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
18 * Charge lifetime sanitation
19 * Lockless page tracking & accounting
20 * Unified hierarchy configuration model
21 * Copyright (C) 2015 Red Hat, Inc., Johannes Weiner
23 * This program is free software; you can redistribute it and/or modify
24 * it under the terms of the GNU General Public License as published by
25 * the Free Software Foundation; either version 2 of the License, or
26 * (at your option) any later version.
28 * This program is distributed in the hope that it will be useful,
29 * but WITHOUT ANY WARRANTY; without even the implied warranty of
30 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
31 * GNU General Public License for more details.
34 #include <linux/page_counter.h>
35 #include <linux/memcontrol.h>
36 #include <linux/cgroup.h>
38 #include <linux/hugetlb.h>
39 #include <linux/pagemap.h>
40 #include <linux/smp.h>
41 #include <linux/page-flags.h>
42 #include <linux/backing-dev.h>
43 #include <linux/bit_spinlock.h>
44 #include <linux/rcupdate.h>
45 #include <linux/limits.h>
46 #include <linux/export.h>
47 #include <linux/mutex.h>
48 #include <linux/rbtree.h>
49 #include <linux/slab.h>
50 #include <linux/swap.h>
51 #include <linux/swapops.h>
52 #include <linux/spinlock.h>
53 #include <linux/eventfd.h>
54 #include <linux/poll.h>
55 #include <linux/sort.h>
57 #include <linux/seq_file.h>
58 #include <linux/vmpressure.h>
59 #include <linux/mm_inline.h>
60 #include <linux/swap_cgroup.h>
61 #include <linux/cpu.h>
62 #include <linux/oom.h>
63 #include <linux/lockdep.h>
64 #include <linux/file.h>
68 #include <net/tcp_memcontrol.h>
71 #include <asm/uaccess.h>
73 #include <trace/events/vmscan.h>
75 struct cgroup_subsys memory_cgrp_subsys __read_mostly
;
76 EXPORT_SYMBOL(memory_cgrp_subsys
);
78 #define MEM_CGROUP_RECLAIM_RETRIES 5
79 static struct mem_cgroup
*root_mem_cgroup __read_mostly
;
81 /* Whether the swap controller is active */
82 #ifdef CONFIG_MEMCG_SWAP
83 int do_swap_account __read_mostly
;
85 #define do_swap_account 0
88 static const char * const mem_cgroup_stat_names
[] = {
97 static const char * const mem_cgroup_events_names
[] = {
104 static const char * const mem_cgroup_lru_names
[] = {
113 * Per memcg event counter is incremented at every pagein/pageout. With THP,
114 * it will be incremated by the number of pages. This counter is used for
115 * for trigger some periodic events. This is straightforward and better
116 * than using jiffies etc. to handle periodic memcg event.
118 enum mem_cgroup_events_target
{
119 MEM_CGROUP_TARGET_THRESH
,
120 MEM_CGROUP_TARGET_SOFTLIMIT
,
121 MEM_CGROUP_TARGET_NUMAINFO
,
124 #define THRESHOLDS_EVENTS_TARGET 128
125 #define SOFTLIMIT_EVENTS_TARGET 1024
126 #define NUMAINFO_EVENTS_TARGET 1024
128 struct mem_cgroup_stat_cpu
{
129 long count
[MEM_CGROUP_STAT_NSTATS
];
130 unsigned long events
[MEMCG_NR_EVENTS
];
131 unsigned long nr_page_events
;
132 unsigned long targets
[MEM_CGROUP_NTARGETS
];
135 struct reclaim_iter
{
136 struct mem_cgroup
*position
;
137 /* scan generation, increased every round-trip */
138 unsigned int generation
;
142 * per-zone information in memory controller.
144 struct mem_cgroup_per_zone
{
145 struct lruvec lruvec
;
146 unsigned long lru_size
[NR_LRU_LISTS
];
148 struct reclaim_iter iter
[DEF_PRIORITY
+ 1];
150 struct rb_node tree_node
; /* RB tree node */
151 unsigned long usage_in_excess
;/* Set to the value by which */
152 /* the soft limit is exceeded*/
154 struct mem_cgroup
*memcg
; /* Back pointer, we cannot */
155 /* use container_of */
158 struct mem_cgroup_per_node
{
159 struct mem_cgroup_per_zone zoneinfo
[MAX_NR_ZONES
];
163 * Cgroups above their limits are maintained in a RB-Tree, independent of
164 * their hierarchy representation
167 struct mem_cgroup_tree_per_zone
{
168 struct rb_root rb_root
;
172 struct mem_cgroup_tree_per_node
{
173 struct mem_cgroup_tree_per_zone rb_tree_per_zone
[MAX_NR_ZONES
];
176 struct mem_cgroup_tree
{
177 struct mem_cgroup_tree_per_node
*rb_tree_per_node
[MAX_NUMNODES
];
180 static struct mem_cgroup_tree soft_limit_tree __read_mostly
;
182 struct mem_cgroup_threshold
{
183 struct eventfd_ctx
*eventfd
;
184 unsigned long threshold
;
188 struct mem_cgroup_threshold_ary
{
189 /* An array index points to threshold just below or equal to usage. */
190 int current_threshold
;
191 /* Size of entries[] */
193 /* Array of thresholds */
194 struct mem_cgroup_threshold entries
[0];
197 struct mem_cgroup_thresholds
{
198 /* Primary thresholds array */
199 struct mem_cgroup_threshold_ary
*primary
;
201 * Spare threshold array.
202 * This is needed to make mem_cgroup_unregister_event() "never fail".
203 * It must be able to store at least primary->size - 1 entries.
205 struct mem_cgroup_threshold_ary
*spare
;
209 struct mem_cgroup_eventfd_list
{
210 struct list_head list
;
211 struct eventfd_ctx
*eventfd
;
215 * cgroup_event represents events which userspace want to receive.
217 struct mem_cgroup_event
{
219 * memcg which the event belongs to.
221 struct mem_cgroup
*memcg
;
223 * eventfd to signal userspace about the event.
225 struct eventfd_ctx
*eventfd
;
227 * Each of these stored in a list by the cgroup.
229 struct list_head list
;
231 * register_event() callback will be used to add new userspace
232 * waiter for changes related to this event. Use eventfd_signal()
233 * on eventfd to send notification to userspace.
235 int (*register_event
)(struct mem_cgroup
*memcg
,
236 struct eventfd_ctx
*eventfd
, const char *args
);
238 * unregister_event() callback will be called when userspace closes
239 * the eventfd or on cgroup removing. This callback must be set,
240 * if you want provide notification functionality.
242 void (*unregister_event
)(struct mem_cgroup
*memcg
,
243 struct eventfd_ctx
*eventfd
);
245 * All fields below needed to unregister event when
246 * userspace closes eventfd.
249 wait_queue_head_t
*wqh
;
251 struct work_struct remove
;
254 static void mem_cgroup_threshold(struct mem_cgroup
*memcg
);
255 static void mem_cgroup_oom_notify(struct mem_cgroup
*memcg
);
258 * The memory controller data structure. The memory controller controls both
259 * page cache and RSS per cgroup. We would eventually like to provide
260 * statistics based on the statistics developed by Rik Van Riel for clock-pro,
261 * to help the administrator determine what knobs to tune.
264 struct cgroup_subsys_state css
;
266 /* Accounted resources */
267 struct page_counter memory
;
268 struct page_counter memsw
;
269 struct page_counter kmem
;
271 /* Normal memory consumption range */
275 unsigned long soft_limit
;
277 /* vmpressure notifications */
278 struct vmpressure vmpressure
;
280 /* css_online() has been completed */
284 * Should the accounting and control be hierarchical, per subtree?
290 atomic_t oom_wakeups
;
293 /* OOM-Killer disable */
294 int oom_kill_disable
;
296 /* protect arrays of thresholds */
297 struct mutex thresholds_lock
;
299 /* thresholds for memory usage. RCU-protected */
300 struct mem_cgroup_thresholds thresholds
;
302 /* thresholds for mem+swap usage. RCU-protected */
303 struct mem_cgroup_thresholds memsw_thresholds
;
305 /* For oom notifier event fd */
306 struct list_head oom_notify
;
309 * Should we move charges of a task when a task is moved into this
310 * mem_cgroup ? And what type of charges should we move ?
312 unsigned long move_charge_at_immigrate
;
314 * set > 0 if pages under this cgroup are moving to other cgroup.
316 atomic_t moving_account
;
317 /* taken only while moving_account > 0 */
318 spinlock_t move_lock
;
319 struct task_struct
*move_lock_task
;
320 unsigned long move_lock_flags
;
324 struct mem_cgroup_stat_cpu __percpu
*stat
;
326 * used when a cpu is offlined or other synchronizations
327 * See mem_cgroup_read_stat().
329 struct mem_cgroup_stat_cpu nocpu_base
;
330 spinlock_t pcp_counter_lock
;
332 #if defined(CONFIG_MEMCG_KMEM) && defined(CONFIG_INET)
333 struct cg_proto tcp_mem
;
335 #if defined(CONFIG_MEMCG_KMEM)
336 /* Index in the kmem_cache->memcg_params.memcg_caches array */
338 bool kmem_acct_activated
;
339 bool kmem_acct_active
;
342 int last_scanned_node
;
344 nodemask_t scan_nodes
;
345 atomic_t numainfo_events
;
346 atomic_t numainfo_updating
;
349 /* List of events which userspace want to receive */
350 struct list_head event_list
;
351 spinlock_t event_list_lock
;
353 struct mem_cgroup_per_node
*nodeinfo
[0];
354 /* WARNING: nodeinfo must be the last member here */
357 #ifdef CONFIG_MEMCG_KMEM
358 bool memcg_kmem_is_active(struct mem_cgroup
*memcg
)
360 return memcg
->kmem_acct_active
;
364 /* Stuffs for move charges at task migration. */
366 * Types of charges to be moved.
368 #define MOVE_ANON 0x1U
369 #define MOVE_FILE 0x2U
370 #define MOVE_MASK (MOVE_ANON | MOVE_FILE)
372 /* "mc" and its members are protected by cgroup_mutex */
373 static struct move_charge_struct
{
374 spinlock_t lock
; /* for from, to */
375 struct mem_cgroup
*from
;
376 struct mem_cgroup
*to
;
378 unsigned long precharge
;
379 unsigned long moved_charge
;
380 unsigned long moved_swap
;
381 struct task_struct
*moving_task
; /* a task moving charges */
382 wait_queue_head_t waitq
; /* a waitq for other context */
384 .lock
= __SPIN_LOCK_UNLOCKED(mc
.lock
),
385 .waitq
= __WAIT_QUEUE_HEAD_INITIALIZER(mc
.waitq
),
389 * Maximum loops in mem_cgroup_hierarchical_reclaim(), used for soft
390 * limit reclaim to prevent infinite loops, if they ever occur.
392 #define MEM_CGROUP_MAX_RECLAIM_LOOPS 100
393 #define MEM_CGROUP_MAX_SOFT_LIMIT_RECLAIM_LOOPS 2
396 MEM_CGROUP_CHARGE_TYPE_CACHE
= 0,
397 MEM_CGROUP_CHARGE_TYPE_ANON
,
398 MEM_CGROUP_CHARGE_TYPE_SWAPOUT
, /* for accounting swapcache */
399 MEM_CGROUP_CHARGE_TYPE_DROP
, /* a page was unused swap cache */
403 /* for encoding cft->private value on file */
411 #define MEMFILE_PRIVATE(x, val) ((x) << 16 | (val))
412 #define MEMFILE_TYPE(val) ((val) >> 16 & 0xffff)
413 #define MEMFILE_ATTR(val) ((val) & 0xffff)
414 /* Used for OOM nofiier */
415 #define OOM_CONTROL (0)
418 * The memcg_create_mutex will be held whenever a new cgroup is created.
419 * As a consequence, any change that needs to protect against new child cgroups
420 * appearing has to hold it as well.
422 static DEFINE_MUTEX(memcg_create_mutex
);
424 struct mem_cgroup
*mem_cgroup_from_css(struct cgroup_subsys_state
*s
)
426 return s
? container_of(s
, struct mem_cgroup
, css
) : NULL
;
429 /* Some nice accessors for the vmpressure. */
430 struct vmpressure
*memcg_to_vmpressure(struct mem_cgroup
*memcg
)
433 memcg
= root_mem_cgroup
;
434 return &memcg
->vmpressure
;
437 struct cgroup_subsys_state
*vmpressure_to_css(struct vmpressure
*vmpr
)
439 return &container_of(vmpr
, struct mem_cgroup
, vmpressure
)->css
;
442 static inline bool mem_cgroup_is_root(struct mem_cgroup
*memcg
)
444 return (memcg
== root_mem_cgroup
);
448 * We restrict the id in the range of [1, 65535], so it can fit into
451 #define MEM_CGROUP_ID_MAX USHRT_MAX
453 static inline unsigned short mem_cgroup_id(struct mem_cgroup
*memcg
)
455 return memcg
->css
.id
;
459 * A helper function to get mem_cgroup from ID. must be called under
460 * rcu_read_lock(). The caller is responsible for calling
461 * css_tryget_online() if the mem_cgroup is used for charging. (dropping
462 * refcnt from swap can be called against removed memcg.)
464 static inline struct mem_cgroup
*mem_cgroup_from_id(unsigned short id
)
466 struct cgroup_subsys_state
*css
;
468 css
= css_from_id(id
, &memory_cgrp_subsys
);
469 return mem_cgroup_from_css(css
);
472 /* Writing them here to avoid exposing memcg's inner layout */
473 #if defined(CONFIG_INET) && defined(CONFIG_MEMCG_KMEM)
475 void sock_update_memcg(struct sock
*sk
)
477 if (mem_cgroup_sockets_enabled
) {
478 struct mem_cgroup
*memcg
;
479 struct cg_proto
*cg_proto
;
481 BUG_ON(!sk
->sk_prot
->proto_cgroup
);
483 /* Socket cloning can throw us here with sk_cgrp already
484 * filled. It won't however, necessarily happen from
485 * process context. So the test for root memcg given
486 * the current task's memcg won't help us in this case.
488 * Respecting the original socket's memcg is a better
489 * decision in this case.
492 BUG_ON(mem_cgroup_is_root(sk
->sk_cgrp
->memcg
));
493 css_get(&sk
->sk_cgrp
->memcg
->css
);
498 memcg
= mem_cgroup_from_task(current
);
499 cg_proto
= sk
->sk_prot
->proto_cgroup(memcg
);
500 if (!mem_cgroup_is_root(memcg
) &&
501 memcg_proto_active(cg_proto
) &&
502 css_tryget_online(&memcg
->css
)) {
503 sk
->sk_cgrp
= cg_proto
;
508 EXPORT_SYMBOL(sock_update_memcg
);
510 void sock_release_memcg(struct sock
*sk
)
512 if (mem_cgroup_sockets_enabled
&& sk
->sk_cgrp
) {
513 struct mem_cgroup
*memcg
;
514 WARN_ON(!sk
->sk_cgrp
->memcg
);
515 memcg
= sk
->sk_cgrp
->memcg
;
516 css_put(&sk
->sk_cgrp
->memcg
->css
);
520 struct cg_proto
*tcp_proto_cgroup(struct mem_cgroup
*memcg
)
522 if (!memcg
|| mem_cgroup_is_root(memcg
))
525 return &memcg
->tcp_mem
;
527 EXPORT_SYMBOL(tcp_proto_cgroup
);
531 #ifdef CONFIG_MEMCG_KMEM
533 * This will be the memcg's index in each cache's ->memcg_params.memcg_caches.
534 * The main reason for not using cgroup id for this:
535 * this works better in sparse environments, where we have a lot of memcgs,
536 * but only a few kmem-limited. Or also, if we have, for instance, 200
537 * memcgs, and none but the 200th is kmem-limited, we'd have to have a
538 * 200 entry array for that.
540 * The current size of the caches array is stored in memcg_nr_cache_ids. It
541 * will double each time we have to increase it.
543 static DEFINE_IDA(memcg_cache_ida
);
544 int memcg_nr_cache_ids
;
546 /* Protects memcg_nr_cache_ids */
547 static DECLARE_RWSEM(memcg_cache_ids_sem
);
549 void memcg_get_cache_ids(void)
551 down_read(&memcg_cache_ids_sem
);
554 void memcg_put_cache_ids(void)
556 up_read(&memcg_cache_ids_sem
);
560 * MIN_SIZE is different than 1, because we would like to avoid going through
561 * the alloc/free process all the time. In a small machine, 4 kmem-limited
562 * cgroups is a reasonable guess. In the future, it could be a parameter or
563 * tunable, but that is strictly not necessary.
565 * MAX_SIZE should be as large as the number of cgrp_ids. Ideally, we could get
566 * this constant directly from cgroup, but it is understandable that this is
567 * better kept as an internal representation in cgroup.c. In any case, the
568 * cgrp_id space is not getting any smaller, and we don't have to necessarily
569 * increase ours as well if it increases.
571 #define MEMCG_CACHES_MIN_SIZE 4
572 #define MEMCG_CACHES_MAX_SIZE MEM_CGROUP_ID_MAX
575 * A lot of the calls to the cache allocation functions are expected to be
576 * inlined by the compiler. Since the calls to memcg_kmem_get_cache are
577 * conditional to this static branch, we'll have to allow modules that does
578 * kmem_cache_alloc and the such to see this symbol as well
580 struct static_key memcg_kmem_enabled_key
;
581 EXPORT_SYMBOL(memcg_kmem_enabled_key
);
583 #endif /* CONFIG_MEMCG_KMEM */
585 static struct mem_cgroup_per_zone
*
586 mem_cgroup_zone_zoneinfo(struct mem_cgroup
*memcg
, struct zone
*zone
)
588 int nid
= zone_to_nid(zone
);
589 int zid
= zone_idx(zone
);
591 return &memcg
->nodeinfo
[nid
]->zoneinfo
[zid
];
594 struct cgroup_subsys_state
*mem_cgroup_css(struct mem_cgroup
*memcg
)
599 static struct mem_cgroup_per_zone
*
600 mem_cgroup_page_zoneinfo(struct mem_cgroup
*memcg
, struct page
*page
)
602 int nid
= page_to_nid(page
);
603 int zid
= page_zonenum(page
);
605 return &memcg
->nodeinfo
[nid
]->zoneinfo
[zid
];
608 static struct mem_cgroup_tree_per_zone
*
609 soft_limit_tree_node_zone(int nid
, int zid
)
611 return &soft_limit_tree
.rb_tree_per_node
[nid
]->rb_tree_per_zone
[zid
];
614 static struct mem_cgroup_tree_per_zone
*
615 soft_limit_tree_from_page(struct page
*page
)
617 int nid
= page_to_nid(page
);
618 int zid
= page_zonenum(page
);
620 return &soft_limit_tree
.rb_tree_per_node
[nid
]->rb_tree_per_zone
[zid
];
623 static void __mem_cgroup_insert_exceeded(struct mem_cgroup_per_zone
*mz
,
624 struct mem_cgroup_tree_per_zone
*mctz
,
625 unsigned long new_usage_in_excess
)
627 struct rb_node
**p
= &mctz
->rb_root
.rb_node
;
628 struct rb_node
*parent
= NULL
;
629 struct mem_cgroup_per_zone
*mz_node
;
634 mz
->usage_in_excess
= new_usage_in_excess
;
635 if (!mz
->usage_in_excess
)
639 mz_node
= rb_entry(parent
, struct mem_cgroup_per_zone
,
641 if (mz
->usage_in_excess
< mz_node
->usage_in_excess
)
644 * We can't avoid mem cgroups that are over their soft
645 * limit by the same amount
647 else if (mz
->usage_in_excess
>= mz_node
->usage_in_excess
)
650 rb_link_node(&mz
->tree_node
, parent
, p
);
651 rb_insert_color(&mz
->tree_node
, &mctz
->rb_root
);
655 static void __mem_cgroup_remove_exceeded(struct mem_cgroup_per_zone
*mz
,
656 struct mem_cgroup_tree_per_zone
*mctz
)
660 rb_erase(&mz
->tree_node
, &mctz
->rb_root
);
664 static void mem_cgroup_remove_exceeded(struct mem_cgroup_per_zone
*mz
,
665 struct mem_cgroup_tree_per_zone
*mctz
)
669 spin_lock_irqsave(&mctz
->lock
, flags
);
670 __mem_cgroup_remove_exceeded(mz
, mctz
);
671 spin_unlock_irqrestore(&mctz
->lock
, flags
);
674 static unsigned long soft_limit_excess(struct mem_cgroup
*memcg
)
676 unsigned long nr_pages
= page_counter_read(&memcg
->memory
);
677 unsigned long soft_limit
= READ_ONCE(memcg
->soft_limit
);
678 unsigned long excess
= 0;
680 if (nr_pages
> soft_limit
)
681 excess
= nr_pages
- soft_limit
;
686 static void mem_cgroup_update_tree(struct mem_cgroup
*memcg
, struct page
*page
)
688 unsigned long excess
;
689 struct mem_cgroup_per_zone
*mz
;
690 struct mem_cgroup_tree_per_zone
*mctz
;
692 mctz
= soft_limit_tree_from_page(page
);
694 * Necessary to update all ancestors when hierarchy is used.
695 * because their event counter is not touched.
697 for (; memcg
; memcg
= parent_mem_cgroup(memcg
)) {
698 mz
= mem_cgroup_page_zoneinfo(memcg
, page
);
699 excess
= soft_limit_excess(memcg
);
701 * We have to update the tree if mz is on RB-tree or
702 * mem is over its softlimit.
704 if (excess
|| mz
->on_tree
) {
707 spin_lock_irqsave(&mctz
->lock
, flags
);
708 /* if on-tree, remove it */
710 __mem_cgroup_remove_exceeded(mz
, mctz
);
712 * Insert again. mz->usage_in_excess will be updated.
713 * If excess is 0, no tree ops.
715 __mem_cgroup_insert_exceeded(mz
, mctz
, excess
);
716 spin_unlock_irqrestore(&mctz
->lock
, flags
);
721 static void mem_cgroup_remove_from_trees(struct mem_cgroup
*memcg
)
723 struct mem_cgroup_tree_per_zone
*mctz
;
724 struct mem_cgroup_per_zone
*mz
;
728 for (zid
= 0; zid
< MAX_NR_ZONES
; zid
++) {
729 mz
= &memcg
->nodeinfo
[nid
]->zoneinfo
[zid
];
730 mctz
= soft_limit_tree_node_zone(nid
, zid
);
731 mem_cgroup_remove_exceeded(mz
, mctz
);
736 static struct mem_cgroup_per_zone
*
737 __mem_cgroup_largest_soft_limit_node(struct mem_cgroup_tree_per_zone
*mctz
)
739 struct rb_node
*rightmost
= NULL
;
740 struct mem_cgroup_per_zone
*mz
;
744 rightmost
= rb_last(&mctz
->rb_root
);
746 goto done
; /* Nothing to reclaim from */
748 mz
= rb_entry(rightmost
, struct mem_cgroup_per_zone
, tree_node
);
750 * Remove the node now but someone else can add it back,
751 * we will to add it back at the end of reclaim to its correct
752 * position in the tree.
754 __mem_cgroup_remove_exceeded(mz
, mctz
);
755 if (!soft_limit_excess(mz
->memcg
) ||
756 !css_tryget_online(&mz
->memcg
->css
))
762 static struct mem_cgroup_per_zone
*
763 mem_cgroup_largest_soft_limit_node(struct mem_cgroup_tree_per_zone
*mctz
)
765 struct mem_cgroup_per_zone
*mz
;
767 spin_lock_irq(&mctz
->lock
);
768 mz
= __mem_cgroup_largest_soft_limit_node(mctz
);
769 spin_unlock_irq(&mctz
->lock
);
774 * Implementation Note: reading percpu statistics for memcg.
776 * Both of vmstat[] and percpu_counter has threshold and do periodic
777 * synchronization to implement "quick" read. There are trade-off between
778 * reading cost and precision of value. Then, we may have a chance to implement
779 * a periodic synchronizion of counter in memcg's counter.
781 * But this _read() function is used for user interface now. The user accounts
782 * memory usage by memory cgroup and he _always_ requires exact value because
783 * he accounts memory. Even if we provide quick-and-fuzzy read, we always
784 * have to visit all online cpus and make sum. So, for now, unnecessary
785 * synchronization is not implemented. (just implemented for cpu hotplug)
787 * If there are kernel internal actions which can make use of some not-exact
788 * value, and reading all cpu value can be performance bottleneck in some
789 * common workload, threashold and synchonization as vmstat[] should be
792 static long mem_cgroup_read_stat(struct mem_cgroup
*memcg
,
793 enum mem_cgroup_stat_index idx
)
799 for_each_online_cpu(cpu
)
800 val
+= per_cpu(memcg
->stat
->count
[idx
], cpu
);
801 #ifdef CONFIG_HOTPLUG_CPU
802 spin_lock(&memcg
->pcp_counter_lock
);
803 val
+= memcg
->nocpu_base
.count
[idx
];
804 spin_unlock(&memcg
->pcp_counter_lock
);
810 static unsigned long mem_cgroup_read_events(struct mem_cgroup
*memcg
,
811 enum mem_cgroup_events_index idx
)
813 unsigned long val
= 0;
817 for_each_online_cpu(cpu
)
818 val
+= per_cpu(memcg
->stat
->events
[idx
], cpu
);
819 #ifdef CONFIG_HOTPLUG_CPU
820 spin_lock(&memcg
->pcp_counter_lock
);
821 val
+= memcg
->nocpu_base
.events
[idx
];
822 spin_unlock(&memcg
->pcp_counter_lock
);
828 static void mem_cgroup_charge_statistics(struct mem_cgroup
*memcg
,
833 * Here, RSS means 'mapped anon' and anon's SwapCache. Shmem/tmpfs is
834 * counted as CACHE even if it's on ANON LRU.
837 __this_cpu_add(memcg
->stat
->count
[MEM_CGROUP_STAT_RSS
],
840 __this_cpu_add(memcg
->stat
->count
[MEM_CGROUP_STAT_CACHE
],
843 if (PageTransHuge(page
))
844 __this_cpu_add(memcg
->stat
->count
[MEM_CGROUP_STAT_RSS_HUGE
],
847 /* pagein of a big page is an event. So, ignore page size */
849 __this_cpu_inc(memcg
->stat
->events
[MEM_CGROUP_EVENTS_PGPGIN
]);
851 __this_cpu_inc(memcg
->stat
->events
[MEM_CGROUP_EVENTS_PGPGOUT
]);
852 nr_pages
= -nr_pages
; /* for event */
855 __this_cpu_add(memcg
->stat
->nr_page_events
, nr_pages
);
858 unsigned long mem_cgroup_get_lru_size(struct lruvec
*lruvec
, enum lru_list lru
)
860 struct mem_cgroup_per_zone
*mz
;
862 mz
= container_of(lruvec
, struct mem_cgroup_per_zone
, lruvec
);
863 return mz
->lru_size
[lru
];
866 static unsigned long mem_cgroup_node_nr_lru_pages(struct mem_cgroup
*memcg
,
868 unsigned int lru_mask
)
870 unsigned long nr
= 0;
873 VM_BUG_ON((unsigned)nid
>= nr_node_ids
);
875 for (zid
= 0; zid
< MAX_NR_ZONES
; zid
++) {
876 struct mem_cgroup_per_zone
*mz
;
880 if (!(BIT(lru
) & lru_mask
))
882 mz
= &memcg
->nodeinfo
[nid
]->zoneinfo
[zid
];
883 nr
+= mz
->lru_size
[lru
];
889 static unsigned long mem_cgroup_nr_lru_pages(struct mem_cgroup
*memcg
,
890 unsigned int lru_mask
)
892 unsigned long nr
= 0;
895 for_each_node_state(nid
, N_MEMORY
)
896 nr
+= mem_cgroup_node_nr_lru_pages(memcg
, nid
, lru_mask
);
900 static bool mem_cgroup_event_ratelimit(struct mem_cgroup
*memcg
,
901 enum mem_cgroup_events_target target
)
903 unsigned long val
, next
;
905 val
= __this_cpu_read(memcg
->stat
->nr_page_events
);
906 next
= __this_cpu_read(memcg
->stat
->targets
[target
]);
907 /* from time_after() in jiffies.h */
908 if ((long)next
- (long)val
< 0) {
910 case MEM_CGROUP_TARGET_THRESH
:
911 next
= val
+ THRESHOLDS_EVENTS_TARGET
;
913 case MEM_CGROUP_TARGET_SOFTLIMIT
:
914 next
= val
+ SOFTLIMIT_EVENTS_TARGET
;
916 case MEM_CGROUP_TARGET_NUMAINFO
:
917 next
= val
+ NUMAINFO_EVENTS_TARGET
;
922 __this_cpu_write(memcg
->stat
->targets
[target
], next
);
929 * Check events in order.
932 static void memcg_check_events(struct mem_cgroup
*memcg
, struct page
*page
)
934 /* threshold event is triggered in finer grain than soft limit */
935 if (unlikely(mem_cgroup_event_ratelimit(memcg
,
936 MEM_CGROUP_TARGET_THRESH
))) {
938 bool do_numainfo __maybe_unused
;
940 do_softlimit
= mem_cgroup_event_ratelimit(memcg
,
941 MEM_CGROUP_TARGET_SOFTLIMIT
);
943 do_numainfo
= mem_cgroup_event_ratelimit(memcg
,
944 MEM_CGROUP_TARGET_NUMAINFO
);
946 mem_cgroup_threshold(memcg
);
947 if (unlikely(do_softlimit
))
948 mem_cgroup_update_tree(memcg
, page
);
950 if (unlikely(do_numainfo
))
951 atomic_inc(&memcg
->numainfo_events
);
956 struct mem_cgroup
*mem_cgroup_from_task(struct task_struct
*p
)
959 * mm_update_next_owner() may clear mm->owner to NULL
960 * if it races with swapoff, page migration, etc.
961 * So this can be called with p == NULL.
966 return mem_cgroup_from_css(task_css(p
, memory_cgrp_id
));
969 static struct mem_cgroup
*get_mem_cgroup_from_mm(struct mm_struct
*mm
)
971 struct mem_cgroup
*memcg
= NULL
;
976 * Page cache insertions can happen withou an
977 * actual mm context, e.g. during disk probing
978 * on boot, loopback IO, acct() writes etc.
981 memcg
= root_mem_cgroup
;
983 memcg
= mem_cgroup_from_task(rcu_dereference(mm
->owner
));
984 if (unlikely(!memcg
))
985 memcg
= root_mem_cgroup
;
987 } while (!css_tryget_online(&memcg
->css
));
993 * mem_cgroup_iter - iterate over memory cgroup hierarchy
994 * @root: hierarchy root
995 * @prev: previously returned memcg, NULL on first invocation
996 * @reclaim: cookie for shared reclaim walks, NULL for full walks
998 * Returns references to children of the hierarchy below @root, or
999 * @root itself, or %NULL after a full round-trip.
1001 * Caller must pass the return value in @prev on subsequent
1002 * invocations for reference counting, or use mem_cgroup_iter_break()
1003 * to cancel a hierarchy walk before the round-trip is complete.
1005 * Reclaimers can specify a zone and a priority level in @reclaim to
1006 * divide up the memcgs in the hierarchy among all concurrent
1007 * reclaimers operating on the same zone and priority.
1009 struct mem_cgroup
*mem_cgroup_iter(struct mem_cgroup
*root
,
1010 struct mem_cgroup
*prev
,
1011 struct mem_cgroup_reclaim_cookie
*reclaim
)
1013 struct reclaim_iter
*uninitialized_var(iter
);
1014 struct cgroup_subsys_state
*css
= NULL
;
1015 struct mem_cgroup
*memcg
= NULL
;
1016 struct mem_cgroup
*pos
= NULL
;
1018 if (mem_cgroup_disabled())
1022 root
= root_mem_cgroup
;
1024 if (prev
&& !reclaim
)
1027 if (!root
->use_hierarchy
&& root
!= root_mem_cgroup
) {
1036 struct mem_cgroup_per_zone
*mz
;
1038 mz
= mem_cgroup_zone_zoneinfo(root
, reclaim
->zone
);
1039 iter
= &mz
->iter
[reclaim
->priority
];
1041 if (prev
&& reclaim
->generation
!= iter
->generation
)
1045 pos
= READ_ONCE(iter
->position
);
1047 * A racing update may change the position and
1048 * put the last reference, hence css_tryget(),
1049 * or retry to see the updated position.
1051 } while (pos
&& !css_tryget(&pos
->css
));
1058 css
= css_next_descendant_pre(css
, &root
->css
);
1061 * Reclaimers share the hierarchy walk, and a
1062 * new one might jump in right at the end of
1063 * the hierarchy - make sure they see at least
1064 * one group and restart from the beginning.
1072 * Verify the css and acquire a reference. The root
1073 * is provided by the caller, so we know it's alive
1074 * and kicking, and don't take an extra reference.
1076 memcg
= mem_cgroup_from_css(css
);
1078 if (css
== &root
->css
)
1081 if (css_tryget(css
)) {
1083 * Make sure the memcg is initialized:
1084 * mem_cgroup_css_online() orders the the
1085 * initialization against setting the flag.
1087 if (smp_load_acquire(&memcg
->initialized
))
1097 if (cmpxchg(&iter
->position
, pos
, memcg
) == pos
) {
1099 css_get(&memcg
->css
);
1105 * pairs with css_tryget when dereferencing iter->position
1114 reclaim
->generation
= iter
->generation
;
1120 if (prev
&& prev
!= root
)
1121 css_put(&prev
->css
);
1127 * mem_cgroup_iter_break - abort a hierarchy walk prematurely
1128 * @root: hierarchy root
1129 * @prev: last visited hierarchy member as returned by mem_cgroup_iter()
1131 void mem_cgroup_iter_break(struct mem_cgroup
*root
,
1132 struct mem_cgroup
*prev
)
1135 root
= root_mem_cgroup
;
1136 if (prev
&& prev
!= root
)
1137 css_put(&prev
->css
);
1141 * Iteration constructs for visiting all cgroups (under a tree). If
1142 * loops are exited prematurely (break), mem_cgroup_iter_break() must
1143 * be used for reference counting.
1145 #define for_each_mem_cgroup_tree(iter, root) \
1146 for (iter = mem_cgroup_iter(root, NULL, NULL); \
1148 iter = mem_cgroup_iter(root, iter, NULL))
1150 #define for_each_mem_cgroup(iter) \
1151 for (iter = mem_cgroup_iter(NULL, NULL, NULL); \
1153 iter = mem_cgroup_iter(NULL, iter, NULL))
1155 void __mem_cgroup_count_vm_event(struct mm_struct
*mm
, enum vm_event_item idx
)
1157 struct mem_cgroup
*memcg
;
1160 memcg
= mem_cgroup_from_task(rcu_dereference(mm
->owner
));
1161 if (unlikely(!memcg
))
1166 this_cpu_inc(memcg
->stat
->events
[MEM_CGROUP_EVENTS_PGFAULT
]);
1169 this_cpu_inc(memcg
->stat
->events
[MEM_CGROUP_EVENTS_PGMAJFAULT
]);
1177 EXPORT_SYMBOL(__mem_cgroup_count_vm_event
);
1180 * mem_cgroup_zone_lruvec - get the lru list vector for a zone and memcg
1181 * @zone: zone of the wanted lruvec
1182 * @memcg: memcg of the wanted lruvec
1184 * Returns the lru list vector holding pages for the given @zone and
1185 * @mem. This can be the global zone lruvec, if the memory controller
1188 struct lruvec
*mem_cgroup_zone_lruvec(struct zone
*zone
,
1189 struct mem_cgroup
*memcg
)
1191 struct mem_cgroup_per_zone
*mz
;
1192 struct lruvec
*lruvec
;
1194 if (mem_cgroup_disabled()) {
1195 lruvec
= &zone
->lruvec
;
1199 mz
= mem_cgroup_zone_zoneinfo(memcg
, zone
);
1200 lruvec
= &mz
->lruvec
;
1203 * Since a node can be onlined after the mem_cgroup was created,
1204 * we have to be prepared to initialize lruvec->zone here;
1205 * and if offlined then reonlined, we need to reinitialize it.
1207 if (unlikely(lruvec
->zone
!= zone
))
1208 lruvec
->zone
= zone
;
1213 * mem_cgroup_page_lruvec - return lruvec for isolating/putting an LRU page
1215 * @zone: zone of the page
1217 * This function is only safe when following the LRU page isolation
1218 * and putback protocol: the LRU lock must be held, and the page must
1219 * either be PageLRU() or the caller must have isolated/allocated it.
1221 struct lruvec
*mem_cgroup_page_lruvec(struct page
*page
, struct zone
*zone
)
1223 struct mem_cgroup_per_zone
*mz
;
1224 struct mem_cgroup
*memcg
;
1225 struct lruvec
*lruvec
;
1227 if (mem_cgroup_disabled()) {
1228 lruvec
= &zone
->lruvec
;
1232 memcg
= page
->mem_cgroup
;
1234 * Swapcache readahead pages are added to the LRU - and
1235 * possibly migrated - before they are charged.
1238 memcg
= root_mem_cgroup
;
1240 mz
= mem_cgroup_page_zoneinfo(memcg
, page
);
1241 lruvec
= &mz
->lruvec
;
1244 * Since a node can be onlined after the mem_cgroup was created,
1245 * we have to be prepared to initialize lruvec->zone here;
1246 * and if offlined then reonlined, we need to reinitialize it.
1248 if (unlikely(lruvec
->zone
!= zone
))
1249 lruvec
->zone
= zone
;
1254 * mem_cgroup_update_lru_size - account for adding or removing an lru page
1255 * @lruvec: mem_cgroup per zone lru vector
1256 * @lru: index of lru list the page is sitting on
1257 * @nr_pages: positive when adding or negative when removing
1259 * This function must be called when a page is added to or removed from an
1262 void mem_cgroup_update_lru_size(struct lruvec
*lruvec
, enum lru_list lru
,
1265 struct mem_cgroup_per_zone
*mz
;
1266 unsigned long *lru_size
;
1268 if (mem_cgroup_disabled())
1271 mz
= container_of(lruvec
, struct mem_cgroup_per_zone
, lruvec
);
1272 lru_size
= mz
->lru_size
+ lru
;
1273 *lru_size
+= nr_pages
;
1274 VM_BUG_ON((long)(*lru_size
) < 0);
1277 bool mem_cgroup_is_descendant(struct mem_cgroup
*memcg
, struct mem_cgroup
*root
)
1281 if (!root
->use_hierarchy
)
1283 return cgroup_is_descendant(memcg
->css
.cgroup
, root
->css
.cgroup
);
1286 bool task_in_mem_cgroup(struct task_struct
*task
, struct mem_cgroup
*memcg
)
1288 struct mem_cgroup
*task_memcg
;
1289 struct task_struct
*p
;
1292 p
= find_lock_task_mm(task
);
1294 task_memcg
= get_mem_cgroup_from_mm(p
->mm
);
1298 * All threads may have already detached their mm's, but the oom
1299 * killer still needs to detect if they have already been oom
1300 * killed to prevent needlessly killing additional tasks.
1303 task_memcg
= mem_cgroup_from_task(task
);
1304 css_get(&task_memcg
->css
);
1307 ret
= mem_cgroup_is_descendant(task_memcg
, memcg
);
1308 css_put(&task_memcg
->css
);
1312 int mem_cgroup_inactive_anon_is_low(struct lruvec
*lruvec
)
1314 unsigned long inactive_ratio
;
1315 unsigned long inactive
;
1316 unsigned long active
;
1319 inactive
= mem_cgroup_get_lru_size(lruvec
, LRU_INACTIVE_ANON
);
1320 active
= mem_cgroup_get_lru_size(lruvec
, LRU_ACTIVE_ANON
);
1322 gb
= (inactive
+ active
) >> (30 - PAGE_SHIFT
);
1324 inactive_ratio
= int_sqrt(10 * gb
);
1328 return inactive
* inactive_ratio
< active
;
1331 bool mem_cgroup_lruvec_online(struct lruvec
*lruvec
)
1333 struct mem_cgroup_per_zone
*mz
;
1334 struct mem_cgroup
*memcg
;
1336 if (mem_cgroup_disabled())
1339 mz
= container_of(lruvec
, struct mem_cgroup_per_zone
, lruvec
);
1342 return !!(memcg
->css
.flags
& CSS_ONLINE
);
1345 #define mem_cgroup_from_counter(counter, member) \
1346 container_of(counter, struct mem_cgroup, member)
1349 * mem_cgroup_margin - calculate chargeable space of a memory cgroup
1350 * @memcg: the memory cgroup
1352 * Returns the maximum amount of memory @mem can be charged with, in
1355 static unsigned long mem_cgroup_margin(struct mem_cgroup
*memcg
)
1357 unsigned long margin
= 0;
1358 unsigned long count
;
1359 unsigned long limit
;
1361 count
= page_counter_read(&memcg
->memory
);
1362 limit
= READ_ONCE(memcg
->memory
.limit
);
1364 margin
= limit
- count
;
1366 if (do_swap_account
) {
1367 count
= page_counter_read(&memcg
->memsw
);
1368 limit
= READ_ONCE(memcg
->memsw
.limit
);
1370 margin
= min(margin
, limit
- count
);
1376 int mem_cgroup_swappiness(struct mem_cgroup
*memcg
)
1379 if (mem_cgroup_disabled() || !memcg
->css
.parent
)
1380 return vm_swappiness
;
1382 return memcg
->swappiness
;
1386 * A routine for checking "mem" is under move_account() or not.
1388 * Checking a cgroup is mc.from or mc.to or under hierarchy of
1389 * moving cgroups. This is for waiting at high-memory pressure
1392 static bool mem_cgroup_under_move(struct mem_cgroup
*memcg
)
1394 struct mem_cgroup
*from
;
1395 struct mem_cgroup
*to
;
1398 * Unlike task_move routines, we access mc.to, mc.from not under
1399 * mutual exclusion by cgroup_mutex. Here, we take spinlock instead.
1401 spin_lock(&mc
.lock
);
1407 ret
= mem_cgroup_is_descendant(from
, memcg
) ||
1408 mem_cgroup_is_descendant(to
, memcg
);
1410 spin_unlock(&mc
.lock
);
1414 static bool mem_cgroup_wait_acct_move(struct mem_cgroup
*memcg
)
1416 if (mc
.moving_task
&& current
!= mc
.moving_task
) {
1417 if (mem_cgroup_under_move(memcg
)) {
1419 prepare_to_wait(&mc
.waitq
, &wait
, TASK_INTERRUPTIBLE
);
1420 /* moving charge context might have finished. */
1423 finish_wait(&mc
.waitq
, &wait
);
1430 #define K(x) ((x) << (PAGE_SHIFT-10))
1432 * mem_cgroup_print_oom_info: Print OOM information relevant to memory controller.
1433 * @memcg: The memory cgroup that went over limit
1434 * @p: Task that is going to be killed
1436 * NOTE: @memcg and @p's mem_cgroup can be different when hierarchy is
1439 void mem_cgroup_print_oom_info(struct mem_cgroup
*memcg
, struct task_struct
*p
)
1441 /* oom_info_lock ensures that parallel ooms do not interleave */
1442 static DEFINE_MUTEX(oom_info_lock
);
1443 struct mem_cgroup
*iter
;
1446 mutex_lock(&oom_info_lock
);
1450 pr_info("Task in ");
1451 pr_cont_cgroup_path(task_cgroup(p
, memory_cgrp_id
));
1452 pr_cont(" killed as a result of limit of ");
1454 pr_info("Memory limit reached of cgroup ");
1457 pr_cont_cgroup_path(memcg
->css
.cgroup
);
1462 pr_info("memory: usage %llukB, limit %llukB, failcnt %lu\n",
1463 K((u64
)page_counter_read(&memcg
->memory
)),
1464 K((u64
)memcg
->memory
.limit
), memcg
->memory
.failcnt
);
1465 pr_info("memory+swap: usage %llukB, limit %llukB, failcnt %lu\n",
1466 K((u64
)page_counter_read(&memcg
->memsw
)),
1467 K((u64
)memcg
->memsw
.limit
), memcg
->memsw
.failcnt
);
1468 pr_info("kmem: usage %llukB, limit %llukB, failcnt %lu\n",
1469 K((u64
)page_counter_read(&memcg
->kmem
)),
1470 K((u64
)memcg
->kmem
.limit
), memcg
->kmem
.failcnt
);
1472 for_each_mem_cgroup_tree(iter
, memcg
) {
1473 pr_info("Memory cgroup stats for ");
1474 pr_cont_cgroup_path(iter
->css
.cgroup
);
1477 for (i
= 0; i
< MEM_CGROUP_STAT_NSTATS
; i
++) {
1478 if (i
== MEM_CGROUP_STAT_SWAP
&& !do_swap_account
)
1480 pr_cont(" %s:%ldKB", mem_cgroup_stat_names
[i
],
1481 K(mem_cgroup_read_stat(iter
, i
)));
1484 for (i
= 0; i
< NR_LRU_LISTS
; i
++)
1485 pr_cont(" %s:%luKB", mem_cgroup_lru_names
[i
],
1486 K(mem_cgroup_nr_lru_pages(iter
, BIT(i
))));
1490 mutex_unlock(&oom_info_lock
);
1494 * This function returns the number of memcg under hierarchy tree. Returns
1495 * 1(self count) if no children.
1497 static int mem_cgroup_count_children(struct mem_cgroup
*memcg
)
1500 struct mem_cgroup
*iter
;
1502 for_each_mem_cgroup_tree(iter
, memcg
)
1508 * Return the memory (and swap, if configured) limit for a memcg.
1510 static unsigned long mem_cgroup_get_limit(struct mem_cgroup
*memcg
)
1512 unsigned long limit
;
1514 limit
= memcg
->memory
.limit
;
1515 if (mem_cgroup_swappiness(memcg
)) {
1516 unsigned long memsw_limit
;
1518 memsw_limit
= memcg
->memsw
.limit
;
1519 limit
= min(limit
+ total_swap_pages
, memsw_limit
);
1524 static void mem_cgroup_out_of_memory(struct mem_cgroup
*memcg
, gfp_t gfp_mask
,
1527 struct mem_cgroup
*iter
;
1528 unsigned long chosen_points
= 0;
1529 unsigned long totalpages
;
1530 unsigned int points
= 0;
1531 struct task_struct
*chosen
= NULL
;
1533 mutex_lock(&oom_lock
);
1536 * If current has a pending SIGKILL or is exiting, then automatically
1537 * select it. The goal is to allow it to allocate so that it may
1538 * quickly exit and free its memory.
1540 if (fatal_signal_pending(current
) || task_will_free_mem(current
)) {
1541 mark_oom_victim(current
);
1545 check_panic_on_oom(CONSTRAINT_MEMCG
, gfp_mask
, order
, NULL
, memcg
);
1546 totalpages
= mem_cgroup_get_limit(memcg
) ? : 1;
1547 for_each_mem_cgroup_tree(iter
, memcg
) {
1548 struct css_task_iter it
;
1549 struct task_struct
*task
;
1551 css_task_iter_start(&iter
->css
, &it
);
1552 while ((task
= css_task_iter_next(&it
))) {
1553 switch (oom_scan_process_thread(task
, totalpages
, NULL
,
1555 case OOM_SCAN_SELECT
:
1557 put_task_struct(chosen
);
1559 chosen_points
= ULONG_MAX
;
1560 get_task_struct(chosen
);
1562 case OOM_SCAN_CONTINUE
:
1564 case OOM_SCAN_ABORT
:
1565 css_task_iter_end(&it
);
1566 mem_cgroup_iter_break(memcg
, iter
);
1568 put_task_struct(chosen
);
1573 points
= oom_badness(task
, memcg
, NULL
, totalpages
);
1574 if (!points
|| points
< chosen_points
)
1576 /* Prefer thread group leaders for display purposes */
1577 if (points
== chosen_points
&&
1578 thread_group_leader(chosen
))
1582 put_task_struct(chosen
);
1584 chosen_points
= points
;
1585 get_task_struct(chosen
);
1587 css_task_iter_end(&it
);
1591 points
= chosen_points
* 1000 / totalpages
;
1592 oom_kill_process(chosen
, gfp_mask
, order
, points
, totalpages
,
1593 memcg
, NULL
, "Memory cgroup out of memory");
1596 mutex_unlock(&oom_lock
);
1599 #if MAX_NUMNODES > 1
1602 * test_mem_cgroup_node_reclaimable
1603 * @memcg: the target memcg
1604 * @nid: the node ID to be checked.
1605 * @noswap : specify true here if the user wants flle only information.
1607 * This function returns whether the specified memcg contains any
1608 * reclaimable pages on a node. Returns true if there are any reclaimable
1609 * pages in the node.
1611 static bool test_mem_cgroup_node_reclaimable(struct mem_cgroup
*memcg
,
1612 int nid
, bool noswap
)
1614 if (mem_cgroup_node_nr_lru_pages(memcg
, nid
, LRU_ALL_FILE
))
1616 if (noswap
|| !total_swap_pages
)
1618 if (mem_cgroup_node_nr_lru_pages(memcg
, nid
, LRU_ALL_ANON
))
1625 * Always updating the nodemask is not very good - even if we have an empty
1626 * list or the wrong list here, we can start from some node and traverse all
1627 * nodes based on the zonelist. So update the list loosely once per 10 secs.
1630 static void mem_cgroup_may_update_nodemask(struct mem_cgroup
*memcg
)
1634 * numainfo_events > 0 means there was at least NUMAINFO_EVENTS_TARGET
1635 * pagein/pageout changes since the last update.
1637 if (!atomic_read(&memcg
->numainfo_events
))
1639 if (atomic_inc_return(&memcg
->numainfo_updating
) > 1)
1642 /* make a nodemask where this memcg uses memory from */
1643 memcg
->scan_nodes
= node_states
[N_MEMORY
];
1645 for_each_node_mask(nid
, node_states
[N_MEMORY
]) {
1647 if (!test_mem_cgroup_node_reclaimable(memcg
, nid
, false))
1648 node_clear(nid
, memcg
->scan_nodes
);
1651 atomic_set(&memcg
->numainfo_events
, 0);
1652 atomic_set(&memcg
->numainfo_updating
, 0);
1656 * Selecting a node where we start reclaim from. Because what we need is just
1657 * reducing usage counter, start from anywhere is O,K. Considering
1658 * memory reclaim from current node, there are pros. and cons.
1660 * Freeing memory from current node means freeing memory from a node which
1661 * we'll use or we've used. So, it may make LRU bad. And if several threads
1662 * hit limits, it will see a contention on a node. But freeing from remote
1663 * node means more costs for memory reclaim because of memory latency.
1665 * Now, we use round-robin. Better algorithm is welcomed.
1667 int mem_cgroup_select_victim_node(struct mem_cgroup
*memcg
)
1671 mem_cgroup_may_update_nodemask(memcg
);
1672 node
= memcg
->last_scanned_node
;
1674 node
= next_node(node
, memcg
->scan_nodes
);
1675 if (node
== MAX_NUMNODES
)
1676 node
= first_node(memcg
->scan_nodes
);
1678 * We call this when we hit limit, not when pages are added to LRU.
1679 * No LRU may hold pages because all pages are UNEVICTABLE or
1680 * memcg is too small and all pages are not on LRU. In that case,
1681 * we use curret node.
1683 if (unlikely(node
== MAX_NUMNODES
))
1684 node
= numa_node_id();
1686 memcg
->last_scanned_node
= node
;
1690 int mem_cgroup_select_victim_node(struct mem_cgroup
*memcg
)
1696 static int mem_cgroup_soft_reclaim(struct mem_cgroup
*root_memcg
,
1699 unsigned long *total_scanned
)
1701 struct mem_cgroup
*victim
= NULL
;
1704 unsigned long excess
;
1705 unsigned long nr_scanned
;
1706 struct mem_cgroup_reclaim_cookie reclaim
= {
1711 excess
= soft_limit_excess(root_memcg
);
1714 victim
= mem_cgroup_iter(root_memcg
, victim
, &reclaim
);
1719 * If we have not been able to reclaim
1720 * anything, it might because there are
1721 * no reclaimable pages under this hierarchy
1726 * We want to do more targeted reclaim.
1727 * excess >> 2 is not to excessive so as to
1728 * reclaim too much, nor too less that we keep
1729 * coming back to reclaim from this cgroup
1731 if (total
>= (excess
>> 2) ||
1732 (loop
> MEM_CGROUP_MAX_RECLAIM_LOOPS
))
1737 total
+= mem_cgroup_shrink_node_zone(victim
, gfp_mask
, false,
1739 *total_scanned
+= nr_scanned
;
1740 if (!soft_limit_excess(root_memcg
))
1743 mem_cgroup_iter_break(root_memcg
, victim
);
1747 #ifdef CONFIG_LOCKDEP
1748 static struct lockdep_map memcg_oom_lock_dep_map
= {
1749 .name
= "memcg_oom_lock",
1753 static DEFINE_SPINLOCK(memcg_oom_lock
);
1756 * Check OOM-Killer is already running under our hierarchy.
1757 * If someone is running, return false.
1759 static bool mem_cgroup_oom_trylock(struct mem_cgroup
*memcg
)
1761 struct mem_cgroup
*iter
, *failed
= NULL
;
1763 spin_lock(&memcg_oom_lock
);
1765 for_each_mem_cgroup_tree(iter
, memcg
) {
1766 if (iter
->oom_lock
) {
1768 * this subtree of our hierarchy is already locked
1769 * so we cannot give a lock.
1772 mem_cgroup_iter_break(memcg
, iter
);
1775 iter
->oom_lock
= true;
1780 * OK, we failed to lock the whole subtree so we have
1781 * to clean up what we set up to the failing subtree
1783 for_each_mem_cgroup_tree(iter
, memcg
) {
1784 if (iter
== failed
) {
1785 mem_cgroup_iter_break(memcg
, iter
);
1788 iter
->oom_lock
= false;
1791 mutex_acquire(&memcg_oom_lock_dep_map
, 0, 1, _RET_IP_
);
1793 spin_unlock(&memcg_oom_lock
);
1798 static void mem_cgroup_oom_unlock(struct mem_cgroup
*memcg
)
1800 struct mem_cgroup
*iter
;
1802 spin_lock(&memcg_oom_lock
);
1803 mutex_release(&memcg_oom_lock_dep_map
, 1, _RET_IP_
);
1804 for_each_mem_cgroup_tree(iter
, memcg
)
1805 iter
->oom_lock
= false;
1806 spin_unlock(&memcg_oom_lock
);
1809 static void mem_cgroup_mark_under_oom(struct mem_cgroup
*memcg
)
1811 struct mem_cgroup
*iter
;
1813 for_each_mem_cgroup_tree(iter
, memcg
)
1814 atomic_inc(&iter
->under_oom
);
1817 static void mem_cgroup_unmark_under_oom(struct mem_cgroup
*memcg
)
1819 struct mem_cgroup
*iter
;
1822 * When a new child is created while the hierarchy is under oom,
1823 * mem_cgroup_oom_lock() may not be called. We have to use
1824 * atomic_add_unless() here.
1826 for_each_mem_cgroup_tree(iter
, memcg
)
1827 atomic_add_unless(&iter
->under_oom
, -1, 0);
1830 static DECLARE_WAIT_QUEUE_HEAD(memcg_oom_waitq
);
1832 struct oom_wait_info
{
1833 struct mem_cgroup
*memcg
;
1837 static int memcg_oom_wake_function(wait_queue_t
*wait
,
1838 unsigned mode
, int sync
, void *arg
)
1840 struct mem_cgroup
*wake_memcg
= (struct mem_cgroup
*)arg
;
1841 struct mem_cgroup
*oom_wait_memcg
;
1842 struct oom_wait_info
*oom_wait_info
;
1844 oom_wait_info
= container_of(wait
, struct oom_wait_info
, wait
);
1845 oom_wait_memcg
= oom_wait_info
->memcg
;
1847 if (!mem_cgroup_is_descendant(wake_memcg
, oom_wait_memcg
) &&
1848 !mem_cgroup_is_descendant(oom_wait_memcg
, wake_memcg
))
1850 return autoremove_wake_function(wait
, mode
, sync
, arg
);
1853 static void memcg_wakeup_oom(struct mem_cgroup
*memcg
)
1855 atomic_inc(&memcg
->oom_wakeups
);
1856 /* for filtering, pass "memcg" as argument. */
1857 __wake_up(&memcg_oom_waitq
, TASK_NORMAL
, 0, memcg
);
1860 static void memcg_oom_recover(struct mem_cgroup
*memcg
)
1862 if (memcg
&& atomic_read(&memcg
->under_oom
))
1863 memcg_wakeup_oom(memcg
);
1866 static void mem_cgroup_oom(struct mem_cgroup
*memcg
, gfp_t mask
, int order
)
1868 if (!current
->memcg_oom
.may_oom
)
1871 * We are in the middle of the charge context here, so we
1872 * don't want to block when potentially sitting on a callstack
1873 * that holds all kinds of filesystem and mm locks.
1875 * Also, the caller may handle a failed allocation gracefully
1876 * (like optional page cache readahead) and so an OOM killer
1877 * invocation might not even be necessary.
1879 * That's why we don't do anything here except remember the
1880 * OOM context and then deal with it at the end of the page
1881 * fault when the stack is unwound, the locks are released,
1882 * and when we know whether the fault was overall successful.
1884 css_get(&memcg
->css
);
1885 current
->memcg_oom
.memcg
= memcg
;
1886 current
->memcg_oom
.gfp_mask
= mask
;
1887 current
->memcg_oom
.order
= order
;
1891 * mem_cgroup_oom_synchronize - complete memcg OOM handling
1892 * @handle: actually kill/wait or just clean up the OOM state
1894 * This has to be called at the end of a page fault if the memcg OOM
1895 * handler was enabled.
1897 * Memcg supports userspace OOM handling where failed allocations must
1898 * sleep on a waitqueue until the userspace task resolves the
1899 * situation. Sleeping directly in the charge context with all kinds
1900 * of locks held is not a good idea, instead we remember an OOM state
1901 * in the task and mem_cgroup_oom_synchronize() has to be called at
1902 * the end of the page fault to complete the OOM handling.
1904 * Returns %true if an ongoing memcg OOM situation was detected and
1905 * completed, %false otherwise.
1907 bool mem_cgroup_oom_synchronize(bool handle
)
1909 struct mem_cgroup
*memcg
= current
->memcg_oom
.memcg
;
1910 struct oom_wait_info owait
;
1913 /* OOM is global, do not handle */
1917 if (!handle
|| oom_killer_disabled
)
1920 owait
.memcg
= memcg
;
1921 owait
.wait
.flags
= 0;
1922 owait
.wait
.func
= memcg_oom_wake_function
;
1923 owait
.wait
.private = current
;
1924 INIT_LIST_HEAD(&owait
.wait
.task_list
);
1926 prepare_to_wait(&memcg_oom_waitq
, &owait
.wait
, TASK_KILLABLE
);
1927 mem_cgroup_mark_under_oom(memcg
);
1929 locked
= mem_cgroup_oom_trylock(memcg
);
1932 mem_cgroup_oom_notify(memcg
);
1934 if (locked
&& !memcg
->oom_kill_disable
) {
1935 mem_cgroup_unmark_under_oom(memcg
);
1936 finish_wait(&memcg_oom_waitq
, &owait
.wait
);
1937 mem_cgroup_out_of_memory(memcg
, current
->memcg_oom
.gfp_mask
,
1938 current
->memcg_oom
.order
);
1941 mem_cgroup_unmark_under_oom(memcg
);
1942 finish_wait(&memcg_oom_waitq
, &owait
.wait
);
1946 mem_cgroup_oom_unlock(memcg
);
1948 * There is no guarantee that an OOM-lock contender
1949 * sees the wakeups triggered by the OOM kill
1950 * uncharges. Wake any sleepers explicitely.
1952 memcg_oom_recover(memcg
);
1955 current
->memcg_oom
.memcg
= NULL
;
1956 css_put(&memcg
->css
);
1961 * mem_cgroup_begin_page_stat - begin a page state statistics transaction
1962 * @page: page that is going to change accounted state
1964 * This function must mark the beginning of an accounted page state
1965 * change to prevent double accounting when the page is concurrently
1966 * being moved to another memcg:
1968 * memcg = mem_cgroup_begin_page_stat(page);
1969 * if (TestClearPageState(page))
1970 * mem_cgroup_update_page_stat(memcg, state, -1);
1971 * mem_cgroup_end_page_stat(memcg);
1973 struct mem_cgroup
*mem_cgroup_begin_page_stat(struct page
*page
)
1975 struct mem_cgroup
*memcg
;
1976 unsigned long flags
;
1979 * The RCU lock is held throughout the transaction. The fast
1980 * path can get away without acquiring the memcg->move_lock
1981 * because page moving starts with an RCU grace period.
1983 * The RCU lock also protects the memcg from being freed when
1984 * the page state that is going to change is the only thing
1985 * preventing the page from being uncharged.
1986 * E.g. end-writeback clearing PageWriteback(), which allows
1987 * migration to go ahead and uncharge the page before the
1988 * account transaction might be complete.
1992 if (mem_cgroup_disabled())
1995 memcg
= page
->mem_cgroup
;
1996 if (unlikely(!memcg
))
1999 if (atomic_read(&memcg
->moving_account
) <= 0)
2002 spin_lock_irqsave(&memcg
->move_lock
, flags
);
2003 if (memcg
!= page
->mem_cgroup
) {
2004 spin_unlock_irqrestore(&memcg
->move_lock
, flags
);
2009 * When charge migration first begins, we can have locked and
2010 * unlocked page stat updates happening concurrently. Track
2011 * the task who has the lock for mem_cgroup_end_page_stat().
2013 memcg
->move_lock_task
= current
;
2014 memcg
->move_lock_flags
= flags
;
2020 * mem_cgroup_end_page_stat - finish a page state statistics transaction
2021 * @memcg: the memcg that was accounted against
2023 void mem_cgroup_end_page_stat(struct mem_cgroup
*memcg
)
2025 if (memcg
&& memcg
->move_lock_task
== current
) {
2026 unsigned long flags
= memcg
->move_lock_flags
;
2028 memcg
->move_lock_task
= NULL
;
2029 memcg
->move_lock_flags
= 0;
2031 spin_unlock_irqrestore(&memcg
->move_lock
, flags
);
2038 * mem_cgroup_update_page_stat - update page state statistics
2039 * @memcg: memcg to account against
2040 * @idx: page state item to account
2041 * @val: number of pages (positive or negative)
2043 * See mem_cgroup_begin_page_stat() for locking requirements.
2045 void mem_cgroup_update_page_stat(struct mem_cgroup
*memcg
,
2046 enum mem_cgroup_stat_index idx
, int val
)
2048 VM_BUG_ON(!rcu_read_lock_held());
2051 this_cpu_add(memcg
->stat
->count
[idx
], val
);
2055 * size of first charge trial. "32" comes from vmscan.c's magic value.
2056 * TODO: maybe necessary to use big numbers in big irons.
2058 #define CHARGE_BATCH 32U
2059 struct memcg_stock_pcp
{
2060 struct mem_cgroup
*cached
; /* this never be root cgroup */
2061 unsigned int nr_pages
;
2062 struct work_struct work
;
2063 unsigned long flags
;
2064 #define FLUSHING_CACHED_CHARGE 0
2066 static DEFINE_PER_CPU(struct memcg_stock_pcp
, memcg_stock
);
2067 static DEFINE_MUTEX(percpu_charge_mutex
);
2070 * consume_stock: Try to consume stocked charge on this cpu.
2071 * @memcg: memcg to consume from.
2072 * @nr_pages: how many pages to charge.
2074 * The charges will only happen if @memcg matches the current cpu's memcg
2075 * stock, and at least @nr_pages are available in that stock. Failure to
2076 * service an allocation will refill the stock.
2078 * returns true if successful, false otherwise.
2080 static bool consume_stock(struct mem_cgroup
*memcg
, unsigned int nr_pages
)
2082 struct memcg_stock_pcp
*stock
;
2085 if (nr_pages
> CHARGE_BATCH
)
2088 stock
= &get_cpu_var(memcg_stock
);
2089 if (memcg
== stock
->cached
&& stock
->nr_pages
>= nr_pages
) {
2090 stock
->nr_pages
-= nr_pages
;
2093 put_cpu_var(memcg_stock
);
2098 * Returns stocks cached in percpu and reset cached information.
2100 static void drain_stock(struct memcg_stock_pcp
*stock
)
2102 struct mem_cgroup
*old
= stock
->cached
;
2104 if (stock
->nr_pages
) {
2105 page_counter_uncharge(&old
->memory
, stock
->nr_pages
);
2106 if (do_swap_account
)
2107 page_counter_uncharge(&old
->memsw
, stock
->nr_pages
);
2108 css_put_many(&old
->css
, stock
->nr_pages
);
2109 stock
->nr_pages
= 0;
2111 stock
->cached
= NULL
;
2115 * This must be called under preempt disabled or must be called by
2116 * a thread which is pinned to local cpu.
2118 static void drain_local_stock(struct work_struct
*dummy
)
2120 struct memcg_stock_pcp
*stock
= this_cpu_ptr(&memcg_stock
);
2122 clear_bit(FLUSHING_CACHED_CHARGE
, &stock
->flags
);
2126 * Cache charges(val) to local per_cpu area.
2127 * This will be consumed by consume_stock() function, later.
2129 static void refill_stock(struct mem_cgroup
*memcg
, unsigned int nr_pages
)
2131 struct memcg_stock_pcp
*stock
= &get_cpu_var(memcg_stock
);
2133 if (stock
->cached
!= memcg
) { /* reset if necessary */
2135 stock
->cached
= memcg
;
2137 stock
->nr_pages
+= nr_pages
;
2138 put_cpu_var(memcg_stock
);
2142 * Drains all per-CPU charge caches for given root_memcg resp. subtree
2143 * of the hierarchy under it.
2145 static void drain_all_stock(struct mem_cgroup
*root_memcg
)
2149 /* If someone's already draining, avoid adding running more workers. */
2150 if (!mutex_trylock(&percpu_charge_mutex
))
2152 /* Notify other cpus that system-wide "drain" is running */
2155 for_each_online_cpu(cpu
) {
2156 struct memcg_stock_pcp
*stock
= &per_cpu(memcg_stock
, cpu
);
2157 struct mem_cgroup
*memcg
;
2159 memcg
= stock
->cached
;
2160 if (!memcg
|| !stock
->nr_pages
)
2162 if (!mem_cgroup_is_descendant(memcg
, root_memcg
))
2164 if (!test_and_set_bit(FLUSHING_CACHED_CHARGE
, &stock
->flags
)) {
2166 drain_local_stock(&stock
->work
);
2168 schedule_work_on(cpu
, &stock
->work
);
2173 mutex_unlock(&percpu_charge_mutex
);
2177 * This function drains percpu counter value from DEAD cpu and
2178 * move it to local cpu. Note that this function can be preempted.
2180 static void mem_cgroup_drain_pcp_counter(struct mem_cgroup
*memcg
, int cpu
)
2184 spin_lock(&memcg
->pcp_counter_lock
);
2185 for (i
= 0; i
< MEM_CGROUP_STAT_NSTATS
; i
++) {
2186 long x
= per_cpu(memcg
->stat
->count
[i
], cpu
);
2188 per_cpu(memcg
->stat
->count
[i
], cpu
) = 0;
2189 memcg
->nocpu_base
.count
[i
] += x
;
2191 for (i
= 0; i
< MEM_CGROUP_EVENTS_NSTATS
; i
++) {
2192 unsigned long x
= per_cpu(memcg
->stat
->events
[i
], cpu
);
2194 per_cpu(memcg
->stat
->events
[i
], cpu
) = 0;
2195 memcg
->nocpu_base
.events
[i
] += x
;
2197 spin_unlock(&memcg
->pcp_counter_lock
);
2200 static int memcg_cpu_hotplug_callback(struct notifier_block
*nb
,
2201 unsigned long action
,
2204 int cpu
= (unsigned long)hcpu
;
2205 struct memcg_stock_pcp
*stock
;
2206 struct mem_cgroup
*iter
;
2208 if (action
== CPU_ONLINE
)
2211 if (action
!= CPU_DEAD
&& action
!= CPU_DEAD_FROZEN
)
2214 for_each_mem_cgroup(iter
)
2215 mem_cgroup_drain_pcp_counter(iter
, cpu
);
2217 stock
= &per_cpu(memcg_stock
, cpu
);
2222 static int try_charge(struct mem_cgroup
*memcg
, gfp_t gfp_mask
,
2223 unsigned int nr_pages
)
2225 unsigned int batch
= max(CHARGE_BATCH
, nr_pages
);
2226 int nr_retries
= MEM_CGROUP_RECLAIM_RETRIES
;
2227 struct mem_cgroup
*mem_over_limit
;
2228 struct page_counter
*counter
;
2229 unsigned long nr_reclaimed
;
2230 bool may_swap
= true;
2231 bool drained
= false;
2234 if (mem_cgroup_is_root(memcg
))
2237 if (consume_stock(memcg
, nr_pages
))
2240 if (!do_swap_account
||
2241 !page_counter_try_charge(&memcg
->memsw
, batch
, &counter
)) {
2242 if (!page_counter_try_charge(&memcg
->memory
, batch
, &counter
))
2244 if (do_swap_account
)
2245 page_counter_uncharge(&memcg
->memsw
, batch
);
2246 mem_over_limit
= mem_cgroup_from_counter(counter
, memory
);
2248 mem_over_limit
= mem_cgroup_from_counter(counter
, memsw
);
2252 if (batch
> nr_pages
) {
2258 * Unlike in global OOM situations, memcg is not in a physical
2259 * memory shortage. Allow dying and OOM-killed tasks to
2260 * bypass the last charges so that they can exit quickly and
2261 * free their memory.
2263 if (unlikely(test_thread_flag(TIF_MEMDIE
) ||
2264 fatal_signal_pending(current
) ||
2265 current
->flags
& PF_EXITING
))
2268 if (unlikely(task_in_memcg_oom(current
)))
2271 if (!(gfp_mask
& __GFP_WAIT
))
2274 mem_cgroup_events(mem_over_limit
, MEMCG_MAX
, 1);
2276 nr_reclaimed
= try_to_free_mem_cgroup_pages(mem_over_limit
, nr_pages
,
2277 gfp_mask
, may_swap
);
2279 if (mem_cgroup_margin(mem_over_limit
) >= nr_pages
)
2283 drain_all_stock(mem_over_limit
);
2288 if (gfp_mask
& __GFP_NORETRY
)
2291 * Even though the limit is exceeded at this point, reclaim
2292 * may have been able to free some pages. Retry the charge
2293 * before killing the task.
2295 * Only for regular pages, though: huge pages are rather
2296 * unlikely to succeed so close to the limit, and we fall back
2297 * to regular pages anyway in case of failure.
2299 if (nr_reclaimed
&& nr_pages
<= (1 << PAGE_ALLOC_COSTLY_ORDER
))
2302 * At task move, charge accounts can be doubly counted. So, it's
2303 * better to wait until the end of task_move if something is going on.
2305 if (mem_cgroup_wait_acct_move(mem_over_limit
))
2311 if (gfp_mask
& __GFP_NOFAIL
)
2314 if (fatal_signal_pending(current
))
2317 mem_cgroup_events(mem_over_limit
, MEMCG_OOM
, 1);
2319 mem_cgroup_oom(mem_over_limit
, gfp_mask
, get_order(nr_pages
));
2321 if (!(gfp_mask
& __GFP_NOFAIL
))
2327 css_get_many(&memcg
->css
, batch
);
2328 if (batch
> nr_pages
)
2329 refill_stock(memcg
, batch
- nr_pages
);
2330 if (!(gfp_mask
& __GFP_WAIT
))
2333 * If the hierarchy is above the normal consumption range,
2334 * make the charging task trim their excess contribution.
2337 if (page_counter_read(&memcg
->memory
) <= memcg
->high
)
2339 mem_cgroup_events(memcg
, MEMCG_HIGH
, 1);
2340 try_to_free_mem_cgroup_pages(memcg
, nr_pages
, gfp_mask
, true);
2341 } while ((memcg
= parent_mem_cgroup(memcg
)));
2346 static void cancel_charge(struct mem_cgroup
*memcg
, unsigned int nr_pages
)
2348 if (mem_cgroup_is_root(memcg
))
2351 page_counter_uncharge(&memcg
->memory
, nr_pages
);
2352 if (do_swap_account
)
2353 page_counter_uncharge(&memcg
->memsw
, nr_pages
);
2355 css_put_many(&memcg
->css
, nr_pages
);
2359 * try_get_mem_cgroup_from_page - look up page's memcg association
2362 * Look up, get a css reference, and return the memcg that owns @page.
2364 * The page must be locked to prevent racing with swap-in and page
2365 * cache charges. If coming from an unlocked page table, the caller
2366 * must ensure the page is on the LRU or this can race with charging.
2368 struct mem_cgroup
*try_get_mem_cgroup_from_page(struct page
*page
)
2370 struct mem_cgroup
*memcg
;
2374 VM_BUG_ON_PAGE(!PageLocked(page
), page
);
2376 memcg
= page
->mem_cgroup
;
2378 if (!css_tryget_online(&memcg
->css
))
2380 } else if (PageSwapCache(page
)) {
2381 ent
.val
= page_private(page
);
2382 id
= lookup_swap_cgroup_id(ent
);
2384 memcg
= mem_cgroup_from_id(id
);
2385 if (memcg
&& !css_tryget_online(&memcg
->css
))
2392 static void lock_page_lru(struct page
*page
, int *isolated
)
2394 struct zone
*zone
= page_zone(page
);
2396 spin_lock_irq(&zone
->lru_lock
);
2397 if (PageLRU(page
)) {
2398 struct lruvec
*lruvec
;
2400 lruvec
= mem_cgroup_page_lruvec(page
, zone
);
2402 del_page_from_lru_list(page
, lruvec
, page_lru(page
));
2408 static void unlock_page_lru(struct page
*page
, int isolated
)
2410 struct zone
*zone
= page_zone(page
);
2413 struct lruvec
*lruvec
;
2415 lruvec
= mem_cgroup_page_lruvec(page
, zone
);
2416 VM_BUG_ON_PAGE(PageLRU(page
), page
);
2418 add_page_to_lru_list(page
, lruvec
, page_lru(page
));
2420 spin_unlock_irq(&zone
->lru_lock
);
2423 static void commit_charge(struct page
*page
, struct mem_cgroup
*memcg
,
2428 VM_BUG_ON_PAGE(page
->mem_cgroup
, page
);
2431 * In some cases, SwapCache and FUSE(splice_buf->radixtree), the page
2432 * may already be on some other mem_cgroup's LRU. Take care of it.
2435 lock_page_lru(page
, &isolated
);
2438 * Nobody should be changing or seriously looking at
2439 * page->mem_cgroup at this point:
2441 * - the page is uncharged
2443 * - the page is off-LRU
2445 * - an anonymous fault has exclusive page access, except for
2446 * a locked page table
2448 * - a page cache insertion, a swapin fault, or a migration
2449 * have the page locked
2451 page
->mem_cgroup
= memcg
;
2454 unlock_page_lru(page
, isolated
);
2457 #ifdef CONFIG_MEMCG_KMEM
2458 int memcg_charge_kmem(struct mem_cgroup
*memcg
, gfp_t gfp
,
2459 unsigned long nr_pages
)
2461 struct page_counter
*counter
;
2464 ret
= page_counter_try_charge(&memcg
->kmem
, nr_pages
, &counter
);
2468 ret
= try_charge(memcg
, gfp
, nr_pages
);
2469 if (ret
== -EINTR
) {
2471 * try_charge() chose to bypass to root due to OOM kill or
2472 * fatal signal. Since our only options are to either fail
2473 * the allocation or charge it to this cgroup, do it as a
2474 * temporary condition. But we can't fail. From a kmem/slab
2475 * perspective, the cache has already been selected, by
2476 * mem_cgroup_kmem_get_cache(), so it is too late to change
2479 * This condition will only trigger if the task entered
2480 * memcg_charge_kmem in a sane state, but was OOM-killed
2481 * during try_charge() above. Tasks that were already dying
2482 * when the allocation triggers should have been already
2483 * directed to the root cgroup in memcontrol.h
2485 page_counter_charge(&memcg
->memory
, nr_pages
);
2486 if (do_swap_account
)
2487 page_counter_charge(&memcg
->memsw
, nr_pages
);
2488 css_get_many(&memcg
->css
, nr_pages
);
2491 page_counter_uncharge(&memcg
->kmem
, nr_pages
);
2496 void memcg_uncharge_kmem(struct mem_cgroup
*memcg
, unsigned long nr_pages
)
2498 page_counter_uncharge(&memcg
->memory
, nr_pages
);
2499 if (do_swap_account
)
2500 page_counter_uncharge(&memcg
->memsw
, nr_pages
);
2502 page_counter_uncharge(&memcg
->kmem
, nr_pages
);
2504 css_put_many(&memcg
->css
, nr_pages
);
2508 * helper for acessing a memcg's index. It will be used as an index in the
2509 * child cache array in kmem_cache, and also to derive its name. This function
2510 * will return -1 when this is not a kmem-limited memcg.
2512 int memcg_cache_id(struct mem_cgroup
*memcg
)
2514 return memcg
? memcg
->kmemcg_id
: -1;
2517 static int memcg_alloc_cache_id(void)
2522 id
= ida_simple_get(&memcg_cache_ida
,
2523 0, MEMCG_CACHES_MAX_SIZE
, GFP_KERNEL
);
2527 if (id
< memcg_nr_cache_ids
)
2531 * There's no space for the new id in memcg_caches arrays,
2532 * so we have to grow them.
2534 down_write(&memcg_cache_ids_sem
);
2536 size
= 2 * (id
+ 1);
2537 if (size
< MEMCG_CACHES_MIN_SIZE
)
2538 size
= MEMCG_CACHES_MIN_SIZE
;
2539 else if (size
> MEMCG_CACHES_MAX_SIZE
)
2540 size
= MEMCG_CACHES_MAX_SIZE
;
2542 err
= memcg_update_all_caches(size
);
2544 err
= memcg_update_all_list_lrus(size
);
2546 memcg_nr_cache_ids
= size
;
2548 up_write(&memcg_cache_ids_sem
);
2551 ida_simple_remove(&memcg_cache_ida
, id
);
2557 static void memcg_free_cache_id(int id
)
2559 ida_simple_remove(&memcg_cache_ida
, id
);
2562 struct memcg_kmem_cache_create_work
{
2563 struct mem_cgroup
*memcg
;
2564 struct kmem_cache
*cachep
;
2565 struct work_struct work
;
2568 static void memcg_kmem_cache_create_func(struct work_struct
*w
)
2570 struct memcg_kmem_cache_create_work
*cw
=
2571 container_of(w
, struct memcg_kmem_cache_create_work
, work
);
2572 struct mem_cgroup
*memcg
= cw
->memcg
;
2573 struct kmem_cache
*cachep
= cw
->cachep
;
2575 memcg_create_kmem_cache(memcg
, cachep
);
2577 css_put(&memcg
->css
);
2582 * Enqueue the creation of a per-memcg kmem_cache.
2584 static void __memcg_schedule_kmem_cache_create(struct mem_cgroup
*memcg
,
2585 struct kmem_cache
*cachep
)
2587 struct memcg_kmem_cache_create_work
*cw
;
2589 cw
= kmalloc(sizeof(*cw
), GFP_NOWAIT
);
2593 css_get(&memcg
->css
);
2596 cw
->cachep
= cachep
;
2597 INIT_WORK(&cw
->work
, memcg_kmem_cache_create_func
);
2599 schedule_work(&cw
->work
);
2602 static void memcg_schedule_kmem_cache_create(struct mem_cgroup
*memcg
,
2603 struct kmem_cache
*cachep
)
2606 * We need to stop accounting when we kmalloc, because if the
2607 * corresponding kmalloc cache is not yet created, the first allocation
2608 * in __memcg_schedule_kmem_cache_create will recurse.
2610 * However, it is better to enclose the whole function. Depending on
2611 * the debugging options enabled, INIT_WORK(), for instance, can
2612 * trigger an allocation. This too, will make us recurse. Because at
2613 * this point we can't allow ourselves back into memcg_kmem_get_cache,
2614 * the safest choice is to do it like this, wrapping the whole function.
2616 current
->memcg_kmem_skip_account
= 1;
2617 __memcg_schedule_kmem_cache_create(memcg
, cachep
);
2618 current
->memcg_kmem_skip_account
= 0;
2622 * Return the kmem_cache we're supposed to use for a slab allocation.
2623 * We try to use the current memcg's version of the cache.
2625 * If the cache does not exist yet, if we are the first user of it,
2626 * we either create it immediately, if possible, or create it asynchronously
2628 * In the latter case, we will let the current allocation go through with
2629 * the original cache.
2631 * Can't be called in interrupt context or from kernel threads.
2632 * This function needs to be called with rcu_read_lock() held.
2634 struct kmem_cache
*__memcg_kmem_get_cache(struct kmem_cache
*cachep
)
2636 struct mem_cgroup
*memcg
;
2637 struct kmem_cache
*memcg_cachep
;
2640 VM_BUG_ON(!is_root_cache(cachep
));
2642 if (current
->memcg_kmem_skip_account
)
2645 memcg
= get_mem_cgroup_from_mm(current
->mm
);
2646 kmemcg_id
= READ_ONCE(memcg
->kmemcg_id
);
2650 memcg_cachep
= cache_from_memcg_idx(cachep
, kmemcg_id
);
2651 if (likely(memcg_cachep
))
2652 return memcg_cachep
;
2655 * If we are in a safe context (can wait, and not in interrupt
2656 * context), we could be be predictable and return right away.
2657 * This would guarantee that the allocation being performed
2658 * already belongs in the new cache.
2660 * However, there are some clashes that can arrive from locking.
2661 * For instance, because we acquire the slab_mutex while doing
2662 * memcg_create_kmem_cache, this means no further allocation
2663 * could happen with the slab_mutex held. So it's better to
2666 memcg_schedule_kmem_cache_create(memcg
, cachep
);
2668 css_put(&memcg
->css
);
2672 void __memcg_kmem_put_cache(struct kmem_cache
*cachep
)
2674 if (!is_root_cache(cachep
))
2675 css_put(&cachep
->memcg_params
.memcg
->css
);
2679 * We need to verify if the allocation against current->mm->owner's memcg is
2680 * possible for the given order. But the page is not allocated yet, so we'll
2681 * need a further commit step to do the final arrangements.
2683 * It is possible for the task to switch cgroups in this mean time, so at
2684 * commit time, we can't rely on task conversion any longer. We'll then use
2685 * the handle argument to return to the caller which cgroup we should commit
2686 * against. We could also return the memcg directly and avoid the pointer
2687 * passing, but a boolean return value gives better semantics considering
2688 * the compiled-out case as well.
2690 * Returning true means the allocation is possible.
2693 __memcg_kmem_newpage_charge(gfp_t gfp
, struct mem_cgroup
**_memcg
, int order
)
2695 struct mem_cgroup
*memcg
;
2700 memcg
= get_mem_cgroup_from_mm(current
->mm
);
2702 if (!memcg_kmem_is_active(memcg
)) {
2703 css_put(&memcg
->css
);
2707 ret
= memcg_charge_kmem(memcg
, gfp
, 1 << order
);
2711 css_put(&memcg
->css
);
2715 void __memcg_kmem_commit_charge(struct page
*page
, struct mem_cgroup
*memcg
,
2718 VM_BUG_ON(mem_cgroup_is_root(memcg
));
2720 /* The page allocation failed. Revert */
2722 memcg_uncharge_kmem(memcg
, 1 << order
);
2725 page
->mem_cgroup
= memcg
;
2728 void __memcg_kmem_uncharge_pages(struct page
*page
, int order
)
2730 struct mem_cgroup
*memcg
= page
->mem_cgroup
;
2735 VM_BUG_ON_PAGE(mem_cgroup_is_root(memcg
), page
);
2737 memcg_uncharge_kmem(memcg
, 1 << order
);
2738 page
->mem_cgroup
= NULL
;
2741 struct mem_cgroup
*__mem_cgroup_from_kmem(void *ptr
)
2743 struct mem_cgroup
*memcg
= NULL
;
2744 struct kmem_cache
*cachep
;
2747 page
= virt_to_head_page(ptr
);
2748 if (PageSlab(page
)) {
2749 cachep
= page
->slab_cache
;
2750 if (!is_root_cache(cachep
))
2751 memcg
= cachep
->memcg_params
.memcg
;
2753 /* page allocated by alloc_kmem_pages */
2754 memcg
= page
->mem_cgroup
;
2758 #endif /* CONFIG_MEMCG_KMEM */
2760 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
2763 * Because tail pages are not marked as "used", set it. We're under
2764 * zone->lru_lock, 'splitting on pmd' and compound_lock.
2765 * charge/uncharge will be never happen and move_account() is done under
2766 * compound_lock(), so we don't have to take care of races.
2768 void mem_cgroup_split_huge_fixup(struct page
*head
)
2772 if (mem_cgroup_disabled())
2775 for (i
= 1; i
< HPAGE_PMD_NR
; i
++)
2776 head
[i
].mem_cgroup
= head
->mem_cgroup
;
2778 __this_cpu_sub(head
->mem_cgroup
->stat
->count
[MEM_CGROUP_STAT_RSS_HUGE
],
2781 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
2783 #ifdef CONFIG_MEMCG_SWAP
2784 static void mem_cgroup_swap_statistics(struct mem_cgroup
*memcg
,
2787 int val
= (charge
) ? 1 : -1;
2788 this_cpu_add(memcg
->stat
->count
[MEM_CGROUP_STAT_SWAP
], val
);
2792 * mem_cgroup_move_swap_account - move swap charge and swap_cgroup's record.
2793 * @entry: swap entry to be moved
2794 * @from: mem_cgroup which the entry is moved from
2795 * @to: mem_cgroup which the entry is moved to
2797 * It succeeds only when the swap_cgroup's record for this entry is the same
2798 * as the mem_cgroup's id of @from.
2800 * Returns 0 on success, -EINVAL on failure.
2802 * The caller must have charged to @to, IOW, called page_counter_charge() about
2803 * both res and memsw, and called css_get().
2805 static int mem_cgroup_move_swap_account(swp_entry_t entry
,
2806 struct mem_cgroup
*from
, struct mem_cgroup
*to
)
2808 unsigned short old_id
, new_id
;
2810 old_id
= mem_cgroup_id(from
);
2811 new_id
= mem_cgroup_id(to
);
2813 if (swap_cgroup_cmpxchg(entry
, old_id
, new_id
) == old_id
) {
2814 mem_cgroup_swap_statistics(from
, false);
2815 mem_cgroup_swap_statistics(to
, true);
2821 static inline int mem_cgroup_move_swap_account(swp_entry_t entry
,
2822 struct mem_cgroup
*from
, struct mem_cgroup
*to
)
2828 static DEFINE_MUTEX(memcg_limit_mutex
);
2830 static int mem_cgroup_resize_limit(struct mem_cgroup
*memcg
,
2831 unsigned long limit
)
2833 unsigned long curusage
;
2834 unsigned long oldusage
;
2835 bool enlarge
= false;
2840 * For keeping hierarchical_reclaim simple, how long we should retry
2841 * is depends on callers. We set our retry-count to be function
2842 * of # of children which we should visit in this loop.
2844 retry_count
= MEM_CGROUP_RECLAIM_RETRIES
*
2845 mem_cgroup_count_children(memcg
);
2847 oldusage
= page_counter_read(&memcg
->memory
);
2850 if (signal_pending(current
)) {
2855 mutex_lock(&memcg_limit_mutex
);
2856 if (limit
> memcg
->memsw
.limit
) {
2857 mutex_unlock(&memcg_limit_mutex
);
2861 if (limit
> memcg
->memory
.limit
)
2863 ret
= page_counter_limit(&memcg
->memory
, limit
);
2864 mutex_unlock(&memcg_limit_mutex
);
2869 try_to_free_mem_cgroup_pages(memcg
, 1, GFP_KERNEL
, true);
2871 curusage
= page_counter_read(&memcg
->memory
);
2872 /* Usage is reduced ? */
2873 if (curusage
>= oldusage
)
2876 oldusage
= curusage
;
2877 } while (retry_count
);
2879 if (!ret
&& enlarge
)
2880 memcg_oom_recover(memcg
);
2885 static int mem_cgroup_resize_memsw_limit(struct mem_cgroup
*memcg
,
2886 unsigned long limit
)
2888 unsigned long curusage
;
2889 unsigned long oldusage
;
2890 bool enlarge
= false;
2894 /* see mem_cgroup_resize_res_limit */
2895 retry_count
= MEM_CGROUP_RECLAIM_RETRIES
*
2896 mem_cgroup_count_children(memcg
);
2898 oldusage
= page_counter_read(&memcg
->memsw
);
2901 if (signal_pending(current
)) {
2906 mutex_lock(&memcg_limit_mutex
);
2907 if (limit
< memcg
->memory
.limit
) {
2908 mutex_unlock(&memcg_limit_mutex
);
2912 if (limit
> memcg
->memsw
.limit
)
2914 ret
= page_counter_limit(&memcg
->memsw
, limit
);
2915 mutex_unlock(&memcg_limit_mutex
);
2920 try_to_free_mem_cgroup_pages(memcg
, 1, GFP_KERNEL
, false);
2922 curusage
= page_counter_read(&memcg
->memsw
);
2923 /* Usage is reduced ? */
2924 if (curusage
>= oldusage
)
2927 oldusage
= curusage
;
2928 } while (retry_count
);
2930 if (!ret
&& enlarge
)
2931 memcg_oom_recover(memcg
);
2936 unsigned long mem_cgroup_soft_limit_reclaim(struct zone
*zone
, int order
,
2938 unsigned long *total_scanned
)
2940 unsigned long nr_reclaimed
= 0;
2941 struct mem_cgroup_per_zone
*mz
, *next_mz
= NULL
;
2942 unsigned long reclaimed
;
2944 struct mem_cgroup_tree_per_zone
*mctz
;
2945 unsigned long excess
;
2946 unsigned long nr_scanned
;
2951 mctz
= soft_limit_tree_node_zone(zone_to_nid(zone
), zone_idx(zone
));
2953 * This loop can run a while, specially if mem_cgroup's continuously
2954 * keep exceeding their soft limit and putting the system under
2961 mz
= mem_cgroup_largest_soft_limit_node(mctz
);
2966 reclaimed
= mem_cgroup_soft_reclaim(mz
->memcg
, zone
,
2967 gfp_mask
, &nr_scanned
);
2968 nr_reclaimed
+= reclaimed
;
2969 *total_scanned
+= nr_scanned
;
2970 spin_lock_irq(&mctz
->lock
);
2971 __mem_cgroup_remove_exceeded(mz
, mctz
);
2974 * If we failed to reclaim anything from this memory cgroup
2975 * it is time to move on to the next cgroup
2979 next_mz
= __mem_cgroup_largest_soft_limit_node(mctz
);
2981 excess
= soft_limit_excess(mz
->memcg
);
2983 * One school of thought says that we should not add
2984 * back the node to the tree if reclaim returns 0.
2985 * But our reclaim could return 0, simply because due
2986 * to priority we are exposing a smaller subset of
2987 * memory to reclaim from. Consider this as a longer
2990 /* If excess == 0, no tree ops */
2991 __mem_cgroup_insert_exceeded(mz
, mctz
, excess
);
2992 spin_unlock_irq(&mctz
->lock
);
2993 css_put(&mz
->memcg
->css
);
2996 * Could not reclaim anything and there are no more
2997 * mem cgroups to try or we seem to be looping without
2998 * reclaiming anything.
3000 if (!nr_reclaimed
&&
3002 loop
> MEM_CGROUP_MAX_SOFT_LIMIT_RECLAIM_LOOPS
))
3004 } while (!nr_reclaimed
);
3006 css_put(&next_mz
->memcg
->css
);
3007 return nr_reclaimed
;
3011 * Test whether @memcg has children, dead or alive. Note that this
3012 * function doesn't care whether @memcg has use_hierarchy enabled and
3013 * returns %true if there are child csses according to the cgroup
3014 * hierarchy. Testing use_hierarchy is the caller's responsiblity.
3016 static inline bool memcg_has_children(struct mem_cgroup
*memcg
)
3021 * The lock does not prevent addition or deletion of children, but
3022 * it prevents a new child from being initialized based on this
3023 * parent in css_online(), so it's enough to decide whether
3024 * hierarchically inherited attributes can still be changed or not.
3026 lockdep_assert_held(&memcg_create_mutex
);
3029 ret
= css_next_child(NULL
, &memcg
->css
);
3035 * Reclaims as many pages from the given memcg as possible and moves
3036 * the rest to the parent.
3038 * Caller is responsible for holding css reference for memcg.
3040 static int mem_cgroup_force_empty(struct mem_cgroup
*memcg
)
3042 int nr_retries
= MEM_CGROUP_RECLAIM_RETRIES
;
3044 /* we call try-to-free pages for make this cgroup empty */
3045 lru_add_drain_all();
3046 /* try to free all pages in this cgroup */
3047 while (nr_retries
&& page_counter_read(&memcg
->memory
)) {
3050 if (signal_pending(current
))
3053 progress
= try_to_free_mem_cgroup_pages(memcg
, 1,
3057 /* maybe some writeback is necessary */
3058 congestion_wait(BLK_RW_ASYNC
, HZ
/10);
3066 static ssize_t
mem_cgroup_force_empty_write(struct kernfs_open_file
*of
,
3067 char *buf
, size_t nbytes
,
3070 struct mem_cgroup
*memcg
= mem_cgroup_from_css(of_css(of
));
3072 if (mem_cgroup_is_root(memcg
))
3074 return mem_cgroup_force_empty(memcg
) ?: nbytes
;
3077 static u64
mem_cgroup_hierarchy_read(struct cgroup_subsys_state
*css
,
3080 return mem_cgroup_from_css(css
)->use_hierarchy
;
3083 static int mem_cgroup_hierarchy_write(struct cgroup_subsys_state
*css
,
3084 struct cftype
*cft
, u64 val
)
3087 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
3088 struct mem_cgroup
*parent_memcg
= mem_cgroup_from_css(memcg
->css
.parent
);
3090 mutex_lock(&memcg_create_mutex
);
3092 if (memcg
->use_hierarchy
== val
)
3096 * If parent's use_hierarchy is set, we can't make any modifications
3097 * in the child subtrees. If it is unset, then the change can
3098 * occur, provided the current cgroup has no children.
3100 * For the root cgroup, parent_mem is NULL, we allow value to be
3101 * set if there are no children.
3103 if ((!parent_memcg
|| !parent_memcg
->use_hierarchy
) &&
3104 (val
== 1 || val
== 0)) {
3105 if (!memcg_has_children(memcg
))
3106 memcg
->use_hierarchy
= val
;
3113 mutex_unlock(&memcg_create_mutex
);
3118 static unsigned long tree_stat(struct mem_cgroup
*memcg
,
3119 enum mem_cgroup_stat_index idx
)
3121 struct mem_cgroup
*iter
;
3124 /* Per-cpu values can be negative, use a signed accumulator */
3125 for_each_mem_cgroup_tree(iter
, memcg
)
3126 val
+= mem_cgroup_read_stat(iter
, idx
);
3128 if (val
< 0) /* race ? */
3133 static inline u64
mem_cgroup_usage(struct mem_cgroup
*memcg
, bool swap
)
3137 if (mem_cgroup_is_root(memcg
)) {
3138 val
= tree_stat(memcg
, MEM_CGROUP_STAT_CACHE
);
3139 val
+= tree_stat(memcg
, MEM_CGROUP_STAT_RSS
);
3141 val
+= tree_stat(memcg
, MEM_CGROUP_STAT_SWAP
);
3144 val
= page_counter_read(&memcg
->memory
);
3146 val
= page_counter_read(&memcg
->memsw
);
3148 return val
<< PAGE_SHIFT
;
3159 static u64
mem_cgroup_read_u64(struct cgroup_subsys_state
*css
,
3162 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
3163 struct page_counter
*counter
;
3165 switch (MEMFILE_TYPE(cft
->private)) {
3167 counter
= &memcg
->memory
;
3170 counter
= &memcg
->memsw
;
3173 counter
= &memcg
->kmem
;
3179 switch (MEMFILE_ATTR(cft
->private)) {
3181 if (counter
== &memcg
->memory
)
3182 return mem_cgroup_usage(memcg
, false);
3183 if (counter
== &memcg
->memsw
)
3184 return mem_cgroup_usage(memcg
, true);
3185 return (u64
)page_counter_read(counter
) * PAGE_SIZE
;
3187 return (u64
)counter
->limit
* PAGE_SIZE
;
3189 return (u64
)counter
->watermark
* PAGE_SIZE
;
3191 return counter
->failcnt
;
3192 case RES_SOFT_LIMIT
:
3193 return (u64
)memcg
->soft_limit
* PAGE_SIZE
;
3199 #ifdef CONFIG_MEMCG_KMEM
3200 static int memcg_activate_kmem(struct mem_cgroup
*memcg
,
3201 unsigned long nr_pages
)
3206 BUG_ON(memcg
->kmemcg_id
>= 0);
3207 BUG_ON(memcg
->kmem_acct_activated
);
3208 BUG_ON(memcg
->kmem_acct_active
);
3211 * For simplicity, we won't allow this to be disabled. It also can't
3212 * be changed if the cgroup has children already, or if tasks had
3215 * If tasks join before we set the limit, a person looking at
3216 * kmem.usage_in_bytes will have no way to determine when it took
3217 * place, which makes the value quite meaningless.
3219 * After it first became limited, changes in the value of the limit are
3220 * of course permitted.
3222 mutex_lock(&memcg_create_mutex
);
3223 if (cgroup_has_tasks(memcg
->css
.cgroup
) ||
3224 (memcg
->use_hierarchy
&& memcg_has_children(memcg
)))
3226 mutex_unlock(&memcg_create_mutex
);
3230 memcg_id
= memcg_alloc_cache_id();
3237 * We couldn't have accounted to this cgroup, because it hasn't got
3238 * activated yet, so this should succeed.
3240 err
= page_counter_limit(&memcg
->kmem
, nr_pages
);
3243 static_key_slow_inc(&memcg_kmem_enabled_key
);
3245 * A memory cgroup is considered kmem-active as soon as it gets
3246 * kmemcg_id. Setting the id after enabling static branching will
3247 * guarantee no one starts accounting before all call sites are
3250 memcg
->kmemcg_id
= memcg_id
;
3251 memcg
->kmem_acct_activated
= true;
3252 memcg
->kmem_acct_active
= true;
3257 static int memcg_update_kmem_limit(struct mem_cgroup
*memcg
,
3258 unsigned long limit
)
3262 mutex_lock(&memcg_limit_mutex
);
3263 if (!memcg_kmem_is_active(memcg
))
3264 ret
= memcg_activate_kmem(memcg
, limit
);
3266 ret
= page_counter_limit(&memcg
->kmem
, limit
);
3267 mutex_unlock(&memcg_limit_mutex
);
3271 static int memcg_propagate_kmem(struct mem_cgroup
*memcg
)
3274 struct mem_cgroup
*parent
= parent_mem_cgroup(memcg
);
3279 mutex_lock(&memcg_limit_mutex
);
3281 * If the parent cgroup is not kmem-active now, it cannot be activated
3282 * after this point, because it has at least one child already.
3284 if (memcg_kmem_is_active(parent
))
3285 ret
= memcg_activate_kmem(memcg
, PAGE_COUNTER_MAX
);
3286 mutex_unlock(&memcg_limit_mutex
);
3290 static int memcg_update_kmem_limit(struct mem_cgroup
*memcg
,
3291 unsigned long limit
)
3295 #endif /* CONFIG_MEMCG_KMEM */
3298 * The user of this function is...
3301 static ssize_t
mem_cgroup_write(struct kernfs_open_file
*of
,
3302 char *buf
, size_t nbytes
, loff_t off
)
3304 struct mem_cgroup
*memcg
= mem_cgroup_from_css(of_css(of
));
3305 unsigned long nr_pages
;
3308 buf
= strstrip(buf
);
3309 ret
= page_counter_memparse(buf
, "-1", &nr_pages
);
3313 switch (MEMFILE_ATTR(of_cft(of
)->private)) {
3315 if (mem_cgroup_is_root(memcg
)) { /* Can't set limit on root */
3319 switch (MEMFILE_TYPE(of_cft(of
)->private)) {
3321 ret
= mem_cgroup_resize_limit(memcg
, nr_pages
);
3324 ret
= mem_cgroup_resize_memsw_limit(memcg
, nr_pages
);
3327 ret
= memcg_update_kmem_limit(memcg
, nr_pages
);
3331 case RES_SOFT_LIMIT
:
3332 memcg
->soft_limit
= nr_pages
;
3336 return ret
?: nbytes
;
3339 static ssize_t
mem_cgroup_reset(struct kernfs_open_file
*of
, char *buf
,
3340 size_t nbytes
, loff_t off
)
3342 struct mem_cgroup
*memcg
= mem_cgroup_from_css(of_css(of
));
3343 struct page_counter
*counter
;
3345 switch (MEMFILE_TYPE(of_cft(of
)->private)) {
3347 counter
= &memcg
->memory
;
3350 counter
= &memcg
->memsw
;
3353 counter
= &memcg
->kmem
;
3359 switch (MEMFILE_ATTR(of_cft(of
)->private)) {
3361 page_counter_reset_watermark(counter
);
3364 counter
->failcnt
= 0;
3373 static u64
mem_cgroup_move_charge_read(struct cgroup_subsys_state
*css
,
3376 return mem_cgroup_from_css(css
)->move_charge_at_immigrate
;
3380 static int mem_cgroup_move_charge_write(struct cgroup_subsys_state
*css
,
3381 struct cftype
*cft
, u64 val
)
3383 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
3385 if (val
& ~MOVE_MASK
)
3389 * No kind of locking is needed in here, because ->can_attach() will
3390 * check this value once in the beginning of the process, and then carry
3391 * on with stale data. This means that changes to this value will only
3392 * affect task migrations starting after the change.
3394 memcg
->move_charge_at_immigrate
= val
;
3398 static int mem_cgroup_move_charge_write(struct cgroup_subsys_state
*css
,
3399 struct cftype
*cft
, u64 val
)
3406 static int memcg_numa_stat_show(struct seq_file
*m
, void *v
)
3410 unsigned int lru_mask
;
3413 static const struct numa_stat stats
[] = {
3414 { "total", LRU_ALL
},
3415 { "file", LRU_ALL_FILE
},
3416 { "anon", LRU_ALL_ANON
},
3417 { "unevictable", BIT(LRU_UNEVICTABLE
) },
3419 const struct numa_stat
*stat
;
3422 struct mem_cgroup
*memcg
= mem_cgroup_from_css(seq_css(m
));
3424 for (stat
= stats
; stat
< stats
+ ARRAY_SIZE(stats
); stat
++) {
3425 nr
= mem_cgroup_nr_lru_pages(memcg
, stat
->lru_mask
);
3426 seq_printf(m
, "%s=%lu", stat
->name
, nr
);
3427 for_each_node_state(nid
, N_MEMORY
) {
3428 nr
= mem_cgroup_node_nr_lru_pages(memcg
, nid
,
3430 seq_printf(m
, " N%d=%lu", nid
, nr
);
3435 for (stat
= stats
; stat
< stats
+ ARRAY_SIZE(stats
); stat
++) {
3436 struct mem_cgroup
*iter
;
3439 for_each_mem_cgroup_tree(iter
, memcg
)
3440 nr
+= mem_cgroup_nr_lru_pages(iter
, stat
->lru_mask
);
3441 seq_printf(m
, "hierarchical_%s=%lu", stat
->name
, nr
);
3442 for_each_node_state(nid
, N_MEMORY
) {
3444 for_each_mem_cgroup_tree(iter
, memcg
)
3445 nr
+= mem_cgroup_node_nr_lru_pages(
3446 iter
, nid
, stat
->lru_mask
);
3447 seq_printf(m
, " N%d=%lu", nid
, nr
);
3454 #endif /* CONFIG_NUMA */
3456 static int memcg_stat_show(struct seq_file
*m
, void *v
)
3458 struct mem_cgroup
*memcg
= mem_cgroup_from_css(seq_css(m
));
3459 unsigned long memory
, memsw
;
3460 struct mem_cgroup
*mi
;
3463 BUILD_BUG_ON(ARRAY_SIZE(mem_cgroup_stat_names
) !=
3464 MEM_CGROUP_STAT_NSTATS
);
3465 BUILD_BUG_ON(ARRAY_SIZE(mem_cgroup_events_names
) !=
3466 MEM_CGROUP_EVENTS_NSTATS
);
3467 BUILD_BUG_ON(ARRAY_SIZE(mem_cgroup_lru_names
) != NR_LRU_LISTS
);
3469 for (i
= 0; i
< MEM_CGROUP_STAT_NSTATS
; i
++) {
3470 if (i
== MEM_CGROUP_STAT_SWAP
&& !do_swap_account
)
3472 seq_printf(m
, "%s %ld\n", mem_cgroup_stat_names
[i
],
3473 mem_cgroup_read_stat(memcg
, i
) * PAGE_SIZE
);
3476 for (i
= 0; i
< MEM_CGROUP_EVENTS_NSTATS
; i
++)
3477 seq_printf(m
, "%s %lu\n", mem_cgroup_events_names
[i
],
3478 mem_cgroup_read_events(memcg
, i
));
3480 for (i
= 0; i
< NR_LRU_LISTS
; i
++)
3481 seq_printf(m
, "%s %lu\n", mem_cgroup_lru_names
[i
],
3482 mem_cgroup_nr_lru_pages(memcg
, BIT(i
)) * PAGE_SIZE
);
3484 /* Hierarchical information */
3485 memory
= memsw
= PAGE_COUNTER_MAX
;
3486 for (mi
= memcg
; mi
; mi
= parent_mem_cgroup(mi
)) {
3487 memory
= min(memory
, mi
->memory
.limit
);
3488 memsw
= min(memsw
, mi
->memsw
.limit
);
3490 seq_printf(m
, "hierarchical_memory_limit %llu\n",
3491 (u64
)memory
* PAGE_SIZE
);
3492 if (do_swap_account
)
3493 seq_printf(m
, "hierarchical_memsw_limit %llu\n",
3494 (u64
)memsw
* PAGE_SIZE
);
3496 for (i
= 0; i
< MEM_CGROUP_STAT_NSTATS
; i
++) {
3499 if (i
== MEM_CGROUP_STAT_SWAP
&& !do_swap_account
)
3501 for_each_mem_cgroup_tree(mi
, memcg
)
3502 val
+= mem_cgroup_read_stat(mi
, i
) * PAGE_SIZE
;
3503 seq_printf(m
, "total_%s %lld\n", mem_cgroup_stat_names
[i
], val
);
3506 for (i
= 0; i
< MEM_CGROUP_EVENTS_NSTATS
; i
++) {
3507 unsigned long long val
= 0;
3509 for_each_mem_cgroup_tree(mi
, memcg
)
3510 val
+= mem_cgroup_read_events(mi
, i
);
3511 seq_printf(m
, "total_%s %llu\n",
3512 mem_cgroup_events_names
[i
], val
);
3515 for (i
= 0; i
< NR_LRU_LISTS
; i
++) {
3516 unsigned long long val
= 0;
3518 for_each_mem_cgroup_tree(mi
, memcg
)
3519 val
+= mem_cgroup_nr_lru_pages(mi
, BIT(i
)) * PAGE_SIZE
;
3520 seq_printf(m
, "total_%s %llu\n", mem_cgroup_lru_names
[i
], val
);
3523 #ifdef CONFIG_DEBUG_VM
3526 struct mem_cgroup_per_zone
*mz
;
3527 struct zone_reclaim_stat
*rstat
;
3528 unsigned long recent_rotated
[2] = {0, 0};
3529 unsigned long recent_scanned
[2] = {0, 0};
3531 for_each_online_node(nid
)
3532 for (zid
= 0; zid
< MAX_NR_ZONES
; zid
++) {
3533 mz
= &memcg
->nodeinfo
[nid
]->zoneinfo
[zid
];
3534 rstat
= &mz
->lruvec
.reclaim_stat
;
3536 recent_rotated
[0] += rstat
->recent_rotated
[0];
3537 recent_rotated
[1] += rstat
->recent_rotated
[1];
3538 recent_scanned
[0] += rstat
->recent_scanned
[0];
3539 recent_scanned
[1] += rstat
->recent_scanned
[1];
3541 seq_printf(m
, "recent_rotated_anon %lu\n", recent_rotated
[0]);
3542 seq_printf(m
, "recent_rotated_file %lu\n", recent_rotated
[1]);
3543 seq_printf(m
, "recent_scanned_anon %lu\n", recent_scanned
[0]);
3544 seq_printf(m
, "recent_scanned_file %lu\n", recent_scanned
[1]);
3551 static u64
mem_cgroup_swappiness_read(struct cgroup_subsys_state
*css
,
3554 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
3556 return mem_cgroup_swappiness(memcg
);
3559 static int mem_cgroup_swappiness_write(struct cgroup_subsys_state
*css
,
3560 struct cftype
*cft
, u64 val
)
3562 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
3568 memcg
->swappiness
= val
;
3570 vm_swappiness
= val
;
3575 static void __mem_cgroup_threshold(struct mem_cgroup
*memcg
, bool swap
)
3577 struct mem_cgroup_threshold_ary
*t
;
3578 unsigned long usage
;
3583 t
= rcu_dereference(memcg
->thresholds
.primary
);
3585 t
= rcu_dereference(memcg
->memsw_thresholds
.primary
);
3590 usage
= mem_cgroup_usage(memcg
, swap
);
3593 * current_threshold points to threshold just below or equal to usage.
3594 * If it's not true, a threshold was crossed after last
3595 * call of __mem_cgroup_threshold().
3597 i
= t
->current_threshold
;
3600 * Iterate backward over array of thresholds starting from
3601 * current_threshold and check if a threshold is crossed.
3602 * If none of thresholds below usage is crossed, we read
3603 * only one element of the array here.
3605 for (; i
>= 0 && unlikely(t
->entries
[i
].threshold
> usage
); i
--)
3606 eventfd_signal(t
->entries
[i
].eventfd
, 1);
3608 /* i = current_threshold + 1 */
3612 * Iterate forward over array of thresholds starting from
3613 * current_threshold+1 and check if a threshold is crossed.
3614 * If none of thresholds above usage is crossed, we read
3615 * only one element of the array here.
3617 for (; i
< t
->size
&& unlikely(t
->entries
[i
].threshold
<= usage
); i
++)
3618 eventfd_signal(t
->entries
[i
].eventfd
, 1);
3620 /* Update current_threshold */
3621 t
->current_threshold
= i
- 1;
3626 static void mem_cgroup_threshold(struct mem_cgroup
*memcg
)
3629 __mem_cgroup_threshold(memcg
, false);
3630 if (do_swap_account
)
3631 __mem_cgroup_threshold(memcg
, true);
3633 memcg
= parent_mem_cgroup(memcg
);
3637 static int compare_thresholds(const void *a
, const void *b
)
3639 const struct mem_cgroup_threshold
*_a
= a
;
3640 const struct mem_cgroup_threshold
*_b
= b
;
3642 if (_a
->threshold
> _b
->threshold
)
3645 if (_a
->threshold
< _b
->threshold
)
3651 static int mem_cgroup_oom_notify_cb(struct mem_cgroup
*memcg
)
3653 struct mem_cgroup_eventfd_list
*ev
;
3655 spin_lock(&memcg_oom_lock
);
3657 list_for_each_entry(ev
, &memcg
->oom_notify
, list
)
3658 eventfd_signal(ev
->eventfd
, 1);
3660 spin_unlock(&memcg_oom_lock
);
3664 static void mem_cgroup_oom_notify(struct mem_cgroup
*memcg
)
3666 struct mem_cgroup
*iter
;
3668 for_each_mem_cgroup_tree(iter
, memcg
)
3669 mem_cgroup_oom_notify_cb(iter
);
3672 static int __mem_cgroup_usage_register_event(struct mem_cgroup
*memcg
,
3673 struct eventfd_ctx
*eventfd
, const char *args
, enum res_type type
)
3675 struct mem_cgroup_thresholds
*thresholds
;
3676 struct mem_cgroup_threshold_ary
*new;
3677 unsigned long threshold
;
3678 unsigned long usage
;
3681 ret
= page_counter_memparse(args
, "-1", &threshold
);
3685 mutex_lock(&memcg
->thresholds_lock
);
3688 thresholds
= &memcg
->thresholds
;
3689 usage
= mem_cgroup_usage(memcg
, false);
3690 } else if (type
== _MEMSWAP
) {
3691 thresholds
= &memcg
->memsw_thresholds
;
3692 usage
= mem_cgroup_usage(memcg
, true);
3696 /* Check if a threshold crossed before adding a new one */
3697 if (thresholds
->primary
)
3698 __mem_cgroup_threshold(memcg
, type
== _MEMSWAP
);
3700 size
= thresholds
->primary
? thresholds
->primary
->size
+ 1 : 1;
3702 /* Allocate memory for new array of thresholds */
3703 new = kmalloc(sizeof(*new) + size
* sizeof(struct mem_cgroup_threshold
),
3711 /* Copy thresholds (if any) to new array */
3712 if (thresholds
->primary
) {
3713 memcpy(new->entries
, thresholds
->primary
->entries
, (size
- 1) *
3714 sizeof(struct mem_cgroup_threshold
));
3717 /* Add new threshold */
3718 new->entries
[size
- 1].eventfd
= eventfd
;
3719 new->entries
[size
- 1].threshold
= threshold
;
3721 /* Sort thresholds. Registering of new threshold isn't time-critical */
3722 sort(new->entries
, size
, sizeof(struct mem_cgroup_threshold
),
3723 compare_thresholds
, NULL
);
3725 /* Find current threshold */
3726 new->current_threshold
= -1;
3727 for (i
= 0; i
< size
; i
++) {
3728 if (new->entries
[i
].threshold
<= usage
) {
3730 * new->current_threshold will not be used until
3731 * rcu_assign_pointer(), so it's safe to increment
3734 ++new->current_threshold
;
3739 /* Free old spare buffer and save old primary buffer as spare */
3740 kfree(thresholds
->spare
);
3741 thresholds
->spare
= thresholds
->primary
;
3743 rcu_assign_pointer(thresholds
->primary
, new);
3745 /* To be sure that nobody uses thresholds */
3749 mutex_unlock(&memcg
->thresholds_lock
);
3754 static int mem_cgroup_usage_register_event(struct mem_cgroup
*memcg
,
3755 struct eventfd_ctx
*eventfd
, const char *args
)
3757 return __mem_cgroup_usage_register_event(memcg
, eventfd
, args
, _MEM
);
3760 static int memsw_cgroup_usage_register_event(struct mem_cgroup
*memcg
,
3761 struct eventfd_ctx
*eventfd
, const char *args
)
3763 return __mem_cgroup_usage_register_event(memcg
, eventfd
, args
, _MEMSWAP
);
3766 static void __mem_cgroup_usage_unregister_event(struct mem_cgroup
*memcg
,
3767 struct eventfd_ctx
*eventfd
, enum res_type type
)
3769 struct mem_cgroup_thresholds
*thresholds
;
3770 struct mem_cgroup_threshold_ary
*new;
3771 unsigned long usage
;
3774 mutex_lock(&memcg
->thresholds_lock
);
3777 thresholds
= &memcg
->thresholds
;
3778 usage
= mem_cgroup_usage(memcg
, false);
3779 } else if (type
== _MEMSWAP
) {
3780 thresholds
= &memcg
->memsw_thresholds
;
3781 usage
= mem_cgroup_usage(memcg
, true);
3785 if (!thresholds
->primary
)
3788 /* Check if a threshold crossed before removing */
3789 __mem_cgroup_threshold(memcg
, type
== _MEMSWAP
);
3791 /* Calculate new number of threshold */
3793 for (i
= 0; i
< thresholds
->primary
->size
; i
++) {
3794 if (thresholds
->primary
->entries
[i
].eventfd
!= eventfd
)
3798 new = thresholds
->spare
;
3800 /* Set thresholds array to NULL if we don't have thresholds */
3809 /* Copy thresholds and find current threshold */
3810 new->current_threshold
= -1;
3811 for (i
= 0, j
= 0; i
< thresholds
->primary
->size
; i
++) {
3812 if (thresholds
->primary
->entries
[i
].eventfd
== eventfd
)
3815 new->entries
[j
] = thresholds
->primary
->entries
[i
];
3816 if (new->entries
[j
].threshold
<= usage
) {
3818 * new->current_threshold will not be used
3819 * until rcu_assign_pointer(), so it's safe to increment
3822 ++new->current_threshold
;
3828 /* Swap primary and spare array */
3829 thresholds
->spare
= thresholds
->primary
;
3830 /* If all events are unregistered, free the spare array */
3832 kfree(thresholds
->spare
);
3833 thresholds
->spare
= NULL
;
3836 rcu_assign_pointer(thresholds
->primary
, new);
3838 /* To be sure that nobody uses thresholds */
3841 mutex_unlock(&memcg
->thresholds_lock
);
3844 static void mem_cgroup_usage_unregister_event(struct mem_cgroup
*memcg
,
3845 struct eventfd_ctx
*eventfd
)
3847 return __mem_cgroup_usage_unregister_event(memcg
, eventfd
, _MEM
);
3850 static void memsw_cgroup_usage_unregister_event(struct mem_cgroup
*memcg
,
3851 struct eventfd_ctx
*eventfd
)
3853 return __mem_cgroup_usage_unregister_event(memcg
, eventfd
, _MEMSWAP
);
3856 static int mem_cgroup_oom_register_event(struct mem_cgroup
*memcg
,
3857 struct eventfd_ctx
*eventfd
, const char *args
)
3859 struct mem_cgroup_eventfd_list
*event
;
3861 event
= kmalloc(sizeof(*event
), GFP_KERNEL
);
3865 spin_lock(&memcg_oom_lock
);
3867 event
->eventfd
= eventfd
;
3868 list_add(&event
->list
, &memcg
->oom_notify
);
3870 /* already in OOM ? */
3871 if (atomic_read(&memcg
->under_oom
))
3872 eventfd_signal(eventfd
, 1);
3873 spin_unlock(&memcg_oom_lock
);
3878 static void mem_cgroup_oom_unregister_event(struct mem_cgroup
*memcg
,
3879 struct eventfd_ctx
*eventfd
)
3881 struct mem_cgroup_eventfd_list
*ev
, *tmp
;
3883 spin_lock(&memcg_oom_lock
);
3885 list_for_each_entry_safe(ev
, tmp
, &memcg
->oom_notify
, list
) {
3886 if (ev
->eventfd
== eventfd
) {
3887 list_del(&ev
->list
);
3892 spin_unlock(&memcg_oom_lock
);
3895 static int mem_cgroup_oom_control_read(struct seq_file
*sf
, void *v
)
3897 struct mem_cgroup
*memcg
= mem_cgroup_from_css(seq_css(sf
));
3899 seq_printf(sf
, "oom_kill_disable %d\n", memcg
->oom_kill_disable
);
3900 seq_printf(sf
, "under_oom %d\n", (bool)atomic_read(&memcg
->under_oom
));
3904 static int mem_cgroup_oom_control_write(struct cgroup_subsys_state
*css
,
3905 struct cftype
*cft
, u64 val
)
3907 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
3909 /* cannot set to root cgroup and only 0 and 1 are allowed */
3910 if (!css
->parent
|| !((val
== 0) || (val
== 1)))
3913 memcg
->oom_kill_disable
= val
;
3915 memcg_oom_recover(memcg
);
3920 #ifdef CONFIG_MEMCG_KMEM
3921 static int memcg_init_kmem(struct mem_cgroup
*memcg
, struct cgroup_subsys
*ss
)
3925 ret
= memcg_propagate_kmem(memcg
);
3929 return mem_cgroup_sockets_init(memcg
, ss
);
3932 static void memcg_deactivate_kmem(struct mem_cgroup
*memcg
)
3934 struct cgroup_subsys_state
*css
;
3935 struct mem_cgroup
*parent
, *child
;
3938 if (!memcg
->kmem_acct_active
)
3942 * Clear the 'active' flag before clearing memcg_caches arrays entries.
3943 * Since we take the slab_mutex in memcg_deactivate_kmem_caches(), it
3944 * guarantees no cache will be created for this cgroup after we are
3945 * done (see memcg_create_kmem_cache()).
3947 memcg
->kmem_acct_active
= false;
3949 memcg_deactivate_kmem_caches(memcg
);
3951 kmemcg_id
= memcg
->kmemcg_id
;
3952 BUG_ON(kmemcg_id
< 0);
3954 parent
= parent_mem_cgroup(memcg
);
3956 parent
= root_mem_cgroup
;
3959 * Change kmemcg_id of this cgroup and all its descendants to the
3960 * parent's id, and then move all entries from this cgroup's list_lrus
3961 * to ones of the parent. After we have finished, all list_lrus
3962 * corresponding to this cgroup are guaranteed to remain empty. The
3963 * ordering is imposed by list_lru_node->lock taken by
3964 * memcg_drain_all_list_lrus().
3966 css_for_each_descendant_pre(css
, &memcg
->css
) {
3967 child
= mem_cgroup_from_css(css
);
3968 BUG_ON(child
->kmemcg_id
!= kmemcg_id
);
3969 child
->kmemcg_id
= parent
->kmemcg_id
;
3970 if (!memcg
->use_hierarchy
)
3973 memcg_drain_all_list_lrus(kmemcg_id
, parent
->kmemcg_id
);
3975 memcg_free_cache_id(kmemcg_id
);
3978 static void memcg_destroy_kmem(struct mem_cgroup
*memcg
)
3980 if (memcg
->kmem_acct_activated
) {
3981 memcg_destroy_kmem_caches(memcg
);
3982 static_key_slow_dec(&memcg_kmem_enabled_key
);
3983 WARN_ON(page_counter_read(&memcg
->kmem
));
3985 mem_cgroup_sockets_destroy(memcg
);
3988 static int memcg_init_kmem(struct mem_cgroup
*memcg
, struct cgroup_subsys
*ss
)
3993 static void memcg_deactivate_kmem(struct mem_cgroup
*memcg
)
3997 static void memcg_destroy_kmem(struct mem_cgroup
*memcg
)
4003 * DO NOT USE IN NEW FILES.
4005 * "cgroup.event_control" implementation.
4007 * This is way over-engineered. It tries to support fully configurable
4008 * events for each user. Such level of flexibility is completely
4009 * unnecessary especially in the light of the planned unified hierarchy.
4011 * Please deprecate this and replace with something simpler if at all
4016 * Unregister event and free resources.
4018 * Gets called from workqueue.
4020 static void memcg_event_remove(struct work_struct
*work
)
4022 struct mem_cgroup_event
*event
=
4023 container_of(work
, struct mem_cgroup_event
, remove
);
4024 struct mem_cgroup
*memcg
= event
->memcg
;
4026 remove_wait_queue(event
->wqh
, &event
->wait
);
4028 event
->unregister_event(memcg
, event
->eventfd
);
4030 /* Notify userspace the event is going away. */
4031 eventfd_signal(event
->eventfd
, 1);
4033 eventfd_ctx_put(event
->eventfd
);
4035 css_put(&memcg
->css
);
4039 * Gets called on POLLHUP on eventfd when user closes it.
4041 * Called with wqh->lock held and interrupts disabled.
4043 static int memcg_event_wake(wait_queue_t
*wait
, unsigned mode
,
4044 int sync
, void *key
)
4046 struct mem_cgroup_event
*event
=
4047 container_of(wait
, struct mem_cgroup_event
, wait
);
4048 struct mem_cgroup
*memcg
= event
->memcg
;
4049 unsigned long flags
= (unsigned long)key
;
4051 if (flags
& POLLHUP
) {
4053 * If the event has been detached at cgroup removal, we
4054 * can simply return knowing the other side will cleanup
4057 * We can't race against event freeing since the other
4058 * side will require wqh->lock via remove_wait_queue(),
4061 spin_lock(&memcg
->event_list_lock
);
4062 if (!list_empty(&event
->list
)) {
4063 list_del_init(&event
->list
);
4065 * We are in atomic context, but cgroup_event_remove()
4066 * may sleep, so we have to call it in workqueue.
4068 schedule_work(&event
->remove
);
4070 spin_unlock(&memcg
->event_list_lock
);
4076 static void memcg_event_ptable_queue_proc(struct file
*file
,
4077 wait_queue_head_t
*wqh
, poll_table
*pt
)
4079 struct mem_cgroup_event
*event
=
4080 container_of(pt
, struct mem_cgroup_event
, pt
);
4083 add_wait_queue(wqh
, &event
->wait
);
4087 * DO NOT USE IN NEW FILES.
4089 * Parse input and register new cgroup event handler.
4091 * Input must be in format '<event_fd> <control_fd> <args>'.
4092 * Interpretation of args is defined by control file implementation.
4094 static ssize_t
memcg_write_event_control(struct kernfs_open_file
*of
,
4095 char *buf
, size_t nbytes
, loff_t off
)
4097 struct cgroup_subsys_state
*css
= of_css(of
);
4098 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
4099 struct mem_cgroup_event
*event
;
4100 struct cgroup_subsys_state
*cfile_css
;
4101 unsigned int efd
, cfd
;
4108 buf
= strstrip(buf
);
4110 efd
= simple_strtoul(buf
, &endp
, 10);
4115 cfd
= simple_strtoul(buf
, &endp
, 10);
4116 if ((*endp
!= ' ') && (*endp
!= '\0'))
4120 event
= kzalloc(sizeof(*event
), GFP_KERNEL
);
4124 event
->memcg
= memcg
;
4125 INIT_LIST_HEAD(&event
->list
);
4126 init_poll_funcptr(&event
->pt
, memcg_event_ptable_queue_proc
);
4127 init_waitqueue_func_entry(&event
->wait
, memcg_event_wake
);
4128 INIT_WORK(&event
->remove
, memcg_event_remove
);
4136 event
->eventfd
= eventfd_ctx_fileget(efile
.file
);
4137 if (IS_ERR(event
->eventfd
)) {
4138 ret
= PTR_ERR(event
->eventfd
);
4145 goto out_put_eventfd
;
4148 /* the process need read permission on control file */
4149 /* AV: shouldn't we check that it's been opened for read instead? */
4150 ret
= inode_permission(file_inode(cfile
.file
), MAY_READ
);
4155 * Determine the event callbacks and set them in @event. This used
4156 * to be done via struct cftype but cgroup core no longer knows
4157 * about these events. The following is crude but the whole thing
4158 * is for compatibility anyway.
4160 * DO NOT ADD NEW FILES.
4162 name
= cfile
.file
->f_path
.dentry
->d_name
.name
;
4164 if (!strcmp(name
, "memory.usage_in_bytes")) {
4165 event
->register_event
= mem_cgroup_usage_register_event
;
4166 event
->unregister_event
= mem_cgroup_usage_unregister_event
;
4167 } else if (!strcmp(name
, "memory.oom_control")) {
4168 event
->register_event
= mem_cgroup_oom_register_event
;
4169 event
->unregister_event
= mem_cgroup_oom_unregister_event
;
4170 } else if (!strcmp(name
, "memory.pressure_level")) {
4171 event
->register_event
= vmpressure_register_event
;
4172 event
->unregister_event
= vmpressure_unregister_event
;
4173 } else if (!strcmp(name
, "memory.memsw.usage_in_bytes")) {
4174 event
->register_event
= memsw_cgroup_usage_register_event
;
4175 event
->unregister_event
= memsw_cgroup_usage_unregister_event
;
4182 * Verify @cfile should belong to @css. Also, remaining events are
4183 * automatically removed on cgroup destruction but the removal is
4184 * asynchronous, so take an extra ref on @css.
4186 cfile_css
= css_tryget_online_from_dir(cfile
.file
->f_path
.dentry
->d_parent
,
4187 &memory_cgrp_subsys
);
4189 if (IS_ERR(cfile_css
))
4191 if (cfile_css
!= css
) {
4196 ret
= event
->register_event(memcg
, event
->eventfd
, buf
);
4200 efile
.file
->f_op
->poll(efile
.file
, &event
->pt
);
4202 spin_lock(&memcg
->event_list_lock
);
4203 list_add(&event
->list
, &memcg
->event_list
);
4204 spin_unlock(&memcg
->event_list_lock
);
4216 eventfd_ctx_put(event
->eventfd
);
4225 static struct cftype mem_cgroup_legacy_files
[] = {
4227 .name
= "usage_in_bytes",
4228 .private = MEMFILE_PRIVATE(_MEM
, RES_USAGE
),
4229 .read_u64
= mem_cgroup_read_u64
,
4232 .name
= "max_usage_in_bytes",
4233 .private = MEMFILE_PRIVATE(_MEM
, RES_MAX_USAGE
),
4234 .write
= mem_cgroup_reset
,
4235 .read_u64
= mem_cgroup_read_u64
,
4238 .name
= "limit_in_bytes",
4239 .private = MEMFILE_PRIVATE(_MEM
, RES_LIMIT
),
4240 .write
= mem_cgroup_write
,
4241 .read_u64
= mem_cgroup_read_u64
,
4244 .name
= "soft_limit_in_bytes",
4245 .private = MEMFILE_PRIVATE(_MEM
, RES_SOFT_LIMIT
),
4246 .write
= mem_cgroup_write
,
4247 .read_u64
= mem_cgroup_read_u64
,
4251 .private = MEMFILE_PRIVATE(_MEM
, RES_FAILCNT
),
4252 .write
= mem_cgroup_reset
,
4253 .read_u64
= mem_cgroup_read_u64
,
4257 .seq_show
= memcg_stat_show
,
4260 .name
= "force_empty",
4261 .write
= mem_cgroup_force_empty_write
,
4264 .name
= "use_hierarchy",
4265 .write_u64
= mem_cgroup_hierarchy_write
,
4266 .read_u64
= mem_cgroup_hierarchy_read
,
4269 .name
= "cgroup.event_control", /* XXX: for compat */
4270 .write
= memcg_write_event_control
,
4271 .flags
= CFTYPE_NO_PREFIX
,
4275 .name
= "swappiness",
4276 .read_u64
= mem_cgroup_swappiness_read
,
4277 .write_u64
= mem_cgroup_swappiness_write
,
4280 .name
= "move_charge_at_immigrate",
4281 .read_u64
= mem_cgroup_move_charge_read
,
4282 .write_u64
= mem_cgroup_move_charge_write
,
4285 .name
= "oom_control",
4286 .seq_show
= mem_cgroup_oom_control_read
,
4287 .write_u64
= mem_cgroup_oom_control_write
,
4288 .private = MEMFILE_PRIVATE(_OOM_TYPE
, OOM_CONTROL
),
4291 .name
= "pressure_level",
4295 .name
= "numa_stat",
4296 .seq_show
= memcg_numa_stat_show
,
4299 #ifdef CONFIG_MEMCG_KMEM
4301 .name
= "kmem.limit_in_bytes",
4302 .private = MEMFILE_PRIVATE(_KMEM
, RES_LIMIT
),
4303 .write
= mem_cgroup_write
,
4304 .read_u64
= mem_cgroup_read_u64
,
4307 .name
= "kmem.usage_in_bytes",
4308 .private = MEMFILE_PRIVATE(_KMEM
, RES_USAGE
),
4309 .read_u64
= mem_cgroup_read_u64
,
4312 .name
= "kmem.failcnt",
4313 .private = MEMFILE_PRIVATE(_KMEM
, RES_FAILCNT
),
4314 .write
= mem_cgroup_reset
,
4315 .read_u64
= mem_cgroup_read_u64
,
4318 .name
= "kmem.max_usage_in_bytes",
4319 .private = MEMFILE_PRIVATE(_KMEM
, RES_MAX_USAGE
),
4320 .write
= mem_cgroup_reset
,
4321 .read_u64
= mem_cgroup_read_u64
,
4323 #ifdef CONFIG_SLABINFO
4325 .name
= "kmem.slabinfo",
4326 .seq_start
= slab_start
,
4327 .seq_next
= slab_next
,
4328 .seq_stop
= slab_stop
,
4329 .seq_show
= memcg_slab_show
,
4333 { }, /* terminate */
4336 static int alloc_mem_cgroup_per_zone_info(struct mem_cgroup
*memcg
, int node
)
4338 struct mem_cgroup_per_node
*pn
;
4339 struct mem_cgroup_per_zone
*mz
;
4340 int zone
, tmp
= node
;
4342 * This routine is called against possible nodes.
4343 * But it's BUG to call kmalloc() against offline node.
4345 * TODO: this routine can waste much memory for nodes which will
4346 * never be onlined. It's better to use memory hotplug callback
4349 if (!node_state(node
, N_NORMAL_MEMORY
))
4351 pn
= kzalloc_node(sizeof(*pn
), GFP_KERNEL
, tmp
);
4355 for (zone
= 0; zone
< MAX_NR_ZONES
; zone
++) {
4356 mz
= &pn
->zoneinfo
[zone
];
4357 lruvec_init(&mz
->lruvec
);
4358 mz
->usage_in_excess
= 0;
4359 mz
->on_tree
= false;
4362 memcg
->nodeinfo
[node
] = pn
;
4366 static void free_mem_cgroup_per_zone_info(struct mem_cgroup
*memcg
, int node
)
4368 kfree(memcg
->nodeinfo
[node
]);
4371 static struct mem_cgroup
*mem_cgroup_alloc(void)
4373 struct mem_cgroup
*memcg
;
4376 size
= sizeof(struct mem_cgroup
);
4377 size
+= nr_node_ids
* sizeof(struct mem_cgroup_per_node
*);
4379 memcg
= kzalloc(size
, GFP_KERNEL
);
4383 memcg
->stat
= alloc_percpu(struct mem_cgroup_stat_cpu
);
4386 spin_lock_init(&memcg
->pcp_counter_lock
);
4395 * At destroying mem_cgroup, references from swap_cgroup can remain.
4396 * (scanning all at force_empty is too costly...)
4398 * Instead of clearing all references at force_empty, we remember
4399 * the number of reference from swap_cgroup and free mem_cgroup when
4400 * it goes down to 0.
4402 * Removal of cgroup itself succeeds regardless of refs from swap.
4405 static void __mem_cgroup_free(struct mem_cgroup
*memcg
)
4409 mem_cgroup_remove_from_trees(memcg
);
4412 free_mem_cgroup_per_zone_info(memcg
, node
);
4414 free_percpu(memcg
->stat
);
4419 * Returns the parent mem_cgroup in memcgroup hierarchy with hierarchy enabled.
4421 struct mem_cgroup
*parent_mem_cgroup(struct mem_cgroup
*memcg
)
4423 if (!memcg
->memory
.parent
)
4425 return mem_cgroup_from_counter(memcg
->memory
.parent
, memory
);
4427 EXPORT_SYMBOL(parent_mem_cgroup
);
4429 static struct cgroup_subsys_state
* __ref
4430 mem_cgroup_css_alloc(struct cgroup_subsys_state
*parent_css
)
4432 struct mem_cgroup
*memcg
;
4433 long error
= -ENOMEM
;
4436 memcg
= mem_cgroup_alloc();
4438 return ERR_PTR(error
);
4441 if (alloc_mem_cgroup_per_zone_info(memcg
, node
))
4445 if (parent_css
== NULL
) {
4446 root_mem_cgroup
= memcg
;
4447 page_counter_init(&memcg
->memory
, NULL
);
4448 memcg
->high
= PAGE_COUNTER_MAX
;
4449 memcg
->soft_limit
= PAGE_COUNTER_MAX
;
4450 page_counter_init(&memcg
->memsw
, NULL
);
4451 page_counter_init(&memcg
->kmem
, NULL
);
4454 memcg
->last_scanned_node
= MAX_NUMNODES
;
4455 INIT_LIST_HEAD(&memcg
->oom_notify
);
4456 memcg
->move_charge_at_immigrate
= 0;
4457 mutex_init(&memcg
->thresholds_lock
);
4458 spin_lock_init(&memcg
->move_lock
);
4459 vmpressure_init(&memcg
->vmpressure
);
4460 INIT_LIST_HEAD(&memcg
->event_list
);
4461 spin_lock_init(&memcg
->event_list_lock
);
4462 #ifdef CONFIG_MEMCG_KMEM
4463 memcg
->kmemcg_id
= -1;
4469 __mem_cgroup_free(memcg
);
4470 return ERR_PTR(error
);
4474 mem_cgroup_css_online(struct cgroup_subsys_state
*css
)
4476 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
4477 struct mem_cgroup
*parent
= mem_cgroup_from_css(css
->parent
);
4480 if (css
->id
> MEM_CGROUP_ID_MAX
)
4486 mutex_lock(&memcg_create_mutex
);
4488 memcg
->use_hierarchy
= parent
->use_hierarchy
;
4489 memcg
->oom_kill_disable
= parent
->oom_kill_disable
;
4490 memcg
->swappiness
= mem_cgroup_swappiness(parent
);
4492 if (parent
->use_hierarchy
) {
4493 page_counter_init(&memcg
->memory
, &parent
->memory
);
4494 memcg
->high
= PAGE_COUNTER_MAX
;
4495 memcg
->soft_limit
= PAGE_COUNTER_MAX
;
4496 page_counter_init(&memcg
->memsw
, &parent
->memsw
);
4497 page_counter_init(&memcg
->kmem
, &parent
->kmem
);
4500 * No need to take a reference to the parent because cgroup
4501 * core guarantees its existence.
4504 page_counter_init(&memcg
->memory
, NULL
);
4505 memcg
->high
= PAGE_COUNTER_MAX
;
4506 memcg
->soft_limit
= PAGE_COUNTER_MAX
;
4507 page_counter_init(&memcg
->memsw
, NULL
);
4508 page_counter_init(&memcg
->kmem
, NULL
);
4510 * Deeper hierachy with use_hierarchy == false doesn't make
4511 * much sense so let cgroup subsystem know about this
4512 * unfortunate state in our controller.
4514 if (parent
!= root_mem_cgroup
)
4515 memory_cgrp_subsys
.broken_hierarchy
= true;
4517 mutex_unlock(&memcg_create_mutex
);
4519 ret
= memcg_init_kmem(memcg
, &memory_cgrp_subsys
);
4524 * Make sure the memcg is initialized: mem_cgroup_iter()
4525 * orders reading memcg->initialized against its callers
4526 * reading the memcg members.
4528 smp_store_release(&memcg
->initialized
, 1);
4533 static void mem_cgroup_css_offline(struct cgroup_subsys_state
*css
)
4535 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
4536 struct mem_cgroup_event
*event
, *tmp
;
4539 * Unregister events and notify userspace.
4540 * Notify userspace about cgroup removing only after rmdir of cgroup
4541 * directory to avoid race between userspace and kernelspace.
4543 spin_lock(&memcg
->event_list_lock
);
4544 list_for_each_entry_safe(event
, tmp
, &memcg
->event_list
, list
) {
4545 list_del_init(&event
->list
);
4546 schedule_work(&event
->remove
);
4548 spin_unlock(&memcg
->event_list_lock
);
4550 vmpressure_cleanup(&memcg
->vmpressure
);
4552 memcg_deactivate_kmem(memcg
);
4555 static void mem_cgroup_css_free(struct cgroup_subsys_state
*css
)
4557 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
4559 memcg_destroy_kmem(memcg
);
4560 __mem_cgroup_free(memcg
);
4564 * mem_cgroup_css_reset - reset the states of a mem_cgroup
4565 * @css: the target css
4567 * Reset the states of the mem_cgroup associated with @css. This is
4568 * invoked when the userland requests disabling on the default hierarchy
4569 * but the memcg is pinned through dependency. The memcg should stop
4570 * applying policies and should revert to the vanilla state as it may be
4571 * made visible again.
4573 * The current implementation only resets the essential configurations.
4574 * This needs to be expanded to cover all the visible parts.
4576 static void mem_cgroup_css_reset(struct cgroup_subsys_state
*css
)
4578 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
4580 mem_cgroup_resize_limit(memcg
, PAGE_COUNTER_MAX
);
4581 mem_cgroup_resize_memsw_limit(memcg
, PAGE_COUNTER_MAX
);
4582 memcg_update_kmem_limit(memcg
, PAGE_COUNTER_MAX
);
4584 memcg
->high
= PAGE_COUNTER_MAX
;
4585 memcg
->soft_limit
= PAGE_COUNTER_MAX
;
4589 /* Handlers for move charge at task migration. */
4590 static int mem_cgroup_do_precharge(unsigned long count
)
4594 /* Try a single bulk charge without reclaim first */
4595 ret
= try_charge(mc
.to
, GFP_KERNEL
& ~__GFP_WAIT
, count
);
4597 mc
.precharge
+= count
;
4600 if (ret
== -EINTR
) {
4601 cancel_charge(root_mem_cgroup
, count
);
4605 /* Try charges one by one with reclaim */
4607 ret
= try_charge(mc
.to
, GFP_KERNEL
& ~__GFP_NORETRY
, 1);
4609 * In case of failure, any residual charges against
4610 * mc.to will be dropped by mem_cgroup_clear_mc()
4611 * later on. However, cancel any charges that are
4612 * bypassed to root right away or they'll be lost.
4615 cancel_charge(root_mem_cgroup
, 1);
4625 * get_mctgt_type - get target type of moving charge
4626 * @vma: the vma the pte to be checked belongs
4627 * @addr: the address corresponding to the pte to be checked
4628 * @ptent: the pte to be checked
4629 * @target: the pointer the target page or swap ent will be stored(can be NULL)
4632 * 0(MC_TARGET_NONE): if the pte is not a target for move charge.
4633 * 1(MC_TARGET_PAGE): if the page corresponding to this pte is a target for
4634 * move charge. if @target is not NULL, the page is stored in target->page
4635 * with extra refcnt got(Callers should handle it).
4636 * 2(MC_TARGET_SWAP): if the swap entry corresponding to this pte is a
4637 * target for charge migration. if @target is not NULL, the entry is stored
4640 * Called with pte lock held.
4647 enum mc_target_type
{
4653 static struct page
*mc_handle_present_pte(struct vm_area_struct
*vma
,
4654 unsigned long addr
, pte_t ptent
)
4656 struct page
*page
= vm_normal_page(vma
, addr
, ptent
);
4658 if (!page
|| !page_mapped(page
))
4660 if (PageAnon(page
)) {
4661 if (!(mc
.flags
& MOVE_ANON
))
4664 if (!(mc
.flags
& MOVE_FILE
))
4667 if (!get_page_unless_zero(page
))
4674 static struct page
*mc_handle_swap_pte(struct vm_area_struct
*vma
,
4675 unsigned long addr
, pte_t ptent
, swp_entry_t
*entry
)
4677 struct page
*page
= NULL
;
4678 swp_entry_t ent
= pte_to_swp_entry(ptent
);
4680 if (!(mc
.flags
& MOVE_ANON
) || non_swap_entry(ent
))
4683 * Because lookup_swap_cache() updates some statistics counter,
4684 * we call find_get_page() with swapper_space directly.
4686 page
= find_get_page(swap_address_space(ent
), ent
.val
);
4687 if (do_swap_account
)
4688 entry
->val
= ent
.val
;
4693 static struct page
*mc_handle_swap_pte(struct vm_area_struct
*vma
,
4694 unsigned long addr
, pte_t ptent
, swp_entry_t
*entry
)
4700 static struct page
*mc_handle_file_pte(struct vm_area_struct
*vma
,
4701 unsigned long addr
, pte_t ptent
, swp_entry_t
*entry
)
4703 struct page
*page
= NULL
;
4704 struct address_space
*mapping
;
4707 if (!vma
->vm_file
) /* anonymous vma */
4709 if (!(mc
.flags
& MOVE_FILE
))
4712 mapping
= vma
->vm_file
->f_mapping
;
4713 pgoff
= linear_page_index(vma
, addr
);
4715 /* page is moved even if it's not RSS of this task(page-faulted). */
4717 /* shmem/tmpfs may report page out on swap: account for that too. */
4718 if (shmem_mapping(mapping
)) {
4719 page
= find_get_entry(mapping
, pgoff
);
4720 if (radix_tree_exceptional_entry(page
)) {
4721 swp_entry_t swp
= radix_to_swp_entry(page
);
4722 if (do_swap_account
)
4724 page
= find_get_page(swap_address_space(swp
), swp
.val
);
4727 page
= find_get_page(mapping
, pgoff
);
4729 page
= find_get_page(mapping
, pgoff
);
4735 * mem_cgroup_move_account - move account of the page
4737 * @nr_pages: number of regular pages (>1 for huge pages)
4738 * @from: mem_cgroup which the page is moved from.
4739 * @to: mem_cgroup which the page is moved to. @from != @to.
4741 * The caller must confirm following.
4742 * - page is not on LRU (isolate_page() is useful.)
4743 * - compound_lock is held when nr_pages > 1
4745 * This function doesn't do "charge" to new cgroup and doesn't do "uncharge"
4748 static int mem_cgroup_move_account(struct page
*page
,
4749 unsigned int nr_pages
,
4750 struct mem_cgroup
*from
,
4751 struct mem_cgroup
*to
)
4753 unsigned long flags
;
4756 VM_BUG_ON(from
== to
);
4757 VM_BUG_ON_PAGE(PageLRU(page
), page
);
4759 * The page is isolated from LRU. So, collapse function
4760 * will not handle this page. But page splitting can happen.
4761 * Do this check under compound_page_lock(). The caller should
4765 if (nr_pages
> 1 && !PageTransHuge(page
))
4769 * Prevent mem_cgroup_migrate() from looking at page->mem_cgroup
4770 * of its source page while we change it: page migration takes
4771 * both pages off the LRU, but page cache replacement doesn't.
4773 if (!trylock_page(page
))
4777 if (page
->mem_cgroup
!= from
)
4780 spin_lock_irqsave(&from
->move_lock
, flags
);
4782 if (!PageAnon(page
) && page_mapped(page
)) {
4783 __this_cpu_sub(from
->stat
->count
[MEM_CGROUP_STAT_FILE_MAPPED
],
4785 __this_cpu_add(to
->stat
->count
[MEM_CGROUP_STAT_FILE_MAPPED
],
4789 if (PageWriteback(page
)) {
4790 __this_cpu_sub(from
->stat
->count
[MEM_CGROUP_STAT_WRITEBACK
],
4792 __this_cpu_add(to
->stat
->count
[MEM_CGROUP_STAT_WRITEBACK
],
4797 * It is safe to change page->mem_cgroup here because the page
4798 * is referenced, charged, and isolated - we can't race with
4799 * uncharging, charging, migration, or LRU putback.
4802 /* caller should have done css_get */
4803 page
->mem_cgroup
= to
;
4804 spin_unlock_irqrestore(&from
->move_lock
, flags
);
4808 local_irq_disable();
4809 mem_cgroup_charge_statistics(to
, page
, nr_pages
);
4810 memcg_check_events(to
, page
);
4811 mem_cgroup_charge_statistics(from
, page
, -nr_pages
);
4812 memcg_check_events(from
, page
);
4820 static enum mc_target_type
get_mctgt_type(struct vm_area_struct
*vma
,
4821 unsigned long addr
, pte_t ptent
, union mc_target
*target
)
4823 struct page
*page
= NULL
;
4824 enum mc_target_type ret
= MC_TARGET_NONE
;
4825 swp_entry_t ent
= { .val
= 0 };
4827 if (pte_present(ptent
))
4828 page
= mc_handle_present_pte(vma
, addr
, ptent
);
4829 else if (is_swap_pte(ptent
))
4830 page
= mc_handle_swap_pte(vma
, addr
, ptent
, &ent
);
4831 else if (pte_none(ptent
))
4832 page
= mc_handle_file_pte(vma
, addr
, ptent
, &ent
);
4834 if (!page
&& !ent
.val
)
4838 * Do only loose check w/o serialization.
4839 * mem_cgroup_move_account() checks the page is valid or
4840 * not under LRU exclusion.
4842 if (page
->mem_cgroup
== mc
.from
) {
4843 ret
= MC_TARGET_PAGE
;
4845 target
->page
= page
;
4847 if (!ret
|| !target
)
4850 /* There is a swap entry and a page doesn't exist or isn't charged */
4851 if (ent
.val
&& !ret
&&
4852 mem_cgroup_id(mc
.from
) == lookup_swap_cgroup_id(ent
)) {
4853 ret
= MC_TARGET_SWAP
;
4860 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
4862 * We don't consider swapping or file mapped pages because THP does not
4863 * support them for now.
4864 * Caller should make sure that pmd_trans_huge(pmd) is true.
4866 static enum mc_target_type
get_mctgt_type_thp(struct vm_area_struct
*vma
,
4867 unsigned long addr
, pmd_t pmd
, union mc_target
*target
)
4869 struct page
*page
= NULL
;
4870 enum mc_target_type ret
= MC_TARGET_NONE
;
4872 page
= pmd_page(pmd
);
4873 VM_BUG_ON_PAGE(!page
|| !PageHead(page
), page
);
4874 if (!(mc
.flags
& MOVE_ANON
))
4876 if (page
->mem_cgroup
== mc
.from
) {
4877 ret
= MC_TARGET_PAGE
;
4880 target
->page
= page
;
4886 static inline enum mc_target_type
get_mctgt_type_thp(struct vm_area_struct
*vma
,
4887 unsigned long addr
, pmd_t pmd
, union mc_target
*target
)
4889 return MC_TARGET_NONE
;
4893 static int mem_cgroup_count_precharge_pte_range(pmd_t
*pmd
,
4894 unsigned long addr
, unsigned long end
,
4895 struct mm_walk
*walk
)
4897 struct vm_area_struct
*vma
= walk
->vma
;
4901 if (pmd_trans_huge_lock(pmd
, vma
, &ptl
) == 1) {
4902 if (get_mctgt_type_thp(vma
, addr
, *pmd
, NULL
) == MC_TARGET_PAGE
)
4903 mc
.precharge
+= HPAGE_PMD_NR
;
4908 if (pmd_trans_unstable(pmd
))
4910 pte
= pte_offset_map_lock(vma
->vm_mm
, pmd
, addr
, &ptl
);
4911 for (; addr
!= end
; pte
++, addr
+= PAGE_SIZE
)
4912 if (get_mctgt_type(vma
, addr
, *pte
, NULL
))
4913 mc
.precharge
++; /* increment precharge temporarily */
4914 pte_unmap_unlock(pte
- 1, ptl
);
4920 static unsigned long mem_cgroup_count_precharge(struct mm_struct
*mm
)
4922 unsigned long precharge
;
4924 struct mm_walk mem_cgroup_count_precharge_walk
= {
4925 .pmd_entry
= mem_cgroup_count_precharge_pte_range
,
4928 down_read(&mm
->mmap_sem
);
4929 walk_page_range(0, ~0UL, &mem_cgroup_count_precharge_walk
);
4930 up_read(&mm
->mmap_sem
);
4932 precharge
= mc
.precharge
;
4938 static int mem_cgroup_precharge_mc(struct mm_struct
*mm
)
4940 unsigned long precharge
= mem_cgroup_count_precharge(mm
);
4942 VM_BUG_ON(mc
.moving_task
);
4943 mc
.moving_task
= current
;
4944 return mem_cgroup_do_precharge(precharge
);
4947 /* cancels all extra charges on mc.from and mc.to, and wakes up all waiters. */
4948 static void __mem_cgroup_clear_mc(void)
4950 struct mem_cgroup
*from
= mc
.from
;
4951 struct mem_cgroup
*to
= mc
.to
;
4953 /* we must uncharge all the leftover precharges from mc.to */
4955 cancel_charge(mc
.to
, mc
.precharge
);
4959 * we didn't uncharge from mc.from at mem_cgroup_move_account(), so
4960 * we must uncharge here.
4962 if (mc
.moved_charge
) {
4963 cancel_charge(mc
.from
, mc
.moved_charge
);
4964 mc
.moved_charge
= 0;
4966 /* we must fixup refcnts and charges */
4967 if (mc
.moved_swap
) {
4968 /* uncharge swap account from the old cgroup */
4969 if (!mem_cgroup_is_root(mc
.from
))
4970 page_counter_uncharge(&mc
.from
->memsw
, mc
.moved_swap
);
4973 * we charged both to->memory and to->memsw, so we
4974 * should uncharge to->memory.
4976 if (!mem_cgroup_is_root(mc
.to
))
4977 page_counter_uncharge(&mc
.to
->memory
, mc
.moved_swap
);
4979 css_put_many(&mc
.from
->css
, mc
.moved_swap
);
4981 /* we've already done css_get(mc.to) */
4984 memcg_oom_recover(from
);
4985 memcg_oom_recover(to
);
4986 wake_up_all(&mc
.waitq
);
4989 static void mem_cgroup_clear_mc(void)
4992 * we must clear moving_task before waking up waiters at the end of
4995 mc
.moving_task
= NULL
;
4996 __mem_cgroup_clear_mc();
4997 spin_lock(&mc
.lock
);
5000 spin_unlock(&mc
.lock
);
5003 static int mem_cgroup_can_attach(struct cgroup_subsys_state
*css
,
5004 struct cgroup_taskset
*tset
)
5006 struct task_struct
*p
= cgroup_taskset_first(tset
);
5008 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
5009 unsigned long move_flags
;
5012 * We are now commited to this value whatever it is. Changes in this
5013 * tunable will only affect upcoming migrations, not the current one.
5014 * So we need to save it, and keep it going.
5016 move_flags
= READ_ONCE(memcg
->move_charge_at_immigrate
);
5018 struct mm_struct
*mm
;
5019 struct mem_cgroup
*from
= mem_cgroup_from_task(p
);
5021 VM_BUG_ON(from
== memcg
);
5023 mm
= get_task_mm(p
);
5026 /* We move charges only when we move a owner of the mm */
5027 if (mm
->owner
== p
) {
5030 VM_BUG_ON(mc
.precharge
);
5031 VM_BUG_ON(mc
.moved_charge
);
5032 VM_BUG_ON(mc
.moved_swap
);
5034 spin_lock(&mc
.lock
);
5037 mc
.flags
= move_flags
;
5038 spin_unlock(&mc
.lock
);
5039 /* We set mc.moving_task later */
5041 ret
= mem_cgroup_precharge_mc(mm
);
5043 mem_cgroup_clear_mc();
5050 static void mem_cgroup_cancel_attach(struct cgroup_subsys_state
*css
,
5051 struct cgroup_taskset
*tset
)
5054 mem_cgroup_clear_mc();
5057 static int mem_cgroup_move_charge_pte_range(pmd_t
*pmd
,
5058 unsigned long addr
, unsigned long end
,
5059 struct mm_walk
*walk
)
5062 struct vm_area_struct
*vma
= walk
->vma
;
5065 enum mc_target_type target_type
;
5066 union mc_target target
;
5070 * We don't take compound_lock() here but no race with splitting thp
5072 * - if pmd_trans_huge_lock() returns 1, the relevant thp is not
5073 * under splitting, which means there's no concurrent thp split,
5074 * - if another thread runs into split_huge_page() just after we
5075 * entered this if-block, the thread must wait for page table lock
5076 * to be unlocked in __split_huge_page_splitting(), where the main
5077 * part of thp split is not executed yet.
5079 if (pmd_trans_huge_lock(pmd
, vma
, &ptl
) == 1) {
5080 if (mc
.precharge
< HPAGE_PMD_NR
) {
5084 target_type
= get_mctgt_type_thp(vma
, addr
, *pmd
, &target
);
5085 if (target_type
== MC_TARGET_PAGE
) {
5087 if (!isolate_lru_page(page
)) {
5088 if (!mem_cgroup_move_account(page
, HPAGE_PMD_NR
,
5090 mc
.precharge
-= HPAGE_PMD_NR
;
5091 mc
.moved_charge
+= HPAGE_PMD_NR
;
5093 putback_lru_page(page
);
5101 if (pmd_trans_unstable(pmd
))
5104 pte
= pte_offset_map_lock(vma
->vm_mm
, pmd
, addr
, &ptl
);
5105 for (; addr
!= end
; addr
+= PAGE_SIZE
) {
5106 pte_t ptent
= *(pte
++);
5112 switch (get_mctgt_type(vma
, addr
, ptent
, &target
)) {
5113 case MC_TARGET_PAGE
:
5115 if (isolate_lru_page(page
))
5117 if (!mem_cgroup_move_account(page
, 1, mc
.from
, mc
.to
)) {
5119 /* we uncharge from mc.from later. */
5122 putback_lru_page(page
);
5123 put
: /* get_mctgt_type() gets the page */
5126 case MC_TARGET_SWAP
:
5128 if (!mem_cgroup_move_swap_account(ent
, mc
.from
, mc
.to
)) {
5130 /* we fixup refcnts and charges later. */
5138 pte_unmap_unlock(pte
- 1, ptl
);
5143 * We have consumed all precharges we got in can_attach().
5144 * We try charge one by one, but don't do any additional
5145 * charges to mc.to if we have failed in charge once in attach()
5148 ret
= mem_cgroup_do_precharge(1);
5156 static void mem_cgroup_move_charge(struct mm_struct
*mm
)
5158 struct mm_walk mem_cgroup_move_charge_walk
= {
5159 .pmd_entry
= mem_cgroup_move_charge_pte_range
,
5163 lru_add_drain_all();
5165 * Signal mem_cgroup_begin_page_stat() to take the memcg's
5166 * move_lock while we're moving its pages to another memcg.
5167 * Then wait for already started RCU-only updates to finish.
5169 atomic_inc(&mc
.from
->moving_account
);
5172 if (unlikely(!down_read_trylock(&mm
->mmap_sem
))) {
5174 * Someone who are holding the mmap_sem might be waiting in
5175 * waitq. So we cancel all extra charges, wake up all waiters,
5176 * and retry. Because we cancel precharges, we might not be able
5177 * to move enough charges, but moving charge is a best-effort
5178 * feature anyway, so it wouldn't be a big problem.
5180 __mem_cgroup_clear_mc();
5185 * When we have consumed all precharges and failed in doing
5186 * additional charge, the page walk just aborts.
5188 walk_page_range(0, ~0UL, &mem_cgroup_move_charge_walk
);
5189 up_read(&mm
->mmap_sem
);
5190 atomic_dec(&mc
.from
->moving_account
);
5193 static void mem_cgroup_move_task(struct cgroup_subsys_state
*css
,
5194 struct cgroup_taskset
*tset
)
5196 struct task_struct
*p
= cgroup_taskset_first(tset
);
5197 struct mm_struct
*mm
= get_task_mm(p
);
5201 mem_cgroup_move_charge(mm
);
5205 mem_cgroup_clear_mc();
5207 #else /* !CONFIG_MMU */
5208 static int mem_cgroup_can_attach(struct cgroup_subsys_state
*css
,
5209 struct cgroup_taskset
*tset
)
5213 static void mem_cgroup_cancel_attach(struct cgroup_subsys_state
*css
,
5214 struct cgroup_taskset
*tset
)
5217 static void mem_cgroup_move_task(struct cgroup_subsys_state
*css
,
5218 struct cgroup_taskset
*tset
)
5224 * Cgroup retains root cgroups across [un]mount cycles making it necessary
5225 * to verify whether we're attached to the default hierarchy on each mount
5228 static void mem_cgroup_bind(struct cgroup_subsys_state
*root_css
)
5231 * use_hierarchy is forced on the default hierarchy. cgroup core
5232 * guarantees that @root doesn't have any children, so turning it
5233 * on for the root memcg is enough.
5235 if (cgroup_on_dfl(root_css
->cgroup
))
5236 root_mem_cgroup
->use_hierarchy
= true;
5238 root_mem_cgroup
->use_hierarchy
= false;
5241 static u64
memory_current_read(struct cgroup_subsys_state
*css
,
5244 return mem_cgroup_usage(mem_cgroup_from_css(css
), false);
5247 static int memory_low_show(struct seq_file
*m
, void *v
)
5249 struct mem_cgroup
*memcg
= mem_cgroup_from_css(seq_css(m
));
5250 unsigned long low
= READ_ONCE(memcg
->low
);
5252 if (low
== PAGE_COUNTER_MAX
)
5253 seq_puts(m
, "max\n");
5255 seq_printf(m
, "%llu\n", (u64
)low
* PAGE_SIZE
);
5260 static ssize_t
memory_low_write(struct kernfs_open_file
*of
,
5261 char *buf
, size_t nbytes
, loff_t off
)
5263 struct mem_cgroup
*memcg
= mem_cgroup_from_css(of_css(of
));
5267 buf
= strstrip(buf
);
5268 err
= page_counter_memparse(buf
, "max", &low
);
5277 static int memory_high_show(struct seq_file
*m
, void *v
)
5279 struct mem_cgroup
*memcg
= mem_cgroup_from_css(seq_css(m
));
5280 unsigned long high
= READ_ONCE(memcg
->high
);
5282 if (high
== PAGE_COUNTER_MAX
)
5283 seq_puts(m
, "max\n");
5285 seq_printf(m
, "%llu\n", (u64
)high
* PAGE_SIZE
);
5290 static ssize_t
memory_high_write(struct kernfs_open_file
*of
,
5291 char *buf
, size_t nbytes
, loff_t off
)
5293 struct mem_cgroup
*memcg
= mem_cgroup_from_css(of_css(of
));
5297 buf
= strstrip(buf
);
5298 err
= page_counter_memparse(buf
, "max", &high
);
5307 static int memory_max_show(struct seq_file
*m
, void *v
)
5309 struct mem_cgroup
*memcg
= mem_cgroup_from_css(seq_css(m
));
5310 unsigned long max
= READ_ONCE(memcg
->memory
.limit
);
5312 if (max
== PAGE_COUNTER_MAX
)
5313 seq_puts(m
, "max\n");
5315 seq_printf(m
, "%llu\n", (u64
)max
* PAGE_SIZE
);
5320 static ssize_t
memory_max_write(struct kernfs_open_file
*of
,
5321 char *buf
, size_t nbytes
, loff_t off
)
5323 struct mem_cgroup
*memcg
= mem_cgroup_from_css(of_css(of
));
5327 buf
= strstrip(buf
);
5328 err
= page_counter_memparse(buf
, "max", &max
);
5332 err
= mem_cgroup_resize_limit(memcg
, max
);
5339 static int memory_events_show(struct seq_file
*m
, void *v
)
5341 struct mem_cgroup
*memcg
= mem_cgroup_from_css(seq_css(m
));
5343 seq_printf(m
, "low %lu\n", mem_cgroup_read_events(memcg
, MEMCG_LOW
));
5344 seq_printf(m
, "high %lu\n", mem_cgroup_read_events(memcg
, MEMCG_HIGH
));
5345 seq_printf(m
, "max %lu\n", mem_cgroup_read_events(memcg
, MEMCG_MAX
));
5346 seq_printf(m
, "oom %lu\n", mem_cgroup_read_events(memcg
, MEMCG_OOM
));
5351 static struct cftype memory_files
[] = {
5354 .read_u64
= memory_current_read
,
5358 .flags
= CFTYPE_NOT_ON_ROOT
,
5359 .seq_show
= memory_low_show
,
5360 .write
= memory_low_write
,
5364 .flags
= CFTYPE_NOT_ON_ROOT
,
5365 .seq_show
= memory_high_show
,
5366 .write
= memory_high_write
,
5370 .flags
= CFTYPE_NOT_ON_ROOT
,
5371 .seq_show
= memory_max_show
,
5372 .write
= memory_max_write
,
5376 .flags
= CFTYPE_NOT_ON_ROOT
,
5377 .seq_show
= memory_events_show
,
5382 struct cgroup_subsys memory_cgrp_subsys
= {
5383 .css_alloc
= mem_cgroup_css_alloc
,
5384 .css_online
= mem_cgroup_css_online
,
5385 .css_offline
= mem_cgroup_css_offline
,
5386 .css_free
= mem_cgroup_css_free
,
5387 .css_reset
= mem_cgroup_css_reset
,
5388 .can_attach
= mem_cgroup_can_attach
,
5389 .cancel_attach
= mem_cgroup_cancel_attach
,
5390 .attach
= mem_cgroup_move_task
,
5391 .bind
= mem_cgroup_bind
,
5392 .dfl_cftypes
= memory_files
,
5393 .legacy_cftypes
= mem_cgroup_legacy_files
,
5398 * mem_cgroup_events - count memory events against a cgroup
5399 * @memcg: the memory cgroup
5400 * @idx: the event index
5401 * @nr: the number of events to account for
5403 void mem_cgroup_events(struct mem_cgroup
*memcg
,
5404 enum mem_cgroup_events_index idx
,
5407 this_cpu_add(memcg
->stat
->events
[idx
], nr
);
5411 * mem_cgroup_low - check if memory consumption is below the normal range
5412 * @root: the highest ancestor to consider
5413 * @memcg: the memory cgroup to check
5415 * Returns %true if memory consumption of @memcg, and that of all
5416 * configurable ancestors up to @root, is below the normal range.
5418 bool mem_cgroup_low(struct mem_cgroup
*root
, struct mem_cgroup
*memcg
)
5420 if (mem_cgroup_disabled())
5424 * The toplevel group doesn't have a configurable range, so
5425 * it's never low when looked at directly, and it is not
5426 * considered an ancestor when assessing the hierarchy.
5429 if (memcg
== root_mem_cgroup
)
5432 if (page_counter_read(&memcg
->memory
) >= memcg
->low
)
5435 while (memcg
!= root
) {
5436 memcg
= parent_mem_cgroup(memcg
);
5438 if (memcg
== root_mem_cgroup
)
5441 if (page_counter_read(&memcg
->memory
) >= memcg
->low
)
5448 * mem_cgroup_try_charge - try charging a page
5449 * @page: page to charge
5450 * @mm: mm context of the victim
5451 * @gfp_mask: reclaim mode
5452 * @memcgp: charged memcg return
5454 * Try to charge @page to the memcg that @mm belongs to, reclaiming
5455 * pages according to @gfp_mask if necessary.
5457 * Returns 0 on success, with *@memcgp pointing to the charged memcg.
5458 * Otherwise, an error code is returned.
5460 * After page->mapping has been set up, the caller must finalize the
5461 * charge with mem_cgroup_commit_charge(). Or abort the transaction
5462 * with mem_cgroup_cancel_charge() in case page instantiation fails.
5464 int mem_cgroup_try_charge(struct page
*page
, struct mm_struct
*mm
,
5465 gfp_t gfp_mask
, struct mem_cgroup
**memcgp
)
5467 struct mem_cgroup
*memcg
= NULL
;
5468 unsigned int nr_pages
= 1;
5471 if (mem_cgroup_disabled())
5474 if (PageSwapCache(page
)) {
5476 * Every swap fault against a single page tries to charge the
5477 * page, bail as early as possible. shmem_unuse() encounters
5478 * already charged pages, too. The USED bit is protected by
5479 * the page lock, which serializes swap cache removal, which
5480 * in turn serializes uncharging.
5482 if (page
->mem_cgroup
)
5486 if (PageTransHuge(page
)) {
5487 nr_pages
<<= compound_order(page
);
5488 VM_BUG_ON_PAGE(!PageTransHuge(page
), page
);
5491 if (do_swap_account
&& PageSwapCache(page
))
5492 memcg
= try_get_mem_cgroup_from_page(page
);
5494 memcg
= get_mem_cgroup_from_mm(mm
);
5496 ret
= try_charge(memcg
, gfp_mask
, nr_pages
);
5498 css_put(&memcg
->css
);
5500 if (ret
== -EINTR
) {
5501 memcg
= root_mem_cgroup
;
5510 * mem_cgroup_commit_charge - commit a page charge
5511 * @page: page to charge
5512 * @memcg: memcg to charge the page to
5513 * @lrucare: page might be on LRU already
5515 * Finalize a charge transaction started by mem_cgroup_try_charge(),
5516 * after page->mapping has been set up. This must happen atomically
5517 * as part of the page instantiation, i.e. under the page table lock
5518 * for anonymous pages, under the page lock for page and swap cache.
5520 * In addition, the page must not be on the LRU during the commit, to
5521 * prevent racing with task migration. If it might be, use @lrucare.
5523 * Use mem_cgroup_cancel_charge() to cancel the transaction instead.
5525 void mem_cgroup_commit_charge(struct page
*page
, struct mem_cgroup
*memcg
,
5528 unsigned int nr_pages
= 1;
5530 VM_BUG_ON_PAGE(!page
->mapping
, page
);
5531 VM_BUG_ON_PAGE(PageLRU(page
) && !lrucare
, page
);
5533 if (mem_cgroup_disabled())
5536 * Swap faults will attempt to charge the same page multiple
5537 * times. But reuse_swap_page() might have removed the page
5538 * from swapcache already, so we can't check PageSwapCache().
5543 commit_charge(page
, memcg
, lrucare
);
5545 if (PageTransHuge(page
)) {
5546 nr_pages
<<= compound_order(page
);
5547 VM_BUG_ON_PAGE(!PageTransHuge(page
), page
);
5550 local_irq_disable();
5551 mem_cgroup_charge_statistics(memcg
, page
, nr_pages
);
5552 memcg_check_events(memcg
, page
);
5555 if (do_swap_account
&& PageSwapCache(page
)) {
5556 swp_entry_t entry
= { .val
= page_private(page
) };
5558 * The swap entry might not get freed for a long time,
5559 * let's not wait for it. The page already received a
5560 * memory+swap charge, drop the swap entry duplicate.
5562 mem_cgroup_uncharge_swap(entry
);
5567 * mem_cgroup_cancel_charge - cancel a page charge
5568 * @page: page to charge
5569 * @memcg: memcg to charge the page to
5571 * Cancel a charge transaction started by mem_cgroup_try_charge().
5573 void mem_cgroup_cancel_charge(struct page
*page
, struct mem_cgroup
*memcg
)
5575 unsigned int nr_pages
= 1;
5577 if (mem_cgroup_disabled())
5580 * Swap faults will attempt to charge the same page multiple
5581 * times. But reuse_swap_page() might have removed the page
5582 * from swapcache already, so we can't check PageSwapCache().
5587 if (PageTransHuge(page
)) {
5588 nr_pages
<<= compound_order(page
);
5589 VM_BUG_ON_PAGE(!PageTransHuge(page
), page
);
5592 cancel_charge(memcg
, nr_pages
);
5595 static void uncharge_batch(struct mem_cgroup
*memcg
, unsigned long pgpgout
,
5596 unsigned long nr_anon
, unsigned long nr_file
,
5597 unsigned long nr_huge
, struct page
*dummy_page
)
5599 unsigned long nr_pages
= nr_anon
+ nr_file
;
5600 unsigned long flags
;
5602 if (!mem_cgroup_is_root(memcg
)) {
5603 page_counter_uncharge(&memcg
->memory
, nr_pages
);
5604 if (do_swap_account
)
5605 page_counter_uncharge(&memcg
->memsw
, nr_pages
);
5606 memcg_oom_recover(memcg
);
5609 local_irq_save(flags
);
5610 __this_cpu_sub(memcg
->stat
->count
[MEM_CGROUP_STAT_RSS
], nr_anon
);
5611 __this_cpu_sub(memcg
->stat
->count
[MEM_CGROUP_STAT_CACHE
], nr_file
);
5612 __this_cpu_sub(memcg
->stat
->count
[MEM_CGROUP_STAT_RSS_HUGE
], nr_huge
);
5613 __this_cpu_add(memcg
->stat
->events
[MEM_CGROUP_EVENTS_PGPGOUT
], pgpgout
);
5614 __this_cpu_add(memcg
->stat
->nr_page_events
, nr_pages
);
5615 memcg_check_events(memcg
, dummy_page
);
5616 local_irq_restore(flags
);
5618 if (!mem_cgroup_is_root(memcg
))
5619 css_put_many(&memcg
->css
, nr_pages
);
5622 static void uncharge_list(struct list_head
*page_list
)
5624 struct mem_cgroup
*memcg
= NULL
;
5625 unsigned long nr_anon
= 0;
5626 unsigned long nr_file
= 0;
5627 unsigned long nr_huge
= 0;
5628 unsigned long pgpgout
= 0;
5629 struct list_head
*next
;
5632 next
= page_list
->next
;
5634 unsigned int nr_pages
= 1;
5636 page
= list_entry(next
, struct page
, lru
);
5637 next
= page
->lru
.next
;
5639 VM_BUG_ON_PAGE(PageLRU(page
), page
);
5640 VM_BUG_ON_PAGE(page_count(page
), page
);
5642 if (!page
->mem_cgroup
)
5646 * Nobody should be changing or seriously looking at
5647 * page->mem_cgroup at this point, we have fully
5648 * exclusive access to the page.
5651 if (memcg
!= page
->mem_cgroup
) {
5653 uncharge_batch(memcg
, pgpgout
, nr_anon
, nr_file
,
5655 pgpgout
= nr_anon
= nr_file
= nr_huge
= 0;
5657 memcg
= page
->mem_cgroup
;
5660 if (PageTransHuge(page
)) {
5661 nr_pages
<<= compound_order(page
);
5662 VM_BUG_ON_PAGE(!PageTransHuge(page
), page
);
5663 nr_huge
+= nr_pages
;
5667 nr_anon
+= nr_pages
;
5669 nr_file
+= nr_pages
;
5671 page
->mem_cgroup
= NULL
;
5674 } while (next
!= page_list
);
5677 uncharge_batch(memcg
, pgpgout
, nr_anon
, nr_file
,
5682 * mem_cgroup_uncharge - uncharge a page
5683 * @page: page to uncharge
5685 * Uncharge a page previously charged with mem_cgroup_try_charge() and
5686 * mem_cgroup_commit_charge().
5688 void mem_cgroup_uncharge(struct page
*page
)
5690 if (mem_cgroup_disabled())
5693 /* Don't touch page->lru of any random page, pre-check: */
5694 if (!page
->mem_cgroup
)
5697 INIT_LIST_HEAD(&page
->lru
);
5698 uncharge_list(&page
->lru
);
5702 * mem_cgroup_uncharge_list - uncharge a list of page
5703 * @page_list: list of pages to uncharge
5705 * Uncharge a list of pages previously charged with
5706 * mem_cgroup_try_charge() and mem_cgroup_commit_charge().
5708 void mem_cgroup_uncharge_list(struct list_head
*page_list
)
5710 if (mem_cgroup_disabled())
5713 if (!list_empty(page_list
))
5714 uncharge_list(page_list
);
5718 * mem_cgroup_migrate - migrate a charge to another page
5719 * @oldpage: currently charged page
5720 * @newpage: page to transfer the charge to
5721 * @lrucare: either or both pages might be on the LRU already
5723 * Migrate the charge from @oldpage to @newpage.
5725 * Both pages must be locked, @newpage->mapping must be set up.
5727 void mem_cgroup_migrate(struct page
*oldpage
, struct page
*newpage
,
5730 struct mem_cgroup
*memcg
;
5733 VM_BUG_ON_PAGE(!PageLocked(oldpage
), oldpage
);
5734 VM_BUG_ON_PAGE(!PageLocked(newpage
), newpage
);
5735 VM_BUG_ON_PAGE(!lrucare
&& PageLRU(oldpage
), oldpage
);
5736 VM_BUG_ON_PAGE(!lrucare
&& PageLRU(newpage
), newpage
);
5737 VM_BUG_ON_PAGE(PageAnon(oldpage
) != PageAnon(newpage
), newpage
);
5738 VM_BUG_ON_PAGE(PageTransHuge(oldpage
) != PageTransHuge(newpage
),
5741 if (mem_cgroup_disabled())
5744 /* Page cache replacement: new page already charged? */
5745 if (newpage
->mem_cgroup
)
5749 * Swapcache readahead pages can get migrated before being
5750 * charged, and migration from compaction can happen to an
5751 * uncharged page when the PFN walker finds a page that
5752 * reclaim just put back on the LRU but has not released yet.
5754 memcg
= oldpage
->mem_cgroup
;
5759 lock_page_lru(oldpage
, &isolated
);
5761 oldpage
->mem_cgroup
= NULL
;
5764 unlock_page_lru(oldpage
, isolated
);
5766 commit_charge(newpage
, memcg
, lrucare
);
5770 * subsys_initcall() for memory controller.
5772 * Some parts like hotcpu_notifier() have to be initialized from this context
5773 * because of lock dependencies (cgroup_lock -> cpu hotplug) but basically
5774 * everything that doesn't depend on a specific mem_cgroup structure should
5775 * be initialized from here.
5777 static int __init
mem_cgroup_init(void)
5781 hotcpu_notifier(memcg_cpu_hotplug_callback
, 0);
5783 for_each_possible_cpu(cpu
)
5784 INIT_WORK(&per_cpu_ptr(&memcg_stock
, cpu
)->work
,
5787 for_each_node(node
) {
5788 struct mem_cgroup_tree_per_node
*rtpn
;
5791 rtpn
= kzalloc_node(sizeof(*rtpn
), GFP_KERNEL
,
5792 node_online(node
) ? node
: NUMA_NO_NODE
);
5794 for (zone
= 0; zone
< MAX_NR_ZONES
; zone
++) {
5795 struct mem_cgroup_tree_per_zone
*rtpz
;
5797 rtpz
= &rtpn
->rb_tree_per_zone
[zone
];
5798 rtpz
->rb_root
= RB_ROOT
;
5799 spin_lock_init(&rtpz
->lock
);
5801 soft_limit_tree
.rb_tree_per_node
[node
] = rtpn
;
5806 subsys_initcall(mem_cgroup_init
);
5808 #ifdef CONFIG_MEMCG_SWAP
5810 * mem_cgroup_swapout - transfer a memsw charge to swap
5811 * @page: page whose memsw charge to transfer
5812 * @entry: swap entry to move the charge to
5814 * Transfer the memsw charge of @page to @entry.
5816 void mem_cgroup_swapout(struct page
*page
, swp_entry_t entry
)
5818 struct mem_cgroup
*memcg
;
5819 unsigned short oldid
;
5821 VM_BUG_ON_PAGE(PageLRU(page
), page
);
5822 VM_BUG_ON_PAGE(page_count(page
), page
);
5824 if (!do_swap_account
)
5827 memcg
= page
->mem_cgroup
;
5829 /* Readahead page, never charged */
5833 oldid
= swap_cgroup_record(entry
, mem_cgroup_id(memcg
));
5834 VM_BUG_ON_PAGE(oldid
, page
);
5835 mem_cgroup_swap_statistics(memcg
, true);
5837 page
->mem_cgroup
= NULL
;
5839 if (!mem_cgroup_is_root(memcg
))
5840 page_counter_uncharge(&memcg
->memory
, 1);
5842 /* Caller disabled preemption with mapping->tree_lock */
5843 mem_cgroup_charge_statistics(memcg
, page
, -1);
5844 memcg_check_events(memcg
, page
);
5848 * mem_cgroup_uncharge_swap - uncharge a swap entry
5849 * @entry: swap entry to uncharge
5851 * Drop the memsw charge associated with @entry.
5853 void mem_cgroup_uncharge_swap(swp_entry_t entry
)
5855 struct mem_cgroup
*memcg
;
5858 if (!do_swap_account
)
5861 id
= swap_cgroup_record(entry
, 0);
5863 memcg
= mem_cgroup_from_id(id
);
5865 if (!mem_cgroup_is_root(memcg
))
5866 page_counter_uncharge(&memcg
->memsw
, 1);
5867 mem_cgroup_swap_statistics(memcg
, false);
5868 css_put(&memcg
->css
);
5873 /* for remember boot option*/
5874 #ifdef CONFIG_MEMCG_SWAP_ENABLED
5875 static int really_do_swap_account __initdata
= 1;
5877 static int really_do_swap_account __initdata
;
5880 static int __init
enable_swap_account(char *s
)
5882 if (!strcmp(s
, "1"))
5883 really_do_swap_account
= 1;
5884 else if (!strcmp(s
, "0"))
5885 really_do_swap_account
= 0;
5888 __setup("swapaccount=", enable_swap_account
);
5890 static struct cftype memsw_cgroup_files
[] = {
5892 .name
= "memsw.usage_in_bytes",
5893 .private = MEMFILE_PRIVATE(_MEMSWAP
, RES_USAGE
),
5894 .read_u64
= mem_cgroup_read_u64
,
5897 .name
= "memsw.max_usage_in_bytes",
5898 .private = MEMFILE_PRIVATE(_MEMSWAP
, RES_MAX_USAGE
),
5899 .write
= mem_cgroup_reset
,
5900 .read_u64
= mem_cgroup_read_u64
,
5903 .name
= "memsw.limit_in_bytes",
5904 .private = MEMFILE_PRIVATE(_MEMSWAP
, RES_LIMIT
),
5905 .write
= mem_cgroup_write
,
5906 .read_u64
= mem_cgroup_read_u64
,
5909 .name
= "memsw.failcnt",
5910 .private = MEMFILE_PRIVATE(_MEMSWAP
, RES_FAILCNT
),
5911 .write
= mem_cgroup_reset
,
5912 .read_u64
= mem_cgroup_read_u64
,
5914 { }, /* terminate */
5917 static int __init
mem_cgroup_swap_init(void)
5919 if (!mem_cgroup_disabled() && really_do_swap_account
) {
5920 do_swap_account
= 1;
5921 WARN_ON(cgroup_add_legacy_cftypes(&memory_cgrp_subsys
,
5922 memsw_cgroup_files
));
5926 subsys_initcall(mem_cgroup_swap_init
);
5928 #endif /* CONFIG_MEMCG_SWAP */