroup_tree_per_zone
*mctz
)
759 rb_erase(&mz
->tree_node
, &mctz
->rb_root
);
764 mem_cgroup_remove_exceeded(struct mem_cgroup
*memcg
,
765 struct mem_cgroup_per_zone
*mz
,
766 struct mem_cgroup_tree_per_zone
*mctz
)
768 spin_lock(&mctz
->lock
);
769 __mem_cgroup_remove_exceeded(memcg
, mz
, mctz
);
770 spin_unlock(&mctz
->lock
);
774 static void mem_cgroup_update_tree(struct mem_cgroup
*memcg
, struct page
*page
)
776 unsigned long long excess
;
777 struct mem_cgroup_per_zone
*mz
;
778 struct mem_cgroup_tree_per_zone
*mctz
;
779 int nid
= page_to_nid(page
);
780 int zid
= page_zonenum(page
);
781 mctz
= soft_limit_tree_from_page(page
);
784 * Necessary to update all ancestors when hierarchy is used.
785 * because their event counter is not touched.
787 for (; memcg
; memcg
= parent_mem_cgroup(memcg
)) {
788 mz
= mem_cgroup_zoneinfo(memcg
, nid
, zid
);
789 excess
= res_counter_soft_limit_excess(&memcg
->res
);
791 * We have to update the tree if mz is on RB-tree or
792 * mem is over its softlimit.
794 if (excess
|| mz
->on_tree
) {
795 spin_lock(&mctz
->lock
);
796 /* if on-tree, remove it */
798 __mem_cgroup_remove_exceeded(memcg
, mz
, mctz
);
800 * Insert again. mz->usage_in_excess will be updated.
801 * If excess is 0, no tree ops.
803 __mem_cgroup_insert_exceeded(memcg
, mz
, mctz
, excess
);
804 spin_unlock(&mctz
->lock
);
809 static void mem_cgroup_remove_from_trees(struct mem_cgroup
*memcg
)
812 struct mem_cgroup_per_zone
*mz
;
813 struct mem_cgroup_tree_per_zone
*mctz
;
815 for_each_node(node
) {
816 for (zone
= 0; zone
< MAX_NR_ZONES
; zone
++) {
817 mz
= mem_cgroup_zoneinfo(memcg
, node
, zone
);
818 mctz
= soft_limit_tree_node_zone(node
, zone
);
819 mem_cgroup_remove_exceeded(memcg
, mz
, mctz
);
824 static struct mem_cgroup_per_zone
*
825 __mem_cgroup_largest_soft_limit_node(struct mem_cgroup_tree_per_zone
*mctz
)
827 struct rb_node
*rightmost
= NULL
;
828 struct mem_cgroup_per_zone
*mz
;
832 rightmost
= rb_last(&mctz
->rb_root
);
834 goto done
; /* Nothing to reclaim from */
836 mz
= rb_entry(rightmost
, struct mem_cgroup_per_zone
, tree_node
);
838 * Remove the node now but someone else can add it back,
839 * we will to add it back at the end of reclaim to its correct
840 * position in the tree.
842 __mem_cgroup_remove_exceeded(mz
->memcg
, mz
, mctz
);
843 if (!res_counter_soft_limit_excess(&mz
->memcg
->res
) ||
844 !css_tryget(&mz
->memcg
->css
))
850 static struct mem_cgroup_per_zone
*
851 mem_cgroup_largest_soft_limit_node(struct mem_cgroup_tree_per_zone
*mctz
)
853 struct mem_cgroup_per_zone
*mz
;
855 spin_lock(&mctz
->lock
);
856 mz
= __mem_cgroup_largest_soft_limit_node(mctz
);
857 spin_unlock(&mctz
->lock
);
862 * Implementation Note: reading percpu statistics for memcg.
864 * Both of vmstat[] and percpu_counter has threshold and do periodic
865 * synchronization to implement "quick" read. There are trade-off between
866 * reading cost and precision of value. Then, we may have a chance to implement
867 * a periodic synchronizion of counter in memcg's counter.
869 * But this _read() function is used for user interface now. The user accounts
870 * memory usage by memory cgroup and he _always_ requires exact value because
871 * he accounts memory. Even if we provide quick-and-fuzzy read, we always
872 * have to visit all online cpus and make sum. So, for now, unnecessary
873 * synchronization is not implemented. (just implemented for cpu hotplug)
875 * If there are kernel internal actions which can make use of some not-exact
876 * value, and reading all cpu value can be performance bottleneck in some
877 * common workload, threashold and synchonization as vmstat[] should be
880 static long mem_cgroup_read_stat(struct mem_cgroup
*memcg
,
881 enum mem_cgroup_stat_index idx
)
887 for_each_online_cpu(cpu
)
888 val
+= per_cpu(memcg
->stat
->count
[idx
], cpu
);
889 #ifdef CONFIG_HOTPLUG_CPU
890 spin_lock(&memcg
->pcp_counter_lock
);
891 val
+= memcg
->nocpu_base
.count
[idx
];
892 spin_unlock(&memcg
->pcp_counter_lock
);
898 static void mem_cgroup_swap_statistics(struct mem_cgroup
*memcg
,
901 int val
= (charge
) ? 1 : -1;
902 this_cpu_add(memcg
->stat
->count
[MEM_CGROUP_STAT_SWAP
], val
);
905 static unsigned long mem_cgroup_read_events(struct mem_cgroup
*memcg
,
906 enum mem_cgroup_events_index idx
)
908 unsigned long val
= 0;
911 for_each_online_cpu(cpu
)
912 val
+= per_cpu(memcg
->stat
->events
[idx
], cpu
);
913 #ifdef CONFIG_HOTPLUG_CPU
914 spin_lock(&memcg
->pcp_counter_lock
);
915 val
+= memcg
->nocpu_base
.events
[idx
];
916 spin_unlock(&memcg
->pcp_counter_lock
);
921 static void mem_cgroup_charge_statistics(struct mem_cgroup
*memcg
,
923 bool anon
, int nr_pages
)
928 * Here, RSS means 'mapped anon' and anon's SwapCache. Shmem/tmpfs is
929 * counted as CACHE even if it's on ANON LRU.
932 __this_cpu_add(memcg
->stat
->count
[MEM_CGROUP_STAT_RSS
],
935 __this_cpu_add(memcg
->stat
->count
[MEM_CGROUP_STAT_CACHE
],
938 if (PageTransHuge(page
))
939 __this_cpu_add(memcg
->stat
->count
[MEM_CGROUP_STAT_RSS_HUGE
],
942 /* pagein of a big page is an event. So, ignore page size */
944 __this_cpu_inc(memcg
->stat
->events
[MEM_CGROUP_EVENTS_PGPGIN
]);
946 __this_cpu_inc(memcg
->stat
->events
[MEM_CGROUP_EVENTS_PGPGOUT
]);
947 nr_pages
= -nr_pages
; /* for event */
950 __this_cpu_add(memcg
->stat
->nr_page_events
, nr_pages
);
956 mem_cgroup_get_lru_size(struct lruvec
*lruvec
, enum lru_list lru
)
958 struct mem_cgroup_per_zone
*mz
;
960 mz
= container_of(lruvec
, struct mem_cgroup_per_zone
, lruvec
);
961 return mz
->lru_size
[lru
];
965 mem_cgroup_zone_nr_lru_pages(struct mem_cgroup
*memcg
, int nid
, int zid
,
966 unsigned int lru_mask
)
968 struct mem_cgroup_per_zone
*mz
;
970 unsigned long ret
= 0;
972 mz
= mem_cgroup_zoneinfo(memcg
, nid
, zid
);
975 if (BIT(lru
) & lru_mask
)
976 ret
+= mz
->lru_size
[lru
];
982 mem_cgroup_node_nr_lru_pages(struct mem_cgroup
*memcg
,
983 int nid
, unsigned int lru_mask
)
988 for (zid
= 0; zid
< MAX_NR_ZONES
; zid
++)
989 total
+= mem_cgroup_zone_nr_lru_pages(memcg
,
995 static unsigned long mem_cgroup_nr_lru_pages(struct mem_cgroup
*memcg
,
996 unsigned int lru_mask
)
1001 for_each_node_state(nid
, N_MEMORY
)
1002 total
+= mem_cgroup_node_nr_lru_pages(memcg
, nid
, lru_mask
);
1006 static bool mem_cgroup_event_ratelimit(struct mem_cgroup
*memcg
,
1007 enum mem_cgroup_events_target target
)
1009 unsigned long val
, next
;
1011 val
= __this_cpu_read(memcg
->stat
->nr_page_events
);
1012 next
= __this_cpu_read(memcg
->stat
->targets
[target
]);
1013 /* from time_after() in jiffies.h */
1014 if ((long)next
- (long)val
< 0) {
1016 case MEM_CGROUP_TARGET_THRESH
:
1017 next
= val
+ THRESHOLDS_EVENTS_TARGET
;
1019 case MEM_CGROUP_TARGET_SOFTLIMIT
:
1020 next
= val
+ SOFTLIMIT_EVENTS_TARGET
;
1022 case MEM_CGROUP_TARGET_NUMAINFO
:
1023 next
= val
+ NUMAINFO_EVENTS_TARGET
;
1028 __this_cpu_write(memcg
->stat
->targets
[target
], next
);
1035 * Check events in order.
1038 static void memcg_check_events(struct mem_cgroup
*memcg
, struct page
*page
)
1041 /* threshold event is triggered in finer grain than soft limit */
1042 if (unlikely(mem_cgroup_event_ratelimit(memcg
,
1043 MEM_CGROUP_TARGET_THRESH
))) {
1045 bool do_numainfo __maybe_unused
;
1047 do_softlimit
= mem_cgroup_event_ratelimit(memcg
,
1048 MEM_CGROUP_TARGET_SOFTLIMIT
);
1049 #if MAX_NUMNODES > 1
1050 do_numainfo
= mem_cgroup_event_ratelimit(memcg
,
1051 MEM_CGROUP_TARGET_NUMAINFO
);
1055 mem_cgroup_threshold(memcg
);
1056 if (unlikely(do_softlimit
))
1057 mem_cgroup_update_tree(memcg
, page
);
1058 #if MAX_NUMNODES > 1
1059 if (unlikely(do_numainfo
))
1060 atomic_inc(&memcg
->numainfo_events
);
1066 struct mem_cgroup
*mem_cgroup_from_cont(struct cgroup
*cont
)
1068 return mem_cgroup_from_css(
1069 cgroup_subsys_state(cont
, mem_cgroup_subsys_id
));
1072 struct mem_cgroup
*mem_cgroup_from_task(struct task_struct
*p
)
1075 * mm_update_next_owner() may clear mm->owner to NULL
1076 * if it races with swapoff, page migration, etc.
1077 * So this can be called with p == NULL.
1082 return mem_cgroup_from_css(task_subsys_state(p
, mem_cgroup_subsys_id
));
1085 struct mem_cgroup
*try_get_mem_cgroup_from_mm(struct mm_struct
*mm
)
1087 struct mem_cgroup
*memcg
= NULL
;
1092 * Because we have no locks, mm->owner's may be being moved to other
1093 * cgroup. We use css_tryget() here even if this looks
1094 * pessimistic (rather than adding locks here).
1098 memcg
= mem_cgroup_from_task(rcu_dereference(mm
->owner
));
1099 if (unlikely(!memcg
))
1101 } while (!css_tryget(&memcg
->css
));
1107 * Returns a next (in a pre-order walk) alive memcg (with elevated css
1108 * ref. count) or NULL if the whole root's subtree has been visited.
1110 * helper function to be used by mem_cgroup_iter
1112 static struct mem_cgroup
*__mem_cgroup_iter_next(struct mem_cgroup
*root
,
1113 struct mem_cgroup
*last_visited
)
1115 struct cgroup
*prev_cgroup
, *next_cgroup
;
1118 * Root is not visited by cgroup iterators so it needs an
1124 prev_cgroup
= (last_visited
== root
) ? NULL
1125 : last_visited
->css
.cgroup
;
1127 next_cgroup
= cgroup_next_descendant_pre(
1128 prev_cgroup
, root
->css
.cgroup
);
1131 * Even if we found a group we have to make sure it is
1132 * alive. css && !memcg means that the groups should be
1133 * skipped and we should continue the tree walk.
1134 * last_visited css is safe to use because it is
1135 * protected by css_get and the tree walk is rcu safe.
1138 struct mem_cgroup
*mem
= mem_cgroup_from_cont(
1140 if (css_tryget(&mem
->css
))
1143 prev_cgroup
= next_cgroup
;
1152 * mem_cgroup_iter - iterate over memory cgroup hierarchy
1153 * @root: hierarchy root
1154 * @prev: previously returned memcg, NULL on first invocation
1155 * @reclaim: cookie for shared reclaim walks, NULL for full walks
1157 * Returns references to children of the hierarchy below @root, or
1158 * @root itself, or %NULL after a full round-trip.
1160 * Caller must pass the return value in @prev on subsequent
1161 * invocations for reference counting, or use mem_cgroup_iter_break()
1162 * to cancel a hierarchy walk before the round-trip is complete.
1164 * Reclaimers can specify a zone and a priority level in @reclaim to
1165 * divide up the memcgs in the hierarchy among all concurrent
1166 * reclaimers operating on the same zone and priority.
1168 struct mem_cgroup
*mem_cgroup_iter(struct mem_cgroup
*root
,
1169 struct mem_cgroup
*prev
,
1170 struct mem_cgroup_reclaim_cookie
*reclaim
)
1172 struct mem_cgroup
*memcg
= NULL
;
1173 struct mem_cgroup
*last_visited
= NULL
;
1174 unsigned long uninitialized_var(dead_count
);
1176 if (mem_cgroup_disabled())
1180 root
= root_mem_cgroup
;
1182 if (prev
&& !reclaim
)
1183 last_visited
= prev
;
1185 if (!root
->use_hierarchy
&& root
!= root_mem_cgroup
) {
1193 struct mem_cgroup_reclaim_iter
*uninitialized_var(iter
);
1196 int nid
= zone_to_nid(reclaim
->zone
);
1197 int zid
= zone_idx(reclaim
->zone
);
1198 struct mem_cgroup_per_zone
*mz
;
1200 mz
= mem_cgroup_zoneinfo(root
, nid
, zid
);
1201 iter
= &mz
->reclaim_iter
[reclaim
->priority
];
1202 if (prev
&& reclaim
->generation
!= iter
->generation
) {
1203 iter
->last_visited
= NULL
;
1208 * If the dead_count mismatches, a destruction
1209 * has happened or is happening concurrently.
1210 * If the dead_count matches, a destruction
1211 * might still happen concurrently, but since
1212 * we checked under RCU, that destruction
1213 * won't free the object until we release the
1214 * RCU reader lock. Thus, the dead_count
1215 * check verifies the pointer is still valid,
1216 * css_tryget() verifies the cgroup pointed to
1219 dead_count
= atomic_read(&root
->dead_count
);
1220 if (dead_count
== iter
->last_dead_count
) {
1222 last_visited
= iter
->last_visited
;
1224 !css_tryget(&last_visited
->css
))
1225 last_visited
= NULL
;
1229 memcg
= __mem_cgroup_iter_next(root
, last_visited
);
1233 css_put(&last_visited
->css
);
1235 iter
->last_visited
= memcg
;
1237 iter
->last_dead_count
= dead_count
;
1241 else if (!prev
&& memcg
)
1242 reclaim
->generation
= iter
->generation
;
1251 if (prev
&& prev
!= root
)
1252 css_put(&prev
->css
);
1258 * mem_cgroup_iter_break - abort a hierarchy walk prematurely
1259 * @root: hierarchy root
1260 * @prev: last visited hierarchy member as returned by mem_cgroup_iter()
1262 void mem_cgroup_iter_break(struct mem_cgroup
*root
,
1263 struct mem_cgroup
*prev
)
1266 root
= root_mem_cgroup
;
1267 if (prev
&& prev
!= root
)
1268 css_put(&prev
->css
);
1272 * Iteration constructs for visiting all cgroups (under a tree). If
1273 * loops are exited prematurely (break), mem_cgroup_iter_break() must
1274 * be used for reference counting.
1276 #define for_each_mem_cgroup_tree(iter, root) \
1277 for (iter = mem_cgroup_iter(root, NULL, NULL); \
1279 iter = mem_cgroup_iter(root, iter, NULL))
1281 #define for_each_mem_cgroup(iter) \
1282 for (iter = mem_cgroup_iter(NULL, NULL, NULL); \
1284 iter = mem_cgroup_iter(NULL, iter, NULL))
1286 void __mem_cgroup_count_vm_event(struct mm_struct
*mm
, enum vm_event_item idx
)
1288 struct mem_cgroup
*memcg
;
1291 memcg
= mem_cgroup_from_task(rcu_dereference(mm
->owner
));
1292 if (unlikely(!memcg
))
1297 this_cpu_inc(memcg
->stat
->events
[MEM_CGROUP_EVENTS_PGFAULT
]);
1300 this_cpu_inc(memcg
->stat
->events
[MEM_CGROUP_EVENTS_PGMAJFAULT
]);
1308 EXPORT_SYMBOL(__mem_cgroup_count_vm_event
);
1311 * mem_cgroup_zone_lruvec - get the lru list vector for a zone and memcg
1312 * @zone: zone of the wanted lruvec
1313 * @memcg: memcg of the wanted lruvec
1315 * Returns the lru list vector holding pages for the given @zone and
1316 * @mem. This can be the global zone lruvec, if the memory controller
1319 struct lruvec
*mem_cgroup_zone_lruvec(struct zone
*zone
,
1320 struct mem_cgroup
*memcg
)
1322 struct mem_cgroup_per_zone
*mz
;
1323 struct lruvec
*lruvec
;
1325 if (mem_cgroup_disabled()) {
1326 lruvec
= &zone
->lruvec
;
1330 mz
= mem_cgroup_zoneinfo(memcg
, zone_to_nid(zone
), zone_idx(zone
));
1331 lruvec
= &mz
->lruvec
;
1334 * Since a node can be onlined after the mem_cgroup was created,
1335 * we have to be prepared to initialize lruvec->zone here;
1336 * and if offlined then reonlined, we need to reinitialize it.
1338 if (unlikely(lruvec
->zone
!= zone
))
1339 lruvec
->zone
= zone
;
1344 * Following LRU functions are allowed to be used without PCG_LOCK.
1345 * Operations are called by routine of global LRU independently from memcg.
1346 * What we have to take care of here is validness of pc->mem_cgroup.
1348 * Changes to pc->mem_cgroup happens when
1351 * In typical case, "charge" is done before add-to-lru. Exception is SwapCache.
1352 * It is added to LRU before charge.
1353 * If PCG_USED bit is not set, page_cgroup is not added to this private LRU.
1354 * When moving account, the page is not on LRU. It's isolated.
1358 * mem_cgroup_page_lruvec - return lruvec for adding an lru page
1360 * @zone: zone of the page
1362 struct lruvec
*mem_cgroup_page_lruvec(struct page
*page
, struct zone
*zone
)
1364 struct mem_cgroup_per_zone
*mz
;
1365 struct mem_cgroup
*memcg
;
1366 struct page_cgroup
*pc
;
1367 struct lruvec
*lruvec
;
1369 if (mem_cgroup_disabled()) {
1370 lruvec
= &zone
->lruvec
;
1374 pc
= lookup_page_cgroup(page
);
1375 memcg
= pc
->mem_cgroup
;
1378 * Surreptitiously switch any uncharged offlist page to root:
1379 * an uncharged page off lru does nothing to secure
1380 * its former mem_cgroup from sudden removal.
1382 * Our caller holds lru_lock, and PageCgroupUsed is updated
1383 * under page_cgroup lock: between them, they make all uses
1384 * of pc->mem_cgroup safe.
1386 if (!PageLRU(page
) && !PageCgroupUsed(pc
) && memcg
!= root_mem_cgroup
)
1387 pc
->mem_cgroup
= memcg
= root_mem_cgroup
;
1389 mz
= page_cgroup_zoneinfo(memcg
, page
);
1390 lruvec
= &mz
->lruvec
;
1393 * Since a node can be onlined after the mem_cgroup was created,
1394 * we have to be prepared to initialize lruvec->zone here;
1395 * and if offlined then reonlined, we need to reinitialize it.
1397 if (unlikely(lruvec
->zone
!= zone
))
1398 lruvec
->zone
= zone
;
1403 * mem_cgroup_update_lru_size - account for adding or removing an lru page
1404 * @lruvec: mem_cgroup per zone lru vector
1405 * @lru: index of lru list the page is sitting on
1406 * @nr_pages: positive when adding or negative when removing
1408 * This function must be called when a page is added to or removed from an
1411 void mem_cgroup_update_lru_size(struct lruvec
*lruvec
, enum lru_list lru
,
1414 struct mem_cgroup_per_zone
*mz
;
1415 unsigned long *lru_size
;
1417 if (mem_cgroup_disabled())
1420 mz
= container_of(lruvec
, struct mem_cgroup_per_zone
, lruvec
);
1421 lru_size
= mz
->lru_size
+ lru
;
1422 *lru_size
+= nr_pages
;
1423 VM_BUG_ON((long)(*lru_size
) < 0);
1427 * Checks whether given mem is same or in the root_mem_cgroup's
1430 bool __mem_cgroup_same_or_subtree(const struct mem_cgroup
*root_memcg
,
1431 struct mem_cgroup
*memcg
)
1433 if (root_memcg
== memcg
)
1435 if (!root_memcg
->use_hierarchy
|| !memcg
)
1437 return css_is_ancestor(&memcg
->css
, &root_memcg
->css
);
1440 static bool mem_cgroup_same_or_subtree(const struct mem_cgroup
*root_memcg
,
1441 struct mem_cgroup
*memcg
)
1446 ret
= __mem_cgroup_same_or_subtree(root_memcg
, memcg
);
1451 bool task_in_mem_cgroup(struct task_struct
*task
,
1452 const struct mem_cgroup
*memcg
)
1454 struct mem_cgroup
*curr
= NULL
;
1455 struct task_struct
*p
;
1458 p
= find_lock_task_mm(task
);
1460 curr
= try_get_mem_cgroup_from_mm(p
->mm
);
1464 * All threads may have already detached their mm's, but the oom
1465 * killer still needs to detect if they have already been oom
1466 * killed to prevent needlessly killing additional tasks.
1469 curr
= mem_cgroup_from_task(task
);
1471 css_get(&curr
->css
);
1477 * We should check use_hierarchy of "memcg" not "curr". Because checking
1478 * use_hierarchy of "curr" here make this function true if hierarchy is
1479 * enabled in "curr" and "curr" is a child of "memcg" in *cgroup*
1480 * hierarchy(even if use_hierarchy is disabled in "memcg").
1482 ret
= mem_cgroup_same_or_subtree(memcg
, curr
);
1483 css_put(&curr
->css
);
1487 int mem_cgroup_inactive_anon_is_low(struct lruvec
*lruvec
)
1489 unsigned long inactive_ratio
;
1490 unsigned long inactive
;
1491 unsigned long active
;
1494 inactive
= mem_cgroup_get_lru_size(lruvec
, LRU_INACTIVE_ANON
);
1495 active
= mem_cgroup_get_lru_size(lruvec
, LRU_ACTIVE_ANON
);
1497 gb
= (inactive
+ active
) >> (30 - PAGE_SHIFT
);
1499 inactive_ratio
= int_sqrt(10 * gb
);
1503 return inactive
* inactive_ratio
< active
;
1506 #define mem_cgroup_from_res_counter(counter, member) \
1507 container_of(counter, struct mem_cgroup, member)
1510 * mem_cgroup_margin - calculate chargeable space of a memory cgroup
1511 * @memcg: the memory cgroup
1513 * Returns the maximum amount of memory @mem can be charged with, in
1516 static unsigned long mem_cgroup_margin(struct mem_cgroup
*memcg
)
1518 unsigned long long margin
;
1520 margin
= res_counter_margin(&memcg
->res
);
1521 if (do_swap_account
)
1522 margin
= min(margin
, res_counter_margin(&memcg
->memsw
));
1523 return margin
>> PAGE_SHIFT
;
1526 int mem_cgroup_swappiness(struct mem_cgroup
*memcg
)
1528 struct cgroup
*cgrp
= memcg
->css
.cgroup
;
1531 if (cgrp
->parent
== NULL
)
1532 return vm_swappiness
;
1534 return memcg
->swappiness
;
1538 * memcg->moving_account is used for checking possibility that some thread is
1539 * calling move_account(). When a thread on CPU-A starts moving pages under
1540 * a memcg, other threads should check memcg->moving_account under
1541 * rcu_read_lock(), like this:
1545 * memcg->moving_account+1 if (memcg->mocing_account)
1547 * synchronize_rcu() update something.
1552 /* for quick checking without looking up memcg */
1553 atomic_t memcg_moving __read_mostly
;
1555 static void mem_cgroup_start_move(struct mem_cgroup
*memcg
)
1557 atomic_inc(&memcg_moving
);
1558 atomic_inc(&memcg
->moving_account
);
1562 static void mem_cgroup_end_move(struct mem_cgroup
*memcg
)
1565 * Now, mem_cgroup_clear_mc() may call this function with NULL.
1566 * We check NULL in callee rather than caller.
1569 atomic_dec(&memcg_moving
);
1570 atomic_dec(&memcg
->moving_account
);
1575 * 2 routines for checking "mem" is under move_account() or not.
1577 * mem_cgroup_stolen() - checking whether a cgroup is mc.from or not. This
1578 * is used for avoiding races in accounting. If true,
1579 * pc->mem_cgroup may be overwritten.
1581 * mem_cgroup_under_move() - checking a cgroup is mc.from or mc.to or
1582 * under hierarchy of moving cgroups. This is for
1583 * waiting at hith-memory prressure caused by "move".
1586 static bool mem_cgroup_stolen(struct mem_cgroup
*memcg
)
1588 VM_BUG_ON(!rcu_read_lock_held());
1589 return atomic_read(&memcg
->moving_account
) > 0;
1592 static bool mem_cgroup_under_move(struct mem_cgroup
*memcg
)
1594 struct mem_cgroup
*from
;
1595 struct mem_cgroup
*to
;
1598 * Unlike task_move routines, we access mc.to, mc.from not under
1599 * mutual exclusion by cgroup_mutex. Here, we take spinlock instead.
1601 spin_lock(&mc
.lock
);
1607 ret
= mem_cgroup_same_or_subtree(memcg
, from
)
1608 || mem_cgroup_same_or_subtree(memcg
, to
);
1610 spin_unlock(&mc
.lock
);
1614 static bool mem_cgroup_wait_acct_move(struct mem_cgroup
*memcg
)
1616 if (mc
.moving_task
&& current
!= mc
.moving_task
) {
1617 if (mem_cgroup_under_move(memcg
)) {
1619 prepare_to_wait(&mc
.waitq
, &wait
, TASK_INTERRUPTIBLE
);
1620 /* moving charge context might have finished. */
1623 finish_wait(&mc
.waitq
, &wait
);
1631 * Take this lock when
1632 * - a code tries to modify page's memcg while it's USED.
1633 * - a code tries to modify page state accounting in a memcg.
1634 * see mem_cgroup_stolen(), too.
1636 static void move_lock_mem_cgroup(struct mem_cgroup
*memcg
,
1637 unsigned long *flags
)
1639 spin_lock_irqsave(&memcg
->move_lock
, *flags
);
1642 static void move_unlock_mem_cgroup(struct mem_cgroup
*memcg
,
1643 unsigned long *flags
)
1645 spin_unlock_irqrestore(&memcg
->move_lock
, *flags
);
1648 #define K(x) ((x) << (PAGE_SHIFT-10))
1650 * mem_cgroup_print_oom_info: Print OOM information relevant to memory controller.
1651 * @memcg: The memory cgroup that went over limit
1652 * @p: Task that is going to be killed
1654 * NOTE: @memcg and @p's mem_cgroup can be different when hierarchy is
1657 void mem_cgroup_print_oom_info(struct mem_cgroup
*memcg
, struct task_struct
*p
)
1659 struct cgroup
*task_cgrp
;
1660 struct cgroup
*mem_cgrp
;
1662 * Need a buffer in BSS, can't rely on allocations. The code relies
1663 * on the assumption that OOM is serialized for memory controller.
1664 * If this assumption is broken, revisit this code.
1666 static char memcg_name
[PATH_MAX
];
1668 struct mem_cgroup
*iter
;
1676 mem_cgrp
= memcg
->css
.cgroup
;
1677 task_cgrp
= task_cgroup(p
, mem_cgroup_subsys_id
);
1679 ret
= cgroup_path(task_cgrp
, memcg_name
, PATH_MAX
);
1682 * Unfortunately, we are unable to convert to a useful name
1683 * But we'll still print out the usage information
1690 pr_info("Task in %s killed", memcg_name
);
1693 ret
= cgroup_path(mem_cgrp
, memcg_name
, PATH_MAX
);
1701 * Continues from above, so we don't need an KERN_ level
1703 pr_cont(" as a result of limit of %s\n", memcg_name
);
1706 pr_info("memory: usage %llukB, limit %llukB, failcnt %llu\n",
1707 res_counter_read_u64(&memcg
->res
, RES_USAGE
) >> 10,
1708 res_counter_read_u64(&memcg
->res
, RES_LIMIT
) >> 10,
1709 res_counter_read_u64(&memcg
->res
, RES_FAILCNT
));
1710 pr_info("memory+swap: usage %llukB, limit %llukB, failcnt %llu\n",
1711 res_counter_read_u64(&memcg
->memsw
, RES_USAGE
) >> 10,
1712 res_counter_read_u64(&memcg
->memsw
, RES_LIMIT
) >> 10,
1713 res_counter_read_u64(&memcg
->memsw
, RES_FAILCNT
));
1714 pr_info("kmem: usage %llukB, limit %llukB, failcnt %llu\n",
1715 res_counter_read_u64(&memcg
->kmem
, RES_USAGE
) >> 10,
1716 res_counter_read_u64(&memcg
->kmem
, RES_LIMIT
) >> 10,
1717 res_counter_read_u64(&memcg
->kmem
, RES_FAILCNT
));
1719 for_each_mem_cgroup_tree(iter
, memcg
) {
1720 pr_info("Memory cgroup stats");
1723 ret
= cgroup_path(iter
->css
.cgroup
, memcg_name
, PATH_MAX
);
1725 pr_cont(" for %s", memcg_name
);
1729 for (i
= 0; i
< MEM_CGROUP_STAT_NSTATS
; i
++) {
1730 if (i
== MEM_CGROUP_STAT_SWAP
&& !do_swap_account
)
1732 pr_cont(" %s:%ldKB", mem_cgroup_stat_names
[i
],
1733 K(mem_cgroup_read_stat(iter
, i
)));
1736 for (i
= 0; i
< NR_LRU_LISTS
; i
++)
1737 pr_cont(" %s:%luKB", mem_cgroup_lru_names
[i
],
1738 K(mem_cgroup_nr_lru_pages(iter
, BIT(i
))));
1745 * This function returns the number of memcg under hierarchy tree. Returns
1746 * 1(self count) if no children.
1748 static int mem_cgroup_count_children(struct mem_cgroup
*memcg
)
1751 struct mem_cgroup
*iter
;
1753 for_each_mem_cgroup_tree(iter
, memcg
)
1759 * Return the memory (and swap, if configured) limit for a memcg.
1761 static u64
mem_cgroup_get_limit(struct mem_cgroup
*memcg
)
1765 limit
= res_counter_read_u64(&memcg
->res
, RES_LIMIT
);
1768 * Do not consider swap space if we cannot swap due to swappiness
1770 if (mem_cgroup_swappiness(memcg
)) {
1773 limit
+= total_swap_pages
<< PAGE_SHIFT
;
1774 memsw
= res_counter_read_u64(&memcg
->memsw
, RES_LIMIT
);
1777 * If memsw is finite and limits the amount of swap space
1778 * available to this memcg, return that limit.
1780 limit
= min(limit
, memsw
);
1786 static void mem_cgroup_out_of_memory(struct mem_cgroup
*memcg
, gfp_t gfp_mask
,
1789 struct mem_cgroup
*iter
;
1790 unsigned long chosen_points
= 0;
1791 unsigned long totalpages
;
1792 unsigned int points
= 0;
1793 struct task_struct
*chosen
= NULL
;
1796 * If current has a pending SIGKILL or is exiting, then automatically
1797 * select it. The goal is to allow it to allocate so that it may
1798 * quickly exit and free its memory.
1800 if (fatal_signal_pending(current
) || current
->flags
& PF_EXITING
) {
1801 set_thread_flag(TIF_MEMDIE
);
1805 check_panic_on_oom(CONSTRAINT_MEMCG
, gfp_mask
, order
, NULL
);
1806 totalpages
= mem_cgroup_get_limit(memcg
) >> PAGE_SHIFT
? : 1;
1807 for_each_mem_cgroup_tree(iter
, memcg
) {
1808 struct cgroup
*cgroup
= iter
->css
.cgroup
;
1809 struct cgroup_iter it
;
1810 struct task_struct
*task
;
1812 cgroup_iter_start(cgroup
, &it
);
1813 while ((task
= cgroup_iter_next(cgroup
, &it
))) {
1814 switch (oom_scan_process_thread(task
, totalpages
, NULL
,
1816 case OOM_SCAN_SELECT
:
1818 put_task_struct(chosen
);
1820 chosen_points
= ULONG_MAX
;
1821 get_task_struct(chosen
);
1823 case OOM_SCAN_CONTINUE
:
1825 case OOM_SCAN_ABORT
:
1826 cgroup_iter_end(cgroup
, &it
);
1827 mem_cgroup_iter_break(memcg
, iter
);
1829 put_task_struct(chosen
);
1834 points
= oom_badness(task
, memcg
, NULL
, totalpages
);
1835 if (points
> chosen_points
) {
1837 put_task_struct(chosen
);
1839 chosen_points
= points
;
1840 get_task_struct(chosen
);
1843 cgroup_iter_end(cgroup
, &it
);
1848 points
= chosen_points
* 1000 / totalpages
;
1849 oom_kill_process(chosen
, gfp_mask
, order
, points
, totalpages
, memcg
,
1850 NULL
, "Memory cgroup out of memory");
1853 static unsigned long mem_cgroup_reclaim(struct mem_cgroup
*memcg
,
1855 unsigned long flags
)
1857 unsigned long total
= 0;
1858 bool noswap
= false;
1861 if (flags
& MEM_CGROUP_RECLAIM_NOSWAP
)
1863 if (!(flags
& MEM_CGROUP_RECLAIM_SHRINK
) && memcg
->memsw_is_minimum
)
1866 for (loop
= 0; loop
< MEM_CGROUP_MAX_RECLAIM_LOOPS
; loop
++) {
1868 drain_all_stock_async(memcg
);
1869 total
+= try_to_free_mem_cgroup_pages(memcg
, gfp_mask
, noswap
);
1871 * Allow limit shrinkers, which are triggered directly
1872 * by userspace, to catch signals and stop reclaim
1873 * after minimal progress, regardless of the margin.
1875 if (total
&& (flags
& MEM_CGROUP_RECLAIM_SHRINK
))
1877 if (mem_cgroup_margin(memcg
))
1880 * If nothing was reclaimed after two attempts, there
1881 * may be no reclaimable pages in this hierarchy.
1890 * test_mem_cgroup_node_reclaimable
1891 * @memcg: the target memcg
1892 * @nid: the node ID to be checked.
1893 * @noswap : specify true here if the user wants flle only information.
1895 * This function returns whether the specified memcg contains any
1896 * reclaimable pages on a node. Returns true if there are any reclaimable
1897 * pages in the node.
1899 static bool test_mem_cgroup_node_reclaimable(struct mem_cgroup
*memcg
,
1900 int nid
, bool noswap
)
1902 if (mem_cgroup_node_nr_lru_pages(memcg
, nid
, LRU_ALL_FILE
))
1904 if (noswap
|| !total_swap_pages
)
1906 if (mem_cgroup_node_nr_lru_pages(memcg
, nid
, LRU_ALL_ANON
))
1911 #if MAX_NUMNODES > 1
1914 * Always updating the nodemask is not very good - even if we have an empty
1915 * list or the wrong list here, we can start from some node and traverse all
1916 * nodes based on the zonelist. So update the list loosely once per 10 secs.
1919 static void mem_cgroup_may_update_nodemask(struct mem_cgroup
*memcg
)
1923 * numainfo_events > 0 means there was at least NUMAINFO_EVENTS_TARGET
1924 * pagein/pageout changes since the last update.
1926 if (!atomic_read(&memcg
->numainfo_events
))
1928 if (atomic_inc_return(&memcg
->numainfo_updating
) > 1)
1931 /* make a nodemask where this memcg uses memory from */
1932 memcg
->scan_nodes
= node_states
[N_MEMORY
];
1934 for_each_node_mask(nid
, node_states
[N_MEMORY
]) {
1936 if (!test_mem_cgroup_node_reclaimable(memcg
, nid
, false))
1937 node_clear(nid
, memcg
->scan_nodes
);
1940 atomic_set(&memcg
->numainfo_events
, 0);
1941 atomic_set(&memcg
->numainfo_updating
, 0);
1945 * Selecting a node where we start reclaim from. Because what we need is just
1946 * reducing usage counter, start from anywhere is O,K. Considering
1947 * memory reclaim from current node, there are pros. and cons.
1949 * Freeing memory from current node means freeing memory from a node which
1950 * we'll use or we've used. So, it may make LRU bad. And if several threads
1951 * hit limits, it will see a contention on a node. But freeing from remote
1952 * node means more costs for memory reclaim because of memory latency.
1954 * Now, we use round-robin. Better algorithm is welcomed.
1956 int mem_cgroup_select_victim_node(struct mem_cgroup
*memcg
)
1960 mem_cgroup_may_update_nodemask(memcg
);
1961 node
= memcg
->last_scanned_node
;
1963 node
= next_node(node
, memcg
->scan_nodes
);
1964 if (node
== MAX_NUMNODES
)
1965 node
= first_node(memcg
->scan_nodes
);
1967 * We call this when we hit limit, not when pages are added to LRU.
1968 * No LRU may hold pages because all pages are UNEVICTABLE or
1969 * memcg is too small and all pages are not on LRU. In that case,
1970 * we use curret node.
1972 if (unlikely(node
== MAX_NUMNODES
))
1973 node
= numa_node_id();
1975 memcg
->last_scanned_node
= node
;
1980 * Check all nodes whether it contains reclaimable pages or not.
1981 * For quick scan, we make use of scan_nodes. This will allow us to skip
1982 * unused nodes. But scan_nodes is lazily updated and may not cotain
1983 * enough new information. We need to do double check.
1985 static bool mem_cgroup_reclaimable(struct mem_cgroup
*memcg
, bool noswap
)
1990 * quick check...making use of scan_node.
1991 * We can skip unused nodes.
1993 if (!nodes_empty(memcg
->scan_nodes
)) {
1994 for (nid
= first_node(memcg
->scan_nodes
);
1996 nid
= next_node(nid
, memcg
->scan_nodes
)) {
1998 if (test_mem_cgroup_node_reclaimable(memcg
, nid
, noswap
))
2003 * Check rest of nodes.
2005 for_each_node_state(nid
, N_MEMORY
) {
2006 if (node_isset(nid
, memcg
->scan_nodes
))
2008 if (test_mem_cgroup_node_reclaimable(memcg
, nid
, noswap
))
2015 int mem_cgroup_select_victim_node(struct mem_cgroup
*memcg
)
2020 static bool mem_cgroup_reclaimable(struct mem_cgroup
*memcg
, bool noswap
)
2022 return test_mem_cgroup_node_reclaimable(memcg
, 0, noswap
);
2026 static int mem_cgroup_soft_reclaim(struct mem_cgroup
*root_memcg
,
2029 unsigned long *total_scanned
)
2031 struct mem_cgroup
*victim
= NULL
;
2034 unsigned long excess
;
2035 unsigned long nr_scanned
;
2036 struct mem_cgroup_reclaim_cookie reclaim
= {
2041 excess
= res_counter_soft_limit_excess(&root_memcg
->res
) >> PAGE_SHIFT
;
2044 victim
= mem_cgroup_iter(root_memcg
, victim
, &reclaim
);
2049 * If we have not been able to reclaim
2050 * anything, it might because there are
2051 * no reclaimable pages under this hierarchy
2056 * We want to do more targeted reclaim.
2057 * excess >> 2 is not to excessive so as to
2058 * reclaim too much, nor too less that we keep
2059 * coming back to reclaim from this cgroup
2061 if (total
>= (excess
>> 2) ||
2062 (loop
> MEM_CGROUP_MAX_RECLAIM_LOOPS
))
2067 if (!mem_cgroup_reclaimable(victim
, false))
2069 total
+= mem_cgroup_shrink_node_zone(victim
, gfp_mask
, false,
2071 *total_scanned
+= nr_scanned
;
2072 if (!res_counter_soft_limit_excess(&root_memcg
->res
))
2075 mem_cgroup_iter_break(root_memcg
, victim
);
2080 * Check OOM-Killer is already running under our hierarchy.
2081 * If someone is running, return false.
2082 * Has to be called with memcg_oom_lock
2084 static bool mem_cgroup_oom_lock(struct mem_cgroup
*memcg
)
2086 struct mem_cgroup
*iter
, *failed
= NULL
;
2088 for_each_mem_cgroup_tree(iter
, memcg
) {
2089 if (iter
->oom_lock
) {
2091 * this subtree of our hierarchy is already locked
2092 * so we cannot give a lock.
2095 mem_cgroup_iter_break(memcg
, iter
);
2098 iter
->oom_lock
= true;
2105 * OK, we failed to lock the whole subtree so we have to clean up
2106 * what we set up to the failing subtree
2108 for_each_mem_cgroup_tree(iter
, memcg
) {
2109 if (iter
== failed
) {
2110 mem_cgroup_iter_break(memcg
, iter
);
2113 iter
->oom_lock
= false;
2119 * Has to be called with memcg_oom_lock
2121 static int mem_cgroup_oom_unlock(struct mem_cgroup
*memcg
)
2123 struct mem_cgroup
*iter
;
2125 for_each_mem_cgroup_tree(iter
, memcg
)
2126 iter
->oom_lock
= false;
2130 static void mem_cgroup_mark_under_oom(struct mem_cgroup
*memcg
)
2132 struct mem_cgroup
*iter
;
2134 for_each_mem_cgroup_tree(iter
, memcg
)
2135 atomic_inc(&iter
->under_oom
);
2138 static void mem_cgroup_unmark_under_oom(struct mem_cgroup
*memcg
)
2140 struct mem_cgroup
*iter
;
2143 * When a new child is created while the hierarchy is under oom,
2144 * mem_cgroup_oom_lock() may not be called. We have to use
2145 * atomic_add_unless() here.
2147 for_each_mem_cgroup_tree(iter
, memcg
)
2148 atomic_add_unless(&iter
->under_oom
, -1, 0);
2151 static DEFINE_SPINLOCK(memcg_oom_lock
);
2152 static DECLARE_WAIT_QUEUE_HEAD(memcg_oom_waitq
);
2154 struct oom_wait_info
{
2155 struct mem_cgroup
*memcg
;
2159 static int memcg_oom_wake_function(wait_queue_t
*wait
,
2160 unsigned mode
, int sync
, void *arg
)
2162 struct mem_cgroup
*wake_memcg
= (struct mem_cgroup
*)arg
;
2163 struct mem_cgroup
*oom_wait_memcg
;
2164 struct oom_wait_info
*oom_wait_info
;
2166 oom_wait_info
= container_of(wait
, struct oom_wait_info
, wait
);
2167 oom_wait_memcg
= oom_wait_info
->memcg
;
2170 * Both of oom_wait_info->memcg and wake_memcg are stable under us.
2171 * Then we can use css_is_ancestor without taking care of RCU.
2173 if (!mem_cgroup_same_or_subtree(oom_wait_memcg
, wake_memcg
)
2174 && !mem_cgroup_same_or_subtree(wake_memcg
, oom_wait_memcg
))
2176 return autoremove_wake_function(wait
, mode
, sync
, arg
);
2179 static void memcg_wakeup_oom(struct mem_cgroup
*memcg
)
2181 /* for filtering, pass "memcg" as argument. */
2182 __wake_up(&memcg_oom_waitq
, TASK_NORMAL
, 0, memcg
);
2185 static void memcg_oom_recover(struct mem_cgroup
*memcg
)
2187 if (memcg
&& atomic_read(&memcg
->under_oom
))
2188 memcg_wakeup_oom(memcg
);
2192 * try to call OOM killer. returns false if we should exit memory-reclaim loop.
2194 static bool mem_cgroup_handle_oom(struct mem_cgroup
*memcg
, gfp_t mask
,
2197 struct oom_wait_info owait
;
2198 bool locked
, need_to_kill
;
2200 owait
.memcg
= memcg
;
2201 owait
.wait
.flags
= 0;
2202 owait
.wait
.func
= memcg_oom_wake_function
;
2203 owait
.wait
.private = current
;
2204 INIT_LIST_HEAD(&owait
.wait
.task_list
);
2205 need_to_kill
= true;
2206 mem_cgroup_mark_under_oom(memcg
);
2208 /* At first, try to OOM lock hierarchy under memcg.*/
2209 spin_lock(&memcg_oom_lock
);
2210 locked
= mem_cgroup_oom_lock(memcg
);
2212 * Even if signal_pending(), we can't quit charge() loop without
2213 * accounting. So, UNINTERRUPTIBLE is appropriate. But SIGKILL
2214 * under OOM is always welcomed, use TASK_KILLABLE here.
2216 prepare_to_wait(&memcg_oom_waitq
, &owait
.wait
, TASK_KILLABLE
);
2217 if (!locked
|| memcg
->oom_kill_disable
)
2218 need_to_kill
= false;
2220 mem_cgroup_oom_notify(memcg
);
2221 spin_unlock(&memcg_oom_lock
);
2224 finish_wait(&memcg_oom_waitq
, &owait
.wait
);
2225 mem_cgroup_out_of_memory(memcg
, mask
, order
);
2228 finish_wait(&memcg_oom_waitq
, &owait
.wait
);
2230 spin_lock(&memcg_oom_lock
);
2232 mem_cgroup_oom_unlock(memcg
);
2233 memcg_wakeup_oom(memcg
);
2234 spin_unlock(&memcg_oom_lock
);
2236 mem_cgroup_unmark_under_oom(memcg
);
2238 if (test_thread_flag(TIF_MEMDIE
) || fatal_signal_pending(current
))
2240 /* Give chance to dying process */
2241 schedule_timeout_uninterruptible(1);
2246 * Currently used to update mapped file statistics, but the routine can be
2247 * generalized to update other statistics as well.
2249 * Notes: Race condition
2251 * We usually use page_cgroup_lock() for accessing page_cgroup member but
2252 * it tends to be costly. But considering some conditions, we doesn't need
2253 * to do so _always_.
2255 * Considering "charge", lock_page_cgroup() is not required because all
2256 * file-stat operations happen after a page is attached to radix-tree. There
2257 * are no race with "charge".
2259 * Considering "uncharge", we know that memcg doesn't clear pc->mem_cgroup
2260 * at "uncharge" intentionally. So, we always see valid pc->mem_cgroup even
2261 * if there are race with "uncharge". Statistics itself is properly handled
2264 * Considering "move", this is an only case we see a race. To make the race
2265 * small, we check mm->moving_account and detect there are possibility of race
2266 * If there is, we take a lock.
2269 void __mem_cgroup_begin_update_page_stat(struct page
*page
,
2270 bool *locked
, unsigned long *flags
)
2272 struct mem_cgroup
*memcg
;
2273 struct page_cgroup
*pc
;
2275 pc
= lookup_page_cgroup(page
);
2277 memcg
= pc
->mem_cgroup
;
2278 if (unlikely(!memcg
|| !PageCgroupUsed(pc
)))
2281 * If this memory cgroup is not under account moving, we don't
2282 * need to take move_lock_mem_cgroup(). Because we already hold
2283 * rcu_read_lock(), any calls to move_account will be delayed until
2284 * rcu_read_unlock() if mem_cgroup_stolen() == true.
2286 if (!mem_cgroup_stolen(memcg
))
2289 move_lock_mem_cgroup(memcg
, flags
);
2290 if (memcg
!= pc
->mem_cgroup
|| !PageCgroupUsed(pc
)) {
2291 move_unlock_mem_cgroup(memcg
, flags
);
2297 void __mem_cgroup_end_update_page_stat(struct page
*page
, unsigned long *flags
)
2299 struct page_cgroup
*pc
= lookup_page_cgroup(page
);
2302 * It's guaranteed that pc->mem_cgroup never changes while
2303 * lock is held because a routine modifies pc->mem_cgroup
2304 * should take move_lock_mem_cgroup().
2306 move_unlock_mem_cgroup(pc
->mem_cgroup
, flags
);
2309 void mem_cgroup_update_page_stat(struct page
*page
,
2310 enum mem_cgroup_page_stat_item idx
, int val
)
2312 struct mem_cgroup
*memcg
;
2313 struct page_cgroup
*pc
= lookup_page_cgroup(page
);
2314 unsigned long uninitialized_var(flags
);
2316 if (mem_cgroup_disabled())
2319 memcg
= pc
->mem_cgroup
;
2320 if (unlikely(!memcg
|| !PageCgroupUsed(pc
)))
2324 case MEMCG_NR_FILE_MAPPED
:
2325 idx
= MEM_CGROUP_STAT_FILE_MAPPED
;
2331 this_cpu_add(memcg
->stat
->count
[idx
], val
);
2335 * size of first charge trial. "32" comes from vmscan.c's magic value.
2336 * TODO: maybe necessary to use big numbers in big irons.
2338 #define CHARGE_BATCH 32U
2339 struct memcg_stock_pcp
{
2340 struct mem_cgroup
*cached
; /* this never be root cgroup */
2341 unsigned int nr_pages
;
2342 struct work_struct work
;
2343 unsigned long flags
;
2344 #define FLUSHING_CACHED_CHARGE 0
2346 static DEFINE_PER_CPU(struct memcg_stock_pcp
, memcg_stock
);
2347 static DEFINE_MUTEX(percpu_charge_mutex
);
2350 * consume_stock: Try to consume stocked charge on this cpu.
2351 * @memcg: memcg to consume from.
2352 * @nr_pages: how many pages to charge.
2354 * The charges will only happen if @memcg matches the current cpu's memcg
2355 * stock, and at least @nr_pages are available in that stock. Failure to
2356 * service an allocation will refill the stock.
2358 * returns true if successful, false otherwise.
2360 static bool consume_stock(struct mem_cgroup
*memcg
, unsigned int nr_pages
)
2362 struct memcg_stock_pcp
*stock
;
2365 if (nr_pages
> CHARGE_BATCH
)
2368 stock
= &get_cpu_var(memcg_stock
);
2369 if (memcg
== stock
->cached
&& stock
->nr_pages
>= nr_pages
)
2370 stock
->nr_pages
-= nr_pages
;
2371 else /* need to call res_counter_charge */
2373 put_cpu_var(memcg_stock
);
2378 * Returns stocks cached in percpu to res_counter and reset cached information.
2380 static void drain_stock(struct memcg_stock_pcp
*stock
)
2382 struct mem_cgroup
*old
= stock
->cached
;
2384 if (stock
->nr_pages
) {
2385 unsigned long bytes
= stock
->nr_pages
* PAGE_SIZE
;
2387 res_counter_uncharge(&old
->res
, bytes
);
2388 if (do_swap_account
)
2389 res_counter_uncharge(&old
->memsw
, bytes
);
2390 stock
->nr_pages
= 0;
2392 stock
->cached
= NULL
;
2396 * This must be called under preempt disabled or must be called by
2397 * a thread which is pinned to local cpu.
2399 static void drain_local_stock(struct work_struct
*dummy
)
2401 struct memcg_stock_pcp
*stock
= &__get_cpu_var(memcg_stock
);
2403 clear_bit(FLUSHING_CACHED_CHARGE
, &stock
->flags
);
2406 static void __init
memcg_stock_init(void)
2410 for_each_possible_cpu(cpu
) {
2411 struct memcg_stock_pcp
*stock
=
2412 &per_cpu(memcg_stock
, cpu
);
2413 INIT_WORK(&stock
->work
, drain_local_stock
);
2418 * Cache charges(val) which is from res_counter, to local per_cpu area.
2419 * This will be consumed by consume_stock() function, later.
2421 static void refill_stock(struct mem_cgroup
*memcg
, unsigned int nr_pages
)
2423 struct memcg_stock_pcp
*stock
= &get_cpu_var(memcg_stock
);
2425 if (stock
->cached
!= memcg
) { /* reset if necessary */
2427 stock
->cached
= memcg
;
2429 stock
->nr_pages
+= nr_pages
;
2430 put_cpu_var(memcg_stock
);
2434 * Drains all per-CPU charge caches for given root_memcg resp. subtree
2435 * of the hierarchy under it. sync flag says whether we should block
2436 * until the work is done.
2438 static void drain_all_stock(struct mem_cgroup
*root_memcg
, bool sync
)
2442 /* Notify other cpus that system-wide "drain" is running */
2445 for_each_online_cpu(cpu
) {
2446 struct memcg_stock_pcp
*stock
= &per_cpu(memcg_stock
, cpu
);
2447 struct mem_cgroup
*memcg
;
2449 memcg
= stock
->cached
;
2450 if (!memcg
|| !stock
->nr_pages
)
2452 if (!mem_cgroup_same_or_subtree(root_memcg
, memcg
))
2454 if (!test_and_set_bit(FLUSHING_CACHED_CHARGE
, &stock
->flags
)) {
2456 drain_local_stock(&stock
->work
);
2458 schedule_work_on(cpu
, &stock
->work
);
2466 for_each_online_cpu(cpu
) {
2467 struct memcg_stock_pcp
*stock
= &per_cpu(memcg_stock
, cpu
);
2468 if (test_bit(FLUSHING_CACHED_CHARGE
, &stock
->flags
))
2469 flush_work(&stock
->work
);
2476 * Tries to drain stocked charges in other cpus. This function is asynchronous
2477 * and just put a work per cpu for draining localy on each cpu. Caller can
2478 * expects some charges will be back to res_counter later but cannot wait for
2481 static void drain_all_stock_async(struct mem_cgroup
*root_memcg
)
2484 * If someone calls draining, avoid adding more kworker runs.
2486 if (!mutex_trylock(&percpu_charge_mutex
))
2488 drain_all_stock(root_memcg
, false);
2489 mutex_unlock(&percpu_charge_mutex
);
2492 /* This is a synchronous drain interface. */
2493 static void drain_all_stock_sync(struct mem_cgroup
*root_memcg
)
2495 /* called when force_empty is called */
2496 mutex_lock(&percpu_charge_mutex
);
2497 drain_all_stock(root_memcg
, true);
2498 mutex_unlock(&percpu_charge_mutex
);
2502 * This function drains percpu counter value from DEAD cpu and
2503 * move it to local cpu. Note that this function can be preempted.
2505 static void mem_cgroup_drain_pcp_counter(struct mem_cgroup
*memcg
, int cpu
)
2509 spin_lock(&memcg
->pcp_counter_lock
);
2510 for (i
= 0; i
< MEM_CGROUP_STAT_NSTATS
; i
++) {
2511 long x
= per_cpu(memcg
->stat
->count
[i
], cpu
);
2513 per_cpu(memcg
->stat
->count
[i
], cpu
) = 0;
2514 memcg
->nocpu_base
.count
[i
] += x
;
2516 for (i
= 0; i
< MEM_CGROUP_EVENTS_NSTATS
; i
++) {
2517 unsigned long x
= per_cpu(memcg
->stat
->events
[i
], cpu
);
2519 per_cpu(memcg
->stat
->events
[i
], cpu
) = 0;
2520 memcg
->nocpu_base
.events
[i
] += x
;
2522 spin_unlock(&memcg
->pcp_counter_lock
);
2525 static int __cpuinit
memcg_cpu_hotplug_callback(struct notifier_block
*nb
,
2526 unsigned long action
,
2529 int cpu
= (unsigned long)hcpu
;
2530 struct memcg_stock_pcp
*stock
;
2531 struct mem_cgroup
*iter
;
2533 if (action
== CPU_ONLINE
)
2536 if (action
!= CPU_DEAD
&& action
!= CPU_DEAD_FROZEN
)
2539 for_each_mem_cgroup(iter
)
2540 mem_cgroup_drain_pcp_counter(iter
, cpu
);
2542 stock
= &per_cpu(memcg_stock
, cpu
);
2548 /* See __mem_cgroup_try_charge() for details */
2550 CHARGE_OK
, /* success */
2551 CHARGE_RETRY
, /* need to retry but retry is not bad */
2552 CHARGE_NOMEM
, /* we can't do more. return -ENOMEM */
2553 CHARGE_WOULDBLOCK
, /* GFP_WAIT wasn't set and no enough res. */
2554 CHARGE_OOM_DIE
, /* the current is killed because of OOM */
2557 static int mem_cgroup_do_charge(struct mem_cgroup
*memcg
, gfp_t gfp_mask
,
2558 unsigned int nr_pages
, unsigned int min_pages
,
2561 unsigned long csize
= nr_pages
* PAGE_SIZE
;
2562 struct mem_cgroup
*mem_over_limit
;
2563 struct res_counter
*fail_res
;
2564 unsigned long flags
= 0;
2567 ret
= res_counter_charge(&memcg
->res
, csize
, &fail_res
);
2570 if (!do_swap_account
)
2572 ret
= res_counter_charge(&memcg
->memsw
, csize
, &fail_res
);
2576 res_counter_uncharge(&memcg
->res
, csize
);
2577 mem_over_limit
= mem_cgroup_from_res_counter(fail_res
, memsw
);
2578 flags
|= MEM_CGROUP_RECLAIM_NOSWAP
;
2580 mem_over_limit
= mem_cgroup_from_res_counter(fail_res
, res
);
2582 * Never reclaim on behalf of optional batching, retry with a
2583 * single page instead.
2585 if (nr_pages
> min_pages
)
2586 return CHARGE_RETRY
;
2588 if (!(gfp_mask
& __GFP_WAIT
))
2589 return CHARGE_WOULDBLOCK
;
2591 if (gfp_mask
& __GFP_NORETRY
)
2592 return CHARGE_NOMEM
;
2594 ret
= mem_cgroup_reclaim(mem_over_limit
, gfp_mask
, flags
);
2595 if (mem_cgroup_margin(mem_over_limit
) >= nr_pages
)
2596 return CHARGE_RETRY
;
2598 * Even though the limit is exceeded at this point, reclaim
2599 * may have been able to free some pages. Retry the charge
2600 * before killing the task.
2602 * Only for regular pages, though: huge pages are rather
2603 * unlikely to succeed so close to the limit, and we fall back
2604 * to regular pages anyway in case of failure.
2606 if (nr_pages
<= (1 << PAGE_ALLOC_COSTLY_ORDER
) && ret
)
2607 return CHARGE_RETRY
;
2610 * At task move, charge accounts can be doubly counted. So, it's
2611 * better to wait until the end of task_move if something is going on.
2613 if (mem_cgroup_wait_acct_move(mem_over_limit
))
2614 return CHARGE_RETRY
;
2616 /* If we don't need to call oom-killer at el, return immediately */
2618 return CHARGE_NOMEM
;
2620 if (!mem_cgroup_handle_oom(mem_over_limit
, gfp_mask
, get_order(csize
)))
2621 return CHARGE_OOM_DIE
;
2623 return CHARGE_RETRY
;
2627 * __mem_cgroup_try_charge() does
2628 * 1. detect memcg to be charged against from passed *mm and *ptr,
2629 * 2. update res_counter
2630 * 3. call memory reclaim if necessary.
2632 * In some special case, if the task is fatal, fatal_signal_pending() or
2633 * has TIF_MEMDIE, this function returns -EINTR while writing root_mem_cgroup
2634 * to *ptr. There are two reasons for this. 1: fatal threads should quit as soon
2635 * as possible without any hazards. 2: all pages should have a valid
2636 * pc->mem_cgroup. If mm is NULL and the caller doesn't pass a valid memcg
2637 * pointer, that is treated as a charge to root_mem_cgroup.
2639 * So __mem_cgroup_try_charge() will return
2640 * 0 ... on success, filling *ptr with a valid memcg pointer.
2641 * -ENOMEM ... charge failure because of resource limits.
2642 * -EINTR ... if thread is fatal. *ptr is filled with root_mem_cgroup.
2644 * Unlike the exported interface, an "oom" parameter is added. if oom==true,
2645 * the oom-killer can be invoked.
2647 static int __mem_cgroup_try_charge(struct mm_struct
*mm
,
2649 unsigned int nr_pages
,
2650 struct mem_cgroup
**ptr
,
2653 unsigned int batch
= max(CHARGE_BATCH
, nr_pages
);
2654 int nr_oom_retries
= MEM_CGROUP_RECLAIM_RETRIES
;
2655 struct mem_cgroup
*memcg
= NULL
;
2659 * Unlike gloval-vm's OOM-kill, we're not in memory shortage
2660 * in system level. So, allow to go ahead dying process in addition to
2663 if (unlikely(test_thread_flag(TIF_MEMDIE
)
2664 || fatal_signal_pending(current
)))
2668 * We always charge the cgroup the mm_struct belongs to.
2669 * The mm_struct's mem_cgroup changes on task migration if the
2670 * thread group leader migrates. It's possible that mm is not
2671 * set, if so charge the root memcg (happens for pagecache usage).
2674 *ptr
= root_mem_cgroup
;
2676 if (*ptr
) { /* css should be a valid one */
2678 if (mem_cgroup_is_root(memcg
))
2680 if (consume_stock(memcg
, nr_pages
))
2682 css_get(&memcg
->css
);
2684 struct task_struct
*p
;
2687 p
= rcu_dereference(mm
->owner
);
2689 * Because we don't have task_lock(), "p" can exit.
2690 * In that case, "memcg" can point to root or p can be NULL with
2691 * race with swapoff. Then, we have small risk of mis-accouning.
2692 * But such kind of mis-account by race always happens because
2693 * we don't have cgroup_mutex(). It's overkill and we allo that
2695 * (*) swapoff at el will charge against mm-struct not against
2696 * task-struct. So, mm->owner can be NULL.
2698 memcg
= mem_cgroup_from_task(p
);
2700 memcg
= root_mem_cgroup
;
2701 if (mem_cgroup_is_root(memcg
)) {
2705 if (consume_stock(memcg
, nr_pages
)) {
2707 * It seems dagerous to access memcg without css_get().
2708 * But considering how consume_stok works, it's not
2709 * necessary. If consume_stock success, some charges
2710 * from this memcg are cached on this cpu. So, we
2711 * don't need to call css_get()/css_tryget() before
2712 * calling consume_stock().
2717 /* after here, we may be blocked. we need to get refcnt */
2718 if (!css_tryget(&memcg
->css
)) {
2728 /* If killed, bypass charge */
2729 if (fatal_signal_pending(current
)) {
2730 css_put(&memcg
->css
);
2735 if (oom
&& !nr_oom_retries
) {
2737 nr_oom_retries
= MEM_CGROUP_RECLAIM_RETRIES
;
2740 ret
= mem_cgroup_do_charge(memcg
, gfp_mask
, batch
, nr_pages
,
2745 case CHARGE_RETRY
: /* not in OOM situation but retry */
2747 css_put(&memcg
->css
);
2750 case CHARGE_WOULDBLOCK
: /* !__GFP_WAIT */
2751 css_put(&memcg
->css
);
2753 case CHARGE_NOMEM
: /* OOM routine works */
2755 css_put(&memcg
->css
);
2758 /* If oom, we never return -ENOMEM */
2761 case CHARGE_OOM_DIE
: /* Killed by OOM Killer */
2762 css_put(&memcg
->css
);
2765 } while (ret
!= CHARGE_OK
);
2767 if (batch
> nr_pages
)
2768 refill_stock(memcg
, batch
- nr_pages
);
2769 css_put(&memcg
->css
);
2777 *ptr
= root_mem_cgroup
;
2782 * Somemtimes we have to undo a charge we got by try_charge().
2783 * This function is for that and do uncharge, put css's refcnt.
2784 * gotten by try_charge().
2786 static void __mem_cgroup_cancel_charge(struct mem_cgroup
*memcg
,
2787 unsigned int nr_pages
)
2789 if (!mem_cgroup_is_root(memcg
)) {
2790 unsigned long bytes
= nr_pages
* PAGE_SIZE
;
2792 res_counter_uncharge(&memcg
->res
, bytes
);
2793 if (do_swap_account
)
2794 res_counter_uncharge(&memcg
->memsw
, bytes
);
2799 * Cancel chrages in this cgroup....doesn't propagate to parent cgroup.
2800 * This is useful when moving usage to parent cgroup.
2802 static void __mem_cgroup_cancel_local_charge(struct mem_cgroup
*memcg
,
2803 unsigned int nr_pages
)
2805 unsigned long bytes
= nr_pages
* PAGE_SIZE
;
2807 if (mem_cgroup_is_root(memcg
))
2810 res_counter_uncharge_until(&memcg
->res
, memcg
->res
.parent
, bytes
);
2811 if (do_swap_account
)
2812 res_counter_uncharge_until(&memcg
->memsw
,
2813 memcg
->memsw
.parent
, bytes
);
2817 * A helper function to get mem_cgroup from ID. must be called under
2818 * rcu_read_lock(). The caller is responsible for calling css_tryget if
2819 * the mem_cgroup is used for charging. (dropping refcnt from swap can be
2820 * called against removed memcg.)
2822 static struct mem_cgroup
*mem_cgroup_lookup(unsigned short id
)
2824 struct cgroup_subsys_state
*css
;
2826 /* ID 0 is unused ID */
2829 css
= css_lookup(&mem_cgroup_subsys
, id
);
2832 return mem_cgroup_from_css(css
);
2835 struct mem_cgroup
*try_get_mem_cgroup_from_page(struct page
*page
)
2837 struct mem_cgroup
*memcg
= NULL
;
2838 struct page_cgroup
*pc
;
2842 VM_BUG_ON(!PageLocked(page
));
2844 pc
= lookup_page_cgroup(page
);
2845 lock_page_cgroup(pc
);
2846 if (PageCgroupUsed(pc
)) {
2847 memcg
= pc
->mem_cgroup
;
2848 if (memcg
&& !css_tryget(&memcg
->css
))
2850 } else if (PageSwapCache(page
)) {
2851 ent
.val
= page_private(page
);
2852 id
= lookup_swap_cgroup_id(ent
);
2854 memcg
= mem_cgroup_lookup(id
);
2855 if (memcg
&& !css_tryget(&memcg
->css
))
2859 unlock_page_cgroup(pc
);
2863 static void __mem_cgroup_commit_charge(struct mem_cgroup
*memcg
,
2865 unsigned int nr_pages
,
2866 enum charge_type ctype
,
2869 struct page_cgroup
*pc
= lookup_page_cgroup(page
);
2870 struct zone
*uninitialized_var(zone
);
2871 struct lruvec
*lruvec
;
2872 bool was_on_lru
= false;
2875 lock_page_cgroup(pc
);
2876 VM_BUG_ON(PageCgroupUsed(pc
));
2878 * we don't need page_cgroup_lock about tail pages, becase they are not
2879 * accessed by any other context at this point.
2883 * In some cases, SwapCache and FUSE(splice_buf->radixtree), the page
2884 * may already be on some other mem_cgroup's LRU. Take care of it.
2887 zone
= page_zone(page
);
2888 spin_lock_irq(&zone
->lru_lock
);
2889 if (PageLRU(page
)) {
2890 lruvec
= mem_cgroup_zone_lruvec(zone
, pc
->mem_cgroup
);
2892 del_page_from_lru_list(page
, lruvec
, page_lru(page
));
2897 pc
->mem_cgroup
= memcg
;
2899 * We access a page_cgroup asynchronously without lock_page_cgroup().
2900 * Especially when a page_cgroup is taken from a page, pc->mem_cgroup
2901 * is accessed after testing USED bit. To make pc->mem_cgroup visible
2902 * before USED bit, we need memory barrier here.
2903 * See mem_cgroup_add_lru_list(), etc.
2906 SetPageCgroupUsed(pc
);
2910 lruvec
= mem_cgroup_zone_lruvec(zone
, pc
->mem_cgroup
);
2911 VM_BUG_ON(PageLRU(page
));
2913 add_page_to_lru_list(page
, lruvec
, page_lru(page
));
2915 spin_unlock_irq(&zone
->lru_lock
);
2918 if (ctype
== MEM_CGROUP_CHARGE_TYPE_ANON
)
2923 mem_cgroup_charge_statistics(memcg
, page
, anon
, nr_pages
);
2924 unlock_page_cgroup(pc
);
2927 * "charge_statistics" updated event counter. Then, check it.
2928 * Insert ancestor (and ancestor's ancestors), to softlimit RB-tree.
2929 * if they exceeds softlimit.
2931 memcg_check_events(memcg
, page
);
2934 static DEFINE_MUTEX(set_limit_mutex
);
2936 #ifdef CONFIG_MEMCG_KMEM
2937 static inline bool memcg_can_account_kmem(struct mem_cgroup
*memcg
)
2939 return !mem_cgroup_disabled() && !mem_cgroup_is_root(memcg
) &&
2940 (memcg
->kmem_account_flags
& KMEM_ACCOUNTED_MASK
);
2944 * This is a bit cumbersome, but it is rarely used and avoids a backpointer
2945 * in the memcg_cache_params struct.
2947 static struct kmem_cache
*memcg_params_to_cache(struct memcg_cache_params
*p
)
2949 struct kmem_cache
*cachep
;
2951 VM_BUG_ON(p
->is_root_cache
);
2952 cachep
= p
->root_cache
;
2953 return cachep
->memcg_params
->memcg_caches
[memcg_cache_id(p
->memcg
)];
2956 #ifdef CONFIG_SLABINFO
2957 static int mem_cgroup_slabinfo_read(struct cgroup
*cont
, struct cftype
*cft
,
2960 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cont
);
2961 struct memcg_cache_params
*params
;
2963 if (!memcg_can_account_kmem(memcg
))
2966 print_slabinfo_header(m
);
2968 mutex_lock(&memcg
->slab_caches_mutex
);
2969 list_for_each_entry(params
, &memcg
->memcg_slab_caches
, list
)
2970 cache_show(memcg_params_to_cache(params
), m
);
2971 mutex_unlock(&memcg
->slab_caches_mutex
);
2977 static int memcg_charge_kmem(struct mem_cgroup
*memcg
, gfp_t gfp
, u64 size
)
2979 struct res_counter
*fail_res
;
2980 struct mem_cgroup
*_memcg
;
2984 ret
= res_counter_charge(&memcg
->kmem
, size
, &fail_res
);
2989 * Conditions under which we can wait for the oom_killer. Those are
2990 * the same conditions tested by the core page allocator
2992 may_oom
= (gfp
& __GFP_FS
) && !(gfp
& __GFP_NORETRY
);
2995 ret
= __mem_cgroup_try_charge(NULL
, gfp
, size
>> PAGE_SHIFT
,
2998 if (ret
== -EINTR
) {
3000 * __mem_cgroup_try_charge() chosed to bypass to root due to
3001 * OOM kill or fatal signal. Since our only options are to
3002 * either fail the allocation or charge it to this cgroup, do
3003 * it as a temporary condition. But we can't fail. From a
3004 * kmem/slab perspective, the cache has already been selected,
3005 * by mem_cgroup_kmem_get_cache(), so it is too late to change
3008 * This condition will only trigger if the task entered
3009 * memcg_charge_kmem in a sane state, but was OOM-killed during
3010 * __mem_cgroup_try_charge() above. Tasks that were already
3011 * dying when the allocation triggers should have been already
3012 * directed to the root cgroup in memcontrol.h
3014 res_counter_charge_nofail(&memcg
->res
, size
, &fail_res
);
3015 if (do_swap_account
)
3016 res_counter_charge_nofail(&memcg
->memsw
, size
,
3020 res_counter_uncharge(&memcg
->kmem
, size
);
3025 static void memcg_uncharge_kmem(struct mem_cgroup
*memcg
, u64 size
)
3027 res_counter_uncharge(&memcg
->res
, size
);
3028 if (do_swap_account
)
3029 res_counter_uncharge(&memcg
->memsw
, size
);
3032 if (res_counter_uncharge(&memcg
->kmem
, size
))
3035 if (memcg_kmem_test_and_clear_dead(memcg
))
3036 mem_cgroup_put(memcg
);
3039 void memcg_cache_list_add(struct mem_cgroup
*memcg
, struct kmem_cache
*cachep
)
3044 mutex_lock(&memcg
->slab_caches_mutex
);
3045 list_add(&cachep
->memcg_params
->list
, &memcg
->memcg_slab_caches
);
3046 mutex_unlock(&memcg
->slab_caches_mutex
);
3050 * helper for acessing a memcg's index. It will be used as an index in the
3051 * child cache array in kmem_cache, and also to derive its name. This function
3052 * will return -1 when this is not a kmem-limited memcg.
3054 int memcg_cache_id(struct mem_cgroup
*memcg
)
3056 return memcg
? memcg
->kmemcg_id
: -1;
3060 * This ends up being protected by the set_limit mutex, during normal
3061 * operation, because that is its main call site.
3063 * But when we create a new cache, we can call this as well if its parent
3064 * is kmem-limited. That will have to hold set_limit_mutex as well.
3066 int memcg_update_cache_sizes(struct mem_cgroup
*memcg
)
3070 num
= ida_simple_get(&kmem_limited_groups
,
3071 0, MEMCG_CACHES_MAX_SIZE
, GFP_KERNEL
);
3075 * After this point, kmem_accounted (that we test atomically in
3076 * the beginning of this conditional), is no longer 0. This
3077 * guarantees only one process will set the following boolean
3078 * to true. We don't need test_and_set because we're protected
3079 * by the set_limit_mutex anyway.
3081 memcg_kmem_set_activated(memcg
);
3083 ret
= memcg_update_all_caches(num
+1);
3085 ida_simple_remove(&kmem_limited_groups
, num
);
3086 memcg_kmem_clear_activated(memcg
);
3090 memcg
->kmemcg_id
= num
;
3091 INIT_LIST_HEAD(&memcg
->memcg_slab_caches
);
3092 mutex_init(&memcg
->slab_caches_mutex
);
3096 static size_t memcg_caches_array_size(int num_groups
)
3099 if (num_groups
<= 0)
3102 size
= 2 * num_groups
;
3103 if (size
< MEMCG_CACHES_MIN_SIZE
)
3104 size
= MEMCG_CACHES_MIN_SIZE
;
3105 else if (size
> MEMCG_CACHES_MAX_SIZE
)
3106 size
= MEMCG_CACHES_MAX_SIZE
;
3112 * We should update the current array size iff all caches updates succeed. This
3113 * can only be done from the slab side. The slab mutex needs to be held when
3116 void memcg_update_array_size(int num
)
3118 if (num
> memcg_limited_groups_array_size
)
3119 memcg_limited_groups_array_size
= memcg_caches_array_size(num
);
3122 static void kmem_cache_destroy_work_func(struct work_struct
*w
);
3124 int memcg_update_cache_size(struct kmem_cache
*s
, int num_groups
)
3126 struct memcg_cache_params
*cur_params
= s
->memcg_params
;
3128 VM_BUG_ON(s
->memcg_params
&& !s
->memcg_params
->is_root_cache
);
3130 if (num_groups
> memcg_limited_groups_array_size
) {
3132 ssize_t size
= memcg_caches_array_size(num_groups
);
3134 size
*= sizeof(void *);
3135 size
+= sizeof(struct memcg_cache_params
);
3137 s
->memcg_params
= kzalloc(size
, GFP_KERNEL
);
3138 if (!s
->memcg_params
) {
3139 s
->memcg_params
= cur_params
;
3143 s
->memcg_params
->is_root_cache
= true;
3146 * There is the chance it will be bigger than
3147 * memcg_limited_groups_array_size, if we failed an allocation
3148 * in a cache, in which case all caches updated before it, will
3149 * have a bigger array.
3151 * But if that is the case, the data after
3152 * memcg_limited_groups_array_size is certainly unused
3154 for (i
= 0; i
< memcg_limited_groups_array_size
; i
++) {
3155 if (!cur_params
->memcg_caches
[i
])
3157 s
->memcg_params
->memcg_caches
[i
] =
3158 cur_params
->memcg_caches
[i
];
3162 * Ideally, we would wait until all caches succeed, and only
3163 * then free the old one. But this is not worth the extra
3164 * pointer per-cache we'd have to have for this.
3166 * It is not a big deal if some caches are left with a size
3167 * bigger than the others. And all updates will reset this
3175 int memcg_register_cache(struct mem_cgroup
*memcg
, struct kmem_cache
*s
,
3176 struct kmem_cache
*root_cache
)
3178 size_t size
= sizeof(struct memcg_cache_params
);
3180 if (!memcg_kmem_enabled())
3184 size
+= memcg_limited_groups_array_size
* sizeof(void *);
3186 s
->memcg_params
= kzalloc(size
, GFP_KERNEL
);
3187 if (!s
->memcg_params
)
3190 INIT_WORK(&s
->memcg_params
->destroy
,
3191 kmem_cache_destroy_work_func
);
3193 s
->memcg_params
->memcg
= memcg
;
3194 s
->memcg_params
->root_cache
= root_cache
;
3196 s
->memcg_params
->is_root_cache
= true;
3201 void memcg_release_cache(struct kmem_cache
*s
)
3203 struct kmem_cache
*root
;
3204 struct mem_cgroup
*memcg
;
3208 * This happens, for instance, when a root cache goes away before we
3211 if (!s
->memcg_params
)
3214 if (s
->memcg_params
->is_root_cache
)
3217 memcg
= s
->memcg_params
->memcg
;
3218 id
= memcg_cache_id(memcg
);
3220 root
= s
->memcg_params
->root_cache
;
3221 root
->memcg_params
->memcg_caches
[id
] = NULL
;
3223 mutex_lock(&memcg
->slab_caches_mutex
);
3224 list_del(&s
->memcg_params
->list
);
3225 mutex_unlock(&memcg
->slab_caches_mutex
);
3227 mem_cgroup_put(memcg
);
3229 kfree(s
->memcg_params
);
3233 * During the creation a new cache, we need to disable our accounting mechanism
3234 * altogether. This is true even if we are not creating, but rather just
3235 * enqueing new caches to be created.
3237 * This is because that process will trigger allocations; some visible, like
3238 * explicit kmallocs to auxiliary data structures, name strings and internal
3239 * cache structures; some well concealed, like INIT_WORK() that can allocate
3240 * objects during debug.
3242 * If any allocation happens during memcg_kmem_get_cache, we will recurse back
3243 * to it. This may not be a bounded recursion: since the first cache creation
3244 * failed to complete (waiting on the allocation), we'll just try to create the
3245 * cache again, failing at the same point.
3247 * memcg_kmem_get_cache is prepared to abort after seeing a positive count of
3248 * memcg_kmem_skip_account. So we enclose anything that might allocate memory
3249 * inside the following two functions.
3251 static inline void memcg_stop_kmem_account(void)
3253 VM_BUG_ON(!current
->mm
);
3254 current
->memcg_kmem_skip_account
++;
3257 static inline void memcg_resume_kmem_account(void)
3259 VM_BUG_ON(!current
->mm
);
3260 current
->memcg_kmem_skip_account
--;
3263 static void kmem_cache_destroy_work_func(struct work_struct
*w
)
3265 struct kmem_cache
*cachep
;
3266 struct memcg_cache_params
*p
;
3268 p
= container_of(w
, struct memcg_cache_params
, destroy
);
3270 cachep
= memcg_params_to_cache(p
);
3273 * If we get down to 0 after shrink, we could delete right away.
3274 * However, memcg_release_pages() already puts us back in the workqueue
3275 * in that case. If we proceed deleting, we'll get a dangling
3276 * reference, and removing the object from the workqueue in that case
3277 * is unnecessary complication. We are not a fast path.
3279 * Note that this case is fundamentally different from racing with
3280 * shrink_slab(): if memcg_cgroup_destroy_cache() is called in
3281 * kmem_cache_shrink, not only we would be reinserting a dead cache
3282 * into the queue, but doing so from inside the worker racing to
3285 * So if we aren't down to zero, we'll just schedule a worker and try
3288 if (atomic_read(&cachep
->memcg_params
->nr_pages
) != 0) {
3289 kmem_cache_shrink(cachep
);
3290 if (atomic_read(&cachep
->memcg_params
->nr_pages
) == 0)
3293 kmem_cache_destroy(cachep
);
3296 void mem_cgroup_destroy_cache(struct kmem_cache
*cachep
)
3298 if (!cachep
->memcg_params
->dead
)
3302 * There are many ways in which we can get here.
3304 * We can get to a memory-pressure situation while the delayed work is
3305 * still pending to run. The vmscan shrinkers can then release all
3306 * cache memory and get us to destruction. If this is the case, we'll
3307 * be executed twice, which is a bug (the second time will execute over
3308 * bogus data). In this case, cancelling the work should be fine.
3310 * But we can also get here from the worker itself, if
3311 * kmem_cache_shrink is enough to shake all the remaining objects and
3312 * get the page count to 0. In this case, we'll deadlock if we try to
3313 * cancel the work (the worker runs with an internal lock held, which
3314 * is the same lock we would hold for cancel_work_sync().)
3316 * Since we can't possibly know who got us here, just refrain from
3317 * running if there is already work pending
3319 if (work_pending(&cachep
->memcg_params
->destroy
))
3322 * We have to defer the actual destroying to a workqueue, because
3323 * we might currently be in a context that cannot sleep.
3325 schedule_work(&cachep
->memcg_params
->destroy
);
3329 * This lock protects updaters, not readers. We want readers to be as fast as
3330 * they can, and they will either see NULL or a valid cache value. Our model
3331 * allow them to see NULL, in which case the root memcg will be selected.
3333 * We need this lock because multiple allocations to the same cache from a non
3334 * will span more than one worker. Only one of them can create the cache.
3336 static DEFINE_MUTEX(memcg_cache_mutex
);
3339 * Called with memcg_cache_mutex held
3341 static struct kmem_cache
*kmem_cache_dup(struct mem_cgroup
*memcg
,
3342 struct kmem_cache
*s
)
3344 struct kmem_cache
*new;
3345 static char *tmp_name
= NULL
;
3347 lockdep_assert_held(&memcg_cache_mutex
);
3350 * kmem_cache_create_memcg duplicates the given name and
3351 * cgroup_name for this name requires RCU context.
3352 * This static temporary buffer is used to prevent from
3353 * pointless shortliving allocation.
3356 tmp_name
= kmalloc(PATH_MAX
, GFP_KERNEL
);
3362 snprintf(tmp_name
, PATH_MAX
, "%s(%d:%s)", s
->name
,
3363 memcg_cache_id(memcg
), cgroup_name(memcg
->css
.cgroup
));
3366 new = kmem_cache_create_memcg(memcg
, tmp_name
, s
->object_size
, s
->align
,
3367 (s
->flags
& ~SLAB_PANIC
), s
->ctor
, s
);
3370 new->allocflags
|= __GFP_KMEMCG
;
3375 static struct kmem_cache
*memcg_create_kmem_cache(struct mem_cgroup
*memcg
,
3376 struct kmem_cache
*cachep
)
3378 struct kmem_cache
*new_cachep
;
3381 BUG_ON(!memcg_can_account_kmem(memcg
));
3383 idx
= memcg_cache_id(memcg
);
3385 mutex_lock(&memcg_cache_mutex
);
3386 new_cachep
= cachep
->memcg_params
->memcg_caches
[idx
];
3390 new_cachep
= kmem_cache_dup(memcg
, cachep
);
3391 if (new_cachep
== NULL
) {
3392 new_cachep
= cachep
;
3396 mem_cgroup_get(memcg
);
3397 atomic_set(&new_cachep
->memcg_params
->nr_pages
, 0);
3399 cachep
->memcg_params
->memcg_caches
[idx
] = new_cachep
;
3401 * the readers won't lock, make sure everybody sees the updated value,
3402 * so they won't put stuff in the queue again for no reason
3406 mutex_unlock(&memcg_cache_mutex
);
3410 void kmem_cache_destroy_memcg_children(struct kmem_cache
*s
)
3412 struct kmem_cache
*c
;
3415 if (!s
->memcg_params
)
3417 if (!s
->memcg_params
->is_root_cache
)
3421 * If the cache is being destroyed, we trust that there is no one else
3422 * requesting objects from it. Even if there are, the sanity checks in
3423 * kmem_cache_destroy should caught this ill-case.
3425 * Still, we don't want anyone else freeing memcg_caches under our
3426 * noses, which can happen if a new memcg comes to life. As usual,
3427 * we'll take the set_limit_mutex to protect ourselves against this.
3429 mutex_lock(&set_limit_mutex
);
3430 for (i
= 0; i
< memcg_limited_groups_array_size
; i
++) {
3431 c
= s
->memcg_params
->memcg_caches
[i
];
3436 * We will now manually delete the caches, so to avoid races
3437 * we need to cancel all pending destruction workers and
3438 * proceed with destruction ourselves.
3440 * kmem_cache_destroy() will call kmem_cache_shrink internally,
3441 * and that could spawn the workers again: it is likely that
3442 * the cache still have active pages until this very moment.
3443 * This would lead us back to mem_cgroup_destroy_cache.
3445 * But that will not execute at all if the "dead" flag is not
3446 * set, so flip it down to guarantee we are in control.
3448 c
->memcg_params
->dead
= false;
3449 cancel_work_sync(&c
->memcg_params
->destroy
);
3450 kmem_cache_destroy(c
);
3452 mutex_unlock(&set_limit_mutex
);
3455 struct create_work
{
3456 struct mem_cgroup
*memcg
;
3457 struct kmem_cache
*cachep
;
3458 struct work_struct work
;
3461 static void mem_cgroup_destroy_all_caches(struct mem_cgroup
*memcg
)
3463 struct kmem_cache
*cachep
;
3464 struct memcg_cache_params
*params
;
3466 if (!memcg_kmem_is_active(memcg
))
3469 mutex_lock(&memcg
->slab_caches_mutex
);
3470 list_for_each_entry(params
, &memcg
->memcg_slab_caches
, list
) {
3471 cachep
= memcg_params_to_cache(params
);
3472 cachep
->memcg_params
->dead
= true;
3473 schedule_work(&cachep
->memcg_params
->destroy
);
3475 mutex_unlock(&memcg
->slab_caches_mutex
);
3478 static void memcg_create_cache_work_func(struct work_struct
*w
)
3480 struct create_work
*cw
;
3482 cw
= container_of(w
, struct create_work
, work
);
3483 memcg_create_kmem_cache(cw
->memcg
, cw
->cachep
);
3484 /* Drop the reference gotten when we enqueued. */
3485 css_put(&cw
->memcg
->css
);
3490 * Enqueue the creation of a per-memcg kmem_cache.
3492 static void __memcg_create_cache_enqueue(struct mem_cgroup
*memcg
,
3493 struct kmem_cache
*cachep
)
3495 struct create_work
*cw
;
3497 cw
= kmalloc(sizeof(struct create_work
), GFP_NOWAIT
);
3499 css_put(&memcg
->css
);
3504 cw
->cachep
= cachep
;
3506 INIT_WORK(&cw
->work
, memcg_create_cache_work_func
);
3507 schedule_work(&cw
->work
);
3510 static void memcg_create_cache_enqueue(struct mem_cgroup
*memcg
,
3511 struct kmem_cache
*cachep
)
3514 * We need to stop accounting when we kmalloc, because if the
3515 * corresponding kmalloc cache is not yet created, the first allocation
3516 * in __memcg_create_cache_enqueue will recurse.
3518 * However, it is better to enclose the whole function. Depending on
3519 * the debugging options enabled, INIT_WORK(), for instance, can
3520 * trigger an allocation. This too, will make us recurse. Because at
3521 * this point we can't allow ourselves back into memcg_kmem_get_cache,
3522 * the safest choice is to do it like this, wrapping the whole function.
3524 memcg_stop_kmem_account();
3525 __memcg_create_cache_enqueue(memcg
, cachep
);
3526 memcg_resume_kmem_account();
3529 * Return the kmem_cache we're supposed to use for a slab allocation.
3530 * We try to use the current memcg's version of the cache.
3532 * If the cache does not exist yet, if we are the first user of it,
3533 * we either create it immediately, if possible, or create it asynchronously
3535 * In the latter case, we will let the current allocation go through with
3536 * the original cache.
3538 * Can't be called in interrupt context or from kernel threads.
3539 * This function needs to be called with rcu_read_lock() held.
3541 struct kmem_cache
*__memcg_kmem_get_cache(struct kmem_cache
*cachep
,
3544 struct mem_cgroup
*memcg
;
3547 VM_BUG_ON(!cachep
->memcg_params
);
3548 VM_BUG_ON(!cachep
->memcg_params
->is_root_cache
);
3550 if (!current
->mm
|| current
->memcg_kmem_skip_account
)
3554 memcg
= mem_cgroup_from_task(rcu_dereference(current
->mm
->owner
));
3556 if (!memcg_can_account_kmem(memcg
))
3559 idx
= memcg_cache_id(memcg
);
3562 * barrier to mare sure we're always seeing the up to date value. The
3563 * code updating memcg_caches will issue a write barrier to match this.
3565 read_barrier_depends();
3566 if (likely(cachep
->memcg_params
->memcg_caches
[idx
])) {
3567 cachep
= cachep
->memcg_params
->memcg_caches
[idx
];
3571 /* The corresponding put will be done in the workqueue. */
3572 if (!css_tryget(&memcg
->css
))
3577 * If we are in a safe context (can wait, and not in interrupt
3578 * context), we could be be predictable and return right away.
3579 * This would guarantee that the allocation being performed
3580 * already belongs in the new cache.
3582 * However, there are some clashes that can arrive from locking.
3583 * For instance, because we acquire the slab_mutex while doing
3584 * kmem_cache_dup, this means no further allocation could happen
3585 * with the slab_mutex held.
3587 * Also, because cache creation issue get_online_cpus(), this
3588 * creates a lock chain: memcg_slab_mutex -> cpu_hotplug_mutex,
3589 * that ends up reversed during cpu hotplug. (cpuset allocates
3590 * a bunch of GFP_KERNEL memory during cpuup). Due to all that,
3591 * better to defer everything.
3593 memcg_create_cache_enqueue(memcg
, cachep
);
3599 EXPORT_SYMBOL(__memcg_kmem_get_cache
);
3602 * We need to verify if the allocation against current->mm->owner's memcg is
3603 * possible for the given order. But the page is not allocated yet, so we'll
3604 * need a further commit step to do the final arrangements.
3606 * It is possible for the task to switch cgroups in this mean time, so at
3607 * commit time, we can't rely on task conversion any longer. We'll then use
3608 * the handle argument to return to the caller which cgroup we should commit
3609 * against. We could also return the memcg directly and avoid the pointer
3610 * passing, but a boolean return value gives better semantics considering
3611 * the compiled-out case as well.
3613 * Returning true means the allocation is possible.
3616 __memcg_kmem_newpage_charge(gfp_t gfp
, struct mem_cgroup
**_memcg
, int order
)
3618 struct mem_cgroup
*memcg
;
3622 memcg
= try_get_mem_cgroup_from_mm(current
->mm
);
3625 * very rare case described in mem_cgroup_from_task. Unfortunately there
3626 * isn't much we can do without complicating this too much, and it would
3627 * be gfp-dependent anyway. Just let it go
3629 if (unlikely(!memcg
))
3632 if (!memcg_can_account_kmem(memcg
)) {
3633 css_put(&memcg
->css
);
3637 ret
= memcg_charge_kmem(memcg
, gfp
, PAGE_SIZE
<< order
);
3641 css_put(&memcg
->css
);
3645 void __memcg_kmem_commit_charge(struct page
*page
, struct mem_cgroup
*memcg
,
3648 struct page_cgroup
*pc
;
3650 VM_BUG_ON(mem_cgroup_is_root(memcg
));
3652 /* The page allocation failed. Revert */
3654 memcg_uncharge_kmem(memcg
, PAGE_SIZE
<< order
);
3658 pc
= lookup_page_cgroup(page
);
3659 lock_page_cgroup(pc
);
3660 pc
->mem_cgroup
= memcg
;
3661 SetPageCgroupUsed(pc
);
3662 unlock_page_cgroup(pc
);
3665 void __memcg_kmem_uncharge_pages(struct page
*page
, int order
)
3667 struct mem_cgroup
*memcg
= NULL
;
3668 struct page_cgroup
*pc
;
3671 pc
= lookup_page_cgroup(page
);
3673 * Fast unlocked return. Theoretically might have changed, have to
3674 * check again after locking.
3676 if (!PageCgroupUsed(pc
))
3679 lock_page_cgroup(pc
);
3680 if (PageCgroupUsed(pc
)) {
3681 memcg
= pc
->mem_cgroup
;
3682 ClearPageCgroupUsed(pc
);
3684 unlock_page_cgroup(pc
);
3687 * We trust that only if there is a memcg associated with the page, it
3688 * is a valid allocation
3693 VM_BUG_ON(mem_cgroup_is_root(memcg
));
3694 memcg_uncharge_kmem(memcg
, PAGE_SIZE
<< order
);
3697 static inline void mem_cgroup_destroy_all_caches(struct mem_cgroup
*memcg
)
3700 #endif /* CONFIG_MEMCG_KMEM */
3702 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
3704 #define PCGF_NOCOPY_AT_SPLIT (1 << PCG_LOCK | 1 << PCG_MIGRATION)
3706 * Because tail pages are not marked as "used", set it. We're under
3707 * zone->lru_lock, 'splitting on pmd' and compound_lock.
3708 * charge/uncharge will be never happen and move_account() is done under
3709 * compound_lock(), so we don't have to take care of races.
3711 void mem_cgroup_split_huge_fixup(struct page
*head
)
3713 struct page_cgroup
*head_pc
= lookup_page_cgroup(head
);
3714 struct page_cgroup
*pc
;
3715 struct mem_cgroup
*memcg
;
3718 if (mem_cgroup_disabled())
3721 memcg
= head_pc
->mem_cgroup
;
3722 for (i
= 1; i
< HPAGE_PMD_NR
; i
++) {
3724 pc
->mem_cgroup
= memcg
;
3725 smp_wmb();/* see __commit_charge() */
3726 pc
->flags
= head_pc
->flags
& ~PCGF_NOCOPY_AT_SPLIT
;
3728 __this_cpu_sub(memcg
->stat
->count
[MEM_CGROUP_STAT_RSS_HUGE
],
3731 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
3734 * mem_cgroup_move_account - move account of the page
3736 * @nr_pages: number of regular pages (>1 for huge pages)
3737 * @pc: page_cgroup of the page.
3738 * @from: mem_cgroup which the page is moved from.
3739 * @to: mem_cgroup which the page is moved to. @from != @to.
3741 * The caller must confirm following.
3742 * - page is not on LRU (isolate_page() is useful.)
3743 * - compound_lock is held when nr_pages > 1
3745 * This function doesn't do "charge" to new cgroup and doesn't do "uncharge"
3748 static int mem_cgroup_move_account(struct page
*page
,
3749 unsigned int nr_pages
,
3750 struct page_cgroup
*pc
,
3751 struct mem_cgroup
*from
,
3752 struct mem_cgroup
*to
)
3754 unsigned long flags
;
3756 bool anon
= PageAnon(page
);
3758 VM_BUG_ON(from
== to
);
3759 VM_BUG_ON(PageLRU(page
));
3761 * The page is isolated from LRU. So, collapse function
3762 * will not handle this page. But page splitting can happen.
3763 * Do this check under compound_page_lock(). The caller should
3767 if (nr_pages
> 1 && !PageTransHuge(page
))
3770 lock_page_cgroup(pc
);
3773 if (!PageCgroupUsed(pc
) || pc
->mem_cgroup
!= from
)
3776 move_lock_mem_cgroup(from
, &flags
);
3778 if (!anon
&& page_mapped(page
)) {
3779 /* Update mapped_file data for mem_cgroup */
3781 __this_cpu_dec(from
->stat
->count
[MEM_CGROUP_STAT_FILE_MAPPED
]);
3782 __this_cpu_inc(to
->stat
->count
[MEM_CGROUP_STAT_FILE_MAPPED
]);
3785 mem_cgroup_charge_statistics(from
, page
, anon
, -nr_pages
);
3787 /* caller should have done css_get */
3788 pc
->mem_cgroup
= to
;
3789 mem_cgroup_charge_statistics(to
, page
, anon
, nr_pages
);
3790 move_unlock_mem_cgroup(from
, &flags
);
3793 unlock_page_cgroup(pc
);
3797 memcg_check_events(to
, page
);
3798 memcg_check_events(from
, page
);
3804 * mem_cgroup_move_parent - moves page to the parent group
3805 * @page: the page to move
3806 * @pc: page_cgroup of the page
3807 * @child: page's cgroup
3809 * move charges to its parent or the root cgroup if the group has no
3810 * parent (aka use_hierarchy==0).
3811 * Although this might fail (get_page_unless_zero, isolate_lru_page or
3812 * mem_cgroup_move_account fails) the failure is always temporary and
3813 * it signals a race with a page removal/uncharge or migration. In the
3814 * first case the page is on the way out and it will vanish from the LRU
3815 * on the next attempt and the call should be retried later.
3816 * Isolation from the LRU fails only if page has been isolated from
3817 * the LRU since we looked at it and that usually means either global
3818 * reclaim or migration going on. The page will either get back to the
3820 * Finaly mem_cgroup_move_account fails only if the page got uncharged
3821 * (!PageCgroupUsed) or moved to a different group. The page will
3822 * disappear in the next attempt.
3824 static int mem_cgroup_move_parent(struct page
*page
,
3825 struct page_cgroup
*pc
,
3826 struct mem_cgroup
*child
)
3828 struct mem_cgroup
*parent
;
3829 unsigned int nr_pages
;
3830 unsigned long uninitialized_var(flags
);
3833 VM_BUG_ON(mem_cgroup_is_root(child
));
3836 if (!get_page_unless_zero(page
))
3838 if (isolate_lru_page(page
))
3841 nr_pages
= hpage_nr_pages(page
);
3843 parent
= parent_mem_cgroup(child
);
3845 * If no parent, move charges to root cgroup.
3848 parent
= root_mem_cgroup
;
3851 VM_BUG_ON(!PageTransHuge(page
));
3852 flags
= compound_lock_irqsave(page
);
3855 ret
= mem_cgroup_move_account(page
, nr_pages
,
3858 __mem_cgroup_cancel_local_charge(child
, nr_pages
);
3861 compound_unlock_irqrestore(page
, flags
);
3862 putback_lru_page(page
);
3870 * Charge the memory controller for page usage.
3872 * 0 if the charge was successful
3873 * < 0 if the cgroup is over its limit
3875 static int mem_cgroup_charge_common(struct page
*page
, struct mm_struct
*mm
,
3876 gfp_t gfp_mask
, enum charge_type ctype
)
3878 struct mem_cgroup
*memcg
= NULL
;
3879 unsigned int nr_pages
= 1;
3883 if (PageTransHuge(page
)) {
3884 nr_pages
<<= compound_order(page
);
3885 VM_BUG_ON(!PageTransHuge(page
));
3887 * Never OOM-kill a process for a huge page. The
3888 * fault handler will fall back to regular pages.
3893 ret
= __mem_cgroup_try_charge(mm
, gfp_mask
, nr_pages
, &memcg
, oom
);
3896 __mem_cgroup_commit_charge(memcg
, page
, nr_pages
, ctype
, false);
3900 int mem_cgroup_newpage_charge(struct page
*page
,
3901 struct mm_struct
*mm
, gfp_t gfp_mask
)
3903 if (mem_cgroup_disabled())
3905 VM_BUG_ON(page_mapped(page
));
3906 VM_BUG_ON(page
->mapping
&& !PageAnon(page
));
3908 return mem_cgroup_charge_common(page
, mm
, gfp_mask
,
3909 MEM_CGROUP_CHARGE_TYPE_ANON
);
3913 * While swap-in, try_charge -> commit or cancel, the page is locked.
3914 * And when try_charge() successfully returns, one refcnt to memcg without
3915 * struct page_cgroup is acquired. This refcnt will be consumed by
3916 * "commit()" or removed by "cancel()"
3918 static int __mem_cgroup_try_charge_swapin(struct mm_struct
*mm
,
3921 struct mem_cgroup
**memcgp
)
3923 struct mem_cgroup
*memcg
;
3924 struct page_cgroup
*pc
;
3927 pc
= lookup_page_cgroup(page
);
3929 * Every swap fault against a single page tries to charge the
3930 * page, bail as early as possible. shmem_unuse() encounters
3931 * already charged pages, too. The USED bit is protected by
3932 * the page lock, which serializes swap cache removal, which
3933 * in turn serializes uncharging.
3935 if (PageCgroupUsed(pc
))
3937 if (!do_swap_account
)
3939 memcg
= try_get_mem_cgroup_from_page(page
);
3943 ret
= __mem_cgroup_try_charge(NULL
, mask
, 1, memcgp
, true);
3944 css_put(&memcg
->css
);
3949 ret
= __mem_cgroup_try_charge(mm
, mask
, 1, memcgp
, true);
3955 int mem_cgroup_try_charge_swapin(struct mm_struct
*mm
, struct page
*page
,
3956 gfp_t gfp_mask
, struct mem_cgroup
**memcgp
)
3959 if (mem_cgroup_disabled())
3962 * A racing thread's fault, or swapoff, may have already
3963 * updated the pte, and even removed page from swap cache: in
3964 * those cases unuse_pte()'s pte_same() test will fail; but
3965 * there's also a KSM case which does need to charge the page.
3967 if (!PageSwapCache(page
)) {
3970 ret
= __mem_cgroup_try_charge(mm
, gfp_mask
, 1, memcgp
, true);
3975 return __mem_cgroup_try_charge_swapin(mm
, page
, gfp_mask
, memcgp
);
3978 void mem_cgroup_cancel_charge_swapin(struct mem_cgroup
*memcg
)
3980 if (mem_cgroup_disabled())
3984 __mem_cgroup_cancel_charge(memcg
, 1);
3988 __mem_cgroup_commit_charge_swapin(struct page
*page
, struct mem_cgroup
*memcg
,
3989 enum charge_type ctype
)
3991 if (mem_cgroup_disabled())
3996 __mem_cgroup_commit_charge(memcg
, page
, 1, ctype
, true);
3998 * Now swap is on-memory. This means this page may be
3999 * counted both as mem and swap....double count.
4000 * Fix it by uncharging from memsw. Basically, this SwapCache is stable
4001 * under lock_page(). But in do_swap_page()::memory.c, reuse_swap_page()
4002 * may call delete_from_swap_cache() before reach here.
4004 if (do_swap_account
&& PageSwapCache(page
)) {
4005 swp_entry_t ent
= {.val
= page_private(page
)};
4006 mem_cgroup_uncharge_swap(ent
);
4010 void mem_cgroup_commit_charge_swapin(struct page
*page
,
4011 struct mem_cgroup
*memcg
)
4013 __mem_cgroup_commit_charge_swapin(page
, memcg
,
4014 MEM_CGROUP_CHARGE_TYPE_ANON
);
4017 int mem_cgroup_cache_charge(struct page
*page
, struct mm_struct
*mm
,
4020 struct mem_cgroup
*memcg
= NULL
;
4021 enum charge_type type
= MEM_CGROUP_CHARGE_TYPE_CACHE
;
4024 if (mem_cgroup_disabled())
4026 if (PageCompound(page
))
4029 if (!PageSwapCache(page
))
4030 ret
= mem_cgroup_charge_common(page
, mm
, gfp_mask
, type
);
4031 else { /* page is swapcache/shmem */
4032 ret
= __mem_cgroup_try_charge_swapin(mm
, page
,
4035 __mem_cgroup_commit_charge_swapin(page
, memcg
, type
);
4040 static void mem_cgroup_do_uncharge(struct mem_cgroup
*memcg
,
4041 unsigned int nr_pages
,
4042 const enum charge_type ctype
)
4044 struct memcg_batch_info
*batch
= NULL
;
4045 bool uncharge_memsw
= true;
4047 /* If swapout, usage of swap doesn't decrease */
4048 if (!do_swap_account
|| ctype
== MEM_CGROUP_CHARGE_TYPE_SWAPOUT
)
4049 uncharge_memsw
= false;
4051 batch
= ¤t
->memcg_batch
;
4053 * In usual, we do css_get() when we remember memcg pointer.
4054 * But in this case, we keep res->usage until end of a series of
4055 * uncharges. Then, it's ok to ignore memcg's refcnt.
4058 batch
->memcg
= memcg
;
4060 * do_batch > 0 when unmapping pages or inode invalidate/truncate.
4061 * In those cases, all pages freed continuously can be expected to be in
4062 * the same cgroup and we have chance to coalesce uncharges.
4063 * But we do uncharge one by one if this is killed by OOM(TIF_MEMDIE)
4064 * because we want to do uncharge as soon as possible.
4067 if (!batch
->do_batch
|| test_thread_flag(TIF_MEMDIE
))
4068 goto direct_uncharge
;
4071 goto direct_uncharge
;
4074 * In typical case, batch->memcg == mem. This means we can
4075 * merge a series of uncharges to an uncharge of res_counter.
4076 * If not, we uncharge res_counter ony by one.
4078 if (batch
->memcg
!= memcg
)
4079 goto direct_uncharge
;
4080 /* remember freed charge and uncharge it later */
4083 batch
->memsw_nr_pages
++;
4086 res_counter_uncharge(&memcg
->res
, nr_pages
* PAGE_SIZE
);
4088 res_counter_uncharge(&memcg
->memsw
, nr_pages
* PAGE_SIZE
);
4089 if (unlikely(batch
->memcg
!= memcg
))
4090 memcg_oom_recover(memcg
);
4094 * uncharge if !page_mapped(page)
4096 static struct mem_cgroup
*
4097 __mem_cgroup_uncharge_common(struct page
*page
, enum charge_type ctype
,
4100 struct mem_cgroup
*memcg
= NULL
;
4101 unsigned int nr_pages
= 1;
4102 struct page_cgroup
*pc
;
4105 if (mem_cgroup_disabled())
4108 if (PageTransHuge(page
)) {
4109 nr_pages
<<= compound_order(page
);
4110 VM_BUG_ON(!PageTransHuge(page
));
4113 * Check if our page_cgroup is valid
4115 pc
= lookup_page_cgroup(page
);
4116 if (unlikely(!PageCgroupUsed(pc
)))
4119 lock_page_cgroup(pc
);
4121 memcg
= pc
->mem_cgroup
;
4123 if (!PageCgroupUsed(pc
))
4126 anon
= PageAnon(page
);
4129 case MEM_CGROUP_CHARGE_TYPE_ANON
:
4131 * Generally PageAnon tells if it's the anon statistics to be
4132 * updated; but sometimes e.g. mem_cgroup_uncharge_page() is
4133 * used before page reached the stage of being marked PageAnon.
4137 case MEM_CGROUP_CHARGE_TYPE_DROP
:
4138 /* See mem_cgroup_prepare_migration() */
4139 if (page_mapped(page
))
4142 * Pages under migration may not be uncharged. But
4143 * end_migration() /must/ be the one uncharging the
4144 * unused post-migration page and so it has to call
4145 * here with the migration bit still set. See the
4146 * res_counter handling below.
4148 if (!end_migration
&& PageCgroupMigration(pc
))
4151 case MEM_CGROUP_CHARGE_TYPE_SWAPOUT
:
4152 if (!PageAnon(page
)) { /* Shared memory */
4153 if (page
->mapping
&& !page_is_file_cache(page
))
4155 } else if (page_mapped(page
)) /* Anon */
4162 mem_cgroup_charge_statistics(memcg
, page
, anon
, -nr_pages
);
4164 ClearPageCgroupUsed(pc
);
4166 * pc->mem_cgroup is not cleared here. It will be accessed when it's
4167 * freed from LRU. This is safe because uncharged page is expected not
4168 * to be reused (freed soon). Exception is SwapCache, it's handled by
4169 * special functions.
4172 unlock_page_cgroup(pc
);
4174 * even after unlock, we have memcg->res.usage here and this memcg
4175 * will never be freed.
4177 memcg_check_events(memcg
, page
);
4178 if (do_swap_account
&& ctype
== MEM_CGROUP_CHARGE_TYPE_SWAPOUT
) {
4179 mem_cgroup_swap_statistics(memcg
, true);
4180 mem_cgroup_get(memcg
);
4183 * Migration does not charge the res_counter for the
4184 * replacement page, so leave it alone when phasing out the
4185 * page that is unused after the migration.
4187 if (!end_migration
&& !mem_cgroup_is_root(memcg
))
4188 mem_cgroup_do_uncharge(memcg
, nr_pages
, ctype
);
4193 unlock_page_cgroup(pc
);
4197 void mem_cgroup_uncharge_page(struct page
*page
)
4200 if (page_mapped(page
))
4202 VM_BUG_ON(page
->mapping
&& !PageAnon(page
));
4204 * If the page is in swap cache, uncharge should be deferred
4205 * to the swap path, which also properly accounts swap usage
4206 * and handles memcg lifetime.
4208 * Note that this check is not stable and reclaim may add the
4209 * page to swap cache at any time after this. However, if the
4210 * page is not in swap cache by the time page->mapcount hits
4211 * 0, there won't be any page table references to the swap
4212 * slot, and reclaim will free it and not actually write the
4215 if (PageSwapCache(page
))
4217 __mem_cgroup_uncharge_common(page
, MEM_CGROUP_CHARGE_TYPE_ANON
, false);
4220 void mem_cgroup_uncharge_cache_page(struct page
*page
)
4222 VM_BUG_ON(page_mapped(page
));
4223 VM_BUG_ON(page
->mapping
);
4224 __mem_cgroup_uncharge_common(page
, MEM_CGROUP_CHARGE_TYPE_CACHE
, false);
4228 * Batch_start/batch_end is called in unmap_page_range/invlidate/trucate.
4229 * In that cases, pages are freed continuously and we can expect pages
4230 * are in the same memcg. All these calls itself limits the number of
4231 * pages freed at once, then uncharge_start/end() is called properly.
4232 * This may be called prural(2) times in a context,
4235 void mem_cgroup_uncharge_start(void)
4237 current
->memcg_batch
.do_batch
++;
4238 /* We can do nest. */
4239 if (current
->memcg_batch
.do_batch
== 1) {
4240 current
->memcg_batch
.memcg
= NULL
;
4241 current
->memcg_batch
.nr_pages
= 0;
4242 current
->memcg_batch
.memsw_nr_pages
= 0;
4246 void mem_cgroup_uncharge_end(void)
4248 struct memcg_batch_info
*batch
= ¤t
->memcg_batch
;
4250 if (!batch
->do_batch
)
4254 if (batch
->do_batch
) /* If stacked, do nothing. */
4260 * This "batch->memcg" is valid without any css_get/put etc...
4261 * bacause we hide charges behind us.
4263 if (batch
->nr_pages
)
4264 res_counter_uncharge(&batch
->memcg
->res
,
4265 batch
->nr_pages
* PAGE_SIZE
);
4266 if (batch
->memsw_nr_pages
)
4267 res_counter_uncharge(&batch
->memcg
->memsw
,
4268 batch
->memsw_nr_pages
* PAGE_SIZE
);
4269 memcg_oom_recover(batch
->memcg
);
4270 /* forget this pointer (for sanity check) */
4271 batch
->memcg
= NULL
;
4276 * called after __delete_from_swap_cache() and drop "page" account.
4277 * memcg information is recorded to swap_cgroup of "ent"
4280 mem_cgroup_uncharge_swapcache(struct page
*page
, swp_entry_t ent
, bool swapout
)
4282 struct mem_cgroup
*memcg
;
4283 int ctype
= MEM_CGROUP_CHARGE_TYPE_SWAPOUT
;
4285 if (!swapout
) /* this was a swap cache but the swap is unused ! */
4286 ctype
= MEM_CGROUP_CHARGE_TYPE_DROP
;
4288 memcg
= __mem_cgroup_uncharge_common(page
, ctype
, false);
4291 * record memcg information, if swapout && memcg != NULL,
4292 * mem_cgroup_get() was called in uncharge().
4294 if (do_swap_account
&& swapout
&& memcg
)
4295 swap_cgroup_record(ent
, css_id(&memcg
->css
));
4299 #ifdef CONFIG_MEMCG_SWAP
4301 * called from swap_entry_free(). remove record in swap_cgroup and
4302 * uncharge "memsw" account.
4304 void mem_cgroup_uncharge_swap(swp_entry_t ent
)
4306 struct mem_cgroup
*memcg
;
4309 if (!do_swap_account
)
4312 id
= swap_cgroup_record(ent
, 0);
4314 memcg
= mem_cgroup_lookup(id
);
4317 * We uncharge this because swap is freed.
4318 * This memcg can be obsolete one. We avoid calling css_tryget
4320 if (!mem_cgroup_is_root(memcg
))
4321 res_counter_uncharge(&memcg
->memsw
, PAGE_SIZE
);
4322 mem_cgroup_swap_statistics(memcg
, false);
4323 mem_cgroup_put(memcg
);
4329 * mem_cgroup_move_swap_account - move swap charge and swap_cgroup's record.
4330 * @entry: swap entry to be moved
4331 * @from: mem_cgroup which the entry is moved from
4332 * @to: mem_cgroup which the entry is moved to
4334 * It succeeds only when the swap_cgroup's record for this entry is the same
4335 * as the mem_cgroup's id of @from.
4337 * Returns 0 on success, -EINVAL on failure.
4339 * The caller must have charged to @to, IOW, called res_counter_charge() about
4340 * both res and memsw, and called css_get().
4342 static int mem_cgroup_move_swap_account(swp_entry_t entry
,
4343 struct mem_cgroup
*from
, struct mem_cgroup
*to
)
4345 unsigned short old_id
, new_id
;
4347 old_id
= css_id(&from
->css
);
4348 new_id
= css_id(&to
->css
);
4350 if (swap_cgroup_cmpxchg(entry
, old_id
, new_id
) == old_id
) {
4351 mem_cgroup_swap_statistics(from
, false);
4352 mem_cgroup_swap_statistics(to
, true);
4354 * This function is only called from task migration context now.
4355 * It postpones res_counter and refcount handling till the end
4356 * of task migration(mem_cgroup_clear_mc()) for performance
4357 * improvement. But we cannot postpone mem_cgroup_get(to)
4358 * because if the process that has been moved to @to does
4359 * swap-in, the refcount of @to might be decreased to 0.
4367 static inline int mem_cgroup_move_swap_account(swp_entry_t entry
,
4368 struct mem_cgroup
*from
, struct mem_cgroup
*to
)
4375 * Before starting migration, account PAGE_SIZE to mem_cgroup that the old
4378 void mem_cgroup_prepare_migration(struct page
*page
, struct page
*newpage
,
4379 struct mem_cgroup
**memcgp
)
4381 struct mem_cgroup
*memcg
= NULL
;
4382 unsigned int nr_pages
= 1;
4383 struct page_cgroup
*pc
;
4384 enum charge_type ctype
;
4388 if (mem_cgroup_disabled())
4391 if (PageTransHuge(page
))
4392 nr_pages
<<= compound_order(page
);
4394 pc
= lookup_page_cgroup(page
);
4395 lock_page_cgroup(pc
);
4396 if (PageCgroupUsed(pc
)) {
4397 memcg
= pc
->mem_cgroup
;
4398 css_get(&memcg
->css
);
4400 * At migrating an anonymous page, its mapcount goes down
4401 * to 0 and uncharge() will be called. But, even if it's fully
4402 * unmapped, migration may fail and this page has to be
4403 * charged again. We set MIGRATION flag here and delay uncharge
4404 * until end_migration() is called
4406 * Corner Case Thinking
4408 * When the old page was mapped as Anon and it's unmap-and-freed
4409 * while migration was ongoing.
4410 * If unmap finds the old page, uncharge() of it will be delayed
4411 * until end_migration(). If unmap finds a new page, it's
4412 * uncharged when it make mapcount to be 1->0. If unmap code
4413 * finds swap_migration_entry, the new page will not be mapped
4414 * and end_migration() will find it(mapcount==0).
4417 * When the old page was mapped but migraion fails, the kernel
4418 * remaps it. A charge for it is kept by MIGRATION flag even
4419 * if mapcount goes down to 0. We can do remap successfully
4420 * without charging it again.
4423 * The "old" page is under lock_page() until the end of
4424 * migration, so, the old page itself will not be swapped-out.
4425 * If the new page is swapped out before end_migraton, our
4426 * hook to usual swap-out path will catch the event.
4429 SetPageCgroupMigration(pc
);
4431 unlock_page_cgroup(pc
);
4433 * If the page is not charged at this point,
4441 * We charge new page before it's used/mapped. So, even if unlock_page()
4442 * is called before end_migration, we can catch all events on this new
4443 * page. In the case new page is migrated but not remapped, new page's
4444 * mapcount will be finally 0 and we call uncharge in end_migration().
4447 ctype
= MEM_CGROUP_CHARGE_TYPE_ANON
;
4449 ctype
= MEM_CGROUP_CHARGE_TYPE_CACHE
;
4451 * The page is committed to the memcg, but it's not actually
4452 * charged to the res_counter since we plan on replacing the
4453 * old one and only one page is going to be left afterwards.
4455 __mem_cgroup_commit_charge(memcg
, newpage
, nr_pages
, ctype
, false);
4458 /* remove redundant charge if migration failed*/
4459 void mem_cgroup_end_migration(struct mem_cgroup
*memcg
,
4460 struct page
*oldpage
, struct page
*newpage
, bool migration_ok
)
4462 struct page
*used
, *unused
;
4463 struct page_cgroup
*pc
;
4469 if (!migration_ok
) {
4476 anon
= PageAnon(used
);
4477 __mem_cgroup_uncharge_common(unused
,
4478 anon
? MEM_CGROUP_CHARGE_TYPE_ANON
4479 : MEM_CGROUP_CHARGE_TYPE_CACHE
,
4481 css_put(&memcg
->css
);
4483 * We disallowed uncharge of pages under migration because mapcount
4484 * of the page goes down to zero, temporarly.
4485 * Clear the flag and check the page should be charged.
4487 pc
= lookup_page_cgroup(oldpage
);
4488 lock_page_cgroup(pc
);
4489 ClearPageCgroupMigration(pc
);
4490 unlock_page_cgroup(pc
);
4493 * If a page is a file cache, radix-tree replacement is very atomic
4494 * and we can skip this check. When it was an Anon page, its mapcount
4495 * goes down to 0. But because we added MIGRATION flage, it's not
4496 * uncharged yet. There are several case but page->mapcount check
4497 * and USED bit check in mem_cgroup_uncharge_page() will do enough
4498 * check. (see prepare_charge() also)
4501 mem_cgroup_uncharge_page(used
);
4505 * At replace page cache, newpage is not under any memcg but it's on
4506 * LRU. So, this function doesn't touch res_counter but handles LRU
4507 * in correct way. Both pages are locked so we cannot race with uncharge.
4509 void mem_cgroup_replace_page_cache(struct page
*oldpage
,
4510 struct page
*newpage
)
4512 struct mem_cgroup
*memcg
= NULL
;
4513 struct page_cgroup
*pc
;
4514 enum charge_type type
= MEM_CGROUP_CHARGE_TYPE_CACHE
;
4516 if (mem_cgroup_disabled())
4519 pc
= lookup_page_cgroup(oldpage
);
4520 /* fix accounting on old pages */
4521 lock_page_cgroup(pc
);
4522 if (PageCgroupUsed(pc
)) {
4523 memcg
= pc
->mem_cgroup
;
4524 mem_cgroup_charge_statistics(memcg
, oldpage
, false, -1);
4525 ClearPageCgroupUsed(pc
);
4527 unlock_page_cgroup(pc
);
4530 * When called from shmem_replace_page(), in some cases the
4531 * oldpage has already been charged, and in some cases not.
4536 * Even if newpage->mapping was NULL before starting replacement,
4537 * the newpage may be on LRU(or pagevec for LRU) already. We lock
4538 * LRU while we overwrite pc->mem_cgroup.
4540 __mem_cgroup_commit_charge(memcg
, newpage
, 1, type
, true);
4543 #ifdef CONFIG_DEBUG_VM
4544 static struct page_cgroup
*lookup_page_cgroup_used(struct page
*page
)
4546 struct page_cgroup
*pc
;
4548 pc
= lookup_page_cgroup(page
);
4550 * Can be NULL while feeding pages into the page allocator for
4551 * the first time, i.e. during boot or memory hotplug;
4552 * or when mem_cgroup_disabled().
4554 if (likely(pc
) && PageCgroupUsed(pc
))
4559 bool mem_cgroup_bad_page_check(struct page
*page
)
4561 if (mem_cgroup_disabled())
4564 return lookup_page_cgroup_used(page
) != NULL
;
4567 void mem_cgroup_print_bad_page(struct page
*page
)
4569 struct page_cgroup
*pc
;
4571 pc
= lookup_page_cgroup_used(page
);
4573 pr_alert("pc:%p pc->flags:%lx pc->mem_cgroup:%p\n",
4574 pc
, pc
->flags
, pc
->mem_cgroup
);
4579 static int mem_cgroup_resize_limit(struct mem_cgroup
*memcg
,
4580 unsigned long long val
)
4583 u64 memswlimit
, memlimit
;
4585 int children
= mem_cgroup_count_children(memcg
);
4586 u64 curusage
, oldusage
;
4590 * For keeping hierarchical_reclaim simple, how long we should retry
4591 * is depends on callers. We set our retry-count to be function
4592 * of # of children which we should visit in this loop.
4594 retry_count
= MEM_CGROUP_RECLAIM_RETRIES
* children
;
4596 oldusage
= res_counter_read_u64(&memcg
->res
, RES_USAGE
);
4599 while (retry_count
) {
4600 if (signal_pending(current
)) {
4605 * Rather than hide all in some function, I do this in
4606 * open coded manner. You see what this really does.
4607 * We have to guarantee memcg->res.limit <= memcg->memsw.limit.
4609 mutex_lock(&set_limit_mutex
);
4610 memswlimit
= res_counter_read_u64(&memcg
->memsw
, RES_LIMIT
);
4611 if (memswlimit
< val
) {
4613 mutex_unlock(&set_limit_mutex
);
4617 memlimit
= res_counter_read_u64(&memcg
->res
, RES_LIMIT
);
4621 ret
= res_counter_set_limit(&memcg
->res
, val
);
4623 if (memswlimit
== val
)
4624 memcg
->memsw_is_minimum
= true;
4626 memcg
->memsw_is_minimum
= false;
4628 mutex_unlock(&set_limit_mutex
);
4633 mem_cgroup_reclaim(memcg
, GFP_KERNEL
,
4634 MEM_CGROUP_RECLAIM_SHRINK
);
4635 curusage
= res_counter_read_u64(&memcg
->res
, RES_USAGE
);
4636 /* Usage is reduced ? */
4637 if (curusage
>= oldusage
)
4640 oldusage
= curusage
;
4642 if (!ret
&& enlarge
)
4643 memcg_oom_recover(memcg
);
4648 static int mem_cgroup_resize_memsw_limit(struct mem_cgroup
*memcg
,
4649 unsigned long long val
)
4652 u64 memlimit
, memswlimit
, oldusage
, curusage
;
4653 int children
= mem_cgroup_count_children(memcg
);
4657 /* see mem_cgroup_resize_res_limit */
4658 retry_count
= children
* MEM_CGROUP_RECLAIM_RETRIES
;
4659 oldusage
= res_counter_read_u64(&memcg
->memsw
, RES_USAGE
);
4660 while (retry_count
) {
4661 if (signal_pending(current
)) {
4666 * Rather than hide all in some function, I do this in
4667 * open coded manner. You see what this really does.
4668 * We have to guarantee memcg->res.limit <= memcg->memsw.limit.
4670 mutex_lock(&set_limit_mutex
);
4671 memlimit
= res_counter_read_u64(&memcg
->res
, RES_LIMIT
);
4672 if (memlimit
> val
) {
4674 mutex_unlock(&set_limit_mutex
);
4677 memswlimit
= res_counter_read_u64(&memcg
->memsw
, RES_LIMIT
);
4678 if (memswlimit
< val
)
4680 ret
= res_counter_set_limit(&memcg
->memsw
, val
);
4682 if (memlimit
== val
)
4683 memcg
->memsw_is_minimum
= true;
4685 memcg
->memsw_is_minimum
= false;
4687 mutex_unlock(&set_limit_mutex
);
4692 mem_cgroup_reclaim(memcg
, GFP_KERNEL
,
4693 MEM_CGROUP_RECLAIM_NOSWAP
|
4694 MEM_CGROUP_RECLAIM_SHRINK
);
4695 curusage
= res_counter_read_u64(&memcg
->memsw
, RES_USAGE
);
4696 /* Usage is reduced ? */
4697 if (curusage
>= oldusage
)
4700 oldusage
= curusage
;
4702 if (!ret
&& enlarge
)
4703 memcg_oom_recover(memcg
);
4707 unsigned long mem_cgroup_soft_limit_reclaim(struct zone
*zone
, int order
,
4709 unsigned long *total_scanned
)
4711 unsigned long nr_reclaimed
= 0;
4712 struct mem_cgroup_per_zone
*mz
, *next_mz
= NULL
;
4713 unsigned long reclaimed
;
4715 struct mem_cgroup_tree_per_zone
*mctz
;
4716 unsigned long long excess
;
4717 unsigned long nr_scanned
;
4722 mctz
= soft_limit_tree_node_zone(zone_to_nid(zone
), zone_idx(zone
));
4724 * This loop can run a while, specially if mem_cgroup's continuously
4725 * keep exceeding their soft limit and putting the system under
4732 mz
= mem_cgroup_largest_soft_limit_node(mctz
);
4737 reclaimed
= mem_cgroup_soft_reclaim(mz
->memcg
, zone
,
4738 gfp_mask
, &nr_scanned
);
4739 nr_reclaimed
+= reclaimed
;
4740 *total_scanned
+= nr_scanned
;
4741 spin_lock(&mctz
->lock
);
4744 * If we failed to reclaim anything from this memory cgroup
4745 * it is time to move on to the next cgroup
4751 * Loop until we find yet another one.
4753 * By the time we get the soft_limit lock
4754 * again, someone might have aded the
4755 * group back on the RB tree. Iterate to
4756 * make sure we get a different mem.
4757 * mem_cgroup_largest_soft_limit_node returns
4758 * NULL if no other cgroup is present on
4762 __mem_cgroup_largest_soft_limit_node(mctz
);
4764 css_put(&next_mz
->memcg
->css
);
4765 else /* next_mz == NULL or other memcg */
4769 __mem_cgroup_remove_exceeded(mz
->memcg
, mz
, mctz
);
4770 excess
= res_counter_soft_limit_excess(&mz
->memcg
->res
);
4772 * One school of thought says that we should not add
4773 * back the node to the tree if reclaim returns 0.
4774 * But our reclaim could return 0, simply because due
4775 * to priority we are exposing a smaller subset of
4776 * memory to reclaim from. Consider this as a longer
4779 /* If excess == 0, no tree ops */
4780 __mem_cgroup_insert_exceeded(mz
->memcg
, mz
, mctz
, excess
);
4781 spin_unlock(&mctz
->lock
);
4782 css_put(&mz
->memcg
->css
);
4785 * Could not reclaim anything and there are no more
4786 * mem cgroups to try or we seem to be looping without
4787 * reclaiming anything.
4789 if (!nr_reclaimed
&&
4791 loop
> MEM_CGROUP_MAX_SOFT_LIMIT_RECLAIM_LOOPS
))
4793 } while (!nr_reclaimed
);
4795 css_put(&next_mz
->memcg
->css
);
4796 return nr_reclaimed
;
4800 * mem_cgroup_force_empty_list - clears LRU of a group
4801 * @memcg: group to clear
4804 * @lru: lru to to clear
4806 * Traverse a specified page_cgroup list and try to drop them all. This doesn't
4807 * reclaim the pages page themselves - pages are moved to the parent (or root)
4810 static void mem_cgroup_force_empty_list(struct mem_cgroup
*memcg
,
4811 int node
, int zid
, enum lru_list lru
)
4813 struct lruvec
*lruvec
;
4814 unsigned long flags
;
4815 struct list_head
*list
;
4819 zone
= &NODE_DATA(node
)->node_zones
[zid
];
4820 lruvec
= mem_cgroup_zone_lruvec(zone
, memcg
);
4821 list
= &lruvec
->lists
[lru
];
4825 struct page_cgroup
*pc
;
4828 spin_lock_irqsave(&zone
->lru_lock
, flags
);
4829 if (list_empty(list
)) {
4830 spin_unlock_irqrestore(&zone
->lru_lock
, flags
);
4833 page
= list_entry(list
->prev
, struct page
, lru
);
4835 list_move(&page
->lru
, list
);
4837 spin_unlock_irqrestore(&zone
->lru_lock
, flags
);
4840 spin_unlock_irqrestore(&zone
->lru_lock
, flags
);
4842 pc
= lookup_page_cgroup(page
);
4844 if (mem_cgroup_move_parent(page
, pc
, memcg
)) {
4845 /* found lock contention or "pc" is obsolete. */
4850 } while (!list_empty(list
));
4854 * make mem_cgroup's charge to be 0 if there is no task by moving
4855 * all the charges and pages to the parent.
4856 * This enables deleting this mem_cgroup.
4858 * Caller is responsible for holding css reference on the memcg.
4860 static void mem_cgroup_reparent_charges(struct mem_cgroup
*memcg
)
4866 /* This is for making all *used* pages to be on LRU. */
4867 lru_add_drain_all();
4868 drain_all_stock_sync(memcg
);
4869 mem_cgroup_start_move(memcg
);
4870 for_each_node_state(node
, N_MEMORY
) {
4871 for (zid
= 0; zid
< MAX_NR_ZONES
; zid
++) {
4874 mem_cgroup_force_empty_list(memcg
,
4879 mem_cgroup_end_move(memcg
);
4880 memcg_oom_recover(memcg
);
4884 * Kernel memory may not necessarily be trackable to a specific
4885 * process. So they are not migrated, and therefore we can't
4886 * expect their value to drop to 0 here.
4887 * Having res filled up with kmem only is enough.
4889 * This is a safety check because mem_cgroup_force_empty_list
4890 * could have raced with mem_cgroup_replace_page_cache callers
4891 * so the lru seemed empty but the page could have been added
4892 * right after the check. RES_USAGE should be safe as we always
4893 * charge before adding to the LRU.
4895 usage
= res_counter_read_u64(&memcg
->res
, RES_USAGE
) -
4896 res_counter_read_u64(&memcg
->kmem
, RES_USAGE
);
4897 } while (usage
> 0);
4901 * This mainly exists for tests during the setting of set of use_hierarchy.
4902 * Since this is the very setting we are changing, the current hierarchy value
4905 static inline bool __memcg_has_children(struct mem_cgroup
*memcg
)
4909 /* bounce at first found */
4910 cgroup_for_each_child(pos
, memcg
->css
.cgroup
)
4916 * Must be called with memcg_create_mutex held, unless the cgroup is guaranteed
4917 * to be already dead (as in mem_cgroup_force_empty, for instance). This is
4918 * from mem_cgroup_count_children(), in the sense that we don't really care how
4919 * many children we have; we only need to know if we have any. It also counts
4920 * any memcg without hierarchy as infertile.
4922 static inline bool memcg_has_children(struct mem_cgroup
*memcg
)
4924 return memcg
->use_hierarchy
&& __memcg_has_children(memcg
);
4928 * Reclaims as many pages from the given memcg as possible and moves
4929 * the rest to the parent.
4931 * Caller is responsible for holding css reference for memcg.
4933 static int mem_cgroup_force_empty(struct mem_cgroup
*memcg
)
4935 int nr_retries
= MEM_CGROUP_RECLAIM_RETRIES
;
4936 struct cgroup
*cgrp
= memcg
->css
.cgroup
;
4938 /* returns EBUSY if there is a task or if we come here twice. */
4939 if (cgroup_task_count(cgrp
) || !list_empty(&cgrp
->children
))
4942 /* we call try-to-free pages for make this cgroup empty */
4943 lru_add_drain_all();
4944 /* try to free all pages in this cgroup */
4945 while (nr_retries
&& res_counter_read_u64(&memcg
->res
, RES_USAGE
) > 0) {
4948 if (signal_pending(current
))
4951 progress
= try_to_free_mem_cgroup_pages(memcg
, GFP_KERNEL
,
4955 /* maybe some writeback is necessary */
4956 congestion_wait(BLK_RW_ASYNC
, HZ
/10);
4961 mem_cgroup_reparent_charges(memcg
);
4966 static int mem_cgroup_force_empty_write(struct cgroup
*cont
, unsigned int event
)
4968 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cont
);
4971 if (mem_cgroup_is_root(memcg
))
4973 css_get(&memcg
->css
);
4974 ret
= mem_cgroup_force_empty(memcg
);
4975 css_put(&memcg
->css
);
4981 static u64
mem_cgroup_hierarchy_read(struct cgroup
*cont
, struct cftype
*cft
)
4983 return mem_cgroup_from_cont(cont
)->use_hierarchy
;
4986 static int mem_cgroup_hierarchy_write(struct cgroup
*cont
, struct cftype
*cft
,
4990 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cont
);
4991 struct cgroup
*parent
= cont
->parent
;
4992 struct mem_cgroup
*parent_memcg
= NULL
;
4995 parent_memcg
= mem_cgroup_from_cont(parent
);
4997 mutex_lock(&memcg_create_mutex
);
4999 if (memcg
->use_hierarchy
== val
)
5003 * If parent's use_hierarchy is set, we can't make any modifications
5004 * in the child subtrees. If it is unset, then the change can
5005 * occur, provided the current cgroup has no children.
5007 * For the root cgroup, parent_mem is NULL, we allow value to be
5008 * set if there are no children.
5010 if ((!parent_memcg
|| !parent_memcg
->use_hierarchy
) &&
5011 (val
== 1 || val
== 0)) {
5012 if (!__memcg_has_children(memcg
))
5013 memcg
->use_hierarchy
= val
;
5020 mutex_unlock(&memcg_create_mutex
);
5026 static unsigned long mem_cgroup_recursive_stat(struct mem_cgroup
*memcg
,
5027 enum mem_cgroup_stat_index idx
)
5029 struct mem_cgroup
*iter
;
5032 /* Per-cpu values can be negative, use a signed accumulator */
5033 for_each_mem_cgroup_tree(iter
, memcg
)
5034 val
+= mem_cgroup_read_stat(iter
, idx
);
5036 if (val
< 0) /* race ? */
5041 static inline u64
mem_cgroup_usage(struct mem_cgroup
*memcg
, bool swap
)
5045 if (!mem_cgroup_is_root(memcg
)) {
5047 return res_counter_read_u64(&memcg
->res
, RES_USAGE
);
5049 return res_counter_read_u64(&memcg
->memsw
, RES_USAGE
);
5053 * Transparent hugepages are still accounted for in MEM_CGROUP_STAT_RSS
5054 * as well as in MEM_CGROUP_STAT_RSS_HUGE.
5056 val
= mem_cgroup_recursive_stat(memcg
, MEM_CGROUP_STAT_CACHE
);
5057 val
+= mem_cgroup_recursive_stat(memcg
, MEM_CGROUP_STAT_RSS
);
5060 val
+= mem_cgroup_recursive_stat(memcg
, MEM_CGROUP_STAT_SWAP
);
5062 return val
<< PAGE_SHIFT
;
5065 static ssize_t
mem_cgroup_read(struct cgroup
*cont
, struct cftype
*cft
,
5066 struct file
*file
, char __user
*buf
,
5067 size_t nbytes
, loff_t
*ppos
)
5069 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cont
);
5075 type
= MEMFILE_TYPE(cft
->private);
5076 name
= MEMFILE_ATTR(cft
->private);
5080 if (name
== RES_USAGE
)
5081 val
= mem_cgroup_usage(memcg
, false);
5083 val
= res_counter_read_u64(&memcg
->res
, name
);
5086 if (name
== RES_USAGE
)
5087 val
= mem_cgroup_usage(memcg
, true);
5089 val
= res_counter_read_u64(&memcg
->memsw
, name
);
5092 val
= res_counter_read_u64(&memcg
->kmem
, name
);
5098 len
= scnprintf(str
, sizeof(str
), "%llu\n", (unsigned long long)val
);
5099 return simple_read_from_buffer(buf
, nbytes
, ppos
, str
, len
);
5102 static int memcg_update_kmem_limit(struct cgroup
*cont
, u64 val
)
5105 #ifdef CONFIG_MEMCG_KMEM
5106 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cont
);
5108 * For simplicity, we won't allow this to be disabled. It also can't
5109 * be changed if the cgroup has children already, or if tasks had
5112 * If tasks join before we set the limit, a person looking at
5113 * kmem.usage_in_bytes will have no way to determine when it took
5114 * place, which makes the value quite meaningless.
5116 * After it first became limited, changes in the value of the limit are
5117 * of course permitted.
5119 mutex_lock(&memcg_create_mutex
);
5120 mutex_lock(&set_limit_mutex
);
5121 if (!memcg
->kmem_account_flags
&& val
!= RESOURCE_MAX
) {
5122 if (cgroup_task_count(cont
) || memcg_has_children(memcg
)) {
5126 ret
= res_counter_set_limit(&memcg
->kmem
, val
);
5129 ret
= memcg_update_cache_sizes(memcg
);
5131 res_counter_set_limit(&memcg
->kmem
, RESOURCE_MAX
);
5134 static_key_slow_inc(&memcg_kmem_enabled_key
);
5136 * setting the active bit after the inc will guarantee no one
5137 * starts accounting before all call sites are patched
5139 memcg_kmem_set_active(memcg
);
5142 * kmem charges can outlive the cgroup. In the case of slab
5143 * pages, for instance, a page contain objects from various
5144 * processes, so it is unfeasible to migrate them away. We
5145 * need to reference count the memcg because of that.
5147 mem_cgroup_get(memcg
);
5149 ret
= res_counter_set_limit(&memcg
->kmem
, val
);
5151 mutex_unlock(&set_limit_mutex
);
5152 mutex_unlock(&memcg_create_mutex
);
5157 #ifdef CONFIG_MEMCG_KMEM
5158 static int memcg_propagate_kmem(struct mem_cgroup
*memcg
)
5161 struct mem_cgroup
*parent
= parent_mem_cgroup(memcg
);
5165 memcg
->kmem_account_flags
= parent
->kmem_account_flags
;
5167 * When that happen, we need to disable the static branch only on those
5168 * memcgs that enabled it. To achieve this, we would be forced to
5169 * complicate the code by keeping track of which memcgs were the ones
5170 * that actually enabled limits, and which ones got it from its
5173 * It is a lot simpler just to do static_key_slow_inc() on every child
5174 * that is accounted.
5176 if (!memcg_kmem_is_active(memcg
))
5180 * destroy(), called if we fail, will issue static_key_slow_inc() and
5181 * mem_cgroup_put() if kmem is enabled. We have to either call them
5182 * unconditionally, or clear the KMEM_ACTIVE flag. I personally find
5183 * this more consistent, since it always leads to the same destroy path
5185 mem_cgroup_get(memcg
);
5186 static_key_slow_inc(&memcg_kmem_enabled_key
);
5188 mutex_lock(&set_limit_mutex
);
5189 ret
= memcg_update_cache_sizes(memcg
);
5190 mutex_unlock(&set_limit_mutex
);
5194 #endif /* CONFIG_MEMCG_KMEM */
5197 * The user of this function is...
5200 static int mem_cgroup_write(struct cgroup
*cont
, struct cftype
*cft
,
5203 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cont
);
5206 unsigned long long val
;
5209 type
= MEMFILE_TYPE(cft
->private);
5210 name
= MEMFILE_ATTR(cft
->private);
5214 if (mem_cgroup_is_root(memcg
)) { /* Can't set limit on root */
5218 /* This function does all necessary parse...reuse it */
5219 ret
= res_counter_memparse_write_strategy(buffer
, &val
);
5223 ret
= mem_cgroup_resize_limit(memcg
, val
);
5224 else if (type
== _MEMSWAP
)
5225 ret
= mem_cgroup_resize_memsw_limit(memcg
, val
);
5226 else if (type
== _KMEM
)
5227 ret
= memcg_update_kmem_limit(cont
, val
);
5231 case RES_SOFT_LIMIT
:
5232 ret
= res_counter_memparse_write_strategy(buffer
, &val
);
5236 * For memsw, soft limits are hard to implement in terms
5237 * of semantics, for now, we support soft limits for
5238 * control without swap
5241 ret
= res_counter_set_soft_limit(&memcg
->res
, val
);
5246 ret
= -EINVAL
; /* should be BUG() ? */
5252 static void memcg_get_hierarchical_limit(struct mem_cgroup
*memcg
,
5253 unsigned long long *mem_limit
, unsigned long long *memsw_limit
)
5255 struct cgroup
*cgroup
;
5256 unsigned long long min_limit
, min_memsw_limit
, tmp
;
5258 min_limit
= res_counter_read_u64(&memcg
->res
, RES_LIMIT
);
5259 min_memsw_limit
= res_counter_read_u64(&memcg
->memsw
, RES_LIMIT
);
5260 cgroup
= memcg
->css
.cgroup
;
5261 if (!memcg
->use_hierarchy
)
5264 while (cgroup
->parent
) {
5265 cgroup
= cgroup
->parent
;
5266 memcg
= mem_cgroup_from_cont(cgroup
);
5267 if (!memcg
->use_hierarchy
)
5269 tmp
= res_counter_read_u64(&memcg
->res
, RES_LIMIT
);
5270 min_limit
= min(min_limit
, tmp
);
5271 tmp
= res_counter_read_u64(&memcg
->memsw
, RES_LIMIT
);
5272 min_memsw_limit
= min(min_memsw_limit
, tmp
);
5275 *mem_limit
= min_limit
;
5276 *memsw_limit
= min_memsw_limit
;
5279 static int mem_cgroup_reset(struct cgroup
*cont
, unsigned int event
)
5281 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cont
);
5285 type
= MEMFILE_TYPE(event
);
5286 name
= MEMFILE_ATTR(event
);
5291 res_counter_reset_max(&memcg
->res
);
5292 else if (type
== _MEMSWAP
)
5293 res_counter_reset_max(&memcg
->memsw
);
5294 else if (type
== _KMEM
)
5295 res_counter_reset_max(&memcg
->kmem
);
5301 res_counter_reset_failcnt(&memcg
->res
);
5302 else if (type
== _MEMSWAP
)
5303 res_counter_reset_failcnt(&memcg
->memsw
);
5304 else if (type
== _KMEM
)
5305 res_counter_reset_failcnt(&memcg
->kmem
);
5314 static u64
mem_cgroup_move_charge_read(struct cgroup
*cgrp
,
5317 return mem_cgroup_from_cont(cgrp
)->move_charge_at_immigrate
;
5321 static int mem_cgroup_move_charge_write(struct cgroup
*cgrp
,
5322 struct cftype
*cft
, u64 val
)
5324 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cgrp
);
5326 if (val
>= (1 << NR_MOVE_TYPE
))
5330 * No kind of locking is needed in here, because ->can_attach() will
5331 * check this value once in the beginning of the process, and then carry
5332 * on with stale data. This means that changes to this value will only
5333 * affect task migrations starting after the change.
5335 memcg
->move_charge_at_immigrate
= val
;
5339 static int mem_cgroup_move_charge_write(struct cgroup
*cgrp
,
5340 struct cftype
*cft
, u64 val
)
5347 static int memcg_numa_stat_show(struct cgroup
*cont
, struct cftype
*cft
,
5351 unsigned long total_nr
, file_nr
, anon_nr
, unevictable_nr
;
5352 unsigned long node_nr
;
5353 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cont
);
5355 total_nr
= mem_cgroup_nr_lru_pages(memcg
, LRU_ALL
);
5356 seq_printf(m
, "total=%lu", total_nr
);
5357 for_each_node_state(nid
, N_MEMORY
) {
5358 node_nr
= mem_cgroup_node_nr_lru_pages(memcg
, nid
, LRU_ALL
);
5359 seq_printf(m
, " N%d=%lu", nid
, node_nr
);
5363 file_nr
= mem_cgroup_nr_lru_pages(memcg
, LRU_ALL_FILE
);
5364 seq_printf(m
, "file=%lu", file_nr
);
5365 for_each_node_state(nid
, N_MEMORY
) {
5366 node_nr
= mem_cgroup_node_nr_lru_pages(memcg
, nid
,
5368 seq_printf(m
, " N%d=%lu", nid
, node_nr
);
5372 anon_nr
= mem_cgroup_nr_lru_pages(memcg
, LRU_ALL_ANON
);
5373 seq_printf(m
, "anon=%lu", anon_nr
);
5374 for_each_node_state(nid
, N_MEMORY
) {
5375 node_nr
= mem_cgroup_node_nr_lru_pages(memcg
, nid
,
5377 seq_printf(m
, " N%d=%lu", nid
, node_nr
);
5381 unevictable_nr
= mem_cgroup_nr_lru_pages(memcg
, BIT(LRU_UNEVICTABLE
));
5382 seq_printf(m
, "unevictable=%lu", unevictable_nr
);
5383 for_each_node_state(nid
, N_MEMORY
) {
5384 node_nr
= mem_cgroup_node_nr_lru_pages(memcg
, nid
,
5385 BIT(LRU_UNEVICTABLE
));
5386 seq_printf(m
, " N%d=%lu", nid
, node_nr
);
5391 #endif /* CONFIG_NUMA */
5393 static inline void mem_cgroup_lru_names_not_uptodate(void)
5395 BUILD_BUG_ON(ARRAY_SIZE(mem_cgroup_lru_names
) != NR_LRU_LISTS
);
5398 static int memcg_stat_show(struct cgroup
*cont
, struct cftype
*cft
,
5401 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cont
);
5402 struct mem_cgroup
*mi
;
5405 for (i
= 0; i
< MEM_CGROUP_STAT_NSTATS
; i
++) {
5406 if (i
== MEM_CGROUP_STAT_SWAP
&& !do_swap_account
)
5408 seq_printf(m
, "%s %ld\n", mem_cgroup_stat_names
[i
],
5409 mem_cgroup_read_stat(memcg
, i
) * PAGE_SIZE
);
5412 for (i
= 0; i
< MEM_CGROUP_EVENTS_NSTATS
; i
++)
5413 seq_printf(m
, "%s %lu\n", mem_cgroup_events_names
[i
],
5414 mem_cgroup_read_events(memcg
, i
));
5416 for (i
= 0; i
< NR_LRU_LISTS
; i
++)
5417 seq_printf(m
, "%s %lu\n", mem_cgroup_lru_names
[i
],
5418 mem_cgroup_nr_lru_pages(memcg
, BIT(i
)) * PAGE_SIZE
);
5420 /* Hierarchical information */
5422 unsigned long long limit
, memsw_limit
;
5423 memcg_get_hierarchical_limit(memcg
, &limit
, &memsw_limit
);
5424 seq_printf(m
, "hierarchical_memory_limit %llu\n", limit
);
5425 if (do_swap_account
)
5426 seq_printf(m
, "hierarchical_memsw_limit %llu\n",
5430 for (i
= 0; i
< MEM_CGROUP_STAT_NSTATS
; i
++) {
5433 if (i
== MEM_CGROUP_STAT_SWAP
&& !do_swap_account
)
5435 for_each_mem_cgroup_tree(mi
, memcg
)
5436 val
+= mem_cgroup_read_stat(mi
, i
) * PAGE_SIZE
;
5437 seq_printf(m
, "total_%s %lld\n", mem_cgroup_stat_names
[i
], val
);
5440 for (i
= 0; i
< MEM_CGROUP_EVENTS_NSTATS
; i
++) {
5441 unsigned long long val
= 0;
5443 for_each_mem_cgroup_tree(mi
, memcg
)
5444 val
+= mem_cgroup_read_events(mi
, i
);
5445 seq_printf(m
, "total_%s %llu\n",
5446 mem_cgroup_events_names
[i
], val
);
5449 for (i
= 0; i
< NR_LRU_LISTS
; i
++) {
5450 unsigned long long val
= 0;
5452 for_each_mem_cgroup_tree(mi
, memcg
)
5453 val
+= mem_cgroup_nr_lru_pages(mi
, BIT(i
)) * PAGE_SIZE
;
5454 seq_printf(m
, "total_%s %llu\n", mem_cgroup_lru_names
[i
], val
);
5457 #ifdef CONFIG_DEBUG_VM
5460 struct mem_cgroup_per_zone
*mz
;
5461 struct zone_reclaim_stat
*rstat
;
5462 unsigned long recent_rotated
[2] = {0, 0};
5463 unsigned long recent_scanned
[2] = {0, 0};
5465 for_each_online_node(nid
)
5466 for (zid
= 0; zid
< MAX_NR_ZONES
; zid
++) {
5467 mz
= mem_cgroup_zoneinfo(memcg
, nid
, zid
);
5468 rstat
= &mz
->lruvec
.reclaim_stat
;
5470 recent_rotated
[0] += rstat
->recent_rotated
[0];
5471 recent_rotated
[1] += rstat
->recent_rotated
[1];
5472 recent_scanned
[0] += rstat
->recent_scanned
[0];
5473 recent_scanned
[1] += rstat
->recent_scanned
[1];
5475 seq_printf(m
, "recent_rotated_anon %lu\n", recent_rotated
[0]);
5476 seq_printf(m
, "recent_rotated_file %lu\n", recent_rotated
[1]);
5477 seq_printf(m
, "recent_scanned_anon %lu\n", recent_scanned
[0]);
5478 seq_printf(m
, "recent_scanned_file %lu\n", recent_scanned
[1]);
5485 static u64
mem_cgroup_swappiness_read(struct cgroup
*cgrp
, struct cftype
*cft
)
5487 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cgrp
);
5489 return mem_cgroup_swappiness(memcg
);
5492 static int mem_cgroup_swappiness_write(struct cgroup
*cgrp
, struct cftype
*cft
,
5495 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cgrp
);
5496 struct mem_cgroup
*parent
;
5501 if (cgrp
->parent
== NULL
)
5504 parent
= mem_cgroup_from_cont(cgrp
->parent
);
5506 mutex_lock(&memcg_create_mutex
);
5508 /* If under hierarchy, only empty-root can set this value */
5509 if ((parent
->use_hierarchy
) || memcg_has_children(memcg
)) {
5510 mutex_unlock(&memcg_create_mutex
);
5514 memcg
->swappiness
= val
;
5516 mutex_unlock(&memcg_create_mutex
);
5521 static void __mem_cgroup_threshold(struct mem_cgroup
*memcg
, bool swap
)
5523 struct mem_cgroup_threshold_ary
*t
;
5529 t
= rcu_dereference(memcg
->thresholds
.primary
);
5531 t
= rcu_dereference(memcg
->memsw_thresholds
.primary
);
5536 usage
= mem_cgroup_usage(memcg
, swap
);
5539 * current_threshold points to threshold just below or equal to usage.
5540 * If it's not true, a threshold was crossed after last
5541 * call of __mem_cgroup_threshold().
5543 i
= t
->current_threshold
;
5546 * Iterate backward over array of thresholds starting from
5547 * current_threshold and check if a threshold is crossed.
5548 * If none of thresholds below usage is crossed, we read
5549 * only one element of the array here.
5551 for (; i
>= 0 && unlikely(t
->entries
[i
].threshold
> usage
); i
--)
5552 eventfd_signal(t
->entries
[i
].eventfd
, 1);
5554 /* i = current_threshold + 1 */
5558 * Iterate forward over array of thresholds starting from
5559 * current_threshold+1 and check if a threshold is crossed.
5560 * If none of thresholds above usage is crossed, we read
5561 * only one element of the array here.
5563 for (; i
< t
->size
&& unlikely(t
->entries
[i
].threshold
<= usage
); i
++)
5564 eventfd_signal(t
->entries
[i
].eventfd
, 1);
5566 /* Update current_threshold */
5567 t
->current_threshold
= i
- 1;
5572 static void mem_cgroup_threshold(struct mem_cgroup
*memcg
)
5575 __mem_cgroup_threshold(memcg
, false);
5576 if (do_swap_account
)
5577 __mem_cgroup_threshold(memcg
, true);
5579 memcg
= parent_mem_cgroup(memcg
);
5583 static int compare_thresholds(const void *a
, const void *b
)
5585 const struct mem_cgroup_threshold
*_a
= a
;
5586 const struct mem_cgroup_threshold
*_b
= b
;
5588 return _a
->threshold
- _b
->threshold
;
5591 static int mem_cgroup_oom_notify_cb(struct mem_cgroup
*memcg
)
5593 struct mem_cgroup_eventfd_list
*ev
;
5595 list_for_each_entry(ev
, &memcg
->oom_notify
, list
)
5596 eventfd_signal(ev
->eventfd
, 1);
5600 static void mem_cgroup_oom_notify(struct mem_cgroup
*memcg
)
5602 struct mem_cgroup
*iter
;
5604 for_each_mem_cgroup_tree(iter
, memcg
)
5605 mem_cgroup_oom_notify_cb(iter
);
5608 static int mem_cgroup_usage_register_event(struct cgroup
*cgrp
,
5609 struct cftype
*cft
, struct eventfd_ctx
*eventfd
, const char *args
)
5611 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cgrp
);
5612 struct mem_cgroup_thresholds
*thresholds
;
5613 struct mem_cgroup_threshold_ary
*new;
5614 enum res_type type
= MEMFILE_TYPE(cft
->private);
5615 u64 threshold
, usage
;
5618 ret
= res_counter_memparse_write_strategy(args
, &threshold
);
5622 mutex_lock(&memcg
->thresholds_lock
);
5625 thresholds
= &memcg
->thresholds
;
5626 else if (type
== _MEMSWAP
)
5627 thresholds
= &memcg
->memsw_thresholds
;
5631 usage
= mem_cgroup_usage(memcg
, type
== _MEMSWAP
);
5633 /* Check if a threshold crossed before adding a new one */
5634 if (thresholds
->primary
)
5635 __mem_cgroup_threshold(memcg
, type
== _MEMSWAP
);
5637 size
= thresholds
->primary
? thresholds
->primary
->size
+ 1 : 1;
5639 /* Allocate memory for new array of thresholds */
5640 new = kmalloc(sizeof(*new) + size
* sizeof(struct mem_cgroup_threshold
),
5648 /* Copy thresholds (if any) to new array */
5649 if (thresholds
->primary
) {
5650 memcpy(new->entries
, thresholds
->primary
->entries
, (size
- 1) *
5651 sizeof(struct mem_cgroup_threshold
));
5654 /* Add new threshold */
5655 new->entries
[size
- 1].eventfd
= eventfd
;
5656 new->entries
[size
- 1].threshold
= threshold
;
5658 /* Sort thresholds. Registering of new threshold isn't time-critical */
5659 sort(new->entries
, size
, sizeof(struct mem_cgroup_threshold
),
5660 compare_thresholds
, NULL
);
5662 /* Find current threshold */
5663 new->current_threshold
= -1;
5664 for (i
= 0; i
< size
; i
++) {
5665 if (new->entries
[i
].threshold
<= usage
) {
5667 * new->current_threshold will not be used until
5668 * rcu_assign_pointer(), so it's safe to increment
5671 ++new->current_threshold
;
5676 /* Free old spare buffer and save old primary buffer as spare */
5677 kfree(thresholds
->spare
);
5678 thresholds
->spare
= thresholds
->primary
;
5680 rcu_assign_pointer(thresholds
->primary
, new);
5682 /* To be sure that nobody uses thresholds */
5686 mutex_unlock(&memcg
->thresholds_lock
);
5691 static void mem_cgroup_usage_unregister_event(struct cgroup
*cgrp
,
5692 struct cftype
*cft
, struct eventfd_ctx
*eventfd
)
5694 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cgrp
);
5695 struct mem_cgroup_thresholds
*thresholds
;
5696 struct mem_cgroup_threshold_ary
*new;
5697 enum res_type type
= MEMFILE_TYPE(cft
->private);
5701 mutex_lock(&memcg
->thresholds_lock
);
5703 thresholds
= &memcg
->thresholds
;
5704 else if (type
== _MEMSWAP
)
5705 thresholds
= &memcg
->memsw_thresholds
;
5709 if (!thresholds
->primary
)
5712 usage
= mem_cgroup_usage(memcg
, type
== _MEMSWAP
);
5714 /* Check if a threshold crossed before removing */
5715 __mem_cgroup_threshold(memcg
, type
== _MEMSWAP
);
5717 /* Calculate new number of threshold */
5719 for (i
= 0; i
< thresholds
->primary
->size
; i
++) {
5720 if (thresholds
->primary
->entries
[i
].eventfd
!= eventfd
)
5724 new = thresholds
->spare
;
5726 /* Set thresholds array to NULL if we don't have thresholds */
5735 /* Copy thresholds and find current threshold */
5736 new->current_threshold
= -1;
5737 for (i
= 0, j
= 0; i
< thresholds
->primary
->size
; i
++) {
5738 if (thresholds
->primary
->entries
[i
].eventfd
== eventfd
)
5741 new->entries
[j
] = thresholds
->primary
->entries
[i
];
5742 if (new->entries
[j
].threshold
<= usage
) {
5744 * new->current_threshold will not be used
5745 * until rcu_assign_pointer(), so it's safe to increment
5748 ++new->current_threshold
;
5754 /* Swap primary and spare array */
5755 thresholds
->spare
= thresholds
->primary
;
5756 /* If all events are unregistered, free the spare array */
5758 kfree(thresholds
->spare
);
5759 thresholds
->spare
= NULL
;
5762 rcu_assign_pointer(thresholds
->primary
, new);
5764 /* To be sure that nobody uses thresholds */
5767 mutex_unlock(&memcg
->thresholds_lock
);
5770 static int mem_cgroup_oom_register_event(struct cgroup
*cgrp
,
5771 struct cftype
*cft
, struct eventfd_ctx
*eventfd
, const char *args
)
5773 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cgrp
);
5774 struct mem_cgroup_eventfd_list
*event
;
5775 enum res_type type
= MEMFILE_TYPE(cft
->private);
5777 BUG_ON(type
!= _OOM_TYPE
);
5778 event
= kmalloc(sizeof(*event
), GFP_KERNEL
);
5782 spin_lock(&memcg_oom_lock
);
5784 event
->eventfd
= eventfd
;
5785 list_add(&event
->list
, &memcg
->oom_notify
);
5787 /* already in OOM ? */
5788 if (atomic_read(&memcg
->under_oom
))
5789 eventfd_signal(eventfd
, 1);
5790 spin_unlock(&memcg_oom_lock
);
5795 static void mem_cgroup_oom_unregister_event(struct cgroup
*cgrp
,
5796 struct cftype
*cft
, struct eventfd_ctx
*eventfd
)
5798 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cgrp
);
5799 struct mem_cgroup_eventfd_list
*ev
, *tmp
;
5800 enum res_type type
= MEMFILE_TYPE(cft
->private);
5802 BUG_ON(type
!= _OOM_TYPE
);
5804 spin_lock(&memcg_oom_lock
);
5806 list_for_each_entry_safe(ev
, tmp
, &memcg
->oom_notify
, list
) {
5807 if (ev
->eventfd
== eventfd
) {
5808 list_del(&ev
->list
);
5813 spin_unlock(&memcg_oom_lock
);
5816 static int mem_cgroup_oom_control_read(struct cgroup
*cgrp
,
5817 struct cftype
*cft
, struct cgroup_map_cb
*cb
)
5819 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cgrp
);
5821 cb
->fill(cb
, "oom_kill_disable", memcg
->oom_kill_disable
);
5823 if (atomic_read(&memcg
->under_oom
))
5824 cb
->fill(cb
, "under_oom", 1);
5826 cb
->fill(cb
, "under_oom", 0);
5830 static int mem_cgroup_oom_control_write(struct cgroup
*cgrp
,
5831 struct cftype
*cft
, u64 val
)
5833 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cgrp
);
5834 struct mem_cgroup
*parent
;
5836 /* cannot set to root cgroup and only 0 and 1 are allowed */
5837 if (!cgrp
->parent
|| !((val
== 0) || (val
== 1)))
5840 parent
= mem_cgroup_from_cont(cgrp
->parent
);
5842 mutex_lock(&memcg_create_mutex
);
5843 /* oom-kill-disable is a flag for subhierarchy. */
5844 if ((parent
->use_hierarchy
) || memcg_has_children(memcg
)) {
5845 mutex_unlock(&memcg_create_mutex
);
5848 memcg
->oom_kill_disable
= val
;
5850 memcg_oom_recover(memcg
);
5851 mutex_unlock(&memcg_create_mutex
);
5855 #ifdef CONFIG_MEMCG_KMEM
5856 static int memcg_init_kmem(struct mem_cgroup
*memcg
, struct cgroup_subsys
*ss
)
5860 memcg
->kmemcg_id
= -1;
5861 ret
= memcg_propagate_kmem(memcg
);
5865 return mem_cgroup_sockets_init(memcg
, ss
);
5868 static void kmem_cgroup_destroy(struct mem_cgroup
*memcg
)
5870 mem_cgroup_sockets_destroy(memcg
);
5872 memcg_kmem_mark_dead(memcg
);
5874 if (res_counter_read_u64(&memcg
->kmem
, RES_USAGE
) != 0)
5878 * Charges already down to 0, undo mem_cgroup_get() done in the charge
5879 * path here, being careful not to race with memcg_uncharge_kmem: it is
5880 * possible that the charges went down to 0 between mark_dead and the
5881 * res_counter read, so in that case, we don't need the put
5883 if (memcg_kmem_test_and_clear_dead(memcg
))
5884 mem_cgroup_put(memcg
);
5887 static int memcg_init_kmem(struct mem_cgroup
*memcg
, struct cgroup_subsys
*ss
)
5892 static void kmem_cgroup_destroy(struct mem_cgroup
*memcg
)
5897 static struct cftype mem_cgroup_files
[] = {
5899 .name
= "usage_in_bytes",
5900 .private = MEMFILE_PRIVATE(_MEM
, RES_USAGE
),
5901 .read
= mem_cgroup_read
,
5902 .register_event
= mem_cgroup_usage_register_event
,
5903 .unregister_event
= mem_cgroup_usage_unregister_event
,
5906 .name
= "max_usage_in_bytes",
5907 .private = MEMFILE_PRIVATE(_MEM
, RES_MAX_USAGE
),
5908 .trigger
= mem_cgroup_reset
,
5909 .read
= mem_cgroup_read
,
5912 .name
= "limit_in_bytes",
5913 .private = MEMFILE_PRIVATE(_MEM
, RES_LIMIT
),
5914 .write_string
= mem_cgroup_write
,
5915 .read
= mem_cgroup_read
,
5918 .name
= "soft_limit_in_bytes",
5919 .private = MEMFILE_PRIVATE(_MEM
, RES_SOFT_LIMIT
),
5920 .write_string
= mem_cgroup_write
,
5921 .read
= mem_cgroup_read
,
5925 .private = MEMFILE_PRIVATE(_MEM
, RES_FAILCNT
),
5926 .trigger
= mem_cgroup_reset
,
5927 .read
= mem_cgroup_read
,
5931 .read_seq_string
= memcg_stat_show
,
5934 .name
= "force_empty",
5935 .trigger
= mem_cgroup_force_empty_write
,
5938 .name
= "use_hierarchy",
5939 .flags
= CFTYPE_INSANE
,
5940 .write_u64
= mem_cgroup_hierarchy_write
,
5941 .read_u64
= mem_cgroup_hierarchy_read
,
5944 .name
= "swappiness",
5945 .read_u64
= mem_cgroup_swappiness_read
,
5946 .write_u64
= mem_cgroup_swappiness_write
,
5949 .name
= "move_charge_at_immigrate",
5950 .read_u64
= mem_cgroup_move_charge_read
,
5951 .write_u64
= mem_cgroup_move_charge_write
,
5954 .name
= "oom_control",
5955 .read_map
= mem_cgroup_oom_control_read
,
5956 .write_u64
= mem_cgroup_oom_control_write
,
5957 .register_event
= mem_cgroup_oom_register_event
,
5958 .unregister_event
= mem_cgroup_oom_unregister_event
,
5959 .private = MEMFILE_PRIVATE(_OOM_TYPE
, OOM_CONTROL
),
5962 .name
= "pressure_level",
5963 .register_event
= vmpressure_register_event
,
5964 .unregister_event
= vmpressure_unregister_event
,
5968 .name
= "numa_stat",
5969 .read_seq_string
= memcg_numa_stat_show
,
5972 #ifdef CONFIG_MEMCG_KMEM
5974 .name
= "kmem.limit_in_bytes",
5975 .private = MEMFILE_PRIVATE(_KMEM
, RES_LIMIT
),
5976 .write_string
= mem_cgroup_write
,
5977 .read
= mem_cgroup_read
,
5980 .name
= "kmem.usage_in_bytes",
5981 .private = MEMFILE_PRIVATE(_KMEM
, RES_USAGE
),
5982 .read
= mem_cgroup_read
,
5985 .name
= "kmem.failcnt",
5986 .private = MEMFILE_PRIVATE(_KMEM
, RES_FAILCNT
),
5987 .trigger
= mem_cgroup_reset
,
5988 .read
= mem_cgroup_read
,
5991 .name
= "kmem.max_usage_in_bytes",
5992 .private = MEMFILE_PRIVATE(_KMEM
, RES_MAX_USAGE
),
5993 .trigger
= mem_cgroup_reset
,
5994 .read
= mem_cgroup_read
,
5996 #ifdef CONFIG_SLABINFO
5998 .name
= "kmem.slabinfo",
5999 .read_seq_string
= mem_cgroup_slabinfo_read
,
6003 { }, /* terminate */
6006 #ifdef CONFIG_MEMCG_SWAP
6007 static struct cftype memsw_cgroup_files
[] = {
6009 .name
= "memsw.usage_in_bytes",
6010 .private = MEMFILE_PRIVATE(_MEMSWAP
, RES_USAGE
),
6011 .read
= mem_cgroup_read
,
6012 .register_event
= mem_cgroup_usage_register_event
,
6013 .unregister_event
= mem_cgroup_usage_unregister_event
,
6016 .name
= "memsw.max_usage_in_bytes",
6017 .private = MEMFILE_PRIVATE(_MEMSWAP
, RES_MAX_USAGE
),
6018 .trigger
= mem_cgroup_reset
,
6019 .read
= mem_cgroup_read
,
6022 .name
= "memsw.limit_in_bytes",
6023 .private = MEMFILE_PRIVATE(_MEMSWAP
, RES_LIMIT
),
6024 .write_string
= mem_cgroup_write
,
6025 .read
= mem_cgroup_read
,
6028 .name
= "memsw.failcnt",
6029 .private = MEMFILE_PRIVATE(_MEMSWAP
, RES_FAILCNT
),
6030 .trigger
= mem_cgroup_reset
,
6031 .read
= mem_cgroup_read
,
6033 { }, /* terminate */
6036 static int alloc_mem_cgroup_per_zone_info(struct mem_cgroup
*memcg
, int node
)
6038 struct mem_cgroup_per_node
*pn
;
6039 struct mem_cgroup_per_zone
*mz
;
6040 int zone
, tmp
= node
;
6042 * This routine is called against possible nodes.
6043 * But it's BUG to call kmalloc() against offline node.
6045 * TODO: this routine can waste much memory for nodes which will
6046 * never be onlined. It's better to use memory hotplug callback
6049 if (!node_state(node
, N_NORMAL_MEMORY
))
6051 pn
= kzalloc_node(sizeof(*pn
), GFP_KERNEL
, tmp
);
6055 for (zone
= 0; zone
< MAX_NR_ZONES
; zone
++) {
6056 mz
= &pn
->zoneinfo
[zone
];
6057 lruvec_init(&mz
->lruvec
);
6058 mz
->usage_in_excess
= 0;
6059 mz
->on_tree
= false;
6062 memcg
->info
.nodeinfo
[node
] = pn
;
6066 static void free_mem_cgroup_per_zone_info(struct mem_cgroup
*memcg
, int node
)
6068 kfree(memcg
->info
.nodeinfo
[node
]);
6071 static struct mem_cgroup
*mem_cgroup_alloc(void)
6073 struct mem_cgroup
*memcg
;
6074 size_t size
= memcg_size();
6076 /* Can be very big if nr_node_ids is very big */
6077 if (size
< PAGE_SIZE
)
6078 memcg
= kzalloc(size
, GFP_KERNEL
);
6080 memcg
= vzalloc(size
);
6085 memcg
->stat
= alloc_percpu(struct mem_cgroup_stat_cpu
);
6088 spin_lock_init(&memcg
->pcp_counter_lock
);
6092 if (size
< PAGE_SIZE
)
6100 * At destroying mem_cgroup, references from swap_cgroup can remain.
6101 * (scanning all at force_empty is too costly...)
6103 * Instead of clearing all references at force_empty, we remember
6104 * the number of reference from swap_cgroup and free mem_cgroup when
6105 * it goes down to 0.
6107 * Removal of cgroup itself succeeds regardless of refs from swap.
6110 static void __mem_cgroup_free(struct mem_cgroup
*memcg
)
6113 size_t size
= memcg_size();
6115 mem_cgroup_remove_from_trees(memcg
);
6116 free_css_id(&mem_cgroup_subsys
, &memcg
->css
);
6119 free_mem_cgroup_per_zone_info(memcg
, node
);
6121 free_percpu(memcg
->stat
);
6124 * We need to make sure that (at least for now), the jump label
6125 * destruction code runs outside of the cgroup lock. This is because
6126 * get_online_cpus(), which is called from the static_branch update,
6127 * can't be called inside the cgroup_lock. cpusets are the ones
6128 * enforcing this dependency, so if they ever change, we might as well.
6130 * schedule_work() will guarantee this happens. Be careful if you need
6131 * to move this code around, and make sure it is outside
6134 disarm_static_keys(memcg
);
6135 if (size
< PAGE_SIZE
)
6143 * Helpers for freeing a kmalloc()ed/vzalloc()ed mem_cgroup by RCU,
6144 * but in process context. The work_freeing structure is overlaid
6145 * on the rcu_freeing structure, which itself is overlaid on memsw.
6147 static void free_work(struct work_struct
*work
)
6149 struct mem_cgroup
*memcg
;
6151 memcg
= container_of(work
, struct mem_cgroup
, work_freeing
);
6152 __mem_cgroup_free(memcg
);
6155 static void free_rcu(struct rcu_head
*rcu_head
)
6157 struct mem_cgroup
*memcg
;
6159 memcg
= container_of(rcu_head
, struct mem_cgroup
, rcu_freeing
);
6160 INIT_WORK(&memcg
->work_freeing
, free_work
);
6161 schedule_work(&memcg
->work_freeing
);
6164 static void mem_cgroup_get(struct mem_cgroup
*memcg
)
6166 atomic_inc(&memcg
->refcnt
);
6169 static void __mem_cgroup_put(struct mem_cgroup
*memcg
, int count
)
6171 if (atomic_sub_and_test(count
, &memcg
->refcnt
)) {
6172 struct mem_cgroup
*parent
= parent_mem_cgroup(memcg
);
6173 call_rcu(&memcg
->rcu_freeing
, free_rcu
);
6175 mem_cgroup_put(parent
);
6179 static void mem_cgroup_put(struct mem_cgroup
*memcg
)
6181 __mem_cgroup_put(memcg
, 1);
6185 * Returns the parent mem_cgroup in memcgroup hierarchy with hierarchy enabled.
6187 struct mem_cgroup
*parent_mem_cgroup(struct mem_cgroup
*memcg
)
6189 if (!memcg
->res
.parent
)
6191 return mem_cgroup_from_res_counter(memcg
->res
.parent
, res
);
6193 EXPORT_SYMBOL(parent_mem_cgroup
);
6195 static void __init
mem_cgroup_soft_limit_tree_init(void)
6197 struct mem_cgroup_tree_per_node
*rtpn
;
6198 struct mem_cgroup_tree_per_zone
*rtpz
;
6199 int tmp
, node
, zone
;
6201 for_each_node(node
) {
6203 if (!node_state(node
, N_NORMAL_MEMORY
))
6205 rtpn
= kzalloc_node(sizeof(*rtpn
), GFP_KERNEL
, tmp
);
6208 soft_limit_tree
.rb_tree_per_node
[node
] = rtpn
;
6210 for (zone
= 0; zone
< MAX_NR_ZONES
; zone
++) {
6211 rtpz
= &rtpn
->rb_tree_per_zone
[zone
];
6212 rtpz
->rb_root
= RB_ROOT
;
6213 spin_lock_init(&rtpz
->lock
);
6218 static struct cgroup_subsys_state
* __ref
6219 mem_cgroup_css_alloc(struct cgroup
*cont
)
6221 struct mem_cgroup
*memcg
;
6222 long error
= -ENOMEM
;
6225 memcg
= mem_cgroup_alloc();
6227 return ERR_PTR(error
);
6230 if (alloc_mem_cgroup_per_zone_info(memcg
, node
))
6234 if (cont
->parent
== NULL
) {
6235 root_mem_cgroup
= memcg
;
6236 res_counter_init(&memcg
->res
, NULL
);
6237 res_counter_init(&memcg
->memsw
, NULL
);
6238 res_counter_init(&memcg
->kmem
, NULL
);
6241 memcg
->last_scanned_node
= MAX_NUMNODES
;
6242 INIT_LIST_HEAD(&memcg
->oom_notify
);
6243 atomic_set(&memcg
->refcnt
, 1);
6244 memcg
->move_charge_at_immigrate
= 0;
6245 mutex_init(&memcg
->thresholds_lock
);
6246 spin_lock_init(&memcg
->move_lock
);
6247 vmpressure_init(&memcg
->vmpressure
);
6252 __mem_cgroup_free(memcg
);
6253 return ERR_PTR(error
);
6257 mem_cgroup_css_online(struct cgroup
*cont
)
6259 struct mem_cgroup
*memcg
, *parent
;
6265 mutex_lock(&memcg_create_mutex
);
6266 memcg
= mem_cgroup_from_cont(cont
);
6267 parent
= mem_cgroup_from_cont(cont
->parent
);
6269 memcg
->use_hierarchy
= parent
->use_hierarchy
;
6270 memcg
->oom_kill_disable
= parent
->oom_kill_disable
;
6271 memcg
->swappiness
= mem_cgroup_swappiness(parent
);
6273 if (parent
->use_hierarchy
) {
6274 res_counter_init(&memcg
->res
, &parent
->res
);
6275 res_counter_init(&memcg
->memsw
, &parent
->memsw
);
6276 res_counter_init(&memcg
->kmem
, &parent
->kmem
);
6279 * We increment refcnt of the parent to ensure that we can
6280 * safely access it on res_counter_charge/uncharge.
6281 * This refcnt will be decremented when freeing this
6282 * mem_cgroup(see mem_cgroup_put).
6284 mem_cgroup_get(parent
);
6286 res_counter_init(&memcg
->res
, NULL
);
6287 res_counter_init(&memcg
->memsw
, NULL
);
6288 res_counter_init(&memcg
->kmem
, NULL
);
6290 * Deeper hierachy with use_hierarchy == false doesn't make
6291 * much sense so let cgroup subsystem know about this
6292 * unfortunate state in our controller.
6294 if (parent
!= root_mem_cgroup
)
6295 mem_cgroup_subsys
.broken_hierarchy
= true;
6298 error
= memcg_init_kmem(memcg
, &mem_cgroup_subsys
);
6299 mutex_unlock(&memcg_create_mutex
);
6302 * We call put now because our (and parent's) refcnts
6303 * are already in place. mem_cgroup_put() will internally
6304 * call __mem_cgroup_free, so return directly
6306 mem_cgroup_put(memcg
);
6307 if (parent
->use_hierarchy
)
6308 mem_cgroup_put(parent
);
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 atomic_inc(&parent
->dead_count
);
6324 * if the root memcg is not hierarchical we have to check it
6327 if (!root_mem_cgroup
->use_hierarchy
)
6328 atomic_inc(&root_mem_cgroup
->dead_count
);
6331 static void mem_cgroup_css_offline(struct cgroup
*cont
)
6333 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cont
);
6335 mem_cgroup_invalidate_reclaim_iterators(memcg
);
6336 mem_cgroup_reparent_charges(memcg
);
6337 mem_cgroup_destroy_all_caches(memcg
);
6340 static void mem_cgroup_css_free(struct cgroup
*cont
)
6342 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cont
);
6344 kmem_cgroup_destroy(memcg
);
6346 mem_cgroup_put(memcg
);
6350 /* Handlers for move charge at task migration. */
6351 #define PRECHARGE_COUNT_AT_ONCE 256
6352 static int mem_cgroup_do_precharge(unsigned long count
)
6355 int batch_count
= PRECHARGE_COUNT_AT_ONCE
;
6356 struct mem_cgroup
*memcg
= mc
.to
;
6358 if (mem_cgroup_is_root(memcg
)) {
6359 mc
.precharge
+= count
;
6360 /* we don't need css_get for root */
6363 /* try to charge at once */
6365 struct res_counter
*dummy
;
6367 * "memcg" cannot be under rmdir() because we've already checked
6368 * by cgroup_lock_live_cgroup() that it is not removed and we
6369 * are still under the same cgroup_mutex. So we can postpone
6372 if (res_counter_charge(&memcg
->res
, PAGE_SIZE
* count
, &dummy
))
6374 if (do_swap_account
&& res_counter_charge(&memcg
->memsw
,
6375 PAGE_SIZE
* count
, &dummy
)) {
6376 res_counter_uncharge(&memcg
->res
, PAGE_SIZE
* count
);
6379 mc
.precharge
+= count
;
6383 /* fall back to one by one charge */
6385 if (signal_pending(current
)) {
6389 if (!batch_count
--) {
6390 batch_count
= PRECHARGE_COUNT_AT_ONCE
;
6393 ret
= __mem_cgroup_try_charge(NULL
,
6394 GFP_KERNEL
, 1, &memcg
, false);
6396 /* mem_cgroup_clear_mc() will do uncharge later */
6404 * get_mctgt_type - get target type of moving charge
6405 * @vma: the vma the pte to be checked belongs
6406 * @addr: the address corresponding to the pte to be checked
6407 * @ptent: the pte to be checked
6408 * @target: the pointer the target page or swap ent will be stored(can be NULL)
6411 * 0(MC_TARGET_NONE): if the pte is not a target for move charge.
6412 * 1(MC_TARGET_PAGE): if the page corresponding to this pte is a target for
6413 * move charge. if @target is not NULL, the page is stored in target->page
6414 * with extra refcnt got(Callers should handle it).
6415 * 2(MC_TARGET_SWAP): if the swap entry corresponding to this pte is a
6416 * target for charge migration. if @target is not NULL, the entry is stored
6419 * Called with pte lock held.
6426 enum mc_target_type
{
6432 static struct page
*mc_handle_present_pte(struct vm_area_struct
*vma
,
6433 unsigned long addr
, pte_t ptent
)
6435 struct page
*page
= vm_normal_page(vma
, addr
, ptent
);
6437 if (!page
|| !page_mapped(page
))
6439 if (PageAnon(page
)) {
6440 /* we don't move shared anon */
6443 } else if (!move_file())
6444 /* we ignore mapcount for file pages */
6446 if (!get_page_unless_zero(page
))
6453 static struct page
*mc_handle_swap_pte(struct vm_area_struct
*vma
,
6454 unsigned long addr
, pte_t ptent
, swp_entry_t
*entry
)
6456 struct page
*page
= NULL
;
6457 swp_entry_t ent
= pte_to_swp_entry(ptent
);
6459 if (!move_anon() || non_swap_entry(ent
))
6462 * Because lookup_swap_cache() updates some statistics counter,
6463 * we call find_get_page() with swapper_space directly.
6465 page
= find_get_page(swap_address_space(ent
), ent
.val
);
6466 if (do_swap_account
)
6467 entry
->val
= ent
.val
;
6472 static struct page
*mc_handle_swap_pte(struct vm_area_struct
*vma
,
6473 unsigned long addr
, pte_t ptent
, swp_entry_t
*entry
)
6479 static struct page
*mc_handle_file_pte(struct vm_area_struct
*vma
,
6480 unsigned long addr
, pte_t ptent
, swp_entry_t
*entry
)
6482 struct page
*page
= NULL
;
6483 struct address_space
*mapping
;
6486 if (!vma
->vm_file
) /* anonymous vma */
6491 mapping
= vma
->vm_file
->f_mapping
;
6492 if (pte_none(ptent
))
6493 pgoff
= linear_page_index(vma
, addr
);
6494 else /* pte_file(ptent) is true */
6495 pgoff
= pte_to_pgoff(ptent
);
6497 /* page is moved even if it's not RSS of this task(page-faulted). */
6498 page
= find_get_page(mapping
, pgoff
);
6501 /* shmem/tmpfs may report page out on swap: account for that too. */
6502 if (radix_tree_exceptional_entry(page
)) {
6503 swp_entry_t swap
= radix_to_swp_entry(page
);
6504 if (do_swap_account
)
6506 page
= find_get_page(swap_address_space(swap
), swap
.val
);
6512 static enum mc_target_type
get_mctgt_type(struct vm_area_struct
*vma
,
6513 unsigned long addr
, pte_t ptent
, union mc_target
*target
)
6515 struct page
*page
= NULL
;
6516 struct page_cgroup
*pc
;
6517 enum mc_target_type ret
= MC_TARGET_NONE
;
6518 swp_entry_t ent
= { .val
= 0 };
6520 if (pte_present(ptent
))
6521 page
= mc_handle_present_pte(vma
, addr
, ptent
);
6522 else if (is_swap_pte(ptent
))
6523 page
= mc_handle_swap_pte(vma
, addr
, ptent
, &ent
);
6524 else if (pte_none(ptent
) || pte_file(ptent
))
6525 page
= mc_handle_file_pte(vma
, addr
, ptent
, &ent
);
6527 if (!page
&& !ent
.val
)
6530 pc
= lookup_page_cgroup(page
);
6532 * Do only loose check w/o page_cgroup lock.
6533 * mem_cgroup_move_account() checks the pc is valid or not under
6536 if (PageCgroupUsed(pc
) && pc
->mem_cgroup
== mc
.from
) {
6537 ret
= MC_TARGET_PAGE
;
6539 target
->page
= page
;
6541 if (!ret
|| !target
)
6544 /* There is a swap entry and a page doesn't exist or isn't charged */
6545 if (ent
.val
&& !ret
&&
6546 css_id(&mc
.from
->css
) == lookup_swap_cgroup_id(ent
)) {
6547 ret
= MC_TARGET_SWAP
;
6554 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
6556 * We don't consider swapping or file mapped pages because THP does not
6557 * support them for now.
6558 * Caller should make sure that pmd_trans_huge(pmd) is true.
6560 static enum mc_target_type
get_mctgt_type_thp(struct vm_area_struct
*vma
,
6561 unsigned long addr
, pmd_t pmd
, union mc_target
*target
)
6563 struct page
*page
= NULL
;
6564 struct page_cgroup
*pc
;
6565 enum mc_target_type ret
= MC_TARGET_NONE
;
6567 page
= pmd_page(pmd
);
6568 VM_BUG_ON(!page
|| !PageHead(page
));
6571 pc
= lookup_page_cgroup(page
);
6572 if (PageCgroupUsed(pc
) && pc
->mem_cgroup
== mc
.from
) {
6573 ret
= MC_TARGET_PAGE
;
6576 target
->page
= page
;
6582 static inline enum mc_target_type
get_mctgt_type_thp(struct vm_area_struct
*vma
,
6583 unsigned long addr
, pmd_t pmd
, union mc_target
*target
)
6585 return MC_TARGET_NONE
;
6589 static int mem_cgroup_count_precharge_pte_range(pmd_t
*pmd
,
6590 unsigned long addr
, unsigned long end
,
6591 struct mm_walk
*walk
)
6593 struct vm_area_struct
*vma
= walk
->private;
6597 if (pmd_trans_huge_lock(pmd
, vma
) == 1) {
6598 if (get_mctgt_type_thp(vma
, addr
, *pmd
, NULL
) == MC_TARGET_PAGE
)
6599 mc
.precharge
+= HPAGE_PMD_NR
;
6600 spin_unlock(&vma
->vm_mm
->page_table_lock
);
6604 if (pmd_trans_unstable(pmd
))
6606 pte
= pte_offset_map_lock(vma
->vm_mm
, pmd
, addr
, &ptl
);
6607 for (; addr
!= end
; pte
++, addr
+= PAGE_SIZE
)
6608 if (get_mctgt_type(vma
, addr
, *pte
, NULL
))
6609 mc
.precharge
++; /* increment precharge temporarily */
6610 pte_unmap_unlock(pte
- 1, ptl
);
6616 static unsigned long mem_cgroup_count_precharge(struct mm_struct
*mm
)
6618 unsigned long precharge
;
6619 struct vm_area_struct
*vma
;
6621 down_read(&mm
->mmap_sem
);
6622 for (vma
= mm
->mmap
; vma
; vma
= vma
->vm_next
) {
6623 struct mm_walk mem_cgroup_count_precharge_walk
= {
6624 .pmd_entry
= mem_cgroup_count_precharge_pte_range
,
6628 if (is_vm_hugetlb_page(vma
))
6630 walk_page_range(vma
->vm_start
, vma
->vm_end
,
6631 &mem_cgroup_count_precharge_walk
);
6633 up_read(&mm
->mmap_sem
);
6635 precharge
= mc
.precharge
;
6641 static int mem_cgroup_precharge_mc(struct mm_struct
*mm
)
6643 unsigned long precharge
= mem_cgroup_count_precharge(mm
);
6645 VM_BUG_ON(mc
.moving_task
);
6646 mc
.moving_task
= current
;
6647 return mem_cgroup_do_precharge(precharge
);
6650 /* cancels all extra charges on mc.from and mc.to, and wakes up all waiters. */
6651 static void __mem_cgroup_clear_mc(void)
6653 struct mem_cgroup
*from
= mc
.from
;
6654 struct mem_cgroup
*to
= mc
.to
;
6656 /* we must uncharge all the leftover precharges from mc.to */
6658 __mem_cgroup_cancel_charge(mc
.to
, mc
.precharge
);
6662 * we didn't uncharge from mc.from at mem_cgroup_move_account(), so
6663 * we must uncharge here.
6665 if (mc
.moved_charge
) {
6666 __mem_cgroup_cancel_charge(mc
.from
, mc
.moved_charge
);
6667 mc
.moved_charge
= 0;
6669 /* we must fixup refcnts and charges */
6670 if (mc
.moved_swap
) {
6671 /* uncharge swap account from the old cgroup */
6672 if (!mem_cgroup_is_root(mc
.from
))
6673 res_counter_uncharge(&mc
.from
->memsw
,
6674 PAGE_SIZE
* mc
.moved_swap
);
6675 __mem_cgroup_put(mc
.from
, mc
.moved_swap
);
6677 if (!mem_cgroup_is_root(mc
.to
)) {
6679 * we charged both to->res and to->memsw, so we should
6682 res_counter_uncharge(&mc
.to
->res
,
6683 PAGE_SIZE
* mc
.moved_swap
);
6685 /* we've already done mem_cgroup_get(mc.to) */
6688 memcg_oom_recover(from
);
6689 memcg_oom_recover(to
);
6690 wake_up_all(&mc
.waitq
);
6693 static void mem_cgroup_clear_mc(void)
6695 struct mem_cgroup
*from
= mc
.from
;
6698 * we must clear moving_task before waking up waiters at the end of
6701 mc
.moving_task
= NULL
;
6702 __mem_cgroup_clear_mc();
6703 spin_lock(&mc
.lock
);
6706 spin_unlock(&mc
.lock
);
6707 mem_cgroup_end_move(from
);
6710 static int mem_cgroup_can_attach(struct cgroup
*cgroup
,
6711 struct cgroup_taskset
*tset
)
6713 struct task_struct
*p
= cgroup_taskset_first(tset
);
6715 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cgroup
);
6716 unsigned long move_charge_at_immigrate
;
6719 * We are now commited to this value whatever it is. Changes in this
6720 * tunable will only affect upcoming migrations, not the current one.
6721 * So we need to save it, and keep it going.
6723 move_charge_at_immigrate
= memcg
->move_charge_at_immigrate
;
6724 if (move_charge_at_immigrate
) {
6725 struct mm_struct
*mm
;
6726 struct mem_cgroup
*from
= mem_cgroup_from_task(p
);
6728 VM_BUG_ON(from
== memcg
);
6730 mm
= get_task_mm(p
);
6733 /* We move charges only when we move a owner of the mm */
6734 if (mm
->owner
== p
) {
6737 VM_BUG_ON(mc
.precharge
);
6738 VM_BUG_ON(mc
.moved_charge
);
6739 VM_BUG_ON(mc
.moved_swap
);
6740 mem_cgroup_start_move(from
);
6741 spin_lock(&mc
.lock
);
6744 mc
.immigrate_flags
= move_charge_at_immigrate
;
6745 spin_unlock(&mc
.lock
);
6746 /* We set mc.moving_task later */
6748 ret
= mem_cgroup_precharge_mc(mm
);
6750 mem_cgroup_clear_mc();
6757 static void mem_cgroup_cancel_attach(struct cgroup
*cgroup
,
6758 struct cgroup_taskset
*tset
)
6760 mem_cgroup_clear_mc();
6763 static int mem_cgroup_move_charge_pte_range(pmd_t
*pmd
,
6764 unsigned long addr
, unsigned long end
,
6765 struct mm_walk
*walk
)
6768 struct vm_area_struct
*vma
= walk
->private;
6771 enum mc_target_type target_type
;
6772 union mc_target target
;
6774 struct page_cgroup
*pc
;
6777 * We don't take compound_lock() here but no race with splitting thp
6779 * - if pmd_trans_huge_lock() returns 1, the relevant thp is not
6780 * under splitting, which means there's no concurrent thp split,
6781 * - if another thread runs into split_huge_page() just after we
6782 * entered this if-block, the thread must wait for page table lock
6783 * to be unlocked in __split_huge_page_splitting(), where the main
6784 * part of thp split is not executed yet.
6786 if (pmd_trans_huge_lock(pmd
, vma
) == 1) {
6787 if (mc
.precharge
< HPAGE_PMD_NR
) {
6788 spin_unlock(&vma
->vm_mm
->page_table_lock
);
6791 target_type
= get_mctgt_type_thp(vma
, addr
, *pmd
, &target
);
6792 if (target_type
== MC_TARGET_PAGE
) {
6794 if (!isolate_lru_page(page
)) {
6795 pc
= lookup_page_cgroup(page
);
6796 if (!mem_cgroup_move_account(page
, HPAGE_PMD_NR
,
6797 pc
, mc
.from
, mc
.to
)) {
6798 mc
.precharge
-= HPAGE_PMD_NR
;
6799 mc
.moved_charge
+= HPAGE_PMD_NR
;
6801 putback_lru_page(page
);
6805 spin_unlock(&vma
->vm_mm
->page_table_lock
);
6809 if (pmd_trans_unstable(pmd
))
6812 pte
= pte_offset_map_lock(vma
->vm_mm
, pmd
, addr
, &ptl
);
6813 for (; addr
!= end
; addr
+= PAGE_SIZE
) {
6814 pte_t ptent
= *(pte
++);
6820 switch (get_mctgt_type(vma
, addr
, ptent
, &target
)) {
6821 case MC_TARGET_PAGE
:
6823 if (isolate_lru_page(page
))
6825 pc
= lookup_page_cgroup(page
);
6826 if (!mem_cgroup_move_account(page
, 1, pc
,
6829 /* we uncharge from mc.from later. */
6832 putback_lru_page(page
);
6833 put
: /* get_mctgt_type() gets the page */
6836 case MC_TARGET_SWAP
:
6838 if (!mem_cgroup_move_swap_account(ent
, mc
.from
, mc
.to
)) {
6840 /* we fixup refcnts and charges later. */
6848 pte_unmap_unlock(pte
- 1, ptl
);
6853 * We have consumed all precharges we got in can_attach().
6854 * We try charge one by one, but don't do any additional
6855 * charges to mc.to if we have failed in charge once in attach()
6858 ret
= mem_cgroup_do_precharge(1);
6866 static void mem_cgroup_move_charge(struct mm_struct
*mm
)
6868 struct vm_area_struct
*vma
;
6870 lru_add_drain_all();
6872 if (unlikely(!down_read_trylock(&mm
->mmap_sem
))) {
6874 * Someone who are holding the mmap_sem might be waiting in
6875 * waitq. So we cancel all extra charges, wake up all waiters,
6876 * and retry. Because we cancel precharges, we might not be able
6877 * to move enough charges, but moving charge is a best-effort
6878 * feature anyway, so it wouldn't be a big problem.
6880 __mem_cgroup_clear_mc();
6884 for (vma
= mm
->mmap
; vma
; vma
= vma
->vm_next
) {
6886 struct mm_walk mem_cgroup_move_charge_walk
= {
6887 .pmd_entry
= mem_cgroup_move_charge_pte_range
,
6891 if (is_vm_hugetlb_page(vma
))
6893 ret
= walk_page_range(vma
->vm_start
, vma
->vm_end
,
6894 &mem_cgroup_move_charge_walk
);
6897 * means we have consumed all precharges and failed in
6898 * doing additional charge. Just abandon here.
6902 up_read(&mm
->mmap_sem
);
6905 static void mem_cgroup_move_task(struct cgroup
*cont
,
6906 struct cgroup_taskset
*tset
)
6908 struct task_struct
*p
= cgroup_taskset_first(tset
);
6909 struct mm_struct
*mm
= get_task_mm(p
);
6913 mem_cgroup_move_charge(mm
);
6917 mem_cgroup_clear_mc();
6919 #else /* !CONFIG_MMU */
6920 static int mem_cgroup_can_attach(struct cgroup
*cgroup
,
6921 struct cgroup_taskset
*tset
)
6925 static void mem_cgroup_cancel_attach(struct cgroup
*cgroup
,
6926 struct cgroup_taskset
*tset
)
6929 static void mem_cgroup_move_task(struct cgroup
*cont
,
6930 struct cgroup_taskset
*tset
)
6936 * Cgroup retains root cgroups across [un]mount cycles making it necessary
6937 * to verify sane_behavior flag on each mount attempt.
6939 static void mem_cgroup_bind(struct cgroup
*root
)
6942 * use_hierarchy is forced with sane_behavior. cgroup core
6943 * guarantees that @root doesn't have any children, so turning it
6944 * on for the root memcg is enough.
6946 if (cgroup_sane_behavior(root
))
6947 mem_cgroup_from_cont(root
)->use_hierarchy
= true;
6950 struct cgroup_subsys mem_cgroup_subsys
= {
6952 .subsys_id
= mem_cgroup_subsys_id
,
6953 .css_alloc
= mem_cgroup_css_alloc
,
6954 .css_online
= mem_cgroup_css_online
,
6955 .css_offline
= mem_cgroup_css_offline
,
6956 .css_free
= mem_cgroup_css_free
,
6957 .can_attach
= mem_cgroup_can_attach
,
6958 .cancel_attach
= mem_cgroup_cancel_attach
,
6959 .attach
= mem_cgroup_move_task
,
6960 .bind
= mem_cgroup_bind
,
6961 .base_cftypes
= mem_cgroup_files
,
6966 #ifdef CONFIG_MEMCG_SWAP
6967 static int __init
enable_swap_account(char *s
)
6969 /* consider enabled if no parameter or 1 is given */
6970 if (!strcmp(s
, "1"))
6971 really_do_swap_account
= 1;
6972 else if (!strcmp(s
, "0"))
6973 really_do_swap_account
= 0;
6976 __setup("swapaccount=", enable_swap_account
);
6978 static void __init
memsw_file_init(void)
6980 WARN_ON(cgroup_add_cftypes(&mem_cgroup_subsys
, memsw_cgroup_files
));
6983 static void __init
enable_swap_cgroup(void)
6985 if (!mem_cgroup_disabled() && really_do_swap_account
) {
6986 do_swap_account
= 1;
6992 static void __init
enable_swap_cgroup(void)
6998 * subsys_initcall() for memory controller.
7000 * Some parts like hotcpu_notifier() have to be initialized from this context
7001 * because of lock dependencies (cgroup_lock -> cpu hotplug) but basically
7002 * everything that doesn't depend on a specific mem_cgroup structure should
7003 * be initialized from here.
7005 static int __init
mem_cgroup_init(void)
7007 hotcpu_notifier(memcg_cpu_hotplug_callback
, 0);
7008 enable_swap_cgroup();
7009 mem_cgroup_soft_limit_tree_init();
7013 subsys_initcall(mem_cgroup_init
);