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/page_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/poll.h>
49 #include <linux/sort.h>
51 #include <linux/seq_file.h>
52 #include <linux/vmpressure.h>
53 #include <linux/mm_inline.h>
54 #include <linux/swap_cgroup.h>
55 #include <linux/cpu.h>
56 #include <linux/oom.h>
57 #include <linux/lockdep.h>
58 #include <linux/file.h>
62 #include <net/tcp_memcontrol.h>
65 #include <asm/uaccess.h>
67 #include <trace/events/vmscan.h>
69 struct cgroup_subsys memory_cgrp_subsys __read_mostly
;
70 EXPORT_SYMBOL(memory_cgrp_subsys
);
72 #define MEM_CGROUP_RECLAIM_RETRIES 5
73 static struct mem_cgroup
*root_mem_cgroup __read_mostly
;
75 /* Whether the swap controller is active */
76 #ifdef CONFIG_MEMCG_SWAP
77 int do_swap_account __read_mostly
;
79 #define do_swap_account 0
82 static const char * const mem_cgroup_stat_names
[] = {
91 static const char * const mem_cgroup_events_names
[] = {
98 static const char * const mem_cgroup_lru_names
[] = {
107 * Per memcg event counter is incremented at every pagein/pageout. With THP,
108 * it will be incremated by the number of pages. This counter is used for
109 * for trigger some periodic events. This is straightforward and better
110 * than using jiffies etc. to handle periodic memcg event.
112 enum mem_cgroup_events_target
{
113 MEM_CGROUP_TARGET_THRESH
,
114 MEM_CGROUP_TARGET_SOFTLIMIT
,
115 MEM_CGROUP_TARGET_NUMAINFO
,
118 #define THRESHOLDS_EVENTS_TARGET 128
119 #define SOFTLIMIT_EVENTS_TARGET 1024
120 #define NUMAINFO_EVENTS_TARGET 1024
122 struct mem_cgroup_stat_cpu
{
123 long count
[MEM_CGROUP_STAT_NSTATS
];
124 unsigned long events
[MEMCG_NR_EVENTS
];
125 unsigned long nr_page_events
;
126 unsigned long targets
[MEM_CGROUP_NTARGETS
];
129 struct reclaim_iter
{
130 struct mem_cgroup
*position
;
131 /* scan generation, increased every round-trip */
132 unsigned int generation
;
136 * per-zone information in memory controller.
138 struct mem_cgroup_per_zone
{
139 struct lruvec lruvec
;
140 unsigned long lru_size
[NR_LRU_LISTS
];
142 struct reclaim_iter iter
[DEF_PRIORITY
+ 1];
144 struct rb_node tree_node
; /* RB tree node */
145 unsigned long usage_in_excess
;/* Set to the value by which */
146 /* the soft limit is exceeded*/
148 struct mem_cgroup
*memcg
; /* Back pointer, we cannot */
149 /* use container_of */
152 struct mem_cgroup_per_node
{
153 struct mem_cgroup_per_zone zoneinfo
[MAX_NR_ZONES
];
157 * Cgroups above their limits are maintained in a RB-Tree, independent of
158 * their hierarchy representation
161 struct mem_cgroup_tree_per_zone
{
162 struct rb_root rb_root
;
166 struct mem_cgroup_tree_per_node
{
167 struct mem_cgroup_tree_per_zone rb_tree_per_zone
[MAX_NR_ZONES
];
170 struct mem_cgroup_tree
{
171 struct mem_cgroup_tree_per_node
*rb_tree_per_node
[MAX_NUMNODES
];
174 static struct mem_cgroup_tree soft_limit_tree __read_mostly
;
176 struct mem_cgroup_threshold
{
177 struct eventfd_ctx
*eventfd
;
178 unsigned long threshold
;
182 struct mem_cgroup_threshold_ary
{
183 /* An array index points to threshold just below or equal to usage. */
184 int current_threshold
;
185 /* Size of entries[] */
187 /* Array of thresholds */
188 struct mem_cgroup_threshold entries
[0];
191 struct mem_cgroup_thresholds
{
192 /* Primary thresholds array */
193 struct mem_cgroup_threshold_ary
*primary
;
195 * Spare threshold array.
196 * This is needed to make mem_cgroup_unregister_event() "never fail".
197 * It must be able to store at least primary->size - 1 entries.
199 struct mem_cgroup_threshold_ary
*spare
;
203 struct mem_cgroup_eventfd_list
{
204 struct list_head list
;
205 struct eventfd_ctx
*eventfd
;
209 * cgroup_event represents events which userspace want to receive.
211 struct mem_cgroup_event
{
213 * memcg which the event belongs to.
215 struct mem_cgroup
*memcg
;
217 * eventfd to signal userspace about the event.
219 struct eventfd_ctx
*eventfd
;
221 * Each of these stored in a list by the cgroup.
223 struct list_head list
;
225 * register_event() callback will be used to add new userspace
226 * waiter for changes related to this event. Use eventfd_signal()
227 * on eventfd to send notification to userspace.
229 int (*register_event
)(struct mem_cgroup
*memcg
,
230 struct eventfd_ctx
*eventfd
, const char *args
);
232 * unregister_event() callback will be called when userspace closes
233 * the eventfd or on cgroup removing. This callback must be set,
234 * if you want provide notification functionality.
236 void (*unregister_event
)(struct mem_cgroup
*memcg
,
237 struct eventfd_ctx
*eventfd
);
239 * All fields below needed to unregister event when
240 * userspace closes eventfd.
243 wait_queue_head_t
*wqh
;
245 struct work_struct remove
;
248 static void mem_cgroup_threshold(struct mem_cgroup
*memcg
);
249 static void mem_cgroup_oom_notify(struct mem_cgroup
*memcg
);
252 * The memory controller data structure. The memory controller controls both
253 * page cache and RSS per cgroup. We would eventually like to provide
254 * statistics based on the statistics developed by Rik Van Riel for clock-pro,
255 * to help the administrator determine what knobs to tune.
257 * TODO: Add a water mark for the memory controller. Reclaim will begin when
258 * we hit the water mark. May be even add a low water mark, such that
259 * no reclaim occurs from a cgroup at it's low water mark, this is
260 * a feature that will be implemented much later in the future.
263 struct cgroup_subsys_state css
;
265 /* Accounted resources */
266 struct page_counter memory
;
267 struct page_counter memsw
;
268 struct page_counter kmem
;
270 /* Normal memory consumption range */
274 unsigned long soft_limit
;
276 /* vmpressure notifications */
277 struct vmpressure vmpressure
;
279 /* css_online() has been completed */
283 * Should the accounting and control be hierarchical, per subtree?
289 atomic_t oom_wakeups
;
292 /* OOM-Killer disable */
293 int oom_kill_disable
;
295 /* protect arrays of thresholds */
296 struct mutex thresholds_lock
;
298 /* thresholds for memory usage. RCU-protected */
299 struct mem_cgroup_thresholds thresholds
;
301 /* thresholds for mem+swap usage. RCU-protected */
302 struct mem_cgroup_thresholds memsw_thresholds
;
304 /* For oom notifier event fd */
305 struct list_head oom_notify
;
308 * Should we move charges of a task when a task is moved into this
309 * mem_cgroup ? And what type of charges should we move ?
311 unsigned long move_charge_at_immigrate
;
313 * set > 0 if pages under this cgroup are moving to other cgroup.
315 atomic_t moving_account
;
316 /* taken only while moving_account > 0 */
317 spinlock_t move_lock
;
318 struct task_struct
*move_lock_task
;
319 unsigned long move_lock_flags
;
323 struct mem_cgroup_stat_cpu __percpu
*stat
;
325 * used when a cpu is offlined or other synchronizations
326 * See mem_cgroup_read_stat().
328 struct mem_cgroup_stat_cpu nocpu_base
;
329 spinlock_t pcp_counter_lock
;
331 #if defined(CONFIG_MEMCG_KMEM) && defined(CONFIG_INET)
332 struct cg_proto tcp_mem
;
334 #if defined(CONFIG_MEMCG_KMEM)
335 /* Index in the kmem_cache->memcg_params->memcg_caches array */
339 int last_scanned_node
;
341 nodemask_t scan_nodes
;
342 atomic_t numainfo_events
;
343 atomic_t numainfo_updating
;
346 /* List of events which userspace want to receive */
347 struct list_head event_list
;
348 spinlock_t event_list_lock
;
350 struct mem_cgroup_per_node
*nodeinfo
[0];
351 /* WARNING: nodeinfo must be the last member here */
354 #ifdef CONFIG_MEMCG_KMEM
355 static bool memcg_kmem_is_active(struct mem_cgroup
*memcg
)
357 return memcg
->kmemcg_id
>= 0;
361 /* Stuffs for move charges at task migration. */
363 * Types of charges to be moved.
365 #define MOVE_ANON 0x1U
366 #define MOVE_FILE 0x2U
367 #define MOVE_MASK (MOVE_ANON | MOVE_FILE)
369 /* "mc" and its members are protected by cgroup_mutex */
370 static struct move_charge_struct
{
371 spinlock_t lock
; /* for from, to */
372 struct mem_cgroup
*from
;
373 struct mem_cgroup
*to
;
375 unsigned long precharge
;
376 unsigned long moved_charge
;
377 unsigned long moved_swap
;
378 struct task_struct
*moving_task
; /* a task moving charges */
379 wait_queue_head_t waitq
; /* a waitq for other context */
381 .lock
= __SPIN_LOCK_UNLOCKED(mc
.lock
),
382 .waitq
= __WAIT_QUEUE_HEAD_INITIALIZER(mc
.waitq
),
386 * Maximum loops in mem_cgroup_hierarchical_reclaim(), used for soft
387 * limit reclaim to prevent infinite loops, if they ever occur.
389 #define MEM_CGROUP_MAX_RECLAIM_LOOPS 100
390 #define MEM_CGROUP_MAX_SOFT_LIMIT_RECLAIM_LOOPS 2
393 MEM_CGROUP_CHARGE_TYPE_CACHE
= 0,
394 MEM_CGROUP_CHARGE_TYPE_ANON
,
395 MEM_CGROUP_CHARGE_TYPE_SWAPOUT
, /* for accounting swapcache */
396 MEM_CGROUP_CHARGE_TYPE_DROP
, /* a page was unused swap cache */
400 /* for encoding cft->private value on file */
408 #define MEMFILE_PRIVATE(x, val) ((x) << 16 | (val))
409 #define MEMFILE_TYPE(val) ((val) >> 16 & 0xffff)
410 #define MEMFILE_ATTR(val) ((val) & 0xffff)
411 /* Used for OOM nofiier */
412 #define OOM_CONTROL (0)
415 * The memcg_create_mutex will be held whenever a new cgroup is created.
416 * As a consequence, any change that needs to protect against new child cgroups
417 * appearing has to hold it as well.
419 static DEFINE_MUTEX(memcg_create_mutex
);
421 struct mem_cgroup
*mem_cgroup_from_css(struct cgroup_subsys_state
*s
)
423 return s
? container_of(s
, struct mem_cgroup
, css
) : NULL
;
426 /* Some nice accessors for the vmpressure. */
427 struct vmpressure
*memcg_to_vmpressure(struct mem_cgroup
*memcg
)
430 memcg
= root_mem_cgroup
;
431 return &memcg
->vmpressure
;
434 struct cgroup_subsys_state
*vmpressure_to_css(struct vmpressure
*vmpr
)
436 return &container_of(vmpr
, struct mem_cgroup
, vmpressure
)->css
;
439 static inline bool mem_cgroup_is_root(struct mem_cgroup
*memcg
)
441 return (memcg
== root_mem_cgroup
);
445 * We restrict the id in the range of [1, 65535], so it can fit into
448 #define MEM_CGROUP_ID_MAX USHRT_MAX
450 static inline unsigned short mem_cgroup_id(struct mem_cgroup
*memcg
)
452 return memcg
->css
.id
;
455 static inline struct mem_cgroup
*mem_cgroup_from_id(unsigned short id
)
457 struct cgroup_subsys_state
*css
;
459 css
= css_from_id(id
, &memory_cgrp_subsys
);
460 return mem_cgroup_from_css(css
);
463 /* Writing them here to avoid exposing memcg's inner layout */
464 #if defined(CONFIG_INET) && defined(CONFIG_MEMCG_KMEM)
466 void sock_update_memcg(struct sock
*sk
)
468 if (mem_cgroup_sockets_enabled
) {
469 struct mem_cgroup
*memcg
;
470 struct cg_proto
*cg_proto
;
472 BUG_ON(!sk
->sk_prot
->proto_cgroup
);
474 /* Socket cloning can throw us here with sk_cgrp already
475 * filled. It won't however, necessarily happen from
476 * process context. So the test for root memcg given
477 * the current task's memcg won't help us in this case.
479 * Respecting the original socket's memcg is a better
480 * decision in this case.
483 BUG_ON(mem_cgroup_is_root(sk
->sk_cgrp
->memcg
));
484 css_get(&sk
->sk_cgrp
->memcg
->css
);
489 memcg
= mem_cgroup_from_task(current
);
490 cg_proto
= sk
->sk_prot
->proto_cgroup(memcg
);
491 if (!mem_cgroup_is_root(memcg
) &&
492 memcg_proto_active(cg_proto
) &&
493 css_tryget_online(&memcg
->css
)) {
494 sk
->sk_cgrp
= cg_proto
;
499 EXPORT_SYMBOL(sock_update_memcg
);
501 void sock_release_memcg(struct sock
*sk
)
503 if (mem_cgroup_sockets_enabled
&& sk
->sk_cgrp
) {
504 struct mem_cgroup
*memcg
;
505 WARN_ON(!sk
->sk_cgrp
->memcg
);
506 memcg
= sk
->sk_cgrp
->memcg
;
507 css_put(&sk
->sk_cgrp
->memcg
->css
);
511 struct cg_proto
*tcp_proto_cgroup(struct mem_cgroup
*memcg
)
513 if (!memcg
|| mem_cgroup_is_root(memcg
))
516 return &memcg
->tcp_mem
;
518 EXPORT_SYMBOL(tcp_proto_cgroup
);
520 static void disarm_sock_keys(struct mem_cgroup
*memcg
)
522 if (!memcg_proto_activated(&memcg
->tcp_mem
))
524 static_key_slow_dec(&memcg_socket_limit_enabled
);
527 static void disarm_sock_keys(struct mem_cgroup
*memcg
)
532 #ifdef CONFIG_MEMCG_KMEM
534 * This will be the memcg's index in each cache's ->memcg_params->memcg_caches.
535 * The main reason for not using cgroup id for this:
536 * this works better in sparse environments, where we have a lot of memcgs,
537 * but only a few kmem-limited. Or also, if we have, for instance, 200
538 * memcgs, and none but the 200th is kmem-limited, we'd have to have a
539 * 200 entry array for that.
541 * The current size of the caches array is stored in
542 * memcg_limited_groups_array_size. It will double each time we have to
545 static DEFINE_IDA(kmem_limited_groups
);
546 int memcg_limited_groups_array_size
;
549 * MIN_SIZE is different than 1, because we would like to avoid going through
550 * the alloc/free process all the time. In a small machine, 4 kmem-limited
551 * cgroups is a reasonable guess. In the future, it could be a parameter or
552 * tunable, but that is strictly not necessary.
554 * MAX_SIZE should be as large as the number of cgrp_ids. Ideally, we could get
555 * this constant directly from cgroup, but it is understandable that this is
556 * better kept as an internal representation in cgroup.c. In any case, the
557 * cgrp_id space is not getting any smaller, and we don't have to necessarily
558 * increase ours as well if it increases.
560 #define MEMCG_CACHES_MIN_SIZE 4
561 #define MEMCG_CACHES_MAX_SIZE MEM_CGROUP_ID_MAX
564 * A lot of the calls to the cache allocation functions are expected to be
565 * inlined by the compiler. Since the calls to memcg_kmem_get_cache are
566 * conditional to this static branch, we'll have to allow modules that does
567 * kmem_cache_alloc and the such to see this symbol as well
569 struct static_key memcg_kmem_enabled_key
;
570 EXPORT_SYMBOL(memcg_kmem_enabled_key
);
572 static void memcg_free_cache_id(int id
);
574 static void disarm_kmem_keys(struct mem_cgroup
*memcg
)
576 if (memcg_kmem_is_active(memcg
)) {
577 static_key_slow_dec(&memcg_kmem_enabled_key
);
578 memcg_free_cache_id(memcg
->kmemcg_id
);
581 * This check can't live in kmem destruction function,
582 * since the charges will outlive the cgroup
584 WARN_ON(page_counter_read(&memcg
->kmem
));
587 static void disarm_kmem_keys(struct mem_cgroup
*memcg
)
590 #endif /* CONFIG_MEMCG_KMEM */
592 static void disarm_static_keys(struct mem_cgroup
*memcg
)
594 disarm_sock_keys(memcg
);
595 disarm_kmem_keys(memcg
);
598 static struct mem_cgroup_per_zone
*
599 mem_cgroup_zone_zoneinfo(struct mem_cgroup
*memcg
, struct zone
*zone
)
601 int nid
= zone_to_nid(zone
);
602 int zid
= zone_idx(zone
);
604 return &memcg
->nodeinfo
[nid
]->zoneinfo
[zid
];
607 struct cgroup_subsys_state
*mem_cgroup_css(struct mem_cgroup
*memcg
)
612 static struct mem_cgroup_per_zone
*
613 mem_cgroup_page_zoneinfo(struct mem_cgroup
*memcg
, struct page
*page
)
615 int nid
= page_to_nid(page
);
616 int zid
= page_zonenum(page
);
618 return &memcg
->nodeinfo
[nid
]->zoneinfo
[zid
];
621 static struct mem_cgroup_tree_per_zone
*
622 soft_limit_tree_node_zone(int nid
, int zid
)
624 return &soft_limit_tree
.rb_tree_per_node
[nid
]->rb_tree_per_zone
[zid
];
627 static struct mem_cgroup_tree_per_zone
*
628 soft_limit_tree_from_page(struct page
*page
)
630 int nid
= page_to_nid(page
);
631 int zid
= page_zonenum(page
);
633 return &soft_limit_tree
.rb_tree_per_node
[nid
]->rb_tree_per_zone
[zid
];
636 static void __mem_cgroup_insert_exceeded(struct mem_cgroup_per_zone
*mz
,
637 struct mem_cgroup_tree_per_zone
*mctz
,
638 unsigned long new_usage_in_excess
)
640 struct rb_node
**p
= &mctz
->rb_root
.rb_node
;
641 struct rb_node
*parent
= NULL
;
642 struct mem_cgroup_per_zone
*mz_node
;
647 mz
->usage_in_excess
= new_usage_in_excess
;
648 if (!mz
->usage_in_excess
)
652 mz_node
= rb_entry(parent
, struct mem_cgroup_per_zone
,
654 if (mz
->usage_in_excess
< mz_node
->usage_in_excess
)
657 * We can't avoid mem cgroups that are over their soft
658 * limit by the same amount
660 else if (mz
->usage_in_excess
>= mz_node
->usage_in_excess
)
663 rb_link_node(&mz
->tree_node
, parent
, p
);
664 rb_insert_color(&mz
->tree_node
, &mctz
->rb_root
);
668 static void __mem_cgroup_remove_exceeded(struct mem_cgroup_per_zone
*mz
,
669 struct mem_cgroup_tree_per_zone
*mctz
)
673 rb_erase(&mz
->tree_node
, &mctz
->rb_root
);
677 static void mem_cgroup_remove_exceeded(struct mem_cgroup_per_zone
*mz
,
678 struct mem_cgroup_tree_per_zone
*mctz
)
682 spin_lock_irqsave(&mctz
->lock
, flags
);
683 __mem_cgroup_remove_exceeded(mz
, mctz
);
684 spin_unlock_irqrestore(&mctz
->lock
, flags
);
687 static unsigned long soft_limit_excess(struct mem_cgroup
*memcg
)
689 unsigned long nr_pages
= page_counter_read(&memcg
->memory
);
690 unsigned long soft_limit
= ACCESS_ONCE(memcg
->soft_limit
);
691 unsigned long excess
= 0;
693 if (nr_pages
> soft_limit
)
694 excess
= nr_pages
- soft_limit
;
699 static void mem_cgroup_update_tree(struct mem_cgroup
*memcg
, struct page
*page
)
701 unsigned long excess
;
702 struct mem_cgroup_per_zone
*mz
;
703 struct mem_cgroup_tree_per_zone
*mctz
;
705 mctz
= soft_limit_tree_from_page(page
);
707 * Necessary to update all ancestors when hierarchy is used.
708 * because their event counter is not touched.
710 for (; memcg
; memcg
= parent_mem_cgroup(memcg
)) {
711 mz
= mem_cgroup_page_zoneinfo(memcg
, page
);
712 excess
= soft_limit_excess(memcg
);
714 * We have to update the tree if mz is on RB-tree or
715 * mem is over its softlimit.
717 if (excess
|| mz
->on_tree
) {
720 spin_lock_irqsave(&mctz
->lock
, flags
);
721 /* if on-tree, remove it */
723 __mem_cgroup_remove_exceeded(mz
, mctz
);
725 * Insert again. mz->usage_in_excess will be updated.
726 * If excess is 0, no tree ops.
728 __mem_cgroup_insert_exceeded(mz
, mctz
, excess
);
729 spin_unlock_irqrestore(&mctz
->lock
, flags
);
734 static void mem_cgroup_remove_from_trees(struct mem_cgroup
*memcg
)
736 struct mem_cgroup_tree_per_zone
*mctz
;
737 struct mem_cgroup_per_zone
*mz
;
741 for (zid
= 0; zid
< MAX_NR_ZONES
; zid
++) {
742 mz
= &memcg
->nodeinfo
[nid
]->zoneinfo
[zid
];
743 mctz
= soft_limit_tree_node_zone(nid
, zid
);
744 mem_cgroup_remove_exceeded(mz
, mctz
);
749 static struct mem_cgroup_per_zone
*
750 __mem_cgroup_largest_soft_limit_node(struct mem_cgroup_tree_per_zone
*mctz
)
752 struct rb_node
*rightmost
= NULL
;
753 struct mem_cgroup_per_zone
*mz
;
757 rightmost
= rb_last(&mctz
->rb_root
);
759 goto done
; /* Nothing to reclaim from */
761 mz
= rb_entry(rightmost
, struct mem_cgroup_per_zone
, tree_node
);
763 * Remove the node now but someone else can add it back,
764 * we will to add it back at the end of reclaim to its correct
765 * position in the tree.
767 __mem_cgroup_remove_exceeded(mz
, mctz
);
768 if (!soft_limit_excess(mz
->memcg
) ||
769 !css_tryget_online(&mz
->memcg
->css
))
775 static struct mem_cgroup_per_zone
*
776 mem_cgroup_largest_soft_limit_node(struct mem_cgroup_tree_per_zone
*mctz
)
778 struct mem_cgroup_per_zone
*mz
;
780 spin_lock_irq(&mctz
->lock
);
781 mz
= __mem_cgroup_largest_soft_limit_node(mctz
);
782 spin_unlock_irq(&mctz
->lock
);
787 * Implementation Note: reading percpu statistics for memcg.
789 * Both of vmstat[] and percpu_counter has threshold and do periodic
790 * synchronization to implement "quick" read. There are trade-off between
791 * reading cost and precision of value. Then, we may have a chance to implement
792 * a periodic synchronizion of counter in memcg's counter.
794 * But this _read() function is used for user interface now. The user accounts
795 * memory usage by memory cgroup and he _always_ requires exact value because
796 * he accounts memory. Even if we provide quick-and-fuzzy read, we always
797 * have to visit all online cpus and make sum. So, for now, unnecessary
798 * synchronization is not implemented. (just implemented for cpu hotplug)
800 * If there are kernel internal actions which can make use of some not-exact
801 * value, and reading all cpu value can be performance bottleneck in some
802 * common workload, threashold and synchonization as vmstat[] should be
805 static long mem_cgroup_read_stat(struct mem_cgroup
*memcg
,
806 enum mem_cgroup_stat_index idx
)
812 for_each_online_cpu(cpu
)
813 val
+= per_cpu(memcg
->stat
->count
[idx
], cpu
);
814 #ifdef CONFIG_HOTPLUG_CPU
815 spin_lock(&memcg
->pcp_counter_lock
);
816 val
+= memcg
->nocpu_base
.count
[idx
];
817 spin_unlock(&memcg
->pcp_counter_lock
);
823 static unsigned long mem_cgroup_read_events(struct mem_cgroup
*memcg
,
824 enum mem_cgroup_events_index idx
)
826 unsigned long val
= 0;
830 for_each_online_cpu(cpu
)
831 val
+= per_cpu(memcg
->stat
->events
[idx
], cpu
);
832 #ifdef CONFIG_HOTPLUG_CPU
833 spin_lock(&memcg
->pcp_counter_lock
);
834 val
+= memcg
->nocpu_base
.events
[idx
];
835 spin_unlock(&memcg
->pcp_counter_lock
);
841 static void mem_cgroup_charge_statistics(struct mem_cgroup
*memcg
,
846 * Here, RSS means 'mapped anon' and anon's SwapCache. Shmem/tmpfs is
847 * counted as CACHE even if it's on ANON LRU.
850 __this_cpu_add(memcg
->stat
->count
[MEM_CGROUP_STAT_RSS
],
853 __this_cpu_add(memcg
->stat
->count
[MEM_CGROUP_STAT_CACHE
],
856 if (PageTransHuge(page
))
857 __this_cpu_add(memcg
->stat
->count
[MEM_CGROUP_STAT_RSS_HUGE
],
860 /* pagein of a big page is an event. So, ignore page size */
862 __this_cpu_inc(memcg
->stat
->events
[MEM_CGROUP_EVENTS_PGPGIN
]);
864 __this_cpu_inc(memcg
->stat
->events
[MEM_CGROUP_EVENTS_PGPGOUT
]);
865 nr_pages
= -nr_pages
; /* for event */
868 __this_cpu_add(memcg
->stat
->nr_page_events
, nr_pages
);
871 unsigned long mem_cgroup_get_lru_size(struct lruvec
*lruvec
, enum lru_list lru
)
873 struct mem_cgroup_per_zone
*mz
;
875 mz
= container_of(lruvec
, struct mem_cgroup_per_zone
, lruvec
);
876 return mz
->lru_size
[lru
];
879 static unsigned long mem_cgroup_node_nr_lru_pages(struct mem_cgroup
*memcg
,
881 unsigned int lru_mask
)
883 unsigned long nr
= 0;
886 VM_BUG_ON((unsigned)nid
>= nr_node_ids
);
888 for (zid
= 0; zid
< MAX_NR_ZONES
; zid
++) {
889 struct mem_cgroup_per_zone
*mz
;
893 if (!(BIT(lru
) & lru_mask
))
895 mz
= &memcg
->nodeinfo
[nid
]->zoneinfo
[zid
];
896 nr
+= mz
->lru_size
[lru
];
902 static unsigned long mem_cgroup_nr_lru_pages(struct mem_cgroup
*memcg
,
903 unsigned int lru_mask
)
905 unsigned long nr
= 0;
908 for_each_node_state(nid
, N_MEMORY
)
909 nr
+= mem_cgroup_node_nr_lru_pages(memcg
, nid
, lru_mask
);
913 static bool mem_cgroup_event_ratelimit(struct mem_cgroup
*memcg
,
914 enum mem_cgroup_events_target target
)
916 unsigned long val
, next
;
918 val
= __this_cpu_read(memcg
->stat
->nr_page_events
);
919 next
= __this_cpu_read(memcg
->stat
->targets
[target
]);
920 /* from time_after() in jiffies.h */
921 if ((long)next
- (long)val
< 0) {
923 case MEM_CGROUP_TARGET_THRESH
:
924 next
= val
+ THRESHOLDS_EVENTS_TARGET
;
926 case MEM_CGROUP_TARGET_SOFTLIMIT
:
927 next
= val
+ SOFTLIMIT_EVENTS_TARGET
;
929 case MEM_CGROUP_TARGET_NUMAINFO
:
930 next
= val
+ NUMAINFO_EVENTS_TARGET
;
935 __this_cpu_write(memcg
->stat
->targets
[target
], next
);
942 * Check events in order.
945 static void memcg_check_events(struct mem_cgroup
*memcg
, struct page
*page
)
947 /* threshold event is triggered in finer grain than soft limit */
948 if (unlikely(mem_cgroup_event_ratelimit(memcg
,
949 MEM_CGROUP_TARGET_THRESH
))) {
951 bool do_numainfo __maybe_unused
;
953 do_softlimit
= mem_cgroup_event_ratelimit(memcg
,
954 MEM_CGROUP_TARGET_SOFTLIMIT
);
956 do_numainfo
= mem_cgroup_event_ratelimit(memcg
,
957 MEM_CGROUP_TARGET_NUMAINFO
);
959 mem_cgroup_threshold(memcg
);
960 if (unlikely(do_softlimit
))
961 mem_cgroup_update_tree(memcg
, page
);
963 if (unlikely(do_numainfo
))
964 atomic_inc(&memcg
->numainfo_events
);
969 struct mem_cgroup
*mem_cgroup_from_task(struct task_struct
*p
)
972 * mm_update_next_owner() may clear mm->owner to NULL
973 * if it races with swapoff, page migration, etc.
974 * So this can be called with p == NULL.
979 return mem_cgroup_from_css(task_css(p
, memory_cgrp_id
));
982 static struct mem_cgroup
*get_mem_cgroup_from_mm(struct mm_struct
*mm
)
984 struct mem_cgroup
*memcg
= NULL
;
989 * Page cache insertions can happen withou an
990 * actual mm context, e.g. during disk probing
991 * on boot, loopback IO, acct() writes etc.
994 memcg
= root_mem_cgroup
;
996 memcg
= mem_cgroup_from_task(rcu_dereference(mm
->owner
));
997 if (unlikely(!memcg
))
998 memcg
= root_mem_cgroup
;
1000 } while (!css_tryget_online(&memcg
->css
));
1006 * mem_cgroup_iter - iterate over memory cgroup hierarchy
1007 * @root: hierarchy root
1008 * @prev: previously returned memcg, NULL on first invocation
1009 * @reclaim: cookie for shared reclaim walks, NULL for full walks
1011 * Returns references to children of the hierarchy below @root, or
1012 * @root itself, or %NULL after a full round-trip.
1014 * Caller must pass the return value in @prev on subsequent
1015 * invocations for reference counting, or use mem_cgroup_iter_break()
1016 * to cancel a hierarchy walk before the round-trip is complete.
1018 * Reclaimers can specify a zone and a priority level in @reclaim to
1019 * divide up the memcgs in the hierarchy among all concurrent
1020 * reclaimers operating on the same zone and priority.
1022 struct mem_cgroup
*mem_cgroup_iter(struct mem_cgroup
*root
,
1023 struct mem_cgroup
*prev
,
1024 struct mem_cgroup_reclaim_cookie
*reclaim
)
1026 struct reclaim_iter
*uninitialized_var(iter
);
1027 struct cgroup_subsys_state
*css
= NULL
;
1028 struct mem_cgroup
*memcg
= NULL
;
1029 struct mem_cgroup
*pos
= NULL
;
1031 if (mem_cgroup_disabled())
1035 root
= root_mem_cgroup
;
1037 if (prev
&& !reclaim
)
1040 if (!root
->use_hierarchy
&& root
!= root_mem_cgroup
) {
1049 struct mem_cgroup_per_zone
*mz
;
1051 mz
= mem_cgroup_zone_zoneinfo(root
, reclaim
->zone
);
1052 iter
= &mz
->iter
[reclaim
->priority
];
1054 if (prev
&& reclaim
->generation
!= iter
->generation
)
1058 pos
= ACCESS_ONCE(iter
->position
);
1060 * A racing update may change the position and
1061 * put the last reference, hence css_tryget(),
1062 * or retry to see the updated position.
1064 } while (pos
&& !css_tryget(&pos
->css
));
1071 css
= css_next_descendant_pre(css
, &root
->css
);
1074 * Reclaimers share the hierarchy walk, and a
1075 * new one might jump in right at the end of
1076 * the hierarchy - make sure they see at least
1077 * one group and restart from the beginning.
1085 * Verify the css and acquire a reference. The root
1086 * is provided by the caller, so we know it's alive
1087 * and kicking, and don't take an extra reference.
1089 memcg
= mem_cgroup_from_css(css
);
1091 if (css
== &root
->css
)
1094 if (css_tryget(css
)) {
1096 * Make sure the memcg is initialized:
1097 * mem_cgroup_css_online() orders the the
1098 * initialization against setting the flag.
1100 if (smp_load_acquire(&memcg
->initialized
))
1110 if (cmpxchg(&iter
->position
, pos
, memcg
) == pos
) {
1112 css_get(&memcg
->css
);
1118 * pairs with css_tryget when dereferencing iter->position
1127 reclaim
->generation
= iter
->generation
;
1133 if (prev
&& prev
!= root
)
1134 css_put(&prev
->css
);
1140 * mem_cgroup_iter_break - abort a hierarchy walk prematurely
1141 * @root: hierarchy root
1142 * @prev: last visited hierarchy member as returned by mem_cgroup_iter()
1144 void mem_cgroup_iter_break(struct mem_cgroup
*root
,
1145 struct mem_cgroup
*prev
)
1148 root
= root_mem_cgroup
;
1149 if (prev
&& prev
!= root
)
1150 css_put(&prev
->css
);
1154 * Iteration constructs for visiting all cgroups (under a tree). If
1155 * loops are exited prematurely (break), mem_cgroup_iter_break() must
1156 * be used for reference counting.
1158 #define for_each_mem_cgroup_tree(iter, root) \
1159 for (iter = mem_cgroup_iter(root, NULL, NULL); \
1161 iter = mem_cgroup_iter(root, iter, NULL))
1163 #define for_each_mem_cgroup(iter) \
1164 for (iter = mem_cgroup_iter(NULL, NULL, NULL); \
1166 iter = mem_cgroup_iter(NULL, iter, NULL))
1168 void __mem_cgroup_count_vm_event(struct mm_struct
*mm
, enum vm_event_item idx
)
1170 struct mem_cgroup
*memcg
;
1173 memcg
= mem_cgroup_from_task(rcu_dereference(mm
->owner
));
1174 if (unlikely(!memcg
))
1179 this_cpu_inc(memcg
->stat
->events
[MEM_CGROUP_EVENTS_PGFAULT
]);
1182 this_cpu_inc(memcg
->stat
->events
[MEM_CGROUP_EVENTS_PGMAJFAULT
]);
1190 EXPORT_SYMBOL(__mem_cgroup_count_vm_event
);
1193 * mem_cgroup_zone_lruvec - get the lru list vector for a zone and memcg
1194 * @zone: zone of the wanted lruvec
1195 * @memcg: memcg of the wanted lruvec
1197 * Returns the lru list vector holding pages for the given @zone and
1198 * @mem. This can be the global zone lruvec, if the memory controller
1201 struct lruvec
*mem_cgroup_zone_lruvec(struct zone
*zone
,
1202 struct mem_cgroup
*memcg
)
1204 struct mem_cgroup_per_zone
*mz
;
1205 struct lruvec
*lruvec
;
1207 if (mem_cgroup_disabled()) {
1208 lruvec
= &zone
->lruvec
;
1212 mz
= mem_cgroup_zone_zoneinfo(memcg
, zone
);
1213 lruvec
= &mz
->lruvec
;
1216 * Since a node can be onlined after the mem_cgroup was created,
1217 * we have to be prepared to initialize lruvec->zone here;
1218 * and if offlined then reonlined, we need to reinitialize it.
1220 if (unlikely(lruvec
->zone
!= zone
))
1221 lruvec
->zone
= zone
;
1226 * mem_cgroup_page_lruvec - return lruvec for isolating/putting an LRU page
1228 * @zone: zone of the page
1230 * This function is only safe when following the LRU page isolation
1231 * and putback protocol: the LRU lock must be held, and the page must
1232 * either be PageLRU() or the caller must have isolated/allocated it.
1234 struct lruvec
*mem_cgroup_page_lruvec(struct page
*page
, struct zone
*zone
)
1236 struct mem_cgroup_per_zone
*mz
;
1237 struct mem_cgroup
*memcg
;
1238 struct lruvec
*lruvec
;
1240 if (mem_cgroup_disabled()) {
1241 lruvec
= &zone
->lruvec
;
1245 memcg
= page
->mem_cgroup
;
1247 * Swapcache readahead pages are added to the LRU - and
1248 * possibly migrated - before they are charged.
1251 memcg
= root_mem_cgroup
;
1253 mz
= mem_cgroup_page_zoneinfo(memcg
, page
);
1254 lruvec
= &mz
->lruvec
;
1257 * Since a node can be onlined after the mem_cgroup was created,
1258 * we have to be prepared to initialize lruvec->zone here;
1259 * and if offlined then reonlined, we need to reinitialize it.
1261 if (unlikely(lruvec
->zone
!= zone
))
1262 lruvec
->zone
= zone
;
1267 * mem_cgroup_update_lru_size - account for adding or removing an lru page
1268 * @lruvec: mem_cgroup per zone lru vector
1269 * @lru: index of lru list the page is sitting on
1270 * @nr_pages: positive when adding or negative when removing
1272 * This function must be called when a page is added to or removed from an
1275 void mem_cgroup_update_lru_size(struct lruvec
*lruvec
, enum lru_list lru
,
1278 struct mem_cgroup_per_zone
*mz
;
1279 unsigned long *lru_size
;
1281 if (mem_cgroup_disabled())
1284 mz
= container_of(lruvec
, struct mem_cgroup_per_zone
, lruvec
);
1285 lru_size
= mz
->lru_size
+ lru
;
1286 *lru_size
+= nr_pages
;
1287 VM_BUG_ON((long)(*lru_size
) < 0);
1290 bool mem_cgroup_is_descendant(struct mem_cgroup
*memcg
, struct mem_cgroup
*root
)
1294 if (!root
->use_hierarchy
)
1296 return cgroup_is_descendant(memcg
->css
.cgroup
, root
->css
.cgroup
);
1299 bool task_in_mem_cgroup(struct task_struct
*task
, struct mem_cgroup
*memcg
)
1301 struct mem_cgroup
*task_memcg
;
1302 struct task_struct
*p
;
1305 p
= find_lock_task_mm(task
);
1307 task_memcg
= get_mem_cgroup_from_mm(p
->mm
);
1311 * All threads may have already detached their mm's, but the oom
1312 * killer still needs to detect if they have already been oom
1313 * killed to prevent needlessly killing additional tasks.
1316 task_memcg
= mem_cgroup_from_task(task
);
1317 css_get(&task_memcg
->css
);
1320 ret
= mem_cgroup_is_descendant(task_memcg
, memcg
);
1321 css_put(&task_memcg
->css
);
1325 int mem_cgroup_inactive_anon_is_low(struct lruvec
*lruvec
)
1327 unsigned long inactive_ratio
;
1328 unsigned long inactive
;
1329 unsigned long active
;
1332 inactive
= mem_cgroup_get_lru_size(lruvec
, LRU_INACTIVE_ANON
);
1333 active
= mem_cgroup_get_lru_size(lruvec
, LRU_ACTIVE_ANON
);
1335 gb
= (inactive
+ active
) >> (30 - PAGE_SHIFT
);
1337 inactive_ratio
= int_sqrt(10 * gb
);
1341 return inactive
* inactive_ratio
< active
;
1344 bool mem_cgroup_lruvec_online(struct lruvec
*lruvec
)
1346 struct mem_cgroup_per_zone
*mz
;
1347 struct mem_cgroup
*memcg
;
1349 if (mem_cgroup_disabled())
1352 mz
= container_of(lruvec
, struct mem_cgroup_per_zone
, lruvec
);
1355 return !!(memcg
->css
.flags
& CSS_ONLINE
);
1358 #define mem_cgroup_from_counter(counter, member) \
1359 container_of(counter, struct mem_cgroup, member)
1362 * mem_cgroup_margin - calculate chargeable space of a memory cgroup
1363 * @memcg: the memory cgroup
1365 * Returns the maximum amount of memory @mem can be charged with, in
1368 static unsigned long mem_cgroup_margin(struct mem_cgroup
*memcg
)
1370 unsigned long margin
= 0;
1371 unsigned long count
;
1372 unsigned long limit
;
1374 count
= page_counter_read(&memcg
->memory
);
1375 limit
= ACCESS_ONCE(memcg
->memory
.limit
);
1377 margin
= limit
- count
;
1379 if (do_swap_account
) {
1380 count
= page_counter_read(&memcg
->memsw
);
1381 limit
= ACCESS_ONCE(memcg
->memsw
.limit
);
1383 margin
= min(margin
, limit
- count
);
1389 int mem_cgroup_swappiness(struct mem_cgroup
*memcg
)
1392 if (mem_cgroup_disabled() || !memcg
->css
.parent
)
1393 return vm_swappiness
;
1395 return memcg
->swappiness
;
1399 * A routine for checking "mem" is under move_account() or not.
1401 * Checking a cgroup is mc.from or mc.to or under hierarchy of
1402 * moving cgroups. This is for waiting at high-memory pressure
1405 static bool mem_cgroup_under_move(struct mem_cgroup
*memcg
)
1407 struct mem_cgroup
*from
;
1408 struct mem_cgroup
*to
;
1411 * Unlike task_move routines, we access mc.to, mc.from not under
1412 * mutual exclusion by cgroup_mutex. Here, we take spinlock instead.
1414 spin_lock(&mc
.lock
);
1420 ret
= mem_cgroup_is_descendant(from
, memcg
) ||
1421 mem_cgroup_is_descendant(to
, memcg
);
1423 spin_unlock(&mc
.lock
);
1427 static bool mem_cgroup_wait_acct_move(struct mem_cgroup
*memcg
)
1429 if (mc
.moving_task
&& current
!= mc
.moving_task
) {
1430 if (mem_cgroup_under_move(memcg
)) {
1432 prepare_to_wait(&mc
.waitq
, &wait
, TASK_INTERRUPTIBLE
);
1433 /* moving charge context might have finished. */
1436 finish_wait(&mc
.waitq
, &wait
);
1443 #define K(x) ((x) << (PAGE_SHIFT-10))
1445 * mem_cgroup_print_oom_info: Print OOM information relevant to memory controller.
1446 * @memcg: The memory cgroup that went over limit
1447 * @p: Task that is going to be killed
1449 * NOTE: @memcg and @p's mem_cgroup can be different when hierarchy is
1452 void mem_cgroup_print_oom_info(struct mem_cgroup
*memcg
, struct task_struct
*p
)
1454 /* oom_info_lock ensures that parallel ooms do not interleave */
1455 static DEFINE_MUTEX(oom_info_lock
);
1456 struct mem_cgroup
*iter
;
1462 mutex_lock(&oom_info_lock
);
1465 pr_info("Task in ");
1466 pr_cont_cgroup_path(task_cgroup(p
, memory_cgrp_id
));
1467 pr_cont(" killed as a result of limit of ");
1468 pr_cont_cgroup_path(memcg
->css
.cgroup
);
1473 pr_info("memory: usage %llukB, limit %llukB, failcnt %lu\n",
1474 K((u64
)page_counter_read(&memcg
->memory
)),
1475 K((u64
)memcg
->memory
.limit
), memcg
->memory
.failcnt
);
1476 pr_info("memory+swap: usage %llukB, limit %llukB, failcnt %lu\n",
1477 K((u64
)page_counter_read(&memcg
->memsw
)),
1478 K((u64
)memcg
->memsw
.limit
), memcg
->memsw
.failcnt
);
1479 pr_info("kmem: usage %llukB, limit %llukB, failcnt %lu\n",
1480 K((u64
)page_counter_read(&memcg
->kmem
)),
1481 K((u64
)memcg
->kmem
.limit
), memcg
->kmem
.failcnt
);
1483 for_each_mem_cgroup_tree(iter
, memcg
) {
1484 pr_info("Memory cgroup stats for ");
1485 pr_cont_cgroup_path(iter
->css
.cgroup
);
1488 for (i
= 0; i
< MEM_CGROUP_STAT_NSTATS
; i
++) {
1489 if (i
== MEM_CGROUP_STAT_SWAP
&& !do_swap_account
)
1491 pr_cont(" %s:%ldKB", mem_cgroup_stat_names
[i
],
1492 K(mem_cgroup_read_stat(iter
, i
)));
1495 for (i
= 0; i
< NR_LRU_LISTS
; i
++)
1496 pr_cont(" %s:%luKB", mem_cgroup_lru_names
[i
],
1497 K(mem_cgroup_nr_lru_pages(iter
, BIT(i
))));
1501 mutex_unlock(&oom_info_lock
);
1505 * This function returns the number of memcg under hierarchy tree. Returns
1506 * 1(self count) if no children.
1508 static int mem_cgroup_count_children(struct mem_cgroup
*memcg
)
1511 struct mem_cgroup
*iter
;
1513 for_each_mem_cgroup_tree(iter
, memcg
)
1519 * Return the memory (and swap, if configured) limit for a memcg.
1521 static unsigned long mem_cgroup_get_limit(struct mem_cgroup
*memcg
)
1523 unsigned long limit
;
1525 limit
= memcg
->memory
.limit
;
1526 if (mem_cgroup_swappiness(memcg
)) {
1527 unsigned long memsw_limit
;
1529 memsw_limit
= memcg
->memsw
.limit
;
1530 limit
= min(limit
+ total_swap_pages
, memsw_limit
);
1535 static void mem_cgroup_out_of_memory(struct mem_cgroup
*memcg
, gfp_t gfp_mask
,
1538 struct mem_cgroup
*iter
;
1539 unsigned long chosen_points
= 0;
1540 unsigned long totalpages
;
1541 unsigned int points
= 0;
1542 struct task_struct
*chosen
= NULL
;
1545 * If current has a pending SIGKILL or is exiting, then automatically
1546 * select it. The goal is to allow it to allocate so that it may
1547 * quickly exit and free its memory.
1549 if (fatal_signal_pending(current
) || task_will_free_mem(current
)) {
1550 mark_tsk_oom_victim(current
);
1554 check_panic_on_oom(CONSTRAINT_MEMCG
, gfp_mask
, order
, NULL
);
1555 totalpages
= mem_cgroup_get_limit(memcg
) ? : 1;
1556 for_each_mem_cgroup_tree(iter
, memcg
) {
1557 struct css_task_iter it
;
1558 struct task_struct
*task
;
1560 css_task_iter_start(&iter
->css
, &it
);
1561 while ((task
= css_task_iter_next(&it
))) {
1562 switch (oom_scan_process_thread(task
, totalpages
, NULL
,
1564 case OOM_SCAN_SELECT
:
1566 put_task_struct(chosen
);
1568 chosen_points
= ULONG_MAX
;
1569 get_task_struct(chosen
);
1571 case OOM_SCAN_CONTINUE
:
1573 case OOM_SCAN_ABORT
:
1574 css_task_iter_end(&it
);
1575 mem_cgroup_iter_break(memcg
, iter
);
1577 put_task_struct(chosen
);
1582 points
= oom_badness(task
, memcg
, NULL
, totalpages
);
1583 if (!points
|| points
< chosen_points
)
1585 /* Prefer thread group leaders for display purposes */
1586 if (points
== chosen_points
&&
1587 thread_group_leader(chosen
))
1591 put_task_struct(chosen
);
1593 chosen_points
= points
;
1594 get_task_struct(chosen
);
1596 css_task_iter_end(&it
);
1601 points
= chosen_points
* 1000 / totalpages
;
1602 oom_kill_process(chosen
, gfp_mask
, order
, points
, totalpages
, memcg
,
1603 NULL
, "Memory cgroup out of memory");
1606 #if MAX_NUMNODES > 1
1609 * test_mem_cgroup_node_reclaimable
1610 * @memcg: the target memcg
1611 * @nid: the node ID to be checked.
1612 * @noswap : specify true here if the user wants flle only information.
1614 * This function returns whether the specified memcg contains any
1615 * reclaimable pages on a node. Returns true if there are any reclaimable
1616 * pages in the node.
1618 static bool test_mem_cgroup_node_reclaimable(struct mem_cgroup
*memcg
,
1619 int nid
, bool noswap
)
1621 if (mem_cgroup_node_nr_lru_pages(memcg
, nid
, LRU_ALL_FILE
))
1623 if (noswap
|| !total_swap_pages
)
1625 if (mem_cgroup_node_nr_lru_pages(memcg
, nid
, LRU_ALL_ANON
))
1632 * Always updating the nodemask is not very good - even if we have an empty
1633 * list or the wrong list here, we can start from some node and traverse all
1634 * nodes based on the zonelist. So update the list loosely once per 10 secs.
1637 static void mem_cgroup_may_update_nodemask(struct mem_cgroup
*memcg
)
1641 * numainfo_events > 0 means there was at least NUMAINFO_EVENTS_TARGET
1642 * pagein/pageout changes since the last update.
1644 if (!atomic_read(&memcg
->numainfo_events
))
1646 if (atomic_inc_return(&memcg
->numainfo_updating
) > 1)
1649 /* make a nodemask where this memcg uses memory from */
1650 memcg
->scan_nodes
= node_states
[N_MEMORY
];
1652 for_each_node_mask(nid
, node_states
[N_MEMORY
]) {
1654 if (!test_mem_cgroup_node_reclaimable(memcg
, nid
, false))
1655 node_clear(nid
, memcg
->scan_nodes
);
1658 atomic_set(&memcg
->numainfo_events
, 0);
1659 atomic_set(&memcg
->numainfo_updating
, 0);
1663 * Selecting a node where we start reclaim from. Because what we need is just
1664 * reducing usage counter, start from anywhere is O,K. Considering
1665 * memory reclaim from current node, there are pros. and cons.
1667 * Freeing memory from current node means freeing memory from a node which
1668 * we'll use or we've used. So, it may make LRU bad. And if several threads
1669 * hit limits, it will see a contention on a node. But freeing from remote
1670 * node means more costs for memory reclaim because of memory latency.
1672 * Now, we use round-robin. Better algorithm is welcomed.
1674 int mem_cgroup_select_victim_node(struct mem_cgroup
*memcg
)
1678 mem_cgroup_may_update_nodemask(memcg
);
1679 node
= memcg
->last_scanned_node
;
1681 node
= next_node(node
, memcg
->scan_nodes
);
1682 if (node
== MAX_NUMNODES
)
1683 node
= first_node(memcg
->scan_nodes
);
1685 * We call this when we hit limit, not when pages are added to LRU.
1686 * No LRU may hold pages because all pages are UNEVICTABLE or
1687 * memcg is too small and all pages are not on LRU. In that case,
1688 * we use curret node.
1690 if (unlikely(node
== MAX_NUMNODES
))
1691 node
= numa_node_id();
1693 memcg
->last_scanned_node
= node
;
1697 int mem_cgroup_select_victim_node(struct mem_cgroup
*memcg
)
1703 static int mem_cgroup_soft_reclaim(struct mem_cgroup
*root_memcg
,
1706 unsigned long *total_scanned
)
1708 struct mem_cgroup
*victim
= NULL
;
1711 unsigned long excess
;
1712 unsigned long nr_scanned
;
1713 struct mem_cgroup_reclaim_cookie reclaim
= {
1718 excess
= soft_limit_excess(root_memcg
);
1721 victim
= mem_cgroup_iter(root_memcg
, victim
, &reclaim
);
1726 * If we have not been able to reclaim
1727 * anything, it might because there are
1728 * no reclaimable pages under this hierarchy
1733 * We want to do more targeted reclaim.
1734 * excess >> 2 is not to excessive so as to
1735 * reclaim too much, nor too less that we keep
1736 * coming back to reclaim from this cgroup
1738 if (total
>= (excess
>> 2) ||
1739 (loop
> MEM_CGROUP_MAX_RECLAIM_LOOPS
))
1744 total
+= mem_cgroup_shrink_node_zone(victim
, gfp_mask
, false,
1746 *total_scanned
+= nr_scanned
;
1747 if (!soft_limit_excess(root_memcg
))
1750 mem_cgroup_iter_break(root_memcg
, victim
);
1754 #ifdef CONFIG_LOCKDEP
1755 static struct lockdep_map memcg_oom_lock_dep_map
= {
1756 .name
= "memcg_oom_lock",
1760 static DEFINE_SPINLOCK(memcg_oom_lock
);
1763 * Check OOM-Killer is already running under our hierarchy.
1764 * If someone is running, return false.
1766 static bool mem_cgroup_oom_trylock(struct mem_cgroup
*memcg
)
1768 struct mem_cgroup
*iter
, *failed
= NULL
;
1770 spin_lock(&memcg_oom_lock
);
1772 for_each_mem_cgroup_tree(iter
, memcg
) {
1773 if (iter
->oom_lock
) {
1775 * this subtree of our hierarchy is already locked
1776 * so we cannot give a lock.
1779 mem_cgroup_iter_break(memcg
, iter
);
1782 iter
->oom_lock
= true;
1787 * OK, we failed to lock the whole subtree so we have
1788 * to clean up what we set up to the failing subtree
1790 for_each_mem_cgroup_tree(iter
, memcg
) {
1791 if (iter
== failed
) {
1792 mem_cgroup_iter_break(memcg
, iter
);
1795 iter
->oom_lock
= false;
1798 mutex_acquire(&memcg_oom_lock_dep_map
, 0, 1, _RET_IP_
);
1800 spin_unlock(&memcg_oom_lock
);
1805 static void mem_cgroup_oom_unlock(struct mem_cgroup
*memcg
)
1807 struct mem_cgroup
*iter
;
1809 spin_lock(&memcg_oom_lock
);
1810 mutex_release(&memcg_oom_lock_dep_map
, 1, _RET_IP_
);
1811 for_each_mem_cgroup_tree(iter
, memcg
)
1812 iter
->oom_lock
= false;
1813 spin_unlock(&memcg_oom_lock
);
1816 static void mem_cgroup_mark_under_oom(struct mem_cgroup
*memcg
)
1818 struct mem_cgroup
*iter
;
1820 for_each_mem_cgroup_tree(iter
, memcg
)
1821 atomic_inc(&iter
->under_oom
);
1824 static void mem_cgroup_unmark_under_oom(struct mem_cgroup
*memcg
)
1826 struct mem_cgroup
*iter
;
1829 * When a new child is created while the hierarchy is under oom,
1830 * mem_cgroup_oom_lock() may not be called. We have to use
1831 * atomic_add_unless() here.
1833 for_each_mem_cgroup_tree(iter
, memcg
)
1834 atomic_add_unless(&iter
->under_oom
, -1, 0);
1837 static DECLARE_WAIT_QUEUE_HEAD(memcg_oom_waitq
);
1839 struct oom_wait_info
{
1840 struct mem_cgroup
*memcg
;
1844 static int memcg_oom_wake_function(wait_queue_t
*wait
,
1845 unsigned mode
, int sync
, void *arg
)
1847 struct mem_cgroup
*wake_memcg
= (struct mem_cgroup
*)arg
;
1848 struct mem_cgroup
*oom_wait_memcg
;
1849 struct oom_wait_info
*oom_wait_info
;
1851 oom_wait_info
= container_of(wait
, struct oom_wait_info
, wait
);
1852 oom_wait_memcg
= oom_wait_info
->memcg
;
1854 if (!mem_cgroup_is_descendant(wake_memcg
, oom_wait_memcg
) &&
1855 !mem_cgroup_is_descendant(oom_wait_memcg
, wake_memcg
))
1857 return autoremove_wake_function(wait
, mode
, sync
, arg
);
1860 static void memcg_wakeup_oom(struct mem_cgroup
*memcg
)
1862 atomic_inc(&memcg
->oom_wakeups
);
1863 /* for filtering, pass "memcg" as argument. */
1864 __wake_up(&memcg_oom_waitq
, TASK_NORMAL
, 0, memcg
);
1867 static void memcg_oom_recover(struct mem_cgroup
*memcg
)
1869 if (memcg
&& atomic_read(&memcg
->under_oom
))
1870 memcg_wakeup_oom(memcg
);
1873 static void mem_cgroup_oom(struct mem_cgroup
*memcg
, gfp_t mask
, int order
)
1875 if (!current
->memcg_oom
.may_oom
)
1878 * We are in the middle of the charge context here, so we
1879 * don't want to block when potentially sitting on a callstack
1880 * that holds all kinds of filesystem and mm locks.
1882 * Also, the caller may handle a failed allocation gracefully
1883 * (like optional page cache readahead) and so an OOM killer
1884 * invocation might not even be necessary.
1886 * That's why we don't do anything here except remember the
1887 * OOM context and then deal with it at the end of the page
1888 * fault when the stack is unwound, the locks are released,
1889 * and when we know whether the fault was overall successful.
1891 css_get(&memcg
->css
);
1892 current
->memcg_oom
.memcg
= memcg
;
1893 current
->memcg_oom
.gfp_mask
= mask
;
1894 current
->memcg_oom
.order
= order
;
1898 * mem_cgroup_oom_synchronize - complete memcg OOM handling
1899 * @handle: actually kill/wait or just clean up the OOM state
1901 * This has to be called at the end of a page fault if the memcg OOM
1902 * handler was enabled.
1904 * Memcg supports userspace OOM handling where failed allocations must
1905 * sleep on a waitqueue until the userspace task resolves the
1906 * situation. Sleeping directly in the charge context with all kinds
1907 * of locks held is not a good idea, instead we remember an OOM state
1908 * in the task and mem_cgroup_oom_synchronize() has to be called at
1909 * the end of the page fault to complete the OOM handling.
1911 * Returns %true if an ongoing memcg OOM situation was detected and
1912 * completed, %false otherwise.
1914 bool mem_cgroup_oom_synchronize(bool handle
)
1916 struct mem_cgroup
*memcg
= current
->memcg_oom
.memcg
;
1917 struct oom_wait_info owait
;
1920 /* OOM is global, do not handle */
1924 if (!handle
|| oom_killer_disabled
)
1927 owait
.memcg
= memcg
;
1928 owait
.wait
.flags
= 0;
1929 owait
.wait
.func
= memcg_oom_wake_function
;
1930 owait
.wait
.private = current
;
1931 INIT_LIST_HEAD(&owait
.wait
.task_list
);
1933 prepare_to_wait(&memcg_oom_waitq
, &owait
.wait
, TASK_KILLABLE
);
1934 mem_cgroup_mark_under_oom(memcg
);
1936 locked
= mem_cgroup_oom_trylock(memcg
);
1939 mem_cgroup_oom_notify(memcg
);
1941 if (locked
&& !memcg
->oom_kill_disable
) {
1942 mem_cgroup_unmark_under_oom(memcg
);
1943 finish_wait(&memcg_oom_waitq
, &owait
.wait
);
1944 mem_cgroup_out_of_memory(memcg
, current
->memcg_oom
.gfp_mask
,
1945 current
->memcg_oom
.order
);
1948 mem_cgroup_unmark_under_oom(memcg
);
1949 finish_wait(&memcg_oom_waitq
, &owait
.wait
);
1953 mem_cgroup_oom_unlock(memcg
);
1955 * There is no guarantee that an OOM-lock contender
1956 * sees the wakeups triggered by the OOM kill
1957 * uncharges. Wake any sleepers explicitely.
1959 memcg_oom_recover(memcg
);
1962 current
->memcg_oom
.memcg
= NULL
;
1963 css_put(&memcg
->css
);
1968 * mem_cgroup_begin_page_stat - begin a page state statistics transaction
1969 * @page: page that is going to change accounted state
1971 * This function must mark the beginning of an accounted page state
1972 * change to prevent double accounting when the page is concurrently
1973 * being moved to another memcg:
1975 * memcg = mem_cgroup_begin_page_stat(page);
1976 * if (TestClearPageState(page))
1977 * mem_cgroup_update_page_stat(memcg, state, -1);
1978 * mem_cgroup_end_page_stat(memcg);
1980 struct mem_cgroup
*mem_cgroup_begin_page_stat(struct page
*page
)
1982 struct mem_cgroup
*memcg
;
1983 unsigned long flags
;
1986 * The RCU lock is held throughout the transaction. The fast
1987 * path can get away without acquiring the memcg->move_lock
1988 * because page moving starts with an RCU grace period.
1990 * The RCU lock also protects the memcg from being freed when
1991 * the page state that is going to change is the only thing
1992 * preventing the page from being uncharged.
1993 * E.g. end-writeback clearing PageWriteback(), which allows
1994 * migration to go ahead and uncharge the page before the
1995 * account transaction might be complete.
1999 if (mem_cgroup_disabled())
2002 memcg
= page
->mem_cgroup
;
2003 if (unlikely(!memcg
))
2006 if (atomic_read(&memcg
->moving_account
) <= 0)
2009 spin_lock_irqsave(&memcg
->move_lock
, flags
);
2010 if (memcg
!= page
->mem_cgroup
) {
2011 spin_unlock_irqrestore(&memcg
->move_lock
, flags
);
2016 * When charge migration first begins, we can have locked and
2017 * unlocked page stat updates happening concurrently. Track
2018 * the task who has the lock for mem_cgroup_end_page_stat().
2020 memcg
->move_lock_task
= current
;
2021 memcg
->move_lock_flags
= flags
;
2027 * mem_cgroup_end_page_stat - finish a page state statistics transaction
2028 * @memcg: the memcg that was accounted against
2030 void mem_cgroup_end_page_stat(struct mem_cgroup
*memcg
)
2032 if (memcg
&& memcg
->move_lock_task
== current
) {
2033 unsigned long flags
= memcg
->move_lock_flags
;
2035 memcg
->move_lock_task
= NULL
;
2036 memcg
->move_lock_flags
= 0;
2038 spin_unlock_irqrestore(&memcg
->move_lock
, flags
);
2045 * mem_cgroup_update_page_stat - update page state statistics
2046 * @memcg: memcg to account against
2047 * @idx: page state item to account
2048 * @val: number of pages (positive or negative)
2050 * See mem_cgroup_begin_page_stat() for locking requirements.
2052 void mem_cgroup_update_page_stat(struct mem_cgroup
*memcg
,
2053 enum mem_cgroup_stat_index idx
, int val
)
2055 VM_BUG_ON(!rcu_read_lock_held());
2058 this_cpu_add(memcg
->stat
->count
[idx
], val
);
2062 * size of first charge trial. "32" comes from vmscan.c's magic value.
2063 * TODO: maybe necessary to use big numbers in big irons.
2065 #define CHARGE_BATCH 32U
2066 struct memcg_stock_pcp
{
2067 struct mem_cgroup
*cached
; /* this never be root cgroup */
2068 unsigned int nr_pages
;
2069 struct work_struct work
;
2070 unsigned long flags
;
2071 #define FLUSHING_CACHED_CHARGE 0
2073 static DEFINE_PER_CPU(struct memcg_stock_pcp
, memcg_stock
);
2074 static DEFINE_MUTEX(percpu_charge_mutex
);
2077 * consume_stock: Try to consume stocked charge on this cpu.
2078 * @memcg: memcg to consume from.
2079 * @nr_pages: how many pages to charge.
2081 * The charges will only happen if @memcg matches the current cpu's memcg
2082 * stock, and at least @nr_pages are available in that stock. Failure to
2083 * service an allocation will refill the stock.
2085 * returns true if successful, false otherwise.
2087 static bool consume_stock(struct mem_cgroup
*memcg
, unsigned int nr_pages
)
2089 struct memcg_stock_pcp
*stock
;
2092 if (nr_pages
> CHARGE_BATCH
)
2095 stock
= &get_cpu_var(memcg_stock
);
2096 if (memcg
== stock
->cached
&& stock
->nr_pages
>= nr_pages
) {
2097 stock
->nr_pages
-= nr_pages
;
2100 put_cpu_var(memcg_stock
);
2105 * Returns stocks cached in percpu and reset cached information.
2107 static void drain_stock(struct memcg_stock_pcp
*stock
)
2109 struct mem_cgroup
*old
= stock
->cached
;
2111 if (stock
->nr_pages
) {
2112 page_counter_uncharge(&old
->memory
, stock
->nr_pages
);
2113 if (do_swap_account
)
2114 page_counter_uncharge(&old
->memsw
, stock
->nr_pages
);
2115 css_put_many(&old
->css
, stock
->nr_pages
);
2116 stock
->nr_pages
= 0;
2118 stock
->cached
= NULL
;
2122 * This must be called under preempt disabled or must be called by
2123 * a thread which is pinned to local cpu.
2125 static void drain_local_stock(struct work_struct
*dummy
)
2127 struct memcg_stock_pcp
*stock
= this_cpu_ptr(&memcg_stock
);
2129 clear_bit(FLUSHING_CACHED_CHARGE
, &stock
->flags
);
2133 * Cache charges(val) to local per_cpu area.
2134 * This will be consumed by consume_stock() function, later.
2136 static void refill_stock(struct mem_cgroup
*memcg
, unsigned int nr_pages
)
2138 struct memcg_stock_pcp
*stock
= &get_cpu_var(memcg_stock
);
2140 if (stock
->cached
!= memcg
) { /* reset if necessary */
2142 stock
->cached
= memcg
;
2144 stock
->nr_pages
+= nr_pages
;
2145 put_cpu_var(memcg_stock
);
2149 * Drains all per-CPU charge caches for given root_memcg resp. subtree
2150 * of the hierarchy under it.
2152 static void drain_all_stock(struct mem_cgroup
*root_memcg
)
2156 /* If someone's already draining, avoid adding running more workers. */
2157 if (!mutex_trylock(&percpu_charge_mutex
))
2159 /* Notify other cpus that system-wide "drain" is running */
2162 for_each_online_cpu(cpu
) {
2163 struct memcg_stock_pcp
*stock
= &per_cpu(memcg_stock
, cpu
);
2164 struct mem_cgroup
*memcg
;
2166 memcg
= stock
->cached
;
2167 if (!memcg
|| !stock
->nr_pages
)
2169 if (!mem_cgroup_is_descendant(memcg
, root_memcg
))
2171 if (!test_and_set_bit(FLUSHING_CACHED_CHARGE
, &stock
->flags
)) {
2173 drain_local_stock(&stock
->work
);
2175 schedule_work_on(cpu
, &stock
->work
);
2180 mutex_unlock(&percpu_charge_mutex
);
2184 * This function drains percpu counter value from DEAD cpu and
2185 * move it to local cpu. Note that this function can be preempted.
2187 static void mem_cgroup_drain_pcp_counter(struct mem_cgroup
*memcg
, int cpu
)
2191 spin_lock(&memcg
->pcp_counter_lock
);
2192 for (i
= 0; i
< MEM_CGROUP_STAT_NSTATS
; i
++) {
2193 long x
= per_cpu(memcg
->stat
->count
[i
], cpu
);
2195 per_cpu(memcg
->stat
->count
[i
], cpu
) = 0;
2196 memcg
->nocpu_base
.count
[i
] += x
;
2198 for (i
= 0; i
< MEM_CGROUP_EVENTS_NSTATS
; i
++) {
2199 unsigned long x
= per_cpu(memcg
->stat
->events
[i
], cpu
);
2201 per_cpu(memcg
->stat
->events
[i
], cpu
) = 0;
2202 memcg
->nocpu_base
.events
[i
] += x
;
2204 spin_unlock(&memcg
->pcp_counter_lock
);
2207 static int memcg_cpu_hotplug_callback(struct notifier_block
*nb
,
2208 unsigned long action
,
2211 int cpu
= (unsigned long)hcpu
;
2212 struct memcg_stock_pcp
*stock
;
2213 struct mem_cgroup
*iter
;
2215 if (action
== CPU_ONLINE
)
2218 if (action
!= CPU_DEAD
&& action
!= CPU_DEAD_FROZEN
)
2221 for_each_mem_cgroup(iter
)
2222 mem_cgroup_drain_pcp_counter(iter
, cpu
);
2224 stock
= &per_cpu(memcg_stock
, cpu
);
2229 static int try_charge(struct mem_cgroup
*memcg
, gfp_t gfp_mask
,
2230 unsigned int nr_pages
)
2232 unsigned int batch
= max(CHARGE_BATCH
, nr_pages
);
2233 int nr_retries
= MEM_CGROUP_RECLAIM_RETRIES
;
2234 struct mem_cgroup
*mem_over_limit
;
2235 struct page_counter
*counter
;
2236 unsigned long nr_reclaimed
;
2237 bool may_swap
= true;
2238 bool drained
= false;
2241 if (mem_cgroup_is_root(memcg
))
2244 if (consume_stock(memcg
, nr_pages
))
2247 if (!do_swap_account
||
2248 !page_counter_try_charge(&memcg
->memsw
, batch
, &counter
)) {
2249 if (!page_counter_try_charge(&memcg
->memory
, batch
, &counter
))
2251 if (do_swap_account
)
2252 page_counter_uncharge(&memcg
->memsw
, batch
);
2253 mem_over_limit
= mem_cgroup_from_counter(counter
, memory
);
2255 mem_over_limit
= mem_cgroup_from_counter(counter
, memsw
);
2259 if (batch
> nr_pages
) {
2265 * Unlike in global OOM situations, memcg is not in a physical
2266 * memory shortage. Allow dying and OOM-killed tasks to
2267 * bypass the last charges so that they can exit quickly and
2268 * free their memory.
2270 if (unlikely(test_thread_flag(TIF_MEMDIE
) ||
2271 fatal_signal_pending(current
) ||
2272 current
->flags
& PF_EXITING
))
2275 if (unlikely(task_in_memcg_oom(current
)))
2278 if (!(gfp_mask
& __GFP_WAIT
))
2281 mem_cgroup_events(mem_over_limit
, MEMCG_MAX
, 1);
2283 nr_reclaimed
= try_to_free_mem_cgroup_pages(mem_over_limit
, nr_pages
,
2284 gfp_mask
, may_swap
);
2286 if (mem_cgroup_margin(mem_over_limit
) >= nr_pages
)
2290 drain_all_stock(mem_over_limit
);
2295 if (gfp_mask
& __GFP_NORETRY
)
2298 * Even though the limit is exceeded at this point, reclaim
2299 * may have been able to free some pages. Retry the charge
2300 * before killing the task.
2302 * Only for regular pages, though: huge pages are rather
2303 * unlikely to succeed so close to the limit, and we fall back
2304 * to regular pages anyway in case of failure.
2306 if (nr_reclaimed
&& nr_pages
<= (1 << PAGE_ALLOC_COSTLY_ORDER
))
2309 * At task move, charge accounts can be doubly counted. So, it's
2310 * better to wait until the end of task_move if something is going on.
2312 if (mem_cgroup_wait_acct_move(mem_over_limit
))
2318 if (gfp_mask
& __GFP_NOFAIL
)
2321 if (fatal_signal_pending(current
))
2324 mem_cgroup_events(mem_over_limit
, MEMCG_OOM
, 1);
2326 mem_cgroup_oom(mem_over_limit
, gfp_mask
, get_order(nr_pages
));
2328 if (!(gfp_mask
& __GFP_NOFAIL
))
2334 css_get_many(&memcg
->css
, batch
);
2335 if (batch
> nr_pages
)
2336 refill_stock(memcg
, batch
- nr_pages
);
2338 * If the hierarchy is above the normal consumption range,
2339 * make the charging task trim their excess contribution.
2342 if (page_counter_read(&memcg
->memory
) <= memcg
->high
)
2344 mem_cgroup_events(memcg
, MEMCG_HIGH
, 1);
2345 try_to_free_mem_cgroup_pages(memcg
, nr_pages
, gfp_mask
, true);
2346 } while ((memcg
= parent_mem_cgroup(memcg
)));
2351 static void cancel_charge(struct mem_cgroup
*memcg
, unsigned int nr_pages
)
2353 if (mem_cgroup_is_root(memcg
))
2356 page_counter_uncharge(&memcg
->memory
, nr_pages
);
2357 if (do_swap_account
)
2358 page_counter_uncharge(&memcg
->memsw
, nr_pages
);
2360 css_put_many(&memcg
->css
, nr_pages
);
2364 * A helper function to get mem_cgroup from ID. must be called under
2365 * rcu_read_lock(). The caller is responsible for calling
2366 * css_tryget_online() if the mem_cgroup is used for charging. (dropping
2367 * refcnt from swap can be called against removed memcg.)
2369 static struct mem_cgroup
*mem_cgroup_lookup(unsigned short id
)
2371 /* ID 0 is unused ID */
2374 return mem_cgroup_from_id(id
);
2378 * try_get_mem_cgroup_from_page - look up page's memcg association
2381 * Look up, get a css reference, and return the memcg that owns @page.
2383 * The page must be locked to prevent racing with swap-in and page
2384 * cache charges. If coming from an unlocked page table, the caller
2385 * must ensure the page is on the LRU or this can race with charging.
2387 struct mem_cgroup
*try_get_mem_cgroup_from_page(struct page
*page
)
2389 struct mem_cgroup
*memcg
;
2393 VM_BUG_ON_PAGE(!PageLocked(page
), page
);
2395 memcg
= page
->mem_cgroup
;
2397 if (!css_tryget_online(&memcg
->css
))
2399 } else if (PageSwapCache(page
)) {
2400 ent
.val
= page_private(page
);
2401 id
= lookup_swap_cgroup_id(ent
);
2403 memcg
= mem_cgroup_lookup(id
);
2404 if (memcg
&& !css_tryget_online(&memcg
->css
))
2411 static void lock_page_lru(struct page
*page
, int *isolated
)
2413 struct zone
*zone
= page_zone(page
);
2415 spin_lock_irq(&zone
->lru_lock
);
2416 if (PageLRU(page
)) {
2417 struct lruvec
*lruvec
;
2419 lruvec
= mem_cgroup_page_lruvec(page
, zone
);
2421 del_page_from_lru_list(page
, lruvec
, page_lru(page
));
2427 static void unlock_page_lru(struct page
*page
, int isolated
)
2429 struct zone
*zone
= page_zone(page
);
2432 struct lruvec
*lruvec
;
2434 lruvec
= mem_cgroup_page_lruvec(page
, zone
);
2435 VM_BUG_ON_PAGE(PageLRU(page
), page
);
2437 add_page_to_lru_list(page
, lruvec
, page_lru(page
));
2439 spin_unlock_irq(&zone
->lru_lock
);
2442 static void commit_charge(struct page
*page
, struct mem_cgroup
*memcg
,
2447 VM_BUG_ON_PAGE(page
->mem_cgroup
, page
);
2450 * In some cases, SwapCache and FUSE(splice_buf->radixtree), the page
2451 * may already be on some other mem_cgroup's LRU. Take care of it.
2454 lock_page_lru(page
, &isolated
);
2457 * Nobody should be changing or seriously looking at
2458 * page->mem_cgroup at this point:
2460 * - the page is uncharged
2462 * - the page is off-LRU
2464 * - an anonymous fault has exclusive page access, except for
2465 * a locked page table
2467 * - a page cache insertion, a swapin fault, or a migration
2468 * have the page locked
2470 page
->mem_cgroup
= memcg
;
2473 unlock_page_lru(page
, isolated
);
2476 #ifdef CONFIG_MEMCG_KMEM
2477 int memcg_charge_kmem(struct mem_cgroup
*memcg
, gfp_t gfp
,
2478 unsigned long nr_pages
)
2480 struct page_counter
*counter
;
2483 ret
= page_counter_try_charge(&memcg
->kmem
, nr_pages
, &counter
);
2487 ret
= try_charge(memcg
, gfp
, nr_pages
);
2488 if (ret
== -EINTR
) {
2490 * try_charge() chose to bypass to root due to OOM kill or
2491 * fatal signal. Since our only options are to either fail
2492 * the allocation or charge it to this cgroup, do it as a
2493 * temporary condition. But we can't fail. From a kmem/slab
2494 * perspective, the cache has already been selected, by
2495 * mem_cgroup_kmem_get_cache(), so it is too late to change
2498 * This condition will only trigger if the task entered
2499 * memcg_charge_kmem in a sane state, but was OOM-killed
2500 * during try_charge() above. Tasks that were already dying
2501 * when the allocation triggers should have been already
2502 * directed to the root cgroup in memcontrol.h
2504 page_counter_charge(&memcg
->memory
, nr_pages
);
2505 if (do_swap_account
)
2506 page_counter_charge(&memcg
->memsw
, nr_pages
);
2507 css_get_many(&memcg
->css
, nr_pages
);
2510 page_counter_uncharge(&memcg
->kmem
, nr_pages
);
2515 void memcg_uncharge_kmem(struct mem_cgroup
*memcg
, unsigned long nr_pages
)
2517 page_counter_uncharge(&memcg
->memory
, nr_pages
);
2518 if (do_swap_account
)
2519 page_counter_uncharge(&memcg
->memsw
, nr_pages
);
2521 page_counter_uncharge(&memcg
->kmem
, nr_pages
);
2523 css_put_many(&memcg
->css
, nr_pages
);
2527 * helper for acessing a memcg's index. It will be used as an index in the
2528 * child cache array in kmem_cache, and also to derive its name. This function
2529 * will return -1 when this is not a kmem-limited memcg.
2531 int memcg_cache_id(struct mem_cgroup
*memcg
)
2533 return memcg
? memcg
->kmemcg_id
: -1;
2536 static int memcg_alloc_cache_id(void)
2541 id
= ida_simple_get(&kmem_limited_groups
,
2542 0, MEMCG_CACHES_MAX_SIZE
, GFP_KERNEL
);
2546 if (id
< memcg_limited_groups_array_size
)
2550 * There's no space for the new id in memcg_caches arrays,
2551 * so we have to grow them.
2554 size
= 2 * (id
+ 1);
2555 if (size
< MEMCG_CACHES_MIN_SIZE
)
2556 size
= MEMCG_CACHES_MIN_SIZE
;
2557 else if (size
> MEMCG_CACHES_MAX_SIZE
)
2558 size
= MEMCG_CACHES_MAX_SIZE
;
2560 err
= memcg_update_all_caches(size
);
2562 ida_simple_remove(&kmem_limited_groups
, id
);
2568 static void memcg_free_cache_id(int id
)
2570 ida_simple_remove(&kmem_limited_groups
, id
);
2574 * We should update the current array size iff all caches updates succeed. This
2575 * can only be done from the slab side. The slab mutex needs to be held when
2578 void memcg_update_array_size(int num
)
2580 memcg_limited_groups_array_size
= num
;
2583 struct memcg_kmem_cache_create_work
{
2584 struct mem_cgroup
*memcg
;
2585 struct kmem_cache
*cachep
;
2586 struct work_struct work
;
2589 static void memcg_kmem_cache_create_func(struct work_struct
*w
)
2591 struct memcg_kmem_cache_create_work
*cw
=
2592 container_of(w
, struct memcg_kmem_cache_create_work
, work
);
2593 struct mem_cgroup
*memcg
= cw
->memcg
;
2594 struct kmem_cache
*cachep
= cw
->cachep
;
2596 memcg_create_kmem_cache(memcg
, cachep
);
2598 css_put(&memcg
->css
);
2603 * Enqueue the creation of a per-memcg kmem_cache.
2605 static void __memcg_schedule_kmem_cache_create(struct mem_cgroup
*memcg
,
2606 struct kmem_cache
*cachep
)
2608 struct memcg_kmem_cache_create_work
*cw
;
2610 cw
= kmalloc(sizeof(*cw
), GFP_NOWAIT
);
2614 css_get(&memcg
->css
);
2617 cw
->cachep
= cachep
;
2618 INIT_WORK(&cw
->work
, memcg_kmem_cache_create_func
);
2620 schedule_work(&cw
->work
);
2623 static void memcg_schedule_kmem_cache_create(struct mem_cgroup
*memcg
,
2624 struct kmem_cache
*cachep
)
2627 * We need to stop accounting when we kmalloc, because if the
2628 * corresponding kmalloc cache is not yet created, the first allocation
2629 * in __memcg_schedule_kmem_cache_create will recurse.
2631 * However, it is better to enclose the whole function. Depending on
2632 * the debugging options enabled, INIT_WORK(), for instance, can
2633 * trigger an allocation. This too, will make us recurse. Because at
2634 * this point we can't allow ourselves back into memcg_kmem_get_cache,
2635 * the safest choice is to do it like this, wrapping the whole function.
2637 current
->memcg_kmem_skip_account
= 1;
2638 __memcg_schedule_kmem_cache_create(memcg
, cachep
);
2639 current
->memcg_kmem_skip_account
= 0;
2643 * Return the kmem_cache we're supposed to use for a slab allocation.
2644 * We try to use the current memcg's version of the cache.
2646 * If the cache does not exist yet, if we are the first user of it,
2647 * we either create it immediately, if possible, or create it asynchronously
2649 * In the latter case, we will let the current allocation go through with
2650 * the original cache.
2652 * Can't be called in interrupt context or from kernel threads.
2653 * This function needs to be called with rcu_read_lock() held.
2655 struct kmem_cache
*__memcg_kmem_get_cache(struct kmem_cache
*cachep
)
2657 struct mem_cgroup
*memcg
;
2658 struct kmem_cache
*memcg_cachep
;
2660 VM_BUG_ON(!cachep
->memcg_params
);
2661 VM_BUG_ON(!cachep
->memcg_params
->is_root_cache
);
2663 if (current
->memcg_kmem_skip_account
)
2666 memcg
= get_mem_cgroup_from_mm(current
->mm
);
2667 if (!memcg_kmem_is_active(memcg
))
2670 memcg_cachep
= cache_from_memcg_idx(cachep
, memcg_cache_id(memcg
));
2671 if (likely(memcg_cachep
))
2672 return memcg_cachep
;
2675 * If we are in a safe context (can wait, and not in interrupt
2676 * context), we could be be predictable and return right away.
2677 * This would guarantee that the allocation being performed
2678 * already belongs in the new cache.
2680 * However, there are some clashes that can arrive from locking.
2681 * For instance, because we acquire the slab_mutex while doing
2682 * memcg_create_kmem_cache, this means no further allocation
2683 * could happen with the slab_mutex held. So it's better to
2686 memcg_schedule_kmem_cache_create(memcg
, cachep
);
2688 css_put(&memcg
->css
);
2692 void __memcg_kmem_put_cache(struct kmem_cache
*cachep
)
2694 if (!is_root_cache(cachep
))
2695 css_put(&cachep
->memcg_params
->memcg
->css
);
2699 * We need to verify if the allocation against current->mm->owner's memcg is
2700 * possible for the given order. But the page is not allocated yet, so we'll
2701 * need a further commit step to do the final arrangements.
2703 * It is possible for the task to switch cgroups in this mean time, so at
2704 * commit time, we can't rely on task conversion any longer. We'll then use
2705 * the handle argument to return to the caller which cgroup we should commit
2706 * against. We could also return the memcg directly and avoid the pointer
2707 * passing, but a boolean return value gives better semantics considering
2708 * the compiled-out case as well.
2710 * Returning true means the allocation is possible.
2713 __memcg_kmem_newpage_charge(gfp_t gfp
, struct mem_cgroup
**_memcg
, int order
)
2715 struct mem_cgroup
*memcg
;
2720 memcg
= get_mem_cgroup_from_mm(current
->mm
);
2722 if (!memcg_kmem_is_active(memcg
)) {
2723 css_put(&memcg
->css
);
2727 ret
= memcg_charge_kmem(memcg
, gfp
, 1 << order
);
2731 css_put(&memcg
->css
);
2735 void __memcg_kmem_commit_charge(struct page
*page
, struct mem_cgroup
*memcg
,
2738 VM_BUG_ON(mem_cgroup_is_root(memcg
));
2740 /* The page allocation failed. Revert */
2742 memcg_uncharge_kmem(memcg
, 1 << order
);
2745 page
->mem_cgroup
= memcg
;
2748 void __memcg_kmem_uncharge_pages(struct page
*page
, int order
)
2750 struct mem_cgroup
*memcg
= page
->mem_cgroup
;
2755 VM_BUG_ON_PAGE(mem_cgroup_is_root(memcg
), page
);
2757 memcg_uncharge_kmem(memcg
, 1 << order
);
2758 page
->mem_cgroup
= NULL
;
2760 #endif /* CONFIG_MEMCG_KMEM */
2762 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
2765 * Because tail pages are not marked as "used", set it. We're under
2766 * zone->lru_lock, 'splitting on pmd' and compound_lock.
2767 * charge/uncharge will be never happen and move_account() is done under
2768 * compound_lock(), so we don't have to take care of races.
2770 void mem_cgroup_split_huge_fixup(struct page
*head
)
2774 if (mem_cgroup_disabled())
2777 for (i
= 1; i
< HPAGE_PMD_NR
; i
++)
2778 head
[i
].mem_cgroup
= head
->mem_cgroup
;
2780 __this_cpu_sub(head
->mem_cgroup
->stat
->count
[MEM_CGROUP_STAT_RSS_HUGE
],
2783 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
2786 * mem_cgroup_move_account - move account of the page
2788 * @nr_pages: number of regular pages (>1 for huge pages)
2789 * @from: mem_cgroup which the page is moved from.
2790 * @to: mem_cgroup which the page is moved to. @from != @to.
2792 * The caller must confirm following.
2793 * - page is not on LRU (isolate_page() is useful.)
2794 * - compound_lock is held when nr_pages > 1
2796 * This function doesn't do "charge" to new cgroup and doesn't do "uncharge"
2799 static int mem_cgroup_move_account(struct page
*page
,
2800 unsigned int nr_pages
,
2801 struct mem_cgroup
*from
,
2802 struct mem_cgroup
*to
)
2804 unsigned long flags
;
2807 VM_BUG_ON(from
== to
);
2808 VM_BUG_ON_PAGE(PageLRU(page
), page
);
2810 * The page is isolated from LRU. So, collapse function
2811 * will not handle this page. But page splitting can happen.
2812 * Do this check under compound_page_lock(). The caller should
2816 if (nr_pages
> 1 && !PageTransHuge(page
))
2820 * Prevent mem_cgroup_migrate() from looking at page->mem_cgroup
2821 * of its source page while we change it: page migration takes
2822 * both pages off the LRU, but page cache replacement doesn't.
2824 if (!trylock_page(page
))
2828 if (page
->mem_cgroup
!= from
)
2831 spin_lock_irqsave(&from
->move_lock
, flags
);
2833 if (!PageAnon(page
) && page_mapped(page
)) {
2834 __this_cpu_sub(from
->stat
->count
[MEM_CGROUP_STAT_FILE_MAPPED
],
2836 __this_cpu_add(to
->stat
->count
[MEM_CGROUP_STAT_FILE_MAPPED
],
2840 if (PageWriteback(page
)) {
2841 __this_cpu_sub(from
->stat
->count
[MEM_CGROUP_STAT_WRITEBACK
],
2843 __this_cpu_add(to
->stat
->count
[MEM_CGROUP_STAT_WRITEBACK
],
2848 * It is safe to change page->mem_cgroup here because the page
2849 * is referenced, charged, and isolated - we can't race with
2850 * uncharging, charging, migration, or LRU putback.
2853 /* caller should have done css_get */
2854 page
->mem_cgroup
= to
;
2855 spin_unlock_irqrestore(&from
->move_lock
, flags
);
2859 local_irq_disable();
2860 mem_cgroup_charge_statistics(to
, page
, nr_pages
);
2861 memcg_check_events(to
, page
);
2862 mem_cgroup_charge_statistics(from
, page
, -nr_pages
);
2863 memcg_check_events(from
, page
);
2871 #ifdef CONFIG_MEMCG_SWAP
2872 static void mem_cgroup_swap_statistics(struct mem_cgroup
*memcg
,
2875 int val
= (charge
) ? 1 : -1;
2876 this_cpu_add(memcg
->stat
->count
[MEM_CGROUP_STAT_SWAP
], val
);
2880 * mem_cgroup_move_swap_account - move swap charge and swap_cgroup's record.
2881 * @entry: swap entry to be moved
2882 * @from: mem_cgroup which the entry is moved from
2883 * @to: mem_cgroup which the entry is moved to
2885 * It succeeds only when the swap_cgroup's record for this entry is the same
2886 * as the mem_cgroup's id of @from.
2888 * Returns 0 on success, -EINVAL on failure.
2890 * The caller must have charged to @to, IOW, called page_counter_charge() about
2891 * both res and memsw, and called css_get().
2893 static int mem_cgroup_move_swap_account(swp_entry_t entry
,
2894 struct mem_cgroup
*from
, struct mem_cgroup
*to
)
2896 unsigned short old_id
, new_id
;
2898 old_id
= mem_cgroup_id(from
);
2899 new_id
= mem_cgroup_id(to
);
2901 if (swap_cgroup_cmpxchg(entry
, old_id
, new_id
) == old_id
) {
2902 mem_cgroup_swap_statistics(from
, false);
2903 mem_cgroup_swap_statistics(to
, true);
2909 static inline int mem_cgroup_move_swap_account(swp_entry_t entry
,
2910 struct mem_cgroup
*from
, struct mem_cgroup
*to
)
2916 static DEFINE_MUTEX(memcg_limit_mutex
);
2918 static int mem_cgroup_resize_limit(struct mem_cgroup
*memcg
,
2919 unsigned long limit
)
2921 unsigned long curusage
;
2922 unsigned long oldusage
;
2923 bool enlarge
= false;
2928 * For keeping hierarchical_reclaim simple, how long we should retry
2929 * is depends on callers. We set our retry-count to be function
2930 * of # of children which we should visit in this loop.
2932 retry_count
= MEM_CGROUP_RECLAIM_RETRIES
*
2933 mem_cgroup_count_children(memcg
);
2935 oldusage
= page_counter_read(&memcg
->memory
);
2938 if (signal_pending(current
)) {
2943 mutex_lock(&memcg_limit_mutex
);
2944 if (limit
> memcg
->memsw
.limit
) {
2945 mutex_unlock(&memcg_limit_mutex
);
2949 if (limit
> memcg
->memory
.limit
)
2951 ret
= page_counter_limit(&memcg
->memory
, limit
);
2952 mutex_unlock(&memcg_limit_mutex
);
2957 try_to_free_mem_cgroup_pages(memcg
, 1, GFP_KERNEL
, true);
2959 curusage
= page_counter_read(&memcg
->memory
);
2960 /* Usage is reduced ? */
2961 if (curusage
>= oldusage
)
2964 oldusage
= curusage
;
2965 } while (retry_count
);
2967 if (!ret
&& enlarge
)
2968 memcg_oom_recover(memcg
);
2973 static int mem_cgroup_resize_memsw_limit(struct mem_cgroup
*memcg
,
2974 unsigned long limit
)
2976 unsigned long curusage
;
2977 unsigned long oldusage
;
2978 bool enlarge
= false;
2982 /* see mem_cgroup_resize_res_limit */
2983 retry_count
= MEM_CGROUP_RECLAIM_RETRIES
*
2984 mem_cgroup_count_children(memcg
);
2986 oldusage
= page_counter_read(&memcg
->memsw
);
2989 if (signal_pending(current
)) {
2994 mutex_lock(&memcg_limit_mutex
);
2995 if (limit
< memcg
->memory
.limit
) {
2996 mutex_unlock(&memcg_limit_mutex
);
3000 if (limit
> memcg
->memsw
.limit
)
3002 ret
= page_counter_limit(&memcg
->memsw
, limit
);
3003 mutex_unlock(&memcg_limit_mutex
);
3008 try_to_free_mem_cgroup_pages(memcg
, 1, GFP_KERNEL
, false);
3010 curusage
= page_counter_read(&memcg
->memsw
);
3011 /* Usage is reduced ? */
3012 if (curusage
>= oldusage
)
3015 oldusage
= curusage
;
3016 } while (retry_count
);
3018 if (!ret
&& enlarge
)
3019 memcg_oom_recover(memcg
);
3024 unsigned long mem_cgroup_soft_limit_reclaim(struct zone
*zone
, int order
,
3026 unsigned long *total_scanned
)
3028 unsigned long nr_reclaimed
= 0;
3029 struct mem_cgroup_per_zone
*mz
, *next_mz
= NULL
;
3030 unsigned long reclaimed
;
3032 struct mem_cgroup_tree_per_zone
*mctz
;
3033 unsigned long excess
;
3034 unsigned long nr_scanned
;
3039 mctz
= soft_limit_tree_node_zone(zone_to_nid(zone
), zone_idx(zone
));
3041 * This loop can run a while, specially if mem_cgroup's continuously
3042 * keep exceeding their soft limit and putting the system under
3049 mz
= mem_cgroup_largest_soft_limit_node(mctz
);
3054 reclaimed
= mem_cgroup_soft_reclaim(mz
->memcg
, zone
,
3055 gfp_mask
, &nr_scanned
);
3056 nr_reclaimed
+= reclaimed
;
3057 *total_scanned
+= nr_scanned
;
3058 spin_lock_irq(&mctz
->lock
);
3059 __mem_cgroup_remove_exceeded(mz
, mctz
);
3062 * If we failed to reclaim anything from this memory cgroup
3063 * it is time to move on to the next cgroup
3067 next_mz
= __mem_cgroup_largest_soft_limit_node(mctz
);
3069 excess
= soft_limit_excess(mz
->memcg
);
3071 * One school of thought says that we should not add
3072 * back the node to the tree if reclaim returns 0.
3073 * But our reclaim could return 0, simply because due
3074 * to priority we are exposing a smaller subset of
3075 * memory to reclaim from. Consider this as a longer
3078 /* If excess == 0, no tree ops */
3079 __mem_cgroup_insert_exceeded(mz
, mctz
, excess
);
3080 spin_unlock_irq(&mctz
->lock
);
3081 css_put(&mz
->memcg
->css
);
3084 * Could not reclaim anything and there are no more
3085 * mem cgroups to try or we seem to be looping without
3086 * reclaiming anything.
3088 if (!nr_reclaimed
&&
3090 loop
> MEM_CGROUP_MAX_SOFT_LIMIT_RECLAIM_LOOPS
))
3092 } while (!nr_reclaimed
);
3094 css_put(&next_mz
->memcg
->css
);
3095 return nr_reclaimed
;
3099 * Test whether @memcg has children, dead or alive. Note that this
3100 * function doesn't care whether @memcg has use_hierarchy enabled and
3101 * returns %true if there are child csses according to the cgroup
3102 * hierarchy. Testing use_hierarchy is the caller's responsiblity.
3104 static inline bool memcg_has_children(struct mem_cgroup
*memcg
)
3109 * The lock does not prevent addition or deletion of children, but
3110 * it prevents a new child from being initialized based on this
3111 * parent in css_online(), so it's enough to decide whether
3112 * hierarchically inherited attributes can still be changed or not.
3114 lockdep_assert_held(&memcg_create_mutex
);
3117 ret
= css_next_child(NULL
, &memcg
->css
);
3123 * Reclaims as many pages from the given memcg as possible and moves
3124 * the rest to the parent.
3126 * Caller is responsible for holding css reference for memcg.
3128 static int mem_cgroup_force_empty(struct mem_cgroup
*memcg
)
3130 int nr_retries
= MEM_CGROUP_RECLAIM_RETRIES
;
3132 /* we call try-to-free pages for make this cgroup empty */
3133 lru_add_drain_all();
3134 /* try to free all pages in this cgroup */
3135 while (nr_retries
&& page_counter_read(&memcg
->memory
)) {
3138 if (signal_pending(current
))
3141 progress
= try_to_free_mem_cgroup_pages(memcg
, 1,
3145 /* maybe some writeback is necessary */
3146 congestion_wait(BLK_RW_ASYNC
, HZ
/10);
3154 static ssize_t
mem_cgroup_force_empty_write(struct kernfs_open_file
*of
,
3155 char *buf
, size_t nbytes
,
3158 struct mem_cgroup
*memcg
= mem_cgroup_from_css(of_css(of
));
3160 if (mem_cgroup_is_root(memcg
))
3162 return mem_cgroup_force_empty(memcg
) ?: nbytes
;
3165 static u64
mem_cgroup_hierarchy_read(struct cgroup_subsys_state
*css
,
3168 return mem_cgroup_from_css(css
)->use_hierarchy
;
3171 static int mem_cgroup_hierarchy_write(struct cgroup_subsys_state
*css
,
3172 struct cftype
*cft
, u64 val
)
3175 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
3176 struct mem_cgroup
*parent_memcg
= mem_cgroup_from_css(memcg
->css
.parent
);
3178 mutex_lock(&memcg_create_mutex
);
3180 if (memcg
->use_hierarchy
== val
)
3184 * If parent's use_hierarchy is set, we can't make any modifications
3185 * in the child subtrees. If it is unset, then the change can
3186 * occur, provided the current cgroup has no children.
3188 * For the root cgroup, parent_mem is NULL, we allow value to be
3189 * set if there are no children.
3191 if ((!parent_memcg
|| !parent_memcg
->use_hierarchy
) &&
3192 (val
== 1 || val
== 0)) {
3193 if (!memcg_has_children(memcg
))
3194 memcg
->use_hierarchy
= val
;
3201 mutex_unlock(&memcg_create_mutex
);
3206 static unsigned long tree_stat(struct mem_cgroup
*memcg
,
3207 enum mem_cgroup_stat_index idx
)
3209 struct mem_cgroup
*iter
;
3212 /* Per-cpu values can be negative, use a signed accumulator */
3213 for_each_mem_cgroup_tree(iter
, memcg
)
3214 val
+= mem_cgroup_read_stat(iter
, idx
);
3216 if (val
< 0) /* race ? */
3221 static inline u64
mem_cgroup_usage(struct mem_cgroup
*memcg
, bool swap
)
3225 if (mem_cgroup_is_root(memcg
)) {
3226 val
= tree_stat(memcg
, MEM_CGROUP_STAT_CACHE
);
3227 val
+= tree_stat(memcg
, MEM_CGROUP_STAT_RSS
);
3229 val
+= tree_stat(memcg
, MEM_CGROUP_STAT_SWAP
);
3232 val
= page_counter_read(&memcg
->memory
);
3234 val
= page_counter_read(&memcg
->memsw
);
3236 return val
<< PAGE_SHIFT
;
3247 static u64
mem_cgroup_read_u64(struct cgroup_subsys_state
*css
,
3250 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
3251 struct page_counter
*counter
;
3253 switch (MEMFILE_TYPE(cft
->private)) {
3255 counter
= &memcg
->memory
;
3258 counter
= &memcg
->memsw
;
3261 counter
= &memcg
->kmem
;
3267 switch (MEMFILE_ATTR(cft
->private)) {
3269 if (counter
== &memcg
->memory
)
3270 return mem_cgroup_usage(memcg
, false);
3271 if (counter
== &memcg
->memsw
)
3272 return mem_cgroup_usage(memcg
, true);
3273 return (u64
)page_counter_read(counter
) * PAGE_SIZE
;
3275 return (u64
)counter
->limit
* PAGE_SIZE
;
3277 return (u64
)counter
->watermark
* PAGE_SIZE
;
3279 return counter
->failcnt
;
3280 case RES_SOFT_LIMIT
:
3281 return (u64
)memcg
->soft_limit
* PAGE_SIZE
;
3287 #ifdef CONFIG_MEMCG_KMEM
3288 static int memcg_activate_kmem(struct mem_cgroup
*memcg
,
3289 unsigned long nr_pages
)
3294 if (memcg_kmem_is_active(memcg
))
3298 * For simplicity, we won't allow this to be disabled. It also can't
3299 * be changed if the cgroup has children already, or if tasks had
3302 * If tasks join before we set the limit, a person looking at
3303 * kmem.usage_in_bytes will have no way to determine when it took
3304 * place, which makes the value quite meaningless.
3306 * After it first became limited, changes in the value of the limit are
3307 * of course permitted.
3309 mutex_lock(&memcg_create_mutex
);
3310 if (cgroup_has_tasks(memcg
->css
.cgroup
) ||
3311 (memcg
->use_hierarchy
&& memcg_has_children(memcg
)))
3313 mutex_unlock(&memcg_create_mutex
);
3317 memcg_id
= memcg_alloc_cache_id();
3324 * We couldn't have accounted to this cgroup, because it hasn't got
3325 * activated yet, so this should succeed.
3327 err
= page_counter_limit(&memcg
->kmem
, nr_pages
);
3330 static_key_slow_inc(&memcg_kmem_enabled_key
);
3332 * A memory cgroup is considered kmem-active as soon as it gets
3333 * kmemcg_id. Setting the id after enabling static branching will
3334 * guarantee no one starts accounting before all call sites are
3337 memcg
->kmemcg_id
= memcg_id
;
3342 static int memcg_update_kmem_limit(struct mem_cgroup
*memcg
,
3343 unsigned long limit
)
3347 mutex_lock(&memcg_limit_mutex
);
3348 if (!memcg_kmem_is_active(memcg
))
3349 ret
= memcg_activate_kmem(memcg
, limit
);
3351 ret
= page_counter_limit(&memcg
->kmem
, limit
);
3352 mutex_unlock(&memcg_limit_mutex
);
3356 static int memcg_propagate_kmem(struct mem_cgroup
*memcg
)
3359 struct mem_cgroup
*parent
= parent_mem_cgroup(memcg
);
3364 mutex_lock(&memcg_limit_mutex
);
3366 * If the parent cgroup is not kmem-active now, it cannot be activated
3367 * after this point, because it has at least one child already.
3369 if (memcg_kmem_is_active(parent
))
3370 ret
= memcg_activate_kmem(memcg
, PAGE_COUNTER_MAX
);
3371 mutex_unlock(&memcg_limit_mutex
);
3375 static int memcg_update_kmem_limit(struct mem_cgroup
*memcg
,
3376 unsigned long limit
)
3380 #endif /* CONFIG_MEMCG_KMEM */
3383 * The user of this function is...
3386 static ssize_t
mem_cgroup_write(struct kernfs_open_file
*of
,
3387 char *buf
, size_t nbytes
, loff_t off
)
3389 struct mem_cgroup
*memcg
= mem_cgroup_from_css(of_css(of
));
3390 unsigned long nr_pages
;
3393 buf
= strstrip(buf
);
3394 ret
= page_counter_memparse(buf
, "-1", &nr_pages
);
3398 switch (MEMFILE_ATTR(of_cft(of
)->private)) {
3400 if (mem_cgroup_is_root(memcg
)) { /* Can't set limit on root */
3404 switch (MEMFILE_TYPE(of_cft(of
)->private)) {
3406 ret
= mem_cgroup_resize_limit(memcg
, nr_pages
);
3409 ret
= mem_cgroup_resize_memsw_limit(memcg
, nr_pages
);
3412 ret
= memcg_update_kmem_limit(memcg
, nr_pages
);
3416 case RES_SOFT_LIMIT
:
3417 memcg
->soft_limit
= nr_pages
;
3421 return ret
?: nbytes
;
3424 static ssize_t
mem_cgroup_reset(struct kernfs_open_file
*of
, char *buf
,
3425 size_t nbytes
, loff_t off
)
3427 struct mem_cgroup
*memcg
= mem_cgroup_from_css(of_css(of
));
3428 struct page_counter
*counter
;
3430 switch (MEMFILE_TYPE(of_cft(of
)->private)) {
3432 counter
= &memcg
->memory
;
3435 counter
= &memcg
->memsw
;
3438 counter
= &memcg
->kmem
;
3444 switch (MEMFILE_ATTR(of_cft(of
)->private)) {
3446 page_counter_reset_watermark(counter
);
3449 counter
->failcnt
= 0;
3458 static u64
mem_cgroup_move_charge_read(struct cgroup_subsys_state
*css
,
3461 return mem_cgroup_from_css(css
)->move_charge_at_immigrate
;
3465 static int mem_cgroup_move_charge_write(struct cgroup_subsys_state
*css
,
3466 struct cftype
*cft
, u64 val
)
3468 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
3470 if (val
& ~MOVE_MASK
)
3474 * No kind of locking is needed in here, because ->can_attach() will
3475 * check this value once in the beginning of the process, and then carry
3476 * on with stale data. This means that changes to this value will only
3477 * affect task migrations starting after the change.
3479 memcg
->move_charge_at_immigrate
= val
;
3483 static int mem_cgroup_move_charge_write(struct cgroup_subsys_state
*css
,
3484 struct cftype
*cft
, u64 val
)
3491 static int memcg_numa_stat_show(struct seq_file
*m
, void *v
)
3495 unsigned int lru_mask
;
3498 static const struct numa_stat stats
[] = {
3499 { "total", LRU_ALL
},
3500 { "file", LRU_ALL_FILE
},
3501 { "anon", LRU_ALL_ANON
},
3502 { "unevictable", BIT(LRU_UNEVICTABLE
) },
3504 const struct numa_stat
*stat
;
3507 struct mem_cgroup
*memcg
= mem_cgroup_from_css(seq_css(m
));
3509 for (stat
= stats
; stat
< stats
+ ARRAY_SIZE(stats
); stat
++) {
3510 nr
= mem_cgroup_nr_lru_pages(memcg
, stat
->lru_mask
);
3511 seq_printf(m
, "%s=%lu", stat
->name
, nr
);
3512 for_each_node_state(nid
, N_MEMORY
) {
3513 nr
= mem_cgroup_node_nr_lru_pages(memcg
, nid
,
3515 seq_printf(m
, " N%d=%lu", nid
, nr
);
3520 for (stat
= stats
; stat
< stats
+ ARRAY_SIZE(stats
); stat
++) {
3521 struct mem_cgroup
*iter
;
3524 for_each_mem_cgroup_tree(iter
, memcg
)
3525 nr
+= mem_cgroup_nr_lru_pages(iter
, stat
->lru_mask
);
3526 seq_printf(m
, "hierarchical_%s=%lu", stat
->name
, nr
);
3527 for_each_node_state(nid
, N_MEMORY
) {
3529 for_each_mem_cgroup_tree(iter
, memcg
)
3530 nr
+= mem_cgroup_node_nr_lru_pages(
3531 iter
, nid
, stat
->lru_mask
);
3532 seq_printf(m
, " N%d=%lu", nid
, nr
);
3539 #endif /* CONFIG_NUMA */
3541 static int memcg_stat_show(struct seq_file
*m
, void *v
)
3543 struct mem_cgroup
*memcg
= mem_cgroup_from_css(seq_css(m
));
3544 unsigned long memory
, memsw
;
3545 struct mem_cgroup
*mi
;
3548 BUILD_BUG_ON(ARRAY_SIZE(mem_cgroup_stat_names
) !=
3549 MEM_CGROUP_STAT_NSTATS
);
3550 BUILD_BUG_ON(ARRAY_SIZE(mem_cgroup_events_names
) !=
3551 MEM_CGROUP_EVENTS_NSTATS
);
3552 BUILD_BUG_ON(ARRAY_SIZE(mem_cgroup_lru_names
) != NR_LRU_LISTS
);
3554 for (i
= 0; i
< MEM_CGROUP_STAT_NSTATS
; i
++) {
3555 if (i
== MEM_CGROUP_STAT_SWAP
&& !do_swap_account
)
3557 seq_printf(m
, "%s %ld\n", mem_cgroup_stat_names
[i
],
3558 mem_cgroup_read_stat(memcg
, i
) * PAGE_SIZE
);
3561 for (i
= 0; i
< MEM_CGROUP_EVENTS_NSTATS
; i
++)
3562 seq_printf(m
, "%s %lu\n", mem_cgroup_events_names
[i
],
3563 mem_cgroup_read_events(memcg
, i
));
3565 for (i
= 0; i
< NR_LRU_LISTS
; i
++)
3566 seq_printf(m
, "%s %lu\n", mem_cgroup_lru_names
[i
],
3567 mem_cgroup_nr_lru_pages(memcg
, BIT(i
)) * PAGE_SIZE
);
3569 /* Hierarchical information */
3570 memory
= memsw
= PAGE_COUNTER_MAX
;
3571 for (mi
= memcg
; mi
; mi
= parent_mem_cgroup(mi
)) {
3572 memory
= min(memory
, mi
->memory
.limit
);
3573 memsw
= min(memsw
, mi
->memsw
.limit
);
3575 seq_printf(m
, "hierarchical_memory_limit %llu\n",
3576 (u64
)memory
* PAGE_SIZE
);
3577 if (do_swap_account
)
3578 seq_printf(m
, "hierarchical_memsw_limit %llu\n",
3579 (u64
)memsw
* PAGE_SIZE
);
3581 for (i
= 0; i
< MEM_CGROUP_STAT_NSTATS
; i
++) {
3584 if (i
== MEM_CGROUP_STAT_SWAP
&& !do_swap_account
)
3586 for_each_mem_cgroup_tree(mi
, memcg
)
3587 val
+= mem_cgroup_read_stat(mi
, i
) * PAGE_SIZE
;
3588 seq_printf(m
, "total_%s %lld\n", mem_cgroup_stat_names
[i
], val
);
3591 for (i
= 0; i
< MEM_CGROUP_EVENTS_NSTATS
; i
++) {
3592 unsigned long long val
= 0;
3594 for_each_mem_cgroup_tree(mi
, memcg
)
3595 val
+= mem_cgroup_read_events(mi
, i
);
3596 seq_printf(m
, "total_%s %llu\n",
3597 mem_cgroup_events_names
[i
], val
);
3600 for (i
= 0; i
< NR_LRU_LISTS
; i
++) {
3601 unsigned long long val
= 0;
3603 for_each_mem_cgroup_tree(mi
, memcg
)
3604 val
+= mem_cgroup_nr_lru_pages(mi
, BIT(i
)) * PAGE_SIZE
;
3605 seq_printf(m
, "total_%s %llu\n", mem_cgroup_lru_names
[i
], val
);
3608 #ifdef CONFIG_DEBUG_VM
3611 struct mem_cgroup_per_zone
*mz
;
3612 struct zone_reclaim_stat
*rstat
;
3613 unsigned long recent_rotated
[2] = {0, 0};
3614 unsigned long recent_scanned
[2] = {0, 0};
3616 for_each_online_node(nid
)
3617 for (zid
= 0; zid
< MAX_NR_ZONES
; zid
++) {
3618 mz
= &memcg
->nodeinfo
[nid
]->zoneinfo
[zid
];
3619 rstat
= &mz
->lruvec
.reclaim_stat
;
3621 recent_rotated
[0] += rstat
->recent_rotated
[0];
3622 recent_rotated
[1] += rstat
->recent_rotated
[1];
3623 recent_scanned
[0] += rstat
->recent_scanned
[0];
3624 recent_scanned
[1] += rstat
->recent_scanned
[1];
3626 seq_printf(m
, "recent_rotated_anon %lu\n", recent_rotated
[0]);
3627 seq_printf(m
, "recent_rotated_file %lu\n", recent_rotated
[1]);
3628 seq_printf(m
, "recent_scanned_anon %lu\n", recent_scanned
[0]);
3629 seq_printf(m
, "recent_scanned_file %lu\n", recent_scanned
[1]);
3636 static u64
mem_cgroup_swappiness_read(struct cgroup_subsys_state
*css
,
3639 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
3641 return mem_cgroup_swappiness(memcg
);
3644 static int mem_cgroup_swappiness_write(struct cgroup_subsys_state
*css
,
3645 struct cftype
*cft
, u64 val
)
3647 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
3653 memcg
->swappiness
= val
;
3655 vm_swappiness
= val
;
3660 static void __mem_cgroup_threshold(struct mem_cgroup
*memcg
, bool swap
)
3662 struct mem_cgroup_threshold_ary
*t
;
3663 unsigned long usage
;
3668 t
= rcu_dereference(memcg
->thresholds
.primary
);
3670 t
= rcu_dereference(memcg
->memsw_thresholds
.primary
);
3675 usage
= mem_cgroup_usage(memcg
, swap
);
3678 * current_threshold points to threshold just below or equal to usage.
3679 * If it's not true, a threshold was crossed after last
3680 * call of __mem_cgroup_threshold().
3682 i
= t
->current_threshold
;
3685 * Iterate backward over array of thresholds starting from
3686 * current_threshold and check if a threshold is crossed.
3687 * If none of thresholds below usage is crossed, we read
3688 * only one element of the array here.
3690 for (; i
>= 0 && unlikely(t
->entries
[i
].threshold
> usage
); i
--)
3691 eventfd_signal(t
->entries
[i
].eventfd
, 1);
3693 /* i = current_threshold + 1 */
3697 * Iterate forward over array of thresholds starting from
3698 * current_threshold+1 and check if a threshold is crossed.
3699 * If none of thresholds above usage is crossed, we read
3700 * only one element of the array here.
3702 for (; i
< t
->size
&& unlikely(t
->entries
[i
].threshold
<= usage
); i
++)
3703 eventfd_signal(t
->entries
[i
].eventfd
, 1);
3705 /* Update current_threshold */
3706 t
->current_threshold
= i
- 1;
3711 static void mem_cgroup_threshold(struct mem_cgroup
*memcg
)
3714 __mem_cgroup_threshold(memcg
, false);
3715 if (do_swap_account
)
3716 __mem_cgroup_threshold(memcg
, true);
3718 memcg
= parent_mem_cgroup(memcg
);
3722 static int compare_thresholds(const void *a
, const void *b
)
3724 const struct mem_cgroup_threshold
*_a
= a
;
3725 const struct mem_cgroup_threshold
*_b
= b
;
3727 if (_a
->threshold
> _b
->threshold
)
3730 if (_a
->threshold
< _b
->threshold
)
3736 static int mem_cgroup_oom_notify_cb(struct mem_cgroup
*memcg
)
3738 struct mem_cgroup_eventfd_list
*ev
;
3740 spin_lock(&memcg_oom_lock
);
3742 list_for_each_entry(ev
, &memcg
->oom_notify
, list
)
3743 eventfd_signal(ev
->eventfd
, 1);
3745 spin_unlock(&memcg_oom_lock
);
3749 static void mem_cgroup_oom_notify(struct mem_cgroup
*memcg
)
3751 struct mem_cgroup
*iter
;
3753 for_each_mem_cgroup_tree(iter
, memcg
)
3754 mem_cgroup_oom_notify_cb(iter
);
3757 static int __mem_cgroup_usage_register_event(struct mem_cgroup
*memcg
,
3758 struct eventfd_ctx
*eventfd
, const char *args
, enum res_type type
)
3760 struct mem_cgroup_thresholds
*thresholds
;
3761 struct mem_cgroup_threshold_ary
*new;
3762 unsigned long threshold
;
3763 unsigned long usage
;
3766 ret
= page_counter_memparse(args
, "-1", &threshold
);
3770 mutex_lock(&memcg
->thresholds_lock
);
3773 thresholds
= &memcg
->thresholds
;
3774 usage
= mem_cgroup_usage(memcg
, false);
3775 } else if (type
== _MEMSWAP
) {
3776 thresholds
= &memcg
->memsw_thresholds
;
3777 usage
= mem_cgroup_usage(memcg
, true);
3781 /* Check if a threshold crossed before adding a new one */
3782 if (thresholds
->primary
)
3783 __mem_cgroup_threshold(memcg
, type
== _MEMSWAP
);
3785 size
= thresholds
->primary
? thresholds
->primary
->size
+ 1 : 1;
3787 /* Allocate memory for new array of thresholds */
3788 new = kmalloc(sizeof(*new) + size
* sizeof(struct mem_cgroup_threshold
),
3796 /* Copy thresholds (if any) to new array */
3797 if (thresholds
->primary
) {
3798 memcpy(new->entries
, thresholds
->primary
->entries
, (size
- 1) *
3799 sizeof(struct mem_cgroup_threshold
));
3802 /* Add new threshold */
3803 new->entries
[size
- 1].eventfd
= eventfd
;
3804 new->entries
[size
- 1].threshold
= threshold
;
3806 /* Sort thresholds. Registering of new threshold isn't time-critical */
3807 sort(new->entries
, size
, sizeof(struct mem_cgroup_threshold
),
3808 compare_thresholds
, NULL
);
3810 /* Find current threshold */
3811 new->current_threshold
= -1;
3812 for (i
= 0; i
< size
; i
++) {
3813 if (new->entries
[i
].threshold
<= usage
) {
3815 * new->current_threshold will not be used until
3816 * rcu_assign_pointer(), so it's safe to increment
3819 ++new->current_threshold
;
3824 /* Free old spare buffer and save old primary buffer as spare */
3825 kfree(thresholds
->spare
);
3826 thresholds
->spare
= thresholds
->primary
;
3828 rcu_assign_pointer(thresholds
->primary
, new);
3830 /* To be sure that nobody uses thresholds */
3834 mutex_unlock(&memcg
->thresholds_lock
);
3839 static int mem_cgroup_usage_register_event(struct mem_cgroup
*memcg
,
3840 struct eventfd_ctx
*eventfd
, const char *args
)
3842 return __mem_cgroup_usage_register_event(memcg
, eventfd
, args
, _MEM
);
3845 static int memsw_cgroup_usage_register_event(struct mem_cgroup
*memcg
,
3846 struct eventfd_ctx
*eventfd
, const char *args
)
3848 return __mem_cgroup_usage_register_event(memcg
, eventfd
, args
, _MEMSWAP
);
3851 static void __mem_cgroup_usage_unregister_event(struct mem_cgroup
*memcg
,
3852 struct eventfd_ctx
*eventfd
, enum res_type type
)
3854 struct mem_cgroup_thresholds
*thresholds
;
3855 struct mem_cgroup_threshold_ary
*new;
3856 unsigned long usage
;
3859 mutex_lock(&memcg
->thresholds_lock
);
3862 thresholds
= &memcg
->thresholds
;
3863 usage
= mem_cgroup_usage(memcg
, false);
3864 } else if (type
== _MEMSWAP
) {
3865 thresholds
= &memcg
->memsw_thresholds
;
3866 usage
= mem_cgroup_usage(memcg
, true);
3870 if (!thresholds
->primary
)
3873 /* Check if a threshold crossed before removing */
3874 __mem_cgroup_threshold(memcg
, type
== _MEMSWAP
);
3876 /* Calculate new number of threshold */
3878 for (i
= 0; i
< thresholds
->primary
->size
; i
++) {
3879 if (thresholds
->primary
->entries
[i
].eventfd
!= eventfd
)
3883 new = thresholds
->spare
;
3885 /* Set thresholds array to NULL if we don't have thresholds */
3894 /* Copy thresholds and find current threshold */
3895 new->current_threshold
= -1;
3896 for (i
= 0, j
= 0; i
< thresholds
->primary
->size
; i
++) {
3897 if (thresholds
->primary
->entries
[i
].eventfd
== eventfd
)
3900 new->entries
[j
] = thresholds
->primary
->entries
[i
];
3901 if (new->entries
[j
].threshold
<= usage
) {
3903 * new->current_threshold will not be used
3904 * until rcu_assign_pointer(), so it's safe to increment
3907 ++new->current_threshold
;
3913 /* Swap primary and spare array */
3914 thresholds
->spare
= thresholds
->primary
;
3915 /* If all events are unregistered, free the spare array */
3917 kfree(thresholds
->spare
);
3918 thresholds
->spare
= NULL
;
3921 rcu_assign_pointer(thresholds
->primary
, new);
3923 /* To be sure that nobody uses thresholds */
3926 mutex_unlock(&memcg
->thresholds_lock
);
3929 static void mem_cgroup_usage_unregister_event(struct mem_cgroup
*memcg
,
3930 struct eventfd_ctx
*eventfd
)
3932 return __mem_cgroup_usage_unregister_event(memcg
, eventfd
, _MEM
);
3935 static void memsw_cgroup_usage_unregister_event(struct mem_cgroup
*memcg
,
3936 struct eventfd_ctx
*eventfd
)
3938 return __mem_cgroup_usage_unregister_event(memcg
, eventfd
, _MEMSWAP
);
3941 static int mem_cgroup_oom_register_event(struct mem_cgroup
*memcg
,
3942 struct eventfd_ctx
*eventfd
, const char *args
)
3944 struct mem_cgroup_eventfd_list
*event
;
3946 event
= kmalloc(sizeof(*event
), GFP_KERNEL
);
3950 spin_lock(&memcg_oom_lock
);
3952 event
->eventfd
= eventfd
;
3953 list_add(&event
->list
, &memcg
->oom_notify
);
3955 /* already in OOM ? */
3956 if (atomic_read(&memcg
->under_oom
))
3957 eventfd_signal(eventfd
, 1);
3958 spin_unlock(&memcg_oom_lock
);
3963 static void mem_cgroup_oom_unregister_event(struct mem_cgroup
*memcg
,
3964 struct eventfd_ctx
*eventfd
)
3966 struct mem_cgroup_eventfd_list
*ev
, *tmp
;
3968 spin_lock(&memcg_oom_lock
);
3970 list_for_each_entry_safe(ev
, tmp
, &memcg
->oom_notify
, list
) {
3971 if (ev
->eventfd
== eventfd
) {
3972 list_del(&ev
->list
);
3977 spin_unlock(&memcg_oom_lock
);
3980 static int mem_cgroup_oom_control_read(struct seq_file
*sf
, void *v
)
3982 struct mem_cgroup
*memcg
= mem_cgroup_from_css(seq_css(sf
));
3984 seq_printf(sf
, "oom_kill_disable %d\n", memcg
->oom_kill_disable
);
3985 seq_printf(sf
, "under_oom %d\n", (bool)atomic_read(&memcg
->under_oom
));
3989 static int mem_cgroup_oom_control_write(struct cgroup_subsys_state
*css
,
3990 struct cftype
*cft
, u64 val
)
3992 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
3994 /* cannot set to root cgroup and only 0 and 1 are allowed */
3995 if (!css
->parent
|| !((val
== 0) || (val
== 1)))
3998 memcg
->oom_kill_disable
= val
;
4000 memcg_oom_recover(memcg
);
4005 #ifdef CONFIG_MEMCG_KMEM
4006 static int memcg_init_kmem(struct mem_cgroup
*memcg
, struct cgroup_subsys
*ss
)
4010 ret
= memcg_propagate_kmem(memcg
);
4014 return mem_cgroup_sockets_init(memcg
, ss
);
4017 static void memcg_destroy_kmem(struct mem_cgroup
*memcg
)
4019 memcg_destroy_kmem_caches(memcg
);
4020 mem_cgroup_sockets_destroy(memcg
);
4023 static int memcg_init_kmem(struct mem_cgroup
*memcg
, struct cgroup_subsys
*ss
)
4028 static void memcg_destroy_kmem(struct mem_cgroup
*memcg
)
4034 * DO NOT USE IN NEW FILES.
4036 * "cgroup.event_control" implementation.
4038 * This is way over-engineered. It tries to support fully configurable
4039 * events for each user. Such level of flexibility is completely
4040 * unnecessary especially in the light of the planned unified hierarchy.
4042 * Please deprecate this and replace with something simpler if at all
4047 * Unregister event and free resources.
4049 * Gets called from workqueue.
4051 static void memcg_event_remove(struct work_struct
*work
)
4053 struct mem_cgroup_event
*event
=
4054 container_of(work
, struct mem_cgroup_event
, remove
);
4055 struct mem_cgroup
*memcg
= event
->memcg
;
4057 remove_wait_queue(event
->wqh
, &event
->wait
);
4059 event
->unregister_event(memcg
, event
->eventfd
);
4061 /* Notify userspace the event is going away. */
4062 eventfd_signal(event
->eventfd
, 1);
4064 eventfd_ctx_put(event
->eventfd
);
4066 css_put(&memcg
->css
);
4070 * Gets called on POLLHUP on eventfd when user closes it.
4072 * Called with wqh->lock held and interrupts disabled.
4074 static int memcg_event_wake(wait_queue_t
*wait
, unsigned mode
,
4075 int sync
, void *key
)
4077 struct mem_cgroup_event
*event
=
4078 container_of(wait
, struct mem_cgroup_event
, wait
);
4079 struct mem_cgroup
*memcg
= event
->memcg
;
4080 unsigned long flags
= (unsigned long)key
;
4082 if (flags
& POLLHUP
) {
4084 * If the event has been detached at cgroup removal, we
4085 * can simply return knowing the other side will cleanup
4088 * We can't race against event freeing since the other
4089 * side will require wqh->lock via remove_wait_queue(),
4092 spin_lock(&memcg
->event_list_lock
);
4093 if (!list_empty(&event
->list
)) {
4094 list_del_init(&event
->list
);
4096 * We are in atomic context, but cgroup_event_remove()
4097 * may sleep, so we have to call it in workqueue.
4099 schedule_work(&event
->remove
);
4101 spin_unlock(&memcg
->event_list_lock
);
4107 static void memcg_event_ptable_queue_proc(struct file
*file
,
4108 wait_queue_head_t
*wqh
, poll_table
*pt
)
4110 struct mem_cgroup_event
*event
=
4111 container_of(pt
, struct mem_cgroup_event
, pt
);
4114 add_wait_queue(wqh
, &event
->wait
);
4118 * DO NOT USE IN NEW FILES.
4120 * Parse input and register new cgroup event handler.
4122 * Input must be in format '<event_fd> <control_fd> <args>'.
4123 * Interpretation of args is defined by control file implementation.
4125 static ssize_t
memcg_write_event_control(struct kernfs_open_file
*of
,
4126 char *buf
, size_t nbytes
, loff_t off
)
4128 struct cgroup_subsys_state
*css
= of_css(of
);
4129 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
4130 struct mem_cgroup_event
*event
;
4131 struct cgroup_subsys_state
*cfile_css
;
4132 unsigned int efd
, cfd
;
4139 buf
= strstrip(buf
);
4141 efd
= simple_strtoul(buf
, &endp
, 10);
4146 cfd
= simple_strtoul(buf
, &endp
, 10);
4147 if ((*endp
!= ' ') && (*endp
!= '\0'))
4151 event
= kzalloc(sizeof(*event
), GFP_KERNEL
);
4155 event
->memcg
= memcg
;
4156 INIT_LIST_HEAD(&event
->list
);
4157 init_poll_funcptr(&event
->pt
, memcg_event_ptable_queue_proc
);
4158 init_waitqueue_func_entry(&event
->wait
, memcg_event_wake
);
4159 INIT_WORK(&event
->remove
, memcg_event_remove
);
4167 event
->eventfd
= eventfd_ctx_fileget(efile
.file
);
4168 if (IS_ERR(event
->eventfd
)) {
4169 ret
= PTR_ERR(event
->eventfd
);
4176 goto out_put_eventfd
;
4179 /* the process need read permission on control file */
4180 /* AV: shouldn't we check that it's been opened for read instead? */
4181 ret
= inode_permission(file_inode(cfile
.file
), MAY_READ
);
4186 * Determine the event callbacks and set them in @event. This used
4187 * to be done via struct cftype but cgroup core no longer knows
4188 * about these events. The following is crude but the whole thing
4189 * is for compatibility anyway.
4191 * DO NOT ADD NEW FILES.
4193 name
= cfile
.file
->f_path
.dentry
->d_name
.name
;
4195 if (!strcmp(name
, "memory.usage_in_bytes")) {
4196 event
->register_event
= mem_cgroup_usage_register_event
;
4197 event
->unregister_event
= mem_cgroup_usage_unregister_event
;
4198 } else if (!strcmp(name
, "memory.oom_control")) {
4199 event
->register_event
= mem_cgroup_oom_register_event
;
4200 event
->unregister_event
= mem_cgroup_oom_unregister_event
;
4201 } else if (!strcmp(name
, "memory.pressure_level")) {
4202 event
->register_event
= vmpressure_register_event
;
4203 event
->unregister_event
= vmpressure_unregister_event
;
4204 } else if (!strcmp(name
, "memory.memsw.usage_in_bytes")) {
4205 event
->register_event
= memsw_cgroup_usage_register_event
;
4206 event
->unregister_event
= memsw_cgroup_usage_unregister_event
;
4213 * Verify @cfile should belong to @css. Also, remaining events are
4214 * automatically removed on cgroup destruction but the removal is
4215 * asynchronous, so take an extra ref on @css.
4217 cfile_css
= css_tryget_online_from_dir(cfile
.file
->f_path
.dentry
->d_parent
,
4218 &memory_cgrp_subsys
);
4220 if (IS_ERR(cfile_css
))
4222 if (cfile_css
!= css
) {
4227 ret
= event
->register_event(memcg
, event
->eventfd
, buf
);
4231 efile
.file
->f_op
->poll(efile
.file
, &event
->pt
);
4233 spin_lock(&memcg
->event_list_lock
);
4234 list_add(&event
->list
, &memcg
->event_list
);
4235 spin_unlock(&memcg
->event_list_lock
);
4247 eventfd_ctx_put(event
->eventfd
);
4256 static struct cftype mem_cgroup_legacy_files
[] = {
4258 .name
= "usage_in_bytes",
4259 .private = MEMFILE_PRIVATE(_MEM
, RES_USAGE
),
4260 .read_u64
= mem_cgroup_read_u64
,
4263 .name
= "max_usage_in_bytes",
4264 .private = MEMFILE_PRIVATE(_MEM
, RES_MAX_USAGE
),
4265 .write
= mem_cgroup_reset
,
4266 .read_u64
= mem_cgroup_read_u64
,
4269 .name
= "limit_in_bytes",
4270 .private = MEMFILE_PRIVATE(_MEM
, RES_LIMIT
),
4271 .write
= mem_cgroup_write
,
4272 .read_u64
= mem_cgroup_read_u64
,
4275 .name
= "soft_limit_in_bytes",
4276 .private = MEMFILE_PRIVATE(_MEM
, RES_SOFT_LIMIT
),
4277 .write
= mem_cgroup_write
,
4278 .read_u64
= mem_cgroup_read_u64
,
4282 .private = MEMFILE_PRIVATE(_MEM
, RES_FAILCNT
),
4283 .write
= mem_cgroup_reset
,
4284 .read_u64
= mem_cgroup_read_u64
,
4288 .seq_show
= memcg_stat_show
,
4291 .name
= "force_empty",
4292 .write
= mem_cgroup_force_empty_write
,
4295 .name
= "use_hierarchy",
4296 .write_u64
= mem_cgroup_hierarchy_write
,
4297 .read_u64
= mem_cgroup_hierarchy_read
,
4300 .name
= "cgroup.event_control", /* XXX: for compat */
4301 .write
= memcg_write_event_control
,
4302 .flags
= CFTYPE_NO_PREFIX
,
4306 .name
= "swappiness",
4307 .read_u64
= mem_cgroup_swappiness_read
,
4308 .write_u64
= mem_cgroup_swappiness_write
,
4311 .name
= "move_charge_at_immigrate",
4312 .read_u64
= mem_cgroup_move_charge_read
,
4313 .write_u64
= mem_cgroup_move_charge_write
,
4316 .name
= "oom_control",
4317 .seq_show
= mem_cgroup_oom_control_read
,
4318 .write_u64
= mem_cgroup_oom_control_write
,
4319 .private = MEMFILE_PRIVATE(_OOM_TYPE
, OOM_CONTROL
),
4322 .name
= "pressure_level",
4326 .name
= "numa_stat",
4327 .seq_show
= memcg_numa_stat_show
,
4330 #ifdef CONFIG_MEMCG_KMEM
4332 .name
= "kmem.limit_in_bytes",
4333 .private = MEMFILE_PRIVATE(_KMEM
, RES_LIMIT
),
4334 .write
= mem_cgroup_write
,
4335 .read_u64
= mem_cgroup_read_u64
,
4338 .name
= "kmem.usage_in_bytes",
4339 .private = MEMFILE_PRIVATE(_KMEM
, RES_USAGE
),
4340 .read_u64
= mem_cgroup_read_u64
,
4343 .name
= "kmem.failcnt",
4344 .private = MEMFILE_PRIVATE(_KMEM
, RES_FAILCNT
),
4345 .write
= mem_cgroup_reset
,
4346 .read_u64
= mem_cgroup_read_u64
,
4349 .name
= "kmem.max_usage_in_bytes",
4350 .private = MEMFILE_PRIVATE(_KMEM
, RES_MAX_USAGE
),
4351 .write
= mem_cgroup_reset
,
4352 .read_u64
= mem_cgroup_read_u64
,
4354 #ifdef CONFIG_SLABINFO
4356 .name
= "kmem.slabinfo",
4357 .seq_start
= slab_start
,
4358 .seq_next
= slab_next
,
4359 .seq_stop
= slab_stop
,
4360 .seq_show
= memcg_slab_show
,
4364 { }, /* terminate */
4367 static int alloc_mem_cgroup_per_zone_info(struct mem_cgroup
*memcg
, int node
)
4369 struct mem_cgroup_per_node
*pn
;
4370 struct mem_cgroup_per_zone
*mz
;
4371 int zone
, tmp
= node
;
4373 * This routine is called against possible nodes.
4374 * But it's BUG to call kmalloc() against offline node.
4376 * TODO: this routine can waste much memory for nodes which will
4377 * never be onlined. It's better to use memory hotplug callback
4380 if (!node_state(node
, N_NORMAL_MEMORY
))
4382 pn
= kzalloc_node(sizeof(*pn
), GFP_KERNEL
, tmp
);
4386 for (zone
= 0; zone
< MAX_NR_ZONES
; zone
++) {
4387 mz
= &pn
->zoneinfo
[zone
];
4388 lruvec_init(&mz
->lruvec
);
4389 mz
->usage_in_excess
= 0;
4390 mz
->on_tree
= false;
4393 memcg
->nodeinfo
[node
] = pn
;
4397 static void free_mem_cgroup_per_zone_info(struct mem_cgroup
*memcg
, int node
)
4399 kfree(memcg
->nodeinfo
[node
]);
4402 static struct mem_cgroup
*mem_cgroup_alloc(void)
4404 struct mem_cgroup
*memcg
;
4407 size
= sizeof(struct mem_cgroup
);
4408 size
+= nr_node_ids
* sizeof(struct mem_cgroup_per_node
*);
4410 memcg
= kzalloc(size
, GFP_KERNEL
);
4414 memcg
->stat
= alloc_percpu(struct mem_cgroup_stat_cpu
);
4417 spin_lock_init(&memcg
->pcp_counter_lock
);
4426 * At destroying mem_cgroup, references from swap_cgroup can remain.
4427 * (scanning all at force_empty is too costly...)
4429 * Instead of clearing all references at force_empty, we remember
4430 * the number of reference from swap_cgroup and free mem_cgroup when
4431 * it goes down to 0.
4433 * Removal of cgroup itself succeeds regardless of refs from swap.
4436 static void __mem_cgroup_free(struct mem_cgroup
*memcg
)
4440 mem_cgroup_remove_from_trees(memcg
);
4443 free_mem_cgroup_per_zone_info(memcg
, node
);
4445 free_percpu(memcg
->stat
);
4447 disarm_static_keys(memcg
);
4452 * Returns the parent mem_cgroup in memcgroup hierarchy with hierarchy enabled.
4454 struct mem_cgroup
*parent_mem_cgroup(struct mem_cgroup
*memcg
)
4456 if (!memcg
->memory
.parent
)
4458 return mem_cgroup_from_counter(memcg
->memory
.parent
, memory
);
4460 EXPORT_SYMBOL(parent_mem_cgroup
);
4462 static struct cgroup_subsys_state
* __ref
4463 mem_cgroup_css_alloc(struct cgroup_subsys_state
*parent_css
)
4465 struct mem_cgroup
*memcg
;
4466 long error
= -ENOMEM
;
4469 memcg
= mem_cgroup_alloc();
4471 return ERR_PTR(error
);
4474 if (alloc_mem_cgroup_per_zone_info(memcg
, node
))
4478 if (parent_css
== NULL
) {
4479 root_mem_cgroup
= memcg
;
4480 page_counter_init(&memcg
->memory
, NULL
);
4481 memcg
->high
= PAGE_COUNTER_MAX
;
4482 memcg
->soft_limit
= PAGE_COUNTER_MAX
;
4483 page_counter_init(&memcg
->memsw
, NULL
);
4484 page_counter_init(&memcg
->kmem
, NULL
);
4487 memcg
->last_scanned_node
= MAX_NUMNODES
;
4488 INIT_LIST_HEAD(&memcg
->oom_notify
);
4489 memcg
->move_charge_at_immigrate
= 0;
4490 mutex_init(&memcg
->thresholds_lock
);
4491 spin_lock_init(&memcg
->move_lock
);
4492 vmpressure_init(&memcg
->vmpressure
);
4493 INIT_LIST_HEAD(&memcg
->event_list
);
4494 spin_lock_init(&memcg
->event_list_lock
);
4495 #ifdef CONFIG_MEMCG_KMEM
4496 memcg
->kmemcg_id
= -1;
4502 __mem_cgroup_free(memcg
);
4503 return ERR_PTR(error
);
4507 mem_cgroup_css_online(struct cgroup_subsys_state
*css
)
4509 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
4510 struct mem_cgroup
*parent
= mem_cgroup_from_css(css
->parent
);
4513 if (css
->id
> MEM_CGROUP_ID_MAX
)
4519 mutex_lock(&memcg_create_mutex
);
4521 memcg
->use_hierarchy
= parent
->use_hierarchy
;
4522 memcg
->oom_kill_disable
= parent
->oom_kill_disable
;
4523 memcg
->swappiness
= mem_cgroup_swappiness(parent
);
4525 if (parent
->use_hierarchy
) {
4526 page_counter_init(&memcg
->memory
, &parent
->memory
);
4527 memcg
->high
= PAGE_COUNTER_MAX
;
4528 memcg
->soft_limit
= PAGE_COUNTER_MAX
;
4529 page_counter_init(&memcg
->memsw
, &parent
->memsw
);
4530 page_counter_init(&memcg
->kmem
, &parent
->kmem
);
4533 * No need to take a reference to the parent because cgroup
4534 * core guarantees its existence.
4537 page_counter_init(&memcg
->memory
, NULL
);
4538 memcg
->high
= PAGE_COUNTER_MAX
;
4539 memcg
->soft_limit
= PAGE_COUNTER_MAX
;
4540 page_counter_init(&memcg
->memsw
, NULL
);
4541 page_counter_init(&memcg
->kmem
, NULL
);
4543 * Deeper hierachy with use_hierarchy == false doesn't make
4544 * much sense so let cgroup subsystem know about this
4545 * unfortunate state in our controller.
4547 if (parent
!= root_mem_cgroup
)
4548 memory_cgrp_subsys
.broken_hierarchy
= true;
4550 mutex_unlock(&memcg_create_mutex
);
4552 ret
= memcg_init_kmem(memcg
, &memory_cgrp_subsys
);
4557 * Make sure the memcg is initialized: mem_cgroup_iter()
4558 * orders reading memcg->initialized against its callers
4559 * reading the memcg members.
4561 smp_store_release(&memcg
->initialized
, 1);
4566 static void mem_cgroup_css_offline(struct cgroup_subsys_state
*css
)
4568 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
4569 struct mem_cgroup_event
*event
, *tmp
;
4572 * Unregister events and notify userspace.
4573 * Notify userspace about cgroup removing only after rmdir of cgroup
4574 * directory to avoid race between userspace and kernelspace.
4576 spin_lock(&memcg
->event_list_lock
);
4577 list_for_each_entry_safe(event
, tmp
, &memcg
->event_list
, list
) {
4578 list_del_init(&event
->list
);
4579 schedule_work(&event
->remove
);
4581 spin_unlock(&memcg
->event_list_lock
);
4583 vmpressure_cleanup(&memcg
->vmpressure
);
4586 static void mem_cgroup_css_free(struct cgroup_subsys_state
*css
)
4588 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
4590 memcg_destroy_kmem(memcg
);
4591 __mem_cgroup_free(memcg
);
4595 * mem_cgroup_css_reset - reset the states of a mem_cgroup
4596 * @css: the target css
4598 * Reset the states of the mem_cgroup associated with @css. This is
4599 * invoked when the userland requests disabling on the default hierarchy
4600 * but the memcg is pinned through dependency. The memcg should stop
4601 * applying policies and should revert to the vanilla state as it may be
4602 * made visible again.
4604 * The current implementation only resets the essential configurations.
4605 * This needs to be expanded to cover all the visible parts.
4607 static void mem_cgroup_css_reset(struct cgroup_subsys_state
*css
)
4609 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
4611 mem_cgroup_resize_limit(memcg
, PAGE_COUNTER_MAX
);
4612 mem_cgroup_resize_memsw_limit(memcg
, PAGE_COUNTER_MAX
);
4613 memcg_update_kmem_limit(memcg
, PAGE_COUNTER_MAX
);
4615 memcg
->high
= PAGE_COUNTER_MAX
;
4616 memcg
->soft_limit
= PAGE_COUNTER_MAX
;
4620 /* Handlers for move charge at task migration. */
4621 static int mem_cgroup_do_precharge(unsigned long count
)
4625 /* Try a single bulk charge without reclaim first */
4626 ret
= try_charge(mc
.to
, GFP_KERNEL
& ~__GFP_WAIT
, count
);
4628 mc
.precharge
+= count
;
4631 if (ret
== -EINTR
) {
4632 cancel_charge(root_mem_cgroup
, count
);
4636 /* Try charges one by one with reclaim */
4638 ret
= try_charge(mc
.to
, GFP_KERNEL
& ~__GFP_NORETRY
, 1);
4640 * In case of failure, any residual charges against
4641 * mc.to will be dropped by mem_cgroup_clear_mc()
4642 * later on. However, cancel any charges that are
4643 * bypassed to root right away or they'll be lost.
4646 cancel_charge(root_mem_cgroup
, 1);
4656 * get_mctgt_type - get target type of moving charge
4657 * @vma: the vma the pte to be checked belongs
4658 * @addr: the address corresponding to the pte to be checked
4659 * @ptent: the pte to be checked
4660 * @target: the pointer the target page or swap ent will be stored(can be NULL)
4663 * 0(MC_TARGET_NONE): if the pte is not a target for move charge.
4664 * 1(MC_TARGET_PAGE): if the page corresponding to this pte is a target for
4665 * move charge. if @target is not NULL, the page is stored in target->page
4666 * with extra refcnt got(Callers should handle it).
4667 * 2(MC_TARGET_SWAP): if the swap entry corresponding to this pte is a
4668 * target for charge migration. if @target is not NULL, the entry is stored
4671 * Called with pte lock held.
4678 enum mc_target_type
{
4684 static struct page
*mc_handle_present_pte(struct vm_area_struct
*vma
,
4685 unsigned long addr
, pte_t ptent
)
4687 struct page
*page
= vm_normal_page(vma
, addr
, ptent
);
4689 if (!page
|| !page_mapped(page
))
4691 if (PageAnon(page
)) {
4692 if (!(mc
.flags
& MOVE_ANON
))
4695 if (!(mc
.flags
& MOVE_FILE
))
4698 if (!get_page_unless_zero(page
))
4705 static struct page
*mc_handle_swap_pte(struct vm_area_struct
*vma
,
4706 unsigned long addr
, pte_t ptent
, swp_entry_t
*entry
)
4708 struct page
*page
= NULL
;
4709 swp_entry_t ent
= pte_to_swp_entry(ptent
);
4711 if (!(mc
.flags
& MOVE_ANON
) || non_swap_entry(ent
))
4714 * Because lookup_swap_cache() updates some statistics counter,
4715 * we call find_get_page() with swapper_space directly.
4717 page
= find_get_page(swap_address_space(ent
), ent
.val
);
4718 if (do_swap_account
)
4719 entry
->val
= ent
.val
;
4724 static struct page
*mc_handle_swap_pte(struct vm_area_struct
*vma
,
4725 unsigned long addr
, pte_t ptent
, swp_entry_t
*entry
)
4731 static struct page
*mc_handle_file_pte(struct vm_area_struct
*vma
,
4732 unsigned long addr
, pte_t ptent
, swp_entry_t
*entry
)
4734 struct page
*page
= NULL
;
4735 struct address_space
*mapping
;
4738 if (!vma
->vm_file
) /* anonymous vma */
4740 if (!(mc
.flags
& MOVE_FILE
))
4743 mapping
= vma
->vm_file
->f_mapping
;
4744 pgoff
= linear_page_index(vma
, addr
);
4746 /* page is moved even if it's not RSS of this task(page-faulted). */
4748 /* shmem/tmpfs may report page out on swap: account for that too. */
4749 if (shmem_mapping(mapping
)) {
4750 page
= find_get_entry(mapping
, pgoff
);
4751 if (radix_tree_exceptional_entry(page
)) {
4752 swp_entry_t swp
= radix_to_swp_entry(page
);
4753 if (do_swap_account
)
4755 page
= find_get_page(swap_address_space(swp
), swp
.val
);
4758 page
= find_get_page(mapping
, pgoff
);
4760 page
= find_get_page(mapping
, pgoff
);
4765 static enum mc_target_type
get_mctgt_type(struct vm_area_struct
*vma
,
4766 unsigned long addr
, pte_t ptent
, union mc_target
*target
)
4768 struct page
*page
= NULL
;
4769 enum mc_target_type ret
= MC_TARGET_NONE
;
4770 swp_entry_t ent
= { .val
= 0 };
4772 if (pte_present(ptent
))
4773 page
= mc_handle_present_pte(vma
, addr
, ptent
);
4774 else if (is_swap_pte(ptent
))
4775 page
= mc_handle_swap_pte(vma
, addr
, ptent
, &ent
);
4776 else if (pte_none(ptent
))
4777 page
= mc_handle_file_pte(vma
, addr
, ptent
, &ent
);
4779 if (!page
&& !ent
.val
)
4783 * Do only loose check w/o serialization.
4784 * mem_cgroup_move_account() checks the page is valid or
4785 * not under LRU exclusion.
4787 if (page
->mem_cgroup
== mc
.from
) {
4788 ret
= MC_TARGET_PAGE
;
4790 target
->page
= page
;
4792 if (!ret
|| !target
)
4795 /* There is a swap entry and a page doesn't exist or isn't charged */
4796 if (ent
.val
&& !ret
&&
4797 mem_cgroup_id(mc
.from
) == lookup_swap_cgroup_id(ent
)) {
4798 ret
= MC_TARGET_SWAP
;
4805 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
4807 * We don't consider swapping or file mapped pages because THP does not
4808 * support them for now.
4809 * Caller should make sure that pmd_trans_huge(pmd) is true.
4811 static enum mc_target_type
get_mctgt_type_thp(struct vm_area_struct
*vma
,
4812 unsigned long addr
, pmd_t pmd
, union mc_target
*target
)
4814 struct page
*page
= NULL
;
4815 enum mc_target_type ret
= MC_TARGET_NONE
;
4817 page
= pmd_page(pmd
);
4818 VM_BUG_ON_PAGE(!page
|| !PageHead(page
), page
);
4819 if (!(mc
.flags
& MOVE_ANON
))
4821 if (page
->mem_cgroup
== mc
.from
) {
4822 ret
= MC_TARGET_PAGE
;
4825 target
->page
= page
;
4831 static inline enum mc_target_type
get_mctgt_type_thp(struct vm_area_struct
*vma
,
4832 unsigned long addr
, pmd_t pmd
, union mc_target
*target
)
4834 return MC_TARGET_NONE
;
4838 static int mem_cgroup_count_precharge_pte_range(pmd_t
*pmd
,
4839 unsigned long addr
, unsigned long end
,
4840 struct mm_walk
*walk
)
4842 struct vm_area_struct
*vma
= walk
->vma
;
4846 if (pmd_trans_huge_lock(pmd
, vma
, &ptl
) == 1) {
4847 if (get_mctgt_type_thp(vma
, addr
, *pmd
, NULL
) == MC_TARGET_PAGE
)
4848 mc
.precharge
+= HPAGE_PMD_NR
;
4853 if (pmd_trans_unstable(pmd
))
4855 pte
= pte_offset_map_lock(vma
->vm_mm
, pmd
, addr
, &ptl
);
4856 for (; addr
!= end
; pte
++, addr
+= PAGE_SIZE
)
4857 if (get_mctgt_type(vma
, addr
, *pte
, NULL
))
4858 mc
.precharge
++; /* increment precharge temporarily */
4859 pte_unmap_unlock(pte
- 1, ptl
);
4865 static unsigned long mem_cgroup_count_precharge(struct mm_struct
*mm
)
4867 unsigned long precharge
;
4869 struct mm_walk mem_cgroup_count_precharge_walk
= {
4870 .pmd_entry
= mem_cgroup_count_precharge_pte_range
,
4873 down_read(&mm
->mmap_sem
);
4874 walk_page_range(0, ~0UL, &mem_cgroup_count_precharge_walk
);
4875 up_read(&mm
->mmap_sem
);
4877 precharge
= mc
.precharge
;
4883 static int mem_cgroup_precharge_mc(struct mm_struct
*mm
)
4885 unsigned long precharge
= mem_cgroup_count_precharge(mm
);
4887 VM_BUG_ON(mc
.moving_task
);
4888 mc
.moving_task
= current
;
4889 return mem_cgroup_do_precharge(precharge
);
4892 /* cancels all extra charges on mc.from and mc.to, and wakes up all waiters. */
4893 static void __mem_cgroup_clear_mc(void)
4895 struct mem_cgroup
*from
= mc
.from
;
4896 struct mem_cgroup
*to
= mc
.to
;
4898 /* we must uncharge all the leftover precharges from mc.to */
4900 cancel_charge(mc
.to
, mc
.precharge
);
4904 * we didn't uncharge from mc.from at mem_cgroup_move_account(), so
4905 * we must uncharge here.
4907 if (mc
.moved_charge
) {
4908 cancel_charge(mc
.from
, mc
.moved_charge
);
4909 mc
.moved_charge
= 0;
4911 /* we must fixup refcnts and charges */
4912 if (mc
.moved_swap
) {
4913 /* uncharge swap account from the old cgroup */
4914 if (!mem_cgroup_is_root(mc
.from
))
4915 page_counter_uncharge(&mc
.from
->memsw
, mc
.moved_swap
);
4918 * we charged both to->memory and to->memsw, so we
4919 * should uncharge to->memory.
4921 if (!mem_cgroup_is_root(mc
.to
))
4922 page_counter_uncharge(&mc
.to
->memory
, mc
.moved_swap
);
4924 css_put_many(&mc
.from
->css
, mc
.moved_swap
);
4926 /* we've already done css_get(mc.to) */
4929 memcg_oom_recover(from
);
4930 memcg_oom_recover(to
);
4931 wake_up_all(&mc
.waitq
);
4934 static void mem_cgroup_clear_mc(void)
4937 * we must clear moving_task before waking up waiters at the end of
4940 mc
.moving_task
= NULL
;
4941 __mem_cgroup_clear_mc();
4942 spin_lock(&mc
.lock
);
4945 spin_unlock(&mc
.lock
);
4948 static int mem_cgroup_can_attach(struct cgroup_subsys_state
*css
,
4949 struct cgroup_taskset
*tset
)
4951 struct task_struct
*p
= cgroup_taskset_first(tset
);
4953 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
4954 unsigned long move_flags
;
4957 * We are now commited to this value whatever it is. Changes in this
4958 * tunable will only affect upcoming migrations, not the current one.
4959 * So we need to save it, and keep it going.
4961 move_flags
= ACCESS_ONCE(memcg
->move_charge_at_immigrate
);
4963 struct mm_struct
*mm
;
4964 struct mem_cgroup
*from
= mem_cgroup_from_task(p
);
4966 VM_BUG_ON(from
== memcg
);
4968 mm
= get_task_mm(p
);
4971 /* We move charges only when we move a owner of the mm */
4972 if (mm
->owner
== p
) {
4975 VM_BUG_ON(mc
.precharge
);
4976 VM_BUG_ON(mc
.moved_charge
);
4977 VM_BUG_ON(mc
.moved_swap
);
4979 spin_lock(&mc
.lock
);
4982 mc
.flags
= move_flags
;
4983 spin_unlock(&mc
.lock
);
4984 /* We set mc.moving_task later */
4986 ret
= mem_cgroup_precharge_mc(mm
);
4988 mem_cgroup_clear_mc();
4995 static void mem_cgroup_cancel_attach(struct cgroup_subsys_state
*css
,
4996 struct cgroup_taskset
*tset
)
4999 mem_cgroup_clear_mc();
5002 static int mem_cgroup_move_charge_pte_range(pmd_t
*pmd
,
5003 unsigned long addr
, unsigned long end
,
5004 struct mm_walk
*walk
)
5007 struct vm_area_struct
*vma
= walk
->vma
;
5010 enum mc_target_type target_type
;
5011 union mc_target target
;
5015 * We don't take compound_lock() here but no race with splitting thp
5017 * - if pmd_trans_huge_lock() returns 1, the relevant thp is not
5018 * under splitting, which means there's no concurrent thp split,
5019 * - if another thread runs into split_huge_page() just after we
5020 * entered this if-block, the thread must wait for page table lock
5021 * to be unlocked in __split_huge_page_splitting(), where the main
5022 * part of thp split is not executed yet.
5024 if (pmd_trans_huge_lock(pmd
, vma
, &ptl
) == 1) {
5025 if (mc
.precharge
< HPAGE_PMD_NR
) {
5029 target_type
= get_mctgt_type_thp(vma
, addr
, *pmd
, &target
);
5030 if (target_type
== MC_TARGET_PAGE
) {
5032 if (!isolate_lru_page(page
)) {
5033 if (!mem_cgroup_move_account(page
, HPAGE_PMD_NR
,
5035 mc
.precharge
-= HPAGE_PMD_NR
;
5036 mc
.moved_charge
+= HPAGE_PMD_NR
;
5038 putback_lru_page(page
);
5046 if (pmd_trans_unstable(pmd
))
5049 pte
= pte_offset_map_lock(vma
->vm_mm
, pmd
, addr
, &ptl
);
5050 for (; addr
!= end
; addr
+= PAGE_SIZE
) {
5051 pte_t ptent
= *(pte
++);
5057 switch (get_mctgt_type(vma
, addr
, ptent
, &target
)) {
5058 case MC_TARGET_PAGE
:
5060 if (isolate_lru_page(page
))
5062 if (!mem_cgroup_move_account(page
, 1, mc
.from
, mc
.to
)) {
5064 /* we uncharge from mc.from later. */
5067 putback_lru_page(page
);
5068 put
: /* get_mctgt_type() gets the page */
5071 case MC_TARGET_SWAP
:
5073 if (!mem_cgroup_move_swap_account(ent
, mc
.from
, mc
.to
)) {
5075 /* we fixup refcnts and charges later. */
5083 pte_unmap_unlock(pte
- 1, ptl
);
5088 * We have consumed all precharges we got in can_attach().
5089 * We try charge one by one, but don't do any additional
5090 * charges to mc.to if we have failed in charge once in attach()
5093 ret
= mem_cgroup_do_precharge(1);
5101 static void mem_cgroup_move_charge(struct mm_struct
*mm
)
5103 struct mm_walk mem_cgroup_move_charge_walk
= {
5104 .pmd_entry
= mem_cgroup_move_charge_pte_range
,
5108 lru_add_drain_all();
5110 * Signal mem_cgroup_begin_page_stat() to take the memcg's
5111 * move_lock while we're moving its pages to another memcg.
5112 * Then wait for already started RCU-only updates to finish.
5114 atomic_inc(&mc
.from
->moving_account
);
5117 if (unlikely(!down_read_trylock(&mm
->mmap_sem
))) {
5119 * Someone who are holding the mmap_sem might be waiting in
5120 * waitq. So we cancel all extra charges, wake up all waiters,
5121 * and retry. Because we cancel precharges, we might not be able
5122 * to move enough charges, but moving charge is a best-effort
5123 * feature anyway, so it wouldn't be a big problem.
5125 __mem_cgroup_clear_mc();
5130 * When we have consumed all precharges and failed in doing
5131 * additional charge, the page walk just aborts.
5133 walk_page_range(0, ~0UL, &mem_cgroup_move_charge_walk
);
5134 up_read(&mm
->mmap_sem
);
5135 atomic_dec(&mc
.from
->moving_account
);
5138 static void mem_cgroup_move_task(struct cgroup_subsys_state
*css
,
5139 struct cgroup_taskset
*tset
)
5141 struct task_struct
*p
= cgroup_taskset_first(tset
);
5142 struct mm_struct
*mm
= get_task_mm(p
);
5146 mem_cgroup_move_charge(mm
);
5150 mem_cgroup_clear_mc();
5152 #else /* !CONFIG_MMU */
5153 static int mem_cgroup_can_attach(struct cgroup_subsys_state
*css
,
5154 struct cgroup_taskset
*tset
)
5158 static void mem_cgroup_cancel_attach(struct cgroup_subsys_state
*css
,
5159 struct cgroup_taskset
*tset
)
5162 static void mem_cgroup_move_task(struct cgroup_subsys_state
*css
,
5163 struct cgroup_taskset
*tset
)
5169 * Cgroup retains root cgroups across [un]mount cycles making it necessary
5170 * to verify whether we're attached to the default hierarchy on each mount
5173 static void mem_cgroup_bind(struct cgroup_subsys_state
*root_css
)
5176 * use_hierarchy is forced on the default hierarchy. cgroup core
5177 * guarantees that @root doesn't have any children, so turning it
5178 * on for the root memcg is enough.
5180 if (cgroup_on_dfl(root_css
->cgroup
))
5181 mem_cgroup_from_css(root_css
)->use_hierarchy
= true;
5184 static u64
memory_current_read(struct cgroup_subsys_state
*css
,
5187 return mem_cgroup_usage(mem_cgroup_from_css(css
), false);
5190 static int memory_low_show(struct seq_file
*m
, void *v
)
5192 struct mem_cgroup
*memcg
= mem_cgroup_from_css(seq_css(m
));
5193 unsigned long low
= ACCESS_ONCE(memcg
->low
);
5195 if (low
== PAGE_COUNTER_MAX
)
5196 seq_puts(m
, "infinity\n");
5198 seq_printf(m
, "%llu\n", (u64
)low
* PAGE_SIZE
);
5203 static ssize_t
memory_low_write(struct kernfs_open_file
*of
,
5204 char *buf
, size_t nbytes
, loff_t off
)
5206 struct mem_cgroup
*memcg
= mem_cgroup_from_css(of_css(of
));
5210 buf
= strstrip(buf
);
5211 err
= page_counter_memparse(buf
, "infinity", &low
);
5220 static int memory_high_show(struct seq_file
*m
, void *v
)
5222 struct mem_cgroup
*memcg
= mem_cgroup_from_css(seq_css(m
));
5223 unsigned long high
= ACCESS_ONCE(memcg
->high
);
5225 if (high
== PAGE_COUNTER_MAX
)
5226 seq_puts(m
, "infinity\n");
5228 seq_printf(m
, "%llu\n", (u64
)high
* PAGE_SIZE
);
5233 static ssize_t
memory_high_write(struct kernfs_open_file
*of
,
5234 char *buf
, size_t nbytes
, loff_t off
)
5236 struct mem_cgroup
*memcg
= mem_cgroup_from_css(of_css(of
));
5240 buf
= strstrip(buf
);
5241 err
= page_counter_memparse(buf
, "infinity", &high
);
5250 static int memory_max_show(struct seq_file
*m
, void *v
)
5252 struct mem_cgroup
*memcg
= mem_cgroup_from_css(seq_css(m
));
5253 unsigned long max
= ACCESS_ONCE(memcg
->memory
.limit
);
5255 if (max
== PAGE_COUNTER_MAX
)
5256 seq_puts(m
, "infinity\n");
5258 seq_printf(m
, "%llu\n", (u64
)max
* PAGE_SIZE
);
5263 static ssize_t
memory_max_write(struct kernfs_open_file
*of
,
5264 char *buf
, size_t nbytes
, loff_t off
)
5266 struct mem_cgroup
*memcg
= mem_cgroup_from_css(of_css(of
));
5270 buf
= strstrip(buf
);
5271 err
= page_counter_memparse(buf
, "infinity", &max
);
5275 err
= mem_cgroup_resize_limit(memcg
, max
);
5282 static int memory_events_show(struct seq_file
*m
, void *v
)
5284 struct mem_cgroup
*memcg
= mem_cgroup_from_css(seq_css(m
));
5286 seq_printf(m
, "low %lu\n", mem_cgroup_read_events(memcg
, MEMCG_LOW
));
5287 seq_printf(m
, "high %lu\n", mem_cgroup_read_events(memcg
, MEMCG_HIGH
));
5288 seq_printf(m
, "max %lu\n", mem_cgroup_read_events(memcg
, MEMCG_MAX
));
5289 seq_printf(m
, "oom %lu\n", mem_cgroup_read_events(memcg
, MEMCG_OOM
));
5294 static struct cftype memory_files
[] = {
5297 .read_u64
= memory_current_read
,
5301 .flags
= CFTYPE_NOT_ON_ROOT
,
5302 .seq_show
= memory_low_show
,
5303 .write
= memory_low_write
,
5307 .flags
= CFTYPE_NOT_ON_ROOT
,
5308 .seq_show
= memory_high_show
,
5309 .write
= memory_high_write
,
5313 .flags
= CFTYPE_NOT_ON_ROOT
,
5314 .seq_show
= memory_max_show
,
5315 .write
= memory_max_write
,
5319 .flags
= CFTYPE_NOT_ON_ROOT
,
5320 .seq_show
= memory_events_show
,
5325 struct cgroup_subsys memory_cgrp_subsys
= {
5326 .css_alloc
= mem_cgroup_css_alloc
,
5327 .css_online
= mem_cgroup_css_online
,
5328 .css_offline
= mem_cgroup_css_offline
,
5329 .css_free
= mem_cgroup_css_free
,
5330 .css_reset
= mem_cgroup_css_reset
,
5331 .can_attach
= mem_cgroup_can_attach
,
5332 .cancel_attach
= mem_cgroup_cancel_attach
,
5333 .attach
= mem_cgroup_move_task
,
5334 .bind
= mem_cgroup_bind
,
5335 .dfl_cftypes
= memory_files
,
5336 .legacy_cftypes
= mem_cgroup_legacy_files
,
5341 * mem_cgroup_events - count memory events against a cgroup
5342 * @memcg: the memory cgroup
5343 * @idx: the event index
5344 * @nr: the number of events to account for
5346 void mem_cgroup_events(struct mem_cgroup
*memcg
,
5347 enum mem_cgroup_events_index idx
,
5350 this_cpu_add(memcg
->stat
->events
[idx
], nr
);
5354 * mem_cgroup_low - check if memory consumption is below the normal range
5355 * @root: the highest ancestor to consider
5356 * @memcg: the memory cgroup to check
5358 * Returns %true if memory consumption of @memcg, and that of all
5359 * configurable ancestors up to @root, is below the normal range.
5361 bool mem_cgroup_low(struct mem_cgroup
*root
, struct mem_cgroup
*memcg
)
5363 if (mem_cgroup_disabled())
5367 * The toplevel group doesn't have a configurable range, so
5368 * it's never low when looked at directly, and it is not
5369 * considered an ancestor when assessing the hierarchy.
5372 if (memcg
== root_mem_cgroup
)
5375 if (page_counter_read(&memcg
->memory
) > memcg
->low
)
5378 while (memcg
!= root
) {
5379 memcg
= parent_mem_cgroup(memcg
);
5381 if (memcg
== root_mem_cgroup
)
5384 if (page_counter_read(&memcg
->memory
) > memcg
->low
)
5391 * mem_cgroup_try_charge - try charging a page
5392 * @page: page to charge
5393 * @mm: mm context of the victim
5394 * @gfp_mask: reclaim mode
5395 * @memcgp: charged memcg return
5397 * Try to charge @page to the memcg that @mm belongs to, reclaiming
5398 * pages according to @gfp_mask if necessary.
5400 * Returns 0 on success, with *@memcgp pointing to the charged memcg.
5401 * Otherwise, an error code is returned.
5403 * After page->mapping has been set up, the caller must finalize the
5404 * charge with mem_cgroup_commit_charge(). Or abort the transaction
5405 * with mem_cgroup_cancel_charge() in case page instantiation fails.
5407 int mem_cgroup_try_charge(struct page
*page
, struct mm_struct
*mm
,
5408 gfp_t gfp_mask
, struct mem_cgroup
**memcgp
)
5410 struct mem_cgroup
*memcg
= NULL
;
5411 unsigned int nr_pages
= 1;
5414 if (mem_cgroup_disabled())
5417 if (PageSwapCache(page
)) {
5419 * Every swap fault against a single page tries to charge the
5420 * page, bail as early as possible. shmem_unuse() encounters
5421 * already charged pages, too. The USED bit is protected by
5422 * the page lock, which serializes swap cache removal, which
5423 * in turn serializes uncharging.
5425 if (page
->mem_cgroup
)
5429 if (PageTransHuge(page
)) {
5430 nr_pages
<<= compound_order(page
);
5431 VM_BUG_ON_PAGE(!PageTransHuge(page
), page
);
5434 if (do_swap_account
&& PageSwapCache(page
))
5435 memcg
= try_get_mem_cgroup_from_page(page
);
5437 memcg
= get_mem_cgroup_from_mm(mm
);
5439 ret
= try_charge(memcg
, gfp_mask
, nr_pages
);
5441 css_put(&memcg
->css
);
5443 if (ret
== -EINTR
) {
5444 memcg
= root_mem_cgroup
;
5453 * mem_cgroup_commit_charge - commit a page charge
5454 * @page: page to charge
5455 * @memcg: memcg to charge the page to
5456 * @lrucare: page might be on LRU already
5458 * Finalize a charge transaction started by mem_cgroup_try_charge(),
5459 * after page->mapping has been set up. This must happen atomically
5460 * as part of the page instantiation, i.e. under the page table lock
5461 * for anonymous pages, under the page lock for page and swap cache.
5463 * In addition, the page must not be on the LRU during the commit, to
5464 * prevent racing with task migration. If it might be, use @lrucare.
5466 * Use mem_cgroup_cancel_charge() to cancel the transaction instead.
5468 void mem_cgroup_commit_charge(struct page
*page
, struct mem_cgroup
*memcg
,
5471 unsigned int nr_pages
= 1;
5473 VM_BUG_ON_PAGE(!page
->mapping
, page
);
5474 VM_BUG_ON_PAGE(PageLRU(page
) && !lrucare
, page
);
5476 if (mem_cgroup_disabled())
5479 * Swap faults will attempt to charge the same page multiple
5480 * times. But reuse_swap_page() might have removed the page
5481 * from swapcache already, so we can't check PageSwapCache().
5486 commit_charge(page
, memcg
, lrucare
);
5488 if (PageTransHuge(page
)) {
5489 nr_pages
<<= compound_order(page
);
5490 VM_BUG_ON_PAGE(!PageTransHuge(page
), page
);
5493 local_irq_disable();
5494 mem_cgroup_charge_statistics(memcg
, page
, nr_pages
);
5495 memcg_check_events(memcg
, page
);
5498 if (do_swap_account
&& PageSwapCache(page
)) {
5499 swp_entry_t entry
= { .val
= page_private(page
) };
5501 * The swap entry might not get freed for a long time,
5502 * let's not wait for it. The page already received a
5503 * memory+swap charge, drop the swap entry duplicate.
5505 mem_cgroup_uncharge_swap(entry
);
5510 * mem_cgroup_cancel_charge - cancel a page charge
5511 * @page: page to charge
5512 * @memcg: memcg to charge the page to
5514 * Cancel a charge transaction started by mem_cgroup_try_charge().
5516 void mem_cgroup_cancel_charge(struct page
*page
, struct mem_cgroup
*memcg
)
5518 unsigned int nr_pages
= 1;
5520 if (mem_cgroup_disabled())
5523 * Swap faults will attempt to charge the same page multiple
5524 * times. But reuse_swap_page() might have removed the page
5525 * from swapcache already, so we can't check PageSwapCache().
5530 if (PageTransHuge(page
)) {
5531 nr_pages
<<= compound_order(page
);
5532 VM_BUG_ON_PAGE(!PageTransHuge(page
), page
);
5535 cancel_charge(memcg
, nr_pages
);
5538 static void uncharge_batch(struct mem_cgroup
*memcg
, unsigned long pgpgout
,
5539 unsigned long nr_anon
, unsigned long nr_file
,
5540 unsigned long nr_huge
, struct page
*dummy_page
)
5542 unsigned long nr_pages
= nr_anon
+ nr_file
;
5543 unsigned long flags
;
5545 if (!mem_cgroup_is_root(memcg
)) {
5546 page_counter_uncharge(&memcg
->memory
, nr_pages
);
5547 if (do_swap_account
)
5548 page_counter_uncharge(&memcg
->memsw
, nr_pages
);
5549 memcg_oom_recover(memcg
);
5552 local_irq_save(flags
);
5553 __this_cpu_sub(memcg
->stat
->count
[MEM_CGROUP_STAT_RSS
], nr_anon
);
5554 __this_cpu_sub(memcg
->stat
->count
[MEM_CGROUP_STAT_CACHE
], nr_file
);
5555 __this_cpu_sub(memcg
->stat
->count
[MEM_CGROUP_STAT_RSS_HUGE
], nr_huge
);
5556 __this_cpu_add(memcg
->stat
->events
[MEM_CGROUP_EVENTS_PGPGOUT
], pgpgout
);
5557 __this_cpu_add(memcg
->stat
->nr_page_events
, nr_pages
);
5558 memcg_check_events(memcg
, dummy_page
);
5559 local_irq_restore(flags
);
5561 if (!mem_cgroup_is_root(memcg
))
5562 css_put_many(&memcg
->css
, nr_pages
);
5565 static void uncharge_list(struct list_head
*page_list
)
5567 struct mem_cgroup
*memcg
= NULL
;
5568 unsigned long nr_anon
= 0;
5569 unsigned long nr_file
= 0;
5570 unsigned long nr_huge
= 0;
5571 unsigned long pgpgout
= 0;
5572 struct list_head
*next
;
5575 next
= page_list
->next
;
5577 unsigned int nr_pages
= 1;
5579 page
= list_entry(next
, struct page
, lru
);
5580 next
= page
->lru
.next
;
5582 VM_BUG_ON_PAGE(PageLRU(page
), page
);
5583 VM_BUG_ON_PAGE(page_count(page
), page
);
5585 if (!page
->mem_cgroup
)
5589 * Nobody should be changing or seriously looking at
5590 * page->mem_cgroup at this point, we have fully
5591 * exclusive access to the page.
5594 if (memcg
!= page
->mem_cgroup
) {
5596 uncharge_batch(memcg
, pgpgout
, nr_anon
, nr_file
,
5598 pgpgout
= nr_anon
= nr_file
= nr_huge
= 0;
5600 memcg
= page
->mem_cgroup
;
5603 if (PageTransHuge(page
)) {
5604 nr_pages
<<= compound_order(page
);
5605 VM_BUG_ON_PAGE(!PageTransHuge(page
), page
);
5606 nr_huge
+= nr_pages
;
5610 nr_anon
+= nr_pages
;
5612 nr_file
+= nr_pages
;
5614 page
->mem_cgroup
= NULL
;
5617 } while (next
!= page_list
);
5620 uncharge_batch(memcg
, pgpgout
, nr_anon
, nr_file
,
5625 * mem_cgroup_uncharge - uncharge a page
5626 * @page: page to uncharge
5628 * Uncharge a page previously charged with mem_cgroup_try_charge() and
5629 * mem_cgroup_commit_charge().
5631 void mem_cgroup_uncharge(struct page
*page
)
5633 if (mem_cgroup_disabled())
5636 /* Don't touch page->lru of any random page, pre-check: */
5637 if (!page
->mem_cgroup
)
5640 INIT_LIST_HEAD(&page
->lru
);
5641 uncharge_list(&page
->lru
);
5645 * mem_cgroup_uncharge_list - uncharge a list of page
5646 * @page_list: list of pages to uncharge
5648 * Uncharge a list of pages previously charged with
5649 * mem_cgroup_try_charge() and mem_cgroup_commit_charge().
5651 void mem_cgroup_uncharge_list(struct list_head
*page_list
)
5653 if (mem_cgroup_disabled())
5656 if (!list_empty(page_list
))
5657 uncharge_list(page_list
);
5661 * mem_cgroup_migrate - migrate a charge to another page
5662 * @oldpage: currently charged page
5663 * @newpage: page to transfer the charge to
5664 * @lrucare: either or both pages might be on the LRU already
5666 * Migrate the charge from @oldpage to @newpage.
5668 * Both pages must be locked, @newpage->mapping must be set up.
5670 void mem_cgroup_migrate(struct page
*oldpage
, struct page
*newpage
,
5673 struct mem_cgroup
*memcg
;
5676 VM_BUG_ON_PAGE(!PageLocked(oldpage
), oldpage
);
5677 VM_BUG_ON_PAGE(!PageLocked(newpage
), newpage
);
5678 VM_BUG_ON_PAGE(!lrucare
&& PageLRU(oldpage
), oldpage
);
5679 VM_BUG_ON_PAGE(!lrucare
&& PageLRU(newpage
), newpage
);
5680 VM_BUG_ON_PAGE(PageAnon(oldpage
) != PageAnon(newpage
), newpage
);
5681 VM_BUG_ON_PAGE(PageTransHuge(oldpage
) != PageTransHuge(newpage
),
5684 if (mem_cgroup_disabled())
5687 /* Page cache replacement: new page already charged? */
5688 if (newpage
->mem_cgroup
)
5692 * Swapcache readahead pages can get migrated before being
5693 * charged, and migration from compaction can happen to an
5694 * uncharged page when the PFN walker finds a page that
5695 * reclaim just put back on the LRU but has not released yet.
5697 memcg
= oldpage
->mem_cgroup
;
5702 lock_page_lru(oldpage
, &isolated
);
5704 oldpage
->mem_cgroup
= NULL
;
5707 unlock_page_lru(oldpage
, isolated
);
5709 commit_charge(newpage
, memcg
, lrucare
);
5713 * subsys_initcall() for memory controller.
5715 * Some parts like hotcpu_notifier() have to be initialized from this context
5716 * because of lock dependencies (cgroup_lock -> cpu hotplug) but basically
5717 * everything that doesn't depend on a specific mem_cgroup structure should
5718 * be initialized from here.
5720 static int __init
mem_cgroup_init(void)
5724 hotcpu_notifier(memcg_cpu_hotplug_callback
, 0);
5726 for_each_possible_cpu(cpu
)
5727 INIT_WORK(&per_cpu_ptr(&memcg_stock
, cpu
)->work
,
5730 for_each_node(node
) {
5731 struct mem_cgroup_tree_per_node
*rtpn
;
5734 rtpn
= kzalloc_node(sizeof(*rtpn
), GFP_KERNEL
,
5735 node_online(node
) ? node
: NUMA_NO_NODE
);
5737 for (zone
= 0; zone
< MAX_NR_ZONES
; zone
++) {
5738 struct mem_cgroup_tree_per_zone
*rtpz
;
5740 rtpz
= &rtpn
->rb_tree_per_zone
[zone
];
5741 rtpz
->rb_root
= RB_ROOT
;
5742 spin_lock_init(&rtpz
->lock
);
5744 soft_limit_tree
.rb_tree_per_node
[node
] = rtpn
;
5749 subsys_initcall(mem_cgroup_init
);
5751 #ifdef CONFIG_MEMCG_SWAP
5753 * mem_cgroup_swapout - transfer a memsw charge to swap
5754 * @page: page whose memsw charge to transfer
5755 * @entry: swap entry to move the charge to
5757 * Transfer the memsw charge of @page to @entry.
5759 void mem_cgroup_swapout(struct page
*page
, swp_entry_t entry
)
5761 struct mem_cgroup
*memcg
;
5762 unsigned short oldid
;
5764 VM_BUG_ON_PAGE(PageLRU(page
), page
);
5765 VM_BUG_ON_PAGE(page_count(page
), page
);
5767 if (!do_swap_account
)
5770 memcg
= page
->mem_cgroup
;
5772 /* Readahead page, never charged */
5776 oldid
= swap_cgroup_record(entry
, mem_cgroup_id(memcg
));
5777 VM_BUG_ON_PAGE(oldid
, page
);
5778 mem_cgroup_swap_statistics(memcg
, true);
5780 page
->mem_cgroup
= NULL
;
5782 if (!mem_cgroup_is_root(memcg
))
5783 page_counter_uncharge(&memcg
->memory
, 1);
5785 /* XXX: caller holds IRQ-safe mapping->tree_lock */
5786 VM_BUG_ON(!irqs_disabled());
5788 mem_cgroup_charge_statistics(memcg
, page
, -1);
5789 memcg_check_events(memcg
, page
);
5793 * mem_cgroup_uncharge_swap - uncharge a swap entry
5794 * @entry: swap entry to uncharge
5796 * Drop the memsw charge associated with @entry.
5798 void mem_cgroup_uncharge_swap(swp_entry_t entry
)
5800 struct mem_cgroup
*memcg
;
5803 if (!do_swap_account
)
5806 id
= swap_cgroup_record(entry
, 0);
5808 memcg
= mem_cgroup_lookup(id
);
5810 if (!mem_cgroup_is_root(memcg
))
5811 page_counter_uncharge(&memcg
->memsw
, 1);
5812 mem_cgroup_swap_statistics(memcg
, false);
5813 css_put(&memcg
->css
);
5818 /* for remember boot option*/
5819 #ifdef CONFIG_MEMCG_SWAP_ENABLED
5820 static int really_do_swap_account __initdata
= 1;
5822 static int really_do_swap_account __initdata
;
5825 static int __init
enable_swap_account(char *s
)
5827 if (!strcmp(s
, "1"))
5828 really_do_swap_account
= 1;
5829 else if (!strcmp(s
, "0"))
5830 really_do_swap_account
= 0;
5833 __setup("swapaccount=", enable_swap_account
);
5835 static struct cftype memsw_cgroup_files
[] = {
5837 .name
= "memsw.usage_in_bytes",
5838 .private = MEMFILE_PRIVATE(_MEMSWAP
, RES_USAGE
),
5839 .read_u64
= mem_cgroup_read_u64
,
5842 .name
= "memsw.max_usage_in_bytes",
5843 .private = MEMFILE_PRIVATE(_MEMSWAP
, RES_MAX_USAGE
),
5844 .write
= mem_cgroup_reset
,
5845 .read_u64
= mem_cgroup_read_u64
,
5848 .name
= "memsw.limit_in_bytes",
5849 .private = MEMFILE_PRIVATE(_MEMSWAP
, RES_LIMIT
),
5850 .write
= mem_cgroup_write
,
5851 .read_u64
= mem_cgroup_read_u64
,
5854 .name
= "memsw.failcnt",
5855 .private = MEMFILE_PRIVATE(_MEMSWAP
, RES_FAILCNT
),
5856 .write
= mem_cgroup_reset
,
5857 .read_u64
= mem_cgroup_read_u64
,
5859 { }, /* terminate */
5862 static int __init
mem_cgroup_swap_init(void)
5864 if (!mem_cgroup_disabled() && really_do_swap_account
) {
5865 do_swap_account
= 1;
5866 WARN_ON(cgroup_add_legacy_cftypes(&memory_cgrp_subsys
,
5867 memsw_cgroup_files
));
5871 subsys_initcall(mem_cgroup_swap_init
);
5873 #endif /* CONFIG_MEMCG_SWAP */