1 /* memcontrol.c - Memory Controller
3 * Copyright IBM Corporation, 2007
4 * Author Balbir Singh <balbir@linux.vnet.ibm.com>
6 * Copyright 2007 OpenVZ SWsoft Inc
7 * Author: Pavel Emelianov <xemul@openvz.org>
10 * Copyright (C) 2009 Nokia Corporation
11 * Author: Kirill A. Shutemov
13 * Kernel Memory Controller
14 * Copyright (C) 2012 Parallels Inc. and Google Inc.
15 * Authors: Glauber Costa and Suleiman Souhlal
17 * This program is free software; you can redistribute it and/or modify
18 * it under the terms of the GNU General Public License as published by
19 * the Free Software Foundation; either version 2 of the License, or
20 * (at your option) any later version.
22 * This program is distributed in the hope that it will be useful,
23 * but WITHOUT ANY WARRANTY; without even the implied warranty of
24 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
25 * GNU General Public License for more details.
28 #include <linux/res_counter.h>
29 #include <linux/memcontrol.h>
30 #include <linux/cgroup.h>
32 #include <linux/hugetlb.h>
33 #include <linux/pagemap.h>
34 #include <linux/smp.h>
35 #include <linux/page-flags.h>
36 #include <linux/backing-dev.h>
37 #include <linux/bit_spinlock.h>
38 #include <linux/rcupdate.h>
39 #include <linux/limits.h>
40 #include <linux/export.h>
41 #include <linux/mutex.h>
42 #include <linux/slab.h>
43 #include <linux/swap.h>
44 #include <linux/swapops.h>
45 #include <linux/spinlock.h>
46 #include <linux/eventfd.h>
47 #include <linux/sort.h>
49 #include <linux/seq_file.h>
50 #include <linux/vmalloc.h>
51 #include <linux/vmpressure.h>
52 #include <linux/mm_inline.h>
53 #include <linux/page_cgroup.h>
54 #include <linux/cpu.h>
55 #include <linux/oom.h>
59 #include <net/tcp_memcontrol.h>
61 #include <asm/uaccess.h>
63 #include <trace/events/vmscan.h>
65 struct cgroup_subsys mem_cgroup_subsys __read_mostly;
66 EXPORT_SYMBOL(mem_cgroup_subsys);
68 #define MEM_CGROUP_RECLAIM_RETRIES 5
69 static struct mem_cgroup *root_mem_cgroup __read_mostly;
71 #ifdef CONFIG_MEMCG_SWAP
72 /* Turned on only when memory cgroup is enabled && really_do_swap_account = 1 */
73 int do_swap_account __read_mostly;
75 /* for remember boot option*/
76 #ifdef CONFIG_MEMCG_SWAP_ENABLED
77 static int really_do_swap_account __initdata = 1;
79 static int really_do_swap_account __initdata = 0;
83 #define do_swap_account 0
88 * Statistics for memory cgroup.
90 enum mem_cgroup_stat_index {
92 * For MEM_CONTAINER_TYPE_ALL, usage = pagecache + rss.
94 MEM_CGROUP_STAT_CACHE, /* # of pages charged as cache */
95 MEM_CGROUP_STAT_RSS, /* # of pages charged as anon rss */
96 MEM_CGROUP_STAT_RSS_HUGE, /* # of pages charged as anon huge */
97 MEM_CGROUP_STAT_FILE_MAPPED, /* # of pages charged as file rss */
98 MEM_CGROUP_STAT_SWAP, /* # of pages, swapped out */
99 MEM_CGROUP_STAT_NSTATS,
102 static const char * const mem_cgroup_stat_names[] = {
110 enum mem_cgroup_events_index {
111 MEM_CGROUP_EVENTS_PGPGIN, /* # of pages paged in */
112 MEM_CGROUP_EVENTS_PGPGOUT, /* # of pages paged out */
113 MEM_CGROUP_EVENTS_PGFAULT, /* # of page-faults */
114 MEM_CGROUP_EVENTS_PGMAJFAULT, /* # of major page-faults */
115 MEM_CGROUP_EVENTS_NSTATS,
118 static const char * const mem_cgroup_events_names[] = {
125 static const char * const mem_cgroup_lru_names[] = {
134 * Per memcg event counter is incremented at every pagein/pageout. With THP,
135 * it will be incremated by the number of pages. This counter is used for
136 * for trigger some periodic events. This is straightforward and better
137 * than using jiffies etc. to handle periodic memcg event.
139 enum mem_cgroup_events_target {
140 MEM_CGROUP_TARGET_THRESH,
141 MEM_CGROUP_TARGET_NUMAINFO,
144 #define THRESHOLDS_EVENTS_TARGET 128
145 #define SOFTLIMIT_EVENTS_TARGET 1024
146 #define NUMAINFO_EVENTS_TARGET 1024
148 struct mem_cgroup_stat_cpu {
149 long count[MEM_CGROUP_STAT_NSTATS];
150 unsigned long events[MEM_CGROUP_EVENTS_NSTATS];
151 unsigned long nr_page_events;
152 unsigned long targets[MEM_CGROUP_NTARGETS];
155 struct mem_cgroup_reclaim_iter {
157 * last scanned hierarchy member. Valid only if last_dead_count
158 * matches memcg->dead_count of the hierarchy root group.
160 struct mem_cgroup *last_visited;
161 unsigned long last_dead_count;
163 /* scan generation, increased every round-trip */
164 unsigned int generation;
168 * per-zone information in memory controller.
170 struct mem_cgroup_per_zone {
171 struct lruvec lruvec;
172 unsigned long lru_size[NR_LRU_LISTS];
174 struct mem_cgroup_reclaim_iter reclaim_iter[DEF_PRIORITY + 1];
176 struct mem_cgroup *memcg; /* Back pointer, we cannot */
177 /* use container_of */
180 struct mem_cgroup_per_node {
181 struct mem_cgroup_per_zone zoneinfo[MAX_NR_ZONES];
184 struct mem_cgroup_threshold {
185 struct eventfd_ctx *eventfd;
190 struct mem_cgroup_threshold_ary {
191 /* An array index points to threshold just below or equal to usage. */
192 int current_threshold;
193 /* Size of entries[] */
195 /* Array of thresholds */
196 struct mem_cgroup_threshold entries[0];
199 struct mem_cgroup_thresholds {
200 /* Primary thresholds array */
201 struct mem_cgroup_threshold_ary *primary;
203 * Spare threshold array.
204 * This is needed to make mem_cgroup_unregister_event() "never fail".
205 * It must be able to store at least primary->size - 1 entries.
207 struct mem_cgroup_threshold_ary *spare;
211 struct mem_cgroup_eventfd_list {
212 struct list_head list;
213 struct eventfd_ctx *eventfd;
216 static void mem_cgroup_threshold(struct mem_cgroup *memcg);
217 static void mem_cgroup_oom_notify(struct mem_cgroup *memcg);
220 * The memory controller data structure. The memory controller controls both
221 * page cache and RSS per cgroup. We would eventually like to provide
222 * statistics based on the statistics developed by Rik Van Riel for clock-pro,
223 * to help the administrator determine what knobs to tune.
225 * TODO: Add a water mark for the memory controller. Reclaim will begin when
226 * we hit the water mark. May be even add a low water mark, such that
227 * no reclaim occurs from a cgroup at it's low water mark, this is
228 * a feature that will be implemented much later in the future.
231 struct cgroup_subsys_state css;
233 * the counter to account for memory usage
235 struct res_counter res;
237 /* vmpressure notifications */
238 struct vmpressure vmpressure;
241 * the counter to account for mem+swap usage.
243 struct res_counter memsw;
246 * the counter to account for kernel memory usage.
248 struct res_counter kmem;
250 * Should the accounting and control be hierarchical, per subtree?
253 unsigned long kmem_account_flags; /* See KMEM_ACCOUNTED_*, below */
259 /* OOM-Killer disable */
260 int oom_kill_disable;
262 /* set when res.limit == memsw.limit */
263 bool memsw_is_minimum;
265 /* protect arrays of thresholds */
266 struct mutex thresholds_lock;
268 /* thresholds for memory usage. RCU-protected */
269 struct mem_cgroup_thresholds thresholds;
271 /* thresholds for mem+swap usage. RCU-protected */
272 struct mem_cgroup_thresholds memsw_thresholds;
274 /* For oom notifier event fd */
275 struct list_head oom_notify;
278 * Should we move charges of a task when a task is moved into this
279 * mem_cgroup ? And what type of charges should we move ?
281 unsigned long move_charge_at_immigrate;
283 * set > 0 if pages under this cgroup are moving to other cgroup.
285 atomic_t moving_account;
286 /* taken only while moving_account > 0 */
287 spinlock_t move_lock;
291 struct mem_cgroup_stat_cpu __percpu *stat;
293 * used when a cpu is offlined or other synchronizations
294 * See mem_cgroup_read_stat().
296 struct mem_cgroup_stat_cpu nocpu_base;
297 spinlock_t pcp_counter_lock;
300 #if defined(CONFIG_MEMCG_KMEM) && defined(CONFIG_INET)
301 struct tcp_memcontrol tcp_mem;
303 #if defined(CONFIG_MEMCG_KMEM)
304 /* analogous to slab_common's slab_caches list. per-memcg */
305 struct list_head memcg_slab_caches;
306 /* Not a spinlock, we can take a lot of time walking the list */
307 struct mutex slab_caches_mutex;
308 /* Index in the kmem_cache->memcg_params->memcg_caches array */
312 int last_scanned_node;
314 nodemask_t scan_nodes;
315 atomic_t numainfo_events;
316 atomic_t numainfo_updating;
319 struct mem_cgroup_per_node *nodeinfo[0];
320 /* WARNING: nodeinfo must be the last member here */
323 static size_t memcg_size(void)
325 return sizeof(struct mem_cgroup) +
326 nr_node_ids * sizeof(struct mem_cgroup_per_node);
329 /* internal only representation about the status of kmem accounting. */
331 KMEM_ACCOUNTED_ACTIVE = 0, /* accounted by this cgroup itself */
332 KMEM_ACCOUNTED_ACTIVATED, /* static key enabled. */
333 KMEM_ACCOUNTED_DEAD, /* dead memcg with pending kmem charges */
336 /* We account when limit is on, but only after call sites are patched */
337 #define KMEM_ACCOUNTED_MASK \
338 ((1 << KMEM_ACCOUNTED_ACTIVE) | (1 << KMEM_ACCOUNTED_ACTIVATED))
340 #ifdef CONFIG_MEMCG_KMEM
341 static inline void memcg_kmem_set_active(struct mem_cgroup *memcg)
343 set_bit(KMEM_ACCOUNTED_ACTIVE, &memcg->kmem_account_flags);
346 static bool memcg_kmem_is_active(struct mem_cgroup *memcg)
348 return test_bit(KMEM_ACCOUNTED_ACTIVE, &memcg->kmem_account_flags);
351 static void memcg_kmem_set_activated(struct mem_cgroup *memcg)
353 set_bit(KMEM_ACCOUNTED_ACTIVATED, &memcg->kmem_account_flags);
356 static void memcg_kmem_clear_activated(struct mem_cgroup *memcg)
358 clear_bit(KMEM_ACCOUNTED_ACTIVATED, &memcg->kmem_account_flags);
361 static void memcg_kmem_mark_dead(struct mem_cgroup *memcg)
364 * Our caller must use css_get() first, because memcg_uncharge_kmem()
365 * will call css_put() if it sees the memcg is dead.
368 if (test_bit(KMEM_ACCOUNTED_ACTIVE, &memcg->kmem_account_flags))
369 set_bit(KMEM_ACCOUNTED_DEAD, &memcg->kmem_account_flags);
372 static bool memcg_kmem_test_and_clear_dead(struct mem_cgroup *memcg)
374 return test_and_clear_bit(KMEM_ACCOUNTED_DEAD,
375 &memcg->kmem_account_flags);
379 /* Stuffs for move charges at task migration. */
381 * Types of charges to be moved. "move_charge_at_immitgrate" and
382 * "immigrate_flags" are treated as a left-shifted bitmap of these types.
385 MOVE_CHARGE_TYPE_ANON, /* private anonymous page and swap of it */
386 MOVE_CHARGE_TYPE_FILE, /* file page(including tmpfs) and swap of it */
390 /* "mc" and its members are protected by cgroup_mutex */
391 static struct move_charge_struct {
392 spinlock_t lock; /* for from, to */
393 struct mem_cgroup *from;
394 struct mem_cgroup *to;
395 unsigned long immigrate_flags;
396 unsigned long precharge;
397 unsigned long moved_charge;
398 unsigned long moved_swap;
399 struct task_struct *moving_task; /* a task moving charges */
400 wait_queue_head_t waitq; /* a waitq for other context */
402 .lock = __SPIN_LOCK_UNLOCKED(mc.lock),
403 .waitq = __WAIT_QUEUE_HEAD_INITIALIZER(mc.waitq),
406 static bool move_anon(void)
408 return test_bit(MOVE_CHARGE_TYPE_ANON, &mc.immigrate_flags);
411 static bool move_file(void)
413 return test_bit(MOVE_CHARGE_TYPE_FILE, &mc.immigrate_flags);
417 * Maximum loops in mem_cgroup_hierarchical_reclaim(), used for soft
418 * limit reclaim to prevent infinite loops, if they ever occur.
420 #define MEM_CGROUP_MAX_RECLAIM_LOOPS 100
423 MEM_CGROUP_CHARGE_TYPE_CACHE = 0,
424 MEM_CGROUP_CHARGE_TYPE_ANON,
425 MEM_CGROUP_CHARGE_TYPE_SWAPOUT, /* for accounting swapcache */
426 MEM_CGROUP_CHARGE_TYPE_DROP, /* a page was unused swap cache */
430 /* for encoding cft->private value on file */
438 #define MEMFILE_PRIVATE(x, val) ((x) << 16 | (val))
439 #define MEMFILE_TYPE(val) ((val) >> 16 & 0xffff)
440 #define MEMFILE_ATTR(val) ((val) & 0xffff)
441 /* Used for OOM nofiier */
442 #define OOM_CONTROL (0)
445 * Reclaim flags for mem_cgroup_hierarchical_reclaim
447 #define MEM_CGROUP_RECLAIM_NOSWAP_BIT 0x0
448 #define MEM_CGROUP_RECLAIM_NOSWAP (1 << MEM_CGROUP_RECLAIM_NOSWAP_BIT)
449 #define MEM_CGROUP_RECLAIM_SHRINK_BIT 0x1
450 #define MEM_CGROUP_RECLAIM_SHRINK (1 << MEM_CGROUP_RECLAIM_SHRINK_BIT)
453 * The memcg_create_mutex will be held whenever a new cgroup is created.
454 * As a consequence, any change that needs to protect against new child cgroups
455 * appearing has to hold it as well.
457 static DEFINE_MUTEX(memcg_create_mutex);
459 struct mem_cgroup *mem_cgroup_from_css(struct cgroup_subsys_state *s)
461 return s ? container_of(s, struct mem_cgroup, css) : NULL;
464 /* Some nice accessors for the vmpressure. */
465 struct vmpressure *memcg_to_vmpressure(struct mem_cgroup *memcg)
468 memcg = root_mem_cgroup;
469 return &memcg->vmpressure;
472 struct cgroup_subsys_state *vmpressure_to_css(struct vmpressure *vmpr)
474 return &container_of(vmpr, struct mem_cgroup, vmpressure)->css;
477 struct vmpressure *css_to_vmpressure(struct cgroup_subsys_state *css)
479 return &mem_cgroup_from_css(css)->vmpressure;
482 static inline bool mem_cgroup_is_root(struct mem_cgroup *memcg)
484 return (memcg == root_mem_cgroup);
487 /* Writing them here to avoid exposing memcg's inner layout */
488 #if defined(CONFIG_INET) && defined(CONFIG_MEMCG_KMEM)
490 void sock_update_memcg(struct sock *sk)
492 if (mem_cgroup_sockets_enabled) {
493 struct mem_cgroup *memcg;
494 struct cg_proto *cg_proto;
496 BUG_ON(!sk->sk_prot->proto_cgroup);
498 /* Socket cloning can throw us here with sk_cgrp already
499 * filled. It won't however, necessarily happen from
500 * process context. So the test for root memcg given
501 * the current task's memcg won't help us in this case.
503 * Respecting the original socket's memcg is a better
504 * decision in this case.
507 BUG_ON(mem_cgroup_is_root(sk->sk_cgrp->memcg));
508 css_get(&sk->sk_cgrp->memcg->css);
513 memcg = mem_cgroup_from_task(current);
514 cg_proto = sk->sk_prot->proto_cgroup(memcg);
515 if (!mem_cgroup_is_root(memcg) &&
516 memcg_proto_active(cg_proto) && css_tryget(&memcg->css)) {
517 sk->sk_cgrp = cg_proto;
522 EXPORT_SYMBOL(sock_update_memcg);
524 void sock_release_memcg(struct sock *sk)
526 if (mem_cgroup_sockets_enabled && sk->sk_cgrp) {
527 struct mem_cgroup *memcg;
528 WARN_ON(!sk->sk_cgrp->memcg);
529 memcg = sk->sk_cgrp->memcg;
530 css_put(&sk->sk_cgrp->memcg->css);
534 struct cg_proto *tcp_proto_cgroup(struct mem_cgroup *memcg)
536 if (!memcg || mem_cgroup_is_root(memcg))
539 return &memcg->tcp_mem.cg_proto;
541 EXPORT_SYMBOL(tcp_proto_cgroup);
543 static void disarm_sock_keys(struct mem_cgroup *memcg)
545 if (!memcg_proto_activated(&memcg->tcp_mem.cg_proto))
547 static_key_slow_dec(&memcg_socket_limit_enabled);
550 static void disarm_sock_keys(struct mem_cgroup *memcg)
555 #ifdef CONFIG_MEMCG_KMEM
557 * This will be the memcg's index in each cache's ->memcg_params->memcg_caches.
558 * There are two main reasons for not using the css_id for this:
559 * 1) this works better in sparse environments, where we have a lot of memcgs,
560 * but only a few kmem-limited. Or also, if we have, for instance, 200
561 * memcgs, and none but the 200th is kmem-limited, we'd have to have a
562 * 200 entry array for that.
564 * 2) In order not to violate the cgroup API, we would like to do all memory
565 * allocation in ->create(). At that point, we haven't yet allocated the
566 * css_id. Having a separate index prevents us from messing with the cgroup
569 * The current size of the caches array is stored in
570 * memcg_limited_groups_array_size. It will double each time we have to
573 static DEFINE_IDA(kmem_limited_groups);
574 int memcg_limited_groups_array_size;
577 * MIN_SIZE is different than 1, because we would like to avoid going through
578 * the alloc/free process all the time. In a small machine, 4 kmem-limited
579 * cgroups is a reasonable guess. In the future, it could be a parameter or
580 * tunable, but that is strictly not necessary.
582 * MAX_SIZE should be as large as the number of css_ids. Ideally, we could get
583 * this constant directly from cgroup, but it is understandable that this is
584 * better kept as an internal representation in cgroup.c. In any case, the
585 * css_id space is not getting any smaller, and we don't have to necessarily
586 * increase ours as well if it increases.
588 #define MEMCG_CACHES_MIN_SIZE 4
589 #define MEMCG_CACHES_MAX_SIZE 65535
592 * A lot of the calls to the cache allocation functions are expected to be
593 * inlined by the compiler. Since the calls to memcg_kmem_get_cache are
594 * conditional to this static branch, we'll have to allow modules that does
595 * kmem_cache_alloc and the such to see this symbol as well
597 struct static_key memcg_kmem_enabled_key;
598 EXPORT_SYMBOL(memcg_kmem_enabled_key);
600 static void disarm_kmem_keys(struct mem_cgroup *memcg)
602 if (memcg_kmem_is_active(memcg)) {
603 static_key_slow_dec(&memcg_kmem_enabled_key);
604 ida_simple_remove(&kmem_limited_groups, memcg->kmemcg_id);
607 * This check can't live in kmem destruction function,
608 * since the charges will outlive the cgroup
610 WARN_ON(res_counter_read_u64(&memcg->kmem, RES_USAGE) != 0);
613 static void disarm_kmem_keys(struct mem_cgroup *memcg)
616 #endif /* CONFIG_MEMCG_KMEM */
618 static void disarm_static_keys(struct mem_cgroup *memcg)
620 disarm_sock_keys(memcg);
621 disarm_kmem_keys(memcg);
624 static void drain_all_stock_async(struct mem_cgroup *memcg);
626 static struct mem_cgroup_per_zone *
627 mem_cgroup_zoneinfo(struct mem_cgroup *memcg, int nid, int zid)
629 VM_BUG_ON((unsigned)nid >= nr_node_ids);
630 return &memcg->nodeinfo[nid]->zoneinfo[zid];
633 struct cgroup_subsys_state *mem_cgroup_css(struct mem_cgroup *memcg)
638 static struct mem_cgroup_per_zone *
639 page_cgroup_zoneinfo(struct mem_cgroup *memcg, struct page *page)
641 int nid = page_to_nid(page);
642 int zid = page_zonenum(page);
644 return mem_cgroup_zoneinfo(memcg, nid, zid);
648 * Implementation Note: reading percpu statistics for memcg.
650 * Both of vmstat[] and percpu_counter has threshold and do periodic
651 * synchronization to implement "quick" read. There are trade-off between
652 * reading cost and precision of value. Then, we may have a chance to implement
653 * a periodic synchronizion of counter in memcg's counter.
655 * But this _read() function is used for user interface now. The user accounts
656 * memory usage by memory cgroup and he _always_ requires exact value because
657 * he accounts memory. Even if we provide quick-and-fuzzy read, we always
658 * have to visit all online cpus and make sum. So, for now, unnecessary
659 * synchronization is not implemented. (just implemented for cpu hotplug)
661 * If there are kernel internal actions which can make use of some not-exact
662 * value, and reading all cpu value can be performance bottleneck in some
663 * common workload, threashold and synchonization as vmstat[] should be
666 static long mem_cgroup_read_stat(struct mem_cgroup *memcg,
667 enum mem_cgroup_stat_index idx)
673 for_each_online_cpu(cpu)
674 val += per_cpu(memcg->stat->count[idx], cpu);
675 #ifdef CONFIG_HOTPLUG_CPU
676 spin_lock(&memcg->pcp_counter_lock);
677 val += memcg->nocpu_base.count[idx];
678 spin_unlock(&memcg->pcp_counter_lock);
684 static void mem_cgroup_swap_statistics(struct mem_cgroup *memcg,
687 int val = (charge) ? 1 : -1;
688 this_cpu_add(memcg->stat->count[MEM_CGROUP_STAT_SWAP], val);
691 static unsigned long mem_cgroup_read_events(struct mem_cgroup *memcg,
692 enum mem_cgroup_events_index idx)
694 unsigned long val = 0;
697 for_each_online_cpu(cpu)
698 val += per_cpu(memcg->stat->events[idx], cpu);
699 #ifdef CONFIG_HOTPLUG_CPU
700 spin_lock(&memcg->pcp_counter_lock);
701 val += memcg->nocpu_base.events[idx];
702 spin_unlock(&memcg->pcp_counter_lock);
707 static void mem_cgroup_charge_statistics(struct mem_cgroup *memcg,
709 bool anon, int nr_pages)
714 * Here, RSS means 'mapped anon' and anon's SwapCache. Shmem/tmpfs is
715 * counted as CACHE even if it's on ANON LRU.
718 __this_cpu_add(memcg->stat->count[MEM_CGROUP_STAT_RSS],
721 __this_cpu_add(memcg->stat->count[MEM_CGROUP_STAT_CACHE],
724 if (PageTransHuge(page))
725 __this_cpu_add(memcg->stat->count[MEM_CGROUP_STAT_RSS_HUGE],
728 /* pagein of a big page is an event. So, ignore page size */
730 __this_cpu_inc(memcg->stat->events[MEM_CGROUP_EVENTS_PGPGIN]);
732 __this_cpu_inc(memcg->stat->events[MEM_CGROUP_EVENTS_PGPGOUT]);
733 nr_pages = -nr_pages; /* for event */
736 __this_cpu_add(memcg->stat->nr_page_events, nr_pages);
742 mem_cgroup_get_lru_size(struct lruvec *lruvec, enum lru_list lru)
744 struct mem_cgroup_per_zone *mz;
746 mz = container_of(lruvec, struct mem_cgroup_per_zone, lruvec);
747 return mz->lru_size[lru];
751 mem_cgroup_zone_nr_lru_pages(struct mem_cgroup *memcg, int nid, int zid,
752 unsigned int lru_mask)
754 struct mem_cgroup_per_zone *mz;
756 unsigned long ret = 0;
758 mz = mem_cgroup_zoneinfo(memcg, nid, zid);
761 if (BIT(lru) & lru_mask)
762 ret += mz->lru_size[lru];
768 mem_cgroup_node_nr_lru_pages(struct mem_cgroup *memcg,
769 int nid, unsigned int lru_mask)
774 for (zid = 0; zid < MAX_NR_ZONES; zid++)
775 total += mem_cgroup_zone_nr_lru_pages(memcg,
781 static unsigned long mem_cgroup_nr_lru_pages(struct mem_cgroup *memcg,
782 unsigned int lru_mask)
787 for_each_node_state(nid, N_MEMORY)
788 total += mem_cgroup_node_nr_lru_pages(memcg, nid, lru_mask);
792 static bool mem_cgroup_event_ratelimit(struct mem_cgroup *memcg,
793 enum mem_cgroup_events_target target)
795 unsigned long val, next;
797 val = __this_cpu_read(memcg->stat->nr_page_events);
798 next = __this_cpu_read(memcg->stat->targets[target]);
799 /* from time_after() in jiffies.h */
800 if ((long)next - (long)val < 0) {
802 case MEM_CGROUP_TARGET_THRESH:
803 next = val + THRESHOLDS_EVENTS_TARGET;
805 case MEM_CGROUP_TARGET_NUMAINFO:
806 next = val + NUMAINFO_EVENTS_TARGET;
811 __this_cpu_write(memcg->stat->targets[target], next);
818 * Check events in order.
821 static void memcg_check_events(struct mem_cgroup *memcg, struct page *page)
824 /* threshold event is triggered in finer grain than soft limit */
825 if (unlikely(mem_cgroup_event_ratelimit(memcg,
826 MEM_CGROUP_TARGET_THRESH))) {
827 bool do_numainfo __maybe_unused;
830 do_numainfo = mem_cgroup_event_ratelimit(memcg,
831 MEM_CGROUP_TARGET_NUMAINFO);
835 mem_cgroup_threshold(memcg);
837 if (unlikely(do_numainfo))
838 atomic_inc(&memcg->numainfo_events);
844 struct mem_cgroup *mem_cgroup_from_task(struct task_struct *p)
847 * mm_update_next_owner() may clear mm->owner to NULL
848 * if it races with swapoff, page migration, etc.
849 * So this can be called with p == NULL.
854 return mem_cgroup_from_css(task_css(p, mem_cgroup_subsys_id));
857 struct mem_cgroup *try_get_mem_cgroup_from_mm(struct mm_struct *mm)
859 struct mem_cgroup *memcg = NULL;
864 * Because we have no locks, mm->owner's may be being moved to other
865 * cgroup. We use css_tryget() here even if this looks
866 * pessimistic (rather than adding locks here).
870 memcg = mem_cgroup_from_task(rcu_dereference(mm->owner));
871 if (unlikely(!memcg))
873 } while (!css_tryget(&memcg->css));
878 static enum mem_cgroup_filter_t
879 mem_cgroup_filter(struct mem_cgroup *memcg, struct mem_cgroup *root,
880 mem_cgroup_iter_filter cond)
884 return cond(memcg, root);
888 * Returns a next (in a pre-order walk) alive memcg (with elevated css
889 * ref. count) or NULL if the whole root's subtree has been visited.
891 * helper function to be used by mem_cgroup_iter
893 static struct mem_cgroup *__mem_cgroup_iter_next(struct mem_cgroup *root,
894 struct mem_cgroup *last_visited, mem_cgroup_iter_filter cond)
896 struct cgroup_subsys_state *prev_css, *next_css;
898 prev_css = last_visited ? &last_visited->css : NULL;
900 next_css = css_next_descendant_pre(prev_css, &root->css);
903 * Even if we found a group we have to make sure it is
904 * alive. css && !memcg means that the groups should be
905 * skipped and we should continue the tree walk.
906 * last_visited css is safe to use because it is
907 * protected by css_get and the tree walk is rcu safe.
910 struct mem_cgroup *mem = mem_cgroup_from_css(next_css);
912 switch (mem_cgroup_filter(mem, root, cond)) {
920 * css_rightmost_descendant is not an optimal way to
921 * skip through a subtree (especially for imbalanced
922 * trees leaning to right) but that's what we have right
923 * now. More effective solution would be traversing
924 * right-up for first non-NULL without calling
925 * css_next_descendant_pre afterwards.
927 prev_css = css_rightmost_descendant(next_css);
930 if (css_tryget(&mem->css))
943 static void mem_cgroup_iter_invalidate(struct mem_cgroup *root)
946 * When a group in the hierarchy below root is destroyed, the
947 * hierarchy iterator can no longer be trusted since it might
948 * have pointed to the destroyed group. Invalidate it.
950 atomic_inc(&root->dead_count);
953 static struct mem_cgroup *
954 mem_cgroup_iter_load(struct mem_cgroup_reclaim_iter *iter,
955 struct mem_cgroup *root,
958 struct mem_cgroup *position = NULL;
960 * A cgroup destruction happens in two stages: offlining and
961 * release. They are separated by a RCU grace period.
963 * If the iterator is valid, we may still race with an
964 * offlining. The RCU lock ensures the object won't be
965 * released, tryget will fail if we lost the race.
967 *sequence = atomic_read(&root->dead_count);
968 if (iter->last_dead_count == *sequence) {
970 position = iter->last_visited;
971 if (position && !css_tryget(&position->css))
977 static void mem_cgroup_iter_update(struct mem_cgroup_reclaim_iter *iter,
978 struct mem_cgroup *last_visited,
979 struct mem_cgroup *new_position,
983 css_put(&last_visited->css);
985 * We store the sequence count from the time @last_visited was
986 * loaded successfully instead of rereading it here so that we
987 * don't lose destruction events in between. We could have
988 * raced with the destruction of @new_position after all.
990 iter->last_visited = new_position;
992 iter->last_dead_count = sequence;
996 * mem_cgroup_iter - iterate over memory cgroup hierarchy
997 * @root: hierarchy root
998 * @prev: previously returned memcg, NULL on first invocation
999 * @reclaim: cookie for shared reclaim walks, NULL for full walks
1000 * @cond: filter for visited nodes, NULL for no filter
1002 * Returns references to children of the hierarchy below @root, or
1003 * @root itself, or %NULL after a full round-trip.
1005 * Caller must pass the return value in @prev on subsequent
1006 * invocations for reference counting, or use mem_cgroup_iter_break()
1007 * to cancel a hierarchy walk before the round-trip is complete.
1009 * Reclaimers can specify a zone and a priority level in @reclaim to
1010 * divide up the memcgs in the hierarchy among all concurrent
1011 * reclaimers operating on the same zone and priority.
1013 struct mem_cgroup *mem_cgroup_iter_cond(struct mem_cgroup *root,
1014 struct mem_cgroup *prev,
1015 struct mem_cgroup_reclaim_cookie *reclaim,
1016 mem_cgroup_iter_filter cond)
1018 struct mem_cgroup *memcg = NULL;
1019 struct mem_cgroup *last_visited = NULL;
1021 if (mem_cgroup_disabled()) {
1022 /* first call must return non-NULL, second return NULL */
1023 return (struct mem_cgroup *)(unsigned long)!prev;
1027 root = root_mem_cgroup;
1029 if (prev && !reclaim)
1030 last_visited = prev;
1032 if (!root->use_hierarchy && root != root_mem_cgroup) {
1035 if (mem_cgroup_filter(root, root, cond) == VISIT)
1042 struct mem_cgroup_reclaim_iter *uninitialized_var(iter);
1043 int uninitialized_var(seq);
1046 int nid = zone_to_nid(reclaim->zone);
1047 int zid = zone_idx(reclaim->zone);
1048 struct mem_cgroup_per_zone *mz;
1050 mz = mem_cgroup_zoneinfo(root, nid, zid);
1051 iter = &mz->reclaim_iter[reclaim->priority];
1052 if (prev && reclaim->generation != iter->generation) {
1053 iter->last_visited = NULL;
1057 last_visited = mem_cgroup_iter_load(iter, root, &seq);
1060 memcg = __mem_cgroup_iter_next(root, last_visited, cond);
1063 mem_cgroup_iter_update(iter, last_visited, memcg, seq);
1067 else if (!prev && memcg)
1068 reclaim->generation = iter->generation;
1072 * We have finished the whole tree walk or no group has been
1073 * visited because filter told us to skip the root node.
1075 if (!memcg && (prev || (cond && !last_visited)))
1081 if (prev && prev != root)
1082 css_put(&prev->css);
1088 * mem_cgroup_iter_break - abort a hierarchy walk prematurely
1089 * @root: hierarchy root
1090 * @prev: last visited hierarchy member as returned by mem_cgroup_iter()
1092 void mem_cgroup_iter_break(struct mem_cgroup *root,
1093 struct mem_cgroup *prev)
1096 root = root_mem_cgroup;
1097 if (prev && prev != root)
1098 css_put(&prev->css);
1102 * Iteration constructs for visiting all cgroups (under a tree). If
1103 * loops are exited prematurely (break), mem_cgroup_iter_break() must
1104 * be used for reference counting.
1106 #define for_each_mem_cgroup_tree(iter, root) \
1107 for (iter = mem_cgroup_iter(root, NULL, NULL); \
1109 iter = mem_cgroup_iter(root, iter, NULL))
1111 #define for_each_mem_cgroup(iter) \
1112 for (iter = mem_cgroup_iter(NULL, NULL, NULL); \
1114 iter = mem_cgroup_iter(NULL, iter, NULL))
1116 void __mem_cgroup_count_vm_event(struct mm_struct *mm, enum vm_event_item idx)
1118 struct mem_cgroup *memcg;
1121 memcg = mem_cgroup_from_task(rcu_dereference(mm->owner));
1122 if (unlikely(!memcg))
1127 this_cpu_inc(memcg->stat->events[MEM_CGROUP_EVENTS_PGFAULT]);
1130 this_cpu_inc(memcg->stat->events[MEM_CGROUP_EVENTS_PGMAJFAULT]);
1138 EXPORT_SYMBOL(__mem_cgroup_count_vm_event);
1141 * mem_cgroup_zone_lruvec - get the lru list vector for a zone and memcg
1142 * @zone: zone of the wanted lruvec
1143 * @memcg: memcg of the wanted lruvec
1145 * Returns the lru list vector holding pages for the given @zone and
1146 * @mem. This can be the global zone lruvec, if the memory controller
1149 struct lruvec *mem_cgroup_zone_lruvec(struct zone *zone,
1150 struct mem_cgroup *memcg)
1152 struct mem_cgroup_per_zone *mz;
1153 struct lruvec *lruvec;
1155 if (mem_cgroup_disabled()) {
1156 lruvec = &zone->lruvec;
1160 mz = mem_cgroup_zoneinfo(memcg, zone_to_nid(zone), zone_idx(zone));
1161 lruvec = &mz->lruvec;
1164 * Since a node can be onlined after the mem_cgroup was created,
1165 * we have to be prepared to initialize lruvec->zone here;
1166 * and if offlined then reonlined, we need to reinitialize it.
1168 if (unlikely(lruvec->zone != zone))
1169 lruvec->zone = zone;
1174 * Following LRU functions are allowed to be used without PCG_LOCK.
1175 * Operations are called by routine of global LRU independently from memcg.
1176 * What we have to take care of here is validness of pc->mem_cgroup.
1178 * Changes to pc->mem_cgroup happens when
1181 * In typical case, "charge" is done before add-to-lru. Exception is SwapCache.
1182 * It is added to LRU before charge.
1183 * If PCG_USED bit is not set, page_cgroup is not added to this private LRU.
1184 * When moving account, the page is not on LRU. It's isolated.
1188 * mem_cgroup_page_lruvec - return lruvec for adding an lru page
1190 * @zone: zone of the page
1192 struct lruvec *mem_cgroup_page_lruvec(struct page *page, struct zone *zone)
1194 struct mem_cgroup_per_zone *mz;
1195 struct mem_cgroup *memcg;
1196 struct page_cgroup *pc;
1197 struct lruvec *lruvec;
1199 if (mem_cgroup_disabled()) {
1200 lruvec = &zone->lruvec;
1204 pc = lookup_page_cgroup(page);
1205 memcg = pc->mem_cgroup;
1208 * Surreptitiously switch any uncharged offlist page to root:
1209 * an uncharged page off lru does nothing to secure
1210 * its former mem_cgroup from sudden removal.
1212 * Our caller holds lru_lock, and PageCgroupUsed is updated
1213 * under page_cgroup lock: between them, they make all uses
1214 * of pc->mem_cgroup safe.
1216 if (!PageLRU(page) && !PageCgroupUsed(pc) && memcg != root_mem_cgroup)
1217 pc->mem_cgroup = memcg = root_mem_cgroup;
1219 mz = page_cgroup_zoneinfo(memcg, page);
1220 lruvec = &mz->lruvec;
1223 * Since a node can be onlined after the mem_cgroup was created,
1224 * we have to be prepared to initialize lruvec->zone here;
1225 * and if offlined then reonlined, we need to reinitialize it.
1227 if (unlikely(lruvec->zone != zone))
1228 lruvec->zone = zone;
1233 * mem_cgroup_update_lru_size - account for adding or removing an lru page
1234 * @lruvec: mem_cgroup per zone lru vector
1235 * @lru: index of lru list the page is sitting on
1236 * @nr_pages: positive when adding or negative when removing
1238 * This function must be called when a page is added to or removed from an
1241 void mem_cgroup_update_lru_size(struct lruvec *lruvec, enum lru_list lru,
1244 struct mem_cgroup_per_zone *mz;
1245 unsigned long *lru_size;
1247 if (mem_cgroup_disabled())
1250 mz = container_of(lruvec, struct mem_cgroup_per_zone, lruvec);
1251 lru_size = mz->lru_size + lru;
1252 *lru_size += nr_pages;
1253 VM_BUG_ON((long)(*lru_size) < 0);
1257 * Checks whether given mem is same or in the root_mem_cgroup's
1260 bool __mem_cgroup_same_or_subtree(const struct mem_cgroup *root_memcg,
1261 struct mem_cgroup *memcg)
1263 if (root_memcg == memcg)
1265 if (!root_memcg->use_hierarchy || !memcg)
1267 return css_is_ancestor(&memcg->css, &root_memcg->css);
1270 static bool mem_cgroup_same_or_subtree(const struct mem_cgroup *root_memcg,
1271 struct mem_cgroup *memcg)
1276 ret = __mem_cgroup_same_or_subtree(root_memcg, memcg);
1281 bool task_in_mem_cgroup(struct task_struct *task,
1282 const struct mem_cgroup *memcg)
1284 struct mem_cgroup *curr = NULL;
1285 struct task_struct *p;
1288 p = find_lock_task_mm(task);
1290 curr = try_get_mem_cgroup_from_mm(p->mm);
1294 * All threads may have already detached their mm's, but the oom
1295 * killer still needs to detect if they have already been oom
1296 * killed to prevent needlessly killing additional tasks.
1299 curr = mem_cgroup_from_task(task);
1301 css_get(&curr->css);
1307 * We should check use_hierarchy of "memcg" not "curr". Because checking
1308 * use_hierarchy of "curr" here make this function true if hierarchy is
1309 * enabled in "curr" and "curr" is a child of "memcg" in *cgroup*
1310 * hierarchy(even if use_hierarchy is disabled in "memcg").
1312 ret = mem_cgroup_same_or_subtree(memcg, curr);
1313 css_put(&curr->css);
1317 int mem_cgroup_inactive_anon_is_low(struct lruvec *lruvec)
1319 unsigned long inactive_ratio;
1320 unsigned long inactive;
1321 unsigned long active;
1324 inactive = mem_cgroup_get_lru_size(lruvec, LRU_INACTIVE_ANON);
1325 active = mem_cgroup_get_lru_size(lruvec, LRU_ACTIVE_ANON);
1327 gb = (inactive + active) >> (30 - PAGE_SHIFT);
1329 inactive_ratio = int_sqrt(10 * gb);
1333 return inactive * inactive_ratio < active;
1336 #define mem_cgroup_from_res_counter(counter, member) \
1337 container_of(counter, struct mem_cgroup, member)
1340 * mem_cgroup_margin - calculate chargeable space of a memory cgroup
1341 * @memcg: the memory cgroup
1343 * Returns the maximum amount of memory @mem can be charged with, in
1346 static unsigned long mem_cgroup_margin(struct mem_cgroup *memcg)
1348 unsigned long long margin;
1350 margin = res_counter_margin(&memcg->res);
1351 if (do_swap_account)
1352 margin = min(margin, res_counter_margin(&memcg->memsw));
1353 return margin >> PAGE_SHIFT;
1356 int mem_cgroup_swappiness(struct mem_cgroup *memcg)
1359 if (!css_parent(&memcg->css))
1360 return vm_swappiness;
1362 return memcg->swappiness;
1366 * memcg->moving_account is used for checking possibility that some thread is
1367 * calling move_account(). When a thread on CPU-A starts moving pages under
1368 * a memcg, other threads should check memcg->moving_account under
1369 * rcu_read_lock(), like this:
1373 * memcg->moving_account+1 if (memcg->mocing_account)
1375 * synchronize_rcu() update something.
1380 /* for quick checking without looking up memcg */
1381 atomic_t memcg_moving __read_mostly;
1383 static void mem_cgroup_start_move(struct mem_cgroup *memcg)
1385 atomic_inc(&memcg_moving);
1386 atomic_inc(&memcg->moving_account);
1390 static void mem_cgroup_end_move(struct mem_cgroup *memcg)
1393 * Now, mem_cgroup_clear_mc() may call this function with NULL.
1394 * We check NULL in callee rather than caller.
1397 atomic_dec(&memcg_moving);
1398 atomic_dec(&memcg->moving_account);
1403 * 2 routines for checking "mem" is under move_account() or not.
1405 * mem_cgroup_stolen() - checking whether a cgroup is mc.from or not. This
1406 * is used for avoiding races in accounting. If true,
1407 * pc->mem_cgroup may be overwritten.
1409 * mem_cgroup_under_move() - checking a cgroup is mc.from or mc.to or
1410 * under hierarchy of moving cgroups. This is for
1411 * waiting at hith-memory prressure caused by "move".
1414 static bool mem_cgroup_stolen(struct mem_cgroup *memcg)
1416 VM_BUG_ON(!rcu_read_lock_held());
1417 return atomic_read(&memcg->moving_account) > 0;
1420 static bool mem_cgroup_under_move(struct mem_cgroup *memcg)
1422 struct mem_cgroup *from;
1423 struct mem_cgroup *to;
1426 * Unlike task_move routines, we access mc.to, mc.from not under
1427 * mutual exclusion by cgroup_mutex. Here, we take spinlock instead.
1429 spin_lock(&mc.lock);
1435 ret = mem_cgroup_same_or_subtree(memcg, from)
1436 || mem_cgroup_same_or_subtree(memcg, to);
1438 spin_unlock(&mc.lock);
1442 static bool mem_cgroup_wait_acct_move(struct mem_cgroup *memcg)
1444 if (mc.moving_task && current != mc.moving_task) {
1445 if (mem_cgroup_under_move(memcg)) {
1447 prepare_to_wait(&mc.waitq, &wait, TASK_INTERRUPTIBLE);
1448 /* moving charge context might have finished. */
1451 finish_wait(&mc.waitq, &wait);
1459 * Take this lock when
1460 * - a code tries to modify page's memcg while it's USED.
1461 * - a code tries to modify page state accounting in a memcg.
1462 * see mem_cgroup_stolen(), too.
1464 static void move_lock_mem_cgroup(struct mem_cgroup *memcg,
1465 unsigned long *flags)
1467 spin_lock_irqsave(&memcg->move_lock, *flags);
1470 static void move_unlock_mem_cgroup(struct mem_cgroup *memcg,
1471 unsigned long *flags)
1473 spin_unlock_irqrestore(&memcg->move_lock, *flags);
1476 #define K(x) ((x) << (PAGE_SHIFT-10))
1478 * mem_cgroup_print_oom_info: Print OOM information relevant to memory controller.
1479 * @memcg: The memory cgroup that went over limit
1480 * @p: Task that is going to be killed
1482 * NOTE: @memcg and @p's mem_cgroup can be different when hierarchy is
1485 void mem_cgroup_print_oom_info(struct mem_cgroup *memcg, struct task_struct *p)
1487 struct cgroup *task_cgrp;
1488 struct cgroup *mem_cgrp;
1490 * Need a buffer in BSS, can't rely on allocations. The code relies
1491 * on the assumption that OOM is serialized for memory controller.
1492 * If this assumption is broken, revisit this code.
1494 static char memcg_name[PATH_MAX];
1496 struct mem_cgroup *iter;
1504 mem_cgrp = memcg->css.cgroup;
1505 task_cgrp = task_cgroup(p, mem_cgroup_subsys_id);
1507 ret = cgroup_path(task_cgrp, memcg_name, PATH_MAX);
1510 * Unfortunately, we are unable to convert to a useful name
1511 * But we'll still print out the usage information
1518 pr_info("Task in %s killed", memcg_name);
1521 ret = cgroup_path(mem_cgrp, memcg_name, PATH_MAX);
1529 * Continues from above, so we don't need an KERN_ level
1531 pr_cont(" as a result of limit of %s\n", memcg_name);
1534 pr_info("memory: usage %llukB, limit %llukB, failcnt %llu\n",
1535 res_counter_read_u64(&memcg->res, RES_USAGE) >> 10,
1536 res_counter_read_u64(&memcg->res, RES_LIMIT) >> 10,
1537 res_counter_read_u64(&memcg->res, RES_FAILCNT));
1538 pr_info("memory+swap: usage %llukB, limit %llukB, failcnt %llu\n",
1539 res_counter_read_u64(&memcg->memsw, RES_USAGE) >> 10,
1540 res_counter_read_u64(&memcg->memsw, RES_LIMIT) >> 10,
1541 res_counter_read_u64(&memcg->memsw, RES_FAILCNT));
1542 pr_info("kmem: usage %llukB, limit %llukB, failcnt %llu\n",
1543 res_counter_read_u64(&memcg->kmem, RES_USAGE) >> 10,
1544 res_counter_read_u64(&memcg->kmem, RES_LIMIT) >> 10,
1545 res_counter_read_u64(&memcg->kmem, RES_FAILCNT));
1547 for_each_mem_cgroup_tree(iter, memcg) {
1548 pr_info("Memory cgroup stats");
1551 ret = cgroup_path(iter->css.cgroup, memcg_name, PATH_MAX);
1553 pr_cont(" for %s", memcg_name);
1557 for (i = 0; i < MEM_CGROUP_STAT_NSTATS; i++) {
1558 if (i == MEM_CGROUP_STAT_SWAP && !do_swap_account)
1560 pr_cont(" %s:%ldKB", mem_cgroup_stat_names[i],
1561 K(mem_cgroup_read_stat(iter, i)));
1564 for (i = 0; i < NR_LRU_LISTS; i++)
1565 pr_cont(" %s:%luKB", mem_cgroup_lru_names[i],
1566 K(mem_cgroup_nr_lru_pages(iter, BIT(i))));
1573 * This function returns the number of memcg under hierarchy tree. Returns
1574 * 1(self count) if no children.
1576 static int mem_cgroup_count_children(struct mem_cgroup *memcg)
1579 struct mem_cgroup *iter;
1581 for_each_mem_cgroup_tree(iter, memcg)
1587 * Return the memory (and swap, if configured) limit for a memcg.
1589 static u64 mem_cgroup_get_limit(struct mem_cgroup *memcg)
1593 limit = res_counter_read_u64(&memcg->res, RES_LIMIT);
1596 * Do not consider swap space if we cannot swap due to swappiness
1598 if (mem_cgroup_swappiness(memcg)) {
1601 limit += total_swap_pages << PAGE_SHIFT;
1602 memsw = res_counter_read_u64(&memcg->memsw, RES_LIMIT);
1605 * If memsw is finite and limits the amount of swap space
1606 * available to this memcg, return that limit.
1608 limit = min(limit, memsw);
1614 static void mem_cgroup_out_of_memory(struct mem_cgroup *memcg, gfp_t gfp_mask,
1617 struct mem_cgroup *iter;
1618 unsigned long chosen_points = 0;
1619 unsigned long totalpages;
1620 unsigned int points = 0;
1621 struct task_struct *chosen = NULL;
1624 * If current has a pending SIGKILL or is exiting, then automatically
1625 * select it. The goal is to allow it to allocate so that it may
1626 * quickly exit and free its memory.
1628 if (fatal_signal_pending(current) || current->flags & PF_EXITING) {
1629 set_thread_flag(TIF_MEMDIE);
1633 check_panic_on_oom(CONSTRAINT_MEMCG, gfp_mask, order, NULL);
1634 totalpages = mem_cgroup_get_limit(memcg) >> PAGE_SHIFT ? : 1;
1635 for_each_mem_cgroup_tree(iter, memcg) {
1636 struct css_task_iter it;
1637 struct task_struct *task;
1639 css_task_iter_start(&iter->css, &it);
1640 while ((task = css_task_iter_next(&it))) {
1641 switch (oom_scan_process_thread(task, totalpages, NULL,
1643 case OOM_SCAN_SELECT:
1645 put_task_struct(chosen);
1647 chosen_points = ULONG_MAX;
1648 get_task_struct(chosen);
1650 case OOM_SCAN_CONTINUE:
1652 case OOM_SCAN_ABORT:
1653 css_task_iter_end(&it);
1654 mem_cgroup_iter_break(memcg, iter);
1656 put_task_struct(chosen);
1661 points = oom_badness(task, memcg, NULL, totalpages);
1662 if (points > chosen_points) {
1664 put_task_struct(chosen);
1666 chosen_points = points;
1667 get_task_struct(chosen);
1670 css_task_iter_end(&it);
1675 points = chosen_points * 1000 / totalpages;
1676 oom_kill_process(chosen, gfp_mask, order, points, totalpages, memcg,
1677 NULL, "Memory cgroup out of memory");
1680 static unsigned long mem_cgroup_reclaim(struct mem_cgroup *memcg,
1682 unsigned long flags)
1684 unsigned long total = 0;
1685 bool noswap = false;
1688 if (flags & MEM_CGROUP_RECLAIM_NOSWAP)
1690 if (!(flags & MEM_CGROUP_RECLAIM_SHRINK) && memcg->memsw_is_minimum)
1693 for (loop = 0; loop < MEM_CGROUP_MAX_RECLAIM_LOOPS; loop++) {
1695 drain_all_stock_async(memcg);
1696 total += try_to_free_mem_cgroup_pages(memcg, gfp_mask, noswap);
1698 * Allow limit shrinkers, which are triggered directly
1699 * by userspace, to catch signals and stop reclaim
1700 * after minimal progress, regardless of the margin.
1702 if (total && (flags & MEM_CGROUP_RECLAIM_SHRINK))
1704 if (mem_cgroup_margin(memcg))
1707 * If nothing was reclaimed after two attempts, there
1708 * may be no reclaimable pages in this hierarchy.
1716 #if MAX_NUMNODES > 1
1718 * test_mem_cgroup_node_reclaimable
1719 * @memcg: the target memcg
1720 * @nid: the node ID to be checked.
1721 * @noswap : specify true here if the user wants flle only information.
1723 * This function returns whether the specified memcg contains any
1724 * reclaimable pages on a node. Returns true if there are any reclaimable
1725 * pages in the node.
1727 static bool test_mem_cgroup_node_reclaimable(struct mem_cgroup *memcg,
1728 int nid, bool noswap)
1730 if (mem_cgroup_node_nr_lru_pages(memcg, nid, LRU_ALL_FILE))
1732 if (noswap || !total_swap_pages)
1734 if (mem_cgroup_node_nr_lru_pages(memcg, nid, LRU_ALL_ANON))
1741 * Always updating the nodemask is not very good - even if we have an empty
1742 * list or the wrong list here, we can start from some node and traverse all
1743 * nodes based on the zonelist. So update the list loosely once per 10 secs.
1746 static void mem_cgroup_may_update_nodemask(struct mem_cgroup *memcg)
1750 * numainfo_events > 0 means there was at least NUMAINFO_EVENTS_TARGET
1751 * pagein/pageout changes since the last update.
1753 if (!atomic_read(&memcg->numainfo_events))
1755 if (atomic_inc_return(&memcg->numainfo_updating) > 1)
1758 /* make a nodemask where this memcg uses memory from */
1759 memcg->scan_nodes = node_states[N_MEMORY];
1761 for_each_node_mask(nid, node_states[N_MEMORY]) {
1763 if (!test_mem_cgroup_node_reclaimable(memcg, nid, false))
1764 node_clear(nid, memcg->scan_nodes);
1767 atomic_set(&memcg->numainfo_events, 0);
1768 atomic_set(&memcg->numainfo_updating, 0);
1772 * Selecting a node where we start reclaim from. Because what we need is just
1773 * reducing usage counter, start from anywhere is O,K. Considering
1774 * memory reclaim from current node, there are pros. and cons.
1776 * Freeing memory from current node means freeing memory from a node which
1777 * we'll use or we've used. So, it may make LRU bad. And if several threads
1778 * hit limits, it will see a contention on a node. But freeing from remote
1779 * node means more costs for memory reclaim because of memory latency.
1781 * Now, we use round-robin. Better algorithm is welcomed.
1783 int mem_cgroup_select_victim_node(struct mem_cgroup *memcg)
1787 mem_cgroup_may_update_nodemask(memcg);
1788 node = memcg->last_scanned_node;
1790 node = next_node(node, memcg->scan_nodes);
1791 if (node == MAX_NUMNODES)
1792 node = first_node(memcg->scan_nodes);
1794 * We call this when we hit limit, not when pages are added to LRU.
1795 * No LRU may hold pages because all pages are UNEVICTABLE or
1796 * memcg is too small and all pages are not on LRU. In that case,
1797 * we use curret node.
1799 if (unlikely(node == MAX_NUMNODES))
1800 node = numa_node_id();
1802 memcg->last_scanned_node = node;
1807 int mem_cgroup_select_victim_node(struct mem_cgroup *memcg)
1815 * A group is eligible for the soft limit reclaim under the given root
1817 * a) it is over its soft limit
1818 * b) any parent up the hierarchy is over its soft limit
1820 enum mem_cgroup_filter_t
1821 mem_cgroup_soft_reclaim_eligible(struct mem_cgroup *memcg,
1822 struct mem_cgroup *root)
1824 struct mem_cgroup *parent = memcg;
1826 if (res_counter_soft_limit_excess(&memcg->res))
1830 * If any parent up to the root in the hierarchy is over its soft limit
1831 * then we have to obey and reclaim from this group as well.
1833 while((parent = parent_mem_cgroup(parent))) {
1834 if (res_counter_soft_limit_excess(&parent->res))
1844 * Check OOM-Killer is already running under our hierarchy.
1845 * If someone is running, return false.
1846 * Has to be called with memcg_oom_lock
1848 static bool mem_cgroup_oom_lock(struct mem_cgroup *memcg)
1850 struct mem_cgroup *iter, *failed = NULL;
1852 for_each_mem_cgroup_tree(iter, memcg) {
1853 if (iter->oom_lock) {
1855 * this subtree of our hierarchy is already locked
1856 * so we cannot give a lock.
1859 mem_cgroup_iter_break(memcg, iter);
1862 iter->oom_lock = true;
1869 * OK, we failed to lock the whole subtree so we have to clean up
1870 * what we set up to the failing subtree
1872 for_each_mem_cgroup_tree(iter, memcg) {
1873 if (iter == failed) {
1874 mem_cgroup_iter_break(memcg, iter);
1877 iter->oom_lock = false;
1883 * Has to be called with memcg_oom_lock
1885 static int mem_cgroup_oom_unlock(struct mem_cgroup *memcg)
1887 struct mem_cgroup *iter;
1889 for_each_mem_cgroup_tree(iter, memcg)
1890 iter->oom_lock = false;
1894 static void mem_cgroup_mark_under_oom(struct mem_cgroup *memcg)
1896 struct mem_cgroup *iter;
1898 for_each_mem_cgroup_tree(iter, memcg)
1899 atomic_inc(&iter->under_oom);
1902 static void mem_cgroup_unmark_under_oom(struct mem_cgroup *memcg)
1904 struct mem_cgroup *iter;
1907 * When a new child is created while the hierarchy is under oom,
1908 * mem_cgroup_oom_lock() may not be called. We have to use
1909 * atomic_add_unless() here.
1911 for_each_mem_cgroup_tree(iter, memcg)
1912 atomic_add_unless(&iter->under_oom, -1, 0);
1915 static DEFINE_SPINLOCK(memcg_oom_lock);
1916 static DECLARE_WAIT_QUEUE_HEAD(memcg_oom_waitq);
1918 struct oom_wait_info {
1919 struct mem_cgroup *memcg;
1923 static int memcg_oom_wake_function(wait_queue_t *wait,
1924 unsigned mode, int sync, void *arg)
1926 struct mem_cgroup *wake_memcg = (struct mem_cgroup *)arg;
1927 struct mem_cgroup *oom_wait_memcg;
1928 struct oom_wait_info *oom_wait_info;
1930 oom_wait_info = container_of(wait, struct oom_wait_info, wait);
1931 oom_wait_memcg = oom_wait_info->memcg;
1934 * Both of oom_wait_info->memcg and wake_memcg are stable under us.
1935 * Then we can use css_is_ancestor without taking care of RCU.
1937 if (!mem_cgroup_same_or_subtree(oom_wait_memcg, wake_memcg)
1938 && !mem_cgroup_same_or_subtree(wake_memcg, oom_wait_memcg))
1940 return autoremove_wake_function(wait, mode, sync, arg);
1943 static void memcg_wakeup_oom(struct mem_cgroup *memcg)
1945 /* for filtering, pass "memcg" as argument. */
1946 __wake_up(&memcg_oom_waitq, TASK_NORMAL, 0, memcg);
1949 static void memcg_oom_recover(struct mem_cgroup *memcg)
1951 if (memcg && atomic_read(&memcg->under_oom))
1952 memcg_wakeup_oom(memcg);
1956 * try to call OOM killer. returns false if we should exit memory-reclaim loop.
1958 static bool mem_cgroup_handle_oom(struct mem_cgroup *memcg, gfp_t mask,
1961 struct oom_wait_info owait;
1962 bool locked, need_to_kill;
1964 owait.memcg = memcg;
1965 owait.wait.flags = 0;
1966 owait.wait.func = memcg_oom_wake_function;
1967 owait.wait.private = current;
1968 INIT_LIST_HEAD(&owait.wait.task_list);
1969 need_to_kill = true;
1970 mem_cgroup_mark_under_oom(memcg);
1972 /* At first, try to OOM lock hierarchy under memcg.*/
1973 spin_lock(&memcg_oom_lock);
1974 locked = mem_cgroup_oom_lock(memcg);
1976 * Even if signal_pending(), we can't quit charge() loop without
1977 * accounting. So, UNINTERRUPTIBLE is appropriate. But SIGKILL
1978 * under OOM is always welcomed, use TASK_KILLABLE here.
1980 prepare_to_wait(&memcg_oom_waitq, &owait.wait, TASK_KILLABLE);
1981 if (!locked || memcg->oom_kill_disable)
1982 need_to_kill = false;
1984 mem_cgroup_oom_notify(memcg);
1985 spin_unlock(&memcg_oom_lock);
1988 finish_wait(&memcg_oom_waitq, &owait.wait);
1989 mem_cgroup_out_of_memory(memcg, mask, order);
1992 finish_wait(&memcg_oom_waitq, &owait.wait);
1994 spin_lock(&memcg_oom_lock);
1996 mem_cgroup_oom_unlock(memcg);
1997 memcg_wakeup_oom(memcg);
1998 spin_unlock(&memcg_oom_lock);
2000 mem_cgroup_unmark_under_oom(memcg);
2002 if (test_thread_flag(TIF_MEMDIE) || fatal_signal_pending(current))
2004 /* Give chance to dying process */
2005 schedule_timeout_uninterruptible(1);
2010 * Currently used to update mapped file statistics, but the routine can be
2011 * generalized to update other statistics as well.
2013 * Notes: Race condition
2015 * We usually use page_cgroup_lock() for accessing page_cgroup member but
2016 * it tends to be costly. But considering some conditions, we doesn't need
2017 * to do so _always_.
2019 * Considering "charge", lock_page_cgroup() is not required because all
2020 * file-stat operations happen after a page is attached to radix-tree. There
2021 * are no race with "charge".
2023 * Considering "uncharge", we know that memcg doesn't clear pc->mem_cgroup
2024 * at "uncharge" intentionally. So, we always see valid pc->mem_cgroup even
2025 * if there are race with "uncharge". Statistics itself is properly handled
2028 * Considering "move", this is an only case we see a race. To make the race
2029 * small, we check mm->moving_account and detect there are possibility of race
2030 * If there is, we take a lock.
2033 void __mem_cgroup_begin_update_page_stat(struct page *page,
2034 bool *locked, unsigned long *flags)
2036 struct mem_cgroup *memcg;
2037 struct page_cgroup *pc;
2039 pc = lookup_page_cgroup(page);
2041 memcg = pc->mem_cgroup;
2042 if (unlikely(!memcg || !PageCgroupUsed(pc)))
2045 * If this memory cgroup is not under account moving, we don't
2046 * need to take move_lock_mem_cgroup(). Because we already hold
2047 * rcu_read_lock(), any calls to move_account will be delayed until
2048 * rcu_read_unlock() if mem_cgroup_stolen() == true.
2050 if (!mem_cgroup_stolen(memcg))
2053 move_lock_mem_cgroup(memcg, flags);
2054 if (memcg != pc->mem_cgroup || !PageCgroupUsed(pc)) {
2055 move_unlock_mem_cgroup(memcg, flags);
2061 void __mem_cgroup_end_update_page_stat(struct page *page, unsigned long *flags)
2063 struct page_cgroup *pc = lookup_page_cgroup(page);
2066 * It's guaranteed that pc->mem_cgroup never changes while
2067 * lock is held because a routine modifies pc->mem_cgroup
2068 * should take move_lock_mem_cgroup().
2070 move_unlock_mem_cgroup(pc->mem_cgroup, flags);
2073 void mem_cgroup_update_page_stat(struct page *page,
2074 enum mem_cgroup_page_stat_item idx, int val)
2076 struct mem_cgroup *memcg;
2077 struct page_cgroup *pc = lookup_page_cgroup(page);
2078 unsigned long uninitialized_var(flags);
2080 if (mem_cgroup_disabled())
2083 memcg = pc->mem_cgroup;
2084 if (unlikely(!memcg || !PageCgroupUsed(pc)))
2088 case MEMCG_NR_FILE_MAPPED:
2089 idx = MEM_CGROUP_STAT_FILE_MAPPED;
2095 this_cpu_add(memcg->stat->count[idx], val);
2099 * size of first charge trial. "32" comes from vmscan.c's magic value.
2100 * TODO: maybe necessary to use big numbers in big irons.
2102 #define CHARGE_BATCH 32U
2103 struct memcg_stock_pcp {
2104 struct mem_cgroup *cached; /* this never be root cgroup */
2105 unsigned int nr_pages;
2106 struct work_struct work;
2107 unsigned long flags;
2108 #define FLUSHING_CACHED_CHARGE 0
2110 static DEFINE_PER_CPU(struct memcg_stock_pcp, memcg_stock);
2111 static DEFINE_MUTEX(percpu_charge_mutex);
2114 * consume_stock: Try to consume stocked charge on this cpu.
2115 * @memcg: memcg to consume from.
2116 * @nr_pages: how many pages to charge.
2118 * The charges will only happen if @memcg matches the current cpu's memcg
2119 * stock, and at least @nr_pages are available in that stock. Failure to
2120 * service an allocation will refill the stock.
2122 * returns true if successful, false otherwise.
2124 static bool consume_stock(struct mem_cgroup *memcg, unsigned int nr_pages)
2126 struct memcg_stock_pcp *stock;
2129 if (nr_pages > CHARGE_BATCH)
2132 stock = &get_cpu_var(memcg_stock);
2133 if (memcg == stock->cached && stock->nr_pages >= nr_pages)
2134 stock->nr_pages -= nr_pages;
2135 else /* need to call res_counter_charge */
2137 put_cpu_var(memcg_stock);
2142 * Returns stocks cached in percpu to res_counter and reset cached information.
2144 static void drain_stock(struct memcg_stock_pcp *stock)
2146 struct mem_cgroup *old = stock->cached;
2148 if (stock->nr_pages) {
2149 unsigned long bytes = stock->nr_pages * PAGE_SIZE;
2151 res_counter_uncharge(&old->res, bytes);
2152 if (do_swap_account)
2153 res_counter_uncharge(&old->memsw, bytes);
2154 stock->nr_pages = 0;
2156 stock->cached = NULL;
2160 * This must be called under preempt disabled or must be called by
2161 * a thread which is pinned to local cpu.
2163 static void drain_local_stock(struct work_struct *dummy)
2165 struct memcg_stock_pcp *stock = &__get_cpu_var(memcg_stock);
2167 clear_bit(FLUSHING_CACHED_CHARGE, &stock->flags);
2170 static void __init memcg_stock_init(void)
2174 for_each_possible_cpu(cpu) {
2175 struct memcg_stock_pcp *stock =
2176 &per_cpu(memcg_stock, cpu);
2177 INIT_WORK(&stock->work, drain_local_stock);
2182 * Cache charges(val) which is from res_counter, to local per_cpu area.
2183 * This will be consumed by consume_stock() function, later.
2185 static void refill_stock(struct mem_cgroup *memcg, unsigned int nr_pages)
2187 struct memcg_stock_pcp *stock = &get_cpu_var(memcg_stock);
2189 if (stock->cached != memcg) { /* reset if necessary */
2191 stock->cached = memcg;
2193 stock->nr_pages += nr_pages;
2194 put_cpu_var(memcg_stock);
2198 * Drains all per-CPU charge caches for given root_memcg resp. subtree
2199 * of the hierarchy under it. sync flag says whether we should block
2200 * until the work is done.
2202 static void drain_all_stock(struct mem_cgroup *root_memcg, bool sync)
2206 /* Notify other cpus that system-wide "drain" is running */
2209 for_each_online_cpu(cpu) {
2210 struct memcg_stock_pcp *stock = &per_cpu(memcg_stock, cpu);
2211 struct mem_cgroup *memcg;
2213 memcg = stock->cached;
2214 if (!memcg || !stock->nr_pages)
2216 if (!mem_cgroup_same_or_subtree(root_memcg, memcg))
2218 if (!test_and_set_bit(FLUSHING_CACHED_CHARGE, &stock->flags)) {
2220 drain_local_stock(&stock->work);
2222 schedule_work_on(cpu, &stock->work);
2230 for_each_online_cpu(cpu) {
2231 struct memcg_stock_pcp *stock = &per_cpu(memcg_stock, cpu);
2232 if (test_bit(FLUSHING_CACHED_CHARGE, &stock->flags))
2233 flush_work(&stock->work);
2240 * Tries to drain stocked charges in other cpus. This function is asynchronous
2241 * and just put a work per cpu for draining localy on each cpu. Caller can
2242 * expects some charges will be back to res_counter later but cannot wait for
2245 static void drain_all_stock_async(struct mem_cgroup *root_memcg)
2248 * If someone calls draining, avoid adding more kworker runs.
2250 if (!mutex_trylock(&percpu_charge_mutex))
2252 drain_all_stock(root_memcg, false);
2253 mutex_unlock(&percpu_charge_mutex);
2256 /* This is a synchronous drain interface. */
2257 static void drain_all_stock_sync(struct mem_cgroup *root_memcg)
2259 /* called when force_empty is called */
2260 mutex_lock(&percpu_charge_mutex);
2261 drain_all_stock(root_memcg, true);
2262 mutex_unlock(&percpu_charge_mutex);
2266 * This function drains percpu counter value from DEAD cpu and
2267 * move it to local cpu. Note that this function can be preempted.
2269 static void mem_cgroup_drain_pcp_counter(struct mem_cgroup *memcg, int cpu)
2273 spin_lock(&memcg->pcp_counter_lock);
2274 for (i = 0; i < MEM_CGROUP_STAT_NSTATS; i++) {
2275 long x = per_cpu(memcg->stat->count[i], cpu);
2277 per_cpu(memcg->stat->count[i], cpu) = 0;
2278 memcg->nocpu_base.count[i] += x;
2280 for (i = 0; i < MEM_CGROUP_EVENTS_NSTATS; i++) {
2281 unsigned long x = per_cpu(memcg->stat->events[i], cpu);
2283 per_cpu(memcg->stat->events[i], cpu) = 0;
2284 memcg->nocpu_base.events[i] += x;
2286 spin_unlock(&memcg->pcp_counter_lock);
2289 static int memcg_cpu_hotplug_callback(struct notifier_block *nb,
2290 unsigned long action,
2293 int cpu = (unsigned long)hcpu;
2294 struct memcg_stock_pcp *stock;
2295 struct mem_cgroup *iter;
2297 if (action == CPU_ONLINE)
2300 if (action != CPU_DEAD && action != CPU_DEAD_FROZEN)
2303 for_each_mem_cgroup(iter)
2304 mem_cgroup_drain_pcp_counter(iter, cpu);
2306 stock = &per_cpu(memcg_stock, cpu);
2312 /* See __mem_cgroup_try_charge() for details */
2314 CHARGE_OK, /* success */
2315 CHARGE_RETRY, /* need to retry but retry is not bad */
2316 CHARGE_NOMEM, /* we can't do more. return -ENOMEM */
2317 CHARGE_WOULDBLOCK, /* GFP_WAIT wasn't set and no enough res. */
2318 CHARGE_OOM_DIE, /* the current is killed because of OOM */
2321 static int mem_cgroup_do_charge(struct mem_cgroup *memcg, gfp_t gfp_mask,
2322 unsigned int nr_pages, unsigned int min_pages,
2325 unsigned long csize = nr_pages * PAGE_SIZE;
2326 struct mem_cgroup *mem_over_limit;
2327 struct res_counter *fail_res;
2328 unsigned long flags = 0;
2331 ret = res_counter_charge(&memcg->res, csize, &fail_res);
2334 if (!do_swap_account)
2336 ret = res_counter_charge(&memcg->memsw, csize, &fail_res);
2340 res_counter_uncharge(&memcg->res, csize);
2341 mem_over_limit = mem_cgroup_from_res_counter(fail_res, memsw);
2342 flags |= MEM_CGROUP_RECLAIM_NOSWAP;
2344 mem_over_limit = mem_cgroup_from_res_counter(fail_res, res);
2346 * Never reclaim on behalf of optional batching, retry with a
2347 * single page instead.
2349 if (nr_pages > min_pages)
2350 return CHARGE_RETRY;
2352 if (!(gfp_mask & __GFP_WAIT))
2353 return CHARGE_WOULDBLOCK;
2355 if (gfp_mask & __GFP_NORETRY)
2356 return CHARGE_NOMEM;
2358 ret = mem_cgroup_reclaim(mem_over_limit, gfp_mask, flags);
2359 if (mem_cgroup_margin(mem_over_limit) >= nr_pages)
2360 return CHARGE_RETRY;
2362 * Even though the limit is exceeded at this point, reclaim
2363 * may have been able to free some pages. Retry the charge
2364 * before killing the task.
2366 * Only for regular pages, though: huge pages are rather
2367 * unlikely to succeed so close to the limit, and we fall back
2368 * to regular pages anyway in case of failure.
2370 if (nr_pages <= (1 << PAGE_ALLOC_COSTLY_ORDER) && ret)
2371 return CHARGE_RETRY;
2374 * At task move, charge accounts can be doubly counted. So, it's
2375 * better to wait until the end of task_move if something is going on.
2377 if (mem_cgroup_wait_acct_move(mem_over_limit))
2378 return CHARGE_RETRY;
2380 /* If we don't need to call oom-killer at el, return immediately */
2382 return CHARGE_NOMEM;
2384 if (!mem_cgroup_handle_oom(mem_over_limit, gfp_mask, get_order(csize)))
2385 return CHARGE_OOM_DIE;
2387 return CHARGE_RETRY;
2391 * __mem_cgroup_try_charge() does
2392 * 1. detect memcg to be charged against from passed *mm and *ptr,
2393 * 2. update res_counter
2394 * 3. call memory reclaim if necessary.
2396 * In some special case, if the task is fatal, fatal_signal_pending() or
2397 * has TIF_MEMDIE, this function returns -EINTR while writing root_mem_cgroup
2398 * to *ptr. There are two reasons for this. 1: fatal threads should quit as soon
2399 * as possible without any hazards. 2: all pages should have a valid
2400 * pc->mem_cgroup. If mm is NULL and the caller doesn't pass a valid memcg
2401 * pointer, that is treated as a charge to root_mem_cgroup.
2403 * So __mem_cgroup_try_charge() will return
2404 * 0 ... on success, filling *ptr with a valid memcg pointer.
2405 * -ENOMEM ... charge failure because of resource limits.
2406 * -EINTR ... if thread is fatal. *ptr is filled with root_mem_cgroup.
2408 * Unlike the exported interface, an "oom" parameter is added. if oom==true,
2409 * the oom-killer can be invoked.
2411 static int __mem_cgroup_try_charge(struct mm_struct *mm,
2413 unsigned int nr_pages,
2414 struct mem_cgroup **ptr,
2417 unsigned int batch = max(CHARGE_BATCH, nr_pages);
2418 int nr_oom_retries = MEM_CGROUP_RECLAIM_RETRIES;
2419 struct mem_cgroup *memcg = NULL;
2423 * Unlike gloval-vm's OOM-kill, we're not in memory shortage
2424 * in system level. So, allow to go ahead dying process in addition to
2427 if (unlikely(test_thread_flag(TIF_MEMDIE)
2428 || fatal_signal_pending(current)))
2432 * We always charge the cgroup the mm_struct belongs to.
2433 * The mm_struct's mem_cgroup changes on task migration if the
2434 * thread group leader migrates. It's possible that mm is not
2435 * set, if so charge the root memcg (happens for pagecache usage).
2438 *ptr = root_mem_cgroup;
2440 if (*ptr) { /* css should be a valid one */
2442 if (mem_cgroup_is_root(memcg))
2444 if (consume_stock(memcg, nr_pages))
2446 css_get(&memcg->css);
2448 struct task_struct *p;
2451 p = rcu_dereference(mm->owner);
2453 * Because we don't have task_lock(), "p" can exit.
2454 * In that case, "memcg" can point to root or p can be NULL with
2455 * race with swapoff. Then, we have small risk of mis-accouning.
2456 * But such kind of mis-account by race always happens because
2457 * we don't have cgroup_mutex(). It's overkill and we allo that
2459 * (*) swapoff at el will charge against mm-struct not against
2460 * task-struct. So, mm->owner can be NULL.
2462 memcg = mem_cgroup_from_task(p);
2464 memcg = root_mem_cgroup;
2465 if (mem_cgroup_is_root(memcg)) {
2469 if (consume_stock(memcg, nr_pages)) {
2471 * It seems dagerous to access memcg without css_get().
2472 * But considering how consume_stok works, it's not
2473 * necessary. If consume_stock success, some charges
2474 * from this memcg are cached on this cpu. So, we
2475 * don't need to call css_get()/css_tryget() before
2476 * calling consume_stock().
2481 /* after here, we may be blocked. we need to get refcnt */
2482 if (!css_tryget(&memcg->css)) {
2492 /* If killed, bypass charge */
2493 if (fatal_signal_pending(current)) {
2494 css_put(&memcg->css);
2499 if (oom && !nr_oom_retries) {
2501 nr_oom_retries = MEM_CGROUP_RECLAIM_RETRIES;
2504 ret = mem_cgroup_do_charge(memcg, gfp_mask, batch, nr_pages,
2509 case CHARGE_RETRY: /* not in OOM situation but retry */
2511 css_put(&memcg->css);
2514 case CHARGE_WOULDBLOCK: /* !__GFP_WAIT */
2515 css_put(&memcg->css);
2517 case CHARGE_NOMEM: /* OOM routine works */
2519 css_put(&memcg->css);
2522 /* If oom, we never return -ENOMEM */
2525 case CHARGE_OOM_DIE: /* Killed by OOM Killer */
2526 css_put(&memcg->css);
2529 } while (ret != CHARGE_OK);
2531 if (batch > nr_pages)
2532 refill_stock(memcg, batch - nr_pages);
2533 css_put(&memcg->css);
2541 *ptr = root_mem_cgroup;
2546 * Somemtimes we have to undo a charge we got by try_charge().
2547 * This function is for that and do uncharge, put css's refcnt.
2548 * gotten by try_charge().
2550 static void __mem_cgroup_cancel_charge(struct mem_cgroup *memcg,
2551 unsigned int nr_pages)
2553 if (!mem_cgroup_is_root(memcg)) {
2554 unsigned long bytes = nr_pages * PAGE_SIZE;
2556 res_counter_uncharge(&memcg->res, bytes);
2557 if (do_swap_account)
2558 res_counter_uncharge(&memcg->memsw, bytes);
2563 * Cancel chrages in this cgroup....doesn't propagate to parent cgroup.
2564 * This is useful when moving usage to parent cgroup.
2566 static void __mem_cgroup_cancel_local_charge(struct mem_cgroup *memcg,
2567 unsigned int nr_pages)
2569 unsigned long bytes = nr_pages * PAGE_SIZE;
2571 if (mem_cgroup_is_root(memcg))
2574 res_counter_uncharge_until(&memcg->res, memcg->res.parent, bytes);
2575 if (do_swap_account)
2576 res_counter_uncharge_until(&memcg->memsw,
2577 memcg->memsw.parent, bytes);
2581 * A helper function to get mem_cgroup from ID. must be called under
2582 * rcu_read_lock(). The caller is responsible for calling css_tryget if
2583 * the mem_cgroup is used for charging. (dropping refcnt from swap can be
2584 * called against removed memcg.)
2586 static struct mem_cgroup *mem_cgroup_lookup(unsigned short id)
2588 struct cgroup_subsys_state *css;
2590 /* ID 0 is unused ID */
2593 css = css_lookup(&mem_cgroup_subsys, id);
2596 return mem_cgroup_from_css(css);
2599 struct mem_cgroup *try_get_mem_cgroup_from_page(struct page *page)
2601 struct mem_cgroup *memcg = NULL;
2602 struct page_cgroup *pc;
2606 VM_BUG_ON(!PageLocked(page));
2608 pc = lookup_page_cgroup(page);
2609 lock_page_cgroup(pc);
2610 if (PageCgroupUsed(pc)) {
2611 memcg = pc->mem_cgroup;
2612 if (memcg && !css_tryget(&memcg->css))
2614 } else if (PageSwapCache(page)) {
2615 ent.val = page_private(page);
2616 id = lookup_swap_cgroup_id(ent);
2618 memcg = mem_cgroup_lookup(id);
2619 if (memcg && !css_tryget(&memcg->css))
2623 unlock_page_cgroup(pc);
2627 static void __mem_cgroup_commit_charge(struct mem_cgroup *memcg,
2629 unsigned int nr_pages,
2630 enum charge_type ctype,
2633 struct page_cgroup *pc = lookup_page_cgroup(page);
2634 struct zone *uninitialized_var(zone);
2635 struct lruvec *lruvec;
2636 bool was_on_lru = false;
2639 lock_page_cgroup(pc);
2640 VM_BUG_ON(PageCgroupUsed(pc));
2642 * we don't need page_cgroup_lock about tail pages, becase they are not
2643 * accessed by any other context at this point.
2647 * In some cases, SwapCache and FUSE(splice_buf->radixtree), the page
2648 * may already be on some other mem_cgroup's LRU. Take care of it.
2651 zone = page_zone(page);
2652 spin_lock_irq(&zone->lru_lock);
2653 if (PageLRU(page)) {
2654 lruvec = mem_cgroup_zone_lruvec(zone, pc->mem_cgroup);
2656 del_page_from_lru_list(page, lruvec, page_lru(page));
2661 pc->mem_cgroup = memcg;
2663 * We access a page_cgroup asynchronously without lock_page_cgroup().
2664 * Especially when a page_cgroup is taken from a page, pc->mem_cgroup
2665 * is accessed after testing USED bit. To make pc->mem_cgroup visible
2666 * before USED bit, we need memory barrier here.
2667 * See mem_cgroup_add_lru_list(), etc.
2670 SetPageCgroupUsed(pc);
2674 lruvec = mem_cgroup_zone_lruvec(zone, pc->mem_cgroup);
2675 VM_BUG_ON(PageLRU(page));
2677 add_page_to_lru_list(page, lruvec, page_lru(page));
2679 spin_unlock_irq(&zone->lru_lock);
2682 if (ctype == MEM_CGROUP_CHARGE_TYPE_ANON)
2687 mem_cgroup_charge_statistics(memcg, page, anon, nr_pages);
2688 unlock_page_cgroup(pc);
2691 * "charge_statistics" updated event counter.
2693 memcg_check_events(memcg, page);
2696 static DEFINE_MUTEX(set_limit_mutex);
2698 #ifdef CONFIG_MEMCG_KMEM
2699 static inline bool memcg_can_account_kmem(struct mem_cgroup *memcg)
2701 return !mem_cgroup_disabled() && !mem_cgroup_is_root(memcg) &&
2702 (memcg->kmem_account_flags & KMEM_ACCOUNTED_MASK);
2706 * This is a bit cumbersome, but it is rarely used and avoids a backpointer
2707 * in the memcg_cache_params struct.
2709 static struct kmem_cache *memcg_params_to_cache(struct memcg_cache_params *p)
2711 struct kmem_cache *cachep;
2713 VM_BUG_ON(p->is_root_cache);
2714 cachep = p->root_cache;
2715 return cachep->memcg_params->memcg_caches[memcg_cache_id(p->memcg)];
2718 #ifdef CONFIG_SLABINFO
2719 static int mem_cgroup_slabinfo_read(struct cgroup_subsys_state *css,
2720 struct cftype *cft, struct seq_file *m)
2722 struct mem_cgroup *memcg = mem_cgroup_from_css(css);
2723 struct memcg_cache_params *params;
2725 if (!memcg_can_account_kmem(memcg))
2728 print_slabinfo_header(m);
2730 mutex_lock(&memcg->slab_caches_mutex);
2731 list_for_each_entry(params, &memcg->memcg_slab_caches, list)
2732 cache_show(memcg_params_to_cache(params), m);
2733 mutex_unlock(&memcg->slab_caches_mutex);
2739 static int memcg_charge_kmem(struct mem_cgroup *memcg, gfp_t gfp, u64 size)
2741 struct res_counter *fail_res;
2742 struct mem_cgroup *_memcg;
2746 ret = res_counter_charge(&memcg->kmem, size, &fail_res);
2751 * Conditions under which we can wait for the oom_killer. Those are
2752 * the same conditions tested by the core page allocator
2754 may_oom = (gfp & __GFP_FS) && !(gfp & __GFP_NORETRY);
2757 ret = __mem_cgroup_try_charge(NULL, gfp, size >> PAGE_SHIFT,
2760 if (ret == -EINTR) {
2762 * __mem_cgroup_try_charge() chosed to bypass to root due to
2763 * OOM kill or fatal signal. Since our only options are to
2764 * either fail the allocation or charge it to this cgroup, do
2765 * it as a temporary condition. But we can't fail. From a
2766 * kmem/slab perspective, the cache has already been selected,
2767 * by mem_cgroup_kmem_get_cache(), so it is too late to change
2770 * This condition will only trigger if the task entered
2771 * memcg_charge_kmem in a sane state, but was OOM-killed during
2772 * __mem_cgroup_try_charge() above. Tasks that were already
2773 * dying when the allocation triggers should have been already
2774 * directed to the root cgroup in memcontrol.h
2776 res_counter_charge_nofail(&memcg->res, size, &fail_res);
2777 if (do_swap_account)
2778 res_counter_charge_nofail(&memcg->memsw, size,
2782 res_counter_uncharge(&memcg->kmem, size);
2787 static void memcg_uncharge_kmem(struct mem_cgroup *memcg, u64 size)
2789 res_counter_uncharge(&memcg->res, size);
2790 if (do_swap_account)
2791 res_counter_uncharge(&memcg->memsw, size);
2794 if (res_counter_uncharge(&memcg->kmem, size))
2798 * Releases a reference taken in kmem_cgroup_css_offline in case
2799 * this last uncharge is racing with the offlining code or it is
2800 * outliving the memcg existence.
2802 * The memory barrier imposed by test&clear is paired with the
2803 * explicit one in memcg_kmem_mark_dead().
2805 if (memcg_kmem_test_and_clear_dead(memcg))
2806 css_put(&memcg->css);
2809 void memcg_cache_list_add(struct mem_cgroup *memcg, struct kmem_cache *cachep)
2814 mutex_lock(&memcg->slab_caches_mutex);
2815 list_add(&cachep->memcg_params->list, &memcg->memcg_slab_caches);
2816 mutex_unlock(&memcg->slab_caches_mutex);
2820 * helper for acessing a memcg's index. It will be used as an index in the
2821 * child cache array in kmem_cache, and also to derive its name. This function
2822 * will return -1 when this is not a kmem-limited memcg.
2824 int memcg_cache_id(struct mem_cgroup *memcg)
2826 return memcg ? memcg->kmemcg_id : -1;
2830 * This ends up being protected by the set_limit mutex, during normal
2831 * operation, because that is its main call site.
2833 * But when we create a new cache, we can call this as well if its parent
2834 * is kmem-limited. That will have to hold set_limit_mutex as well.
2836 int memcg_update_cache_sizes(struct mem_cgroup *memcg)
2840 num = ida_simple_get(&kmem_limited_groups,
2841 0, MEMCG_CACHES_MAX_SIZE, GFP_KERNEL);
2845 * After this point, kmem_accounted (that we test atomically in
2846 * the beginning of this conditional), is no longer 0. This
2847 * guarantees only one process will set the following boolean
2848 * to true. We don't need test_and_set because we're protected
2849 * by the set_limit_mutex anyway.
2851 memcg_kmem_set_activated(memcg);
2853 ret = memcg_update_all_caches(num+1);
2855 ida_simple_remove(&kmem_limited_groups, num);
2856 memcg_kmem_clear_activated(memcg);
2860 memcg->kmemcg_id = num;
2861 INIT_LIST_HEAD(&memcg->memcg_slab_caches);
2862 mutex_init(&memcg->slab_caches_mutex);
2866 static size_t memcg_caches_array_size(int num_groups)
2869 if (num_groups <= 0)
2872 size = 2 * num_groups;
2873 if (size < MEMCG_CACHES_MIN_SIZE)
2874 size = MEMCG_CACHES_MIN_SIZE;
2875 else if (size > MEMCG_CACHES_MAX_SIZE)
2876 size = MEMCG_CACHES_MAX_SIZE;
2882 * We should update the current array size iff all caches updates succeed. This
2883 * can only be done from the slab side. The slab mutex needs to be held when
2886 void memcg_update_array_size(int num)
2888 if (num > memcg_limited_groups_array_size)
2889 memcg_limited_groups_array_size = memcg_caches_array_size(num);
2892 static void kmem_cache_destroy_work_func(struct work_struct *w);
2894 int memcg_update_cache_size(struct kmem_cache *s, int num_groups)
2896 struct memcg_cache_params *cur_params = s->memcg_params;
2898 VM_BUG_ON(s->memcg_params && !s->memcg_params->is_root_cache);
2900 if (num_groups > memcg_limited_groups_array_size) {
2902 ssize_t size = memcg_caches_array_size(num_groups);
2904 size *= sizeof(void *);
2905 size += offsetof(struct memcg_cache_params, memcg_caches);
2907 s->memcg_params = kzalloc(size, GFP_KERNEL);
2908 if (!s->memcg_params) {
2909 s->memcg_params = cur_params;
2913 s->memcg_params->is_root_cache = true;
2916 * There is the chance it will be bigger than
2917 * memcg_limited_groups_array_size, if we failed an allocation
2918 * in a cache, in which case all caches updated before it, will
2919 * have a bigger array.
2921 * But if that is the case, the data after
2922 * memcg_limited_groups_array_size is certainly unused
2924 for (i = 0; i < memcg_limited_groups_array_size; i++) {
2925 if (!cur_params->memcg_caches[i])
2927 s->memcg_params->memcg_caches[i] =
2928 cur_params->memcg_caches[i];
2932 * Ideally, we would wait until all caches succeed, and only
2933 * then free the old one. But this is not worth the extra
2934 * pointer per-cache we'd have to have for this.
2936 * It is not a big deal if some caches are left with a size
2937 * bigger than the others. And all updates will reset this
2945 int memcg_register_cache(struct mem_cgroup *memcg, struct kmem_cache *s,
2946 struct kmem_cache *root_cache)
2950 if (!memcg_kmem_enabled())
2954 size = offsetof(struct memcg_cache_params, memcg_caches);
2955 size += memcg_limited_groups_array_size * sizeof(void *);
2957 size = sizeof(struct memcg_cache_params);
2959 s->memcg_params = kzalloc(size, GFP_KERNEL);
2960 if (!s->memcg_params)
2964 s->memcg_params->memcg = memcg;
2965 s->memcg_params->root_cache = root_cache;
2966 INIT_WORK(&s->memcg_params->destroy,
2967 kmem_cache_destroy_work_func);
2969 s->memcg_params->is_root_cache = true;
2974 void memcg_release_cache(struct kmem_cache *s)
2976 struct kmem_cache *root;
2977 struct mem_cgroup *memcg;
2981 * This happens, for instance, when a root cache goes away before we
2984 if (!s->memcg_params)
2987 if (s->memcg_params->is_root_cache)
2990 memcg = s->memcg_params->memcg;
2991 id = memcg_cache_id(memcg);
2993 root = s->memcg_params->root_cache;
2994 root->memcg_params->memcg_caches[id] = NULL;
2996 mutex_lock(&memcg->slab_caches_mutex);
2997 list_del(&s->memcg_params->list);
2998 mutex_unlock(&memcg->slab_caches_mutex);
3000 css_put(&memcg->css);
3002 kfree(s->memcg_params);
3006 * During the creation a new cache, we need to disable our accounting mechanism
3007 * altogether. This is true even if we are not creating, but rather just
3008 * enqueing new caches to be created.
3010 * This is because that process will trigger allocations; some visible, like
3011 * explicit kmallocs to auxiliary data structures, name strings and internal
3012 * cache structures; some well concealed, like INIT_WORK() that can allocate
3013 * objects during debug.
3015 * If any allocation happens during memcg_kmem_get_cache, we will recurse back
3016 * to it. This may not be a bounded recursion: since the first cache creation
3017 * failed to complete (waiting on the allocation), we'll just try to create the
3018 * cache again, failing at the same point.
3020 * memcg_kmem_get_cache is prepared to abort after seeing a positive count of
3021 * memcg_kmem_skip_account. So we enclose anything that might allocate memory
3022 * inside the following two functions.
3024 static inline void memcg_stop_kmem_account(void)
3026 VM_BUG_ON(!current->mm);
3027 current->memcg_kmem_skip_account++;
3030 static inline void memcg_resume_kmem_account(void)
3032 VM_BUG_ON(!current->mm);
3033 current->memcg_kmem_skip_account--;
3036 static void kmem_cache_destroy_work_func(struct work_struct *w)
3038 struct kmem_cache *cachep;
3039 struct memcg_cache_params *p;
3041 p = container_of(w, struct memcg_cache_params, destroy);
3043 cachep = memcg_params_to_cache(p);
3046 * If we get down to 0 after shrink, we could delete right away.
3047 * However, memcg_release_pages() already puts us back in the workqueue
3048 * in that case. If we proceed deleting, we'll get a dangling
3049 * reference, and removing the object from the workqueue in that case
3050 * is unnecessary complication. We are not a fast path.
3052 * Note that this case is fundamentally different from racing with
3053 * shrink_slab(): if memcg_cgroup_destroy_cache() is called in
3054 * kmem_cache_shrink, not only we would be reinserting a dead cache
3055 * into the queue, but doing so from inside the worker racing to
3058 * So if we aren't down to zero, we'll just schedule a worker and try
3061 if (atomic_read(&cachep->memcg_params->nr_pages) != 0) {
3062 kmem_cache_shrink(cachep);
3063 if (atomic_read(&cachep->memcg_params->nr_pages) == 0)
3066 kmem_cache_destroy(cachep);
3069 void mem_cgroup_destroy_cache(struct kmem_cache *cachep)
3071 if (!cachep->memcg_params->dead)
3075 * There are many ways in which we can get here.
3077 * We can get to a memory-pressure situation while the delayed work is
3078 * still pending to run. The vmscan shrinkers can then release all
3079 * cache memory and get us to destruction. If this is the case, we'll
3080 * be executed twice, which is a bug (the second time will execute over
3081 * bogus data). In this case, cancelling the work should be fine.
3083 * But we can also get here from the worker itself, if
3084 * kmem_cache_shrink is enough to shake all the remaining objects and
3085 * get the page count to 0. In this case, we'll deadlock if we try to
3086 * cancel the work (the worker runs with an internal lock held, which
3087 * is the same lock we would hold for cancel_work_sync().)
3089 * Since we can't possibly know who got us here, just refrain from
3090 * running if there is already work pending
3092 if (work_pending(&cachep->memcg_params->destroy))
3095 * We have to defer the actual destroying to a workqueue, because
3096 * we might currently be in a context that cannot sleep.
3098 schedule_work(&cachep->memcg_params->destroy);
3102 * This lock protects updaters, not readers. We want readers to be as fast as
3103 * they can, and they will either see NULL or a valid cache value. Our model
3104 * allow them to see NULL, in which case the root memcg will be selected.
3106 * We need this lock because multiple allocations to the same cache from a non
3107 * will span more than one worker. Only one of them can create the cache.
3109 static DEFINE_MUTEX(memcg_cache_mutex);
3112 * Called with memcg_cache_mutex held
3114 static struct kmem_cache *kmem_cache_dup(struct mem_cgroup *memcg,
3115 struct kmem_cache *s)
3117 struct kmem_cache *new;
3118 static char *tmp_name = NULL;
3120 lockdep_assert_held(&memcg_cache_mutex);
3123 * kmem_cache_create_memcg duplicates the given name and
3124 * cgroup_name for this name requires RCU context.
3125 * This static temporary buffer is used to prevent from
3126 * pointless shortliving allocation.
3129 tmp_name = kmalloc(PATH_MAX, GFP_KERNEL);
3135 snprintf(tmp_name, PATH_MAX, "%s(%d:%s)", s->name,
3136 memcg_cache_id(memcg), cgroup_name(memcg->css.cgroup));
3139 new = kmem_cache_create_memcg(memcg, tmp_name, s->object_size, s->align,
3140 (s->flags & ~SLAB_PANIC), s->ctor, s);
3143 new->allocflags |= __GFP_KMEMCG;
3148 static struct kmem_cache *memcg_create_kmem_cache(struct mem_cgroup *memcg,
3149 struct kmem_cache *cachep)
3151 struct kmem_cache *new_cachep;
3154 BUG_ON(!memcg_can_account_kmem(memcg));
3156 idx = memcg_cache_id(memcg);
3158 mutex_lock(&memcg_cache_mutex);
3159 new_cachep = cachep->memcg_params->memcg_caches[idx];
3161 css_put(&memcg->css);
3165 new_cachep = kmem_cache_dup(memcg, cachep);
3166 if (new_cachep == NULL) {
3167 new_cachep = cachep;
3168 css_put(&memcg->css);
3172 atomic_set(&new_cachep->memcg_params->nr_pages , 0);
3174 cachep->memcg_params->memcg_caches[idx] = new_cachep;
3176 * the readers won't lock, make sure everybody sees the updated value,
3177 * so they won't put stuff in the queue again for no reason
3181 mutex_unlock(&memcg_cache_mutex);
3185 void kmem_cache_destroy_memcg_children(struct kmem_cache *s)
3187 struct kmem_cache *c;
3190 if (!s->memcg_params)
3192 if (!s->memcg_params->is_root_cache)
3196 * If the cache is being destroyed, we trust that there is no one else
3197 * requesting objects from it. Even if there are, the sanity checks in
3198 * kmem_cache_destroy should caught this ill-case.
3200 * Still, we don't want anyone else freeing memcg_caches under our
3201 * noses, which can happen if a new memcg comes to life. As usual,
3202 * we'll take the set_limit_mutex to protect ourselves against this.
3204 mutex_lock(&set_limit_mutex);
3205 for (i = 0; i < memcg_limited_groups_array_size; i++) {
3206 c = s->memcg_params->memcg_caches[i];
3211 * We will now manually delete the caches, so to avoid races
3212 * we need to cancel all pending destruction workers and
3213 * proceed with destruction ourselves.
3215 * kmem_cache_destroy() will call kmem_cache_shrink internally,
3216 * and that could spawn the workers again: it is likely that
3217 * the cache still have active pages until this very moment.
3218 * This would lead us back to mem_cgroup_destroy_cache.
3220 * But that will not execute at all if the "dead" flag is not
3221 * set, so flip it down to guarantee we are in control.
3223 c->memcg_params->dead = false;
3224 cancel_work_sync(&c->memcg_params->destroy);
3225 kmem_cache_destroy(c);
3227 mutex_unlock(&set_limit_mutex);
3230 struct create_work {
3231 struct mem_cgroup *memcg;
3232 struct kmem_cache *cachep;
3233 struct work_struct work;
3236 static void mem_cgroup_destroy_all_caches(struct mem_cgroup *memcg)
3238 struct kmem_cache *cachep;
3239 struct memcg_cache_params *params;
3241 if (!memcg_kmem_is_active(memcg))
3244 mutex_lock(&memcg->slab_caches_mutex);
3245 list_for_each_entry(params, &memcg->memcg_slab_caches, list) {
3246 cachep = memcg_params_to_cache(params);
3247 cachep->memcg_params->dead = true;
3248 schedule_work(&cachep->memcg_params->destroy);
3250 mutex_unlock(&memcg->slab_caches_mutex);
3253 static void memcg_create_cache_work_func(struct work_struct *w)
3255 struct create_work *cw;
3257 cw = container_of(w, struct create_work, work);
3258 memcg_create_kmem_cache(cw->memcg, cw->cachep);
3263 * Enqueue the creation of a per-memcg kmem_cache.
3265 static void __memcg_create_cache_enqueue(struct mem_cgroup *memcg,
3266 struct kmem_cache *cachep)
3268 struct create_work *cw;
3270 cw = kmalloc(sizeof(struct create_work), GFP_NOWAIT);
3272 css_put(&memcg->css);
3277 cw->cachep = cachep;
3279 INIT_WORK(&cw->work, memcg_create_cache_work_func);
3280 schedule_work(&cw->work);
3283 static void memcg_create_cache_enqueue(struct mem_cgroup *memcg,
3284 struct kmem_cache *cachep)
3287 * We need to stop accounting when we kmalloc, because if the
3288 * corresponding kmalloc cache is not yet created, the first allocation
3289 * in __memcg_create_cache_enqueue will recurse.
3291 * However, it is better to enclose the whole function. Depending on
3292 * the debugging options enabled, INIT_WORK(), for instance, can
3293 * trigger an allocation. This too, will make us recurse. Because at
3294 * this point we can't allow ourselves back into memcg_kmem_get_cache,
3295 * the safest choice is to do it like this, wrapping the whole function.
3297 memcg_stop_kmem_account();
3298 __memcg_create_cache_enqueue(memcg, cachep);
3299 memcg_resume_kmem_account();
3302 * Return the kmem_cache we're supposed to use for a slab allocation.
3303 * We try to use the current memcg's version of the cache.
3305 * If the cache does not exist yet, if we are the first user of it,
3306 * we either create it immediately, if possible, or create it asynchronously
3308 * In the latter case, we will let the current allocation go through with
3309 * the original cache.
3311 * Can't be called in interrupt context or from kernel threads.
3312 * This function needs to be called with rcu_read_lock() held.
3314 struct kmem_cache *__memcg_kmem_get_cache(struct kmem_cache *cachep,
3317 struct mem_cgroup *memcg;
3320 VM_BUG_ON(!cachep->memcg_params);
3321 VM_BUG_ON(!cachep->memcg_params->is_root_cache);
3323 if (!current->mm || current->memcg_kmem_skip_account)
3327 memcg = mem_cgroup_from_task(rcu_dereference(current->mm->owner));
3329 if (!memcg_can_account_kmem(memcg))
3332 idx = memcg_cache_id(memcg);
3335 * barrier to mare sure we're always seeing the up to date value. The
3336 * code updating memcg_caches will issue a write barrier to match this.
3338 read_barrier_depends();
3339 if (likely(cachep->memcg_params->memcg_caches[idx])) {
3340 cachep = cachep->memcg_params->memcg_caches[idx];
3344 /* The corresponding put will be done in the workqueue. */
3345 if (!css_tryget(&memcg->css))
3350 * If we are in a safe context (can wait, and not in interrupt
3351 * context), we could be be predictable and return right away.
3352 * This would guarantee that the allocation being performed
3353 * already belongs in the new cache.
3355 * However, there are some clashes that can arrive from locking.
3356 * For instance, because we acquire the slab_mutex while doing
3357 * kmem_cache_dup, this means no further allocation could happen
3358 * with the slab_mutex held.
3360 * Also, because cache creation issue get_online_cpus(), this
3361 * creates a lock chain: memcg_slab_mutex -> cpu_hotplug_mutex,
3362 * that ends up reversed during cpu hotplug. (cpuset allocates
3363 * a bunch of GFP_KERNEL memory during cpuup). Due to all that,
3364 * better to defer everything.
3366 memcg_create_cache_enqueue(memcg, cachep);
3372 EXPORT_SYMBOL(__memcg_kmem_get_cache);
3375 * We need to verify if the allocation against current->mm->owner's memcg is
3376 * possible for the given order. But the page is not allocated yet, so we'll
3377 * need a further commit step to do the final arrangements.
3379 * It is possible for the task to switch cgroups in this mean time, so at
3380 * commit time, we can't rely on task conversion any longer. We'll then use
3381 * the handle argument to return to the caller which cgroup we should commit
3382 * against. We could also return the memcg directly and avoid the pointer
3383 * passing, but a boolean return value gives better semantics considering
3384 * the compiled-out case as well.
3386 * Returning true means the allocation is possible.
3389 __memcg_kmem_newpage_charge(gfp_t gfp, struct mem_cgroup **_memcg, int order)
3391 struct mem_cgroup *memcg;
3397 * Disabling accounting is only relevant for some specific memcg
3398 * internal allocations. Therefore we would initially not have such
3399 * check here, since direct calls to the page allocator that are marked
3400 * with GFP_KMEMCG only happen outside memcg core. We are mostly
3401 * concerned with cache allocations, and by having this test at
3402 * memcg_kmem_get_cache, we are already able to relay the allocation to
3403 * the root cache and bypass the memcg cache altogether.
3405 * There is one exception, though: the SLUB allocator does not create
3406 * large order caches, but rather service large kmallocs directly from
3407 * the page allocator. Therefore, the following sequence when backed by
3408 * the SLUB allocator:
3410 * memcg_stop_kmem_account();
3411 * kmalloc(<large_number>)
3412 * memcg_resume_kmem_account();
3414 * would effectively ignore the fact that we should skip accounting,
3415 * since it will drive us directly to this function without passing
3416 * through the cache selector memcg_kmem_get_cache. Such large
3417 * allocations are extremely rare but can happen, for instance, for the
3418 * cache arrays. We bring this test here.
3420 if (!current->mm || current->memcg_kmem_skip_account)
3423 memcg = try_get_mem_cgroup_from_mm(current->mm);
3426 * very rare case described in mem_cgroup_from_task. Unfortunately there
3427 * isn't much we can do without complicating this too much, and it would
3428 * be gfp-dependent anyway. Just let it go
3430 if (unlikely(!memcg))
3433 if (!memcg_can_account_kmem(memcg)) {
3434 css_put(&memcg->css);
3438 ret = memcg_charge_kmem(memcg, gfp, PAGE_SIZE << order);
3442 css_put(&memcg->css);
3446 void __memcg_kmem_commit_charge(struct page *page, struct mem_cgroup *memcg,
3449 struct page_cgroup *pc;
3451 VM_BUG_ON(mem_cgroup_is_root(memcg));
3453 /* The page allocation failed. Revert */
3455 memcg_uncharge_kmem(memcg, PAGE_SIZE << order);
3459 pc = lookup_page_cgroup(page);
3460 lock_page_cgroup(pc);
3461 pc->mem_cgroup = memcg;
3462 SetPageCgroupUsed(pc);
3463 unlock_page_cgroup(pc);
3466 void __memcg_kmem_uncharge_pages(struct page *page, int order)
3468 struct mem_cgroup *memcg = NULL;
3469 struct page_cgroup *pc;
3472 pc = lookup_page_cgroup(page);
3474 * Fast unlocked return. Theoretically might have changed, have to
3475 * check again after locking.
3477 if (!PageCgroupUsed(pc))
3480 lock_page_cgroup(pc);
3481 if (PageCgroupUsed(pc)) {
3482 memcg = pc->mem_cgroup;
3483 ClearPageCgroupUsed(pc);
3485 unlock_page_cgroup(pc);
3488 * We trust that only if there is a memcg associated with the page, it
3489 * is a valid allocation
3494 VM_BUG_ON(mem_cgroup_is_root(memcg));
3495 memcg_uncharge_kmem(memcg, PAGE_SIZE << order);
3498 static inline void mem_cgroup_destroy_all_caches(struct mem_cgroup *memcg)
3501 #endif /* CONFIG_MEMCG_KMEM */
3503 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
3505 #define PCGF_NOCOPY_AT_SPLIT (1 << PCG_LOCK | 1 << PCG_MIGRATION)
3507 * Because tail pages are not marked as "used", set it. We're under
3508 * zone->lru_lock, 'splitting on pmd' and compound_lock.
3509 * charge/uncharge will be never happen and move_account() is done under
3510 * compound_lock(), so we don't have to take care of races.
3512 void mem_cgroup_split_huge_fixup(struct page *head)
3514 struct page_cgroup *head_pc = lookup_page_cgroup(head);
3515 struct page_cgroup *pc;
3516 struct mem_cgroup *memcg;
3519 if (mem_cgroup_disabled())
3522 memcg = head_pc->mem_cgroup;
3523 for (i = 1; i < HPAGE_PMD_NR; i++) {
3525 pc->mem_cgroup = memcg;
3526 smp_wmb();/* see __commit_charge() */
3527 pc->flags = head_pc->flags & ~PCGF_NOCOPY_AT_SPLIT;
3529 __this_cpu_sub(memcg->stat->count[MEM_CGROUP_STAT_RSS_HUGE],
3532 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
3535 * mem_cgroup_move_account - move account of the page
3537 * @nr_pages: number of regular pages (>1 for huge pages)
3538 * @pc: page_cgroup of the page.
3539 * @from: mem_cgroup which the page is moved from.
3540 * @to: mem_cgroup which the page is moved to. @from != @to.
3542 * The caller must confirm following.
3543 * - page is not on LRU (isolate_page() is useful.)
3544 * - compound_lock is held when nr_pages > 1
3546 * This function doesn't do "charge" to new cgroup and doesn't do "uncharge"
3549 static int mem_cgroup_move_account(struct page *page,
3550 unsigned int nr_pages,
3551 struct page_cgroup *pc,
3552 struct mem_cgroup *from,
3553 struct mem_cgroup *to)
3555 unsigned long flags;
3557 bool anon = PageAnon(page);
3559 VM_BUG_ON(from == to);
3560 VM_BUG_ON(PageLRU(page));
3562 * The page is isolated from LRU. So, collapse function
3563 * will not handle this page. But page splitting can happen.
3564 * Do this check under compound_page_lock(). The caller should
3568 if (nr_pages > 1 && !PageTransHuge(page))
3571 lock_page_cgroup(pc);
3574 if (!PageCgroupUsed(pc) || pc->mem_cgroup != from)
3577 move_lock_mem_cgroup(from, &flags);
3579 if (!anon && page_mapped(page)) {
3580 /* Update mapped_file data for mem_cgroup */
3582 __this_cpu_dec(from->stat->count[MEM_CGROUP_STAT_FILE_MAPPED]);
3583 __this_cpu_inc(to->stat->count[MEM_CGROUP_STAT_FILE_MAPPED]);
3586 mem_cgroup_charge_statistics(from, page, anon, -nr_pages);
3588 /* caller should have done css_get */
3589 pc->mem_cgroup = to;
3590 mem_cgroup_charge_statistics(to, page, anon, nr_pages);
3591 move_unlock_mem_cgroup(from, &flags);
3594 unlock_page_cgroup(pc);
3598 memcg_check_events(to, page);
3599 memcg_check_events(from, page);
3605 * mem_cgroup_move_parent - moves page to the parent group
3606 * @page: the page to move
3607 * @pc: page_cgroup of the page
3608 * @child: page's cgroup
3610 * move charges to its parent or the root cgroup if the group has no
3611 * parent (aka use_hierarchy==0).
3612 * Although this might fail (get_page_unless_zero, isolate_lru_page or
3613 * mem_cgroup_move_account fails) the failure is always temporary and
3614 * it signals a race with a page removal/uncharge or migration. In the
3615 * first case the page is on the way out and it will vanish from the LRU
3616 * on the next attempt and the call should be retried later.
3617 * Isolation from the LRU fails only if page has been isolated from
3618 * the LRU since we looked at it and that usually means either global
3619 * reclaim or migration going on. The page will either get back to the
3621 * Finaly mem_cgroup_move_account fails only if the page got uncharged
3622 * (!PageCgroupUsed) or moved to a different group. The page will
3623 * disappear in the next attempt.
3625 static int mem_cgroup_move_parent(struct page *page,
3626 struct page_cgroup *pc,
3627 struct mem_cgroup *child)
3629 struct mem_cgroup *parent;
3630 unsigned int nr_pages;
3631 unsigned long uninitialized_var(flags);
3634 VM_BUG_ON(mem_cgroup_is_root(child));
3637 if (!get_page_unless_zero(page))
3639 if (isolate_lru_page(page))
3642 nr_pages = hpage_nr_pages(page);
3644 parent = parent_mem_cgroup(child);
3646 * If no parent, move charges to root cgroup.
3649 parent = root_mem_cgroup;
3652 VM_BUG_ON(!PageTransHuge(page));
3653 flags = compound_lock_irqsave(page);
3656 ret = mem_cgroup_move_account(page, nr_pages,
3659 __mem_cgroup_cancel_local_charge(child, nr_pages);
3662 compound_unlock_irqrestore(page, flags);
3663 putback_lru_page(page);
3671 * Charge the memory controller for page usage.
3673 * 0 if the charge was successful
3674 * < 0 if the cgroup is over its limit
3676 static int mem_cgroup_charge_common(struct page *page, struct mm_struct *mm,
3677 gfp_t gfp_mask, enum charge_type ctype)
3679 struct mem_cgroup *memcg = NULL;
3680 unsigned int nr_pages = 1;
3684 if (PageTransHuge(page)) {
3685 nr_pages <<= compound_order(page);
3686 VM_BUG_ON(!PageTransHuge(page));
3688 * Never OOM-kill a process for a huge page. The
3689 * fault handler will fall back to regular pages.
3694 ret = __mem_cgroup_try_charge(mm, gfp_mask, nr_pages, &memcg, oom);
3697 __mem_cgroup_commit_charge(memcg, page, nr_pages, ctype, false);
3701 int mem_cgroup_newpage_charge(struct page *page,
3702 struct mm_struct *mm, gfp_t gfp_mask)
3704 if (mem_cgroup_disabled())
3706 VM_BUG_ON(page_mapped(page));
3707 VM_BUG_ON(page->mapping && !PageAnon(page));
3709 return mem_cgroup_charge_common(page, mm, gfp_mask,
3710 MEM_CGROUP_CHARGE_TYPE_ANON);
3714 * While swap-in, try_charge -> commit or cancel, the page is locked.
3715 * And when try_charge() successfully returns, one refcnt to memcg without
3716 * struct page_cgroup is acquired. This refcnt will be consumed by
3717 * "commit()" or removed by "cancel()"
3719 static int __mem_cgroup_try_charge_swapin(struct mm_struct *mm,
3722 struct mem_cgroup **memcgp)
3724 struct mem_cgroup *memcg;
3725 struct page_cgroup *pc;
3728 pc = lookup_page_cgroup(page);
3730 * Every swap fault against a single page tries to charge the
3731 * page, bail as early as possible. shmem_unuse() encounters
3732 * already charged pages, too. The USED bit is protected by
3733 * the page lock, which serializes swap cache removal, which
3734 * in turn serializes uncharging.
3736 if (PageCgroupUsed(pc))
3738 if (!do_swap_account)
3740 memcg = try_get_mem_cgroup_from_page(page);
3744 ret = __mem_cgroup_try_charge(NULL, mask, 1, memcgp, true);
3745 css_put(&memcg->css);
3750 ret = __mem_cgroup_try_charge(mm, mask, 1, memcgp, true);
3756 int mem_cgroup_try_charge_swapin(struct mm_struct *mm, struct page *page,
3757 gfp_t gfp_mask, struct mem_cgroup **memcgp)
3760 if (mem_cgroup_disabled())
3763 * A racing thread's fault, or swapoff, may have already
3764 * updated the pte, and even removed page from swap cache: in
3765 * those cases unuse_pte()'s pte_same() test will fail; but
3766 * there's also a KSM case which does need to charge the page.
3768 if (!PageSwapCache(page)) {
3771 ret = __mem_cgroup_try_charge(mm, gfp_mask, 1, memcgp, true);
3776 return __mem_cgroup_try_charge_swapin(mm, page, gfp_mask, memcgp);
3779 void mem_cgroup_cancel_charge_swapin(struct mem_cgroup *memcg)
3781 if (mem_cgroup_disabled())
3785 __mem_cgroup_cancel_charge(memcg, 1);
3789 __mem_cgroup_commit_charge_swapin(struct page *page, struct mem_cgroup *memcg,
3790 enum charge_type ctype)
3792 if (mem_cgroup_disabled())
3797 __mem_cgroup_commit_charge(memcg, page, 1, ctype, true);
3799 * Now swap is on-memory. This means this page may be
3800 * counted both as mem and swap....double count.
3801 * Fix it by uncharging from memsw. Basically, this SwapCache is stable
3802 * under lock_page(). But in do_swap_page()::memory.c, reuse_swap_page()
3803 * may call delete_from_swap_cache() before reach here.
3805 if (do_swap_account && PageSwapCache(page)) {
3806 swp_entry_t ent = {.val = page_private(page)};
3807 mem_cgroup_uncharge_swap(ent);
3811 void mem_cgroup_commit_charge_swapin(struct page *page,
3812 struct mem_cgroup *memcg)
3814 __mem_cgroup_commit_charge_swapin(page, memcg,
3815 MEM_CGROUP_CHARGE_TYPE_ANON);
3818 int mem_cgroup_cache_charge(struct page *page, struct mm_struct *mm,
3821 struct mem_cgroup *memcg = NULL;
3822 enum charge_type type = MEM_CGROUP_CHARGE_TYPE_CACHE;
3825 if (mem_cgroup_disabled())
3827 if (PageCompound(page))
3830 if (!PageSwapCache(page))
3831 ret = mem_cgroup_charge_common(page, mm, gfp_mask, type);
3832 else { /* page is swapcache/shmem */
3833 ret = __mem_cgroup_try_charge_swapin(mm, page,
3836 __mem_cgroup_commit_charge_swapin(page, memcg, type);
3841 static void mem_cgroup_do_uncharge(struct mem_cgroup *memcg,
3842 unsigned int nr_pages,
3843 const enum charge_type ctype)
3845 struct memcg_batch_info *batch = NULL;
3846 bool uncharge_memsw = true;
3848 /* If swapout, usage of swap doesn't decrease */
3849 if (!do_swap_account || ctype == MEM_CGROUP_CHARGE_TYPE_SWAPOUT)
3850 uncharge_memsw = false;
3852 batch = ¤t->memcg_batch;
3854 * In usual, we do css_get() when we remember memcg pointer.
3855 * But in this case, we keep res->usage until end of a series of
3856 * uncharges. Then, it's ok to ignore memcg's refcnt.
3859 batch->memcg = memcg;
3861 * do_batch > 0 when unmapping pages or inode invalidate/truncate.
3862 * In those cases, all pages freed continuously can be expected to be in
3863 * the same cgroup and we have chance to coalesce uncharges.
3864 * But we do uncharge one by one if this is killed by OOM(TIF_MEMDIE)
3865 * because we want to do uncharge as soon as possible.
3868 if (!batch->do_batch || test_thread_flag(TIF_MEMDIE))
3869 goto direct_uncharge;
3872 goto direct_uncharge;
3875 * In typical case, batch->memcg == mem. This means we can
3876 * merge a series of uncharges to an uncharge of res_counter.
3877 * If not, we uncharge res_counter ony by one.
3879 if (batch->memcg != memcg)
3880 goto direct_uncharge;
3881 /* remember freed charge and uncharge it later */
3884 batch->memsw_nr_pages++;
3887 res_counter_uncharge(&memcg->res, nr_pages * PAGE_SIZE);
3889 res_counter_uncharge(&memcg->memsw, nr_pages * PAGE_SIZE);
3890 if (unlikely(batch->memcg != memcg))
3891 memcg_oom_recover(memcg);
3895 * uncharge if !page_mapped(page)
3897 static struct mem_cgroup *
3898 __mem_cgroup_uncharge_common(struct page *page, enum charge_type ctype,
3901 struct mem_cgroup *memcg = NULL;
3902 unsigned int nr_pages = 1;
3903 struct page_cgroup *pc;
3906 if (mem_cgroup_disabled())
3909 if (PageTransHuge(page)) {
3910 nr_pages <<= compound_order(page);
3911 VM_BUG_ON(!PageTransHuge(page));
3914 * Check if our page_cgroup is valid
3916 pc = lookup_page_cgroup(page);
3917 if (unlikely(!PageCgroupUsed(pc)))
3920 lock_page_cgroup(pc);
3922 memcg = pc->mem_cgroup;
3924 if (!PageCgroupUsed(pc))
3927 anon = PageAnon(page);
3930 case MEM_CGROUP_CHARGE_TYPE_ANON:
3932 * Generally PageAnon tells if it's the anon statistics to be
3933 * updated; but sometimes e.g. mem_cgroup_uncharge_page() is
3934 * used before page reached the stage of being marked PageAnon.
3938 case MEM_CGROUP_CHARGE_TYPE_DROP:
3939 /* See mem_cgroup_prepare_migration() */
3940 if (page_mapped(page))
3943 * Pages under migration may not be uncharged. But
3944 * end_migration() /must/ be the one uncharging the
3945 * unused post-migration page and so it has to call
3946 * here with the migration bit still set. See the
3947 * res_counter handling below.
3949 if (!end_migration && PageCgroupMigration(pc))
3952 case MEM_CGROUP_CHARGE_TYPE_SWAPOUT:
3953 if (!PageAnon(page)) { /* Shared memory */
3954 if (page->mapping && !page_is_file_cache(page))
3956 } else if (page_mapped(page)) /* Anon */
3963 mem_cgroup_charge_statistics(memcg, page, anon, -nr_pages);
3965 ClearPageCgroupUsed(pc);
3967 * pc->mem_cgroup is not cleared here. It will be accessed when it's
3968 * freed from LRU. This is safe because uncharged page is expected not
3969 * to be reused (freed soon). Exception is SwapCache, it's handled by
3970 * special functions.
3973 unlock_page_cgroup(pc);
3975 * even after unlock, we have memcg->res.usage here and this memcg
3976 * will never be freed, so it's safe to call css_get().
3978 memcg_check_events(memcg, page);
3979 if (do_swap_account && ctype == MEM_CGROUP_CHARGE_TYPE_SWAPOUT) {
3980 mem_cgroup_swap_statistics(memcg, true);
3981 css_get(&memcg->css);
3984 * Migration does not charge the res_counter for the
3985 * replacement page, so leave it alone when phasing out the
3986 * page that is unused after the migration.
3988 if (!end_migration && !mem_cgroup_is_root(memcg))
3989 mem_cgroup_do_uncharge(memcg, nr_pages, ctype);
3994 unlock_page_cgroup(pc);
3998 void mem_cgroup_uncharge_page(struct page *page)
4001 if (page_mapped(page))
4003 VM_BUG_ON(page->mapping && !PageAnon(page));
4005 * If the page is in swap cache, uncharge should be deferred
4006 * to the swap path, which also properly accounts swap usage
4007 * and handles memcg lifetime.
4009 * Note that this check is not stable and reclaim may add the
4010 * page to swap cache at any time after this. However, if the
4011 * page is not in swap cache by the time page->mapcount hits
4012 * 0, there won't be any page table references to the swap
4013 * slot, and reclaim will free it and not actually write the
4016 if (PageSwapCache(page))
4018 __mem_cgroup_uncharge_common(page, MEM_CGROUP_CHARGE_TYPE_ANON, false);
4021 void mem_cgroup_uncharge_cache_page(struct page *page)
4023 VM_BUG_ON(page_mapped(page));
4024 VM_BUG_ON(page->mapping);
4025 __mem_cgroup_uncharge_common(page, MEM_CGROUP_CHARGE_TYPE_CACHE, false);
4029 * Batch_start/batch_end is called in unmap_page_range/invlidate/trucate.
4030 * In that cases, pages are freed continuously and we can expect pages
4031 * are in the same memcg. All these calls itself limits the number of
4032 * pages freed at once, then uncharge_start/end() is called properly.
4033 * This may be called prural(2) times in a context,
4036 void mem_cgroup_uncharge_start(void)
4038 current->memcg_batch.do_batch++;
4039 /* We can do nest. */
4040 if (current->memcg_batch.do_batch == 1) {
4041 current->memcg_batch.memcg = NULL;
4042 current->memcg_batch.nr_pages = 0;
4043 current->memcg_batch.memsw_nr_pages = 0;
4047 void mem_cgroup_uncharge_end(void)
4049 struct memcg_batch_info *batch = ¤t->memcg_batch;
4051 if (!batch->do_batch)
4055 if (batch->do_batch) /* If stacked, do nothing. */
4061 * This "batch->memcg" is valid without any css_get/put etc...
4062 * bacause we hide charges behind us.
4064 if (batch->nr_pages)
4065 res_counter_uncharge(&batch->memcg->res,
4066 batch->nr_pages * PAGE_SIZE);
4067 if (batch->memsw_nr_pages)
4068 res_counter_uncharge(&batch->memcg->memsw,
4069 batch->memsw_nr_pages * PAGE_SIZE);
4070 memcg_oom_recover(batch->memcg);
4071 /* forget this pointer (for sanity check) */
4072 batch->memcg = NULL;
4077 * called after __delete_from_swap_cache() and drop "page" account.
4078 * memcg information is recorded to swap_cgroup of "ent"
4081 mem_cgroup_uncharge_swapcache(struct page *page, swp_entry_t ent, bool swapout)
4083 struct mem_cgroup *memcg;
4084 int ctype = MEM_CGROUP_CHARGE_TYPE_SWAPOUT;
4086 if (!swapout) /* this was a swap cache but the swap is unused ! */
4087 ctype = MEM_CGROUP_CHARGE_TYPE_DROP;
4089 memcg = __mem_cgroup_uncharge_common(page, ctype, false);
4092 * record memcg information, if swapout && memcg != NULL,
4093 * css_get() was called in uncharge().
4095 if (do_swap_account && swapout && memcg)
4096 swap_cgroup_record(ent, css_id(&memcg->css));
4100 #ifdef CONFIG_MEMCG_SWAP
4102 * called from swap_entry_free(). remove record in swap_cgroup and
4103 * uncharge "memsw" account.
4105 void mem_cgroup_uncharge_swap(swp_entry_t ent)
4107 struct mem_cgroup *memcg;
4110 if (!do_swap_account)
4113 id = swap_cgroup_record(ent, 0);
4115 memcg = mem_cgroup_lookup(id);
4118 * We uncharge this because swap is freed.
4119 * This memcg can be obsolete one. We avoid calling css_tryget
4121 if (!mem_cgroup_is_root(memcg))
4122 res_counter_uncharge(&memcg->memsw, PAGE_SIZE);
4123 mem_cgroup_swap_statistics(memcg, false);
4124 css_put(&memcg->css);
4130 * mem_cgroup_move_swap_account - move swap charge and swap_cgroup's record.
4131 * @entry: swap entry to be moved
4132 * @from: mem_cgroup which the entry is moved from
4133 * @to: mem_cgroup which the entry is moved to
4135 * It succeeds only when the swap_cgroup's record for this entry is the same
4136 * as the mem_cgroup's id of @from.
4138 * Returns 0 on success, -EINVAL on failure.
4140 * The caller must have charged to @to, IOW, called res_counter_charge() about
4141 * both res and memsw, and called css_get().
4143 static int mem_cgroup_move_swap_account(swp_entry_t entry,
4144 struct mem_cgroup *from, struct mem_cgroup *to)
4146 unsigned short old_id, new_id;
4148 old_id = css_id(&from->css);
4149 new_id = css_id(&to->css);
4151 if (swap_cgroup_cmpxchg(entry, old_id, new_id) == old_id) {
4152 mem_cgroup_swap_statistics(from, false);
4153 mem_cgroup_swap_statistics(to, true);
4155 * This function is only called from task migration context now.
4156 * It postpones res_counter and refcount handling till the end
4157 * of task migration(mem_cgroup_clear_mc()) for performance
4158 * improvement. But we cannot postpone css_get(to) because if
4159 * the process that has been moved to @to does swap-in, the
4160 * refcount of @to might be decreased to 0.
4162 * We are in attach() phase, so the cgroup is guaranteed to be
4163 * alive, so we can just call css_get().
4171 static inline int mem_cgroup_move_swap_account(swp_entry_t entry,
4172 struct mem_cgroup *from, struct mem_cgroup *to)
4179 * Before starting migration, account PAGE_SIZE to mem_cgroup that the old
4182 void mem_cgroup_prepare_migration(struct page *page, struct page *newpage,
4183 struct mem_cgroup **memcgp)
4185 struct mem_cgroup *memcg = NULL;
4186 unsigned int nr_pages = 1;
4187 struct page_cgroup *pc;
4188 enum charge_type ctype;
4192 if (mem_cgroup_disabled())
4195 if (PageTransHuge(page))
4196 nr_pages <<= compound_order(page);
4198 pc = lookup_page_cgroup(page);
4199 lock_page_cgroup(pc);
4200 if (PageCgroupUsed(pc)) {
4201 memcg = pc->mem_cgroup;
4202 css_get(&memcg->css);
4204 * At migrating an anonymous page, its mapcount goes down
4205 * to 0 and uncharge() will be called. But, even if it's fully
4206 * unmapped, migration may fail and this page has to be
4207 * charged again. We set MIGRATION flag here and delay uncharge
4208 * until end_migration() is called
4210 * Corner Case Thinking
4212 * When the old page was mapped as Anon and it's unmap-and-freed
4213 * while migration was ongoing.
4214 * If unmap finds the old page, uncharge() of it will be delayed
4215 * until end_migration(). If unmap finds a new page, it's
4216 * uncharged when it make mapcount to be 1->0. If unmap code
4217 * finds swap_migration_entry, the new page will not be mapped
4218 * and end_migration() will find it(mapcount==0).
4221 * When the old page was mapped but migraion fails, the kernel
4222 * remaps it. A charge for it is kept by MIGRATION flag even
4223 * if mapcount goes down to 0. We can do remap successfully
4224 * without charging it again.
4227 * The "old" page is under lock_page() until the end of
4228 * migration, so, the old page itself will not be swapped-out.
4229 * If the new page is swapped out before end_migraton, our
4230 * hook to usual swap-out path will catch the event.
4233 SetPageCgroupMigration(pc);
4235 unlock_page_cgroup(pc);
4237 * If the page is not charged at this point,
4245 * We charge new page before it's used/mapped. So, even if unlock_page()
4246 * is called before end_migration, we can catch all events on this new
4247 * page. In the case new page is migrated but not remapped, new page's
4248 * mapcount will be finally 0 and we call uncharge in end_migration().
4251 ctype = MEM_CGROUP_CHARGE_TYPE_ANON;
4253 ctype = MEM_CGROUP_CHARGE_TYPE_CACHE;
4255 * The page is committed to the memcg, but it's not actually
4256 * charged to the res_counter since we plan on replacing the
4257 * old one and only one page is going to be left afterwards.
4259 __mem_cgroup_commit_charge(memcg, newpage, nr_pages, ctype, false);
4262 /* remove redundant charge if migration failed*/
4263 void mem_cgroup_end_migration(struct mem_cgroup *memcg,
4264 struct page *oldpage, struct page *newpage, bool migration_ok)
4266 struct page *used, *unused;
4267 struct page_cgroup *pc;
4273 if (!migration_ok) {
4280 anon = PageAnon(used);
4281 __mem_cgroup_uncharge_common(unused,
4282 anon ? MEM_CGROUP_CHARGE_TYPE_ANON
4283 : MEM_CGROUP_CHARGE_TYPE_CACHE,
4285 css_put(&memcg->css);
4287 * We disallowed uncharge of pages under migration because mapcount
4288 * of the page goes down to zero, temporarly.
4289 * Clear the flag and check the page should be charged.
4291 pc = lookup_page_cgroup(oldpage);
4292 lock_page_cgroup(pc);
4293 ClearPageCgroupMigration(pc);
4294 unlock_page_cgroup(pc);
4297 * If a page is a file cache, radix-tree replacement is very atomic
4298 * and we can skip this check. When it was an Anon page, its mapcount
4299 * goes down to 0. But because we added MIGRATION flage, it's not
4300 * uncharged yet. There are several case but page->mapcount check
4301 * and USED bit check in mem_cgroup_uncharge_page() will do enough
4302 * check. (see prepare_charge() also)
4305 mem_cgroup_uncharge_page(used);
4309 * At replace page cache, newpage is not under any memcg but it's on
4310 * LRU. So, this function doesn't touch res_counter but handles LRU
4311 * in correct way. Both pages are locked so we cannot race with uncharge.
4313 void mem_cgroup_replace_page_cache(struct page *oldpage,
4314 struct page *newpage)
4316 struct mem_cgroup *memcg = NULL;
4317 struct page_cgroup *pc;
4318 enum charge_type type = MEM_CGROUP_CHARGE_TYPE_CACHE;
4320 if (mem_cgroup_disabled())
4323 pc = lookup_page_cgroup(oldpage);
4324 /* fix accounting on old pages */
4325 lock_page_cgroup(pc);
4326 if (PageCgroupUsed(pc)) {
4327 memcg = pc->mem_cgroup;
4328 mem_cgroup_charge_statistics(memcg, oldpage, false, -1);
4329 ClearPageCgroupUsed(pc);
4331 unlock_page_cgroup(pc);
4334 * When called from shmem_replace_page(), in some cases the
4335 * oldpage has already been charged, and in some cases not.
4340 * Even if newpage->mapping was NULL before starting replacement,
4341 * the newpage may be on LRU(or pagevec for LRU) already. We lock
4342 * LRU while we overwrite pc->mem_cgroup.
4344 __mem_cgroup_commit_charge(memcg, newpage, 1, type, true);
4347 #ifdef CONFIG_DEBUG_VM
4348 static struct page_cgroup *lookup_page_cgroup_used(struct page *page)
4350 struct page_cgroup *pc;
4352 pc = lookup_page_cgroup(page);
4354 * Can be NULL while feeding pages into the page allocator for
4355 * the first time, i.e. during boot or memory hotplug;
4356 * or when mem_cgroup_disabled().
4358 if (likely(pc) && PageCgroupUsed(pc))
4363 bool mem_cgroup_bad_page_check(struct page *page)
4365 if (mem_cgroup_disabled())
4368 return lookup_page_cgroup_used(page) != NULL;
4371 void mem_cgroup_print_bad_page(struct page *page)
4373 struct page_cgroup *pc;
4375 pc = lookup_page_cgroup_used(page);
4377 pr_alert("pc:%p pc->flags:%lx pc->mem_cgroup:%p\n",
4378 pc, pc->flags, pc->mem_cgroup);
4383 static int mem_cgroup_resize_limit(struct mem_cgroup *memcg,
4384 unsigned long long val)
4387 u64 memswlimit, memlimit;
4389 int children = mem_cgroup_count_children(memcg);
4390 u64 curusage, oldusage;
4394 * For keeping hierarchical_reclaim simple, how long we should retry
4395 * is depends on callers. We set our retry-count to be function
4396 * of # of children which we should visit in this loop.
4398 retry_count = MEM_CGROUP_RECLAIM_RETRIES * children;
4400 oldusage = res_counter_read_u64(&memcg->res, RES_USAGE);
4403 while (retry_count) {
4404 if (signal_pending(current)) {
4409 * Rather than hide all in some function, I do this in
4410 * open coded manner. You see what this really does.
4411 * We have to guarantee memcg->res.limit <= memcg->memsw.limit.
4413 mutex_lock(&set_limit_mutex);
4414 memswlimit = res_counter_read_u64(&memcg->memsw, RES_LIMIT);
4415 if (memswlimit < val) {
4417 mutex_unlock(&set_limit_mutex);
4421 memlimit = res_counter_read_u64(&memcg->res, RES_LIMIT);
4425 ret = res_counter_set_limit(&memcg->res, val);
4427 if (memswlimit == val)
4428 memcg->memsw_is_minimum = true;
4430 memcg->memsw_is_minimum = false;
4432 mutex_unlock(&set_limit_mutex);
4437 mem_cgroup_reclaim(memcg, GFP_KERNEL,
4438 MEM_CGROUP_RECLAIM_SHRINK);
4439 curusage = res_counter_read_u64(&memcg->res, RES_USAGE);
4440 /* Usage is reduced ? */
4441 if (curusage >= oldusage)
4444 oldusage = curusage;
4446 if (!ret && enlarge)
4447 memcg_oom_recover(memcg);
4452 static int mem_cgroup_resize_memsw_limit(struct mem_cgroup *memcg,
4453 unsigned long long val)
4456 u64 memlimit, memswlimit, oldusage, curusage;
4457 int children = mem_cgroup_count_children(memcg);
4461 /* see mem_cgroup_resize_res_limit */
4462 retry_count = children * MEM_CGROUP_RECLAIM_RETRIES;
4463 oldusage = res_counter_read_u64(&memcg->memsw, RES_USAGE);
4464 while (retry_count) {
4465 if (signal_pending(current)) {
4470 * Rather than hide all in some function, I do this in
4471 * open coded manner. You see what this really does.
4472 * We have to guarantee memcg->res.limit <= memcg->memsw.limit.
4474 mutex_lock(&set_limit_mutex);
4475 memlimit = res_counter_read_u64(&memcg->res, RES_LIMIT);
4476 if (memlimit > val) {
4478 mutex_unlock(&set_limit_mutex);
4481 memswlimit = res_counter_read_u64(&memcg->memsw, RES_LIMIT);
4482 if (memswlimit < val)
4484 ret = res_counter_set_limit(&memcg->memsw, val);
4486 if (memlimit == val)
4487 memcg->memsw_is_minimum = true;
4489 memcg->memsw_is_minimum = false;
4491 mutex_unlock(&set_limit_mutex);
4496 mem_cgroup_reclaim(memcg, GFP_KERNEL,
4497 MEM_CGROUP_RECLAIM_NOSWAP |
4498 MEM_CGROUP_RECLAIM_SHRINK);
4499 curusage = res_counter_read_u64(&memcg->memsw, RES_USAGE);
4500 /* Usage is reduced ? */
4501 if (curusage >= oldusage)
4504 oldusage = curusage;
4506 if (!ret && enlarge)
4507 memcg_oom_recover(memcg);
4512 * mem_cgroup_force_empty_list - clears LRU of a group
4513 * @memcg: group to clear
4516 * @lru: lru to to clear
4518 * Traverse a specified page_cgroup list and try to drop them all. This doesn't
4519 * reclaim the pages page themselves - pages are moved to the parent (or root)
4522 static void mem_cgroup_force_empty_list(struct mem_cgroup *memcg,
4523 int node, int zid, enum lru_list lru)
4525 struct lruvec *lruvec;
4526 unsigned long flags;
4527 struct list_head *list;
4531 zone = &NODE_DATA(node)->node_zones[zid];
4532 lruvec = mem_cgroup_zone_lruvec(zone, memcg);
4533 list = &lruvec->lists[lru];
4537 struct page_cgroup *pc;
4540 spin_lock_irqsave(&zone->lru_lock, flags);
4541 if (list_empty(list)) {
4542 spin_unlock_irqrestore(&zone->lru_lock, flags);
4545 page = list_entry(list->prev, struct page, lru);
4547 list_move(&page->lru, list);
4549 spin_unlock_irqrestore(&zone->lru_lock, flags);
4552 spin_unlock_irqrestore(&zone->lru_lock, flags);
4554 pc = lookup_page_cgroup(page);
4556 if (mem_cgroup_move_parent(page, pc, memcg)) {
4557 /* found lock contention or "pc" is obsolete. */
4562 } while (!list_empty(list));
4566 * make mem_cgroup's charge to be 0 if there is no task by moving
4567 * all the charges and pages to the parent.
4568 * This enables deleting this mem_cgroup.
4570 * Caller is responsible for holding css reference on the memcg.
4572 static void mem_cgroup_reparent_charges(struct mem_cgroup *memcg)
4578 /* This is for making all *used* pages to be on LRU. */
4579 lru_add_drain_all();
4580 drain_all_stock_sync(memcg);
4581 mem_cgroup_start_move(memcg);
4582 for_each_node_state(node, N_MEMORY) {
4583 for (zid = 0; zid < MAX_NR_ZONES; zid++) {
4586 mem_cgroup_force_empty_list(memcg,
4591 mem_cgroup_end_move(memcg);
4592 memcg_oom_recover(memcg);
4596 * Kernel memory may not necessarily be trackable to a specific
4597 * process. So they are not migrated, and therefore we can't
4598 * expect their value to drop to 0 here.
4599 * Having res filled up with kmem only is enough.
4601 * This is a safety check because mem_cgroup_force_empty_list
4602 * could have raced with mem_cgroup_replace_page_cache callers
4603 * so the lru seemed empty but the page could have been added
4604 * right after the check. RES_USAGE should be safe as we always
4605 * charge before adding to the LRU.
4607 usage = res_counter_read_u64(&memcg->res, RES_USAGE) -
4608 res_counter_read_u64(&memcg->kmem, RES_USAGE);
4609 } while (usage > 0);
4613 * This mainly exists for tests during the setting of set of use_hierarchy.
4614 * Since this is the very setting we are changing, the current hierarchy value
4617 static inline bool __memcg_has_children(struct mem_cgroup *memcg)
4619 struct cgroup_subsys_state *pos;
4621 /* bounce at first found */
4622 css_for_each_child(pos, &memcg->css)
4628 * Must be called with memcg_create_mutex held, unless the cgroup is guaranteed
4629 * to be already dead (as in mem_cgroup_force_empty, for instance). This is
4630 * from mem_cgroup_count_children(), in the sense that we don't really care how
4631 * many children we have; we only need to know if we have any. It also counts
4632 * any memcg without hierarchy as infertile.
4634 static inline bool memcg_has_children(struct mem_cgroup *memcg)
4636 return memcg->use_hierarchy && __memcg_has_children(memcg);
4640 * Reclaims as many pages from the given memcg as possible and moves
4641 * the rest to the parent.
4643 * Caller is responsible for holding css reference for memcg.
4645 static int mem_cgroup_force_empty(struct mem_cgroup *memcg)
4647 int nr_retries = MEM_CGROUP_RECLAIM_RETRIES;
4648 struct cgroup *cgrp = memcg->css.cgroup;
4650 /* returns EBUSY if there is a task or if we come here twice. */
4651 if (cgroup_task_count(cgrp) || !list_empty(&cgrp->children))
4654 /* we call try-to-free pages for make this cgroup empty */
4655 lru_add_drain_all();
4656 /* try to free all pages in this cgroup */
4657 while (nr_retries && res_counter_read_u64(&memcg->res, RES_USAGE) > 0) {
4660 if (signal_pending(current))
4663 progress = try_to_free_mem_cgroup_pages(memcg, GFP_KERNEL,
4667 /* maybe some writeback is necessary */
4668 congestion_wait(BLK_RW_ASYNC, HZ/10);
4673 mem_cgroup_reparent_charges(memcg);
4678 static int mem_cgroup_force_empty_write(struct cgroup_subsys_state *css,
4681 struct mem_cgroup *memcg = mem_cgroup_from_css(css);
4683 if (mem_cgroup_is_root(memcg))
4685 return mem_cgroup_force_empty(memcg);
4688 static u64 mem_cgroup_hierarchy_read(struct cgroup_subsys_state *css,
4691 return mem_cgroup_from_css(css)->use_hierarchy;
4694 static int mem_cgroup_hierarchy_write(struct cgroup_subsys_state *css,
4695 struct cftype *cft, u64 val)
4698 struct mem_cgroup *memcg = mem_cgroup_from_css(css);
4699 struct mem_cgroup *parent_memcg = mem_cgroup_from_css(css_parent(&memcg->css));
4701 mutex_lock(&memcg_create_mutex);
4703 if (memcg->use_hierarchy == val)
4707 * If parent's use_hierarchy is set, we can't make any modifications
4708 * in the child subtrees. If it is unset, then the change can
4709 * occur, provided the current cgroup has no children.
4711 * For the root cgroup, parent_mem is NULL, we allow value to be
4712 * set if there are no children.
4714 if ((!parent_memcg || !parent_memcg->use_hierarchy) &&
4715 (val == 1 || val == 0)) {
4716 if (!__memcg_has_children(memcg))
4717 memcg->use_hierarchy = val;
4724 mutex_unlock(&memcg_create_mutex);
4730 static unsigned long mem_cgroup_recursive_stat(struct mem_cgroup *memcg,
4731 enum mem_cgroup_stat_index idx)
4733 struct mem_cgroup *iter;
4736 /* Per-cpu values can be negative, use a signed accumulator */
4737 for_each_mem_cgroup_tree(iter, memcg)
4738 val += mem_cgroup_read_stat(iter, idx);
4740 if (val < 0) /* race ? */
4745 static inline u64 mem_cgroup_usage(struct mem_cgroup *memcg, bool swap)
4749 if (!mem_cgroup_is_root(memcg)) {
4751 return res_counter_read_u64(&memcg->res, RES_USAGE);
4753 return res_counter_read_u64(&memcg->memsw, RES_USAGE);
4757 * Transparent hugepages are still accounted for in MEM_CGROUP_STAT_RSS
4758 * as well as in MEM_CGROUP_STAT_RSS_HUGE.
4760 val = mem_cgroup_recursive_stat(memcg, MEM_CGROUP_STAT_CACHE);
4761 val += mem_cgroup_recursive_stat(memcg, MEM_CGROUP_STAT_RSS);
4764 val += mem_cgroup_recursive_stat(memcg, MEM_CGROUP_STAT_SWAP);
4766 return val << PAGE_SHIFT;
4769 static ssize_t mem_cgroup_read(struct cgroup_subsys_state *css,
4770 struct cftype *cft, struct file *file,
4771 char __user *buf, size_t nbytes, loff_t *ppos)
4773 struct mem_cgroup *memcg = mem_cgroup_from_css(css);
4779 type = MEMFILE_TYPE(cft->private);
4780 name = MEMFILE_ATTR(cft->private);
4784 if (name == RES_USAGE)
4785 val = mem_cgroup_usage(memcg, false);
4787 val = res_counter_read_u64(&memcg->res, name);
4790 if (name == RES_USAGE)
4791 val = mem_cgroup_usage(memcg, true);
4793 val = res_counter_read_u64(&memcg->memsw, name);
4796 val = res_counter_read_u64(&memcg->kmem, name);
4802 len = scnprintf(str, sizeof(str), "%llu\n", (unsigned long long)val);
4803 return simple_read_from_buffer(buf, nbytes, ppos, str, len);
4806 static int memcg_update_kmem_limit(struct cgroup_subsys_state *css, u64 val)
4809 #ifdef CONFIG_MEMCG_KMEM
4810 struct mem_cgroup *memcg = mem_cgroup_from_css(css);
4812 * For simplicity, we won't allow this to be disabled. It also can't
4813 * be changed if the cgroup has children already, or if tasks had
4816 * If tasks join before we set the limit, a person looking at
4817 * kmem.usage_in_bytes will have no way to determine when it took
4818 * place, which makes the value quite meaningless.
4820 * After it first became limited, changes in the value of the limit are
4821 * of course permitted.
4823 mutex_lock(&memcg_create_mutex);
4824 mutex_lock(&set_limit_mutex);
4825 if (!memcg->kmem_account_flags && val != RESOURCE_MAX) {
4826 if (cgroup_task_count(css->cgroup) || memcg_has_children(memcg)) {
4830 ret = res_counter_set_limit(&memcg->kmem, val);
4833 ret = memcg_update_cache_sizes(memcg);
4835 res_counter_set_limit(&memcg->kmem, RESOURCE_MAX);
4838 static_key_slow_inc(&memcg_kmem_enabled_key);
4840 * setting the active bit after the inc will guarantee no one
4841 * starts accounting before all call sites are patched
4843 memcg_kmem_set_active(memcg);
4845 ret = res_counter_set_limit(&memcg->kmem, val);
4847 mutex_unlock(&set_limit_mutex);
4848 mutex_unlock(&memcg_create_mutex);
4853 #ifdef CONFIG_MEMCG_KMEM
4854 static int memcg_propagate_kmem(struct mem_cgroup *memcg)
4857 struct mem_cgroup *parent = parent_mem_cgroup(memcg);
4861 memcg->kmem_account_flags = parent->kmem_account_flags;
4863 * When that happen, we need to disable the static branch only on those
4864 * memcgs that enabled it. To achieve this, we would be forced to
4865 * complicate the code by keeping track of which memcgs were the ones
4866 * that actually enabled limits, and which ones got it from its
4869 * It is a lot simpler just to do static_key_slow_inc() on every child
4870 * that is accounted.
4872 if (!memcg_kmem_is_active(memcg))
4876 * __mem_cgroup_free() will issue static_key_slow_dec() because this
4877 * memcg is active already. If the later initialization fails then the
4878 * cgroup core triggers the cleanup so we do not have to do it here.
4880 static_key_slow_inc(&memcg_kmem_enabled_key);
4882 mutex_lock(&set_limit_mutex);
4883 memcg_stop_kmem_account();
4884 ret = memcg_update_cache_sizes(memcg);
4885 memcg_resume_kmem_account();
4886 mutex_unlock(&set_limit_mutex);
4890 #endif /* CONFIG_MEMCG_KMEM */
4893 * The user of this function is...
4896 static int mem_cgroup_write(struct cgroup_subsys_state *css, struct cftype *cft,
4899 struct mem_cgroup *memcg = mem_cgroup_from_css(css);
4902 unsigned long long val;
4905 type = MEMFILE_TYPE(cft->private);
4906 name = MEMFILE_ATTR(cft->private);
4910 if (mem_cgroup_is_root(memcg)) { /* Can't set limit on root */
4914 /* This function does all necessary parse...reuse it */
4915 ret = res_counter_memparse_write_strategy(buffer, &val);
4919 ret = mem_cgroup_resize_limit(memcg, val);
4920 else if (type == _MEMSWAP)
4921 ret = mem_cgroup_resize_memsw_limit(memcg, val);
4922 else if (type == _KMEM)
4923 ret = memcg_update_kmem_limit(css, val);
4927 case RES_SOFT_LIMIT:
4928 ret = res_counter_memparse_write_strategy(buffer, &val);
4932 * For memsw, soft limits are hard to implement in terms
4933 * of semantics, for now, we support soft limits for
4934 * control without swap
4937 ret = res_counter_set_soft_limit(&memcg->res, val);
4942 ret = -EINVAL; /* should be BUG() ? */
4948 static void memcg_get_hierarchical_limit(struct mem_cgroup *memcg,
4949 unsigned long long *mem_limit, unsigned long long *memsw_limit)
4951 unsigned long long min_limit, min_memsw_limit, tmp;
4953 min_limit = res_counter_read_u64(&memcg->res, RES_LIMIT);
4954 min_memsw_limit = res_counter_read_u64(&memcg->memsw, RES_LIMIT);
4955 if (!memcg->use_hierarchy)
4958 while (css_parent(&memcg->css)) {
4959 memcg = mem_cgroup_from_css(css_parent(&memcg->css));
4960 if (!memcg->use_hierarchy)
4962 tmp = res_counter_read_u64(&memcg->res, RES_LIMIT);
4963 min_limit = min(min_limit, tmp);
4964 tmp = res_counter_read_u64(&memcg->memsw, RES_LIMIT);
4965 min_memsw_limit = min(min_memsw_limit, tmp);
4968 *mem_limit = min_limit;
4969 *memsw_limit = min_memsw_limit;
4972 static int mem_cgroup_reset(struct cgroup_subsys_state *css, unsigned int event)
4974 struct mem_cgroup *memcg = mem_cgroup_from_css(css);
4978 type = MEMFILE_TYPE(event);
4979 name = MEMFILE_ATTR(event);
4984 res_counter_reset_max(&memcg->res);
4985 else if (type == _MEMSWAP)
4986 res_counter_reset_max(&memcg->memsw);
4987 else if (type == _KMEM)
4988 res_counter_reset_max(&memcg->kmem);
4994 res_counter_reset_failcnt(&memcg->res);
4995 else if (type == _MEMSWAP)
4996 res_counter_reset_failcnt(&memcg->memsw);
4997 else if (type == _KMEM)
4998 res_counter_reset_failcnt(&memcg->kmem);
5007 static u64 mem_cgroup_move_charge_read(struct cgroup_subsys_state *css,
5010 return mem_cgroup_from_css(css)->move_charge_at_immigrate;
5014 static int mem_cgroup_move_charge_write(struct cgroup_subsys_state *css,
5015 struct cftype *cft, u64 val)
5017 struct mem_cgroup *memcg = mem_cgroup_from_css(css);
5019 if (val >= (1 << NR_MOVE_TYPE))
5023 * No kind of locking is needed in here, because ->can_attach() will
5024 * check this value once in the beginning of the process, and then carry
5025 * on with stale data. This means that changes to this value will only
5026 * affect task migrations starting after the change.
5028 memcg->move_charge_at_immigrate = val;
5032 static int mem_cgroup_move_charge_write(struct cgroup_subsys_state *css,
5033 struct cftype *cft, u64 val)
5040 static int memcg_numa_stat_show(struct cgroup_subsys_state *css,
5041 struct cftype *cft, struct seq_file *m)
5044 unsigned long total_nr, file_nr, anon_nr, unevictable_nr;
5045 unsigned long node_nr;
5046 struct mem_cgroup *memcg = mem_cgroup_from_css(css);
5048 total_nr = mem_cgroup_nr_lru_pages(memcg, LRU_ALL);
5049 seq_printf(m, "total=%lu", total_nr);
5050 for_each_node_state(nid, N_MEMORY) {
5051 node_nr = mem_cgroup_node_nr_lru_pages(memcg, nid, LRU_ALL);
5052 seq_printf(m, " N%d=%lu", nid, node_nr);
5056 file_nr = mem_cgroup_nr_lru_pages(memcg, LRU_ALL_FILE);
5057 seq_printf(m, "file=%lu", file_nr);
5058 for_each_node_state(nid, N_MEMORY) {
5059 node_nr = mem_cgroup_node_nr_lru_pages(memcg, nid,
5061 seq_printf(m, " N%d=%lu", nid, node_nr);
5065 anon_nr = mem_cgroup_nr_lru_pages(memcg, LRU_ALL_ANON);
5066 seq_printf(m, "anon=%lu", anon_nr);
5067 for_each_node_state(nid, N_MEMORY) {
5068 node_nr = mem_cgroup_node_nr_lru_pages(memcg, nid,
5070 seq_printf(m, " N%d=%lu", nid, node_nr);
5074 unevictable_nr = mem_cgroup_nr_lru_pages(memcg, BIT(LRU_UNEVICTABLE));
5075 seq_printf(m, "unevictable=%lu", unevictable_nr);
5076 for_each_node_state(nid, N_MEMORY) {
5077 node_nr = mem_cgroup_node_nr_lru_pages(memcg, nid,
5078 BIT(LRU_UNEVICTABLE));
5079 seq_printf(m, " N%d=%lu", nid, node_nr);
5084 #endif /* CONFIG_NUMA */
5086 static inline void mem_cgroup_lru_names_not_uptodate(void)
5088 BUILD_BUG_ON(ARRAY_SIZE(mem_cgroup_lru_names) != NR_LRU_LISTS);
5091 static int memcg_stat_show(struct cgroup_subsys_state *css, struct cftype *cft,
5094 struct mem_cgroup *memcg = mem_cgroup_from_css(css);
5095 struct mem_cgroup *mi;
5098 for (i = 0; i < MEM_CGROUP_STAT_NSTATS; i++) {
5099 if (i == MEM_CGROUP_STAT_SWAP && !do_swap_account)
5101 seq_printf(m, "%s %ld\n", mem_cgroup_stat_names[i],
5102 mem_cgroup_read_stat(memcg, i) * PAGE_SIZE);
5105 for (i = 0; i < MEM_CGROUP_EVENTS_NSTATS; i++)
5106 seq_printf(m, "%s %lu\n", mem_cgroup_events_names[i],
5107 mem_cgroup_read_events(memcg, i));
5109 for (i = 0; i < NR_LRU_LISTS; i++)
5110 seq_printf(m, "%s %lu\n", mem_cgroup_lru_names[i],
5111 mem_cgroup_nr_lru_pages(memcg, BIT(i)) * PAGE_SIZE);
5113 /* Hierarchical information */
5115 unsigned long long limit, memsw_limit;
5116 memcg_get_hierarchical_limit(memcg, &limit, &memsw_limit);
5117 seq_printf(m, "hierarchical_memory_limit %llu\n", limit);
5118 if (do_swap_account)
5119 seq_printf(m, "hierarchical_memsw_limit %llu\n",
5123 for (i = 0; i < MEM_CGROUP_STAT_NSTATS; i++) {
5126 if (i == MEM_CGROUP_STAT_SWAP && !do_swap_account)
5128 for_each_mem_cgroup_tree(mi, memcg)
5129 val += mem_cgroup_read_stat(mi, i) * PAGE_SIZE;
5130 seq_printf(m, "total_%s %lld\n", mem_cgroup_stat_names[i], val);
5133 for (i = 0; i < MEM_CGROUP_EVENTS_NSTATS; i++) {
5134 unsigned long long val = 0;
5136 for_each_mem_cgroup_tree(mi, memcg)
5137 val += mem_cgroup_read_events(mi, i);
5138 seq_printf(m, "total_%s %llu\n",
5139 mem_cgroup_events_names[i], val);
5142 for (i = 0; i < NR_LRU_LISTS; i++) {
5143 unsigned long long val = 0;
5145 for_each_mem_cgroup_tree(mi, memcg)
5146 val += mem_cgroup_nr_lru_pages(mi, BIT(i)) * PAGE_SIZE;
5147 seq_printf(m, "total_%s %llu\n", mem_cgroup_lru_names[i], val);
5150 #ifdef CONFIG_DEBUG_VM
5153 struct mem_cgroup_per_zone *mz;
5154 struct zone_reclaim_stat *rstat;
5155 unsigned long recent_rotated[2] = {0, 0};
5156 unsigned long recent_scanned[2] = {0, 0};
5158 for_each_online_node(nid)
5159 for (zid = 0; zid < MAX_NR_ZONES; zid++) {
5160 mz = mem_cgroup_zoneinfo(memcg, nid, zid);
5161 rstat = &mz->lruvec.reclaim_stat;
5163 recent_rotated[0] += rstat->recent_rotated[0];
5164 recent_rotated[1] += rstat->recent_rotated[1];
5165 recent_scanned[0] += rstat->recent_scanned[0];
5166 recent_scanned[1] += rstat->recent_scanned[1];
5168 seq_printf(m, "recent_rotated_anon %lu\n", recent_rotated[0]);
5169 seq_printf(m, "recent_rotated_file %lu\n", recent_rotated[1]);
5170 seq_printf(m, "recent_scanned_anon %lu\n", recent_scanned[0]);
5171 seq_printf(m, "recent_scanned_file %lu\n", recent_scanned[1]);
5178 static u64 mem_cgroup_swappiness_read(struct cgroup_subsys_state *css,
5181 struct mem_cgroup *memcg = mem_cgroup_from_css(css);
5183 return mem_cgroup_swappiness(memcg);
5186 static int mem_cgroup_swappiness_write(struct cgroup_subsys_state *css,
5187 struct cftype *cft, u64 val)
5189 struct mem_cgroup *memcg = mem_cgroup_from_css(css);
5190 struct mem_cgroup *parent = mem_cgroup_from_css(css_parent(&memcg->css));
5192 if (val > 100 || !parent)
5195 mutex_lock(&memcg_create_mutex);
5197 /* If under hierarchy, only empty-root can set this value */
5198 if ((parent->use_hierarchy) || memcg_has_children(memcg)) {
5199 mutex_unlock(&memcg_create_mutex);
5203 memcg->swappiness = val;
5205 mutex_unlock(&memcg_create_mutex);
5210 static void __mem_cgroup_threshold(struct mem_cgroup *memcg, bool swap)
5212 struct mem_cgroup_threshold_ary *t;
5218 t = rcu_dereference(memcg->thresholds.primary);
5220 t = rcu_dereference(memcg->memsw_thresholds.primary);
5225 usage = mem_cgroup_usage(memcg, swap);
5228 * current_threshold points to threshold just below or equal to usage.
5229 * If it's not true, a threshold was crossed after last
5230 * call of __mem_cgroup_threshold().
5232 i = t->current_threshold;
5235 * Iterate backward over array of thresholds starting from
5236 * current_threshold and check if a threshold is crossed.
5237 * If none of thresholds below usage is crossed, we read
5238 * only one element of the array here.
5240 for (; i >= 0 && unlikely(t->entries[i].threshold > usage); i--)
5241 eventfd_signal(t->entries[i].eventfd, 1);
5243 /* i = current_threshold + 1 */
5247 * Iterate forward over array of thresholds starting from
5248 * current_threshold+1 and check if a threshold is crossed.
5249 * If none of thresholds above usage is crossed, we read
5250 * only one element of the array here.
5252 for (; i < t->size && unlikely(t->entries[i].threshold <= usage); i++)
5253 eventfd_signal(t->entries[i].eventfd, 1);
5255 /* Update current_threshold */
5256 t->current_threshold = i - 1;
5261 static void mem_cgroup_threshold(struct mem_cgroup *memcg)
5264 __mem_cgroup_threshold(memcg, false);
5265 if (do_swap_account)
5266 __mem_cgroup_threshold(memcg, true);
5268 memcg = parent_mem_cgroup(memcg);
5272 static int compare_thresholds(const void *a, const void *b)
5274 const struct mem_cgroup_threshold *_a = a;
5275 const struct mem_cgroup_threshold *_b = b;
5277 if (_a->threshold > _b->threshold)
5280 if (_a->threshold < _b->threshold)
5286 static int mem_cgroup_oom_notify_cb(struct mem_cgroup *memcg)
5288 struct mem_cgroup_eventfd_list *ev;
5290 list_for_each_entry(ev, &memcg->oom_notify, list)
5291 eventfd_signal(ev->eventfd, 1);
5295 static void mem_cgroup_oom_notify(struct mem_cgroup *memcg)
5297 struct mem_cgroup *iter;
5299 for_each_mem_cgroup_tree(iter, memcg)
5300 mem_cgroup_oom_notify_cb(iter);
5303 static int mem_cgroup_usage_register_event(struct cgroup_subsys_state *css,
5304 struct cftype *cft, struct eventfd_ctx *eventfd, const char *args)
5306 struct mem_cgroup *memcg = mem_cgroup_from_css(css);
5307 struct mem_cgroup_thresholds *thresholds;
5308 struct mem_cgroup_threshold_ary *new;
5309 enum res_type type = MEMFILE_TYPE(cft->private);
5310 u64 threshold, usage;
5313 ret = res_counter_memparse_write_strategy(args, &threshold);
5317 mutex_lock(&memcg->thresholds_lock);
5320 thresholds = &memcg->thresholds;
5321 else if (type == _MEMSWAP)
5322 thresholds = &memcg->memsw_thresholds;
5326 usage = mem_cgroup_usage(memcg, type == _MEMSWAP);
5328 /* Check if a threshold crossed before adding a new one */
5329 if (thresholds->primary)
5330 __mem_cgroup_threshold(memcg, type == _MEMSWAP);
5332 size = thresholds->primary ? thresholds->primary->size + 1 : 1;
5334 /* Allocate memory for new array of thresholds */
5335 new = kmalloc(sizeof(*new) + size * sizeof(struct mem_cgroup_threshold),
5343 /* Copy thresholds (if any) to new array */
5344 if (thresholds->primary) {
5345 memcpy(new->entries, thresholds->primary->entries, (size - 1) *
5346 sizeof(struct mem_cgroup_threshold));
5349 /* Add new threshold */
5350 new->entries[size - 1].eventfd = eventfd;
5351 new->entries[size - 1].threshold = threshold;
5353 /* Sort thresholds. Registering of new threshold isn't time-critical */
5354 sort(new->entries, size, sizeof(struct mem_cgroup_threshold),
5355 compare_thresholds, NULL);
5357 /* Find current threshold */
5358 new->current_threshold = -1;
5359 for (i = 0; i < size; i++) {
5360 if (new->entries[i].threshold <= usage) {
5362 * new->current_threshold will not be used until
5363 * rcu_assign_pointer(), so it's safe to increment
5366 ++new->current_threshold;
5371 /* Free old spare buffer and save old primary buffer as spare */
5372 kfree(thresholds->spare);
5373 thresholds->spare = thresholds->primary;
5375 rcu_assign_pointer(thresholds->primary, new);
5377 /* To be sure that nobody uses thresholds */
5381 mutex_unlock(&memcg->thresholds_lock);
5386 static void mem_cgroup_usage_unregister_event(struct cgroup_subsys_state *css,
5387 struct cftype *cft, struct eventfd_ctx *eventfd)
5389 struct mem_cgroup *memcg = mem_cgroup_from_css(css);
5390 struct mem_cgroup_thresholds *thresholds;
5391 struct mem_cgroup_threshold_ary *new;
5392 enum res_type type = MEMFILE_TYPE(cft->private);
5396 mutex_lock(&memcg->thresholds_lock);
5398 thresholds = &memcg->thresholds;
5399 else if (type == _MEMSWAP)
5400 thresholds = &memcg->memsw_thresholds;
5404 if (!thresholds->primary)
5407 usage = mem_cgroup_usage(memcg, type == _MEMSWAP);
5409 /* Check if a threshold crossed before removing */
5410 __mem_cgroup_threshold(memcg, type == _MEMSWAP);
5412 /* Calculate new number of threshold */
5414 for (i = 0; i < thresholds->primary->size; i++) {
5415 if (thresholds->primary->entries[i].eventfd != eventfd)
5419 new = thresholds->spare;
5421 /* Set thresholds array to NULL if we don't have thresholds */
5430 /* Copy thresholds and find current threshold */
5431 new->current_threshold = -1;
5432 for (i = 0, j = 0; i < thresholds->primary->size; i++) {
5433 if (thresholds->primary->entries[i].eventfd == eventfd)
5436 new->entries[j] = thresholds->primary->entries[i];
5437 if (new->entries[j].threshold <= usage) {
5439 * new->current_threshold will not be used
5440 * until rcu_assign_pointer(), so it's safe to increment
5443 ++new->current_threshold;
5449 /* Swap primary and spare array */
5450 thresholds->spare = thresholds->primary;
5451 /* If all events are unregistered, free the spare array */
5453 kfree(thresholds->spare);
5454 thresholds->spare = NULL;
5457 rcu_assign_pointer(thresholds->primary, new);
5459 /* To be sure that nobody uses thresholds */
5462 mutex_unlock(&memcg->thresholds_lock);
5465 static int mem_cgroup_oom_register_event(struct cgroup_subsys_state *css,
5466 struct cftype *cft, struct eventfd_ctx *eventfd, const char *args)
5468 struct mem_cgroup *memcg = mem_cgroup_from_css(css);
5469 struct mem_cgroup_eventfd_list *event;
5470 enum res_type type = MEMFILE_TYPE(cft->private);
5472 BUG_ON(type != _OOM_TYPE);
5473 event = kmalloc(sizeof(*event), GFP_KERNEL);
5477 spin_lock(&memcg_oom_lock);
5479 event->eventfd = eventfd;
5480 list_add(&event->list, &memcg->oom_notify);
5482 /* already in OOM ? */
5483 if (atomic_read(&memcg->under_oom))
5484 eventfd_signal(eventfd, 1);
5485 spin_unlock(&memcg_oom_lock);
5490 static void mem_cgroup_oom_unregister_event(struct cgroup_subsys_state *css,
5491 struct cftype *cft, struct eventfd_ctx *eventfd)
5493 struct mem_cgroup *memcg = mem_cgroup_from_css(css);
5494 struct mem_cgroup_eventfd_list *ev, *tmp;
5495 enum res_type type = MEMFILE_TYPE(cft->private);
5497 BUG_ON(type != _OOM_TYPE);
5499 spin_lock(&memcg_oom_lock);
5501 list_for_each_entry_safe(ev, tmp, &memcg->oom_notify, list) {
5502 if (ev->eventfd == eventfd) {
5503 list_del(&ev->list);
5508 spin_unlock(&memcg_oom_lock);
5511 static int mem_cgroup_oom_control_read(struct cgroup_subsys_state *css,
5512 struct cftype *cft, struct cgroup_map_cb *cb)
5514 struct mem_cgroup *memcg = mem_cgroup_from_css(css);
5516 cb->fill(cb, "oom_kill_disable", memcg->oom_kill_disable);
5518 if (atomic_read(&memcg->under_oom))
5519 cb->fill(cb, "under_oom", 1);
5521 cb->fill(cb, "under_oom", 0);
5525 static int mem_cgroup_oom_control_write(struct cgroup_subsys_state *css,
5526 struct cftype *cft, u64 val)
5528 struct mem_cgroup *memcg = mem_cgroup_from_css(css);
5529 struct mem_cgroup *parent = mem_cgroup_from_css(css_parent(&memcg->css));
5531 /* cannot set to root cgroup and only 0 and 1 are allowed */
5532 if (!parent || !((val == 0) || (val == 1)))
5535 mutex_lock(&memcg_create_mutex);
5536 /* oom-kill-disable is a flag for subhierarchy. */
5537 if ((parent->use_hierarchy) || memcg_has_children(memcg)) {
5538 mutex_unlock(&memcg_create_mutex);
5541 memcg->oom_kill_disable = val;
5543 memcg_oom_recover(memcg);
5544 mutex_unlock(&memcg_create_mutex);
5548 #ifdef CONFIG_MEMCG_KMEM
5549 static int memcg_init_kmem(struct mem_cgroup *memcg, struct cgroup_subsys *ss)
5553 memcg->kmemcg_id = -1;
5554 ret = memcg_propagate_kmem(memcg);
5558 return mem_cgroup_sockets_init(memcg, ss);
5561 static void memcg_destroy_kmem(struct mem_cgroup *memcg)
5563 mem_cgroup_sockets_destroy(memcg);
5566 static void kmem_cgroup_css_offline(struct mem_cgroup *memcg)
5568 if (!memcg_kmem_is_active(memcg))
5572 * kmem charges can outlive the cgroup. In the case of slab
5573 * pages, for instance, a page contain objects from various
5574 * processes. As we prevent from taking a reference for every
5575 * such allocation we have to be careful when doing uncharge
5576 * (see memcg_uncharge_kmem) and here during offlining.
5578 * The idea is that that only the _last_ uncharge which sees
5579 * the dead memcg will drop the last reference. An additional
5580 * reference is taken here before the group is marked dead
5581 * which is then paired with css_put during uncharge resp. here.
5583 * Although this might sound strange as this path is called from
5584 * css_offline() when the referencemight have dropped down to 0
5585 * and shouldn't be incremented anymore (css_tryget would fail)
5586 * we do not have other options because of the kmem allocations
5589 css_get(&memcg->css);
5591 memcg_kmem_mark_dead(memcg);
5593 if (res_counter_read_u64(&memcg->kmem, RES_USAGE) != 0)
5596 if (memcg_kmem_test_and_clear_dead(memcg))
5597 css_put(&memcg->css);
5600 static int memcg_init_kmem(struct mem_cgroup *memcg, struct cgroup_subsys *ss)
5605 static void memcg_destroy_kmem(struct mem_cgroup *memcg)
5609 static void kmem_cgroup_css_offline(struct mem_cgroup *memcg)
5614 static struct cftype mem_cgroup_files[] = {
5616 .name = "usage_in_bytes",
5617 .private = MEMFILE_PRIVATE(_MEM, RES_USAGE),
5618 .read = mem_cgroup_read,
5619 .register_event = mem_cgroup_usage_register_event,
5620 .unregister_event = mem_cgroup_usage_unregister_event,
5623 .name = "max_usage_in_bytes",
5624 .private = MEMFILE_PRIVATE(_MEM, RES_MAX_USAGE),
5625 .trigger = mem_cgroup_reset,
5626 .read = mem_cgroup_read,
5629 .name = "limit_in_bytes",
5630 .private = MEMFILE_PRIVATE(_MEM, RES_LIMIT),
5631 .write_string = mem_cgroup_write,
5632 .read = mem_cgroup_read,
5635 .name = "soft_limit_in_bytes",
5636 .private = MEMFILE_PRIVATE(_MEM, RES_SOFT_LIMIT),
5637 .write_string = mem_cgroup_write,
5638 .read = mem_cgroup_read,
5642 .private = MEMFILE_PRIVATE(_MEM, RES_FAILCNT),
5643 .trigger = mem_cgroup_reset,
5644 .read = mem_cgroup_read,
5648 .read_seq_string = memcg_stat_show,
5651 .name = "force_empty",
5652 .trigger = mem_cgroup_force_empty_write,
5655 .name = "use_hierarchy",
5656 .flags = CFTYPE_INSANE,
5657 .write_u64 = mem_cgroup_hierarchy_write,
5658 .read_u64 = mem_cgroup_hierarchy_read,
5661 .name = "swappiness",
5662 .read_u64 = mem_cgroup_swappiness_read,
5663 .write_u64 = mem_cgroup_swappiness_write,
5666 .name = "move_charge_at_immigrate",
5667 .read_u64 = mem_cgroup_move_charge_read,
5668 .write_u64 = mem_cgroup_move_charge_write,
5671 .name = "oom_control",
5672 .read_map = mem_cgroup_oom_control_read,
5673 .write_u64 = mem_cgroup_oom_control_write,
5674 .register_event = mem_cgroup_oom_register_event,
5675 .unregister_event = mem_cgroup_oom_unregister_event,
5676 .private = MEMFILE_PRIVATE(_OOM_TYPE, OOM_CONTROL),
5679 .name = "pressure_level",
5680 .register_event = vmpressure_register_event,
5681 .unregister_event = vmpressure_unregister_event,
5685 .name = "numa_stat",
5686 .read_seq_string = memcg_numa_stat_show,
5689 #ifdef CONFIG_MEMCG_KMEM
5691 .name = "kmem.limit_in_bytes",
5692 .private = MEMFILE_PRIVATE(_KMEM, RES_LIMIT),
5693 .write_string = mem_cgroup_write,
5694 .read = mem_cgroup_read,
5697 .name = "kmem.usage_in_bytes",
5698 .private = MEMFILE_PRIVATE(_KMEM, RES_USAGE),
5699 .read = mem_cgroup_read,
5702 .name = "kmem.failcnt",
5703 .private = MEMFILE_PRIVATE(_KMEM, RES_FAILCNT),
5704 .trigger = mem_cgroup_reset,
5705 .read = mem_cgroup_read,
5708 .name = "kmem.max_usage_in_bytes",
5709 .private = MEMFILE_PRIVATE(_KMEM, RES_MAX_USAGE),
5710 .trigger = mem_cgroup_reset,
5711 .read = mem_cgroup_read,
5713 #ifdef CONFIG_SLABINFO
5715 .name = "kmem.slabinfo",
5716 .read_seq_string = mem_cgroup_slabinfo_read,
5720 { }, /* terminate */
5723 #ifdef CONFIG_MEMCG_SWAP
5724 static struct cftype memsw_cgroup_files[] = {
5726 .name = "memsw.usage_in_bytes",
5727 .private = MEMFILE_PRIVATE(_MEMSWAP, RES_USAGE),
5728 .read = mem_cgroup_read,
5729 .register_event = mem_cgroup_usage_register_event,
5730 .unregister_event = mem_cgroup_usage_unregister_event,
5733 .name = "memsw.max_usage_in_bytes",
5734 .private = MEMFILE_PRIVATE(_MEMSWAP, RES_MAX_USAGE),
5735 .trigger = mem_cgroup_reset,
5736 .read = mem_cgroup_read,
5739 .name = "memsw.limit_in_bytes",
5740 .private = MEMFILE_PRIVATE(_MEMSWAP, RES_LIMIT),
5741 .write_string = mem_cgroup_write,
5742 .read = mem_cgroup_read,
5745 .name = "memsw.failcnt",
5746 .private = MEMFILE_PRIVATE(_MEMSWAP, RES_FAILCNT),
5747 .trigger = mem_cgroup_reset,
5748 .read = mem_cgroup_read,
5750 { }, /* terminate */
5753 static int alloc_mem_cgroup_per_zone_info(struct mem_cgroup *memcg, int node)
5755 struct mem_cgroup_per_node *pn;
5756 struct mem_cgroup_per_zone *mz;
5757 int zone, tmp = node;
5759 * This routine is called against possible nodes.
5760 * But it's BUG to call kmalloc() against offline node.
5762 * TODO: this routine can waste much memory for nodes which will
5763 * never be onlined. It's better to use memory hotplug callback
5766 if (!node_state(node, N_NORMAL_MEMORY))
5768 pn = kzalloc_node(sizeof(*pn), GFP_KERNEL, tmp);
5772 for (zone = 0; zone < MAX_NR_ZONES; zone++) {
5773 mz = &pn->zoneinfo[zone];
5774 lruvec_init(&mz->lruvec);
5777 memcg->nodeinfo[node] = pn;
5781 static void free_mem_cgroup_per_zone_info(struct mem_cgroup *memcg, int node)
5783 kfree(memcg->nodeinfo[node]);
5786 static struct mem_cgroup *mem_cgroup_alloc(void)
5788 struct mem_cgroup *memcg;
5789 size_t size = memcg_size();
5791 /* Can be very big if nr_node_ids is very big */
5792 if (size < PAGE_SIZE)
5793 memcg = kzalloc(size, GFP_KERNEL);
5795 memcg = vzalloc(size);
5800 memcg->stat = alloc_percpu(struct mem_cgroup_stat_cpu);
5803 spin_lock_init(&memcg->pcp_counter_lock);
5807 if (size < PAGE_SIZE)
5815 * At destroying mem_cgroup, references from swap_cgroup can remain.
5816 * (scanning all at force_empty is too costly...)
5818 * Instead of clearing all references at force_empty, we remember
5819 * the number of reference from swap_cgroup and free mem_cgroup when
5820 * it goes down to 0.
5822 * Removal of cgroup itself succeeds regardless of refs from swap.
5825 static void __mem_cgroup_free(struct mem_cgroup *memcg)
5828 size_t size = memcg_size();
5830 free_css_id(&mem_cgroup_subsys, &memcg->css);
5833 free_mem_cgroup_per_zone_info(memcg, node);
5835 free_percpu(memcg->stat);
5838 * We need to make sure that (at least for now), the jump label
5839 * destruction code runs outside of the cgroup lock. This is because
5840 * get_online_cpus(), which is called from the static_branch update,
5841 * can't be called inside the cgroup_lock. cpusets are the ones
5842 * enforcing this dependency, so if they ever change, we might as well.
5844 * schedule_work() will guarantee this happens. Be careful if you need
5845 * to move this code around, and make sure it is outside
5848 disarm_static_keys(memcg);
5849 if (size < PAGE_SIZE)
5856 * Returns the parent mem_cgroup in memcgroup hierarchy with hierarchy enabled.
5858 struct mem_cgroup *parent_mem_cgroup(struct mem_cgroup *memcg)
5860 if (!memcg->res.parent)
5862 return mem_cgroup_from_res_counter(memcg->res.parent, res);
5864 EXPORT_SYMBOL(parent_mem_cgroup);
5866 static struct cgroup_subsys_state * __ref
5867 mem_cgroup_css_alloc(struct cgroup_subsys_state *parent_css)
5869 struct mem_cgroup *memcg;
5870 long error = -ENOMEM;
5873 memcg = mem_cgroup_alloc();
5875 return ERR_PTR(error);
5878 if (alloc_mem_cgroup_per_zone_info(memcg, node))
5882 if (parent_css == NULL) {
5883 root_mem_cgroup = memcg;
5884 res_counter_init(&memcg->res, NULL);
5885 res_counter_init(&memcg->memsw, NULL);
5886 res_counter_init(&memcg->kmem, NULL);
5889 memcg->last_scanned_node = MAX_NUMNODES;
5890 INIT_LIST_HEAD(&memcg->oom_notify);
5891 memcg->move_charge_at_immigrate = 0;
5892 mutex_init(&memcg->thresholds_lock);
5893 spin_lock_init(&memcg->move_lock);
5894 vmpressure_init(&memcg->vmpressure);
5899 __mem_cgroup_free(memcg);
5900 return ERR_PTR(error);
5904 mem_cgroup_css_online(struct cgroup_subsys_state *css)
5906 struct mem_cgroup *memcg = mem_cgroup_from_css(css);
5907 struct mem_cgroup *parent = mem_cgroup_from_css(css_parent(css));
5913 mutex_lock(&memcg_create_mutex);
5915 memcg->use_hierarchy = parent->use_hierarchy;
5916 memcg->oom_kill_disable = parent->oom_kill_disable;
5917 memcg->swappiness = mem_cgroup_swappiness(parent);
5919 if (parent->use_hierarchy) {
5920 res_counter_init(&memcg->res, &parent->res);
5921 res_counter_init(&memcg->memsw, &parent->memsw);
5922 res_counter_init(&memcg->kmem, &parent->kmem);
5925 * No need to take a reference to the parent because cgroup
5926 * core guarantees its existence.
5929 res_counter_init(&memcg->res, NULL);
5930 res_counter_init(&memcg->memsw, NULL);
5931 res_counter_init(&memcg->kmem, NULL);
5933 * Deeper hierachy with use_hierarchy == false doesn't make
5934 * much sense so let cgroup subsystem know about this
5935 * unfortunate state in our controller.
5937 if (parent != root_mem_cgroup)
5938 mem_cgroup_subsys.broken_hierarchy = true;
5941 error = memcg_init_kmem(memcg, &mem_cgroup_subsys);
5942 mutex_unlock(&memcg_create_mutex);
5947 * Announce all parents that a group from their hierarchy is gone.
5949 static void mem_cgroup_invalidate_reclaim_iterators(struct mem_cgroup *memcg)
5951 struct mem_cgroup *parent = memcg;
5953 while ((parent = parent_mem_cgroup(parent)))
5954 mem_cgroup_iter_invalidate(parent);
5957 * if the root memcg is not hierarchical we have to check it
5960 if (!root_mem_cgroup->use_hierarchy)
5961 mem_cgroup_iter_invalidate(root_mem_cgroup);
5964 static void mem_cgroup_css_offline(struct cgroup_subsys_state *css)
5966 struct mem_cgroup *memcg = mem_cgroup_from_css(css);
5968 kmem_cgroup_css_offline(memcg);
5970 mem_cgroup_invalidate_reclaim_iterators(memcg);
5971 mem_cgroup_reparent_charges(memcg);
5972 mem_cgroup_destroy_all_caches(memcg);
5973 vmpressure_cleanup(&memcg->vmpressure);
5976 static void mem_cgroup_css_free(struct cgroup_subsys_state *css)
5978 struct mem_cgroup *memcg = mem_cgroup_from_css(css);
5980 memcg_destroy_kmem(memcg);
5981 __mem_cgroup_free(memcg);
5985 /* Handlers for move charge at task migration. */
5986 #define PRECHARGE_COUNT_AT_ONCE 256
5987 static int mem_cgroup_do_precharge(unsigned long count)
5990 int batch_count = PRECHARGE_COUNT_AT_ONCE;
5991 struct mem_cgroup *memcg = mc.to;
5993 if (mem_cgroup_is_root(memcg)) {
5994 mc.precharge += count;
5995 /* we don't need css_get for root */
5998 /* try to charge at once */
6000 struct res_counter *dummy;
6002 * "memcg" cannot be under rmdir() because we've already checked
6003 * by cgroup_lock_live_cgroup() that it is not removed and we
6004 * are still under the same cgroup_mutex. So we can postpone
6007 if (res_counter_charge(&memcg->res, PAGE_SIZE * count, &dummy))
6009 if (do_swap_account && res_counter_charge(&memcg->memsw,
6010 PAGE_SIZE * count, &dummy)) {
6011 res_counter_uncharge(&memcg->res, PAGE_SIZE * count);
6014 mc.precharge += count;
6018 /* fall back to one by one charge */
6020 if (signal_pending(current)) {
6024 if (!batch_count--) {
6025 batch_count = PRECHARGE_COUNT_AT_ONCE;
6028 ret = __mem_cgroup_try_charge(NULL,
6029 GFP_KERNEL, 1, &memcg, false);
6031 /* mem_cgroup_clear_mc() will do uncharge later */
6039 * get_mctgt_type - get target type of moving charge
6040 * @vma: the vma the pte to be checked belongs
6041 * @addr: the address corresponding to the pte to be checked
6042 * @ptent: the pte to be checked
6043 * @target: the pointer the target page or swap ent will be stored(can be NULL)
6046 * 0(MC_TARGET_NONE): if the pte is not a target for move charge.
6047 * 1(MC_TARGET_PAGE): if the page corresponding to this pte is a target for
6048 * move charge. if @target is not NULL, the page is stored in target->page
6049 * with extra refcnt got(Callers should handle it).
6050 * 2(MC_TARGET_SWAP): if the swap entry corresponding to this pte is a
6051 * target for charge migration. if @target is not NULL, the entry is stored
6054 * Called with pte lock held.
6061 enum mc_target_type {
6067 static struct page *mc_handle_present_pte(struct vm_area_struct *vma,
6068 unsigned long addr, pte_t ptent)
6070 struct page *page = vm_normal_page(vma, addr, ptent);
6072 if (!page || !page_mapped(page))
6074 if (PageAnon(page)) {
6075 /* we don't move shared anon */
6078 } else if (!move_file())
6079 /* we ignore mapcount for file pages */
6081 if (!get_page_unless_zero(page))
6088 static struct page *mc_handle_swap_pte(struct vm_area_struct *vma,
6089 unsigned long addr, pte_t ptent, swp_entry_t *entry)
6091 struct page *page = NULL;
6092 swp_entry_t ent = pte_to_swp_entry(ptent);
6094 if (!move_anon() || non_swap_entry(ent))
6097 * Because lookup_swap_cache() updates some statistics counter,
6098 * we call find_get_page() with swapper_space directly.
6100 page = find_get_page(swap_address_space(ent), ent.val);
6101 if (do_swap_account)
6102 entry->val = ent.val;
6107 static struct page *mc_handle_swap_pte(struct vm_area_struct *vma,
6108 unsigned long addr, pte_t ptent, swp_entry_t *entry)
6114 static struct page *mc_handle_file_pte(struct vm_area_struct *vma,
6115 unsigned long addr, pte_t ptent, swp_entry_t *entry)
6117 struct page *page = NULL;
6118 struct address_space *mapping;
6121 if (!vma->vm_file) /* anonymous vma */
6126 mapping = vma->vm_file->f_mapping;
6127 if (pte_none(ptent))
6128 pgoff = linear_page_index(vma, addr);
6129 else /* pte_file(ptent) is true */
6130 pgoff = pte_to_pgoff(ptent);
6132 /* page is moved even if it's not RSS of this task(page-faulted). */
6133 page = find_get_page(mapping, pgoff);
6136 /* shmem/tmpfs may report page out on swap: account for that too. */
6137 if (radix_tree_exceptional_entry(page)) {
6138 swp_entry_t swap = radix_to_swp_entry(page);
6139 if (do_swap_account)
6141 page = find_get_page(swap_address_space(swap), swap.val);
6147 static enum mc_target_type get_mctgt_type(struct vm_area_struct *vma,
6148 unsigned long addr, pte_t ptent, union mc_target *target)
6150 struct page *page = NULL;
6151 struct page_cgroup *pc;
6152 enum mc_target_type ret = MC_TARGET_NONE;
6153 swp_entry_t ent = { .val = 0 };
6155 if (pte_present(ptent))
6156 page = mc_handle_present_pte(vma, addr, ptent);
6157 else if (is_swap_pte(ptent))
6158 page = mc_handle_swap_pte(vma, addr, ptent, &ent);
6159 else if (pte_none(ptent) || pte_file(ptent))
6160 page = mc_handle_file_pte(vma, addr, ptent, &ent);
6162 if (!page && !ent.val)
6165 pc = lookup_page_cgroup(page);
6167 * Do only loose check w/o page_cgroup lock.
6168 * mem_cgroup_move_account() checks the pc is valid or not under
6171 if (PageCgroupUsed(pc) && pc->mem_cgroup == mc.from) {
6172 ret = MC_TARGET_PAGE;
6174 target->page = page;
6176 if (!ret || !target)
6179 /* There is a swap entry and a page doesn't exist or isn't charged */
6180 if (ent.val && !ret &&
6181 css_id(&mc.from->css) == lookup_swap_cgroup_id(ent)) {
6182 ret = MC_TARGET_SWAP;
6189 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
6191 * We don't consider swapping or file mapped pages because THP does not
6192 * support them for now.
6193 * Caller should make sure that pmd_trans_huge(pmd) is true.
6195 static enum mc_target_type get_mctgt_type_thp(struct vm_area_struct *vma,
6196 unsigned long addr, pmd_t pmd, union mc_target *target)
6198 struct page *page = NULL;
6199 struct page_cgroup *pc;
6200 enum mc_target_type ret = MC_TARGET_NONE;
6202 page = pmd_page(pmd);
6203 VM_BUG_ON(!page || !PageHead(page));
6206 pc = lookup_page_cgroup(page);
6207 if (PageCgroupUsed(pc) && pc->mem_cgroup == mc.from) {
6208 ret = MC_TARGET_PAGE;
6211 target->page = page;
6217 static inline enum mc_target_type get_mctgt_type_thp(struct vm_area_struct *vma,
6218 unsigned long addr, pmd_t pmd, union mc_target *target)
6220 return MC_TARGET_NONE;
6224 static int mem_cgroup_count_precharge_pte_range(pmd_t *pmd,
6225 unsigned long addr, unsigned long end,
6226 struct mm_walk *walk)
6228 struct vm_area_struct *vma = walk->private;
6232 if (pmd_trans_huge_lock(pmd, vma) == 1) {
6233 if (get_mctgt_type_thp(vma, addr, *pmd, NULL) == MC_TARGET_PAGE)
6234 mc.precharge += HPAGE_PMD_NR;
6235 spin_unlock(&vma->vm_mm->page_table_lock);
6239 if (pmd_trans_unstable(pmd))
6241 pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl);
6242 for (; addr != end; pte++, addr += PAGE_SIZE)
6243 if (get_mctgt_type(vma, addr, *pte, NULL))
6244 mc.precharge++; /* increment precharge temporarily */
6245 pte_unmap_unlock(pte - 1, ptl);
6251 static unsigned long mem_cgroup_count_precharge(struct mm_struct *mm)
6253 unsigned long precharge;
6254 struct vm_area_struct *vma;
6256 down_read(&mm->mmap_sem);
6257 for (vma = mm->mmap; vma; vma = vma->vm_next) {
6258 struct mm_walk mem_cgroup_count_precharge_walk = {
6259 .pmd_entry = mem_cgroup_count_precharge_pte_range,
6263 if (is_vm_hugetlb_page(vma))
6265 walk_page_range(vma->vm_start, vma->vm_end,
6266 &mem_cgroup_count_precharge_walk);
6268 up_read(&mm->mmap_sem);
6270 precharge = mc.precharge;
6276 static int mem_cgroup_precharge_mc(struct mm_struct *mm)
6278 unsigned long precharge = mem_cgroup_count_precharge(mm);
6280 VM_BUG_ON(mc.moving_task);
6281 mc.moving_task = current;
6282 return mem_cgroup_do_precharge(precharge);
6285 /* cancels all extra charges on mc.from and mc.to, and wakes up all waiters. */
6286 static void __mem_cgroup_clear_mc(void)
6288 struct mem_cgroup *from = mc.from;
6289 struct mem_cgroup *to = mc.to;
6292 /* we must uncharge all the leftover precharges from mc.to */
6294 __mem_cgroup_cancel_charge(mc.to, mc.precharge);
6298 * we didn't uncharge from mc.from at mem_cgroup_move_account(), so
6299 * we must uncharge here.
6301 if (mc.moved_charge) {
6302 __mem_cgroup_cancel_charge(mc.from, mc.moved_charge);
6303 mc.moved_charge = 0;
6305 /* we must fixup refcnts and charges */
6306 if (mc.moved_swap) {
6307 /* uncharge swap account from the old cgroup */
6308 if (!mem_cgroup_is_root(mc.from))
6309 res_counter_uncharge(&mc.from->memsw,
6310 PAGE_SIZE * mc.moved_swap);
6312 for (i = 0; i < mc.moved_swap; i++)
6313 css_put(&mc.from->css);
6315 if (!mem_cgroup_is_root(mc.to)) {
6317 * we charged both to->res and to->memsw, so we should
6320 res_counter_uncharge(&mc.to->res,
6321 PAGE_SIZE * mc.moved_swap);
6323 /* we've already done css_get(mc.to) */
6326 memcg_oom_recover(from);
6327 memcg_oom_recover(to);
6328 wake_up_all(&mc.waitq);
6331 static void mem_cgroup_clear_mc(void)
6333 struct mem_cgroup *from = mc.from;
6336 * we must clear moving_task before waking up waiters at the end of
6339 mc.moving_task = NULL;
6340 __mem_cgroup_clear_mc();
6341 spin_lock(&mc.lock);
6344 spin_unlock(&mc.lock);
6345 mem_cgroup_end_move(from);
6348 static int mem_cgroup_can_attach(struct cgroup_subsys_state *css,
6349 struct cgroup_taskset *tset)
6351 struct task_struct *p = cgroup_taskset_first(tset);
6353 struct mem_cgroup *memcg = mem_cgroup_from_css(css);
6354 unsigned long move_charge_at_immigrate;
6357 * We are now commited to this value whatever it is. Changes in this
6358 * tunable will only affect upcoming migrations, not the current one.
6359 * So we need to save it, and keep it going.
6361 move_charge_at_immigrate = memcg->move_charge_at_immigrate;
6362 if (move_charge_at_immigrate) {
6363 struct mm_struct *mm;
6364 struct mem_cgroup *from = mem_cgroup_from_task(p);
6366 VM_BUG_ON(from == memcg);
6368 mm = get_task_mm(p);
6371 /* We move charges only when we move a owner of the mm */
6372 if (mm->owner == p) {
6375 VM_BUG_ON(mc.precharge);
6376 VM_BUG_ON(mc.moved_charge);
6377 VM_BUG_ON(mc.moved_swap);
6378 mem_cgroup_start_move(from);
6379 spin_lock(&mc.lock);
6382 mc.immigrate_flags = move_charge_at_immigrate;
6383 spin_unlock(&mc.lock);
6384 /* We set mc.moving_task later */
6386 ret = mem_cgroup_precharge_mc(mm);
6388 mem_cgroup_clear_mc();
6395 static void mem_cgroup_cancel_attach(struct cgroup_subsys_state *css,
6396 struct cgroup_taskset *tset)
6398 mem_cgroup_clear_mc();
6401 static int mem_cgroup_move_charge_pte_range(pmd_t *pmd,
6402 unsigned long addr, unsigned long end,
6403 struct mm_walk *walk)
6406 struct vm_area_struct *vma = walk->private;
6409 enum mc_target_type target_type;
6410 union mc_target target;
6412 struct page_cgroup *pc;
6415 * We don't take compound_lock() here but no race with splitting thp
6417 * - if pmd_trans_huge_lock() returns 1, the relevant thp is not
6418 * under splitting, which means there's no concurrent thp split,
6419 * - if another thread runs into split_huge_page() just after we
6420 * entered this if-block, the thread must wait for page table lock
6421 * to be unlocked in __split_huge_page_splitting(), where the main
6422 * part of thp split is not executed yet.
6424 if (pmd_trans_huge_lock(pmd, vma) == 1) {
6425 if (mc.precharge < HPAGE_PMD_NR) {
6426 spin_unlock(&vma->vm_mm->page_table_lock);
6429 target_type = get_mctgt_type_thp(vma, addr, *pmd, &target);
6430 if (target_type == MC_TARGET_PAGE) {
6432 if (!isolate_lru_page(page)) {
6433 pc = lookup_page_cgroup(page);
6434 if (!mem_cgroup_move_account(page, HPAGE_PMD_NR,
6435 pc, mc.from, mc.to)) {
6436 mc.precharge -= HPAGE_PMD_NR;
6437 mc.moved_charge += HPAGE_PMD_NR;
6439 putback_lru_page(page);
6443 spin_unlock(&vma->vm_mm->page_table_lock);
6447 if (pmd_trans_unstable(pmd))
6450 pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl);
6451 for (; addr != end; addr += PAGE_SIZE) {
6452 pte_t ptent = *(pte++);
6458 switch (get_mctgt_type(vma, addr, ptent, &target)) {
6459 case MC_TARGET_PAGE:
6461 if (isolate_lru_page(page))
6463 pc = lookup_page_cgroup(page);
6464 if (!mem_cgroup_move_account(page, 1, pc,
6467 /* we uncharge from mc.from later. */
6470 putback_lru_page(page);
6471 put: /* get_mctgt_type() gets the page */
6474 case MC_TARGET_SWAP:
6476 if (!mem_cgroup_move_swap_account(ent, mc.from, mc.to)) {
6478 /* we fixup refcnts and charges later. */
6486 pte_unmap_unlock(pte - 1, ptl);
6491 * We have consumed all precharges we got in can_attach().
6492 * We try charge one by one, but don't do any additional
6493 * charges to mc.to if we have failed in charge once in attach()
6496 ret = mem_cgroup_do_precharge(1);
6504 static void mem_cgroup_move_charge(struct mm_struct *mm)
6506 struct vm_area_struct *vma;
6508 lru_add_drain_all();
6510 if (unlikely(!down_read_trylock(&mm->mmap_sem))) {
6512 * Someone who are holding the mmap_sem might be waiting in
6513 * waitq. So we cancel all extra charges, wake up all waiters,
6514 * and retry. Because we cancel precharges, we might not be able
6515 * to move enough charges, but moving charge is a best-effort
6516 * feature anyway, so it wouldn't be a big problem.
6518 __mem_cgroup_clear_mc();
6522 for (vma = mm->mmap; vma; vma = vma->vm_next) {
6524 struct mm_walk mem_cgroup_move_charge_walk = {
6525 .pmd_entry = mem_cgroup_move_charge_pte_range,
6529 if (is_vm_hugetlb_page(vma))
6531 ret = walk_page_range(vma->vm_start, vma->vm_end,
6532 &mem_cgroup_move_charge_walk);
6535 * means we have consumed all precharges and failed in
6536 * doing additional charge. Just abandon here.
6540 up_read(&mm->mmap_sem);
6543 static void mem_cgroup_move_task(struct cgroup_subsys_state *css,
6544 struct cgroup_taskset *tset)
6546 struct task_struct *p = cgroup_taskset_first(tset);
6547 struct mm_struct *mm = get_task_mm(p);
6551 mem_cgroup_move_charge(mm);
6555 mem_cgroup_clear_mc();
6557 #else /* !CONFIG_MMU */
6558 static int mem_cgroup_can_attach(struct cgroup_subsys_state *css,
6559 struct cgroup_taskset *tset)
6563 static void mem_cgroup_cancel_attach(struct cgroup_subsys_state *css,
6564 struct cgroup_taskset *tset)
6567 static void mem_cgroup_move_task(struct cgroup_subsys_state *css,
6568 struct cgroup_taskset *tset)
6574 * Cgroup retains root cgroups across [un]mount cycles making it necessary
6575 * to verify sane_behavior flag on each mount attempt.
6577 static void mem_cgroup_bind(struct cgroup_subsys_state *root_css)
6580 * use_hierarchy is forced with sane_behavior. cgroup core
6581 * guarantees that @root doesn't have any children, so turning it
6582 * on for the root memcg is enough.
6584 if (cgroup_sane_behavior(root_css->cgroup))
6585 mem_cgroup_from_css(root_css)->use_hierarchy = true;
6588 struct cgroup_subsys mem_cgroup_subsys = {
6590 .subsys_id = mem_cgroup_subsys_id,
6591 .css_alloc = mem_cgroup_css_alloc,
6592 .css_online = mem_cgroup_css_online,
6593 .css_offline = mem_cgroup_css_offline,
6594 .css_free = mem_cgroup_css_free,
6595 .can_attach = mem_cgroup_can_attach,
6596 .cancel_attach = mem_cgroup_cancel_attach,
6597 .attach = mem_cgroup_move_task,
6598 .bind = mem_cgroup_bind,
6599 .base_cftypes = mem_cgroup_files,
6604 #ifdef CONFIG_MEMCG_SWAP
6605 static int __init enable_swap_account(char *s)
6607 if (!strcmp(s, "1"))
6608 really_do_swap_account = 1;
6609 else if (!strcmp(s, "0"))
6610 really_do_swap_account = 0;
6613 __setup("swapaccount=", enable_swap_account);
6615 static void __init memsw_file_init(void)
6617 WARN_ON(cgroup_add_cftypes(&mem_cgroup_subsys, memsw_cgroup_files));
6620 static void __init enable_swap_cgroup(void)
6622 if (!mem_cgroup_disabled() && really_do_swap_account) {
6623 do_swap_account = 1;
6629 static void __init enable_swap_cgroup(void)
6635 * subsys_initcall() for memory controller.
6637 * Some parts like hotcpu_notifier() have to be initialized from this context
6638 * because of lock dependencies (cgroup_lock -> cpu hotplug) but basically
6639 * everything that doesn't depend on a specific mem_cgroup structure should
6640 * be initialized from here.
6642 static int __init mem_cgroup_init(void)
6644 hotcpu_notifier(memcg_cpu_hotplug_callback, 0);
6645 enable_swap_cgroup();
6649 subsys_initcall(mem_cgroup_init);