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 #ifdef CONFIG_MEMCG_SWAP
76 /* Turned on only when memory cgroup is enabled && really_do_swap_account = 1 */
77 int do_swap_account __read_mostly
;
79 /* for remember boot option*/
80 #ifdef CONFIG_MEMCG_SWAP_ENABLED
81 static int really_do_swap_account __initdata
= 1;
83 static int really_do_swap_account __initdata
;
87 #define do_swap_account 0
91 static const char * const mem_cgroup_stat_names
[] = {
100 enum mem_cgroup_events_index
{
101 MEM_CGROUP_EVENTS_PGPGIN
, /* # of pages paged in */
102 MEM_CGROUP_EVENTS_PGPGOUT
, /* # of pages paged out */
103 MEM_CGROUP_EVENTS_PGFAULT
, /* # of page-faults */
104 MEM_CGROUP_EVENTS_PGMAJFAULT
, /* # of major page-faults */
105 MEM_CGROUP_EVENTS_NSTATS
,
108 static const char * const mem_cgroup_events_names
[] = {
115 static const char * const mem_cgroup_lru_names
[] = {
124 * Per memcg event counter is incremented at every pagein/pageout. With THP,
125 * it will be incremated by the number of pages. This counter is used for
126 * for trigger some periodic events. This is straightforward and better
127 * than using jiffies etc. to handle periodic memcg event.
129 enum mem_cgroup_events_target
{
130 MEM_CGROUP_TARGET_THRESH
,
131 MEM_CGROUP_TARGET_SOFTLIMIT
,
132 MEM_CGROUP_TARGET_NUMAINFO
,
135 #define THRESHOLDS_EVENTS_TARGET 128
136 #define SOFTLIMIT_EVENTS_TARGET 1024
137 #define NUMAINFO_EVENTS_TARGET 1024
139 struct mem_cgroup_stat_cpu
{
140 long count
[MEM_CGROUP_STAT_NSTATS
];
141 unsigned long events
[MEM_CGROUP_EVENTS_NSTATS
];
142 unsigned long nr_page_events
;
143 unsigned long targets
[MEM_CGROUP_NTARGETS
];
146 struct reclaim_iter
{
147 struct mem_cgroup
*position
;
148 /* scan generation, increased every round-trip */
149 unsigned int generation
;
153 * per-zone information in memory controller.
155 struct mem_cgroup_per_zone
{
156 struct lruvec lruvec
;
157 unsigned long lru_size
[NR_LRU_LISTS
];
159 struct reclaim_iter iter
[DEF_PRIORITY
+ 1];
161 struct rb_node tree_node
; /* RB tree node */
162 unsigned long usage_in_excess
;/* Set to the value by which */
163 /* the soft limit is exceeded*/
165 struct mem_cgroup
*memcg
; /* Back pointer, we cannot */
166 /* use container_of */
169 struct mem_cgroup_per_node
{
170 struct mem_cgroup_per_zone zoneinfo
[MAX_NR_ZONES
];
174 * Cgroups above their limits are maintained in a RB-Tree, independent of
175 * their hierarchy representation
178 struct mem_cgroup_tree_per_zone
{
179 struct rb_root rb_root
;
183 struct mem_cgroup_tree_per_node
{
184 struct mem_cgroup_tree_per_zone rb_tree_per_zone
[MAX_NR_ZONES
];
187 struct mem_cgroup_tree
{
188 struct mem_cgroup_tree_per_node
*rb_tree_per_node
[MAX_NUMNODES
];
191 static struct mem_cgroup_tree soft_limit_tree __read_mostly
;
193 struct mem_cgroup_threshold
{
194 struct eventfd_ctx
*eventfd
;
195 unsigned long threshold
;
199 struct mem_cgroup_threshold_ary
{
200 /* An array index points to threshold just below or equal to usage. */
201 int current_threshold
;
202 /* Size of entries[] */
204 /* Array of thresholds */
205 struct mem_cgroup_threshold entries
[0];
208 struct mem_cgroup_thresholds
{
209 /* Primary thresholds array */
210 struct mem_cgroup_threshold_ary
*primary
;
212 * Spare threshold array.
213 * This is needed to make mem_cgroup_unregister_event() "never fail".
214 * It must be able to store at least primary->size - 1 entries.
216 struct mem_cgroup_threshold_ary
*spare
;
220 struct mem_cgroup_eventfd_list
{
221 struct list_head list
;
222 struct eventfd_ctx
*eventfd
;
226 * cgroup_event represents events which userspace want to receive.
228 struct mem_cgroup_event
{
230 * memcg which the event belongs to.
232 struct mem_cgroup
*memcg
;
234 * eventfd to signal userspace about the event.
236 struct eventfd_ctx
*eventfd
;
238 * Each of these stored in a list by the cgroup.
240 struct list_head list
;
242 * register_event() callback will be used to add new userspace
243 * waiter for changes related to this event. Use eventfd_signal()
244 * on eventfd to send notification to userspace.
246 int (*register_event
)(struct mem_cgroup
*memcg
,
247 struct eventfd_ctx
*eventfd
, const char *args
);
249 * unregister_event() callback will be called when userspace closes
250 * the eventfd or on cgroup removing. This callback must be set,
251 * if you want provide notification functionality.
253 void (*unregister_event
)(struct mem_cgroup
*memcg
,
254 struct eventfd_ctx
*eventfd
);
256 * All fields below needed to unregister event when
257 * userspace closes eventfd.
260 wait_queue_head_t
*wqh
;
262 struct work_struct remove
;
265 static void mem_cgroup_threshold(struct mem_cgroup
*memcg
);
266 static void mem_cgroup_oom_notify(struct mem_cgroup
*memcg
);
269 * The memory controller data structure. The memory controller controls both
270 * page cache and RSS per cgroup. We would eventually like to provide
271 * statistics based on the statistics developed by Rik Van Riel for clock-pro,
272 * to help the administrator determine what knobs to tune.
274 * TODO: Add a water mark for the memory controller. Reclaim will begin when
275 * we hit the water mark. May be even add a low water mark, such that
276 * no reclaim occurs from a cgroup at it's low water mark, this is
277 * a feature that will be implemented much later in the future.
280 struct cgroup_subsys_state css
;
282 /* Accounted resources */
283 struct page_counter memory
;
284 struct page_counter memsw
;
285 struct page_counter kmem
;
287 unsigned long soft_limit
;
289 /* vmpressure notifications */
290 struct vmpressure vmpressure
;
292 /* css_online() has been completed */
296 * Should the accounting and control be hierarchical, per subtree?
302 atomic_t oom_wakeups
;
305 /* OOM-Killer disable */
306 int oom_kill_disable
;
308 /* protect arrays of thresholds */
309 struct mutex thresholds_lock
;
311 /* thresholds for memory usage. RCU-protected */
312 struct mem_cgroup_thresholds thresholds
;
314 /* thresholds for mem+swap usage. RCU-protected */
315 struct mem_cgroup_thresholds memsw_thresholds
;
317 /* For oom notifier event fd */
318 struct list_head oom_notify
;
321 * Should we move charges of a task when a task is moved into this
322 * mem_cgroup ? And what type of charges should we move ?
324 unsigned long move_charge_at_immigrate
;
326 * set > 0 if pages under this cgroup are moving to other cgroup.
328 atomic_t moving_account
;
329 /* taken only while moving_account > 0 */
330 spinlock_t move_lock
;
334 struct mem_cgroup_stat_cpu __percpu
*stat
;
336 * used when a cpu is offlined or other synchronizations
337 * See mem_cgroup_read_stat().
339 struct mem_cgroup_stat_cpu nocpu_base
;
340 spinlock_t pcp_counter_lock
;
342 #if defined(CONFIG_MEMCG_KMEM) && defined(CONFIG_INET)
343 struct cg_proto tcp_mem
;
345 #if defined(CONFIG_MEMCG_KMEM)
346 /* Index in the kmem_cache->memcg_params->memcg_caches array */
350 int last_scanned_node
;
352 nodemask_t scan_nodes
;
353 atomic_t numainfo_events
;
354 atomic_t numainfo_updating
;
357 /* List of events which userspace want to receive */
358 struct list_head event_list
;
359 spinlock_t event_list_lock
;
361 struct mem_cgroup_per_node
*nodeinfo
[0];
362 /* WARNING: nodeinfo must be the last member here */
365 #ifdef CONFIG_MEMCG_KMEM
366 static bool memcg_kmem_is_active(struct mem_cgroup
*memcg
)
368 return memcg
->kmemcg_id
>= 0;
372 /* Stuffs for move charges at task migration. */
374 * Types of charges to be moved. "move_charge_at_immitgrate" and
375 * "immigrate_flags" are treated as a left-shifted bitmap of these types.
378 MOVE_CHARGE_TYPE_ANON
, /* private anonymous page and swap of it */
379 MOVE_CHARGE_TYPE_FILE
, /* file page(including tmpfs) and swap of it */
383 /* "mc" and its members are protected by cgroup_mutex */
384 static struct move_charge_struct
{
385 spinlock_t lock
; /* for from, to */
386 struct mem_cgroup
*from
;
387 struct mem_cgroup
*to
;
388 unsigned long immigrate_flags
;
389 unsigned long precharge
;
390 unsigned long moved_charge
;
391 unsigned long moved_swap
;
392 struct task_struct
*moving_task
; /* a task moving charges */
393 wait_queue_head_t waitq
; /* a waitq for other context */
395 .lock
= __SPIN_LOCK_UNLOCKED(mc
.lock
),
396 .waitq
= __WAIT_QUEUE_HEAD_INITIALIZER(mc
.waitq
),
399 static bool move_anon(void)
401 return test_bit(MOVE_CHARGE_TYPE_ANON
, &mc
.immigrate_flags
);
404 static bool move_file(void)
406 return test_bit(MOVE_CHARGE_TYPE_FILE
, &mc
.immigrate_flags
);
410 * Maximum loops in mem_cgroup_hierarchical_reclaim(), used for soft
411 * limit reclaim to prevent infinite loops, if they ever occur.
413 #define MEM_CGROUP_MAX_RECLAIM_LOOPS 100
414 #define MEM_CGROUP_MAX_SOFT_LIMIT_RECLAIM_LOOPS 2
417 MEM_CGROUP_CHARGE_TYPE_CACHE
= 0,
418 MEM_CGROUP_CHARGE_TYPE_ANON
,
419 MEM_CGROUP_CHARGE_TYPE_SWAPOUT
, /* for accounting swapcache */
420 MEM_CGROUP_CHARGE_TYPE_DROP
, /* a page was unused swap cache */
424 /* for encoding cft->private value on file */
432 #define MEMFILE_PRIVATE(x, val) ((x) << 16 | (val))
433 #define MEMFILE_TYPE(val) ((val) >> 16 & 0xffff)
434 #define MEMFILE_ATTR(val) ((val) & 0xffff)
435 /* Used for OOM nofiier */
436 #define OOM_CONTROL (0)
439 * The memcg_create_mutex will be held whenever a new cgroup is created.
440 * As a consequence, any change that needs to protect against new child cgroups
441 * appearing has to hold it as well.
443 static DEFINE_MUTEX(memcg_create_mutex
);
445 struct mem_cgroup
*mem_cgroup_from_css(struct cgroup_subsys_state
*s
)
447 return s
? container_of(s
, struct mem_cgroup
, css
) : NULL
;
450 /* Some nice accessors for the vmpressure. */
451 struct vmpressure
*memcg_to_vmpressure(struct mem_cgroup
*memcg
)
454 memcg
= root_mem_cgroup
;
455 return &memcg
->vmpressure
;
458 struct cgroup_subsys_state
*vmpressure_to_css(struct vmpressure
*vmpr
)
460 return &container_of(vmpr
, struct mem_cgroup
, vmpressure
)->css
;
463 static inline bool mem_cgroup_is_root(struct mem_cgroup
*memcg
)
465 return (memcg
== root_mem_cgroup
);
469 * We restrict the id in the range of [1, 65535], so it can fit into
472 #define MEM_CGROUP_ID_MAX USHRT_MAX
474 static inline unsigned short mem_cgroup_id(struct mem_cgroup
*memcg
)
476 return memcg
->css
.id
;
479 static inline struct mem_cgroup
*mem_cgroup_from_id(unsigned short id
)
481 struct cgroup_subsys_state
*css
;
483 css
= css_from_id(id
, &memory_cgrp_subsys
);
484 return mem_cgroup_from_css(css
);
487 /* Writing them here to avoid exposing memcg's inner layout */
488 #if defined(CONFIG_INET) && defined(CONFIG_MEMCG_KMEM)
490 void sock_update_memcg(struct sock
*sk
)
492 if (mem_cgroup_sockets_enabled
) {
493 struct mem_cgroup
*memcg
;
494 struct cg_proto
*cg_proto
;
496 BUG_ON(!sk
->sk_prot
->proto_cgroup
);
498 /* Socket cloning can throw us here with sk_cgrp already
499 * filled. It won't however, necessarily happen from
500 * process context. So the test for root memcg given
501 * the current task's memcg won't help us in this case.
503 * Respecting the original socket's memcg is a better
504 * decision in this case.
507 BUG_ON(mem_cgroup_is_root(sk
->sk_cgrp
->memcg
));
508 css_get(&sk
->sk_cgrp
->memcg
->css
);
513 memcg
= mem_cgroup_from_task(current
);
514 cg_proto
= sk
->sk_prot
->proto_cgroup(memcg
);
515 if (!mem_cgroup_is_root(memcg
) &&
516 memcg_proto_active(cg_proto
) &&
517 css_tryget_online(&memcg
->css
)) {
518 sk
->sk_cgrp
= cg_proto
;
523 EXPORT_SYMBOL(sock_update_memcg
);
525 void sock_release_memcg(struct sock
*sk
)
527 if (mem_cgroup_sockets_enabled
&& sk
->sk_cgrp
) {
528 struct mem_cgroup
*memcg
;
529 WARN_ON(!sk
->sk_cgrp
->memcg
);
530 memcg
= sk
->sk_cgrp
->memcg
;
531 css_put(&sk
->sk_cgrp
->memcg
->css
);
535 struct cg_proto
*tcp_proto_cgroup(struct mem_cgroup
*memcg
)
537 if (!memcg
|| mem_cgroup_is_root(memcg
))
540 return &memcg
->tcp_mem
;
542 EXPORT_SYMBOL(tcp_proto_cgroup
);
544 static void disarm_sock_keys(struct mem_cgroup
*memcg
)
546 if (!memcg_proto_activated(&memcg
->tcp_mem
))
548 static_key_slow_dec(&memcg_socket_limit_enabled
);
551 static void disarm_sock_keys(struct mem_cgroup
*memcg
)
556 #ifdef CONFIG_MEMCG_KMEM
558 * This will be the memcg's index in each cache's ->memcg_params->memcg_caches.
559 * The main reason for not using cgroup id for this:
560 * this works better in sparse environments, where we have a lot of memcgs,
561 * but only a few kmem-limited. Or also, if we have, for instance, 200
562 * memcgs, and none but the 200th is kmem-limited, we'd have to have a
563 * 200 entry array for that.
565 * The current size of the caches array is stored in
566 * memcg_limited_groups_array_size. It will double each time we have to
569 static DEFINE_IDA(kmem_limited_groups
);
570 int memcg_limited_groups_array_size
;
573 * MIN_SIZE is different than 1, because we would like to avoid going through
574 * the alloc/free process all the time. In a small machine, 4 kmem-limited
575 * cgroups is a reasonable guess. In the future, it could be a parameter or
576 * tunable, but that is strictly not necessary.
578 * MAX_SIZE should be as large as the number of cgrp_ids. Ideally, we could get
579 * this constant directly from cgroup, but it is understandable that this is
580 * better kept as an internal representation in cgroup.c. In any case, the
581 * cgrp_id space is not getting any smaller, and we don't have to necessarily
582 * increase ours as well if it increases.
584 #define MEMCG_CACHES_MIN_SIZE 4
585 #define MEMCG_CACHES_MAX_SIZE MEM_CGROUP_ID_MAX
588 * A lot of the calls to the cache allocation functions are expected to be
589 * inlined by the compiler. Since the calls to memcg_kmem_get_cache are
590 * conditional to this static branch, we'll have to allow modules that does
591 * kmem_cache_alloc and the such to see this symbol as well
593 struct static_key memcg_kmem_enabled_key
;
594 EXPORT_SYMBOL(memcg_kmem_enabled_key
);
596 static void memcg_free_cache_id(int id
);
598 static void disarm_kmem_keys(struct mem_cgroup
*memcg
)
600 if (memcg_kmem_is_active(memcg
)) {
601 static_key_slow_dec(&memcg_kmem_enabled_key
);
602 memcg_free_cache_id(memcg
->kmemcg_id
);
605 * This check can't live in kmem destruction function,
606 * since the charges will outlive the cgroup
608 WARN_ON(page_counter_read(&memcg
->kmem
));
611 static void disarm_kmem_keys(struct mem_cgroup
*memcg
)
614 #endif /* CONFIG_MEMCG_KMEM */
616 static void disarm_static_keys(struct mem_cgroup
*memcg
)
618 disarm_sock_keys(memcg
);
619 disarm_kmem_keys(memcg
);
622 static struct mem_cgroup_per_zone
*
623 mem_cgroup_zone_zoneinfo(struct mem_cgroup
*memcg
, struct zone
*zone
)
625 int nid
= zone_to_nid(zone
);
626 int zid
= zone_idx(zone
);
628 return &memcg
->nodeinfo
[nid
]->zoneinfo
[zid
];
631 struct cgroup_subsys_state
*mem_cgroup_css(struct mem_cgroup
*memcg
)
636 static struct mem_cgroup_per_zone
*
637 mem_cgroup_page_zoneinfo(struct mem_cgroup
*memcg
, struct page
*page
)
639 int nid
= page_to_nid(page
);
640 int zid
= page_zonenum(page
);
642 return &memcg
->nodeinfo
[nid
]->zoneinfo
[zid
];
645 static struct mem_cgroup_tree_per_zone
*
646 soft_limit_tree_node_zone(int nid
, int zid
)
648 return &soft_limit_tree
.rb_tree_per_node
[nid
]->rb_tree_per_zone
[zid
];
651 static struct mem_cgroup_tree_per_zone
*
652 soft_limit_tree_from_page(struct page
*page
)
654 int nid
= page_to_nid(page
);
655 int zid
= page_zonenum(page
);
657 return &soft_limit_tree
.rb_tree_per_node
[nid
]->rb_tree_per_zone
[zid
];
660 static void __mem_cgroup_insert_exceeded(struct mem_cgroup_per_zone
*mz
,
661 struct mem_cgroup_tree_per_zone
*mctz
,
662 unsigned long new_usage_in_excess
)
664 struct rb_node
**p
= &mctz
->rb_root
.rb_node
;
665 struct rb_node
*parent
= NULL
;
666 struct mem_cgroup_per_zone
*mz_node
;
671 mz
->usage_in_excess
= new_usage_in_excess
;
672 if (!mz
->usage_in_excess
)
676 mz_node
= rb_entry(parent
, struct mem_cgroup_per_zone
,
678 if (mz
->usage_in_excess
< mz_node
->usage_in_excess
)
681 * We can't avoid mem cgroups that are over their soft
682 * limit by the same amount
684 else if (mz
->usage_in_excess
>= mz_node
->usage_in_excess
)
687 rb_link_node(&mz
->tree_node
, parent
, p
);
688 rb_insert_color(&mz
->tree_node
, &mctz
->rb_root
);
692 static void __mem_cgroup_remove_exceeded(struct mem_cgroup_per_zone
*mz
,
693 struct mem_cgroup_tree_per_zone
*mctz
)
697 rb_erase(&mz
->tree_node
, &mctz
->rb_root
);
701 static void mem_cgroup_remove_exceeded(struct mem_cgroup_per_zone
*mz
,
702 struct mem_cgroup_tree_per_zone
*mctz
)
706 spin_lock_irqsave(&mctz
->lock
, flags
);
707 __mem_cgroup_remove_exceeded(mz
, mctz
);
708 spin_unlock_irqrestore(&mctz
->lock
, flags
);
711 static unsigned long soft_limit_excess(struct mem_cgroup
*memcg
)
713 unsigned long nr_pages
= page_counter_read(&memcg
->memory
);
714 unsigned long soft_limit
= ACCESS_ONCE(memcg
->soft_limit
);
715 unsigned long excess
= 0;
717 if (nr_pages
> soft_limit
)
718 excess
= nr_pages
- soft_limit
;
723 static void mem_cgroup_update_tree(struct mem_cgroup
*memcg
, struct page
*page
)
725 unsigned long excess
;
726 struct mem_cgroup_per_zone
*mz
;
727 struct mem_cgroup_tree_per_zone
*mctz
;
729 mctz
= soft_limit_tree_from_page(page
);
731 * Necessary to update all ancestors when hierarchy is used.
732 * because their event counter is not touched.
734 for (; memcg
; memcg
= parent_mem_cgroup(memcg
)) {
735 mz
= mem_cgroup_page_zoneinfo(memcg
, page
);
736 excess
= soft_limit_excess(memcg
);
738 * We have to update the tree if mz is on RB-tree or
739 * mem is over its softlimit.
741 if (excess
|| mz
->on_tree
) {
744 spin_lock_irqsave(&mctz
->lock
, flags
);
745 /* if on-tree, remove it */
747 __mem_cgroup_remove_exceeded(mz
, mctz
);
749 * Insert again. mz->usage_in_excess will be updated.
750 * If excess is 0, no tree ops.
752 __mem_cgroup_insert_exceeded(mz
, mctz
, excess
);
753 spin_unlock_irqrestore(&mctz
->lock
, flags
);
758 static void mem_cgroup_remove_from_trees(struct mem_cgroup
*memcg
)
760 struct mem_cgroup_tree_per_zone
*mctz
;
761 struct mem_cgroup_per_zone
*mz
;
765 for (zid
= 0; zid
< MAX_NR_ZONES
; zid
++) {
766 mz
= &memcg
->nodeinfo
[nid
]->zoneinfo
[zid
];
767 mctz
= soft_limit_tree_node_zone(nid
, zid
);
768 mem_cgroup_remove_exceeded(mz
, mctz
);
773 static struct mem_cgroup_per_zone
*
774 __mem_cgroup_largest_soft_limit_node(struct mem_cgroup_tree_per_zone
*mctz
)
776 struct rb_node
*rightmost
= NULL
;
777 struct mem_cgroup_per_zone
*mz
;
781 rightmost
= rb_last(&mctz
->rb_root
);
783 goto done
; /* Nothing to reclaim from */
785 mz
= rb_entry(rightmost
, struct mem_cgroup_per_zone
, tree_node
);
787 * Remove the node now but someone else can add it back,
788 * we will to add it back at the end of reclaim to its correct
789 * position in the tree.
791 __mem_cgroup_remove_exceeded(mz
, mctz
);
792 if (!soft_limit_excess(mz
->memcg
) ||
793 !css_tryget_online(&mz
->memcg
->css
))
799 static struct mem_cgroup_per_zone
*
800 mem_cgroup_largest_soft_limit_node(struct mem_cgroup_tree_per_zone
*mctz
)
802 struct mem_cgroup_per_zone
*mz
;
804 spin_lock_irq(&mctz
->lock
);
805 mz
= __mem_cgroup_largest_soft_limit_node(mctz
);
806 spin_unlock_irq(&mctz
->lock
);
811 * Implementation Note: reading percpu statistics for memcg.
813 * Both of vmstat[] and percpu_counter has threshold and do periodic
814 * synchronization to implement "quick" read. There are trade-off between
815 * reading cost and precision of value. Then, we may have a chance to implement
816 * a periodic synchronizion of counter in memcg's counter.
818 * But this _read() function is used for user interface now. The user accounts
819 * memory usage by memory cgroup and he _always_ requires exact value because
820 * he accounts memory. Even if we provide quick-and-fuzzy read, we always
821 * have to visit all online cpus and make sum. So, for now, unnecessary
822 * synchronization is not implemented. (just implemented for cpu hotplug)
824 * If there are kernel internal actions which can make use of some not-exact
825 * value, and reading all cpu value can be performance bottleneck in some
826 * common workload, threashold and synchonization as vmstat[] should be
829 static long mem_cgroup_read_stat(struct mem_cgroup
*memcg
,
830 enum mem_cgroup_stat_index idx
)
836 for_each_online_cpu(cpu
)
837 val
+= per_cpu(memcg
->stat
->count
[idx
], cpu
);
838 #ifdef CONFIG_HOTPLUG_CPU
839 spin_lock(&memcg
->pcp_counter_lock
);
840 val
+= memcg
->nocpu_base
.count
[idx
];
841 spin_unlock(&memcg
->pcp_counter_lock
);
847 static unsigned long mem_cgroup_read_events(struct mem_cgroup
*memcg
,
848 enum mem_cgroup_events_index idx
)
850 unsigned long val
= 0;
854 for_each_online_cpu(cpu
)
855 val
+= per_cpu(memcg
->stat
->events
[idx
], cpu
);
856 #ifdef CONFIG_HOTPLUG_CPU
857 spin_lock(&memcg
->pcp_counter_lock
);
858 val
+= memcg
->nocpu_base
.events
[idx
];
859 spin_unlock(&memcg
->pcp_counter_lock
);
865 static void mem_cgroup_charge_statistics(struct mem_cgroup
*memcg
,
870 * Here, RSS means 'mapped anon' and anon's SwapCache. Shmem/tmpfs is
871 * counted as CACHE even if it's on ANON LRU.
874 __this_cpu_add(memcg
->stat
->count
[MEM_CGROUP_STAT_RSS
],
877 __this_cpu_add(memcg
->stat
->count
[MEM_CGROUP_STAT_CACHE
],
880 if (PageTransHuge(page
))
881 __this_cpu_add(memcg
->stat
->count
[MEM_CGROUP_STAT_RSS_HUGE
],
884 /* pagein of a big page is an event. So, ignore page size */
886 __this_cpu_inc(memcg
->stat
->events
[MEM_CGROUP_EVENTS_PGPGIN
]);
888 __this_cpu_inc(memcg
->stat
->events
[MEM_CGROUP_EVENTS_PGPGOUT
]);
889 nr_pages
= -nr_pages
; /* for event */
892 __this_cpu_add(memcg
->stat
->nr_page_events
, nr_pages
);
895 unsigned long mem_cgroup_get_lru_size(struct lruvec
*lruvec
, enum lru_list lru
)
897 struct mem_cgroup_per_zone
*mz
;
899 mz
= container_of(lruvec
, struct mem_cgroup_per_zone
, lruvec
);
900 return mz
->lru_size
[lru
];
903 static unsigned long mem_cgroup_node_nr_lru_pages(struct mem_cgroup
*memcg
,
905 unsigned int lru_mask
)
907 unsigned long nr
= 0;
910 VM_BUG_ON((unsigned)nid
>= nr_node_ids
);
912 for (zid
= 0; zid
< MAX_NR_ZONES
; zid
++) {
913 struct mem_cgroup_per_zone
*mz
;
917 if (!(BIT(lru
) & lru_mask
))
919 mz
= &memcg
->nodeinfo
[nid
]->zoneinfo
[zid
];
920 nr
+= mz
->lru_size
[lru
];
926 static unsigned long mem_cgroup_nr_lru_pages(struct mem_cgroup
*memcg
,
927 unsigned int lru_mask
)
929 unsigned long nr
= 0;
932 for_each_node_state(nid
, N_MEMORY
)
933 nr
+= mem_cgroup_node_nr_lru_pages(memcg
, nid
, lru_mask
);
937 static bool mem_cgroup_event_ratelimit(struct mem_cgroup
*memcg
,
938 enum mem_cgroup_events_target target
)
940 unsigned long val
, next
;
942 val
= __this_cpu_read(memcg
->stat
->nr_page_events
);
943 next
= __this_cpu_read(memcg
->stat
->targets
[target
]);
944 /* from time_after() in jiffies.h */
945 if ((long)next
- (long)val
< 0) {
947 case MEM_CGROUP_TARGET_THRESH
:
948 next
= val
+ THRESHOLDS_EVENTS_TARGET
;
950 case MEM_CGROUP_TARGET_SOFTLIMIT
:
951 next
= val
+ SOFTLIMIT_EVENTS_TARGET
;
953 case MEM_CGROUP_TARGET_NUMAINFO
:
954 next
= val
+ NUMAINFO_EVENTS_TARGET
;
959 __this_cpu_write(memcg
->stat
->targets
[target
], next
);
966 * Check events in order.
969 static void memcg_check_events(struct mem_cgroup
*memcg
, struct page
*page
)
971 /* threshold event is triggered in finer grain than soft limit */
972 if (unlikely(mem_cgroup_event_ratelimit(memcg
,
973 MEM_CGROUP_TARGET_THRESH
))) {
975 bool do_numainfo __maybe_unused
;
977 do_softlimit
= mem_cgroup_event_ratelimit(memcg
,
978 MEM_CGROUP_TARGET_SOFTLIMIT
);
980 do_numainfo
= mem_cgroup_event_ratelimit(memcg
,
981 MEM_CGROUP_TARGET_NUMAINFO
);
983 mem_cgroup_threshold(memcg
);
984 if (unlikely(do_softlimit
))
985 mem_cgroup_update_tree(memcg
, page
);
987 if (unlikely(do_numainfo
))
988 atomic_inc(&memcg
->numainfo_events
);
993 struct mem_cgroup
*mem_cgroup_from_task(struct task_struct
*p
)
996 * mm_update_next_owner() may clear mm->owner to NULL
997 * if it races with swapoff, page migration, etc.
998 * So this can be called with p == NULL.
1003 return mem_cgroup_from_css(task_css(p
, memory_cgrp_id
));
1006 static struct mem_cgroup
*get_mem_cgroup_from_mm(struct mm_struct
*mm
)
1008 struct mem_cgroup
*memcg
= NULL
;
1013 * Page cache insertions can happen withou an
1014 * actual mm context, e.g. during disk probing
1015 * on boot, loopback IO, acct() writes etc.
1018 memcg
= root_mem_cgroup
;
1020 memcg
= mem_cgroup_from_task(rcu_dereference(mm
->owner
));
1021 if (unlikely(!memcg
))
1022 memcg
= root_mem_cgroup
;
1024 } while (!css_tryget_online(&memcg
->css
));
1030 * mem_cgroup_iter - iterate over memory cgroup hierarchy
1031 * @root: hierarchy root
1032 * @prev: previously returned memcg, NULL on first invocation
1033 * @reclaim: cookie for shared reclaim walks, NULL for full walks
1035 * Returns references to children of the hierarchy below @root, or
1036 * @root itself, or %NULL after a full round-trip.
1038 * Caller must pass the return value in @prev on subsequent
1039 * invocations for reference counting, or use mem_cgroup_iter_break()
1040 * to cancel a hierarchy walk before the round-trip is complete.
1042 * Reclaimers can specify a zone and a priority level in @reclaim to
1043 * divide up the memcgs in the hierarchy among all concurrent
1044 * reclaimers operating on the same zone and priority.
1046 struct mem_cgroup
*mem_cgroup_iter(struct mem_cgroup
*root
,
1047 struct mem_cgroup
*prev
,
1048 struct mem_cgroup_reclaim_cookie
*reclaim
)
1050 struct reclaim_iter
*uninitialized_var(iter
);
1051 struct cgroup_subsys_state
*css
= NULL
;
1052 struct mem_cgroup
*memcg
= NULL
;
1053 struct mem_cgroup
*pos
= NULL
;
1055 if (mem_cgroup_disabled())
1059 root
= root_mem_cgroup
;
1061 if (prev
&& !reclaim
)
1064 if (!root
->use_hierarchy
&& root
!= root_mem_cgroup
) {
1073 struct mem_cgroup_per_zone
*mz
;
1075 mz
= mem_cgroup_zone_zoneinfo(root
, reclaim
->zone
);
1076 iter
= &mz
->iter
[reclaim
->priority
];
1078 if (prev
&& reclaim
->generation
!= iter
->generation
)
1082 pos
= ACCESS_ONCE(iter
->position
);
1084 * A racing update may change the position and
1085 * put the last reference, hence css_tryget(),
1086 * or retry to see the updated position.
1088 } while (pos
&& !css_tryget(&pos
->css
));
1095 css
= css_next_descendant_pre(css
, &root
->css
);
1098 * Reclaimers share the hierarchy walk, and a
1099 * new one might jump in right at the end of
1100 * the hierarchy - make sure they see at least
1101 * one group and restart from the beginning.
1109 * Verify the css and acquire a reference. The root
1110 * is provided by the caller, so we know it's alive
1111 * and kicking, and don't take an extra reference.
1113 memcg
= mem_cgroup_from_css(css
);
1115 if (css
== &root
->css
)
1118 if (css_tryget(css
)) {
1120 * Make sure the memcg is initialized:
1121 * mem_cgroup_css_online() orders the the
1122 * initialization against setting the flag.
1124 if (smp_load_acquire(&memcg
->initialized
))
1134 if (cmpxchg(&iter
->position
, pos
, memcg
) == pos
) {
1136 css_get(&memcg
->css
);
1142 * pairs with css_tryget when dereferencing iter->position
1151 reclaim
->generation
= iter
->generation
;
1157 if (prev
&& prev
!= root
)
1158 css_put(&prev
->css
);
1164 * mem_cgroup_iter_break - abort a hierarchy walk prematurely
1165 * @root: hierarchy root
1166 * @prev: last visited hierarchy member as returned by mem_cgroup_iter()
1168 void mem_cgroup_iter_break(struct mem_cgroup
*root
,
1169 struct mem_cgroup
*prev
)
1172 root
= root_mem_cgroup
;
1173 if (prev
&& prev
!= root
)
1174 css_put(&prev
->css
);
1178 * Iteration constructs for visiting all cgroups (under a tree). If
1179 * loops are exited prematurely (break), mem_cgroup_iter_break() must
1180 * be used for reference counting.
1182 #define for_each_mem_cgroup_tree(iter, root) \
1183 for (iter = mem_cgroup_iter(root, NULL, NULL); \
1185 iter = mem_cgroup_iter(root, iter, NULL))
1187 #define for_each_mem_cgroup(iter) \
1188 for (iter = mem_cgroup_iter(NULL, NULL, NULL); \
1190 iter = mem_cgroup_iter(NULL, iter, NULL))
1192 void __mem_cgroup_count_vm_event(struct mm_struct
*mm
, enum vm_event_item idx
)
1194 struct mem_cgroup
*memcg
;
1197 memcg
= mem_cgroup_from_task(rcu_dereference(mm
->owner
));
1198 if (unlikely(!memcg
))
1203 this_cpu_inc(memcg
->stat
->events
[MEM_CGROUP_EVENTS_PGFAULT
]);
1206 this_cpu_inc(memcg
->stat
->events
[MEM_CGROUP_EVENTS_PGMAJFAULT
]);
1214 EXPORT_SYMBOL(__mem_cgroup_count_vm_event
);
1217 * mem_cgroup_zone_lruvec - get the lru list vector for a zone and memcg
1218 * @zone: zone of the wanted lruvec
1219 * @memcg: memcg of the wanted lruvec
1221 * Returns the lru list vector holding pages for the given @zone and
1222 * @mem. This can be the global zone lruvec, if the memory controller
1225 struct lruvec
*mem_cgroup_zone_lruvec(struct zone
*zone
,
1226 struct mem_cgroup
*memcg
)
1228 struct mem_cgroup_per_zone
*mz
;
1229 struct lruvec
*lruvec
;
1231 if (mem_cgroup_disabled()) {
1232 lruvec
= &zone
->lruvec
;
1236 mz
= mem_cgroup_zone_zoneinfo(memcg
, zone
);
1237 lruvec
= &mz
->lruvec
;
1240 * Since a node can be onlined after the mem_cgroup was created,
1241 * we have to be prepared to initialize lruvec->zone here;
1242 * and if offlined then reonlined, we need to reinitialize it.
1244 if (unlikely(lruvec
->zone
!= zone
))
1245 lruvec
->zone
= zone
;
1250 * mem_cgroup_page_lruvec - return lruvec for isolating/putting an LRU page
1252 * @zone: zone of the page
1254 * This function is only safe when following the LRU page isolation
1255 * and putback protocol: the LRU lock must be held, and the page must
1256 * either be PageLRU() or the caller must have isolated/allocated it.
1258 struct lruvec
*mem_cgroup_page_lruvec(struct page
*page
, struct zone
*zone
)
1260 struct mem_cgroup_per_zone
*mz
;
1261 struct mem_cgroup
*memcg
;
1262 struct lruvec
*lruvec
;
1264 if (mem_cgroup_disabled()) {
1265 lruvec
= &zone
->lruvec
;
1269 memcg
= page
->mem_cgroup
;
1271 * Swapcache readahead pages are added to the LRU - and
1272 * possibly migrated - before they are charged.
1275 memcg
= root_mem_cgroup
;
1277 mz
= mem_cgroup_page_zoneinfo(memcg
, page
);
1278 lruvec
= &mz
->lruvec
;
1281 * Since a node can be onlined after the mem_cgroup was created,
1282 * we have to be prepared to initialize lruvec->zone here;
1283 * and if offlined then reonlined, we need to reinitialize it.
1285 if (unlikely(lruvec
->zone
!= zone
))
1286 lruvec
->zone
= zone
;
1291 * mem_cgroup_update_lru_size - account for adding or removing an lru page
1292 * @lruvec: mem_cgroup per zone lru vector
1293 * @lru: index of lru list the page is sitting on
1294 * @nr_pages: positive when adding or negative when removing
1296 * This function must be called when a page is added to or removed from an
1299 void mem_cgroup_update_lru_size(struct lruvec
*lruvec
, enum lru_list lru
,
1302 struct mem_cgroup_per_zone
*mz
;
1303 unsigned long *lru_size
;
1305 if (mem_cgroup_disabled())
1308 mz
= container_of(lruvec
, struct mem_cgroup_per_zone
, lruvec
);
1309 lru_size
= mz
->lru_size
+ lru
;
1310 *lru_size
+= nr_pages
;
1311 VM_BUG_ON((long)(*lru_size
) < 0);
1314 bool mem_cgroup_is_descendant(struct mem_cgroup
*memcg
, struct mem_cgroup
*root
)
1318 if (!root
->use_hierarchy
)
1320 return cgroup_is_descendant(memcg
->css
.cgroup
, root
->css
.cgroup
);
1323 bool task_in_mem_cgroup(struct task_struct
*task
, struct mem_cgroup
*memcg
)
1325 struct mem_cgroup
*task_memcg
;
1326 struct task_struct
*p
;
1329 p
= find_lock_task_mm(task
);
1331 task_memcg
= get_mem_cgroup_from_mm(p
->mm
);
1335 * All threads may have already detached their mm's, but the oom
1336 * killer still needs to detect if they have already been oom
1337 * killed to prevent needlessly killing additional tasks.
1340 task_memcg
= mem_cgroup_from_task(task
);
1341 css_get(&task_memcg
->css
);
1344 ret
= mem_cgroup_is_descendant(task_memcg
, memcg
);
1345 css_put(&task_memcg
->css
);
1349 int mem_cgroup_inactive_anon_is_low(struct lruvec
*lruvec
)
1351 unsigned long inactive_ratio
;
1352 unsigned long inactive
;
1353 unsigned long active
;
1356 inactive
= mem_cgroup_get_lru_size(lruvec
, LRU_INACTIVE_ANON
);
1357 active
= mem_cgroup_get_lru_size(lruvec
, LRU_ACTIVE_ANON
);
1359 gb
= (inactive
+ active
) >> (30 - PAGE_SHIFT
);
1361 inactive_ratio
= int_sqrt(10 * gb
);
1365 return inactive
* inactive_ratio
< active
;
1368 #define mem_cgroup_from_counter(counter, member) \
1369 container_of(counter, struct mem_cgroup, member)
1372 * mem_cgroup_margin - calculate chargeable space of a memory cgroup
1373 * @memcg: the memory cgroup
1375 * Returns the maximum amount of memory @mem can be charged with, in
1378 static unsigned long mem_cgroup_margin(struct mem_cgroup
*memcg
)
1380 unsigned long margin
= 0;
1381 unsigned long count
;
1382 unsigned long limit
;
1384 count
= page_counter_read(&memcg
->memory
);
1385 limit
= ACCESS_ONCE(memcg
->memory
.limit
);
1387 margin
= limit
- count
;
1389 if (do_swap_account
) {
1390 count
= page_counter_read(&memcg
->memsw
);
1391 limit
= ACCESS_ONCE(memcg
->memsw
.limit
);
1393 margin
= min(margin
, limit
- count
);
1399 int mem_cgroup_swappiness(struct mem_cgroup
*memcg
)
1402 if (mem_cgroup_disabled() || !memcg
->css
.parent
)
1403 return vm_swappiness
;
1405 return memcg
->swappiness
;
1409 * A routine for checking "mem" is under move_account() or not.
1411 * Checking a cgroup is mc.from or mc.to or under hierarchy of
1412 * moving cgroups. This is for waiting at high-memory pressure
1415 static bool mem_cgroup_under_move(struct mem_cgroup
*memcg
)
1417 struct mem_cgroup
*from
;
1418 struct mem_cgroup
*to
;
1421 * Unlike task_move routines, we access mc.to, mc.from not under
1422 * mutual exclusion by cgroup_mutex. Here, we take spinlock instead.
1424 spin_lock(&mc
.lock
);
1430 ret
= mem_cgroup_is_descendant(from
, memcg
) ||
1431 mem_cgroup_is_descendant(to
, memcg
);
1433 spin_unlock(&mc
.lock
);
1437 static bool mem_cgroup_wait_acct_move(struct mem_cgroup
*memcg
)
1439 if (mc
.moving_task
&& current
!= mc
.moving_task
) {
1440 if (mem_cgroup_under_move(memcg
)) {
1442 prepare_to_wait(&mc
.waitq
, &wait
, TASK_INTERRUPTIBLE
);
1443 /* moving charge context might have finished. */
1446 finish_wait(&mc
.waitq
, &wait
);
1453 #define K(x) ((x) << (PAGE_SHIFT-10))
1455 * mem_cgroup_print_oom_info: Print OOM information relevant to memory controller.
1456 * @memcg: The memory cgroup that went over limit
1457 * @p: Task that is going to be killed
1459 * NOTE: @memcg and @p's mem_cgroup can be different when hierarchy is
1462 void mem_cgroup_print_oom_info(struct mem_cgroup
*memcg
, struct task_struct
*p
)
1464 /* oom_info_lock ensures that parallel ooms do not interleave */
1465 static DEFINE_MUTEX(oom_info_lock
);
1466 struct mem_cgroup
*iter
;
1472 mutex_lock(&oom_info_lock
);
1475 pr_info("Task in ");
1476 pr_cont_cgroup_path(task_cgroup(p
, memory_cgrp_id
));
1477 pr_cont(" killed as a result of limit of ");
1478 pr_cont_cgroup_path(memcg
->css
.cgroup
);
1483 pr_info("memory: usage %llukB, limit %llukB, failcnt %lu\n",
1484 K((u64
)page_counter_read(&memcg
->memory
)),
1485 K((u64
)memcg
->memory
.limit
), memcg
->memory
.failcnt
);
1486 pr_info("memory+swap: usage %llukB, limit %llukB, failcnt %lu\n",
1487 K((u64
)page_counter_read(&memcg
->memsw
)),
1488 K((u64
)memcg
->memsw
.limit
), memcg
->memsw
.failcnt
);
1489 pr_info("kmem: usage %llukB, limit %llukB, failcnt %lu\n",
1490 K((u64
)page_counter_read(&memcg
->kmem
)),
1491 K((u64
)memcg
->kmem
.limit
), memcg
->kmem
.failcnt
);
1493 for_each_mem_cgroup_tree(iter
, memcg
) {
1494 pr_info("Memory cgroup stats for ");
1495 pr_cont_cgroup_path(iter
->css
.cgroup
);
1498 for (i
= 0; i
< MEM_CGROUP_STAT_NSTATS
; i
++) {
1499 if (i
== MEM_CGROUP_STAT_SWAP
&& !do_swap_account
)
1501 pr_cont(" %s:%ldKB", mem_cgroup_stat_names
[i
],
1502 K(mem_cgroup_read_stat(iter
, i
)));
1505 for (i
= 0; i
< NR_LRU_LISTS
; i
++)
1506 pr_cont(" %s:%luKB", mem_cgroup_lru_names
[i
],
1507 K(mem_cgroup_nr_lru_pages(iter
, BIT(i
))));
1511 mutex_unlock(&oom_info_lock
);
1515 * This function returns the number of memcg under hierarchy tree. Returns
1516 * 1(self count) if no children.
1518 static int mem_cgroup_count_children(struct mem_cgroup
*memcg
)
1521 struct mem_cgroup
*iter
;
1523 for_each_mem_cgroup_tree(iter
, memcg
)
1529 * Return the memory (and swap, if configured) limit for a memcg.
1531 static unsigned long mem_cgroup_get_limit(struct mem_cgroup
*memcg
)
1533 unsigned long limit
;
1535 limit
= memcg
->memory
.limit
;
1536 if (mem_cgroup_swappiness(memcg
)) {
1537 unsigned long memsw_limit
;
1539 memsw_limit
= memcg
->memsw
.limit
;
1540 limit
= min(limit
+ total_swap_pages
, memsw_limit
);
1545 static void mem_cgroup_out_of_memory(struct mem_cgroup
*memcg
, gfp_t gfp_mask
,
1548 struct mem_cgroup
*iter
;
1549 unsigned long chosen_points
= 0;
1550 unsigned long totalpages
;
1551 unsigned int points
= 0;
1552 struct task_struct
*chosen
= NULL
;
1555 * If current has a pending SIGKILL or is exiting, then automatically
1556 * select it. The goal is to allow it to allocate so that it may
1557 * quickly exit and free its memory.
1559 if (fatal_signal_pending(current
) || task_will_free_mem(current
)) {
1560 set_thread_flag(TIF_MEMDIE
);
1564 check_panic_on_oom(CONSTRAINT_MEMCG
, gfp_mask
, order
, NULL
);
1565 totalpages
= mem_cgroup_get_limit(memcg
) ? : 1;
1566 for_each_mem_cgroup_tree(iter
, memcg
) {
1567 struct css_task_iter it
;
1568 struct task_struct
*task
;
1570 css_task_iter_start(&iter
->css
, &it
);
1571 while ((task
= css_task_iter_next(&it
))) {
1572 switch (oom_scan_process_thread(task
, totalpages
, NULL
,
1574 case OOM_SCAN_SELECT
:
1576 put_task_struct(chosen
);
1578 chosen_points
= ULONG_MAX
;
1579 get_task_struct(chosen
);
1581 case OOM_SCAN_CONTINUE
:
1583 case OOM_SCAN_ABORT
:
1584 css_task_iter_end(&it
);
1585 mem_cgroup_iter_break(memcg
, iter
);
1587 put_task_struct(chosen
);
1592 points
= oom_badness(task
, memcg
, NULL
, totalpages
);
1593 if (!points
|| points
< chosen_points
)
1595 /* Prefer thread group leaders for display purposes */
1596 if (points
== chosen_points
&&
1597 thread_group_leader(chosen
))
1601 put_task_struct(chosen
);
1603 chosen_points
= points
;
1604 get_task_struct(chosen
);
1606 css_task_iter_end(&it
);
1611 points
= chosen_points
* 1000 / totalpages
;
1612 oom_kill_process(chosen
, gfp_mask
, order
, points
, totalpages
, memcg
,
1613 NULL
, "Memory cgroup out of memory");
1616 #if MAX_NUMNODES > 1
1619 * test_mem_cgroup_node_reclaimable
1620 * @memcg: the target memcg
1621 * @nid: the node ID to be checked.
1622 * @noswap : specify true here if the user wants flle only information.
1624 * This function returns whether the specified memcg contains any
1625 * reclaimable pages on a node. Returns true if there are any reclaimable
1626 * pages in the node.
1628 static bool test_mem_cgroup_node_reclaimable(struct mem_cgroup
*memcg
,
1629 int nid
, bool noswap
)
1631 if (mem_cgroup_node_nr_lru_pages(memcg
, nid
, LRU_ALL_FILE
))
1633 if (noswap
|| !total_swap_pages
)
1635 if (mem_cgroup_node_nr_lru_pages(memcg
, nid
, LRU_ALL_ANON
))
1642 * Always updating the nodemask is not very good - even if we have an empty
1643 * list or the wrong list here, we can start from some node and traverse all
1644 * nodes based on the zonelist. So update the list loosely once per 10 secs.
1647 static void mem_cgroup_may_update_nodemask(struct mem_cgroup
*memcg
)
1651 * numainfo_events > 0 means there was at least NUMAINFO_EVENTS_TARGET
1652 * pagein/pageout changes since the last update.
1654 if (!atomic_read(&memcg
->numainfo_events
))
1656 if (atomic_inc_return(&memcg
->numainfo_updating
) > 1)
1659 /* make a nodemask where this memcg uses memory from */
1660 memcg
->scan_nodes
= node_states
[N_MEMORY
];
1662 for_each_node_mask(nid
, node_states
[N_MEMORY
]) {
1664 if (!test_mem_cgroup_node_reclaimable(memcg
, nid
, false))
1665 node_clear(nid
, memcg
->scan_nodes
);
1668 atomic_set(&memcg
->numainfo_events
, 0);
1669 atomic_set(&memcg
->numainfo_updating
, 0);
1673 * Selecting a node where we start reclaim from. Because what we need is just
1674 * reducing usage counter, start from anywhere is O,K. Considering
1675 * memory reclaim from current node, there are pros. and cons.
1677 * Freeing memory from current node means freeing memory from a node which
1678 * we'll use or we've used. So, it may make LRU bad. And if several threads
1679 * hit limits, it will see a contention on a node. But freeing from remote
1680 * node means more costs for memory reclaim because of memory latency.
1682 * Now, we use round-robin. Better algorithm is welcomed.
1684 int mem_cgroup_select_victim_node(struct mem_cgroup
*memcg
)
1688 mem_cgroup_may_update_nodemask(memcg
);
1689 node
= memcg
->last_scanned_node
;
1691 node
= next_node(node
, memcg
->scan_nodes
);
1692 if (node
== MAX_NUMNODES
)
1693 node
= first_node(memcg
->scan_nodes
);
1695 * We call this when we hit limit, not when pages are added to LRU.
1696 * No LRU may hold pages because all pages are UNEVICTABLE or
1697 * memcg is too small and all pages are not on LRU. In that case,
1698 * we use curret node.
1700 if (unlikely(node
== MAX_NUMNODES
))
1701 node
= numa_node_id();
1703 memcg
->last_scanned_node
= node
;
1707 int mem_cgroup_select_victim_node(struct mem_cgroup
*memcg
)
1713 static int mem_cgroup_soft_reclaim(struct mem_cgroup
*root_memcg
,
1716 unsigned long *total_scanned
)
1718 struct mem_cgroup
*victim
= NULL
;
1721 unsigned long excess
;
1722 unsigned long nr_scanned
;
1723 struct mem_cgroup_reclaim_cookie reclaim
= {
1728 excess
= soft_limit_excess(root_memcg
);
1731 victim
= mem_cgroup_iter(root_memcg
, victim
, &reclaim
);
1736 * If we have not been able to reclaim
1737 * anything, it might because there are
1738 * no reclaimable pages under this hierarchy
1743 * We want to do more targeted reclaim.
1744 * excess >> 2 is not to excessive so as to
1745 * reclaim too much, nor too less that we keep
1746 * coming back to reclaim from this cgroup
1748 if (total
>= (excess
>> 2) ||
1749 (loop
> MEM_CGROUP_MAX_RECLAIM_LOOPS
))
1754 total
+= mem_cgroup_shrink_node_zone(victim
, gfp_mask
, false,
1756 *total_scanned
+= nr_scanned
;
1757 if (!soft_limit_excess(root_memcg
))
1760 mem_cgroup_iter_break(root_memcg
, victim
);
1764 #ifdef CONFIG_LOCKDEP
1765 static struct lockdep_map memcg_oom_lock_dep_map
= {
1766 .name
= "memcg_oom_lock",
1770 static DEFINE_SPINLOCK(memcg_oom_lock
);
1773 * Check OOM-Killer is already running under our hierarchy.
1774 * If someone is running, return false.
1776 static bool mem_cgroup_oom_trylock(struct mem_cgroup
*memcg
)
1778 struct mem_cgroup
*iter
, *failed
= NULL
;
1780 spin_lock(&memcg_oom_lock
);
1782 for_each_mem_cgroup_tree(iter
, memcg
) {
1783 if (iter
->oom_lock
) {
1785 * this subtree of our hierarchy is already locked
1786 * so we cannot give a lock.
1789 mem_cgroup_iter_break(memcg
, iter
);
1792 iter
->oom_lock
= true;
1797 * OK, we failed to lock the whole subtree so we have
1798 * to clean up what we set up to the failing subtree
1800 for_each_mem_cgroup_tree(iter
, memcg
) {
1801 if (iter
== failed
) {
1802 mem_cgroup_iter_break(memcg
, iter
);
1805 iter
->oom_lock
= false;
1808 mutex_acquire(&memcg_oom_lock_dep_map
, 0, 1, _RET_IP_
);
1810 spin_unlock(&memcg_oom_lock
);
1815 static void mem_cgroup_oom_unlock(struct mem_cgroup
*memcg
)
1817 struct mem_cgroup
*iter
;
1819 spin_lock(&memcg_oom_lock
);
1820 mutex_release(&memcg_oom_lock_dep_map
, 1, _RET_IP_
);
1821 for_each_mem_cgroup_tree(iter
, memcg
)
1822 iter
->oom_lock
= false;
1823 spin_unlock(&memcg_oom_lock
);
1826 static void mem_cgroup_mark_under_oom(struct mem_cgroup
*memcg
)
1828 struct mem_cgroup
*iter
;
1830 for_each_mem_cgroup_tree(iter
, memcg
)
1831 atomic_inc(&iter
->under_oom
);
1834 static void mem_cgroup_unmark_under_oom(struct mem_cgroup
*memcg
)
1836 struct mem_cgroup
*iter
;
1839 * When a new child is created while the hierarchy is under oom,
1840 * mem_cgroup_oom_lock() may not be called. We have to use
1841 * atomic_add_unless() here.
1843 for_each_mem_cgroup_tree(iter
, memcg
)
1844 atomic_add_unless(&iter
->under_oom
, -1, 0);
1847 static DECLARE_WAIT_QUEUE_HEAD(memcg_oom_waitq
);
1849 struct oom_wait_info
{
1850 struct mem_cgroup
*memcg
;
1854 static int memcg_oom_wake_function(wait_queue_t
*wait
,
1855 unsigned mode
, int sync
, void *arg
)
1857 struct mem_cgroup
*wake_memcg
= (struct mem_cgroup
*)arg
;
1858 struct mem_cgroup
*oom_wait_memcg
;
1859 struct oom_wait_info
*oom_wait_info
;
1861 oom_wait_info
= container_of(wait
, struct oom_wait_info
, wait
);
1862 oom_wait_memcg
= oom_wait_info
->memcg
;
1864 if (!mem_cgroup_is_descendant(wake_memcg
, oom_wait_memcg
) &&
1865 !mem_cgroup_is_descendant(oom_wait_memcg
, wake_memcg
))
1867 return autoremove_wake_function(wait
, mode
, sync
, arg
);
1870 static void memcg_wakeup_oom(struct mem_cgroup
*memcg
)
1872 atomic_inc(&memcg
->oom_wakeups
);
1873 /* for filtering, pass "memcg" as argument. */
1874 __wake_up(&memcg_oom_waitq
, TASK_NORMAL
, 0, memcg
);
1877 static void memcg_oom_recover(struct mem_cgroup
*memcg
)
1879 if (memcg
&& atomic_read(&memcg
->under_oom
))
1880 memcg_wakeup_oom(memcg
);
1883 static void mem_cgroup_oom(struct mem_cgroup
*memcg
, gfp_t mask
, int order
)
1885 if (!current
->memcg_oom
.may_oom
)
1888 * We are in the middle of the charge context here, so we
1889 * don't want to block when potentially sitting on a callstack
1890 * that holds all kinds of filesystem and mm locks.
1892 * Also, the caller may handle a failed allocation gracefully
1893 * (like optional page cache readahead) and so an OOM killer
1894 * invocation might not even be necessary.
1896 * That's why we don't do anything here except remember the
1897 * OOM context and then deal with it at the end of the page
1898 * fault when the stack is unwound, the locks are released,
1899 * and when we know whether the fault was overall successful.
1901 css_get(&memcg
->css
);
1902 current
->memcg_oom
.memcg
= memcg
;
1903 current
->memcg_oom
.gfp_mask
= mask
;
1904 current
->memcg_oom
.order
= order
;
1908 * mem_cgroup_oom_synchronize - complete memcg OOM handling
1909 * @handle: actually kill/wait or just clean up the OOM state
1911 * This has to be called at the end of a page fault if the memcg OOM
1912 * handler was enabled.
1914 * Memcg supports userspace OOM handling where failed allocations must
1915 * sleep on a waitqueue until the userspace task resolves the
1916 * situation. Sleeping directly in the charge context with all kinds
1917 * of locks held is not a good idea, instead we remember an OOM state
1918 * in the task and mem_cgroup_oom_synchronize() has to be called at
1919 * the end of the page fault to complete the OOM handling.
1921 * Returns %true if an ongoing memcg OOM situation was detected and
1922 * completed, %false otherwise.
1924 bool mem_cgroup_oom_synchronize(bool handle
)
1926 struct mem_cgroup
*memcg
= current
->memcg_oom
.memcg
;
1927 struct oom_wait_info owait
;
1930 /* OOM is global, do not handle */
1937 owait
.memcg
= memcg
;
1938 owait
.wait
.flags
= 0;
1939 owait
.wait
.func
= memcg_oom_wake_function
;
1940 owait
.wait
.private = current
;
1941 INIT_LIST_HEAD(&owait
.wait
.task_list
);
1943 prepare_to_wait(&memcg_oom_waitq
, &owait
.wait
, TASK_KILLABLE
);
1944 mem_cgroup_mark_under_oom(memcg
);
1946 locked
= mem_cgroup_oom_trylock(memcg
);
1949 mem_cgroup_oom_notify(memcg
);
1951 if (locked
&& !memcg
->oom_kill_disable
) {
1952 mem_cgroup_unmark_under_oom(memcg
);
1953 finish_wait(&memcg_oom_waitq
, &owait
.wait
);
1954 mem_cgroup_out_of_memory(memcg
, current
->memcg_oom
.gfp_mask
,
1955 current
->memcg_oom
.order
);
1958 mem_cgroup_unmark_under_oom(memcg
);
1959 finish_wait(&memcg_oom_waitq
, &owait
.wait
);
1963 mem_cgroup_oom_unlock(memcg
);
1965 * There is no guarantee that an OOM-lock contender
1966 * sees the wakeups triggered by the OOM kill
1967 * uncharges. Wake any sleepers explicitely.
1969 memcg_oom_recover(memcg
);
1972 current
->memcg_oom
.memcg
= NULL
;
1973 css_put(&memcg
->css
);
1978 * mem_cgroup_begin_page_stat - begin a page state statistics transaction
1979 * @page: page that is going to change accounted state
1980 * @locked: &memcg->move_lock slowpath was taken
1981 * @flags: IRQ-state flags for &memcg->move_lock
1983 * This function must mark the beginning of an accounted page state
1984 * change to prevent double accounting when the page is concurrently
1985 * being moved to another memcg:
1987 * memcg = mem_cgroup_begin_page_stat(page, &locked, &flags);
1988 * if (TestClearPageState(page))
1989 * mem_cgroup_update_page_stat(memcg, state, -1);
1990 * mem_cgroup_end_page_stat(memcg, locked, flags);
1992 * The RCU lock is held throughout the transaction. The fast path can
1993 * get away without acquiring the memcg->move_lock (@locked is false)
1994 * because page moving starts with an RCU grace period.
1996 * The RCU lock also protects the memcg from being freed when the page
1997 * state that is going to change is the only thing preventing the page
1998 * from being uncharged. E.g. end-writeback clearing PageWriteback(),
1999 * which allows migration to go ahead and uncharge the page before the
2000 * account transaction might be complete.
2002 struct mem_cgroup
*mem_cgroup_begin_page_stat(struct page
*page
,
2004 unsigned long *flags
)
2006 struct mem_cgroup
*memcg
;
2010 if (mem_cgroup_disabled())
2013 memcg
= page
->mem_cgroup
;
2014 if (unlikely(!memcg
))
2018 if (atomic_read(&memcg
->moving_account
) <= 0)
2021 spin_lock_irqsave(&memcg
->move_lock
, *flags
);
2022 if (memcg
!= page
->mem_cgroup
) {
2023 spin_unlock_irqrestore(&memcg
->move_lock
, *flags
);
2032 * mem_cgroup_end_page_stat - finish a page state statistics transaction
2033 * @memcg: the memcg that was accounted against
2034 * @locked: value received from mem_cgroup_begin_page_stat()
2035 * @flags: value received from mem_cgroup_begin_page_stat()
2037 void mem_cgroup_end_page_stat(struct mem_cgroup
*memcg
, bool *locked
,
2038 unsigned long *flags
)
2040 if (memcg
&& *locked
)
2041 spin_unlock_irqrestore(&memcg
->move_lock
, *flags
);
2047 * mem_cgroup_update_page_stat - update page state statistics
2048 * @memcg: memcg to account against
2049 * @idx: page state item to account
2050 * @val: number of pages (positive or negative)
2052 * See mem_cgroup_begin_page_stat() for locking requirements.
2054 void mem_cgroup_update_page_stat(struct mem_cgroup
*memcg
,
2055 enum mem_cgroup_stat_index idx
, int val
)
2057 VM_BUG_ON(!rcu_read_lock_held());
2060 this_cpu_add(memcg
->stat
->count
[idx
], val
);
2064 * size of first charge trial. "32" comes from vmscan.c's magic value.
2065 * TODO: maybe necessary to use big numbers in big irons.
2067 #define CHARGE_BATCH 32U
2068 struct memcg_stock_pcp
{
2069 struct mem_cgroup
*cached
; /* this never be root cgroup */
2070 unsigned int nr_pages
;
2071 struct work_struct work
;
2072 unsigned long flags
;
2073 #define FLUSHING_CACHED_CHARGE 0
2075 static DEFINE_PER_CPU(struct memcg_stock_pcp
, memcg_stock
);
2076 static DEFINE_MUTEX(percpu_charge_mutex
);
2079 * consume_stock: Try to consume stocked charge on this cpu.
2080 * @memcg: memcg to consume from.
2081 * @nr_pages: how many pages to charge.
2083 * The charges will only happen if @memcg matches the current cpu's memcg
2084 * stock, and at least @nr_pages are available in that stock. Failure to
2085 * service an allocation will refill the stock.
2087 * returns true if successful, false otherwise.
2089 static bool consume_stock(struct mem_cgroup
*memcg
, unsigned int nr_pages
)
2091 struct memcg_stock_pcp
*stock
;
2094 if (nr_pages
> CHARGE_BATCH
)
2097 stock
= &get_cpu_var(memcg_stock
);
2098 if (memcg
== stock
->cached
&& stock
->nr_pages
>= nr_pages
) {
2099 stock
->nr_pages
-= nr_pages
;
2102 put_cpu_var(memcg_stock
);
2107 * Returns stocks cached in percpu and reset cached information.
2109 static void drain_stock(struct memcg_stock_pcp
*stock
)
2111 struct mem_cgroup
*old
= stock
->cached
;
2113 if (stock
->nr_pages
) {
2114 page_counter_uncharge(&old
->memory
, stock
->nr_pages
);
2115 if (do_swap_account
)
2116 page_counter_uncharge(&old
->memsw
, stock
->nr_pages
);
2117 css_put_many(&old
->css
, stock
->nr_pages
);
2118 stock
->nr_pages
= 0;
2120 stock
->cached
= NULL
;
2124 * This must be called under preempt disabled or must be called by
2125 * a thread which is pinned to local cpu.
2127 static void drain_local_stock(struct work_struct
*dummy
)
2129 struct memcg_stock_pcp
*stock
= this_cpu_ptr(&memcg_stock
);
2131 clear_bit(FLUSHING_CACHED_CHARGE
, &stock
->flags
);
2134 static void __init
memcg_stock_init(void)
2138 for_each_possible_cpu(cpu
) {
2139 struct memcg_stock_pcp
*stock
=
2140 &per_cpu(memcg_stock
, cpu
);
2141 INIT_WORK(&stock
->work
, drain_local_stock
);
2146 * Cache charges(val) to local per_cpu area.
2147 * This will be consumed by consume_stock() function, later.
2149 static void refill_stock(struct mem_cgroup
*memcg
, unsigned int nr_pages
)
2151 struct memcg_stock_pcp
*stock
= &get_cpu_var(memcg_stock
);
2153 if (stock
->cached
!= memcg
) { /* reset if necessary */
2155 stock
->cached
= memcg
;
2157 stock
->nr_pages
+= nr_pages
;
2158 put_cpu_var(memcg_stock
);
2162 * Drains all per-CPU charge caches for given root_memcg resp. subtree
2163 * of the hierarchy under it.
2165 static void drain_all_stock(struct mem_cgroup
*root_memcg
)
2169 /* If someone's already draining, avoid adding running more workers. */
2170 if (!mutex_trylock(&percpu_charge_mutex
))
2172 /* Notify other cpus that system-wide "drain" is running */
2175 for_each_online_cpu(cpu
) {
2176 struct memcg_stock_pcp
*stock
= &per_cpu(memcg_stock
, cpu
);
2177 struct mem_cgroup
*memcg
;
2179 memcg
= stock
->cached
;
2180 if (!memcg
|| !stock
->nr_pages
)
2182 if (!mem_cgroup_is_descendant(memcg
, root_memcg
))
2184 if (!test_and_set_bit(FLUSHING_CACHED_CHARGE
, &stock
->flags
)) {
2186 drain_local_stock(&stock
->work
);
2188 schedule_work_on(cpu
, &stock
->work
);
2193 mutex_unlock(&percpu_charge_mutex
);
2197 * This function drains percpu counter value from DEAD cpu and
2198 * move it to local cpu. Note that this function can be preempted.
2200 static void mem_cgroup_drain_pcp_counter(struct mem_cgroup
*memcg
, int cpu
)
2204 spin_lock(&memcg
->pcp_counter_lock
);
2205 for (i
= 0; i
< MEM_CGROUP_STAT_NSTATS
; i
++) {
2206 long x
= per_cpu(memcg
->stat
->count
[i
], cpu
);
2208 per_cpu(memcg
->stat
->count
[i
], cpu
) = 0;
2209 memcg
->nocpu_base
.count
[i
] += x
;
2211 for (i
= 0; i
< MEM_CGROUP_EVENTS_NSTATS
; i
++) {
2212 unsigned long x
= per_cpu(memcg
->stat
->events
[i
], cpu
);
2214 per_cpu(memcg
->stat
->events
[i
], cpu
) = 0;
2215 memcg
->nocpu_base
.events
[i
] += x
;
2217 spin_unlock(&memcg
->pcp_counter_lock
);
2220 static int memcg_cpu_hotplug_callback(struct notifier_block
*nb
,
2221 unsigned long action
,
2224 int cpu
= (unsigned long)hcpu
;
2225 struct memcg_stock_pcp
*stock
;
2226 struct mem_cgroup
*iter
;
2228 if (action
== CPU_ONLINE
)
2231 if (action
!= CPU_DEAD
&& action
!= CPU_DEAD_FROZEN
)
2234 for_each_mem_cgroup(iter
)
2235 mem_cgroup_drain_pcp_counter(iter
, cpu
);
2237 stock
= &per_cpu(memcg_stock
, cpu
);
2242 static int try_charge(struct mem_cgroup
*memcg
, gfp_t gfp_mask
,
2243 unsigned int nr_pages
)
2245 unsigned int batch
= max(CHARGE_BATCH
, nr_pages
);
2246 int nr_retries
= MEM_CGROUP_RECLAIM_RETRIES
;
2247 struct mem_cgroup
*mem_over_limit
;
2248 struct page_counter
*counter
;
2249 unsigned long nr_reclaimed
;
2250 bool may_swap
= true;
2251 bool drained
= false;
2254 if (mem_cgroup_is_root(memcg
))
2257 if (consume_stock(memcg
, nr_pages
))
2260 if (!do_swap_account
||
2261 !page_counter_try_charge(&memcg
->memsw
, batch
, &counter
)) {
2262 if (!page_counter_try_charge(&memcg
->memory
, batch
, &counter
))
2264 if (do_swap_account
)
2265 page_counter_uncharge(&memcg
->memsw
, batch
);
2266 mem_over_limit
= mem_cgroup_from_counter(counter
, memory
);
2268 mem_over_limit
= mem_cgroup_from_counter(counter
, memsw
);
2272 if (batch
> nr_pages
) {
2278 * Unlike in global OOM situations, memcg is not in a physical
2279 * memory shortage. Allow dying and OOM-killed tasks to
2280 * bypass the last charges so that they can exit quickly and
2281 * free their memory.
2283 if (unlikely(test_thread_flag(TIF_MEMDIE
) ||
2284 fatal_signal_pending(current
) ||
2285 current
->flags
& PF_EXITING
))
2288 if (unlikely(task_in_memcg_oom(current
)))
2291 if (!(gfp_mask
& __GFP_WAIT
))
2294 nr_reclaimed
= try_to_free_mem_cgroup_pages(mem_over_limit
, nr_pages
,
2295 gfp_mask
, may_swap
);
2297 if (mem_cgroup_margin(mem_over_limit
) >= nr_pages
)
2301 drain_all_stock(mem_over_limit
);
2306 if (gfp_mask
& __GFP_NORETRY
)
2309 * Even though the limit is exceeded at this point, reclaim
2310 * may have been able to free some pages. Retry the charge
2311 * before killing the task.
2313 * Only for regular pages, though: huge pages are rather
2314 * unlikely to succeed so close to the limit, and we fall back
2315 * to regular pages anyway in case of failure.
2317 if (nr_reclaimed
&& nr_pages
<= (1 << PAGE_ALLOC_COSTLY_ORDER
))
2320 * At task move, charge accounts can be doubly counted. So, it's
2321 * better to wait until the end of task_move if something is going on.
2323 if (mem_cgroup_wait_acct_move(mem_over_limit
))
2329 if (gfp_mask
& __GFP_NOFAIL
)
2332 if (fatal_signal_pending(current
))
2335 mem_cgroup_oom(mem_over_limit
, gfp_mask
, get_order(nr_pages
));
2337 if (!(gfp_mask
& __GFP_NOFAIL
))
2343 css_get_many(&memcg
->css
, batch
);
2344 if (batch
> nr_pages
)
2345 refill_stock(memcg
, batch
- nr_pages
);
2350 static void cancel_charge(struct mem_cgroup
*memcg
, unsigned int nr_pages
)
2352 if (mem_cgroup_is_root(memcg
))
2355 page_counter_uncharge(&memcg
->memory
, nr_pages
);
2356 if (do_swap_account
)
2357 page_counter_uncharge(&memcg
->memsw
, nr_pages
);
2359 css_put_many(&memcg
->css
, nr_pages
);
2363 * A helper function to get mem_cgroup from ID. must be called under
2364 * rcu_read_lock(). The caller is responsible for calling
2365 * css_tryget_online() if the mem_cgroup is used for charging. (dropping
2366 * refcnt from swap can be called against removed memcg.)
2368 static struct mem_cgroup
*mem_cgroup_lookup(unsigned short id
)
2370 /* ID 0 is unused ID */
2373 return mem_cgroup_from_id(id
);
2377 * try_get_mem_cgroup_from_page - look up page's memcg association
2380 * Look up, get a css reference, and return the memcg that owns @page.
2382 * The page must be locked to prevent racing with swap-in and page
2383 * cache charges. If coming from an unlocked page table, the caller
2384 * must ensure the page is on the LRU or this can race with charging.
2386 struct mem_cgroup
*try_get_mem_cgroup_from_page(struct page
*page
)
2388 struct mem_cgroup
*memcg
;
2392 VM_BUG_ON_PAGE(!PageLocked(page
), page
);
2394 memcg
= page
->mem_cgroup
;
2396 if (!css_tryget_online(&memcg
->css
))
2398 } else if (PageSwapCache(page
)) {
2399 ent
.val
= page_private(page
);
2400 id
= lookup_swap_cgroup_id(ent
);
2402 memcg
= mem_cgroup_lookup(id
);
2403 if (memcg
&& !css_tryget_online(&memcg
->css
))
2410 static void lock_page_lru(struct page
*page
, int *isolated
)
2412 struct zone
*zone
= page_zone(page
);
2414 spin_lock_irq(&zone
->lru_lock
);
2415 if (PageLRU(page
)) {
2416 struct lruvec
*lruvec
;
2418 lruvec
= mem_cgroup_page_lruvec(page
, zone
);
2420 del_page_from_lru_list(page
, lruvec
, page_lru(page
));
2426 static void unlock_page_lru(struct page
*page
, int isolated
)
2428 struct zone
*zone
= page_zone(page
);
2431 struct lruvec
*lruvec
;
2433 lruvec
= mem_cgroup_page_lruvec(page
, zone
);
2434 VM_BUG_ON_PAGE(PageLRU(page
), page
);
2436 add_page_to_lru_list(page
, lruvec
, page_lru(page
));
2438 spin_unlock_irq(&zone
->lru_lock
);
2441 static void commit_charge(struct page
*page
, struct mem_cgroup
*memcg
,
2446 VM_BUG_ON_PAGE(page
->mem_cgroup
, page
);
2449 * In some cases, SwapCache and FUSE(splice_buf->radixtree), the page
2450 * may already be on some other mem_cgroup's LRU. Take care of it.
2453 lock_page_lru(page
, &isolated
);
2456 * Nobody should be changing or seriously looking at
2457 * page->mem_cgroup at this point:
2459 * - the page is uncharged
2461 * - the page is off-LRU
2463 * - an anonymous fault has exclusive page access, except for
2464 * a locked page table
2466 * - a page cache insertion, a swapin fault, or a migration
2467 * have the page locked
2469 page
->mem_cgroup
= memcg
;
2472 unlock_page_lru(page
, isolated
);
2475 #ifdef CONFIG_MEMCG_KMEM
2476 int memcg_charge_kmem(struct mem_cgroup
*memcg
, gfp_t gfp
,
2477 unsigned long nr_pages
)
2479 struct page_counter
*counter
;
2482 ret
= page_counter_try_charge(&memcg
->kmem
, nr_pages
, &counter
);
2486 ret
= try_charge(memcg
, gfp
, nr_pages
);
2487 if (ret
== -EINTR
) {
2489 * try_charge() chose to bypass to root due to OOM kill or
2490 * fatal signal. Since our only options are to either fail
2491 * the allocation or charge it to this cgroup, do it as a
2492 * temporary condition. But we can't fail. From a kmem/slab
2493 * perspective, the cache has already been selected, by
2494 * mem_cgroup_kmem_get_cache(), so it is too late to change
2497 * This condition will only trigger if the task entered
2498 * memcg_charge_kmem in a sane state, but was OOM-killed
2499 * during try_charge() above. Tasks that were already dying
2500 * when the allocation triggers should have been already
2501 * directed to the root cgroup in memcontrol.h
2503 page_counter_charge(&memcg
->memory
, nr_pages
);
2504 if (do_swap_account
)
2505 page_counter_charge(&memcg
->memsw
, nr_pages
);
2506 css_get_many(&memcg
->css
, nr_pages
);
2509 page_counter_uncharge(&memcg
->kmem
, nr_pages
);
2514 void memcg_uncharge_kmem(struct mem_cgroup
*memcg
, unsigned long nr_pages
)
2516 page_counter_uncharge(&memcg
->memory
, nr_pages
);
2517 if (do_swap_account
)
2518 page_counter_uncharge(&memcg
->memsw
, nr_pages
);
2520 page_counter_uncharge(&memcg
->kmem
, nr_pages
);
2522 css_put_many(&memcg
->css
, nr_pages
);
2526 * helper for acessing a memcg's index. It will be used as an index in the
2527 * child cache array in kmem_cache, and also to derive its name. This function
2528 * will return -1 when this is not a kmem-limited memcg.
2530 int memcg_cache_id(struct mem_cgroup
*memcg
)
2532 return memcg
? memcg
->kmemcg_id
: -1;
2535 static int memcg_alloc_cache_id(void)
2540 id
= ida_simple_get(&kmem_limited_groups
,
2541 0, MEMCG_CACHES_MAX_SIZE
, GFP_KERNEL
);
2545 if (id
< memcg_limited_groups_array_size
)
2549 * There's no space for the new id in memcg_caches arrays,
2550 * so we have to grow them.
2553 size
= 2 * (id
+ 1);
2554 if (size
< MEMCG_CACHES_MIN_SIZE
)
2555 size
= MEMCG_CACHES_MIN_SIZE
;
2556 else if (size
> MEMCG_CACHES_MAX_SIZE
)
2557 size
= MEMCG_CACHES_MAX_SIZE
;
2559 err
= memcg_update_all_caches(size
);
2561 ida_simple_remove(&kmem_limited_groups
, id
);
2567 static void memcg_free_cache_id(int id
)
2569 ida_simple_remove(&kmem_limited_groups
, id
);
2573 * We should update the current array size iff all caches updates succeed. This
2574 * can only be done from the slab side. The slab mutex needs to be held when
2577 void memcg_update_array_size(int num
)
2579 memcg_limited_groups_array_size
= num
;
2582 struct memcg_kmem_cache_create_work
{
2583 struct mem_cgroup
*memcg
;
2584 struct kmem_cache
*cachep
;
2585 struct work_struct work
;
2588 static void memcg_kmem_cache_create_func(struct work_struct
*w
)
2590 struct memcg_kmem_cache_create_work
*cw
=
2591 container_of(w
, struct memcg_kmem_cache_create_work
, work
);
2592 struct mem_cgroup
*memcg
= cw
->memcg
;
2593 struct kmem_cache
*cachep
= cw
->cachep
;
2595 memcg_create_kmem_cache(memcg
, cachep
);
2597 css_put(&memcg
->css
);
2602 * Enqueue the creation of a per-memcg kmem_cache.
2604 static void __memcg_schedule_kmem_cache_create(struct mem_cgroup
*memcg
,
2605 struct kmem_cache
*cachep
)
2607 struct memcg_kmem_cache_create_work
*cw
;
2609 cw
= kmalloc(sizeof(*cw
), GFP_NOWAIT
);
2613 css_get(&memcg
->css
);
2616 cw
->cachep
= cachep
;
2617 INIT_WORK(&cw
->work
, memcg_kmem_cache_create_func
);
2619 schedule_work(&cw
->work
);
2622 static void memcg_schedule_kmem_cache_create(struct mem_cgroup
*memcg
,
2623 struct kmem_cache
*cachep
)
2626 * We need to stop accounting when we kmalloc, because if the
2627 * corresponding kmalloc cache is not yet created, the first allocation
2628 * in __memcg_schedule_kmem_cache_create will recurse.
2630 * However, it is better to enclose the whole function. Depending on
2631 * the debugging options enabled, INIT_WORK(), for instance, can
2632 * trigger an allocation. This too, will make us recurse. Because at
2633 * this point we can't allow ourselves back into memcg_kmem_get_cache,
2634 * the safest choice is to do it like this, wrapping the whole function.
2636 current
->memcg_kmem_skip_account
= 1;
2637 __memcg_schedule_kmem_cache_create(memcg
, cachep
);
2638 current
->memcg_kmem_skip_account
= 0;
2642 * Return the kmem_cache we're supposed to use for a slab allocation.
2643 * We try to use the current memcg's version of the cache.
2645 * If the cache does not exist yet, if we are the first user of it,
2646 * we either create it immediately, if possible, or create it asynchronously
2648 * In the latter case, we will let the current allocation go through with
2649 * the original cache.
2651 * Can't be called in interrupt context or from kernel threads.
2652 * This function needs to be called with rcu_read_lock() held.
2654 struct kmem_cache
*__memcg_kmem_get_cache(struct kmem_cache
*cachep
)
2656 struct mem_cgroup
*memcg
;
2657 struct kmem_cache
*memcg_cachep
;
2659 VM_BUG_ON(!cachep
->memcg_params
);
2660 VM_BUG_ON(!cachep
->memcg_params
->is_root_cache
);
2662 if (current
->memcg_kmem_skip_account
)
2665 memcg
= get_mem_cgroup_from_mm(current
->mm
);
2666 if (!memcg_kmem_is_active(memcg
))
2669 memcg_cachep
= cache_from_memcg_idx(cachep
, memcg_cache_id(memcg
));
2670 if (likely(memcg_cachep
))
2671 return memcg_cachep
;
2674 * If we are in a safe context (can wait, and not in interrupt
2675 * context), we could be be predictable and return right away.
2676 * This would guarantee that the allocation being performed
2677 * already belongs in the new cache.
2679 * However, there are some clashes that can arrive from locking.
2680 * For instance, because we acquire the slab_mutex while doing
2681 * memcg_create_kmem_cache, this means no further allocation
2682 * could happen with the slab_mutex held. So it's better to
2685 memcg_schedule_kmem_cache_create(memcg
, cachep
);
2687 css_put(&memcg
->css
);
2691 void __memcg_kmem_put_cache(struct kmem_cache
*cachep
)
2693 if (!is_root_cache(cachep
))
2694 css_put(&cachep
->memcg_params
->memcg
->css
);
2698 * We need to verify if the allocation against current->mm->owner's memcg is
2699 * possible for the given order. But the page is not allocated yet, so we'll
2700 * need a further commit step to do the final arrangements.
2702 * It is possible for the task to switch cgroups in this mean time, so at
2703 * commit time, we can't rely on task conversion any longer. We'll then use
2704 * the handle argument to return to the caller which cgroup we should commit
2705 * against. We could also return the memcg directly and avoid the pointer
2706 * passing, but a boolean return value gives better semantics considering
2707 * the compiled-out case as well.
2709 * Returning true means the allocation is possible.
2712 __memcg_kmem_newpage_charge(gfp_t gfp
, struct mem_cgroup
**_memcg
, int order
)
2714 struct mem_cgroup
*memcg
;
2719 memcg
= get_mem_cgroup_from_mm(current
->mm
);
2721 if (!memcg_kmem_is_active(memcg
)) {
2722 css_put(&memcg
->css
);
2726 ret
= memcg_charge_kmem(memcg
, gfp
, 1 << order
);
2730 css_put(&memcg
->css
);
2734 void __memcg_kmem_commit_charge(struct page
*page
, struct mem_cgroup
*memcg
,
2737 VM_BUG_ON(mem_cgroup_is_root(memcg
));
2739 /* The page allocation failed. Revert */
2741 memcg_uncharge_kmem(memcg
, 1 << order
);
2744 page
->mem_cgroup
= memcg
;
2747 void __memcg_kmem_uncharge_pages(struct page
*page
, int order
)
2749 struct mem_cgroup
*memcg
= page
->mem_cgroup
;
2754 VM_BUG_ON_PAGE(mem_cgroup_is_root(memcg
), page
);
2756 memcg_uncharge_kmem(memcg
, 1 << order
);
2757 page
->mem_cgroup
= NULL
;
2759 #endif /* CONFIG_MEMCG_KMEM */
2761 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
2764 * Because tail pages are not marked as "used", set it. We're under
2765 * zone->lru_lock, 'splitting on pmd' and compound_lock.
2766 * charge/uncharge will be never happen and move_account() is done under
2767 * compound_lock(), so we don't have to take care of races.
2769 void mem_cgroup_split_huge_fixup(struct page
*head
)
2773 if (mem_cgroup_disabled())
2776 for (i
= 1; i
< HPAGE_PMD_NR
; i
++)
2777 head
[i
].mem_cgroup
= head
->mem_cgroup
;
2779 __this_cpu_sub(head
->mem_cgroup
->stat
->count
[MEM_CGROUP_STAT_RSS_HUGE
],
2782 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
2785 * mem_cgroup_move_account - move account of the page
2787 * @nr_pages: number of regular pages (>1 for huge pages)
2788 * @from: mem_cgroup which the page is moved from.
2789 * @to: mem_cgroup which the page is moved to. @from != @to.
2791 * The caller must confirm following.
2792 * - page is not on LRU (isolate_page() is useful.)
2793 * - compound_lock is held when nr_pages > 1
2795 * This function doesn't do "charge" to new cgroup and doesn't do "uncharge"
2798 static int mem_cgroup_move_account(struct page
*page
,
2799 unsigned int nr_pages
,
2800 struct mem_cgroup
*from
,
2801 struct mem_cgroup
*to
)
2803 unsigned long flags
;
2806 VM_BUG_ON(from
== to
);
2807 VM_BUG_ON_PAGE(PageLRU(page
), page
);
2809 * The page is isolated from LRU. So, collapse function
2810 * will not handle this page. But page splitting can happen.
2811 * Do this check under compound_page_lock(). The caller should
2815 if (nr_pages
> 1 && !PageTransHuge(page
))
2819 * Prevent mem_cgroup_migrate() from looking at page->mem_cgroup
2820 * of its source page while we change it: page migration takes
2821 * both pages off the LRU, but page cache replacement doesn't.
2823 if (!trylock_page(page
))
2827 if (page
->mem_cgroup
!= from
)
2830 spin_lock_irqsave(&from
->move_lock
, flags
);
2832 if (!PageAnon(page
) && page_mapped(page
)) {
2833 __this_cpu_sub(from
->stat
->count
[MEM_CGROUP_STAT_FILE_MAPPED
],
2835 __this_cpu_add(to
->stat
->count
[MEM_CGROUP_STAT_FILE_MAPPED
],
2839 if (PageWriteback(page
)) {
2840 __this_cpu_sub(from
->stat
->count
[MEM_CGROUP_STAT_WRITEBACK
],
2842 __this_cpu_add(to
->stat
->count
[MEM_CGROUP_STAT_WRITEBACK
],
2847 * It is safe to change page->mem_cgroup here because the page
2848 * is referenced, charged, and isolated - we can't race with
2849 * uncharging, charging, migration, or LRU putback.
2852 /* caller should have done css_get */
2853 page
->mem_cgroup
= to
;
2854 spin_unlock_irqrestore(&from
->move_lock
, flags
);
2858 local_irq_disable();
2859 mem_cgroup_charge_statistics(to
, page
, nr_pages
);
2860 memcg_check_events(to
, page
);
2861 mem_cgroup_charge_statistics(from
, page
, -nr_pages
);
2862 memcg_check_events(from
, page
);
2870 #ifdef CONFIG_MEMCG_SWAP
2871 static void mem_cgroup_swap_statistics(struct mem_cgroup
*memcg
,
2874 int val
= (charge
) ? 1 : -1;
2875 this_cpu_add(memcg
->stat
->count
[MEM_CGROUP_STAT_SWAP
], val
);
2879 * mem_cgroup_move_swap_account - move swap charge and swap_cgroup's record.
2880 * @entry: swap entry to be moved
2881 * @from: mem_cgroup which the entry is moved from
2882 * @to: mem_cgroup which the entry is moved to
2884 * It succeeds only when the swap_cgroup's record for this entry is the same
2885 * as the mem_cgroup's id of @from.
2887 * Returns 0 on success, -EINVAL on failure.
2889 * The caller must have charged to @to, IOW, called page_counter_charge() about
2890 * both res and memsw, and called css_get().
2892 static int mem_cgroup_move_swap_account(swp_entry_t entry
,
2893 struct mem_cgroup
*from
, struct mem_cgroup
*to
)
2895 unsigned short old_id
, new_id
;
2897 old_id
= mem_cgroup_id(from
);
2898 new_id
= mem_cgroup_id(to
);
2900 if (swap_cgroup_cmpxchg(entry
, old_id
, new_id
) == old_id
) {
2901 mem_cgroup_swap_statistics(from
, false);
2902 mem_cgroup_swap_statistics(to
, true);
2908 static inline int mem_cgroup_move_swap_account(swp_entry_t entry
,
2909 struct mem_cgroup
*from
, struct mem_cgroup
*to
)
2915 static DEFINE_MUTEX(memcg_limit_mutex
);
2917 static int mem_cgroup_resize_limit(struct mem_cgroup
*memcg
,
2918 unsigned long limit
)
2920 unsigned long curusage
;
2921 unsigned long oldusage
;
2922 bool enlarge
= false;
2927 * For keeping hierarchical_reclaim simple, how long we should retry
2928 * is depends on callers. We set our retry-count to be function
2929 * of # of children which we should visit in this loop.
2931 retry_count
= MEM_CGROUP_RECLAIM_RETRIES
*
2932 mem_cgroup_count_children(memcg
);
2934 oldusage
= page_counter_read(&memcg
->memory
);
2937 if (signal_pending(current
)) {
2942 mutex_lock(&memcg_limit_mutex
);
2943 if (limit
> memcg
->memsw
.limit
) {
2944 mutex_unlock(&memcg_limit_mutex
);
2948 if (limit
> memcg
->memory
.limit
)
2950 ret
= page_counter_limit(&memcg
->memory
, limit
);
2951 mutex_unlock(&memcg_limit_mutex
);
2956 try_to_free_mem_cgroup_pages(memcg
, 1, GFP_KERNEL
, true);
2958 curusage
= page_counter_read(&memcg
->memory
);
2959 /* Usage is reduced ? */
2960 if (curusage
>= oldusage
)
2963 oldusage
= curusage
;
2964 } while (retry_count
);
2966 if (!ret
&& enlarge
)
2967 memcg_oom_recover(memcg
);
2972 static int mem_cgroup_resize_memsw_limit(struct mem_cgroup
*memcg
,
2973 unsigned long limit
)
2975 unsigned long curusage
;
2976 unsigned long oldusage
;
2977 bool enlarge
= false;
2981 /* see mem_cgroup_resize_res_limit */
2982 retry_count
= MEM_CGROUP_RECLAIM_RETRIES
*
2983 mem_cgroup_count_children(memcg
);
2985 oldusage
= page_counter_read(&memcg
->memsw
);
2988 if (signal_pending(current
)) {
2993 mutex_lock(&memcg_limit_mutex
);
2994 if (limit
< memcg
->memory
.limit
) {
2995 mutex_unlock(&memcg_limit_mutex
);
2999 if (limit
> memcg
->memsw
.limit
)
3001 ret
= page_counter_limit(&memcg
->memsw
, limit
);
3002 mutex_unlock(&memcg_limit_mutex
);
3007 try_to_free_mem_cgroup_pages(memcg
, 1, GFP_KERNEL
, false);
3009 curusage
= page_counter_read(&memcg
->memsw
);
3010 /* Usage is reduced ? */
3011 if (curusage
>= oldusage
)
3014 oldusage
= curusage
;
3015 } while (retry_count
);
3017 if (!ret
&& enlarge
)
3018 memcg_oom_recover(memcg
);
3023 unsigned long mem_cgroup_soft_limit_reclaim(struct zone
*zone
, int order
,
3025 unsigned long *total_scanned
)
3027 unsigned long nr_reclaimed
= 0;
3028 struct mem_cgroup_per_zone
*mz
, *next_mz
= NULL
;
3029 unsigned long reclaimed
;
3031 struct mem_cgroup_tree_per_zone
*mctz
;
3032 unsigned long excess
;
3033 unsigned long nr_scanned
;
3038 mctz
= soft_limit_tree_node_zone(zone_to_nid(zone
), zone_idx(zone
));
3040 * This loop can run a while, specially if mem_cgroup's continuously
3041 * keep exceeding their soft limit and putting the system under
3048 mz
= mem_cgroup_largest_soft_limit_node(mctz
);
3053 reclaimed
= mem_cgroup_soft_reclaim(mz
->memcg
, zone
,
3054 gfp_mask
, &nr_scanned
);
3055 nr_reclaimed
+= reclaimed
;
3056 *total_scanned
+= nr_scanned
;
3057 spin_lock_irq(&mctz
->lock
);
3058 __mem_cgroup_remove_exceeded(mz
, mctz
);
3061 * If we failed to reclaim anything from this memory cgroup
3062 * it is time to move on to the next cgroup
3066 next_mz
= __mem_cgroup_largest_soft_limit_node(mctz
);
3068 excess
= soft_limit_excess(mz
->memcg
);
3070 * One school of thought says that we should not add
3071 * back the node to the tree if reclaim returns 0.
3072 * But our reclaim could return 0, simply because due
3073 * to priority we are exposing a smaller subset of
3074 * memory to reclaim from. Consider this as a longer
3077 /* If excess == 0, no tree ops */
3078 __mem_cgroup_insert_exceeded(mz
, mctz
, excess
);
3079 spin_unlock_irq(&mctz
->lock
);
3080 css_put(&mz
->memcg
->css
);
3083 * Could not reclaim anything and there are no more
3084 * mem cgroups to try or we seem to be looping without
3085 * reclaiming anything.
3087 if (!nr_reclaimed
&&
3089 loop
> MEM_CGROUP_MAX_SOFT_LIMIT_RECLAIM_LOOPS
))
3091 } while (!nr_reclaimed
);
3093 css_put(&next_mz
->memcg
->css
);
3094 return nr_reclaimed
;
3098 * Test whether @memcg has children, dead or alive. Note that this
3099 * function doesn't care whether @memcg has use_hierarchy enabled and
3100 * returns %true if there are child csses according to the cgroup
3101 * hierarchy. Testing use_hierarchy is the caller's responsiblity.
3103 static inline bool memcg_has_children(struct mem_cgroup
*memcg
)
3108 * The lock does not prevent addition or deletion of children, but
3109 * it prevents a new child from being initialized based on this
3110 * parent in css_online(), so it's enough to decide whether
3111 * hierarchically inherited attributes can still be changed or not.
3113 lockdep_assert_held(&memcg_create_mutex
);
3116 ret
= css_next_child(NULL
, &memcg
->css
);
3122 * Reclaims as many pages from the given memcg as possible and moves
3123 * the rest to the parent.
3125 * Caller is responsible for holding css reference for memcg.
3127 static int mem_cgroup_force_empty(struct mem_cgroup
*memcg
)
3129 int nr_retries
= MEM_CGROUP_RECLAIM_RETRIES
;
3131 /* we call try-to-free pages for make this cgroup empty */
3132 lru_add_drain_all();
3133 /* try to free all pages in this cgroup */
3134 while (nr_retries
&& page_counter_read(&memcg
->memory
)) {
3137 if (signal_pending(current
))
3140 progress
= try_to_free_mem_cgroup_pages(memcg
, 1,
3144 /* maybe some writeback is necessary */
3145 congestion_wait(BLK_RW_ASYNC
, HZ
/10);
3153 static ssize_t
mem_cgroup_force_empty_write(struct kernfs_open_file
*of
,
3154 char *buf
, size_t nbytes
,
3157 struct mem_cgroup
*memcg
= mem_cgroup_from_css(of_css(of
));
3159 if (mem_cgroup_is_root(memcg
))
3161 return mem_cgroup_force_empty(memcg
) ?: nbytes
;
3164 static u64
mem_cgroup_hierarchy_read(struct cgroup_subsys_state
*css
,
3167 return mem_cgroup_from_css(css
)->use_hierarchy
;
3170 static int mem_cgroup_hierarchy_write(struct cgroup_subsys_state
*css
,
3171 struct cftype
*cft
, u64 val
)
3174 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
3175 struct mem_cgroup
*parent_memcg
= mem_cgroup_from_css(memcg
->css
.parent
);
3177 mutex_lock(&memcg_create_mutex
);
3179 if (memcg
->use_hierarchy
== val
)
3183 * If parent's use_hierarchy is set, we can't make any modifications
3184 * in the child subtrees. If it is unset, then the change can
3185 * occur, provided the current cgroup has no children.
3187 * For the root cgroup, parent_mem is NULL, we allow value to be
3188 * set if there are no children.
3190 if ((!parent_memcg
|| !parent_memcg
->use_hierarchy
) &&
3191 (val
== 1 || val
== 0)) {
3192 if (!memcg_has_children(memcg
))
3193 memcg
->use_hierarchy
= val
;
3200 mutex_unlock(&memcg_create_mutex
);
3205 static unsigned long tree_stat(struct mem_cgroup
*memcg
,
3206 enum mem_cgroup_stat_index idx
)
3208 struct mem_cgroup
*iter
;
3211 /* Per-cpu values can be negative, use a signed accumulator */
3212 for_each_mem_cgroup_tree(iter
, memcg
)
3213 val
+= mem_cgroup_read_stat(iter
, idx
);
3215 if (val
< 0) /* race ? */
3220 static inline u64
mem_cgroup_usage(struct mem_cgroup
*memcg
, bool swap
)
3224 if (mem_cgroup_is_root(memcg
)) {
3225 val
= tree_stat(memcg
, MEM_CGROUP_STAT_CACHE
);
3226 val
+= tree_stat(memcg
, MEM_CGROUP_STAT_RSS
);
3228 val
+= tree_stat(memcg
, MEM_CGROUP_STAT_SWAP
);
3231 val
= page_counter_read(&memcg
->memory
);
3233 val
= page_counter_read(&memcg
->memsw
);
3235 return val
<< PAGE_SHIFT
;
3246 static u64
mem_cgroup_read_u64(struct cgroup_subsys_state
*css
,
3249 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
3250 struct page_counter
*counter
;
3252 switch (MEMFILE_TYPE(cft
->private)) {
3254 counter
= &memcg
->memory
;
3257 counter
= &memcg
->memsw
;
3260 counter
= &memcg
->kmem
;
3266 switch (MEMFILE_ATTR(cft
->private)) {
3268 if (counter
== &memcg
->memory
)
3269 return mem_cgroup_usage(memcg
, false);
3270 if (counter
== &memcg
->memsw
)
3271 return mem_cgroup_usage(memcg
, true);
3272 return (u64
)page_counter_read(counter
) * PAGE_SIZE
;
3274 return (u64
)counter
->limit
* PAGE_SIZE
;
3276 return (u64
)counter
->watermark
* PAGE_SIZE
;
3278 return counter
->failcnt
;
3279 case RES_SOFT_LIMIT
:
3280 return (u64
)memcg
->soft_limit
* PAGE_SIZE
;
3286 #ifdef CONFIG_MEMCG_KMEM
3287 static int memcg_activate_kmem(struct mem_cgroup
*memcg
,
3288 unsigned long nr_pages
)
3293 if (memcg_kmem_is_active(memcg
))
3297 * For simplicity, we won't allow this to be disabled. It also can't
3298 * be changed if the cgroup has children already, or if tasks had
3301 * If tasks join before we set the limit, a person looking at
3302 * kmem.usage_in_bytes will have no way to determine when it took
3303 * place, which makes the value quite meaningless.
3305 * After it first became limited, changes in the value of the limit are
3306 * of course permitted.
3308 mutex_lock(&memcg_create_mutex
);
3309 if (cgroup_has_tasks(memcg
->css
.cgroup
) ||
3310 (memcg
->use_hierarchy
&& memcg_has_children(memcg
)))
3312 mutex_unlock(&memcg_create_mutex
);
3316 memcg_id
= memcg_alloc_cache_id();
3323 * We couldn't have accounted to this cgroup, because it hasn't got
3324 * activated yet, so this should succeed.
3326 err
= page_counter_limit(&memcg
->kmem
, nr_pages
);
3329 static_key_slow_inc(&memcg_kmem_enabled_key
);
3331 * A memory cgroup is considered kmem-active as soon as it gets
3332 * kmemcg_id. Setting the id after enabling static branching will
3333 * guarantee no one starts accounting before all call sites are
3336 memcg
->kmemcg_id
= memcg_id
;
3341 static int memcg_update_kmem_limit(struct mem_cgroup
*memcg
,
3342 unsigned long limit
)
3346 mutex_lock(&memcg_limit_mutex
);
3347 if (!memcg_kmem_is_active(memcg
))
3348 ret
= memcg_activate_kmem(memcg
, limit
);
3350 ret
= page_counter_limit(&memcg
->kmem
, limit
);
3351 mutex_unlock(&memcg_limit_mutex
);
3355 static int memcg_propagate_kmem(struct mem_cgroup
*memcg
)
3358 struct mem_cgroup
*parent
= parent_mem_cgroup(memcg
);
3363 mutex_lock(&memcg_limit_mutex
);
3365 * If the parent cgroup is not kmem-active now, it cannot be activated
3366 * after this point, because it has at least one child already.
3368 if (memcg_kmem_is_active(parent
))
3369 ret
= memcg_activate_kmem(memcg
, PAGE_COUNTER_MAX
);
3370 mutex_unlock(&memcg_limit_mutex
);
3374 static int memcg_update_kmem_limit(struct mem_cgroup
*memcg
,
3375 unsigned long limit
)
3379 #endif /* CONFIG_MEMCG_KMEM */
3382 * The user of this function is...
3385 static ssize_t
mem_cgroup_write(struct kernfs_open_file
*of
,
3386 char *buf
, size_t nbytes
, loff_t off
)
3388 struct mem_cgroup
*memcg
= mem_cgroup_from_css(of_css(of
));
3389 unsigned long nr_pages
;
3392 buf
= strstrip(buf
);
3393 ret
= page_counter_memparse(buf
, &nr_pages
);
3397 switch (MEMFILE_ATTR(of_cft(of
)->private)) {
3399 if (mem_cgroup_is_root(memcg
)) { /* Can't set limit on root */
3403 switch (MEMFILE_TYPE(of_cft(of
)->private)) {
3405 ret
= mem_cgroup_resize_limit(memcg
, nr_pages
);
3408 ret
= mem_cgroup_resize_memsw_limit(memcg
, nr_pages
);
3411 ret
= memcg_update_kmem_limit(memcg
, nr_pages
);
3415 case RES_SOFT_LIMIT
:
3416 memcg
->soft_limit
= nr_pages
;
3420 return ret
?: nbytes
;
3423 static ssize_t
mem_cgroup_reset(struct kernfs_open_file
*of
, char *buf
,
3424 size_t nbytes
, loff_t off
)
3426 struct mem_cgroup
*memcg
= mem_cgroup_from_css(of_css(of
));
3427 struct page_counter
*counter
;
3429 switch (MEMFILE_TYPE(of_cft(of
)->private)) {
3431 counter
= &memcg
->memory
;
3434 counter
= &memcg
->memsw
;
3437 counter
= &memcg
->kmem
;
3443 switch (MEMFILE_ATTR(of_cft(of
)->private)) {
3445 page_counter_reset_watermark(counter
);
3448 counter
->failcnt
= 0;
3457 static u64
mem_cgroup_move_charge_read(struct cgroup_subsys_state
*css
,
3460 return mem_cgroup_from_css(css
)->move_charge_at_immigrate
;
3464 static int mem_cgroup_move_charge_write(struct cgroup_subsys_state
*css
,
3465 struct cftype
*cft
, u64 val
)
3467 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
3469 if (val
>= (1 << NR_MOVE_TYPE
))
3473 * No kind of locking is needed in here, because ->can_attach() will
3474 * check this value once in the beginning of the process, and then carry
3475 * on with stale data. This means that changes to this value will only
3476 * affect task migrations starting after the change.
3478 memcg
->move_charge_at_immigrate
= val
;
3482 static int mem_cgroup_move_charge_write(struct cgroup_subsys_state
*css
,
3483 struct cftype
*cft
, u64 val
)
3490 static int memcg_numa_stat_show(struct seq_file
*m
, void *v
)
3494 unsigned int lru_mask
;
3497 static const struct numa_stat stats
[] = {
3498 { "total", LRU_ALL
},
3499 { "file", LRU_ALL_FILE
},
3500 { "anon", LRU_ALL_ANON
},
3501 { "unevictable", BIT(LRU_UNEVICTABLE
) },
3503 const struct numa_stat
*stat
;
3506 struct mem_cgroup
*memcg
= mem_cgroup_from_css(seq_css(m
));
3508 for (stat
= stats
; stat
< stats
+ ARRAY_SIZE(stats
); stat
++) {
3509 nr
= mem_cgroup_nr_lru_pages(memcg
, stat
->lru_mask
);
3510 seq_printf(m
, "%s=%lu", stat
->name
, nr
);
3511 for_each_node_state(nid
, N_MEMORY
) {
3512 nr
= mem_cgroup_node_nr_lru_pages(memcg
, nid
,
3514 seq_printf(m
, " N%d=%lu", nid
, nr
);
3519 for (stat
= stats
; stat
< stats
+ ARRAY_SIZE(stats
); stat
++) {
3520 struct mem_cgroup
*iter
;
3523 for_each_mem_cgroup_tree(iter
, memcg
)
3524 nr
+= mem_cgroup_nr_lru_pages(iter
, stat
->lru_mask
);
3525 seq_printf(m
, "hierarchical_%s=%lu", stat
->name
, nr
);
3526 for_each_node_state(nid
, N_MEMORY
) {
3528 for_each_mem_cgroup_tree(iter
, memcg
)
3529 nr
+= mem_cgroup_node_nr_lru_pages(
3530 iter
, nid
, stat
->lru_mask
);
3531 seq_printf(m
, " N%d=%lu", nid
, nr
);
3538 #endif /* CONFIG_NUMA */
3540 static int memcg_stat_show(struct seq_file
*m
, void *v
)
3542 struct mem_cgroup
*memcg
= mem_cgroup_from_css(seq_css(m
));
3543 unsigned long memory
, memsw
;
3544 struct mem_cgroup
*mi
;
3547 BUILD_BUG_ON(ARRAY_SIZE(mem_cgroup_lru_names
) != NR_LRU_LISTS
);
3549 for (i
= 0; i
< MEM_CGROUP_STAT_NSTATS
; i
++) {
3550 if (i
== MEM_CGROUP_STAT_SWAP
&& !do_swap_account
)
3552 seq_printf(m
, "%s %ld\n", mem_cgroup_stat_names
[i
],
3553 mem_cgroup_read_stat(memcg
, i
) * PAGE_SIZE
);
3556 for (i
= 0; i
< MEM_CGROUP_EVENTS_NSTATS
; i
++)
3557 seq_printf(m
, "%s %lu\n", mem_cgroup_events_names
[i
],
3558 mem_cgroup_read_events(memcg
, i
));
3560 for (i
= 0; i
< NR_LRU_LISTS
; i
++)
3561 seq_printf(m
, "%s %lu\n", mem_cgroup_lru_names
[i
],
3562 mem_cgroup_nr_lru_pages(memcg
, BIT(i
)) * PAGE_SIZE
);
3564 /* Hierarchical information */
3565 memory
= memsw
= PAGE_COUNTER_MAX
;
3566 for (mi
= memcg
; mi
; mi
= parent_mem_cgroup(mi
)) {
3567 memory
= min(memory
, mi
->memory
.limit
);
3568 memsw
= min(memsw
, mi
->memsw
.limit
);
3570 seq_printf(m
, "hierarchical_memory_limit %llu\n",
3571 (u64
)memory
* PAGE_SIZE
);
3572 if (do_swap_account
)
3573 seq_printf(m
, "hierarchical_memsw_limit %llu\n",
3574 (u64
)memsw
* PAGE_SIZE
);
3576 for (i
= 0; i
< MEM_CGROUP_STAT_NSTATS
; i
++) {
3579 if (i
== MEM_CGROUP_STAT_SWAP
&& !do_swap_account
)
3581 for_each_mem_cgroup_tree(mi
, memcg
)
3582 val
+= mem_cgroup_read_stat(mi
, i
) * PAGE_SIZE
;
3583 seq_printf(m
, "total_%s %lld\n", mem_cgroup_stat_names
[i
], val
);
3586 for (i
= 0; i
< MEM_CGROUP_EVENTS_NSTATS
; i
++) {
3587 unsigned long long val
= 0;
3589 for_each_mem_cgroup_tree(mi
, memcg
)
3590 val
+= mem_cgroup_read_events(mi
, i
);
3591 seq_printf(m
, "total_%s %llu\n",
3592 mem_cgroup_events_names
[i
], val
);
3595 for (i
= 0; i
< NR_LRU_LISTS
; i
++) {
3596 unsigned long long val
= 0;
3598 for_each_mem_cgroup_tree(mi
, memcg
)
3599 val
+= mem_cgroup_nr_lru_pages(mi
, BIT(i
)) * PAGE_SIZE
;
3600 seq_printf(m
, "total_%s %llu\n", mem_cgroup_lru_names
[i
], val
);
3603 #ifdef CONFIG_DEBUG_VM
3606 struct mem_cgroup_per_zone
*mz
;
3607 struct zone_reclaim_stat
*rstat
;
3608 unsigned long recent_rotated
[2] = {0, 0};
3609 unsigned long recent_scanned
[2] = {0, 0};
3611 for_each_online_node(nid
)
3612 for (zid
= 0; zid
< MAX_NR_ZONES
; zid
++) {
3613 mz
= &memcg
->nodeinfo
[nid
]->zoneinfo
[zid
];
3614 rstat
= &mz
->lruvec
.reclaim_stat
;
3616 recent_rotated
[0] += rstat
->recent_rotated
[0];
3617 recent_rotated
[1] += rstat
->recent_rotated
[1];
3618 recent_scanned
[0] += rstat
->recent_scanned
[0];
3619 recent_scanned
[1] += rstat
->recent_scanned
[1];
3621 seq_printf(m
, "recent_rotated_anon %lu\n", recent_rotated
[0]);
3622 seq_printf(m
, "recent_rotated_file %lu\n", recent_rotated
[1]);
3623 seq_printf(m
, "recent_scanned_anon %lu\n", recent_scanned
[0]);
3624 seq_printf(m
, "recent_scanned_file %lu\n", recent_scanned
[1]);
3631 static u64
mem_cgroup_swappiness_read(struct cgroup_subsys_state
*css
,
3634 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
3636 return mem_cgroup_swappiness(memcg
);
3639 static int mem_cgroup_swappiness_write(struct cgroup_subsys_state
*css
,
3640 struct cftype
*cft
, u64 val
)
3642 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
3648 memcg
->swappiness
= val
;
3650 vm_swappiness
= val
;
3655 static void __mem_cgroup_threshold(struct mem_cgroup
*memcg
, bool swap
)
3657 struct mem_cgroup_threshold_ary
*t
;
3658 unsigned long usage
;
3663 t
= rcu_dereference(memcg
->thresholds
.primary
);
3665 t
= rcu_dereference(memcg
->memsw_thresholds
.primary
);
3670 usage
= mem_cgroup_usage(memcg
, swap
);
3673 * current_threshold points to threshold just below or equal to usage.
3674 * If it's not true, a threshold was crossed after last
3675 * call of __mem_cgroup_threshold().
3677 i
= t
->current_threshold
;
3680 * Iterate backward over array of thresholds starting from
3681 * current_threshold and check if a threshold is crossed.
3682 * If none of thresholds below usage is crossed, we read
3683 * only one element of the array here.
3685 for (; i
>= 0 && unlikely(t
->entries
[i
].threshold
> usage
); i
--)
3686 eventfd_signal(t
->entries
[i
].eventfd
, 1);
3688 /* i = current_threshold + 1 */
3692 * Iterate forward over array of thresholds starting from
3693 * current_threshold+1 and check if a threshold is crossed.
3694 * If none of thresholds above usage is crossed, we read
3695 * only one element of the array here.
3697 for (; i
< t
->size
&& unlikely(t
->entries
[i
].threshold
<= usage
); i
++)
3698 eventfd_signal(t
->entries
[i
].eventfd
, 1);
3700 /* Update current_threshold */
3701 t
->current_threshold
= i
- 1;
3706 static void mem_cgroup_threshold(struct mem_cgroup
*memcg
)
3709 __mem_cgroup_threshold(memcg
, false);
3710 if (do_swap_account
)
3711 __mem_cgroup_threshold(memcg
, true);
3713 memcg
= parent_mem_cgroup(memcg
);
3717 static int compare_thresholds(const void *a
, const void *b
)
3719 const struct mem_cgroup_threshold
*_a
= a
;
3720 const struct mem_cgroup_threshold
*_b
= b
;
3722 if (_a
->threshold
> _b
->threshold
)
3725 if (_a
->threshold
< _b
->threshold
)
3731 static int mem_cgroup_oom_notify_cb(struct mem_cgroup
*memcg
)
3733 struct mem_cgroup_eventfd_list
*ev
;
3735 spin_lock(&memcg_oom_lock
);
3737 list_for_each_entry(ev
, &memcg
->oom_notify
, list
)
3738 eventfd_signal(ev
->eventfd
, 1);
3740 spin_unlock(&memcg_oom_lock
);
3744 static void mem_cgroup_oom_notify(struct mem_cgroup
*memcg
)
3746 struct mem_cgroup
*iter
;
3748 for_each_mem_cgroup_tree(iter
, memcg
)
3749 mem_cgroup_oom_notify_cb(iter
);
3752 static int __mem_cgroup_usage_register_event(struct mem_cgroup
*memcg
,
3753 struct eventfd_ctx
*eventfd
, const char *args
, enum res_type type
)
3755 struct mem_cgroup_thresholds
*thresholds
;
3756 struct mem_cgroup_threshold_ary
*new;
3757 unsigned long threshold
;
3758 unsigned long usage
;
3761 ret
= page_counter_memparse(args
, &threshold
);
3765 mutex_lock(&memcg
->thresholds_lock
);
3768 thresholds
= &memcg
->thresholds
;
3769 usage
= mem_cgroup_usage(memcg
, false);
3770 } else if (type
== _MEMSWAP
) {
3771 thresholds
= &memcg
->memsw_thresholds
;
3772 usage
= mem_cgroup_usage(memcg
, true);
3776 /* Check if a threshold crossed before adding a new one */
3777 if (thresholds
->primary
)
3778 __mem_cgroup_threshold(memcg
, type
== _MEMSWAP
);
3780 size
= thresholds
->primary
? thresholds
->primary
->size
+ 1 : 1;
3782 /* Allocate memory for new array of thresholds */
3783 new = kmalloc(sizeof(*new) + size
* sizeof(struct mem_cgroup_threshold
),
3791 /* Copy thresholds (if any) to new array */
3792 if (thresholds
->primary
) {
3793 memcpy(new->entries
, thresholds
->primary
->entries
, (size
- 1) *
3794 sizeof(struct mem_cgroup_threshold
));
3797 /* Add new threshold */
3798 new->entries
[size
- 1].eventfd
= eventfd
;
3799 new->entries
[size
- 1].threshold
= threshold
;
3801 /* Sort thresholds. Registering of new threshold isn't time-critical */
3802 sort(new->entries
, size
, sizeof(struct mem_cgroup_threshold
),
3803 compare_thresholds
, NULL
);
3805 /* Find current threshold */
3806 new->current_threshold
= -1;
3807 for (i
= 0; i
< size
; i
++) {
3808 if (new->entries
[i
].threshold
<= usage
) {
3810 * new->current_threshold will not be used until
3811 * rcu_assign_pointer(), so it's safe to increment
3814 ++new->current_threshold
;
3819 /* Free old spare buffer and save old primary buffer as spare */
3820 kfree(thresholds
->spare
);
3821 thresholds
->spare
= thresholds
->primary
;
3823 rcu_assign_pointer(thresholds
->primary
, new);
3825 /* To be sure that nobody uses thresholds */
3829 mutex_unlock(&memcg
->thresholds_lock
);
3834 static int mem_cgroup_usage_register_event(struct mem_cgroup
*memcg
,
3835 struct eventfd_ctx
*eventfd
, const char *args
)
3837 return __mem_cgroup_usage_register_event(memcg
, eventfd
, args
, _MEM
);
3840 static int memsw_cgroup_usage_register_event(struct mem_cgroup
*memcg
,
3841 struct eventfd_ctx
*eventfd
, const char *args
)
3843 return __mem_cgroup_usage_register_event(memcg
, eventfd
, args
, _MEMSWAP
);
3846 static void __mem_cgroup_usage_unregister_event(struct mem_cgroup
*memcg
,
3847 struct eventfd_ctx
*eventfd
, enum res_type type
)
3849 struct mem_cgroup_thresholds
*thresholds
;
3850 struct mem_cgroup_threshold_ary
*new;
3851 unsigned long usage
;
3854 mutex_lock(&memcg
->thresholds_lock
);
3857 thresholds
= &memcg
->thresholds
;
3858 usage
= mem_cgroup_usage(memcg
, false);
3859 } else if (type
== _MEMSWAP
) {
3860 thresholds
= &memcg
->memsw_thresholds
;
3861 usage
= mem_cgroup_usage(memcg
, true);
3865 if (!thresholds
->primary
)
3868 /* Check if a threshold crossed before removing */
3869 __mem_cgroup_threshold(memcg
, type
== _MEMSWAP
);
3871 /* Calculate new number of threshold */
3873 for (i
= 0; i
< thresholds
->primary
->size
; i
++) {
3874 if (thresholds
->primary
->entries
[i
].eventfd
!= eventfd
)
3878 new = thresholds
->spare
;
3880 /* Set thresholds array to NULL if we don't have thresholds */
3889 /* Copy thresholds and find current threshold */
3890 new->current_threshold
= -1;
3891 for (i
= 0, j
= 0; i
< thresholds
->primary
->size
; i
++) {
3892 if (thresholds
->primary
->entries
[i
].eventfd
== eventfd
)
3895 new->entries
[j
] = thresholds
->primary
->entries
[i
];
3896 if (new->entries
[j
].threshold
<= usage
) {
3898 * new->current_threshold will not be used
3899 * until rcu_assign_pointer(), so it's safe to increment
3902 ++new->current_threshold
;
3908 /* Swap primary and spare array */
3909 thresholds
->spare
= thresholds
->primary
;
3910 /* If all events are unregistered, free the spare array */
3912 kfree(thresholds
->spare
);
3913 thresholds
->spare
= NULL
;
3916 rcu_assign_pointer(thresholds
->primary
, new);
3918 /* To be sure that nobody uses thresholds */
3921 mutex_unlock(&memcg
->thresholds_lock
);
3924 static void mem_cgroup_usage_unregister_event(struct mem_cgroup
*memcg
,
3925 struct eventfd_ctx
*eventfd
)
3927 return __mem_cgroup_usage_unregister_event(memcg
, eventfd
, _MEM
);
3930 static void memsw_cgroup_usage_unregister_event(struct mem_cgroup
*memcg
,
3931 struct eventfd_ctx
*eventfd
)
3933 return __mem_cgroup_usage_unregister_event(memcg
, eventfd
, _MEMSWAP
);
3936 static int mem_cgroup_oom_register_event(struct mem_cgroup
*memcg
,
3937 struct eventfd_ctx
*eventfd
, const char *args
)
3939 struct mem_cgroup_eventfd_list
*event
;
3941 event
= kmalloc(sizeof(*event
), GFP_KERNEL
);
3945 spin_lock(&memcg_oom_lock
);
3947 event
->eventfd
= eventfd
;
3948 list_add(&event
->list
, &memcg
->oom_notify
);
3950 /* already in OOM ? */
3951 if (atomic_read(&memcg
->under_oom
))
3952 eventfd_signal(eventfd
, 1);
3953 spin_unlock(&memcg_oom_lock
);
3958 static void mem_cgroup_oom_unregister_event(struct mem_cgroup
*memcg
,
3959 struct eventfd_ctx
*eventfd
)
3961 struct mem_cgroup_eventfd_list
*ev
, *tmp
;
3963 spin_lock(&memcg_oom_lock
);
3965 list_for_each_entry_safe(ev
, tmp
, &memcg
->oom_notify
, list
) {
3966 if (ev
->eventfd
== eventfd
) {
3967 list_del(&ev
->list
);
3972 spin_unlock(&memcg_oom_lock
);
3975 static int mem_cgroup_oom_control_read(struct seq_file
*sf
, void *v
)
3977 struct mem_cgroup
*memcg
= mem_cgroup_from_css(seq_css(sf
));
3979 seq_printf(sf
, "oom_kill_disable %d\n", memcg
->oom_kill_disable
);
3980 seq_printf(sf
, "under_oom %d\n", (bool)atomic_read(&memcg
->under_oom
));
3984 static int mem_cgroup_oom_control_write(struct cgroup_subsys_state
*css
,
3985 struct cftype
*cft
, u64 val
)
3987 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
3989 /* cannot set to root cgroup and only 0 and 1 are allowed */
3990 if (!css
->parent
|| !((val
== 0) || (val
== 1)))
3993 memcg
->oom_kill_disable
= val
;
3995 memcg_oom_recover(memcg
);
4000 #ifdef CONFIG_MEMCG_KMEM
4001 static int memcg_init_kmem(struct mem_cgroup
*memcg
, struct cgroup_subsys
*ss
)
4005 ret
= memcg_propagate_kmem(memcg
);
4009 return mem_cgroup_sockets_init(memcg
, ss
);
4012 static void memcg_destroy_kmem(struct mem_cgroup
*memcg
)
4014 memcg_destroy_kmem_caches(memcg
);
4015 mem_cgroup_sockets_destroy(memcg
);
4018 static int memcg_init_kmem(struct mem_cgroup
*memcg
, struct cgroup_subsys
*ss
)
4023 static void memcg_destroy_kmem(struct mem_cgroup
*memcg
)
4029 * DO NOT USE IN NEW FILES.
4031 * "cgroup.event_control" implementation.
4033 * This is way over-engineered. It tries to support fully configurable
4034 * events for each user. Such level of flexibility is completely
4035 * unnecessary especially in the light of the planned unified hierarchy.
4037 * Please deprecate this and replace with something simpler if at all
4042 * Unregister event and free resources.
4044 * Gets called from workqueue.
4046 static void memcg_event_remove(struct work_struct
*work
)
4048 struct mem_cgroup_event
*event
=
4049 container_of(work
, struct mem_cgroup_event
, remove
);
4050 struct mem_cgroup
*memcg
= event
->memcg
;
4052 remove_wait_queue(event
->wqh
, &event
->wait
);
4054 event
->unregister_event(memcg
, event
->eventfd
);
4056 /* Notify userspace the event is going away. */
4057 eventfd_signal(event
->eventfd
, 1);
4059 eventfd_ctx_put(event
->eventfd
);
4061 css_put(&memcg
->css
);
4065 * Gets called on POLLHUP on eventfd when user closes it.
4067 * Called with wqh->lock held and interrupts disabled.
4069 static int memcg_event_wake(wait_queue_t
*wait
, unsigned mode
,
4070 int sync
, void *key
)
4072 struct mem_cgroup_event
*event
=
4073 container_of(wait
, struct mem_cgroup_event
, wait
);
4074 struct mem_cgroup
*memcg
= event
->memcg
;
4075 unsigned long flags
= (unsigned long)key
;
4077 if (flags
& POLLHUP
) {
4079 * If the event has been detached at cgroup removal, we
4080 * can simply return knowing the other side will cleanup
4083 * We can't race against event freeing since the other
4084 * side will require wqh->lock via remove_wait_queue(),
4087 spin_lock(&memcg
->event_list_lock
);
4088 if (!list_empty(&event
->list
)) {
4089 list_del_init(&event
->list
);
4091 * We are in atomic context, but cgroup_event_remove()
4092 * may sleep, so we have to call it in workqueue.
4094 schedule_work(&event
->remove
);
4096 spin_unlock(&memcg
->event_list_lock
);
4102 static void memcg_event_ptable_queue_proc(struct file
*file
,
4103 wait_queue_head_t
*wqh
, poll_table
*pt
)
4105 struct mem_cgroup_event
*event
=
4106 container_of(pt
, struct mem_cgroup_event
, pt
);
4109 add_wait_queue(wqh
, &event
->wait
);
4113 * DO NOT USE IN NEW FILES.
4115 * Parse input and register new cgroup event handler.
4117 * Input must be in format '<event_fd> <control_fd> <args>'.
4118 * Interpretation of args is defined by control file implementation.
4120 static ssize_t
memcg_write_event_control(struct kernfs_open_file
*of
,
4121 char *buf
, size_t nbytes
, loff_t off
)
4123 struct cgroup_subsys_state
*css
= of_css(of
);
4124 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
4125 struct mem_cgroup_event
*event
;
4126 struct cgroup_subsys_state
*cfile_css
;
4127 unsigned int efd
, cfd
;
4134 buf
= strstrip(buf
);
4136 efd
= simple_strtoul(buf
, &endp
, 10);
4141 cfd
= simple_strtoul(buf
, &endp
, 10);
4142 if ((*endp
!= ' ') && (*endp
!= '\0'))
4146 event
= kzalloc(sizeof(*event
), GFP_KERNEL
);
4150 event
->memcg
= memcg
;
4151 INIT_LIST_HEAD(&event
->list
);
4152 init_poll_funcptr(&event
->pt
, memcg_event_ptable_queue_proc
);
4153 init_waitqueue_func_entry(&event
->wait
, memcg_event_wake
);
4154 INIT_WORK(&event
->remove
, memcg_event_remove
);
4162 event
->eventfd
= eventfd_ctx_fileget(efile
.file
);
4163 if (IS_ERR(event
->eventfd
)) {
4164 ret
= PTR_ERR(event
->eventfd
);
4171 goto out_put_eventfd
;
4174 /* the process need read permission on control file */
4175 /* AV: shouldn't we check that it's been opened for read instead? */
4176 ret
= inode_permission(file_inode(cfile
.file
), MAY_READ
);
4181 * Determine the event callbacks and set them in @event. This used
4182 * to be done via struct cftype but cgroup core no longer knows
4183 * about these events. The following is crude but the whole thing
4184 * is for compatibility anyway.
4186 * DO NOT ADD NEW FILES.
4188 name
= cfile
.file
->f_path
.dentry
->d_name
.name
;
4190 if (!strcmp(name
, "memory.usage_in_bytes")) {
4191 event
->register_event
= mem_cgroup_usage_register_event
;
4192 event
->unregister_event
= mem_cgroup_usage_unregister_event
;
4193 } else if (!strcmp(name
, "memory.oom_control")) {
4194 event
->register_event
= mem_cgroup_oom_register_event
;
4195 event
->unregister_event
= mem_cgroup_oom_unregister_event
;
4196 } else if (!strcmp(name
, "memory.pressure_level")) {
4197 event
->register_event
= vmpressure_register_event
;
4198 event
->unregister_event
= vmpressure_unregister_event
;
4199 } else if (!strcmp(name
, "memory.memsw.usage_in_bytes")) {
4200 event
->register_event
= memsw_cgroup_usage_register_event
;
4201 event
->unregister_event
= memsw_cgroup_usage_unregister_event
;
4208 * Verify @cfile should belong to @css. Also, remaining events are
4209 * automatically removed on cgroup destruction but the removal is
4210 * asynchronous, so take an extra ref on @css.
4212 cfile_css
= css_tryget_online_from_dir(cfile
.file
->f_path
.dentry
->d_parent
,
4213 &memory_cgrp_subsys
);
4215 if (IS_ERR(cfile_css
))
4217 if (cfile_css
!= css
) {
4222 ret
= event
->register_event(memcg
, event
->eventfd
, buf
);
4226 efile
.file
->f_op
->poll(efile
.file
, &event
->pt
);
4228 spin_lock(&memcg
->event_list_lock
);
4229 list_add(&event
->list
, &memcg
->event_list
);
4230 spin_unlock(&memcg
->event_list_lock
);
4242 eventfd_ctx_put(event
->eventfd
);
4251 static struct cftype mem_cgroup_files
[] = {
4253 .name
= "usage_in_bytes",
4254 .private = MEMFILE_PRIVATE(_MEM
, RES_USAGE
),
4255 .read_u64
= mem_cgroup_read_u64
,
4258 .name
= "max_usage_in_bytes",
4259 .private = MEMFILE_PRIVATE(_MEM
, RES_MAX_USAGE
),
4260 .write
= mem_cgroup_reset
,
4261 .read_u64
= mem_cgroup_read_u64
,
4264 .name
= "limit_in_bytes",
4265 .private = MEMFILE_PRIVATE(_MEM
, RES_LIMIT
),
4266 .write
= mem_cgroup_write
,
4267 .read_u64
= mem_cgroup_read_u64
,
4270 .name
= "soft_limit_in_bytes",
4271 .private = MEMFILE_PRIVATE(_MEM
, RES_SOFT_LIMIT
),
4272 .write
= mem_cgroup_write
,
4273 .read_u64
= mem_cgroup_read_u64
,
4277 .private = MEMFILE_PRIVATE(_MEM
, RES_FAILCNT
),
4278 .write
= mem_cgroup_reset
,
4279 .read_u64
= mem_cgroup_read_u64
,
4283 .seq_show
= memcg_stat_show
,
4286 .name
= "force_empty",
4287 .write
= mem_cgroup_force_empty_write
,
4290 .name
= "use_hierarchy",
4291 .write_u64
= mem_cgroup_hierarchy_write
,
4292 .read_u64
= mem_cgroup_hierarchy_read
,
4295 .name
= "cgroup.event_control", /* XXX: for compat */
4296 .write
= memcg_write_event_control
,
4297 .flags
= CFTYPE_NO_PREFIX
,
4301 .name
= "swappiness",
4302 .read_u64
= mem_cgroup_swappiness_read
,
4303 .write_u64
= mem_cgroup_swappiness_write
,
4306 .name
= "move_charge_at_immigrate",
4307 .read_u64
= mem_cgroup_move_charge_read
,
4308 .write_u64
= mem_cgroup_move_charge_write
,
4311 .name
= "oom_control",
4312 .seq_show
= mem_cgroup_oom_control_read
,
4313 .write_u64
= mem_cgroup_oom_control_write
,
4314 .private = MEMFILE_PRIVATE(_OOM_TYPE
, OOM_CONTROL
),
4317 .name
= "pressure_level",
4321 .name
= "numa_stat",
4322 .seq_show
= memcg_numa_stat_show
,
4325 #ifdef CONFIG_MEMCG_KMEM
4327 .name
= "kmem.limit_in_bytes",
4328 .private = MEMFILE_PRIVATE(_KMEM
, RES_LIMIT
),
4329 .write
= mem_cgroup_write
,
4330 .read_u64
= mem_cgroup_read_u64
,
4333 .name
= "kmem.usage_in_bytes",
4334 .private = MEMFILE_PRIVATE(_KMEM
, RES_USAGE
),
4335 .read_u64
= mem_cgroup_read_u64
,
4338 .name
= "kmem.failcnt",
4339 .private = MEMFILE_PRIVATE(_KMEM
, RES_FAILCNT
),
4340 .write
= mem_cgroup_reset
,
4341 .read_u64
= mem_cgroup_read_u64
,
4344 .name
= "kmem.max_usage_in_bytes",
4345 .private = MEMFILE_PRIVATE(_KMEM
, RES_MAX_USAGE
),
4346 .write
= mem_cgroup_reset
,
4347 .read_u64
= mem_cgroup_read_u64
,
4349 #ifdef CONFIG_SLABINFO
4351 .name
= "kmem.slabinfo",
4352 .seq_start
= slab_start
,
4353 .seq_next
= slab_next
,
4354 .seq_stop
= slab_stop
,
4355 .seq_show
= memcg_slab_show
,
4359 { }, /* terminate */
4362 #ifdef CONFIG_MEMCG_SWAP
4363 static struct cftype memsw_cgroup_files
[] = {
4365 .name
= "memsw.usage_in_bytes",
4366 .private = MEMFILE_PRIVATE(_MEMSWAP
, RES_USAGE
),
4367 .read_u64
= mem_cgroup_read_u64
,
4370 .name
= "memsw.max_usage_in_bytes",
4371 .private = MEMFILE_PRIVATE(_MEMSWAP
, RES_MAX_USAGE
),
4372 .write
= mem_cgroup_reset
,
4373 .read_u64
= mem_cgroup_read_u64
,
4376 .name
= "memsw.limit_in_bytes",
4377 .private = MEMFILE_PRIVATE(_MEMSWAP
, RES_LIMIT
),
4378 .write
= mem_cgroup_write
,
4379 .read_u64
= mem_cgroup_read_u64
,
4382 .name
= "memsw.failcnt",
4383 .private = MEMFILE_PRIVATE(_MEMSWAP
, RES_FAILCNT
),
4384 .write
= mem_cgroup_reset
,
4385 .read_u64
= mem_cgroup_read_u64
,
4387 { }, /* terminate */
4390 static int alloc_mem_cgroup_per_zone_info(struct mem_cgroup
*memcg
, int node
)
4392 struct mem_cgroup_per_node
*pn
;
4393 struct mem_cgroup_per_zone
*mz
;
4394 int zone
, tmp
= node
;
4396 * This routine is called against possible nodes.
4397 * But it's BUG to call kmalloc() against offline node.
4399 * TODO: this routine can waste much memory for nodes which will
4400 * never be onlined. It's better to use memory hotplug callback
4403 if (!node_state(node
, N_NORMAL_MEMORY
))
4405 pn
= kzalloc_node(sizeof(*pn
), GFP_KERNEL
, tmp
);
4409 for (zone
= 0; zone
< MAX_NR_ZONES
; zone
++) {
4410 mz
= &pn
->zoneinfo
[zone
];
4411 lruvec_init(&mz
->lruvec
);
4412 mz
->usage_in_excess
= 0;
4413 mz
->on_tree
= false;
4416 memcg
->nodeinfo
[node
] = pn
;
4420 static void free_mem_cgroup_per_zone_info(struct mem_cgroup
*memcg
, int node
)
4422 kfree(memcg
->nodeinfo
[node
]);
4425 static struct mem_cgroup
*mem_cgroup_alloc(void)
4427 struct mem_cgroup
*memcg
;
4430 size
= sizeof(struct mem_cgroup
);
4431 size
+= nr_node_ids
* sizeof(struct mem_cgroup_per_node
*);
4433 memcg
= kzalloc(size
, GFP_KERNEL
);
4437 memcg
->stat
= alloc_percpu(struct mem_cgroup_stat_cpu
);
4440 spin_lock_init(&memcg
->pcp_counter_lock
);
4449 * At destroying mem_cgroup, references from swap_cgroup can remain.
4450 * (scanning all at force_empty is too costly...)
4452 * Instead of clearing all references at force_empty, we remember
4453 * the number of reference from swap_cgroup and free mem_cgroup when
4454 * it goes down to 0.
4456 * Removal of cgroup itself succeeds regardless of refs from swap.
4459 static void __mem_cgroup_free(struct mem_cgroup
*memcg
)
4463 mem_cgroup_remove_from_trees(memcg
);
4466 free_mem_cgroup_per_zone_info(memcg
, node
);
4468 free_percpu(memcg
->stat
);
4470 disarm_static_keys(memcg
);
4475 * Returns the parent mem_cgroup in memcgroup hierarchy with hierarchy enabled.
4477 struct mem_cgroup
*parent_mem_cgroup(struct mem_cgroup
*memcg
)
4479 if (!memcg
->memory
.parent
)
4481 return mem_cgroup_from_counter(memcg
->memory
.parent
, memory
);
4483 EXPORT_SYMBOL(parent_mem_cgroup
);
4485 static void __init
mem_cgroup_soft_limit_tree_init(void)
4487 struct mem_cgroup_tree_per_node
*rtpn
;
4488 struct mem_cgroup_tree_per_zone
*rtpz
;
4489 int tmp
, node
, zone
;
4491 for_each_node(node
) {
4493 if (!node_state(node
, N_NORMAL_MEMORY
))
4495 rtpn
= kzalloc_node(sizeof(*rtpn
), GFP_KERNEL
, tmp
);
4498 soft_limit_tree
.rb_tree_per_node
[node
] = rtpn
;
4500 for (zone
= 0; zone
< MAX_NR_ZONES
; zone
++) {
4501 rtpz
= &rtpn
->rb_tree_per_zone
[zone
];
4502 rtpz
->rb_root
= RB_ROOT
;
4503 spin_lock_init(&rtpz
->lock
);
4508 static struct cgroup_subsys_state
* __ref
4509 mem_cgroup_css_alloc(struct cgroup_subsys_state
*parent_css
)
4511 struct mem_cgroup
*memcg
;
4512 long error
= -ENOMEM
;
4515 memcg
= mem_cgroup_alloc();
4517 return ERR_PTR(error
);
4520 if (alloc_mem_cgroup_per_zone_info(memcg
, node
))
4524 if (parent_css
== NULL
) {
4525 root_mem_cgroup
= memcg
;
4526 page_counter_init(&memcg
->memory
, NULL
);
4527 memcg
->soft_limit
= PAGE_COUNTER_MAX
;
4528 page_counter_init(&memcg
->memsw
, NULL
);
4529 page_counter_init(&memcg
->kmem
, NULL
);
4532 memcg
->last_scanned_node
= MAX_NUMNODES
;
4533 INIT_LIST_HEAD(&memcg
->oom_notify
);
4534 memcg
->move_charge_at_immigrate
= 0;
4535 mutex_init(&memcg
->thresholds_lock
);
4536 spin_lock_init(&memcg
->move_lock
);
4537 vmpressure_init(&memcg
->vmpressure
);
4538 INIT_LIST_HEAD(&memcg
->event_list
);
4539 spin_lock_init(&memcg
->event_list_lock
);
4540 #ifdef CONFIG_MEMCG_KMEM
4541 memcg
->kmemcg_id
= -1;
4547 __mem_cgroup_free(memcg
);
4548 return ERR_PTR(error
);
4552 mem_cgroup_css_online(struct cgroup_subsys_state
*css
)
4554 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
4555 struct mem_cgroup
*parent
= mem_cgroup_from_css(css
->parent
);
4558 if (css
->id
> MEM_CGROUP_ID_MAX
)
4564 mutex_lock(&memcg_create_mutex
);
4566 memcg
->use_hierarchy
= parent
->use_hierarchy
;
4567 memcg
->oom_kill_disable
= parent
->oom_kill_disable
;
4568 memcg
->swappiness
= mem_cgroup_swappiness(parent
);
4570 if (parent
->use_hierarchy
) {
4571 page_counter_init(&memcg
->memory
, &parent
->memory
);
4572 memcg
->soft_limit
= PAGE_COUNTER_MAX
;
4573 page_counter_init(&memcg
->memsw
, &parent
->memsw
);
4574 page_counter_init(&memcg
->kmem
, &parent
->kmem
);
4577 * No need to take a reference to the parent because cgroup
4578 * core guarantees its existence.
4581 page_counter_init(&memcg
->memory
, NULL
);
4582 memcg
->soft_limit
= PAGE_COUNTER_MAX
;
4583 page_counter_init(&memcg
->memsw
, NULL
);
4584 page_counter_init(&memcg
->kmem
, NULL
);
4586 * Deeper hierachy with use_hierarchy == false doesn't make
4587 * much sense so let cgroup subsystem know about this
4588 * unfortunate state in our controller.
4590 if (parent
!= root_mem_cgroup
)
4591 memory_cgrp_subsys
.broken_hierarchy
= true;
4593 mutex_unlock(&memcg_create_mutex
);
4595 ret
= memcg_init_kmem(memcg
, &memory_cgrp_subsys
);
4600 * Make sure the memcg is initialized: mem_cgroup_iter()
4601 * orders reading memcg->initialized against its callers
4602 * reading the memcg members.
4604 smp_store_release(&memcg
->initialized
, 1);
4609 static void mem_cgroup_css_offline(struct cgroup_subsys_state
*css
)
4611 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
4612 struct mem_cgroup_event
*event
, *tmp
;
4615 * Unregister events and notify userspace.
4616 * Notify userspace about cgroup removing only after rmdir of cgroup
4617 * directory to avoid race between userspace and kernelspace.
4619 spin_lock(&memcg
->event_list_lock
);
4620 list_for_each_entry_safe(event
, tmp
, &memcg
->event_list
, list
) {
4621 list_del_init(&event
->list
);
4622 schedule_work(&event
->remove
);
4624 spin_unlock(&memcg
->event_list_lock
);
4626 vmpressure_cleanup(&memcg
->vmpressure
);
4629 static void mem_cgroup_css_free(struct cgroup_subsys_state
*css
)
4631 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
4633 memcg_destroy_kmem(memcg
);
4634 __mem_cgroup_free(memcg
);
4638 * mem_cgroup_css_reset - reset the states of a mem_cgroup
4639 * @css: the target css
4641 * Reset the states of the mem_cgroup associated with @css. This is
4642 * invoked when the userland requests disabling on the default hierarchy
4643 * but the memcg is pinned through dependency. The memcg should stop
4644 * applying policies and should revert to the vanilla state as it may be
4645 * made visible again.
4647 * The current implementation only resets the essential configurations.
4648 * This needs to be expanded to cover all the visible parts.
4650 static void mem_cgroup_css_reset(struct cgroup_subsys_state
*css
)
4652 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
4654 mem_cgroup_resize_limit(memcg
, PAGE_COUNTER_MAX
);
4655 mem_cgroup_resize_memsw_limit(memcg
, PAGE_COUNTER_MAX
);
4656 memcg_update_kmem_limit(memcg
, PAGE_COUNTER_MAX
);
4657 memcg
->soft_limit
= PAGE_COUNTER_MAX
;
4661 /* Handlers for move charge at task migration. */
4662 static int mem_cgroup_do_precharge(unsigned long count
)
4666 /* Try a single bulk charge without reclaim first */
4667 ret
= try_charge(mc
.to
, GFP_KERNEL
& ~__GFP_WAIT
, count
);
4669 mc
.precharge
+= count
;
4672 if (ret
== -EINTR
) {
4673 cancel_charge(root_mem_cgroup
, count
);
4677 /* Try charges one by one with reclaim */
4679 ret
= try_charge(mc
.to
, GFP_KERNEL
& ~__GFP_NORETRY
, 1);
4681 * In case of failure, any residual charges against
4682 * mc.to will be dropped by mem_cgroup_clear_mc()
4683 * later on. However, cancel any charges that are
4684 * bypassed to root right away or they'll be lost.
4687 cancel_charge(root_mem_cgroup
, 1);
4697 * get_mctgt_type - get target type of moving charge
4698 * @vma: the vma the pte to be checked belongs
4699 * @addr: the address corresponding to the pte to be checked
4700 * @ptent: the pte to be checked
4701 * @target: the pointer the target page or swap ent will be stored(can be NULL)
4704 * 0(MC_TARGET_NONE): if the pte is not a target for move charge.
4705 * 1(MC_TARGET_PAGE): if the page corresponding to this pte is a target for
4706 * move charge. if @target is not NULL, the page is stored in target->page
4707 * with extra refcnt got(Callers should handle it).
4708 * 2(MC_TARGET_SWAP): if the swap entry corresponding to this pte is a
4709 * target for charge migration. if @target is not NULL, the entry is stored
4712 * Called with pte lock held.
4719 enum mc_target_type
{
4725 static struct page
*mc_handle_present_pte(struct vm_area_struct
*vma
,
4726 unsigned long addr
, pte_t ptent
)
4728 struct page
*page
= vm_normal_page(vma
, addr
, ptent
);
4730 if (!page
|| !page_mapped(page
))
4732 if (PageAnon(page
)) {
4733 /* we don't move shared anon */
4736 } else if (!move_file())
4737 /* we ignore mapcount for file pages */
4739 if (!get_page_unless_zero(page
))
4746 static struct page
*mc_handle_swap_pte(struct vm_area_struct
*vma
,
4747 unsigned long addr
, pte_t ptent
, swp_entry_t
*entry
)
4749 struct page
*page
= NULL
;
4750 swp_entry_t ent
= pte_to_swp_entry(ptent
);
4752 if (!move_anon() || non_swap_entry(ent
))
4755 * Because lookup_swap_cache() updates some statistics counter,
4756 * we call find_get_page() with swapper_space directly.
4758 page
= find_get_page(swap_address_space(ent
), ent
.val
);
4759 if (do_swap_account
)
4760 entry
->val
= ent
.val
;
4765 static struct page
*mc_handle_swap_pte(struct vm_area_struct
*vma
,
4766 unsigned long addr
, pte_t ptent
, swp_entry_t
*entry
)
4772 static struct page
*mc_handle_file_pte(struct vm_area_struct
*vma
,
4773 unsigned long addr
, pte_t ptent
, swp_entry_t
*entry
)
4775 struct page
*page
= NULL
;
4776 struct address_space
*mapping
;
4779 if (!vma
->vm_file
) /* anonymous vma */
4784 mapping
= vma
->vm_file
->f_mapping
;
4785 pgoff
= linear_page_index(vma
, addr
);
4787 /* page is moved even if it's not RSS of this task(page-faulted). */
4789 /* shmem/tmpfs may report page out on swap: account for that too. */
4790 if (shmem_mapping(mapping
)) {
4791 page
= find_get_entry(mapping
, pgoff
);
4792 if (radix_tree_exceptional_entry(page
)) {
4793 swp_entry_t swp
= radix_to_swp_entry(page
);
4794 if (do_swap_account
)
4796 page
= find_get_page(swap_address_space(swp
), swp
.val
);
4799 page
= find_get_page(mapping
, pgoff
);
4801 page
= find_get_page(mapping
, pgoff
);
4806 static enum mc_target_type
get_mctgt_type(struct vm_area_struct
*vma
,
4807 unsigned long addr
, pte_t ptent
, union mc_target
*target
)
4809 struct page
*page
= NULL
;
4810 enum mc_target_type ret
= MC_TARGET_NONE
;
4811 swp_entry_t ent
= { .val
= 0 };
4813 if (pte_present(ptent
))
4814 page
= mc_handle_present_pte(vma
, addr
, ptent
);
4815 else if (is_swap_pte(ptent
))
4816 page
= mc_handle_swap_pte(vma
, addr
, ptent
, &ent
);
4817 else if (pte_none(ptent
))
4818 page
= mc_handle_file_pte(vma
, addr
, ptent
, &ent
);
4820 if (!page
&& !ent
.val
)
4824 * Do only loose check w/o serialization.
4825 * mem_cgroup_move_account() checks the page is valid or
4826 * not under LRU exclusion.
4828 if (page
->mem_cgroup
== mc
.from
) {
4829 ret
= MC_TARGET_PAGE
;
4831 target
->page
= page
;
4833 if (!ret
|| !target
)
4836 /* There is a swap entry and a page doesn't exist or isn't charged */
4837 if (ent
.val
&& !ret
&&
4838 mem_cgroup_id(mc
.from
) == lookup_swap_cgroup_id(ent
)) {
4839 ret
= MC_TARGET_SWAP
;
4846 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
4848 * We don't consider swapping or file mapped pages because THP does not
4849 * support them for now.
4850 * Caller should make sure that pmd_trans_huge(pmd) is true.
4852 static enum mc_target_type
get_mctgt_type_thp(struct vm_area_struct
*vma
,
4853 unsigned long addr
, pmd_t pmd
, union mc_target
*target
)
4855 struct page
*page
= NULL
;
4856 enum mc_target_type ret
= MC_TARGET_NONE
;
4858 page
= pmd_page(pmd
);
4859 VM_BUG_ON_PAGE(!page
|| !PageHead(page
), page
);
4862 if (page
->mem_cgroup
== mc
.from
) {
4863 ret
= MC_TARGET_PAGE
;
4866 target
->page
= page
;
4872 static inline enum mc_target_type
get_mctgt_type_thp(struct vm_area_struct
*vma
,
4873 unsigned long addr
, pmd_t pmd
, union mc_target
*target
)
4875 return MC_TARGET_NONE
;
4879 static int mem_cgroup_count_precharge_pte_range(pmd_t
*pmd
,
4880 unsigned long addr
, unsigned long end
,
4881 struct mm_walk
*walk
)
4883 struct vm_area_struct
*vma
= walk
->private;
4887 if (pmd_trans_huge_lock(pmd
, vma
, &ptl
) == 1) {
4888 if (get_mctgt_type_thp(vma
, addr
, *pmd
, NULL
) == MC_TARGET_PAGE
)
4889 mc
.precharge
+= HPAGE_PMD_NR
;
4894 if (pmd_trans_unstable(pmd
))
4896 pte
= pte_offset_map_lock(vma
->vm_mm
, pmd
, addr
, &ptl
);
4897 for (; addr
!= end
; pte
++, addr
+= PAGE_SIZE
)
4898 if (get_mctgt_type(vma
, addr
, *pte
, NULL
))
4899 mc
.precharge
++; /* increment precharge temporarily */
4900 pte_unmap_unlock(pte
- 1, ptl
);
4906 static unsigned long mem_cgroup_count_precharge(struct mm_struct
*mm
)
4908 unsigned long precharge
;
4909 struct vm_area_struct
*vma
;
4911 down_read(&mm
->mmap_sem
);
4912 for (vma
= mm
->mmap
; vma
; vma
= vma
->vm_next
) {
4913 struct mm_walk mem_cgroup_count_precharge_walk
= {
4914 .pmd_entry
= mem_cgroup_count_precharge_pte_range
,
4918 if (is_vm_hugetlb_page(vma
))
4920 walk_page_range(vma
->vm_start
, vma
->vm_end
,
4921 &mem_cgroup_count_precharge_walk
);
4923 up_read(&mm
->mmap_sem
);
4925 precharge
= mc
.precharge
;
4931 static int mem_cgroup_precharge_mc(struct mm_struct
*mm
)
4933 unsigned long precharge
= mem_cgroup_count_precharge(mm
);
4935 VM_BUG_ON(mc
.moving_task
);
4936 mc
.moving_task
= current
;
4937 return mem_cgroup_do_precharge(precharge
);
4940 /* cancels all extra charges on mc.from and mc.to, and wakes up all waiters. */
4941 static void __mem_cgroup_clear_mc(void)
4943 struct mem_cgroup
*from
= mc
.from
;
4944 struct mem_cgroup
*to
= mc
.to
;
4946 /* we must uncharge all the leftover precharges from mc.to */
4948 cancel_charge(mc
.to
, mc
.precharge
);
4952 * we didn't uncharge from mc.from at mem_cgroup_move_account(), so
4953 * we must uncharge here.
4955 if (mc
.moved_charge
) {
4956 cancel_charge(mc
.from
, mc
.moved_charge
);
4957 mc
.moved_charge
= 0;
4959 /* we must fixup refcnts and charges */
4960 if (mc
.moved_swap
) {
4961 /* uncharge swap account from the old cgroup */
4962 if (!mem_cgroup_is_root(mc
.from
))
4963 page_counter_uncharge(&mc
.from
->memsw
, mc
.moved_swap
);
4966 * we charged both to->memory and to->memsw, so we
4967 * should uncharge to->memory.
4969 if (!mem_cgroup_is_root(mc
.to
))
4970 page_counter_uncharge(&mc
.to
->memory
, mc
.moved_swap
);
4972 css_put_many(&mc
.from
->css
, mc
.moved_swap
);
4974 /* we've already done css_get(mc.to) */
4977 memcg_oom_recover(from
);
4978 memcg_oom_recover(to
);
4979 wake_up_all(&mc
.waitq
);
4982 static void mem_cgroup_clear_mc(void)
4985 * we must clear moving_task before waking up waiters at the end of
4988 mc
.moving_task
= NULL
;
4989 __mem_cgroup_clear_mc();
4990 spin_lock(&mc
.lock
);
4993 spin_unlock(&mc
.lock
);
4996 static int mem_cgroup_can_attach(struct cgroup_subsys_state
*css
,
4997 struct cgroup_taskset
*tset
)
4999 struct task_struct
*p
= cgroup_taskset_first(tset
);
5001 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
5002 unsigned long move_charge_at_immigrate
;
5005 * We are now commited to this value whatever it is. Changes in this
5006 * tunable will only affect upcoming migrations, not the current one.
5007 * So we need to save it, and keep it going.
5009 move_charge_at_immigrate
= memcg
->move_charge_at_immigrate
;
5010 if (move_charge_at_immigrate
) {
5011 struct mm_struct
*mm
;
5012 struct mem_cgroup
*from
= mem_cgroup_from_task(p
);
5014 VM_BUG_ON(from
== memcg
);
5016 mm
= get_task_mm(p
);
5019 /* We move charges only when we move a owner of the mm */
5020 if (mm
->owner
== p
) {
5023 VM_BUG_ON(mc
.precharge
);
5024 VM_BUG_ON(mc
.moved_charge
);
5025 VM_BUG_ON(mc
.moved_swap
);
5027 spin_lock(&mc
.lock
);
5030 mc
.immigrate_flags
= move_charge_at_immigrate
;
5031 spin_unlock(&mc
.lock
);
5032 /* We set mc.moving_task later */
5034 ret
= mem_cgroup_precharge_mc(mm
);
5036 mem_cgroup_clear_mc();
5043 static void mem_cgroup_cancel_attach(struct cgroup_subsys_state
*css
,
5044 struct cgroup_taskset
*tset
)
5047 mem_cgroup_clear_mc();
5050 static int mem_cgroup_move_charge_pte_range(pmd_t
*pmd
,
5051 unsigned long addr
, unsigned long end
,
5052 struct mm_walk
*walk
)
5055 struct vm_area_struct
*vma
= walk
->private;
5058 enum mc_target_type target_type
;
5059 union mc_target target
;
5063 * We don't take compound_lock() here but no race with splitting thp
5065 * - if pmd_trans_huge_lock() returns 1, the relevant thp is not
5066 * under splitting, which means there's no concurrent thp split,
5067 * - if another thread runs into split_huge_page() just after we
5068 * entered this if-block, the thread must wait for page table lock
5069 * to be unlocked in __split_huge_page_splitting(), where the main
5070 * part of thp split is not executed yet.
5072 if (pmd_trans_huge_lock(pmd
, vma
, &ptl
) == 1) {
5073 if (mc
.precharge
< HPAGE_PMD_NR
) {
5077 target_type
= get_mctgt_type_thp(vma
, addr
, *pmd
, &target
);
5078 if (target_type
== MC_TARGET_PAGE
) {
5080 if (!isolate_lru_page(page
)) {
5081 if (!mem_cgroup_move_account(page
, HPAGE_PMD_NR
,
5083 mc
.precharge
-= HPAGE_PMD_NR
;
5084 mc
.moved_charge
+= HPAGE_PMD_NR
;
5086 putback_lru_page(page
);
5094 if (pmd_trans_unstable(pmd
))
5097 pte
= pte_offset_map_lock(vma
->vm_mm
, pmd
, addr
, &ptl
);
5098 for (; addr
!= end
; addr
+= PAGE_SIZE
) {
5099 pte_t ptent
= *(pte
++);
5105 switch (get_mctgt_type(vma
, addr
, ptent
, &target
)) {
5106 case MC_TARGET_PAGE
:
5108 if (isolate_lru_page(page
))
5110 if (!mem_cgroup_move_account(page
, 1, mc
.from
, mc
.to
)) {
5112 /* we uncharge from mc.from later. */
5115 putback_lru_page(page
);
5116 put
: /* get_mctgt_type() gets the page */
5119 case MC_TARGET_SWAP
:
5121 if (!mem_cgroup_move_swap_account(ent
, mc
.from
, mc
.to
)) {
5123 /* we fixup refcnts and charges later. */
5131 pte_unmap_unlock(pte
- 1, ptl
);
5136 * We have consumed all precharges we got in can_attach().
5137 * We try charge one by one, but don't do any additional
5138 * charges to mc.to if we have failed in charge once in attach()
5141 ret
= mem_cgroup_do_precharge(1);
5149 static void mem_cgroup_move_charge(struct mm_struct
*mm
)
5151 struct vm_area_struct
*vma
;
5153 lru_add_drain_all();
5155 * Signal mem_cgroup_begin_page_stat() to take the memcg's
5156 * move_lock while we're moving its pages to another memcg.
5157 * Then wait for already started RCU-only updates to finish.
5159 atomic_inc(&mc
.from
->moving_account
);
5162 if (unlikely(!down_read_trylock(&mm
->mmap_sem
))) {
5164 * Someone who are holding the mmap_sem might be waiting in
5165 * waitq. So we cancel all extra charges, wake up all waiters,
5166 * and retry. Because we cancel precharges, we might not be able
5167 * to move enough charges, but moving charge is a best-effort
5168 * feature anyway, so it wouldn't be a big problem.
5170 __mem_cgroup_clear_mc();
5174 for (vma
= mm
->mmap
; vma
; vma
= vma
->vm_next
) {
5176 struct mm_walk mem_cgroup_move_charge_walk
= {
5177 .pmd_entry
= mem_cgroup_move_charge_pte_range
,
5181 if (is_vm_hugetlb_page(vma
))
5183 ret
= walk_page_range(vma
->vm_start
, vma
->vm_end
,
5184 &mem_cgroup_move_charge_walk
);
5187 * means we have consumed all precharges and failed in
5188 * doing additional charge. Just abandon here.
5192 up_read(&mm
->mmap_sem
);
5193 atomic_dec(&mc
.from
->moving_account
);
5196 static void mem_cgroup_move_task(struct cgroup_subsys_state
*css
,
5197 struct cgroup_taskset
*tset
)
5199 struct task_struct
*p
= cgroup_taskset_first(tset
);
5200 struct mm_struct
*mm
= get_task_mm(p
);
5204 mem_cgroup_move_charge(mm
);
5208 mem_cgroup_clear_mc();
5210 #else /* !CONFIG_MMU */
5211 static int mem_cgroup_can_attach(struct cgroup_subsys_state
*css
,
5212 struct cgroup_taskset
*tset
)
5216 static void mem_cgroup_cancel_attach(struct cgroup_subsys_state
*css
,
5217 struct cgroup_taskset
*tset
)
5220 static void mem_cgroup_move_task(struct cgroup_subsys_state
*css
,
5221 struct cgroup_taskset
*tset
)
5227 * Cgroup retains root cgroups across [un]mount cycles making it necessary
5228 * to verify whether we're attached to the default hierarchy on each mount
5231 static void mem_cgroup_bind(struct cgroup_subsys_state
*root_css
)
5234 * use_hierarchy is forced on the default hierarchy. cgroup core
5235 * guarantees that @root doesn't have any children, so turning it
5236 * on for the root memcg is enough.
5238 if (cgroup_on_dfl(root_css
->cgroup
))
5239 mem_cgroup_from_css(root_css
)->use_hierarchy
= true;
5242 struct cgroup_subsys memory_cgrp_subsys
= {
5243 .css_alloc
= mem_cgroup_css_alloc
,
5244 .css_online
= mem_cgroup_css_online
,
5245 .css_offline
= mem_cgroup_css_offline
,
5246 .css_free
= mem_cgroup_css_free
,
5247 .css_reset
= mem_cgroup_css_reset
,
5248 .can_attach
= mem_cgroup_can_attach
,
5249 .cancel_attach
= mem_cgroup_cancel_attach
,
5250 .attach
= mem_cgroup_move_task
,
5251 .bind
= mem_cgroup_bind
,
5252 .legacy_cftypes
= mem_cgroup_files
,
5256 #ifdef CONFIG_MEMCG_SWAP
5257 static int __init
enable_swap_account(char *s
)
5259 if (!strcmp(s
, "1"))
5260 really_do_swap_account
= 1;
5261 else if (!strcmp(s
, "0"))
5262 really_do_swap_account
= 0;
5265 __setup("swapaccount=", enable_swap_account
);
5267 static void __init
memsw_file_init(void)
5269 WARN_ON(cgroup_add_legacy_cftypes(&memory_cgrp_subsys
,
5270 memsw_cgroup_files
));
5273 static void __init
enable_swap_cgroup(void)
5275 if (!mem_cgroup_disabled() && really_do_swap_account
) {
5276 do_swap_account
= 1;
5282 static void __init
enable_swap_cgroup(void)
5287 #ifdef CONFIG_MEMCG_SWAP
5289 * mem_cgroup_swapout - transfer a memsw charge to swap
5290 * @page: page whose memsw charge to transfer
5291 * @entry: swap entry to move the charge to
5293 * Transfer the memsw charge of @page to @entry.
5295 void mem_cgroup_swapout(struct page
*page
, swp_entry_t entry
)
5297 struct mem_cgroup
*memcg
;
5298 unsigned short oldid
;
5300 VM_BUG_ON_PAGE(PageLRU(page
), page
);
5301 VM_BUG_ON_PAGE(page_count(page
), page
);
5303 if (!do_swap_account
)
5306 memcg
= page
->mem_cgroup
;
5308 /* Readahead page, never charged */
5312 oldid
= swap_cgroup_record(entry
, mem_cgroup_id(memcg
));
5313 VM_BUG_ON_PAGE(oldid
, page
);
5314 mem_cgroup_swap_statistics(memcg
, true);
5316 page
->mem_cgroup
= NULL
;
5318 if (!mem_cgroup_is_root(memcg
))
5319 page_counter_uncharge(&memcg
->memory
, 1);
5321 /* XXX: caller holds IRQ-safe mapping->tree_lock */
5322 VM_BUG_ON(!irqs_disabled());
5324 mem_cgroup_charge_statistics(memcg
, page
, -1);
5325 memcg_check_events(memcg
, page
);
5329 * mem_cgroup_uncharge_swap - uncharge a swap entry
5330 * @entry: swap entry to uncharge
5332 * Drop the memsw charge associated with @entry.
5334 void mem_cgroup_uncharge_swap(swp_entry_t entry
)
5336 struct mem_cgroup
*memcg
;
5339 if (!do_swap_account
)
5342 id
= swap_cgroup_record(entry
, 0);
5344 memcg
= mem_cgroup_lookup(id
);
5346 if (!mem_cgroup_is_root(memcg
))
5347 page_counter_uncharge(&memcg
->memsw
, 1);
5348 mem_cgroup_swap_statistics(memcg
, false);
5349 css_put(&memcg
->css
);
5356 * mem_cgroup_try_charge - try charging a page
5357 * @page: page to charge
5358 * @mm: mm context of the victim
5359 * @gfp_mask: reclaim mode
5360 * @memcgp: charged memcg return
5362 * Try to charge @page to the memcg that @mm belongs to, reclaiming
5363 * pages according to @gfp_mask if necessary.
5365 * Returns 0 on success, with *@memcgp pointing to the charged memcg.
5366 * Otherwise, an error code is returned.
5368 * After page->mapping has been set up, the caller must finalize the
5369 * charge with mem_cgroup_commit_charge(). Or abort the transaction
5370 * with mem_cgroup_cancel_charge() in case page instantiation fails.
5372 int mem_cgroup_try_charge(struct page
*page
, struct mm_struct
*mm
,
5373 gfp_t gfp_mask
, struct mem_cgroup
**memcgp
)
5375 struct mem_cgroup
*memcg
= NULL
;
5376 unsigned int nr_pages
= 1;
5379 if (mem_cgroup_disabled())
5382 if (PageSwapCache(page
)) {
5384 * Every swap fault against a single page tries to charge the
5385 * page, bail as early as possible. shmem_unuse() encounters
5386 * already charged pages, too. The USED bit is protected by
5387 * the page lock, which serializes swap cache removal, which
5388 * in turn serializes uncharging.
5390 if (page
->mem_cgroup
)
5394 if (PageTransHuge(page
)) {
5395 nr_pages
<<= compound_order(page
);
5396 VM_BUG_ON_PAGE(!PageTransHuge(page
), page
);
5399 if (do_swap_account
&& PageSwapCache(page
))
5400 memcg
= try_get_mem_cgroup_from_page(page
);
5402 memcg
= get_mem_cgroup_from_mm(mm
);
5404 ret
= try_charge(memcg
, gfp_mask
, nr_pages
);
5406 css_put(&memcg
->css
);
5408 if (ret
== -EINTR
) {
5409 memcg
= root_mem_cgroup
;
5418 * mem_cgroup_commit_charge - commit a page charge
5419 * @page: page to charge
5420 * @memcg: memcg to charge the page to
5421 * @lrucare: page might be on LRU already
5423 * Finalize a charge transaction started by mem_cgroup_try_charge(),
5424 * after page->mapping has been set up. This must happen atomically
5425 * as part of the page instantiation, i.e. under the page table lock
5426 * for anonymous pages, under the page lock for page and swap cache.
5428 * In addition, the page must not be on the LRU during the commit, to
5429 * prevent racing with task migration. If it might be, use @lrucare.
5431 * Use mem_cgroup_cancel_charge() to cancel the transaction instead.
5433 void mem_cgroup_commit_charge(struct page
*page
, struct mem_cgroup
*memcg
,
5436 unsigned int nr_pages
= 1;
5438 VM_BUG_ON_PAGE(!page
->mapping
, page
);
5439 VM_BUG_ON_PAGE(PageLRU(page
) && !lrucare
, page
);
5441 if (mem_cgroup_disabled())
5444 * Swap faults will attempt to charge the same page multiple
5445 * times. But reuse_swap_page() might have removed the page
5446 * from swapcache already, so we can't check PageSwapCache().
5451 commit_charge(page
, memcg
, lrucare
);
5453 if (PageTransHuge(page
)) {
5454 nr_pages
<<= compound_order(page
);
5455 VM_BUG_ON_PAGE(!PageTransHuge(page
), page
);
5458 local_irq_disable();
5459 mem_cgroup_charge_statistics(memcg
, page
, nr_pages
);
5460 memcg_check_events(memcg
, page
);
5463 if (do_swap_account
&& PageSwapCache(page
)) {
5464 swp_entry_t entry
= { .val
= page_private(page
) };
5466 * The swap entry might not get freed for a long time,
5467 * let's not wait for it. The page already received a
5468 * memory+swap charge, drop the swap entry duplicate.
5470 mem_cgroup_uncharge_swap(entry
);
5475 * mem_cgroup_cancel_charge - cancel a page charge
5476 * @page: page to charge
5477 * @memcg: memcg to charge the page to
5479 * Cancel a charge transaction started by mem_cgroup_try_charge().
5481 void mem_cgroup_cancel_charge(struct page
*page
, struct mem_cgroup
*memcg
)
5483 unsigned int nr_pages
= 1;
5485 if (mem_cgroup_disabled())
5488 * Swap faults will attempt to charge the same page multiple
5489 * times. But reuse_swap_page() might have removed the page
5490 * from swapcache already, so we can't check PageSwapCache().
5495 if (PageTransHuge(page
)) {
5496 nr_pages
<<= compound_order(page
);
5497 VM_BUG_ON_PAGE(!PageTransHuge(page
), page
);
5500 cancel_charge(memcg
, nr_pages
);
5503 static void uncharge_batch(struct mem_cgroup
*memcg
, unsigned long pgpgout
,
5504 unsigned long nr_anon
, unsigned long nr_file
,
5505 unsigned long nr_huge
, struct page
*dummy_page
)
5507 unsigned long nr_pages
= nr_anon
+ nr_file
;
5508 unsigned long flags
;
5510 if (!mem_cgroup_is_root(memcg
)) {
5511 page_counter_uncharge(&memcg
->memory
, nr_pages
);
5512 if (do_swap_account
)
5513 page_counter_uncharge(&memcg
->memsw
, nr_pages
);
5514 memcg_oom_recover(memcg
);
5517 local_irq_save(flags
);
5518 __this_cpu_sub(memcg
->stat
->count
[MEM_CGROUP_STAT_RSS
], nr_anon
);
5519 __this_cpu_sub(memcg
->stat
->count
[MEM_CGROUP_STAT_CACHE
], nr_file
);
5520 __this_cpu_sub(memcg
->stat
->count
[MEM_CGROUP_STAT_RSS_HUGE
], nr_huge
);
5521 __this_cpu_add(memcg
->stat
->events
[MEM_CGROUP_EVENTS_PGPGOUT
], pgpgout
);
5522 __this_cpu_add(memcg
->stat
->nr_page_events
, nr_pages
);
5523 memcg_check_events(memcg
, dummy_page
);
5524 local_irq_restore(flags
);
5526 if (!mem_cgroup_is_root(memcg
))
5527 css_put_many(&memcg
->css
, nr_pages
);
5530 static void uncharge_list(struct list_head
*page_list
)
5532 struct mem_cgroup
*memcg
= NULL
;
5533 unsigned long nr_anon
= 0;
5534 unsigned long nr_file
= 0;
5535 unsigned long nr_huge
= 0;
5536 unsigned long pgpgout
= 0;
5537 struct list_head
*next
;
5540 next
= page_list
->next
;
5542 unsigned int nr_pages
= 1;
5544 page
= list_entry(next
, struct page
, lru
);
5545 next
= page
->lru
.next
;
5547 VM_BUG_ON_PAGE(PageLRU(page
), page
);
5548 VM_BUG_ON_PAGE(page_count(page
), page
);
5550 if (!page
->mem_cgroup
)
5554 * Nobody should be changing or seriously looking at
5555 * page->mem_cgroup at this point, we have fully
5556 * exclusive access to the page.
5559 if (memcg
!= page
->mem_cgroup
) {
5561 uncharge_batch(memcg
, pgpgout
, nr_anon
, nr_file
,
5563 pgpgout
= nr_anon
= nr_file
= nr_huge
= 0;
5565 memcg
= page
->mem_cgroup
;
5568 if (PageTransHuge(page
)) {
5569 nr_pages
<<= compound_order(page
);
5570 VM_BUG_ON_PAGE(!PageTransHuge(page
), page
);
5571 nr_huge
+= nr_pages
;
5575 nr_anon
+= nr_pages
;
5577 nr_file
+= nr_pages
;
5579 page
->mem_cgroup
= NULL
;
5582 } while (next
!= page_list
);
5585 uncharge_batch(memcg
, pgpgout
, nr_anon
, nr_file
,
5590 * mem_cgroup_uncharge - uncharge a page
5591 * @page: page to uncharge
5593 * Uncharge a page previously charged with mem_cgroup_try_charge() and
5594 * mem_cgroup_commit_charge().
5596 void mem_cgroup_uncharge(struct page
*page
)
5598 if (mem_cgroup_disabled())
5601 /* Don't touch page->lru of any random page, pre-check: */
5602 if (!page
->mem_cgroup
)
5605 INIT_LIST_HEAD(&page
->lru
);
5606 uncharge_list(&page
->lru
);
5610 * mem_cgroup_uncharge_list - uncharge a list of page
5611 * @page_list: list of pages to uncharge
5613 * Uncharge a list of pages previously charged with
5614 * mem_cgroup_try_charge() and mem_cgroup_commit_charge().
5616 void mem_cgroup_uncharge_list(struct list_head
*page_list
)
5618 if (mem_cgroup_disabled())
5621 if (!list_empty(page_list
))
5622 uncharge_list(page_list
);
5626 * mem_cgroup_migrate - migrate a charge to another page
5627 * @oldpage: currently charged page
5628 * @newpage: page to transfer the charge to
5629 * @lrucare: either or both pages might be on the LRU already
5631 * Migrate the charge from @oldpage to @newpage.
5633 * Both pages must be locked, @newpage->mapping must be set up.
5635 void mem_cgroup_migrate(struct page
*oldpage
, struct page
*newpage
,
5638 struct mem_cgroup
*memcg
;
5641 VM_BUG_ON_PAGE(!PageLocked(oldpage
), oldpage
);
5642 VM_BUG_ON_PAGE(!PageLocked(newpage
), newpage
);
5643 VM_BUG_ON_PAGE(!lrucare
&& PageLRU(oldpage
), oldpage
);
5644 VM_BUG_ON_PAGE(!lrucare
&& PageLRU(newpage
), newpage
);
5645 VM_BUG_ON_PAGE(PageAnon(oldpage
) != PageAnon(newpage
), newpage
);
5646 VM_BUG_ON_PAGE(PageTransHuge(oldpage
) != PageTransHuge(newpage
),
5649 if (mem_cgroup_disabled())
5652 /* Page cache replacement: new page already charged? */
5653 if (newpage
->mem_cgroup
)
5657 * Swapcache readahead pages can get migrated before being
5658 * charged, and migration from compaction can happen to an
5659 * uncharged page when the PFN walker finds a page that
5660 * reclaim just put back on the LRU but has not released yet.
5662 memcg
= oldpage
->mem_cgroup
;
5667 lock_page_lru(oldpage
, &isolated
);
5669 oldpage
->mem_cgroup
= NULL
;
5672 unlock_page_lru(oldpage
, isolated
);
5674 commit_charge(newpage
, memcg
, lrucare
);
5678 * subsys_initcall() for memory controller.
5680 * Some parts like hotcpu_notifier() have to be initialized from this context
5681 * because of lock dependencies (cgroup_lock -> cpu hotplug) but basically
5682 * everything that doesn't depend on a specific mem_cgroup structure should
5683 * be initialized from here.
5685 static int __init
mem_cgroup_init(void)
5687 hotcpu_notifier(memcg_cpu_hotplug_callback
, 0);
5688 enable_swap_cgroup();
5689 mem_cgroup_soft_limit_tree_init();
5693 subsys_initcall(mem_cgroup_init
);