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>
57 #include <linux/lockdep.h>
61 #include <net/tcp_memcontrol.h>
63 #include <asm/uaccess.h>
65 #include <trace/events/vmscan.h>
67 struct cgroup_subsys mem_cgroup_subsys __read_mostly
;
68 EXPORT_SYMBOL(mem_cgroup_subsys
);
70 #define MEM_CGROUP_RECLAIM_RETRIES 5
71 static struct mem_cgroup
*root_mem_cgroup __read_mostly
;
73 #ifdef CONFIG_MEMCG_SWAP
74 /* Turned on only when memory cgroup is enabled && really_do_swap_account = 1 */
75 int do_swap_account __read_mostly
;
77 /* for remember boot option*/
78 #ifdef CONFIG_MEMCG_SWAP_ENABLED
79 static int really_do_swap_account __initdata
= 1;
81 static int really_do_swap_account __initdata
= 0;
85 #define do_swap_account 0
89 static const char * const mem_cgroup_stat_names
[] = {
98 enum mem_cgroup_events_index
{
99 MEM_CGROUP_EVENTS_PGPGIN
, /* # of pages paged in */
100 MEM_CGROUP_EVENTS_PGPGOUT
, /* # of pages paged out */
101 MEM_CGROUP_EVENTS_PGFAULT
, /* # of page-faults */
102 MEM_CGROUP_EVENTS_PGMAJFAULT
, /* # of major page-faults */
103 MEM_CGROUP_EVENTS_NSTATS
,
106 static const char * const mem_cgroup_events_names
[] = {
113 static const char * const mem_cgroup_lru_names
[] = {
122 * Per memcg event counter is incremented at every pagein/pageout. With THP,
123 * it will be incremated by the number of pages. This counter is used for
124 * for trigger some periodic events. This is straightforward and better
125 * than using jiffies etc. to handle periodic memcg event.
127 enum mem_cgroup_events_target
{
128 MEM_CGROUP_TARGET_THRESH
,
129 MEM_CGROUP_TARGET_SOFTLIMIT
,
130 MEM_CGROUP_TARGET_NUMAINFO
,
133 #define THRESHOLDS_EVENTS_TARGET 128
134 #define SOFTLIMIT_EVENTS_TARGET 1024
135 #define NUMAINFO_EVENTS_TARGET 1024
137 struct mem_cgroup_stat_cpu
{
138 long count
[MEM_CGROUP_STAT_NSTATS
];
139 unsigned long events
[MEM_CGROUP_EVENTS_NSTATS
];
140 unsigned long nr_page_events
;
141 unsigned long targets
[MEM_CGROUP_NTARGETS
];
144 struct mem_cgroup_reclaim_iter
{
146 * last scanned hierarchy member. Valid only if last_dead_count
147 * matches memcg->dead_count of the hierarchy root group.
149 struct mem_cgroup
*last_visited
;
150 unsigned long last_dead_count
;
152 /* scan generation, increased every round-trip */
153 unsigned int generation
;
157 * per-zone information in memory controller.
159 struct mem_cgroup_per_zone
{
160 struct lruvec lruvec
;
161 unsigned long lru_size
[NR_LRU_LISTS
];
163 struct mem_cgroup_reclaim_iter reclaim_iter
[DEF_PRIORITY
+ 1];
165 struct rb_node tree_node
; /* RB tree node */
166 unsigned long long usage_in_excess
;/* Set to the value by which */
167 /* the soft limit is exceeded*/
169 struct mem_cgroup
*memcg
; /* Back pointer, we cannot */
170 /* use container_of */
173 struct mem_cgroup_per_node
{
174 struct mem_cgroup_per_zone zoneinfo
[MAX_NR_ZONES
];
178 * Cgroups above their limits are maintained in a RB-Tree, independent of
179 * their hierarchy representation
182 struct mem_cgroup_tree_per_zone
{
183 struct rb_root rb_root
;
187 struct mem_cgroup_tree_per_node
{
188 struct mem_cgroup_tree_per_zone rb_tree_per_zone
[MAX_NR_ZONES
];
191 struct mem_cgroup_tree
{
192 struct mem_cgroup_tree_per_node
*rb_tree_per_node
[MAX_NUMNODES
];
195 static struct mem_cgroup_tree soft_limit_tree __read_mostly
;
197 struct mem_cgroup_threshold
{
198 struct eventfd_ctx
*eventfd
;
203 struct mem_cgroup_threshold_ary
{
204 /* An array index points to threshold just below or equal to usage. */
205 int current_threshold
;
206 /* Size of entries[] */
208 /* Array of thresholds */
209 struct mem_cgroup_threshold entries
[0];
212 struct mem_cgroup_thresholds
{
213 /* Primary thresholds array */
214 struct mem_cgroup_threshold_ary
*primary
;
216 * Spare threshold array.
217 * This is needed to make mem_cgroup_unregister_event() "never fail".
218 * It must be able to store at least primary->size - 1 entries.
220 struct mem_cgroup_threshold_ary
*spare
;
224 struct mem_cgroup_eventfd_list
{
225 struct list_head list
;
226 struct eventfd_ctx
*eventfd
;
229 static void mem_cgroup_threshold(struct mem_cgroup
*memcg
);
230 static void mem_cgroup_oom_notify(struct mem_cgroup
*memcg
);
233 * The memory controller data structure. The memory controller controls both
234 * page cache and RSS per cgroup. We would eventually like to provide
235 * statistics based on the statistics developed by Rik Van Riel for clock-pro,
236 * to help the administrator determine what knobs to tune.
238 * TODO: Add a water mark for the memory controller. Reclaim will begin when
239 * we hit the water mark. May be even add a low water mark, such that
240 * no reclaim occurs from a cgroup at it's low water mark, this is
241 * a feature that will be implemented much later in the future.
244 struct cgroup_subsys_state css
;
246 * the counter to account for memory usage
248 struct res_counter res
;
250 /* vmpressure notifications */
251 struct vmpressure vmpressure
;
254 * the counter to account for mem+swap usage.
256 struct res_counter memsw
;
259 * the counter to account for kernel memory usage.
261 struct res_counter kmem
;
263 * Should the accounting and control be hierarchical, per subtree?
266 unsigned long kmem_account_flags
; /* See KMEM_ACCOUNTED_*, below */
270 atomic_t oom_wakeups
;
273 /* OOM-Killer disable */
274 int oom_kill_disable
;
276 /* set when res.limit == memsw.limit */
277 bool memsw_is_minimum
;
279 /* protect arrays of thresholds */
280 struct mutex thresholds_lock
;
282 /* thresholds for memory usage. RCU-protected */
283 struct mem_cgroup_thresholds thresholds
;
285 /* thresholds for mem+swap usage. RCU-protected */
286 struct mem_cgroup_thresholds memsw_thresholds
;
288 /* For oom notifier event fd */
289 struct list_head oom_notify
;
292 * Should we move charges of a task when a task is moved into this
293 * mem_cgroup ? And what type of charges should we move ?
295 unsigned long move_charge_at_immigrate
;
297 * set > 0 if pages under this cgroup are moving to other cgroup.
299 atomic_t moving_account
;
300 /* taken only while moving_account > 0 */
301 spinlock_t move_lock
;
305 struct mem_cgroup_stat_cpu __percpu
*stat
;
307 * used when a cpu is offlined or other synchronizations
308 * See mem_cgroup_read_stat().
310 struct mem_cgroup_stat_cpu nocpu_base
;
311 spinlock_t pcp_counter_lock
;
314 #if defined(CONFIG_MEMCG_KMEM) && defined(CONFIG_INET)
315 struct tcp_memcontrol tcp_mem
;
317 #if defined(CONFIG_MEMCG_KMEM)
318 /* analogous to slab_common's slab_caches list. per-memcg */
319 struct list_head memcg_slab_caches
;
320 /* Not a spinlock, we can take a lot of time walking the list */
321 struct mutex slab_caches_mutex
;
322 /* Index in the kmem_cache->memcg_params->memcg_caches array */
326 int last_scanned_node
;
328 nodemask_t scan_nodes
;
329 atomic_t numainfo_events
;
330 atomic_t numainfo_updating
;
333 struct mem_cgroup_per_node
*nodeinfo
[0];
334 /* WARNING: nodeinfo must be the last member here */
337 static size_t memcg_size(void)
339 return sizeof(struct mem_cgroup
) +
340 nr_node_ids
* sizeof(struct mem_cgroup_per_node
);
343 /* internal only representation about the status of kmem accounting. */
345 KMEM_ACCOUNTED_ACTIVE
= 0, /* accounted by this cgroup itself */
346 KMEM_ACCOUNTED_ACTIVATED
, /* static key enabled. */
347 KMEM_ACCOUNTED_DEAD
, /* dead memcg with pending kmem charges */
350 /* We account when limit is on, but only after call sites are patched */
351 #define KMEM_ACCOUNTED_MASK \
352 ((1 << KMEM_ACCOUNTED_ACTIVE) | (1 << KMEM_ACCOUNTED_ACTIVATED))
354 #ifdef CONFIG_MEMCG_KMEM
355 static inline void memcg_kmem_set_active(struct mem_cgroup
*memcg
)
357 set_bit(KMEM_ACCOUNTED_ACTIVE
, &memcg
->kmem_account_flags
);
360 static bool memcg_kmem_is_active(struct mem_cgroup
*memcg
)
362 return test_bit(KMEM_ACCOUNTED_ACTIVE
, &memcg
->kmem_account_flags
);
365 static void memcg_kmem_set_activated(struct mem_cgroup
*memcg
)
367 set_bit(KMEM_ACCOUNTED_ACTIVATED
, &memcg
->kmem_account_flags
);
370 static void memcg_kmem_clear_activated(struct mem_cgroup
*memcg
)
372 clear_bit(KMEM_ACCOUNTED_ACTIVATED
, &memcg
->kmem_account_flags
);
375 static void memcg_kmem_mark_dead(struct mem_cgroup
*memcg
)
378 * Our caller must use css_get() first, because memcg_uncharge_kmem()
379 * will call css_put() if it sees the memcg is dead.
382 if (test_bit(KMEM_ACCOUNTED_ACTIVE
, &memcg
->kmem_account_flags
))
383 set_bit(KMEM_ACCOUNTED_DEAD
, &memcg
->kmem_account_flags
);
386 static bool memcg_kmem_test_and_clear_dead(struct mem_cgroup
*memcg
)
388 return test_and_clear_bit(KMEM_ACCOUNTED_DEAD
,
389 &memcg
->kmem_account_flags
);
393 /* Stuffs for move charges at task migration. */
395 * Types of charges to be moved. "move_charge_at_immitgrate" and
396 * "immigrate_flags" are treated as a left-shifted bitmap of these types.
399 MOVE_CHARGE_TYPE_ANON
, /* private anonymous page and swap of it */
400 MOVE_CHARGE_TYPE_FILE
, /* file page(including tmpfs) and swap of it */
404 /* "mc" and its members are protected by cgroup_mutex */
405 static struct move_charge_struct
{
406 spinlock_t lock
; /* for from, to */
407 struct mem_cgroup
*from
;
408 struct mem_cgroup
*to
;
409 unsigned long immigrate_flags
;
410 unsigned long precharge
;
411 unsigned long moved_charge
;
412 unsigned long moved_swap
;
413 struct task_struct
*moving_task
; /* a task moving charges */
414 wait_queue_head_t waitq
; /* a waitq for other context */
416 .lock
= __SPIN_LOCK_UNLOCKED(mc
.lock
),
417 .waitq
= __WAIT_QUEUE_HEAD_INITIALIZER(mc
.waitq
),
420 static bool move_anon(void)
422 return test_bit(MOVE_CHARGE_TYPE_ANON
, &mc
.immigrate_flags
);
425 static bool move_file(void)
427 return test_bit(MOVE_CHARGE_TYPE_FILE
, &mc
.immigrate_flags
);
431 * Maximum loops in mem_cgroup_hierarchical_reclaim(), used for soft
432 * limit reclaim to prevent infinite loops, if they ever occur.
434 #define MEM_CGROUP_MAX_RECLAIM_LOOPS 100
435 #define MEM_CGROUP_MAX_SOFT_LIMIT_RECLAIM_LOOPS 2
438 MEM_CGROUP_CHARGE_TYPE_CACHE
= 0,
439 MEM_CGROUP_CHARGE_TYPE_ANON
,
440 MEM_CGROUP_CHARGE_TYPE_SWAPOUT
, /* for accounting swapcache */
441 MEM_CGROUP_CHARGE_TYPE_DROP
, /* a page was unused swap cache */
445 /* for encoding cft->private value on file */
453 #define MEMFILE_PRIVATE(x, val) ((x) << 16 | (val))
454 #define MEMFILE_TYPE(val) ((val) >> 16 & 0xffff)
455 #define MEMFILE_ATTR(val) ((val) & 0xffff)
456 /* Used for OOM nofiier */
457 #define OOM_CONTROL (0)
460 * Reclaim flags for mem_cgroup_hierarchical_reclaim
462 #define MEM_CGROUP_RECLAIM_NOSWAP_BIT 0x0
463 #define MEM_CGROUP_RECLAIM_NOSWAP (1 << MEM_CGROUP_RECLAIM_NOSWAP_BIT)
464 #define MEM_CGROUP_RECLAIM_SHRINK_BIT 0x1
465 #define MEM_CGROUP_RECLAIM_SHRINK (1 << MEM_CGROUP_RECLAIM_SHRINK_BIT)
468 * The memcg_create_mutex will be held whenever a new cgroup is created.
469 * As a consequence, any change that needs to protect against new child cgroups
470 * appearing has to hold it as well.
472 static DEFINE_MUTEX(memcg_create_mutex
);
474 struct mem_cgroup
*mem_cgroup_from_css(struct cgroup_subsys_state
*s
)
476 return s
? container_of(s
, struct mem_cgroup
, css
) : NULL
;
479 /* Some nice accessors for the vmpressure. */
480 struct vmpressure
*memcg_to_vmpressure(struct mem_cgroup
*memcg
)
483 memcg
= root_mem_cgroup
;
484 return &memcg
->vmpressure
;
487 struct cgroup_subsys_state
*vmpressure_to_css(struct vmpressure
*vmpr
)
489 return &container_of(vmpr
, struct mem_cgroup
, vmpressure
)->css
;
492 struct vmpressure
*css_to_vmpressure(struct cgroup_subsys_state
*css
)
494 return &mem_cgroup_from_css(css
)->vmpressure
;
497 static inline bool mem_cgroup_is_root(struct mem_cgroup
*memcg
)
499 return (memcg
== root_mem_cgroup
);
502 /* Writing them here to avoid exposing memcg's inner layout */
503 #if defined(CONFIG_INET) && defined(CONFIG_MEMCG_KMEM)
505 void sock_update_memcg(struct sock
*sk
)
507 if (mem_cgroup_sockets_enabled
) {
508 struct mem_cgroup
*memcg
;
509 struct cg_proto
*cg_proto
;
511 BUG_ON(!sk
->sk_prot
->proto_cgroup
);
513 /* Socket cloning can throw us here with sk_cgrp already
514 * filled. It won't however, necessarily happen from
515 * process context. So the test for root memcg given
516 * the current task's memcg won't help us in this case.
518 * Respecting the original socket's memcg is a better
519 * decision in this case.
522 BUG_ON(mem_cgroup_is_root(sk
->sk_cgrp
->memcg
));
523 css_get(&sk
->sk_cgrp
->memcg
->css
);
528 memcg
= mem_cgroup_from_task(current
);
529 cg_proto
= sk
->sk_prot
->proto_cgroup(memcg
);
530 if (!mem_cgroup_is_root(memcg
) &&
531 memcg_proto_active(cg_proto
) && css_tryget(&memcg
->css
)) {
532 sk
->sk_cgrp
= cg_proto
;
537 EXPORT_SYMBOL(sock_update_memcg
);
539 void sock_release_memcg(struct sock
*sk
)
541 if (mem_cgroup_sockets_enabled
&& sk
->sk_cgrp
) {
542 struct mem_cgroup
*memcg
;
543 WARN_ON(!sk
->sk_cgrp
->memcg
);
544 memcg
= sk
->sk_cgrp
->memcg
;
545 css_put(&sk
->sk_cgrp
->memcg
->css
);
549 struct cg_proto
*tcp_proto_cgroup(struct mem_cgroup
*memcg
)
551 if (!memcg
|| mem_cgroup_is_root(memcg
))
554 return &memcg
->tcp_mem
.cg_proto
;
556 EXPORT_SYMBOL(tcp_proto_cgroup
);
558 static void disarm_sock_keys(struct mem_cgroup
*memcg
)
560 if (!memcg_proto_activated(&memcg
->tcp_mem
.cg_proto
))
562 static_key_slow_dec(&memcg_socket_limit_enabled
);
565 static void disarm_sock_keys(struct mem_cgroup
*memcg
)
570 #ifdef CONFIG_MEMCG_KMEM
572 * This will be the memcg's index in each cache's ->memcg_params->memcg_caches.
573 * There are two main reasons for not using the css_id for this:
574 * 1) this works better in sparse environments, where we have a lot of memcgs,
575 * but only a few kmem-limited. Or also, if we have, for instance, 200
576 * memcgs, and none but the 200th is kmem-limited, we'd have to have a
577 * 200 entry array for that.
579 * 2) In order not to violate the cgroup API, we would like to do all memory
580 * allocation in ->create(). At that point, we haven't yet allocated the
581 * css_id. Having a separate index prevents us from messing with the cgroup
584 * The current size of the caches array is stored in
585 * memcg_limited_groups_array_size. It will double each time we have to
588 static DEFINE_IDA(kmem_limited_groups
);
589 int memcg_limited_groups_array_size
;
592 * MIN_SIZE is different than 1, because we would like to avoid going through
593 * the alloc/free process all the time. In a small machine, 4 kmem-limited
594 * cgroups is a reasonable guess. In the future, it could be a parameter or
595 * tunable, but that is strictly not necessary.
597 * MAX_SIZE should be as large as the number of css_ids. Ideally, we could get
598 * this constant directly from cgroup, but it is understandable that this is
599 * better kept as an internal representation in cgroup.c. In any case, the
600 * css_id space is not getting any smaller, and we don't have to necessarily
601 * increase ours as well if it increases.
603 #define MEMCG_CACHES_MIN_SIZE 4
604 #define MEMCG_CACHES_MAX_SIZE 65535
607 * A lot of the calls to the cache allocation functions are expected to be
608 * inlined by the compiler. Since the calls to memcg_kmem_get_cache are
609 * conditional to this static branch, we'll have to allow modules that does
610 * kmem_cache_alloc and the such to see this symbol as well
612 struct static_key memcg_kmem_enabled_key
;
613 EXPORT_SYMBOL(memcg_kmem_enabled_key
);
615 static void disarm_kmem_keys(struct mem_cgroup
*memcg
)
617 if (memcg_kmem_is_active(memcg
)) {
618 static_key_slow_dec(&memcg_kmem_enabled_key
);
619 ida_simple_remove(&kmem_limited_groups
, memcg
->kmemcg_id
);
622 * This check can't live in kmem destruction function,
623 * since the charges will outlive the cgroup
625 WARN_ON(res_counter_read_u64(&memcg
->kmem
, RES_USAGE
) != 0);
628 static void disarm_kmem_keys(struct mem_cgroup
*memcg
)
631 #endif /* CONFIG_MEMCG_KMEM */
633 static void disarm_static_keys(struct mem_cgroup
*memcg
)
635 disarm_sock_keys(memcg
);
636 disarm_kmem_keys(memcg
);
639 static void drain_all_stock_async(struct mem_cgroup
*memcg
);
641 static struct mem_cgroup_per_zone
*
642 mem_cgroup_zoneinfo(struct mem_cgroup
*memcg
, int nid
, int zid
)
644 VM_BUG_ON((unsigned)nid
>= nr_node_ids
);
645 return &memcg
->nodeinfo
[nid
]->zoneinfo
[zid
];
648 struct cgroup_subsys_state
*mem_cgroup_css(struct mem_cgroup
*memcg
)
653 static struct mem_cgroup_per_zone
*
654 page_cgroup_zoneinfo(struct mem_cgroup
*memcg
, struct page
*page
)
656 int nid
= page_to_nid(page
);
657 int zid
= page_zonenum(page
);
659 return mem_cgroup_zoneinfo(memcg
, nid
, zid
);
662 static struct mem_cgroup_tree_per_zone
*
663 soft_limit_tree_node_zone(int nid
, int zid
)
665 return &soft_limit_tree
.rb_tree_per_node
[nid
]->rb_tree_per_zone
[zid
];
668 static struct mem_cgroup_tree_per_zone
*
669 soft_limit_tree_from_page(struct page
*page
)
671 int nid
= page_to_nid(page
);
672 int zid
= page_zonenum(page
);
674 return &soft_limit_tree
.rb_tree_per_node
[nid
]->rb_tree_per_zone
[zid
];
678 __mem_cgroup_insert_exceeded(struct mem_cgroup
*memcg
,
679 struct mem_cgroup_per_zone
*mz
,
680 struct mem_cgroup_tree_per_zone
*mctz
,
681 unsigned long long new_usage_in_excess
)
683 struct rb_node
**p
= &mctz
->rb_root
.rb_node
;
684 struct rb_node
*parent
= NULL
;
685 struct mem_cgroup_per_zone
*mz_node
;
690 mz
->usage_in_excess
= new_usage_in_excess
;
691 if (!mz
->usage_in_excess
)
695 mz_node
= rb_entry(parent
, struct mem_cgroup_per_zone
,
697 if (mz
->usage_in_excess
< mz_node
->usage_in_excess
)
700 * We can't avoid mem cgroups that are over their soft
701 * limit by the same amount
703 else if (mz
->usage_in_excess
>= mz_node
->usage_in_excess
)
706 rb_link_node(&mz
->tree_node
, parent
, p
);
707 rb_insert_color(&mz
->tree_node
, &mctz
->rb_root
);
712 __mem_cgroup_remove_exceeded(struct mem_cgroup
*memcg
,
713 struct mem_cgroup_per_zone
*mz
,
714 struct mem_cgroup_tree_per_zone
*mctz
)
718 rb_erase(&mz
->tree_node
, &mctz
->rb_root
);
723 mem_cgroup_remove_exceeded(struct mem_cgroup
*memcg
,
724 struct mem_cgroup_per_zone
*mz
,
725 struct mem_cgroup_tree_per_zone
*mctz
)
727 spin_lock(&mctz
->lock
);
728 __mem_cgroup_remove_exceeded(memcg
, mz
, mctz
);
729 spin_unlock(&mctz
->lock
);
733 static void mem_cgroup_update_tree(struct mem_cgroup
*memcg
, struct page
*page
)
735 unsigned long long excess
;
736 struct mem_cgroup_per_zone
*mz
;
737 struct mem_cgroup_tree_per_zone
*mctz
;
738 int nid
= page_to_nid(page
);
739 int zid
= page_zonenum(page
);
740 mctz
= soft_limit_tree_from_page(page
);
743 * Necessary to update all ancestors when hierarchy is used.
744 * because their event counter is not touched.
746 for (; memcg
; memcg
= parent_mem_cgroup(memcg
)) {
747 mz
= mem_cgroup_zoneinfo(memcg
, nid
, zid
);
748 excess
= res_counter_soft_limit_excess(&memcg
->res
);
750 * We have to update the tree if mz is on RB-tree or
751 * mem is over its softlimit.
753 if (excess
|| mz
->on_tree
) {
754 spin_lock(&mctz
->lock
);
755 /* if on-tree, remove it */
757 __mem_cgroup_remove_exceeded(memcg
, mz
, mctz
);
759 * Insert again. mz->usage_in_excess will be updated.
760 * If excess is 0, no tree ops.
762 __mem_cgroup_insert_exceeded(memcg
, mz
, mctz
, excess
);
763 spin_unlock(&mctz
->lock
);
768 static void mem_cgroup_remove_from_trees(struct mem_cgroup
*memcg
)
771 struct mem_cgroup_per_zone
*mz
;
772 struct mem_cgroup_tree_per_zone
*mctz
;
774 for_each_node(node
) {
775 for (zone
= 0; zone
< MAX_NR_ZONES
; zone
++) {
776 mz
= mem_cgroup_zoneinfo(memcg
, node
, zone
);
777 mctz
= soft_limit_tree_node_zone(node
, zone
);
778 mem_cgroup_remove_exceeded(memcg
, mz
, mctz
);
783 static struct mem_cgroup_per_zone
*
784 __mem_cgroup_largest_soft_limit_node(struct mem_cgroup_tree_per_zone
*mctz
)
786 struct rb_node
*rightmost
= NULL
;
787 struct mem_cgroup_per_zone
*mz
;
791 rightmost
= rb_last(&mctz
->rb_root
);
793 goto done
; /* Nothing to reclaim from */
795 mz
= rb_entry(rightmost
, struct mem_cgroup_per_zone
, tree_node
);
797 * Remove the node now but someone else can add it back,
798 * we will to add it back at the end of reclaim to its correct
799 * position in the tree.
801 __mem_cgroup_remove_exceeded(mz
->memcg
, mz
, mctz
);
802 if (!res_counter_soft_limit_excess(&mz
->memcg
->res
) ||
803 !css_tryget(&mz
->memcg
->css
))
809 static struct mem_cgroup_per_zone
*
810 mem_cgroup_largest_soft_limit_node(struct mem_cgroup_tree_per_zone
*mctz
)
812 struct mem_cgroup_per_zone
*mz
;
814 spin_lock(&mctz
->lock
);
815 mz
= __mem_cgroup_largest_soft_limit_node(mctz
);
816 spin_unlock(&mctz
->lock
);
821 * Implementation Note: reading percpu statistics for memcg.
823 * Both of vmstat[] and percpu_counter has threshold and do periodic
824 * synchronization to implement "quick" read. There are trade-off between
825 * reading cost and precision of value. Then, we may have a chance to implement
826 * a periodic synchronizion of counter in memcg's counter.
828 * But this _read() function is used for user interface now. The user accounts
829 * memory usage by memory cgroup and he _always_ requires exact value because
830 * he accounts memory. Even if we provide quick-and-fuzzy read, we always
831 * have to visit all online cpus and make sum. So, for now, unnecessary
832 * synchronization is not implemented. (just implemented for cpu hotplug)
834 * If there are kernel internal actions which can make use of some not-exact
835 * value, and reading all cpu value can be performance bottleneck in some
836 * common workload, threashold and synchonization as vmstat[] should be
839 static long mem_cgroup_read_stat(struct mem_cgroup
*memcg
,
840 enum mem_cgroup_stat_index idx
)
846 for_each_online_cpu(cpu
)
847 val
+= per_cpu(memcg
->stat
->count
[idx
], cpu
);
848 #ifdef CONFIG_HOTPLUG_CPU
849 spin_lock(&memcg
->pcp_counter_lock
);
850 val
+= memcg
->nocpu_base
.count
[idx
];
851 spin_unlock(&memcg
->pcp_counter_lock
);
857 static void mem_cgroup_swap_statistics(struct mem_cgroup
*memcg
,
860 int val
= (charge
) ? 1 : -1;
861 this_cpu_add(memcg
->stat
->count
[MEM_CGROUP_STAT_SWAP
], val
);
864 static unsigned long mem_cgroup_read_events(struct mem_cgroup
*memcg
,
865 enum mem_cgroup_events_index idx
)
867 unsigned long val
= 0;
871 for_each_online_cpu(cpu
)
872 val
+= per_cpu(memcg
->stat
->events
[idx
], cpu
);
873 #ifdef CONFIG_HOTPLUG_CPU
874 spin_lock(&memcg
->pcp_counter_lock
);
875 val
+= memcg
->nocpu_base
.events
[idx
];
876 spin_unlock(&memcg
->pcp_counter_lock
);
882 static void mem_cgroup_charge_statistics(struct mem_cgroup
*memcg
,
884 bool anon
, int nr_pages
)
889 * Here, RSS means 'mapped anon' and anon's SwapCache. Shmem/tmpfs is
890 * counted as CACHE even if it's on ANON LRU.
893 __this_cpu_add(memcg
->stat
->count
[MEM_CGROUP_STAT_RSS
],
896 __this_cpu_add(memcg
->stat
->count
[MEM_CGROUP_STAT_CACHE
],
899 if (PageTransHuge(page
))
900 __this_cpu_add(memcg
->stat
->count
[MEM_CGROUP_STAT_RSS_HUGE
],
903 /* pagein of a big page is an event. So, ignore page size */
905 __this_cpu_inc(memcg
->stat
->events
[MEM_CGROUP_EVENTS_PGPGIN
]);
907 __this_cpu_inc(memcg
->stat
->events
[MEM_CGROUP_EVENTS_PGPGOUT
]);
908 nr_pages
= -nr_pages
; /* for event */
911 __this_cpu_add(memcg
->stat
->nr_page_events
, nr_pages
);
917 mem_cgroup_get_lru_size(struct lruvec
*lruvec
, enum lru_list lru
)
919 struct mem_cgroup_per_zone
*mz
;
921 mz
= container_of(lruvec
, struct mem_cgroup_per_zone
, lruvec
);
922 return mz
->lru_size
[lru
];
926 mem_cgroup_zone_nr_lru_pages(struct mem_cgroup
*memcg
, int nid
, int zid
,
927 unsigned int lru_mask
)
929 struct mem_cgroup_per_zone
*mz
;
931 unsigned long ret
= 0;
933 mz
= mem_cgroup_zoneinfo(memcg
, nid
, zid
);
936 if (BIT(lru
) & lru_mask
)
937 ret
+= mz
->lru_size
[lru
];
943 mem_cgroup_node_nr_lru_pages(struct mem_cgroup
*memcg
,
944 int nid
, unsigned int lru_mask
)
949 for (zid
= 0; zid
< MAX_NR_ZONES
; zid
++)
950 total
+= mem_cgroup_zone_nr_lru_pages(memcg
,
956 static unsigned long mem_cgroup_nr_lru_pages(struct mem_cgroup
*memcg
,
957 unsigned int lru_mask
)
962 for_each_node_state(nid
, N_MEMORY
)
963 total
+= mem_cgroup_node_nr_lru_pages(memcg
, nid
, lru_mask
);
967 static bool mem_cgroup_event_ratelimit(struct mem_cgroup
*memcg
,
968 enum mem_cgroup_events_target target
)
970 unsigned long val
, next
;
972 val
= __this_cpu_read(memcg
->stat
->nr_page_events
);
973 next
= __this_cpu_read(memcg
->stat
->targets
[target
]);
974 /* from time_after() in jiffies.h */
975 if ((long)next
- (long)val
< 0) {
977 case MEM_CGROUP_TARGET_THRESH
:
978 next
= val
+ THRESHOLDS_EVENTS_TARGET
;
980 case MEM_CGROUP_TARGET_SOFTLIMIT
:
981 next
= val
+ SOFTLIMIT_EVENTS_TARGET
;
983 case MEM_CGROUP_TARGET_NUMAINFO
:
984 next
= val
+ NUMAINFO_EVENTS_TARGET
;
989 __this_cpu_write(memcg
->stat
->targets
[target
], next
);
996 * Check events in order.
999 static void memcg_check_events(struct mem_cgroup
*memcg
, struct page
*page
)
1002 /* threshold event is triggered in finer grain than soft limit */
1003 if (unlikely(mem_cgroup_event_ratelimit(memcg
,
1004 MEM_CGROUP_TARGET_THRESH
))) {
1006 bool do_numainfo __maybe_unused
;
1008 do_softlimit
= mem_cgroup_event_ratelimit(memcg
,
1009 MEM_CGROUP_TARGET_SOFTLIMIT
);
1010 #if MAX_NUMNODES > 1
1011 do_numainfo
= mem_cgroup_event_ratelimit(memcg
,
1012 MEM_CGROUP_TARGET_NUMAINFO
);
1016 mem_cgroup_threshold(memcg
);
1017 if (unlikely(do_softlimit
))
1018 mem_cgroup_update_tree(memcg
, page
);
1019 #if MAX_NUMNODES > 1
1020 if (unlikely(do_numainfo
))
1021 atomic_inc(&memcg
->numainfo_events
);
1027 struct mem_cgroup
*mem_cgroup_from_task(struct task_struct
*p
)
1030 * mm_update_next_owner() may clear mm->owner to NULL
1031 * if it races with swapoff, page migration, etc.
1032 * So this can be called with p == NULL.
1037 return mem_cgroup_from_css(task_css(p
, mem_cgroup_subsys_id
));
1040 struct mem_cgroup
*try_get_mem_cgroup_from_mm(struct mm_struct
*mm
)
1042 struct mem_cgroup
*memcg
= NULL
;
1047 * Because we have no locks, mm->owner's may be being moved to other
1048 * cgroup. We use css_tryget() here even if this looks
1049 * pessimistic (rather than adding locks here).
1053 memcg
= mem_cgroup_from_task(rcu_dereference(mm
->owner
));
1054 if (unlikely(!memcg
))
1056 } while (!css_tryget(&memcg
->css
));
1062 * Returns a next (in a pre-order walk) alive memcg (with elevated css
1063 * ref. count) or NULL if the whole root's subtree has been visited.
1065 * helper function to be used by mem_cgroup_iter
1067 static struct mem_cgroup
*__mem_cgroup_iter_next(struct mem_cgroup
*root
,
1068 struct mem_cgroup
*last_visited
)
1070 struct cgroup_subsys_state
*prev_css
, *next_css
;
1072 prev_css
= last_visited
? &last_visited
->css
: NULL
;
1074 next_css
= css_next_descendant_pre(prev_css
, &root
->css
);
1077 * Even if we found a group we have to make sure it is
1078 * alive. css && !memcg means that the groups should be
1079 * skipped and we should continue the tree walk.
1080 * last_visited css is safe to use because it is
1081 * protected by css_get and the tree walk is rcu safe.
1084 struct mem_cgroup
*mem
= mem_cgroup_from_css(next_css
);
1086 if (css_tryget(&mem
->css
))
1089 prev_css
= next_css
;
1097 static void mem_cgroup_iter_invalidate(struct mem_cgroup
*root
)
1100 * When a group in the hierarchy below root is destroyed, the
1101 * hierarchy iterator can no longer be trusted since it might
1102 * have pointed to the destroyed group. Invalidate it.
1104 atomic_inc(&root
->dead_count
);
1107 static struct mem_cgroup
*
1108 mem_cgroup_iter_load(struct mem_cgroup_reclaim_iter
*iter
,
1109 struct mem_cgroup
*root
,
1112 struct mem_cgroup
*position
= NULL
;
1114 * A cgroup destruction happens in two stages: offlining and
1115 * release. They are separated by a RCU grace period.
1117 * If the iterator is valid, we may still race with an
1118 * offlining. The RCU lock ensures the object won't be
1119 * released, tryget will fail if we lost the race.
1121 *sequence
= atomic_read(&root
->dead_count
);
1122 if (iter
->last_dead_count
== *sequence
) {
1124 position
= iter
->last_visited
;
1125 if (position
&& !css_tryget(&position
->css
))
1131 static void mem_cgroup_iter_update(struct mem_cgroup_reclaim_iter
*iter
,
1132 struct mem_cgroup
*last_visited
,
1133 struct mem_cgroup
*new_position
,
1137 css_put(&last_visited
->css
);
1139 * We store the sequence count from the time @last_visited was
1140 * loaded successfully instead of rereading it here so that we
1141 * don't lose destruction events in between. We could have
1142 * raced with the destruction of @new_position after all.
1144 iter
->last_visited
= new_position
;
1146 iter
->last_dead_count
= sequence
;
1150 * mem_cgroup_iter - iterate over memory cgroup hierarchy
1151 * @root: hierarchy root
1152 * @prev: previously returned memcg, NULL on first invocation
1153 * @reclaim: cookie for shared reclaim walks, NULL for full walks
1155 * Returns references to children of the hierarchy below @root, or
1156 * @root itself, or %NULL after a full round-trip.
1158 * Caller must pass the return value in @prev on subsequent
1159 * invocations for reference counting, or use mem_cgroup_iter_break()
1160 * to cancel a hierarchy walk before the round-trip is complete.
1162 * Reclaimers can specify a zone and a priority level in @reclaim to
1163 * divide up the memcgs in the hierarchy among all concurrent
1164 * reclaimers operating on the same zone and priority.
1166 struct mem_cgroup
*mem_cgroup_iter(struct mem_cgroup
*root
,
1167 struct mem_cgroup
*prev
,
1168 struct mem_cgroup_reclaim_cookie
*reclaim
)
1170 struct mem_cgroup
*memcg
= NULL
;
1171 struct mem_cgroup
*last_visited
= NULL
;
1173 if (mem_cgroup_disabled())
1177 root
= root_mem_cgroup
;
1179 if (prev
&& !reclaim
)
1180 last_visited
= prev
;
1182 if (!root
->use_hierarchy
&& root
!= root_mem_cgroup
) {
1190 struct mem_cgroup_reclaim_iter
*uninitialized_var(iter
);
1191 int uninitialized_var(seq
);
1194 int nid
= zone_to_nid(reclaim
->zone
);
1195 int zid
= zone_idx(reclaim
->zone
);
1196 struct mem_cgroup_per_zone
*mz
;
1198 mz
= mem_cgroup_zoneinfo(root
, nid
, zid
);
1199 iter
= &mz
->reclaim_iter
[reclaim
->priority
];
1200 if (prev
&& reclaim
->generation
!= iter
->generation
) {
1201 iter
->last_visited
= NULL
;
1205 last_visited
= mem_cgroup_iter_load(iter
, root
, &seq
);
1208 memcg
= __mem_cgroup_iter_next(root
, last_visited
);
1211 mem_cgroup_iter_update(iter
, last_visited
, memcg
, seq
);
1215 else if (!prev
&& memcg
)
1216 reclaim
->generation
= iter
->generation
;
1225 if (prev
&& prev
!= root
)
1226 css_put(&prev
->css
);
1232 * mem_cgroup_iter_break - abort a hierarchy walk prematurely
1233 * @root: hierarchy root
1234 * @prev: last visited hierarchy member as returned by mem_cgroup_iter()
1236 void mem_cgroup_iter_break(struct mem_cgroup
*root
,
1237 struct mem_cgroup
*prev
)
1240 root
= root_mem_cgroup
;
1241 if (prev
&& prev
!= root
)
1242 css_put(&prev
->css
);
1246 * Iteration constructs for visiting all cgroups (under a tree). If
1247 * loops are exited prematurely (break), mem_cgroup_iter_break() must
1248 * be used for reference counting.
1250 #define for_each_mem_cgroup_tree(iter, root) \
1251 for (iter = mem_cgroup_iter(root, NULL, NULL); \
1253 iter = mem_cgroup_iter(root, iter, NULL))
1255 #define for_each_mem_cgroup(iter) \
1256 for (iter = mem_cgroup_iter(NULL, NULL, NULL); \
1258 iter = mem_cgroup_iter(NULL, iter, NULL))
1260 void __mem_cgroup_count_vm_event(struct mm_struct
*mm
, enum vm_event_item idx
)
1262 struct mem_cgroup
*memcg
;
1265 memcg
= mem_cgroup_from_task(rcu_dereference(mm
->owner
));
1266 if (unlikely(!memcg
))
1271 this_cpu_inc(memcg
->stat
->events
[MEM_CGROUP_EVENTS_PGFAULT
]);
1274 this_cpu_inc(memcg
->stat
->events
[MEM_CGROUP_EVENTS_PGMAJFAULT
]);
1282 EXPORT_SYMBOL(__mem_cgroup_count_vm_event
);
1285 * mem_cgroup_zone_lruvec - get the lru list vector for a zone and memcg
1286 * @zone: zone of the wanted lruvec
1287 * @memcg: memcg of the wanted lruvec
1289 * Returns the lru list vector holding pages for the given @zone and
1290 * @mem. This can be the global zone lruvec, if the memory controller
1293 struct lruvec
*mem_cgroup_zone_lruvec(struct zone
*zone
,
1294 struct mem_cgroup
*memcg
)
1296 struct mem_cgroup_per_zone
*mz
;
1297 struct lruvec
*lruvec
;
1299 if (mem_cgroup_disabled()) {
1300 lruvec
= &zone
->lruvec
;
1304 mz
= mem_cgroup_zoneinfo(memcg
, zone_to_nid(zone
), zone_idx(zone
));
1305 lruvec
= &mz
->lruvec
;
1308 * Since a node can be onlined after the mem_cgroup was created,
1309 * we have to be prepared to initialize lruvec->zone here;
1310 * and if offlined then reonlined, we need to reinitialize it.
1312 if (unlikely(lruvec
->zone
!= zone
))
1313 lruvec
->zone
= zone
;
1318 * Following LRU functions are allowed to be used without PCG_LOCK.
1319 * Operations are called by routine of global LRU independently from memcg.
1320 * What we have to take care of here is validness of pc->mem_cgroup.
1322 * Changes to pc->mem_cgroup happens when
1325 * In typical case, "charge" is done before add-to-lru. Exception is SwapCache.
1326 * It is added to LRU before charge.
1327 * If PCG_USED bit is not set, page_cgroup is not added to this private LRU.
1328 * When moving account, the page is not on LRU. It's isolated.
1332 * mem_cgroup_page_lruvec - return lruvec for adding an lru page
1334 * @zone: zone of the page
1336 struct lruvec
*mem_cgroup_page_lruvec(struct page
*page
, struct zone
*zone
)
1338 struct mem_cgroup_per_zone
*mz
;
1339 struct mem_cgroup
*memcg
;
1340 struct page_cgroup
*pc
;
1341 struct lruvec
*lruvec
;
1343 if (mem_cgroup_disabled()) {
1344 lruvec
= &zone
->lruvec
;
1348 pc
= lookup_page_cgroup(page
);
1349 memcg
= pc
->mem_cgroup
;
1352 * Surreptitiously switch any uncharged offlist page to root:
1353 * an uncharged page off lru does nothing to secure
1354 * its former mem_cgroup from sudden removal.
1356 * Our caller holds lru_lock, and PageCgroupUsed is updated
1357 * under page_cgroup lock: between them, they make all uses
1358 * of pc->mem_cgroup safe.
1360 if (!PageLRU(page
) && !PageCgroupUsed(pc
) && memcg
!= root_mem_cgroup
)
1361 pc
->mem_cgroup
= memcg
= root_mem_cgroup
;
1363 mz
= page_cgroup_zoneinfo(memcg
, page
);
1364 lruvec
= &mz
->lruvec
;
1367 * Since a node can be onlined after the mem_cgroup was created,
1368 * we have to be prepared to initialize lruvec->zone here;
1369 * and if offlined then reonlined, we need to reinitialize it.
1371 if (unlikely(lruvec
->zone
!= zone
))
1372 lruvec
->zone
= zone
;
1377 * mem_cgroup_update_lru_size - account for adding or removing an lru page
1378 * @lruvec: mem_cgroup per zone lru vector
1379 * @lru: index of lru list the page is sitting on
1380 * @nr_pages: positive when adding or negative when removing
1382 * This function must be called when a page is added to or removed from an
1385 void mem_cgroup_update_lru_size(struct lruvec
*lruvec
, enum lru_list lru
,
1388 struct mem_cgroup_per_zone
*mz
;
1389 unsigned long *lru_size
;
1391 if (mem_cgroup_disabled())
1394 mz
= container_of(lruvec
, struct mem_cgroup_per_zone
, lruvec
);
1395 lru_size
= mz
->lru_size
+ lru
;
1396 *lru_size
+= nr_pages
;
1397 VM_BUG_ON((long)(*lru_size
) < 0);
1401 * Checks whether given mem is same or in the root_mem_cgroup's
1404 bool __mem_cgroup_same_or_subtree(const struct mem_cgroup
*root_memcg
,
1405 struct mem_cgroup
*memcg
)
1407 if (root_memcg
== memcg
)
1409 if (!root_memcg
->use_hierarchy
|| !memcg
)
1411 return css_is_ancestor(&memcg
->css
, &root_memcg
->css
);
1414 static bool mem_cgroup_same_or_subtree(const struct mem_cgroup
*root_memcg
,
1415 struct mem_cgroup
*memcg
)
1420 ret
= __mem_cgroup_same_or_subtree(root_memcg
, memcg
);
1425 bool task_in_mem_cgroup(struct task_struct
*task
,
1426 const struct mem_cgroup
*memcg
)
1428 struct mem_cgroup
*curr
= NULL
;
1429 struct task_struct
*p
;
1432 p
= find_lock_task_mm(task
);
1434 curr
= try_get_mem_cgroup_from_mm(p
->mm
);
1438 * All threads may have already detached their mm's, but the oom
1439 * killer still needs to detect if they have already been oom
1440 * killed to prevent needlessly killing additional tasks.
1443 curr
= mem_cgroup_from_task(task
);
1445 css_get(&curr
->css
);
1451 * We should check use_hierarchy of "memcg" not "curr". Because checking
1452 * use_hierarchy of "curr" here make this function true if hierarchy is
1453 * enabled in "curr" and "curr" is a child of "memcg" in *cgroup*
1454 * hierarchy(even if use_hierarchy is disabled in "memcg").
1456 ret
= mem_cgroup_same_or_subtree(memcg
, curr
);
1457 css_put(&curr
->css
);
1461 int mem_cgroup_inactive_anon_is_low(struct lruvec
*lruvec
)
1463 unsigned long inactive_ratio
;
1464 unsigned long inactive
;
1465 unsigned long active
;
1468 inactive
= mem_cgroup_get_lru_size(lruvec
, LRU_INACTIVE_ANON
);
1469 active
= mem_cgroup_get_lru_size(lruvec
, LRU_ACTIVE_ANON
);
1471 gb
= (inactive
+ active
) >> (30 - PAGE_SHIFT
);
1473 inactive_ratio
= int_sqrt(10 * gb
);
1477 return inactive
* inactive_ratio
< active
;
1480 #define mem_cgroup_from_res_counter(counter, member) \
1481 container_of(counter, struct mem_cgroup, member)
1484 * mem_cgroup_margin - calculate chargeable space of a memory cgroup
1485 * @memcg: the memory cgroup
1487 * Returns the maximum amount of memory @mem can be charged with, in
1490 static unsigned long mem_cgroup_margin(struct mem_cgroup
*memcg
)
1492 unsigned long long margin
;
1494 margin
= res_counter_margin(&memcg
->res
);
1495 if (do_swap_account
)
1496 margin
= min(margin
, res_counter_margin(&memcg
->memsw
));
1497 return margin
>> PAGE_SHIFT
;
1500 int mem_cgroup_swappiness(struct mem_cgroup
*memcg
)
1503 if (!css_parent(&memcg
->css
))
1504 return vm_swappiness
;
1506 return memcg
->swappiness
;
1510 * memcg->moving_account is used for checking possibility that some thread is
1511 * calling move_account(). When a thread on CPU-A starts moving pages under
1512 * a memcg, other threads should check memcg->moving_account under
1513 * rcu_read_lock(), like this:
1517 * memcg->moving_account+1 if (memcg->mocing_account)
1519 * synchronize_rcu() update something.
1524 /* for quick checking without looking up memcg */
1525 atomic_t memcg_moving __read_mostly
;
1527 static void mem_cgroup_start_move(struct mem_cgroup
*memcg
)
1529 atomic_inc(&memcg_moving
);
1530 atomic_inc(&memcg
->moving_account
);
1534 static void mem_cgroup_end_move(struct mem_cgroup
*memcg
)
1537 * Now, mem_cgroup_clear_mc() may call this function with NULL.
1538 * We check NULL in callee rather than caller.
1541 atomic_dec(&memcg_moving
);
1542 atomic_dec(&memcg
->moving_account
);
1547 * 2 routines for checking "mem" is under move_account() or not.
1549 * mem_cgroup_stolen() - checking whether a cgroup is mc.from or not. This
1550 * is used for avoiding races in accounting. If true,
1551 * pc->mem_cgroup may be overwritten.
1553 * mem_cgroup_under_move() - checking a cgroup is mc.from or mc.to or
1554 * under hierarchy of moving cgroups. This is for
1555 * waiting at hith-memory prressure caused by "move".
1558 static bool mem_cgroup_stolen(struct mem_cgroup
*memcg
)
1560 VM_BUG_ON(!rcu_read_lock_held());
1561 return atomic_read(&memcg
->moving_account
) > 0;
1564 static bool mem_cgroup_under_move(struct mem_cgroup
*memcg
)
1566 struct mem_cgroup
*from
;
1567 struct mem_cgroup
*to
;
1570 * Unlike task_move routines, we access mc.to, mc.from not under
1571 * mutual exclusion by cgroup_mutex. Here, we take spinlock instead.
1573 spin_lock(&mc
.lock
);
1579 ret
= mem_cgroup_same_or_subtree(memcg
, from
)
1580 || mem_cgroup_same_or_subtree(memcg
, to
);
1582 spin_unlock(&mc
.lock
);
1586 static bool mem_cgroup_wait_acct_move(struct mem_cgroup
*memcg
)
1588 if (mc
.moving_task
&& current
!= mc
.moving_task
) {
1589 if (mem_cgroup_under_move(memcg
)) {
1591 prepare_to_wait(&mc
.waitq
, &wait
, TASK_INTERRUPTIBLE
);
1592 /* moving charge context might have finished. */
1595 finish_wait(&mc
.waitq
, &wait
);
1603 * Take this lock when
1604 * - a code tries to modify page's memcg while it's USED.
1605 * - a code tries to modify page state accounting in a memcg.
1606 * see mem_cgroup_stolen(), too.
1608 static void move_lock_mem_cgroup(struct mem_cgroup
*memcg
,
1609 unsigned long *flags
)
1611 spin_lock_irqsave(&memcg
->move_lock
, *flags
);
1614 static void move_unlock_mem_cgroup(struct mem_cgroup
*memcg
,
1615 unsigned long *flags
)
1617 spin_unlock_irqrestore(&memcg
->move_lock
, *flags
);
1620 #define K(x) ((x) << (PAGE_SHIFT-10))
1622 * mem_cgroup_print_oom_info: Print OOM information relevant to memory controller.
1623 * @memcg: The memory cgroup that went over limit
1624 * @p: Task that is going to be killed
1626 * NOTE: @memcg and @p's mem_cgroup can be different when hierarchy is
1629 void mem_cgroup_print_oom_info(struct mem_cgroup
*memcg
, struct task_struct
*p
)
1631 struct cgroup
*task_cgrp
;
1632 struct cgroup
*mem_cgrp
;
1634 * Need a buffer in BSS, can't rely on allocations. The code relies
1635 * on the assumption that OOM is serialized for memory controller.
1636 * If this assumption is broken, revisit this code.
1638 static char memcg_name
[PATH_MAX
];
1640 struct mem_cgroup
*iter
;
1648 mem_cgrp
= memcg
->css
.cgroup
;
1649 task_cgrp
= task_cgroup(p
, mem_cgroup_subsys_id
);
1651 ret
= cgroup_path(task_cgrp
, memcg_name
, PATH_MAX
);
1654 * Unfortunately, we are unable to convert to a useful name
1655 * But we'll still print out the usage information
1662 pr_info("Task in %s killed", memcg_name
);
1665 ret
= cgroup_path(mem_cgrp
, memcg_name
, PATH_MAX
);
1673 * Continues from above, so we don't need an KERN_ level
1675 pr_cont(" as a result of limit of %s\n", memcg_name
);
1678 pr_info("memory: usage %llukB, limit %llukB, failcnt %llu\n",
1679 res_counter_read_u64(&memcg
->res
, RES_USAGE
) >> 10,
1680 res_counter_read_u64(&memcg
->res
, RES_LIMIT
) >> 10,
1681 res_counter_read_u64(&memcg
->res
, RES_FAILCNT
));
1682 pr_info("memory+swap: usage %llukB, limit %llukB, failcnt %llu\n",
1683 res_counter_read_u64(&memcg
->memsw
, RES_USAGE
) >> 10,
1684 res_counter_read_u64(&memcg
->memsw
, RES_LIMIT
) >> 10,
1685 res_counter_read_u64(&memcg
->memsw
, RES_FAILCNT
));
1686 pr_info("kmem: usage %llukB, limit %llukB, failcnt %llu\n",
1687 res_counter_read_u64(&memcg
->kmem
, RES_USAGE
) >> 10,
1688 res_counter_read_u64(&memcg
->kmem
, RES_LIMIT
) >> 10,
1689 res_counter_read_u64(&memcg
->kmem
, RES_FAILCNT
));
1691 for_each_mem_cgroup_tree(iter
, memcg
) {
1692 pr_info("Memory cgroup stats");
1695 ret
= cgroup_path(iter
->css
.cgroup
, memcg_name
, PATH_MAX
);
1697 pr_cont(" for %s", memcg_name
);
1701 for (i
= 0; i
< MEM_CGROUP_STAT_NSTATS
; i
++) {
1702 if (i
== MEM_CGROUP_STAT_SWAP
&& !do_swap_account
)
1704 pr_cont(" %s:%ldKB", mem_cgroup_stat_names
[i
],
1705 K(mem_cgroup_read_stat(iter
, i
)));
1708 for (i
= 0; i
< NR_LRU_LISTS
; i
++)
1709 pr_cont(" %s:%luKB", mem_cgroup_lru_names
[i
],
1710 K(mem_cgroup_nr_lru_pages(iter
, BIT(i
))));
1717 * This function returns the number of memcg under hierarchy tree. Returns
1718 * 1(self count) if no children.
1720 static int mem_cgroup_count_children(struct mem_cgroup
*memcg
)
1723 struct mem_cgroup
*iter
;
1725 for_each_mem_cgroup_tree(iter
, memcg
)
1731 * Return the memory (and swap, if configured) limit for a memcg.
1733 static u64
mem_cgroup_get_limit(struct mem_cgroup
*memcg
)
1737 limit
= res_counter_read_u64(&memcg
->res
, RES_LIMIT
);
1740 * Do not consider swap space if we cannot swap due to swappiness
1742 if (mem_cgroup_swappiness(memcg
)) {
1745 limit
+= total_swap_pages
<< PAGE_SHIFT
;
1746 memsw
= res_counter_read_u64(&memcg
->memsw
, RES_LIMIT
);
1749 * If memsw is finite and limits the amount of swap space
1750 * available to this memcg, return that limit.
1752 limit
= min(limit
, memsw
);
1758 static void mem_cgroup_out_of_memory(struct mem_cgroup
*memcg
, gfp_t gfp_mask
,
1761 struct mem_cgroup
*iter
;
1762 unsigned long chosen_points
= 0;
1763 unsigned long totalpages
;
1764 unsigned int points
= 0;
1765 struct task_struct
*chosen
= NULL
;
1768 * If current has a pending SIGKILL or is exiting, then automatically
1769 * select it. The goal is to allow it to allocate so that it may
1770 * quickly exit and free its memory.
1772 if (fatal_signal_pending(current
) || current
->flags
& PF_EXITING
) {
1773 set_thread_flag(TIF_MEMDIE
);
1777 check_panic_on_oom(CONSTRAINT_MEMCG
, gfp_mask
, order
, NULL
);
1778 totalpages
= mem_cgroup_get_limit(memcg
) >> PAGE_SHIFT
? : 1;
1779 for_each_mem_cgroup_tree(iter
, memcg
) {
1780 struct css_task_iter it
;
1781 struct task_struct
*task
;
1783 css_task_iter_start(&iter
->css
, &it
);
1784 while ((task
= css_task_iter_next(&it
))) {
1785 switch (oom_scan_process_thread(task
, totalpages
, NULL
,
1787 case OOM_SCAN_SELECT
:
1789 put_task_struct(chosen
);
1791 chosen_points
= ULONG_MAX
;
1792 get_task_struct(chosen
);
1794 case OOM_SCAN_CONTINUE
:
1796 case OOM_SCAN_ABORT
:
1797 css_task_iter_end(&it
);
1798 mem_cgroup_iter_break(memcg
, iter
);
1800 put_task_struct(chosen
);
1805 points
= oom_badness(task
, memcg
, NULL
, totalpages
);
1806 if (points
> chosen_points
) {
1808 put_task_struct(chosen
);
1810 chosen_points
= points
;
1811 get_task_struct(chosen
);
1814 css_task_iter_end(&it
);
1819 points
= chosen_points
* 1000 / totalpages
;
1820 oom_kill_process(chosen
, gfp_mask
, order
, points
, totalpages
, memcg
,
1821 NULL
, "Memory cgroup out of memory");
1824 static unsigned long mem_cgroup_reclaim(struct mem_cgroup
*memcg
,
1826 unsigned long flags
)
1828 unsigned long total
= 0;
1829 bool noswap
= false;
1832 if (flags
& MEM_CGROUP_RECLAIM_NOSWAP
)
1834 if (!(flags
& MEM_CGROUP_RECLAIM_SHRINK
) && memcg
->memsw_is_minimum
)
1837 for (loop
= 0; loop
< MEM_CGROUP_MAX_RECLAIM_LOOPS
; loop
++) {
1839 drain_all_stock_async(memcg
);
1840 total
+= try_to_free_mem_cgroup_pages(memcg
, gfp_mask
, noswap
);
1842 * Allow limit shrinkers, which are triggered directly
1843 * by userspace, to catch signals and stop reclaim
1844 * after minimal progress, regardless of the margin.
1846 if (total
&& (flags
& MEM_CGROUP_RECLAIM_SHRINK
))
1848 if (mem_cgroup_margin(memcg
))
1851 * If nothing was reclaimed after two attempts, there
1852 * may be no reclaimable pages in this hierarchy.
1861 * test_mem_cgroup_node_reclaimable
1862 * @memcg: the target memcg
1863 * @nid: the node ID to be checked.
1864 * @noswap : specify true here if the user wants flle only information.
1866 * This function returns whether the specified memcg contains any
1867 * reclaimable pages on a node. Returns true if there are any reclaimable
1868 * pages in the node.
1870 static bool test_mem_cgroup_node_reclaimable(struct mem_cgroup
*memcg
,
1871 int nid
, bool noswap
)
1873 if (mem_cgroup_node_nr_lru_pages(memcg
, nid
, LRU_ALL_FILE
))
1875 if (noswap
|| !total_swap_pages
)
1877 if (mem_cgroup_node_nr_lru_pages(memcg
, nid
, LRU_ALL_ANON
))
1882 #if MAX_NUMNODES > 1
1885 * Always updating the nodemask is not very good - even if we have an empty
1886 * list or the wrong list here, we can start from some node and traverse all
1887 * nodes based on the zonelist. So update the list loosely once per 10 secs.
1890 static void mem_cgroup_may_update_nodemask(struct mem_cgroup
*memcg
)
1894 * numainfo_events > 0 means there was at least NUMAINFO_EVENTS_TARGET
1895 * pagein/pageout changes since the last update.
1897 if (!atomic_read(&memcg
->numainfo_events
))
1899 if (atomic_inc_return(&memcg
->numainfo_updating
) > 1)
1902 /* make a nodemask where this memcg uses memory from */
1903 memcg
->scan_nodes
= node_states
[N_MEMORY
];
1905 for_each_node_mask(nid
, node_states
[N_MEMORY
]) {
1907 if (!test_mem_cgroup_node_reclaimable(memcg
, nid
, false))
1908 node_clear(nid
, memcg
->scan_nodes
);
1911 atomic_set(&memcg
->numainfo_events
, 0);
1912 atomic_set(&memcg
->numainfo_updating
, 0);
1916 * Selecting a node where we start reclaim from. Because what we need is just
1917 * reducing usage counter, start from anywhere is O,K. Considering
1918 * memory reclaim from current node, there are pros. and cons.
1920 * Freeing memory from current node means freeing memory from a node which
1921 * we'll use or we've used. So, it may make LRU bad. And if several threads
1922 * hit limits, it will see a contention on a node. But freeing from remote
1923 * node means more costs for memory reclaim because of memory latency.
1925 * Now, we use round-robin. Better algorithm is welcomed.
1927 int mem_cgroup_select_victim_node(struct mem_cgroup
*memcg
)
1931 mem_cgroup_may_update_nodemask(memcg
);
1932 node
= memcg
->last_scanned_node
;
1934 node
= next_node(node
, memcg
->scan_nodes
);
1935 if (node
== MAX_NUMNODES
)
1936 node
= first_node(memcg
->scan_nodes
);
1938 * We call this when we hit limit, not when pages are added to LRU.
1939 * No LRU may hold pages because all pages are UNEVICTABLE or
1940 * memcg is too small and all pages are not on LRU. In that case,
1941 * we use curret node.
1943 if (unlikely(node
== MAX_NUMNODES
))
1944 node
= numa_node_id();
1946 memcg
->last_scanned_node
= node
;
1951 * Check all nodes whether it contains reclaimable pages or not.
1952 * For quick scan, we make use of scan_nodes. This will allow us to skip
1953 * unused nodes. But scan_nodes is lazily updated and may not cotain
1954 * enough new information. We need to do double check.
1956 static bool mem_cgroup_reclaimable(struct mem_cgroup
*memcg
, bool noswap
)
1961 * quick check...making use of scan_node.
1962 * We can skip unused nodes.
1964 if (!nodes_empty(memcg
->scan_nodes
)) {
1965 for (nid
= first_node(memcg
->scan_nodes
);
1967 nid
= next_node(nid
, memcg
->scan_nodes
)) {
1969 if (test_mem_cgroup_node_reclaimable(memcg
, nid
, noswap
))
1974 * Check rest of nodes.
1976 for_each_node_state(nid
, N_MEMORY
) {
1977 if (node_isset(nid
, memcg
->scan_nodes
))
1979 if (test_mem_cgroup_node_reclaimable(memcg
, nid
, noswap
))
1986 int mem_cgroup_select_victim_node(struct mem_cgroup
*memcg
)
1991 static bool mem_cgroup_reclaimable(struct mem_cgroup
*memcg
, bool noswap
)
1993 return test_mem_cgroup_node_reclaimable(memcg
, 0, noswap
);
1997 static int mem_cgroup_soft_reclaim(struct mem_cgroup
*root_memcg
,
2000 unsigned long *total_scanned
)
2002 struct mem_cgroup
*victim
= NULL
;
2005 unsigned long excess
;
2006 unsigned long nr_scanned
;
2007 struct mem_cgroup_reclaim_cookie reclaim
= {
2012 excess
= res_counter_soft_limit_excess(&root_memcg
->res
) >> PAGE_SHIFT
;
2015 victim
= mem_cgroup_iter(root_memcg
, victim
, &reclaim
);
2020 * If we have not been able to reclaim
2021 * anything, it might because there are
2022 * no reclaimable pages under this hierarchy
2027 * We want to do more targeted reclaim.
2028 * excess >> 2 is not to excessive so as to
2029 * reclaim too much, nor too less that we keep
2030 * coming back to reclaim from this cgroup
2032 if (total
>= (excess
>> 2) ||
2033 (loop
> MEM_CGROUP_MAX_RECLAIM_LOOPS
))
2038 if (!mem_cgroup_reclaimable(victim
, false))
2040 total
+= mem_cgroup_shrink_node_zone(victim
, gfp_mask
, false,
2042 *total_scanned
+= nr_scanned
;
2043 if (!res_counter_soft_limit_excess(&root_memcg
->res
))
2046 mem_cgroup_iter_break(root_memcg
, victim
);
2050 #ifdef CONFIG_LOCKDEP
2051 static struct lockdep_map memcg_oom_lock_dep_map
= {
2052 .name
= "memcg_oom_lock",
2056 static DEFINE_SPINLOCK(memcg_oom_lock
);
2059 * Check OOM-Killer is already running under our hierarchy.
2060 * If someone is running, return false.
2062 static bool mem_cgroup_oom_trylock(struct mem_cgroup
*memcg
)
2064 struct mem_cgroup
*iter
, *failed
= NULL
;
2066 spin_lock(&memcg_oom_lock
);
2068 for_each_mem_cgroup_tree(iter
, memcg
) {
2069 if (iter
->oom_lock
) {
2071 * this subtree of our hierarchy is already locked
2072 * so we cannot give a lock.
2075 mem_cgroup_iter_break(memcg
, iter
);
2078 iter
->oom_lock
= true;
2083 * OK, we failed to lock the whole subtree so we have
2084 * to clean up what we set up to the failing subtree
2086 for_each_mem_cgroup_tree(iter
, memcg
) {
2087 if (iter
== failed
) {
2088 mem_cgroup_iter_break(memcg
, iter
);
2091 iter
->oom_lock
= false;
2094 mutex_acquire(&memcg_oom_lock_dep_map
, 0, 1, _RET_IP_
);
2096 spin_unlock(&memcg_oom_lock
);
2101 static void mem_cgroup_oom_unlock(struct mem_cgroup
*memcg
)
2103 struct mem_cgroup
*iter
;
2105 spin_lock(&memcg_oom_lock
);
2106 mutex_release(&memcg_oom_lock_dep_map
, 1, _RET_IP_
);
2107 for_each_mem_cgroup_tree(iter
, memcg
)
2108 iter
->oom_lock
= false;
2109 spin_unlock(&memcg_oom_lock
);
2112 static void mem_cgroup_mark_under_oom(struct mem_cgroup
*memcg
)
2114 struct mem_cgroup
*iter
;
2116 for_each_mem_cgroup_tree(iter
, memcg
)
2117 atomic_inc(&iter
->under_oom
);
2120 static void mem_cgroup_unmark_under_oom(struct mem_cgroup
*memcg
)
2122 struct mem_cgroup
*iter
;
2125 * When a new child is created while the hierarchy is under oom,
2126 * mem_cgroup_oom_lock() may not be called. We have to use
2127 * atomic_add_unless() here.
2129 for_each_mem_cgroup_tree(iter
, memcg
)
2130 atomic_add_unless(&iter
->under_oom
, -1, 0);
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 atomic_inc(&memcg
->oom_wakeups
);
2163 /* for filtering, pass "memcg" as argument. */
2164 __wake_up(&memcg_oom_waitq
, TASK_NORMAL
, 0, memcg
);
2167 static void memcg_oom_recover(struct mem_cgroup
*memcg
)
2169 if (memcg
&& atomic_read(&memcg
->under_oom
))
2170 memcg_wakeup_oom(memcg
);
2173 static void mem_cgroup_oom(struct mem_cgroup
*memcg
, gfp_t mask
, int order
)
2175 if (!current
->memcg_oom
.may_oom
)
2178 * We are in the middle of the charge context here, so we
2179 * don't want to block when potentially sitting on a callstack
2180 * that holds all kinds of filesystem and mm locks.
2182 * Also, the caller may handle a failed allocation gracefully
2183 * (like optional page cache readahead) and so an OOM killer
2184 * invocation might not even be necessary.
2186 * That's why we don't do anything here except remember the
2187 * OOM context and then deal with it at the end of the page
2188 * fault when the stack is unwound, the locks are released,
2189 * and when we know whether the fault was overall successful.
2191 css_get(&memcg
->css
);
2192 current
->memcg_oom
.memcg
= memcg
;
2193 current
->memcg_oom
.gfp_mask
= mask
;
2194 current
->memcg_oom
.order
= order
;
2198 * mem_cgroup_oom_synchronize - complete memcg OOM handling
2199 * @handle: actually kill/wait or just clean up the OOM state
2201 * This has to be called at the end of a page fault if the memcg OOM
2202 * handler was enabled.
2204 * Memcg supports userspace OOM handling where failed allocations must
2205 * sleep on a waitqueue until the userspace task resolves the
2206 * situation. Sleeping directly in the charge context with all kinds
2207 * of locks held is not a good idea, instead we remember an OOM state
2208 * in the task and mem_cgroup_oom_synchronize() has to be called at
2209 * the end of the page fault to complete the OOM handling.
2211 * Returns %true if an ongoing memcg OOM situation was detected and
2212 * completed, %false otherwise.
2214 bool mem_cgroup_oom_synchronize(bool handle
)
2216 struct mem_cgroup
*memcg
= current
->memcg_oom
.memcg
;
2217 struct oom_wait_info owait
;
2220 /* OOM is global, do not handle */
2227 owait
.memcg
= memcg
;
2228 owait
.wait
.flags
= 0;
2229 owait
.wait
.func
= memcg_oom_wake_function
;
2230 owait
.wait
.private = current
;
2231 INIT_LIST_HEAD(&owait
.wait
.task_list
);
2233 prepare_to_wait(&memcg_oom_waitq
, &owait
.wait
, TASK_KILLABLE
);
2234 mem_cgroup_mark_under_oom(memcg
);
2236 locked
= mem_cgroup_oom_trylock(memcg
);
2239 mem_cgroup_oom_notify(memcg
);
2241 if (locked
&& !memcg
->oom_kill_disable
) {
2242 mem_cgroup_unmark_under_oom(memcg
);
2243 finish_wait(&memcg_oom_waitq
, &owait
.wait
);
2244 mem_cgroup_out_of_memory(memcg
, current
->memcg_oom
.gfp_mask
,
2245 current
->memcg_oom
.order
);
2248 mem_cgroup_unmark_under_oom(memcg
);
2249 finish_wait(&memcg_oom_waitq
, &owait
.wait
);
2253 mem_cgroup_oom_unlock(memcg
);
2255 * There is no guarantee that an OOM-lock contender
2256 * sees the wakeups triggered by the OOM kill
2257 * uncharges. Wake any sleepers explicitely.
2259 memcg_oom_recover(memcg
);
2262 current
->memcg_oom
.memcg
= NULL
;
2263 css_put(&memcg
->css
);
2268 * Currently used to update mapped file statistics, but the routine can be
2269 * generalized to update other statistics as well.
2271 * Notes: Race condition
2273 * We usually use page_cgroup_lock() for accessing page_cgroup member but
2274 * it tends to be costly. But considering some conditions, we doesn't need
2275 * to do so _always_.
2277 * Considering "charge", lock_page_cgroup() is not required because all
2278 * file-stat operations happen after a page is attached to radix-tree. There
2279 * are no race with "charge".
2281 * Considering "uncharge", we know that memcg doesn't clear pc->mem_cgroup
2282 * at "uncharge" intentionally. So, we always see valid pc->mem_cgroup even
2283 * if there are race with "uncharge". Statistics itself is properly handled
2286 * Considering "move", this is an only case we see a race. To make the race
2287 * small, we check mm->moving_account and detect there are possibility of race
2288 * If there is, we take a lock.
2291 void __mem_cgroup_begin_update_page_stat(struct page
*page
,
2292 bool *locked
, unsigned long *flags
)
2294 struct mem_cgroup
*memcg
;
2295 struct page_cgroup
*pc
;
2297 pc
= lookup_page_cgroup(page
);
2299 memcg
= pc
->mem_cgroup
;
2300 if (unlikely(!memcg
|| !PageCgroupUsed(pc
)))
2303 * If this memory cgroup is not under account moving, we don't
2304 * need to take move_lock_mem_cgroup(). Because we already hold
2305 * rcu_read_lock(), any calls to move_account will be delayed until
2306 * rcu_read_unlock() if mem_cgroup_stolen() == true.
2308 if (!mem_cgroup_stolen(memcg
))
2311 move_lock_mem_cgroup(memcg
, flags
);
2312 if (memcg
!= pc
->mem_cgroup
|| !PageCgroupUsed(pc
)) {
2313 move_unlock_mem_cgroup(memcg
, flags
);
2319 void __mem_cgroup_end_update_page_stat(struct page
*page
, unsigned long *flags
)
2321 struct page_cgroup
*pc
= lookup_page_cgroup(page
);
2324 * It's guaranteed that pc->mem_cgroup never changes while
2325 * lock is held because a routine modifies pc->mem_cgroup
2326 * should take move_lock_mem_cgroup().
2328 move_unlock_mem_cgroup(pc
->mem_cgroup
, flags
);
2331 void mem_cgroup_update_page_stat(struct page
*page
,
2332 enum mem_cgroup_stat_index idx
, int val
)
2334 struct mem_cgroup
*memcg
;
2335 struct page_cgroup
*pc
= lookup_page_cgroup(page
);
2336 unsigned long uninitialized_var(flags
);
2338 if (mem_cgroup_disabled())
2341 VM_BUG_ON(!rcu_read_lock_held());
2342 memcg
= pc
->mem_cgroup
;
2343 if (unlikely(!memcg
|| !PageCgroupUsed(pc
)))
2346 this_cpu_add(memcg
->stat
->count
[idx
], val
);
2350 * size of first charge trial. "32" comes from vmscan.c's magic value.
2351 * TODO: maybe necessary to use big numbers in big irons.
2353 #define CHARGE_BATCH 32U
2354 struct memcg_stock_pcp
{
2355 struct mem_cgroup
*cached
; /* this never be root cgroup */
2356 unsigned int nr_pages
;
2357 struct work_struct work
;
2358 unsigned long flags
;
2359 #define FLUSHING_CACHED_CHARGE 0
2361 static DEFINE_PER_CPU(struct memcg_stock_pcp
, memcg_stock
);
2362 static DEFINE_MUTEX(percpu_charge_mutex
);
2365 * consume_stock: Try to consume stocked charge on this cpu.
2366 * @memcg: memcg to consume from.
2367 * @nr_pages: how many pages to charge.
2369 * The charges will only happen if @memcg matches the current cpu's memcg
2370 * stock, and at least @nr_pages are available in that stock. Failure to
2371 * service an allocation will refill the stock.
2373 * returns true if successful, false otherwise.
2375 static bool consume_stock(struct mem_cgroup
*memcg
, unsigned int nr_pages
)
2377 struct memcg_stock_pcp
*stock
;
2380 if (nr_pages
> CHARGE_BATCH
)
2383 stock
= &get_cpu_var(memcg_stock
);
2384 if (memcg
== stock
->cached
&& stock
->nr_pages
>= nr_pages
)
2385 stock
->nr_pages
-= nr_pages
;
2386 else /* need to call res_counter_charge */
2388 put_cpu_var(memcg_stock
);
2393 * Returns stocks cached in percpu to res_counter and reset cached information.
2395 static void drain_stock(struct memcg_stock_pcp
*stock
)
2397 struct mem_cgroup
*old
= stock
->cached
;
2399 if (stock
->nr_pages
) {
2400 unsigned long bytes
= stock
->nr_pages
* PAGE_SIZE
;
2402 res_counter_uncharge(&old
->res
, bytes
);
2403 if (do_swap_account
)
2404 res_counter_uncharge(&old
->memsw
, bytes
);
2405 stock
->nr_pages
= 0;
2407 stock
->cached
= NULL
;
2411 * This must be called under preempt disabled or must be called by
2412 * a thread which is pinned to local cpu.
2414 static void drain_local_stock(struct work_struct
*dummy
)
2416 struct memcg_stock_pcp
*stock
= &__get_cpu_var(memcg_stock
);
2418 clear_bit(FLUSHING_CACHED_CHARGE
, &stock
->flags
);
2421 static void __init
memcg_stock_init(void)
2425 for_each_possible_cpu(cpu
) {
2426 struct memcg_stock_pcp
*stock
=
2427 &per_cpu(memcg_stock
, cpu
);
2428 INIT_WORK(&stock
->work
, drain_local_stock
);
2433 * Cache charges(val) which is from res_counter, to local per_cpu area.
2434 * This will be consumed by consume_stock() function, later.
2436 static void refill_stock(struct mem_cgroup
*memcg
, unsigned int nr_pages
)
2438 struct memcg_stock_pcp
*stock
= &get_cpu_var(memcg_stock
);
2440 if (stock
->cached
!= memcg
) { /* reset if necessary */
2442 stock
->cached
= memcg
;
2444 stock
->nr_pages
+= nr_pages
;
2445 put_cpu_var(memcg_stock
);
2449 * Drains all per-CPU charge caches for given root_memcg resp. subtree
2450 * of the hierarchy under it. sync flag says whether we should block
2451 * until the work is done.
2453 static void drain_all_stock(struct mem_cgroup
*root_memcg
, bool sync
)
2457 /* Notify other cpus that system-wide "drain" is running */
2460 for_each_online_cpu(cpu
) {
2461 struct memcg_stock_pcp
*stock
= &per_cpu(memcg_stock
, cpu
);
2462 struct mem_cgroup
*memcg
;
2464 memcg
= stock
->cached
;
2465 if (!memcg
|| !stock
->nr_pages
)
2467 if (!mem_cgroup_same_or_subtree(root_memcg
, memcg
))
2469 if (!test_and_set_bit(FLUSHING_CACHED_CHARGE
, &stock
->flags
)) {
2471 drain_local_stock(&stock
->work
);
2473 schedule_work_on(cpu
, &stock
->work
);
2481 for_each_online_cpu(cpu
) {
2482 struct memcg_stock_pcp
*stock
= &per_cpu(memcg_stock
, cpu
);
2483 if (test_bit(FLUSHING_CACHED_CHARGE
, &stock
->flags
))
2484 flush_work(&stock
->work
);
2491 * Tries to drain stocked charges in other cpus. This function is asynchronous
2492 * and just put a work per cpu for draining localy on each cpu. Caller can
2493 * expects some charges will be back to res_counter later but cannot wait for
2496 static void drain_all_stock_async(struct mem_cgroup
*root_memcg
)
2499 * If someone calls draining, avoid adding more kworker runs.
2501 if (!mutex_trylock(&percpu_charge_mutex
))
2503 drain_all_stock(root_memcg
, false);
2504 mutex_unlock(&percpu_charge_mutex
);
2507 /* This is a synchronous drain interface. */
2508 static void drain_all_stock_sync(struct mem_cgroup
*root_memcg
)
2510 /* called when force_empty is called */
2511 mutex_lock(&percpu_charge_mutex
);
2512 drain_all_stock(root_memcg
, true);
2513 mutex_unlock(&percpu_charge_mutex
);
2517 * This function drains percpu counter value from DEAD cpu and
2518 * move it to local cpu. Note that this function can be preempted.
2520 static void mem_cgroup_drain_pcp_counter(struct mem_cgroup
*memcg
, int cpu
)
2524 spin_lock(&memcg
->pcp_counter_lock
);
2525 for (i
= 0; i
< MEM_CGROUP_STAT_NSTATS
; i
++) {
2526 long x
= per_cpu(memcg
->stat
->count
[i
], cpu
);
2528 per_cpu(memcg
->stat
->count
[i
], cpu
) = 0;
2529 memcg
->nocpu_base
.count
[i
] += x
;
2531 for (i
= 0; i
< MEM_CGROUP_EVENTS_NSTATS
; i
++) {
2532 unsigned long x
= per_cpu(memcg
->stat
->events
[i
], cpu
);
2534 per_cpu(memcg
->stat
->events
[i
], cpu
) = 0;
2535 memcg
->nocpu_base
.events
[i
] += x
;
2537 spin_unlock(&memcg
->pcp_counter_lock
);
2540 static int memcg_cpu_hotplug_callback(struct notifier_block
*nb
,
2541 unsigned long action
,
2544 int cpu
= (unsigned long)hcpu
;
2545 struct memcg_stock_pcp
*stock
;
2546 struct mem_cgroup
*iter
;
2548 if (action
== CPU_ONLINE
)
2551 if (action
!= CPU_DEAD
&& action
!= CPU_DEAD_FROZEN
)
2554 for_each_mem_cgroup(iter
)
2555 mem_cgroup_drain_pcp_counter(iter
, cpu
);
2557 stock
= &per_cpu(memcg_stock
, cpu
);
2563 /* See __mem_cgroup_try_charge() for details */
2565 CHARGE_OK
, /* success */
2566 CHARGE_RETRY
, /* need to retry but retry is not bad */
2567 CHARGE_NOMEM
, /* we can't do more. return -ENOMEM */
2568 CHARGE_WOULDBLOCK
, /* GFP_WAIT wasn't set and no enough res. */
2571 static int mem_cgroup_do_charge(struct mem_cgroup
*memcg
, gfp_t gfp_mask
,
2572 unsigned int nr_pages
, unsigned int min_pages
,
2575 unsigned long csize
= nr_pages
* PAGE_SIZE
;
2576 struct mem_cgroup
*mem_over_limit
;
2577 struct res_counter
*fail_res
;
2578 unsigned long flags
= 0;
2581 ret
= res_counter_charge(&memcg
->res
, csize
, &fail_res
);
2584 if (!do_swap_account
)
2586 ret
= res_counter_charge(&memcg
->memsw
, csize
, &fail_res
);
2590 res_counter_uncharge(&memcg
->res
, csize
);
2591 mem_over_limit
= mem_cgroup_from_res_counter(fail_res
, memsw
);
2592 flags
|= MEM_CGROUP_RECLAIM_NOSWAP
;
2594 mem_over_limit
= mem_cgroup_from_res_counter(fail_res
, res
);
2596 * Never reclaim on behalf of optional batching, retry with a
2597 * single page instead.
2599 if (nr_pages
> min_pages
)
2600 return CHARGE_RETRY
;
2602 if (!(gfp_mask
& __GFP_WAIT
))
2603 return CHARGE_WOULDBLOCK
;
2605 if (gfp_mask
& __GFP_NORETRY
)
2606 return CHARGE_NOMEM
;
2608 ret
= mem_cgroup_reclaim(mem_over_limit
, gfp_mask
, flags
);
2609 if (mem_cgroup_margin(mem_over_limit
) >= nr_pages
)
2610 return CHARGE_RETRY
;
2612 * Even though the limit is exceeded at this point, reclaim
2613 * may have been able to free some pages. Retry the charge
2614 * before killing the task.
2616 * Only for regular pages, though: huge pages are rather
2617 * unlikely to succeed so close to the limit, and we fall back
2618 * to regular pages anyway in case of failure.
2620 if (nr_pages
<= (1 << PAGE_ALLOC_COSTLY_ORDER
) && ret
)
2621 return CHARGE_RETRY
;
2624 * At task move, charge accounts can be doubly counted. So, it's
2625 * better to wait until the end of task_move if something is going on.
2627 if (mem_cgroup_wait_acct_move(mem_over_limit
))
2628 return CHARGE_RETRY
;
2631 mem_cgroup_oom(mem_over_limit
, gfp_mask
, get_order(csize
));
2633 return CHARGE_NOMEM
;
2637 * __mem_cgroup_try_charge() does
2638 * 1. detect memcg to be charged against from passed *mm and *ptr,
2639 * 2. update res_counter
2640 * 3. call memory reclaim if necessary.
2642 * In some special case, if the task is fatal, fatal_signal_pending() or
2643 * has TIF_MEMDIE, this function returns -EINTR while writing root_mem_cgroup
2644 * to *ptr. There are two reasons for this. 1: fatal threads should quit as soon
2645 * as possible without any hazards. 2: all pages should have a valid
2646 * pc->mem_cgroup. If mm is NULL and the caller doesn't pass a valid memcg
2647 * pointer, that is treated as a charge to root_mem_cgroup.
2649 * So __mem_cgroup_try_charge() will return
2650 * 0 ... on success, filling *ptr with a valid memcg pointer.
2651 * -ENOMEM ... charge failure because of resource limits.
2652 * -EINTR ... if thread is fatal. *ptr is filled with root_mem_cgroup.
2654 * Unlike the exported interface, an "oom" parameter is added. if oom==true,
2655 * the oom-killer can be invoked.
2657 static int __mem_cgroup_try_charge(struct mm_struct
*mm
,
2659 unsigned int nr_pages
,
2660 struct mem_cgroup
**ptr
,
2663 unsigned int batch
= max(CHARGE_BATCH
, nr_pages
);
2664 int nr_oom_retries
= MEM_CGROUP_RECLAIM_RETRIES
;
2665 struct mem_cgroup
*memcg
= NULL
;
2669 * Unlike gloval-vm's OOM-kill, we're not in memory shortage
2670 * in system level. So, allow to go ahead dying process in addition to
2673 if (unlikely(test_thread_flag(TIF_MEMDIE
)
2674 || fatal_signal_pending(current
)))
2677 if (unlikely(task_in_memcg_oom(current
)))
2681 * We always charge the cgroup the mm_struct belongs to.
2682 * The mm_struct's mem_cgroup changes on task migration if the
2683 * thread group leader migrates. It's possible that mm is not
2684 * set, if so charge the root memcg (happens for pagecache usage).
2687 *ptr
= root_mem_cgroup
;
2689 if (*ptr
) { /* css should be a valid one */
2691 if (mem_cgroup_is_root(memcg
))
2693 if (consume_stock(memcg
, nr_pages
))
2695 css_get(&memcg
->css
);
2697 struct task_struct
*p
;
2700 p
= rcu_dereference(mm
->owner
);
2702 * Because we don't have task_lock(), "p" can exit.
2703 * In that case, "memcg" can point to root or p can be NULL with
2704 * race with swapoff. Then, we have small risk of mis-accouning.
2705 * But such kind of mis-account by race always happens because
2706 * we don't have cgroup_mutex(). It's overkill and we allo that
2708 * (*) swapoff at el will charge against mm-struct not against
2709 * task-struct. So, mm->owner can be NULL.
2711 memcg
= mem_cgroup_from_task(p
);
2713 memcg
= root_mem_cgroup
;
2714 if (mem_cgroup_is_root(memcg
)) {
2718 if (consume_stock(memcg
, nr_pages
)) {
2720 * It seems dagerous to access memcg without css_get().
2721 * But considering how consume_stok works, it's not
2722 * necessary. If consume_stock success, some charges
2723 * from this memcg are cached on this cpu. So, we
2724 * don't need to call css_get()/css_tryget() before
2725 * calling consume_stock().
2730 /* after here, we may be blocked. we need to get refcnt */
2731 if (!css_tryget(&memcg
->css
)) {
2739 bool invoke_oom
= oom
&& !nr_oom_retries
;
2741 /* If killed, bypass charge */
2742 if (fatal_signal_pending(current
)) {
2743 css_put(&memcg
->css
);
2747 ret
= mem_cgroup_do_charge(memcg
, gfp_mask
, batch
,
2748 nr_pages
, invoke_oom
);
2752 case CHARGE_RETRY
: /* not in OOM situation but retry */
2754 css_put(&memcg
->css
);
2757 case CHARGE_WOULDBLOCK
: /* !__GFP_WAIT */
2758 css_put(&memcg
->css
);
2760 case CHARGE_NOMEM
: /* OOM routine works */
2761 if (!oom
|| invoke_oom
) {
2762 css_put(&memcg
->css
);
2768 } while (ret
!= CHARGE_OK
);
2770 if (batch
> nr_pages
)
2771 refill_stock(memcg
, batch
- nr_pages
);
2772 css_put(&memcg
->css
);
2777 if (!(gfp_mask
& __GFP_NOFAIL
)) {
2782 *ptr
= root_mem_cgroup
;
2787 * Somemtimes we have to undo a charge we got by try_charge().
2788 * This function is for that and do uncharge, put css's refcnt.
2789 * gotten by try_charge().
2791 static void __mem_cgroup_cancel_charge(struct mem_cgroup
*memcg
,
2792 unsigned int nr_pages
)
2794 if (!mem_cgroup_is_root(memcg
)) {
2795 unsigned long bytes
= nr_pages
* PAGE_SIZE
;
2797 res_counter_uncharge(&memcg
->res
, bytes
);
2798 if (do_swap_account
)
2799 res_counter_uncharge(&memcg
->memsw
, bytes
);
2804 * Cancel chrages in this cgroup....doesn't propagate to parent cgroup.
2805 * This is useful when moving usage to parent cgroup.
2807 static void __mem_cgroup_cancel_local_charge(struct mem_cgroup
*memcg
,
2808 unsigned int nr_pages
)
2810 unsigned long bytes
= nr_pages
* PAGE_SIZE
;
2812 if (mem_cgroup_is_root(memcg
))
2815 res_counter_uncharge_until(&memcg
->res
, memcg
->res
.parent
, bytes
);
2816 if (do_swap_account
)
2817 res_counter_uncharge_until(&memcg
->memsw
,
2818 memcg
->memsw
.parent
, bytes
);
2822 * A helper function to get mem_cgroup from ID. must be called under
2823 * rcu_read_lock(). The caller is responsible for calling css_tryget if
2824 * the mem_cgroup is used for charging. (dropping refcnt from swap can be
2825 * called against removed memcg.)
2827 static struct mem_cgroup
*mem_cgroup_lookup(unsigned short id
)
2829 struct cgroup_subsys_state
*css
;
2831 /* ID 0 is unused ID */
2834 css
= css_lookup(&mem_cgroup_subsys
, id
);
2837 return mem_cgroup_from_css(css
);
2840 struct mem_cgroup
*try_get_mem_cgroup_from_page(struct page
*page
)
2842 struct mem_cgroup
*memcg
= NULL
;
2843 struct page_cgroup
*pc
;
2847 VM_BUG_ON(!PageLocked(page
));
2849 pc
= lookup_page_cgroup(page
);
2850 lock_page_cgroup(pc
);
2851 if (PageCgroupUsed(pc
)) {
2852 memcg
= pc
->mem_cgroup
;
2853 if (memcg
&& !css_tryget(&memcg
->css
))
2855 } else if (PageSwapCache(page
)) {
2856 ent
.val
= page_private(page
);
2857 id
= lookup_swap_cgroup_id(ent
);
2859 memcg
= mem_cgroup_lookup(id
);
2860 if (memcg
&& !css_tryget(&memcg
->css
))
2864 unlock_page_cgroup(pc
);
2868 static void __mem_cgroup_commit_charge(struct mem_cgroup
*memcg
,
2870 unsigned int nr_pages
,
2871 enum charge_type ctype
,
2874 struct page_cgroup
*pc
= lookup_page_cgroup(page
);
2875 struct zone
*uninitialized_var(zone
);
2876 struct lruvec
*lruvec
;
2877 bool was_on_lru
= false;
2880 lock_page_cgroup(pc
);
2881 VM_BUG_ON(PageCgroupUsed(pc
));
2883 * we don't need page_cgroup_lock about tail pages, becase they are not
2884 * accessed by any other context at this point.
2888 * In some cases, SwapCache and FUSE(splice_buf->radixtree), the page
2889 * may already be on some other mem_cgroup's LRU. Take care of it.
2892 zone
= page_zone(page
);
2893 spin_lock_irq(&zone
->lru_lock
);
2894 if (PageLRU(page
)) {
2895 lruvec
= mem_cgroup_zone_lruvec(zone
, pc
->mem_cgroup
);
2897 del_page_from_lru_list(page
, lruvec
, page_lru(page
));
2902 pc
->mem_cgroup
= memcg
;
2904 * We access a page_cgroup asynchronously without lock_page_cgroup().
2905 * Especially when a page_cgroup is taken from a page, pc->mem_cgroup
2906 * is accessed after testing USED bit. To make pc->mem_cgroup visible
2907 * before USED bit, we need memory barrier here.
2908 * See mem_cgroup_add_lru_list(), etc.
2911 SetPageCgroupUsed(pc
);
2915 lruvec
= mem_cgroup_zone_lruvec(zone
, pc
->mem_cgroup
);
2916 VM_BUG_ON(PageLRU(page
));
2918 add_page_to_lru_list(page
, lruvec
, page_lru(page
));
2920 spin_unlock_irq(&zone
->lru_lock
);
2923 if (ctype
== MEM_CGROUP_CHARGE_TYPE_ANON
)
2928 mem_cgroup_charge_statistics(memcg
, page
, anon
, nr_pages
);
2929 unlock_page_cgroup(pc
);
2932 * "charge_statistics" updated event counter. Then, check it.
2933 * Insert ancestor (and ancestor's ancestors), to softlimit RB-tree.
2934 * if they exceeds softlimit.
2936 memcg_check_events(memcg
, page
);
2939 static DEFINE_MUTEX(set_limit_mutex
);
2941 #ifdef CONFIG_MEMCG_KMEM
2942 static inline bool memcg_can_account_kmem(struct mem_cgroup
*memcg
)
2944 return !mem_cgroup_disabled() && !mem_cgroup_is_root(memcg
) &&
2945 (memcg
->kmem_account_flags
& KMEM_ACCOUNTED_MASK
);
2949 * This is a bit cumbersome, but it is rarely used and avoids a backpointer
2950 * in the memcg_cache_params struct.
2952 static struct kmem_cache
*memcg_params_to_cache(struct memcg_cache_params
*p
)
2954 struct kmem_cache
*cachep
;
2956 VM_BUG_ON(p
->is_root_cache
);
2957 cachep
= p
->root_cache
;
2958 return cachep
->memcg_params
->memcg_caches
[memcg_cache_id(p
->memcg
)];
2961 #ifdef CONFIG_SLABINFO
2962 static int mem_cgroup_slabinfo_read(struct cgroup_subsys_state
*css
,
2963 struct cftype
*cft
, struct seq_file
*m
)
2965 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
2966 struct memcg_cache_params
*params
;
2968 if (!memcg_can_account_kmem(memcg
))
2971 print_slabinfo_header(m
);
2973 mutex_lock(&memcg
->slab_caches_mutex
);
2974 list_for_each_entry(params
, &memcg
->memcg_slab_caches
, list
)
2975 cache_show(memcg_params_to_cache(params
), m
);
2976 mutex_unlock(&memcg
->slab_caches_mutex
);
2982 static int memcg_charge_kmem(struct mem_cgroup
*memcg
, gfp_t gfp
, u64 size
)
2984 struct res_counter
*fail_res
;
2985 struct mem_cgroup
*_memcg
;
2989 ret
= res_counter_charge(&memcg
->kmem
, size
, &fail_res
);
2994 * Conditions under which we can wait for the oom_killer. Those are
2995 * the same conditions tested by the core page allocator
2997 may_oom
= (gfp
& __GFP_FS
) && !(gfp
& __GFP_NORETRY
);
3000 ret
= __mem_cgroup_try_charge(NULL
, gfp
, size
>> PAGE_SHIFT
,
3003 if (ret
== -EINTR
) {
3005 * __mem_cgroup_try_charge() chosed to bypass to root due to
3006 * OOM kill or fatal signal. Since our only options are to
3007 * either fail the allocation or charge it to this cgroup, do
3008 * it as a temporary condition. But we can't fail. From a
3009 * kmem/slab perspective, the cache has already been selected,
3010 * by mem_cgroup_kmem_get_cache(), so it is too late to change
3013 * This condition will only trigger if the task entered
3014 * memcg_charge_kmem in a sane state, but was OOM-killed during
3015 * __mem_cgroup_try_charge() above. Tasks that were already
3016 * dying when the allocation triggers should have been already
3017 * directed to the root cgroup in memcontrol.h
3019 res_counter_charge_nofail(&memcg
->res
, size
, &fail_res
);
3020 if (do_swap_account
)
3021 res_counter_charge_nofail(&memcg
->memsw
, size
,
3025 res_counter_uncharge(&memcg
->kmem
, size
);
3030 static void memcg_uncharge_kmem(struct mem_cgroup
*memcg
, u64 size
)
3032 res_counter_uncharge(&memcg
->res
, size
);
3033 if (do_swap_account
)
3034 res_counter_uncharge(&memcg
->memsw
, size
);
3037 if (res_counter_uncharge(&memcg
->kmem
, size
))
3041 * Releases a reference taken in kmem_cgroup_css_offline in case
3042 * this last uncharge is racing with the offlining code or it is
3043 * outliving the memcg existence.
3045 * The memory barrier imposed by test&clear is paired with the
3046 * explicit one in memcg_kmem_mark_dead().
3048 if (memcg_kmem_test_and_clear_dead(memcg
))
3049 css_put(&memcg
->css
);
3052 void memcg_cache_list_add(struct mem_cgroup
*memcg
, struct kmem_cache
*cachep
)
3057 mutex_lock(&memcg
->slab_caches_mutex
);
3058 list_add(&cachep
->memcg_params
->list
, &memcg
->memcg_slab_caches
);
3059 mutex_unlock(&memcg
->slab_caches_mutex
);
3063 * helper for acessing a memcg's index. It will be used as an index in the
3064 * child cache array in kmem_cache, and also to derive its name. This function
3065 * will return -1 when this is not a kmem-limited memcg.
3067 int memcg_cache_id(struct mem_cgroup
*memcg
)
3069 return memcg
? memcg
->kmemcg_id
: -1;
3073 * This ends up being protected by the set_limit mutex, during normal
3074 * operation, because that is its main call site.
3076 * But when we create a new cache, we can call this as well if its parent
3077 * is kmem-limited. That will have to hold set_limit_mutex as well.
3079 int memcg_update_cache_sizes(struct mem_cgroup
*memcg
)
3083 num
= ida_simple_get(&kmem_limited_groups
,
3084 0, MEMCG_CACHES_MAX_SIZE
, GFP_KERNEL
);
3088 * After this point, kmem_accounted (that we test atomically in
3089 * the beginning of this conditional), is no longer 0. This
3090 * guarantees only one process will set the following boolean
3091 * to true. We don't need test_and_set because we're protected
3092 * by the set_limit_mutex anyway.
3094 memcg_kmem_set_activated(memcg
);
3096 ret
= memcg_update_all_caches(num
+1);
3098 ida_simple_remove(&kmem_limited_groups
, num
);
3099 memcg_kmem_clear_activated(memcg
);
3103 memcg
->kmemcg_id
= num
;
3104 INIT_LIST_HEAD(&memcg
->memcg_slab_caches
);
3105 mutex_init(&memcg
->slab_caches_mutex
);
3109 static size_t memcg_caches_array_size(int num_groups
)
3112 if (num_groups
<= 0)
3115 size
= 2 * num_groups
;
3116 if (size
< MEMCG_CACHES_MIN_SIZE
)
3117 size
= MEMCG_CACHES_MIN_SIZE
;
3118 else if (size
> MEMCG_CACHES_MAX_SIZE
)
3119 size
= MEMCG_CACHES_MAX_SIZE
;
3125 * We should update the current array size iff all caches updates succeed. This
3126 * can only be done from the slab side. The slab mutex needs to be held when
3129 void memcg_update_array_size(int num
)
3131 if (num
> memcg_limited_groups_array_size
)
3132 memcg_limited_groups_array_size
= memcg_caches_array_size(num
);
3135 static void kmem_cache_destroy_work_func(struct work_struct
*w
);
3137 int memcg_update_cache_size(struct kmem_cache
*s
, int num_groups
)
3139 struct memcg_cache_params
*cur_params
= s
->memcg_params
;
3141 VM_BUG_ON(s
->memcg_params
&& !s
->memcg_params
->is_root_cache
);
3143 if (num_groups
> memcg_limited_groups_array_size
) {
3145 ssize_t size
= memcg_caches_array_size(num_groups
);
3147 size
*= sizeof(void *);
3148 size
+= offsetof(struct memcg_cache_params
, memcg_caches
);
3150 s
->memcg_params
= kzalloc(size
, GFP_KERNEL
);
3151 if (!s
->memcg_params
) {
3152 s
->memcg_params
= cur_params
;
3156 s
->memcg_params
->is_root_cache
= true;
3159 * There is the chance it will be bigger than
3160 * memcg_limited_groups_array_size, if we failed an allocation
3161 * in a cache, in which case all caches updated before it, will
3162 * have a bigger array.
3164 * But if that is the case, the data after
3165 * memcg_limited_groups_array_size is certainly unused
3167 for (i
= 0; i
< memcg_limited_groups_array_size
; i
++) {
3168 if (!cur_params
->memcg_caches
[i
])
3170 s
->memcg_params
->memcg_caches
[i
] =
3171 cur_params
->memcg_caches
[i
];
3175 * Ideally, we would wait until all caches succeed, and only
3176 * then free the old one. But this is not worth the extra
3177 * pointer per-cache we'd have to have for this.
3179 * It is not a big deal if some caches are left with a size
3180 * bigger than the others. And all updates will reset this
3188 int memcg_register_cache(struct mem_cgroup
*memcg
, struct kmem_cache
*s
,
3189 struct kmem_cache
*root_cache
)
3193 if (!memcg_kmem_enabled())
3197 size
= offsetof(struct memcg_cache_params
, memcg_caches
);
3198 size
+= memcg_limited_groups_array_size
* sizeof(void *);
3200 size
= sizeof(struct memcg_cache_params
);
3202 s
->memcg_params
= kzalloc(size
, GFP_KERNEL
);
3203 if (!s
->memcg_params
)
3207 s
->memcg_params
->memcg
= memcg
;
3208 s
->memcg_params
->root_cache
= root_cache
;
3209 INIT_WORK(&s
->memcg_params
->destroy
,
3210 kmem_cache_destroy_work_func
);
3212 s
->memcg_params
->is_root_cache
= true;
3217 void memcg_release_cache(struct kmem_cache
*s
)
3219 struct kmem_cache
*root
;
3220 struct mem_cgroup
*memcg
;
3224 * This happens, for instance, when a root cache goes away before we
3227 if (!s
->memcg_params
)
3230 if (s
->memcg_params
->is_root_cache
)
3233 memcg
= s
->memcg_params
->memcg
;
3234 id
= memcg_cache_id(memcg
);
3236 root
= s
->memcg_params
->root_cache
;
3237 root
->memcg_params
->memcg_caches
[id
] = NULL
;
3239 mutex_lock(&memcg
->slab_caches_mutex
);
3240 list_del(&s
->memcg_params
->list
);
3241 mutex_unlock(&memcg
->slab_caches_mutex
);
3243 css_put(&memcg
->css
);
3245 kfree(s
->memcg_params
);
3249 * During the creation a new cache, we need to disable our accounting mechanism
3250 * altogether. This is true even if we are not creating, but rather just
3251 * enqueing new caches to be created.
3253 * This is because that process will trigger allocations; some visible, like
3254 * explicit kmallocs to auxiliary data structures, name strings and internal
3255 * cache structures; some well concealed, like INIT_WORK() that can allocate
3256 * objects during debug.
3258 * If any allocation happens during memcg_kmem_get_cache, we will recurse back
3259 * to it. This may not be a bounded recursion: since the first cache creation
3260 * failed to complete (waiting on the allocation), we'll just try to create the
3261 * cache again, failing at the same point.
3263 * memcg_kmem_get_cache is prepared to abort after seeing a positive count of
3264 * memcg_kmem_skip_account. So we enclose anything that might allocate memory
3265 * inside the following two functions.
3267 static inline void memcg_stop_kmem_account(void)
3269 VM_BUG_ON(!current
->mm
);
3270 current
->memcg_kmem_skip_account
++;
3273 static inline void memcg_resume_kmem_account(void)
3275 VM_BUG_ON(!current
->mm
);
3276 current
->memcg_kmem_skip_account
--;
3279 static void kmem_cache_destroy_work_func(struct work_struct
*w
)
3281 struct kmem_cache
*cachep
;
3282 struct memcg_cache_params
*p
;
3284 p
= container_of(w
, struct memcg_cache_params
, destroy
);
3286 cachep
= memcg_params_to_cache(p
);
3289 * If we get down to 0 after shrink, we could delete right away.
3290 * However, memcg_release_pages() already puts us back in the workqueue
3291 * in that case. If we proceed deleting, we'll get a dangling
3292 * reference, and removing the object from the workqueue in that case
3293 * is unnecessary complication. We are not a fast path.
3295 * Note that this case is fundamentally different from racing with
3296 * shrink_slab(): if memcg_cgroup_destroy_cache() is called in
3297 * kmem_cache_shrink, not only we would be reinserting a dead cache
3298 * into the queue, but doing so from inside the worker racing to
3301 * So if we aren't down to zero, we'll just schedule a worker and try
3304 if (atomic_read(&cachep
->memcg_params
->nr_pages
) != 0) {
3305 kmem_cache_shrink(cachep
);
3306 if (atomic_read(&cachep
->memcg_params
->nr_pages
) == 0)
3309 kmem_cache_destroy(cachep
);
3312 void mem_cgroup_destroy_cache(struct kmem_cache
*cachep
)
3314 if (!cachep
->memcg_params
->dead
)
3318 * There are many ways in which we can get here.
3320 * We can get to a memory-pressure situation while the delayed work is
3321 * still pending to run. The vmscan shrinkers can then release all
3322 * cache memory and get us to destruction. If this is the case, we'll
3323 * be executed twice, which is a bug (the second time will execute over
3324 * bogus data). In this case, cancelling the work should be fine.
3326 * But we can also get here from the worker itself, if
3327 * kmem_cache_shrink is enough to shake all the remaining objects and
3328 * get the page count to 0. In this case, we'll deadlock if we try to
3329 * cancel the work (the worker runs with an internal lock held, which
3330 * is the same lock we would hold for cancel_work_sync().)
3332 * Since we can't possibly know who got us here, just refrain from
3333 * running if there is already work pending
3335 if (work_pending(&cachep
->memcg_params
->destroy
))
3338 * We have to defer the actual destroying to a workqueue, because
3339 * we might currently be in a context that cannot sleep.
3341 schedule_work(&cachep
->memcg_params
->destroy
);
3345 * This lock protects updaters, not readers. We want readers to be as fast as
3346 * they can, and they will either see NULL or a valid cache value. Our model
3347 * allow them to see NULL, in which case the root memcg will be selected.
3349 * We need this lock because multiple allocations to the same cache from a non
3350 * will span more than one worker. Only one of them can create the cache.
3352 static DEFINE_MUTEX(memcg_cache_mutex
);
3355 * Called with memcg_cache_mutex held
3357 static struct kmem_cache
*kmem_cache_dup(struct mem_cgroup
*memcg
,
3358 struct kmem_cache
*s
)
3360 struct kmem_cache
*new;
3361 static char *tmp_name
= NULL
;
3363 lockdep_assert_held(&memcg_cache_mutex
);
3366 * kmem_cache_create_memcg duplicates the given name and
3367 * cgroup_name for this name requires RCU context.
3368 * This static temporary buffer is used to prevent from
3369 * pointless shortliving allocation.
3372 tmp_name
= kmalloc(PATH_MAX
, GFP_KERNEL
);
3378 snprintf(tmp_name
, PATH_MAX
, "%s(%d:%s)", s
->name
,
3379 memcg_cache_id(memcg
), cgroup_name(memcg
->css
.cgroup
));
3382 new = kmem_cache_create_memcg(memcg
, tmp_name
, s
->object_size
, s
->align
,
3383 (s
->flags
& ~SLAB_PANIC
), s
->ctor
, s
);
3386 new->allocflags
|= __GFP_KMEMCG
;
3391 static struct kmem_cache
*memcg_create_kmem_cache(struct mem_cgroup
*memcg
,
3392 struct kmem_cache
*cachep
)
3394 struct kmem_cache
*new_cachep
;
3397 BUG_ON(!memcg_can_account_kmem(memcg
));
3399 idx
= memcg_cache_id(memcg
);
3401 mutex_lock(&memcg_cache_mutex
);
3402 new_cachep
= cachep
->memcg_params
->memcg_caches
[idx
];
3404 css_put(&memcg
->css
);
3408 new_cachep
= kmem_cache_dup(memcg
, cachep
);
3409 if (new_cachep
== NULL
) {
3410 new_cachep
= cachep
;
3411 css_put(&memcg
->css
);
3415 atomic_set(&new_cachep
->memcg_params
->nr_pages
, 0);
3417 cachep
->memcg_params
->memcg_caches
[idx
] = new_cachep
;
3419 * the readers won't lock, make sure everybody sees the updated value,
3420 * so they won't put stuff in the queue again for no reason
3424 mutex_unlock(&memcg_cache_mutex
);
3428 void kmem_cache_destroy_memcg_children(struct kmem_cache
*s
)
3430 struct kmem_cache
*c
;
3433 if (!s
->memcg_params
)
3435 if (!s
->memcg_params
->is_root_cache
)
3439 * If the cache is being destroyed, we trust that there is no one else
3440 * requesting objects from it. Even if there are, the sanity checks in
3441 * kmem_cache_destroy should caught this ill-case.
3443 * Still, we don't want anyone else freeing memcg_caches under our
3444 * noses, which can happen if a new memcg comes to life. As usual,
3445 * we'll take the set_limit_mutex to protect ourselves against this.
3447 mutex_lock(&set_limit_mutex
);
3448 for (i
= 0; i
< memcg_limited_groups_array_size
; i
++) {
3449 c
= s
->memcg_params
->memcg_caches
[i
];
3454 * We will now manually delete the caches, so to avoid races
3455 * we need to cancel all pending destruction workers and
3456 * proceed with destruction ourselves.
3458 * kmem_cache_destroy() will call kmem_cache_shrink internally,
3459 * and that could spawn the workers again: it is likely that
3460 * the cache still have active pages until this very moment.
3461 * This would lead us back to mem_cgroup_destroy_cache.
3463 * But that will not execute at all if the "dead" flag is not
3464 * set, so flip it down to guarantee we are in control.
3466 c
->memcg_params
->dead
= false;
3467 cancel_work_sync(&c
->memcg_params
->destroy
);
3468 kmem_cache_destroy(c
);
3470 mutex_unlock(&set_limit_mutex
);
3473 struct create_work
{
3474 struct mem_cgroup
*memcg
;
3475 struct kmem_cache
*cachep
;
3476 struct work_struct work
;
3479 static void mem_cgroup_destroy_all_caches(struct mem_cgroup
*memcg
)
3481 struct kmem_cache
*cachep
;
3482 struct memcg_cache_params
*params
;
3484 if (!memcg_kmem_is_active(memcg
))
3487 mutex_lock(&memcg
->slab_caches_mutex
);
3488 list_for_each_entry(params
, &memcg
->memcg_slab_caches
, list
) {
3489 cachep
= memcg_params_to_cache(params
);
3490 cachep
->memcg_params
->dead
= true;
3491 schedule_work(&cachep
->memcg_params
->destroy
);
3493 mutex_unlock(&memcg
->slab_caches_mutex
);
3496 static void memcg_create_cache_work_func(struct work_struct
*w
)
3498 struct create_work
*cw
;
3500 cw
= container_of(w
, struct create_work
, work
);
3501 memcg_create_kmem_cache(cw
->memcg
, cw
->cachep
);
3506 * Enqueue the creation of a per-memcg kmem_cache.
3508 static void __memcg_create_cache_enqueue(struct mem_cgroup
*memcg
,
3509 struct kmem_cache
*cachep
)
3511 struct create_work
*cw
;
3513 cw
= kmalloc(sizeof(struct create_work
), GFP_NOWAIT
);
3515 css_put(&memcg
->css
);
3520 cw
->cachep
= cachep
;
3522 INIT_WORK(&cw
->work
, memcg_create_cache_work_func
);
3523 schedule_work(&cw
->work
);
3526 static void memcg_create_cache_enqueue(struct mem_cgroup
*memcg
,
3527 struct kmem_cache
*cachep
)
3530 * We need to stop accounting when we kmalloc, because if the
3531 * corresponding kmalloc cache is not yet created, the first allocation
3532 * in __memcg_create_cache_enqueue will recurse.
3534 * However, it is better to enclose the whole function. Depending on
3535 * the debugging options enabled, INIT_WORK(), for instance, can
3536 * trigger an allocation. This too, will make us recurse. Because at
3537 * this point we can't allow ourselves back into memcg_kmem_get_cache,
3538 * the safest choice is to do it like this, wrapping the whole function.
3540 memcg_stop_kmem_account();
3541 __memcg_create_cache_enqueue(memcg
, cachep
);
3542 memcg_resume_kmem_account();
3545 * Return the kmem_cache we're supposed to use for a slab allocation.
3546 * We try to use the current memcg's version of the cache.
3548 * If the cache does not exist yet, if we are the first user of it,
3549 * we either create it immediately, if possible, or create it asynchronously
3551 * In the latter case, we will let the current allocation go through with
3552 * the original cache.
3554 * Can't be called in interrupt context or from kernel threads.
3555 * This function needs to be called with rcu_read_lock() held.
3557 struct kmem_cache
*__memcg_kmem_get_cache(struct kmem_cache
*cachep
,
3560 struct mem_cgroup
*memcg
;
3563 VM_BUG_ON(!cachep
->memcg_params
);
3564 VM_BUG_ON(!cachep
->memcg_params
->is_root_cache
);
3566 if (!current
->mm
|| current
->memcg_kmem_skip_account
)
3570 memcg
= mem_cgroup_from_task(rcu_dereference(current
->mm
->owner
));
3572 if (!memcg_can_account_kmem(memcg
))
3575 idx
= memcg_cache_id(memcg
);
3578 * barrier to mare sure we're always seeing the up to date value. The
3579 * code updating memcg_caches will issue a write barrier to match this.
3581 read_barrier_depends();
3582 if (likely(cachep
->memcg_params
->memcg_caches
[idx
])) {
3583 cachep
= cachep
->memcg_params
->memcg_caches
[idx
];
3587 /* The corresponding put will be done in the workqueue. */
3588 if (!css_tryget(&memcg
->css
))
3593 * If we are in a safe context (can wait, and not in interrupt
3594 * context), we could be be predictable and return right away.
3595 * This would guarantee that the allocation being performed
3596 * already belongs in the new cache.
3598 * However, there are some clashes that can arrive from locking.
3599 * For instance, because we acquire the slab_mutex while doing
3600 * kmem_cache_dup, this means no further allocation could happen
3601 * with the slab_mutex held.
3603 * Also, because cache creation issue get_online_cpus(), this
3604 * creates a lock chain: memcg_slab_mutex -> cpu_hotplug_mutex,
3605 * that ends up reversed during cpu hotplug. (cpuset allocates
3606 * a bunch of GFP_KERNEL memory during cpuup). Due to all that,
3607 * better to defer everything.
3609 memcg_create_cache_enqueue(memcg
, cachep
);
3615 EXPORT_SYMBOL(__memcg_kmem_get_cache
);
3618 * We need to verify if the allocation against current->mm->owner's memcg is
3619 * possible for the given order. But the page is not allocated yet, so we'll
3620 * need a further commit step to do the final arrangements.
3622 * It is possible for the task to switch cgroups in this mean time, so at
3623 * commit time, we can't rely on task conversion any longer. We'll then use
3624 * the handle argument to return to the caller which cgroup we should commit
3625 * against. We could also return the memcg directly and avoid the pointer
3626 * passing, but a boolean return value gives better semantics considering
3627 * the compiled-out case as well.
3629 * Returning true means the allocation is possible.
3632 __memcg_kmem_newpage_charge(gfp_t gfp
, struct mem_cgroup
**_memcg
, int order
)
3634 struct mem_cgroup
*memcg
;
3640 * Disabling accounting is only relevant for some specific memcg
3641 * internal allocations. Therefore we would initially not have such
3642 * check here, since direct calls to the page allocator that are marked
3643 * with GFP_KMEMCG only happen outside memcg core. We are mostly
3644 * concerned with cache allocations, and by having this test at
3645 * memcg_kmem_get_cache, we are already able to relay the allocation to
3646 * the root cache and bypass the memcg cache altogether.
3648 * There is one exception, though: the SLUB allocator does not create
3649 * large order caches, but rather service large kmallocs directly from
3650 * the page allocator. Therefore, the following sequence when backed by
3651 * the SLUB allocator:
3653 * memcg_stop_kmem_account();
3654 * kmalloc(<large_number>)
3655 * memcg_resume_kmem_account();
3657 * would effectively ignore the fact that we should skip accounting,
3658 * since it will drive us directly to this function without passing
3659 * through the cache selector memcg_kmem_get_cache. Such large
3660 * allocations are extremely rare but can happen, for instance, for the
3661 * cache arrays. We bring this test here.
3663 if (!current
->mm
|| current
->memcg_kmem_skip_account
)
3666 memcg
= try_get_mem_cgroup_from_mm(current
->mm
);
3669 * very rare case described in mem_cgroup_from_task. Unfortunately there
3670 * isn't much we can do without complicating this too much, and it would
3671 * be gfp-dependent anyway. Just let it go
3673 if (unlikely(!memcg
))
3676 if (!memcg_can_account_kmem(memcg
)) {
3677 css_put(&memcg
->css
);
3681 ret
= memcg_charge_kmem(memcg
, gfp
, PAGE_SIZE
<< order
);
3685 css_put(&memcg
->css
);
3689 void __memcg_kmem_commit_charge(struct page
*page
, struct mem_cgroup
*memcg
,
3692 struct page_cgroup
*pc
;
3694 VM_BUG_ON(mem_cgroup_is_root(memcg
));
3696 /* The page allocation failed. Revert */
3698 memcg_uncharge_kmem(memcg
, PAGE_SIZE
<< order
);
3702 pc
= lookup_page_cgroup(page
);
3703 lock_page_cgroup(pc
);
3704 pc
->mem_cgroup
= memcg
;
3705 SetPageCgroupUsed(pc
);
3706 unlock_page_cgroup(pc
);
3709 void __memcg_kmem_uncharge_pages(struct page
*page
, int order
)
3711 struct mem_cgroup
*memcg
= NULL
;
3712 struct page_cgroup
*pc
;
3715 pc
= lookup_page_cgroup(page
);
3717 * Fast unlocked return. Theoretically might have changed, have to
3718 * check again after locking.
3720 if (!PageCgroupUsed(pc
))
3723 lock_page_cgroup(pc
);
3724 if (PageCgroupUsed(pc
)) {
3725 memcg
= pc
->mem_cgroup
;
3726 ClearPageCgroupUsed(pc
);
3728 unlock_page_cgroup(pc
);
3731 * We trust that only if there is a memcg associated with the page, it
3732 * is a valid allocation
3737 VM_BUG_ON(mem_cgroup_is_root(memcg
));
3738 memcg_uncharge_kmem(memcg
, PAGE_SIZE
<< order
);
3741 static inline void mem_cgroup_destroy_all_caches(struct mem_cgroup
*memcg
)
3744 #endif /* CONFIG_MEMCG_KMEM */
3746 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
3748 #define PCGF_NOCOPY_AT_SPLIT (1 << PCG_LOCK | 1 << PCG_MIGRATION)
3750 * Because tail pages are not marked as "used", set it. We're under
3751 * zone->lru_lock, 'splitting on pmd' and compound_lock.
3752 * charge/uncharge will be never happen and move_account() is done under
3753 * compound_lock(), so we don't have to take care of races.
3755 void mem_cgroup_split_huge_fixup(struct page
*head
)
3757 struct page_cgroup
*head_pc
= lookup_page_cgroup(head
);
3758 struct page_cgroup
*pc
;
3759 struct mem_cgroup
*memcg
;
3762 if (mem_cgroup_disabled())
3765 memcg
= head_pc
->mem_cgroup
;
3766 for (i
= 1; i
< HPAGE_PMD_NR
; i
++) {
3768 pc
->mem_cgroup
= memcg
;
3769 smp_wmb();/* see __commit_charge() */
3770 pc
->flags
= head_pc
->flags
& ~PCGF_NOCOPY_AT_SPLIT
;
3772 __this_cpu_sub(memcg
->stat
->count
[MEM_CGROUP_STAT_RSS_HUGE
],
3775 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
3778 void mem_cgroup_move_account_page_stat(struct mem_cgroup
*from
,
3779 struct mem_cgroup
*to
,
3780 unsigned int nr_pages
,
3781 enum mem_cgroup_stat_index idx
)
3783 /* Update stat data for mem_cgroup */
3785 WARN_ON_ONCE(from
->stat
->count
[idx
] < nr_pages
);
3786 __this_cpu_sub(from
->stat
->count
[idx
], nr_pages
);
3787 __this_cpu_add(to
->stat
->count
[idx
], nr_pages
);
3792 * mem_cgroup_move_account - move account of the page
3794 * @nr_pages: number of regular pages (>1 for huge pages)
3795 * @pc: page_cgroup of the page.
3796 * @from: mem_cgroup which the page is moved from.
3797 * @to: mem_cgroup which the page is moved to. @from != @to.
3799 * The caller must confirm following.
3800 * - page is not on LRU (isolate_page() is useful.)
3801 * - compound_lock is held when nr_pages > 1
3803 * This function doesn't do "charge" to new cgroup and doesn't do "uncharge"
3806 static int mem_cgroup_move_account(struct page
*page
,
3807 unsigned int nr_pages
,
3808 struct page_cgroup
*pc
,
3809 struct mem_cgroup
*from
,
3810 struct mem_cgroup
*to
)
3812 unsigned long flags
;
3814 bool anon
= PageAnon(page
);
3816 VM_BUG_ON(from
== to
);
3817 VM_BUG_ON(PageLRU(page
));
3819 * The page is isolated from LRU. So, collapse function
3820 * will not handle this page. But page splitting can happen.
3821 * Do this check under compound_page_lock(). The caller should
3825 if (nr_pages
> 1 && !PageTransHuge(page
))
3828 lock_page_cgroup(pc
);
3831 if (!PageCgroupUsed(pc
) || pc
->mem_cgroup
!= from
)
3834 move_lock_mem_cgroup(from
, &flags
);
3836 if (!anon
&& page_mapped(page
))
3837 mem_cgroup_move_account_page_stat(from
, to
, nr_pages
,
3838 MEM_CGROUP_STAT_FILE_MAPPED
);
3840 if (PageWriteback(page
))
3841 mem_cgroup_move_account_page_stat(from
, to
, nr_pages
,
3842 MEM_CGROUP_STAT_WRITEBACK
);
3844 mem_cgroup_charge_statistics(from
, page
, anon
, -nr_pages
);
3846 /* caller should have done css_get */
3847 pc
->mem_cgroup
= to
;
3848 mem_cgroup_charge_statistics(to
, page
, anon
, nr_pages
);
3849 move_unlock_mem_cgroup(from
, &flags
);
3852 unlock_page_cgroup(pc
);
3856 memcg_check_events(to
, page
);
3857 memcg_check_events(from
, page
);
3863 * mem_cgroup_move_parent - moves page to the parent group
3864 * @page: the page to move
3865 * @pc: page_cgroup of the page
3866 * @child: page's cgroup
3868 * move charges to its parent or the root cgroup if the group has no
3869 * parent (aka use_hierarchy==0).
3870 * Although this might fail (get_page_unless_zero, isolate_lru_page or
3871 * mem_cgroup_move_account fails) the failure is always temporary and
3872 * it signals a race with a page removal/uncharge or migration. In the
3873 * first case the page is on the way out and it will vanish from the LRU
3874 * on the next attempt and the call should be retried later.
3875 * Isolation from the LRU fails only if page has been isolated from
3876 * the LRU since we looked at it and that usually means either global
3877 * reclaim or migration going on. The page will either get back to the
3879 * Finaly mem_cgroup_move_account fails only if the page got uncharged
3880 * (!PageCgroupUsed) or moved to a different group. The page will
3881 * disappear in the next attempt.
3883 static int mem_cgroup_move_parent(struct page
*page
,
3884 struct page_cgroup
*pc
,
3885 struct mem_cgroup
*child
)
3887 struct mem_cgroup
*parent
;
3888 unsigned int nr_pages
;
3889 unsigned long uninitialized_var(flags
);
3892 VM_BUG_ON(mem_cgroup_is_root(child
));
3895 if (!get_page_unless_zero(page
))
3897 if (isolate_lru_page(page
))
3900 nr_pages
= hpage_nr_pages(page
);
3902 parent
= parent_mem_cgroup(child
);
3904 * If no parent, move charges to root cgroup.
3907 parent
= root_mem_cgroup
;
3910 VM_BUG_ON(!PageTransHuge(page
));
3911 flags
= compound_lock_irqsave(page
);
3914 ret
= mem_cgroup_move_account(page
, nr_pages
,
3917 __mem_cgroup_cancel_local_charge(child
, nr_pages
);
3920 compound_unlock_irqrestore(page
, flags
);
3921 putback_lru_page(page
);
3929 * Charge the memory controller for page usage.
3931 * 0 if the charge was successful
3932 * < 0 if the cgroup is over its limit
3934 static int mem_cgroup_charge_common(struct page
*page
, struct mm_struct
*mm
,
3935 gfp_t gfp_mask
, enum charge_type ctype
)
3937 struct mem_cgroup
*memcg
= NULL
;
3938 unsigned int nr_pages
= 1;
3942 if (PageTransHuge(page
)) {
3943 nr_pages
<<= compound_order(page
);
3944 VM_BUG_ON(!PageTransHuge(page
));
3946 * Never OOM-kill a process for a huge page. The
3947 * fault handler will fall back to regular pages.
3952 ret
= __mem_cgroup_try_charge(mm
, gfp_mask
, nr_pages
, &memcg
, oom
);
3955 __mem_cgroup_commit_charge(memcg
, page
, nr_pages
, ctype
, false);
3959 int mem_cgroup_newpage_charge(struct page
*page
,
3960 struct mm_struct
*mm
, gfp_t gfp_mask
)
3962 if (mem_cgroup_disabled())
3964 VM_BUG_ON(page_mapped(page
));
3965 VM_BUG_ON(page
->mapping
&& !PageAnon(page
));
3967 return mem_cgroup_charge_common(page
, mm
, gfp_mask
,
3968 MEM_CGROUP_CHARGE_TYPE_ANON
);
3972 * While swap-in, try_charge -> commit or cancel, the page is locked.
3973 * And when try_charge() successfully returns, one refcnt to memcg without
3974 * struct page_cgroup is acquired. This refcnt will be consumed by
3975 * "commit()" or removed by "cancel()"
3977 static int __mem_cgroup_try_charge_swapin(struct mm_struct
*mm
,
3980 struct mem_cgroup
**memcgp
)
3982 struct mem_cgroup
*memcg
;
3983 struct page_cgroup
*pc
;
3986 pc
= lookup_page_cgroup(page
);
3988 * Every swap fault against a single page tries to charge the
3989 * page, bail as early as possible. shmem_unuse() encounters
3990 * already charged pages, too. The USED bit is protected by
3991 * the page lock, which serializes swap cache removal, which
3992 * in turn serializes uncharging.
3994 if (PageCgroupUsed(pc
))
3996 if (!do_swap_account
)
3998 memcg
= try_get_mem_cgroup_from_page(page
);
4002 ret
= __mem_cgroup_try_charge(NULL
, mask
, 1, memcgp
, true);
4003 css_put(&memcg
->css
);
4008 ret
= __mem_cgroup_try_charge(mm
, mask
, 1, memcgp
, true);
4014 int mem_cgroup_try_charge_swapin(struct mm_struct
*mm
, struct page
*page
,
4015 gfp_t gfp_mask
, struct mem_cgroup
**memcgp
)
4018 if (mem_cgroup_disabled())
4021 * A racing thread's fault, or swapoff, may have already
4022 * updated the pte, and even removed page from swap cache: in
4023 * those cases unuse_pte()'s pte_same() test will fail; but
4024 * there's also a KSM case which does need to charge the page.
4026 if (!PageSwapCache(page
)) {
4029 ret
= __mem_cgroup_try_charge(mm
, gfp_mask
, 1, memcgp
, true);
4034 return __mem_cgroup_try_charge_swapin(mm
, page
, gfp_mask
, memcgp
);
4037 void mem_cgroup_cancel_charge_swapin(struct mem_cgroup
*memcg
)
4039 if (mem_cgroup_disabled())
4043 __mem_cgroup_cancel_charge(memcg
, 1);
4047 __mem_cgroup_commit_charge_swapin(struct page
*page
, struct mem_cgroup
*memcg
,
4048 enum charge_type ctype
)
4050 if (mem_cgroup_disabled())
4055 __mem_cgroup_commit_charge(memcg
, page
, 1, ctype
, true);
4057 * Now swap is on-memory. This means this page may be
4058 * counted both as mem and swap....double count.
4059 * Fix it by uncharging from memsw. Basically, this SwapCache is stable
4060 * under lock_page(). But in do_swap_page()::memory.c, reuse_swap_page()
4061 * may call delete_from_swap_cache() before reach here.
4063 if (do_swap_account
&& PageSwapCache(page
)) {
4064 swp_entry_t ent
= {.val
= page_private(page
)};
4065 mem_cgroup_uncharge_swap(ent
);
4069 void mem_cgroup_commit_charge_swapin(struct page
*page
,
4070 struct mem_cgroup
*memcg
)
4072 __mem_cgroup_commit_charge_swapin(page
, memcg
,
4073 MEM_CGROUP_CHARGE_TYPE_ANON
);
4076 int mem_cgroup_cache_charge(struct page
*page
, struct mm_struct
*mm
,
4079 struct mem_cgroup
*memcg
= NULL
;
4080 enum charge_type type
= MEM_CGROUP_CHARGE_TYPE_CACHE
;
4083 if (mem_cgroup_disabled())
4085 if (PageCompound(page
))
4088 if (!PageSwapCache(page
))
4089 ret
= mem_cgroup_charge_common(page
, mm
, gfp_mask
, type
);
4090 else { /* page is swapcache/shmem */
4091 ret
= __mem_cgroup_try_charge_swapin(mm
, page
,
4094 __mem_cgroup_commit_charge_swapin(page
, memcg
, type
);
4099 static void mem_cgroup_do_uncharge(struct mem_cgroup
*memcg
,
4100 unsigned int nr_pages
,
4101 const enum charge_type ctype
)
4103 struct memcg_batch_info
*batch
= NULL
;
4104 bool uncharge_memsw
= true;
4106 /* If swapout, usage of swap doesn't decrease */
4107 if (!do_swap_account
|| ctype
== MEM_CGROUP_CHARGE_TYPE_SWAPOUT
)
4108 uncharge_memsw
= false;
4110 batch
= ¤t
->memcg_batch
;
4112 * In usual, we do css_get() when we remember memcg pointer.
4113 * But in this case, we keep res->usage until end of a series of
4114 * uncharges. Then, it's ok to ignore memcg's refcnt.
4117 batch
->memcg
= memcg
;
4119 * do_batch > 0 when unmapping pages or inode invalidate/truncate.
4120 * In those cases, all pages freed continuously can be expected to be in
4121 * the same cgroup and we have chance to coalesce uncharges.
4122 * But we do uncharge one by one if this is killed by OOM(TIF_MEMDIE)
4123 * because we want to do uncharge as soon as possible.
4126 if (!batch
->do_batch
|| test_thread_flag(TIF_MEMDIE
))
4127 goto direct_uncharge
;
4130 goto direct_uncharge
;
4133 * In typical case, batch->memcg == mem. This means we can
4134 * merge a series of uncharges to an uncharge of res_counter.
4135 * If not, we uncharge res_counter ony by one.
4137 if (batch
->memcg
!= memcg
)
4138 goto direct_uncharge
;
4139 /* remember freed charge and uncharge it later */
4142 batch
->memsw_nr_pages
++;
4145 res_counter_uncharge(&memcg
->res
, nr_pages
* PAGE_SIZE
);
4147 res_counter_uncharge(&memcg
->memsw
, nr_pages
* PAGE_SIZE
);
4148 if (unlikely(batch
->memcg
!= memcg
))
4149 memcg_oom_recover(memcg
);
4153 * uncharge if !page_mapped(page)
4155 static struct mem_cgroup
*
4156 __mem_cgroup_uncharge_common(struct page
*page
, enum charge_type ctype
,
4159 struct mem_cgroup
*memcg
= NULL
;
4160 unsigned int nr_pages
= 1;
4161 struct page_cgroup
*pc
;
4164 if (mem_cgroup_disabled())
4167 if (PageTransHuge(page
)) {
4168 nr_pages
<<= compound_order(page
);
4169 VM_BUG_ON(!PageTransHuge(page
));
4172 * Check if our page_cgroup is valid
4174 pc
= lookup_page_cgroup(page
);
4175 if (unlikely(!PageCgroupUsed(pc
)))
4178 lock_page_cgroup(pc
);
4180 memcg
= pc
->mem_cgroup
;
4182 if (!PageCgroupUsed(pc
))
4185 anon
= PageAnon(page
);
4188 case MEM_CGROUP_CHARGE_TYPE_ANON
:
4190 * Generally PageAnon tells if it's the anon statistics to be
4191 * updated; but sometimes e.g. mem_cgroup_uncharge_page() is
4192 * used before page reached the stage of being marked PageAnon.
4196 case MEM_CGROUP_CHARGE_TYPE_DROP
:
4197 /* See mem_cgroup_prepare_migration() */
4198 if (page_mapped(page
))
4201 * Pages under migration may not be uncharged. But
4202 * end_migration() /must/ be the one uncharging the
4203 * unused post-migration page and so it has to call
4204 * here with the migration bit still set. See the
4205 * res_counter handling below.
4207 if (!end_migration
&& PageCgroupMigration(pc
))
4210 case MEM_CGROUP_CHARGE_TYPE_SWAPOUT
:
4211 if (!PageAnon(page
)) { /* Shared memory */
4212 if (page
->mapping
&& !page_is_file_cache(page
))
4214 } else if (page_mapped(page
)) /* Anon */
4221 mem_cgroup_charge_statistics(memcg
, page
, anon
, -nr_pages
);
4223 ClearPageCgroupUsed(pc
);
4225 * pc->mem_cgroup is not cleared here. It will be accessed when it's
4226 * freed from LRU. This is safe because uncharged page is expected not
4227 * to be reused (freed soon). Exception is SwapCache, it's handled by
4228 * special functions.
4231 unlock_page_cgroup(pc
);
4233 * even after unlock, we have memcg->res.usage here and this memcg
4234 * will never be freed, so it's safe to call css_get().
4236 memcg_check_events(memcg
, page
);
4237 if (do_swap_account
&& ctype
== MEM_CGROUP_CHARGE_TYPE_SWAPOUT
) {
4238 mem_cgroup_swap_statistics(memcg
, true);
4239 css_get(&memcg
->css
);
4242 * Migration does not charge the res_counter for the
4243 * replacement page, so leave it alone when phasing out the
4244 * page that is unused after the migration.
4246 if (!end_migration
&& !mem_cgroup_is_root(memcg
))
4247 mem_cgroup_do_uncharge(memcg
, nr_pages
, ctype
);
4252 unlock_page_cgroup(pc
);
4256 void mem_cgroup_uncharge_page(struct page
*page
)
4259 if (page_mapped(page
))
4261 VM_BUG_ON(page
->mapping
&& !PageAnon(page
));
4263 * If the page is in swap cache, uncharge should be deferred
4264 * to the swap path, which also properly accounts swap usage
4265 * and handles memcg lifetime.
4267 * Note that this check is not stable and reclaim may add the
4268 * page to swap cache at any time after this. However, if the
4269 * page is not in swap cache by the time page->mapcount hits
4270 * 0, there won't be any page table references to the swap
4271 * slot, and reclaim will free it and not actually write the
4274 if (PageSwapCache(page
))
4276 __mem_cgroup_uncharge_common(page
, MEM_CGROUP_CHARGE_TYPE_ANON
, false);
4279 void mem_cgroup_uncharge_cache_page(struct page
*page
)
4281 VM_BUG_ON(page_mapped(page
));
4282 VM_BUG_ON(page
->mapping
);
4283 __mem_cgroup_uncharge_common(page
, MEM_CGROUP_CHARGE_TYPE_CACHE
, false);
4287 * Batch_start/batch_end is called in unmap_page_range/invlidate/trucate.
4288 * In that cases, pages are freed continuously and we can expect pages
4289 * are in the same memcg. All these calls itself limits the number of
4290 * pages freed at once, then uncharge_start/end() is called properly.
4291 * This may be called prural(2) times in a context,
4294 void mem_cgroup_uncharge_start(void)
4296 current
->memcg_batch
.do_batch
++;
4297 /* We can do nest. */
4298 if (current
->memcg_batch
.do_batch
== 1) {
4299 current
->memcg_batch
.memcg
= NULL
;
4300 current
->memcg_batch
.nr_pages
= 0;
4301 current
->memcg_batch
.memsw_nr_pages
= 0;
4305 void mem_cgroup_uncharge_end(void)
4307 struct memcg_batch_info
*batch
= ¤t
->memcg_batch
;
4309 if (!batch
->do_batch
)
4313 if (batch
->do_batch
) /* If stacked, do nothing. */
4319 * This "batch->memcg" is valid without any css_get/put etc...
4320 * bacause we hide charges behind us.
4322 if (batch
->nr_pages
)
4323 res_counter_uncharge(&batch
->memcg
->res
,
4324 batch
->nr_pages
* PAGE_SIZE
);
4325 if (batch
->memsw_nr_pages
)
4326 res_counter_uncharge(&batch
->memcg
->memsw
,
4327 batch
->memsw_nr_pages
* PAGE_SIZE
);
4328 memcg_oom_recover(batch
->memcg
);
4329 /* forget this pointer (for sanity check) */
4330 batch
->memcg
= NULL
;
4335 * called after __delete_from_swap_cache() and drop "page" account.
4336 * memcg information is recorded to swap_cgroup of "ent"
4339 mem_cgroup_uncharge_swapcache(struct page
*page
, swp_entry_t ent
, bool swapout
)
4341 struct mem_cgroup
*memcg
;
4342 int ctype
= MEM_CGROUP_CHARGE_TYPE_SWAPOUT
;
4344 if (!swapout
) /* this was a swap cache but the swap is unused ! */
4345 ctype
= MEM_CGROUP_CHARGE_TYPE_DROP
;
4347 memcg
= __mem_cgroup_uncharge_common(page
, ctype
, false);
4350 * record memcg information, if swapout && memcg != NULL,
4351 * css_get() was called in uncharge().
4353 if (do_swap_account
&& swapout
&& memcg
)
4354 swap_cgroup_record(ent
, css_id(&memcg
->css
));
4358 #ifdef CONFIG_MEMCG_SWAP
4360 * called from swap_entry_free(). remove record in swap_cgroup and
4361 * uncharge "memsw" account.
4363 void mem_cgroup_uncharge_swap(swp_entry_t ent
)
4365 struct mem_cgroup
*memcg
;
4368 if (!do_swap_account
)
4371 id
= swap_cgroup_record(ent
, 0);
4373 memcg
= mem_cgroup_lookup(id
);
4376 * We uncharge this because swap is freed.
4377 * This memcg can be obsolete one. We avoid calling css_tryget
4379 if (!mem_cgroup_is_root(memcg
))
4380 res_counter_uncharge(&memcg
->memsw
, PAGE_SIZE
);
4381 mem_cgroup_swap_statistics(memcg
, false);
4382 css_put(&memcg
->css
);
4388 * mem_cgroup_move_swap_account - move swap charge and swap_cgroup's record.
4389 * @entry: swap entry to be moved
4390 * @from: mem_cgroup which the entry is moved from
4391 * @to: mem_cgroup which the entry is moved to
4393 * It succeeds only when the swap_cgroup's record for this entry is the same
4394 * as the mem_cgroup's id of @from.
4396 * Returns 0 on success, -EINVAL on failure.
4398 * The caller must have charged to @to, IOW, called res_counter_charge() about
4399 * both res and memsw, and called css_get().
4401 static int mem_cgroup_move_swap_account(swp_entry_t entry
,
4402 struct mem_cgroup
*from
, struct mem_cgroup
*to
)
4404 unsigned short old_id
, new_id
;
4406 old_id
= css_id(&from
->css
);
4407 new_id
= css_id(&to
->css
);
4409 if (swap_cgroup_cmpxchg(entry
, old_id
, new_id
) == old_id
) {
4410 mem_cgroup_swap_statistics(from
, false);
4411 mem_cgroup_swap_statistics(to
, true);
4413 * This function is only called from task migration context now.
4414 * It postpones res_counter and refcount handling till the end
4415 * of task migration(mem_cgroup_clear_mc()) for performance
4416 * improvement. But we cannot postpone css_get(to) because if
4417 * the process that has been moved to @to does swap-in, the
4418 * refcount of @to might be decreased to 0.
4420 * We are in attach() phase, so the cgroup is guaranteed to be
4421 * alive, so we can just call css_get().
4429 static inline int mem_cgroup_move_swap_account(swp_entry_t entry
,
4430 struct mem_cgroup
*from
, struct mem_cgroup
*to
)
4437 * Before starting migration, account PAGE_SIZE to mem_cgroup that the old
4440 void mem_cgroup_prepare_migration(struct page
*page
, struct page
*newpage
,
4441 struct mem_cgroup
**memcgp
)
4443 struct mem_cgroup
*memcg
= NULL
;
4444 unsigned int nr_pages
= 1;
4445 struct page_cgroup
*pc
;
4446 enum charge_type ctype
;
4450 if (mem_cgroup_disabled())
4453 if (PageTransHuge(page
))
4454 nr_pages
<<= compound_order(page
);
4456 pc
= lookup_page_cgroup(page
);
4457 lock_page_cgroup(pc
);
4458 if (PageCgroupUsed(pc
)) {
4459 memcg
= pc
->mem_cgroup
;
4460 css_get(&memcg
->css
);
4462 * At migrating an anonymous page, its mapcount goes down
4463 * to 0 and uncharge() will be called. But, even if it's fully
4464 * unmapped, migration may fail and this page has to be
4465 * charged again. We set MIGRATION flag here and delay uncharge
4466 * until end_migration() is called
4468 * Corner Case Thinking
4470 * When the old page was mapped as Anon and it's unmap-and-freed
4471 * while migration was ongoing.
4472 * If unmap finds the old page, uncharge() of it will be delayed
4473 * until end_migration(). If unmap finds a new page, it's
4474 * uncharged when it make mapcount to be 1->0. If unmap code
4475 * finds swap_migration_entry, the new page will not be mapped
4476 * and end_migration() will find it(mapcount==0).
4479 * When the old page was mapped but migraion fails, the kernel
4480 * remaps it. A charge for it is kept by MIGRATION flag even
4481 * if mapcount goes down to 0. We can do remap successfully
4482 * without charging it again.
4485 * The "old" page is under lock_page() until the end of
4486 * migration, so, the old page itself will not be swapped-out.
4487 * If the new page is swapped out before end_migraton, our
4488 * hook to usual swap-out path will catch the event.
4491 SetPageCgroupMigration(pc
);
4493 unlock_page_cgroup(pc
);
4495 * If the page is not charged at this point,
4503 * We charge new page before it's used/mapped. So, even if unlock_page()
4504 * is called before end_migration, we can catch all events on this new
4505 * page. In the case new page is migrated but not remapped, new page's
4506 * mapcount will be finally 0 and we call uncharge in end_migration().
4509 ctype
= MEM_CGROUP_CHARGE_TYPE_ANON
;
4511 ctype
= MEM_CGROUP_CHARGE_TYPE_CACHE
;
4513 * The page is committed to the memcg, but it's not actually
4514 * charged to the res_counter since we plan on replacing the
4515 * old one and only one page is going to be left afterwards.
4517 __mem_cgroup_commit_charge(memcg
, newpage
, nr_pages
, ctype
, false);
4520 /* remove redundant charge if migration failed*/
4521 void mem_cgroup_end_migration(struct mem_cgroup
*memcg
,
4522 struct page
*oldpage
, struct page
*newpage
, bool migration_ok
)
4524 struct page
*used
, *unused
;
4525 struct page_cgroup
*pc
;
4531 if (!migration_ok
) {
4538 anon
= PageAnon(used
);
4539 __mem_cgroup_uncharge_common(unused
,
4540 anon
? MEM_CGROUP_CHARGE_TYPE_ANON
4541 : MEM_CGROUP_CHARGE_TYPE_CACHE
,
4543 css_put(&memcg
->css
);
4545 * We disallowed uncharge of pages under migration because mapcount
4546 * of the page goes down to zero, temporarly.
4547 * Clear the flag and check the page should be charged.
4549 pc
= lookup_page_cgroup(oldpage
);
4550 lock_page_cgroup(pc
);
4551 ClearPageCgroupMigration(pc
);
4552 unlock_page_cgroup(pc
);
4555 * If a page is a file cache, radix-tree replacement is very atomic
4556 * and we can skip this check. When it was an Anon page, its mapcount
4557 * goes down to 0. But because we added MIGRATION flage, it's not
4558 * uncharged yet. There are several case but page->mapcount check
4559 * and USED bit check in mem_cgroup_uncharge_page() will do enough
4560 * check. (see prepare_charge() also)
4563 mem_cgroup_uncharge_page(used
);
4567 * At replace page cache, newpage is not under any memcg but it's on
4568 * LRU. So, this function doesn't touch res_counter but handles LRU
4569 * in correct way. Both pages are locked so we cannot race with uncharge.
4571 void mem_cgroup_replace_page_cache(struct page
*oldpage
,
4572 struct page
*newpage
)
4574 struct mem_cgroup
*memcg
= NULL
;
4575 struct page_cgroup
*pc
;
4576 enum charge_type type
= MEM_CGROUP_CHARGE_TYPE_CACHE
;
4578 if (mem_cgroup_disabled())
4581 pc
= lookup_page_cgroup(oldpage
);
4582 /* fix accounting on old pages */
4583 lock_page_cgroup(pc
);
4584 if (PageCgroupUsed(pc
)) {
4585 memcg
= pc
->mem_cgroup
;
4586 mem_cgroup_charge_statistics(memcg
, oldpage
, false, -1);
4587 ClearPageCgroupUsed(pc
);
4589 unlock_page_cgroup(pc
);
4592 * When called from shmem_replace_page(), in some cases the
4593 * oldpage has already been charged, and in some cases not.
4598 * Even if newpage->mapping was NULL before starting replacement,
4599 * the newpage may be on LRU(or pagevec for LRU) already. We lock
4600 * LRU while we overwrite pc->mem_cgroup.
4602 __mem_cgroup_commit_charge(memcg
, newpage
, 1, type
, true);
4605 #ifdef CONFIG_DEBUG_VM
4606 static struct page_cgroup
*lookup_page_cgroup_used(struct page
*page
)
4608 struct page_cgroup
*pc
;
4610 pc
= lookup_page_cgroup(page
);
4612 * Can be NULL while feeding pages into the page allocator for
4613 * the first time, i.e. during boot or memory hotplug;
4614 * or when mem_cgroup_disabled().
4616 if (likely(pc
) && PageCgroupUsed(pc
))
4621 bool mem_cgroup_bad_page_check(struct page
*page
)
4623 if (mem_cgroup_disabled())
4626 return lookup_page_cgroup_used(page
) != NULL
;
4629 void mem_cgroup_print_bad_page(struct page
*page
)
4631 struct page_cgroup
*pc
;
4633 pc
= lookup_page_cgroup_used(page
);
4635 pr_alert("pc:%p pc->flags:%lx pc->mem_cgroup:%p\n",
4636 pc
, pc
->flags
, pc
->mem_cgroup
);
4641 static int mem_cgroup_resize_limit(struct mem_cgroup
*memcg
,
4642 unsigned long long val
)
4645 u64 memswlimit
, memlimit
;
4647 int children
= mem_cgroup_count_children(memcg
);
4648 u64 curusage
, oldusage
;
4652 * For keeping hierarchical_reclaim simple, how long we should retry
4653 * is depends on callers. We set our retry-count to be function
4654 * of # of children which we should visit in this loop.
4656 retry_count
= MEM_CGROUP_RECLAIM_RETRIES
* children
;
4658 oldusage
= res_counter_read_u64(&memcg
->res
, RES_USAGE
);
4661 while (retry_count
) {
4662 if (signal_pending(current
)) {
4667 * Rather than hide all in some function, I do this in
4668 * open coded manner. You see what this really does.
4669 * We have to guarantee memcg->res.limit <= memcg->memsw.limit.
4671 mutex_lock(&set_limit_mutex
);
4672 memswlimit
= res_counter_read_u64(&memcg
->memsw
, RES_LIMIT
);
4673 if (memswlimit
< val
) {
4675 mutex_unlock(&set_limit_mutex
);
4679 memlimit
= res_counter_read_u64(&memcg
->res
, RES_LIMIT
);
4683 ret
= res_counter_set_limit(&memcg
->res
, val
);
4685 if (memswlimit
== val
)
4686 memcg
->memsw_is_minimum
= true;
4688 memcg
->memsw_is_minimum
= false;
4690 mutex_unlock(&set_limit_mutex
);
4695 mem_cgroup_reclaim(memcg
, GFP_KERNEL
,
4696 MEM_CGROUP_RECLAIM_SHRINK
);
4697 curusage
= res_counter_read_u64(&memcg
->res
, RES_USAGE
);
4698 /* Usage is reduced ? */
4699 if (curusage
>= oldusage
)
4702 oldusage
= curusage
;
4704 if (!ret
&& enlarge
)
4705 memcg_oom_recover(memcg
);
4710 static int mem_cgroup_resize_memsw_limit(struct mem_cgroup
*memcg
,
4711 unsigned long long val
)
4714 u64 memlimit
, memswlimit
, oldusage
, curusage
;
4715 int children
= mem_cgroup_count_children(memcg
);
4719 /* see mem_cgroup_resize_res_limit */
4720 retry_count
= children
* MEM_CGROUP_RECLAIM_RETRIES
;
4721 oldusage
= res_counter_read_u64(&memcg
->memsw
, RES_USAGE
);
4722 while (retry_count
) {
4723 if (signal_pending(current
)) {
4728 * Rather than hide all in some function, I do this in
4729 * open coded manner. You see what this really does.
4730 * We have to guarantee memcg->res.limit <= memcg->memsw.limit.
4732 mutex_lock(&set_limit_mutex
);
4733 memlimit
= res_counter_read_u64(&memcg
->res
, RES_LIMIT
);
4734 if (memlimit
> val
) {
4736 mutex_unlock(&set_limit_mutex
);
4739 memswlimit
= res_counter_read_u64(&memcg
->memsw
, RES_LIMIT
);
4740 if (memswlimit
< val
)
4742 ret
= res_counter_set_limit(&memcg
->memsw
, val
);
4744 if (memlimit
== val
)
4745 memcg
->memsw_is_minimum
= true;
4747 memcg
->memsw_is_minimum
= false;
4749 mutex_unlock(&set_limit_mutex
);
4754 mem_cgroup_reclaim(memcg
, GFP_KERNEL
,
4755 MEM_CGROUP_RECLAIM_NOSWAP
|
4756 MEM_CGROUP_RECLAIM_SHRINK
);
4757 curusage
= res_counter_read_u64(&memcg
->memsw
, RES_USAGE
);
4758 /* Usage is reduced ? */
4759 if (curusage
>= oldusage
)
4762 oldusage
= curusage
;
4764 if (!ret
&& enlarge
)
4765 memcg_oom_recover(memcg
);
4769 unsigned long mem_cgroup_soft_limit_reclaim(struct zone
*zone
, int order
,
4771 unsigned long *total_scanned
)
4773 unsigned long nr_reclaimed
= 0;
4774 struct mem_cgroup_per_zone
*mz
, *next_mz
= NULL
;
4775 unsigned long reclaimed
;
4777 struct mem_cgroup_tree_per_zone
*mctz
;
4778 unsigned long long excess
;
4779 unsigned long nr_scanned
;
4784 mctz
= soft_limit_tree_node_zone(zone_to_nid(zone
), zone_idx(zone
));
4786 * This loop can run a while, specially if mem_cgroup's continuously
4787 * keep exceeding their soft limit and putting the system under
4794 mz
= mem_cgroup_largest_soft_limit_node(mctz
);
4799 reclaimed
= mem_cgroup_soft_reclaim(mz
->memcg
, zone
,
4800 gfp_mask
, &nr_scanned
);
4801 nr_reclaimed
+= reclaimed
;
4802 *total_scanned
+= nr_scanned
;
4803 spin_lock(&mctz
->lock
);
4806 * If we failed to reclaim anything from this memory cgroup
4807 * it is time to move on to the next cgroup
4813 * Loop until we find yet another one.
4815 * By the time we get the soft_limit lock
4816 * again, someone might have aded the
4817 * group back on the RB tree. Iterate to
4818 * make sure we get a different mem.
4819 * mem_cgroup_largest_soft_limit_node returns
4820 * NULL if no other cgroup is present on
4824 __mem_cgroup_largest_soft_limit_node(mctz
);
4826 css_put(&next_mz
->memcg
->css
);
4827 else /* next_mz == NULL or other memcg */
4831 __mem_cgroup_remove_exceeded(mz
->memcg
, mz
, mctz
);
4832 excess
= res_counter_soft_limit_excess(&mz
->memcg
->res
);
4834 * One school of thought says that we should not add
4835 * back the node to the tree if reclaim returns 0.
4836 * But our reclaim could return 0, simply because due
4837 * to priority we are exposing a smaller subset of
4838 * memory to reclaim from. Consider this as a longer
4841 /* If excess == 0, no tree ops */
4842 __mem_cgroup_insert_exceeded(mz
->memcg
, mz
, mctz
, excess
);
4843 spin_unlock(&mctz
->lock
);
4844 css_put(&mz
->memcg
->css
);
4847 * Could not reclaim anything and there are no more
4848 * mem cgroups to try or we seem to be looping without
4849 * reclaiming anything.
4851 if (!nr_reclaimed
&&
4853 loop
> MEM_CGROUP_MAX_SOFT_LIMIT_RECLAIM_LOOPS
))
4855 } while (!nr_reclaimed
);
4857 css_put(&next_mz
->memcg
->css
);
4858 return nr_reclaimed
;
4862 * mem_cgroup_force_empty_list - clears LRU of a group
4863 * @memcg: group to clear
4866 * @lru: lru to to clear
4868 * Traverse a specified page_cgroup list and try to drop them all. This doesn't
4869 * reclaim the pages page themselves - pages are moved to the parent (or root)
4872 static void mem_cgroup_force_empty_list(struct mem_cgroup
*memcg
,
4873 int node
, int zid
, enum lru_list lru
)
4875 struct lruvec
*lruvec
;
4876 unsigned long flags
;
4877 struct list_head
*list
;
4881 zone
= &NODE_DATA(node
)->node_zones
[zid
];
4882 lruvec
= mem_cgroup_zone_lruvec(zone
, memcg
);
4883 list
= &lruvec
->lists
[lru
];
4887 struct page_cgroup
*pc
;
4890 spin_lock_irqsave(&zone
->lru_lock
, flags
);
4891 if (list_empty(list
)) {
4892 spin_unlock_irqrestore(&zone
->lru_lock
, flags
);
4895 page
= list_entry(list
->prev
, struct page
, lru
);
4897 list_move(&page
->lru
, list
);
4899 spin_unlock_irqrestore(&zone
->lru_lock
, flags
);
4902 spin_unlock_irqrestore(&zone
->lru_lock
, flags
);
4904 pc
= lookup_page_cgroup(page
);
4906 if (mem_cgroup_move_parent(page
, pc
, memcg
)) {
4907 /* found lock contention or "pc" is obsolete. */
4912 } while (!list_empty(list
));
4916 * make mem_cgroup's charge to be 0 if there is no task by moving
4917 * all the charges and pages to the parent.
4918 * This enables deleting this mem_cgroup.
4920 * Caller is responsible for holding css reference on the memcg.
4922 static void mem_cgroup_reparent_charges(struct mem_cgroup
*memcg
)
4928 /* This is for making all *used* pages to be on LRU. */
4929 lru_add_drain_all();
4930 drain_all_stock_sync(memcg
);
4931 mem_cgroup_start_move(memcg
);
4932 for_each_node_state(node
, N_MEMORY
) {
4933 for (zid
= 0; zid
< MAX_NR_ZONES
; zid
++) {
4936 mem_cgroup_force_empty_list(memcg
,
4941 mem_cgroup_end_move(memcg
);
4942 memcg_oom_recover(memcg
);
4946 * Kernel memory may not necessarily be trackable to a specific
4947 * process. So they are not migrated, and therefore we can't
4948 * expect their value to drop to 0 here.
4949 * Having res filled up with kmem only is enough.
4951 * This is a safety check because mem_cgroup_force_empty_list
4952 * could have raced with mem_cgroup_replace_page_cache callers
4953 * so the lru seemed empty but the page could have been added
4954 * right after the check. RES_USAGE should be safe as we always
4955 * charge before adding to the LRU.
4957 usage
= res_counter_read_u64(&memcg
->res
, RES_USAGE
) -
4958 res_counter_read_u64(&memcg
->kmem
, RES_USAGE
);
4959 } while (usage
> 0);
4963 * This mainly exists for tests during the setting of set of use_hierarchy.
4964 * Since this is the very setting we are changing, the current hierarchy value
4967 static inline bool __memcg_has_children(struct mem_cgroup
*memcg
)
4969 struct cgroup_subsys_state
*pos
;
4971 /* bounce at first found */
4972 css_for_each_child(pos
, &memcg
->css
)
4978 * Must be called with memcg_create_mutex held, unless the cgroup is guaranteed
4979 * to be already dead (as in mem_cgroup_force_empty, for instance). This is
4980 * from mem_cgroup_count_children(), in the sense that we don't really care how
4981 * many children we have; we only need to know if we have any. It also counts
4982 * any memcg without hierarchy as infertile.
4984 static inline bool memcg_has_children(struct mem_cgroup
*memcg
)
4986 return memcg
->use_hierarchy
&& __memcg_has_children(memcg
);
4990 * Reclaims as many pages from the given memcg as possible and moves
4991 * the rest to the parent.
4993 * Caller is responsible for holding css reference for memcg.
4995 static int mem_cgroup_force_empty(struct mem_cgroup
*memcg
)
4997 int nr_retries
= MEM_CGROUP_RECLAIM_RETRIES
;
4998 struct cgroup
*cgrp
= memcg
->css
.cgroup
;
5000 /* returns EBUSY if there is a task or if we come here twice. */
5001 if (cgroup_task_count(cgrp
) || !list_empty(&cgrp
->children
))
5004 /* we call try-to-free pages for make this cgroup empty */
5005 lru_add_drain_all();
5006 /* try to free all pages in this cgroup */
5007 while (nr_retries
&& res_counter_read_u64(&memcg
->res
, RES_USAGE
) > 0) {
5010 if (signal_pending(current
))
5013 progress
= try_to_free_mem_cgroup_pages(memcg
, GFP_KERNEL
,
5017 /* maybe some writeback is necessary */
5018 congestion_wait(BLK_RW_ASYNC
, HZ
/10);
5023 mem_cgroup_reparent_charges(memcg
);
5028 static int mem_cgroup_force_empty_write(struct cgroup_subsys_state
*css
,
5031 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
5033 if (mem_cgroup_is_root(memcg
))
5035 return mem_cgroup_force_empty(memcg
);
5038 static u64
mem_cgroup_hierarchy_read(struct cgroup_subsys_state
*css
,
5041 return mem_cgroup_from_css(css
)->use_hierarchy
;
5044 static int mem_cgroup_hierarchy_write(struct cgroup_subsys_state
*css
,
5045 struct cftype
*cft
, u64 val
)
5048 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
5049 struct mem_cgroup
*parent_memcg
= mem_cgroup_from_css(css_parent(&memcg
->css
));
5051 mutex_lock(&memcg_create_mutex
);
5053 if (memcg
->use_hierarchy
== val
)
5057 * If parent's use_hierarchy is set, we can't make any modifications
5058 * in the child subtrees. If it is unset, then the change can
5059 * occur, provided the current cgroup has no children.
5061 * For the root cgroup, parent_mem is NULL, we allow value to be
5062 * set if there are no children.
5064 if ((!parent_memcg
|| !parent_memcg
->use_hierarchy
) &&
5065 (val
== 1 || val
== 0)) {
5066 if (!__memcg_has_children(memcg
))
5067 memcg
->use_hierarchy
= val
;
5074 mutex_unlock(&memcg_create_mutex
);
5080 static unsigned long mem_cgroup_recursive_stat(struct mem_cgroup
*memcg
,
5081 enum mem_cgroup_stat_index idx
)
5083 struct mem_cgroup
*iter
;
5086 /* Per-cpu values can be negative, use a signed accumulator */
5087 for_each_mem_cgroup_tree(iter
, memcg
)
5088 val
+= mem_cgroup_read_stat(iter
, idx
);
5090 if (val
< 0) /* race ? */
5095 static inline u64
mem_cgroup_usage(struct mem_cgroup
*memcg
, bool swap
)
5099 if (!mem_cgroup_is_root(memcg
)) {
5101 return res_counter_read_u64(&memcg
->res
, RES_USAGE
);
5103 return res_counter_read_u64(&memcg
->memsw
, RES_USAGE
);
5107 * Transparent hugepages are still accounted for in MEM_CGROUP_STAT_RSS
5108 * as well as in MEM_CGROUP_STAT_RSS_HUGE.
5110 val
= mem_cgroup_recursive_stat(memcg
, MEM_CGROUP_STAT_CACHE
);
5111 val
+= mem_cgroup_recursive_stat(memcg
, MEM_CGROUP_STAT_RSS
);
5114 val
+= mem_cgroup_recursive_stat(memcg
, MEM_CGROUP_STAT_SWAP
);
5116 return val
<< PAGE_SHIFT
;
5119 static ssize_t
mem_cgroup_read(struct cgroup_subsys_state
*css
,
5120 struct cftype
*cft
, struct file
*file
,
5121 char __user
*buf
, size_t nbytes
, loff_t
*ppos
)
5123 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
5129 type
= MEMFILE_TYPE(cft
->private);
5130 name
= MEMFILE_ATTR(cft
->private);
5134 if (name
== RES_USAGE
)
5135 val
= mem_cgroup_usage(memcg
, false);
5137 val
= res_counter_read_u64(&memcg
->res
, name
);
5140 if (name
== RES_USAGE
)
5141 val
= mem_cgroup_usage(memcg
, true);
5143 val
= res_counter_read_u64(&memcg
->memsw
, name
);
5146 val
= res_counter_read_u64(&memcg
->kmem
, name
);
5152 len
= scnprintf(str
, sizeof(str
), "%llu\n", (unsigned long long)val
);
5153 return simple_read_from_buffer(buf
, nbytes
, ppos
, str
, len
);
5156 static int memcg_update_kmem_limit(struct cgroup_subsys_state
*css
, u64 val
)
5159 #ifdef CONFIG_MEMCG_KMEM
5160 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
5162 * For simplicity, we won't allow this to be disabled. It also can't
5163 * be changed if the cgroup has children already, or if tasks had
5166 * If tasks join before we set the limit, a person looking at
5167 * kmem.usage_in_bytes will have no way to determine when it took
5168 * place, which makes the value quite meaningless.
5170 * After it first became limited, changes in the value of the limit are
5171 * of course permitted.
5173 mutex_lock(&memcg_create_mutex
);
5174 mutex_lock(&set_limit_mutex
);
5175 if (!memcg
->kmem_account_flags
&& val
!= RES_COUNTER_MAX
) {
5176 if (cgroup_task_count(css
->cgroup
) || memcg_has_children(memcg
)) {
5180 ret
= res_counter_set_limit(&memcg
->kmem
, val
);
5183 ret
= memcg_update_cache_sizes(memcg
);
5185 res_counter_set_limit(&memcg
->kmem
, RES_COUNTER_MAX
);
5188 static_key_slow_inc(&memcg_kmem_enabled_key
);
5190 * setting the active bit after the inc will guarantee no one
5191 * starts accounting before all call sites are patched
5193 memcg_kmem_set_active(memcg
);
5195 ret
= res_counter_set_limit(&memcg
->kmem
, val
);
5197 mutex_unlock(&set_limit_mutex
);
5198 mutex_unlock(&memcg_create_mutex
);
5203 #ifdef CONFIG_MEMCG_KMEM
5204 static int memcg_propagate_kmem(struct mem_cgroup
*memcg
)
5207 struct mem_cgroup
*parent
= parent_mem_cgroup(memcg
);
5211 memcg
->kmem_account_flags
= parent
->kmem_account_flags
;
5213 * When that happen, we need to disable the static branch only on those
5214 * memcgs that enabled it. To achieve this, we would be forced to
5215 * complicate the code by keeping track of which memcgs were the ones
5216 * that actually enabled limits, and which ones got it from its
5219 * It is a lot simpler just to do static_key_slow_inc() on every child
5220 * that is accounted.
5222 if (!memcg_kmem_is_active(memcg
))
5226 * __mem_cgroup_free() will issue static_key_slow_dec() because this
5227 * memcg is active already. If the later initialization fails then the
5228 * cgroup core triggers the cleanup so we do not have to do it here.
5230 static_key_slow_inc(&memcg_kmem_enabled_key
);
5232 mutex_lock(&set_limit_mutex
);
5233 memcg_stop_kmem_account();
5234 ret
= memcg_update_cache_sizes(memcg
);
5235 memcg_resume_kmem_account();
5236 mutex_unlock(&set_limit_mutex
);
5240 #endif /* CONFIG_MEMCG_KMEM */
5243 * The user of this function is...
5246 static int mem_cgroup_write(struct cgroup_subsys_state
*css
, struct cftype
*cft
,
5249 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
5252 unsigned long long val
;
5255 type
= MEMFILE_TYPE(cft
->private);
5256 name
= MEMFILE_ATTR(cft
->private);
5260 if (mem_cgroup_is_root(memcg
)) { /* Can't set limit on root */
5264 /* This function does all necessary parse...reuse it */
5265 ret
= res_counter_memparse_write_strategy(buffer
, &val
);
5269 ret
= mem_cgroup_resize_limit(memcg
, val
);
5270 else if (type
== _MEMSWAP
)
5271 ret
= mem_cgroup_resize_memsw_limit(memcg
, val
);
5272 else if (type
== _KMEM
)
5273 ret
= memcg_update_kmem_limit(css
, val
);
5277 case RES_SOFT_LIMIT
:
5278 ret
= res_counter_memparse_write_strategy(buffer
, &val
);
5282 * For memsw, soft limits are hard to implement in terms
5283 * of semantics, for now, we support soft limits for
5284 * control without swap
5287 ret
= res_counter_set_soft_limit(&memcg
->res
, val
);
5292 ret
= -EINVAL
; /* should be BUG() ? */
5298 static void memcg_get_hierarchical_limit(struct mem_cgroup
*memcg
,
5299 unsigned long long *mem_limit
, unsigned long long *memsw_limit
)
5301 unsigned long long min_limit
, min_memsw_limit
, tmp
;
5303 min_limit
= res_counter_read_u64(&memcg
->res
, RES_LIMIT
);
5304 min_memsw_limit
= res_counter_read_u64(&memcg
->memsw
, RES_LIMIT
);
5305 if (!memcg
->use_hierarchy
)
5308 while (css_parent(&memcg
->css
)) {
5309 memcg
= mem_cgroup_from_css(css_parent(&memcg
->css
));
5310 if (!memcg
->use_hierarchy
)
5312 tmp
= res_counter_read_u64(&memcg
->res
, RES_LIMIT
);
5313 min_limit
= min(min_limit
, tmp
);
5314 tmp
= res_counter_read_u64(&memcg
->memsw
, RES_LIMIT
);
5315 min_memsw_limit
= min(min_memsw_limit
, tmp
);
5318 *mem_limit
= min_limit
;
5319 *memsw_limit
= min_memsw_limit
;
5322 static int mem_cgroup_reset(struct cgroup_subsys_state
*css
, unsigned int event
)
5324 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
5328 type
= MEMFILE_TYPE(event
);
5329 name
= MEMFILE_ATTR(event
);
5334 res_counter_reset_max(&memcg
->res
);
5335 else if (type
== _MEMSWAP
)
5336 res_counter_reset_max(&memcg
->memsw
);
5337 else if (type
== _KMEM
)
5338 res_counter_reset_max(&memcg
->kmem
);
5344 res_counter_reset_failcnt(&memcg
->res
);
5345 else if (type
== _MEMSWAP
)
5346 res_counter_reset_failcnt(&memcg
->memsw
);
5347 else if (type
== _KMEM
)
5348 res_counter_reset_failcnt(&memcg
->kmem
);
5357 static u64
mem_cgroup_move_charge_read(struct cgroup_subsys_state
*css
,
5360 return mem_cgroup_from_css(css
)->move_charge_at_immigrate
;
5364 static int mem_cgroup_move_charge_write(struct cgroup_subsys_state
*css
,
5365 struct cftype
*cft
, u64 val
)
5367 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
5369 if (val
>= (1 << NR_MOVE_TYPE
))
5373 * No kind of locking is needed in here, because ->can_attach() will
5374 * check this value once in the beginning of the process, and then carry
5375 * on with stale data. This means that changes to this value will only
5376 * affect task migrations starting after the change.
5378 memcg
->move_charge_at_immigrate
= val
;
5382 static int mem_cgroup_move_charge_write(struct cgroup_subsys_state
*css
,
5383 struct cftype
*cft
, u64 val
)
5390 static int memcg_numa_stat_show(struct cgroup_subsys_state
*css
,
5391 struct cftype
*cft
, struct seq_file
*m
)
5394 unsigned long total_nr
, file_nr
, anon_nr
, unevictable_nr
;
5395 unsigned long node_nr
;
5396 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
5398 total_nr
= mem_cgroup_nr_lru_pages(memcg
, LRU_ALL
);
5399 seq_printf(m
, "total=%lu", total_nr
);
5400 for_each_node_state(nid
, N_MEMORY
) {
5401 node_nr
= mem_cgroup_node_nr_lru_pages(memcg
, nid
, LRU_ALL
);
5402 seq_printf(m
, " N%d=%lu", nid
, node_nr
);
5406 file_nr
= mem_cgroup_nr_lru_pages(memcg
, LRU_ALL_FILE
);
5407 seq_printf(m
, "file=%lu", file_nr
);
5408 for_each_node_state(nid
, N_MEMORY
) {
5409 node_nr
= mem_cgroup_node_nr_lru_pages(memcg
, nid
,
5411 seq_printf(m
, " N%d=%lu", nid
, node_nr
);
5415 anon_nr
= mem_cgroup_nr_lru_pages(memcg
, LRU_ALL_ANON
);
5416 seq_printf(m
, "anon=%lu", anon_nr
);
5417 for_each_node_state(nid
, N_MEMORY
) {
5418 node_nr
= mem_cgroup_node_nr_lru_pages(memcg
, nid
,
5420 seq_printf(m
, " N%d=%lu", nid
, node_nr
);
5424 unevictable_nr
= mem_cgroup_nr_lru_pages(memcg
, BIT(LRU_UNEVICTABLE
));
5425 seq_printf(m
, "unevictable=%lu", unevictable_nr
);
5426 for_each_node_state(nid
, N_MEMORY
) {
5427 node_nr
= mem_cgroup_node_nr_lru_pages(memcg
, nid
,
5428 BIT(LRU_UNEVICTABLE
));
5429 seq_printf(m
, " N%d=%lu", nid
, node_nr
);
5434 #endif /* CONFIG_NUMA */
5436 static inline void mem_cgroup_lru_names_not_uptodate(void)
5438 BUILD_BUG_ON(ARRAY_SIZE(mem_cgroup_lru_names
) != NR_LRU_LISTS
);
5441 static int memcg_stat_show(struct cgroup_subsys_state
*css
, struct cftype
*cft
,
5444 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
5445 struct mem_cgroup
*mi
;
5448 for (i
= 0; i
< MEM_CGROUP_STAT_NSTATS
; i
++) {
5449 if (i
== MEM_CGROUP_STAT_SWAP
&& !do_swap_account
)
5451 seq_printf(m
, "%s %ld\n", mem_cgroup_stat_names
[i
],
5452 mem_cgroup_read_stat(memcg
, i
) * PAGE_SIZE
);
5455 for (i
= 0; i
< MEM_CGROUP_EVENTS_NSTATS
; i
++)
5456 seq_printf(m
, "%s %lu\n", mem_cgroup_events_names
[i
],
5457 mem_cgroup_read_events(memcg
, i
));
5459 for (i
= 0; i
< NR_LRU_LISTS
; i
++)
5460 seq_printf(m
, "%s %lu\n", mem_cgroup_lru_names
[i
],
5461 mem_cgroup_nr_lru_pages(memcg
, BIT(i
)) * PAGE_SIZE
);
5463 /* Hierarchical information */
5465 unsigned long long limit
, memsw_limit
;
5466 memcg_get_hierarchical_limit(memcg
, &limit
, &memsw_limit
);
5467 seq_printf(m
, "hierarchical_memory_limit %llu\n", limit
);
5468 if (do_swap_account
)
5469 seq_printf(m
, "hierarchical_memsw_limit %llu\n",
5473 for (i
= 0; i
< MEM_CGROUP_STAT_NSTATS
; i
++) {
5476 if (i
== MEM_CGROUP_STAT_SWAP
&& !do_swap_account
)
5478 for_each_mem_cgroup_tree(mi
, memcg
)
5479 val
+= mem_cgroup_read_stat(mi
, i
) * PAGE_SIZE
;
5480 seq_printf(m
, "total_%s %lld\n", mem_cgroup_stat_names
[i
], val
);
5483 for (i
= 0; i
< MEM_CGROUP_EVENTS_NSTATS
; i
++) {
5484 unsigned long long val
= 0;
5486 for_each_mem_cgroup_tree(mi
, memcg
)
5487 val
+= mem_cgroup_read_events(mi
, i
);
5488 seq_printf(m
, "total_%s %llu\n",
5489 mem_cgroup_events_names
[i
], val
);
5492 for (i
= 0; i
< NR_LRU_LISTS
; i
++) {
5493 unsigned long long val
= 0;
5495 for_each_mem_cgroup_tree(mi
, memcg
)
5496 val
+= mem_cgroup_nr_lru_pages(mi
, BIT(i
)) * PAGE_SIZE
;
5497 seq_printf(m
, "total_%s %llu\n", mem_cgroup_lru_names
[i
], val
);
5500 #ifdef CONFIG_DEBUG_VM
5503 struct mem_cgroup_per_zone
*mz
;
5504 struct zone_reclaim_stat
*rstat
;
5505 unsigned long recent_rotated
[2] = {0, 0};
5506 unsigned long recent_scanned
[2] = {0, 0};
5508 for_each_online_node(nid
)
5509 for (zid
= 0; zid
< MAX_NR_ZONES
; zid
++) {
5510 mz
= mem_cgroup_zoneinfo(memcg
, nid
, zid
);
5511 rstat
= &mz
->lruvec
.reclaim_stat
;
5513 recent_rotated
[0] += rstat
->recent_rotated
[0];
5514 recent_rotated
[1] += rstat
->recent_rotated
[1];
5515 recent_scanned
[0] += rstat
->recent_scanned
[0];
5516 recent_scanned
[1] += rstat
->recent_scanned
[1];
5518 seq_printf(m
, "recent_rotated_anon %lu\n", recent_rotated
[0]);
5519 seq_printf(m
, "recent_rotated_file %lu\n", recent_rotated
[1]);
5520 seq_printf(m
, "recent_scanned_anon %lu\n", recent_scanned
[0]);
5521 seq_printf(m
, "recent_scanned_file %lu\n", recent_scanned
[1]);
5528 static u64
mem_cgroup_swappiness_read(struct cgroup_subsys_state
*css
,
5531 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
5533 return mem_cgroup_swappiness(memcg
);
5536 static int mem_cgroup_swappiness_write(struct cgroup_subsys_state
*css
,
5537 struct cftype
*cft
, u64 val
)
5539 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
5540 struct mem_cgroup
*parent
= mem_cgroup_from_css(css_parent(&memcg
->css
));
5542 if (val
> 100 || !parent
)
5545 mutex_lock(&memcg_create_mutex
);
5547 /* If under hierarchy, only empty-root can set this value */
5548 if ((parent
->use_hierarchy
) || memcg_has_children(memcg
)) {
5549 mutex_unlock(&memcg_create_mutex
);
5553 memcg
->swappiness
= val
;
5555 mutex_unlock(&memcg_create_mutex
);
5560 static void __mem_cgroup_threshold(struct mem_cgroup
*memcg
, bool swap
)
5562 struct mem_cgroup_threshold_ary
*t
;
5568 t
= rcu_dereference(memcg
->thresholds
.primary
);
5570 t
= rcu_dereference(memcg
->memsw_thresholds
.primary
);
5575 usage
= mem_cgroup_usage(memcg
, swap
);
5578 * current_threshold points to threshold just below or equal to usage.
5579 * If it's not true, a threshold was crossed after last
5580 * call of __mem_cgroup_threshold().
5582 i
= t
->current_threshold
;
5585 * Iterate backward over array of thresholds starting from
5586 * current_threshold and check if a threshold is crossed.
5587 * If none of thresholds below usage is crossed, we read
5588 * only one element of the array here.
5590 for (; i
>= 0 && unlikely(t
->entries
[i
].threshold
> usage
); i
--)
5591 eventfd_signal(t
->entries
[i
].eventfd
, 1);
5593 /* i = current_threshold + 1 */
5597 * Iterate forward over array of thresholds starting from
5598 * current_threshold+1 and check if a threshold is crossed.
5599 * If none of thresholds above usage is crossed, we read
5600 * only one element of the array here.
5602 for (; i
< t
->size
&& unlikely(t
->entries
[i
].threshold
<= usage
); i
++)
5603 eventfd_signal(t
->entries
[i
].eventfd
, 1);
5605 /* Update current_threshold */
5606 t
->current_threshold
= i
- 1;
5611 static void mem_cgroup_threshold(struct mem_cgroup
*memcg
)
5614 __mem_cgroup_threshold(memcg
, false);
5615 if (do_swap_account
)
5616 __mem_cgroup_threshold(memcg
, true);
5618 memcg
= parent_mem_cgroup(memcg
);
5622 static int compare_thresholds(const void *a
, const void *b
)
5624 const struct mem_cgroup_threshold
*_a
= a
;
5625 const struct mem_cgroup_threshold
*_b
= b
;
5627 if (_a
->threshold
> _b
->threshold
)
5630 if (_a
->threshold
< _b
->threshold
)
5636 static int mem_cgroup_oom_notify_cb(struct mem_cgroup
*memcg
)
5638 struct mem_cgroup_eventfd_list
*ev
;
5640 list_for_each_entry(ev
, &memcg
->oom_notify
, list
)
5641 eventfd_signal(ev
->eventfd
, 1);
5645 static void mem_cgroup_oom_notify(struct mem_cgroup
*memcg
)
5647 struct mem_cgroup
*iter
;
5649 for_each_mem_cgroup_tree(iter
, memcg
)
5650 mem_cgroup_oom_notify_cb(iter
);
5653 static int mem_cgroup_usage_register_event(struct cgroup_subsys_state
*css
,
5654 struct cftype
*cft
, struct eventfd_ctx
*eventfd
, const char *args
)
5656 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
5657 struct mem_cgroup_thresholds
*thresholds
;
5658 struct mem_cgroup_threshold_ary
*new;
5659 enum res_type type
= MEMFILE_TYPE(cft
->private);
5660 u64 threshold
, usage
;
5663 ret
= res_counter_memparse_write_strategy(args
, &threshold
);
5667 mutex_lock(&memcg
->thresholds_lock
);
5670 thresholds
= &memcg
->thresholds
;
5671 else if (type
== _MEMSWAP
)
5672 thresholds
= &memcg
->memsw_thresholds
;
5676 usage
= mem_cgroup_usage(memcg
, type
== _MEMSWAP
);
5678 /* Check if a threshold crossed before adding a new one */
5679 if (thresholds
->primary
)
5680 __mem_cgroup_threshold(memcg
, type
== _MEMSWAP
);
5682 size
= thresholds
->primary
? thresholds
->primary
->size
+ 1 : 1;
5684 /* Allocate memory for new array of thresholds */
5685 new = kmalloc(sizeof(*new) + size
* sizeof(struct mem_cgroup_threshold
),
5693 /* Copy thresholds (if any) to new array */
5694 if (thresholds
->primary
) {
5695 memcpy(new->entries
, thresholds
->primary
->entries
, (size
- 1) *
5696 sizeof(struct mem_cgroup_threshold
));
5699 /* Add new threshold */
5700 new->entries
[size
- 1].eventfd
= eventfd
;
5701 new->entries
[size
- 1].threshold
= threshold
;
5703 /* Sort thresholds. Registering of new threshold isn't time-critical */
5704 sort(new->entries
, size
, sizeof(struct mem_cgroup_threshold
),
5705 compare_thresholds
, NULL
);
5707 /* Find current threshold */
5708 new->current_threshold
= -1;
5709 for (i
= 0; i
< size
; i
++) {
5710 if (new->entries
[i
].threshold
<= usage
) {
5712 * new->current_threshold will not be used until
5713 * rcu_assign_pointer(), so it's safe to increment
5716 ++new->current_threshold
;
5721 /* Free old spare buffer and save old primary buffer as spare */
5722 kfree(thresholds
->spare
);
5723 thresholds
->spare
= thresholds
->primary
;
5725 rcu_assign_pointer(thresholds
->primary
, new);
5727 /* To be sure that nobody uses thresholds */
5731 mutex_unlock(&memcg
->thresholds_lock
);
5736 static void mem_cgroup_usage_unregister_event(struct cgroup_subsys_state
*css
,
5737 struct cftype
*cft
, struct eventfd_ctx
*eventfd
)
5739 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
5740 struct mem_cgroup_thresholds
*thresholds
;
5741 struct mem_cgroup_threshold_ary
*new;
5742 enum res_type type
= MEMFILE_TYPE(cft
->private);
5746 mutex_lock(&memcg
->thresholds_lock
);
5748 thresholds
= &memcg
->thresholds
;
5749 else if (type
== _MEMSWAP
)
5750 thresholds
= &memcg
->memsw_thresholds
;
5754 if (!thresholds
->primary
)
5757 usage
= mem_cgroup_usage(memcg
, type
== _MEMSWAP
);
5759 /* Check if a threshold crossed before removing */
5760 __mem_cgroup_threshold(memcg
, type
== _MEMSWAP
);
5762 /* Calculate new number of threshold */
5764 for (i
= 0; i
< thresholds
->primary
->size
; i
++) {
5765 if (thresholds
->primary
->entries
[i
].eventfd
!= eventfd
)
5769 new = thresholds
->spare
;
5771 /* Set thresholds array to NULL if we don't have thresholds */
5780 /* Copy thresholds and find current threshold */
5781 new->current_threshold
= -1;
5782 for (i
= 0, j
= 0; i
< thresholds
->primary
->size
; i
++) {
5783 if (thresholds
->primary
->entries
[i
].eventfd
== eventfd
)
5786 new->entries
[j
] = thresholds
->primary
->entries
[i
];
5787 if (new->entries
[j
].threshold
<= usage
) {
5789 * new->current_threshold will not be used
5790 * until rcu_assign_pointer(), so it's safe to increment
5793 ++new->current_threshold
;
5799 /* Swap primary and spare array */
5800 thresholds
->spare
= thresholds
->primary
;
5801 /* If all events are unregistered, free the spare array */
5803 kfree(thresholds
->spare
);
5804 thresholds
->spare
= NULL
;
5807 rcu_assign_pointer(thresholds
->primary
, new);
5809 /* To be sure that nobody uses thresholds */
5812 mutex_unlock(&memcg
->thresholds_lock
);
5815 static int mem_cgroup_oom_register_event(struct cgroup_subsys_state
*css
,
5816 struct cftype
*cft
, struct eventfd_ctx
*eventfd
, const char *args
)
5818 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
5819 struct mem_cgroup_eventfd_list
*event
;
5820 enum res_type type
= MEMFILE_TYPE(cft
->private);
5822 BUG_ON(type
!= _OOM_TYPE
);
5823 event
= kmalloc(sizeof(*event
), GFP_KERNEL
);
5827 spin_lock(&memcg_oom_lock
);
5829 event
->eventfd
= eventfd
;
5830 list_add(&event
->list
, &memcg
->oom_notify
);
5832 /* already in OOM ? */
5833 if (atomic_read(&memcg
->under_oom
))
5834 eventfd_signal(eventfd
, 1);
5835 spin_unlock(&memcg_oom_lock
);
5840 static void mem_cgroup_oom_unregister_event(struct cgroup_subsys_state
*css
,
5841 struct cftype
*cft
, struct eventfd_ctx
*eventfd
)
5843 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
5844 struct mem_cgroup_eventfd_list
*ev
, *tmp
;
5845 enum res_type type
= MEMFILE_TYPE(cft
->private);
5847 BUG_ON(type
!= _OOM_TYPE
);
5849 spin_lock(&memcg_oom_lock
);
5851 list_for_each_entry_safe(ev
, tmp
, &memcg
->oom_notify
, list
) {
5852 if (ev
->eventfd
== eventfd
) {
5853 list_del(&ev
->list
);
5858 spin_unlock(&memcg_oom_lock
);
5861 static int mem_cgroup_oom_control_read(struct cgroup_subsys_state
*css
,
5862 struct cftype
*cft
, struct cgroup_map_cb
*cb
)
5864 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
5866 cb
->fill(cb
, "oom_kill_disable", memcg
->oom_kill_disable
);
5868 if (atomic_read(&memcg
->under_oom
))
5869 cb
->fill(cb
, "under_oom", 1);
5871 cb
->fill(cb
, "under_oom", 0);
5875 static int mem_cgroup_oom_control_write(struct cgroup_subsys_state
*css
,
5876 struct cftype
*cft
, u64 val
)
5878 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
5879 struct mem_cgroup
*parent
= mem_cgroup_from_css(css_parent(&memcg
->css
));
5881 /* cannot set to root cgroup and only 0 and 1 are allowed */
5882 if (!parent
|| !((val
== 0) || (val
== 1)))
5885 mutex_lock(&memcg_create_mutex
);
5886 /* oom-kill-disable is a flag for subhierarchy. */
5887 if ((parent
->use_hierarchy
) || memcg_has_children(memcg
)) {
5888 mutex_unlock(&memcg_create_mutex
);
5891 memcg
->oom_kill_disable
= val
;
5893 memcg_oom_recover(memcg
);
5894 mutex_unlock(&memcg_create_mutex
);
5898 #ifdef CONFIG_MEMCG_KMEM
5899 static int memcg_init_kmem(struct mem_cgroup
*memcg
, struct cgroup_subsys
*ss
)
5903 memcg
->kmemcg_id
= -1;
5904 ret
= memcg_propagate_kmem(memcg
);
5908 return mem_cgroup_sockets_init(memcg
, ss
);
5911 static void memcg_destroy_kmem(struct mem_cgroup
*memcg
)
5913 mem_cgroup_sockets_destroy(memcg
);
5916 static void kmem_cgroup_css_offline(struct mem_cgroup
*memcg
)
5918 if (!memcg_kmem_is_active(memcg
))
5922 * kmem charges can outlive the cgroup. In the case of slab
5923 * pages, for instance, a page contain objects from various
5924 * processes. As we prevent from taking a reference for every
5925 * such allocation we have to be careful when doing uncharge
5926 * (see memcg_uncharge_kmem) and here during offlining.
5928 * The idea is that that only the _last_ uncharge which sees
5929 * the dead memcg will drop the last reference. An additional
5930 * reference is taken here before the group is marked dead
5931 * which is then paired with css_put during uncharge resp. here.
5933 * Although this might sound strange as this path is called from
5934 * css_offline() when the referencemight have dropped down to 0
5935 * and shouldn't be incremented anymore (css_tryget would fail)
5936 * we do not have other options because of the kmem allocations
5939 css_get(&memcg
->css
);
5941 memcg_kmem_mark_dead(memcg
);
5943 if (res_counter_read_u64(&memcg
->kmem
, RES_USAGE
) != 0)
5946 if (memcg_kmem_test_and_clear_dead(memcg
))
5947 css_put(&memcg
->css
);
5950 static int memcg_init_kmem(struct mem_cgroup
*memcg
, struct cgroup_subsys
*ss
)
5955 static void memcg_destroy_kmem(struct mem_cgroup
*memcg
)
5959 static void kmem_cgroup_css_offline(struct mem_cgroup
*memcg
)
5964 static struct cftype mem_cgroup_files
[] = {
5966 .name
= "usage_in_bytes",
5967 .private = MEMFILE_PRIVATE(_MEM
, RES_USAGE
),
5968 .read
= mem_cgroup_read
,
5969 .register_event
= mem_cgroup_usage_register_event
,
5970 .unregister_event
= mem_cgroup_usage_unregister_event
,
5973 .name
= "max_usage_in_bytes",
5974 .private = MEMFILE_PRIVATE(_MEM
, RES_MAX_USAGE
),
5975 .trigger
= mem_cgroup_reset
,
5976 .read
= mem_cgroup_read
,
5979 .name
= "limit_in_bytes",
5980 .private = MEMFILE_PRIVATE(_MEM
, RES_LIMIT
),
5981 .write_string
= mem_cgroup_write
,
5982 .read
= mem_cgroup_read
,
5985 .name
= "soft_limit_in_bytes",
5986 .private = MEMFILE_PRIVATE(_MEM
, RES_SOFT_LIMIT
),
5987 .write_string
= mem_cgroup_write
,
5988 .read
= mem_cgroup_read
,
5992 .private = MEMFILE_PRIVATE(_MEM
, RES_FAILCNT
),
5993 .trigger
= mem_cgroup_reset
,
5994 .read
= mem_cgroup_read
,
5998 .read_seq_string
= memcg_stat_show
,
6001 .name
= "force_empty",
6002 .trigger
= mem_cgroup_force_empty_write
,
6005 .name
= "use_hierarchy",
6006 .flags
= CFTYPE_INSANE
,
6007 .write_u64
= mem_cgroup_hierarchy_write
,
6008 .read_u64
= mem_cgroup_hierarchy_read
,
6011 .name
= "swappiness",
6012 .read_u64
= mem_cgroup_swappiness_read
,
6013 .write_u64
= mem_cgroup_swappiness_write
,
6016 .name
= "move_charge_at_immigrate",
6017 .read_u64
= mem_cgroup_move_charge_read
,
6018 .write_u64
= mem_cgroup_move_charge_write
,
6021 .name
= "oom_control",
6022 .read_map
= mem_cgroup_oom_control_read
,
6023 .write_u64
= mem_cgroup_oom_control_write
,
6024 .register_event
= mem_cgroup_oom_register_event
,
6025 .unregister_event
= mem_cgroup_oom_unregister_event
,
6026 .private = MEMFILE_PRIVATE(_OOM_TYPE
, OOM_CONTROL
),
6029 .name
= "pressure_level",
6030 .register_event
= vmpressure_register_event
,
6031 .unregister_event
= vmpressure_unregister_event
,
6035 .name
= "numa_stat",
6036 .read_seq_string
= memcg_numa_stat_show
,
6039 #ifdef CONFIG_MEMCG_KMEM
6041 .name
= "kmem.limit_in_bytes",
6042 .private = MEMFILE_PRIVATE(_KMEM
, RES_LIMIT
),
6043 .write_string
= mem_cgroup_write
,
6044 .read
= mem_cgroup_read
,
6047 .name
= "kmem.usage_in_bytes",
6048 .private = MEMFILE_PRIVATE(_KMEM
, RES_USAGE
),
6049 .read
= mem_cgroup_read
,
6052 .name
= "kmem.failcnt",
6053 .private = MEMFILE_PRIVATE(_KMEM
, RES_FAILCNT
),
6054 .trigger
= mem_cgroup_reset
,
6055 .read
= mem_cgroup_read
,
6058 .name
= "kmem.max_usage_in_bytes",
6059 .private = MEMFILE_PRIVATE(_KMEM
, RES_MAX_USAGE
),
6060 .trigger
= mem_cgroup_reset
,
6061 .read
= mem_cgroup_read
,
6063 #ifdef CONFIG_SLABINFO
6065 .name
= "kmem.slabinfo",
6066 .read_seq_string
= mem_cgroup_slabinfo_read
,
6070 { }, /* terminate */
6073 #ifdef CONFIG_MEMCG_SWAP
6074 static struct cftype memsw_cgroup_files
[] = {
6076 .name
= "memsw.usage_in_bytes",
6077 .private = MEMFILE_PRIVATE(_MEMSWAP
, RES_USAGE
),
6078 .read
= mem_cgroup_read
,
6079 .register_event
= mem_cgroup_usage_register_event
,
6080 .unregister_event
= mem_cgroup_usage_unregister_event
,
6083 .name
= "memsw.max_usage_in_bytes",
6084 .private = MEMFILE_PRIVATE(_MEMSWAP
, RES_MAX_USAGE
),
6085 .trigger
= mem_cgroup_reset
,
6086 .read
= mem_cgroup_read
,
6089 .name
= "memsw.limit_in_bytes",
6090 .private = MEMFILE_PRIVATE(_MEMSWAP
, RES_LIMIT
),
6091 .write_string
= mem_cgroup_write
,
6092 .read
= mem_cgroup_read
,
6095 .name
= "memsw.failcnt",
6096 .private = MEMFILE_PRIVATE(_MEMSWAP
, RES_FAILCNT
),
6097 .trigger
= mem_cgroup_reset
,
6098 .read
= mem_cgroup_read
,
6100 { }, /* terminate */
6103 static int alloc_mem_cgroup_per_zone_info(struct mem_cgroup
*memcg
, int node
)
6105 struct mem_cgroup_per_node
*pn
;
6106 struct mem_cgroup_per_zone
*mz
;
6107 int zone
, tmp
= node
;
6109 * This routine is called against possible nodes.
6110 * But it's BUG to call kmalloc() against offline node.
6112 * TODO: this routine can waste much memory for nodes which will
6113 * never be onlined. It's better to use memory hotplug callback
6116 if (!node_state(node
, N_NORMAL_MEMORY
))
6118 pn
= kzalloc_node(sizeof(*pn
), GFP_KERNEL
, tmp
);
6122 for (zone
= 0; zone
< MAX_NR_ZONES
; zone
++) {
6123 mz
= &pn
->zoneinfo
[zone
];
6124 lruvec_init(&mz
->lruvec
);
6125 mz
->usage_in_excess
= 0;
6126 mz
->on_tree
= false;
6129 memcg
->nodeinfo
[node
] = pn
;
6133 static void free_mem_cgroup_per_zone_info(struct mem_cgroup
*memcg
, int node
)
6135 kfree(memcg
->nodeinfo
[node
]);
6138 static struct mem_cgroup
*mem_cgroup_alloc(void)
6140 struct mem_cgroup
*memcg
;
6141 size_t size
= memcg_size();
6143 /* Can be very big if nr_node_ids is very big */
6144 if (size
< PAGE_SIZE
)
6145 memcg
= kzalloc(size
, GFP_KERNEL
);
6147 memcg
= vzalloc(size
);
6152 memcg
->stat
= alloc_percpu(struct mem_cgroup_stat_cpu
);
6155 spin_lock_init(&memcg
->pcp_counter_lock
);
6159 if (size
< PAGE_SIZE
)
6167 * At destroying mem_cgroup, references from swap_cgroup can remain.
6168 * (scanning all at force_empty is too costly...)
6170 * Instead of clearing all references at force_empty, we remember
6171 * the number of reference from swap_cgroup and free mem_cgroup when
6172 * it goes down to 0.
6174 * Removal of cgroup itself succeeds regardless of refs from swap.
6177 static void __mem_cgroup_free(struct mem_cgroup
*memcg
)
6180 size_t size
= memcg_size();
6182 mem_cgroup_remove_from_trees(memcg
);
6183 free_css_id(&mem_cgroup_subsys
, &memcg
->css
);
6186 free_mem_cgroup_per_zone_info(memcg
, node
);
6188 free_percpu(memcg
->stat
);
6191 * We need to make sure that (at least for now), the jump label
6192 * destruction code runs outside of the cgroup lock. This is because
6193 * get_online_cpus(), which is called from the static_branch update,
6194 * can't be called inside the cgroup_lock. cpusets are the ones
6195 * enforcing this dependency, so if they ever change, we might as well.
6197 * schedule_work() will guarantee this happens. Be careful if you need
6198 * to move this code around, and make sure it is outside
6201 disarm_static_keys(memcg
);
6202 if (size
< PAGE_SIZE
)
6209 * Returns the parent mem_cgroup in memcgroup hierarchy with hierarchy enabled.
6211 struct mem_cgroup
*parent_mem_cgroup(struct mem_cgroup
*memcg
)
6213 if (!memcg
->res
.parent
)
6215 return mem_cgroup_from_res_counter(memcg
->res
.parent
, res
);
6217 EXPORT_SYMBOL(parent_mem_cgroup
);
6219 static void __init
mem_cgroup_soft_limit_tree_init(void)
6221 struct mem_cgroup_tree_per_node
*rtpn
;
6222 struct mem_cgroup_tree_per_zone
*rtpz
;
6223 int tmp
, node
, zone
;
6225 for_each_node(node
) {
6227 if (!node_state(node
, N_NORMAL_MEMORY
))
6229 rtpn
= kzalloc_node(sizeof(*rtpn
), GFP_KERNEL
, tmp
);
6232 soft_limit_tree
.rb_tree_per_node
[node
] = rtpn
;
6234 for (zone
= 0; zone
< MAX_NR_ZONES
; zone
++) {
6235 rtpz
= &rtpn
->rb_tree_per_zone
[zone
];
6236 rtpz
->rb_root
= RB_ROOT
;
6237 spin_lock_init(&rtpz
->lock
);
6242 static struct cgroup_subsys_state
* __ref
6243 mem_cgroup_css_alloc(struct cgroup_subsys_state
*parent_css
)
6245 struct mem_cgroup
*memcg
;
6246 long error
= -ENOMEM
;
6249 memcg
= mem_cgroup_alloc();
6251 return ERR_PTR(error
);
6254 if (alloc_mem_cgroup_per_zone_info(memcg
, node
))
6258 if (parent_css
== NULL
) {
6259 root_mem_cgroup
= memcg
;
6260 res_counter_init(&memcg
->res
, NULL
);
6261 res_counter_init(&memcg
->memsw
, NULL
);
6262 res_counter_init(&memcg
->kmem
, NULL
);
6265 memcg
->last_scanned_node
= MAX_NUMNODES
;
6266 INIT_LIST_HEAD(&memcg
->oom_notify
);
6267 memcg
->move_charge_at_immigrate
= 0;
6268 mutex_init(&memcg
->thresholds_lock
);
6269 spin_lock_init(&memcg
->move_lock
);
6270 vmpressure_init(&memcg
->vmpressure
);
6275 __mem_cgroup_free(memcg
);
6276 return ERR_PTR(error
);
6280 mem_cgroup_css_online(struct cgroup_subsys_state
*css
)
6282 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
6283 struct mem_cgroup
*parent
= mem_cgroup_from_css(css_parent(css
));
6289 mutex_lock(&memcg_create_mutex
);
6291 memcg
->use_hierarchy
= parent
->use_hierarchy
;
6292 memcg
->oom_kill_disable
= parent
->oom_kill_disable
;
6293 memcg
->swappiness
= mem_cgroup_swappiness(parent
);
6295 if (parent
->use_hierarchy
) {
6296 res_counter_init(&memcg
->res
, &parent
->res
);
6297 res_counter_init(&memcg
->memsw
, &parent
->memsw
);
6298 res_counter_init(&memcg
->kmem
, &parent
->kmem
);
6301 * No need to take a reference to the parent because cgroup
6302 * core guarantees its existence.
6305 res_counter_init(&memcg
->res
, NULL
);
6306 res_counter_init(&memcg
->memsw
, NULL
);
6307 res_counter_init(&memcg
->kmem
, NULL
);
6309 * Deeper hierachy with use_hierarchy == false doesn't make
6310 * much sense so let cgroup subsystem know about this
6311 * unfortunate state in our controller.
6313 if (parent
!= root_mem_cgroup
)
6314 mem_cgroup_subsys
.broken_hierarchy
= true;
6317 error
= memcg_init_kmem(memcg
, &mem_cgroup_subsys
);
6318 mutex_unlock(&memcg_create_mutex
);
6323 * Announce all parents that a group from their hierarchy is gone.
6325 static void mem_cgroup_invalidate_reclaim_iterators(struct mem_cgroup
*memcg
)
6327 struct mem_cgroup
*parent
= memcg
;
6329 while ((parent
= parent_mem_cgroup(parent
)))
6330 mem_cgroup_iter_invalidate(parent
);
6333 * if the root memcg is not hierarchical we have to check it
6336 if (!root_mem_cgroup
->use_hierarchy
)
6337 mem_cgroup_iter_invalidate(root_mem_cgroup
);
6340 static void mem_cgroup_css_offline(struct cgroup_subsys_state
*css
)
6342 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
6344 kmem_cgroup_css_offline(memcg
);
6346 mem_cgroup_invalidate_reclaim_iterators(memcg
);
6347 mem_cgroup_reparent_charges(memcg
);
6348 mem_cgroup_destroy_all_caches(memcg
);
6349 vmpressure_cleanup(&memcg
->vmpressure
);
6352 static void mem_cgroup_css_free(struct cgroup_subsys_state
*css
)
6354 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
6356 memcg_destroy_kmem(memcg
);
6357 __mem_cgroup_free(memcg
);
6361 /* Handlers for move charge at task migration. */
6362 #define PRECHARGE_COUNT_AT_ONCE 256
6363 static int mem_cgroup_do_precharge(unsigned long count
)
6366 int batch_count
= PRECHARGE_COUNT_AT_ONCE
;
6367 struct mem_cgroup
*memcg
= mc
.to
;
6369 if (mem_cgroup_is_root(memcg
)) {
6370 mc
.precharge
+= count
;
6371 /* we don't need css_get for root */
6374 /* try to charge at once */
6376 struct res_counter
*dummy
;
6378 * "memcg" cannot be under rmdir() because we've already checked
6379 * by cgroup_lock_live_cgroup() that it is not removed and we
6380 * are still under the same cgroup_mutex. So we can postpone
6383 if (res_counter_charge(&memcg
->res
, PAGE_SIZE
* count
, &dummy
))
6385 if (do_swap_account
&& res_counter_charge(&memcg
->memsw
,
6386 PAGE_SIZE
* count
, &dummy
)) {
6387 res_counter_uncharge(&memcg
->res
, PAGE_SIZE
* count
);
6390 mc
.precharge
+= count
;
6394 /* fall back to one by one charge */
6396 if (signal_pending(current
)) {
6400 if (!batch_count
--) {
6401 batch_count
= PRECHARGE_COUNT_AT_ONCE
;
6404 ret
= __mem_cgroup_try_charge(NULL
,
6405 GFP_KERNEL
, 1, &memcg
, false);
6407 /* mem_cgroup_clear_mc() will do uncharge later */
6415 * get_mctgt_type - get target type of moving charge
6416 * @vma: the vma the pte to be checked belongs
6417 * @addr: the address corresponding to the pte to be checked
6418 * @ptent: the pte to be checked
6419 * @target: the pointer the target page or swap ent will be stored(can be NULL)
6422 * 0(MC_TARGET_NONE): if the pte is not a target for move charge.
6423 * 1(MC_TARGET_PAGE): if the page corresponding to this pte is a target for
6424 * move charge. if @target is not NULL, the page is stored in target->page
6425 * with extra refcnt got(Callers should handle it).
6426 * 2(MC_TARGET_SWAP): if the swap entry corresponding to this pte is a
6427 * target for charge migration. if @target is not NULL, the entry is stored
6430 * Called with pte lock held.
6437 enum mc_target_type
{
6443 static struct page
*mc_handle_present_pte(struct vm_area_struct
*vma
,
6444 unsigned long addr
, pte_t ptent
)
6446 struct page
*page
= vm_normal_page(vma
, addr
, ptent
);
6448 if (!page
|| !page_mapped(page
))
6450 if (PageAnon(page
)) {
6451 /* we don't move shared anon */
6454 } else if (!move_file())
6455 /* we ignore mapcount for file pages */
6457 if (!get_page_unless_zero(page
))
6464 static struct page
*mc_handle_swap_pte(struct vm_area_struct
*vma
,
6465 unsigned long addr
, pte_t ptent
, swp_entry_t
*entry
)
6467 struct page
*page
= NULL
;
6468 swp_entry_t ent
= pte_to_swp_entry(ptent
);
6470 if (!move_anon() || non_swap_entry(ent
))
6473 * Because lookup_swap_cache() updates some statistics counter,
6474 * we call find_get_page() with swapper_space directly.
6476 page
= find_get_page(swap_address_space(ent
), ent
.val
);
6477 if (do_swap_account
)
6478 entry
->val
= ent
.val
;
6483 static struct page
*mc_handle_swap_pte(struct vm_area_struct
*vma
,
6484 unsigned long addr
, pte_t ptent
, swp_entry_t
*entry
)
6490 static struct page
*mc_handle_file_pte(struct vm_area_struct
*vma
,
6491 unsigned long addr
, pte_t ptent
, swp_entry_t
*entry
)
6493 struct page
*page
= NULL
;
6494 struct address_space
*mapping
;
6497 if (!vma
->vm_file
) /* anonymous vma */
6502 mapping
= vma
->vm_file
->f_mapping
;
6503 if (pte_none(ptent
))
6504 pgoff
= linear_page_index(vma
, addr
);
6505 else /* pte_file(ptent) is true */
6506 pgoff
= pte_to_pgoff(ptent
);
6508 /* page is moved even if it's not RSS of this task(page-faulted). */
6509 page
= find_get_page(mapping
, pgoff
);
6512 /* shmem/tmpfs may report page out on swap: account for that too. */
6513 if (radix_tree_exceptional_entry(page
)) {
6514 swp_entry_t swap
= radix_to_swp_entry(page
);
6515 if (do_swap_account
)
6517 page
= find_get_page(swap_address_space(swap
), swap
.val
);
6523 static enum mc_target_type
get_mctgt_type(struct vm_area_struct
*vma
,
6524 unsigned long addr
, pte_t ptent
, union mc_target
*target
)
6526 struct page
*page
= NULL
;
6527 struct page_cgroup
*pc
;
6528 enum mc_target_type ret
= MC_TARGET_NONE
;
6529 swp_entry_t ent
= { .val
= 0 };
6531 if (pte_present(ptent
))
6532 page
= mc_handle_present_pte(vma
, addr
, ptent
);
6533 else if (is_swap_pte(ptent
))
6534 page
= mc_handle_swap_pte(vma
, addr
, ptent
, &ent
);
6535 else if (pte_none(ptent
) || pte_file(ptent
))
6536 page
= mc_handle_file_pte(vma
, addr
, ptent
, &ent
);
6538 if (!page
&& !ent
.val
)
6541 pc
= lookup_page_cgroup(page
);
6543 * Do only loose check w/o page_cgroup lock.
6544 * mem_cgroup_move_account() checks the pc is valid or not under
6547 if (PageCgroupUsed(pc
) && pc
->mem_cgroup
== mc
.from
) {
6548 ret
= MC_TARGET_PAGE
;
6550 target
->page
= page
;
6552 if (!ret
|| !target
)
6555 /* There is a swap entry and a page doesn't exist or isn't charged */
6556 if (ent
.val
&& !ret
&&
6557 css_id(&mc
.from
->css
) == lookup_swap_cgroup_id(ent
)) {
6558 ret
= MC_TARGET_SWAP
;
6565 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
6567 * We don't consider swapping or file mapped pages because THP does not
6568 * support them for now.
6569 * Caller should make sure that pmd_trans_huge(pmd) is true.
6571 static enum mc_target_type
get_mctgt_type_thp(struct vm_area_struct
*vma
,
6572 unsigned long addr
, pmd_t pmd
, union mc_target
*target
)
6574 struct page
*page
= NULL
;
6575 struct page_cgroup
*pc
;
6576 enum mc_target_type ret
= MC_TARGET_NONE
;
6578 page
= pmd_page(pmd
);
6579 VM_BUG_ON(!page
|| !PageHead(page
));
6582 pc
= lookup_page_cgroup(page
);
6583 if (PageCgroupUsed(pc
) && pc
->mem_cgroup
== mc
.from
) {
6584 ret
= MC_TARGET_PAGE
;
6587 target
->page
= page
;
6593 static inline enum mc_target_type
get_mctgt_type_thp(struct vm_area_struct
*vma
,
6594 unsigned long addr
, pmd_t pmd
, union mc_target
*target
)
6596 return MC_TARGET_NONE
;
6600 static int mem_cgroup_count_precharge_pte_range(pmd_t
*pmd
,
6601 unsigned long addr
, unsigned long end
,
6602 struct mm_walk
*walk
)
6604 struct vm_area_struct
*vma
= walk
->private;
6608 if (pmd_trans_huge_lock(pmd
, vma
) == 1) {
6609 if (get_mctgt_type_thp(vma
, addr
, *pmd
, NULL
) == MC_TARGET_PAGE
)
6610 mc
.precharge
+= HPAGE_PMD_NR
;
6611 spin_unlock(&vma
->vm_mm
->page_table_lock
);
6615 if (pmd_trans_unstable(pmd
))
6617 pte
= pte_offset_map_lock(vma
->vm_mm
, pmd
, addr
, &ptl
);
6618 for (; addr
!= end
; pte
++, addr
+= PAGE_SIZE
)
6619 if (get_mctgt_type(vma
, addr
, *pte
, NULL
))
6620 mc
.precharge
++; /* increment precharge temporarily */
6621 pte_unmap_unlock(pte
- 1, ptl
);
6627 static unsigned long mem_cgroup_count_precharge(struct mm_struct
*mm
)
6629 unsigned long precharge
;
6630 struct vm_area_struct
*vma
;
6632 down_read(&mm
->mmap_sem
);
6633 for (vma
= mm
->mmap
; vma
; vma
= vma
->vm_next
) {
6634 struct mm_walk mem_cgroup_count_precharge_walk
= {
6635 .pmd_entry
= mem_cgroup_count_precharge_pte_range
,
6639 if (is_vm_hugetlb_page(vma
))
6641 walk_page_range(vma
->vm_start
, vma
->vm_end
,
6642 &mem_cgroup_count_precharge_walk
);
6644 up_read(&mm
->mmap_sem
);
6646 precharge
= mc
.precharge
;
6652 static int mem_cgroup_precharge_mc(struct mm_struct
*mm
)
6654 unsigned long precharge
= mem_cgroup_count_precharge(mm
);
6656 VM_BUG_ON(mc
.moving_task
);
6657 mc
.moving_task
= current
;
6658 return mem_cgroup_do_precharge(precharge
);
6661 /* cancels all extra charges on mc.from and mc.to, and wakes up all waiters. */
6662 static void __mem_cgroup_clear_mc(void)
6664 struct mem_cgroup
*from
= mc
.from
;
6665 struct mem_cgroup
*to
= mc
.to
;
6668 /* we must uncharge all the leftover precharges from mc.to */
6670 __mem_cgroup_cancel_charge(mc
.to
, mc
.precharge
);
6674 * we didn't uncharge from mc.from at mem_cgroup_move_account(), so
6675 * we must uncharge here.
6677 if (mc
.moved_charge
) {
6678 __mem_cgroup_cancel_charge(mc
.from
, mc
.moved_charge
);
6679 mc
.moved_charge
= 0;
6681 /* we must fixup refcnts and charges */
6682 if (mc
.moved_swap
) {
6683 /* uncharge swap account from the old cgroup */
6684 if (!mem_cgroup_is_root(mc
.from
))
6685 res_counter_uncharge(&mc
.from
->memsw
,
6686 PAGE_SIZE
* mc
.moved_swap
);
6688 for (i
= 0; i
< mc
.moved_swap
; i
++)
6689 css_put(&mc
.from
->css
);
6691 if (!mem_cgroup_is_root(mc
.to
)) {
6693 * we charged both to->res and to->memsw, so we should
6696 res_counter_uncharge(&mc
.to
->res
,
6697 PAGE_SIZE
* mc
.moved_swap
);
6699 /* we've already done css_get(mc.to) */
6702 memcg_oom_recover(from
);
6703 memcg_oom_recover(to
);
6704 wake_up_all(&mc
.waitq
);
6707 static void mem_cgroup_clear_mc(void)
6709 struct mem_cgroup
*from
= mc
.from
;
6712 * we must clear moving_task before waking up waiters at the end of
6715 mc
.moving_task
= NULL
;
6716 __mem_cgroup_clear_mc();
6717 spin_lock(&mc
.lock
);
6720 spin_unlock(&mc
.lock
);
6721 mem_cgroup_end_move(from
);
6724 static int mem_cgroup_can_attach(struct cgroup_subsys_state
*css
,
6725 struct cgroup_taskset
*tset
)
6727 struct task_struct
*p
= cgroup_taskset_first(tset
);
6729 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
6730 unsigned long move_charge_at_immigrate
;
6733 * We are now commited to this value whatever it is. Changes in this
6734 * tunable will only affect upcoming migrations, not the current one.
6735 * So we need to save it, and keep it going.
6737 move_charge_at_immigrate
= memcg
->move_charge_at_immigrate
;
6738 if (move_charge_at_immigrate
) {
6739 struct mm_struct
*mm
;
6740 struct mem_cgroup
*from
= mem_cgroup_from_task(p
);
6742 VM_BUG_ON(from
== memcg
);
6744 mm
= get_task_mm(p
);
6747 /* We move charges only when we move a owner of the mm */
6748 if (mm
->owner
== p
) {
6751 VM_BUG_ON(mc
.precharge
);
6752 VM_BUG_ON(mc
.moved_charge
);
6753 VM_BUG_ON(mc
.moved_swap
);
6754 mem_cgroup_start_move(from
);
6755 spin_lock(&mc
.lock
);
6758 mc
.immigrate_flags
= move_charge_at_immigrate
;
6759 spin_unlock(&mc
.lock
);
6760 /* We set mc.moving_task later */
6762 ret
= mem_cgroup_precharge_mc(mm
);
6764 mem_cgroup_clear_mc();
6771 static void mem_cgroup_cancel_attach(struct cgroup_subsys_state
*css
,
6772 struct cgroup_taskset
*tset
)
6774 mem_cgroup_clear_mc();
6777 static int mem_cgroup_move_charge_pte_range(pmd_t
*pmd
,
6778 unsigned long addr
, unsigned long end
,
6779 struct mm_walk
*walk
)
6782 struct vm_area_struct
*vma
= walk
->private;
6785 enum mc_target_type target_type
;
6786 union mc_target target
;
6788 struct page_cgroup
*pc
;
6791 * We don't take compound_lock() here but no race with splitting thp
6793 * - if pmd_trans_huge_lock() returns 1, the relevant thp is not
6794 * under splitting, which means there's no concurrent thp split,
6795 * - if another thread runs into split_huge_page() just after we
6796 * entered this if-block, the thread must wait for page table lock
6797 * to be unlocked in __split_huge_page_splitting(), where the main
6798 * part of thp split is not executed yet.
6800 if (pmd_trans_huge_lock(pmd
, vma
) == 1) {
6801 if (mc
.precharge
< HPAGE_PMD_NR
) {
6802 spin_unlock(&vma
->vm_mm
->page_table_lock
);
6805 target_type
= get_mctgt_type_thp(vma
, addr
, *pmd
, &target
);
6806 if (target_type
== MC_TARGET_PAGE
) {
6808 if (!isolate_lru_page(page
)) {
6809 pc
= lookup_page_cgroup(page
);
6810 if (!mem_cgroup_move_account(page
, HPAGE_PMD_NR
,
6811 pc
, mc
.from
, mc
.to
)) {
6812 mc
.precharge
-= HPAGE_PMD_NR
;
6813 mc
.moved_charge
+= HPAGE_PMD_NR
;
6815 putback_lru_page(page
);
6819 spin_unlock(&vma
->vm_mm
->page_table_lock
);
6823 if (pmd_trans_unstable(pmd
))
6826 pte
= pte_offset_map_lock(vma
->vm_mm
, pmd
, addr
, &ptl
);
6827 for (; addr
!= end
; addr
+= PAGE_SIZE
) {
6828 pte_t ptent
= *(pte
++);
6834 switch (get_mctgt_type(vma
, addr
, ptent
, &target
)) {
6835 case MC_TARGET_PAGE
:
6837 if (isolate_lru_page(page
))
6839 pc
= lookup_page_cgroup(page
);
6840 if (!mem_cgroup_move_account(page
, 1, pc
,
6843 /* we uncharge from mc.from later. */
6846 putback_lru_page(page
);
6847 put
: /* get_mctgt_type() gets the page */
6850 case MC_TARGET_SWAP
:
6852 if (!mem_cgroup_move_swap_account(ent
, mc
.from
, mc
.to
)) {
6854 /* we fixup refcnts and charges later. */
6862 pte_unmap_unlock(pte
- 1, ptl
);
6867 * We have consumed all precharges we got in can_attach().
6868 * We try charge one by one, but don't do any additional
6869 * charges to mc.to if we have failed in charge once in attach()
6872 ret
= mem_cgroup_do_precharge(1);
6880 static void mem_cgroup_move_charge(struct mm_struct
*mm
)
6882 struct vm_area_struct
*vma
;
6884 lru_add_drain_all();
6886 if (unlikely(!down_read_trylock(&mm
->mmap_sem
))) {
6888 * Someone who are holding the mmap_sem might be waiting in
6889 * waitq. So we cancel all extra charges, wake up all waiters,
6890 * and retry. Because we cancel precharges, we might not be able
6891 * to move enough charges, but moving charge is a best-effort
6892 * feature anyway, so it wouldn't be a big problem.
6894 __mem_cgroup_clear_mc();
6898 for (vma
= mm
->mmap
; vma
; vma
= vma
->vm_next
) {
6900 struct mm_walk mem_cgroup_move_charge_walk
= {
6901 .pmd_entry
= mem_cgroup_move_charge_pte_range
,
6905 if (is_vm_hugetlb_page(vma
))
6907 ret
= walk_page_range(vma
->vm_start
, vma
->vm_end
,
6908 &mem_cgroup_move_charge_walk
);
6911 * means we have consumed all precharges and failed in
6912 * doing additional charge. Just abandon here.
6916 up_read(&mm
->mmap_sem
);
6919 static void mem_cgroup_move_task(struct cgroup_subsys_state
*css
,
6920 struct cgroup_taskset
*tset
)
6922 struct task_struct
*p
= cgroup_taskset_first(tset
);
6923 struct mm_struct
*mm
= get_task_mm(p
);
6927 mem_cgroup_move_charge(mm
);
6931 mem_cgroup_clear_mc();
6933 #else /* !CONFIG_MMU */
6934 static int mem_cgroup_can_attach(struct cgroup_subsys_state
*css
,
6935 struct cgroup_taskset
*tset
)
6939 static void mem_cgroup_cancel_attach(struct cgroup_subsys_state
*css
,
6940 struct cgroup_taskset
*tset
)
6943 static void mem_cgroup_move_task(struct cgroup_subsys_state
*css
,
6944 struct cgroup_taskset
*tset
)
6950 * Cgroup retains root cgroups across [un]mount cycles making it necessary
6951 * to verify sane_behavior flag on each mount attempt.
6953 static void mem_cgroup_bind(struct cgroup_subsys_state
*root_css
)
6956 * use_hierarchy is forced with sane_behavior. cgroup core
6957 * guarantees that @root doesn't have any children, so turning it
6958 * on for the root memcg is enough.
6960 if (cgroup_sane_behavior(root_css
->cgroup
))
6961 mem_cgroup_from_css(root_css
)->use_hierarchy
= true;
6964 struct cgroup_subsys mem_cgroup_subsys
= {
6966 .subsys_id
= mem_cgroup_subsys_id
,
6967 .css_alloc
= mem_cgroup_css_alloc
,
6968 .css_online
= mem_cgroup_css_online
,
6969 .css_offline
= mem_cgroup_css_offline
,
6970 .css_free
= mem_cgroup_css_free
,
6971 .can_attach
= mem_cgroup_can_attach
,
6972 .cancel_attach
= mem_cgroup_cancel_attach
,
6973 .attach
= mem_cgroup_move_task
,
6974 .bind
= mem_cgroup_bind
,
6975 .base_cftypes
= mem_cgroup_files
,
6980 #ifdef CONFIG_MEMCG_SWAP
6981 static int __init
enable_swap_account(char *s
)
6983 if (!strcmp(s
, "1"))
6984 really_do_swap_account
= 1;
6985 else if (!strcmp(s
, "0"))
6986 really_do_swap_account
= 0;
6989 __setup("swapaccount=", enable_swap_account
);
6991 static void __init
memsw_file_init(void)
6993 WARN_ON(cgroup_add_cftypes(&mem_cgroup_subsys
, memsw_cgroup_files
));
6996 static void __init
enable_swap_cgroup(void)
6998 if (!mem_cgroup_disabled() && really_do_swap_account
) {
6999 do_swap_account
= 1;
7005 static void __init
enable_swap_cgroup(void)
7011 * subsys_initcall() for memory controller.
7013 * Some parts like hotcpu_notifier() have to be initialized from this context
7014 * because of lock dependencies (cgroup_lock -> cpu hotplug) but basically
7015 * everything that doesn't depend on a specific mem_cgroup structure should
7016 * be initialized from here.
7018 static int __init
mem_cgroup_init(void)
7020 hotcpu_notifier(memcg_cpu_hotplug_callback
, 0);
7021 enable_swap_cgroup();
7022 mem_cgroup_soft_limit_tree_init();
7026 subsys_initcall(mem_cgroup_init
);