1 /* memcontrol.c - Memory Controller
3 * Copyright IBM Corporation, 2007
4 * Author Balbir Singh <balbir@linux.vnet.ibm.com>
6 * Copyright 2007 OpenVZ SWsoft Inc
7 * Author: Pavel Emelianov <xemul@openvz.org>
10 * Copyright (C) 2009 Nokia Corporation
11 * Author: Kirill A. Shutemov
13 * Kernel Memory Controller
14 * Copyright (C) 2012 Parallels Inc. and Google Inc.
15 * Authors: Glauber Costa and Suleiman Souhlal
18 * Charge lifetime sanitation
19 * Lockless page tracking & accounting
20 * Unified hierarchy configuration model
21 * Copyright (C) 2015 Red Hat, Inc., Johannes Weiner
23 * This program is free software; you can redistribute it and/or modify
24 * it under the terms of the GNU General Public License as published by
25 * the Free Software Foundation; either version 2 of the License, or
26 * (at your option) any later version.
28 * This program is distributed in the hope that it will be useful,
29 * but WITHOUT ANY WARRANTY; without even the implied warranty of
30 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
31 * GNU General Public License for more details.
34 #include <linux/page_counter.h>
35 #include <linux/memcontrol.h>
36 #include <linux/cgroup.h>
38 #include <linux/hugetlb.h>
39 #include <linux/pagemap.h>
40 #include <linux/smp.h>
41 #include <linux/page-flags.h>
42 #include <linux/backing-dev.h>
43 #include <linux/bit_spinlock.h>
44 #include <linux/rcupdate.h>
45 #include <linux/limits.h>
46 #include <linux/export.h>
47 #include <linux/mutex.h>
48 #include <linux/rbtree.h>
49 #include <linux/slab.h>
50 #include <linux/swap.h>
51 #include <linux/swapops.h>
52 #include <linux/spinlock.h>
53 #include <linux/eventfd.h>
54 #include <linux/poll.h>
55 #include <linux/sort.h>
57 #include <linux/seq_file.h>
58 #include <linux/vmpressure.h>
59 #include <linux/mm_inline.h>
60 #include <linux/swap_cgroup.h>
61 #include <linux/cpu.h>
62 #include <linux/oom.h>
63 #include <linux/lockdep.h>
64 #include <linux/file.h>
68 #include <net/tcp_memcontrol.h>
71 #include <asm/uaccess.h>
73 #include <trace/events/vmscan.h>
75 struct cgroup_subsys memory_cgrp_subsys __read_mostly
;
76 EXPORT_SYMBOL(memory_cgrp_subsys
);
78 #define MEM_CGROUP_RECLAIM_RETRIES 5
79 static struct mem_cgroup
*root_mem_cgroup __read_mostly
;
80 struct cgroup_subsys_state
*mem_cgroup_root_css __read_mostly
;
82 /* Whether the swap controller is active */
83 #ifdef CONFIG_MEMCG_SWAP
84 int do_swap_account __read_mostly
;
86 #define do_swap_account 0
89 static const char * const mem_cgroup_stat_names
[] = {
99 static const char * const mem_cgroup_events_names
[] = {
106 static const char * const mem_cgroup_lru_names
[] = {
114 #define THRESHOLDS_EVENTS_TARGET 128
115 #define SOFTLIMIT_EVENTS_TARGET 1024
116 #define NUMAINFO_EVENTS_TARGET 1024
119 * Cgroups above their limits are maintained in a RB-Tree, independent of
120 * their hierarchy representation
123 struct mem_cgroup_tree_per_zone
{
124 struct rb_root rb_root
;
128 struct mem_cgroup_tree_per_node
{
129 struct mem_cgroup_tree_per_zone rb_tree_per_zone
[MAX_NR_ZONES
];
132 struct mem_cgroup_tree
{
133 struct mem_cgroup_tree_per_node
*rb_tree_per_node
[MAX_NUMNODES
];
136 static struct mem_cgroup_tree soft_limit_tree __read_mostly
;
139 struct mem_cgroup_eventfd_list
{
140 struct list_head list
;
141 struct eventfd_ctx
*eventfd
;
145 * cgroup_event represents events which userspace want to receive.
147 struct mem_cgroup_event
{
149 * memcg which the event belongs to.
151 struct mem_cgroup
*memcg
;
153 * eventfd to signal userspace about the event.
155 struct eventfd_ctx
*eventfd
;
157 * Each of these stored in a list by the cgroup.
159 struct list_head list
;
161 * register_event() callback will be used to add new userspace
162 * waiter for changes related to this event. Use eventfd_signal()
163 * on eventfd to send notification to userspace.
165 int (*register_event
)(struct mem_cgroup
*memcg
,
166 struct eventfd_ctx
*eventfd
, const char *args
);
168 * unregister_event() callback will be called when userspace closes
169 * the eventfd or on cgroup removing. This callback must be set,
170 * if you want provide notification functionality.
172 void (*unregister_event
)(struct mem_cgroup
*memcg
,
173 struct eventfd_ctx
*eventfd
);
175 * All fields below needed to unregister event when
176 * userspace closes eventfd.
179 wait_queue_head_t
*wqh
;
181 struct work_struct remove
;
184 static void mem_cgroup_threshold(struct mem_cgroup
*memcg
);
185 static void mem_cgroup_oom_notify(struct mem_cgroup
*memcg
);
187 /* Stuffs for move charges at task migration. */
189 * Types of charges to be moved.
191 #define MOVE_ANON 0x1U
192 #define MOVE_FILE 0x2U
193 #define MOVE_MASK (MOVE_ANON | MOVE_FILE)
195 /* "mc" and its members are protected by cgroup_mutex */
196 static struct move_charge_struct
{
197 spinlock_t lock
; /* for from, to */
198 struct mem_cgroup
*from
;
199 struct mem_cgroup
*to
;
201 unsigned long precharge
;
202 unsigned long moved_charge
;
203 unsigned long moved_swap
;
204 struct task_struct
*moving_task
; /* a task moving charges */
205 wait_queue_head_t waitq
; /* a waitq for other context */
207 .lock
= __SPIN_LOCK_UNLOCKED(mc
.lock
),
208 .waitq
= __WAIT_QUEUE_HEAD_INITIALIZER(mc
.waitq
),
212 * Maximum loops in mem_cgroup_hierarchical_reclaim(), used for soft
213 * limit reclaim to prevent infinite loops, if they ever occur.
215 #define MEM_CGROUP_MAX_RECLAIM_LOOPS 100
216 #define MEM_CGROUP_MAX_SOFT_LIMIT_RECLAIM_LOOPS 2
219 MEM_CGROUP_CHARGE_TYPE_CACHE
= 0,
220 MEM_CGROUP_CHARGE_TYPE_ANON
,
221 MEM_CGROUP_CHARGE_TYPE_SWAPOUT
, /* for accounting swapcache */
222 MEM_CGROUP_CHARGE_TYPE_DROP
, /* a page was unused swap cache */
226 /* for encoding cft->private value on file */
234 #define MEMFILE_PRIVATE(x, val) ((x) << 16 | (val))
235 #define MEMFILE_TYPE(val) ((val) >> 16 & 0xffff)
236 #define MEMFILE_ATTR(val) ((val) & 0xffff)
237 /* Used for OOM nofiier */
238 #define OOM_CONTROL (0)
241 * The memcg_create_mutex will be held whenever a new cgroup is created.
242 * As a consequence, any change that needs to protect against new child cgroups
243 * appearing has to hold it as well.
245 static DEFINE_MUTEX(memcg_create_mutex
);
247 /* Some nice accessors for the vmpressure. */
248 struct vmpressure
*memcg_to_vmpressure(struct mem_cgroup
*memcg
)
251 memcg
= root_mem_cgroup
;
252 return &memcg
->vmpressure
;
255 struct cgroup_subsys_state
*vmpressure_to_css(struct vmpressure
*vmpr
)
257 return &container_of(vmpr
, struct mem_cgroup
, vmpressure
)->css
;
260 static inline bool mem_cgroup_is_root(struct mem_cgroup
*memcg
)
262 return (memcg
== root_mem_cgroup
);
266 * We restrict the id in the range of [1, 65535], so it can fit into
269 #define MEM_CGROUP_ID_MAX USHRT_MAX
271 static inline unsigned short mem_cgroup_id(struct mem_cgroup
*memcg
)
273 return memcg
->css
.id
;
277 * A helper function to get mem_cgroup from ID. must be called under
278 * rcu_read_lock(). The caller is responsible for calling
279 * css_tryget_online() if the mem_cgroup is used for charging. (dropping
280 * refcnt from swap can be called against removed memcg.)
282 static inline struct mem_cgroup
*mem_cgroup_from_id(unsigned short id
)
284 struct cgroup_subsys_state
*css
;
286 css
= css_from_id(id
, &memory_cgrp_subsys
);
287 return mem_cgroup_from_css(css
);
290 /* Writing them here to avoid exposing memcg's inner layout */
291 #if defined(CONFIG_INET) && defined(CONFIG_MEMCG_KMEM)
293 void sock_update_memcg(struct sock
*sk
)
295 if (mem_cgroup_sockets_enabled
) {
296 struct mem_cgroup
*memcg
;
297 struct cg_proto
*cg_proto
;
299 BUG_ON(!sk
->sk_prot
->proto_cgroup
);
301 /* Socket cloning can throw us here with sk_cgrp already
302 * filled. It won't however, necessarily happen from
303 * process context. So the test for root memcg given
304 * the current task's memcg won't help us in this case.
306 * Respecting the original socket's memcg is a better
307 * decision in this case.
310 BUG_ON(mem_cgroup_is_root(sk
->sk_cgrp
->memcg
));
311 css_get(&sk
->sk_cgrp
->memcg
->css
);
316 memcg
= mem_cgroup_from_task(current
);
317 cg_proto
= sk
->sk_prot
->proto_cgroup(memcg
);
318 if (cg_proto
&& test_bit(MEMCG_SOCK_ACTIVE
, &cg_proto
->flags
) &&
319 css_tryget_online(&memcg
->css
)) {
320 sk
->sk_cgrp
= cg_proto
;
325 EXPORT_SYMBOL(sock_update_memcg
);
327 void sock_release_memcg(struct sock
*sk
)
329 if (mem_cgroup_sockets_enabled
&& sk
->sk_cgrp
) {
330 struct mem_cgroup
*memcg
;
331 WARN_ON(!sk
->sk_cgrp
->memcg
);
332 memcg
= sk
->sk_cgrp
->memcg
;
333 css_put(&sk
->sk_cgrp
->memcg
->css
);
337 struct cg_proto
*tcp_proto_cgroup(struct mem_cgroup
*memcg
)
339 if (!memcg
|| mem_cgroup_is_root(memcg
))
342 return &memcg
->tcp_mem
;
344 EXPORT_SYMBOL(tcp_proto_cgroup
);
348 #ifdef CONFIG_MEMCG_KMEM
350 * This will be the memcg's index in each cache's ->memcg_params.memcg_caches.
351 * The main reason for not using cgroup id for this:
352 * this works better in sparse environments, where we have a lot of memcgs,
353 * but only a few kmem-limited. Or also, if we have, for instance, 200
354 * memcgs, and none but the 200th is kmem-limited, we'd have to have a
355 * 200 entry array for that.
357 * The current size of the caches array is stored in memcg_nr_cache_ids. It
358 * will double each time we have to increase it.
360 static DEFINE_IDA(memcg_cache_ida
);
361 int memcg_nr_cache_ids
;
363 /* Protects memcg_nr_cache_ids */
364 static DECLARE_RWSEM(memcg_cache_ids_sem
);
366 void memcg_get_cache_ids(void)
368 down_read(&memcg_cache_ids_sem
);
371 void memcg_put_cache_ids(void)
373 up_read(&memcg_cache_ids_sem
);
377 * MIN_SIZE is different than 1, because we would like to avoid going through
378 * the alloc/free process all the time. In a small machine, 4 kmem-limited
379 * cgroups is a reasonable guess. In the future, it could be a parameter or
380 * tunable, but that is strictly not necessary.
382 * MAX_SIZE should be as large as the number of cgrp_ids. Ideally, we could get
383 * this constant directly from cgroup, but it is understandable that this is
384 * better kept as an internal representation in cgroup.c. In any case, the
385 * cgrp_id space is not getting any smaller, and we don't have to necessarily
386 * increase ours as well if it increases.
388 #define MEMCG_CACHES_MIN_SIZE 4
389 #define MEMCG_CACHES_MAX_SIZE MEM_CGROUP_ID_MAX
392 * A lot of the calls to the cache allocation functions are expected to be
393 * inlined by the compiler. Since the calls to memcg_kmem_get_cache are
394 * conditional to this static branch, we'll have to allow modules that does
395 * kmem_cache_alloc and the such to see this symbol as well
397 struct static_key memcg_kmem_enabled_key
;
398 EXPORT_SYMBOL(memcg_kmem_enabled_key
);
400 #endif /* CONFIG_MEMCG_KMEM */
402 static struct mem_cgroup_per_zone
*
403 mem_cgroup_zone_zoneinfo(struct mem_cgroup
*memcg
, struct zone
*zone
)
405 int nid
= zone_to_nid(zone
);
406 int zid
= zone_idx(zone
);
408 return &memcg
->nodeinfo
[nid
]->zoneinfo
[zid
];
412 * mem_cgroup_css_from_page - css of the memcg associated with a page
413 * @page: page of interest
415 * If memcg is bound to the default hierarchy, css of the memcg associated
416 * with @page is returned. The returned css remains associated with @page
417 * until it is released.
419 * If memcg is bound to a traditional hierarchy, the css of root_mem_cgroup
422 * XXX: The above description of behavior on the default hierarchy isn't
423 * strictly true yet as replace_page_cache_page() can modify the
424 * association before @page is released even on the default hierarchy;
425 * however, the current and planned usages don't mix the the two functions
426 * and replace_page_cache_page() will soon be updated to make the invariant
429 struct cgroup_subsys_state
*mem_cgroup_css_from_page(struct page
*page
)
431 struct mem_cgroup
*memcg
;
435 memcg
= page
->mem_cgroup
;
437 if (!memcg
|| !cgroup_on_dfl(memcg
->css
.cgroup
))
438 memcg
= root_mem_cgroup
;
445 * page_cgroup_ino - return inode number of the memcg a page is charged to
448 * Look up the closest online ancestor of the memory cgroup @page is charged to
449 * and return its inode number or 0 if @page is not charged to any cgroup. It
450 * is safe to call this function without holding a reference to @page.
452 * Note, this function is inherently racy, because there is nothing to prevent
453 * the cgroup inode from getting torn down and potentially reallocated a moment
454 * after page_cgroup_ino() returns, so it only should be used by callers that
455 * do not care (such as procfs interfaces).
457 ino_t
page_cgroup_ino(struct page
*page
)
459 struct mem_cgroup
*memcg
;
460 unsigned long ino
= 0;
463 memcg
= READ_ONCE(page
->mem_cgroup
);
464 while (memcg
&& !(memcg
->css
.flags
& CSS_ONLINE
))
465 memcg
= parent_mem_cgroup(memcg
);
467 ino
= cgroup_ino(memcg
->css
.cgroup
);
472 static struct mem_cgroup_per_zone
*
473 mem_cgroup_page_zoneinfo(struct mem_cgroup
*memcg
, struct page
*page
)
475 int nid
= page_to_nid(page
);
476 int zid
= page_zonenum(page
);
478 return &memcg
->nodeinfo
[nid
]->zoneinfo
[zid
];
481 static struct mem_cgroup_tree_per_zone
*
482 soft_limit_tree_node_zone(int nid
, int zid
)
484 return &soft_limit_tree
.rb_tree_per_node
[nid
]->rb_tree_per_zone
[zid
];
487 static struct mem_cgroup_tree_per_zone
*
488 soft_limit_tree_from_page(struct page
*page
)
490 int nid
= page_to_nid(page
);
491 int zid
= page_zonenum(page
);
493 return &soft_limit_tree
.rb_tree_per_node
[nid
]->rb_tree_per_zone
[zid
];
496 static void __mem_cgroup_insert_exceeded(struct mem_cgroup_per_zone
*mz
,
497 struct mem_cgroup_tree_per_zone
*mctz
,
498 unsigned long new_usage_in_excess
)
500 struct rb_node
**p
= &mctz
->rb_root
.rb_node
;
501 struct rb_node
*parent
= NULL
;
502 struct mem_cgroup_per_zone
*mz_node
;
507 mz
->usage_in_excess
= new_usage_in_excess
;
508 if (!mz
->usage_in_excess
)
512 mz_node
= rb_entry(parent
, struct mem_cgroup_per_zone
,
514 if (mz
->usage_in_excess
< mz_node
->usage_in_excess
)
517 * We can't avoid mem cgroups that are over their soft
518 * limit by the same amount
520 else if (mz
->usage_in_excess
>= mz_node
->usage_in_excess
)
523 rb_link_node(&mz
->tree_node
, parent
, p
);
524 rb_insert_color(&mz
->tree_node
, &mctz
->rb_root
);
528 static void __mem_cgroup_remove_exceeded(struct mem_cgroup_per_zone
*mz
,
529 struct mem_cgroup_tree_per_zone
*mctz
)
533 rb_erase(&mz
->tree_node
, &mctz
->rb_root
);
537 static void mem_cgroup_remove_exceeded(struct mem_cgroup_per_zone
*mz
,
538 struct mem_cgroup_tree_per_zone
*mctz
)
542 spin_lock_irqsave(&mctz
->lock
, flags
);
543 __mem_cgroup_remove_exceeded(mz
, mctz
);
544 spin_unlock_irqrestore(&mctz
->lock
, flags
);
547 static unsigned long soft_limit_excess(struct mem_cgroup
*memcg
)
549 unsigned long nr_pages
= page_counter_read(&memcg
->memory
);
550 unsigned long soft_limit
= READ_ONCE(memcg
->soft_limit
);
551 unsigned long excess
= 0;
553 if (nr_pages
> soft_limit
)
554 excess
= nr_pages
- soft_limit
;
559 static void mem_cgroup_update_tree(struct mem_cgroup
*memcg
, struct page
*page
)
561 unsigned long excess
;
562 struct mem_cgroup_per_zone
*mz
;
563 struct mem_cgroup_tree_per_zone
*mctz
;
565 mctz
= soft_limit_tree_from_page(page
);
567 * Necessary to update all ancestors when hierarchy is used.
568 * because their event counter is not touched.
570 for (; memcg
; memcg
= parent_mem_cgroup(memcg
)) {
571 mz
= mem_cgroup_page_zoneinfo(memcg
, page
);
572 excess
= soft_limit_excess(memcg
);
574 * We have to update the tree if mz is on RB-tree or
575 * mem is over its softlimit.
577 if (excess
|| mz
->on_tree
) {
580 spin_lock_irqsave(&mctz
->lock
, flags
);
581 /* if on-tree, remove it */
583 __mem_cgroup_remove_exceeded(mz
, mctz
);
585 * Insert again. mz->usage_in_excess will be updated.
586 * If excess is 0, no tree ops.
588 __mem_cgroup_insert_exceeded(mz
, mctz
, excess
);
589 spin_unlock_irqrestore(&mctz
->lock
, flags
);
594 static void mem_cgroup_remove_from_trees(struct mem_cgroup
*memcg
)
596 struct mem_cgroup_tree_per_zone
*mctz
;
597 struct mem_cgroup_per_zone
*mz
;
601 for (zid
= 0; zid
< MAX_NR_ZONES
; zid
++) {
602 mz
= &memcg
->nodeinfo
[nid
]->zoneinfo
[zid
];
603 mctz
= soft_limit_tree_node_zone(nid
, zid
);
604 mem_cgroup_remove_exceeded(mz
, mctz
);
609 static struct mem_cgroup_per_zone
*
610 __mem_cgroup_largest_soft_limit_node(struct mem_cgroup_tree_per_zone
*mctz
)
612 struct rb_node
*rightmost
= NULL
;
613 struct mem_cgroup_per_zone
*mz
;
617 rightmost
= rb_last(&mctz
->rb_root
);
619 goto done
; /* Nothing to reclaim from */
621 mz
= rb_entry(rightmost
, struct mem_cgroup_per_zone
, tree_node
);
623 * Remove the node now but someone else can add it back,
624 * we will to add it back at the end of reclaim to its correct
625 * position in the tree.
627 __mem_cgroup_remove_exceeded(mz
, mctz
);
628 if (!soft_limit_excess(mz
->memcg
) ||
629 !css_tryget_online(&mz
->memcg
->css
))
635 static struct mem_cgroup_per_zone
*
636 mem_cgroup_largest_soft_limit_node(struct mem_cgroup_tree_per_zone
*mctz
)
638 struct mem_cgroup_per_zone
*mz
;
640 spin_lock_irq(&mctz
->lock
);
641 mz
= __mem_cgroup_largest_soft_limit_node(mctz
);
642 spin_unlock_irq(&mctz
->lock
);
647 * Return page count for single (non recursive) @memcg.
649 * Implementation Note: reading percpu statistics for memcg.
651 * Both of vmstat[] and percpu_counter has threshold and do periodic
652 * synchronization to implement "quick" read. There are trade-off between
653 * reading cost and precision of value. Then, we may have a chance to implement
654 * a periodic synchronization of counter in memcg's counter.
656 * But this _read() function is used for user interface now. The user accounts
657 * memory usage by memory cgroup and he _always_ requires exact value because
658 * he accounts memory. Even if we provide quick-and-fuzzy read, we always
659 * have to visit all online cpus and make sum. So, for now, unnecessary
660 * synchronization is not implemented. (just implemented for cpu hotplug)
662 * If there are kernel internal actions which can make use of some not-exact
663 * value, and reading all cpu value can be performance bottleneck in some
664 * common workload, threshold and synchronization as vmstat[] should be
668 mem_cgroup_read_stat(struct mem_cgroup
*memcg
, enum mem_cgroup_stat_index idx
)
673 /* Per-cpu values can be negative, use a signed accumulator */
674 for_each_possible_cpu(cpu
)
675 val
+= per_cpu(memcg
->stat
->count
[idx
], cpu
);
677 * Summing races with updates, so val may be negative. Avoid exposing
678 * transient negative values.
685 static unsigned long mem_cgroup_read_events(struct mem_cgroup
*memcg
,
686 enum mem_cgroup_events_index idx
)
688 unsigned long val
= 0;
691 for_each_possible_cpu(cpu
)
692 val
+= per_cpu(memcg
->stat
->events
[idx
], cpu
);
696 static void mem_cgroup_charge_statistics(struct mem_cgroup
*memcg
,
701 * Here, RSS means 'mapped anon' and anon's SwapCache. Shmem/tmpfs is
702 * counted as CACHE even if it's on ANON LRU.
705 __this_cpu_add(memcg
->stat
->count
[MEM_CGROUP_STAT_RSS
],
708 __this_cpu_add(memcg
->stat
->count
[MEM_CGROUP_STAT_CACHE
],
711 if (PageTransHuge(page
))
712 __this_cpu_add(memcg
->stat
->count
[MEM_CGROUP_STAT_RSS_HUGE
],
715 /* pagein of a big page is an event. So, ignore page size */
717 __this_cpu_inc(memcg
->stat
->events
[MEM_CGROUP_EVENTS_PGPGIN
]);
719 __this_cpu_inc(memcg
->stat
->events
[MEM_CGROUP_EVENTS_PGPGOUT
]);
720 nr_pages
= -nr_pages
; /* for event */
723 __this_cpu_add(memcg
->stat
->nr_page_events
, nr_pages
);
726 static unsigned long mem_cgroup_node_nr_lru_pages(struct mem_cgroup
*memcg
,
728 unsigned int lru_mask
)
730 unsigned long nr
= 0;
733 VM_BUG_ON((unsigned)nid
>= nr_node_ids
);
735 for (zid
= 0; zid
< MAX_NR_ZONES
; zid
++) {
736 struct mem_cgroup_per_zone
*mz
;
740 if (!(BIT(lru
) & lru_mask
))
742 mz
= &memcg
->nodeinfo
[nid
]->zoneinfo
[zid
];
743 nr
+= mz
->lru_size
[lru
];
749 static unsigned long mem_cgroup_nr_lru_pages(struct mem_cgroup
*memcg
,
750 unsigned int lru_mask
)
752 unsigned long nr
= 0;
755 for_each_node_state(nid
, N_MEMORY
)
756 nr
+= mem_cgroup_node_nr_lru_pages(memcg
, nid
, lru_mask
);
760 static bool mem_cgroup_event_ratelimit(struct mem_cgroup
*memcg
,
761 enum mem_cgroup_events_target target
)
763 unsigned long val
, next
;
765 val
= __this_cpu_read(memcg
->stat
->nr_page_events
);
766 next
= __this_cpu_read(memcg
->stat
->targets
[target
]);
767 /* from time_after() in jiffies.h */
768 if ((long)next
- (long)val
< 0) {
770 case MEM_CGROUP_TARGET_THRESH
:
771 next
= val
+ THRESHOLDS_EVENTS_TARGET
;
773 case MEM_CGROUP_TARGET_SOFTLIMIT
:
774 next
= val
+ SOFTLIMIT_EVENTS_TARGET
;
776 case MEM_CGROUP_TARGET_NUMAINFO
:
777 next
= val
+ NUMAINFO_EVENTS_TARGET
;
782 __this_cpu_write(memcg
->stat
->targets
[target
], next
);
789 * Check events in order.
792 static void memcg_check_events(struct mem_cgroup
*memcg
, struct page
*page
)
794 /* threshold event is triggered in finer grain than soft limit */
795 if (unlikely(mem_cgroup_event_ratelimit(memcg
,
796 MEM_CGROUP_TARGET_THRESH
))) {
798 bool do_numainfo __maybe_unused
;
800 do_softlimit
= mem_cgroup_event_ratelimit(memcg
,
801 MEM_CGROUP_TARGET_SOFTLIMIT
);
803 do_numainfo
= mem_cgroup_event_ratelimit(memcg
,
804 MEM_CGROUP_TARGET_NUMAINFO
);
806 mem_cgroup_threshold(memcg
);
807 if (unlikely(do_softlimit
))
808 mem_cgroup_update_tree(memcg
, page
);
810 if (unlikely(do_numainfo
))
811 atomic_inc(&memcg
->numainfo_events
);
816 struct mem_cgroup
*mem_cgroup_from_task(struct task_struct
*p
)
819 * mm_update_next_owner() may clear mm->owner to NULL
820 * if it races with swapoff, page migration, etc.
821 * So this can be called with p == NULL.
826 return mem_cgroup_from_css(task_css(p
, memory_cgrp_id
));
828 EXPORT_SYMBOL(mem_cgroup_from_task
);
830 static struct mem_cgroup
*get_mem_cgroup_from_mm(struct mm_struct
*mm
)
832 struct mem_cgroup
*memcg
= NULL
;
837 * Page cache insertions can happen withou an
838 * actual mm context, e.g. during disk probing
839 * on boot, loopback IO, acct() writes etc.
842 memcg
= root_mem_cgroup
;
844 memcg
= mem_cgroup_from_task(rcu_dereference(mm
->owner
));
845 if (unlikely(!memcg
))
846 memcg
= root_mem_cgroup
;
848 } while (!css_tryget_online(&memcg
->css
));
854 * mem_cgroup_iter - iterate over memory cgroup hierarchy
855 * @root: hierarchy root
856 * @prev: previously returned memcg, NULL on first invocation
857 * @reclaim: cookie for shared reclaim walks, NULL for full walks
859 * Returns references to children of the hierarchy below @root, or
860 * @root itself, or %NULL after a full round-trip.
862 * Caller must pass the return value in @prev on subsequent
863 * invocations for reference counting, or use mem_cgroup_iter_break()
864 * to cancel a hierarchy walk before the round-trip is complete.
866 * Reclaimers can specify a zone and a priority level in @reclaim to
867 * divide up the memcgs in the hierarchy among all concurrent
868 * reclaimers operating on the same zone and priority.
870 struct mem_cgroup
*mem_cgroup_iter(struct mem_cgroup
*root
,
871 struct mem_cgroup
*prev
,
872 struct mem_cgroup_reclaim_cookie
*reclaim
)
874 struct mem_cgroup_reclaim_iter
*uninitialized_var(iter
);
875 struct cgroup_subsys_state
*css
= NULL
;
876 struct mem_cgroup
*memcg
= NULL
;
877 struct mem_cgroup
*pos
= NULL
;
879 if (mem_cgroup_disabled())
883 root
= root_mem_cgroup
;
885 if (prev
&& !reclaim
)
888 if (!root
->use_hierarchy
&& root
!= root_mem_cgroup
) {
897 struct mem_cgroup_per_zone
*mz
;
899 mz
= mem_cgroup_zone_zoneinfo(root
, reclaim
->zone
);
900 iter
= &mz
->iter
[reclaim
->priority
];
902 if (prev
&& reclaim
->generation
!= iter
->generation
)
906 pos
= READ_ONCE(iter
->position
);
908 * A racing update may change the position and
909 * put the last reference, hence css_tryget(),
910 * or retry to see the updated position.
912 } while (pos
&& !css_tryget(&pos
->css
));
919 css
= css_next_descendant_pre(css
, &root
->css
);
922 * Reclaimers share the hierarchy walk, and a
923 * new one might jump in right at the end of
924 * the hierarchy - make sure they see at least
925 * one group and restart from the beginning.
933 * Verify the css and acquire a reference. The root
934 * is provided by the caller, so we know it's alive
935 * and kicking, and don't take an extra reference.
937 memcg
= mem_cgroup_from_css(css
);
939 if (css
== &root
->css
)
942 if (css_tryget(css
)) {
944 * Make sure the memcg is initialized:
945 * mem_cgroup_css_online() orders the the
946 * initialization against setting the flag.
948 if (smp_load_acquire(&memcg
->initialized
))
958 if (cmpxchg(&iter
->position
, pos
, memcg
) == pos
) {
960 css_get(&memcg
->css
);
966 * pairs with css_tryget when dereferencing iter->position
975 reclaim
->generation
= iter
->generation
;
981 if (prev
&& prev
!= root
)
988 * mem_cgroup_iter_break - abort a hierarchy walk prematurely
989 * @root: hierarchy root
990 * @prev: last visited hierarchy member as returned by mem_cgroup_iter()
992 void mem_cgroup_iter_break(struct mem_cgroup
*root
,
993 struct mem_cgroup
*prev
)
996 root
= root_mem_cgroup
;
997 if (prev
&& prev
!= root
)
1002 * Iteration constructs for visiting all cgroups (under a tree). If
1003 * loops are exited prematurely (break), mem_cgroup_iter_break() must
1004 * be used for reference counting.
1006 #define for_each_mem_cgroup_tree(iter, root) \
1007 for (iter = mem_cgroup_iter(root, NULL, NULL); \
1009 iter = mem_cgroup_iter(root, iter, NULL))
1011 #define for_each_mem_cgroup(iter) \
1012 for (iter = mem_cgroup_iter(NULL, NULL, NULL); \
1014 iter = mem_cgroup_iter(NULL, iter, NULL))
1017 * mem_cgroup_zone_lruvec - get the lru list vector for a zone and memcg
1018 * @zone: zone of the wanted lruvec
1019 * @memcg: memcg of the wanted lruvec
1021 * Returns the lru list vector holding pages for the given @zone and
1022 * @mem. This can be the global zone lruvec, if the memory controller
1025 struct lruvec
*mem_cgroup_zone_lruvec(struct zone
*zone
,
1026 struct mem_cgroup
*memcg
)
1028 struct mem_cgroup_per_zone
*mz
;
1029 struct lruvec
*lruvec
;
1031 if (mem_cgroup_disabled()) {
1032 lruvec
= &zone
->lruvec
;
1036 mz
= mem_cgroup_zone_zoneinfo(memcg
, zone
);
1037 lruvec
= &mz
->lruvec
;
1040 * Since a node can be onlined after the mem_cgroup was created,
1041 * we have to be prepared to initialize lruvec->zone here;
1042 * and if offlined then reonlined, we need to reinitialize it.
1044 if (unlikely(lruvec
->zone
!= zone
))
1045 lruvec
->zone
= zone
;
1050 * mem_cgroup_page_lruvec - return lruvec for isolating/putting an LRU page
1052 * @zone: zone of the page
1054 * This function is only safe when following the LRU page isolation
1055 * and putback protocol: the LRU lock must be held, and the page must
1056 * either be PageLRU() or the caller must have isolated/allocated it.
1058 struct lruvec
*mem_cgroup_page_lruvec(struct page
*page
, struct zone
*zone
)
1060 struct mem_cgroup_per_zone
*mz
;
1061 struct mem_cgroup
*memcg
;
1062 struct lruvec
*lruvec
;
1064 if (mem_cgroup_disabled()) {
1065 lruvec
= &zone
->lruvec
;
1069 memcg
= page
->mem_cgroup
;
1071 * Swapcache readahead pages are added to the LRU - and
1072 * possibly migrated - before they are charged.
1075 memcg
= root_mem_cgroup
;
1077 mz
= mem_cgroup_page_zoneinfo(memcg
, page
);
1078 lruvec
= &mz
->lruvec
;
1081 * Since a node can be onlined after the mem_cgroup was created,
1082 * we have to be prepared to initialize lruvec->zone here;
1083 * and if offlined then reonlined, we need to reinitialize it.
1085 if (unlikely(lruvec
->zone
!= zone
))
1086 lruvec
->zone
= zone
;
1091 * mem_cgroup_update_lru_size - account for adding or removing an lru page
1092 * @lruvec: mem_cgroup per zone lru vector
1093 * @lru: index of lru list the page is sitting on
1094 * @nr_pages: positive when adding or negative when removing
1096 * This function must be called when a page is added to or removed from an
1099 void mem_cgroup_update_lru_size(struct lruvec
*lruvec
, enum lru_list lru
,
1102 struct mem_cgroup_per_zone
*mz
;
1103 unsigned long *lru_size
;
1105 if (mem_cgroup_disabled())
1108 mz
= container_of(lruvec
, struct mem_cgroup_per_zone
, lruvec
);
1109 lru_size
= mz
->lru_size
+ lru
;
1110 *lru_size
+= nr_pages
;
1111 VM_BUG_ON((long)(*lru_size
) < 0);
1114 bool task_in_mem_cgroup(struct task_struct
*task
, struct mem_cgroup
*memcg
)
1116 struct mem_cgroup
*task_memcg
;
1117 struct task_struct
*p
;
1120 p
= find_lock_task_mm(task
);
1122 task_memcg
= get_mem_cgroup_from_mm(p
->mm
);
1126 * All threads may have already detached their mm's, but the oom
1127 * killer still needs to detect if they have already been oom
1128 * killed to prevent needlessly killing additional tasks.
1131 task_memcg
= mem_cgroup_from_task(task
);
1132 css_get(&task_memcg
->css
);
1135 ret
= mem_cgroup_is_descendant(task_memcg
, memcg
);
1136 css_put(&task_memcg
->css
);
1140 #define mem_cgroup_from_counter(counter, member) \
1141 container_of(counter, struct mem_cgroup, member)
1144 * mem_cgroup_margin - calculate chargeable space of a memory cgroup
1145 * @memcg: the memory cgroup
1147 * Returns the maximum amount of memory @mem can be charged with, in
1150 static unsigned long mem_cgroup_margin(struct mem_cgroup
*memcg
)
1152 unsigned long margin
= 0;
1153 unsigned long count
;
1154 unsigned long limit
;
1156 count
= page_counter_read(&memcg
->memory
);
1157 limit
= READ_ONCE(memcg
->memory
.limit
);
1159 margin
= limit
- count
;
1161 if (do_swap_account
) {
1162 count
= page_counter_read(&memcg
->memsw
);
1163 limit
= READ_ONCE(memcg
->memsw
.limit
);
1165 margin
= min(margin
, limit
- count
);
1172 * A routine for checking "mem" is under move_account() or not.
1174 * Checking a cgroup is mc.from or mc.to or under hierarchy of
1175 * moving cgroups. This is for waiting at high-memory pressure
1178 static bool mem_cgroup_under_move(struct mem_cgroup
*memcg
)
1180 struct mem_cgroup
*from
;
1181 struct mem_cgroup
*to
;
1184 * Unlike task_move routines, we access mc.to, mc.from not under
1185 * mutual exclusion by cgroup_mutex. Here, we take spinlock instead.
1187 spin_lock(&mc
.lock
);
1193 ret
= mem_cgroup_is_descendant(from
, memcg
) ||
1194 mem_cgroup_is_descendant(to
, memcg
);
1196 spin_unlock(&mc
.lock
);
1200 static bool mem_cgroup_wait_acct_move(struct mem_cgroup
*memcg
)
1202 if (mc
.moving_task
&& current
!= mc
.moving_task
) {
1203 if (mem_cgroup_under_move(memcg
)) {
1205 prepare_to_wait(&mc
.waitq
, &wait
, TASK_INTERRUPTIBLE
);
1206 /* moving charge context might have finished. */
1209 finish_wait(&mc
.waitq
, &wait
);
1216 #define K(x) ((x) << (PAGE_SHIFT-10))
1218 * mem_cgroup_print_oom_info: Print OOM information relevant to memory controller.
1219 * @memcg: The memory cgroup that went over limit
1220 * @p: Task that is going to be killed
1222 * NOTE: @memcg and @p's mem_cgroup can be different when hierarchy is
1225 void mem_cgroup_print_oom_info(struct mem_cgroup
*memcg
, struct task_struct
*p
)
1227 /* oom_info_lock ensures that parallel ooms do not interleave */
1228 static DEFINE_MUTEX(oom_info_lock
);
1229 struct mem_cgroup
*iter
;
1232 mutex_lock(&oom_info_lock
);
1236 pr_info("Task in ");
1237 pr_cont_cgroup_path(task_cgroup(p
, memory_cgrp_id
));
1238 pr_cont(" killed as a result of limit of ");
1240 pr_info("Memory limit reached of cgroup ");
1243 pr_cont_cgroup_path(memcg
->css
.cgroup
);
1248 pr_info("memory: usage %llukB, limit %llukB, failcnt %lu\n",
1249 K((u64
)page_counter_read(&memcg
->memory
)),
1250 K((u64
)memcg
->memory
.limit
), memcg
->memory
.failcnt
);
1251 pr_info("memory+swap: usage %llukB, limit %llukB, failcnt %lu\n",
1252 K((u64
)page_counter_read(&memcg
->memsw
)),
1253 K((u64
)memcg
->memsw
.limit
), memcg
->memsw
.failcnt
);
1254 pr_info("kmem: usage %llukB, limit %llukB, failcnt %lu\n",
1255 K((u64
)page_counter_read(&memcg
->kmem
)),
1256 K((u64
)memcg
->kmem
.limit
), memcg
->kmem
.failcnt
);
1258 for_each_mem_cgroup_tree(iter
, memcg
) {
1259 pr_info("Memory cgroup stats for ");
1260 pr_cont_cgroup_path(iter
->css
.cgroup
);
1263 for (i
= 0; i
< MEM_CGROUP_STAT_NSTATS
; i
++) {
1264 if (i
== MEM_CGROUP_STAT_SWAP
&& !do_swap_account
)
1266 pr_cont(" %s:%luKB", mem_cgroup_stat_names
[i
],
1267 K(mem_cgroup_read_stat(iter
, i
)));
1270 for (i
= 0; i
< NR_LRU_LISTS
; i
++)
1271 pr_cont(" %s:%luKB", mem_cgroup_lru_names
[i
],
1272 K(mem_cgroup_nr_lru_pages(iter
, BIT(i
))));
1276 mutex_unlock(&oom_info_lock
);
1280 * This function returns the number of memcg under hierarchy tree. Returns
1281 * 1(self count) if no children.
1283 static int mem_cgroup_count_children(struct mem_cgroup
*memcg
)
1286 struct mem_cgroup
*iter
;
1288 for_each_mem_cgroup_tree(iter
, memcg
)
1294 * Return the memory (and swap, if configured) limit for a memcg.
1296 static unsigned long mem_cgroup_get_limit(struct mem_cgroup
*memcg
)
1298 unsigned long limit
;
1300 limit
= memcg
->memory
.limit
;
1301 if (mem_cgroup_swappiness(memcg
)) {
1302 unsigned long memsw_limit
;
1304 memsw_limit
= memcg
->memsw
.limit
;
1305 limit
= min(limit
+ total_swap_pages
, memsw_limit
);
1310 static void mem_cgroup_out_of_memory(struct mem_cgroup
*memcg
, gfp_t gfp_mask
,
1313 struct oom_control oc
= {
1316 .gfp_mask
= gfp_mask
,
1319 struct mem_cgroup
*iter
;
1320 unsigned long chosen_points
= 0;
1321 unsigned long totalpages
;
1322 unsigned int points
= 0;
1323 struct task_struct
*chosen
= NULL
;
1325 mutex_lock(&oom_lock
);
1328 * If current has a pending SIGKILL or is exiting, then automatically
1329 * select it. The goal is to allow it to allocate so that it may
1330 * quickly exit and free its memory.
1332 if (fatal_signal_pending(current
) || task_will_free_mem(current
)) {
1333 mark_oom_victim(current
);
1337 check_panic_on_oom(&oc
, CONSTRAINT_MEMCG
, memcg
);
1338 totalpages
= mem_cgroup_get_limit(memcg
) ? : 1;
1339 for_each_mem_cgroup_tree(iter
, memcg
) {
1340 struct css_task_iter it
;
1341 struct task_struct
*task
;
1343 css_task_iter_start(&iter
->css
, &it
);
1344 while ((task
= css_task_iter_next(&it
))) {
1345 switch (oom_scan_process_thread(&oc
, task
, totalpages
)) {
1346 case OOM_SCAN_SELECT
:
1348 put_task_struct(chosen
);
1350 chosen_points
= ULONG_MAX
;
1351 get_task_struct(chosen
);
1353 case OOM_SCAN_CONTINUE
:
1355 case OOM_SCAN_ABORT
:
1356 css_task_iter_end(&it
);
1357 mem_cgroup_iter_break(memcg
, iter
);
1359 put_task_struct(chosen
);
1364 points
= oom_badness(task
, memcg
, NULL
, totalpages
);
1365 if (!points
|| points
< chosen_points
)
1367 /* Prefer thread group leaders for display purposes */
1368 if (points
== chosen_points
&&
1369 thread_group_leader(chosen
))
1373 put_task_struct(chosen
);
1375 chosen_points
= points
;
1376 get_task_struct(chosen
);
1378 css_task_iter_end(&it
);
1382 points
= chosen_points
* 1000 / totalpages
;
1383 oom_kill_process(&oc
, chosen
, points
, totalpages
, memcg
,
1384 "Memory cgroup out of memory");
1387 mutex_unlock(&oom_lock
);
1390 #if MAX_NUMNODES > 1
1393 * test_mem_cgroup_node_reclaimable
1394 * @memcg: the target memcg
1395 * @nid: the node ID to be checked.
1396 * @noswap : specify true here if the user wants flle only information.
1398 * This function returns whether the specified memcg contains any
1399 * reclaimable pages on a node. Returns true if there are any reclaimable
1400 * pages in the node.
1402 static bool test_mem_cgroup_node_reclaimable(struct mem_cgroup
*memcg
,
1403 int nid
, bool noswap
)
1405 if (mem_cgroup_node_nr_lru_pages(memcg
, nid
, LRU_ALL_FILE
))
1407 if (noswap
|| !total_swap_pages
)
1409 if (mem_cgroup_node_nr_lru_pages(memcg
, nid
, LRU_ALL_ANON
))
1416 * Always updating the nodemask is not very good - even if we have an empty
1417 * list or the wrong list here, we can start from some node and traverse all
1418 * nodes based on the zonelist. So update the list loosely once per 10 secs.
1421 static void mem_cgroup_may_update_nodemask(struct mem_cgroup
*memcg
)
1425 * numainfo_events > 0 means there was at least NUMAINFO_EVENTS_TARGET
1426 * pagein/pageout changes since the last update.
1428 if (!atomic_read(&memcg
->numainfo_events
))
1430 if (atomic_inc_return(&memcg
->numainfo_updating
) > 1)
1433 /* make a nodemask where this memcg uses memory from */
1434 memcg
->scan_nodes
= node_states
[N_MEMORY
];
1436 for_each_node_mask(nid
, node_states
[N_MEMORY
]) {
1438 if (!test_mem_cgroup_node_reclaimable(memcg
, nid
, false))
1439 node_clear(nid
, memcg
->scan_nodes
);
1442 atomic_set(&memcg
->numainfo_events
, 0);
1443 atomic_set(&memcg
->numainfo_updating
, 0);
1447 * Selecting a node where we start reclaim from. Because what we need is just
1448 * reducing usage counter, start from anywhere is O,K. Considering
1449 * memory reclaim from current node, there are pros. and cons.
1451 * Freeing memory from current node means freeing memory from a node which
1452 * we'll use or we've used. So, it may make LRU bad. And if several threads
1453 * hit limits, it will see a contention on a node. But freeing from remote
1454 * node means more costs for memory reclaim because of memory latency.
1456 * Now, we use round-robin. Better algorithm is welcomed.
1458 int mem_cgroup_select_victim_node(struct mem_cgroup
*memcg
)
1462 mem_cgroup_may_update_nodemask(memcg
);
1463 node
= memcg
->last_scanned_node
;
1465 node
= next_node(node
, memcg
->scan_nodes
);
1466 if (node
== MAX_NUMNODES
)
1467 node
= first_node(memcg
->scan_nodes
);
1469 * We call this when we hit limit, not when pages are added to LRU.
1470 * No LRU may hold pages because all pages are UNEVICTABLE or
1471 * memcg is too small and all pages are not on LRU. In that case,
1472 * we use curret node.
1474 if (unlikely(node
== MAX_NUMNODES
))
1475 node
= numa_node_id();
1477 memcg
->last_scanned_node
= node
;
1481 int mem_cgroup_select_victim_node(struct mem_cgroup
*memcg
)
1487 static int mem_cgroup_soft_reclaim(struct mem_cgroup
*root_memcg
,
1490 unsigned long *total_scanned
)
1492 struct mem_cgroup
*victim
= NULL
;
1495 unsigned long excess
;
1496 unsigned long nr_scanned
;
1497 struct mem_cgroup_reclaim_cookie reclaim
= {
1502 excess
= soft_limit_excess(root_memcg
);
1505 victim
= mem_cgroup_iter(root_memcg
, victim
, &reclaim
);
1510 * If we have not been able to reclaim
1511 * anything, it might because there are
1512 * no reclaimable pages under this hierarchy
1517 * We want to do more targeted reclaim.
1518 * excess >> 2 is not to excessive so as to
1519 * reclaim too much, nor too less that we keep
1520 * coming back to reclaim from this cgroup
1522 if (total
>= (excess
>> 2) ||
1523 (loop
> MEM_CGROUP_MAX_RECLAIM_LOOPS
))
1528 total
+= mem_cgroup_shrink_node_zone(victim
, gfp_mask
, false,
1530 *total_scanned
+= nr_scanned
;
1531 if (!soft_limit_excess(root_memcg
))
1534 mem_cgroup_iter_break(root_memcg
, victim
);
1538 #ifdef CONFIG_LOCKDEP
1539 static struct lockdep_map memcg_oom_lock_dep_map
= {
1540 .name
= "memcg_oom_lock",
1544 static DEFINE_SPINLOCK(memcg_oom_lock
);
1547 * Check OOM-Killer is already running under our hierarchy.
1548 * If someone is running, return false.
1550 static bool mem_cgroup_oom_trylock(struct mem_cgroup
*memcg
)
1552 struct mem_cgroup
*iter
, *failed
= NULL
;
1554 spin_lock(&memcg_oom_lock
);
1556 for_each_mem_cgroup_tree(iter
, memcg
) {
1557 if (iter
->oom_lock
) {
1559 * this subtree of our hierarchy is already locked
1560 * so we cannot give a lock.
1563 mem_cgroup_iter_break(memcg
, iter
);
1566 iter
->oom_lock
= true;
1571 * OK, we failed to lock the whole subtree so we have
1572 * to clean up what we set up to the failing subtree
1574 for_each_mem_cgroup_tree(iter
, memcg
) {
1575 if (iter
== failed
) {
1576 mem_cgroup_iter_break(memcg
, iter
);
1579 iter
->oom_lock
= false;
1582 mutex_acquire(&memcg_oom_lock_dep_map
, 0, 1, _RET_IP_
);
1584 spin_unlock(&memcg_oom_lock
);
1589 static void mem_cgroup_oom_unlock(struct mem_cgroup
*memcg
)
1591 struct mem_cgroup
*iter
;
1593 spin_lock(&memcg_oom_lock
);
1594 mutex_release(&memcg_oom_lock_dep_map
, 1, _RET_IP_
);
1595 for_each_mem_cgroup_tree(iter
, memcg
)
1596 iter
->oom_lock
= false;
1597 spin_unlock(&memcg_oom_lock
);
1600 static void mem_cgroup_mark_under_oom(struct mem_cgroup
*memcg
)
1602 struct mem_cgroup
*iter
;
1604 spin_lock(&memcg_oom_lock
);
1605 for_each_mem_cgroup_tree(iter
, memcg
)
1607 spin_unlock(&memcg_oom_lock
);
1610 static void mem_cgroup_unmark_under_oom(struct mem_cgroup
*memcg
)
1612 struct mem_cgroup
*iter
;
1615 * When a new child is created while the hierarchy is under oom,
1616 * mem_cgroup_oom_lock() may not be called. Watch for underflow.
1618 spin_lock(&memcg_oom_lock
);
1619 for_each_mem_cgroup_tree(iter
, memcg
)
1620 if (iter
->under_oom
> 0)
1622 spin_unlock(&memcg_oom_lock
);
1625 static DECLARE_WAIT_QUEUE_HEAD(memcg_oom_waitq
);
1627 struct oom_wait_info
{
1628 struct mem_cgroup
*memcg
;
1632 static int memcg_oom_wake_function(wait_queue_t
*wait
,
1633 unsigned mode
, int sync
, void *arg
)
1635 struct mem_cgroup
*wake_memcg
= (struct mem_cgroup
*)arg
;
1636 struct mem_cgroup
*oom_wait_memcg
;
1637 struct oom_wait_info
*oom_wait_info
;
1639 oom_wait_info
= container_of(wait
, struct oom_wait_info
, wait
);
1640 oom_wait_memcg
= oom_wait_info
->memcg
;
1642 if (!mem_cgroup_is_descendant(wake_memcg
, oom_wait_memcg
) &&
1643 !mem_cgroup_is_descendant(oom_wait_memcg
, wake_memcg
))
1645 return autoremove_wake_function(wait
, mode
, sync
, arg
);
1648 static void memcg_oom_recover(struct mem_cgroup
*memcg
)
1651 * For the following lockless ->under_oom test, the only required
1652 * guarantee is that it must see the state asserted by an OOM when
1653 * this function is called as a result of userland actions
1654 * triggered by the notification of the OOM. This is trivially
1655 * achieved by invoking mem_cgroup_mark_under_oom() before
1656 * triggering notification.
1658 if (memcg
&& memcg
->under_oom
)
1659 __wake_up(&memcg_oom_waitq
, TASK_NORMAL
, 0, memcg
);
1662 static void mem_cgroup_oom(struct mem_cgroup
*memcg
, gfp_t mask
, int order
)
1664 if (!current
->memcg_oom
.may_oom
)
1667 * We are in the middle of the charge context here, so we
1668 * don't want to block when potentially sitting on a callstack
1669 * that holds all kinds of filesystem and mm locks.
1671 * Also, the caller may handle a failed allocation gracefully
1672 * (like optional page cache readahead) and so an OOM killer
1673 * invocation might not even be necessary.
1675 * That's why we don't do anything here except remember the
1676 * OOM context and then deal with it at the end of the page
1677 * fault when the stack is unwound, the locks are released,
1678 * and when we know whether the fault was overall successful.
1680 css_get(&memcg
->css
);
1681 current
->memcg_oom
.memcg
= memcg
;
1682 current
->memcg_oom
.gfp_mask
= mask
;
1683 current
->memcg_oom
.order
= order
;
1687 * mem_cgroup_oom_synchronize - complete memcg OOM handling
1688 * @handle: actually kill/wait or just clean up the OOM state
1690 * This has to be called at the end of a page fault if the memcg OOM
1691 * handler was enabled.
1693 * Memcg supports userspace OOM handling where failed allocations must
1694 * sleep on a waitqueue until the userspace task resolves the
1695 * situation. Sleeping directly in the charge context with all kinds
1696 * of locks held is not a good idea, instead we remember an OOM state
1697 * in the task and mem_cgroup_oom_synchronize() has to be called at
1698 * the end of the page fault to complete the OOM handling.
1700 * Returns %true if an ongoing memcg OOM situation was detected and
1701 * completed, %false otherwise.
1703 bool mem_cgroup_oom_synchronize(bool handle
)
1705 struct mem_cgroup
*memcg
= current
->memcg_oom
.memcg
;
1706 struct oom_wait_info owait
;
1709 /* OOM is global, do not handle */
1713 if (!handle
|| oom_killer_disabled
)
1716 owait
.memcg
= memcg
;
1717 owait
.wait
.flags
= 0;
1718 owait
.wait
.func
= memcg_oom_wake_function
;
1719 owait
.wait
.private = current
;
1720 INIT_LIST_HEAD(&owait
.wait
.task_list
);
1722 prepare_to_wait(&memcg_oom_waitq
, &owait
.wait
, TASK_KILLABLE
);
1723 mem_cgroup_mark_under_oom(memcg
);
1725 locked
= mem_cgroup_oom_trylock(memcg
);
1728 mem_cgroup_oom_notify(memcg
);
1730 if (locked
&& !memcg
->oom_kill_disable
) {
1731 mem_cgroup_unmark_under_oom(memcg
);
1732 finish_wait(&memcg_oom_waitq
, &owait
.wait
);
1733 mem_cgroup_out_of_memory(memcg
, current
->memcg_oom
.gfp_mask
,
1734 current
->memcg_oom
.order
);
1737 mem_cgroup_unmark_under_oom(memcg
);
1738 finish_wait(&memcg_oom_waitq
, &owait
.wait
);
1742 mem_cgroup_oom_unlock(memcg
);
1744 * There is no guarantee that an OOM-lock contender
1745 * sees the wakeups triggered by the OOM kill
1746 * uncharges. Wake any sleepers explicitely.
1748 memcg_oom_recover(memcg
);
1751 current
->memcg_oom
.memcg
= NULL
;
1752 css_put(&memcg
->css
);
1757 * mem_cgroup_begin_page_stat - begin a page state statistics transaction
1758 * @page: page that is going to change accounted state
1760 * This function must mark the beginning of an accounted page state
1761 * change to prevent double accounting when the page is concurrently
1762 * being moved to another memcg:
1764 * memcg = mem_cgroup_begin_page_stat(page);
1765 * if (TestClearPageState(page))
1766 * mem_cgroup_update_page_stat(memcg, state, -1);
1767 * mem_cgroup_end_page_stat(memcg);
1769 struct mem_cgroup
*mem_cgroup_begin_page_stat(struct page
*page
)
1771 struct mem_cgroup
*memcg
;
1772 unsigned long flags
;
1775 * The RCU lock is held throughout the transaction. The fast
1776 * path can get away without acquiring the memcg->move_lock
1777 * because page moving starts with an RCU grace period.
1779 * The RCU lock also protects the memcg from being freed when
1780 * the page state that is going to change is the only thing
1781 * preventing the page from being uncharged.
1782 * E.g. end-writeback clearing PageWriteback(), which allows
1783 * migration to go ahead and uncharge the page before the
1784 * account transaction might be complete.
1788 if (mem_cgroup_disabled())
1791 memcg
= page
->mem_cgroup
;
1792 if (unlikely(!memcg
))
1795 if (atomic_read(&memcg
->moving_account
) <= 0)
1798 spin_lock_irqsave(&memcg
->move_lock
, flags
);
1799 if (memcg
!= page
->mem_cgroup
) {
1800 spin_unlock_irqrestore(&memcg
->move_lock
, flags
);
1805 * When charge migration first begins, we can have locked and
1806 * unlocked page stat updates happening concurrently. Track
1807 * the task who has the lock for mem_cgroup_end_page_stat().
1809 memcg
->move_lock_task
= current
;
1810 memcg
->move_lock_flags
= flags
;
1814 EXPORT_SYMBOL(mem_cgroup_begin_page_stat
);
1817 * mem_cgroup_end_page_stat - finish a page state statistics transaction
1818 * @memcg: the memcg that was accounted against
1820 void mem_cgroup_end_page_stat(struct mem_cgroup
*memcg
)
1822 if (memcg
&& memcg
->move_lock_task
== current
) {
1823 unsigned long flags
= memcg
->move_lock_flags
;
1825 memcg
->move_lock_task
= NULL
;
1826 memcg
->move_lock_flags
= 0;
1828 spin_unlock_irqrestore(&memcg
->move_lock
, flags
);
1833 EXPORT_SYMBOL(mem_cgroup_end_page_stat
);
1836 * size of first charge trial. "32" comes from vmscan.c's magic value.
1837 * TODO: maybe necessary to use big numbers in big irons.
1839 #define CHARGE_BATCH 32U
1840 struct memcg_stock_pcp
{
1841 struct mem_cgroup
*cached
; /* this never be root cgroup */
1842 unsigned int nr_pages
;
1843 struct work_struct work
;
1844 unsigned long flags
;
1845 #define FLUSHING_CACHED_CHARGE 0
1847 static DEFINE_PER_CPU(struct memcg_stock_pcp
, memcg_stock
);
1848 static DEFINE_MUTEX(percpu_charge_mutex
);
1851 * consume_stock: Try to consume stocked charge on this cpu.
1852 * @memcg: memcg to consume from.
1853 * @nr_pages: how many pages to charge.
1855 * The charges will only happen if @memcg matches the current cpu's memcg
1856 * stock, and at least @nr_pages are available in that stock. Failure to
1857 * service an allocation will refill the stock.
1859 * returns true if successful, false otherwise.
1861 static bool consume_stock(struct mem_cgroup
*memcg
, unsigned int nr_pages
)
1863 struct memcg_stock_pcp
*stock
;
1866 if (nr_pages
> CHARGE_BATCH
)
1869 stock
= &get_cpu_var(memcg_stock
);
1870 if (memcg
== stock
->cached
&& stock
->nr_pages
>= nr_pages
) {
1871 stock
->nr_pages
-= nr_pages
;
1874 put_cpu_var(memcg_stock
);
1879 * Returns stocks cached in percpu and reset cached information.
1881 static void drain_stock(struct memcg_stock_pcp
*stock
)
1883 struct mem_cgroup
*old
= stock
->cached
;
1885 if (stock
->nr_pages
) {
1886 page_counter_uncharge(&old
->memory
, stock
->nr_pages
);
1887 if (do_swap_account
)
1888 page_counter_uncharge(&old
->memsw
, stock
->nr_pages
);
1889 css_put_many(&old
->css
, stock
->nr_pages
);
1890 stock
->nr_pages
= 0;
1892 stock
->cached
= NULL
;
1896 * This must be called under preempt disabled or must be called by
1897 * a thread which is pinned to local cpu.
1899 static void drain_local_stock(struct work_struct
*dummy
)
1901 struct memcg_stock_pcp
*stock
= this_cpu_ptr(&memcg_stock
);
1903 clear_bit(FLUSHING_CACHED_CHARGE
, &stock
->flags
);
1907 * Cache charges(val) to local per_cpu area.
1908 * This will be consumed by consume_stock() function, later.
1910 static void refill_stock(struct mem_cgroup
*memcg
, unsigned int nr_pages
)
1912 struct memcg_stock_pcp
*stock
= &get_cpu_var(memcg_stock
);
1914 if (stock
->cached
!= memcg
) { /* reset if necessary */
1916 stock
->cached
= memcg
;
1918 stock
->nr_pages
+= nr_pages
;
1919 put_cpu_var(memcg_stock
);
1923 * Drains all per-CPU charge caches for given root_memcg resp. subtree
1924 * of the hierarchy under it.
1926 static void drain_all_stock(struct mem_cgroup
*root_memcg
)
1930 /* If someone's already draining, avoid adding running more workers. */
1931 if (!mutex_trylock(&percpu_charge_mutex
))
1933 /* Notify other cpus that system-wide "drain" is running */
1936 for_each_online_cpu(cpu
) {
1937 struct memcg_stock_pcp
*stock
= &per_cpu(memcg_stock
, cpu
);
1938 struct mem_cgroup
*memcg
;
1940 memcg
= stock
->cached
;
1941 if (!memcg
|| !stock
->nr_pages
)
1943 if (!mem_cgroup_is_descendant(memcg
, root_memcg
))
1945 if (!test_and_set_bit(FLUSHING_CACHED_CHARGE
, &stock
->flags
)) {
1947 drain_local_stock(&stock
->work
);
1949 schedule_work_on(cpu
, &stock
->work
);
1954 mutex_unlock(&percpu_charge_mutex
);
1957 static int memcg_cpu_hotplug_callback(struct notifier_block
*nb
,
1958 unsigned long action
,
1961 int cpu
= (unsigned long)hcpu
;
1962 struct memcg_stock_pcp
*stock
;
1964 if (action
== CPU_ONLINE
)
1967 if (action
!= CPU_DEAD
&& action
!= CPU_DEAD_FROZEN
)
1970 stock
= &per_cpu(memcg_stock
, cpu
);
1975 static int try_charge(struct mem_cgroup
*memcg
, gfp_t gfp_mask
,
1976 unsigned int nr_pages
)
1978 unsigned int batch
= max(CHARGE_BATCH
, nr_pages
);
1979 int nr_retries
= MEM_CGROUP_RECLAIM_RETRIES
;
1980 struct mem_cgroup
*mem_over_limit
;
1981 struct page_counter
*counter
;
1982 unsigned long nr_reclaimed
;
1983 bool may_swap
= true;
1984 bool drained
= false;
1987 if (mem_cgroup_is_root(memcg
))
1990 if (consume_stock(memcg
, nr_pages
))
1993 if (!do_swap_account
||
1994 !page_counter_try_charge(&memcg
->memsw
, batch
, &counter
)) {
1995 if (!page_counter_try_charge(&memcg
->memory
, batch
, &counter
))
1997 if (do_swap_account
)
1998 page_counter_uncharge(&memcg
->memsw
, batch
);
1999 mem_over_limit
= mem_cgroup_from_counter(counter
, memory
);
2001 mem_over_limit
= mem_cgroup_from_counter(counter
, memsw
);
2005 if (batch
> nr_pages
) {
2011 * Unlike in global OOM situations, memcg is not in a physical
2012 * memory shortage. Allow dying and OOM-killed tasks to
2013 * bypass the last charges so that they can exit quickly and
2014 * free their memory.
2016 if (unlikely(test_thread_flag(TIF_MEMDIE
) ||
2017 fatal_signal_pending(current
) ||
2018 current
->flags
& PF_EXITING
))
2021 if (unlikely(task_in_memcg_oom(current
)))
2024 if (!(gfp_mask
& __GFP_WAIT
))
2027 mem_cgroup_events(mem_over_limit
, MEMCG_MAX
, 1);
2029 nr_reclaimed
= try_to_free_mem_cgroup_pages(mem_over_limit
, nr_pages
,
2030 gfp_mask
, may_swap
);
2032 if (mem_cgroup_margin(mem_over_limit
) >= nr_pages
)
2036 drain_all_stock(mem_over_limit
);
2041 if (gfp_mask
& __GFP_NORETRY
)
2044 * Even though the limit is exceeded at this point, reclaim
2045 * may have been able to free some pages. Retry the charge
2046 * before killing the task.
2048 * Only for regular pages, though: huge pages are rather
2049 * unlikely to succeed so close to the limit, and we fall back
2050 * to regular pages anyway in case of failure.
2052 if (nr_reclaimed
&& nr_pages
<= (1 << PAGE_ALLOC_COSTLY_ORDER
))
2055 * At task move, charge accounts can be doubly counted. So, it's
2056 * better to wait until the end of task_move if something is going on.
2058 if (mem_cgroup_wait_acct_move(mem_over_limit
))
2064 if (gfp_mask
& __GFP_NOFAIL
)
2067 if (fatal_signal_pending(current
))
2070 mem_cgroup_events(mem_over_limit
, MEMCG_OOM
, 1);
2072 mem_cgroup_oom(mem_over_limit
, gfp_mask
, get_order(nr_pages
));
2074 if (!(gfp_mask
& __GFP_NOFAIL
))
2080 css_get_many(&memcg
->css
, batch
);
2081 if (batch
> nr_pages
)
2082 refill_stock(memcg
, batch
- nr_pages
);
2083 if (!(gfp_mask
& __GFP_WAIT
))
2086 * If the hierarchy is above the normal consumption range,
2087 * make the charging task trim their excess contribution.
2090 if (page_counter_read(&memcg
->memory
) <= memcg
->high
)
2092 mem_cgroup_events(memcg
, MEMCG_HIGH
, 1);
2093 try_to_free_mem_cgroup_pages(memcg
, nr_pages
, gfp_mask
, true);
2094 } while ((memcg
= parent_mem_cgroup(memcg
)));
2099 static void cancel_charge(struct mem_cgroup
*memcg
, unsigned int nr_pages
)
2101 if (mem_cgroup_is_root(memcg
))
2104 page_counter_uncharge(&memcg
->memory
, nr_pages
);
2105 if (do_swap_account
)
2106 page_counter_uncharge(&memcg
->memsw
, nr_pages
);
2108 css_put_many(&memcg
->css
, nr_pages
);
2111 static void lock_page_lru(struct page
*page
, int *isolated
)
2113 struct zone
*zone
= page_zone(page
);
2115 spin_lock_irq(&zone
->lru_lock
);
2116 if (PageLRU(page
)) {
2117 struct lruvec
*lruvec
;
2119 lruvec
= mem_cgroup_page_lruvec(page
, zone
);
2121 del_page_from_lru_list(page
, lruvec
, page_lru(page
));
2127 static void unlock_page_lru(struct page
*page
, int isolated
)
2129 struct zone
*zone
= page_zone(page
);
2132 struct lruvec
*lruvec
;
2134 lruvec
= mem_cgroup_page_lruvec(page
, zone
);
2135 VM_BUG_ON_PAGE(PageLRU(page
), page
);
2137 add_page_to_lru_list(page
, lruvec
, page_lru(page
));
2139 spin_unlock_irq(&zone
->lru_lock
);
2142 static void commit_charge(struct page
*page
, struct mem_cgroup
*memcg
,
2147 VM_BUG_ON_PAGE(page
->mem_cgroup
, page
);
2150 * In some cases, SwapCache and FUSE(splice_buf->radixtree), the page
2151 * may already be on some other mem_cgroup's LRU. Take care of it.
2154 lock_page_lru(page
, &isolated
);
2157 * Nobody should be changing or seriously looking at
2158 * page->mem_cgroup at this point:
2160 * - the page is uncharged
2162 * - the page is off-LRU
2164 * - an anonymous fault has exclusive page access, except for
2165 * a locked page table
2167 * - a page cache insertion, a swapin fault, or a migration
2168 * have the page locked
2170 page
->mem_cgroup
= memcg
;
2173 unlock_page_lru(page
, isolated
);
2176 #ifdef CONFIG_MEMCG_KMEM
2177 int memcg_charge_kmem(struct mem_cgroup
*memcg
, gfp_t gfp
,
2178 unsigned long nr_pages
)
2180 struct page_counter
*counter
;
2183 ret
= page_counter_try_charge(&memcg
->kmem
, nr_pages
, &counter
);
2187 ret
= try_charge(memcg
, gfp
, nr_pages
);
2188 if (ret
== -EINTR
) {
2190 * try_charge() chose to bypass to root due to OOM kill or
2191 * fatal signal. Since our only options are to either fail
2192 * the allocation or charge it to this cgroup, do it as a
2193 * temporary condition. But we can't fail. From a kmem/slab
2194 * perspective, the cache has already been selected, by
2195 * mem_cgroup_kmem_get_cache(), so it is too late to change
2198 * This condition will only trigger if the task entered
2199 * memcg_charge_kmem in a sane state, but was OOM-killed
2200 * during try_charge() above. Tasks that were already dying
2201 * when the allocation triggers should have been already
2202 * directed to the root cgroup in memcontrol.h
2204 page_counter_charge(&memcg
->memory
, nr_pages
);
2205 if (do_swap_account
)
2206 page_counter_charge(&memcg
->memsw
, nr_pages
);
2207 css_get_many(&memcg
->css
, nr_pages
);
2210 page_counter_uncharge(&memcg
->kmem
, nr_pages
);
2215 void memcg_uncharge_kmem(struct mem_cgroup
*memcg
, unsigned long nr_pages
)
2217 page_counter_uncharge(&memcg
->memory
, nr_pages
);
2218 if (do_swap_account
)
2219 page_counter_uncharge(&memcg
->memsw
, nr_pages
);
2221 page_counter_uncharge(&memcg
->kmem
, nr_pages
);
2223 css_put_many(&memcg
->css
, nr_pages
);
2226 static int memcg_alloc_cache_id(void)
2231 id
= ida_simple_get(&memcg_cache_ida
,
2232 0, MEMCG_CACHES_MAX_SIZE
, GFP_KERNEL
);
2236 if (id
< memcg_nr_cache_ids
)
2240 * There's no space for the new id in memcg_caches arrays,
2241 * so we have to grow them.
2243 down_write(&memcg_cache_ids_sem
);
2245 size
= 2 * (id
+ 1);
2246 if (size
< MEMCG_CACHES_MIN_SIZE
)
2247 size
= MEMCG_CACHES_MIN_SIZE
;
2248 else if (size
> MEMCG_CACHES_MAX_SIZE
)
2249 size
= MEMCG_CACHES_MAX_SIZE
;
2251 err
= memcg_update_all_caches(size
);
2253 err
= memcg_update_all_list_lrus(size
);
2255 memcg_nr_cache_ids
= size
;
2257 up_write(&memcg_cache_ids_sem
);
2260 ida_simple_remove(&memcg_cache_ida
, id
);
2266 static void memcg_free_cache_id(int id
)
2268 ida_simple_remove(&memcg_cache_ida
, id
);
2271 struct memcg_kmem_cache_create_work
{
2272 struct mem_cgroup
*memcg
;
2273 struct kmem_cache
*cachep
;
2274 struct work_struct work
;
2277 static void memcg_kmem_cache_create_func(struct work_struct
*w
)
2279 struct memcg_kmem_cache_create_work
*cw
=
2280 container_of(w
, struct memcg_kmem_cache_create_work
, work
);
2281 struct mem_cgroup
*memcg
= cw
->memcg
;
2282 struct kmem_cache
*cachep
= cw
->cachep
;
2284 memcg_create_kmem_cache(memcg
, cachep
);
2286 css_put(&memcg
->css
);
2291 * Enqueue the creation of a per-memcg kmem_cache.
2293 static void __memcg_schedule_kmem_cache_create(struct mem_cgroup
*memcg
,
2294 struct kmem_cache
*cachep
)
2296 struct memcg_kmem_cache_create_work
*cw
;
2298 cw
= kmalloc(sizeof(*cw
), GFP_NOWAIT
);
2302 css_get(&memcg
->css
);
2305 cw
->cachep
= cachep
;
2306 INIT_WORK(&cw
->work
, memcg_kmem_cache_create_func
);
2308 schedule_work(&cw
->work
);
2311 static void memcg_schedule_kmem_cache_create(struct mem_cgroup
*memcg
,
2312 struct kmem_cache
*cachep
)
2315 * We need to stop accounting when we kmalloc, because if the
2316 * corresponding kmalloc cache is not yet created, the first allocation
2317 * in __memcg_schedule_kmem_cache_create will recurse.
2319 * However, it is better to enclose the whole function. Depending on
2320 * the debugging options enabled, INIT_WORK(), for instance, can
2321 * trigger an allocation. This too, will make us recurse. Because at
2322 * this point we can't allow ourselves back into memcg_kmem_get_cache,
2323 * the safest choice is to do it like this, wrapping the whole function.
2325 current
->memcg_kmem_skip_account
= 1;
2326 __memcg_schedule_kmem_cache_create(memcg
, cachep
);
2327 current
->memcg_kmem_skip_account
= 0;
2331 * Return the kmem_cache we're supposed to use for a slab allocation.
2332 * We try to use the current memcg's version of the cache.
2334 * If the cache does not exist yet, if we are the first user of it,
2335 * we either create it immediately, if possible, or create it asynchronously
2337 * In the latter case, we will let the current allocation go through with
2338 * the original cache.
2340 * Can't be called in interrupt context or from kernel threads.
2341 * This function needs to be called with rcu_read_lock() held.
2343 struct kmem_cache
*__memcg_kmem_get_cache(struct kmem_cache
*cachep
)
2345 struct mem_cgroup
*memcg
;
2346 struct kmem_cache
*memcg_cachep
;
2349 VM_BUG_ON(!is_root_cache(cachep
));
2351 if (current
->memcg_kmem_skip_account
)
2354 memcg
= get_mem_cgroup_from_mm(current
->mm
);
2355 kmemcg_id
= READ_ONCE(memcg
->kmemcg_id
);
2359 memcg_cachep
= cache_from_memcg_idx(cachep
, kmemcg_id
);
2360 if (likely(memcg_cachep
))
2361 return memcg_cachep
;
2364 * If we are in a safe context (can wait, and not in interrupt
2365 * context), we could be be predictable and return right away.
2366 * This would guarantee that the allocation being performed
2367 * already belongs in the new cache.
2369 * However, there are some clashes that can arrive from locking.
2370 * For instance, because we acquire the slab_mutex while doing
2371 * memcg_create_kmem_cache, this means no further allocation
2372 * could happen with the slab_mutex held. So it's better to
2375 memcg_schedule_kmem_cache_create(memcg
, cachep
);
2377 css_put(&memcg
->css
);
2381 void __memcg_kmem_put_cache(struct kmem_cache
*cachep
)
2383 if (!is_root_cache(cachep
))
2384 css_put(&cachep
->memcg_params
.memcg
->css
);
2388 * We need to verify if the allocation against current->mm->owner's memcg is
2389 * possible for the given order. But the page is not allocated yet, so we'll
2390 * need a further commit step to do the final arrangements.
2392 * It is possible for the task to switch cgroups in this mean time, so at
2393 * commit time, we can't rely on task conversion any longer. We'll then use
2394 * the handle argument to return to the caller which cgroup we should commit
2395 * against. We could also return the memcg directly and avoid the pointer
2396 * passing, but a boolean return value gives better semantics considering
2397 * the compiled-out case as well.
2399 * Returning true means the allocation is possible.
2402 __memcg_kmem_newpage_charge(gfp_t gfp
, struct mem_cgroup
**_memcg
, int order
)
2404 struct mem_cgroup
*memcg
;
2409 memcg
= get_mem_cgroup_from_mm(current
->mm
);
2411 if (!memcg_kmem_is_active(memcg
)) {
2412 css_put(&memcg
->css
);
2416 ret
= memcg_charge_kmem(memcg
, gfp
, 1 << order
);
2420 css_put(&memcg
->css
);
2424 void __memcg_kmem_commit_charge(struct page
*page
, struct mem_cgroup
*memcg
,
2427 VM_BUG_ON(mem_cgroup_is_root(memcg
));
2429 /* The page allocation failed. Revert */
2431 memcg_uncharge_kmem(memcg
, 1 << order
);
2434 page
->mem_cgroup
= memcg
;
2437 void __memcg_kmem_uncharge_pages(struct page
*page
, int order
)
2439 struct mem_cgroup
*memcg
= page
->mem_cgroup
;
2444 VM_BUG_ON_PAGE(mem_cgroup_is_root(memcg
), page
);
2446 memcg_uncharge_kmem(memcg
, 1 << order
);
2447 page
->mem_cgroup
= NULL
;
2450 struct mem_cgroup
*__mem_cgroup_from_kmem(void *ptr
)
2452 struct mem_cgroup
*memcg
= NULL
;
2453 struct kmem_cache
*cachep
;
2456 page
= virt_to_head_page(ptr
);
2457 if (PageSlab(page
)) {
2458 cachep
= page
->slab_cache
;
2459 if (!is_root_cache(cachep
))
2460 memcg
= cachep
->memcg_params
.memcg
;
2462 /* page allocated by alloc_kmem_pages */
2463 memcg
= page
->mem_cgroup
;
2467 #endif /* CONFIG_MEMCG_KMEM */
2469 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
2472 * Because tail pages are not marked as "used", set it. We're under
2473 * zone->lru_lock, 'splitting on pmd' and compound_lock.
2474 * charge/uncharge will be never happen and move_account() is done under
2475 * compound_lock(), so we don't have to take care of races.
2477 void mem_cgroup_split_huge_fixup(struct page
*head
)
2481 if (mem_cgroup_disabled())
2484 for (i
= 1; i
< HPAGE_PMD_NR
; i
++)
2485 head
[i
].mem_cgroup
= head
->mem_cgroup
;
2487 __this_cpu_sub(head
->mem_cgroup
->stat
->count
[MEM_CGROUP_STAT_RSS_HUGE
],
2490 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
2492 #ifdef CONFIG_MEMCG_SWAP
2493 static void mem_cgroup_swap_statistics(struct mem_cgroup
*memcg
,
2496 int val
= (charge
) ? 1 : -1;
2497 this_cpu_add(memcg
->stat
->count
[MEM_CGROUP_STAT_SWAP
], val
);
2501 * mem_cgroup_move_swap_account - move swap charge and swap_cgroup's record.
2502 * @entry: swap entry to be moved
2503 * @from: mem_cgroup which the entry is moved from
2504 * @to: mem_cgroup which the entry is moved to
2506 * It succeeds only when the swap_cgroup's record for this entry is the same
2507 * as the mem_cgroup's id of @from.
2509 * Returns 0 on success, -EINVAL on failure.
2511 * The caller must have charged to @to, IOW, called page_counter_charge() about
2512 * both res and memsw, and called css_get().
2514 static int mem_cgroup_move_swap_account(swp_entry_t entry
,
2515 struct mem_cgroup
*from
, struct mem_cgroup
*to
)
2517 unsigned short old_id
, new_id
;
2519 old_id
= mem_cgroup_id(from
);
2520 new_id
= mem_cgroup_id(to
);
2522 if (swap_cgroup_cmpxchg(entry
, old_id
, new_id
) == old_id
) {
2523 mem_cgroup_swap_statistics(from
, false);
2524 mem_cgroup_swap_statistics(to
, true);
2530 static inline int mem_cgroup_move_swap_account(swp_entry_t entry
,
2531 struct mem_cgroup
*from
, struct mem_cgroup
*to
)
2537 static DEFINE_MUTEX(memcg_limit_mutex
);
2539 static int mem_cgroup_resize_limit(struct mem_cgroup
*memcg
,
2540 unsigned long limit
)
2542 unsigned long curusage
;
2543 unsigned long oldusage
;
2544 bool enlarge
= false;
2549 * For keeping hierarchical_reclaim simple, how long we should retry
2550 * is depends on callers. We set our retry-count to be function
2551 * of # of children which we should visit in this loop.
2553 retry_count
= MEM_CGROUP_RECLAIM_RETRIES
*
2554 mem_cgroup_count_children(memcg
);
2556 oldusage
= page_counter_read(&memcg
->memory
);
2559 if (signal_pending(current
)) {
2564 mutex_lock(&memcg_limit_mutex
);
2565 if (limit
> memcg
->memsw
.limit
) {
2566 mutex_unlock(&memcg_limit_mutex
);
2570 if (limit
> memcg
->memory
.limit
)
2572 ret
= page_counter_limit(&memcg
->memory
, limit
);
2573 mutex_unlock(&memcg_limit_mutex
);
2578 try_to_free_mem_cgroup_pages(memcg
, 1, GFP_KERNEL
, true);
2580 curusage
= page_counter_read(&memcg
->memory
);
2581 /* Usage is reduced ? */
2582 if (curusage
>= oldusage
)
2585 oldusage
= curusage
;
2586 } while (retry_count
);
2588 if (!ret
&& enlarge
)
2589 memcg_oom_recover(memcg
);
2594 static int mem_cgroup_resize_memsw_limit(struct mem_cgroup
*memcg
,
2595 unsigned long limit
)
2597 unsigned long curusage
;
2598 unsigned long oldusage
;
2599 bool enlarge
= false;
2603 /* see mem_cgroup_resize_res_limit */
2604 retry_count
= MEM_CGROUP_RECLAIM_RETRIES
*
2605 mem_cgroup_count_children(memcg
);
2607 oldusage
= page_counter_read(&memcg
->memsw
);
2610 if (signal_pending(current
)) {
2615 mutex_lock(&memcg_limit_mutex
);
2616 if (limit
< memcg
->memory
.limit
) {
2617 mutex_unlock(&memcg_limit_mutex
);
2621 if (limit
> memcg
->memsw
.limit
)
2623 ret
= page_counter_limit(&memcg
->memsw
, limit
);
2624 mutex_unlock(&memcg_limit_mutex
);
2629 try_to_free_mem_cgroup_pages(memcg
, 1, GFP_KERNEL
, false);
2631 curusage
= page_counter_read(&memcg
->memsw
);
2632 /* Usage is reduced ? */
2633 if (curusage
>= oldusage
)
2636 oldusage
= curusage
;
2637 } while (retry_count
);
2639 if (!ret
&& enlarge
)
2640 memcg_oom_recover(memcg
);
2645 unsigned long mem_cgroup_soft_limit_reclaim(struct zone
*zone
, int order
,
2647 unsigned long *total_scanned
)
2649 unsigned long nr_reclaimed
= 0;
2650 struct mem_cgroup_per_zone
*mz
, *next_mz
= NULL
;
2651 unsigned long reclaimed
;
2653 struct mem_cgroup_tree_per_zone
*mctz
;
2654 unsigned long excess
;
2655 unsigned long nr_scanned
;
2660 mctz
= soft_limit_tree_node_zone(zone_to_nid(zone
), zone_idx(zone
));
2662 * This loop can run a while, specially if mem_cgroup's continuously
2663 * keep exceeding their soft limit and putting the system under
2670 mz
= mem_cgroup_largest_soft_limit_node(mctz
);
2675 reclaimed
= mem_cgroup_soft_reclaim(mz
->memcg
, zone
,
2676 gfp_mask
, &nr_scanned
);
2677 nr_reclaimed
+= reclaimed
;
2678 *total_scanned
+= nr_scanned
;
2679 spin_lock_irq(&mctz
->lock
);
2680 __mem_cgroup_remove_exceeded(mz
, mctz
);
2683 * If we failed to reclaim anything from this memory cgroup
2684 * it is time to move on to the next cgroup
2688 next_mz
= __mem_cgroup_largest_soft_limit_node(mctz
);
2690 excess
= soft_limit_excess(mz
->memcg
);
2692 * One school of thought says that we should not add
2693 * back the node to the tree if reclaim returns 0.
2694 * But our reclaim could return 0, simply because due
2695 * to priority we are exposing a smaller subset of
2696 * memory to reclaim from. Consider this as a longer
2699 /* If excess == 0, no tree ops */
2700 __mem_cgroup_insert_exceeded(mz
, mctz
, excess
);
2701 spin_unlock_irq(&mctz
->lock
);
2702 css_put(&mz
->memcg
->css
);
2705 * Could not reclaim anything and there are no more
2706 * mem cgroups to try or we seem to be looping without
2707 * reclaiming anything.
2709 if (!nr_reclaimed
&&
2711 loop
> MEM_CGROUP_MAX_SOFT_LIMIT_RECLAIM_LOOPS
))
2713 } while (!nr_reclaimed
);
2715 css_put(&next_mz
->memcg
->css
);
2716 return nr_reclaimed
;
2720 * Test whether @memcg has children, dead or alive. Note that this
2721 * function doesn't care whether @memcg has use_hierarchy enabled and
2722 * returns %true if there are child csses according to the cgroup
2723 * hierarchy. Testing use_hierarchy is the caller's responsiblity.
2725 static inline bool memcg_has_children(struct mem_cgroup
*memcg
)
2730 * The lock does not prevent addition or deletion of children, but
2731 * it prevents a new child from being initialized based on this
2732 * parent in css_online(), so it's enough to decide whether
2733 * hierarchically inherited attributes can still be changed or not.
2735 lockdep_assert_held(&memcg_create_mutex
);
2738 ret
= css_next_child(NULL
, &memcg
->css
);
2744 * Reclaims as many pages from the given memcg as possible and moves
2745 * the rest to the parent.
2747 * Caller is responsible for holding css reference for memcg.
2749 static int mem_cgroup_force_empty(struct mem_cgroup
*memcg
)
2751 int nr_retries
= MEM_CGROUP_RECLAIM_RETRIES
;
2753 /* we call try-to-free pages for make this cgroup empty */
2754 lru_add_drain_all();
2755 /* try to free all pages in this cgroup */
2756 while (nr_retries
&& page_counter_read(&memcg
->memory
)) {
2759 if (signal_pending(current
))
2762 progress
= try_to_free_mem_cgroup_pages(memcg
, 1,
2766 /* maybe some writeback is necessary */
2767 congestion_wait(BLK_RW_ASYNC
, HZ
/10);
2775 static ssize_t
mem_cgroup_force_empty_write(struct kernfs_open_file
*of
,
2776 char *buf
, size_t nbytes
,
2779 struct mem_cgroup
*memcg
= mem_cgroup_from_css(of_css(of
));
2781 if (mem_cgroup_is_root(memcg
))
2783 return mem_cgroup_force_empty(memcg
) ?: nbytes
;
2786 static u64
mem_cgroup_hierarchy_read(struct cgroup_subsys_state
*css
,
2789 return mem_cgroup_from_css(css
)->use_hierarchy
;
2792 static int mem_cgroup_hierarchy_write(struct cgroup_subsys_state
*css
,
2793 struct cftype
*cft
, u64 val
)
2796 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
2797 struct mem_cgroup
*parent_memcg
= mem_cgroup_from_css(memcg
->css
.parent
);
2799 mutex_lock(&memcg_create_mutex
);
2801 if (memcg
->use_hierarchy
== val
)
2805 * If parent's use_hierarchy is set, we can't make any modifications
2806 * in the child subtrees. If it is unset, then the change can
2807 * occur, provided the current cgroup has no children.
2809 * For the root cgroup, parent_mem is NULL, we allow value to be
2810 * set if there are no children.
2812 if ((!parent_memcg
|| !parent_memcg
->use_hierarchy
) &&
2813 (val
== 1 || val
== 0)) {
2814 if (!memcg_has_children(memcg
))
2815 memcg
->use_hierarchy
= val
;
2822 mutex_unlock(&memcg_create_mutex
);
2827 static unsigned long tree_stat(struct mem_cgroup
*memcg
,
2828 enum mem_cgroup_stat_index idx
)
2830 struct mem_cgroup
*iter
;
2831 unsigned long val
= 0;
2833 for_each_mem_cgroup_tree(iter
, memcg
)
2834 val
+= mem_cgroup_read_stat(iter
, idx
);
2839 static inline u64
mem_cgroup_usage(struct mem_cgroup
*memcg
, bool swap
)
2843 if (mem_cgroup_is_root(memcg
)) {
2844 val
= tree_stat(memcg
, MEM_CGROUP_STAT_CACHE
);
2845 val
+= tree_stat(memcg
, MEM_CGROUP_STAT_RSS
);
2847 val
+= tree_stat(memcg
, MEM_CGROUP_STAT_SWAP
);
2850 val
= page_counter_read(&memcg
->memory
);
2852 val
= page_counter_read(&memcg
->memsw
);
2854 return val
<< PAGE_SHIFT
;
2865 static u64
mem_cgroup_read_u64(struct cgroup_subsys_state
*css
,
2868 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
2869 struct page_counter
*counter
;
2871 switch (MEMFILE_TYPE(cft
->private)) {
2873 counter
= &memcg
->memory
;
2876 counter
= &memcg
->memsw
;
2879 counter
= &memcg
->kmem
;
2885 switch (MEMFILE_ATTR(cft
->private)) {
2887 if (counter
== &memcg
->memory
)
2888 return mem_cgroup_usage(memcg
, false);
2889 if (counter
== &memcg
->memsw
)
2890 return mem_cgroup_usage(memcg
, true);
2891 return (u64
)page_counter_read(counter
) * PAGE_SIZE
;
2893 return (u64
)counter
->limit
* PAGE_SIZE
;
2895 return (u64
)counter
->watermark
* PAGE_SIZE
;
2897 return counter
->failcnt
;
2898 case RES_SOFT_LIMIT
:
2899 return (u64
)memcg
->soft_limit
* PAGE_SIZE
;
2905 #ifdef CONFIG_MEMCG_KMEM
2906 static int memcg_activate_kmem(struct mem_cgroup
*memcg
,
2907 unsigned long nr_pages
)
2912 BUG_ON(memcg
->kmemcg_id
>= 0);
2913 BUG_ON(memcg
->kmem_acct_activated
);
2914 BUG_ON(memcg
->kmem_acct_active
);
2917 * For simplicity, we won't allow this to be disabled. It also can't
2918 * be changed if the cgroup has children already, or if tasks had
2921 * If tasks join before we set the limit, a person looking at
2922 * kmem.usage_in_bytes will have no way to determine when it took
2923 * place, which makes the value quite meaningless.
2925 * After it first became limited, changes in the value of the limit are
2926 * of course permitted.
2928 mutex_lock(&memcg_create_mutex
);
2929 if (cgroup_has_tasks(memcg
->css
.cgroup
) ||
2930 (memcg
->use_hierarchy
&& memcg_has_children(memcg
)))
2932 mutex_unlock(&memcg_create_mutex
);
2936 memcg_id
= memcg_alloc_cache_id();
2943 * We couldn't have accounted to this cgroup, because it hasn't got
2944 * activated yet, so this should succeed.
2946 err
= page_counter_limit(&memcg
->kmem
, nr_pages
);
2949 static_key_slow_inc(&memcg_kmem_enabled_key
);
2951 * A memory cgroup is considered kmem-active as soon as it gets
2952 * kmemcg_id. Setting the id after enabling static branching will
2953 * guarantee no one starts accounting before all call sites are
2956 memcg
->kmemcg_id
= memcg_id
;
2957 memcg
->kmem_acct_activated
= true;
2958 memcg
->kmem_acct_active
= true;
2963 static int memcg_update_kmem_limit(struct mem_cgroup
*memcg
,
2964 unsigned long limit
)
2968 mutex_lock(&memcg_limit_mutex
);
2969 if (!memcg_kmem_is_active(memcg
))
2970 ret
= memcg_activate_kmem(memcg
, limit
);
2972 ret
= page_counter_limit(&memcg
->kmem
, limit
);
2973 mutex_unlock(&memcg_limit_mutex
);
2977 static int memcg_propagate_kmem(struct mem_cgroup
*memcg
)
2980 struct mem_cgroup
*parent
= parent_mem_cgroup(memcg
);
2985 mutex_lock(&memcg_limit_mutex
);
2987 * If the parent cgroup is not kmem-active now, it cannot be activated
2988 * after this point, because it has at least one child already.
2990 if (memcg_kmem_is_active(parent
))
2991 ret
= memcg_activate_kmem(memcg
, PAGE_COUNTER_MAX
);
2992 mutex_unlock(&memcg_limit_mutex
);
2996 static int memcg_update_kmem_limit(struct mem_cgroup
*memcg
,
2997 unsigned long limit
)
3001 #endif /* CONFIG_MEMCG_KMEM */
3004 * The user of this function is...
3007 static ssize_t
mem_cgroup_write(struct kernfs_open_file
*of
,
3008 char *buf
, size_t nbytes
, loff_t off
)
3010 struct mem_cgroup
*memcg
= mem_cgroup_from_css(of_css(of
));
3011 unsigned long nr_pages
;
3014 buf
= strstrip(buf
);
3015 ret
= page_counter_memparse(buf
, "-1", &nr_pages
);
3019 switch (MEMFILE_ATTR(of_cft(of
)->private)) {
3021 if (mem_cgroup_is_root(memcg
)) { /* Can't set limit on root */
3025 switch (MEMFILE_TYPE(of_cft(of
)->private)) {
3027 ret
= mem_cgroup_resize_limit(memcg
, nr_pages
);
3030 ret
= mem_cgroup_resize_memsw_limit(memcg
, nr_pages
);
3033 ret
= memcg_update_kmem_limit(memcg
, nr_pages
);
3037 case RES_SOFT_LIMIT
:
3038 memcg
->soft_limit
= nr_pages
;
3042 return ret
?: nbytes
;
3045 static ssize_t
mem_cgroup_reset(struct kernfs_open_file
*of
, char *buf
,
3046 size_t nbytes
, loff_t off
)
3048 struct mem_cgroup
*memcg
= mem_cgroup_from_css(of_css(of
));
3049 struct page_counter
*counter
;
3051 switch (MEMFILE_TYPE(of_cft(of
)->private)) {
3053 counter
= &memcg
->memory
;
3056 counter
= &memcg
->memsw
;
3059 counter
= &memcg
->kmem
;
3065 switch (MEMFILE_ATTR(of_cft(of
)->private)) {
3067 page_counter_reset_watermark(counter
);
3070 counter
->failcnt
= 0;
3079 static u64
mem_cgroup_move_charge_read(struct cgroup_subsys_state
*css
,
3082 return mem_cgroup_from_css(css
)->move_charge_at_immigrate
;
3086 static int mem_cgroup_move_charge_write(struct cgroup_subsys_state
*css
,
3087 struct cftype
*cft
, u64 val
)
3089 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
3091 if (val
& ~MOVE_MASK
)
3095 * No kind of locking is needed in here, because ->can_attach() will
3096 * check this value once in the beginning of the process, and then carry
3097 * on with stale data. This means that changes to this value will only
3098 * affect task migrations starting after the change.
3100 memcg
->move_charge_at_immigrate
= val
;
3104 static int mem_cgroup_move_charge_write(struct cgroup_subsys_state
*css
,
3105 struct cftype
*cft
, u64 val
)
3112 static int memcg_numa_stat_show(struct seq_file
*m
, void *v
)
3116 unsigned int lru_mask
;
3119 static const struct numa_stat stats
[] = {
3120 { "total", LRU_ALL
},
3121 { "file", LRU_ALL_FILE
},
3122 { "anon", LRU_ALL_ANON
},
3123 { "unevictable", BIT(LRU_UNEVICTABLE
) },
3125 const struct numa_stat
*stat
;
3128 struct mem_cgroup
*memcg
= mem_cgroup_from_css(seq_css(m
));
3130 for (stat
= stats
; stat
< stats
+ ARRAY_SIZE(stats
); stat
++) {
3131 nr
= mem_cgroup_nr_lru_pages(memcg
, stat
->lru_mask
);
3132 seq_printf(m
, "%s=%lu", stat
->name
, nr
);
3133 for_each_node_state(nid
, N_MEMORY
) {
3134 nr
= mem_cgroup_node_nr_lru_pages(memcg
, nid
,
3136 seq_printf(m
, " N%d=%lu", nid
, nr
);
3141 for (stat
= stats
; stat
< stats
+ ARRAY_SIZE(stats
); stat
++) {
3142 struct mem_cgroup
*iter
;
3145 for_each_mem_cgroup_tree(iter
, memcg
)
3146 nr
+= mem_cgroup_nr_lru_pages(iter
, stat
->lru_mask
);
3147 seq_printf(m
, "hierarchical_%s=%lu", stat
->name
, nr
);
3148 for_each_node_state(nid
, N_MEMORY
) {
3150 for_each_mem_cgroup_tree(iter
, memcg
)
3151 nr
+= mem_cgroup_node_nr_lru_pages(
3152 iter
, nid
, stat
->lru_mask
);
3153 seq_printf(m
, " N%d=%lu", nid
, nr
);
3160 #endif /* CONFIG_NUMA */
3162 static int memcg_stat_show(struct seq_file
*m
, void *v
)
3164 struct mem_cgroup
*memcg
= mem_cgroup_from_css(seq_css(m
));
3165 unsigned long memory
, memsw
;
3166 struct mem_cgroup
*mi
;
3169 BUILD_BUG_ON(ARRAY_SIZE(mem_cgroup_stat_names
) !=
3170 MEM_CGROUP_STAT_NSTATS
);
3171 BUILD_BUG_ON(ARRAY_SIZE(mem_cgroup_events_names
) !=
3172 MEM_CGROUP_EVENTS_NSTATS
);
3173 BUILD_BUG_ON(ARRAY_SIZE(mem_cgroup_lru_names
) != NR_LRU_LISTS
);
3175 for (i
= 0; i
< MEM_CGROUP_STAT_NSTATS
; i
++) {
3176 if (i
== MEM_CGROUP_STAT_SWAP
&& !do_swap_account
)
3178 seq_printf(m
, "%s %lu\n", mem_cgroup_stat_names
[i
],
3179 mem_cgroup_read_stat(memcg
, i
) * PAGE_SIZE
);
3182 for (i
= 0; i
< MEM_CGROUP_EVENTS_NSTATS
; i
++)
3183 seq_printf(m
, "%s %lu\n", mem_cgroup_events_names
[i
],
3184 mem_cgroup_read_events(memcg
, i
));
3186 for (i
= 0; i
< NR_LRU_LISTS
; i
++)
3187 seq_printf(m
, "%s %lu\n", mem_cgroup_lru_names
[i
],
3188 mem_cgroup_nr_lru_pages(memcg
, BIT(i
)) * PAGE_SIZE
);
3190 /* Hierarchical information */
3191 memory
= memsw
= PAGE_COUNTER_MAX
;
3192 for (mi
= memcg
; mi
; mi
= parent_mem_cgroup(mi
)) {
3193 memory
= min(memory
, mi
->memory
.limit
);
3194 memsw
= min(memsw
, mi
->memsw
.limit
);
3196 seq_printf(m
, "hierarchical_memory_limit %llu\n",
3197 (u64
)memory
* PAGE_SIZE
);
3198 if (do_swap_account
)
3199 seq_printf(m
, "hierarchical_memsw_limit %llu\n",
3200 (u64
)memsw
* PAGE_SIZE
);
3202 for (i
= 0; i
< MEM_CGROUP_STAT_NSTATS
; i
++) {
3203 unsigned long long val
= 0;
3205 if (i
== MEM_CGROUP_STAT_SWAP
&& !do_swap_account
)
3207 for_each_mem_cgroup_tree(mi
, memcg
)
3208 val
+= mem_cgroup_read_stat(mi
, i
) * PAGE_SIZE
;
3209 seq_printf(m
, "total_%s %llu\n", mem_cgroup_stat_names
[i
], val
);
3212 for (i
= 0; i
< MEM_CGROUP_EVENTS_NSTATS
; i
++) {
3213 unsigned long long val
= 0;
3215 for_each_mem_cgroup_tree(mi
, memcg
)
3216 val
+= mem_cgroup_read_events(mi
, i
);
3217 seq_printf(m
, "total_%s %llu\n",
3218 mem_cgroup_events_names
[i
], val
);
3221 for (i
= 0; i
< NR_LRU_LISTS
; i
++) {
3222 unsigned long long val
= 0;
3224 for_each_mem_cgroup_tree(mi
, memcg
)
3225 val
+= mem_cgroup_nr_lru_pages(mi
, BIT(i
)) * PAGE_SIZE
;
3226 seq_printf(m
, "total_%s %llu\n", mem_cgroup_lru_names
[i
], val
);
3229 #ifdef CONFIG_DEBUG_VM
3232 struct mem_cgroup_per_zone
*mz
;
3233 struct zone_reclaim_stat
*rstat
;
3234 unsigned long recent_rotated
[2] = {0, 0};
3235 unsigned long recent_scanned
[2] = {0, 0};
3237 for_each_online_node(nid
)
3238 for (zid
= 0; zid
< MAX_NR_ZONES
; zid
++) {
3239 mz
= &memcg
->nodeinfo
[nid
]->zoneinfo
[zid
];
3240 rstat
= &mz
->lruvec
.reclaim_stat
;
3242 recent_rotated
[0] += rstat
->recent_rotated
[0];
3243 recent_rotated
[1] += rstat
->recent_rotated
[1];
3244 recent_scanned
[0] += rstat
->recent_scanned
[0];
3245 recent_scanned
[1] += rstat
->recent_scanned
[1];
3247 seq_printf(m
, "recent_rotated_anon %lu\n", recent_rotated
[0]);
3248 seq_printf(m
, "recent_rotated_file %lu\n", recent_rotated
[1]);
3249 seq_printf(m
, "recent_scanned_anon %lu\n", recent_scanned
[0]);
3250 seq_printf(m
, "recent_scanned_file %lu\n", recent_scanned
[1]);
3257 static u64
mem_cgroup_swappiness_read(struct cgroup_subsys_state
*css
,
3260 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
3262 return mem_cgroup_swappiness(memcg
);
3265 static int mem_cgroup_swappiness_write(struct cgroup_subsys_state
*css
,
3266 struct cftype
*cft
, u64 val
)
3268 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
3274 memcg
->swappiness
= val
;
3276 vm_swappiness
= val
;
3281 static void __mem_cgroup_threshold(struct mem_cgroup
*memcg
, bool swap
)
3283 struct mem_cgroup_threshold_ary
*t
;
3284 unsigned long usage
;
3289 t
= rcu_dereference(memcg
->thresholds
.primary
);
3291 t
= rcu_dereference(memcg
->memsw_thresholds
.primary
);
3296 usage
= mem_cgroup_usage(memcg
, swap
);
3299 * current_threshold points to threshold just below or equal to usage.
3300 * If it's not true, a threshold was crossed after last
3301 * call of __mem_cgroup_threshold().
3303 i
= t
->current_threshold
;
3306 * Iterate backward over array of thresholds starting from
3307 * current_threshold and check if a threshold is crossed.
3308 * If none of thresholds below usage is crossed, we read
3309 * only one element of the array here.
3311 for (; i
>= 0 && unlikely(t
->entries
[i
].threshold
> usage
); i
--)
3312 eventfd_signal(t
->entries
[i
].eventfd
, 1);
3314 /* i = current_threshold + 1 */
3318 * Iterate forward over array of thresholds starting from
3319 * current_threshold+1 and check if a threshold is crossed.
3320 * If none of thresholds above usage is crossed, we read
3321 * only one element of the array here.
3323 for (; i
< t
->size
&& unlikely(t
->entries
[i
].threshold
<= usage
); i
++)
3324 eventfd_signal(t
->entries
[i
].eventfd
, 1);
3326 /* Update current_threshold */
3327 t
->current_threshold
= i
- 1;
3332 static void mem_cgroup_threshold(struct mem_cgroup
*memcg
)
3335 __mem_cgroup_threshold(memcg
, false);
3336 if (do_swap_account
)
3337 __mem_cgroup_threshold(memcg
, true);
3339 memcg
= parent_mem_cgroup(memcg
);
3343 static int compare_thresholds(const void *a
, const void *b
)
3345 const struct mem_cgroup_threshold
*_a
= a
;
3346 const struct mem_cgroup_threshold
*_b
= b
;
3348 if (_a
->threshold
> _b
->threshold
)
3351 if (_a
->threshold
< _b
->threshold
)
3357 static int mem_cgroup_oom_notify_cb(struct mem_cgroup
*memcg
)
3359 struct mem_cgroup_eventfd_list
*ev
;
3361 spin_lock(&memcg_oom_lock
);
3363 list_for_each_entry(ev
, &memcg
->oom_notify
, list
)
3364 eventfd_signal(ev
->eventfd
, 1);
3366 spin_unlock(&memcg_oom_lock
);
3370 static void mem_cgroup_oom_notify(struct mem_cgroup
*memcg
)
3372 struct mem_cgroup
*iter
;
3374 for_each_mem_cgroup_tree(iter
, memcg
)
3375 mem_cgroup_oom_notify_cb(iter
);
3378 static int __mem_cgroup_usage_register_event(struct mem_cgroup
*memcg
,
3379 struct eventfd_ctx
*eventfd
, const char *args
, enum res_type type
)
3381 struct mem_cgroup_thresholds
*thresholds
;
3382 struct mem_cgroup_threshold_ary
*new;
3383 unsigned long threshold
;
3384 unsigned long usage
;
3387 ret
= page_counter_memparse(args
, "-1", &threshold
);
3390 threshold
<<= PAGE_SHIFT
;
3392 mutex_lock(&memcg
->thresholds_lock
);
3395 thresholds
= &memcg
->thresholds
;
3396 usage
= mem_cgroup_usage(memcg
, false);
3397 } else if (type
== _MEMSWAP
) {
3398 thresholds
= &memcg
->memsw_thresholds
;
3399 usage
= mem_cgroup_usage(memcg
, true);
3403 /* Check if a threshold crossed before adding a new one */
3404 if (thresholds
->primary
)
3405 __mem_cgroup_threshold(memcg
, type
== _MEMSWAP
);
3407 size
= thresholds
->primary
? thresholds
->primary
->size
+ 1 : 1;
3409 /* Allocate memory for new array of thresholds */
3410 new = kmalloc(sizeof(*new) + size
* sizeof(struct mem_cgroup_threshold
),
3418 /* Copy thresholds (if any) to new array */
3419 if (thresholds
->primary
) {
3420 memcpy(new->entries
, thresholds
->primary
->entries
, (size
- 1) *
3421 sizeof(struct mem_cgroup_threshold
));
3424 /* Add new threshold */
3425 new->entries
[size
- 1].eventfd
= eventfd
;
3426 new->entries
[size
- 1].threshold
= threshold
;
3428 /* Sort thresholds. Registering of new threshold isn't time-critical */
3429 sort(new->entries
, size
, sizeof(struct mem_cgroup_threshold
),
3430 compare_thresholds
, NULL
);
3432 /* Find current threshold */
3433 new->current_threshold
= -1;
3434 for (i
= 0; i
< size
; i
++) {
3435 if (new->entries
[i
].threshold
<= usage
) {
3437 * new->current_threshold will not be used until
3438 * rcu_assign_pointer(), so it's safe to increment
3441 ++new->current_threshold
;
3446 /* Free old spare buffer and save old primary buffer as spare */
3447 kfree(thresholds
->spare
);
3448 thresholds
->spare
= thresholds
->primary
;
3450 rcu_assign_pointer(thresholds
->primary
, new);
3452 /* To be sure that nobody uses thresholds */
3456 mutex_unlock(&memcg
->thresholds_lock
);
3461 static int mem_cgroup_usage_register_event(struct mem_cgroup
*memcg
,
3462 struct eventfd_ctx
*eventfd
, const char *args
)
3464 return __mem_cgroup_usage_register_event(memcg
, eventfd
, args
, _MEM
);
3467 static int memsw_cgroup_usage_register_event(struct mem_cgroup
*memcg
,
3468 struct eventfd_ctx
*eventfd
, const char *args
)
3470 return __mem_cgroup_usage_register_event(memcg
, eventfd
, args
, _MEMSWAP
);
3473 static void __mem_cgroup_usage_unregister_event(struct mem_cgroup
*memcg
,
3474 struct eventfd_ctx
*eventfd
, enum res_type type
)
3476 struct mem_cgroup_thresholds
*thresholds
;
3477 struct mem_cgroup_threshold_ary
*new;
3478 unsigned long usage
;
3481 mutex_lock(&memcg
->thresholds_lock
);
3484 thresholds
= &memcg
->thresholds
;
3485 usage
= mem_cgroup_usage(memcg
, false);
3486 } else if (type
== _MEMSWAP
) {
3487 thresholds
= &memcg
->memsw_thresholds
;
3488 usage
= mem_cgroup_usage(memcg
, true);
3492 if (!thresholds
->primary
)
3495 /* Check if a threshold crossed before removing */
3496 __mem_cgroup_threshold(memcg
, type
== _MEMSWAP
);
3498 /* Calculate new number of threshold */
3500 for (i
= 0; i
< thresholds
->primary
->size
; i
++) {
3501 if (thresholds
->primary
->entries
[i
].eventfd
!= eventfd
)
3505 new = thresholds
->spare
;
3507 /* Set thresholds array to NULL if we don't have thresholds */
3516 /* Copy thresholds and find current threshold */
3517 new->current_threshold
= -1;
3518 for (i
= 0, j
= 0; i
< thresholds
->primary
->size
; i
++) {
3519 if (thresholds
->primary
->entries
[i
].eventfd
== eventfd
)
3522 new->entries
[j
] = thresholds
->primary
->entries
[i
];
3523 if (new->entries
[j
].threshold
<= usage
) {
3525 * new->current_threshold will not be used
3526 * until rcu_assign_pointer(), so it's safe to increment
3529 ++new->current_threshold
;
3535 /* Swap primary and spare array */
3536 thresholds
->spare
= thresholds
->primary
;
3537 /* If all events are unregistered, free the spare array */
3539 kfree(thresholds
->spare
);
3540 thresholds
->spare
= NULL
;
3543 rcu_assign_pointer(thresholds
->primary
, new);
3545 /* To be sure that nobody uses thresholds */
3548 mutex_unlock(&memcg
->thresholds_lock
);
3551 static void mem_cgroup_usage_unregister_event(struct mem_cgroup
*memcg
,
3552 struct eventfd_ctx
*eventfd
)
3554 return __mem_cgroup_usage_unregister_event(memcg
, eventfd
, _MEM
);
3557 static void memsw_cgroup_usage_unregister_event(struct mem_cgroup
*memcg
,
3558 struct eventfd_ctx
*eventfd
)
3560 return __mem_cgroup_usage_unregister_event(memcg
, eventfd
, _MEMSWAP
);
3563 static int mem_cgroup_oom_register_event(struct mem_cgroup
*memcg
,
3564 struct eventfd_ctx
*eventfd
, const char *args
)
3566 struct mem_cgroup_eventfd_list
*event
;
3568 event
= kmalloc(sizeof(*event
), GFP_KERNEL
);
3572 spin_lock(&memcg_oom_lock
);
3574 event
->eventfd
= eventfd
;
3575 list_add(&event
->list
, &memcg
->oom_notify
);
3577 /* already in OOM ? */
3578 if (memcg
->under_oom
)
3579 eventfd_signal(eventfd
, 1);
3580 spin_unlock(&memcg_oom_lock
);
3585 static void mem_cgroup_oom_unregister_event(struct mem_cgroup
*memcg
,
3586 struct eventfd_ctx
*eventfd
)
3588 struct mem_cgroup_eventfd_list
*ev
, *tmp
;
3590 spin_lock(&memcg_oom_lock
);
3592 list_for_each_entry_safe(ev
, tmp
, &memcg
->oom_notify
, list
) {
3593 if (ev
->eventfd
== eventfd
) {
3594 list_del(&ev
->list
);
3599 spin_unlock(&memcg_oom_lock
);
3602 static int mem_cgroup_oom_control_read(struct seq_file
*sf
, void *v
)
3604 struct mem_cgroup
*memcg
= mem_cgroup_from_css(seq_css(sf
));
3606 seq_printf(sf
, "oom_kill_disable %d\n", memcg
->oom_kill_disable
);
3607 seq_printf(sf
, "under_oom %d\n", (bool)memcg
->under_oom
);
3611 static int mem_cgroup_oom_control_write(struct cgroup_subsys_state
*css
,
3612 struct cftype
*cft
, u64 val
)
3614 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
3616 /* cannot set to root cgroup and only 0 and 1 are allowed */
3617 if (!css
->parent
|| !((val
== 0) || (val
== 1)))
3620 memcg
->oom_kill_disable
= val
;
3622 memcg_oom_recover(memcg
);
3627 #ifdef CONFIG_MEMCG_KMEM
3628 static int memcg_init_kmem(struct mem_cgroup
*memcg
, struct cgroup_subsys
*ss
)
3632 ret
= memcg_propagate_kmem(memcg
);
3636 return mem_cgroup_sockets_init(memcg
, ss
);
3639 static void memcg_deactivate_kmem(struct mem_cgroup
*memcg
)
3641 struct cgroup_subsys_state
*css
;
3642 struct mem_cgroup
*parent
, *child
;
3645 if (!memcg
->kmem_acct_active
)
3649 * Clear the 'active' flag before clearing memcg_caches arrays entries.
3650 * Since we take the slab_mutex in memcg_deactivate_kmem_caches(), it
3651 * guarantees no cache will be created for this cgroup after we are
3652 * done (see memcg_create_kmem_cache()).
3654 memcg
->kmem_acct_active
= false;
3656 memcg_deactivate_kmem_caches(memcg
);
3658 kmemcg_id
= memcg
->kmemcg_id
;
3659 BUG_ON(kmemcg_id
< 0);
3661 parent
= parent_mem_cgroup(memcg
);
3663 parent
= root_mem_cgroup
;
3666 * Change kmemcg_id of this cgroup and all its descendants to the
3667 * parent's id, and then move all entries from this cgroup's list_lrus
3668 * to ones of the parent. After we have finished, all list_lrus
3669 * corresponding to this cgroup are guaranteed to remain empty. The
3670 * ordering is imposed by list_lru_node->lock taken by
3671 * memcg_drain_all_list_lrus().
3673 css_for_each_descendant_pre(css
, &memcg
->css
) {
3674 child
= mem_cgroup_from_css(css
);
3675 BUG_ON(child
->kmemcg_id
!= kmemcg_id
);
3676 child
->kmemcg_id
= parent
->kmemcg_id
;
3677 if (!memcg
->use_hierarchy
)
3680 memcg_drain_all_list_lrus(kmemcg_id
, parent
->kmemcg_id
);
3682 memcg_free_cache_id(kmemcg_id
);
3685 static void memcg_destroy_kmem(struct mem_cgroup
*memcg
)
3687 if (memcg
->kmem_acct_activated
) {
3688 memcg_destroy_kmem_caches(memcg
);
3689 static_key_slow_dec(&memcg_kmem_enabled_key
);
3690 WARN_ON(page_counter_read(&memcg
->kmem
));
3692 mem_cgroup_sockets_destroy(memcg
);
3695 static int memcg_init_kmem(struct mem_cgroup
*memcg
, struct cgroup_subsys
*ss
)
3700 static void memcg_deactivate_kmem(struct mem_cgroup
*memcg
)
3704 static void memcg_destroy_kmem(struct mem_cgroup
*memcg
)
3709 #ifdef CONFIG_CGROUP_WRITEBACK
3711 struct list_head
*mem_cgroup_cgwb_list(struct mem_cgroup
*memcg
)
3713 return &memcg
->cgwb_list
;
3716 static int memcg_wb_domain_init(struct mem_cgroup
*memcg
, gfp_t gfp
)
3718 return wb_domain_init(&memcg
->cgwb_domain
, gfp
);
3721 static void memcg_wb_domain_exit(struct mem_cgroup
*memcg
)
3723 wb_domain_exit(&memcg
->cgwb_domain
);
3726 static void memcg_wb_domain_size_changed(struct mem_cgroup
*memcg
)
3728 wb_domain_size_changed(&memcg
->cgwb_domain
);
3731 struct wb_domain
*mem_cgroup_wb_domain(struct bdi_writeback
*wb
)
3733 struct mem_cgroup
*memcg
= mem_cgroup_from_css(wb
->memcg_css
);
3735 if (!memcg
->css
.parent
)
3738 return &memcg
->cgwb_domain
;
3742 * mem_cgroup_wb_stats - retrieve writeback related stats from its memcg
3743 * @wb: bdi_writeback in question
3744 * @pfilepages: out parameter for number of file pages
3745 * @pheadroom: out parameter for number of allocatable pages according to memcg
3746 * @pdirty: out parameter for number of dirty pages
3747 * @pwriteback: out parameter for number of pages under writeback
3749 * Determine the numbers of file, headroom, dirty, and writeback pages in
3750 * @wb's memcg. File, dirty and writeback are self-explanatory. Headroom
3751 * is a bit more involved.
3753 * A memcg's headroom is "min(max, high) - used". In the hierarchy, the
3754 * headroom is calculated as the lowest headroom of itself and the
3755 * ancestors. Note that this doesn't consider the actual amount of
3756 * available memory in the system. The caller should further cap
3757 * *@pheadroom accordingly.
3759 void mem_cgroup_wb_stats(struct bdi_writeback
*wb
, unsigned long *pfilepages
,
3760 unsigned long *pheadroom
, unsigned long *pdirty
,
3761 unsigned long *pwriteback
)
3763 struct mem_cgroup
*memcg
= mem_cgroup_from_css(wb
->memcg_css
);
3764 struct mem_cgroup
*parent
;
3766 *pdirty
= mem_cgroup_read_stat(memcg
, MEM_CGROUP_STAT_DIRTY
);
3768 /* this should eventually include NR_UNSTABLE_NFS */
3769 *pwriteback
= mem_cgroup_read_stat(memcg
, MEM_CGROUP_STAT_WRITEBACK
);
3770 *pfilepages
= mem_cgroup_nr_lru_pages(memcg
, (1 << LRU_INACTIVE_FILE
) |
3771 (1 << LRU_ACTIVE_FILE
));
3772 *pheadroom
= PAGE_COUNTER_MAX
;
3774 while ((parent
= parent_mem_cgroup(memcg
))) {
3775 unsigned long ceiling
= min(memcg
->memory
.limit
, memcg
->high
);
3776 unsigned long used
= page_counter_read(&memcg
->memory
);
3778 *pheadroom
= min(*pheadroom
, ceiling
- min(ceiling
, used
));
3783 #else /* CONFIG_CGROUP_WRITEBACK */
3785 static int memcg_wb_domain_init(struct mem_cgroup
*memcg
, gfp_t gfp
)
3790 static void memcg_wb_domain_exit(struct mem_cgroup
*memcg
)
3794 static void memcg_wb_domain_size_changed(struct mem_cgroup
*memcg
)
3798 #endif /* CONFIG_CGROUP_WRITEBACK */
3801 * DO NOT USE IN NEW FILES.
3803 * "cgroup.event_control" implementation.
3805 * This is way over-engineered. It tries to support fully configurable
3806 * events for each user. Such level of flexibility is completely
3807 * unnecessary especially in the light of the planned unified hierarchy.
3809 * Please deprecate this and replace with something simpler if at all
3814 * Unregister event and free resources.
3816 * Gets called from workqueue.
3818 static void memcg_event_remove(struct work_struct
*work
)
3820 struct mem_cgroup_event
*event
=
3821 container_of(work
, struct mem_cgroup_event
, remove
);
3822 struct mem_cgroup
*memcg
= event
->memcg
;
3824 remove_wait_queue(event
->wqh
, &event
->wait
);
3826 event
->unregister_event(memcg
, event
->eventfd
);
3828 /* Notify userspace the event is going away. */
3829 eventfd_signal(event
->eventfd
, 1);
3831 eventfd_ctx_put(event
->eventfd
);
3833 css_put(&memcg
->css
);
3837 * Gets called on POLLHUP on eventfd when user closes it.
3839 * Called with wqh->lock held and interrupts disabled.
3841 static int memcg_event_wake(wait_queue_t
*wait
, unsigned mode
,
3842 int sync
, void *key
)
3844 struct mem_cgroup_event
*event
=
3845 container_of(wait
, struct mem_cgroup_event
, wait
);
3846 struct mem_cgroup
*memcg
= event
->memcg
;
3847 unsigned long flags
= (unsigned long)key
;
3849 if (flags
& POLLHUP
) {
3851 * If the event has been detached at cgroup removal, we
3852 * can simply return knowing the other side will cleanup
3855 * We can't race against event freeing since the other
3856 * side will require wqh->lock via remove_wait_queue(),
3859 spin_lock(&memcg
->event_list_lock
);
3860 if (!list_empty(&event
->list
)) {
3861 list_del_init(&event
->list
);
3863 * We are in atomic context, but cgroup_event_remove()
3864 * may sleep, so we have to call it in workqueue.
3866 schedule_work(&event
->remove
);
3868 spin_unlock(&memcg
->event_list_lock
);
3874 static void memcg_event_ptable_queue_proc(struct file
*file
,
3875 wait_queue_head_t
*wqh
, poll_table
*pt
)
3877 struct mem_cgroup_event
*event
=
3878 container_of(pt
, struct mem_cgroup_event
, pt
);
3881 add_wait_queue(wqh
, &event
->wait
);
3885 * DO NOT USE IN NEW FILES.
3887 * Parse input and register new cgroup event handler.
3889 * Input must be in format '<event_fd> <control_fd> <args>'.
3890 * Interpretation of args is defined by control file implementation.
3892 static ssize_t
memcg_write_event_control(struct kernfs_open_file
*of
,
3893 char *buf
, size_t nbytes
, loff_t off
)
3895 struct cgroup_subsys_state
*css
= of_css(of
);
3896 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
3897 struct mem_cgroup_event
*event
;
3898 struct cgroup_subsys_state
*cfile_css
;
3899 unsigned int efd
, cfd
;
3906 buf
= strstrip(buf
);
3908 efd
= simple_strtoul(buf
, &endp
, 10);
3913 cfd
= simple_strtoul(buf
, &endp
, 10);
3914 if ((*endp
!= ' ') && (*endp
!= '\0'))
3918 event
= kzalloc(sizeof(*event
), GFP_KERNEL
);
3922 event
->memcg
= memcg
;
3923 INIT_LIST_HEAD(&event
->list
);
3924 init_poll_funcptr(&event
->pt
, memcg_event_ptable_queue_proc
);
3925 init_waitqueue_func_entry(&event
->wait
, memcg_event_wake
);
3926 INIT_WORK(&event
->remove
, memcg_event_remove
);
3934 event
->eventfd
= eventfd_ctx_fileget(efile
.file
);
3935 if (IS_ERR(event
->eventfd
)) {
3936 ret
= PTR_ERR(event
->eventfd
);
3943 goto out_put_eventfd
;
3946 /* the process need read permission on control file */
3947 /* AV: shouldn't we check that it's been opened for read instead? */
3948 ret
= inode_permission(file_inode(cfile
.file
), MAY_READ
);
3953 * Determine the event callbacks and set them in @event. This used
3954 * to be done via struct cftype but cgroup core no longer knows
3955 * about these events. The following is crude but the whole thing
3956 * is for compatibility anyway.
3958 * DO NOT ADD NEW FILES.
3960 name
= cfile
.file
->f_path
.dentry
->d_name
.name
;
3962 if (!strcmp(name
, "memory.usage_in_bytes")) {
3963 event
->register_event
= mem_cgroup_usage_register_event
;
3964 event
->unregister_event
= mem_cgroup_usage_unregister_event
;
3965 } else if (!strcmp(name
, "memory.oom_control")) {
3966 event
->register_event
= mem_cgroup_oom_register_event
;
3967 event
->unregister_event
= mem_cgroup_oom_unregister_event
;
3968 } else if (!strcmp(name
, "memory.pressure_level")) {
3969 event
->register_event
= vmpressure_register_event
;
3970 event
->unregister_event
= vmpressure_unregister_event
;
3971 } else if (!strcmp(name
, "memory.memsw.usage_in_bytes")) {
3972 event
->register_event
= memsw_cgroup_usage_register_event
;
3973 event
->unregister_event
= memsw_cgroup_usage_unregister_event
;
3980 * Verify @cfile should belong to @css. Also, remaining events are
3981 * automatically removed on cgroup destruction but the removal is
3982 * asynchronous, so take an extra ref on @css.
3984 cfile_css
= css_tryget_online_from_dir(cfile
.file
->f_path
.dentry
->d_parent
,
3985 &memory_cgrp_subsys
);
3987 if (IS_ERR(cfile_css
))
3989 if (cfile_css
!= css
) {
3994 ret
= event
->register_event(memcg
, event
->eventfd
, buf
);
3998 efile
.file
->f_op
->poll(efile
.file
, &event
->pt
);
4000 spin_lock(&memcg
->event_list_lock
);
4001 list_add(&event
->list
, &memcg
->event_list
);
4002 spin_unlock(&memcg
->event_list_lock
);
4014 eventfd_ctx_put(event
->eventfd
);
4023 static struct cftype mem_cgroup_legacy_files
[] = {
4025 .name
= "usage_in_bytes",
4026 .private = MEMFILE_PRIVATE(_MEM
, RES_USAGE
),
4027 .read_u64
= mem_cgroup_read_u64
,
4030 .name
= "max_usage_in_bytes",
4031 .private = MEMFILE_PRIVATE(_MEM
, RES_MAX_USAGE
),
4032 .write
= mem_cgroup_reset
,
4033 .read_u64
= mem_cgroup_read_u64
,
4036 .name
= "limit_in_bytes",
4037 .private = MEMFILE_PRIVATE(_MEM
, RES_LIMIT
),
4038 .write
= mem_cgroup_write
,
4039 .read_u64
= mem_cgroup_read_u64
,
4042 .name
= "soft_limit_in_bytes",
4043 .private = MEMFILE_PRIVATE(_MEM
, RES_SOFT_LIMIT
),
4044 .write
= mem_cgroup_write
,
4045 .read_u64
= mem_cgroup_read_u64
,
4049 .private = MEMFILE_PRIVATE(_MEM
, RES_FAILCNT
),
4050 .write
= mem_cgroup_reset
,
4051 .read_u64
= mem_cgroup_read_u64
,
4055 .seq_show
= memcg_stat_show
,
4058 .name
= "force_empty",
4059 .write
= mem_cgroup_force_empty_write
,
4062 .name
= "use_hierarchy",
4063 .write_u64
= mem_cgroup_hierarchy_write
,
4064 .read_u64
= mem_cgroup_hierarchy_read
,
4067 .name
= "cgroup.event_control", /* XXX: for compat */
4068 .write
= memcg_write_event_control
,
4069 .flags
= CFTYPE_NO_PREFIX
,
4073 .name
= "swappiness",
4074 .read_u64
= mem_cgroup_swappiness_read
,
4075 .write_u64
= mem_cgroup_swappiness_write
,
4078 .name
= "move_charge_at_immigrate",
4079 .read_u64
= mem_cgroup_move_charge_read
,
4080 .write_u64
= mem_cgroup_move_charge_write
,
4083 .name
= "oom_control",
4084 .seq_show
= mem_cgroup_oom_control_read
,
4085 .write_u64
= mem_cgroup_oom_control_write
,
4086 .private = MEMFILE_PRIVATE(_OOM_TYPE
, OOM_CONTROL
),
4089 .name
= "pressure_level",
4093 .name
= "numa_stat",
4094 .seq_show
= memcg_numa_stat_show
,
4097 #ifdef CONFIG_MEMCG_KMEM
4099 .name
= "kmem.limit_in_bytes",
4100 .private = MEMFILE_PRIVATE(_KMEM
, RES_LIMIT
),
4101 .write
= mem_cgroup_write
,
4102 .read_u64
= mem_cgroup_read_u64
,
4105 .name
= "kmem.usage_in_bytes",
4106 .private = MEMFILE_PRIVATE(_KMEM
, RES_USAGE
),
4107 .read_u64
= mem_cgroup_read_u64
,
4110 .name
= "kmem.failcnt",
4111 .private = MEMFILE_PRIVATE(_KMEM
, RES_FAILCNT
),
4112 .write
= mem_cgroup_reset
,
4113 .read_u64
= mem_cgroup_read_u64
,
4116 .name
= "kmem.max_usage_in_bytes",
4117 .private = MEMFILE_PRIVATE(_KMEM
, RES_MAX_USAGE
),
4118 .write
= mem_cgroup_reset
,
4119 .read_u64
= mem_cgroup_read_u64
,
4121 #ifdef CONFIG_SLABINFO
4123 .name
= "kmem.slabinfo",
4124 .seq_start
= slab_start
,
4125 .seq_next
= slab_next
,
4126 .seq_stop
= slab_stop
,
4127 .seq_show
= memcg_slab_show
,
4131 { }, /* terminate */
4134 static int alloc_mem_cgroup_per_zone_info(struct mem_cgroup
*memcg
, int node
)
4136 struct mem_cgroup_per_node
*pn
;
4137 struct mem_cgroup_per_zone
*mz
;
4138 int zone
, tmp
= node
;
4140 * This routine is called against possible nodes.
4141 * But it's BUG to call kmalloc() against offline node.
4143 * TODO: this routine can waste much memory for nodes which will
4144 * never be onlined. It's better to use memory hotplug callback
4147 if (!node_state(node
, N_NORMAL_MEMORY
))
4149 pn
= kzalloc_node(sizeof(*pn
), GFP_KERNEL
, tmp
);
4153 for (zone
= 0; zone
< MAX_NR_ZONES
; zone
++) {
4154 mz
= &pn
->zoneinfo
[zone
];
4155 lruvec_init(&mz
->lruvec
);
4156 mz
->usage_in_excess
= 0;
4157 mz
->on_tree
= false;
4160 memcg
->nodeinfo
[node
] = pn
;
4164 static void free_mem_cgroup_per_zone_info(struct mem_cgroup
*memcg
, int node
)
4166 kfree(memcg
->nodeinfo
[node
]);
4169 static struct mem_cgroup
*mem_cgroup_alloc(void)
4171 struct mem_cgroup
*memcg
;
4174 size
= sizeof(struct mem_cgroup
);
4175 size
+= nr_node_ids
* sizeof(struct mem_cgroup_per_node
*);
4177 memcg
= kzalloc(size
, GFP_KERNEL
);
4181 memcg
->stat
= alloc_percpu(struct mem_cgroup_stat_cpu
);
4185 if (memcg_wb_domain_init(memcg
, GFP_KERNEL
))
4191 free_percpu(memcg
->stat
);
4198 * At destroying mem_cgroup, references from swap_cgroup can remain.
4199 * (scanning all at force_empty is too costly...)
4201 * Instead of clearing all references at force_empty, we remember
4202 * the number of reference from swap_cgroup and free mem_cgroup when
4203 * it goes down to 0.
4205 * Removal of cgroup itself succeeds regardless of refs from swap.
4208 static void __mem_cgroup_free(struct mem_cgroup
*memcg
)
4212 mem_cgroup_remove_from_trees(memcg
);
4215 free_mem_cgroup_per_zone_info(memcg
, node
);
4217 free_percpu(memcg
->stat
);
4218 memcg_wb_domain_exit(memcg
);
4223 * Returns the parent mem_cgroup in memcgroup hierarchy with hierarchy enabled.
4225 struct mem_cgroup
*parent_mem_cgroup(struct mem_cgroup
*memcg
)
4227 if (!memcg
->memory
.parent
)
4229 return mem_cgroup_from_counter(memcg
->memory
.parent
, memory
);
4231 EXPORT_SYMBOL(parent_mem_cgroup
);
4233 static struct cgroup_subsys_state
* __ref
4234 mem_cgroup_css_alloc(struct cgroup_subsys_state
*parent_css
)
4236 struct mem_cgroup
*memcg
;
4237 long error
= -ENOMEM
;
4240 memcg
= mem_cgroup_alloc();
4242 return ERR_PTR(error
);
4245 if (alloc_mem_cgroup_per_zone_info(memcg
, node
))
4249 if (parent_css
== NULL
) {
4250 root_mem_cgroup
= memcg
;
4251 mem_cgroup_root_css
= &memcg
->css
;
4252 page_counter_init(&memcg
->memory
, NULL
);
4253 memcg
->high
= PAGE_COUNTER_MAX
;
4254 memcg
->soft_limit
= PAGE_COUNTER_MAX
;
4255 page_counter_init(&memcg
->memsw
, NULL
);
4256 page_counter_init(&memcg
->kmem
, NULL
);
4259 memcg
->last_scanned_node
= MAX_NUMNODES
;
4260 INIT_LIST_HEAD(&memcg
->oom_notify
);
4261 memcg
->move_charge_at_immigrate
= 0;
4262 mutex_init(&memcg
->thresholds_lock
);
4263 spin_lock_init(&memcg
->move_lock
);
4264 vmpressure_init(&memcg
->vmpressure
);
4265 INIT_LIST_HEAD(&memcg
->event_list
);
4266 spin_lock_init(&memcg
->event_list_lock
);
4267 #ifdef CONFIG_MEMCG_KMEM
4268 memcg
->kmemcg_id
= -1;
4270 #ifdef CONFIG_CGROUP_WRITEBACK
4271 INIT_LIST_HEAD(&memcg
->cgwb_list
);
4276 __mem_cgroup_free(memcg
);
4277 return ERR_PTR(error
);
4281 mem_cgroup_css_online(struct cgroup_subsys_state
*css
)
4283 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
4284 struct mem_cgroup
*parent
= mem_cgroup_from_css(css
->parent
);
4287 if (css
->id
> MEM_CGROUP_ID_MAX
)
4293 mutex_lock(&memcg_create_mutex
);
4295 memcg
->use_hierarchy
= parent
->use_hierarchy
;
4296 memcg
->oom_kill_disable
= parent
->oom_kill_disable
;
4297 memcg
->swappiness
= mem_cgroup_swappiness(parent
);
4299 if (parent
->use_hierarchy
) {
4300 page_counter_init(&memcg
->memory
, &parent
->memory
);
4301 memcg
->high
= PAGE_COUNTER_MAX
;
4302 memcg
->soft_limit
= PAGE_COUNTER_MAX
;
4303 page_counter_init(&memcg
->memsw
, &parent
->memsw
);
4304 page_counter_init(&memcg
->kmem
, &parent
->kmem
);
4307 * No need to take a reference to the parent because cgroup
4308 * core guarantees its existence.
4311 page_counter_init(&memcg
->memory
, NULL
);
4312 memcg
->high
= PAGE_COUNTER_MAX
;
4313 memcg
->soft_limit
= PAGE_COUNTER_MAX
;
4314 page_counter_init(&memcg
->memsw
, NULL
);
4315 page_counter_init(&memcg
->kmem
, NULL
);
4317 * Deeper hierachy with use_hierarchy == false doesn't make
4318 * much sense so let cgroup subsystem know about this
4319 * unfortunate state in our controller.
4321 if (parent
!= root_mem_cgroup
)
4322 memory_cgrp_subsys
.broken_hierarchy
= true;
4324 mutex_unlock(&memcg_create_mutex
);
4326 ret
= memcg_init_kmem(memcg
, &memory_cgrp_subsys
);
4331 * Make sure the memcg is initialized: mem_cgroup_iter()
4332 * orders reading memcg->initialized against its callers
4333 * reading the memcg members.
4335 smp_store_release(&memcg
->initialized
, 1);
4340 static void mem_cgroup_css_offline(struct cgroup_subsys_state
*css
)
4342 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
4343 struct mem_cgroup_event
*event
, *tmp
;
4346 * Unregister events and notify userspace.
4347 * Notify userspace about cgroup removing only after rmdir of cgroup
4348 * directory to avoid race between userspace and kernelspace.
4350 spin_lock(&memcg
->event_list_lock
);
4351 list_for_each_entry_safe(event
, tmp
, &memcg
->event_list
, list
) {
4352 list_del_init(&event
->list
);
4353 schedule_work(&event
->remove
);
4355 spin_unlock(&memcg
->event_list_lock
);
4357 vmpressure_cleanup(&memcg
->vmpressure
);
4359 memcg_deactivate_kmem(memcg
);
4361 wb_memcg_offline(memcg
);
4364 static void mem_cgroup_css_free(struct cgroup_subsys_state
*css
)
4366 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
4368 memcg_destroy_kmem(memcg
);
4369 __mem_cgroup_free(memcg
);
4373 * mem_cgroup_css_reset - reset the states of a mem_cgroup
4374 * @css: the target css
4376 * Reset the states of the mem_cgroup associated with @css. This is
4377 * invoked when the userland requests disabling on the default hierarchy
4378 * but the memcg is pinned through dependency. The memcg should stop
4379 * applying policies and should revert to the vanilla state as it may be
4380 * made visible again.
4382 * The current implementation only resets the essential configurations.
4383 * This needs to be expanded to cover all the visible parts.
4385 static void mem_cgroup_css_reset(struct cgroup_subsys_state
*css
)
4387 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
4389 mem_cgroup_resize_limit(memcg
, PAGE_COUNTER_MAX
);
4390 mem_cgroup_resize_memsw_limit(memcg
, PAGE_COUNTER_MAX
);
4391 memcg_update_kmem_limit(memcg
, PAGE_COUNTER_MAX
);
4393 memcg
->high
= PAGE_COUNTER_MAX
;
4394 memcg
->soft_limit
= PAGE_COUNTER_MAX
;
4395 memcg_wb_domain_size_changed(memcg
);
4399 /* Handlers for move charge at task migration. */
4400 static int mem_cgroup_do_precharge(unsigned long count
)
4404 /* Try a single bulk charge without reclaim first */
4405 ret
= try_charge(mc
.to
, GFP_KERNEL
& ~__GFP_WAIT
, count
);
4407 mc
.precharge
+= count
;
4410 if (ret
== -EINTR
) {
4411 cancel_charge(root_mem_cgroup
, count
);
4415 /* Try charges one by one with reclaim */
4417 ret
= try_charge(mc
.to
, GFP_KERNEL
& ~__GFP_NORETRY
, 1);
4419 * In case of failure, any residual charges against
4420 * mc.to will be dropped by mem_cgroup_clear_mc()
4421 * later on. However, cancel any charges that are
4422 * bypassed to root right away or they'll be lost.
4425 cancel_charge(root_mem_cgroup
, 1);
4435 * get_mctgt_type - get target type of moving charge
4436 * @vma: the vma the pte to be checked belongs
4437 * @addr: the address corresponding to the pte to be checked
4438 * @ptent: the pte to be checked
4439 * @target: the pointer the target page or swap ent will be stored(can be NULL)
4442 * 0(MC_TARGET_NONE): if the pte is not a target for move charge.
4443 * 1(MC_TARGET_PAGE): if the page corresponding to this pte is a target for
4444 * move charge. if @target is not NULL, the page is stored in target->page
4445 * with extra refcnt got(Callers should handle it).
4446 * 2(MC_TARGET_SWAP): if the swap entry corresponding to this pte is a
4447 * target for charge migration. if @target is not NULL, the entry is stored
4450 * Called with pte lock held.
4457 enum mc_target_type
{
4463 static struct page
*mc_handle_present_pte(struct vm_area_struct
*vma
,
4464 unsigned long addr
, pte_t ptent
)
4466 struct page
*page
= vm_normal_page(vma
, addr
, ptent
);
4468 if (!page
|| !page_mapped(page
))
4470 if (PageAnon(page
)) {
4471 if (!(mc
.flags
& MOVE_ANON
))
4474 if (!(mc
.flags
& MOVE_FILE
))
4477 if (!get_page_unless_zero(page
))
4484 static struct page
*mc_handle_swap_pte(struct vm_area_struct
*vma
,
4485 unsigned long addr
, pte_t ptent
, swp_entry_t
*entry
)
4487 struct page
*page
= NULL
;
4488 swp_entry_t ent
= pte_to_swp_entry(ptent
);
4490 if (!(mc
.flags
& MOVE_ANON
) || non_swap_entry(ent
))
4493 * Because lookup_swap_cache() updates some statistics counter,
4494 * we call find_get_page() with swapper_space directly.
4496 page
= find_get_page(swap_address_space(ent
), ent
.val
);
4497 if (do_swap_account
)
4498 entry
->val
= ent
.val
;
4503 static struct page
*mc_handle_swap_pte(struct vm_area_struct
*vma
,
4504 unsigned long addr
, pte_t ptent
, swp_entry_t
*entry
)
4510 static struct page
*mc_handle_file_pte(struct vm_area_struct
*vma
,
4511 unsigned long addr
, pte_t ptent
, swp_entry_t
*entry
)
4513 struct page
*page
= NULL
;
4514 struct address_space
*mapping
;
4517 if (!vma
->vm_file
) /* anonymous vma */
4519 if (!(mc
.flags
& MOVE_FILE
))
4522 mapping
= vma
->vm_file
->f_mapping
;
4523 pgoff
= linear_page_index(vma
, addr
);
4525 /* page is moved even if it's not RSS of this task(page-faulted). */
4527 /* shmem/tmpfs may report page out on swap: account for that too. */
4528 if (shmem_mapping(mapping
)) {
4529 page
= find_get_entry(mapping
, pgoff
);
4530 if (radix_tree_exceptional_entry(page
)) {
4531 swp_entry_t swp
= radix_to_swp_entry(page
);
4532 if (do_swap_account
)
4534 page
= find_get_page(swap_address_space(swp
), swp
.val
);
4537 page
= find_get_page(mapping
, pgoff
);
4539 page
= find_get_page(mapping
, pgoff
);
4545 * mem_cgroup_move_account - move account of the page
4547 * @nr_pages: number of regular pages (>1 for huge pages)
4548 * @from: mem_cgroup which the page is moved from.
4549 * @to: mem_cgroup which the page is moved to. @from != @to.
4551 * The caller must confirm following.
4552 * - page is not on LRU (isolate_page() is useful.)
4553 * - compound_lock is held when nr_pages > 1
4555 * This function doesn't do "charge" to new cgroup and doesn't do "uncharge"
4558 static int mem_cgroup_move_account(struct page
*page
,
4559 unsigned int nr_pages
,
4560 struct mem_cgroup
*from
,
4561 struct mem_cgroup
*to
)
4563 unsigned long flags
;
4567 VM_BUG_ON(from
== to
);
4568 VM_BUG_ON_PAGE(PageLRU(page
), page
);
4570 * The page is isolated from LRU. So, collapse function
4571 * will not handle this page. But page splitting can happen.
4572 * Do this check under compound_page_lock(). The caller should
4576 if (nr_pages
> 1 && !PageTransHuge(page
))
4580 * Prevent mem_cgroup_migrate() from looking at page->mem_cgroup
4581 * of its source page while we change it: page migration takes
4582 * both pages off the LRU, but page cache replacement doesn't.
4584 if (!trylock_page(page
))
4588 if (page
->mem_cgroup
!= from
)
4591 anon
= PageAnon(page
);
4593 spin_lock_irqsave(&from
->move_lock
, flags
);
4595 if (!anon
&& page_mapped(page
)) {
4596 __this_cpu_sub(from
->stat
->count
[MEM_CGROUP_STAT_FILE_MAPPED
],
4598 __this_cpu_add(to
->stat
->count
[MEM_CGROUP_STAT_FILE_MAPPED
],
4603 * move_lock grabbed above and caller set from->moving_account, so
4604 * mem_cgroup_update_page_stat() will serialize updates to PageDirty.
4605 * So mapping should be stable for dirty pages.
4607 if (!anon
&& PageDirty(page
)) {
4608 struct address_space
*mapping
= page_mapping(page
);
4610 if (mapping_cap_account_dirty(mapping
)) {
4611 __this_cpu_sub(from
->stat
->count
[MEM_CGROUP_STAT_DIRTY
],
4613 __this_cpu_add(to
->stat
->count
[MEM_CGROUP_STAT_DIRTY
],
4618 if (PageWriteback(page
)) {
4619 __this_cpu_sub(from
->stat
->count
[MEM_CGROUP_STAT_WRITEBACK
],
4621 __this_cpu_add(to
->stat
->count
[MEM_CGROUP_STAT_WRITEBACK
],
4626 * It is safe to change page->mem_cgroup here because the page
4627 * is referenced, charged, and isolated - we can't race with
4628 * uncharging, charging, migration, or LRU putback.
4631 /* caller should have done css_get */
4632 page
->mem_cgroup
= to
;
4633 spin_unlock_irqrestore(&from
->move_lock
, flags
);
4637 local_irq_disable();
4638 mem_cgroup_charge_statistics(to
, page
, nr_pages
);
4639 memcg_check_events(to
, page
);
4640 mem_cgroup_charge_statistics(from
, page
, -nr_pages
);
4641 memcg_check_events(from
, page
);
4649 static enum mc_target_type
get_mctgt_type(struct vm_area_struct
*vma
,
4650 unsigned long addr
, pte_t ptent
, union mc_target
*target
)
4652 struct page
*page
= NULL
;
4653 enum mc_target_type ret
= MC_TARGET_NONE
;
4654 swp_entry_t ent
= { .val
= 0 };
4656 if (pte_present(ptent
))
4657 page
= mc_handle_present_pte(vma
, addr
, ptent
);
4658 else if (is_swap_pte(ptent
))
4659 page
= mc_handle_swap_pte(vma
, addr
, ptent
, &ent
);
4660 else if (pte_none(ptent
))
4661 page
= mc_handle_file_pte(vma
, addr
, ptent
, &ent
);
4663 if (!page
&& !ent
.val
)
4667 * Do only loose check w/o serialization.
4668 * mem_cgroup_move_account() checks the page is valid or
4669 * not under LRU exclusion.
4671 if (page
->mem_cgroup
== mc
.from
) {
4672 ret
= MC_TARGET_PAGE
;
4674 target
->page
= page
;
4676 if (!ret
|| !target
)
4679 /* There is a swap entry and a page doesn't exist or isn't charged */
4680 if (ent
.val
&& !ret
&&
4681 mem_cgroup_id(mc
.from
) == lookup_swap_cgroup_id(ent
)) {
4682 ret
= MC_TARGET_SWAP
;
4689 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
4691 * We don't consider swapping or file mapped pages because THP does not
4692 * support them for now.
4693 * Caller should make sure that pmd_trans_huge(pmd) is true.
4695 static enum mc_target_type
get_mctgt_type_thp(struct vm_area_struct
*vma
,
4696 unsigned long addr
, pmd_t pmd
, union mc_target
*target
)
4698 struct page
*page
= NULL
;
4699 enum mc_target_type ret
= MC_TARGET_NONE
;
4701 page
= pmd_page(pmd
);
4702 VM_BUG_ON_PAGE(!page
|| !PageHead(page
), page
);
4703 if (!(mc
.flags
& MOVE_ANON
))
4705 if (page
->mem_cgroup
== mc
.from
) {
4706 ret
= MC_TARGET_PAGE
;
4709 target
->page
= page
;
4715 static inline enum mc_target_type
get_mctgt_type_thp(struct vm_area_struct
*vma
,
4716 unsigned long addr
, pmd_t pmd
, union mc_target
*target
)
4718 return MC_TARGET_NONE
;
4722 static int mem_cgroup_count_precharge_pte_range(pmd_t
*pmd
,
4723 unsigned long addr
, unsigned long end
,
4724 struct mm_walk
*walk
)
4726 struct vm_area_struct
*vma
= walk
->vma
;
4730 if (pmd_trans_huge_lock(pmd
, vma
, &ptl
) == 1) {
4731 if (get_mctgt_type_thp(vma
, addr
, *pmd
, NULL
) == MC_TARGET_PAGE
)
4732 mc
.precharge
+= HPAGE_PMD_NR
;
4737 if (pmd_trans_unstable(pmd
))
4739 pte
= pte_offset_map_lock(vma
->vm_mm
, pmd
, addr
, &ptl
);
4740 for (; addr
!= end
; pte
++, addr
+= PAGE_SIZE
)
4741 if (get_mctgt_type(vma
, addr
, *pte
, NULL
))
4742 mc
.precharge
++; /* increment precharge temporarily */
4743 pte_unmap_unlock(pte
- 1, ptl
);
4749 static unsigned long mem_cgroup_count_precharge(struct mm_struct
*mm
)
4751 unsigned long precharge
;
4753 struct mm_walk mem_cgroup_count_precharge_walk
= {
4754 .pmd_entry
= mem_cgroup_count_precharge_pte_range
,
4757 down_read(&mm
->mmap_sem
);
4758 walk_page_range(0, ~0UL, &mem_cgroup_count_precharge_walk
);
4759 up_read(&mm
->mmap_sem
);
4761 precharge
= mc
.precharge
;
4767 static int mem_cgroup_precharge_mc(struct mm_struct
*mm
)
4769 unsigned long precharge
= mem_cgroup_count_precharge(mm
);
4771 VM_BUG_ON(mc
.moving_task
);
4772 mc
.moving_task
= current
;
4773 return mem_cgroup_do_precharge(precharge
);
4776 /* cancels all extra charges on mc.from and mc.to, and wakes up all waiters. */
4777 static void __mem_cgroup_clear_mc(void)
4779 struct mem_cgroup
*from
= mc
.from
;
4780 struct mem_cgroup
*to
= mc
.to
;
4782 /* we must uncharge all the leftover precharges from mc.to */
4784 cancel_charge(mc
.to
, mc
.precharge
);
4788 * we didn't uncharge from mc.from at mem_cgroup_move_account(), so
4789 * we must uncharge here.
4791 if (mc
.moved_charge
) {
4792 cancel_charge(mc
.from
, mc
.moved_charge
);
4793 mc
.moved_charge
= 0;
4795 /* we must fixup refcnts and charges */
4796 if (mc
.moved_swap
) {
4797 /* uncharge swap account from the old cgroup */
4798 if (!mem_cgroup_is_root(mc
.from
))
4799 page_counter_uncharge(&mc
.from
->memsw
, mc
.moved_swap
);
4802 * we charged both to->memory and to->memsw, so we
4803 * should uncharge to->memory.
4805 if (!mem_cgroup_is_root(mc
.to
))
4806 page_counter_uncharge(&mc
.to
->memory
, mc
.moved_swap
);
4808 css_put_many(&mc
.from
->css
, mc
.moved_swap
);
4810 /* we've already done css_get(mc.to) */
4813 memcg_oom_recover(from
);
4814 memcg_oom_recover(to
);
4815 wake_up_all(&mc
.waitq
);
4818 static void mem_cgroup_clear_mc(void)
4821 * we must clear moving_task before waking up waiters at the end of
4824 mc
.moving_task
= NULL
;
4825 __mem_cgroup_clear_mc();
4826 spin_lock(&mc
.lock
);
4829 spin_unlock(&mc
.lock
);
4832 static int mem_cgroup_can_attach(struct cgroup_subsys_state
*css
,
4833 struct cgroup_taskset
*tset
)
4835 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
4836 struct mem_cgroup
*from
;
4837 struct task_struct
*p
;
4838 struct mm_struct
*mm
;
4839 unsigned long move_flags
;
4843 * We are now commited to this value whatever it is. Changes in this
4844 * tunable will only affect upcoming migrations, not the current one.
4845 * So we need to save it, and keep it going.
4847 move_flags
= READ_ONCE(memcg
->move_charge_at_immigrate
);
4851 p
= cgroup_taskset_first(tset
);
4852 from
= mem_cgroup_from_task(p
);
4854 VM_BUG_ON(from
== memcg
);
4856 mm
= get_task_mm(p
);
4859 /* We move charges only when we move a owner of the mm */
4860 if (mm
->owner
== p
) {
4863 VM_BUG_ON(mc
.precharge
);
4864 VM_BUG_ON(mc
.moved_charge
);
4865 VM_BUG_ON(mc
.moved_swap
);
4867 spin_lock(&mc
.lock
);
4870 mc
.flags
= move_flags
;
4871 spin_unlock(&mc
.lock
);
4872 /* We set mc.moving_task later */
4874 ret
= mem_cgroup_precharge_mc(mm
);
4876 mem_cgroup_clear_mc();
4882 static void mem_cgroup_cancel_attach(struct cgroup_subsys_state
*css
,
4883 struct cgroup_taskset
*tset
)
4886 mem_cgroup_clear_mc();
4889 static int mem_cgroup_move_charge_pte_range(pmd_t
*pmd
,
4890 unsigned long addr
, unsigned long end
,
4891 struct mm_walk
*walk
)
4894 struct vm_area_struct
*vma
= walk
->vma
;
4897 enum mc_target_type target_type
;
4898 union mc_target target
;
4902 * We don't take compound_lock() here but no race with splitting thp
4904 * - if pmd_trans_huge_lock() returns 1, the relevant thp is not
4905 * under splitting, which means there's no concurrent thp split,
4906 * - if another thread runs into split_huge_page() just after we
4907 * entered this if-block, the thread must wait for page table lock
4908 * to be unlocked in __split_huge_page_splitting(), where the main
4909 * part of thp split is not executed yet.
4911 if (pmd_trans_huge_lock(pmd
, vma
, &ptl
) == 1) {
4912 if (mc
.precharge
< HPAGE_PMD_NR
) {
4916 target_type
= get_mctgt_type_thp(vma
, addr
, *pmd
, &target
);
4917 if (target_type
== MC_TARGET_PAGE
) {
4919 if (!isolate_lru_page(page
)) {
4920 if (!mem_cgroup_move_account(page
, HPAGE_PMD_NR
,
4922 mc
.precharge
-= HPAGE_PMD_NR
;
4923 mc
.moved_charge
+= HPAGE_PMD_NR
;
4925 putback_lru_page(page
);
4933 if (pmd_trans_unstable(pmd
))
4936 pte
= pte_offset_map_lock(vma
->vm_mm
, pmd
, addr
, &ptl
);
4937 for (; addr
!= end
; addr
+= PAGE_SIZE
) {
4938 pte_t ptent
= *(pte
++);
4944 switch (get_mctgt_type(vma
, addr
, ptent
, &target
)) {
4945 case MC_TARGET_PAGE
:
4947 if (isolate_lru_page(page
))
4949 if (!mem_cgroup_move_account(page
, 1, mc
.from
, mc
.to
)) {
4951 /* we uncharge from mc.from later. */
4954 putback_lru_page(page
);
4955 put
: /* get_mctgt_type() gets the page */
4958 case MC_TARGET_SWAP
:
4960 if (!mem_cgroup_move_swap_account(ent
, mc
.from
, mc
.to
)) {
4962 /* we fixup refcnts and charges later. */
4970 pte_unmap_unlock(pte
- 1, ptl
);
4975 * We have consumed all precharges we got in can_attach().
4976 * We try charge one by one, but don't do any additional
4977 * charges to mc.to if we have failed in charge once in attach()
4980 ret
= mem_cgroup_do_precharge(1);
4988 static void mem_cgroup_move_charge(struct mm_struct
*mm
)
4990 struct mm_walk mem_cgroup_move_charge_walk
= {
4991 .pmd_entry
= mem_cgroup_move_charge_pte_range
,
4995 lru_add_drain_all();
4997 * Signal mem_cgroup_begin_page_stat() to take the memcg's
4998 * move_lock while we're moving its pages to another memcg.
4999 * Then wait for already started RCU-only updates to finish.
5001 atomic_inc(&mc
.from
->moving_account
);
5004 if (unlikely(!down_read_trylock(&mm
->mmap_sem
))) {
5006 * Someone who are holding the mmap_sem might be waiting in
5007 * waitq. So we cancel all extra charges, wake up all waiters,
5008 * and retry. Because we cancel precharges, we might not be able
5009 * to move enough charges, but moving charge is a best-effort
5010 * feature anyway, so it wouldn't be a big problem.
5012 __mem_cgroup_clear_mc();
5017 * When we have consumed all precharges and failed in doing
5018 * additional charge, the page walk just aborts.
5020 walk_page_range(0, ~0UL, &mem_cgroup_move_charge_walk
);
5021 up_read(&mm
->mmap_sem
);
5022 atomic_dec(&mc
.from
->moving_account
);
5025 static void mem_cgroup_move_task(struct cgroup_subsys_state
*css
,
5026 struct cgroup_taskset
*tset
)
5028 struct task_struct
*p
= cgroup_taskset_first(tset
);
5029 struct mm_struct
*mm
= get_task_mm(p
);
5033 mem_cgroup_move_charge(mm
);
5037 mem_cgroup_clear_mc();
5039 #else /* !CONFIG_MMU */
5040 static int mem_cgroup_can_attach(struct cgroup_subsys_state
*css
,
5041 struct cgroup_taskset
*tset
)
5045 static void mem_cgroup_cancel_attach(struct cgroup_subsys_state
*css
,
5046 struct cgroup_taskset
*tset
)
5049 static void mem_cgroup_move_task(struct cgroup_subsys_state
*css
,
5050 struct cgroup_taskset
*tset
)
5056 * Cgroup retains root cgroups across [un]mount cycles making it necessary
5057 * to verify whether we're attached to the default hierarchy on each mount
5060 static void mem_cgroup_bind(struct cgroup_subsys_state
*root_css
)
5063 * use_hierarchy is forced on the default hierarchy. cgroup core
5064 * guarantees that @root doesn't have any children, so turning it
5065 * on for the root memcg is enough.
5067 if (cgroup_on_dfl(root_css
->cgroup
))
5068 root_mem_cgroup
->use_hierarchy
= true;
5070 root_mem_cgroup
->use_hierarchy
= false;
5073 static u64
memory_current_read(struct cgroup_subsys_state
*css
,
5076 return mem_cgroup_usage(mem_cgroup_from_css(css
), false);
5079 static int memory_low_show(struct seq_file
*m
, void *v
)
5081 struct mem_cgroup
*memcg
= mem_cgroup_from_css(seq_css(m
));
5082 unsigned long low
= READ_ONCE(memcg
->low
);
5084 if (low
== PAGE_COUNTER_MAX
)
5085 seq_puts(m
, "max\n");
5087 seq_printf(m
, "%llu\n", (u64
)low
* PAGE_SIZE
);
5092 static ssize_t
memory_low_write(struct kernfs_open_file
*of
,
5093 char *buf
, size_t nbytes
, loff_t off
)
5095 struct mem_cgroup
*memcg
= mem_cgroup_from_css(of_css(of
));
5099 buf
= strstrip(buf
);
5100 err
= page_counter_memparse(buf
, "max", &low
);
5109 static int memory_high_show(struct seq_file
*m
, void *v
)
5111 struct mem_cgroup
*memcg
= mem_cgroup_from_css(seq_css(m
));
5112 unsigned long high
= READ_ONCE(memcg
->high
);
5114 if (high
== PAGE_COUNTER_MAX
)
5115 seq_puts(m
, "max\n");
5117 seq_printf(m
, "%llu\n", (u64
)high
* PAGE_SIZE
);
5122 static ssize_t
memory_high_write(struct kernfs_open_file
*of
,
5123 char *buf
, size_t nbytes
, loff_t off
)
5125 struct mem_cgroup
*memcg
= mem_cgroup_from_css(of_css(of
));
5129 buf
= strstrip(buf
);
5130 err
= page_counter_memparse(buf
, "max", &high
);
5136 memcg_wb_domain_size_changed(memcg
);
5140 static int memory_max_show(struct seq_file
*m
, void *v
)
5142 struct mem_cgroup
*memcg
= mem_cgroup_from_css(seq_css(m
));
5143 unsigned long max
= READ_ONCE(memcg
->memory
.limit
);
5145 if (max
== PAGE_COUNTER_MAX
)
5146 seq_puts(m
, "max\n");
5148 seq_printf(m
, "%llu\n", (u64
)max
* PAGE_SIZE
);
5153 static ssize_t
memory_max_write(struct kernfs_open_file
*of
,
5154 char *buf
, size_t nbytes
, loff_t off
)
5156 struct mem_cgroup
*memcg
= mem_cgroup_from_css(of_css(of
));
5160 buf
= strstrip(buf
);
5161 err
= page_counter_memparse(buf
, "max", &max
);
5165 err
= mem_cgroup_resize_limit(memcg
, max
);
5169 memcg_wb_domain_size_changed(memcg
);
5173 static int memory_events_show(struct seq_file
*m
, void *v
)
5175 struct mem_cgroup
*memcg
= mem_cgroup_from_css(seq_css(m
));
5177 seq_printf(m
, "low %lu\n", mem_cgroup_read_events(memcg
, MEMCG_LOW
));
5178 seq_printf(m
, "high %lu\n", mem_cgroup_read_events(memcg
, MEMCG_HIGH
));
5179 seq_printf(m
, "max %lu\n", mem_cgroup_read_events(memcg
, MEMCG_MAX
));
5180 seq_printf(m
, "oom %lu\n", mem_cgroup_read_events(memcg
, MEMCG_OOM
));
5185 static struct cftype memory_files
[] = {
5188 .read_u64
= memory_current_read
,
5192 .flags
= CFTYPE_NOT_ON_ROOT
,
5193 .seq_show
= memory_low_show
,
5194 .write
= memory_low_write
,
5198 .flags
= CFTYPE_NOT_ON_ROOT
,
5199 .seq_show
= memory_high_show
,
5200 .write
= memory_high_write
,
5204 .flags
= CFTYPE_NOT_ON_ROOT
,
5205 .seq_show
= memory_max_show
,
5206 .write
= memory_max_write
,
5210 .flags
= CFTYPE_NOT_ON_ROOT
,
5211 .seq_show
= memory_events_show
,
5216 struct cgroup_subsys memory_cgrp_subsys
= {
5217 .css_alloc
= mem_cgroup_css_alloc
,
5218 .css_online
= mem_cgroup_css_online
,
5219 .css_offline
= mem_cgroup_css_offline
,
5220 .css_free
= mem_cgroup_css_free
,
5221 .css_reset
= mem_cgroup_css_reset
,
5222 .can_attach
= mem_cgroup_can_attach
,
5223 .cancel_attach
= mem_cgroup_cancel_attach
,
5224 .attach
= mem_cgroup_move_task
,
5225 .bind
= mem_cgroup_bind
,
5226 .dfl_cftypes
= memory_files
,
5227 .legacy_cftypes
= mem_cgroup_legacy_files
,
5232 * mem_cgroup_low - check if memory consumption is below the normal range
5233 * @root: the highest ancestor to consider
5234 * @memcg: the memory cgroup to check
5236 * Returns %true if memory consumption of @memcg, and that of all
5237 * configurable ancestors up to @root, is below the normal range.
5239 bool mem_cgroup_low(struct mem_cgroup
*root
, struct mem_cgroup
*memcg
)
5241 if (mem_cgroup_disabled())
5245 * The toplevel group doesn't have a configurable range, so
5246 * it's never low when looked at directly, and it is not
5247 * considered an ancestor when assessing the hierarchy.
5250 if (memcg
== root_mem_cgroup
)
5253 if (page_counter_read(&memcg
->memory
) >= memcg
->low
)
5256 while (memcg
!= root
) {
5257 memcg
= parent_mem_cgroup(memcg
);
5259 if (memcg
== root_mem_cgroup
)
5262 if (page_counter_read(&memcg
->memory
) >= memcg
->low
)
5269 * mem_cgroup_try_charge - try charging a page
5270 * @page: page to charge
5271 * @mm: mm context of the victim
5272 * @gfp_mask: reclaim mode
5273 * @memcgp: charged memcg return
5275 * Try to charge @page to the memcg that @mm belongs to, reclaiming
5276 * pages according to @gfp_mask if necessary.
5278 * Returns 0 on success, with *@memcgp pointing to the charged memcg.
5279 * Otherwise, an error code is returned.
5281 * After page->mapping has been set up, the caller must finalize the
5282 * charge with mem_cgroup_commit_charge(). Or abort the transaction
5283 * with mem_cgroup_cancel_charge() in case page instantiation fails.
5285 int mem_cgroup_try_charge(struct page
*page
, struct mm_struct
*mm
,
5286 gfp_t gfp_mask
, struct mem_cgroup
**memcgp
)
5288 struct mem_cgroup
*memcg
= NULL
;
5289 unsigned int nr_pages
= 1;
5292 if (mem_cgroup_disabled())
5295 if (PageSwapCache(page
)) {
5297 * Every swap fault against a single page tries to charge the
5298 * page, bail as early as possible. shmem_unuse() encounters
5299 * already charged pages, too. The USED bit is protected by
5300 * the page lock, which serializes swap cache removal, which
5301 * in turn serializes uncharging.
5303 VM_BUG_ON_PAGE(!PageLocked(page
), page
);
5304 if (page
->mem_cgroup
)
5307 if (do_swap_account
) {
5308 swp_entry_t ent
= { .val
= page_private(page
), };
5309 unsigned short id
= lookup_swap_cgroup_id(ent
);
5312 memcg
= mem_cgroup_from_id(id
);
5313 if (memcg
&& !css_tryget_online(&memcg
->css
))
5319 if (PageTransHuge(page
)) {
5320 nr_pages
<<= compound_order(page
);
5321 VM_BUG_ON_PAGE(!PageTransHuge(page
), page
);
5325 memcg
= get_mem_cgroup_from_mm(mm
);
5327 ret
= try_charge(memcg
, gfp_mask
, nr_pages
);
5329 css_put(&memcg
->css
);
5331 if (ret
== -EINTR
) {
5332 memcg
= root_mem_cgroup
;
5341 * mem_cgroup_commit_charge - commit a page charge
5342 * @page: page to charge
5343 * @memcg: memcg to charge the page to
5344 * @lrucare: page might be on LRU already
5346 * Finalize a charge transaction started by mem_cgroup_try_charge(),
5347 * after page->mapping has been set up. This must happen atomically
5348 * as part of the page instantiation, i.e. under the page table lock
5349 * for anonymous pages, under the page lock for page and swap cache.
5351 * In addition, the page must not be on the LRU during the commit, to
5352 * prevent racing with task migration. If it might be, use @lrucare.
5354 * Use mem_cgroup_cancel_charge() to cancel the transaction instead.
5356 void mem_cgroup_commit_charge(struct page
*page
, struct mem_cgroup
*memcg
,
5359 unsigned int nr_pages
= 1;
5361 VM_BUG_ON_PAGE(!page
->mapping
, page
);
5362 VM_BUG_ON_PAGE(PageLRU(page
) && !lrucare
, page
);
5364 if (mem_cgroup_disabled())
5367 * Swap faults will attempt to charge the same page multiple
5368 * times. But reuse_swap_page() might have removed the page
5369 * from swapcache already, so we can't check PageSwapCache().
5374 commit_charge(page
, memcg
, lrucare
);
5376 if (PageTransHuge(page
)) {
5377 nr_pages
<<= compound_order(page
);
5378 VM_BUG_ON_PAGE(!PageTransHuge(page
), page
);
5381 local_irq_disable();
5382 mem_cgroup_charge_statistics(memcg
, page
, nr_pages
);
5383 memcg_check_events(memcg
, page
);
5386 if (do_swap_account
&& PageSwapCache(page
)) {
5387 swp_entry_t entry
= { .val
= page_private(page
) };
5389 * The swap entry might not get freed for a long time,
5390 * let's not wait for it. The page already received a
5391 * memory+swap charge, drop the swap entry duplicate.
5393 mem_cgroup_uncharge_swap(entry
);
5398 * mem_cgroup_cancel_charge - cancel a page charge
5399 * @page: page to charge
5400 * @memcg: memcg to charge the page to
5402 * Cancel a charge transaction started by mem_cgroup_try_charge().
5404 void mem_cgroup_cancel_charge(struct page
*page
, struct mem_cgroup
*memcg
)
5406 unsigned int nr_pages
= 1;
5408 if (mem_cgroup_disabled())
5411 * Swap faults will attempt to charge the same page multiple
5412 * times. But reuse_swap_page() might have removed the page
5413 * from swapcache already, so we can't check PageSwapCache().
5418 if (PageTransHuge(page
)) {
5419 nr_pages
<<= compound_order(page
);
5420 VM_BUG_ON_PAGE(!PageTransHuge(page
), page
);
5423 cancel_charge(memcg
, nr_pages
);
5426 static void uncharge_batch(struct mem_cgroup
*memcg
, unsigned long pgpgout
,
5427 unsigned long nr_anon
, unsigned long nr_file
,
5428 unsigned long nr_huge
, struct page
*dummy_page
)
5430 unsigned long nr_pages
= nr_anon
+ nr_file
;
5431 unsigned long flags
;
5433 if (!mem_cgroup_is_root(memcg
)) {
5434 page_counter_uncharge(&memcg
->memory
, nr_pages
);
5435 if (do_swap_account
)
5436 page_counter_uncharge(&memcg
->memsw
, nr_pages
);
5437 memcg_oom_recover(memcg
);
5440 local_irq_save(flags
);
5441 __this_cpu_sub(memcg
->stat
->count
[MEM_CGROUP_STAT_RSS
], nr_anon
);
5442 __this_cpu_sub(memcg
->stat
->count
[MEM_CGROUP_STAT_CACHE
], nr_file
);
5443 __this_cpu_sub(memcg
->stat
->count
[MEM_CGROUP_STAT_RSS_HUGE
], nr_huge
);
5444 __this_cpu_add(memcg
->stat
->events
[MEM_CGROUP_EVENTS_PGPGOUT
], pgpgout
);
5445 __this_cpu_add(memcg
->stat
->nr_page_events
, nr_pages
);
5446 memcg_check_events(memcg
, dummy_page
);
5447 local_irq_restore(flags
);
5449 if (!mem_cgroup_is_root(memcg
))
5450 css_put_many(&memcg
->css
, nr_pages
);
5453 static void uncharge_list(struct list_head
*page_list
)
5455 struct mem_cgroup
*memcg
= NULL
;
5456 unsigned long nr_anon
= 0;
5457 unsigned long nr_file
= 0;
5458 unsigned long nr_huge
= 0;
5459 unsigned long pgpgout
= 0;
5460 struct list_head
*next
;
5463 next
= page_list
->next
;
5465 unsigned int nr_pages
= 1;
5467 page
= list_entry(next
, struct page
, lru
);
5468 next
= page
->lru
.next
;
5470 VM_BUG_ON_PAGE(PageLRU(page
), page
);
5471 VM_BUG_ON_PAGE(page_count(page
), page
);
5473 if (!page
->mem_cgroup
)
5477 * Nobody should be changing or seriously looking at
5478 * page->mem_cgroup at this point, we have fully
5479 * exclusive access to the page.
5482 if (memcg
!= page
->mem_cgroup
) {
5484 uncharge_batch(memcg
, pgpgout
, nr_anon
, nr_file
,
5486 pgpgout
= nr_anon
= nr_file
= nr_huge
= 0;
5488 memcg
= page
->mem_cgroup
;
5491 if (PageTransHuge(page
)) {
5492 nr_pages
<<= compound_order(page
);
5493 VM_BUG_ON_PAGE(!PageTransHuge(page
), page
);
5494 nr_huge
+= nr_pages
;
5498 nr_anon
+= nr_pages
;
5500 nr_file
+= nr_pages
;
5502 page
->mem_cgroup
= NULL
;
5505 } while (next
!= page_list
);
5508 uncharge_batch(memcg
, pgpgout
, nr_anon
, nr_file
,
5513 * mem_cgroup_uncharge - uncharge a page
5514 * @page: page to uncharge
5516 * Uncharge a page previously charged with mem_cgroup_try_charge() and
5517 * mem_cgroup_commit_charge().
5519 void mem_cgroup_uncharge(struct page
*page
)
5521 if (mem_cgroup_disabled())
5524 /* Don't touch page->lru of any random page, pre-check: */
5525 if (!page
->mem_cgroup
)
5528 INIT_LIST_HEAD(&page
->lru
);
5529 uncharge_list(&page
->lru
);
5533 * mem_cgroup_uncharge_list - uncharge a list of page
5534 * @page_list: list of pages to uncharge
5536 * Uncharge a list of pages previously charged with
5537 * mem_cgroup_try_charge() and mem_cgroup_commit_charge().
5539 void mem_cgroup_uncharge_list(struct list_head
*page_list
)
5541 if (mem_cgroup_disabled())
5544 if (!list_empty(page_list
))
5545 uncharge_list(page_list
);
5549 * mem_cgroup_migrate - migrate a charge to another page
5550 * @oldpage: currently charged page
5551 * @newpage: page to transfer the charge to
5552 * @lrucare: either or both pages might be on the LRU already
5554 * Migrate the charge from @oldpage to @newpage.
5556 * Both pages must be locked, @newpage->mapping must be set up.
5558 void mem_cgroup_migrate(struct page
*oldpage
, struct page
*newpage
,
5561 struct mem_cgroup
*memcg
;
5564 VM_BUG_ON_PAGE(!PageLocked(oldpage
), oldpage
);
5565 VM_BUG_ON_PAGE(!PageLocked(newpage
), newpage
);
5566 VM_BUG_ON_PAGE(!lrucare
&& PageLRU(oldpage
), oldpage
);
5567 VM_BUG_ON_PAGE(!lrucare
&& PageLRU(newpage
), newpage
);
5568 VM_BUG_ON_PAGE(PageAnon(oldpage
) != PageAnon(newpage
), newpage
);
5569 VM_BUG_ON_PAGE(PageTransHuge(oldpage
) != PageTransHuge(newpage
),
5572 if (mem_cgroup_disabled())
5575 /* Page cache replacement: new page already charged? */
5576 if (newpage
->mem_cgroup
)
5580 * Swapcache readahead pages can get migrated before being
5581 * charged, and migration from compaction can happen to an
5582 * uncharged page when the PFN walker finds a page that
5583 * reclaim just put back on the LRU but has not released yet.
5585 memcg
= oldpage
->mem_cgroup
;
5590 lock_page_lru(oldpage
, &isolated
);
5592 oldpage
->mem_cgroup
= NULL
;
5595 unlock_page_lru(oldpage
, isolated
);
5597 commit_charge(newpage
, memcg
, lrucare
);
5601 * subsys_initcall() for memory controller.
5603 * Some parts like hotcpu_notifier() have to be initialized from this context
5604 * because of lock dependencies (cgroup_lock -> cpu hotplug) but basically
5605 * everything that doesn't depend on a specific mem_cgroup structure should
5606 * be initialized from here.
5608 static int __init
mem_cgroup_init(void)
5612 hotcpu_notifier(memcg_cpu_hotplug_callback
, 0);
5614 for_each_possible_cpu(cpu
)
5615 INIT_WORK(&per_cpu_ptr(&memcg_stock
, cpu
)->work
,
5618 for_each_node(node
) {
5619 struct mem_cgroup_tree_per_node
*rtpn
;
5622 rtpn
= kzalloc_node(sizeof(*rtpn
), GFP_KERNEL
,
5623 node_online(node
) ? node
: NUMA_NO_NODE
);
5625 for (zone
= 0; zone
< MAX_NR_ZONES
; zone
++) {
5626 struct mem_cgroup_tree_per_zone
*rtpz
;
5628 rtpz
= &rtpn
->rb_tree_per_zone
[zone
];
5629 rtpz
->rb_root
= RB_ROOT
;
5630 spin_lock_init(&rtpz
->lock
);
5632 soft_limit_tree
.rb_tree_per_node
[node
] = rtpn
;
5637 subsys_initcall(mem_cgroup_init
);
5639 #ifdef CONFIG_MEMCG_SWAP
5641 * mem_cgroup_swapout - transfer a memsw charge to swap
5642 * @page: page whose memsw charge to transfer
5643 * @entry: swap entry to move the charge to
5645 * Transfer the memsw charge of @page to @entry.
5647 void mem_cgroup_swapout(struct page
*page
, swp_entry_t entry
)
5649 struct mem_cgroup
*memcg
;
5650 unsigned short oldid
;
5652 VM_BUG_ON_PAGE(PageLRU(page
), page
);
5653 VM_BUG_ON_PAGE(page_count(page
), page
);
5655 if (!do_swap_account
)
5658 memcg
= page
->mem_cgroup
;
5660 /* Readahead page, never charged */
5664 oldid
= swap_cgroup_record(entry
, mem_cgroup_id(memcg
));
5665 VM_BUG_ON_PAGE(oldid
, page
);
5666 mem_cgroup_swap_statistics(memcg
, true);
5668 page
->mem_cgroup
= NULL
;
5670 if (!mem_cgroup_is_root(memcg
))
5671 page_counter_uncharge(&memcg
->memory
, 1);
5674 * Interrupts should be disabled here because the caller holds the
5675 * mapping->tree_lock lock which is taken with interrupts-off. It is
5676 * important here to have the interrupts disabled because it is the
5677 * only synchronisation we have for udpating the per-CPU variables.
5679 VM_BUG_ON(!irqs_disabled());
5680 mem_cgroup_charge_statistics(memcg
, page
, -1);
5681 memcg_check_events(memcg
, page
);
5685 * mem_cgroup_uncharge_swap - uncharge a swap entry
5686 * @entry: swap entry to uncharge
5688 * Drop the memsw charge associated with @entry.
5690 void mem_cgroup_uncharge_swap(swp_entry_t entry
)
5692 struct mem_cgroup
*memcg
;
5695 if (!do_swap_account
)
5698 id
= swap_cgroup_record(entry
, 0);
5700 memcg
= mem_cgroup_from_id(id
);
5702 if (!mem_cgroup_is_root(memcg
))
5703 page_counter_uncharge(&memcg
->memsw
, 1);
5704 mem_cgroup_swap_statistics(memcg
, false);
5705 css_put(&memcg
->css
);
5710 /* for remember boot option*/
5711 #ifdef CONFIG_MEMCG_SWAP_ENABLED
5712 static int really_do_swap_account __initdata
= 1;
5714 static int really_do_swap_account __initdata
;
5717 static int __init
enable_swap_account(char *s
)
5719 if (!strcmp(s
, "1"))
5720 really_do_swap_account
= 1;
5721 else if (!strcmp(s
, "0"))
5722 really_do_swap_account
= 0;
5725 __setup("swapaccount=", enable_swap_account
);
5727 static struct cftype memsw_cgroup_files
[] = {
5729 .name
= "memsw.usage_in_bytes",
5730 .private = MEMFILE_PRIVATE(_MEMSWAP
, RES_USAGE
),
5731 .read_u64
= mem_cgroup_read_u64
,
5734 .name
= "memsw.max_usage_in_bytes",
5735 .private = MEMFILE_PRIVATE(_MEMSWAP
, RES_MAX_USAGE
),
5736 .write
= mem_cgroup_reset
,
5737 .read_u64
= mem_cgroup_read_u64
,
5740 .name
= "memsw.limit_in_bytes",
5741 .private = MEMFILE_PRIVATE(_MEMSWAP
, RES_LIMIT
),
5742 .write
= mem_cgroup_write
,
5743 .read_u64
= mem_cgroup_read_u64
,
5746 .name
= "memsw.failcnt",
5747 .private = MEMFILE_PRIVATE(_MEMSWAP
, RES_FAILCNT
),
5748 .write
= mem_cgroup_reset
,
5749 .read_u64
= mem_cgroup_read_u64
,
5751 { }, /* terminate */
5754 static int __init
mem_cgroup_swap_init(void)
5756 if (!mem_cgroup_disabled() && really_do_swap_account
) {
5757 do_swap_account
= 1;
5758 WARN_ON(cgroup_add_legacy_cftypes(&memory_cgrp_subsys
,
5759 memsw_cgroup_files
));
5763 subsys_initcall(mem_cgroup_swap_init
);
5765 #endif /* CONFIG_MEMCG_SWAP */