1 /* memcontrol.c - Memory Controller
3 * Copyright IBM Corporation, 2007
4 * Author Balbir Singh <balbir@linux.vnet.ibm.com>
6 * Copyright 2007 OpenVZ SWsoft Inc
7 * Author: Pavel Emelianov <xemul@openvz.org>
10 * Copyright (C) 2009 Nokia Corporation
11 * Author: Kirill A. Shutemov
13 * Kernel Memory Controller
14 * Copyright (C) 2012 Parallels Inc. and Google Inc.
15 * Authors: Glauber Costa and Suleiman Souhlal
17 * This program is free software; you can redistribute it and/or modify
18 * it under the terms of the GNU General Public License as published by
19 * the Free Software Foundation; either version 2 of the License, or
20 * (at your option) any later version.
22 * This program is distributed in the hope that it will be useful,
23 * but WITHOUT ANY WARRANTY; without even the implied warranty of
24 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
25 * GNU General Public License for more details.
28 #include <linux/res_counter.h>
29 #include <linux/memcontrol.h>
30 #include <linux/cgroup.h>
32 #include <linux/hugetlb.h>
33 #include <linux/pagemap.h>
34 #include <linux/smp.h>
35 #include <linux/page-flags.h>
36 #include <linux/backing-dev.h>
37 #include <linux/bit_spinlock.h>
38 #include <linux/rcupdate.h>
39 #include <linux/limits.h>
40 #include <linux/export.h>
41 #include <linux/mutex.h>
42 #include <linux/rbtree.h>
43 #include <linux/slab.h>
44 #include <linux/swap.h>
45 #include <linux/swapops.h>
46 #include <linux/spinlock.h>
47 #include <linux/eventfd.h>
48 #include <linux/sort.h>
50 #include <linux/seq_file.h>
51 #include <linux/vmalloc.h>
52 #include <linux/vmpressure.h>
53 #include <linux/mm_inline.h>
54 #include <linux/page_cgroup.h>
55 #include <linux/cpu.h>
56 #include <linux/oom.h>
60 #include <net/tcp_memcontrol.h>
62 #include <asm/uaccess.h>
64 #include <trace/events/vmscan.h>
66 struct cgroup_subsys mem_cgroup_subsys __read_mostly
;
67 EXPORT_SYMBOL(mem_cgroup_subsys
);
69 #define MEM_CGROUP_RECLAIM_RETRIES 5
70 static struct mem_cgroup
*root_mem_cgroup __read_mostly
;
72 #ifdef CONFIG_MEMCG_SWAP
73 /* Turned on only when memory cgroup is enabled && really_do_swap_account = 1 */
74 int do_swap_account __read_mostly
;
76 /* for remember boot option*/
77 #ifdef CONFIG_MEMCG_SWAP_ENABLED
78 static int really_do_swap_account __initdata
= 1;
80 static int really_do_swap_account __initdata
= 0;
84 #define do_swap_account 0
89 * Statistics for memory cgroup.
91 enum mem_cgroup_stat_index
{
93 * For MEM_CONTAINER_TYPE_ALL, usage = pagecache + rss.
95 MEM_CGROUP_STAT_CACHE
, /* # of pages charged as cache */
96 MEM_CGROUP_STAT_RSS
, /* # of pages charged as anon rss */
97 MEM_CGROUP_STAT_RSS_HUGE
, /* # of pages charged as anon huge */
98 MEM_CGROUP_STAT_FILE_MAPPED
, /* # of pages charged as file rss */
99 MEM_CGROUP_STAT_SWAP
, /* # of pages, swapped out */
100 MEM_CGROUP_STAT_NSTATS
,
103 static const char * const mem_cgroup_stat_names
[] = {
111 enum mem_cgroup_events_index
{
112 MEM_CGROUP_EVENTS_PGPGIN
, /* # of pages paged in */
113 MEM_CGROUP_EVENTS_PGPGOUT
, /* # of pages paged out */
114 MEM_CGROUP_EVENTS_PGFAULT
, /* # of page-faults */
115 MEM_CGROUP_EVENTS_PGMAJFAULT
, /* # of major page-faults */
116 MEM_CGROUP_EVENTS_NSTATS
,
119 static const char * const mem_cgroup_events_names
[] = {
126 static const char * const mem_cgroup_lru_names
[] = {
135 * Per memcg event counter is incremented at every pagein/pageout. With THP,
136 * it will be incremated by the number of pages. This counter is used for
137 * for trigger some periodic events. This is straightforward and better
138 * than using jiffies etc. to handle periodic memcg event.
140 enum mem_cgroup_events_target
{
141 MEM_CGROUP_TARGET_THRESH
,
142 MEM_CGROUP_TARGET_SOFTLIMIT
,
143 MEM_CGROUP_TARGET_NUMAINFO
,
146 #define THRESHOLDS_EVENTS_TARGET 128
147 #define SOFTLIMIT_EVENTS_TARGET 1024
148 #define NUMAINFO_EVENTS_TARGET 1024
150 struct mem_cgroup_stat_cpu
{
151 long count
[MEM_CGROUP_STAT_NSTATS
];
152 unsigned long events
[MEM_CGROUP_EVENTS_NSTATS
];
153 unsigned long nr_page_events
;
154 unsigned long targets
[MEM_CGROUP_NTARGETS
];
157 struct mem_cgroup_reclaim_iter
{
159 * last scanned hierarchy member. Valid only if last_dead_count
160 * matches memcg->dead_count of the hierarchy root group.
162 struct mem_cgroup
*last_visited
;
163 unsigned long last_dead_count
;
165 /* scan generation, increased every round-trip */
166 unsigned int generation
;
170 * per-zone information in memory controller.
172 struct mem_cgroup_per_zone
{
173 struct lruvec lruvec
;
174 unsigned long lru_size
[NR_LRU_LISTS
];
176 struct mem_cgroup_reclaim_iter reclaim_iter
[DEF_PRIORITY
+ 1];
178 struct rb_node tree_node
; /* RB tree node */
179 unsigned long long usage_in_excess
;/* Set to the value by which */
180 /* the soft limit is exceeded*/
182 struct mem_cgroup
*memcg
; /* Back pointer, we cannot */
183 /* use container_of */
186 struct mem_cgroup_per_node
{
187 struct mem_cgroup_per_zone zoneinfo
[MAX_NR_ZONES
];
191 * Cgroups above their limits are maintained in a RB-Tree, independent of
192 * their hierarchy representation
195 struct mem_cgroup_tree_per_zone
{
196 struct rb_root rb_root
;
200 struct mem_cgroup_tree_per_node
{
201 struct mem_cgroup_tree_per_zone rb_tree_per_zone
[MAX_NR_ZONES
];
204 struct mem_cgroup_tree
{
205 struct mem_cgroup_tree_per_node
*rb_tree_per_node
[MAX_NUMNODES
];
208 static struct mem_cgroup_tree soft_limit_tree __read_mostly
;
210 struct mem_cgroup_threshold
{
211 struct eventfd_ctx
*eventfd
;
216 struct mem_cgroup_threshold_ary
{
217 /* An array index points to threshold just below or equal to usage. */
218 int current_threshold
;
219 /* Size of entries[] */
221 /* Array of thresholds */
222 struct mem_cgroup_threshold entries
[0];
225 struct mem_cgroup_thresholds
{
226 /* Primary thresholds array */
227 struct mem_cgroup_threshold_ary
*primary
;
229 * Spare threshold array.
230 * This is needed to make mem_cgroup_unregister_event() "never fail".
231 * It must be able to store at least primary->size - 1 entries.
233 struct mem_cgroup_threshold_ary
*spare
;
237 struct mem_cgroup_eventfd_list
{
238 struct list_head list
;
239 struct eventfd_ctx
*eventfd
;
242 static void mem_cgroup_threshold(struct mem_cgroup
*memcg
);
243 static void mem_cgroup_oom_notify(struct mem_cgroup
*memcg
);
246 * The memory controller data structure. The memory controller controls both
247 * page cache and RSS per cgroup. We would eventually like to provide
248 * statistics based on the statistics developed by Rik Van Riel for clock-pro,
249 * to help the administrator determine what knobs to tune.
251 * TODO: Add a water mark for the memory controller. Reclaim will begin when
252 * we hit the water mark. May be even add a low water mark, such that
253 * no reclaim occurs from a cgroup at it's low water mark, this is
254 * a feature that will be implemented much later in the future.
257 struct cgroup_subsys_state css
;
259 * the counter to account for memory usage
261 struct res_counter res
;
263 /* vmpressure notifications */
264 struct vmpressure vmpressure
;
268 * the counter to account for mem+swap usage.
270 struct res_counter memsw
;
273 * rcu_freeing is used only when freeing struct mem_cgroup,
274 * so put it into a union to avoid wasting more memory.
275 * It must be disjoint from the css field. It could be
276 * in a union with the res field, but res plays a much
277 * larger part in mem_cgroup life than memsw, and might
278 * be of interest, even at time of free, when debugging.
279 * So share rcu_head with the less interesting memsw.
281 struct rcu_head rcu_freeing
;
283 * We also need some space for a worker in deferred freeing.
284 * By the time we call it, rcu_freeing is no longer in use.
286 struct work_struct work_freeing
;
290 * the counter to account for kernel memory usage.
292 struct res_counter kmem
;
294 * Should the accounting and control be hierarchical, per subtree?
297 unsigned long kmem_account_flags
; /* See KMEM_ACCOUNTED_*, below */
305 /* OOM-Killer disable */
306 int oom_kill_disable
;
308 /* set when res.limit == memsw.limit */
309 bool memsw_is_minimum
;
311 /* protect arrays of thresholds */
312 struct mutex thresholds_lock
;
314 /* thresholds for memory usage. RCU-protected */
315 struct mem_cgroup_thresholds thresholds
;
317 /* thresholds for mem+swap usage. RCU-protected */
318 struct mem_cgroup_thresholds memsw_thresholds
;
320 /* For oom notifier event fd */
321 struct list_head oom_notify
;
324 * Should we move charges of a task when a task is moved into this
325 * mem_cgroup ? And what type of charges should we move ?
327 unsigned long move_charge_at_immigrate
;
329 * set > 0 if pages under this cgroup are moving to other cgroup.
331 atomic_t moving_account
;
332 /* taken only while moving_account > 0 */
333 spinlock_t move_lock
;
337 struct mem_cgroup_stat_cpu __percpu
*stat
;
339 * used when a cpu is offlined or other synchronizations
340 * See mem_cgroup_read_stat().
342 struct mem_cgroup_stat_cpu nocpu_base
;
343 spinlock_t pcp_counter_lock
;
346 #if defined(CONFIG_MEMCG_KMEM) && defined(CONFIG_INET)
347 struct tcp_memcontrol tcp_mem
;
349 #if defined(CONFIG_MEMCG_KMEM)
350 /* analogous to slab_common's slab_caches list. per-memcg */
351 struct list_head memcg_slab_caches
;
352 /* Not a spinlock, we can take a lot of time walking the list */
353 struct mutex slab_caches_mutex
;
354 /* Index in the kmem_cache->memcg_params->memcg_caches array */
358 int last_scanned_node
;
360 nodemask_t scan_nodes
;
361 atomic_t numainfo_events
;
362 atomic_t numainfo_updating
;
365 struct mem_cgroup_per_node
*nodeinfo
[0];
366 /* WARNING: nodeinfo must be the last member here */
369 static size_t memcg_size(void)
371 return sizeof(struct mem_cgroup
) +
372 nr_node_ids
* sizeof(struct mem_cgroup_per_node
);
375 /* internal only representation about the status of kmem accounting. */
377 KMEM_ACCOUNTED_ACTIVE
= 0, /* accounted by this cgroup itself */
378 KMEM_ACCOUNTED_ACTIVATED
, /* static key enabled. */
379 KMEM_ACCOUNTED_DEAD
, /* dead memcg with pending kmem charges */
382 /* We account when limit is on, but only after call sites are patched */
383 #define KMEM_ACCOUNTED_MASK \
384 ((1 << KMEM_ACCOUNTED_ACTIVE) | (1 << KMEM_ACCOUNTED_ACTIVATED))
386 #ifdef CONFIG_MEMCG_KMEM
387 static inline void memcg_kmem_set_active(struct mem_cgroup
*memcg
)
389 set_bit(KMEM_ACCOUNTED_ACTIVE
, &memcg
->kmem_account_flags
);
392 static bool memcg_kmem_is_active(struct mem_cgroup
*memcg
)
394 return test_bit(KMEM_ACCOUNTED_ACTIVE
, &memcg
->kmem_account_flags
);
397 static void memcg_kmem_set_activated(struct mem_cgroup
*memcg
)
399 set_bit(KMEM_ACCOUNTED_ACTIVATED
, &memcg
->kmem_account_flags
);
402 static void memcg_kmem_clear_activated(struct mem_cgroup
*memcg
)
404 clear_bit(KMEM_ACCOUNTED_ACTIVATED
, &memcg
->kmem_account_flags
);
407 static void memcg_kmem_mark_dead(struct mem_cgroup
*memcg
)
410 * Our caller must use css_get() first, because memcg_uncharge_kmem()
411 * will call css_put() if it sees the memcg is dead.
414 if (test_bit(KMEM_ACCOUNTED_ACTIVE
, &memcg
->kmem_account_flags
))
415 set_bit(KMEM_ACCOUNTED_DEAD
, &memcg
->kmem_account_flags
);
418 static bool memcg_kmem_test_and_clear_dead(struct mem_cgroup
*memcg
)
420 return test_and_clear_bit(KMEM_ACCOUNTED_DEAD
,
421 &memcg
->kmem_account_flags
);
425 /* Stuffs for move charges at task migration. */
427 * Types of charges to be moved. "move_charge_at_immitgrate" and
428 * "immigrate_flags" are treated as a left-shifted bitmap of these types.
431 MOVE_CHARGE_TYPE_ANON
, /* private anonymous page and swap of it */
432 MOVE_CHARGE_TYPE_FILE
, /* file page(including tmpfs) and swap of it */
436 /* "mc" and its members are protected by cgroup_mutex */
437 static struct move_charge_struct
{
438 spinlock_t lock
; /* for from, to */
439 struct mem_cgroup
*from
;
440 struct mem_cgroup
*to
;
441 unsigned long immigrate_flags
;
442 unsigned long precharge
;
443 unsigned long moved_charge
;
444 unsigned long moved_swap
;
445 struct task_struct
*moving_task
; /* a task moving charges */
446 wait_queue_head_t waitq
; /* a waitq for other context */
448 .lock
= __SPIN_LOCK_UNLOCKED(mc
.lock
),
449 .waitq
= __WAIT_QUEUE_HEAD_INITIALIZER(mc
.waitq
),
452 static bool move_anon(void)
454 return test_bit(MOVE_CHARGE_TYPE_ANON
, &mc
.immigrate_flags
);
457 static bool move_file(void)
459 return test_bit(MOVE_CHARGE_TYPE_FILE
, &mc
.immigrate_flags
);
463 * Maximum loops in mem_cgroup_hierarchical_reclaim(), used for soft
464 * limit reclaim to prevent infinite loops, if they ever occur.
466 #define MEM_CGROUP_MAX_RECLAIM_LOOPS 100
467 #define MEM_CGROUP_MAX_SOFT_LIMIT_RECLAIM_LOOPS 2
470 MEM_CGROUP_CHARGE_TYPE_CACHE
= 0,
471 MEM_CGROUP_CHARGE_TYPE_ANON
,
472 MEM_CGROUP_CHARGE_TYPE_SWAPOUT
, /* for accounting swapcache */
473 MEM_CGROUP_CHARGE_TYPE_DROP
, /* a page was unused swap cache */
477 /* for encoding cft->private value on file */
485 #define MEMFILE_PRIVATE(x, val) ((x) << 16 | (val))
486 #define MEMFILE_TYPE(val) ((val) >> 16 & 0xffff)
487 #define MEMFILE_ATTR(val) ((val) & 0xffff)
488 /* Used for OOM nofiier */
489 #define OOM_CONTROL (0)
492 * Reclaim flags for mem_cgroup_hierarchical_reclaim
494 #define MEM_CGROUP_RECLAIM_NOSWAP_BIT 0x0
495 #define MEM_CGROUP_RECLAIM_NOSWAP (1 << MEM_CGROUP_RECLAIM_NOSWAP_BIT)
496 #define MEM_CGROUP_RECLAIM_SHRINK_BIT 0x1
497 #define MEM_CGROUP_RECLAIM_SHRINK (1 << MEM_CGROUP_RECLAIM_SHRINK_BIT)
500 * The memcg_create_mutex will be held whenever a new cgroup is created.
501 * As a consequence, any change that needs to protect against new child cgroups
502 * appearing has to hold it as well.
504 static DEFINE_MUTEX(memcg_create_mutex
);
506 static void mem_cgroup_get(struct mem_cgroup
*memcg
);
507 static void mem_cgroup_put(struct mem_cgroup
*memcg
);
510 struct mem_cgroup
*mem_cgroup_from_css(struct cgroup_subsys_state
*s
)
512 return container_of(s
, struct mem_cgroup
, css
);
515 /* Some nice accessors for the vmpressure. */
516 struct vmpressure
*memcg_to_vmpressure(struct mem_cgroup
*memcg
)
519 memcg
= root_mem_cgroup
;
520 return &memcg
->vmpressure
;
523 struct cgroup_subsys_state
*vmpressure_to_css(struct vmpressure
*vmpr
)
525 return &container_of(vmpr
, struct mem_cgroup
, vmpressure
)->css
;
528 struct vmpressure
*css_to_vmpressure(struct cgroup_subsys_state
*css
)
530 return &mem_cgroup_from_css(css
)->vmpressure
;
533 static inline bool mem_cgroup_is_root(struct mem_cgroup
*memcg
)
535 return (memcg
== root_mem_cgroup
);
538 /* Writing them here to avoid exposing memcg's inner layout */
539 #if defined(CONFIG_INET) && defined(CONFIG_MEMCG_KMEM)
541 void sock_update_memcg(struct sock
*sk
)
543 if (mem_cgroup_sockets_enabled
) {
544 struct mem_cgroup
*memcg
;
545 struct cg_proto
*cg_proto
;
547 BUG_ON(!sk
->sk_prot
->proto_cgroup
);
549 /* Socket cloning can throw us here with sk_cgrp already
550 * filled. It won't however, necessarily happen from
551 * process context. So the test for root memcg given
552 * the current task's memcg won't help us in this case.
554 * Respecting the original socket's memcg is a better
555 * decision in this case.
558 BUG_ON(mem_cgroup_is_root(sk
->sk_cgrp
->memcg
));
559 css_get(&sk
->sk_cgrp
->memcg
->css
);
564 memcg
= mem_cgroup_from_task(current
);
565 cg_proto
= sk
->sk_prot
->proto_cgroup(memcg
);
566 if (!mem_cgroup_is_root(memcg
) &&
567 memcg_proto_active(cg_proto
) && css_tryget(&memcg
->css
)) {
568 sk
->sk_cgrp
= cg_proto
;
573 EXPORT_SYMBOL(sock_update_memcg
);
575 void sock_release_memcg(struct sock
*sk
)
577 if (mem_cgroup_sockets_enabled
&& sk
->sk_cgrp
) {
578 struct mem_cgroup
*memcg
;
579 WARN_ON(!sk
->sk_cgrp
->memcg
);
580 memcg
= sk
->sk_cgrp
->memcg
;
581 css_put(&sk
->sk_cgrp
->memcg
->css
);
585 struct cg_proto
*tcp_proto_cgroup(struct mem_cgroup
*memcg
)
587 if (!memcg
|| mem_cgroup_is_root(memcg
))
590 return &memcg
->tcp_mem
.cg_proto
;
592 EXPORT_SYMBOL(tcp_proto_cgroup
);
594 static void disarm_sock_keys(struct mem_cgroup
*memcg
)
596 if (!memcg_proto_activated(&memcg
->tcp_mem
.cg_proto
))
598 static_key_slow_dec(&memcg_socket_limit_enabled
);
601 static void disarm_sock_keys(struct mem_cgroup
*memcg
)
606 #ifdef CONFIG_MEMCG_KMEM
608 * This will be the memcg's index in each cache's ->memcg_params->memcg_caches.
609 * There are two main reasons for not using the css_id for this:
610 * 1) this works better in sparse environments, where we have a lot of memcgs,
611 * but only a few kmem-limited. Or also, if we have, for instance, 200
612 * memcgs, and none but the 200th is kmem-limited, we'd have to have a
613 * 200 entry array for that.
615 * 2) In order not to violate the cgroup API, we would like to do all memory
616 * allocation in ->create(). At that point, we haven't yet allocated the
617 * css_id. Having a separate index prevents us from messing with the cgroup
620 * The current size of the caches array is stored in
621 * memcg_limited_groups_array_size. It will double each time we have to
624 static DEFINE_IDA(kmem_limited_groups
);
625 int memcg_limited_groups_array_size
;
628 * MIN_SIZE is different than 1, because we would like to avoid going through
629 * the alloc/free process all the time. In a small machine, 4 kmem-limited
630 * cgroups is a reasonable guess. In the future, it could be a parameter or
631 * tunable, but that is strictly not necessary.
633 * MAX_SIZE should be as large as the number of css_ids. Ideally, we could get
634 * this constant directly from cgroup, but it is understandable that this is
635 * better kept as an internal representation in cgroup.c. In any case, the
636 * css_id space is not getting any smaller, and we don't have to necessarily
637 * increase ours as well if it increases.
639 #define MEMCG_CACHES_MIN_SIZE 4
640 #define MEMCG_CACHES_MAX_SIZE 65535
643 * A lot of the calls to the cache allocation functions are expected to be
644 * inlined by the compiler. Since the calls to memcg_kmem_get_cache are
645 * conditional to this static branch, we'll have to allow modules that does
646 * kmem_cache_alloc and the such to see this symbol as well
648 struct static_key memcg_kmem_enabled_key
;
649 EXPORT_SYMBOL(memcg_kmem_enabled_key
);
651 static void disarm_kmem_keys(struct mem_cgroup
*memcg
)
653 if (memcg_kmem_is_active(memcg
)) {
654 static_key_slow_dec(&memcg_kmem_enabled_key
);
655 ida_simple_remove(&kmem_limited_groups
, memcg
->kmemcg_id
);
658 * This check can't live in kmem destruction function,
659 * since the charges will outlive the cgroup
661 WARN_ON(res_counter_read_u64(&memcg
->kmem
, RES_USAGE
) != 0);
664 static void disarm_kmem_keys(struct mem_cgroup
*memcg
)
667 #endif /* CONFIG_MEMCG_KMEM */
669 static void disarm_static_keys(struct mem_cgroup
*memcg
)
671 disarm_sock_keys(memcg
);
672 disarm_kmem_keys(memcg
);
675 static void drain_all_stock_async(struct mem_cgroup
*memcg
);
677 static struct mem_cgroup_per_zone
*
678 mem_cgroup_zoneinfo(struct mem_cgroup
*memcg
, int nid
, int zid
)
680 VM_BUG_ON((unsigned)nid
>= nr_node_ids
);
681 return &memcg
->nodeinfo
[nid
]->zoneinfo
[zid
];
684 struct cgroup_subsys_state
*mem_cgroup_css(struct mem_cgroup
*memcg
)
689 static struct mem_cgroup_per_zone
*
690 page_cgroup_zoneinfo(struct mem_cgroup
*memcg
, struct page
*page
)
692 int nid
= page_to_nid(page
);
693 int zid
= page_zonenum(page
);
695 return mem_cgroup_zoneinfo(memcg
, nid
, zid
);
698 static struct mem_cgroup_tree_per_zone
*
699 soft_limit_tree_node_zone(int nid
, int zid
)
701 return &soft_limit_tree
.rb_tree_per_node
[nid
]->rb_tree_per_zone
[zid
];
704 static struct mem_cgroup_tree_per_zone
*
705 soft_limit_tree_from_page(struct page
*page
)
707 int nid
= page_to_nid(page
);
708 int zid
= page_zonenum(page
);
710 return &soft_limit_tree
.rb_tree_per_node
[nid
]->rb_tree_per_zone
[zid
];
714 __mem_cgroup_insert_exceeded(struct mem_cgroup
*memcg
,
715 struct mem_cgroup_per_zone
*mz
,
716 struct mem_cgroup_tree_per_zone
*mctz
,
717 unsigned long long new_usage_in_excess
)
719 struct rb_node
**p
= &mctz
->rb_root
.rb_node
;
720 struct rb_node
*parent
= NULL
;
721 struct mem_cgroup_per_zone
*mz_node
;
726 mz
->usage_in_excess
= new_usage_in_excess
;
727 if (!mz
->usage_in_excess
)
731 mz_node
= rb_entry(parent
, struct mem_cgroup_per_zone
,
733 if (mz
->usage_in_excess
< mz_node
->usage_in_excess
)
736 * We can't avoid mem cgroups that are over their soft
737 * limit by the same amount
739 else if (mz
->usage_in_excess
>= mz_node
->usage_in_excess
)
742 rb_link_node(&mz
->tree_node
, parent
, p
);
743 rb_insert_color(&mz
->tree_node
, &mctz
->rb_root
);
748 __mem_cgroup_remove_exceeded(struct mem_cgroup
*memcg
,
749 struct mem_cgroup_per_zone
*mz
,
750 struct mem_cgroup_tree_per_zone
*mctz
)
754 rb_erase(&mz
->tree_node
, &mctz
->rb_root
);
759 mem_cgroup_remove_exceeded(struct mem_cgroup
*memcg
,
760 struct mem_cgroup_per_zone
*mz
,
761 struct mem_cgroup_tree_per_zone
*mctz
)
763 spin_lock(&mctz
->lock
);
764 __mem_cgroup_remove_exceeded(memcg
, mz
, mctz
);
765 spin_unlock(&mctz
->lock
);
769 static void mem_cgroup_update_tree(struct mem_cgroup
*memcg
, struct page
*page
)
771 unsigned long long excess
;
772 struct mem_cgroup_per_zone
*mz
;
773 struct mem_cgroup_tree_per_zone
*mctz
;
774 int nid
= page_to_nid(page
);
775 int zid
= page_zonenum(page
);
776 mctz
= soft_limit_tree_from_page(page
);
779 * Necessary to update all ancestors when hierarchy is used.
780 * because their event counter is not touched.
782 for (; memcg
; memcg
= parent_mem_cgroup(memcg
)) {
783 mz
= mem_cgroup_zoneinfo(memcg
, nid
, zid
);
784 excess
= res_counter_soft_limit_excess(&memcg
->res
);
786 * We have to update the tree if mz is on RB-tree or
787 * mem is over its softlimit.
789 if (excess
|| mz
->on_tree
) {
790 spin_lock(&mctz
->lock
);
791 /* if on-tree, remove it */
793 __mem_cgroup_remove_exceeded(memcg
, mz
, mctz
);
795 * Insert again. mz->usage_in_excess will be updated.
796 * If excess is 0, no tree ops.
798 __mem_cgroup_insert_exceeded(memcg
, mz
, mctz
, excess
);
799 spin_unlock(&mctz
->lock
);
804 static void mem_cgroup_remove_from_trees(struct mem_cgroup
*memcg
)
807 struct mem_cgroup_per_zone
*mz
;
808 struct mem_cgroup_tree_per_zone
*mctz
;
810 for_each_node(node
) {
811 for (zone
= 0; zone
< MAX_NR_ZONES
; zone
++) {
812 mz
= mem_cgroup_zoneinfo(memcg
, node
, zone
);
813 mctz
= soft_limit_tree_node_zone(node
, zone
);
814 mem_cgroup_remove_exceeded(memcg
, mz
, mctz
);
819 static struct mem_cgroup_per_zone
*
820 __mem_cgroup_largest_soft_limit_node(struct mem_cgroup_tree_per_zone
*mctz
)
822 struct rb_node
*rightmost
= NULL
;
823 struct mem_cgroup_per_zone
*mz
;
827 rightmost
= rb_last(&mctz
->rb_root
);
829 goto done
; /* Nothing to reclaim from */
831 mz
= rb_entry(rightmost
, struct mem_cgroup_per_zone
, tree_node
);
833 * Remove the node now but someone else can add it back,
834 * we will to add it back at the end of reclaim to its correct
835 * position in the tree.
837 __mem_cgroup_remove_exceeded(mz
->memcg
, mz
, mctz
);
838 if (!res_counter_soft_limit_excess(&mz
->memcg
->res
) ||
839 !css_tryget(&mz
->memcg
->css
))
845 static struct mem_cgroup_per_zone
*
846 mem_cgroup_largest_soft_limit_node(struct mem_cgroup_tree_per_zone
*mctz
)
848 struct mem_cgroup_per_zone
*mz
;
850 spin_lock(&mctz
->lock
);
851 mz
= __mem_cgroup_largest_soft_limit_node(mctz
);
852 spin_unlock(&mctz
->lock
);
857 * Implementation Note: reading percpu statistics for memcg.
859 * Both of vmstat[] and percpu_counter has threshold and do periodic
860 * synchronization to implement "quick" read. There are trade-off between
861 * reading cost and precision of value. Then, we may have a chance to implement
862 * a periodic synchronizion of counter in memcg's counter.
864 * But this _read() function is used for user interface now. The user accounts
865 * memory usage by memory cgroup and he _always_ requires exact value because
866 * he accounts memory. Even if we provide quick-and-fuzzy read, we always
867 * have to visit all online cpus and make sum. So, for now, unnecessary
868 * synchronization is not implemented. (just implemented for cpu hotplug)
870 * If there are kernel internal actions which can make use of some not-exact
871 * value, and reading all cpu value can be performance bottleneck in some
872 * common workload, threashold and synchonization as vmstat[] should be
875 static long mem_cgroup_read_stat(struct mem_cgroup
*memcg
,
876 enum mem_cgroup_stat_index idx
)
882 for_each_online_cpu(cpu
)
883 val
+= per_cpu(memcg
->stat
->count
[idx
], cpu
);
884 #ifdef CONFIG_HOTPLUG_CPU
885 spin_lock(&memcg
->pcp_counter_lock
);
886 val
+= memcg
->nocpu_base
.count
[idx
];
887 spin_unlock(&memcg
->pcp_counter_lock
);
893 static void mem_cgroup_swap_statistics(struct mem_cgroup
*memcg
,
896 int val
= (charge
) ? 1 : -1;
897 this_cpu_add(memcg
->stat
->count
[MEM_CGROUP_STAT_SWAP
], val
);
900 static unsigned long mem_cgroup_read_events(struct mem_cgroup
*memcg
,
901 enum mem_cgroup_events_index idx
)
903 unsigned long val
= 0;
906 for_each_online_cpu(cpu
)
907 val
+= per_cpu(memcg
->stat
->events
[idx
], cpu
);
908 #ifdef CONFIG_HOTPLUG_CPU
909 spin_lock(&memcg
->pcp_counter_lock
);
910 val
+= memcg
->nocpu_base
.events
[idx
];
911 spin_unlock(&memcg
->pcp_counter_lock
);
916 static void mem_cgroup_charge_statistics(struct mem_cgroup
*memcg
,
918 bool anon
, int nr_pages
)
923 * Here, RSS means 'mapped anon' and anon's SwapCache. Shmem/tmpfs is
924 * counted as CACHE even if it's on ANON LRU.
927 __this_cpu_add(memcg
->stat
->count
[MEM_CGROUP_STAT_RSS
],
930 __this_cpu_add(memcg
->stat
->count
[MEM_CGROUP_STAT_CACHE
],
933 if (PageTransHuge(page
))
934 __this_cpu_add(memcg
->stat
->count
[MEM_CGROUP_STAT_RSS_HUGE
],
937 /* pagein of a big page is an event. So, ignore page size */
939 __this_cpu_inc(memcg
->stat
->events
[MEM_CGROUP_EVENTS_PGPGIN
]);
941 __this_cpu_inc(memcg
->stat
->events
[MEM_CGROUP_EVENTS_PGPGOUT
]);
942 nr_pages
= -nr_pages
; /* for event */
945 __this_cpu_add(memcg
->stat
->nr_page_events
, nr_pages
);
951 mem_cgroup_get_lru_size(struct lruvec
*lruvec
, enum lru_list lru
)
953 struct mem_cgroup_per_zone
*mz
;
955 mz
= container_of(lruvec
, struct mem_cgroup_per_zone
, lruvec
);
956 return mz
->lru_size
[lru
];
960 mem_cgroup_zone_nr_lru_pages(struct mem_cgroup
*memcg
, int nid
, int zid
,
961 unsigned int lru_mask
)
963 struct mem_cgroup_per_zone
*mz
;
965 unsigned long ret
= 0;
967 mz
= mem_cgroup_zoneinfo(memcg
, nid
, zid
);
970 if (BIT(lru
) & lru_mask
)
971 ret
+= mz
->lru_size
[lru
];
977 mem_cgroup_node_nr_lru_pages(struct mem_cgroup
*memcg
,
978 int nid
, unsigned int lru_mask
)
983 for (zid
= 0; zid
< MAX_NR_ZONES
; zid
++)
984 total
+= mem_cgroup_zone_nr_lru_pages(memcg
,
990 static unsigned long mem_cgroup_nr_lru_pages(struct mem_cgroup
*memcg
,
991 unsigned int lru_mask
)
996 for_each_node_state(nid
, N_MEMORY
)
997 total
+= mem_cgroup_node_nr_lru_pages(memcg
, nid
, lru_mask
);
1001 static bool mem_cgroup_event_ratelimit(struct mem_cgroup
*memcg
,
1002 enum mem_cgroup_events_target target
)
1004 unsigned long val
, next
;
1006 val
= __this_cpu_read(memcg
->stat
->nr_page_events
);
1007 next
= __this_cpu_read(memcg
->stat
->targets
[target
]);
1008 /* from time_after() in jiffies.h */
1009 if ((long)next
- (long)val
< 0) {
1011 case MEM_CGROUP_TARGET_THRESH
:
1012 next
= val
+ THRESHOLDS_EVENTS_TARGET
;
1014 case MEM_CGROUP_TARGET_SOFTLIMIT
:
1015 next
= val
+ SOFTLIMIT_EVENTS_TARGET
;
1017 case MEM_CGROUP_TARGET_NUMAINFO
:
1018 next
= val
+ NUMAINFO_EVENTS_TARGET
;
1023 __this_cpu_write(memcg
->stat
->targets
[target
], next
);
1030 * Check events in order.
1033 static void memcg_check_events(struct mem_cgroup
*memcg
, struct page
*page
)
1036 /* threshold event is triggered in finer grain than soft limit */
1037 if (unlikely(mem_cgroup_event_ratelimit(memcg
,
1038 MEM_CGROUP_TARGET_THRESH
))) {
1040 bool do_numainfo __maybe_unused
;
1042 do_softlimit
= mem_cgroup_event_ratelimit(memcg
,
1043 MEM_CGROUP_TARGET_SOFTLIMIT
);
1044 #if MAX_NUMNODES > 1
1045 do_numainfo
= mem_cgroup_event_ratelimit(memcg
,
1046 MEM_CGROUP_TARGET_NUMAINFO
);
1050 mem_cgroup_threshold(memcg
);
1051 if (unlikely(do_softlimit
))
1052 mem_cgroup_update_tree(memcg
, page
);
1053 #if MAX_NUMNODES > 1
1054 if (unlikely(do_numainfo
))
1055 atomic_inc(&memcg
->numainfo_events
);
1061 struct mem_cgroup
*mem_cgroup_from_cont(struct cgroup
*cont
)
1063 return mem_cgroup_from_css(
1064 cgroup_subsys_state(cont
, mem_cgroup_subsys_id
));
1067 struct mem_cgroup
*mem_cgroup_from_task(struct task_struct
*p
)
1070 * mm_update_next_owner() may clear mm->owner to NULL
1071 * if it races with swapoff, page migration, etc.
1072 * So this can be called with p == NULL.
1077 return mem_cgroup_from_css(task_subsys_state(p
, mem_cgroup_subsys_id
));
1080 struct mem_cgroup
*try_get_mem_cgroup_from_mm(struct mm_struct
*mm
)
1082 struct mem_cgroup
*memcg
= NULL
;
1087 * Because we have no locks, mm->owner's may be being moved to other
1088 * cgroup. We use css_tryget() here even if this looks
1089 * pessimistic (rather than adding locks here).
1093 memcg
= mem_cgroup_from_task(rcu_dereference(mm
->owner
));
1094 if (unlikely(!memcg
))
1096 } while (!css_tryget(&memcg
->css
));
1102 * Returns a next (in a pre-order walk) alive memcg (with elevated css
1103 * ref. count) or NULL if the whole root's subtree has been visited.
1105 * helper function to be used by mem_cgroup_iter
1107 static struct mem_cgroup
*__mem_cgroup_iter_next(struct mem_cgroup
*root
,
1108 struct mem_cgroup
*last_visited
)
1110 struct cgroup
*prev_cgroup
, *next_cgroup
;
1113 * Root is not visited by cgroup iterators so it needs an
1119 prev_cgroup
= (last_visited
== root
) ? NULL
1120 : last_visited
->css
.cgroup
;
1122 next_cgroup
= cgroup_next_descendant_pre(
1123 prev_cgroup
, root
->css
.cgroup
);
1126 * Even if we found a group we have to make sure it is
1127 * alive. css && !memcg means that the groups should be
1128 * skipped and we should continue the tree walk.
1129 * last_visited css is safe to use because it is
1130 * protected by css_get and the tree walk is rcu safe.
1133 struct mem_cgroup
*mem
= mem_cgroup_from_cont(
1135 if (css_tryget(&mem
->css
))
1138 prev_cgroup
= next_cgroup
;
1146 static void mem_cgroup_iter_invalidate(struct mem_cgroup
*root
)
1149 * When a group in the hierarchy below root is destroyed, the
1150 * hierarchy iterator can no longer be trusted since it might
1151 * have pointed to the destroyed group. Invalidate it.
1153 atomic_inc(&root
->dead_count
);
1156 static struct mem_cgroup
*
1157 mem_cgroup_iter_load(struct mem_cgroup_reclaim_iter
*iter
,
1158 struct mem_cgroup
*root
,
1161 struct mem_cgroup
*position
= NULL
;
1163 * A cgroup destruction happens in two stages: offlining and
1164 * release. They are separated by a RCU grace period.
1166 * If the iterator is valid, we may still race with an
1167 * offlining. The RCU lock ensures the object won't be
1168 * released, tryget will fail if we lost the race.
1170 *sequence
= atomic_read(&root
->dead_count
);
1171 if (iter
->last_dead_count
== *sequence
) {
1173 position
= iter
->last_visited
;
1174 if (position
&& !css_tryget(&position
->css
))
1180 static void mem_cgroup_iter_update(struct mem_cgroup_reclaim_iter
*iter
,
1181 struct mem_cgroup
*last_visited
,
1182 struct mem_cgroup
*new_position
,
1186 css_put(&last_visited
->css
);
1188 * We store the sequence count from the time @last_visited was
1189 * loaded successfully instead of rereading it here so that we
1190 * don't lose destruction events in between. We could have
1191 * raced with the destruction of @new_position after all.
1193 iter
->last_visited
= new_position
;
1195 iter
->last_dead_count
= sequence
;
1199 * mem_cgroup_iter - iterate over memory cgroup hierarchy
1200 * @root: hierarchy root
1201 * @prev: previously returned memcg, NULL on first invocation
1202 * @reclaim: cookie for shared reclaim walks, NULL for full walks
1204 * Returns references to children of the hierarchy below @root, or
1205 * @root itself, or %NULL after a full round-trip.
1207 * Caller must pass the return value in @prev on subsequent
1208 * invocations for reference counting, or use mem_cgroup_iter_break()
1209 * to cancel a hierarchy walk before the round-trip is complete.
1211 * Reclaimers can specify a zone and a priority level in @reclaim to
1212 * divide up the memcgs in the hierarchy among all concurrent
1213 * reclaimers operating on the same zone and priority.
1215 struct mem_cgroup
*mem_cgroup_iter(struct mem_cgroup
*root
,
1216 struct mem_cgroup
*prev
,
1217 struct mem_cgroup_reclaim_cookie
*reclaim
)
1219 struct mem_cgroup
*memcg
= NULL
;
1220 struct mem_cgroup
*last_visited
= NULL
;
1222 if (mem_cgroup_disabled())
1226 root
= root_mem_cgroup
;
1228 if (prev
&& !reclaim
)
1229 last_visited
= prev
;
1231 if (!root
->use_hierarchy
&& root
!= root_mem_cgroup
) {
1239 struct mem_cgroup_reclaim_iter
*uninitialized_var(iter
);
1240 int uninitialized_var(seq
);
1243 int nid
= zone_to_nid(reclaim
->zone
);
1244 int zid
= zone_idx(reclaim
->zone
);
1245 struct mem_cgroup_per_zone
*mz
;
1247 mz
= mem_cgroup_zoneinfo(root
, nid
, zid
);
1248 iter
= &mz
->reclaim_iter
[reclaim
->priority
];
1249 if (prev
&& reclaim
->generation
!= iter
->generation
) {
1250 iter
->last_visited
= NULL
;
1254 last_visited
= mem_cgroup_iter_load(iter
, root
, &seq
);
1257 memcg
= __mem_cgroup_iter_next(root
, last_visited
);
1260 mem_cgroup_iter_update(iter
, last_visited
, memcg
, seq
);
1264 else if (!prev
&& memcg
)
1265 reclaim
->generation
= iter
->generation
;
1274 if (prev
&& prev
!= root
)
1275 css_put(&prev
->css
);
1281 * mem_cgroup_iter_break - abort a hierarchy walk prematurely
1282 * @root: hierarchy root
1283 * @prev: last visited hierarchy member as returned by mem_cgroup_iter()
1285 void mem_cgroup_iter_break(struct mem_cgroup
*root
,
1286 struct mem_cgroup
*prev
)
1289 root
= root_mem_cgroup
;
1290 if (prev
&& prev
!= root
)
1291 css_put(&prev
->css
);
1295 * Iteration constructs for visiting all cgroups (under a tree). If
1296 * loops are exited prematurely (break), mem_cgroup_iter_break() must
1297 * be used for reference counting.
1299 #define for_each_mem_cgroup_tree(iter, root) \
1300 for (iter = mem_cgroup_iter(root, NULL, NULL); \
1302 iter = mem_cgroup_iter(root, iter, NULL))
1304 #define for_each_mem_cgroup(iter) \
1305 for (iter = mem_cgroup_iter(NULL, NULL, NULL); \
1307 iter = mem_cgroup_iter(NULL, iter, NULL))
1309 void __mem_cgroup_count_vm_event(struct mm_struct
*mm
, enum vm_event_item idx
)
1311 struct mem_cgroup
*memcg
;
1314 memcg
= mem_cgroup_from_task(rcu_dereference(mm
->owner
));
1315 if (unlikely(!memcg
))
1320 this_cpu_inc(memcg
->stat
->events
[MEM_CGROUP_EVENTS_PGFAULT
]);
1323 this_cpu_inc(memcg
->stat
->events
[MEM_CGROUP_EVENTS_PGMAJFAULT
]);
1331 EXPORT_SYMBOL(__mem_cgroup_count_vm_event
);
1334 * mem_cgroup_zone_lruvec - get the lru list vector for a zone and memcg
1335 * @zone: zone of the wanted lruvec
1336 * @memcg: memcg of the wanted lruvec
1338 * Returns the lru list vector holding pages for the given @zone and
1339 * @mem. This can be the global zone lruvec, if the memory controller
1342 struct lruvec
*mem_cgroup_zone_lruvec(struct zone
*zone
,
1343 struct mem_cgroup
*memcg
)
1345 struct mem_cgroup_per_zone
*mz
;
1346 struct lruvec
*lruvec
;
1348 if (mem_cgroup_disabled()) {
1349 lruvec
= &zone
->lruvec
;
1353 mz
= mem_cgroup_zoneinfo(memcg
, zone_to_nid(zone
), zone_idx(zone
));
1354 lruvec
= &mz
->lruvec
;
1357 * Since a node can be onlined after the mem_cgroup was created,
1358 * we have to be prepared to initialize lruvec->zone here;
1359 * and if offlined then reonlined, we need to reinitialize it.
1361 if (unlikely(lruvec
->zone
!= zone
))
1362 lruvec
->zone
= zone
;
1367 * Following LRU functions are allowed to be used without PCG_LOCK.
1368 * Operations are called by routine of global LRU independently from memcg.
1369 * What we have to take care of here is validness of pc->mem_cgroup.
1371 * Changes to pc->mem_cgroup happens when
1374 * In typical case, "charge" is done before add-to-lru. Exception is SwapCache.
1375 * It is added to LRU before charge.
1376 * If PCG_USED bit is not set, page_cgroup is not added to this private LRU.
1377 * When moving account, the page is not on LRU. It's isolated.
1381 * mem_cgroup_page_lruvec - return lruvec for adding an lru page
1383 * @zone: zone of the page
1385 struct lruvec
*mem_cgroup_page_lruvec(struct page
*page
, struct zone
*zone
)
1387 struct mem_cgroup_per_zone
*mz
;
1388 struct mem_cgroup
*memcg
;
1389 struct page_cgroup
*pc
;
1390 struct lruvec
*lruvec
;
1392 if (mem_cgroup_disabled()) {
1393 lruvec
= &zone
->lruvec
;
1397 pc
= lookup_page_cgroup(page
);
1398 memcg
= pc
->mem_cgroup
;
1401 * Surreptitiously switch any uncharged offlist page to root:
1402 * an uncharged page off lru does nothing to secure
1403 * its former mem_cgroup from sudden removal.
1405 * Our caller holds lru_lock, and PageCgroupUsed is updated
1406 * under page_cgroup lock: between them, they make all uses
1407 * of pc->mem_cgroup safe.
1409 if (!PageLRU(page
) && !PageCgroupUsed(pc
) && memcg
!= root_mem_cgroup
)
1410 pc
->mem_cgroup
= memcg
= root_mem_cgroup
;
1412 mz
= page_cgroup_zoneinfo(memcg
, page
);
1413 lruvec
= &mz
->lruvec
;
1416 * Since a node can be onlined after the mem_cgroup was created,
1417 * we have to be prepared to initialize lruvec->zone here;
1418 * and if offlined then reonlined, we need to reinitialize it.
1420 if (unlikely(lruvec
->zone
!= zone
))
1421 lruvec
->zone
= zone
;
1426 * mem_cgroup_update_lru_size - account for adding or removing an lru page
1427 * @lruvec: mem_cgroup per zone lru vector
1428 * @lru: index of lru list the page is sitting on
1429 * @nr_pages: positive when adding or negative when removing
1431 * This function must be called when a page is added to or removed from an
1434 void mem_cgroup_update_lru_size(struct lruvec
*lruvec
, enum lru_list lru
,
1437 struct mem_cgroup_per_zone
*mz
;
1438 unsigned long *lru_size
;
1440 if (mem_cgroup_disabled())
1443 mz
= container_of(lruvec
, struct mem_cgroup_per_zone
, lruvec
);
1444 lru_size
= mz
->lru_size
+ lru
;
1445 *lru_size
+= nr_pages
;
1446 VM_BUG_ON((long)(*lru_size
) < 0);
1450 * Checks whether given mem is same or in the root_mem_cgroup's
1453 bool __mem_cgroup_same_or_subtree(const struct mem_cgroup
*root_memcg
,
1454 struct mem_cgroup
*memcg
)
1456 if (root_memcg
== memcg
)
1458 if (!root_memcg
->use_hierarchy
|| !memcg
)
1460 return css_is_ancestor(&memcg
->css
, &root_memcg
->css
);
1463 static bool mem_cgroup_same_or_subtree(const struct mem_cgroup
*root_memcg
,
1464 struct mem_cgroup
*memcg
)
1469 ret
= __mem_cgroup_same_or_subtree(root_memcg
, memcg
);
1474 bool task_in_mem_cgroup(struct task_struct
*task
,
1475 const struct mem_cgroup
*memcg
)
1477 struct mem_cgroup
*curr
= NULL
;
1478 struct task_struct
*p
;
1481 p
= find_lock_task_mm(task
);
1483 curr
= try_get_mem_cgroup_from_mm(p
->mm
);
1487 * All threads may have already detached their mm's, but the oom
1488 * killer still needs to detect if they have already been oom
1489 * killed to prevent needlessly killing additional tasks.
1492 curr
= mem_cgroup_from_task(task
);
1494 css_get(&curr
->css
);
1500 * We should check use_hierarchy of "memcg" not "curr". Because checking
1501 * use_hierarchy of "curr" here make this function true if hierarchy is
1502 * enabled in "curr" and "curr" is a child of "memcg" in *cgroup*
1503 * hierarchy(even if use_hierarchy is disabled in "memcg").
1505 ret
= mem_cgroup_same_or_subtree(memcg
, curr
);
1506 css_put(&curr
->css
);
1510 int mem_cgroup_inactive_anon_is_low(struct lruvec
*lruvec
)
1512 unsigned long inactive_ratio
;
1513 unsigned long inactive
;
1514 unsigned long active
;
1517 inactive
= mem_cgroup_get_lru_size(lruvec
, LRU_INACTIVE_ANON
);
1518 active
= mem_cgroup_get_lru_size(lruvec
, LRU_ACTIVE_ANON
);
1520 gb
= (inactive
+ active
) >> (30 - PAGE_SHIFT
);
1522 inactive_ratio
= int_sqrt(10 * gb
);
1526 return inactive
* inactive_ratio
< active
;
1529 #define mem_cgroup_from_res_counter(counter, member) \
1530 container_of(counter, struct mem_cgroup, member)
1533 * mem_cgroup_margin - calculate chargeable space of a memory cgroup
1534 * @memcg: the memory cgroup
1536 * Returns the maximum amount of memory @mem can be charged with, in
1539 static unsigned long mem_cgroup_margin(struct mem_cgroup
*memcg
)
1541 unsigned long long margin
;
1543 margin
= res_counter_margin(&memcg
->res
);
1544 if (do_swap_account
)
1545 margin
= min(margin
, res_counter_margin(&memcg
->memsw
));
1546 return margin
>> PAGE_SHIFT
;
1549 int mem_cgroup_swappiness(struct mem_cgroup
*memcg
)
1551 struct cgroup
*cgrp
= memcg
->css
.cgroup
;
1554 if (cgrp
->parent
== NULL
)
1555 return vm_swappiness
;
1557 return memcg
->swappiness
;
1561 * memcg->moving_account is used for checking possibility that some thread is
1562 * calling move_account(). When a thread on CPU-A starts moving pages under
1563 * a memcg, other threads should check memcg->moving_account under
1564 * rcu_read_lock(), like this:
1568 * memcg->moving_account+1 if (memcg->mocing_account)
1570 * synchronize_rcu() update something.
1575 /* for quick checking without looking up memcg */
1576 atomic_t memcg_moving __read_mostly
;
1578 static void mem_cgroup_start_move(struct mem_cgroup
*memcg
)
1580 atomic_inc(&memcg_moving
);
1581 atomic_inc(&memcg
->moving_account
);
1585 static void mem_cgroup_end_move(struct mem_cgroup
*memcg
)
1588 * Now, mem_cgroup_clear_mc() may call this function with NULL.
1589 * We check NULL in callee rather than caller.
1592 atomic_dec(&memcg_moving
);
1593 atomic_dec(&memcg
->moving_account
);
1598 * 2 routines for checking "mem" is under move_account() or not.
1600 * mem_cgroup_stolen() - checking whether a cgroup is mc.from or not. This
1601 * is used for avoiding races in accounting. If true,
1602 * pc->mem_cgroup may be overwritten.
1604 * mem_cgroup_under_move() - checking a cgroup is mc.from or mc.to or
1605 * under hierarchy of moving cgroups. This is for
1606 * waiting at hith-memory prressure caused by "move".
1609 static bool mem_cgroup_stolen(struct mem_cgroup
*memcg
)
1611 VM_BUG_ON(!rcu_read_lock_held());
1612 return atomic_read(&memcg
->moving_account
) > 0;
1615 static bool mem_cgroup_under_move(struct mem_cgroup
*memcg
)
1617 struct mem_cgroup
*from
;
1618 struct mem_cgroup
*to
;
1621 * Unlike task_move routines, we access mc.to, mc.from not under
1622 * mutual exclusion by cgroup_mutex. Here, we take spinlock instead.
1624 spin_lock(&mc
.lock
);
1630 ret
= mem_cgroup_same_or_subtree(memcg
, from
)
1631 || mem_cgroup_same_or_subtree(memcg
, to
);
1633 spin_unlock(&mc
.lock
);
1637 static bool mem_cgroup_wait_acct_move(struct mem_cgroup
*memcg
)
1639 if (mc
.moving_task
&& current
!= mc
.moving_task
) {
1640 if (mem_cgroup_under_move(memcg
)) {
1642 prepare_to_wait(&mc
.waitq
, &wait
, TASK_INTERRUPTIBLE
);
1643 /* moving charge context might have finished. */
1646 finish_wait(&mc
.waitq
, &wait
);
1654 * Take this lock when
1655 * - a code tries to modify page's memcg while it's USED.
1656 * - a code tries to modify page state accounting in a memcg.
1657 * see mem_cgroup_stolen(), too.
1659 static void move_lock_mem_cgroup(struct mem_cgroup
*memcg
,
1660 unsigned long *flags
)
1662 spin_lock_irqsave(&memcg
->move_lock
, *flags
);
1665 static void move_unlock_mem_cgroup(struct mem_cgroup
*memcg
,
1666 unsigned long *flags
)
1668 spin_unlock_irqrestore(&memcg
->move_lock
, *flags
);
1671 #define K(x) ((x) << (PAGE_SHIFT-10))
1673 * mem_cgroup_print_oom_info: Print OOM information relevant to memory controller.
1674 * @memcg: The memory cgroup that went over limit
1675 * @p: Task that is going to be killed
1677 * NOTE: @memcg and @p's mem_cgroup can be different when hierarchy is
1680 void mem_cgroup_print_oom_info(struct mem_cgroup
*memcg
, struct task_struct
*p
)
1682 struct cgroup
*task_cgrp
;
1683 struct cgroup
*mem_cgrp
;
1685 * Need a buffer in BSS, can't rely on allocations. The code relies
1686 * on the assumption that OOM is serialized for memory controller.
1687 * If this assumption is broken, revisit this code.
1689 static char memcg_name
[PATH_MAX
];
1691 struct mem_cgroup
*iter
;
1699 mem_cgrp
= memcg
->css
.cgroup
;
1700 task_cgrp
= task_cgroup(p
, mem_cgroup_subsys_id
);
1702 ret
= cgroup_path(task_cgrp
, memcg_name
, PATH_MAX
);
1705 * Unfortunately, we are unable to convert to a useful name
1706 * But we'll still print out the usage information
1713 pr_info("Task in %s killed", memcg_name
);
1716 ret
= cgroup_path(mem_cgrp
, memcg_name
, PATH_MAX
);
1724 * Continues from above, so we don't need an KERN_ level
1726 pr_cont(" as a result of limit of %s\n", memcg_name
);
1729 pr_info("memory: usage %llukB, limit %llukB, failcnt %llu\n",
1730 res_counter_read_u64(&memcg
->res
, RES_USAGE
) >> 10,
1731 res_counter_read_u64(&memcg
->res
, RES_LIMIT
) >> 10,
1732 res_counter_read_u64(&memcg
->res
, RES_FAILCNT
));
1733 pr_info("memory+swap: usage %llukB, limit %llukB, failcnt %llu\n",
1734 res_counter_read_u64(&memcg
->memsw
, RES_USAGE
) >> 10,
1735 res_counter_read_u64(&memcg
->memsw
, RES_LIMIT
) >> 10,
1736 res_counter_read_u64(&memcg
->memsw
, RES_FAILCNT
));
1737 pr_info("kmem: usage %llukB, limit %llukB, failcnt %llu\n",
1738 res_counter_read_u64(&memcg
->kmem
, RES_USAGE
) >> 10,
1739 res_counter_read_u64(&memcg
->kmem
, RES_LIMIT
) >> 10,
1740 res_counter_read_u64(&memcg
->kmem
, RES_FAILCNT
));
1742 for_each_mem_cgroup_tree(iter
, memcg
) {
1743 pr_info("Memory cgroup stats");
1746 ret
= cgroup_path(iter
->css
.cgroup
, memcg_name
, PATH_MAX
);
1748 pr_cont(" for %s", memcg_name
);
1752 for (i
= 0; i
< MEM_CGROUP_STAT_NSTATS
; i
++) {
1753 if (i
== MEM_CGROUP_STAT_SWAP
&& !do_swap_account
)
1755 pr_cont(" %s:%ldKB", mem_cgroup_stat_names
[i
],
1756 K(mem_cgroup_read_stat(iter
, i
)));
1759 for (i
= 0; i
< NR_LRU_LISTS
; i
++)
1760 pr_cont(" %s:%luKB", mem_cgroup_lru_names
[i
],
1761 K(mem_cgroup_nr_lru_pages(iter
, BIT(i
))));
1768 * This function returns the number of memcg under hierarchy tree. Returns
1769 * 1(self count) if no children.
1771 static int mem_cgroup_count_children(struct mem_cgroup
*memcg
)
1774 struct mem_cgroup
*iter
;
1776 for_each_mem_cgroup_tree(iter
, memcg
)
1782 * Return the memory (and swap, if configured) limit for a memcg.
1784 static u64
mem_cgroup_get_limit(struct mem_cgroup
*memcg
)
1788 limit
= res_counter_read_u64(&memcg
->res
, RES_LIMIT
);
1791 * Do not consider swap space if we cannot swap due to swappiness
1793 if (mem_cgroup_swappiness(memcg
)) {
1796 limit
+= total_swap_pages
<< PAGE_SHIFT
;
1797 memsw
= res_counter_read_u64(&memcg
->memsw
, RES_LIMIT
);
1800 * If memsw is finite and limits the amount of swap space
1801 * available to this memcg, return that limit.
1803 limit
= min(limit
, memsw
);
1809 static void mem_cgroup_out_of_memory(struct mem_cgroup
*memcg
, gfp_t gfp_mask
,
1812 struct mem_cgroup
*iter
;
1813 unsigned long chosen_points
= 0;
1814 unsigned long totalpages
;
1815 unsigned int points
= 0;
1816 struct task_struct
*chosen
= NULL
;
1819 * If current has a pending SIGKILL or is exiting, then automatically
1820 * select it. The goal is to allow it to allocate so that it may
1821 * quickly exit and free its memory.
1823 if (fatal_signal_pending(current
) || current
->flags
& PF_EXITING
) {
1824 set_thread_flag(TIF_MEMDIE
);
1828 check_panic_on_oom(CONSTRAINT_MEMCG
, gfp_mask
, order
, NULL
);
1829 totalpages
= mem_cgroup_get_limit(memcg
) >> PAGE_SHIFT
? : 1;
1830 for_each_mem_cgroup_tree(iter
, memcg
) {
1831 struct cgroup
*cgroup
= iter
->css
.cgroup
;
1832 struct cgroup_iter it
;
1833 struct task_struct
*task
;
1835 cgroup_iter_start(cgroup
, &it
);
1836 while ((task
= cgroup_iter_next(cgroup
, &it
))) {
1837 switch (oom_scan_process_thread(task
, totalpages
, NULL
,
1839 case OOM_SCAN_SELECT
:
1841 put_task_struct(chosen
);
1843 chosen_points
= ULONG_MAX
;
1844 get_task_struct(chosen
);
1846 case OOM_SCAN_CONTINUE
:
1848 case OOM_SCAN_ABORT
:
1849 cgroup_iter_end(cgroup
, &it
);
1850 mem_cgroup_iter_break(memcg
, iter
);
1852 put_task_struct(chosen
);
1857 points
= oom_badness(task
, memcg
, NULL
, totalpages
);
1858 if (points
> chosen_points
) {
1860 put_task_struct(chosen
);
1862 chosen_points
= points
;
1863 get_task_struct(chosen
);
1866 cgroup_iter_end(cgroup
, &it
);
1871 points
= chosen_points
* 1000 / totalpages
;
1872 oom_kill_process(chosen
, gfp_mask
, order
, points
, totalpages
, memcg
,
1873 NULL
, "Memory cgroup out of memory");
1876 static unsigned long mem_cgroup_reclaim(struct mem_cgroup
*memcg
,
1878 unsigned long flags
)
1880 unsigned long total
= 0;
1881 bool noswap
= false;
1884 if (flags
& MEM_CGROUP_RECLAIM_NOSWAP
)
1886 if (!(flags
& MEM_CGROUP_RECLAIM_SHRINK
) && memcg
->memsw_is_minimum
)
1889 for (loop
= 0; loop
< MEM_CGROUP_MAX_RECLAIM_LOOPS
; loop
++) {
1891 drain_all_stock_async(memcg
);
1892 total
+= try_to_free_mem_cgroup_pages(memcg
, gfp_mask
, noswap
);
1894 * Allow limit shrinkers, which are triggered directly
1895 * by userspace, to catch signals and stop reclaim
1896 * after minimal progress, regardless of the margin.
1898 if (total
&& (flags
& MEM_CGROUP_RECLAIM_SHRINK
))
1900 if (mem_cgroup_margin(memcg
))
1903 * If nothing was reclaimed after two attempts, there
1904 * may be no reclaimable pages in this hierarchy.
1913 * test_mem_cgroup_node_reclaimable
1914 * @memcg: the target memcg
1915 * @nid: the node ID to be checked.
1916 * @noswap : specify true here if the user wants flle only information.
1918 * This function returns whether the specified memcg contains any
1919 * reclaimable pages on a node. Returns true if there are any reclaimable
1920 * pages in the node.
1922 static bool test_mem_cgroup_node_reclaimable(struct mem_cgroup
*memcg
,
1923 int nid
, bool noswap
)
1925 if (mem_cgroup_node_nr_lru_pages(memcg
, nid
, LRU_ALL_FILE
))
1927 if (noswap
|| !total_swap_pages
)
1929 if (mem_cgroup_node_nr_lru_pages(memcg
, nid
, LRU_ALL_ANON
))
1934 #if MAX_NUMNODES > 1
1937 * Always updating the nodemask is not very good - even if we have an empty
1938 * list or the wrong list here, we can start from some node and traverse all
1939 * nodes based on the zonelist. So update the list loosely once per 10 secs.
1942 static void mem_cgroup_may_update_nodemask(struct mem_cgroup
*memcg
)
1946 * numainfo_events > 0 means there was at least NUMAINFO_EVENTS_TARGET
1947 * pagein/pageout changes since the last update.
1949 if (!atomic_read(&memcg
->numainfo_events
))
1951 if (atomic_inc_return(&memcg
->numainfo_updating
) > 1)
1954 /* make a nodemask where this memcg uses memory from */
1955 memcg
->scan_nodes
= node_states
[N_MEMORY
];
1957 for_each_node_mask(nid
, node_states
[N_MEMORY
]) {
1959 if (!test_mem_cgroup_node_reclaimable(memcg
, nid
, false))
1960 node_clear(nid
, memcg
->scan_nodes
);
1963 atomic_set(&memcg
->numainfo_events
, 0);
1964 atomic_set(&memcg
->numainfo_updating
, 0);
1968 * Selecting a node where we start reclaim from. Because what we need is just
1969 * reducing usage counter, start from anywhere is O,K. Considering
1970 * memory reclaim from current node, there are pros. and cons.
1972 * Freeing memory from current node means freeing memory from a node which
1973 * we'll use or we've used. So, it may make LRU bad. And if several threads
1974 * hit limits, it will see a contention on a node. But freeing from remote
1975 * node means more costs for memory reclaim because of memory latency.
1977 * Now, we use round-robin. Better algorithm is welcomed.
1979 int mem_cgroup_select_victim_node(struct mem_cgroup
*memcg
)
1983 mem_cgroup_may_update_nodemask(memcg
);
1984 node
= memcg
->last_scanned_node
;
1986 node
= next_node(node
, memcg
->scan_nodes
);
1987 if (node
== MAX_NUMNODES
)
1988 node
= first_node(memcg
->scan_nodes
);
1990 * We call this when we hit limit, not when pages are added to LRU.
1991 * No LRU may hold pages because all pages are UNEVICTABLE or
1992 * memcg is too small and all pages are not on LRU. In that case,
1993 * we use curret node.
1995 if (unlikely(node
== MAX_NUMNODES
))
1996 node
= numa_node_id();
1998 memcg
->last_scanned_node
= node
;
2003 * Check all nodes whether it contains reclaimable pages or not.
2004 * For quick scan, we make use of scan_nodes. This will allow us to skip
2005 * unused nodes. But scan_nodes is lazily updated and may not cotain
2006 * enough new information. We need to do double check.
2008 static bool mem_cgroup_reclaimable(struct mem_cgroup
*memcg
, bool noswap
)
2013 * quick check...making use of scan_node.
2014 * We can skip unused nodes.
2016 if (!nodes_empty(memcg
->scan_nodes
)) {
2017 for (nid
= first_node(memcg
->scan_nodes
);
2019 nid
= next_node(nid
, memcg
->scan_nodes
)) {
2021 if (test_mem_cgroup_node_reclaimable(memcg
, nid
, noswap
))
2026 * Check rest of nodes.
2028 for_each_node_state(nid
, N_MEMORY
) {
2029 if (node_isset(nid
, memcg
->scan_nodes
))
2031 if (test_mem_cgroup_node_reclaimable(memcg
, nid
, noswap
))
2038 int mem_cgroup_select_victim_node(struct mem_cgroup
*memcg
)
2043 static bool mem_cgroup_reclaimable(struct mem_cgroup
*memcg
, bool noswap
)
2045 return test_mem_cgroup_node_reclaimable(memcg
, 0, noswap
);
2049 static int mem_cgroup_soft_reclaim(struct mem_cgroup
*root_memcg
,
2052 unsigned long *total_scanned
)
2054 struct mem_cgroup
*victim
= NULL
;
2057 unsigned long excess
;
2058 unsigned long nr_scanned
;
2059 struct mem_cgroup_reclaim_cookie reclaim
= {
2064 excess
= res_counter_soft_limit_excess(&root_memcg
->res
) >> PAGE_SHIFT
;
2067 victim
= mem_cgroup_iter(root_memcg
, victim
, &reclaim
);
2072 * If we have not been able to reclaim
2073 * anything, it might because there are
2074 * no reclaimable pages under this hierarchy
2079 * We want to do more targeted reclaim.
2080 * excess >> 2 is not to excessive so as to
2081 * reclaim too much, nor too less that we keep
2082 * coming back to reclaim from this cgroup
2084 if (total
>= (excess
>> 2) ||
2085 (loop
> MEM_CGROUP_MAX_RECLAIM_LOOPS
))
2090 if (!mem_cgroup_reclaimable(victim
, false))
2092 total
+= mem_cgroup_shrink_node_zone(victim
, gfp_mask
, false,
2094 *total_scanned
+= nr_scanned
;
2095 if (!res_counter_soft_limit_excess(&root_memcg
->res
))
2098 mem_cgroup_iter_break(root_memcg
, victim
);
2103 * Check OOM-Killer is already running under our hierarchy.
2104 * If someone is running, return false.
2105 * Has to be called with memcg_oom_lock
2107 static bool mem_cgroup_oom_lock(struct mem_cgroup
*memcg
)
2109 struct mem_cgroup
*iter
, *failed
= NULL
;
2111 for_each_mem_cgroup_tree(iter
, memcg
) {
2112 if (iter
->oom_lock
) {
2114 * this subtree of our hierarchy is already locked
2115 * so we cannot give a lock.
2118 mem_cgroup_iter_break(memcg
, iter
);
2121 iter
->oom_lock
= true;
2128 * OK, we failed to lock the whole subtree so we have to clean up
2129 * what we set up to the failing subtree
2131 for_each_mem_cgroup_tree(iter
, memcg
) {
2132 if (iter
== failed
) {
2133 mem_cgroup_iter_break(memcg
, iter
);
2136 iter
->oom_lock
= false;
2142 * Has to be called with memcg_oom_lock
2144 static int mem_cgroup_oom_unlock(struct mem_cgroup
*memcg
)
2146 struct mem_cgroup
*iter
;
2148 for_each_mem_cgroup_tree(iter
, memcg
)
2149 iter
->oom_lock
= false;
2153 static void mem_cgroup_mark_under_oom(struct mem_cgroup
*memcg
)
2155 struct mem_cgroup
*iter
;
2157 for_each_mem_cgroup_tree(iter
, memcg
)
2158 atomic_inc(&iter
->under_oom
);
2161 static void mem_cgroup_unmark_under_oom(struct mem_cgroup
*memcg
)
2163 struct mem_cgroup
*iter
;
2166 * When a new child is created while the hierarchy is under oom,
2167 * mem_cgroup_oom_lock() may not be called. We have to use
2168 * atomic_add_unless() here.
2170 for_each_mem_cgroup_tree(iter
, memcg
)
2171 atomic_add_unless(&iter
->under_oom
, -1, 0);
2174 static DEFINE_SPINLOCK(memcg_oom_lock
);
2175 static DECLARE_WAIT_QUEUE_HEAD(memcg_oom_waitq
);
2177 struct oom_wait_info
{
2178 struct mem_cgroup
*memcg
;
2182 static int memcg_oom_wake_function(wait_queue_t
*wait
,
2183 unsigned mode
, int sync
, void *arg
)
2185 struct mem_cgroup
*wake_memcg
= (struct mem_cgroup
*)arg
;
2186 struct mem_cgroup
*oom_wait_memcg
;
2187 struct oom_wait_info
*oom_wait_info
;
2189 oom_wait_info
= container_of(wait
, struct oom_wait_info
, wait
);
2190 oom_wait_memcg
= oom_wait_info
->memcg
;
2193 * Both of oom_wait_info->memcg and wake_memcg are stable under us.
2194 * Then we can use css_is_ancestor without taking care of RCU.
2196 if (!mem_cgroup_same_or_subtree(oom_wait_memcg
, wake_memcg
)
2197 && !mem_cgroup_same_or_subtree(wake_memcg
, oom_wait_memcg
))
2199 return autoremove_wake_function(wait
, mode
, sync
, arg
);
2202 static void memcg_wakeup_oom(struct mem_cgroup
*memcg
)
2204 /* for filtering, pass "memcg" as argument. */
2205 __wake_up(&memcg_oom_waitq
, TASK_NORMAL
, 0, memcg
);
2208 static void memcg_oom_recover(struct mem_cgroup
*memcg
)
2210 if (memcg
&& atomic_read(&memcg
->under_oom
))
2211 memcg_wakeup_oom(memcg
);
2215 * try to call OOM killer. returns false if we should exit memory-reclaim loop.
2217 static bool mem_cgroup_handle_oom(struct mem_cgroup
*memcg
, gfp_t mask
,
2220 struct oom_wait_info owait
;
2221 bool locked
, need_to_kill
;
2223 owait
.memcg
= memcg
;
2224 owait
.wait
.flags
= 0;
2225 owait
.wait
.func
= memcg_oom_wake_function
;
2226 owait
.wait
.private = current
;
2227 INIT_LIST_HEAD(&owait
.wait
.task_list
);
2228 need_to_kill
= true;
2229 mem_cgroup_mark_under_oom(memcg
);
2231 /* At first, try to OOM lock hierarchy under memcg.*/
2232 spin_lock(&memcg_oom_lock
);
2233 locked
= mem_cgroup_oom_lock(memcg
);
2235 * Even if signal_pending(), we can't quit charge() loop without
2236 * accounting. So, UNINTERRUPTIBLE is appropriate. But SIGKILL
2237 * under OOM is always welcomed, use TASK_KILLABLE here.
2239 prepare_to_wait(&memcg_oom_waitq
, &owait
.wait
, TASK_KILLABLE
);
2240 if (!locked
|| memcg
->oom_kill_disable
)
2241 need_to_kill
= false;
2243 mem_cgroup_oom_notify(memcg
);
2244 spin_unlock(&memcg_oom_lock
);
2247 finish_wait(&memcg_oom_waitq
, &owait
.wait
);
2248 mem_cgroup_out_of_memory(memcg
, mask
, order
);
2251 finish_wait(&memcg_oom_waitq
, &owait
.wait
);
2253 spin_lock(&memcg_oom_lock
);
2255 mem_cgroup_oom_unlock(memcg
);
2256 memcg_wakeup_oom(memcg
);
2257 spin_unlock(&memcg_oom_lock
);
2259 mem_cgroup_unmark_under_oom(memcg
);
2261 if (test_thread_flag(TIF_MEMDIE
) || fatal_signal_pending(current
))
2263 /* Give chance to dying process */
2264 schedule_timeout_uninterruptible(1);
2269 * Currently used to update mapped file statistics, but the routine can be
2270 * generalized to update other statistics as well.
2272 * Notes: Race condition
2274 * We usually use page_cgroup_lock() for accessing page_cgroup member but
2275 * it tends to be costly. But considering some conditions, we doesn't need
2276 * to do so _always_.
2278 * Considering "charge", lock_page_cgroup() is not required because all
2279 * file-stat operations happen after a page is attached to radix-tree. There
2280 * are no race with "charge".
2282 * Considering "uncharge", we know that memcg doesn't clear pc->mem_cgroup
2283 * at "uncharge" intentionally. So, we always see valid pc->mem_cgroup even
2284 * if there are race with "uncharge". Statistics itself is properly handled
2287 * Considering "move", this is an only case we see a race. To make the race
2288 * small, we check mm->moving_account and detect there are possibility of race
2289 * If there is, we take a lock.
2292 void __mem_cgroup_begin_update_page_stat(struct page
*page
,
2293 bool *locked
, unsigned long *flags
)
2295 struct mem_cgroup
*memcg
;
2296 struct page_cgroup
*pc
;
2298 pc
= lookup_page_cgroup(page
);
2300 memcg
= pc
->mem_cgroup
;
2301 if (unlikely(!memcg
|| !PageCgroupUsed(pc
)))
2304 * If this memory cgroup is not under account moving, we don't
2305 * need to take move_lock_mem_cgroup(). Because we already hold
2306 * rcu_read_lock(), any calls to move_account will be delayed until
2307 * rcu_read_unlock() if mem_cgroup_stolen() == true.
2309 if (!mem_cgroup_stolen(memcg
))
2312 move_lock_mem_cgroup(memcg
, flags
);
2313 if (memcg
!= pc
->mem_cgroup
|| !PageCgroupUsed(pc
)) {
2314 move_unlock_mem_cgroup(memcg
, flags
);
2320 void __mem_cgroup_end_update_page_stat(struct page
*page
, unsigned long *flags
)
2322 struct page_cgroup
*pc
= lookup_page_cgroup(page
);
2325 * It's guaranteed that pc->mem_cgroup never changes while
2326 * lock is held because a routine modifies pc->mem_cgroup
2327 * should take move_lock_mem_cgroup().
2329 move_unlock_mem_cgroup(pc
->mem_cgroup
, flags
);
2332 void mem_cgroup_update_page_stat(struct page
*page
,
2333 enum mem_cgroup_page_stat_item idx
, int val
)
2335 struct mem_cgroup
*memcg
;
2336 struct page_cgroup
*pc
= lookup_page_cgroup(page
);
2337 unsigned long uninitialized_var(flags
);
2339 if (mem_cgroup_disabled())
2342 memcg
= pc
->mem_cgroup
;
2343 if (unlikely(!memcg
|| !PageCgroupUsed(pc
)))
2347 case MEMCG_NR_FILE_MAPPED
:
2348 idx
= MEM_CGROUP_STAT_FILE_MAPPED
;
2354 this_cpu_add(memcg
->stat
->count
[idx
], val
);
2358 * size of first charge trial. "32" comes from vmscan.c's magic value.
2359 * TODO: maybe necessary to use big numbers in big irons.
2361 #define CHARGE_BATCH 32U
2362 struct memcg_stock_pcp
{
2363 struct mem_cgroup
*cached
; /* this never be root cgroup */
2364 unsigned int nr_pages
;
2365 struct work_struct work
;
2366 unsigned long flags
;
2367 #define FLUSHING_CACHED_CHARGE 0
2369 static DEFINE_PER_CPU(struct memcg_stock_pcp
, memcg_stock
);
2370 static DEFINE_MUTEX(percpu_charge_mutex
);
2373 * consume_stock: Try to consume stocked charge on this cpu.
2374 * @memcg: memcg to consume from.
2375 * @nr_pages: how many pages to charge.
2377 * The charges will only happen if @memcg matches the current cpu's memcg
2378 * stock, and at least @nr_pages are available in that stock. Failure to
2379 * service an allocation will refill the stock.
2381 * returns true if successful, false otherwise.
2383 static bool consume_stock(struct mem_cgroup
*memcg
, unsigned int nr_pages
)
2385 struct memcg_stock_pcp
*stock
;
2388 if (nr_pages
> CHARGE_BATCH
)
2391 stock
= &get_cpu_var(memcg_stock
);
2392 if (memcg
== stock
->cached
&& stock
->nr_pages
>= nr_pages
)
2393 stock
->nr_pages
-= nr_pages
;
2394 else /* need to call res_counter_charge */
2396 put_cpu_var(memcg_stock
);
2401 * Returns stocks cached in percpu to res_counter and reset cached information.
2403 static void drain_stock(struct memcg_stock_pcp
*stock
)
2405 struct mem_cgroup
*old
= stock
->cached
;
2407 if (stock
->nr_pages
) {
2408 unsigned long bytes
= stock
->nr_pages
* PAGE_SIZE
;
2410 res_counter_uncharge(&old
->res
, bytes
);
2411 if (do_swap_account
)
2412 res_counter_uncharge(&old
->memsw
, bytes
);
2413 stock
->nr_pages
= 0;
2415 stock
->cached
= NULL
;
2419 * This must be called under preempt disabled or must be called by
2420 * a thread which is pinned to local cpu.
2422 static void drain_local_stock(struct work_struct
*dummy
)
2424 struct memcg_stock_pcp
*stock
= &__get_cpu_var(memcg_stock
);
2426 clear_bit(FLUSHING_CACHED_CHARGE
, &stock
->flags
);
2429 static void __init
memcg_stock_init(void)
2433 for_each_possible_cpu(cpu
) {
2434 struct memcg_stock_pcp
*stock
=
2435 &per_cpu(memcg_stock
, cpu
);
2436 INIT_WORK(&stock
->work
, drain_local_stock
);
2441 * Cache charges(val) which is from res_counter, to local per_cpu area.
2442 * This will be consumed by consume_stock() function, later.
2444 static void refill_stock(struct mem_cgroup
*memcg
, unsigned int nr_pages
)
2446 struct memcg_stock_pcp
*stock
= &get_cpu_var(memcg_stock
);
2448 if (stock
->cached
!= memcg
) { /* reset if necessary */
2450 stock
->cached
= memcg
;
2452 stock
->nr_pages
+= nr_pages
;
2453 put_cpu_var(memcg_stock
);
2457 * Drains all per-CPU charge caches for given root_memcg resp. subtree
2458 * of the hierarchy under it. sync flag says whether we should block
2459 * until the work is done.
2461 static void drain_all_stock(struct mem_cgroup
*root_memcg
, bool sync
)
2465 /* Notify other cpus that system-wide "drain" is running */
2468 for_each_online_cpu(cpu
) {
2469 struct memcg_stock_pcp
*stock
= &per_cpu(memcg_stock
, cpu
);
2470 struct mem_cgroup
*memcg
;
2472 memcg
= stock
->cached
;
2473 if (!memcg
|| !stock
->nr_pages
)
2475 if (!mem_cgroup_same_or_subtree(root_memcg
, memcg
))
2477 if (!test_and_set_bit(FLUSHING_CACHED_CHARGE
, &stock
->flags
)) {
2479 drain_local_stock(&stock
->work
);
2481 schedule_work_on(cpu
, &stock
->work
);
2489 for_each_online_cpu(cpu
) {
2490 struct memcg_stock_pcp
*stock
= &per_cpu(memcg_stock
, cpu
);
2491 if (test_bit(FLUSHING_CACHED_CHARGE
, &stock
->flags
))
2492 flush_work(&stock
->work
);
2499 * Tries to drain stocked charges in other cpus. This function is asynchronous
2500 * and just put a work per cpu for draining localy on each cpu. Caller can
2501 * expects some charges will be back to res_counter later but cannot wait for
2504 static void drain_all_stock_async(struct mem_cgroup
*root_memcg
)
2507 * If someone calls draining, avoid adding more kworker runs.
2509 if (!mutex_trylock(&percpu_charge_mutex
))
2511 drain_all_stock(root_memcg
, false);
2512 mutex_unlock(&percpu_charge_mutex
);
2515 /* This is a synchronous drain interface. */
2516 static void drain_all_stock_sync(struct mem_cgroup
*root_memcg
)
2518 /* called when force_empty is called */
2519 mutex_lock(&percpu_charge_mutex
);
2520 drain_all_stock(root_memcg
, true);
2521 mutex_unlock(&percpu_charge_mutex
);
2525 * This function drains percpu counter value from DEAD cpu and
2526 * move it to local cpu. Note that this function can be preempted.
2528 static void mem_cgroup_drain_pcp_counter(struct mem_cgroup
*memcg
, int cpu
)
2532 spin_lock(&memcg
->pcp_counter_lock
);
2533 for (i
= 0; i
< MEM_CGROUP_STAT_NSTATS
; i
++) {
2534 long x
= per_cpu(memcg
->stat
->count
[i
], cpu
);
2536 per_cpu(memcg
->stat
->count
[i
], cpu
) = 0;
2537 memcg
->nocpu_base
.count
[i
] += x
;
2539 for (i
= 0; i
< MEM_CGROUP_EVENTS_NSTATS
; i
++) {
2540 unsigned long x
= per_cpu(memcg
->stat
->events
[i
], cpu
);
2542 per_cpu(memcg
->stat
->events
[i
], cpu
) = 0;
2543 memcg
->nocpu_base
.events
[i
] += x
;
2545 spin_unlock(&memcg
->pcp_counter_lock
);
2548 static int __cpuinit
memcg_cpu_hotplug_callback(struct notifier_block
*nb
,
2549 unsigned long action
,
2552 int cpu
= (unsigned long)hcpu
;
2553 struct memcg_stock_pcp
*stock
;
2554 struct mem_cgroup
*iter
;
2556 if (action
== CPU_ONLINE
)
2559 if (action
!= CPU_DEAD
&& action
!= CPU_DEAD_FROZEN
)
2562 for_each_mem_cgroup(iter
)
2563 mem_cgroup_drain_pcp_counter(iter
, cpu
);
2565 stock
= &per_cpu(memcg_stock
, cpu
);
2571 /* See __mem_cgroup_try_charge() for details */
2573 CHARGE_OK
, /* success */
2574 CHARGE_RETRY
, /* need to retry but retry is not bad */
2575 CHARGE_NOMEM
, /* we can't do more. return -ENOMEM */
2576 CHARGE_WOULDBLOCK
, /* GFP_WAIT wasn't set and no enough res. */
2577 CHARGE_OOM_DIE
, /* the current is killed because of OOM */
2580 static int mem_cgroup_do_charge(struct mem_cgroup
*memcg
, gfp_t gfp_mask
,
2581 unsigned int nr_pages
, unsigned int min_pages
,
2584 unsigned long csize
= nr_pages
* PAGE_SIZE
;
2585 struct mem_cgroup
*mem_over_limit
;
2586 struct res_counter
*fail_res
;
2587 unsigned long flags
= 0;
2590 ret
= res_counter_charge(&memcg
->res
, csize
, &fail_res
);
2593 if (!do_swap_account
)
2595 ret
= res_counter_charge(&memcg
->memsw
, csize
, &fail_res
);
2599 res_counter_uncharge(&memcg
->res
, csize
);
2600 mem_over_limit
= mem_cgroup_from_res_counter(fail_res
, memsw
);
2601 flags
|= MEM_CGROUP_RECLAIM_NOSWAP
;
2603 mem_over_limit
= mem_cgroup_from_res_counter(fail_res
, res
);
2605 * Never reclaim on behalf of optional batching, retry with a
2606 * single page instead.
2608 if (nr_pages
> min_pages
)
2609 return CHARGE_RETRY
;
2611 if (!(gfp_mask
& __GFP_WAIT
))
2612 return CHARGE_WOULDBLOCK
;
2614 if (gfp_mask
& __GFP_NORETRY
)
2615 return CHARGE_NOMEM
;
2617 ret
= mem_cgroup_reclaim(mem_over_limit
, gfp_mask
, flags
);
2618 if (mem_cgroup_margin(mem_over_limit
) >= nr_pages
)
2619 return CHARGE_RETRY
;
2621 * Even though the limit is exceeded at this point, reclaim
2622 * may have been able to free some pages. Retry the charge
2623 * before killing the task.
2625 * Only for regular pages, though: huge pages are rather
2626 * unlikely to succeed so close to the limit, and we fall back
2627 * to regular pages anyway in case of failure.
2629 if (nr_pages
<= (1 << PAGE_ALLOC_COSTLY_ORDER
) && ret
)
2630 return CHARGE_RETRY
;
2633 * At task move, charge accounts can be doubly counted. So, it's
2634 * better to wait until the end of task_move if something is going on.
2636 if (mem_cgroup_wait_acct_move(mem_over_limit
))
2637 return CHARGE_RETRY
;
2639 /* If we don't need to call oom-killer at el, return immediately */
2641 return CHARGE_NOMEM
;
2643 if (!mem_cgroup_handle_oom(mem_over_limit
, gfp_mask
, get_order(csize
)))
2644 return CHARGE_OOM_DIE
;
2646 return CHARGE_RETRY
;
2650 * __mem_cgroup_try_charge() does
2651 * 1. detect memcg to be charged against from passed *mm and *ptr,
2652 * 2. update res_counter
2653 * 3. call memory reclaim if necessary.
2655 * In some special case, if the task is fatal, fatal_signal_pending() or
2656 * has TIF_MEMDIE, this function returns -EINTR while writing root_mem_cgroup
2657 * to *ptr. There are two reasons for this. 1: fatal threads should quit as soon
2658 * as possible without any hazards. 2: all pages should have a valid
2659 * pc->mem_cgroup. If mm is NULL and the caller doesn't pass a valid memcg
2660 * pointer, that is treated as a charge to root_mem_cgroup.
2662 * So __mem_cgroup_try_charge() will return
2663 * 0 ... on success, filling *ptr with a valid memcg pointer.
2664 * -ENOMEM ... charge failure because of resource limits.
2665 * -EINTR ... if thread is fatal. *ptr is filled with root_mem_cgroup.
2667 * Unlike the exported interface, an "oom" parameter is added. if oom==true,
2668 * the oom-killer can be invoked.
2670 static int __mem_cgroup_try_charge(struct mm_struct
*mm
,
2672 unsigned int nr_pages
,
2673 struct mem_cgroup
**ptr
,
2676 unsigned int batch
= max(CHARGE_BATCH
, nr_pages
);
2677 int nr_oom_retries
= MEM_CGROUP_RECLAIM_RETRIES
;
2678 struct mem_cgroup
*memcg
= NULL
;
2682 * Unlike gloval-vm's OOM-kill, we're not in memory shortage
2683 * in system level. So, allow to go ahead dying process in addition to
2686 if (unlikely(test_thread_flag(TIF_MEMDIE
)
2687 || fatal_signal_pending(current
)))
2691 * We always charge the cgroup the mm_struct belongs to.
2692 * The mm_struct's mem_cgroup changes on task migration if the
2693 * thread group leader migrates. It's possible that mm is not
2694 * set, if so charge the root memcg (happens for pagecache usage).
2697 *ptr
= root_mem_cgroup
;
2699 if (*ptr
) { /* css should be a valid one */
2701 if (mem_cgroup_is_root(memcg
))
2703 if (consume_stock(memcg
, nr_pages
))
2705 css_get(&memcg
->css
);
2707 struct task_struct
*p
;
2710 p
= rcu_dereference(mm
->owner
);
2712 * Because we don't have task_lock(), "p" can exit.
2713 * In that case, "memcg" can point to root or p can be NULL with
2714 * race with swapoff. Then, we have small risk of mis-accouning.
2715 * But such kind of mis-account by race always happens because
2716 * we don't have cgroup_mutex(). It's overkill and we allo that
2718 * (*) swapoff at el will charge against mm-struct not against
2719 * task-struct. So, mm->owner can be NULL.
2721 memcg
= mem_cgroup_from_task(p
);
2723 memcg
= root_mem_cgroup
;
2724 if (mem_cgroup_is_root(memcg
)) {
2728 if (consume_stock(memcg
, nr_pages
)) {
2730 * It seems dagerous to access memcg without css_get().
2731 * But considering how consume_stok works, it's not
2732 * necessary. If consume_stock success, some charges
2733 * from this memcg are cached on this cpu. So, we
2734 * don't need to call css_get()/css_tryget() before
2735 * calling consume_stock().
2740 /* after here, we may be blocked. we need to get refcnt */
2741 if (!css_tryget(&memcg
->css
)) {
2751 /* If killed, bypass charge */
2752 if (fatal_signal_pending(current
)) {
2753 css_put(&memcg
->css
);
2758 if (oom
&& !nr_oom_retries
) {
2760 nr_oom_retries
= MEM_CGROUP_RECLAIM_RETRIES
;
2763 ret
= mem_cgroup_do_charge(memcg
, gfp_mask
, batch
, nr_pages
,
2768 case CHARGE_RETRY
: /* not in OOM situation but retry */
2770 css_put(&memcg
->css
);
2773 case CHARGE_WOULDBLOCK
: /* !__GFP_WAIT */
2774 css_put(&memcg
->css
);
2776 case CHARGE_NOMEM
: /* OOM routine works */
2778 css_put(&memcg
->css
);
2781 /* If oom, we never return -ENOMEM */
2784 case CHARGE_OOM_DIE
: /* Killed by OOM Killer */
2785 css_put(&memcg
->css
);
2788 } while (ret
!= CHARGE_OK
);
2790 if (batch
> nr_pages
)
2791 refill_stock(memcg
, batch
- nr_pages
);
2792 css_put(&memcg
->css
);
2800 *ptr
= root_mem_cgroup
;
2805 * Somemtimes we have to undo a charge we got by try_charge().
2806 * This function is for that and do uncharge, put css's refcnt.
2807 * gotten by try_charge().
2809 static void __mem_cgroup_cancel_charge(struct mem_cgroup
*memcg
,
2810 unsigned int nr_pages
)
2812 if (!mem_cgroup_is_root(memcg
)) {
2813 unsigned long bytes
= nr_pages
* PAGE_SIZE
;
2815 res_counter_uncharge(&memcg
->res
, bytes
);
2816 if (do_swap_account
)
2817 res_counter_uncharge(&memcg
->memsw
, bytes
);
2822 * Cancel chrages in this cgroup....doesn't propagate to parent cgroup.
2823 * This is useful when moving usage to parent cgroup.
2825 static void __mem_cgroup_cancel_local_charge(struct mem_cgroup
*memcg
,
2826 unsigned int nr_pages
)
2828 unsigned long bytes
= nr_pages
* PAGE_SIZE
;
2830 if (mem_cgroup_is_root(memcg
))
2833 res_counter_uncharge_until(&memcg
->res
, memcg
->res
.parent
, bytes
);
2834 if (do_swap_account
)
2835 res_counter_uncharge_until(&memcg
->memsw
,
2836 memcg
->memsw
.parent
, bytes
);
2840 * A helper function to get mem_cgroup from ID. must be called under
2841 * rcu_read_lock(). The caller is responsible for calling css_tryget if
2842 * the mem_cgroup is used for charging. (dropping refcnt from swap can be
2843 * called against removed memcg.)
2845 static struct mem_cgroup
*mem_cgroup_lookup(unsigned short id
)
2847 struct cgroup_subsys_state
*css
;
2849 /* ID 0 is unused ID */
2852 css
= css_lookup(&mem_cgroup_subsys
, id
);
2855 return mem_cgroup_from_css(css
);
2858 struct mem_cgroup
*try_get_mem_cgroup_from_page(struct page
*page
)
2860 struct mem_cgroup
*memcg
= NULL
;
2861 struct page_cgroup
*pc
;
2865 VM_BUG_ON(!PageLocked(page
));
2867 pc
= lookup_page_cgroup(page
);
2868 lock_page_cgroup(pc
);
2869 if (PageCgroupUsed(pc
)) {
2870 memcg
= pc
->mem_cgroup
;
2871 if (memcg
&& !css_tryget(&memcg
->css
))
2873 } else if (PageSwapCache(page
)) {
2874 ent
.val
= page_private(page
);
2875 id
= lookup_swap_cgroup_id(ent
);
2877 memcg
= mem_cgroup_lookup(id
);
2878 if (memcg
&& !css_tryget(&memcg
->css
))
2882 unlock_page_cgroup(pc
);
2886 static void __mem_cgroup_commit_charge(struct mem_cgroup
*memcg
,
2888 unsigned int nr_pages
,
2889 enum charge_type ctype
,
2892 struct page_cgroup
*pc
= lookup_page_cgroup(page
);
2893 struct zone
*uninitialized_var(zone
);
2894 struct lruvec
*lruvec
;
2895 bool was_on_lru
= false;
2898 lock_page_cgroup(pc
);
2899 VM_BUG_ON(PageCgroupUsed(pc
));
2901 * we don't need page_cgroup_lock about tail pages, becase they are not
2902 * accessed by any other context at this point.
2906 * In some cases, SwapCache and FUSE(splice_buf->radixtree), the page
2907 * may already be on some other mem_cgroup's LRU. Take care of it.
2910 zone
= page_zone(page
);
2911 spin_lock_irq(&zone
->lru_lock
);
2912 if (PageLRU(page
)) {
2913 lruvec
= mem_cgroup_zone_lruvec(zone
, pc
->mem_cgroup
);
2915 del_page_from_lru_list(page
, lruvec
, page_lru(page
));
2920 pc
->mem_cgroup
= memcg
;
2922 * We access a page_cgroup asynchronously without lock_page_cgroup().
2923 * Especially when a page_cgroup is taken from a page, pc->mem_cgroup
2924 * is accessed after testing USED bit. To make pc->mem_cgroup visible
2925 * before USED bit, we need memory barrier here.
2926 * See mem_cgroup_add_lru_list(), etc.
2929 SetPageCgroupUsed(pc
);
2933 lruvec
= mem_cgroup_zone_lruvec(zone
, pc
->mem_cgroup
);
2934 VM_BUG_ON(PageLRU(page
));
2936 add_page_to_lru_list(page
, lruvec
, page_lru(page
));
2938 spin_unlock_irq(&zone
->lru_lock
);
2941 if (ctype
== MEM_CGROUP_CHARGE_TYPE_ANON
)
2946 mem_cgroup_charge_statistics(memcg
, page
, anon
, nr_pages
);
2947 unlock_page_cgroup(pc
);
2950 * "charge_statistics" updated event counter. Then, check it.
2951 * Insert ancestor (and ancestor's ancestors), to softlimit RB-tree.
2952 * if they exceeds softlimit.
2954 memcg_check_events(memcg
, page
);
2957 static DEFINE_MUTEX(set_limit_mutex
);
2959 #ifdef CONFIG_MEMCG_KMEM
2960 static inline bool memcg_can_account_kmem(struct mem_cgroup
*memcg
)
2962 return !mem_cgroup_disabled() && !mem_cgroup_is_root(memcg
) &&
2963 (memcg
->kmem_account_flags
& KMEM_ACCOUNTED_MASK
);
2967 * This is a bit cumbersome, but it is rarely used and avoids a backpointer
2968 * in the memcg_cache_params struct.
2970 static struct kmem_cache
*memcg_params_to_cache(struct memcg_cache_params
*p
)
2972 struct kmem_cache
*cachep
;
2974 VM_BUG_ON(p
->is_root_cache
);
2975 cachep
= p
->root_cache
;
2976 return cachep
->memcg_params
->memcg_caches
[memcg_cache_id(p
->memcg
)];
2979 #ifdef CONFIG_SLABINFO
2980 static int mem_cgroup_slabinfo_read(struct cgroup
*cont
, struct cftype
*cft
,
2983 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cont
);
2984 struct memcg_cache_params
*params
;
2986 if (!memcg_can_account_kmem(memcg
))
2989 print_slabinfo_header(m
);
2991 mutex_lock(&memcg
->slab_caches_mutex
);
2992 list_for_each_entry(params
, &memcg
->memcg_slab_caches
, list
)
2993 cache_show(memcg_params_to_cache(params
), m
);
2994 mutex_unlock(&memcg
->slab_caches_mutex
);
3000 static int memcg_charge_kmem(struct mem_cgroup
*memcg
, gfp_t gfp
, u64 size
)
3002 struct res_counter
*fail_res
;
3003 struct mem_cgroup
*_memcg
;
3007 ret
= res_counter_charge(&memcg
->kmem
, size
, &fail_res
);
3012 * Conditions under which we can wait for the oom_killer. Those are
3013 * the same conditions tested by the core page allocator
3015 may_oom
= (gfp
& __GFP_FS
) && !(gfp
& __GFP_NORETRY
);
3018 ret
= __mem_cgroup_try_charge(NULL
, gfp
, size
>> PAGE_SHIFT
,
3021 if (ret
== -EINTR
) {
3023 * __mem_cgroup_try_charge() chosed to bypass to root due to
3024 * OOM kill or fatal signal. Since our only options are to
3025 * either fail the allocation or charge it to this cgroup, do
3026 * it as a temporary condition. But we can't fail. From a
3027 * kmem/slab perspective, the cache has already been selected,
3028 * by mem_cgroup_kmem_get_cache(), so it is too late to change
3031 * This condition will only trigger if the task entered
3032 * memcg_charge_kmem in a sane state, but was OOM-killed during
3033 * __mem_cgroup_try_charge() above. Tasks that were already
3034 * dying when the allocation triggers should have been already
3035 * directed to the root cgroup in memcontrol.h
3037 res_counter_charge_nofail(&memcg
->res
, size
, &fail_res
);
3038 if (do_swap_account
)
3039 res_counter_charge_nofail(&memcg
->memsw
, size
,
3043 res_counter_uncharge(&memcg
->kmem
, size
);
3048 static void memcg_uncharge_kmem(struct mem_cgroup
*memcg
, u64 size
)
3050 res_counter_uncharge(&memcg
->res
, size
);
3051 if (do_swap_account
)
3052 res_counter_uncharge(&memcg
->memsw
, size
);
3055 if (res_counter_uncharge(&memcg
->kmem
, size
))
3059 * Releases a reference taken in kmem_cgroup_css_offline in case
3060 * this last uncharge is racing with the offlining code or it is
3061 * outliving the memcg existence.
3063 * The memory barrier imposed by test&clear is paired with the
3064 * explicit one in memcg_kmem_mark_dead().
3066 if (memcg_kmem_test_and_clear_dead(memcg
))
3067 css_put(&memcg
->css
);
3070 void memcg_cache_list_add(struct mem_cgroup
*memcg
, struct kmem_cache
*cachep
)
3075 mutex_lock(&memcg
->slab_caches_mutex
);
3076 list_add(&cachep
->memcg_params
->list
, &memcg
->memcg_slab_caches
);
3077 mutex_unlock(&memcg
->slab_caches_mutex
);
3081 * helper for acessing a memcg's index. It will be used as an index in the
3082 * child cache array in kmem_cache, and also to derive its name. This function
3083 * will return -1 when this is not a kmem-limited memcg.
3085 int memcg_cache_id(struct mem_cgroup
*memcg
)
3087 return memcg
? memcg
->kmemcg_id
: -1;
3091 * This ends up being protected by the set_limit mutex, during normal
3092 * operation, because that is its main call site.
3094 * But when we create a new cache, we can call this as well if its parent
3095 * is kmem-limited. That will have to hold set_limit_mutex as well.
3097 int memcg_update_cache_sizes(struct mem_cgroup
*memcg
)
3101 num
= ida_simple_get(&kmem_limited_groups
,
3102 0, MEMCG_CACHES_MAX_SIZE
, GFP_KERNEL
);
3106 * After this point, kmem_accounted (that we test atomically in
3107 * the beginning of this conditional), is no longer 0. This
3108 * guarantees only one process will set the following boolean
3109 * to true. We don't need test_and_set because we're protected
3110 * by the set_limit_mutex anyway.
3112 memcg_kmem_set_activated(memcg
);
3114 ret
= memcg_update_all_caches(num
+1);
3116 ida_simple_remove(&kmem_limited_groups
, num
);
3117 memcg_kmem_clear_activated(memcg
);
3121 memcg
->kmemcg_id
= num
;
3122 INIT_LIST_HEAD(&memcg
->memcg_slab_caches
);
3123 mutex_init(&memcg
->slab_caches_mutex
);
3127 static size_t memcg_caches_array_size(int num_groups
)
3130 if (num_groups
<= 0)
3133 size
= 2 * num_groups
;
3134 if (size
< MEMCG_CACHES_MIN_SIZE
)
3135 size
= MEMCG_CACHES_MIN_SIZE
;
3136 else if (size
> MEMCG_CACHES_MAX_SIZE
)
3137 size
= MEMCG_CACHES_MAX_SIZE
;
3143 * We should update the current array size iff all caches updates succeed. This
3144 * can only be done from the slab side. The slab mutex needs to be held when
3147 void memcg_update_array_size(int num
)
3149 if (num
> memcg_limited_groups_array_size
)
3150 memcg_limited_groups_array_size
= memcg_caches_array_size(num
);
3153 static void kmem_cache_destroy_work_func(struct work_struct
*w
);
3155 int memcg_update_cache_size(struct kmem_cache
*s
, int num_groups
)
3157 struct memcg_cache_params
*cur_params
= s
->memcg_params
;
3159 VM_BUG_ON(s
->memcg_params
&& !s
->memcg_params
->is_root_cache
);
3161 if (num_groups
> memcg_limited_groups_array_size
) {
3163 ssize_t size
= memcg_caches_array_size(num_groups
);
3165 size
*= sizeof(void *);
3166 size
+= sizeof(struct memcg_cache_params
);
3168 s
->memcg_params
= kzalloc(size
, GFP_KERNEL
);
3169 if (!s
->memcg_params
) {
3170 s
->memcg_params
= cur_params
;
3174 s
->memcg_params
->is_root_cache
= true;
3177 * There is the chance it will be bigger than
3178 * memcg_limited_groups_array_size, if we failed an allocation
3179 * in a cache, in which case all caches updated before it, will
3180 * have a bigger array.
3182 * But if that is the case, the data after
3183 * memcg_limited_groups_array_size is certainly unused
3185 for (i
= 0; i
< memcg_limited_groups_array_size
; i
++) {
3186 if (!cur_params
->memcg_caches
[i
])
3188 s
->memcg_params
->memcg_caches
[i
] =
3189 cur_params
->memcg_caches
[i
];
3193 * Ideally, we would wait until all caches succeed, and only
3194 * then free the old one. But this is not worth the extra
3195 * pointer per-cache we'd have to have for this.
3197 * It is not a big deal if some caches are left with a size
3198 * bigger than the others. And all updates will reset this
3206 int memcg_register_cache(struct mem_cgroup
*memcg
, struct kmem_cache
*s
,
3207 struct kmem_cache
*root_cache
)
3209 size_t size
= sizeof(struct memcg_cache_params
);
3211 if (!memcg_kmem_enabled())
3215 size
+= memcg_limited_groups_array_size
* sizeof(void *);
3217 s
->memcg_params
= kzalloc(size
, GFP_KERNEL
);
3218 if (!s
->memcg_params
)
3221 INIT_WORK(&s
->memcg_params
->destroy
,
3222 kmem_cache_destroy_work_func
);
3224 s
->memcg_params
->memcg
= memcg
;
3225 s
->memcg_params
->root_cache
= root_cache
;
3227 s
->memcg_params
->is_root_cache
= true;
3232 void memcg_release_cache(struct kmem_cache
*s
)
3234 struct kmem_cache
*root
;
3235 struct mem_cgroup
*memcg
;
3239 * This happens, for instance, when a root cache goes away before we
3242 if (!s
->memcg_params
)
3245 if (s
->memcg_params
->is_root_cache
)
3248 memcg
= s
->memcg_params
->memcg
;
3249 id
= memcg_cache_id(memcg
);
3251 root
= s
->memcg_params
->root_cache
;
3252 root
->memcg_params
->memcg_caches
[id
] = NULL
;
3254 mutex_lock(&memcg
->slab_caches_mutex
);
3255 list_del(&s
->memcg_params
->list
);
3256 mutex_unlock(&memcg
->slab_caches_mutex
);
3258 css_put(&memcg
->css
);
3260 kfree(s
->memcg_params
);
3264 * During the creation a new cache, we need to disable our accounting mechanism
3265 * altogether. This is true even if we are not creating, but rather just
3266 * enqueing new caches to be created.
3268 * This is because that process will trigger allocations; some visible, like
3269 * explicit kmallocs to auxiliary data structures, name strings and internal
3270 * cache structures; some well concealed, like INIT_WORK() that can allocate
3271 * objects during debug.
3273 * If any allocation happens during memcg_kmem_get_cache, we will recurse back
3274 * to it. This may not be a bounded recursion: since the first cache creation
3275 * failed to complete (waiting on the allocation), we'll just try to create the
3276 * cache again, failing at the same point.
3278 * memcg_kmem_get_cache is prepared to abort after seeing a positive count of
3279 * memcg_kmem_skip_account. So we enclose anything that might allocate memory
3280 * inside the following two functions.
3282 static inline void memcg_stop_kmem_account(void)
3284 VM_BUG_ON(!current
->mm
);
3285 current
->memcg_kmem_skip_account
++;
3288 static inline void memcg_resume_kmem_account(void)
3290 VM_BUG_ON(!current
->mm
);
3291 current
->memcg_kmem_skip_account
--;
3294 static void kmem_cache_destroy_work_func(struct work_struct
*w
)
3296 struct kmem_cache
*cachep
;
3297 struct memcg_cache_params
*p
;
3299 p
= container_of(w
, struct memcg_cache_params
, destroy
);
3301 cachep
= memcg_params_to_cache(p
);
3304 * If we get down to 0 after shrink, we could delete right away.
3305 * However, memcg_release_pages() already puts us back in the workqueue
3306 * in that case. If we proceed deleting, we'll get a dangling
3307 * reference, and removing the object from the workqueue in that case
3308 * is unnecessary complication. We are not a fast path.
3310 * Note that this case is fundamentally different from racing with
3311 * shrink_slab(): if memcg_cgroup_destroy_cache() is called in
3312 * kmem_cache_shrink, not only we would be reinserting a dead cache
3313 * into the queue, but doing so from inside the worker racing to
3316 * So if we aren't down to zero, we'll just schedule a worker and try
3319 if (atomic_read(&cachep
->memcg_params
->nr_pages
) != 0) {
3320 kmem_cache_shrink(cachep
);
3321 if (atomic_read(&cachep
->memcg_params
->nr_pages
) == 0)
3324 kmem_cache_destroy(cachep
);
3327 void mem_cgroup_destroy_cache(struct kmem_cache
*cachep
)
3329 if (!cachep
->memcg_params
->dead
)
3333 * There are many ways in which we can get here.
3335 * We can get to a memory-pressure situation while the delayed work is
3336 * still pending to run. The vmscan shrinkers can then release all
3337 * cache memory and get us to destruction. If this is the case, we'll
3338 * be executed twice, which is a bug (the second time will execute over
3339 * bogus data). In this case, cancelling the work should be fine.
3341 * But we can also get here from the worker itself, if
3342 * kmem_cache_shrink is enough to shake all the remaining objects and
3343 * get the page count to 0. In this case, we'll deadlock if we try to
3344 * cancel the work (the worker runs with an internal lock held, which
3345 * is the same lock we would hold for cancel_work_sync().)
3347 * Since we can't possibly know who got us here, just refrain from
3348 * running if there is already work pending
3350 if (work_pending(&cachep
->memcg_params
->destroy
))
3353 * We have to defer the actual destroying to a workqueue, because
3354 * we might currently be in a context that cannot sleep.
3356 schedule_work(&cachep
->memcg_params
->destroy
);
3360 * This lock protects updaters, not readers. We want readers to be as fast as
3361 * they can, and they will either see NULL or a valid cache value. Our model
3362 * allow them to see NULL, in which case the root memcg will be selected.
3364 * We need this lock because multiple allocations to the same cache from a non
3365 * will span more than one worker. Only one of them can create the cache.
3367 static DEFINE_MUTEX(memcg_cache_mutex
);
3370 * Called with memcg_cache_mutex held
3372 static struct kmem_cache
*kmem_cache_dup(struct mem_cgroup
*memcg
,
3373 struct kmem_cache
*s
)
3375 struct kmem_cache
*new;
3376 static char *tmp_name
= NULL
;
3378 lockdep_assert_held(&memcg_cache_mutex
);
3381 * kmem_cache_create_memcg duplicates the given name and
3382 * cgroup_name for this name requires RCU context.
3383 * This static temporary buffer is used to prevent from
3384 * pointless shortliving allocation.
3387 tmp_name
= kmalloc(PATH_MAX
, GFP_KERNEL
);
3393 snprintf(tmp_name
, PATH_MAX
, "%s(%d:%s)", s
->name
,
3394 memcg_cache_id(memcg
), cgroup_name(memcg
->css
.cgroup
));
3397 new = kmem_cache_create_memcg(memcg
, tmp_name
, s
->object_size
, s
->align
,
3398 (s
->flags
& ~SLAB_PANIC
), s
->ctor
, s
);
3401 new->allocflags
|= __GFP_KMEMCG
;
3406 static struct kmem_cache
*memcg_create_kmem_cache(struct mem_cgroup
*memcg
,
3407 struct kmem_cache
*cachep
)
3409 struct kmem_cache
*new_cachep
;
3412 BUG_ON(!memcg_can_account_kmem(memcg
));
3414 idx
= memcg_cache_id(memcg
);
3416 mutex_lock(&memcg_cache_mutex
);
3417 new_cachep
= cachep
->memcg_params
->memcg_caches
[idx
];
3419 css_put(&memcg
->css
);
3423 new_cachep
= kmem_cache_dup(memcg
, cachep
);
3424 if (new_cachep
== NULL
) {
3425 new_cachep
= cachep
;
3426 css_put(&memcg
->css
);
3430 atomic_set(&new_cachep
->memcg_params
->nr_pages
, 0);
3432 cachep
->memcg_params
->memcg_caches
[idx
] = new_cachep
;
3434 * the readers won't lock, make sure everybody sees the updated value,
3435 * so they won't put stuff in the queue again for no reason
3439 mutex_unlock(&memcg_cache_mutex
);
3443 void kmem_cache_destroy_memcg_children(struct kmem_cache
*s
)
3445 struct kmem_cache
*c
;
3448 if (!s
->memcg_params
)
3450 if (!s
->memcg_params
->is_root_cache
)
3454 * If the cache is being destroyed, we trust that there is no one else
3455 * requesting objects from it. Even if there are, the sanity checks in
3456 * kmem_cache_destroy should caught this ill-case.
3458 * Still, we don't want anyone else freeing memcg_caches under our
3459 * noses, which can happen if a new memcg comes to life. As usual,
3460 * we'll take the set_limit_mutex to protect ourselves against this.
3462 mutex_lock(&set_limit_mutex
);
3463 for (i
= 0; i
< memcg_limited_groups_array_size
; i
++) {
3464 c
= s
->memcg_params
->memcg_caches
[i
];
3469 * We will now manually delete the caches, so to avoid races
3470 * we need to cancel all pending destruction workers and
3471 * proceed with destruction ourselves.
3473 * kmem_cache_destroy() will call kmem_cache_shrink internally,
3474 * and that could spawn the workers again: it is likely that
3475 * the cache still have active pages until this very moment.
3476 * This would lead us back to mem_cgroup_destroy_cache.
3478 * But that will not execute at all if the "dead" flag is not
3479 * set, so flip it down to guarantee we are in control.
3481 c
->memcg_params
->dead
= false;
3482 cancel_work_sync(&c
->memcg_params
->destroy
);
3483 kmem_cache_destroy(c
);
3485 mutex_unlock(&set_limit_mutex
);
3488 struct create_work
{
3489 struct mem_cgroup
*memcg
;
3490 struct kmem_cache
*cachep
;
3491 struct work_struct work
;
3494 static void mem_cgroup_destroy_all_caches(struct mem_cgroup
*memcg
)
3496 struct kmem_cache
*cachep
;
3497 struct memcg_cache_params
*params
;
3499 if (!memcg_kmem_is_active(memcg
))
3502 mutex_lock(&memcg
->slab_caches_mutex
);
3503 list_for_each_entry(params
, &memcg
->memcg_slab_caches
, list
) {
3504 cachep
= memcg_params_to_cache(params
);
3505 cachep
->memcg_params
->dead
= true;
3506 schedule_work(&cachep
->memcg_params
->destroy
);
3508 mutex_unlock(&memcg
->slab_caches_mutex
);
3511 static void memcg_create_cache_work_func(struct work_struct
*w
)
3513 struct create_work
*cw
;
3515 cw
= container_of(w
, struct create_work
, work
);
3516 memcg_create_kmem_cache(cw
->memcg
, cw
->cachep
);
3521 * Enqueue the creation of a per-memcg kmem_cache.
3523 static void __memcg_create_cache_enqueue(struct mem_cgroup
*memcg
,
3524 struct kmem_cache
*cachep
)
3526 struct create_work
*cw
;
3528 cw
= kmalloc(sizeof(struct create_work
), GFP_NOWAIT
);
3530 css_put(&memcg
->css
);
3535 cw
->cachep
= cachep
;
3537 INIT_WORK(&cw
->work
, memcg_create_cache_work_func
);
3538 schedule_work(&cw
->work
);
3541 static void memcg_create_cache_enqueue(struct mem_cgroup
*memcg
,
3542 struct kmem_cache
*cachep
)
3545 * We need to stop accounting when we kmalloc, because if the
3546 * corresponding kmalloc cache is not yet created, the first allocation
3547 * in __memcg_create_cache_enqueue will recurse.
3549 * However, it is better to enclose the whole function. Depending on
3550 * the debugging options enabled, INIT_WORK(), for instance, can
3551 * trigger an allocation. This too, will make us recurse. Because at
3552 * this point we can't allow ourselves back into memcg_kmem_get_cache,
3553 * the safest choice is to do it like this, wrapping the whole function.
3555 memcg_stop_kmem_account();
3556 __memcg_create_cache_enqueue(memcg
, cachep
);
3557 memcg_resume_kmem_account();
3560 * Return the kmem_cache we're supposed to use for a slab allocation.
3561 * We try to use the current memcg's version of the cache.
3563 * If the cache does not exist yet, if we are the first user of it,
3564 * we either create it immediately, if possible, or create it asynchronously
3566 * In the latter case, we will let the current allocation go through with
3567 * the original cache.
3569 * Can't be called in interrupt context or from kernel threads.
3570 * This function needs to be called with rcu_read_lock() held.
3572 struct kmem_cache
*__memcg_kmem_get_cache(struct kmem_cache
*cachep
,
3575 struct mem_cgroup
*memcg
;
3578 VM_BUG_ON(!cachep
->memcg_params
);
3579 VM_BUG_ON(!cachep
->memcg_params
->is_root_cache
);
3581 if (!current
->mm
|| current
->memcg_kmem_skip_account
)
3585 memcg
= mem_cgroup_from_task(rcu_dereference(current
->mm
->owner
));
3587 if (!memcg_can_account_kmem(memcg
))
3590 idx
= memcg_cache_id(memcg
);
3593 * barrier to mare sure we're always seeing the up to date value. The
3594 * code updating memcg_caches will issue a write barrier to match this.
3596 read_barrier_depends();
3597 if (likely(cachep
->memcg_params
->memcg_caches
[idx
])) {
3598 cachep
= cachep
->memcg_params
->memcg_caches
[idx
];
3602 /* The corresponding put will be done in the workqueue. */
3603 if (!css_tryget(&memcg
->css
))
3608 * If we are in a safe context (can wait, and not in interrupt
3609 * context), we could be be predictable and return right away.
3610 * This would guarantee that the allocation being performed
3611 * already belongs in the new cache.
3613 * However, there are some clashes that can arrive from locking.
3614 * For instance, because we acquire the slab_mutex while doing
3615 * kmem_cache_dup, this means no further allocation could happen
3616 * with the slab_mutex held.
3618 * Also, because cache creation issue get_online_cpus(), this
3619 * creates a lock chain: memcg_slab_mutex -> cpu_hotplug_mutex,
3620 * that ends up reversed during cpu hotplug. (cpuset allocates
3621 * a bunch of GFP_KERNEL memory during cpuup). Due to all that,
3622 * better to defer everything.
3624 memcg_create_cache_enqueue(memcg
, cachep
);
3630 EXPORT_SYMBOL(__memcg_kmem_get_cache
);
3633 * We need to verify if the allocation against current->mm->owner's memcg is
3634 * possible for the given order. But the page is not allocated yet, so we'll
3635 * need a further commit step to do the final arrangements.
3637 * It is possible for the task to switch cgroups in this mean time, so at
3638 * commit time, we can't rely on task conversion any longer. We'll then use
3639 * the handle argument to return to the caller which cgroup we should commit
3640 * against. We could also return the memcg directly and avoid the pointer
3641 * passing, but a boolean return value gives better semantics considering
3642 * the compiled-out case as well.
3644 * Returning true means the allocation is possible.
3647 __memcg_kmem_newpage_charge(gfp_t gfp
, struct mem_cgroup
**_memcg
, int order
)
3649 struct mem_cgroup
*memcg
;
3655 * Disabling accounting is only relevant for some specific memcg
3656 * internal allocations. Therefore we would initially not have such
3657 * check here, since direct calls to the page allocator that are marked
3658 * with GFP_KMEMCG only happen outside memcg core. We are mostly
3659 * concerned with cache allocations, and by having this test at
3660 * memcg_kmem_get_cache, we are already able to relay the allocation to
3661 * the root cache and bypass the memcg cache altogether.
3663 * There is one exception, though: the SLUB allocator does not create
3664 * large order caches, but rather service large kmallocs directly from
3665 * the page allocator. Therefore, the following sequence when backed by
3666 * the SLUB allocator:
3668 * memcg_stop_kmem_account();
3669 * kmalloc(<large_number>)
3670 * memcg_resume_kmem_account();
3672 * would effectively ignore the fact that we should skip accounting,
3673 * since it will drive us directly to this function without passing
3674 * through the cache selector memcg_kmem_get_cache. Such large
3675 * allocations are extremely rare but can happen, for instance, for the
3676 * cache arrays. We bring this test here.
3678 if (!current
->mm
|| current
->memcg_kmem_skip_account
)
3681 memcg
= try_get_mem_cgroup_from_mm(current
->mm
);
3684 * very rare case described in mem_cgroup_from_task. Unfortunately there
3685 * isn't much we can do without complicating this too much, and it would
3686 * be gfp-dependent anyway. Just let it go
3688 if (unlikely(!memcg
))
3691 if (!memcg_can_account_kmem(memcg
)) {
3692 css_put(&memcg
->css
);
3696 ret
= memcg_charge_kmem(memcg
, gfp
, PAGE_SIZE
<< order
);
3700 css_put(&memcg
->css
);
3704 void __memcg_kmem_commit_charge(struct page
*page
, struct mem_cgroup
*memcg
,
3707 struct page_cgroup
*pc
;
3709 VM_BUG_ON(mem_cgroup_is_root(memcg
));
3711 /* The page allocation failed. Revert */
3713 memcg_uncharge_kmem(memcg
, PAGE_SIZE
<< order
);
3717 pc
= lookup_page_cgroup(page
);
3718 lock_page_cgroup(pc
);
3719 pc
->mem_cgroup
= memcg
;
3720 SetPageCgroupUsed(pc
);
3721 unlock_page_cgroup(pc
);
3724 void __memcg_kmem_uncharge_pages(struct page
*page
, int order
)
3726 struct mem_cgroup
*memcg
= NULL
;
3727 struct page_cgroup
*pc
;
3730 pc
= lookup_page_cgroup(page
);
3732 * Fast unlocked return. Theoretically might have changed, have to
3733 * check again after locking.
3735 if (!PageCgroupUsed(pc
))
3738 lock_page_cgroup(pc
);
3739 if (PageCgroupUsed(pc
)) {
3740 memcg
= pc
->mem_cgroup
;
3741 ClearPageCgroupUsed(pc
);
3743 unlock_page_cgroup(pc
);
3746 * We trust that only if there is a memcg associated with the page, it
3747 * is a valid allocation
3752 VM_BUG_ON(mem_cgroup_is_root(memcg
));
3753 memcg_uncharge_kmem(memcg
, PAGE_SIZE
<< order
);
3756 static inline void mem_cgroup_destroy_all_caches(struct mem_cgroup
*memcg
)
3759 #endif /* CONFIG_MEMCG_KMEM */
3761 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
3763 #define PCGF_NOCOPY_AT_SPLIT (1 << PCG_LOCK | 1 << PCG_MIGRATION)
3765 * Because tail pages are not marked as "used", set it. We're under
3766 * zone->lru_lock, 'splitting on pmd' and compound_lock.
3767 * charge/uncharge will be never happen and move_account() is done under
3768 * compound_lock(), so we don't have to take care of races.
3770 void mem_cgroup_split_huge_fixup(struct page
*head
)
3772 struct page_cgroup
*head_pc
= lookup_page_cgroup(head
);
3773 struct page_cgroup
*pc
;
3774 struct mem_cgroup
*memcg
;
3777 if (mem_cgroup_disabled())
3780 memcg
= head_pc
->mem_cgroup
;
3781 for (i
= 1; i
< HPAGE_PMD_NR
; i
++) {
3783 pc
->mem_cgroup
= memcg
;
3784 smp_wmb();/* see __commit_charge() */
3785 pc
->flags
= head_pc
->flags
& ~PCGF_NOCOPY_AT_SPLIT
;
3787 __this_cpu_sub(memcg
->stat
->count
[MEM_CGROUP_STAT_RSS_HUGE
],
3790 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
3793 * mem_cgroup_move_account - move account of the page
3795 * @nr_pages: number of regular pages (>1 for huge pages)
3796 * @pc: page_cgroup of the page.
3797 * @from: mem_cgroup which the page is moved from.
3798 * @to: mem_cgroup which the page is moved to. @from != @to.
3800 * The caller must confirm following.
3801 * - page is not on LRU (isolate_page() is useful.)
3802 * - compound_lock is held when nr_pages > 1
3804 * This function doesn't do "charge" to new cgroup and doesn't do "uncharge"
3807 static int mem_cgroup_move_account(struct page
*page
,
3808 unsigned int nr_pages
,
3809 struct page_cgroup
*pc
,
3810 struct mem_cgroup
*from
,
3811 struct mem_cgroup
*to
)
3813 unsigned long flags
;
3815 bool anon
= PageAnon(page
);
3817 VM_BUG_ON(from
== to
);
3818 VM_BUG_ON(PageLRU(page
));
3820 * The page is isolated from LRU. So, collapse function
3821 * will not handle this page. But page splitting can happen.
3822 * Do this check under compound_page_lock(). The caller should
3826 if (nr_pages
> 1 && !PageTransHuge(page
))
3829 lock_page_cgroup(pc
);
3832 if (!PageCgroupUsed(pc
) || pc
->mem_cgroup
!= from
)
3835 move_lock_mem_cgroup(from
, &flags
);
3837 if (!anon
&& page_mapped(page
)) {
3838 /* Update mapped_file data for mem_cgroup */
3840 __this_cpu_dec(from
->stat
->count
[MEM_CGROUP_STAT_FILE_MAPPED
]);
3841 __this_cpu_inc(to
->stat
->count
[MEM_CGROUP_STAT_FILE_MAPPED
]);
3844 mem_cgroup_charge_statistics(from
, page
, anon
, -nr_pages
);
3846 /* caller should have done css_get */
3847 pc
->mem_cgroup
= to
;
3848 mem_cgroup_charge_statistics(to
, page
, anon
, nr_pages
);
3849 move_unlock_mem_cgroup(from
, &flags
);
3852 unlock_page_cgroup(pc
);
3856 memcg_check_events(to
, page
);
3857 memcg_check_events(from
, page
);
3863 * mem_cgroup_move_parent - moves page to the parent group
3864 * @page: the page to move
3865 * @pc: page_cgroup of the page
3866 * @child: page's cgroup
3868 * move charges to its parent or the root cgroup if the group has no
3869 * parent (aka use_hierarchy==0).
3870 * Although this might fail (get_page_unless_zero, isolate_lru_page or
3871 * mem_cgroup_move_account fails) the failure is always temporary and
3872 * it signals a race with a page removal/uncharge or migration. In the
3873 * first case the page is on the way out and it will vanish from the LRU
3874 * on the next attempt and the call should be retried later.
3875 * Isolation from the LRU fails only if page has been isolated from
3876 * the LRU since we looked at it and that usually means either global
3877 * reclaim or migration going on. The page will either get back to the
3879 * Finaly mem_cgroup_move_account fails only if the page got uncharged
3880 * (!PageCgroupUsed) or moved to a different group. The page will
3881 * disappear in the next attempt.
3883 static int mem_cgroup_move_parent(struct page
*page
,
3884 struct page_cgroup
*pc
,
3885 struct mem_cgroup
*child
)
3887 struct mem_cgroup
*parent
;
3888 unsigned int nr_pages
;
3889 unsigned long uninitialized_var(flags
);
3892 VM_BUG_ON(mem_cgroup_is_root(child
));
3895 if (!get_page_unless_zero(page
))
3897 if (isolate_lru_page(page
))
3900 nr_pages
= hpage_nr_pages(page
);
3902 parent
= parent_mem_cgroup(child
);
3904 * If no parent, move charges to root cgroup.
3907 parent
= root_mem_cgroup
;
3910 VM_BUG_ON(!PageTransHuge(page
));
3911 flags
= compound_lock_irqsave(page
);
3914 ret
= mem_cgroup_move_account(page
, nr_pages
,
3917 __mem_cgroup_cancel_local_charge(child
, nr_pages
);
3920 compound_unlock_irqrestore(page
, flags
);
3921 putback_lru_page(page
);
3929 * Charge the memory controller for page usage.
3931 * 0 if the charge was successful
3932 * < 0 if the cgroup is over its limit
3934 static int mem_cgroup_charge_common(struct page
*page
, struct mm_struct
*mm
,
3935 gfp_t gfp_mask
, enum charge_type ctype
)
3937 struct mem_cgroup
*memcg
= NULL
;
3938 unsigned int nr_pages
= 1;
3942 if (PageTransHuge(page
)) {
3943 nr_pages
<<= compound_order(page
);
3944 VM_BUG_ON(!PageTransHuge(page
));
3946 * Never OOM-kill a process for a huge page. The
3947 * fault handler will fall back to regular pages.
3952 ret
= __mem_cgroup_try_charge(mm
, gfp_mask
, nr_pages
, &memcg
, oom
);
3955 __mem_cgroup_commit_charge(memcg
, page
, nr_pages
, ctype
, false);
3959 int mem_cgroup_newpage_charge(struct page
*page
,
3960 struct mm_struct
*mm
, gfp_t gfp_mask
)
3962 if (mem_cgroup_disabled())
3964 VM_BUG_ON(page_mapped(page
));
3965 VM_BUG_ON(page
->mapping
&& !PageAnon(page
));
3967 return mem_cgroup_charge_common(page
, mm
, gfp_mask
,
3968 MEM_CGROUP_CHARGE_TYPE_ANON
);
3972 * While swap-in, try_charge -> commit or cancel, the page is locked.
3973 * And when try_charge() successfully returns, one refcnt to memcg without
3974 * struct page_cgroup is acquired. This refcnt will be consumed by
3975 * "commit()" or removed by "cancel()"
3977 static int __mem_cgroup_try_charge_swapin(struct mm_struct
*mm
,
3980 struct mem_cgroup
**memcgp
)
3982 struct mem_cgroup
*memcg
;
3983 struct page_cgroup
*pc
;
3986 pc
= lookup_page_cgroup(page
);
3988 * Every swap fault against a single page tries to charge the
3989 * page, bail as early as possible. shmem_unuse() encounters
3990 * already charged pages, too. The USED bit is protected by
3991 * the page lock, which serializes swap cache removal, which
3992 * in turn serializes uncharging.
3994 if (PageCgroupUsed(pc
))
3996 if (!do_swap_account
)
3998 memcg
= try_get_mem_cgroup_from_page(page
);
4002 ret
= __mem_cgroup_try_charge(NULL
, mask
, 1, memcgp
, true);
4003 css_put(&memcg
->css
);
4008 ret
= __mem_cgroup_try_charge(mm
, mask
, 1, memcgp
, true);
4014 int mem_cgroup_try_charge_swapin(struct mm_struct
*mm
, struct page
*page
,
4015 gfp_t gfp_mask
, struct mem_cgroup
**memcgp
)
4018 if (mem_cgroup_disabled())
4021 * A racing thread's fault, or swapoff, may have already
4022 * updated the pte, and even removed page from swap cache: in
4023 * those cases unuse_pte()'s pte_same() test will fail; but
4024 * there's also a KSM case which does need to charge the page.
4026 if (!PageSwapCache(page
)) {
4029 ret
= __mem_cgroup_try_charge(mm
, gfp_mask
, 1, memcgp
, true);
4034 return __mem_cgroup_try_charge_swapin(mm
, page
, gfp_mask
, memcgp
);
4037 void mem_cgroup_cancel_charge_swapin(struct mem_cgroup
*memcg
)
4039 if (mem_cgroup_disabled())
4043 __mem_cgroup_cancel_charge(memcg
, 1);
4047 __mem_cgroup_commit_charge_swapin(struct page
*page
, struct mem_cgroup
*memcg
,
4048 enum charge_type ctype
)
4050 if (mem_cgroup_disabled())
4055 __mem_cgroup_commit_charge(memcg
, page
, 1, ctype
, true);
4057 * Now swap is on-memory. This means this page may be
4058 * counted both as mem and swap....double count.
4059 * Fix it by uncharging from memsw. Basically, this SwapCache is stable
4060 * under lock_page(). But in do_swap_page()::memory.c, reuse_swap_page()
4061 * may call delete_from_swap_cache() before reach here.
4063 if (do_swap_account
&& PageSwapCache(page
)) {
4064 swp_entry_t ent
= {.val
= page_private(page
)};
4065 mem_cgroup_uncharge_swap(ent
);
4069 void mem_cgroup_commit_charge_swapin(struct page
*page
,
4070 struct mem_cgroup
*memcg
)
4072 __mem_cgroup_commit_charge_swapin(page
, memcg
,
4073 MEM_CGROUP_CHARGE_TYPE_ANON
);
4076 int mem_cgroup_cache_charge(struct page
*page
, struct mm_struct
*mm
,
4079 struct mem_cgroup
*memcg
= NULL
;
4080 enum charge_type type
= MEM_CGROUP_CHARGE_TYPE_CACHE
;
4083 if (mem_cgroup_disabled())
4085 if (PageCompound(page
))
4088 if (!PageSwapCache(page
))
4089 ret
= mem_cgroup_charge_common(page
, mm
, gfp_mask
, type
);
4090 else { /* page is swapcache/shmem */
4091 ret
= __mem_cgroup_try_charge_swapin(mm
, page
,
4094 __mem_cgroup_commit_charge_swapin(page
, memcg
, type
);
4099 static void mem_cgroup_do_uncharge(struct mem_cgroup
*memcg
,
4100 unsigned int nr_pages
,
4101 const enum charge_type ctype
)
4103 struct memcg_batch_info
*batch
= NULL
;
4104 bool uncharge_memsw
= true;
4106 /* If swapout, usage of swap doesn't decrease */
4107 if (!do_swap_account
|| ctype
== MEM_CGROUP_CHARGE_TYPE_SWAPOUT
)
4108 uncharge_memsw
= false;
4110 batch
= ¤t
->memcg_batch
;
4112 * In usual, we do css_get() when we remember memcg pointer.
4113 * But in this case, we keep res->usage until end of a series of
4114 * uncharges. Then, it's ok to ignore memcg's refcnt.
4117 batch
->memcg
= memcg
;
4119 * do_batch > 0 when unmapping pages or inode invalidate/truncate.
4120 * In those cases, all pages freed continuously can be expected to be in
4121 * the same cgroup and we have chance to coalesce uncharges.
4122 * But we do uncharge one by one if this is killed by OOM(TIF_MEMDIE)
4123 * because we want to do uncharge as soon as possible.
4126 if (!batch
->do_batch
|| test_thread_flag(TIF_MEMDIE
))
4127 goto direct_uncharge
;
4130 goto direct_uncharge
;
4133 * In typical case, batch->memcg == mem. This means we can
4134 * merge a series of uncharges to an uncharge of res_counter.
4135 * If not, we uncharge res_counter ony by one.
4137 if (batch
->memcg
!= memcg
)
4138 goto direct_uncharge
;
4139 /* remember freed charge and uncharge it later */
4142 batch
->memsw_nr_pages
++;
4145 res_counter_uncharge(&memcg
->res
, nr_pages
* PAGE_SIZE
);
4147 res_counter_uncharge(&memcg
->memsw
, nr_pages
* PAGE_SIZE
);
4148 if (unlikely(batch
->memcg
!= memcg
))
4149 memcg_oom_recover(memcg
);
4153 * uncharge if !page_mapped(page)
4155 static struct mem_cgroup
*
4156 __mem_cgroup_uncharge_common(struct page
*page
, enum charge_type ctype
,
4159 struct mem_cgroup
*memcg
= NULL
;
4160 unsigned int nr_pages
= 1;
4161 struct page_cgroup
*pc
;
4164 if (mem_cgroup_disabled())
4167 if (PageTransHuge(page
)) {
4168 nr_pages
<<= compound_order(page
);
4169 VM_BUG_ON(!PageTransHuge(page
));
4172 * Check if our page_cgroup is valid
4174 pc
= lookup_page_cgroup(page
);
4175 if (unlikely(!PageCgroupUsed(pc
)))
4178 lock_page_cgroup(pc
);
4180 memcg
= pc
->mem_cgroup
;
4182 if (!PageCgroupUsed(pc
))
4185 anon
= PageAnon(page
);
4188 case MEM_CGROUP_CHARGE_TYPE_ANON
:
4190 * Generally PageAnon tells if it's the anon statistics to be
4191 * updated; but sometimes e.g. mem_cgroup_uncharge_page() is
4192 * used before page reached the stage of being marked PageAnon.
4196 case MEM_CGROUP_CHARGE_TYPE_DROP
:
4197 /* See mem_cgroup_prepare_migration() */
4198 if (page_mapped(page
))
4201 * Pages under migration may not be uncharged. But
4202 * end_migration() /must/ be the one uncharging the
4203 * unused post-migration page and so it has to call
4204 * here with the migration bit still set. See the
4205 * res_counter handling below.
4207 if (!end_migration
&& PageCgroupMigration(pc
))
4210 case MEM_CGROUP_CHARGE_TYPE_SWAPOUT
:
4211 if (!PageAnon(page
)) { /* Shared memory */
4212 if (page
->mapping
&& !page_is_file_cache(page
))
4214 } else if (page_mapped(page
)) /* Anon */
4221 mem_cgroup_charge_statistics(memcg
, page
, anon
, -nr_pages
);
4223 ClearPageCgroupUsed(pc
);
4225 * pc->mem_cgroup is not cleared here. It will be accessed when it's
4226 * freed from LRU. This is safe because uncharged page is expected not
4227 * to be reused (freed soon). Exception is SwapCache, it's handled by
4228 * special functions.
4231 unlock_page_cgroup(pc
);
4233 * even after unlock, we have memcg->res.usage here and this memcg
4234 * will never be freed, so it's safe to call css_get().
4236 memcg_check_events(memcg
, page
);
4237 if (do_swap_account
&& ctype
== MEM_CGROUP_CHARGE_TYPE_SWAPOUT
) {
4238 mem_cgroup_swap_statistics(memcg
, true);
4239 css_get(&memcg
->css
);
4242 * Migration does not charge the res_counter for the
4243 * replacement page, so leave it alone when phasing out the
4244 * page that is unused after the migration.
4246 if (!end_migration
&& !mem_cgroup_is_root(memcg
))
4247 mem_cgroup_do_uncharge(memcg
, nr_pages
, ctype
);
4252 unlock_page_cgroup(pc
);
4256 void mem_cgroup_uncharge_page(struct page
*page
)
4259 if (page_mapped(page
))
4261 VM_BUG_ON(page
->mapping
&& !PageAnon(page
));
4263 * If the page is in swap cache, uncharge should be deferred
4264 * to the swap path, which also properly accounts swap usage
4265 * and handles memcg lifetime.
4267 * Note that this check is not stable and reclaim may add the
4268 * page to swap cache at any time after this. However, if the
4269 * page is not in swap cache by the time page->mapcount hits
4270 * 0, there won't be any page table references to the swap
4271 * slot, and reclaim will free it and not actually write the
4274 if (PageSwapCache(page
))
4276 __mem_cgroup_uncharge_common(page
, MEM_CGROUP_CHARGE_TYPE_ANON
, false);
4279 void mem_cgroup_uncharge_cache_page(struct page
*page
)
4281 VM_BUG_ON(page_mapped(page
));
4282 VM_BUG_ON(page
->mapping
);
4283 __mem_cgroup_uncharge_common(page
, MEM_CGROUP_CHARGE_TYPE_CACHE
, false);
4287 * Batch_start/batch_end is called in unmap_page_range/invlidate/trucate.
4288 * In that cases, pages are freed continuously and we can expect pages
4289 * are in the same memcg. All these calls itself limits the number of
4290 * pages freed at once, then uncharge_start/end() is called properly.
4291 * This may be called prural(2) times in a context,
4294 void mem_cgroup_uncharge_start(void)
4296 current
->memcg_batch
.do_batch
++;
4297 /* We can do nest. */
4298 if (current
->memcg_batch
.do_batch
== 1) {
4299 current
->memcg_batch
.memcg
= NULL
;
4300 current
->memcg_batch
.nr_pages
= 0;
4301 current
->memcg_batch
.memsw_nr_pages
= 0;
4305 void mem_cgroup_uncharge_end(void)
4307 struct memcg_batch_info
*batch
= ¤t
->memcg_batch
;
4309 if (!batch
->do_batch
)
4313 if (batch
->do_batch
) /* If stacked, do nothing. */
4319 * This "batch->memcg" is valid without any css_get/put etc...
4320 * bacause we hide charges behind us.
4322 if (batch
->nr_pages
)
4323 res_counter_uncharge(&batch
->memcg
->res
,
4324 batch
->nr_pages
* PAGE_SIZE
);
4325 if (batch
->memsw_nr_pages
)
4326 res_counter_uncharge(&batch
->memcg
->memsw
,
4327 batch
->memsw_nr_pages
* PAGE_SIZE
);
4328 memcg_oom_recover(batch
->memcg
);
4329 /* forget this pointer (for sanity check) */
4330 batch
->memcg
= NULL
;
4335 * called after __delete_from_swap_cache() and drop "page" account.
4336 * memcg information is recorded to swap_cgroup of "ent"
4339 mem_cgroup_uncharge_swapcache(struct page
*page
, swp_entry_t ent
, bool swapout
)
4341 struct mem_cgroup
*memcg
;
4342 int ctype
= MEM_CGROUP_CHARGE_TYPE_SWAPOUT
;
4344 if (!swapout
) /* this was a swap cache but the swap is unused ! */
4345 ctype
= MEM_CGROUP_CHARGE_TYPE_DROP
;
4347 memcg
= __mem_cgroup_uncharge_common(page
, ctype
, false);
4350 * record memcg information, if swapout && memcg != NULL,
4351 * css_get() was called in uncharge().
4353 if (do_swap_account
&& swapout
&& memcg
)
4354 swap_cgroup_record(ent
, css_id(&memcg
->css
));
4358 #ifdef CONFIG_MEMCG_SWAP
4360 * called from swap_entry_free(). remove record in swap_cgroup and
4361 * uncharge "memsw" account.
4363 void mem_cgroup_uncharge_swap(swp_entry_t ent
)
4365 struct mem_cgroup
*memcg
;
4368 if (!do_swap_account
)
4371 id
= swap_cgroup_record(ent
, 0);
4373 memcg
= mem_cgroup_lookup(id
);
4376 * We uncharge this because swap is freed.
4377 * This memcg can be obsolete one. We avoid calling css_tryget
4379 if (!mem_cgroup_is_root(memcg
))
4380 res_counter_uncharge(&memcg
->memsw
, PAGE_SIZE
);
4381 mem_cgroup_swap_statistics(memcg
, false);
4382 css_put(&memcg
->css
);
4388 * mem_cgroup_move_swap_account - move swap charge and swap_cgroup's record.
4389 * @entry: swap entry to be moved
4390 * @from: mem_cgroup which the entry is moved from
4391 * @to: mem_cgroup which the entry is moved to
4393 * It succeeds only when the swap_cgroup's record for this entry is the same
4394 * as the mem_cgroup's id of @from.
4396 * Returns 0 on success, -EINVAL on failure.
4398 * The caller must have charged to @to, IOW, called res_counter_charge() about
4399 * both res and memsw, and called css_get().
4401 static int mem_cgroup_move_swap_account(swp_entry_t entry
,
4402 struct mem_cgroup
*from
, struct mem_cgroup
*to
)
4404 unsigned short old_id
, new_id
;
4406 old_id
= css_id(&from
->css
);
4407 new_id
= css_id(&to
->css
);
4409 if (swap_cgroup_cmpxchg(entry
, old_id
, new_id
) == old_id
) {
4410 mem_cgroup_swap_statistics(from
, false);
4411 mem_cgroup_swap_statistics(to
, true);
4413 * This function is only called from task migration context now.
4414 * It postpones res_counter and refcount handling till the end
4415 * of task migration(mem_cgroup_clear_mc()) for performance
4416 * improvement. But we cannot postpone css_get(to) because if
4417 * the process that has been moved to @to does swap-in, the
4418 * refcount of @to might be decreased to 0.
4420 * We are in attach() phase, so the cgroup is guaranteed to be
4421 * alive, so we can just call css_get().
4429 static inline int mem_cgroup_move_swap_account(swp_entry_t entry
,
4430 struct mem_cgroup
*from
, struct mem_cgroup
*to
)
4437 * Before starting migration, account PAGE_SIZE to mem_cgroup that the old
4440 void mem_cgroup_prepare_migration(struct page
*page
, struct page
*newpage
,
4441 struct mem_cgroup
**memcgp
)
4443 struct mem_cgroup
*memcg
= NULL
;
4444 unsigned int nr_pages
= 1;
4445 struct page_cgroup
*pc
;
4446 enum charge_type ctype
;
4450 if (mem_cgroup_disabled())
4453 if (PageTransHuge(page
))
4454 nr_pages
<<= compound_order(page
);
4456 pc
= lookup_page_cgroup(page
);
4457 lock_page_cgroup(pc
);
4458 if (PageCgroupUsed(pc
)) {
4459 memcg
= pc
->mem_cgroup
;
4460 css_get(&memcg
->css
);
4462 * At migrating an anonymous page, its mapcount goes down
4463 * to 0 and uncharge() will be called. But, even if it's fully
4464 * unmapped, migration may fail and this page has to be
4465 * charged again. We set MIGRATION flag here and delay uncharge
4466 * until end_migration() is called
4468 * Corner Case Thinking
4470 * When the old page was mapped as Anon and it's unmap-and-freed
4471 * while migration was ongoing.
4472 * If unmap finds the old page, uncharge() of it will be delayed
4473 * until end_migration(). If unmap finds a new page, it's
4474 * uncharged when it make mapcount to be 1->0. If unmap code
4475 * finds swap_migration_entry, the new page will not be mapped
4476 * and end_migration() will find it(mapcount==0).
4479 * When the old page was mapped but migraion fails, the kernel
4480 * remaps it. A charge for it is kept by MIGRATION flag even
4481 * if mapcount goes down to 0. We can do remap successfully
4482 * without charging it again.
4485 * The "old" page is under lock_page() until the end of
4486 * migration, so, the old page itself will not be swapped-out.
4487 * If the new page is swapped out before end_migraton, our
4488 * hook to usual swap-out path will catch the event.
4491 SetPageCgroupMigration(pc
);
4493 unlock_page_cgroup(pc
);
4495 * If the page is not charged at this point,
4503 * We charge new page before it's used/mapped. So, even if unlock_page()
4504 * is called before end_migration, we can catch all events on this new
4505 * page. In the case new page is migrated but not remapped, new page's
4506 * mapcount will be finally 0 and we call uncharge in end_migration().
4509 ctype
= MEM_CGROUP_CHARGE_TYPE_ANON
;
4511 ctype
= MEM_CGROUP_CHARGE_TYPE_CACHE
;
4513 * The page is committed to the memcg, but it's not actually
4514 * charged to the res_counter since we plan on replacing the
4515 * old one and only one page is going to be left afterwards.
4517 __mem_cgroup_commit_charge(memcg
, newpage
, nr_pages
, ctype
, false);
4520 /* remove redundant charge if migration failed*/
4521 void mem_cgroup_end_migration(struct mem_cgroup
*memcg
,
4522 struct page
*oldpage
, struct page
*newpage
, bool migration_ok
)
4524 struct page
*used
, *unused
;
4525 struct page_cgroup
*pc
;
4531 if (!migration_ok
) {
4538 anon
= PageAnon(used
);
4539 __mem_cgroup_uncharge_common(unused
,
4540 anon
? MEM_CGROUP_CHARGE_TYPE_ANON
4541 : MEM_CGROUP_CHARGE_TYPE_CACHE
,
4543 css_put(&memcg
->css
);
4545 * We disallowed uncharge of pages under migration because mapcount
4546 * of the page goes down to zero, temporarly.
4547 * Clear the flag and check the page should be charged.
4549 pc
= lookup_page_cgroup(oldpage
);
4550 lock_page_cgroup(pc
);
4551 ClearPageCgroupMigration(pc
);
4552 unlock_page_cgroup(pc
);
4555 * If a page is a file cache, radix-tree replacement is very atomic
4556 * and we can skip this check. When it was an Anon page, its mapcount
4557 * goes down to 0. But because we added MIGRATION flage, it's not
4558 * uncharged yet. There are several case but page->mapcount check
4559 * and USED bit check in mem_cgroup_uncharge_page() will do enough
4560 * check. (see prepare_charge() also)
4563 mem_cgroup_uncharge_page(used
);
4567 * At replace page cache, newpage is not under any memcg but it's on
4568 * LRU. So, this function doesn't touch res_counter but handles LRU
4569 * in correct way. Both pages are locked so we cannot race with uncharge.
4571 void mem_cgroup_replace_page_cache(struct page
*oldpage
,
4572 struct page
*newpage
)
4574 struct mem_cgroup
*memcg
= NULL
;
4575 struct page_cgroup
*pc
;
4576 enum charge_type type
= MEM_CGROUP_CHARGE_TYPE_CACHE
;
4578 if (mem_cgroup_disabled())
4581 pc
= lookup_page_cgroup(oldpage
);
4582 /* fix accounting on old pages */
4583 lock_page_cgroup(pc
);
4584 if (PageCgroupUsed(pc
)) {
4585 memcg
= pc
->mem_cgroup
;
4586 mem_cgroup_charge_statistics(memcg
, oldpage
, false, -1);
4587 ClearPageCgroupUsed(pc
);
4589 unlock_page_cgroup(pc
);
4592 * When called from shmem_replace_page(), in some cases the
4593 * oldpage has already been charged, and in some cases not.
4598 * Even if newpage->mapping was NULL before starting replacement,
4599 * the newpage may be on LRU(or pagevec for LRU) already. We lock
4600 * LRU while we overwrite pc->mem_cgroup.
4602 __mem_cgroup_commit_charge(memcg
, newpage
, 1, type
, true);
4605 #ifdef CONFIG_DEBUG_VM
4606 static struct page_cgroup
*lookup_page_cgroup_used(struct page
*page
)
4608 struct page_cgroup
*pc
;
4610 pc
= lookup_page_cgroup(page
);
4612 * Can be NULL while feeding pages into the page allocator for
4613 * the first time, i.e. during boot or memory hotplug;
4614 * or when mem_cgroup_disabled().
4616 if (likely(pc
) && PageCgroupUsed(pc
))
4621 bool mem_cgroup_bad_page_check(struct page
*page
)
4623 if (mem_cgroup_disabled())
4626 return lookup_page_cgroup_used(page
) != NULL
;
4629 void mem_cgroup_print_bad_page(struct page
*page
)
4631 struct page_cgroup
*pc
;
4633 pc
= lookup_page_cgroup_used(page
);
4635 pr_alert("pc:%p pc->flags:%lx pc->mem_cgroup:%p\n",
4636 pc
, pc
->flags
, pc
->mem_cgroup
);
4641 static int mem_cgroup_resize_limit(struct mem_cgroup
*memcg
,
4642 unsigned long long val
)
4645 u64 memswlimit
, memlimit
;
4647 int children
= mem_cgroup_count_children(memcg
);
4648 u64 curusage
, oldusage
;
4652 * For keeping hierarchical_reclaim simple, how long we should retry
4653 * is depends on callers. We set our retry-count to be function
4654 * of # of children which we should visit in this loop.
4656 retry_count
= MEM_CGROUP_RECLAIM_RETRIES
* children
;
4658 oldusage
= res_counter_read_u64(&memcg
->res
, RES_USAGE
);
4661 while (retry_count
) {
4662 if (signal_pending(current
)) {
4667 * Rather than hide all in some function, I do this in
4668 * open coded manner. You see what this really does.
4669 * We have to guarantee memcg->res.limit <= memcg->memsw.limit.
4671 mutex_lock(&set_limit_mutex
);
4672 memswlimit
= res_counter_read_u64(&memcg
->memsw
, RES_LIMIT
);
4673 if (memswlimit
< val
) {
4675 mutex_unlock(&set_limit_mutex
);
4679 memlimit
= res_counter_read_u64(&memcg
->res
, RES_LIMIT
);
4683 ret
= res_counter_set_limit(&memcg
->res
, val
);
4685 if (memswlimit
== val
)
4686 memcg
->memsw_is_minimum
= true;
4688 memcg
->memsw_is_minimum
= false;
4690 mutex_unlock(&set_limit_mutex
);
4695 mem_cgroup_reclaim(memcg
, GFP_KERNEL
,
4696 MEM_CGROUP_RECLAIM_SHRINK
);
4697 curusage
= res_counter_read_u64(&memcg
->res
, RES_USAGE
);
4698 /* Usage is reduced ? */
4699 if (curusage
>= oldusage
)
4702 oldusage
= curusage
;
4704 if (!ret
&& enlarge
)
4705 memcg_oom_recover(memcg
);
4710 static int mem_cgroup_resize_memsw_limit(struct mem_cgroup
*memcg
,
4711 unsigned long long val
)
4714 u64 memlimit
, memswlimit
, oldusage
, curusage
;
4715 int children
= mem_cgroup_count_children(memcg
);
4719 /* see mem_cgroup_resize_res_limit */
4720 retry_count
= children
* MEM_CGROUP_RECLAIM_RETRIES
;
4721 oldusage
= res_counter_read_u64(&memcg
->memsw
, RES_USAGE
);
4722 while (retry_count
) {
4723 if (signal_pending(current
)) {
4728 * Rather than hide all in some function, I do this in
4729 * open coded manner. You see what this really does.
4730 * We have to guarantee memcg->res.limit <= memcg->memsw.limit.
4732 mutex_lock(&set_limit_mutex
);
4733 memlimit
= res_counter_read_u64(&memcg
->res
, RES_LIMIT
);
4734 if (memlimit
> val
) {
4736 mutex_unlock(&set_limit_mutex
);
4739 memswlimit
= res_counter_read_u64(&memcg
->memsw
, RES_LIMIT
);
4740 if (memswlimit
< val
)
4742 ret
= res_counter_set_limit(&memcg
->memsw
, val
);
4744 if (memlimit
== val
)
4745 memcg
->memsw_is_minimum
= true;
4747 memcg
->memsw_is_minimum
= false;
4749 mutex_unlock(&set_limit_mutex
);
4754 mem_cgroup_reclaim(memcg
, GFP_KERNEL
,
4755 MEM_CGROUP_RECLAIM_NOSWAP
|
4756 MEM_CGROUP_RECLAIM_SHRINK
);
4757 curusage
= res_counter_read_u64(&memcg
->memsw
, RES_USAGE
);
4758 /* Usage is reduced ? */
4759 if (curusage
>= oldusage
)
4762 oldusage
= curusage
;
4764 if (!ret
&& enlarge
)
4765 memcg_oom_recover(memcg
);
4769 unsigned long mem_cgroup_soft_limit_reclaim(struct zone
*zone
, int order
,
4771 unsigned long *total_scanned
)
4773 unsigned long nr_reclaimed
= 0;
4774 struct mem_cgroup_per_zone
*mz
, *next_mz
= NULL
;
4775 unsigned long reclaimed
;
4777 struct mem_cgroup_tree_per_zone
*mctz
;
4778 unsigned long long excess
;
4779 unsigned long nr_scanned
;
4784 mctz
= soft_limit_tree_node_zone(zone_to_nid(zone
), zone_idx(zone
));
4786 * This loop can run a while, specially if mem_cgroup's continuously
4787 * keep exceeding their soft limit and putting the system under
4794 mz
= mem_cgroup_largest_soft_limit_node(mctz
);
4799 reclaimed
= mem_cgroup_soft_reclaim(mz
->memcg
, zone
,
4800 gfp_mask
, &nr_scanned
);
4801 nr_reclaimed
+= reclaimed
;
4802 *total_scanned
+= nr_scanned
;
4803 spin_lock(&mctz
->lock
);
4806 * If we failed to reclaim anything from this memory cgroup
4807 * it is time to move on to the next cgroup
4813 * Loop until we find yet another one.
4815 * By the time we get the soft_limit lock
4816 * again, someone might have aded the
4817 * group back on the RB tree. Iterate to
4818 * make sure we get a different mem.
4819 * mem_cgroup_largest_soft_limit_node returns
4820 * NULL if no other cgroup is present on
4824 __mem_cgroup_largest_soft_limit_node(mctz
);
4826 css_put(&next_mz
->memcg
->css
);
4827 else /* next_mz == NULL or other memcg */
4831 __mem_cgroup_remove_exceeded(mz
->memcg
, mz
, mctz
);
4832 excess
= res_counter_soft_limit_excess(&mz
->memcg
->res
);
4834 * One school of thought says that we should not add
4835 * back the node to the tree if reclaim returns 0.
4836 * But our reclaim could return 0, simply because due
4837 * to priority we are exposing a smaller subset of
4838 * memory to reclaim from. Consider this as a longer
4841 /* If excess == 0, no tree ops */
4842 __mem_cgroup_insert_exceeded(mz
->memcg
, mz
, mctz
, excess
);
4843 spin_unlock(&mctz
->lock
);
4844 css_put(&mz
->memcg
->css
);
4847 * Could not reclaim anything and there are no more
4848 * mem cgroups to try or we seem to be looping without
4849 * reclaiming anything.
4851 if (!nr_reclaimed
&&
4853 loop
> MEM_CGROUP_MAX_SOFT_LIMIT_RECLAIM_LOOPS
))
4855 } while (!nr_reclaimed
);
4857 css_put(&next_mz
->memcg
->css
);
4858 return nr_reclaimed
;
4862 * mem_cgroup_force_empty_list - clears LRU of a group
4863 * @memcg: group to clear
4866 * @lru: lru to to clear
4868 * Traverse a specified page_cgroup list and try to drop them all. This doesn't
4869 * reclaim the pages page themselves - pages are moved to the parent (or root)
4872 static void mem_cgroup_force_empty_list(struct mem_cgroup
*memcg
,
4873 int node
, int zid
, enum lru_list lru
)
4875 struct lruvec
*lruvec
;
4876 unsigned long flags
;
4877 struct list_head
*list
;
4881 zone
= &NODE_DATA(node
)->node_zones
[zid
];
4882 lruvec
= mem_cgroup_zone_lruvec(zone
, memcg
);
4883 list
= &lruvec
->lists
[lru
];
4887 struct page_cgroup
*pc
;
4890 spin_lock_irqsave(&zone
->lru_lock
, flags
);
4891 if (list_empty(list
)) {
4892 spin_unlock_irqrestore(&zone
->lru_lock
, flags
);
4895 page
= list_entry(list
->prev
, struct page
, lru
);
4897 list_move(&page
->lru
, list
);
4899 spin_unlock_irqrestore(&zone
->lru_lock
, flags
);
4902 spin_unlock_irqrestore(&zone
->lru_lock
, flags
);
4904 pc
= lookup_page_cgroup(page
);
4906 if (mem_cgroup_move_parent(page
, pc
, memcg
)) {
4907 /* found lock contention or "pc" is obsolete. */
4912 } while (!list_empty(list
));
4916 * make mem_cgroup's charge to be 0 if there is no task by moving
4917 * all the charges and pages to the parent.
4918 * This enables deleting this mem_cgroup.
4920 * Caller is responsible for holding css reference on the memcg.
4922 static void mem_cgroup_reparent_charges(struct mem_cgroup
*memcg
)
4928 /* This is for making all *used* pages to be on LRU. */
4929 lru_add_drain_all();
4930 drain_all_stock_sync(memcg
);
4931 mem_cgroup_start_move(memcg
);
4932 for_each_node_state(node
, N_MEMORY
) {
4933 for (zid
= 0; zid
< MAX_NR_ZONES
; zid
++) {
4936 mem_cgroup_force_empty_list(memcg
,
4941 mem_cgroup_end_move(memcg
);
4942 memcg_oom_recover(memcg
);
4946 * Kernel memory may not necessarily be trackable to a specific
4947 * process. So they are not migrated, and therefore we can't
4948 * expect their value to drop to 0 here.
4949 * Having res filled up with kmem only is enough.
4951 * This is a safety check because mem_cgroup_force_empty_list
4952 * could have raced with mem_cgroup_replace_page_cache callers
4953 * so the lru seemed empty but the page could have been added
4954 * right after the check. RES_USAGE should be safe as we always
4955 * charge before adding to the LRU.
4957 usage
= res_counter_read_u64(&memcg
->res
, RES_USAGE
) -
4958 res_counter_read_u64(&memcg
->kmem
, RES_USAGE
);
4959 } while (usage
> 0);
4963 * This mainly exists for tests during the setting of set of use_hierarchy.
4964 * Since this is the very setting we are changing, the current hierarchy value
4967 static inline bool __memcg_has_children(struct mem_cgroup
*memcg
)
4971 /* bounce at first found */
4972 cgroup_for_each_child(pos
, memcg
->css
.cgroup
)
4978 * Must be called with memcg_create_mutex held, unless the cgroup is guaranteed
4979 * to be already dead (as in mem_cgroup_force_empty, for instance). This is
4980 * from mem_cgroup_count_children(), in the sense that we don't really care how
4981 * many children we have; we only need to know if we have any. It also counts
4982 * any memcg without hierarchy as infertile.
4984 static inline bool memcg_has_children(struct mem_cgroup
*memcg
)
4986 return memcg
->use_hierarchy
&& __memcg_has_children(memcg
);
4990 * Reclaims as many pages from the given memcg as possible and moves
4991 * the rest to the parent.
4993 * Caller is responsible for holding css reference for memcg.
4995 static int mem_cgroup_force_empty(struct mem_cgroup
*memcg
)
4997 int nr_retries
= MEM_CGROUP_RECLAIM_RETRIES
;
4998 struct cgroup
*cgrp
= memcg
->css
.cgroup
;
5000 /* returns EBUSY if there is a task or if we come here twice. */
5001 if (cgroup_task_count(cgrp
) || !list_empty(&cgrp
->children
))
5004 /* we call try-to-free pages for make this cgroup empty */
5005 lru_add_drain_all();
5006 /* try to free all pages in this cgroup */
5007 while (nr_retries
&& res_counter_read_u64(&memcg
->res
, RES_USAGE
) > 0) {
5010 if (signal_pending(current
))
5013 progress
= try_to_free_mem_cgroup_pages(memcg
, GFP_KERNEL
,
5017 /* maybe some writeback is necessary */
5018 congestion_wait(BLK_RW_ASYNC
, HZ
/10);
5023 mem_cgroup_reparent_charges(memcg
);
5028 static int mem_cgroup_force_empty_write(struct cgroup
*cont
, unsigned int event
)
5030 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cont
);
5033 if (mem_cgroup_is_root(memcg
))
5035 css_get(&memcg
->css
);
5036 ret
= mem_cgroup_force_empty(memcg
);
5037 css_put(&memcg
->css
);
5043 static u64
mem_cgroup_hierarchy_read(struct cgroup
*cont
, struct cftype
*cft
)
5045 return mem_cgroup_from_cont(cont
)->use_hierarchy
;
5048 static int mem_cgroup_hierarchy_write(struct cgroup
*cont
, struct cftype
*cft
,
5052 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cont
);
5053 struct cgroup
*parent
= cont
->parent
;
5054 struct mem_cgroup
*parent_memcg
= NULL
;
5057 parent_memcg
= mem_cgroup_from_cont(parent
);
5059 mutex_lock(&memcg_create_mutex
);
5061 if (memcg
->use_hierarchy
== val
)
5065 * If parent's use_hierarchy is set, we can't make any modifications
5066 * in the child subtrees. If it is unset, then the change can
5067 * occur, provided the current cgroup has no children.
5069 * For the root cgroup, parent_mem is NULL, we allow value to be
5070 * set if there are no children.
5072 if ((!parent_memcg
|| !parent_memcg
->use_hierarchy
) &&
5073 (val
== 1 || val
== 0)) {
5074 if (!__memcg_has_children(memcg
))
5075 memcg
->use_hierarchy
= val
;
5082 mutex_unlock(&memcg_create_mutex
);
5088 static unsigned long mem_cgroup_recursive_stat(struct mem_cgroup
*memcg
,
5089 enum mem_cgroup_stat_index idx
)
5091 struct mem_cgroup
*iter
;
5094 /* Per-cpu values can be negative, use a signed accumulator */
5095 for_each_mem_cgroup_tree(iter
, memcg
)
5096 val
+= mem_cgroup_read_stat(iter
, idx
);
5098 if (val
< 0) /* race ? */
5103 static inline u64
mem_cgroup_usage(struct mem_cgroup
*memcg
, bool swap
)
5107 if (!mem_cgroup_is_root(memcg
)) {
5109 return res_counter_read_u64(&memcg
->res
, RES_USAGE
);
5111 return res_counter_read_u64(&memcg
->memsw
, RES_USAGE
);
5115 * Transparent hugepages are still accounted for in MEM_CGROUP_STAT_RSS
5116 * as well as in MEM_CGROUP_STAT_RSS_HUGE.
5118 val
= mem_cgroup_recursive_stat(memcg
, MEM_CGROUP_STAT_CACHE
);
5119 val
+= mem_cgroup_recursive_stat(memcg
, MEM_CGROUP_STAT_RSS
);
5122 val
+= mem_cgroup_recursive_stat(memcg
, MEM_CGROUP_STAT_SWAP
);
5124 return val
<< PAGE_SHIFT
;
5127 static ssize_t
mem_cgroup_read(struct cgroup
*cont
, struct cftype
*cft
,
5128 struct file
*file
, char __user
*buf
,
5129 size_t nbytes
, loff_t
*ppos
)
5131 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cont
);
5137 type
= MEMFILE_TYPE(cft
->private);
5138 name
= MEMFILE_ATTR(cft
->private);
5142 if (name
== RES_USAGE
)
5143 val
= mem_cgroup_usage(memcg
, false);
5145 val
= res_counter_read_u64(&memcg
->res
, name
);
5148 if (name
== RES_USAGE
)
5149 val
= mem_cgroup_usage(memcg
, true);
5151 val
= res_counter_read_u64(&memcg
->memsw
, name
);
5154 val
= res_counter_read_u64(&memcg
->kmem
, name
);
5160 len
= scnprintf(str
, sizeof(str
), "%llu\n", (unsigned long long)val
);
5161 return simple_read_from_buffer(buf
, nbytes
, ppos
, str
, len
);
5164 static int memcg_update_kmem_limit(struct cgroup
*cont
, u64 val
)
5167 #ifdef CONFIG_MEMCG_KMEM
5168 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cont
);
5170 * For simplicity, we won't allow this to be disabled. It also can't
5171 * be changed if the cgroup has children already, or if tasks had
5174 * If tasks join before we set the limit, a person looking at
5175 * kmem.usage_in_bytes will have no way to determine when it took
5176 * place, which makes the value quite meaningless.
5178 * After it first became limited, changes in the value of the limit are
5179 * of course permitted.
5181 mutex_lock(&memcg_create_mutex
);
5182 mutex_lock(&set_limit_mutex
);
5183 if (!memcg
->kmem_account_flags
&& val
!= RESOURCE_MAX
) {
5184 if (cgroup_task_count(cont
) || memcg_has_children(memcg
)) {
5188 ret
= res_counter_set_limit(&memcg
->kmem
, val
);
5191 ret
= memcg_update_cache_sizes(memcg
);
5193 res_counter_set_limit(&memcg
->kmem
, RESOURCE_MAX
);
5196 static_key_slow_inc(&memcg_kmem_enabled_key
);
5198 * setting the active bit after the inc will guarantee no one
5199 * starts accounting before all call sites are patched
5201 memcg_kmem_set_active(memcg
);
5203 ret
= res_counter_set_limit(&memcg
->kmem
, val
);
5205 mutex_unlock(&set_limit_mutex
);
5206 mutex_unlock(&memcg_create_mutex
);
5211 #ifdef CONFIG_MEMCG_KMEM
5212 static int memcg_propagate_kmem(struct mem_cgroup
*memcg
)
5215 struct mem_cgroup
*parent
= parent_mem_cgroup(memcg
);
5219 memcg
->kmem_account_flags
= parent
->kmem_account_flags
;
5221 * When that happen, we need to disable the static branch only on those
5222 * memcgs that enabled it. To achieve this, we would be forced to
5223 * complicate the code by keeping track of which memcgs were the ones
5224 * that actually enabled limits, and which ones got it from its
5227 * It is a lot simpler just to do static_key_slow_inc() on every child
5228 * that is accounted.
5230 if (!memcg_kmem_is_active(memcg
))
5234 * __mem_cgroup_free() will issue static_key_slow_dec() because this
5235 * memcg is active already. If the later initialization fails then the
5236 * cgroup core triggers the cleanup so we do not have to do it here.
5238 static_key_slow_inc(&memcg_kmem_enabled_key
);
5240 mutex_lock(&set_limit_mutex
);
5241 memcg_stop_kmem_account();
5242 ret
= memcg_update_cache_sizes(memcg
);
5243 memcg_resume_kmem_account();
5244 mutex_unlock(&set_limit_mutex
);
5248 #endif /* CONFIG_MEMCG_KMEM */
5251 * The user of this function is...
5254 static int mem_cgroup_write(struct cgroup
*cont
, struct cftype
*cft
,
5257 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cont
);
5260 unsigned long long val
;
5263 type
= MEMFILE_TYPE(cft
->private);
5264 name
= MEMFILE_ATTR(cft
->private);
5268 if (mem_cgroup_is_root(memcg
)) { /* Can't set limit on root */
5272 /* This function does all necessary parse...reuse it */
5273 ret
= res_counter_memparse_write_strategy(buffer
, &val
);
5277 ret
= mem_cgroup_resize_limit(memcg
, val
);
5278 else if (type
== _MEMSWAP
)
5279 ret
= mem_cgroup_resize_memsw_limit(memcg
, val
);
5280 else if (type
== _KMEM
)
5281 ret
= memcg_update_kmem_limit(cont
, val
);
5285 case RES_SOFT_LIMIT
:
5286 ret
= res_counter_memparse_write_strategy(buffer
, &val
);
5290 * For memsw, soft limits are hard to implement in terms
5291 * of semantics, for now, we support soft limits for
5292 * control without swap
5295 ret
= res_counter_set_soft_limit(&memcg
->res
, val
);
5300 ret
= -EINVAL
; /* should be BUG() ? */
5306 static void memcg_get_hierarchical_limit(struct mem_cgroup
*memcg
,
5307 unsigned long long *mem_limit
, unsigned long long *memsw_limit
)
5309 struct cgroup
*cgroup
;
5310 unsigned long long min_limit
, min_memsw_limit
, tmp
;
5312 min_limit
= res_counter_read_u64(&memcg
->res
, RES_LIMIT
);
5313 min_memsw_limit
= res_counter_read_u64(&memcg
->memsw
, RES_LIMIT
);
5314 cgroup
= memcg
->css
.cgroup
;
5315 if (!memcg
->use_hierarchy
)
5318 while (cgroup
->parent
) {
5319 cgroup
= cgroup
->parent
;
5320 memcg
= mem_cgroup_from_cont(cgroup
);
5321 if (!memcg
->use_hierarchy
)
5323 tmp
= res_counter_read_u64(&memcg
->res
, RES_LIMIT
);
5324 min_limit
= min(min_limit
, tmp
);
5325 tmp
= res_counter_read_u64(&memcg
->memsw
, RES_LIMIT
);
5326 min_memsw_limit
= min(min_memsw_limit
, tmp
);
5329 *mem_limit
= min_limit
;
5330 *memsw_limit
= min_memsw_limit
;
5333 static int mem_cgroup_reset(struct cgroup
*cont
, unsigned int event
)
5335 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cont
);
5339 type
= MEMFILE_TYPE(event
);
5340 name
= MEMFILE_ATTR(event
);
5345 res_counter_reset_max(&memcg
->res
);
5346 else if (type
== _MEMSWAP
)
5347 res_counter_reset_max(&memcg
->memsw
);
5348 else if (type
== _KMEM
)
5349 res_counter_reset_max(&memcg
->kmem
);
5355 res_counter_reset_failcnt(&memcg
->res
);
5356 else if (type
== _MEMSWAP
)
5357 res_counter_reset_failcnt(&memcg
->memsw
);
5358 else if (type
== _KMEM
)
5359 res_counter_reset_failcnt(&memcg
->kmem
);
5368 static u64
mem_cgroup_move_charge_read(struct cgroup
*cgrp
,
5371 return mem_cgroup_from_cont(cgrp
)->move_charge_at_immigrate
;
5375 static int mem_cgroup_move_charge_write(struct cgroup
*cgrp
,
5376 struct cftype
*cft
, u64 val
)
5378 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cgrp
);
5380 if (val
>= (1 << NR_MOVE_TYPE
))
5384 * No kind of locking is needed in here, because ->can_attach() will
5385 * check this value once in the beginning of the process, and then carry
5386 * on with stale data. This means that changes to this value will only
5387 * affect task migrations starting after the change.
5389 memcg
->move_charge_at_immigrate
= val
;
5393 static int mem_cgroup_move_charge_write(struct cgroup
*cgrp
,
5394 struct cftype
*cft
, u64 val
)
5401 static int memcg_numa_stat_show(struct cgroup
*cont
, struct cftype
*cft
,
5405 unsigned long total_nr
, file_nr
, anon_nr
, unevictable_nr
;
5406 unsigned long node_nr
;
5407 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cont
);
5409 total_nr
= mem_cgroup_nr_lru_pages(memcg
, LRU_ALL
);
5410 seq_printf(m
, "total=%lu", total_nr
);
5411 for_each_node_state(nid
, N_MEMORY
) {
5412 node_nr
= mem_cgroup_node_nr_lru_pages(memcg
, nid
, LRU_ALL
);
5413 seq_printf(m
, " N%d=%lu", nid
, node_nr
);
5417 file_nr
= mem_cgroup_nr_lru_pages(memcg
, LRU_ALL_FILE
);
5418 seq_printf(m
, "file=%lu", file_nr
);
5419 for_each_node_state(nid
, N_MEMORY
) {
5420 node_nr
= mem_cgroup_node_nr_lru_pages(memcg
, nid
,
5422 seq_printf(m
, " N%d=%lu", nid
, node_nr
);
5426 anon_nr
= mem_cgroup_nr_lru_pages(memcg
, LRU_ALL_ANON
);
5427 seq_printf(m
, "anon=%lu", anon_nr
);
5428 for_each_node_state(nid
, N_MEMORY
) {
5429 node_nr
= mem_cgroup_node_nr_lru_pages(memcg
, nid
,
5431 seq_printf(m
, " N%d=%lu", nid
, node_nr
);
5435 unevictable_nr
= mem_cgroup_nr_lru_pages(memcg
, BIT(LRU_UNEVICTABLE
));
5436 seq_printf(m
, "unevictable=%lu", unevictable_nr
);
5437 for_each_node_state(nid
, N_MEMORY
) {
5438 node_nr
= mem_cgroup_node_nr_lru_pages(memcg
, nid
,
5439 BIT(LRU_UNEVICTABLE
));
5440 seq_printf(m
, " N%d=%lu", nid
, node_nr
);
5445 #endif /* CONFIG_NUMA */
5447 static inline void mem_cgroup_lru_names_not_uptodate(void)
5449 BUILD_BUG_ON(ARRAY_SIZE(mem_cgroup_lru_names
) != NR_LRU_LISTS
);
5452 static int memcg_stat_show(struct cgroup
*cont
, struct cftype
*cft
,
5455 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cont
);
5456 struct mem_cgroup
*mi
;
5459 for (i
= 0; i
< MEM_CGROUP_STAT_NSTATS
; i
++) {
5460 if (i
== MEM_CGROUP_STAT_SWAP
&& !do_swap_account
)
5462 seq_printf(m
, "%s %ld\n", mem_cgroup_stat_names
[i
],
5463 mem_cgroup_read_stat(memcg
, i
) * PAGE_SIZE
);
5466 for (i
= 0; i
< MEM_CGROUP_EVENTS_NSTATS
; i
++)
5467 seq_printf(m
, "%s %lu\n", mem_cgroup_events_names
[i
],
5468 mem_cgroup_read_events(memcg
, i
));
5470 for (i
= 0; i
< NR_LRU_LISTS
; i
++)
5471 seq_printf(m
, "%s %lu\n", mem_cgroup_lru_names
[i
],
5472 mem_cgroup_nr_lru_pages(memcg
, BIT(i
)) * PAGE_SIZE
);
5474 /* Hierarchical information */
5476 unsigned long long limit
, memsw_limit
;
5477 memcg_get_hierarchical_limit(memcg
, &limit
, &memsw_limit
);
5478 seq_printf(m
, "hierarchical_memory_limit %llu\n", limit
);
5479 if (do_swap_account
)
5480 seq_printf(m
, "hierarchical_memsw_limit %llu\n",
5484 for (i
= 0; i
< MEM_CGROUP_STAT_NSTATS
; i
++) {
5487 if (i
== MEM_CGROUP_STAT_SWAP
&& !do_swap_account
)
5489 for_each_mem_cgroup_tree(mi
, memcg
)
5490 val
+= mem_cgroup_read_stat(mi
, i
) * PAGE_SIZE
;
5491 seq_printf(m
, "total_%s %lld\n", mem_cgroup_stat_names
[i
], val
);
5494 for (i
= 0; i
< MEM_CGROUP_EVENTS_NSTATS
; i
++) {
5495 unsigned long long val
= 0;
5497 for_each_mem_cgroup_tree(mi
, memcg
)
5498 val
+= mem_cgroup_read_events(mi
, i
);
5499 seq_printf(m
, "total_%s %llu\n",
5500 mem_cgroup_events_names
[i
], val
);
5503 for (i
= 0; i
< NR_LRU_LISTS
; i
++) {
5504 unsigned long long val
= 0;
5506 for_each_mem_cgroup_tree(mi
, memcg
)
5507 val
+= mem_cgroup_nr_lru_pages(mi
, BIT(i
)) * PAGE_SIZE
;
5508 seq_printf(m
, "total_%s %llu\n", mem_cgroup_lru_names
[i
], val
);
5511 #ifdef CONFIG_DEBUG_VM
5514 struct mem_cgroup_per_zone
*mz
;
5515 struct zone_reclaim_stat
*rstat
;
5516 unsigned long recent_rotated
[2] = {0, 0};
5517 unsigned long recent_scanned
[2] = {0, 0};
5519 for_each_online_node(nid
)
5520 for (zid
= 0; zid
< MAX_NR_ZONES
; zid
++) {
5521 mz
= mem_cgroup_zoneinfo(memcg
, nid
, zid
);
5522 rstat
= &mz
->lruvec
.reclaim_stat
;
5524 recent_rotated
[0] += rstat
->recent_rotated
[0];
5525 recent_rotated
[1] += rstat
->recent_rotated
[1];
5526 recent_scanned
[0] += rstat
->recent_scanned
[0];
5527 recent_scanned
[1] += rstat
->recent_scanned
[1];
5529 seq_printf(m
, "recent_rotated_anon %lu\n", recent_rotated
[0]);
5530 seq_printf(m
, "recent_rotated_file %lu\n", recent_rotated
[1]);
5531 seq_printf(m
, "recent_scanned_anon %lu\n", recent_scanned
[0]);
5532 seq_printf(m
, "recent_scanned_file %lu\n", recent_scanned
[1]);
5539 static u64
mem_cgroup_swappiness_read(struct cgroup
*cgrp
, struct cftype
*cft
)
5541 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cgrp
);
5543 return mem_cgroup_swappiness(memcg
);
5546 static int mem_cgroup_swappiness_write(struct cgroup
*cgrp
, struct cftype
*cft
,
5549 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cgrp
);
5550 struct mem_cgroup
*parent
;
5555 if (cgrp
->parent
== NULL
)
5558 parent
= mem_cgroup_from_cont(cgrp
->parent
);
5560 mutex_lock(&memcg_create_mutex
);
5562 /* If under hierarchy, only empty-root can set this value */
5563 if ((parent
->use_hierarchy
) || memcg_has_children(memcg
)) {
5564 mutex_unlock(&memcg_create_mutex
);
5568 memcg
->swappiness
= val
;
5570 mutex_unlock(&memcg_create_mutex
);
5575 static void __mem_cgroup_threshold(struct mem_cgroup
*memcg
, bool swap
)
5577 struct mem_cgroup_threshold_ary
*t
;
5583 t
= rcu_dereference(memcg
->thresholds
.primary
);
5585 t
= rcu_dereference(memcg
->memsw_thresholds
.primary
);
5590 usage
= mem_cgroup_usage(memcg
, swap
);
5593 * current_threshold points to threshold just below or equal to usage.
5594 * If it's not true, a threshold was crossed after last
5595 * call of __mem_cgroup_threshold().
5597 i
= t
->current_threshold
;
5600 * Iterate backward over array of thresholds starting from
5601 * current_threshold and check if a threshold is crossed.
5602 * If none of thresholds below usage is crossed, we read
5603 * only one element of the array here.
5605 for (; i
>= 0 && unlikely(t
->entries
[i
].threshold
> usage
); i
--)
5606 eventfd_signal(t
->entries
[i
].eventfd
, 1);
5608 /* i = current_threshold + 1 */
5612 * Iterate forward over array of thresholds starting from
5613 * current_threshold+1 and check if a threshold is crossed.
5614 * If none of thresholds above usage is crossed, we read
5615 * only one element of the array here.
5617 for (; i
< t
->size
&& unlikely(t
->entries
[i
].threshold
<= usage
); i
++)
5618 eventfd_signal(t
->entries
[i
].eventfd
, 1);
5620 /* Update current_threshold */
5621 t
->current_threshold
= i
- 1;
5626 static void mem_cgroup_threshold(struct mem_cgroup
*memcg
)
5629 __mem_cgroup_threshold(memcg
, false);
5630 if (do_swap_account
)
5631 __mem_cgroup_threshold(memcg
, true);
5633 memcg
= parent_mem_cgroup(memcg
);
5637 static int compare_thresholds(const void *a
, const void *b
)
5639 const struct mem_cgroup_threshold
*_a
= a
;
5640 const struct mem_cgroup_threshold
*_b
= b
;
5642 return _a
->threshold
- _b
->threshold
;
5645 static int mem_cgroup_oom_notify_cb(struct mem_cgroup
*memcg
)
5647 struct mem_cgroup_eventfd_list
*ev
;
5649 list_for_each_entry(ev
, &memcg
->oom_notify
, list
)
5650 eventfd_signal(ev
->eventfd
, 1);
5654 static void mem_cgroup_oom_notify(struct mem_cgroup
*memcg
)
5656 struct mem_cgroup
*iter
;
5658 for_each_mem_cgroup_tree(iter
, memcg
)
5659 mem_cgroup_oom_notify_cb(iter
);
5662 static int mem_cgroup_usage_register_event(struct cgroup
*cgrp
,
5663 struct cftype
*cft
, struct eventfd_ctx
*eventfd
, const char *args
)
5665 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cgrp
);
5666 struct mem_cgroup_thresholds
*thresholds
;
5667 struct mem_cgroup_threshold_ary
*new;
5668 enum res_type type
= MEMFILE_TYPE(cft
->private);
5669 u64 threshold
, usage
;
5672 ret
= res_counter_memparse_write_strategy(args
, &threshold
);
5676 mutex_lock(&memcg
->thresholds_lock
);
5679 thresholds
= &memcg
->thresholds
;
5680 else if (type
== _MEMSWAP
)
5681 thresholds
= &memcg
->memsw_thresholds
;
5685 usage
= mem_cgroup_usage(memcg
, type
== _MEMSWAP
);
5687 /* Check if a threshold crossed before adding a new one */
5688 if (thresholds
->primary
)
5689 __mem_cgroup_threshold(memcg
, type
== _MEMSWAP
);
5691 size
= thresholds
->primary
? thresholds
->primary
->size
+ 1 : 1;
5693 /* Allocate memory for new array of thresholds */
5694 new = kmalloc(sizeof(*new) + size
* sizeof(struct mem_cgroup_threshold
),
5702 /* Copy thresholds (if any) to new array */
5703 if (thresholds
->primary
) {
5704 memcpy(new->entries
, thresholds
->primary
->entries
, (size
- 1) *
5705 sizeof(struct mem_cgroup_threshold
));
5708 /* Add new threshold */
5709 new->entries
[size
- 1].eventfd
= eventfd
;
5710 new->entries
[size
- 1].threshold
= threshold
;
5712 /* Sort thresholds. Registering of new threshold isn't time-critical */
5713 sort(new->entries
, size
, sizeof(struct mem_cgroup_threshold
),
5714 compare_thresholds
, NULL
);
5716 /* Find current threshold */
5717 new->current_threshold
= -1;
5718 for (i
= 0; i
< size
; i
++) {
5719 if (new->entries
[i
].threshold
<= usage
) {
5721 * new->current_threshold will not be used until
5722 * rcu_assign_pointer(), so it's safe to increment
5725 ++new->current_threshold
;
5730 /* Free old spare buffer and save old primary buffer as spare */
5731 kfree(thresholds
->spare
);
5732 thresholds
->spare
= thresholds
->primary
;
5734 rcu_assign_pointer(thresholds
->primary
, new);
5736 /* To be sure that nobody uses thresholds */
5740 mutex_unlock(&memcg
->thresholds_lock
);
5745 static void mem_cgroup_usage_unregister_event(struct cgroup
*cgrp
,
5746 struct cftype
*cft
, struct eventfd_ctx
*eventfd
)
5748 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cgrp
);
5749 struct mem_cgroup_thresholds
*thresholds
;
5750 struct mem_cgroup_threshold_ary
*new;
5751 enum res_type type
= MEMFILE_TYPE(cft
->private);
5755 mutex_lock(&memcg
->thresholds_lock
);
5757 thresholds
= &memcg
->thresholds
;
5758 else if (type
== _MEMSWAP
)
5759 thresholds
= &memcg
->memsw_thresholds
;
5763 if (!thresholds
->primary
)
5766 usage
= mem_cgroup_usage(memcg
, type
== _MEMSWAP
);
5768 /* Check if a threshold crossed before removing */
5769 __mem_cgroup_threshold(memcg
, type
== _MEMSWAP
);
5771 /* Calculate new number of threshold */
5773 for (i
= 0; i
< thresholds
->primary
->size
; i
++) {
5774 if (thresholds
->primary
->entries
[i
].eventfd
!= eventfd
)
5778 new = thresholds
->spare
;
5780 /* Set thresholds array to NULL if we don't have thresholds */
5789 /* Copy thresholds and find current threshold */
5790 new->current_threshold
= -1;
5791 for (i
= 0, j
= 0; i
< thresholds
->primary
->size
; i
++) {
5792 if (thresholds
->primary
->entries
[i
].eventfd
== eventfd
)
5795 new->entries
[j
] = thresholds
->primary
->entries
[i
];
5796 if (new->entries
[j
].threshold
<= usage
) {
5798 * new->current_threshold will not be used
5799 * until rcu_assign_pointer(), so it's safe to increment
5802 ++new->current_threshold
;
5808 /* Swap primary and spare array */
5809 thresholds
->spare
= thresholds
->primary
;
5810 /* If all events are unregistered, free the spare array */
5812 kfree(thresholds
->spare
);
5813 thresholds
->spare
= NULL
;
5816 rcu_assign_pointer(thresholds
->primary
, new);
5818 /* To be sure that nobody uses thresholds */
5821 mutex_unlock(&memcg
->thresholds_lock
);
5824 static int mem_cgroup_oom_register_event(struct cgroup
*cgrp
,
5825 struct cftype
*cft
, struct eventfd_ctx
*eventfd
, const char *args
)
5827 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cgrp
);
5828 struct mem_cgroup_eventfd_list
*event
;
5829 enum res_type type
= MEMFILE_TYPE(cft
->private);
5831 BUG_ON(type
!= _OOM_TYPE
);
5832 event
= kmalloc(sizeof(*event
), GFP_KERNEL
);
5836 spin_lock(&memcg_oom_lock
);
5838 event
->eventfd
= eventfd
;
5839 list_add(&event
->list
, &memcg
->oom_notify
);
5841 /* already in OOM ? */
5842 if (atomic_read(&memcg
->under_oom
))
5843 eventfd_signal(eventfd
, 1);
5844 spin_unlock(&memcg_oom_lock
);
5849 static void mem_cgroup_oom_unregister_event(struct cgroup
*cgrp
,
5850 struct cftype
*cft
, struct eventfd_ctx
*eventfd
)
5852 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cgrp
);
5853 struct mem_cgroup_eventfd_list
*ev
, *tmp
;
5854 enum res_type type
= MEMFILE_TYPE(cft
->private);
5856 BUG_ON(type
!= _OOM_TYPE
);
5858 spin_lock(&memcg_oom_lock
);
5860 list_for_each_entry_safe(ev
, tmp
, &memcg
->oom_notify
, list
) {
5861 if (ev
->eventfd
== eventfd
) {
5862 list_del(&ev
->list
);
5867 spin_unlock(&memcg_oom_lock
);
5870 static int mem_cgroup_oom_control_read(struct cgroup
*cgrp
,
5871 struct cftype
*cft
, struct cgroup_map_cb
*cb
)
5873 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cgrp
);
5875 cb
->fill(cb
, "oom_kill_disable", memcg
->oom_kill_disable
);
5877 if (atomic_read(&memcg
->under_oom
))
5878 cb
->fill(cb
, "under_oom", 1);
5880 cb
->fill(cb
, "under_oom", 0);
5884 static int mem_cgroup_oom_control_write(struct cgroup
*cgrp
,
5885 struct cftype
*cft
, u64 val
)
5887 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cgrp
);
5888 struct mem_cgroup
*parent
;
5890 /* cannot set to root cgroup and only 0 and 1 are allowed */
5891 if (!cgrp
->parent
|| !((val
== 0) || (val
== 1)))
5894 parent
= mem_cgroup_from_cont(cgrp
->parent
);
5896 mutex_lock(&memcg_create_mutex
);
5897 /* oom-kill-disable is a flag for subhierarchy. */
5898 if ((parent
->use_hierarchy
) || memcg_has_children(memcg
)) {
5899 mutex_unlock(&memcg_create_mutex
);
5902 memcg
->oom_kill_disable
= val
;
5904 memcg_oom_recover(memcg
);
5905 mutex_unlock(&memcg_create_mutex
);
5909 #ifdef CONFIG_MEMCG_KMEM
5910 static int memcg_init_kmem(struct mem_cgroup
*memcg
, struct cgroup_subsys
*ss
)
5914 memcg
->kmemcg_id
= -1;
5915 ret
= memcg_propagate_kmem(memcg
);
5919 return mem_cgroup_sockets_init(memcg
, ss
);
5922 static void memcg_destroy_kmem(struct mem_cgroup
*memcg
)
5924 mem_cgroup_sockets_destroy(memcg
);
5927 static void kmem_cgroup_css_offline(struct mem_cgroup
*memcg
)
5929 if (!memcg_kmem_is_active(memcg
))
5933 * kmem charges can outlive the cgroup. In the case of slab
5934 * pages, for instance, a page contain objects from various
5935 * processes. As we prevent from taking a reference for every
5936 * such allocation we have to be careful when doing uncharge
5937 * (see memcg_uncharge_kmem) and here during offlining.
5939 * The idea is that that only the _last_ uncharge which sees
5940 * the dead memcg will drop the last reference. An additional
5941 * reference is taken here before the group is marked dead
5942 * which is then paired with css_put during uncharge resp. here.
5944 * Although this might sound strange as this path is called from
5945 * css_offline() when the referencemight have dropped down to 0
5946 * and shouldn't be incremented anymore (css_tryget would fail)
5947 * we do not have other options because of the kmem allocations
5950 css_get(&memcg
->css
);
5952 memcg_kmem_mark_dead(memcg
);
5954 if (res_counter_read_u64(&memcg
->kmem
, RES_USAGE
) != 0)
5957 if (memcg_kmem_test_and_clear_dead(memcg
))
5958 css_put(&memcg
->css
);
5961 static int memcg_init_kmem(struct mem_cgroup
*memcg
, struct cgroup_subsys
*ss
)
5966 static void memcg_destroy_kmem(struct mem_cgroup
*memcg
)
5970 static void kmem_cgroup_css_offline(struct mem_cgroup
*memcg
)
5975 static struct cftype mem_cgroup_files
[] = {
5977 .name
= "usage_in_bytes",
5978 .private = MEMFILE_PRIVATE(_MEM
, RES_USAGE
),
5979 .read
= mem_cgroup_read
,
5980 .register_event
= mem_cgroup_usage_register_event
,
5981 .unregister_event
= mem_cgroup_usage_unregister_event
,
5984 .name
= "max_usage_in_bytes",
5985 .private = MEMFILE_PRIVATE(_MEM
, RES_MAX_USAGE
),
5986 .trigger
= mem_cgroup_reset
,
5987 .read
= mem_cgroup_read
,
5990 .name
= "limit_in_bytes",
5991 .private = MEMFILE_PRIVATE(_MEM
, RES_LIMIT
),
5992 .write_string
= mem_cgroup_write
,
5993 .read
= mem_cgroup_read
,
5996 .name
= "soft_limit_in_bytes",
5997 .private = MEMFILE_PRIVATE(_MEM
, RES_SOFT_LIMIT
),
5998 .write_string
= mem_cgroup_write
,
5999 .read
= mem_cgroup_read
,
6003 .private = MEMFILE_PRIVATE(_MEM
, RES_FAILCNT
),
6004 .trigger
= mem_cgroup_reset
,
6005 .read
= mem_cgroup_read
,
6009 .read_seq_string
= memcg_stat_show
,
6012 .name
= "force_empty",
6013 .trigger
= mem_cgroup_force_empty_write
,
6016 .name
= "use_hierarchy",
6017 .flags
= CFTYPE_INSANE
,
6018 .write_u64
= mem_cgroup_hierarchy_write
,
6019 .read_u64
= mem_cgroup_hierarchy_read
,
6022 .name
= "swappiness",
6023 .read_u64
= mem_cgroup_swappiness_read
,
6024 .write_u64
= mem_cgroup_swappiness_write
,
6027 .name
= "move_charge_at_immigrate",
6028 .read_u64
= mem_cgroup_move_charge_read
,
6029 .write_u64
= mem_cgroup_move_charge_write
,
6032 .name
= "oom_control",
6033 .read_map
= mem_cgroup_oom_control_read
,
6034 .write_u64
= mem_cgroup_oom_control_write
,
6035 .register_event
= mem_cgroup_oom_register_event
,
6036 .unregister_event
= mem_cgroup_oom_unregister_event
,
6037 .private = MEMFILE_PRIVATE(_OOM_TYPE
, OOM_CONTROL
),
6040 .name
= "pressure_level",
6041 .register_event
= vmpressure_register_event
,
6042 .unregister_event
= vmpressure_unregister_event
,
6046 .name
= "numa_stat",
6047 .read_seq_string
= memcg_numa_stat_show
,
6050 #ifdef CONFIG_MEMCG_KMEM
6052 .name
= "kmem.limit_in_bytes",
6053 .private = MEMFILE_PRIVATE(_KMEM
, RES_LIMIT
),
6054 .write_string
= mem_cgroup_write
,
6055 .read
= mem_cgroup_read
,
6058 .name
= "kmem.usage_in_bytes",
6059 .private = MEMFILE_PRIVATE(_KMEM
, RES_USAGE
),
6060 .read
= mem_cgroup_read
,
6063 .name
= "kmem.failcnt",
6064 .private = MEMFILE_PRIVATE(_KMEM
, RES_FAILCNT
),
6065 .trigger
= mem_cgroup_reset
,
6066 .read
= mem_cgroup_read
,
6069 .name
= "kmem.max_usage_in_bytes",
6070 .private = MEMFILE_PRIVATE(_KMEM
, RES_MAX_USAGE
),
6071 .trigger
= mem_cgroup_reset
,
6072 .read
= mem_cgroup_read
,
6074 #ifdef CONFIG_SLABINFO
6076 .name
= "kmem.slabinfo",
6077 .read_seq_string
= mem_cgroup_slabinfo_read
,
6081 { }, /* terminate */
6084 #ifdef CONFIG_MEMCG_SWAP
6085 static struct cftype memsw_cgroup_files
[] = {
6087 .name
= "memsw.usage_in_bytes",
6088 .private = MEMFILE_PRIVATE(_MEMSWAP
, RES_USAGE
),
6089 .read
= mem_cgroup_read
,
6090 .register_event
= mem_cgroup_usage_register_event
,
6091 .unregister_event
= mem_cgroup_usage_unregister_event
,
6094 .name
= "memsw.max_usage_in_bytes",
6095 .private = MEMFILE_PRIVATE(_MEMSWAP
, RES_MAX_USAGE
),
6096 .trigger
= mem_cgroup_reset
,
6097 .read
= mem_cgroup_read
,
6100 .name
= "memsw.limit_in_bytes",
6101 .private = MEMFILE_PRIVATE(_MEMSWAP
, RES_LIMIT
),
6102 .write_string
= mem_cgroup_write
,
6103 .read
= mem_cgroup_read
,
6106 .name
= "memsw.failcnt",
6107 .private = MEMFILE_PRIVATE(_MEMSWAP
, RES_FAILCNT
),
6108 .trigger
= mem_cgroup_reset
,
6109 .read
= mem_cgroup_read
,
6111 { }, /* terminate */
6114 static int alloc_mem_cgroup_per_zone_info(struct mem_cgroup
*memcg
, int node
)
6116 struct mem_cgroup_per_node
*pn
;
6117 struct mem_cgroup_per_zone
*mz
;
6118 int zone
, tmp
= node
;
6120 * This routine is called against possible nodes.
6121 * But it's BUG to call kmalloc() against offline node.
6123 * TODO: this routine can waste much memory for nodes which will
6124 * never be onlined. It's better to use memory hotplug callback
6127 if (!node_state(node
, N_NORMAL_MEMORY
))
6129 pn
= kzalloc_node(sizeof(*pn
), GFP_KERNEL
, tmp
);
6133 for (zone
= 0; zone
< MAX_NR_ZONES
; zone
++) {
6134 mz
= &pn
->zoneinfo
[zone
];
6135 lruvec_init(&mz
->lruvec
);
6136 mz
->usage_in_excess
= 0;
6137 mz
->on_tree
= false;
6140 memcg
->nodeinfo
[node
] = pn
;
6144 static void free_mem_cgroup_per_zone_info(struct mem_cgroup
*memcg
, int node
)
6146 kfree(memcg
->nodeinfo
[node
]);
6149 static struct mem_cgroup
*mem_cgroup_alloc(void)
6151 struct mem_cgroup
*memcg
;
6152 size_t size
= memcg_size();
6154 /* Can be very big if nr_node_ids is very big */
6155 if (size
< PAGE_SIZE
)
6156 memcg
= kzalloc(size
, GFP_KERNEL
);
6158 memcg
= vzalloc(size
);
6163 memcg
->stat
= alloc_percpu(struct mem_cgroup_stat_cpu
);
6166 spin_lock_init(&memcg
->pcp_counter_lock
);
6170 if (size
< PAGE_SIZE
)
6178 * At destroying mem_cgroup, references from swap_cgroup can remain.
6179 * (scanning all at force_empty is too costly...)
6181 * Instead of clearing all references at force_empty, we remember
6182 * the number of reference from swap_cgroup and free mem_cgroup when
6183 * it goes down to 0.
6185 * Removal of cgroup itself succeeds regardless of refs from swap.
6188 static void __mem_cgroup_free(struct mem_cgroup
*memcg
)
6191 size_t size
= memcg_size();
6193 mem_cgroup_remove_from_trees(memcg
);
6194 free_css_id(&mem_cgroup_subsys
, &memcg
->css
);
6197 free_mem_cgroup_per_zone_info(memcg
, node
);
6199 free_percpu(memcg
->stat
);
6202 * We need to make sure that (at least for now), the jump label
6203 * destruction code runs outside of the cgroup lock. This is because
6204 * get_online_cpus(), which is called from the static_branch update,
6205 * can't be called inside the cgroup_lock. cpusets are the ones
6206 * enforcing this dependency, so if they ever change, we might as well.
6208 * schedule_work() will guarantee this happens. Be careful if you need
6209 * to move this code around, and make sure it is outside
6212 disarm_static_keys(memcg
);
6213 if (size
< PAGE_SIZE
)
6221 * Helpers for freeing a kmalloc()ed/vzalloc()ed mem_cgroup by RCU,
6222 * but in process context. The work_freeing structure is overlaid
6223 * on the rcu_freeing structure, which itself is overlaid on memsw.
6225 static void free_work(struct work_struct
*work
)
6227 struct mem_cgroup
*memcg
;
6229 memcg
= container_of(work
, struct mem_cgroup
, work_freeing
);
6230 __mem_cgroup_free(memcg
);
6233 static void free_rcu(struct rcu_head
*rcu_head
)
6235 struct mem_cgroup
*memcg
;
6237 memcg
= container_of(rcu_head
, struct mem_cgroup
, rcu_freeing
);
6238 INIT_WORK(&memcg
->work_freeing
, free_work
);
6239 schedule_work(&memcg
->work_freeing
);
6242 static void mem_cgroup_get(struct mem_cgroup
*memcg
)
6244 atomic_inc(&memcg
->refcnt
);
6247 static void __mem_cgroup_put(struct mem_cgroup
*memcg
, int count
)
6249 if (atomic_sub_and_test(count
, &memcg
->refcnt
)) {
6250 struct mem_cgroup
*parent
= parent_mem_cgroup(memcg
);
6251 call_rcu(&memcg
->rcu_freeing
, free_rcu
);
6253 mem_cgroup_put(parent
);
6257 static void mem_cgroup_put(struct mem_cgroup
*memcg
)
6259 __mem_cgroup_put(memcg
, 1);
6263 * Returns the parent mem_cgroup in memcgroup hierarchy with hierarchy enabled.
6265 struct mem_cgroup
*parent_mem_cgroup(struct mem_cgroup
*memcg
)
6267 if (!memcg
->res
.parent
)
6269 return mem_cgroup_from_res_counter(memcg
->res
.parent
, res
);
6271 EXPORT_SYMBOL(parent_mem_cgroup
);
6273 static void __init
mem_cgroup_soft_limit_tree_init(void)
6275 struct mem_cgroup_tree_per_node
*rtpn
;
6276 struct mem_cgroup_tree_per_zone
*rtpz
;
6277 int tmp
, node
, zone
;
6279 for_each_node(node
) {
6281 if (!node_state(node
, N_NORMAL_MEMORY
))
6283 rtpn
= kzalloc_node(sizeof(*rtpn
), GFP_KERNEL
, tmp
);
6286 soft_limit_tree
.rb_tree_per_node
[node
] = rtpn
;
6288 for (zone
= 0; zone
< MAX_NR_ZONES
; zone
++) {
6289 rtpz
= &rtpn
->rb_tree_per_zone
[zone
];
6290 rtpz
->rb_root
= RB_ROOT
;
6291 spin_lock_init(&rtpz
->lock
);
6296 static struct cgroup_subsys_state
* __ref
6297 mem_cgroup_css_alloc(struct cgroup
*cont
)
6299 struct mem_cgroup
*memcg
;
6300 long error
= -ENOMEM
;
6303 memcg
= mem_cgroup_alloc();
6305 return ERR_PTR(error
);
6308 if (alloc_mem_cgroup_per_zone_info(memcg
, node
))
6312 if (cont
->parent
== NULL
) {
6313 root_mem_cgroup
= memcg
;
6314 res_counter_init(&memcg
->res
, NULL
);
6315 res_counter_init(&memcg
->memsw
, NULL
);
6316 res_counter_init(&memcg
->kmem
, NULL
);
6319 memcg
->last_scanned_node
= MAX_NUMNODES
;
6320 INIT_LIST_HEAD(&memcg
->oom_notify
);
6321 atomic_set(&memcg
->refcnt
, 1);
6322 memcg
->move_charge_at_immigrate
= 0;
6323 mutex_init(&memcg
->thresholds_lock
);
6324 spin_lock_init(&memcg
->move_lock
);
6325 vmpressure_init(&memcg
->vmpressure
);
6330 __mem_cgroup_free(memcg
);
6331 return ERR_PTR(error
);
6335 mem_cgroup_css_online(struct cgroup
*cont
)
6337 struct mem_cgroup
*memcg
, *parent
;
6343 mutex_lock(&memcg_create_mutex
);
6344 memcg
= mem_cgroup_from_cont(cont
);
6345 parent
= mem_cgroup_from_cont(cont
->parent
);
6347 memcg
->use_hierarchy
= parent
->use_hierarchy
;
6348 memcg
->oom_kill_disable
= parent
->oom_kill_disable
;
6349 memcg
->swappiness
= mem_cgroup_swappiness(parent
);
6351 if (parent
->use_hierarchy
) {
6352 res_counter_init(&memcg
->res
, &parent
->res
);
6353 res_counter_init(&memcg
->memsw
, &parent
->memsw
);
6354 res_counter_init(&memcg
->kmem
, &parent
->kmem
);
6357 * We increment refcnt of the parent to ensure that we can
6358 * safely access it on res_counter_charge/uncharge.
6359 * This refcnt will be decremented when freeing this
6360 * mem_cgroup(see mem_cgroup_put).
6362 mem_cgroup_get(parent
);
6364 res_counter_init(&memcg
->res
, NULL
);
6365 res_counter_init(&memcg
->memsw
, NULL
);
6366 res_counter_init(&memcg
->kmem
, NULL
);
6368 * Deeper hierachy with use_hierarchy == false doesn't make
6369 * much sense so let cgroup subsystem know about this
6370 * unfortunate state in our controller.
6372 if (parent
!= root_mem_cgroup
)
6373 mem_cgroup_subsys
.broken_hierarchy
= true;
6376 error
= memcg_init_kmem(memcg
, &mem_cgroup_subsys
);
6377 mutex_unlock(&memcg_create_mutex
);
6382 * Announce all parents that a group from their hierarchy is gone.
6384 static void mem_cgroup_invalidate_reclaim_iterators(struct mem_cgroup
*memcg
)
6386 struct mem_cgroup
*parent
= memcg
;
6388 while ((parent
= parent_mem_cgroup(parent
)))
6389 mem_cgroup_iter_invalidate(parent
);
6392 * if the root memcg is not hierarchical we have to check it
6395 if (!root_mem_cgroup
->use_hierarchy
)
6396 mem_cgroup_iter_invalidate(root_mem_cgroup
);
6399 static void mem_cgroup_css_offline(struct cgroup
*cont
)
6401 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cont
);
6403 kmem_cgroup_css_offline(memcg
);
6405 mem_cgroup_invalidate_reclaim_iterators(memcg
);
6406 mem_cgroup_reparent_charges(memcg
);
6407 mem_cgroup_destroy_all_caches(memcg
);
6410 static void mem_cgroup_css_free(struct cgroup
*cont
)
6412 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cont
);
6414 memcg_destroy_kmem(memcg
);
6415 __mem_cgroup_free(memcg
);
6419 /* Handlers for move charge at task migration. */
6420 #define PRECHARGE_COUNT_AT_ONCE 256
6421 static int mem_cgroup_do_precharge(unsigned long count
)
6424 int batch_count
= PRECHARGE_COUNT_AT_ONCE
;
6425 struct mem_cgroup
*memcg
= mc
.to
;
6427 if (mem_cgroup_is_root(memcg
)) {
6428 mc
.precharge
+= count
;
6429 /* we don't need css_get for root */
6432 /* try to charge at once */
6434 struct res_counter
*dummy
;
6436 * "memcg" cannot be under rmdir() because we've already checked
6437 * by cgroup_lock_live_cgroup() that it is not removed and we
6438 * are still under the same cgroup_mutex. So we can postpone
6441 if (res_counter_charge(&memcg
->res
, PAGE_SIZE
* count
, &dummy
))
6443 if (do_swap_account
&& res_counter_charge(&memcg
->memsw
,
6444 PAGE_SIZE
* count
, &dummy
)) {
6445 res_counter_uncharge(&memcg
->res
, PAGE_SIZE
* count
);
6448 mc
.precharge
+= count
;
6452 /* fall back to one by one charge */
6454 if (signal_pending(current
)) {
6458 if (!batch_count
--) {
6459 batch_count
= PRECHARGE_COUNT_AT_ONCE
;
6462 ret
= __mem_cgroup_try_charge(NULL
,
6463 GFP_KERNEL
, 1, &memcg
, false);
6465 /* mem_cgroup_clear_mc() will do uncharge later */
6473 * get_mctgt_type - get target type of moving charge
6474 * @vma: the vma the pte to be checked belongs
6475 * @addr: the address corresponding to the pte to be checked
6476 * @ptent: the pte to be checked
6477 * @target: the pointer the target page or swap ent will be stored(can be NULL)
6480 * 0(MC_TARGET_NONE): if the pte is not a target for move charge.
6481 * 1(MC_TARGET_PAGE): if the page corresponding to this pte is a target for
6482 * move charge. if @target is not NULL, the page is stored in target->page
6483 * with extra refcnt got(Callers should handle it).
6484 * 2(MC_TARGET_SWAP): if the swap entry corresponding to this pte is a
6485 * target for charge migration. if @target is not NULL, the entry is stored
6488 * Called with pte lock held.
6495 enum mc_target_type
{
6501 static struct page
*mc_handle_present_pte(struct vm_area_struct
*vma
,
6502 unsigned long addr
, pte_t ptent
)
6504 struct page
*page
= vm_normal_page(vma
, addr
, ptent
);
6506 if (!page
|| !page_mapped(page
))
6508 if (PageAnon(page
)) {
6509 /* we don't move shared anon */
6512 } else if (!move_file())
6513 /* we ignore mapcount for file pages */
6515 if (!get_page_unless_zero(page
))
6522 static struct page
*mc_handle_swap_pte(struct vm_area_struct
*vma
,
6523 unsigned long addr
, pte_t ptent
, swp_entry_t
*entry
)
6525 struct page
*page
= NULL
;
6526 swp_entry_t ent
= pte_to_swp_entry(ptent
);
6528 if (!move_anon() || non_swap_entry(ent
))
6531 * Because lookup_swap_cache() updates some statistics counter,
6532 * we call find_get_page() with swapper_space directly.
6534 page
= find_get_page(swap_address_space(ent
), ent
.val
);
6535 if (do_swap_account
)
6536 entry
->val
= ent
.val
;
6541 static struct page
*mc_handle_swap_pte(struct vm_area_struct
*vma
,
6542 unsigned long addr
, pte_t ptent
, swp_entry_t
*entry
)
6548 static struct page
*mc_handle_file_pte(struct vm_area_struct
*vma
,
6549 unsigned long addr
, pte_t ptent
, swp_entry_t
*entry
)
6551 struct page
*page
= NULL
;
6552 struct address_space
*mapping
;
6555 if (!vma
->vm_file
) /* anonymous vma */
6560 mapping
= vma
->vm_file
->f_mapping
;
6561 if (pte_none(ptent
))
6562 pgoff
= linear_page_index(vma
, addr
);
6563 else /* pte_file(ptent) is true */
6564 pgoff
= pte_to_pgoff(ptent
);
6566 /* page is moved even if it's not RSS of this task(page-faulted). */
6567 page
= find_get_page(mapping
, pgoff
);
6570 /* shmem/tmpfs may report page out on swap: account for that too. */
6571 if (radix_tree_exceptional_entry(page
)) {
6572 swp_entry_t swap
= radix_to_swp_entry(page
);
6573 if (do_swap_account
)
6575 page
= find_get_page(swap_address_space(swap
), swap
.val
);
6581 static enum mc_target_type
get_mctgt_type(struct vm_area_struct
*vma
,
6582 unsigned long addr
, pte_t ptent
, union mc_target
*target
)
6584 struct page
*page
= NULL
;
6585 struct page_cgroup
*pc
;
6586 enum mc_target_type ret
= MC_TARGET_NONE
;
6587 swp_entry_t ent
= { .val
= 0 };
6589 if (pte_present(ptent
))
6590 page
= mc_handle_present_pte(vma
, addr
, ptent
);
6591 else if (is_swap_pte(ptent
))
6592 page
= mc_handle_swap_pte(vma
, addr
, ptent
, &ent
);
6593 else if (pte_none(ptent
) || pte_file(ptent
))
6594 page
= mc_handle_file_pte(vma
, addr
, ptent
, &ent
);
6596 if (!page
&& !ent
.val
)
6599 pc
= lookup_page_cgroup(page
);
6601 * Do only loose check w/o page_cgroup lock.
6602 * mem_cgroup_move_account() checks the pc is valid or not under
6605 if (PageCgroupUsed(pc
) && pc
->mem_cgroup
== mc
.from
) {
6606 ret
= MC_TARGET_PAGE
;
6608 target
->page
= page
;
6610 if (!ret
|| !target
)
6613 /* There is a swap entry and a page doesn't exist or isn't charged */
6614 if (ent
.val
&& !ret
&&
6615 css_id(&mc
.from
->css
) == lookup_swap_cgroup_id(ent
)) {
6616 ret
= MC_TARGET_SWAP
;
6623 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
6625 * We don't consider swapping or file mapped pages because THP does not
6626 * support them for now.
6627 * Caller should make sure that pmd_trans_huge(pmd) is true.
6629 static enum mc_target_type
get_mctgt_type_thp(struct vm_area_struct
*vma
,
6630 unsigned long addr
, pmd_t pmd
, union mc_target
*target
)
6632 struct page
*page
= NULL
;
6633 struct page_cgroup
*pc
;
6634 enum mc_target_type ret
= MC_TARGET_NONE
;
6636 page
= pmd_page(pmd
);
6637 VM_BUG_ON(!page
|| !PageHead(page
));
6640 pc
= lookup_page_cgroup(page
);
6641 if (PageCgroupUsed(pc
) && pc
->mem_cgroup
== mc
.from
) {
6642 ret
= MC_TARGET_PAGE
;
6645 target
->page
= page
;
6651 static inline enum mc_target_type
get_mctgt_type_thp(struct vm_area_struct
*vma
,
6652 unsigned long addr
, pmd_t pmd
, union mc_target
*target
)
6654 return MC_TARGET_NONE
;
6658 static int mem_cgroup_count_precharge_pte_range(pmd_t
*pmd
,
6659 unsigned long addr
, unsigned long end
,
6660 struct mm_walk
*walk
)
6662 struct vm_area_struct
*vma
= walk
->private;
6666 if (pmd_trans_huge_lock(pmd
, vma
) == 1) {
6667 if (get_mctgt_type_thp(vma
, addr
, *pmd
, NULL
) == MC_TARGET_PAGE
)
6668 mc
.precharge
+= HPAGE_PMD_NR
;
6669 spin_unlock(&vma
->vm_mm
->page_table_lock
);
6673 if (pmd_trans_unstable(pmd
))
6675 pte
= pte_offset_map_lock(vma
->vm_mm
, pmd
, addr
, &ptl
);
6676 for (; addr
!= end
; pte
++, addr
+= PAGE_SIZE
)
6677 if (get_mctgt_type(vma
, addr
, *pte
, NULL
))
6678 mc
.precharge
++; /* increment precharge temporarily */
6679 pte_unmap_unlock(pte
- 1, ptl
);
6685 static unsigned long mem_cgroup_count_precharge(struct mm_struct
*mm
)
6687 unsigned long precharge
;
6688 struct vm_area_struct
*vma
;
6690 down_read(&mm
->mmap_sem
);
6691 for (vma
= mm
->mmap
; vma
; vma
= vma
->vm_next
) {
6692 struct mm_walk mem_cgroup_count_precharge_walk
= {
6693 .pmd_entry
= mem_cgroup_count_precharge_pte_range
,
6697 if (is_vm_hugetlb_page(vma
))
6699 walk_page_range(vma
->vm_start
, vma
->vm_end
,
6700 &mem_cgroup_count_precharge_walk
);
6702 up_read(&mm
->mmap_sem
);
6704 precharge
= mc
.precharge
;
6710 static int mem_cgroup_precharge_mc(struct mm_struct
*mm
)
6712 unsigned long precharge
= mem_cgroup_count_precharge(mm
);
6714 VM_BUG_ON(mc
.moving_task
);
6715 mc
.moving_task
= current
;
6716 return mem_cgroup_do_precharge(precharge
);
6719 /* cancels all extra charges on mc.from and mc.to, and wakes up all waiters. */
6720 static void __mem_cgroup_clear_mc(void)
6722 struct mem_cgroup
*from
= mc
.from
;
6723 struct mem_cgroup
*to
= mc
.to
;
6726 /* we must uncharge all the leftover precharges from mc.to */
6728 __mem_cgroup_cancel_charge(mc
.to
, mc
.precharge
);
6732 * we didn't uncharge from mc.from at mem_cgroup_move_account(), so
6733 * we must uncharge here.
6735 if (mc
.moved_charge
) {
6736 __mem_cgroup_cancel_charge(mc
.from
, mc
.moved_charge
);
6737 mc
.moved_charge
= 0;
6739 /* we must fixup refcnts and charges */
6740 if (mc
.moved_swap
) {
6741 /* uncharge swap account from the old cgroup */
6742 if (!mem_cgroup_is_root(mc
.from
))
6743 res_counter_uncharge(&mc
.from
->memsw
,
6744 PAGE_SIZE
* mc
.moved_swap
);
6746 for (i
= 0; i
< mc
.moved_swap
; i
++)
6747 css_put(&mc
.from
->css
);
6749 if (!mem_cgroup_is_root(mc
.to
)) {
6751 * we charged both to->res and to->memsw, so we should
6754 res_counter_uncharge(&mc
.to
->res
,
6755 PAGE_SIZE
* mc
.moved_swap
);
6757 /* we've already done css_get(mc.to) */
6760 memcg_oom_recover(from
);
6761 memcg_oom_recover(to
);
6762 wake_up_all(&mc
.waitq
);
6765 static void mem_cgroup_clear_mc(void)
6767 struct mem_cgroup
*from
= mc
.from
;
6770 * we must clear moving_task before waking up waiters at the end of
6773 mc
.moving_task
= NULL
;
6774 __mem_cgroup_clear_mc();
6775 spin_lock(&mc
.lock
);
6778 spin_unlock(&mc
.lock
);
6779 mem_cgroup_end_move(from
);
6782 static int mem_cgroup_can_attach(struct cgroup
*cgroup
,
6783 struct cgroup_taskset
*tset
)
6785 struct task_struct
*p
= cgroup_taskset_first(tset
);
6787 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cgroup
);
6788 unsigned long move_charge_at_immigrate
;
6791 * We are now commited to this value whatever it is. Changes in this
6792 * tunable will only affect upcoming migrations, not the current one.
6793 * So we need to save it, and keep it going.
6795 move_charge_at_immigrate
= memcg
->move_charge_at_immigrate
;
6796 if (move_charge_at_immigrate
) {
6797 struct mm_struct
*mm
;
6798 struct mem_cgroup
*from
= mem_cgroup_from_task(p
);
6800 VM_BUG_ON(from
== memcg
);
6802 mm
= get_task_mm(p
);
6805 /* We move charges only when we move a owner of the mm */
6806 if (mm
->owner
== p
) {
6809 VM_BUG_ON(mc
.precharge
);
6810 VM_BUG_ON(mc
.moved_charge
);
6811 VM_BUG_ON(mc
.moved_swap
);
6812 mem_cgroup_start_move(from
);
6813 spin_lock(&mc
.lock
);
6816 mc
.immigrate_flags
= move_charge_at_immigrate
;
6817 spin_unlock(&mc
.lock
);
6818 /* We set mc.moving_task later */
6820 ret
= mem_cgroup_precharge_mc(mm
);
6822 mem_cgroup_clear_mc();
6829 static void mem_cgroup_cancel_attach(struct cgroup
*cgroup
,
6830 struct cgroup_taskset
*tset
)
6832 mem_cgroup_clear_mc();
6835 static int mem_cgroup_move_charge_pte_range(pmd_t
*pmd
,
6836 unsigned long addr
, unsigned long end
,
6837 struct mm_walk
*walk
)
6840 struct vm_area_struct
*vma
= walk
->private;
6843 enum mc_target_type target_type
;
6844 union mc_target target
;
6846 struct page_cgroup
*pc
;
6849 * We don't take compound_lock() here but no race with splitting thp
6851 * - if pmd_trans_huge_lock() returns 1, the relevant thp is not
6852 * under splitting, which means there's no concurrent thp split,
6853 * - if another thread runs into split_huge_page() just after we
6854 * entered this if-block, the thread must wait for page table lock
6855 * to be unlocked in __split_huge_page_splitting(), where the main
6856 * part of thp split is not executed yet.
6858 if (pmd_trans_huge_lock(pmd
, vma
) == 1) {
6859 if (mc
.precharge
< HPAGE_PMD_NR
) {
6860 spin_unlock(&vma
->vm_mm
->page_table_lock
);
6863 target_type
= get_mctgt_type_thp(vma
, addr
, *pmd
, &target
);
6864 if (target_type
== MC_TARGET_PAGE
) {
6866 if (!isolate_lru_page(page
)) {
6867 pc
= lookup_page_cgroup(page
);
6868 if (!mem_cgroup_move_account(page
, HPAGE_PMD_NR
,
6869 pc
, mc
.from
, mc
.to
)) {
6870 mc
.precharge
-= HPAGE_PMD_NR
;
6871 mc
.moved_charge
+= HPAGE_PMD_NR
;
6873 putback_lru_page(page
);
6877 spin_unlock(&vma
->vm_mm
->page_table_lock
);
6881 if (pmd_trans_unstable(pmd
))
6884 pte
= pte_offset_map_lock(vma
->vm_mm
, pmd
, addr
, &ptl
);
6885 for (; addr
!= end
; addr
+= PAGE_SIZE
) {
6886 pte_t ptent
= *(pte
++);
6892 switch (get_mctgt_type(vma
, addr
, ptent
, &target
)) {
6893 case MC_TARGET_PAGE
:
6895 if (isolate_lru_page(page
))
6897 pc
= lookup_page_cgroup(page
);
6898 if (!mem_cgroup_move_account(page
, 1, pc
,
6901 /* we uncharge from mc.from later. */
6904 putback_lru_page(page
);
6905 put
: /* get_mctgt_type() gets the page */
6908 case MC_TARGET_SWAP
:
6910 if (!mem_cgroup_move_swap_account(ent
, mc
.from
, mc
.to
)) {
6912 /* we fixup refcnts and charges later. */
6920 pte_unmap_unlock(pte
- 1, ptl
);
6925 * We have consumed all precharges we got in can_attach().
6926 * We try charge one by one, but don't do any additional
6927 * charges to mc.to if we have failed in charge once in attach()
6930 ret
= mem_cgroup_do_precharge(1);
6938 static void mem_cgroup_move_charge(struct mm_struct
*mm
)
6940 struct vm_area_struct
*vma
;
6942 lru_add_drain_all();
6944 if (unlikely(!down_read_trylock(&mm
->mmap_sem
))) {
6946 * Someone who are holding the mmap_sem might be waiting in
6947 * waitq. So we cancel all extra charges, wake up all waiters,
6948 * and retry. Because we cancel precharges, we might not be able
6949 * to move enough charges, but moving charge is a best-effort
6950 * feature anyway, so it wouldn't be a big problem.
6952 __mem_cgroup_clear_mc();
6956 for (vma
= mm
->mmap
; vma
; vma
= vma
->vm_next
) {
6958 struct mm_walk mem_cgroup_move_charge_walk
= {
6959 .pmd_entry
= mem_cgroup_move_charge_pte_range
,
6963 if (is_vm_hugetlb_page(vma
))
6965 ret
= walk_page_range(vma
->vm_start
, vma
->vm_end
,
6966 &mem_cgroup_move_charge_walk
);
6969 * means we have consumed all precharges and failed in
6970 * doing additional charge. Just abandon here.
6974 up_read(&mm
->mmap_sem
);
6977 static void mem_cgroup_move_task(struct cgroup
*cont
,
6978 struct cgroup_taskset
*tset
)
6980 struct task_struct
*p
= cgroup_taskset_first(tset
);
6981 struct mm_struct
*mm
= get_task_mm(p
);
6985 mem_cgroup_move_charge(mm
);
6989 mem_cgroup_clear_mc();
6991 #else /* !CONFIG_MMU */
6992 static int mem_cgroup_can_attach(struct cgroup
*cgroup
,
6993 struct cgroup_taskset
*tset
)
6997 static void mem_cgroup_cancel_attach(struct cgroup
*cgroup
,
6998 struct cgroup_taskset
*tset
)
7001 static void mem_cgroup_move_task(struct cgroup
*cont
,
7002 struct cgroup_taskset
*tset
)
7008 * Cgroup retains root cgroups across [un]mount cycles making it necessary
7009 * to verify sane_behavior flag on each mount attempt.
7011 static void mem_cgroup_bind(struct cgroup
*root
)
7014 * use_hierarchy is forced with sane_behavior. cgroup core
7015 * guarantees that @root doesn't have any children, so turning it
7016 * on for the root memcg is enough.
7018 if (cgroup_sane_behavior(root
))
7019 mem_cgroup_from_cont(root
)->use_hierarchy
= true;
7022 struct cgroup_subsys mem_cgroup_subsys
= {
7024 .subsys_id
= mem_cgroup_subsys_id
,
7025 .css_alloc
= mem_cgroup_css_alloc
,
7026 .css_online
= mem_cgroup_css_online
,
7027 .css_offline
= mem_cgroup_css_offline
,
7028 .css_free
= mem_cgroup_css_free
,
7029 .can_attach
= mem_cgroup_can_attach
,
7030 .cancel_attach
= mem_cgroup_cancel_attach
,
7031 .attach
= mem_cgroup_move_task
,
7032 .bind
= mem_cgroup_bind
,
7033 .base_cftypes
= mem_cgroup_files
,
7038 #ifdef CONFIG_MEMCG_SWAP
7039 static int __init
enable_swap_account(char *s
)
7041 /* consider enabled if no parameter or 1 is given */
7042 if (!strcmp(s
, "1"))
7043 really_do_swap_account
= 1;
7044 else if (!strcmp(s
, "0"))
7045 really_do_swap_account
= 0;
7048 __setup("swapaccount=", enable_swap_account
);
7050 static void __init
memsw_file_init(void)
7052 WARN_ON(cgroup_add_cftypes(&mem_cgroup_subsys
, memsw_cgroup_files
));
7055 static void __init
enable_swap_cgroup(void)
7057 if (!mem_cgroup_disabled() && really_do_swap_account
) {
7058 do_swap_account
= 1;
7064 static void __init
enable_swap_cgroup(void)
7070 * subsys_initcall() for memory controller.
7072 * Some parts like hotcpu_notifier() have to be initialized from this context
7073 * because of lock dependencies (cgroup_lock -> cpu hotplug) but basically
7074 * everything that doesn't depend on a specific mem_cgroup structure should
7075 * be initialized from here.
7077 static int __init
mem_cgroup_init(void)
7079 hotcpu_notifier(memcg_cpu_hotplug_callback
, 0);
7080 enable_swap_cgroup();
7081 mem_cgroup_soft_limit_tree_init();
7085 subsys_initcall(mem_cgroup_init
);