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 mem_cgroup
*from
;
211 struct mem_cgroup
*to
;
213 unsigned long precharge
;
214 unsigned long moved_charge
;
215 unsigned long moved_swap
;
216 struct task_struct
*moving_task
; /* a task moving charges */
217 wait_queue_head_t waitq
; /* a waitq for other context */
219 .lock
= __SPIN_LOCK_UNLOCKED(mc
.lock
),
220 .waitq
= __WAIT_QUEUE_HEAD_INITIALIZER(mc
.waitq
),
224 * Maximum loops in mem_cgroup_hierarchical_reclaim(), used for soft
225 * limit reclaim to prevent infinite loops, if they ever occur.
227 #define MEM_CGROUP_MAX_RECLAIM_LOOPS 100
228 #define MEM_CGROUP_MAX_SOFT_LIMIT_RECLAIM_LOOPS 2
231 MEM_CGROUP_CHARGE_TYPE_CACHE
= 0,
232 MEM_CGROUP_CHARGE_TYPE_ANON
,
233 MEM_CGROUP_CHARGE_TYPE_SWAPOUT
, /* for accounting swapcache */
234 MEM_CGROUP_CHARGE_TYPE_DROP
, /* a page was unused swap cache */
238 /* for encoding cft->private value on file */
247 #define MEMFILE_PRIVATE(x, val) ((x) << 16 | (val))
248 #define MEMFILE_TYPE(val) ((val) >> 16 & 0xffff)
249 #define MEMFILE_ATTR(val) ((val) & 0xffff)
250 /* Used for OOM nofiier */
251 #define OOM_CONTROL (0)
253 /* Some nice accessors for the vmpressure. */
254 struct vmpressure
*memcg_to_vmpressure(struct mem_cgroup
*memcg
)
257 memcg
= root_mem_cgroup
;
258 return &memcg
->vmpressure
;
261 struct cgroup_subsys_state
*vmpressure_to_css(struct vmpressure
*vmpr
)
263 return &container_of(vmpr
, struct mem_cgroup
, vmpressure
)->css
;
266 static inline bool mem_cgroup_is_root(struct mem_cgroup
*memcg
)
268 return (memcg
== root_mem_cgroup
);
272 * We restrict the id in the range of [1, 65535], so it can fit into
275 #define MEM_CGROUP_ID_MAX USHRT_MAX
277 static inline unsigned short mem_cgroup_id(struct mem_cgroup
*memcg
)
279 return memcg
->css
.id
;
283 * A helper function to get mem_cgroup from ID. must be called under
284 * rcu_read_lock(). The caller is responsible for calling
285 * css_tryget_online() if the mem_cgroup is used for charging. (dropping
286 * refcnt from swap can be called against removed memcg.)
288 static inline struct mem_cgroup
*mem_cgroup_from_id(unsigned short id
)
290 struct cgroup_subsys_state
*css
;
292 css
= css_from_id(id
, &memory_cgrp_subsys
);
293 return mem_cgroup_from_css(css
);
298 * This will be the memcg's index in each cache's ->memcg_params.memcg_caches.
299 * The main reason for not using cgroup id for this:
300 * this works better in sparse environments, where we have a lot of memcgs,
301 * but only a few kmem-limited. Or also, if we have, for instance, 200
302 * memcgs, and none but the 200th is kmem-limited, we'd have to have a
303 * 200 entry array for that.
305 * The current size of the caches array is stored in memcg_nr_cache_ids. It
306 * will double each time we have to increase it.
308 static DEFINE_IDA(memcg_cache_ida
);
309 int memcg_nr_cache_ids
;
311 /* Protects memcg_nr_cache_ids */
312 static DECLARE_RWSEM(memcg_cache_ids_sem
);
314 void memcg_get_cache_ids(void)
316 down_read(&memcg_cache_ids_sem
);
319 void memcg_put_cache_ids(void)
321 up_read(&memcg_cache_ids_sem
);
325 * MIN_SIZE is different than 1, because we would like to avoid going through
326 * the alloc/free process all the time. In a small machine, 4 kmem-limited
327 * cgroups is a reasonable guess. In the future, it could be a parameter or
328 * tunable, but that is strictly not necessary.
330 * MAX_SIZE should be as large as the number of cgrp_ids. Ideally, we could get
331 * this constant directly from cgroup, but it is understandable that this is
332 * better kept as an internal representation in cgroup.c. In any case, the
333 * cgrp_id space is not getting any smaller, and we don't have to necessarily
334 * increase ours as well if it increases.
336 #define MEMCG_CACHES_MIN_SIZE 4
337 #define MEMCG_CACHES_MAX_SIZE MEM_CGROUP_ID_MAX
340 * A lot of the calls to the cache allocation functions are expected to be
341 * inlined by the compiler. Since the calls to memcg_kmem_get_cache are
342 * conditional to this static branch, we'll have to allow modules that does
343 * kmem_cache_alloc and the such to see this symbol as well
345 DEFINE_STATIC_KEY_FALSE(memcg_kmem_enabled_key
);
346 EXPORT_SYMBOL(memcg_kmem_enabled_key
);
348 #endif /* !CONFIG_SLOB */
350 static struct mem_cgroup_per_zone
*
351 mem_cgroup_zone_zoneinfo(struct mem_cgroup
*memcg
, struct zone
*zone
)
353 int nid
= zone_to_nid(zone
);
354 int zid
= zone_idx(zone
);
356 return &memcg
->nodeinfo
[nid
]->zoneinfo
[zid
];
360 * mem_cgroup_css_from_page - css of the memcg associated with a page
361 * @page: page of interest
363 * If memcg is bound to the default hierarchy, css of the memcg associated
364 * with @page is returned. The returned css remains associated with @page
365 * until it is released.
367 * If memcg is bound to a traditional hierarchy, the css of root_mem_cgroup
370 struct cgroup_subsys_state
*mem_cgroup_css_from_page(struct page
*page
)
372 struct mem_cgroup
*memcg
;
374 memcg
= page
->mem_cgroup
;
376 if (!memcg
|| !cgroup_subsys_on_dfl(memory_cgrp_subsys
))
377 memcg
= root_mem_cgroup
;
383 * page_cgroup_ino - return inode number of the memcg a page is charged to
386 * Look up the closest online ancestor of the memory cgroup @page is charged to
387 * and return its inode number or 0 if @page is not charged to any cgroup. It
388 * is safe to call this function without holding a reference to @page.
390 * Note, this function is inherently racy, because there is nothing to prevent
391 * the cgroup inode from getting torn down and potentially reallocated a moment
392 * after page_cgroup_ino() returns, so it only should be used by callers that
393 * do not care (such as procfs interfaces).
395 ino_t
page_cgroup_ino(struct page
*page
)
397 struct mem_cgroup
*memcg
;
398 unsigned long ino
= 0;
401 memcg
= READ_ONCE(page
->mem_cgroup
);
402 while (memcg
&& !(memcg
->css
.flags
& CSS_ONLINE
))
403 memcg
= parent_mem_cgroup(memcg
);
405 ino
= cgroup_ino(memcg
->css
.cgroup
);
410 static struct mem_cgroup_per_zone
*
411 mem_cgroup_page_zoneinfo(struct mem_cgroup
*memcg
, struct page
*page
)
413 int nid
= page_to_nid(page
);
414 int zid
= page_zonenum(page
);
416 return &memcg
->nodeinfo
[nid
]->zoneinfo
[zid
];
419 static struct mem_cgroup_tree_per_zone
*
420 soft_limit_tree_node_zone(int nid
, int zid
)
422 return &soft_limit_tree
.rb_tree_per_node
[nid
]->rb_tree_per_zone
[zid
];
425 static struct mem_cgroup_tree_per_zone
*
426 soft_limit_tree_from_page(struct page
*page
)
428 int nid
= page_to_nid(page
);
429 int zid
= page_zonenum(page
);
431 return &soft_limit_tree
.rb_tree_per_node
[nid
]->rb_tree_per_zone
[zid
];
434 static void __mem_cgroup_insert_exceeded(struct mem_cgroup_per_zone
*mz
,
435 struct mem_cgroup_tree_per_zone
*mctz
,
436 unsigned long new_usage_in_excess
)
438 struct rb_node
**p
= &mctz
->rb_root
.rb_node
;
439 struct rb_node
*parent
= NULL
;
440 struct mem_cgroup_per_zone
*mz_node
;
445 mz
->usage_in_excess
= new_usage_in_excess
;
446 if (!mz
->usage_in_excess
)
450 mz_node
= rb_entry(parent
, struct mem_cgroup_per_zone
,
452 if (mz
->usage_in_excess
< mz_node
->usage_in_excess
)
455 * We can't avoid mem cgroups that are over their soft
456 * limit by the same amount
458 else if (mz
->usage_in_excess
>= mz_node
->usage_in_excess
)
461 rb_link_node(&mz
->tree_node
, parent
, p
);
462 rb_insert_color(&mz
->tree_node
, &mctz
->rb_root
);
466 static void __mem_cgroup_remove_exceeded(struct mem_cgroup_per_zone
*mz
,
467 struct mem_cgroup_tree_per_zone
*mctz
)
471 rb_erase(&mz
->tree_node
, &mctz
->rb_root
);
475 static void mem_cgroup_remove_exceeded(struct mem_cgroup_per_zone
*mz
,
476 struct mem_cgroup_tree_per_zone
*mctz
)
480 spin_lock_irqsave(&mctz
->lock
, flags
);
481 __mem_cgroup_remove_exceeded(mz
, mctz
);
482 spin_unlock_irqrestore(&mctz
->lock
, flags
);
485 static unsigned long soft_limit_excess(struct mem_cgroup
*memcg
)
487 unsigned long nr_pages
= page_counter_read(&memcg
->memory
);
488 unsigned long soft_limit
= READ_ONCE(memcg
->soft_limit
);
489 unsigned long excess
= 0;
491 if (nr_pages
> soft_limit
)
492 excess
= nr_pages
- soft_limit
;
497 static void mem_cgroup_update_tree(struct mem_cgroup
*memcg
, struct page
*page
)
499 unsigned long excess
;
500 struct mem_cgroup_per_zone
*mz
;
501 struct mem_cgroup_tree_per_zone
*mctz
;
503 mctz
= soft_limit_tree_from_page(page
);
505 * Necessary to update all ancestors when hierarchy is used.
506 * because their event counter is not touched.
508 for (; memcg
; memcg
= parent_mem_cgroup(memcg
)) {
509 mz
= mem_cgroup_page_zoneinfo(memcg
, page
);
510 excess
= soft_limit_excess(memcg
);
512 * We have to update the tree if mz is on RB-tree or
513 * mem is over its softlimit.
515 if (excess
|| mz
->on_tree
) {
518 spin_lock_irqsave(&mctz
->lock
, flags
);
519 /* if on-tree, remove it */
521 __mem_cgroup_remove_exceeded(mz
, mctz
);
523 * Insert again. mz->usage_in_excess will be updated.
524 * If excess is 0, no tree ops.
526 __mem_cgroup_insert_exceeded(mz
, mctz
, excess
);
527 spin_unlock_irqrestore(&mctz
->lock
, flags
);
532 static void mem_cgroup_remove_from_trees(struct mem_cgroup
*memcg
)
534 struct mem_cgroup_tree_per_zone
*mctz
;
535 struct mem_cgroup_per_zone
*mz
;
539 for (zid
= 0; zid
< MAX_NR_ZONES
; zid
++) {
540 mz
= &memcg
->nodeinfo
[nid
]->zoneinfo
[zid
];
541 mctz
= soft_limit_tree_node_zone(nid
, zid
);
542 mem_cgroup_remove_exceeded(mz
, mctz
);
547 static struct mem_cgroup_per_zone
*
548 __mem_cgroup_largest_soft_limit_node(struct mem_cgroup_tree_per_zone
*mctz
)
550 struct rb_node
*rightmost
= NULL
;
551 struct mem_cgroup_per_zone
*mz
;
555 rightmost
= rb_last(&mctz
->rb_root
);
557 goto done
; /* Nothing to reclaim from */
559 mz
= rb_entry(rightmost
, struct mem_cgroup_per_zone
, tree_node
);
561 * Remove the node now but someone else can add it back,
562 * we will to add it back at the end of reclaim to its correct
563 * position in the tree.
565 __mem_cgroup_remove_exceeded(mz
, mctz
);
566 if (!soft_limit_excess(mz
->memcg
) ||
567 !css_tryget_online(&mz
->memcg
->css
))
573 static struct mem_cgroup_per_zone
*
574 mem_cgroup_largest_soft_limit_node(struct mem_cgroup_tree_per_zone
*mctz
)
576 struct mem_cgroup_per_zone
*mz
;
578 spin_lock_irq(&mctz
->lock
);
579 mz
= __mem_cgroup_largest_soft_limit_node(mctz
);
580 spin_unlock_irq(&mctz
->lock
);
585 * Return page count for single (non recursive) @memcg.
587 * Implementation Note: reading percpu statistics for memcg.
589 * Both of vmstat[] and percpu_counter has threshold and do periodic
590 * synchronization to implement "quick" read. There are trade-off between
591 * reading cost and precision of value. Then, we may have a chance to implement
592 * a periodic synchronization of counter in memcg's counter.
594 * But this _read() function is used for user interface now. The user accounts
595 * memory usage by memory cgroup and he _always_ requires exact value because
596 * he accounts memory. Even if we provide quick-and-fuzzy read, we always
597 * have to visit all online cpus and make sum. So, for now, unnecessary
598 * synchronization is not implemented. (just implemented for cpu hotplug)
600 * If there are kernel internal actions which can make use of some not-exact
601 * value, and reading all cpu value can be performance bottleneck in some
602 * common workload, threshold and synchronization as vmstat[] should be
606 mem_cgroup_read_stat(struct mem_cgroup
*memcg
, enum mem_cgroup_stat_index idx
)
611 /* Per-cpu values can be negative, use a signed accumulator */
612 for_each_possible_cpu(cpu
)
613 val
+= per_cpu(memcg
->stat
->count
[idx
], cpu
);
615 * Summing races with updates, so val may be negative. Avoid exposing
616 * transient negative values.
623 static unsigned long mem_cgroup_read_events(struct mem_cgroup
*memcg
,
624 enum mem_cgroup_events_index idx
)
626 unsigned long val
= 0;
629 for_each_possible_cpu(cpu
)
630 val
+= per_cpu(memcg
->stat
->events
[idx
], cpu
);
634 static void mem_cgroup_charge_statistics(struct mem_cgroup
*memcg
,
636 bool compound
, int nr_pages
)
639 * Here, RSS means 'mapped anon' and anon's SwapCache. Shmem/tmpfs is
640 * counted as CACHE even if it's on ANON LRU.
643 __this_cpu_add(memcg
->stat
->count
[MEM_CGROUP_STAT_RSS
],
646 __this_cpu_add(memcg
->stat
->count
[MEM_CGROUP_STAT_CACHE
],
650 VM_BUG_ON_PAGE(!PageTransHuge(page
), page
);
651 __this_cpu_add(memcg
->stat
->count
[MEM_CGROUP_STAT_RSS_HUGE
],
655 /* pagein of a big page is an event. So, ignore page size */
657 __this_cpu_inc(memcg
->stat
->events
[MEM_CGROUP_EVENTS_PGPGIN
]);
659 __this_cpu_inc(memcg
->stat
->events
[MEM_CGROUP_EVENTS_PGPGOUT
]);
660 nr_pages
= -nr_pages
; /* for event */
663 __this_cpu_add(memcg
->stat
->nr_page_events
, nr_pages
);
666 static unsigned long mem_cgroup_node_nr_lru_pages(struct mem_cgroup
*memcg
,
668 unsigned int lru_mask
)
670 unsigned long nr
= 0;
673 VM_BUG_ON((unsigned)nid
>= nr_node_ids
);
675 for (zid
= 0; zid
< MAX_NR_ZONES
; zid
++) {
676 struct mem_cgroup_per_zone
*mz
;
680 if (!(BIT(lru
) & lru_mask
))
682 mz
= &memcg
->nodeinfo
[nid
]->zoneinfo
[zid
];
683 nr
+= mz
->lru_size
[lru
];
689 static unsigned long mem_cgroup_nr_lru_pages(struct mem_cgroup
*memcg
,
690 unsigned int lru_mask
)
692 unsigned long nr
= 0;
695 for_each_node_state(nid
, N_MEMORY
)
696 nr
+= mem_cgroup_node_nr_lru_pages(memcg
, nid
, lru_mask
);
700 static bool mem_cgroup_event_ratelimit(struct mem_cgroup
*memcg
,
701 enum mem_cgroup_events_target target
)
703 unsigned long val
, next
;
705 val
= __this_cpu_read(memcg
->stat
->nr_page_events
);
706 next
= __this_cpu_read(memcg
->stat
->targets
[target
]);
707 /* from time_after() in jiffies.h */
708 if ((long)next
- (long)val
< 0) {
710 case MEM_CGROUP_TARGET_THRESH
:
711 next
= val
+ THRESHOLDS_EVENTS_TARGET
;
713 case MEM_CGROUP_TARGET_SOFTLIMIT
:
714 next
= val
+ SOFTLIMIT_EVENTS_TARGET
;
716 case MEM_CGROUP_TARGET_NUMAINFO
:
717 next
= val
+ NUMAINFO_EVENTS_TARGET
;
722 __this_cpu_write(memcg
->stat
->targets
[target
], next
);
729 * Check events in order.
732 static void memcg_check_events(struct mem_cgroup
*memcg
, struct page
*page
)
734 /* threshold event is triggered in finer grain than soft limit */
735 if (unlikely(mem_cgroup_event_ratelimit(memcg
,
736 MEM_CGROUP_TARGET_THRESH
))) {
738 bool do_numainfo __maybe_unused
;
740 do_softlimit
= mem_cgroup_event_ratelimit(memcg
,
741 MEM_CGROUP_TARGET_SOFTLIMIT
);
743 do_numainfo
= mem_cgroup_event_ratelimit(memcg
,
744 MEM_CGROUP_TARGET_NUMAINFO
);
746 mem_cgroup_threshold(memcg
);
747 if (unlikely(do_softlimit
))
748 mem_cgroup_update_tree(memcg
, page
);
750 if (unlikely(do_numainfo
))
751 atomic_inc(&memcg
->numainfo_events
);
756 struct mem_cgroup
*mem_cgroup_from_task(struct task_struct
*p
)
759 * mm_update_next_owner() may clear mm->owner to NULL
760 * if it races with swapoff, page migration, etc.
761 * So this can be called with p == NULL.
766 return mem_cgroup_from_css(task_css(p
, memory_cgrp_id
));
768 EXPORT_SYMBOL(mem_cgroup_from_task
);
770 static struct mem_cgroup
*get_mem_cgroup_from_mm(struct mm_struct
*mm
)
772 struct mem_cgroup
*memcg
= NULL
;
777 * Page cache insertions can happen withou an
778 * actual mm context, e.g. during disk probing
779 * on boot, loopback IO, acct() writes etc.
782 memcg
= root_mem_cgroup
;
784 memcg
= mem_cgroup_from_task(rcu_dereference(mm
->owner
));
785 if (unlikely(!memcg
))
786 memcg
= root_mem_cgroup
;
788 } while (!css_tryget_online(&memcg
->css
));
794 * mem_cgroup_iter - iterate over memory cgroup hierarchy
795 * @root: hierarchy root
796 * @prev: previously returned memcg, NULL on first invocation
797 * @reclaim: cookie for shared reclaim walks, NULL for full walks
799 * Returns references to children of the hierarchy below @root, or
800 * @root itself, or %NULL after a full round-trip.
802 * Caller must pass the return value in @prev on subsequent
803 * invocations for reference counting, or use mem_cgroup_iter_break()
804 * to cancel a hierarchy walk before the round-trip is complete.
806 * Reclaimers can specify a zone and a priority level in @reclaim to
807 * divide up the memcgs in the hierarchy among all concurrent
808 * reclaimers operating on the same zone and priority.
810 struct mem_cgroup
*mem_cgroup_iter(struct mem_cgroup
*root
,
811 struct mem_cgroup
*prev
,
812 struct mem_cgroup_reclaim_cookie
*reclaim
)
814 struct mem_cgroup_reclaim_iter
*uninitialized_var(iter
);
815 struct cgroup_subsys_state
*css
= NULL
;
816 struct mem_cgroup
*memcg
= NULL
;
817 struct mem_cgroup
*pos
= NULL
;
819 if (mem_cgroup_disabled())
823 root
= root_mem_cgroup
;
825 if (prev
&& !reclaim
)
828 if (!root
->use_hierarchy
&& root
!= root_mem_cgroup
) {
837 struct mem_cgroup_per_zone
*mz
;
839 mz
= mem_cgroup_zone_zoneinfo(root
, reclaim
->zone
);
840 iter
= &mz
->iter
[reclaim
->priority
];
842 if (prev
&& reclaim
->generation
!= iter
->generation
)
846 pos
= READ_ONCE(iter
->position
);
847 if (!pos
|| css_tryget(&pos
->css
))
850 * css reference reached zero, so iter->position will
851 * be cleared by ->css_released. However, we should not
852 * rely on this happening soon, because ->css_released
853 * is called from a work queue, and by busy-waiting we
854 * might block it. So we clear iter->position right
857 (void)cmpxchg(&iter
->position
, pos
, NULL
);
865 css
= css_next_descendant_pre(css
, &root
->css
);
868 * Reclaimers share the hierarchy walk, and a
869 * new one might jump in right at the end of
870 * the hierarchy - make sure they see at least
871 * one group and restart from the beginning.
879 * Verify the css and acquire a reference. The root
880 * is provided by the caller, so we know it's alive
881 * and kicking, and don't take an extra reference.
883 memcg
= mem_cgroup_from_css(css
);
885 if (css
== &root
->css
)
896 * The position could have already been updated by a competing
897 * thread, so check that the value hasn't changed since we read
898 * it to avoid reclaiming from the same cgroup twice.
900 (void)cmpxchg(&iter
->position
, pos
, memcg
);
908 reclaim
->generation
= iter
->generation
;
914 if (prev
&& prev
!= root
)
921 * mem_cgroup_iter_break - abort a hierarchy walk prematurely
922 * @root: hierarchy root
923 * @prev: last visited hierarchy member as returned by mem_cgroup_iter()
925 void mem_cgroup_iter_break(struct mem_cgroup
*root
,
926 struct mem_cgroup
*prev
)
929 root
= root_mem_cgroup
;
930 if (prev
&& prev
!= root
)
934 static void invalidate_reclaim_iterators(struct mem_cgroup
*dead_memcg
)
936 struct mem_cgroup
*memcg
= dead_memcg
;
937 struct mem_cgroup_reclaim_iter
*iter
;
938 struct mem_cgroup_per_zone
*mz
;
942 while ((memcg
= parent_mem_cgroup(memcg
))) {
944 for (zid
= 0; zid
< MAX_NR_ZONES
; zid
++) {
945 mz
= &memcg
->nodeinfo
[nid
]->zoneinfo
[zid
];
946 for (i
= 0; i
<= DEF_PRIORITY
; i
++) {
948 cmpxchg(&iter
->position
,
957 * Iteration constructs for visiting all cgroups (under a tree). If
958 * loops are exited prematurely (break), mem_cgroup_iter_break() must
959 * be used for reference counting.
961 #define for_each_mem_cgroup_tree(iter, root) \
962 for (iter = mem_cgroup_iter(root, NULL, NULL); \
964 iter = mem_cgroup_iter(root, iter, NULL))
966 #define for_each_mem_cgroup(iter) \
967 for (iter = mem_cgroup_iter(NULL, NULL, NULL); \
969 iter = mem_cgroup_iter(NULL, iter, NULL))
972 * mem_cgroup_zone_lruvec - get the lru list vector for a zone and memcg
973 * @zone: zone of the wanted lruvec
974 * @memcg: memcg of the wanted lruvec
976 * Returns the lru list vector holding pages for the given @zone and
977 * @mem. This can be the global zone lruvec, if the memory controller
980 struct lruvec
*mem_cgroup_zone_lruvec(struct zone
*zone
,
981 struct mem_cgroup
*memcg
)
983 struct mem_cgroup_per_zone
*mz
;
984 struct lruvec
*lruvec
;
986 if (mem_cgroup_disabled()) {
987 lruvec
= &zone
->lruvec
;
991 mz
= mem_cgroup_zone_zoneinfo(memcg
, zone
);
992 lruvec
= &mz
->lruvec
;
995 * Since a node can be onlined after the mem_cgroup was created,
996 * we have to be prepared to initialize lruvec->zone here;
997 * and if offlined then reonlined, we need to reinitialize it.
999 if (unlikely(lruvec
->zone
!= zone
))
1000 lruvec
->zone
= zone
;
1005 * mem_cgroup_page_lruvec - return lruvec for isolating/putting an LRU page
1007 * @zone: zone of the page
1009 * This function is only safe when following the LRU page isolation
1010 * and putback protocol: the LRU lock must be held, and the page must
1011 * either be PageLRU() or the caller must have isolated/allocated it.
1013 struct lruvec
*mem_cgroup_page_lruvec(struct page
*page
, struct zone
*zone
)
1015 struct mem_cgroup_per_zone
*mz
;
1016 struct mem_cgroup
*memcg
;
1017 struct lruvec
*lruvec
;
1019 if (mem_cgroup_disabled()) {
1020 lruvec
= &zone
->lruvec
;
1024 memcg
= page
->mem_cgroup
;
1026 * Swapcache readahead pages are added to the LRU - and
1027 * possibly migrated - before they are charged.
1030 memcg
= root_mem_cgroup
;
1032 mz
= mem_cgroup_page_zoneinfo(memcg
, page
);
1033 lruvec
= &mz
->lruvec
;
1036 * Since a node can be onlined after the mem_cgroup was created,
1037 * we have to be prepared to initialize lruvec->zone here;
1038 * and if offlined then reonlined, we need to reinitialize it.
1040 if (unlikely(lruvec
->zone
!= zone
))
1041 lruvec
->zone
= zone
;
1046 * mem_cgroup_update_lru_size - account for adding or removing an lru page
1047 * @lruvec: mem_cgroup per zone lru vector
1048 * @lru: index of lru list the page is sitting on
1049 * @nr_pages: positive when adding or negative when removing
1051 * This function must be called when a page is added to or removed from an
1054 void mem_cgroup_update_lru_size(struct lruvec
*lruvec
, enum lru_list lru
,
1057 struct mem_cgroup_per_zone
*mz
;
1058 unsigned long *lru_size
;
1060 if (mem_cgroup_disabled())
1063 mz
= container_of(lruvec
, struct mem_cgroup_per_zone
, lruvec
);
1064 lru_size
= mz
->lru_size
+ lru
;
1065 *lru_size
+= nr_pages
;
1066 VM_BUG_ON((long)(*lru_size
) < 0);
1069 bool task_in_mem_cgroup(struct task_struct
*task
, struct mem_cgroup
*memcg
)
1071 struct mem_cgroup
*task_memcg
;
1072 struct task_struct
*p
;
1075 p
= find_lock_task_mm(task
);
1077 task_memcg
= get_mem_cgroup_from_mm(p
->mm
);
1081 * All threads may have already detached their mm's, but the oom
1082 * killer still needs to detect if they have already been oom
1083 * killed to prevent needlessly killing additional tasks.
1086 task_memcg
= mem_cgroup_from_task(task
);
1087 css_get(&task_memcg
->css
);
1090 ret
= mem_cgroup_is_descendant(task_memcg
, memcg
);
1091 css_put(&task_memcg
->css
);
1096 * mem_cgroup_margin - calculate chargeable space of a memory cgroup
1097 * @memcg: the memory cgroup
1099 * Returns the maximum amount of memory @mem can be charged with, in
1102 static unsigned long mem_cgroup_margin(struct mem_cgroup
*memcg
)
1104 unsigned long margin
= 0;
1105 unsigned long count
;
1106 unsigned long limit
;
1108 count
= page_counter_read(&memcg
->memory
);
1109 limit
= READ_ONCE(memcg
->memory
.limit
);
1111 margin
= limit
- count
;
1113 if (do_memsw_account()) {
1114 count
= page_counter_read(&memcg
->memsw
);
1115 limit
= READ_ONCE(memcg
->memsw
.limit
);
1117 margin
= min(margin
, limit
- count
);
1124 * A routine for checking "mem" is under move_account() or not.
1126 * Checking a cgroup is mc.from or mc.to or under hierarchy of
1127 * moving cgroups. This is for waiting at high-memory pressure
1130 static bool mem_cgroup_under_move(struct mem_cgroup
*memcg
)
1132 struct mem_cgroup
*from
;
1133 struct mem_cgroup
*to
;
1136 * Unlike task_move routines, we access mc.to, mc.from not under
1137 * mutual exclusion by cgroup_mutex. Here, we take spinlock instead.
1139 spin_lock(&mc
.lock
);
1145 ret
= mem_cgroup_is_descendant(from
, memcg
) ||
1146 mem_cgroup_is_descendant(to
, memcg
);
1148 spin_unlock(&mc
.lock
);
1152 static bool mem_cgroup_wait_acct_move(struct mem_cgroup
*memcg
)
1154 if (mc
.moving_task
&& current
!= mc
.moving_task
) {
1155 if (mem_cgroup_under_move(memcg
)) {
1157 prepare_to_wait(&mc
.waitq
, &wait
, TASK_INTERRUPTIBLE
);
1158 /* moving charge context might have finished. */
1161 finish_wait(&mc
.waitq
, &wait
);
1168 #define K(x) ((x) << (PAGE_SHIFT-10))
1170 * mem_cgroup_print_oom_info: Print OOM information relevant to memory controller.
1171 * @memcg: The memory cgroup that went over limit
1172 * @p: Task that is going to be killed
1174 * NOTE: @memcg and @p's mem_cgroup can be different when hierarchy is
1177 void mem_cgroup_print_oom_info(struct mem_cgroup
*memcg
, struct task_struct
*p
)
1179 /* oom_info_lock ensures that parallel ooms do not interleave */
1180 static DEFINE_MUTEX(oom_info_lock
);
1181 struct mem_cgroup
*iter
;
1184 mutex_lock(&oom_info_lock
);
1188 pr_info("Task in ");
1189 pr_cont_cgroup_path(task_cgroup(p
, memory_cgrp_id
));
1190 pr_cont(" killed as a result of limit of ");
1192 pr_info("Memory limit reached of cgroup ");
1195 pr_cont_cgroup_path(memcg
->css
.cgroup
);
1200 pr_info("memory: usage %llukB, limit %llukB, failcnt %lu\n",
1201 K((u64
)page_counter_read(&memcg
->memory
)),
1202 K((u64
)memcg
->memory
.limit
), memcg
->memory
.failcnt
);
1203 pr_info("memory+swap: usage %llukB, limit %llukB, failcnt %lu\n",
1204 K((u64
)page_counter_read(&memcg
->memsw
)),
1205 K((u64
)memcg
->memsw
.limit
), memcg
->memsw
.failcnt
);
1206 pr_info("kmem: usage %llukB, limit %llukB, failcnt %lu\n",
1207 K((u64
)page_counter_read(&memcg
->kmem
)),
1208 K((u64
)memcg
->kmem
.limit
), memcg
->kmem
.failcnt
);
1210 for_each_mem_cgroup_tree(iter
, memcg
) {
1211 pr_info("Memory cgroup stats for ");
1212 pr_cont_cgroup_path(iter
->css
.cgroup
);
1215 for (i
= 0; i
< MEM_CGROUP_STAT_NSTATS
; i
++) {
1216 if (i
== MEM_CGROUP_STAT_SWAP
&& !do_swap_account
)
1218 pr_cont(" %s:%luKB", mem_cgroup_stat_names
[i
],
1219 K(mem_cgroup_read_stat(iter
, i
)));
1222 for (i
= 0; i
< NR_LRU_LISTS
; i
++)
1223 pr_cont(" %s:%luKB", mem_cgroup_lru_names
[i
],
1224 K(mem_cgroup_nr_lru_pages(iter
, BIT(i
))));
1228 mutex_unlock(&oom_info_lock
);
1232 * This function returns the number of memcg under hierarchy tree. Returns
1233 * 1(self count) if no children.
1235 static int mem_cgroup_count_children(struct mem_cgroup
*memcg
)
1238 struct mem_cgroup
*iter
;
1240 for_each_mem_cgroup_tree(iter
, memcg
)
1246 * Return the memory (and swap, if configured) limit for a memcg.
1248 static unsigned long mem_cgroup_get_limit(struct mem_cgroup
*memcg
)
1250 unsigned long limit
;
1252 limit
= memcg
->memory
.limit
;
1253 if (mem_cgroup_swappiness(memcg
)) {
1254 unsigned long memsw_limit
;
1255 unsigned long swap_limit
;
1257 memsw_limit
= memcg
->memsw
.limit
;
1258 swap_limit
= memcg
->swap
.limit
;
1259 swap_limit
= min(swap_limit
, (unsigned long)total_swap_pages
);
1260 limit
= min(limit
+ swap_limit
, memsw_limit
);
1265 static void mem_cgroup_out_of_memory(struct mem_cgroup
*memcg
, gfp_t gfp_mask
,
1268 struct oom_control oc
= {
1271 .gfp_mask
= gfp_mask
,
1274 struct mem_cgroup
*iter
;
1275 unsigned long chosen_points
= 0;
1276 unsigned long totalpages
;
1277 unsigned int points
= 0;
1278 struct task_struct
*chosen
= NULL
;
1280 mutex_lock(&oom_lock
);
1283 * If current has a pending SIGKILL or is exiting, then automatically
1284 * select it. The goal is to allow it to allocate so that it may
1285 * quickly exit and free its memory.
1287 if (fatal_signal_pending(current
) || task_will_free_mem(current
)) {
1288 mark_oom_victim(current
);
1292 check_panic_on_oom(&oc
, CONSTRAINT_MEMCG
, memcg
);
1293 totalpages
= mem_cgroup_get_limit(memcg
) ? : 1;
1294 for_each_mem_cgroup_tree(iter
, memcg
) {
1295 struct css_task_iter it
;
1296 struct task_struct
*task
;
1298 css_task_iter_start(&iter
->css
, &it
);
1299 while ((task
= css_task_iter_next(&it
))) {
1300 switch (oom_scan_process_thread(&oc
, task
, totalpages
)) {
1301 case OOM_SCAN_SELECT
:
1303 put_task_struct(chosen
);
1305 chosen_points
= ULONG_MAX
;
1306 get_task_struct(chosen
);
1308 case OOM_SCAN_CONTINUE
:
1310 case OOM_SCAN_ABORT
:
1311 css_task_iter_end(&it
);
1312 mem_cgroup_iter_break(memcg
, iter
);
1314 put_task_struct(chosen
);
1319 points
= oom_badness(task
, memcg
, NULL
, totalpages
);
1320 if (!points
|| points
< chosen_points
)
1322 /* Prefer thread group leaders for display purposes */
1323 if (points
== chosen_points
&&
1324 thread_group_leader(chosen
))
1328 put_task_struct(chosen
);
1330 chosen_points
= points
;
1331 get_task_struct(chosen
);
1333 css_task_iter_end(&it
);
1337 points
= chosen_points
* 1000 / totalpages
;
1338 oom_kill_process(&oc
, chosen
, points
, totalpages
, memcg
,
1339 "Memory cgroup out of memory");
1342 mutex_unlock(&oom_lock
);
1345 #if MAX_NUMNODES > 1
1348 * test_mem_cgroup_node_reclaimable
1349 * @memcg: the target memcg
1350 * @nid: the node ID to be checked.
1351 * @noswap : specify true here if the user wants flle only information.
1353 * This function returns whether the specified memcg contains any
1354 * reclaimable pages on a node. Returns true if there are any reclaimable
1355 * pages in the node.
1357 static bool test_mem_cgroup_node_reclaimable(struct mem_cgroup
*memcg
,
1358 int nid
, bool noswap
)
1360 if (mem_cgroup_node_nr_lru_pages(memcg
, nid
, LRU_ALL_FILE
))
1362 if (noswap
|| !total_swap_pages
)
1364 if (mem_cgroup_node_nr_lru_pages(memcg
, nid
, LRU_ALL_ANON
))
1371 * Always updating the nodemask is not very good - even if we have an empty
1372 * list or the wrong list here, we can start from some node and traverse all
1373 * nodes based on the zonelist. So update the list loosely once per 10 secs.
1376 static void mem_cgroup_may_update_nodemask(struct mem_cgroup
*memcg
)
1380 * numainfo_events > 0 means there was at least NUMAINFO_EVENTS_TARGET
1381 * pagein/pageout changes since the last update.
1383 if (!atomic_read(&memcg
->numainfo_events
))
1385 if (atomic_inc_return(&memcg
->numainfo_updating
) > 1)
1388 /* make a nodemask where this memcg uses memory from */
1389 memcg
->scan_nodes
= node_states
[N_MEMORY
];
1391 for_each_node_mask(nid
, node_states
[N_MEMORY
]) {
1393 if (!test_mem_cgroup_node_reclaimable(memcg
, nid
, false))
1394 node_clear(nid
, memcg
->scan_nodes
);
1397 atomic_set(&memcg
->numainfo_events
, 0);
1398 atomic_set(&memcg
->numainfo_updating
, 0);
1402 * Selecting a node where we start reclaim from. Because what we need is just
1403 * reducing usage counter, start from anywhere is O,K. Considering
1404 * memory reclaim from current node, there are pros. and cons.
1406 * Freeing memory from current node means freeing memory from a node which
1407 * we'll use or we've used. So, it may make LRU bad. And if several threads
1408 * hit limits, it will see a contention on a node. But freeing from remote
1409 * node means more costs for memory reclaim because of memory latency.
1411 * Now, we use round-robin. Better algorithm is welcomed.
1413 int mem_cgroup_select_victim_node(struct mem_cgroup
*memcg
)
1417 mem_cgroup_may_update_nodemask(memcg
);
1418 node
= memcg
->last_scanned_node
;
1420 node
= next_node(node
, memcg
->scan_nodes
);
1421 if (node
== MAX_NUMNODES
)
1422 node
= first_node(memcg
->scan_nodes
);
1424 * We call this when we hit limit, not when pages are added to LRU.
1425 * No LRU may hold pages because all pages are UNEVICTABLE or
1426 * memcg is too small and all pages are not on LRU. In that case,
1427 * we use curret node.
1429 if (unlikely(node
== MAX_NUMNODES
))
1430 node
= numa_node_id();
1432 memcg
->last_scanned_node
= node
;
1436 int mem_cgroup_select_victim_node(struct mem_cgroup
*memcg
)
1442 static int mem_cgroup_soft_reclaim(struct mem_cgroup
*root_memcg
,
1445 unsigned long *total_scanned
)
1447 struct mem_cgroup
*victim
= NULL
;
1450 unsigned long excess
;
1451 unsigned long nr_scanned
;
1452 struct mem_cgroup_reclaim_cookie reclaim
= {
1457 excess
= soft_limit_excess(root_memcg
);
1460 victim
= mem_cgroup_iter(root_memcg
, victim
, &reclaim
);
1465 * If we have not been able to reclaim
1466 * anything, it might because there are
1467 * no reclaimable pages under this hierarchy
1472 * We want to do more targeted reclaim.
1473 * excess >> 2 is not to excessive so as to
1474 * reclaim too much, nor too less that we keep
1475 * coming back to reclaim from this cgroup
1477 if (total
>= (excess
>> 2) ||
1478 (loop
> MEM_CGROUP_MAX_RECLAIM_LOOPS
))
1483 total
+= mem_cgroup_shrink_node_zone(victim
, gfp_mask
, false,
1485 *total_scanned
+= nr_scanned
;
1486 if (!soft_limit_excess(root_memcg
))
1489 mem_cgroup_iter_break(root_memcg
, victim
);
1493 #ifdef CONFIG_LOCKDEP
1494 static struct lockdep_map memcg_oom_lock_dep_map
= {
1495 .name
= "memcg_oom_lock",
1499 static DEFINE_SPINLOCK(memcg_oom_lock
);
1502 * Check OOM-Killer is already running under our hierarchy.
1503 * If someone is running, return false.
1505 static bool mem_cgroup_oom_trylock(struct mem_cgroup
*memcg
)
1507 struct mem_cgroup
*iter
, *failed
= NULL
;
1509 spin_lock(&memcg_oom_lock
);
1511 for_each_mem_cgroup_tree(iter
, memcg
) {
1512 if (iter
->oom_lock
) {
1514 * this subtree of our hierarchy is already locked
1515 * so we cannot give a lock.
1518 mem_cgroup_iter_break(memcg
, iter
);
1521 iter
->oom_lock
= true;
1526 * OK, we failed to lock the whole subtree so we have
1527 * to clean up what we set up to the failing subtree
1529 for_each_mem_cgroup_tree(iter
, memcg
) {
1530 if (iter
== failed
) {
1531 mem_cgroup_iter_break(memcg
, iter
);
1534 iter
->oom_lock
= false;
1537 mutex_acquire(&memcg_oom_lock_dep_map
, 0, 1, _RET_IP_
);
1539 spin_unlock(&memcg_oom_lock
);
1544 static void mem_cgroup_oom_unlock(struct mem_cgroup
*memcg
)
1546 struct mem_cgroup
*iter
;
1548 spin_lock(&memcg_oom_lock
);
1549 mutex_release(&memcg_oom_lock_dep_map
, 1, _RET_IP_
);
1550 for_each_mem_cgroup_tree(iter
, memcg
)
1551 iter
->oom_lock
= false;
1552 spin_unlock(&memcg_oom_lock
);
1555 static void mem_cgroup_mark_under_oom(struct mem_cgroup
*memcg
)
1557 struct mem_cgroup
*iter
;
1559 spin_lock(&memcg_oom_lock
);
1560 for_each_mem_cgroup_tree(iter
, memcg
)
1562 spin_unlock(&memcg_oom_lock
);
1565 static void mem_cgroup_unmark_under_oom(struct mem_cgroup
*memcg
)
1567 struct mem_cgroup
*iter
;
1570 * When a new child is created while the hierarchy is under oom,
1571 * mem_cgroup_oom_lock() may not be called. Watch for underflow.
1573 spin_lock(&memcg_oom_lock
);
1574 for_each_mem_cgroup_tree(iter
, memcg
)
1575 if (iter
->under_oom
> 0)
1577 spin_unlock(&memcg_oom_lock
);
1580 static DECLARE_WAIT_QUEUE_HEAD(memcg_oom_waitq
);
1582 struct oom_wait_info
{
1583 struct mem_cgroup
*memcg
;
1587 static int memcg_oom_wake_function(wait_queue_t
*wait
,
1588 unsigned mode
, int sync
, void *arg
)
1590 struct mem_cgroup
*wake_memcg
= (struct mem_cgroup
*)arg
;
1591 struct mem_cgroup
*oom_wait_memcg
;
1592 struct oom_wait_info
*oom_wait_info
;
1594 oom_wait_info
= container_of(wait
, struct oom_wait_info
, wait
);
1595 oom_wait_memcg
= oom_wait_info
->memcg
;
1597 if (!mem_cgroup_is_descendant(wake_memcg
, oom_wait_memcg
) &&
1598 !mem_cgroup_is_descendant(oom_wait_memcg
, wake_memcg
))
1600 return autoremove_wake_function(wait
, mode
, sync
, arg
);
1603 static void memcg_oom_recover(struct mem_cgroup
*memcg
)
1606 * For the following lockless ->under_oom test, the only required
1607 * guarantee is that it must see the state asserted by an OOM when
1608 * this function is called as a result of userland actions
1609 * triggered by the notification of the OOM. This is trivially
1610 * achieved by invoking mem_cgroup_mark_under_oom() before
1611 * triggering notification.
1613 if (memcg
&& memcg
->under_oom
)
1614 __wake_up(&memcg_oom_waitq
, TASK_NORMAL
, 0, memcg
);
1617 static void mem_cgroup_oom(struct mem_cgroup
*memcg
, gfp_t mask
, int order
)
1619 if (!current
->memcg_may_oom
)
1622 * We are in the middle of the charge context here, so we
1623 * don't want to block when potentially sitting on a callstack
1624 * that holds all kinds of filesystem and mm locks.
1626 * Also, the caller may handle a failed allocation gracefully
1627 * (like optional page cache readahead) and so an OOM killer
1628 * invocation might not even be necessary.
1630 * That's why we don't do anything here except remember the
1631 * OOM context and then deal with it at the end of the page
1632 * fault when the stack is unwound, the locks are released,
1633 * and when we know whether the fault was overall successful.
1635 css_get(&memcg
->css
);
1636 current
->memcg_in_oom
= memcg
;
1637 current
->memcg_oom_gfp_mask
= mask
;
1638 current
->memcg_oom_order
= order
;
1642 * mem_cgroup_oom_synchronize - complete memcg OOM handling
1643 * @handle: actually kill/wait or just clean up the OOM state
1645 * This has to be called at the end of a page fault if the memcg OOM
1646 * handler was enabled.
1648 * Memcg supports userspace OOM handling where failed allocations must
1649 * sleep on a waitqueue until the userspace task resolves the
1650 * situation. Sleeping directly in the charge context with all kinds
1651 * of locks held is not a good idea, instead we remember an OOM state
1652 * in the task and mem_cgroup_oom_synchronize() has to be called at
1653 * the end of the page fault to complete the OOM handling.
1655 * Returns %true if an ongoing memcg OOM situation was detected and
1656 * completed, %false otherwise.
1658 bool mem_cgroup_oom_synchronize(bool handle
)
1660 struct mem_cgroup
*memcg
= current
->memcg_in_oom
;
1661 struct oom_wait_info owait
;
1664 /* OOM is global, do not handle */
1668 if (!handle
|| oom_killer_disabled
)
1671 owait
.memcg
= memcg
;
1672 owait
.wait
.flags
= 0;
1673 owait
.wait
.func
= memcg_oom_wake_function
;
1674 owait
.wait
.private = current
;
1675 INIT_LIST_HEAD(&owait
.wait
.task_list
);
1677 prepare_to_wait(&memcg_oom_waitq
, &owait
.wait
, TASK_KILLABLE
);
1678 mem_cgroup_mark_under_oom(memcg
);
1680 locked
= mem_cgroup_oom_trylock(memcg
);
1683 mem_cgroup_oom_notify(memcg
);
1685 if (locked
&& !memcg
->oom_kill_disable
) {
1686 mem_cgroup_unmark_under_oom(memcg
);
1687 finish_wait(&memcg_oom_waitq
, &owait
.wait
);
1688 mem_cgroup_out_of_memory(memcg
, current
->memcg_oom_gfp_mask
,
1689 current
->memcg_oom_order
);
1692 mem_cgroup_unmark_under_oom(memcg
);
1693 finish_wait(&memcg_oom_waitq
, &owait
.wait
);
1697 mem_cgroup_oom_unlock(memcg
);
1699 * There is no guarantee that an OOM-lock contender
1700 * sees the wakeups triggered by the OOM kill
1701 * uncharges. Wake any sleepers explicitely.
1703 memcg_oom_recover(memcg
);
1706 current
->memcg_in_oom
= NULL
;
1707 css_put(&memcg
->css
);
1712 * mem_cgroup_begin_page_stat - begin a page state statistics transaction
1713 * @page: page that is going to change accounted state
1715 * This function must mark the beginning of an accounted page state
1716 * change to prevent double accounting when the page is concurrently
1717 * being moved to another memcg:
1719 * memcg = mem_cgroup_begin_page_stat(page);
1720 * if (TestClearPageState(page))
1721 * mem_cgroup_update_page_stat(memcg, state, -1);
1722 * mem_cgroup_end_page_stat(memcg);
1724 struct mem_cgroup
*mem_cgroup_begin_page_stat(struct page
*page
)
1726 struct mem_cgroup
*memcg
;
1727 unsigned long flags
;
1730 * The RCU lock is held throughout the transaction. The fast
1731 * path can get away without acquiring the memcg->move_lock
1732 * because page moving starts with an RCU grace period.
1734 * The RCU lock also protects the memcg from being freed when
1735 * the page state that is going to change is the only thing
1736 * preventing the page from being uncharged.
1737 * E.g. end-writeback clearing PageWriteback(), which allows
1738 * migration to go ahead and uncharge the page before the
1739 * account transaction might be complete.
1743 if (mem_cgroup_disabled())
1746 memcg
= page
->mem_cgroup
;
1747 if (unlikely(!memcg
))
1750 if (atomic_read(&memcg
->moving_account
) <= 0)
1753 spin_lock_irqsave(&memcg
->move_lock
, flags
);
1754 if (memcg
!= page
->mem_cgroup
) {
1755 spin_unlock_irqrestore(&memcg
->move_lock
, flags
);
1760 * When charge migration first begins, we can have locked and
1761 * unlocked page stat updates happening concurrently. Track
1762 * the task who has the lock for mem_cgroup_end_page_stat().
1764 memcg
->move_lock_task
= current
;
1765 memcg
->move_lock_flags
= flags
;
1769 EXPORT_SYMBOL(mem_cgroup_begin_page_stat
);
1772 * mem_cgroup_end_page_stat - finish a page state statistics transaction
1773 * @memcg: the memcg that was accounted against
1775 void mem_cgroup_end_page_stat(struct mem_cgroup
*memcg
)
1777 if (memcg
&& memcg
->move_lock_task
== current
) {
1778 unsigned long flags
= memcg
->move_lock_flags
;
1780 memcg
->move_lock_task
= NULL
;
1781 memcg
->move_lock_flags
= 0;
1783 spin_unlock_irqrestore(&memcg
->move_lock
, flags
);
1788 EXPORT_SYMBOL(mem_cgroup_end_page_stat
);
1791 * size of first charge trial. "32" comes from vmscan.c's magic value.
1792 * TODO: maybe necessary to use big numbers in big irons.
1794 #define CHARGE_BATCH 32U
1795 struct memcg_stock_pcp
{
1796 struct mem_cgroup
*cached
; /* this never be root cgroup */
1797 unsigned int nr_pages
;
1798 struct work_struct work
;
1799 unsigned long flags
;
1800 #define FLUSHING_CACHED_CHARGE 0
1802 static DEFINE_PER_CPU(struct memcg_stock_pcp
, memcg_stock
);
1803 static DEFINE_MUTEX(percpu_charge_mutex
);
1806 * consume_stock: Try to consume stocked charge on this cpu.
1807 * @memcg: memcg to consume from.
1808 * @nr_pages: how many pages to charge.
1810 * The charges will only happen if @memcg matches the current cpu's memcg
1811 * stock, and at least @nr_pages are available in that stock. Failure to
1812 * service an allocation will refill the stock.
1814 * returns true if successful, false otherwise.
1816 static bool consume_stock(struct mem_cgroup
*memcg
, unsigned int nr_pages
)
1818 struct memcg_stock_pcp
*stock
;
1821 if (nr_pages
> CHARGE_BATCH
)
1824 stock
= &get_cpu_var(memcg_stock
);
1825 if (memcg
== stock
->cached
&& stock
->nr_pages
>= nr_pages
) {
1826 stock
->nr_pages
-= nr_pages
;
1829 put_cpu_var(memcg_stock
);
1834 * Returns stocks cached in percpu and reset cached information.
1836 static void drain_stock(struct memcg_stock_pcp
*stock
)
1838 struct mem_cgroup
*old
= stock
->cached
;
1840 if (stock
->nr_pages
) {
1841 page_counter_uncharge(&old
->memory
, stock
->nr_pages
);
1842 if (do_memsw_account())
1843 page_counter_uncharge(&old
->memsw
, stock
->nr_pages
);
1844 css_put_many(&old
->css
, stock
->nr_pages
);
1845 stock
->nr_pages
= 0;
1847 stock
->cached
= NULL
;
1851 * This must be called under preempt disabled or must be called by
1852 * a thread which is pinned to local cpu.
1854 static void drain_local_stock(struct work_struct
*dummy
)
1856 struct memcg_stock_pcp
*stock
= this_cpu_ptr(&memcg_stock
);
1858 clear_bit(FLUSHING_CACHED_CHARGE
, &stock
->flags
);
1862 * Cache charges(val) to local per_cpu area.
1863 * This will be consumed by consume_stock() function, later.
1865 static void refill_stock(struct mem_cgroup
*memcg
, unsigned int nr_pages
)
1867 struct memcg_stock_pcp
*stock
= &get_cpu_var(memcg_stock
);
1869 if (stock
->cached
!= memcg
) { /* reset if necessary */
1871 stock
->cached
= memcg
;
1873 stock
->nr_pages
+= nr_pages
;
1874 put_cpu_var(memcg_stock
);
1878 * Drains all per-CPU charge caches for given root_memcg resp. subtree
1879 * of the hierarchy under it.
1881 static void drain_all_stock(struct mem_cgroup
*root_memcg
)
1885 /* If someone's already draining, avoid adding running more workers. */
1886 if (!mutex_trylock(&percpu_charge_mutex
))
1888 /* Notify other cpus that system-wide "drain" is running */
1891 for_each_online_cpu(cpu
) {
1892 struct memcg_stock_pcp
*stock
= &per_cpu(memcg_stock
, cpu
);
1893 struct mem_cgroup
*memcg
;
1895 memcg
= stock
->cached
;
1896 if (!memcg
|| !stock
->nr_pages
)
1898 if (!mem_cgroup_is_descendant(memcg
, root_memcg
))
1900 if (!test_and_set_bit(FLUSHING_CACHED_CHARGE
, &stock
->flags
)) {
1902 drain_local_stock(&stock
->work
);
1904 schedule_work_on(cpu
, &stock
->work
);
1909 mutex_unlock(&percpu_charge_mutex
);
1912 static int memcg_cpu_hotplug_callback(struct notifier_block
*nb
,
1913 unsigned long action
,
1916 int cpu
= (unsigned long)hcpu
;
1917 struct memcg_stock_pcp
*stock
;
1919 if (action
== CPU_ONLINE
)
1922 if (action
!= CPU_DEAD
&& action
!= CPU_DEAD_FROZEN
)
1925 stock
= &per_cpu(memcg_stock
, cpu
);
1930 static void reclaim_high(struct mem_cgroup
*memcg
,
1931 unsigned int nr_pages
,
1935 if (page_counter_read(&memcg
->memory
) <= memcg
->high
)
1937 mem_cgroup_events(memcg
, MEMCG_HIGH
, 1);
1938 try_to_free_mem_cgroup_pages(memcg
, nr_pages
, gfp_mask
, true);
1939 } while ((memcg
= parent_mem_cgroup(memcg
)));
1942 static void high_work_func(struct work_struct
*work
)
1944 struct mem_cgroup
*memcg
;
1946 memcg
= container_of(work
, struct mem_cgroup
, high_work
);
1947 reclaim_high(memcg
, CHARGE_BATCH
, GFP_KERNEL
);
1951 * Scheduled by try_charge() to be executed from the userland return path
1952 * and reclaims memory over the high limit.
1954 void mem_cgroup_handle_over_high(void)
1956 unsigned int nr_pages
= current
->memcg_nr_pages_over_high
;
1957 struct mem_cgroup
*memcg
;
1959 if (likely(!nr_pages
))
1962 memcg
= get_mem_cgroup_from_mm(current
->mm
);
1963 reclaim_high(memcg
, nr_pages
, GFP_KERNEL
);
1964 css_put(&memcg
->css
);
1965 current
->memcg_nr_pages_over_high
= 0;
1968 static int try_charge(struct mem_cgroup
*memcg
, gfp_t gfp_mask
,
1969 unsigned int nr_pages
)
1971 unsigned int batch
= max(CHARGE_BATCH
, nr_pages
);
1972 int nr_retries
= MEM_CGROUP_RECLAIM_RETRIES
;
1973 struct mem_cgroup
*mem_over_limit
;
1974 struct page_counter
*counter
;
1975 unsigned long nr_reclaimed
;
1976 bool may_swap
= true;
1977 bool drained
= false;
1979 if (mem_cgroup_is_root(memcg
))
1982 if (consume_stock(memcg
, nr_pages
))
1985 if (!do_memsw_account() ||
1986 page_counter_try_charge(&memcg
->memsw
, batch
, &counter
)) {
1987 if (page_counter_try_charge(&memcg
->memory
, batch
, &counter
))
1989 if (do_memsw_account())
1990 page_counter_uncharge(&memcg
->memsw
, batch
);
1991 mem_over_limit
= mem_cgroup_from_counter(counter
, memory
);
1993 mem_over_limit
= mem_cgroup_from_counter(counter
, memsw
);
1997 if (batch
> nr_pages
) {
2003 * Unlike in global OOM situations, memcg is not in a physical
2004 * memory shortage. Allow dying and OOM-killed tasks to
2005 * bypass the last charges so that they can exit quickly and
2006 * free their memory.
2008 if (unlikely(test_thread_flag(TIF_MEMDIE
) ||
2009 fatal_signal_pending(current
) ||
2010 current
->flags
& PF_EXITING
))
2013 if (unlikely(task_in_memcg_oom(current
)))
2016 if (!gfpflags_allow_blocking(gfp_mask
))
2019 mem_cgroup_events(mem_over_limit
, MEMCG_MAX
, 1);
2021 nr_reclaimed
= try_to_free_mem_cgroup_pages(mem_over_limit
, nr_pages
,
2022 gfp_mask
, may_swap
);
2024 if (mem_cgroup_margin(mem_over_limit
) >= nr_pages
)
2028 drain_all_stock(mem_over_limit
);
2033 if (gfp_mask
& __GFP_NORETRY
)
2036 * Even though the limit is exceeded at this point, reclaim
2037 * may have been able to free some pages. Retry the charge
2038 * before killing the task.
2040 * Only for regular pages, though: huge pages are rather
2041 * unlikely to succeed so close to the limit, and we fall back
2042 * to regular pages anyway in case of failure.
2044 if (nr_reclaimed
&& nr_pages
<= (1 << PAGE_ALLOC_COSTLY_ORDER
))
2047 * At task move, charge accounts can be doubly counted. So, it's
2048 * better to wait until the end of task_move if something is going on.
2050 if (mem_cgroup_wait_acct_move(mem_over_limit
))
2056 if (gfp_mask
& __GFP_NOFAIL
)
2059 if (fatal_signal_pending(current
))
2062 mem_cgroup_events(mem_over_limit
, MEMCG_OOM
, 1);
2064 mem_cgroup_oom(mem_over_limit
, gfp_mask
,
2065 get_order(nr_pages
* PAGE_SIZE
));
2067 if (!(gfp_mask
& __GFP_NOFAIL
))
2071 * The allocation either can't fail or will lead to more memory
2072 * being freed very soon. Allow memory usage go over the limit
2073 * temporarily by force charging it.
2075 page_counter_charge(&memcg
->memory
, nr_pages
);
2076 if (do_memsw_account())
2077 page_counter_charge(&memcg
->memsw
, nr_pages
);
2078 css_get_many(&memcg
->css
, nr_pages
);
2083 css_get_many(&memcg
->css
, batch
);
2084 if (batch
> nr_pages
)
2085 refill_stock(memcg
, batch
- nr_pages
);
2088 * If the hierarchy is above the normal consumption range, schedule
2089 * reclaim on returning to userland. We can perform reclaim here
2090 * if __GFP_RECLAIM but let's always punt for simplicity and so that
2091 * GFP_KERNEL can consistently be used during reclaim. @memcg is
2092 * not recorded as it most likely matches current's and won't
2093 * change in the meantime. As high limit is checked again before
2094 * reclaim, the cost of mismatch is negligible.
2097 if (page_counter_read(&memcg
->memory
) > memcg
->high
) {
2098 /* Don't bother a random interrupted task */
2099 if (in_interrupt()) {
2100 schedule_work(&memcg
->high_work
);
2103 current
->memcg_nr_pages_over_high
+= batch
;
2104 set_notify_resume(current
);
2107 } while ((memcg
= parent_mem_cgroup(memcg
)));
2112 static void cancel_charge(struct mem_cgroup
*memcg
, unsigned int nr_pages
)
2114 if (mem_cgroup_is_root(memcg
))
2117 page_counter_uncharge(&memcg
->memory
, nr_pages
);
2118 if (do_memsw_account())
2119 page_counter_uncharge(&memcg
->memsw
, nr_pages
);
2121 css_put_many(&memcg
->css
, nr_pages
);
2124 static void lock_page_lru(struct page
*page
, int *isolated
)
2126 struct zone
*zone
= page_zone(page
);
2128 spin_lock_irq(&zone
->lru_lock
);
2129 if (PageLRU(page
)) {
2130 struct lruvec
*lruvec
;
2132 lruvec
= mem_cgroup_page_lruvec(page
, zone
);
2134 del_page_from_lru_list(page
, lruvec
, page_lru(page
));
2140 static void unlock_page_lru(struct page
*page
, int isolated
)
2142 struct zone
*zone
= page_zone(page
);
2145 struct lruvec
*lruvec
;
2147 lruvec
= mem_cgroup_page_lruvec(page
, zone
);
2148 VM_BUG_ON_PAGE(PageLRU(page
), page
);
2150 add_page_to_lru_list(page
, lruvec
, page_lru(page
));
2152 spin_unlock_irq(&zone
->lru_lock
);
2155 static void commit_charge(struct page
*page
, struct mem_cgroup
*memcg
,
2160 VM_BUG_ON_PAGE(page
->mem_cgroup
, page
);
2163 * In some cases, SwapCache and FUSE(splice_buf->radixtree), the page
2164 * may already be on some other mem_cgroup's LRU. Take care of it.
2167 lock_page_lru(page
, &isolated
);
2170 * Nobody should be changing or seriously looking at
2171 * page->mem_cgroup at this point:
2173 * - the page is uncharged
2175 * - the page is off-LRU
2177 * - an anonymous fault has exclusive page access, except for
2178 * a locked page table
2180 * - a page cache insertion, a swapin fault, or a migration
2181 * have the page locked
2183 page
->mem_cgroup
= memcg
;
2186 unlock_page_lru(page
, isolated
);
2190 static int memcg_alloc_cache_id(void)
2195 id
= ida_simple_get(&memcg_cache_ida
,
2196 0, MEMCG_CACHES_MAX_SIZE
, GFP_KERNEL
);
2200 if (id
< memcg_nr_cache_ids
)
2204 * There's no space for the new id in memcg_caches arrays,
2205 * so we have to grow them.
2207 down_write(&memcg_cache_ids_sem
);
2209 size
= 2 * (id
+ 1);
2210 if (size
< MEMCG_CACHES_MIN_SIZE
)
2211 size
= MEMCG_CACHES_MIN_SIZE
;
2212 else if (size
> MEMCG_CACHES_MAX_SIZE
)
2213 size
= MEMCG_CACHES_MAX_SIZE
;
2215 err
= memcg_update_all_caches(size
);
2217 err
= memcg_update_all_list_lrus(size
);
2219 memcg_nr_cache_ids
= size
;
2221 up_write(&memcg_cache_ids_sem
);
2224 ida_simple_remove(&memcg_cache_ida
, id
);
2230 static void memcg_free_cache_id(int id
)
2232 ida_simple_remove(&memcg_cache_ida
, id
);
2235 struct memcg_kmem_cache_create_work
{
2236 struct mem_cgroup
*memcg
;
2237 struct kmem_cache
*cachep
;
2238 struct work_struct work
;
2241 static void memcg_kmem_cache_create_func(struct work_struct
*w
)
2243 struct memcg_kmem_cache_create_work
*cw
=
2244 container_of(w
, struct memcg_kmem_cache_create_work
, work
);
2245 struct mem_cgroup
*memcg
= cw
->memcg
;
2246 struct kmem_cache
*cachep
= cw
->cachep
;
2248 memcg_create_kmem_cache(memcg
, cachep
);
2250 css_put(&memcg
->css
);
2255 * Enqueue the creation of a per-memcg kmem_cache.
2257 static void __memcg_schedule_kmem_cache_create(struct mem_cgroup
*memcg
,
2258 struct kmem_cache
*cachep
)
2260 struct memcg_kmem_cache_create_work
*cw
;
2262 cw
= kmalloc(sizeof(*cw
), GFP_NOWAIT
);
2266 css_get(&memcg
->css
);
2269 cw
->cachep
= cachep
;
2270 INIT_WORK(&cw
->work
, memcg_kmem_cache_create_func
);
2272 schedule_work(&cw
->work
);
2275 static void memcg_schedule_kmem_cache_create(struct mem_cgroup
*memcg
,
2276 struct kmem_cache
*cachep
)
2279 * We need to stop accounting when we kmalloc, because if the
2280 * corresponding kmalloc cache is not yet created, the first allocation
2281 * in __memcg_schedule_kmem_cache_create will recurse.
2283 * However, it is better to enclose the whole function. Depending on
2284 * the debugging options enabled, INIT_WORK(), for instance, can
2285 * trigger an allocation. This too, will make us recurse. Because at
2286 * this point we can't allow ourselves back into memcg_kmem_get_cache,
2287 * the safest choice is to do it like this, wrapping the whole function.
2289 current
->memcg_kmem_skip_account
= 1;
2290 __memcg_schedule_kmem_cache_create(memcg
, cachep
);
2291 current
->memcg_kmem_skip_account
= 0;
2295 * Return the kmem_cache we're supposed to use for a slab allocation.
2296 * We try to use the current memcg's version of the cache.
2298 * If the cache does not exist yet, if we are the first user of it,
2299 * we either create it immediately, if possible, or create it asynchronously
2301 * In the latter case, we will let the current allocation go through with
2302 * the original cache.
2304 * Can't be called in interrupt context or from kernel threads.
2305 * This function needs to be called with rcu_read_lock() held.
2307 struct kmem_cache
*__memcg_kmem_get_cache(struct kmem_cache
*cachep
, gfp_t gfp
)
2309 struct mem_cgroup
*memcg
;
2310 struct kmem_cache
*memcg_cachep
;
2313 VM_BUG_ON(!is_root_cache(cachep
));
2315 if (cachep
->flags
& SLAB_ACCOUNT
)
2316 gfp
|= __GFP_ACCOUNT
;
2318 if (!(gfp
& __GFP_ACCOUNT
))
2321 if (current
->memcg_kmem_skip_account
)
2324 memcg
= get_mem_cgroup_from_mm(current
->mm
);
2325 kmemcg_id
= READ_ONCE(memcg
->kmemcg_id
);
2329 memcg_cachep
= cache_from_memcg_idx(cachep
, kmemcg_id
);
2330 if (likely(memcg_cachep
))
2331 return memcg_cachep
;
2334 * If we are in a safe context (can wait, and not in interrupt
2335 * context), we could be be predictable and return right away.
2336 * This would guarantee that the allocation being performed
2337 * already belongs in the new cache.
2339 * However, there are some clashes that can arrive from locking.
2340 * For instance, because we acquire the slab_mutex while doing
2341 * memcg_create_kmem_cache, this means no further allocation
2342 * could happen with the slab_mutex held. So it's better to
2345 memcg_schedule_kmem_cache_create(memcg
, cachep
);
2347 css_put(&memcg
->css
);
2351 void __memcg_kmem_put_cache(struct kmem_cache
*cachep
)
2353 if (!is_root_cache(cachep
))
2354 css_put(&cachep
->memcg_params
.memcg
->css
);
2357 int __memcg_kmem_charge_memcg(struct page
*page
, gfp_t gfp
, int order
,
2358 struct mem_cgroup
*memcg
)
2360 unsigned int nr_pages
= 1 << order
;
2361 struct page_counter
*counter
;
2364 if (!memcg_kmem_online(memcg
))
2367 ret
= try_charge(memcg
, gfp
, nr_pages
);
2371 if (!cgroup_subsys_on_dfl(memory_cgrp_subsys
) &&
2372 !page_counter_try_charge(&memcg
->kmem
, nr_pages
, &counter
)) {
2373 cancel_charge(memcg
, nr_pages
);
2377 page
->mem_cgroup
= memcg
;
2382 int __memcg_kmem_charge(struct page
*page
, gfp_t gfp
, int order
)
2384 struct mem_cgroup
*memcg
;
2387 memcg
= get_mem_cgroup_from_mm(current
->mm
);
2388 ret
= __memcg_kmem_charge_memcg(page
, gfp
, order
, memcg
);
2389 css_put(&memcg
->css
);
2393 void __memcg_kmem_uncharge(struct page
*page
, int order
)
2395 struct mem_cgroup
*memcg
= page
->mem_cgroup
;
2396 unsigned int nr_pages
= 1 << order
;
2401 VM_BUG_ON_PAGE(mem_cgroup_is_root(memcg
), page
);
2403 if (!cgroup_subsys_on_dfl(memory_cgrp_subsys
))
2404 page_counter_uncharge(&memcg
->kmem
, nr_pages
);
2406 page_counter_uncharge(&memcg
->memory
, nr_pages
);
2407 if (do_memsw_account())
2408 page_counter_uncharge(&memcg
->memsw
, nr_pages
);
2410 page
->mem_cgroup
= NULL
;
2411 css_put_many(&memcg
->css
, nr_pages
);
2413 #endif /* !CONFIG_SLOB */
2415 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
2418 * Because tail pages are not marked as "used", set it. We're under
2419 * zone->lru_lock and migration entries setup in all page mappings.
2421 void mem_cgroup_split_huge_fixup(struct page
*head
)
2425 if (mem_cgroup_disabled())
2428 for (i
= 1; i
< HPAGE_PMD_NR
; i
++)
2429 head
[i
].mem_cgroup
= head
->mem_cgroup
;
2431 __this_cpu_sub(head
->mem_cgroup
->stat
->count
[MEM_CGROUP_STAT_RSS_HUGE
],
2434 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
2436 #ifdef CONFIG_MEMCG_SWAP
2437 static void mem_cgroup_swap_statistics(struct mem_cgroup
*memcg
,
2440 int val
= (charge
) ? 1 : -1;
2441 this_cpu_add(memcg
->stat
->count
[MEM_CGROUP_STAT_SWAP
], val
);
2445 * mem_cgroup_move_swap_account - move swap charge and swap_cgroup's record.
2446 * @entry: swap entry to be moved
2447 * @from: mem_cgroup which the entry is moved from
2448 * @to: mem_cgroup which the entry is moved to
2450 * It succeeds only when the swap_cgroup's record for this entry is the same
2451 * as the mem_cgroup's id of @from.
2453 * Returns 0 on success, -EINVAL on failure.
2455 * The caller must have charged to @to, IOW, called page_counter_charge() about
2456 * both res and memsw, and called css_get().
2458 static int mem_cgroup_move_swap_account(swp_entry_t entry
,
2459 struct mem_cgroup
*from
, struct mem_cgroup
*to
)
2461 unsigned short old_id
, new_id
;
2463 old_id
= mem_cgroup_id(from
);
2464 new_id
= mem_cgroup_id(to
);
2466 if (swap_cgroup_cmpxchg(entry
, old_id
, new_id
) == old_id
) {
2467 mem_cgroup_swap_statistics(from
, false);
2468 mem_cgroup_swap_statistics(to
, true);
2474 static inline int mem_cgroup_move_swap_account(swp_entry_t entry
,
2475 struct mem_cgroup
*from
, struct mem_cgroup
*to
)
2481 static DEFINE_MUTEX(memcg_limit_mutex
);
2483 static int mem_cgroup_resize_limit(struct mem_cgroup
*memcg
,
2484 unsigned long limit
)
2486 unsigned long curusage
;
2487 unsigned long oldusage
;
2488 bool enlarge
= false;
2493 * For keeping hierarchical_reclaim simple, how long we should retry
2494 * is depends on callers. We set our retry-count to be function
2495 * of # of children which we should visit in this loop.
2497 retry_count
= MEM_CGROUP_RECLAIM_RETRIES
*
2498 mem_cgroup_count_children(memcg
);
2500 oldusage
= page_counter_read(&memcg
->memory
);
2503 if (signal_pending(current
)) {
2508 mutex_lock(&memcg_limit_mutex
);
2509 if (limit
> memcg
->memsw
.limit
) {
2510 mutex_unlock(&memcg_limit_mutex
);
2514 if (limit
> memcg
->memory
.limit
)
2516 ret
= page_counter_limit(&memcg
->memory
, limit
);
2517 mutex_unlock(&memcg_limit_mutex
);
2522 try_to_free_mem_cgroup_pages(memcg
, 1, GFP_KERNEL
, true);
2524 curusage
= page_counter_read(&memcg
->memory
);
2525 /* Usage is reduced ? */
2526 if (curusage
>= oldusage
)
2529 oldusage
= curusage
;
2530 } while (retry_count
);
2532 if (!ret
&& enlarge
)
2533 memcg_oom_recover(memcg
);
2538 static int mem_cgroup_resize_memsw_limit(struct mem_cgroup
*memcg
,
2539 unsigned long limit
)
2541 unsigned long curusage
;
2542 unsigned long oldusage
;
2543 bool enlarge
= false;
2547 /* see mem_cgroup_resize_res_limit */
2548 retry_count
= MEM_CGROUP_RECLAIM_RETRIES
*
2549 mem_cgroup_count_children(memcg
);
2551 oldusage
= page_counter_read(&memcg
->memsw
);
2554 if (signal_pending(current
)) {
2559 mutex_lock(&memcg_limit_mutex
);
2560 if (limit
< memcg
->memory
.limit
) {
2561 mutex_unlock(&memcg_limit_mutex
);
2565 if (limit
> memcg
->memsw
.limit
)
2567 ret
= page_counter_limit(&memcg
->memsw
, limit
);
2568 mutex_unlock(&memcg_limit_mutex
);
2573 try_to_free_mem_cgroup_pages(memcg
, 1, GFP_KERNEL
, false);
2575 curusage
= page_counter_read(&memcg
->memsw
);
2576 /* Usage is reduced ? */
2577 if (curusage
>= oldusage
)
2580 oldusage
= curusage
;
2581 } while (retry_count
);
2583 if (!ret
&& enlarge
)
2584 memcg_oom_recover(memcg
);
2589 unsigned long mem_cgroup_soft_limit_reclaim(struct zone
*zone
, int order
,
2591 unsigned long *total_scanned
)
2593 unsigned long nr_reclaimed
= 0;
2594 struct mem_cgroup_per_zone
*mz
, *next_mz
= NULL
;
2595 unsigned long reclaimed
;
2597 struct mem_cgroup_tree_per_zone
*mctz
;
2598 unsigned long excess
;
2599 unsigned long nr_scanned
;
2604 mctz
= soft_limit_tree_node_zone(zone_to_nid(zone
), zone_idx(zone
));
2606 * This loop can run a while, specially if mem_cgroup's continuously
2607 * keep exceeding their soft limit and putting the system under
2614 mz
= mem_cgroup_largest_soft_limit_node(mctz
);
2619 reclaimed
= mem_cgroup_soft_reclaim(mz
->memcg
, zone
,
2620 gfp_mask
, &nr_scanned
);
2621 nr_reclaimed
+= reclaimed
;
2622 *total_scanned
+= nr_scanned
;
2623 spin_lock_irq(&mctz
->lock
);
2624 __mem_cgroup_remove_exceeded(mz
, mctz
);
2627 * If we failed to reclaim anything from this memory cgroup
2628 * it is time to move on to the next cgroup
2632 next_mz
= __mem_cgroup_largest_soft_limit_node(mctz
);
2634 excess
= soft_limit_excess(mz
->memcg
);
2636 * One school of thought says that we should not add
2637 * back the node to the tree if reclaim returns 0.
2638 * But our reclaim could return 0, simply because due
2639 * to priority we are exposing a smaller subset of
2640 * memory to reclaim from. Consider this as a longer
2643 /* If excess == 0, no tree ops */
2644 __mem_cgroup_insert_exceeded(mz
, mctz
, excess
);
2645 spin_unlock_irq(&mctz
->lock
);
2646 css_put(&mz
->memcg
->css
);
2649 * Could not reclaim anything and there are no more
2650 * mem cgroups to try or we seem to be looping without
2651 * reclaiming anything.
2653 if (!nr_reclaimed
&&
2655 loop
> MEM_CGROUP_MAX_SOFT_LIMIT_RECLAIM_LOOPS
))
2657 } while (!nr_reclaimed
);
2659 css_put(&next_mz
->memcg
->css
);
2660 return nr_reclaimed
;
2664 * Test whether @memcg has children, dead or alive. Note that this
2665 * function doesn't care whether @memcg has use_hierarchy enabled and
2666 * returns %true if there are child csses according to the cgroup
2667 * hierarchy. Testing use_hierarchy is the caller's responsiblity.
2669 static inline bool memcg_has_children(struct mem_cgroup
*memcg
)
2674 ret
= css_next_child(NULL
, &memcg
->css
);
2680 * Reclaims as many pages from the given memcg as possible and moves
2681 * the rest to the parent.
2683 * Caller is responsible for holding css reference for memcg.
2685 static int mem_cgroup_force_empty(struct mem_cgroup
*memcg
)
2687 int nr_retries
= MEM_CGROUP_RECLAIM_RETRIES
;
2689 /* we call try-to-free pages for make this cgroup empty */
2690 lru_add_drain_all();
2691 /* try to free all pages in this cgroup */
2692 while (nr_retries
&& page_counter_read(&memcg
->memory
)) {
2695 if (signal_pending(current
))
2698 progress
= try_to_free_mem_cgroup_pages(memcg
, 1,
2702 /* maybe some writeback is necessary */
2703 congestion_wait(BLK_RW_ASYNC
, HZ
/10);
2711 static ssize_t
mem_cgroup_force_empty_write(struct kernfs_open_file
*of
,
2712 char *buf
, size_t nbytes
,
2715 struct mem_cgroup
*memcg
= mem_cgroup_from_css(of_css(of
));
2717 if (mem_cgroup_is_root(memcg
))
2719 return mem_cgroup_force_empty(memcg
) ?: nbytes
;
2722 static u64
mem_cgroup_hierarchy_read(struct cgroup_subsys_state
*css
,
2725 return mem_cgroup_from_css(css
)->use_hierarchy
;
2728 static int mem_cgroup_hierarchy_write(struct cgroup_subsys_state
*css
,
2729 struct cftype
*cft
, u64 val
)
2732 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
2733 struct mem_cgroup
*parent_memcg
= mem_cgroup_from_css(memcg
->css
.parent
);
2735 if (memcg
->use_hierarchy
== val
)
2739 * If parent's use_hierarchy is set, we can't make any modifications
2740 * in the child subtrees. If it is unset, then the change can
2741 * occur, provided the current cgroup has no children.
2743 * For the root cgroup, parent_mem is NULL, we allow value to be
2744 * set if there are no children.
2746 if ((!parent_memcg
|| !parent_memcg
->use_hierarchy
) &&
2747 (val
== 1 || val
== 0)) {
2748 if (!memcg_has_children(memcg
))
2749 memcg
->use_hierarchy
= val
;
2758 static unsigned long tree_stat(struct mem_cgroup
*memcg
,
2759 enum mem_cgroup_stat_index idx
)
2761 struct mem_cgroup
*iter
;
2762 unsigned long val
= 0;
2764 for_each_mem_cgroup_tree(iter
, memcg
)
2765 val
+= mem_cgroup_read_stat(iter
, idx
);
2770 static unsigned long mem_cgroup_usage(struct mem_cgroup
*memcg
, bool swap
)
2774 if (mem_cgroup_is_root(memcg
)) {
2775 val
= tree_stat(memcg
, MEM_CGROUP_STAT_CACHE
);
2776 val
+= tree_stat(memcg
, MEM_CGROUP_STAT_RSS
);
2778 val
+= tree_stat(memcg
, 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 BUG_ON(memcg
->kmemcg_id
>= 0);
2845 BUG_ON(memcg
->kmem_state
);
2847 memcg_id
= memcg_alloc_cache_id();
2851 static_branch_inc(&memcg_kmem_enabled_key
);
2853 * A memory cgroup is considered kmem-online as soon as it gets
2854 * kmemcg_id. Setting the id after enabling static branching will
2855 * guarantee no one starts accounting before all call sites are
2858 memcg
->kmemcg_id
= memcg_id
;
2859 memcg
->kmem_state
= KMEM_ONLINE
;
2864 static int memcg_propagate_kmem(struct mem_cgroup
*parent
,
2865 struct mem_cgroup
*memcg
)
2869 mutex_lock(&memcg_limit_mutex
);
2871 * If the parent cgroup is not kmem-online now, it cannot be
2872 * onlined after this point, because it has at least one child
2875 if (memcg_kmem_online(parent
) ||
2876 (cgroup_subsys_on_dfl(memory_cgrp_subsys
) && !cgroup_memory_nokmem
))
2877 ret
= memcg_online_kmem(memcg
);
2878 mutex_unlock(&memcg_limit_mutex
);
2882 static void memcg_offline_kmem(struct mem_cgroup
*memcg
)
2884 struct cgroup_subsys_state
*css
;
2885 struct mem_cgroup
*parent
, *child
;
2888 if (memcg
->kmem_state
!= KMEM_ONLINE
)
2891 * Clear the online state before clearing memcg_caches array
2892 * entries. The slab_mutex in memcg_deactivate_kmem_caches()
2893 * guarantees that no cache will be created for this cgroup
2894 * after we are done (see memcg_create_kmem_cache()).
2896 memcg
->kmem_state
= KMEM_ALLOCATED
;
2898 memcg_deactivate_kmem_caches(memcg
);
2900 kmemcg_id
= memcg
->kmemcg_id
;
2901 BUG_ON(kmemcg_id
< 0);
2903 parent
= parent_mem_cgroup(memcg
);
2905 parent
= root_mem_cgroup
;
2908 * Change kmemcg_id of this cgroup and all its descendants to the
2909 * parent's id, and then move all entries from this cgroup's list_lrus
2910 * to ones of the parent. After we have finished, all list_lrus
2911 * corresponding to this cgroup are guaranteed to remain empty. The
2912 * ordering is imposed by list_lru_node->lock taken by
2913 * memcg_drain_all_list_lrus().
2915 css_for_each_descendant_pre(css
, &memcg
->css
) {
2916 child
= mem_cgroup_from_css(css
);
2917 BUG_ON(child
->kmemcg_id
!= kmemcg_id
);
2918 child
->kmemcg_id
= parent
->kmemcg_id
;
2919 if (!memcg
->use_hierarchy
)
2922 memcg_drain_all_list_lrus(kmemcg_id
, parent
->kmemcg_id
);
2924 memcg_free_cache_id(kmemcg_id
);
2927 static void memcg_free_kmem(struct mem_cgroup
*memcg
)
2929 /* css_alloc() failed, offlining didn't happen */
2930 if (unlikely(memcg
->kmem_state
== KMEM_ONLINE
))
2931 memcg_offline_kmem(memcg
);
2933 if (memcg
->kmem_state
== KMEM_ALLOCATED
) {
2934 memcg_destroy_kmem_caches(memcg
);
2935 static_branch_dec(&memcg_kmem_enabled_key
);
2936 WARN_ON(page_counter_read(&memcg
->kmem
));
2940 static int memcg_propagate_kmem(struct mem_cgroup
*parent
, struct mem_cgroup
*memcg
)
2944 static int memcg_online_kmem(struct mem_cgroup
*memcg
)
2948 static void memcg_offline_kmem(struct mem_cgroup
*memcg
)
2951 static void memcg_free_kmem(struct mem_cgroup
*memcg
)
2954 #endif /* !CONFIG_SLOB */
2956 static int memcg_update_kmem_limit(struct mem_cgroup
*memcg
,
2957 unsigned long limit
)
2961 mutex_lock(&memcg_limit_mutex
);
2962 /* Top-level cgroup doesn't propagate from root */
2963 if (!memcg_kmem_online(memcg
)) {
2964 if (cgroup_is_populated(memcg
->css
.cgroup
) ||
2965 (memcg
->use_hierarchy
&& memcg_has_children(memcg
)))
2969 ret
= memcg_online_kmem(memcg
);
2973 ret
= page_counter_limit(&memcg
->kmem
, limit
);
2975 mutex_unlock(&memcg_limit_mutex
);
2979 static int memcg_update_tcp_limit(struct mem_cgroup
*memcg
, unsigned long limit
)
2983 mutex_lock(&memcg_limit_mutex
);
2985 ret
= page_counter_limit(&memcg
->tcpmem
, limit
);
2989 if (!memcg
->tcpmem_active
) {
2991 * The active flag needs to be written after the static_key
2992 * update. This is what guarantees that the socket activation
2993 * function is the last one to run. See sock_update_memcg() for
2994 * details, and note that we don't mark any socket as belonging
2995 * to this memcg until that flag is up.
2997 * We need to do this, because static_keys will span multiple
2998 * sites, but we can't control their order. If we mark a socket
2999 * as accounted, but the accounting functions are not patched in
3000 * yet, we'll lose accounting.
3002 * We never race with the readers in sock_update_memcg(),
3003 * because when this value change, the code to process it is not
3006 static_branch_inc(&memcg_sockets_enabled_key
);
3007 memcg
->tcpmem_active
= true;
3010 mutex_unlock(&memcg_limit_mutex
);
3015 * The user of this function is...
3018 static ssize_t
mem_cgroup_write(struct kernfs_open_file
*of
,
3019 char *buf
, size_t nbytes
, loff_t off
)
3021 struct mem_cgroup
*memcg
= mem_cgroup_from_css(of_css(of
));
3022 unsigned long nr_pages
;
3025 buf
= strstrip(buf
);
3026 ret
= page_counter_memparse(buf
, "-1", &nr_pages
);
3030 switch (MEMFILE_ATTR(of_cft(of
)->private)) {
3032 if (mem_cgroup_is_root(memcg
)) { /* Can't set limit on root */
3036 switch (MEMFILE_TYPE(of_cft(of
)->private)) {
3038 ret
= mem_cgroup_resize_limit(memcg
, nr_pages
);
3041 ret
= mem_cgroup_resize_memsw_limit(memcg
, nr_pages
);
3044 ret
= memcg_update_kmem_limit(memcg
, nr_pages
);
3047 ret
= memcg_update_tcp_limit(memcg
, nr_pages
);
3051 case RES_SOFT_LIMIT
:
3052 memcg
->soft_limit
= nr_pages
;
3056 return ret
?: nbytes
;
3059 static ssize_t
mem_cgroup_reset(struct kernfs_open_file
*of
, char *buf
,
3060 size_t nbytes
, loff_t off
)
3062 struct mem_cgroup
*memcg
= mem_cgroup_from_css(of_css(of
));
3063 struct page_counter
*counter
;
3065 switch (MEMFILE_TYPE(of_cft(of
)->private)) {
3067 counter
= &memcg
->memory
;
3070 counter
= &memcg
->memsw
;
3073 counter
= &memcg
->kmem
;
3076 counter
= &memcg
->tcpmem
;
3082 switch (MEMFILE_ATTR(of_cft(of
)->private)) {
3084 page_counter_reset_watermark(counter
);
3087 counter
->failcnt
= 0;
3096 static u64
mem_cgroup_move_charge_read(struct cgroup_subsys_state
*css
,
3099 return mem_cgroup_from_css(css
)->move_charge_at_immigrate
;
3103 static int mem_cgroup_move_charge_write(struct cgroup_subsys_state
*css
,
3104 struct cftype
*cft
, u64 val
)
3106 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
3108 if (val
& ~MOVE_MASK
)
3112 * No kind of locking is needed in here, because ->can_attach() will
3113 * check this value once in the beginning of the process, and then carry
3114 * on with stale data. This means that changes to this value will only
3115 * affect task migrations starting after the change.
3117 memcg
->move_charge_at_immigrate
= val
;
3121 static int mem_cgroup_move_charge_write(struct cgroup_subsys_state
*css
,
3122 struct cftype
*cft
, u64 val
)
3129 static int memcg_numa_stat_show(struct seq_file
*m
, void *v
)
3133 unsigned int lru_mask
;
3136 static const struct numa_stat stats
[] = {
3137 { "total", LRU_ALL
},
3138 { "file", LRU_ALL_FILE
},
3139 { "anon", LRU_ALL_ANON
},
3140 { "unevictable", BIT(LRU_UNEVICTABLE
) },
3142 const struct numa_stat
*stat
;
3145 struct mem_cgroup
*memcg
= mem_cgroup_from_css(seq_css(m
));
3147 for (stat
= stats
; stat
< stats
+ ARRAY_SIZE(stats
); stat
++) {
3148 nr
= mem_cgroup_nr_lru_pages(memcg
, stat
->lru_mask
);
3149 seq_printf(m
, "%s=%lu", stat
->name
, nr
);
3150 for_each_node_state(nid
, N_MEMORY
) {
3151 nr
= mem_cgroup_node_nr_lru_pages(memcg
, nid
,
3153 seq_printf(m
, " N%d=%lu", nid
, nr
);
3158 for (stat
= stats
; stat
< stats
+ ARRAY_SIZE(stats
); stat
++) {
3159 struct mem_cgroup
*iter
;
3162 for_each_mem_cgroup_tree(iter
, memcg
)
3163 nr
+= mem_cgroup_nr_lru_pages(iter
, stat
->lru_mask
);
3164 seq_printf(m
, "hierarchical_%s=%lu", stat
->name
, nr
);
3165 for_each_node_state(nid
, N_MEMORY
) {
3167 for_each_mem_cgroup_tree(iter
, memcg
)
3168 nr
+= mem_cgroup_node_nr_lru_pages(
3169 iter
, nid
, stat
->lru_mask
);
3170 seq_printf(m
, " N%d=%lu", nid
, nr
);
3177 #endif /* CONFIG_NUMA */
3179 static int memcg_stat_show(struct seq_file
*m
, void *v
)
3181 struct mem_cgroup
*memcg
= mem_cgroup_from_css(seq_css(m
));
3182 unsigned long memory
, memsw
;
3183 struct mem_cgroup
*mi
;
3186 BUILD_BUG_ON(ARRAY_SIZE(mem_cgroup_stat_names
) !=
3187 MEM_CGROUP_STAT_NSTATS
);
3188 BUILD_BUG_ON(ARRAY_SIZE(mem_cgroup_events_names
) !=
3189 MEM_CGROUP_EVENTS_NSTATS
);
3190 BUILD_BUG_ON(ARRAY_SIZE(mem_cgroup_lru_names
) != NR_LRU_LISTS
);
3192 for (i
= 0; i
< MEM_CGROUP_STAT_NSTATS
; i
++) {
3193 if (i
== MEM_CGROUP_STAT_SWAP
&& !do_memsw_account())
3195 seq_printf(m
, "%s %lu\n", mem_cgroup_stat_names
[i
],
3196 mem_cgroup_read_stat(memcg
, i
) * PAGE_SIZE
);
3199 for (i
= 0; i
< MEM_CGROUP_EVENTS_NSTATS
; i
++)
3200 seq_printf(m
, "%s %lu\n", mem_cgroup_events_names
[i
],
3201 mem_cgroup_read_events(memcg
, i
));
3203 for (i
= 0; i
< NR_LRU_LISTS
; i
++)
3204 seq_printf(m
, "%s %lu\n", mem_cgroup_lru_names
[i
],
3205 mem_cgroup_nr_lru_pages(memcg
, BIT(i
)) * PAGE_SIZE
);
3207 /* Hierarchical information */
3208 memory
= memsw
= PAGE_COUNTER_MAX
;
3209 for (mi
= memcg
; mi
; mi
= parent_mem_cgroup(mi
)) {
3210 memory
= min(memory
, mi
->memory
.limit
);
3211 memsw
= min(memsw
, mi
->memsw
.limit
);
3213 seq_printf(m
, "hierarchical_memory_limit %llu\n",
3214 (u64
)memory
* PAGE_SIZE
);
3215 if (do_memsw_account())
3216 seq_printf(m
, "hierarchical_memsw_limit %llu\n",
3217 (u64
)memsw
* PAGE_SIZE
);
3219 for (i
= 0; i
< MEM_CGROUP_STAT_NSTATS
; i
++) {
3220 unsigned long long val
= 0;
3222 if (i
== MEM_CGROUP_STAT_SWAP
&& !do_memsw_account())
3224 for_each_mem_cgroup_tree(mi
, memcg
)
3225 val
+= mem_cgroup_read_stat(mi
, i
) * PAGE_SIZE
;
3226 seq_printf(m
, "total_%s %llu\n", mem_cgroup_stat_names
[i
], val
);
3229 for (i
= 0; i
< MEM_CGROUP_EVENTS_NSTATS
; i
++) {
3230 unsigned long long val
= 0;
3232 for_each_mem_cgroup_tree(mi
, memcg
)
3233 val
+= mem_cgroup_read_events(mi
, i
);
3234 seq_printf(m
, "total_%s %llu\n",
3235 mem_cgroup_events_names
[i
], val
);
3238 for (i
= 0; i
< NR_LRU_LISTS
; i
++) {
3239 unsigned long long val
= 0;
3241 for_each_mem_cgroup_tree(mi
, memcg
)
3242 val
+= mem_cgroup_nr_lru_pages(mi
, BIT(i
)) * PAGE_SIZE
;
3243 seq_printf(m
, "total_%s %llu\n", mem_cgroup_lru_names
[i
], val
);
3246 #ifdef CONFIG_DEBUG_VM
3249 struct mem_cgroup_per_zone
*mz
;
3250 struct zone_reclaim_stat
*rstat
;
3251 unsigned long recent_rotated
[2] = {0, 0};
3252 unsigned long recent_scanned
[2] = {0, 0};
3254 for_each_online_node(nid
)
3255 for (zid
= 0; zid
< MAX_NR_ZONES
; zid
++) {
3256 mz
= &memcg
->nodeinfo
[nid
]->zoneinfo
[zid
];
3257 rstat
= &mz
->lruvec
.reclaim_stat
;
3259 recent_rotated
[0] += rstat
->recent_rotated
[0];
3260 recent_rotated
[1] += rstat
->recent_rotated
[1];
3261 recent_scanned
[0] += rstat
->recent_scanned
[0];
3262 recent_scanned
[1] += rstat
->recent_scanned
[1];
3264 seq_printf(m
, "recent_rotated_anon %lu\n", recent_rotated
[0]);
3265 seq_printf(m
, "recent_rotated_file %lu\n", recent_rotated
[1]);
3266 seq_printf(m
, "recent_scanned_anon %lu\n", recent_scanned
[0]);
3267 seq_printf(m
, "recent_scanned_file %lu\n", recent_scanned
[1]);
3274 static u64
mem_cgroup_swappiness_read(struct cgroup_subsys_state
*css
,
3277 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
3279 return mem_cgroup_swappiness(memcg
);
3282 static int mem_cgroup_swappiness_write(struct cgroup_subsys_state
*css
,
3283 struct cftype
*cft
, u64 val
)
3285 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
3291 memcg
->swappiness
= val
;
3293 vm_swappiness
= val
;
3298 static void __mem_cgroup_threshold(struct mem_cgroup
*memcg
, bool swap
)
3300 struct mem_cgroup_threshold_ary
*t
;
3301 unsigned long usage
;
3306 t
= rcu_dereference(memcg
->thresholds
.primary
);
3308 t
= rcu_dereference(memcg
->memsw_thresholds
.primary
);
3313 usage
= mem_cgroup_usage(memcg
, swap
);
3316 * current_threshold points to threshold just below or equal to usage.
3317 * If it's not true, a threshold was crossed after last
3318 * call of __mem_cgroup_threshold().
3320 i
= t
->current_threshold
;
3323 * Iterate backward over array of thresholds starting from
3324 * current_threshold and check if a threshold is crossed.
3325 * If none of thresholds below usage is crossed, we read
3326 * only one element of the array here.
3328 for (; i
>= 0 && unlikely(t
->entries
[i
].threshold
> usage
); i
--)
3329 eventfd_signal(t
->entries
[i
].eventfd
, 1);
3331 /* i = current_threshold + 1 */
3335 * Iterate forward over array of thresholds starting from
3336 * current_threshold+1 and check if a threshold is crossed.
3337 * If none of thresholds above usage is crossed, we read
3338 * only one element of the array here.
3340 for (; i
< t
->size
&& unlikely(t
->entries
[i
].threshold
<= usage
); i
++)
3341 eventfd_signal(t
->entries
[i
].eventfd
, 1);
3343 /* Update current_threshold */
3344 t
->current_threshold
= i
- 1;
3349 static void mem_cgroup_threshold(struct mem_cgroup
*memcg
)
3352 __mem_cgroup_threshold(memcg
, false);
3353 if (do_memsw_account())
3354 __mem_cgroup_threshold(memcg
, true);
3356 memcg
= parent_mem_cgroup(memcg
);
3360 static int compare_thresholds(const void *a
, const void *b
)
3362 const struct mem_cgroup_threshold
*_a
= a
;
3363 const struct mem_cgroup_threshold
*_b
= b
;
3365 if (_a
->threshold
> _b
->threshold
)
3368 if (_a
->threshold
< _b
->threshold
)
3374 static int mem_cgroup_oom_notify_cb(struct mem_cgroup
*memcg
)
3376 struct mem_cgroup_eventfd_list
*ev
;
3378 spin_lock(&memcg_oom_lock
);
3380 list_for_each_entry(ev
, &memcg
->oom_notify
, list
)
3381 eventfd_signal(ev
->eventfd
, 1);
3383 spin_unlock(&memcg_oom_lock
);
3387 static void mem_cgroup_oom_notify(struct mem_cgroup
*memcg
)
3389 struct mem_cgroup
*iter
;
3391 for_each_mem_cgroup_tree(iter
, memcg
)
3392 mem_cgroup_oom_notify_cb(iter
);
3395 static int __mem_cgroup_usage_register_event(struct mem_cgroup
*memcg
,
3396 struct eventfd_ctx
*eventfd
, const char *args
, enum res_type type
)
3398 struct mem_cgroup_thresholds
*thresholds
;
3399 struct mem_cgroup_threshold_ary
*new;
3400 unsigned long threshold
;
3401 unsigned long usage
;
3404 ret
= page_counter_memparse(args
, "-1", &threshold
);
3408 mutex_lock(&memcg
->thresholds_lock
);
3411 thresholds
= &memcg
->thresholds
;
3412 usage
= mem_cgroup_usage(memcg
, false);
3413 } else if (type
== _MEMSWAP
) {
3414 thresholds
= &memcg
->memsw_thresholds
;
3415 usage
= mem_cgroup_usage(memcg
, true);
3419 /* Check if a threshold crossed before adding a new one */
3420 if (thresholds
->primary
)
3421 __mem_cgroup_threshold(memcg
, type
== _MEMSWAP
);
3423 size
= thresholds
->primary
? thresholds
->primary
->size
+ 1 : 1;
3425 /* Allocate memory for new array of thresholds */
3426 new = kmalloc(sizeof(*new) + size
* sizeof(struct mem_cgroup_threshold
),
3434 /* Copy thresholds (if any) to new array */
3435 if (thresholds
->primary
) {
3436 memcpy(new->entries
, thresholds
->primary
->entries
, (size
- 1) *
3437 sizeof(struct mem_cgroup_threshold
));
3440 /* Add new threshold */
3441 new->entries
[size
- 1].eventfd
= eventfd
;
3442 new->entries
[size
- 1].threshold
= threshold
;
3444 /* Sort thresholds. Registering of new threshold isn't time-critical */
3445 sort(new->entries
, size
, sizeof(struct mem_cgroup_threshold
),
3446 compare_thresholds
, NULL
);
3448 /* Find current threshold */
3449 new->current_threshold
= -1;
3450 for (i
= 0; i
< size
; i
++) {
3451 if (new->entries
[i
].threshold
<= usage
) {
3453 * new->current_threshold will not be used until
3454 * rcu_assign_pointer(), so it's safe to increment
3457 ++new->current_threshold
;
3462 /* Free old spare buffer and save old primary buffer as spare */
3463 kfree(thresholds
->spare
);
3464 thresholds
->spare
= thresholds
->primary
;
3466 rcu_assign_pointer(thresholds
->primary
, new);
3468 /* To be sure that nobody uses thresholds */
3472 mutex_unlock(&memcg
->thresholds_lock
);
3477 static int mem_cgroup_usage_register_event(struct mem_cgroup
*memcg
,
3478 struct eventfd_ctx
*eventfd
, const char *args
)
3480 return __mem_cgroup_usage_register_event(memcg
, eventfd
, args
, _MEM
);
3483 static int memsw_cgroup_usage_register_event(struct mem_cgroup
*memcg
,
3484 struct eventfd_ctx
*eventfd
, const char *args
)
3486 return __mem_cgroup_usage_register_event(memcg
, eventfd
, args
, _MEMSWAP
);
3489 static void __mem_cgroup_usage_unregister_event(struct mem_cgroup
*memcg
,
3490 struct eventfd_ctx
*eventfd
, enum res_type type
)
3492 struct mem_cgroup_thresholds
*thresholds
;
3493 struct mem_cgroup_threshold_ary
*new;
3494 unsigned long usage
;
3497 mutex_lock(&memcg
->thresholds_lock
);
3500 thresholds
= &memcg
->thresholds
;
3501 usage
= mem_cgroup_usage(memcg
, false);
3502 } else if (type
== _MEMSWAP
) {
3503 thresholds
= &memcg
->memsw_thresholds
;
3504 usage
= mem_cgroup_usage(memcg
, true);
3508 if (!thresholds
->primary
)
3511 /* Check if a threshold crossed before removing */
3512 __mem_cgroup_threshold(memcg
, type
== _MEMSWAP
);
3514 /* Calculate new number of threshold */
3516 for (i
= 0; i
< thresholds
->primary
->size
; i
++) {
3517 if (thresholds
->primary
->entries
[i
].eventfd
!= eventfd
)
3521 new = thresholds
->spare
;
3523 /* Set thresholds array to NULL if we don't have thresholds */
3532 /* Copy thresholds and find current threshold */
3533 new->current_threshold
= -1;
3534 for (i
= 0, j
= 0; i
< thresholds
->primary
->size
; i
++) {
3535 if (thresholds
->primary
->entries
[i
].eventfd
== eventfd
)
3538 new->entries
[j
] = thresholds
->primary
->entries
[i
];
3539 if (new->entries
[j
].threshold
<= usage
) {
3541 * new->current_threshold will not be used
3542 * until rcu_assign_pointer(), so it's safe to increment
3545 ++new->current_threshold
;
3551 /* Swap primary and spare array */
3552 thresholds
->spare
= thresholds
->primary
;
3554 rcu_assign_pointer(thresholds
->primary
, new);
3556 /* To be sure that nobody uses thresholds */
3559 /* If all events are unregistered, free the spare array */
3561 kfree(thresholds
->spare
);
3562 thresholds
->spare
= NULL
;
3565 mutex_unlock(&memcg
->thresholds_lock
);
3568 static void mem_cgroup_usage_unregister_event(struct mem_cgroup
*memcg
,
3569 struct eventfd_ctx
*eventfd
)
3571 return __mem_cgroup_usage_unregister_event(memcg
, eventfd
, _MEM
);
3574 static void memsw_cgroup_usage_unregister_event(struct mem_cgroup
*memcg
,
3575 struct eventfd_ctx
*eventfd
)
3577 return __mem_cgroup_usage_unregister_event(memcg
, eventfd
, _MEMSWAP
);
3580 static int mem_cgroup_oom_register_event(struct mem_cgroup
*memcg
,
3581 struct eventfd_ctx
*eventfd
, const char *args
)
3583 struct mem_cgroup_eventfd_list
*event
;
3585 event
= kmalloc(sizeof(*event
), GFP_KERNEL
);
3589 spin_lock(&memcg_oom_lock
);
3591 event
->eventfd
= eventfd
;
3592 list_add(&event
->list
, &memcg
->oom_notify
);
3594 /* already in OOM ? */
3595 if (memcg
->under_oom
)
3596 eventfd_signal(eventfd
, 1);
3597 spin_unlock(&memcg_oom_lock
);
3602 static void mem_cgroup_oom_unregister_event(struct mem_cgroup
*memcg
,
3603 struct eventfd_ctx
*eventfd
)
3605 struct mem_cgroup_eventfd_list
*ev
, *tmp
;
3607 spin_lock(&memcg_oom_lock
);
3609 list_for_each_entry_safe(ev
, tmp
, &memcg
->oom_notify
, list
) {
3610 if (ev
->eventfd
== eventfd
) {
3611 list_del(&ev
->list
);
3616 spin_unlock(&memcg_oom_lock
);
3619 static int mem_cgroup_oom_control_read(struct seq_file
*sf
, void *v
)
3621 struct mem_cgroup
*memcg
= mem_cgroup_from_css(seq_css(sf
));
3623 seq_printf(sf
, "oom_kill_disable %d\n", memcg
->oom_kill_disable
);
3624 seq_printf(sf
, "under_oom %d\n", (bool)memcg
->under_oom
);
3628 static int mem_cgroup_oom_control_write(struct cgroup_subsys_state
*css
,
3629 struct cftype
*cft
, u64 val
)
3631 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
3633 /* cannot set to root cgroup and only 0 and 1 are allowed */
3634 if (!css
->parent
|| !((val
== 0) || (val
== 1)))
3637 memcg
->oom_kill_disable
= val
;
3639 memcg_oom_recover(memcg
);
3644 #ifdef CONFIG_CGROUP_WRITEBACK
3646 struct list_head
*mem_cgroup_cgwb_list(struct mem_cgroup
*memcg
)
3648 return &memcg
->cgwb_list
;
3651 static int memcg_wb_domain_init(struct mem_cgroup
*memcg
, gfp_t gfp
)
3653 return wb_domain_init(&memcg
->cgwb_domain
, gfp
);
3656 static void memcg_wb_domain_exit(struct mem_cgroup
*memcg
)
3658 wb_domain_exit(&memcg
->cgwb_domain
);
3661 static void memcg_wb_domain_size_changed(struct mem_cgroup
*memcg
)
3663 wb_domain_size_changed(&memcg
->cgwb_domain
);
3666 struct wb_domain
*mem_cgroup_wb_domain(struct bdi_writeback
*wb
)
3668 struct mem_cgroup
*memcg
= mem_cgroup_from_css(wb
->memcg_css
);
3670 if (!memcg
->css
.parent
)
3673 return &memcg
->cgwb_domain
;
3677 * mem_cgroup_wb_stats - retrieve writeback related stats from its memcg
3678 * @wb: bdi_writeback in question
3679 * @pfilepages: out parameter for number of file pages
3680 * @pheadroom: out parameter for number of allocatable pages according to memcg
3681 * @pdirty: out parameter for number of dirty pages
3682 * @pwriteback: out parameter for number of pages under writeback
3684 * Determine the numbers of file, headroom, dirty, and writeback pages in
3685 * @wb's memcg. File, dirty and writeback are self-explanatory. Headroom
3686 * is a bit more involved.
3688 * A memcg's headroom is "min(max, high) - used". In the hierarchy, the
3689 * headroom is calculated as the lowest headroom of itself and the
3690 * ancestors. Note that this doesn't consider the actual amount of
3691 * available memory in the system. The caller should further cap
3692 * *@pheadroom accordingly.
3694 void mem_cgroup_wb_stats(struct bdi_writeback
*wb
, unsigned long *pfilepages
,
3695 unsigned long *pheadroom
, unsigned long *pdirty
,
3696 unsigned long *pwriteback
)
3698 struct mem_cgroup
*memcg
= mem_cgroup_from_css(wb
->memcg_css
);
3699 struct mem_cgroup
*parent
;
3701 *pdirty
= mem_cgroup_read_stat(memcg
, MEM_CGROUP_STAT_DIRTY
);
3703 /* this should eventually include NR_UNSTABLE_NFS */
3704 *pwriteback
= mem_cgroup_read_stat(memcg
, MEM_CGROUP_STAT_WRITEBACK
);
3705 *pfilepages
= mem_cgroup_nr_lru_pages(memcg
, (1 << LRU_INACTIVE_FILE
) |
3706 (1 << LRU_ACTIVE_FILE
));
3707 *pheadroom
= PAGE_COUNTER_MAX
;
3709 while ((parent
= parent_mem_cgroup(memcg
))) {
3710 unsigned long ceiling
= min(memcg
->memory
.limit
, memcg
->high
);
3711 unsigned long used
= page_counter_read(&memcg
->memory
);
3713 *pheadroom
= min(*pheadroom
, ceiling
- min(ceiling
, used
));
3718 #else /* CONFIG_CGROUP_WRITEBACK */
3720 static int memcg_wb_domain_init(struct mem_cgroup
*memcg
, gfp_t gfp
)
3725 static void memcg_wb_domain_exit(struct mem_cgroup
*memcg
)
3729 static void memcg_wb_domain_size_changed(struct mem_cgroup
*memcg
)
3733 #endif /* CONFIG_CGROUP_WRITEBACK */
3736 * DO NOT USE IN NEW FILES.
3738 * "cgroup.event_control" implementation.
3740 * This is way over-engineered. It tries to support fully configurable
3741 * events for each user. Such level of flexibility is completely
3742 * unnecessary especially in the light of the planned unified hierarchy.
3744 * Please deprecate this and replace with something simpler if at all
3749 * Unregister event and free resources.
3751 * Gets called from workqueue.
3753 static void memcg_event_remove(struct work_struct
*work
)
3755 struct mem_cgroup_event
*event
=
3756 container_of(work
, struct mem_cgroup_event
, remove
);
3757 struct mem_cgroup
*memcg
= event
->memcg
;
3759 remove_wait_queue(event
->wqh
, &event
->wait
);
3761 event
->unregister_event(memcg
, event
->eventfd
);
3763 /* Notify userspace the event is going away. */
3764 eventfd_signal(event
->eventfd
, 1);
3766 eventfd_ctx_put(event
->eventfd
);
3768 css_put(&memcg
->css
);
3772 * Gets called on POLLHUP on eventfd when user closes it.
3774 * Called with wqh->lock held and interrupts disabled.
3776 static int memcg_event_wake(wait_queue_t
*wait
, unsigned mode
,
3777 int sync
, void *key
)
3779 struct mem_cgroup_event
*event
=
3780 container_of(wait
, struct mem_cgroup_event
, wait
);
3781 struct mem_cgroup
*memcg
= event
->memcg
;
3782 unsigned long flags
= (unsigned long)key
;
3784 if (flags
& POLLHUP
) {
3786 * If the event has been detached at cgroup removal, we
3787 * can simply return knowing the other side will cleanup
3790 * We can't race against event freeing since the other
3791 * side will require wqh->lock via remove_wait_queue(),
3794 spin_lock(&memcg
->event_list_lock
);
3795 if (!list_empty(&event
->list
)) {
3796 list_del_init(&event
->list
);
3798 * We are in atomic context, but cgroup_event_remove()
3799 * may sleep, so we have to call it in workqueue.
3801 schedule_work(&event
->remove
);
3803 spin_unlock(&memcg
->event_list_lock
);
3809 static void memcg_event_ptable_queue_proc(struct file
*file
,
3810 wait_queue_head_t
*wqh
, poll_table
*pt
)
3812 struct mem_cgroup_event
*event
=
3813 container_of(pt
, struct mem_cgroup_event
, pt
);
3816 add_wait_queue(wqh
, &event
->wait
);
3820 * DO NOT USE IN NEW FILES.
3822 * Parse input and register new cgroup event handler.
3824 * Input must be in format '<event_fd> <control_fd> <args>'.
3825 * Interpretation of args is defined by control file implementation.
3827 static ssize_t
memcg_write_event_control(struct kernfs_open_file
*of
,
3828 char *buf
, size_t nbytes
, loff_t off
)
3830 struct cgroup_subsys_state
*css
= of_css(of
);
3831 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
3832 struct mem_cgroup_event
*event
;
3833 struct cgroup_subsys_state
*cfile_css
;
3834 unsigned int efd
, cfd
;
3841 buf
= strstrip(buf
);
3843 efd
= simple_strtoul(buf
, &endp
, 10);
3848 cfd
= simple_strtoul(buf
, &endp
, 10);
3849 if ((*endp
!= ' ') && (*endp
!= '\0'))
3853 event
= kzalloc(sizeof(*event
), GFP_KERNEL
);
3857 event
->memcg
= memcg
;
3858 INIT_LIST_HEAD(&event
->list
);
3859 init_poll_funcptr(&event
->pt
, memcg_event_ptable_queue_proc
);
3860 init_waitqueue_func_entry(&event
->wait
, memcg_event_wake
);
3861 INIT_WORK(&event
->remove
, memcg_event_remove
);
3869 event
->eventfd
= eventfd_ctx_fileget(efile
.file
);
3870 if (IS_ERR(event
->eventfd
)) {
3871 ret
= PTR_ERR(event
->eventfd
);
3878 goto out_put_eventfd
;
3881 /* the process need read permission on control file */
3882 /* AV: shouldn't we check that it's been opened for read instead? */
3883 ret
= inode_permission(file_inode(cfile
.file
), MAY_READ
);
3888 * Determine the event callbacks and set them in @event. This used
3889 * to be done via struct cftype but cgroup core no longer knows
3890 * about these events. The following is crude but the whole thing
3891 * is for compatibility anyway.
3893 * DO NOT ADD NEW FILES.
3895 name
= cfile
.file
->f_path
.dentry
->d_name
.name
;
3897 if (!strcmp(name
, "memory.usage_in_bytes")) {
3898 event
->register_event
= mem_cgroup_usage_register_event
;
3899 event
->unregister_event
= mem_cgroup_usage_unregister_event
;
3900 } else if (!strcmp(name
, "memory.oom_control")) {
3901 event
->register_event
= mem_cgroup_oom_register_event
;
3902 event
->unregister_event
= mem_cgroup_oom_unregister_event
;
3903 } else if (!strcmp(name
, "memory.pressure_level")) {
3904 event
->register_event
= vmpressure_register_event
;
3905 event
->unregister_event
= vmpressure_unregister_event
;
3906 } else if (!strcmp(name
, "memory.memsw.usage_in_bytes")) {
3907 event
->register_event
= memsw_cgroup_usage_register_event
;
3908 event
->unregister_event
= memsw_cgroup_usage_unregister_event
;
3915 * Verify @cfile should belong to @css. Also, remaining events are
3916 * automatically removed on cgroup destruction but the removal is
3917 * asynchronous, so take an extra ref on @css.
3919 cfile_css
= css_tryget_online_from_dir(cfile
.file
->f_path
.dentry
->d_parent
,
3920 &memory_cgrp_subsys
);
3922 if (IS_ERR(cfile_css
))
3924 if (cfile_css
!= css
) {
3929 ret
= event
->register_event(memcg
, event
->eventfd
, buf
);
3933 efile
.file
->f_op
->poll(efile
.file
, &event
->pt
);
3935 spin_lock(&memcg
->event_list_lock
);
3936 list_add(&event
->list
, &memcg
->event_list
);
3937 spin_unlock(&memcg
->event_list_lock
);
3949 eventfd_ctx_put(event
->eventfd
);
3958 static struct cftype mem_cgroup_legacy_files
[] = {
3960 .name
= "usage_in_bytes",
3961 .private = MEMFILE_PRIVATE(_MEM
, RES_USAGE
),
3962 .read_u64
= mem_cgroup_read_u64
,
3965 .name
= "max_usage_in_bytes",
3966 .private = MEMFILE_PRIVATE(_MEM
, RES_MAX_USAGE
),
3967 .write
= mem_cgroup_reset
,
3968 .read_u64
= mem_cgroup_read_u64
,
3971 .name
= "limit_in_bytes",
3972 .private = MEMFILE_PRIVATE(_MEM
, RES_LIMIT
),
3973 .write
= mem_cgroup_write
,
3974 .read_u64
= mem_cgroup_read_u64
,
3977 .name
= "soft_limit_in_bytes",
3978 .private = MEMFILE_PRIVATE(_MEM
, RES_SOFT_LIMIT
),
3979 .write
= mem_cgroup_write
,
3980 .read_u64
= mem_cgroup_read_u64
,
3984 .private = MEMFILE_PRIVATE(_MEM
, RES_FAILCNT
),
3985 .write
= mem_cgroup_reset
,
3986 .read_u64
= mem_cgroup_read_u64
,
3990 .seq_show
= memcg_stat_show
,
3993 .name
= "force_empty",
3994 .write
= mem_cgroup_force_empty_write
,
3997 .name
= "use_hierarchy",
3998 .write_u64
= mem_cgroup_hierarchy_write
,
3999 .read_u64
= mem_cgroup_hierarchy_read
,
4002 .name
= "cgroup.event_control", /* XXX: for compat */
4003 .write
= memcg_write_event_control
,
4004 .flags
= CFTYPE_NO_PREFIX
| CFTYPE_WORLD_WRITABLE
,
4007 .name
= "swappiness",
4008 .read_u64
= mem_cgroup_swappiness_read
,
4009 .write_u64
= mem_cgroup_swappiness_write
,
4012 .name
= "move_charge_at_immigrate",
4013 .read_u64
= mem_cgroup_move_charge_read
,
4014 .write_u64
= mem_cgroup_move_charge_write
,
4017 .name
= "oom_control",
4018 .seq_show
= mem_cgroup_oom_control_read
,
4019 .write_u64
= mem_cgroup_oom_control_write
,
4020 .private = MEMFILE_PRIVATE(_OOM_TYPE
, OOM_CONTROL
),
4023 .name
= "pressure_level",
4027 .name
= "numa_stat",
4028 .seq_show
= memcg_numa_stat_show
,
4032 .name
= "kmem.limit_in_bytes",
4033 .private = MEMFILE_PRIVATE(_KMEM
, RES_LIMIT
),
4034 .write
= mem_cgroup_write
,
4035 .read_u64
= mem_cgroup_read_u64
,
4038 .name
= "kmem.usage_in_bytes",
4039 .private = MEMFILE_PRIVATE(_KMEM
, RES_USAGE
),
4040 .read_u64
= mem_cgroup_read_u64
,
4043 .name
= "kmem.failcnt",
4044 .private = MEMFILE_PRIVATE(_KMEM
, RES_FAILCNT
),
4045 .write
= mem_cgroup_reset
,
4046 .read_u64
= mem_cgroup_read_u64
,
4049 .name
= "kmem.max_usage_in_bytes",
4050 .private = MEMFILE_PRIVATE(_KMEM
, RES_MAX_USAGE
),
4051 .write
= mem_cgroup_reset
,
4052 .read_u64
= mem_cgroup_read_u64
,
4054 #ifdef CONFIG_SLABINFO
4056 .name
= "kmem.slabinfo",
4057 .seq_start
= slab_start
,
4058 .seq_next
= slab_next
,
4059 .seq_stop
= slab_stop
,
4060 .seq_show
= memcg_slab_show
,
4064 .name
= "kmem.tcp.limit_in_bytes",
4065 .private = MEMFILE_PRIVATE(_TCP
, RES_LIMIT
),
4066 .write
= mem_cgroup_write
,
4067 .read_u64
= mem_cgroup_read_u64
,
4070 .name
= "kmem.tcp.usage_in_bytes",
4071 .private = MEMFILE_PRIVATE(_TCP
, RES_USAGE
),
4072 .read_u64
= mem_cgroup_read_u64
,
4075 .name
= "kmem.tcp.failcnt",
4076 .private = MEMFILE_PRIVATE(_TCP
, RES_FAILCNT
),
4077 .write
= mem_cgroup_reset
,
4078 .read_u64
= mem_cgroup_read_u64
,
4081 .name
= "kmem.tcp.max_usage_in_bytes",
4082 .private = MEMFILE_PRIVATE(_TCP
, RES_MAX_USAGE
),
4083 .write
= mem_cgroup_reset
,
4084 .read_u64
= mem_cgroup_read_u64
,
4086 { }, /* terminate */
4089 static int alloc_mem_cgroup_per_zone_info(struct mem_cgroup
*memcg
, int node
)
4091 struct mem_cgroup_per_node
*pn
;
4092 struct mem_cgroup_per_zone
*mz
;
4093 int zone
, tmp
= node
;
4095 * This routine is called against possible nodes.
4096 * But it's BUG to call kmalloc() against offline node.
4098 * TODO: this routine can waste much memory for nodes which will
4099 * never be onlined. It's better to use memory hotplug callback
4102 if (!node_state(node
, N_NORMAL_MEMORY
))
4104 pn
= kzalloc_node(sizeof(*pn
), GFP_KERNEL
, tmp
);
4108 for (zone
= 0; zone
< MAX_NR_ZONES
; zone
++) {
4109 mz
= &pn
->zoneinfo
[zone
];
4110 lruvec_init(&mz
->lruvec
);
4111 mz
->usage_in_excess
= 0;
4112 mz
->on_tree
= false;
4115 memcg
->nodeinfo
[node
] = pn
;
4119 static void free_mem_cgroup_per_zone_info(struct mem_cgroup
*memcg
, int node
)
4121 kfree(memcg
->nodeinfo
[node
]);
4124 static void mem_cgroup_free(struct mem_cgroup
*memcg
)
4128 memcg_wb_domain_exit(memcg
);
4130 free_mem_cgroup_per_zone_info(memcg
, node
);
4131 free_percpu(memcg
->stat
);
4135 static struct mem_cgroup
*mem_cgroup_alloc(void)
4137 struct mem_cgroup
*memcg
;
4141 size
= sizeof(struct mem_cgroup
);
4142 size
+= nr_node_ids
* sizeof(struct mem_cgroup_per_node
*);
4144 memcg
= kzalloc(size
, GFP_KERNEL
);
4148 memcg
->stat
= alloc_percpu(struct mem_cgroup_stat_cpu
);
4153 if (alloc_mem_cgroup_per_zone_info(memcg
, node
))
4156 if (memcg_wb_domain_init(memcg
, GFP_KERNEL
))
4159 INIT_WORK(&memcg
->high_work
, high_work_func
);
4160 memcg
->last_scanned_node
= MAX_NUMNODES
;
4161 INIT_LIST_HEAD(&memcg
->oom_notify
);
4162 mutex_init(&memcg
->thresholds_lock
);
4163 spin_lock_init(&memcg
->move_lock
);
4164 vmpressure_init(&memcg
->vmpressure
);
4165 INIT_LIST_HEAD(&memcg
->event_list
);
4166 spin_lock_init(&memcg
->event_list_lock
);
4167 memcg
->socket_pressure
= jiffies
;
4169 memcg
->kmemcg_id
= -1;
4171 #ifdef CONFIG_CGROUP_WRITEBACK
4172 INIT_LIST_HEAD(&memcg
->cgwb_list
);
4176 mem_cgroup_free(memcg
);
4180 static struct cgroup_subsys_state
* __ref
4181 mem_cgroup_css_alloc(struct cgroup_subsys_state
*parent_css
)
4183 struct mem_cgroup
*parent
= mem_cgroup_from_css(parent_css
);
4184 struct mem_cgroup
*memcg
;
4185 long error
= -ENOMEM
;
4187 memcg
= mem_cgroup_alloc();
4189 return ERR_PTR(error
);
4191 memcg
->high
= PAGE_COUNTER_MAX
;
4192 memcg
->soft_limit
= PAGE_COUNTER_MAX
;
4194 memcg
->swappiness
= mem_cgroup_swappiness(parent
);
4195 memcg
->oom_kill_disable
= parent
->oom_kill_disable
;
4197 if (parent
&& parent
->use_hierarchy
) {
4198 memcg
->use_hierarchy
= true;
4199 page_counter_init(&memcg
->memory
, &parent
->memory
);
4200 page_counter_init(&memcg
->swap
, &parent
->swap
);
4201 page_counter_init(&memcg
->memsw
, &parent
->memsw
);
4202 page_counter_init(&memcg
->kmem
, &parent
->kmem
);
4203 page_counter_init(&memcg
->tcpmem
, &parent
->tcpmem
);
4205 page_counter_init(&memcg
->memory
, NULL
);
4206 page_counter_init(&memcg
->swap
, NULL
);
4207 page_counter_init(&memcg
->memsw
, NULL
);
4208 page_counter_init(&memcg
->kmem
, NULL
);
4209 page_counter_init(&memcg
->tcpmem
, NULL
);
4211 * Deeper hierachy with use_hierarchy == false doesn't make
4212 * much sense so let cgroup subsystem know about this
4213 * unfortunate state in our controller.
4215 if (parent
!= root_mem_cgroup
)
4216 memory_cgrp_subsys
.broken_hierarchy
= true;
4219 /* The following stuff does not apply to the root */
4221 root_mem_cgroup
= memcg
;
4225 error
= memcg_propagate_kmem(parent
, memcg
);
4229 if (cgroup_subsys_on_dfl(memory_cgrp_subsys
) && !cgroup_memory_nosocket
)
4230 static_branch_inc(&memcg_sockets_enabled_key
);
4234 mem_cgroup_free(memcg
);
4239 mem_cgroup_css_online(struct cgroup_subsys_state
*css
)
4241 if (css
->id
> MEM_CGROUP_ID_MAX
)
4247 static void mem_cgroup_css_offline(struct cgroup_subsys_state
*css
)
4249 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
4250 struct mem_cgroup_event
*event
, *tmp
;
4253 * Unregister events and notify userspace.
4254 * Notify userspace about cgroup removing only after rmdir of cgroup
4255 * directory to avoid race between userspace and kernelspace.
4257 spin_lock(&memcg
->event_list_lock
);
4258 list_for_each_entry_safe(event
, tmp
, &memcg
->event_list
, list
) {
4259 list_del_init(&event
->list
);
4260 schedule_work(&event
->remove
);
4262 spin_unlock(&memcg
->event_list_lock
);
4264 memcg_offline_kmem(memcg
);
4265 wb_memcg_offline(memcg
);
4268 static void mem_cgroup_css_released(struct cgroup_subsys_state
*css
)
4270 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
4272 invalidate_reclaim_iterators(memcg
);
4275 static void mem_cgroup_css_free(struct cgroup_subsys_state
*css
)
4277 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
4279 if (cgroup_subsys_on_dfl(memory_cgrp_subsys
) && !cgroup_memory_nosocket
)
4280 static_branch_dec(&memcg_sockets_enabled_key
);
4282 if (!cgroup_subsys_on_dfl(memory_cgrp_subsys
) && memcg
->tcpmem_active
)
4283 static_branch_dec(&memcg_sockets_enabled_key
);
4285 vmpressure_cleanup(&memcg
->vmpressure
);
4286 cancel_work_sync(&memcg
->high_work
);
4287 mem_cgroup_remove_from_trees(memcg
);
4288 memcg_free_kmem(memcg
);
4289 mem_cgroup_free(memcg
);
4293 * mem_cgroup_css_reset - reset the states of a mem_cgroup
4294 * @css: the target css
4296 * Reset the states of the mem_cgroup associated with @css. This is
4297 * invoked when the userland requests disabling on the default hierarchy
4298 * but the memcg is pinned through dependency. The memcg should stop
4299 * applying policies and should revert to the vanilla state as it may be
4300 * made visible again.
4302 * The current implementation only resets the essential configurations.
4303 * This needs to be expanded to cover all the visible parts.
4305 static void mem_cgroup_css_reset(struct cgroup_subsys_state
*css
)
4307 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
4309 mem_cgroup_resize_limit(memcg
, PAGE_COUNTER_MAX
);
4310 mem_cgroup_resize_memsw_limit(memcg
, PAGE_COUNTER_MAX
);
4311 memcg_update_kmem_limit(memcg
, PAGE_COUNTER_MAX
);
4313 memcg
->high
= PAGE_COUNTER_MAX
;
4314 memcg
->soft_limit
= PAGE_COUNTER_MAX
;
4315 memcg_wb_domain_size_changed(memcg
);
4319 /* Handlers for move charge at task migration. */
4320 static int mem_cgroup_do_precharge(unsigned long count
)
4324 /* Try a single bulk charge without reclaim first, kswapd may wake */
4325 ret
= try_charge(mc
.to
, GFP_KERNEL
& ~__GFP_DIRECT_RECLAIM
, count
);
4327 mc
.precharge
+= count
;
4331 /* Try charges one by one with reclaim */
4333 ret
= try_charge(mc
.to
, GFP_KERNEL
& ~__GFP_NORETRY
, 1);
4343 * get_mctgt_type - get target type of moving charge
4344 * @vma: the vma the pte to be checked belongs
4345 * @addr: the address corresponding to the pte to be checked
4346 * @ptent: the pte to be checked
4347 * @target: the pointer the target page or swap ent will be stored(can be NULL)
4350 * 0(MC_TARGET_NONE): if the pte is not a target for move charge.
4351 * 1(MC_TARGET_PAGE): if the page corresponding to this pte is a target for
4352 * move charge. if @target is not NULL, the page is stored in target->page
4353 * with extra refcnt got(Callers should handle it).
4354 * 2(MC_TARGET_SWAP): if the swap entry corresponding to this pte is a
4355 * target for charge migration. if @target is not NULL, the entry is stored
4358 * Called with pte lock held.
4365 enum mc_target_type
{
4371 static struct page
*mc_handle_present_pte(struct vm_area_struct
*vma
,
4372 unsigned long addr
, pte_t ptent
)
4374 struct page
*page
= vm_normal_page(vma
, addr
, ptent
);
4376 if (!page
|| !page_mapped(page
))
4378 if (PageAnon(page
)) {
4379 if (!(mc
.flags
& MOVE_ANON
))
4382 if (!(mc
.flags
& MOVE_FILE
))
4385 if (!get_page_unless_zero(page
))
4392 static struct page
*mc_handle_swap_pte(struct vm_area_struct
*vma
,
4393 unsigned long addr
, pte_t ptent
, swp_entry_t
*entry
)
4395 struct page
*page
= NULL
;
4396 swp_entry_t ent
= pte_to_swp_entry(ptent
);
4398 if (!(mc
.flags
& MOVE_ANON
) || non_swap_entry(ent
))
4401 * Because lookup_swap_cache() updates some statistics counter,
4402 * we call find_get_page() with swapper_space directly.
4404 page
= find_get_page(swap_address_space(ent
), ent
.val
);
4405 if (do_memsw_account())
4406 entry
->val
= ent
.val
;
4411 static struct page
*mc_handle_swap_pte(struct vm_area_struct
*vma
,
4412 unsigned long addr
, pte_t ptent
, swp_entry_t
*entry
)
4418 static struct page
*mc_handle_file_pte(struct vm_area_struct
*vma
,
4419 unsigned long addr
, pte_t ptent
, swp_entry_t
*entry
)
4421 struct page
*page
= NULL
;
4422 struct address_space
*mapping
;
4425 if (!vma
->vm_file
) /* anonymous vma */
4427 if (!(mc
.flags
& MOVE_FILE
))
4430 mapping
= vma
->vm_file
->f_mapping
;
4431 pgoff
= linear_page_index(vma
, addr
);
4433 /* page is moved even if it's not RSS of this task(page-faulted). */
4435 /* shmem/tmpfs may report page out on swap: account for that too. */
4436 if (shmem_mapping(mapping
)) {
4437 page
= find_get_entry(mapping
, pgoff
);
4438 if (radix_tree_exceptional_entry(page
)) {
4439 swp_entry_t swp
= radix_to_swp_entry(page
);
4440 if (do_memsw_account())
4442 page
= find_get_page(swap_address_space(swp
), swp
.val
);
4445 page
= find_get_page(mapping
, pgoff
);
4447 page
= find_get_page(mapping
, pgoff
);
4453 * mem_cgroup_move_account - move account of the page
4455 * @nr_pages: number of regular pages (>1 for huge pages)
4456 * @from: mem_cgroup which the page is moved from.
4457 * @to: mem_cgroup which the page is moved to. @from != @to.
4459 * The caller must make sure the page is not on LRU (isolate_page() is useful.)
4461 * This function doesn't do "charge" to new cgroup and doesn't do "uncharge"
4464 static int mem_cgroup_move_account(struct page
*page
,
4466 struct mem_cgroup
*from
,
4467 struct mem_cgroup
*to
)
4469 unsigned long flags
;
4470 unsigned int nr_pages
= compound
? hpage_nr_pages(page
) : 1;
4474 VM_BUG_ON(from
== to
);
4475 VM_BUG_ON_PAGE(PageLRU(page
), page
);
4476 VM_BUG_ON(compound
&& !PageTransHuge(page
));
4479 * Prevent mem_cgroup_replace_page() from looking at
4480 * page->mem_cgroup of its source page while we change it.
4483 if (!trylock_page(page
))
4487 if (page
->mem_cgroup
!= from
)
4490 anon
= PageAnon(page
);
4492 spin_lock_irqsave(&from
->move_lock
, flags
);
4494 if (!anon
&& page_mapped(page
)) {
4495 __this_cpu_sub(from
->stat
->count
[MEM_CGROUP_STAT_FILE_MAPPED
],
4497 __this_cpu_add(to
->stat
->count
[MEM_CGROUP_STAT_FILE_MAPPED
],
4502 * move_lock grabbed above and caller set from->moving_account, so
4503 * mem_cgroup_update_page_stat() will serialize updates to PageDirty.
4504 * So mapping should be stable for dirty pages.
4506 if (!anon
&& PageDirty(page
)) {
4507 struct address_space
*mapping
= page_mapping(page
);
4509 if (mapping_cap_account_dirty(mapping
)) {
4510 __this_cpu_sub(from
->stat
->count
[MEM_CGROUP_STAT_DIRTY
],
4512 __this_cpu_add(to
->stat
->count
[MEM_CGROUP_STAT_DIRTY
],
4517 if (PageWriteback(page
)) {
4518 __this_cpu_sub(from
->stat
->count
[MEM_CGROUP_STAT_WRITEBACK
],
4520 __this_cpu_add(to
->stat
->count
[MEM_CGROUP_STAT_WRITEBACK
],
4525 * It is safe to change page->mem_cgroup here because the page
4526 * is referenced, charged, and isolated - we can't race with
4527 * uncharging, charging, migration, or LRU putback.
4530 /* caller should have done css_get */
4531 page
->mem_cgroup
= to
;
4532 spin_unlock_irqrestore(&from
->move_lock
, flags
);
4536 local_irq_disable();
4537 mem_cgroup_charge_statistics(to
, page
, compound
, nr_pages
);
4538 memcg_check_events(to
, page
);
4539 mem_cgroup_charge_statistics(from
, page
, compound
, -nr_pages
);
4540 memcg_check_events(from
, page
);
4548 static enum mc_target_type
get_mctgt_type(struct vm_area_struct
*vma
,
4549 unsigned long addr
, pte_t ptent
, union mc_target
*target
)
4551 struct page
*page
= NULL
;
4552 enum mc_target_type ret
= MC_TARGET_NONE
;
4553 swp_entry_t ent
= { .val
= 0 };
4555 if (pte_present(ptent
))
4556 page
= mc_handle_present_pte(vma
, addr
, ptent
);
4557 else if (is_swap_pte(ptent
))
4558 page
= mc_handle_swap_pte(vma
, addr
, ptent
, &ent
);
4559 else if (pte_none(ptent
))
4560 page
= mc_handle_file_pte(vma
, addr
, ptent
, &ent
);
4562 if (!page
&& !ent
.val
)
4566 * Do only loose check w/o serialization.
4567 * mem_cgroup_move_account() checks the page is valid or
4568 * not under LRU exclusion.
4570 if (page
->mem_cgroup
== mc
.from
) {
4571 ret
= MC_TARGET_PAGE
;
4573 target
->page
= page
;
4575 if (!ret
|| !target
)
4578 /* There is a swap entry and a page doesn't exist or isn't charged */
4579 if (ent
.val
&& !ret
&&
4580 mem_cgroup_id(mc
.from
) == lookup_swap_cgroup_id(ent
)) {
4581 ret
= MC_TARGET_SWAP
;
4588 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
4590 * We don't consider swapping or file mapped pages because THP does not
4591 * support them for now.
4592 * Caller should make sure that pmd_trans_huge(pmd) is true.
4594 static enum mc_target_type
get_mctgt_type_thp(struct vm_area_struct
*vma
,
4595 unsigned long addr
, pmd_t pmd
, union mc_target
*target
)
4597 struct page
*page
= NULL
;
4598 enum mc_target_type ret
= MC_TARGET_NONE
;
4600 page
= pmd_page(pmd
);
4601 VM_BUG_ON_PAGE(!page
|| !PageHead(page
), page
);
4602 if (!(mc
.flags
& MOVE_ANON
))
4604 if (page
->mem_cgroup
== mc
.from
) {
4605 ret
= MC_TARGET_PAGE
;
4608 target
->page
= page
;
4614 static inline enum mc_target_type
get_mctgt_type_thp(struct vm_area_struct
*vma
,
4615 unsigned long addr
, pmd_t pmd
, union mc_target
*target
)
4617 return MC_TARGET_NONE
;
4621 static int mem_cgroup_count_precharge_pte_range(pmd_t
*pmd
,
4622 unsigned long addr
, unsigned long end
,
4623 struct mm_walk
*walk
)
4625 struct vm_area_struct
*vma
= walk
->vma
;
4629 if (pmd_trans_huge_lock(pmd
, vma
, &ptl
)) {
4630 if (get_mctgt_type_thp(vma
, addr
, *pmd
, NULL
) == MC_TARGET_PAGE
)
4631 mc
.precharge
+= HPAGE_PMD_NR
;
4636 if (pmd_trans_unstable(pmd
))
4638 pte
= pte_offset_map_lock(vma
->vm_mm
, pmd
, addr
, &ptl
);
4639 for (; addr
!= end
; pte
++, addr
+= PAGE_SIZE
)
4640 if (get_mctgt_type(vma
, addr
, *pte
, NULL
))
4641 mc
.precharge
++; /* increment precharge temporarily */
4642 pte_unmap_unlock(pte
- 1, ptl
);
4648 static unsigned long mem_cgroup_count_precharge(struct mm_struct
*mm
)
4650 unsigned long precharge
;
4652 struct mm_walk mem_cgroup_count_precharge_walk
= {
4653 .pmd_entry
= mem_cgroup_count_precharge_pte_range
,
4656 down_read(&mm
->mmap_sem
);
4657 walk_page_range(0, ~0UL, &mem_cgroup_count_precharge_walk
);
4658 up_read(&mm
->mmap_sem
);
4660 precharge
= mc
.precharge
;
4666 static int mem_cgroup_precharge_mc(struct mm_struct
*mm
)
4668 unsigned long precharge
= mem_cgroup_count_precharge(mm
);
4670 VM_BUG_ON(mc
.moving_task
);
4671 mc
.moving_task
= current
;
4672 return mem_cgroup_do_precharge(precharge
);
4675 /* cancels all extra charges on mc.from and mc.to, and wakes up all waiters. */
4676 static void __mem_cgroup_clear_mc(void)
4678 struct mem_cgroup
*from
= mc
.from
;
4679 struct mem_cgroup
*to
= mc
.to
;
4681 /* we must uncharge all the leftover precharges from mc.to */
4683 cancel_charge(mc
.to
, mc
.precharge
);
4687 * we didn't uncharge from mc.from at mem_cgroup_move_account(), so
4688 * we must uncharge here.
4690 if (mc
.moved_charge
) {
4691 cancel_charge(mc
.from
, mc
.moved_charge
);
4692 mc
.moved_charge
= 0;
4694 /* we must fixup refcnts and charges */
4695 if (mc
.moved_swap
) {
4696 /* uncharge swap account from the old cgroup */
4697 if (!mem_cgroup_is_root(mc
.from
))
4698 page_counter_uncharge(&mc
.from
->memsw
, mc
.moved_swap
);
4701 * we charged both to->memory and to->memsw, so we
4702 * should uncharge to->memory.
4704 if (!mem_cgroup_is_root(mc
.to
))
4705 page_counter_uncharge(&mc
.to
->memory
, mc
.moved_swap
);
4707 css_put_many(&mc
.from
->css
, mc
.moved_swap
);
4709 /* we've already done css_get(mc.to) */
4712 memcg_oom_recover(from
);
4713 memcg_oom_recover(to
);
4714 wake_up_all(&mc
.waitq
);
4717 static void mem_cgroup_clear_mc(void)
4720 * we must clear moving_task before waking up waiters at the end of
4723 mc
.moving_task
= NULL
;
4724 __mem_cgroup_clear_mc();
4725 spin_lock(&mc
.lock
);
4728 spin_unlock(&mc
.lock
);
4731 static int mem_cgroup_can_attach(struct cgroup_taskset
*tset
)
4733 struct cgroup_subsys_state
*css
;
4734 struct mem_cgroup
*memcg
= NULL
; /* unneeded init to make gcc happy */
4735 struct mem_cgroup
*from
;
4736 struct task_struct
*leader
, *p
;
4737 struct mm_struct
*mm
;
4738 unsigned long move_flags
;
4741 /* charge immigration isn't supported on the default hierarchy */
4742 if (cgroup_subsys_on_dfl(memory_cgrp_subsys
))
4746 * Multi-process migrations only happen on the default hierarchy
4747 * where charge immigration is not used. Perform charge
4748 * immigration if @tset contains a leader and whine if there are
4752 cgroup_taskset_for_each_leader(leader
, css
, tset
) {
4755 memcg
= mem_cgroup_from_css(css
);
4761 * We are now commited to this value whatever it is. Changes in this
4762 * tunable will only affect upcoming migrations, not the current one.
4763 * So we need to save it, and keep it going.
4765 move_flags
= READ_ONCE(memcg
->move_charge_at_immigrate
);
4769 from
= mem_cgroup_from_task(p
);
4771 VM_BUG_ON(from
== memcg
);
4773 mm
= get_task_mm(p
);
4776 /* We move charges only when we move a owner of the mm */
4777 if (mm
->owner
== p
) {
4780 VM_BUG_ON(mc
.precharge
);
4781 VM_BUG_ON(mc
.moved_charge
);
4782 VM_BUG_ON(mc
.moved_swap
);
4784 spin_lock(&mc
.lock
);
4787 mc
.flags
= move_flags
;
4788 spin_unlock(&mc
.lock
);
4789 /* We set mc.moving_task later */
4791 ret
= mem_cgroup_precharge_mc(mm
);
4793 mem_cgroup_clear_mc();
4799 static void mem_cgroup_cancel_attach(struct cgroup_taskset
*tset
)
4802 mem_cgroup_clear_mc();
4805 static int mem_cgroup_move_charge_pte_range(pmd_t
*pmd
,
4806 unsigned long addr
, unsigned long end
,
4807 struct mm_walk
*walk
)
4810 struct vm_area_struct
*vma
= walk
->vma
;
4813 enum mc_target_type target_type
;
4814 union mc_target target
;
4817 if (pmd_trans_huge_lock(pmd
, vma
, &ptl
)) {
4818 if (mc
.precharge
< HPAGE_PMD_NR
) {
4822 target_type
= get_mctgt_type_thp(vma
, addr
, *pmd
, &target
);
4823 if (target_type
== MC_TARGET_PAGE
) {
4825 if (!isolate_lru_page(page
)) {
4826 if (!mem_cgroup_move_account(page
, true,
4828 mc
.precharge
-= HPAGE_PMD_NR
;
4829 mc
.moved_charge
+= HPAGE_PMD_NR
;
4831 putback_lru_page(page
);
4839 if (pmd_trans_unstable(pmd
))
4842 pte
= pte_offset_map_lock(vma
->vm_mm
, pmd
, addr
, &ptl
);
4843 for (; addr
!= end
; addr
+= PAGE_SIZE
) {
4844 pte_t ptent
= *(pte
++);
4850 switch (get_mctgt_type(vma
, addr
, ptent
, &target
)) {
4851 case MC_TARGET_PAGE
:
4854 * We can have a part of the split pmd here. Moving it
4855 * can be done but it would be too convoluted so simply
4856 * ignore such a partial THP and keep it in original
4857 * memcg. There should be somebody mapping the head.
4859 if (PageTransCompound(page
))
4861 if (isolate_lru_page(page
))
4863 if (!mem_cgroup_move_account(page
, false,
4866 /* we uncharge from mc.from later. */
4869 putback_lru_page(page
);
4870 put
: /* get_mctgt_type() gets the page */
4873 case MC_TARGET_SWAP
:
4875 if (!mem_cgroup_move_swap_account(ent
, mc
.from
, mc
.to
)) {
4877 /* we fixup refcnts and charges later. */
4885 pte_unmap_unlock(pte
- 1, ptl
);
4890 * We have consumed all precharges we got in can_attach().
4891 * We try charge one by one, but don't do any additional
4892 * charges to mc.to if we have failed in charge once in attach()
4895 ret
= mem_cgroup_do_precharge(1);
4903 static void mem_cgroup_move_charge(struct mm_struct
*mm
)
4905 struct mm_walk mem_cgroup_move_charge_walk
= {
4906 .pmd_entry
= mem_cgroup_move_charge_pte_range
,
4910 lru_add_drain_all();
4912 * Signal mem_cgroup_begin_page_stat() to take the memcg's
4913 * move_lock while we're moving its pages to another memcg.
4914 * Then wait for already started RCU-only updates to finish.
4916 atomic_inc(&mc
.from
->moving_account
);
4919 if (unlikely(!down_read_trylock(&mm
->mmap_sem
))) {
4921 * Someone who are holding the mmap_sem might be waiting in
4922 * waitq. So we cancel all extra charges, wake up all waiters,
4923 * and retry. Because we cancel precharges, we might not be able
4924 * to move enough charges, but moving charge is a best-effort
4925 * feature anyway, so it wouldn't be a big problem.
4927 __mem_cgroup_clear_mc();
4932 * When we have consumed all precharges and failed in doing
4933 * additional charge, the page walk just aborts.
4935 walk_page_range(0, ~0UL, &mem_cgroup_move_charge_walk
);
4936 up_read(&mm
->mmap_sem
);
4937 atomic_dec(&mc
.from
->moving_account
);
4940 static void mem_cgroup_move_task(struct cgroup_taskset
*tset
)
4942 struct cgroup_subsys_state
*css
;
4943 struct task_struct
*p
= cgroup_taskset_first(tset
, &css
);
4944 struct mm_struct
*mm
= get_task_mm(p
);
4948 mem_cgroup_move_charge(mm
);
4952 mem_cgroup_clear_mc();
4954 #else /* !CONFIG_MMU */
4955 static int mem_cgroup_can_attach(struct cgroup_taskset
*tset
)
4959 static void mem_cgroup_cancel_attach(struct cgroup_taskset
*tset
)
4962 static void mem_cgroup_move_task(struct cgroup_taskset
*tset
)
4968 * Cgroup retains root cgroups across [un]mount cycles making it necessary
4969 * to verify whether we're attached to the default hierarchy on each mount
4972 static void mem_cgroup_bind(struct cgroup_subsys_state
*root_css
)
4975 * use_hierarchy is forced on the default hierarchy. cgroup core
4976 * guarantees that @root doesn't have any children, so turning it
4977 * on for the root memcg is enough.
4979 if (cgroup_subsys_on_dfl(memory_cgrp_subsys
))
4980 root_mem_cgroup
->use_hierarchy
= true;
4982 root_mem_cgroup
->use_hierarchy
= false;
4985 static u64
memory_current_read(struct cgroup_subsys_state
*css
,
4988 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
4990 return (u64
)page_counter_read(&memcg
->memory
) * PAGE_SIZE
;
4993 static int memory_low_show(struct seq_file
*m
, void *v
)
4995 struct mem_cgroup
*memcg
= mem_cgroup_from_css(seq_css(m
));
4996 unsigned long low
= READ_ONCE(memcg
->low
);
4998 if (low
== PAGE_COUNTER_MAX
)
4999 seq_puts(m
, "max\n");
5001 seq_printf(m
, "%llu\n", (u64
)low
* PAGE_SIZE
);
5006 static ssize_t
memory_low_write(struct kernfs_open_file
*of
,
5007 char *buf
, size_t nbytes
, loff_t off
)
5009 struct mem_cgroup
*memcg
= mem_cgroup_from_css(of_css(of
));
5013 buf
= strstrip(buf
);
5014 err
= page_counter_memparse(buf
, "max", &low
);
5023 static int memory_high_show(struct seq_file
*m
, void *v
)
5025 struct mem_cgroup
*memcg
= mem_cgroup_from_css(seq_css(m
));
5026 unsigned long high
= READ_ONCE(memcg
->high
);
5028 if (high
== PAGE_COUNTER_MAX
)
5029 seq_puts(m
, "max\n");
5031 seq_printf(m
, "%llu\n", (u64
)high
* PAGE_SIZE
);
5036 static ssize_t
memory_high_write(struct kernfs_open_file
*of
,
5037 char *buf
, size_t nbytes
, loff_t off
)
5039 struct mem_cgroup
*memcg
= mem_cgroup_from_css(of_css(of
));
5043 buf
= strstrip(buf
);
5044 err
= page_counter_memparse(buf
, "max", &high
);
5050 memcg_wb_domain_size_changed(memcg
);
5054 static int memory_max_show(struct seq_file
*m
, void *v
)
5056 struct mem_cgroup
*memcg
= mem_cgroup_from_css(seq_css(m
));
5057 unsigned long max
= READ_ONCE(memcg
->memory
.limit
);
5059 if (max
== PAGE_COUNTER_MAX
)
5060 seq_puts(m
, "max\n");
5062 seq_printf(m
, "%llu\n", (u64
)max
* PAGE_SIZE
);
5067 static ssize_t
memory_max_write(struct kernfs_open_file
*of
,
5068 char *buf
, size_t nbytes
, loff_t off
)
5070 struct mem_cgroup
*memcg
= mem_cgroup_from_css(of_css(of
));
5074 buf
= strstrip(buf
);
5075 err
= page_counter_memparse(buf
, "max", &max
);
5079 err
= mem_cgroup_resize_limit(memcg
, max
);
5083 memcg_wb_domain_size_changed(memcg
);
5087 static int memory_events_show(struct seq_file
*m
, void *v
)
5089 struct mem_cgroup
*memcg
= mem_cgroup_from_css(seq_css(m
));
5091 seq_printf(m
, "low %lu\n", mem_cgroup_read_events(memcg
, MEMCG_LOW
));
5092 seq_printf(m
, "high %lu\n", mem_cgroup_read_events(memcg
, MEMCG_HIGH
));
5093 seq_printf(m
, "max %lu\n", mem_cgroup_read_events(memcg
, MEMCG_MAX
));
5094 seq_printf(m
, "oom %lu\n", mem_cgroup_read_events(memcg
, MEMCG_OOM
));
5099 static struct cftype memory_files
[] = {
5102 .flags
= CFTYPE_NOT_ON_ROOT
,
5103 .read_u64
= memory_current_read
,
5107 .flags
= CFTYPE_NOT_ON_ROOT
,
5108 .seq_show
= memory_low_show
,
5109 .write
= memory_low_write
,
5113 .flags
= CFTYPE_NOT_ON_ROOT
,
5114 .seq_show
= memory_high_show
,
5115 .write
= memory_high_write
,
5119 .flags
= CFTYPE_NOT_ON_ROOT
,
5120 .seq_show
= memory_max_show
,
5121 .write
= memory_max_write
,
5125 .flags
= CFTYPE_NOT_ON_ROOT
,
5126 .file_offset
= offsetof(struct mem_cgroup
, events_file
),
5127 .seq_show
= memory_events_show
,
5132 struct cgroup_subsys memory_cgrp_subsys
= {
5133 .css_alloc
= mem_cgroup_css_alloc
,
5134 .css_online
= mem_cgroup_css_online
,
5135 .css_offline
= mem_cgroup_css_offline
,
5136 .css_released
= mem_cgroup_css_released
,
5137 .css_free
= mem_cgroup_css_free
,
5138 .css_reset
= mem_cgroup_css_reset
,
5139 .can_attach
= mem_cgroup_can_attach
,
5140 .cancel_attach
= mem_cgroup_cancel_attach
,
5141 .attach
= mem_cgroup_move_task
,
5142 .bind
= mem_cgroup_bind
,
5143 .dfl_cftypes
= memory_files
,
5144 .legacy_cftypes
= mem_cgroup_legacy_files
,
5149 * mem_cgroup_low - check if memory consumption is below the normal range
5150 * @root: the highest ancestor to consider
5151 * @memcg: the memory cgroup to check
5153 * Returns %true if memory consumption of @memcg, and that of all
5154 * configurable ancestors up to @root, is below the normal range.
5156 bool mem_cgroup_low(struct mem_cgroup
*root
, struct mem_cgroup
*memcg
)
5158 if (mem_cgroup_disabled())
5162 * The toplevel group doesn't have a configurable range, so
5163 * it's never low when looked at directly, and it is not
5164 * considered an ancestor when assessing the hierarchy.
5167 if (memcg
== root_mem_cgroup
)
5170 if (page_counter_read(&memcg
->memory
) >= memcg
->low
)
5173 while (memcg
!= root
) {
5174 memcg
= parent_mem_cgroup(memcg
);
5176 if (memcg
== root_mem_cgroup
)
5179 if (page_counter_read(&memcg
->memory
) >= memcg
->low
)
5186 * mem_cgroup_try_charge - try charging a page
5187 * @page: page to charge
5188 * @mm: mm context of the victim
5189 * @gfp_mask: reclaim mode
5190 * @memcgp: charged memcg return
5192 * Try to charge @page to the memcg that @mm belongs to, reclaiming
5193 * pages according to @gfp_mask if necessary.
5195 * Returns 0 on success, with *@memcgp pointing to the charged memcg.
5196 * Otherwise, an error code is returned.
5198 * After page->mapping has been set up, the caller must finalize the
5199 * charge with mem_cgroup_commit_charge(). Or abort the transaction
5200 * with mem_cgroup_cancel_charge() in case page instantiation fails.
5202 int mem_cgroup_try_charge(struct page
*page
, struct mm_struct
*mm
,
5203 gfp_t gfp_mask
, struct mem_cgroup
**memcgp
,
5206 struct mem_cgroup
*memcg
= NULL
;
5207 unsigned int nr_pages
= compound
? hpage_nr_pages(page
) : 1;
5210 if (mem_cgroup_disabled())
5213 if (PageSwapCache(page
)) {
5215 * Every swap fault against a single page tries to charge the
5216 * page, bail as early as possible. shmem_unuse() encounters
5217 * already charged pages, too. The USED bit is protected by
5218 * the page lock, which serializes swap cache removal, which
5219 * in turn serializes uncharging.
5221 VM_BUG_ON_PAGE(!PageLocked(page
), page
);
5222 if (page
->mem_cgroup
)
5225 if (do_swap_account
) {
5226 swp_entry_t ent
= { .val
= page_private(page
), };
5227 unsigned short id
= lookup_swap_cgroup_id(ent
);
5230 memcg
= mem_cgroup_from_id(id
);
5231 if (memcg
&& !css_tryget_online(&memcg
->css
))
5238 memcg
= get_mem_cgroup_from_mm(mm
);
5240 ret
= try_charge(memcg
, gfp_mask
, nr_pages
);
5242 css_put(&memcg
->css
);
5249 * mem_cgroup_commit_charge - commit a page charge
5250 * @page: page to charge
5251 * @memcg: memcg to charge the page to
5252 * @lrucare: page might be on LRU already
5254 * Finalize a charge transaction started by mem_cgroup_try_charge(),
5255 * after page->mapping has been set up. This must happen atomically
5256 * as part of the page instantiation, i.e. under the page table lock
5257 * for anonymous pages, under the page lock for page and swap cache.
5259 * In addition, the page must not be on the LRU during the commit, to
5260 * prevent racing with task migration. If it might be, use @lrucare.
5262 * Use mem_cgroup_cancel_charge() to cancel the transaction instead.
5264 void mem_cgroup_commit_charge(struct page
*page
, struct mem_cgroup
*memcg
,
5265 bool lrucare
, bool compound
)
5267 unsigned int nr_pages
= compound
? hpage_nr_pages(page
) : 1;
5269 VM_BUG_ON_PAGE(!page
->mapping
, page
);
5270 VM_BUG_ON_PAGE(PageLRU(page
) && !lrucare
, page
);
5272 if (mem_cgroup_disabled())
5275 * Swap faults will attempt to charge the same page multiple
5276 * times. But reuse_swap_page() might have removed the page
5277 * from swapcache already, so we can't check PageSwapCache().
5282 commit_charge(page
, memcg
, lrucare
);
5284 local_irq_disable();
5285 mem_cgroup_charge_statistics(memcg
, page
, compound
, nr_pages
);
5286 memcg_check_events(memcg
, page
);
5289 if (do_memsw_account() && PageSwapCache(page
)) {
5290 swp_entry_t entry
= { .val
= page_private(page
) };
5292 * The swap entry might not get freed for a long time,
5293 * let's not wait for it. The page already received a
5294 * memory+swap charge, drop the swap entry duplicate.
5296 mem_cgroup_uncharge_swap(entry
);
5301 * mem_cgroup_cancel_charge - cancel a page charge
5302 * @page: page to charge
5303 * @memcg: memcg to charge the page to
5305 * Cancel a charge transaction started by mem_cgroup_try_charge().
5307 void mem_cgroup_cancel_charge(struct page
*page
, struct mem_cgroup
*memcg
,
5310 unsigned int nr_pages
= compound
? hpage_nr_pages(page
) : 1;
5312 if (mem_cgroup_disabled())
5315 * Swap faults will attempt to charge the same page multiple
5316 * times. But reuse_swap_page() might have removed the page
5317 * from swapcache already, so we can't check PageSwapCache().
5322 cancel_charge(memcg
, nr_pages
);
5325 static void uncharge_batch(struct mem_cgroup
*memcg
, unsigned long pgpgout
,
5326 unsigned long nr_anon
, unsigned long nr_file
,
5327 unsigned long nr_huge
, struct page
*dummy_page
)
5329 unsigned long nr_pages
= nr_anon
+ nr_file
;
5330 unsigned long flags
;
5332 if (!mem_cgroup_is_root(memcg
)) {
5333 page_counter_uncharge(&memcg
->memory
, nr_pages
);
5334 if (do_memsw_account())
5335 page_counter_uncharge(&memcg
->memsw
, nr_pages
);
5336 memcg_oom_recover(memcg
);
5339 local_irq_save(flags
);
5340 __this_cpu_sub(memcg
->stat
->count
[MEM_CGROUP_STAT_RSS
], nr_anon
);
5341 __this_cpu_sub(memcg
->stat
->count
[MEM_CGROUP_STAT_CACHE
], nr_file
);
5342 __this_cpu_sub(memcg
->stat
->count
[MEM_CGROUP_STAT_RSS_HUGE
], nr_huge
);
5343 __this_cpu_add(memcg
->stat
->events
[MEM_CGROUP_EVENTS_PGPGOUT
], pgpgout
);
5344 __this_cpu_add(memcg
->stat
->nr_page_events
, nr_pages
);
5345 memcg_check_events(memcg
, dummy_page
);
5346 local_irq_restore(flags
);
5348 if (!mem_cgroup_is_root(memcg
))
5349 css_put_many(&memcg
->css
, nr_pages
);
5352 static void uncharge_list(struct list_head
*page_list
)
5354 struct mem_cgroup
*memcg
= NULL
;
5355 unsigned long nr_anon
= 0;
5356 unsigned long nr_file
= 0;
5357 unsigned long nr_huge
= 0;
5358 unsigned long pgpgout
= 0;
5359 struct list_head
*next
;
5362 next
= page_list
->next
;
5364 unsigned int nr_pages
= 1;
5366 page
= list_entry(next
, struct page
, lru
);
5367 next
= page
->lru
.next
;
5369 VM_BUG_ON_PAGE(PageLRU(page
), page
);
5370 VM_BUG_ON_PAGE(page_count(page
), page
);
5372 if (!page
->mem_cgroup
)
5376 * Nobody should be changing or seriously looking at
5377 * page->mem_cgroup at this point, we have fully
5378 * exclusive access to the page.
5381 if (memcg
!= page
->mem_cgroup
) {
5383 uncharge_batch(memcg
, pgpgout
, nr_anon
, nr_file
,
5385 pgpgout
= nr_anon
= nr_file
= nr_huge
= 0;
5387 memcg
= page
->mem_cgroup
;
5390 if (PageTransHuge(page
)) {
5391 nr_pages
<<= compound_order(page
);
5392 VM_BUG_ON_PAGE(!PageTransHuge(page
), page
);
5393 nr_huge
+= nr_pages
;
5397 nr_anon
+= nr_pages
;
5399 nr_file
+= nr_pages
;
5401 page
->mem_cgroup
= NULL
;
5404 } while (next
!= page_list
);
5407 uncharge_batch(memcg
, pgpgout
, nr_anon
, nr_file
,
5412 * mem_cgroup_uncharge - uncharge a page
5413 * @page: page to uncharge
5415 * Uncharge a page previously charged with mem_cgroup_try_charge() and
5416 * mem_cgroup_commit_charge().
5418 void mem_cgroup_uncharge(struct page
*page
)
5420 if (mem_cgroup_disabled())
5423 /* Don't touch page->lru of any random page, pre-check: */
5424 if (!page
->mem_cgroup
)
5427 INIT_LIST_HEAD(&page
->lru
);
5428 uncharge_list(&page
->lru
);
5432 * mem_cgroup_uncharge_list - uncharge a list of page
5433 * @page_list: list of pages to uncharge
5435 * Uncharge a list of pages previously charged with
5436 * mem_cgroup_try_charge() and mem_cgroup_commit_charge().
5438 void mem_cgroup_uncharge_list(struct list_head
*page_list
)
5440 if (mem_cgroup_disabled())
5443 if (!list_empty(page_list
))
5444 uncharge_list(page_list
);
5448 * mem_cgroup_replace_page - migrate a charge to another page
5449 * @oldpage: currently charged page
5450 * @newpage: page to transfer the charge to
5452 * Migrate the charge from @oldpage to @newpage.
5454 * Both pages must be locked, @newpage->mapping must be set up.
5455 * Either or both pages might be on the LRU already.
5457 void mem_cgroup_replace_page(struct page
*oldpage
, struct page
*newpage
)
5459 struct mem_cgroup
*memcg
;
5460 unsigned int nr_pages
;
5463 VM_BUG_ON_PAGE(!PageLocked(oldpage
), oldpage
);
5464 VM_BUG_ON_PAGE(!PageLocked(newpage
), newpage
);
5465 VM_BUG_ON_PAGE(PageAnon(oldpage
) != PageAnon(newpage
), newpage
);
5466 VM_BUG_ON_PAGE(PageTransHuge(oldpage
) != PageTransHuge(newpage
),
5469 if (mem_cgroup_disabled())
5472 /* Page cache replacement: new page already charged? */
5473 if (newpage
->mem_cgroup
)
5476 /* Swapcache readahead pages can get replaced before being charged */
5477 memcg
= oldpage
->mem_cgroup
;
5481 /* Force-charge the new page. The old one will be freed soon */
5482 compound
= PageTransHuge(newpage
);
5483 nr_pages
= compound
? hpage_nr_pages(newpage
) : 1;
5485 page_counter_charge(&memcg
->memory
, nr_pages
);
5486 if (do_memsw_account())
5487 page_counter_charge(&memcg
->memsw
, nr_pages
);
5488 css_get_many(&memcg
->css
, nr_pages
);
5490 commit_charge(newpage
, memcg
, true);
5492 local_irq_disable();
5493 mem_cgroup_charge_statistics(memcg
, newpage
, compound
, nr_pages
);
5494 memcg_check_events(memcg
, newpage
);
5498 DEFINE_STATIC_KEY_FALSE(memcg_sockets_enabled_key
);
5499 EXPORT_SYMBOL(memcg_sockets_enabled_key
);
5501 void sock_update_memcg(struct sock
*sk
)
5503 struct mem_cgroup
*memcg
;
5505 /* Socket cloning can throw us here with sk_cgrp already
5506 * filled. It won't however, necessarily happen from
5507 * process context. So the test for root memcg given
5508 * the current task's memcg won't help us in this case.
5510 * Respecting the original socket's memcg is a better
5511 * decision in this case.
5514 BUG_ON(mem_cgroup_is_root(sk
->sk_memcg
));
5515 css_get(&sk
->sk_memcg
->css
);
5520 memcg
= mem_cgroup_from_task(current
);
5521 if (memcg
== root_mem_cgroup
)
5523 if (!cgroup_subsys_on_dfl(memory_cgrp_subsys
) && !memcg
->tcpmem_active
)
5525 if (css_tryget_online(&memcg
->css
))
5526 sk
->sk_memcg
= memcg
;
5530 EXPORT_SYMBOL(sock_update_memcg
);
5532 void sock_release_memcg(struct sock
*sk
)
5534 WARN_ON(!sk
->sk_memcg
);
5535 css_put(&sk
->sk_memcg
->css
);
5539 * mem_cgroup_charge_skmem - charge socket memory
5540 * @memcg: memcg to charge
5541 * @nr_pages: number of pages to charge
5543 * Charges @nr_pages to @memcg. Returns %true if the charge fit within
5544 * @memcg's configured limit, %false if the charge had to be forced.
5546 bool mem_cgroup_charge_skmem(struct mem_cgroup
*memcg
, unsigned int nr_pages
)
5548 gfp_t gfp_mask
= GFP_KERNEL
;
5550 if (!cgroup_subsys_on_dfl(memory_cgrp_subsys
)) {
5551 struct page_counter
*fail
;
5553 if (page_counter_try_charge(&memcg
->tcpmem
, nr_pages
, &fail
)) {
5554 memcg
->tcpmem_pressure
= 0;
5557 page_counter_charge(&memcg
->tcpmem
, nr_pages
);
5558 memcg
->tcpmem_pressure
= 1;
5562 /* Don't block in the packet receive path */
5564 gfp_mask
= GFP_NOWAIT
;
5566 if (try_charge(memcg
, gfp_mask
, nr_pages
) == 0)
5569 try_charge(memcg
, gfp_mask
|__GFP_NOFAIL
, nr_pages
);
5574 * mem_cgroup_uncharge_skmem - uncharge socket memory
5575 * @memcg - memcg to uncharge
5576 * @nr_pages - number of pages to uncharge
5578 void mem_cgroup_uncharge_skmem(struct mem_cgroup
*memcg
, unsigned int nr_pages
)
5580 if (!cgroup_subsys_on_dfl(memory_cgrp_subsys
)) {
5581 page_counter_uncharge(&memcg
->tcpmem
, nr_pages
);
5585 page_counter_uncharge(&memcg
->memory
, nr_pages
);
5586 css_put_many(&memcg
->css
, nr_pages
);
5589 static int __init
cgroup_memory(char *s
)
5593 while ((token
= strsep(&s
, ",")) != NULL
) {
5596 if (!strcmp(token
, "nosocket"))
5597 cgroup_memory_nosocket
= true;
5598 if (!strcmp(token
, "nokmem"))
5599 cgroup_memory_nokmem
= true;
5603 __setup("cgroup.memory=", cgroup_memory
);
5606 * subsys_initcall() for memory controller.
5608 * Some parts like hotcpu_notifier() have to be initialized from this context
5609 * because of lock dependencies (cgroup_lock -> cpu hotplug) but basically
5610 * everything that doesn't depend on a specific mem_cgroup structure should
5611 * be initialized from here.
5613 static int __init
mem_cgroup_init(void)
5617 hotcpu_notifier(memcg_cpu_hotplug_callback
, 0);
5619 for_each_possible_cpu(cpu
)
5620 INIT_WORK(&per_cpu_ptr(&memcg_stock
, cpu
)->work
,
5623 for_each_node(node
) {
5624 struct mem_cgroup_tree_per_node
*rtpn
;
5627 rtpn
= kzalloc_node(sizeof(*rtpn
), GFP_KERNEL
,
5628 node_online(node
) ? node
: NUMA_NO_NODE
);
5630 for (zone
= 0; zone
< MAX_NR_ZONES
; zone
++) {
5631 struct mem_cgroup_tree_per_zone
*rtpz
;
5633 rtpz
= &rtpn
->rb_tree_per_zone
[zone
];
5634 rtpz
->rb_root
= RB_ROOT
;
5635 spin_lock_init(&rtpz
->lock
);
5637 soft_limit_tree
.rb_tree_per_node
[node
] = rtpn
;
5642 subsys_initcall(mem_cgroup_init
);
5644 #ifdef CONFIG_MEMCG_SWAP
5646 * mem_cgroup_swapout - transfer a memsw charge to swap
5647 * @page: page whose memsw charge to transfer
5648 * @entry: swap entry to move the charge to
5650 * Transfer the memsw charge of @page to @entry.
5652 void mem_cgroup_swapout(struct page
*page
, swp_entry_t entry
)
5654 struct mem_cgroup
*memcg
;
5655 unsigned short oldid
;
5657 VM_BUG_ON_PAGE(PageLRU(page
), page
);
5658 VM_BUG_ON_PAGE(page_count(page
), page
);
5660 if (!do_memsw_account())
5663 memcg
= page
->mem_cgroup
;
5665 /* Readahead page, never charged */
5669 oldid
= swap_cgroup_record(entry
, mem_cgroup_id(memcg
));
5670 VM_BUG_ON_PAGE(oldid
, page
);
5671 mem_cgroup_swap_statistics(memcg
, true);
5673 page
->mem_cgroup
= NULL
;
5675 if (!mem_cgroup_is_root(memcg
))
5676 page_counter_uncharge(&memcg
->memory
, 1);
5679 * Interrupts should be disabled here because the caller holds the
5680 * mapping->tree_lock lock which is taken with interrupts-off. It is
5681 * important here to have the interrupts disabled because it is the
5682 * only synchronisation we have for udpating the per-CPU variables.
5684 VM_BUG_ON(!irqs_disabled());
5685 mem_cgroup_charge_statistics(memcg
, page
, false, -1);
5686 memcg_check_events(memcg
, page
);
5690 * mem_cgroup_try_charge_swap - try charging a swap entry
5691 * @page: page being added to swap
5692 * @entry: swap entry to charge
5694 * Try to charge @entry to the memcg that @page belongs to.
5696 * Returns 0 on success, -ENOMEM on failure.
5698 int mem_cgroup_try_charge_swap(struct page
*page
, swp_entry_t entry
)
5700 struct mem_cgroup
*memcg
;
5701 struct page_counter
*counter
;
5702 unsigned short oldid
;
5704 if (!cgroup_subsys_on_dfl(memory_cgrp_subsys
) || !do_swap_account
)
5707 memcg
= page
->mem_cgroup
;
5709 /* Readahead page, never charged */
5713 if (!mem_cgroup_is_root(memcg
) &&
5714 !page_counter_try_charge(&memcg
->swap
, 1, &counter
))
5717 oldid
= swap_cgroup_record(entry
, mem_cgroup_id(memcg
));
5718 VM_BUG_ON_PAGE(oldid
, page
);
5719 mem_cgroup_swap_statistics(memcg
, true);
5721 css_get(&memcg
->css
);
5726 * mem_cgroup_uncharge_swap - uncharge a swap entry
5727 * @entry: swap entry to uncharge
5729 * Drop the swap charge associated with @entry.
5731 void mem_cgroup_uncharge_swap(swp_entry_t entry
)
5733 struct mem_cgroup
*memcg
;
5736 if (!do_swap_account
)
5739 id
= swap_cgroup_record(entry
, 0);
5741 memcg
= mem_cgroup_from_id(id
);
5743 if (!mem_cgroup_is_root(memcg
)) {
5744 if (cgroup_subsys_on_dfl(memory_cgrp_subsys
))
5745 page_counter_uncharge(&memcg
->swap
, 1);
5747 page_counter_uncharge(&memcg
->memsw
, 1);
5749 mem_cgroup_swap_statistics(memcg
, false);
5750 css_put(&memcg
->css
);
5755 long mem_cgroup_get_nr_swap_pages(struct mem_cgroup
*memcg
)
5757 long nr_swap_pages
= get_nr_swap_pages();
5759 if (!do_swap_account
|| !cgroup_subsys_on_dfl(memory_cgrp_subsys
))
5760 return nr_swap_pages
;
5761 for (; memcg
!= root_mem_cgroup
; memcg
= parent_mem_cgroup(memcg
))
5762 nr_swap_pages
= min_t(long, nr_swap_pages
,
5763 READ_ONCE(memcg
->swap
.limit
) -
5764 page_counter_read(&memcg
->swap
));
5765 return nr_swap_pages
;
5768 bool mem_cgroup_swap_full(struct page
*page
)
5770 struct mem_cgroup
*memcg
;
5772 VM_BUG_ON_PAGE(!PageLocked(page
), page
);
5776 if (!do_swap_account
|| !cgroup_subsys_on_dfl(memory_cgrp_subsys
))
5779 memcg
= page
->mem_cgroup
;
5783 for (; memcg
!= root_mem_cgroup
; memcg
= parent_mem_cgroup(memcg
))
5784 if (page_counter_read(&memcg
->swap
) * 2 >= memcg
->swap
.limit
)
5790 /* for remember boot option*/
5791 #ifdef CONFIG_MEMCG_SWAP_ENABLED
5792 static int really_do_swap_account __initdata
= 1;
5794 static int really_do_swap_account __initdata
;
5797 static int __init
enable_swap_account(char *s
)
5799 if (!strcmp(s
, "1"))
5800 really_do_swap_account
= 1;
5801 else if (!strcmp(s
, "0"))
5802 really_do_swap_account
= 0;
5805 __setup("swapaccount=", enable_swap_account
);
5807 static u64
swap_current_read(struct cgroup_subsys_state
*css
,
5810 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
5812 return (u64
)page_counter_read(&memcg
->swap
) * PAGE_SIZE
;
5815 static int swap_max_show(struct seq_file
*m
, void *v
)
5817 struct mem_cgroup
*memcg
= mem_cgroup_from_css(seq_css(m
));
5818 unsigned long max
= READ_ONCE(memcg
->swap
.limit
);
5820 if (max
== PAGE_COUNTER_MAX
)
5821 seq_puts(m
, "max\n");
5823 seq_printf(m
, "%llu\n", (u64
)max
* PAGE_SIZE
);
5828 static ssize_t
swap_max_write(struct kernfs_open_file
*of
,
5829 char *buf
, size_t nbytes
, loff_t off
)
5831 struct mem_cgroup
*memcg
= mem_cgroup_from_css(of_css(of
));
5835 buf
= strstrip(buf
);
5836 err
= page_counter_memparse(buf
, "max", &max
);
5840 mutex_lock(&memcg_limit_mutex
);
5841 err
= page_counter_limit(&memcg
->swap
, max
);
5842 mutex_unlock(&memcg_limit_mutex
);
5849 static struct cftype swap_files
[] = {
5851 .name
= "swap.current",
5852 .flags
= CFTYPE_NOT_ON_ROOT
,
5853 .read_u64
= swap_current_read
,
5857 .flags
= CFTYPE_NOT_ON_ROOT
,
5858 .seq_show
= swap_max_show
,
5859 .write
= swap_max_write
,
5864 static struct cftype memsw_cgroup_files
[] = {
5866 .name
= "memsw.usage_in_bytes",
5867 .private = MEMFILE_PRIVATE(_MEMSWAP
, RES_USAGE
),
5868 .read_u64
= mem_cgroup_read_u64
,
5871 .name
= "memsw.max_usage_in_bytes",
5872 .private = MEMFILE_PRIVATE(_MEMSWAP
, RES_MAX_USAGE
),
5873 .write
= mem_cgroup_reset
,
5874 .read_u64
= mem_cgroup_read_u64
,
5877 .name
= "memsw.limit_in_bytes",
5878 .private = MEMFILE_PRIVATE(_MEMSWAP
, RES_LIMIT
),
5879 .write
= mem_cgroup_write
,
5880 .read_u64
= mem_cgroup_read_u64
,
5883 .name
= "memsw.failcnt",
5884 .private = MEMFILE_PRIVATE(_MEMSWAP
, RES_FAILCNT
),
5885 .write
= mem_cgroup_reset
,
5886 .read_u64
= mem_cgroup_read_u64
,
5888 { }, /* terminate */
5891 static int __init
mem_cgroup_swap_init(void)
5893 if (!mem_cgroup_disabled() && really_do_swap_account
) {
5894 do_swap_account
= 1;
5895 WARN_ON(cgroup_add_dfl_cftypes(&memory_cgrp_subsys
,
5897 WARN_ON(cgroup_add_legacy_cftypes(&memory_cgrp_subsys
,
5898 memsw_cgroup_files
));
5902 subsys_initcall(mem_cgroup_swap_init
);
5904 #endif /* CONFIG_MEMCG_SWAP */