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>
71 #include <asm/uaccess.h>
73 #include <trace/events/vmscan.h>
75 struct cgroup_subsys memory_cgrp_subsys __read_mostly
;
76 EXPORT_SYMBOL(memory_cgrp_subsys
);
78 struct mem_cgroup
*root_mem_cgroup __read_mostly
;
80 #define MEM_CGROUP_RECLAIM_RETRIES 5
82 /* Socket memory accounting disabled? */
83 static bool cgroup_memory_nosocket
;
85 /* Kernel memory accounting disabled? */
86 static bool cgroup_memory_nokmem
;
88 /* Whether the swap controller is active */
89 #ifdef CONFIG_MEMCG_SWAP
90 int do_swap_account __read_mostly
;
92 #define do_swap_account 0
95 /* Whether legacy memory+swap accounting is active */
96 static bool do_memsw_account(void)
98 return !cgroup_subsys_on_dfl(memory_cgrp_subsys
) && do_swap_account
;
101 static const char * const mem_cgroup_stat_names
[] = {
111 static const char * const mem_cgroup_events_names
[] = {
118 static const char * const mem_cgroup_lru_names
[] = {
126 #define THRESHOLDS_EVENTS_TARGET 128
127 #define SOFTLIMIT_EVENTS_TARGET 1024
128 #define NUMAINFO_EVENTS_TARGET 1024
131 * Cgroups above their limits are maintained in a RB-Tree, independent of
132 * their hierarchy representation
135 struct mem_cgroup_tree_per_zone
{
136 struct rb_root rb_root
;
140 struct mem_cgroup_tree_per_node
{
141 struct mem_cgroup_tree_per_zone rb_tree_per_zone
[MAX_NR_ZONES
];
144 struct mem_cgroup_tree
{
145 struct mem_cgroup_tree_per_node
*rb_tree_per_node
[MAX_NUMNODES
];
148 static struct mem_cgroup_tree soft_limit_tree __read_mostly
;
151 struct mem_cgroup_eventfd_list
{
152 struct list_head list
;
153 struct eventfd_ctx
*eventfd
;
157 * cgroup_event represents events which userspace want to receive.
159 struct mem_cgroup_event
{
161 * memcg which the event belongs to.
163 struct mem_cgroup
*memcg
;
165 * eventfd to signal userspace about the event.
167 struct eventfd_ctx
*eventfd
;
169 * Each of these stored in a list by the cgroup.
171 struct list_head list
;
173 * register_event() callback will be used to add new userspace
174 * waiter for changes related to this event. Use eventfd_signal()
175 * on eventfd to send notification to userspace.
177 int (*register_event
)(struct mem_cgroup
*memcg
,
178 struct eventfd_ctx
*eventfd
, const char *args
);
180 * unregister_event() callback will be called when userspace closes
181 * the eventfd or on cgroup removing. This callback must be set,
182 * if you want provide notification functionality.
184 void (*unregister_event
)(struct mem_cgroup
*memcg
,
185 struct eventfd_ctx
*eventfd
);
187 * All fields below needed to unregister event when
188 * userspace closes eventfd.
191 wait_queue_head_t
*wqh
;
193 struct work_struct remove
;
196 static void mem_cgroup_threshold(struct mem_cgroup
*memcg
);
197 static void mem_cgroup_oom_notify(struct mem_cgroup
*memcg
);
199 /* Stuffs for move charges at task migration. */
201 * Types of charges to be moved.
203 #define MOVE_ANON 0x1U
204 #define MOVE_FILE 0x2U
205 #define MOVE_MASK (MOVE_ANON | MOVE_FILE)
207 /* "mc" and its members are protected by cgroup_mutex */
208 static struct move_charge_struct
{
209 spinlock_t lock
; /* for from, to */
210 struct mm_struct
*mm
;
211 struct mem_cgroup
*from
;
212 struct mem_cgroup
*to
;
214 unsigned long precharge
;
215 unsigned long moved_charge
;
216 unsigned long moved_swap
;
217 struct task_struct
*moving_task
; /* a task moving charges */
218 wait_queue_head_t waitq
; /* a waitq for other context */
220 .lock
= __SPIN_LOCK_UNLOCKED(mc
.lock
),
221 .waitq
= __WAIT_QUEUE_HEAD_INITIALIZER(mc
.waitq
),
225 * Maximum loops in mem_cgroup_hierarchical_reclaim(), used for soft
226 * limit reclaim to prevent infinite loops, if they ever occur.
228 #define MEM_CGROUP_MAX_RECLAIM_LOOPS 100
229 #define MEM_CGROUP_MAX_SOFT_LIMIT_RECLAIM_LOOPS 2
232 MEM_CGROUP_CHARGE_TYPE_CACHE
= 0,
233 MEM_CGROUP_CHARGE_TYPE_ANON
,
234 MEM_CGROUP_CHARGE_TYPE_SWAPOUT
, /* for accounting swapcache */
235 MEM_CGROUP_CHARGE_TYPE_DROP
, /* a page was unused swap cache */
239 /* for encoding cft->private value on file */
248 #define MEMFILE_PRIVATE(x, val) ((x) << 16 | (val))
249 #define MEMFILE_TYPE(val) ((val) >> 16 & 0xffff)
250 #define MEMFILE_ATTR(val) ((val) & 0xffff)
251 /* Used for OOM nofiier */
252 #define OOM_CONTROL (0)
254 /* Some nice accessors for the vmpressure. */
255 struct vmpressure
*memcg_to_vmpressure(struct mem_cgroup
*memcg
)
258 memcg
= root_mem_cgroup
;
259 return &memcg
->vmpressure
;
262 struct cgroup_subsys_state
*vmpressure_to_css(struct vmpressure
*vmpr
)
264 return &container_of(vmpr
, struct mem_cgroup
, vmpressure
)->css
;
267 static inline bool mem_cgroup_is_root(struct mem_cgroup
*memcg
)
269 return (memcg
== root_mem_cgroup
);
274 * This will be the memcg's index in each cache's ->memcg_params.memcg_caches.
275 * The main reason for not using cgroup id for this:
276 * this works better in sparse environments, where we have a lot of memcgs,
277 * but only a few kmem-limited. Or also, if we have, for instance, 200
278 * memcgs, and none but the 200th is kmem-limited, we'd have to have a
279 * 200 entry array for that.
281 * The current size of the caches array is stored in memcg_nr_cache_ids. It
282 * will double each time we have to increase it.
284 static DEFINE_IDA(memcg_cache_ida
);
285 int memcg_nr_cache_ids
;
287 /* Protects memcg_nr_cache_ids */
288 static DECLARE_RWSEM(memcg_cache_ids_sem
);
290 void memcg_get_cache_ids(void)
292 down_read(&memcg_cache_ids_sem
);
295 void memcg_put_cache_ids(void)
297 up_read(&memcg_cache_ids_sem
);
301 * MIN_SIZE is different than 1, because we would like to avoid going through
302 * the alloc/free process all the time. In a small machine, 4 kmem-limited
303 * cgroups is a reasonable guess. In the future, it could be a parameter or
304 * tunable, but that is strictly not necessary.
306 * MAX_SIZE should be as large as the number of cgrp_ids. Ideally, we could get
307 * this constant directly from cgroup, but it is understandable that this is
308 * better kept as an internal representation in cgroup.c. In any case, the
309 * cgrp_id space is not getting any smaller, and we don't have to necessarily
310 * increase ours as well if it increases.
312 #define MEMCG_CACHES_MIN_SIZE 4
313 #define MEMCG_CACHES_MAX_SIZE MEM_CGROUP_ID_MAX
316 * A lot of the calls to the cache allocation functions are expected to be
317 * inlined by the compiler. Since the calls to memcg_kmem_get_cache are
318 * conditional to this static branch, we'll have to allow modules that does
319 * kmem_cache_alloc and the such to see this symbol as well
321 DEFINE_STATIC_KEY_FALSE(memcg_kmem_enabled_key
);
322 EXPORT_SYMBOL(memcg_kmem_enabled_key
);
324 #endif /* !CONFIG_SLOB */
326 static struct mem_cgroup_per_zone
*
327 mem_cgroup_zone_zoneinfo(struct mem_cgroup
*memcg
, struct zone
*zone
)
329 int nid
= zone_to_nid(zone
);
330 int zid
= zone_idx(zone
);
332 return &memcg
->nodeinfo
[nid
]->zoneinfo
[zid
];
336 * mem_cgroup_css_from_page - css of the memcg associated with a page
337 * @page: page of interest
339 * If memcg is bound to the default hierarchy, css of the memcg associated
340 * with @page is returned. The returned css remains associated with @page
341 * until it is released.
343 * If memcg is bound to a traditional hierarchy, the css of root_mem_cgroup
346 struct cgroup_subsys_state
*mem_cgroup_css_from_page(struct page
*page
)
348 struct mem_cgroup
*memcg
;
350 memcg
= page
->mem_cgroup
;
352 if (!memcg
|| !cgroup_subsys_on_dfl(memory_cgrp_subsys
))
353 memcg
= root_mem_cgroup
;
359 * page_cgroup_ino - return inode number of the memcg a page is charged to
362 * Look up the closest online ancestor of the memory cgroup @page is charged to
363 * and return its inode number or 0 if @page is not charged to any cgroup. It
364 * is safe to call this function without holding a reference to @page.
366 * Note, this function is inherently racy, because there is nothing to prevent
367 * the cgroup inode from getting torn down and potentially reallocated a moment
368 * after page_cgroup_ino() returns, so it only should be used by callers that
369 * do not care (such as procfs interfaces).
371 ino_t
page_cgroup_ino(struct page
*page
)
373 struct mem_cgroup
*memcg
;
374 unsigned long ino
= 0;
377 memcg
= READ_ONCE(page
->mem_cgroup
);
378 while (memcg
&& !(memcg
->css
.flags
& CSS_ONLINE
))
379 memcg
= parent_mem_cgroup(memcg
);
381 ino
= cgroup_ino(memcg
->css
.cgroup
);
386 static struct mem_cgroup_per_zone
*
387 mem_cgroup_page_zoneinfo(struct mem_cgroup
*memcg
, struct page
*page
)
389 int nid
= page_to_nid(page
);
390 int zid
= page_zonenum(page
);
392 return &memcg
->nodeinfo
[nid
]->zoneinfo
[zid
];
395 static struct mem_cgroup_tree_per_zone
*
396 soft_limit_tree_node_zone(int nid
, int zid
)
398 return &soft_limit_tree
.rb_tree_per_node
[nid
]->rb_tree_per_zone
[zid
];
401 static struct mem_cgroup_tree_per_zone
*
402 soft_limit_tree_from_page(struct page
*page
)
404 int nid
= page_to_nid(page
);
405 int zid
= page_zonenum(page
);
407 return &soft_limit_tree
.rb_tree_per_node
[nid
]->rb_tree_per_zone
[zid
];
410 static void __mem_cgroup_insert_exceeded(struct mem_cgroup_per_zone
*mz
,
411 struct mem_cgroup_tree_per_zone
*mctz
,
412 unsigned long new_usage_in_excess
)
414 struct rb_node
**p
= &mctz
->rb_root
.rb_node
;
415 struct rb_node
*parent
= NULL
;
416 struct mem_cgroup_per_zone
*mz_node
;
421 mz
->usage_in_excess
= new_usage_in_excess
;
422 if (!mz
->usage_in_excess
)
426 mz_node
= rb_entry(parent
, struct mem_cgroup_per_zone
,
428 if (mz
->usage_in_excess
< mz_node
->usage_in_excess
)
431 * We can't avoid mem cgroups that are over their soft
432 * limit by the same amount
434 else if (mz
->usage_in_excess
>= mz_node
->usage_in_excess
)
437 rb_link_node(&mz
->tree_node
, parent
, p
);
438 rb_insert_color(&mz
->tree_node
, &mctz
->rb_root
);
442 static void __mem_cgroup_remove_exceeded(struct mem_cgroup_per_zone
*mz
,
443 struct mem_cgroup_tree_per_zone
*mctz
)
447 rb_erase(&mz
->tree_node
, &mctz
->rb_root
);
451 static void mem_cgroup_remove_exceeded(struct mem_cgroup_per_zone
*mz
,
452 struct mem_cgroup_tree_per_zone
*mctz
)
456 spin_lock_irqsave(&mctz
->lock
, flags
);
457 __mem_cgroup_remove_exceeded(mz
, mctz
);
458 spin_unlock_irqrestore(&mctz
->lock
, flags
);
461 static unsigned long soft_limit_excess(struct mem_cgroup
*memcg
)
463 unsigned long nr_pages
= page_counter_read(&memcg
->memory
);
464 unsigned long soft_limit
= READ_ONCE(memcg
->soft_limit
);
465 unsigned long excess
= 0;
467 if (nr_pages
> soft_limit
)
468 excess
= nr_pages
- soft_limit
;
473 static void mem_cgroup_update_tree(struct mem_cgroup
*memcg
, struct page
*page
)
475 unsigned long excess
;
476 struct mem_cgroup_per_zone
*mz
;
477 struct mem_cgroup_tree_per_zone
*mctz
;
479 mctz
= soft_limit_tree_from_page(page
);
481 * Necessary to update all ancestors when hierarchy is used.
482 * because their event counter is not touched.
484 for (; memcg
; memcg
= parent_mem_cgroup(memcg
)) {
485 mz
= mem_cgroup_page_zoneinfo(memcg
, page
);
486 excess
= soft_limit_excess(memcg
);
488 * We have to update the tree if mz is on RB-tree or
489 * mem is over its softlimit.
491 if (excess
|| mz
->on_tree
) {
494 spin_lock_irqsave(&mctz
->lock
, flags
);
495 /* if on-tree, remove it */
497 __mem_cgroup_remove_exceeded(mz
, mctz
);
499 * Insert again. mz->usage_in_excess will be updated.
500 * If excess is 0, no tree ops.
502 __mem_cgroup_insert_exceeded(mz
, mctz
, excess
);
503 spin_unlock_irqrestore(&mctz
->lock
, flags
);
508 static void mem_cgroup_remove_from_trees(struct mem_cgroup
*memcg
)
510 struct mem_cgroup_tree_per_zone
*mctz
;
511 struct mem_cgroup_per_zone
*mz
;
515 for (zid
= 0; zid
< MAX_NR_ZONES
; zid
++) {
516 mz
= &memcg
->nodeinfo
[nid
]->zoneinfo
[zid
];
517 mctz
= soft_limit_tree_node_zone(nid
, zid
);
518 mem_cgroup_remove_exceeded(mz
, mctz
);
523 static struct mem_cgroup_per_zone
*
524 __mem_cgroup_largest_soft_limit_node(struct mem_cgroup_tree_per_zone
*mctz
)
526 struct rb_node
*rightmost
= NULL
;
527 struct mem_cgroup_per_zone
*mz
;
531 rightmost
= rb_last(&mctz
->rb_root
);
533 goto done
; /* Nothing to reclaim from */
535 mz
= rb_entry(rightmost
, struct mem_cgroup_per_zone
, tree_node
);
537 * Remove the node now but someone else can add it back,
538 * we will to add it back at the end of reclaim to its correct
539 * position in the tree.
541 __mem_cgroup_remove_exceeded(mz
, mctz
);
542 if (!soft_limit_excess(mz
->memcg
) ||
543 !css_tryget_online(&mz
->memcg
->css
))
549 static struct mem_cgroup_per_zone
*
550 mem_cgroup_largest_soft_limit_node(struct mem_cgroup_tree_per_zone
*mctz
)
552 struct mem_cgroup_per_zone
*mz
;
554 spin_lock_irq(&mctz
->lock
);
555 mz
= __mem_cgroup_largest_soft_limit_node(mctz
);
556 spin_unlock_irq(&mctz
->lock
);
561 * Return page count for single (non recursive) @memcg.
563 * Implementation Note: reading percpu statistics for memcg.
565 * Both of vmstat[] and percpu_counter has threshold and do periodic
566 * synchronization to implement "quick" read. There are trade-off between
567 * reading cost and precision of value. Then, we may have a chance to implement
568 * a periodic synchronization of counter in memcg's counter.
570 * But this _read() function is used for user interface now. The user accounts
571 * memory usage by memory cgroup and he _always_ requires exact value because
572 * he accounts memory. Even if we provide quick-and-fuzzy read, we always
573 * have to visit all online cpus and make sum. So, for now, unnecessary
574 * synchronization is not implemented. (just implemented for cpu hotplug)
576 * If there are kernel internal actions which can make use of some not-exact
577 * value, and reading all cpu value can be performance bottleneck in some
578 * common workload, threshold and synchronization as vmstat[] should be
582 mem_cgroup_read_stat(struct mem_cgroup
*memcg
, enum mem_cgroup_stat_index idx
)
587 /* Per-cpu values can be negative, use a signed accumulator */
588 for_each_possible_cpu(cpu
)
589 val
+= per_cpu(memcg
->stat
->count
[idx
], cpu
);
591 * Summing races with updates, so val may be negative. Avoid exposing
592 * transient negative values.
599 static unsigned long mem_cgroup_read_events(struct mem_cgroup
*memcg
,
600 enum mem_cgroup_events_index idx
)
602 unsigned long val
= 0;
605 for_each_possible_cpu(cpu
)
606 val
+= per_cpu(memcg
->stat
->events
[idx
], cpu
);
610 static void mem_cgroup_charge_statistics(struct mem_cgroup
*memcg
,
612 bool compound
, int nr_pages
)
615 * Here, RSS means 'mapped anon' and anon's SwapCache. Shmem/tmpfs is
616 * counted as CACHE even if it's on ANON LRU.
619 __this_cpu_add(memcg
->stat
->count
[MEM_CGROUP_STAT_RSS
],
622 __this_cpu_add(memcg
->stat
->count
[MEM_CGROUP_STAT_CACHE
],
626 VM_BUG_ON_PAGE(!PageTransHuge(page
), page
);
627 __this_cpu_add(memcg
->stat
->count
[MEM_CGROUP_STAT_RSS_HUGE
],
631 /* pagein of a big page is an event. So, ignore page size */
633 __this_cpu_inc(memcg
->stat
->events
[MEM_CGROUP_EVENTS_PGPGIN
]);
635 __this_cpu_inc(memcg
->stat
->events
[MEM_CGROUP_EVENTS_PGPGOUT
]);
636 nr_pages
= -nr_pages
; /* for event */
639 __this_cpu_add(memcg
->stat
->nr_page_events
, nr_pages
);
642 unsigned long mem_cgroup_node_nr_lru_pages(struct mem_cgroup
*memcg
,
643 int nid
, unsigned int lru_mask
)
645 unsigned long nr
= 0;
648 VM_BUG_ON((unsigned)nid
>= nr_node_ids
);
650 for (zid
= 0; zid
< MAX_NR_ZONES
; zid
++) {
651 struct mem_cgroup_per_zone
*mz
;
655 if (!(BIT(lru
) & lru_mask
))
657 mz
= &memcg
->nodeinfo
[nid
]->zoneinfo
[zid
];
658 nr
+= mz
->lru_size
[lru
];
664 static unsigned long mem_cgroup_nr_lru_pages(struct mem_cgroup
*memcg
,
665 unsigned int lru_mask
)
667 unsigned long nr
= 0;
670 for_each_node_state(nid
, N_MEMORY
)
671 nr
+= mem_cgroup_node_nr_lru_pages(memcg
, nid
, lru_mask
);
675 static bool mem_cgroup_event_ratelimit(struct mem_cgroup
*memcg
,
676 enum mem_cgroup_events_target target
)
678 unsigned long val
, next
;
680 val
= __this_cpu_read(memcg
->stat
->nr_page_events
);
681 next
= __this_cpu_read(memcg
->stat
->targets
[target
]);
682 /* from time_after() in jiffies.h */
683 if ((long)next
- (long)val
< 0) {
685 case MEM_CGROUP_TARGET_THRESH
:
686 next
= val
+ THRESHOLDS_EVENTS_TARGET
;
688 case MEM_CGROUP_TARGET_SOFTLIMIT
:
689 next
= val
+ SOFTLIMIT_EVENTS_TARGET
;
691 case MEM_CGROUP_TARGET_NUMAINFO
:
692 next
= val
+ NUMAINFO_EVENTS_TARGET
;
697 __this_cpu_write(memcg
->stat
->targets
[target
], next
);
704 * Check events in order.
707 static void memcg_check_events(struct mem_cgroup
*memcg
, struct page
*page
)
709 /* threshold event is triggered in finer grain than soft limit */
710 if (unlikely(mem_cgroup_event_ratelimit(memcg
,
711 MEM_CGROUP_TARGET_THRESH
))) {
713 bool do_numainfo __maybe_unused
;
715 do_softlimit
= mem_cgroup_event_ratelimit(memcg
,
716 MEM_CGROUP_TARGET_SOFTLIMIT
);
718 do_numainfo
= mem_cgroup_event_ratelimit(memcg
,
719 MEM_CGROUP_TARGET_NUMAINFO
);
721 mem_cgroup_threshold(memcg
);
722 if (unlikely(do_softlimit
))
723 mem_cgroup_update_tree(memcg
, page
);
725 if (unlikely(do_numainfo
))
726 atomic_inc(&memcg
->numainfo_events
);
731 struct mem_cgroup
*mem_cgroup_from_task(struct task_struct
*p
)
734 * mm_update_next_owner() may clear mm->owner to NULL
735 * if it races with swapoff, page migration, etc.
736 * So this can be called with p == NULL.
741 return mem_cgroup_from_css(task_css(p
, memory_cgrp_id
));
743 EXPORT_SYMBOL(mem_cgroup_from_task
);
745 static struct mem_cgroup
*get_mem_cgroup_from_mm(struct mm_struct
*mm
)
747 struct mem_cgroup
*memcg
= NULL
;
752 * Page cache insertions can happen withou an
753 * actual mm context, e.g. during disk probing
754 * on boot, loopback IO, acct() writes etc.
757 memcg
= root_mem_cgroup
;
759 memcg
= mem_cgroup_from_task(rcu_dereference(mm
->owner
));
760 if (unlikely(!memcg
))
761 memcg
= root_mem_cgroup
;
763 } while (!css_tryget_online(&memcg
->css
));
769 * mem_cgroup_iter - iterate over memory cgroup hierarchy
770 * @root: hierarchy root
771 * @prev: previously returned memcg, NULL on first invocation
772 * @reclaim: cookie for shared reclaim walks, NULL for full walks
774 * Returns references to children of the hierarchy below @root, or
775 * @root itself, or %NULL after a full round-trip.
777 * Caller must pass the return value in @prev on subsequent
778 * invocations for reference counting, or use mem_cgroup_iter_break()
779 * to cancel a hierarchy walk before the round-trip is complete.
781 * Reclaimers can specify a zone and a priority level in @reclaim to
782 * divide up the memcgs in the hierarchy among all concurrent
783 * reclaimers operating on the same zone and priority.
785 struct mem_cgroup
*mem_cgroup_iter(struct mem_cgroup
*root
,
786 struct mem_cgroup
*prev
,
787 struct mem_cgroup_reclaim_cookie
*reclaim
)
789 struct mem_cgroup_reclaim_iter
*uninitialized_var(iter
);
790 struct cgroup_subsys_state
*css
= NULL
;
791 struct mem_cgroup
*memcg
= NULL
;
792 struct mem_cgroup
*pos
= NULL
;
794 if (mem_cgroup_disabled())
798 root
= root_mem_cgroup
;
800 if (prev
&& !reclaim
)
803 if (!root
->use_hierarchy
&& root
!= root_mem_cgroup
) {
812 struct mem_cgroup_per_zone
*mz
;
814 mz
= mem_cgroup_zone_zoneinfo(root
, reclaim
->zone
);
815 iter
= &mz
->iter
[reclaim
->priority
];
817 if (prev
&& reclaim
->generation
!= iter
->generation
)
821 pos
= READ_ONCE(iter
->position
);
822 if (!pos
|| css_tryget(&pos
->css
))
825 * css reference reached zero, so iter->position will
826 * be cleared by ->css_released. However, we should not
827 * rely on this happening soon, because ->css_released
828 * is called from a work queue, and by busy-waiting we
829 * might block it. So we clear iter->position right
832 (void)cmpxchg(&iter
->position
, pos
, NULL
);
840 css
= css_next_descendant_pre(css
, &root
->css
);
843 * Reclaimers share the hierarchy walk, and a
844 * new one might jump in right at the end of
845 * the hierarchy - make sure they see at least
846 * one group and restart from the beginning.
854 * Verify the css and acquire a reference. The root
855 * is provided by the caller, so we know it's alive
856 * and kicking, and don't take an extra reference.
858 memcg
= mem_cgroup_from_css(css
);
860 if (css
== &root
->css
)
871 * The position could have already been updated by a competing
872 * thread, so check that the value hasn't changed since we read
873 * it to avoid reclaiming from the same cgroup twice.
875 (void)cmpxchg(&iter
->position
, pos
, memcg
);
883 reclaim
->generation
= iter
->generation
;
889 if (prev
&& prev
!= root
)
896 * mem_cgroup_iter_break - abort a hierarchy walk prematurely
897 * @root: hierarchy root
898 * @prev: last visited hierarchy member as returned by mem_cgroup_iter()
900 void mem_cgroup_iter_break(struct mem_cgroup
*root
,
901 struct mem_cgroup
*prev
)
904 root
= root_mem_cgroup
;
905 if (prev
&& prev
!= root
)
909 static void invalidate_reclaim_iterators(struct mem_cgroup
*dead_memcg
)
911 struct mem_cgroup
*memcg
= dead_memcg
;
912 struct mem_cgroup_reclaim_iter
*iter
;
913 struct mem_cgroup_per_zone
*mz
;
917 while ((memcg
= parent_mem_cgroup(memcg
))) {
919 for (zid
= 0; zid
< MAX_NR_ZONES
; zid
++) {
920 mz
= &memcg
->nodeinfo
[nid
]->zoneinfo
[zid
];
921 for (i
= 0; i
<= DEF_PRIORITY
; i
++) {
923 cmpxchg(&iter
->position
,
932 * Iteration constructs for visiting all cgroups (under a tree). If
933 * loops are exited prematurely (break), mem_cgroup_iter_break() must
934 * be used for reference counting.
936 #define for_each_mem_cgroup_tree(iter, root) \
937 for (iter = mem_cgroup_iter(root, NULL, NULL); \
939 iter = mem_cgroup_iter(root, iter, NULL))
941 #define for_each_mem_cgroup(iter) \
942 for (iter = mem_cgroup_iter(NULL, NULL, NULL); \
944 iter = mem_cgroup_iter(NULL, iter, NULL))
947 * mem_cgroup_zone_lruvec - get the lru list vector for a zone and memcg
948 * @zone: zone of the wanted lruvec
949 * @memcg: memcg of the wanted lruvec
951 * Returns the lru list vector holding pages for the given @zone and
952 * @mem. This can be the global zone lruvec, if the memory controller
955 struct lruvec
*mem_cgroup_zone_lruvec(struct zone
*zone
,
956 struct mem_cgroup
*memcg
)
958 struct mem_cgroup_per_zone
*mz
;
959 struct lruvec
*lruvec
;
961 if (mem_cgroup_disabled()) {
962 lruvec
= &zone
->lruvec
;
966 mz
= mem_cgroup_zone_zoneinfo(memcg
, zone
);
967 lruvec
= &mz
->lruvec
;
970 * Since a node can be onlined after the mem_cgroup was created,
971 * we have to be prepared to initialize lruvec->zone here;
972 * and if offlined then reonlined, we need to reinitialize it.
974 if (unlikely(lruvec
->zone
!= zone
))
980 * mem_cgroup_page_lruvec - return lruvec for isolating/putting an LRU page
982 * @zone: zone of the page
984 * This function is only safe when following the LRU page isolation
985 * and putback protocol: the LRU lock must be held, and the page must
986 * either be PageLRU() or the caller must have isolated/allocated it.
988 struct lruvec
*mem_cgroup_page_lruvec(struct page
*page
, struct zone
*zone
)
990 struct mem_cgroup_per_zone
*mz
;
991 struct mem_cgroup
*memcg
;
992 struct lruvec
*lruvec
;
994 if (mem_cgroup_disabled()) {
995 lruvec
= &zone
->lruvec
;
999 memcg
= page
->mem_cgroup
;
1001 * Swapcache readahead pages are added to the LRU - and
1002 * possibly migrated - before they are charged.
1005 memcg
= root_mem_cgroup
;
1007 mz
= mem_cgroup_page_zoneinfo(memcg
, page
);
1008 lruvec
= &mz
->lruvec
;
1011 * Since a node can be onlined after the mem_cgroup was created,
1012 * we have to be prepared to initialize lruvec->zone here;
1013 * and if offlined then reonlined, we need to reinitialize it.
1015 if (unlikely(lruvec
->zone
!= zone
))
1016 lruvec
->zone
= zone
;
1021 * mem_cgroup_update_lru_size - account for adding or removing an lru page
1022 * @lruvec: mem_cgroup per zone lru vector
1023 * @lru: index of lru list the page is sitting on
1024 * @nr_pages: positive when adding or negative when removing
1026 * This function must be called under lru_lock, just before a page is added
1027 * to or just after a page is removed from an lru list (that ordering being
1028 * so as to allow it to check that lru_size 0 is consistent with list_empty).
1030 void mem_cgroup_update_lru_size(struct lruvec
*lruvec
, enum lru_list lru
,
1033 struct mem_cgroup_per_zone
*mz
;
1034 unsigned long *lru_size
;
1038 __update_lru_size(lruvec
, lru
, nr_pages
);
1040 if (mem_cgroup_disabled())
1043 mz
= container_of(lruvec
, struct mem_cgroup_per_zone
, lruvec
);
1044 lru_size
= mz
->lru_size
+ lru
;
1045 empty
= list_empty(lruvec
->lists
+ lru
);
1048 *lru_size
+= nr_pages
;
1051 if (WARN_ONCE(size
< 0 || empty
!= !size
,
1052 "%s(%p, %d, %d): lru_size %ld but %sempty\n",
1053 __func__
, lruvec
, lru
, nr_pages
, size
, empty
? "" : "not ")) {
1059 *lru_size
+= nr_pages
;
1062 bool task_in_mem_cgroup(struct task_struct
*task
, struct mem_cgroup
*memcg
)
1064 struct mem_cgroup
*task_memcg
;
1065 struct task_struct
*p
;
1068 p
= find_lock_task_mm(task
);
1070 task_memcg
= get_mem_cgroup_from_mm(p
->mm
);
1074 * All threads may have already detached their mm's, but the oom
1075 * killer still needs to detect if they have already been oom
1076 * killed to prevent needlessly killing additional tasks.
1079 task_memcg
= mem_cgroup_from_task(task
);
1080 css_get(&task_memcg
->css
);
1083 ret
= mem_cgroup_is_descendant(task_memcg
, memcg
);
1084 css_put(&task_memcg
->css
);
1089 * mem_cgroup_margin - calculate chargeable space of a memory cgroup
1090 * @memcg: the memory cgroup
1092 * Returns the maximum amount of memory @mem can be charged with, in
1095 static unsigned long mem_cgroup_margin(struct mem_cgroup
*memcg
)
1097 unsigned long margin
= 0;
1098 unsigned long count
;
1099 unsigned long limit
;
1101 count
= page_counter_read(&memcg
->memory
);
1102 limit
= READ_ONCE(memcg
->memory
.limit
);
1104 margin
= limit
- count
;
1106 if (do_memsw_account()) {
1107 count
= page_counter_read(&memcg
->memsw
);
1108 limit
= READ_ONCE(memcg
->memsw
.limit
);
1110 margin
= min(margin
, limit
- count
);
1119 * A routine for checking "mem" is under move_account() or not.
1121 * Checking a cgroup is mc.from or mc.to or under hierarchy of
1122 * moving cgroups. This is for waiting at high-memory pressure
1125 static bool mem_cgroup_under_move(struct mem_cgroup
*memcg
)
1127 struct mem_cgroup
*from
;
1128 struct mem_cgroup
*to
;
1131 * Unlike task_move routines, we access mc.to, mc.from not under
1132 * mutual exclusion by cgroup_mutex. Here, we take spinlock instead.
1134 spin_lock(&mc
.lock
);
1140 ret
= mem_cgroup_is_descendant(from
, memcg
) ||
1141 mem_cgroup_is_descendant(to
, memcg
);
1143 spin_unlock(&mc
.lock
);
1147 static bool mem_cgroup_wait_acct_move(struct mem_cgroup
*memcg
)
1149 if (mc
.moving_task
&& current
!= mc
.moving_task
) {
1150 if (mem_cgroup_under_move(memcg
)) {
1152 prepare_to_wait(&mc
.waitq
, &wait
, TASK_INTERRUPTIBLE
);
1153 /* moving charge context might have finished. */
1156 finish_wait(&mc
.waitq
, &wait
);
1163 #define K(x) ((x) << (PAGE_SHIFT-10))
1165 * mem_cgroup_print_oom_info: Print OOM information relevant to memory controller.
1166 * @memcg: The memory cgroup that went over limit
1167 * @p: Task that is going to be killed
1169 * NOTE: @memcg and @p's mem_cgroup can be different when hierarchy is
1172 void mem_cgroup_print_oom_info(struct mem_cgroup
*memcg
, struct task_struct
*p
)
1174 struct mem_cgroup
*iter
;
1180 pr_info("Task in ");
1181 pr_cont_cgroup_path(task_cgroup(p
, memory_cgrp_id
));
1182 pr_cont(" killed as a result of limit of ");
1184 pr_info("Memory limit reached of cgroup ");
1187 pr_cont_cgroup_path(memcg
->css
.cgroup
);
1192 pr_info("memory: usage %llukB, limit %llukB, failcnt %lu\n",
1193 K((u64
)page_counter_read(&memcg
->memory
)),
1194 K((u64
)memcg
->memory
.limit
), memcg
->memory
.failcnt
);
1195 pr_info("memory+swap: usage %llukB, limit %llukB, failcnt %lu\n",
1196 K((u64
)page_counter_read(&memcg
->memsw
)),
1197 K((u64
)memcg
->memsw
.limit
), memcg
->memsw
.failcnt
);
1198 pr_info("kmem: usage %llukB, limit %llukB, failcnt %lu\n",
1199 K((u64
)page_counter_read(&memcg
->kmem
)),
1200 K((u64
)memcg
->kmem
.limit
), memcg
->kmem
.failcnt
);
1202 for_each_mem_cgroup_tree(iter
, memcg
) {
1203 pr_info("Memory cgroup stats for ");
1204 pr_cont_cgroup_path(iter
->css
.cgroup
);
1207 for (i
= 0; i
< MEM_CGROUP_STAT_NSTATS
; i
++) {
1208 if (i
== MEM_CGROUP_STAT_SWAP
&& !do_swap_account
)
1210 pr_cont(" %s:%luKB", mem_cgroup_stat_names
[i
],
1211 K(mem_cgroup_read_stat(iter
, i
)));
1214 for (i
= 0; i
< NR_LRU_LISTS
; i
++)
1215 pr_cont(" %s:%luKB", mem_cgroup_lru_names
[i
],
1216 K(mem_cgroup_nr_lru_pages(iter
, BIT(i
))));
1223 * This function returns the number of memcg under hierarchy tree. Returns
1224 * 1(self count) if no children.
1226 static int mem_cgroup_count_children(struct mem_cgroup
*memcg
)
1229 struct mem_cgroup
*iter
;
1231 for_each_mem_cgroup_tree(iter
, memcg
)
1237 * Return the memory (and swap, if configured) limit for a memcg.
1239 static unsigned long mem_cgroup_get_limit(struct mem_cgroup
*memcg
)
1241 unsigned long limit
;
1243 limit
= memcg
->memory
.limit
;
1244 if (mem_cgroup_swappiness(memcg
)) {
1245 unsigned long memsw_limit
;
1246 unsigned long swap_limit
;
1248 memsw_limit
= memcg
->memsw
.limit
;
1249 swap_limit
= memcg
->swap
.limit
;
1250 swap_limit
= min(swap_limit
, (unsigned long)total_swap_pages
);
1251 limit
= min(limit
+ swap_limit
, memsw_limit
);
1256 static bool mem_cgroup_out_of_memory(struct mem_cgroup
*memcg
, gfp_t gfp_mask
,
1259 struct oom_control oc
= {
1263 .gfp_mask
= gfp_mask
,
1266 struct mem_cgroup
*iter
;
1267 unsigned long chosen_points
= 0;
1268 unsigned long totalpages
;
1269 unsigned int points
= 0;
1270 struct task_struct
*chosen
= NULL
;
1272 mutex_lock(&oom_lock
);
1275 * If current has a pending SIGKILL or is exiting, then automatically
1276 * select it. The goal is to allow it to allocate so that it may
1277 * quickly exit and free its memory.
1279 if (fatal_signal_pending(current
) || task_will_free_mem(current
)) {
1280 mark_oom_victim(current
);
1281 try_oom_reaper(current
);
1285 check_panic_on_oom(&oc
, CONSTRAINT_MEMCG
);
1286 totalpages
= mem_cgroup_get_limit(memcg
) ? : 1;
1287 for_each_mem_cgroup_tree(iter
, memcg
) {
1288 struct css_task_iter it
;
1289 struct task_struct
*task
;
1291 css_task_iter_start(&iter
->css
, &it
);
1292 while ((task
= css_task_iter_next(&it
))) {
1293 switch (oom_scan_process_thread(&oc
, task
, totalpages
)) {
1294 case OOM_SCAN_SELECT
:
1296 put_task_struct(chosen
);
1298 chosen_points
= ULONG_MAX
;
1299 get_task_struct(chosen
);
1301 case OOM_SCAN_CONTINUE
:
1303 case OOM_SCAN_ABORT
:
1304 css_task_iter_end(&it
);
1305 mem_cgroup_iter_break(memcg
, iter
);
1307 put_task_struct(chosen
);
1308 /* Set a dummy value to return "true". */
1309 chosen
= (void *) 1;
1314 points
= oom_badness(task
, memcg
, NULL
, totalpages
);
1315 if (!points
|| points
< chosen_points
)
1317 /* Prefer thread group leaders for display purposes */
1318 if (points
== chosen_points
&&
1319 thread_group_leader(chosen
))
1323 put_task_struct(chosen
);
1325 chosen_points
= points
;
1326 get_task_struct(chosen
);
1328 css_task_iter_end(&it
);
1332 points
= chosen_points
* 1000 / totalpages
;
1333 oom_kill_process(&oc
, chosen
, points
, totalpages
,
1334 "Memory cgroup out of memory");
1337 mutex_unlock(&oom_lock
);
1341 #if MAX_NUMNODES > 1
1344 * test_mem_cgroup_node_reclaimable
1345 * @memcg: the target memcg
1346 * @nid: the node ID to be checked.
1347 * @noswap : specify true here if the user wants flle only information.
1349 * This function returns whether the specified memcg contains any
1350 * reclaimable pages on a node. Returns true if there are any reclaimable
1351 * pages in the node.
1353 static bool test_mem_cgroup_node_reclaimable(struct mem_cgroup
*memcg
,
1354 int nid
, bool noswap
)
1356 if (mem_cgroup_node_nr_lru_pages(memcg
, nid
, LRU_ALL_FILE
))
1358 if (noswap
|| !total_swap_pages
)
1360 if (mem_cgroup_node_nr_lru_pages(memcg
, nid
, LRU_ALL_ANON
))
1367 * Always updating the nodemask is not very good - even if we have an empty
1368 * list or the wrong list here, we can start from some node and traverse all
1369 * nodes based on the zonelist. So update the list loosely once per 10 secs.
1372 static void mem_cgroup_may_update_nodemask(struct mem_cgroup
*memcg
)
1376 * numainfo_events > 0 means there was at least NUMAINFO_EVENTS_TARGET
1377 * pagein/pageout changes since the last update.
1379 if (!atomic_read(&memcg
->numainfo_events
))
1381 if (atomic_inc_return(&memcg
->numainfo_updating
) > 1)
1384 /* make a nodemask where this memcg uses memory from */
1385 memcg
->scan_nodes
= node_states
[N_MEMORY
];
1387 for_each_node_mask(nid
, node_states
[N_MEMORY
]) {
1389 if (!test_mem_cgroup_node_reclaimable(memcg
, nid
, false))
1390 node_clear(nid
, memcg
->scan_nodes
);
1393 atomic_set(&memcg
->numainfo_events
, 0);
1394 atomic_set(&memcg
->numainfo_updating
, 0);
1398 * Selecting a node where we start reclaim from. Because what we need is just
1399 * reducing usage counter, start from anywhere is O,K. Considering
1400 * memory reclaim from current node, there are pros. and cons.
1402 * Freeing memory from current node means freeing memory from a node which
1403 * we'll use or we've used. So, it may make LRU bad. And if several threads
1404 * hit limits, it will see a contention on a node. But freeing from remote
1405 * node means more costs for memory reclaim because of memory latency.
1407 * Now, we use round-robin. Better algorithm is welcomed.
1409 int mem_cgroup_select_victim_node(struct mem_cgroup
*memcg
)
1413 mem_cgroup_may_update_nodemask(memcg
);
1414 node
= memcg
->last_scanned_node
;
1416 node
= next_node_in(node
, memcg
->scan_nodes
);
1418 * mem_cgroup_may_update_nodemask might have seen no reclaimmable pages
1419 * last time it really checked all the LRUs due to rate limiting.
1420 * Fallback to the current node in that case for simplicity.
1422 if (unlikely(node
== MAX_NUMNODES
))
1423 node
= numa_node_id();
1425 memcg
->last_scanned_node
= node
;
1429 int mem_cgroup_select_victim_node(struct mem_cgroup
*memcg
)
1435 static int mem_cgroup_soft_reclaim(struct mem_cgroup
*root_memcg
,
1438 unsigned long *total_scanned
)
1440 struct mem_cgroup
*victim
= NULL
;
1443 unsigned long excess
;
1444 unsigned long nr_scanned
;
1445 struct mem_cgroup_reclaim_cookie reclaim
= {
1450 excess
= soft_limit_excess(root_memcg
);
1453 victim
= mem_cgroup_iter(root_memcg
, victim
, &reclaim
);
1458 * If we have not been able to reclaim
1459 * anything, it might because there are
1460 * no reclaimable pages under this hierarchy
1465 * We want to do more targeted reclaim.
1466 * excess >> 2 is not to excessive so as to
1467 * reclaim too much, nor too less that we keep
1468 * coming back to reclaim from this cgroup
1470 if (total
>= (excess
>> 2) ||
1471 (loop
> MEM_CGROUP_MAX_RECLAIM_LOOPS
))
1476 total
+= mem_cgroup_shrink_node_zone(victim
, gfp_mask
, false,
1478 *total_scanned
+= nr_scanned
;
1479 if (!soft_limit_excess(root_memcg
))
1482 mem_cgroup_iter_break(root_memcg
, victim
);
1486 #ifdef CONFIG_LOCKDEP
1487 static struct lockdep_map memcg_oom_lock_dep_map
= {
1488 .name
= "memcg_oom_lock",
1492 static DEFINE_SPINLOCK(memcg_oom_lock
);
1495 * Check OOM-Killer is already running under our hierarchy.
1496 * If someone is running, return false.
1498 static bool mem_cgroup_oom_trylock(struct mem_cgroup
*memcg
)
1500 struct mem_cgroup
*iter
, *failed
= NULL
;
1502 spin_lock(&memcg_oom_lock
);
1504 for_each_mem_cgroup_tree(iter
, memcg
) {
1505 if (iter
->oom_lock
) {
1507 * this subtree of our hierarchy is already locked
1508 * so we cannot give a lock.
1511 mem_cgroup_iter_break(memcg
, iter
);
1514 iter
->oom_lock
= true;
1519 * OK, we failed to lock the whole subtree so we have
1520 * to clean up what we set up to the failing subtree
1522 for_each_mem_cgroup_tree(iter
, memcg
) {
1523 if (iter
== failed
) {
1524 mem_cgroup_iter_break(memcg
, iter
);
1527 iter
->oom_lock
= false;
1530 mutex_acquire(&memcg_oom_lock_dep_map
, 0, 1, _RET_IP_
);
1532 spin_unlock(&memcg_oom_lock
);
1537 static void mem_cgroup_oom_unlock(struct mem_cgroup
*memcg
)
1539 struct mem_cgroup
*iter
;
1541 spin_lock(&memcg_oom_lock
);
1542 mutex_release(&memcg_oom_lock_dep_map
, 1, _RET_IP_
);
1543 for_each_mem_cgroup_tree(iter
, memcg
)
1544 iter
->oom_lock
= false;
1545 spin_unlock(&memcg_oom_lock
);
1548 static void mem_cgroup_mark_under_oom(struct mem_cgroup
*memcg
)
1550 struct mem_cgroup
*iter
;
1552 spin_lock(&memcg_oom_lock
);
1553 for_each_mem_cgroup_tree(iter
, memcg
)
1555 spin_unlock(&memcg_oom_lock
);
1558 static void mem_cgroup_unmark_under_oom(struct mem_cgroup
*memcg
)
1560 struct mem_cgroup
*iter
;
1563 * When a new child is created while the hierarchy is under oom,
1564 * mem_cgroup_oom_lock() may not be called. Watch for underflow.
1566 spin_lock(&memcg_oom_lock
);
1567 for_each_mem_cgroup_tree(iter
, memcg
)
1568 if (iter
->under_oom
> 0)
1570 spin_unlock(&memcg_oom_lock
);
1573 static DECLARE_WAIT_QUEUE_HEAD(memcg_oom_waitq
);
1575 struct oom_wait_info
{
1576 struct mem_cgroup
*memcg
;
1580 static int memcg_oom_wake_function(wait_queue_t
*wait
,
1581 unsigned mode
, int sync
, void *arg
)
1583 struct mem_cgroup
*wake_memcg
= (struct mem_cgroup
*)arg
;
1584 struct mem_cgroup
*oom_wait_memcg
;
1585 struct oom_wait_info
*oom_wait_info
;
1587 oom_wait_info
= container_of(wait
, struct oom_wait_info
, wait
);
1588 oom_wait_memcg
= oom_wait_info
->memcg
;
1590 if (!mem_cgroup_is_descendant(wake_memcg
, oom_wait_memcg
) &&
1591 !mem_cgroup_is_descendant(oom_wait_memcg
, wake_memcg
))
1593 return autoremove_wake_function(wait
, mode
, sync
, arg
);
1596 static void memcg_oom_recover(struct mem_cgroup
*memcg
)
1599 * For the following lockless ->under_oom test, the only required
1600 * guarantee is that it must see the state asserted by an OOM when
1601 * this function is called as a result of userland actions
1602 * triggered by the notification of the OOM. This is trivially
1603 * achieved by invoking mem_cgroup_mark_under_oom() before
1604 * triggering notification.
1606 if (memcg
&& memcg
->under_oom
)
1607 __wake_up(&memcg_oom_waitq
, TASK_NORMAL
, 0, memcg
);
1610 static void mem_cgroup_oom(struct mem_cgroup
*memcg
, gfp_t mask
, int order
)
1612 if (!current
->memcg_may_oom
)
1615 * We are in the middle of the charge context here, so we
1616 * don't want to block when potentially sitting on a callstack
1617 * that holds all kinds of filesystem and mm locks.
1619 * Also, the caller may handle a failed allocation gracefully
1620 * (like optional page cache readahead) and so an OOM killer
1621 * invocation might not even be necessary.
1623 * That's why we don't do anything here except remember the
1624 * OOM context and then deal with it at the end of the page
1625 * fault when the stack is unwound, the locks are released,
1626 * and when we know whether the fault was overall successful.
1628 css_get(&memcg
->css
);
1629 current
->memcg_in_oom
= memcg
;
1630 current
->memcg_oom_gfp_mask
= mask
;
1631 current
->memcg_oom_order
= order
;
1635 * mem_cgroup_oom_synchronize - complete memcg OOM handling
1636 * @handle: actually kill/wait or just clean up the OOM state
1638 * This has to be called at the end of a page fault if the memcg OOM
1639 * handler was enabled.
1641 * Memcg supports userspace OOM handling where failed allocations must
1642 * sleep on a waitqueue until the userspace task resolves the
1643 * situation. Sleeping directly in the charge context with all kinds
1644 * of locks held is not a good idea, instead we remember an OOM state
1645 * in the task and mem_cgroup_oom_synchronize() has to be called at
1646 * the end of the page fault to complete the OOM handling.
1648 * Returns %true if an ongoing memcg OOM situation was detected and
1649 * completed, %false otherwise.
1651 bool mem_cgroup_oom_synchronize(bool handle
)
1653 struct mem_cgroup
*memcg
= current
->memcg_in_oom
;
1654 struct oom_wait_info owait
;
1657 /* OOM is global, do not handle */
1661 if (!handle
|| oom_killer_disabled
)
1664 owait
.memcg
= memcg
;
1665 owait
.wait
.flags
= 0;
1666 owait
.wait
.func
= memcg_oom_wake_function
;
1667 owait
.wait
.private = current
;
1668 INIT_LIST_HEAD(&owait
.wait
.task_list
);
1670 prepare_to_wait(&memcg_oom_waitq
, &owait
.wait
, TASK_KILLABLE
);
1671 mem_cgroup_mark_under_oom(memcg
);
1673 locked
= mem_cgroup_oom_trylock(memcg
);
1676 mem_cgroup_oom_notify(memcg
);
1678 if (locked
&& !memcg
->oom_kill_disable
) {
1679 mem_cgroup_unmark_under_oom(memcg
);
1680 finish_wait(&memcg_oom_waitq
, &owait
.wait
);
1681 mem_cgroup_out_of_memory(memcg
, current
->memcg_oom_gfp_mask
,
1682 current
->memcg_oom_order
);
1685 mem_cgroup_unmark_under_oom(memcg
);
1686 finish_wait(&memcg_oom_waitq
, &owait
.wait
);
1690 mem_cgroup_oom_unlock(memcg
);
1692 * There is no guarantee that an OOM-lock contender
1693 * sees the wakeups triggered by the OOM kill
1694 * uncharges. Wake any sleepers explicitely.
1696 memcg_oom_recover(memcg
);
1699 current
->memcg_in_oom
= NULL
;
1700 css_put(&memcg
->css
);
1705 * lock_page_memcg - lock a page->mem_cgroup binding
1708 * This function protects unlocked LRU pages from being moved to
1709 * another cgroup and stabilizes their page->mem_cgroup binding.
1711 void lock_page_memcg(struct page
*page
)
1713 struct mem_cgroup
*memcg
;
1714 unsigned long flags
;
1717 * The RCU lock is held throughout the transaction. The fast
1718 * path can get away without acquiring the memcg->move_lock
1719 * because page moving starts with an RCU grace period.
1723 if (mem_cgroup_disabled())
1726 memcg
= page
->mem_cgroup
;
1727 if (unlikely(!memcg
))
1730 if (atomic_read(&memcg
->moving_account
) <= 0)
1733 spin_lock_irqsave(&memcg
->move_lock
, flags
);
1734 if (memcg
!= page
->mem_cgroup
) {
1735 spin_unlock_irqrestore(&memcg
->move_lock
, flags
);
1740 * When charge migration first begins, we can have locked and
1741 * unlocked page stat updates happening concurrently. Track
1742 * the task who has the lock for unlock_page_memcg().
1744 memcg
->move_lock_task
= current
;
1745 memcg
->move_lock_flags
= flags
;
1749 EXPORT_SYMBOL(lock_page_memcg
);
1752 * unlock_page_memcg - unlock a page->mem_cgroup binding
1755 void unlock_page_memcg(struct page
*page
)
1757 struct mem_cgroup
*memcg
= page
->mem_cgroup
;
1759 if (memcg
&& memcg
->move_lock_task
== current
) {
1760 unsigned long flags
= memcg
->move_lock_flags
;
1762 memcg
->move_lock_task
= NULL
;
1763 memcg
->move_lock_flags
= 0;
1765 spin_unlock_irqrestore(&memcg
->move_lock
, flags
);
1770 EXPORT_SYMBOL(unlock_page_memcg
);
1773 * size of first charge trial. "32" comes from vmscan.c's magic value.
1774 * TODO: maybe necessary to use big numbers in big irons.
1776 #define CHARGE_BATCH 32U
1777 struct memcg_stock_pcp
{
1778 struct mem_cgroup
*cached
; /* this never be root cgroup */
1779 unsigned int nr_pages
;
1780 struct work_struct work
;
1781 unsigned long flags
;
1782 #define FLUSHING_CACHED_CHARGE 0
1784 static DEFINE_PER_CPU(struct memcg_stock_pcp
, memcg_stock
);
1785 static DEFINE_MUTEX(percpu_charge_mutex
);
1788 * consume_stock: Try to consume stocked charge on this cpu.
1789 * @memcg: memcg to consume from.
1790 * @nr_pages: how many pages to charge.
1792 * The charges will only happen if @memcg matches the current cpu's memcg
1793 * stock, and at least @nr_pages are available in that stock. Failure to
1794 * service an allocation will refill the stock.
1796 * returns true if successful, false otherwise.
1798 static bool consume_stock(struct mem_cgroup
*memcg
, unsigned int nr_pages
)
1800 struct memcg_stock_pcp
*stock
;
1803 if (nr_pages
> CHARGE_BATCH
)
1806 stock
= &get_cpu_var(memcg_stock
);
1807 if (memcg
== stock
->cached
&& stock
->nr_pages
>= nr_pages
) {
1808 stock
->nr_pages
-= nr_pages
;
1811 put_cpu_var(memcg_stock
);
1816 * Returns stocks cached in percpu and reset cached information.
1818 static void drain_stock(struct memcg_stock_pcp
*stock
)
1820 struct mem_cgroup
*old
= stock
->cached
;
1822 if (stock
->nr_pages
) {
1823 page_counter_uncharge(&old
->memory
, stock
->nr_pages
);
1824 if (do_memsw_account())
1825 page_counter_uncharge(&old
->memsw
, stock
->nr_pages
);
1826 css_put_many(&old
->css
, stock
->nr_pages
);
1827 stock
->nr_pages
= 0;
1829 stock
->cached
= NULL
;
1833 * This must be called under preempt disabled or must be called by
1834 * a thread which is pinned to local cpu.
1836 static void drain_local_stock(struct work_struct
*dummy
)
1838 struct memcg_stock_pcp
*stock
= this_cpu_ptr(&memcg_stock
);
1840 clear_bit(FLUSHING_CACHED_CHARGE
, &stock
->flags
);
1844 * Cache charges(val) to local per_cpu area.
1845 * This will be consumed by consume_stock() function, later.
1847 static void refill_stock(struct mem_cgroup
*memcg
, unsigned int nr_pages
)
1849 struct memcg_stock_pcp
*stock
= &get_cpu_var(memcg_stock
);
1851 if (stock
->cached
!= memcg
) { /* reset if necessary */
1853 stock
->cached
= memcg
;
1855 stock
->nr_pages
+= nr_pages
;
1856 put_cpu_var(memcg_stock
);
1860 * Drains all per-CPU charge caches for given root_memcg resp. subtree
1861 * of the hierarchy under it.
1863 static void drain_all_stock(struct mem_cgroup
*root_memcg
)
1867 /* If someone's already draining, avoid adding running more workers. */
1868 if (!mutex_trylock(&percpu_charge_mutex
))
1870 /* Notify other cpus that system-wide "drain" is running */
1873 for_each_online_cpu(cpu
) {
1874 struct memcg_stock_pcp
*stock
= &per_cpu(memcg_stock
, cpu
);
1875 struct mem_cgroup
*memcg
;
1877 memcg
= stock
->cached
;
1878 if (!memcg
|| !stock
->nr_pages
)
1880 if (!mem_cgroup_is_descendant(memcg
, root_memcg
))
1882 if (!test_and_set_bit(FLUSHING_CACHED_CHARGE
, &stock
->flags
)) {
1884 drain_local_stock(&stock
->work
);
1886 schedule_work_on(cpu
, &stock
->work
);
1891 mutex_unlock(&percpu_charge_mutex
);
1894 static int memcg_cpu_hotplug_callback(struct notifier_block
*nb
,
1895 unsigned long action
,
1898 int cpu
= (unsigned long)hcpu
;
1899 struct memcg_stock_pcp
*stock
;
1901 if (action
== CPU_ONLINE
)
1904 if (action
!= CPU_DEAD
&& action
!= CPU_DEAD_FROZEN
)
1907 stock
= &per_cpu(memcg_stock
, cpu
);
1912 static void reclaim_high(struct mem_cgroup
*memcg
,
1913 unsigned int nr_pages
,
1917 if (page_counter_read(&memcg
->memory
) <= memcg
->high
)
1919 mem_cgroup_events(memcg
, MEMCG_HIGH
, 1);
1920 try_to_free_mem_cgroup_pages(memcg
, nr_pages
, gfp_mask
, true);
1921 } while ((memcg
= parent_mem_cgroup(memcg
)));
1924 static void high_work_func(struct work_struct
*work
)
1926 struct mem_cgroup
*memcg
;
1928 memcg
= container_of(work
, struct mem_cgroup
, high_work
);
1929 reclaim_high(memcg
, CHARGE_BATCH
, GFP_KERNEL
);
1933 * Scheduled by try_charge() to be executed from the userland return path
1934 * and reclaims memory over the high limit.
1936 void mem_cgroup_handle_over_high(void)
1938 unsigned int nr_pages
= current
->memcg_nr_pages_over_high
;
1939 struct mem_cgroup
*memcg
;
1941 if (likely(!nr_pages
))
1944 memcg
= get_mem_cgroup_from_mm(current
->mm
);
1945 reclaim_high(memcg
, nr_pages
, GFP_KERNEL
);
1946 css_put(&memcg
->css
);
1947 current
->memcg_nr_pages_over_high
= 0;
1950 static int try_charge(struct mem_cgroup
*memcg
, gfp_t gfp_mask
,
1951 unsigned int nr_pages
)
1953 unsigned int batch
= max(CHARGE_BATCH
, nr_pages
);
1954 int nr_retries
= MEM_CGROUP_RECLAIM_RETRIES
;
1955 struct mem_cgroup
*mem_over_limit
;
1956 struct page_counter
*counter
;
1957 unsigned long nr_reclaimed
;
1958 bool may_swap
= true;
1959 bool drained
= false;
1961 if (mem_cgroup_is_root(memcg
))
1964 if (consume_stock(memcg
, nr_pages
))
1967 if (!do_memsw_account() ||
1968 page_counter_try_charge(&memcg
->memsw
, batch
, &counter
)) {
1969 if (page_counter_try_charge(&memcg
->memory
, batch
, &counter
))
1971 if (do_memsw_account())
1972 page_counter_uncharge(&memcg
->memsw
, batch
);
1973 mem_over_limit
= mem_cgroup_from_counter(counter
, memory
);
1975 mem_over_limit
= mem_cgroup_from_counter(counter
, memsw
);
1979 if (batch
> nr_pages
) {
1985 * Unlike in global OOM situations, memcg is not in a physical
1986 * memory shortage. Allow dying and OOM-killed tasks to
1987 * bypass the last charges so that they can exit quickly and
1988 * free their memory.
1990 if (unlikely(test_thread_flag(TIF_MEMDIE
) ||
1991 fatal_signal_pending(current
) ||
1992 current
->flags
& PF_EXITING
))
1995 if (unlikely(task_in_memcg_oom(current
)))
1998 if (!gfpflags_allow_blocking(gfp_mask
))
2001 mem_cgroup_events(mem_over_limit
, MEMCG_MAX
, 1);
2003 nr_reclaimed
= try_to_free_mem_cgroup_pages(mem_over_limit
, nr_pages
,
2004 gfp_mask
, may_swap
);
2006 if (mem_cgroup_margin(mem_over_limit
) >= nr_pages
)
2010 drain_all_stock(mem_over_limit
);
2015 if (gfp_mask
& __GFP_NORETRY
)
2018 * Even though the limit is exceeded at this point, reclaim
2019 * may have been able to free some pages. Retry the charge
2020 * before killing the task.
2022 * Only for regular pages, though: huge pages are rather
2023 * unlikely to succeed so close to the limit, and we fall back
2024 * to regular pages anyway in case of failure.
2026 if (nr_reclaimed
&& nr_pages
<= (1 << PAGE_ALLOC_COSTLY_ORDER
))
2029 * At task move, charge accounts can be doubly counted. So, it's
2030 * better to wait until the end of task_move if something is going on.
2032 if (mem_cgroup_wait_acct_move(mem_over_limit
))
2038 if (gfp_mask
& __GFP_NOFAIL
)
2041 if (fatal_signal_pending(current
))
2044 mem_cgroup_events(mem_over_limit
, MEMCG_OOM
, 1);
2046 mem_cgroup_oom(mem_over_limit
, gfp_mask
,
2047 get_order(nr_pages
* PAGE_SIZE
));
2049 if (!(gfp_mask
& __GFP_NOFAIL
))
2053 * The allocation either can't fail or will lead to more memory
2054 * being freed very soon. Allow memory usage go over the limit
2055 * temporarily by force charging it.
2057 page_counter_charge(&memcg
->memory
, nr_pages
);
2058 if (do_memsw_account())
2059 page_counter_charge(&memcg
->memsw
, nr_pages
);
2060 css_get_many(&memcg
->css
, nr_pages
);
2065 css_get_many(&memcg
->css
, batch
);
2066 if (batch
> nr_pages
)
2067 refill_stock(memcg
, batch
- nr_pages
);
2070 * If the hierarchy is above the normal consumption range, schedule
2071 * reclaim on returning to userland. We can perform reclaim here
2072 * if __GFP_RECLAIM but let's always punt for simplicity and so that
2073 * GFP_KERNEL can consistently be used during reclaim. @memcg is
2074 * not recorded as it most likely matches current's and won't
2075 * change in the meantime. As high limit is checked again before
2076 * reclaim, the cost of mismatch is negligible.
2079 if (page_counter_read(&memcg
->memory
) > memcg
->high
) {
2080 /* Don't bother a random interrupted task */
2081 if (in_interrupt()) {
2082 schedule_work(&memcg
->high_work
);
2085 current
->memcg_nr_pages_over_high
+= batch
;
2086 set_notify_resume(current
);
2089 } while ((memcg
= parent_mem_cgroup(memcg
)));
2094 static void cancel_charge(struct mem_cgroup
*memcg
, unsigned int nr_pages
)
2096 if (mem_cgroup_is_root(memcg
))
2099 page_counter_uncharge(&memcg
->memory
, nr_pages
);
2100 if (do_memsw_account())
2101 page_counter_uncharge(&memcg
->memsw
, nr_pages
);
2103 css_put_many(&memcg
->css
, nr_pages
);
2106 static void lock_page_lru(struct page
*page
, int *isolated
)
2108 struct zone
*zone
= page_zone(page
);
2110 spin_lock_irq(&zone
->lru_lock
);
2111 if (PageLRU(page
)) {
2112 struct lruvec
*lruvec
;
2114 lruvec
= mem_cgroup_page_lruvec(page
, zone
);
2116 del_page_from_lru_list(page
, lruvec
, page_lru(page
));
2122 static void unlock_page_lru(struct page
*page
, int isolated
)
2124 struct zone
*zone
= page_zone(page
);
2127 struct lruvec
*lruvec
;
2129 lruvec
= mem_cgroup_page_lruvec(page
, zone
);
2130 VM_BUG_ON_PAGE(PageLRU(page
), page
);
2132 add_page_to_lru_list(page
, lruvec
, page_lru(page
));
2134 spin_unlock_irq(&zone
->lru_lock
);
2137 static void commit_charge(struct page
*page
, struct mem_cgroup
*memcg
,
2142 VM_BUG_ON_PAGE(page
->mem_cgroup
, page
);
2145 * In some cases, SwapCache and FUSE(splice_buf->radixtree), the page
2146 * may already be on some other mem_cgroup's LRU. Take care of it.
2149 lock_page_lru(page
, &isolated
);
2152 * Nobody should be changing or seriously looking at
2153 * page->mem_cgroup at this point:
2155 * - the page is uncharged
2157 * - the page is off-LRU
2159 * - an anonymous fault has exclusive page access, except for
2160 * a locked page table
2162 * - a page cache insertion, a swapin fault, or a migration
2163 * have the page locked
2165 page
->mem_cgroup
= memcg
;
2168 unlock_page_lru(page
, isolated
);
2172 static int memcg_alloc_cache_id(void)
2177 id
= ida_simple_get(&memcg_cache_ida
,
2178 0, MEMCG_CACHES_MAX_SIZE
, GFP_KERNEL
);
2182 if (id
< memcg_nr_cache_ids
)
2186 * There's no space for the new id in memcg_caches arrays,
2187 * so we have to grow them.
2189 down_write(&memcg_cache_ids_sem
);
2191 size
= 2 * (id
+ 1);
2192 if (size
< MEMCG_CACHES_MIN_SIZE
)
2193 size
= MEMCG_CACHES_MIN_SIZE
;
2194 else if (size
> MEMCG_CACHES_MAX_SIZE
)
2195 size
= MEMCG_CACHES_MAX_SIZE
;
2197 err
= memcg_update_all_caches(size
);
2199 err
= memcg_update_all_list_lrus(size
);
2201 memcg_nr_cache_ids
= size
;
2203 up_write(&memcg_cache_ids_sem
);
2206 ida_simple_remove(&memcg_cache_ida
, id
);
2212 static void memcg_free_cache_id(int id
)
2214 ida_simple_remove(&memcg_cache_ida
, id
);
2217 struct memcg_kmem_cache_create_work
{
2218 struct mem_cgroup
*memcg
;
2219 struct kmem_cache
*cachep
;
2220 struct work_struct work
;
2223 static void memcg_kmem_cache_create_func(struct work_struct
*w
)
2225 struct memcg_kmem_cache_create_work
*cw
=
2226 container_of(w
, struct memcg_kmem_cache_create_work
, work
);
2227 struct mem_cgroup
*memcg
= cw
->memcg
;
2228 struct kmem_cache
*cachep
= cw
->cachep
;
2230 memcg_create_kmem_cache(memcg
, cachep
);
2232 css_put(&memcg
->css
);
2237 * Enqueue the creation of a per-memcg kmem_cache.
2239 static void __memcg_schedule_kmem_cache_create(struct mem_cgroup
*memcg
,
2240 struct kmem_cache
*cachep
)
2242 struct memcg_kmem_cache_create_work
*cw
;
2244 cw
= kmalloc(sizeof(*cw
), GFP_NOWAIT
);
2248 css_get(&memcg
->css
);
2251 cw
->cachep
= cachep
;
2252 INIT_WORK(&cw
->work
, memcg_kmem_cache_create_func
);
2254 schedule_work(&cw
->work
);
2257 static void memcg_schedule_kmem_cache_create(struct mem_cgroup
*memcg
,
2258 struct kmem_cache
*cachep
)
2261 * We need to stop accounting when we kmalloc, because if the
2262 * corresponding kmalloc cache is not yet created, the first allocation
2263 * in __memcg_schedule_kmem_cache_create will recurse.
2265 * However, it is better to enclose the whole function. Depending on
2266 * the debugging options enabled, INIT_WORK(), for instance, can
2267 * trigger an allocation. This too, will make us recurse. Because at
2268 * this point we can't allow ourselves back into memcg_kmem_get_cache,
2269 * the safest choice is to do it like this, wrapping the whole function.
2271 current
->memcg_kmem_skip_account
= 1;
2272 __memcg_schedule_kmem_cache_create(memcg
, cachep
);
2273 current
->memcg_kmem_skip_account
= 0;
2277 * Return the kmem_cache we're supposed to use for a slab allocation.
2278 * We try to use the current memcg's version of the cache.
2280 * If the cache does not exist yet, if we are the first user of it,
2281 * we either create it immediately, if possible, or create it asynchronously
2283 * In the latter case, we will let the current allocation go through with
2284 * the original cache.
2286 * Can't be called in interrupt context or from kernel threads.
2287 * This function needs to be called with rcu_read_lock() held.
2289 struct kmem_cache
*__memcg_kmem_get_cache(struct kmem_cache
*cachep
, gfp_t gfp
)
2291 struct mem_cgroup
*memcg
;
2292 struct kmem_cache
*memcg_cachep
;
2295 VM_BUG_ON(!is_root_cache(cachep
));
2297 if (cachep
->flags
& SLAB_ACCOUNT
)
2298 gfp
|= __GFP_ACCOUNT
;
2300 if (!(gfp
& __GFP_ACCOUNT
))
2303 if (current
->memcg_kmem_skip_account
)
2306 memcg
= get_mem_cgroup_from_mm(current
->mm
);
2307 kmemcg_id
= READ_ONCE(memcg
->kmemcg_id
);
2311 memcg_cachep
= cache_from_memcg_idx(cachep
, kmemcg_id
);
2312 if (likely(memcg_cachep
))
2313 return memcg_cachep
;
2316 * If we are in a safe context (can wait, and not in interrupt
2317 * context), we could be be predictable and return right away.
2318 * This would guarantee that the allocation being performed
2319 * already belongs in the new cache.
2321 * However, there are some clashes that can arrive from locking.
2322 * For instance, because we acquire the slab_mutex while doing
2323 * memcg_create_kmem_cache, this means no further allocation
2324 * could happen with the slab_mutex held. So it's better to
2327 memcg_schedule_kmem_cache_create(memcg
, cachep
);
2329 css_put(&memcg
->css
);
2333 void __memcg_kmem_put_cache(struct kmem_cache
*cachep
)
2335 if (!is_root_cache(cachep
))
2336 css_put(&cachep
->memcg_params
.memcg
->css
);
2339 int __memcg_kmem_charge_memcg(struct page
*page
, gfp_t gfp
, int order
,
2340 struct mem_cgroup
*memcg
)
2342 unsigned int nr_pages
= 1 << order
;
2343 struct page_counter
*counter
;
2346 ret
= try_charge(memcg
, gfp
, nr_pages
);
2350 if (!cgroup_subsys_on_dfl(memory_cgrp_subsys
) &&
2351 !page_counter_try_charge(&memcg
->kmem
, nr_pages
, &counter
)) {
2352 cancel_charge(memcg
, nr_pages
);
2356 page
->mem_cgroup
= memcg
;
2361 int __memcg_kmem_charge(struct page
*page
, gfp_t gfp
, int order
)
2363 struct mem_cgroup
*memcg
;
2366 memcg
= get_mem_cgroup_from_mm(current
->mm
);
2367 if (!mem_cgroup_is_root(memcg
))
2368 ret
= __memcg_kmem_charge_memcg(page
, gfp
, order
, memcg
);
2369 css_put(&memcg
->css
);
2373 void __memcg_kmem_uncharge(struct page
*page
, int order
)
2375 struct mem_cgroup
*memcg
= page
->mem_cgroup
;
2376 unsigned int nr_pages
= 1 << order
;
2381 VM_BUG_ON_PAGE(mem_cgroup_is_root(memcg
), page
);
2383 if (!cgroup_subsys_on_dfl(memory_cgrp_subsys
))
2384 page_counter_uncharge(&memcg
->kmem
, nr_pages
);
2386 page_counter_uncharge(&memcg
->memory
, nr_pages
);
2387 if (do_memsw_account())
2388 page_counter_uncharge(&memcg
->memsw
, nr_pages
);
2390 page
->mem_cgroup
= NULL
;
2391 css_put_many(&memcg
->css
, nr_pages
);
2393 #endif /* !CONFIG_SLOB */
2395 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
2398 * Because tail pages are not marked as "used", set it. We're under
2399 * zone->lru_lock and migration entries setup in all page mappings.
2401 void mem_cgroup_split_huge_fixup(struct page
*head
)
2405 if (mem_cgroup_disabled())
2408 for (i
= 1; i
< HPAGE_PMD_NR
; i
++)
2409 head
[i
].mem_cgroup
= head
->mem_cgroup
;
2411 __this_cpu_sub(head
->mem_cgroup
->stat
->count
[MEM_CGROUP_STAT_RSS_HUGE
],
2414 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
2416 #ifdef CONFIG_MEMCG_SWAP
2417 static void mem_cgroup_swap_statistics(struct mem_cgroup
*memcg
,
2420 int val
= (charge
) ? 1 : -1;
2421 this_cpu_add(memcg
->stat
->count
[MEM_CGROUP_STAT_SWAP
], val
);
2425 * mem_cgroup_move_swap_account - move swap charge and swap_cgroup's record.
2426 * @entry: swap entry to be moved
2427 * @from: mem_cgroup which the entry is moved from
2428 * @to: mem_cgroup which the entry is moved to
2430 * It succeeds only when the swap_cgroup's record for this entry is the same
2431 * as the mem_cgroup's id of @from.
2433 * Returns 0 on success, -EINVAL on failure.
2435 * The caller must have charged to @to, IOW, called page_counter_charge() about
2436 * both res and memsw, and called css_get().
2438 static int mem_cgroup_move_swap_account(swp_entry_t entry
,
2439 struct mem_cgroup
*from
, struct mem_cgroup
*to
)
2441 unsigned short old_id
, new_id
;
2443 old_id
= mem_cgroup_id(from
);
2444 new_id
= mem_cgroup_id(to
);
2446 if (swap_cgroup_cmpxchg(entry
, old_id
, new_id
) == old_id
) {
2447 mem_cgroup_swap_statistics(from
, false);
2448 mem_cgroup_swap_statistics(to
, true);
2454 static inline int mem_cgroup_move_swap_account(swp_entry_t entry
,
2455 struct mem_cgroup
*from
, struct mem_cgroup
*to
)
2461 static DEFINE_MUTEX(memcg_limit_mutex
);
2463 static int mem_cgroup_resize_limit(struct mem_cgroup
*memcg
,
2464 unsigned long limit
)
2466 unsigned long curusage
;
2467 unsigned long oldusage
;
2468 bool enlarge
= false;
2473 * For keeping hierarchical_reclaim simple, how long we should retry
2474 * is depends on callers. We set our retry-count to be function
2475 * of # of children which we should visit in this loop.
2477 retry_count
= MEM_CGROUP_RECLAIM_RETRIES
*
2478 mem_cgroup_count_children(memcg
);
2480 oldusage
= page_counter_read(&memcg
->memory
);
2483 if (signal_pending(current
)) {
2488 mutex_lock(&memcg_limit_mutex
);
2489 if (limit
> memcg
->memsw
.limit
) {
2490 mutex_unlock(&memcg_limit_mutex
);
2494 if (limit
> memcg
->memory
.limit
)
2496 ret
= page_counter_limit(&memcg
->memory
, limit
);
2497 mutex_unlock(&memcg_limit_mutex
);
2502 try_to_free_mem_cgroup_pages(memcg
, 1, GFP_KERNEL
, true);
2504 curusage
= page_counter_read(&memcg
->memory
);
2505 /* Usage is reduced ? */
2506 if (curusage
>= oldusage
)
2509 oldusage
= curusage
;
2510 } while (retry_count
);
2512 if (!ret
&& enlarge
)
2513 memcg_oom_recover(memcg
);
2518 static int mem_cgroup_resize_memsw_limit(struct mem_cgroup
*memcg
,
2519 unsigned long limit
)
2521 unsigned long curusage
;
2522 unsigned long oldusage
;
2523 bool enlarge
= false;
2527 /* see mem_cgroup_resize_res_limit */
2528 retry_count
= MEM_CGROUP_RECLAIM_RETRIES
*
2529 mem_cgroup_count_children(memcg
);
2531 oldusage
= page_counter_read(&memcg
->memsw
);
2534 if (signal_pending(current
)) {
2539 mutex_lock(&memcg_limit_mutex
);
2540 if (limit
< memcg
->memory
.limit
) {
2541 mutex_unlock(&memcg_limit_mutex
);
2545 if (limit
> memcg
->memsw
.limit
)
2547 ret
= page_counter_limit(&memcg
->memsw
, limit
);
2548 mutex_unlock(&memcg_limit_mutex
);
2553 try_to_free_mem_cgroup_pages(memcg
, 1, GFP_KERNEL
, false);
2555 curusage
= page_counter_read(&memcg
->memsw
);
2556 /* Usage is reduced ? */
2557 if (curusage
>= oldusage
)
2560 oldusage
= curusage
;
2561 } while (retry_count
);
2563 if (!ret
&& enlarge
)
2564 memcg_oom_recover(memcg
);
2569 unsigned long mem_cgroup_soft_limit_reclaim(struct zone
*zone
, int order
,
2571 unsigned long *total_scanned
)
2573 unsigned long nr_reclaimed
= 0;
2574 struct mem_cgroup_per_zone
*mz
, *next_mz
= NULL
;
2575 unsigned long reclaimed
;
2577 struct mem_cgroup_tree_per_zone
*mctz
;
2578 unsigned long excess
;
2579 unsigned long nr_scanned
;
2584 mctz
= soft_limit_tree_node_zone(zone_to_nid(zone
), zone_idx(zone
));
2586 * This loop can run a while, specially if mem_cgroup's continuously
2587 * keep exceeding their soft limit and putting the system under
2594 mz
= mem_cgroup_largest_soft_limit_node(mctz
);
2599 reclaimed
= mem_cgroup_soft_reclaim(mz
->memcg
, zone
,
2600 gfp_mask
, &nr_scanned
);
2601 nr_reclaimed
+= reclaimed
;
2602 *total_scanned
+= nr_scanned
;
2603 spin_lock_irq(&mctz
->lock
);
2604 __mem_cgroup_remove_exceeded(mz
, mctz
);
2607 * If we failed to reclaim anything from this memory cgroup
2608 * it is time to move on to the next cgroup
2612 next_mz
= __mem_cgroup_largest_soft_limit_node(mctz
);
2614 excess
= soft_limit_excess(mz
->memcg
);
2616 * One school of thought says that we should not add
2617 * back the node to the tree if reclaim returns 0.
2618 * But our reclaim could return 0, simply because due
2619 * to priority we are exposing a smaller subset of
2620 * memory to reclaim from. Consider this as a longer
2623 /* If excess == 0, no tree ops */
2624 __mem_cgroup_insert_exceeded(mz
, mctz
, excess
);
2625 spin_unlock_irq(&mctz
->lock
);
2626 css_put(&mz
->memcg
->css
);
2629 * Could not reclaim anything and there are no more
2630 * mem cgroups to try or we seem to be looping without
2631 * reclaiming anything.
2633 if (!nr_reclaimed
&&
2635 loop
> MEM_CGROUP_MAX_SOFT_LIMIT_RECLAIM_LOOPS
))
2637 } while (!nr_reclaimed
);
2639 css_put(&next_mz
->memcg
->css
);
2640 return nr_reclaimed
;
2644 * Test whether @memcg has children, dead or alive. Note that this
2645 * function doesn't care whether @memcg has use_hierarchy enabled and
2646 * returns %true if there are child csses according to the cgroup
2647 * hierarchy. Testing use_hierarchy is the caller's responsiblity.
2649 static inline bool memcg_has_children(struct mem_cgroup
*memcg
)
2654 ret
= css_next_child(NULL
, &memcg
->css
);
2660 * Reclaims as many pages from the given memcg as possible.
2662 * Caller is responsible for holding css reference for memcg.
2664 static int mem_cgroup_force_empty(struct mem_cgroup
*memcg
)
2666 int nr_retries
= MEM_CGROUP_RECLAIM_RETRIES
;
2668 /* we call try-to-free pages for make this cgroup empty */
2669 lru_add_drain_all();
2670 /* try to free all pages in this cgroup */
2671 while (nr_retries
&& page_counter_read(&memcg
->memory
)) {
2674 if (signal_pending(current
))
2677 progress
= try_to_free_mem_cgroup_pages(memcg
, 1,
2681 /* maybe some writeback is necessary */
2682 congestion_wait(BLK_RW_ASYNC
, HZ
/10);
2690 static ssize_t
mem_cgroup_force_empty_write(struct kernfs_open_file
*of
,
2691 char *buf
, size_t nbytes
,
2694 struct mem_cgroup
*memcg
= mem_cgroup_from_css(of_css(of
));
2696 if (mem_cgroup_is_root(memcg
))
2698 return mem_cgroup_force_empty(memcg
) ?: nbytes
;
2701 static u64
mem_cgroup_hierarchy_read(struct cgroup_subsys_state
*css
,
2704 return mem_cgroup_from_css(css
)->use_hierarchy
;
2707 static int mem_cgroup_hierarchy_write(struct cgroup_subsys_state
*css
,
2708 struct cftype
*cft
, u64 val
)
2711 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
2712 struct mem_cgroup
*parent_memcg
= mem_cgroup_from_css(memcg
->css
.parent
);
2714 if (memcg
->use_hierarchy
== val
)
2718 * If parent's use_hierarchy is set, we can't make any modifications
2719 * in the child subtrees. If it is unset, then the change can
2720 * occur, provided the current cgroup has no children.
2722 * For the root cgroup, parent_mem is NULL, we allow value to be
2723 * set if there are no children.
2725 if ((!parent_memcg
|| !parent_memcg
->use_hierarchy
) &&
2726 (val
== 1 || val
== 0)) {
2727 if (!memcg_has_children(memcg
))
2728 memcg
->use_hierarchy
= val
;
2737 static void tree_stat(struct mem_cgroup
*memcg
, unsigned long *stat
)
2739 struct mem_cgroup
*iter
;
2742 memset(stat
, 0, sizeof(*stat
) * MEMCG_NR_STAT
);
2744 for_each_mem_cgroup_tree(iter
, memcg
) {
2745 for (i
= 0; i
< MEMCG_NR_STAT
; i
++)
2746 stat
[i
] += mem_cgroup_read_stat(iter
, i
);
2750 static void tree_events(struct mem_cgroup
*memcg
, unsigned long *events
)
2752 struct mem_cgroup
*iter
;
2755 memset(events
, 0, sizeof(*events
) * MEMCG_NR_EVENTS
);
2757 for_each_mem_cgroup_tree(iter
, memcg
) {
2758 for (i
= 0; i
< MEMCG_NR_EVENTS
; i
++)
2759 events
[i
] += mem_cgroup_read_events(iter
, i
);
2763 static unsigned long mem_cgroup_usage(struct mem_cgroup
*memcg
, bool swap
)
2765 unsigned long val
= 0;
2767 if (mem_cgroup_is_root(memcg
)) {
2768 struct mem_cgroup
*iter
;
2770 for_each_mem_cgroup_tree(iter
, memcg
) {
2771 val
+= mem_cgroup_read_stat(iter
,
2772 MEM_CGROUP_STAT_CACHE
);
2773 val
+= mem_cgroup_read_stat(iter
,
2774 MEM_CGROUP_STAT_RSS
);
2776 val
+= mem_cgroup_read_stat(iter
,
2777 MEM_CGROUP_STAT_SWAP
);
2781 val
= page_counter_read(&memcg
->memory
);
2783 val
= page_counter_read(&memcg
->memsw
);
2796 static u64
mem_cgroup_read_u64(struct cgroup_subsys_state
*css
,
2799 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
2800 struct page_counter
*counter
;
2802 switch (MEMFILE_TYPE(cft
->private)) {
2804 counter
= &memcg
->memory
;
2807 counter
= &memcg
->memsw
;
2810 counter
= &memcg
->kmem
;
2813 counter
= &memcg
->tcpmem
;
2819 switch (MEMFILE_ATTR(cft
->private)) {
2821 if (counter
== &memcg
->memory
)
2822 return (u64
)mem_cgroup_usage(memcg
, false) * PAGE_SIZE
;
2823 if (counter
== &memcg
->memsw
)
2824 return (u64
)mem_cgroup_usage(memcg
, true) * PAGE_SIZE
;
2825 return (u64
)page_counter_read(counter
) * PAGE_SIZE
;
2827 return (u64
)counter
->limit
* PAGE_SIZE
;
2829 return (u64
)counter
->watermark
* PAGE_SIZE
;
2831 return counter
->failcnt
;
2832 case RES_SOFT_LIMIT
:
2833 return (u64
)memcg
->soft_limit
* PAGE_SIZE
;
2840 static int memcg_online_kmem(struct mem_cgroup
*memcg
)
2844 if (cgroup_memory_nokmem
)
2847 BUG_ON(memcg
->kmemcg_id
>= 0);
2848 BUG_ON(memcg
->kmem_state
);
2850 memcg_id
= memcg_alloc_cache_id();
2854 static_branch_inc(&memcg_kmem_enabled_key
);
2856 * A memory cgroup is considered kmem-online as soon as it gets
2857 * kmemcg_id. Setting the id after enabling static branching will
2858 * guarantee no one starts accounting before all call sites are
2861 memcg
->kmemcg_id
= memcg_id
;
2862 memcg
->kmem_state
= KMEM_ONLINE
;
2867 static void memcg_offline_kmem(struct mem_cgroup
*memcg
)
2869 struct cgroup_subsys_state
*css
;
2870 struct mem_cgroup
*parent
, *child
;
2873 if (memcg
->kmem_state
!= KMEM_ONLINE
)
2876 * Clear the online state before clearing memcg_caches array
2877 * entries. The slab_mutex in memcg_deactivate_kmem_caches()
2878 * guarantees that no cache will be created for this cgroup
2879 * after we are done (see memcg_create_kmem_cache()).
2881 memcg
->kmem_state
= KMEM_ALLOCATED
;
2883 memcg_deactivate_kmem_caches(memcg
);
2885 kmemcg_id
= memcg
->kmemcg_id
;
2886 BUG_ON(kmemcg_id
< 0);
2888 parent
= parent_mem_cgroup(memcg
);
2890 parent
= root_mem_cgroup
;
2893 * Change kmemcg_id of this cgroup and all its descendants to the
2894 * parent's id, and then move all entries from this cgroup's list_lrus
2895 * to ones of the parent. After we have finished, all list_lrus
2896 * corresponding to this cgroup are guaranteed to remain empty. The
2897 * ordering is imposed by list_lru_node->lock taken by
2898 * memcg_drain_all_list_lrus().
2900 rcu_read_lock(); /* can be called from css_free w/o cgroup_mutex */
2901 css_for_each_descendant_pre(css
, &memcg
->css
) {
2902 child
= mem_cgroup_from_css(css
);
2903 BUG_ON(child
->kmemcg_id
!= kmemcg_id
);
2904 child
->kmemcg_id
= parent
->kmemcg_id
;
2905 if (!memcg
->use_hierarchy
)
2910 memcg_drain_all_list_lrus(kmemcg_id
, parent
->kmemcg_id
);
2912 memcg_free_cache_id(kmemcg_id
);
2915 static void memcg_free_kmem(struct mem_cgroup
*memcg
)
2917 /* css_alloc() failed, offlining didn't happen */
2918 if (unlikely(memcg
->kmem_state
== KMEM_ONLINE
))
2919 memcg_offline_kmem(memcg
);
2921 if (memcg
->kmem_state
== KMEM_ALLOCATED
) {
2922 memcg_destroy_kmem_caches(memcg
);
2923 static_branch_dec(&memcg_kmem_enabled_key
);
2924 WARN_ON(page_counter_read(&memcg
->kmem
));
2928 static int memcg_online_kmem(struct mem_cgroup
*memcg
)
2932 static void memcg_offline_kmem(struct mem_cgroup
*memcg
)
2935 static void memcg_free_kmem(struct mem_cgroup
*memcg
)
2938 #endif /* !CONFIG_SLOB */
2940 static int memcg_update_kmem_limit(struct mem_cgroup
*memcg
,
2941 unsigned long limit
)
2945 mutex_lock(&memcg_limit_mutex
);
2946 ret
= page_counter_limit(&memcg
->kmem
, limit
);
2947 mutex_unlock(&memcg_limit_mutex
);
2951 static int memcg_update_tcp_limit(struct mem_cgroup
*memcg
, unsigned long limit
)
2955 mutex_lock(&memcg_limit_mutex
);
2957 ret
= page_counter_limit(&memcg
->tcpmem
, limit
);
2961 if (!memcg
->tcpmem_active
) {
2963 * The active flag needs to be written after the static_key
2964 * update. This is what guarantees that the socket activation
2965 * function is the last one to run. See sock_update_memcg() for
2966 * details, and note that we don't mark any socket as belonging
2967 * to this memcg until that flag is up.
2969 * We need to do this, because static_keys will span multiple
2970 * sites, but we can't control their order. If we mark a socket
2971 * as accounted, but the accounting functions are not patched in
2972 * yet, we'll lose accounting.
2974 * We never race with the readers in sock_update_memcg(),
2975 * because when this value change, the code to process it is not
2978 static_branch_inc(&memcg_sockets_enabled_key
);
2979 memcg
->tcpmem_active
= true;
2982 mutex_unlock(&memcg_limit_mutex
);
2987 * The user of this function is...
2990 static ssize_t
mem_cgroup_write(struct kernfs_open_file
*of
,
2991 char *buf
, size_t nbytes
, loff_t off
)
2993 struct mem_cgroup
*memcg
= mem_cgroup_from_css(of_css(of
));
2994 unsigned long nr_pages
;
2997 buf
= strstrip(buf
);
2998 ret
= page_counter_memparse(buf
, "-1", &nr_pages
);
3002 switch (MEMFILE_ATTR(of_cft(of
)->private)) {
3004 if (mem_cgroup_is_root(memcg
)) { /* Can't set limit on root */
3008 switch (MEMFILE_TYPE(of_cft(of
)->private)) {
3010 ret
= mem_cgroup_resize_limit(memcg
, nr_pages
);
3013 ret
= mem_cgroup_resize_memsw_limit(memcg
, nr_pages
);
3016 ret
= memcg_update_kmem_limit(memcg
, nr_pages
);
3019 ret
= memcg_update_tcp_limit(memcg
, nr_pages
);
3023 case RES_SOFT_LIMIT
:
3024 memcg
->soft_limit
= nr_pages
;
3028 return ret
?: nbytes
;
3031 static ssize_t
mem_cgroup_reset(struct kernfs_open_file
*of
, char *buf
,
3032 size_t nbytes
, loff_t off
)
3034 struct mem_cgroup
*memcg
= mem_cgroup_from_css(of_css(of
));
3035 struct page_counter
*counter
;
3037 switch (MEMFILE_TYPE(of_cft(of
)->private)) {
3039 counter
= &memcg
->memory
;
3042 counter
= &memcg
->memsw
;
3045 counter
= &memcg
->kmem
;
3048 counter
= &memcg
->tcpmem
;
3054 switch (MEMFILE_ATTR(of_cft(of
)->private)) {
3056 page_counter_reset_watermark(counter
);
3059 counter
->failcnt
= 0;
3068 static u64
mem_cgroup_move_charge_read(struct cgroup_subsys_state
*css
,
3071 return mem_cgroup_from_css(css
)->move_charge_at_immigrate
;
3075 static int mem_cgroup_move_charge_write(struct cgroup_subsys_state
*css
,
3076 struct cftype
*cft
, u64 val
)
3078 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
3080 if (val
& ~MOVE_MASK
)
3084 * No kind of locking is needed in here, because ->can_attach() will
3085 * check this value once in the beginning of the process, and then carry
3086 * on with stale data. This means that changes to this value will only
3087 * affect task migrations starting after the change.
3089 memcg
->move_charge_at_immigrate
= val
;
3093 static int mem_cgroup_move_charge_write(struct cgroup_subsys_state
*css
,
3094 struct cftype
*cft
, u64 val
)
3101 static int memcg_numa_stat_show(struct seq_file
*m
, void *v
)
3105 unsigned int lru_mask
;
3108 static const struct numa_stat stats
[] = {
3109 { "total", LRU_ALL
},
3110 { "file", LRU_ALL_FILE
},
3111 { "anon", LRU_ALL_ANON
},
3112 { "unevictable", BIT(LRU_UNEVICTABLE
) },
3114 const struct numa_stat
*stat
;
3117 struct mem_cgroup
*memcg
= mem_cgroup_from_css(seq_css(m
));
3119 for (stat
= stats
; stat
< stats
+ ARRAY_SIZE(stats
); stat
++) {
3120 nr
= mem_cgroup_nr_lru_pages(memcg
, stat
->lru_mask
);
3121 seq_printf(m
, "%s=%lu", stat
->name
, nr
);
3122 for_each_node_state(nid
, N_MEMORY
) {
3123 nr
= mem_cgroup_node_nr_lru_pages(memcg
, nid
,
3125 seq_printf(m
, " N%d=%lu", nid
, nr
);
3130 for (stat
= stats
; stat
< stats
+ ARRAY_SIZE(stats
); stat
++) {
3131 struct mem_cgroup
*iter
;
3134 for_each_mem_cgroup_tree(iter
, memcg
)
3135 nr
+= mem_cgroup_nr_lru_pages(iter
, stat
->lru_mask
);
3136 seq_printf(m
, "hierarchical_%s=%lu", stat
->name
, nr
);
3137 for_each_node_state(nid
, N_MEMORY
) {
3139 for_each_mem_cgroup_tree(iter
, memcg
)
3140 nr
+= mem_cgroup_node_nr_lru_pages(
3141 iter
, nid
, stat
->lru_mask
);
3142 seq_printf(m
, " N%d=%lu", nid
, nr
);
3149 #endif /* CONFIG_NUMA */
3151 static int memcg_stat_show(struct seq_file
*m
, void *v
)
3153 struct mem_cgroup
*memcg
= mem_cgroup_from_css(seq_css(m
));
3154 unsigned long memory
, memsw
;
3155 struct mem_cgroup
*mi
;
3158 BUILD_BUG_ON(ARRAY_SIZE(mem_cgroup_stat_names
) !=
3159 MEM_CGROUP_STAT_NSTATS
);
3160 BUILD_BUG_ON(ARRAY_SIZE(mem_cgroup_events_names
) !=
3161 MEM_CGROUP_EVENTS_NSTATS
);
3162 BUILD_BUG_ON(ARRAY_SIZE(mem_cgroup_lru_names
) != NR_LRU_LISTS
);
3164 for (i
= 0; i
< MEM_CGROUP_STAT_NSTATS
; i
++) {
3165 if (i
== MEM_CGROUP_STAT_SWAP
&& !do_memsw_account())
3167 seq_printf(m
, "%s %lu\n", mem_cgroup_stat_names
[i
],
3168 mem_cgroup_read_stat(memcg
, i
) * PAGE_SIZE
);
3171 for (i
= 0; i
< MEM_CGROUP_EVENTS_NSTATS
; i
++)
3172 seq_printf(m
, "%s %lu\n", mem_cgroup_events_names
[i
],
3173 mem_cgroup_read_events(memcg
, i
));
3175 for (i
= 0; i
< NR_LRU_LISTS
; i
++)
3176 seq_printf(m
, "%s %lu\n", mem_cgroup_lru_names
[i
],
3177 mem_cgroup_nr_lru_pages(memcg
, BIT(i
)) * PAGE_SIZE
);
3179 /* Hierarchical information */
3180 memory
= memsw
= PAGE_COUNTER_MAX
;
3181 for (mi
= memcg
; mi
; mi
= parent_mem_cgroup(mi
)) {
3182 memory
= min(memory
, mi
->memory
.limit
);
3183 memsw
= min(memsw
, mi
->memsw
.limit
);
3185 seq_printf(m
, "hierarchical_memory_limit %llu\n",
3186 (u64
)memory
* PAGE_SIZE
);
3187 if (do_memsw_account())
3188 seq_printf(m
, "hierarchical_memsw_limit %llu\n",
3189 (u64
)memsw
* PAGE_SIZE
);
3191 for (i
= 0; i
< MEM_CGROUP_STAT_NSTATS
; i
++) {
3192 unsigned long long val
= 0;
3194 if (i
== MEM_CGROUP_STAT_SWAP
&& !do_memsw_account())
3196 for_each_mem_cgroup_tree(mi
, memcg
)
3197 val
+= mem_cgroup_read_stat(mi
, i
) * PAGE_SIZE
;
3198 seq_printf(m
, "total_%s %llu\n", mem_cgroup_stat_names
[i
], val
);
3201 for (i
= 0; i
< MEM_CGROUP_EVENTS_NSTATS
; i
++) {
3202 unsigned long long val
= 0;
3204 for_each_mem_cgroup_tree(mi
, memcg
)
3205 val
+= mem_cgroup_read_events(mi
, i
);
3206 seq_printf(m
, "total_%s %llu\n",
3207 mem_cgroup_events_names
[i
], val
);
3210 for (i
= 0; i
< NR_LRU_LISTS
; i
++) {
3211 unsigned long long val
= 0;
3213 for_each_mem_cgroup_tree(mi
, memcg
)
3214 val
+= mem_cgroup_nr_lru_pages(mi
, BIT(i
)) * PAGE_SIZE
;
3215 seq_printf(m
, "total_%s %llu\n", mem_cgroup_lru_names
[i
], val
);
3218 #ifdef CONFIG_DEBUG_VM
3221 struct mem_cgroup_per_zone
*mz
;
3222 struct zone_reclaim_stat
*rstat
;
3223 unsigned long recent_rotated
[2] = {0, 0};
3224 unsigned long recent_scanned
[2] = {0, 0};
3226 for_each_online_node(nid
)
3227 for (zid
= 0; zid
< MAX_NR_ZONES
; zid
++) {
3228 mz
= &memcg
->nodeinfo
[nid
]->zoneinfo
[zid
];
3229 rstat
= &mz
->lruvec
.reclaim_stat
;
3231 recent_rotated
[0] += rstat
->recent_rotated
[0];
3232 recent_rotated
[1] += rstat
->recent_rotated
[1];
3233 recent_scanned
[0] += rstat
->recent_scanned
[0];
3234 recent_scanned
[1] += rstat
->recent_scanned
[1];
3236 seq_printf(m
, "recent_rotated_anon %lu\n", recent_rotated
[0]);
3237 seq_printf(m
, "recent_rotated_file %lu\n", recent_rotated
[1]);
3238 seq_printf(m
, "recent_scanned_anon %lu\n", recent_scanned
[0]);
3239 seq_printf(m
, "recent_scanned_file %lu\n", recent_scanned
[1]);
3246 static u64
mem_cgroup_swappiness_read(struct cgroup_subsys_state
*css
,
3249 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
3251 return mem_cgroup_swappiness(memcg
);
3254 static int mem_cgroup_swappiness_write(struct cgroup_subsys_state
*css
,
3255 struct cftype
*cft
, u64 val
)
3257 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
3263 memcg
->swappiness
= val
;
3265 vm_swappiness
= val
;
3270 static void __mem_cgroup_threshold(struct mem_cgroup
*memcg
, bool swap
)
3272 struct mem_cgroup_threshold_ary
*t
;
3273 unsigned long usage
;
3278 t
= rcu_dereference(memcg
->thresholds
.primary
);
3280 t
= rcu_dereference(memcg
->memsw_thresholds
.primary
);
3285 usage
= mem_cgroup_usage(memcg
, swap
);
3288 * current_threshold points to threshold just below or equal to usage.
3289 * If it's not true, a threshold was crossed after last
3290 * call of __mem_cgroup_threshold().
3292 i
= t
->current_threshold
;
3295 * Iterate backward over array of thresholds starting from
3296 * current_threshold and check if a threshold is crossed.
3297 * If none of thresholds below usage is crossed, we read
3298 * only one element of the array here.
3300 for (; i
>= 0 && unlikely(t
->entries
[i
].threshold
> usage
); i
--)
3301 eventfd_signal(t
->entries
[i
].eventfd
, 1);
3303 /* i = current_threshold + 1 */
3307 * Iterate forward over array of thresholds starting from
3308 * current_threshold+1 and check if a threshold is crossed.
3309 * If none of thresholds above usage is crossed, we read
3310 * only one element of the array here.
3312 for (; i
< t
->size
&& unlikely(t
->entries
[i
].threshold
<= usage
); i
++)
3313 eventfd_signal(t
->entries
[i
].eventfd
, 1);
3315 /* Update current_threshold */
3316 t
->current_threshold
= i
- 1;
3321 static void mem_cgroup_threshold(struct mem_cgroup
*memcg
)
3324 __mem_cgroup_threshold(memcg
, false);
3325 if (do_memsw_account())
3326 __mem_cgroup_threshold(memcg
, true);
3328 memcg
= parent_mem_cgroup(memcg
);
3332 static int compare_thresholds(const void *a
, const void *b
)
3334 const struct mem_cgroup_threshold
*_a
= a
;
3335 const struct mem_cgroup_threshold
*_b
= b
;
3337 if (_a
->threshold
> _b
->threshold
)
3340 if (_a
->threshold
< _b
->threshold
)
3346 static int mem_cgroup_oom_notify_cb(struct mem_cgroup
*memcg
)
3348 struct mem_cgroup_eventfd_list
*ev
;
3350 spin_lock(&memcg_oom_lock
);
3352 list_for_each_entry(ev
, &memcg
->oom_notify
, list
)
3353 eventfd_signal(ev
->eventfd
, 1);
3355 spin_unlock(&memcg_oom_lock
);
3359 static void mem_cgroup_oom_notify(struct mem_cgroup
*memcg
)
3361 struct mem_cgroup
*iter
;
3363 for_each_mem_cgroup_tree(iter
, memcg
)
3364 mem_cgroup_oom_notify_cb(iter
);
3367 static int __mem_cgroup_usage_register_event(struct mem_cgroup
*memcg
,
3368 struct eventfd_ctx
*eventfd
, const char *args
, enum res_type type
)
3370 struct mem_cgroup_thresholds
*thresholds
;
3371 struct mem_cgroup_threshold_ary
*new;
3372 unsigned long threshold
;
3373 unsigned long usage
;
3376 ret
= page_counter_memparse(args
, "-1", &threshold
);
3380 mutex_lock(&memcg
->thresholds_lock
);
3383 thresholds
= &memcg
->thresholds
;
3384 usage
= mem_cgroup_usage(memcg
, false);
3385 } else if (type
== _MEMSWAP
) {
3386 thresholds
= &memcg
->memsw_thresholds
;
3387 usage
= mem_cgroup_usage(memcg
, true);
3391 /* Check if a threshold crossed before adding a new one */
3392 if (thresholds
->primary
)
3393 __mem_cgroup_threshold(memcg
, type
== _MEMSWAP
);
3395 size
= thresholds
->primary
? thresholds
->primary
->size
+ 1 : 1;
3397 /* Allocate memory for new array of thresholds */
3398 new = kmalloc(sizeof(*new) + size
* sizeof(struct mem_cgroup_threshold
),
3406 /* Copy thresholds (if any) to new array */
3407 if (thresholds
->primary
) {
3408 memcpy(new->entries
, thresholds
->primary
->entries
, (size
- 1) *
3409 sizeof(struct mem_cgroup_threshold
));
3412 /* Add new threshold */
3413 new->entries
[size
- 1].eventfd
= eventfd
;
3414 new->entries
[size
- 1].threshold
= threshold
;
3416 /* Sort thresholds. Registering of new threshold isn't time-critical */
3417 sort(new->entries
, size
, sizeof(struct mem_cgroup_threshold
),
3418 compare_thresholds
, NULL
);
3420 /* Find current threshold */
3421 new->current_threshold
= -1;
3422 for (i
= 0; i
< size
; i
++) {
3423 if (new->entries
[i
].threshold
<= usage
) {
3425 * new->current_threshold will not be used until
3426 * rcu_assign_pointer(), so it's safe to increment
3429 ++new->current_threshold
;
3434 /* Free old spare buffer and save old primary buffer as spare */
3435 kfree(thresholds
->spare
);
3436 thresholds
->spare
= thresholds
->primary
;
3438 rcu_assign_pointer(thresholds
->primary
, new);
3440 /* To be sure that nobody uses thresholds */
3444 mutex_unlock(&memcg
->thresholds_lock
);
3449 static int mem_cgroup_usage_register_event(struct mem_cgroup
*memcg
,
3450 struct eventfd_ctx
*eventfd
, const char *args
)
3452 return __mem_cgroup_usage_register_event(memcg
, eventfd
, args
, _MEM
);
3455 static int memsw_cgroup_usage_register_event(struct mem_cgroup
*memcg
,
3456 struct eventfd_ctx
*eventfd
, const char *args
)
3458 return __mem_cgroup_usage_register_event(memcg
, eventfd
, args
, _MEMSWAP
);
3461 static void __mem_cgroup_usage_unregister_event(struct mem_cgroup
*memcg
,
3462 struct eventfd_ctx
*eventfd
, enum res_type type
)
3464 struct mem_cgroup_thresholds
*thresholds
;
3465 struct mem_cgroup_threshold_ary
*new;
3466 unsigned long usage
;
3469 mutex_lock(&memcg
->thresholds_lock
);
3472 thresholds
= &memcg
->thresholds
;
3473 usage
= mem_cgroup_usage(memcg
, false);
3474 } else if (type
== _MEMSWAP
) {
3475 thresholds
= &memcg
->memsw_thresholds
;
3476 usage
= mem_cgroup_usage(memcg
, true);
3480 if (!thresholds
->primary
)
3483 /* Check if a threshold crossed before removing */
3484 __mem_cgroup_threshold(memcg
, type
== _MEMSWAP
);
3486 /* Calculate new number of threshold */
3488 for (i
= 0; i
< thresholds
->primary
->size
; i
++) {
3489 if (thresholds
->primary
->entries
[i
].eventfd
!= eventfd
)
3493 new = thresholds
->spare
;
3495 /* Set thresholds array to NULL if we don't have thresholds */
3504 /* Copy thresholds and find current threshold */
3505 new->current_threshold
= -1;
3506 for (i
= 0, j
= 0; i
< thresholds
->primary
->size
; i
++) {
3507 if (thresholds
->primary
->entries
[i
].eventfd
== eventfd
)
3510 new->entries
[j
] = thresholds
->primary
->entries
[i
];
3511 if (new->entries
[j
].threshold
<= usage
) {
3513 * new->current_threshold will not be used
3514 * until rcu_assign_pointer(), so it's safe to increment
3517 ++new->current_threshold
;
3523 /* Swap primary and spare array */
3524 thresholds
->spare
= thresholds
->primary
;
3526 rcu_assign_pointer(thresholds
->primary
, new);
3528 /* To be sure that nobody uses thresholds */
3531 /* If all events are unregistered, free the spare array */
3533 kfree(thresholds
->spare
);
3534 thresholds
->spare
= NULL
;
3537 mutex_unlock(&memcg
->thresholds_lock
);
3540 static void mem_cgroup_usage_unregister_event(struct mem_cgroup
*memcg
,
3541 struct eventfd_ctx
*eventfd
)
3543 return __mem_cgroup_usage_unregister_event(memcg
, eventfd
, _MEM
);
3546 static void memsw_cgroup_usage_unregister_event(struct mem_cgroup
*memcg
,
3547 struct eventfd_ctx
*eventfd
)
3549 return __mem_cgroup_usage_unregister_event(memcg
, eventfd
, _MEMSWAP
);
3552 static int mem_cgroup_oom_register_event(struct mem_cgroup
*memcg
,
3553 struct eventfd_ctx
*eventfd
, const char *args
)
3555 struct mem_cgroup_eventfd_list
*event
;
3557 event
= kmalloc(sizeof(*event
), GFP_KERNEL
);
3561 spin_lock(&memcg_oom_lock
);
3563 event
->eventfd
= eventfd
;
3564 list_add(&event
->list
, &memcg
->oom_notify
);
3566 /* already in OOM ? */
3567 if (memcg
->under_oom
)
3568 eventfd_signal(eventfd
, 1);
3569 spin_unlock(&memcg_oom_lock
);
3574 static void mem_cgroup_oom_unregister_event(struct mem_cgroup
*memcg
,
3575 struct eventfd_ctx
*eventfd
)
3577 struct mem_cgroup_eventfd_list
*ev
, *tmp
;
3579 spin_lock(&memcg_oom_lock
);
3581 list_for_each_entry_safe(ev
, tmp
, &memcg
->oom_notify
, list
) {
3582 if (ev
->eventfd
== eventfd
) {
3583 list_del(&ev
->list
);
3588 spin_unlock(&memcg_oom_lock
);
3591 static int mem_cgroup_oom_control_read(struct seq_file
*sf
, void *v
)
3593 struct mem_cgroup
*memcg
= mem_cgroup_from_css(seq_css(sf
));
3595 seq_printf(sf
, "oom_kill_disable %d\n", memcg
->oom_kill_disable
);
3596 seq_printf(sf
, "under_oom %d\n", (bool)memcg
->under_oom
);
3600 static int mem_cgroup_oom_control_write(struct cgroup_subsys_state
*css
,
3601 struct cftype
*cft
, u64 val
)
3603 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
3605 /* cannot set to root cgroup and only 0 and 1 are allowed */
3606 if (!css
->parent
|| !((val
== 0) || (val
== 1)))
3609 memcg
->oom_kill_disable
= val
;
3611 memcg_oom_recover(memcg
);
3616 #ifdef CONFIG_CGROUP_WRITEBACK
3618 struct list_head
*mem_cgroup_cgwb_list(struct mem_cgroup
*memcg
)
3620 return &memcg
->cgwb_list
;
3623 static int memcg_wb_domain_init(struct mem_cgroup
*memcg
, gfp_t gfp
)
3625 return wb_domain_init(&memcg
->cgwb_domain
, gfp
);
3628 static void memcg_wb_domain_exit(struct mem_cgroup
*memcg
)
3630 wb_domain_exit(&memcg
->cgwb_domain
);
3633 static void memcg_wb_domain_size_changed(struct mem_cgroup
*memcg
)
3635 wb_domain_size_changed(&memcg
->cgwb_domain
);
3638 struct wb_domain
*mem_cgroup_wb_domain(struct bdi_writeback
*wb
)
3640 struct mem_cgroup
*memcg
= mem_cgroup_from_css(wb
->memcg_css
);
3642 if (!memcg
->css
.parent
)
3645 return &memcg
->cgwb_domain
;
3649 * mem_cgroup_wb_stats - retrieve writeback related stats from its memcg
3650 * @wb: bdi_writeback in question
3651 * @pfilepages: out parameter for number of file pages
3652 * @pheadroom: out parameter for number of allocatable pages according to memcg
3653 * @pdirty: out parameter for number of dirty pages
3654 * @pwriteback: out parameter for number of pages under writeback
3656 * Determine the numbers of file, headroom, dirty, and writeback pages in
3657 * @wb's memcg. File, dirty and writeback are self-explanatory. Headroom
3658 * is a bit more involved.
3660 * A memcg's headroom is "min(max, high) - used". In the hierarchy, the
3661 * headroom is calculated as the lowest headroom of itself and the
3662 * ancestors. Note that this doesn't consider the actual amount of
3663 * available memory in the system. The caller should further cap
3664 * *@pheadroom accordingly.
3666 void mem_cgroup_wb_stats(struct bdi_writeback
*wb
, unsigned long *pfilepages
,
3667 unsigned long *pheadroom
, unsigned long *pdirty
,
3668 unsigned long *pwriteback
)
3670 struct mem_cgroup
*memcg
= mem_cgroup_from_css(wb
->memcg_css
);
3671 struct mem_cgroup
*parent
;
3673 *pdirty
= mem_cgroup_read_stat(memcg
, MEM_CGROUP_STAT_DIRTY
);
3675 /* this should eventually include NR_UNSTABLE_NFS */
3676 *pwriteback
= mem_cgroup_read_stat(memcg
, MEM_CGROUP_STAT_WRITEBACK
);
3677 *pfilepages
= mem_cgroup_nr_lru_pages(memcg
, (1 << LRU_INACTIVE_FILE
) |
3678 (1 << LRU_ACTIVE_FILE
));
3679 *pheadroom
= PAGE_COUNTER_MAX
;
3681 while ((parent
= parent_mem_cgroup(memcg
))) {
3682 unsigned long ceiling
= min(memcg
->memory
.limit
, memcg
->high
);
3683 unsigned long used
= page_counter_read(&memcg
->memory
);
3685 *pheadroom
= min(*pheadroom
, ceiling
- min(ceiling
, used
));
3690 #else /* CONFIG_CGROUP_WRITEBACK */
3692 static int memcg_wb_domain_init(struct mem_cgroup
*memcg
, gfp_t gfp
)
3697 static void memcg_wb_domain_exit(struct mem_cgroup
*memcg
)
3701 static void memcg_wb_domain_size_changed(struct mem_cgroup
*memcg
)
3705 #endif /* CONFIG_CGROUP_WRITEBACK */
3708 * DO NOT USE IN NEW FILES.
3710 * "cgroup.event_control" implementation.
3712 * This is way over-engineered. It tries to support fully configurable
3713 * events for each user. Such level of flexibility is completely
3714 * unnecessary especially in the light of the planned unified hierarchy.
3716 * Please deprecate this and replace with something simpler if at all
3721 * Unregister event and free resources.
3723 * Gets called from workqueue.
3725 static void memcg_event_remove(struct work_struct
*work
)
3727 struct mem_cgroup_event
*event
=
3728 container_of(work
, struct mem_cgroup_event
, remove
);
3729 struct mem_cgroup
*memcg
= event
->memcg
;
3731 remove_wait_queue(event
->wqh
, &event
->wait
);
3733 event
->unregister_event(memcg
, event
->eventfd
);
3735 /* Notify userspace the event is going away. */
3736 eventfd_signal(event
->eventfd
, 1);
3738 eventfd_ctx_put(event
->eventfd
);
3740 css_put(&memcg
->css
);
3744 * Gets called on POLLHUP on eventfd when user closes it.
3746 * Called with wqh->lock held and interrupts disabled.
3748 static int memcg_event_wake(wait_queue_t
*wait
, unsigned mode
,
3749 int sync
, void *key
)
3751 struct mem_cgroup_event
*event
=
3752 container_of(wait
, struct mem_cgroup_event
, wait
);
3753 struct mem_cgroup
*memcg
= event
->memcg
;
3754 unsigned long flags
= (unsigned long)key
;
3756 if (flags
& POLLHUP
) {
3758 * If the event has been detached at cgroup removal, we
3759 * can simply return knowing the other side will cleanup
3762 * We can't race against event freeing since the other
3763 * side will require wqh->lock via remove_wait_queue(),
3766 spin_lock(&memcg
->event_list_lock
);
3767 if (!list_empty(&event
->list
)) {
3768 list_del_init(&event
->list
);
3770 * We are in atomic context, but cgroup_event_remove()
3771 * may sleep, so we have to call it in workqueue.
3773 schedule_work(&event
->remove
);
3775 spin_unlock(&memcg
->event_list_lock
);
3781 static void memcg_event_ptable_queue_proc(struct file
*file
,
3782 wait_queue_head_t
*wqh
, poll_table
*pt
)
3784 struct mem_cgroup_event
*event
=
3785 container_of(pt
, struct mem_cgroup_event
, pt
);
3788 add_wait_queue(wqh
, &event
->wait
);
3792 * DO NOT USE IN NEW FILES.
3794 * Parse input and register new cgroup event handler.
3796 * Input must be in format '<event_fd> <control_fd> <args>'.
3797 * Interpretation of args is defined by control file implementation.
3799 static ssize_t
memcg_write_event_control(struct kernfs_open_file
*of
,
3800 char *buf
, size_t nbytes
, loff_t off
)
3802 struct cgroup_subsys_state
*css
= of_css(of
);
3803 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
3804 struct mem_cgroup_event
*event
;
3805 struct cgroup_subsys_state
*cfile_css
;
3806 unsigned int efd
, cfd
;
3813 buf
= strstrip(buf
);
3815 efd
= simple_strtoul(buf
, &endp
, 10);
3820 cfd
= simple_strtoul(buf
, &endp
, 10);
3821 if ((*endp
!= ' ') && (*endp
!= '\0'))
3825 event
= kzalloc(sizeof(*event
), GFP_KERNEL
);
3829 event
->memcg
= memcg
;
3830 INIT_LIST_HEAD(&event
->list
);
3831 init_poll_funcptr(&event
->pt
, memcg_event_ptable_queue_proc
);
3832 init_waitqueue_func_entry(&event
->wait
, memcg_event_wake
);
3833 INIT_WORK(&event
->remove
, memcg_event_remove
);
3841 event
->eventfd
= eventfd_ctx_fileget(efile
.file
);
3842 if (IS_ERR(event
->eventfd
)) {
3843 ret
= PTR_ERR(event
->eventfd
);
3850 goto out_put_eventfd
;
3853 /* the process need read permission on control file */
3854 /* AV: shouldn't we check that it's been opened for read instead? */
3855 ret
= inode_permission(file_inode(cfile
.file
), MAY_READ
);
3860 * Determine the event callbacks and set them in @event. This used
3861 * to be done via struct cftype but cgroup core no longer knows
3862 * about these events. The following is crude but the whole thing
3863 * is for compatibility anyway.
3865 * DO NOT ADD NEW FILES.
3867 name
= cfile
.file
->f_path
.dentry
->d_name
.name
;
3869 if (!strcmp(name
, "memory.usage_in_bytes")) {
3870 event
->register_event
= mem_cgroup_usage_register_event
;
3871 event
->unregister_event
= mem_cgroup_usage_unregister_event
;
3872 } else if (!strcmp(name
, "memory.oom_control")) {
3873 event
->register_event
= mem_cgroup_oom_register_event
;
3874 event
->unregister_event
= mem_cgroup_oom_unregister_event
;
3875 } else if (!strcmp(name
, "memory.pressure_level")) {
3876 event
->register_event
= vmpressure_register_event
;
3877 event
->unregister_event
= vmpressure_unregister_event
;
3878 } else if (!strcmp(name
, "memory.memsw.usage_in_bytes")) {
3879 event
->register_event
= memsw_cgroup_usage_register_event
;
3880 event
->unregister_event
= memsw_cgroup_usage_unregister_event
;
3887 * Verify @cfile should belong to @css. Also, remaining events are
3888 * automatically removed on cgroup destruction but the removal is
3889 * asynchronous, so take an extra ref on @css.
3891 cfile_css
= css_tryget_online_from_dir(cfile
.file
->f_path
.dentry
->d_parent
,
3892 &memory_cgrp_subsys
);
3894 if (IS_ERR(cfile_css
))
3896 if (cfile_css
!= css
) {
3901 ret
= event
->register_event(memcg
, event
->eventfd
, buf
);
3905 efile
.file
->f_op
->poll(efile
.file
, &event
->pt
);
3907 spin_lock(&memcg
->event_list_lock
);
3908 list_add(&event
->list
, &memcg
->event_list
);
3909 spin_unlock(&memcg
->event_list_lock
);
3921 eventfd_ctx_put(event
->eventfd
);
3930 static struct cftype mem_cgroup_legacy_files
[] = {
3932 .name
= "usage_in_bytes",
3933 .private = MEMFILE_PRIVATE(_MEM
, RES_USAGE
),
3934 .read_u64
= mem_cgroup_read_u64
,
3937 .name
= "max_usage_in_bytes",
3938 .private = MEMFILE_PRIVATE(_MEM
, RES_MAX_USAGE
),
3939 .write
= mem_cgroup_reset
,
3940 .read_u64
= mem_cgroup_read_u64
,
3943 .name
= "limit_in_bytes",
3944 .private = MEMFILE_PRIVATE(_MEM
, RES_LIMIT
),
3945 .write
= mem_cgroup_write
,
3946 .read_u64
= mem_cgroup_read_u64
,
3949 .name
= "soft_limit_in_bytes",
3950 .private = MEMFILE_PRIVATE(_MEM
, RES_SOFT_LIMIT
),
3951 .write
= mem_cgroup_write
,
3952 .read_u64
= mem_cgroup_read_u64
,
3956 .private = MEMFILE_PRIVATE(_MEM
, RES_FAILCNT
),
3957 .write
= mem_cgroup_reset
,
3958 .read_u64
= mem_cgroup_read_u64
,
3962 .seq_show
= memcg_stat_show
,
3965 .name
= "force_empty",
3966 .write
= mem_cgroup_force_empty_write
,
3969 .name
= "use_hierarchy",
3970 .write_u64
= mem_cgroup_hierarchy_write
,
3971 .read_u64
= mem_cgroup_hierarchy_read
,
3974 .name
= "cgroup.event_control", /* XXX: for compat */
3975 .write
= memcg_write_event_control
,
3976 .flags
= CFTYPE_NO_PREFIX
| CFTYPE_WORLD_WRITABLE
,
3979 .name
= "swappiness",
3980 .read_u64
= mem_cgroup_swappiness_read
,
3981 .write_u64
= mem_cgroup_swappiness_write
,
3984 .name
= "move_charge_at_immigrate",
3985 .read_u64
= mem_cgroup_move_charge_read
,
3986 .write_u64
= mem_cgroup_move_charge_write
,
3989 .name
= "oom_control",
3990 .seq_show
= mem_cgroup_oom_control_read
,
3991 .write_u64
= mem_cgroup_oom_control_write
,
3992 .private = MEMFILE_PRIVATE(_OOM_TYPE
, OOM_CONTROL
),
3995 .name
= "pressure_level",
3999 .name
= "numa_stat",
4000 .seq_show
= memcg_numa_stat_show
,
4004 .name
= "kmem.limit_in_bytes",
4005 .private = MEMFILE_PRIVATE(_KMEM
, RES_LIMIT
),
4006 .write
= mem_cgroup_write
,
4007 .read_u64
= mem_cgroup_read_u64
,
4010 .name
= "kmem.usage_in_bytes",
4011 .private = MEMFILE_PRIVATE(_KMEM
, RES_USAGE
),
4012 .read_u64
= mem_cgroup_read_u64
,
4015 .name
= "kmem.failcnt",
4016 .private = MEMFILE_PRIVATE(_KMEM
, RES_FAILCNT
),
4017 .write
= mem_cgroup_reset
,
4018 .read_u64
= mem_cgroup_read_u64
,
4021 .name
= "kmem.max_usage_in_bytes",
4022 .private = MEMFILE_PRIVATE(_KMEM
, RES_MAX_USAGE
),
4023 .write
= mem_cgroup_reset
,
4024 .read_u64
= mem_cgroup_read_u64
,
4026 #ifdef CONFIG_SLABINFO
4028 .name
= "kmem.slabinfo",
4029 .seq_start
= slab_start
,
4030 .seq_next
= slab_next
,
4031 .seq_stop
= slab_stop
,
4032 .seq_show
= memcg_slab_show
,
4036 .name
= "kmem.tcp.limit_in_bytes",
4037 .private = MEMFILE_PRIVATE(_TCP
, RES_LIMIT
),
4038 .write
= mem_cgroup_write
,
4039 .read_u64
= mem_cgroup_read_u64
,
4042 .name
= "kmem.tcp.usage_in_bytes",
4043 .private = MEMFILE_PRIVATE(_TCP
, RES_USAGE
),
4044 .read_u64
= mem_cgroup_read_u64
,
4047 .name
= "kmem.tcp.failcnt",
4048 .private = MEMFILE_PRIVATE(_TCP
, RES_FAILCNT
),
4049 .write
= mem_cgroup_reset
,
4050 .read_u64
= mem_cgroup_read_u64
,
4053 .name
= "kmem.tcp.max_usage_in_bytes",
4054 .private = MEMFILE_PRIVATE(_TCP
, RES_MAX_USAGE
),
4055 .write
= mem_cgroup_reset
,
4056 .read_u64
= mem_cgroup_read_u64
,
4058 { }, /* terminate */
4062 * Private memory cgroup IDR
4064 * Swap-out records and page cache shadow entries need to store memcg
4065 * references in constrained space, so we maintain an ID space that is
4066 * limited to 16 bit (MEM_CGROUP_ID_MAX), limiting the total number of
4067 * memory-controlled cgroups to 64k.
4069 * However, there usually are many references to the oflline CSS after
4070 * the cgroup has been destroyed, such as page cache or reclaimable
4071 * slab objects, that don't need to hang on to the ID. We want to keep
4072 * those dead CSS from occupying IDs, or we might quickly exhaust the
4073 * relatively small ID space and prevent the creation of new cgroups
4074 * even when there are much fewer than 64k cgroups - possibly none.
4076 * Maintain a private 16-bit ID space for memcg, and allow the ID to
4077 * be freed and recycled when it's no longer needed, which is usually
4078 * when the CSS is offlined.
4080 * The only exception to that are records of swapped out tmpfs/shmem
4081 * pages that need to be attributed to live ancestors on swapin. But
4082 * those references are manageable from userspace.
4085 static DEFINE_IDR(mem_cgroup_idr
);
4087 static void mem_cgroup_id_get(struct mem_cgroup
*memcg
)
4089 atomic_inc(&memcg
->id
.ref
);
4092 static void mem_cgroup_id_put(struct mem_cgroup
*memcg
)
4094 if (atomic_dec_and_test(&memcg
->id
.ref
)) {
4095 idr_remove(&mem_cgroup_idr
, memcg
->id
.id
);
4098 /* Memcg ID pins CSS */
4099 css_put(&memcg
->css
);
4104 * mem_cgroup_from_id - look up a memcg from a memcg id
4105 * @id: the memcg id to look up
4107 * Caller must hold rcu_read_lock().
4109 struct mem_cgroup
*mem_cgroup_from_id(unsigned short id
)
4111 WARN_ON_ONCE(!rcu_read_lock_held());
4112 return idr_find(&mem_cgroup_idr
, id
);
4115 static int alloc_mem_cgroup_per_zone_info(struct mem_cgroup
*memcg
, int node
)
4117 struct mem_cgroup_per_node
*pn
;
4118 struct mem_cgroup_per_zone
*mz
;
4119 int zone
, tmp
= node
;
4121 * This routine is called against possible nodes.
4122 * But it's BUG to call kmalloc() against offline node.
4124 * TODO: this routine can waste much memory for nodes which will
4125 * never be onlined. It's better to use memory hotplug callback
4128 if (!node_state(node
, N_NORMAL_MEMORY
))
4130 pn
= kzalloc_node(sizeof(*pn
), GFP_KERNEL
, tmp
);
4134 for (zone
= 0; zone
< MAX_NR_ZONES
; zone
++) {
4135 mz
= &pn
->zoneinfo
[zone
];
4136 lruvec_init(&mz
->lruvec
);
4137 mz
->usage_in_excess
= 0;
4138 mz
->on_tree
= false;
4141 memcg
->nodeinfo
[node
] = pn
;
4145 static void free_mem_cgroup_per_zone_info(struct mem_cgroup
*memcg
, int node
)
4147 kfree(memcg
->nodeinfo
[node
]);
4150 static void mem_cgroup_free(struct mem_cgroup
*memcg
)
4154 memcg_wb_domain_exit(memcg
);
4156 free_mem_cgroup_per_zone_info(memcg
, node
);
4157 free_percpu(memcg
->stat
);
4161 static struct mem_cgroup
*mem_cgroup_alloc(void)
4163 struct mem_cgroup
*memcg
;
4167 size
= sizeof(struct mem_cgroup
);
4168 size
+= nr_node_ids
* sizeof(struct mem_cgroup_per_node
*);
4170 memcg
= kzalloc(size
, GFP_KERNEL
);
4174 memcg
->id
.id
= idr_alloc(&mem_cgroup_idr
, NULL
,
4175 1, MEM_CGROUP_ID_MAX
,
4177 if (memcg
->id
.id
< 0)
4180 memcg
->stat
= alloc_percpu(struct mem_cgroup_stat_cpu
);
4185 if (alloc_mem_cgroup_per_zone_info(memcg
, node
))
4188 if (memcg_wb_domain_init(memcg
, GFP_KERNEL
))
4191 INIT_WORK(&memcg
->high_work
, high_work_func
);
4192 memcg
->last_scanned_node
= MAX_NUMNODES
;
4193 INIT_LIST_HEAD(&memcg
->oom_notify
);
4194 mutex_init(&memcg
->thresholds_lock
);
4195 spin_lock_init(&memcg
->move_lock
);
4196 vmpressure_init(&memcg
->vmpressure
);
4197 INIT_LIST_HEAD(&memcg
->event_list
);
4198 spin_lock_init(&memcg
->event_list_lock
);
4199 memcg
->socket_pressure
= jiffies
;
4201 memcg
->kmemcg_id
= -1;
4203 #ifdef CONFIG_CGROUP_WRITEBACK
4204 INIT_LIST_HEAD(&memcg
->cgwb_list
);
4206 idr_replace(&mem_cgroup_idr
, memcg
, memcg
->id
.id
);
4209 if (memcg
->id
.id
> 0)
4210 idr_remove(&mem_cgroup_idr
, memcg
->id
.id
);
4211 mem_cgroup_free(memcg
);
4215 static struct cgroup_subsys_state
* __ref
4216 mem_cgroup_css_alloc(struct cgroup_subsys_state
*parent_css
)
4218 struct mem_cgroup
*parent
= mem_cgroup_from_css(parent_css
);
4219 struct mem_cgroup
*memcg
;
4220 long error
= -ENOMEM
;
4222 memcg
= mem_cgroup_alloc();
4224 return ERR_PTR(error
);
4226 memcg
->high
= PAGE_COUNTER_MAX
;
4227 memcg
->soft_limit
= PAGE_COUNTER_MAX
;
4229 memcg
->swappiness
= mem_cgroup_swappiness(parent
);
4230 memcg
->oom_kill_disable
= parent
->oom_kill_disable
;
4232 if (parent
&& parent
->use_hierarchy
) {
4233 memcg
->use_hierarchy
= true;
4234 page_counter_init(&memcg
->memory
, &parent
->memory
);
4235 page_counter_init(&memcg
->swap
, &parent
->swap
);
4236 page_counter_init(&memcg
->memsw
, &parent
->memsw
);
4237 page_counter_init(&memcg
->kmem
, &parent
->kmem
);
4238 page_counter_init(&memcg
->tcpmem
, &parent
->tcpmem
);
4240 page_counter_init(&memcg
->memory
, NULL
);
4241 page_counter_init(&memcg
->swap
, NULL
);
4242 page_counter_init(&memcg
->memsw
, NULL
);
4243 page_counter_init(&memcg
->kmem
, NULL
);
4244 page_counter_init(&memcg
->tcpmem
, NULL
);
4246 * Deeper hierachy with use_hierarchy == false doesn't make
4247 * much sense so let cgroup subsystem know about this
4248 * unfortunate state in our controller.
4250 if (parent
!= root_mem_cgroup
)
4251 memory_cgrp_subsys
.broken_hierarchy
= true;
4254 /* The following stuff does not apply to the root */
4256 root_mem_cgroup
= memcg
;
4260 error
= memcg_online_kmem(memcg
);
4264 if (cgroup_subsys_on_dfl(memory_cgrp_subsys
) && !cgroup_memory_nosocket
)
4265 static_branch_inc(&memcg_sockets_enabled_key
);
4269 mem_cgroup_free(memcg
);
4270 return ERR_PTR(-ENOMEM
);
4273 static int mem_cgroup_css_online(struct cgroup_subsys_state
*css
)
4275 /* Online state pins memcg ID, memcg ID pins CSS */
4276 mem_cgroup_id_get(mem_cgroup_from_css(css
));
4281 static void mem_cgroup_css_offline(struct cgroup_subsys_state
*css
)
4283 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
4284 struct mem_cgroup_event
*event
, *tmp
;
4287 * Unregister events and notify userspace.
4288 * Notify userspace about cgroup removing only after rmdir of cgroup
4289 * directory to avoid race between userspace and kernelspace.
4291 spin_lock(&memcg
->event_list_lock
);
4292 list_for_each_entry_safe(event
, tmp
, &memcg
->event_list
, list
) {
4293 list_del_init(&event
->list
);
4294 schedule_work(&event
->remove
);
4296 spin_unlock(&memcg
->event_list_lock
);
4298 memcg_offline_kmem(memcg
);
4299 wb_memcg_offline(memcg
);
4301 mem_cgroup_id_put(memcg
);
4304 static void mem_cgroup_css_released(struct cgroup_subsys_state
*css
)
4306 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
4308 invalidate_reclaim_iterators(memcg
);
4311 static void mem_cgroup_css_free(struct cgroup_subsys_state
*css
)
4313 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
4315 if (cgroup_subsys_on_dfl(memory_cgrp_subsys
) && !cgroup_memory_nosocket
)
4316 static_branch_dec(&memcg_sockets_enabled_key
);
4318 if (!cgroup_subsys_on_dfl(memory_cgrp_subsys
) && memcg
->tcpmem_active
)
4319 static_branch_dec(&memcg_sockets_enabled_key
);
4321 vmpressure_cleanup(&memcg
->vmpressure
);
4322 cancel_work_sync(&memcg
->high_work
);
4323 mem_cgroup_remove_from_trees(memcg
);
4324 memcg_free_kmem(memcg
);
4325 mem_cgroup_free(memcg
);
4329 * mem_cgroup_css_reset - reset the states of a mem_cgroup
4330 * @css: the target css
4332 * Reset the states of the mem_cgroup associated with @css. This is
4333 * invoked when the userland requests disabling on the default hierarchy
4334 * but the memcg is pinned through dependency. The memcg should stop
4335 * applying policies and should revert to the vanilla state as it may be
4336 * made visible again.
4338 * The current implementation only resets the essential configurations.
4339 * This needs to be expanded to cover all the visible parts.
4341 static void mem_cgroup_css_reset(struct cgroup_subsys_state
*css
)
4343 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
4345 page_counter_limit(&memcg
->memory
, PAGE_COUNTER_MAX
);
4346 page_counter_limit(&memcg
->swap
, PAGE_COUNTER_MAX
);
4347 page_counter_limit(&memcg
->memsw
, PAGE_COUNTER_MAX
);
4348 page_counter_limit(&memcg
->kmem
, PAGE_COUNTER_MAX
);
4349 page_counter_limit(&memcg
->tcpmem
, PAGE_COUNTER_MAX
);
4351 memcg
->high
= PAGE_COUNTER_MAX
;
4352 memcg
->soft_limit
= PAGE_COUNTER_MAX
;
4353 memcg_wb_domain_size_changed(memcg
);
4357 /* Handlers for move charge at task migration. */
4358 static int mem_cgroup_do_precharge(unsigned long count
)
4362 /* Try a single bulk charge without reclaim first, kswapd may wake */
4363 ret
= try_charge(mc
.to
, GFP_KERNEL
& ~__GFP_DIRECT_RECLAIM
, count
);
4365 mc
.precharge
+= count
;
4369 /* Try charges one by one with reclaim */
4371 ret
= try_charge(mc
.to
, GFP_KERNEL
& ~__GFP_NORETRY
, 1);
4385 enum mc_target_type
{
4391 static struct page
*mc_handle_present_pte(struct vm_area_struct
*vma
,
4392 unsigned long addr
, pte_t ptent
)
4394 struct page
*page
= vm_normal_page(vma
, addr
, ptent
);
4396 if (!page
|| !page_mapped(page
))
4398 if (PageAnon(page
)) {
4399 if (!(mc
.flags
& MOVE_ANON
))
4402 if (!(mc
.flags
& MOVE_FILE
))
4405 if (!get_page_unless_zero(page
))
4412 static struct page
*mc_handle_swap_pte(struct vm_area_struct
*vma
,
4413 pte_t ptent
, swp_entry_t
*entry
)
4415 struct page
*page
= NULL
;
4416 swp_entry_t ent
= pte_to_swp_entry(ptent
);
4418 if (!(mc
.flags
& MOVE_ANON
) || non_swap_entry(ent
))
4421 * Because lookup_swap_cache() updates some statistics counter,
4422 * we call find_get_page() with swapper_space directly.
4424 page
= find_get_page(swap_address_space(ent
), ent
.val
);
4425 if (do_memsw_account())
4426 entry
->val
= ent
.val
;
4431 static struct page
*mc_handle_swap_pte(struct vm_area_struct
*vma
,
4432 pte_t ptent
, swp_entry_t
*entry
)
4438 static struct page
*mc_handle_file_pte(struct vm_area_struct
*vma
,
4439 unsigned long addr
, pte_t ptent
, swp_entry_t
*entry
)
4441 struct page
*page
= NULL
;
4442 struct address_space
*mapping
;
4445 if (!vma
->vm_file
) /* anonymous vma */
4447 if (!(mc
.flags
& MOVE_FILE
))
4450 mapping
= vma
->vm_file
->f_mapping
;
4451 pgoff
= linear_page_index(vma
, addr
);
4453 /* page is moved even if it's not RSS of this task(page-faulted). */
4455 /* shmem/tmpfs may report page out on swap: account for that too. */
4456 if (shmem_mapping(mapping
)) {
4457 page
= find_get_entry(mapping
, pgoff
);
4458 if (radix_tree_exceptional_entry(page
)) {
4459 swp_entry_t swp
= radix_to_swp_entry(page
);
4460 if (do_memsw_account())
4462 page
= find_get_page(swap_address_space(swp
), swp
.val
);
4465 page
= find_get_page(mapping
, pgoff
);
4467 page
= find_get_page(mapping
, pgoff
);
4473 * mem_cgroup_move_account - move account of the page
4475 * @nr_pages: number of regular pages (>1 for huge pages)
4476 * @from: mem_cgroup which the page is moved from.
4477 * @to: mem_cgroup which the page is moved to. @from != @to.
4479 * The caller must make sure the page is not on LRU (isolate_page() is useful.)
4481 * This function doesn't do "charge" to new cgroup and doesn't do "uncharge"
4484 static int mem_cgroup_move_account(struct page
*page
,
4486 struct mem_cgroup
*from
,
4487 struct mem_cgroup
*to
)
4489 unsigned long flags
;
4490 unsigned int nr_pages
= compound
? hpage_nr_pages(page
) : 1;
4494 VM_BUG_ON(from
== to
);
4495 VM_BUG_ON_PAGE(PageLRU(page
), page
);
4496 VM_BUG_ON(compound
&& !PageTransHuge(page
));
4499 * Prevent mem_cgroup_migrate() from looking at
4500 * page->mem_cgroup of its source page while we change it.
4503 if (!trylock_page(page
))
4507 if (page
->mem_cgroup
!= from
)
4510 anon
= PageAnon(page
);
4512 spin_lock_irqsave(&from
->move_lock
, flags
);
4514 if (!anon
&& page_mapped(page
)) {
4515 __this_cpu_sub(from
->stat
->count
[MEM_CGROUP_STAT_FILE_MAPPED
],
4517 __this_cpu_add(to
->stat
->count
[MEM_CGROUP_STAT_FILE_MAPPED
],
4522 * move_lock grabbed above and caller set from->moving_account, so
4523 * mem_cgroup_update_page_stat() will serialize updates to PageDirty.
4524 * So mapping should be stable for dirty pages.
4526 if (!anon
&& PageDirty(page
)) {
4527 struct address_space
*mapping
= page_mapping(page
);
4529 if (mapping_cap_account_dirty(mapping
)) {
4530 __this_cpu_sub(from
->stat
->count
[MEM_CGROUP_STAT_DIRTY
],
4532 __this_cpu_add(to
->stat
->count
[MEM_CGROUP_STAT_DIRTY
],
4537 if (PageWriteback(page
)) {
4538 __this_cpu_sub(from
->stat
->count
[MEM_CGROUP_STAT_WRITEBACK
],
4540 __this_cpu_add(to
->stat
->count
[MEM_CGROUP_STAT_WRITEBACK
],
4545 * It is safe to change page->mem_cgroup here because the page
4546 * is referenced, charged, and isolated - we can't race with
4547 * uncharging, charging, migration, or LRU putback.
4550 /* caller should have done css_get */
4551 page
->mem_cgroup
= to
;
4552 spin_unlock_irqrestore(&from
->move_lock
, flags
);
4556 local_irq_disable();
4557 mem_cgroup_charge_statistics(to
, page
, compound
, nr_pages
);
4558 memcg_check_events(to
, page
);
4559 mem_cgroup_charge_statistics(from
, page
, compound
, -nr_pages
);
4560 memcg_check_events(from
, page
);
4569 * get_mctgt_type - get target type of moving charge
4570 * @vma: the vma the pte to be checked belongs
4571 * @addr: the address corresponding to the pte to be checked
4572 * @ptent: the pte to be checked
4573 * @target: the pointer the target page or swap ent will be stored(can be NULL)
4576 * 0(MC_TARGET_NONE): if the pte is not a target for move charge.
4577 * 1(MC_TARGET_PAGE): if the page corresponding to this pte is a target for
4578 * move charge. if @target is not NULL, the page is stored in target->page
4579 * with extra refcnt got(Callers should handle it).
4580 * 2(MC_TARGET_SWAP): if the swap entry corresponding to this pte is a
4581 * target for charge migration. if @target is not NULL, the entry is stored
4584 * Called with pte lock held.
4587 static enum mc_target_type
get_mctgt_type(struct vm_area_struct
*vma
,
4588 unsigned long addr
, pte_t ptent
, union mc_target
*target
)
4590 struct page
*page
= NULL
;
4591 enum mc_target_type ret
= MC_TARGET_NONE
;
4592 swp_entry_t ent
= { .val
= 0 };
4594 if (pte_present(ptent
))
4595 page
= mc_handle_present_pte(vma
, addr
, ptent
);
4596 else if (is_swap_pte(ptent
))
4597 page
= mc_handle_swap_pte(vma
, ptent
, &ent
);
4598 else if (pte_none(ptent
))
4599 page
= mc_handle_file_pte(vma
, addr
, ptent
, &ent
);
4601 if (!page
&& !ent
.val
)
4605 * Do only loose check w/o serialization.
4606 * mem_cgroup_move_account() checks the page is valid or
4607 * not under LRU exclusion.
4609 if (page
->mem_cgroup
== mc
.from
) {
4610 ret
= MC_TARGET_PAGE
;
4612 target
->page
= page
;
4614 if (!ret
|| !target
)
4617 /* There is a swap entry and a page doesn't exist or isn't charged */
4618 if (ent
.val
&& !ret
&&
4619 mem_cgroup_id(mc
.from
) == lookup_swap_cgroup_id(ent
)) {
4620 ret
= MC_TARGET_SWAP
;
4627 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
4629 * We don't consider swapping or file mapped pages because THP does not
4630 * support them for now.
4631 * Caller should make sure that pmd_trans_huge(pmd) is true.
4633 static enum mc_target_type
get_mctgt_type_thp(struct vm_area_struct
*vma
,
4634 unsigned long addr
, pmd_t pmd
, union mc_target
*target
)
4636 struct page
*page
= NULL
;
4637 enum mc_target_type ret
= MC_TARGET_NONE
;
4639 page
= pmd_page(pmd
);
4640 VM_BUG_ON_PAGE(!page
|| !PageHead(page
), page
);
4641 if (!(mc
.flags
& MOVE_ANON
))
4643 if (page
->mem_cgroup
== mc
.from
) {
4644 ret
= MC_TARGET_PAGE
;
4647 target
->page
= page
;
4653 static inline enum mc_target_type
get_mctgt_type_thp(struct vm_area_struct
*vma
,
4654 unsigned long addr
, pmd_t pmd
, union mc_target
*target
)
4656 return MC_TARGET_NONE
;
4660 static int mem_cgroup_count_precharge_pte_range(pmd_t
*pmd
,
4661 unsigned long addr
, unsigned long end
,
4662 struct mm_walk
*walk
)
4664 struct vm_area_struct
*vma
= walk
->vma
;
4668 ptl
= pmd_trans_huge_lock(pmd
, vma
);
4670 if (get_mctgt_type_thp(vma
, addr
, *pmd
, NULL
) == MC_TARGET_PAGE
)
4671 mc
.precharge
+= HPAGE_PMD_NR
;
4676 if (pmd_trans_unstable(pmd
))
4678 pte
= pte_offset_map_lock(vma
->vm_mm
, pmd
, addr
, &ptl
);
4679 for (; addr
!= end
; pte
++, addr
+= PAGE_SIZE
)
4680 if (get_mctgt_type(vma
, addr
, *pte
, NULL
))
4681 mc
.precharge
++; /* increment precharge temporarily */
4682 pte_unmap_unlock(pte
- 1, ptl
);
4688 static unsigned long mem_cgroup_count_precharge(struct mm_struct
*mm
)
4690 unsigned long precharge
;
4692 struct mm_walk mem_cgroup_count_precharge_walk
= {
4693 .pmd_entry
= mem_cgroup_count_precharge_pte_range
,
4696 down_read(&mm
->mmap_sem
);
4697 walk_page_range(0, ~0UL, &mem_cgroup_count_precharge_walk
);
4698 up_read(&mm
->mmap_sem
);
4700 precharge
= mc
.precharge
;
4706 static int mem_cgroup_precharge_mc(struct mm_struct
*mm
)
4708 unsigned long precharge
= mem_cgroup_count_precharge(mm
);
4710 VM_BUG_ON(mc
.moving_task
);
4711 mc
.moving_task
= current
;
4712 return mem_cgroup_do_precharge(precharge
);
4715 /* cancels all extra charges on mc.from and mc.to, and wakes up all waiters. */
4716 static void __mem_cgroup_clear_mc(void)
4718 struct mem_cgroup
*from
= mc
.from
;
4719 struct mem_cgroup
*to
= mc
.to
;
4721 /* we must uncharge all the leftover precharges from mc.to */
4723 cancel_charge(mc
.to
, mc
.precharge
);
4727 * we didn't uncharge from mc.from at mem_cgroup_move_account(), so
4728 * we must uncharge here.
4730 if (mc
.moved_charge
) {
4731 cancel_charge(mc
.from
, mc
.moved_charge
);
4732 mc
.moved_charge
= 0;
4734 /* we must fixup refcnts and charges */
4735 if (mc
.moved_swap
) {
4736 /* uncharge swap account from the old cgroup */
4737 if (!mem_cgroup_is_root(mc
.from
))
4738 page_counter_uncharge(&mc
.from
->memsw
, mc
.moved_swap
);
4741 * we charged both to->memory and to->memsw, so we
4742 * should uncharge to->memory.
4744 if (!mem_cgroup_is_root(mc
.to
))
4745 page_counter_uncharge(&mc
.to
->memory
, mc
.moved_swap
);
4747 css_put_many(&mc
.from
->css
, mc
.moved_swap
);
4749 /* we've already done css_get(mc.to) */
4752 memcg_oom_recover(from
);
4753 memcg_oom_recover(to
);
4754 wake_up_all(&mc
.waitq
);
4757 static void mem_cgroup_clear_mc(void)
4759 struct mm_struct
*mm
= mc
.mm
;
4762 * we must clear moving_task before waking up waiters at the end of
4765 mc
.moving_task
= NULL
;
4766 __mem_cgroup_clear_mc();
4767 spin_lock(&mc
.lock
);
4771 spin_unlock(&mc
.lock
);
4776 static int mem_cgroup_can_attach(struct cgroup_taskset
*tset
)
4778 struct cgroup_subsys_state
*css
;
4779 struct mem_cgroup
*memcg
= NULL
; /* unneeded init to make gcc happy */
4780 struct mem_cgroup
*from
;
4781 struct task_struct
*leader
, *p
;
4782 struct mm_struct
*mm
;
4783 unsigned long move_flags
;
4786 /* charge immigration isn't supported on the default hierarchy */
4787 if (cgroup_subsys_on_dfl(memory_cgrp_subsys
))
4791 * Multi-process migrations only happen on the default hierarchy
4792 * where charge immigration is not used. Perform charge
4793 * immigration if @tset contains a leader and whine if there are
4797 cgroup_taskset_for_each_leader(leader
, css
, tset
) {
4800 memcg
= mem_cgroup_from_css(css
);
4806 * We are now commited to this value whatever it is. Changes in this
4807 * tunable will only affect upcoming migrations, not the current one.
4808 * So we need to save it, and keep it going.
4810 move_flags
= READ_ONCE(memcg
->move_charge_at_immigrate
);
4814 from
= mem_cgroup_from_task(p
);
4816 VM_BUG_ON(from
== memcg
);
4818 mm
= get_task_mm(p
);
4821 /* We move charges only when we move a owner of the mm */
4822 if (mm
->owner
== p
) {
4825 VM_BUG_ON(mc
.precharge
);
4826 VM_BUG_ON(mc
.moved_charge
);
4827 VM_BUG_ON(mc
.moved_swap
);
4829 spin_lock(&mc
.lock
);
4833 mc
.flags
= move_flags
;
4834 spin_unlock(&mc
.lock
);
4835 /* We set mc.moving_task later */
4837 ret
= mem_cgroup_precharge_mc(mm
);
4839 mem_cgroup_clear_mc();
4846 static void mem_cgroup_cancel_attach(struct cgroup_taskset
*tset
)
4849 mem_cgroup_clear_mc();
4852 static int mem_cgroup_move_charge_pte_range(pmd_t
*pmd
,
4853 unsigned long addr
, unsigned long end
,
4854 struct mm_walk
*walk
)
4857 struct vm_area_struct
*vma
= walk
->vma
;
4860 enum mc_target_type target_type
;
4861 union mc_target target
;
4864 ptl
= pmd_trans_huge_lock(pmd
, vma
);
4866 if (mc
.precharge
< HPAGE_PMD_NR
) {
4870 target_type
= get_mctgt_type_thp(vma
, addr
, *pmd
, &target
);
4871 if (target_type
== MC_TARGET_PAGE
) {
4873 if (!isolate_lru_page(page
)) {
4874 if (!mem_cgroup_move_account(page
, true,
4876 mc
.precharge
-= HPAGE_PMD_NR
;
4877 mc
.moved_charge
+= HPAGE_PMD_NR
;
4879 putback_lru_page(page
);
4887 if (pmd_trans_unstable(pmd
))
4890 pte
= pte_offset_map_lock(vma
->vm_mm
, pmd
, addr
, &ptl
);
4891 for (; addr
!= end
; addr
+= PAGE_SIZE
) {
4892 pte_t ptent
= *(pte
++);
4898 switch (get_mctgt_type(vma
, addr
, ptent
, &target
)) {
4899 case MC_TARGET_PAGE
:
4902 * We can have a part of the split pmd here. Moving it
4903 * can be done but it would be too convoluted so simply
4904 * ignore such a partial THP and keep it in original
4905 * memcg. There should be somebody mapping the head.
4907 if (PageTransCompound(page
))
4909 if (isolate_lru_page(page
))
4911 if (!mem_cgroup_move_account(page
, false,
4914 /* we uncharge from mc.from later. */
4917 putback_lru_page(page
);
4918 put
: /* get_mctgt_type() gets the page */
4921 case MC_TARGET_SWAP
:
4923 if (!mem_cgroup_move_swap_account(ent
, mc
.from
, mc
.to
)) {
4925 /* we fixup refcnts and charges later. */
4933 pte_unmap_unlock(pte
- 1, ptl
);
4938 * We have consumed all precharges we got in can_attach().
4939 * We try charge one by one, but don't do any additional
4940 * charges to mc.to if we have failed in charge once in attach()
4943 ret
= mem_cgroup_do_precharge(1);
4951 static void mem_cgroup_move_charge(void)
4953 struct mm_walk mem_cgroup_move_charge_walk
= {
4954 .pmd_entry
= mem_cgroup_move_charge_pte_range
,
4958 lru_add_drain_all();
4960 * Signal lock_page_memcg() to take the memcg's move_lock
4961 * while we're moving its pages to another memcg. Then wait
4962 * for already started RCU-only updates to finish.
4964 atomic_inc(&mc
.from
->moving_account
);
4967 if (unlikely(!down_read_trylock(&mc
.mm
->mmap_sem
))) {
4969 * Someone who are holding the mmap_sem might be waiting in
4970 * waitq. So we cancel all extra charges, wake up all waiters,
4971 * and retry. Because we cancel precharges, we might not be able
4972 * to move enough charges, but moving charge is a best-effort
4973 * feature anyway, so it wouldn't be a big problem.
4975 __mem_cgroup_clear_mc();
4980 * When we have consumed all precharges and failed in doing
4981 * additional charge, the page walk just aborts.
4983 walk_page_range(0, ~0UL, &mem_cgroup_move_charge_walk
);
4984 up_read(&mc
.mm
->mmap_sem
);
4985 atomic_dec(&mc
.from
->moving_account
);
4988 static void mem_cgroup_move_task(void)
4991 mem_cgroup_move_charge();
4992 mem_cgroup_clear_mc();
4995 #else /* !CONFIG_MMU */
4996 static int mem_cgroup_can_attach(struct cgroup_taskset
*tset
)
5000 static void mem_cgroup_cancel_attach(struct cgroup_taskset
*tset
)
5003 static void mem_cgroup_move_task(void)
5009 * Cgroup retains root cgroups across [un]mount cycles making it necessary
5010 * to verify whether we're attached to the default hierarchy on each mount
5013 static void mem_cgroup_bind(struct cgroup_subsys_state
*root_css
)
5016 * use_hierarchy is forced on the default hierarchy. cgroup core
5017 * guarantees that @root doesn't have any children, so turning it
5018 * on for the root memcg is enough.
5020 if (cgroup_subsys_on_dfl(memory_cgrp_subsys
))
5021 root_mem_cgroup
->use_hierarchy
= true;
5023 root_mem_cgroup
->use_hierarchy
= false;
5026 static u64
memory_current_read(struct cgroup_subsys_state
*css
,
5029 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
5031 return (u64
)page_counter_read(&memcg
->memory
) * PAGE_SIZE
;
5034 static int memory_low_show(struct seq_file
*m
, void *v
)
5036 struct mem_cgroup
*memcg
= mem_cgroup_from_css(seq_css(m
));
5037 unsigned long low
= READ_ONCE(memcg
->low
);
5039 if (low
== PAGE_COUNTER_MAX
)
5040 seq_puts(m
, "max\n");
5042 seq_printf(m
, "%llu\n", (u64
)low
* PAGE_SIZE
);
5047 static ssize_t
memory_low_write(struct kernfs_open_file
*of
,
5048 char *buf
, size_t nbytes
, loff_t off
)
5050 struct mem_cgroup
*memcg
= mem_cgroup_from_css(of_css(of
));
5054 buf
= strstrip(buf
);
5055 err
= page_counter_memparse(buf
, "max", &low
);
5064 static int memory_high_show(struct seq_file
*m
, void *v
)
5066 struct mem_cgroup
*memcg
= mem_cgroup_from_css(seq_css(m
));
5067 unsigned long high
= READ_ONCE(memcg
->high
);
5069 if (high
== PAGE_COUNTER_MAX
)
5070 seq_puts(m
, "max\n");
5072 seq_printf(m
, "%llu\n", (u64
)high
* PAGE_SIZE
);
5077 static ssize_t
memory_high_write(struct kernfs_open_file
*of
,
5078 char *buf
, size_t nbytes
, loff_t off
)
5080 struct mem_cgroup
*memcg
= mem_cgroup_from_css(of_css(of
));
5081 unsigned long nr_pages
;
5085 buf
= strstrip(buf
);
5086 err
= page_counter_memparse(buf
, "max", &high
);
5092 nr_pages
= page_counter_read(&memcg
->memory
);
5093 if (nr_pages
> high
)
5094 try_to_free_mem_cgroup_pages(memcg
, nr_pages
- high
,
5097 memcg_wb_domain_size_changed(memcg
);
5101 static int memory_max_show(struct seq_file
*m
, void *v
)
5103 struct mem_cgroup
*memcg
= mem_cgroup_from_css(seq_css(m
));
5104 unsigned long max
= READ_ONCE(memcg
->memory
.limit
);
5106 if (max
== PAGE_COUNTER_MAX
)
5107 seq_puts(m
, "max\n");
5109 seq_printf(m
, "%llu\n", (u64
)max
* PAGE_SIZE
);
5114 static ssize_t
memory_max_write(struct kernfs_open_file
*of
,
5115 char *buf
, size_t nbytes
, loff_t off
)
5117 struct mem_cgroup
*memcg
= mem_cgroup_from_css(of_css(of
));
5118 unsigned int nr_reclaims
= MEM_CGROUP_RECLAIM_RETRIES
;
5119 bool drained
= false;
5123 buf
= strstrip(buf
);
5124 err
= page_counter_memparse(buf
, "max", &max
);
5128 xchg(&memcg
->memory
.limit
, max
);
5131 unsigned long nr_pages
= page_counter_read(&memcg
->memory
);
5133 if (nr_pages
<= max
)
5136 if (signal_pending(current
)) {
5142 drain_all_stock(memcg
);
5148 if (!try_to_free_mem_cgroup_pages(memcg
, nr_pages
- max
,
5154 mem_cgroup_events(memcg
, MEMCG_OOM
, 1);
5155 if (!mem_cgroup_out_of_memory(memcg
, GFP_KERNEL
, 0))
5159 memcg_wb_domain_size_changed(memcg
);
5163 static int memory_events_show(struct seq_file
*m
, void *v
)
5165 struct mem_cgroup
*memcg
= mem_cgroup_from_css(seq_css(m
));
5167 seq_printf(m
, "low %lu\n", mem_cgroup_read_events(memcg
, MEMCG_LOW
));
5168 seq_printf(m
, "high %lu\n", mem_cgroup_read_events(memcg
, MEMCG_HIGH
));
5169 seq_printf(m
, "max %lu\n", mem_cgroup_read_events(memcg
, MEMCG_MAX
));
5170 seq_printf(m
, "oom %lu\n", mem_cgroup_read_events(memcg
, MEMCG_OOM
));
5175 static int memory_stat_show(struct seq_file
*m
, void *v
)
5177 struct mem_cgroup
*memcg
= mem_cgroup_from_css(seq_css(m
));
5178 unsigned long stat
[MEMCG_NR_STAT
];
5179 unsigned long events
[MEMCG_NR_EVENTS
];
5183 * Provide statistics on the state of the memory subsystem as
5184 * well as cumulative event counters that show past behavior.
5186 * This list is ordered following a combination of these gradients:
5187 * 1) generic big picture -> specifics and details
5188 * 2) reflecting userspace activity -> reflecting kernel heuristics
5190 * Current memory state:
5193 tree_stat(memcg
, stat
);
5194 tree_events(memcg
, events
);
5196 seq_printf(m
, "anon %llu\n",
5197 (u64
)stat
[MEM_CGROUP_STAT_RSS
] * PAGE_SIZE
);
5198 seq_printf(m
, "file %llu\n",
5199 (u64
)stat
[MEM_CGROUP_STAT_CACHE
] * PAGE_SIZE
);
5200 seq_printf(m
, "kernel_stack %llu\n",
5201 (u64
)stat
[MEMCG_KERNEL_STACK
] * PAGE_SIZE
);
5202 seq_printf(m
, "slab %llu\n",
5203 (u64
)(stat
[MEMCG_SLAB_RECLAIMABLE
] +
5204 stat
[MEMCG_SLAB_UNRECLAIMABLE
]) * PAGE_SIZE
);
5205 seq_printf(m
, "sock %llu\n",
5206 (u64
)stat
[MEMCG_SOCK
] * PAGE_SIZE
);
5208 seq_printf(m
, "file_mapped %llu\n",
5209 (u64
)stat
[MEM_CGROUP_STAT_FILE_MAPPED
] * PAGE_SIZE
);
5210 seq_printf(m
, "file_dirty %llu\n",
5211 (u64
)stat
[MEM_CGROUP_STAT_DIRTY
] * PAGE_SIZE
);
5212 seq_printf(m
, "file_writeback %llu\n",
5213 (u64
)stat
[MEM_CGROUP_STAT_WRITEBACK
] * PAGE_SIZE
);
5215 for (i
= 0; i
< NR_LRU_LISTS
; i
++) {
5216 struct mem_cgroup
*mi
;
5217 unsigned long val
= 0;
5219 for_each_mem_cgroup_tree(mi
, memcg
)
5220 val
+= mem_cgroup_nr_lru_pages(mi
, BIT(i
));
5221 seq_printf(m
, "%s %llu\n",
5222 mem_cgroup_lru_names
[i
], (u64
)val
* PAGE_SIZE
);
5225 seq_printf(m
, "slab_reclaimable %llu\n",
5226 (u64
)stat
[MEMCG_SLAB_RECLAIMABLE
] * PAGE_SIZE
);
5227 seq_printf(m
, "slab_unreclaimable %llu\n",
5228 (u64
)stat
[MEMCG_SLAB_UNRECLAIMABLE
] * PAGE_SIZE
);
5230 /* Accumulated memory events */
5232 seq_printf(m
, "pgfault %lu\n",
5233 events
[MEM_CGROUP_EVENTS_PGFAULT
]);
5234 seq_printf(m
, "pgmajfault %lu\n",
5235 events
[MEM_CGROUP_EVENTS_PGMAJFAULT
]);
5240 static struct cftype memory_files
[] = {
5243 .flags
= CFTYPE_NOT_ON_ROOT
,
5244 .read_u64
= memory_current_read
,
5248 .flags
= CFTYPE_NOT_ON_ROOT
,
5249 .seq_show
= memory_low_show
,
5250 .write
= memory_low_write
,
5254 .flags
= CFTYPE_NOT_ON_ROOT
,
5255 .seq_show
= memory_high_show
,
5256 .write
= memory_high_write
,
5260 .flags
= CFTYPE_NOT_ON_ROOT
,
5261 .seq_show
= memory_max_show
,
5262 .write
= memory_max_write
,
5266 .flags
= CFTYPE_NOT_ON_ROOT
,
5267 .file_offset
= offsetof(struct mem_cgroup
, events_file
),
5268 .seq_show
= memory_events_show
,
5272 .flags
= CFTYPE_NOT_ON_ROOT
,
5273 .seq_show
= memory_stat_show
,
5278 struct cgroup_subsys memory_cgrp_subsys
= {
5279 .css_alloc
= mem_cgroup_css_alloc
,
5280 .css_online
= mem_cgroup_css_online
,
5281 .css_offline
= mem_cgroup_css_offline
,
5282 .css_released
= mem_cgroup_css_released
,
5283 .css_free
= mem_cgroup_css_free
,
5284 .css_reset
= mem_cgroup_css_reset
,
5285 .can_attach
= mem_cgroup_can_attach
,
5286 .cancel_attach
= mem_cgroup_cancel_attach
,
5287 .post_attach
= mem_cgroup_move_task
,
5288 .bind
= mem_cgroup_bind
,
5289 .dfl_cftypes
= memory_files
,
5290 .legacy_cftypes
= mem_cgroup_legacy_files
,
5295 * mem_cgroup_low - check if memory consumption is below the normal range
5296 * @root: the highest ancestor to consider
5297 * @memcg: the memory cgroup to check
5299 * Returns %true if memory consumption of @memcg, and that of all
5300 * configurable ancestors up to @root, is below the normal range.
5302 bool mem_cgroup_low(struct mem_cgroup
*root
, struct mem_cgroup
*memcg
)
5304 if (mem_cgroup_disabled())
5308 * The toplevel group doesn't have a configurable range, so
5309 * it's never low when looked at directly, and it is not
5310 * considered an ancestor when assessing the hierarchy.
5313 if (memcg
== root_mem_cgroup
)
5316 if (page_counter_read(&memcg
->memory
) >= memcg
->low
)
5319 while (memcg
!= root
) {
5320 memcg
= parent_mem_cgroup(memcg
);
5322 if (memcg
== root_mem_cgroup
)
5325 if (page_counter_read(&memcg
->memory
) >= memcg
->low
)
5332 * mem_cgroup_try_charge - try charging a page
5333 * @page: page to charge
5334 * @mm: mm context of the victim
5335 * @gfp_mask: reclaim mode
5336 * @memcgp: charged memcg return
5338 * Try to charge @page to the memcg that @mm belongs to, reclaiming
5339 * pages according to @gfp_mask if necessary.
5341 * Returns 0 on success, with *@memcgp pointing to the charged memcg.
5342 * Otherwise, an error code is returned.
5344 * After page->mapping has been set up, the caller must finalize the
5345 * charge with mem_cgroup_commit_charge(). Or abort the transaction
5346 * with mem_cgroup_cancel_charge() in case page instantiation fails.
5348 int mem_cgroup_try_charge(struct page
*page
, struct mm_struct
*mm
,
5349 gfp_t gfp_mask
, struct mem_cgroup
**memcgp
,
5352 struct mem_cgroup
*memcg
= NULL
;
5353 unsigned int nr_pages
= compound
? hpage_nr_pages(page
) : 1;
5356 if (mem_cgroup_disabled())
5359 if (PageSwapCache(page
)) {
5361 * Every swap fault against a single page tries to charge the
5362 * page, bail as early as possible. shmem_unuse() encounters
5363 * already charged pages, too. The USED bit is protected by
5364 * the page lock, which serializes swap cache removal, which
5365 * in turn serializes uncharging.
5367 VM_BUG_ON_PAGE(!PageLocked(page
), page
);
5368 if (page
->mem_cgroup
)
5371 if (do_swap_account
) {
5372 swp_entry_t ent
= { .val
= page_private(page
), };
5373 unsigned short id
= lookup_swap_cgroup_id(ent
);
5376 memcg
= mem_cgroup_from_id(id
);
5377 if (memcg
&& !css_tryget_online(&memcg
->css
))
5384 memcg
= get_mem_cgroup_from_mm(mm
);
5386 ret
= try_charge(memcg
, gfp_mask
, nr_pages
);
5388 css_put(&memcg
->css
);
5395 * mem_cgroup_commit_charge - commit a page charge
5396 * @page: page to charge
5397 * @memcg: memcg to charge the page to
5398 * @lrucare: page might be on LRU already
5400 * Finalize a charge transaction started by mem_cgroup_try_charge(),
5401 * after page->mapping has been set up. This must happen atomically
5402 * as part of the page instantiation, i.e. under the page table lock
5403 * for anonymous pages, under the page lock for page and swap cache.
5405 * In addition, the page must not be on the LRU during the commit, to
5406 * prevent racing with task migration. If it might be, use @lrucare.
5408 * Use mem_cgroup_cancel_charge() to cancel the transaction instead.
5410 void mem_cgroup_commit_charge(struct page
*page
, struct mem_cgroup
*memcg
,
5411 bool lrucare
, bool compound
)
5413 unsigned int nr_pages
= compound
? hpage_nr_pages(page
) : 1;
5415 VM_BUG_ON_PAGE(!page
->mapping
, page
);
5416 VM_BUG_ON_PAGE(PageLRU(page
) && !lrucare
, page
);
5418 if (mem_cgroup_disabled())
5421 * Swap faults will attempt to charge the same page multiple
5422 * times. But reuse_swap_page() might have removed the page
5423 * from swapcache already, so we can't check PageSwapCache().
5428 commit_charge(page
, memcg
, lrucare
);
5430 local_irq_disable();
5431 mem_cgroup_charge_statistics(memcg
, page
, compound
, nr_pages
);
5432 memcg_check_events(memcg
, page
);
5435 if (do_memsw_account() && PageSwapCache(page
)) {
5436 swp_entry_t entry
= { .val
= page_private(page
) };
5438 * The swap entry might not get freed for a long time,
5439 * let's not wait for it. The page already received a
5440 * memory+swap charge, drop the swap entry duplicate.
5442 mem_cgroup_uncharge_swap(entry
);
5447 * mem_cgroup_cancel_charge - cancel a page charge
5448 * @page: page to charge
5449 * @memcg: memcg to charge the page to
5451 * Cancel a charge transaction started by mem_cgroup_try_charge().
5453 void mem_cgroup_cancel_charge(struct page
*page
, struct mem_cgroup
*memcg
,
5456 unsigned int nr_pages
= compound
? hpage_nr_pages(page
) : 1;
5458 if (mem_cgroup_disabled())
5461 * Swap faults will attempt to charge the same page multiple
5462 * times. But reuse_swap_page() might have removed the page
5463 * from swapcache already, so we can't check PageSwapCache().
5468 cancel_charge(memcg
, nr_pages
);
5471 static void uncharge_batch(struct mem_cgroup
*memcg
, unsigned long pgpgout
,
5472 unsigned long nr_anon
, unsigned long nr_file
,
5473 unsigned long nr_huge
, struct page
*dummy_page
)
5475 unsigned long nr_pages
= nr_anon
+ nr_file
;
5476 unsigned long flags
;
5478 if (!mem_cgroup_is_root(memcg
)) {
5479 page_counter_uncharge(&memcg
->memory
, nr_pages
);
5480 if (do_memsw_account())
5481 page_counter_uncharge(&memcg
->memsw
, nr_pages
);
5482 memcg_oom_recover(memcg
);
5485 local_irq_save(flags
);
5486 __this_cpu_sub(memcg
->stat
->count
[MEM_CGROUP_STAT_RSS
], nr_anon
);
5487 __this_cpu_sub(memcg
->stat
->count
[MEM_CGROUP_STAT_CACHE
], nr_file
);
5488 __this_cpu_sub(memcg
->stat
->count
[MEM_CGROUP_STAT_RSS_HUGE
], nr_huge
);
5489 __this_cpu_add(memcg
->stat
->events
[MEM_CGROUP_EVENTS_PGPGOUT
], pgpgout
);
5490 __this_cpu_add(memcg
->stat
->nr_page_events
, nr_pages
);
5491 memcg_check_events(memcg
, dummy_page
);
5492 local_irq_restore(flags
);
5494 if (!mem_cgroup_is_root(memcg
))
5495 css_put_many(&memcg
->css
, nr_pages
);
5498 static void uncharge_list(struct list_head
*page_list
)
5500 struct mem_cgroup
*memcg
= NULL
;
5501 unsigned long nr_anon
= 0;
5502 unsigned long nr_file
= 0;
5503 unsigned long nr_huge
= 0;
5504 unsigned long pgpgout
= 0;
5505 struct list_head
*next
;
5509 * Note that the list can be a single page->lru; hence the
5510 * do-while loop instead of a simple list_for_each_entry().
5512 next
= page_list
->next
;
5514 unsigned int nr_pages
= 1;
5516 page
= list_entry(next
, struct page
, lru
);
5517 next
= page
->lru
.next
;
5519 VM_BUG_ON_PAGE(PageLRU(page
), page
);
5520 VM_BUG_ON_PAGE(page_count(page
), page
);
5522 if (!page
->mem_cgroup
)
5526 * Nobody should be changing or seriously looking at
5527 * page->mem_cgroup at this point, we have fully
5528 * exclusive access to the page.
5531 if (memcg
!= page
->mem_cgroup
) {
5533 uncharge_batch(memcg
, pgpgout
, nr_anon
, nr_file
,
5535 pgpgout
= nr_anon
= nr_file
= nr_huge
= 0;
5537 memcg
= page
->mem_cgroup
;
5540 if (PageTransHuge(page
)) {
5541 nr_pages
<<= compound_order(page
);
5542 VM_BUG_ON_PAGE(!PageTransHuge(page
), page
);
5543 nr_huge
+= nr_pages
;
5547 nr_anon
+= nr_pages
;
5549 nr_file
+= nr_pages
;
5551 page
->mem_cgroup
= NULL
;
5554 } while (next
!= page_list
);
5557 uncharge_batch(memcg
, pgpgout
, nr_anon
, nr_file
,
5562 * mem_cgroup_uncharge - uncharge a page
5563 * @page: page to uncharge
5565 * Uncharge a page previously charged with mem_cgroup_try_charge() and
5566 * mem_cgroup_commit_charge().
5568 void mem_cgroup_uncharge(struct page
*page
)
5570 if (mem_cgroup_disabled())
5573 /* Don't touch page->lru of any random page, pre-check: */
5574 if (!page
->mem_cgroup
)
5577 INIT_LIST_HEAD(&page
->lru
);
5578 uncharge_list(&page
->lru
);
5582 * mem_cgroup_uncharge_list - uncharge a list of page
5583 * @page_list: list of pages to uncharge
5585 * Uncharge a list of pages previously charged with
5586 * mem_cgroup_try_charge() and mem_cgroup_commit_charge().
5588 void mem_cgroup_uncharge_list(struct list_head
*page_list
)
5590 if (mem_cgroup_disabled())
5593 if (!list_empty(page_list
))
5594 uncharge_list(page_list
);
5598 * mem_cgroup_migrate - charge a page's replacement
5599 * @oldpage: currently circulating page
5600 * @newpage: replacement page
5602 * Charge @newpage as a replacement page for @oldpage. @oldpage will
5603 * be uncharged upon free.
5605 * Both pages must be locked, @newpage->mapping must be set up.
5607 void mem_cgroup_migrate(struct page
*oldpage
, struct page
*newpage
)
5609 struct mem_cgroup
*memcg
;
5610 unsigned int nr_pages
;
5612 unsigned long flags
;
5614 VM_BUG_ON_PAGE(!PageLocked(oldpage
), oldpage
);
5615 VM_BUG_ON_PAGE(!PageLocked(newpage
), newpage
);
5616 VM_BUG_ON_PAGE(PageAnon(oldpage
) != PageAnon(newpage
), newpage
);
5617 VM_BUG_ON_PAGE(PageTransHuge(oldpage
) != PageTransHuge(newpage
),
5620 if (mem_cgroup_disabled())
5623 /* Page cache replacement: new page already charged? */
5624 if (newpage
->mem_cgroup
)
5627 /* Swapcache readahead pages can get replaced before being charged */
5628 memcg
= oldpage
->mem_cgroup
;
5632 /* Force-charge the new page. The old one will be freed soon */
5633 compound
= PageTransHuge(newpage
);
5634 nr_pages
= compound
? hpage_nr_pages(newpage
) : 1;
5636 page_counter_charge(&memcg
->memory
, nr_pages
);
5637 if (do_memsw_account())
5638 page_counter_charge(&memcg
->memsw
, nr_pages
);
5639 css_get_many(&memcg
->css
, nr_pages
);
5641 commit_charge(newpage
, memcg
, false);
5643 local_irq_save(flags
);
5644 mem_cgroup_charge_statistics(memcg
, newpage
, compound
, nr_pages
);
5645 memcg_check_events(memcg
, newpage
);
5646 local_irq_restore(flags
);
5649 DEFINE_STATIC_KEY_FALSE(memcg_sockets_enabled_key
);
5650 EXPORT_SYMBOL(memcg_sockets_enabled_key
);
5652 void sock_update_memcg(struct sock
*sk
)
5654 struct mem_cgroup
*memcg
;
5656 /* Socket cloning can throw us here with sk_cgrp already
5657 * filled. It won't however, necessarily happen from
5658 * process context. So the test for root memcg given
5659 * the current task's memcg won't help us in this case.
5661 * Respecting the original socket's memcg is a better
5662 * decision in this case.
5665 BUG_ON(mem_cgroup_is_root(sk
->sk_memcg
));
5666 css_get(&sk
->sk_memcg
->css
);
5671 memcg
= mem_cgroup_from_task(current
);
5672 if (memcg
== root_mem_cgroup
)
5674 if (!cgroup_subsys_on_dfl(memory_cgrp_subsys
) && !memcg
->tcpmem_active
)
5676 if (css_tryget_online(&memcg
->css
))
5677 sk
->sk_memcg
= memcg
;
5681 EXPORT_SYMBOL(sock_update_memcg
);
5683 void sock_release_memcg(struct sock
*sk
)
5685 WARN_ON(!sk
->sk_memcg
);
5686 css_put(&sk
->sk_memcg
->css
);
5690 * mem_cgroup_charge_skmem - charge socket memory
5691 * @memcg: memcg to charge
5692 * @nr_pages: number of pages to charge
5694 * Charges @nr_pages to @memcg. Returns %true if the charge fit within
5695 * @memcg's configured limit, %false if the charge had to be forced.
5697 bool mem_cgroup_charge_skmem(struct mem_cgroup
*memcg
, unsigned int nr_pages
)
5699 gfp_t gfp_mask
= GFP_KERNEL
;
5701 if (!cgroup_subsys_on_dfl(memory_cgrp_subsys
)) {
5702 struct page_counter
*fail
;
5704 if (page_counter_try_charge(&memcg
->tcpmem
, nr_pages
, &fail
)) {
5705 memcg
->tcpmem_pressure
= 0;
5708 page_counter_charge(&memcg
->tcpmem
, nr_pages
);
5709 memcg
->tcpmem_pressure
= 1;
5713 /* Don't block in the packet receive path */
5715 gfp_mask
= GFP_NOWAIT
;
5717 this_cpu_add(memcg
->stat
->count
[MEMCG_SOCK
], nr_pages
);
5719 if (try_charge(memcg
, gfp_mask
, nr_pages
) == 0)
5722 try_charge(memcg
, gfp_mask
|__GFP_NOFAIL
, nr_pages
);
5727 * mem_cgroup_uncharge_skmem - uncharge socket memory
5728 * @memcg - memcg to uncharge
5729 * @nr_pages - number of pages to uncharge
5731 void mem_cgroup_uncharge_skmem(struct mem_cgroup
*memcg
, unsigned int nr_pages
)
5733 if (!cgroup_subsys_on_dfl(memory_cgrp_subsys
)) {
5734 page_counter_uncharge(&memcg
->tcpmem
, nr_pages
);
5738 this_cpu_sub(memcg
->stat
->count
[MEMCG_SOCK
], nr_pages
);
5740 page_counter_uncharge(&memcg
->memory
, nr_pages
);
5741 css_put_many(&memcg
->css
, nr_pages
);
5744 static int __init
cgroup_memory(char *s
)
5748 while ((token
= strsep(&s
, ",")) != NULL
) {
5751 if (!strcmp(token
, "nosocket"))
5752 cgroup_memory_nosocket
= true;
5753 if (!strcmp(token
, "nokmem"))
5754 cgroup_memory_nokmem
= true;
5758 __setup("cgroup.memory=", cgroup_memory
);
5761 * subsys_initcall() for memory controller.
5763 * Some parts like hotcpu_notifier() have to be initialized from this context
5764 * because of lock dependencies (cgroup_lock -> cpu hotplug) but basically
5765 * everything that doesn't depend on a specific mem_cgroup structure should
5766 * be initialized from here.
5768 static int __init
mem_cgroup_init(void)
5772 hotcpu_notifier(memcg_cpu_hotplug_callback
, 0);
5774 for_each_possible_cpu(cpu
)
5775 INIT_WORK(&per_cpu_ptr(&memcg_stock
, cpu
)->work
,
5778 for_each_node(node
) {
5779 struct mem_cgroup_tree_per_node
*rtpn
;
5782 rtpn
= kzalloc_node(sizeof(*rtpn
), GFP_KERNEL
,
5783 node_online(node
) ? node
: NUMA_NO_NODE
);
5785 for (zone
= 0; zone
< MAX_NR_ZONES
; zone
++) {
5786 struct mem_cgroup_tree_per_zone
*rtpz
;
5788 rtpz
= &rtpn
->rb_tree_per_zone
[zone
];
5789 rtpz
->rb_root
= RB_ROOT
;
5790 spin_lock_init(&rtpz
->lock
);
5792 soft_limit_tree
.rb_tree_per_node
[node
] = rtpn
;
5797 subsys_initcall(mem_cgroup_init
);
5799 #ifdef CONFIG_MEMCG_SWAP
5801 * mem_cgroup_swapout - transfer a memsw charge to swap
5802 * @page: page whose memsw charge to transfer
5803 * @entry: swap entry to move the charge to
5805 * Transfer the memsw charge of @page to @entry.
5807 void mem_cgroup_swapout(struct page
*page
, swp_entry_t entry
)
5809 struct mem_cgroup
*memcg
;
5810 unsigned short oldid
;
5812 VM_BUG_ON_PAGE(PageLRU(page
), page
);
5813 VM_BUG_ON_PAGE(page_count(page
), page
);
5815 if (!do_memsw_account())
5818 memcg
= page
->mem_cgroup
;
5820 /* Readahead page, never charged */
5824 mem_cgroup_id_get(memcg
);
5825 oldid
= swap_cgroup_record(entry
, mem_cgroup_id(memcg
));
5826 VM_BUG_ON_PAGE(oldid
, page
);
5827 mem_cgroup_swap_statistics(memcg
, true);
5829 page
->mem_cgroup
= NULL
;
5831 if (!mem_cgroup_is_root(memcg
))
5832 page_counter_uncharge(&memcg
->memory
, 1);
5835 * Interrupts should be disabled here because the caller holds the
5836 * mapping->tree_lock lock which is taken with interrupts-off. It is
5837 * important here to have the interrupts disabled because it is the
5838 * only synchronisation we have for udpating the per-CPU variables.
5840 VM_BUG_ON(!irqs_disabled());
5841 mem_cgroup_charge_statistics(memcg
, page
, false, -1);
5842 memcg_check_events(memcg
, page
);
5844 if (!mem_cgroup_is_root(memcg
))
5845 css_put(&memcg
->css
);
5849 * mem_cgroup_try_charge_swap - try charging a swap entry
5850 * @page: page being added to swap
5851 * @entry: swap entry to charge
5853 * Try to charge @entry to the memcg that @page belongs to.
5855 * Returns 0 on success, -ENOMEM on failure.
5857 int mem_cgroup_try_charge_swap(struct page
*page
, swp_entry_t entry
)
5859 struct mem_cgroup
*memcg
;
5860 struct page_counter
*counter
;
5861 unsigned short oldid
;
5863 if (!cgroup_subsys_on_dfl(memory_cgrp_subsys
) || !do_swap_account
)
5866 memcg
= page
->mem_cgroup
;
5868 /* Readahead page, never charged */
5872 if (!mem_cgroup_is_root(memcg
) &&
5873 !page_counter_try_charge(&memcg
->swap
, 1, &counter
))
5876 mem_cgroup_id_get(memcg
);
5877 oldid
= swap_cgroup_record(entry
, mem_cgroup_id(memcg
));
5878 VM_BUG_ON_PAGE(oldid
, page
);
5879 mem_cgroup_swap_statistics(memcg
, true);
5885 * mem_cgroup_uncharge_swap - uncharge a swap entry
5886 * @entry: swap entry to uncharge
5888 * Drop the swap charge associated with @entry.
5890 void mem_cgroup_uncharge_swap(swp_entry_t entry
)
5892 struct mem_cgroup
*memcg
;
5895 if (!do_swap_account
)
5898 id
= swap_cgroup_record(entry
, 0);
5900 memcg
= mem_cgroup_from_id(id
);
5902 if (!mem_cgroup_is_root(memcg
)) {
5903 if (cgroup_subsys_on_dfl(memory_cgrp_subsys
))
5904 page_counter_uncharge(&memcg
->swap
, 1);
5906 page_counter_uncharge(&memcg
->memsw
, 1);
5908 mem_cgroup_swap_statistics(memcg
, false);
5909 mem_cgroup_id_put(memcg
);
5914 long mem_cgroup_get_nr_swap_pages(struct mem_cgroup
*memcg
)
5916 long nr_swap_pages
= get_nr_swap_pages();
5918 if (!do_swap_account
|| !cgroup_subsys_on_dfl(memory_cgrp_subsys
))
5919 return nr_swap_pages
;
5920 for (; memcg
!= root_mem_cgroup
; memcg
= parent_mem_cgroup(memcg
))
5921 nr_swap_pages
= min_t(long, nr_swap_pages
,
5922 READ_ONCE(memcg
->swap
.limit
) -
5923 page_counter_read(&memcg
->swap
));
5924 return nr_swap_pages
;
5927 bool mem_cgroup_swap_full(struct page
*page
)
5929 struct mem_cgroup
*memcg
;
5931 VM_BUG_ON_PAGE(!PageLocked(page
), page
);
5935 if (!do_swap_account
|| !cgroup_subsys_on_dfl(memory_cgrp_subsys
))
5938 memcg
= page
->mem_cgroup
;
5942 for (; memcg
!= root_mem_cgroup
; memcg
= parent_mem_cgroup(memcg
))
5943 if (page_counter_read(&memcg
->swap
) * 2 >= memcg
->swap
.limit
)
5949 /* for remember boot option*/
5950 #ifdef CONFIG_MEMCG_SWAP_ENABLED
5951 static int really_do_swap_account __initdata
= 1;
5953 static int really_do_swap_account __initdata
;
5956 static int __init
enable_swap_account(char *s
)
5958 if (!strcmp(s
, "1"))
5959 really_do_swap_account
= 1;
5960 else if (!strcmp(s
, "0"))
5961 really_do_swap_account
= 0;
5964 __setup("swapaccount=", enable_swap_account
);
5966 static u64
swap_current_read(struct cgroup_subsys_state
*css
,
5969 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
5971 return (u64
)page_counter_read(&memcg
->swap
) * PAGE_SIZE
;
5974 static int swap_max_show(struct seq_file
*m
, void *v
)
5976 struct mem_cgroup
*memcg
= mem_cgroup_from_css(seq_css(m
));
5977 unsigned long max
= READ_ONCE(memcg
->swap
.limit
);
5979 if (max
== PAGE_COUNTER_MAX
)
5980 seq_puts(m
, "max\n");
5982 seq_printf(m
, "%llu\n", (u64
)max
* PAGE_SIZE
);
5987 static ssize_t
swap_max_write(struct kernfs_open_file
*of
,
5988 char *buf
, size_t nbytes
, loff_t off
)
5990 struct mem_cgroup
*memcg
= mem_cgroup_from_css(of_css(of
));
5994 buf
= strstrip(buf
);
5995 err
= page_counter_memparse(buf
, "max", &max
);
5999 mutex_lock(&memcg_limit_mutex
);
6000 err
= page_counter_limit(&memcg
->swap
, max
);
6001 mutex_unlock(&memcg_limit_mutex
);
6008 static struct cftype swap_files
[] = {
6010 .name
= "swap.current",
6011 .flags
= CFTYPE_NOT_ON_ROOT
,
6012 .read_u64
= swap_current_read
,
6016 .flags
= CFTYPE_NOT_ON_ROOT
,
6017 .seq_show
= swap_max_show
,
6018 .write
= swap_max_write
,
6023 static struct cftype memsw_cgroup_files
[] = {
6025 .name
= "memsw.usage_in_bytes",
6026 .private = MEMFILE_PRIVATE(_MEMSWAP
, RES_USAGE
),
6027 .read_u64
= mem_cgroup_read_u64
,
6030 .name
= "memsw.max_usage_in_bytes",
6031 .private = MEMFILE_PRIVATE(_MEMSWAP
, RES_MAX_USAGE
),
6032 .write
= mem_cgroup_reset
,
6033 .read_u64
= mem_cgroup_read_u64
,
6036 .name
= "memsw.limit_in_bytes",
6037 .private = MEMFILE_PRIVATE(_MEMSWAP
, RES_LIMIT
),
6038 .write
= mem_cgroup_write
,
6039 .read_u64
= mem_cgroup_read_u64
,
6042 .name
= "memsw.failcnt",
6043 .private = MEMFILE_PRIVATE(_MEMSWAP
, RES_FAILCNT
),
6044 .write
= mem_cgroup_reset
,
6045 .read_u64
= mem_cgroup_read_u64
,
6047 { }, /* terminate */
6050 static int __init
mem_cgroup_swap_init(void)
6052 if (!mem_cgroup_disabled() && really_do_swap_account
) {
6053 do_swap_account
= 1;
6054 WARN_ON(cgroup_add_dfl_cftypes(&memory_cgrp_subsys
,
6056 WARN_ON(cgroup_add_legacy_cftypes(&memory_cgrp_subsys
,
6057 memsw_cgroup_files
));
6061 subsys_initcall(mem_cgroup_swap_init
);
6063 #endif /* CONFIG_MEMCG_SWAP */