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 struct static_key memcg_sockets_enabled_key
;
295 EXPORT_SYMBOL(memcg_sockets_enabled_key
);
297 void sock_update_memcg(struct sock
*sk
)
299 struct mem_cgroup
*memcg
;
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_memcg
));
311 css_get(&sk
->sk_memcg
->css
);
316 memcg
= mem_cgroup_from_task(current
);
317 if (memcg
!= root_mem_cgroup
&&
318 memcg
->tcp_mem
.active
&&
319 css_tryget_online(&memcg
->css
))
320 sk
->sk_memcg
= memcg
;
323 EXPORT_SYMBOL(sock_update_memcg
);
325 void sock_release_memcg(struct sock
*sk
)
327 WARN_ON(!sk
->sk_memcg
);
328 css_put(&sk
->sk_memcg
->css
);
332 * mem_cgroup_charge_skmem - charge socket memory
333 * @memcg: memcg to charge
334 * @nr_pages: number of pages to charge
336 * Charges @nr_pages to @memcg. Returns %true if the charge fit within
337 * @memcg's configured limit, %false if the charge had to be forced.
339 bool mem_cgroup_charge_skmem(struct mem_cgroup
*memcg
, unsigned int nr_pages
)
341 struct page_counter
*counter
;
343 if (page_counter_try_charge(&memcg
->tcp_mem
.memory_allocated
,
344 nr_pages
, &counter
)) {
345 memcg
->tcp_mem
.memory_pressure
= 0;
348 page_counter_charge(&memcg
->tcp_mem
.memory_allocated
, nr_pages
);
349 memcg
->tcp_mem
.memory_pressure
= 1;
354 * mem_cgroup_uncharge_skmem - uncharge socket memory
355 * @memcg - memcg to uncharge
356 * @nr_pages - number of pages to uncharge
358 void mem_cgroup_uncharge_skmem(struct mem_cgroup
*memcg
, unsigned int nr_pages
)
360 page_counter_uncharge(&memcg
->tcp_mem
.memory_allocated
, nr_pages
);
365 #ifdef CONFIG_MEMCG_KMEM
367 * This will be the memcg's index in each cache's ->memcg_params.memcg_caches.
368 * The main reason for not using cgroup id for this:
369 * this works better in sparse environments, where we have a lot of memcgs,
370 * but only a few kmem-limited. Or also, if we have, for instance, 200
371 * memcgs, and none but the 200th is kmem-limited, we'd have to have a
372 * 200 entry array for that.
374 * The current size of the caches array is stored in memcg_nr_cache_ids. It
375 * will double each time we have to increase it.
377 static DEFINE_IDA(memcg_cache_ida
);
378 int memcg_nr_cache_ids
;
380 /* Protects memcg_nr_cache_ids */
381 static DECLARE_RWSEM(memcg_cache_ids_sem
);
383 void memcg_get_cache_ids(void)
385 down_read(&memcg_cache_ids_sem
);
388 void memcg_put_cache_ids(void)
390 up_read(&memcg_cache_ids_sem
);
394 * MIN_SIZE is different than 1, because we would like to avoid going through
395 * the alloc/free process all the time. In a small machine, 4 kmem-limited
396 * cgroups is a reasonable guess. In the future, it could be a parameter or
397 * tunable, but that is strictly not necessary.
399 * MAX_SIZE should be as large as the number of cgrp_ids. Ideally, we could get
400 * this constant directly from cgroup, but it is understandable that this is
401 * better kept as an internal representation in cgroup.c. In any case, the
402 * cgrp_id space is not getting any smaller, and we don't have to necessarily
403 * increase ours as well if it increases.
405 #define MEMCG_CACHES_MIN_SIZE 4
406 #define MEMCG_CACHES_MAX_SIZE MEM_CGROUP_ID_MAX
409 * A lot of the calls to the cache allocation functions are expected to be
410 * inlined by the compiler. Since the calls to memcg_kmem_get_cache are
411 * conditional to this static branch, we'll have to allow modules that does
412 * kmem_cache_alloc and the such to see this symbol as well
414 struct static_key memcg_kmem_enabled_key
;
415 EXPORT_SYMBOL(memcg_kmem_enabled_key
);
417 #endif /* CONFIG_MEMCG_KMEM */
419 static struct mem_cgroup_per_zone
*
420 mem_cgroup_zone_zoneinfo(struct mem_cgroup
*memcg
, struct zone
*zone
)
422 int nid
= zone_to_nid(zone
);
423 int zid
= zone_idx(zone
);
425 return &memcg
->nodeinfo
[nid
]->zoneinfo
[zid
];
429 * mem_cgroup_css_from_page - css of the memcg associated with a page
430 * @page: page of interest
432 * If memcg is bound to the default hierarchy, css of the memcg associated
433 * with @page is returned. The returned css remains associated with @page
434 * until it is released.
436 * If memcg is bound to a traditional hierarchy, the css of root_mem_cgroup
439 * XXX: The above description of behavior on the default hierarchy isn't
440 * strictly true yet as replace_page_cache_page() can modify the
441 * association before @page is released even on the default hierarchy;
442 * however, the current and planned usages don't mix the the two functions
443 * and replace_page_cache_page() will soon be updated to make the invariant
446 struct cgroup_subsys_state
*mem_cgroup_css_from_page(struct page
*page
)
448 struct mem_cgroup
*memcg
;
452 memcg
= page
->mem_cgroup
;
454 if (!memcg
|| !cgroup_subsys_on_dfl(memory_cgrp_subsys
))
455 memcg
= root_mem_cgroup
;
462 * page_cgroup_ino - return inode number of the memcg a page is charged to
465 * Look up the closest online ancestor of the memory cgroup @page is charged to
466 * and return its inode number or 0 if @page is not charged to any cgroup. It
467 * is safe to call this function without holding a reference to @page.
469 * Note, this function is inherently racy, because there is nothing to prevent
470 * the cgroup inode from getting torn down and potentially reallocated a moment
471 * after page_cgroup_ino() returns, so it only should be used by callers that
472 * do not care (such as procfs interfaces).
474 ino_t
page_cgroup_ino(struct page
*page
)
476 struct mem_cgroup
*memcg
;
477 unsigned long ino
= 0;
480 memcg
= READ_ONCE(page
->mem_cgroup
);
481 while (memcg
&& !(memcg
->css
.flags
& CSS_ONLINE
))
482 memcg
= parent_mem_cgroup(memcg
);
484 ino
= cgroup_ino(memcg
->css
.cgroup
);
489 static struct mem_cgroup_per_zone
*
490 mem_cgroup_page_zoneinfo(struct mem_cgroup
*memcg
, struct page
*page
)
492 int nid
= page_to_nid(page
);
493 int zid
= page_zonenum(page
);
495 return &memcg
->nodeinfo
[nid
]->zoneinfo
[zid
];
498 static struct mem_cgroup_tree_per_zone
*
499 soft_limit_tree_node_zone(int nid
, int zid
)
501 return &soft_limit_tree
.rb_tree_per_node
[nid
]->rb_tree_per_zone
[zid
];
504 static struct mem_cgroup_tree_per_zone
*
505 soft_limit_tree_from_page(struct page
*page
)
507 int nid
= page_to_nid(page
);
508 int zid
= page_zonenum(page
);
510 return &soft_limit_tree
.rb_tree_per_node
[nid
]->rb_tree_per_zone
[zid
];
513 static void __mem_cgroup_insert_exceeded(struct mem_cgroup_per_zone
*mz
,
514 struct mem_cgroup_tree_per_zone
*mctz
,
515 unsigned long new_usage_in_excess
)
517 struct rb_node
**p
= &mctz
->rb_root
.rb_node
;
518 struct rb_node
*parent
= NULL
;
519 struct mem_cgroup_per_zone
*mz_node
;
524 mz
->usage_in_excess
= new_usage_in_excess
;
525 if (!mz
->usage_in_excess
)
529 mz_node
= rb_entry(parent
, struct mem_cgroup_per_zone
,
531 if (mz
->usage_in_excess
< mz_node
->usage_in_excess
)
534 * We can't avoid mem cgroups that are over their soft
535 * limit by the same amount
537 else if (mz
->usage_in_excess
>= mz_node
->usage_in_excess
)
540 rb_link_node(&mz
->tree_node
, parent
, p
);
541 rb_insert_color(&mz
->tree_node
, &mctz
->rb_root
);
545 static void __mem_cgroup_remove_exceeded(struct mem_cgroup_per_zone
*mz
,
546 struct mem_cgroup_tree_per_zone
*mctz
)
550 rb_erase(&mz
->tree_node
, &mctz
->rb_root
);
554 static void mem_cgroup_remove_exceeded(struct mem_cgroup_per_zone
*mz
,
555 struct mem_cgroup_tree_per_zone
*mctz
)
559 spin_lock_irqsave(&mctz
->lock
, flags
);
560 __mem_cgroup_remove_exceeded(mz
, mctz
);
561 spin_unlock_irqrestore(&mctz
->lock
, flags
);
564 static unsigned long soft_limit_excess(struct mem_cgroup
*memcg
)
566 unsigned long nr_pages
= page_counter_read(&memcg
->memory
);
567 unsigned long soft_limit
= READ_ONCE(memcg
->soft_limit
);
568 unsigned long excess
= 0;
570 if (nr_pages
> soft_limit
)
571 excess
= nr_pages
- soft_limit
;
576 static void mem_cgroup_update_tree(struct mem_cgroup
*memcg
, struct page
*page
)
578 unsigned long excess
;
579 struct mem_cgroup_per_zone
*mz
;
580 struct mem_cgroup_tree_per_zone
*mctz
;
582 mctz
= soft_limit_tree_from_page(page
);
584 * Necessary to update all ancestors when hierarchy is used.
585 * because their event counter is not touched.
587 for (; memcg
; memcg
= parent_mem_cgroup(memcg
)) {
588 mz
= mem_cgroup_page_zoneinfo(memcg
, page
);
589 excess
= soft_limit_excess(memcg
);
591 * We have to update the tree if mz is on RB-tree or
592 * mem is over its softlimit.
594 if (excess
|| mz
->on_tree
) {
597 spin_lock_irqsave(&mctz
->lock
, flags
);
598 /* if on-tree, remove it */
600 __mem_cgroup_remove_exceeded(mz
, mctz
);
602 * Insert again. mz->usage_in_excess will be updated.
603 * If excess is 0, no tree ops.
605 __mem_cgroup_insert_exceeded(mz
, mctz
, excess
);
606 spin_unlock_irqrestore(&mctz
->lock
, flags
);
611 static void mem_cgroup_remove_from_trees(struct mem_cgroup
*memcg
)
613 struct mem_cgroup_tree_per_zone
*mctz
;
614 struct mem_cgroup_per_zone
*mz
;
618 for (zid
= 0; zid
< MAX_NR_ZONES
; zid
++) {
619 mz
= &memcg
->nodeinfo
[nid
]->zoneinfo
[zid
];
620 mctz
= soft_limit_tree_node_zone(nid
, zid
);
621 mem_cgroup_remove_exceeded(mz
, mctz
);
626 static struct mem_cgroup_per_zone
*
627 __mem_cgroup_largest_soft_limit_node(struct mem_cgroup_tree_per_zone
*mctz
)
629 struct rb_node
*rightmost
= NULL
;
630 struct mem_cgroup_per_zone
*mz
;
634 rightmost
= rb_last(&mctz
->rb_root
);
636 goto done
; /* Nothing to reclaim from */
638 mz
= rb_entry(rightmost
, struct mem_cgroup_per_zone
, tree_node
);
640 * Remove the node now but someone else can add it back,
641 * we will to add it back at the end of reclaim to its correct
642 * position in the tree.
644 __mem_cgroup_remove_exceeded(mz
, mctz
);
645 if (!soft_limit_excess(mz
->memcg
) ||
646 !css_tryget_online(&mz
->memcg
->css
))
652 static struct mem_cgroup_per_zone
*
653 mem_cgroup_largest_soft_limit_node(struct mem_cgroup_tree_per_zone
*mctz
)
655 struct mem_cgroup_per_zone
*mz
;
657 spin_lock_irq(&mctz
->lock
);
658 mz
= __mem_cgroup_largest_soft_limit_node(mctz
);
659 spin_unlock_irq(&mctz
->lock
);
664 * Return page count for single (non recursive) @memcg.
666 * Implementation Note: reading percpu statistics for memcg.
668 * Both of vmstat[] and percpu_counter has threshold and do periodic
669 * synchronization to implement "quick" read. There are trade-off between
670 * reading cost and precision of value. Then, we may have a chance to implement
671 * a periodic synchronization of counter in memcg's counter.
673 * But this _read() function is used for user interface now. The user accounts
674 * memory usage by memory cgroup and he _always_ requires exact value because
675 * he accounts memory. Even if we provide quick-and-fuzzy read, we always
676 * have to visit all online cpus and make sum. So, for now, unnecessary
677 * synchronization is not implemented. (just implemented for cpu hotplug)
679 * If there are kernel internal actions which can make use of some not-exact
680 * value, and reading all cpu value can be performance bottleneck in some
681 * common workload, threshold and synchronization as vmstat[] should be
685 mem_cgroup_read_stat(struct mem_cgroup
*memcg
, enum mem_cgroup_stat_index idx
)
690 /* Per-cpu values can be negative, use a signed accumulator */
691 for_each_possible_cpu(cpu
)
692 val
+= per_cpu(memcg
->stat
->count
[idx
], cpu
);
694 * Summing races with updates, so val may be negative. Avoid exposing
695 * transient negative values.
702 static unsigned long mem_cgroup_read_events(struct mem_cgroup
*memcg
,
703 enum mem_cgroup_events_index idx
)
705 unsigned long val
= 0;
708 for_each_possible_cpu(cpu
)
709 val
+= per_cpu(memcg
->stat
->events
[idx
], cpu
);
713 static void mem_cgroup_charge_statistics(struct mem_cgroup
*memcg
,
718 * Here, RSS means 'mapped anon' and anon's SwapCache. Shmem/tmpfs is
719 * counted as CACHE even if it's on ANON LRU.
722 __this_cpu_add(memcg
->stat
->count
[MEM_CGROUP_STAT_RSS
],
725 __this_cpu_add(memcg
->stat
->count
[MEM_CGROUP_STAT_CACHE
],
728 if (PageTransHuge(page
))
729 __this_cpu_add(memcg
->stat
->count
[MEM_CGROUP_STAT_RSS_HUGE
],
732 /* pagein of a big page is an event. So, ignore page size */
734 __this_cpu_inc(memcg
->stat
->events
[MEM_CGROUP_EVENTS_PGPGIN
]);
736 __this_cpu_inc(memcg
->stat
->events
[MEM_CGROUP_EVENTS_PGPGOUT
]);
737 nr_pages
= -nr_pages
; /* for event */
740 __this_cpu_add(memcg
->stat
->nr_page_events
, nr_pages
);
743 static unsigned long mem_cgroup_node_nr_lru_pages(struct mem_cgroup
*memcg
,
745 unsigned int lru_mask
)
747 unsigned long nr
= 0;
750 VM_BUG_ON((unsigned)nid
>= nr_node_ids
);
752 for (zid
= 0; zid
< MAX_NR_ZONES
; zid
++) {
753 struct mem_cgroup_per_zone
*mz
;
757 if (!(BIT(lru
) & lru_mask
))
759 mz
= &memcg
->nodeinfo
[nid
]->zoneinfo
[zid
];
760 nr
+= mz
->lru_size
[lru
];
766 static unsigned long mem_cgroup_nr_lru_pages(struct mem_cgroup
*memcg
,
767 unsigned int lru_mask
)
769 unsigned long nr
= 0;
772 for_each_node_state(nid
, N_MEMORY
)
773 nr
+= mem_cgroup_node_nr_lru_pages(memcg
, nid
, lru_mask
);
777 static bool mem_cgroup_event_ratelimit(struct mem_cgroup
*memcg
,
778 enum mem_cgroup_events_target target
)
780 unsigned long val
, next
;
782 val
= __this_cpu_read(memcg
->stat
->nr_page_events
);
783 next
= __this_cpu_read(memcg
->stat
->targets
[target
]);
784 /* from time_after() in jiffies.h */
785 if ((long)next
- (long)val
< 0) {
787 case MEM_CGROUP_TARGET_THRESH
:
788 next
= val
+ THRESHOLDS_EVENTS_TARGET
;
790 case MEM_CGROUP_TARGET_SOFTLIMIT
:
791 next
= val
+ SOFTLIMIT_EVENTS_TARGET
;
793 case MEM_CGROUP_TARGET_NUMAINFO
:
794 next
= val
+ NUMAINFO_EVENTS_TARGET
;
799 __this_cpu_write(memcg
->stat
->targets
[target
], next
);
806 * Check events in order.
809 static void memcg_check_events(struct mem_cgroup
*memcg
, struct page
*page
)
811 /* threshold event is triggered in finer grain than soft limit */
812 if (unlikely(mem_cgroup_event_ratelimit(memcg
,
813 MEM_CGROUP_TARGET_THRESH
))) {
815 bool do_numainfo __maybe_unused
;
817 do_softlimit
= mem_cgroup_event_ratelimit(memcg
,
818 MEM_CGROUP_TARGET_SOFTLIMIT
);
820 do_numainfo
= mem_cgroup_event_ratelimit(memcg
,
821 MEM_CGROUP_TARGET_NUMAINFO
);
823 mem_cgroup_threshold(memcg
);
824 if (unlikely(do_softlimit
))
825 mem_cgroup_update_tree(memcg
, page
);
827 if (unlikely(do_numainfo
))
828 atomic_inc(&memcg
->numainfo_events
);
833 struct mem_cgroup
*mem_cgroup_from_task(struct task_struct
*p
)
836 * mm_update_next_owner() may clear mm->owner to NULL
837 * if it races with swapoff, page migration, etc.
838 * So this can be called with p == NULL.
843 return mem_cgroup_from_css(task_css(p
, memory_cgrp_id
));
845 EXPORT_SYMBOL(mem_cgroup_from_task
);
847 static struct mem_cgroup
*get_mem_cgroup_from_mm(struct mm_struct
*mm
)
849 struct mem_cgroup
*memcg
= NULL
;
854 * Page cache insertions can happen withou an
855 * actual mm context, e.g. during disk probing
856 * on boot, loopback IO, acct() writes etc.
859 memcg
= root_mem_cgroup
;
861 memcg
= mem_cgroup_from_task(rcu_dereference(mm
->owner
));
862 if (unlikely(!memcg
))
863 memcg
= root_mem_cgroup
;
865 } while (!css_tryget_online(&memcg
->css
));
871 * mem_cgroup_iter - iterate over memory cgroup hierarchy
872 * @root: hierarchy root
873 * @prev: previously returned memcg, NULL on first invocation
874 * @reclaim: cookie for shared reclaim walks, NULL for full walks
876 * Returns references to children of the hierarchy below @root, or
877 * @root itself, or %NULL after a full round-trip.
879 * Caller must pass the return value in @prev on subsequent
880 * invocations for reference counting, or use mem_cgroup_iter_break()
881 * to cancel a hierarchy walk before the round-trip is complete.
883 * Reclaimers can specify a zone and a priority level in @reclaim to
884 * divide up the memcgs in the hierarchy among all concurrent
885 * reclaimers operating on the same zone and priority.
887 struct mem_cgroup
*mem_cgroup_iter(struct mem_cgroup
*root
,
888 struct mem_cgroup
*prev
,
889 struct mem_cgroup_reclaim_cookie
*reclaim
)
891 struct mem_cgroup_reclaim_iter
*uninitialized_var(iter
);
892 struct cgroup_subsys_state
*css
= NULL
;
893 struct mem_cgroup
*memcg
= NULL
;
894 struct mem_cgroup
*pos
= NULL
;
896 if (mem_cgroup_disabled())
900 root
= root_mem_cgroup
;
902 if (prev
&& !reclaim
)
905 if (!root
->use_hierarchy
&& root
!= root_mem_cgroup
) {
914 struct mem_cgroup_per_zone
*mz
;
916 mz
= mem_cgroup_zone_zoneinfo(root
, reclaim
->zone
);
917 iter
= &mz
->iter
[reclaim
->priority
];
919 if (prev
&& reclaim
->generation
!= iter
->generation
)
923 pos
= READ_ONCE(iter
->position
);
924 if (!pos
|| css_tryget(&pos
->css
))
927 * css reference reached zero, so iter->position will
928 * be cleared by ->css_released. However, we should not
929 * rely on this happening soon, because ->css_released
930 * is called from a work queue, and by busy-waiting we
931 * might block it. So we clear iter->position right
934 (void)cmpxchg(&iter
->position
, pos
, NULL
);
942 css
= css_next_descendant_pre(css
, &root
->css
);
945 * Reclaimers share the hierarchy walk, and a
946 * new one might jump in right at the end of
947 * the hierarchy - make sure they see at least
948 * one group and restart from the beginning.
956 * Verify the css and acquire a reference. The root
957 * is provided by the caller, so we know it's alive
958 * and kicking, and don't take an extra reference.
960 memcg
= mem_cgroup_from_css(css
);
962 if (css
== &root
->css
)
965 if (css_tryget(css
)) {
967 * Make sure the memcg is initialized:
968 * mem_cgroup_css_online() orders the the
969 * initialization against setting the flag.
971 if (smp_load_acquire(&memcg
->initialized
))
982 * The position could have already been updated by a competing
983 * thread, so check that the value hasn't changed since we read
984 * it to avoid reclaiming from the same cgroup twice.
986 (void)cmpxchg(&iter
->position
, pos
, memcg
);
994 reclaim
->generation
= iter
->generation
;
1000 if (prev
&& prev
!= root
)
1001 css_put(&prev
->css
);
1007 * mem_cgroup_iter_break - abort a hierarchy walk prematurely
1008 * @root: hierarchy root
1009 * @prev: last visited hierarchy member as returned by mem_cgroup_iter()
1011 void mem_cgroup_iter_break(struct mem_cgroup
*root
,
1012 struct mem_cgroup
*prev
)
1015 root
= root_mem_cgroup
;
1016 if (prev
&& prev
!= root
)
1017 css_put(&prev
->css
);
1020 static void invalidate_reclaim_iterators(struct mem_cgroup
*dead_memcg
)
1022 struct mem_cgroup
*memcg
= dead_memcg
;
1023 struct mem_cgroup_reclaim_iter
*iter
;
1024 struct mem_cgroup_per_zone
*mz
;
1028 while ((memcg
= parent_mem_cgroup(memcg
))) {
1029 for_each_node(nid
) {
1030 for (zid
= 0; zid
< MAX_NR_ZONES
; zid
++) {
1031 mz
= &memcg
->nodeinfo
[nid
]->zoneinfo
[zid
];
1032 for (i
= 0; i
<= DEF_PRIORITY
; i
++) {
1033 iter
= &mz
->iter
[i
];
1034 cmpxchg(&iter
->position
,
1043 * Iteration constructs for visiting all cgroups (under a tree). If
1044 * loops are exited prematurely (break), mem_cgroup_iter_break() must
1045 * be used for reference counting.
1047 #define for_each_mem_cgroup_tree(iter, root) \
1048 for (iter = mem_cgroup_iter(root, NULL, NULL); \
1050 iter = mem_cgroup_iter(root, iter, NULL))
1052 #define for_each_mem_cgroup(iter) \
1053 for (iter = mem_cgroup_iter(NULL, NULL, NULL); \
1055 iter = mem_cgroup_iter(NULL, iter, NULL))
1058 * mem_cgroup_zone_lruvec - get the lru list vector for a zone and memcg
1059 * @zone: zone of the wanted lruvec
1060 * @memcg: memcg of the wanted lruvec
1062 * Returns the lru list vector holding pages for the given @zone and
1063 * @mem. This can be the global zone lruvec, if the memory controller
1066 struct lruvec
*mem_cgroup_zone_lruvec(struct zone
*zone
,
1067 struct mem_cgroup
*memcg
)
1069 struct mem_cgroup_per_zone
*mz
;
1070 struct lruvec
*lruvec
;
1072 if (mem_cgroup_disabled()) {
1073 lruvec
= &zone
->lruvec
;
1077 mz
= mem_cgroup_zone_zoneinfo(memcg
, zone
);
1078 lruvec
= &mz
->lruvec
;
1081 * Since a node can be onlined after the mem_cgroup was created,
1082 * we have to be prepared to initialize lruvec->zone here;
1083 * and if offlined then reonlined, we need to reinitialize it.
1085 if (unlikely(lruvec
->zone
!= zone
))
1086 lruvec
->zone
= zone
;
1091 * mem_cgroup_page_lruvec - return lruvec for isolating/putting an LRU page
1093 * @zone: zone of the page
1095 * This function is only safe when following the LRU page isolation
1096 * and putback protocol: the LRU lock must be held, and the page must
1097 * either be PageLRU() or the caller must have isolated/allocated it.
1099 struct lruvec
*mem_cgroup_page_lruvec(struct page
*page
, struct zone
*zone
)
1101 struct mem_cgroup_per_zone
*mz
;
1102 struct mem_cgroup
*memcg
;
1103 struct lruvec
*lruvec
;
1105 if (mem_cgroup_disabled()) {
1106 lruvec
= &zone
->lruvec
;
1110 memcg
= page
->mem_cgroup
;
1112 * Swapcache readahead pages are added to the LRU - and
1113 * possibly migrated - before they are charged.
1116 memcg
= root_mem_cgroup
;
1118 mz
= mem_cgroup_page_zoneinfo(memcg
, page
);
1119 lruvec
= &mz
->lruvec
;
1122 * Since a node can be onlined after the mem_cgroup was created,
1123 * we have to be prepared to initialize lruvec->zone here;
1124 * and if offlined then reonlined, we need to reinitialize it.
1126 if (unlikely(lruvec
->zone
!= zone
))
1127 lruvec
->zone
= zone
;
1132 * mem_cgroup_update_lru_size - account for adding or removing an lru page
1133 * @lruvec: mem_cgroup per zone lru vector
1134 * @lru: index of lru list the page is sitting on
1135 * @nr_pages: positive when adding or negative when removing
1137 * This function must be called when a page is added to or removed from an
1140 void mem_cgroup_update_lru_size(struct lruvec
*lruvec
, enum lru_list lru
,
1143 struct mem_cgroup_per_zone
*mz
;
1144 unsigned long *lru_size
;
1146 if (mem_cgroup_disabled())
1149 mz
= container_of(lruvec
, struct mem_cgroup_per_zone
, lruvec
);
1150 lru_size
= mz
->lru_size
+ lru
;
1151 *lru_size
+= nr_pages
;
1152 VM_BUG_ON((long)(*lru_size
) < 0);
1155 bool task_in_mem_cgroup(struct task_struct
*task
, struct mem_cgroup
*memcg
)
1157 struct mem_cgroup
*task_memcg
;
1158 struct task_struct
*p
;
1161 p
= find_lock_task_mm(task
);
1163 task_memcg
= get_mem_cgroup_from_mm(p
->mm
);
1167 * All threads may have already detached their mm's, but the oom
1168 * killer still needs to detect if they have already been oom
1169 * killed to prevent needlessly killing additional tasks.
1172 task_memcg
= mem_cgroup_from_task(task
);
1173 css_get(&task_memcg
->css
);
1176 ret
= mem_cgroup_is_descendant(task_memcg
, memcg
);
1177 css_put(&task_memcg
->css
);
1181 #define mem_cgroup_from_counter(counter, member) \
1182 container_of(counter, struct mem_cgroup, member)
1185 * mem_cgroup_margin - calculate chargeable space of a memory cgroup
1186 * @memcg: the memory cgroup
1188 * Returns the maximum amount of memory @mem can be charged with, in
1191 static unsigned long mem_cgroup_margin(struct mem_cgroup
*memcg
)
1193 unsigned long margin
= 0;
1194 unsigned long count
;
1195 unsigned long limit
;
1197 count
= page_counter_read(&memcg
->memory
);
1198 limit
= READ_ONCE(memcg
->memory
.limit
);
1200 margin
= limit
- count
;
1202 if (do_swap_account
) {
1203 count
= page_counter_read(&memcg
->memsw
);
1204 limit
= READ_ONCE(memcg
->memsw
.limit
);
1206 margin
= min(margin
, limit
- count
);
1213 * A routine for checking "mem" is under move_account() or not.
1215 * Checking a cgroup is mc.from or mc.to or under hierarchy of
1216 * moving cgroups. This is for waiting at high-memory pressure
1219 static bool mem_cgroup_under_move(struct mem_cgroup
*memcg
)
1221 struct mem_cgroup
*from
;
1222 struct mem_cgroup
*to
;
1225 * Unlike task_move routines, we access mc.to, mc.from not under
1226 * mutual exclusion by cgroup_mutex. Here, we take spinlock instead.
1228 spin_lock(&mc
.lock
);
1234 ret
= mem_cgroup_is_descendant(from
, memcg
) ||
1235 mem_cgroup_is_descendant(to
, memcg
);
1237 spin_unlock(&mc
.lock
);
1241 static bool mem_cgroup_wait_acct_move(struct mem_cgroup
*memcg
)
1243 if (mc
.moving_task
&& current
!= mc
.moving_task
) {
1244 if (mem_cgroup_under_move(memcg
)) {
1246 prepare_to_wait(&mc
.waitq
, &wait
, TASK_INTERRUPTIBLE
);
1247 /* moving charge context might have finished. */
1250 finish_wait(&mc
.waitq
, &wait
);
1257 #define K(x) ((x) << (PAGE_SHIFT-10))
1259 * mem_cgroup_print_oom_info: Print OOM information relevant to memory controller.
1260 * @memcg: The memory cgroup that went over limit
1261 * @p: Task that is going to be killed
1263 * NOTE: @memcg and @p's mem_cgroup can be different when hierarchy is
1266 void mem_cgroup_print_oom_info(struct mem_cgroup
*memcg
, struct task_struct
*p
)
1268 /* oom_info_lock ensures that parallel ooms do not interleave */
1269 static DEFINE_MUTEX(oom_info_lock
);
1270 struct mem_cgroup
*iter
;
1273 mutex_lock(&oom_info_lock
);
1277 pr_info("Task in ");
1278 pr_cont_cgroup_path(task_cgroup(p
, memory_cgrp_id
));
1279 pr_cont(" killed as a result of limit of ");
1281 pr_info("Memory limit reached of cgroup ");
1284 pr_cont_cgroup_path(memcg
->css
.cgroup
);
1289 pr_info("memory: usage %llukB, limit %llukB, failcnt %lu\n",
1290 K((u64
)page_counter_read(&memcg
->memory
)),
1291 K((u64
)memcg
->memory
.limit
), memcg
->memory
.failcnt
);
1292 pr_info("memory+swap: usage %llukB, limit %llukB, failcnt %lu\n",
1293 K((u64
)page_counter_read(&memcg
->memsw
)),
1294 K((u64
)memcg
->memsw
.limit
), memcg
->memsw
.failcnt
);
1295 pr_info("kmem: usage %llukB, limit %llukB, failcnt %lu\n",
1296 K((u64
)page_counter_read(&memcg
->kmem
)),
1297 K((u64
)memcg
->kmem
.limit
), memcg
->kmem
.failcnt
);
1299 for_each_mem_cgroup_tree(iter
, memcg
) {
1300 pr_info("Memory cgroup stats for ");
1301 pr_cont_cgroup_path(iter
->css
.cgroup
);
1304 for (i
= 0; i
< MEM_CGROUP_STAT_NSTATS
; i
++) {
1305 if (i
== MEM_CGROUP_STAT_SWAP
&& !do_swap_account
)
1307 pr_cont(" %s:%luKB", mem_cgroup_stat_names
[i
],
1308 K(mem_cgroup_read_stat(iter
, i
)));
1311 for (i
= 0; i
< NR_LRU_LISTS
; i
++)
1312 pr_cont(" %s:%luKB", mem_cgroup_lru_names
[i
],
1313 K(mem_cgroup_nr_lru_pages(iter
, BIT(i
))));
1317 mutex_unlock(&oom_info_lock
);
1321 * This function returns the number of memcg under hierarchy tree. Returns
1322 * 1(self count) if no children.
1324 static int mem_cgroup_count_children(struct mem_cgroup
*memcg
)
1327 struct mem_cgroup
*iter
;
1329 for_each_mem_cgroup_tree(iter
, memcg
)
1335 * Return the memory (and swap, if configured) limit for a memcg.
1337 static unsigned long mem_cgroup_get_limit(struct mem_cgroup
*memcg
)
1339 unsigned long limit
;
1341 limit
= memcg
->memory
.limit
;
1342 if (mem_cgroup_swappiness(memcg
)) {
1343 unsigned long memsw_limit
;
1345 memsw_limit
= memcg
->memsw
.limit
;
1346 limit
= min(limit
+ total_swap_pages
, memsw_limit
);
1351 static void mem_cgroup_out_of_memory(struct mem_cgroup
*memcg
, gfp_t gfp_mask
,
1354 struct oom_control oc
= {
1357 .gfp_mask
= gfp_mask
,
1360 struct mem_cgroup
*iter
;
1361 unsigned long chosen_points
= 0;
1362 unsigned long totalpages
;
1363 unsigned int points
= 0;
1364 struct task_struct
*chosen
= NULL
;
1366 mutex_lock(&oom_lock
);
1369 * If current has a pending SIGKILL or is exiting, then automatically
1370 * select it. The goal is to allow it to allocate so that it may
1371 * quickly exit and free its memory.
1373 if (fatal_signal_pending(current
) || task_will_free_mem(current
)) {
1374 mark_oom_victim(current
);
1378 check_panic_on_oom(&oc
, CONSTRAINT_MEMCG
, memcg
);
1379 totalpages
= mem_cgroup_get_limit(memcg
) ? : 1;
1380 for_each_mem_cgroup_tree(iter
, memcg
) {
1381 struct css_task_iter it
;
1382 struct task_struct
*task
;
1384 css_task_iter_start(&iter
->css
, &it
);
1385 while ((task
= css_task_iter_next(&it
))) {
1386 switch (oom_scan_process_thread(&oc
, task
, totalpages
)) {
1387 case OOM_SCAN_SELECT
:
1389 put_task_struct(chosen
);
1391 chosen_points
= ULONG_MAX
;
1392 get_task_struct(chosen
);
1394 case OOM_SCAN_CONTINUE
:
1396 case OOM_SCAN_ABORT
:
1397 css_task_iter_end(&it
);
1398 mem_cgroup_iter_break(memcg
, iter
);
1400 put_task_struct(chosen
);
1405 points
= oom_badness(task
, memcg
, NULL
, totalpages
);
1406 if (!points
|| points
< chosen_points
)
1408 /* Prefer thread group leaders for display purposes */
1409 if (points
== chosen_points
&&
1410 thread_group_leader(chosen
))
1414 put_task_struct(chosen
);
1416 chosen_points
= points
;
1417 get_task_struct(chosen
);
1419 css_task_iter_end(&it
);
1423 points
= chosen_points
* 1000 / totalpages
;
1424 oom_kill_process(&oc
, chosen
, points
, totalpages
, memcg
,
1425 "Memory cgroup out of memory");
1428 mutex_unlock(&oom_lock
);
1431 #if MAX_NUMNODES > 1
1434 * test_mem_cgroup_node_reclaimable
1435 * @memcg: the target memcg
1436 * @nid: the node ID to be checked.
1437 * @noswap : specify true here if the user wants flle only information.
1439 * This function returns whether the specified memcg contains any
1440 * reclaimable pages on a node. Returns true if there are any reclaimable
1441 * pages in the node.
1443 static bool test_mem_cgroup_node_reclaimable(struct mem_cgroup
*memcg
,
1444 int nid
, bool noswap
)
1446 if (mem_cgroup_node_nr_lru_pages(memcg
, nid
, LRU_ALL_FILE
))
1448 if (noswap
|| !total_swap_pages
)
1450 if (mem_cgroup_node_nr_lru_pages(memcg
, nid
, LRU_ALL_ANON
))
1457 * Always updating the nodemask is not very good - even if we have an empty
1458 * list or the wrong list here, we can start from some node and traverse all
1459 * nodes based on the zonelist. So update the list loosely once per 10 secs.
1462 static void mem_cgroup_may_update_nodemask(struct mem_cgroup
*memcg
)
1466 * numainfo_events > 0 means there was at least NUMAINFO_EVENTS_TARGET
1467 * pagein/pageout changes since the last update.
1469 if (!atomic_read(&memcg
->numainfo_events
))
1471 if (atomic_inc_return(&memcg
->numainfo_updating
) > 1)
1474 /* make a nodemask where this memcg uses memory from */
1475 memcg
->scan_nodes
= node_states
[N_MEMORY
];
1477 for_each_node_mask(nid
, node_states
[N_MEMORY
]) {
1479 if (!test_mem_cgroup_node_reclaimable(memcg
, nid
, false))
1480 node_clear(nid
, memcg
->scan_nodes
);
1483 atomic_set(&memcg
->numainfo_events
, 0);
1484 atomic_set(&memcg
->numainfo_updating
, 0);
1488 * Selecting a node where we start reclaim from. Because what we need is just
1489 * reducing usage counter, start from anywhere is O,K. Considering
1490 * memory reclaim from current node, there are pros. and cons.
1492 * Freeing memory from current node means freeing memory from a node which
1493 * we'll use or we've used. So, it may make LRU bad. And if several threads
1494 * hit limits, it will see a contention on a node. But freeing from remote
1495 * node means more costs for memory reclaim because of memory latency.
1497 * Now, we use round-robin. Better algorithm is welcomed.
1499 int mem_cgroup_select_victim_node(struct mem_cgroup
*memcg
)
1503 mem_cgroup_may_update_nodemask(memcg
);
1504 node
= memcg
->last_scanned_node
;
1506 node
= next_node(node
, memcg
->scan_nodes
);
1507 if (node
== MAX_NUMNODES
)
1508 node
= first_node(memcg
->scan_nodes
);
1510 * We call this when we hit limit, not when pages are added to LRU.
1511 * No LRU may hold pages because all pages are UNEVICTABLE or
1512 * memcg is too small and all pages are not on LRU. In that case,
1513 * we use curret node.
1515 if (unlikely(node
== MAX_NUMNODES
))
1516 node
= numa_node_id();
1518 memcg
->last_scanned_node
= node
;
1522 int mem_cgroup_select_victim_node(struct mem_cgroup
*memcg
)
1528 static int mem_cgroup_soft_reclaim(struct mem_cgroup
*root_memcg
,
1531 unsigned long *total_scanned
)
1533 struct mem_cgroup
*victim
= NULL
;
1536 unsigned long excess
;
1537 unsigned long nr_scanned
;
1538 struct mem_cgroup_reclaim_cookie reclaim
= {
1543 excess
= soft_limit_excess(root_memcg
);
1546 victim
= mem_cgroup_iter(root_memcg
, victim
, &reclaim
);
1551 * If we have not been able to reclaim
1552 * anything, it might because there are
1553 * no reclaimable pages under this hierarchy
1558 * We want to do more targeted reclaim.
1559 * excess >> 2 is not to excessive so as to
1560 * reclaim too much, nor too less that we keep
1561 * coming back to reclaim from this cgroup
1563 if (total
>= (excess
>> 2) ||
1564 (loop
> MEM_CGROUP_MAX_RECLAIM_LOOPS
))
1569 total
+= mem_cgroup_shrink_node_zone(victim
, gfp_mask
, false,
1571 *total_scanned
+= nr_scanned
;
1572 if (!soft_limit_excess(root_memcg
))
1575 mem_cgroup_iter_break(root_memcg
, victim
);
1579 #ifdef CONFIG_LOCKDEP
1580 static struct lockdep_map memcg_oom_lock_dep_map
= {
1581 .name
= "memcg_oom_lock",
1585 static DEFINE_SPINLOCK(memcg_oom_lock
);
1588 * Check OOM-Killer is already running under our hierarchy.
1589 * If someone is running, return false.
1591 static bool mem_cgroup_oom_trylock(struct mem_cgroup
*memcg
)
1593 struct mem_cgroup
*iter
, *failed
= NULL
;
1595 spin_lock(&memcg_oom_lock
);
1597 for_each_mem_cgroup_tree(iter
, memcg
) {
1598 if (iter
->oom_lock
) {
1600 * this subtree of our hierarchy is already locked
1601 * so we cannot give a lock.
1604 mem_cgroup_iter_break(memcg
, iter
);
1607 iter
->oom_lock
= true;
1612 * OK, we failed to lock the whole subtree so we have
1613 * to clean up what we set up to the failing subtree
1615 for_each_mem_cgroup_tree(iter
, memcg
) {
1616 if (iter
== failed
) {
1617 mem_cgroup_iter_break(memcg
, iter
);
1620 iter
->oom_lock
= false;
1623 mutex_acquire(&memcg_oom_lock_dep_map
, 0, 1, _RET_IP_
);
1625 spin_unlock(&memcg_oom_lock
);
1630 static void mem_cgroup_oom_unlock(struct mem_cgroup
*memcg
)
1632 struct mem_cgroup
*iter
;
1634 spin_lock(&memcg_oom_lock
);
1635 mutex_release(&memcg_oom_lock_dep_map
, 1, _RET_IP_
);
1636 for_each_mem_cgroup_tree(iter
, memcg
)
1637 iter
->oom_lock
= false;
1638 spin_unlock(&memcg_oom_lock
);
1641 static void mem_cgroup_mark_under_oom(struct mem_cgroup
*memcg
)
1643 struct mem_cgroup
*iter
;
1645 spin_lock(&memcg_oom_lock
);
1646 for_each_mem_cgroup_tree(iter
, memcg
)
1648 spin_unlock(&memcg_oom_lock
);
1651 static void mem_cgroup_unmark_under_oom(struct mem_cgroup
*memcg
)
1653 struct mem_cgroup
*iter
;
1656 * When a new child is created while the hierarchy is under oom,
1657 * mem_cgroup_oom_lock() may not be called. Watch for underflow.
1659 spin_lock(&memcg_oom_lock
);
1660 for_each_mem_cgroup_tree(iter
, memcg
)
1661 if (iter
->under_oom
> 0)
1663 spin_unlock(&memcg_oom_lock
);
1666 static DECLARE_WAIT_QUEUE_HEAD(memcg_oom_waitq
);
1668 struct oom_wait_info
{
1669 struct mem_cgroup
*memcg
;
1673 static int memcg_oom_wake_function(wait_queue_t
*wait
,
1674 unsigned mode
, int sync
, void *arg
)
1676 struct mem_cgroup
*wake_memcg
= (struct mem_cgroup
*)arg
;
1677 struct mem_cgroup
*oom_wait_memcg
;
1678 struct oom_wait_info
*oom_wait_info
;
1680 oom_wait_info
= container_of(wait
, struct oom_wait_info
, wait
);
1681 oom_wait_memcg
= oom_wait_info
->memcg
;
1683 if (!mem_cgroup_is_descendant(wake_memcg
, oom_wait_memcg
) &&
1684 !mem_cgroup_is_descendant(oom_wait_memcg
, wake_memcg
))
1686 return autoremove_wake_function(wait
, mode
, sync
, arg
);
1689 static void memcg_oom_recover(struct mem_cgroup
*memcg
)
1692 * For the following lockless ->under_oom test, the only required
1693 * guarantee is that it must see the state asserted by an OOM when
1694 * this function is called as a result of userland actions
1695 * triggered by the notification of the OOM. This is trivially
1696 * achieved by invoking mem_cgroup_mark_under_oom() before
1697 * triggering notification.
1699 if (memcg
&& memcg
->under_oom
)
1700 __wake_up(&memcg_oom_waitq
, TASK_NORMAL
, 0, memcg
);
1703 static void mem_cgroup_oom(struct mem_cgroup
*memcg
, gfp_t mask
, int order
)
1705 if (!current
->memcg_may_oom
)
1708 * We are in the middle of the charge context here, so we
1709 * don't want to block when potentially sitting on a callstack
1710 * that holds all kinds of filesystem and mm locks.
1712 * Also, the caller may handle a failed allocation gracefully
1713 * (like optional page cache readahead) and so an OOM killer
1714 * invocation might not even be necessary.
1716 * That's why we don't do anything here except remember the
1717 * OOM context and then deal with it at the end of the page
1718 * fault when the stack is unwound, the locks are released,
1719 * and when we know whether the fault was overall successful.
1721 css_get(&memcg
->css
);
1722 current
->memcg_in_oom
= memcg
;
1723 current
->memcg_oom_gfp_mask
= mask
;
1724 current
->memcg_oom_order
= order
;
1728 * mem_cgroup_oom_synchronize - complete memcg OOM handling
1729 * @handle: actually kill/wait or just clean up the OOM state
1731 * This has to be called at the end of a page fault if the memcg OOM
1732 * handler was enabled.
1734 * Memcg supports userspace OOM handling where failed allocations must
1735 * sleep on a waitqueue until the userspace task resolves the
1736 * situation. Sleeping directly in the charge context with all kinds
1737 * of locks held is not a good idea, instead we remember an OOM state
1738 * in the task and mem_cgroup_oom_synchronize() has to be called at
1739 * the end of the page fault to complete the OOM handling.
1741 * Returns %true if an ongoing memcg OOM situation was detected and
1742 * completed, %false otherwise.
1744 bool mem_cgroup_oom_synchronize(bool handle
)
1746 struct mem_cgroup
*memcg
= current
->memcg_in_oom
;
1747 struct oom_wait_info owait
;
1750 /* OOM is global, do not handle */
1754 if (!handle
|| oom_killer_disabled
)
1757 owait
.memcg
= memcg
;
1758 owait
.wait
.flags
= 0;
1759 owait
.wait
.func
= memcg_oom_wake_function
;
1760 owait
.wait
.private = current
;
1761 INIT_LIST_HEAD(&owait
.wait
.task_list
);
1763 prepare_to_wait(&memcg_oom_waitq
, &owait
.wait
, TASK_KILLABLE
);
1764 mem_cgroup_mark_under_oom(memcg
);
1766 locked
= mem_cgroup_oom_trylock(memcg
);
1769 mem_cgroup_oom_notify(memcg
);
1771 if (locked
&& !memcg
->oom_kill_disable
) {
1772 mem_cgroup_unmark_under_oom(memcg
);
1773 finish_wait(&memcg_oom_waitq
, &owait
.wait
);
1774 mem_cgroup_out_of_memory(memcg
, current
->memcg_oom_gfp_mask
,
1775 current
->memcg_oom_order
);
1778 mem_cgroup_unmark_under_oom(memcg
);
1779 finish_wait(&memcg_oom_waitq
, &owait
.wait
);
1783 mem_cgroup_oom_unlock(memcg
);
1785 * There is no guarantee that an OOM-lock contender
1786 * sees the wakeups triggered by the OOM kill
1787 * uncharges. Wake any sleepers explicitely.
1789 memcg_oom_recover(memcg
);
1792 current
->memcg_in_oom
= NULL
;
1793 css_put(&memcg
->css
);
1798 * mem_cgroup_begin_page_stat - begin a page state statistics transaction
1799 * @page: page that is going to change accounted state
1801 * This function must mark the beginning of an accounted page state
1802 * change to prevent double accounting when the page is concurrently
1803 * being moved to another memcg:
1805 * memcg = mem_cgroup_begin_page_stat(page);
1806 * if (TestClearPageState(page))
1807 * mem_cgroup_update_page_stat(memcg, state, -1);
1808 * mem_cgroup_end_page_stat(memcg);
1810 struct mem_cgroup
*mem_cgroup_begin_page_stat(struct page
*page
)
1812 struct mem_cgroup
*memcg
;
1813 unsigned long flags
;
1816 * The RCU lock is held throughout the transaction. The fast
1817 * path can get away without acquiring the memcg->move_lock
1818 * because page moving starts with an RCU grace period.
1820 * The RCU lock also protects the memcg from being freed when
1821 * the page state that is going to change is the only thing
1822 * preventing the page from being uncharged.
1823 * E.g. end-writeback clearing PageWriteback(), which allows
1824 * migration to go ahead and uncharge the page before the
1825 * account transaction might be complete.
1829 if (mem_cgroup_disabled())
1832 memcg
= page
->mem_cgroup
;
1833 if (unlikely(!memcg
))
1836 if (atomic_read(&memcg
->moving_account
) <= 0)
1839 spin_lock_irqsave(&memcg
->move_lock
, flags
);
1840 if (memcg
!= page
->mem_cgroup
) {
1841 spin_unlock_irqrestore(&memcg
->move_lock
, flags
);
1846 * When charge migration first begins, we can have locked and
1847 * unlocked page stat updates happening concurrently. Track
1848 * the task who has the lock for mem_cgroup_end_page_stat().
1850 memcg
->move_lock_task
= current
;
1851 memcg
->move_lock_flags
= flags
;
1855 EXPORT_SYMBOL(mem_cgroup_begin_page_stat
);
1858 * mem_cgroup_end_page_stat - finish a page state statistics transaction
1859 * @memcg: the memcg that was accounted against
1861 void mem_cgroup_end_page_stat(struct mem_cgroup
*memcg
)
1863 if (memcg
&& memcg
->move_lock_task
== current
) {
1864 unsigned long flags
= memcg
->move_lock_flags
;
1866 memcg
->move_lock_task
= NULL
;
1867 memcg
->move_lock_flags
= 0;
1869 spin_unlock_irqrestore(&memcg
->move_lock
, flags
);
1874 EXPORT_SYMBOL(mem_cgroup_end_page_stat
);
1877 * size of first charge trial. "32" comes from vmscan.c's magic value.
1878 * TODO: maybe necessary to use big numbers in big irons.
1880 #define CHARGE_BATCH 32U
1881 struct memcg_stock_pcp
{
1882 struct mem_cgroup
*cached
; /* this never be root cgroup */
1883 unsigned int nr_pages
;
1884 struct work_struct work
;
1885 unsigned long flags
;
1886 #define FLUSHING_CACHED_CHARGE 0
1888 static DEFINE_PER_CPU(struct memcg_stock_pcp
, memcg_stock
);
1889 static DEFINE_MUTEX(percpu_charge_mutex
);
1892 * consume_stock: Try to consume stocked charge on this cpu.
1893 * @memcg: memcg to consume from.
1894 * @nr_pages: how many pages to charge.
1896 * The charges will only happen if @memcg matches the current cpu's memcg
1897 * stock, and at least @nr_pages are available in that stock. Failure to
1898 * service an allocation will refill the stock.
1900 * returns true if successful, false otherwise.
1902 static bool consume_stock(struct mem_cgroup
*memcg
, unsigned int nr_pages
)
1904 struct memcg_stock_pcp
*stock
;
1907 if (nr_pages
> CHARGE_BATCH
)
1910 stock
= &get_cpu_var(memcg_stock
);
1911 if (memcg
== stock
->cached
&& stock
->nr_pages
>= nr_pages
) {
1912 stock
->nr_pages
-= nr_pages
;
1915 put_cpu_var(memcg_stock
);
1920 * Returns stocks cached in percpu and reset cached information.
1922 static void drain_stock(struct memcg_stock_pcp
*stock
)
1924 struct mem_cgroup
*old
= stock
->cached
;
1926 if (stock
->nr_pages
) {
1927 page_counter_uncharge(&old
->memory
, stock
->nr_pages
);
1928 if (do_swap_account
)
1929 page_counter_uncharge(&old
->memsw
, stock
->nr_pages
);
1930 css_put_many(&old
->css
, stock
->nr_pages
);
1931 stock
->nr_pages
= 0;
1933 stock
->cached
= NULL
;
1937 * This must be called under preempt disabled or must be called by
1938 * a thread which is pinned to local cpu.
1940 static void drain_local_stock(struct work_struct
*dummy
)
1942 struct memcg_stock_pcp
*stock
= this_cpu_ptr(&memcg_stock
);
1944 clear_bit(FLUSHING_CACHED_CHARGE
, &stock
->flags
);
1948 * Cache charges(val) to local per_cpu area.
1949 * This will be consumed by consume_stock() function, later.
1951 static void refill_stock(struct mem_cgroup
*memcg
, unsigned int nr_pages
)
1953 struct memcg_stock_pcp
*stock
= &get_cpu_var(memcg_stock
);
1955 if (stock
->cached
!= memcg
) { /* reset if necessary */
1957 stock
->cached
= memcg
;
1959 stock
->nr_pages
+= nr_pages
;
1960 put_cpu_var(memcg_stock
);
1964 * Drains all per-CPU charge caches for given root_memcg resp. subtree
1965 * of the hierarchy under it.
1967 static void drain_all_stock(struct mem_cgroup
*root_memcg
)
1971 /* If someone's already draining, avoid adding running more workers. */
1972 if (!mutex_trylock(&percpu_charge_mutex
))
1974 /* Notify other cpus that system-wide "drain" is running */
1977 for_each_online_cpu(cpu
) {
1978 struct memcg_stock_pcp
*stock
= &per_cpu(memcg_stock
, cpu
);
1979 struct mem_cgroup
*memcg
;
1981 memcg
= stock
->cached
;
1982 if (!memcg
|| !stock
->nr_pages
)
1984 if (!mem_cgroup_is_descendant(memcg
, root_memcg
))
1986 if (!test_and_set_bit(FLUSHING_CACHED_CHARGE
, &stock
->flags
)) {
1988 drain_local_stock(&stock
->work
);
1990 schedule_work_on(cpu
, &stock
->work
);
1995 mutex_unlock(&percpu_charge_mutex
);
1998 static int memcg_cpu_hotplug_callback(struct notifier_block
*nb
,
1999 unsigned long action
,
2002 int cpu
= (unsigned long)hcpu
;
2003 struct memcg_stock_pcp
*stock
;
2005 if (action
== CPU_ONLINE
)
2008 if (action
!= CPU_DEAD
&& action
!= CPU_DEAD_FROZEN
)
2011 stock
= &per_cpu(memcg_stock
, cpu
);
2017 * Scheduled by try_charge() to be executed from the userland return path
2018 * and reclaims memory over the high limit.
2020 void mem_cgroup_handle_over_high(void)
2022 unsigned int nr_pages
= current
->memcg_nr_pages_over_high
;
2023 struct mem_cgroup
*memcg
, *pos
;
2025 if (likely(!nr_pages
))
2028 pos
= memcg
= get_mem_cgroup_from_mm(current
->mm
);
2031 if (page_counter_read(&pos
->memory
) <= pos
->high
)
2033 mem_cgroup_events(pos
, MEMCG_HIGH
, 1);
2034 try_to_free_mem_cgroup_pages(pos
, nr_pages
, GFP_KERNEL
, true);
2035 } while ((pos
= parent_mem_cgroup(pos
)));
2037 css_put(&memcg
->css
);
2038 current
->memcg_nr_pages_over_high
= 0;
2041 static int try_charge(struct mem_cgroup
*memcg
, gfp_t gfp_mask
,
2042 unsigned int nr_pages
)
2044 unsigned int batch
= max(CHARGE_BATCH
, nr_pages
);
2045 int nr_retries
= MEM_CGROUP_RECLAIM_RETRIES
;
2046 struct mem_cgroup
*mem_over_limit
;
2047 struct page_counter
*counter
;
2048 unsigned long nr_reclaimed
;
2049 bool may_swap
= true;
2050 bool drained
= false;
2052 if (mem_cgroup_is_root(memcg
))
2055 if (consume_stock(memcg
, nr_pages
))
2058 if (!do_swap_account
||
2059 page_counter_try_charge(&memcg
->memsw
, batch
, &counter
)) {
2060 if (page_counter_try_charge(&memcg
->memory
, batch
, &counter
))
2062 if (do_swap_account
)
2063 page_counter_uncharge(&memcg
->memsw
, batch
);
2064 mem_over_limit
= mem_cgroup_from_counter(counter
, memory
);
2066 mem_over_limit
= mem_cgroup_from_counter(counter
, memsw
);
2070 if (batch
> nr_pages
) {
2076 * Unlike in global OOM situations, memcg is not in a physical
2077 * memory shortage. Allow dying and OOM-killed tasks to
2078 * bypass the last charges so that they can exit quickly and
2079 * free their memory.
2081 if (unlikely(test_thread_flag(TIF_MEMDIE
) ||
2082 fatal_signal_pending(current
) ||
2083 current
->flags
& PF_EXITING
))
2086 if (unlikely(task_in_memcg_oom(current
)))
2089 if (!gfpflags_allow_blocking(gfp_mask
))
2092 mem_cgroup_events(mem_over_limit
, MEMCG_MAX
, 1);
2094 nr_reclaimed
= try_to_free_mem_cgroup_pages(mem_over_limit
, nr_pages
,
2095 gfp_mask
, may_swap
);
2097 if (mem_cgroup_margin(mem_over_limit
) >= nr_pages
)
2101 drain_all_stock(mem_over_limit
);
2106 if (gfp_mask
& __GFP_NORETRY
)
2109 * Even though the limit is exceeded at this point, reclaim
2110 * may have been able to free some pages. Retry the charge
2111 * before killing the task.
2113 * Only for regular pages, though: huge pages are rather
2114 * unlikely to succeed so close to the limit, and we fall back
2115 * to regular pages anyway in case of failure.
2117 if (nr_reclaimed
&& nr_pages
<= (1 << PAGE_ALLOC_COSTLY_ORDER
))
2120 * At task move, charge accounts can be doubly counted. So, it's
2121 * better to wait until the end of task_move if something is going on.
2123 if (mem_cgroup_wait_acct_move(mem_over_limit
))
2129 if (gfp_mask
& __GFP_NOFAIL
)
2132 if (fatal_signal_pending(current
))
2135 mem_cgroup_events(mem_over_limit
, MEMCG_OOM
, 1);
2137 mem_cgroup_oom(mem_over_limit
, gfp_mask
,
2138 get_order(nr_pages
* PAGE_SIZE
));
2140 if (!(gfp_mask
& __GFP_NOFAIL
))
2144 * The allocation either can't fail or will lead to more memory
2145 * being freed very soon. Allow memory usage go over the limit
2146 * temporarily by force charging it.
2148 page_counter_charge(&memcg
->memory
, nr_pages
);
2149 if (do_swap_account
)
2150 page_counter_charge(&memcg
->memsw
, nr_pages
);
2151 css_get_many(&memcg
->css
, nr_pages
);
2156 css_get_many(&memcg
->css
, batch
);
2157 if (batch
> nr_pages
)
2158 refill_stock(memcg
, batch
- nr_pages
);
2161 * If the hierarchy is above the normal consumption range, schedule
2162 * reclaim on returning to userland. We can perform reclaim here
2163 * if __GFP_RECLAIM but let's always punt for simplicity and so that
2164 * GFP_KERNEL can consistently be used during reclaim. @memcg is
2165 * not recorded as it most likely matches current's and won't
2166 * change in the meantime. As high limit is checked again before
2167 * reclaim, the cost of mismatch is negligible.
2170 if (page_counter_read(&memcg
->memory
) > memcg
->high
) {
2171 current
->memcg_nr_pages_over_high
+= batch
;
2172 set_notify_resume(current
);
2175 } while ((memcg
= parent_mem_cgroup(memcg
)));
2180 static void cancel_charge(struct mem_cgroup
*memcg
, unsigned int nr_pages
)
2182 if (mem_cgroup_is_root(memcg
))
2185 page_counter_uncharge(&memcg
->memory
, nr_pages
);
2186 if (do_swap_account
)
2187 page_counter_uncharge(&memcg
->memsw
, nr_pages
);
2189 css_put_many(&memcg
->css
, nr_pages
);
2192 static void lock_page_lru(struct page
*page
, int *isolated
)
2194 struct zone
*zone
= page_zone(page
);
2196 spin_lock_irq(&zone
->lru_lock
);
2197 if (PageLRU(page
)) {
2198 struct lruvec
*lruvec
;
2200 lruvec
= mem_cgroup_page_lruvec(page
, zone
);
2202 del_page_from_lru_list(page
, lruvec
, page_lru(page
));
2208 static void unlock_page_lru(struct page
*page
, int isolated
)
2210 struct zone
*zone
= page_zone(page
);
2213 struct lruvec
*lruvec
;
2215 lruvec
= mem_cgroup_page_lruvec(page
, zone
);
2216 VM_BUG_ON_PAGE(PageLRU(page
), page
);
2218 add_page_to_lru_list(page
, lruvec
, page_lru(page
));
2220 spin_unlock_irq(&zone
->lru_lock
);
2223 static void commit_charge(struct page
*page
, struct mem_cgroup
*memcg
,
2228 VM_BUG_ON_PAGE(page
->mem_cgroup
, page
);
2231 * In some cases, SwapCache and FUSE(splice_buf->radixtree), the page
2232 * may already be on some other mem_cgroup's LRU. Take care of it.
2235 lock_page_lru(page
, &isolated
);
2238 * Nobody should be changing or seriously looking at
2239 * page->mem_cgroup at this point:
2241 * - the page is uncharged
2243 * - the page is off-LRU
2245 * - an anonymous fault has exclusive page access, except for
2246 * a locked page table
2248 * - a page cache insertion, a swapin fault, or a migration
2249 * have the page locked
2251 page
->mem_cgroup
= memcg
;
2254 unlock_page_lru(page
, isolated
);
2257 #ifdef CONFIG_MEMCG_KMEM
2258 static int memcg_alloc_cache_id(void)
2263 id
= ida_simple_get(&memcg_cache_ida
,
2264 0, MEMCG_CACHES_MAX_SIZE
, GFP_KERNEL
);
2268 if (id
< memcg_nr_cache_ids
)
2272 * There's no space for the new id in memcg_caches arrays,
2273 * so we have to grow them.
2275 down_write(&memcg_cache_ids_sem
);
2277 size
= 2 * (id
+ 1);
2278 if (size
< MEMCG_CACHES_MIN_SIZE
)
2279 size
= MEMCG_CACHES_MIN_SIZE
;
2280 else if (size
> MEMCG_CACHES_MAX_SIZE
)
2281 size
= MEMCG_CACHES_MAX_SIZE
;
2283 err
= memcg_update_all_caches(size
);
2285 err
= memcg_update_all_list_lrus(size
);
2287 memcg_nr_cache_ids
= size
;
2289 up_write(&memcg_cache_ids_sem
);
2292 ida_simple_remove(&memcg_cache_ida
, id
);
2298 static void memcg_free_cache_id(int id
)
2300 ida_simple_remove(&memcg_cache_ida
, id
);
2303 struct memcg_kmem_cache_create_work
{
2304 struct mem_cgroup
*memcg
;
2305 struct kmem_cache
*cachep
;
2306 struct work_struct work
;
2309 static void memcg_kmem_cache_create_func(struct work_struct
*w
)
2311 struct memcg_kmem_cache_create_work
*cw
=
2312 container_of(w
, struct memcg_kmem_cache_create_work
, work
);
2313 struct mem_cgroup
*memcg
= cw
->memcg
;
2314 struct kmem_cache
*cachep
= cw
->cachep
;
2316 memcg_create_kmem_cache(memcg
, cachep
);
2318 css_put(&memcg
->css
);
2323 * Enqueue the creation of a per-memcg kmem_cache.
2325 static void __memcg_schedule_kmem_cache_create(struct mem_cgroup
*memcg
,
2326 struct kmem_cache
*cachep
)
2328 struct memcg_kmem_cache_create_work
*cw
;
2330 cw
= kmalloc(sizeof(*cw
), GFP_NOWAIT
);
2334 css_get(&memcg
->css
);
2337 cw
->cachep
= cachep
;
2338 INIT_WORK(&cw
->work
, memcg_kmem_cache_create_func
);
2340 schedule_work(&cw
->work
);
2343 static void memcg_schedule_kmem_cache_create(struct mem_cgroup
*memcg
,
2344 struct kmem_cache
*cachep
)
2347 * We need to stop accounting when we kmalloc, because if the
2348 * corresponding kmalloc cache is not yet created, the first allocation
2349 * in __memcg_schedule_kmem_cache_create will recurse.
2351 * However, it is better to enclose the whole function. Depending on
2352 * the debugging options enabled, INIT_WORK(), for instance, can
2353 * trigger an allocation. This too, will make us recurse. Because at
2354 * this point we can't allow ourselves back into memcg_kmem_get_cache,
2355 * the safest choice is to do it like this, wrapping the whole function.
2357 current
->memcg_kmem_skip_account
= 1;
2358 __memcg_schedule_kmem_cache_create(memcg
, cachep
);
2359 current
->memcg_kmem_skip_account
= 0;
2363 * Return the kmem_cache we're supposed to use for a slab allocation.
2364 * We try to use the current memcg's version of the cache.
2366 * If the cache does not exist yet, if we are the first user of it,
2367 * we either create it immediately, if possible, or create it asynchronously
2369 * In the latter case, we will let the current allocation go through with
2370 * the original cache.
2372 * Can't be called in interrupt context or from kernel threads.
2373 * This function needs to be called with rcu_read_lock() held.
2375 struct kmem_cache
*__memcg_kmem_get_cache(struct kmem_cache
*cachep
, gfp_t gfp
)
2377 struct mem_cgroup
*memcg
;
2378 struct kmem_cache
*memcg_cachep
;
2381 VM_BUG_ON(!is_root_cache(cachep
));
2383 if (cachep
->flags
& SLAB_ACCOUNT
)
2384 gfp
|= __GFP_ACCOUNT
;
2386 if (!(gfp
& __GFP_ACCOUNT
))
2389 if (current
->memcg_kmem_skip_account
)
2392 memcg
= get_mem_cgroup_from_mm(current
->mm
);
2393 kmemcg_id
= READ_ONCE(memcg
->kmemcg_id
);
2397 memcg_cachep
= cache_from_memcg_idx(cachep
, kmemcg_id
);
2398 if (likely(memcg_cachep
))
2399 return memcg_cachep
;
2402 * If we are in a safe context (can wait, and not in interrupt
2403 * context), we could be be predictable and return right away.
2404 * This would guarantee that the allocation being performed
2405 * already belongs in the new cache.
2407 * However, there are some clashes that can arrive from locking.
2408 * For instance, because we acquire the slab_mutex while doing
2409 * memcg_create_kmem_cache, this means no further allocation
2410 * could happen with the slab_mutex held. So it's better to
2413 memcg_schedule_kmem_cache_create(memcg
, cachep
);
2415 css_put(&memcg
->css
);
2419 void __memcg_kmem_put_cache(struct kmem_cache
*cachep
)
2421 if (!is_root_cache(cachep
))
2422 css_put(&cachep
->memcg_params
.memcg
->css
);
2425 int __memcg_kmem_charge_memcg(struct page
*page
, gfp_t gfp
, int order
,
2426 struct mem_cgroup
*memcg
)
2428 unsigned int nr_pages
= 1 << order
;
2429 struct page_counter
*counter
;
2432 if (!memcg_kmem_is_active(memcg
))
2435 if (!page_counter_try_charge(&memcg
->kmem
, nr_pages
, &counter
))
2438 ret
= try_charge(memcg
, gfp
, nr_pages
);
2440 page_counter_uncharge(&memcg
->kmem
, nr_pages
);
2444 page
->mem_cgroup
= memcg
;
2449 int __memcg_kmem_charge(struct page
*page
, gfp_t gfp
, int order
)
2451 struct mem_cgroup
*memcg
;
2454 memcg
= get_mem_cgroup_from_mm(current
->mm
);
2455 ret
= __memcg_kmem_charge_memcg(page
, gfp
, order
, memcg
);
2456 css_put(&memcg
->css
);
2460 void __memcg_kmem_uncharge(struct page
*page
, int order
)
2462 struct mem_cgroup
*memcg
= page
->mem_cgroup
;
2463 unsigned int nr_pages
= 1 << order
;
2468 VM_BUG_ON_PAGE(mem_cgroup_is_root(memcg
), page
);
2470 page_counter_uncharge(&memcg
->kmem
, nr_pages
);
2471 page_counter_uncharge(&memcg
->memory
, nr_pages
);
2472 if (do_swap_account
)
2473 page_counter_uncharge(&memcg
->memsw
, nr_pages
);
2475 page
->mem_cgroup
= NULL
;
2476 css_put_many(&memcg
->css
, nr_pages
);
2478 #endif /* CONFIG_MEMCG_KMEM */
2480 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
2483 * Because tail pages are not marked as "used", set it. We're under
2484 * zone->lru_lock, 'splitting on pmd' and compound_lock.
2485 * charge/uncharge will be never happen and move_account() is done under
2486 * compound_lock(), so we don't have to take care of races.
2488 void mem_cgroup_split_huge_fixup(struct page
*head
)
2492 if (mem_cgroup_disabled())
2495 for (i
= 1; i
< HPAGE_PMD_NR
; i
++)
2496 head
[i
].mem_cgroup
= head
->mem_cgroup
;
2498 __this_cpu_sub(head
->mem_cgroup
->stat
->count
[MEM_CGROUP_STAT_RSS_HUGE
],
2501 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
2503 #ifdef CONFIG_MEMCG_SWAP
2504 static void mem_cgroup_swap_statistics(struct mem_cgroup
*memcg
,
2507 int val
= (charge
) ? 1 : -1;
2508 this_cpu_add(memcg
->stat
->count
[MEM_CGROUP_STAT_SWAP
], val
);
2512 * mem_cgroup_move_swap_account - move swap charge and swap_cgroup's record.
2513 * @entry: swap entry to be moved
2514 * @from: mem_cgroup which the entry is moved from
2515 * @to: mem_cgroup which the entry is moved to
2517 * It succeeds only when the swap_cgroup's record for this entry is the same
2518 * as the mem_cgroup's id of @from.
2520 * Returns 0 on success, -EINVAL on failure.
2522 * The caller must have charged to @to, IOW, called page_counter_charge() about
2523 * both res and memsw, and called css_get().
2525 static int mem_cgroup_move_swap_account(swp_entry_t entry
,
2526 struct mem_cgroup
*from
, struct mem_cgroup
*to
)
2528 unsigned short old_id
, new_id
;
2530 old_id
= mem_cgroup_id(from
);
2531 new_id
= mem_cgroup_id(to
);
2533 if (swap_cgroup_cmpxchg(entry
, old_id
, new_id
) == old_id
) {
2534 mem_cgroup_swap_statistics(from
, false);
2535 mem_cgroup_swap_statistics(to
, true);
2541 static inline int mem_cgroup_move_swap_account(swp_entry_t entry
,
2542 struct mem_cgroup
*from
, struct mem_cgroup
*to
)
2548 static DEFINE_MUTEX(memcg_limit_mutex
);
2550 static int mem_cgroup_resize_limit(struct mem_cgroup
*memcg
,
2551 unsigned long limit
)
2553 unsigned long curusage
;
2554 unsigned long oldusage
;
2555 bool enlarge
= false;
2560 * For keeping hierarchical_reclaim simple, how long we should retry
2561 * is depends on callers. We set our retry-count to be function
2562 * of # of children which we should visit in this loop.
2564 retry_count
= MEM_CGROUP_RECLAIM_RETRIES
*
2565 mem_cgroup_count_children(memcg
);
2567 oldusage
= page_counter_read(&memcg
->memory
);
2570 if (signal_pending(current
)) {
2575 mutex_lock(&memcg_limit_mutex
);
2576 if (limit
> memcg
->memsw
.limit
) {
2577 mutex_unlock(&memcg_limit_mutex
);
2581 if (limit
> memcg
->memory
.limit
)
2583 ret
= page_counter_limit(&memcg
->memory
, limit
);
2584 mutex_unlock(&memcg_limit_mutex
);
2589 try_to_free_mem_cgroup_pages(memcg
, 1, GFP_KERNEL
, true);
2591 curusage
= page_counter_read(&memcg
->memory
);
2592 /* Usage is reduced ? */
2593 if (curusage
>= oldusage
)
2596 oldusage
= curusage
;
2597 } while (retry_count
);
2599 if (!ret
&& enlarge
)
2600 memcg_oom_recover(memcg
);
2605 static int mem_cgroup_resize_memsw_limit(struct mem_cgroup
*memcg
,
2606 unsigned long limit
)
2608 unsigned long curusage
;
2609 unsigned long oldusage
;
2610 bool enlarge
= false;
2614 /* see mem_cgroup_resize_res_limit */
2615 retry_count
= MEM_CGROUP_RECLAIM_RETRIES
*
2616 mem_cgroup_count_children(memcg
);
2618 oldusage
= page_counter_read(&memcg
->memsw
);
2621 if (signal_pending(current
)) {
2626 mutex_lock(&memcg_limit_mutex
);
2627 if (limit
< memcg
->memory
.limit
) {
2628 mutex_unlock(&memcg_limit_mutex
);
2632 if (limit
> memcg
->memsw
.limit
)
2634 ret
= page_counter_limit(&memcg
->memsw
, limit
);
2635 mutex_unlock(&memcg_limit_mutex
);
2640 try_to_free_mem_cgroup_pages(memcg
, 1, GFP_KERNEL
, false);
2642 curusage
= page_counter_read(&memcg
->memsw
);
2643 /* Usage is reduced ? */
2644 if (curusage
>= oldusage
)
2647 oldusage
= curusage
;
2648 } while (retry_count
);
2650 if (!ret
&& enlarge
)
2651 memcg_oom_recover(memcg
);
2656 unsigned long mem_cgroup_soft_limit_reclaim(struct zone
*zone
, int order
,
2658 unsigned long *total_scanned
)
2660 unsigned long nr_reclaimed
= 0;
2661 struct mem_cgroup_per_zone
*mz
, *next_mz
= NULL
;
2662 unsigned long reclaimed
;
2664 struct mem_cgroup_tree_per_zone
*mctz
;
2665 unsigned long excess
;
2666 unsigned long nr_scanned
;
2671 mctz
= soft_limit_tree_node_zone(zone_to_nid(zone
), zone_idx(zone
));
2673 * This loop can run a while, specially if mem_cgroup's continuously
2674 * keep exceeding their soft limit and putting the system under
2681 mz
= mem_cgroup_largest_soft_limit_node(mctz
);
2686 reclaimed
= mem_cgroup_soft_reclaim(mz
->memcg
, zone
,
2687 gfp_mask
, &nr_scanned
);
2688 nr_reclaimed
+= reclaimed
;
2689 *total_scanned
+= nr_scanned
;
2690 spin_lock_irq(&mctz
->lock
);
2691 __mem_cgroup_remove_exceeded(mz
, mctz
);
2694 * If we failed to reclaim anything from this memory cgroup
2695 * it is time to move on to the next cgroup
2699 next_mz
= __mem_cgroup_largest_soft_limit_node(mctz
);
2701 excess
= soft_limit_excess(mz
->memcg
);
2703 * One school of thought says that we should not add
2704 * back the node to the tree if reclaim returns 0.
2705 * But our reclaim could return 0, simply because due
2706 * to priority we are exposing a smaller subset of
2707 * memory to reclaim from. Consider this as a longer
2710 /* If excess == 0, no tree ops */
2711 __mem_cgroup_insert_exceeded(mz
, mctz
, excess
);
2712 spin_unlock_irq(&mctz
->lock
);
2713 css_put(&mz
->memcg
->css
);
2716 * Could not reclaim anything and there are no more
2717 * mem cgroups to try or we seem to be looping without
2718 * reclaiming anything.
2720 if (!nr_reclaimed
&&
2722 loop
> MEM_CGROUP_MAX_SOFT_LIMIT_RECLAIM_LOOPS
))
2724 } while (!nr_reclaimed
);
2726 css_put(&next_mz
->memcg
->css
);
2727 return nr_reclaimed
;
2731 * Test whether @memcg has children, dead or alive. Note that this
2732 * function doesn't care whether @memcg has use_hierarchy enabled and
2733 * returns %true if there are child csses according to the cgroup
2734 * hierarchy. Testing use_hierarchy is the caller's responsiblity.
2736 static inline bool memcg_has_children(struct mem_cgroup
*memcg
)
2741 * The lock does not prevent addition or deletion of children, but
2742 * it prevents a new child from being initialized based on this
2743 * parent in css_online(), so it's enough to decide whether
2744 * hierarchically inherited attributes can still be changed or not.
2746 lockdep_assert_held(&memcg_create_mutex
);
2749 ret
= css_next_child(NULL
, &memcg
->css
);
2755 * Reclaims as many pages from the given memcg as possible and moves
2756 * the rest to the parent.
2758 * Caller is responsible for holding css reference for memcg.
2760 static int mem_cgroup_force_empty(struct mem_cgroup
*memcg
)
2762 int nr_retries
= MEM_CGROUP_RECLAIM_RETRIES
;
2764 /* we call try-to-free pages for make this cgroup empty */
2765 lru_add_drain_all();
2766 /* try to free all pages in this cgroup */
2767 while (nr_retries
&& page_counter_read(&memcg
->memory
)) {
2770 if (signal_pending(current
))
2773 progress
= try_to_free_mem_cgroup_pages(memcg
, 1,
2777 /* maybe some writeback is necessary */
2778 congestion_wait(BLK_RW_ASYNC
, HZ
/10);
2786 static ssize_t
mem_cgroup_force_empty_write(struct kernfs_open_file
*of
,
2787 char *buf
, size_t nbytes
,
2790 struct mem_cgroup
*memcg
= mem_cgroup_from_css(of_css(of
));
2792 if (mem_cgroup_is_root(memcg
))
2794 return mem_cgroup_force_empty(memcg
) ?: nbytes
;
2797 static u64
mem_cgroup_hierarchy_read(struct cgroup_subsys_state
*css
,
2800 return mem_cgroup_from_css(css
)->use_hierarchy
;
2803 static int mem_cgroup_hierarchy_write(struct cgroup_subsys_state
*css
,
2804 struct cftype
*cft
, u64 val
)
2807 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
2808 struct mem_cgroup
*parent_memcg
= mem_cgroup_from_css(memcg
->css
.parent
);
2810 mutex_lock(&memcg_create_mutex
);
2812 if (memcg
->use_hierarchy
== val
)
2816 * If parent's use_hierarchy is set, we can't make any modifications
2817 * in the child subtrees. If it is unset, then the change can
2818 * occur, provided the current cgroup has no children.
2820 * For the root cgroup, parent_mem is NULL, we allow value to be
2821 * set if there are no children.
2823 if ((!parent_memcg
|| !parent_memcg
->use_hierarchy
) &&
2824 (val
== 1 || val
== 0)) {
2825 if (!memcg_has_children(memcg
))
2826 memcg
->use_hierarchy
= val
;
2833 mutex_unlock(&memcg_create_mutex
);
2838 static unsigned long tree_stat(struct mem_cgroup
*memcg
,
2839 enum mem_cgroup_stat_index idx
)
2841 struct mem_cgroup
*iter
;
2842 unsigned long val
= 0;
2844 for_each_mem_cgroup_tree(iter
, memcg
)
2845 val
+= mem_cgroup_read_stat(iter
, idx
);
2850 static unsigned long mem_cgroup_usage(struct mem_cgroup
*memcg
, bool swap
)
2854 if (mem_cgroup_is_root(memcg
)) {
2855 val
= tree_stat(memcg
, MEM_CGROUP_STAT_CACHE
);
2856 val
+= tree_stat(memcg
, MEM_CGROUP_STAT_RSS
);
2858 val
+= tree_stat(memcg
, MEM_CGROUP_STAT_SWAP
);
2861 val
= page_counter_read(&memcg
->memory
);
2863 val
= page_counter_read(&memcg
->memsw
);
2876 static u64
mem_cgroup_read_u64(struct cgroup_subsys_state
*css
,
2879 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
2880 struct page_counter
*counter
;
2882 switch (MEMFILE_TYPE(cft
->private)) {
2884 counter
= &memcg
->memory
;
2887 counter
= &memcg
->memsw
;
2890 counter
= &memcg
->kmem
;
2896 switch (MEMFILE_ATTR(cft
->private)) {
2898 if (counter
== &memcg
->memory
)
2899 return (u64
)mem_cgroup_usage(memcg
, false) * PAGE_SIZE
;
2900 if (counter
== &memcg
->memsw
)
2901 return (u64
)mem_cgroup_usage(memcg
, true) * PAGE_SIZE
;
2902 return (u64
)page_counter_read(counter
) * PAGE_SIZE
;
2904 return (u64
)counter
->limit
* PAGE_SIZE
;
2906 return (u64
)counter
->watermark
* PAGE_SIZE
;
2908 return counter
->failcnt
;
2909 case RES_SOFT_LIMIT
:
2910 return (u64
)memcg
->soft_limit
* PAGE_SIZE
;
2916 #ifdef CONFIG_MEMCG_KMEM
2917 static int memcg_activate_kmem(struct mem_cgroup
*memcg
,
2918 unsigned long nr_pages
)
2923 BUG_ON(memcg
->kmemcg_id
>= 0);
2924 BUG_ON(memcg
->kmem_acct_activated
);
2925 BUG_ON(memcg
->kmem_acct_active
);
2928 * For simplicity, we won't allow this to be disabled. It also can't
2929 * be changed if the cgroup has children already, or if tasks had
2932 * If tasks join before we set the limit, a person looking at
2933 * kmem.usage_in_bytes will have no way to determine when it took
2934 * place, which makes the value quite meaningless.
2936 * After it first became limited, changes in the value of the limit are
2937 * of course permitted.
2939 mutex_lock(&memcg_create_mutex
);
2940 if (cgroup_is_populated(memcg
->css
.cgroup
) ||
2941 (memcg
->use_hierarchy
&& memcg_has_children(memcg
)))
2943 mutex_unlock(&memcg_create_mutex
);
2947 memcg_id
= memcg_alloc_cache_id();
2954 * We couldn't have accounted to this cgroup, because it hasn't got
2955 * activated yet, so this should succeed.
2957 err
= page_counter_limit(&memcg
->kmem
, nr_pages
);
2960 static_key_slow_inc(&memcg_kmem_enabled_key
);
2962 * A memory cgroup is considered kmem-active as soon as it gets
2963 * kmemcg_id. Setting the id after enabling static branching will
2964 * guarantee no one starts accounting before all call sites are
2967 memcg
->kmemcg_id
= memcg_id
;
2968 memcg
->kmem_acct_activated
= true;
2969 memcg
->kmem_acct_active
= true;
2974 static int memcg_update_kmem_limit(struct mem_cgroup
*memcg
,
2975 unsigned long limit
)
2979 mutex_lock(&memcg_limit_mutex
);
2980 if (!memcg_kmem_is_active(memcg
))
2981 ret
= memcg_activate_kmem(memcg
, limit
);
2983 ret
= page_counter_limit(&memcg
->kmem
, limit
);
2984 mutex_unlock(&memcg_limit_mutex
);
2988 static int memcg_propagate_kmem(struct mem_cgroup
*memcg
)
2991 struct mem_cgroup
*parent
= parent_mem_cgroup(memcg
);
2996 mutex_lock(&memcg_limit_mutex
);
2998 * If the parent cgroup is not kmem-active now, it cannot be activated
2999 * after this point, because it has at least one child already.
3001 if (memcg_kmem_is_active(parent
))
3002 ret
= memcg_activate_kmem(memcg
, PAGE_COUNTER_MAX
);
3003 mutex_unlock(&memcg_limit_mutex
);
3007 static int memcg_update_kmem_limit(struct mem_cgroup
*memcg
,
3008 unsigned long limit
)
3012 #endif /* CONFIG_MEMCG_KMEM */
3015 * The user of this function is...
3018 static ssize_t
mem_cgroup_write(struct kernfs_open_file
*of
,
3019 char *buf
, size_t nbytes
, loff_t off
)
3021 struct mem_cgroup
*memcg
= mem_cgroup_from_css(of_css(of
));
3022 unsigned long nr_pages
;
3025 buf
= strstrip(buf
);
3026 ret
= page_counter_memparse(buf
, "-1", &nr_pages
);
3030 switch (MEMFILE_ATTR(of_cft(of
)->private)) {
3032 if (mem_cgroup_is_root(memcg
)) { /* Can't set limit on root */
3036 switch (MEMFILE_TYPE(of_cft(of
)->private)) {
3038 ret
= mem_cgroup_resize_limit(memcg
, nr_pages
);
3041 ret
= mem_cgroup_resize_memsw_limit(memcg
, nr_pages
);
3044 ret
= memcg_update_kmem_limit(memcg
, nr_pages
);
3048 case RES_SOFT_LIMIT
:
3049 memcg
->soft_limit
= nr_pages
;
3053 return ret
?: nbytes
;
3056 static ssize_t
mem_cgroup_reset(struct kernfs_open_file
*of
, char *buf
,
3057 size_t nbytes
, loff_t off
)
3059 struct mem_cgroup
*memcg
= mem_cgroup_from_css(of_css(of
));
3060 struct page_counter
*counter
;
3062 switch (MEMFILE_TYPE(of_cft(of
)->private)) {
3064 counter
= &memcg
->memory
;
3067 counter
= &memcg
->memsw
;
3070 counter
= &memcg
->kmem
;
3076 switch (MEMFILE_ATTR(of_cft(of
)->private)) {
3078 page_counter_reset_watermark(counter
);
3081 counter
->failcnt
= 0;
3090 static u64
mem_cgroup_move_charge_read(struct cgroup_subsys_state
*css
,
3093 return mem_cgroup_from_css(css
)->move_charge_at_immigrate
;
3097 static int mem_cgroup_move_charge_write(struct cgroup_subsys_state
*css
,
3098 struct cftype
*cft
, u64 val
)
3100 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
3102 if (val
& ~MOVE_MASK
)
3106 * No kind of locking is needed in here, because ->can_attach() will
3107 * check this value once in the beginning of the process, and then carry
3108 * on with stale data. This means that changes to this value will only
3109 * affect task migrations starting after the change.
3111 memcg
->move_charge_at_immigrate
= val
;
3115 static int mem_cgroup_move_charge_write(struct cgroup_subsys_state
*css
,
3116 struct cftype
*cft
, u64 val
)
3123 static int memcg_numa_stat_show(struct seq_file
*m
, void *v
)
3127 unsigned int lru_mask
;
3130 static const struct numa_stat stats
[] = {
3131 { "total", LRU_ALL
},
3132 { "file", LRU_ALL_FILE
},
3133 { "anon", LRU_ALL_ANON
},
3134 { "unevictable", BIT(LRU_UNEVICTABLE
) },
3136 const struct numa_stat
*stat
;
3139 struct mem_cgroup
*memcg
= mem_cgroup_from_css(seq_css(m
));
3141 for (stat
= stats
; stat
< stats
+ ARRAY_SIZE(stats
); stat
++) {
3142 nr
= mem_cgroup_nr_lru_pages(memcg
, stat
->lru_mask
);
3143 seq_printf(m
, "%s=%lu", stat
->name
, nr
);
3144 for_each_node_state(nid
, N_MEMORY
) {
3145 nr
= mem_cgroup_node_nr_lru_pages(memcg
, nid
,
3147 seq_printf(m
, " N%d=%lu", nid
, nr
);
3152 for (stat
= stats
; stat
< stats
+ ARRAY_SIZE(stats
); stat
++) {
3153 struct mem_cgroup
*iter
;
3156 for_each_mem_cgroup_tree(iter
, memcg
)
3157 nr
+= mem_cgroup_nr_lru_pages(iter
, stat
->lru_mask
);
3158 seq_printf(m
, "hierarchical_%s=%lu", stat
->name
, nr
);
3159 for_each_node_state(nid
, N_MEMORY
) {
3161 for_each_mem_cgroup_tree(iter
, memcg
)
3162 nr
+= mem_cgroup_node_nr_lru_pages(
3163 iter
, nid
, stat
->lru_mask
);
3164 seq_printf(m
, " N%d=%lu", nid
, nr
);
3171 #endif /* CONFIG_NUMA */
3173 static int memcg_stat_show(struct seq_file
*m
, void *v
)
3175 struct mem_cgroup
*memcg
= mem_cgroup_from_css(seq_css(m
));
3176 unsigned long memory
, memsw
;
3177 struct mem_cgroup
*mi
;
3180 BUILD_BUG_ON(ARRAY_SIZE(mem_cgroup_stat_names
) !=
3181 MEM_CGROUP_STAT_NSTATS
);
3182 BUILD_BUG_ON(ARRAY_SIZE(mem_cgroup_events_names
) !=
3183 MEM_CGROUP_EVENTS_NSTATS
);
3184 BUILD_BUG_ON(ARRAY_SIZE(mem_cgroup_lru_names
) != NR_LRU_LISTS
);
3186 for (i
= 0; i
< MEM_CGROUP_STAT_NSTATS
; i
++) {
3187 if (i
== MEM_CGROUP_STAT_SWAP
&& !do_swap_account
)
3189 seq_printf(m
, "%s %lu\n", mem_cgroup_stat_names
[i
],
3190 mem_cgroup_read_stat(memcg
, i
) * PAGE_SIZE
);
3193 for (i
= 0; i
< MEM_CGROUP_EVENTS_NSTATS
; i
++)
3194 seq_printf(m
, "%s %lu\n", mem_cgroup_events_names
[i
],
3195 mem_cgroup_read_events(memcg
, i
));
3197 for (i
= 0; i
< NR_LRU_LISTS
; i
++)
3198 seq_printf(m
, "%s %lu\n", mem_cgroup_lru_names
[i
],
3199 mem_cgroup_nr_lru_pages(memcg
, BIT(i
)) * PAGE_SIZE
);
3201 /* Hierarchical information */
3202 memory
= memsw
= PAGE_COUNTER_MAX
;
3203 for (mi
= memcg
; mi
; mi
= parent_mem_cgroup(mi
)) {
3204 memory
= min(memory
, mi
->memory
.limit
);
3205 memsw
= min(memsw
, mi
->memsw
.limit
);
3207 seq_printf(m
, "hierarchical_memory_limit %llu\n",
3208 (u64
)memory
* PAGE_SIZE
);
3209 if (do_swap_account
)
3210 seq_printf(m
, "hierarchical_memsw_limit %llu\n",
3211 (u64
)memsw
* PAGE_SIZE
);
3213 for (i
= 0; i
< MEM_CGROUP_STAT_NSTATS
; i
++) {
3214 unsigned long long val
= 0;
3216 if (i
== MEM_CGROUP_STAT_SWAP
&& !do_swap_account
)
3218 for_each_mem_cgroup_tree(mi
, memcg
)
3219 val
+= mem_cgroup_read_stat(mi
, i
) * PAGE_SIZE
;
3220 seq_printf(m
, "total_%s %llu\n", mem_cgroup_stat_names
[i
], val
);
3223 for (i
= 0; i
< MEM_CGROUP_EVENTS_NSTATS
; i
++) {
3224 unsigned long long val
= 0;
3226 for_each_mem_cgroup_tree(mi
, memcg
)
3227 val
+= mem_cgroup_read_events(mi
, i
);
3228 seq_printf(m
, "total_%s %llu\n",
3229 mem_cgroup_events_names
[i
], val
);
3232 for (i
= 0; i
< NR_LRU_LISTS
; i
++) {
3233 unsigned long long val
= 0;
3235 for_each_mem_cgroup_tree(mi
, memcg
)
3236 val
+= mem_cgroup_nr_lru_pages(mi
, BIT(i
)) * PAGE_SIZE
;
3237 seq_printf(m
, "total_%s %llu\n", mem_cgroup_lru_names
[i
], val
);
3240 #ifdef CONFIG_DEBUG_VM
3243 struct mem_cgroup_per_zone
*mz
;
3244 struct zone_reclaim_stat
*rstat
;
3245 unsigned long recent_rotated
[2] = {0, 0};
3246 unsigned long recent_scanned
[2] = {0, 0};
3248 for_each_online_node(nid
)
3249 for (zid
= 0; zid
< MAX_NR_ZONES
; zid
++) {
3250 mz
= &memcg
->nodeinfo
[nid
]->zoneinfo
[zid
];
3251 rstat
= &mz
->lruvec
.reclaim_stat
;
3253 recent_rotated
[0] += rstat
->recent_rotated
[0];
3254 recent_rotated
[1] += rstat
->recent_rotated
[1];
3255 recent_scanned
[0] += rstat
->recent_scanned
[0];
3256 recent_scanned
[1] += rstat
->recent_scanned
[1];
3258 seq_printf(m
, "recent_rotated_anon %lu\n", recent_rotated
[0]);
3259 seq_printf(m
, "recent_rotated_file %lu\n", recent_rotated
[1]);
3260 seq_printf(m
, "recent_scanned_anon %lu\n", recent_scanned
[0]);
3261 seq_printf(m
, "recent_scanned_file %lu\n", recent_scanned
[1]);
3268 static u64
mem_cgroup_swappiness_read(struct cgroup_subsys_state
*css
,
3271 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
3273 return mem_cgroup_swappiness(memcg
);
3276 static int mem_cgroup_swappiness_write(struct cgroup_subsys_state
*css
,
3277 struct cftype
*cft
, u64 val
)
3279 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
3285 memcg
->swappiness
= val
;
3287 vm_swappiness
= val
;
3292 static void __mem_cgroup_threshold(struct mem_cgroup
*memcg
, bool swap
)
3294 struct mem_cgroup_threshold_ary
*t
;
3295 unsigned long usage
;
3300 t
= rcu_dereference(memcg
->thresholds
.primary
);
3302 t
= rcu_dereference(memcg
->memsw_thresholds
.primary
);
3307 usage
= mem_cgroup_usage(memcg
, swap
);
3310 * current_threshold points to threshold just below or equal to usage.
3311 * If it's not true, a threshold was crossed after last
3312 * call of __mem_cgroup_threshold().
3314 i
= t
->current_threshold
;
3317 * Iterate backward over array of thresholds starting from
3318 * current_threshold and check if a threshold is crossed.
3319 * If none of thresholds below usage is crossed, we read
3320 * only one element of the array here.
3322 for (; i
>= 0 && unlikely(t
->entries
[i
].threshold
> usage
); i
--)
3323 eventfd_signal(t
->entries
[i
].eventfd
, 1);
3325 /* i = current_threshold + 1 */
3329 * Iterate forward over array of thresholds starting from
3330 * current_threshold+1 and check if a threshold is crossed.
3331 * If none of thresholds above usage is crossed, we read
3332 * only one element of the array here.
3334 for (; i
< t
->size
&& unlikely(t
->entries
[i
].threshold
<= usage
); i
++)
3335 eventfd_signal(t
->entries
[i
].eventfd
, 1);
3337 /* Update current_threshold */
3338 t
->current_threshold
= i
- 1;
3343 static void mem_cgroup_threshold(struct mem_cgroup
*memcg
)
3346 __mem_cgroup_threshold(memcg
, false);
3347 if (do_swap_account
)
3348 __mem_cgroup_threshold(memcg
, true);
3350 memcg
= parent_mem_cgroup(memcg
);
3354 static int compare_thresholds(const void *a
, const void *b
)
3356 const struct mem_cgroup_threshold
*_a
= a
;
3357 const struct mem_cgroup_threshold
*_b
= b
;
3359 if (_a
->threshold
> _b
->threshold
)
3362 if (_a
->threshold
< _b
->threshold
)
3368 static int mem_cgroup_oom_notify_cb(struct mem_cgroup
*memcg
)
3370 struct mem_cgroup_eventfd_list
*ev
;
3372 spin_lock(&memcg_oom_lock
);
3374 list_for_each_entry(ev
, &memcg
->oom_notify
, list
)
3375 eventfd_signal(ev
->eventfd
, 1);
3377 spin_unlock(&memcg_oom_lock
);
3381 static void mem_cgroup_oom_notify(struct mem_cgroup
*memcg
)
3383 struct mem_cgroup
*iter
;
3385 for_each_mem_cgroup_tree(iter
, memcg
)
3386 mem_cgroup_oom_notify_cb(iter
);
3389 static int __mem_cgroup_usage_register_event(struct mem_cgroup
*memcg
,
3390 struct eventfd_ctx
*eventfd
, const char *args
, enum res_type type
)
3392 struct mem_cgroup_thresholds
*thresholds
;
3393 struct mem_cgroup_threshold_ary
*new;
3394 unsigned long threshold
;
3395 unsigned long usage
;
3398 ret
= page_counter_memparse(args
, "-1", &threshold
);
3402 mutex_lock(&memcg
->thresholds_lock
);
3405 thresholds
= &memcg
->thresholds
;
3406 usage
= mem_cgroup_usage(memcg
, false);
3407 } else if (type
== _MEMSWAP
) {
3408 thresholds
= &memcg
->memsw_thresholds
;
3409 usage
= mem_cgroup_usage(memcg
, true);
3413 /* Check if a threshold crossed before adding a new one */
3414 if (thresholds
->primary
)
3415 __mem_cgroup_threshold(memcg
, type
== _MEMSWAP
);
3417 size
= thresholds
->primary
? thresholds
->primary
->size
+ 1 : 1;
3419 /* Allocate memory for new array of thresholds */
3420 new = kmalloc(sizeof(*new) + size
* sizeof(struct mem_cgroup_threshold
),
3428 /* Copy thresholds (if any) to new array */
3429 if (thresholds
->primary
) {
3430 memcpy(new->entries
, thresholds
->primary
->entries
, (size
- 1) *
3431 sizeof(struct mem_cgroup_threshold
));
3434 /* Add new threshold */
3435 new->entries
[size
- 1].eventfd
= eventfd
;
3436 new->entries
[size
- 1].threshold
= threshold
;
3438 /* Sort thresholds. Registering of new threshold isn't time-critical */
3439 sort(new->entries
, size
, sizeof(struct mem_cgroup_threshold
),
3440 compare_thresholds
, NULL
);
3442 /* Find current threshold */
3443 new->current_threshold
= -1;
3444 for (i
= 0; i
< size
; i
++) {
3445 if (new->entries
[i
].threshold
<= usage
) {
3447 * new->current_threshold will not be used until
3448 * rcu_assign_pointer(), so it's safe to increment
3451 ++new->current_threshold
;
3456 /* Free old spare buffer and save old primary buffer as spare */
3457 kfree(thresholds
->spare
);
3458 thresholds
->spare
= thresholds
->primary
;
3460 rcu_assign_pointer(thresholds
->primary
, new);
3462 /* To be sure that nobody uses thresholds */
3466 mutex_unlock(&memcg
->thresholds_lock
);
3471 static int mem_cgroup_usage_register_event(struct mem_cgroup
*memcg
,
3472 struct eventfd_ctx
*eventfd
, const char *args
)
3474 return __mem_cgroup_usage_register_event(memcg
, eventfd
, args
, _MEM
);
3477 static int memsw_cgroup_usage_register_event(struct mem_cgroup
*memcg
,
3478 struct eventfd_ctx
*eventfd
, const char *args
)
3480 return __mem_cgroup_usage_register_event(memcg
, eventfd
, args
, _MEMSWAP
);
3483 static void __mem_cgroup_usage_unregister_event(struct mem_cgroup
*memcg
,
3484 struct eventfd_ctx
*eventfd
, enum res_type type
)
3486 struct mem_cgroup_thresholds
*thresholds
;
3487 struct mem_cgroup_threshold_ary
*new;
3488 unsigned long usage
;
3491 mutex_lock(&memcg
->thresholds_lock
);
3494 thresholds
= &memcg
->thresholds
;
3495 usage
= mem_cgroup_usage(memcg
, false);
3496 } else if (type
== _MEMSWAP
) {
3497 thresholds
= &memcg
->memsw_thresholds
;
3498 usage
= mem_cgroup_usage(memcg
, true);
3502 if (!thresholds
->primary
)
3505 /* Check if a threshold crossed before removing */
3506 __mem_cgroup_threshold(memcg
, type
== _MEMSWAP
);
3508 /* Calculate new number of threshold */
3510 for (i
= 0; i
< thresholds
->primary
->size
; i
++) {
3511 if (thresholds
->primary
->entries
[i
].eventfd
!= eventfd
)
3515 new = thresholds
->spare
;
3517 /* Set thresholds array to NULL if we don't have thresholds */
3526 /* Copy thresholds and find current threshold */
3527 new->current_threshold
= -1;
3528 for (i
= 0, j
= 0; i
< thresholds
->primary
->size
; i
++) {
3529 if (thresholds
->primary
->entries
[i
].eventfd
== eventfd
)
3532 new->entries
[j
] = thresholds
->primary
->entries
[i
];
3533 if (new->entries
[j
].threshold
<= usage
) {
3535 * new->current_threshold will not be used
3536 * until rcu_assign_pointer(), so it's safe to increment
3539 ++new->current_threshold
;
3545 /* Swap primary and spare array */
3546 thresholds
->spare
= thresholds
->primary
;
3547 /* If all events are unregistered, free the spare array */
3549 kfree(thresholds
->spare
);
3550 thresholds
->spare
= NULL
;
3553 rcu_assign_pointer(thresholds
->primary
, new);
3555 /* To be sure that nobody uses thresholds */
3558 mutex_unlock(&memcg
->thresholds_lock
);
3561 static void mem_cgroup_usage_unregister_event(struct mem_cgroup
*memcg
,
3562 struct eventfd_ctx
*eventfd
)
3564 return __mem_cgroup_usage_unregister_event(memcg
, eventfd
, _MEM
);
3567 static void memsw_cgroup_usage_unregister_event(struct mem_cgroup
*memcg
,
3568 struct eventfd_ctx
*eventfd
)
3570 return __mem_cgroup_usage_unregister_event(memcg
, eventfd
, _MEMSWAP
);
3573 static int mem_cgroup_oom_register_event(struct mem_cgroup
*memcg
,
3574 struct eventfd_ctx
*eventfd
, const char *args
)
3576 struct mem_cgroup_eventfd_list
*event
;
3578 event
= kmalloc(sizeof(*event
), GFP_KERNEL
);
3582 spin_lock(&memcg_oom_lock
);
3584 event
->eventfd
= eventfd
;
3585 list_add(&event
->list
, &memcg
->oom_notify
);
3587 /* already in OOM ? */
3588 if (memcg
->under_oom
)
3589 eventfd_signal(eventfd
, 1);
3590 spin_unlock(&memcg_oom_lock
);
3595 static void mem_cgroup_oom_unregister_event(struct mem_cgroup
*memcg
,
3596 struct eventfd_ctx
*eventfd
)
3598 struct mem_cgroup_eventfd_list
*ev
, *tmp
;
3600 spin_lock(&memcg_oom_lock
);
3602 list_for_each_entry_safe(ev
, tmp
, &memcg
->oom_notify
, list
) {
3603 if (ev
->eventfd
== eventfd
) {
3604 list_del(&ev
->list
);
3609 spin_unlock(&memcg_oom_lock
);
3612 static int mem_cgroup_oom_control_read(struct seq_file
*sf
, void *v
)
3614 struct mem_cgroup
*memcg
= mem_cgroup_from_css(seq_css(sf
));
3616 seq_printf(sf
, "oom_kill_disable %d\n", memcg
->oom_kill_disable
);
3617 seq_printf(sf
, "under_oom %d\n", (bool)memcg
->under_oom
);
3621 static int mem_cgroup_oom_control_write(struct cgroup_subsys_state
*css
,
3622 struct cftype
*cft
, u64 val
)
3624 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
3626 /* cannot set to root cgroup and only 0 and 1 are allowed */
3627 if (!css
->parent
|| !((val
== 0) || (val
== 1)))
3630 memcg
->oom_kill_disable
= val
;
3632 memcg_oom_recover(memcg
);
3637 #ifdef CONFIG_MEMCG_KMEM
3638 static int memcg_init_kmem(struct mem_cgroup
*memcg
, struct cgroup_subsys
*ss
)
3642 ret
= memcg_propagate_kmem(memcg
);
3646 return tcp_init_cgroup(memcg
, ss
);
3649 static void memcg_deactivate_kmem(struct mem_cgroup
*memcg
)
3651 struct cgroup_subsys_state
*css
;
3652 struct mem_cgroup
*parent
, *child
;
3655 if (!memcg
->kmem_acct_active
)
3659 * Clear the 'active' flag before clearing memcg_caches arrays entries.
3660 * Since we take the slab_mutex in memcg_deactivate_kmem_caches(), it
3661 * guarantees no cache will be created for this cgroup after we are
3662 * done (see memcg_create_kmem_cache()).
3664 memcg
->kmem_acct_active
= false;
3666 memcg_deactivate_kmem_caches(memcg
);
3668 kmemcg_id
= memcg
->kmemcg_id
;
3669 BUG_ON(kmemcg_id
< 0);
3671 parent
= parent_mem_cgroup(memcg
);
3673 parent
= root_mem_cgroup
;
3676 * Change kmemcg_id of this cgroup and all its descendants to the
3677 * parent's id, and then move all entries from this cgroup's list_lrus
3678 * to ones of the parent. After we have finished, all list_lrus
3679 * corresponding to this cgroup are guaranteed to remain empty. The
3680 * ordering is imposed by list_lru_node->lock taken by
3681 * memcg_drain_all_list_lrus().
3683 css_for_each_descendant_pre(css
, &memcg
->css
) {
3684 child
= mem_cgroup_from_css(css
);
3685 BUG_ON(child
->kmemcg_id
!= kmemcg_id
);
3686 child
->kmemcg_id
= parent
->kmemcg_id
;
3687 if (!memcg
->use_hierarchy
)
3690 memcg_drain_all_list_lrus(kmemcg_id
, parent
->kmemcg_id
);
3692 memcg_free_cache_id(kmemcg_id
);
3695 static void memcg_destroy_kmem(struct mem_cgroup
*memcg
)
3697 if (memcg
->kmem_acct_activated
) {
3698 memcg_destroy_kmem_caches(memcg
);
3699 static_key_slow_dec(&memcg_kmem_enabled_key
);
3700 WARN_ON(page_counter_read(&memcg
->kmem
));
3702 tcp_destroy_cgroup(memcg
);
3705 static int memcg_init_kmem(struct mem_cgroup
*memcg
, struct cgroup_subsys
*ss
)
3710 static void memcg_deactivate_kmem(struct mem_cgroup
*memcg
)
3714 static void memcg_destroy_kmem(struct mem_cgroup
*memcg
)
3719 #ifdef CONFIG_CGROUP_WRITEBACK
3721 struct list_head
*mem_cgroup_cgwb_list(struct mem_cgroup
*memcg
)
3723 return &memcg
->cgwb_list
;
3726 static int memcg_wb_domain_init(struct mem_cgroup
*memcg
, gfp_t gfp
)
3728 return wb_domain_init(&memcg
->cgwb_domain
, gfp
);
3731 static void memcg_wb_domain_exit(struct mem_cgroup
*memcg
)
3733 wb_domain_exit(&memcg
->cgwb_domain
);
3736 static void memcg_wb_domain_size_changed(struct mem_cgroup
*memcg
)
3738 wb_domain_size_changed(&memcg
->cgwb_domain
);
3741 struct wb_domain
*mem_cgroup_wb_domain(struct bdi_writeback
*wb
)
3743 struct mem_cgroup
*memcg
= mem_cgroup_from_css(wb
->memcg_css
);
3745 if (!memcg
->css
.parent
)
3748 return &memcg
->cgwb_domain
;
3752 * mem_cgroup_wb_stats - retrieve writeback related stats from its memcg
3753 * @wb: bdi_writeback in question
3754 * @pfilepages: out parameter for number of file pages
3755 * @pheadroom: out parameter for number of allocatable pages according to memcg
3756 * @pdirty: out parameter for number of dirty pages
3757 * @pwriteback: out parameter for number of pages under writeback
3759 * Determine the numbers of file, headroom, dirty, and writeback pages in
3760 * @wb's memcg. File, dirty and writeback are self-explanatory. Headroom
3761 * is a bit more involved.
3763 * A memcg's headroom is "min(max, high) - used". In the hierarchy, the
3764 * headroom is calculated as the lowest headroom of itself and the
3765 * ancestors. Note that this doesn't consider the actual amount of
3766 * available memory in the system. The caller should further cap
3767 * *@pheadroom accordingly.
3769 void mem_cgroup_wb_stats(struct bdi_writeback
*wb
, unsigned long *pfilepages
,
3770 unsigned long *pheadroom
, unsigned long *pdirty
,
3771 unsigned long *pwriteback
)
3773 struct mem_cgroup
*memcg
= mem_cgroup_from_css(wb
->memcg_css
);
3774 struct mem_cgroup
*parent
;
3776 *pdirty
= mem_cgroup_read_stat(memcg
, MEM_CGROUP_STAT_DIRTY
);
3778 /* this should eventually include NR_UNSTABLE_NFS */
3779 *pwriteback
= mem_cgroup_read_stat(memcg
, MEM_CGROUP_STAT_WRITEBACK
);
3780 *pfilepages
= mem_cgroup_nr_lru_pages(memcg
, (1 << LRU_INACTIVE_FILE
) |
3781 (1 << LRU_ACTIVE_FILE
));
3782 *pheadroom
= PAGE_COUNTER_MAX
;
3784 while ((parent
= parent_mem_cgroup(memcg
))) {
3785 unsigned long ceiling
= min(memcg
->memory
.limit
, memcg
->high
);
3786 unsigned long used
= page_counter_read(&memcg
->memory
);
3788 *pheadroom
= min(*pheadroom
, ceiling
- min(ceiling
, used
));
3793 #else /* CONFIG_CGROUP_WRITEBACK */
3795 static int memcg_wb_domain_init(struct mem_cgroup
*memcg
, gfp_t gfp
)
3800 static void memcg_wb_domain_exit(struct mem_cgroup
*memcg
)
3804 static void memcg_wb_domain_size_changed(struct mem_cgroup
*memcg
)
3808 #endif /* CONFIG_CGROUP_WRITEBACK */
3811 * DO NOT USE IN NEW FILES.
3813 * "cgroup.event_control" implementation.
3815 * This is way over-engineered. It tries to support fully configurable
3816 * events for each user. Such level of flexibility is completely
3817 * unnecessary especially in the light of the planned unified hierarchy.
3819 * Please deprecate this and replace with something simpler if at all
3824 * Unregister event and free resources.
3826 * Gets called from workqueue.
3828 static void memcg_event_remove(struct work_struct
*work
)
3830 struct mem_cgroup_event
*event
=
3831 container_of(work
, struct mem_cgroup_event
, remove
);
3832 struct mem_cgroup
*memcg
= event
->memcg
;
3834 remove_wait_queue(event
->wqh
, &event
->wait
);
3836 event
->unregister_event(memcg
, event
->eventfd
);
3838 /* Notify userspace the event is going away. */
3839 eventfd_signal(event
->eventfd
, 1);
3841 eventfd_ctx_put(event
->eventfd
);
3843 css_put(&memcg
->css
);
3847 * Gets called on POLLHUP on eventfd when user closes it.
3849 * Called with wqh->lock held and interrupts disabled.
3851 static int memcg_event_wake(wait_queue_t
*wait
, unsigned mode
,
3852 int sync
, void *key
)
3854 struct mem_cgroup_event
*event
=
3855 container_of(wait
, struct mem_cgroup_event
, wait
);
3856 struct mem_cgroup
*memcg
= event
->memcg
;
3857 unsigned long flags
= (unsigned long)key
;
3859 if (flags
& POLLHUP
) {
3861 * If the event has been detached at cgroup removal, we
3862 * can simply return knowing the other side will cleanup
3865 * We can't race against event freeing since the other
3866 * side will require wqh->lock via remove_wait_queue(),
3869 spin_lock(&memcg
->event_list_lock
);
3870 if (!list_empty(&event
->list
)) {
3871 list_del_init(&event
->list
);
3873 * We are in atomic context, but cgroup_event_remove()
3874 * may sleep, so we have to call it in workqueue.
3876 schedule_work(&event
->remove
);
3878 spin_unlock(&memcg
->event_list_lock
);
3884 static void memcg_event_ptable_queue_proc(struct file
*file
,
3885 wait_queue_head_t
*wqh
, poll_table
*pt
)
3887 struct mem_cgroup_event
*event
=
3888 container_of(pt
, struct mem_cgroup_event
, pt
);
3891 add_wait_queue(wqh
, &event
->wait
);
3895 * DO NOT USE IN NEW FILES.
3897 * Parse input and register new cgroup event handler.
3899 * Input must be in format '<event_fd> <control_fd> <args>'.
3900 * Interpretation of args is defined by control file implementation.
3902 static ssize_t
memcg_write_event_control(struct kernfs_open_file
*of
,
3903 char *buf
, size_t nbytes
, loff_t off
)
3905 struct cgroup_subsys_state
*css
= of_css(of
);
3906 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
3907 struct mem_cgroup_event
*event
;
3908 struct cgroup_subsys_state
*cfile_css
;
3909 unsigned int efd
, cfd
;
3916 buf
= strstrip(buf
);
3918 efd
= simple_strtoul(buf
, &endp
, 10);
3923 cfd
= simple_strtoul(buf
, &endp
, 10);
3924 if ((*endp
!= ' ') && (*endp
!= '\0'))
3928 event
= kzalloc(sizeof(*event
), GFP_KERNEL
);
3932 event
->memcg
= memcg
;
3933 INIT_LIST_HEAD(&event
->list
);
3934 init_poll_funcptr(&event
->pt
, memcg_event_ptable_queue_proc
);
3935 init_waitqueue_func_entry(&event
->wait
, memcg_event_wake
);
3936 INIT_WORK(&event
->remove
, memcg_event_remove
);
3944 event
->eventfd
= eventfd_ctx_fileget(efile
.file
);
3945 if (IS_ERR(event
->eventfd
)) {
3946 ret
= PTR_ERR(event
->eventfd
);
3953 goto out_put_eventfd
;
3956 /* the process need read permission on control file */
3957 /* AV: shouldn't we check that it's been opened for read instead? */
3958 ret
= inode_permission(file_inode(cfile
.file
), MAY_READ
);
3963 * Determine the event callbacks and set them in @event. This used
3964 * to be done via struct cftype but cgroup core no longer knows
3965 * about these events. The following is crude but the whole thing
3966 * is for compatibility anyway.
3968 * DO NOT ADD NEW FILES.
3970 name
= cfile
.file
->f_path
.dentry
->d_name
.name
;
3972 if (!strcmp(name
, "memory.usage_in_bytes")) {
3973 event
->register_event
= mem_cgroup_usage_register_event
;
3974 event
->unregister_event
= mem_cgroup_usage_unregister_event
;
3975 } else if (!strcmp(name
, "memory.oom_control")) {
3976 event
->register_event
= mem_cgroup_oom_register_event
;
3977 event
->unregister_event
= mem_cgroup_oom_unregister_event
;
3978 } else if (!strcmp(name
, "memory.pressure_level")) {
3979 event
->register_event
= vmpressure_register_event
;
3980 event
->unregister_event
= vmpressure_unregister_event
;
3981 } else if (!strcmp(name
, "memory.memsw.usage_in_bytes")) {
3982 event
->register_event
= memsw_cgroup_usage_register_event
;
3983 event
->unregister_event
= memsw_cgroup_usage_unregister_event
;
3990 * Verify @cfile should belong to @css. Also, remaining events are
3991 * automatically removed on cgroup destruction but the removal is
3992 * asynchronous, so take an extra ref on @css.
3994 cfile_css
= css_tryget_online_from_dir(cfile
.file
->f_path
.dentry
->d_parent
,
3995 &memory_cgrp_subsys
);
3997 if (IS_ERR(cfile_css
))
3999 if (cfile_css
!= css
) {
4004 ret
= event
->register_event(memcg
, event
->eventfd
, buf
);
4008 efile
.file
->f_op
->poll(efile
.file
, &event
->pt
);
4010 spin_lock(&memcg
->event_list_lock
);
4011 list_add(&event
->list
, &memcg
->event_list
);
4012 spin_unlock(&memcg
->event_list_lock
);
4024 eventfd_ctx_put(event
->eventfd
);
4033 static struct cftype mem_cgroup_legacy_files
[] = {
4035 .name
= "usage_in_bytes",
4036 .private = MEMFILE_PRIVATE(_MEM
, RES_USAGE
),
4037 .read_u64
= mem_cgroup_read_u64
,
4040 .name
= "max_usage_in_bytes",
4041 .private = MEMFILE_PRIVATE(_MEM
, RES_MAX_USAGE
),
4042 .write
= mem_cgroup_reset
,
4043 .read_u64
= mem_cgroup_read_u64
,
4046 .name
= "limit_in_bytes",
4047 .private = MEMFILE_PRIVATE(_MEM
, RES_LIMIT
),
4048 .write
= mem_cgroup_write
,
4049 .read_u64
= mem_cgroup_read_u64
,
4052 .name
= "soft_limit_in_bytes",
4053 .private = MEMFILE_PRIVATE(_MEM
, RES_SOFT_LIMIT
),
4054 .write
= mem_cgroup_write
,
4055 .read_u64
= mem_cgroup_read_u64
,
4059 .private = MEMFILE_PRIVATE(_MEM
, RES_FAILCNT
),
4060 .write
= mem_cgroup_reset
,
4061 .read_u64
= mem_cgroup_read_u64
,
4065 .seq_show
= memcg_stat_show
,
4068 .name
= "force_empty",
4069 .write
= mem_cgroup_force_empty_write
,
4072 .name
= "use_hierarchy",
4073 .write_u64
= mem_cgroup_hierarchy_write
,
4074 .read_u64
= mem_cgroup_hierarchy_read
,
4077 .name
= "cgroup.event_control", /* XXX: for compat */
4078 .write
= memcg_write_event_control
,
4079 .flags
= CFTYPE_NO_PREFIX
| CFTYPE_WORLD_WRITABLE
,
4082 .name
= "swappiness",
4083 .read_u64
= mem_cgroup_swappiness_read
,
4084 .write_u64
= mem_cgroup_swappiness_write
,
4087 .name
= "move_charge_at_immigrate",
4088 .read_u64
= mem_cgroup_move_charge_read
,
4089 .write_u64
= mem_cgroup_move_charge_write
,
4092 .name
= "oom_control",
4093 .seq_show
= mem_cgroup_oom_control_read
,
4094 .write_u64
= mem_cgroup_oom_control_write
,
4095 .private = MEMFILE_PRIVATE(_OOM_TYPE
, OOM_CONTROL
),
4098 .name
= "pressure_level",
4102 .name
= "numa_stat",
4103 .seq_show
= memcg_numa_stat_show
,
4106 #ifdef CONFIG_MEMCG_KMEM
4108 .name
= "kmem.limit_in_bytes",
4109 .private = MEMFILE_PRIVATE(_KMEM
, RES_LIMIT
),
4110 .write
= mem_cgroup_write
,
4111 .read_u64
= mem_cgroup_read_u64
,
4114 .name
= "kmem.usage_in_bytes",
4115 .private = MEMFILE_PRIVATE(_KMEM
, RES_USAGE
),
4116 .read_u64
= mem_cgroup_read_u64
,
4119 .name
= "kmem.failcnt",
4120 .private = MEMFILE_PRIVATE(_KMEM
, RES_FAILCNT
),
4121 .write
= mem_cgroup_reset
,
4122 .read_u64
= mem_cgroup_read_u64
,
4125 .name
= "kmem.max_usage_in_bytes",
4126 .private = MEMFILE_PRIVATE(_KMEM
, RES_MAX_USAGE
),
4127 .write
= mem_cgroup_reset
,
4128 .read_u64
= mem_cgroup_read_u64
,
4130 #ifdef CONFIG_SLABINFO
4132 .name
= "kmem.slabinfo",
4133 .seq_start
= slab_start
,
4134 .seq_next
= slab_next
,
4135 .seq_stop
= slab_stop
,
4136 .seq_show
= memcg_slab_show
,
4140 { }, /* terminate */
4143 static int alloc_mem_cgroup_per_zone_info(struct mem_cgroup
*memcg
, int node
)
4145 struct mem_cgroup_per_node
*pn
;
4146 struct mem_cgroup_per_zone
*mz
;
4147 int zone
, tmp
= node
;
4149 * This routine is called against possible nodes.
4150 * But it's BUG to call kmalloc() against offline node.
4152 * TODO: this routine can waste much memory for nodes which will
4153 * never be onlined. It's better to use memory hotplug callback
4156 if (!node_state(node
, N_NORMAL_MEMORY
))
4158 pn
= kzalloc_node(sizeof(*pn
), GFP_KERNEL
, tmp
);
4162 for (zone
= 0; zone
< MAX_NR_ZONES
; zone
++) {
4163 mz
= &pn
->zoneinfo
[zone
];
4164 lruvec_init(&mz
->lruvec
);
4165 mz
->usage_in_excess
= 0;
4166 mz
->on_tree
= false;
4169 memcg
->nodeinfo
[node
] = pn
;
4173 static void free_mem_cgroup_per_zone_info(struct mem_cgroup
*memcg
, int node
)
4175 kfree(memcg
->nodeinfo
[node
]);
4178 static struct mem_cgroup
*mem_cgroup_alloc(void)
4180 struct mem_cgroup
*memcg
;
4183 size
= sizeof(struct mem_cgroup
);
4184 size
+= nr_node_ids
* sizeof(struct mem_cgroup_per_node
*);
4186 memcg
= kzalloc(size
, GFP_KERNEL
);
4190 memcg
->stat
= alloc_percpu(struct mem_cgroup_stat_cpu
);
4194 if (memcg_wb_domain_init(memcg
, GFP_KERNEL
))
4200 free_percpu(memcg
->stat
);
4207 * At destroying mem_cgroup, references from swap_cgroup can remain.
4208 * (scanning all at force_empty is too costly...)
4210 * Instead of clearing all references at force_empty, we remember
4211 * the number of reference from swap_cgroup and free mem_cgroup when
4212 * it goes down to 0.
4214 * Removal of cgroup itself succeeds regardless of refs from swap.
4217 static void __mem_cgroup_free(struct mem_cgroup
*memcg
)
4221 mem_cgroup_remove_from_trees(memcg
);
4224 free_mem_cgroup_per_zone_info(memcg
, node
);
4226 free_percpu(memcg
->stat
);
4227 memcg_wb_domain_exit(memcg
);
4232 * Returns the parent mem_cgroup in memcgroup hierarchy with hierarchy enabled.
4234 struct mem_cgroup
*parent_mem_cgroup(struct mem_cgroup
*memcg
)
4236 if (!memcg
->memory
.parent
)
4238 return mem_cgroup_from_counter(memcg
->memory
.parent
, memory
);
4240 EXPORT_SYMBOL(parent_mem_cgroup
);
4242 static struct cgroup_subsys_state
* __ref
4243 mem_cgroup_css_alloc(struct cgroup_subsys_state
*parent_css
)
4245 struct mem_cgroup
*memcg
;
4246 long error
= -ENOMEM
;
4249 memcg
= mem_cgroup_alloc();
4251 return ERR_PTR(error
);
4254 if (alloc_mem_cgroup_per_zone_info(memcg
, node
))
4258 if (parent_css
== NULL
) {
4259 root_mem_cgroup
= memcg
;
4260 page_counter_init(&memcg
->memory
, NULL
);
4261 memcg
->high
= PAGE_COUNTER_MAX
;
4262 memcg
->soft_limit
= PAGE_COUNTER_MAX
;
4263 page_counter_init(&memcg
->memsw
, NULL
);
4264 page_counter_init(&memcg
->kmem
, NULL
);
4267 memcg
->last_scanned_node
= MAX_NUMNODES
;
4268 INIT_LIST_HEAD(&memcg
->oom_notify
);
4269 memcg
->move_charge_at_immigrate
= 0;
4270 mutex_init(&memcg
->thresholds_lock
);
4271 spin_lock_init(&memcg
->move_lock
);
4272 vmpressure_init(&memcg
->vmpressure
);
4273 INIT_LIST_HEAD(&memcg
->event_list
);
4274 spin_lock_init(&memcg
->event_list_lock
);
4275 #ifdef CONFIG_MEMCG_KMEM
4276 memcg
->kmemcg_id
= -1;
4278 #ifdef CONFIG_CGROUP_WRITEBACK
4279 INIT_LIST_HEAD(&memcg
->cgwb_list
);
4284 __mem_cgroup_free(memcg
);
4285 return ERR_PTR(error
);
4289 mem_cgroup_css_online(struct cgroup_subsys_state
*css
)
4291 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
4292 struct mem_cgroup
*parent
= mem_cgroup_from_css(css
->parent
);
4295 if (css
->id
> MEM_CGROUP_ID_MAX
)
4301 mutex_lock(&memcg_create_mutex
);
4303 memcg
->use_hierarchy
= parent
->use_hierarchy
;
4304 memcg
->oom_kill_disable
= parent
->oom_kill_disable
;
4305 memcg
->swappiness
= mem_cgroup_swappiness(parent
);
4307 if (parent
->use_hierarchy
) {
4308 page_counter_init(&memcg
->memory
, &parent
->memory
);
4309 memcg
->high
= PAGE_COUNTER_MAX
;
4310 memcg
->soft_limit
= PAGE_COUNTER_MAX
;
4311 page_counter_init(&memcg
->memsw
, &parent
->memsw
);
4312 page_counter_init(&memcg
->kmem
, &parent
->kmem
);
4315 * No need to take a reference to the parent because cgroup
4316 * core guarantees its existence.
4319 page_counter_init(&memcg
->memory
, NULL
);
4320 memcg
->high
= PAGE_COUNTER_MAX
;
4321 memcg
->soft_limit
= PAGE_COUNTER_MAX
;
4322 page_counter_init(&memcg
->memsw
, NULL
);
4323 page_counter_init(&memcg
->kmem
, NULL
);
4325 * Deeper hierachy with use_hierarchy == false doesn't make
4326 * much sense so let cgroup subsystem know about this
4327 * unfortunate state in our controller.
4329 if (parent
!= root_mem_cgroup
)
4330 memory_cgrp_subsys
.broken_hierarchy
= true;
4332 mutex_unlock(&memcg_create_mutex
);
4334 ret
= memcg_init_kmem(memcg
, &memory_cgrp_subsys
);
4339 * Make sure the memcg is initialized: mem_cgroup_iter()
4340 * orders reading memcg->initialized against its callers
4341 * reading the memcg members.
4343 smp_store_release(&memcg
->initialized
, 1);
4348 static void mem_cgroup_css_offline(struct cgroup_subsys_state
*css
)
4350 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
4351 struct mem_cgroup_event
*event
, *tmp
;
4354 * Unregister events and notify userspace.
4355 * Notify userspace about cgroup removing only after rmdir of cgroup
4356 * directory to avoid race between userspace and kernelspace.
4358 spin_lock(&memcg
->event_list_lock
);
4359 list_for_each_entry_safe(event
, tmp
, &memcg
->event_list
, list
) {
4360 list_del_init(&event
->list
);
4361 schedule_work(&event
->remove
);
4363 spin_unlock(&memcg
->event_list_lock
);
4365 vmpressure_cleanup(&memcg
->vmpressure
);
4367 memcg_deactivate_kmem(memcg
);
4369 wb_memcg_offline(memcg
);
4372 static void mem_cgroup_css_released(struct cgroup_subsys_state
*css
)
4374 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
4376 invalidate_reclaim_iterators(memcg
);
4379 static void mem_cgroup_css_free(struct cgroup_subsys_state
*css
)
4381 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
4383 memcg_destroy_kmem(memcg
);
4384 __mem_cgroup_free(memcg
);
4388 * mem_cgroup_css_reset - reset the states of a mem_cgroup
4389 * @css: the target css
4391 * Reset the states of the mem_cgroup associated with @css. This is
4392 * invoked when the userland requests disabling on the default hierarchy
4393 * but the memcg is pinned through dependency. The memcg should stop
4394 * applying policies and should revert to the vanilla state as it may be
4395 * made visible again.
4397 * The current implementation only resets the essential configurations.
4398 * This needs to be expanded to cover all the visible parts.
4400 static void mem_cgroup_css_reset(struct cgroup_subsys_state
*css
)
4402 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
4404 mem_cgroup_resize_limit(memcg
, PAGE_COUNTER_MAX
);
4405 mem_cgroup_resize_memsw_limit(memcg
, PAGE_COUNTER_MAX
);
4406 memcg_update_kmem_limit(memcg
, PAGE_COUNTER_MAX
);
4408 memcg
->high
= PAGE_COUNTER_MAX
;
4409 memcg
->soft_limit
= PAGE_COUNTER_MAX
;
4410 memcg_wb_domain_size_changed(memcg
);
4414 /* Handlers for move charge at task migration. */
4415 static int mem_cgroup_do_precharge(unsigned long count
)
4419 /* Try a single bulk charge without reclaim first, kswapd may wake */
4420 ret
= try_charge(mc
.to
, GFP_KERNEL
& ~__GFP_DIRECT_RECLAIM
, count
);
4422 mc
.precharge
+= count
;
4426 /* Try charges one by one with reclaim */
4428 ret
= try_charge(mc
.to
, GFP_KERNEL
& ~__GFP_NORETRY
, 1);
4438 * get_mctgt_type - get target type of moving charge
4439 * @vma: the vma the pte to be checked belongs
4440 * @addr: the address corresponding to the pte to be checked
4441 * @ptent: the pte to be checked
4442 * @target: the pointer the target page or swap ent will be stored(can be NULL)
4445 * 0(MC_TARGET_NONE): if the pte is not a target for move charge.
4446 * 1(MC_TARGET_PAGE): if the page corresponding to this pte is a target for
4447 * move charge. if @target is not NULL, the page is stored in target->page
4448 * with extra refcnt got(Callers should handle it).
4449 * 2(MC_TARGET_SWAP): if the swap entry corresponding to this pte is a
4450 * target for charge migration. if @target is not NULL, the entry is stored
4453 * Called with pte lock held.
4460 enum mc_target_type
{
4466 static struct page
*mc_handle_present_pte(struct vm_area_struct
*vma
,
4467 unsigned long addr
, pte_t ptent
)
4469 struct page
*page
= vm_normal_page(vma
, addr
, ptent
);
4471 if (!page
|| !page_mapped(page
))
4473 if (PageAnon(page
)) {
4474 if (!(mc
.flags
& MOVE_ANON
))
4477 if (!(mc
.flags
& MOVE_FILE
))
4480 if (!get_page_unless_zero(page
))
4487 static struct page
*mc_handle_swap_pte(struct vm_area_struct
*vma
,
4488 unsigned long addr
, pte_t ptent
, swp_entry_t
*entry
)
4490 struct page
*page
= NULL
;
4491 swp_entry_t ent
= pte_to_swp_entry(ptent
);
4493 if (!(mc
.flags
& MOVE_ANON
) || non_swap_entry(ent
))
4496 * Because lookup_swap_cache() updates some statistics counter,
4497 * we call find_get_page() with swapper_space directly.
4499 page
= find_get_page(swap_address_space(ent
), ent
.val
);
4500 if (do_swap_account
)
4501 entry
->val
= ent
.val
;
4506 static struct page
*mc_handle_swap_pte(struct vm_area_struct
*vma
,
4507 unsigned long addr
, pte_t ptent
, swp_entry_t
*entry
)
4513 static struct page
*mc_handle_file_pte(struct vm_area_struct
*vma
,
4514 unsigned long addr
, pte_t ptent
, swp_entry_t
*entry
)
4516 struct page
*page
= NULL
;
4517 struct address_space
*mapping
;
4520 if (!vma
->vm_file
) /* anonymous vma */
4522 if (!(mc
.flags
& MOVE_FILE
))
4525 mapping
= vma
->vm_file
->f_mapping
;
4526 pgoff
= linear_page_index(vma
, addr
);
4528 /* page is moved even if it's not RSS of this task(page-faulted). */
4530 /* shmem/tmpfs may report page out on swap: account for that too. */
4531 if (shmem_mapping(mapping
)) {
4532 page
= find_get_entry(mapping
, pgoff
);
4533 if (radix_tree_exceptional_entry(page
)) {
4534 swp_entry_t swp
= radix_to_swp_entry(page
);
4535 if (do_swap_account
)
4537 page
= find_get_page(swap_address_space(swp
), swp
.val
);
4540 page
= find_get_page(mapping
, pgoff
);
4542 page
= find_get_page(mapping
, pgoff
);
4548 * mem_cgroup_move_account - move account of the page
4550 * @nr_pages: number of regular pages (>1 for huge pages)
4551 * @from: mem_cgroup which the page is moved from.
4552 * @to: mem_cgroup which the page is moved to. @from != @to.
4554 * The caller must confirm following.
4555 * - page is not on LRU (isolate_page() is useful.)
4556 * - compound_lock is held when nr_pages > 1
4558 * This function doesn't do "charge" to new cgroup and doesn't do "uncharge"
4561 static int mem_cgroup_move_account(struct page
*page
,
4562 unsigned int nr_pages
,
4563 struct mem_cgroup
*from
,
4564 struct mem_cgroup
*to
)
4566 unsigned long flags
;
4570 VM_BUG_ON(from
== to
);
4571 VM_BUG_ON_PAGE(PageLRU(page
), page
);
4573 * The page is isolated from LRU. So, collapse function
4574 * will not handle this page. But page splitting can happen.
4575 * Do this check under compound_page_lock(). The caller should
4579 if (nr_pages
> 1 && !PageTransHuge(page
))
4583 * Prevent mem_cgroup_replace_page() from looking at
4584 * page->mem_cgroup of its source page while we change it.
4586 if (!trylock_page(page
))
4590 if (page
->mem_cgroup
!= from
)
4593 anon
= PageAnon(page
);
4595 spin_lock_irqsave(&from
->move_lock
, flags
);
4597 if (!anon
&& page_mapped(page
)) {
4598 __this_cpu_sub(from
->stat
->count
[MEM_CGROUP_STAT_FILE_MAPPED
],
4600 __this_cpu_add(to
->stat
->count
[MEM_CGROUP_STAT_FILE_MAPPED
],
4605 * move_lock grabbed above and caller set from->moving_account, so
4606 * mem_cgroup_update_page_stat() will serialize updates to PageDirty.
4607 * So mapping should be stable for dirty pages.
4609 if (!anon
&& PageDirty(page
)) {
4610 struct address_space
*mapping
= page_mapping(page
);
4612 if (mapping_cap_account_dirty(mapping
)) {
4613 __this_cpu_sub(from
->stat
->count
[MEM_CGROUP_STAT_DIRTY
],
4615 __this_cpu_add(to
->stat
->count
[MEM_CGROUP_STAT_DIRTY
],
4620 if (PageWriteback(page
)) {
4621 __this_cpu_sub(from
->stat
->count
[MEM_CGROUP_STAT_WRITEBACK
],
4623 __this_cpu_add(to
->stat
->count
[MEM_CGROUP_STAT_WRITEBACK
],
4628 * It is safe to change page->mem_cgroup here because the page
4629 * is referenced, charged, and isolated - we can't race with
4630 * uncharging, charging, migration, or LRU putback.
4633 /* caller should have done css_get */
4634 page
->mem_cgroup
= to
;
4635 spin_unlock_irqrestore(&from
->move_lock
, flags
);
4639 local_irq_disable();
4640 mem_cgroup_charge_statistics(to
, page
, nr_pages
);
4641 memcg_check_events(to
, page
);
4642 mem_cgroup_charge_statistics(from
, page
, -nr_pages
);
4643 memcg_check_events(from
, page
);
4651 static enum mc_target_type
get_mctgt_type(struct vm_area_struct
*vma
,
4652 unsigned long addr
, pte_t ptent
, union mc_target
*target
)
4654 struct page
*page
= NULL
;
4655 enum mc_target_type ret
= MC_TARGET_NONE
;
4656 swp_entry_t ent
= { .val
= 0 };
4658 if (pte_present(ptent
))
4659 page
= mc_handle_present_pte(vma
, addr
, ptent
);
4660 else if (is_swap_pte(ptent
))
4661 page
= mc_handle_swap_pte(vma
, addr
, ptent
, &ent
);
4662 else if (pte_none(ptent
))
4663 page
= mc_handle_file_pte(vma
, addr
, ptent
, &ent
);
4665 if (!page
&& !ent
.val
)
4669 * Do only loose check w/o serialization.
4670 * mem_cgroup_move_account() checks the page is valid or
4671 * not under LRU exclusion.
4673 if (page
->mem_cgroup
== mc
.from
) {
4674 ret
= MC_TARGET_PAGE
;
4676 target
->page
= page
;
4678 if (!ret
|| !target
)
4681 /* There is a swap entry and a page doesn't exist or isn't charged */
4682 if (ent
.val
&& !ret
&&
4683 mem_cgroup_id(mc
.from
) == lookup_swap_cgroup_id(ent
)) {
4684 ret
= MC_TARGET_SWAP
;
4691 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
4693 * We don't consider swapping or file mapped pages because THP does not
4694 * support them for now.
4695 * Caller should make sure that pmd_trans_huge(pmd) is true.
4697 static enum mc_target_type
get_mctgt_type_thp(struct vm_area_struct
*vma
,
4698 unsigned long addr
, pmd_t pmd
, union mc_target
*target
)
4700 struct page
*page
= NULL
;
4701 enum mc_target_type ret
= MC_TARGET_NONE
;
4703 page
= pmd_page(pmd
);
4704 VM_BUG_ON_PAGE(!page
|| !PageHead(page
), page
);
4705 if (!(mc
.flags
& MOVE_ANON
))
4707 if (page
->mem_cgroup
== mc
.from
) {
4708 ret
= MC_TARGET_PAGE
;
4711 target
->page
= page
;
4717 static inline enum mc_target_type
get_mctgt_type_thp(struct vm_area_struct
*vma
,
4718 unsigned long addr
, pmd_t pmd
, union mc_target
*target
)
4720 return MC_TARGET_NONE
;
4724 static int mem_cgroup_count_precharge_pte_range(pmd_t
*pmd
,
4725 unsigned long addr
, unsigned long end
,
4726 struct mm_walk
*walk
)
4728 struct vm_area_struct
*vma
= walk
->vma
;
4732 if (pmd_trans_huge_lock(pmd
, vma
, &ptl
) == 1) {
4733 if (get_mctgt_type_thp(vma
, addr
, *pmd
, NULL
) == MC_TARGET_PAGE
)
4734 mc
.precharge
+= HPAGE_PMD_NR
;
4739 if (pmd_trans_unstable(pmd
))
4741 pte
= pte_offset_map_lock(vma
->vm_mm
, pmd
, addr
, &ptl
);
4742 for (; addr
!= end
; pte
++, addr
+= PAGE_SIZE
)
4743 if (get_mctgt_type(vma
, addr
, *pte
, NULL
))
4744 mc
.precharge
++; /* increment precharge temporarily */
4745 pte_unmap_unlock(pte
- 1, ptl
);
4751 static unsigned long mem_cgroup_count_precharge(struct mm_struct
*mm
)
4753 unsigned long precharge
;
4755 struct mm_walk mem_cgroup_count_precharge_walk
= {
4756 .pmd_entry
= mem_cgroup_count_precharge_pte_range
,
4759 down_read(&mm
->mmap_sem
);
4760 walk_page_range(0, ~0UL, &mem_cgroup_count_precharge_walk
);
4761 up_read(&mm
->mmap_sem
);
4763 precharge
= mc
.precharge
;
4769 static int mem_cgroup_precharge_mc(struct mm_struct
*mm
)
4771 unsigned long precharge
= mem_cgroup_count_precharge(mm
);
4773 VM_BUG_ON(mc
.moving_task
);
4774 mc
.moving_task
= current
;
4775 return mem_cgroup_do_precharge(precharge
);
4778 /* cancels all extra charges on mc.from and mc.to, and wakes up all waiters. */
4779 static void __mem_cgroup_clear_mc(void)
4781 struct mem_cgroup
*from
= mc
.from
;
4782 struct mem_cgroup
*to
= mc
.to
;
4784 /* we must uncharge all the leftover precharges from mc.to */
4786 cancel_charge(mc
.to
, mc
.precharge
);
4790 * we didn't uncharge from mc.from at mem_cgroup_move_account(), so
4791 * we must uncharge here.
4793 if (mc
.moved_charge
) {
4794 cancel_charge(mc
.from
, mc
.moved_charge
);
4795 mc
.moved_charge
= 0;
4797 /* we must fixup refcnts and charges */
4798 if (mc
.moved_swap
) {
4799 /* uncharge swap account from the old cgroup */
4800 if (!mem_cgroup_is_root(mc
.from
))
4801 page_counter_uncharge(&mc
.from
->memsw
, mc
.moved_swap
);
4804 * we charged both to->memory and to->memsw, so we
4805 * should uncharge to->memory.
4807 if (!mem_cgroup_is_root(mc
.to
))
4808 page_counter_uncharge(&mc
.to
->memory
, mc
.moved_swap
);
4810 css_put_many(&mc
.from
->css
, mc
.moved_swap
);
4812 /* we've already done css_get(mc.to) */
4815 memcg_oom_recover(from
);
4816 memcg_oom_recover(to
);
4817 wake_up_all(&mc
.waitq
);
4820 static void mem_cgroup_clear_mc(void)
4823 * we must clear moving_task before waking up waiters at the end of
4826 mc
.moving_task
= NULL
;
4827 __mem_cgroup_clear_mc();
4828 spin_lock(&mc
.lock
);
4831 spin_unlock(&mc
.lock
);
4834 static int mem_cgroup_can_attach(struct cgroup_taskset
*tset
)
4836 struct cgroup_subsys_state
*css
;
4837 struct mem_cgroup
*memcg
= NULL
; /* unneeded init to make gcc happy */
4838 struct mem_cgroup
*from
;
4839 struct task_struct
*leader
, *p
;
4840 struct mm_struct
*mm
;
4841 unsigned long move_flags
;
4844 /* charge immigration isn't supported on the default hierarchy */
4845 if (cgroup_subsys_on_dfl(memory_cgrp_subsys
))
4849 * Multi-process migrations only happen on the default hierarchy
4850 * where charge immigration is not used. Perform charge
4851 * immigration if @tset contains a leader and whine if there are
4855 cgroup_taskset_for_each_leader(leader
, css
, tset
) {
4858 memcg
= mem_cgroup_from_css(css
);
4864 * We are now commited to this value whatever it is. Changes in this
4865 * tunable will only affect upcoming migrations, not the current one.
4866 * So we need to save it, and keep it going.
4868 move_flags
= READ_ONCE(memcg
->move_charge_at_immigrate
);
4872 from
= mem_cgroup_from_task(p
);
4874 VM_BUG_ON(from
== memcg
);
4876 mm
= get_task_mm(p
);
4879 /* We move charges only when we move a owner of the mm */
4880 if (mm
->owner
== p
) {
4883 VM_BUG_ON(mc
.precharge
);
4884 VM_BUG_ON(mc
.moved_charge
);
4885 VM_BUG_ON(mc
.moved_swap
);
4887 spin_lock(&mc
.lock
);
4890 mc
.flags
= move_flags
;
4891 spin_unlock(&mc
.lock
);
4892 /* We set mc.moving_task later */
4894 ret
= mem_cgroup_precharge_mc(mm
);
4896 mem_cgroup_clear_mc();
4902 static void mem_cgroup_cancel_attach(struct cgroup_taskset
*tset
)
4905 mem_cgroup_clear_mc();
4908 static int mem_cgroup_move_charge_pte_range(pmd_t
*pmd
,
4909 unsigned long addr
, unsigned long end
,
4910 struct mm_walk
*walk
)
4913 struct vm_area_struct
*vma
= walk
->vma
;
4916 enum mc_target_type target_type
;
4917 union mc_target target
;
4921 * We don't take compound_lock() here but no race with splitting thp
4923 * - if pmd_trans_huge_lock() returns 1, the relevant thp is not
4924 * under splitting, which means there's no concurrent thp split,
4925 * - if another thread runs into split_huge_page() just after we
4926 * entered this if-block, the thread must wait for page table lock
4927 * to be unlocked in __split_huge_page_splitting(), where the main
4928 * part of thp split is not executed yet.
4930 if (pmd_trans_huge_lock(pmd
, vma
, &ptl
) == 1) {
4931 if (mc
.precharge
< HPAGE_PMD_NR
) {
4935 target_type
= get_mctgt_type_thp(vma
, addr
, *pmd
, &target
);
4936 if (target_type
== MC_TARGET_PAGE
) {
4938 if (!isolate_lru_page(page
)) {
4939 if (!mem_cgroup_move_account(page
, HPAGE_PMD_NR
,
4941 mc
.precharge
-= HPAGE_PMD_NR
;
4942 mc
.moved_charge
+= HPAGE_PMD_NR
;
4944 putback_lru_page(page
);
4952 if (pmd_trans_unstable(pmd
))
4955 pte
= pte_offset_map_lock(vma
->vm_mm
, pmd
, addr
, &ptl
);
4956 for (; addr
!= end
; addr
+= PAGE_SIZE
) {
4957 pte_t ptent
= *(pte
++);
4963 switch (get_mctgt_type(vma
, addr
, ptent
, &target
)) {
4964 case MC_TARGET_PAGE
:
4966 if (isolate_lru_page(page
))
4968 if (!mem_cgroup_move_account(page
, 1, mc
.from
, mc
.to
)) {
4970 /* we uncharge from mc.from later. */
4973 putback_lru_page(page
);
4974 put
: /* get_mctgt_type() gets the page */
4977 case MC_TARGET_SWAP
:
4979 if (!mem_cgroup_move_swap_account(ent
, mc
.from
, mc
.to
)) {
4981 /* we fixup refcnts and charges later. */
4989 pte_unmap_unlock(pte
- 1, ptl
);
4994 * We have consumed all precharges we got in can_attach().
4995 * We try charge one by one, but don't do any additional
4996 * charges to mc.to if we have failed in charge once in attach()
4999 ret
= mem_cgroup_do_precharge(1);
5007 static void mem_cgroup_move_charge(struct mm_struct
*mm
)
5009 struct mm_walk mem_cgroup_move_charge_walk
= {
5010 .pmd_entry
= mem_cgroup_move_charge_pte_range
,
5014 lru_add_drain_all();
5016 * Signal mem_cgroup_begin_page_stat() to take the memcg's
5017 * move_lock while we're moving its pages to another memcg.
5018 * Then wait for already started RCU-only updates to finish.
5020 atomic_inc(&mc
.from
->moving_account
);
5023 if (unlikely(!down_read_trylock(&mm
->mmap_sem
))) {
5025 * Someone who are holding the mmap_sem might be waiting in
5026 * waitq. So we cancel all extra charges, wake up all waiters,
5027 * and retry. Because we cancel precharges, we might not be able
5028 * to move enough charges, but moving charge is a best-effort
5029 * feature anyway, so it wouldn't be a big problem.
5031 __mem_cgroup_clear_mc();
5036 * When we have consumed all precharges and failed in doing
5037 * additional charge, the page walk just aborts.
5039 walk_page_range(0, ~0UL, &mem_cgroup_move_charge_walk
);
5040 up_read(&mm
->mmap_sem
);
5041 atomic_dec(&mc
.from
->moving_account
);
5044 static void mem_cgroup_move_task(struct cgroup_taskset
*tset
)
5046 struct cgroup_subsys_state
*css
;
5047 struct task_struct
*p
= cgroup_taskset_first(tset
, &css
);
5048 struct mm_struct
*mm
= get_task_mm(p
);
5052 mem_cgroup_move_charge(mm
);
5056 mem_cgroup_clear_mc();
5058 #else /* !CONFIG_MMU */
5059 static int mem_cgroup_can_attach(struct cgroup_taskset
*tset
)
5063 static void mem_cgroup_cancel_attach(struct cgroup_taskset
*tset
)
5066 static void mem_cgroup_move_task(struct cgroup_taskset
*tset
)
5072 * Cgroup retains root cgroups across [un]mount cycles making it necessary
5073 * to verify whether we're attached to the default hierarchy on each mount
5076 static void mem_cgroup_bind(struct cgroup_subsys_state
*root_css
)
5079 * use_hierarchy is forced on the default hierarchy. cgroup core
5080 * guarantees that @root doesn't have any children, so turning it
5081 * on for the root memcg is enough.
5083 if (cgroup_subsys_on_dfl(memory_cgrp_subsys
))
5084 root_mem_cgroup
->use_hierarchy
= true;
5086 root_mem_cgroup
->use_hierarchy
= false;
5089 static u64
memory_current_read(struct cgroup_subsys_state
*css
,
5092 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
5094 return (u64
)page_counter_read(&memcg
->memory
) * PAGE_SIZE
;
5097 static int memory_low_show(struct seq_file
*m
, void *v
)
5099 struct mem_cgroup
*memcg
= mem_cgroup_from_css(seq_css(m
));
5100 unsigned long low
= READ_ONCE(memcg
->low
);
5102 if (low
== PAGE_COUNTER_MAX
)
5103 seq_puts(m
, "max\n");
5105 seq_printf(m
, "%llu\n", (u64
)low
* PAGE_SIZE
);
5110 static ssize_t
memory_low_write(struct kernfs_open_file
*of
,
5111 char *buf
, size_t nbytes
, loff_t off
)
5113 struct mem_cgroup
*memcg
= mem_cgroup_from_css(of_css(of
));
5117 buf
= strstrip(buf
);
5118 err
= page_counter_memparse(buf
, "max", &low
);
5127 static int memory_high_show(struct seq_file
*m
, void *v
)
5129 struct mem_cgroup
*memcg
= mem_cgroup_from_css(seq_css(m
));
5130 unsigned long high
= READ_ONCE(memcg
->high
);
5132 if (high
== PAGE_COUNTER_MAX
)
5133 seq_puts(m
, "max\n");
5135 seq_printf(m
, "%llu\n", (u64
)high
* PAGE_SIZE
);
5140 static ssize_t
memory_high_write(struct kernfs_open_file
*of
,
5141 char *buf
, size_t nbytes
, loff_t off
)
5143 struct mem_cgroup
*memcg
= mem_cgroup_from_css(of_css(of
));
5147 buf
= strstrip(buf
);
5148 err
= page_counter_memparse(buf
, "max", &high
);
5154 memcg_wb_domain_size_changed(memcg
);
5158 static int memory_max_show(struct seq_file
*m
, void *v
)
5160 struct mem_cgroup
*memcg
= mem_cgroup_from_css(seq_css(m
));
5161 unsigned long max
= READ_ONCE(memcg
->memory
.limit
);
5163 if (max
== PAGE_COUNTER_MAX
)
5164 seq_puts(m
, "max\n");
5166 seq_printf(m
, "%llu\n", (u64
)max
* PAGE_SIZE
);
5171 static ssize_t
memory_max_write(struct kernfs_open_file
*of
,
5172 char *buf
, size_t nbytes
, loff_t off
)
5174 struct mem_cgroup
*memcg
= mem_cgroup_from_css(of_css(of
));
5178 buf
= strstrip(buf
);
5179 err
= page_counter_memparse(buf
, "max", &max
);
5183 err
= mem_cgroup_resize_limit(memcg
, max
);
5187 memcg_wb_domain_size_changed(memcg
);
5191 static int memory_events_show(struct seq_file
*m
, void *v
)
5193 struct mem_cgroup
*memcg
= mem_cgroup_from_css(seq_css(m
));
5195 seq_printf(m
, "low %lu\n", mem_cgroup_read_events(memcg
, MEMCG_LOW
));
5196 seq_printf(m
, "high %lu\n", mem_cgroup_read_events(memcg
, MEMCG_HIGH
));
5197 seq_printf(m
, "max %lu\n", mem_cgroup_read_events(memcg
, MEMCG_MAX
));
5198 seq_printf(m
, "oom %lu\n", mem_cgroup_read_events(memcg
, MEMCG_OOM
));
5203 static struct cftype memory_files
[] = {
5206 .flags
= CFTYPE_NOT_ON_ROOT
,
5207 .read_u64
= memory_current_read
,
5211 .flags
= CFTYPE_NOT_ON_ROOT
,
5212 .seq_show
= memory_low_show
,
5213 .write
= memory_low_write
,
5217 .flags
= CFTYPE_NOT_ON_ROOT
,
5218 .seq_show
= memory_high_show
,
5219 .write
= memory_high_write
,
5223 .flags
= CFTYPE_NOT_ON_ROOT
,
5224 .seq_show
= memory_max_show
,
5225 .write
= memory_max_write
,
5229 .flags
= CFTYPE_NOT_ON_ROOT
,
5230 .file_offset
= offsetof(struct mem_cgroup
, events_file
),
5231 .seq_show
= memory_events_show
,
5236 struct cgroup_subsys memory_cgrp_subsys
= {
5237 .css_alloc
= mem_cgroup_css_alloc
,
5238 .css_online
= mem_cgroup_css_online
,
5239 .css_offline
= mem_cgroup_css_offline
,
5240 .css_released
= mem_cgroup_css_released
,
5241 .css_free
= mem_cgroup_css_free
,
5242 .css_reset
= mem_cgroup_css_reset
,
5243 .can_attach
= mem_cgroup_can_attach
,
5244 .cancel_attach
= mem_cgroup_cancel_attach
,
5245 .attach
= mem_cgroup_move_task
,
5246 .bind
= mem_cgroup_bind
,
5247 .dfl_cftypes
= memory_files
,
5248 .legacy_cftypes
= mem_cgroup_legacy_files
,
5253 * mem_cgroup_low - check if memory consumption is below the normal range
5254 * @root: the highest ancestor to consider
5255 * @memcg: the memory cgroup to check
5257 * Returns %true if memory consumption of @memcg, and that of all
5258 * configurable ancestors up to @root, is below the normal range.
5260 bool mem_cgroup_low(struct mem_cgroup
*root
, struct mem_cgroup
*memcg
)
5262 if (mem_cgroup_disabled())
5266 * The toplevel group doesn't have a configurable range, so
5267 * it's never low when looked at directly, and it is not
5268 * considered an ancestor when assessing the hierarchy.
5271 if (memcg
== root_mem_cgroup
)
5274 if (page_counter_read(&memcg
->memory
) >= memcg
->low
)
5277 while (memcg
!= root
) {
5278 memcg
= parent_mem_cgroup(memcg
);
5280 if (memcg
== root_mem_cgroup
)
5283 if (page_counter_read(&memcg
->memory
) >= memcg
->low
)
5290 * mem_cgroup_try_charge - try charging a page
5291 * @page: page to charge
5292 * @mm: mm context of the victim
5293 * @gfp_mask: reclaim mode
5294 * @memcgp: charged memcg return
5296 * Try to charge @page to the memcg that @mm belongs to, reclaiming
5297 * pages according to @gfp_mask if necessary.
5299 * Returns 0 on success, with *@memcgp pointing to the charged memcg.
5300 * Otherwise, an error code is returned.
5302 * After page->mapping has been set up, the caller must finalize the
5303 * charge with mem_cgroup_commit_charge(). Or abort the transaction
5304 * with mem_cgroup_cancel_charge() in case page instantiation fails.
5306 int mem_cgroup_try_charge(struct page
*page
, struct mm_struct
*mm
,
5307 gfp_t gfp_mask
, struct mem_cgroup
**memcgp
)
5309 struct mem_cgroup
*memcg
= NULL
;
5310 unsigned int nr_pages
= 1;
5313 if (mem_cgroup_disabled())
5316 if (PageSwapCache(page
)) {
5318 * Every swap fault against a single page tries to charge the
5319 * page, bail as early as possible. shmem_unuse() encounters
5320 * already charged pages, too. The USED bit is protected by
5321 * the page lock, which serializes swap cache removal, which
5322 * in turn serializes uncharging.
5324 VM_BUG_ON_PAGE(!PageLocked(page
), page
);
5325 if (page
->mem_cgroup
)
5328 if (do_swap_account
) {
5329 swp_entry_t ent
= { .val
= page_private(page
), };
5330 unsigned short id
= lookup_swap_cgroup_id(ent
);
5333 memcg
= mem_cgroup_from_id(id
);
5334 if (memcg
&& !css_tryget_online(&memcg
->css
))
5340 if (PageTransHuge(page
)) {
5341 nr_pages
<<= compound_order(page
);
5342 VM_BUG_ON_PAGE(!PageTransHuge(page
), page
);
5346 memcg
= get_mem_cgroup_from_mm(mm
);
5348 ret
= try_charge(memcg
, gfp_mask
, nr_pages
);
5350 css_put(&memcg
->css
);
5357 * mem_cgroup_commit_charge - commit a page charge
5358 * @page: page to charge
5359 * @memcg: memcg to charge the page to
5360 * @lrucare: page might be on LRU already
5362 * Finalize a charge transaction started by mem_cgroup_try_charge(),
5363 * after page->mapping has been set up. This must happen atomically
5364 * as part of the page instantiation, i.e. under the page table lock
5365 * for anonymous pages, under the page lock for page and swap cache.
5367 * In addition, the page must not be on the LRU during the commit, to
5368 * prevent racing with task migration. If it might be, use @lrucare.
5370 * Use mem_cgroup_cancel_charge() to cancel the transaction instead.
5372 void mem_cgroup_commit_charge(struct page
*page
, struct mem_cgroup
*memcg
,
5375 unsigned int nr_pages
= 1;
5377 VM_BUG_ON_PAGE(!page
->mapping
, page
);
5378 VM_BUG_ON_PAGE(PageLRU(page
) && !lrucare
, page
);
5380 if (mem_cgroup_disabled())
5383 * Swap faults will attempt to charge the same page multiple
5384 * times. But reuse_swap_page() might have removed the page
5385 * from swapcache already, so we can't check PageSwapCache().
5390 commit_charge(page
, memcg
, lrucare
);
5392 if (PageTransHuge(page
)) {
5393 nr_pages
<<= compound_order(page
);
5394 VM_BUG_ON_PAGE(!PageTransHuge(page
), page
);
5397 local_irq_disable();
5398 mem_cgroup_charge_statistics(memcg
, page
, nr_pages
);
5399 memcg_check_events(memcg
, page
);
5402 if (do_swap_account
&& PageSwapCache(page
)) {
5403 swp_entry_t entry
= { .val
= page_private(page
) };
5405 * The swap entry might not get freed for a long time,
5406 * let's not wait for it. The page already received a
5407 * memory+swap charge, drop the swap entry duplicate.
5409 mem_cgroup_uncharge_swap(entry
);
5414 * mem_cgroup_cancel_charge - cancel a page charge
5415 * @page: page to charge
5416 * @memcg: memcg to charge the page to
5418 * Cancel a charge transaction started by mem_cgroup_try_charge().
5420 void mem_cgroup_cancel_charge(struct page
*page
, struct mem_cgroup
*memcg
)
5422 unsigned int nr_pages
= 1;
5424 if (mem_cgroup_disabled())
5427 * Swap faults will attempt to charge the same page multiple
5428 * times. But reuse_swap_page() might have removed the page
5429 * from swapcache already, so we can't check PageSwapCache().
5434 if (PageTransHuge(page
)) {
5435 nr_pages
<<= compound_order(page
);
5436 VM_BUG_ON_PAGE(!PageTransHuge(page
), page
);
5439 cancel_charge(memcg
, nr_pages
);
5442 static void uncharge_batch(struct mem_cgroup
*memcg
, unsigned long pgpgout
,
5443 unsigned long nr_anon
, unsigned long nr_file
,
5444 unsigned long nr_huge
, struct page
*dummy_page
)
5446 unsigned long nr_pages
= nr_anon
+ nr_file
;
5447 unsigned long flags
;
5449 if (!mem_cgroup_is_root(memcg
)) {
5450 page_counter_uncharge(&memcg
->memory
, nr_pages
);
5451 if (do_swap_account
)
5452 page_counter_uncharge(&memcg
->memsw
, nr_pages
);
5453 memcg_oom_recover(memcg
);
5456 local_irq_save(flags
);
5457 __this_cpu_sub(memcg
->stat
->count
[MEM_CGROUP_STAT_RSS
], nr_anon
);
5458 __this_cpu_sub(memcg
->stat
->count
[MEM_CGROUP_STAT_CACHE
], nr_file
);
5459 __this_cpu_sub(memcg
->stat
->count
[MEM_CGROUP_STAT_RSS_HUGE
], nr_huge
);
5460 __this_cpu_add(memcg
->stat
->events
[MEM_CGROUP_EVENTS_PGPGOUT
], pgpgout
);
5461 __this_cpu_add(memcg
->stat
->nr_page_events
, nr_pages
);
5462 memcg_check_events(memcg
, dummy_page
);
5463 local_irq_restore(flags
);
5465 if (!mem_cgroup_is_root(memcg
))
5466 css_put_many(&memcg
->css
, nr_pages
);
5469 static void uncharge_list(struct list_head
*page_list
)
5471 struct mem_cgroup
*memcg
= NULL
;
5472 unsigned long nr_anon
= 0;
5473 unsigned long nr_file
= 0;
5474 unsigned long nr_huge
= 0;
5475 unsigned long pgpgout
= 0;
5476 struct list_head
*next
;
5479 next
= page_list
->next
;
5481 unsigned int nr_pages
= 1;
5483 page
= list_entry(next
, struct page
, lru
);
5484 next
= page
->lru
.next
;
5486 VM_BUG_ON_PAGE(PageLRU(page
), page
);
5487 VM_BUG_ON_PAGE(page_count(page
), page
);
5489 if (!page
->mem_cgroup
)
5493 * Nobody should be changing or seriously looking at
5494 * page->mem_cgroup at this point, we have fully
5495 * exclusive access to the page.
5498 if (memcg
!= page
->mem_cgroup
) {
5500 uncharge_batch(memcg
, pgpgout
, nr_anon
, nr_file
,
5502 pgpgout
= nr_anon
= nr_file
= nr_huge
= 0;
5504 memcg
= page
->mem_cgroup
;
5507 if (PageTransHuge(page
)) {
5508 nr_pages
<<= compound_order(page
);
5509 VM_BUG_ON_PAGE(!PageTransHuge(page
), page
);
5510 nr_huge
+= nr_pages
;
5514 nr_anon
+= nr_pages
;
5516 nr_file
+= nr_pages
;
5518 page
->mem_cgroup
= NULL
;
5521 } while (next
!= page_list
);
5524 uncharge_batch(memcg
, pgpgout
, nr_anon
, nr_file
,
5529 * mem_cgroup_uncharge - uncharge a page
5530 * @page: page to uncharge
5532 * Uncharge a page previously charged with mem_cgroup_try_charge() and
5533 * mem_cgroup_commit_charge().
5535 void mem_cgroup_uncharge(struct page
*page
)
5537 if (mem_cgroup_disabled())
5540 /* Don't touch page->lru of any random page, pre-check: */
5541 if (!page
->mem_cgroup
)
5544 INIT_LIST_HEAD(&page
->lru
);
5545 uncharge_list(&page
->lru
);
5549 * mem_cgroup_uncharge_list - uncharge a list of page
5550 * @page_list: list of pages to uncharge
5552 * Uncharge a list of pages previously charged with
5553 * mem_cgroup_try_charge() and mem_cgroup_commit_charge().
5555 void mem_cgroup_uncharge_list(struct list_head
*page_list
)
5557 if (mem_cgroup_disabled())
5560 if (!list_empty(page_list
))
5561 uncharge_list(page_list
);
5565 * mem_cgroup_replace_page - migrate a charge to another page
5566 * @oldpage: currently charged page
5567 * @newpage: page to transfer the charge to
5569 * Migrate the charge from @oldpage to @newpage.
5571 * Both pages must be locked, @newpage->mapping must be set up.
5572 * Either or both pages might be on the LRU already.
5574 void mem_cgroup_replace_page(struct page
*oldpage
, struct page
*newpage
)
5576 struct mem_cgroup
*memcg
;
5579 VM_BUG_ON_PAGE(!PageLocked(oldpage
), oldpage
);
5580 VM_BUG_ON_PAGE(!PageLocked(newpage
), newpage
);
5581 VM_BUG_ON_PAGE(PageAnon(oldpage
) != PageAnon(newpage
), newpage
);
5582 VM_BUG_ON_PAGE(PageTransHuge(oldpage
) != PageTransHuge(newpage
),
5585 if (mem_cgroup_disabled())
5588 /* Page cache replacement: new page already charged? */
5589 if (newpage
->mem_cgroup
)
5592 /* Swapcache readahead pages can get replaced before being charged */
5593 memcg
= oldpage
->mem_cgroup
;
5597 lock_page_lru(oldpage
, &isolated
);
5598 oldpage
->mem_cgroup
= NULL
;
5599 unlock_page_lru(oldpage
, isolated
);
5601 commit_charge(newpage
, memcg
, true);
5605 * subsys_initcall() for memory controller.
5607 * Some parts like hotcpu_notifier() have to be initialized from this context
5608 * because of lock dependencies (cgroup_lock -> cpu hotplug) but basically
5609 * everything that doesn't depend on a specific mem_cgroup structure should
5610 * be initialized from here.
5612 static int __init
mem_cgroup_init(void)
5616 hotcpu_notifier(memcg_cpu_hotplug_callback
, 0);
5618 for_each_possible_cpu(cpu
)
5619 INIT_WORK(&per_cpu_ptr(&memcg_stock
, cpu
)->work
,
5622 for_each_node(node
) {
5623 struct mem_cgroup_tree_per_node
*rtpn
;
5626 rtpn
= kzalloc_node(sizeof(*rtpn
), GFP_KERNEL
,
5627 node_online(node
) ? node
: NUMA_NO_NODE
);
5629 for (zone
= 0; zone
< MAX_NR_ZONES
; zone
++) {
5630 struct mem_cgroup_tree_per_zone
*rtpz
;
5632 rtpz
= &rtpn
->rb_tree_per_zone
[zone
];
5633 rtpz
->rb_root
= RB_ROOT
;
5634 spin_lock_init(&rtpz
->lock
);
5636 soft_limit_tree
.rb_tree_per_node
[node
] = rtpn
;
5641 subsys_initcall(mem_cgroup_init
);
5643 #ifdef CONFIG_MEMCG_SWAP
5645 * mem_cgroup_swapout - transfer a memsw charge to swap
5646 * @page: page whose memsw charge to transfer
5647 * @entry: swap entry to move the charge to
5649 * Transfer the memsw charge of @page to @entry.
5651 void mem_cgroup_swapout(struct page
*page
, swp_entry_t entry
)
5653 struct mem_cgroup
*memcg
;
5654 unsigned short oldid
;
5656 VM_BUG_ON_PAGE(PageLRU(page
), page
);
5657 VM_BUG_ON_PAGE(page_count(page
), page
);
5659 if (!do_swap_account
)
5662 memcg
= page
->mem_cgroup
;
5664 /* Readahead page, never charged */
5668 oldid
= swap_cgroup_record(entry
, mem_cgroup_id(memcg
));
5669 VM_BUG_ON_PAGE(oldid
, page
);
5670 mem_cgroup_swap_statistics(memcg
, true);
5672 page
->mem_cgroup
= NULL
;
5674 if (!mem_cgroup_is_root(memcg
))
5675 page_counter_uncharge(&memcg
->memory
, 1);
5678 * Interrupts should be disabled here because the caller holds the
5679 * mapping->tree_lock lock which is taken with interrupts-off. It is
5680 * important here to have the interrupts disabled because it is the
5681 * only synchronisation we have for udpating the per-CPU variables.
5683 VM_BUG_ON(!irqs_disabled());
5684 mem_cgroup_charge_statistics(memcg
, page
, -1);
5685 memcg_check_events(memcg
, page
);
5689 * mem_cgroup_uncharge_swap - uncharge a swap entry
5690 * @entry: swap entry to uncharge
5692 * Drop the memsw charge associated with @entry.
5694 void mem_cgroup_uncharge_swap(swp_entry_t entry
)
5696 struct mem_cgroup
*memcg
;
5699 if (!do_swap_account
)
5702 id
= swap_cgroup_record(entry
, 0);
5704 memcg
= mem_cgroup_from_id(id
);
5706 if (!mem_cgroup_is_root(memcg
))
5707 page_counter_uncharge(&memcg
->memsw
, 1);
5708 mem_cgroup_swap_statistics(memcg
, false);
5709 css_put(&memcg
->css
);
5714 /* for remember boot option*/
5715 #ifdef CONFIG_MEMCG_SWAP_ENABLED
5716 static int really_do_swap_account __initdata
= 1;
5718 static int really_do_swap_account __initdata
;
5721 static int __init
enable_swap_account(char *s
)
5723 if (!strcmp(s
, "1"))
5724 really_do_swap_account
= 1;
5725 else if (!strcmp(s
, "0"))
5726 really_do_swap_account
= 0;
5729 __setup("swapaccount=", enable_swap_account
);
5731 static struct cftype memsw_cgroup_files
[] = {
5733 .name
= "memsw.usage_in_bytes",
5734 .private = MEMFILE_PRIVATE(_MEMSWAP
, RES_USAGE
),
5735 .read_u64
= mem_cgroup_read_u64
,
5738 .name
= "memsw.max_usage_in_bytes",
5739 .private = MEMFILE_PRIVATE(_MEMSWAP
, RES_MAX_USAGE
),
5740 .write
= mem_cgroup_reset
,
5741 .read_u64
= mem_cgroup_read_u64
,
5744 .name
= "memsw.limit_in_bytes",
5745 .private = MEMFILE_PRIVATE(_MEMSWAP
, RES_LIMIT
),
5746 .write
= mem_cgroup_write
,
5747 .read_u64
= mem_cgroup_read_u64
,
5750 .name
= "memsw.failcnt",
5751 .private = MEMFILE_PRIVATE(_MEMSWAP
, RES_FAILCNT
),
5752 .write
= mem_cgroup_reset
,
5753 .read_u64
= mem_cgroup_read_u64
,
5755 { }, /* terminate */
5758 static int __init
mem_cgroup_swap_init(void)
5760 if (!mem_cgroup_disabled() && really_do_swap_account
) {
5761 do_swap_account
= 1;
5762 WARN_ON(cgroup_add_legacy_cftypes(&memory_cgrp_subsys
,
5763 memsw_cgroup_files
));
5767 subsys_initcall(mem_cgroup_swap_init
);
5769 #endif /* CONFIG_MEMCG_SWAP */