1 /* memcontrol.c - Memory Controller
3 * Copyright IBM Corporation, 2007
4 * Author Balbir Singh <balbir@linux.vnet.ibm.com>
6 * Copyright 2007 OpenVZ SWsoft Inc
7 * Author: Pavel Emelianov <xemul@openvz.org>
10 * Copyright (C) 2009 Nokia Corporation
11 * Author: Kirill A. Shutemov
13 * Kernel Memory Controller
14 * Copyright (C) 2012 Parallels Inc. and Google Inc.
15 * Authors: Glauber Costa and Suleiman Souhlal
17 * This program is free software; you can redistribute it and/or modify
18 * it under the terms of the GNU General Public License as published by
19 * the Free Software Foundation; either version 2 of the License, or
20 * (at your option) any later version.
22 * This program is distributed in the hope that it will be useful,
23 * but WITHOUT ANY WARRANTY; without even the implied warranty of
24 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
25 * GNU General Public License for more details.
28 #include <linux/res_counter.h>
29 #include <linux/memcontrol.h>
30 #include <linux/cgroup.h>
32 #include <linux/hugetlb.h>
33 #include <linux/pagemap.h>
34 #include <linux/smp.h>
35 #include <linux/page-flags.h>
36 #include <linux/backing-dev.h>
37 #include <linux/bit_spinlock.h>
38 #include <linux/rcupdate.h>
39 #include <linux/limits.h>
40 #include <linux/export.h>
41 #include <linux/mutex.h>
42 #include <linux/rbtree.h>
43 #include <linux/slab.h>
44 #include <linux/swap.h>
45 #include <linux/swapops.h>
46 #include <linux/spinlock.h>
47 #include <linux/eventfd.h>
48 #include <linux/sort.h>
50 #include <linux/seq_file.h>
51 #include <linux/vmalloc.h>
52 #include <linux/vmpressure.h>
53 #include <linux/mm_inline.h>
54 #include <linux/page_cgroup.h>
55 #include <linux/cpu.h>
56 #include <linux/oom.h>
60 #include <net/tcp_memcontrol.h>
62 #include <asm/uaccess.h>
64 #include <trace/events/vmscan.h>
66 struct cgroup_subsys mem_cgroup_subsys __read_mostly
;
67 EXPORT_SYMBOL(mem_cgroup_subsys
);
69 #define MEM_CGROUP_RECLAIM_RETRIES 5
70 static struct mem_cgroup
*root_mem_cgroup __read_mostly
;
72 #ifdef CONFIG_MEMCG_SWAP
73 /* Turned on only when memory cgroup is enabled && really_do_swap_account = 1 */
74 int do_swap_account __read_mostly
;
76 /* for remember boot option*/
77 #ifdef CONFIG_MEMCG_SWAP_ENABLED
78 static int really_do_swap_account __initdata
= 1;
80 static int really_do_swap_account __initdata
= 0;
84 #define do_swap_account 0
89 * Statistics for memory cgroup.
91 enum mem_cgroup_stat_index
{
93 * For MEM_CONTAINER_TYPE_ALL, usage = pagecache + rss.
95 MEM_CGROUP_STAT_CACHE
, /* # of pages charged as cache */
96 MEM_CGROUP_STAT_RSS
, /* # of pages charged as anon rss */
97 MEM_CGROUP_STAT_RSS_HUGE
, /* # of pages charged as anon huge */
98 MEM_CGROUP_STAT_FILE_MAPPED
, /* # of pages charged as file rss */
99 MEM_CGROUP_STAT_SWAP
, /* # of pages, swapped out */
100 MEM_CGROUP_STAT_NSTATS
,
103 static const char * const mem_cgroup_stat_names
[] = {
111 enum mem_cgroup_events_index
{
112 MEM_CGROUP_EVENTS_PGPGIN
, /* # of pages paged in */
113 MEM_CGROUP_EVENTS_PGPGOUT
, /* # of pages paged out */
114 MEM_CGROUP_EVENTS_PGFAULT
, /* # of page-faults */
115 MEM_CGROUP_EVENTS_PGMAJFAULT
, /* # of major page-faults */
116 MEM_CGROUP_EVENTS_NSTATS
,
119 static const char * const mem_cgroup_events_names
[] = {
126 static const char * const mem_cgroup_lru_names
[] = {
135 * Per memcg event counter is incremented at every pagein/pageout. With THP,
136 * it will be incremated by the number of pages. This counter is used for
137 * for trigger some periodic events. This is straightforward and better
138 * than using jiffies etc. to handle periodic memcg event.
140 enum mem_cgroup_events_target
{
141 MEM_CGROUP_TARGET_THRESH
,
142 MEM_CGROUP_TARGET_SOFTLIMIT
,
143 MEM_CGROUP_TARGET_NUMAINFO
,
146 #define THRESHOLDS_EVENTS_TARGET 128
147 #define SOFTLIMIT_EVENTS_TARGET 1024
148 #define NUMAINFO_EVENTS_TARGET 1024
150 struct mem_cgroup_stat_cpu
{
151 long count
[MEM_CGROUP_STAT_NSTATS
];
152 unsigned long events
[MEM_CGROUP_EVENTS_NSTATS
];
153 unsigned long nr_page_events
;
154 unsigned long targets
[MEM_CGROUP_NTARGETS
];
157 struct mem_cgroup_reclaim_iter
{
159 * last scanned hierarchy member. Valid only if last_dead_count
160 * matches memcg->dead_count of the hierarchy root group.
162 struct mem_cgroup
*last_visited
;
163 unsigned long last_dead_count
;
165 /* scan generation, increased every round-trip */
166 unsigned int generation
;
170 * per-zone information in memory controller.
172 struct mem_cgroup_per_zone
{
173 struct lruvec lruvec
;
174 unsigned long lru_size
[NR_LRU_LISTS
];
176 struct mem_cgroup_reclaim_iter reclaim_iter
[DEF_PRIORITY
+ 1];
178 struct rb_node tree_node
; /* RB tree node */
179 unsigned long long usage_in_excess
;/* Set to the value by which */
180 /* the soft limit is exceeded*/
182 struct mem_cgroup
*memcg
; /* Back pointer, we cannot */
183 /* use container_of */
186 struct mem_cgroup_per_node
{
187 struct mem_cgroup_per_zone zoneinfo
[MAX_NR_ZONES
];
191 * Cgroups above their limits are maintained in a RB-Tree, independent of
192 * their hierarchy representation
195 struct mem_cgroup_tree_per_zone
{
196 struct rb_root rb_root
;
200 struct mem_cgroup_tree_per_node
{
201 struct mem_cgroup_tree_per_zone rb_tree_per_zone
[MAX_NR_ZONES
];
204 struct mem_cgroup_tree
{
205 struct mem_cgroup_tree_per_node
*rb_tree_per_node
[MAX_NUMNODES
];
208 static struct mem_cgroup_tree soft_limit_tree __read_mostly
;
210 struct mem_cgroup_threshold
{
211 struct eventfd_ctx
*eventfd
;
216 struct mem_cgroup_threshold_ary
{
217 /* An array index points to threshold just below or equal to usage. */
218 int current_threshold
;
219 /* Size of entries[] */
221 /* Array of thresholds */
222 struct mem_cgroup_threshold entries
[0];
225 struct mem_cgroup_thresholds
{
226 /* Primary thresholds array */
227 struct mem_cgroup_threshold_ary
*primary
;
229 * Spare threshold array.
230 * This is needed to make mem_cgroup_unregister_event() "never fail".
231 * It must be able to store at least primary->size - 1 entries.
233 struct mem_cgroup_threshold_ary
*spare
;
237 struct mem_cgroup_eventfd_list
{
238 struct list_head list
;
239 struct eventfd_ctx
*eventfd
;
242 static void mem_cgroup_threshold(struct mem_cgroup
*memcg
);
243 static void mem_cgroup_oom_notify(struct mem_cgroup
*memcg
);
246 * The memory controller data structure. The memory controller controls both
247 * page cache and RSS per cgroup. We would eventually like to provide
248 * statistics based on the statistics developed by Rik Van Riel for clock-pro,
249 * to help the administrator determine what knobs to tune.
251 * TODO: Add a water mark for the memory controller. Reclaim will begin when
252 * we hit the water mark. May be even add a low water mark, such that
253 * no reclaim occurs from a cgroup at it's low water mark, this is
254 * a feature that will be implemented much later in the future.
257 struct cgroup_subsys_state css
;
259 * the counter to account for memory usage
261 struct res_counter res
;
263 /* vmpressure notifications */
264 struct vmpressure vmpressure
;
267 * the counter to account for mem+swap usage.
269 struct res_counter memsw
;
272 * the counter to account for kernel memory usage.
274 struct res_counter kmem
;
276 * Should the accounting and control be hierarchical, per subtree?
279 unsigned long kmem_account_flags
; /* See KMEM_ACCOUNTED_*, below */
285 /* OOM-Killer disable */
286 int oom_kill_disable
;
288 /* set when res.limit == memsw.limit */
289 bool memsw_is_minimum
;
291 /* protect arrays of thresholds */
292 struct mutex thresholds_lock
;
294 /* thresholds for memory usage. RCU-protected */
295 struct mem_cgroup_thresholds thresholds
;
297 /* thresholds for mem+swap usage. RCU-protected */
298 struct mem_cgroup_thresholds memsw_thresholds
;
300 /* For oom notifier event fd */
301 struct list_head oom_notify
;
304 * Should we move charges of a task when a task is moved into this
305 * mem_cgroup ? And what type of charges should we move ?
307 unsigned long move_charge_at_immigrate
;
309 * set > 0 if pages under this cgroup are moving to other cgroup.
311 atomic_t moving_account
;
312 /* taken only while moving_account > 0 */
313 spinlock_t move_lock
;
317 struct mem_cgroup_stat_cpu __percpu
*stat
;
319 * used when a cpu is offlined or other synchronizations
320 * See mem_cgroup_read_stat().
322 struct mem_cgroup_stat_cpu nocpu_base
;
323 spinlock_t pcp_counter_lock
;
326 #if defined(CONFIG_MEMCG_KMEM) && defined(CONFIG_INET)
327 struct tcp_memcontrol tcp_mem
;
329 #if defined(CONFIG_MEMCG_KMEM)
330 /* analogous to slab_common's slab_caches list. per-memcg */
331 struct list_head memcg_slab_caches
;
332 /* Not a spinlock, we can take a lot of time walking the list */
333 struct mutex slab_caches_mutex
;
334 /* Index in the kmem_cache->memcg_params->memcg_caches array */
338 int last_scanned_node
;
340 nodemask_t scan_nodes
;
341 atomic_t numainfo_events
;
342 atomic_t numainfo_updating
;
345 struct mem_cgroup_per_node
*nodeinfo
[0];
346 /* WARNING: nodeinfo must be the last member here */
349 static size_t memcg_size(void)
351 return sizeof(struct mem_cgroup
) +
352 nr_node_ids
* sizeof(struct mem_cgroup_per_node
);
355 /* internal only representation about the status of kmem accounting. */
357 KMEM_ACCOUNTED_ACTIVE
= 0, /* accounted by this cgroup itself */
358 KMEM_ACCOUNTED_ACTIVATED
, /* static key enabled. */
359 KMEM_ACCOUNTED_DEAD
, /* dead memcg with pending kmem charges */
362 /* We account when limit is on, but only after call sites are patched */
363 #define KMEM_ACCOUNTED_MASK \
364 ((1 << KMEM_ACCOUNTED_ACTIVE) | (1 << KMEM_ACCOUNTED_ACTIVATED))
366 #ifdef CONFIG_MEMCG_KMEM
367 static inline void memcg_kmem_set_active(struct mem_cgroup
*memcg
)
369 set_bit(KMEM_ACCOUNTED_ACTIVE
, &memcg
->kmem_account_flags
);
372 static bool memcg_kmem_is_active(struct mem_cgroup
*memcg
)
374 return test_bit(KMEM_ACCOUNTED_ACTIVE
, &memcg
->kmem_account_flags
);
377 static void memcg_kmem_set_activated(struct mem_cgroup
*memcg
)
379 set_bit(KMEM_ACCOUNTED_ACTIVATED
, &memcg
->kmem_account_flags
);
382 static void memcg_kmem_clear_activated(struct mem_cgroup
*memcg
)
384 clear_bit(KMEM_ACCOUNTED_ACTIVATED
, &memcg
->kmem_account_flags
);
387 static void memcg_kmem_mark_dead(struct mem_cgroup
*memcg
)
390 * Our caller must use css_get() first, because memcg_uncharge_kmem()
391 * will call css_put() if it sees the memcg is dead.
394 if (test_bit(KMEM_ACCOUNTED_ACTIVE
, &memcg
->kmem_account_flags
))
395 set_bit(KMEM_ACCOUNTED_DEAD
, &memcg
->kmem_account_flags
);
398 static bool memcg_kmem_test_and_clear_dead(struct mem_cgroup
*memcg
)
400 return test_and_clear_bit(KMEM_ACCOUNTED_DEAD
,
401 &memcg
->kmem_account_flags
);
405 /* Stuffs for move charges at task migration. */
407 * Types of charges to be moved. "move_charge_at_immitgrate" and
408 * "immigrate_flags" are treated as a left-shifted bitmap of these types.
411 MOVE_CHARGE_TYPE_ANON
, /* private anonymous page and swap of it */
412 MOVE_CHARGE_TYPE_FILE
, /* file page(including tmpfs) and swap of it */
416 /* "mc" and its members are protected by cgroup_mutex */
417 static struct move_charge_struct
{
418 spinlock_t lock
; /* for from, to */
419 struct mem_cgroup
*from
;
420 struct mem_cgroup
*to
;
421 unsigned long immigrate_flags
;
422 unsigned long precharge
;
423 unsigned long moved_charge
;
424 unsigned long moved_swap
;
425 struct task_struct
*moving_task
; /* a task moving charges */
426 wait_queue_head_t waitq
; /* a waitq for other context */
428 .lock
= __SPIN_LOCK_UNLOCKED(mc
.lock
),
429 .waitq
= __WAIT_QUEUE_HEAD_INITIALIZER(mc
.waitq
),
432 static bool move_anon(void)
434 return test_bit(MOVE_CHARGE_TYPE_ANON
, &mc
.immigrate_flags
);
437 static bool move_file(void)
439 return test_bit(MOVE_CHARGE_TYPE_FILE
, &mc
.immigrate_flags
);
443 * Maximum loops in mem_cgroup_hierarchical_reclaim(), used for soft
444 * limit reclaim to prevent infinite loops, if they ever occur.
446 #define MEM_CGROUP_MAX_RECLAIM_LOOPS 100
447 #define MEM_CGROUP_MAX_SOFT_LIMIT_RECLAIM_LOOPS 2
450 MEM_CGROUP_CHARGE_TYPE_CACHE
= 0,
451 MEM_CGROUP_CHARGE_TYPE_ANON
,
452 MEM_CGROUP_CHARGE_TYPE_SWAPOUT
, /* for accounting swapcache */
453 MEM_CGROUP_CHARGE_TYPE_DROP
, /* a page was unused swap cache */
457 /* for encoding cft->private value on file */
465 #define MEMFILE_PRIVATE(x, val) ((x) << 16 | (val))
466 #define MEMFILE_TYPE(val) ((val) >> 16 & 0xffff)
467 #define MEMFILE_ATTR(val) ((val) & 0xffff)
468 /* Used for OOM nofiier */
469 #define OOM_CONTROL (0)
472 * Reclaim flags for mem_cgroup_hierarchical_reclaim
474 #define MEM_CGROUP_RECLAIM_NOSWAP_BIT 0x0
475 #define MEM_CGROUP_RECLAIM_NOSWAP (1 << MEM_CGROUP_RECLAIM_NOSWAP_BIT)
476 #define MEM_CGROUP_RECLAIM_SHRINK_BIT 0x1
477 #define MEM_CGROUP_RECLAIM_SHRINK (1 << MEM_CGROUP_RECLAIM_SHRINK_BIT)
480 * The memcg_create_mutex will be held whenever a new cgroup is created.
481 * As a consequence, any change that needs to protect against new child cgroups
482 * appearing has to hold it as well.
484 static DEFINE_MUTEX(memcg_create_mutex
);
487 struct mem_cgroup
*mem_cgroup_from_css(struct cgroup_subsys_state
*s
)
489 return s
? container_of(s
, struct mem_cgroup
, css
) : NULL
;
492 /* Some nice accessors for the vmpressure. */
493 struct vmpressure
*memcg_to_vmpressure(struct mem_cgroup
*memcg
)
496 memcg
= root_mem_cgroup
;
497 return &memcg
->vmpressure
;
500 struct cgroup_subsys_state
*vmpressure_to_css(struct vmpressure
*vmpr
)
502 return &container_of(vmpr
, struct mem_cgroup
, vmpressure
)->css
;
505 struct vmpressure
*css_to_vmpressure(struct cgroup_subsys_state
*css
)
507 return &mem_cgroup_from_css(css
)->vmpressure
;
510 static inline bool mem_cgroup_is_root(struct mem_cgroup
*memcg
)
512 return (memcg
== root_mem_cgroup
);
515 /* Writing them here to avoid exposing memcg's inner layout */
516 #if defined(CONFIG_INET) && defined(CONFIG_MEMCG_KMEM)
518 void sock_update_memcg(struct sock
*sk
)
520 if (mem_cgroup_sockets_enabled
) {
521 struct mem_cgroup
*memcg
;
522 struct cg_proto
*cg_proto
;
524 BUG_ON(!sk
->sk_prot
->proto_cgroup
);
526 /* Socket cloning can throw us here with sk_cgrp already
527 * filled. It won't however, necessarily happen from
528 * process context. So the test for root memcg given
529 * the current task's memcg won't help us in this case.
531 * Respecting the original socket's memcg is a better
532 * decision in this case.
535 BUG_ON(mem_cgroup_is_root(sk
->sk_cgrp
->memcg
));
536 css_get(&sk
->sk_cgrp
->memcg
->css
);
541 memcg
= mem_cgroup_from_task(current
);
542 cg_proto
= sk
->sk_prot
->proto_cgroup(memcg
);
543 if (!mem_cgroup_is_root(memcg
) &&
544 memcg_proto_active(cg_proto
) && css_tryget(&memcg
->css
)) {
545 sk
->sk_cgrp
= cg_proto
;
550 EXPORT_SYMBOL(sock_update_memcg
);
552 void sock_release_memcg(struct sock
*sk
)
554 if (mem_cgroup_sockets_enabled
&& sk
->sk_cgrp
) {
555 struct mem_cgroup
*memcg
;
556 WARN_ON(!sk
->sk_cgrp
->memcg
);
557 memcg
= sk
->sk_cgrp
->memcg
;
558 css_put(&sk
->sk_cgrp
->memcg
->css
);
562 struct cg_proto
*tcp_proto_cgroup(struct mem_cgroup
*memcg
)
564 if (!memcg
|| mem_cgroup_is_root(memcg
))
567 return &memcg
->tcp_mem
.cg_proto
;
569 EXPORT_SYMBOL(tcp_proto_cgroup
);
571 static void disarm_sock_keys(struct mem_cgroup
*memcg
)
573 if (!memcg_proto_activated(&memcg
->tcp_mem
.cg_proto
))
575 static_key_slow_dec(&memcg_socket_limit_enabled
);
578 static void disarm_sock_keys(struct mem_cgroup
*memcg
)
583 #ifdef CONFIG_MEMCG_KMEM
585 * This will be the memcg's index in each cache's ->memcg_params->memcg_caches.
586 * There are two main reasons for not using the css_id for this:
587 * 1) this works better in sparse environments, where we have a lot of memcgs,
588 * but only a few kmem-limited. Or also, if we have, for instance, 200
589 * memcgs, and none but the 200th is kmem-limited, we'd have to have a
590 * 200 entry array for that.
592 * 2) In order not to violate the cgroup API, we would like to do all memory
593 * allocation in ->create(). At that point, we haven't yet allocated the
594 * css_id. Having a separate index prevents us from messing with the cgroup
597 * The current size of the caches array is stored in
598 * memcg_limited_groups_array_size. It will double each time we have to
601 static DEFINE_IDA(kmem_limited_groups
);
602 int memcg_limited_groups_array_size
;
605 * MIN_SIZE is different than 1, because we would like to avoid going through
606 * the alloc/free process all the time. In a small machine, 4 kmem-limited
607 * cgroups is a reasonable guess. In the future, it could be a parameter or
608 * tunable, but that is strictly not necessary.
610 * MAX_SIZE should be as large as the number of css_ids. Ideally, we could get
611 * this constant directly from cgroup, but it is understandable that this is
612 * better kept as an internal representation in cgroup.c. In any case, the
613 * css_id space is not getting any smaller, and we don't have to necessarily
614 * increase ours as well if it increases.
616 #define MEMCG_CACHES_MIN_SIZE 4
617 #define MEMCG_CACHES_MAX_SIZE 65535
620 * A lot of the calls to the cache allocation functions are expected to be
621 * inlined by the compiler. Since the calls to memcg_kmem_get_cache are
622 * conditional to this static branch, we'll have to allow modules that does
623 * kmem_cache_alloc and the such to see this symbol as well
625 struct static_key memcg_kmem_enabled_key
;
626 EXPORT_SYMBOL(memcg_kmem_enabled_key
);
628 static void disarm_kmem_keys(struct mem_cgroup
*memcg
)
630 if (memcg_kmem_is_active(memcg
)) {
631 static_key_slow_dec(&memcg_kmem_enabled_key
);
632 ida_simple_remove(&kmem_limited_groups
, memcg
->kmemcg_id
);
635 * This check can't live in kmem destruction function,
636 * since the charges will outlive the cgroup
638 WARN_ON(res_counter_read_u64(&memcg
->kmem
, RES_USAGE
) != 0);
641 static void disarm_kmem_keys(struct mem_cgroup
*memcg
)
644 #endif /* CONFIG_MEMCG_KMEM */
646 static void disarm_static_keys(struct mem_cgroup
*memcg
)
648 disarm_sock_keys(memcg
);
649 disarm_kmem_keys(memcg
);
652 static void drain_all_stock_async(struct mem_cgroup
*memcg
);
654 static struct mem_cgroup_per_zone
*
655 mem_cgroup_zoneinfo(struct mem_cgroup
*memcg
, int nid
, int zid
)
657 VM_BUG_ON((unsigned)nid
>= nr_node_ids
);
658 return &memcg
->nodeinfo
[nid
]->zoneinfo
[zid
];
661 struct cgroup_subsys_state
*mem_cgroup_css(struct mem_cgroup
*memcg
)
666 static struct mem_cgroup_per_zone
*
667 page_cgroup_zoneinfo(struct mem_cgroup
*memcg
, struct page
*page
)
669 int nid
= page_to_nid(page
);
670 int zid
= page_zonenum(page
);
672 return mem_cgroup_zoneinfo(memcg
, nid
, zid
);
675 static struct mem_cgroup_tree_per_zone
*
676 soft_limit_tree_node_zone(int nid
, int zid
)
678 return &soft_limit_tree
.rb_tree_per_node
[nid
]->rb_tree_per_zone
[zid
];
681 static struct mem_cgroup_tree_per_zone
*
682 soft_limit_tree_from_page(struct page
*page
)
684 int nid
= page_to_nid(page
);
685 int zid
= page_zonenum(page
);
687 return &soft_limit_tree
.rb_tree_per_node
[nid
]->rb_tree_per_zone
[zid
];
691 __mem_cgroup_insert_exceeded(struct mem_cgroup
*memcg
,
692 struct mem_cgroup_per_zone
*mz
,
693 struct mem_cgroup_tree_per_zone
*mctz
,
694 unsigned long long new_usage_in_excess
)
696 struct rb_node
**p
= &mctz
->rb_root
.rb_node
;
697 struct rb_node
*parent
= NULL
;
698 struct mem_cgroup_per_zone
*mz_node
;
703 mz
->usage_in_excess
= new_usage_in_excess
;
704 if (!mz
->usage_in_excess
)
708 mz_node
= rb_entry(parent
, struct mem_cgroup_per_zone
,
710 if (mz
->usage_in_excess
< mz_node
->usage_in_excess
)
713 * We can't avoid mem cgroups that are over their soft
714 * limit by the same amount
716 else if (mz
->usage_in_excess
>= mz_node
->usage_in_excess
)
719 rb_link_node(&mz
->tree_node
, parent
, p
);
720 rb_insert_color(&mz
->tree_node
, &mctz
->rb_root
);
725 __mem_cgroup_remove_exceeded(struct mem_cgroup
*memcg
,
726 struct mem_cgroup_per_zone
*mz
,
727 struct mem_cgroup_tree_per_zone
*mctz
)
731 rb_erase(&mz
->tree_node
, &mctz
->rb_root
);
736 mem_cgroup_remove_exceeded(struct mem_cgroup
*memcg
,
737 struct mem_cgroup_per_zone
*mz
,
738 struct mem_cgroup_tree_per_zone
*mctz
)
740 spin_lock(&mctz
->lock
);
741 __mem_cgroup_remove_exceeded(memcg
, mz
, mctz
);
742 spin_unlock(&mctz
->lock
);
746 static void mem_cgroup_update_tree(struct mem_cgroup
*memcg
, struct page
*page
)
748 unsigned long long excess
;
749 struct mem_cgroup_per_zone
*mz
;
750 struct mem_cgroup_tree_per_zone
*mctz
;
751 int nid
= page_to_nid(page
);
752 int zid
= page_zonenum(page
);
753 mctz
= soft_limit_tree_from_page(page
);
756 * Necessary to update all ancestors when hierarchy is used.
757 * because their event counter is not touched.
759 for (; memcg
; memcg
= parent_mem_cgroup(memcg
)) {
760 mz
= mem_cgroup_zoneinfo(memcg
, nid
, zid
);
761 excess
= res_counter_soft_limit_excess(&memcg
->res
);
763 * We have to update the tree if mz is on RB-tree or
764 * mem is over its softlimit.
766 if (excess
|| mz
->on_tree
) {
767 spin_lock(&mctz
->lock
);
768 /* if on-tree, remove it */
770 __mem_cgroup_remove_exceeded(memcg
, mz
, mctz
);
772 * Insert again. mz->usage_in_excess will be updated.
773 * If excess is 0, no tree ops.
775 __mem_cgroup_insert_exceeded(memcg
, mz
, mctz
, excess
);
776 spin_unlock(&mctz
->lock
);
781 static void mem_cgroup_remove_from_trees(struct mem_cgroup
*memcg
)
784 struct mem_cgroup_per_zone
*mz
;
785 struct mem_cgroup_tree_per_zone
*mctz
;
787 for_each_node(node
) {
788 for (zone
= 0; zone
< MAX_NR_ZONES
; zone
++) {
789 mz
= mem_cgroup_zoneinfo(memcg
, node
, zone
);
790 mctz
= soft_limit_tree_node_zone(node
, zone
);
791 mem_cgroup_remove_exceeded(memcg
, mz
, mctz
);
796 static struct mem_cgroup_per_zone
*
797 __mem_cgroup_largest_soft_limit_node(struct mem_cgroup_tree_per_zone
*mctz
)
799 struct rb_node
*rightmost
= NULL
;
800 struct mem_cgroup_per_zone
*mz
;
804 rightmost
= rb_last(&mctz
->rb_root
);
806 goto done
; /* Nothing to reclaim from */
808 mz
= rb_entry(rightmost
, struct mem_cgroup_per_zone
, tree_node
);
810 * Remove the node now but someone else can add it back,
811 * we will to add it back at the end of reclaim to its correct
812 * position in the tree.
814 __mem_cgroup_remove_exceeded(mz
->memcg
, mz
, mctz
);
815 if (!res_counter_soft_limit_excess(&mz
->memcg
->res
) ||
816 !css_tryget(&mz
->memcg
->css
))
822 static struct mem_cgroup_per_zone
*
823 mem_cgroup_largest_soft_limit_node(struct mem_cgroup_tree_per_zone
*mctz
)
825 struct mem_cgroup_per_zone
*mz
;
827 spin_lock(&mctz
->lock
);
828 mz
= __mem_cgroup_largest_soft_limit_node(mctz
);
829 spin_unlock(&mctz
->lock
);
834 * Implementation Note: reading percpu statistics for memcg.
836 * Both of vmstat[] and percpu_counter has threshold and do periodic
837 * synchronization to implement "quick" read. There are trade-off between
838 * reading cost and precision of value. Then, we may have a chance to implement
839 * a periodic synchronizion of counter in memcg's counter.
841 * But this _read() function is used for user interface now. The user accounts
842 * memory usage by memory cgroup and he _always_ requires exact value because
843 * he accounts memory. Even if we provide quick-and-fuzzy read, we always
844 * have to visit all online cpus and make sum. So, for now, unnecessary
845 * synchronization is not implemented. (just implemented for cpu hotplug)
847 * If there are kernel internal actions which can make use of some not-exact
848 * value, and reading all cpu value can be performance bottleneck in some
849 * common workload, threashold and synchonization as vmstat[] should be
852 static long mem_cgroup_read_stat(struct mem_cgroup
*memcg
,
853 enum mem_cgroup_stat_index idx
)
859 for_each_online_cpu(cpu
)
860 val
+= per_cpu(memcg
->stat
->count
[idx
], cpu
);
861 #ifdef CONFIG_HOTPLUG_CPU
862 spin_lock(&memcg
->pcp_counter_lock
);
863 val
+= memcg
->nocpu_base
.count
[idx
];
864 spin_unlock(&memcg
->pcp_counter_lock
);
870 static void mem_cgroup_swap_statistics(struct mem_cgroup
*memcg
,
873 int val
= (charge
) ? 1 : -1;
874 this_cpu_add(memcg
->stat
->count
[MEM_CGROUP_STAT_SWAP
], val
);
877 static unsigned long mem_cgroup_read_events(struct mem_cgroup
*memcg
,
878 enum mem_cgroup_events_index idx
)
880 unsigned long val
= 0;
883 for_each_online_cpu(cpu
)
884 val
+= per_cpu(memcg
->stat
->events
[idx
], cpu
);
885 #ifdef CONFIG_HOTPLUG_CPU
886 spin_lock(&memcg
->pcp_counter_lock
);
887 val
+= memcg
->nocpu_base
.events
[idx
];
888 spin_unlock(&memcg
->pcp_counter_lock
);
893 static void mem_cgroup_charge_statistics(struct mem_cgroup
*memcg
,
895 bool anon
, int nr_pages
)
900 * Here, RSS means 'mapped anon' and anon's SwapCache. Shmem/tmpfs is
901 * counted as CACHE even if it's on ANON LRU.
904 __this_cpu_add(memcg
->stat
->count
[MEM_CGROUP_STAT_RSS
],
907 __this_cpu_add(memcg
->stat
->count
[MEM_CGROUP_STAT_CACHE
],
910 if (PageTransHuge(page
))
911 __this_cpu_add(memcg
->stat
->count
[MEM_CGROUP_STAT_RSS_HUGE
],
914 /* pagein of a big page is an event. So, ignore page size */
916 __this_cpu_inc(memcg
->stat
->events
[MEM_CGROUP_EVENTS_PGPGIN
]);
918 __this_cpu_inc(memcg
->stat
->events
[MEM_CGROUP_EVENTS_PGPGOUT
]);
919 nr_pages
= -nr_pages
; /* for event */
922 __this_cpu_add(memcg
->stat
->nr_page_events
, nr_pages
);
928 mem_cgroup_get_lru_size(struct lruvec
*lruvec
, enum lru_list lru
)
930 struct mem_cgroup_per_zone
*mz
;
932 mz
= container_of(lruvec
, struct mem_cgroup_per_zone
, lruvec
);
933 return mz
->lru_size
[lru
];
937 mem_cgroup_zone_nr_lru_pages(struct mem_cgroup
*memcg
, int nid
, int zid
,
938 unsigned int lru_mask
)
940 struct mem_cgroup_per_zone
*mz
;
942 unsigned long ret
= 0;
944 mz
= mem_cgroup_zoneinfo(memcg
, nid
, zid
);
947 if (BIT(lru
) & lru_mask
)
948 ret
+= mz
->lru_size
[lru
];
954 mem_cgroup_node_nr_lru_pages(struct mem_cgroup
*memcg
,
955 int nid
, unsigned int lru_mask
)
960 for (zid
= 0; zid
< MAX_NR_ZONES
; zid
++)
961 total
+= mem_cgroup_zone_nr_lru_pages(memcg
,
967 static unsigned long mem_cgroup_nr_lru_pages(struct mem_cgroup
*memcg
,
968 unsigned int lru_mask
)
973 for_each_node_state(nid
, N_MEMORY
)
974 total
+= mem_cgroup_node_nr_lru_pages(memcg
, nid
, lru_mask
);
978 static bool mem_cgroup_event_ratelimit(struct mem_cgroup
*memcg
,
979 enum mem_cgroup_events_target target
)
981 unsigned long val
, next
;
983 val
= __this_cpu_read(memcg
->stat
->nr_page_events
);
984 next
= __this_cpu_read(memcg
->stat
->targets
[target
]);
985 /* from time_after() in jiffies.h */
986 if ((long)next
- (long)val
< 0) {
988 case MEM_CGROUP_TARGET_THRESH
:
989 next
= val
+ THRESHOLDS_EVENTS_TARGET
;
991 case MEM_CGROUP_TARGET_SOFTLIMIT
:
992 next
= val
+ SOFTLIMIT_EVENTS_TARGET
;
994 case MEM_CGROUP_TARGET_NUMAINFO
:
995 next
= val
+ NUMAINFO_EVENTS_TARGET
;
1000 __this_cpu_write(memcg
->stat
->targets
[target
], next
);
1007 * Check events in order.
1010 static void memcg_check_events(struct mem_cgroup
*memcg
, struct page
*page
)
1013 /* threshold event is triggered in finer grain than soft limit */
1014 if (unlikely(mem_cgroup_event_ratelimit(memcg
,
1015 MEM_CGROUP_TARGET_THRESH
))) {
1017 bool do_numainfo __maybe_unused
;
1019 do_softlimit
= mem_cgroup_event_ratelimit(memcg
,
1020 MEM_CGROUP_TARGET_SOFTLIMIT
);
1021 #if MAX_NUMNODES > 1
1022 do_numainfo
= mem_cgroup_event_ratelimit(memcg
,
1023 MEM_CGROUP_TARGET_NUMAINFO
);
1027 mem_cgroup_threshold(memcg
);
1028 if (unlikely(do_softlimit
))
1029 mem_cgroup_update_tree(memcg
, page
);
1030 #if MAX_NUMNODES > 1
1031 if (unlikely(do_numainfo
))
1032 atomic_inc(&memcg
->numainfo_events
);
1038 struct mem_cgroup
*mem_cgroup_from_cont(struct cgroup
*cont
)
1040 return mem_cgroup_from_css(cgroup_css(cont
, mem_cgroup_subsys_id
));
1043 struct mem_cgroup
*mem_cgroup_from_task(struct task_struct
*p
)
1046 * mm_update_next_owner() may clear mm->owner to NULL
1047 * if it races with swapoff, page migration, etc.
1048 * So this can be called with p == NULL.
1053 return mem_cgroup_from_css(task_css(p
, mem_cgroup_subsys_id
));
1056 struct mem_cgroup
*try_get_mem_cgroup_from_mm(struct mm_struct
*mm
)
1058 struct mem_cgroup
*memcg
= NULL
;
1063 * Because we have no locks, mm->owner's may be being moved to other
1064 * cgroup. We use css_tryget() here even if this looks
1065 * pessimistic (rather than adding locks here).
1069 memcg
= mem_cgroup_from_task(rcu_dereference(mm
->owner
));
1070 if (unlikely(!memcg
))
1072 } while (!css_tryget(&memcg
->css
));
1078 * Returns a next (in a pre-order walk) alive memcg (with elevated css
1079 * ref. count) or NULL if the whole root's subtree has been visited.
1081 * helper function to be used by mem_cgroup_iter
1083 static struct mem_cgroup
*__mem_cgroup_iter_next(struct mem_cgroup
*root
,
1084 struct mem_cgroup
*last_visited
)
1086 struct cgroup
*prev_cgroup
, *next_cgroup
;
1089 * Root is not visited by cgroup iterators so it needs an
1095 prev_cgroup
= (last_visited
== root
) ? NULL
1096 : last_visited
->css
.cgroup
;
1098 next_cgroup
= cgroup_next_descendant_pre(
1099 prev_cgroup
, root
->css
.cgroup
);
1102 * Even if we found a group we have to make sure it is
1103 * alive. css && !memcg means that the groups should be
1104 * skipped and we should continue the tree walk.
1105 * last_visited css is safe to use because it is
1106 * protected by css_get and the tree walk is rcu safe.
1109 struct mem_cgroup
*mem
= mem_cgroup_from_cont(
1111 if (css_tryget(&mem
->css
))
1114 prev_cgroup
= next_cgroup
;
1122 static void mem_cgroup_iter_invalidate(struct mem_cgroup
*root
)
1125 * When a group in the hierarchy below root is destroyed, the
1126 * hierarchy iterator can no longer be trusted since it might
1127 * have pointed to the destroyed group. Invalidate it.
1129 atomic_inc(&root
->dead_count
);
1132 static struct mem_cgroup
*
1133 mem_cgroup_iter_load(struct mem_cgroup_reclaim_iter
*iter
,
1134 struct mem_cgroup
*root
,
1137 struct mem_cgroup
*position
= NULL
;
1139 * A cgroup destruction happens in two stages: offlining and
1140 * release. They are separated by a RCU grace period.
1142 * If the iterator is valid, we may still race with an
1143 * offlining. The RCU lock ensures the object won't be
1144 * released, tryget will fail if we lost the race.
1146 *sequence
= atomic_read(&root
->dead_count
);
1147 if (iter
->last_dead_count
== *sequence
) {
1149 position
= iter
->last_visited
;
1150 if (position
&& !css_tryget(&position
->css
))
1156 static void mem_cgroup_iter_update(struct mem_cgroup_reclaim_iter
*iter
,
1157 struct mem_cgroup
*last_visited
,
1158 struct mem_cgroup
*new_position
,
1162 css_put(&last_visited
->css
);
1164 * We store the sequence count from the time @last_visited was
1165 * loaded successfully instead of rereading it here so that we
1166 * don't lose destruction events in between. We could have
1167 * raced with the destruction of @new_position after all.
1169 iter
->last_visited
= new_position
;
1171 iter
->last_dead_count
= sequence
;
1175 * mem_cgroup_iter - iterate over memory cgroup hierarchy
1176 * @root: hierarchy root
1177 * @prev: previously returned memcg, NULL on first invocation
1178 * @reclaim: cookie for shared reclaim walks, NULL for full walks
1180 * Returns references to children of the hierarchy below @root, or
1181 * @root itself, or %NULL after a full round-trip.
1183 * Caller must pass the return value in @prev on subsequent
1184 * invocations for reference counting, or use mem_cgroup_iter_break()
1185 * to cancel a hierarchy walk before the round-trip is complete.
1187 * Reclaimers can specify a zone and a priority level in @reclaim to
1188 * divide up the memcgs in the hierarchy among all concurrent
1189 * reclaimers operating on the same zone and priority.
1191 struct mem_cgroup
*mem_cgroup_iter(struct mem_cgroup
*root
,
1192 struct mem_cgroup
*prev
,
1193 struct mem_cgroup_reclaim_cookie
*reclaim
)
1195 struct mem_cgroup
*memcg
= NULL
;
1196 struct mem_cgroup
*last_visited
= NULL
;
1198 if (mem_cgroup_disabled())
1202 root
= root_mem_cgroup
;
1204 if (prev
&& !reclaim
)
1205 last_visited
= prev
;
1207 if (!root
->use_hierarchy
&& root
!= root_mem_cgroup
) {
1215 struct mem_cgroup_reclaim_iter
*uninitialized_var(iter
);
1216 int uninitialized_var(seq
);
1219 int nid
= zone_to_nid(reclaim
->zone
);
1220 int zid
= zone_idx(reclaim
->zone
);
1221 struct mem_cgroup_per_zone
*mz
;
1223 mz
= mem_cgroup_zoneinfo(root
, nid
, zid
);
1224 iter
= &mz
->reclaim_iter
[reclaim
->priority
];
1225 if (prev
&& reclaim
->generation
!= iter
->generation
) {
1226 iter
->last_visited
= NULL
;
1230 last_visited
= mem_cgroup_iter_load(iter
, root
, &seq
);
1233 memcg
= __mem_cgroup_iter_next(root
, last_visited
);
1236 mem_cgroup_iter_update(iter
, last_visited
, memcg
, seq
);
1240 else if (!prev
&& memcg
)
1241 reclaim
->generation
= iter
->generation
;
1250 if (prev
&& prev
!= root
)
1251 css_put(&prev
->css
);
1257 * mem_cgroup_iter_break - abort a hierarchy walk prematurely
1258 * @root: hierarchy root
1259 * @prev: last visited hierarchy member as returned by mem_cgroup_iter()
1261 void mem_cgroup_iter_break(struct mem_cgroup
*root
,
1262 struct mem_cgroup
*prev
)
1265 root
= root_mem_cgroup
;
1266 if (prev
&& prev
!= root
)
1267 css_put(&prev
->css
);
1271 * Iteration constructs for visiting all cgroups (under a tree). If
1272 * loops are exited prematurely (break), mem_cgroup_iter_break() must
1273 * be used for reference counting.
1275 #define for_each_mem_cgroup_tree(iter, root) \
1276 for (iter = mem_cgroup_iter(root, NULL, NULL); \
1278 iter = mem_cgroup_iter(root, iter, NULL))
1280 #define for_each_mem_cgroup(iter) \
1281 for (iter = mem_cgroup_iter(NULL, NULL, NULL); \
1283 iter = mem_cgroup_iter(NULL, iter, NULL))
1285 void __mem_cgroup_count_vm_event(struct mm_struct
*mm
, enum vm_event_item idx
)
1287 struct mem_cgroup
*memcg
;
1290 memcg
= mem_cgroup_from_task(rcu_dereference(mm
->owner
));
1291 if (unlikely(!memcg
))
1296 this_cpu_inc(memcg
->stat
->events
[MEM_CGROUP_EVENTS_PGFAULT
]);
1299 this_cpu_inc(memcg
->stat
->events
[MEM_CGROUP_EVENTS_PGMAJFAULT
]);
1307 EXPORT_SYMBOL(__mem_cgroup_count_vm_event
);
1310 * mem_cgroup_zone_lruvec - get the lru list vector for a zone and memcg
1311 * @zone: zone of the wanted lruvec
1312 * @memcg: memcg of the wanted lruvec
1314 * Returns the lru list vector holding pages for the given @zone and
1315 * @mem. This can be the global zone lruvec, if the memory controller
1318 struct lruvec
*mem_cgroup_zone_lruvec(struct zone
*zone
,
1319 struct mem_cgroup
*memcg
)
1321 struct mem_cgroup_per_zone
*mz
;
1322 struct lruvec
*lruvec
;
1324 if (mem_cgroup_disabled()) {
1325 lruvec
= &zone
->lruvec
;
1329 mz
= mem_cgroup_zoneinfo(memcg
, zone_to_nid(zone
), zone_idx(zone
));
1330 lruvec
= &mz
->lruvec
;
1333 * Since a node can be onlined after the mem_cgroup was created,
1334 * we have to be prepared to initialize lruvec->zone here;
1335 * and if offlined then reonlined, we need to reinitialize it.
1337 if (unlikely(lruvec
->zone
!= zone
))
1338 lruvec
->zone
= zone
;
1343 * Following LRU functions are allowed to be used without PCG_LOCK.
1344 * Operations are called by routine of global LRU independently from memcg.
1345 * What we have to take care of here is validness of pc->mem_cgroup.
1347 * Changes to pc->mem_cgroup happens when
1350 * In typical case, "charge" is done before add-to-lru. Exception is SwapCache.
1351 * It is added to LRU before charge.
1352 * If PCG_USED bit is not set, page_cgroup is not added to this private LRU.
1353 * When moving account, the page is not on LRU. It's isolated.
1357 * mem_cgroup_page_lruvec - return lruvec for adding an lru page
1359 * @zone: zone of the page
1361 struct lruvec
*mem_cgroup_page_lruvec(struct page
*page
, struct zone
*zone
)
1363 struct mem_cgroup_per_zone
*mz
;
1364 struct mem_cgroup
*memcg
;
1365 struct page_cgroup
*pc
;
1366 struct lruvec
*lruvec
;
1368 if (mem_cgroup_disabled()) {
1369 lruvec
= &zone
->lruvec
;
1373 pc
= lookup_page_cgroup(page
);
1374 memcg
= pc
->mem_cgroup
;
1377 * Surreptitiously switch any uncharged offlist page to root:
1378 * an uncharged page off lru does nothing to secure
1379 * its former mem_cgroup from sudden removal.
1381 * Our caller holds lru_lock, and PageCgroupUsed is updated
1382 * under page_cgroup lock: between them, they make all uses
1383 * of pc->mem_cgroup safe.
1385 if (!PageLRU(page
) && !PageCgroupUsed(pc
) && memcg
!= root_mem_cgroup
)
1386 pc
->mem_cgroup
= memcg
= root_mem_cgroup
;
1388 mz
= page_cgroup_zoneinfo(memcg
, page
);
1389 lruvec
= &mz
->lruvec
;
1392 * Since a node can be onlined after the mem_cgroup was created,
1393 * we have to be prepared to initialize lruvec->zone here;
1394 * and if offlined then reonlined, we need to reinitialize it.
1396 if (unlikely(lruvec
->zone
!= zone
))
1397 lruvec
->zone
= zone
;
1402 * mem_cgroup_update_lru_size - account for adding or removing an lru page
1403 * @lruvec: mem_cgroup per zone lru vector
1404 * @lru: index of lru list the page is sitting on
1405 * @nr_pages: positive when adding or negative when removing
1407 * This function must be called when a page is added to or removed from an
1410 void mem_cgroup_update_lru_size(struct lruvec
*lruvec
, enum lru_list lru
,
1413 struct mem_cgroup_per_zone
*mz
;
1414 unsigned long *lru_size
;
1416 if (mem_cgroup_disabled())
1419 mz
= container_of(lruvec
, struct mem_cgroup_per_zone
, lruvec
);
1420 lru_size
= mz
->lru_size
+ lru
;
1421 *lru_size
+= nr_pages
;
1422 VM_BUG_ON((long)(*lru_size
) < 0);
1426 * Checks whether given mem is same or in the root_mem_cgroup's
1429 bool __mem_cgroup_same_or_subtree(const struct mem_cgroup
*root_memcg
,
1430 struct mem_cgroup
*memcg
)
1432 if (root_memcg
== memcg
)
1434 if (!root_memcg
->use_hierarchy
|| !memcg
)
1436 return css_is_ancestor(&memcg
->css
, &root_memcg
->css
);
1439 static bool mem_cgroup_same_or_subtree(const struct mem_cgroup
*root_memcg
,
1440 struct mem_cgroup
*memcg
)
1445 ret
= __mem_cgroup_same_or_subtree(root_memcg
, memcg
);
1450 bool task_in_mem_cgroup(struct task_struct
*task
,
1451 const struct mem_cgroup
*memcg
)
1453 struct mem_cgroup
*curr
= NULL
;
1454 struct task_struct
*p
;
1457 p
= find_lock_task_mm(task
);
1459 curr
= try_get_mem_cgroup_from_mm(p
->mm
);
1463 * All threads may have already detached their mm's, but the oom
1464 * killer still needs to detect if they have already been oom
1465 * killed to prevent needlessly killing additional tasks.
1468 curr
= mem_cgroup_from_task(task
);
1470 css_get(&curr
->css
);
1476 * We should check use_hierarchy of "memcg" not "curr". Because checking
1477 * use_hierarchy of "curr" here make this function true if hierarchy is
1478 * enabled in "curr" and "curr" is a child of "memcg" in *cgroup*
1479 * hierarchy(even if use_hierarchy is disabled in "memcg").
1481 ret
= mem_cgroup_same_or_subtree(memcg
, curr
);
1482 css_put(&curr
->css
);
1486 int mem_cgroup_inactive_anon_is_low(struct lruvec
*lruvec
)
1488 unsigned long inactive_ratio
;
1489 unsigned long inactive
;
1490 unsigned long active
;
1493 inactive
= mem_cgroup_get_lru_size(lruvec
, LRU_INACTIVE_ANON
);
1494 active
= mem_cgroup_get_lru_size(lruvec
, LRU_ACTIVE_ANON
);
1496 gb
= (inactive
+ active
) >> (30 - PAGE_SHIFT
);
1498 inactive_ratio
= int_sqrt(10 * gb
);
1502 return inactive
* inactive_ratio
< active
;
1505 #define mem_cgroup_from_res_counter(counter, member) \
1506 container_of(counter, struct mem_cgroup, member)
1509 * mem_cgroup_margin - calculate chargeable space of a memory cgroup
1510 * @memcg: the memory cgroup
1512 * Returns the maximum amount of memory @mem can be charged with, in
1515 static unsigned long mem_cgroup_margin(struct mem_cgroup
*memcg
)
1517 unsigned long long margin
;
1519 margin
= res_counter_margin(&memcg
->res
);
1520 if (do_swap_account
)
1521 margin
= min(margin
, res_counter_margin(&memcg
->memsw
));
1522 return margin
>> PAGE_SHIFT
;
1525 int mem_cgroup_swappiness(struct mem_cgroup
*memcg
)
1527 struct cgroup
*cgrp
= memcg
->css
.cgroup
;
1530 if (cgrp
->parent
== NULL
)
1531 return vm_swappiness
;
1533 return memcg
->swappiness
;
1537 * memcg->moving_account is used for checking possibility that some thread is
1538 * calling move_account(). When a thread on CPU-A starts moving pages under
1539 * a memcg, other threads should check memcg->moving_account under
1540 * rcu_read_lock(), like this:
1544 * memcg->moving_account+1 if (memcg->mocing_account)
1546 * synchronize_rcu() update something.
1551 /* for quick checking without looking up memcg */
1552 atomic_t memcg_moving __read_mostly
;
1554 static void mem_cgroup_start_move(struct mem_cgroup
*memcg
)
1556 atomic_inc(&memcg_moving
);
1557 atomic_inc(&memcg
->moving_account
);
1561 static void mem_cgroup_end_move(struct mem_cgroup
*memcg
)
1564 * Now, mem_cgroup_clear_mc() may call this function with NULL.
1565 * We check NULL in callee rather than caller.
1568 atomic_dec(&memcg_moving
);
1569 atomic_dec(&memcg
->moving_account
);
1574 * 2 routines for checking "mem" is under move_account() or not.
1576 * mem_cgroup_stolen() - checking whether a cgroup is mc.from or not. This
1577 * is used for avoiding races in accounting. If true,
1578 * pc->mem_cgroup may be overwritten.
1580 * mem_cgroup_under_move() - checking a cgroup is mc.from or mc.to or
1581 * under hierarchy of moving cgroups. This is for
1582 * waiting at hith-memory prressure caused by "move".
1585 static bool mem_cgroup_stolen(struct mem_cgroup
*memcg
)
1587 VM_BUG_ON(!rcu_read_lock_held());
1588 return atomic_read(&memcg
->moving_account
) > 0;
1591 static bool mem_cgroup_under_move(struct mem_cgroup
*memcg
)
1593 struct mem_cgroup
*from
;
1594 struct mem_cgroup
*to
;
1597 * Unlike task_move routines, we access mc.to, mc.from not under
1598 * mutual exclusion by cgroup_mutex. Here, we take spinlock instead.
1600 spin_lock(&mc
.lock
);
1606 ret
= mem_cgroup_same_or_subtree(memcg
, from
)
1607 || mem_cgroup_same_or_subtree(memcg
, to
);
1609 spin_unlock(&mc
.lock
);
1613 static bool mem_cgroup_wait_acct_move(struct mem_cgroup
*memcg
)
1615 if (mc
.moving_task
&& current
!= mc
.moving_task
) {
1616 if (mem_cgroup_under_move(memcg
)) {
1618 prepare_to_wait(&mc
.waitq
, &wait
, TASK_INTERRUPTIBLE
);
1619 /* moving charge context might have finished. */
1622 finish_wait(&mc
.waitq
, &wait
);
1630 * Take this lock when
1631 * - a code tries to modify page's memcg while it's USED.
1632 * - a code tries to modify page state accounting in a memcg.
1633 * see mem_cgroup_stolen(), too.
1635 static void move_lock_mem_cgroup(struct mem_cgroup
*memcg
,
1636 unsigned long *flags
)
1638 spin_lock_irqsave(&memcg
->move_lock
, *flags
);
1641 static void move_unlock_mem_cgroup(struct mem_cgroup
*memcg
,
1642 unsigned long *flags
)
1644 spin_unlock_irqrestore(&memcg
->move_lock
, *flags
);
1647 #define K(x) ((x) << (PAGE_SHIFT-10))
1649 * mem_cgroup_print_oom_info: Print OOM information relevant to memory controller.
1650 * @memcg: The memory cgroup that went over limit
1651 * @p: Task that is going to be killed
1653 * NOTE: @memcg and @p's mem_cgroup can be different when hierarchy is
1656 void mem_cgroup_print_oom_info(struct mem_cgroup
*memcg
, struct task_struct
*p
)
1658 struct cgroup
*task_cgrp
;
1659 struct cgroup
*mem_cgrp
;
1661 * Need a buffer in BSS, can't rely on allocations. The code relies
1662 * on the assumption that OOM is serialized for memory controller.
1663 * If this assumption is broken, revisit this code.
1665 static char memcg_name
[PATH_MAX
];
1667 struct mem_cgroup
*iter
;
1675 mem_cgrp
= memcg
->css
.cgroup
;
1676 task_cgrp
= task_cgroup(p
, mem_cgroup_subsys_id
);
1678 ret
= cgroup_path(task_cgrp
, memcg_name
, PATH_MAX
);
1681 * Unfortunately, we are unable to convert to a useful name
1682 * But we'll still print out the usage information
1689 pr_info("Task in %s killed", memcg_name
);
1692 ret
= cgroup_path(mem_cgrp
, memcg_name
, PATH_MAX
);
1700 * Continues from above, so we don't need an KERN_ level
1702 pr_cont(" as a result of limit of %s\n", memcg_name
);
1705 pr_info("memory: usage %llukB, limit %llukB, failcnt %llu\n",
1706 res_counter_read_u64(&memcg
->res
, RES_USAGE
) >> 10,
1707 res_counter_read_u64(&memcg
->res
, RES_LIMIT
) >> 10,
1708 res_counter_read_u64(&memcg
->res
, RES_FAILCNT
));
1709 pr_info("memory+swap: usage %llukB, limit %llukB, failcnt %llu\n",
1710 res_counter_read_u64(&memcg
->memsw
, RES_USAGE
) >> 10,
1711 res_counter_read_u64(&memcg
->memsw
, RES_LIMIT
) >> 10,
1712 res_counter_read_u64(&memcg
->memsw
, RES_FAILCNT
));
1713 pr_info("kmem: usage %llukB, limit %llukB, failcnt %llu\n",
1714 res_counter_read_u64(&memcg
->kmem
, RES_USAGE
) >> 10,
1715 res_counter_read_u64(&memcg
->kmem
, RES_LIMIT
) >> 10,
1716 res_counter_read_u64(&memcg
->kmem
, RES_FAILCNT
));
1718 for_each_mem_cgroup_tree(iter
, memcg
) {
1719 pr_info("Memory cgroup stats");
1722 ret
= cgroup_path(iter
->css
.cgroup
, memcg_name
, PATH_MAX
);
1724 pr_cont(" for %s", memcg_name
);
1728 for (i
= 0; i
< MEM_CGROUP_STAT_NSTATS
; i
++) {
1729 if (i
== MEM_CGROUP_STAT_SWAP
&& !do_swap_account
)
1731 pr_cont(" %s:%ldKB", mem_cgroup_stat_names
[i
],
1732 K(mem_cgroup_read_stat(iter
, i
)));
1735 for (i
= 0; i
< NR_LRU_LISTS
; i
++)
1736 pr_cont(" %s:%luKB", mem_cgroup_lru_names
[i
],
1737 K(mem_cgroup_nr_lru_pages(iter
, BIT(i
))));
1744 * This function returns the number of memcg under hierarchy tree. Returns
1745 * 1(self count) if no children.
1747 static int mem_cgroup_count_children(struct mem_cgroup
*memcg
)
1750 struct mem_cgroup
*iter
;
1752 for_each_mem_cgroup_tree(iter
, memcg
)
1758 * Return the memory (and swap, if configured) limit for a memcg.
1760 static u64
mem_cgroup_get_limit(struct mem_cgroup
*memcg
)
1764 limit
= res_counter_read_u64(&memcg
->res
, RES_LIMIT
);
1767 * Do not consider swap space if we cannot swap due to swappiness
1769 if (mem_cgroup_swappiness(memcg
)) {
1772 limit
+= total_swap_pages
<< PAGE_SHIFT
;
1773 memsw
= res_counter_read_u64(&memcg
->memsw
, RES_LIMIT
);
1776 * If memsw is finite and limits the amount of swap space
1777 * available to this memcg, return that limit.
1779 limit
= min(limit
, memsw
);
1785 static void mem_cgroup_out_of_memory(struct mem_cgroup
*memcg
, gfp_t gfp_mask
,
1788 struct mem_cgroup
*iter
;
1789 unsigned long chosen_points
= 0;
1790 unsigned long totalpages
;
1791 unsigned int points
= 0;
1792 struct task_struct
*chosen
= NULL
;
1795 * If current has a pending SIGKILL or is exiting, then automatically
1796 * select it. The goal is to allow it to allocate so that it may
1797 * quickly exit and free its memory.
1799 if (fatal_signal_pending(current
) || current
->flags
& PF_EXITING
) {
1800 set_thread_flag(TIF_MEMDIE
);
1804 check_panic_on_oom(CONSTRAINT_MEMCG
, gfp_mask
, order
, NULL
);
1805 totalpages
= mem_cgroup_get_limit(memcg
) >> PAGE_SHIFT
? : 1;
1806 for_each_mem_cgroup_tree(iter
, memcg
) {
1807 struct cgroup
*cgroup
= iter
->css
.cgroup
;
1808 struct cgroup_iter it
;
1809 struct task_struct
*task
;
1811 cgroup_iter_start(cgroup
, &it
);
1812 while ((task
= cgroup_iter_next(cgroup
, &it
))) {
1813 switch (oom_scan_process_thread(task
, totalpages
, NULL
,
1815 case OOM_SCAN_SELECT
:
1817 put_task_struct(chosen
);
1819 chosen_points
= ULONG_MAX
;
1820 get_task_struct(chosen
);
1822 case OOM_SCAN_CONTINUE
:
1824 case OOM_SCAN_ABORT
:
1825 cgroup_iter_end(cgroup
, &it
);
1826 mem_cgroup_iter_break(memcg
, iter
);
1828 put_task_struct(chosen
);
1833 points
= oom_badness(task
, memcg
, NULL
, totalpages
);
1834 if (points
> chosen_points
) {
1836 put_task_struct(chosen
);
1838 chosen_points
= points
;
1839 get_task_struct(chosen
);
1842 cgroup_iter_end(cgroup
, &it
);
1847 points
= chosen_points
* 1000 / totalpages
;
1848 oom_kill_process(chosen
, gfp_mask
, order
, points
, totalpages
, memcg
,
1849 NULL
, "Memory cgroup out of memory");
1852 static unsigned long mem_cgroup_reclaim(struct mem_cgroup
*memcg
,
1854 unsigned long flags
)
1856 unsigned long total
= 0;
1857 bool noswap
= false;
1860 if (flags
& MEM_CGROUP_RECLAIM_NOSWAP
)
1862 if (!(flags
& MEM_CGROUP_RECLAIM_SHRINK
) && memcg
->memsw_is_minimum
)
1865 for (loop
= 0; loop
< MEM_CGROUP_MAX_RECLAIM_LOOPS
; loop
++) {
1867 drain_all_stock_async(memcg
);
1868 total
+= try_to_free_mem_cgroup_pages(memcg
, gfp_mask
, noswap
);
1870 * Allow limit shrinkers, which are triggered directly
1871 * by userspace, to catch signals and stop reclaim
1872 * after minimal progress, regardless of the margin.
1874 if (total
&& (flags
& MEM_CGROUP_RECLAIM_SHRINK
))
1876 if (mem_cgroup_margin(memcg
))
1879 * If nothing was reclaimed after two attempts, there
1880 * may be no reclaimable pages in this hierarchy.
1889 * test_mem_cgroup_node_reclaimable
1890 * @memcg: the target memcg
1891 * @nid: the node ID to be checked.
1892 * @noswap : specify true here if the user wants flle only information.
1894 * This function returns whether the specified memcg contains any
1895 * reclaimable pages on a node. Returns true if there are any reclaimable
1896 * pages in the node.
1898 static bool test_mem_cgroup_node_reclaimable(struct mem_cgroup
*memcg
,
1899 int nid
, bool noswap
)
1901 if (mem_cgroup_node_nr_lru_pages(memcg
, nid
, LRU_ALL_FILE
))
1903 if (noswap
|| !total_swap_pages
)
1905 if (mem_cgroup_node_nr_lru_pages(memcg
, nid
, LRU_ALL_ANON
))
1910 #if MAX_NUMNODES > 1
1913 * Always updating the nodemask is not very good - even if we have an empty
1914 * list or the wrong list here, we can start from some node and traverse all
1915 * nodes based on the zonelist. So update the list loosely once per 10 secs.
1918 static void mem_cgroup_may_update_nodemask(struct mem_cgroup
*memcg
)
1922 * numainfo_events > 0 means there was at least NUMAINFO_EVENTS_TARGET
1923 * pagein/pageout changes since the last update.
1925 if (!atomic_read(&memcg
->numainfo_events
))
1927 if (atomic_inc_return(&memcg
->numainfo_updating
) > 1)
1930 /* make a nodemask where this memcg uses memory from */
1931 memcg
->scan_nodes
= node_states
[N_MEMORY
];
1933 for_each_node_mask(nid
, node_states
[N_MEMORY
]) {
1935 if (!test_mem_cgroup_node_reclaimable(memcg
, nid
, false))
1936 node_clear(nid
, memcg
->scan_nodes
);
1939 atomic_set(&memcg
->numainfo_events
, 0);
1940 atomic_set(&memcg
->numainfo_updating
, 0);
1944 * Selecting a node where we start reclaim from. Because what we need is just
1945 * reducing usage counter, start from anywhere is O,K. Considering
1946 * memory reclaim from current node, there are pros. and cons.
1948 * Freeing memory from current node means freeing memory from a node which
1949 * we'll use or we've used. So, it may make LRU bad. And if several threads
1950 * hit limits, it will see a contention on a node. But freeing from remote
1951 * node means more costs for memory reclaim because of memory latency.
1953 * Now, we use round-robin. Better algorithm is welcomed.
1955 int mem_cgroup_select_victim_node(struct mem_cgroup
*memcg
)
1959 mem_cgroup_may_update_nodemask(memcg
);
1960 node
= memcg
->last_scanned_node
;
1962 node
= next_node(node
, memcg
->scan_nodes
);
1963 if (node
== MAX_NUMNODES
)
1964 node
= first_node(memcg
->scan_nodes
);
1966 * We call this when we hit limit, not when pages are added to LRU.
1967 * No LRU may hold pages because all pages are UNEVICTABLE or
1968 * memcg is too small and all pages are not on LRU. In that case,
1969 * we use curret node.
1971 if (unlikely(node
== MAX_NUMNODES
))
1972 node
= numa_node_id();
1974 memcg
->last_scanned_node
= node
;
1979 * Check all nodes whether it contains reclaimable pages or not.
1980 * For quick scan, we make use of scan_nodes. This will allow us to skip
1981 * unused nodes. But scan_nodes is lazily updated and may not cotain
1982 * enough new information. We need to do double check.
1984 static bool mem_cgroup_reclaimable(struct mem_cgroup
*memcg
, bool noswap
)
1989 * quick check...making use of scan_node.
1990 * We can skip unused nodes.
1992 if (!nodes_empty(memcg
->scan_nodes
)) {
1993 for (nid
= first_node(memcg
->scan_nodes
);
1995 nid
= next_node(nid
, memcg
->scan_nodes
)) {
1997 if (test_mem_cgroup_node_reclaimable(memcg
, nid
, noswap
))
2002 * Check rest of nodes.
2004 for_each_node_state(nid
, N_MEMORY
) {
2005 if (node_isset(nid
, memcg
->scan_nodes
))
2007 if (test_mem_cgroup_node_reclaimable(memcg
, nid
, noswap
))
2014 int mem_cgroup_select_victim_node(struct mem_cgroup
*memcg
)
2019 static bool mem_cgroup_reclaimable(struct mem_cgroup
*memcg
, bool noswap
)
2021 return test_mem_cgroup_node_reclaimable(memcg
, 0, noswap
);
2025 static int mem_cgroup_soft_reclaim(struct mem_cgroup
*root_memcg
,
2028 unsigned long *total_scanned
)
2030 struct mem_cgroup
*victim
= NULL
;
2033 unsigned long excess
;
2034 unsigned long nr_scanned
;
2035 struct mem_cgroup_reclaim_cookie reclaim
= {
2040 excess
= res_counter_soft_limit_excess(&root_memcg
->res
) >> PAGE_SHIFT
;
2043 victim
= mem_cgroup_iter(root_memcg
, victim
, &reclaim
);
2048 * If we have not been able to reclaim
2049 * anything, it might because there are
2050 * no reclaimable pages under this hierarchy
2055 * We want to do more targeted reclaim.
2056 * excess >> 2 is not to excessive so as to
2057 * reclaim too much, nor too less that we keep
2058 * coming back to reclaim from this cgroup
2060 if (total
>= (excess
>> 2) ||
2061 (loop
> MEM_CGROUP_MAX_RECLAIM_LOOPS
))
2066 if (!mem_cgroup_reclaimable(victim
, false))
2068 total
+= mem_cgroup_shrink_node_zone(victim
, gfp_mask
, false,
2070 *total_scanned
+= nr_scanned
;
2071 if (!res_counter_soft_limit_excess(&root_memcg
->res
))
2074 mem_cgroup_iter_break(root_memcg
, victim
);
2079 * Check OOM-Killer is already running under our hierarchy.
2080 * If someone is running, return false.
2081 * Has to be called with memcg_oom_lock
2083 static bool mem_cgroup_oom_lock(struct mem_cgroup
*memcg
)
2085 struct mem_cgroup
*iter
, *failed
= NULL
;
2087 for_each_mem_cgroup_tree(iter
, memcg
) {
2088 if (iter
->oom_lock
) {
2090 * this subtree of our hierarchy is already locked
2091 * so we cannot give a lock.
2094 mem_cgroup_iter_break(memcg
, iter
);
2097 iter
->oom_lock
= true;
2104 * OK, we failed to lock the whole subtree so we have to clean up
2105 * what we set up to the failing subtree
2107 for_each_mem_cgroup_tree(iter
, memcg
) {
2108 if (iter
== failed
) {
2109 mem_cgroup_iter_break(memcg
, iter
);
2112 iter
->oom_lock
= false;
2118 * Has to be called with memcg_oom_lock
2120 static int mem_cgroup_oom_unlock(struct mem_cgroup
*memcg
)
2122 struct mem_cgroup
*iter
;
2124 for_each_mem_cgroup_tree(iter
, memcg
)
2125 iter
->oom_lock
= false;
2129 static void mem_cgroup_mark_under_oom(struct mem_cgroup
*memcg
)
2131 struct mem_cgroup
*iter
;
2133 for_each_mem_cgroup_tree(iter
, memcg
)
2134 atomic_inc(&iter
->under_oom
);
2137 static void mem_cgroup_unmark_under_oom(struct mem_cgroup
*memcg
)
2139 struct mem_cgroup
*iter
;
2142 * When a new child is created while the hierarchy is under oom,
2143 * mem_cgroup_oom_lock() may not be called. We have to use
2144 * atomic_add_unless() here.
2146 for_each_mem_cgroup_tree(iter
, memcg
)
2147 atomic_add_unless(&iter
->under_oom
, -1, 0);
2150 static DEFINE_SPINLOCK(memcg_oom_lock
);
2151 static DECLARE_WAIT_QUEUE_HEAD(memcg_oom_waitq
);
2153 struct oom_wait_info
{
2154 struct mem_cgroup
*memcg
;
2158 static int memcg_oom_wake_function(wait_queue_t
*wait
,
2159 unsigned mode
, int sync
, void *arg
)
2161 struct mem_cgroup
*wake_memcg
= (struct mem_cgroup
*)arg
;
2162 struct mem_cgroup
*oom_wait_memcg
;
2163 struct oom_wait_info
*oom_wait_info
;
2165 oom_wait_info
= container_of(wait
, struct oom_wait_info
, wait
);
2166 oom_wait_memcg
= oom_wait_info
->memcg
;
2169 * Both of oom_wait_info->memcg and wake_memcg are stable under us.
2170 * Then we can use css_is_ancestor without taking care of RCU.
2172 if (!mem_cgroup_same_or_subtree(oom_wait_memcg
, wake_memcg
)
2173 && !mem_cgroup_same_or_subtree(wake_memcg
, oom_wait_memcg
))
2175 return autoremove_wake_function(wait
, mode
, sync
, arg
);
2178 static void memcg_wakeup_oom(struct mem_cgroup
*memcg
)
2180 /* for filtering, pass "memcg" as argument. */
2181 __wake_up(&memcg_oom_waitq
, TASK_NORMAL
, 0, memcg
);
2184 static void memcg_oom_recover(struct mem_cgroup
*memcg
)
2186 if (memcg
&& atomic_read(&memcg
->under_oom
))
2187 memcg_wakeup_oom(memcg
);
2191 * try to call OOM killer. returns false if we should exit memory-reclaim loop.
2193 static bool mem_cgroup_handle_oom(struct mem_cgroup
*memcg
, gfp_t mask
,
2196 struct oom_wait_info owait
;
2197 bool locked
, need_to_kill
;
2199 owait
.memcg
= memcg
;
2200 owait
.wait
.flags
= 0;
2201 owait
.wait
.func
= memcg_oom_wake_function
;
2202 owait
.wait
.private = current
;
2203 INIT_LIST_HEAD(&owait
.wait
.task_list
);
2204 need_to_kill
= true;
2205 mem_cgroup_mark_under_oom(memcg
);
2207 /* At first, try to OOM lock hierarchy under memcg.*/
2208 spin_lock(&memcg_oom_lock
);
2209 locked
= mem_cgroup_oom_lock(memcg
);
2211 * Even if signal_pending(), we can't quit charge() loop without
2212 * accounting. So, UNINTERRUPTIBLE is appropriate. But SIGKILL
2213 * under OOM is always welcomed, use TASK_KILLABLE here.
2215 prepare_to_wait(&memcg_oom_waitq
, &owait
.wait
, TASK_KILLABLE
);
2216 if (!locked
|| memcg
->oom_kill_disable
)
2217 need_to_kill
= false;
2219 mem_cgroup_oom_notify(memcg
);
2220 spin_unlock(&memcg_oom_lock
);
2223 finish_wait(&memcg_oom_waitq
, &owait
.wait
);
2224 mem_cgroup_out_of_memory(memcg
, mask
, order
);
2227 finish_wait(&memcg_oom_waitq
, &owait
.wait
);
2229 spin_lock(&memcg_oom_lock
);
2231 mem_cgroup_oom_unlock(memcg
);
2232 memcg_wakeup_oom(memcg
);
2233 spin_unlock(&memcg_oom_lock
);
2235 mem_cgroup_unmark_under_oom(memcg
);
2237 if (test_thread_flag(TIF_MEMDIE
) || fatal_signal_pending(current
))
2239 /* Give chance to dying process */
2240 schedule_timeout_uninterruptible(1);
2245 * Currently used to update mapped file statistics, but the routine can be
2246 * generalized to update other statistics as well.
2248 * Notes: Race condition
2250 * We usually use page_cgroup_lock() for accessing page_cgroup member but
2251 * it tends to be costly. But considering some conditions, we doesn't need
2252 * to do so _always_.
2254 * Considering "charge", lock_page_cgroup() is not required because all
2255 * file-stat operations happen after a page is attached to radix-tree. There
2256 * are no race with "charge".
2258 * Considering "uncharge", we know that memcg doesn't clear pc->mem_cgroup
2259 * at "uncharge" intentionally. So, we always see valid pc->mem_cgroup even
2260 * if there are race with "uncharge". Statistics itself is properly handled
2263 * Considering "move", this is an only case we see a race. To make the race
2264 * small, we check mm->moving_account and detect there are possibility of race
2265 * If there is, we take a lock.
2268 void __mem_cgroup_begin_update_page_stat(struct page
*page
,
2269 bool *locked
, unsigned long *flags
)
2271 struct mem_cgroup
*memcg
;
2272 struct page_cgroup
*pc
;
2274 pc
= lookup_page_cgroup(page
);
2276 memcg
= pc
->mem_cgroup
;
2277 if (unlikely(!memcg
|| !PageCgroupUsed(pc
)))
2280 * If this memory cgroup is not under account moving, we don't
2281 * need to take move_lock_mem_cgroup(). Because we already hold
2282 * rcu_read_lock(), any calls to move_account will be delayed until
2283 * rcu_read_unlock() if mem_cgroup_stolen() == true.
2285 if (!mem_cgroup_stolen(memcg
))
2288 move_lock_mem_cgroup(memcg
, flags
);
2289 if (memcg
!= pc
->mem_cgroup
|| !PageCgroupUsed(pc
)) {
2290 move_unlock_mem_cgroup(memcg
, flags
);
2296 void __mem_cgroup_end_update_page_stat(struct page
*page
, unsigned long *flags
)
2298 struct page_cgroup
*pc
= lookup_page_cgroup(page
);
2301 * It's guaranteed that pc->mem_cgroup never changes while
2302 * lock is held because a routine modifies pc->mem_cgroup
2303 * should take move_lock_mem_cgroup().
2305 move_unlock_mem_cgroup(pc
->mem_cgroup
, flags
);
2308 void mem_cgroup_update_page_stat(struct page
*page
,
2309 enum mem_cgroup_page_stat_item idx
, int val
)
2311 struct mem_cgroup
*memcg
;
2312 struct page_cgroup
*pc
= lookup_page_cgroup(page
);
2313 unsigned long uninitialized_var(flags
);
2315 if (mem_cgroup_disabled())
2318 memcg
= pc
->mem_cgroup
;
2319 if (unlikely(!memcg
|| !PageCgroupUsed(pc
)))
2323 case MEMCG_NR_FILE_MAPPED
:
2324 idx
= MEM_CGROUP_STAT_FILE_MAPPED
;
2330 this_cpu_add(memcg
->stat
->count
[idx
], val
);
2334 * size of first charge trial. "32" comes from vmscan.c's magic value.
2335 * TODO: maybe necessary to use big numbers in big irons.
2337 #define CHARGE_BATCH 32U
2338 struct memcg_stock_pcp
{
2339 struct mem_cgroup
*cached
; /* this never be root cgroup */
2340 unsigned int nr_pages
;
2341 struct work_struct work
;
2342 unsigned long flags
;
2343 #define FLUSHING_CACHED_CHARGE 0
2345 static DEFINE_PER_CPU(struct memcg_stock_pcp
, memcg_stock
);
2346 static DEFINE_MUTEX(percpu_charge_mutex
);
2349 * consume_stock: Try to consume stocked charge on this cpu.
2350 * @memcg: memcg to consume from.
2351 * @nr_pages: how many pages to charge.
2353 * The charges will only happen if @memcg matches the current cpu's memcg
2354 * stock, and at least @nr_pages are available in that stock. Failure to
2355 * service an allocation will refill the stock.
2357 * returns true if successful, false otherwise.
2359 static bool consume_stock(struct mem_cgroup
*memcg
, unsigned int nr_pages
)
2361 struct memcg_stock_pcp
*stock
;
2364 if (nr_pages
> CHARGE_BATCH
)
2367 stock
= &get_cpu_var(memcg_stock
);
2368 if (memcg
== stock
->cached
&& stock
->nr_pages
>= nr_pages
)
2369 stock
->nr_pages
-= nr_pages
;
2370 else /* need to call res_counter_charge */
2372 put_cpu_var(memcg_stock
);
2377 * Returns stocks cached in percpu to res_counter and reset cached information.
2379 static void drain_stock(struct memcg_stock_pcp
*stock
)
2381 struct mem_cgroup
*old
= stock
->cached
;
2383 if (stock
->nr_pages
) {
2384 unsigned long bytes
= stock
->nr_pages
* PAGE_SIZE
;
2386 res_counter_uncharge(&old
->res
, bytes
);
2387 if (do_swap_account
)
2388 res_counter_uncharge(&old
->memsw
, bytes
);
2389 stock
->nr_pages
= 0;
2391 stock
->cached
= NULL
;
2395 * This must be called under preempt disabled or must be called by
2396 * a thread which is pinned to local cpu.
2398 static void drain_local_stock(struct work_struct
*dummy
)
2400 struct memcg_stock_pcp
*stock
= &__get_cpu_var(memcg_stock
);
2402 clear_bit(FLUSHING_CACHED_CHARGE
, &stock
->flags
);
2405 static void __init
memcg_stock_init(void)
2409 for_each_possible_cpu(cpu
) {
2410 struct memcg_stock_pcp
*stock
=
2411 &per_cpu(memcg_stock
, cpu
);
2412 INIT_WORK(&stock
->work
, drain_local_stock
);
2417 * Cache charges(val) which is from res_counter, to local per_cpu area.
2418 * This will be consumed by consume_stock() function, later.
2420 static void refill_stock(struct mem_cgroup
*memcg
, unsigned int nr_pages
)
2422 struct memcg_stock_pcp
*stock
= &get_cpu_var(memcg_stock
);
2424 if (stock
->cached
!= memcg
) { /* reset if necessary */
2426 stock
->cached
= memcg
;
2428 stock
->nr_pages
+= nr_pages
;
2429 put_cpu_var(memcg_stock
);
2433 * Drains all per-CPU charge caches for given root_memcg resp. subtree
2434 * of the hierarchy under it. sync flag says whether we should block
2435 * until the work is done.
2437 static void drain_all_stock(struct mem_cgroup
*root_memcg
, bool sync
)
2441 /* Notify other cpus that system-wide "drain" is running */
2444 for_each_online_cpu(cpu
) {
2445 struct memcg_stock_pcp
*stock
= &per_cpu(memcg_stock
, cpu
);
2446 struct mem_cgroup
*memcg
;
2448 memcg
= stock
->cached
;
2449 if (!memcg
|| !stock
->nr_pages
)
2451 if (!mem_cgroup_same_or_subtree(root_memcg
, memcg
))
2453 if (!test_and_set_bit(FLUSHING_CACHED_CHARGE
, &stock
->flags
)) {
2455 drain_local_stock(&stock
->work
);
2457 schedule_work_on(cpu
, &stock
->work
);
2465 for_each_online_cpu(cpu
) {
2466 struct memcg_stock_pcp
*stock
= &per_cpu(memcg_stock
, cpu
);
2467 if (test_bit(FLUSHING_CACHED_CHARGE
, &stock
->flags
))
2468 flush_work(&stock
->work
);
2475 * Tries to drain stocked charges in other cpus. This function is asynchronous
2476 * and just put a work per cpu for draining localy on each cpu. Caller can
2477 * expects some charges will be back to res_counter later but cannot wait for
2480 static void drain_all_stock_async(struct mem_cgroup
*root_memcg
)
2483 * If someone calls draining, avoid adding more kworker runs.
2485 if (!mutex_trylock(&percpu_charge_mutex
))
2487 drain_all_stock(root_memcg
, false);
2488 mutex_unlock(&percpu_charge_mutex
);
2491 /* This is a synchronous drain interface. */
2492 static void drain_all_stock_sync(struct mem_cgroup
*root_memcg
)
2494 /* called when force_empty is called */
2495 mutex_lock(&percpu_charge_mutex
);
2496 drain_all_stock(root_memcg
, true);
2497 mutex_unlock(&percpu_charge_mutex
);
2501 * This function drains percpu counter value from DEAD cpu and
2502 * move it to local cpu. Note that this function can be preempted.
2504 static void mem_cgroup_drain_pcp_counter(struct mem_cgroup
*memcg
, int cpu
)
2508 spin_lock(&memcg
->pcp_counter_lock
);
2509 for (i
= 0; i
< MEM_CGROUP_STAT_NSTATS
; i
++) {
2510 long x
= per_cpu(memcg
->stat
->count
[i
], cpu
);
2512 per_cpu(memcg
->stat
->count
[i
], cpu
) = 0;
2513 memcg
->nocpu_base
.count
[i
] += x
;
2515 for (i
= 0; i
< MEM_CGROUP_EVENTS_NSTATS
; i
++) {
2516 unsigned long x
= per_cpu(memcg
->stat
->events
[i
], cpu
);
2518 per_cpu(memcg
->stat
->events
[i
], cpu
) = 0;
2519 memcg
->nocpu_base
.events
[i
] += x
;
2521 spin_unlock(&memcg
->pcp_counter_lock
);
2524 static int __cpuinit
memcg_cpu_hotplug_callback(struct notifier_block
*nb
,
2525 unsigned long action
,
2528 int cpu
= (unsigned long)hcpu
;
2529 struct memcg_stock_pcp
*stock
;
2530 struct mem_cgroup
*iter
;
2532 if (action
== CPU_ONLINE
)
2535 if (action
!= CPU_DEAD
&& action
!= CPU_DEAD_FROZEN
)
2538 for_each_mem_cgroup(iter
)
2539 mem_cgroup_drain_pcp_counter(iter
, cpu
);
2541 stock
= &per_cpu(memcg_stock
, cpu
);
2547 /* See __mem_cgroup_try_charge() for details */
2549 CHARGE_OK
, /* success */
2550 CHARGE_RETRY
, /* need to retry but retry is not bad */
2551 CHARGE_NOMEM
, /* we can't do more. return -ENOMEM */
2552 CHARGE_WOULDBLOCK
, /* GFP_WAIT wasn't set and no enough res. */
2553 CHARGE_OOM_DIE
, /* the current is killed because of OOM */
2556 static int mem_cgroup_do_charge(struct mem_cgroup
*memcg
, gfp_t gfp_mask
,
2557 unsigned int nr_pages
, unsigned int min_pages
,
2560 unsigned long csize
= nr_pages
* PAGE_SIZE
;
2561 struct mem_cgroup
*mem_over_limit
;
2562 struct res_counter
*fail_res
;
2563 unsigned long flags
= 0;
2566 ret
= res_counter_charge(&memcg
->res
, csize
, &fail_res
);
2569 if (!do_swap_account
)
2571 ret
= res_counter_charge(&memcg
->memsw
, csize
, &fail_res
);
2575 res_counter_uncharge(&memcg
->res
, csize
);
2576 mem_over_limit
= mem_cgroup_from_res_counter(fail_res
, memsw
);
2577 flags
|= MEM_CGROUP_RECLAIM_NOSWAP
;
2579 mem_over_limit
= mem_cgroup_from_res_counter(fail_res
, res
);
2581 * Never reclaim on behalf of optional batching, retry with a
2582 * single page instead.
2584 if (nr_pages
> min_pages
)
2585 return CHARGE_RETRY
;
2587 if (!(gfp_mask
& __GFP_WAIT
))
2588 return CHARGE_WOULDBLOCK
;
2590 if (gfp_mask
& __GFP_NORETRY
)
2591 return CHARGE_NOMEM
;
2593 ret
= mem_cgroup_reclaim(mem_over_limit
, gfp_mask
, flags
);
2594 if (mem_cgroup_margin(mem_over_limit
) >= nr_pages
)
2595 return CHARGE_RETRY
;
2597 * Even though the limit is exceeded at this point, reclaim
2598 * may have been able to free some pages. Retry the charge
2599 * before killing the task.
2601 * Only for regular pages, though: huge pages are rather
2602 * unlikely to succeed so close to the limit, and we fall back
2603 * to regular pages anyway in case of failure.
2605 if (nr_pages
<= (1 << PAGE_ALLOC_COSTLY_ORDER
) && ret
)
2606 return CHARGE_RETRY
;
2609 * At task move, charge accounts can be doubly counted. So, it's
2610 * better to wait until the end of task_move if something is going on.
2612 if (mem_cgroup_wait_acct_move(mem_over_limit
))
2613 return CHARGE_RETRY
;
2615 /* If we don't need to call oom-killer at el, return immediately */
2617 return CHARGE_NOMEM
;
2619 if (!mem_cgroup_handle_oom(mem_over_limit
, gfp_mask
, get_order(csize
)))
2620 return CHARGE_OOM_DIE
;
2622 return CHARGE_RETRY
;
2626 * __mem_cgroup_try_charge() does
2627 * 1. detect memcg to be charged against from passed *mm and *ptr,
2628 * 2. update res_counter
2629 * 3. call memory reclaim if necessary.
2631 * In some special case, if the task is fatal, fatal_signal_pending() or
2632 * has TIF_MEMDIE, this function returns -EINTR while writing root_mem_cgroup
2633 * to *ptr. There are two reasons for this. 1: fatal threads should quit as soon
2634 * as possible without any hazards. 2: all pages should have a valid
2635 * pc->mem_cgroup. If mm is NULL and the caller doesn't pass a valid memcg
2636 * pointer, that is treated as a charge to root_mem_cgroup.
2638 * So __mem_cgroup_try_charge() will return
2639 * 0 ... on success, filling *ptr with a valid memcg pointer.
2640 * -ENOMEM ... charge failure because of resource limits.
2641 * -EINTR ... if thread is fatal. *ptr is filled with root_mem_cgroup.
2643 * Unlike the exported interface, an "oom" parameter is added. if oom==true,
2644 * the oom-killer can be invoked.
2646 static int __mem_cgroup_try_charge(struct mm_struct
*mm
,
2648 unsigned int nr_pages
,
2649 struct mem_cgroup
**ptr
,
2652 unsigned int batch
= max(CHARGE_BATCH
, nr_pages
);
2653 int nr_oom_retries
= MEM_CGROUP_RECLAIM_RETRIES
;
2654 struct mem_cgroup
*memcg
= NULL
;
2658 * Unlike gloval-vm's OOM-kill, we're not in memory shortage
2659 * in system level. So, allow to go ahead dying process in addition to
2662 if (unlikely(test_thread_flag(TIF_MEMDIE
)
2663 || fatal_signal_pending(current
)))
2667 * We always charge the cgroup the mm_struct belongs to.
2668 * The mm_struct's mem_cgroup changes on task migration if the
2669 * thread group leader migrates. It's possible that mm is not
2670 * set, if so charge the root memcg (happens for pagecache usage).
2673 *ptr
= root_mem_cgroup
;
2675 if (*ptr
) { /* css should be a valid one */
2677 if (mem_cgroup_is_root(memcg
))
2679 if (consume_stock(memcg
, nr_pages
))
2681 css_get(&memcg
->css
);
2683 struct task_struct
*p
;
2686 p
= rcu_dereference(mm
->owner
);
2688 * Because we don't have task_lock(), "p" can exit.
2689 * In that case, "memcg" can point to root or p can be NULL with
2690 * race with swapoff. Then, we have small risk of mis-accouning.
2691 * But such kind of mis-account by race always happens because
2692 * we don't have cgroup_mutex(). It's overkill and we allo that
2694 * (*) swapoff at el will charge against mm-struct not against
2695 * task-struct. So, mm->owner can be NULL.
2697 memcg
= mem_cgroup_from_task(p
);
2699 memcg
= root_mem_cgroup
;
2700 if (mem_cgroup_is_root(memcg
)) {
2704 if (consume_stock(memcg
, nr_pages
)) {
2706 * It seems dagerous to access memcg without css_get().
2707 * But considering how consume_stok works, it's not
2708 * necessary. If consume_stock success, some charges
2709 * from this memcg are cached on this cpu. So, we
2710 * don't need to call css_get()/css_tryget() before
2711 * calling consume_stock().
2716 /* after here, we may be blocked. we need to get refcnt */
2717 if (!css_tryget(&memcg
->css
)) {
2727 /* If killed, bypass charge */
2728 if (fatal_signal_pending(current
)) {
2729 css_put(&memcg
->css
);
2734 if (oom
&& !nr_oom_retries
) {
2736 nr_oom_retries
= MEM_CGROUP_RECLAIM_RETRIES
;
2739 ret
= mem_cgroup_do_charge(memcg
, gfp_mask
, batch
, nr_pages
,
2744 case CHARGE_RETRY
: /* not in OOM situation but retry */
2746 css_put(&memcg
->css
);
2749 case CHARGE_WOULDBLOCK
: /* !__GFP_WAIT */
2750 css_put(&memcg
->css
);
2752 case CHARGE_NOMEM
: /* OOM routine works */
2754 css_put(&memcg
->css
);
2757 /* If oom, we never return -ENOMEM */
2760 case CHARGE_OOM_DIE
: /* Killed by OOM Killer */
2761 css_put(&memcg
->css
);
2764 } while (ret
!= CHARGE_OK
);
2766 if (batch
> nr_pages
)
2767 refill_stock(memcg
, batch
- nr_pages
);
2768 css_put(&memcg
->css
);
2776 *ptr
= root_mem_cgroup
;
2781 * Somemtimes we have to undo a charge we got by try_charge().
2782 * This function is for that and do uncharge, put css's refcnt.
2783 * gotten by try_charge().
2785 static void __mem_cgroup_cancel_charge(struct mem_cgroup
*memcg
,
2786 unsigned int nr_pages
)
2788 if (!mem_cgroup_is_root(memcg
)) {
2789 unsigned long bytes
= nr_pages
* PAGE_SIZE
;
2791 res_counter_uncharge(&memcg
->res
, bytes
);
2792 if (do_swap_account
)
2793 res_counter_uncharge(&memcg
->memsw
, bytes
);
2798 * Cancel chrages in this cgroup....doesn't propagate to parent cgroup.
2799 * This is useful when moving usage to parent cgroup.
2801 static void __mem_cgroup_cancel_local_charge(struct mem_cgroup
*memcg
,
2802 unsigned int nr_pages
)
2804 unsigned long bytes
= nr_pages
* PAGE_SIZE
;
2806 if (mem_cgroup_is_root(memcg
))
2809 res_counter_uncharge_until(&memcg
->res
, memcg
->res
.parent
, bytes
);
2810 if (do_swap_account
)
2811 res_counter_uncharge_until(&memcg
->memsw
,
2812 memcg
->memsw
.parent
, bytes
);
2816 * A helper function to get mem_cgroup from ID. must be called under
2817 * rcu_read_lock(). The caller is responsible for calling css_tryget if
2818 * the mem_cgroup is used for charging. (dropping refcnt from swap can be
2819 * called against removed memcg.)
2821 static struct mem_cgroup
*mem_cgroup_lookup(unsigned short id
)
2823 struct cgroup_subsys_state
*css
;
2825 /* ID 0 is unused ID */
2828 css
= css_lookup(&mem_cgroup_subsys
, id
);
2831 return mem_cgroup_from_css(css
);
2834 struct mem_cgroup
*try_get_mem_cgroup_from_page(struct page
*page
)
2836 struct mem_cgroup
*memcg
= NULL
;
2837 struct page_cgroup
*pc
;
2841 VM_BUG_ON(!PageLocked(page
));
2843 pc
= lookup_page_cgroup(page
);
2844 lock_page_cgroup(pc
);
2845 if (PageCgroupUsed(pc
)) {
2846 memcg
= pc
->mem_cgroup
;
2847 if (memcg
&& !css_tryget(&memcg
->css
))
2849 } else if (PageSwapCache(page
)) {
2850 ent
.val
= page_private(page
);
2851 id
= lookup_swap_cgroup_id(ent
);
2853 memcg
= mem_cgroup_lookup(id
);
2854 if (memcg
&& !css_tryget(&memcg
->css
))
2858 unlock_page_cgroup(pc
);
2862 static void __mem_cgroup_commit_charge(struct mem_cgroup
*memcg
,
2864 unsigned int nr_pages
,
2865 enum charge_type ctype
,
2868 struct page_cgroup
*pc
= lookup_page_cgroup(page
);
2869 struct zone
*uninitialized_var(zone
);
2870 struct lruvec
*lruvec
;
2871 bool was_on_lru
= false;
2874 lock_page_cgroup(pc
);
2875 VM_BUG_ON(PageCgroupUsed(pc
));
2877 * we don't need page_cgroup_lock about tail pages, becase they are not
2878 * accessed by any other context at this point.
2882 * In some cases, SwapCache and FUSE(splice_buf->radixtree), the page
2883 * may already be on some other mem_cgroup's LRU. Take care of it.
2886 zone
= page_zone(page
);
2887 spin_lock_irq(&zone
->lru_lock
);
2888 if (PageLRU(page
)) {
2889 lruvec
= mem_cgroup_zone_lruvec(zone
, pc
->mem_cgroup
);
2891 del_page_from_lru_list(page
, lruvec
, page_lru(page
));
2896 pc
->mem_cgroup
= memcg
;
2898 * We access a page_cgroup asynchronously without lock_page_cgroup().
2899 * Especially when a page_cgroup is taken from a page, pc->mem_cgroup
2900 * is accessed after testing USED bit. To make pc->mem_cgroup visible
2901 * before USED bit, we need memory barrier here.
2902 * See mem_cgroup_add_lru_list(), etc.
2905 SetPageCgroupUsed(pc
);
2909 lruvec
= mem_cgroup_zone_lruvec(zone
, pc
->mem_cgroup
);
2910 VM_BUG_ON(PageLRU(page
));
2912 add_page_to_lru_list(page
, lruvec
, page_lru(page
));
2914 spin_unlock_irq(&zone
->lru_lock
);
2917 if (ctype
== MEM_CGROUP_CHARGE_TYPE_ANON
)
2922 mem_cgroup_charge_statistics(memcg
, page
, anon
, nr_pages
);
2923 unlock_page_cgroup(pc
);
2926 * "charge_statistics" updated event counter. Then, check it.
2927 * Insert ancestor (and ancestor's ancestors), to softlimit RB-tree.
2928 * if they exceeds softlimit.
2930 memcg_check_events(memcg
, page
);
2933 static DEFINE_MUTEX(set_limit_mutex
);
2935 #ifdef CONFIG_MEMCG_KMEM
2936 static inline bool memcg_can_account_kmem(struct mem_cgroup
*memcg
)
2938 return !mem_cgroup_disabled() && !mem_cgroup_is_root(memcg
) &&
2939 (memcg
->kmem_account_flags
& KMEM_ACCOUNTED_MASK
);
2943 * This is a bit cumbersome, but it is rarely used and avoids a backpointer
2944 * in the memcg_cache_params struct.
2946 static struct kmem_cache
*memcg_params_to_cache(struct memcg_cache_params
*p
)
2948 struct kmem_cache
*cachep
;
2950 VM_BUG_ON(p
->is_root_cache
);
2951 cachep
= p
->root_cache
;
2952 return cachep
->memcg_params
->memcg_caches
[memcg_cache_id(p
->memcg
)];
2955 #ifdef CONFIG_SLABINFO
2956 static int mem_cgroup_slabinfo_read(struct cgroup
*cont
, struct cftype
*cft
,
2959 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cont
);
2960 struct memcg_cache_params
*params
;
2962 if (!memcg_can_account_kmem(memcg
))
2965 print_slabinfo_header(m
);
2967 mutex_lock(&memcg
->slab_caches_mutex
);
2968 list_for_each_entry(params
, &memcg
->memcg_slab_caches
, list
)
2969 cache_show(memcg_params_to_cache(params
), m
);
2970 mutex_unlock(&memcg
->slab_caches_mutex
);
2976 static int memcg_charge_kmem(struct mem_cgroup
*memcg
, gfp_t gfp
, u64 size
)
2978 struct res_counter
*fail_res
;
2979 struct mem_cgroup
*_memcg
;
2983 ret
= res_counter_charge(&memcg
->kmem
, size
, &fail_res
);
2988 * Conditions under which we can wait for the oom_killer. Those are
2989 * the same conditions tested by the core page allocator
2991 may_oom
= (gfp
& __GFP_FS
) && !(gfp
& __GFP_NORETRY
);
2994 ret
= __mem_cgroup_try_charge(NULL
, gfp
, size
>> PAGE_SHIFT
,
2997 if (ret
== -EINTR
) {
2999 * __mem_cgroup_try_charge() chosed to bypass to root due to
3000 * OOM kill or fatal signal. Since our only options are to
3001 * either fail the allocation or charge it to this cgroup, do
3002 * it as a temporary condition. But we can't fail. From a
3003 * kmem/slab perspective, the cache has already been selected,
3004 * by mem_cgroup_kmem_get_cache(), so it is too late to change
3007 * This condition will only trigger if the task entered
3008 * memcg_charge_kmem in a sane state, but was OOM-killed during
3009 * __mem_cgroup_try_charge() above. Tasks that were already
3010 * dying when the allocation triggers should have been already
3011 * directed to the root cgroup in memcontrol.h
3013 res_counter_charge_nofail(&memcg
->res
, size
, &fail_res
);
3014 if (do_swap_account
)
3015 res_counter_charge_nofail(&memcg
->memsw
, size
,
3019 res_counter_uncharge(&memcg
->kmem
, size
);
3024 static void memcg_uncharge_kmem(struct mem_cgroup
*memcg
, u64 size
)
3026 res_counter_uncharge(&memcg
->res
, size
);
3027 if (do_swap_account
)
3028 res_counter_uncharge(&memcg
->memsw
, size
);
3031 if (res_counter_uncharge(&memcg
->kmem
, size
))
3035 * Releases a reference taken in kmem_cgroup_css_offline in case
3036 * this last uncharge is racing with the offlining code or it is
3037 * outliving the memcg existence.
3039 * The memory barrier imposed by test&clear is paired with the
3040 * explicit one in memcg_kmem_mark_dead().
3042 if (memcg_kmem_test_and_clear_dead(memcg
))
3043 css_put(&memcg
->css
);
3046 void memcg_cache_list_add(struct mem_cgroup
*memcg
, struct kmem_cache
*cachep
)
3051 mutex_lock(&memcg
->slab_caches_mutex
);
3052 list_add(&cachep
->memcg_params
->list
, &memcg
->memcg_slab_caches
);
3053 mutex_unlock(&memcg
->slab_caches_mutex
);
3057 * helper for acessing a memcg's index. It will be used as an index in the
3058 * child cache array in kmem_cache, and also to derive its name. This function
3059 * will return -1 when this is not a kmem-limited memcg.
3061 int memcg_cache_id(struct mem_cgroup
*memcg
)
3063 return memcg
? memcg
->kmemcg_id
: -1;
3067 * This ends up being protected by the set_limit mutex, during normal
3068 * operation, because that is its main call site.
3070 * But when we create a new cache, we can call this as well if its parent
3071 * is kmem-limited. That will have to hold set_limit_mutex as well.
3073 int memcg_update_cache_sizes(struct mem_cgroup
*memcg
)
3077 num
= ida_simple_get(&kmem_limited_groups
,
3078 0, MEMCG_CACHES_MAX_SIZE
, GFP_KERNEL
);
3082 * After this point, kmem_accounted (that we test atomically in
3083 * the beginning of this conditional), is no longer 0. This
3084 * guarantees only one process will set the following boolean
3085 * to true. We don't need test_and_set because we're protected
3086 * by the set_limit_mutex anyway.
3088 memcg_kmem_set_activated(memcg
);
3090 ret
= memcg_update_all_caches(num
+1);
3092 ida_simple_remove(&kmem_limited_groups
, num
);
3093 memcg_kmem_clear_activated(memcg
);
3097 memcg
->kmemcg_id
= num
;
3098 INIT_LIST_HEAD(&memcg
->memcg_slab_caches
);
3099 mutex_init(&memcg
->slab_caches_mutex
);
3103 static size_t memcg_caches_array_size(int num_groups
)
3106 if (num_groups
<= 0)
3109 size
= 2 * num_groups
;
3110 if (size
< MEMCG_CACHES_MIN_SIZE
)
3111 size
= MEMCG_CACHES_MIN_SIZE
;
3112 else if (size
> MEMCG_CACHES_MAX_SIZE
)
3113 size
= MEMCG_CACHES_MAX_SIZE
;
3119 * We should update the current array size iff all caches updates succeed. This
3120 * can only be done from the slab side. The slab mutex needs to be held when
3123 void memcg_update_array_size(int num
)
3125 if (num
> memcg_limited_groups_array_size
)
3126 memcg_limited_groups_array_size
= memcg_caches_array_size(num
);
3129 static void kmem_cache_destroy_work_func(struct work_struct
*w
);
3131 int memcg_update_cache_size(struct kmem_cache
*s
, int num_groups
)
3133 struct memcg_cache_params
*cur_params
= s
->memcg_params
;
3135 VM_BUG_ON(s
->memcg_params
&& !s
->memcg_params
->is_root_cache
);
3137 if (num_groups
> memcg_limited_groups_array_size
) {
3139 ssize_t size
= memcg_caches_array_size(num_groups
);
3141 size
*= sizeof(void *);
3142 size
+= sizeof(struct memcg_cache_params
);
3144 s
->memcg_params
= kzalloc(size
, GFP_KERNEL
);
3145 if (!s
->memcg_params
) {
3146 s
->memcg_params
= cur_params
;
3150 s
->memcg_params
->is_root_cache
= true;
3153 * There is the chance it will be bigger than
3154 * memcg_limited_groups_array_size, if we failed an allocation
3155 * in a cache, in which case all caches updated before it, will
3156 * have a bigger array.
3158 * But if that is the case, the data after
3159 * memcg_limited_groups_array_size is certainly unused
3161 for (i
= 0; i
< memcg_limited_groups_array_size
; i
++) {
3162 if (!cur_params
->memcg_caches
[i
])
3164 s
->memcg_params
->memcg_caches
[i
] =
3165 cur_params
->memcg_caches
[i
];
3169 * Ideally, we would wait until all caches succeed, and only
3170 * then free the old one. But this is not worth the extra
3171 * pointer per-cache we'd have to have for this.
3173 * It is not a big deal if some caches are left with a size
3174 * bigger than the others. And all updates will reset this
3182 int memcg_register_cache(struct mem_cgroup
*memcg
, struct kmem_cache
*s
,
3183 struct kmem_cache
*root_cache
)
3185 size_t size
= sizeof(struct memcg_cache_params
);
3187 if (!memcg_kmem_enabled())
3191 size
+= memcg_limited_groups_array_size
* sizeof(void *);
3193 s
->memcg_params
= kzalloc(size
, GFP_KERNEL
);
3194 if (!s
->memcg_params
)
3197 INIT_WORK(&s
->memcg_params
->destroy
,
3198 kmem_cache_destroy_work_func
);
3200 s
->memcg_params
->memcg
= memcg
;
3201 s
->memcg_params
->root_cache
= root_cache
;
3203 s
->memcg_params
->is_root_cache
= true;
3208 void memcg_release_cache(struct kmem_cache
*s
)
3210 struct kmem_cache
*root
;
3211 struct mem_cgroup
*memcg
;
3215 * This happens, for instance, when a root cache goes away before we
3218 if (!s
->memcg_params
)
3221 if (s
->memcg_params
->is_root_cache
)
3224 memcg
= s
->memcg_params
->memcg
;
3225 id
= memcg_cache_id(memcg
);
3227 root
= s
->memcg_params
->root_cache
;
3228 root
->memcg_params
->memcg_caches
[id
] = NULL
;
3230 mutex_lock(&memcg
->slab_caches_mutex
);
3231 list_del(&s
->memcg_params
->list
);
3232 mutex_unlock(&memcg
->slab_caches_mutex
);
3234 css_put(&memcg
->css
);
3236 kfree(s
->memcg_params
);
3240 * During the creation a new cache, we need to disable our accounting mechanism
3241 * altogether. This is true even if we are not creating, but rather just
3242 * enqueing new caches to be created.
3244 * This is because that process will trigger allocations; some visible, like
3245 * explicit kmallocs to auxiliary data structures, name strings and internal
3246 * cache structures; some well concealed, like INIT_WORK() that can allocate
3247 * objects during debug.
3249 * If any allocation happens during memcg_kmem_get_cache, we will recurse back
3250 * to it. This may not be a bounded recursion: since the first cache creation
3251 * failed to complete (waiting on the allocation), we'll just try to create the
3252 * cache again, failing at the same point.
3254 * memcg_kmem_get_cache is prepared to abort after seeing a positive count of
3255 * memcg_kmem_skip_account. So we enclose anything that might allocate memory
3256 * inside the following two functions.
3258 static inline void memcg_stop_kmem_account(void)
3260 VM_BUG_ON(!current
->mm
);
3261 current
->memcg_kmem_skip_account
++;
3264 static inline void memcg_resume_kmem_account(void)
3266 VM_BUG_ON(!current
->mm
);
3267 current
->memcg_kmem_skip_account
--;
3270 static void kmem_cache_destroy_work_func(struct work_struct
*w
)
3272 struct kmem_cache
*cachep
;
3273 struct memcg_cache_params
*p
;
3275 p
= container_of(w
, struct memcg_cache_params
, destroy
);
3277 cachep
= memcg_params_to_cache(p
);
3280 * If we get down to 0 after shrink, we could delete right away.
3281 * However, memcg_release_pages() already puts us back in the workqueue
3282 * in that case. If we proceed deleting, we'll get a dangling
3283 * reference, and removing the object from the workqueue in that case
3284 * is unnecessary complication. We are not a fast path.
3286 * Note that this case is fundamentally different from racing with
3287 * shrink_slab(): if memcg_cgroup_destroy_cache() is called in
3288 * kmem_cache_shrink, not only we would be reinserting a dead cache
3289 * into the queue, but doing so from inside the worker racing to
3292 * So if we aren't down to zero, we'll just schedule a worker and try
3295 if (atomic_read(&cachep
->memcg_params
->nr_pages
) != 0) {
3296 kmem_cache_shrink(cachep
);
3297 if (atomic_read(&cachep
->memcg_params
->nr_pages
) == 0)
3300 kmem_cache_destroy(cachep
);
3303 void mem_cgroup_destroy_cache(struct kmem_cache
*cachep
)
3305 if (!cachep
->memcg_params
->dead
)
3309 * There are many ways in which we can get here.
3311 * We can get to a memory-pressure situation while the delayed work is
3312 * still pending to run. The vmscan shrinkers can then release all
3313 * cache memory and get us to destruction. If this is the case, we'll
3314 * be executed twice, which is a bug (the second time will execute over
3315 * bogus data). In this case, cancelling the work should be fine.
3317 * But we can also get here from the worker itself, if
3318 * kmem_cache_shrink is enough to shake all the remaining objects and
3319 * get the page count to 0. In this case, we'll deadlock if we try to
3320 * cancel the work (the worker runs with an internal lock held, which
3321 * is the same lock we would hold for cancel_work_sync().)
3323 * Since we can't possibly know who got us here, just refrain from
3324 * running if there is already work pending
3326 if (work_pending(&cachep
->memcg_params
->destroy
))
3329 * We have to defer the actual destroying to a workqueue, because
3330 * we might currently be in a context that cannot sleep.
3332 schedule_work(&cachep
->memcg_params
->destroy
);
3336 * This lock protects updaters, not readers. We want readers to be as fast as
3337 * they can, and they will either see NULL or a valid cache value. Our model
3338 * allow them to see NULL, in which case the root memcg will be selected.
3340 * We need this lock because multiple allocations to the same cache from a non
3341 * will span more than one worker. Only one of them can create the cache.
3343 static DEFINE_MUTEX(memcg_cache_mutex
);
3346 * Called with memcg_cache_mutex held
3348 static struct kmem_cache
*kmem_cache_dup(struct mem_cgroup
*memcg
,
3349 struct kmem_cache
*s
)
3351 struct kmem_cache
*new;
3352 static char *tmp_name
= NULL
;
3354 lockdep_assert_held(&memcg_cache_mutex
);
3357 * kmem_cache_create_memcg duplicates the given name and
3358 * cgroup_name for this name requires RCU context.
3359 * This static temporary buffer is used to prevent from
3360 * pointless shortliving allocation.
3363 tmp_name
= kmalloc(PATH_MAX
, GFP_KERNEL
);
3369 snprintf(tmp_name
, PATH_MAX
, "%s(%d:%s)", s
->name
,
3370 memcg_cache_id(memcg
), cgroup_name(memcg
->css
.cgroup
));
3373 new = kmem_cache_create_memcg(memcg
, tmp_name
, s
->object_size
, s
->align
,
3374 (s
->flags
& ~SLAB_PANIC
), s
->ctor
, s
);
3377 new->allocflags
|= __GFP_KMEMCG
;
3382 static struct kmem_cache
*memcg_create_kmem_cache(struct mem_cgroup
*memcg
,
3383 struct kmem_cache
*cachep
)
3385 struct kmem_cache
*new_cachep
;
3388 BUG_ON(!memcg_can_account_kmem(memcg
));
3390 idx
= memcg_cache_id(memcg
);
3392 mutex_lock(&memcg_cache_mutex
);
3393 new_cachep
= cachep
->memcg_params
->memcg_caches
[idx
];
3395 css_put(&memcg
->css
);
3399 new_cachep
= kmem_cache_dup(memcg
, cachep
);
3400 if (new_cachep
== NULL
) {
3401 new_cachep
= cachep
;
3402 css_put(&memcg
->css
);
3406 atomic_set(&new_cachep
->memcg_params
->nr_pages
, 0);
3408 cachep
->memcg_params
->memcg_caches
[idx
] = new_cachep
;
3410 * the readers won't lock, make sure everybody sees the updated value,
3411 * so they won't put stuff in the queue again for no reason
3415 mutex_unlock(&memcg_cache_mutex
);
3419 void kmem_cache_destroy_memcg_children(struct kmem_cache
*s
)
3421 struct kmem_cache
*c
;
3424 if (!s
->memcg_params
)
3426 if (!s
->memcg_params
->is_root_cache
)
3430 * If the cache is being destroyed, we trust that there is no one else
3431 * requesting objects from it. Even if there are, the sanity checks in
3432 * kmem_cache_destroy should caught this ill-case.
3434 * Still, we don't want anyone else freeing memcg_caches under our
3435 * noses, which can happen if a new memcg comes to life. As usual,
3436 * we'll take the set_limit_mutex to protect ourselves against this.
3438 mutex_lock(&set_limit_mutex
);
3439 for (i
= 0; i
< memcg_limited_groups_array_size
; i
++) {
3440 c
= s
->memcg_params
->memcg_caches
[i
];
3445 * We will now manually delete the caches, so to avoid races
3446 * we need to cancel all pending destruction workers and
3447 * proceed with destruction ourselves.
3449 * kmem_cache_destroy() will call kmem_cache_shrink internally,
3450 * and that could spawn the workers again: it is likely that
3451 * the cache still have active pages until this very moment.
3452 * This would lead us back to mem_cgroup_destroy_cache.
3454 * But that will not execute at all if the "dead" flag is not
3455 * set, so flip it down to guarantee we are in control.
3457 c
->memcg_params
->dead
= false;
3458 cancel_work_sync(&c
->memcg_params
->destroy
);
3459 kmem_cache_destroy(c
);
3461 mutex_unlock(&set_limit_mutex
);
3464 struct create_work
{
3465 struct mem_cgroup
*memcg
;
3466 struct kmem_cache
*cachep
;
3467 struct work_struct work
;
3470 static void mem_cgroup_destroy_all_caches(struct mem_cgroup
*memcg
)
3472 struct kmem_cache
*cachep
;
3473 struct memcg_cache_params
*params
;
3475 if (!memcg_kmem_is_active(memcg
))
3478 mutex_lock(&memcg
->slab_caches_mutex
);
3479 list_for_each_entry(params
, &memcg
->memcg_slab_caches
, list
) {
3480 cachep
= memcg_params_to_cache(params
);
3481 cachep
->memcg_params
->dead
= true;
3482 schedule_work(&cachep
->memcg_params
->destroy
);
3484 mutex_unlock(&memcg
->slab_caches_mutex
);
3487 static void memcg_create_cache_work_func(struct work_struct
*w
)
3489 struct create_work
*cw
;
3491 cw
= container_of(w
, struct create_work
, work
);
3492 memcg_create_kmem_cache(cw
->memcg
, cw
->cachep
);
3497 * Enqueue the creation of a per-memcg kmem_cache.
3499 static void __memcg_create_cache_enqueue(struct mem_cgroup
*memcg
,
3500 struct kmem_cache
*cachep
)
3502 struct create_work
*cw
;
3504 cw
= kmalloc(sizeof(struct create_work
), GFP_NOWAIT
);
3506 css_put(&memcg
->css
);
3511 cw
->cachep
= cachep
;
3513 INIT_WORK(&cw
->work
, memcg_create_cache_work_func
);
3514 schedule_work(&cw
->work
);
3517 static void memcg_create_cache_enqueue(struct mem_cgroup
*memcg
,
3518 struct kmem_cache
*cachep
)
3521 * We need to stop accounting when we kmalloc, because if the
3522 * corresponding kmalloc cache is not yet created, the first allocation
3523 * in __memcg_create_cache_enqueue will recurse.
3525 * However, it is better to enclose the whole function. Depending on
3526 * the debugging options enabled, INIT_WORK(), for instance, can
3527 * trigger an allocation. This too, will make us recurse. Because at
3528 * this point we can't allow ourselves back into memcg_kmem_get_cache,
3529 * the safest choice is to do it like this, wrapping the whole function.
3531 memcg_stop_kmem_account();
3532 __memcg_create_cache_enqueue(memcg
, cachep
);
3533 memcg_resume_kmem_account();
3536 * Return the kmem_cache we're supposed to use for a slab allocation.
3537 * We try to use the current memcg's version of the cache.
3539 * If the cache does not exist yet, if we are the first user of it,
3540 * we either create it immediately, if possible, or create it asynchronously
3542 * In the latter case, we will let the current allocation go through with
3543 * the original cache.
3545 * Can't be called in interrupt context or from kernel threads.
3546 * This function needs to be called with rcu_read_lock() held.
3548 struct kmem_cache
*__memcg_kmem_get_cache(struct kmem_cache
*cachep
,
3551 struct mem_cgroup
*memcg
;
3554 VM_BUG_ON(!cachep
->memcg_params
);
3555 VM_BUG_ON(!cachep
->memcg_params
->is_root_cache
);
3557 if (!current
->mm
|| current
->memcg_kmem_skip_account
)
3561 memcg
= mem_cgroup_from_task(rcu_dereference(current
->mm
->owner
));
3563 if (!memcg_can_account_kmem(memcg
))
3566 idx
= memcg_cache_id(memcg
);
3569 * barrier to mare sure we're always seeing the up to date value. The
3570 * code updating memcg_caches will issue a write barrier to match this.
3572 read_barrier_depends();
3573 if (likely(cachep
->memcg_params
->memcg_caches
[idx
])) {
3574 cachep
= cachep
->memcg_params
->memcg_caches
[idx
];
3578 /* The corresponding put will be done in the workqueue. */
3579 if (!css_tryget(&memcg
->css
))
3584 * If we are in a safe context (can wait, and not in interrupt
3585 * context), we could be be predictable and return right away.
3586 * This would guarantee that the allocation being performed
3587 * already belongs in the new cache.
3589 * However, there are some clashes that can arrive from locking.
3590 * For instance, because we acquire the slab_mutex while doing
3591 * kmem_cache_dup, this means no further allocation could happen
3592 * with the slab_mutex held.
3594 * Also, because cache creation issue get_online_cpus(), this
3595 * creates a lock chain: memcg_slab_mutex -> cpu_hotplug_mutex,
3596 * that ends up reversed during cpu hotplug. (cpuset allocates
3597 * a bunch of GFP_KERNEL memory during cpuup). Due to all that,
3598 * better to defer everything.
3600 memcg_create_cache_enqueue(memcg
, cachep
);
3606 EXPORT_SYMBOL(__memcg_kmem_get_cache
);
3609 * We need to verify if the allocation against current->mm->owner's memcg is
3610 * possible for the given order. But the page is not allocated yet, so we'll
3611 * need a further commit step to do the final arrangements.
3613 * It is possible for the task to switch cgroups in this mean time, so at
3614 * commit time, we can't rely on task conversion any longer. We'll then use
3615 * the handle argument to return to the caller which cgroup we should commit
3616 * against. We could also return the memcg directly and avoid the pointer
3617 * passing, but a boolean return value gives better semantics considering
3618 * the compiled-out case as well.
3620 * Returning true means the allocation is possible.
3623 __memcg_kmem_newpage_charge(gfp_t gfp
, struct mem_cgroup
**_memcg
, int order
)
3625 struct mem_cgroup
*memcg
;
3631 * Disabling accounting is only relevant for some specific memcg
3632 * internal allocations. Therefore we would initially not have such
3633 * check here, since direct calls to the page allocator that are marked
3634 * with GFP_KMEMCG only happen outside memcg core. We are mostly
3635 * concerned with cache allocations, and by having this test at
3636 * memcg_kmem_get_cache, we are already able to relay the allocation to
3637 * the root cache and bypass the memcg cache altogether.
3639 * There is one exception, though: the SLUB allocator does not create
3640 * large order caches, but rather service large kmallocs directly from
3641 * the page allocator. Therefore, the following sequence when backed by
3642 * the SLUB allocator:
3644 * memcg_stop_kmem_account();
3645 * kmalloc(<large_number>)
3646 * memcg_resume_kmem_account();
3648 * would effectively ignore the fact that we should skip accounting,
3649 * since it will drive us directly to this function without passing
3650 * through the cache selector memcg_kmem_get_cache. Such large
3651 * allocations are extremely rare but can happen, for instance, for the
3652 * cache arrays. We bring this test here.
3654 if (!current
->mm
|| current
->memcg_kmem_skip_account
)
3657 memcg
= try_get_mem_cgroup_from_mm(current
->mm
);
3660 * very rare case described in mem_cgroup_from_task. Unfortunately there
3661 * isn't much we can do without complicating this too much, and it would
3662 * be gfp-dependent anyway. Just let it go
3664 if (unlikely(!memcg
))
3667 if (!memcg_can_account_kmem(memcg
)) {
3668 css_put(&memcg
->css
);
3672 ret
= memcg_charge_kmem(memcg
, gfp
, PAGE_SIZE
<< order
);
3676 css_put(&memcg
->css
);
3680 void __memcg_kmem_commit_charge(struct page
*page
, struct mem_cgroup
*memcg
,
3683 struct page_cgroup
*pc
;
3685 VM_BUG_ON(mem_cgroup_is_root(memcg
));
3687 /* The page allocation failed. Revert */
3689 memcg_uncharge_kmem(memcg
, PAGE_SIZE
<< order
);
3693 pc
= lookup_page_cgroup(page
);
3694 lock_page_cgroup(pc
);
3695 pc
->mem_cgroup
= memcg
;
3696 SetPageCgroupUsed(pc
);
3697 unlock_page_cgroup(pc
);
3700 void __memcg_kmem_uncharge_pages(struct page
*page
, int order
)
3702 struct mem_cgroup
*memcg
= NULL
;
3703 struct page_cgroup
*pc
;
3706 pc
= lookup_page_cgroup(page
);
3708 * Fast unlocked return. Theoretically might have changed, have to
3709 * check again after locking.
3711 if (!PageCgroupUsed(pc
))
3714 lock_page_cgroup(pc
);
3715 if (PageCgroupUsed(pc
)) {
3716 memcg
= pc
->mem_cgroup
;
3717 ClearPageCgroupUsed(pc
);
3719 unlock_page_cgroup(pc
);
3722 * We trust that only if there is a memcg associated with the page, it
3723 * is a valid allocation
3728 VM_BUG_ON(mem_cgroup_is_root(memcg
));
3729 memcg_uncharge_kmem(memcg
, PAGE_SIZE
<< order
);
3732 static inline void mem_cgroup_destroy_all_caches(struct mem_cgroup
*memcg
)
3735 #endif /* CONFIG_MEMCG_KMEM */
3737 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
3739 #define PCGF_NOCOPY_AT_SPLIT (1 << PCG_LOCK | 1 << PCG_MIGRATION)
3741 * Because tail pages are not marked as "used", set it. We're under
3742 * zone->lru_lock, 'splitting on pmd' and compound_lock.
3743 * charge/uncharge will be never happen and move_account() is done under
3744 * compound_lock(), so we don't have to take care of races.
3746 void mem_cgroup_split_huge_fixup(struct page
*head
)
3748 struct page_cgroup
*head_pc
= lookup_page_cgroup(head
);
3749 struct page_cgroup
*pc
;
3750 struct mem_cgroup
*memcg
;
3753 if (mem_cgroup_disabled())
3756 memcg
= head_pc
->mem_cgroup
;
3757 for (i
= 1; i
< HPAGE_PMD_NR
; i
++) {
3759 pc
->mem_cgroup
= memcg
;
3760 smp_wmb();/* see __commit_charge() */
3761 pc
->flags
= head_pc
->flags
& ~PCGF_NOCOPY_AT_SPLIT
;
3763 __this_cpu_sub(memcg
->stat
->count
[MEM_CGROUP_STAT_RSS_HUGE
],
3766 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
3769 * mem_cgroup_move_account - move account of the page
3771 * @nr_pages: number of regular pages (>1 for huge pages)
3772 * @pc: page_cgroup of the page.
3773 * @from: mem_cgroup which the page is moved from.
3774 * @to: mem_cgroup which the page is moved to. @from != @to.
3776 * The caller must confirm following.
3777 * - page is not on LRU (isolate_page() is useful.)
3778 * - compound_lock is held when nr_pages > 1
3780 * This function doesn't do "charge" to new cgroup and doesn't do "uncharge"
3783 static int mem_cgroup_move_account(struct page
*page
,
3784 unsigned int nr_pages
,
3785 struct page_cgroup
*pc
,
3786 struct mem_cgroup
*from
,
3787 struct mem_cgroup
*to
)
3789 unsigned long flags
;
3791 bool anon
= PageAnon(page
);
3793 VM_BUG_ON(from
== to
);
3794 VM_BUG_ON(PageLRU(page
));
3796 * The page is isolated from LRU. So, collapse function
3797 * will not handle this page. But page splitting can happen.
3798 * Do this check under compound_page_lock(). The caller should
3802 if (nr_pages
> 1 && !PageTransHuge(page
))
3805 lock_page_cgroup(pc
);
3808 if (!PageCgroupUsed(pc
) || pc
->mem_cgroup
!= from
)
3811 move_lock_mem_cgroup(from
, &flags
);
3813 if (!anon
&& page_mapped(page
)) {
3814 /* Update mapped_file data for mem_cgroup */
3816 __this_cpu_dec(from
->stat
->count
[MEM_CGROUP_STAT_FILE_MAPPED
]);
3817 __this_cpu_inc(to
->stat
->count
[MEM_CGROUP_STAT_FILE_MAPPED
]);
3820 mem_cgroup_charge_statistics(from
, page
, anon
, -nr_pages
);
3822 /* caller should have done css_get */
3823 pc
->mem_cgroup
= to
;
3824 mem_cgroup_charge_statistics(to
, page
, anon
, nr_pages
);
3825 move_unlock_mem_cgroup(from
, &flags
);
3828 unlock_page_cgroup(pc
);
3832 memcg_check_events(to
, page
);
3833 memcg_check_events(from
, page
);
3839 * mem_cgroup_move_parent - moves page to the parent group
3840 * @page: the page to move
3841 * @pc: page_cgroup of the page
3842 * @child: page's cgroup
3844 * move charges to its parent or the root cgroup if the group has no
3845 * parent (aka use_hierarchy==0).
3846 * Although this might fail (get_page_unless_zero, isolate_lru_page or
3847 * mem_cgroup_move_account fails) the failure is always temporary and
3848 * it signals a race with a page removal/uncharge or migration. In the
3849 * first case the page is on the way out and it will vanish from the LRU
3850 * on the next attempt and the call should be retried later.
3851 * Isolation from the LRU fails only if page has been isolated from
3852 * the LRU since we looked at it and that usually means either global
3853 * reclaim or migration going on. The page will either get back to the
3855 * Finaly mem_cgroup_move_account fails only if the page got uncharged
3856 * (!PageCgroupUsed) or moved to a different group. The page will
3857 * disappear in the next attempt.
3859 static int mem_cgroup_move_parent(struct page
*page
,
3860 struct page_cgroup
*pc
,
3861 struct mem_cgroup
*child
)
3863 struct mem_cgroup
*parent
;
3864 unsigned int nr_pages
;
3865 unsigned long uninitialized_var(flags
);
3868 VM_BUG_ON(mem_cgroup_is_root(child
));
3871 if (!get_page_unless_zero(page
))
3873 if (isolate_lru_page(page
))
3876 nr_pages
= hpage_nr_pages(page
);
3878 parent
= parent_mem_cgroup(child
);
3880 * If no parent, move charges to root cgroup.
3883 parent
= root_mem_cgroup
;
3886 VM_BUG_ON(!PageTransHuge(page
));
3887 flags
= compound_lock_irqsave(page
);
3890 ret
= mem_cgroup_move_account(page
, nr_pages
,
3893 __mem_cgroup_cancel_local_charge(child
, nr_pages
);
3896 compound_unlock_irqrestore(page
, flags
);
3897 putback_lru_page(page
);
3905 * Charge the memory controller for page usage.
3907 * 0 if the charge was successful
3908 * < 0 if the cgroup is over its limit
3910 static int mem_cgroup_charge_common(struct page
*page
, struct mm_struct
*mm
,
3911 gfp_t gfp_mask
, enum charge_type ctype
)
3913 struct mem_cgroup
*memcg
= NULL
;
3914 unsigned int nr_pages
= 1;
3918 if (PageTransHuge(page
)) {
3919 nr_pages
<<= compound_order(page
);
3920 VM_BUG_ON(!PageTransHuge(page
));
3922 * Never OOM-kill a process for a huge page. The
3923 * fault handler will fall back to regular pages.
3928 ret
= __mem_cgroup_try_charge(mm
, gfp_mask
, nr_pages
, &memcg
, oom
);
3931 __mem_cgroup_commit_charge(memcg
, page
, nr_pages
, ctype
, false);
3935 int mem_cgroup_newpage_charge(struct page
*page
,
3936 struct mm_struct
*mm
, gfp_t gfp_mask
)
3938 if (mem_cgroup_disabled())
3940 VM_BUG_ON(page_mapped(page
));
3941 VM_BUG_ON(page
->mapping
&& !PageAnon(page
));
3943 return mem_cgroup_charge_common(page
, mm
, gfp_mask
,
3944 MEM_CGROUP_CHARGE_TYPE_ANON
);
3948 * While swap-in, try_charge -> commit or cancel, the page is locked.
3949 * And when try_charge() successfully returns, one refcnt to memcg without
3950 * struct page_cgroup is acquired. This refcnt will be consumed by
3951 * "commit()" or removed by "cancel()"
3953 static int __mem_cgroup_try_charge_swapin(struct mm_struct
*mm
,
3956 struct mem_cgroup
**memcgp
)
3958 struct mem_cgroup
*memcg
;
3959 struct page_cgroup
*pc
;
3962 pc
= lookup_page_cgroup(page
);
3964 * Every swap fault against a single page tries to charge the
3965 * page, bail as early as possible. shmem_unuse() encounters
3966 * already charged pages, too. The USED bit is protected by
3967 * the page lock, which serializes swap cache removal, which
3968 * in turn serializes uncharging.
3970 if (PageCgroupUsed(pc
))
3972 if (!do_swap_account
)
3974 memcg
= try_get_mem_cgroup_from_page(page
);
3978 ret
= __mem_cgroup_try_charge(NULL
, mask
, 1, memcgp
, true);
3979 css_put(&memcg
->css
);
3984 ret
= __mem_cgroup_try_charge(mm
, mask
, 1, memcgp
, true);
3990 int mem_cgroup_try_charge_swapin(struct mm_struct
*mm
, struct page
*page
,
3991 gfp_t gfp_mask
, struct mem_cgroup
**memcgp
)
3994 if (mem_cgroup_disabled())
3997 * A racing thread's fault, or swapoff, may have already
3998 * updated the pte, and even removed page from swap cache: in
3999 * those cases unuse_pte()'s pte_same() test will fail; but
4000 * there's also a KSM case which does need to charge the page.
4002 if (!PageSwapCache(page
)) {
4005 ret
= __mem_cgroup_try_charge(mm
, gfp_mask
, 1, memcgp
, true);
4010 return __mem_cgroup_try_charge_swapin(mm
, page
, gfp_mask
, memcgp
);
4013 void mem_cgroup_cancel_charge_swapin(struct mem_cgroup
*memcg
)
4015 if (mem_cgroup_disabled())
4019 __mem_cgroup_cancel_charge(memcg
, 1);
4023 __mem_cgroup_commit_charge_swapin(struct page
*page
, struct mem_cgroup
*memcg
,
4024 enum charge_type ctype
)
4026 if (mem_cgroup_disabled())
4031 __mem_cgroup_commit_charge(memcg
, page
, 1, ctype
, true);
4033 * Now swap is on-memory. This means this page may be
4034 * counted both as mem and swap....double count.
4035 * Fix it by uncharging from memsw. Basically, this SwapCache is stable
4036 * under lock_page(). But in do_swap_page()::memory.c, reuse_swap_page()
4037 * may call delete_from_swap_cache() before reach here.
4039 if (do_swap_account
&& PageSwapCache(page
)) {
4040 swp_entry_t ent
= {.val
= page_private(page
)};
4041 mem_cgroup_uncharge_swap(ent
);
4045 void mem_cgroup_commit_charge_swapin(struct page
*page
,
4046 struct mem_cgroup
*memcg
)
4048 __mem_cgroup_commit_charge_swapin(page
, memcg
,
4049 MEM_CGROUP_CHARGE_TYPE_ANON
);
4052 int mem_cgroup_cache_charge(struct page
*page
, struct mm_struct
*mm
,
4055 struct mem_cgroup
*memcg
= NULL
;
4056 enum charge_type type
= MEM_CGROUP_CHARGE_TYPE_CACHE
;
4059 if (mem_cgroup_disabled())
4061 if (PageCompound(page
))
4064 if (!PageSwapCache(page
))
4065 ret
= mem_cgroup_charge_common(page
, mm
, gfp_mask
, type
);
4066 else { /* page is swapcache/shmem */
4067 ret
= __mem_cgroup_try_charge_swapin(mm
, page
,
4070 __mem_cgroup_commit_charge_swapin(page
, memcg
, type
);
4075 static void mem_cgroup_do_uncharge(struct mem_cgroup
*memcg
,
4076 unsigned int nr_pages
,
4077 const enum charge_type ctype
)
4079 struct memcg_batch_info
*batch
= NULL
;
4080 bool uncharge_memsw
= true;
4082 /* If swapout, usage of swap doesn't decrease */
4083 if (!do_swap_account
|| ctype
== MEM_CGROUP_CHARGE_TYPE_SWAPOUT
)
4084 uncharge_memsw
= false;
4086 batch
= ¤t
->memcg_batch
;
4088 * In usual, we do css_get() when we remember memcg pointer.
4089 * But in this case, we keep res->usage until end of a series of
4090 * uncharges. Then, it's ok to ignore memcg's refcnt.
4093 batch
->memcg
= memcg
;
4095 * do_batch > 0 when unmapping pages or inode invalidate/truncate.
4096 * In those cases, all pages freed continuously can be expected to be in
4097 * the same cgroup and we have chance to coalesce uncharges.
4098 * But we do uncharge one by one if this is killed by OOM(TIF_MEMDIE)
4099 * because we want to do uncharge as soon as possible.
4102 if (!batch
->do_batch
|| test_thread_flag(TIF_MEMDIE
))
4103 goto direct_uncharge
;
4106 goto direct_uncharge
;
4109 * In typical case, batch->memcg == mem. This means we can
4110 * merge a series of uncharges to an uncharge of res_counter.
4111 * If not, we uncharge res_counter ony by one.
4113 if (batch
->memcg
!= memcg
)
4114 goto direct_uncharge
;
4115 /* remember freed charge and uncharge it later */
4118 batch
->memsw_nr_pages
++;
4121 res_counter_uncharge(&memcg
->res
, nr_pages
* PAGE_SIZE
);
4123 res_counter_uncharge(&memcg
->memsw
, nr_pages
* PAGE_SIZE
);
4124 if (unlikely(batch
->memcg
!= memcg
))
4125 memcg_oom_recover(memcg
);
4129 * uncharge if !page_mapped(page)
4131 static struct mem_cgroup
*
4132 __mem_cgroup_uncharge_common(struct page
*page
, enum charge_type ctype
,
4135 struct mem_cgroup
*memcg
= NULL
;
4136 unsigned int nr_pages
= 1;
4137 struct page_cgroup
*pc
;
4140 if (mem_cgroup_disabled())
4143 if (PageTransHuge(page
)) {
4144 nr_pages
<<= compound_order(page
);
4145 VM_BUG_ON(!PageTransHuge(page
));
4148 * Check if our page_cgroup is valid
4150 pc
= lookup_page_cgroup(page
);
4151 if (unlikely(!PageCgroupUsed(pc
)))
4154 lock_page_cgroup(pc
);
4156 memcg
= pc
->mem_cgroup
;
4158 if (!PageCgroupUsed(pc
))
4161 anon
= PageAnon(page
);
4164 case MEM_CGROUP_CHARGE_TYPE_ANON
:
4166 * Generally PageAnon tells if it's the anon statistics to be
4167 * updated; but sometimes e.g. mem_cgroup_uncharge_page() is
4168 * used before page reached the stage of being marked PageAnon.
4172 case MEM_CGROUP_CHARGE_TYPE_DROP
:
4173 /* See mem_cgroup_prepare_migration() */
4174 if (page_mapped(page
))
4177 * Pages under migration may not be uncharged. But
4178 * end_migration() /must/ be the one uncharging the
4179 * unused post-migration page and so it has to call
4180 * here with the migration bit still set. See the
4181 * res_counter handling below.
4183 if (!end_migration
&& PageCgroupMigration(pc
))
4186 case MEM_CGROUP_CHARGE_TYPE_SWAPOUT
:
4187 if (!PageAnon(page
)) { /* Shared memory */
4188 if (page
->mapping
&& !page_is_file_cache(page
))
4190 } else if (page_mapped(page
)) /* Anon */
4197 mem_cgroup_charge_statistics(memcg
, page
, anon
, -nr_pages
);
4199 ClearPageCgroupUsed(pc
);
4201 * pc->mem_cgroup is not cleared here. It will be accessed when it's
4202 * freed from LRU. This is safe because uncharged page is expected not
4203 * to be reused (freed soon). Exception is SwapCache, it's handled by
4204 * special functions.
4207 unlock_page_cgroup(pc
);
4209 * even after unlock, we have memcg->res.usage here and this memcg
4210 * will never be freed, so it's safe to call css_get().
4212 memcg_check_events(memcg
, page
);
4213 if (do_swap_account
&& ctype
== MEM_CGROUP_CHARGE_TYPE_SWAPOUT
) {
4214 mem_cgroup_swap_statistics(memcg
, true);
4215 css_get(&memcg
->css
);
4218 * Migration does not charge the res_counter for the
4219 * replacement page, so leave it alone when phasing out the
4220 * page that is unused after the migration.
4222 if (!end_migration
&& !mem_cgroup_is_root(memcg
))
4223 mem_cgroup_do_uncharge(memcg
, nr_pages
, ctype
);
4228 unlock_page_cgroup(pc
);
4232 void mem_cgroup_uncharge_page(struct page
*page
)
4235 if (page_mapped(page
))
4237 VM_BUG_ON(page
->mapping
&& !PageAnon(page
));
4239 * If the page is in swap cache, uncharge should be deferred
4240 * to the swap path, which also properly accounts swap usage
4241 * and handles memcg lifetime.
4243 * Note that this check is not stable and reclaim may add the
4244 * page to swap cache at any time after this. However, if the
4245 * page is not in swap cache by the time page->mapcount hits
4246 * 0, there won't be any page table references to the swap
4247 * slot, and reclaim will free it and not actually write the
4250 if (PageSwapCache(page
))
4252 __mem_cgroup_uncharge_common(page
, MEM_CGROUP_CHARGE_TYPE_ANON
, false);
4255 void mem_cgroup_uncharge_cache_page(struct page
*page
)
4257 VM_BUG_ON(page_mapped(page
));
4258 VM_BUG_ON(page
->mapping
);
4259 __mem_cgroup_uncharge_common(page
, MEM_CGROUP_CHARGE_TYPE_CACHE
, false);
4263 * Batch_start/batch_end is called in unmap_page_range/invlidate/trucate.
4264 * In that cases, pages are freed continuously and we can expect pages
4265 * are in the same memcg. All these calls itself limits the number of
4266 * pages freed at once, then uncharge_start/end() is called properly.
4267 * This may be called prural(2) times in a context,
4270 void mem_cgroup_uncharge_start(void)
4272 current
->memcg_batch
.do_batch
++;
4273 /* We can do nest. */
4274 if (current
->memcg_batch
.do_batch
== 1) {
4275 current
->memcg_batch
.memcg
= NULL
;
4276 current
->memcg_batch
.nr_pages
= 0;
4277 current
->memcg_batch
.memsw_nr_pages
= 0;
4281 void mem_cgroup_uncharge_end(void)
4283 struct memcg_batch_info
*batch
= ¤t
->memcg_batch
;
4285 if (!batch
->do_batch
)
4289 if (batch
->do_batch
) /* If stacked, do nothing. */
4295 * This "batch->memcg" is valid without any css_get/put etc...
4296 * bacause we hide charges behind us.
4298 if (batch
->nr_pages
)
4299 res_counter_uncharge(&batch
->memcg
->res
,
4300 batch
->nr_pages
* PAGE_SIZE
);
4301 if (batch
->memsw_nr_pages
)
4302 res_counter_uncharge(&batch
->memcg
->memsw
,
4303 batch
->memsw_nr_pages
* PAGE_SIZE
);
4304 memcg_oom_recover(batch
->memcg
);
4305 /* forget this pointer (for sanity check) */
4306 batch
->memcg
= NULL
;
4311 * called after __delete_from_swap_cache() and drop "page" account.
4312 * memcg information is recorded to swap_cgroup of "ent"
4315 mem_cgroup_uncharge_swapcache(struct page
*page
, swp_entry_t ent
, bool swapout
)
4317 struct mem_cgroup
*memcg
;
4318 int ctype
= MEM_CGROUP_CHARGE_TYPE_SWAPOUT
;
4320 if (!swapout
) /* this was a swap cache but the swap is unused ! */
4321 ctype
= MEM_CGROUP_CHARGE_TYPE_DROP
;
4323 memcg
= __mem_cgroup_uncharge_common(page
, ctype
, false);
4326 * record memcg information, if swapout && memcg != NULL,
4327 * css_get() was called in uncharge().
4329 if (do_swap_account
&& swapout
&& memcg
)
4330 swap_cgroup_record(ent
, css_id(&memcg
->css
));
4334 #ifdef CONFIG_MEMCG_SWAP
4336 * called from swap_entry_free(). remove record in swap_cgroup and
4337 * uncharge "memsw" account.
4339 void mem_cgroup_uncharge_swap(swp_entry_t ent
)
4341 struct mem_cgroup
*memcg
;
4344 if (!do_swap_account
)
4347 id
= swap_cgroup_record(ent
, 0);
4349 memcg
= mem_cgroup_lookup(id
);
4352 * We uncharge this because swap is freed.
4353 * This memcg can be obsolete one. We avoid calling css_tryget
4355 if (!mem_cgroup_is_root(memcg
))
4356 res_counter_uncharge(&memcg
->memsw
, PAGE_SIZE
);
4357 mem_cgroup_swap_statistics(memcg
, false);
4358 css_put(&memcg
->css
);
4364 * mem_cgroup_move_swap_account - move swap charge and swap_cgroup's record.
4365 * @entry: swap entry to be moved
4366 * @from: mem_cgroup which the entry is moved from
4367 * @to: mem_cgroup which the entry is moved to
4369 * It succeeds only when the swap_cgroup's record for this entry is the same
4370 * as the mem_cgroup's id of @from.
4372 * Returns 0 on success, -EINVAL on failure.
4374 * The caller must have charged to @to, IOW, called res_counter_charge() about
4375 * both res and memsw, and called css_get().
4377 static int mem_cgroup_move_swap_account(swp_entry_t entry
,
4378 struct mem_cgroup
*from
, struct mem_cgroup
*to
)
4380 unsigned short old_id
, new_id
;
4382 old_id
= css_id(&from
->css
);
4383 new_id
= css_id(&to
->css
);
4385 if (swap_cgroup_cmpxchg(entry
, old_id
, new_id
) == old_id
) {
4386 mem_cgroup_swap_statistics(from
, false);
4387 mem_cgroup_swap_statistics(to
, true);
4389 * This function is only called from task migration context now.
4390 * It postpones res_counter and refcount handling till the end
4391 * of task migration(mem_cgroup_clear_mc()) for performance
4392 * improvement. But we cannot postpone css_get(to) because if
4393 * the process that has been moved to @to does swap-in, the
4394 * refcount of @to might be decreased to 0.
4396 * We are in attach() phase, so the cgroup is guaranteed to be
4397 * alive, so we can just call css_get().
4405 static inline int mem_cgroup_move_swap_account(swp_entry_t entry
,
4406 struct mem_cgroup
*from
, struct mem_cgroup
*to
)
4413 * Before starting migration, account PAGE_SIZE to mem_cgroup that the old
4416 void mem_cgroup_prepare_migration(struct page
*page
, struct page
*newpage
,
4417 struct mem_cgroup
**memcgp
)
4419 struct mem_cgroup
*memcg
= NULL
;
4420 unsigned int nr_pages
= 1;
4421 struct page_cgroup
*pc
;
4422 enum charge_type ctype
;
4426 if (mem_cgroup_disabled())
4429 if (PageTransHuge(page
))
4430 nr_pages
<<= compound_order(page
);
4432 pc
= lookup_page_cgroup(page
);
4433 lock_page_cgroup(pc
);
4434 if (PageCgroupUsed(pc
)) {
4435 memcg
= pc
->mem_cgroup
;
4436 css_get(&memcg
->css
);
4438 * At migrating an anonymous page, its mapcount goes down
4439 * to 0 and uncharge() will be called. But, even if it's fully
4440 * unmapped, migration may fail and this page has to be
4441 * charged again. We set MIGRATION flag here and delay uncharge
4442 * until end_migration() is called
4444 * Corner Case Thinking
4446 * When the old page was mapped as Anon and it's unmap-and-freed
4447 * while migration was ongoing.
4448 * If unmap finds the old page, uncharge() of it will be delayed
4449 * until end_migration(). If unmap finds a new page, it's
4450 * uncharged when it make mapcount to be 1->0. If unmap code
4451 * finds swap_migration_entry, the new page will not be mapped
4452 * and end_migration() will find it(mapcount==0).
4455 * When the old page was mapped but migraion fails, the kernel
4456 * remaps it. A charge for it is kept by MIGRATION flag even
4457 * if mapcount goes down to 0. We can do remap successfully
4458 * without charging it again.
4461 * The "old" page is under lock_page() until the end of
4462 * migration, so, the old page itself will not be swapped-out.
4463 * If the new page is swapped out before end_migraton, our
4464 * hook to usual swap-out path will catch the event.
4467 SetPageCgroupMigration(pc
);
4469 unlock_page_cgroup(pc
);
4471 * If the page is not charged at this point,
4479 * We charge new page before it's used/mapped. So, even if unlock_page()
4480 * is called before end_migration, we can catch all events on this new
4481 * page. In the case new page is migrated but not remapped, new page's
4482 * mapcount will be finally 0 and we call uncharge in end_migration().
4485 ctype
= MEM_CGROUP_CHARGE_TYPE_ANON
;
4487 ctype
= MEM_CGROUP_CHARGE_TYPE_CACHE
;
4489 * The page is committed to the memcg, but it's not actually
4490 * charged to the res_counter since we plan on replacing the
4491 * old one and only one page is going to be left afterwards.
4493 __mem_cgroup_commit_charge(memcg
, newpage
, nr_pages
, ctype
, false);
4496 /* remove redundant charge if migration failed*/
4497 void mem_cgroup_end_migration(struct mem_cgroup
*memcg
,
4498 struct page
*oldpage
, struct page
*newpage
, bool migration_ok
)
4500 struct page
*used
, *unused
;
4501 struct page_cgroup
*pc
;
4507 if (!migration_ok
) {
4514 anon
= PageAnon(used
);
4515 __mem_cgroup_uncharge_common(unused
,
4516 anon
? MEM_CGROUP_CHARGE_TYPE_ANON
4517 : MEM_CGROUP_CHARGE_TYPE_CACHE
,
4519 css_put(&memcg
->css
);
4521 * We disallowed uncharge of pages under migration because mapcount
4522 * of the page goes down to zero, temporarly.
4523 * Clear the flag and check the page should be charged.
4525 pc
= lookup_page_cgroup(oldpage
);
4526 lock_page_cgroup(pc
);
4527 ClearPageCgroupMigration(pc
);
4528 unlock_page_cgroup(pc
);
4531 * If a page is a file cache, radix-tree replacement is very atomic
4532 * and we can skip this check. When it was an Anon page, its mapcount
4533 * goes down to 0. But because we added MIGRATION flage, it's not
4534 * uncharged yet. There are several case but page->mapcount check
4535 * and USED bit check in mem_cgroup_uncharge_page() will do enough
4536 * check. (see prepare_charge() also)
4539 mem_cgroup_uncharge_page(used
);
4543 * At replace page cache, newpage is not under any memcg but it's on
4544 * LRU. So, this function doesn't touch res_counter but handles LRU
4545 * in correct way. Both pages are locked so we cannot race with uncharge.
4547 void mem_cgroup_replace_page_cache(struct page
*oldpage
,
4548 struct page
*newpage
)
4550 struct mem_cgroup
*memcg
= NULL
;
4551 struct page_cgroup
*pc
;
4552 enum charge_type type
= MEM_CGROUP_CHARGE_TYPE_CACHE
;
4554 if (mem_cgroup_disabled())
4557 pc
= lookup_page_cgroup(oldpage
);
4558 /* fix accounting on old pages */
4559 lock_page_cgroup(pc
);
4560 if (PageCgroupUsed(pc
)) {
4561 memcg
= pc
->mem_cgroup
;
4562 mem_cgroup_charge_statistics(memcg
, oldpage
, false, -1);
4563 ClearPageCgroupUsed(pc
);
4565 unlock_page_cgroup(pc
);
4568 * When called from shmem_replace_page(), in some cases the
4569 * oldpage has already been charged, and in some cases not.
4574 * Even if newpage->mapping was NULL before starting replacement,
4575 * the newpage may be on LRU(or pagevec for LRU) already. We lock
4576 * LRU while we overwrite pc->mem_cgroup.
4578 __mem_cgroup_commit_charge(memcg
, newpage
, 1, type
, true);
4581 #ifdef CONFIG_DEBUG_VM
4582 static struct page_cgroup
*lookup_page_cgroup_used(struct page
*page
)
4584 struct page_cgroup
*pc
;
4586 pc
= lookup_page_cgroup(page
);
4588 * Can be NULL while feeding pages into the page allocator for
4589 * the first time, i.e. during boot or memory hotplug;
4590 * or when mem_cgroup_disabled().
4592 if (likely(pc
) && PageCgroupUsed(pc
))
4597 bool mem_cgroup_bad_page_check(struct page
*page
)
4599 if (mem_cgroup_disabled())
4602 return lookup_page_cgroup_used(page
) != NULL
;
4605 void mem_cgroup_print_bad_page(struct page
*page
)
4607 struct page_cgroup
*pc
;
4609 pc
= lookup_page_cgroup_used(page
);
4611 pr_alert("pc:%p pc->flags:%lx pc->mem_cgroup:%p\n",
4612 pc
, pc
->flags
, pc
->mem_cgroup
);
4617 static int mem_cgroup_resize_limit(struct mem_cgroup
*memcg
,
4618 unsigned long long val
)
4621 u64 memswlimit
, memlimit
;
4623 int children
= mem_cgroup_count_children(memcg
);
4624 u64 curusage
, oldusage
;
4628 * For keeping hierarchical_reclaim simple, how long we should retry
4629 * is depends on callers. We set our retry-count to be function
4630 * of # of children which we should visit in this loop.
4632 retry_count
= MEM_CGROUP_RECLAIM_RETRIES
* children
;
4634 oldusage
= res_counter_read_u64(&memcg
->res
, RES_USAGE
);
4637 while (retry_count
) {
4638 if (signal_pending(current
)) {
4643 * Rather than hide all in some function, I do this in
4644 * open coded manner. You see what this really does.
4645 * We have to guarantee memcg->res.limit <= memcg->memsw.limit.
4647 mutex_lock(&set_limit_mutex
);
4648 memswlimit
= res_counter_read_u64(&memcg
->memsw
, RES_LIMIT
);
4649 if (memswlimit
< val
) {
4651 mutex_unlock(&set_limit_mutex
);
4655 memlimit
= res_counter_read_u64(&memcg
->res
, RES_LIMIT
);
4659 ret
= res_counter_set_limit(&memcg
->res
, val
);
4661 if (memswlimit
== val
)
4662 memcg
->memsw_is_minimum
= true;
4664 memcg
->memsw_is_minimum
= false;
4666 mutex_unlock(&set_limit_mutex
);
4671 mem_cgroup_reclaim(memcg
, GFP_KERNEL
,
4672 MEM_CGROUP_RECLAIM_SHRINK
);
4673 curusage
= res_counter_read_u64(&memcg
->res
, RES_USAGE
);
4674 /* Usage is reduced ? */
4675 if (curusage
>= oldusage
)
4678 oldusage
= curusage
;
4680 if (!ret
&& enlarge
)
4681 memcg_oom_recover(memcg
);
4686 static int mem_cgroup_resize_memsw_limit(struct mem_cgroup
*memcg
,
4687 unsigned long long val
)
4690 u64 memlimit
, memswlimit
, oldusage
, curusage
;
4691 int children
= mem_cgroup_count_children(memcg
);
4695 /* see mem_cgroup_resize_res_limit */
4696 retry_count
= children
* MEM_CGROUP_RECLAIM_RETRIES
;
4697 oldusage
= res_counter_read_u64(&memcg
->memsw
, RES_USAGE
);
4698 while (retry_count
) {
4699 if (signal_pending(current
)) {
4704 * Rather than hide all in some function, I do this in
4705 * open coded manner. You see what this really does.
4706 * We have to guarantee memcg->res.limit <= memcg->memsw.limit.
4708 mutex_lock(&set_limit_mutex
);
4709 memlimit
= res_counter_read_u64(&memcg
->res
, RES_LIMIT
);
4710 if (memlimit
> val
) {
4712 mutex_unlock(&set_limit_mutex
);
4715 memswlimit
= res_counter_read_u64(&memcg
->memsw
, RES_LIMIT
);
4716 if (memswlimit
< val
)
4718 ret
= res_counter_set_limit(&memcg
->memsw
, val
);
4720 if (memlimit
== val
)
4721 memcg
->memsw_is_minimum
= true;
4723 memcg
->memsw_is_minimum
= false;
4725 mutex_unlock(&set_limit_mutex
);
4730 mem_cgroup_reclaim(memcg
, GFP_KERNEL
,
4731 MEM_CGROUP_RECLAIM_NOSWAP
|
4732 MEM_CGROUP_RECLAIM_SHRINK
);
4733 curusage
= res_counter_read_u64(&memcg
->memsw
, RES_USAGE
);
4734 /* Usage is reduced ? */
4735 if (curusage
>= oldusage
)
4738 oldusage
= curusage
;
4740 if (!ret
&& enlarge
)
4741 memcg_oom_recover(memcg
);
4745 unsigned long mem_cgroup_soft_limit_reclaim(struct zone
*zone
, int order
,
4747 unsigned long *total_scanned
)
4749 unsigned long nr_reclaimed
= 0;
4750 struct mem_cgroup_per_zone
*mz
, *next_mz
= NULL
;
4751 unsigned long reclaimed
;
4753 struct mem_cgroup_tree_per_zone
*mctz
;
4754 unsigned long long excess
;
4755 unsigned long nr_scanned
;
4760 mctz
= soft_limit_tree_node_zone(zone_to_nid(zone
), zone_idx(zone
));
4762 * This loop can run a while, specially if mem_cgroup's continuously
4763 * keep exceeding their soft limit and putting the system under
4770 mz
= mem_cgroup_largest_soft_limit_node(mctz
);
4775 reclaimed
= mem_cgroup_soft_reclaim(mz
->memcg
, zone
,
4776 gfp_mask
, &nr_scanned
);
4777 nr_reclaimed
+= reclaimed
;
4778 *total_scanned
+= nr_scanned
;
4779 spin_lock(&mctz
->lock
);
4782 * If we failed to reclaim anything from this memory cgroup
4783 * it is time to move on to the next cgroup
4789 * Loop until we find yet another one.
4791 * By the time we get the soft_limit lock
4792 * again, someone might have aded the
4793 * group back on the RB tree. Iterate to
4794 * make sure we get a different mem.
4795 * mem_cgroup_largest_soft_limit_node returns
4796 * NULL if no other cgroup is present on
4800 __mem_cgroup_largest_soft_limit_node(mctz
);
4802 css_put(&next_mz
->memcg
->css
);
4803 else /* next_mz == NULL or other memcg */
4807 __mem_cgroup_remove_exceeded(mz
->memcg
, mz
, mctz
);
4808 excess
= res_counter_soft_limit_excess(&mz
->memcg
->res
);
4810 * One school of thought says that we should not add
4811 * back the node to the tree if reclaim returns 0.
4812 * But our reclaim could return 0, simply because due
4813 * to priority we are exposing a smaller subset of
4814 * memory to reclaim from. Consider this as a longer
4817 /* If excess == 0, no tree ops */
4818 __mem_cgroup_insert_exceeded(mz
->memcg
, mz
, mctz
, excess
);
4819 spin_unlock(&mctz
->lock
);
4820 css_put(&mz
->memcg
->css
);
4823 * Could not reclaim anything and there are no more
4824 * mem cgroups to try or we seem to be looping without
4825 * reclaiming anything.
4827 if (!nr_reclaimed
&&
4829 loop
> MEM_CGROUP_MAX_SOFT_LIMIT_RECLAIM_LOOPS
))
4831 } while (!nr_reclaimed
);
4833 css_put(&next_mz
->memcg
->css
);
4834 return nr_reclaimed
;
4838 * mem_cgroup_force_empty_list - clears LRU of a group
4839 * @memcg: group to clear
4842 * @lru: lru to to clear
4844 * Traverse a specified page_cgroup list and try to drop them all. This doesn't
4845 * reclaim the pages page themselves - pages are moved to the parent (or root)
4848 static void mem_cgroup_force_empty_list(struct mem_cgroup
*memcg
,
4849 int node
, int zid
, enum lru_list lru
)
4851 struct lruvec
*lruvec
;
4852 unsigned long flags
;
4853 struct list_head
*list
;
4857 zone
= &NODE_DATA(node
)->node_zones
[zid
];
4858 lruvec
= mem_cgroup_zone_lruvec(zone
, memcg
);
4859 list
= &lruvec
->lists
[lru
];
4863 struct page_cgroup
*pc
;
4866 spin_lock_irqsave(&zone
->lru_lock
, flags
);
4867 if (list_empty(list
)) {
4868 spin_unlock_irqrestore(&zone
->lru_lock
, flags
);
4871 page
= list_entry(list
->prev
, struct page
, lru
);
4873 list_move(&page
->lru
, list
);
4875 spin_unlock_irqrestore(&zone
->lru_lock
, flags
);
4878 spin_unlock_irqrestore(&zone
->lru_lock
, flags
);
4880 pc
= lookup_page_cgroup(page
);
4882 if (mem_cgroup_move_parent(page
, pc
, memcg
)) {
4883 /* found lock contention or "pc" is obsolete. */
4888 } while (!list_empty(list
));
4892 * make mem_cgroup's charge to be 0 if there is no task by moving
4893 * all the charges and pages to the parent.
4894 * This enables deleting this mem_cgroup.
4896 * Caller is responsible for holding css reference on the memcg.
4898 static void mem_cgroup_reparent_charges(struct mem_cgroup
*memcg
)
4904 /* This is for making all *used* pages to be on LRU. */
4905 lru_add_drain_all();
4906 drain_all_stock_sync(memcg
);
4907 mem_cgroup_start_move(memcg
);
4908 for_each_node_state(node
, N_MEMORY
) {
4909 for (zid
= 0; zid
< MAX_NR_ZONES
; zid
++) {
4912 mem_cgroup_force_empty_list(memcg
,
4917 mem_cgroup_end_move(memcg
);
4918 memcg_oom_recover(memcg
);
4922 * Kernel memory may not necessarily be trackable to a specific
4923 * process. So they are not migrated, and therefore we can't
4924 * expect their value to drop to 0 here.
4925 * Having res filled up with kmem only is enough.
4927 * This is a safety check because mem_cgroup_force_empty_list
4928 * could have raced with mem_cgroup_replace_page_cache callers
4929 * so the lru seemed empty but the page could have been added
4930 * right after the check. RES_USAGE should be safe as we always
4931 * charge before adding to the LRU.
4933 usage
= res_counter_read_u64(&memcg
->res
, RES_USAGE
) -
4934 res_counter_read_u64(&memcg
->kmem
, RES_USAGE
);
4935 } while (usage
> 0);
4939 * This mainly exists for tests during the setting of set of use_hierarchy.
4940 * Since this is the very setting we are changing, the current hierarchy value
4943 static inline bool __memcg_has_children(struct mem_cgroup
*memcg
)
4947 /* bounce at first found */
4948 cgroup_for_each_child(pos
, memcg
->css
.cgroup
)
4954 * Must be called with memcg_create_mutex held, unless the cgroup is guaranteed
4955 * to be already dead (as in mem_cgroup_force_empty, for instance). This is
4956 * from mem_cgroup_count_children(), in the sense that we don't really care how
4957 * many children we have; we only need to know if we have any. It also counts
4958 * any memcg without hierarchy as infertile.
4960 static inline bool memcg_has_children(struct mem_cgroup
*memcg
)
4962 return memcg
->use_hierarchy
&& __memcg_has_children(memcg
);
4966 * Reclaims as many pages from the given memcg as possible and moves
4967 * the rest to the parent.
4969 * Caller is responsible for holding css reference for memcg.
4971 static int mem_cgroup_force_empty(struct mem_cgroup
*memcg
)
4973 int nr_retries
= MEM_CGROUP_RECLAIM_RETRIES
;
4974 struct cgroup
*cgrp
= memcg
->css
.cgroup
;
4976 /* returns EBUSY if there is a task or if we come here twice. */
4977 if (cgroup_task_count(cgrp
) || !list_empty(&cgrp
->children
))
4980 /* we call try-to-free pages for make this cgroup empty */
4981 lru_add_drain_all();
4982 /* try to free all pages in this cgroup */
4983 while (nr_retries
&& res_counter_read_u64(&memcg
->res
, RES_USAGE
) > 0) {
4986 if (signal_pending(current
))
4989 progress
= try_to_free_mem_cgroup_pages(memcg
, GFP_KERNEL
,
4993 /* maybe some writeback is necessary */
4994 congestion_wait(BLK_RW_ASYNC
, HZ
/10);
4999 mem_cgroup_reparent_charges(memcg
);
5004 static int mem_cgroup_force_empty_write(struct cgroup
*cont
, unsigned int event
)
5006 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cont
);
5009 if (mem_cgroup_is_root(memcg
))
5011 css_get(&memcg
->css
);
5012 ret
= mem_cgroup_force_empty(memcg
);
5013 css_put(&memcg
->css
);
5019 static u64
mem_cgroup_hierarchy_read(struct cgroup
*cont
, struct cftype
*cft
)
5021 return mem_cgroup_from_cont(cont
)->use_hierarchy
;
5024 static int mem_cgroup_hierarchy_write(struct cgroup
*cont
, struct cftype
*cft
,
5028 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cont
);
5029 struct cgroup
*parent
= cont
->parent
;
5030 struct mem_cgroup
*parent_memcg
= NULL
;
5033 parent_memcg
= mem_cgroup_from_cont(parent
);
5035 mutex_lock(&memcg_create_mutex
);
5037 if (memcg
->use_hierarchy
== val
)
5041 * If parent's use_hierarchy is set, we can't make any modifications
5042 * in the child subtrees. If it is unset, then the change can
5043 * occur, provided the current cgroup has no children.
5045 * For the root cgroup, parent_mem is NULL, we allow value to be
5046 * set if there are no children.
5048 if ((!parent_memcg
|| !parent_memcg
->use_hierarchy
) &&
5049 (val
== 1 || val
== 0)) {
5050 if (!__memcg_has_children(memcg
))
5051 memcg
->use_hierarchy
= val
;
5058 mutex_unlock(&memcg_create_mutex
);
5064 static unsigned long mem_cgroup_recursive_stat(struct mem_cgroup
*memcg
,
5065 enum mem_cgroup_stat_index idx
)
5067 struct mem_cgroup
*iter
;
5070 /* Per-cpu values can be negative, use a signed accumulator */
5071 for_each_mem_cgroup_tree(iter
, memcg
)
5072 val
+= mem_cgroup_read_stat(iter
, idx
);
5074 if (val
< 0) /* race ? */
5079 static inline u64
mem_cgroup_usage(struct mem_cgroup
*memcg
, bool swap
)
5083 if (!mem_cgroup_is_root(memcg
)) {
5085 return res_counter_read_u64(&memcg
->res
, RES_USAGE
);
5087 return res_counter_read_u64(&memcg
->memsw
, RES_USAGE
);
5091 * Transparent hugepages are still accounted for in MEM_CGROUP_STAT_RSS
5092 * as well as in MEM_CGROUP_STAT_RSS_HUGE.
5094 val
= mem_cgroup_recursive_stat(memcg
, MEM_CGROUP_STAT_CACHE
);
5095 val
+= mem_cgroup_recursive_stat(memcg
, MEM_CGROUP_STAT_RSS
);
5098 val
+= mem_cgroup_recursive_stat(memcg
, MEM_CGROUP_STAT_SWAP
);
5100 return val
<< PAGE_SHIFT
;
5103 static ssize_t
mem_cgroup_read(struct cgroup
*cont
, struct cftype
*cft
,
5104 struct file
*file
, char __user
*buf
,
5105 size_t nbytes
, loff_t
*ppos
)
5107 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cont
);
5113 type
= MEMFILE_TYPE(cft
->private);
5114 name
= MEMFILE_ATTR(cft
->private);
5118 if (name
== RES_USAGE
)
5119 val
= mem_cgroup_usage(memcg
, false);
5121 val
= res_counter_read_u64(&memcg
->res
, name
);
5124 if (name
== RES_USAGE
)
5125 val
= mem_cgroup_usage(memcg
, true);
5127 val
= res_counter_read_u64(&memcg
->memsw
, name
);
5130 val
= res_counter_read_u64(&memcg
->kmem
, name
);
5136 len
= scnprintf(str
, sizeof(str
), "%llu\n", (unsigned long long)val
);
5137 return simple_read_from_buffer(buf
, nbytes
, ppos
, str
, len
);
5140 static int memcg_update_kmem_limit(struct cgroup
*cont
, u64 val
)
5143 #ifdef CONFIG_MEMCG_KMEM
5144 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cont
);
5146 * For simplicity, we won't allow this to be disabled. It also can't
5147 * be changed if the cgroup has children already, or if tasks had
5150 * If tasks join before we set the limit, a person looking at
5151 * kmem.usage_in_bytes will have no way to determine when it took
5152 * place, which makes the value quite meaningless.
5154 * After it first became limited, changes in the value of the limit are
5155 * of course permitted.
5157 mutex_lock(&memcg_create_mutex
);
5158 mutex_lock(&set_limit_mutex
);
5159 if (!memcg
->kmem_account_flags
&& val
!= RESOURCE_MAX
) {
5160 if (cgroup_task_count(cont
) || memcg_has_children(memcg
)) {
5164 ret
= res_counter_set_limit(&memcg
->kmem
, val
);
5167 ret
= memcg_update_cache_sizes(memcg
);
5169 res_counter_set_limit(&memcg
->kmem
, RESOURCE_MAX
);
5172 static_key_slow_inc(&memcg_kmem_enabled_key
);
5174 * setting the active bit after the inc will guarantee no one
5175 * starts accounting before all call sites are patched
5177 memcg_kmem_set_active(memcg
);
5179 ret
= res_counter_set_limit(&memcg
->kmem
, val
);
5181 mutex_unlock(&set_limit_mutex
);
5182 mutex_unlock(&memcg_create_mutex
);
5187 #ifdef CONFIG_MEMCG_KMEM
5188 static int memcg_propagate_kmem(struct mem_cgroup
*memcg
)
5191 struct mem_cgroup
*parent
= parent_mem_cgroup(memcg
);
5195 memcg
->kmem_account_flags
= parent
->kmem_account_flags
;
5197 * When that happen, we need to disable the static branch only on those
5198 * memcgs that enabled it. To achieve this, we would be forced to
5199 * complicate the code by keeping track of which memcgs were the ones
5200 * that actually enabled limits, and which ones got it from its
5203 * It is a lot simpler just to do static_key_slow_inc() on every child
5204 * that is accounted.
5206 if (!memcg_kmem_is_active(memcg
))
5210 * __mem_cgroup_free() will issue static_key_slow_dec() because this
5211 * memcg is active already. If the later initialization fails then the
5212 * cgroup core triggers the cleanup so we do not have to do it here.
5214 static_key_slow_inc(&memcg_kmem_enabled_key
);
5216 mutex_lock(&set_limit_mutex
);
5217 memcg_stop_kmem_account();
5218 ret
= memcg_update_cache_sizes(memcg
);
5219 memcg_resume_kmem_account();
5220 mutex_unlock(&set_limit_mutex
);
5224 #endif /* CONFIG_MEMCG_KMEM */
5227 * The user of this function is...
5230 static int mem_cgroup_write(struct cgroup
*cont
, struct cftype
*cft
,
5233 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cont
);
5236 unsigned long long val
;
5239 type
= MEMFILE_TYPE(cft
->private);
5240 name
= MEMFILE_ATTR(cft
->private);
5244 if (mem_cgroup_is_root(memcg
)) { /* Can't set limit on root */
5248 /* This function does all necessary parse...reuse it */
5249 ret
= res_counter_memparse_write_strategy(buffer
, &val
);
5253 ret
= mem_cgroup_resize_limit(memcg
, val
);
5254 else if (type
== _MEMSWAP
)
5255 ret
= mem_cgroup_resize_memsw_limit(memcg
, val
);
5256 else if (type
== _KMEM
)
5257 ret
= memcg_update_kmem_limit(cont
, val
);
5261 case RES_SOFT_LIMIT
:
5262 ret
= res_counter_memparse_write_strategy(buffer
, &val
);
5266 * For memsw, soft limits are hard to implement in terms
5267 * of semantics, for now, we support soft limits for
5268 * control without swap
5271 ret
= res_counter_set_soft_limit(&memcg
->res
, val
);
5276 ret
= -EINVAL
; /* should be BUG() ? */
5282 static void memcg_get_hierarchical_limit(struct mem_cgroup
*memcg
,
5283 unsigned long long *mem_limit
, unsigned long long *memsw_limit
)
5285 struct cgroup
*cgroup
;
5286 unsigned long long min_limit
, min_memsw_limit
, tmp
;
5288 min_limit
= res_counter_read_u64(&memcg
->res
, RES_LIMIT
);
5289 min_memsw_limit
= res_counter_read_u64(&memcg
->memsw
, RES_LIMIT
);
5290 cgroup
= memcg
->css
.cgroup
;
5291 if (!memcg
->use_hierarchy
)
5294 while (cgroup
->parent
) {
5295 cgroup
= cgroup
->parent
;
5296 memcg
= mem_cgroup_from_cont(cgroup
);
5297 if (!memcg
->use_hierarchy
)
5299 tmp
= res_counter_read_u64(&memcg
->res
, RES_LIMIT
);
5300 min_limit
= min(min_limit
, tmp
);
5301 tmp
= res_counter_read_u64(&memcg
->memsw
, RES_LIMIT
);
5302 min_memsw_limit
= min(min_memsw_limit
, tmp
);
5305 *mem_limit
= min_limit
;
5306 *memsw_limit
= min_memsw_limit
;
5309 static int mem_cgroup_reset(struct cgroup
*cont
, unsigned int event
)
5311 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cont
);
5315 type
= MEMFILE_TYPE(event
);
5316 name
= MEMFILE_ATTR(event
);
5321 res_counter_reset_max(&memcg
->res
);
5322 else if (type
== _MEMSWAP
)
5323 res_counter_reset_max(&memcg
->memsw
);
5324 else if (type
== _KMEM
)
5325 res_counter_reset_max(&memcg
->kmem
);
5331 res_counter_reset_failcnt(&memcg
->res
);
5332 else if (type
== _MEMSWAP
)
5333 res_counter_reset_failcnt(&memcg
->memsw
);
5334 else if (type
== _KMEM
)
5335 res_counter_reset_failcnt(&memcg
->kmem
);
5344 static u64
mem_cgroup_move_charge_read(struct cgroup
*cgrp
,
5347 return mem_cgroup_from_cont(cgrp
)->move_charge_at_immigrate
;
5351 static int mem_cgroup_move_charge_write(struct cgroup
*cgrp
,
5352 struct cftype
*cft
, u64 val
)
5354 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cgrp
);
5356 if (val
>= (1 << NR_MOVE_TYPE
))
5360 * No kind of locking is needed in here, because ->can_attach() will
5361 * check this value once in the beginning of the process, and then carry
5362 * on with stale data. This means that changes to this value will only
5363 * affect task migrations starting after the change.
5365 memcg
->move_charge_at_immigrate
= val
;
5369 static int mem_cgroup_move_charge_write(struct cgroup
*cgrp
,
5370 struct cftype
*cft
, u64 val
)
5377 static int memcg_numa_stat_show(struct cgroup
*cont
, struct cftype
*cft
,
5381 unsigned long total_nr
, file_nr
, anon_nr
, unevictable_nr
;
5382 unsigned long node_nr
;
5383 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cont
);
5385 total_nr
= mem_cgroup_nr_lru_pages(memcg
, LRU_ALL
);
5386 seq_printf(m
, "total=%lu", total_nr
);
5387 for_each_node_state(nid
, N_MEMORY
) {
5388 node_nr
= mem_cgroup_node_nr_lru_pages(memcg
, nid
, LRU_ALL
);
5389 seq_printf(m
, " N%d=%lu", nid
, node_nr
);
5393 file_nr
= mem_cgroup_nr_lru_pages(memcg
, LRU_ALL_FILE
);
5394 seq_printf(m
, "file=%lu", file_nr
);
5395 for_each_node_state(nid
, N_MEMORY
) {
5396 node_nr
= mem_cgroup_node_nr_lru_pages(memcg
, nid
,
5398 seq_printf(m
, " N%d=%lu", nid
, node_nr
);
5402 anon_nr
= mem_cgroup_nr_lru_pages(memcg
, LRU_ALL_ANON
);
5403 seq_printf(m
, "anon=%lu", anon_nr
);
5404 for_each_node_state(nid
, N_MEMORY
) {
5405 node_nr
= mem_cgroup_node_nr_lru_pages(memcg
, nid
,
5407 seq_printf(m
, " N%d=%lu", nid
, node_nr
);
5411 unevictable_nr
= mem_cgroup_nr_lru_pages(memcg
, BIT(LRU_UNEVICTABLE
));
5412 seq_printf(m
, "unevictable=%lu", unevictable_nr
);
5413 for_each_node_state(nid
, N_MEMORY
) {
5414 node_nr
= mem_cgroup_node_nr_lru_pages(memcg
, nid
,
5415 BIT(LRU_UNEVICTABLE
));
5416 seq_printf(m
, " N%d=%lu", nid
, node_nr
);
5421 #endif /* CONFIG_NUMA */
5423 static inline void mem_cgroup_lru_names_not_uptodate(void)
5425 BUILD_BUG_ON(ARRAY_SIZE(mem_cgroup_lru_names
) != NR_LRU_LISTS
);
5428 static int memcg_stat_show(struct cgroup
*cont
, struct cftype
*cft
,
5431 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cont
);
5432 struct mem_cgroup
*mi
;
5435 for (i
= 0; i
< MEM_CGROUP_STAT_NSTATS
; i
++) {
5436 if (i
== MEM_CGROUP_STAT_SWAP
&& !do_swap_account
)
5438 seq_printf(m
, "%s %ld\n", mem_cgroup_stat_names
[i
],
5439 mem_cgroup_read_stat(memcg
, i
) * PAGE_SIZE
);
5442 for (i
= 0; i
< MEM_CGROUP_EVENTS_NSTATS
; i
++)
5443 seq_printf(m
, "%s %lu\n", mem_cgroup_events_names
[i
],
5444 mem_cgroup_read_events(memcg
, i
));
5446 for (i
= 0; i
< NR_LRU_LISTS
; i
++)
5447 seq_printf(m
, "%s %lu\n", mem_cgroup_lru_names
[i
],
5448 mem_cgroup_nr_lru_pages(memcg
, BIT(i
)) * PAGE_SIZE
);
5450 /* Hierarchical information */
5452 unsigned long long limit
, memsw_limit
;
5453 memcg_get_hierarchical_limit(memcg
, &limit
, &memsw_limit
);
5454 seq_printf(m
, "hierarchical_memory_limit %llu\n", limit
);
5455 if (do_swap_account
)
5456 seq_printf(m
, "hierarchical_memsw_limit %llu\n",
5460 for (i
= 0; i
< MEM_CGROUP_STAT_NSTATS
; i
++) {
5463 if (i
== MEM_CGROUP_STAT_SWAP
&& !do_swap_account
)
5465 for_each_mem_cgroup_tree(mi
, memcg
)
5466 val
+= mem_cgroup_read_stat(mi
, i
) * PAGE_SIZE
;
5467 seq_printf(m
, "total_%s %lld\n", mem_cgroup_stat_names
[i
], val
);
5470 for (i
= 0; i
< MEM_CGROUP_EVENTS_NSTATS
; i
++) {
5471 unsigned long long val
= 0;
5473 for_each_mem_cgroup_tree(mi
, memcg
)
5474 val
+= mem_cgroup_read_events(mi
, i
);
5475 seq_printf(m
, "total_%s %llu\n",
5476 mem_cgroup_events_names
[i
], val
);
5479 for (i
= 0; i
< NR_LRU_LISTS
; i
++) {
5480 unsigned long long val
= 0;
5482 for_each_mem_cgroup_tree(mi
, memcg
)
5483 val
+= mem_cgroup_nr_lru_pages(mi
, BIT(i
)) * PAGE_SIZE
;
5484 seq_printf(m
, "total_%s %llu\n", mem_cgroup_lru_names
[i
], val
);
5487 #ifdef CONFIG_DEBUG_VM
5490 struct mem_cgroup_per_zone
*mz
;
5491 struct zone_reclaim_stat
*rstat
;
5492 unsigned long recent_rotated
[2] = {0, 0};
5493 unsigned long recent_scanned
[2] = {0, 0};
5495 for_each_online_node(nid
)
5496 for (zid
= 0; zid
< MAX_NR_ZONES
; zid
++) {
5497 mz
= mem_cgroup_zoneinfo(memcg
, nid
, zid
);
5498 rstat
= &mz
->lruvec
.reclaim_stat
;
5500 recent_rotated
[0] += rstat
->recent_rotated
[0];
5501 recent_rotated
[1] += rstat
->recent_rotated
[1];
5502 recent_scanned
[0] += rstat
->recent_scanned
[0];
5503 recent_scanned
[1] += rstat
->recent_scanned
[1];
5505 seq_printf(m
, "recent_rotated_anon %lu\n", recent_rotated
[0]);
5506 seq_printf(m
, "recent_rotated_file %lu\n", recent_rotated
[1]);
5507 seq_printf(m
, "recent_scanned_anon %lu\n", recent_scanned
[0]);
5508 seq_printf(m
, "recent_scanned_file %lu\n", recent_scanned
[1]);
5515 static u64
mem_cgroup_swappiness_read(struct cgroup
*cgrp
, struct cftype
*cft
)
5517 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cgrp
);
5519 return mem_cgroup_swappiness(memcg
);
5522 static int mem_cgroup_swappiness_write(struct cgroup
*cgrp
, struct cftype
*cft
,
5525 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cgrp
);
5526 struct mem_cgroup
*parent
;
5531 if (cgrp
->parent
== NULL
)
5534 parent
= mem_cgroup_from_cont(cgrp
->parent
);
5536 mutex_lock(&memcg_create_mutex
);
5538 /* If under hierarchy, only empty-root can set this value */
5539 if ((parent
->use_hierarchy
) || memcg_has_children(memcg
)) {
5540 mutex_unlock(&memcg_create_mutex
);
5544 memcg
->swappiness
= val
;
5546 mutex_unlock(&memcg_create_mutex
);
5551 static void __mem_cgroup_threshold(struct mem_cgroup
*memcg
, bool swap
)
5553 struct mem_cgroup_threshold_ary
*t
;
5559 t
= rcu_dereference(memcg
->thresholds
.primary
);
5561 t
= rcu_dereference(memcg
->memsw_thresholds
.primary
);
5566 usage
= mem_cgroup_usage(memcg
, swap
);
5569 * current_threshold points to threshold just below or equal to usage.
5570 * If it's not true, a threshold was crossed after last
5571 * call of __mem_cgroup_threshold().
5573 i
= t
->current_threshold
;
5576 * Iterate backward over array of thresholds starting from
5577 * current_threshold and check if a threshold is crossed.
5578 * If none of thresholds below usage is crossed, we read
5579 * only one element of the array here.
5581 for (; i
>= 0 && unlikely(t
->entries
[i
].threshold
> usage
); i
--)
5582 eventfd_signal(t
->entries
[i
].eventfd
, 1);
5584 /* i = current_threshold + 1 */
5588 * Iterate forward over array of thresholds starting from
5589 * current_threshold+1 and check if a threshold is crossed.
5590 * If none of thresholds above usage is crossed, we read
5591 * only one element of the array here.
5593 for (; i
< t
->size
&& unlikely(t
->entries
[i
].threshold
<= usage
); i
++)
5594 eventfd_signal(t
->entries
[i
].eventfd
, 1);
5596 /* Update current_threshold */
5597 t
->current_threshold
= i
- 1;
5602 static void mem_cgroup_threshold(struct mem_cgroup
*memcg
)
5605 __mem_cgroup_threshold(memcg
, false);
5606 if (do_swap_account
)
5607 __mem_cgroup_threshold(memcg
, true);
5609 memcg
= parent_mem_cgroup(memcg
);
5613 static int compare_thresholds(const void *a
, const void *b
)
5615 const struct mem_cgroup_threshold
*_a
= a
;
5616 const struct mem_cgroup_threshold
*_b
= b
;
5618 return _a
->threshold
- _b
->threshold
;
5621 static int mem_cgroup_oom_notify_cb(struct mem_cgroup
*memcg
)
5623 struct mem_cgroup_eventfd_list
*ev
;
5625 list_for_each_entry(ev
, &memcg
->oom_notify
, list
)
5626 eventfd_signal(ev
->eventfd
, 1);
5630 static void mem_cgroup_oom_notify(struct mem_cgroup
*memcg
)
5632 struct mem_cgroup
*iter
;
5634 for_each_mem_cgroup_tree(iter
, memcg
)
5635 mem_cgroup_oom_notify_cb(iter
);
5638 static int mem_cgroup_usage_register_event(struct cgroup
*cgrp
,
5639 struct cftype
*cft
, struct eventfd_ctx
*eventfd
, const char *args
)
5641 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cgrp
);
5642 struct mem_cgroup_thresholds
*thresholds
;
5643 struct mem_cgroup_threshold_ary
*new;
5644 enum res_type type
= MEMFILE_TYPE(cft
->private);
5645 u64 threshold
, usage
;
5648 ret
= res_counter_memparse_write_strategy(args
, &threshold
);
5652 mutex_lock(&memcg
->thresholds_lock
);
5655 thresholds
= &memcg
->thresholds
;
5656 else if (type
== _MEMSWAP
)
5657 thresholds
= &memcg
->memsw_thresholds
;
5661 usage
= mem_cgroup_usage(memcg
, type
== _MEMSWAP
);
5663 /* Check if a threshold crossed before adding a new one */
5664 if (thresholds
->primary
)
5665 __mem_cgroup_threshold(memcg
, type
== _MEMSWAP
);
5667 size
= thresholds
->primary
? thresholds
->primary
->size
+ 1 : 1;
5669 /* Allocate memory for new array of thresholds */
5670 new = kmalloc(sizeof(*new) + size
* sizeof(struct mem_cgroup_threshold
),
5678 /* Copy thresholds (if any) to new array */
5679 if (thresholds
->primary
) {
5680 memcpy(new->entries
, thresholds
->primary
->entries
, (size
- 1) *
5681 sizeof(struct mem_cgroup_threshold
));
5684 /* Add new threshold */
5685 new->entries
[size
- 1].eventfd
= eventfd
;
5686 new->entries
[size
- 1].threshold
= threshold
;
5688 /* Sort thresholds. Registering of new threshold isn't time-critical */
5689 sort(new->entries
, size
, sizeof(struct mem_cgroup_threshold
),
5690 compare_thresholds
, NULL
);
5692 /* Find current threshold */
5693 new->current_threshold
= -1;
5694 for (i
= 0; i
< size
; i
++) {
5695 if (new->entries
[i
].threshold
<= usage
) {
5697 * new->current_threshold will not be used until
5698 * rcu_assign_pointer(), so it's safe to increment
5701 ++new->current_threshold
;
5706 /* Free old spare buffer and save old primary buffer as spare */
5707 kfree(thresholds
->spare
);
5708 thresholds
->spare
= thresholds
->primary
;
5710 rcu_assign_pointer(thresholds
->primary
, new);
5712 /* To be sure that nobody uses thresholds */
5716 mutex_unlock(&memcg
->thresholds_lock
);
5721 static void mem_cgroup_usage_unregister_event(struct cgroup
*cgrp
,
5722 struct cftype
*cft
, struct eventfd_ctx
*eventfd
)
5724 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cgrp
);
5725 struct mem_cgroup_thresholds
*thresholds
;
5726 struct mem_cgroup_threshold_ary
*new;
5727 enum res_type type
= MEMFILE_TYPE(cft
->private);
5731 mutex_lock(&memcg
->thresholds_lock
);
5733 thresholds
= &memcg
->thresholds
;
5734 else if (type
== _MEMSWAP
)
5735 thresholds
= &memcg
->memsw_thresholds
;
5739 if (!thresholds
->primary
)
5742 usage
= mem_cgroup_usage(memcg
, type
== _MEMSWAP
);
5744 /* Check if a threshold crossed before removing */
5745 __mem_cgroup_threshold(memcg
, type
== _MEMSWAP
);
5747 /* Calculate new number of threshold */
5749 for (i
= 0; i
< thresholds
->primary
->size
; i
++) {
5750 if (thresholds
->primary
->entries
[i
].eventfd
!= eventfd
)
5754 new = thresholds
->spare
;
5756 /* Set thresholds array to NULL if we don't have thresholds */
5765 /* Copy thresholds and find current threshold */
5766 new->current_threshold
= -1;
5767 for (i
= 0, j
= 0; i
< thresholds
->primary
->size
; i
++) {
5768 if (thresholds
->primary
->entries
[i
].eventfd
== eventfd
)
5771 new->entries
[j
] = thresholds
->primary
->entries
[i
];
5772 if (new->entries
[j
].threshold
<= usage
) {
5774 * new->current_threshold will not be used
5775 * until rcu_assign_pointer(), so it's safe to increment
5778 ++new->current_threshold
;
5784 /* Swap primary and spare array */
5785 thresholds
->spare
= thresholds
->primary
;
5786 /* If all events are unregistered, free the spare array */
5788 kfree(thresholds
->spare
);
5789 thresholds
->spare
= NULL
;
5792 rcu_assign_pointer(thresholds
->primary
, new);
5794 /* To be sure that nobody uses thresholds */
5797 mutex_unlock(&memcg
->thresholds_lock
);
5800 static int mem_cgroup_oom_register_event(struct cgroup
*cgrp
,
5801 struct cftype
*cft
, struct eventfd_ctx
*eventfd
, const char *args
)
5803 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cgrp
);
5804 struct mem_cgroup_eventfd_list
*event
;
5805 enum res_type type
= MEMFILE_TYPE(cft
->private);
5807 BUG_ON(type
!= _OOM_TYPE
);
5808 event
= kmalloc(sizeof(*event
), GFP_KERNEL
);
5812 spin_lock(&memcg_oom_lock
);
5814 event
->eventfd
= eventfd
;
5815 list_add(&event
->list
, &memcg
->oom_notify
);
5817 /* already in OOM ? */
5818 if (atomic_read(&memcg
->under_oom
))
5819 eventfd_signal(eventfd
, 1);
5820 spin_unlock(&memcg_oom_lock
);
5825 static void mem_cgroup_oom_unregister_event(struct cgroup
*cgrp
,
5826 struct cftype
*cft
, struct eventfd_ctx
*eventfd
)
5828 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cgrp
);
5829 struct mem_cgroup_eventfd_list
*ev
, *tmp
;
5830 enum res_type type
= MEMFILE_TYPE(cft
->private);
5832 BUG_ON(type
!= _OOM_TYPE
);
5834 spin_lock(&memcg_oom_lock
);
5836 list_for_each_entry_safe(ev
, tmp
, &memcg
->oom_notify
, list
) {
5837 if (ev
->eventfd
== eventfd
) {
5838 list_del(&ev
->list
);
5843 spin_unlock(&memcg_oom_lock
);
5846 static int mem_cgroup_oom_control_read(struct cgroup
*cgrp
,
5847 struct cftype
*cft
, struct cgroup_map_cb
*cb
)
5849 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cgrp
);
5851 cb
->fill(cb
, "oom_kill_disable", memcg
->oom_kill_disable
);
5853 if (atomic_read(&memcg
->under_oom
))
5854 cb
->fill(cb
, "under_oom", 1);
5856 cb
->fill(cb
, "under_oom", 0);
5860 static int mem_cgroup_oom_control_write(struct cgroup
*cgrp
,
5861 struct cftype
*cft
, u64 val
)
5863 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cgrp
);
5864 struct mem_cgroup
*parent
;
5866 /* cannot set to root cgroup and only 0 and 1 are allowed */
5867 if (!cgrp
->parent
|| !((val
== 0) || (val
== 1)))
5870 parent
= mem_cgroup_from_cont(cgrp
->parent
);
5872 mutex_lock(&memcg_create_mutex
);
5873 /* oom-kill-disable is a flag for subhierarchy. */
5874 if ((parent
->use_hierarchy
) || memcg_has_children(memcg
)) {
5875 mutex_unlock(&memcg_create_mutex
);
5878 memcg
->oom_kill_disable
= val
;
5880 memcg_oom_recover(memcg
);
5881 mutex_unlock(&memcg_create_mutex
);
5885 #ifdef CONFIG_MEMCG_KMEM
5886 static int memcg_init_kmem(struct mem_cgroup
*memcg
, struct cgroup_subsys
*ss
)
5890 memcg
->kmemcg_id
= -1;
5891 ret
= memcg_propagate_kmem(memcg
);
5895 return mem_cgroup_sockets_init(memcg
, ss
);
5898 static void memcg_destroy_kmem(struct mem_cgroup
*memcg
)
5900 mem_cgroup_sockets_destroy(memcg
);
5903 static void kmem_cgroup_css_offline(struct mem_cgroup
*memcg
)
5905 if (!memcg_kmem_is_active(memcg
))
5909 * kmem charges can outlive the cgroup. In the case of slab
5910 * pages, for instance, a page contain objects from various
5911 * processes. As we prevent from taking a reference for every
5912 * such allocation we have to be careful when doing uncharge
5913 * (see memcg_uncharge_kmem) and here during offlining.
5915 * The idea is that that only the _last_ uncharge which sees
5916 * the dead memcg will drop the last reference. An additional
5917 * reference is taken here before the group is marked dead
5918 * which is then paired with css_put during uncharge resp. here.
5920 * Although this might sound strange as this path is called from
5921 * css_offline() when the referencemight have dropped down to 0
5922 * and shouldn't be incremented anymore (css_tryget would fail)
5923 * we do not have other options because of the kmem allocations
5926 css_get(&memcg
->css
);
5928 memcg_kmem_mark_dead(memcg
);
5930 if (res_counter_read_u64(&memcg
->kmem
, RES_USAGE
) != 0)
5933 if (memcg_kmem_test_and_clear_dead(memcg
))
5934 css_put(&memcg
->css
);
5937 static int memcg_init_kmem(struct mem_cgroup
*memcg
, struct cgroup_subsys
*ss
)
5942 static void memcg_destroy_kmem(struct mem_cgroup
*memcg
)
5946 static void kmem_cgroup_css_offline(struct mem_cgroup
*memcg
)
5951 static struct cftype mem_cgroup_files
[] = {
5953 .name
= "usage_in_bytes",
5954 .private = MEMFILE_PRIVATE(_MEM
, RES_USAGE
),
5955 .read
= mem_cgroup_read
,
5956 .register_event
= mem_cgroup_usage_register_event
,
5957 .unregister_event
= mem_cgroup_usage_unregister_event
,
5960 .name
= "max_usage_in_bytes",
5961 .private = MEMFILE_PRIVATE(_MEM
, RES_MAX_USAGE
),
5962 .trigger
= mem_cgroup_reset
,
5963 .read
= mem_cgroup_read
,
5966 .name
= "limit_in_bytes",
5967 .private = MEMFILE_PRIVATE(_MEM
, RES_LIMIT
),
5968 .write_string
= mem_cgroup_write
,
5969 .read
= mem_cgroup_read
,
5972 .name
= "soft_limit_in_bytes",
5973 .private = MEMFILE_PRIVATE(_MEM
, RES_SOFT_LIMIT
),
5974 .write_string
= mem_cgroup_write
,
5975 .read
= mem_cgroup_read
,
5979 .private = MEMFILE_PRIVATE(_MEM
, RES_FAILCNT
),
5980 .trigger
= mem_cgroup_reset
,
5981 .read
= mem_cgroup_read
,
5985 .read_seq_string
= memcg_stat_show
,
5988 .name
= "force_empty",
5989 .trigger
= mem_cgroup_force_empty_write
,
5992 .name
= "use_hierarchy",
5993 .flags
= CFTYPE_INSANE
,
5994 .write_u64
= mem_cgroup_hierarchy_write
,
5995 .read_u64
= mem_cgroup_hierarchy_read
,
5998 .name
= "swappiness",
5999 .read_u64
= mem_cgroup_swappiness_read
,
6000 .write_u64
= mem_cgroup_swappiness_write
,
6003 .name
= "move_charge_at_immigrate",
6004 .read_u64
= mem_cgroup_move_charge_read
,
6005 .write_u64
= mem_cgroup_move_charge_write
,
6008 .name
= "oom_control",
6009 .read_map
= mem_cgroup_oom_control_read
,
6010 .write_u64
= mem_cgroup_oom_control_write
,
6011 .register_event
= mem_cgroup_oom_register_event
,
6012 .unregister_event
= mem_cgroup_oom_unregister_event
,
6013 .private = MEMFILE_PRIVATE(_OOM_TYPE
, OOM_CONTROL
),
6016 .name
= "pressure_level",
6017 .register_event
= vmpressure_register_event
,
6018 .unregister_event
= vmpressure_unregister_event
,
6022 .name
= "numa_stat",
6023 .read_seq_string
= memcg_numa_stat_show
,
6026 #ifdef CONFIG_MEMCG_KMEM
6028 .name
= "kmem.limit_in_bytes",
6029 .private = MEMFILE_PRIVATE(_KMEM
, RES_LIMIT
),
6030 .write_string
= mem_cgroup_write
,
6031 .read
= mem_cgroup_read
,
6034 .name
= "kmem.usage_in_bytes",
6035 .private = MEMFILE_PRIVATE(_KMEM
, RES_USAGE
),
6036 .read
= mem_cgroup_read
,
6039 .name
= "kmem.failcnt",
6040 .private = MEMFILE_PRIVATE(_KMEM
, RES_FAILCNT
),
6041 .trigger
= mem_cgroup_reset
,
6042 .read
= mem_cgroup_read
,
6045 .name
= "kmem.max_usage_in_bytes",
6046 .private = MEMFILE_PRIVATE(_KMEM
, RES_MAX_USAGE
),
6047 .trigger
= mem_cgroup_reset
,
6048 .read
= mem_cgroup_read
,
6050 #ifdef CONFIG_SLABINFO
6052 .name
= "kmem.slabinfo",
6053 .read_seq_string
= mem_cgroup_slabinfo_read
,
6057 { }, /* terminate */
6060 #ifdef CONFIG_MEMCG_SWAP
6061 static struct cftype memsw_cgroup_files
[] = {
6063 .name
= "memsw.usage_in_bytes",
6064 .private = MEMFILE_PRIVATE(_MEMSWAP
, RES_USAGE
),
6065 .read
= mem_cgroup_read
,
6066 .register_event
= mem_cgroup_usage_register_event
,
6067 .unregister_event
= mem_cgroup_usage_unregister_event
,
6070 .name
= "memsw.max_usage_in_bytes",
6071 .private = MEMFILE_PRIVATE(_MEMSWAP
, RES_MAX_USAGE
),
6072 .trigger
= mem_cgroup_reset
,
6073 .read
= mem_cgroup_read
,
6076 .name
= "memsw.limit_in_bytes",
6077 .private = MEMFILE_PRIVATE(_MEMSWAP
, RES_LIMIT
),
6078 .write_string
= mem_cgroup_write
,
6079 .read
= mem_cgroup_read
,
6082 .name
= "memsw.failcnt",
6083 .private = MEMFILE_PRIVATE(_MEMSWAP
, RES_FAILCNT
),
6084 .trigger
= mem_cgroup_reset
,
6085 .read
= mem_cgroup_read
,
6087 { }, /* terminate */
6090 static int alloc_mem_cgroup_per_zone_info(struct mem_cgroup
*memcg
, int node
)
6092 struct mem_cgroup_per_node
*pn
;
6093 struct mem_cgroup_per_zone
*mz
;
6094 int zone
, tmp
= node
;
6096 * This routine is called against possible nodes.
6097 * But it's BUG to call kmalloc() against offline node.
6099 * TODO: this routine can waste much memory for nodes which will
6100 * never be onlined. It's better to use memory hotplug callback
6103 if (!node_state(node
, N_NORMAL_MEMORY
))
6105 pn
= kzalloc_node(sizeof(*pn
), GFP_KERNEL
, tmp
);
6109 for (zone
= 0; zone
< MAX_NR_ZONES
; zone
++) {
6110 mz
= &pn
->zoneinfo
[zone
];
6111 lruvec_init(&mz
->lruvec
);
6112 mz
->usage_in_excess
= 0;
6113 mz
->on_tree
= false;
6116 memcg
->nodeinfo
[node
] = pn
;
6120 static void free_mem_cgroup_per_zone_info(struct mem_cgroup
*memcg
, int node
)
6122 kfree(memcg
->nodeinfo
[node
]);
6125 static struct mem_cgroup
*mem_cgroup_alloc(void)
6127 struct mem_cgroup
*memcg
;
6128 size_t size
= memcg_size();
6130 /* Can be very big if nr_node_ids is very big */
6131 if (size
< PAGE_SIZE
)
6132 memcg
= kzalloc(size
, GFP_KERNEL
);
6134 memcg
= vzalloc(size
);
6139 memcg
->stat
= alloc_percpu(struct mem_cgroup_stat_cpu
);
6142 spin_lock_init(&memcg
->pcp_counter_lock
);
6146 if (size
< PAGE_SIZE
)
6154 * At destroying mem_cgroup, references from swap_cgroup can remain.
6155 * (scanning all at force_empty is too costly...)
6157 * Instead of clearing all references at force_empty, we remember
6158 * the number of reference from swap_cgroup and free mem_cgroup when
6159 * it goes down to 0.
6161 * Removal of cgroup itself succeeds regardless of refs from swap.
6164 static void __mem_cgroup_free(struct mem_cgroup
*memcg
)
6167 size_t size
= memcg_size();
6169 mem_cgroup_remove_from_trees(memcg
);
6170 free_css_id(&mem_cgroup_subsys
, &memcg
->css
);
6173 free_mem_cgroup_per_zone_info(memcg
, node
);
6175 free_percpu(memcg
->stat
);
6178 * We need to make sure that (at least for now), the jump label
6179 * destruction code runs outside of the cgroup lock. This is because
6180 * get_online_cpus(), which is called from the static_branch update,
6181 * can't be called inside the cgroup_lock. cpusets are the ones
6182 * enforcing this dependency, so if they ever change, we might as well.
6184 * schedule_work() will guarantee this happens. Be careful if you need
6185 * to move this code around, and make sure it is outside
6188 disarm_static_keys(memcg
);
6189 if (size
< PAGE_SIZE
)
6196 * Returns the parent mem_cgroup in memcgroup hierarchy with hierarchy enabled.
6198 struct mem_cgroup
*parent_mem_cgroup(struct mem_cgroup
*memcg
)
6200 if (!memcg
->res
.parent
)
6202 return mem_cgroup_from_res_counter(memcg
->res
.parent
, res
);
6204 EXPORT_SYMBOL(parent_mem_cgroup
);
6206 static void __init
mem_cgroup_soft_limit_tree_init(void)
6208 struct mem_cgroup_tree_per_node
*rtpn
;
6209 struct mem_cgroup_tree_per_zone
*rtpz
;
6210 int tmp
, node
, zone
;
6212 for_each_node(node
) {
6214 if (!node_state(node
, N_NORMAL_MEMORY
))
6216 rtpn
= kzalloc_node(sizeof(*rtpn
), GFP_KERNEL
, tmp
);
6219 soft_limit_tree
.rb_tree_per_node
[node
] = rtpn
;
6221 for (zone
= 0; zone
< MAX_NR_ZONES
; zone
++) {
6222 rtpz
= &rtpn
->rb_tree_per_zone
[zone
];
6223 rtpz
->rb_root
= RB_ROOT
;
6224 spin_lock_init(&rtpz
->lock
);
6229 static struct cgroup_subsys_state
* __ref
6230 mem_cgroup_css_alloc(struct cgroup
*cont
)
6232 struct mem_cgroup
*memcg
;
6233 long error
= -ENOMEM
;
6236 memcg
= mem_cgroup_alloc();
6238 return ERR_PTR(error
);
6241 if (alloc_mem_cgroup_per_zone_info(memcg
, node
))
6245 if (cont
->parent
== NULL
) {
6246 root_mem_cgroup
= memcg
;
6247 res_counter_init(&memcg
->res
, NULL
);
6248 res_counter_init(&memcg
->memsw
, NULL
);
6249 res_counter_init(&memcg
->kmem
, NULL
);
6252 memcg
->last_scanned_node
= MAX_NUMNODES
;
6253 INIT_LIST_HEAD(&memcg
->oom_notify
);
6254 memcg
->move_charge_at_immigrate
= 0;
6255 mutex_init(&memcg
->thresholds_lock
);
6256 spin_lock_init(&memcg
->move_lock
);
6257 vmpressure_init(&memcg
->vmpressure
);
6262 __mem_cgroup_free(memcg
);
6263 return ERR_PTR(error
);
6267 mem_cgroup_css_online(struct cgroup
*cont
)
6269 struct mem_cgroup
*memcg
, *parent
;
6275 mutex_lock(&memcg_create_mutex
);
6276 memcg
= mem_cgroup_from_cont(cont
);
6277 parent
= mem_cgroup_from_cont(cont
->parent
);
6279 memcg
->use_hierarchy
= parent
->use_hierarchy
;
6280 memcg
->oom_kill_disable
= parent
->oom_kill_disable
;
6281 memcg
->swappiness
= mem_cgroup_swappiness(parent
);
6283 if (parent
->use_hierarchy
) {
6284 res_counter_init(&memcg
->res
, &parent
->res
);
6285 res_counter_init(&memcg
->memsw
, &parent
->memsw
);
6286 res_counter_init(&memcg
->kmem
, &parent
->kmem
);
6289 * No need to take a reference to the parent because cgroup
6290 * core guarantees its existence.
6293 res_counter_init(&memcg
->res
, NULL
);
6294 res_counter_init(&memcg
->memsw
, NULL
);
6295 res_counter_init(&memcg
->kmem
, NULL
);
6297 * Deeper hierachy with use_hierarchy == false doesn't make
6298 * much sense so let cgroup subsystem know about this
6299 * unfortunate state in our controller.
6301 if (parent
!= root_mem_cgroup
)
6302 mem_cgroup_subsys
.broken_hierarchy
= true;
6305 error
= memcg_init_kmem(memcg
, &mem_cgroup_subsys
);
6306 mutex_unlock(&memcg_create_mutex
);
6311 * Announce all parents that a group from their hierarchy is gone.
6313 static void mem_cgroup_invalidate_reclaim_iterators(struct mem_cgroup
*memcg
)
6315 struct mem_cgroup
*parent
= memcg
;
6317 while ((parent
= parent_mem_cgroup(parent
)))
6318 mem_cgroup_iter_invalidate(parent
);
6321 * if the root memcg is not hierarchical we have to check it
6324 if (!root_mem_cgroup
->use_hierarchy
)
6325 mem_cgroup_iter_invalidate(root_mem_cgroup
);
6328 static void mem_cgroup_css_offline(struct cgroup
*cont
)
6330 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cont
);
6332 kmem_cgroup_css_offline(memcg
);
6334 mem_cgroup_invalidate_reclaim_iterators(memcg
);
6335 mem_cgroup_reparent_charges(memcg
);
6336 mem_cgroup_destroy_all_caches(memcg
);
6339 static void mem_cgroup_css_free(struct cgroup
*cont
)
6341 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cont
);
6343 memcg_destroy_kmem(memcg
);
6344 __mem_cgroup_free(memcg
);
6348 /* Handlers for move charge at task migration. */
6349 #define PRECHARGE_COUNT_AT_ONCE 256
6350 static int mem_cgroup_do_precharge(unsigned long count
)
6353 int batch_count
= PRECHARGE_COUNT_AT_ONCE
;
6354 struct mem_cgroup
*memcg
= mc
.to
;
6356 if (mem_cgroup_is_root(memcg
)) {
6357 mc
.precharge
+= count
;
6358 /* we don't need css_get for root */
6361 /* try to charge at once */
6363 struct res_counter
*dummy
;
6365 * "memcg" cannot be under rmdir() because we've already checked
6366 * by cgroup_lock_live_cgroup() that it is not removed and we
6367 * are still under the same cgroup_mutex. So we can postpone
6370 if (res_counter_charge(&memcg
->res
, PAGE_SIZE
* count
, &dummy
))
6372 if (do_swap_account
&& res_counter_charge(&memcg
->memsw
,
6373 PAGE_SIZE
* count
, &dummy
)) {
6374 res_counter_uncharge(&memcg
->res
, PAGE_SIZE
* count
);
6377 mc
.precharge
+= count
;
6381 /* fall back to one by one charge */
6383 if (signal_pending(current
)) {
6387 if (!batch_count
--) {
6388 batch_count
= PRECHARGE_COUNT_AT_ONCE
;
6391 ret
= __mem_cgroup_try_charge(NULL
,
6392 GFP_KERNEL
, 1, &memcg
, false);
6394 /* mem_cgroup_clear_mc() will do uncharge later */
6402 * get_mctgt_type - get target type of moving charge
6403 * @vma: the vma the pte to be checked belongs
6404 * @addr: the address corresponding to the pte to be checked
6405 * @ptent: the pte to be checked
6406 * @target: the pointer the target page or swap ent will be stored(can be NULL)
6409 * 0(MC_TARGET_NONE): if the pte is not a target for move charge.
6410 * 1(MC_TARGET_PAGE): if the page corresponding to this pte is a target for
6411 * move charge. if @target is not NULL, the page is stored in target->page
6412 * with extra refcnt got(Callers should handle it).
6413 * 2(MC_TARGET_SWAP): if the swap entry corresponding to this pte is a
6414 * target for charge migration. if @target is not NULL, the entry is stored
6417 * Called with pte lock held.
6424 enum mc_target_type
{
6430 static struct page
*mc_handle_present_pte(struct vm_area_struct
*vma
,
6431 unsigned long addr
, pte_t ptent
)
6433 struct page
*page
= vm_normal_page(vma
, addr
, ptent
);
6435 if (!page
|| !page_mapped(page
))
6437 if (PageAnon(page
)) {
6438 /* we don't move shared anon */
6441 } else if (!move_file())
6442 /* we ignore mapcount for file pages */
6444 if (!get_page_unless_zero(page
))
6451 static struct page
*mc_handle_swap_pte(struct vm_area_struct
*vma
,
6452 unsigned long addr
, pte_t ptent
, swp_entry_t
*entry
)
6454 struct page
*page
= NULL
;
6455 swp_entry_t ent
= pte_to_swp_entry(ptent
);
6457 if (!move_anon() || non_swap_entry(ent
))
6460 * Because lookup_swap_cache() updates some statistics counter,
6461 * we call find_get_page() with swapper_space directly.
6463 page
= find_get_page(swap_address_space(ent
), ent
.val
);
6464 if (do_swap_account
)
6465 entry
->val
= ent
.val
;
6470 static struct page
*mc_handle_swap_pte(struct vm_area_struct
*vma
,
6471 unsigned long addr
, pte_t ptent
, swp_entry_t
*entry
)
6477 static struct page
*mc_handle_file_pte(struct vm_area_struct
*vma
,
6478 unsigned long addr
, pte_t ptent
, swp_entry_t
*entry
)
6480 struct page
*page
= NULL
;
6481 struct address_space
*mapping
;
6484 if (!vma
->vm_file
) /* anonymous vma */
6489 mapping
= vma
->vm_file
->f_mapping
;
6490 if (pte_none(ptent
))
6491 pgoff
= linear_page_index(vma
, addr
);
6492 else /* pte_file(ptent) is true */
6493 pgoff
= pte_to_pgoff(ptent
);
6495 /* page is moved even if it's not RSS of this task(page-faulted). */
6496 page
= find_get_page(mapping
, pgoff
);
6499 /* shmem/tmpfs may report page out on swap: account for that too. */
6500 if (radix_tree_exceptional_entry(page
)) {
6501 swp_entry_t swap
= radix_to_swp_entry(page
);
6502 if (do_swap_account
)
6504 page
= find_get_page(swap_address_space(swap
), swap
.val
);
6510 static enum mc_target_type
get_mctgt_type(struct vm_area_struct
*vma
,
6511 unsigned long addr
, pte_t ptent
, union mc_target
*target
)
6513 struct page
*page
= NULL
;
6514 struct page_cgroup
*pc
;
6515 enum mc_target_type ret
= MC_TARGET_NONE
;
6516 swp_entry_t ent
= { .val
= 0 };
6518 if (pte_present(ptent
))
6519 page
= mc_handle_present_pte(vma
, addr
, ptent
);
6520 else if (is_swap_pte(ptent
))
6521 page
= mc_handle_swap_pte(vma
, addr
, ptent
, &ent
);
6522 else if (pte_none(ptent
) || pte_file(ptent
))
6523 page
= mc_handle_file_pte(vma
, addr
, ptent
, &ent
);
6525 if (!page
&& !ent
.val
)
6528 pc
= lookup_page_cgroup(page
);
6530 * Do only loose check w/o page_cgroup lock.
6531 * mem_cgroup_move_account() checks the pc is valid or not under
6534 if (PageCgroupUsed(pc
) && pc
->mem_cgroup
== mc
.from
) {
6535 ret
= MC_TARGET_PAGE
;
6537 target
->page
= page
;
6539 if (!ret
|| !target
)
6542 /* There is a swap entry and a page doesn't exist or isn't charged */
6543 if (ent
.val
&& !ret
&&
6544 css_id(&mc
.from
->css
) == lookup_swap_cgroup_id(ent
)) {
6545 ret
= MC_TARGET_SWAP
;
6552 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
6554 * We don't consider swapping or file mapped pages because THP does not
6555 * support them for now.
6556 * Caller should make sure that pmd_trans_huge(pmd) is true.
6558 static enum mc_target_type
get_mctgt_type_thp(struct vm_area_struct
*vma
,
6559 unsigned long addr
, pmd_t pmd
, union mc_target
*target
)
6561 struct page
*page
= NULL
;
6562 struct page_cgroup
*pc
;
6563 enum mc_target_type ret
= MC_TARGET_NONE
;
6565 page
= pmd_page(pmd
);
6566 VM_BUG_ON(!page
|| !PageHead(page
));
6569 pc
= lookup_page_cgroup(page
);
6570 if (PageCgroupUsed(pc
) && pc
->mem_cgroup
== mc
.from
) {
6571 ret
= MC_TARGET_PAGE
;
6574 target
->page
= page
;
6580 static inline enum mc_target_type
get_mctgt_type_thp(struct vm_area_struct
*vma
,
6581 unsigned long addr
, pmd_t pmd
, union mc_target
*target
)
6583 return MC_TARGET_NONE
;
6587 static int mem_cgroup_count_precharge_pte_range(pmd_t
*pmd
,
6588 unsigned long addr
, unsigned long end
,
6589 struct mm_walk
*walk
)
6591 struct vm_area_struct
*vma
= walk
->private;
6595 if (pmd_trans_huge_lock(pmd
, vma
) == 1) {
6596 if (get_mctgt_type_thp(vma
, addr
, *pmd
, NULL
) == MC_TARGET_PAGE
)
6597 mc
.precharge
+= HPAGE_PMD_NR
;
6598 spin_unlock(&vma
->vm_mm
->page_table_lock
);
6602 if (pmd_trans_unstable(pmd
))
6604 pte
= pte_offset_map_lock(vma
->vm_mm
, pmd
, addr
, &ptl
);
6605 for (; addr
!= end
; pte
++, addr
+= PAGE_SIZE
)
6606 if (get_mctgt_type(vma
, addr
, *pte
, NULL
))
6607 mc
.precharge
++; /* increment precharge temporarily */
6608 pte_unmap_unlock(pte
- 1, ptl
);
6614 static unsigned long mem_cgroup_count_precharge(struct mm_struct
*mm
)
6616 unsigned long precharge
;
6617 struct vm_area_struct
*vma
;
6619 down_read(&mm
->mmap_sem
);
6620 for (vma
= mm
->mmap
; vma
; vma
= vma
->vm_next
) {
6621 struct mm_walk mem_cgroup_count_precharge_walk
= {
6622 .pmd_entry
= mem_cgroup_count_precharge_pte_range
,
6626 if (is_vm_hugetlb_page(vma
))
6628 walk_page_range(vma
->vm_start
, vma
->vm_end
,
6629 &mem_cgroup_count_precharge_walk
);
6631 up_read(&mm
->mmap_sem
);
6633 precharge
= mc
.precharge
;
6639 static int mem_cgroup_precharge_mc(struct mm_struct
*mm
)
6641 unsigned long precharge
= mem_cgroup_count_precharge(mm
);
6643 VM_BUG_ON(mc
.moving_task
);
6644 mc
.moving_task
= current
;
6645 return mem_cgroup_do_precharge(precharge
);
6648 /* cancels all extra charges on mc.from and mc.to, and wakes up all waiters. */
6649 static void __mem_cgroup_clear_mc(void)
6651 struct mem_cgroup
*from
= mc
.from
;
6652 struct mem_cgroup
*to
= mc
.to
;
6655 /* we must uncharge all the leftover precharges from mc.to */
6657 __mem_cgroup_cancel_charge(mc
.to
, mc
.precharge
);
6661 * we didn't uncharge from mc.from at mem_cgroup_move_account(), so
6662 * we must uncharge here.
6664 if (mc
.moved_charge
) {
6665 __mem_cgroup_cancel_charge(mc
.from
, mc
.moved_charge
);
6666 mc
.moved_charge
= 0;
6668 /* we must fixup refcnts and charges */
6669 if (mc
.moved_swap
) {
6670 /* uncharge swap account from the old cgroup */
6671 if (!mem_cgroup_is_root(mc
.from
))
6672 res_counter_uncharge(&mc
.from
->memsw
,
6673 PAGE_SIZE
* mc
.moved_swap
);
6675 for (i
= 0; i
< mc
.moved_swap
; i
++)
6676 css_put(&mc
.from
->css
);
6678 if (!mem_cgroup_is_root(mc
.to
)) {
6680 * we charged both to->res and to->memsw, so we should
6683 res_counter_uncharge(&mc
.to
->res
,
6684 PAGE_SIZE
* mc
.moved_swap
);
6686 /* we've already done css_get(mc.to) */
6689 memcg_oom_recover(from
);
6690 memcg_oom_recover(to
);
6691 wake_up_all(&mc
.waitq
);
6694 static void mem_cgroup_clear_mc(void)
6696 struct mem_cgroup
*from
= mc
.from
;
6699 * we must clear moving_task before waking up waiters at the end of
6702 mc
.moving_task
= NULL
;
6703 __mem_cgroup_clear_mc();
6704 spin_lock(&mc
.lock
);
6707 spin_unlock(&mc
.lock
);
6708 mem_cgroup_end_move(from
);
6711 static int mem_cgroup_can_attach(struct cgroup
*cgroup
,
6712 struct cgroup_taskset
*tset
)
6714 struct task_struct
*p
= cgroup_taskset_first(tset
);
6716 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cgroup
);
6717 unsigned long move_charge_at_immigrate
;
6720 * We are now commited to this value whatever it is. Changes in this
6721 * tunable will only affect upcoming migrations, not the current one.
6722 * So we need to save it, and keep it going.
6724 move_charge_at_immigrate
= memcg
->move_charge_at_immigrate
;
6725 if (move_charge_at_immigrate
) {
6726 struct mm_struct
*mm
;
6727 struct mem_cgroup
*from
= mem_cgroup_from_task(p
);
6729 VM_BUG_ON(from
== memcg
);
6731 mm
= get_task_mm(p
);
6734 /* We move charges only when we move a owner of the mm */
6735 if (mm
->owner
== p
) {
6738 VM_BUG_ON(mc
.precharge
);
6739 VM_BUG_ON(mc
.moved_charge
);
6740 VM_BUG_ON(mc
.moved_swap
);
6741 mem_cgroup_start_move(from
);
6742 spin_lock(&mc
.lock
);
6745 mc
.immigrate_flags
= move_charge_at_immigrate
;
6746 spin_unlock(&mc
.lock
);
6747 /* We set mc.moving_task later */
6749 ret
= mem_cgroup_precharge_mc(mm
);
6751 mem_cgroup_clear_mc();
6758 static void mem_cgroup_cancel_attach(struct cgroup
*cgroup
,
6759 struct cgroup_taskset
*tset
)
6761 mem_cgroup_clear_mc();
6764 static int mem_cgroup_move_charge_pte_range(pmd_t
*pmd
,
6765 unsigned long addr
, unsigned long end
,
6766 struct mm_walk
*walk
)
6769 struct vm_area_struct
*vma
= walk
->private;
6772 enum mc_target_type target_type
;
6773 union mc_target target
;
6775 struct page_cgroup
*pc
;
6778 * We don't take compound_lock() here but no race with splitting thp
6780 * - if pmd_trans_huge_lock() returns 1, the relevant thp is not
6781 * under splitting, which means there's no concurrent thp split,
6782 * - if another thread runs into split_huge_page() just after we
6783 * entered this if-block, the thread must wait for page table lock
6784 * to be unlocked in __split_huge_page_splitting(), where the main
6785 * part of thp split is not executed yet.
6787 if (pmd_trans_huge_lock(pmd
, vma
) == 1) {
6788 if (mc
.precharge
< HPAGE_PMD_NR
) {
6789 spin_unlock(&vma
->vm_mm
->page_table_lock
);
6792 target_type
= get_mctgt_type_thp(vma
, addr
, *pmd
, &target
);
6793 if (target_type
== MC_TARGET_PAGE
) {
6795 if (!isolate_lru_page(page
)) {
6796 pc
= lookup_page_cgroup(page
);
6797 if (!mem_cgroup_move_account(page
, HPAGE_PMD_NR
,
6798 pc
, mc
.from
, mc
.to
)) {
6799 mc
.precharge
-= HPAGE_PMD_NR
;
6800 mc
.moved_charge
+= HPAGE_PMD_NR
;
6802 putback_lru_page(page
);
6806 spin_unlock(&vma
->vm_mm
->page_table_lock
);
6810 if (pmd_trans_unstable(pmd
))
6813 pte
= pte_offset_map_lock(vma
->vm_mm
, pmd
, addr
, &ptl
);
6814 for (; addr
!= end
; addr
+= PAGE_SIZE
) {
6815 pte_t ptent
= *(pte
++);
6821 switch (get_mctgt_type(vma
, addr
, ptent
, &target
)) {
6822 case MC_TARGET_PAGE
:
6824 if (isolate_lru_page(page
))
6826 pc
= lookup_page_cgroup(page
);
6827 if (!mem_cgroup_move_account(page
, 1, pc
,
6830 /* we uncharge from mc.from later. */
6833 putback_lru_page(page
);
6834 put
: /* get_mctgt_type() gets the page */
6837 case MC_TARGET_SWAP
:
6839 if (!mem_cgroup_move_swap_account(ent
, mc
.from
, mc
.to
)) {
6841 /* we fixup refcnts and charges later. */
6849 pte_unmap_unlock(pte
- 1, ptl
);
6854 * We have consumed all precharges we got in can_attach().
6855 * We try charge one by one, but don't do any additional
6856 * charges to mc.to if we have failed in charge once in attach()
6859 ret
= mem_cgroup_do_precharge(1);
6867 static void mem_cgroup_move_charge(struct mm_struct
*mm
)
6869 struct vm_area_struct
*vma
;
6871 lru_add_drain_all();
6873 if (unlikely(!down_read_trylock(&mm
->mmap_sem
))) {
6875 * Someone who are holding the mmap_sem might be waiting in
6876 * waitq. So we cancel all extra charges, wake up all waiters,
6877 * and retry. Because we cancel precharges, we might not be able
6878 * to move enough charges, but moving charge is a best-effort
6879 * feature anyway, so it wouldn't be a big problem.
6881 __mem_cgroup_clear_mc();
6885 for (vma
= mm
->mmap
; vma
; vma
= vma
->vm_next
) {
6887 struct mm_walk mem_cgroup_move_charge_walk
= {
6888 .pmd_entry
= mem_cgroup_move_charge_pte_range
,
6892 if (is_vm_hugetlb_page(vma
))
6894 ret
= walk_page_range(vma
->vm_start
, vma
->vm_end
,
6895 &mem_cgroup_move_charge_walk
);
6898 * means we have consumed all precharges and failed in
6899 * doing additional charge. Just abandon here.
6903 up_read(&mm
->mmap_sem
);
6906 static void mem_cgroup_move_task(struct cgroup
*cont
,
6907 struct cgroup_taskset
*tset
)
6909 struct task_struct
*p
= cgroup_taskset_first(tset
);
6910 struct mm_struct
*mm
= get_task_mm(p
);
6914 mem_cgroup_move_charge(mm
);
6918 mem_cgroup_clear_mc();
6920 #else /* !CONFIG_MMU */
6921 static int mem_cgroup_can_attach(struct cgroup
*cgroup
,
6922 struct cgroup_taskset
*tset
)
6926 static void mem_cgroup_cancel_attach(struct cgroup
*cgroup
,
6927 struct cgroup_taskset
*tset
)
6930 static void mem_cgroup_move_task(struct cgroup
*cont
,
6931 struct cgroup_taskset
*tset
)
6937 * Cgroup retains root cgroups across [un]mount cycles making it necessary
6938 * to verify sane_behavior flag on each mount attempt.
6940 static void mem_cgroup_bind(struct cgroup
*root
)
6943 * use_hierarchy is forced with sane_behavior. cgroup core
6944 * guarantees that @root doesn't have any children, so turning it
6945 * on for the root memcg is enough.
6947 if (cgroup_sane_behavior(root
))
6948 mem_cgroup_from_cont(root
)->use_hierarchy
= true;
6951 struct cgroup_subsys mem_cgroup_subsys
= {
6953 .subsys_id
= mem_cgroup_subsys_id
,
6954 .css_alloc
= mem_cgroup_css_alloc
,
6955 .css_online
= mem_cgroup_css_online
,
6956 .css_offline
= mem_cgroup_css_offline
,
6957 .css_free
= mem_cgroup_css_free
,
6958 .can_attach
= mem_cgroup_can_attach
,
6959 .cancel_attach
= mem_cgroup_cancel_attach
,
6960 .attach
= mem_cgroup_move_task
,
6961 .bind
= mem_cgroup_bind
,
6962 .base_cftypes
= mem_cgroup_files
,
6967 #ifdef CONFIG_MEMCG_SWAP
6968 static int __init
enable_swap_account(char *s
)
6970 /* consider enabled if no parameter or 1 is given */
6971 if (!strcmp(s
, "1"))
6972 really_do_swap_account
= 1;
6973 else if (!strcmp(s
, "0"))
6974 really_do_swap_account
= 0;
6977 __setup("swapaccount=", enable_swap_account
);
6979 static void __init
memsw_file_init(void)
6981 WARN_ON(cgroup_add_cftypes(&mem_cgroup_subsys
, memsw_cgroup_files
));
6984 static void __init
enable_swap_cgroup(void)
6986 if (!mem_cgroup_disabled() && really_do_swap_account
) {
6987 do_swap_account
= 1;
6993 static void __init
enable_swap_cgroup(void)
6999 * subsys_initcall() for memory controller.
7001 * Some parts like hotcpu_notifier() have to be initialized from this context
7002 * because of lock dependencies (cgroup_lock -> cpu hotplug) but basically
7003 * everything that doesn't depend on a specific mem_cgroup structure should
7004 * be initialized from here.
7006 static int __init
mem_cgroup_init(void)
7008 hotcpu_notifier(memcg_cpu_hotplug_callback
, 0);
7009 enable_swap_cgroup();
7010 mem_cgroup_soft_limit_tree_init();
7014 subsys_initcall(mem_cgroup_init
);