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>
65 #include <linux/tracehook.h>
69 #include <net/tcp_memcontrol.h>
72 #include <asm/uaccess.h>
74 #include <trace/events/vmscan.h>
76 struct cgroup_subsys memory_cgrp_subsys __read_mostly
;
77 EXPORT_SYMBOL(memory_cgrp_subsys
);
79 struct mem_cgroup
*root_mem_cgroup __read_mostly
;
81 #define MEM_CGROUP_RECLAIM_RETRIES 5
83 /* Whether the swap controller is active */
84 #ifdef CONFIG_MEMCG_SWAP
85 int do_swap_account __read_mostly
;
87 #define do_swap_account 0
90 static const char * const mem_cgroup_stat_names
[] = {
100 static const char * const mem_cgroup_events_names
[] = {
107 static const char * const mem_cgroup_lru_names
[] = {
115 #define THRESHOLDS_EVENTS_TARGET 128
116 #define SOFTLIMIT_EVENTS_TARGET 1024
117 #define NUMAINFO_EVENTS_TARGET 1024
120 * Cgroups above their limits are maintained in a RB-Tree, independent of
121 * their hierarchy representation
124 struct mem_cgroup_tree_per_zone
{
125 struct rb_root rb_root
;
129 struct mem_cgroup_tree_per_node
{
130 struct mem_cgroup_tree_per_zone rb_tree_per_zone
[MAX_NR_ZONES
];
133 struct mem_cgroup_tree
{
134 struct mem_cgroup_tree_per_node
*rb_tree_per_node
[MAX_NUMNODES
];
137 static struct mem_cgroup_tree soft_limit_tree __read_mostly
;
140 struct mem_cgroup_eventfd_list
{
141 struct list_head list
;
142 struct eventfd_ctx
*eventfd
;
146 * cgroup_event represents events which userspace want to receive.
148 struct mem_cgroup_event
{
150 * memcg which the event belongs to.
152 struct mem_cgroup
*memcg
;
154 * eventfd to signal userspace about the event.
156 struct eventfd_ctx
*eventfd
;
158 * Each of these stored in a list by the cgroup.
160 struct list_head list
;
162 * register_event() callback will be used to add new userspace
163 * waiter for changes related to this event. Use eventfd_signal()
164 * on eventfd to send notification to userspace.
166 int (*register_event
)(struct mem_cgroup
*memcg
,
167 struct eventfd_ctx
*eventfd
, const char *args
);
169 * unregister_event() callback will be called when userspace closes
170 * the eventfd or on cgroup removing. This callback must be set,
171 * if you want provide notification functionality.
173 void (*unregister_event
)(struct mem_cgroup
*memcg
,
174 struct eventfd_ctx
*eventfd
);
176 * All fields below needed to unregister event when
177 * userspace closes eventfd.
180 wait_queue_head_t
*wqh
;
182 struct work_struct remove
;
185 static void mem_cgroup_threshold(struct mem_cgroup
*memcg
);
186 static void mem_cgroup_oom_notify(struct mem_cgroup
*memcg
);
188 /* Stuffs for move charges at task migration. */
190 * Types of charges to be moved.
192 #define MOVE_ANON 0x1U
193 #define MOVE_FILE 0x2U
194 #define MOVE_MASK (MOVE_ANON | MOVE_FILE)
196 /* "mc" and its members are protected by cgroup_mutex */
197 static struct move_charge_struct
{
198 spinlock_t lock
; /* for from, to */
199 struct mem_cgroup
*from
;
200 struct mem_cgroup
*to
;
202 unsigned long precharge
;
203 unsigned long moved_charge
;
204 unsigned long moved_swap
;
205 struct task_struct
*moving_task
; /* a task moving charges */
206 wait_queue_head_t waitq
; /* a waitq for other context */
208 .lock
= __SPIN_LOCK_UNLOCKED(mc
.lock
),
209 .waitq
= __WAIT_QUEUE_HEAD_INITIALIZER(mc
.waitq
),
213 * Maximum loops in mem_cgroup_hierarchical_reclaim(), used for soft
214 * limit reclaim to prevent infinite loops, if they ever occur.
216 #define MEM_CGROUP_MAX_RECLAIM_LOOPS 100
217 #define MEM_CGROUP_MAX_SOFT_LIMIT_RECLAIM_LOOPS 2
220 MEM_CGROUP_CHARGE_TYPE_CACHE
= 0,
221 MEM_CGROUP_CHARGE_TYPE_ANON
,
222 MEM_CGROUP_CHARGE_TYPE_SWAPOUT
, /* for accounting swapcache */
223 MEM_CGROUP_CHARGE_TYPE_DROP
, /* a page was unused swap cache */
227 /* for encoding cft->private value on file */
235 #define MEMFILE_PRIVATE(x, val) ((x) << 16 | (val))
236 #define MEMFILE_TYPE(val) ((val) >> 16 & 0xffff)
237 #define MEMFILE_ATTR(val) ((val) & 0xffff)
238 /* Used for OOM nofiier */
239 #define OOM_CONTROL (0)
242 * The memcg_create_mutex will be held whenever a new cgroup is created.
243 * As a consequence, any change that needs to protect against new child cgroups
244 * appearing has to hold it as well.
246 static DEFINE_MUTEX(memcg_create_mutex
);
248 /* Some nice accessors for the vmpressure. */
249 struct vmpressure
*memcg_to_vmpressure(struct mem_cgroup
*memcg
)
252 memcg
= root_mem_cgroup
;
253 return &memcg
->vmpressure
;
256 struct cgroup_subsys_state
*vmpressure_to_css(struct vmpressure
*vmpr
)
258 return &container_of(vmpr
, struct mem_cgroup
, vmpressure
)->css
;
261 static inline bool mem_cgroup_is_root(struct mem_cgroup
*memcg
)
263 return (memcg
== root_mem_cgroup
);
267 * We restrict the id in the range of [1, 65535], so it can fit into
270 #define MEM_CGROUP_ID_MAX USHRT_MAX
272 static inline unsigned short mem_cgroup_id(struct mem_cgroup
*memcg
)
274 return memcg
->css
.id
;
278 * A helper function to get mem_cgroup from ID. must be called under
279 * rcu_read_lock(). The caller is responsible for calling
280 * css_tryget_online() if the mem_cgroup is used for charging. (dropping
281 * refcnt from swap can be called against removed memcg.)
283 static inline struct mem_cgroup
*mem_cgroup_from_id(unsigned short id
)
285 struct cgroup_subsys_state
*css
;
287 css
= css_from_id(id
, &memory_cgrp_subsys
);
288 return mem_cgroup_from_css(css
);
291 /* Writing them here to avoid exposing memcg's inner layout */
292 #if defined(CONFIG_INET) && defined(CONFIG_MEMCG_KMEM)
294 void sock_update_memcg(struct sock
*sk
)
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
&& cg_proto
->active
&&
319 css_tryget_online(&memcg
->css
)) {
320 sk
->sk_cgrp
= cg_proto
;
324 EXPORT_SYMBOL(sock_update_memcg
);
326 void sock_release_memcg(struct sock
*sk
)
328 WARN_ON(!sk
->sk_cgrp
->memcg
);
329 css_put(&sk
->sk_cgrp
->memcg
->css
);
332 struct cg_proto
*tcp_proto_cgroup(struct mem_cgroup
*memcg
)
334 if (!memcg
|| mem_cgroup_is_root(memcg
))
337 return &memcg
->tcp_mem
;
339 EXPORT_SYMBOL(tcp_proto_cgroup
);
342 * mem_cgroup_charge_skmem - charge socket memory
343 * @proto: proto to charge
344 * @nr_pages: number of pages to charge
346 * Charges @nr_pages to @proto. Returns %true if the charge fit within
347 * @proto's configured limit, %false if the charge had to be forced.
349 bool mem_cgroup_charge_skmem(struct cg_proto
*proto
, unsigned int nr_pages
)
351 struct page_counter
*counter
;
353 if (page_counter_try_charge(&proto
->memory_allocated
,
354 nr_pages
, &counter
)) {
355 proto
->memory_pressure
= 0;
358 page_counter_charge(&proto
->memory_allocated
, nr_pages
);
359 proto
->memory_pressure
= 1;
364 * mem_cgroup_uncharge_skmem - uncharge socket memory
365 * @proto - proto to uncharge
366 * @nr_pages - number of pages to uncharge
368 void mem_cgroup_uncharge_skmem(struct cg_proto
*proto
, unsigned int nr_pages
)
370 page_counter_uncharge(&proto
->memory_allocated
, nr_pages
);
375 #ifdef CONFIG_MEMCG_KMEM
377 * This will be the memcg's index in each cache's ->memcg_params.memcg_caches.
378 * The main reason for not using cgroup id for this:
379 * this works better in sparse environments, where we have a lot of memcgs,
380 * but only a few kmem-limited. Or also, if we have, for instance, 200
381 * memcgs, and none but the 200th is kmem-limited, we'd have to have a
382 * 200 entry array for that.
384 * The current size of the caches array is stored in memcg_nr_cache_ids. It
385 * will double each time we have to increase it.
387 static DEFINE_IDA(memcg_cache_ida
);
388 int memcg_nr_cache_ids
;
390 /* Protects memcg_nr_cache_ids */
391 static DECLARE_RWSEM(memcg_cache_ids_sem
);
393 void memcg_get_cache_ids(void)
395 down_read(&memcg_cache_ids_sem
);
398 void memcg_put_cache_ids(void)
400 up_read(&memcg_cache_ids_sem
);
404 * MIN_SIZE is different than 1, because we would like to avoid going through
405 * the alloc/free process all the time. In a small machine, 4 kmem-limited
406 * cgroups is a reasonable guess. In the future, it could be a parameter or
407 * tunable, but that is strictly not necessary.
409 * MAX_SIZE should be as large as the number of cgrp_ids. Ideally, we could get
410 * this constant directly from cgroup, but it is understandable that this is
411 * better kept as an internal representation in cgroup.c. In any case, the
412 * cgrp_id space is not getting any smaller, and we don't have to necessarily
413 * increase ours as well if it increases.
415 #define MEMCG_CACHES_MIN_SIZE 4
416 #define MEMCG_CACHES_MAX_SIZE MEM_CGROUP_ID_MAX
419 * A lot of the calls to the cache allocation functions are expected to be
420 * inlined by the compiler. Since the calls to memcg_kmem_get_cache are
421 * conditional to this static branch, we'll have to allow modules that does
422 * kmem_cache_alloc and the such to see this symbol as well
424 struct static_key memcg_kmem_enabled_key
;
425 EXPORT_SYMBOL(memcg_kmem_enabled_key
);
427 #endif /* CONFIG_MEMCG_KMEM */
429 static struct mem_cgroup_per_zone
*
430 mem_cgroup_zone_zoneinfo(struct mem_cgroup
*memcg
, struct zone
*zone
)
432 int nid
= zone_to_nid(zone
);
433 int zid
= zone_idx(zone
);
435 return &memcg
->nodeinfo
[nid
]->zoneinfo
[zid
];
439 * mem_cgroup_css_from_page - css of the memcg associated with a page
440 * @page: page of interest
442 * If memcg is bound to the default hierarchy, css of the memcg associated
443 * with @page is returned. The returned css remains associated with @page
444 * until it is released.
446 * If memcg is bound to a traditional hierarchy, the css of root_mem_cgroup
449 * XXX: The above description of behavior on the default hierarchy isn't
450 * strictly true yet as replace_page_cache_page() can modify the
451 * association before @page is released even on the default hierarchy;
452 * however, the current and planned usages don't mix the the two functions
453 * and replace_page_cache_page() will soon be updated to make the invariant
456 struct cgroup_subsys_state
*mem_cgroup_css_from_page(struct page
*page
)
458 struct mem_cgroup
*memcg
;
462 memcg
= page
->mem_cgroup
;
464 if (!memcg
|| !cgroup_subsys_on_dfl(memory_cgrp_subsys
))
465 memcg
= root_mem_cgroup
;
472 * page_cgroup_ino - return inode number of the memcg a page is charged to
475 * Look up the closest online ancestor of the memory cgroup @page is charged to
476 * and return its inode number or 0 if @page is not charged to any cgroup. It
477 * is safe to call this function without holding a reference to @page.
479 * Note, this function is inherently racy, because there is nothing to prevent
480 * the cgroup inode from getting torn down and potentially reallocated a moment
481 * after page_cgroup_ino() returns, so it only should be used by callers that
482 * do not care (such as procfs interfaces).
484 ino_t
page_cgroup_ino(struct page
*page
)
486 struct mem_cgroup
*memcg
;
487 unsigned long ino
= 0;
490 memcg
= READ_ONCE(page
->mem_cgroup
);
491 while (memcg
&& !(memcg
->css
.flags
& CSS_ONLINE
))
492 memcg
= parent_mem_cgroup(memcg
);
494 ino
= cgroup_ino(memcg
->css
.cgroup
);
499 static struct mem_cgroup_per_zone
*
500 mem_cgroup_page_zoneinfo(struct mem_cgroup
*memcg
, struct page
*page
)
502 int nid
= page_to_nid(page
);
503 int zid
= page_zonenum(page
);
505 return &memcg
->nodeinfo
[nid
]->zoneinfo
[zid
];
508 static struct mem_cgroup_tree_per_zone
*
509 soft_limit_tree_node_zone(int nid
, int zid
)
511 return &soft_limit_tree
.rb_tree_per_node
[nid
]->rb_tree_per_zone
[zid
];
514 static struct mem_cgroup_tree_per_zone
*
515 soft_limit_tree_from_page(struct page
*page
)
517 int nid
= page_to_nid(page
);
518 int zid
= page_zonenum(page
);
520 return &soft_limit_tree
.rb_tree_per_node
[nid
]->rb_tree_per_zone
[zid
];
523 static void __mem_cgroup_insert_exceeded(struct mem_cgroup_per_zone
*mz
,
524 struct mem_cgroup_tree_per_zone
*mctz
,
525 unsigned long new_usage_in_excess
)
527 struct rb_node
**p
= &mctz
->rb_root
.rb_node
;
528 struct rb_node
*parent
= NULL
;
529 struct mem_cgroup_per_zone
*mz_node
;
534 mz
->usage_in_excess
= new_usage_in_excess
;
535 if (!mz
->usage_in_excess
)
539 mz_node
= rb_entry(parent
, struct mem_cgroup_per_zone
,
541 if (mz
->usage_in_excess
< mz_node
->usage_in_excess
)
544 * We can't avoid mem cgroups that are over their soft
545 * limit by the same amount
547 else if (mz
->usage_in_excess
>= mz_node
->usage_in_excess
)
550 rb_link_node(&mz
->tree_node
, parent
, p
);
551 rb_insert_color(&mz
->tree_node
, &mctz
->rb_root
);
555 static void __mem_cgroup_remove_exceeded(struct mem_cgroup_per_zone
*mz
,
556 struct mem_cgroup_tree_per_zone
*mctz
)
560 rb_erase(&mz
->tree_node
, &mctz
->rb_root
);
564 static void mem_cgroup_remove_exceeded(struct mem_cgroup_per_zone
*mz
,
565 struct mem_cgroup_tree_per_zone
*mctz
)
569 spin_lock_irqsave(&mctz
->lock
, flags
);
570 __mem_cgroup_remove_exceeded(mz
, mctz
);
571 spin_unlock_irqrestore(&mctz
->lock
, flags
);
574 static unsigned long soft_limit_excess(struct mem_cgroup
*memcg
)
576 unsigned long nr_pages
= page_counter_read(&memcg
->memory
);
577 unsigned long soft_limit
= READ_ONCE(memcg
->soft_limit
);
578 unsigned long excess
= 0;
580 if (nr_pages
> soft_limit
)
581 excess
= nr_pages
- soft_limit
;
586 static void mem_cgroup_update_tree(struct mem_cgroup
*memcg
, struct page
*page
)
588 unsigned long excess
;
589 struct mem_cgroup_per_zone
*mz
;
590 struct mem_cgroup_tree_per_zone
*mctz
;
592 mctz
= soft_limit_tree_from_page(page
);
594 * Necessary to update all ancestors when hierarchy is used.
595 * because their event counter is not touched.
597 for (; memcg
; memcg
= parent_mem_cgroup(memcg
)) {
598 mz
= mem_cgroup_page_zoneinfo(memcg
, page
);
599 excess
= soft_limit_excess(memcg
);
601 * We have to update the tree if mz is on RB-tree or
602 * mem is over its softlimit.
604 if (excess
|| mz
->on_tree
) {
607 spin_lock_irqsave(&mctz
->lock
, flags
);
608 /* if on-tree, remove it */
610 __mem_cgroup_remove_exceeded(mz
, mctz
);
612 * Insert again. mz->usage_in_excess will be updated.
613 * If excess is 0, no tree ops.
615 __mem_cgroup_insert_exceeded(mz
, mctz
, excess
);
616 spin_unlock_irqrestore(&mctz
->lock
, flags
);
621 static void mem_cgroup_remove_from_trees(struct mem_cgroup
*memcg
)
623 struct mem_cgroup_tree_per_zone
*mctz
;
624 struct mem_cgroup_per_zone
*mz
;
628 for (zid
= 0; zid
< MAX_NR_ZONES
; zid
++) {
629 mz
= &memcg
->nodeinfo
[nid
]->zoneinfo
[zid
];
630 mctz
= soft_limit_tree_node_zone(nid
, zid
);
631 mem_cgroup_remove_exceeded(mz
, mctz
);
636 static struct mem_cgroup_per_zone
*
637 __mem_cgroup_largest_soft_limit_node(struct mem_cgroup_tree_per_zone
*mctz
)
639 struct rb_node
*rightmost
= NULL
;
640 struct mem_cgroup_per_zone
*mz
;
644 rightmost
= rb_last(&mctz
->rb_root
);
646 goto done
; /* Nothing to reclaim from */
648 mz
= rb_entry(rightmost
, struct mem_cgroup_per_zone
, tree_node
);
650 * Remove the node now but someone else can add it back,
651 * we will to add it back at the end of reclaim to its correct
652 * position in the tree.
654 __mem_cgroup_remove_exceeded(mz
, mctz
);
655 if (!soft_limit_excess(mz
->memcg
) ||
656 !css_tryget_online(&mz
->memcg
->css
))
662 static struct mem_cgroup_per_zone
*
663 mem_cgroup_largest_soft_limit_node(struct mem_cgroup_tree_per_zone
*mctz
)
665 struct mem_cgroup_per_zone
*mz
;
667 spin_lock_irq(&mctz
->lock
);
668 mz
= __mem_cgroup_largest_soft_limit_node(mctz
);
669 spin_unlock_irq(&mctz
->lock
);
674 * Return page count for single (non recursive) @memcg.
676 * Implementation Note: reading percpu statistics for memcg.
678 * Both of vmstat[] and percpu_counter has threshold and do periodic
679 * synchronization to implement "quick" read. There are trade-off between
680 * reading cost and precision of value. Then, we may have a chance to implement
681 * a periodic synchronization of counter in memcg's counter.
683 * But this _read() function is used for user interface now. The user accounts
684 * memory usage by memory cgroup and he _always_ requires exact value because
685 * he accounts memory. Even if we provide quick-and-fuzzy read, we always
686 * have to visit all online cpus and make sum. So, for now, unnecessary
687 * synchronization is not implemented. (just implemented for cpu hotplug)
689 * If there are kernel internal actions which can make use of some not-exact
690 * value, and reading all cpu value can be performance bottleneck in some
691 * common workload, threshold and synchronization as vmstat[] should be
695 mem_cgroup_read_stat(struct mem_cgroup
*memcg
, enum mem_cgroup_stat_index idx
)
700 /* Per-cpu values can be negative, use a signed accumulator */
701 for_each_possible_cpu(cpu
)
702 val
+= per_cpu(memcg
->stat
->count
[idx
], cpu
);
704 * Summing races with updates, so val may be negative. Avoid exposing
705 * transient negative values.
712 static unsigned long mem_cgroup_read_events(struct mem_cgroup
*memcg
,
713 enum mem_cgroup_events_index idx
)
715 unsigned long val
= 0;
718 for_each_possible_cpu(cpu
)
719 val
+= per_cpu(memcg
->stat
->events
[idx
], cpu
);
723 static void mem_cgroup_charge_statistics(struct mem_cgroup
*memcg
,
728 * Here, RSS means 'mapped anon' and anon's SwapCache. Shmem/tmpfs is
729 * counted as CACHE even if it's on ANON LRU.
732 __this_cpu_add(memcg
->stat
->count
[MEM_CGROUP_STAT_RSS
],
735 __this_cpu_add(memcg
->stat
->count
[MEM_CGROUP_STAT_CACHE
],
738 if (PageTransHuge(page
))
739 __this_cpu_add(memcg
->stat
->count
[MEM_CGROUP_STAT_RSS_HUGE
],
742 /* pagein of a big page is an event. So, ignore page size */
744 __this_cpu_inc(memcg
->stat
->events
[MEM_CGROUP_EVENTS_PGPGIN
]);
746 __this_cpu_inc(memcg
->stat
->events
[MEM_CGROUP_EVENTS_PGPGOUT
]);
747 nr_pages
= -nr_pages
; /* for event */
750 __this_cpu_add(memcg
->stat
->nr_page_events
, nr_pages
);
753 static unsigned long mem_cgroup_node_nr_lru_pages(struct mem_cgroup
*memcg
,
755 unsigned int lru_mask
)
757 unsigned long nr
= 0;
760 VM_BUG_ON((unsigned)nid
>= nr_node_ids
);
762 for (zid
= 0; zid
< MAX_NR_ZONES
; zid
++) {
763 struct mem_cgroup_per_zone
*mz
;
767 if (!(BIT(lru
) & lru_mask
))
769 mz
= &memcg
->nodeinfo
[nid
]->zoneinfo
[zid
];
770 nr
+= mz
->lru_size
[lru
];
776 static unsigned long mem_cgroup_nr_lru_pages(struct mem_cgroup
*memcg
,
777 unsigned int lru_mask
)
779 unsigned long nr
= 0;
782 for_each_node_state(nid
, N_MEMORY
)
783 nr
+= mem_cgroup_node_nr_lru_pages(memcg
, nid
, lru_mask
);
787 static bool mem_cgroup_event_ratelimit(struct mem_cgroup
*memcg
,
788 enum mem_cgroup_events_target target
)
790 unsigned long val
, next
;
792 val
= __this_cpu_read(memcg
->stat
->nr_page_events
);
793 next
= __this_cpu_read(memcg
->stat
->targets
[target
]);
794 /* from time_after() in jiffies.h */
795 if ((long)next
- (long)val
< 0) {
797 case MEM_CGROUP_TARGET_THRESH
:
798 next
= val
+ THRESHOLDS_EVENTS_TARGET
;
800 case MEM_CGROUP_TARGET_SOFTLIMIT
:
801 next
= val
+ SOFTLIMIT_EVENTS_TARGET
;
803 case MEM_CGROUP_TARGET_NUMAINFO
:
804 next
= val
+ NUMAINFO_EVENTS_TARGET
;
809 __this_cpu_write(memcg
->stat
->targets
[target
], next
);
816 * Check events in order.
819 static void memcg_check_events(struct mem_cgroup
*memcg
, struct page
*page
)
821 /* threshold event is triggered in finer grain than soft limit */
822 if (unlikely(mem_cgroup_event_ratelimit(memcg
,
823 MEM_CGROUP_TARGET_THRESH
))) {
825 bool do_numainfo __maybe_unused
;
827 do_softlimit
= mem_cgroup_event_ratelimit(memcg
,
828 MEM_CGROUP_TARGET_SOFTLIMIT
);
830 do_numainfo
= mem_cgroup_event_ratelimit(memcg
,
831 MEM_CGROUP_TARGET_NUMAINFO
);
833 mem_cgroup_threshold(memcg
);
834 if (unlikely(do_softlimit
))
835 mem_cgroup_update_tree(memcg
, page
);
837 if (unlikely(do_numainfo
))
838 atomic_inc(&memcg
->numainfo_events
);
843 struct mem_cgroup
*mem_cgroup_from_task(struct task_struct
*p
)
846 * mm_update_next_owner() may clear mm->owner to NULL
847 * if it races with swapoff, page migration, etc.
848 * So this can be called with p == NULL.
853 return mem_cgroup_from_css(task_css(p
, memory_cgrp_id
));
855 EXPORT_SYMBOL(mem_cgroup_from_task
);
857 static struct mem_cgroup
*get_mem_cgroup_from_mm(struct mm_struct
*mm
)
859 struct mem_cgroup
*memcg
= NULL
;
864 * Page cache insertions can happen withou an
865 * actual mm context, e.g. during disk probing
866 * on boot, loopback IO, acct() writes etc.
869 memcg
= root_mem_cgroup
;
871 memcg
= mem_cgroup_from_task(rcu_dereference(mm
->owner
));
872 if (unlikely(!memcg
))
873 memcg
= root_mem_cgroup
;
875 } while (!css_tryget_online(&memcg
->css
));
881 * mem_cgroup_iter - iterate over memory cgroup hierarchy
882 * @root: hierarchy root
883 * @prev: previously returned memcg, NULL on first invocation
884 * @reclaim: cookie for shared reclaim walks, NULL for full walks
886 * Returns references to children of the hierarchy below @root, or
887 * @root itself, or %NULL after a full round-trip.
889 * Caller must pass the return value in @prev on subsequent
890 * invocations for reference counting, or use mem_cgroup_iter_break()
891 * to cancel a hierarchy walk before the round-trip is complete.
893 * Reclaimers can specify a zone and a priority level in @reclaim to
894 * divide up the memcgs in the hierarchy among all concurrent
895 * reclaimers operating on the same zone and priority.
897 struct mem_cgroup
*mem_cgroup_iter(struct mem_cgroup
*root
,
898 struct mem_cgroup
*prev
,
899 struct mem_cgroup_reclaim_cookie
*reclaim
)
901 struct mem_cgroup_reclaim_iter
*uninitialized_var(iter
);
902 struct cgroup_subsys_state
*css
= NULL
;
903 struct mem_cgroup
*memcg
= NULL
;
904 struct mem_cgroup
*pos
= NULL
;
906 if (mem_cgroup_disabled())
910 root
= root_mem_cgroup
;
912 if (prev
&& !reclaim
)
915 if (!root
->use_hierarchy
&& root
!= root_mem_cgroup
) {
924 struct mem_cgroup_per_zone
*mz
;
926 mz
= mem_cgroup_zone_zoneinfo(root
, reclaim
->zone
);
927 iter
= &mz
->iter
[reclaim
->priority
];
929 if (prev
&& reclaim
->generation
!= iter
->generation
)
933 pos
= READ_ONCE(iter
->position
);
934 if (!pos
|| css_tryget(&pos
->css
))
937 * css reference reached zero, so iter->position will
938 * be cleared by ->css_released. However, we should not
939 * rely on this happening soon, because ->css_released
940 * is called from a work queue, and by busy-waiting we
941 * might block it. So we clear iter->position right
944 (void)cmpxchg(&iter
->position
, pos
, NULL
);
952 css
= css_next_descendant_pre(css
, &root
->css
);
955 * Reclaimers share the hierarchy walk, and a
956 * new one might jump in right at the end of
957 * the hierarchy - make sure they see at least
958 * one group and restart from the beginning.
966 * Verify the css and acquire a reference. The root
967 * is provided by the caller, so we know it's alive
968 * and kicking, and don't take an extra reference.
970 memcg
= mem_cgroup_from_css(css
);
972 if (css
== &root
->css
)
975 if (css_tryget(css
)) {
977 * Make sure the memcg is initialized:
978 * mem_cgroup_css_online() orders the the
979 * initialization against setting the flag.
981 if (smp_load_acquire(&memcg
->initialized
))
992 * The position could have already been updated by a competing
993 * thread, so check that the value hasn't changed since we read
994 * it to avoid reclaiming from the same cgroup twice.
996 (void)cmpxchg(&iter
->position
, pos
, memcg
);
1004 reclaim
->generation
= iter
->generation
;
1010 if (prev
&& prev
!= root
)
1011 css_put(&prev
->css
);
1017 * mem_cgroup_iter_break - abort a hierarchy walk prematurely
1018 * @root: hierarchy root
1019 * @prev: last visited hierarchy member as returned by mem_cgroup_iter()
1021 void mem_cgroup_iter_break(struct mem_cgroup
*root
,
1022 struct mem_cgroup
*prev
)
1025 root
= root_mem_cgroup
;
1026 if (prev
&& prev
!= root
)
1027 css_put(&prev
->css
);
1030 static void invalidate_reclaim_iterators(struct mem_cgroup
*dead_memcg
)
1032 struct mem_cgroup
*memcg
= dead_memcg
;
1033 struct mem_cgroup_reclaim_iter
*iter
;
1034 struct mem_cgroup_per_zone
*mz
;
1038 while ((memcg
= parent_mem_cgroup(memcg
))) {
1039 for_each_node(nid
) {
1040 for (zid
= 0; zid
< MAX_NR_ZONES
; zid
++) {
1041 mz
= &memcg
->nodeinfo
[nid
]->zoneinfo
[zid
];
1042 for (i
= 0; i
<= DEF_PRIORITY
; i
++) {
1043 iter
= &mz
->iter
[i
];
1044 cmpxchg(&iter
->position
,
1053 * Iteration constructs for visiting all cgroups (under a tree). If
1054 * loops are exited prematurely (break), mem_cgroup_iter_break() must
1055 * be used for reference counting.
1057 #define for_each_mem_cgroup_tree(iter, root) \
1058 for (iter = mem_cgroup_iter(root, NULL, NULL); \
1060 iter = mem_cgroup_iter(root, iter, NULL))
1062 #define for_each_mem_cgroup(iter) \
1063 for (iter = mem_cgroup_iter(NULL, NULL, NULL); \
1065 iter = mem_cgroup_iter(NULL, iter, NULL))
1068 * mem_cgroup_zone_lruvec - get the lru list vector for a zone and memcg
1069 * @zone: zone of the wanted lruvec
1070 * @memcg: memcg of the wanted lruvec
1072 * Returns the lru list vector holding pages for the given @zone and
1073 * @mem. This can be the global zone lruvec, if the memory controller
1076 struct lruvec
*mem_cgroup_zone_lruvec(struct zone
*zone
,
1077 struct mem_cgroup
*memcg
)
1079 struct mem_cgroup_per_zone
*mz
;
1080 struct lruvec
*lruvec
;
1082 if (mem_cgroup_disabled()) {
1083 lruvec
= &zone
->lruvec
;
1087 mz
= mem_cgroup_zone_zoneinfo(memcg
, zone
);
1088 lruvec
= &mz
->lruvec
;
1091 * Since a node can be onlined after the mem_cgroup was created,
1092 * we have to be prepared to initialize lruvec->zone here;
1093 * and if offlined then reonlined, we need to reinitialize it.
1095 if (unlikely(lruvec
->zone
!= zone
))
1096 lruvec
->zone
= zone
;
1101 * mem_cgroup_page_lruvec - return lruvec for isolating/putting an LRU page
1103 * @zone: zone of the page
1105 * This function is only safe when following the LRU page isolation
1106 * and putback protocol: the LRU lock must be held, and the page must
1107 * either be PageLRU() or the caller must have isolated/allocated it.
1109 struct lruvec
*mem_cgroup_page_lruvec(struct page
*page
, struct zone
*zone
)
1111 struct mem_cgroup_per_zone
*mz
;
1112 struct mem_cgroup
*memcg
;
1113 struct lruvec
*lruvec
;
1115 if (mem_cgroup_disabled()) {
1116 lruvec
= &zone
->lruvec
;
1120 memcg
= page
->mem_cgroup
;
1122 * Swapcache readahead pages are added to the LRU - and
1123 * possibly migrated - before they are charged.
1126 memcg
= root_mem_cgroup
;
1128 mz
= mem_cgroup_page_zoneinfo(memcg
, page
);
1129 lruvec
= &mz
->lruvec
;
1132 * Since a node can be onlined after the mem_cgroup was created,
1133 * we have to be prepared to initialize lruvec->zone here;
1134 * and if offlined then reonlined, we need to reinitialize it.
1136 if (unlikely(lruvec
->zone
!= zone
))
1137 lruvec
->zone
= zone
;
1142 * mem_cgroup_update_lru_size - account for adding or removing an lru page
1143 * @lruvec: mem_cgroup per zone lru vector
1144 * @lru: index of lru list the page is sitting on
1145 * @nr_pages: positive when adding or negative when removing
1147 * This function must be called when a page is added to or removed from an
1150 void mem_cgroup_update_lru_size(struct lruvec
*lruvec
, enum lru_list lru
,
1153 struct mem_cgroup_per_zone
*mz
;
1154 unsigned long *lru_size
;
1156 if (mem_cgroup_disabled())
1159 mz
= container_of(lruvec
, struct mem_cgroup_per_zone
, lruvec
);
1160 lru_size
= mz
->lru_size
+ lru
;
1161 *lru_size
+= nr_pages
;
1162 VM_BUG_ON((long)(*lru_size
) < 0);
1165 bool task_in_mem_cgroup(struct task_struct
*task
, struct mem_cgroup
*memcg
)
1167 struct mem_cgroup
*task_memcg
;
1168 struct task_struct
*p
;
1171 p
= find_lock_task_mm(task
);
1173 task_memcg
= get_mem_cgroup_from_mm(p
->mm
);
1177 * All threads may have already detached their mm's, but the oom
1178 * killer still needs to detect if they have already been oom
1179 * killed to prevent needlessly killing additional tasks.
1182 task_memcg
= mem_cgroup_from_task(task
);
1183 css_get(&task_memcg
->css
);
1186 ret
= mem_cgroup_is_descendant(task_memcg
, memcg
);
1187 css_put(&task_memcg
->css
);
1191 #define mem_cgroup_from_counter(counter, member) \
1192 container_of(counter, struct mem_cgroup, member)
1195 * mem_cgroup_margin - calculate chargeable space of a memory cgroup
1196 * @memcg: the memory cgroup
1198 * Returns the maximum amount of memory @mem can be charged with, in
1201 static unsigned long mem_cgroup_margin(struct mem_cgroup
*memcg
)
1203 unsigned long margin
= 0;
1204 unsigned long count
;
1205 unsigned long limit
;
1207 count
= page_counter_read(&memcg
->memory
);
1208 limit
= READ_ONCE(memcg
->memory
.limit
);
1210 margin
= limit
- count
;
1212 if (do_swap_account
) {
1213 count
= page_counter_read(&memcg
->memsw
);
1214 limit
= READ_ONCE(memcg
->memsw
.limit
);
1216 margin
= min(margin
, limit
- count
);
1223 * A routine for checking "mem" is under move_account() or not.
1225 * Checking a cgroup is mc.from or mc.to or under hierarchy of
1226 * moving cgroups. This is for waiting at high-memory pressure
1229 static bool mem_cgroup_under_move(struct mem_cgroup
*memcg
)
1231 struct mem_cgroup
*from
;
1232 struct mem_cgroup
*to
;
1235 * Unlike task_move routines, we access mc.to, mc.from not under
1236 * mutual exclusion by cgroup_mutex. Here, we take spinlock instead.
1238 spin_lock(&mc
.lock
);
1244 ret
= mem_cgroup_is_descendant(from
, memcg
) ||
1245 mem_cgroup_is_descendant(to
, memcg
);
1247 spin_unlock(&mc
.lock
);
1251 static bool mem_cgroup_wait_acct_move(struct mem_cgroup
*memcg
)
1253 if (mc
.moving_task
&& current
!= mc
.moving_task
) {
1254 if (mem_cgroup_under_move(memcg
)) {
1256 prepare_to_wait(&mc
.waitq
, &wait
, TASK_INTERRUPTIBLE
);
1257 /* moving charge context might have finished. */
1260 finish_wait(&mc
.waitq
, &wait
);
1267 #define K(x) ((x) << (PAGE_SHIFT-10))
1269 * mem_cgroup_print_oom_info: Print OOM information relevant to memory controller.
1270 * @memcg: The memory cgroup that went over limit
1271 * @p: Task that is going to be killed
1273 * NOTE: @memcg and @p's mem_cgroup can be different when hierarchy is
1276 void mem_cgroup_print_oom_info(struct mem_cgroup
*memcg
, struct task_struct
*p
)
1278 /* oom_info_lock ensures that parallel ooms do not interleave */
1279 static DEFINE_MUTEX(oom_info_lock
);
1280 struct mem_cgroup
*iter
;
1283 mutex_lock(&oom_info_lock
);
1287 pr_info("Task in ");
1288 pr_cont_cgroup_path(task_cgroup(p
, memory_cgrp_id
));
1289 pr_cont(" killed as a result of limit of ");
1291 pr_info("Memory limit reached of cgroup ");
1294 pr_cont_cgroup_path(memcg
->css
.cgroup
);
1299 pr_info("memory: usage %llukB, limit %llukB, failcnt %lu\n",
1300 K((u64
)page_counter_read(&memcg
->memory
)),
1301 K((u64
)memcg
->memory
.limit
), memcg
->memory
.failcnt
);
1302 pr_info("memory+swap: usage %llukB, limit %llukB, failcnt %lu\n",
1303 K((u64
)page_counter_read(&memcg
->memsw
)),
1304 K((u64
)memcg
->memsw
.limit
), memcg
->memsw
.failcnt
);
1305 pr_info("kmem: usage %llukB, limit %llukB, failcnt %lu\n",
1306 K((u64
)page_counter_read(&memcg
->kmem
)),
1307 K((u64
)memcg
->kmem
.limit
), memcg
->kmem
.failcnt
);
1309 for_each_mem_cgroup_tree(iter
, memcg
) {
1310 pr_info("Memory cgroup stats for ");
1311 pr_cont_cgroup_path(iter
->css
.cgroup
);
1314 for (i
= 0; i
< MEM_CGROUP_STAT_NSTATS
; i
++) {
1315 if (i
== MEM_CGROUP_STAT_SWAP
&& !do_swap_account
)
1317 pr_cont(" %s:%luKB", mem_cgroup_stat_names
[i
],
1318 K(mem_cgroup_read_stat(iter
, i
)));
1321 for (i
= 0; i
< NR_LRU_LISTS
; i
++)
1322 pr_cont(" %s:%luKB", mem_cgroup_lru_names
[i
],
1323 K(mem_cgroup_nr_lru_pages(iter
, BIT(i
))));
1327 mutex_unlock(&oom_info_lock
);
1331 * This function returns the number of memcg under hierarchy tree. Returns
1332 * 1(self count) if no children.
1334 static int mem_cgroup_count_children(struct mem_cgroup
*memcg
)
1337 struct mem_cgroup
*iter
;
1339 for_each_mem_cgroup_tree(iter
, memcg
)
1345 * Return the memory (and swap, if configured) limit for a memcg.
1347 static unsigned long mem_cgroup_get_limit(struct mem_cgroup
*memcg
)
1349 unsigned long limit
;
1351 limit
= memcg
->memory
.limit
;
1352 if (mem_cgroup_swappiness(memcg
)) {
1353 unsigned long memsw_limit
;
1355 memsw_limit
= memcg
->memsw
.limit
;
1356 limit
= min(limit
+ total_swap_pages
, memsw_limit
);
1361 static void mem_cgroup_out_of_memory(struct mem_cgroup
*memcg
, gfp_t gfp_mask
,
1364 struct oom_control oc
= {
1367 .gfp_mask
= gfp_mask
,
1370 struct mem_cgroup
*iter
;
1371 unsigned long chosen_points
= 0;
1372 unsigned long totalpages
;
1373 unsigned int points
= 0;
1374 struct task_struct
*chosen
= NULL
;
1376 mutex_lock(&oom_lock
);
1379 * If current has a pending SIGKILL or is exiting, then automatically
1380 * select it. The goal is to allow it to allocate so that it may
1381 * quickly exit and free its memory.
1383 if (fatal_signal_pending(current
) || task_will_free_mem(current
)) {
1384 mark_oom_victim(current
);
1388 check_panic_on_oom(&oc
, CONSTRAINT_MEMCG
, memcg
);
1389 totalpages
= mem_cgroup_get_limit(memcg
) ? : 1;
1390 for_each_mem_cgroup_tree(iter
, memcg
) {
1391 struct css_task_iter it
;
1392 struct task_struct
*task
;
1394 css_task_iter_start(&iter
->css
, &it
);
1395 while ((task
= css_task_iter_next(&it
))) {
1396 switch (oom_scan_process_thread(&oc
, task
, totalpages
)) {
1397 case OOM_SCAN_SELECT
:
1399 put_task_struct(chosen
);
1401 chosen_points
= ULONG_MAX
;
1402 get_task_struct(chosen
);
1404 case OOM_SCAN_CONTINUE
:
1406 case OOM_SCAN_ABORT
:
1407 css_task_iter_end(&it
);
1408 mem_cgroup_iter_break(memcg
, iter
);
1410 put_task_struct(chosen
);
1415 points
= oom_badness(task
, memcg
, NULL
, totalpages
);
1416 if (!points
|| points
< chosen_points
)
1418 /* Prefer thread group leaders for display purposes */
1419 if (points
== chosen_points
&&
1420 thread_group_leader(chosen
))
1424 put_task_struct(chosen
);
1426 chosen_points
= points
;
1427 get_task_struct(chosen
);
1429 css_task_iter_end(&it
);
1433 points
= chosen_points
* 1000 / totalpages
;
1434 oom_kill_process(&oc
, chosen
, points
, totalpages
, memcg
,
1435 "Memory cgroup out of memory");
1438 mutex_unlock(&oom_lock
);
1441 #if MAX_NUMNODES > 1
1444 * test_mem_cgroup_node_reclaimable
1445 * @memcg: the target memcg
1446 * @nid: the node ID to be checked.
1447 * @noswap : specify true here if the user wants flle only information.
1449 * This function returns whether the specified memcg contains any
1450 * reclaimable pages on a node. Returns true if there are any reclaimable
1451 * pages in the node.
1453 static bool test_mem_cgroup_node_reclaimable(struct mem_cgroup
*memcg
,
1454 int nid
, bool noswap
)
1456 if (mem_cgroup_node_nr_lru_pages(memcg
, nid
, LRU_ALL_FILE
))
1458 if (noswap
|| !total_swap_pages
)
1460 if (mem_cgroup_node_nr_lru_pages(memcg
, nid
, LRU_ALL_ANON
))
1467 * Always updating the nodemask is not very good - even if we have an empty
1468 * list or the wrong list here, we can start from some node and traverse all
1469 * nodes based on the zonelist. So update the list loosely once per 10 secs.
1472 static void mem_cgroup_may_update_nodemask(struct mem_cgroup
*memcg
)
1476 * numainfo_events > 0 means there was at least NUMAINFO_EVENTS_TARGET
1477 * pagein/pageout changes since the last update.
1479 if (!atomic_read(&memcg
->numainfo_events
))
1481 if (atomic_inc_return(&memcg
->numainfo_updating
) > 1)
1484 /* make a nodemask where this memcg uses memory from */
1485 memcg
->scan_nodes
= node_states
[N_MEMORY
];
1487 for_each_node_mask(nid
, node_states
[N_MEMORY
]) {
1489 if (!test_mem_cgroup_node_reclaimable(memcg
, nid
, false))
1490 node_clear(nid
, memcg
->scan_nodes
);
1493 atomic_set(&memcg
->numainfo_events
, 0);
1494 atomic_set(&memcg
->numainfo_updating
, 0);
1498 * Selecting a node where we start reclaim from. Because what we need is just
1499 * reducing usage counter, start from anywhere is O,K. Considering
1500 * memory reclaim from current node, there are pros. and cons.
1502 * Freeing memory from current node means freeing memory from a node which
1503 * we'll use or we've used. So, it may make LRU bad. And if several threads
1504 * hit limits, it will see a contention on a node. But freeing from remote
1505 * node means more costs for memory reclaim because of memory latency.
1507 * Now, we use round-robin. Better algorithm is welcomed.
1509 int mem_cgroup_select_victim_node(struct mem_cgroup
*memcg
)
1513 mem_cgroup_may_update_nodemask(memcg
);
1514 node
= memcg
->last_scanned_node
;
1516 node
= next_node(node
, memcg
->scan_nodes
);
1517 if (node
== MAX_NUMNODES
)
1518 node
= first_node(memcg
->scan_nodes
);
1520 * We call this when we hit limit, not when pages are added to LRU.
1521 * No LRU may hold pages because all pages are UNEVICTABLE or
1522 * memcg is too small and all pages are not on LRU. In that case,
1523 * we use curret node.
1525 if (unlikely(node
== MAX_NUMNODES
))
1526 node
= numa_node_id();
1528 memcg
->last_scanned_node
= node
;
1532 int mem_cgroup_select_victim_node(struct mem_cgroup
*memcg
)
1538 static int mem_cgroup_soft_reclaim(struct mem_cgroup
*root_memcg
,
1541 unsigned long *total_scanned
)
1543 struct mem_cgroup
*victim
= NULL
;
1546 unsigned long excess
;
1547 unsigned long nr_scanned
;
1548 struct mem_cgroup_reclaim_cookie reclaim
= {
1553 excess
= soft_limit_excess(root_memcg
);
1556 victim
= mem_cgroup_iter(root_memcg
, victim
, &reclaim
);
1561 * If we have not been able to reclaim
1562 * anything, it might because there are
1563 * no reclaimable pages under this hierarchy
1568 * We want to do more targeted reclaim.
1569 * excess >> 2 is not to excessive so as to
1570 * reclaim too much, nor too less that we keep
1571 * coming back to reclaim from this cgroup
1573 if (total
>= (excess
>> 2) ||
1574 (loop
> MEM_CGROUP_MAX_RECLAIM_LOOPS
))
1579 total
+= mem_cgroup_shrink_node_zone(victim
, gfp_mask
, false,
1581 *total_scanned
+= nr_scanned
;
1582 if (!soft_limit_excess(root_memcg
))
1585 mem_cgroup_iter_break(root_memcg
, victim
);
1589 #ifdef CONFIG_LOCKDEP
1590 static struct lockdep_map memcg_oom_lock_dep_map
= {
1591 .name
= "memcg_oom_lock",
1595 static DEFINE_SPINLOCK(memcg_oom_lock
);
1598 * Check OOM-Killer is already running under our hierarchy.
1599 * If someone is running, return false.
1601 static bool mem_cgroup_oom_trylock(struct mem_cgroup
*memcg
)
1603 struct mem_cgroup
*iter
, *failed
= NULL
;
1605 spin_lock(&memcg_oom_lock
);
1607 for_each_mem_cgroup_tree(iter
, memcg
) {
1608 if (iter
->oom_lock
) {
1610 * this subtree of our hierarchy is already locked
1611 * so we cannot give a lock.
1614 mem_cgroup_iter_break(memcg
, iter
);
1617 iter
->oom_lock
= true;
1622 * OK, we failed to lock the whole subtree so we have
1623 * to clean up what we set up to the failing subtree
1625 for_each_mem_cgroup_tree(iter
, memcg
) {
1626 if (iter
== failed
) {
1627 mem_cgroup_iter_break(memcg
, iter
);
1630 iter
->oom_lock
= false;
1633 mutex_acquire(&memcg_oom_lock_dep_map
, 0, 1, _RET_IP_
);
1635 spin_unlock(&memcg_oom_lock
);
1640 static void mem_cgroup_oom_unlock(struct mem_cgroup
*memcg
)
1642 struct mem_cgroup
*iter
;
1644 spin_lock(&memcg_oom_lock
);
1645 mutex_release(&memcg_oom_lock_dep_map
, 1, _RET_IP_
);
1646 for_each_mem_cgroup_tree(iter
, memcg
)
1647 iter
->oom_lock
= false;
1648 spin_unlock(&memcg_oom_lock
);
1651 static void mem_cgroup_mark_under_oom(struct mem_cgroup
*memcg
)
1653 struct mem_cgroup
*iter
;
1655 spin_lock(&memcg_oom_lock
);
1656 for_each_mem_cgroup_tree(iter
, memcg
)
1658 spin_unlock(&memcg_oom_lock
);
1661 static void mem_cgroup_unmark_under_oom(struct mem_cgroup
*memcg
)
1663 struct mem_cgroup
*iter
;
1666 * When a new child is created while the hierarchy is under oom,
1667 * mem_cgroup_oom_lock() may not be called. Watch for underflow.
1669 spin_lock(&memcg_oom_lock
);
1670 for_each_mem_cgroup_tree(iter
, memcg
)
1671 if (iter
->under_oom
> 0)
1673 spin_unlock(&memcg_oom_lock
);
1676 static DECLARE_WAIT_QUEUE_HEAD(memcg_oom_waitq
);
1678 struct oom_wait_info
{
1679 struct mem_cgroup
*memcg
;
1683 static int memcg_oom_wake_function(wait_queue_t
*wait
,
1684 unsigned mode
, int sync
, void *arg
)
1686 struct mem_cgroup
*wake_memcg
= (struct mem_cgroup
*)arg
;
1687 struct mem_cgroup
*oom_wait_memcg
;
1688 struct oom_wait_info
*oom_wait_info
;
1690 oom_wait_info
= container_of(wait
, struct oom_wait_info
, wait
);
1691 oom_wait_memcg
= oom_wait_info
->memcg
;
1693 if (!mem_cgroup_is_descendant(wake_memcg
, oom_wait_memcg
) &&
1694 !mem_cgroup_is_descendant(oom_wait_memcg
, wake_memcg
))
1696 return autoremove_wake_function(wait
, mode
, sync
, arg
);
1699 static void memcg_oom_recover(struct mem_cgroup
*memcg
)
1702 * For the following lockless ->under_oom test, the only required
1703 * guarantee is that it must see the state asserted by an OOM when
1704 * this function is called as a result of userland actions
1705 * triggered by the notification of the OOM. This is trivially
1706 * achieved by invoking mem_cgroup_mark_under_oom() before
1707 * triggering notification.
1709 if (memcg
&& memcg
->under_oom
)
1710 __wake_up(&memcg_oom_waitq
, TASK_NORMAL
, 0, memcg
);
1713 static void mem_cgroup_oom(struct mem_cgroup
*memcg
, gfp_t mask
, int order
)
1715 if (!current
->memcg_may_oom
)
1718 * We are in the middle of the charge context here, so we
1719 * don't want to block when potentially sitting on a callstack
1720 * that holds all kinds of filesystem and mm locks.
1722 * Also, the caller may handle a failed allocation gracefully
1723 * (like optional page cache readahead) and so an OOM killer
1724 * invocation might not even be necessary.
1726 * That's why we don't do anything here except remember the
1727 * OOM context and then deal with it at the end of the page
1728 * fault when the stack is unwound, the locks are released,
1729 * and when we know whether the fault was overall successful.
1731 css_get(&memcg
->css
);
1732 current
->memcg_in_oom
= memcg
;
1733 current
->memcg_oom_gfp_mask
= mask
;
1734 current
->memcg_oom_order
= order
;
1738 * mem_cgroup_oom_synchronize - complete memcg OOM handling
1739 * @handle: actually kill/wait or just clean up the OOM state
1741 * This has to be called at the end of a page fault if the memcg OOM
1742 * handler was enabled.
1744 * Memcg supports userspace OOM handling where failed allocations must
1745 * sleep on a waitqueue until the userspace task resolves the
1746 * situation. Sleeping directly in the charge context with all kinds
1747 * of locks held is not a good idea, instead we remember an OOM state
1748 * in the task and mem_cgroup_oom_synchronize() has to be called at
1749 * the end of the page fault to complete the OOM handling.
1751 * Returns %true if an ongoing memcg OOM situation was detected and
1752 * completed, %false otherwise.
1754 bool mem_cgroup_oom_synchronize(bool handle
)
1756 struct mem_cgroup
*memcg
= current
->memcg_in_oom
;
1757 struct oom_wait_info owait
;
1760 /* OOM is global, do not handle */
1764 if (!handle
|| oom_killer_disabled
)
1767 owait
.memcg
= memcg
;
1768 owait
.wait
.flags
= 0;
1769 owait
.wait
.func
= memcg_oom_wake_function
;
1770 owait
.wait
.private = current
;
1771 INIT_LIST_HEAD(&owait
.wait
.task_list
);
1773 prepare_to_wait(&memcg_oom_waitq
, &owait
.wait
, TASK_KILLABLE
);
1774 mem_cgroup_mark_under_oom(memcg
);
1776 locked
= mem_cgroup_oom_trylock(memcg
);
1779 mem_cgroup_oom_notify(memcg
);
1781 if (locked
&& !memcg
->oom_kill_disable
) {
1782 mem_cgroup_unmark_under_oom(memcg
);
1783 finish_wait(&memcg_oom_waitq
, &owait
.wait
);
1784 mem_cgroup_out_of_memory(memcg
, current
->memcg_oom_gfp_mask
,
1785 current
->memcg_oom_order
);
1788 mem_cgroup_unmark_under_oom(memcg
);
1789 finish_wait(&memcg_oom_waitq
, &owait
.wait
);
1793 mem_cgroup_oom_unlock(memcg
);
1795 * There is no guarantee that an OOM-lock contender
1796 * sees the wakeups triggered by the OOM kill
1797 * uncharges. Wake any sleepers explicitely.
1799 memcg_oom_recover(memcg
);
1802 current
->memcg_in_oom
= NULL
;
1803 css_put(&memcg
->css
);
1808 * mem_cgroup_begin_page_stat - begin a page state statistics transaction
1809 * @page: page that is going to change accounted state
1811 * This function must mark the beginning of an accounted page state
1812 * change to prevent double accounting when the page is concurrently
1813 * being moved to another memcg:
1815 * memcg = mem_cgroup_begin_page_stat(page);
1816 * if (TestClearPageState(page))
1817 * mem_cgroup_update_page_stat(memcg, state, -1);
1818 * mem_cgroup_end_page_stat(memcg);
1820 struct mem_cgroup
*mem_cgroup_begin_page_stat(struct page
*page
)
1822 struct mem_cgroup
*memcg
;
1823 unsigned long flags
;
1826 * The RCU lock is held throughout the transaction. The fast
1827 * path can get away without acquiring the memcg->move_lock
1828 * because page moving starts with an RCU grace period.
1830 * The RCU lock also protects the memcg from being freed when
1831 * the page state that is going to change is the only thing
1832 * preventing the page from being uncharged.
1833 * E.g. end-writeback clearing PageWriteback(), which allows
1834 * migration to go ahead and uncharge the page before the
1835 * account transaction might be complete.
1839 if (mem_cgroup_disabled())
1842 memcg
= page
->mem_cgroup
;
1843 if (unlikely(!memcg
))
1846 if (atomic_read(&memcg
->moving_account
) <= 0)
1849 spin_lock_irqsave(&memcg
->move_lock
, flags
);
1850 if (memcg
!= page
->mem_cgroup
) {
1851 spin_unlock_irqrestore(&memcg
->move_lock
, flags
);
1856 * When charge migration first begins, we can have locked and
1857 * unlocked page stat updates happening concurrently. Track
1858 * the task who has the lock for mem_cgroup_end_page_stat().
1860 memcg
->move_lock_task
= current
;
1861 memcg
->move_lock_flags
= flags
;
1865 EXPORT_SYMBOL(mem_cgroup_begin_page_stat
);
1868 * mem_cgroup_end_page_stat - finish a page state statistics transaction
1869 * @memcg: the memcg that was accounted against
1871 void mem_cgroup_end_page_stat(struct mem_cgroup
*memcg
)
1873 if (memcg
&& memcg
->move_lock_task
== current
) {
1874 unsigned long flags
= memcg
->move_lock_flags
;
1876 memcg
->move_lock_task
= NULL
;
1877 memcg
->move_lock_flags
= 0;
1879 spin_unlock_irqrestore(&memcg
->move_lock
, flags
);
1884 EXPORT_SYMBOL(mem_cgroup_end_page_stat
);
1887 * size of first charge trial. "32" comes from vmscan.c's magic value.
1888 * TODO: maybe necessary to use big numbers in big irons.
1890 #define CHARGE_BATCH 32U
1891 struct memcg_stock_pcp
{
1892 struct mem_cgroup
*cached
; /* this never be root cgroup */
1893 unsigned int nr_pages
;
1894 struct work_struct work
;
1895 unsigned long flags
;
1896 #define FLUSHING_CACHED_CHARGE 0
1898 static DEFINE_PER_CPU(struct memcg_stock_pcp
, memcg_stock
);
1899 static DEFINE_MUTEX(percpu_charge_mutex
);
1902 * consume_stock: Try to consume stocked charge on this cpu.
1903 * @memcg: memcg to consume from.
1904 * @nr_pages: how many pages to charge.
1906 * The charges will only happen if @memcg matches the current cpu's memcg
1907 * stock, and at least @nr_pages are available in that stock. Failure to
1908 * service an allocation will refill the stock.
1910 * returns true if successful, false otherwise.
1912 static bool consume_stock(struct mem_cgroup
*memcg
, unsigned int nr_pages
)
1914 struct memcg_stock_pcp
*stock
;
1917 if (nr_pages
> CHARGE_BATCH
)
1920 stock
= &get_cpu_var(memcg_stock
);
1921 if (memcg
== stock
->cached
&& stock
->nr_pages
>= nr_pages
) {
1922 stock
->nr_pages
-= nr_pages
;
1925 put_cpu_var(memcg_stock
);
1930 * Returns stocks cached in percpu and reset cached information.
1932 static void drain_stock(struct memcg_stock_pcp
*stock
)
1934 struct mem_cgroup
*old
= stock
->cached
;
1936 if (stock
->nr_pages
) {
1937 page_counter_uncharge(&old
->memory
, stock
->nr_pages
);
1938 if (do_swap_account
)
1939 page_counter_uncharge(&old
->memsw
, stock
->nr_pages
);
1940 css_put_many(&old
->css
, stock
->nr_pages
);
1941 stock
->nr_pages
= 0;
1943 stock
->cached
= NULL
;
1947 * This must be called under preempt disabled or must be called by
1948 * a thread which is pinned to local cpu.
1950 static void drain_local_stock(struct work_struct
*dummy
)
1952 struct memcg_stock_pcp
*stock
= this_cpu_ptr(&memcg_stock
);
1954 clear_bit(FLUSHING_CACHED_CHARGE
, &stock
->flags
);
1958 * Cache charges(val) to local per_cpu area.
1959 * This will be consumed by consume_stock() function, later.
1961 static void refill_stock(struct mem_cgroup
*memcg
, unsigned int nr_pages
)
1963 struct memcg_stock_pcp
*stock
= &get_cpu_var(memcg_stock
);
1965 if (stock
->cached
!= memcg
) { /* reset if necessary */
1967 stock
->cached
= memcg
;
1969 stock
->nr_pages
+= nr_pages
;
1970 put_cpu_var(memcg_stock
);
1974 * Drains all per-CPU charge caches for given root_memcg resp. subtree
1975 * of the hierarchy under it.
1977 static void drain_all_stock(struct mem_cgroup
*root_memcg
)
1981 /* If someone's already draining, avoid adding running more workers. */
1982 if (!mutex_trylock(&percpu_charge_mutex
))
1984 /* Notify other cpus that system-wide "drain" is running */
1987 for_each_online_cpu(cpu
) {
1988 struct memcg_stock_pcp
*stock
= &per_cpu(memcg_stock
, cpu
);
1989 struct mem_cgroup
*memcg
;
1991 memcg
= stock
->cached
;
1992 if (!memcg
|| !stock
->nr_pages
)
1994 if (!mem_cgroup_is_descendant(memcg
, root_memcg
))
1996 if (!test_and_set_bit(FLUSHING_CACHED_CHARGE
, &stock
->flags
)) {
1998 drain_local_stock(&stock
->work
);
2000 schedule_work_on(cpu
, &stock
->work
);
2005 mutex_unlock(&percpu_charge_mutex
);
2008 static int memcg_cpu_hotplug_callback(struct notifier_block
*nb
,
2009 unsigned long action
,
2012 int cpu
= (unsigned long)hcpu
;
2013 struct memcg_stock_pcp
*stock
;
2015 if (action
== CPU_ONLINE
)
2018 if (action
!= CPU_DEAD
&& action
!= CPU_DEAD_FROZEN
)
2021 stock
= &per_cpu(memcg_stock
, cpu
);
2027 * Scheduled by try_charge() to be executed from the userland return path
2028 * and reclaims memory over the high limit.
2030 void mem_cgroup_handle_over_high(void)
2032 unsigned int nr_pages
= current
->memcg_nr_pages_over_high
;
2033 struct mem_cgroup
*memcg
, *pos
;
2035 if (likely(!nr_pages
))
2038 pos
= memcg
= get_mem_cgroup_from_mm(current
->mm
);
2041 if (page_counter_read(&pos
->memory
) <= pos
->high
)
2043 mem_cgroup_events(pos
, MEMCG_HIGH
, 1);
2044 try_to_free_mem_cgroup_pages(pos
, nr_pages
, GFP_KERNEL
, true);
2045 } while ((pos
= parent_mem_cgroup(pos
)));
2047 css_put(&memcg
->css
);
2048 current
->memcg_nr_pages_over_high
= 0;
2051 static int try_charge(struct mem_cgroup
*memcg
, gfp_t gfp_mask
,
2052 unsigned int nr_pages
)
2054 unsigned int batch
= max(CHARGE_BATCH
, nr_pages
);
2055 int nr_retries
= MEM_CGROUP_RECLAIM_RETRIES
;
2056 struct mem_cgroup
*mem_over_limit
;
2057 struct page_counter
*counter
;
2058 unsigned long nr_reclaimed
;
2059 bool may_swap
= true;
2060 bool drained
= false;
2062 if (mem_cgroup_is_root(memcg
))
2065 if (consume_stock(memcg
, nr_pages
))
2068 if (!do_swap_account
||
2069 page_counter_try_charge(&memcg
->memsw
, batch
, &counter
)) {
2070 if (page_counter_try_charge(&memcg
->memory
, batch
, &counter
))
2072 if (do_swap_account
)
2073 page_counter_uncharge(&memcg
->memsw
, batch
);
2074 mem_over_limit
= mem_cgroup_from_counter(counter
, memory
);
2076 mem_over_limit
= mem_cgroup_from_counter(counter
, memsw
);
2080 if (batch
> nr_pages
) {
2086 * Unlike in global OOM situations, memcg is not in a physical
2087 * memory shortage. Allow dying and OOM-killed tasks to
2088 * bypass the last charges so that they can exit quickly and
2089 * free their memory.
2091 if (unlikely(test_thread_flag(TIF_MEMDIE
) ||
2092 fatal_signal_pending(current
) ||
2093 current
->flags
& PF_EXITING
))
2096 if (unlikely(task_in_memcg_oom(current
)))
2099 if (!gfpflags_allow_blocking(gfp_mask
))
2102 mem_cgroup_events(mem_over_limit
, MEMCG_MAX
, 1);
2104 nr_reclaimed
= try_to_free_mem_cgroup_pages(mem_over_limit
, nr_pages
,
2105 gfp_mask
, may_swap
);
2107 if (mem_cgroup_margin(mem_over_limit
) >= nr_pages
)
2111 drain_all_stock(mem_over_limit
);
2116 if (gfp_mask
& __GFP_NORETRY
)
2119 * Even though the limit is exceeded at this point, reclaim
2120 * may have been able to free some pages. Retry the charge
2121 * before killing the task.
2123 * Only for regular pages, though: huge pages are rather
2124 * unlikely to succeed so close to the limit, and we fall back
2125 * to regular pages anyway in case of failure.
2127 if (nr_reclaimed
&& nr_pages
<= (1 << PAGE_ALLOC_COSTLY_ORDER
))
2130 * At task move, charge accounts can be doubly counted. So, it's
2131 * better to wait until the end of task_move if something is going on.
2133 if (mem_cgroup_wait_acct_move(mem_over_limit
))
2139 if (gfp_mask
& __GFP_NOFAIL
)
2142 if (fatal_signal_pending(current
))
2145 mem_cgroup_events(mem_over_limit
, MEMCG_OOM
, 1);
2147 mem_cgroup_oom(mem_over_limit
, gfp_mask
,
2148 get_order(nr_pages
* PAGE_SIZE
));
2150 if (!(gfp_mask
& __GFP_NOFAIL
))
2154 * The allocation either can't fail or will lead to more memory
2155 * being freed very soon. Allow memory usage go over the limit
2156 * temporarily by force charging it.
2158 page_counter_charge(&memcg
->memory
, nr_pages
);
2159 if (do_swap_account
)
2160 page_counter_charge(&memcg
->memsw
, nr_pages
);
2161 css_get_many(&memcg
->css
, nr_pages
);
2166 css_get_many(&memcg
->css
, batch
);
2167 if (batch
> nr_pages
)
2168 refill_stock(memcg
, batch
- nr_pages
);
2171 * If the hierarchy is above the normal consumption range, schedule
2172 * reclaim on returning to userland. We can perform reclaim here
2173 * if __GFP_RECLAIM but let's always punt for simplicity and so that
2174 * GFP_KERNEL can consistently be used during reclaim. @memcg is
2175 * not recorded as it most likely matches current's and won't
2176 * change in the meantime. As high limit is checked again before
2177 * reclaim, the cost of mismatch is negligible.
2180 if (page_counter_read(&memcg
->memory
) > memcg
->high
) {
2181 current
->memcg_nr_pages_over_high
+= batch
;
2182 set_notify_resume(current
);
2185 } while ((memcg
= parent_mem_cgroup(memcg
)));
2190 static void cancel_charge(struct mem_cgroup
*memcg
, unsigned int nr_pages
)
2192 if (mem_cgroup_is_root(memcg
))
2195 page_counter_uncharge(&memcg
->memory
, nr_pages
);
2196 if (do_swap_account
)
2197 page_counter_uncharge(&memcg
->memsw
, nr_pages
);
2199 css_put_many(&memcg
->css
, nr_pages
);
2202 static void lock_page_lru(struct page
*page
, int *isolated
)
2204 struct zone
*zone
= page_zone(page
);
2206 spin_lock_irq(&zone
->lru_lock
);
2207 if (PageLRU(page
)) {
2208 struct lruvec
*lruvec
;
2210 lruvec
= mem_cgroup_page_lruvec(page
, zone
);
2212 del_page_from_lru_list(page
, lruvec
, page_lru(page
));
2218 static void unlock_page_lru(struct page
*page
, int isolated
)
2220 struct zone
*zone
= page_zone(page
);
2223 struct lruvec
*lruvec
;
2225 lruvec
= mem_cgroup_page_lruvec(page
, zone
);
2226 VM_BUG_ON_PAGE(PageLRU(page
), page
);
2228 add_page_to_lru_list(page
, lruvec
, page_lru(page
));
2230 spin_unlock_irq(&zone
->lru_lock
);
2233 static void commit_charge(struct page
*page
, struct mem_cgroup
*memcg
,
2238 VM_BUG_ON_PAGE(page
->mem_cgroup
, page
);
2241 * In some cases, SwapCache and FUSE(splice_buf->radixtree), the page
2242 * may already be on some other mem_cgroup's LRU. Take care of it.
2245 lock_page_lru(page
, &isolated
);
2248 * Nobody should be changing or seriously looking at
2249 * page->mem_cgroup at this point:
2251 * - the page is uncharged
2253 * - the page is off-LRU
2255 * - an anonymous fault has exclusive page access, except for
2256 * a locked page table
2258 * - a page cache insertion, a swapin fault, or a migration
2259 * have the page locked
2261 page
->mem_cgroup
= memcg
;
2264 unlock_page_lru(page
, isolated
);
2267 #ifdef CONFIG_MEMCG_KMEM
2268 static int memcg_alloc_cache_id(void)
2273 id
= ida_simple_get(&memcg_cache_ida
,
2274 0, MEMCG_CACHES_MAX_SIZE
, GFP_KERNEL
);
2278 if (id
< memcg_nr_cache_ids
)
2282 * There's no space for the new id in memcg_caches arrays,
2283 * so we have to grow them.
2285 down_write(&memcg_cache_ids_sem
);
2287 size
= 2 * (id
+ 1);
2288 if (size
< MEMCG_CACHES_MIN_SIZE
)
2289 size
= MEMCG_CACHES_MIN_SIZE
;
2290 else if (size
> MEMCG_CACHES_MAX_SIZE
)
2291 size
= MEMCG_CACHES_MAX_SIZE
;
2293 err
= memcg_update_all_caches(size
);
2295 err
= memcg_update_all_list_lrus(size
);
2297 memcg_nr_cache_ids
= size
;
2299 up_write(&memcg_cache_ids_sem
);
2302 ida_simple_remove(&memcg_cache_ida
, id
);
2308 static void memcg_free_cache_id(int id
)
2310 ida_simple_remove(&memcg_cache_ida
, id
);
2313 struct memcg_kmem_cache_create_work
{
2314 struct mem_cgroup
*memcg
;
2315 struct kmem_cache
*cachep
;
2316 struct work_struct work
;
2319 static void memcg_kmem_cache_create_func(struct work_struct
*w
)
2321 struct memcg_kmem_cache_create_work
*cw
=
2322 container_of(w
, struct memcg_kmem_cache_create_work
, work
);
2323 struct mem_cgroup
*memcg
= cw
->memcg
;
2324 struct kmem_cache
*cachep
= cw
->cachep
;
2326 memcg_create_kmem_cache(memcg
, cachep
);
2328 css_put(&memcg
->css
);
2333 * Enqueue the creation of a per-memcg kmem_cache.
2335 static void __memcg_schedule_kmem_cache_create(struct mem_cgroup
*memcg
,
2336 struct kmem_cache
*cachep
)
2338 struct memcg_kmem_cache_create_work
*cw
;
2340 cw
= kmalloc(sizeof(*cw
), GFP_NOWAIT
);
2344 css_get(&memcg
->css
);
2347 cw
->cachep
= cachep
;
2348 INIT_WORK(&cw
->work
, memcg_kmem_cache_create_func
);
2350 schedule_work(&cw
->work
);
2353 static void memcg_schedule_kmem_cache_create(struct mem_cgroup
*memcg
,
2354 struct kmem_cache
*cachep
)
2357 * We need to stop accounting when we kmalloc, because if the
2358 * corresponding kmalloc cache is not yet created, the first allocation
2359 * in __memcg_schedule_kmem_cache_create will recurse.
2361 * However, it is better to enclose the whole function. Depending on
2362 * the debugging options enabled, INIT_WORK(), for instance, can
2363 * trigger an allocation. This too, will make us recurse. Because at
2364 * this point we can't allow ourselves back into memcg_kmem_get_cache,
2365 * the safest choice is to do it like this, wrapping the whole function.
2367 current
->memcg_kmem_skip_account
= 1;
2368 __memcg_schedule_kmem_cache_create(memcg
, cachep
);
2369 current
->memcg_kmem_skip_account
= 0;
2373 * Return the kmem_cache we're supposed to use for a slab allocation.
2374 * We try to use the current memcg's version of the cache.
2376 * If the cache does not exist yet, if we are the first user of it,
2377 * we either create it immediately, if possible, or create it asynchronously
2379 * In the latter case, we will let the current allocation go through with
2380 * the original cache.
2382 * Can't be called in interrupt context or from kernel threads.
2383 * This function needs to be called with rcu_read_lock() held.
2385 struct kmem_cache
*__memcg_kmem_get_cache(struct kmem_cache
*cachep
, gfp_t gfp
)
2387 struct mem_cgroup
*memcg
;
2388 struct kmem_cache
*memcg_cachep
;
2391 VM_BUG_ON(!is_root_cache(cachep
));
2393 if (cachep
->flags
& SLAB_ACCOUNT
)
2394 gfp
|= __GFP_ACCOUNT
;
2396 if (!(gfp
& __GFP_ACCOUNT
))
2399 if (current
->memcg_kmem_skip_account
)
2402 memcg
= get_mem_cgroup_from_mm(current
->mm
);
2403 kmemcg_id
= READ_ONCE(memcg
->kmemcg_id
);
2407 memcg_cachep
= cache_from_memcg_idx(cachep
, kmemcg_id
);
2408 if (likely(memcg_cachep
))
2409 return memcg_cachep
;
2412 * If we are in a safe context (can wait, and not in interrupt
2413 * context), we could be be predictable and return right away.
2414 * This would guarantee that the allocation being performed
2415 * already belongs in the new cache.
2417 * However, there are some clashes that can arrive from locking.
2418 * For instance, because we acquire the slab_mutex while doing
2419 * memcg_create_kmem_cache, this means no further allocation
2420 * could happen with the slab_mutex held. So it's better to
2423 memcg_schedule_kmem_cache_create(memcg
, cachep
);
2425 css_put(&memcg
->css
);
2429 void __memcg_kmem_put_cache(struct kmem_cache
*cachep
)
2431 if (!is_root_cache(cachep
))
2432 css_put(&cachep
->memcg_params
.memcg
->css
);
2435 int __memcg_kmem_charge_memcg(struct page
*page
, gfp_t gfp
, int order
,
2436 struct mem_cgroup
*memcg
)
2438 unsigned int nr_pages
= 1 << order
;
2439 struct page_counter
*counter
;
2442 if (!memcg_kmem_is_active(memcg
))
2445 if (!page_counter_try_charge(&memcg
->kmem
, nr_pages
, &counter
))
2448 ret
= try_charge(memcg
, gfp
, nr_pages
);
2450 page_counter_uncharge(&memcg
->kmem
, nr_pages
);
2454 page
->mem_cgroup
= memcg
;
2459 int __memcg_kmem_charge(struct page
*page
, gfp_t gfp
, int order
)
2461 struct mem_cgroup
*memcg
;
2464 memcg
= get_mem_cgroup_from_mm(current
->mm
);
2465 ret
= __memcg_kmem_charge_memcg(page
, gfp
, order
, memcg
);
2466 css_put(&memcg
->css
);
2470 void __memcg_kmem_uncharge(struct page
*page
, int order
)
2472 struct mem_cgroup
*memcg
= page
->mem_cgroup
;
2473 unsigned int nr_pages
= 1 << order
;
2478 VM_BUG_ON_PAGE(mem_cgroup_is_root(memcg
), page
);
2480 page_counter_uncharge(&memcg
->kmem
, nr_pages
);
2481 page_counter_uncharge(&memcg
->memory
, nr_pages
);
2482 if (do_swap_account
)
2483 page_counter_uncharge(&memcg
->memsw
, nr_pages
);
2485 page
->mem_cgroup
= NULL
;
2486 css_put_many(&memcg
->css
, nr_pages
);
2488 #endif /* CONFIG_MEMCG_KMEM */
2490 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
2493 * Because tail pages are not marked as "used", set it. We're under
2494 * zone->lru_lock, 'splitting on pmd' and compound_lock.
2495 * charge/uncharge will be never happen and move_account() is done under
2496 * compound_lock(), so we don't have to take care of races.
2498 void mem_cgroup_split_huge_fixup(struct page
*head
)
2502 if (mem_cgroup_disabled())
2505 for (i
= 1; i
< HPAGE_PMD_NR
; i
++)
2506 head
[i
].mem_cgroup
= head
->mem_cgroup
;
2508 __this_cpu_sub(head
->mem_cgroup
->stat
->count
[MEM_CGROUP_STAT_RSS_HUGE
],
2511 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
2513 #ifdef CONFIG_MEMCG_SWAP
2514 static void mem_cgroup_swap_statistics(struct mem_cgroup
*memcg
,
2517 int val
= (charge
) ? 1 : -1;
2518 this_cpu_add(memcg
->stat
->count
[MEM_CGROUP_STAT_SWAP
], val
);
2522 * mem_cgroup_move_swap_account - move swap charge and swap_cgroup's record.
2523 * @entry: swap entry to be moved
2524 * @from: mem_cgroup which the entry is moved from
2525 * @to: mem_cgroup which the entry is moved to
2527 * It succeeds only when the swap_cgroup's record for this entry is the same
2528 * as the mem_cgroup's id of @from.
2530 * Returns 0 on success, -EINVAL on failure.
2532 * The caller must have charged to @to, IOW, called page_counter_charge() about
2533 * both res and memsw, and called css_get().
2535 static int mem_cgroup_move_swap_account(swp_entry_t entry
,
2536 struct mem_cgroup
*from
, struct mem_cgroup
*to
)
2538 unsigned short old_id
, new_id
;
2540 old_id
= mem_cgroup_id(from
);
2541 new_id
= mem_cgroup_id(to
);
2543 if (swap_cgroup_cmpxchg(entry
, old_id
, new_id
) == old_id
) {
2544 mem_cgroup_swap_statistics(from
, false);
2545 mem_cgroup_swap_statistics(to
, true);
2551 static inline int mem_cgroup_move_swap_account(swp_entry_t entry
,
2552 struct mem_cgroup
*from
, struct mem_cgroup
*to
)
2558 static DEFINE_MUTEX(memcg_limit_mutex
);
2560 static int mem_cgroup_resize_limit(struct mem_cgroup
*memcg
,
2561 unsigned long limit
)
2563 unsigned long curusage
;
2564 unsigned long oldusage
;
2565 bool enlarge
= false;
2570 * For keeping hierarchical_reclaim simple, how long we should retry
2571 * is depends on callers. We set our retry-count to be function
2572 * of # of children which we should visit in this loop.
2574 retry_count
= MEM_CGROUP_RECLAIM_RETRIES
*
2575 mem_cgroup_count_children(memcg
);
2577 oldusage
= page_counter_read(&memcg
->memory
);
2580 if (signal_pending(current
)) {
2585 mutex_lock(&memcg_limit_mutex
);
2586 if (limit
> memcg
->memsw
.limit
) {
2587 mutex_unlock(&memcg_limit_mutex
);
2591 if (limit
> memcg
->memory
.limit
)
2593 ret
= page_counter_limit(&memcg
->memory
, limit
);
2594 mutex_unlock(&memcg_limit_mutex
);
2599 try_to_free_mem_cgroup_pages(memcg
, 1, GFP_KERNEL
, true);
2601 curusage
= page_counter_read(&memcg
->memory
);
2602 /* Usage is reduced ? */
2603 if (curusage
>= oldusage
)
2606 oldusage
= curusage
;
2607 } while (retry_count
);
2609 if (!ret
&& enlarge
)
2610 memcg_oom_recover(memcg
);
2615 static int mem_cgroup_resize_memsw_limit(struct mem_cgroup
*memcg
,
2616 unsigned long limit
)
2618 unsigned long curusage
;
2619 unsigned long oldusage
;
2620 bool enlarge
= false;
2624 /* see mem_cgroup_resize_res_limit */
2625 retry_count
= MEM_CGROUP_RECLAIM_RETRIES
*
2626 mem_cgroup_count_children(memcg
);
2628 oldusage
= page_counter_read(&memcg
->memsw
);
2631 if (signal_pending(current
)) {
2636 mutex_lock(&memcg_limit_mutex
);
2637 if (limit
< memcg
->memory
.limit
) {
2638 mutex_unlock(&memcg_limit_mutex
);
2642 if (limit
> memcg
->memsw
.limit
)
2644 ret
= page_counter_limit(&memcg
->memsw
, limit
);
2645 mutex_unlock(&memcg_limit_mutex
);
2650 try_to_free_mem_cgroup_pages(memcg
, 1, GFP_KERNEL
, false);
2652 curusage
= page_counter_read(&memcg
->memsw
);
2653 /* Usage is reduced ? */
2654 if (curusage
>= oldusage
)
2657 oldusage
= curusage
;
2658 } while (retry_count
);
2660 if (!ret
&& enlarge
)
2661 memcg_oom_recover(memcg
);
2666 unsigned long mem_cgroup_soft_limit_reclaim(struct zone
*zone
, int order
,
2668 unsigned long *total_scanned
)
2670 unsigned long nr_reclaimed
= 0;
2671 struct mem_cgroup_per_zone
*mz
, *next_mz
= NULL
;
2672 unsigned long reclaimed
;
2674 struct mem_cgroup_tree_per_zone
*mctz
;
2675 unsigned long excess
;
2676 unsigned long nr_scanned
;
2681 mctz
= soft_limit_tree_node_zone(zone_to_nid(zone
), zone_idx(zone
));
2683 * This loop can run a while, specially if mem_cgroup's continuously
2684 * keep exceeding their soft limit and putting the system under
2691 mz
= mem_cgroup_largest_soft_limit_node(mctz
);
2696 reclaimed
= mem_cgroup_soft_reclaim(mz
->memcg
, zone
,
2697 gfp_mask
, &nr_scanned
);
2698 nr_reclaimed
+= reclaimed
;
2699 *total_scanned
+= nr_scanned
;
2700 spin_lock_irq(&mctz
->lock
);
2701 __mem_cgroup_remove_exceeded(mz
, mctz
);
2704 * If we failed to reclaim anything from this memory cgroup
2705 * it is time to move on to the next cgroup
2709 next_mz
= __mem_cgroup_largest_soft_limit_node(mctz
);
2711 excess
= soft_limit_excess(mz
->memcg
);
2713 * One school of thought says that we should not add
2714 * back the node to the tree if reclaim returns 0.
2715 * But our reclaim could return 0, simply because due
2716 * to priority we are exposing a smaller subset of
2717 * memory to reclaim from. Consider this as a longer
2720 /* If excess == 0, no tree ops */
2721 __mem_cgroup_insert_exceeded(mz
, mctz
, excess
);
2722 spin_unlock_irq(&mctz
->lock
);
2723 css_put(&mz
->memcg
->css
);
2726 * Could not reclaim anything and there are no more
2727 * mem cgroups to try or we seem to be looping without
2728 * reclaiming anything.
2730 if (!nr_reclaimed
&&
2732 loop
> MEM_CGROUP_MAX_SOFT_LIMIT_RECLAIM_LOOPS
))
2734 } while (!nr_reclaimed
);
2736 css_put(&next_mz
->memcg
->css
);
2737 return nr_reclaimed
;
2741 * Test whether @memcg has children, dead or alive. Note that this
2742 * function doesn't care whether @memcg has use_hierarchy enabled and
2743 * returns %true if there are child csses according to the cgroup
2744 * hierarchy. Testing use_hierarchy is the caller's responsiblity.
2746 static inline bool memcg_has_children(struct mem_cgroup
*memcg
)
2751 * The lock does not prevent addition or deletion of children, but
2752 * it prevents a new child from being initialized based on this
2753 * parent in css_online(), so it's enough to decide whether
2754 * hierarchically inherited attributes can still be changed or not.
2756 lockdep_assert_held(&memcg_create_mutex
);
2759 ret
= css_next_child(NULL
, &memcg
->css
);
2765 * Reclaims as many pages from the given memcg as possible and moves
2766 * the rest to the parent.
2768 * Caller is responsible for holding css reference for memcg.
2770 static int mem_cgroup_force_empty(struct mem_cgroup
*memcg
)
2772 int nr_retries
= MEM_CGROUP_RECLAIM_RETRIES
;
2774 /* we call try-to-free pages for make this cgroup empty */
2775 lru_add_drain_all();
2776 /* try to free all pages in this cgroup */
2777 while (nr_retries
&& page_counter_read(&memcg
->memory
)) {
2780 if (signal_pending(current
))
2783 progress
= try_to_free_mem_cgroup_pages(memcg
, 1,
2787 /* maybe some writeback is necessary */
2788 congestion_wait(BLK_RW_ASYNC
, HZ
/10);
2796 static ssize_t
mem_cgroup_force_empty_write(struct kernfs_open_file
*of
,
2797 char *buf
, size_t nbytes
,
2800 struct mem_cgroup
*memcg
= mem_cgroup_from_css(of_css(of
));
2802 if (mem_cgroup_is_root(memcg
))
2804 return mem_cgroup_force_empty(memcg
) ?: nbytes
;
2807 static u64
mem_cgroup_hierarchy_read(struct cgroup_subsys_state
*css
,
2810 return mem_cgroup_from_css(css
)->use_hierarchy
;
2813 static int mem_cgroup_hierarchy_write(struct cgroup_subsys_state
*css
,
2814 struct cftype
*cft
, u64 val
)
2817 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
2818 struct mem_cgroup
*parent_memcg
= mem_cgroup_from_css(memcg
->css
.parent
);
2820 mutex_lock(&memcg_create_mutex
);
2822 if (memcg
->use_hierarchy
== val
)
2826 * If parent's use_hierarchy is set, we can't make any modifications
2827 * in the child subtrees. If it is unset, then the change can
2828 * occur, provided the current cgroup has no children.
2830 * For the root cgroup, parent_mem is NULL, we allow value to be
2831 * set if there are no children.
2833 if ((!parent_memcg
|| !parent_memcg
->use_hierarchy
) &&
2834 (val
== 1 || val
== 0)) {
2835 if (!memcg_has_children(memcg
))
2836 memcg
->use_hierarchy
= val
;
2843 mutex_unlock(&memcg_create_mutex
);
2848 static unsigned long tree_stat(struct mem_cgroup
*memcg
,
2849 enum mem_cgroup_stat_index idx
)
2851 struct mem_cgroup
*iter
;
2852 unsigned long val
= 0;
2854 for_each_mem_cgroup_tree(iter
, memcg
)
2855 val
+= mem_cgroup_read_stat(iter
, idx
);
2860 static unsigned long mem_cgroup_usage(struct mem_cgroup
*memcg
, bool swap
)
2864 if (mem_cgroup_is_root(memcg
)) {
2865 val
= tree_stat(memcg
, MEM_CGROUP_STAT_CACHE
);
2866 val
+= tree_stat(memcg
, MEM_CGROUP_STAT_RSS
);
2868 val
+= tree_stat(memcg
, MEM_CGROUP_STAT_SWAP
);
2871 val
= page_counter_read(&memcg
->memory
);
2873 val
= page_counter_read(&memcg
->memsw
);
2886 static u64
mem_cgroup_read_u64(struct cgroup_subsys_state
*css
,
2889 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
2890 struct page_counter
*counter
;
2892 switch (MEMFILE_TYPE(cft
->private)) {
2894 counter
= &memcg
->memory
;
2897 counter
= &memcg
->memsw
;
2900 counter
= &memcg
->kmem
;
2906 switch (MEMFILE_ATTR(cft
->private)) {
2908 if (counter
== &memcg
->memory
)
2909 return (u64
)mem_cgroup_usage(memcg
, false) * PAGE_SIZE
;
2910 if (counter
== &memcg
->memsw
)
2911 return (u64
)mem_cgroup_usage(memcg
, true) * PAGE_SIZE
;
2912 return (u64
)page_counter_read(counter
) * PAGE_SIZE
;
2914 return (u64
)counter
->limit
* PAGE_SIZE
;
2916 return (u64
)counter
->watermark
* PAGE_SIZE
;
2918 return counter
->failcnt
;
2919 case RES_SOFT_LIMIT
:
2920 return (u64
)memcg
->soft_limit
* PAGE_SIZE
;
2926 #ifdef CONFIG_MEMCG_KMEM
2927 static int memcg_activate_kmem(struct mem_cgroup
*memcg
,
2928 unsigned long nr_pages
)
2933 BUG_ON(memcg
->kmemcg_id
>= 0);
2934 BUG_ON(memcg
->kmem_acct_activated
);
2935 BUG_ON(memcg
->kmem_acct_active
);
2938 * For simplicity, we won't allow this to be disabled. It also can't
2939 * be changed if the cgroup has children already, or if tasks had
2942 * If tasks join before we set the limit, a person looking at
2943 * kmem.usage_in_bytes will have no way to determine when it took
2944 * place, which makes the value quite meaningless.
2946 * After it first became limited, changes in the value of the limit are
2947 * of course permitted.
2949 mutex_lock(&memcg_create_mutex
);
2950 if (cgroup_is_populated(memcg
->css
.cgroup
) ||
2951 (memcg
->use_hierarchy
&& memcg_has_children(memcg
)))
2953 mutex_unlock(&memcg_create_mutex
);
2957 memcg_id
= memcg_alloc_cache_id();
2964 * We couldn't have accounted to this cgroup, because it hasn't got
2965 * activated yet, so this should succeed.
2967 err
= page_counter_limit(&memcg
->kmem
, nr_pages
);
2970 static_key_slow_inc(&memcg_kmem_enabled_key
);
2972 * A memory cgroup is considered kmem-active as soon as it gets
2973 * kmemcg_id. Setting the id after enabling static branching will
2974 * guarantee no one starts accounting before all call sites are
2977 memcg
->kmemcg_id
= memcg_id
;
2978 memcg
->kmem_acct_activated
= true;
2979 memcg
->kmem_acct_active
= true;
2984 static int memcg_update_kmem_limit(struct mem_cgroup
*memcg
,
2985 unsigned long limit
)
2989 mutex_lock(&memcg_limit_mutex
);
2990 if (!memcg_kmem_is_active(memcg
))
2991 ret
= memcg_activate_kmem(memcg
, limit
);
2993 ret
= page_counter_limit(&memcg
->kmem
, limit
);
2994 mutex_unlock(&memcg_limit_mutex
);
2998 static int memcg_propagate_kmem(struct mem_cgroup
*memcg
)
3001 struct mem_cgroup
*parent
= parent_mem_cgroup(memcg
);
3006 mutex_lock(&memcg_limit_mutex
);
3008 * If the parent cgroup is not kmem-active now, it cannot be activated
3009 * after this point, because it has at least one child already.
3011 if (memcg_kmem_is_active(parent
))
3012 ret
= memcg_activate_kmem(memcg
, PAGE_COUNTER_MAX
);
3013 mutex_unlock(&memcg_limit_mutex
);
3017 static int memcg_update_kmem_limit(struct mem_cgroup
*memcg
,
3018 unsigned long limit
)
3022 #endif /* CONFIG_MEMCG_KMEM */
3025 * The user of this function is...
3028 static ssize_t
mem_cgroup_write(struct kernfs_open_file
*of
,
3029 char *buf
, size_t nbytes
, loff_t off
)
3031 struct mem_cgroup
*memcg
= mem_cgroup_from_css(of_css(of
));
3032 unsigned long nr_pages
;
3035 buf
= strstrip(buf
);
3036 ret
= page_counter_memparse(buf
, "-1", &nr_pages
);
3040 switch (MEMFILE_ATTR(of_cft(of
)->private)) {
3042 if (mem_cgroup_is_root(memcg
)) { /* Can't set limit on root */
3046 switch (MEMFILE_TYPE(of_cft(of
)->private)) {
3048 ret
= mem_cgroup_resize_limit(memcg
, nr_pages
);
3051 ret
= mem_cgroup_resize_memsw_limit(memcg
, nr_pages
);
3054 ret
= memcg_update_kmem_limit(memcg
, nr_pages
);
3058 case RES_SOFT_LIMIT
:
3059 memcg
->soft_limit
= nr_pages
;
3063 return ret
?: nbytes
;
3066 static ssize_t
mem_cgroup_reset(struct kernfs_open_file
*of
, char *buf
,
3067 size_t nbytes
, loff_t off
)
3069 struct mem_cgroup
*memcg
= mem_cgroup_from_css(of_css(of
));
3070 struct page_counter
*counter
;
3072 switch (MEMFILE_TYPE(of_cft(of
)->private)) {
3074 counter
= &memcg
->memory
;
3077 counter
= &memcg
->memsw
;
3080 counter
= &memcg
->kmem
;
3086 switch (MEMFILE_ATTR(of_cft(of
)->private)) {
3088 page_counter_reset_watermark(counter
);
3091 counter
->failcnt
= 0;
3100 static u64
mem_cgroup_move_charge_read(struct cgroup_subsys_state
*css
,
3103 return mem_cgroup_from_css(css
)->move_charge_at_immigrate
;
3107 static int mem_cgroup_move_charge_write(struct cgroup_subsys_state
*css
,
3108 struct cftype
*cft
, u64 val
)
3110 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
3112 if (val
& ~MOVE_MASK
)
3116 * No kind of locking is needed in here, because ->can_attach() will
3117 * check this value once in the beginning of the process, and then carry
3118 * on with stale data. This means that changes to this value will only
3119 * affect task migrations starting after the change.
3121 memcg
->move_charge_at_immigrate
= val
;
3125 static int mem_cgroup_move_charge_write(struct cgroup_subsys_state
*css
,
3126 struct cftype
*cft
, u64 val
)
3133 static int memcg_numa_stat_show(struct seq_file
*m
, void *v
)
3137 unsigned int lru_mask
;
3140 static const struct numa_stat stats
[] = {
3141 { "total", LRU_ALL
},
3142 { "file", LRU_ALL_FILE
},
3143 { "anon", LRU_ALL_ANON
},
3144 { "unevictable", BIT(LRU_UNEVICTABLE
) },
3146 const struct numa_stat
*stat
;
3149 struct mem_cgroup
*memcg
= mem_cgroup_from_css(seq_css(m
));
3151 for (stat
= stats
; stat
< stats
+ ARRAY_SIZE(stats
); stat
++) {
3152 nr
= mem_cgroup_nr_lru_pages(memcg
, stat
->lru_mask
);
3153 seq_printf(m
, "%s=%lu", stat
->name
, nr
);
3154 for_each_node_state(nid
, N_MEMORY
) {
3155 nr
= mem_cgroup_node_nr_lru_pages(memcg
, nid
,
3157 seq_printf(m
, " N%d=%lu", nid
, nr
);
3162 for (stat
= stats
; stat
< stats
+ ARRAY_SIZE(stats
); stat
++) {
3163 struct mem_cgroup
*iter
;
3166 for_each_mem_cgroup_tree(iter
, memcg
)
3167 nr
+= mem_cgroup_nr_lru_pages(iter
, stat
->lru_mask
);
3168 seq_printf(m
, "hierarchical_%s=%lu", stat
->name
, nr
);
3169 for_each_node_state(nid
, N_MEMORY
) {
3171 for_each_mem_cgroup_tree(iter
, memcg
)
3172 nr
+= mem_cgroup_node_nr_lru_pages(
3173 iter
, nid
, stat
->lru_mask
);
3174 seq_printf(m
, " N%d=%lu", nid
, nr
);
3181 #endif /* CONFIG_NUMA */
3183 static int memcg_stat_show(struct seq_file
*m
, void *v
)
3185 struct mem_cgroup
*memcg
= mem_cgroup_from_css(seq_css(m
));
3186 unsigned long memory
, memsw
;
3187 struct mem_cgroup
*mi
;
3190 BUILD_BUG_ON(ARRAY_SIZE(mem_cgroup_stat_names
) !=
3191 MEM_CGROUP_STAT_NSTATS
);
3192 BUILD_BUG_ON(ARRAY_SIZE(mem_cgroup_events_names
) !=
3193 MEM_CGROUP_EVENTS_NSTATS
);
3194 BUILD_BUG_ON(ARRAY_SIZE(mem_cgroup_lru_names
) != NR_LRU_LISTS
);
3196 for (i
= 0; i
< MEM_CGROUP_STAT_NSTATS
; i
++) {
3197 if (i
== MEM_CGROUP_STAT_SWAP
&& !do_swap_account
)
3199 seq_printf(m
, "%s %lu\n", mem_cgroup_stat_names
[i
],
3200 mem_cgroup_read_stat(memcg
, i
) * PAGE_SIZE
);
3203 for (i
= 0; i
< MEM_CGROUP_EVENTS_NSTATS
; i
++)
3204 seq_printf(m
, "%s %lu\n", mem_cgroup_events_names
[i
],
3205 mem_cgroup_read_events(memcg
, i
));
3207 for (i
= 0; i
< NR_LRU_LISTS
; i
++)
3208 seq_printf(m
, "%s %lu\n", mem_cgroup_lru_names
[i
],
3209 mem_cgroup_nr_lru_pages(memcg
, BIT(i
)) * PAGE_SIZE
);
3211 /* Hierarchical information */
3212 memory
= memsw
= PAGE_COUNTER_MAX
;
3213 for (mi
= memcg
; mi
; mi
= parent_mem_cgroup(mi
)) {
3214 memory
= min(memory
, mi
->memory
.limit
);
3215 memsw
= min(memsw
, mi
->memsw
.limit
);
3217 seq_printf(m
, "hierarchical_memory_limit %llu\n",
3218 (u64
)memory
* PAGE_SIZE
);
3219 if (do_swap_account
)
3220 seq_printf(m
, "hierarchical_memsw_limit %llu\n",
3221 (u64
)memsw
* PAGE_SIZE
);
3223 for (i
= 0; i
< MEM_CGROUP_STAT_NSTATS
; i
++) {
3224 unsigned long long val
= 0;
3226 if (i
== MEM_CGROUP_STAT_SWAP
&& !do_swap_account
)
3228 for_each_mem_cgroup_tree(mi
, memcg
)
3229 val
+= mem_cgroup_read_stat(mi
, i
) * PAGE_SIZE
;
3230 seq_printf(m
, "total_%s %llu\n", mem_cgroup_stat_names
[i
], val
);
3233 for (i
= 0; i
< MEM_CGROUP_EVENTS_NSTATS
; i
++) {
3234 unsigned long long val
= 0;
3236 for_each_mem_cgroup_tree(mi
, memcg
)
3237 val
+= mem_cgroup_read_events(mi
, i
);
3238 seq_printf(m
, "total_%s %llu\n",
3239 mem_cgroup_events_names
[i
], val
);
3242 for (i
= 0; i
< NR_LRU_LISTS
; i
++) {
3243 unsigned long long val
= 0;
3245 for_each_mem_cgroup_tree(mi
, memcg
)
3246 val
+= mem_cgroup_nr_lru_pages(mi
, BIT(i
)) * PAGE_SIZE
;
3247 seq_printf(m
, "total_%s %llu\n", mem_cgroup_lru_names
[i
], val
);
3250 #ifdef CONFIG_DEBUG_VM
3253 struct mem_cgroup_per_zone
*mz
;
3254 struct zone_reclaim_stat
*rstat
;
3255 unsigned long recent_rotated
[2] = {0, 0};
3256 unsigned long recent_scanned
[2] = {0, 0};
3258 for_each_online_node(nid
)
3259 for (zid
= 0; zid
< MAX_NR_ZONES
; zid
++) {
3260 mz
= &memcg
->nodeinfo
[nid
]->zoneinfo
[zid
];
3261 rstat
= &mz
->lruvec
.reclaim_stat
;
3263 recent_rotated
[0] += rstat
->recent_rotated
[0];
3264 recent_rotated
[1] += rstat
->recent_rotated
[1];
3265 recent_scanned
[0] += rstat
->recent_scanned
[0];
3266 recent_scanned
[1] += rstat
->recent_scanned
[1];
3268 seq_printf(m
, "recent_rotated_anon %lu\n", recent_rotated
[0]);
3269 seq_printf(m
, "recent_rotated_file %lu\n", recent_rotated
[1]);
3270 seq_printf(m
, "recent_scanned_anon %lu\n", recent_scanned
[0]);
3271 seq_printf(m
, "recent_scanned_file %lu\n", recent_scanned
[1]);
3278 static u64
mem_cgroup_swappiness_read(struct cgroup_subsys_state
*css
,
3281 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
3283 return mem_cgroup_swappiness(memcg
);
3286 static int mem_cgroup_swappiness_write(struct cgroup_subsys_state
*css
,
3287 struct cftype
*cft
, u64 val
)
3289 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
3295 memcg
->swappiness
= val
;
3297 vm_swappiness
= val
;
3302 static void __mem_cgroup_threshold(struct mem_cgroup
*memcg
, bool swap
)
3304 struct mem_cgroup_threshold_ary
*t
;
3305 unsigned long usage
;
3310 t
= rcu_dereference(memcg
->thresholds
.primary
);
3312 t
= rcu_dereference(memcg
->memsw_thresholds
.primary
);
3317 usage
= mem_cgroup_usage(memcg
, swap
);
3320 * current_threshold points to threshold just below or equal to usage.
3321 * If it's not true, a threshold was crossed after last
3322 * call of __mem_cgroup_threshold().
3324 i
= t
->current_threshold
;
3327 * Iterate backward over array of thresholds starting from
3328 * current_threshold and check if a threshold is crossed.
3329 * If none of thresholds below usage is crossed, we read
3330 * only one element of the array here.
3332 for (; i
>= 0 && unlikely(t
->entries
[i
].threshold
> usage
); i
--)
3333 eventfd_signal(t
->entries
[i
].eventfd
, 1);
3335 /* i = current_threshold + 1 */
3339 * Iterate forward over array of thresholds starting from
3340 * current_threshold+1 and check if a threshold is crossed.
3341 * If none of thresholds above usage is crossed, we read
3342 * only one element of the array here.
3344 for (; i
< t
->size
&& unlikely(t
->entries
[i
].threshold
<= usage
); i
++)
3345 eventfd_signal(t
->entries
[i
].eventfd
, 1);
3347 /* Update current_threshold */
3348 t
->current_threshold
= i
- 1;
3353 static void mem_cgroup_threshold(struct mem_cgroup
*memcg
)
3356 __mem_cgroup_threshold(memcg
, false);
3357 if (do_swap_account
)
3358 __mem_cgroup_threshold(memcg
, true);
3360 memcg
= parent_mem_cgroup(memcg
);
3364 static int compare_thresholds(const void *a
, const void *b
)
3366 const struct mem_cgroup_threshold
*_a
= a
;
3367 const struct mem_cgroup_threshold
*_b
= b
;
3369 if (_a
->threshold
> _b
->threshold
)
3372 if (_a
->threshold
< _b
->threshold
)
3378 static int mem_cgroup_oom_notify_cb(struct mem_cgroup
*memcg
)
3380 struct mem_cgroup_eventfd_list
*ev
;
3382 spin_lock(&memcg_oom_lock
);
3384 list_for_each_entry(ev
, &memcg
->oom_notify
, list
)
3385 eventfd_signal(ev
->eventfd
, 1);
3387 spin_unlock(&memcg_oom_lock
);
3391 static void mem_cgroup_oom_notify(struct mem_cgroup
*memcg
)
3393 struct mem_cgroup
*iter
;
3395 for_each_mem_cgroup_tree(iter
, memcg
)
3396 mem_cgroup_oom_notify_cb(iter
);
3399 static int __mem_cgroup_usage_register_event(struct mem_cgroup
*memcg
,
3400 struct eventfd_ctx
*eventfd
, const char *args
, enum res_type type
)
3402 struct mem_cgroup_thresholds
*thresholds
;
3403 struct mem_cgroup_threshold_ary
*new;
3404 unsigned long threshold
;
3405 unsigned long usage
;
3408 ret
= page_counter_memparse(args
, "-1", &threshold
);
3412 mutex_lock(&memcg
->thresholds_lock
);
3415 thresholds
= &memcg
->thresholds
;
3416 usage
= mem_cgroup_usage(memcg
, false);
3417 } else if (type
== _MEMSWAP
) {
3418 thresholds
= &memcg
->memsw_thresholds
;
3419 usage
= mem_cgroup_usage(memcg
, true);
3423 /* Check if a threshold crossed before adding a new one */
3424 if (thresholds
->primary
)
3425 __mem_cgroup_threshold(memcg
, type
== _MEMSWAP
);
3427 size
= thresholds
->primary
? thresholds
->primary
->size
+ 1 : 1;
3429 /* Allocate memory for new array of thresholds */
3430 new = kmalloc(sizeof(*new) + size
* sizeof(struct mem_cgroup_threshold
),
3438 /* Copy thresholds (if any) to new array */
3439 if (thresholds
->primary
) {
3440 memcpy(new->entries
, thresholds
->primary
->entries
, (size
- 1) *
3441 sizeof(struct mem_cgroup_threshold
));
3444 /* Add new threshold */
3445 new->entries
[size
- 1].eventfd
= eventfd
;
3446 new->entries
[size
- 1].threshold
= threshold
;
3448 /* Sort thresholds. Registering of new threshold isn't time-critical */
3449 sort(new->entries
, size
, sizeof(struct mem_cgroup_threshold
),
3450 compare_thresholds
, NULL
);
3452 /* Find current threshold */
3453 new->current_threshold
= -1;
3454 for (i
= 0; i
< size
; i
++) {
3455 if (new->entries
[i
].threshold
<= usage
) {
3457 * new->current_threshold will not be used until
3458 * rcu_assign_pointer(), so it's safe to increment
3461 ++new->current_threshold
;
3466 /* Free old spare buffer and save old primary buffer as spare */
3467 kfree(thresholds
->spare
);
3468 thresholds
->spare
= thresholds
->primary
;
3470 rcu_assign_pointer(thresholds
->primary
, new);
3472 /* To be sure that nobody uses thresholds */
3476 mutex_unlock(&memcg
->thresholds_lock
);
3481 static int mem_cgroup_usage_register_event(struct mem_cgroup
*memcg
,
3482 struct eventfd_ctx
*eventfd
, const char *args
)
3484 return __mem_cgroup_usage_register_event(memcg
, eventfd
, args
, _MEM
);
3487 static int memsw_cgroup_usage_register_event(struct mem_cgroup
*memcg
,
3488 struct eventfd_ctx
*eventfd
, const char *args
)
3490 return __mem_cgroup_usage_register_event(memcg
, eventfd
, args
, _MEMSWAP
);
3493 static void __mem_cgroup_usage_unregister_event(struct mem_cgroup
*memcg
,
3494 struct eventfd_ctx
*eventfd
, enum res_type type
)
3496 struct mem_cgroup_thresholds
*thresholds
;
3497 struct mem_cgroup_threshold_ary
*new;
3498 unsigned long usage
;
3501 mutex_lock(&memcg
->thresholds_lock
);
3504 thresholds
= &memcg
->thresholds
;
3505 usage
= mem_cgroup_usage(memcg
, false);
3506 } else if (type
== _MEMSWAP
) {
3507 thresholds
= &memcg
->memsw_thresholds
;
3508 usage
= mem_cgroup_usage(memcg
, true);
3512 if (!thresholds
->primary
)
3515 /* Check if a threshold crossed before removing */
3516 __mem_cgroup_threshold(memcg
, type
== _MEMSWAP
);
3518 /* Calculate new number of threshold */
3520 for (i
= 0; i
< thresholds
->primary
->size
; i
++) {
3521 if (thresholds
->primary
->entries
[i
].eventfd
!= eventfd
)
3525 new = thresholds
->spare
;
3527 /* Set thresholds array to NULL if we don't have thresholds */
3536 /* Copy thresholds and find current threshold */
3537 new->current_threshold
= -1;
3538 for (i
= 0, j
= 0; i
< thresholds
->primary
->size
; i
++) {
3539 if (thresholds
->primary
->entries
[i
].eventfd
== eventfd
)
3542 new->entries
[j
] = thresholds
->primary
->entries
[i
];
3543 if (new->entries
[j
].threshold
<= usage
) {
3545 * new->current_threshold will not be used
3546 * until rcu_assign_pointer(), so it's safe to increment
3549 ++new->current_threshold
;
3555 /* Swap primary and spare array */
3556 thresholds
->spare
= thresholds
->primary
;
3557 /* If all events are unregistered, free the spare array */
3559 kfree(thresholds
->spare
);
3560 thresholds
->spare
= NULL
;
3563 rcu_assign_pointer(thresholds
->primary
, new);
3565 /* To be sure that nobody uses thresholds */
3568 mutex_unlock(&memcg
->thresholds_lock
);
3571 static void mem_cgroup_usage_unregister_event(struct mem_cgroup
*memcg
,
3572 struct eventfd_ctx
*eventfd
)
3574 return __mem_cgroup_usage_unregister_event(memcg
, eventfd
, _MEM
);
3577 static void memsw_cgroup_usage_unregister_event(struct mem_cgroup
*memcg
,
3578 struct eventfd_ctx
*eventfd
)
3580 return __mem_cgroup_usage_unregister_event(memcg
, eventfd
, _MEMSWAP
);
3583 static int mem_cgroup_oom_register_event(struct mem_cgroup
*memcg
,
3584 struct eventfd_ctx
*eventfd
, const char *args
)
3586 struct mem_cgroup_eventfd_list
*event
;
3588 event
= kmalloc(sizeof(*event
), GFP_KERNEL
);
3592 spin_lock(&memcg_oom_lock
);
3594 event
->eventfd
= eventfd
;
3595 list_add(&event
->list
, &memcg
->oom_notify
);
3597 /* already in OOM ? */
3598 if (memcg
->under_oom
)
3599 eventfd_signal(eventfd
, 1);
3600 spin_unlock(&memcg_oom_lock
);
3605 static void mem_cgroup_oom_unregister_event(struct mem_cgroup
*memcg
,
3606 struct eventfd_ctx
*eventfd
)
3608 struct mem_cgroup_eventfd_list
*ev
, *tmp
;
3610 spin_lock(&memcg_oom_lock
);
3612 list_for_each_entry_safe(ev
, tmp
, &memcg
->oom_notify
, list
) {
3613 if (ev
->eventfd
== eventfd
) {
3614 list_del(&ev
->list
);
3619 spin_unlock(&memcg_oom_lock
);
3622 static int mem_cgroup_oom_control_read(struct seq_file
*sf
, void *v
)
3624 struct mem_cgroup
*memcg
= mem_cgroup_from_css(seq_css(sf
));
3626 seq_printf(sf
, "oom_kill_disable %d\n", memcg
->oom_kill_disable
);
3627 seq_printf(sf
, "under_oom %d\n", (bool)memcg
->under_oom
);
3631 static int mem_cgroup_oom_control_write(struct cgroup_subsys_state
*css
,
3632 struct cftype
*cft
, u64 val
)
3634 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
3636 /* cannot set to root cgroup and only 0 and 1 are allowed */
3637 if (!css
->parent
|| !((val
== 0) || (val
== 1)))
3640 memcg
->oom_kill_disable
= val
;
3642 memcg_oom_recover(memcg
);
3647 #ifdef CONFIG_MEMCG_KMEM
3648 static int memcg_init_kmem(struct mem_cgroup
*memcg
, struct cgroup_subsys
*ss
)
3652 ret
= memcg_propagate_kmem(memcg
);
3656 return mem_cgroup_sockets_init(memcg
, ss
);
3659 static void memcg_deactivate_kmem(struct mem_cgroup
*memcg
)
3661 struct cgroup_subsys_state
*css
;
3662 struct mem_cgroup
*parent
, *child
;
3665 if (!memcg
->kmem_acct_active
)
3669 * Clear the 'active' flag before clearing memcg_caches arrays entries.
3670 * Since we take the slab_mutex in memcg_deactivate_kmem_caches(), it
3671 * guarantees no cache will be created for this cgroup after we are
3672 * done (see memcg_create_kmem_cache()).
3674 memcg
->kmem_acct_active
= false;
3676 memcg_deactivate_kmem_caches(memcg
);
3678 kmemcg_id
= memcg
->kmemcg_id
;
3679 BUG_ON(kmemcg_id
< 0);
3681 parent
= parent_mem_cgroup(memcg
);
3683 parent
= root_mem_cgroup
;
3686 * Change kmemcg_id of this cgroup and all its descendants to the
3687 * parent's id, and then move all entries from this cgroup's list_lrus
3688 * to ones of the parent. After we have finished, all list_lrus
3689 * corresponding to this cgroup are guaranteed to remain empty. The
3690 * ordering is imposed by list_lru_node->lock taken by
3691 * memcg_drain_all_list_lrus().
3693 css_for_each_descendant_pre(css
, &memcg
->css
) {
3694 child
= mem_cgroup_from_css(css
);
3695 BUG_ON(child
->kmemcg_id
!= kmemcg_id
);
3696 child
->kmemcg_id
= parent
->kmemcg_id
;
3697 if (!memcg
->use_hierarchy
)
3700 memcg_drain_all_list_lrus(kmemcg_id
, parent
->kmemcg_id
);
3702 memcg_free_cache_id(kmemcg_id
);
3705 static void memcg_destroy_kmem(struct mem_cgroup
*memcg
)
3707 if (memcg
->kmem_acct_activated
) {
3708 memcg_destroy_kmem_caches(memcg
);
3709 static_key_slow_dec(&memcg_kmem_enabled_key
);
3710 WARN_ON(page_counter_read(&memcg
->kmem
));
3712 mem_cgroup_sockets_destroy(memcg
);
3715 static int memcg_init_kmem(struct mem_cgroup
*memcg
, struct cgroup_subsys
*ss
)
3720 static void memcg_deactivate_kmem(struct mem_cgroup
*memcg
)
3724 static void memcg_destroy_kmem(struct mem_cgroup
*memcg
)
3729 #ifdef CONFIG_CGROUP_WRITEBACK
3731 struct list_head
*mem_cgroup_cgwb_list(struct mem_cgroup
*memcg
)
3733 return &memcg
->cgwb_list
;
3736 static int memcg_wb_domain_init(struct mem_cgroup
*memcg
, gfp_t gfp
)
3738 return wb_domain_init(&memcg
->cgwb_domain
, gfp
);
3741 static void memcg_wb_domain_exit(struct mem_cgroup
*memcg
)
3743 wb_domain_exit(&memcg
->cgwb_domain
);
3746 static void memcg_wb_domain_size_changed(struct mem_cgroup
*memcg
)
3748 wb_domain_size_changed(&memcg
->cgwb_domain
);
3751 struct wb_domain
*mem_cgroup_wb_domain(struct bdi_writeback
*wb
)
3753 struct mem_cgroup
*memcg
= mem_cgroup_from_css(wb
->memcg_css
);
3755 if (!memcg
->css
.parent
)
3758 return &memcg
->cgwb_domain
;
3762 * mem_cgroup_wb_stats - retrieve writeback related stats from its memcg
3763 * @wb: bdi_writeback in question
3764 * @pfilepages: out parameter for number of file pages
3765 * @pheadroom: out parameter for number of allocatable pages according to memcg
3766 * @pdirty: out parameter for number of dirty pages
3767 * @pwriteback: out parameter for number of pages under writeback
3769 * Determine the numbers of file, headroom, dirty, and writeback pages in
3770 * @wb's memcg. File, dirty and writeback are self-explanatory. Headroom
3771 * is a bit more involved.
3773 * A memcg's headroom is "min(max, high) - used". In the hierarchy, the
3774 * headroom is calculated as the lowest headroom of itself and the
3775 * ancestors. Note that this doesn't consider the actual amount of
3776 * available memory in the system. The caller should further cap
3777 * *@pheadroom accordingly.
3779 void mem_cgroup_wb_stats(struct bdi_writeback
*wb
, unsigned long *pfilepages
,
3780 unsigned long *pheadroom
, unsigned long *pdirty
,
3781 unsigned long *pwriteback
)
3783 struct mem_cgroup
*memcg
= mem_cgroup_from_css(wb
->memcg_css
);
3784 struct mem_cgroup
*parent
;
3786 *pdirty
= mem_cgroup_read_stat(memcg
, MEM_CGROUP_STAT_DIRTY
);
3788 /* this should eventually include NR_UNSTABLE_NFS */
3789 *pwriteback
= mem_cgroup_read_stat(memcg
, MEM_CGROUP_STAT_WRITEBACK
);
3790 *pfilepages
= mem_cgroup_nr_lru_pages(memcg
, (1 << LRU_INACTIVE_FILE
) |
3791 (1 << LRU_ACTIVE_FILE
));
3792 *pheadroom
= PAGE_COUNTER_MAX
;
3794 while ((parent
= parent_mem_cgroup(memcg
))) {
3795 unsigned long ceiling
= min(memcg
->memory
.limit
, memcg
->high
);
3796 unsigned long used
= page_counter_read(&memcg
->memory
);
3798 *pheadroom
= min(*pheadroom
, ceiling
- min(ceiling
, used
));
3803 #else /* CONFIG_CGROUP_WRITEBACK */
3805 static int memcg_wb_domain_init(struct mem_cgroup
*memcg
, gfp_t gfp
)
3810 static void memcg_wb_domain_exit(struct mem_cgroup
*memcg
)
3814 static void memcg_wb_domain_size_changed(struct mem_cgroup
*memcg
)
3818 #endif /* CONFIG_CGROUP_WRITEBACK */
3821 * DO NOT USE IN NEW FILES.
3823 * "cgroup.event_control" implementation.
3825 * This is way over-engineered. It tries to support fully configurable
3826 * events for each user. Such level of flexibility is completely
3827 * unnecessary especially in the light of the planned unified hierarchy.
3829 * Please deprecate this and replace with something simpler if at all
3834 * Unregister event and free resources.
3836 * Gets called from workqueue.
3838 static void memcg_event_remove(struct work_struct
*work
)
3840 struct mem_cgroup_event
*event
=
3841 container_of(work
, struct mem_cgroup_event
, remove
);
3842 struct mem_cgroup
*memcg
= event
->memcg
;
3844 remove_wait_queue(event
->wqh
, &event
->wait
);
3846 event
->unregister_event(memcg
, event
->eventfd
);
3848 /* Notify userspace the event is going away. */
3849 eventfd_signal(event
->eventfd
, 1);
3851 eventfd_ctx_put(event
->eventfd
);
3853 css_put(&memcg
->css
);
3857 * Gets called on POLLHUP on eventfd when user closes it.
3859 * Called with wqh->lock held and interrupts disabled.
3861 static int memcg_event_wake(wait_queue_t
*wait
, unsigned mode
,
3862 int sync
, void *key
)
3864 struct mem_cgroup_event
*event
=
3865 container_of(wait
, struct mem_cgroup_event
, wait
);
3866 struct mem_cgroup
*memcg
= event
->memcg
;
3867 unsigned long flags
= (unsigned long)key
;
3869 if (flags
& POLLHUP
) {
3871 * If the event has been detached at cgroup removal, we
3872 * can simply return knowing the other side will cleanup
3875 * We can't race against event freeing since the other
3876 * side will require wqh->lock via remove_wait_queue(),
3879 spin_lock(&memcg
->event_list_lock
);
3880 if (!list_empty(&event
->list
)) {
3881 list_del_init(&event
->list
);
3883 * We are in atomic context, but cgroup_event_remove()
3884 * may sleep, so we have to call it in workqueue.
3886 schedule_work(&event
->remove
);
3888 spin_unlock(&memcg
->event_list_lock
);
3894 static void memcg_event_ptable_queue_proc(struct file
*file
,
3895 wait_queue_head_t
*wqh
, poll_table
*pt
)
3897 struct mem_cgroup_event
*event
=
3898 container_of(pt
, struct mem_cgroup_event
, pt
);
3901 add_wait_queue(wqh
, &event
->wait
);
3905 * DO NOT USE IN NEW FILES.
3907 * Parse input and register new cgroup event handler.
3909 * Input must be in format '<event_fd> <control_fd> <args>'.
3910 * Interpretation of args is defined by control file implementation.
3912 static ssize_t
memcg_write_event_control(struct kernfs_open_file
*of
,
3913 char *buf
, size_t nbytes
, loff_t off
)
3915 struct cgroup_subsys_state
*css
= of_css(of
);
3916 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
3917 struct mem_cgroup_event
*event
;
3918 struct cgroup_subsys_state
*cfile_css
;
3919 unsigned int efd
, cfd
;
3926 buf
= strstrip(buf
);
3928 efd
= simple_strtoul(buf
, &endp
, 10);
3933 cfd
= simple_strtoul(buf
, &endp
, 10);
3934 if ((*endp
!= ' ') && (*endp
!= '\0'))
3938 event
= kzalloc(sizeof(*event
), GFP_KERNEL
);
3942 event
->memcg
= memcg
;
3943 INIT_LIST_HEAD(&event
->list
);
3944 init_poll_funcptr(&event
->pt
, memcg_event_ptable_queue_proc
);
3945 init_waitqueue_func_entry(&event
->wait
, memcg_event_wake
);
3946 INIT_WORK(&event
->remove
, memcg_event_remove
);
3954 event
->eventfd
= eventfd_ctx_fileget(efile
.file
);
3955 if (IS_ERR(event
->eventfd
)) {
3956 ret
= PTR_ERR(event
->eventfd
);
3963 goto out_put_eventfd
;
3966 /* the process need read permission on control file */
3967 /* AV: shouldn't we check that it's been opened for read instead? */
3968 ret
= inode_permission(file_inode(cfile
.file
), MAY_READ
);
3973 * Determine the event callbacks and set them in @event. This used
3974 * to be done via struct cftype but cgroup core no longer knows
3975 * about these events. The following is crude but the whole thing
3976 * is for compatibility anyway.
3978 * DO NOT ADD NEW FILES.
3980 name
= cfile
.file
->f_path
.dentry
->d_name
.name
;
3982 if (!strcmp(name
, "memory.usage_in_bytes")) {
3983 event
->register_event
= mem_cgroup_usage_register_event
;
3984 event
->unregister_event
= mem_cgroup_usage_unregister_event
;
3985 } else if (!strcmp(name
, "memory.oom_control")) {
3986 event
->register_event
= mem_cgroup_oom_register_event
;
3987 event
->unregister_event
= mem_cgroup_oom_unregister_event
;
3988 } else if (!strcmp(name
, "memory.pressure_level")) {
3989 event
->register_event
= vmpressure_register_event
;
3990 event
->unregister_event
= vmpressure_unregister_event
;
3991 } else if (!strcmp(name
, "memory.memsw.usage_in_bytes")) {
3992 event
->register_event
= memsw_cgroup_usage_register_event
;
3993 event
->unregister_event
= memsw_cgroup_usage_unregister_event
;
4000 * Verify @cfile should belong to @css. Also, remaining events are
4001 * automatically removed on cgroup destruction but the removal is
4002 * asynchronous, so take an extra ref on @css.
4004 cfile_css
= css_tryget_online_from_dir(cfile
.file
->f_path
.dentry
->d_parent
,
4005 &memory_cgrp_subsys
);
4007 if (IS_ERR(cfile_css
))
4009 if (cfile_css
!= css
) {
4014 ret
= event
->register_event(memcg
, event
->eventfd
, buf
);
4018 efile
.file
->f_op
->poll(efile
.file
, &event
->pt
);
4020 spin_lock(&memcg
->event_list_lock
);
4021 list_add(&event
->list
, &memcg
->event_list
);
4022 spin_unlock(&memcg
->event_list_lock
);
4034 eventfd_ctx_put(event
->eventfd
);
4043 static struct cftype mem_cgroup_legacy_files
[] = {
4045 .name
= "usage_in_bytes",
4046 .private = MEMFILE_PRIVATE(_MEM
, RES_USAGE
),
4047 .read_u64
= mem_cgroup_read_u64
,
4050 .name
= "max_usage_in_bytes",
4051 .private = MEMFILE_PRIVATE(_MEM
, RES_MAX_USAGE
),
4052 .write
= mem_cgroup_reset
,
4053 .read_u64
= mem_cgroup_read_u64
,
4056 .name
= "limit_in_bytes",
4057 .private = MEMFILE_PRIVATE(_MEM
, RES_LIMIT
),
4058 .write
= mem_cgroup_write
,
4059 .read_u64
= mem_cgroup_read_u64
,
4062 .name
= "soft_limit_in_bytes",
4063 .private = MEMFILE_PRIVATE(_MEM
, RES_SOFT_LIMIT
),
4064 .write
= mem_cgroup_write
,
4065 .read_u64
= mem_cgroup_read_u64
,
4069 .private = MEMFILE_PRIVATE(_MEM
, RES_FAILCNT
),
4070 .write
= mem_cgroup_reset
,
4071 .read_u64
= mem_cgroup_read_u64
,
4075 .seq_show
= memcg_stat_show
,
4078 .name
= "force_empty",
4079 .write
= mem_cgroup_force_empty_write
,
4082 .name
= "use_hierarchy",
4083 .write_u64
= mem_cgroup_hierarchy_write
,
4084 .read_u64
= mem_cgroup_hierarchy_read
,
4087 .name
= "cgroup.event_control", /* XXX: for compat */
4088 .write
= memcg_write_event_control
,
4089 .flags
= CFTYPE_NO_PREFIX
| CFTYPE_WORLD_WRITABLE
,
4092 .name
= "swappiness",
4093 .read_u64
= mem_cgroup_swappiness_read
,
4094 .write_u64
= mem_cgroup_swappiness_write
,
4097 .name
= "move_charge_at_immigrate",
4098 .read_u64
= mem_cgroup_move_charge_read
,
4099 .write_u64
= mem_cgroup_move_charge_write
,
4102 .name
= "oom_control",
4103 .seq_show
= mem_cgroup_oom_control_read
,
4104 .write_u64
= mem_cgroup_oom_control_write
,
4105 .private = MEMFILE_PRIVATE(_OOM_TYPE
, OOM_CONTROL
),
4108 .name
= "pressure_level",
4112 .name
= "numa_stat",
4113 .seq_show
= memcg_numa_stat_show
,
4116 #ifdef CONFIG_MEMCG_KMEM
4118 .name
= "kmem.limit_in_bytes",
4119 .private = MEMFILE_PRIVATE(_KMEM
, RES_LIMIT
),
4120 .write
= mem_cgroup_write
,
4121 .read_u64
= mem_cgroup_read_u64
,
4124 .name
= "kmem.usage_in_bytes",
4125 .private = MEMFILE_PRIVATE(_KMEM
, RES_USAGE
),
4126 .read_u64
= mem_cgroup_read_u64
,
4129 .name
= "kmem.failcnt",
4130 .private = MEMFILE_PRIVATE(_KMEM
, RES_FAILCNT
),
4131 .write
= mem_cgroup_reset
,
4132 .read_u64
= mem_cgroup_read_u64
,
4135 .name
= "kmem.max_usage_in_bytes",
4136 .private = MEMFILE_PRIVATE(_KMEM
, RES_MAX_USAGE
),
4137 .write
= mem_cgroup_reset
,
4138 .read_u64
= mem_cgroup_read_u64
,
4140 #ifdef CONFIG_SLABINFO
4142 .name
= "kmem.slabinfo",
4143 .seq_start
= slab_start
,
4144 .seq_next
= slab_next
,
4145 .seq_stop
= slab_stop
,
4146 .seq_show
= memcg_slab_show
,
4150 { }, /* terminate */
4153 static int alloc_mem_cgroup_per_zone_info(struct mem_cgroup
*memcg
, int node
)
4155 struct mem_cgroup_per_node
*pn
;
4156 struct mem_cgroup_per_zone
*mz
;
4157 int zone
, tmp
= node
;
4159 * This routine is called against possible nodes.
4160 * But it's BUG to call kmalloc() against offline node.
4162 * TODO: this routine can waste much memory for nodes which will
4163 * never be onlined. It's better to use memory hotplug callback
4166 if (!node_state(node
, N_NORMAL_MEMORY
))
4168 pn
= kzalloc_node(sizeof(*pn
), GFP_KERNEL
, tmp
);
4172 for (zone
= 0; zone
< MAX_NR_ZONES
; zone
++) {
4173 mz
= &pn
->zoneinfo
[zone
];
4174 lruvec_init(&mz
->lruvec
);
4175 mz
->usage_in_excess
= 0;
4176 mz
->on_tree
= false;
4179 memcg
->nodeinfo
[node
] = pn
;
4183 static void free_mem_cgroup_per_zone_info(struct mem_cgroup
*memcg
, int node
)
4185 kfree(memcg
->nodeinfo
[node
]);
4188 static struct mem_cgroup
*mem_cgroup_alloc(void)
4190 struct mem_cgroup
*memcg
;
4193 size
= sizeof(struct mem_cgroup
);
4194 size
+= nr_node_ids
* sizeof(struct mem_cgroup_per_node
*);
4196 memcg
= kzalloc(size
, GFP_KERNEL
);
4200 memcg
->stat
= alloc_percpu(struct mem_cgroup_stat_cpu
);
4204 if (memcg_wb_domain_init(memcg
, GFP_KERNEL
))
4210 free_percpu(memcg
->stat
);
4217 * At destroying mem_cgroup, references from swap_cgroup can remain.
4218 * (scanning all at force_empty is too costly...)
4220 * Instead of clearing all references at force_empty, we remember
4221 * the number of reference from swap_cgroup and free mem_cgroup when
4222 * it goes down to 0.
4224 * Removal of cgroup itself succeeds regardless of refs from swap.
4227 static void __mem_cgroup_free(struct mem_cgroup
*memcg
)
4231 mem_cgroup_remove_from_trees(memcg
);
4234 free_mem_cgroup_per_zone_info(memcg
, node
);
4236 free_percpu(memcg
->stat
);
4237 memcg_wb_domain_exit(memcg
);
4242 * Returns the parent mem_cgroup in memcgroup hierarchy with hierarchy enabled.
4244 struct mem_cgroup
*parent_mem_cgroup(struct mem_cgroup
*memcg
)
4246 if (!memcg
->memory
.parent
)
4248 return mem_cgroup_from_counter(memcg
->memory
.parent
, memory
);
4250 EXPORT_SYMBOL(parent_mem_cgroup
);
4252 static struct cgroup_subsys_state
* __ref
4253 mem_cgroup_css_alloc(struct cgroup_subsys_state
*parent_css
)
4255 struct mem_cgroup
*memcg
;
4256 long error
= -ENOMEM
;
4259 memcg
= mem_cgroup_alloc();
4261 return ERR_PTR(error
);
4264 if (alloc_mem_cgroup_per_zone_info(memcg
, node
))
4268 if (parent_css
== NULL
) {
4269 root_mem_cgroup
= memcg
;
4270 page_counter_init(&memcg
->memory
, NULL
);
4271 memcg
->high
= PAGE_COUNTER_MAX
;
4272 memcg
->soft_limit
= PAGE_COUNTER_MAX
;
4273 page_counter_init(&memcg
->memsw
, NULL
);
4274 page_counter_init(&memcg
->kmem
, NULL
);
4277 memcg
->last_scanned_node
= MAX_NUMNODES
;
4278 INIT_LIST_HEAD(&memcg
->oom_notify
);
4279 memcg
->move_charge_at_immigrate
= 0;
4280 mutex_init(&memcg
->thresholds_lock
);
4281 spin_lock_init(&memcg
->move_lock
);
4282 vmpressure_init(&memcg
->vmpressure
);
4283 INIT_LIST_HEAD(&memcg
->event_list
);
4284 spin_lock_init(&memcg
->event_list_lock
);
4285 #ifdef CONFIG_MEMCG_KMEM
4286 memcg
->kmemcg_id
= -1;
4288 #ifdef CONFIG_CGROUP_WRITEBACK
4289 INIT_LIST_HEAD(&memcg
->cgwb_list
);
4294 __mem_cgroup_free(memcg
);
4295 return ERR_PTR(error
);
4299 mem_cgroup_css_online(struct cgroup_subsys_state
*css
)
4301 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
4302 struct mem_cgroup
*parent
= mem_cgroup_from_css(css
->parent
);
4305 if (css
->id
> MEM_CGROUP_ID_MAX
)
4311 mutex_lock(&memcg_create_mutex
);
4313 memcg
->use_hierarchy
= parent
->use_hierarchy
;
4314 memcg
->oom_kill_disable
= parent
->oom_kill_disable
;
4315 memcg
->swappiness
= mem_cgroup_swappiness(parent
);
4317 if (parent
->use_hierarchy
) {
4318 page_counter_init(&memcg
->memory
, &parent
->memory
);
4319 memcg
->high
= PAGE_COUNTER_MAX
;
4320 memcg
->soft_limit
= PAGE_COUNTER_MAX
;
4321 page_counter_init(&memcg
->memsw
, &parent
->memsw
);
4322 page_counter_init(&memcg
->kmem
, &parent
->kmem
);
4325 * No need to take a reference to the parent because cgroup
4326 * core guarantees its existence.
4329 page_counter_init(&memcg
->memory
, NULL
);
4330 memcg
->high
= PAGE_COUNTER_MAX
;
4331 memcg
->soft_limit
= PAGE_COUNTER_MAX
;
4332 page_counter_init(&memcg
->memsw
, NULL
);
4333 page_counter_init(&memcg
->kmem
, NULL
);
4335 * Deeper hierachy with use_hierarchy == false doesn't make
4336 * much sense so let cgroup subsystem know about this
4337 * unfortunate state in our controller.
4339 if (parent
!= root_mem_cgroup
)
4340 memory_cgrp_subsys
.broken_hierarchy
= true;
4342 mutex_unlock(&memcg_create_mutex
);
4344 ret
= memcg_init_kmem(memcg
, &memory_cgrp_subsys
);
4349 * Make sure the memcg is initialized: mem_cgroup_iter()
4350 * orders reading memcg->initialized against its callers
4351 * reading the memcg members.
4353 smp_store_release(&memcg
->initialized
, 1);
4358 static void mem_cgroup_css_offline(struct cgroup_subsys_state
*css
)
4360 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
4361 struct mem_cgroup_event
*event
, *tmp
;
4364 * Unregister events and notify userspace.
4365 * Notify userspace about cgroup removing only after rmdir of cgroup
4366 * directory to avoid race between userspace and kernelspace.
4368 spin_lock(&memcg
->event_list_lock
);
4369 list_for_each_entry_safe(event
, tmp
, &memcg
->event_list
, list
) {
4370 list_del_init(&event
->list
);
4371 schedule_work(&event
->remove
);
4373 spin_unlock(&memcg
->event_list_lock
);
4375 vmpressure_cleanup(&memcg
->vmpressure
);
4377 memcg_deactivate_kmem(memcg
);
4379 wb_memcg_offline(memcg
);
4382 static void mem_cgroup_css_released(struct cgroup_subsys_state
*css
)
4384 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
4386 invalidate_reclaim_iterators(memcg
);
4389 static void mem_cgroup_css_free(struct cgroup_subsys_state
*css
)
4391 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
4393 memcg_destroy_kmem(memcg
);
4394 __mem_cgroup_free(memcg
);
4398 * mem_cgroup_css_reset - reset the states of a mem_cgroup
4399 * @css: the target css
4401 * Reset the states of the mem_cgroup associated with @css. This is
4402 * invoked when the userland requests disabling on the default hierarchy
4403 * but the memcg is pinned through dependency. The memcg should stop
4404 * applying policies and should revert to the vanilla state as it may be
4405 * made visible again.
4407 * The current implementation only resets the essential configurations.
4408 * This needs to be expanded to cover all the visible parts.
4410 static void mem_cgroup_css_reset(struct cgroup_subsys_state
*css
)
4412 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
4414 mem_cgroup_resize_limit(memcg
, PAGE_COUNTER_MAX
);
4415 mem_cgroup_resize_memsw_limit(memcg
, PAGE_COUNTER_MAX
);
4416 memcg_update_kmem_limit(memcg
, PAGE_COUNTER_MAX
);
4418 memcg
->high
= PAGE_COUNTER_MAX
;
4419 memcg
->soft_limit
= PAGE_COUNTER_MAX
;
4420 memcg_wb_domain_size_changed(memcg
);
4424 /* Handlers for move charge at task migration. */
4425 static int mem_cgroup_do_precharge(unsigned long count
)
4429 /* Try a single bulk charge without reclaim first, kswapd may wake */
4430 ret
= try_charge(mc
.to
, GFP_KERNEL
& ~__GFP_DIRECT_RECLAIM
, count
);
4432 mc
.precharge
+= count
;
4436 /* Try charges one by one with reclaim */
4438 ret
= try_charge(mc
.to
, GFP_KERNEL
& ~__GFP_NORETRY
, 1);
4448 * get_mctgt_type - get target type of moving charge
4449 * @vma: the vma the pte to be checked belongs
4450 * @addr: the address corresponding to the pte to be checked
4451 * @ptent: the pte to be checked
4452 * @target: the pointer the target page or swap ent will be stored(can be NULL)
4455 * 0(MC_TARGET_NONE): if the pte is not a target for move charge.
4456 * 1(MC_TARGET_PAGE): if the page corresponding to this pte is a target for
4457 * move charge. if @target is not NULL, the page is stored in target->page
4458 * with extra refcnt got(Callers should handle it).
4459 * 2(MC_TARGET_SWAP): if the swap entry corresponding to this pte is a
4460 * target for charge migration. if @target is not NULL, the entry is stored
4463 * Called with pte lock held.
4470 enum mc_target_type
{
4476 static struct page
*mc_handle_present_pte(struct vm_area_struct
*vma
,
4477 unsigned long addr
, pte_t ptent
)
4479 struct page
*page
= vm_normal_page(vma
, addr
, ptent
);
4481 if (!page
|| !page_mapped(page
))
4483 if (PageAnon(page
)) {
4484 if (!(mc
.flags
& MOVE_ANON
))
4487 if (!(mc
.flags
& MOVE_FILE
))
4490 if (!get_page_unless_zero(page
))
4497 static struct page
*mc_handle_swap_pte(struct vm_area_struct
*vma
,
4498 unsigned long addr
, pte_t ptent
, swp_entry_t
*entry
)
4500 struct page
*page
= NULL
;
4501 swp_entry_t ent
= pte_to_swp_entry(ptent
);
4503 if (!(mc
.flags
& MOVE_ANON
) || non_swap_entry(ent
))
4506 * Because lookup_swap_cache() updates some statistics counter,
4507 * we call find_get_page() with swapper_space directly.
4509 page
= find_get_page(swap_address_space(ent
), ent
.val
);
4510 if (do_swap_account
)
4511 entry
->val
= ent
.val
;
4516 static struct page
*mc_handle_swap_pte(struct vm_area_struct
*vma
,
4517 unsigned long addr
, pte_t ptent
, swp_entry_t
*entry
)
4523 static struct page
*mc_handle_file_pte(struct vm_area_struct
*vma
,
4524 unsigned long addr
, pte_t ptent
, swp_entry_t
*entry
)
4526 struct page
*page
= NULL
;
4527 struct address_space
*mapping
;
4530 if (!vma
->vm_file
) /* anonymous vma */
4532 if (!(mc
.flags
& MOVE_FILE
))
4535 mapping
= vma
->vm_file
->f_mapping
;
4536 pgoff
= linear_page_index(vma
, addr
);
4538 /* page is moved even if it's not RSS of this task(page-faulted). */
4540 /* shmem/tmpfs may report page out on swap: account for that too. */
4541 if (shmem_mapping(mapping
)) {
4542 page
= find_get_entry(mapping
, pgoff
);
4543 if (radix_tree_exceptional_entry(page
)) {
4544 swp_entry_t swp
= radix_to_swp_entry(page
);
4545 if (do_swap_account
)
4547 page
= find_get_page(swap_address_space(swp
), swp
.val
);
4550 page
= find_get_page(mapping
, pgoff
);
4552 page
= find_get_page(mapping
, pgoff
);
4558 * mem_cgroup_move_account - move account of the page
4560 * @nr_pages: number of regular pages (>1 for huge pages)
4561 * @from: mem_cgroup which the page is moved from.
4562 * @to: mem_cgroup which the page is moved to. @from != @to.
4564 * The caller must confirm following.
4565 * - page is not on LRU (isolate_page() is useful.)
4566 * - compound_lock is held when nr_pages > 1
4568 * This function doesn't do "charge" to new cgroup and doesn't do "uncharge"
4571 static int mem_cgroup_move_account(struct page
*page
,
4572 unsigned int nr_pages
,
4573 struct mem_cgroup
*from
,
4574 struct mem_cgroup
*to
)
4576 unsigned long flags
;
4580 VM_BUG_ON(from
== to
);
4581 VM_BUG_ON_PAGE(PageLRU(page
), page
);
4583 * The page is isolated from LRU. So, collapse function
4584 * will not handle this page. But page splitting can happen.
4585 * Do this check under compound_page_lock(). The caller should
4589 if (nr_pages
> 1 && !PageTransHuge(page
))
4593 * Prevent mem_cgroup_replace_page() from looking at
4594 * page->mem_cgroup of its source page while we change it.
4596 if (!trylock_page(page
))
4600 if (page
->mem_cgroup
!= from
)
4603 anon
= PageAnon(page
);
4605 spin_lock_irqsave(&from
->move_lock
, flags
);
4607 if (!anon
&& page_mapped(page
)) {
4608 __this_cpu_sub(from
->stat
->count
[MEM_CGROUP_STAT_FILE_MAPPED
],
4610 __this_cpu_add(to
->stat
->count
[MEM_CGROUP_STAT_FILE_MAPPED
],
4615 * move_lock grabbed above and caller set from->moving_account, so
4616 * mem_cgroup_update_page_stat() will serialize updates to PageDirty.
4617 * So mapping should be stable for dirty pages.
4619 if (!anon
&& PageDirty(page
)) {
4620 struct address_space
*mapping
= page_mapping(page
);
4622 if (mapping_cap_account_dirty(mapping
)) {
4623 __this_cpu_sub(from
->stat
->count
[MEM_CGROUP_STAT_DIRTY
],
4625 __this_cpu_add(to
->stat
->count
[MEM_CGROUP_STAT_DIRTY
],
4630 if (PageWriteback(page
)) {
4631 __this_cpu_sub(from
->stat
->count
[MEM_CGROUP_STAT_WRITEBACK
],
4633 __this_cpu_add(to
->stat
->count
[MEM_CGROUP_STAT_WRITEBACK
],
4638 * It is safe to change page->mem_cgroup here because the page
4639 * is referenced, charged, and isolated - we can't race with
4640 * uncharging, charging, migration, or LRU putback.
4643 /* caller should have done css_get */
4644 page
->mem_cgroup
= to
;
4645 spin_unlock_irqrestore(&from
->move_lock
, flags
);
4649 local_irq_disable();
4650 mem_cgroup_charge_statistics(to
, page
, nr_pages
);
4651 memcg_check_events(to
, page
);
4652 mem_cgroup_charge_statistics(from
, page
, -nr_pages
);
4653 memcg_check_events(from
, page
);
4661 static enum mc_target_type
get_mctgt_type(struct vm_area_struct
*vma
,
4662 unsigned long addr
, pte_t ptent
, union mc_target
*target
)
4664 struct page
*page
= NULL
;
4665 enum mc_target_type ret
= MC_TARGET_NONE
;
4666 swp_entry_t ent
= { .val
= 0 };
4668 if (pte_present(ptent
))
4669 page
= mc_handle_present_pte(vma
, addr
, ptent
);
4670 else if (is_swap_pte(ptent
))
4671 page
= mc_handle_swap_pte(vma
, addr
, ptent
, &ent
);
4672 else if (pte_none(ptent
))
4673 page
= mc_handle_file_pte(vma
, addr
, ptent
, &ent
);
4675 if (!page
&& !ent
.val
)
4679 * Do only loose check w/o serialization.
4680 * mem_cgroup_move_account() checks the page is valid or
4681 * not under LRU exclusion.
4683 if (page
->mem_cgroup
== mc
.from
) {
4684 ret
= MC_TARGET_PAGE
;
4686 target
->page
= page
;
4688 if (!ret
|| !target
)
4691 /* There is a swap entry and a page doesn't exist or isn't charged */
4692 if (ent
.val
&& !ret
&&
4693 mem_cgroup_id(mc
.from
) == lookup_swap_cgroup_id(ent
)) {
4694 ret
= MC_TARGET_SWAP
;
4701 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
4703 * We don't consider swapping or file mapped pages because THP does not
4704 * support them for now.
4705 * Caller should make sure that pmd_trans_huge(pmd) is true.
4707 static enum mc_target_type
get_mctgt_type_thp(struct vm_area_struct
*vma
,
4708 unsigned long addr
, pmd_t pmd
, union mc_target
*target
)
4710 struct page
*page
= NULL
;
4711 enum mc_target_type ret
= MC_TARGET_NONE
;
4713 page
= pmd_page(pmd
);
4714 VM_BUG_ON_PAGE(!page
|| !PageHead(page
), page
);
4715 if (!(mc
.flags
& MOVE_ANON
))
4717 if (page
->mem_cgroup
== mc
.from
) {
4718 ret
= MC_TARGET_PAGE
;
4721 target
->page
= page
;
4727 static inline enum mc_target_type
get_mctgt_type_thp(struct vm_area_struct
*vma
,
4728 unsigned long addr
, pmd_t pmd
, union mc_target
*target
)
4730 return MC_TARGET_NONE
;
4734 static int mem_cgroup_count_precharge_pte_range(pmd_t
*pmd
,
4735 unsigned long addr
, unsigned long end
,
4736 struct mm_walk
*walk
)
4738 struct vm_area_struct
*vma
= walk
->vma
;
4742 if (pmd_trans_huge_lock(pmd
, vma
, &ptl
) == 1) {
4743 if (get_mctgt_type_thp(vma
, addr
, *pmd
, NULL
) == MC_TARGET_PAGE
)
4744 mc
.precharge
+= HPAGE_PMD_NR
;
4749 if (pmd_trans_unstable(pmd
))
4751 pte
= pte_offset_map_lock(vma
->vm_mm
, pmd
, addr
, &ptl
);
4752 for (; addr
!= end
; pte
++, addr
+= PAGE_SIZE
)
4753 if (get_mctgt_type(vma
, addr
, *pte
, NULL
))
4754 mc
.precharge
++; /* increment precharge temporarily */
4755 pte_unmap_unlock(pte
- 1, ptl
);
4761 static unsigned long mem_cgroup_count_precharge(struct mm_struct
*mm
)
4763 unsigned long precharge
;
4765 struct mm_walk mem_cgroup_count_precharge_walk
= {
4766 .pmd_entry
= mem_cgroup_count_precharge_pte_range
,
4769 down_read(&mm
->mmap_sem
);
4770 walk_page_range(0, ~0UL, &mem_cgroup_count_precharge_walk
);
4771 up_read(&mm
->mmap_sem
);
4773 precharge
= mc
.precharge
;
4779 static int mem_cgroup_precharge_mc(struct mm_struct
*mm
)
4781 unsigned long precharge
= mem_cgroup_count_precharge(mm
);
4783 VM_BUG_ON(mc
.moving_task
);
4784 mc
.moving_task
= current
;
4785 return mem_cgroup_do_precharge(precharge
);
4788 /* cancels all extra charges on mc.from and mc.to, and wakes up all waiters. */
4789 static void __mem_cgroup_clear_mc(void)
4791 struct mem_cgroup
*from
= mc
.from
;
4792 struct mem_cgroup
*to
= mc
.to
;
4794 /* we must uncharge all the leftover precharges from mc.to */
4796 cancel_charge(mc
.to
, mc
.precharge
);
4800 * we didn't uncharge from mc.from at mem_cgroup_move_account(), so
4801 * we must uncharge here.
4803 if (mc
.moved_charge
) {
4804 cancel_charge(mc
.from
, mc
.moved_charge
);
4805 mc
.moved_charge
= 0;
4807 /* we must fixup refcnts and charges */
4808 if (mc
.moved_swap
) {
4809 /* uncharge swap account from the old cgroup */
4810 if (!mem_cgroup_is_root(mc
.from
))
4811 page_counter_uncharge(&mc
.from
->memsw
, mc
.moved_swap
);
4814 * we charged both to->memory and to->memsw, so we
4815 * should uncharge to->memory.
4817 if (!mem_cgroup_is_root(mc
.to
))
4818 page_counter_uncharge(&mc
.to
->memory
, mc
.moved_swap
);
4820 css_put_many(&mc
.from
->css
, mc
.moved_swap
);
4822 /* we've already done css_get(mc.to) */
4825 memcg_oom_recover(from
);
4826 memcg_oom_recover(to
);
4827 wake_up_all(&mc
.waitq
);
4830 static void mem_cgroup_clear_mc(void)
4833 * we must clear moving_task before waking up waiters at the end of
4836 mc
.moving_task
= NULL
;
4837 __mem_cgroup_clear_mc();
4838 spin_lock(&mc
.lock
);
4841 spin_unlock(&mc
.lock
);
4844 static int mem_cgroup_can_attach(struct cgroup_taskset
*tset
)
4846 struct cgroup_subsys_state
*css
;
4847 struct mem_cgroup
*memcg
= NULL
; /* unneeded init to make gcc happy */
4848 struct mem_cgroup
*from
;
4849 struct task_struct
*leader
, *p
;
4850 struct mm_struct
*mm
;
4851 unsigned long move_flags
;
4854 /* charge immigration isn't supported on the default hierarchy */
4855 if (cgroup_subsys_on_dfl(memory_cgrp_subsys
))
4859 * Multi-process migrations only happen on the default hierarchy
4860 * where charge immigration is not used. Perform charge
4861 * immigration if @tset contains a leader and whine if there are
4865 cgroup_taskset_for_each_leader(leader
, css
, tset
) {
4868 memcg
= mem_cgroup_from_css(css
);
4874 * We are now commited to this value whatever it is. Changes in this
4875 * tunable will only affect upcoming migrations, not the current one.
4876 * So we need to save it, and keep it going.
4878 move_flags
= READ_ONCE(memcg
->move_charge_at_immigrate
);
4882 from
= mem_cgroup_from_task(p
);
4884 VM_BUG_ON(from
== memcg
);
4886 mm
= get_task_mm(p
);
4889 /* We move charges only when we move a owner of the mm */
4890 if (mm
->owner
== p
) {
4893 VM_BUG_ON(mc
.precharge
);
4894 VM_BUG_ON(mc
.moved_charge
);
4895 VM_BUG_ON(mc
.moved_swap
);
4897 spin_lock(&mc
.lock
);
4900 mc
.flags
= move_flags
;
4901 spin_unlock(&mc
.lock
);
4902 /* We set mc.moving_task later */
4904 ret
= mem_cgroup_precharge_mc(mm
);
4906 mem_cgroup_clear_mc();
4912 static void mem_cgroup_cancel_attach(struct cgroup_taskset
*tset
)
4915 mem_cgroup_clear_mc();
4918 static int mem_cgroup_move_charge_pte_range(pmd_t
*pmd
,
4919 unsigned long addr
, unsigned long end
,
4920 struct mm_walk
*walk
)
4923 struct vm_area_struct
*vma
= walk
->vma
;
4926 enum mc_target_type target_type
;
4927 union mc_target target
;
4931 * We don't take compound_lock() here but no race with splitting thp
4933 * - if pmd_trans_huge_lock() returns 1, the relevant thp is not
4934 * under splitting, which means there's no concurrent thp split,
4935 * - if another thread runs into split_huge_page() just after we
4936 * entered this if-block, the thread must wait for page table lock
4937 * to be unlocked in __split_huge_page_splitting(), where the main
4938 * part of thp split is not executed yet.
4940 if (pmd_trans_huge_lock(pmd
, vma
, &ptl
) == 1) {
4941 if (mc
.precharge
< HPAGE_PMD_NR
) {
4945 target_type
= get_mctgt_type_thp(vma
, addr
, *pmd
, &target
);
4946 if (target_type
== MC_TARGET_PAGE
) {
4948 if (!isolate_lru_page(page
)) {
4949 if (!mem_cgroup_move_account(page
, HPAGE_PMD_NR
,
4951 mc
.precharge
-= HPAGE_PMD_NR
;
4952 mc
.moved_charge
+= HPAGE_PMD_NR
;
4954 putback_lru_page(page
);
4962 if (pmd_trans_unstable(pmd
))
4965 pte
= pte_offset_map_lock(vma
->vm_mm
, pmd
, addr
, &ptl
);
4966 for (; addr
!= end
; addr
+= PAGE_SIZE
) {
4967 pte_t ptent
= *(pte
++);
4973 switch (get_mctgt_type(vma
, addr
, ptent
, &target
)) {
4974 case MC_TARGET_PAGE
:
4976 if (isolate_lru_page(page
))
4978 if (!mem_cgroup_move_account(page
, 1, mc
.from
, mc
.to
)) {
4980 /* we uncharge from mc.from later. */
4983 putback_lru_page(page
);
4984 put
: /* get_mctgt_type() gets the page */
4987 case MC_TARGET_SWAP
:
4989 if (!mem_cgroup_move_swap_account(ent
, mc
.from
, mc
.to
)) {
4991 /* we fixup refcnts and charges later. */
4999 pte_unmap_unlock(pte
- 1, ptl
);
5004 * We have consumed all precharges we got in can_attach().
5005 * We try charge one by one, but don't do any additional
5006 * charges to mc.to if we have failed in charge once in attach()
5009 ret
= mem_cgroup_do_precharge(1);
5017 static void mem_cgroup_move_charge(struct mm_struct
*mm
)
5019 struct mm_walk mem_cgroup_move_charge_walk
= {
5020 .pmd_entry
= mem_cgroup_move_charge_pte_range
,
5024 lru_add_drain_all();
5026 * Signal mem_cgroup_begin_page_stat() to take the memcg's
5027 * move_lock while we're moving its pages to another memcg.
5028 * Then wait for already started RCU-only updates to finish.
5030 atomic_inc(&mc
.from
->moving_account
);
5033 if (unlikely(!down_read_trylock(&mm
->mmap_sem
))) {
5035 * Someone who are holding the mmap_sem might be waiting in
5036 * waitq. So we cancel all extra charges, wake up all waiters,
5037 * and retry. Because we cancel precharges, we might not be able
5038 * to move enough charges, but moving charge is a best-effort
5039 * feature anyway, so it wouldn't be a big problem.
5041 __mem_cgroup_clear_mc();
5046 * When we have consumed all precharges and failed in doing
5047 * additional charge, the page walk just aborts.
5049 walk_page_range(0, ~0UL, &mem_cgroup_move_charge_walk
);
5050 up_read(&mm
->mmap_sem
);
5051 atomic_dec(&mc
.from
->moving_account
);
5054 static void mem_cgroup_move_task(struct cgroup_taskset
*tset
)
5056 struct cgroup_subsys_state
*css
;
5057 struct task_struct
*p
= cgroup_taskset_first(tset
, &css
);
5058 struct mm_struct
*mm
= get_task_mm(p
);
5062 mem_cgroup_move_charge(mm
);
5066 mem_cgroup_clear_mc();
5068 #else /* !CONFIG_MMU */
5069 static int mem_cgroup_can_attach(struct cgroup_taskset
*tset
)
5073 static void mem_cgroup_cancel_attach(struct cgroup_taskset
*tset
)
5076 static void mem_cgroup_move_task(struct cgroup_taskset
*tset
)
5082 * Cgroup retains root cgroups across [un]mount cycles making it necessary
5083 * to verify whether we're attached to the default hierarchy on each mount
5086 static void mem_cgroup_bind(struct cgroup_subsys_state
*root_css
)
5089 * use_hierarchy is forced on the default hierarchy. cgroup core
5090 * guarantees that @root doesn't have any children, so turning it
5091 * on for the root memcg is enough.
5093 if (cgroup_subsys_on_dfl(memory_cgrp_subsys
))
5094 root_mem_cgroup
->use_hierarchy
= true;
5096 root_mem_cgroup
->use_hierarchy
= false;
5099 static u64
memory_current_read(struct cgroup_subsys_state
*css
,
5102 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
5104 return (u64
)page_counter_read(&memcg
->memory
) * PAGE_SIZE
;
5107 static int memory_low_show(struct seq_file
*m
, void *v
)
5109 struct mem_cgroup
*memcg
= mem_cgroup_from_css(seq_css(m
));
5110 unsigned long low
= READ_ONCE(memcg
->low
);
5112 if (low
== PAGE_COUNTER_MAX
)
5113 seq_puts(m
, "max\n");
5115 seq_printf(m
, "%llu\n", (u64
)low
* PAGE_SIZE
);
5120 static ssize_t
memory_low_write(struct kernfs_open_file
*of
,
5121 char *buf
, size_t nbytes
, loff_t off
)
5123 struct mem_cgroup
*memcg
= mem_cgroup_from_css(of_css(of
));
5127 buf
= strstrip(buf
);
5128 err
= page_counter_memparse(buf
, "max", &low
);
5137 static int memory_high_show(struct seq_file
*m
, void *v
)
5139 struct mem_cgroup
*memcg
= mem_cgroup_from_css(seq_css(m
));
5140 unsigned long high
= READ_ONCE(memcg
->high
);
5142 if (high
== PAGE_COUNTER_MAX
)
5143 seq_puts(m
, "max\n");
5145 seq_printf(m
, "%llu\n", (u64
)high
* PAGE_SIZE
);
5150 static ssize_t
memory_high_write(struct kernfs_open_file
*of
,
5151 char *buf
, size_t nbytes
, loff_t off
)
5153 struct mem_cgroup
*memcg
= mem_cgroup_from_css(of_css(of
));
5157 buf
= strstrip(buf
);
5158 err
= page_counter_memparse(buf
, "max", &high
);
5164 memcg_wb_domain_size_changed(memcg
);
5168 static int memory_max_show(struct seq_file
*m
, void *v
)
5170 struct mem_cgroup
*memcg
= mem_cgroup_from_css(seq_css(m
));
5171 unsigned long max
= READ_ONCE(memcg
->memory
.limit
);
5173 if (max
== PAGE_COUNTER_MAX
)
5174 seq_puts(m
, "max\n");
5176 seq_printf(m
, "%llu\n", (u64
)max
* PAGE_SIZE
);
5181 static ssize_t
memory_max_write(struct kernfs_open_file
*of
,
5182 char *buf
, size_t nbytes
, loff_t off
)
5184 struct mem_cgroup
*memcg
= mem_cgroup_from_css(of_css(of
));
5188 buf
= strstrip(buf
);
5189 err
= page_counter_memparse(buf
, "max", &max
);
5193 err
= mem_cgroup_resize_limit(memcg
, max
);
5197 memcg_wb_domain_size_changed(memcg
);
5201 static int memory_events_show(struct seq_file
*m
, void *v
)
5203 struct mem_cgroup
*memcg
= mem_cgroup_from_css(seq_css(m
));
5205 seq_printf(m
, "low %lu\n", mem_cgroup_read_events(memcg
, MEMCG_LOW
));
5206 seq_printf(m
, "high %lu\n", mem_cgroup_read_events(memcg
, MEMCG_HIGH
));
5207 seq_printf(m
, "max %lu\n", mem_cgroup_read_events(memcg
, MEMCG_MAX
));
5208 seq_printf(m
, "oom %lu\n", mem_cgroup_read_events(memcg
, MEMCG_OOM
));
5213 static struct cftype memory_files
[] = {
5216 .flags
= CFTYPE_NOT_ON_ROOT
,
5217 .read_u64
= memory_current_read
,
5221 .flags
= CFTYPE_NOT_ON_ROOT
,
5222 .seq_show
= memory_low_show
,
5223 .write
= memory_low_write
,
5227 .flags
= CFTYPE_NOT_ON_ROOT
,
5228 .seq_show
= memory_high_show
,
5229 .write
= memory_high_write
,
5233 .flags
= CFTYPE_NOT_ON_ROOT
,
5234 .seq_show
= memory_max_show
,
5235 .write
= memory_max_write
,
5239 .flags
= CFTYPE_NOT_ON_ROOT
,
5240 .file_offset
= offsetof(struct mem_cgroup
, events_file
),
5241 .seq_show
= memory_events_show
,
5246 struct cgroup_subsys memory_cgrp_subsys
= {
5247 .css_alloc
= mem_cgroup_css_alloc
,
5248 .css_online
= mem_cgroup_css_online
,
5249 .css_offline
= mem_cgroup_css_offline
,
5250 .css_released
= mem_cgroup_css_released
,
5251 .css_free
= mem_cgroup_css_free
,
5252 .css_reset
= mem_cgroup_css_reset
,
5253 .can_attach
= mem_cgroup_can_attach
,
5254 .cancel_attach
= mem_cgroup_cancel_attach
,
5255 .attach
= mem_cgroup_move_task
,
5256 .bind
= mem_cgroup_bind
,
5257 .dfl_cftypes
= memory_files
,
5258 .legacy_cftypes
= mem_cgroup_legacy_files
,
5263 * mem_cgroup_low - check if memory consumption is below the normal range
5264 * @root: the highest ancestor to consider
5265 * @memcg: the memory cgroup to check
5267 * Returns %true if memory consumption of @memcg, and that of all
5268 * configurable ancestors up to @root, is below the normal range.
5270 bool mem_cgroup_low(struct mem_cgroup
*root
, struct mem_cgroup
*memcg
)
5272 if (mem_cgroup_disabled())
5276 * The toplevel group doesn't have a configurable range, so
5277 * it's never low when looked at directly, and it is not
5278 * considered an ancestor when assessing the hierarchy.
5281 if (memcg
== root_mem_cgroup
)
5284 if (page_counter_read(&memcg
->memory
) >= memcg
->low
)
5287 while (memcg
!= root
) {
5288 memcg
= parent_mem_cgroup(memcg
);
5290 if (memcg
== root_mem_cgroup
)
5293 if (page_counter_read(&memcg
->memory
) >= memcg
->low
)
5300 * mem_cgroup_try_charge - try charging a page
5301 * @page: page to charge
5302 * @mm: mm context of the victim
5303 * @gfp_mask: reclaim mode
5304 * @memcgp: charged memcg return
5306 * Try to charge @page to the memcg that @mm belongs to, reclaiming
5307 * pages according to @gfp_mask if necessary.
5309 * Returns 0 on success, with *@memcgp pointing to the charged memcg.
5310 * Otherwise, an error code is returned.
5312 * After page->mapping has been set up, the caller must finalize the
5313 * charge with mem_cgroup_commit_charge(). Or abort the transaction
5314 * with mem_cgroup_cancel_charge() in case page instantiation fails.
5316 int mem_cgroup_try_charge(struct page
*page
, struct mm_struct
*mm
,
5317 gfp_t gfp_mask
, struct mem_cgroup
**memcgp
)
5319 struct mem_cgroup
*memcg
= NULL
;
5320 unsigned int nr_pages
= 1;
5323 if (mem_cgroup_disabled())
5326 if (PageSwapCache(page
)) {
5328 * Every swap fault against a single page tries to charge the
5329 * page, bail as early as possible. shmem_unuse() encounters
5330 * already charged pages, too. The USED bit is protected by
5331 * the page lock, which serializes swap cache removal, which
5332 * in turn serializes uncharging.
5334 VM_BUG_ON_PAGE(!PageLocked(page
), page
);
5335 if (page
->mem_cgroup
)
5338 if (do_swap_account
) {
5339 swp_entry_t ent
= { .val
= page_private(page
), };
5340 unsigned short id
= lookup_swap_cgroup_id(ent
);
5343 memcg
= mem_cgroup_from_id(id
);
5344 if (memcg
&& !css_tryget_online(&memcg
->css
))
5350 if (PageTransHuge(page
)) {
5351 nr_pages
<<= compound_order(page
);
5352 VM_BUG_ON_PAGE(!PageTransHuge(page
), page
);
5356 memcg
= get_mem_cgroup_from_mm(mm
);
5358 ret
= try_charge(memcg
, gfp_mask
, nr_pages
);
5360 css_put(&memcg
->css
);
5367 * mem_cgroup_commit_charge - commit a page charge
5368 * @page: page to charge
5369 * @memcg: memcg to charge the page to
5370 * @lrucare: page might be on LRU already
5372 * Finalize a charge transaction started by mem_cgroup_try_charge(),
5373 * after page->mapping has been set up. This must happen atomically
5374 * as part of the page instantiation, i.e. under the page table lock
5375 * for anonymous pages, under the page lock for page and swap cache.
5377 * In addition, the page must not be on the LRU during the commit, to
5378 * prevent racing with task migration. If it might be, use @lrucare.
5380 * Use mem_cgroup_cancel_charge() to cancel the transaction instead.
5382 void mem_cgroup_commit_charge(struct page
*page
, struct mem_cgroup
*memcg
,
5385 unsigned int nr_pages
= 1;
5387 VM_BUG_ON_PAGE(!page
->mapping
, page
);
5388 VM_BUG_ON_PAGE(PageLRU(page
) && !lrucare
, page
);
5390 if (mem_cgroup_disabled())
5393 * Swap faults will attempt to charge the same page multiple
5394 * times. But reuse_swap_page() might have removed the page
5395 * from swapcache already, so we can't check PageSwapCache().
5400 commit_charge(page
, memcg
, lrucare
);
5402 if (PageTransHuge(page
)) {
5403 nr_pages
<<= compound_order(page
);
5404 VM_BUG_ON_PAGE(!PageTransHuge(page
), page
);
5407 local_irq_disable();
5408 mem_cgroup_charge_statistics(memcg
, page
, nr_pages
);
5409 memcg_check_events(memcg
, page
);
5412 if (do_swap_account
&& PageSwapCache(page
)) {
5413 swp_entry_t entry
= { .val
= page_private(page
) };
5415 * The swap entry might not get freed for a long time,
5416 * let's not wait for it. The page already received a
5417 * memory+swap charge, drop the swap entry duplicate.
5419 mem_cgroup_uncharge_swap(entry
);
5424 * mem_cgroup_cancel_charge - cancel a page charge
5425 * @page: page to charge
5426 * @memcg: memcg to charge the page to
5428 * Cancel a charge transaction started by mem_cgroup_try_charge().
5430 void mem_cgroup_cancel_charge(struct page
*page
, struct mem_cgroup
*memcg
)
5432 unsigned int nr_pages
= 1;
5434 if (mem_cgroup_disabled())
5437 * Swap faults will attempt to charge the same page multiple
5438 * times. But reuse_swap_page() might have removed the page
5439 * from swapcache already, so we can't check PageSwapCache().
5444 if (PageTransHuge(page
)) {
5445 nr_pages
<<= compound_order(page
);
5446 VM_BUG_ON_PAGE(!PageTransHuge(page
), page
);
5449 cancel_charge(memcg
, nr_pages
);
5452 static void uncharge_batch(struct mem_cgroup
*memcg
, unsigned long pgpgout
,
5453 unsigned long nr_anon
, unsigned long nr_file
,
5454 unsigned long nr_huge
, struct page
*dummy_page
)
5456 unsigned long nr_pages
= nr_anon
+ nr_file
;
5457 unsigned long flags
;
5459 if (!mem_cgroup_is_root(memcg
)) {
5460 page_counter_uncharge(&memcg
->memory
, nr_pages
);
5461 if (do_swap_account
)
5462 page_counter_uncharge(&memcg
->memsw
, nr_pages
);
5463 memcg_oom_recover(memcg
);
5466 local_irq_save(flags
);
5467 __this_cpu_sub(memcg
->stat
->count
[MEM_CGROUP_STAT_RSS
], nr_anon
);
5468 __this_cpu_sub(memcg
->stat
->count
[MEM_CGROUP_STAT_CACHE
], nr_file
);
5469 __this_cpu_sub(memcg
->stat
->count
[MEM_CGROUP_STAT_RSS_HUGE
], nr_huge
);
5470 __this_cpu_add(memcg
->stat
->events
[MEM_CGROUP_EVENTS_PGPGOUT
], pgpgout
);
5471 __this_cpu_add(memcg
->stat
->nr_page_events
, nr_pages
);
5472 memcg_check_events(memcg
, dummy_page
);
5473 local_irq_restore(flags
);
5475 if (!mem_cgroup_is_root(memcg
))
5476 css_put_many(&memcg
->css
, nr_pages
);
5479 static void uncharge_list(struct list_head
*page_list
)
5481 struct mem_cgroup
*memcg
= NULL
;
5482 unsigned long nr_anon
= 0;
5483 unsigned long nr_file
= 0;
5484 unsigned long nr_huge
= 0;
5485 unsigned long pgpgout
= 0;
5486 struct list_head
*next
;
5489 next
= page_list
->next
;
5491 unsigned int nr_pages
= 1;
5493 page
= list_entry(next
, struct page
, lru
);
5494 next
= page
->lru
.next
;
5496 VM_BUG_ON_PAGE(PageLRU(page
), page
);
5497 VM_BUG_ON_PAGE(page_count(page
), page
);
5499 if (!page
->mem_cgroup
)
5503 * Nobody should be changing or seriously looking at
5504 * page->mem_cgroup at this point, we have fully
5505 * exclusive access to the page.
5508 if (memcg
!= page
->mem_cgroup
) {
5510 uncharge_batch(memcg
, pgpgout
, nr_anon
, nr_file
,
5512 pgpgout
= nr_anon
= nr_file
= nr_huge
= 0;
5514 memcg
= page
->mem_cgroup
;
5517 if (PageTransHuge(page
)) {
5518 nr_pages
<<= compound_order(page
);
5519 VM_BUG_ON_PAGE(!PageTransHuge(page
), page
);
5520 nr_huge
+= nr_pages
;
5524 nr_anon
+= nr_pages
;
5526 nr_file
+= nr_pages
;
5528 page
->mem_cgroup
= NULL
;
5531 } while (next
!= page_list
);
5534 uncharge_batch(memcg
, pgpgout
, nr_anon
, nr_file
,
5539 * mem_cgroup_uncharge - uncharge a page
5540 * @page: page to uncharge
5542 * Uncharge a page previously charged with mem_cgroup_try_charge() and
5543 * mem_cgroup_commit_charge().
5545 void mem_cgroup_uncharge(struct page
*page
)
5547 if (mem_cgroup_disabled())
5550 /* Don't touch page->lru of any random page, pre-check: */
5551 if (!page
->mem_cgroup
)
5554 INIT_LIST_HEAD(&page
->lru
);
5555 uncharge_list(&page
->lru
);
5559 * mem_cgroup_uncharge_list - uncharge a list of page
5560 * @page_list: list of pages to uncharge
5562 * Uncharge a list of pages previously charged with
5563 * mem_cgroup_try_charge() and mem_cgroup_commit_charge().
5565 void mem_cgroup_uncharge_list(struct list_head
*page_list
)
5567 if (mem_cgroup_disabled())
5570 if (!list_empty(page_list
))
5571 uncharge_list(page_list
);
5575 * mem_cgroup_replace_page - migrate a charge to another page
5576 * @oldpage: currently charged page
5577 * @newpage: page to transfer the charge to
5579 * Migrate the charge from @oldpage to @newpage.
5581 * Both pages must be locked, @newpage->mapping must be set up.
5582 * Either or both pages might be on the LRU already.
5584 void mem_cgroup_replace_page(struct page
*oldpage
, struct page
*newpage
)
5586 struct mem_cgroup
*memcg
;
5589 VM_BUG_ON_PAGE(!PageLocked(oldpage
), oldpage
);
5590 VM_BUG_ON_PAGE(!PageLocked(newpage
), newpage
);
5591 VM_BUG_ON_PAGE(PageAnon(oldpage
) != PageAnon(newpage
), newpage
);
5592 VM_BUG_ON_PAGE(PageTransHuge(oldpage
) != PageTransHuge(newpage
),
5595 if (mem_cgroup_disabled())
5598 /* Page cache replacement: new page already charged? */
5599 if (newpage
->mem_cgroup
)
5602 /* Swapcache readahead pages can get replaced before being charged */
5603 memcg
= oldpage
->mem_cgroup
;
5607 lock_page_lru(oldpage
, &isolated
);
5608 oldpage
->mem_cgroup
= NULL
;
5609 unlock_page_lru(oldpage
, isolated
);
5611 commit_charge(newpage
, memcg
, true);
5615 * subsys_initcall() for memory controller.
5617 * Some parts like hotcpu_notifier() have to be initialized from this context
5618 * because of lock dependencies (cgroup_lock -> cpu hotplug) but basically
5619 * everything that doesn't depend on a specific mem_cgroup structure should
5620 * be initialized from here.
5622 static int __init
mem_cgroup_init(void)
5626 hotcpu_notifier(memcg_cpu_hotplug_callback
, 0);
5628 for_each_possible_cpu(cpu
)
5629 INIT_WORK(&per_cpu_ptr(&memcg_stock
, cpu
)->work
,
5632 for_each_node(node
) {
5633 struct mem_cgroup_tree_per_node
*rtpn
;
5636 rtpn
= kzalloc_node(sizeof(*rtpn
), GFP_KERNEL
,
5637 node_online(node
) ? node
: NUMA_NO_NODE
);
5639 for (zone
= 0; zone
< MAX_NR_ZONES
; zone
++) {
5640 struct mem_cgroup_tree_per_zone
*rtpz
;
5642 rtpz
= &rtpn
->rb_tree_per_zone
[zone
];
5643 rtpz
->rb_root
= RB_ROOT
;
5644 spin_lock_init(&rtpz
->lock
);
5646 soft_limit_tree
.rb_tree_per_node
[node
] = rtpn
;
5651 subsys_initcall(mem_cgroup_init
);
5653 #ifdef CONFIG_MEMCG_SWAP
5655 * mem_cgroup_swapout - transfer a memsw charge to swap
5656 * @page: page whose memsw charge to transfer
5657 * @entry: swap entry to move the charge to
5659 * Transfer the memsw charge of @page to @entry.
5661 void mem_cgroup_swapout(struct page
*page
, swp_entry_t entry
)
5663 struct mem_cgroup
*memcg
;
5664 unsigned short oldid
;
5666 VM_BUG_ON_PAGE(PageLRU(page
), page
);
5667 VM_BUG_ON_PAGE(page_count(page
), page
);
5669 if (!do_swap_account
)
5672 memcg
= page
->mem_cgroup
;
5674 /* Readahead page, never charged */
5678 oldid
= swap_cgroup_record(entry
, mem_cgroup_id(memcg
));
5679 VM_BUG_ON_PAGE(oldid
, page
);
5680 mem_cgroup_swap_statistics(memcg
, true);
5682 page
->mem_cgroup
= NULL
;
5684 if (!mem_cgroup_is_root(memcg
))
5685 page_counter_uncharge(&memcg
->memory
, 1);
5688 * Interrupts should be disabled here because the caller holds the
5689 * mapping->tree_lock lock which is taken with interrupts-off. It is
5690 * important here to have the interrupts disabled because it is the
5691 * only synchronisation we have for udpating the per-CPU variables.
5693 VM_BUG_ON(!irqs_disabled());
5694 mem_cgroup_charge_statistics(memcg
, page
, -1);
5695 memcg_check_events(memcg
, page
);
5699 * mem_cgroup_uncharge_swap - uncharge a swap entry
5700 * @entry: swap entry to uncharge
5702 * Drop the memsw charge associated with @entry.
5704 void mem_cgroup_uncharge_swap(swp_entry_t entry
)
5706 struct mem_cgroup
*memcg
;
5709 if (!do_swap_account
)
5712 id
= swap_cgroup_record(entry
, 0);
5714 memcg
= mem_cgroup_from_id(id
);
5716 if (!mem_cgroup_is_root(memcg
))
5717 page_counter_uncharge(&memcg
->memsw
, 1);
5718 mem_cgroup_swap_statistics(memcg
, false);
5719 css_put(&memcg
->css
);
5724 /* for remember boot option*/
5725 #ifdef CONFIG_MEMCG_SWAP_ENABLED
5726 static int really_do_swap_account __initdata
= 1;
5728 static int really_do_swap_account __initdata
;
5731 static int __init
enable_swap_account(char *s
)
5733 if (!strcmp(s
, "1"))
5734 really_do_swap_account
= 1;
5735 else if (!strcmp(s
, "0"))
5736 really_do_swap_account
= 0;
5739 __setup("swapaccount=", enable_swap_account
);
5741 static struct cftype memsw_cgroup_files
[] = {
5743 .name
= "memsw.usage_in_bytes",
5744 .private = MEMFILE_PRIVATE(_MEMSWAP
, RES_USAGE
),
5745 .read_u64
= mem_cgroup_read_u64
,
5748 .name
= "memsw.max_usage_in_bytes",
5749 .private = MEMFILE_PRIVATE(_MEMSWAP
, RES_MAX_USAGE
),
5750 .write
= mem_cgroup_reset
,
5751 .read_u64
= mem_cgroup_read_u64
,
5754 .name
= "memsw.limit_in_bytes",
5755 .private = MEMFILE_PRIVATE(_MEMSWAP
, RES_LIMIT
),
5756 .write
= mem_cgroup_write
,
5757 .read_u64
= mem_cgroup_read_u64
,
5760 .name
= "memsw.failcnt",
5761 .private = MEMFILE_PRIVATE(_MEMSWAP
, RES_FAILCNT
),
5762 .write
= mem_cgroup_reset
,
5763 .read_u64
= mem_cgroup_read_u64
,
5765 { }, /* terminate */
5768 static int __init
mem_cgroup_swap_init(void)
5770 if (!mem_cgroup_disabled() && really_do_swap_account
) {
5771 do_swap_account
= 1;
5772 WARN_ON(cgroup_add_legacy_cftypes(&memory_cgrp_subsys
,
5773 memsw_cgroup_files
));
5777 subsys_initcall(mem_cgroup_swap_init
);
5779 #endif /* CONFIG_MEMCG_SWAP */