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
);
486 struct mem_cgroup
*mem_cgroup_from_css(struct cgroup_subsys_state
*s
)
488 return s
? container_of(s
, struct mem_cgroup
, css
) : NULL
;
491 /* Some nice accessors for the vmpressure. */
492 struct vmpressure
*memcg_to_vmpressure(struct mem_cgroup
*memcg
)
495 memcg
= root_mem_cgroup
;
496 return &memcg
->vmpressure
;
499 struct cgroup_subsys_state
*vmpressure_to_css(struct vmpressure
*vmpr
)
501 return &container_of(vmpr
, struct mem_cgroup
, vmpressure
)->css
;
504 struct vmpressure
*css_to_vmpressure(struct cgroup_subsys_state
*css
)
506 return &mem_cgroup_from_css(css
)->vmpressure
;
509 static inline bool mem_cgroup_is_root(struct mem_cgroup
*memcg
)
511 return (memcg
== root_mem_cgroup
);
514 /* Writing them here to avoid exposing memcg's inner layout */
515 #if defined(CONFIG_INET) && defined(CONFIG_MEMCG_KMEM)
517 void sock_update_memcg(struct sock
*sk
)
519 if (mem_cgroup_sockets_enabled
) {
520 struct mem_cgroup
*memcg
;
521 struct cg_proto
*cg_proto
;
523 BUG_ON(!sk
->sk_prot
->proto_cgroup
);
525 /* Socket cloning can throw us here with sk_cgrp already
526 * filled. It won't however, necessarily happen from
527 * process context. So the test for root memcg given
528 * the current task's memcg won't help us in this case.
530 * Respecting the original socket's memcg is a better
531 * decision in this case.
534 BUG_ON(mem_cgroup_is_root(sk
->sk_cgrp
->memcg
));
535 css_get(&sk
->sk_cgrp
->memcg
->css
);
540 memcg
= mem_cgroup_from_task(current
);
541 cg_proto
= sk
->sk_prot
->proto_cgroup(memcg
);
542 if (!mem_cgroup_is_root(memcg
) &&
543 memcg_proto_active(cg_proto
) && css_tryget(&memcg
->css
)) {
544 sk
->sk_cgrp
= cg_proto
;
549 EXPORT_SYMBOL(sock_update_memcg
);
551 void sock_release_memcg(struct sock
*sk
)
553 if (mem_cgroup_sockets_enabled
&& sk
->sk_cgrp
) {
554 struct mem_cgroup
*memcg
;
555 WARN_ON(!sk
->sk_cgrp
->memcg
);
556 memcg
= sk
->sk_cgrp
->memcg
;
557 css_put(&sk
->sk_cgrp
->memcg
->css
);
561 struct cg_proto
*tcp_proto_cgroup(struct mem_cgroup
*memcg
)
563 if (!memcg
|| mem_cgroup_is_root(memcg
))
566 return &memcg
->tcp_mem
.cg_proto
;
568 EXPORT_SYMBOL(tcp_proto_cgroup
);
570 static void disarm_sock_keys(struct mem_cgroup
*memcg
)
572 if (!memcg_proto_activated(&memcg
->tcp_mem
.cg_proto
))
574 static_key_slow_dec(&memcg_socket_limit_enabled
);
577 static void disarm_sock_keys(struct mem_cgroup
*memcg
)
582 #ifdef CONFIG_MEMCG_KMEM
584 * This will be the memcg's index in each cache's ->memcg_params->memcg_caches.
585 * There are two main reasons for not using the css_id for this:
586 * 1) this works better in sparse environments, where we have a lot of memcgs,
587 * but only a few kmem-limited. Or also, if we have, for instance, 200
588 * memcgs, and none but the 200th is kmem-limited, we'd have to have a
589 * 200 entry array for that.
591 * 2) In order not to violate the cgroup API, we would like to do all memory
592 * allocation in ->create(). At that point, we haven't yet allocated the
593 * css_id. Having a separate index prevents us from messing with the cgroup
596 * The current size of the caches array is stored in
597 * memcg_limited_groups_array_size. It will double each time we have to
600 static DEFINE_IDA(kmem_limited_groups
);
601 int memcg_limited_groups_array_size
;
604 * MIN_SIZE is different than 1, because we would like to avoid going through
605 * the alloc/free process all the time. In a small machine, 4 kmem-limited
606 * cgroups is a reasonable guess. In the future, it could be a parameter or
607 * tunable, but that is strictly not necessary.
609 * MAX_SIZE should be as large as the number of css_ids. Ideally, we could get
610 * this constant directly from cgroup, but it is understandable that this is
611 * better kept as an internal representation in cgroup.c. In any case, the
612 * css_id space is not getting any smaller, and we don't have to necessarily
613 * increase ours as well if it increases.
615 #define MEMCG_CACHES_MIN_SIZE 4
616 #define MEMCG_CACHES_MAX_SIZE 65535
619 * A lot of the calls to the cache allocation functions are expected to be
620 * inlined by the compiler. Since the calls to memcg_kmem_get_cache are
621 * conditional to this static branch, we'll have to allow modules that does
622 * kmem_cache_alloc and the such to see this symbol as well
624 struct static_key memcg_kmem_enabled_key
;
625 EXPORT_SYMBOL(memcg_kmem_enabled_key
);
627 static void disarm_kmem_keys(struct mem_cgroup
*memcg
)
629 if (memcg_kmem_is_active(memcg
)) {
630 static_key_slow_dec(&memcg_kmem_enabled_key
);
631 ida_simple_remove(&kmem_limited_groups
, memcg
->kmemcg_id
);
634 * This check can't live in kmem destruction function,
635 * since the charges will outlive the cgroup
637 WARN_ON(res_counter_read_u64(&memcg
->kmem
, RES_USAGE
) != 0);
640 static void disarm_kmem_keys(struct mem_cgroup
*memcg
)
643 #endif /* CONFIG_MEMCG_KMEM */
645 static void disarm_static_keys(struct mem_cgroup
*memcg
)
647 disarm_sock_keys(memcg
);
648 disarm_kmem_keys(memcg
);
651 static void drain_all_stock_async(struct mem_cgroup
*memcg
);
653 static struct mem_cgroup_per_zone
*
654 mem_cgroup_zoneinfo(struct mem_cgroup
*memcg
, int nid
, int zid
)
656 VM_BUG_ON((unsigned)nid
>= nr_node_ids
);
657 return &memcg
->nodeinfo
[nid
]->zoneinfo
[zid
];
660 struct cgroup_subsys_state
*mem_cgroup_css(struct mem_cgroup
*memcg
)
665 static struct mem_cgroup_per_zone
*
666 page_cgroup_zoneinfo(struct mem_cgroup
*memcg
, struct page
*page
)
668 int nid
= page_to_nid(page
);
669 int zid
= page_zonenum(page
);
671 return mem_cgroup_zoneinfo(memcg
, nid
, zid
);
674 static struct mem_cgroup_tree_per_zone
*
675 soft_limit_tree_node_zone(int nid
, int zid
)
677 return &soft_limit_tree
.rb_tree_per_node
[nid
]->rb_tree_per_zone
[zid
];
680 static struct mem_cgroup_tree_per_zone
*
681 soft_limit_tree_from_page(struct page
*page
)
683 int nid
= page_to_nid(page
);
684 int zid
= page_zonenum(page
);
686 return &soft_limit_tree
.rb_tree_per_node
[nid
]->rb_tree_per_zone
[zid
];
690 __mem_cgroup_insert_exceeded(struct mem_cgroup
*memcg
,
691 struct mem_cgroup_per_zone
*mz
,
692 struct mem_cgroup_tree_per_zone
*mctz
,
693 unsigned long long new_usage_in_excess
)
695 struct rb_node
**p
= &mctz
->rb_root
.rb_node
;
696 struct rb_node
*parent
= NULL
;
697 struct mem_cgroup_per_zone
*mz_node
;
702 mz
->usage_in_excess
= new_usage_in_excess
;
703 if (!mz
->usage_in_excess
)
707 mz_node
= rb_entry(parent
, struct mem_cgroup_per_zone
,
709 if (mz
->usage_in_excess
< mz_node
->usage_in_excess
)
712 * We can't avoid mem cgroups that are over their soft
713 * limit by the same amount
715 else if (mz
->usage_in_excess
>= mz_node
->usage_in_excess
)
718 rb_link_node(&mz
->tree_node
, parent
, p
);
719 rb_insert_color(&mz
->tree_node
, &mctz
->rb_root
);
724 __mem_cgroup_remove_exceeded(struct mem_cgroup
*memcg
,
725 struct mem_cgroup_per_zone
*mz
,
726 struct mem_cgroup_tree_per_zone
*mctz
)
730 rb_erase(&mz
->tree_node
, &mctz
->rb_root
);
735 mem_cgroup_remove_exceeded(struct mem_cgroup
*memcg
,
736 struct mem_cgroup_per_zone
*mz
,
737 struct mem_cgroup_tree_per_zone
*mctz
)
739 spin_lock(&mctz
->lock
);
740 __mem_cgroup_remove_exceeded(memcg
, mz
, mctz
);
741 spin_unlock(&mctz
->lock
);
745 static void mem_cgroup_update_tree(struct mem_cgroup
*memcg
, struct page
*page
)
747 unsigned long long excess
;
748 struct mem_cgroup_per_zone
*mz
;
749 struct mem_cgroup_tree_per_zone
*mctz
;
750 int nid
= page_to_nid(page
);
751 int zid
= page_zonenum(page
);
752 mctz
= soft_limit_tree_from_page(page
);
755 * Necessary to update all ancestors when hierarchy is used.
756 * because their event counter is not touched.
758 for (; memcg
; memcg
= parent_mem_cgroup(memcg
)) {
759 mz
= mem_cgroup_zoneinfo(memcg
, nid
, zid
);
760 excess
= res_counter_soft_limit_excess(&memcg
->res
);
762 * We have to update the tree if mz is on RB-tree or
763 * mem is over its softlimit.
765 if (excess
|| mz
->on_tree
) {
766 spin_lock(&mctz
->lock
);
767 /* if on-tree, remove it */
769 __mem_cgroup_remove_exceeded(memcg
, mz
, mctz
);
771 * Insert again. mz->usage_in_excess will be updated.
772 * If excess is 0, no tree ops.
774 __mem_cgroup_insert_exceeded(memcg
, mz
, mctz
, excess
);
775 spin_unlock(&mctz
->lock
);
780 static void mem_cgroup_remove_from_trees(struct mem_cgroup
*memcg
)
783 struct mem_cgroup_per_zone
*mz
;
784 struct mem_cgroup_tree_per_zone
*mctz
;
786 for_each_node(node
) {
787 for (zone
= 0; zone
< MAX_NR_ZONES
; zone
++) {
788 mz
= mem_cgroup_zoneinfo(memcg
, node
, zone
);
789 mctz
= soft_limit_tree_node_zone(node
, zone
);
790 mem_cgroup_remove_exceeded(memcg
, mz
, mctz
);
795 static struct mem_cgroup_per_zone
*
796 __mem_cgroup_largest_soft_limit_node(struct mem_cgroup_tree_per_zone
*mctz
)
798 struct rb_node
*rightmost
= NULL
;
799 struct mem_cgroup_per_zone
*mz
;
803 rightmost
= rb_last(&mctz
->rb_root
);
805 goto done
; /* Nothing to reclaim from */
807 mz
= rb_entry(rightmost
, struct mem_cgroup_per_zone
, tree_node
);
809 * Remove the node now but someone else can add it back,
810 * we will to add it back at the end of reclaim to its correct
811 * position in the tree.
813 __mem_cgroup_remove_exceeded(mz
->memcg
, mz
, mctz
);
814 if (!res_counter_soft_limit_excess(&mz
->memcg
->res
) ||
815 !css_tryget(&mz
->memcg
->css
))
821 static struct mem_cgroup_per_zone
*
822 mem_cgroup_largest_soft_limit_node(struct mem_cgroup_tree_per_zone
*mctz
)
824 struct mem_cgroup_per_zone
*mz
;
826 spin_lock(&mctz
->lock
);
827 mz
= __mem_cgroup_largest_soft_limit_node(mctz
);
828 spin_unlock(&mctz
->lock
);
833 * Implementation Note: reading percpu statistics for memcg.
835 * Both of vmstat[] and percpu_counter has threshold and do periodic
836 * synchronization to implement "quick" read. There are trade-off between
837 * reading cost and precision of value. Then, we may have a chance to implement
838 * a periodic synchronizion of counter in memcg's counter.
840 * But this _read() function is used for user interface now. The user accounts
841 * memory usage by memory cgroup and he _always_ requires exact value because
842 * he accounts memory. Even if we provide quick-and-fuzzy read, we always
843 * have to visit all online cpus and make sum. So, for now, unnecessary
844 * synchronization is not implemented. (just implemented for cpu hotplug)
846 * If there are kernel internal actions which can make use of some not-exact
847 * value, and reading all cpu value can be performance bottleneck in some
848 * common workload, threashold and synchonization as vmstat[] should be
851 static long mem_cgroup_read_stat(struct mem_cgroup
*memcg
,
852 enum mem_cgroup_stat_index idx
)
858 for_each_online_cpu(cpu
)
859 val
+= per_cpu(memcg
->stat
->count
[idx
], cpu
);
860 #ifdef CONFIG_HOTPLUG_CPU
861 spin_lock(&memcg
->pcp_counter_lock
);
862 val
+= memcg
->nocpu_base
.count
[idx
];
863 spin_unlock(&memcg
->pcp_counter_lock
);
869 static void mem_cgroup_swap_statistics(struct mem_cgroup
*memcg
,
872 int val
= (charge
) ? 1 : -1;
873 this_cpu_add(memcg
->stat
->count
[MEM_CGROUP_STAT_SWAP
], val
);
876 static unsigned long mem_cgroup_read_events(struct mem_cgroup
*memcg
,
877 enum mem_cgroup_events_index idx
)
879 unsigned long val
= 0;
882 for_each_online_cpu(cpu
)
883 val
+= per_cpu(memcg
->stat
->events
[idx
], cpu
);
884 #ifdef CONFIG_HOTPLUG_CPU
885 spin_lock(&memcg
->pcp_counter_lock
);
886 val
+= memcg
->nocpu_base
.events
[idx
];
887 spin_unlock(&memcg
->pcp_counter_lock
);
892 static void mem_cgroup_charge_statistics(struct mem_cgroup
*memcg
,
894 bool anon
, int nr_pages
)
899 * Here, RSS means 'mapped anon' and anon's SwapCache. Shmem/tmpfs is
900 * counted as CACHE even if it's on ANON LRU.
903 __this_cpu_add(memcg
->stat
->count
[MEM_CGROUP_STAT_RSS
],
906 __this_cpu_add(memcg
->stat
->count
[MEM_CGROUP_STAT_CACHE
],
909 if (PageTransHuge(page
))
910 __this_cpu_add(memcg
->stat
->count
[MEM_CGROUP_STAT_RSS_HUGE
],
913 /* pagein of a big page is an event. So, ignore page size */
915 __this_cpu_inc(memcg
->stat
->events
[MEM_CGROUP_EVENTS_PGPGIN
]);
917 __this_cpu_inc(memcg
->stat
->events
[MEM_CGROUP_EVENTS_PGPGOUT
]);
918 nr_pages
= -nr_pages
; /* for event */
921 __this_cpu_add(memcg
->stat
->nr_page_events
, nr_pages
);
927 mem_cgroup_get_lru_size(struct lruvec
*lruvec
, enum lru_list lru
)
929 struct mem_cgroup_per_zone
*mz
;
931 mz
= container_of(lruvec
, struct mem_cgroup_per_zone
, lruvec
);
932 return mz
->lru_size
[lru
];
936 mem_cgroup_zone_nr_lru_pages(struct mem_cgroup
*memcg
, int nid
, int zid
,
937 unsigned int lru_mask
)
939 struct mem_cgroup_per_zone
*mz
;
941 unsigned long ret
= 0;
943 mz
= mem_cgroup_zoneinfo(memcg
, nid
, zid
);
946 if (BIT(lru
) & lru_mask
)
947 ret
+= mz
->lru_size
[lru
];
953 mem_cgroup_node_nr_lru_pages(struct mem_cgroup
*memcg
,
954 int nid
, unsigned int lru_mask
)
959 for (zid
= 0; zid
< MAX_NR_ZONES
; zid
++)
960 total
+= mem_cgroup_zone_nr_lru_pages(memcg
,
966 static unsigned long mem_cgroup_nr_lru_pages(struct mem_cgroup
*memcg
,
967 unsigned int lru_mask
)
972 for_each_node_state(nid
, N_MEMORY
)
973 total
+= mem_cgroup_node_nr_lru_pages(memcg
, nid
, lru_mask
);
977 static bool mem_cgroup_event_ratelimit(struct mem_cgroup
*memcg
,
978 enum mem_cgroup_events_target target
)
980 unsigned long val
, next
;
982 val
= __this_cpu_read(memcg
->stat
->nr_page_events
);
983 next
= __this_cpu_read(memcg
->stat
->targets
[target
]);
984 /* from time_after() in jiffies.h */
985 if ((long)next
- (long)val
< 0) {
987 case MEM_CGROUP_TARGET_THRESH
:
988 next
= val
+ THRESHOLDS_EVENTS_TARGET
;
990 case MEM_CGROUP_TARGET_SOFTLIMIT
:
991 next
= val
+ SOFTLIMIT_EVENTS_TARGET
;
993 case MEM_CGROUP_TARGET_NUMAINFO
:
994 next
= val
+ NUMAINFO_EVENTS_TARGET
;
999 __this_cpu_write(memcg
->stat
->targets
[target
], next
);
1006 * Check events in order.
1009 static void memcg_check_events(struct mem_cgroup
*memcg
, struct page
*page
)
1012 /* threshold event is triggered in finer grain than soft limit */
1013 if (unlikely(mem_cgroup_event_ratelimit(memcg
,
1014 MEM_CGROUP_TARGET_THRESH
))) {
1016 bool do_numainfo __maybe_unused
;
1018 do_softlimit
= mem_cgroup_event_ratelimit(memcg
,
1019 MEM_CGROUP_TARGET_SOFTLIMIT
);
1020 #if MAX_NUMNODES > 1
1021 do_numainfo
= mem_cgroup_event_ratelimit(memcg
,
1022 MEM_CGROUP_TARGET_NUMAINFO
);
1026 mem_cgroup_threshold(memcg
);
1027 if (unlikely(do_softlimit
))
1028 mem_cgroup_update_tree(memcg
, page
);
1029 #if MAX_NUMNODES > 1
1030 if (unlikely(do_numainfo
))
1031 atomic_inc(&memcg
->numainfo_events
);
1037 struct mem_cgroup
*mem_cgroup_from_task(struct task_struct
*p
)
1040 * mm_update_next_owner() may clear mm->owner to NULL
1041 * if it races with swapoff, page migration, etc.
1042 * So this can be called with p == NULL.
1047 return mem_cgroup_from_css(task_css(p
, mem_cgroup_subsys_id
));
1050 struct mem_cgroup
*try_get_mem_cgroup_from_mm(struct mm_struct
*mm
)
1052 struct mem_cgroup
*memcg
= NULL
;
1057 * Because we have no locks, mm->owner's may be being moved to other
1058 * cgroup. We use css_tryget() here even if this looks
1059 * pessimistic (rather than adding locks here).
1063 memcg
= mem_cgroup_from_task(rcu_dereference(mm
->owner
));
1064 if (unlikely(!memcg
))
1066 } while (!css_tryget(&memcg
->css
));
1072 * Returns a next (in a pre-order walk) alive memcg (with elevated css
1073 * ref. count) or NULL if the whole root's subtree has been visited.
1075 * helper function to be used by mem_cgroup_iter
1077 static struct mem_cgroup
*__mem_cgroup_iter_next(struct mem_cgroup
*root
,
1078 struct mem_cgroup
*last_visited
)
1080 struct cgroup_subsys_state
*prev_css
, *next_css
;
1082 prev_css
= last_visited
? &last_visited
->css
: NULL
;
1084 next_css
= css_next_descendant_pre(prev_css
, &root
->css
);
1087 * Even if we found a group we have to make sure it is
1088 * alive. css && !memcg means that the groups should be
1089 * skipped and we should continue the tree walk.
1090 * last_visited css is safe to use because it is
1091 * protected by css_get and the tree walk is rcu safe.
1094 struct mem_cgroup
*mem
= mem_cgroup_from_css(next_css
);
1096 if (css_tryget(&mem
->css
))
1099 prev_css
= next_css
;
1107 static void mem_cgroup_iter_invalidate(struct mem_cgroup
*root
)
1110 * When a group in the hierarchy below root is destroyed, the
1111 * hierarchy iterator can no longer be trusted since it might
1112 * have pointed to the destroyed group. Invalidate it.
1114 atomic_inc(&root
->dead_count
);
1117 static struct mem_cgroup
*
1118 mem_cgroup_iter_load(struct mem_cgroup_reclaim_iter
*iter
,
1119 struct mem_cgroup
*root
,
1122 struct mem_cgroup
*position
= NULL
;
1124 * A cgroup destruction happens in two stages: offlining and
1125 * release. They are separated by a RCU grace period.
1127 * If the iterator is valid, we may still race with an
1128 * offlining. The RCU lock ensures the object won't be
1129 * released, tryget will fail if we lost the race.
1131 *sequence
= atomic_read(&root
->dead_count
);
1132 if (iter
->last_dead_count
== *sequence
) {
1134 position
= iter
->last_visited
;
1135 if (position
&& !css_tryget(&position
->css
))
1141 static void mem_cgroup_iter_update(struct mem_cgroup_reclaim_iter
*iter
,
1142 struct mem_cgroup
*last_visited
,
1143 struct mem_cgroup
*new_position
,
1147 css_put(&last_visited
->css
);
1149 * We store the sequence count from the time @last_visited was
1150 * loaded successfully instead of rereading it here so that we
1151 * don't lose destruction events in between. We could have
1152 * raced with the destruction of @new_position after all.
1154 iter
->last_visited
= new_position
;
1156 iter
->last_dead_count
= sequence
;
1160 * mem_cgroup_iter - iterate over memory cgroup hierarchy
1161 * @root: hierarchy root
1162 * @prev: previously returned memcg, NULL on first invocation
1163 * @reclaim: cookie for shared reclaim walks, NULL for full walks
1165 * Returns references to children of the hierarchy below @root, or
1166 * @root itself, or %NULL after a full round-trip.
1168 * Caller must pass the return value in @prev on subsequent
1169 * invocations for reference counting, or use mem_cgroup_iter_break()
1170 * to cancel a hierarchy walk before the round-trip is complete.
1172 * Reclaimers can specify a zone and a priority level in @reclaim to
1173 * divide up the memcgs in the hierarchy among all concurrent
1174 * reclaimers operating on the same zone and priority.
1176 struct mem_cgroup
*mem_cgroup_iter(struct mem_cgroup
*root
,
1177 struct mem_cgroup
*prev
,
1178 struct mem_cgroup_reclaim_cookie
*reclaim
)
1180 struct mem_cgroup
*memcg
= NULL
;
1181 struct mem_cgroup
*last_visited
= NULL
;
1183 if (mem_cgroup_disabled())
1187 root
= root_mem_cgroup
;
1189 if (prev
&& !reclaim
)
1190 last_visited
= prev
;
1192 if (!root
->use_hierarchy
&& root
!= root_mem_cgroup
) {
1200 struct mem_cgroup_reclaim_iter
*uninitialized_var(iter
);
1201 int uninitialized_var(seq
);
1204 int nid
= zone_to_nid(reclaim
->zone
);
1205 int zid
= zone_idx(reclaim
->zone
);
1206 struct mem_cgroup_per_zone
*mz
;
1208 mz
= mem_cgroup_zoneinfo(root
, nid
, zid
);
1209 iter
= &mz
->reclaim_iter
[reclaim
->priority
];
1210 if (prev
&& reclaim
->generation
!= iter
->generation
) {
1211 iter
->last_visited
= NULL
;
1215 last_visited
= mem_cgroup_iter_load(iter
, root
, &seq
);
1218 memcg
= __mem_cgroup_iter_next(root
, last_visited
);
1221 mem_cgroup_iter_update(iter
, last_visited
, memcg
, seq
);
1225 else if (!prev
&& memcg
)
1226 reclaim
->generation
= iter
->generation
;
1235 if (prev
&& prev
!= root
)
1236 css_put(&prev
->css
);
1242 * mem_cgroup_iter_break - abort a hierarchy walk prematurely
1243 * @root: hierarchy root
1244 * @prev: last visited hierarchy member as returned by mem_cgroup_iter()
1246 void mem_cgroup_iter_break(struct mem_cgroup
*root
,
1247 struct mem_cgroup
*prev
)
1250 root
= root_mem_cgroup
;
1251 if (prev
&& prev
!= root
)
1252 css_put(&prev
->css
);
1256 * Iteration constructs for visiting all cgroups (under a tree). If
1257 * loops are exited prematurely (break), mem_cgroup_iter_break() must
1258 * be used for reference counting.
1260 #define for_each_mem_cgroup_tree(iter, root) \
1261 for (iter = mem_cgroup_iter(root, NULL, NULL); \
1263 iter = mem_cgroup_iter(root, iter, NULL))
1265 #define for_each_mem_cgroup(iter) \
1266 for (iter = mem_cgroup_iter(NULL, NULL, NULL); \
1268 iter = mem_cgroup_iter(NULL, iter, NULL))
1270 void __mem_cgroup_count_vm_event(struct mm_struct
*mm
, enum vm_event_item idx
)
1272 struct mem_cgroup
*memcg
;
1275 memcg
= mem_cgroup_from_task(rcu_dereference(mm
->owner
));
1276 if (unlikely(!memcg
))
1281 this_cpu_inc(memcg
->stat
->events
[MEM_CGROUP_EVENTS_PGFAULT
]);
1284 this_cpu_inc(memcg
->stat
->events
[MEM_CGROUP_EVENTS_PGMAJFAULT
]);
1292 EXPORT_SYMBOL(__mem_cgroup_count_vm_event
);
1295 * mem_cgroup_zone_lruvec - get the lru list vector for a zone and memcg
1296 * @zone: zone of the wanted lruvec
1297 * @memcg: memcg of the wanted lruvec
1299 * Returns the lru list vector holding pages for the given @zone and
1300 * @mem. This can be the global zone lruvec, if the memory controller
1303 struct lruvec
*mem_cgroup_zone_lruvec(struct zone
*zone
,
1304 struct mem_cgroup
*memcg
)
1306 struct mem_cgroup_per_zone
*mz
;
1307 struct lruvec
*lruvec
;
1309 if (mem_cgroup_disabled()) {
1310 lruvec
= &zone
->lruvec
;
1314 mz
= mem_cgroup_zoneinfo(memcg
, zone_to_nid(zone
), zone_idx(zone
));
1315 lruvec
= &mz
->lruvec
;
1318 * Since a node can be onlined after the mem_cgroup was created,
1319 * we have to be prepared to initialize lruvec->zone here;
1320 * and if offlined then reonlined, we need to reinitialize it.
1322 if (unlikely(lruvec
->zone
!= zone
))
1323 lruvec
->zone
= zone
;
1328 * Following LRU functions are allowed to be used without PCG_LOCK.
1329 * Operations are called by routine of global LRU independently from memcg.
1330 * What we have to take care of here is validness of pc->mem_cgroup.
1332 * Changes to pc->mem_cgroup happens when
1335 * In typical case, "charge" is done before add-to-lru. Exception is SwapCache.
1336 * It is added to LRU before charge.
1337 * If PCG_USED bit is not set, page_cgroup is not added to this private LRU.
1338 * When moving account, the page is not on LRU. It's isolated.
1342 * mem_cgroup_page_lruvec - return lruvec for adding an lru page
1344 * @zone: zone of the page
1346 struct lruvec
*mem_cgroup_page_lruvec(struct page
*page
, struct zone
*zone
)
1348 struct mem_cgroup_per_zone
*mz
;
1349 struct mem_cgroup
*memcg
;
1350 struct page_cgroup
*pc
;
1351 struct lruvec
*lruvec
;
1353 if (mem_cgroup_disabled()) {
1354 lruvec
= &zone
->lruvec
;
1358 pc
= lookup_page_cgroup(page
);
1359 memcg
= pc
->mem_cgroup
;
1362 * Surreptitiously switch any uncharged offlist page to root:
1363 * an uncharged page off lru does nothing to secure
1364 * its former mem_cgroup from sudden removal.
1366 * Our caller holds lru_lock, and PageCgroupUsed is updated
1367 * under page_cgroup lock: between them, they make all uses
1368 * of pc->mem_cgroup safe.
1370 if (!PageLRU(page
) && !PageCgroupUsed(pc
) && memcg
!= root_mem_cgroup
)
1371 pc
->mem_cgroup
= memcg
= root_mem_cgroup
;
1373 mz
= page_cgroup_zoneinfo(memcg
, page
);
1374 lruvec
= &mz
->lruvec
;
1377 * Since a node can be onlined after the mem_cgroup was created,
1378 * we have to be prepared to initialize lruvec->zone here;
1379 * and if offlined then reonlined, we need to reinitialize it.
1381 if (unlikely(lruvec
->zone
!= zone
))
1382 lruvec
->zone
= zone
;
1387 * mem_cgroup_update_lru_size - account for adding or removing an lru page
1388 * @lruvec: mem_cgroup per zone lru vector
1389 * @lru: index of lru list the page is sitting on
1390 * @nr_pages: positive when adding or negative when removing
1392 * This function must be called when a page is added to or removed from an
1395 void mem_cgroup_update_lru_size(struct lruvec
*lruvec
, enum lru_list lru
,
1398 struct mem_cgroup_per_zone
*mz
;
1399 unsigned long *lru_size
;
1401 if (mem_cgroup_disabled())
1404 mz
= container_of(lruvec
, struct mem_cgroup_per_zone
, lruvec
);
1405 lru_size
= mz
->lru_size
+ lru
;
1406 *lru_size
+= nr_pages
;
1407 VM_BUG_ON((long)(*lru_size
) < 0);
1411 * Checks whether given mem is same or in the root_mem_cgroup's
1414 bool __mem_cgroup_same_or_subtree(const struct mem_cgroup
*root_memcg
,
1415 struct mem_cgroup
*memcg
)
1417 if (root_memcg
== memcg
)
1419 if (!root_memcg
->use_hierarchy
|| !memcg
)
1421 return css_is_ancestor(&memcg
->css
, &root_memcg
->css
);
1424 static bool mem_cgroup_same_or_subtree(const struct mem_cgroup
*root_memcg
,
1425 struct mem_cgroup
*memcg
)
1430 ret
= __mem_cgroup_same_or_subtree(root_memcg
, memcg
);
1435 bool task_in_mem_cgroup(struct task_struct
*task
,
1436 const struct mem_cgroup
*memcg
)
1438 struct mem_cgroup
*curr
= NULL
;
1439 struct task_struct
*p
;
1442 p
= find_lock_task_mm(task
);
1444 curr
= try_get_mem_cgroup_from_mm(p
->mm
);
1448 * All threads may have already detached their mm's, but the oom
1449 * killer still needs to detect if they have already been oom
1450 * killed to prevent needlessly killing additional tasks.
1453 curr
= mem_cgroup_from_task(task
);
1455 css_get(&curr
->css
);
1461 * We should check use_hierarchy of "memcg" not "curr". Because checking
1462 * use_hierarchy of "curr" here make this function true if hierarchy is
1463 * enabled in "curr" and "curr" is a child of "memcg" in *cgroup*
1464 * hierarchy(even if use_hierarchy is disabled in "memcg").
1466 ret
= mem_cgroup_same_or_subtree(memcg
, curr
);
1467 css_put(&curr
->css
);
1471 int mem_cgroup_inactive_anon_is_low(struct lruvec
*lruvec
)
1473 unsigned long inactive_ratio
;
1474 unsigned long inactive
;
1475 unsigned long active
;
1478 inactive
= mem_cgroup_get_lru_size(lruvec
, LRU_INACTIVE_ANON
);
1479 active
= mem_cgroup_get_lru_size(lruvec
, LRU_ACTIVE_ANON
);
1481 gb
= (inactive
+ active
) >> (30 - PAGE_SHIFT
);
1483 inactive_ratio
= int_sqrt(10 * gb
);
1487 return inactive
* inactive_ratio
< active
;
1490 #define mem_cgroup_from_res_counter(counter, member) \
1491 container_of(counter, struct mem_cgroup, member)
1494 * mem_cgroup_margin - calculate chargeable space of a memory cgroup
1495 * @memcg: the memory cgroup
1497 * Returns the maximum amount of memory @mem can be charged with, in
1500 static unsigned long mem_cgroup_margin(struct mem_cgroup
*memcg
)
1502 unsigned long long margin
;
1504 margin
= res_counter_margin(&memcg
->res
);
1505 if (do_swap_account
)
1506 margin
= min(margin
, res_counter_margin(&memcg
->memsw
));
1507 return margin
>> PAGE_SHIFT
;
1510 int mem_cgroup_swappiness(struct mem_cgroup
*memcg
)
1513 if (!css_parent(&memcg
->css
))
1514 return vm_swappiness
;
1516 return memcg
->swappiness
;
1520 * memcg->moving_account is used for checking possibility that some thread is
1521 * calling move_account(). When a thread on CPU-A starts moving pages under
1522 * a memcg, other threads should check memcg->moving_account under
1523 * rcu_read_lock(), like this:
1527 * memcg->moving_account+1 if (memcg->mocing_account)
1529 * synchronize_rcu() update something.
1534 /* for quick checking without looking up memcg */
1535 atomic_t memcg_moving __read_mostly
;
1537 static void mem_cgroup_start_move(struct mem_cgroup
*memcg
)
1539 atomic_inc(&memcg_moving
);
1540 atomic_inc(&memcg
->moving_account
);
1544 static void mem_cgroup_end_move(struct mem_cgroup
*memcg
)
1547 * Now, mem_cgroup_clear_mc() may call this function with NULL.
1548 * We check NULL in callee rather than caller.
1551 atomic_dec(&memcg_moving
);
1552 atomic_dec(&memcg
->moving_account
);
1557 * 2 routines for checking "mem" is under move_account() or not.
1559 * mem_cgroup_stolen() - checking whether a cgroup is mc.from or not. This
1560 * is used for avoiding races in accounting. If true,
1561 * pc->mem_cgroup may be overwritten.
1563 * mem_cgroup_under_move() - checking a cgroup is mc.from or mc.to or
1564 * under hierarchy of moving cgroups. This is for
1565 * waiting at hith-memory prressure caused by "move".
1568 static bool mem_cgroup_stolen(struct mem_cgroup
*memcg
)
1570 VM_BUG_ON(!rcu_read_lock_held());
1571 return atomic_read(&memcg
->moving_account
) > 0;
1574 static bool mem_cgroup_under_move(struct mem_cgroup
*memcg
)
1576 struct mem_cgroup
*from
;
1577 struct mem_cgroup
*to
;
1580 * Unlike task_move routines, we access mc.to, mc.from not under
1581 * mutual exclusion by cgroup_mutex. Here, we take spinlock instead.
1583 spin_lock(&mc
.lock
);
1589 ret
= mem_cgroup_same_or_subtree(memcg
, from
)
1590 || mem_cgroup_same_or_subtree(memcg
, to
);
1592 spin_unlock(&mc
.lock
);
1596 static bool mem_cgroup_wait_acct_move(struct mem_cgroup
*memcg
)
1598 if (mc
.moving_task
&& current
!= mc
.moving_task
) {
1599 if (mem_cgroup_under_move(memcg
)) {
1601 prepare_to_wait(&mc
.waitq
, &wait
, TASK_INTERRUPTIBLE
);
1602 /* moving charge context might have finished. */
1605 finish_wait(&mc
.waitq
, &wait
);
1613 * Take this lock when
1614 * - a code tries to modify page's memcg while it's USED.
1615 * - a code tries to modify page state accounting in a memcg.
1616 * see mem_cgroup_stolen(), too.
1618 static void move_lock_mem_cgroup(struct mem_cgroup
*memcg
,
1619 unsigned long *flags
)
1621 spin_lock_irqsave(&memcg
->move_lock
, *flags
);
1624 static void move_unlock_mem_cgroup(struct mem_cgroup
*memcg
,
1625 unsigned long *flags
)
1627 spin_unlock_irqrestore(&memcg
->move_lock
, *flags
);
1630 #define K(x) ((x) << (PAGE_SHIFT-10))
1632 * mem_cgroup_print_oom_info: Print OOM information relevant to memory controller.
1633 * @memcg: The memory cgroup that went over limit
1634 * @p: Task that is going to be killed
1636 * NOTE: @memcg and @p's mem_cgroup can be different when hierarchy is
1639 void mem_cgroup_print_oom_info(struct mem_cgroup
*memcg
, struct task_struct
*p
)
1641 struct cgroup
*task_cgrp
;
1642 struct cgroup
*mem_cgrp
;
1644 * Need a buffer in BSS, can't rely on allocations. The code relies
1645 * on the assumption that OOM is serialized for memory controller.
1646 * If this assumption is broken, revisit this code.
1648 static char memcg_name
[PATH_MAX
];
1650 struct mem_cgroup
*iter
;
1658 mem_cgrp
= memcg
->css
.cgroup
;
1659 task_cgrp
= task_cgroup(p
, mem_cgroup_subsys_id
);
1661 ret
= cgroup_path(task_cgrp
, memcg_name
, PATH_MAX
);
1664 * Unfortunately, we are unable to convert to a useful name
1665 * But we'll still print out the usage information
1672 pr_info("Task in %s killed", memcg_name
);
1675 ret
= cgroup_path(mem_cgrp
, memcg_name
, PATH_MAX
);
1683 * Continues from above, so we don't need an KERN_ level
1685 pr_cont(" as a result of limit of %s\n", memcg_name
);
1688 pr_info("memory: usage %llukB, limit %llukB, failcnt %llu\n",
1689 res_counter_read_u64(&memcg
->res
, RES_USAGE
) >> 10,
1690 res_counter_read_u64(&memcg
->res
, RES_LIMIT
) >> 10,
1691 res_counter_read_u64(&memcg
->res
, RES_FAILCNT
));
1692 pr_info("memory+swap: usage %llukB, limit %llukB, failcnt %llu\n",
1693 res_counter_read_u64(&memcg
->memsw
, RES_USAGE
) >> 10,
1694 res_counter_read_u64(&memcg
->memsw
, RES_LIMIT
) >> 10,
1695 res_counter_read_u64(&memcg
->memsw
, RES_FAILCNT
));
1696 pr_info("kmem: usage %llukB, limit %llukB, failcnt %llu\n",
1697 res_counter_read_u64(&memcg
->kmem
, RES_USAGE
) >> 10,
1698 res_counter_read_u64(&memcg
->kmem
, RES_LIMIT
) >> 10,
1699 res_counter_read_u64(&memcg
->kmem
, RES_FAILCNT
));
1701 for_each_mem_cgroup_tree(iter
, memcg
) {
1702 pr_info("Memory cgroup stats");
1705 ret
= cgroup_path(iter
->css
.cgroup
, memcg_name
, PATH_MAX
);
1707 pr_cont(" for %s", memcg_name
);
1711 for (i
= 0; i
< MEM_CGROUP_STAT_NSTATS
; i
++) {
1712 if (i
== MEM_CGROUP_STAT_SWAP
&& !do_swap_account
)
1714 pr_cont(" %s:%ldKB", mem_cgroup_stat_names
[i
],
1715 K(mem_cgroup_read_stat(iter
, i
)));
1718 for (i
= 0; i
< NR_LRU_LISTS
; i
++)
1719 pr_cont(" %s:%luKB", mem_cgroup_lru_names
[i
],
1720 K(mem_cgroup_nr_lru_pages(iter
, BIT(i
))));
1727 * This function returns the number of memcg under hierarchy tree. Returns
1728 * 1(self count) if no children.
1730 static int mem_cgroup_count_children(struct mem_cgroup
*memcg
)
1733 struct mem_cgroup
*iter
;
1735 for_each_mem_cgroup_tree(iter
, memcg
)
1741 * Return the memory (and swap, if configured) limit for a memcg.
1743 static u64
mem_cgroup_get_limit(struct mem_cgroup
*memcg
)
1747 limit
= res_counter_read_u64(&memcg
->res
, RES_LIMIT
);
1750 * Do not consider swap space if we cannot swap due to swappiness
1752 if (mem_cgroup_swappiness(memcg
)) {
1755 limit
+= total_swap_pages
<< PAGE_SHIFT
;
1756 memsw
= res_counter_read_u64(&memcg
->memsw
, RES_LIMIT
);
1759 * If memsw is finite and limits the amount of swap space
1760 * available to this memcg, return that limit.
1762 limit
= min(limit
, memsw
);
1768 static void mem_cgroup_out_of_memory(struct mem_cgroup
*memcg
, gfp_t gfp_mask
,
1771 struct mem_cgroup
*iter
;
1772 unsigned long chosen_points
= 0;
1773 unsigned long totalpages
;
1774 unsigned int points
= 0;
1775 struct task_struct
*chosen
= NULL
;
1778 * If current has a pending SIGKILL or is exiting, then automatically
1779 * select it. The goal is to allow it to allocate so that it may
1780 * quickly exit and free its memory.
1782 if (fatal_signal_pending(current
) || current
->flags
& PF_EXITING
) {
1783 set_thread_flag(TIF_MEMDIE
);
1787 check_panic_on_oom(CONSTRAINT_MEMCG
, gfp_mask
, order
, NULL
);
1788 totalpages
= mem_cgroup_get_limit(memcg
) >> PAGE_SHIFT
? : 1;
1789 for_each_mem_cgroup_tree(iter
, memcg
) {
1790 struct css_task_iter it
;
1791 struct task_struct
*task
;
1793 css_task_iter_start(&iter
->css
, &it
);
1794 while ((task
= css_task_iter_next(&it
))) {
1795 switch (oom_scan_process_thread(task
, totalpages
, NULL
,
1797 case OOM_SCAN_SELECT
:
1799 put_task_struct(chosen
);
1801 chosen_points
= ULONG_MAX
;
1802 get_task_struct(chosen
);
1804 case OOM_SCAN_CONTINUE
:
1806 case OOM_SCAN_ABORT
:
1807 css_task_iter_end(&it
);
1808 mem_cgroup_iter_break(memcg
, iter
);
1810 put_task_struct(chosen
);
1815 points
= oom_badness(task
, memcg
, NULL
, totalpages
);
1816 if (points
> chosen_points
) {
1818 put_task_struct(chosen
);
1820 chosen_points
= points
;
1821 get_task_struct(chosen
);
1824 css_task_iter_end(&it
);
1829 points
= chosen_points
* 1000 / totalpages
;
1830 oom_kill_process(chosen
, gfp_mask
, order
, points
, totalpages
, memcg
,
1831 NULL
, "Memory cgroup out of memory");
1834 static unsigned long mem_cgroup_reclaim(struct mem_cgroup
*memcg
,
1836 unsigned long flags
)
1838 unsigned long total
= 0;
1839 bool noswap
= false;
1842 if (flags
& MEM_CGROUP_RECLAIM_NOSWAP
)
1844 if (!(flags
& MEM_CGROUP_RECLAIM_SHRINK
) && memcg
->memsw_is_minimum
)
1847 for (loop
= 0; loop
< MEM_CGROUP_MAX_RECLAIM_LOOPS
; loop
++) {
1849 drain_all_stock_async(memcg
);
1850 total
+= try_to_free_mem_cgroup_pages(memcg
, gfp_mask
, noswap
);
1852 * Allow limit shrinkers, which are triggered directly
1853 * by userspace, to catch signals and stop reclaim
1854 * after minimal progress, regardless of the margin.
1856 if (total
&& (flags
& MEM_CGROUP_RECLAIM_SHRINK
))
1858 if (mem_cgroup_margin(memcg
))
1861 * If nothing was reclaimed after two attempts, there
1862 * may be no reclaimable pages in this hierarchy.
1871 * test_mem_cgroup_node_reclaimable
1872 * @memcg: the target memcg
1873 * @nid: the node ID to be checked.
1874 * @noswap : specify true here if the user wants flle only information.
1876 * This function returns whether the specified memcg contains any
1877 * reclaimable pages on a node. Returns true if there are any reclaimable
1878 * pages in the node.
1880 static bool test_mem_cgroup_node_reclaimable(struct mem_cgroup
*memcg
,
1881 int nid
, bool noswap
)
1883 if (mem_cgroup_node_nr_lru_pages(memcg
, nid
, LRU_ALL_FILE
))
1885 if (noswap
|| !total_swap_pages
)
1887 if (mem_cgroup_node_nr_lru_pages(memcg
, nid
, LRU_ALL_ANON
))
1892 #if MAX_NUMNODES > 1
1895 * Always updating the nodemask is not very good - even if we have an empty
1896 * list or the wrong list here, we can start from some node and traverse all
1897 * nodes based on the zonelist. So update the list loosely once per 10 secs.
1900 static void mem_cgroup_may_update_nodemask(struct mem_cgroup
*memcg
)
1904 * numainfo_events > 0 means there was at least NUMAINFO_EVENTS_TARGET
1905 * pagein/pageout changes since the last update.
1907 if (!atomic_read(&memcg
->numainfo_events
))
1909 if (atomic_inc_return(&memcg
->numainfo_updating
) > 1)
1912 /* make a nodemask where this memcg uses memory from */
1913 memcg
->scan_nodes
= node_states
[N_MEMORY
];
1915 for_each_node_mask(nid
, node_states
[N_MEMORY
]) {
1917 if (!test_mem_cgroup_node_reclaimable(memcg
, nid
, false))
1918 node_clear(nid
, memcg
->scan_nodes
);
1921 atomic_set(&memcg
->numainfo_events
, 0);
1922 atomic_set(&memcg
->numainfo_updating
, 0);
1926 * Selecting a node where we start reclaim from. Because what we need is just
1927 * reducing usage counter, start from anywhere is O,K. Considering
1928 * memory reclaim from current node, there are pros. and cons.
1930 * Freeing memory from current node means freeing memory from a node which
1931 * we'll use or we've used. So, it may make LRU bad. And if several threads
1932 * hit limits, it will see a contention on a node. But freeing from remote
1933 * node means more costs for memory reclaim because of memory latency.
1935 * Now, we use round-robin. Better algorithm is welcomed.
1937 int mem_cgroup_select_victim_node(struct mem_cgroup
*memcg
)
1941 mem_cgroup_may_update_nodemask(memcg
);
1942 node
= memcg
->last_scanned_node
;
1944 node
= next_node(node
, memcg
->scan_nodes
);
1945 if (node
== MAX_NUMNODES
)
1946 node
= first_node(memcg
->scan_nodes
);
1948 * We call this when we hit limit, not when pages are added to LRU.
1949 * No LRU may hold pages because all pages are UNEVICTABLE or
1950 * memcg is too small and all pages are not on LRU. In that case,
1951 * we use curret node.
1953 if (unlikely(node
== MAX_NUMNODES
))
1954 node
= numa_node_id();
1956 memcg
->last_scanned_node
= node
;
1961 * Check all nodes whether it contains reclaimable pages or not.
1962 * For quick scan, we make use of scan_nodes. This will allow us to skip
1963 * unused nodes. But scan_nodes is lazily updated and may not cotain
1964 * enough new information. We need to do double check.
1966 static bool mem_cgroup_reclaimable(struct mem_cgroup
*memcg
, bool noswap
)
1971 * quick check...making use of scan_node.
1972 * We can skip unused nodes.
1974 if (!nodes_empty(memcg
->scan_nodes
)) {
1975 for (nid
= first_node(memcg
->scan_nodes
);
1977 nid
= next_node(nid
, memcg
->scan_nodes
)) {
1979 if (test_mem_cgroup_node_reclaimable(memcg
, nid
, noswap
))
1984 * Check rest of nodes.
1986 for_each_node_state(nid
, N_MEMORY
) {
1987 if (node_isset(nid
, memcg
->scan_nodes
))
1989 if (test_mem_cgroup_node_reclaimable(memcg
, nid
, noswap
))
1996 int mem_cgroup_select_victim_node(struct mem_cgroup
*memcg
)
2001 static bool mem_cgroup_reclaimable(struct mem_cgroup
*memcg
, bool noswap
)
2003 return test_mem_cgroup_node_reclaimable(memcg
, 0, noswap
);
2007 static int mem_cgroup_soft_reclaim(struct mem_cgroup
*root_memcg
,
2010 unsigned long *total_scanned
)
2012 struct mem_cgroup
*victim
= NULL
;
2015 unsigned long excess
;
2016 unsigned long nr_scanned
;
2017 struct mem_cgroup_reclaim_cookie reclaim
= {
2022 excess
= res_counter_soft_limit_excess(&root_memcg
->res
) >> PAGE_SHIFT
;
2025 victim
= mem_cgroup_iter(root_memcg
, victim
, &reclaim
);
2030 * If we have not been able to reclaim
2031 * anything, it might because there are
2032 * no reclaimable pages under this hierarchy
2037 * We want to do more targeted reclaim.
2038 * excess >> 2 is not to excessive so as to
2039 * reclaim too much, nor too less that we keep
2040 * coming back to reclaim from this cgroup
2042 if (total
>= (excess
>> 2) ||
2043 (loop
> MEM_CGROUP_MAX_RECLAIM_LOOPS
))
2048 if (!mem_cgroup_reclaimable(victim
, false))
2050 total
+= mem_cgroup_shrink_node_zone(victim
, gfp_mask
, false,
2052 *total_scanned
+= nr_scanned
;
2053 if (!res_counter_soft_limit_excess(&root_memcg
->res
))
2056 mem_cgroup_iter_break(root_memcg
, victim
);
2061 * Check OOM-Killer is already running under our hierarchy.
2062 * If someone is running, return false.
2063 * Has to be called with memcg_oom_lock
2065 static bool mem_cgroup_oom_lock(struct mem_cgroup
*memcg
)
2067 struct mem_cgroup
*iter
, *failed
= NULL
;
2069 for_each_mem_cgroup_tree(iter
, memcg
) {
2070 if (iter
->oom_lock
) {
2072 * this subtree of our hierarchy is already locked
2073 * so we cannot give a lock.
2076 mem_cgroup_iter_break(memcg
, iter
);
2079 iter
->oom_lock
= true;
2086 * OK, we failed to lock the whole subtree so we have to clean up
2087 * what we set up to the failing subtree
2089 for_each_mem_cgroup_tree(iter
, memcg
) {
2090 if (iter
== failed
) {
2091 mem_cgroup_iter_break(memcg
, iter
);
2094 iter
->oom_lock
= false;
2100 * Has to be called with memcg_oom_lock
2102 static int mem_cgroup_oom_unlock(struct mem_cgroup
*memcg
)
2104 struct mem_cgroup
*iter
;
2106 for_each_mem_cgroup_tree(iter
, memcg
)
2107 iter
->oom_lock
= false;
2111 static void mem_cgroup_mark_under_oom(struct mem_cgroup
*memcg
)
2113 struct mem_cgroup
*iter
;
2115 for_each_mem_cgroup_tree(iter
, memcg
)
2116 atomic_inc(&iter
->under_oom
);
2119 static void mem_cgroup_unmark_under_oom(struct mem_cgroup
*memcg
)
2121 struct mem_cgroup
*iter
;
2124 * When a new child is created while the hierarchy is under oom,
2125 * mem_cgroup_oom_lock() may not be called. We have to use
2126 * atomic_add_unless() here.
2128 for_each_mem_cgroup_tree(iter
, memcg
)
2129 atomic_add_unless(&iter
->under_oom
, -1, 0);
2132 static DEFINE_SPINLOCK(memcg_oom_lock
);
2133 static DECLARE_WAIT_QUEUE_HEAD(memcg_oom_waitq
);
2135 struct oom_wait_info
{
2136 struct mem_cgroup
*memcg
;
2140 static int memcg_oom_wake_function(wait_queue_t
*wait
,
2141 unsigned mode
, int sync
, void *arg
)
2143 struct mem_cgroup
*wake_memcg
= (struct mem_cgroup
*)arg
;
2144 struct mem_cgroup
*oom_wait_memcg
;
2145 struct oom_wait_info
*oom_wait_info
;
2147 oom_wait_info
= container_of(wait
, struct oom_wait_info
, wait
);
2148 oom_wait_memcg
= oom_wait_info
->memcg
;
2151 * Both of oom_wait_info->memcg and wake_memcg are stable under us.
2152 * Then we can use css_is_ancestor without taking care of RCU.
2154 if (!mem_cgroup_same_or_subtree(oom_wait_memcg
, wake_memcg
)
2155 && !mem_cgroup_same_or_subtree(wake_memcg
, oom_wait_memcg
))
2157 return autoremove_wake_function(wait
, mode
, sync
, arg
);
2160 static void memcg_wakeup_oom(struct mem_cgroup
*memcg
)
2162 /* for filtering, pass "memcg" as argument. */
2163 __wake_up(&memcg_oom_waitq
, TASK_NORMAL
, 0, memcg
);
2166 static void memcg_oom_recover(struct mem_cgroup
*memcg
)
2168 if (memcg
&& atomic_read(&memcg
->under_oom
))
2169 memcg_wakeup_oom(memcg
);
2173 * try to call OOM killer. returns false if we should exit memory-reclaim loop.
2175 static bool mem_cgroup_handle_oom(struct mem_cgroup
*memcg
, gfp_t mask
,
2178 struct oom_wait_info owait
;
2179 bool locked
, need_to_kill
;
2181 owait
.memcg
= memcg
;
2182 owait
.wait
.flags
= 0;
2183 owait
.wait
.func
= memcg_oom_wake_function
;
2184 owait
.wait
.private = current
;
2185 INIT_LIST_HEAD(&owait
.wait
.task_list
);
2186 need_to_kill
= true;
2187 mem_cgroup_mark_under_oom(memcg
);
2189 /* At first, try to OOM lock hierarchy under memcg.*/
2190 spin_lock(&memcg_oom_lock
);
2191 locked
= mem_cgroup_oom_lock(memcg
);
2193 * Even if signal_pending(), we can't quit charge() loop without
2194 * accounting. So, UNINTERRUPTIBLE is appropriate. But SIGKILL
2195 * under OOM is always welcomed, use TASK_KILLABLE here.
2197 prepare_to_wait(&memcg_oom_waitq
, &owait
.wait
, TASK_KILLABLE
);
2198 if (!locked
|| memcg
->oom_kill_disable
)
2199 need_to_kill
= false;
2201 mem_cgroup_oom_notify(memcg
);
2202 spin_unlock(&memcg_oom_lock
);
2205 finish_wait(&memcg_oom_waitq
, &owait
.wait
);
2206 mem_cgroup_out_of_memory(memcg
, mask
, order
);
2209 finish_wait(&memcg_oom_waitq
, &owait
.wait
);
2211 spin_lock(&memcg_oom_lock
);
2213 mem_cgroup_oom_unlock(memcg
);
2214 memcg_wakeup_oom(memcg
);
2215 spin_unlock(&memcg_oom_lock
);
2217 mem_cgroup_unmark_under_oom(memcg
);
2219 if (test_thread_flag(TIF_MEMDIE
) || fatal_signal_pending(current
))
2221 /* Give chance to dying process */
2222 schedule_timeout_uninterruptible(1);
2227 * Currently used to update mapped file statistics, but the routine can be
2228 * generalized to update other statistics as well.
2230 * Notes: Race condition
2232 * We usually use page_cgroup_lock() for accessing page_cgroup member but
2233 * it tends to be costly. But considering some conditions, we doesn't need
2234 * to do so _always_.
2236 * Considering "charge", lock_page_cgroup() is not required because all
2237 * file-stat operations happen after a page is attached to radix-tree. There
2238 * are no race with "charge".
2240 * Considering "uncharge", we know that memcg doesn't clear pc->mem_cgroup
2241 * at "uncharge" intentionally. So, we always see valid pc->mem_cgroup even
2242 * if there are race with "uncharge". Statistics itself is properly handled
2245 * Considering "move", this is an only case we see a race. To make the race
2246 * small, we check mm->moving_account and detect there are possibility of race
2247 * If there is, we take a lock.
2250 void __mem_cgroup_begin_update_page_stat(struct page
*page
,
2251 bool *locked
, unsigned long *flags
)
2253 struct mem_cgroup
*memcg
;
2254 struct page_cgroup
*pc
;
2256 pc
= lookup_page_cgroup(page
);
2258 memcg
= pc
->mem_cgroup
;
2259 if (unlikely(!memcg
|| !PageCgroupUsed(pc
)))
2262 * If this memory cgroup is not under account moving, we don't
2263 * need to take move_lock_mem_cgroup(). Because we already hold
2264 * rcu_read_lock(), any calls to move_account will be delayed until
2265 * rcu_read_unlock() if mem_cgroup_stolen() == true.
2267 if (!mem_cgroup_stolen(memcg
))
2270 move_lock_mem_cgroup(memcg
, flags
);
2271 if (memcg
!= pc
->mem_cgroup
|| !PageCgroupUsed(pc
)) {
2272 move_unlock_mem_cgroup(memcg
, flags
);
2278 void __mem_cgroup_end_update_page_stat(struct page
*page
, unsigned long *flags
)
2280 struct page_cgroup
*pc
= lookup_page_cgroup(page
);
2283 * It's guaranteed that pc->mem_cgroup never changes while
2284 * lock is held because a routine modifies pc->mem_cgroup
2285 * should take move_lock_mem_cgroup().
2287 move_unlock_mem_cgroup(pc
->mem_cgroup
, flags
);
2290 void mem_cgroup_update_page_stat(struct page
*page
,
2291 enum mem_cgroup_page_stat_item idx
, int val
)
2293 struct mem_cgroup
*memcg
;
2294 struct page_cgroup
*pc
= lookup_page_cgroup(page
);
2295 unsigned long uninitialized_var(flags
);
2297 if (mem_cgroup_disabled())
2300 memcg
= pc
->mem_cgroup
;
2301 if (unlikely(!memcg
|| !PageCgroupUsed(pc
)))
2305 case MEMCG_NR_FILE_MAPPED
:
2306 idx
= MEM_CGROUP_STAT_FILE_MAPPED
;
2312 this_cpu_add(memcg
->stat
->count
[idx
], val
);
2316 * size of first charge trial. "32" comes from vmscan.c's magic value.
2317 * TODO: maybe necessary to use big numbers in big irons.
2319 #define CHARGE_BATCH 32U
2320 struct memcg_stock_pcp
{
2321 struct mem_cgroup
*cached
; /* this never be root cgroup */
2322 unsigned int nr_pages
;
2323 struct work_struct work
;
2324 unsigned long flags
;
2325 #define FLUSHING_CACHED_CHARGE 0
2327 static DEFINE_PER_CPU(struct memcg_stock_pcp
, memcg_stock
);
2328 static DEFINE_MUTEX(percpu_charge_mutex
);
2331 * consume_stock: Try to consume stocked charge on this cpu.
2332 * @memcg: memcg to consume from.
2333 * @nr_pages: how many pages to charge.
2335 * The charges will only happen if @memcg matches the current cpu's memcg
2336 * stock, and at least @nr_pages are available in that stock. Failure to
2337 * service an allocation will refill the stock.
2339 * returns true if successful, false otherwise.
2341 static bool consume_stock(struct mem_cgroup
*memcg
, unsigned int nr_pages
)
2343 struct memcg_stock_pcp
*stock
;
2346 if (nr_pages
> CHARGE_BATCH
)
2349 stock
= &get_cpu_var(memcg_stock
);
2350 if (memcg
== stock
->cached
&& stock
->nr_pages
>= nr_pages
)
2351 stock
->nr_pages
-= nr_pages
;
2352 else /* need to call res_counter_charge */
2354 put_cpu_var(memcg_stock
);
2359 * Returns stocks cached in percpu to res_counter and reset cached information.
2361 static void drain_stock(struct memcg_stock_pcp
*stock
)
2363 struct mem_cgroup
*old
= stock
->cached
;
2365 if (stock
->nr_pages
) {
2366 unsigned long bytes
= stock
->nr_pages
* PAGE_SIZE
;
2368 res_counter_uncharge(&old
->res
, bytes
);
2369 if (do_swap_account
)
2370 res_counter_uncharge(&old
->memsw
, bytes
);
2371 stock
->nr_pages
= 0;
2373 stock
->cached
= NULL
;
2377 * This must be called under preempt disabled or must be called by
2378 * a thread which is pinned to local cpu.
2380 static void drain_local_stock(struct work_struct
*dummy
)
2382 struct memcg_stock_pcp
*stock
= &__get_cpu_var(memcg_stock
);
2384 clear_bit(FLUSHING_CACHED_CHARGE
, &stock
->flags
);
2387 static void __init
memcg_stock_init(void)
2391 for_each_possible_cpu(cpu
) {
2392 struct memcg_stock_pcp
*stock
=
2393 &per_cpu(memcg_stock
, cpu
);
2394 INIT_WORK(&stock
->work
, drain_local_stock
);
2399 * Cache charges(val) which is from res_counter, to local per_cpu area.
2400 * This will be consumed by consume_stock() function, later.
2402 static void refill_stock(struct mem_cgroup
*memcg
, unsigned int nr_pages
)
2404 struct memcg_stock_pcp
*stock
= &get_cpu_var(memcg_stock
);
2406 if (stock
->cached
!= memcg
) { /* reset if necessary */
2408 stock
->cached
= memcg
;
2410 stock
->nr_pages
+= nr_pages
;
2411 put_cpu_var(memcg_stock
);
2415 * Drains all per-CPU charge caches for given root_memcg resp. subtree
2416 * of the hierarchy under it. sync flag says whether we should block
2417 * until the work is done.
2419 static void drain_all_stock(struct mem_cgroup
*root_memcg
, bool sync
)
2423 /* Notify other cpus that system-wide "drain" is running */
2426 for_each_online_cpu(cpu
) {
2427 struct memcg_stock_pcp
*stock
= &per_cpu(memcg_stock
, cpu
);
2428 struct mem_cgroup
*memcg
;
2430 memcg
= stock
->cached
;
2431 if (!memcg
|| !stock
->nr_pages
)
2433 if (!mem_cgroup_same_or_subtree(root_memcg
, memcg
))
2435 if (!test_and_set_bit(FLUSHING_CACHED_CHARGE
, &stock
->flags
)) {
2437 drain_local_stock(&stock
->work
);
2439 schedule_work_on(cpu
, &stock
->work
);
2447 for_each_online_cpu(cpu
) {
2448 struct memcg_stock_pcp
*stock
= &per_cpu(memcg_stock
, cpu
);
2449 if (test_bit(FLUSHING_CACHED_CHARGE
, &stock
->flags
))
2450 flush_work(&stock
->work
);
2457 * Tries to drain stocked charges in other cpus. This function is asynchronous
2458 * and just put a work per cpu for draining localy on each cpu. Caller can
2459 * expects some charges will be back to res_counter later but cannot wait for
2462 static void drain_all_stock_async(struct mem_cgroup
*root_memcg
)
2465 * If someone calls draining, avoid adding more kworker runs.
2467 if (!mutex_trylock(&percpu_charge_mutex
))
2469 drain_all_stock(root_memcg
, false);
2470 mutex_unlock(&percpu_charge_mutex
);
2473 /* This is a synchronous drain interface. */
2474 static void drain_all_stock_sync(struct mem_cgroup
*root_memcg
)
2476 /* called when force_empty is called */
2477 mutex_lock(&percpu_charge_mutex
);
2478 drain_all_stock(root_memcg
, true);
2479 mutex_unlock(&percpu_charge_mutex
);
2483 * This function drains percpu counter value from DEAD cpu and
2484 * move it to local cpu. Note that this function can be preempted.
2486 static void mem_cgroup_drain_pcp_counter(struct mem_cgroup
*memcg
, int cpu
)
2490 spin_lock(&memcg
->pcp_counter_lock
);
2491 for (i
= 0; i
< MEM_CGROUP_STAT_NSTATS
; i
++) {
2492 long x
= per_cpu(memcg
->stat
->count
[i
], cpu
);
2494 per_cpu(memcg
->stat
->count
[i
], cpu
) = 0;
2495 memcg
->nocpu_base
.count
[i
] += x
;
2497 for (i
= 0; i
< MEM_CGROUP_EVENTS_NSTATS
; i
++) {
2498 unsigned long x
= per_cpu(memcg
->stat
->events
[i
], cpu
);
2500 per_cpu(memcg
->stat
->events
[i
], cpu
) = 0;
2501 memcg
->nocpu_base
.events
[i
] += x
;
2503 spin_unlock(&memcg
->pcp_counter_lock
);
2506 static int memcg_cpu_hotplug_callback(struct notifier_block
*nb
,
2507 unsigned long action
,
2510 int cpu
= (unsigned long)hcpu
;
2511 struct memcg_stock_pcp
*stock
;
2512 struct mem_cgroup
*iter
;
2514 if (action
== CPU_ONLINE
)
2517 if (action
!= CPU_DEAD
&& action
!= CPU_DEAD_FROZEN
)
2520 for_each_mem_cgroup(iter
)
2521 mem_cgroup_drain_pcp_counter(iter
, cpu
);
2523 stock
= &per_cpu(memcg_stock
, cpu
);
2529 /* See __mem_cgroup_try_charge() for details */
2531 CHARGE_OK
, /* success */
2532 CHARGE_RETRY
, /* need to retry but retry is not bad */
2533 CHARGE_NOMEM
, /* we can't do more. return -ENOMEM */
2534 CHARGE_WOULDBLOCK
, /* GFP_WAIT wasn't set and no enough res. */
2535 CHARGE_OOM_DIE
, /* the current is killed because of OOM */
2538 static int mem_cgroup_do_charge(struct mem_cgroup
*memcg
, gfp_t gfp_mask
,
2539 unsigned int nr_pages
, unsigned int min_pages
,
2542 unsigned long csize
= nr_pages
* PAGE_SIZE
;
2543 struct mem_cgroup
*mem_over_limit
;
2544 struct res_counter
*fail_res
;
2545 unsigned long flags
= 0;
2548 ret
= res_counter_charge(&memcg
->res
, csize
, &fail_res
);
2551 if (!do_swap_account
)
2553 ret
= res_counter_charge(&memcg
->memsw
, csize
, &fail_res
);
2557 res_counter_uncharge(&memcg
->res
, csize
);
2558 mem_over_limit
= mem_cgroup_from_res_counter(fail_res
, memsw
);
2559 flags
|= MEM_CGROUP_RECLAIM_NOSWAP
;
2561 mem_over_limit
= mem_cgroup_from_res_counter(fail_res
, res
);
2563 * Never reclaim on behalf of optional batching, retry with a
2564 * single page instead.
2566 if (nr_pages
> min_pages
)
2567 return CHARGE_RETRY
;
2569 if (!(gfp_mask
& __GFP_WAIT
))
2570 return CHARGE_WOULDBLOCK
;
2572 if (gfp_mask
& __GFP_NORETRY
)
2573 return CHARGE_NOMEM
;
2575 ret
= mem_cgroup_reclaim(mem_over_limit
, gfp_mask
, flags
);
2576 if (mem_cgroup_margin(mem_over_limit
) >= nr_pages
)
2577 return CHARGE_RETRY
;
2579 * Even though the limit is exceeded at this point, reclaim
2580 * may have been able to free some pages. Retry the charge
2581 * before killing the task.
2583 * Only for regular pages, though: huge pages are rather
2584 * unlikely to succeed so close to the limit, and we fall back
2585 * to regular pages anyway in case of failure.
2587 if (nr_pages
<= (1 << PAGE_ALLOC_COSTLY_ORDER
) && ret
)
2588 return CHARGE_RETRY
;
2591 * At task move, charge accounts can be doubly counted. So, it's
2592 * better to wait until the end of task_move if something is going on.
2594 if (mem_cgroup_wait_acct_move(mem_over_limit
))
2595 return CHARGE_RETRY
;
2597 /* If we don't need to call oom-killer at el, return immediately */
2599 return CHARGE_NOMEM
;
2601 if (!mem_cgroup_handle_oom(mem_over_limit
, gfp_mask
, get_order(csize
)))
2602 return CHARGE_OOM_DIE
;
2604 return CHARGE_RETRY
;
2608 * __mem_cgroup_try_charge() does
2609 * 1. detect memcg to be charged against from passed *mm and *ptr,
2610 * 2. update res_counter
2611 * 3. call memory reclaim if necessary.
2613 * In some special case, if the task is fatal, fatal_signal_pending() or
2614 * has TIF_MEMDIE, this function returns -EINTR while writing root_mem_cgroup
2615 * to *ptr. There are two reasons for this. 1: fatal threads should quit as soon
2616 * as possible without any hazards. 2: all pages should have a valid
2617 * pc->mem_cgroup. If mm is NULL and the caller doesn't pass a valid memcg
2618 * pointer, that is treated as a charge to root_mem_cgroup.
2620 * So __mem_cgroup_try_charge() will return
2621 * 0 ... on success, filling *ptr with a valid memcg pointer.
2622 * -ENOMEM ... charge failure because of resource limits.
2623 * -EINTR ... if thread is fatal. *ptr is filled with root_mem_cgroup.
2625 * Unlike the exported interface, an "oom" parameter is added. if oom==true,
2626 * the oom-killer can be invoked.
2628 static int __mem_cgroup_try_charge(struct mm_struct
*mm
,
2630 unsigned int nr_pages
,
2631 struct mem_cgroup
**ptr
,
2634 unsigned int batch
= max(CHARGE_BATCH
, nr_pages
);
2635 int nr_oom_retries
= MEM_CGROUP_RECLAIM_RETRIES
;
2636 struct mem_cgroup
*memcg
= NULL
;
2640 * Unlike gloval-vm's OOM-kill, we're not in memory shortage
2641 * in system level. So, allow to go ahead dying process in addition to
2644 if (unlikely(test_thread_flag(TIF_MEMDIE
)
2645 || fatal_signal_pending(current
)))
2649 * We always charge the cgroup the mm_struct belongs to.
2650 * The mm_struct's mem_cgroup changes on task migration if the
2651 * thread group leader migrates. It's possible that mm is not
2652 * set, if so charge the root memcg (happens for pagecache usage).
2655 *ptr
= root_mem_cgroup
;
2657 if (*ptr
) { /* css should be a valid one */
2659 if (mem_cgroup_is_root(memcg
))
2661 if (consume_stock(memcg
, nr_pages
))
2663 css_get(&memcg
->css
);
2665 struct task_struct
*p
;
2668 p
= rcu_dereference(mm
->owner
);
2670 * Because we don't have task_lock(), "p" can exit.
2671 * In that case, "memcg" can point to root or p can be NULL with
2672 * race with swapoff. Then, we have small risk of mis-accouning.
2673 * But such kind of mis-account by race always happens because
2674 * we don't have cgroup_mutex(). It's overkill and we allo that
2676 * (*) swapoff at el will charge against mm-struct not against
2677 * task-struct. So, mm->owner can be NULL.
2679 memcg
= mem_cgroup_from_task(p
);
2681 memcg
= root_mem_cgroup
;
2682 if (mem_cgroup_is_root(memcg
)) {
2686 if (consume_stock(memcg
, nr_pages
)) {
2688 * It seems dagerous to access memcg without css_get().
2689 * But considering how consume_stok works, it's not
2690 * necessary. If consume_stock success, some charges
2691 * from this memcg are cached on this cpu. So, we
2692 * don't need to call css_get()/css_tryget() before
2693 * calling consume_stock().
2698 /* after here, we may be blocked. we need to get refcnt */
2699 if (!css_tryget(&memcg
->css
)) {
2709 /* If killed, bypass charge */
2710 if (fatal_signal_pending(current
)) {
2711 css_put(&memcg
->css
);
2716 if (oom
&& !nr_oom_retries
) {
2718 nr_oom_retries
= MEM_CGROUP_RECLAIM_RETRIES
;
2721 ret
= mem_cgroup_do_charge(memcg
, gfp_mask
, batch
, nr_pages
,
2726 case CHARGE_RETRY
: /* not in OOM situation but retry */
2728 css_put(&memcg
->css
);
2731 case CHARGE_WOULDBLOCK
: /* !__GFP_WAIT */
2732 css_put(&memcg
->css
);
2734 case CHARGE_NOMEM
: /* OOM routine works */
2736 css_put(&memcg
->css
);
2739 /* If oom, we never return -ENOMEM */
2742 case CHARGE_OOM_DIE
: /* Killed by OOM Killer */
2743 css_put(&memcg
->css
);
2746 } while (ret
!= CHARGE_OK
);
2748 if (batch
> nr_pages
)
2749 refill_stock(memcg
, batch
- nr_pages
);
2750 css_put(&memcg
->css
);
2758 *ptr
= root_mem_cgroup
;
2763 * Somemtimes we have to undo a charge we got by try_charge().
2764 * This function is for that and do uncharge, put css's refcnt.
2765 * gotten by try_charge().
2767 static void __mem_cgroup_cancel_charge(struct mem_cgroup
*memcg
,
2768 unsigned int nr_pages
)
2770 if (!mem_cgroup_is_root(memcg
)) {
2771 unsigned long bytes
= nr_pages
* PAGE_SIZE
;
2773 res_counter_uncharge(&memcg
->res
, bytes
);
2774 if (do_swap_account
)
2775 res_counter_uncharge(&memcg
->memsw
, bytes
);
2780 * Cancel chrages in this cgroup....doesn't propagate to parent cgroup.
2781 * This is useful when moving usage to parent cgroup.
2783 static void __mem_cgroup_cancel_local_charge(struct mem_cgroup
*memcg
,
2784 unsigned int nr_pages
)
2786 unsigned long bytes
= nr_pages
* PAGE_SIZE
;
2788 if (mem_cgroup_is_root(memcg
))
2791 res_counter_uncharge_until(&memcg
->res
, memcg
->res
.parent
, bytes
);
2792 if (do_swap_account
)
2793 res_counter_uncharge_until(&memcg
->memsw
,
2794 memcg
->memsw
.parent
, bytes
);
2798 * A helper function to get mem_cgroup from ID. must be called under
2799 * rcu_read_lock(). The caller is responsible for calling css_tryget if
2800 * the mem_cgroup is used for charging. (dropping refcnt from swap can be
2801 * called against removed memcg.)
2803 static struct mem_cgroup
*mem_cgroup_lookup(unsigned short id
)
2805 struct cgroup_subsys_state
*css
;
2807 /* ID 0 is unused ID */
2810 css
= css_lookup(&mem_cgroup_subsys
, id
);
2813 return mem_cgroup_from_css(css
);
2816 struct mem_cgroup
*try_get_mem_cgroup_from_page(struct page
*page
)
2818 struct mem_cgroup
*memcg
= NULL
;
2819 struct page_cgroup
*pc
;
2823 VM_BUG_ON(!PageLocked(page
));
2825 pc
= lookup_page_cgroup(page
);
2826 lock_page_cgroup(pc
);
2827 if (PageCgroupUsed(pc
)) {
2828 memcg
= pc
->mem_cgroup
;
2829 if (memcg
&& !css_tryget(&memcg
->css
))
2831 } else if (PageSwapCache(page
)) {
2832 ent
.val
= page_private(page
);
2833 id
= lookup_swap_cgroup_id(ent
);
2835 memcg
= mem_cgroup_lookup(id
);
2836 if (memcg
&& !css_tryget(&memcg
->css
))
2840 unlock_page_cgroup(pc
);
2844 static void __mem_cgroup_commit_charge(struct mem_cgroup
*memcg
,
2846 unsigned int nr_pages
,
2847 enum charge_type ctype
,
2850 struct page_cgroup
*pc
= lookup_page_cgroup(page
);
2851 struct zone
*uninitialized_var(zone
);
2852 struct lruvec
*lruvec
;
2853 bool was_on_lru
= false;
2856 lock_page_cgroup(pc
);
2857 VM_BUG_ON(PageCgroupUsed(pc
));
2859 * we don't need page_cgroup_lock about tail pages, becase they are not
2860 * accessed by any other context at this point.
2864 * In some cases, SwapCache and FUSE(splice_buf->radixtree), the page
2865 * may already be on some other mem_cgroup's LRU. Take care of it.
2868 zone
= page_zone(page
);
2869 spin_lock_irq(&zone
->lru_lock
);
2870 if (PageLRU(page
)) {
2871 lruvec
= mem_cgroup_zone_lruvec(zone
, pc
->mem_cgroup
);
2873 del_page_from_lru_list(page
, lruvec
, page_lru(page
));
2878 pc
->mem_cgroup
= memcg
;
2880 * We access a page_cgroup asynchronously without lock_page_cgroup().
2881 * Especially when a page_cgroup is taken from a page, pc->mem_cgroup
2882 * is accessed after testing USED bit. To make pc->mem_cgroup visible
2883 * before USED bit, we need memory barrier here.
2884 * See mem_cgroup_add_lru_list(), etc.
2887 SetPageCgroupUsed(pc
);
2891 lruvec
= mem_cgroup_zone_lruvec(zone
, pc
->mem_cgroup
);
2892 VM_BUG_ON(PageLRU(page
));
2894 add_page_to_lru_list(page
, lruvec
, page_lru(page
));
2896 spin_unlock_irq(&zone
->lru_lock
);
2899 if (ctype
== MEM_CGROUP_CHARGE_TYPE_ANON
)
2904 mem_cgroup_charge_statistics(memcg
, page
, anon
, nr_pages
);
2905 unlock_page_cgroup(pc
);
2908 * "charge_statistics" updated event counter. Then, check it.
2909 * Insert ancestor (and ancestor's ancestors), to softlimit RB-tree.
2910 * if they exceeds softlimit.
2912 memcg_check_events(memcg
, page
);
2915 static DEFINE_MUTEX(set_limit_mutex
);
2917 #ifdef CONFIG_MEMCG_KMEM
2918 static inline bool memcg_can_account_kmem(struct mem_cgroup
*memcg
)
2920 return !mem_cgroup_disabled() && !mem_cgroup_is_root(memcg
) &&
2921 (memcg
->kmem_account_flags
& KMEM_ACCOUNTED_MASK
);
2925 * This is a bit cumbersome, but it is rarely used and avoids a backpointer
2926 * in the memcg_cache_params struct.
2928 static struct kmem_cache
*memcg_params_to_cache(struct memcg_cache_params
*p
)
2930 struct kmem_cache
*cachep
;
2932 VM_BUG_ON(p
->is_root_cache
);
2933 cachep
= p
->root_cache
;
2934 return cachep
->memcg_params
->memcg_caches
[memcg_cache_id(p
->memcg
)];
2937 #ifdef CONFIG_SLABINFO
2938 static int mem_cgroup_slabinfo_read(struct cgroup_subsys_state
*css
,
2939 struct cftype
*cft
, struct seq_file
*m
)
2941 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
2942 struct memcg_cache_params
*params
;
2944 if (!memcg_can_account_kmem(memcg
))
2947 print_slabinfo_header(m
);
2949 mutex_lock(&memcg
->slab_caches_mutex
);
2950 list_for_each_entry(params
, &memcg
->memcg_slab_caches
, list
)
2951 cache_show(memcg_params_to_cache(params
), m
);
2952 mutex_unlock(&memcg
->slab_caches_mutex
);
2958 static int memcg_charge_kmem(struct mem_cgroup
*memcg
, gfp_t gfp
, u64 size
)
2960 struct res_counter
*fail_res
;
2961 struct mem_cgroup
*_memcg
;
2965 ret
= res_counter_charge(&memcg
->kmem
, size
, &fail_res
);
2970 * Conditions under which we can wait for the oom_killer. Those are
2971 * the same conditions tested by the core page allocator
2973 may_oom
= (gfp
& __GFP_FS
) && !(gfp
& __GFP_NORETRY
);
2976 ret
= __mem_cgroup_try_charge(NULL
, gfp
, size
>> PAGE_SHIFT
,
2979 if (ret
== -EINTR
) {
2981 * __mem_cgroup_try_charge() chosed to bypass to root due to
2982 * OOM kill or fatal signal. Since our only options are to
2983 * either fail the allocation or charge it to this cgroup, do
2984 * it as a temporary condition. But we can't fail. From a
2985 * kmem/slab perspective, the cache has already been selected,
2986 * by mem_cgroup_kmem_get_cache(), so it is too late to change
2989 * This condition will only trigger if the task entered
2990 * memcg_charge_kmem in a sane state, but was OOM-killed during
2991 * __mem_cgroup_try_charge() above. Tasks that were already
2992 * dying when the allocation triggers should have been already
2993 * directed to the root cgroup in memcontrol.h
2995 res_counter_charge_nofail(&memcg
->res
, size
, &fail_res
);
2996 if (do_swap_account
)
2997 res_counter_charge_nofail(&memcg
->memsw
, size
,
3001 res_counter_uncharge(&memcg
->kmem
, size
);
3006 static void memcg_uncharge_kmem(struct mem_cgroup
*memcg
, u64 size
)
3008 res_counter_uncharge(&memcg
->res
, size
);
3009 if (do_swap_account
)
3010 res_counter_uncharge(&memcg
->memsw
, size
);
3013 if (res_counter_uncharge(&memcg
->kmem
, size
))
3017 * Releases a reference taken in kmem_cgroup_css_offline in case
3018 * this last uncharge is racing with the offlining code or it is
3019 * outliving the memcg existence.
3021 * The memory barrier imposed by test&clear is paired with the
3022 * explicit one in memcg_kmem_mark_dead().
3024 if (memcg_kmem_test_and_clear_dead(memcg
))
3025 css_put(&memcg
->css
);
3028 void memcg_cache_list_add(struct mem_cgroup
*memcg
, struct kmem_cache
*cachep
)
3033 mutex_lock(&memcg
->slab_caches_mutex
);
3034 list_add(&cachep
->memcg_params
->list
, &memcg
->memcg_slab_caches
);
3035 mutex_unlock(&memcg
->slab_caches_mutex
);
3039 * helper for acessing a memcg's index. It will be used as an index in the
3040 * child cache array in kmem_cache, and also to derive its name. This function
3041 * will return -1 when this is not a kmem-limited memcg.
3043 int memcg_cache_id(struct mem_cgroup
*memcg
)
3045 return memcg
? memcg
->kmemcg_id
: -1;
3049 * This ends up being protected by the set_limit mutex, during normal
3050 * operation, because that is its main call site.
3052 * But when we create a new cache, we can call this as well if its parent
3053 * is kmem-limited. That will have to hold set_limit_mutex as well.
3055 int memcg_update_cache_sizes(struct mem_cgroup
*memcg
)
3059 num
= ida_simple_get(&kmem_limited_groups
,
3060 0, MEMCG_CACHES_MAX_SIZE
, GFP_KERNEL
);
3064 * After this point, kmem_accounted (that we test atomically in
3065 * the beginning of this conditional), is no longer 0. This
3066 * guarantees only one process will set the following boolean
3067 * to true. We don't need test_and_set because we're protected
3068 * by the set_limit_mutex anyway.
3070 memcg_kmem_set_activated(memcg
);
3072 ret
= memcg_update_all_caches(num
+1);
3074 ida_simple_remove(&kmem_limited_groups
, num
);
3075 memcg_kmem_clear_activated(memcg
);
3079 memcg
->kmemcg_id
= num
;
3080 INIT_LIST_HEAD(&memcg
->memcg_slab_caches
);
3081 mutex_init(&memcg
->slab_caches_mutex
);
3085 static size_t memcg_caches_array_size(int num_groups
)
3088 if (num_groups
<= 0)
3091 size
= 2 * num_groups
;
3092 if (size
< MEMCG_CACHES_MIN_SIZE
)
3093 size
= MEMCG_CACHES_MIN_SIZE
;
3094 else if (size
> MEMCG_CACHES_MAX_SIZE
)
3095 size
= MEMCG_CACHES_MAX_SIZE
;
3101 * We should update the current array size iff all caches updates succeed. This
3102 * can only be done from the slab side. The slab mutex needs to be held when
3105 void memcg_update_array_size(int num
)
3107 if (num
> memcg_limited_groups_array_size
)
3108 memcg_limited_groups_array_size
= memcg_caches_array_size(num
);
3111 static void kmem_cache_destroy_work_func(struct work_struct
*w
);
3113 int memcg_update_cache_size(struct kmem_cache
*s
, int num_groups
)
3115 struct memcg_cache_params
*cur_params
= s
->memcg_params
;
3117 VM_BUG_ON(s
->memcg_params
&& !s
->memcg_params
->is_root_cache
);
3119 if (num_groups
> memcg_limited_groups_array_size
) {
3121 ssize_t size
= memcg_caches_array_size(num_groups
);
3123 size
*= sizeof(void *);
3124 size
+= sizeof(struct memcg_cache_params
);
3126 s
->memcg_params
= kzalloc(size
, GFP_KERNEL
);
3127 if (!s
->memcg_params
) {
3128 s
->memcg_params
= cur_params
;
3132 s
->memcg_params
->is_root_cache
= true;
3135 * There is the chance it will be bigger than
3136 * memcg_limited_groups_array_size, if we failed an allocation
3137 * in a cache, in which case all caches updated before it, will
3138 * have a bigger array.
3140 * But if that is the case, the data after
3141 * memcg_limited_groups_array_size is certainly unused
3143 for (i
= 0; i
< memcg_limited_groups_array_size
; i
++) {
3144 if (!cur_params
->memcg_caches
[i
])
3146 s
->memcg_params
->memcg_caches
[i
] =
3147 cur_params
->memcg_caches
[i
];
3151 * Ideally, we would wait until all caches succeed, and only
3152 * then free the old one. But this is not worth the extra
3153 * pointer per-cache we'd have to have for this.
3155 * It is not a big deal if some caches are left with a size
3156 * bigger than the others. And all updates will reset this
3164 int memcg_register_cache(struct mem_cgroup
*memcg
, struct kmem_cache
*s
,
3165 struct kmem_cache
*root_cache
)
3167 size_t size
= sizeof(struct memcg_cache_params
);
3169 if (!memcg_kmem_enabled())
3173 size
+= memcg_limited_groups_array_size
* sizeof(void *);
3175 s
->memcg_params
= kzalloc(size
, GFP_KERNEL
);
3176 if (!s
->memcg_params
)
3180 s
->memcg_params
->memcg
= memcg
;
3181 s
->memcg_params
->root_cache
= root_cache
;
3182 INIT_WORK(&s
->memcg_params
->destroy
,
3183 kmem_cache_destroy_work_func
);
3185 s
->memcg_params
->is_root_cache
= true;
3190 void memcg_release_cache(struct kmem_cache
*s
)
3192 struct kmem_cache
*root
;
3193 struct mem_cgroup
*memcg
;
3197 * This happens, for instance, when a root cache goes away before we
3200 if (!s
->memcg_params
)
3203 if (s
->memcg_params
->is_root_cache
)
3206 memcg
= s
->memcg_params
->memcg
;
3207 id
= memcg_cache_id(memcg
);
3209 root
= s
->memcg_params
->root_cache
;
3210 root
->memcg_params
->memcg_caches
[id
] = NULL
;
3212 mutex_lock(&memcg
->slab_caches_mutex
);
3213 list_del(&s
->memcg_params
->list
);
3214 mutex_unlock(&memcg
->slab_caches_mutex
);
3216 css_put(&memcg
->css
);
3218 kfree(s
->memcg_params
);
3222 * During the creation a new cache, we need to disable our accounting mechanism
3223 * altogether. This is true even if we are not creating, but rather just
3224 * enqueing new caches to be created.
3226 * This is because that process will trigger allocations; some visible, like
3227 * explicit kmallocs to auxiliary data structures, name strings and internal
3228 * cache structures; some well concealed, like INIT_WORK() that can allocate
3229 * objects during debug.
3231 * If any allocation happens during memcg_kmem_get_cache, we will recurse back
3232 * to it. This may not be a bounded recursion: since the first cache creation
3233 * failed to complete (waiting on the allocation), we'll just try to create the
3234 * cache again, failing at the same point.
3236 * memcg_kmem_get_cache is prepared to abort after seeing a positive count of
3237 * memcg_kmem_skip_account. So we enclose anything that might allocate memory
3238 * inside the following two functions.
3240 static inline void memcg_stop_kmem_account(void)
3242 VM_BUG_ON(!current
->mm
);
3243 current
->memcg_kmem_skip_account
++;
3246 static inline void memcg_resume_kmem_account(void)
3248 VM_BUG_ON(!current
->mm
);
3249 current
->memcg_kmem_skip_account
--;
3252 static void kmem_cache_destroy_work_func(struct work_struct
*w
)
3254 struct kmem_cache
*cachep
;
3255 struct memcg_cache_params
*p
;
3257 p
= container_of(w
, struct memcg_cache_params
, destroy
);
3259 cachep
= memcg_params_to_cache(p
);
3262 * If we get down to 0 after shrink, we could delete right away.
3263 * However, memcg_release_pages() already puts us back in the workqueue
3264 * in that case. If we proceed deleting, we'll get a dangling
3265 * reference, and removing the object from the workqueue in that case
3266 * is unnecessary complication. We are not a fast path.
3268 * Note that this case is fundamentally different from racing with
3269 * shrink_slab(): if memcg_cgroup_destroy_cache() is called in
3270 * kmem_cache_shrink, not only we would be reinserting a dead cache
3271 * into the queue, but doing so from inside the worker racing to
3274 * So if we aren't down to zero, we'll just schedule a worker and try
3277 if (atomic_read(&cachep
->memcg_params
->nr_pages
) != 0) {
3278 kmem_cache_shrink(cachep
);
3279 if (atomic_read(&cachep
->memcg_params
->nr_pages
) == 0)
3282 kmem_cache_destroy(cachep
);
3285 void mem_cgroup_destroy_cache(struct kmem_cache
*cachep
)
3287 if (!cachep
->memcg_params
->dead
)
3291 * There are many ways in which we can get here.
3293 * We can get to a memory-pressure situation while the delayed work is
3294 * still pending to run. The vmscan shrinkers can then release all
3295 * cache memory and get us to destruction. If this is the case, we'll
3296 * be executed twice, which is a bug (the second time will execute over
3297 * bogus data). In this case, cancelling the work should be fine.
3299 * But we can also get here from the worker itself, if
3300 * kmem_cache_shrink is enough to shake all the remaining objects and
3301 * get the page count to 0. In this case, we'll deadlock if we try to
3302 * cancel the work (the worker runs with an internal lock held, which
3303 * is the same lock we would hold for cancel_work_sync().)
3305 * Since we can't possibly know who got us here, just refrain from
3306 * running if there is already work pending
3308 if (work_pending(&cachep
->memcg_params
->destroy
))
3311 * We have to defer the actual destroying to a workqueue, because
3312 * we might currently be in a context that cannot sleep.
3314 schedule_work(&cachep
->memcg_params
->destroy
);
3318 * This lock protects updaters, not readers. We want readers to be as fast as
3319 * they can, and they will either see NULL or a valid cache value. Our model
3320 * allow them to see NULL, in which case the root memcg will be selected.
3322 * We need this lock because multiple allocations to the same cache from a non
3323 * will span more than one worker. Only one of them can create the cache.
3325 static DEFINE_MUTEX(memcg_cache_mutex
);
3328 * Called with memcg_cache_mutex held
3330 static struct kmem_cache
*kmem_cache_dup(struct mem_cgroup
*memcg
,
3331 struct kmem_cache
*s
)
3333 struct kmem_cache
*new;
3334 static char *tmp_name
= NULL
;
3336 lockdep_assert_held(&memcg_cache_mutex
);
3339 * kmem_cache_create_memcg duplicates the given name and
3340 * cgroup_name for this name requires RCU context.
3341 * This static temporary buffer is used to prevent from
3342 * pointless shortliving allocation.
3345 tmp_name
= kmalloc(PATH_MAX
, GFP_KERNEL
);
3351 snprintf(tmp_name
, PATH_MAX
, "%s(%d:%s)", s
->name
,
3352 memcg_cache_id(memcg
), cgroup_name(memcg
->css
.cgroup
));
3355 new = kmem_cache_create_memcg(memcg
, tmp_name
, s
->object_size
, s
->align
,
3356 (s
->flags
& ~SLAB_PANIC
), s
->ctor
, s
);
3359 new->allocflags
|= __GFP_KMEMCG
;
3364 static struct kmem_cache
*memcg_create_kmem_cache(struct mem_cgroup
*memcg
,
3365 struct kmem_cache
*cachep
)
3367 struct kmem_cache
*new_cachep
;
3370 BUG_ON(!memcg_can_account_kmem(memcg
));
3372 idx
= memcg_cache_id(memcg
);
3374 mutex_lock(&memcg_cache_mutex
);
3375 new_cachep
= cachep
->memcg_params
->memcg_caches
[idx
];
3377 css_put(&memcg
->css
);
3381 new_cachep
= kmem_cache_dup(memcg
, cachep
);
3382 if (new_cachep
== NULL
) {
3383 new_cachep
= cachep
;
3384 css_put(&memcg
->css
);
3388 atomic_set(&new_cachep
->memcg_params
->nr_pages
, 0);
3390 cachep
->memcg_params
->memcg_caches
[idx
] = new_cachep
;
3392 * the readers won't lock, make sure everybody sees the updated value,
3393 * so they won't put stuff in the queue again for no reason
3397 mutex_unlock(&memcg_cache_mutex
);
3401 void kmem_cache_destroy_memcg_children(struct kmem_cache
*s
)
3403 struct kmem_cache
*c
;
3406 if (!s
->memcg_params
)
3408 if (!s
->memcg_params
->is_root_cache
)
3412 * If the cache is being destroyed, we trust that there is no one else
3413 * requesting objects from it. Even if there are, the sanity checks in
3414 * kmem_cache_destroy should caught this ill-case.
3416 * Still, we don't want anyone else freeing memcg_caches under our
3417 * noses, which can happen if a new memcg comes to life. As usual,
3418 * we'll take the set_limit_mutex to protect ourselves against this.
3420 mutex_lock(&set_limit_mutex
);
3421 for (i
= 0; i
< memcg_limited_groups_array_size
; i
++) {
3422 c
= s
->memcg_params
->memcg_caches
[i
];
3427 * We will now manually delete the caches, so to avoid races
3428 * we need to cancel all pending destruction workers and
3429 * proceed with destruction ourselves.
3431 * kmem_cache_destroy() will call kmem_cache_shrink internally,
3432 * and that could spawn the workers again: it is likely that
3433 * the cache still have active pages until this very moment.
3434 * This would lead us back to mem_cgroup_destroy_cache.
3436 * But that will not execute at all if the "dead" flag is not
3437 * set, so flip it down to guarantee we are in control.
3439 c
->memcg_params
->dead
= false;
3440 cancel_work_sync(&c
->memcg_params
->destroy
);
3441 kmem_cache_destroy(c
);
3443 mutex_unlock(&set_limit_mutex
);
3446 struct create_work
{
3447 struct mem_cgroup
*memcg
;
3448 struct kmem_cache
*cachep
;
3449 struct work_struct work
;
3452 static void mem_cgroup_destroy_all_caches(struct mem_cgroup
*memcg
)
3454 struct kmem_cache
*cachep
;
3455 struct memcg_cache_params
*params
;
3457 if (!memcg_kmem_is_active(memcg
))
3460 mutex_lock(&memcg
->slab_caches_mutex
);
3461 list_for_each_entry(params
, &memcg
->memcg_slab_caches
, list
) {
3462 cachep
= memcg_params_to_cache(params
);
3463 cachep
->memcg_params
->dead
= true;
3464 schedule_work(&cachep
->memcg_params
->destroy
);
3466 mutex_unlock(&memcg
->slab_caches_mutex
);
3469 static void memcg_create_cache_work_func(struct work_struct
*w
)
3471 struct create_work
*cw
;
3473 cw
= container_of(w
, struct create_work
, work
);
3474 memcg_create_kmem_cache(cw
->memcg
, cw
->cachep
);
3479 * Enqueue the creation of a per-memcg kmem_cache.
3481 static void __memcg_create_cache_enqueue(struct mem_cgroup
*memcg
,
3482 struct kmem_cache
*cachep
)
3484 struct create_work
*cw
;
3486 cw
= kmalloc(sizeof(struct create_work
), GFP_NOWAIT
);
3488 css_put(&memcg
->css
);
3493 cw
->cachep
= cachep
;
3495 INIT_WORK(&cw
->work
, memcg_create_cache_work_func
);
3496 schedule_work(&cw
->work
);
3499 static void memcg_create_cache_enqueue(struct mem_cgroup
*memcg
,
3500 struct kmem_cache
*cachep
)
3503 * We need to stop accounting when we kmalloc, because if the
3504 * corresponding kmalloc cache is not yet created, the first allocation
3505 * in __memcg_create_cache_enqueue will recurse.
3507 * However, it is better to enclose the whole function. Depending on
3508 * the debugging options enabled, INIT_WORK(), for instance, can
3509 * trigger an allocation. This too, will make us recurse. Because at
3510 * this point we can't allow ourselves back into memcg_kmem_get_cache,
3511 * the safest choice is to do it like this, wrapping the whole function.
3513 memcg_stop_kmem_account();
3514 __memcg_create_cache_enqueue(memcg
, cachep
);
3515 memcg_resume_kmem_account();
3518 * Return the kmem_cache we're supposed to use for a slab allocation.
3519 * We try to use the current memcg's version of the cache.
3521 * If the cache does not exist yet, if we are the first user of it,
3522 * we either create it immediately, if possible, or create it asynchronously
3524 * In the latter case, we will let the current allocation go through with
3525 * the original cache.
3527 * Can't be called in interrupt context or from kernel threads.
3528 * This function needs to be called with rcu_read_lock() held.
3530 struct kmem_cache
*__memcg_kmem_get_cache(struct kmem_cache
*cachep
,
3533 struct mem_cgroup
*memcg
;
3536 VM_BUG_ON(!cachep
->memcg_params
);
3537 VM_BUG_ON(!cachep
->memcg_params
->is_root_cache
);
3539 if (!current
->mm
|| current
->memcg_kmem_skip_account
)
3543 memcg
= mem_cgroup_from_task(rcu_dereference(current
->mm
->owner
));
3545 if (!memcg_can_account_kmem(memcg
))
3548 idx
= memcg_cache_id(memcg
);
3551 * barrier to mare sure we're always seeing the up to date value. The
3552 * code updating memcg_caches will issue a write barrier to match this.
3554 read_barrier_depends();
3555 if (likely(cachep
->memcg_params
->memcg_caches
[idx
])) {
3556 cachep
= cachep
->memcg_params
->memcg_caches
[idx
];
3560 /* The corresponding put will be done in the workqueue. */
3561 if (!css_tryget(&memcg
->css
))
3566 * If we are in a safe context (can wait, and not in interrupt
3567 * context), we could be be predictable and return right away.
3568 * This would guarantee that the allocation being performed
3569 * already belongs in the new cache.
3571 * However, there are some clashes that can arrive from locking.
3572 * For instance, because we acquire the slab_mutex while doing
3573 * kmem_cache_dup, this means no further allocation could happen
3574 * with the slab_mutex held.
3576 * Also, because cache creation issue get_online_cpus(), this
3577 * creates a lock chain: memcg_slab_mutex -> cpu_hotplug_mutex,
3578 * that ends up reversed during cpu hotplug. (cpuset allocates
3579 * a bunch of GFP_KERNEL memory during cpuup). Due to all that,
3580 * better to defer everything.
3582 memcg_create_cache_enqueue(memcg
, cachep
);
3588 EXPORT_SYMBOL(__memcg_kmem_get_cache
);
3591 * We need to verify if the allocation against current->mm->owner's memcg is
3592 * possible for the given order. But the page is not allocated yet, so we'll
3593 * need a further commit step to do the final arrangements.
3595 * It is possible for the task to switch cgroups in this mean time, so at
3596 * commit time, we can't rely on task conversion any longer. We'll then use
3597 * the handle argument to return to the caller which cgroup we should commit
3598 * against. We could also return the memcg directly and avoid the pointer
3599 * passing, but a boolean return value gives better semantics considering
3600 * the compiled-out case as well.
3602 * Returning true means the allocation is possible.
3605 __memcg_kmem_newpage_charge(gfp_t gfp
, struct mem_cgroup
**_memcg
, int order
)
3607 struct mem_cgroup
*memcg
;
3613 * Disabling accounting is only relevant for some specific memcg
3614 * internal allocations. Therefore we would initially not have such
3615 * check here, since direct calls to the page allocator that are marked
3616 * with GFP_KMEMCG only happen outside memcg core. We are mostly
3617 * concerned with cache allocations, and by having this test at
3618 * memcg_kmem_get_cache, we are already able to relay the allocation to
3619 * the root cache and bypass the memcg cache altogether.
3621 * There is one exception, though: the SLUB allocator does not create
3622 * large order caches, but rather service large kmallocs directly from
3623 * the page allocator. Therefore, the following sequence when backed by
3624 * the SLUB allocator:
3626 * memcg_stop_kmem_account();
3627 * kmalloc(<large_number>)
3628 * memcg_resume_kmem_account();
3630 * would effectively ignore the fact that we should skip accounting,
3631 * since it will drive us directly to this function without passing
3632 * through the cache selector memcg_kmem_get_cache. Such large
3633 * allocations are extremely rare but can happen, for instance, for the
3634 * cache arrays. We bring this test here.
3636 if (!current
->mm
|| current
->memcg_kmem_skip_account
)
3639 memcg
= try_get_mem_cgroup_from_mm(current
->mm
);
3642 * very rare case described in mem_cgroup_from_task. Unfortunately there
3643 * isn't much we can do without complicating this too much, and it would
3644 * be gfp-dependent anyway. Just let it go
3646 if (unlikely(!memcg
))
3649 if (!memcg_can_account_kmem(memcg
)) {
3650 css_put(&memcg
->css
);
3654 ret
= memcg_charge_kmem(memcg
, gfp
, PAGE_SIZE
<< order
);
3658 css_put(&memcg
->css
);
3662 void __memcg_kmem_commit_charge(struct page
*page
, struct mem_cgroup
*memcg
,
3665 struct page_cgroup
*pc
;
3667 VM_BUG_ON(mem_cgroup_is_root(memcg
));
3669 /* The page allocation failed. Revert */
3671 memcg_uncharge_kmem(memcg
, PAGE_SIZE
<< order
);
3675 pc
= lookup_page_cgroup(page
);
3676 lock_page_cgroup(pc
);
3677 pc
->mem_cgroup
= memcg
;
3678 SetPageCgroupUsed(pc
);
3679 unlock_page_cgroup(pc
);
3682 void __memcg_kmem_uncharge_pages(struct page
*page
, int order
)
3684 struct mem_cgroup
*memcg
= NULL
;
3685 struct page_cgroup
*pc
;
3688 pc
= lookup_page_cgroup(page
);
3690 * Fast unlocked return. Theoretically might have changed, have to
3691 * check again after locking.
3693 if (!PageCgroupUsed(pc
))
3696 lock_page_cgroup(pc
);
3697 if (PageCgroupUsed(pc
)) {
3698 memcg
= pc
->mem_cgroup
;
3699 ClearPageCgroupUsed(pc
);
3701 unlock_page_cgroup(pc
);
3704 * We trust that only if there is a memcg associated with the page, it
3705 * is a valid allocation
3710 VM_BUG_ON(mem_cgroup_is_root(memcg
));
3711 memcg_uncharge_kmem(memcg
, PAGE_SIZE
<< order
);
3714 static inline void mem_cgroup_destroy_all_caches(struct mem_cgroup
*memcg
)
3717 #endif /* CONFIG_MEMCG_KMEM */
3719 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
3721 #define PCGF_NOCOPY_AT_SPLIT (1 << PCG_LOCK | 1 << PCG_MIGRATION)
3723 * Because tail pages are not marked as "used", set it. We're under
3724 * zone->lru_lock, 'splitting on pmd' and compound_lock.
3725 * charge/uncharge will be never happen and move_account() is done under
3726 * compound_lock(), so we don't have to take care of races.
3728 void mem_cgroup_split_huge_fixup(struct page
*head
)
3730 struct page_cgroup
*head_pc
= lookup_page_cgroup(head
);
3731 struct page_cgroup
*pc
;
3732 struct mem_cgroup
*memcg
;
3735 if (mem_cgroup_disabled())
3738 memcg
= head_pc
->mem_cgroup
;
3739 for (i
= 1; i
< HPAGE_PMD_NR
; i
++) {
3741 pc
->mem_cgroup
= memcg
;
3742 smp_wmb();/* see __commit_charge() */
3743 pc
->flags
= head_pc
->flags
& ~PCGF_NOCOPY_AT_SPLIT
;
3745 __this_cpu_sub(memcg
->stat
->count
[MEM_CGROUP_STAT_RSS_HUGE
],
3748 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
3751 * mem_cgroup_move_account - move account of the page
3753 * @nr_pages: number of regular pages (>1 for huge pages)
3754 * @pc: page_cgroup of the page.
3755 * @from: mem_cgroup which the page is moved from.
3756 * @to: mem_cgroup which the page is moved to. @from != @to.
3758 * The caller must confirm following.
3759 * - page is not on LRU (isolate_page() is useful.)
3760 * - compound_lock is held when nr_pages > 1
3762 * This function doesn't do "charge" to new cgroup and doesn't do "uncharge"
3765 static int mem_cgroup_move_account(struct page
*page
,
3766 unsigned int nr_pages
,
3767 struct page_cgroup
*pc
,
3768 struct mem_cgroup
*from
,
3769 struct mem_cgroup
*to
)
3771 unsigned long flags
;
3773 bool anon
= PageAnon(page
);
3775 VM_BUG_ON(from
== to
);
3776 VM_BUG_ON(PageLRU(page
));
3778 * The page is isolated from LRU. So, collapse function
3779 * will not handle this page. But page splitting can happen.
3780 * Do this check under compound_page_lock(). The caller should
3784 if (nr_pages
> 1 && !PageTransHuge(page
))
3787 lock_page_cgroup(pc
);
3790 if (!PageCgroupUsed(pc
) || pc
->mem_cgroup
!= from
)
3793 move_lock_mem_cgroup(from
, &flags
);
3795 if (!anon
&& page_mapped(page
)) {
3796 /* Update mapped_file data for mem_cgroup */
3798 __this_cpu_dec(from
->stat
->count
[MEM_CGROUP_STAT_FILE_MAPPED
]);
3799 __this_cpu_inc(to
->stat
->count
[MEM_CGROUP_STAT_FILE_MAPPED
]);
3802 mem_cgroup_charge_statistics(from
, page
, anon
, -nr_pages
);
3804 /* caller should have done css_get */
3805 pc
->mem_cgroup
= to
;
3806 mem_cgroup_charge_statistics(to
, page
, anon
, nr_pages
);
3807 move_unlock_mem_cgroup(from
, &flags
);
3810 unlock_page_cgroup(pc
);
3814 memcg_check_events(to
, page
);
3815 memcg_check_events(from
, page
);
3821 * mem_cgroup_move_parent - moves page to the parent group
3822 * @page: the page to move
3823 * @pc: page_cgroup of the page
3824 * @child: page's cgroup
3826 * move charges to its parent or the root cgroup if the group has no
3827 * parent (aka use_hierarchy==0).
3828 * Although this might fail (get_page_unless_zero, isolate_lru_page or
3829 * mem_cgroup_move_account fails) the failure is always temporary and
3830 * it signals a race with a page removal/uncharge or migration. In the
3831 * first case the page is on the way out and it will vanish from the LRU
3832 * on the next attempt and the call should be retried later.
3833 * Isolation from the LRU fails only if page has been isolated from
3834 * the LRU since we looked at it and that usually means either global
3835 * reclaim or migration going on. The page will either get back to the
3837 * Finaly mem_cgroup_move_account fails only if the page got uncharged
3838 * (!PageCgroupUsed) or moved to a different group. The page will
3839 * disappear in the next attempt.
3841 static int mem_cgroup_move_parent(struct page
*page
,
3842 struct page_cgroup
*pc
,
3843 struct mem_cgroup
*child
)
3845 struct mem_cgroup
*parent
;
3846 unsigned int nr_pages
;
3847 unsigned long uninitialized_var(flags
);
3850 VM_BUG_ON(mem_cgroup_is_root(child
));
3853 if (!get_page_unless_zero(page
))
3855 if (isolate_lru_page(page
))
3858 nr_pages
= hpage_nr_pages(page
);
3860 parent
= parent_mem_cgroup(child
);
3862 * If no parent, move charges to root cgroup.
3865 parent
= root_mem_cgroup
;
3868 VM_BUG_ON(!PageTransHuge(page
));
3869 flags
= compound_lock_irqsave(page
);
3872 ret
= mem_cgroup_move_account(page
, nr_pages
,
3875 __mem_cgroup_cancel_local_charge(child
, nr_pages
);
3878 compound_unlock_irqrestore(page
, flags
);
3879 putback_lru_page(page
);
3887 * Charge the memory controller for page usage.
3889 * 0 if the charge was successful
3890 * < 0 if the cgroup is over its limit
3892 static int mem_cgroup_charge_common(struct page
*page
, struct mm_struct
*mm
,
3893 gfp_t gfp_mask
, enum charge_type ctype
)
3895 struct mem_cgroup
*memcg
= NULL
;
3896 unsigned int nr_pages
= 1;
3900 if (PageTransHuge(page
)) {
3901 nr_pages
<<= compound_order(page
);
3902 VM_BUG_ON(!PageTransHuge(page
));
3904 * Never OOM-kill a process for a huge page. The
3905 * fault handler will fall back to regular pages.
3910 ret
= __mem_cgroup_try_charge(mm
, gfp_mask
, nr_pages
, &memcg
, oom
);
3913 __mem_cgroup_commit_charge(memcg
, page
, nr_pages
, ctype
, false);
3917 int mem_cgroup_newpage_charge(struct page
*page
,
3918 struct mm_struct
*mm
, gfp_t gfp_mask
)
3920 if (mem_cgroup_disabled())
3922 VM_BUG_ON(page_mapped(page
));
3923 VM_BUG_ON(page
->mapping
&& !PageAnon(page
));
3925 return mem_cgroup_charge_common(page
, mm
, gfp_mask
,
3926 MEM_CGROUP_CHARGE_TYPE_ANON
);
3930 * While swap-in, try_charge -> commit or cancel, the page is locked.
3931 * And when try_charge() successfully returns, one refcnt to memcg without
3932 * struct page_cgroup is acquired. This refcnt will be consumed by
3933 * "commit()" or removed by "cancel()"
3935 static int __mem_cgroup_try_charge_swapin(struct mm_struct
*mm
,
3938 struct mem_cgroup
**memcgp
)
3940 struct mem_cgroup
*memcg
;
3941 struct page_cgroup
*pc
;
3944 pc
= lookup_page_cgroup(page
);
3946 * Every swap fault against a single page tries to charge the
3947 * page, bail as early as possible. shmem_unuse() encounters
3948 * already charged pages, too. The USED bit is protected by
3949 * the page lock, which serializes swap cache removal, which
3950 * in turn serializes uncharging.
3952 if (PageCgroupUsed(pc
))
3954 if (!do_swap_account
)
3956 memcg
= try_get_mem_cgroup_from_page(page
);
3960 ret
= __mem_cgroup_try_charge(NULL
, mask
, 1, memcgp
, true);
3961 css_put(&memcg
->css
);
3966 ret
= __mem_cgroup_try_charge(mm
, mask
, 1, memcgp
, true);
3972 int mem_cgroup_try_charge_swapin(struct mm_struct
*mm
, struct page
*page
,
3973 gfp_t gfp_mask
, struct mem_cgroup
**memcgp
)
3976 if (mem_cgroup_disabled())
3979 * A racing thread's fault, or swapoff, may have already
3980 * updated the pte, and even removed page from swap cache: in
3981 * those cases unuse_pte()'s pte_same() test will fail; but
3982 * there's also a KSM case which does need to charge the page.
3984 if (!PageSwapCache(page
)) {
3987 ret
= __mem_cgroup_try_charge(mm
, gfp_mask
, 1, memcgp
, true);
3992 return __mem_cgroup_try_charge_swapin(mm
, page
, gfp_mask
, memcgp
);
3995 void mem_cgroup_cancel_charge_swapin(struct mem_cgroup
*memcg
)
3997 if (mem_cgroup_disabled())
4001 __mem_cgroup_cancel_charge(memcg
, 1);
4005 __mem_cgroup_commit_charge_swapin(struct page
*page
, struct mem_cgroup
*memcg
,
4006 enum charge_type ctype
)
4008 if (mem_cgroup_disabled())
4013 __mem_cgroup_commit_charge(memcg
, page
, 1, ctype
, true);
4015 * Now swap is on-memory. This means this page may be
4016 * counted both as mem and swap....double count.
4017 * Fix it by uncharging from memsw. Basically, this SwapCache is stable
4018 * under lock_page(). But in do_swap_page()::memory.c, reuse_swap_page()
4019 * may call delete_from_swap_cache() before reach here.
4021 if (do_swap_account
&& PageSwapCache(page
)) {
4022 swp_entry_t ent
= {.val
= page_private(page
)};
4023 mem_cgroup_uncharge_swap(ent
);
4027 void mem_cgroup_commit_charge_swapin(struct page
*page
,
4028 struct mem_cgroup
*memcg
)
4030 __mem_cgroup_commit_charge_swapin(page
, memcg
,
4031 MEM_CGROUP_CHARGE_TYPE_ANON
);
4034 int mem_cgroup_cache_charge(struct page
*page
, struct mm_struct
*mm
,
4037 struct mem_cgroup
*memcg
= NULL
;
4038 enum charge_type type
= MEM_CGROUP_CHARGE_TYPE_CACHE
;
4041 if (mem_cgroup_disabled())
4043 if (PageCompound(page
))
4046 if (!PageSwapCache(page
))
4047 ret
= mem_cgroup_charge_common(page
, mm
, gfp_mask
, type
);
4048 else { /* page is swapcache/shmem */
4049 ret
= __mem_cgroup_try_charge_swapin(mm
, page
,
4052 __mem_cgroup_commit_charge_swapin(page
, memcg
, type
);
4057 static void mem_cgroup_do_uncharge(struct mem_cgroup
*memcg
,
4058 unsigned int nr_pages
,
4059 const enum charge_type ctype
)
4061 struct memcg_batch_info
*batch
= NULL
;
4062 bool uncharge_memsw
= true;
4064 /* If swapout, usage of swap doesn't decrease */
4065 if (!do_swap_account
|| ctype
== MEM_CGROUP_CHARGE_TYPE_SWAPOUT
)
4066 uncharge_memsw
= false;
4068 batch
= ¤t
->memcg_batch
;
4070 * In usual, we do css_get() when we remember memcg pointer.
4071 * But in this case, we keep res->usage until end of a series of
4072 * uncharges. Then, it's ok to ignore memcg's refcnt.
4075 batch
->memcg
= memcg
;
4077 * do_batch > 0 when unmapping pages or inode invalidate/truncate.
4078 * In those cases, all pages freed continuously can be expected to be in
4079 * the same cgroup and we have chance to coalesce uncharges.
4080 * But we do uncharge one by one if this is killed by OOM(TIF_MEMDIE)
4081 * because we want to do uncharge as soon as possible.
4084 if (!batch
->do_batch
|| test_thread_flag(TIF_MEMDIE
))
4085 goto direct_uncharge
;
4088 goto direct_uncharge
;
4091 * In typical case, batch->memcg == mem. This means we can
4092 * merge a series of uncharges to an uncharge of res_counter.
4093 * If not, we uncharge res_counter ony by one.
4095 if (batch
->memcg
!= memcg
)
4096 goto direct_uncharge
;
4097 /* remember freed charge and uncharge it later */
4100 batch
->memsw_nr_pages
++;
4103 res_counter_uncharge(&memcg
->res
, nr_pages
* PAGE_SIZE
);
4105 res_counter_uncharge(&memcg
->memsw
, nr_pages
* PAGE_SIZE
);
4106 if (unlikely(batch
->memcg
!= memcg
))
4107 memcg_oom_recover(memcg
);
4111 * uncharge if !page_mapped(page)
4113 static struct mem_cgroup
*
4114 __mem_cgroup_uncharge_common(struct page
*page
, enum charge_type ctype
,
4117 struct mem_cgroup
*memcg
= NULL
;
4118 unsigned int nr_pages
= 1;
4119 struct page_cgroup
*pc
;
4122 if (mem_cgroup_disabled())
4125 if (PageTransHuge(page
)) {
4126 nr_pages
<<= compound_order(page
);
4127 VM_BUG_ON(!PageTransHuge(page
));
4130 * Check if our page_cgroup is valid
4132 pc
= lookup_page_cgroup(page
);
4133 if (unlikely(!PageCgroupUsed(pc
)))
4136 lock_page_cgroup(pc
);
4138 memcg
= pc
->mem_cgroup
;
4140 if (!PageCgroupUsed(pc
))
4143 anon
= PageAnon(page
);
4146 case MEM_CGROUP_CHARGE_TYPE_ANON
:
4148 * Generally PageAnon tells if it's the anon statistics to be
4149 * updated; but sometimes e.g. mem_cgroup_uncharge_page() is
4150 * used before page reached the stage of being marked PageAnon.
4154 case MEM_CGROUP_CHARGE_TYPE_DROP
:
4155 /* See mem_cgroup_prepare_migration() */
4156 if (page_mapped(page
))
4159 * Pages under migration may not be uncharged. But
4160 * end_migration() /must/ be the one uncharging the
4161 * unused post-migration page and so it has to call
4162 * here with the migration bit still set. See the
4163 * res_counter handling below.
4165 if (!end_migration
&& PageCgroupMigration(pc
))
4168 case MEM_CGROUP_CHARGE_TYPE_SWAPOUT
:
4169 if (!PageAnon(page
)) { /* Shared memory */
4170 if (page
->mapping
&& !page_is_file_cache(page
))
4172 } else if (page_mapped(page
)) /* Anon */
4179 mem_cgroup_charge_statistics(memcg
, page
, anon
, -nr_pages
);
4181 ClearPageCgroupUsed(pc
);
4183 * pc->mem_cgroup is not cleared here. It will be accessed when it's
4184 * freed from LRU. This is safe because uncharged page is expected not
4185 * to be reused (freed soon). Exception is SwapCache, it's handled by
4186 * special functions.
4189 unlock_page_cgroup(pc
);
4191 * even after unlock, we have memcg->res.usage here and this memcg
4192 * will never be freed, so it's safe to call css_get().
4194 memcg_check_events(memcg
, page
);
4195 if (do_swap_account
&& ctype
== MEM_CGROUP_CHARGE_TYPE_SWAPOUT
) {
4196 mem_cgroup_swap_statistics(memcg
, true);
4197 css_get(&memcg
->css
);
4200 * Migration does not charge the res_counter for the
4201 * replacement page, so leave it alone when phasing out the
4202 * page that is unused after the migration.
4204 if (!end_migration
&& !mem_cgroup_is_root(memcg
))
4205 mem_cgroup_do_uncharge(memcg
, nr_pages
, ctype
);
4210 unlock_page_cgroup(pc
);
4214 void mem_cgroup_uncharge_page(struct page
*page
)
4217 if (page_mapped(page
))
4219 VM_BUG_ON(page
->mapping
&& !PageAnon(page
));
4221 * If the page is in swap cache, uncharge should be deferred
4222 * to the swap path, which also properly accounts swap usage
4223 * and handles memcg lifetime.
4225 * Note that this check is not stable and reclaim may add the
4226 * page to swap cache at any time after this. However, if the
4227 * page is not in swap cache by the time page->mapcount hits
4228 * 0, there won't be any page table references to the swap
4229 * slot, and reclaim will free it and not actually write the
4232 if (PageSwapCache(page
))
4234 __mem_cgroup_uncharge_common(page
, MEM_CGROUP_CHARGE_TYPE_ANON
, false);
4237 void mem_cgroup_uncharge_cache_page(struct page
*page
)
4239 VM_BUG_ON(page_mapped(page
));
4240 VM_BUG_ON(page
->mapping
);
4241 __mem_cgroup_uncharge_common(page
, MEM_CGROUP_CHARGE_TYPE_CACHE
, false);
4245 * Batch_start/batch_end is called in unmap_page_range/invlidate/trucate.
4246 * In that cases, pages are freed continuously and we can expect pages
4247 * are in the same memcg. All these calls itself limits the number of
4248 * pages freed at once, then uncharge_start/end() is called properly.
4249 * This may be called prural(2) times in a context,
4252 void mem_cgroup_uncharge_start(void)
4254 current
->memcg_batch
.do_batch
++;
4255 /* We can do nest. */
4256 if (current
->memcg_batch
.do_batch
== 1) {
4257 current
->memcg_batch
.memcg
= NULL
;
4258 current
->memcg_batch
.nr_pages
= 0;
4259 current
->memcg_batch
.memsw_nr_pages
= 0;
4263 void mem_cgroup_uncharge_end(void)
4265 struct memcg_batch_info
*batch
= ¤t
->memcg_batch
;
4267 if (!batch
->do_batch
)
4271 if (batch
->do_batch
) /* If stacked, do nothing. */
4277 * This "batch->memcg" is valid without any css_get/put etc...
4278 * bacause we hide charges behind us.
4280 if (batch
->nr_pages
)
4281 res_counter_uncharge(&batch
->memcg
->res
,
4282 batch
->nr_pages
* PAGE_SIZE
);
4283 if (batch
->memsw_nr_pages
)
4284 res_counter_uncharge(&batch
->memcg
->memsw
,
4285 batch
->memsw_nr_pages
* PAGE_SIZE
);
4286 memcg_oom_recover(batch
->memcg
);
4287 /* forget this pointer (for sanity check) */
4288 batch
->memcg
= NULL
;
4293 * called after __delete_from_swap_cache() and drop "page" account.
4294 * memcg information is recorded to swap_cgroup of "ent"
4297 mem_cgroup_uncharge_swapcache(struct page
*page
, swp_entry_t ent
, bool swapout
)
4299 struct mem_cgroup
*memcg
;
4300 int ctype
= MEM_CGROUP_CHARGE_TYPE_SWAPOUT
;
4302 if (!swapout
) /* this was a swap cache but the swap is unused ! */
4303 ctype
= MEM_CGROUP_CHARGE_TYPE_DROP
;
4305 memcg
= __mem_cgroup_uncharge_common(page
, ctype
, false);
4308 * record memcg information, if swapout && memcg != NULL,
4309 * css_get() was called in uncharge().
4311 if (do_swap_account
&& swapout
&& memcg
)
4312 swap_cgroup_record(ent
, css_id(&memcg
->css
));
4316 #ifdef CONFIG_MEMCG_SWAP
4318 * called from swap_entry_free(). remove record in swap_cgroup and
4319 * uncharge "memsw" account.
4321 void mem_cgroup_uncharge_swap(swp_entry_t ent
)
4323 struct mem_cgroup
*memcg
;
4326 if (!do_swap_account
)
4329 id
= swap_cgroup_record(ent
, 0);
4331 memcg
= mem_cgroup_lookup(id
);
4334 * We uncharge this because swap is freed.
4335 * This memcg can be obsolete one. We avoid calling css_tryget
4337 if (!mem_cgroup_is_root(memcg
))
4338 res_counter_uncharge(&memcg
->memsw
, PAGE_SIZE
);
4339 mem_cgroup_swap_statistics(memcg
, false);
4340 css_put(&memcg
->css
);
4346 * mem_cgroup_move_swap_account - move swap charge and swap_cgroup's record.
4347 * @entry: swap entry to be moved
4348 * @from: mem_cgroup which the entry is moved from
4349 * @to: mem_cgroup which the entry is moved to
4351 * It succeeds only when the swap_cgroup's record for this entry is the same
4352 * as the mem_cgroup's id of @from.
4354 * Returns 0 on success, -EINVAL on failure.
4356 * The caller must have charged to @to, IOW, called res_counter_charge() about
4357 * both res and memsw, and called css_get().
4359 static int mem_cgroup_move_swap_account(swp_entry_t entry
,
4360 struct mem_cgroup
*from
, struct mem_cgroup
*to
)
4362 unsigned short old_id
, new_id
;
4364 old_id
= css_id(&from
->css
);
4365 new_id
= css_id(&to
->css
);
4367 if (swap_cgroup_cmpxchg(entry
, old_id
, new_id
) == old_id
) {
4368 mem_cgroup_swap_statistics(from
, false);
4369 mem_cgroup_swap_statistics(to
, true);
4371 * This function is only called from task migration context now.
4372 * It postpones res_counter and refcount handling till the end
4373 * of task migration(mem_cgroup_clear_mc()) for performance
4374 * improvement. But we cannot postpone css_get(to) because if
4375 * the process that has been moved to @to does swap-in, the
4376 * refcount of @to might be decreased to 0.
4378 * We are in attach() phase, so the cgroup is guaranteed to be
4379 * alive, so we can just call css_get().
4387 static inline int mem_cgroup_move_swap_account(swp_entry_t entry
,
4388 struct mem_cgroup
*from
, struct mem_cgroup
*to
)
4395 * Before starting migration, account PAGE_SIZE to mem_cgroup that the old
4398 void mem_cgroup_prepare_migration(struct page
*page
, struct page
*newpage
,
4399 struct mem_cgroup
**memcgp
)
4401 struct mem_cgroup
*memcg
= NULL
;
4402 unsigned int nr_pages
= 1;
4403 struct page_cgroup
*pc
;
4404 enum charge_type ctype
;
4408 if (mem_cgroup_disabled())
4411 if (PageTransHuge(page
))
4412 nr_pages
<<= compound_order(page
);
4414 pc
= lookup_page_cgroup(page
);
4415 lock_page_cgroup(pc
);
4416 if (PageCgroupUsed(pc
)) {
4417 memcg
= pc
->mem_cgroup
;
4418 css_get(&memcg
->css
);
4420 * At migrating an anonymous page, its mapcount goes down
4421 * to 0 and uncharge() will be called. But, even if it's fully
4422 * unmapped, migration may fail and this page has to be
4423 * charged again. We set MIGRATION flag here and delay uncharge
4424 * until end_migration() is called
4426 * Corner Case Thinking
4428 * When the old page was mapped as Anon and it's unmap-and-freed
4429 * while migration was ongoing.
4430 * If unmap finds the old page, uncharge() of it will be delayed
4431 * until end_migration(). If unmap finds a new page, it's
4432 * uncharged when it make mapcount to be 1->0. If unmap code
4433 * finds swap_migration_entry, the new page will not be mapped
4434 * and end_migration() will find it(mapcount==0).
4437 * When the old page was mapped but migraion fails, the kernel
4438 * remaps it. A charge for it is kept by MIGRATION flag even
4439 * if mapcount goes down to 0. We can do remap successfully
4440 * without charging it again.
4443 * The "old" page is under lock_page() until the end of
4444 * migration, so, the old page itself will not be swapped-out.
4445 * If the new page is swapped out before end_migraton, our
4446 * hook to usual swap-out path will catch the event.
4449 SetPageCgroupMigration(pc
);
4451 unlock_page_cgroup(pc
);
4453 * If the page is not charged at this point,
4461 * We charge new page before it's used/mapped. So, even if unlock_page()
4462 * is called before end_migration, we can catch all events on this new
4463 * page. In the case new page is migrated but not remapped, new page's
4464 * mapcount will be finally 0 and we call uncharge in end_migration().
4467 ctype
= MEM_CGROUP_CHARGE_TYPE_ANON
;
4469 ctype
= MEM_CGROUP_CHARGE_TYPE_CACHE
;
4471 * The page is committed to the memcg, but it's not actually
4472 * charged to the res_counter since we plan on replacing the
4473 * old one and only one page is going to be left afterwards.
4475 __mem_cgroup_commit_charge(memcg
, newpage
, nr_pages
, ctype
, false);
4478 /* remove redundant charge if migration failed*/
4479 void mem_cgroup_end_migration(struct mem_cgroup
*memcg
,
4480 struct page
*oldpage
, struct page
*newpage
, bool migration_ok
)
4482 struct page
*used
, *unused
;
4483 struct page_cgroup
*pc
;
4489 if (!migration_ok
) {
4496 anon
= PageAnon(used
);
4497 __mem_cgroup_uncharge_common(unused
,
4498 anon
? MEM_CGROUP_CHARGE_TYPE_ANON
4499 : MEM_CGROUP_CHARGE_TYPE_CACHE
,
4501 css_put(&memcg
->css
);
4503 * We disallowed uncharge of pages under migration because mapcount
4504 * of the page goes down to zero, temporarly.
4505 * Clear the flag and check the page should be charged.
4507 pc
= lookup_page_cgroup(oldpage
);
4508 lock_page_cgroup(pc
);
4509 ClearPageCgroupMigration(pc
);
4510 unlock_page_cgroup(pc
);
4513 * If a page is a file cache, radix-tree replacement is very atomic
4514 * and we can skip this check. When it was an Anon page, its mapcount
4515 * goes down to 0. But because we added MIGRATION flage, it's not
4516 * uncharged yet. There are several case but page->mapcount check
4517 * and USED bit check in mem_cgroup_uncharge_page() will do enough
4518 * check. (see prepare_charge() also)
4521 mem_cgroup_uncharge_page(used
);
4525 * At replace page cache, newpage is not under any memcg but it's on
4526 * LRU. So, this function doesn't touch res_counter but handles LRU
4527 * in correct way. Both pages are locked so we cannot race with uncharge.
4529 void mem_cgroup_replace_page_cache(struct page
*oldpage
,
4530 struct page
*newpage
)
4532 struct mem_cgroup
*memcg
= NULL
;
4533 struct page_cgroup
*pc
;
4534 enum charge_type type
= MEM_CGROUP_CHARGE_TYPE_CACHE
;
4536 if (mem_cgroup_disabled())
4539 pc
= lookup_page_cgroup(oldpage
);
4540 /* fix accounting on old pages */
4541 lock_page_cgroup(pc
);
4542 if (PageCgroupUsed(pc
)) {
4543 memcg
= pc
->mem_cgroup
;
4544 mem_cgroup_charge_statistics(memcg
, oldpage
, false, -1);
4545 ClearPageCgroupUsed(pc
);
4547 unlock_page_cgroup(pc
);
4550 * When called from shmem_replace_page(), in some cases the
4551 * oldpage has already been charged, and in some cases not.
4556 * Even if newpage->mapping was NULL before starting replacement,
4557 * the newpage may be on LRU(or pagevec for LRU) already. We lock
4558 * LRU while we overwrite pc->mem_cgroup.
4560 __mem_cgroup_commit_charge(memcg
, newpage
, 1, type
, true);
4563 #ifdef CONFIG_DEBUG_VM
4564 static struct page_cgroup
*lookup_page_cgroup_used(struct page
*page
)
4566 struct page_cgroup
*pc
;
4568 pc
= lookup_page_cgroup(page
);
4570 * Can be NULL while feeding pages into the page allocator for
4571 * the first time, i.e. during boot or memory hotplug;
4572 * or when mem_cgroup_disabled().
4574 if (likely(pc
) && PageCgroupUsed(pc
))
4579 bool mem_cgroup_bad_page_check(struct page
*page
)
4581 if (mem_cgroup_disabled())
4584 return lookup_page_cgroup_used(page
) != NULL
;
4587 void mem_cgroup_print_bad_page(struct page
*page
)
4589 struct page_cgroup
*pc
;
4591 pc
= lookup_page_cgroup_used(page
);
4593 pr_alert("pc:%p pc->flags:%lx pc->mem_cgroup:%p\n",
4594 pc
, pc
->flags
, pc
->mem_cgroup
);
4599 static int mem_cgroup_resize_limit(struct mem_cgroup
*memcg
,
4600 unsigned long long val
)
4603 u64 memswlimit
, memlimit
;
4605 int children
= mem_cgroup_count_children(memcg
);
4606 u64 curusage
, oldusage
;
4610 * For keeping hierarchical_reclaim simple, how long we should retry
4611 * is depends on callers. We set our retry-count to be function
4612 * of # of children which we should visit in this loop.
4614 retry_count
= MEM_CGROUP_RECLAIM_RETRIES
* children
;
4616 oldusage
= res_counter_read_u64(&memcg
->res
, RES_USAGE
);
4619 while (retry_count
) {
4620 if (signal_pending(current
)) {
4625 * Rather than hide all in some function, I do this in
4626 * open coded manner. You see what this really does.
4627 * We have to guarantee memcg->res.limit <= memcg->memsw.limit.
4629 mutex_lock(&set_limit_mutex
);
4630 memswlimit
= res_counter_read_u64(&memcg
->memsw
, RES_LIMIT
);
4631 if (memswlimit
< val
) {
4633 mutex_unlock(&set_limit_mutex
);
4637 memlimit
= res_counter_read_u64(&memcg
->res
, RES_LIMIT
);
4641 ret
= res_counter_set_limit(&memcg
->res
, val
);
4643 if (memswlimit
== val
)
4644 memcg
->memsw_is_minimum
= true;
4646 memcg
->memsw_is_minimum
= false;
4648 mutex_unlock(&set_limit_mutex
);
4653 mem_cgroup_reclaim(memcg
, GFP_KERNEL
,
4654 MEM_CGROUP_RECLAIM_SHRINK
);
4655 curusage
= res_counter_read_u64(&memcg
->res
, RES_USAGE
);
4656 /* Usage is reduced ? */
4657 if (curusage
>= oldusage
)
4660 oldusage
= curusage
;
4662 if (!ret
&& enlarge
)
4663 memcg_oom_recover(memcg
);
4668 static int mem_cgroup_resize_memsw_limit(struct mem_cgroup
*memcg
,
4669 unsigned long long val
)
4672 u64 memlimit
, memswlimit
, oldusage
, curusage
;
4673 int children
= mem_cgroup_count_children(memcg
);
4677 /* see mem_cgroup_resize_res_limit */
4678 retry_count
= children
* MEM_CGROUP_RECLAIM_RETRIES
;
4679 oldusage
= res_counter_read_u64(&memcg
->memsw
, RES_USAGE
);
4680 while (retry_count
) {
4681 if (signal_pending(current
)) {
4686 * Rather than hide all in some function, I do this in
4687 * open coded manner. You see what this really does.
4688 * We have to guarantee memcg->res.limit <= memcg->memsw.limit.
4690 mutex_lock(&set_limit_mutex
);
4691 memlimit
= res_counter_read_u64(&memcg
->res
, RES_LIMIT
);
4692 if (memlimit
> val
) {
4694 mutex_unlock(&set_limit_mutex
);
4697 memswlimit
= res_counter_read_u64(&memcg
->memsw
, RES_LIMIT
);
4698 if (memswlimit
< val
)
4700 ret
= res_counter_set_limit(&memcg
->memsw
, val
);
4702 if (memlimit
== val
)
4703 memcg
->memsw_is_minimum
= true;
4705 memcg
->memsw_is_minimum
= false;
4707 mutex_unlock(&set_limit_mutex
);
4712 mem_cgroup_reclaim(memcg
, GFP_KERNEL
,
4713 MEM_CGROUP_RECLAIM_NOSWAP
|
4714 MEM_CGROUP_RECLAIM_SHRINK
);
4715 curusage
= res_counter_read_u64(&memcg
->memsw
, RES_USAGE
);
4716 /* Usage is reduced ? */
4717 if (curusage
>= oldusage
)
4720 oldusage
= curusage
;
4722 if (!ret
&& enlarge
)
4723 memcg_oom_recover(memcg
);
4727 unsigned long mem_cgroup_soft_limit_reclaim(struct zone
*zone
, int order
,
4729 unsigned long *total_scanned
)
4731 unsigned long nr_reclaimed
= 0;
4732 struct mem_cgroup_per_zone
*mz
, *next_mz
= NULL
;
4733 unsigned long reclaimed
;
4735 struct mem_cgroup_tree_per_zone
*mctz
;
4736 unsigned long long excess
;
4737 unsigned long nr_scanned
;
4742 mctz
= soft_limit_tree_node_zone(zone_to_nid(zone
), zone_idx(zone
));
4744 * This loop can run a while, specially if mem_cgroup's continuously
4745 * keep exceeding their soft limit and putting the system under
4752 mz
= mem_cgroup_largest_soft_limit_node(mctz
);
4757 reclaimed
= mem_cgroup_soft_reclaim(mz
->memcg
, zone
,
4758 gfp_mask
, &nr_scanned
);
4759 nr_reclaimed
+= reclaimed
;
4760 *total_scanned
+= nr_scanned
;
4761 spin_lock(&mctz
->lock
);
4764 * If we failed to reclaim anything from this memory cgroup
4765 * it is time to move on to the next cgroup
4771 * Loop until we find yet another one.
4773 * By the time we get the soft_limit lock
4774 * again, someone might have aded the
4775 * group back on the RB tree. Iterate to
4776 * make sure we get a different mem.
4777 * mem_cgroup_largest_soft_limit_node returns
4778 * NULL if no other cgroup is present on
4782 __mem_cgroup_largest_soft_limit_node(mctz
);
4784 css_put(&next_mz
->memcg
->css
);
4785 else /* next_mz == NULL or other memcg */
4789 __mem_cgroup_remove_exceeded(mz
->memcg
, mz
, mctz
);
4790 excess
= res_counter_soft_limit_excess(&mz
->memcg
->res
);
4792 * One school of thought says that we should not add
4793 * back the node to the tree if reclaim returns 0.
4794 * But our reclaim could return 0, simply because due
4795 * to priority we are exposing a smaller subset of
4796 * memory to reclaim from. Consider this as a longer
4799 /* If excess == 0, no tree ops */
4800 __mem_cgroup_insert_exceeded(mz
->memcg
, mz
, mctz
, excess
);
4801 spin_unlock(&mctz
->lock
);
4802 css_put(&mz
->memcg
->css
);
4805 * Could not reclaim anything and there are no more
4806 * mem cgroups to try or we seem to be looping without
4807 * reclaiming anything.
4809 if (!nr_reclaimed
&&
4811 loop
> MEM_CGROUP_MAX_SOFT_LIMIT_RECLAIM_LOOPS
))
4813 } while (!nr_reclaimed
);
4815 css_put(&next_mz
->memcg
->css
);
4816 return nr_reclaimed
;
4820 * mem_cgroup_force_empty_list - clears LRU of a group
4821 * @memcg: group to clear
4824 * @lru: lru to to clear
4826 * Traverse a specified page_cgroup list and try to drop them all. This doesn't
4827 * reclaim the pages page themselves - pages are moved to the parent (or root)
4830 static void mem_cgroup_force_empty_list(struct mem_cgroup
*memcg
,
4831 int node
, int zid
, enum lru_list lru
)
4833 struct lruvec
*lruvec
;
4834 unsigned long flags
;
4835 struct list_head
*list
;
4839 zone
= &NODE_DATA(node
)->node_zones
[zid
];
4840 lruvec
= mem_cgroup_zone_lruvec(zone
, memcg
);
4841 list
= &lruvec
->lists
[lru
];
4845 struct page_cgroup
*pc
;
4848 spin_lock_irqsave(&zone
->lru_lock
, flags
);
4849 if (list_empty(list
)) {
4850 spin_unlock_irqrestore(&zone
->lru_lock
, flags
);
4853 page
= list_entry(list
->prev
, struct page
, lru
);
4855 list_move(&page
->lru
, list
);
4857 spin_unlock_irqrestore(&zone
->lru_lock
, flags
);
4860 spin_unlock_irqrestore(&zone
->lru_lock
, flags
);
4862 pc
= lookup_page_cgroup(page
);
4864 if (mem_cgroup_move_parent(page
, pc
, memcg
)) {
4865 /* found lock contention or "pc" is obsolete. */
4870 } while (!list_empty(list
));
4874 * make mem_cgroup's charge to be 0 if there is no task by moving
4875 * all the charges and pages to the parent.
4876 * This enables deleting this mem_cgroup.
4878 * Caller is responsible for holding css reference on the memcg.
4880 static void mem_cgroup_reparent_charges(struct mem_cgroup
*memcg
)
4886 /* This is for making all *used* pages to be on LRU. */
4887 lru_add_drain_all();
4888 drain_all_stock_sync(memcg
);
4889 mem_cgroup_start_move(memcg
);
4890 for_each_node_state(node
, N_MEMORY
) {
4891 for (zid
= 0; zid
< MAX_NR_ZONES
; zid
++) {
4894 mem_cgroup_force_empty_list(memcg
,
4899 mem_cgroup_end_move(memcg
);
4900 memcg_oom_recover(memcg
);
4904 * Kernel memory may not necessarily be trackable to a specific
4905 * process. So they are not migrated, and therefore we can't
4906 * expect their value to drop to 0 here.
4907 * Having res filled up with kmem only is enough.
4909 * This is a safety check because mem_cgroup_force_empty_list
4910 * could have raced with mem_cgroup_replace_page_cache callers
4911 * so the lru seemed empty but the page could have been added
4912 * right after the check. RES_USAGE should be safe as we always
4913 * charge before adding to the LRU.
4915 usage
= res_counter_read_u64(&memcg
->res
, RES_USAGE
) -
4916 res_counter_read_u64(&memcg
->kmem
, RES_USAGE
);
4917 } while (usage
> 0);
4921 * This mainly exists for tests during the setting of set of use_hierarchy.
4922 * Since this is the very setting we are changing, the current hierarchy value
4925 static inline bool __memcg_has_children(struct mem_cgroup
*memcg
)
4927 struct cgroup_subsys_state
*pos
;
4929 /* bounce at first found */
4930 css_for_each_child(pos
, &memcg
->css
)
4936 * Must be called with memcg_create_mutex held, unless the cgroup is guaranteed
4937 * to be already dead (as in mem_cgroup_force_empty, for instance). This is
4938 * from mem_cgroup_count_children(), in the sense that we don't really care how
4939 * many children we have; we only need to know if we have any. It also counts
4940 * any memcg without hierarchy as infertile.
4942 static inline bool memcg_has_children(struct mem_cgroup
*memcg
)
4944 return memcg
->use_hierarchy
&& __memcg_has_children(memcg
);
4948 * Reclaims as many pages from the given memcg as possible and moves
4949 * the rest to the parent.
4951 * Caller is responsible for holding css reference for memcg.
4953 static int mem_cgroup_force_empty(struct mem_cgroup
*memcg
)
4955 int nr_retries
= MEM_CGROUP_RECLAIM_RETRIES
;
4956 struct cgroup
*cgrp
= memcg
->css
.cgroup
;
4958 /* returns EBUSY if there is a task or if we come here twice. */
4959 if (cgroup_task_count(cgrp
) || !list_empty(&cgrp
->children
))
4962 /* we call try-to-free pages for make this cgroup empty */
4963 lru_add_drain_all();
4964 /* try to free all pages in this cgroup */
4965 while (nr_retries
&& res_counter_read_u64(&memcg
->res
, RES_USAGE
) > 0) {
4968 if (signal_pending(current
))
4971 progress
= try_to_free_mem_cgroup_pages(memcg
, GFP_KERNEL
,
4975 /* maybe some writeback is necessary */
4976 congestion_wait(BLK_RW_ASYNC
, HZ
/10);
4981 mem_cgroup_reparent_charges(memcg
);
4986 static int mem_cgroup_force_empty_write(struct cgroup_subsys_state
*css
,
4989 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
4992 if (mem_cgroup_is_root(memcg
))
4994 css_get(&memcg
->css
);
4995 ret
= mem_cgroup_force_empty(memcg
);
4996 css_put(&memcg
->css
);
5002 static u64
mem_cgroup_hierarchy_read(struct cgroup_subsys_state
*css
,
5005 return mem_cgroup_from_css(css
)->use_hierarchy
;
5008 static int mem_cgroup_hierarchy_write(struct cgroup_subsys_state
*css
,
5009 struct cftype
*cft
, u64 val
)
5012 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
5013 struct mem_cgroup
*parent_memcg
= mem_cgroup_from_css(css_parent(&memcg
->css
));
5015 mutex_lock(&memcg_create_mutex
);
5017 if (memcg
->use_hierarchy
== val
)
5021 * If parent's use_hierarchy is set, we can't make any modifications
5022 * in the child subtrees. If it is unset, then the change can
5023 * occur, provided the current cgroup has no children.
5025 * For the root cgroup, parent_mem is NULL, we allow value to be
5026 * set if there are no children.
5028 if ((!parent_memcg
|| !parent_memcg
->use_hierarchy
) &&
5029 (val
== 1 || val
== 0)) {
5030 if (!__memcg_has_children(memcg
))
5031 memcg
->use_hierarchy
= val
;
5038 mutex_unlock(&memcg_create_mutex
);
5044 static unsigned long mem_cgroup_recursive_stat(struct mem_cgroup
*memcg
,
5045 enum mem_cgroup_stat_index idx
)
5047 struct mem_cgroup
*iter
;
5050 /* Per-cpu values can be negative, use a signed accumulator */
5051 for_each_mem_cgroup_tree(iter
, memcg
)
5052 val
+= mem_cgroup_read_stat(iter
, idx
);
5054 if (val
< 0) /* race ? */
5059 static inline u64
mem_cgroup_usage(struct mem_cgroup
*memcg
, bool swap
)
5063 if (!mem_cgroup_is_root(memcg
)) {
5065 return res_counter_read_u64(&memcg
->res
, RES_USAGE
);
5067 return res_counter_read_u64(&memcg
->memsw
, RES_USAGE
);
5071 * Transparent hugepages are still accounted for in MEM_CGROUP_STAT_RSS
5072 * as well as in MEM_CGROUP_STAT_RSS_HUGE.
5074 val
= mem_cgroup_recursive_stat(memcg
, MEM_CGROUP_STAT_CACHE
);
5075 val
+= mem_cgroup_recursive_stat(memcg
, MEM_CGROUP_STAT_RSS
);
5078 val
+= mem_cgroup_recursive_stat(memcg
, MEM_CGROUP_STAT_SWAP
);
5080 return val
<< PAGE_SHIFT
;
5083 static ssize_t
mem_cgroup_read(struct cgroup_subsys_state
*css
,
5084 struct cftype
*cft
, struct file
*file
,
5085 char __user
*buf
, size_t nbytes
, loff_t
*ppos
)
5087 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
5093 type
= MEMFILE_TYPE(cft
->private);
5094 name
= MEMFILE_ATTR(cft
->private);
5098 if (name
== RES_USAGE
)
5099 val
= mem_cgroup_usage(memcg
, false);
5101 val
= res_counter_read_u64(&memcg
->res
, name
);
5104 if (name
== RES_USAGE
)
5105 val
= mem_cgroup_usage(memcg
, true);
5107 val
= res_counter_read_u64(&memcg
->memsw
, name
);
5110 val
= res_counter_read_u64(&memcg
->kmem
, name
);
5116 len
= scnprintf(str
, sizeof(str
), "%llu\n", (unsigned long long)val
);
5117 return simple_read_from_buffer(buf
, nbytes
, ppos
, str
, len
);
5120 static int memcg_update_kmem_limit(struct cgroup_subsys_state
*css
, u64 val
)
5123 #ifdef CONFIG_MEMCG_KMEM
5124 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
5126 * For simplicity, we won't allow this to be disabled. It also can't
5127 * be changed if the cgroup has children already, or if tasks had
5130 * If tasks join before we set the limit, a person looking at
5131 * kmem.usage_in_bytes will have no way to determine when it took
5132 * place, which makes the value quite meaningless.
5134 * After it first became limited, changes in the value of the limit are
5135 * of course permitted.
5137 mutex_lock(&memcg_create_mutex
);
5138 mutex_lock(&set_limit_mutex
);
5139 if (!memcg
->kmem_account_flags
&& val
!= RESOURCE_MAX
) {
5140 if (cgroup_task_count(css
->cgroup
) || memcg_has_children(memcg
)) {
5144 ret
= res_counter_set_limit(&memcg
->kmem
, val
);
5147 ret
= memcg_update_cache_sizes(memcg
);
5149 res_counter_set_limit(&memcg
->kmem
, RESOURCE_MAX
);
5152 static_key_slow_inc(&memcg_kmem_enabled_key
);
5154 * setting the active bit after the inc will guarantee no one
5155 * starts accounting before all call sites are patched
5157 memcg_kmem_set_active(memcg
);
5159 ret
= res_counter_set_limit(&memcg
->kmem
, val
);
5161 mutex_unlock(&set_limit_mutex
);
5162 mutex_unlock(&memcg_create_mutex
);
5167 #ifdef CONFIG_MEMCG_KMEM
5168 static int memcg_propagate_kmem(struct mem_cgroup
*memcg
)
5171 struct mem_cgroup
*parent
= parent_mem_cgroup(memcg
);
5175 memcg
->kmem_account_flags
= parent
->kmem_account_flags
;
5177 * When that happen, we need to disable the static branch only on those
5178 * memcgs that enabled it. To achieve this, we would be forced to
5179 * complicate the code by keeping track of which memcgs were the ones
5180 * that actually enabled limits, and which ones got it from its
5183 * It is a lot simpler just to do static_key_slow_inc() on every child
5184 * that is accounted.
5186 if (!memcg_kmem_is_active(memcg
))
5190 * __mem_cgroup_free() will issue static_key_slow_dec() because this
5191 * memcg is active already. If the later initialization fails then the
5192 * cgroup core triggers the cleanup so we do not have to do it here.
5194 static_key_slow_inc(&memcg_kmem_enabled_key
);
5196 mutex_lock(&set_limit_mutex
);
5197 memcg_stop_kmem_account();
5198 ret
= memcg_update_cache_sizes(memcg
);
5199 memcg_resume_kmem_account();
5200 mutex_unlock(&set_limit_mutex
);
5204 #endif /* CONFIG_MEMCG_KMEM */
5207 * The user of this function is...
5210 static int mem_cgroup_write(struct cgroup_subsys_state
*css
, struct cftype
*cft
,
5213 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
5216 unsigned long long val
;
5219 type
= MEMFILE_TYPE(cft
->private);
5220 name
= MEMFILE_ATTR(cft
->private);
5224 if (mem_cgroup_is_root(memcg
)) { /* Can't set limit on root */
5228 /* This function does all necessary parse...reuse it */
5229 ret
= res_counter_memparse_write_strategy(buffer
, &val
);
5233 ret
= mem_cgroup_resize_limit(memcg
, val
);
5234 else if (type
== _MEMSWAP
)
5235 ret
= mem_cgroup_resize_memsw_limit(memcg
, val
);
5236 else if (type
== _KMEM
)
5237 ret
= memcg_update_kmem_limit(css
, val
);
5241 case RES_SOFT_LIMIT
:
5242 ret
= res_counter_memparse_write_strategy(buffer
, &val
);
5246 * For memsw, soft limits are hard to implement in terms
5247 * of semantics, for now, we support soft limits for
5248 * control without swap
5251 ret
= res_counter_set_soft_limit(&memcg
->res
, val
);
5256 ret
= -EINVAL
; /* should be BUG() ? */
5262 static void memcg_get_hierarchical_limit(struct mem_cgroup
*memcg
,
5263 unsigned long long *mem_limit
, unsigned long long *memsw_limit
)
5265 unsigned long long min_limit
, min_memsw_limit
, tmp
;
5267 min_limit
= res_counter_read_u64(&memcg
->res
, RES_LIMIT
);
5268 min_memsw_limit
= res_counter_read_u64(&memcg
->memsw
, RES_LIMIT
);
5269 if (!memcg
->use_hierarchy
)
5272 while (css_parent(&memcg
->css
)) {
5273 memcg
= mem_cgroup_from_css(css_parent(&memcg
->css
));
5274 if (!memcg
->use_hierarchy
)
5276 tmp
= res_counter_read_u64(&memcg
->res
, RES_LIMIT
);
5277 min_limit
= min(min_limit
, tmp
);
5278 tmp
= res_counter_read_u64(&memcg
->memsw
, RES_LIMIT
);
5279 min_memsw_limit
= min(min_memsw_limit
, tmp
);
5282 *mem_limit
= min_limit
;
5283 *memsw_limit
= min_memsw_limit
;
5286 static int mem_cgroup_reset(struct cgroup_subsys_state
*css
, unsigned int event
)
5288 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
5292 type
= MEMFILE_TYPE(event
);
5293 name
= MEMFILE_ATTR(event
);
5298 res_counter_reset_max(&memcg
->res
);
5299 else if (type
== _MEMSWAP
)
5300 res_counter_reset_max(&memcg
->memsw
);
5301 else if (type
== _KMEM
)
5302 res_counter_reset_max(&memcg
->kmem
);
5308 res_counter_reset_failcnt(&memcg
->res
);
5309 else if (type
== _MEMSWAP
)
5310 res_counter_reset_failcnt(&memcg
->memsw
);
5311 else if (type
== _KMEM
)
5312 res_counter_reset_failcnt(&memcg
->kmem
);
5321 static u64
mem_cgroup_move_charge_read(struct cgroup_subsys_state
*css
,
5324 return mem_cgroup_from_css(css
)->move_charge_at_immigrate
;
5328 static int mem_cgroup_move_charge_write(struct cgroup_subsys_state
*css
,
5329 struct cftype
*cft
, u64 val
)
5331 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
5333 if (val
>= (1 << NR_MOVE_TYPE
))
5337 * No kind of locking is needed in here, because ->can_attach() will
5338 * check this value once in the beginning of the process, and then carry
5339 * on with stale data. This means that changes to this value will only
5340 * affect task migrations starting after the change.
5342 memcg
->move_charge_at_immigrate
= val
;
5346 static int mem_cgroup_move_charge_write(struct cgroup_subsys_state
*css
,
5347 struct cftype
*cft
, u64 val
)
5354 static int memcg_numa_stat_show(struct cgroup_subsys_state
*css
,
5355 struct cftype
*cft
, struct seq_file
*m
)
5358 unsigned long total_nr
, file_nr
, anon_nr
, unevictable_nr
;
5359 unsigned long node_nr
;
5360 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
5362 total_nr
= mem_cgroup_nr_lru_pages(memcg
, LRU_ALL
);
5363 seq_printf(m
, "total=%lu", total_nr
);
5364 for_each_node_state(nid
, N_MEMORY
) {
5365 node_nr
= mem_cgroup_node_nr_lru_pages(memcg
, nid
, LRU_ALL
);
5366 seq_printf(m
, " N%d=%lu", nid
, node_nr
);
5370 file_nr
= mem_cgroup_nr_lru_pages(memcg
, LRU_ALL_FILE
);
5371 seq_printf(m
, "file=%lu", file_nr
);
5372 for_each_node_state(nid
, N_MEMORY
) {
5373 node_nr
= mem_cgroup_node_nr_lru_pages(memcg
, nid
,
5375 seq_printf(m
, " N%d=%lu", nid
, node_nr
);
5379 anon_nr
= mem_cgroup_nr_lru_pages(memcg
, LRU_ALL_ANON
);
5380 seq_printf(m
, "anon=%lu", anon_nr
);
5381 for_each_node_state(nid
, N_MEMORY
) {
5382 node_nr
= mem_cgroup_node_nr_lru_pages(memcg
, nid
,
5384 seq_printf(m
, " N%d=%lu", nid
, node_nr
);
5388 unevictable_nr
= mem_cgroup_nr_lru_pages(memcg
, BIT(LRU_UNEVICTABLE
));
5389 seq_printf(m
, "unevictable=%lu", unevictable_nr
);
5390 for_each_node_state(nid
, N_MEMORY
) {
5391 node_nr
= mem_cgroup_node_nr_lru_pages(memcg
, nid
,
5392 BIT(LRU_UNEVICTABLE
));
5393 seq_printf(m
, " N%d=%lu", nid
, node_nr
);
5398 #endif /* CONFIG_NUMA */
5400 static inline void mem_cgroup_lru_names_not_uptodate(void)
5402 BUILD_BUG_ON(ARRAY_SIZE(mem_cgroup_lru_names
) != NR_LRU_LISTS
);
5405 static int memcg_stat_show(struct cgroup_subsys_state
*css
, struct cftype
*cft
,
5408 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
5409 struct mem_cgroup
*mi
;
5412 for (i
= 0; i
< MEM_CGROUP_STAT_NSTATS
; i
++) {
5413 if (i
== MEM_CGROUP_STAT_SWAP
&& !do_swap_account
)
5415 seq_printf(m
, "%s %ld\n", mem_cgroup_stat_names
[i
],
5416 mem_cgroup_read_stat(memcg
, i
) * PAGE_SIZE
);
5419 for (i
= 0; i
< MEM_CGROUP_EVENTS_NSTATS
; i
++)
5420 seq_printf(m
, "%s %lu\n", mem_cgroup_events_names
[i
],
5421 mem_cgroup_read_events(memcg
, i
));
5423 for (i
= 0; i
< NR_LRU_LISTS
; i
++)
5424 seq_printf(m
, "%s %lu\n", mem_cgroup_lru_names
[i
],
5425 mem_cgroup_nr_lru_pages(memcg
, BIT(i
)) * PAGE_SIZE
);
5427 /* Hierarchical information */
5429 unsigned long long limit
, memsw_limit
;
5430 memcg_get_hierarchical_limit(memcg
, &limit
, &memsw_limit
);
5431 seq_printf(m
, "hierarchical_memory_limit %llu\n", limit
);
5432 if (do_swap_account
)
5433 seq_printf(m
, "hierarchical_memsw_limit %llu\n",
5437 for (i
= 0; i
< MEM_CGROUP_STAT_NSTATS
; i
++) {
5440 if (i
== MEM_CGROUP_STAT_SWAP
&& !do_swap_account
)
5442 for_each_mem_cgroup_tree(mi
, memcg
)
5443 val
+= mem_cgroup_read_stat(mi
, i
) * PAGE_SIZE
;
5444 seq_printf(m
, "total_%s %lld\n", mem_cgroup_stat_names
[i
], val
);
5447 for (i
= 0; i
< MEM_CGROUP_EVENTS_NSTATS
; i
++) {
5448 unsigned long long val
= 0;
5450 for_each_mem_cgroup_tree(mi
, memcg
)
5451 val
+= mem_cgroup_read_events(mi
, i
);
5452 seq_printf(m
, "total_%s %llu\n",
5453 mem_cgroup_events_names
[i
], val
);
5456 for (i
= 0; i
< NR_LRU_LISTS
; i
++) {
5457 unsigned long long val
= 0;
5459 for_each_mem_cgroup_tree(mi
, memcg
)
5460 val
+= mem_cgroup_nr_lru_pages(mi
, BIT(i
)) * PAGE_SIZE
;
5461 seq_printf(m
, "total_%s %llu\n", mem_cgroup_lru_names
[i
], val
);
5464 #ifdef CONFIG_DEBUG_VM
5467 struct mem_cgroup_per_zone
*mz
;
5468 struct zone_reclaim_stat
*rstat
;
5469 unsigned long recent_rotated
[2] = {0, 0};
5470 unsigned long recent_scanned
[2] = {0, 0};
5472 for_each_online_node(nid
)
5473 for (zid
= 0; zid
< MAX_NR_ZONES
; zid
++) {
5474 mz
= mem_cgroup_zoneinfo(memcg
, nid
, zid
);
5475 rstat
= &mz
->lruvec
.reclaim_stat
;
5477 recent_rotated
[0] += rstat
->recent_rotated
[0];
5478 recent_rotated
[1] += rstat
->recent_rotated
[1];
5479 recent_scanned
[0] += rstat
->recent_scanned
[0];
5480 recent_scanned
[1] += rstat
->recent_scanned
[1];
5482 seq_printf(m
, "recent_rotated_anon %lu\n", recent_rotated
[0]);
5483 seq_printf(m
, "recent_rotated_file %lu\n", recent_rotated
[1]);
5484 seq_printf(m
, "recent_scanned_anon %lu\n", recent_scanned
[0]);
5485 seq_printf(m
, "recent_scanned_file %lu\n", recent_scanned
[1]);
5492 static u64
mem_cgroup_swappiness_read(struct cgroup_subsys_state
*css
,
5495 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
5497 return mem_cgroup_swappiness(memcg
);
5500 static int mem_cgroup_swappiness_write(struct cgroup_subsys_state
*css
,
5501 struct cftype
*cft
, u64 val
)
5503 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
5504 struct mem_cgroup
*parent
= mem_cgroup_from_css(css_parent(&memcg
->css
));
5506 if (val
> 100 || !parent
)
5509 mutex_lock(&memcg_create_mutex
);
5511 /* If under hierarchy, only empty-root can set this value */
5512 if ((parent
->use_hierarchy
) || memcg_has_children(memcg
)) {
5513 mutex_unlock(&memcg_create_mutex
);
5517 memcg
->swappiness
= val
;
5519 mutex_unlock(&memcg_create_mutex
);
5524 static void __mem_cgroup_threshold(struct mem_cgroup
*memcg
, bool swap
)
5526 struct mem_cgroup_threshold_ary
*t
;
5532 t
= rcu_dereference(memcg
->thresholds
.primary
);
5534 t
= rcu_dereference(memcg
->memsw_thresholds
.primary
);
5539 usage
= mem_cgroup_usage(memcg
, swap
);
5542 * current_threshold points to threshold just below or equal to usage.
5543 * If it's not true, a threshold was crossed after last
5544 * call of __mem_cgroup_threshold().
5546 i
= t
->current_threshold
;
5549 * Iterate backward over array of thresholds starting from
5550 * current_threshold and check if a threshold is crossed.
5551 * If none of thresholds below usage is crossed, we read
5552 * only one element of the array here.
5554 for (; i
>= 0 && unlikely(t
->entries
[i
].threshold
> usage
); i
--)
5555 eventfd_signal(t
->entries
[i
].eventfd
, 1);
5557 /* i = current_threshold + 1 */
5561 * Iterate forward over array of thresholds starting from
5562 * current_threshold+1 and check if a threshold is crossed.
5563 * If none of thresholds above usage is crossed, we read
5564 * only one element of the array here.
5566 for (; i
< t
->size
&& unlikely(t
->entries
[i
].threshold
<= usage
); i
++)
5567 eventfd_signal(t
->entries
[i
].eventfd
, 1);
5569 /* Update current_threshold */
5570 t
->current_threshold
= i
- 1;
5575 static void mem_cgroup_threshold(struct mem_cgroup
*memcg
)
5578 __mem_cgroup_threshold(memcg
, false);
5579 if (do_swap_account
)
5580 __mem_cgroup_threshold(memcg
, true);
5582 memcg
= parent_mem_cgroup(memcg
);
5586 static int compare_thresholds(const void *a
, const void *b
)
5588 const struct mem_cgroup_threshold
*_a
= a
;
5589 const struct mem_cgroup_threshold
*_b
= b
;
5591 return _a
->threshold
- _b
->threshold
;
5594 static int mem_cgroup_oom_notify_cb(struct mem_cgroup
*memcg
)
5596 struct mem_cgroup_eventfd_list
*ev
;
5598 list_for_each_entry(ev
, &memcg
->oom_notify
, list
)
5599 eventfd_signal(ev
->eventfd
, 1);
5603 static void mem_cgroup_oom_notify(struct mem_cgroup
*memcg
)
5605 struct mem_cgroup
*iter
;
5607 for_each_mem_cgroup_tree(iter
, memcg
)
5608 mem_cgroup_oom_notify_cb(iter
);
5611 static int mem_cgroup_usage_register_event(struct cgroup_subsys_state
*css
,
5612 struct cftype
*cft
, struct eventfd_ctx
*eventfd
, const char *args
)
5614 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
5615 struct mem_cgroup_thresholds
*thresholds
;
5616 struct mem_cgroup_threshold_ary
*new;
5617 enum res_type type
= MEMFILE_TYPE(cft
->private);
5618 u64 threshold
, usage
;
5621 ret
= res_counter_memparse_write_strategy(args
, &threshold
);
5625 mutex_lock(&memcg
->thresholds_lock
);
5628 thresholds
= &memcg
->thresholds
;
5629 else if (type
== _MEMSWAP
)
5630 thresholds
= &memcg
->memsw_thresholds
;
5634 usage
= mem_cgroup_usage(memcg
, type
== _MEMSWAP
);
5636 /* Check if a threshold crossed before adding a new one */
5637 if (thresholds
->primary
)
5638 __mem_cgroup_threshold(memcg
, type
== _MEMSWAP
);
5640 size
= thresholds
->primary
? thresholds
->primary
->size
+ 1 : 1;
5642 /* Allocate memory for new array of thresholds */
5643 new = kmalloc(sizeof(*new) + size
* sizeof(struct mem_cgroup_threshold
),
5651 /* Copy thresholds (if any) to new array */
5652 if (thresholds
->primary
) {
5653 memcpy(new->entries
, thresholds
->primary
->entries
, (size
- 1) *
5654 sizeof(struct mem_cgroup_threshold
));
5657 /* Add new threshold */
5658 new->entries
[size
- 1].eventfd
= eventfd
;
5659 new->entries
[size
- 1].threshold
= threshold
;
5661 /* Sort thresholds. Registering of new threshold isn't time-critical */
5662 sort(new->entries
, size
, sizeof(struct mem_cgroup_threshold
),
5663 compare_thresholds
, NULL
);
5665 /* Find current threshold */
5666 new->current_threshold
= -1;
5667 for (i
= 0; i
< size
; i
++) {
5668 if (new->entries
[i
].threshold
<= usage
) {
5670 * new->current_threshold will not be used until
5671 * rcu_assign_pointer(), so it's safe to increment
5674 ++new->current_threshold
;
5679 /* Free old spare buffer and save old primary buffer as spare */
5680 kfree(thresholds
->spare
);
5681 thresholds
->spare
= thresholds
->primary
;
5683 rcu_assign_pointer(thresholds
->primary
, new);
5685 /* To be sure that nobody uses thresholds */
5689 mutex_unlock(&memcg
->thresholds_lock
);
5694 static void mem_cgroup_usage_unregister_event(struct cgroup_subsys_state
*css
,
5695 struct cftype
*cft
, struct eventfd_ctx
*eventfd
)
5697 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
5698 struct mem_cgroup_thresholds
*thresholds
;
5699 struct mem_cgroup_threshold_ary
*new;
5700 enum res_type type
= MEMFILE_TYPE(cft
->private);
5704 mutex_lock(&memcg
->thresholds_lock
);
5706 thresholds
= &memcg
->thresholds
;
5707 else if (type
== _MEMSWAP
)
5708 thresholds
= &memcg
->memsw_thresholds
;
5712 if (!thresholds
->primary
)
5715 usage
= mem_cgroup_usage(memcg
, type
== _MEMSWAP
);
5717 /* Check if a threshold crossed before removing */
5718 __mem_cgroup_threshold(memcg
, type
== _MEMSWAP
);
5720 /* Calculate new number of threshold */
5722 for (i
= 0; i
< thresholds
->primary
->size
; i
++) {
5723 if (thresholds
->primary
->entries
[i
].eventfd
!= eventfd
)
5727 new = thresholds
->spare
;
5729 /* Set thresholds array to NULL if we don't have thresholds */
5738 /* Copy thresholds and find current threshold */
5739 new->current_threshold
= -1;
5740 for (i
= 0, j
= 0; i
< thresholds
->primary
->size
; i
++) {
5741 if (thresholds
->primary
->entries
[i
].eventfd
== eventfd
)
5744 new->entries
[j
] = thresholds
->primary
->entries
[i
];
5745 if (new->entries
[j
].threshold
<= usage
) {
5747 * new->current_threshold will not be used
5748 * until rcu_assign_pointer(), so it's safe to increment
5751 ++new->current_threshold
;
5757 /* Swap primary and spare array */
5758 thresholds
->spare
= thresholds
->primary
;
5759 /* If all events are unregistered, free the spare array */
5761 kfree(thresholds
->spare
);
5762 thresholds
->spare
= NULL
;
5765 rcu_assign_pointer(thresholds
->primary
, new);
5767 /* To be sure that nobody uses thresholds */
5770 mutex_unlock(&memcg
->thresholds_lock
);
5773 static int mem_cgroup_oom_register_event(struct cgroup_subsys_state
*css
,
5774 struct cftype
*cft
, struct eventfd_ctx
*eventfd
, const char *args
)
5776 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
5777 struct mem_cgroup_eventfd_list
*event
;
5778 enum res_type type
= MEMFILE_TYPE(cft
->private);
5780 BUG_ON(type
!= _OOM_TYPE
);
5781 event
= kmalloc(sizeof(*event
), GFP_KERNEL
);
5785 spin_lock(&memcg_oom_lock
);
5787 event
->eventfd
= eventfd
;
5788 list_add(&event
->list
, &memcg
->oom_notify
);
5790 /* already in OOM ? */
5791 if (atomic_read(&memcg
->under_oom
))
5792 eventfd_signal(eventfd
, 1);
5793 spin_unlock(&memcg_oom_lock
);
5798 static void mem_cgroup_oom_unregister_event(struct cgroup_subsys_state
*css
,
5799 struct cftype
*cft
, struct eventfd_ctx
*eventfd
)
5801 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
5802 struct mem_cgroup_eventfd_list
*ev
, *tmp
;
5803 enum res_type type
= MEMFILE_TYPE(cft
->private);
5805 BUG_ON(type
!= _OOM_TYPE
);
5807 spin_lock(&memcg_oom_lock
);
5809 list_for_each_entry_safe(ev
, tmp
, &memcg
->oom_notify
, list
) {
5810 if (ev
->eventfd
== eventfd
) {
5811 list_del(&ev
->list
);
5816 spin_unlock(&memcg_oom_lock
);
5819 static int mem_cgroup_oom_control_read(struct cgroup_subsys_state
*css
,
5820 struct cftype
*cft
, struct cgroup_map_cb
*cb
)
5822 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
5824 cb
->fill(cb
, "oom_kill_disable", memcg
->oom_kill_disable
);
5826 if (atomic_read(&memcg
->under_oom
))
5827 cb
->fill(cb
, "under_oom", 1);
5829 cb
->fill(cb
, "under_oom", 0);
5833 static int mem_cgroup_oom_control_write(struct cgroup_subsys_state
*css
,
5834 struct cftype
*cft
, u64 val
)
5836 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
5837 struct mem_cgroup
*parent
= mem_cgroup_from_css(css_parent(&memcg
->css
));
5839 /* cannot set to root cgroup and only 0 and 1 are allowed */
5840 if (!parent
|| !((val
== 0) || (val
== 1)))
5843 mutex_lock(&memcg_create_mutex
);
5844 /* oom-kill-disable is a flag for subhierarchy. */
5845 if ((parent
->use_hierarchy
) || memcg_has_children(memcg
)) {
5846 mutex_unlock(&memcg_create_mutex
);
5849 memcg
->oom_kill_disable
= val
;
5851 memcg_oom_recover(memcg
);
5852 mutex_unlock(&memcg_create_mutex
);
5856 #ifdef CONFIG_MEMCG_KMEM
5857 static int memcg_init_kmem(struct mem_cgroup
*memcg
, struct cgroup_subsys
*ss
)
5861 memcg
->kmemcg_id
= -1;
5862 ret
= memcg_propagate_kmem(memcg
);
5866 return mem_cgroup_sockets_init(memcg
, ss
);
5869 static void memcg_destroy_kmem(struct mem_cgroup
*memcg
)
5871 mem_cgroup_sockets_destroy(memcg
);
5874 static void kmem_cgroup_css_offline(struct mem_cgroup
*memcg
)
5876 if (!memcg_kmem_is_active(memcg
))
5880 * kmem charges can outlive the cgroup. In the case of slab
5881 * pages, for instance, a page contain objects from various
5882 * processes. As we prevent from taking a reference for every
5883 * such allocation we have to be careful when doing uncharge
5884 * (see memcg_uncharge_kmem) and here during offlining.
5886 * The idea is that that only the _last_ uncharge which sees
5887 * the dead memcg will drop the last reference. An additional
5888 * reference is taken here before the group is marked dead
5889 * which is then paired with css_put during uncharge resp. here.
5891 * Although this might sound strange as this path is called from
5892 * css_offline() when the referencemight have dropped down to 0
5893 * and shouldn't be incremented anymore (css_tryget would fail)
5894 * we do not have other options because of the kmem allocations
5897 css_get(&memcg
->css
);
5899 memcg_kmem_mark_dead(memcg
);
5901 if (res_counter_read_u64(&memcg
->kmem
, RES_USAGE
) != 0)
5904 if (memcg_kmem_test_and_clear_dead(memcg
))
5905 css_put(&memcg
->css
);
5908 static int memcg_init_kmem(struct mem_cgroup
*memcg
, struct cgroup_subsys
*ss
)
5913 static void memcg_destroy_kmem(struct mem_cgroup
*memcg
)
5917 static void kmem_cgroup_css_offline(struct mem_cgroup
*memcg
)
5922 static struct cftype mem_cgroup_files
[] = {
5924 .name
= "usage_in_bytes",
5925 .private = MEMFILE_PRIVATE(_MEM
, RES_USAGE
),
5926 .read
= mem_cgroup_read
,
5927 .register_event
= mem_cgroup_usage_register_event
,
5928 .unregister_event
= mem_cgroup_usage_unregister_event
,
5931 .name
= "max_usage_in_bytes",
5932 .private = MEMFILE_PRIVATE(_MEM
, RES_MAX_USAGE
),
5933 .trigger
= mem_cgroup_reset
,
5934 .read
= mem_cgroup_read
,
5937 .name
= "limit_in_bytes",
5938 .private = MEMFILE_PRIVATE(_MEM
, RES_LIMIT
),
5939 .write_string
= mem_cgroup_write
,
5940 .read
= mem_cgroup_read
,
5943 .name
= "soft_limit_in_bytes",
5944 .private = MEMFILE_PRIVATE(_MEM
, RES_SOFT_LIMIT
),
5945 .write_string
= mem_cgroup_write
,
5946 .read
= mem_cgroup_read
,
5950 .private = MEMFILE_PRIVATE(_MEM
, RES_FAILCNT
),
5951 .trigger
= mem_cgroup_reset
,
5952 .read
= mem_cgroup_read
,
5956 .read_seq_string
= memcg_stat_show
,
5959 .name
= "force_empty",
5960 .trigger
= mem_cgroup_force_empty_write
,
5963 .name
= "use_hierarchy",
5964 .flags
= CFTYPE_INSANE
,
5965 .write_u64
= mem_cgroup_hierarchy_write
,
5966 .read_u64
= mem_cgroup_hierarchy_read
,
5969 .name
= "swappiness",
5970 .read_u64
= mem_cgroup_swappiness_read
,
5971 .write_u64
= mem_cgroup_swappiness_write
,
5974 .name
= "move_charge_at_immigrate",
5975 .read_u64
= mem_cgroup_move_charge_read
,
5976 .write_u64
= mem_cgroup_move_charge_write
,
5979 .name
= "oom_control",
5980 .read_map
= mem_cgroup_oom_control_read
,
5981 .write_u64
= mem_cgroup_oom_control_write
,
5982 .register_event
= mem_cgroup_oom_register_event
,
5983 .unregister_event
= mem_cgroup_oom_unregister_event
,
5984 .private = MEMFILE_PRIVATE(_OOM_TYPE
, OOM_CONTROL
),
5987 .name
= "pressure_level",
5988 .register_event
= vmpressure_register_event
,
5989 .unregister_event
= vmpressure_unregister_event
,
5993 .name
= "numa_stat",
5994 .read_seq_string
= memcg_numa_stat_show
,
5997 #ifdef CONFIG_MEMCG_KMEM
5999 .name
= "kmem.limit_in_bytes",
6000 .private = MEMFILE_PRIVATE(_KMEM
, RES_LIMIT
),
6001 .write_string
= mem_cgroup_write
,
6002 .read
= mem_cgroup_read
,
6005 .name
= "kmem.usage_in_bytes",
6006 .private = MEMFILE_PRIVATE(_KMEM
, RES_USAGE
),
6007 .read
= mem_cgroup_read
,
6010 .name
= "kmem.failcnt",
6011 .private = MEMFILE_PRIVATE(_KMEM
, RES_FAILCNT
),
6012 .trigger
= mem_cgroup_reset
,
6013 .read
= mem_cgroup_read
,
6016 .name
= "kmem.max_usage_in_bytes",
6017 .private = MEMFILE_PRIVATE(_KMEM
, RES_MAX_USAGE
),
6018 .trigger
= mem_cgroup_reset
,
6019 .read
= mem_cgroup_read
,
6021 #ifdef CONFIG_SLABINFO
6023 .name
= "kmem.slabinfo",
6024 .read_seq_string
= mem_cgroup_slabinfo_read
,
6028 { }, /* terminate */
6031 #ifdef CONFIG_MEMCG_SWAP
6032 static struct cftype memsw_cgroup_files
[] = {
6034 .name
= "memsw.usage_in_bytes",
6035 .private = MEMFILE_PRIVATE(_MEMSWAP
, RES_USAGE
),
6036 .read
= mem_cgroup_read
,
6037 .register_event
= mem_cgroup_usage_register_event
,
6038 .unregister_event
= mem_cgroup_usage_unregister_event
,
6041 .name
= "memsw.max_usage_in_bytes",
6042 .private = MEMFILE_PRIVATE(_MEMSWAP
, RES_MAX_USAGE
),
6043 .trigger
= mem_cgroup_reset
,
6044 .read
= mem_cgroup_read
,
6047 .name
= "memsw.limit_in_bytes",
6048 .private = MEMFILE_PRIVATE(_MEMSWAP
, RES_LIMIT
),
6049 .write_string
= mem_cgroup_write
,
6050 .read
= mem_cgroup_read
,
6053 .name
= "memsw.failcnt",
6054 .private = MEMFILE_PRIVATE(_MEMSWAP
, RES_FAILCNT
),
6055 .trigger
= mem_cgroup_reset
,
6056 .read
= mem_cgroup_read
,
6058 { }, /* terminate */
6061 static int alloc_mem_cgroup_per_zone_info(struct mem_cgroup
*memcg
, int node
)
6063 struct mem_cgroup_per_node
*pn
;
6064 struct mem_cgroup_per_zone
*mz
;
6065 int zone
, tmp
= node
;
6067 * This routine is called against possible nodes.
6068 * But it's BUG to call kmalloc() against offline node.
6070 * TODO: this routine can waste much memory for nodes which will
6071 * never be onlined. It's better to use memory hotplug callback
6074 if (!node_state(node
, N_NORMAL_MEMORY
))
6076 pn
= kzalloc_node(sizeof(*pn
), GFP_KERNEL
, tmp
);
6080 for (zone
= 0; zone
< MAX_NR_ZONES
; zone
++) {
6081 mz
= &pn
->zoneinfo
[zone
];
6082 lruvec_init(&mz
->lruvec
);
6083 mz
->usage_in_excess
= 0;
6084 mz
->on_tree
= false;
6087 memcg
->nodeinfo
[node
] = pn
;
6091 static void free_mem_cgroup_per_zone_info(struct mem_cgroup
*memcg
, int node
)
6093 kfree(memcg
->nodeinfo
[node
]);
6096 static struct mem_cgroup
*mem_cgroup_alloc(void)
6098 struct mem_cgroup
*memcg
;
6099 size_t size
= memcg_size();
6101 /* Can be very big if nr_node_ids is very big */
6102 if (size
< PAGE_SIZE
)
6103 memcg
= kzalloc(size
, GFP_KERNEL
);
6105 memcg
= vzalloc(size
);
6110 memcg
->stat
= alloc_percpu(struct mem_cgroup_stat_cpu
);
6113 spin_lock_init(&memcg
->pcp_counter_lock
);
6117 if (size
< PAGE_SIZE
)
6125 * At destroying mem_cgroup, references from swap_cgroup can remain.
6126 * (scanning all at force_empty is too costly...)
6128 * Instead of clearing all references at force_empty, we remember
6129 * the number of reference from swap_cgroup and free mem_cgroup when
6130 * it goes down to 0.
6132 * Removal of cgroup itself succeeds regardless of refs from swap.
6135 static void __mem_cgroup_free(struct mem_cgroup
*memcg
)
6138 size_t size
= memcg_size();
6140 mem_cgroup_remove_from_trees(memcg
);
6141 free_css_id(&mem_cgroup_subsys
, &memcg
->css
);
6144 free_mem_cgroup_per_zone_info(memcg
, node
);
6146 free_percpu(memcg
->stat
);
6149 * We need to make sure that (at least for now), the jump label
6150 * destruction code runs outside of the cgroup lock. This is because
6151 * get_online_cpus(), which is called from the static_branch update,
6152 * can't be called inside the cgroup_lock. cpusets are the ones
6153 * enforcing this dependency, so if they ever change, we might as well.
6155 * schedule_work() will guarantee this happens. Be careful if you need
6156 * to move this code around, and make sure it is outside
6159 disarm_static_keys(memcg
);
6160 if (size
< PAGE_SIZE
)
6167 * Returns the parent mem_cgroup in memcgroup hierarchy with hierarchy enabled.
6169 struct mem_cgroup
*parent_mem_cgroup(struct mem_cgroup
*memcg
)
6171 if (!memcg
->res
.parent
)
6173 return mem_cgroup_from_res_counter(memcg
->res
.parent
, res
);
6175 EXPORT_SYMBOL(parent_mem_cgroup
);
6177 static void __init
mem_cgroup_soft_limit_tree_init(void)
6179 struct mem_cgroup_tree_per_node
*rtpn
;
6180 struct mem_cgroup_tree_per_zone
*rtpz
;
6181 int tmp
, node
, zone
;
6183 for_each_node(node
) {
6185 if (!node_state(node
, N_NORMAL_MEMORY
))
6187 rtpn
= kzalloc_node(sizeof(*rtpn
), GFP_KERNEL
, tmp
);
6190 soft_limit_tree
.rb_tree_per_node
[node
] = rtpn
;
6192 for (zone
= 0; zone
< MAX_NR_ZONES
; zone
++) {
6193 rtpz
= &rtpn
->rb_tree_per_zone
[zone
];
6194 rtpz
->rb_root
= RB_ROOT
;
6195 spin_lock_init(&rtpz
->lock
);
6200 static struct cgroup_subsys_state
* __ref
6201 mem_cgroup_css_alloc(struct cgroup_subsys_state
*parent_css
)
6203 struct mem_cgroup
*memcg
;
6204 long error
= -ENOMEM
;
6207 memcg
= mem_cgroup_alloc();
6209 return ERR_PTR(error
);
6212 if (alloc_mem_cgroup_per_zone_info(memcg
, node
))
6216 if (parent_css
== NULL
) {
6217 root_mem_cgroup
= memcg
;
6218 res_counter_init(&memcg
->res
, NULL
);
6219 res_counter_init(&memcg
->memsw
, NULL
);
6220 res_counter_init(&memcg
->kmem
, NULL
);
6223 memcg
->last_scanned_node
= MAX_NUMNODES
;
6224 INIT_LIST_HEAD(&memcg
->oom_notify
);
6225 memcg
->move_charge_at_immigrate
= 0;
6226 mutex_init(&memcg
->thresholds_lock
);
6227 spin_lock_init(&memcg
->move_lock
);
6228 vmpressure_init(&memcg
->vmpressure
);
6233 __mem_cgroup_free(memcg
);
6234 return ERR_PTR(error
);
6238 mem_cgroup_css_online(struct cgroup_subsys_state
*css
)
6240 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
6241 struct mem_cgroup
*parent
= mem_cgroup_from_css(css_parent(css
));
6247 mutex_lock(&memcg_create_mutex
);
6249 memcg
->use_hierarchy
= parent
->use_hierarchy
;
6250 memcg
->oom_kill_disable
= parent
->oom_kill_disable
;
6251 memcg
->swappiness
= mem_cgroup_swappiness(parent
);
6253 if (parent
->use_hierarchy
) {
6254 res_counter_init(&memcg
->res
, &parent
->res
);
6255 res_counter_init(&memcg
->memsw
, &parent
->memsw
);
6256 res_counter_init(&memcg
->kmem
, &parent
->kmem
);
6259 * No need to take a reference to the parent because cgroup
6260 * core guarantees its existence.
6263 res_counter_init(&memcg
->res
, NULL
);
6264 res_counter_init(&memcg
->memsw
, NULL
);
6265 res_counter_init(&memcg
->kmem
, NULL
);
6267 * Deeper hierachy with use_hierarchy == false doesn't make
6268 * much sense so let cgroup subsystem know about this
6269 * unfortunate state in our controller.
6271 if (parent
!= root_mem_cgroup
)
6272 mem_cgroup_subsys
.broken_hierarchy
= true;
6275 error
= memcg_init_kmem(memcg
, &mem_cgroup_subsys
);
6276 mutex_unlock(&memcg_create_mutex
);
6281 * Announce all parents that a group from their hierarchy is gone.
6283 static void mem_cgroup_invalidate_reclaim_iterators(struct mem_cgroup
*memcg
)
6285 struct mem_cgroup
*parent
= memcg
;
6287 while ((parent
= parent_mem_cgroup(parent
)))
6288 mem_cgroup_iter_invalidate(parent
);
6291 * if the root memcg is not hierarchical we have to check it
6294 if (!root_mem_cgroup
->use_hierarchy
)
6295 mem_cgroup_iter_invalidate(root_mem_cgroup
);
6298 static void mem_cgroup_css_offline(struct cgroup_subsys_state
*css
)
6300 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
6302 kmem_cgroup_css_offline(memcg
);
6304 mem_cgroup_invalidate_reclaim_iterators(memcg
);
6305 mem_cgroup_reparent_charges(memcg
);
6306 mem_cgroup_destroy_all_caches(memcg
);
6307 vmpressure_cleanup(&memcg
->vmpressure
);
6310 static void mem_cgroup_css_free(struct cgroup_subsys_state
*css
)
6312 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
6314 memcg_destroy_kmem(memcg
);
6315 __mem_cgroup_free(memcg
);
6319 /* Handlers for move charge at task migration. */
6320 #define PRECHARGE_COUNT_AT_ONCE 256
6321 static int mem_cgroup_do_precharge(unsigned long count
)
6324 int batch_count
= PRECHARGE_COUNT_AT_ONCE
;
6325 struct mem_cgroup
*memcg
= mc
.to
;
6327 if (mem_cgroup_is_root(memcg
)) {
6328 mc
.precharge
+= count
;
6329 /* we don't need css_get for root */
6332 /* try to charge at once */
6334 struct res_counter
*dummy
;
6336 * "memcg" cannot be under rmdir() because we've already checked
6337 * by cgroup_lock_live_cgroup() that it is not removed and we
6338 * are still under the same cgroup_mutex. So we can postpone
6341 if (res_counter_charge(&memcg
->res
, PAGE_SIZE
* count
, &dummy
))
6343 if (do_swap_account
&& res_counter_charge(&memcg
->memsw
,
6344 PAGE_SIZE
* count
, &dummy
)) {
6345 res_counter_uncharge(&memcg
->res
, PAGE_SIZE
* count
);
6348 mc
.precharge
+= count
;
6352 /* fall back to one by one charge */
6354 if (signal_pending(current
)) {
6358 if (!batch_count
--) {
6359 batch_count
= PRECHARGE_COUNT_AT_ONCE
;
6362 ret
= __mem_cgroup_try_charge(NULL
,
6363 GFP_KERNEL
, 1, &memcg
, false);
6365 /* mem_cgroup_clear_mc() will do uncharge later */
6373 * get_mctgt_type - get target type of moving charge
6374 * @vma: the vma the pte to be checked belongs
6375 * @addr: the address corresponding to the pte to be checked
6376 * @ptent: the pte to be checked
6377 * @target: the pointer the target page or swap ent will be stored(can be NULL)
6380 * 0(MC_TARGET_NONE): if the pte is not a target for move charge.
6381 * 1(MC_TARGET_PAGE): if the page corresponding to this pte is a target for
6382 * move charge. if @target is not NULL, the page is stored in target->page
6383 * with extra refcnt got(Callers should handle it).
6384 * 2(MC_TARGET_SWAP): if the swap entry corresponding to this pte is a
6385 * target for charge migration. if @target is not NULL, the entry is stored
6388 * Called with pte lock held.
6395 enum mc_target_type
{
6401 static struct page
*mc_handle_present_pte(struct vm_area_struct
*vma
,
6402 unsigned long addr
, pte_t ptent
)
6404 struct page
*page
= vm_normal_page(vma
, addr
, ptent
);
6406 if (!page
|| !page_mapped(page
))
6408 if (PageAnon(page
)) {
6409 /* we don't move shared anon */
6412 } else if (!move_file())
6413 /* we ignore mapcount for file pages */
6415 if (!get_page_unless_zero(page
))
6422 static struct page
*mc_handle_swap_pte(struct vm_area_struct
*vma
,
6423 unsigned long addr
, pte_t ptent
, swp_entry_t
*entry
)
6425 struct page
*page
= NULL
;
6426 swp_entry_t ent
= pte_to_swp_entry(ptent
);
6428 if (!move_anon() || non_swap_entry(ent
))
6431 * Because lookup_swap_cache() updates some statistics counter,
6432 * we call find_get_page() with swapper_space directly.
6434 page
= find_get_page(swap_address_space(ent
), ent
.val
);
6435 if (do_swap_account
)
6436 entry
->val
= ent
.val
;
6441 static struct page
*mc_handle_swap_pte(struct vm_area_struct
*vma
,
6442 unsigned long addr
, pte_t ptent
, swp_entry_t
*entry
)
6448 static struct page
*mc_handle_file_pte(struct vm_area_struct
*vma
,
6449 unsigned long addr
, pte_t ptent
, swp_entry_t
*entry
)
6451 struct page
*page
= NULL
;
6452 struct address_space
*mapping
;
6455 if (!vma
->vm_file
) /* anonymous vma */
6460 mapping
= vma
->vm_file
->f_mapping
;
6461 if (pte_none(ptent
))
6462 pgoff
= linear_page_index(vma
, addr
);
6463 else /* pte_file(ptent) is true */
6464 pgoff
= pte_to_pgoff(ptent
);
6466 /* page is moved even if it's not RSS of this task(page-faulted). */
6467 page
= find_get_page(mapping
, pgoff
);
6470 /* shmem/tmpfs may report page out on swap: account for that too. */
6471 if (radix_tree_exceptional_entry(page
)) {
6472 swp_entry_t swap
= radix_to_swp_entry(page
);
6473 if (do_swap_account
)
6475 page
= find_get_page(swap_address_space(swap
), swap
.val
);
6481 static enum mc_target_type
get_mctgt_type(struct vm_area_struct
*vma
,
6482 unsigned long addr
, pte_t ptent
, union mc_target
*target
)
6484 struct page
*page
= NULL
;
6485 struct page_cgroup
*pc
;
6486 enum mc_target_type ret
= MC_TARGET_NONE
;
6487 swp_entry_t ent
= { .val
= 0 };
6489 if (pte_present(ptent
))
6490 page
= mc_handle_present_pte(vma
, addr
, ptent
);
6491 else if (is_swap_pte(ptent
))
6492 page
= mc_handle_swap_pte(vma
, addr
, ptent
, &ent
);
6493 else if (pte_none(ptent
) || pte_file(ptent
))
6494 page
= mc_handle_file_pte(vma
, addr
, ptent
, &ent
);
6496 if (!page
&& !ent
.val
)
6499 pc
= lookup_page_cgroup(page
);
6501 * Do only loose check w/o page_cgroup lock.
6502 * mem_cgroup_move_account() checks the pc is valid or not under
6505 if (PageCgroupUsed(pc
) && pc
->mem_cgroup
== mc
.from
) {
6506 ret
= MC_TARGET_PAGE
;
6508 target
->page
= page
;
6510 if (!ret
|| !target
)
6513 /* There is a swap entry and a page doesn't exist or isn't charged */
6514 if (ent
.val
&& !ret
&&
6515 css_id(&mc
.from
->css
) == lookup_swap_cgroup_id(ent
)) {
6516 ret
= MC_TARGET_SWAP
;
6523 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
6525 * We don't consider swapping or file mapped pages because THP does not
6526 * support them for now.
6527 * Caller should make sure that pmd_trans_huge(pmd) is true.
6529 static enum mc_target_type
get_mctgt_type_thp(struct vm_area_struct
*vma
,
6530 unsigned long addr
, pmd_t pmd
, union mc_target
*target
)
6532 struct page
*page
= NULL
;
6533 struct page_cgroup
*pc
;
6534 enum mc_target_type ret
= MC_TARGET_NONE
;
6536 page
= pmd_page(pmd
);
6537 VM_BUG_ON(!page
|| !PageHead(page
));
6540 pc
= lookup_page_cgroup(page
);
6541 if (PageCgroupUsed(pc
) && pc
->mem_cgroup
== mc
.from
) {
6542 ret
= MC_TARGET_PAGE
;
6545 target
->page
= page
;
6551 static inline enum mc_target_type
get_mctgt_type_thp(struct vm_area_struct
*vma
,
6552 unsigned long addr
, pmd_t pmd
, union mc_target
*target
)
6554 return MC_TARGET_NONE
;
6558 static int mem_cgroup_count_precharge_pte_range(pmd_t
*pmd
,
6559 unsigned long addr
, unsigned long end
,
6560 struct mm_walk
*walk
)
6562 struct vm_area_struct
*vma
= walk
->private;
6566 if (pmd_trans_huge_lock(pmd
, vma
) == 1) {
6567 if (get_mctgt_type_thp(vma
, addr
, *pmd
, NULL
) == MC_TARGET_PAGE
)
6568 mc
.precharge
+= HPAGE_PMD_NR
;
6569 spin_unlock(&vma
->vm_mm
->page_table_lock
);
6573 if (pmd_trans_unstable(pmd
))
6575 pte
= pte_offset_map_lock(vma
->vm_mm
, pmd
, addr
, &ptl
);
6576 for (; addr
!= end
; pte
++, addr
+= PAGE_SIZE
)
6577 if (get_mctgt_type(vma
, addr
, *pte
, NULL
))
6578 mc
.precharge
++; /* increment precharge temporarily */
6579 pte_unmap_unlock(pte
- 1, ptl
);
6585 static unsigned long mem_cgroup_count_precharge(struct mm_struct
*mm
)
6587 unsigned long precharge
;
6588 struct vm_area_struct
*vma
;
6590 down_read(&mm
->mmap_sem
);
6591 for (vma
= mm
->mmap
; vma
; vma
= vma
->vm_next
) {
6592 struct mm_walk mem_cgroup_count_precharge_walk
= {
6593 .pmd_entry
= mem_cgroup_count_precharge_pte_range
,
6597 if (is_vm_hugetlb_page(vma
))
6599 walk_page_range(vma
->vm_start
, vma
->vm_end
,
6600 &mem_cgroup_count_precharge_walk
);
6602 up_read(&mm
->mmap_sem
);
6604 precharge
= mc
.precharge
;
6610 static int mem_cgroup_precharge_mc(struct mm_struct
*mm
)
6612 unsigned long precharge
= mem_cgroup_count_precharge(mm
);
6614 VM_BUG_ON(mc
.moving_task
);
6615 mc
.moving_task
= current
;
6616 return mem_cgroup_do_precharge(precharge
);
6619 /* cancels all extra charges on mc.from and mc.to, and wakes up all waiters. */
6620 static void __mem_cgroup_clear_mc(void)
6622 struct mem_cgroup
*from
= mc
.from
;
6623 struct mem_cgroup
*to
= mc
.to
;
6626 /* we must uncharge all the leftover precharges from mc.to */
6628 __mem_cgroup_cancel_charge(mc
.to
, mc
.precharge
);
6632 * we didn't uncharge from mc.from at mem_cgroup_move_account(), so
6633 * we must uncharge here.
6635 if (mc
.moved_charge
) {
6636 __mem_cgroup_cancel_charge(mc
.from
, mc
.moved_charge
);
6637 mc
.moved_charge
= 0;
6639 /* we must fixup refcnts and charges */
6640 if (mc
.moved_swap
) {
6641 /* uncharge swap account from the old cgroup */
6642 if (!mem_cgroup_is_root(mc
.from
))
6643 res_counter_uncharge(&mc
.from
->memsw
,
6644 PAGE_SIZE
* mc
.moved_swap
);
6646 for (i
= 0; i
< mc
.moved_swap
; i
++)
6647 css_put(&mc
.from
->css
);
6649 if (!mem_cgroup_is_root(mc
.to
)) {
6651 * we charged both to->res and to->memsw, so we should
6654 res_counter_uncharge(&mc
.to
->res
,
6655 PAGE_SIZE
* mc
.moved_swap
);
6657 /* we've already done css_get(mc.to) */
6660 memcg_oom_recover(from
);
6661 memcg_oom_recover(to
);
6662 wake_up_all(&mc
.waitq
);
6665 static void mem_cgroup_clear_mc(void)
6667 struct mem_cgroup
*from
= mc
.from
;
6670 * we must clear moving_task before waking up waiters at the end of
6673 mc
.moving_task
= NULL
;
6674 __mem_cgroup_clear_mc();
6675 spin_lock(&mc
.lock
);
6678 spin_unlock(&mc
.lock
);
6679 mem_cgroup_end_move(from
);
6682 static int mem_cgroup_can_attach(struct cgroup_subsys_state
*css
,
6683 struct cgroup_taskset
*tset
)
6685 struct task_struct
*p
= cgroup_taskset_first(tset
);
6687 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
6688 unsigned long move_charge_at_immigrate
;
6691 * We are now commited to this value whatever it is. Changes in this
6692 * tunable will only affect upcoming migrations, not the current one.
6693 * So we need to save it, and keep it going.
6695 move_charge_at_immigrate
= memcg
->move_charge_at_immigrate
;
6696 if (move_charge_at_immigrate
) {
6697 struct mm_struct
*mm
;
6698 struct mem_cgroup
*from
= mem_cgroup_from_task(p
);
6700 VM_BUG_ON(from
== memcg
);
6702 mm
= get_task_mm(p
);
6705 /* We move charges only when we move a owner of the mm */
6706 if (mm
->owner
== p
) {
6709 VM_BUG_ON(mc
.precharge
);
6710 VM_BUG_ON(mc
.moved_charge
);
6711 VM_BUG_ON(mc
.moved_swap
);
6712 mem_cgroup_start_move(from
);
6713 spin_lock(&mc
.lock
);
6716 mc
.immigrate_flags
= move_charge_at_immigrate
;
6717 spin_unlock(&mc
.lock
);
6718 /* We set mc.moving_task later */
6720 ret
= mem_cgroup_precharge_mc(mm
);
6722 mem_cgroup_clear_mc();
6729 static void mem_cgroup_cancel_attach(struct cgroup_subsys_state
*css
,
6730 struct cgroup_taskset
*tset
)
6732 mem_cgroup_clear_mc();
6735 static int mem_cgroup_move_charge_pte_range(pmd_t
*pmd
,
6736 unsigned long addr
, unsigned long end
,
6737 struct mm_walk
*walk
)
6740 struct vm_area_struct
*vma
= walk
->private;
6743 enum mc_target_type target_type
;
6744 union mc_target target
;
6746 struct page_cgroup
*pc
;
6749 * We don't take compound_lock() here but no race with splitting thp
6751 * - if pmd_trans_huge_lock() returns 1, the relevant thp is not
6752 * under splitting, which means there's no concurrent thp split,
6753 * - if another thread runs into split_huge_page() just after we
6754 * entered this if-block, the thread must wait for page table lock
6755 * to be unlocked in __split_huge_page_splitting(), where the main
6756 * part of thp split is not executed yet.
6758 if (pmd_trans_huge_lock(pmd
, vma
) == 1) {
6759 if (mc
.precharge
< HPAGE_PMD_NR
) {
6760 spin_unlock(&vma
->vm_mm
->page_table_lock
);
6763 target_type
= get_mctgt_type_thp(vma
, addr
, *pmd
, &target
);
6764 if (target_type
== MC_TARGET_PAGE
) {
6766 if (!isolate_lru_page(page
)) {
6767 pc
= lookup_page_cgroup(page
);
6768 if (!mem_cgroup_move_account(page
, HPAGE_PMD_NR
,
6769 pc
, mc
.from
, mc
.to
)) {
6770 mc
.precharge
-= HPAGE_PMD_NR
;
6771 mc
.moved_charge
+= HPAGE_PMD_NR
;
6773 putback_lru_page(page
);
6777 spin_unlock(&vma
->vm_mm
->page_table_lock
);
6781 if (pmd_trans_unstable(pmd
))
6784 pte
= pte_offset_map_lock(vma
->vm_mm
, pmd
, addr
, &ptl
);
6785 for (; addr
!= end
; addr
+= PAGE_SIZE
) {
6786 pte_t ptent
= *(pte
++);
6792 switch (get_mctgt_type(vma
, addr
, ptent
, &target
)) {
6793 case MC_TARGET_PAGE
:
6795 if (isolate_lru_page(page
))
6797 pc
= lookup_page_cgroup(page
);
6798 if (!mem_cgroup_move_account(page
, 1, pc
,
6801 /* we uncharge from mc.from later. */
6804 putback_lru_page(page
);
6805 put
: /* get_mctgt_type() gets the page */
6808 case MC_TARGET_SWAP
:
6810 if (!mem_cgroup_move_swap_account(ent
, mc
.from
, mc
.to
)) {
6812 /* we fixup refcnts and charges later. */
6820 pte_unmap_unlock(pte
- 1, ptl
);
6825 * We have consumed all precharges we got in can_attach().
6826 * We try charge one by one, but don't do any additional
6827 * charges to mc.to if we have failed in charge once in attach()
6830 ret
= mem_cgroup_do_precharge(1);
6838 static void mem_cgroup_move_charge(struct mm_struct
*mm
)
6840 struct vm_area_struct
*vma
;
6842 lru_add_drain_all();
6844 if (unlikely(!down_read_trylock(&mm
->mmap_sem
))) {
6846 * Someone who are holding the mmap_sem might be waiting in
6847 * waitq. So we cancel all extra charges, wake up all waiters,
6848 * and retry. Because we cancel precharges, we might not be able
6849 * to move enough charges, but moving charge is a best-effort
6850 * feature anyway, so it wouldn't be a big problem.
6852 __mem_cgroup_clear_mc();
6856 for (vma
= mm
->mmap
; vma
; vma
= vma
->vm_next
) {
6858 struct mm_walk mem_cgroup_move_charge_walk
= {
6859 .pmd_entry
= mem_cgroup_move_charge_pte_range
,
6863 if (is_vm_hugetlb_page(vma
))
6865 ret
= walk_page_range(vma
->vm_start
, vma
->vm_end
,
6866 &mem_cgroup_move_charge_walk
);
6869 * means we have consumed all precharges and failed in
6870 * doing additional charge. Just abandon here.
6874 up_read(&mm
->mmap_sem
);
6877 static void mem_cgroup_move_task(struct cgroup_subsys_state
*css
,
6878 struct cgroup_taskset
*tset
)
6880 struct task_struct
*p
= cgroup_taskset_first(tset
);
6881 struct mm_struct
*mm
= get_task_mm(p
);
6885 mem_cgroup_move_charge(mm
);
6889 mem_cgroup_clear_mc();
6891 #else /* !CONFIG_MMU */
6892 static int mem_cgroup_can_attach(struct cgroup_subsys_state
*css
,
6893 struct cgroup_taskset
*tset
)
6897 static void mem_cgroup_cancel_attach(struct cgroup_subsys_state
*css
,
6898 struct cgroup_taskset
*tset
)
6901 static void mem_cgroup_move_task(struct cgroup_subsys_state
*css
,
6902 struct cgroup_taskset
*tset
)
6908 * Cgroup retains root cgroups across [un]mount cycles making it necessary
6909 * to verify sane_behavior flag on each mount attempt.
6911 static void mem_cgroup_bind(struct cgroup_subsys_state
*root_css
)
6914 * use_hierarchy is forced with sane_behavior. cgroup core
6915 * guarantees that @root doesn't have any children, so turning it
6916 * on for the root memcg is enough.
6918 if (cgroup_sane_behavior(root_css
->cgroup
))
6919 mem_cgroup_from_css(root_css
)->use_hierarchy
= true;
6922 struct cgroup_subsys mem_cgroup_subsys
= {
6924 .subsys_id
= mem_cgroup_subsys_id
,
6925 .css_alloc
= mem_cgroup_css_alloc
,
6926 .css_online
= mem_cgroup_css_online
,
6927 .css_offline
= mem_cgroup_css_offline
,
6928 .css_free
= mem_cgroup_css_free
,
6929 .can_attach
= mem_cgroup_can_attach
,
6930 .cancel_attach
= mem_cgroup_cancel_attach
,
6931 .attach
= mem_cgroup_move_task
,
6932 .bind
= mem_cgroup_bind
,
6933 .base_cftypes
= mem_cgroup_files
,
6938 #ifdef CONFIG_MEMCG_SWAP
6939 static int __init
enable_swap_account(char *s
)
6941 if (!strcmp(s
, "1"))
6942 really_do_swap_account
= 1;
6943 else if (!strcmp(s
, "0"))
6944 really_do_swap_account
= 0;
6947 __setup("swapaccount=", enable_swap_account
);
6949 static void __init
memsw_file_init(void)
6951 WARN_ON(cgroup_add_cftypes(&mem_cgroup_subsys
, memsw_cgroup_files
));
6954 static void __init
enable_swap_cgroup(void)
6956 if (!mem_cgroup_disabled() && really_do_swap_account
) {
6957 do_swap_account
= 1;
6963 static void __init
enable_swap_cgroup(void)
6969 * subsys_initcall() for memory controller.
6971 * Some parts like hotcpu_notifier() have to be initialized from this context
6972 * because of lock dependencies (cgroup_lock -> cpu hotplug) but basically
6973 * everything that doesn't depend on a specific mem_cgroup structure should
6974 * be initialized from here.
6976 static int __init
mem_cgroup_init(void)
6978 hotcpu_notifier(memcg_cpu_hotplug_callback
, 0);
6979 enable_swap_cgroup();
6980 mem_cgroup_soft_limit_tree_init();
6984 subsys_initcall(mem_cgroup_init
);