1 /* memcontrol.c - Memory Controller
3 * Copyright IBM Corporation, 2007
4 * Author Balbir Singh <balbir@linux.vnet.ibm.com>
6 * Copyright 2007 OpenVZ SWsoft Inc
7 * Author: Pavel Emelianov <xemul@openvz.org>
10 * Copyright (C) 2009 Nokia Corporation
11 * Author: Kirill A. Shutemov
13 * Kernel Memory Controller
14 * Copyright (C) 2012 Parallels Inc. and Google Inc.
15 * Authors: Glauber Costa and Suleiman Souhlal
17 * This program is free software; you can redistribute it and/or modify
18 * it under the terms of the GNU General Public License as published by
19 * the Free Software Foundation; either version 2 of the License, or
20 * (at your option) any later version.
22 * This program is distributed in the hope that it will be useful,
23 * but WITHOUT ANY WARRANTY; without even the implied warranty of
24 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
25 * GNU General Public License for more details.
28 #include <linux/res_counter.h>
29 #include <linux/memcontrol.h>
30 #include <linux/cgroup.h>
32 #include <linux/hugetlb.h>
33 #include <linux/pagemap.h>
34 #include <linux/smp.h>
35 #include <linux/page-flags.h>
36 #include <linux/backing-dev.h>
37 #include <linux/bit_spinlock.h>
38 #include <linux/rcupdate.h>
39 #include <linux/limits.h>
40 #include <linux/export.h>
41 #include <linux/mutex.h>
42 #include <linux/rbtree.h>
43 #include <linux/slab.h>
44 #include <linux/swap.h>
45 #include <linux/swapops.h>
46 #include <linux/spinlock.h>
47 #include <linux/eventfd.h>
48 #include <linux/sort.h>
50 #include <linux/seq_file.h>
51 #include <linux/vmalloc.h>
52 #include <linux/vmpressure.h>
53 #include <linux/mm_inline.h>
54 #include <linux/page_cgroup.h>
55 #include <linux/cpu.h>
56 #include <linux/oom.h>
60 #include <net/tcp_memcontrol.h>
62 #include <asm/uaccess.h>
64 #include <trace/events/vmscan.h>
66 struct cgroup_subsys mem_cgroup_subsys __read_mostly
;
67 EXPORT_SYMBOL(mem_cgroup_subsys
);
69 #define MEM_CGROUP_RECLAIM_RETRIES 5
70 static struct mem_cgroup
*root_mem_cgroup __read_mostly
;
72 #ifdef CONFIG_MEMCG_SWAP
73 /* Turned on only when memory cgroup is enabled && really_do_swap_account = 1 */
74 int do_swap_account __read_mostly
;
76 /* for remember boot option*/
77 #ifdef CONFIG_MEMCG_SWAP_ENABLED
78 static int really_do_swap_account __initdata
= 1;
80 static int really_do_swap_account __initdata
= 0;
84 #define do_swap_account 0
89 * Statistics for memory cgroup.
91 enum mem_cgroup_stat_index
{
93 * For MEM_CONTAINER_TYPE_ALL, usage = pagecache + rss.
95 MEM_CGROUP_STAT_CACHE
, /* # of pages charged as cache */
96 MEM_CGROUP_STAT_RSS
, /* # of pages charged as anon rss */
97 MEM_CGROUP_STAT_RSS_HUGE
, /* # of pages charged as anon huge */
98 MEM_CGROUP_STAT_FILE_MAPPED
, /* # of pages charged as file rss */
99 MEM_CGROUP_STAT_SWAP
, /* # of pages, swapped out */
100 MEM_CGROUP_STAT_NSTATS
,
103 static const char * const mem_cgroup_stat_names
[] = {
111 enum mem_cgroup_events_index
{
112 MEM_CGROUP_EVENTS_PGPGIN
, /* # of pages paged in */
113 MEM_CGROUP_EVENTS_PGPGOUT
, /* # of pages paged out */
114 MEM_CGROUP_EVENTS_PGFAULT
, /* # of page-faults */
115 MEM_CGROUP_EVENTS_PGMAJFAULT
, /* # of major page-faults */
116 MEM_CGROUP_EVENTS_NSTATS
,
119 static const char * const mem_cgroup_events_names
[] = {
126 static const char * const mem_cgroup_lru_names
[] = {
135 * Per memcg event counter is incremented at every pagein/pageout. With THP,
136 * it will be incremated by the number of pages. This counter is used for
137 * for trigger some periodic events. This is straightforward and better
138 * than using jiffies etc. to handle periodic memcg event.
140 enum mem_cgroup_events_target
{
141 MEM_CGROUP_TARGET_THRESH
,
142 MEM_CGROUP_TARGET_SOFTLIMIT
,
143 MEM_CGROUP_TARGET_NUMAINFO
,
146 #define THRESHOLDS_EVENTS_TARGET 128
147 #define SOFTLIMIT_EVENTS_TARGET 1024
148 #define NUMAINFO_EVENTS_TARGET 1024
150 struct mem_cgroup_stat_cpu
{
151 long count
[MEM_CGROUP_STAT_NSTATS
];
152 unsigned long events
[MEM_CGROUP_EVENTS_NSTATS
];
153 unsigned long nr_page_events
;
154 unsigned long targets
[MEM_CGROUP_NTARGETS
];
157 struct mem_cgroup_reclaim_iter
{
159 * last scanned hierarchy member. Valid only if last_dead_count
160 * matches memcg->dead_count of the hierarchy root group.
162 struct mem_cgroup
*last_visited
;
163 unsigned long last_dead_count
;
165 /* scan generation, increased every round-trip */
166 unsigned int generation
;
170 * per-zone information in memory controller.
172 struct mem_cgroup_per_zone
{
173 struct lruvec lruvec
;
174 unsigned long lru_size
[NR_LRU_LISTS
];
176 struct mem_cgroup_reclaim_iter reclaim_iter
[DEF_PRIORITY
+ 1];
178 struct rb_node tree_node
; /* RB tree node */
179 unsigned long long usage_in_excess
;/* Set to the value by which */
180 /* the soft limit is exceeded*/
182 struct mem_cgroup
*memcg
; /* Back pointer, we cannot */
183 /* use container_of */
186 struct mem_cgroup_per_node
{
187 struct mem_cgroup_per_zone zoneinfo
[MAX_NR_ZONES
];
190 struct mem_cgroup_lru_info
{
191 struct mem_cgroup_per_node
*nodeinfo
[0];
195 * Cgroups above their limits are maintained in a RB-Tree, independent of
196 * their hierarchy representation
199 struct mem_cgroup_tree_per_zone
{
200 struct rb_root rb_root
;
204 struct mem_cgroup_tree_per_node
{
205 struct mem_cgroup_tree_per_zone rb_tree_per_zone
[MAX_NR_ZONES
];
208 struct mem_cgroup_tree
{
209 struct mem_cgroup_tree_per_node
*rb_tree_per_node
[MAX_NUMNODES
];
212 static struct mem_cgroup_tree soft_limit_tree __read_mostly
;
214 struct mem_cgroup_threshold
{
215 struct eventfd_ctx
*eventfd
;
220 struct mem_cgroup_threshold_ary
{
221 /* An array index points to threshold just below or equal to usage. */
222 int current_threshold
;
223 /* Size of entries[] */
225 /* Array of thresholds */
226 struct mem_cgroup_threshold entries
[0];
229 struct mem_cgroup_thresholds
{
230 /* Primary thresholds array */
231 struct mem_cgroup_threshold_ary
*primary
;
233 * Spare threshold array.
234 * This is needed to make mem_cgroup_unregister_event() "never fail".
235 * It must be able to store at least primary->size - 1 entries.
237 struct mem_cgroup_threshold_ary
*spare
;
241 struct mem_cgroup_eventfd_list
{
242 struct list_head list
;
243 struct eventfd_ctx
*eventfd
;
246 static void mem_cgroup_threshold(struct mem_cgroup
*memcg
);
247 static void mem_cgroup_oom_notify(struct mem_cgroup
*memcg
);
250 * The memory controller data structure. The memory controller controls both
251 * page cache and RSS per cgroup. We would eventually like to provide
252 * statistics based on the statistics developed by Rik Van Riel for clock-pro,
253 * to help the administrator determine what knobs to tune.
255 * TODO: Add a water mark for the memory controller. Reclaim will begin when
256 * we hit the water mark. May be even add a low water mark, such that
257 * no reclaim occurs from a cgroup at it's low water mark, this is
258 * a feature that will be implemented much later in the future.
261 struct cgroup_subsys_state css
;
263 * the counter to account for memory usage
265 struct res_counter res
;
267 /* vmpressure notifications */
268 struct vmpressure vmpressure
;
272 * the counter to account for mem+swap usage.
274 struct res_counter memsw
;
277 * rcu_freeing is used only when freeing struct mem_cgroup,
278 * so put it into a union to avoid wasting more memory.
279 * It must be disjoint from the css field. It could be
280 * in a union with the res field, but res plays a much
281 * larger part in mem_cgroup life than memsw, and might
282 * be of interest, even at time of free, when debugging.
283 * So share rcu_head with the less interesting memsw.
285 struct rcu_head rcu_freeing
;
287 * We also need some space for a worker in deferred freeing.
288 * By the time we call it, rcu_freeing is no longer in use.
290 struct work_struct work_freeing
;
294 * the counter to account for kernel memory usage.
296 struct res_counter kmem
;
298 * Should the accounting and control be hierarchical, per subtree?
301 unsigned long kmem_account_flags
; /* See KMEM_ACCOUNTED_*, below */
309 /* OOM-Killer disable */
310 int oom_kill_disable
;
312 /* set when res.limit == memsw.limit */
313 bool memsw_is_minimum
;
315 /* protect arrays of thresholds */
316 struct mutex thresholds_lock
;
318 /* thresholds for memory usage. RCU-protected */
319 struct mem_cgroup_thresholds thresholds
;
321 /* thresholds for mem+swap usage. RCU-protected */
322 struct mem_cgroup_thresholds memsw_thresholds
;
324 /* For oom notifier event fd */
325 struct list_head oom_notify
;
328 * Should we move charges of a task when a task is moved into this
329 * mem_cgroup ? And what type of charges should we move ?
331 unsigned long move_charge_at_immigrate
;
333 * set > 0 if pages under this cgroup are moving to other cgroup.
335 atomic_t moving_account
;
336 /* taken only while moving_account > 0 */
337 spinlock_t move_lock
;
341 struct mem_cgroup_stat_cpu __percpu
*stat
;
343 * used when a cpu is offlined or other synchronizations
344 * See mem_cgroup_read_stat().
346 struct mem_cgroup_stat_cpu nocpu_base
;
347 spinlock_t pcp_counter_lock
;
350 #if defined(CONFIG_MEMCG_KMEM) && defined(CONFIG_INET)
351 struct tcp_memcontrol tcp_mem
;
353 #if defined(CONFIG_MEMCG_KMEM)
354 /* analogous to slab_common's slab_caches list. per-memcg */
355 struct list_head memcg_slab_caches
;
356 /* Not a spinlock, we can take a lot of time walking the list */
357 struct mutex slab_caches_mutex
;
358 /* Index in the kmem_cache->memcg_params->memcg_caches array */
362 int last_scanned_node
;
364 nodemask_t scan_nodes
;
365 atomic_t numainfo_events
;
366 atomic_t numainfo_updating
;
370 * Per cgroup active and inactive list, similar to the
371 * per zone LRU lists.
373 * WARNING: This has to be the last element of the struct. Don't
374 * add new fields after this point.
376 struct mem_cgroup_lru_info info
;
379 static size_t memcg_size(void)
381 return sizeof(struct mem_cgroup
) +
382 nr_node_ids
* sizeof(struct mem_cgroup_per_node
);
385 /* internal only representation about the status of kmem accounting. */
387 KMEM_ACCOUNTED_ACTIVE
= 0, /* accounted by this cgroup itself */
388 KMEM_ACCOUNTED_ACTIVATED
, /* static key enabled. */
389 KMEM_ACCOUNTED_DEAD
, /* dead memcg with pending kmem charges */
392 /* We account when limit is on, but only after call sites are patched */
393 #define KMEM_ACCOUNTED_MASK \
394 ((1 << KMEM_ACCOUNTED_ACTIVE) | (1 << KMEM_ACCOUNTED_ACTIVATED))
396 #ifdef CONFIG_MEMCG_KMEM
397 static inline void memcg_kmem_set_active(struct mem_cgroup
*memcg
)
399 set_bit(KMEM_ACCOUNTED_ACTIVE
, &memcg
->kmem_account_flags
);
402 static bool memcg_kmem_is_active(struct mem_cgroup
*memcg
)
404 return test_bit(KMEM_ACCOUNTED_ACTIVE
, &memcg
->kmem_account_flags
);
407 static void memcg_kmem_set_activated(struct mem_cgroup
*memcg
)
409 set_bit(KMEM_ACCOUNTED_ACTIVATED
, &memcg
->kmem_account_flags
);
412 static void memcg_kmem_clear_activated(struct mem_cgroup
*memcg
)
414 clear_bit(KMEM_ACCOUNTED_ACTIVATED
, &memcg
->kmem_account_flags
);
417 static void memcg_kmem_mark_dead(struct mem_cgroup
*memcg
)
419 if (test_bit(KMEM_ACCOUNTED_ACTIVE
, &memcg
->kmem_account_flags
))
420 set_bit(KMEM_ACCOUNTED_DEAD
, &memcg
->kmem_account_flags
);
423 static bool memcg_kmem_test_and_clear_dead(struct mem_cgroup
*memcg
)
425 return test_and_clear_bit(KMEM_ACCOUNTED_DEAD
,
426 &memcg
->kmem_account_flags
);
430 /* Stuffs for move charges at task migration. */
432 * Types of charges to be moved. "move_charge_at_immitgrate" and
433 * "immigrate_flags" are treated as a left-shifted bitmap of these types.
436 MOVE_CHARGE_TYPE_ANON
, /* private anonymous page and swap of it */
437 MOVE_CHARGE_TYPE_FILE
, /* file page(including tmpfs) and swap of it */
441 /* "mc" and its members are protected by cgroup_mutex */
442 static struct move_charge_struct
{
443 spinlock_t lock
; /* for from, to */
444 struct mem_cgroup
*from
;
445 struct mem_cgroup
*to
;
446 unsigned long immigrate_flags
;
447 unsigned long precharge
;
448 unsigned long moved_charge
;
449 unsigned long moved_swap
;
450 struct task_struct
*moving_task
; /* a task moving charges */
451 wait_queue_head_t waitq
; /* a waitq for other context */
453 .lock
= __SPIN_LOCK_UNLOCKED(mc
.lock
),
454 .waitq
= __WAIT_QUEUE_HEAD_INITIALIZER(mc
.waitq
),
457 static bool move_anon(void)
459 return test_bit(MOVE_CHARGE_TYPE_ANON
, &mc
.immigrate_flags
);
462 static bool move_file(void)
464 return test_bit(MOVE_CHARGE_TYPE_FILE
, &mc
.immigrate_flags
);
468 * Maximum loops in mem_cgroup_hierarchical_reclaim(), used for soft
469 * limit reclaim to prevent infinite loops, if they ever occur.
471 #define MEM_CGROUP_MAX_RECLAIM_LOOPS 100
472 #define MEM_CGROUP_MAX_SOFT_LIMIT_RECLAIM_LOOPS 2
475 MEM_CGROUP_CHARGE_TYPE_CACHE
= 0,
476 MEM_CGROUP_CHARGE_TYPE_ANON
,
477 MEM_CGROUP_CHARGE_TYPE_SWAPOUT
, /* for accounting swapcache */
478 MEM_CGROUP_CHARGE_TYPE_DROP
, /* a page was unused swap cache */
482 /* for encoding cft->private value on file */
490 #define MEMFILE_PRIVATE(x, val) ((x) << 16 | (val))
491 #define MEMFILE_TYPE(val) ((val) >> 16 & 0xffff)
492 #define MEMFILE_ATTR(val) ((val) & 0xffff)
493 /* Used for OOM nofiier */
494 #define OOM_CONTROL (0)
497 * Reclaim flags for mem_cgroup_hierarchical_reclaim
499 #define MEM_CGROUP_RECLAIM_NOSWAP_BIT 0x0
500 #define MEM_CGROUP_RECLAIM_NOSWAP (1 << MEM_CGROUP_RECLAIM_NOSWAP_BIT)
501 #define MEM_CGROUP_RECLAIM_SHRINK_BIT 0x1
502 #define MEM_CGROUP_RECLAIM_SHRINK (1 << MEM_CGROUP_RECLAIM_SHRINK_BIT)
505 * The memcg_create_mutex will be held whenever a new cgroup is created.
506 * As a consequence, any change that needs to protect against new child cgroups
507 * appearing has to hold it as well.
509 static DEFINE_MUTEX(memcg_create_mutex
);
511 static void mem_cgroup_get(struct mem_cgroup
*memcg
);
512 static void mem_cgroup_put(struct mem_cgroup
*memcg
);
515 struct mem_cgroup
*mem_cgroup_from_css(struct cgroup_subsys_state
*s
)
517 return container_of(s
, struct mem_cgroup
, css
);
520 /* Some nice accessors for the vmpressure. */
521 struct vmpressure
*memcg_to_vmpressure(struct mem_cgroup
*memcg
)
524 memcg
= root_mem_cgroup
;
525 return &memcg
->vmpressure
;
528 struct cgroup_subsys_state
*vmpressure_to_css(struct vmpressure
*vmpr
)
530 return &container_of(vmpr
, struct mem_cgroup
, vmpressure
)->css
;
533 struct vmpressure
*css_to_vmpressure(struct cgroup_subsys_state
*css
)
535 return &mem_cgroup_from_css(css
)->vmpressure
;
538 static inline bool mem_cgroup_is_root(struct mem_cgroup
*memcg
)
540 return (memcg
== root_mem_cgroup
);
543 /* Writing them here to avoid exposing memcg's inner layout */
544 #if defined(CONFIG_INET) && defined(CONFIG_MEMCG_KMEM)
546 void sock_update_memcg(struct sock
*sk
)
548 if (mem_cgroup_sockets_enabled
) {
549 struct mem_cgroup
*memcg
;
550 struct cg_proto
*cg_proto
;
552 BUG_ON(!sk
->sk_prot
->proto_cgroup
);
554 /* Socket cloning can throw us here with sk_cgrp already
555 * filled. It won't however, necessarily happen from
556 * process context. So the test for root memcg given
557 * the current task's memcg won't help us in this case.
559 * Respecting the original socket's memcg is a better
560 * decision in this case.
563 BUG_ON(mem_cgroup_is_root(sk
->sk_cgrp
->memcg
));
564 mem_cgroup_get(sk
->sk_cgrp
->memcg
);
569 memcg
= mem_cgroup_from_task(current
);
570 cg_proto
= sk
->sk_prot
->proto_cgroup(memcg
);
571 if (!mem_cgroup_is_root(memcg
) && memcg_proto_active(cg_proto
)) {
572 mem_cgroup_get(memcg
);
573 sk
->sk_cgrp
= cg_proto
;
578 EXPORT_SYMBOL(sock_update_memcg
);
580 void sock_release_memcg(struct sock
*sk
)
582 if (mem_cgroup_sockets_enabled
&& sk
->sk_cgrp
) {
583 struct mem_cgroup
*memcg
;
584 WARN_ON(!sk
->sk_cgrp
->memcg
);
585 memcg
= sk
->sk_cgrp
->memcg
;
586 mem_cgroup_put(memcg
);
590 struct cg_proto
*tcp_proto_cgroup(struct mem_cgroup
*memcg
)
592 if (!memcg
|| mem_cgroup_is_root(memcg
))
595 return &memcg
->tcp_mem
.cg_proto
;
597 EXPORT_SYMBOL(tcp_proto_cgroup
);
599 static void disarm_sock_keys(struct mem_cgroup
*memcg
)
601 if (!memcg_proto_activated(&memcg
->tcp_mem
.cg_proto
))
603 static_key_slow_dec(&memcg_socket_limit_enabled
);
606 static void disarm_sock_keys(struct mem_cgroup
*memcg
)
611 #ifdef CONFIG_MEMCG_KMEM
613 * This will be the memcg's index in each cache's ->memcg_params->memcg_caches.
614 * There are two main reasons for not using the css_id for this:
615 * 1) this works better in sparse environments, where we have a lot of memcgs,
616 * but only a few kmem-limited. Or also, if we have, for instance, 200
617 * memcgs, and none but the 200th is kmem-limited, we'd have to have a
618 * 200 entry array for that.
620 * 2) In order not to violate the cgroup API, we would like to do all memory
621 * allocation in ->create(). At that point, we haven't yet allocated the
622 * css_id. Having a separate index prevents us from messing with the cgroup
625 * The current size of the caches array is stored in
626 * memcg_limited_groups_array_size. It will double each time we have to
629 static DEFINE_IDA(kmem_limited_groups
);
630 int memcg_limited_groups_array_size
;
633 * MIN_SIZE is different than 1, because we would like to avoid going through
634 * the alloc/free process all the time. In a small machine, 4 kmem-limited
635 * cgroups is a reasonable guess. In the future, it could be a parameter or
636 * tunable, but that is strictly not necessary.
638 * MAX_SIZE should be as large as the number of css_ids. Ideally, we could get
639 * this constant directly from cgroup, but it is understandable that this is
640 * better kept as an internal representation in cgroup.c. In any case, the
641 * css_id space is not getting any smaller, and we don't have to necessarily
642 * increase ours as well if it increases.
644 #define MEMCG_CACHES_MIN_SIZE 4
645 #define MEMCG_CACHES_MAX_SIZE 65535
648 * A lot of the calls to the cache allocation functions are expected to be
649 * inlined by the compiler. Since the calls to memcg_kmem_get_cache are
650 * conditional to this static branch, we'll have to allow modules that does
651 * kmem_cache_alloc and the such to see this symbol as well
653 struct static_key memcg_kmem_enabled_key
;
654 EXPORT_SYMBOL(memcg_kmem_enabled_key
);
656 static void disarm_kmem_keys(struct mem_cgroup
*memcg
)
658 if (memcg_kmem_is_active(memcg
)) {
659 static_key_slow_dec(&memcg_kmem_enabled_key
);
660 ida_simple_remove(&kmem_limited_groups
, memcg
->kmemcg_id
);
663 * This check can't live in kmem destruction function,
664 * since the charges will outlive the cgroup
666 WARN_ON(res_counter_read_u64(&memcg
->kmem
, RES_USAGE
) != 0);
669 static void disarm_kmem_keys(struct mem_cgroup
*memcg
)
672 #endif /* CONFIG_MEMCG_KMEM */
674 static void disarm_static_keys(struct mem_cgroup
*memcg
)
676 disarm_sock_keys(memcg
);
677 disarm_kmem_keys(memcg
);
680 static void drain_all_stock_async(struct mem_cgroup
*memcg
);
682 static struct mem_cgroup_per_zone
*
683 mem_cgroup_zoneinfo(struct mem_cgroup
*memcg
, int nid
, int zid
)
685 VM_BUG_ON((unsigned)nid
>= nr_node_ids
);
686 return &memcg
->info
.nodeinfo
[nid
]->zoneinfo
[zid
];
689 struct cgroup_subsys_state
*mem_cgroup_css(struct mem_cgroup
*memcg
)
694 static struct mem_cgroup_per_zone
*
695 page_cgroup_zoneinfo(struct mem_cgroup
*memcg
, struct page
*page
)
697 int nid
= page_to_nid(page
);
698 int zid
= page_zonenum(page
);
700 return mem_cgroup_zoneinfo(memcg
, nid
, zid
);
703 static struct mem_cgroup_tree_per_zone
*
704 soft_limit_tree_node_zone(int nid
, int zid
)
706 return &soft_limit_tree
.rb_tree_per_node
[nid
]->rb_tree_per_zone
[zid
];
709 static struct mem_cgroup_tree_per_zone
*
710 soft_limit_tree_from_page(struct page
*page
)
712 int nid
= page_to_nid(page
);
713 int zid
= page_zonenum(page
);
715 return &soft_limit_tree
.rb_tree_per_node
[nid
]->rb_tree_per_zone
[zid
];
719 __mem_cgroup_insert_exceeded(struct mem_cgroup
*memcg
,
720 struct mem_cgroup_per_zone
*mz
,
721 struct mem_cgroup_tree_per_zone
*mctz
,
722 unsigned long long new_usage_in_excess
)
724 struct rb_node
**p
= &mctz
->rb_root
.rb_node
;
725 struct rb_node
*parent
= NULL
;
726 struct mem_cgroup_per_zone
*mz_node
;
731 mz
->usage_in_excess
= new_usage_in_excess
;
732 if (!mz
->usage_in_excess
)
736 mz_node
= rb_entry(parent
, struct mem_cgroup_per_zone
,
738 if (mz
->usage_in_excess
< mz_node
->usage_in_excess
)
741 * We can't avoid mem cgroups that are over their soft
742 * limit by the same amount
744 else if (mz
->usage_in_excess
>= mz_node
->usage_in_excess
)
747 rb_link_node(&mz
->tree_node
, parent
, p
);
748 rb_insert_color(&mz
->tree_node
, &mctz
->rb_root
);
753 __mem_cgroup_remove_exceeded(struct mem_cgroup
*memcg
,
754 struct mem_cgroup_per_zone
*mz
,
755 struct mem_cgroup_tree_per_zone
*mctz
)
759 rb_erase(&mz
->tree_node
, &mctz
->rb_root
);
764 mem_cgroup_remove_exceeded(struct mem_cgroup
*memcg
,
765 struct mem_cgroup_per_zone
*mz
,
766 struct mem_cgroup_tree_per_zone
*mctz
)
768 spin_lock(&mctz
->lock
);
769 __mem_cgroup_remove_exceeded(memcg
, mz
, mctz
);
770 spin_unlock(&mctz
->lock
);
774 static void mem_cgroup_update_tree(struct mem_cgroup
*memcg
, struct page
*page
)
776 unsigned long long excess
;
777 struct mem_cgroup_per_zone
*mz
;
778 struct mem_cgroup_tree_per_zone
*mctz
;
779 int nid
= page_to_nid(page
);
780 int zid
= page_zonenum(page
);
781 mctz
= soft_limit_tree_from_page(page
);
784 * Necessary to update all ancestors when hierarchy is used.
785 * because their event counter is not touched.
787 for (; memcg
; memcg
= parent_mem_cgroup(memcg
)) {
788 mz
= mem_cgroup_zoneinfo(memcg
, nid
, zid
);
789 excess
= res_counter_soft_limit_excess(&memcg
->res
);
791 * We have to update the tree if mz is on RB-tree or
792 * mem is over its softlimit.
794 if (excess
|| mz
->on_tree
) {
795 spin_lock(&mctz
->lock
);
796 /* if on-tree, remove it */
798 __mem_cgroup_remove_exceeded(memcg
, mz
, mctz
);
800 * Insert again. mz->usage_in_excess will be updated.
801 * If excess is 0, no tree ops.
803 __mem_cgroup_insert_exceeded(memcg
, mz
, mctz
, excess
);
804 spin_unlock(&mctz
->lock
);
809 static void mem_cgroup_remove_from_trees(struct mem_cgroup
*memcg
)
812 struct mem_cgroup_per_zone
*mz
;
813 struct mem_cgroup_tree_per_zone
*mctz
;
815 for_each_node(node
) {
816 for (zone
= 0; zone
< MAX_NR_ZONES
; zone
++) {
817 mz
= mem_cgroup_zoneinfo(memcg
, node
, zone
);
818 mctz
= soft_limit_tree_node_zone(node
, zone
);
819 mem_cgroup_remove_exceeded(memcg
, mz
, mctz
);
824 static struct mem_cgroup_per_zone
*
825 __mem_cgroup_largest_soft_limit_node(struct mem_cgroup_tree_per_zone
*mctz
)
827 struct rb_node
*rightmost
= NULL
;
828 struct mem_cgroup_per_zone
*mz
;
832 rightmost
= rb_last(&mctz
->rb_root
);
834 goto done
; /* Nothing to reclaim from */
836 mz
= rb_entry(rightmost
, struct mem_cgroup_per_zone
, tree_node
);
838 * Remove the node now but someone else can add it back,
839 * we will to add it back at the end of reclaim to its correct
840 * position in the tree.
842 __mem_cgroup_remove_exceeded(mz
->memcg
, mz
, mctz
);
843 if (!res_counter_soft_limit_excess(&mz
->memcg
->res
) ||
844 !css_tryget(&mz
->memcg
->css
))
850 static struct mem_cgroup_per_zone
*
851 mem_cgroup_largest_soft_limit_node(struct mem_cgroup_tree_per_zone
*mctz
)
853 struct mem_cgroup_per_zone
*mz
;
855 spin_lock(&mctz
->lock
);
856 mz
= __mem_cgroup_largest_soft_limit_node(mctz
);
857 spin_unlock(&mctz
->lock
);
862 * Implementation Note: reading percpu statistics for memcg.
864 * Both of vmstat[] and percpu_counter has threshold and do periodic
865 * synchronization to implement "quick" read. There are trade-off between
866 * reading cost and precision of value. Then, we may have a chance to implement
867 * a periodic synchronizion of counter in memcg's counter.
869 * But this _read() function is used for user interface now. The user accounts
870 * memory usage by memory cgroup and he _always_ requires exact value because
871 * he accounts memory. Even if we provide quick-and-fuzzy read, we always
872 * have to visit all online cpus and make sum. So, for now, unnecessary
873 * synchronization is not implemented. (just implemented for cpu hotplug)
875 * If there are kernel internal actions which can make use of some not-exact
876 * value, and reading all cpu value can be performance bottleneck in some
877 * common workload, threashold and synchonization as vmstat[] should be
880 static long mem_cgroup_read_stat(struct mem_cgroup
*memcg
,
881 enum mem_cgroup_stat_index idx
)
887 for_each_online_cpu(cpu
)
888 val
+= per_cpu(memcg
->stat
->count
[idx
], cpu
);
889 #ifdef CONFIG_HOTPLUG_CPU
890 spin_lock(&memcg
->pcp_counter_lock
);
891 val
+= memcg
->nocpu_base
.count
[idx
];
892 spin_unlock(&memcg
->pcp_counter_lock
);
898 static void mem_cgroup_swap_statistics(struct mem_cgroup
*memcg
,
901 int val
= (charge
) ? 1 : -1;
902 this_cpu_add(memcg
->stat
->count
[MEM_CGROUP_STAT_SWAP
], val
);
905 static unsigned long mem_cgroup_read_events(struct mem_cgroup
*memcg
,
906 enum mem_cgroup_events_index idx
)
908 unsigned long val
= 0;
911 for_each_online_cpu(cpu
)
912 val
+= per_cpu(memcg
->stat
->events
[idx
], cpu
);
913 #ifdef CONFIG_HOTPLUG_CPU
914 spin_lock(&memcg
->pcp_counter_lock
);
915 val
+= memcg
->nocpu_base
.events
[idx
];
916 spin_unlock(&memcg
->pcp_counter_lock
);
921 static void mem_cgroup_charge_statistics(struct mem_cgroup
*memcg
,
923 bool anon
, int nr_pages
)
928 * Here, RSS means 'mapped anon' and anon's SwapCache. Shmem/tmpfs is
929 * counted as CACHE even if it's on ANON LRU.
932 __this_cpu_add(memcg
->stat
->count
[MEM_CGROUP_STAT_RSS
],
935 __this_cpu_add(memcg
->stat
->count
[MEM_CGROUP_STAT_CACHE
],
938 if (PageTransHuge(page
))
939 __this_cpu_add(memcg
->stat
->count
[MEM_CGROUP_STAT_RSS_HUGE
],
942 /* pagein of a big page is an event. So, ignore page size */
944 __this_cpu_inc(memcg
->stat
->events
[MEM_CGROUP_EVENTS_PGPGIN
]);
946 __this_cpu_inc(memcg
->stat
->events
[MEM_CGROUP_EVENTS_PGPGOUT
]);
947 nr_pages
= -nr_pages
; /* for event */
950 __this_cpu_add(memcg
->stat
->nr_page_events
, nr_pages
);
956 mem_cgroup_get_lru_size(struct lruvec
*lruvec
, enum lru_list lru
)
958 struct mem_cgroup_per_zone
*mz
;
960 mz
= container_of(lruvec
, struct mem_cgroup_per_zone
, lruvec
);
961 return mz
->lru_size
[lru
];
965 mem_cgroup_zone_nr_lru_pages(struct mem_cgroup
*memcg
, int nid
, int zid
,
966 unsigned int lru_mask
)
968 struct mem_cgroup_per_zone
*mz
;
970 unsigned long ret
= 0;
972 mz
= mem_cgroup_zoneinfo(memcg
, nid
, zid
);
975 if (BIT(lru
) & lru_mask
)
976 ret
+= mz
->lru_size
[lru
];
982 mem_cgroup_node_nr_lru_pages(struct mem_cgroup
*memcg
,
983 int nid
, unsigned int lru_mask
)
988 for (zid
= 0; zid
< MAX_NR_ZONES
; zid
++)
989 total
+= mem_cgroup_zone_nr_lru_pages(memcg
,
995 static unsigned long mem_cgroup_nr_lru_pages(struct mem_cgroup
*memcg
,
996 unsigned int lru_mask
)
1001 for_each_node_state(nid
, N_MEMORY
)
1002 total
+= mem_cgroup_node_nr_lru_pages(memcg
, nid
, lru_mask
);
1006 static bool mem_cgroup_event_ratelimit(struct mem_cgroup
*memcg
,
1007 enum mem_cgroup_events_target target
)
1009 unsigned long val
, next
;
1011 val
= __this_cpu_read(memcg
->stat
->nr_page_events
);
1012 next
= __this_cpu_read(memcg
->stat
->targets
[target
]);
1013 /* from time_after() in jiffies.h */
1014 if ((long)next
- (long)val
< 0) {
1016 case MEM_CGROUP_TARGET_THRESH
:
1017 next
= val
+ THRESHOLDS_EVENTS_TARGET
;
1019 case MEM_CGROUP_TARGET_SOFTLIMIT
:
1020 next
= val
+ SOFTLIMIT_EVENTS_TARGET
;
1022 case MEM_CGROUP_TARGET_NUMAINFO
:
1023 next
= val
+ NUMAINFO_EVENTS_TARGET
;
1028 __this_cpu_write(memcg
->stat
->targets
[target
], next
);
1035 * Check events in order.
1038 static void memcg_check_events(struct mem_cgroup
*memcg
, struct page
*page
)
1041 /* threshold event is triggered in finer grain than soft limit */
1042 if (unlikely(mem_cgroup_event_ratelimit(memcg
,
1043 MEM_CGROUP_TARGET_THRESH
))) {
1045 bool do_numainfo __maybe_unused
;
1047 do_softlimit
= mem_cgroup_event_ratelimit(memcg
,
1048 MEM_CGROUP_TARGET_SOFTLIMIT
);
1049 #if MAX_NUMNODES > 1
1050 do_numainfo
= mem_cgroup_event_ratelimit(memcg
,
1051 MEM_CGROUP_TARGET_NUMAINFO
);
1055 mem_cgroup_threshold(memcg
);
1056 if (unlikely(do_softlimit
))
1057 mem_cgroup_update_tree(memcg
, page
);
1058 #if MAX_NUMNODES > 1
1059 if (unlikely(do_numainfo
))
1060 atomic_inc(&memcg
->numainfo_events
);
1066 struct mem_cgroup
*mem_cgroup_from_cont(struct cgroup
*cont
)
1068 return mem_cgroup_from_css(
1069 cgroup_subsys_state(cont
, mem_cgroup_subsys_id
));
1072 struct mem_cgroup
*mem_cgroup_from_task(struct task_struct
*p
)
1075 * mm_update_next_owner() may clear mm->owner to NULL
1076 * if it races with swapoff, page migration, etc.
1077 * So this can be called with p == NULL.
1082 return mem_cgroup_from_css(task_subsys_state(p
, mem_cgroup_subsys_id
));
1085 struct mem_cgroup
*try_get_mem_cgroup_from_mm(struct mm_struct
*mm
)
1087 struct mem_cgroup
*memcg
= NULL
;
1092 * Because we have no locks, mm->owner's may be being moved to other
1093 * cgroup. We use css_tryget() here even if this looks
1094 * pessimistic (rather than adding locks here).
1098 memcg
= mem_cgroup_from_task(rcu_dereference(mm
->owner
));
1099 if (unlikely(!memcg
))
1101 } while (!css_tryget(&memcg
->css
));
1107 * Returns a next (in a pre-order walk) alive memcg (with elevated css
1108 * ref. count) or NULL if the whole root's subtree has been visited.
1110 * helper function to be used by mem_cgroup_iter
1112 static struct mem_cgroup
*__mem_cgroup_iter_next(struct mem_cgroup
*root
,
1113 struct mem_cgroup
*last_visited
)
1115 struct cgroup
*prev_cgroup
, *next_cgroup
;
1118 * Root is not visited by cgroup iterators so it needs an
1124 prev_cgroup
= (last_visited
== root
) ? NULL
1125 : last_visited
->css
.cgroup
;
1127 next_cgroup
= cgroup_next_descendant_pre(
1128 prev_cgroup
, root
->css
.cgroup
);
1131 * Even if we found a group we have to make sure it is
1132 * alive. css && !memcg means that the groups should be
1133 * skipped and we should continue the tree walk.
1134 * last_visited css is safe to use because it is
1135 * protected by css_get and the tree walk is rcu safe.
1138 struct mem_cgroup
*mem
= mem_cgroup_from_cont(
1140 if (css_tryget(&mem
->css
))
1143 prev_cgroup
= next_cgroup
;
1152 * mem_cgroup_iter - iterate over memory cgroup hierarchy
1153 * @root: hierarchy root
1154 * @prev: previously returned memcg, NULL on first invocation
1155 * @reclaim: cookie for shared reclaim walks, NULL for full walks
1157 * Returns references to children of the hierarchy below @root, or
1158 * @root itself, or %NULL after a full round-trip.
1160 * Caller must pass the return value in @prev on subsequent
1161 * invocations for reference counting, or use mem_cgroup_iter_break()
1162 * to cancel a hierarchy walk before the round-trip is complete.
1164 * Reclaimers can specify a zone and a priority level in @reclaim to
1165 * divide up the memcgs in the hierarchy among all concurrent
1166 * reclaimers operating on the same zone and priority.
1168 struct mem_cgroup
*mem_cgroup_iter(struct mem_cgroup
*root
,
1169 struct mem_cgroup
*prev
,
1170 struct mem_cgroup_reclaim_cookie
*reclaim
)
1172 struct mem_cgroup
*memcg
= NULL
;
1173 struct mem_cgroup
*last_visited
= NULL
;
1174 unsigned long uninitialized_var(dead_count
);
1176 if (mem_cgroup_disabled())
1180 root
= root_mem_cgroup
;
1182 if (prev
&& !reclaim
)
1183 last_visited
= prev
;
1185 if (!root
->use_hierarchy
&& root
!= root_mem_cgroup
) {
1193 struct mem_cgroup_reclaim_iter
*uninitialized_var(iter
);
1196 int nid
= zone_to_nid(reclaim
->zone
);
1197 int zid
= zone_idx(reclaim
->zone
);
1198 struct mem_cgroup_per_zone
*mz
;
1200 mz
= mem_cgroup_zoneinfo(root
, nid
, zid
);
1201 iter
= &mz
->reclaim_iter
[reclaim
->priority
];
1202 last_visited
= iter
->last_visited
;
1203 if (prev
&& reclaim
->generation
!= iter
->generation
) {
1204 iter
->last_visited
= NULL
;
1209 * If the dead_count mismatches, a destruction
1210 * has happened or is happening concurrently.
1211 * If the dead_count matches, a destruction
1212 * might still happen concurrently, but since
1213 * we checked under RCU, that destruction
1214 * won't free the object until we release the
1215 * RCU reader lock. Thus, the dead_count
1216 * check verifies the pointer is still valid,
1217 * css_tryget() verifies the cgroup pointed to
1220 dead_count
= atomic_read(&root
->dead_count
);
1222 last_visited
= iter
->last_visited
;
1224 if ((dead_count
!= iter
->last_dead_count
) ||
1225 !css_tryget(&last_visited
->css
)) {
1226 last_visited
= NULL
;
1231 memcg
= __mem_cgroup_iter_next(root
, last_visited
);
1235 css_put(&last_visited
->css
);
1237 iter
->last_visited
= memcg
;
1239 iter
->last_dead_count
= dead_count
;
1243 else if (!prev
&& memcg
)
1244 reclaim
->generation
= iter
->generation
;
1253 if (prev
&& prev
!= root
)
1254 css_put(&prev
->css
);
1260 * mem_cgroup_iter_break - abort a hierarchy walk prematurely
1261 * @root: hierarchy root
1262 * @prev: last visited hierarchy member as returned by mem_cgroup_iter()
1264 void mem_cgroup_iter_break(struct mem_cgroup
*root
,
1265 struct mem_cgroup
*prev
)
1268 root
= root_mem_cgroup
;
1269 if (prev
&& prev
!= root
)
1270 css_put(&prev
->css
);
1274 * Iteration constructs for visiting all cgroups (under a tree). If
1275 * loops are exited prematurely (break), mem_cgroup_iter_break() must
1276 * be used for reference counting.
1278 #define for_each_mem_cgroup_tree(iter, root) \
1279 for (iter = mem_cgroup_iter(root, NULL, NULL); \
1281 iter = mem_cgroup_iter(root, iter, NULL))
1283 #define for_each_mem_cgroup(iter) \
1284 for (iter = mem_cgroup_iter(NULL, NULL, NULL); \
1286 iter = mem_cgroup_iter(NULL, iter, NULL))
1288 void __mem_cgroup_count_vm_event(struct mm_struct
*mm
, enum vm_event_item idx
)
1290 struct mem_cgroup
*memcg
;
1293 memcg
= mem_cgroup_from_task(rcu_dereference(mm
->owner
));
1294 if (unlikely(!memcg
))
1299 this_cpu_inc(memcg
->stat
->events
[MEM_CGROUP_EVENTS_PGFAULT
]);
1302 this_cpu_inc(memcg
->stat
->events
[MEM_CGROUP_EVENTS_PGMAJFAULT
]);
1310 EXPORT_SYMBOL(__mem_cgroup_count_vm_event
);
1313 * mem_cgroup_zone_lruvec - get the lru list vector for a zone and memcg
1314 * @zone: zone of the wanted lruvec
1315 * @memcg: memcg of the wanted lruvec
1317 * Returns the lru list vector holding pages for the given @zone and
1318 * @mem. This can be the global zone lruvec, if the memory controller
1321 struct lruvec
*mem_cgroup_zone_lruvec(struct zone
*zone
,
1322 struct mem_cgroup
*memcg
)
1324 struct mem_cgroup_per_zone
*mz
;
1325 struct lruvec
*lruvec
;
1327 if (mem_cgroup_disabled()) {
1328 lruvec
= &zone
->lruvec
;
1332 mz
= mem_cgroup_zoneinfo(memcg
, zone_to_nid(zone
), zone_idx(zone
));
1333 lruvec
= &mz
->lruvec
;
1336 * Since a node can be onlined after the mem_cgroup was created,
1337 * we have to be prepared to initialize lruvec->zone here;
1338 * and if offlined then reonlined, we need to reinitialize it.
1340 if (unlikely(lruvec
->zone
!= zone
))
1341 lruvec
->zone
= zone
;
1346 * Following LRU functions are allowed to be used without PCG_LOCK.
1347 * Operations are called by routine of global LRU independently from memcg.
1348 * What we have to take care of here is validness of pc->mem_cgroup.
1350 * Changes to pc->mem_cgroup happens when
1353 * In typical case, "charge" is done before add-to-lru. Exception is SwapCache.
1354 * It is added to LRU before charge.
1355 * If PCG_USED bit is not set, page_cgroup is not added to this private LRU.
1356 * When moving account, the page is not on LRU. It's isolated.
1360 * mem_cgroup_page_lruvec - return lruvec for adding an lru page
1362 * @zone: zone of the page
1364 struct lruvec
*mem_cgroup_page_lruvec(struct page
*page
, struct zone
*zone
)
1366 struct mem_cgroup_per_zone
*mz
;
1367 struct mem_cgroup
*memcg
;
1368 struct page_cgroup
*pc
;
1369 struct lruvec
*lruvec
;
1371 if (mem_cgroup_disabled()) {
1372 lruvec
= &zone
->lruvec
;
1376 pc
= lookup_page_cgroup(page
);
1377 memcg
= pc
->mem_cgroup
;
1380 * Surreptitiously switch any uncharged offlist page to root:
1381 * an uncharged page off lru does nothing to secure
1382 * its former mem_cgroup from sudden removal.
1384 * Our caller holds lru_lock, and PageCgroupUsed is updated
1385 * under page_cgroup lock: between them, they make all uses
1386 * of pc->mem_cgroup safe.
1388 if (!PageLRU(page
) && !PageCgroupUsed(pc
) && memcg
!= root_mem_cgroup
)
1389 pc
->mem_cgroup
= memcg
= root_mem_cgroup
;
1391 mz
= page_cgroup_zoneinfo(memcg
, page
);
1392 lruvec
= &mz
->lruvec
;
1395 * Since a node can be onlined after the mem_cgroup was created,
1396 * we have to be prepared to initialize lruvec->zone here;
1397 * and if offlined then reonlined, we need to reinitialize it.
1399 if (unlikely(lruvec
->zone
!= zone
))
1400 lruvec
->zone
= zone
;
1405 * mem_cgroup_update_lru_size - account for adding or removing an lru page
1406 * @lruvec: mem_cgroup per zone lru vector
1407 * @lru: index of lru list the page is sitting on
1408 * @nr_pages: positive when adding or negative when removing
1410 * This function must be called when a page is added to or removed from an
1413 void mem_cgroup_update_lru_size(struct lruvec
*lruvec
, enum lru_list lru
,
1416 struct mem_cgroup_per_zone
*mz
;
1417 unsigned long *lru_size
;
1419 if (mem_cgroup_disabled())
1422 mz
= container_of(lruvec
, struct mem_cgroup_per_zone
, lruvec
);
1423 lru_size
= mz
->lru_size
+ lru
;
1424 *lru_size
+= nr_pages
;
1425 VM_BUG_ON((long)(*lru_size
) < 0);
1429 * Checks whether given mem is same or in the root_mem_cgroup's
1432 bool __mem_cgroup_same_or_subtree(const struct mem_cgroup
*root_memcg
,
1433 struct mem_cgroup
*memcg
)
1435 if (root_memcg
== memcg
)
1437 if (!root_memcg
->use_hierarchy
|| !memcg
)
1439 return css_is_ancestor(&memcg
->css
, &root_memcg
->css
);
1442 static bool mem_cgroup_same_or_subtree(const struct mem_cgroup
*root_memcg
,
1443 struct mem_cgroup
*memcg
)
1448 ret
= __mem_cgroup_same_or_subtree(root_memcg
, memcg
);
1453 int task_in_mem_cgroup(struct task_struct
*task
, const struct mem_cgroup
*memcg
)
1456 struct mem_cgroup
*curr
= NULL
;
1457 struct task_struct
*p
;
1459 p
= find_lock_task_mm(task
);
1461 curr
= try_get_mem_cgroup_from_mm(p
->mm
);
1465 * All threads may have already detached their mm's, but the oom
1466 * killer still needs to detect if they have already been oom
1467 * killed to prevent needlessly killing additional tasks.
1470 curr
= mem_cgroup_from_task(task
);
1472 css_get(&curr
->css
);
1478 * We should check use_hierarchy of "memcg" not "curr". Because checking
1479 * use_hierarchy of "curr" here make this function true if hierarchy is
1480 * enabled in "curr" and "curr" is a child of "memcg" in *cgroup*
1481 * hierarchy(even if use_hierarchy is disabled in "memcg").
1483 ret
= mem_cgroup_same_or_subtree(memcg
, curr
);
1484 css_put(&curr
->css
);
1488 int mem_cgroup_inactive_anon_is_low(struct lruvec
*lruvec
)
1490 unsigned long inactive_ratio
;
1491 unsigned long inactive
;
1492 unsigned long active
;
1495 inactive
= mem_cgroup_get_lru_size(lruvec
, LRU_INACTIVE_ANON
);
1496 active
= mem_cgroup_get_lru_size(lruvec
, LRU_ACTIVE_ANON
);
1498 gb
= (inactive
+ active
) >> (30 - PAGE_SHIFT
);
1500 inactive_ratio
= int_sqrt(10 * gb
);
1504 return inactive
* inactive_ratio
< active
;
1507 #define mem_cgroup_from_res_counter(counter, member) \
1508 container_of(counter, struct mem_cgroup, member)
1511 * mem_cgroup_margin - calculate chargeable space of a memory cgroup
1512 * @memcg: the memory cgroup
1514 * Returns the maximum amount of memory @mem can be charged with, in
1517 static unsigned long mem_cgroup_margin(struct mem_cgroup
*memcg
)
1519 unsigned long long margin
;
1521 margin
= res_counter_margin(&memcg
->res
);
1522 if (do_swap_account
)
1523 margin
= min(margin
, res_counter_margin(&memcg
->memsw
));
1524 return margin
>> PAGE_SHIFT
;
1527 int mem_cgroup_swappiness(struct mem_cgroup
*memcg
)
1529 struct cgroup
*cgrp
= memcg
->css
.cgroup
;
1532 if (cgrp
->parent
== NULL
)
1533 return vm_swappiness
;
1535 return memcg
->swappiness
;
1539 * memcg->moving_account is used for checking possibility that some thread is
1540 * calling move_account(). When a thread on CPU-A starts moving pages under
1541 * a memcg, other threads should check memcg->moving_account under
1542 * rcu_read_lock(), like this:
1546 * memcg->moving_account+1 if (memcg->mocing_account)
1548 * synchronize_rcu() update something.
1553 /* for quick checking without looking up memcg */
1554 atomic_t memcg_moving __read_mostly
;
1556 static void mem_cgroup_start_move(struct mem_cgroup
*memcg
)
1558 atomic_inc(&memcg_moving
);
1559 atomic_inc(&memcg
->moving_account
);
1563 static void mem_cgroup_end_move(struct mem_cgroup
*memcg
)
1566 * Now, mem_cgroup_clear_mc() may call this function with NULL.
1567 * We check NULL in callee rather than caller.
1570 atomic_dec(&memcg_moving
);
1571 atomic_dec(&memcg
->moving_account
);
1576 * 2 routines for checking "mem" is under move_account() or not.
1578 * mem_cgroup_stolen() - checking whether a cgroup is mc.from or not. This
1579 * is used for avoiding races in accounting. If true,
1580 * pc->mem_cgroup may be overwritten.
1582 * mem_cgroup_under_move() - checking a cgroup is mc.from or mc.to or
1583 * under hierarchy of moving cgroups. This is for
1584 * waiting at hith-memory prressure caused by "move".
1587 static bool mem_cgroup_stolen(struct mem_cgroup
*memcg
)
1589 VM_BUG_ON(!rcu_read_lock_held());
1590 return atomic_read(&memcg
->moving_account
) > 0;
1593 static bool mem_cgroup_under_move(struct mem_cgroup
*memcg
)
1595 struct mem_cgroup
*from
;
1596 struct mem_cgroup
*to
;
1599 * Unlike task_move routines, we access mc.to, mc.from not under
1600 * mutual exclusion by cgroup_mutex. Here, we take spinlock instead.
1602 spin_lock(&mc
.lock
);
1608 ret
= mem_cgroup_same_or_subtree(memcg
, from
)
1609 || mem_cgroup_same_or_subtree(memcg
, to
);
1611 spin_unlock(&mc
.lock
);
1615 static bool mem_cgroup_wait_acct_move(struct mem_cgroup
*memcg
)
1617 if (mc
.moving_task
&& current
!= mc
.moving_task
) {
1618 if (mem_cgroup_under_move(memcg
)) {
1620 prepare_to_wait(&mc
.waitq
, &wait
, TASK_INTERRUPTIBLE
);
1621 /* moving charge context might have finished. */
1624 finish_wait(&mc
.waitq
, &wait
);
1632 * Take this lock when
1633 * - a code tries to modify page's memcg while it's USED.
1634 * - a code tries to modify page state accounting in a memcg.
1635 * see mem_cgroup_stolen(), too.
1637 static void move_lock_mem_cgroup(struct mem_cgroup
*memcg
,
1638 unsigned long *flags
)
1640 spin_lock_irqsave(&memcg
->move_lock
, *flags
);
1643 static void move_unlock_mem_cgroup(struct mem_cgroup
*memcg
,
1644 unsigned long *flags
)
1646 spin_unlock_irqrestore(&memcg
->move_lock
, *flags
);
1649 #define K(x) ((x) << (PAGE_SHIFT-10))
1651 * mem_cgroup_print_oom_info: Print OOM information relevant to memory controller.
1652 * @memcg: The memory cgroup that went over limit
1653 * @p: Task that is going to be killed
1655 * NOTE: @memcg and @p's mem_cgroup can be different when hierarchy is
1658 void mem_cgroup_print_oom_info(struct mem_cgroup
*memcg
, struct task_struct
*p
)
1660 struct cgroup
*task_cgrp
;
1661 struct cgroup
*mem_cgrp
;
1663 * Need a buffer in BSS, can't rely on allocations. The code relies
1664 * on the assumption that OOM is serialized for memory controller.
1665 * If this assumption is broken, revisit this code.
1667 static char memcg_name
[PATH_MAX
];
1669 struct mem_cgroup
*iter
;
1677 mem_cgrp
= memcg
->css
.cgroup
;
1678 task_cgrp
= task_cgroup(p
, mem_cgroup_subsys_id
);
1680 ret
= cgroup_path(task_cgrp
, memcg_name
, PATH_MAX
);
1683 * Unfortunately, we are unable to convert to a useful name
1684 * But we'll still print out the usage information
1691 pr_info("Task in %s killed", memcg_name
);
1694 ret
= cgroup_path(mem_cgrp
, memcg_name
, PATH_MAX
);
1702 * Continues from above, so we don't need an KERN_ level
1704 pr_cont(" as a result of limit of %s\n", memcg_name
);
1707 pr_info("memory: usage %llukB, limit %llukB, failcnt %llu\n",
1708 res_counter_read_u64(&memcg
->res
, RES_USAGE
) >> 10,
1709 res_counter_read_u64(&memcg
->res
, RES_LIMIT
) >> 10,
1710 res_counter_read_u64(&memcg
->res
, RES_FAILCNT
));
1711 pr_info("memory+swap: usage %llukB, limit %llukB, failcnt %llu\n",
1712 res_counter_read_u64(&memcg
->memsw
, RES_USAGE
) >> 10,
1713 res_counter_read_u64(&memcg
->memsw
, RES_LIMIT
) >> 10,
1714 res_counter_read_u64(&memcg
->memsw
, RES_FAILCNT
));
1715 pr_info("kmem: usage %llukB, limit %llukB, failcnt %llu\n",
1716 res_counter_read_u64(&memcg
->kmem
, RES_USAGE
) >> 10,
1717 res_counter_read_u64(&memcg
->kmem
, RES_LIMIT
) >> 10,
1718 res_counter_read_u64(&memcg
->kmem
, RES_FAILCNT
));
1720 for_each_mem_cgroup_tree(iter
, memcg
) {
1721 pr_info("Memory cgroup stats");
1724 ret
= cgroup_path(iter
->css
.cgroup
, memcg_name
, PATH_MAX
);
1726 pr_cont(" for %s", memcg_name
);
1730 for (i
= 0; i
< MEM_CGROUP_STAT_NSTATS
; i
++) {
1731 if (i
== MEM_CGROUP_STAT_SWAP
&& !do_swap_account
)
1733 pr_cont(" %s:%ldKB", mem_cgroup_stat_names
[i
],
1734 K(mem_cgroup_read_stat(iter
, i
)));
1737 for (i
= 0; i
< NR_LRU_LISTS
; i
++)
1738 pr_cont(" %s:%luKB", mem_cgroup_lru_names
[i
],
1739 K(mem_cgroup_nr_lru_pages(iter
, BIT(i
))));
1746 * This function returns the number of memcg under hierarchy tree. Returns
1747 * 1(self count) if no children.
1749 static int mem_cgroup_count_children(struct mem_cgroup
*memcg
)
1752 struct mem_cgroup
*iter
;
1754 for_each_mem_cgroup_tree(iter
, memcg
)
1760 * Return the memory (and swap, if configured) limit for a memcg.
1762 static u64
mem_cgroup_get_limit(struct mem_cgroup
*memcg
)
1766 limit
= res_counter_read_u64(&memcg
->res
, RES_LIMIT
);
1769 * Do not consider swap space if we cannot swap due to swappiness
1771 if (mem_cgroup_swappiness(memcg
)) {
1774 limit
+= total_swap_pages
<< PAGE_SHIFT
;
1775 memsw
= res_counter_read_u64(&memcg
->memsw
, RES_LIMIT
);
1778 * If memsw is finite and limits the amount of swap space
1779 * available to this memcg, return that limit.
1781 limit
= min(limit
, memsw
);
1787 static void mem_cgroup_out_of_memory(struct mem_cgroup
*memcg
, gfp_t gfp_mask
,
1790 struct mem_cgroup
*iter
;
1791 unsigned long chosen_points
= 0;
1792 unsigned long totalpages
;
1793 unsigned int points
= 0;
1794 struct task_struct
*chosen
= NULL
;
1797 * If current has a pending SIGKILL or is exiting, then automatically
1798 * select it. The goal is to allow it to allocate so that it may
1799 * quickly exit and free its memory.
1801 if (fatal_signal_pending(current
) || current
->flags
& PF_EXITING
) {
1802 set_thread_flag(TIF_MEMDIE
);
1806 check_panic_on_oom(CONSTRAINT_MEMCG
, gfp_mask
, order
, NULL
);
1807 totalpages
= mem_cgroup_get_limit(memcg
) >> PAGE_SHIFT
? : 1;
1808 for_each_mem_cgroup_tree(iter
, memcg
) {
1809 struct cgroup
*cgroup
= iter
->css
.cgroup
;
1810 struct cgroup_iter it
;
1811 struct task_struct
*task
;
1813 cgroup_iter_start(cgroup
, &it
);
1814 while ((task
= cgroup_iter_next(cgroup
, &it
))) {
1815 switch (oom_scan_process_thread(task
, totalpages
, NULL
,
1817 case OOM_SCAN_SELECT
:
1819 put_task_struct(chosen
);
1821 chosen_points
= ULONG_MAX
;
1822 get_task_struct(chosen
);
1824 case OOM_SCAN_CONTINUE
:
1826 case OOM_SCAN_ABORT
:
1827 cgroup_iter_end(cgroup
, &it
);
1828 mem_cgroup_iter_break(memcg
, iter
);
1830 put_task_struct(chosen
);
1835 points
= oom_badness(task
, memcg
, NULL
, totalpages
);
1836 if (points
> chosen_points
) {
1838 put_task_struct(chosen
);
1840 chosen_points
= points
;
1841 get_task_struct(chosen
);
1844 cgroup_iter_end(cgroup
, &it
);
1849 points
= chosen_points
* 1000 / totalpages
;
1850 oom_kill_process(chosen
, gfp_mask
, order
, points
, totalpages
, memcg
,
1851 NULL
, "Memory cgroup out of memory");
1854 static unsigned long mem_cgroup_reclaim(struct mem_cgroup
*memcg
,
1856 unsigned long flags
)
1858 unsigned long total
= 0;
1859 bool noswap
= false;
1862 if (flags
& MEM_CGROUP_RECLAIM_NOSWAP
)
1864 if (!(flags
& MEM_CGROUP_RECLAIM_SHRINK
) && memcg
->memsw_is_minimum
)
1867 for (loop
= 0; loop
< MEM_CGROUP_MAX_RECLAIM_LOOPS
; loop
++) {
1869 drain_all_stock_async(memcg
);
1870 total
+= try_to_free_mem_cgroup_pages(memcg
, gfp_mask
, noswap
);
1872 * Allow limit shrinkers, which are triggered directly
1873 * by userspace, to catch signals and stop reclaim
1874 * after minimal progress, regardless of the margin.
1876 if (total
&& (flags
& MEM_CGROUP_RECLAIM_SHRINK
))
1878 if (mem_cgroup_margin(memcg
))
1881 * If nothing was reclaimed after two attempts, there
1882 * may be no reclaimable pages in this hierarchy.
1891 * test_mem_cgroup_node_reclaimable
1892 * @memcg: the target memcg
1893 * @nid: the node ID to be checked.
1894 * @noswap : specify true here if the user wants flle only information.
1896 * This function returns whether the specified memcg contains any
1897 * reclaimable pages on a node. Returns true if there are any reclaimable
1898 * pages in the node.
1900 static bool test_mem_cgroup_node_reclaimable(struct mem_cgroup
*memcg
,
1901 int nid
, bool noswap
)
1903 if (mem_cgroup_node_nr_lru_pages(memcg
, nid
, LRU_ALL_FILE
))
1905 if (noswap
|| !total_swap_pages
)
1907 if (mem_cgroup_node_nr_lru_pages(memcg
, nid
, LRU_ALL_ANON
))
1912 #if MAX_NUMNODES > 1
1915 * Always updating the nodemask is not very good - even if we have an empty
1916 * list or the wrong list here, we can start from some node and traverse all
1917 * nodes based on the zonelist. So update the list loosely once per 10 secs.
1920 static void mem_cgroup_may_update_nodemask(struct mem_cgroup
*memcg
)
1924 * numainfo_events > 0 means there was at least NUMAINFO_EVENTS_TARGET
1925 * pagein/pageout changes since the last update.
1927 if (!atomic_read(&memcg
->numainfo_events
))
1929 if (atomic_inc_return(&memcg
->numainfo_updating
) > 1)
1932 /* make a nodemask where this memcg uses memory from */
1933 memcg
->scan_nodes
= node_states
[N_MEMORY
];
1935 for_each_node_mask(nid
, node_states
[N_MEMORY
]) {
1937 if (!test_mem_cgroup_node_reclaimable(memcg
, nid
, false))
1938 node_clear(nid
, memcg
->scan_nodes
);
1941 atomic_set(&memcg
->numainfo_events
, 0);
1942 atomic_set(&memcg
->numainfo_updating
, 0);
1946 * Selecting a node where we start reclaim from. Because what we need is just
1947 * reducing usage counter, start from anywhere is O,K. Considering
1948 * memory reclaim from current node, there are pros. and cons.
1950 * Freeing memory from current node means freeing memory from a node which
1951 * we'll use or we've used. So, it may make LRU bad. And if several threads
1952 * hit limits, it will see a contention on a node. But freeing from remote
1953 * node means more costs for memory reclaim because of memory latency.
1955 * Now, we use round-robin. Better algorithm is welcomed.
1957 int mem_cgroup_select_victim_node(struct mem_cgroup
*memcg
)
1961 mem_cgroup_may_update_nodemask(memcg
);
1962 node
= memcg
->last_scanned_node
;
1964 node
= next_node(node
, memcg
->scan_nodes
);
1965 if (node
== MAX_NUMNODES
)
1966 node
= first_node(memcg
->scan_nodes
);
1968 * We call this when we hit limit, not when pages are added to LRU.
1969 * No LRU may hold pages because all pages are UNEVICTABLE or
1970 * memcg is too small and all pages are not on LRU. In that case,
1971 * we use curret node.
1973 if (unlikely(node
== MAX_NUMNODES
))
1974 node
= numa_node_id();
1976 memcg
->last_scanned_node
= node
;
1981 * Check all nodes whether it contains reclaimable pages or not.
1982 * For quick scan, we make use of scan_nodes. This will allow us to skip
1983 * unused nodes. But scan_nodes is lazily updated and may not cotain
1984 * enough new information. We need to do double check.
1986 static bool mem_cgroup_reclaimable(struct mem_cgroup
*memcg
, bool noswap
)
1991 * quick check...making use of scan_node.
1992 * We can skip unused nodes.
1994 if (!nodes_empty(memcg
->scan_nodes
)) {
1995 for (nid
= first_node(memcg
->scan_nodes
);
1997 nid
= next_node(nid
, memcg
->scan_nodes
)) {
1999 if (test_mem_cgroup_node_reclaimable(memcg
, nid
, noswap
))
2004 * Check rest of nodes.
2006 for_each_node_state(nid
, N_MEMORY
) {
2007 if (node_isset(nid
, memcg
->scan_nodes
))
2009 if (test_mem_cgroup_node_reclaimable(memcg
, nid
, noswap
))
2016 int mem_cgroup_select_victim_node(struct mem_cgroup
*memcg
)
2021 static bool mem_cgroup_reclaimable(struct mem_cgroup
*memcg
, bool noswap
)
2023 return test_mem_cgroup_node_reclaimable(memcg
, 0, noswap
);
2027 static int mem_cgroup_soft_reclaim(struct mem_cgroup
*root_memcg
,
2030 unsigned long *total_scanned
)
2032 struct mem_cgroup
*victim
= NULL
;
2035 unsigned long excess
;
2036 unsigned long nr_scanned
;
2037 struct mem_cgroup_reclaim_cookie reclaim
= {
2042 excess
= res_counter_soft_limit_excess(&root_memcg
->res
) >> PAGE_SHIFT
;
2045 victim
= mem_cgroup_iter(root_memcg
, victim
, &reclaim
);
2050 * If we have not been able to reclaim
2051 * anything, it might because there are
2052 * no reclaimable pages under this hierarchy
2057 * We want to do more targeted reclaim.
2058 * excess >> 2 is not to excessive so as to
2059 * reclaim too much, nor too less that we keep
2060 * coming back to reclaim from this cgroup
2062 if (total
>= (excess
>> 2) ||
2063 (loop
> MEM_CGROUP_MAX_RECLAIM_LOOPS
))
2068 if (!mem_cgroup_reclaimable(victim
, false))
2070 total
+= mem_cgroup_shrink_node_zone(victim
, gfp_mask
, false,
2072 *total_scanned
+= nr_scanned
;
2073 if (!res_counter_soft_limit_excess(&root_memcg
->res
))
2076 mem_cgroup_iter_break(root_memcg
, victim
);
2081 * Check OOM-Killer is already running under our hierarchy.
2082 * If someone is running, return false.
2083 * Has to be called with memcg_oom_lock
2085 static bool mem_cgroup_oom_lock(struct mem_cgroup
*memcg
)
2087 struct mem_cgroup
*iter
, *failed
= NULL
;
2089 for_each_mem_cgroup_tree(iter
, memcg
) {
2090 if (iter
->oom_lock
) {
2092 * this subtree of our hierarchy is already locked
2093 * so we cannot give a lock.
2096 mem_cgroup_iter_break(memcg
, iter
);
2099 iter
->oom_lock
= true;
2106 * OK, we failed to lock the whole subtree so we have to clean up
2107 * what we set up to the failing subtree
2109 for_each_mem_cgroup_tree(iter
, memcg
) {
2110 if (iter
== failed
) {
2111 mem_cgroup_iter_break(memcg
, iter
);
2114 iter
->oom_lock
= false;
2120 * Has to be called with memcg_oom_lock
2122 static int mem_cgroup_oom_unlock(struct mem_cgroup
*memcg
)
2124 struct mem_cgroup
*iter
;
2126 for_each_mem_cgroup_tree(iter
, memcg
)
2127 iter
->oom_lock
= false;
2131 static void mem_cgroup_mark_under_oom(struct mem_cgroup
*memcg
)
2133 struct mem_cgroup
*iter
;
2135 for_each_mem_cgroup_tree(iter
, memcg
)
2136 atomic_inc(&iter
->under_oom
);
2139 static void mem_cgroup_unmark_under_oom(struct mem_cgroup
*memcg
)
2141 struct mem_cgroup
*iter
;
2144 * When a new child is created while the hierarchy is under oom,
2145 * mem_cgroup_oom_lock() may not be called. We have to use
2146 * atomic_add_unless() here.
2148 for_each_mem_cgroup_tree(iter
, memcg
)
2149 atomic_add_unless(&iter
->under_oom
, -1, 0);
2152 static DEFINE_SPINLOCK(memcg_oom_lock
);
2153 static DECLARE_WAIT_QUEUE_HEAD(memcg_oom_waitq
);
2155 struct oom_wait_info
{
2156 struct mem_cgroup
*memcg
;
2160 static int memcg_oom_wake_function(wait_queue_t
*wait
,
2161 unsigned mode
, int sync
, void *arg
)
2163 struct mem_cgroup
*wake_memcg
= (struct mem_cgroup
*)arg
;
2164 struct mem_cgroup
*oom_wait_memcg
;
2165 struct oom_wait_info
*oom_wait_info
;
2167 oom_wait_info
= container_of(wait
, struct oom_wait_info
, wait
);
2168 oom_wait_memcg
= oom_wait_info
->memcg
;
2171 * Both of oom_wait_info->memcg and wake_memcg are stable under us.
2172 * Then we can use css_is_ancestor without taking care of RCU.
2174 if (!mem_cgroup_same_or_subtree(oom_wait_memcg
, wake_memcg
)
2175 && !mem_cgroup_same_or_subtree(wake_memcg
, oom_wait_memcg
))
2177 return autoremove_wake_function(wait
, mode
, sync
, arg
);
2180 static void memcg_wakeup_oom(struct mem_cgroup
*memcg
)
2182 /* for filtering, pass "memcg" as argument. */
2183 __wake_up(&memcg_oom_waitq
, TASK_NORMAL
, 0, memcg
);
2186 static void memcg_oom_recover(struct mem_cgroup
*memcg
)
2188 if (memcg
&& atomic_read(&memcg
->under_oom
))
2189 memcg_wakeup_oom(memcg
);
2193 * try to call OOM killer. returns false if we should exit memory-reclaim loop.
2195 static bool mem_cgroup_handle_oom(struct mem_cgroup
*memcg
, gfp_t mask
,
2198 struct oom_wait_info owait
;
2199 bool locked
, need_to_kill
;
2201 owait
.memcg
= memcg
;
2202 owait
.wait
.flags
= 0;
2203 owait
.wait
.func
= memcg_oom_wake_function
;
2204 owait
.wait
.private = current
;
2205 INIT_LIST_HEAD(&owait
.wait
.task_list
);
2206 need_to_kill
= true;
2207 mem_cgroup_mark_under_oom(memcg
);
2209 /* At first, try to OOM lock hierarchy under memcg.*/
2210 spin_lock(&memcg_oom_lock
);
2211 locked
= mem_cgroup_oom_lock(memcg
);
2213 * Even if signal_pending(), we can't quit charge() loop without
2214 * accounting. So, UNINTERRUPTIBLE is appropriate. But SIGKILL
2215 * under OOM is always welcomed, use TASK_KILLABLE here.
2217 prepare_to_wait(&memcg_oom_waitq
, &owait
.wait
, TASK_KILLABLE
);
2218 if (!locked
|| memcg
->oom_kill_disable
)
2219 need_to_kill
= false;
2221 mem_cgroup_oom_notify(memcg
);
2222 spin_unlock(&memcg_oom_lock
);
2225 finish_wait(&memcg_oom_waitq
, &owait
.wait
);
2226 mem_cgroup_out_of_memory(memcg
, mask
, order
);
2229 finish_wait(&memcg_oom_waitq
, &owait
.wait
);
2231 spin_lock(&memcg_oom_lock
);
2233 mem_cgroup_oom_unlock(memcg
);
2234 memcg_wakeup_oom(memcg
);
2235 spin_unlock(&memcg_oom_lock
);
2237 mem_cgroup_unmark_under_oom(memcg
);
2239 if (test_thread_flag(TIF_MEMDIE
) || fatal_signal_pending(current
))
2241 /* Give chance to dying process */
2242 schedule_timeout_uninterruptible(1);
2247 * Currently used to update mapped file statistics, but the routine can be
2248 * generalized to update other statistics as well.
2250 * Notes: Race condition
2252 * We usually use page_cgroup_lock() for accessing page_cgroup member but
2253 * it tends to be costly. But considering some conditions, we doesn't need
2254 * to do so _always_.
2256 * Considering "charge", lock_page_cgroup() is not required because all
2257 * file-stat operations happen after a page is attached to radix-tree. There
2258 * are no race with "charge".
2260 * Considering "uncharge", we know that memcg doesn't clear pc->mem_cgroup
2261 * at "uncharge" intentionally. So, we always see valid pc->mem_cgroup even
2262 * if there are race with "uncharge". Statistics itself is properly handled
2265 * Considering "move", this is an only case we see a race. To make the race
2266 * small, we check mm->moving_account and detect there are possibility of race
2267 * If there is, we take a lock.
2270 void __mem_cgroup_begin_update_page_stat(struct page
*page
,
2271 bool *locked
, unsigned long *flags
)
2273 struct mem_cgroup
*memcg
;
2274 struct page_cgroup
*pc
;
2276 pc
= lookup_page_cgroup(page
);
2278 memcg
= pc
->mem_cgroup
;
2279 if (unlikely(!memcg
|| !PageCgroupUsed(pc
)))
2282 * If this memory cgroup is not under account moving, we don't
2283 * need to take move_lock_mem_cgroup(). Because we already hold
2284 * rcu_read_lock(), any calls to move_account will be delayed until
2285 * rcu_read_unlock() if mem_cgroup_stolen() == true.
2287 if (!mem_cgroup_stolen(memcg
))
2290 move_lock_mem_cgroup(memcg
, flags
);
2291 if (memcg
!= pc
->mem_cgroup
|| !PageCgroupUsed(pc
)) {
2292 move_unlock_mem_cgroup(memcg
, flags
);
2298 void __mem_cgroup_end_update_page_stat(struct page
*page
, unsigned long *flags
)
2300 struct page_cgroup
*pc
= lookup_page_cgroup(page
);
2303 * It's guaranteed that pc->mem_cgroup never changes while
2304 * lock is held because a routine modifies pc->mem_cgroup
2305 * should take move_lock_mem_cgroup().
2307 move_unlock_mem_cgroup(pc
->mem_cgroup
, flags
);
2310 void mem_cgroup_update_page_stat(struct page
*page
,
2311 enum mem_cgroup_page_stat_item idx
, int val
)
2313 struct mem_cgroup
*memcg
;
2314 struct page_cgroup
*pc
= lookup_page_cgroup(page
);
2315 unsigned long uninitialized_var(flags
);
2317 if (mem_cgroup_disabled())
2320 memcg
= pc
->mem_cgroup
;
2321 if (unlikely(!memcg
|| !PageCgroupUsed(pc
)))
2325 case MEMCG_NR_FILE_MAPPED
:
2326 idx
= MEM_CGROUP_STAT_FILE_MAPPED
;
2332 this_cpu_add(memcg
->stat
->count
[idx
], val
);
2336 * size of first charge trial. "32" comes from vmscan.c's magic value.
2337 * TODO: maybe necessary to use big numbers in big irons.
2339 #define CHARGE_BATCH 32U
2340 struct memcg_stock_pcp
{
2341 struct mem_cgroup
*cached
; /* this never be root cgroup */
2342 unsigned int nr_pages
;
2343 struct work_struct work
;
2344 unsigned long flags
;
2345 #define FLUSHING_CACHED_CHARGE 0
2347 static DEFINE_PER_CPU(struct memcg_stock_pcp
, memcg_stock
);
2348 static DEFINE_MUTEX(percpu_charge_mutex
);
2351 * consume_stock: Try to consume stocked charge on this cpu.
2352 * @memcg: memcg to consume from.
2353 * @nr_pages: how many pages to charge.
2355 * The charges will only happen if @memcg matches the current cpu's memcg
2356 * stock, and at least @nr_pages are available in that stock. Failure to
2357 * service an allocation will refill the stock.
2359 * returns true if successful, false otherwise.
2361 static bool consume_stock(struct mem_cgroup
*memcg
, unsigned int nr_pages
)
2363 struct memcg_stock_pcp
*stock
;
2366 if (nr_pages
> CHARGE_BATCH
)
2369 stock
= &get_cpu_var(memcg_stock
);
2370 if (memcg
== stock
->cached
&& stock
->nr_pages
>= nr_pages
)
2371 stock
->nr_pages
-= nr_pages
;
2372 else /* need to call res_counter_charge */
2374 put_cpu_var(memcg_stock
);
2379 * Returns stocks cached in percpu to res_counter and reset cached information.
2381 static void drain_stock(struct memcg_stock_pcp
*stock
)
2383 struct mem_cgroup
*old
= stock
->cached
;
2385 if (stock
->nr_pages
) {
2386 unsigned long bytes
= stock
->nr_pages
* PAGE_SIZE
;
2388 res_counter_uncharge(&old
->res
, bytes
);
2389 if (do_swap_account
)
2390 res_counter_uncharge(&old
->memsw
, bytes
);
2391 stock
->nr_pages
= 0;
2393 stock
->cached
= NULL
;
2397 * This must be called under preempt disabled or must be called by
2398 * a thread which is pinned to local cpu.
2400 static void drain_local_stock(struct work_struct
*dummy
)
2402 struct memcg_stock_pcp
*stock
= &__get_cpu_var(memcg_stock
);
2404 clear_bit(FLUSHING_CACHED_CHARGE
, &stock
->flags
);
2407 static void __init
memcg_stock_init(void)
2411 for_each_possible_cpu(cpu
) {
2412 struct memcg_stock_pcp
*stock
=
2413 &per_cpu(memcg_stock
, cpu
);
2414 INIT_WORK(&stock
->work
, drain_local_stock
);
2419 * Cache charges(val) which is from res_counter, to local per_cpu area.
2420 * This will be consumed by consume_stock() function, later.
2422 static void refill_stock(struct mem_cgroup
*memcg
, unsigned int nr_pages
)
2424 struct memcg_stock_pcp
*stock
= &get_cpu_var(memcg_stock
);
2426 if (stock
->cached
!= memcg
) { /* reset if necessary */
2428 stock
->cached
= memcg
;
2430 stock
->nr_pages
+= nr_pages
;
2431 put_cpu_var(memcg_stock
);
2435 * Drains all per-CPU charge caches for given root_memcg resp. subtree
2436 * of the hierarchy under it. sync flag says whether we should block
2437 * until the work is done.
2439 static void drain_all_stock(struct mem_cgroup
*root_memcg
, bool sync
)
2443 /* Notify other cpus that system-wide "drain" is running */
2446 for_each_online_cpu(cpu
) {
2447 struct memcg_stock_pcp
*stock
= &per_cpu(memcg_stock
, cpu
);
2448 struct mem_cgroup
*memcg
;
2450 memcg
= stock
->cached
;
2451 if (!memcg
|| !stock
->nr_pages
)
2453 if (!mem_cgroup_same_or_subtree(root_memcg
, memcg
))
2455 if (!test_and_set_bit(FLUSHING_CACHED_CHARGE
, &stock
->flags
)) {
2457 drain_local_stock(&stock
->work
);
2459 schedule_work_on(cpu
, &stock
->work
);
2467 for_each_online_cpu(cpu
) {
2468 struct memcg_stock_pcp
*stock
= &per_cpu(memcg_stock
, cpu
);
2469 if (test_bit(FLUSHING_CACHED_CHARGE
, &stock
->flags
))
2470 flush_work(&stock
->work
);
2477 * Tries to drain stocked charges in other cpus. This function is asynchronous
2478 * and just put a work per cpu for draining localy on each cpu. Caller can
2479 * expects some charges will be back to res_counter later but cannot wait for
2482 static void drain_all_stock_async(struct mem_cgroup
*root_memcg
)
2485 * If someone calls draining, avoid adding more kworker runs.
2487 if (!mutex_trylock(&percpu_charge_mutex
))
2489 drain_all_stock(root_memcg
, false);
2490 mutex_unlock(&percpu_charge_mutex
);
2493 /* This is a synchronous drain interface. */
2494 static void drain_all_stock_sync(struct mem_cgroup
*root_memcg
)
2496 /* called when force_empty is called */
2497 mutex_lock(&percpu_charge_mutex
);
2498 drain_all_stock(root_memcg
, true);
2499 mutex_unlock(&percpu_charge_mutex
);
2503 * This function drains percpu counter value from DEAD cpu and
2504 * move it to local cpu. Note that this function can be preempted.
2506 static void mem_cgroup_drain_pcp_counter(struct mem_cgroup
*memcg
, int cpu
)
2510 spin_lock(&memcg
->pcp_counter_lock
);
2511 for (i
= 0; i
< MEM_CGROUP_STAT_NSTATS
; i
++) {
2512 long x
= per_cpu(memcg
->stat
->count
[i
], cpu
);
2514 per_cpu(memcg
->stat
->count
[i
], cpu
) = 0;
2515 memcg
->nocpu_base
.count
[i
] += x
;
2517 for (i
= 0; i
< MEM_CGROUP_EVENTS_NSTATS
; i
++) {
2518 unsigned long x
= per_cpu(memcg
->stat
->events
[i
], cpu
);
2520 per_cpu(memcg
->stat
->events
[i
], cpu
) = 0;
2521 memcg
->nocpu_base
.events
[i
] += x
;
2523 spin_unlock(&memcg
->pcp_counter_lock
);
2526 static int __cpuinit
memcg_cpu_hotplug_callback(struct notifier_block
*nb
,
2527 unsigned long action
,
2530 int cpu
= (unsigned long)hcpu
;
2531 struct memcg_stock_pcp
*stock
;
2532 struct mem_cgroup
*iter
;
2534 if (action
== CPU_ONLINE
)
2537 if (action
!= CPU_DEAD
&& action
!= CPU_DEAD_FROZEN
)
2540 for_each_mem_cgroup(iter
)
2541 mem_cgroup_drain_pcp_counter(iter
, cpu
);
2543 stock
= &per_cpu(memcg_stock
, cpu
);
2549 /* See __mem_cgroup_try_charge() for details */
2551 CHARGE_OK
, /* success */
2552 CHARGE_RETRY
, /* need to retry but retry is not bad */
2553 CHARGE_NOMEM
, /* we can't do more. return -ENOMEM */
2554 CHARGE_WOULDBLOCK
, /* GFP_WAIT wasn't set and no enough res. */
2555 CHARGE_OOM_DIE
, /* the current is killed because of OOM */
2558 static int mem_cgroup_do_charge(struct mem_cgroup
*memcg
, gfp_t gfp_mask
,
2559 unsigned int nr_pages
, unsigned int min_pages
,
2562 unsigned long csize
= nr_pages
* PAGE_SIZE
;
2563 struct mem_cgroup
*mem_over_limit
;
2564 struct res_counter
*fail_res
;
2565 unsigned long flags
= 0;
2568 ret
= res_counter_charge(&memcg
->res
, csize
, &fail_res
);
2571 if (!do_swap_account
)
2573 ret
= res_counter_charge(&memcg
->memsw
, csize
, &fail_res
);
2577 res_counter_uncharge(&memcg
->res
, csize
);
2578 mem_over_limit
= mem_cgroup_from_res_counter(fail_res
, memsw
);
2579 flags
|= MEM_CGROUP_RECLAIM_NOSWAP
;
2581 mem_over_limit
= mem_cgroup_from_res_counter(fail_res
, res
);
2583 * Never reclaim on behalf of optional batching, retry with a
2584 * single page instead.
2586 if (nr_pages
> min_pages
)
2587 return CHARGE_RETRY
;
2589 if (!(gfp_mask
& __GFP_WAIT
))
2590 return CHARGE_WOULDBLOCK
;
2592 if (gfp_mask
& __GFP_NORETRY
)
2593 return CHARGE_NOMEM
;
2595 ret
= mem_cgroup_reclaim(mem_over_limit
, gfp_mask
, flags
);
2596 if (mem_cgroup_margin(mem_over_limit
) >= nr_pages
)
2597 return CHARGE_RETRY
;
2599 * Even though the limit is exceeded at this point, reclaim
2600 * may have been able to free some pages. Retry the charge
2601 * before killing the task.
2603 * Only for regular pages, though: huge pages are rather
2604 * unlikely to succeed so close to the limit, and we fall back
2605 * to regular pages anyway in case of failure.
2607 if (nr_pages
<= (1 << PAGE_ALLOC_COSTLY_ORDER
) && ret
)
2608 return CHARGE_RETRY
;
2611 * At task move, charge accounts can be doubly counted. So, it's
2612 * better to wait until the end of task_move if something is going on.
2614 if (mem_cgroup_wait_acct_move(mem_over_limit
))
2615 return CHARGE_RETRY
;
2617 /* If we don't need to call oom-killer at el, return immediately */
2619 return CHARGE_NOMEM
;
2621 if (!mem_cgroup_handle_oom(mem_over_limit
, gfp_mask
, get_order(csize
)))
2622 return CHARGE_OOM_DIE
;
2624 return CHARGE_RETRY
;
2628 * __mem_cgroup_try_charge() does
2629 * 1. detect memcg to be charged against from passed *mm and *ptr,
2630 * 2. update res_counter
2631 * 3. call memory reclaim if necessary.
2633 * In some special case, if the task is fatal, fatal_signal_pending() or
2634 * has TIF_MEMDIE, this function returns -EINTR while writing root_mem_cgroup
2635 * to *ptr. There are two reasons for this. 1: fatal threads should quit as soon
2636 * as possible without any hazards. 2: all pages should have a valid
2637 * pc->mem_cgroup. If mm is NULL and the caller doesn't pass a valid memcg
2638 * pointer, that is treated as a charge to root_mem_cgroup.
2640 * So __mem_cgroup_try_charge() will return
2641 * 0 ... on success, filling *ptr with a valid memcg pointer.
2642 * -ENOMEM ... charge failure because of resource limits.
2643 * -EINTR ... if thread is fatal. *ptr is filled with root_mem_cgroup.
2645 * Unlike the exported interface, an "oom" parameter is added. if oom==true,
2646 * the oom-killer can be invoked.
2648 static int __mem_cgroup_try_charge(struct mm_struct
*mm
,
2650 unsigned int nr_pages
,
2651 struct mem_cgroup
**ptr
,
2654 unsigned int batch
= max(CHARGE_BATCH
, nr_pages
);
2655 int nr_oom_retries
= MEM_CGROUP_RECLAIM_RETRIES
;
2656 struct mem_cgroup
*memcg
= NULL
;
2660 * Unlike gloval-vm's OOM-kill, we're not in memory shortage
2661 * in system level. So, allow to go ahead dying process in addition to
2664 if (unlikely(test_thread_flag(TIF_MEMDIE
)
2665 || fatal_signal_pending(current
)))
2669 * We always charge the cgroup the mm_struct belongs to.
2670 * The mm_struct's mem_cgroup changes on task migration if the
2671 * thread group leader migrates. It's possible that mm is not
2672 * set, if so charge the root memcg (happens for pagecache usage).
2675 *ptr
= root_mem_cgroup
;
2677 if (*ptr
) { /* css should be a valid one */
2679 if (mem_cgroup_is_root(memcg
))
2681 if (consume_stock(memcg
, nr_pages
))
2683 css_get(&memcg
->css
);
2685 struct task_struct
*p
;
2688 p
= rcu_dereference(mm
->owner
);
2690 * Because we don't have task_lock(), "p" can exit.
2691 * In that case, "memcg" can point to root or p can be NULL with
2692 * race with swapoff. Then, we have small risk of mis-accouning.
2693 * But such kind of mis-account by race always happens because
2694 * we don't have cgroup_mutex(). It's overkill and we allo that
2696 * (*) swapoff at el will charge against mm-struct not against
2697 * task-struct. So, mm->owner can be NULL.
2699 memcg
= mem_cgroup_from_task(p
);
2701 memcg
= root_mem_cgroup
;
2702 if (mem_cgroup_is_root(memcg
)) {
2706 if (consume_stock(memcg
, nr_pages
)) {
2708 * It seems dagerous to access memcg without css_get().
2709 * But considering how consume_stok works, it's not
2710 * necessary. If consume_stock success, some charges
2711 * from this memcg are cached on this cpu. So, we
2712 * don't need to call css_get()/css_tryget() before
2713 * calling consume_stock().
2718 /* after here, we may be blocked. we need to get refcnt */
2719 if (!css_tryget(&memcg
->css
)) {
2729 /* If killed, bypass charge */
2730 if (fatal_signal_pending(current
)) {
2731 css_put(&memcg
->css
);
2736 if (oom
&& !nr_oom_retries
) {
2738 nr_oom_retries
= MEM_CGROUP_RECLAIM_RETRIES
;
2741 ret
= mem_cgroup_do_charge(memcg
, gfp_mask
, batch
, nr_pages
,
2746 case CHARGE_RETRY
: /* not in OOM situation but retry */
2748 css_put(&memcg
->css
);
2751 case CHARGE_WOULDBLOCK
: /* !__GFP_WAIT */
2752 css_put(&memcg
->css
);
2754 case CHARGE_NOMEM
: /* OOM routine works */
2756 css_put(&memcg
->css
);
2759 /* If oom, we never return -ENOMEM */
2762 case CHARGE_OOM_DIE
: /* Killed by OOM Killer */
2763 css_put(&memcg
->css
);
2766 } while (ret
!= CHARGE_OK
);
2768 if (batch
> nr_pages
)
2769 refill_stock(memcg
, batch
- nr_pages
);
2770 css_put(&memcg
->css
);
2778 *ptr
= root_mem_cgroup
;
2783 * Somemtimes we have to undo a charge we got by try_charge().
2784 * This function is for that and do uncharge, put css's refcnt.
2785 * gotten by try_charge().
2787 static void __mem_cgroup_cancel_charge(struct mem_cgroup
*memcg
,
2788 unsigned int nr_pages
)
2790 if (!mem_cgroup_is_root(memcg
)) {
2791 unsigned long bytes
= nr_pages
* PAGE_SIZE
;
2793 res_counter_uncharge(&memcg
->res
, bytes
);
2794 if (do_swap_account
)
2795 res_counter_uncharge(&memcg
->memsw
, bytes
);
2800 * Cancel chrages in this cgroup....doesn't propagate to parent cgroup.
2801 * This is useful when moving usage to parent cgroup.
2803 static void __mem_cgroup_cancel_local_charge(struct mem_cgroup
*memcg
,
2804 unsigned int nr_pages
)
2806 unsigned long bytes
= nr_pages
* PAGE_SIZE
;
2808 if (mem_cgroup_is_root(memcg
))
2811 res_counter_uncharge_until(&memcg
->res
, memcg
->res
.parent
, bytes
);
2812 if (do_swap_account
)
2813 res_counter_uncharge_until(&memcg
->memsw
,
2814 memcg
->memsw
.parent
, bytes
);
2818 * A helper function to get mem_cgroup from ID. must be called under
2819 * rcu_read_lock(). The caller is responsible for calling css_tryget if
2820 * the mem_cgroup is used for charging. (dropping refcnt from swap can be
2821 * called against removed memcg.)
2823 static struct mem_cgroup
*mem_cgroup_lookup(unsigned short id
)
2825 struct cgroup_subsys_state
*css
;
2827 /* ID 0 is unused ID */
2830 css
= css_lookup(&mem_cgroup_subsys
, id
);
2833 return mem_cgroup_from_css(css
);
2836 struct mem_cgroup
*try_get_mem_cgroup_from_page(struct page
*page
)
2838 struct mem_cgroup
*memcg
= NULL
;
2839 struct page_cgroup
*pc
;
2843 VM_BUG_ON(!PageLocked(page
));
2845 pc
= lookup_page_cgroup(page
);
2846 lock_page_cgroup(pc
);
2847 if (PageCgroupUsed(pc
)) {
2848 memcg
= pc
->mem_cgroup
;
2849 if (memcg
&& !css_tryget(&memcg
->css
))
2851 } else if (PageSwapCache(page
)) {
2852 ent
.val
= page_private(page
);
2853 id
= lookup_swap_cgroup_id(ent
);
2855 memcg
= mem_cgroup_lookup(id
);
2856 if (memcg
&& !css_tryget(&memcg
->css
))
2860 unlock_page_cgroup(pc
);
2864 static void __mem_cgroup_commit_charge(struct mem_cgroup
*memcg
,
2866 unsigned int nr_pages
,
2867 enum charge_type ctype
,
2870 struct page_cgroup
*pc
= lookup_page_cgroup(page
);
2871 struct zone
*uninitialized_var(zone
);
2872 struct lruvec
*lruvec
;
2873 bool was_on_lru
= false;
2876 lock_page_cgroup(pc
);
2877 VM_BUG_ON(PageCgroupUsed(pc
));
2879 * we don't need page_cgroup_lock about tail pages, becase they are not
2880 * accessed by any other context at this point.
2884 * In some cases, SwapCache and FUSE(splice_buf->radixtree), the page
2885 * may already be on some other mem_cgroup's LRU. Take care of it.
2888 zone
= page_zone(page
);
2889 spin_lock_irq(&zone
->lru_lock
);
2890 if (PageLRU(page
)) {
2891 lruvec
= mem_cgroup_zone_lruvec(zone
, pc
->mem_cgroup
);
2893 del_page_from_lru_list(page
, lruvec
, page_lru(page
));
2898 pc
->mem_cgroup
= memcg
;
2900 * We access a page_cgroup asynchronously without lock_page_cgroup().
2901 * Especially when a page_cgroup is taken from a page, pc->mem_cgroup
2902 * is accessed after testing USED bit. To make pc->mem_cgroup visible
2903 * before USED bit, we need memory barrier here.
2904 * See mem_cgroup_add_lru_list(), etc.
2907 SetPageCgroupUsed(pc
);
2911 lruvec
= mem_cgroup_zone_lruvec(zone
, pc
->mem_cgroup
);
2912 VM_BUG_ON(PageLRU(page
));
2914 add_page_to_lru_list(page
, lruvec
, page_lru(page
));
2916 spin_unlock_irq(&zone
->lru_lock
);
2919 if (ctype
== MEM_CGROUP_CHARGE_TYPE_ANON
)
2924 mem_cgroup_charge_statistics(memcg
, page
, anon
, nr_pages
);
2925 unlock_page_cgroup(pc
);
2928 * "charge_statistics" updated event counter. Then, check it.
2929 * Insert ancestor (and ancestor's ancestors), to softlimit RB-tree.
2930 * if they exceeds softlimit.
2932 memcg_check_events(memcg
, page
);
2935 static DEFINE_MUTEX(set_limit_mutex
);
2937 #ifdef CONFIG_MEMCG_KMEM
2938 static inline bool memcg_can_account_kmem(struct mem_cgroup
*memcg
)
2940 return !mem_cgroup_disabled() && !mem_cgroup_is_root(memcg
) &&
2941 (memcg
->kmem_account_flags
& KMEM_ACCOUNTED_MASK
);
2945 * This is a bit cumbersome, but it is rarely used and avoids a backpointer
2946 * in the memcg_cache_params struct.
2948 static struct kmem_cache
*memcg_params_to_cache(struct memcg_cache_params
*p
)
2950 struct kmem_cache
*cachep
;
2952 VM_BUG_ON(p
->is_root_cache
);
2953 cachep
= p
->root_cache
;
2954 return cachep
->memcg_params
->memcg_caches
[memcg_cache_id(p
->memcg
)];
2957 #ifdef CONFIG_SLABINFO
2958 static int mem_cgroup_slabinfo_read(struct cgroup
*cont
, struct cftype
*cft
,
2961 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cont
);
2962 struct memcg_cache_params
*params
;
2964 if (!memcg_can_account_kmem(memcg
))
2967 print_slabinfo_header(m
);
2969 mutex_lock(&memcg
->slab_caches_mutex
);
2970 list_for_each_entry(params
, &memcg
->memcg_slab_caches
, list
)
2971 cache_show(memcg_params_to_cache(params
), m
);
2972 mutex_unlock(&memcg
->slab_caches_mutex
);
2978 static int memcg_charge_kmem(struct mem_cgroup
*memcg
, gfp_t gfp
, u64 size
)
2980 struct res_counter
*fail_res
;
2981 struct mem_cgroup
*_memcg
;
2985 ret
= res_counter_charge(&memcg
->kmem
, size
, &fail_res
);
2990 * Conditions under which we can wait for the oom_killer. Those are
2991 * the same conditions tested by the core page allocator
2993 may_oom
= (gfp
& __GFP_FS
) && !(gfp
& __GFP_NORETRY
);
2996 ret
= __mem_cgroup_try_charge(NULL
, gfp
, size
>> PAGE_SHIFT
,
2999 if (ret
== -EINTR
) {
3001 * __mem_cgroup_try_charge() chosed to bypass to root due to
3002 * OOM kill or fatal signal. Since our only options are to
3003 * either fail the allocation or charge it to this cgroup, do
3004 * it as a temporary condition. But we can't fail. From a
3005 * kmem/slab perspective, the cache has already been selected,
3006 * by mem_cgroup_kmem_get_cache(), so it is too late to change
3009 * This condition will only trigger if the task entered
3010 * memcg_charge_kmem in a sane state, but was OOM-killed during
3011 * __mem_cgroup_try_charge() above. Tasks that were already
3012 * dying when the allocation triggers should have been already
3013 * directed to the root cgroup in memcontrol.h
3015 res_counter_charge_nofail(&memcg
->res
, size
, &fail_res
);
3016 if (do_swap_account
)
3017 res_counter_charge_nofail(&memcg
->memsw
, size
,
3021 res_counter_uncharge(&memcg
->kmem
, size
);
3026 static void memcg_uncharge_kmem(struct mem_cgroup
*memcg
, u64 size
)
3028 res_counter_uncharge(&memcg
->res
, size
);
3029 if (do_swap_account
)
3030 res_counter_uncharge(&memcg
->memsw
, size
);
3033 if (res_counter_uncharge(&memcg
->kmem
, size
))
3036 if (memcg_kmem_test_and_clear_dead(memcg
))
3037 mem_cgroup_put(memcg
);
3040 void memcg_cache_list_add(struct mem_cgroup
*memcg
, struct kmem_cache
*cachep
)
3045 mutex_lock(&memcg
->slab_caches_mutex
);
3046 list_add(&cachep
->memcg_params
->list
, &memcg
->memcg_slab_caches
);
3047 mutex_unlock(&memcg
->slab_caches_mutex
);
3051 * helper for acessing a memcg's index. It will be used as an index in the
3052 * child cache array in kmem_cache, and also to derive its name. This function
3053 * will return -1 when this is not a kmem-limited memcg.
3055 int memcg_cache_id(struct mem_cgroup
*memcg
)
3057 return memcg
? memcg
->kmemcg_id
: -1;
3061 * This ends up being protected by the set_limit mutex, during normal
3062 * operation, because that is its main call site.
3064 * But when we create a new cache, we can call this as well if its parent
3065 * is kmem-limited. That will have to hold set_limit_mutex as well.
3067 int memcg_update_cache_sizes(struct mem_cgroup
*memcg
)
3071 num
= ida_simple_get(&kmem_limited_groups
,
3072 0, MEMCG_CACHES_MAX_SIZE
, GFP_KERNEL
);
3076 * After this point, kmem_accounted (that we test atomically in
3077 * the beginning of this conditional), is no longer 0. This
3078 * guarantees only one process will set the following boolean
3079 * to true. We don't need test_and_set because we're protected
3080 * by the set_limit_mutex anyway.
3082 memcg_kmem_set_activated(memcg
);
3084 ret
= memcg_update_all_caches(num
+1);
3086 ida_simple_remove(&kmem_limited_groups
, num
);
3087 memcg_kmem_clear_activated(memcg
);
3091 memcg
->kmemcg_id
= num
;
3092 INIT_LIST_HEAD(&memcg
->memcg_slab_caches
);
3093 mutex_init(&memcg
->slab_caches_mutex
);
3097 static size_t memcg_caches_array_size(int num_groups
)
3100 if (num_groups
<= 0)
3103 size
= 2 * num_groups
;
3104 if (size
< MEMCG_CACHES_MIN_SIZE
)
3105 size
= MEMCG_CACHES_MIN_SIZE
;
3106 else if (size
> MEMCG_CACHES_MAX_SIZE
)
3107 size
= MEMCG_CACHES_MAX_SIZE
;
3113 * We should update the current array size iff all caches updates succeed. This
3114 * can only be done from the slab side. The slab mutex needs to be held when
3117 void memcg_update_array_size(int num
)
3119 if (num
> memcg_limited_groups_array_size
)
3120 memcg_limited_groups_array_size
= memcg_caches_array_size(num
);
3123 static void kmem_cache_destroy_work_func(struct work_struct
*w
);
3125 int memcg_update_cache_size(struct kmem_cache
*s
, int num_groups
)
3127 struct memcg_cache_params
*cur_params
= s
->memcg_params
;
3129 VM_BUG_ON(s
->memcg_params
&& !s
->memcg_params
->is_root_cache
);
3131 if (num_groups
> memcg_limited_groups_array_size
) {
3133 ssize_t size
= memcg_caches_array_size(num_groups
);
3135 size
*= sizeof(void *);
3136 size
+= sizeof(struct memcg_cache_params
);
3138 s
->memcg_params
= kzalloc(size
, GFP_KERNEL
);
3139 if (!s
->memcg_params
) {
3140 s
->memcg_params
= cur_params
;
3144 INIT_WORK(&s
->memcg_params
->destroy
,
3145 kmem_cache_destroy_work_func
);
3146 s
->memcg_params
->is_root_cache
= true;
3149 * There is the chance it will be bigger than
3150 * memcg_limited_groups_array_size, if we failed an allocation
3151 * in a cache, in which case all caches updated before it, will
3152 * have a bigger array.
3154 * But if that is the case, the data after
3155 * memcg_limited_groups_array_size is certainly unused
3157 for (i
= 0; i
< memcg_limited_groups_array_size
; i
++) {
3158 if (!cur_params
->memcg_caches
[i
])
3160 s
->memcg_params
->memcg_caches
[i
] =
3161 cur_params
->memcg_caches
[i
];
3165 * Ideally, we would wait until all caches succeed, and only
3166 * then free the old one. But this is not worth the extra
3167 * pointer per-cache we'd have to have for this.
3169 * It is not a big deal if some caches are left with a size
3170 * bigger than the others. And all updates will reset this
3178 int memcg_register_cache(struct mem_cgroup
*memcg
, struct kmem_cache
*s
,
3179 struct kmem_cache
*root_cache
)
3181 size_t size
= sizeof(struct memcg_cache_params
);
3183 if (!memcg_kmem_enabled())
3187 size
+= memcg_limited_groups_array_size
* sizeof(void *);
3189 s
->memcg_params
= kzalloc(size
, GFP_KERNEL
);
3190 if (!s
->memcg_params
)
3193 INIT_WORK(&s
->memcg_params
->destroy
,
3194 kmem_cache_destroy_work_func
);
3196 s
->memcg_params
->memcg
= memcg
;
3197 s
->memcg_params
->root_cache
= root_cache
;
3199 s
->memcg_params
->is_root_cache
= true;
3204 void memcg_release_cache(struct kmem_cache
*s
)
3206 struct kmem_cache
*root
;
3207 struct mem_cgroup
*memcg
;
3211 * This happens, for instance, when a root cache goes away before we
3214 if (!s
->memcg_params
)
3217 if (s
->memcg_params
->is_root_cache
)
3220 memcg
= s
->memcg_params
->memcg
;
3221 id
= memcg_cache_id(memcg
);
3223 root
= s
->memcg_params
->root_cache
;
3224 root
->memcg_params
->memcg_caches
[id
] = NULL
;
3226 mutex_lock(&memcg
->slab_caches_mutex
);
3227 list_del(&s
->memcg_params
->list
);
3228 mutex_unlock(&memcg
->slab_caches_mutex
);
3230 mem_cgroup_put(memcg
);
3232 kfree(s
->memcg_params
);
3236 * During the creation a new cache, we need to disable our accounting mechanism
3237 * altogether. This is true even if we are not creating, but rather just
3238 * enqueing new caches to be created.
3240 * This is because that process will trigger allocations; some visible, like
3241 * explicit kmallocs to auxiliary data structures, name strings and internal
3242 * cache structures; some well concealed, like INIT_WORK() that can allocate
3243 * objects during debug.
3245 * If any allocation happens during memcg_kmem_get_cache, we will recurse back
3246 * to it. This may not be a bounded recursion: since the first cache creation
3247 * failed to complete (waiting on the allocation), we'll just try to create the
3248 * cache again, failing at the same point.
3250 * memcg_kmem_get_cache is prepared to abort after seeing a positive count of
3251 * memcg_kmem_skip_account. So we enclose anything that might allocate memory
3252 * inside the following two functions.
3254 static inline void memcg_stop_kmem_account(void)
3256 VM_BUG_ON(!current
->mm
);
3257 current
->memcg_kmem_skip_account
++;
3260 static inline void memcg_resume_kmem_account(void)
3262 VM_BUG_ON(!current
->mm
);
3263 current
->memcg_kmem_skip_account
--;
3266 static void kmem_cache_destroy_work_func(struct work_struct
*w
)
3268 struct kmem_cache
*cachep
;
3269 struct memcg_cache_params
*p
;
3271 p
= container_of(w
, struct memcg_cache_params
, destroy
);
3273 cachep
= memcg_params_to_cache(p
);
3276 * If we get down to 0 after shrink, we could delete right away.
3277 * However, memcg_release_pages() already puts us back in the workqueue
3278 * in that case. If we proceed deleting, we'll get a dangling
3279 * reference, and removing the object from the workqueue in that case
3280 * is unnecessary complication. We are not a fast path.
3282 * Note that this case is fundamentally different from racing with
3283 * shrink_slab(): if memcg_cgroup_destroy_cache() is called in
3284 * kmem_cache_shrink, not only we would be reinserting a dead cache
3285 * into the queue, but doing so from inside the worker racing to
3288 * So if we aren't down to zero, we'll just schedule a worker and try
3291 if (atomic_read(&cachep
->memcg_params
->nr_pages
) != 0) {
3292 kmem_cache_shrink(cachep
);
3293 if (atomic_read(&cachep
->memcg_params
->nr_pages
) == 0)
3296 kmem_cache_destroy(cachep
);
3299 void mem_cgroup_destroy_cache(struct kmem_cache
*cachep
)
3301 if (!cachep
->memcg_params
->dead
)
3305 * There are many ways in which we can get here.
3307 * We can get to a memory-pressure situation while the delayed work is
3308 * still pending to run. The vmscan shrinkers can then release all
3309 * cache memory and get us to destruction. If this is the case, we'll
3310 * be executed twice, which is a bug (the second time will execute over
3311 * bogus data). In this case, cancelling the work should be fine.
3313 * But we can also get here from the worker itself, if
3314 * kmem_cache_shrink is enough to shake all the remaining objects and
3315 * get the page count to 0. In this case, we'll deadlock if we try to
3316 * cancel the work (the worker runs with an internal lock held, which
3317 * is the same lock we would hold for cancel_work_sync().)
3319 * Since we can't possibly know who got us here, just refrain from
3320 * running if there is already work pending
3322 if (work_pending(&cachep
->memcg_params
->destroy
))
3325 * We have to defer the actual destroying to a workqueue, because
3326 * we might currently be in a context that cannot sleep.
3328 schedule_work(&cachep
->memcg_params
->destroy
);
3332 * This lock protects updaters, not readers. We want readers to be as fast as
3333 * they can, and they will either see NULL or a valid cache value. Our model
3334 * allow them to see NULL, in which case the root memcg will be selected.
3336 * We need this lock because multiple allocations to the same cache from a non
3337 * will span more than one worker. Only one of them can create the cache.
3339 static DEFINE_MUTEX(memcg_cache_mutex
);
3342 * Called with memcg_cache_mutex held
3344 static struct kmem_cache
*kmem_cache_dup(struct mem_cgroup
*memcg
,
3345 struct kmem_cache
*s
)
3347 struct kmem_cache
*new;
3348 static char *tmp_name
= NULL
;
3350 lockdep_assert_held(&memcg_cache_mutex
);
3353 * kmem_cache_create_memcg duplicates the given name and
3354 * cgroup_name for this name requires RCU context.
3355 * This static temporary buffer is used to prevent from
3356 * pointless shortliving allocation.
3359 tmp_name
= kmalloc(PATH_MAX
, GFP_KERNEL
);
3365 snprintf(tmp_name
, PATH_MAX
, "%s(%d:%s)", s
->name
,
3366 memcg_cache_id(memcg
), cgroup_name(memcg
->css
.cgroup
));
3369 new = kmem_cache_create_memcg(memcg
, tmp_name
, s
->object_size
, s
->align
,
3370 (s
->flags
& ~SLAB_PANIC
), s
->ctor
, s
);
3373 new->allocflags
|= __GFP_KMEMCG
;
3378 static struct kmem_cache
*memcg_create_kmem_cache(struct mem_cgroup
*memcg
,
3379 struct kmem_cache
*cachep
)
3381 struct kmem_cache
*new_cachep
;
3384 BUG_ON(!memcg_can_account_kmem(memcg
));
3386 idx
= memcg_cache_id(memcg
);
3388 mutex_lock(&memcg_cache_mutex
);
3389 new_cachep
= cachep
->memcg_params
->memcg_caches
[idx
];
3393 new_cachep
= kmem_cache_dup(memcg
, cachep
);
3394 if (new_cachep
== NULL
) {
3395 new_cachep
= cachep
;
3399 mem_cgroup_get(memcg
);
3400 atomic_set(&new_cachep
->memcg_params
->nr_pages
, 0);
3402 cachep
->memcg_params
->memcg_caches
[idx
] = new_cachep
;
3404 * the readers won't lock, make sure everybody sees the updated value,
3405 * so they won't put stuff in the queue again for no reason
3409 mutex_unlock(&memcg_cache_mutex
);
3413 void kmem_cache_destroy_memcg_children(struct kmem_cache
*s
)
3415 struct kmem_cache
*c
;
3418 if (!s
->memcg_params
)
3420 if (!s
->memcg_params
->is_root_cache
)
3424 * If the cache is being destroyed, we trust that there is no one else
3425 * requesting objects from it. Even if there are, the sanity checks in
3426 * kmem_cache_destroy should caught this ill-case.
3428 * Still, we don't want anyone else freeing memcg_caches under our
3429 * noses, which can happen if a new memcg comes to life. As usual,
3430 * we'll take the set_limit_mutex to protect ourselves against this.
3432 mutex_lock(&set_limit_mutex
);
3433 for (i
= 0; i
< memcg_limited_groups_array_size
; i
++) {
3434 c
= s
->memcg_params
->memcg_caches
[i
];
3439 * We will now manually delete the caches, so to avoid races
3440 * we need to cancel all pending destruction workers and
3441 * proceed with destruction ourselves.
3443 * kmem_cache_destroy() will call kmem_cache_shrink internally,
3444 * and that could spawn the workers again: it is likely that
3445 * the cache still have active pages until this very moment.
3446 * This would lead us back to mem_cgroup_destroy_cache.
3448 * But that will not execute at all if the "dead" flag is not
3449 * set, so flip it down to guarantee we are in control.
3451 c
->memcg_params
->dead
= false;
3452 cancel_work_sync(&c
->memcg_params
->destroy
);
3453 kmem_cache_destroy(c
);
3455 mutex_unlock(&set_limit_mutex
);
3458 struct create_work
{
3459 struct mem_cgroup
*memcg
;
3460 struct kmem_cache
*cachep
;
3461 struct work_struct work
;
3464 static void mem_cgroup_destroy_all_caches(struct mem_cgroup
*memcg
)
3466 struct kmem_cache
*cachep
;
3467 struct memcg_cache_params
*params
;
3469 if (!memcg_kmem_is_active(memcg
))
3472 mutex_lock(&memcg
->slab_caches_mutex
);
3473 list_for_each_entry(params
, &memcg
->memcg_slab_caches
, list
) {
3474 cachep
= memcg_params_to_cache(params
);
3475 cachep
->memcg_params
->dead
= true;
3476 schedule_work(&cachep
->memcg_params
->destroy
);
3478 mutex_unlock(&memcg
->slab_caches_mutex
);
3481 static void memcg_create_cache_work_func(struct work_struct
*w
)
3483 struct create_work
*cw
;
3485 cw
= container_of(w
, struct create_work
, work
);
3486 memcg_create_kmem_cache(cw
->memcg
, cw
->cachep
);
3487 /* Drop the reference gotten when we enqueued. */
3488 css_put(&cw
->memcg
->css
);
3493 * Enqueue the creation of a per-memcg kmem_cache.
3495 static void __memcg_create_cache_enqueue(struct mem_cgroup
*memcg
,
3496 struct kmem_cache
*cachep
)
3498 struct create_work
*cw
;
3500 cw
= kmalloc(sizeof(struct create_work
), GFP_NOWAIT
);
3502 css_put(&memcg
->css
);
3507 cw
->cachep
= cachep
;
3509 INIT_WORK(&cw
->work
, memcg_create_cache_work_func
);
3510 schedule_work(&cw
->work
);
3513 static void memcg_create_cache_enqueue(struct mem_cgroup
*memcg
,
3514 struct kmem_cache
*cachep
)
3517 * We need to stop accounting when we kmalloc, because if the
3518 * corresponding kmalloc cache is not yet created, the first allocation
3519 * in __memcg_create_cache_enqueue will recurse.
3521 * However, it is better to enclose the whole function. Depending on
3522 * the debugging options enabled, INIT_WORK(), for instance, can
3523 * trigger an allocation. This too, will make us recurse. Because at
3524 * this point we can't allow ourselves back into memcg_kmem_get_cache,
3525 * the safest choice is to do it like this, wrapping the whole function.
3527 memcg_stop_kmem_account();
3528 __memcg_create_cache_enqueue(memcg
, cachep
);
3529 memcg_resume_kmem_account();
3532 * Return the kmem_cache we're supposed to use for a slab allocation.
3533 * We try to use the current memcg's version of the cache.
3535 * If the cache does not exist yet, if we are the first user of it,
3536 * we either create it immediately, if possible, or create it asynchronously
3538 * In the latter case, we will let the current allocation go through with
3539 * the original cache.
3541 * Can't be called in interrupt context or from kernel threads.
3542 * This function needs to be called with rcu_read_lock() held.
3544 struct kmem_cache
*__memcg_kmem_get_cache(struct kmem_cache
*cachep
,
3547 struct mem_cgroup
*memcg
;
3550 VM_BUG_ON(!cachep
->memcg_params
);
3551 VM_BUG_ON(!cachep
->memcg_params
->is_root_cache
);
3553 if (!current
->mm
|| current
->memcg_kmem_skip_account
)
3557 memcg
= mem_cgroup_from_task(rcu_dereference(current
->mm
->owner
));
3559 if (!memcg_can_account_kmem(memcg
))
3562 idx
= memcg_cache_id(memcg
);
3565 * barrier to mare sure we're always seeing the up to date value. The
3566 * code updating memcg_caches will issue a write barrier to match this.
3568 read_barrier_depends();
3569 if (likely(cachep
->memcg_params
->memcg_caches
[idx
])) {
3570 cachep
= cachep
->memcg_params
->memcg_caches
[idx
];
3574 /* The corresponding put will be done in the workqueue. */
3575 if (!css_tryget(&memcg
->css
))
3580 * If we are in a safe context (can wait, and not in interrupt
3581 * context), we could be be predictable and return right away.
3582 * This would guarantee that the allocation being performed
3583 * already belongs in the new cache.
3585 * However, there are some clashes that can arrive from locking.
3586 * For instance, because we acquire the slab_mutex while doing
3587 * kmem_cache_dup, this means no further allocation could happen
3588 * with the slab_mutex held.
3590 * Also, because cache creation issue get_online_cpus(), this
3591 * creates a lock chain: memcg_slab_mutex -> cpu_hotplug_mutex,
3592 * that ends up reversed during cpu hotplug. (cpuset allocates
3593 * a bunch of GFP_KERNEL memory during cpuup). Due to all that,
3594 * better to defer everything.
3596 memcg_create_cache_enqueue(memcg
, cachep
);
3602 EXPORT_SYMBOL(__memcg_kmem_get_cache
);
3605 * We need to verify if the allocation against current->mm->owner's memcg is
3606 * possible for the given order. But the page is not allocated yet, so we'll
3607 * need a further commit step to do the final arrangements.
3609 * It is possible for the task to switch cgroups in this mean time, so at
3610 * commit time, we can't rely on task conversion any longer. We'll then use
3611 * the handle argument to return to the caller which cgroup we should commit
3612 * against. We could also return the memcg directly and avoid the pointer
3613 * passing, but a boolean return value gives better semantics considering
3614 * the compiled-out case as well.
3616 * Returning true means the allocation is possible.
3619 __memcg_kmem_newpage_charge(gfp_t gfp
, struct mem_cgroup
**_memcg
, int order
)
3621 struct mem_cgroup
*memcg
;
3625 memcg
= try_get_mem_cgroup_from_mm(current
->mm
);
3628 * very rare case described in mem_cgroup_from_task. Unfortunately there
3629 * isn't much we can do without complicating this too much, and it would
3630 * be gfp-dependent anyway. Just let it go
3632 if (unlikely(!memcg
))
3635 if (!memcg_can_account_kmem(memcg
)) {
3636 css_put(&memcg
->css
);
3640 ret
= memcg_charge_kmem(memcg
, gfp
, PAGE_SIZE
<< order
);
3644 css_put(&memcg
->css
);
3648 void __memcg_kmem_commit_charge(struct page
*page
, struct mem_cgroup
*memcg
,
3651 struct page_cgroup
*pc
;
3653 VM_BUG_ON(mem_cgroup_is_root(memcg
));
3655 /* The page allocation failed. Revert */
3657 memcg_uncharge_kmem(memcg
, PAGE_SIZE
<< order
);
3661 pc
= lookup_page_cgroup(page
);
3662 lock_page_cgroup(pc
);
3663 pc
->mem_cgroup
= memcg
;
3664 SetPageCgroupUsed(pc
);
3665 unlock_page_cgroup(pc
);
3668 void __memcg_kmem_uncharge_pages(struct page
*page
, int order
)
3670 struct mem_cgroup
*memcg
= NULL
;
3671 struct page_cgroup
*pc
;
3674 pc
= lookup_page_cgroup(page
);
3676 * Fast unlocked return. Theoretically might have changed, have to
3677 * check again after locking.
3679 if (!PageCgroupUsed(pc
))
3682 lock_page_cgroup(pc
);
3683 if (PageCgroupUsed(pc
)) {
3684 memcg
= pc
->mem_cgroup
;
3685 ClearPageCgroupUsed(pc
);
3687 unlock_page_cgroup(pc
);
3690 * We trust that only if there is a memcg associated with the page, it
3691 * is a valid allocation
3696 VM_BUG_ON(mem_cgroup_is_root(memcg
));
3697 memcg_uncharge_kmem(memcg
, PAGE_SIZE
<< order
);
3700 static inline void mem_cgroup_destroy_all_caches(struct mem_cgroup
*memcg
)
3703 #endif /* CONFIG_MEMCG_KMEM */
3705 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
3707 #define PCGF_NOCOPY_AT_SPLIT (1 << PCG_LOCK | 1 << PCG_MIGRATION)
3709 * Because tail pages are not marked as "used", set it. We're under
3710 * zone->lru_lock, 'splitting on pmd' and compound_lock.
3711 * charge/uncharge will be never happen and move_account() is done under
3712 * compound_lock(), so we don't have to take care of races.
3714 void mem_cgroup_split_huge_fixup(struct page
*head
)
3716 struct page_cgroup
*head_pc
= lookup_page_cgroup(head
);
3717 struct page_cgroup
*pc
;
3718 struct mem_cgroup
*memcg
;
3721 if (mem_cgroup_disabled())
3724 memcg
= head_pc
->mem_cgroup
;
3725 for (i
= 1; i
< HPAGE_PMD_NR
; i
++) {
3727 pc
->mem_cgroup
= memcg
;
3728 smp_wmb();/* see __commit_charge() */
3729 pc
->flags
= head_pc
->flags
& ~PCGF_NOCOPY_AT_SPLIT
;
3731 __this_cpu_sub(memcg
->stat
->count
[MEM_CGROUP_STAT_RSS_HUGE
],
3734 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
3737 * mem_cgroup_move_account - move account of the page
3739 * @nr_pages: number of regular pages (>1 for huge pages)
3740 * @pc: page_cgroup of the page.
3741 * @from: mem_cgroup which the page is moved from.
3742 * @to: mem_cgroup which the page is moved to. @from != @to.
3744 * The caller must confirm following.
3745 * - page is not on LRU (isolate_page() is useful.)
3746 * - compound_lock is held when nr_pages > 1
3748 * This function doesn't do "charge" to new cgroup and doesn't do "uncharge"
3751 static int mem_cgroup_move_account(struct page
*page
,
3752 unsigned int nr_pages
,
3753 struct page_cgroup
*pc
,
3754 struct mem_cgroup
*from
,
3755 struct mem_cgroup
*to
)
3757 unsigned long flags
;
3759 bool anon
= PageAnon(page
);
3761 VM_BUG_ON(from
== to
);
3762 VM_BUG_ON(PageLRU(page
));
3764 * The page is isolated from LRU. So, collapse function
3765 * will not handle this page. But page splitting can happen.
3766 * Do this check under compound_page_lock(). The caller should
3770 if (nr_pages
> 1 && !PageTransHuge(page
))
3773 lock_page_cgroup(pc
);
3776 if (!PageCgroupUsed(pc
) || pc
->mem_cgroup
!= from
)
3779 move_lock_mem_cgroup(from
, &flags
);
3781 if (!anon
&& page_mapped(page
)) {
3782 /* Update mapped_file data for mem_cgroup */
3784 __this_cpu_dec(from
->stat
->count
[MEM_CGROUP_STAT_FILE_MAPPED
]);
3785 __this_cpu_inc(to
->stat
->count
[MEM_CGROUP_STAT_FILE_MAPPED
]);
3788 mem_cgroup_charge_statistics(from
, page
, anon
, -nr_pages
);
3790 /* caller should have done css_get */
3791 pc
->mem_cgroup
= to
;
3792 mem_cgroup_charge_statistics(to
, page
, anon
, nr_pages
);
3793 move_unlock_mem_cgroup(from
, &flags
);
3796 unlock_page_cgroup(pc
);
3800 memcg_check_events(to
, page
);
3801 memcg_check_events(from
, page
);
3807 * mem_cgroup_move_parent - moves page to the parent group
3808 * @page: the page to move
3809 * @pc: page_cgroup of the page
3810 * @child: page's cgroup
3812 * move charges to its parent or the root cgroup if the group has no
3813 * parent (aka use_hierarchy==0).
3814 * Although this might fail (get_page_unless_zero, isolate_lru_page or
3815 * mem_cgroup_move_account fails) the failure is always temporary and
3816 * it signals a race with a page removal/uncharge or migration. In the
3817 * first case the page is on the way out and it will vanish from the LRU
3818 * on the next attempt and the call should be retried later.
3819 * Isolation from the LRU fails only if page has been isolated from
3820 * the LRU since we looked at it and that usually means either global
3821 * reclaim or migration going on. The page will either get back to the
3823 * Finaly mem_cgroup_move_account fails only if the page got uncharged
3824 * (!PageCgroupUsed) or moved to a different group. The page will
3825 * disappear in the next attempt.
3827 static int mem_cgroup_move_parent(struct page
*page
,
3828 struct page_cgroup
*pc
,
3829 struct mem_cgroup
*child
)
3831 struct mem_cgroup
*parent
;
3832 unsigned int nr_pages
;
3833 unsigned long uninitialized_var(flags
);
3836 VM_BUG_ON(mem_cgroup_is_root(child
));
3839 if (!get_page_unless_zero(page
))
3841 if (isolate_lru_page(page
))
3844 nr_pages
= hpage_nr_pages(page
);
3846 parent
= parent_mem_cgroup(child
);
3848 * If no parent, move charges to root cgroup.
3851 parent
= root_mem_cgroup
;
3854 VM_BUG_ON(!PageTransHuge(page
));
3855 flags
= compound_lock_irqsave(page
);
3858 ret
= mem_cgroup_move_account(page
, nr_pages
,
3861 __mem_cgroup_cancel_local_charge(child
, nr_pages
);
3864 compound_unlock_irqrestore(page
, flags
);
3865 putback_lru_page(page
);
3873 * Charge the memory controller for page usage.
3875 * 0 if the charge was successful
3876 * < 0 if the cgroup is over its limit
3878 static int mem_cgroup_charge_common(struct page
*page
, struct mm_struct
*mm
,
3879 gfp_t gfp_mask
, enum charge_type ctype
)
3881 struct mem_cgroup
*memcg
= NULL
;
3882 unsigned int nr_pages
= 1;
3886 if (PageTransHuge(page
)) {
3887 nr_pages
<<= compound_order(page
);
3888 VM_BUG_ON(!PageTransHuge(page
));
3890 * Never OOM-kill a process for a huge page. The
3891 * fault handler will fall back to regular pages.
3896 ret
= __mem_cgroup_try_charge(mm
, gfp_mask
, nr_pages
, &memcg
, oom
);
3899 __mem_cgroup_commit_charge(memcg
, page
, nr_pages
, ctype
, false);
3903 int mem_cgroup_newpage_charge(struct page
*page
,
3904 struct mm_struct
*mm
, gfp_t gfp_mask
)
3906 if (mem_cgroup_disabled())
3908 VM_BUG_ON(page_mapped(page
));
3909 VM_BUG_ON(page
->mapping
&& !PageAnon(page
));
3911 return mem_cgroup_charge_common(page
, mm
, gfp_mask
,
3912 MEM_CGROUP_CHARGE_TYPE_ANON
);
3916 * While swap-in, try_charge -> commit or cancel, the page is locked.
3917 * And when try_charge() successfully returns, one refcnt to memcg without
3918 * struct page_cgroup is acquired. This refcnt will be consumed by
3919 * "commit()" or removed by "cancel()"
3921 static int __mem_cgroup_try_charge_swapin(struct mm_struct
*mm
,
3924 struct mem_cgroup
**memcgp
)
3926 struct mem_cgroup
*memcg
;
3927 struct page_cgroup
*pc
;
3930 pc
= lookup_page_cgroup(page
);
3932 * Every swap fault against a single page tries to charge the
3933 * page, bail as early as possible. shmem_unuse() encounters
3934 * already charged pages, too. The USED bit is protected by
3935 * the page lock, which serializes swap cache removal, which
3936 * in turn serializes uncharging.
3938 if (PageCgroupUsed(pc
))
3940 if (!do_swap_account
)
3942 memcg
= try_get_mem_cgroup_from_page(page
);
3946 ret
= __mem_cgroup_try_charge(NULL
, mask
, 1, memcgp
, true);
3947 css_put(&memcg
->css
);
3952 ret
= __mem_cgroup_try_charge(mm
, mask
, 1, memcgp
, true);
3958 int mem_cgroup_try_charge_swapin(struct mm_struct
*mm
, struct page
*page
,
3959 gfp_t gfp_mask
, struct mem_cgroup
**memcgp
)
3962 if (mem_cgroup_disabled())
3965 * A racing thread's fault, or swapoff, may have already
3966 * updated the pte, and even removed page from swap cache: in
3967 * those cases unuse_pte()'s pte_same() test will fail; but
3968 * there's also a KSM case which does need to charge the page.
3970 if (!PageSwapCache(page
)) {
3973 ret
= __mem_cgroup_try_charge(mm
, gfp_mask
, 1, memcgp
, true);
3978 return __mem_cgroup_try_charge_swapin(mm
, page
, gfp_mask
, memcgp
);
3981 void mem_cgroup_cancel_charge_swapin(struct mem_cgroup
*memcg
)
3983 if (mem_cgroup_disabled())
3987 __mem_cgroup_cancel_charge(memcg
, 1);
3991 __mem_cgroup_commit_charge_swapin(struct page
*page
, struct mem_cgroup
*memcg
,
3992 enum charge_type ctype
)
3994 if (mem_cgroup_disabled())
3999 __mem_cgroup_commit_charge(memcg
, page
, 1, ctype
, true);
4001 * Now swap is on-memory. This means this page may be
4002 * counted both as mem and swap....double count.
4003 * Fix it by uncharging from memsw. Basically, this SwapCache is stable
4004 * under lock_page(). But in do_swap_page()::memory.c, reuse_swap_page()
4005 * may call delete_from_swap_cache() before reach here.
4007 if (do_swap_account
&& PageSwapCache(page
)) {
4008 swp_entry_t ent
= {.val
= page_private(page
)};
4009 mem_cgroup_uncharge_swap(ent
);
4013 void mem_cgroup_commit_charge_swapin(struct page
*page
,
4014 struct mem_cgroup
*memcg
)
4016 __mem_cgroup_commit_charge_swapin(page
, memcg
,
4017 MEM_CGROUP_CHARGE_TYPE_ANON
);
4020 int mem_cgroup_cache_charge(struct page
*page
, struct mm_struct
*mm
,
4023 struct mem_cgroup
*memcg
= NULL
;
4024 enum charge_type type
= MEM_CGROUP_CHARGE_TYPE_CACHE
;
4027 if (mem_cgroup_disabled())
4029 if (PageCompound(page
))
4032 if (!PageSwapCache(page
))
4033 ret
= mem_cgroup_charge_common(page
, mm
, gfp_mask
, type
);
4034 else { /* page is swapcache/shmem */
4035 ret
= __mem_cgroup_try_charge_swapin(mm
, page
,
4038 __mem_cgroup_commit_charge_swapin(page
, memcg
, type
);
4043 static void mem_cgroup_do_uncharge(struct mem_cgroup
*memcg
,
4044 unsigned int nr_pages
,
4045 const enum charge_type ctype
)
4047 struct memcg_batch_info
*batch
= NULL
;
4048 bool uncharge_memsw
= true;
4050 /* If swapout, usage of swap doesn't decrease */
4051 if (!do_swap_account
|| ctype
== MEM_CGROUP_CHARGE_TYPE_SWAPOUT
)
4052 uncharge_memsw
= false;
4054 batch
= ¤t
->memcg_batch
;
4056 * In usual, we do css_get() when we remember memcg pointer.
4057 * But in this case, we keep res->usage until end of a series of
4058 * uncharges. Then, it's ok to ignore memcg's refcnt.
4061 batch
->memcg
= memcg
;
4063 * do_batch > 0 when unmapping pages or inode invalidate/truncate.
4064 * In those cases, all pages freed continuously can be expected to be in
4065 * the same cgroup and we have chance to coalesce uncharges.
4066 * But we do uncharge one by one if this is killed by OOM(TIF_MEMDIE)
4067 * because we want to do uncharge as soon as possible.
4070 if (!batch
->do_batch
|| test_thread_flag(TIF_MEMDIE
))
4071 goto direct_uncharge
;
4074 goto direct_uncharge
;
4077 * In typical case, batch->memcg == mem. This means we can
4078 * merge a series of uncharges to an uncharge of res_counter.
4079 * If not, we uncharge res_counter ony by one.
4081 if (batch
->memcg
!= memcg
)
4082 goto direct_uncharge
;
4083 /* remember freed charge and uncharge it later */
4086 batch
->memsw_nr_pages
++;
4089 res_counter_uncharge(&memcg
->res
, nr_pages
* PAGE_SIZE
);
4091 res_counter_uncharge(&memcg
->memsw
, nr_pages
* PAGE_SIZE
);
4092 if (unlikely(batch
->memcg
!= memcg
))
4093 memcg_oom_recover(memcg
);
4097 * uncharge if !page_mapped(page)
4099 static struct mem_cgroup
*
4100 __mem_cgroup_uncharge_common(struct page
*page
, enum charge_type ctype
,
4103 struct mem_cgroup
*memcg
= NULL
;
4104 unsigned int nr_pages
= 1;
4105 struct page_cgroup
*pc
;
4108 if (mem_cgroup_disabled())
4111 VM_BUG_ON(PageSwapCache(page
));
4113 if (PageTransHuge(page
)) {
4114 nr_pages
<<= compound_order(page
);
4115 VM_BUG_ON(!PageTransHuge(page
));
4118 * Check if our page_cgroup is valid
4120 pc
= lookup_page_cgroup(page
);
4121 if (unlikely(!PageCgroupUsed(pc
)))
4124 lock_page_cgroup(pc
);
4126 memcg
= pc
->mem_cgroup
;
4128 if (!PageCgroupUsed(pc
))
4131 anon
= PageAnon(page
);
4134 case MEM_CGROUP_CHARGE_TYPE_ANON
:
4136 * Generally PageAnon tells if it's the anon statistics to be
4137 * updated; but sometimes e.g. mem_cgroup_uncharge_page() is
4138 * used before page reached the stage of being marked PageAnon.
4142 case MEM_CGROUP_CHARGE_TYPE_DROP
:
4143 /* See mem_cgroup_prepare_migration() */
4144 if (page_mapped(page
))
4147 * Pages under migration may not be uncharged. But
4148 * end_migration() /must/ be the one uncharging the
4149 * unused post-migration page and so it has to call
4150 * here with the migration bit still set. See the
4151 * res_counter handling below.
4153 if (!end_migration
&& PageCgroupMigration(pc
))
4156 case MEM_CGROUP_CHARGE_TYPE_SWAPOUT
:
4157 if (!PageAnon(page
)) { /* Shared memory */
4158 if (page
->mapping
&& !page_is_file_cache(page
))
4160 } else if (page_mapped(page
)) /* Anon */
4167 mem_cgroup_charge_statistics(memcg
, page
, anon
, -nr_pages
);
4169 ClearPageCgroupUsed(pc
);
4171 * pc->mem_cgroup is not cleared here. It will be accessed when it's
4172 * freed from LRU. This is safe because uncharged page is expected not
4173 * to be reused (freed soon). Exception is SwapCache, it's handled by
4174 * special functions.
4177 unlock_page_cgroup(pc
);
4179 * even after unlock, we have memcg->res.usage here and this memcg
4180 * will never be freed.
4182 memcg_check_events(memcg
, page
);
4183 if (do_swap_account
&& ctype
== MEM_CGROUP_CHARGE_TYPE_SWAPOUT
) {
4184 mem_cgroup_swap_statistics(memcg
, true);
4185 mem_cgroup_get(memcg
);
4188 * Migration does not charge the res_counter for the
4189 * replacement page, so leave it alone when phasing out the
4190 * page that is unused after the migration.
4192 if (!end_migration
&& !mem_cgroup_is_root(memcg
))
4193 mem_cgroup_do_uncharge(memcg
, nr_pages
, ctype
);
4198 unlock_page_cgroup(pc
);
4202 void mem_cgroup_uncharge_page(struct page
*page
)
4205 if (page_mapped(page
))
4207 VM_BUG_ON(page
->mapping
&& !PageAnon(page
));
4208 if (PageSwapCache(page
))
4210 __mem_cgroup_uncharge_common(page
, MEM_CGROUP_CHARGE_TYPE_ANON
, false);
4213 void mem_cgroup_uncharge_cache_page(struct page
*page
)
4215 VM_BUG_ON(page_mapped(page
));
4216 VM_BUG_ON(page
->mapping
);
4217 __mem_cgroup_uncharge_common(page
, MEM_CGROUP_CHARGE_TYPE_CACHE
, false);
4221 * Batch_start/batch_end is called in unmap_page_range/invlidate/trucate.
4222 * In that cases, pages are freed continuously and we can expect pages
4223 * are in the same memcg. All these calls itself limits the number of
4224 * pages freed at once, then uncharge_start/end() is called properly.
4225 * This may be called prural(2) times in a context,
4228 void mem_cgroup_uncharge_start(void)
4230 current
->memcg_batch
.do_batch
++;
4231 /* We can do nest. */
4232 if (current
->memcg_batch
.do_batch
== 1) {
4233 current
->memcg_batch
.memcg
= NULL
;
4234 current
->memcg_batch
.nr_pages
= 0;
4235 current
->memcg_batch
.memsw_nr_pages
= 0;
4239 void mem_cgroup_uncharge_end(void)
4241 struct memcg_batch_info
*batch
= ¤t
->memcg_batch
;
4243 if (!batch
->do_batch
)
4247 if (batch
->do_batch
) /* If stacked, do nothing. */
4253 * This "batch->memcg" is valid without any css_get/put etc...
4254 * bacause we hide charges behind us.
4256 if (batch
->nr_pages
)
4257 res_counter_uncharge(&batch
->memcg
->res
,
4258 batch
->nr_pages
* PAGE_SIZE
);
4259 if (batch
->memsw_nr_pages
)
4260 res_counter_uncharge(&batch
->memcg
->memsw
,
4261 batch
->memsw_nr_pages
* PAGE_SIZE
);
4262 memcg_oom_recover(batch
->memcg
);
4263 /* forget this pointer (for sanity check) */
4264 batch
->memcg
= NULL
;
4269 * called after __delete_from_swap_cache() and drop "page" account.
4270 * memcg information is recorded to swap_cgroup of "ent"
4273 mem_cgroup_uncharge_swapcache(struct page
*page
, swp_entry_t ent
, bool swapout
)
4275 struct mem_cgroup
*memcg
;
4276 int ctype
= MEM_CGROUP_CHARGE_TYPE_SWAPOUT
;
4278 if (!swapout
) /* this was a swap cache but the swap is unused ! */
4279 ctype
= MEM_CGROUP_CHARGE_TYPE_DROP
;
4281 memcg
= __mem_cgroup_uncharge_common(page
, ctype
, false);
4284 * record memcg information, if swapout && memcg != NULL,
4285 * mem_cgroup_get() was called in uncharge().
4287 if (do_swap_account
&& swapout
&& memcg
)
4288 swap_cgroup_record(ent
, css_id(&memcg
->css
));
4292 #ifdef CONFIG_MEMCG_SWAP
4294 * called from swap_entry_free(). remove record in swap_cgroup and
4295 * uncharge "memsw" account.
4297 void mem_cgroup_uncharge_swap(swp_entry_t ent
)
4299 struct mem_cgroup
*memcg
;
4302 if (!do_swap_account
)
4305 id
= swap_cgroup_record(ent
, 0);
4307 memcg
= mem_cgroup_lookup(id
);
4310 * We uncharge this because swap is freed.
4311 * This memcg can be obsolete one. We avoid calling css_tryget
4313 if (!mem_cgroup_is_root(memcg
))
4314 res_counter_uncharge(&memcg
->memsw
, PAGE_SIZE
);
4315 mem_cgroup_swap_statistics(memcg
, false);
4316 mem_cgroup_put(memcg
);
4322 * mem_cgroup_move_swap_account - move swap charge and swap_cgroup's record.
4323 * @entry: swap entry to be moved
4324 * @from: mem_cgroup which the entry is moved from
4325 * @to: mem_cgroup which the entry is moved to
4327 * It succeeds only when the swap_cgroup's record for this entry is the same
4328 * as the mem_cgroup's id of @from.
4330 * Returns 0 on success, -EINVAL on failure.
4332 * The caller must have charged to @to, IOW, called res_counter_charge() about
4333 * both res and memsw, and called css_get().
4335 static int mem_cgroup_move_swap_account(swp_entry_t entry
,
4336 struct mem_cgroup
*from
, struct mem_cgroup
*to
)
4338 unsigned short old_id
, new_id
;
4340 old_id
= css_id(&from
->css
);
4341 new_id
= css_id(&to
->css
);
4343 if (swap_cgroup_cmpxchg(entry
, old_id
, new_id
) == old_id
) {
4344 mem_cgroup_swap_statistics(from
, false);
4345 mem_cgroup_swap_statistics(to
, true);
4347 * This function is only called from task migration context now.
4348 * It postpones res_counter and refcount handling till the end
4349 * of task migration(mem_cgroup_clear_mc()) for performance
4350 * improvement. But we cannot postpone mem_cgroup_get(to)
4351 * because if the process that has been moved to @to does
4352 * swap-in, the refcount of @to might be decreased to 0.
4360 static inline int mem_cgroup_move_swap_account(swp_entry_t entry
,
4361 struct mem_cgroup
*from
, struct mem_cgroup
*to
)
4368 * Before starting migration, account PAGE_SIZE to mem_cgroup that the old
4371 void mem_cgroup_prepare_migration(struct page
*page
, struct page
*newpage
,
4372 struct mem_cgroup
**memcgp
)
4374 struct mem_cgroup
*memcg
= NULL
;
4375 unsigned int nr_pages
= 1;
4376 struct page_cgroup
*pc
;
4377 enum charge_type ctype
;
4381 if (mem_cgroup_disabled())
4384 if (PageTransHuge(page
))
4385 nr_pages
<<= compound_order(page
);
4387 pc
= lookup_page_cgroup(page
);
4388 lock_page_cgroup(pc
);
4389 if (PageCgroupUsed(pc
)) {
4390 memcg
= pc
->mem_cgroup
;
4391 css_get(&memcg
->css
);
4393 * At migrating an anonymous page, its mapcount goes down
4394 * to 0 and uncharge() will be called. But, even if it's fully
4395 * unmapped, migration may fail and this page has to be
4396 * charged again. We set MIGRATION flag here and delay uncharge
4397 * until end_migration() is called
4399 * Corner Case Thinking
4401 * When the old page was mapped as Anon and it's unmap-and-freed
4402 * while migration was ongoing.
4403 * If unmap finds the old page, uncharge() of it will be delayed
4404 * until end_migration(). If unmap finds a new page, it's
4405 * uncharged when it make mapcount to be 1->0. If unmap code
4406 * finds swap_migration_entry, the new page will not be mapped
4407 * and end_migration() will find it(mapcount==0).
4410 * When the old page was mapped but migraion fails, the kernel
4411 * remaps it. A charge for it is kept by MIGRATION flag even
4412 * if mapcount goes down to 0. We can do remap successfully
4413 * without charging it again.
4416 * The "old" page is under lock_page() until the end of
4417 * migration, so, the old page itself will not be swapped-out.
4418 * If the new page is swapped out before end_migraton, our
4419 * hook to usual swap-out path will catch the event.
4422 SetPageCgroupMigration(pc
);
4424 unlock_page_cgroup(pc
);
4426 * If the page is not charged at this point,
4434 * We charge new page before it's used/mapped. So, even if unlock_page()
4435 * is called before end_migration, we can catch all events on this new
4436 * page. In the case new page is migrated but not remapped, new page's
4437 * mapcount will be finally 0 and we call uncharge in end_migration().
4440 ctype
= MEM_CGROUP_CHARGE_TYPE_ANON
;
4442 ctype
= MEM_CGROUP_CHARGE_TYPE_CACHE
;
4444 * The page is committed to the memcg, but it's not actually
4445 * charged to the res_counter since we plan on replacing the
4446 * old one and only one page is going to be left afterwards.
4448 __mem_cgroup_commit_charge(memcg
, newpage
, nr_pages
, ctype
, false);
4451 /* remove redundant charge if migration failed*/
4452 void mem_cgroup_end_migration(struct mem_cgroup
*memcg
,
4453 struct page
*oldpage
, struct page
*newpage
, bool migration_ok
)
4455 struct page
*used
, *unused
;
4456 struct page_cgroup
*pc
;
4462 if (!migration_ok
) {
4469 anon
= PageAnon(used
);
4470 __mem_cgroup_uncharge_common(unused
,
4471 anon
? MEM_CGROUP_CHARGE_TYPE_ANON
4472 : MEM_CGROUP_CHARGE_TYPE_CACHE
,
4474 css_put(&memcg
->css
);
4476 * We disallowed uncharge of pages under migration because mapcount
4477 * of the page goes down to zero, temporarly.
4478 * Clear the flag and check the page should be charged.
4480 pc
= lookup_page_cgroup(oldpage
);
4481 lock_page_cgroup(pc
);
4482 ClearPageCgroupMigration(pc
);
4483 unlock_page_cgroup(pc
);
4486 * If a page is a file cache, radix-tree replacement is very atomic
4487 * and we can skip this check. When it was an Anon page, its mapcount
4488 * goes down to 0. But because we added MIGRATION flage, it's not
4489 * uncharged yet. There are several case but page->mapcount check
4490 * and USED bit check in mem_cgroup_uncharge_page() will do enough
4491 * check. (see prepare_charge() also)
4494 mem_cgroup_uncharge_page(used
);
4498 * At replace page cache, newpage is not under any memcg but it's on
4499 * LRU. So, this function doesn't touch res_counter but handles LRU
4500 * in correct way. Both pages are locked so we cannot race with uncharge.
4502 void mem_cgroup_replace_page_cache(struct page
*oldpage
,
4503 struct page
*newpage
)
4505 struct mem_cgroup
*memcg
= NULL
;
4506 struct page_cgroup
*pc
;
4507 enum charge_type type
= MEM_CGROUP_CHARGE_TYPE_CACHE
;
4509 if (mem_cgroup_disabled())
4512 pc
= lookup_page_cgroup(oldpage
);
4513 /* fix accounting on old pages */
4514 lock_page_cgroup(pc
);
4515 if (PageCgroupUsed(pc
)) {
4516 memcg
= pc
->mem_cgroup
;
4517 mem_cgroup_charge_statistics(memcg
, oldpage
, false, -1);
4518 ClearPageCgroupUsed(pc
);
4520 unlock_page_cgroup(pc
);
4523 * When called from shmem_replace_page(), in some cases the
4524 * oldpage has already been charged, and in some cases not.
4529 * Even if newpage->mapping was NULL before starting replacement,
4530 * the newpage may be on LRU(or pagevec for LRU) already. We lock
4531 * LRU while we overwrite pc->mem_cgroup.
4533 __mem_cgroup_commit_charge(memcg
, newpage
, 1, type
, true);
4536 #ifdef CONFIG_DEBUG_VM
4537 static struct page_cgroup
*lookup_page_cgroup_used(struct page
*page
)
4539 struct page_cgroup
*pc
;
4541 pc
= lookup_page_cgroup(page
);
4543 * Can be NULL while feeding pages into the page allocator for
4544 * the first time, i.e. during boot or memory hotplug;
4545 * or when mem_cgroup_disabled().
4547 if (likely(pc
) && PageCgroupUsed(pc
))
4552 bool mem_cgroup_bad_page_check(struct page
*page
)
4554 if (mem_cgroup_disabled())
4557 return lookup_page_cgroup_used(page
) != NULL
;
4560 void mem_cgroup_print_bad_page(struct page
*page
)
4562 struct page_cgroup
*pc
;
4564 pc
= lookup_page_cgroup_used(page
);
4566 pr_alert("pc:%p pc->flags:%lx pc->mem_cgroup:%p\n",
4567 pc
, pc
->flags
, pc
->mem_cgroup
);
4572 static int mem_cgroup_resize_limit(struct mem_cgroup
*memcg
,
4573 unsigned long long val
)
4576 u64 memswlimit
, memlimit
;
4578 int children
= mem_cgroup_count_children(memcg
);
4579 u64 curusage
, oldusage
;
4583 * For keeping hierarchical_reclaim simple, how long we should retry
4584 * is depends on callers. We set our retry-count to be function
4585 * of # of children which we should visit in this loop.
4587 retry_count
= MEM_CGROUP_RECLAIM_RETRIES
* children
;
4589 oldusage
= res_counter_read_u64(&memcg
->res
, RES_USAGE
);
4592 while (retry_count
) {
4593 if (signal_pending(current
)) {
4598 * Rather than hide all in some function, I do this in
4599 * open coded manner. You see what this really does.
4600 * We have to guarantee memcg->res.limit <= memcg->memsw.limit.
4602 mutex_lock(&set_limit_mutex
);
4603 memswlimit
= res_counter_read_u64(&memcg
->memsw
, RES_LIMIT
);
4604 if (memswlimit
< val
) {
4606 mutex_unlock(&set_limit_mutex
);
4610 memlimit
= res_counter_read_u64(&memcg
->res
, RES_LIMIT
);
4614 ret
= res_counter_set_limit(&memcg
->res
, val
);
4616 if (memswlimit
== val
)
4617 memcg
->memsw_is_minimum
= true;
4619 memcg
->memsw_is_minimum
= false;
4621 mutex_unlock(&set_limit_mutex
);
4626 mem_cgroup_reclaim(memcg
, GFP_KERNEL
,
4627 MEM_CGROUP_RECLAIM_SHRINK
);
4628 curusage
= res_counter_read_u64(&memcg
->res
, RES_USAGE
);
4629 /* Usage is reduced ? */
4630 if (curusage
>= oldusage
)
4633 oldusage
= curusage
;
4635 if (!ret
&& enlarge
)
4636 memcg_oom_recover(memcg
);
4641 static int mem_cgroup_resize_memsw_limit(struct mem_cgroup
*memcg
,
4642 unsigned long long val
)
4645 u64 memlimit
, memswlimit
, oldusage
, curusage
;
4646 int children
= mem_cgroup_count_children(memcg
);
4650 /* see mem_cgroup_resize_res_limit */
4651 retry_count
= children
* MEM_CGROUP_RECLAIM_RETRIES
;
4652 oldusage
= res_counter_read_u64(&memcg
->memsw
, RES_USAGE
);
4653 while (retry_count
) {
4654 if (signal_pending(current
)) {
4659 * Rather than hide all in some function, I do this in
4660 * open coded manner. You see what this really does.
4661 * We have to guarantee memcg->res.limit <= memcg->memsw.limit.
4663 mutex_lock(&set_limit_mutex
);
4664 memlimit
= res_counter_read_u64(&memcg
->res
, RES_LIMIT
);
4665 if (memlimit
> val
) {
4667 mutex_unlock(&set_limit_mutex
);
4670 memswlimit
= res_counter_read_u64(&memcg
->memsw
, RES_LIMIT
);
4671 if (memswlimit
< val
)
4673 ret
= res_counter_set_limit(&memcg
->memsw
, val
);
4675 if (memlimit
== val
)
4676 memcg
->memsw_is_minimum
= true;
4678 memcg
->memsw_is_minimum
= false;
4680 mutex_unlock(&set_limit_mutex
);
4685 mem_cgroup_reclaim(memcg
, GFP_KERNEL
,
4686 MEM_CGROUP_RECLAIM_NOSWAP
|
4687 MEM_CGROUP_RECLAIM_SHRINK
);
4688 curusage
= res_counter_read_u64(&memcg
->memsw
, RES_USAGE
);
4689 /* Usage is reduced ? */
4690 if (curusage
>= oldusage
)
4693 oldusage
= curusage
;
4695 if (!ret
&& enlarge
)
4696 memcg_oom_recover(memcg
);
4700 unsigned long mem_cgroup_soft_limit_reclaim(struct zone
*zone
, int order
,
4702 unsigned long *total_scanned
)
4704 unsigned long nr_reclaimed
= 0;
4705 struct mem_cgroup_per_zone
*mz
, *next_mz
= NULL
;
4706 unsigned long reclaimed
;
4708 struct mem_cgroup_tree_per_zone
*mctz
;
4709 unsigned long long excess
;
4710 unsigned long nr_scanned
;
4715 mctz
= soft_limit_tree_node_zone(zone_to_nid(zone
), zone_idx(zone
));
4717 * This loop can run a while, specially if mem_cgroup's continuously
4718 * keep exceeding their soft limit and putting the system under
4725 mz
= mem_cgroup_largest_soft_limit_node(mctz
);
4730 reclaimed
= mem_cgroup_soft_reclaim(mz
->memcg
, zone
,
4731 gfp_mask
, &nr_scanned
);
4732 nr_reclaimed
+= reclaimed
;
4733 *total_scanned
+= nr_scanned
;
4734 spin_lock(&mctz
->lock
);
4737 * If we failed to reclaim anything from this memory cgroup
4738 * it is time to move on to the next cgroup
4744 * Loop until we find yet another one.
4746 * By the time we get the soft_limit lock
4747 * again, someone might have aded the
4748 * group back on the RB tree. Iterate to
4749 * make sure we get a different mem.
4750 * mem_cgroup_largest_soft_limit_node returns
4751 * NULL if no other cgroup is present on
4755 __mem_cgroup_largest_soft_limit_node(mctz
);
4757 css_put(&next_mz
->memcg
->css
);
4758 else /* next_mz == NULL or other memcg */
4762 __mem_cgroup_remove_exceeded(mz
->memcg
, mz
, mctz
);
4763 excess
= res_counter_soft_limit_excess(&mz
->memcg
->res
);
4765 * One school of thought says that we should not add
4766 * back the node to the tree if reclaim returns 0.
4767 * But our reclaim could return 0, simply because due
4768 * to priority we are exposing a smaller subset of
4769 * memory to reclaim from. Consider this as a longer
4772 /* If excess == 0, no tree ops */
4773 __mem_cgroup_insert_exceeded(mz
->memcg
, mz
, mctz
, excess
);
4774 spin_unlock(&mctz
->lock
);
4775 css_put(&mz
->memcg
->css
);
4778 * Could not reclaim anything and there are no more
4779 * mem cgroups to try or we seem to be looping without
4780 * reclaiming anything.
4782 if (!nr_reclaimed
&&
4784 loop
> MEM_CGROUP_MAX_SOFT_LIMIT_RECLAIM_LOOPS
))
4786 } while (!nr_reclaimed
);
4788 css_put(&next_mz
->memcg
->css
);
4789 return nr_reclaimed
;
4793 * mem_cgroup_force_empty_list - clears LRU of a group
4794 * @memcg: group to clear
4797 * @lru: lru to to clear
4799 * Traverse a specified page_cgroup list and try to drop them all. This doesn't
4800 * reclaim the pages page themselves - pages are moved to the parent (or root)
4803 static void mem_cgroup_force_empty_list(struct mem_cgroup
*memcg
,
4804 int node
, int zid
, enum lru_list lru
)
4806 struct lruvec
*lruvec
;
4807 unsigned long flags
;
4808 struct list_head
*list
;
4812 zone
= &NODE_DATA(node
)->node_zones
[zid
];
4813 lruvec
= mem_cgroup_zone_lruvec(zone
, memcg
);
4814 list
= &lruvec
->lists
[lru
];
4818 struct page_cgroup
*pc
;
4821 spin_lock_irqsave(&zone
->lru_lock
, flags
);
4822 if (list_empty(list
)) {
4823 spin_unlock_irqrestore(&zone
->lru_lock
, flags
);
4826 page
= list_entry(list
->prev
, struct page
, lru
);
4828 list_move(&page
->lru
, list
);
4830 spin_unlock_irqrestore(&zone
->lru_lock
, flags
);
4833 spin_unlock_irqrestore(&zone
->lru_lock
, flags
);
4835 pc
= lookup_page_cgroup(page
);
4837 if (mem_cgroup_move_parent(page
, pc
, memcg
)) {
4838 /* found lock contention or "pc" is obsolete. */
4843 } while (!list_empty(list
));
4847 * make mem_cgroup's charge to be 0 if there is no task by moving
4848 * all the charges and pages to the parent.
4849 * This enables deleting this mem_cgroup.
4851 * Caller is responsible for holding css reference on the memcg.
4853 static void mem_cgroup_reparent_charges(struct mem_cgroup
*memcg
)
4859 /* This is for making all *used* pages to be on LRU. */
4860 lru_add_drain_all();
4861 drain_all_stock_sync(memcg
);
4862 mem_cgroup_start_move(memcg
);
4863 for_each_node_state(node
, N_MEMORY
) {
4864 for (zid
= 0; zid
< MAX_NR_ZONES
; zid
++) {
4867 mem_cgroup_force_empty_list(memcg
,
4872 mem_cgroup_end_move(memcg
);
4873 memcg_oom_recover(memcg
);
4877 * Kernel memory may not necessarily be trackable to a specific
4878 * process. So they are not migrated, and therefore we can't
4879 * expect their value to drop to 0 here.
4880 * Having res filled up with kmem only is enough.
4882 * This is a safety check because mem_cgroup_force_empty_list
4883 * could have raced with mem_cgroup_replace_page_cache callers
4884 * so the lru seemed empty but the page could have been added
4885 * right after the check. RES_USAGE should be safe as we always
4886 * charge before adding to the LRU.
4888 usage
= res_counter_read_u64(&memcg
->res
, RES_USAGE
) -
4889 res_counter_read_u64(&memcg
->kmem
, RES_USAGE
);
4890 } while (usage
> 0);
4894 * This mainly exists for tests during the setting of set of use_hierarchy.
4895 * Since this is the very setting we are changing, the current hierarchy value
4898 static inline bool __memcg_has_children(struct mem_cgroup
*memcg
)
4902 /* bounce at first found */
4903 cgroup_for_each_child(pos
, memcg
->css
.cgroup
)
4909 * Must be called with memcg_create_mutex held, unless the cgroup is guaranteed
4910 * to be already dead (as in mem_cgroup_force_empty, for instance). This is
4911 * from mem_cgroup_count_children(), in the sense that we don't really care how
4912 * many children we have; we only need to know if we have any. It also counts
4913 * any memcg without hierarchy as infertile.
4915 static inline bool memcg_has_children(struct mem_cgroup
*memcg
)
4917 return memcg
->use_hierarchy
&& __memcg_has_children(memcg
);
4921 * Reclaims as many pages from the given memcg as possible and moves
4922 * the rest to the parent.
4924 * Caller is responsible for holding css reference for memcg.
4926 static int mem_cgroup_force_empty(struct mem_cgroup
*memcg
)
4928 int nr_retries
= MEM_CGROUP_RECLAIM_RETRIES
;
4929 struct cgroup
*cgrp
= memcg
->css
.cgroup
;
4931 /* returns EBUSY if there is a task or if we come here twice. */
4932 if (cgroup_task_count(cgrp
) || !list_empty(&cgrp
->children
))
4935 /* we call try-to-free pages for make this cgroup empty */
4936 lru_add_drain_all();
4937 /* try to free all pages in this cgroup */
4938 while (nr_retries
&& res_counter_read_u64(&memcg
->res
, RES_USAGE
) > 0) {
4941 if (signal_pending(current
))
4944 progress
= try_to_free_mem_cgroup_pages(memcg
, GFP_KERNEL
,
4948 /* maybe some writeback is necessary */
4949 congestion_wait(BLK_RW_ASYNC
, HZ
/10);
4954 mem_cgroup_reparent_charges(memcg
);
4959 static int mem_cgroup_force_empty_write(struct cgroup
*cont
, unsigned int event
)
4961 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cont
);
4964 if (mem_cgroup_is_root(memcg
))
4966 css_get(&memcg
->css
);
4967 ret
= mem_cgroup_force_empty(memcg
);
4968 css_put(&memcg
->css
);
4974 static u64
mem_cgroup_hierarchy_read(struct cgroup
*cont
, struct cftype
*cft
)
4976 return mem_cgroup_from_cont(cont
)->use_hierarchy
;
4979 static int mem_cgroup_hierarchy_write(struct cgroup
*cont
, struct cftype
*cft
,
4983 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cont
);
4984 struct cgroup
*parent
= cont
->parent
;
4985 struct mem_cgroup
*parent_memcg
= NULL
;
4988 parent_memcg
= mem_cgroup_from_cont(parent
);
4990 mutex_lock(&memcg_create_mutex
);
4992 if (memcg
->use_hierarchy
== val
)
4996 * If parent's use_hierarchy is set, we can't make any modifications
4997 * in the child subtrees. If it is unset, then the change can
4998 * occur, provided the current cgroup has no children.
5000 * For the root cgroup, parent_mem is NULL, we allow value to be
5001 * set if there are no children.
5003 if ((!parent_memcg
|| !parent_memcg
->use_hierarchy
) &&
5004 (val
== 1 || val
== 0)) {
5005 if (!__memcg_has_children(memcg
))
5006 memcg
->use_hierarchy
= val
;
5013 mutex_unlock(&memcg_create_mutex
);
5019 static unsigned long mem_cgroup_recursive_stat(struct mem_cgroup
*memcg
,
5020 enum mem_cgroup_stat_index idx
)
5022 struct mem_cgroup
*iter
;
5025 /* Per-cpu values can be negative, use a signed accumulator */
5026 for_each_mem_cgroup_tree(iter
, memcg
)
5027 val
+= mem_cgroup_read_stat(iter
, idx
);
5029 if (val
< 0) /* race ? */
5034 static inline u64
mem_cgroup_usage(struct mem_cgroup
*memcg
, bool swap
)
5038 if (!mem_cgroup_is_root(memcg
)) {
5040 return res_counter_read_u64(&memcg
->res
, RES_USAGE
);
5042 return res_counter_read_u64(&memcg
->memsw
, RES_USAGE
);
5046 * Transparent hugepages are still accounted for in MEM_CGROUP_STAT_RSS
5047 * as well as in MEM_CGROUP_STAT_RSS_HUGE.
5049 val
= mem_cgroup_recursive_stat(memcg
, MEM_CGROUP_STAT_CACHE
);
5050 val
+= mem_cgroup_recursive_stat(memcg
, MEM_CGROUP_STAT_RSS
);
5053 val
+= mem_cgroup_recursive_stat(memcg
, MEM_CGROUP_STAT_SWAP
);
5055 return val
<< PAGE_SHIFT
;
5058 static ssize_t
mem_cgroup_read(struct cgroup
*cont
, struct cftype
*cft
,
5059 struct file
*file
, char __user
*buf
,
5060 size_t nbytes
, loff_t
*ppos
)
5062 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cont
);
5068 type
= MEMFILE_TYPE(cft
->private);
5069 name
= MEMFILE_ATTR(cft
->private);
5073 if (name
== RES_USAGE
)
5074 val
= mem_cgroup_usage(memcg
, false);
5076 val
= res_counter_read_u64(&memcg
->res
, name
);
5079 if (name
== RES_USAGE
)
5080 val
= mem_cgroup_usage(memcg
, true);
5082 val
= res_counter_read_u64(&memcg
->memsw
, name
);
5085 val
= res_counter_read_u64(&memcg
->kmem
, name
);
5091 len
= scnprintf(str
, sizeof(str
), "%llu\n", (unsigned long long)val
);
5092 return simple_read_from_buffer(buf
, nbytes
, ppos
, str
, len
);
5095 static int memcg_update_kmem_limit(struct cgroup
*cont
, u64 val
)
5098 #ifdef CONFIG_MEMCG_KMEM
5099 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cont
);
5101 * For simplicity, we won't allow this to be disabled. It also can't
5102 * be changed if the cgroup has children already, or if tasks had
5105 * If tasks join before we set the limit, a person looking at
5106 * kmem.usage_in_bytes will have no way to determine when it took
5107 * place, which makes the value quite meaningless.
5109 * After it first became limited, changes in the value of the limit are
5110 * of course permitted.
5112 mutex_lock(&memcg_create_mutex
);
5113 mutex_lock(&set_limit_mutex
);
5114 if (!memcg
->kmem_account_flags
&& val
!= RESOURCE_MAX
) {
5115 if (cgroup_task_count(cont
) || memcg_has_children(memcg
)) {
5119 ret
= res_counter_set_limit(&memcg
->kmem
, val
);
5122 ret
= memcg_update_cache_sizes(memcg
);
5124 res_counter_set_limit(&memcg
->kmem
, RESOURCE_MAX
);
5127 static_key_slow_inc(&memcg_kmem_enabled_key
);
5129 * setting the active bit after the inc will guarantee no one
5130 * starts accounting before all call sites are patched
5132 memcg_kmem_set_active(memcg
);
5135 * kmem charges can outlive the cgroup. In the case of slab
5136 * pages, for instance, a page contain objects from various
5137 * processes, so it is unfeasible to migrate them away. We
5138 * need to reference count the memcg because of that.
5140 mem_cgroup_get(memcg
);
5142 ret
= res_counter_set_limit(&memcg
->kmem
, val
);
5144 mutex_unlock(&set_limit_mutex
);
5145 mutex_unlock(&memcg_create_mutex
);
5150 #ifdef CONFIG_MEMCG_KMEM
5151 static int memcg_propagate_kmem(struct mem_cgroup
*memcg
)
5154 struct mem_cgroup
*parent
= parent_mem_cgroup(memcg
);
5158 memcg
->kmem_account_flags
= parent
->kmem_account_flags
;
5160 * When that happen, we need to disable the static branch only on those
5161 * memcgs that enabled it. To achieve this, we would be forced to
5162 * complicate the code by keeping track of which memcgs were the ones
5163 * that actually enabled limits, and which ones got it from its
5166 * It is a lot simpler just to do static_key_slow_inc() on every child
5167 * that is accounted.
5169 if (!memcg_kmem_is_active(memcg
))
5173 * destroy(), called if we fail, will issue static_key_slow_inc() and
5174 * mem_cgroup_put() if kmem is enabled. We have to either call them
5175 * unconditionally, or clear the KMEM_ACTIVE flag. I personally find
5176 * this more consistent, since it always leads to the same destroy path
5178 mem_cgroup_get(memcg
);
5179 static_key_slow_inc(&memcg_kmem_enabled_key
);
5181 mutex_lock(&set_limit_mutex
);
5182 ret
= memcg_update_cache_sizes(memcg
);
5183 mutex_unlock(&set_limit_mutex
);
5187 #endif /* CONFIG_MEMCG_KMEM */
5190 * The user of this function is...
5193 static int mem_cgroup_write(struct cgroup
*cont
, struct cftype
*cft
,
5196 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cont
);
5199 unsigned long long val
;
5202 type
= MEMFILE_TYPE(cft
->private);
5203 name
= MEMFILE_ATTR(cft
->private);
5207 if (mem_cgroup_is_root(memcg
)) { /* Can't set limit on root */
5211 /* This function does all necessary parse...reuse it */
5212 ret
= res_counter_memparse_write_strategy(buffer
, &val
);
5216 ret
= mem_cgroup_resize_limit(memcg
, val
);
5217 else if (type
== _MEMSWAP
)
5218 ret
= mem_cgroup_resize_memsw_limit(memcg
, val
);
5219 else if (type
== _KMEM
)
5220 ret
= memcg_update_kmem_limit(cont
, val
);
5224 case RES_SOFT_LIMIT
:
5225 ret
= res_counter_memparse_write_strategy(buffer
, &val
);
5229 * For memsw, soft limits are hard to implement in terms
5230 * of semantics, for now, we support soft limits for
5231 * control without swap
5234 ret
= res_counter_set_soft_limit(&memcg
->res
, val
);
5239 ret
= -EINVAL
; /* should be BUG() ? */
5245 static void memcg_get_hierarchical_limit(struct mem_cgroup
*memcg
,
5246 unsigned long long *mem_limit
, unsigned long long *memsw_limit
)
5248 struct cgroup
*cgroup
;
5249 unsigned long long min_limit
, min_memsw_limit
, tmp
;
5251 min_limit
= res_counter_read_u64(&memcg
->res
, RES_LIMIT
);
5252 min_memsw_limit
= res_counter_read_u64(&memcg
->memsw
, RES_LIMIT
);
5253 cgroup
= memcg
->css
.cgroup
;
5254 if (!memcg
->use_hierarchy
)
5257 while (cgroup
->parent
) {
5258 cgroup
= cgroup
->parent
;
5259 memcg
= mem_cgroup_from_cont(cgroup
);
5260 if (!memcg
->use_hierarchy
)
5262 tmp
= res_counter_read_u64(&memcg
->res
, RES_LIMIT
);
5263 min_limit
= min(min_limit
, tmp
);
5264 tmp
= res_counter_read_u64(&memcg
->memsw
, RES_LIMIT
);
5265 min_memsw_limit
= min(min_memsw_limit
, tmp
);
5268 *mem_limit
= min_limit
;
5269 *memsw_limit
= min_memsw_limit
;
5272 static int mem_cgroup_reset(struct cgroup
*cont
, unsigned int event
)
5274 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cont
);
5278 type
= MEMFILE_TYPE(event
);
5279 name
= MEMFILE_ATTR(event
);
5284 res_counter_reset_max(&memcg
->res
);
5285 else if (type
== _MEMSWAP
)
5286 res_counter_reset_max(&memcg
->memsw
);
5287 else if (type
== _KMEM
)
5288 res_counter_reset_max(&memcg
->kmem
);
5294 res_counter_reset_failcnt(&memcg
->res
);
5295 else if (type
== _MEMSWAP
)
5296 res_counter_reset_failcnt(&memcg
->memsw
);
5297 else if (type
== _KMEM
)
5298 res_counter_reset_failcnt(&memcg
->kmem
);
5307 static u64
mem_cgroup_move_charge_read(struct cgroup
*cgrp
,
5310 return mem_cgroup_from_cont(cgrp
)->move_charge_at_immigrate
;
5314 static int mem_cgroup_move_charge_write(struct cgroup
*cgrp
,
5315 struct cftype
*cft
, u64 val
)
5317 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cgrp
);
5319 if (val
>= (1 << NR_MOVE_TYPE
))
5323 * No kind of locking is needed in here, because ->can_attach() will
5324 * check this value once in the beginning of the process, and then carry
5325 * on with stale data. This means that changes to this value will only
5326 * affect task migrations starting after the change.
5328 memcg
->move_charge_at_immigrate
= val
;
5332 static int mem_cgroup_move_charge_write(struct cgroup
*cgrp
,
5333 struct cftype
*cft
, u64 val
)
5340 static int memcg_numa_stat_show(struct cgroup
*cont
, struct cftype
*cft
,
5344 unsigned long total_nr
, file_nr
, anon_nr
, unevictable_nr
;
5345 unsigned long node_nr
;
5346 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cont
);
5348 total_nr
= mem_cgroup_nr_lru_pages(memcg
, LRU_ALL
);
5349 seq_printf(m
, "total=%lu", total_nr
);
5350 for_each_node_state(nid
, N_MEMORY
) {
5351 node_nr
= mem_cgroup_node_nr_lru_pages(memcg
, nid
, LRU_ALL
);
5352 seq_printf(m
, " N%d=%lu", nid
, node_nr
);
5356 file_nr
= mem_cgroup_nr_lru_pages(memcg
, LRU_ALL_FILE
);
5357 seq_printf(m
, "file=%lu", file_nr
);
5358 for_each_node_state(nid
, N_MEMORY
) {
5359 node_nr
= mem_cgroup_node_nr_lru_pages(memcg
, nid
,
5361 seq_printf(m
, " N%d=%lu", nid
, node_nr
);
5365 anon_nr
= mem_cgroup_nr_lru_pages(memcg
, LRU_ALL_ANON
);
5366 seq_printf(m
, "anon=%lu", anon_nr
);
5367 for_each_node_state(nid
, N_MEMORY
) {
5368 node_nr
= mem_cgroup_node_nr_lru_pages(memcg
, nid
,
5370 seq_printf(m
, " N%d=%lu", nid
, node_nr
);
5374 unevictable_nr
= mem_cgroup_nr_lru_pages(memcg
, BIT(LRU_UNEVICTABLE
));
5375 seq_printf(m
, "unevictable=%lu", unevictable_nr
);
5376 for_each_node_state(nid
, N_MEMORY
) {
5377 node_nr
= mem_cgroup_node_nr_lru_pages(memcg
, nid
,
5378 BIT(LRU_UNEVICTABLE
));
5379 seq_printf(m
, " N%d=%lu", nid
, node_nr
);
5384 #endif /* CONFIG_NUMA */
5386 static inline void mem_cgroup_lru_names_not_uptodate(void)
5388 BUILD_BUG_ON(ARRAY_SIZE(mem_cgroup_lru_names
) != NR_LRU_LISTS
);
5391 static int memcg_stat_show(struct cgroup
*cont
, struct cftype
*cft
,
5394 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cont
);
5395 struct mem_cgroup
*mi
;
5398 for (i
= 0; i
< MEM_CGROUP_STAT_NSTATS
; i
++) {
5399 if (i
== MEM_CGROUP_STAT_SWAP
&& !do_swap_account
)
5401 seq_printf(m
, "%s %ld\n", mem_cgroup_stat_names
[i
],
5402 mem_cgroup_read_stat(memcg
, i
) * PAGE_SIZE
);
5405 for (i
= 0; i
< MEM_CGROUP_EVENTS_NSTATS
; i
++)
5406 seq_printf(m
, "%s %lu\n", mem_cgroup_events_names
[i
],
5407 mem_cgroup_read_events(memcg
, i
));
5409 for (i
= 0; i
< NR_LRU_LISTS
; i
++)
5410 seq_printf(m
, "%s %lu\n", mem_cgroup_lru_names
[i
],
5411 mem_cgroup_nr_lru_pages(memcg
, BIT(i
)) * PAGE_SIZE
);
5413 /* Hierarchical information */
5415 unsigned long long limit
, memsw_limit
;
5416 memcg_get_hierarchical_limit(memcg
, &limit
, &memsw_limit
);
5417 seq_printf(m
, "hierarchical_memory_limit %llu\n", limit
);
5418 if (do_swap_account
)
5419 seq_printf(m
, "hierarchical_memsw_limit %llu\n",
5423 for (i
= 0; i
< MEM_CGROUP_STAT_NSTATS
; i
++) {
5426 if (i
== MEM_CGROUP_STAT_SWAP
&& !do_swap_account
)
5428 for_each_mem_cgroup_tree(mi
, memcg
)
5429 val
+= mem_cgroup_read_stat(mi
, i
) * PAGE_SIZE
;
5430 seq_printf(m
, "total_%s %lld\n", mem_cgroup_stat_names
[i
], val
);
5433 for (i
= 0; i
< MEM_CGROUP_EVENTS_NSTATS
; i
++) {
5434 unsigned long long val
= 0;
5436 for_each_mem_cgroup_tree(mi
, memcg
)
5437 val
+= mem_cgroup_read_events(mi
, i
);
5438 seq_printf(m
, "total_%s %llu\n",
5439 mem_cgroup_events_names
[i
], val
);
5442 for (i
= 0; i
< NR_LRU_LISTS
; i
++) {
5443 unsigned long long val
= 0;
5445 for_each_mem_cgroup_tree(mi
, memcg
)
5446 val
+= mem_cgroup_nr_lru_pages(mi
, BIT(i
)) * PAGE_SIZE
;
5447 seq_printf(m
, "total_%s %llu\n", mem_cgroup_lru_names
[i
], val
);
5450 #ifdef CONFIG_DEBUG_VM
5453 struct mem_cgroup_per_zone
*mz
;
5454 struct zone_reclaim_stat
*rstat
;
5455 unsigned long recent_rotated
[2] = {0, 0};
5456 unsigned long recent_scanned
[2] = {0, 0};
5458 for_each_online_node(nid
)
5459 for (zid
= 0; zid
< MAX_NR_ZONES
; zid
++) {
5460 mz
= mem_cgroup_zoneinfo(memcg
, nid
, zid
);
5461 rstat
= &mz
->lruvec
.reclaim_stat
;
5463 recent_rotated
[0] += rstat
->recent_rotated
[0];
5464 recent_rotated
[1] += rstat
->recent_rotated
[1];
5465 recent_scanned
[0] += rstat
->recent_scanned
[0];
5466 recent_scanned
[1] += rstat
->recent_scanned
[1];
5468 seq_printf(m
, "recent_rotated_anon %lu\n", recent_rotated
[0]);
5469 seq_printf(m
, "recent_rotated_file %lu\n", recent_rotated
[1]);
5470 seq_printf(m
, "recent_scanned_anon %lu\n", recent_scanned
[0]);
5471 seq_printf(m
, "recent_scanned_file %lu\n", recent_scanned
[1]);
5478 static u64
mem_cgroup_swappiness_read(struct cgroup
*cgrp
, struct cftype
*cft
)
5480 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cgrp
);
5482 return mem_cgroup_swappiness(memcg
);
5485 static int mem_cgroup_swappiness_write(struct cgroup
*cgrp
, struct cftype
*cft
,
5488 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cgrp
);
5489 struct mem_cgroup
*parent
;
5494 if (cgrp
->parent
== NULL
)
5497 parent
= mem_cgroup_from_cont(cgrp
->parent
);
5499 mutex_lock(&memcg_create_mutex
);
5501 /* If under hierarchy, only empty-root can set this value */
5502 if ((parent
->use_hierarchy
) || memcg_has_children(memcg
)) {
5503 mutex_unlock(&memcg_create_mutex
);
5507 memcg
->swappiness
= val
;
5509 mutex_unlock(&memcg_create_mutex
);
5514 static void __mem_cgroup_threshold(struct mem_cgroup
*memcg
, bool swap
)
5516 struct mem_cgroup_threshold_ary
*t
;
5522 t
= rcu_dereference(memcg
->thresholds
.primary
);
5524 t
= rcu_dereference(memcg
->memsw_thresholds
.primary
);
5529 usage
= mem_cgroup_usage(memcg
, swap
);
5532 * current_threshold points to threshold just below or equal to usage.
5533 * If it's not true, a threshold was crossed after last
5534 * call of __mem_cgroup_threshold().
5536 i
= t
->current_threshold
;
5539 * Iterate backward over array of thresholds starting from
5540 * current_threshold and check if a threshold is crossed.
5541 * If none of thresholds below usage is crossed, we read
5542 * only one element of the array here.
5544 for (; i
>= 0 && unlikely(t
->entries
[i
].threshold
> usage
); i
--)
5545 eventfd_signal(t
->entries
[i
].eventfd
, 1);
5547 /* i = current_threshold + 1 */
5551 * Iterate forward over array of thresholds starting from
5552 * current_threshold+1 and check if a threshold is crossed.
5553 * If none of thresholds above usage is crossed, we read
5554 * only one element of the array here.
5556 for (; i
< t
->size
&& unlikely(t
->entries
[i
].threshold
<= usage
); i
++)
5557 eventfd_signal(t
->entries
[i
].eventfd
, 1);
5559 /* Update current_threshold */
5560 t
->current_threshold
= i
- 1;
5565 static void mem_cgroup_threshold(struct mem_cgroup
*memcg
)
5568 __mem_cgroup_threshold(memcg
, false);
5569 if (do_swap_account
)
5570 __mem_cgroup_threshold(memcg
, true);
5572 memcg
= parent_mem_cgroup(memcg
);
5576 static int compare_thresholds(const void *a
, const void *b
)
5578 const struct mem_cgroup_threshold
*_a
= a
;
5579 const struct mem_cgroup_threshold
*_b
= b
;
5581 return _a
->threshold
- _b
->threshold
;
5584 static int mem_cgroup_oom_notify_cb(struct mem_cgroup
*memcg
)
5586 struct mem_cgroup_eventfd_list
*ev
;
5588 list_for_each_entry(ev
, &memcg
->oom_notify
, list
)
5589 eventfd_signal(ev
->eventfd
, 1);
5593 static void mem_cgroup_oom_notify(struct mem_cgroup
*memcg
)
5595 struct mem_cgroup
*iter
;
5597 for_each_mem_cgroup_tree(iter
, memcg
)
5598 mem_cgroup_oom_notify_cb(iter
);
5601 static int mem_cgroup_usage_register_event(struct cgroup
*cgrp
,
5602 struct cftype
*cft
, struct eventfd_ctx
*eventfd
, const char *args
)
5604 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cgrp
);
5605 struct mem_cgroup_thresholds
*thresholds
;
5606 struct mem_cgroup_threshold_ary
*new;
5607 enum res_type type
= MEMFILE_TYPE(cft
->private);
5608 u64 threshold
, usage
;
5611 ret
= res_counter_memparse_write_strategy(args
, &threshold
);
5615 mutex_lock(&memcg
->thresholds_lock
);
5618 thresholds
= &memcg
->thresholds
;
5619 else if (type
== _MEMSWAP
)
5620 thresholds
= &memcg
->memsw_thresholds
;
5624 usage
= mem_cgroup_usage(memcg
, type
== _MEMSWAP
);
5626 /* Check if a threshold crossed before adding a new one */
5627 if (thresholds
->primary
)
5628 __mem_cgroup_threshold(memcg
, type
== _MEMSWAP
);
5630 size
= thresholds
->primary
? thresholds
->primary
->size
+ 1 : 1;
5632 /* Allocate memory for new array of thresholds */
5633 new = kmalloc(sizeof(*new) + size
* sizeof(struct mem_cgroup_threshold
),
5641 /* Copy thresholds (if any) to new array */
5642 if (thresholds
->primary
) {
5643 memcpy(new->entries
, thresholds
->primary
->entries
, (size
- 1) *
5644 sizeof(struct mem_cgroup_threshold
));
5647 /* Add new threshold */
5648 new->entries
[size
- 1].eventfd
= eventfd
;
5649 new->entries
[size
- 1].threshold
= threshold
;
5651 /* Sort thresholds. Registering of new threshold isn't time-critical */
5652 sort(new->entries
, size
, sizeof(struct mem_cgroup_threshold
),
5653 compare_thresholds
, NULL
);
5655 /* Find current threshold */
5656 new->current_threshold
= -1;
5657 for (i
= 0; i
< size
; i
++) {
5658 if (new->entries
[i
].threshold
<= usage
) {
5660 * new->current_threshold will not be used until
5661 * rcu_assign_pointer(), so it's safe to increment
5664 ++new->current_threshold
;
5669 /* Free old spare buffer and save old primary buffer as spare */
5670 kfree(thresholds
->spare
);
5671 thresholds
->spare
= thresholds
->primary
;
5673 rcu_assign_pointer(thresholds
->primary
, new);
5675 /* To be sure that nobody uses thresholds */
5679 mutex_unlock(&memcg
->thresholds_lock
);
5684 static void mem_cgroup_usage_unregister_event(struct cgroup
*cgrp
,
5685 struct cftype
*cft
, struct eventfd_ctx
*eventfd
)
5687 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cgrp
);
5688 struct mem_cgroup_thresholds
*thresholds
;
5689 struct mem_cgroup_threshold_ary
*new;
5690 enum res_type type
= MEMFILE_TYPE(cft
->private);
5694 mutex_lock(&memcg
->thresholds_lock
);
5696 thresholds
= &memcg
->thresholds
;
5697 else if (type
== _MEMSWAP
)
5698 thresholds
= &memcg
->memsw_thresholds
;
5702 if (!thresholds
->primary
)
5705 usage
= mem_cgroup_usage(memcg
, type
== _MEMSWAP
);
5707 /* Check if a threshold crossed before removing */
5708 __mem_cgroup_threshold(memcg
, type
== _MEMSWAP
);
5710 /* Calculate new number of threshold */
5712 for (i
= 0; i
< thresholds
->primary
->size
; i
++) {
5713 if (thresholds
->primary
->entries
[i
].eventfd
!= eventfd
)
5717 new = thresholds
->spare
;
5719 /* Set thresholds array to NULL if we don't have thresholds */
5728 /* Copy thresholds and find current threshold */
5729 new->current_threshold
= -1;
5730 for (i
= 0, j
= 0; i
< thresholds
->primary
->size
; i
++) {
5731 if (thresholds
->primary
->entries
[i
].eventfd
== eventfd
)
5734 new->entries
[j
] = thresholds
->primary
->entries
[i
];
5735 if (new->entries
[j
].threshold
<= usage
) {
5737 * new->current_threshold will not be used
5738 * until rcu_assign_pointer(), so it's safe to increment
5741 ++new->current_threshold
;
5747 /* Swap primary and spare array */
5748 thresholds
->spare
= thresholds
->primary
;
5749 /* If all events are unregistered, free the spare array */
5751 kfree(thresholds
->spare
);
5752 thresholds
->spare
= NULL
;
5755 rcu_assign_pointer(thresholds
->primary
, new);
5757 /* To be sure that nobody uses thresholds */
5760 mutex_unlock(&memcg
->thresholds_lock
);
5763 static int mem_cgroup_oom_register_event(struct cgroup
*cgrp
,
5764 struct cftype
*cft
, struct eventfd_ctx
*eventfd
, const char *args
)
5766 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cgrp
);
5767 struct mem_cgroup_eventfd_list
*event
;
5768 enum res_type type
= MEMFILE_TYPE(cft
->private);
5770 BUG_ON(type
!= _OOM_TYPE
);
5771 event
= kmalloc(sizeof(*event
), GFP_KERNEL
);
5775 spin_lock(&memcg_oom_lock
);
5777 event
->eventfd
= eventfd
;
5778 list_add(&event
->list
, &memcg
->oom_notify
);
5780 /* already in OOM ? */
5781 if (atomic_read(&memcg
->under_oom
))
5782 eventfd_signal(eventfd
, 1);
5783 spin_unlock(&memcg_oom_lock
);
5788 static void mem_cgroup_oom_unregister_event(struct cgroup
*cgrp
,
5789 struct cftype
*cft
, struct eventfd_ctx
*eventfd
)
5791 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cgrp
);
5792 struct mem_cgroup_eventfd_list
*ev
, *tmp
;
5793 enum res_type type
= MEMFILE_TYPE(cft
->private);
5795 BUG_ON(type
!= _OOM_TYPE
);
5797 spin_lock(&memcg_oom_lock
);
5799 list_for_each_entry_safe(ev
, tmp
, &memcg
->oom_notify
, list
) {
5800 if (ev
->eventfd
== eventfd
) {
5801 list_del(&ev
->list
);
5806 spin_unlock(&memcg_oom_lock
);
5809 static int mem_cgroup_oom_control_read(struct cgroup
*cgrp
,
5810 struct cftype
*cft
, struct cgroup_map_cb
*cb
)
5812 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cgrp
);
5814 cb
->fill(cb
, "oom_kill_disable", memcg
->oom_kill_disable
);
5816 if (atomic_read(&memcg
->under_oom
))
5817 cb
->fill(cb
, "under_oom", 1);
5819 cb
->fill(cb
, "under_oom", 0);
5823 static int mem_cgroup_oom_control_write(struct cgroup
*cgrp
,
5824 struct cftype
*cft
, u64 val
)
5826 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cgrp
);
5827 struct mem_cgroup
*parent
;
5829 /* cannot set to root cgroup and only 0 and 1 are allowed */
5830 if (!cgrp
->parent
|| !((val
== 0) || (val
== 1)))
5833 parent
= mem_cgroup_from_cont(cgrp
->parent
);
5835 mutex_lock(&memcg_create_mutex
);
5836 /* oom-kill-disable is a flag for subhierarchy. */
5837 if ((parent
->use_hierarchy
) || memcg_has_children(memcg
)) {
5838 mutex_unlock(&memcg_create_mutex
);
5841 memcg
->oom_kill_disable
= val
;
5843 memcg_oom_recover(memcg
);
5844 mutex_unlock(&memcg_create_mutex
);
5848 #ifdef CONFIG_MEMCG_KMEM
5849 static int memcg_init_kmem(struct mem_cgroup
*memcg
, struct cgroup_subsys
*ss
)
5853 memcg
->kmemcg_id
= -1;
5854 ret
= memcg_propagate_kmem(memcg
);
5858 return mem_cgroup_sockets_init(memcg
, ss
);
5861 static void kmem_cgroup_destroy(struct mem_cgroup
*memcg
)
5863 mem_cgroup_sockets_destroy(memcg
);
5865 memcg_kmem_mark_dead(memcg
);
5867 if (res_counter_read_u64(&memcg
->kmem
, RES_USAGE
) != 0)
5871 * Charges already down to 0, undo mem_cgroup_get() done in the charge
5872 * path here, being careful not to race with memcg_uncharge_kmem: it is
5873 * possible that the charges went down to 0 between mark_dead and the
5874 * res_counter read, so in that case, we don't need the put
5876 if (memcg_kmem_test_and_clear_dead(memcg
))
5877 mem_cgroup_put(memcg
);
5880 static int memcg_init_kmem(struct mem_cgroup
*memcg
, struct cgroup_subsys
*ss
)
5885 static void kmem_cgroup_destroy(struct mem_cgroup
*memcg
)
5890 static struct cftype mem_cgroup_files
[] = {
5892 .name
= "usage_in_bytes",
5893 .private = MEMFILE_PRIVATE(_MEM
, RES_USAGE
),
5894 .read
= mem_cgroup_read
,
5895 .register_event
= mem_cgroup_usage_register_event
,
5896 .unregister_event
= mem_cgroup_usage_unregister_event
,
5899 .name
= "max_usage_in_bytes",
5900 .private = MEMFILE_PRIVATE(_MEM
, RES_MAX_USAGE
),
5901 .trigger
= mem_cgroup_reset
,
5902 .read
= mem_cgroup_read
,
5905 .name
= "limit_in_bytes",
5906 .private = MEMFILE_PRIVATE(_MEM
, RES_LIMIT
),
5907 .write_string
= mem_cgroup_write
,
5908 .read
= mem_cgroup_read
,
5911 .name
= "soft_limit_in_bytes",
5912 .private = MEMFILE_PRIVATE(_MEM
, RES_SOFT_LIMIT
),
5913 .write_string
= mem_cgroup_write
,
5914 .read
= mem_cgroup_read
,
5918 .private = MEMFILE_PRIVATE(_MEM
, RES_FAILCNT
),
5919 .trigger
= mem_cgroup_reset
,
5920 .read
= mem_cgroup_read
,
5924 .read_seq_string
= memcg_stat_show
,
5927 .name
= "force_empty",
5928 .trigger
= mem_cgroup_force_empty_write
,
5931 .name
= "use_hierarchy",
5932 .flags
= CFTYPE_INSANE
,
5933 .write_u64
= mem_cgroup_hierarchy_write
,
5934 .read_u64
= mem_cgroup_hierarchy_read
,
5937 .name
= "swappiness",
5938 .read_u64
= mem_cgroup_swappiness_read
,
5939 .write_u64
= mem_cgroup_swappiness_write
,
5942 .name
= "move_charge_at_immigrate",
5943 .read_u64
= mem_cgroup_move_charge_read
,
5944 .write_u64
= mem_cgroup_move_charge_write
,
5947 .name
= "oom_control",
5948 .read_map
= mem_cgroup_oom_control_read
,
5949 .write_u64
= mem_cgroup_oom_control_write
,
5950 .register_event
= mem_cgroup_oom_register_event
,
5951 .unregister_event
= mem_cgroup_oom_unregister_event
,
5952 .private = MEMFILE_PRIVATE(_OOM_TYPE
, OOM_CONTROL
),
5955 .name
= "pressure_level",
5956 .register_event
= vmpressure_register_event
,
5957 .unregister_event
= vmpressure_unregister_event
,
5961 .name
= "numa_stat",
5962 .read_seq_string
= memcg_numa_stat_show
,
5965 #ifdef CONFIG_MEMCG_KMEM
5967 .name
= "kmem.limit_in_bytes",
5968 .private = MEMFILE_PRIVATE(_KMEM
, RES_LIMIT
),
5969 .write_string
= mem_cgroup_write
,
5970 .read
= mem_cgroup_read
,
5973 .name
= "kmem.usage_in_bytes",
5974 .private = MEMFILE_PRIVATE(_KMEM
, RES_USAGE
),
5975 .read
= mem_cgroup_read
,
5978 .name
= "kmem.failcnt",
5979 .private = MEMFILE_PRIVATE(_KMEM
, RES_FAILCNT
),
5980 .trigger
= mem_cgroup_reset
,
5981 .read
= mem_cgroup_read
,
5984 .name
= "kmem.max_usage_in_bytes",
5985 .private = MEMFILE_PRIVATE(_KMEM
, RES_MAX_USAGE
),
5986 .trigger
= mem_cgroup_reset
,
5987 .read
= mem_cgroup_read
,
5989 #ifdef CONFIG_SLABINFO
5991 .name
= "kmem.slabinfo",
5992 .read_seq_string
= mem_cgroup_slabinfo_read
,
5996 { }, /* terminate */
5999 #ifdef CONFIG_MEMCG_SWAP
6000 static struct cftype memsw_cgroup_files
[] = {
6002 .name
= "memsw.usage_in_bytes",
6003 .private = MEMFILE_PRIVATE(_MEMSWAP
, RES_USAGE
),
6004 .read
= mem_cgroup_read
,
6005 .register_event
= mem_cgroup_usage_register_event
,
6006 .unregister_event
= mem_cgroup_usage_unregister_event
,
6009 .name
= "memsw.max_usage_in_bytes",
6010 .private = MEMFILE_PRIVATE(_MEMSWAP
, RES_MAX_USAGE
),
6011 .trigger
= mem_cgroup_reset
,
6012 .read
= mem_cgroup_read
,
6015 .name
= "memsw.limit_in_bytes",
6016 .private = MEMFILE_PRIVATE(_MEMSWAP
, RES_LIMIT
),
6017 .write_string
= mem_cgroup_write
,
6018 .read
= mem_cgroup_read
,
6021 .name
= "memsw.failcnt",
6022 .private = MEMFILE_PRIVATE(_MEMSWAP
, RES_FAILCNT
),
6023 .trigger
= mem_cgroup_reset
,
6024 .read
= mem_cgroup_read
,
6026 { }, /* terminate */
6029 static int alloc_mem_cgroup_per_zone_info(struct mem_cgroup
*memcg
, int node
)
6031 struct mem_cgroup_per_node
*pn
;
6032 struct mem_cgroup_per_zone
*mz
;
6033 int zone
, tmp
= node
;
6035 * This routine is called against possible nodes.
6036 * But it's BUG to call kmalloc() against offline node.
6038 * TODO: this routine can waste much memory for nodes which will
6039 * never be onlined. It's better to use memory hotplug callback
6042 if (!node_state(node
, N_NORMAL_MEMORY
))
6044 pn
= kzalloc_node(sizeof(*pn
), GFP_KERNEL
, tmp
);
6048 for (zone
= 0; zone
< MAX_NR_ZONES
; zone
++) {
6049 mz
= &pn
->zoneinfo
[zone
];
6050 lruvec_init(&mz
->lruvec
);
6051 mz
->usage_in_excess
= 0;
6052 mz
->on_tree
= false;
6055 memcg
->info
.nodeinfo
[node
] = pn
;
6059 static void free_mem_cgroup_per_zone_info(struct mem_cgroup
*memcg
, int node
)
6061 kfree(memcg
->info
.nodeinfo
[node
]);
6064 static struct mem_cgroup
*mem_cgroup_alloc(void)
6066 struct mem_cgroup
*memcg
;
6067 size_t size
= memcg_size();
6069 /* Can be very big if nr_node_ids is very big */
6070 if (size
< PAGE_SIZE
)
6071 memcg
= kzalloc(size
, GFP_KERNEL
);
6073 memcg
= vzalloc(size
);
6078 memcg
->stat
= alloc_percpu(struct mem_cgroup_stat_cpu
);
6081 spin_lock_init(&memcg
->pcp_counter_lock
);
6085 if (size
< PAGE_SIZE
)
6093 * At destroying mem_cgroup, references from swap_cgroup can remain.
6094 * (scanning all at force_empty is too costly...)
6096 * Instead of clearing all references at force_empty, we remember
6097 * the number of reference from swap_cgroup and free mem_cgroup when
6098 * it goes down to 0.
6100 * Removal of cgroup itself succeeds regardless of refs from swap.
6103 static void __mem_cgroup_free(struct mem_cgroup
*memcg
)
6106 size_t size
= memcg_size();
6108 mem_cgroup_remove_from_trees(memcg
);
6109 free_css_id(&mem_cgroup_subsys
, &memcg
->css
);
6112 free_mem_cgroup_per_zone_info(memcg
, node
);
6114 free_percpu(memcg
->stat
);
6117 * We need to make sure that (at least for now), the jump label
6118 * destruction code runs outside of the cgroup lock. This is because
6119 * get_online_cpus(), which is called from the static_branch update,
6120 * can't be called inside the cgroup_lock. cpusets are the ones
6121 * enforcing this dependency, so if they ever change, we might as well.
6123 * schedule_work() will guarantee this happens. Be careful if you need
6124 * to move this code around, and make sure it is outside
6127 disarm_static_keys(memcg
);
6128 if (size
< PAGE_SIZE
)
6136 * Helpers for freeing a kmalloc()ed/vzalloc()ed mem_cgroup by RCU,
6137 * but in process context. The work_freeing structure is overlaid
6138 * on the rcu_freeing structure, which itself is overlaid on memsw.
6140 static void free_work(struct work_struct
*work
)
6142 struct mem_cgroup
*memcg
;
6144 memcg
= container_of(work
, struct mem_cgroup
, work_freeing
);
6145 __mem_cgroup_free(memcg
);
6148 static void free_rcu(struct rcu_head
*rcu_head
)
6150 struct mem_cgroup
*memcg
;
6152 memcg
= container_of(rcu_head
, struct mem_cgroup
, rcu_freeing
);
6153 INIT_WORK(&memcg
->work_freeing
, free_work
);
6154 schedule_work(&memcg
->work_freeing
);
6157 static void mem_cgroup_get(struct mem_cgroup
*memcg
)
6159 atomic_inc(&memcg
->refcnt
);
6162 static void __mem_cgroup_put(struct mem_cgroup
*memcg
, int count
)
6164 if (atomic_sub_and_test(count
, &memcg
->refcnt
)) {
6165 struct mem_cgroup
*parent
= parent_mem_cgroup(memcg
);
6166 call_rcu(&memcg
->rcu_freeing
, free_rcu
);
6168 mem_cgroup_put(parent
);
6172 static void mem_cgroup_put(struct mem_cgroup
*memcg
)
6174 __mem_cgroup_put(memcg
, 1);
6178 * Returns the parent mem_cgroup in memcgroup hierarchy with hierarchy enabled.
6180 struct mem_cgroup
*parent_mem_cgroup(struct mem_cgroup
*memcg
)
6182 if (!memcg
->res
.parent
)
6184 return mem_cgroup_from_res_counter(memcg
->res
.parent
, res
);
6186 EXPORT_SYMBOL(parent_mem_cgroup
);
6188 static void __init
mem_cgroup_soft_limit_tree_init(void)
6190 struct mem_cgroup_tree_per_node
*rtpn
;
6191 struct mem_cgroup_tree_per_zone
*rtpz
;
6192 int tmp
, node
, zone
;
6194 for_each_node(node
) {
6196 if (!node_state(node
, N_NORMAL_MEMORY
))
6198 rtpn
= kzalloc_node(sizeof(*rtpn
), GFP_KERNEL
, tmp
);
6201 soft_limit_tree
.rb_tree_per_node
[node
] = rtpn
;
6203 for (zone
= 0; zone
< MAX_NR_ZONES
; zone
++) {
6204 rtpz
= &rtpn
->rb_tree_per_zone
[zone
];
6205 rtpz
->rb_root
= RB_ROOT
;
6206 spin_lock_init(&rtpz
->lock
);
6211 static struct cgroup_subsys_state
* __ref
6212 mem_cgroup_css_alloc(struct cgroup
*cont
)
6214 struct mem_cgroup
*memcg
;
6215 long error
= -ENOMEM
;
6218 memcg
= mem_cgroup_alloc();
6220 return ERR_PTR(error
);
6223 if (alloc_mem_cgroup_per_zone_info(memcg
, node
))
6227 if (cont
->parent
== NULL
) {
6228 root_mem_cgroup
= memcg
;
6229 res_counter_init(&memcg
->res
, NULL
);
6230 res_counter_init(&memcg
->memsw
, NULL
);
6231 res_counter_init(&memcg
->kmem
, NULL
);
6234 memcg
->last_scanned_node
= MAX_NUMNODES
;
6235 INIT_LIST_HEAD(&memcg
->oom_notify
);
6236 atomic_set(&memcg
->refcnt
, 1);
6237 memcg
->move_charge_at_immigrate
= 0;
6238 mutex_init(&memcg
->thresholds_lock
);
6239 spin_lock_init(&memcg
->move_lock
);
6240 vmpressure_init(&memcg
->vmpressure
);
6245 __mem_cgroup_free(memcg
);
6246 return ERR_PTR(error
);
6250 mem_cgroup_css_online(struct cgroup
*cont
)
6252 struct mem_cgroup
*memcg
, *parent
;
6258 mutex_lock(&memcg_create_mutex
);
6259 memcg
= mem_cgroup_from_cont(cont
);
6260 parent
= mem_cgroup_from_cont(cont
->parent
);
6262 memcg
->use_hierarchy
= parent
->use_hierarchy
;
6263 memcg
->oom_kill_disable
= parent
->oom_kill_disable
;
6264 memcg
->swappiness
= mem_cgroup_swappiness(parent
);
6266 if (parent
->use_hierarchy
) {
6267 res_counter_init(&memcg
->res
, &parent
->res
);
6268 res_counter_init(&memcg
->memsw
, &parent
->memsw
);
6269 res_counter_init(&memcg
->kmem
, &parent
->kmem
);
6272 * We increment refcnt of the parent to ensure that we can
6273 * safely access it on res_counter_charge/uncharge.
6274 * This refcnt will be decremented when freeing this
6275 * mem_cgroup(see mem_cgroup_put).
6277 mem_cgroup_get(parent
);
6279 res_counter_init(&memcg
->res
, NULL
);
6280 res_counter_init(&memcg
->memsw
, NULL
);
6281 res_counter_init(&memcg
->kmem
, NULL
);
6283 * Deeper hierachy with use_hierarchy == false doesn't make
6284 * much sense so let cgroup subsystem know about this
6285 * unfortunate state in our controller.
6287 if (parent
!= root_mem_cgroup
)
6288 mem_cgroup_subsys
.broken_hierarchy
= true;
6291 error
= memcg_init_kmem(memcg
, &mem_cgroup_subsys
);
6292 mutex_unlock(&memcg_create_mutex
);
6295 * We call put now because our (and parent's) refcnts
6296 * are already in place. mem_cgroup_put() will internally
6297 * call __mem_cgroup_free, so return directly
6299 mem_cgroup_put(memcg
);
6300 if (parent
->use_hierarchy
)
6301 mem_cgroup_put(parent
);
6307 * Announce all parents that a group from their hierarchy is gone.
6309 static void mem_cgroup_invalidate_reclaim_iterators(struct mem_cgroup
*memcg
)
6311 struct mem_cgroup
*parent
= memcg
;
6313 while ((parent
= parent_mem_cgroup(parent
)))
6314 atomic_inc(&parent
->dead_count
);
6317 * if the root memcg is not hierarchical we have to check it
6320 if (!root_mem_cgroup
->use_hierarchy
)
6321 atomic_inc(&root_mem_cgroup
->dead_count
);
6324 static void mem_cgroup_css_offline(struct cgroup
*cont
)
6326 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cont
);
6328 mem_cgroup_invalidate_reclaim_iterators(memcg
);
6329 mem_cgroup_reparent_charges(memcg
);
6330 mem_cgroup_destroy_all_caches(memcg
);
6333 static void mem_cgroup_css_free(struct cgroup
*cont
)
6335 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cont
);
6337 kmem_cgroup_destroy(memcg
);
6339 mem_cgroup_put(memcg
);
6343 /* Handlers for move charge at task migration. */
6344 #define PRECHARGE_COUNT_AT_ONCE 256
6345 static int mem_cgroup_do_precharge(unsigned long count
)
6348 int batch_count
= PRECHARGE_COUNT_AT_ONCE
;
6349 struct mem_cgroup
*memcg
= mc
.to
;
6351 if (mem_cgroup_is_root(memcg
)) {
6352 mc
.precharge
+= count
;
6353 /* we don't need css_get for root */
6356 /* try to charge at once */
6358 struct res_counter
*dummy
;
6360 * "memcg" cannot be under rmdir() because we've already checked
6361 * by cgroup_lock_live_cgroup() that it is not removed and we
6362 * are still under the same cgroup_mutex. So we can postpone
6365 if (res_counter_charge(&memcg
->res
, PAGE_SIZE
* count
, &dummy
))
6367 if (do_swap_account
&& res_counter_charge(&memcg
->memsw
,
6368 PAGE_SIZE
* count
, &dummy
)) {
6369 res_counter_uncharge(&memcg
->res
, PAGE_SIZE
* count
);
6372 mc
.precharge
+= count
;
6376 /* fall back to one by one charge */
6378 if (signal_pending(current
)) {
6382 if (!batch_count
--) {
6383 batch_count
= PRECHARGE_COUNT_AT_ONCE
;
6386 ret
= __mem_cgroup_try_charge(NULL
,
6387 GFP_KERNEL
, 1, &memcg
, false);
6389 /* mem_cgroup_clear_mc() will do uncharge later */
6397 * get_mctgt_type - get target type of moving charge
6398 * @vma: the vma the pte to be checked belongs
6399 * @addr: the address corresponding to the pte to be checked
6400 * @ptent: the pte to be checked
6401 * @target: the pointer the target page or swap ent will be stored(can be NULL)
6404 * 0(MC_TARGET_NONE): if the pte is not a target for move charge.
6405 * 1(MC_TARGET_PAGE): if the page corresponding to this pte is a target for
6406 * move charge. if @target is not NULL, the page is stored in target->page
6407 * with extra refcnt got(Callers should handle it).
6408 * 2(MC_TARGET_SWAP): if the swap entry corresponding to this pte is a
6409 * target for charge migration. if @target is not NULL, the entry is stored
6412 * Called with pte lock held.
6419 enum mc_target_type
{
6425 static struct page
*mc_handle_present_pte(struct vm_area_struct
*vma
,
6426 unsigned long addr
, pte_t ptent
)
6428 struct page
*page
= vm_normal_page(vma
, addr
, ptent
);
6430 if (!page
|| !page_mapped(page
))
6432 if (PageAnon(page
)) {
6433 /* we don't move shared anon */
6436 } else if (!move_file())
6437 /* we ignore mapcount for file pages */
6439 if (!get_page_unless_zero(page
))
6446 static struct page
*mc_handle_swap_pte(struct vm_area_struct
*vma
,
6447 unsigned long addr
, pte_t ptent
, swp_entry_t
*entry
)
6449 struct page
*page
= NULL
;
6450 swp_entry_t ent
= pte_to_swp_entry(ptent
);
6452 if (!move_anon() || non_swap_entry(ent
))
6455 * Because lookup_swap_cache() updates some statistics counter,
6456 * we call find_get_page() with swapper_space directly.
6458 page
= find_get_page(swap_address_space(ent
), ent
.val
);
6459 if (do_swap_account
)
6460 entry
->val
= ent
.val
;
6465 static struct page
*mc_handle_swap_pte(struct vm_area_struct
*vma
,
6466 unsigned long addr
, pte_t ptent
, swp_entry_t
*entry
)
6472 static struct page
*mc_handle_file_pte(struct vm_area_struct
*vma
,
6473 unsigned long addr
, pte_t ptent
, swp_entry_t
*entry
)
6475 struct page
*page
= NULL
;
6476 struct address_space
*mapping
;
6479 if (!vma
->vm_file
) /* anonymous vma */
6484 mapping
= vma
->vm_file
->f_mapping
;
6485 if (pte_none(ptent
))
6486 pgoff
= linear_page_index(vma
, addr
);
6487 else /* pte_file(ptent) is true */
6488 pgoff
= pte_to_pgoff(ptent
);
6490 /* page is moved even if it's not RSS of this task(page-faulted). */
6491 page
= find_get_page(mapping
, pgoff
);
6494 /* shmem/tmpfs may report page out on swap: account for that too. */
6495 if (radix_tree_exceptional_entry(page
)) {
6496 swp_entry_t swap
= radix_to_swp_entry(page
);
6497 if (do_swap_account
)
6499 page
= find_get_page(swap_address_space(swap
), swap
.val
);
6505 static enum mc_target_type
get_mctgt_type(struct vm_area_struct
*vma
,
6506 unsigned long addr
, pte_t ptent
, union mc_target
*target
)
6508 struct page
*page
= NULL
;
6509 struct page_cgroup
*pc
;
6510 enum mc_target_type ret
= MC_TARGET_NONE
;
6511 swp_entry_t ent
= { .val
= 0 };
6513 if (pte_present(ptent
))
6514 page
= mc_handle_present_pte(vma
, addr
, ptent
);
6515 else if (is_swap_pte(ptent
))
6516 page
= mc_handle_swap_pte(vma
, addr
, ptent
, &ent
);
6517 else if (pte_none(ptent
) || pte_file(ptent
))
6518 page
= mc_handle_file_pte(vma
, addr
, ptent
, &ent
);
6520 if (!page
&& !ent
.val
)
6523 pc
= lookup_page_cgroup(page
);
6525 * Do only loose check w/o page_cgroup lock.
6526 * mem_cgroup_move_account() checks the pc is valid or not under
6529 if (PageCgroupUsed(pc
) && pc
->mem_cgroup
== mc
.from
) {
6530 ret
= MC_TARGET_PAGE
;
6532 target
->page
= page
;
6534 if (!ret
|| !target
)
6537 /* There is a swap entry and a page doesn't exist or isn't charged */
6538 if (ent
.val
&& !ret
&&
6539 css_id(&mc
.from
->css
) == lookup_swap_cgroup_id(ent
)) {
6540 ret
= MC_TARGET_SWAP
;
6547 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
6549 * We don't consider swapping or file mapped pages because THP does not
6550 * support them for now.
6551 * Caller should make sure that pmd_trans_huge(pmd) is true.
6553 static enum mc_target_type
get_mctgt_type_thp(struct vm_area_struct
*vma
,
6554 unsigned long addr
, pmd_t pmd
, union mc_target
*target
)
6556 struct page
*page
= NULL
;
6557 struct page_cgroup
*pc
;
6558 enum mc_target_type ret
= MC_TARGET_NONE
;
6560 page
= pmd_page(pmd
);
6561 VM_BUG_ON(!page
|| !PageHead(page
));
6564 pc
= lookup_page_cgroup(page
);
6565 if (PageCgroupUsed(pc
) && pc
->mem_cgroup
== mc
.from
) {
6566 ret
= MC_TARGET_PAGE
;
6569 target
->page
= page
;
6575 static inline enum mc_target_type
get_mctgt_type_thp(struct vm_area_struct
*vma
,
6576 unsigned long addr
, pmd_t pmd
, union mc_target
*target
)
6578 return MC_TARGET_NONE
;
6582 static int mem_cgroup_count_precharge_pte_range(pmd_t
*pmd
,
6583 unsigned long addr
, unsigned long end
,
6584 struct mm_walk
*walk
)
6586 struct vm_area_struct
*vma
= walk
->private;
6590 if (pmd_trans_huge_lock(pmd
, vma
) == 1) {
6591 if (get_mctgt_type_thp(vma
, addr
, *pmd
, NULL
) == MC_TARGET_PAGE
)
6592 mc
.precharge
+= HPAGE_PMD_NR
;
6593 spin_unlock(&vma
->vm_mm
->page_table_lock
);
6597 if (pmd_trans_unstable(pmd
))
6599 pte
= pte_offset_map_lock(vma
->vm_mm
, pmd
, addr
, &ptl
);
6600 for (; addr
!= end
; pte
++, addr
+= PAGE_SIZE
)
6601 if (get_mctgt_type(vma
, addr
, *pte
, NULL
))
6602 mc
.precharge
++; /* increment precharge temporarily */
6603 pte_unmap_unlock(pte
- 1, ptl
);
6609 static unsigned long mem_cgroup_count_precharge(struct mm_struct
*mm
)
6611 unsigned long precharge
;
6612 struct vm_area_struct
*vma
;
6614 down_read(&mm
->mmap_sem
);
6615 for (vma
= mm
->mmap
; vma
; vma
= vma
->vm_next
) {
6616 struct mm_walk mem_cgroup_count_precharge_walk
= {
6617 .pmd_entry
= mem_cgroup_count_precharge_pte_range
,
6621 if (is_vm_hugetlb_page(vma
))
6623 walk_page_range(vma
->vm_start
, vma
->vm_end
,
6624 &mem_cgroup_count_precharge_walk
);
6626 up_read(&mm
->mmap_sem
);
6628 precharge
= mc
.precharge
;
6634 static int mem_cgroup_precharge_mc(struct mm_struct
*mm
)
6636 unsigned long precharge
= mem_cgroup_count_precharge(mm
);
6638 VM_BUG_ON(mc
.moving_task
);
6639 mc
.moving_task
= current
;
6640 return mem_cgroup_do_precharge(precharge
);
6643 /* cancels all extra charges on mc.from and mc.to, and wakes up all waiters. */
6644 static void __mem_cgroup_clear_mc(void)
6646 struct mem_cgroup
*from
= mc
.from
;
6647 struct mem_cgroup
*to
= mc
.to
;
6649 /* we must uncharge all the leftover precharges from mc.to */
6651 __mem_cgroup_cancel_charge(mc
.to
, mc
.precharge
);
6655 * we didn't uncharge from mc.from at mem_cgroup_move_account(), so
6656 * we must uncharge here.
6658 if (mc
.moved_charge
) {
6659 __mem_cgroup_cancel_charge(mc
.from
, mc
.moved_charge
);
6660 mc
.moved_charge
= 0;
6662 /* we must fixup refcnts and charges */
6663 if (mc
.moved_swap
) {
6664 /* uncharge swap account from the old cgroup */
6665 if (!mem_cgroup_is_root(mc
.from
))
6666 res_counter_uncharge(&mc
.from
->memsw
,
6667 PAGE_SIZE
* mc
.moved_swap
);
6668 __mem_cgroup_put(mc
.from
, mc
.moved_swap
);
6670 if (!mem_cgroup_is_root(mc
.to
)) {
6672 * we charged both to->res and to->memsw, so we should
6675 res_counter_uncharge(&mc
.to
->res
,
6676 PAGE_SIZE
* mc
.moved_swap
);
6678 /* we've already done mem_cgroup_get(mc.to) */
6681 memcg_oom_recover(from
);
6682 memcg_oom_recover(to
);
6683 wake_up_all(&mc
.waitq
);
6686 static void mem_cgroup_clear_mc(void)
6688 struct mem_cgroup
*from
= mc
.from
;
6691 * we must clear moving_task before waking up waiters at the end of
6694 mc
.moving_task
= NULL
;
6695 __mem_cgroup_clear_mc();
6696 spin_lock(&mc
.lock
);
6699 spin_unlock(&mc
.lock
);
6700 mem_cgroup_end_move(from
);
6703 static int mem_cgroup_can_attach(struct cgroup
*cgroup
,
6704 struct cgroup_taskset
*tset
)
6706 struct task_struct
*p
= cgroup_taskset_first(tset
);
6708 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cgroup
);
6709 unsigned long move_charge_at_immigrate
;
6712 * We are now commited to this value whatever it is. Changes in this
6713 * tunable will only affect upcoming migrations, not the current one.
6714 * So we need to save it, and keep it going.
6716 move_charge_at_immigrate
= memcg
->move_charge_at_immigrate
;
6717 if (move_charge_at_immigrate
) {
6718 struct mm_struct
*mm
;
6719 struct mem_cgroup
*from
= mem_cgroup_from_task(p
);
6721 VM_BUG_ON(from
== memcg
);
6723 mm
= get_task_mm(p
);
6726 /* We move charges only when we move a owner of the mm */
6727 if (mm
->owner
== p
) {
6730 VM_BUG_ON(mc
.precharge
);
6731 VM_BUG_ON(mc
.moved_charge
);
6732 VM_BUG_ON(mc
.moved_swap
);
6733 mem_cgroup_start_move(from
);
6734 spin_lock(&mc
.lock
);
6737 mc
.immigrate_flags
= move_charge_at_immigrate
;
6738 spin_unlock(&mc
.lock
);
6739 /* We set mc.moving_task later */
6741 ret
= mem_cgroup_precharge_mc(mm
);
6743 mem_cgroup_clear_mc();
6750 static void mem_cgroup_cancel_attach(struct cgroup
*cgroup
,
6751 struct cgroup_taskset
*tset
)
6753 mem_cgroup_clear_mc();
6756 static int mem_cgroup_move_charge_pte_range(pmd_t
*pmd
,
6757 unsigned long addr
, unsigned long end
,
6758 struct mm_walk
*walk
)
6761 struct vm_area_struct
*vma
= walk
->private;
6764 enum mc_target_type target_type
;
6765 union mc_target target
;
6767 struct page_cgroup
*pc
;
6770 * We don't take compound_lock() here but no race with splitting thp
6772 * - if pmd_trans_huge_lock() returns 1, the relevant thp is not
6773 * under splitting, which means there's no concurrent thp split,
6774 * - if another thread runs into split_huge_page() just after we
6775 * entered this if-block, the thread must wait for page table lock
6776 * to be unlocked in __split_huge_page_splitting(), where the main
6777 * part of thp split is not executed yet.
6779 if (pmd_trans_huge_lock(pmd
, vma
) == 1) {
6780 if (mc
.precharge
< HPAGE_PMD_NR
) {
6781 spin_unlock(&vma
->vm_mm
->page_table_lock
);
6784 target_type
= get_mctgt_type_thp(vma
, addr
, *pmd
, &target
);
6785 if (target_type
== MC_TARGET_PAGE
) {
6787 if (!isolate_lru_page(page
)) {
6788 pc
= lookup_page_cgroup(page
);
6789 if (!mem_cgroup_move_account(page
, HPAGE_PMD_NR
,
6790 pc
, mc
.from
, mc
.to
)) {
6791 mc
.precharge
-= HPAGE_PMD_NR
;
6792 mc
.moved_charge
+= HPAGE_PMD_NR
;
6794 putback_lru_page(page
);
6798 spin_unlock(&vma
->vm_mm
->page_table_lock
);
6802 if (pmd_trans_unstable(pmd
))
6805 pte
= pte_offset_map_lock(vma
->vm_mm
, pmd
, addr
, &ptl
);
6806 for (; addr
!= end
; addr
+= PAGE_SIZE
) {
6807 pte_t ptent
= *(pte
++);
6813 switch (get_mctgt_type(vma
, addr
, ptent
, &target
)) {
6814 case MC_TARGET_PAGE
:
6816 if (isolate_lru_page(page
))
6818 pc
= lookup_page_cgroup(page
);
6819 if (!mem_cgroup_move_account(page
, 1, pc
,
6822 /* we uncharge from mc.from later. */
6825 putback_lru_page(page
);
6826 put
: /* get_mctgt_type() gets the page */
6829 case MC_TARGET_SWAP
:
6831 if (!mem_cgroup_move_swap_account(ent
, mc
.from
, mc
.to
)) {
6833 /* we fixup refcnts and charges later. */
6841 pte_unmap_unlock(pte
- 1, ptl
);
6846 * We have consumed all precharges we got in can_attach().
6847 * We try charge one by one, but don't do any additional
6848 * charges to mc.to if we have failed in charge once in attach()
6851 ret
= mem_cgroup_do_precharge(1);
6859 static void mem_cgroup_move_charge(struct mm_struct
*mm
)
6861 struct vm_area_struct
*vma
;
6863 lru_add_drain_all();
6865 if (unlikely(!down_read_trylock(&mm
->mmap_sem
))) {
6867 * Someone who are holding the mmap_sem might be waiting in
6868 * waitq. So we cancel all extra charges, wake up all waiters,
6869 * and retry. Because we cancel precharges, we might not be able
6870 * to move enough charges, but moving charge is a best-effort
6871 * feature anyway, so it wouldn't be a big problem.
6873 __mem_cgroup_clear_mc();
6877 for (vma
= mm
->mmap
; vma
; vma
= vma
->vm_next
) {
6879 struct mm_walk mem_cgroup_move_charge_walk
= {
6880 .pmd_entry
= mem_cgroup_move_charge_pte_range
,
6884 if (is_vm_hugetlb_page(vma
))
6886 ret
= walk_page_range(vma
->vm_start
, vma
->vm_end
,
6887 &mem_cgroup_move_charge_walk
);
6890 * means we have consumed all precharges and failed in
6891 * doing additional charge. Just abandon here.
6895 up_read(&mm
->mmap_sem
);
6898 static void mem_cgroup_move_task(struct cgroup
*cont
,
6899 struct cgroup_taskset
*tset
)
6901 struct task_struct
*p
= cgroup_taskset_first(tset
);
6902 struct mm_struct
*mm
= get_task_mm(p
);
6906 mem_cgroup_move_charge(mm
);
6910 mem_cgroup_clear_mc();
6912 #else /* !CONFIG_MMU */
6913 static int mem_cgroup_can_attach(struct cgroup
*cgroup
,
6914 struct cgroup_taskset
*tset
)
6918 static void mem_cgroup_cancel_attach(struct cgroup
*cgroup
,
6919 struct cgroup_taskset
*tset
)
6922 static void mem_cgroup_move_task(struct cgroup
*cont
,
6923 struct cgroup_taskset
*tset
)
6929 * Cgroup retains root cgroups across [un]mount cycles making it necessary
6930 * to verify sane_behavior flag on each mount attempt.
6932 static void mem_cgroup_bind(struct cgroup
*root
)
6935 * use_hierarchy is forced with sane_behavior. cgroup core
6936 * guarantees that @root doesn't have any children, so turning it
6937 * on for the root memcg is enough.
6939 if (cgroup_sane_behavior(root
))
6940 mem_cgroup_from_cont(root
)->use_hierarchy
= true;
6943 struct cgroup_subsys mem_cgroup_subsys
= {
6945 .subsys_id
= mem_cgroup_subsys_id
,
6946 .css_alloc
= mem_cgroup_css_alloc
,
6947 .css_online
= mem_cgroup_css_online
,
6948 .css_offline
= mem_cgroup_css_offline
,
6949 .css_free
= mem_cgroup_css_free
,
6950 .can_attach
= mem_cgroup_can_attach
,
6951 .cancel_attach
= mem_cgroup_cancel_attach
,
6952 .attach
= mem_cgroup_move_task
,
6953 .bind
= mem_cgroup_bind
,
6954 .base_cftypes
= mem_cgroup_files
,
6959 #ifdef CONFIG_MEMCG_SWAP
6960 static int __init
enable_swap_account(char *s
)
6962 /* consider enabled if no parameter or 1 is given */
6963 if (!strcmp(s
, "1"))
6964 really_do_swap_account
= 1;
6965 else if (!strcmp(s
, "0"))
6966 really_do_swap_account
= 0;
6969 __setup("swapaccount=", enable_swap_account
);
6971 static void __init
memsw_file_init(void)
6973 WARN_ON(cgroup_add_cftypes(&mem_cgroup_subsys
, memsw_cgroup_files
));
6976 static void __init
enable_swap_cgroup(void)
6978 if (!mem_cgroup_disabled() && really_do_swap_account
) {
6979 do_swap_account
= 1;
6985 static void __init
enable_swap_cgroup(void)
6991 * subsys_initcall() for memory controller.
6993 * Some parts like hotcpu_notifier() have to be initialized from this context
6994 * because of lock dependencies (cgroup_lock -> cpu hotplug) but basically
6995 * everything that doesn't depend on a specific mem_cgroup structure should
6996 * be initialized from here.
6998 static int __init
mem_cgroup_init(void)
7000 hotcpu_notifier(memcg_cpu_hotplug_callback
, 0);
7001 enable_swap_cgroup();
7002 mem_cgroup_soft_limit_tree_init();
7006 subsys_initcall(mem_cgroup_init
);