1 /* memcontrol.c - Memory Controller
3 * Copyright IBM Corporation, 2007
4 * Author Balbir Singh <balbir@linux.vnet.ibm.com>
6 * Copyright 2007 OpenVZ SWsoft Inc
7 * Author: Pavel Emelianov <xemul@openvz.org>
10 * Copyright (C) 2009 Nokia Corporation
11 * Author: Kirill A. Shutemov
13 * Kernel Memory Controller
14 * Copyright (C) 2012 Parallels Inc. and Google Inc.
15 * Authors: Glauber Costa and Suleiman Souhlal
18 * Charge lifetime sanitation
19 * Lockless page tracking & accounting
20 * Unified hierarchy configuration model
21 * Copyright (C) 2015 Red Hat, Inc., Johannes Weiner
23 * This program is free software; you can redistribute it and/or modify
24 * it under the terms of the GNU General Public License as published by
25 * the Free Software Foundation; either version 2 of the License, or
26 * (at your option) any later version.
28 * This program is distributed in the hope that it will be useful,
29 * but WITHOUT ANY WARRANTY; without even the implied warranty of
30 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
31 * GNU General Public License for more details.
34 #include <linux/page_counter.h>
35 #include <linux/memcontrol.h>
36 #include <linux/cgroup.h>
38 #include <linux/hugetlb.h>
39 #include <linux/pagemap.h>
40 #include <linux/smp.h>
41 #include <linux/page-flags.h>
42 #include <linux/backing-dev.h>
43 #include <linux/bit_spinlock.h>
44 #include <linux/rcupdate.h>
45 #include <linux/limits.h>
46 #include <linux/export.h>
47 #include <linux/mutex.h>
48 #include <linux/rbtree.h>
49 #include <linux/slab.h>
50 #include <linux/swap.h>
51 #include <linux/swapops.h>
52 #include <linux/spinlock.h>
53 #include <linux/eventfd.h>
54 #include <linux/poll.h>
55 #include <linux/sort.h>
57 #include <linux/seq_file.h>
58 #include <linux/vmpressure.h>
59 #include <linux/mm_inline.h>
60 #include <linux/swap_cgroup.h>
61 #include <linux/cpu.h>
62 #include <linux/oom.h>
63 #include <linux/lockdep.h>
64 #include <linux/file.h>
65 #include <linux/tracehook.h>
69 #include <net/tcp_memcontrol.h>
72 #include <asm/uaccess.h>
74 #include <trace/events/vmscan.h>
76 struct cgroup_subsys memory_cgrp_subsys __read_mostly
;
77 EXPORT_SYMBOL(memory_cgrp_subsys
);
79 struct mem_cgroup
*root_mem_cgroup __read_mostly
;
81 #define MEM_CGROUP_RECLAIM_RETRIES 5
83 /* Socket memory accounting disabled? */
84 static bool cgroup_memory_nosocket
;
86 /* Whether the swap controller is active */
87 #ifdef CONFIG_MEMCG_SWAP
88 int do_swap_account __read_mostly
;
90 #define do_swap_account 0
93 /* Whether legacy memory+swap accounting is active */
94 static bool do_memsw_account(void)
96 return !cgroup_subsys_on_dfl(memory_cgrp_subsys
) && do_swap_account
;
99 static const char * const mem_cgroup_stat_names
[] = {
109 static const char * const mem_cgroup_events_names
[] = {
116 static const char * const mem_cgroup_lru_names
[] = {
124 #define THRESHOLDS_EVENTS_TARGET 128
125 #define SOFTLIMIT_EVENTS_TARGET 1024
126 #define NUMAINFO_EVENTS_TARGET 1024
129 * Cgroups above their limits are maintained in a RB-Tree, independent of
130 * their hierarchy representation
133 struct mem_cgroup_tree_per_zone
{
134 struct rb_root rb_root
;
138 struct mem_cgroup_tree_per_node
{
139 struct mem_cgroup_tree_per_zone rb_tree_per_zone
[MAX_NR_ZONES
];
142 struct mem_cgroup_tree
{
143 struct mem_cgroup_tree_per_node
*rb_tree_per_node
[MAX_NUMNODES
];
146 static struct mem_cgroup_tree soft_limit_tree __read_mostly
;
149 struct mem_cgroup_eventfd_list
{
150 struct list_head list
;
151 struct eventfd_ctx
*eventfd
;
155 * cgroup_event represents events which userspace want to receive.
157 struct mem_cgroup_event
{
159 * memcg which the event belongs to.
161 struct mem_cgroup
*memcg
;
163 * eventfd to signal userspace about the event.
165 struct eventfd_ctx
*eventfd
;
167 * Each of these stored in a list by the cgroup.
169 struct list_head list
;
171 * register_event() callback will be used to add new userspace
172 * waiter for changes related to this event. Use eventfd_signal()
173 * on eventfd to send notification to userspace.
175 int (*register_event
)(struct mem_cgroup
*memcg
,
176 struct eventfd_ctx
*eventfd
, const char *args
);
178 * unregister_event() callback will be called when userspace closes
179 * the eventfd or on cgroup removing. This callback must be set,
180 * if you want provide notification functionality.
182 void (*unregister_event
)(struct mem_cgroup
*memcg
,
183 struct eventfd_ctx
*eventfd
);
185 * All fields below needed to unregister event when
186 * userspace closes eventfd.
189 wait_queue_head_t
*wqh
;
191 struct work_struct remove
;
194 static void mem_cgroup_threshold(struct mem_cgroup
*memcg
);
195 static void mem_cgroup_oom_notify(struct mem_cgroup
*memcg
);
197 /* Stuffs for move charges at task migration. */
199 * Types of charges to be moved.
201 #define MOVE_ANON 0x1U
202 #define MOVE_FILE 0x2U
203 #define MOVE_MASK (MOVE_ANON | MOVE_FILE)
205 /* "mc" and its members are protected by cgroup_mutex */
206 static struct move_charge_struct
{
207 spinlock_t lock
; /* for from, to */
208 struct mem_cgroup
*from
;
209 struct mem_cgroup
*to
;
211 unsigned long precharge
;
212 unsigned long moved_charge
;
213 unsigned long moved_swap
;
214 struct task_struct
*moving_task
; /* a task moving charges */
215 wait_queue_head_t waitq
; /* a waitq for other context */
217 .lock
= __SPIN_LOCK_UNLOCKED(mc
.lock
),
218 .waitq
= __WAIT_QUEUE_HEAD_INITIALIZER(mc
.waitq
),
222 * Maximum loops in mem_cgroup_hierarchical_reclaim(), used for soft
223 * limit reclaim to prevent infinite loops, if they ever occur.
225 #define MEM_CGROUP_MAX_RECLAIM_LOOPS 100
226 #define MEM_CGROUP_MAX_SOFT_LIMIT_RECLAIM_LOOPS 2
229 MEM_CGROUP_CHARGE_TYPE_CACHE
= 0,
230 MEM_CGROUP_CHARGE_TYPE_ANON
,
231 MEM_CGROUP_CHARGE_TYPE_SWAPOUT
, /* for accounting swapcache */
232 MEM_CGROUP_CHARGE_TYPE_DROP
, /* a page was unused swap cache */
236 /* for encoding cft->private value on file */
244 #define MEMFILE_PRIVATE(x, val) ((x) << 16 | (val))
245 #define MEMFILE_TYPE(val) ((val) >> 16 & 0xffff)
246 #define MEMFILE_ATTR(val) ((val) & 0xffff)
247 /* Used for OOM nofiier */
248 #define OOM_CONTROL (0)
251 * The memcg_create_mutex will be held whenever a new cgroup is created.
252 * As a consequence, any change that needs to protect against new child cgroups
253 * appearing has to hold it as well.
255 static DEFINE_MUTEX(memcg_create_mutex
);
257 /* Some nice accessors for the vmpressure. */
258 struct vmpressure
*memcg_to_vmpressure(struct mem_cgroup
*memcg
)
261 memcg
= root_mem_cgroup
;
262 return &memcg
->vmpressure
;
265 struct cgroup_subsys_state
*vmpressure_to_css(struct vmpressure
*vmpr
)
267 return &container_of(vmpr
, struct mem_cgroup
, vmpressure
)->css
;
270 static inline bool mem_cgroup_is_root(struct mem_cgroup
*memcg
)
272 return (memcg
== root_mem_cgroup
);
276 * We restrict the id in the range of [1, 65535], so it can fit into
279 #define MEM_CGROUP_ID_MAX USHRT_MAX
281 static inline unsigned short mem_cgroup_id(struct mem_cgroup
*memcg
)
283 return memcg
->css
.id
;
287 * A helper function to get mem_cgroup from ID. must be called under
288 * rcu_read_lock(). The caller is responsible for calling
289 * css_tryget_online() if the mem_cgroup is used for charging. (dropping
290 * refcnt from swap can be called against removed memcg.)
292 static inline struct mem_cgroup
*mem_cgroup_from_id(unsigned short id
)
294 struct cgroup_subsys_state
*css
;
296 css
= css_from_id(id
, &memory_cgrp_subsys
);
297 return mem_cgroup_from_css(css
);
300 #ifdef CONFIG_MEMCG_KMEM
302 * This will be the memcg's index in each cache's ->memcg_params.memcg_caches.
303 * The main reason for not using cgroup id for this:
304 * this works better in sparse environments, where we have a lot of memcgs,
305 * but only a few kmem-limited. Or also, if we have, for instance, 200
306 * memcgs, and none but the 200th is kmem-limited, we'd have to have a
307 * 200 entry array for that.
309 * The current size of the caches array is stored in memcg_nr_cache_ids. It
310 * will double each time we have to increase it.
312 static DEFINE_IDA(memcg_cache_ida
);
313 int memcg_nr_cache_ids
;
315 /* Protects memcg_nr_cache_ids */
316 static DECLARE_RWSEM(memcg_cache_ids_sem
);
318 void memcg_get_cache_ids(void)
320 down_read(&memcg_cache_ids_sem
);
323 void memcg_put_cache_ids(void)
325 up_read(&memcg_cache_ids_sem
);
329 * MIN_SIZE is different than 1, because we would like to avoid going through
330 * the alloc/free process all the time. In a small machine, 4 kmem-limited
331 * cgroups is a reasonable guess. In the future, it could be a parameter or
332 * tunable, but that is strictly not necessary.
334 * MAX_SIZE should be as large as the number of cgrp_ids. Ideally, we could get
335 * this constant directly from cgroup, but it is understandable that this is
336 * better kept as an internal representation in cgroup.c. In any case, the
337 * cgrp_id space is not getting any smaller, and we don't have to necessarily
338 * increase ours as well if it increases.
340 #define MEMCG_CACHES_MIN_SIZE 4
341 #define MEMCG_CACHES_MAX_SIZE MEM_CGROUP_ID_MAX
344 * A lot of the calls to the cache allocation functions are expected to be
345 * inlined by the compiler. Since the calls to memcg_kmem_get_cache are
346 * conditional to this static branch, we'll have to allow modules that does
347 * kmem_cache_alloc and the such to see this symbol as well
349 DEFINE_STATIC_KEY_FALSE(memcg_kmem_enabled_key
);
350 EXPORT_SYMBOL(memcg_kmem_enabled_key
);
352 #endif /* CONFIG_MEMCG_KMEM */
354 static struct mem_cgroup_per_zone
*
355 mem_cgroup_zone_zoneinfo(struct mem_cgroup
*memcg
, struct zone
*zone
)
357 int nid
= zone_to_nid(zone
);
358 int zid
= zone_idx(zone
);
360 return &memcg
->nodeinfo
[nid
]->zoneinfo
[zid
];
364 * mem_cgroup_css_from_page - css of the memcg associated with a page
365 * @page: page of interest
367 * If memcg is bound to the default hierarchy, css of the memcg associated
368 * with @page is returned. The returned css remains associated with @page
369 * until it is released.
371 * If memcg is bound to a traditional hierarchy, the css of root_mem_cgroup
374 * XXX: The above description of behavior on the default hierarchy isn't
375 * strictly true yet as replace_page_cache_page() can modify the
376 * association before @page is released even on the default hierarchy;
377 * however, the current and planned usages don't mix the the two functions
378 * and replace_page_cache_page() will soon be updated to make the invariant
381 struct cgroup_subsys_state
*mem_cgroup_css_from_page(struct page
*page
)
383 struct mem_cgroup
*memcg
;
385 memcg
= page
->mem_cgroup
;
387 if (!memcg
|| !cgroup_subsys_on_dfl(memory_cgrp_subsys
))
388 memcg
= root_mem_cgroup
;
394 * page_cgroup_ino - return inode number of the memcg a page is charged to
397 * Look up the closest online ancestor of the memory cgroup @page is charged to
398 * and return its inode number or 0 if @page is not charged to any cgroup. It
399 * is safe to call this function without holding a reference to @page.
401 * Note, this function is inherently racy, because there is nothing to prevent
402 * the cgroup inode from getting torn down and potentially reallocated a moment
403 * after page_cgroup_ino() returns, so it only should be used by callers that
404 * do not care (such as procfs interfaces).
406 ino_t
page_cgroup_ino(struct page
*page
)
408 struct mem_cgroup
*memcg
;
409 unsigned long ino
= 0;
412 memcg
= READ_ONCE(page
->mem_cgroup
);
413 while (memcg
&& !(memcg
->css
.flags
& CSS_ONLINE
))
414 memcg
= parent_mem_cgroup(memcg
);
416 ino
= cgroup_ino(memcg
->css
.cgroup
);
421 static struct mem_cgroup_per_zone
*
422 mem_cgroup_page_zoneinfo(struct mem_cgroup
*memcg
, struct page
*page
)
424 int nid
= page_to_nid(page
);
425 int zid
= page_zonenum(page
);
427 return &memcg
->nodeinfo
[nid
]->zoneinfo
[zid
];
430 static struct mem_cgroup_tree_per_zone
*
431 soft_limit_tree_node_zone(int nid
, int zid
)
433 return &soft_limit_tree
.rb_tree_per_node
[nid
]->rb_tree_per_zone
[zid
];
436 static struct mem_cgroup_tree_per_zone
*
437 soft_limit_tree_from_page(struct page
*page
)
439 int nid
= page_to_nid(page
);
440 int zid
= page_zonenum(page
);
442 return &soft_limit_tree
.rb_tree_per_node
[nid
]->rb_tree_per_zone
[zid
];
445 static void __mem_cgroup_insert_exceeded(struct mem_cgroup_per_zone
*mz
,
446 struct mem_cgroup_tree_per_zone
*mctz
,
447 unsigned long new_usage_in_excess
)
449 struct rb_node
**p
= &mctz
->rb_root
.rb_node
;
450 struct rb_node
*parent
= NULL
;
451 struct mem_cgroup_per_zone
*mz_node
;
456 mz
->usage_in_excess
= new_usage_in_excess
;
457 if (!mz
->usage_in_excess
)
461 mz_node
= rb_entry(parent
, struct mem_cgroup_per_zone
,
463 if (mz
->usage_in_excess
< mz_node
->usage_in_excess
)
466 * We can't avoid mem cgroups that are over their soft
467 * limit by the same amount
469 else if (mz
->usage_in_excess
>= mz_node
->usage_in_excess
)
472 rb_link_node(&mz
->tree_node
, parent
, p
);
473 rb_insert_color(&mz
->tree_node
, &mctz
->rb_root
);
477 static void __mem_cgroup_remove_exceeded(struct mem_cgroup_per_zone
*mz
,
478 struct mem_cgroup_tree_per_zone
*mctz
)
482 rb_erase(&mz
->tree_node
, &mctz
->rb_root
);
486 static void mem_cgroup_remove_exceeded(struct mem_cgroup_per_zone
*mz
,
487 struct mem_cgroup_tree_per_zone
*mctz
)
491 spin_lock_irqsave(&mctz
->lock
, flags
);
492 __mem_cgroup_remove_exceeded(mz
, mctz
);
493 spin_unlock_irqrestore(&mctz
->lock
, flags
);
496 static unsigned long soft_limit_excess(struct mem_cgroup
*memcg
)
498 unsigned long nr_pages
= page_counter_read(&memcg
->memory
);
499 unsigned long soft_limit
= READ_ONCE(memcg
->soft_limit
);
500 unsigned long excess
= 0;
502 if (nr_pages
> soft_limit
)
503 excess
= nr_pages
- soft_limit
;
508 static void mem_cgroup_update_tree(struct mem_cgroup
*memcg
, struct page
*page
)
510 unsigned long excess
;
511 struct mem_cgroup_per_zone
*mz
;
512 struct mem_cgroup_tree_per_zone
*mctz
;
514 mctz
= soft_limit_tree_from_page(page
);
516 * Necessary to update all ancestors when hierarchy is used.
517 * because their event counter is not touched.
519 for (; memcg
; memcg
= parent_mem_cgroup(memcg
)) {
520 mz
= mem_cgroup_page_zoneinfo(memcg
, page
);
521 excess
= soft_limit_excess(memcg
);
523 * We have to update the tree if mz is on RB-tree or
524 * mem is over its softlimit.
526 if (excess
|| mz
->on_tree
) {
529 spin_lock_irqsave(&mctz
->lock
, flags
);
530 /* if on-tree, remove it */
532 __mem_cgroup_remove_exceeded(mz
, mctz
);
534 * Insert again. mz->usage_in_excess will be updated.
535 * If excess is 0, no tree ops.
537 __mem_cgroup_insert_exceeded(mz
, mctz
, excess
);
538 spin_unlock_irqrestore(&mctz
->lock
, flags
);
543 static void mem_cgroup_remove_from_trees(struct mem_cgroup
*memcg
)
545 struct mem_cgroup_tree_per_zone
*mctz
;
546 struct mem_cgroup_per_zone
*mz
;
550 for (zid
= 0; zid
< MAX_NR_ZONES
; zid
++) {
551 mz
= &memcg
->nodeinfo
[nid
]->zoneinfo
[zid
];
552 mctz
= soft_limit_tree_node_zone(nid
, zid
);
553 mem_cgroup_remove_exceeded(mz
, mctz
);
558 static struct mem_cgroup_per_zone
*
559 __mem_cgroup_largest_soft_limit_node(struct mem_cgroup_tree_per_zone
*mctz
)
561 struct rb_node
*rightmost
= NULL
;
562 struct mem_cgroup_per_zone
*mz
;
566 rightmost
= rb_last(&mctz
->rb_root
);
568 goto done
; /* Nothing to reclaim from */
570 mz
= rb_entry(rightmost
, struct mem_cgroup_per_zone
, tree_node
);
572 * Remove the node now but someone else can add it back,
573 * we will to add it back at the end of reclaim to its correct
574 * position in the tree.
576 __mem_cgroup_remove_exceeded(mz
, mctz
);
577 if (!soft_limit_excess(mz
->memcg
) ||
578 !css_tryget_online(&mz
->memcg
->css
))
584 static struct mem_cgroup_per_zone
*
585 mem_cgroup_largest_soft_limit_node(struct mem_cgroup_tree_per_zone
*mctz
)
587 struct mem_cgroup_per_zone
*mz
;
589 spin_lock_irq(&mctz
->lock
);
590 mz
= __mem_cgroup_largest_soft_limit_node(mctz
);
591 spin_unlock_irq(&mctz
->lock
);
596 * Return page count for single (non recursive) @memcg.
598 * Implementation Note: reading percpu statistics for memcg.
600 * Both of vmstat[] and percpu_counter has threshold and do periodic
601 * synchronization to implement "quick" read. There are trade-off between
602 * reading cost and precision of value. Then, we may have a chance to implement
603 * a periodic synchronization of counter in memcg's counter.
605 * But this _read() function is used for user interface now. The user accounts
606 * memory usage by memory cgroup and he _always_ requires exact value because
607 * he accounts memory. Even if we provide quick-and-fuzzy read, we always
608 * have to visit all online cpus and make sum. So, for now, unnecessary
609 * synchronization is not implemented. (just implemented for cpu hotplug)
611 * If there are kernel internal actions which can make use of some not-exact
612 * value, and reading all cpu value can be performance bottleneck in some
613 * common workload, threshold and synchronization as vmstat[] should be
617 mem_cgroup_read_stat(struct mem_cgroup
*memcg
, enum mem_cgroup_stat_index idx
)
622 /* Per-cpu values can be negative, use a signed accumulator */
623 for_each_possible_cpu(cpu
)
624 val
+= per_cpu(memcg
->stat
->count
[idx
], cpu
);
626 * Summing races with updates, so val may be negative. Avoid exposing
627 * transient negative values.
634 static unsigned long mem_cgroup_read_events(struct mem_cgroup
*memcg
,
635 enum mem_cgroup_events_index idx
)
637 unsigned long val
= 0;
640 for_each_possible_cpu(cpu
)
641 val
+= per_cpu(memcg
->stat
->events
[idx
], cpu
);
645 static void mem_cgroup_charge_statistics(struct mem_cgroup
*memcg
,
647 bool compound
, int nr_pages
)
650 * Here, RSS means 'mapped anon' and anon's SwapCache. Shmem/tmpfs is
651 * counted as CACHE even if it's on ANON LRU.
654 __this_cpu_add(memcg
->stat
->count
[MEM_CGROUP_STAT_RSS
],
657 __this_cpu_add(memcg
->stat
->count
[MEM_CGROUP_STAT_CACHE
],
661 VM_BUG_ON_PAGE(!PageTransHuge(page
), page
);
662 __this_cpu_add(memcg
->stat
->count
[MEM_CGROUP_STAT_RSS_HUGE
],
666 /* pagein of a big page is an event. So, ignore page size */
668 __this_cpu_inc(memcg
->stat
->events
[MEM_CGROUP_EVENTS_PGPGIN
]);
670 __this_cpu_inc(memcg
->stat
->events
[MEM_CGROUP_EVENTS_PGPGOUT
]);
671 nr_pages
= -nr_pages
; /* for event */
674 __this_cpu_add(memcg
->stat
->nr_page_events
, nr_pages
);
677 static unsigned long mem_cgroup_node_nr_lru_pages(struct mem_cgroup
*memcg
,
679 unsigned int lru_mask
)
681 unsigned long nr
= 0;
684 VM_BUG_ON((unsigned)nid
>= nr_node_ids
);
686 for (zid
= 0; zid
< MAX_NR_ZONES
; zid
++) {
687 struct mem_cgroup_per_zone
*mz
;
691 if (!(BIT(lru
) & lru_mask
))
693 mz
= &memcg
->nodeinfo
[nid
]->zoneinfo
[zid
];
694 nr
+= mz
->lru_size
[lru
];
700 static unsigned long mem_cgroup_nr_lru_pages(struct mem_cgroup
*memcg
,
701 unsigned int lru_mask
)
703 unsigned long nr
= 0;
706 for_each_node_state(nid
, N_MEMORY
)
707 nr
+= mem_cgroup_node_nr_lru_pages(memcg
, nid
, lru_mask
);
711 static bool mem_cgroup_event_ratelimit(struct mem_cgroup
*memcg
,
712 enum mem_cgroup_events_target target
)
714 unsigned long val
, next
;
716 val
= __this_cpu_read(memcg
->stat
->nr_page_events
);
717 next
= __this_cpu_read(memcg
->stat
->targets
[target
]);
718 /* from time_after() in jiffies.h */
719 if ((long)next
- (long)val
< 0) {
721 case MEM_CGROUP_TARGET_THRESH
:
722 next
= val
+ THRESHOLDS_EVENTS_TARGET
;
724 case MEM_CGROUP_TARGET_SOFTLIMIT
:
725 next
= val
+ SOFTLIMIT_EVENTS_TARGET
;
727 case MEM_CGROUP_TARGET_NUMAINFO
:
728 next
= val
+ NUMAINFO_EVENTS_TARGET
;
733 __this_cpu_write(memcg
->stat
->targets
[target
], next
);
740 * Check events in order.
743 static void memcg_check_events(struct mem_cgroup
*memcg
, struct page
*page
)
745 /* threshold event is triggered in finer grain than soft limit */
746 if (unlikely(mem_cgroup_event_ratelimit(memcg
,
747 MEM_CGROUP_TARGET_THRESH
))) {
749 bool do_numainfo __maybe_unused
;
751 do_softlimit
= mem_cgroup_event_ratelimit(memcg
,
752 MEM_CGROUP_TARGET_SOFTLIMIT
);
754 do_numainfo
= mem_cgroup_event_ratelimit(memcg
,
755 MEM_CGROUP_TARGET_NUMAINFO
);
757 mem_cgroup_threshold(memcg
);
758 if (unlikely(do_softlimit
))
759 mem_cgroup_update_tree(memcg
, page
);
761 if (unlikely(do_numainfo
))
762 atomic_inc(&memcg
->numainfo_events
);
767 struct mem_cgroup
*mem_cgroup_from_task(struct task_struct
*p
)
770 * mm_update_next_owner() may clear mm->owner to NULL
771 * if it races with swapoff, page migration, etc.
772 * So this can be called with p == NULL.
777 return mem_cgroup_from_css(task_css(p
, memory_cgrp_id
));
779 EXPORT_SYMBOL(mem_cgroup_from_task
);
781 static struct mem_cgroup
*get_mem_cgroup_from_mm(struct mm_struct
*mm
)
783 struct mem_cgroup
*memcg
= NULL
;
788 * Page cache insertions can happen withou an
789 * actual mm context, e.g. during disk probing
790 * on boot, loopback IO, acct() writes etc.
793 memcg
= root_mem_cgroup
;
795 memcg
= mem_cgroup_from_task(rcu_dereference(mm
->owner
));
796 if (unlikely(!memcg
))
797 memcg
= root_mem_cgroup
;
799 } while (!css_tryget_online(&memcg
->css
));
805 * mem_cgroup_iter - iterate over memory cgroup hierarchy
806 * @root: hierarchy root
807 * @prev: previously returned memcg, NULL on first invocation
808 * @reclaim: cookie for shared reclaim walks, NULL for full walks
810 * Returns references to children of the hierarchy below @root, or
811 * @root itself, or %NULL after a full round-trip.
813 * Caller must pass the return value in @prev on subsequent
814 * invocations for reference counting, or use mem_cgroup_iter_break()
815 * to cancel a hierarchy walk before the round-trip is complete.
817 * Reclaimers can specify a zone and a priority level in @reclaim to
818 * divide up the memcgs in the hierarchy among all concurrent
819 * reclaimers operating on the same zone and priority.
821 struct mem_cgroup
*mem_cgroup_iter(struct mem_cgroup
*root
,
822 struct mem_cgroup
*prev
,
823 struct mem_cgroup_reclaim_cookie
*reclaim
)
825 struct mem_cgroup_reclaim_iter
*uninitialized_var(iter
);
826 struct cgroup_subsys_state
*css
= NULL
;
827 struct mem_cgroup
*memcg
= NULL
;
828 struct mem_cgroup
*pos
= NULL
;
830 if (mem_cgroup_disabled())
834 root
= root_mem_cgroup
;
836 if (prev
&& !reclaim
)
839 if (!root
->use_hierarchy
&& root
!= root_mem_cgroup
) {
848 struct mem_cgroup_per_zone
*mz
;
850 mz
= mem_cgroup_zone_zoneinfo(root
, reclaim
->zone
);
851 iter
= &mz
->iter
[reclaim
->priority
];
853 if (prev
&& reclaim
->generation
!= iter
->generation
)
857 pos
= READ_ONCE(iter
->position
);
858 if (!pos
|| css_tryget(&pos
->css
))
861 * css reference reached zero, so iter->position will
862 * be cleared by ->css_released. However, we should not
863 * rely on this happening soon, because ->css_released
864 * is called from a work queue, and by busy-waiting we
865 * might block it. So we clear iter->position right
868 (void)cmpxchg(&iter
->position
, pos
, NULL
);
876 css
= css_next_descendant_pre(css
, &root
->css
);
879 * Reclaimers share the hierarchy walk, and a
880 * new one might jump in right at the end of
881 * the hierarchy - make sure they see at least
882 * one group and restart from the beginning.
890 * Verify the css and acquire a reference. The root
891 * is provided by the caller, so we know it's alive
892 * and kicking, and don't take an extra reference.
894 memcg
= mem_cgroup_from_css(css
);
896 if (css
== &root
->css
)
899 if (css_tryget(css
)) {
901 * Make sure the memcg is initialized:
902 * mem_cgroup_css_online() orders the the
903 * initialization against setting the flag.
905 if (smp_load_acquire(&memcg
->initialized
))
916 * The position could have already been updated by a competing
917 * thread, so check that the value hasn't changed since we read
918 * it to avoid reclaiming from the same cgroup twice.
920 (void)cmpxchg(&iter
->position
, pos
, memcg
);
928 reclaim
->generation
= iter
->generation
;
934 if (prev
&& prev
!= root
)
941 * mem_cgroup_iter_break - abort a hierarchy walk prematurely
942 * @root: hierarchy root
943 * @prev: last visited hierarchy member as returned by mem_cgroup_iter()
945 void mem_cgroup_iter_break(struct mem_cgroup
*root
,
946 struct mem_cgroup
*prev
)
949 root
= root_mem_cgroup
;
950 if (prev
&& prev
!= root
)
954 static void invalidate_reclaim_iterators(struct mem_cgroup
*dead_memcg
)
956 struct mem_cgroup
*memcg
= dead_memcg
;
957 struct mem_cgroup_reclaim_iter
*iter
;
958 struct mem_cgroup_per_zone
*mz
;
962 while ((memcg
= parent_mem_cgroup(memcg
))) {
964 for (zid
= 0; zid
< MAX_NR_ZONES
; zid
++) {
965 mz
= &memcg
->nodeinfo
[nid
]->zoneinfo
[zid
];
966 for (i
= 0; i
<= DEF_PRIORITY
; i
++) {
968 cmpxchg(&iter
->position
,
977 * Iteration constructs for visiting all cgroups (under a tree). If
978 * loops are exited prematurely (break), mem_cgroup_iter_break() must
979 * be used for reference counting.
981 #define for_each_mem_cgroup_tree(iter, root) \
982 for (iter = mem_cgroup_iter(root, NULL, NULL); \
984 iter = mem_cgroup_iter(root, iter, NULL))
986 #define for_each_mem_cgroup(iter) \
987 for (iter = mem_cgroup_iter(NULL, NULL, NULL); \
989 iter = mem_cgroup_iter(NULL, iter, NULL))
992 * mem_cgroup_zone_lruvec - get the lru list vector for a zone and memcg
993 * @zone: zone of the wanted lruvec
994 * @memcg: memcg of the wanted lruvec
996 * Returns the lru list vector holding pages for the given @zone and
997 * @mem. This can be the global zone lruvec, if the memory controller
1000 struct lruvec
*mem_cgroup_zone_lruvec(struct zone
*zone
,
1001 struct mem_cgroup
*memcg
)
1003 struct mem_cgroup_per_zone
*mz
;
1004 struct lruvec
*lruvec
;
1006 if (mem_cgroup_disabled()) {
1007 lruvec
= &zone
->lruvec
;
1011 mz
= mem_cgroup_zone_zoneinfo(memcg
, zone
);
1012 lruvec
= &mz
->lruvec
;
1015 * Since a node can be onlined after the mem_cgroup was created,
1016 * we have to be prepared to initialize lruvec->zone here;
1017 * and if offlined then reonlined, we need to reinitialize it.
1019 if (unlikely(lruvec
->zone
!= zone
))
1020 lruvec
->zone
= zone
;
1025 * mem_cgroup_page_lruvec - return lruvec for isolating/putting an LRU page
1027 * @zone: zone of the page
1029 * This function is only safe when following the LRU page isolation
1030 * and putback protocol: the LRU lock must be held, and the page must
1031 * either be PageLRU() or the caller must have isolated/allocated it.
1033 struct lruvec
*mem_cgroup_page_lruvec(struct page
*page
, struct zone
*zone
)
1035 struct mem_cgroup_per_zone
*mz
;
1036 struct mem_cgroup
*memcg
;
1037 struct lruvec
*lruvec
;
1039 if (mem_cgroup_disabled()) {
1040 lruvec
= &zone
->lruvec
;
1044 memcg
= page
->mem_cgroup
;
1046 * Swapcache readahead pages are added to the LRU - and
1047 * possibly migrated - before they are charged.
1050 memcg
= root_mem_cgroup
;
1052 mz
= mem_cgroup_page_zoneinfo(memcg
, page
);
1053 lruvec
= &mz
->lruvec
;
1056 * Since a node can be onlined after the mem_cgroup was created,
1057 * we have to be prepared to initialize lruvec->zone here;
1058 * and if offlined then reonlined, we need to reinitialize it.
1060 if (unlikely(lruvec
->zone
!= zone
))
1061 lruvec
->zone
= zone
;
1066 * mem_cgroup_update_lru_size - account for adding or removing an lru page
1067 * @lruvec: mem_cgroup per zone lru vector
1068 * @lru: index of lru list the page is sitting on
1069 * @nr_pages: positive when adding or negative when removing
1071 * This function must be called when a page is added to or removed from an
1074 void mem_cgroup_update_lru_size(struct lruvec
*lruvec
, enum lru_list lru
,
1077 struct mem_cgroup_per_zone
*mz
;
1078 unsigned long *lru_size
;
1080 if (mem_cgroup_disabled())
1083 mz
= container_of(lruvec
, struct mem_cgroup_per_zone
, lruvec
);
1084 lru_size
= mz
->lru_size
+ lru
;
1085 *lru_size
+= nr_pages
;
1086 VM_BUG_ON((long)(*lru_size
) < 0);
1089 bool task_in_mem_cgroup(struct task_struct
*task
, struct mem_cgroup
*memcg
)
1091 struct mem_cgroup
*task_memcg
;
1092 struct task_struct
*p
;
1095 p
= find_lock_task_mm(task
);
1097 task_memcg
= get_mem_cgroup_from_mm(p
->mm
);
1101 * All threads may have already detached their mm's, but the oom
1102 * killer still needs to detect if they have already been oom
1103 * killed to prevent needlessly killing additional tasks.
1106 task_memcg
= mem_cgroup_from_task(task
);
1107 css_get(&task_memcg
->css
);
1110 ret
= mem_cgroup_is_descendant(task_memcg
, memcg
);
1111 css_put(&task_memcg
->css
);
1116 * mem_cgroup_margin - calculate chargeable space of a memory cgroup
1117 * @memcg: the memory cgroup
1119 * Returns the maximum amount of memory @mem can be charged with, in
1122 static unsigned long mem_cgroup_margin(struct mem_cgroup
*memcg
)
1124 unsigned long margin
= 0;
1125 unsigned long count
;
1126 unsigned long limit
;
1128 count
= page_counter_read(&memcg
->memory
);
1129 limit
= READ_ONCE(memcg
->memory
.limit
);
1131 margin
= limit
- count
;
1133 if (do_memsw_account()) {
1134 count
= page_counter_read(&memcg
->memsw
);
1135 limit
= READ_ONCE(memcg
->memsw
.limit
);
1137 margin
= min(margin
, limit
- count
);
1144 * A routine for checking "mem" is under move_account() or not.
1146 * Checking a cgroup is mc.from or mc.to or under hierarchy of
1147 * moving cgroups. This is for waiting at high-memory pressure
1150 static bool mem_cgroup_under_move(struct mem_cgroup
*memcg
)
1152 struct mem_cgroup
*from
;
1153 struct mem_cgroup
*to
;
1156 * Unlike task_move routines, we access mc.to, mc.from not under
1157 * mutual exclusion by cgroup_mutex. Here, we take spinlock instead.
1159 spin_lock(&mc
.lock
);
1165 ret
= mem_cgroup_is_descendant(from
, memcg
) ||
1166 mem_cgroup_is_descendant(to
, memcg
);
1168 spin_unlock(&mc
.lock
);
1172 static bool mem_cgroup_wait_acct_move(struct mem_cgroup
*memcg
)
1174 if (mc
.moving_task
&& current
!= mc
.moving_task
) {
1175 if (mem_cgroup_under_move(memcg
)) {
1177 prepare_to_wait(&mc
.waitq
, &wait
, TASK_INTERRUPTIBLE
);
1178 /* moving charge context might have finished. */
1181 finish_wait(&mc
.waitq
, &wait
);
1188 #define K(x) ((x) << (PAGE_SHIFT-10))
1190 * mem_cgroup_print_oom_info: Print OOM information relevant to memory controller.
1191 * @memcg: The memory cgroup that went over limit
1192 * @p: Task that is going to be killed
1194 * NOTE: @memcg and @p's mem_cgroup can be different when hierarchy is
1197 void mem_cgroup_print_oom_info(struct mem_cgroup
*memcg
, struct task_struct
*p
)
1199 /* oom_info_lock ensures that parallel ooms do not interleave */
1200 static DEFINE_MUTEX(oom_info_lock
);
1201 struct mem_cgroup
*iter
;
1204 mutex_lock(&oom_info_lock
);
1208 pr_info("Task in ");
1209 pr_cont_cgroup_path(task_cgroup(p
, memory_cgrp_id
));
1210 pr_cont(" killed as a result of limit of ");
1212 pr_info("Memory limit reached of cgroup ");
1215 pr_cont_cgroup_path(memcg
->css
.cgroup
);
1220 pr_info("memory: usage %llukB, limit %llukB, failcnt %lu\n",
1221 K((u64
)page_counter_read(&memcg
->memory
)),
1222 K((u64
)memcg
->memory
.limit
), memcg
->memory
.failcnt
);
1223 pr_info("memory+swap: usage %llukB, limit %llukB, failcnt %lu\n",
1224 K((u64
)page_counter_read(&memcg
->memsw
)),
1225 K((u64
)memcg
->memsw
.limit
), memcg
->memsw
.failcnt
);
1226 pr_info("kmem: usage %llukB, limit %llukB, failcnt %lu\n",
1227 K((u64
)page_counter_read(&memcg
->kmem
)),
1228 K((u64
)memcg
->kmem
.limit
), memcg
->kmem
.failcnt
);
1230 for_each_mem_cgroup_tree(iter
, memcg
) {
1231 pr_info("Memory cgroup stats for ");
1232 pr_cont_cgroup_path(iter
->css
.cgroup
);
1235 for (i
= 0; i
< MEM_CGROUP_STAT_NSTATS
; i
++) {
1236 if (i
== MEM_CGROUP_STAT_SWAP
&& !do_memsw_account())
1238 pr_cont(" %s:%luKB", mem_cgroup_stat_names
[i
],
1239 K(mem_cgroup_read_stat(iter
, i
)));
1242 for (i
= 0; i
< NR_LRU_LISTS
; i
++)
1243 pr_cont(" %s:%luKB", mem_cgroup_lru_names
[i
],
1244 K(mem_cgroup_nr_lru_pages(iter
, BIT(i
))));
1248 mutex_unlock(&oom_info_lock
);
1252 * This function returns the number of memcg under hierarchy tree. Returns
1253 * 1(self count) if no children.
1255 static int mem_cgroup_count_children(struct mem_cgroup
*memcg
)
1258 struct mem_cgroup
*iter
;
1260 for_each_mem_cgroup_tree(iter
, memcg
)
1266 * Return the memory (and swap, if configured) limit for a memcg.
1268 static unsigned long mem_cgroup_get_limit(struct mem_cgroup
*memcg
)
1270 unsigned long limit
;
1272 limit
= memcg
->memory
.limit
;
1273 if (mem_cgroup_swappiness(memcg
)) {
1274 unsigned long memsw_limit
;
1276 memsw_limit
= memcg
->memsw
.limit
;
1277 limit
= min(limit
+ total_swap_pages
, memsw_limit
);
1282 static void mem_cgroup_out_of_memory(struct mem_cgroup
*memcg
, gfp_t gfp_mask
,
1285 struct oom_control oc
= {
1288 .gfp_mask
= gfp_mask
,
1291 struct mem_cgroup
*iter
;
1292 unsigned long chosen_points
= 0;
1293 unsigned long totalpages
;
1294 unsigned int points
= 0;
1295 struct task_struct
*chosen
= NULL
;
1297 mutex_lock(&oom_lock
);
1300 * If current has a pending SIGKILL or is exiting, then automatically
1301 * select it. The goal is to allow it to allocate so that it may
1302 * quickly exit and free its memory.
1304 if (fatal_signal_pending(current
) || task_will_free_mem(current
)) {
1305 mark_oom_victim(current
);
1309 check_panic_on_oom(&oc
, CONSTRAINT_MEMCG
, memcg
);
1310 totalpages
= mem_cgroup_get_limit(memcg
) ? : 1;
1311 for_each_mem_cgroup_tree(iter
, memcg
) {
1312 struct css_task_iter it
;
1313 struct task_struct
*task
;
1315 css_task_iter_start(&iter
->css
, &it
);
1316 while ((task
= css_task_iter_next(&it
))) {
1317 switch (oom_scan_process_thread(&oc
, task
, totalpages
)) {
1318 case OOM_SCAN_SELECT
:
1320 put_task_struct(chosen
);
1322 chosen_points
= ULONG_MAX
;
1323 get_task_struct(chosen
);
1325 case OOM_SCAN_CONTINUE
:
1327 case OOM_SCAN_ABORT
:
1328 css_task_iter_end(&it
);
1329 mem_cgroup_iter_break(memcg
, iter
);
1331 put_task_struct(chosen
);
1336 points
= oom_badness(task
, memcg
, NULL
, totalpages
);
1337 if (!points
|| points
< chosen_points
)
1339 /* Prefer thread group leaders for display purposes */
1340 if (points
== chosen_points
&&
1341 thread_group_leader(chosen
))
1345 put_task_struct(chosen
);
1347 chosen_points
= points
;
1348 get_task_struct(chosen
);
1350 css_task_iter_end(&it
);
1354 points
= chosen_points
* 1000 / totalpages
;
1355 oom_kill_process(&oc
, chosen
, points
, totalpages
, memcg
,
1356 "Memory cgroup out of memory");
1359 mutex_unlock(&oom_lock
);
1362 #if MAX_NUMNODES > 1
1365 * test_mem_cgroup_node_reclaimable
1366 * @memcg: the target memcg
1367 * @nid: the node ID to be checked.
1368 * @noswap : specify true here if the user wants flle only information.
1370 * This function returns whether the specified memcg contains any
1371 * reclaimable pages on a node. Returns true if there are any reclaimable
1372 * pages in the node.
1374 static bool test_mem_cgroup_node_reclaimable(struct mem_cgroup
*memcg
,
1375 int nid
, bool noswap
)
1377 if (mem_cgroup_node_nr_lru_pages(memcg
, nid
, LRU_ALL_FILE
))
1379 if (noswap
|| !total_swap_pages
)
1381 if (mem_cgroup_node_nr_lru_pages(memcg
, nid
, LRU_ALL_ANON
))
1388 * Always updating the nodemask is not very good - even if we have an empty
1389 * list or the wrong list here, we can start from some node and traverse all
1390 * nodes based on the zonelist. So update the list loosely once per 10 secs.
1393 static void mem_cgroup_may_update_nodemask(struct mem_cgroup
*memcg
)
1397 * numainfo_events > 0 means there was at least NUMAINFO_EVENTS_TARGET
1398 * pagein/pageout changes since the last update.
1400 if (!atomic_read(&memcg
->numainfo_events
))
1402 if (atomic_inc_return(&memcg
->numainfo_updating
) > 1)
1405 /* make a nodemask where this memcg uses memory from */
1406 memcg
->scan_nodes
= node_states
[N_MEMORY
];
1408 for_each_node_mask(nid
, node_states
[N_MEMORY
]) {
1410 if (!test_mem_cgroup_node_reclaimable(memcg
, nid
, false))
1411 node_clear(nid
, memcg
->scan_nodes
);
1414 atomic_set(&memcg
->numainfo_events
, 0);
1415 atomic_set(&memcg
->numainfo_updating
, 0);
1419 * Selecting a node where we start reclaim from. Because what we need is just
1420 * reducing usage counter, start from anywhere is O,K. Considering
1421 * memory reclaim from current node, there are pros. and cons.
1423 * Freeing memory from current node means freeing memory from a node which
1424 * we'll use or we've used. So, it may make LRU bad. And if several threads
1425 * hit limits, it will see a contention on a node. But freeing from remote
1426 * node means more costs for memory reclaim because of memory latency.
1428 * Now, we use round-robin. Better algorithm is welcomed.
1430 int mem_cgroup_select_victim_node(struct mem_cgroup
*memcg
)
1434 mem_cgroup_may_update_nodemask(memcg
);
1435 node
= memcg
->last_scanned_node
;
1437 node
= next_node(node
, memcg
->scan_nodes
);
1438 if (node
== MAX_NUMNODES
)
1439 node
= first_node(memcg
->scan_nodes
);
1441 * We call this when we hit limit, not when pages are added to LRU.
1442 * No LRU may hold pages because all pages are UNEVICTABLE or
1443 * memcg is too small and all pages are not on LRU. In that case,
1444 * we use curret node.
1446 if (unlikely(node
== MAX_NUMNODES
))
1447 node
= numa_node_id();
1449 memcg
->last_scanned_node
= node
;
1453 int mem_cgroup_select_victim_node(struct mem_cgroup
*memcg
)
1459 static int mem_cgroup_soft_reclaim(struct mem_cgroup
*root_memcg
,
1462 unsigned long *total_scanned
)
1464 struct mem_cgroup
*victim
= NULL
;
1467 unsigned long excess
;
1468 unsigned long nr_scanned
;
1469 struct mem_cgroup_reclaim_cookie reclaim
= {
1474 excess
= soft_limit_excess(root_memcg
);
1477 victim
= mem_cgroup_iter(root_memcg
, victim
, &reclaim
);
1482 * If we have not been able to reclaim
1483 * anything, it might because there are
1484 * no reclaimable pages under this hierarchy
1489 * We want to do more targeted reclaim.
1490 * excess >> 2 is not to excessive so as to
1491 * reclaim too much, nor too less that we keep
1492 * coming back to reclaim from this cgroup
1494 if (total
>= (excess
>> 2) ||
1495 (loop
> MEM_CGROUP_MAX_RECLAIM_LOOPS
))
1500 total
+= mem_cgroup_shrink_node_zone(victim
, gfp_mask
, false,
1502 *total_scanned
+= nr_scanned
;
1503 if (!soft_limit_excess(root_memcg
))
1506 mem_cgroup_iter_break(root_memcg
, victim
);
1510 #ifdef CONFIG_LOCKDEP
1511 static struct lockdep_map memcg_oom_lock_dep_map
= {
1512 .name
= "memcg_oom_lock",
1516 static DEFINE_SPINLOCK(memcg_oom_lock
);
1519 * Check OOM-Killer is already running under our hierarchy.
1520 * If someone is running, return false.
1522 static bool mem_cgroup_oom_trylock(struct mem_cgroup
*memcg
)
1524 struct mem_cgroup
*iter
, *failed
= NULL
;
1526 spin_lock(&memcg_oom_lock
);
1528 for_each_mem_cgroup_tree(iter
, memcg
) {
1529 if (iter
->oom_lock
) {
1531 * this subtree of our hierarchy is already locked
1532 * so we cannot give a lock.
1535 mem_cgroup_iter_break(memcg
, iter
);
1538 iter
->oom_lock
= true;
1543 * OK, we failed to lock the whole subtree so we have
1544 * to clean up what we set up to the failing subtree
1546 for_each_mem_cgroup_tree(iter
, memcg
) {
1547 if (iter
== failed
) {
1548 mem_cgroup_iter_break(memcg
, iter
);
1551 iter
->oom_lock
= false;
1554 mutex_acquire(&memcg_oom_lock_dep_map
, 0, 1, _RET_IP_
);
1556 spin_unlock(&memcg_oom_lock
);
1561 static void mem_cgroup_oom_unlock(struct mem_cgroup
*memcg
)
1563 struct mem_cgroup
*iter
;
1565 spin_lock(&memcg_oom_lock
);
1566 mutex_release(&memcg_oom_lock_dep_map
, 1, _RET_IP_
);
1567 for_each_mem_cgroup_tree(iter
, memcg
)
1568 iter
->oom_lock
= false;
1569 spin_unlock(&memcg_oom_lock
);
1572 static void mem_cgroup_mark_under_oom(struct mem_cgroup
*memcg
)
1574 struct mem_cgroup
*iter
;
1576 spin_lock(&memcg_oom_lock
);
1577 for_each_mem_cgroup_tree(iter
, memcg
)
1579 spin_unlock(&memcg_oom_lock
);
1582 static void mem_cgroup_unmark_under_oom(struct mem_cgroup
*memcg
)
1584 struct mem_cgroup
*iter
;
1587 * When a new child is created while the hierarchy is under oom,
1588 * mem_cgroup_oom_lock() may not be called. Watch for underflow.
1590 spin_lock(&memcg_oom_lock
);
1591 for_each_mem_cgroup_tree(iter
, memcg
)
1592 if (iter
->under_oom
> 0)
1594 spin_unlock(&memcg_oom_lock
);
1597 static DECLARE_WAIT_QUEUE_HEAD(memcg_oom_waitq
);
1599 struct oom_wait_info
{
1600 struct mem_cgroup
*memcg
;
1604 static int memcg_oom_wake_function(wait_queue_t
*wait
,
1605 unsigned mode
, int sync
, void *arg
)
1607 struct mem_cgroup
*wake_memcg
= (struct mem_cgroup
*)arg
;
1608 struct mem_cgroup
*oom_wait_memcg
;
1609 struct oom_wait_info
*oom_wait_info
;
1611 oom_wait_info
= container_of(wait
, struct oom_wait_info
, wait
);
1612 oom_wait_memcg
= oom_wait_info
->memcg
;
1614 if (!mem_cgroup_is_descendant(wake_memcg
, oom_wait_memcg
) &&
1615 !mem_cgroup_is_descendant(oom_wait_memcg
, wake_memcg
))
1617 return autoremove_wake_function(wait
, mode
, sync
, arg
);
1620 static void memcg_oom_recover(struct mem_cgroup
*memcg
)
1623 * For the following lockless ->under_oom test, the only required
1624 * guarantee is that it must see the state asserted by an OOM when
1625 * this function is called as a result of userland actions
1626 * triggered by the notification of the OOM. This is trivially
1627 * achieved by invoking mem_cgroup_mark_under_oom() before
1628 * triggering notification.
1630 if (memcg
&& memcg
->under_oom
)
1631 __wake_up(&memcg_oom_waitq
, TASK_NORMAL
, 0, memcg
);
1634 static void mem_cgroup_oom(struct mem_cgroup
*memcg
, gfp_t mask
, int order
)
1636 if (!current
->memcg_may_oom
)
1639 * We are in the middle of the charge context here, so we
1640 * don't want to block when potentially sitting on a callstack
1641 * that holds all kinds of filesystem and mm locks.
1643 * Also, the caller may handle a failed allocation gracefully
1644 * (like optional page cache readahead) and so an OOM killer
1645 * invocation might not even be necessary.
1647 * That's why we don't do anything here except remember the
1648 * OOM context and then deal with it at the end of the page
1649 * fault when the stack is unwound, the locks are released,
1650 * and when we know whether the fault was overall successful.
1652 css_get(&memcg
->css
);
1653 current
->memcg_in_oom
= memcg
;
1654 current
->memcg_oom_gfp_mask
= mask
;
1655 current
->memcg_oom_order
= order
;
1659 * mem_cgroup_oom_synchronize - complete memcg OOM handling
1660 * @handle: actually kill/wait or just clean up the OOM state
1662 * This has to be called at the end of a page fault if the memcg OOM
1663 * handler was enabled.
1665 * Memcg supports userspace OOM handling where failed allocations must
1666 * sleep on a waitqueue until the userspace task resolves the
1667 * situation. Sleeping directly in the charge context with all kinds
1668 * of locks held is not a good idea, instead we remember an OOM state
1669 * in the task and mem_cgroup_oom_synchronize() has to be called at
1670 * the end of the page fault to complete the OOM handling.
1672 * Returns %true if an ongoing memcg OOM situation was detected and
1673 * completed, %false otherwise.
1675 bool mem_cgroup_oom_synchronize(bool handle
)
1677 struct mem_cgroup
*memcg
= current
->memcg_in_oom
;
1678 struct oom_wait_info owait
;
1681 /* OOM is global, do not handle */
1685 if (!handle
|| oom_killer_disabled
)
1688 owait
.memcg
= memcg
;
1689 owait
.wait
.flags
= 0;
1690 owait
.wait
.func
= memcg_oom_wake_function
;
1691 owait
.wait
.private = current
;
1692 INIT_LIST_HEAD(&owait
.wait
.task_list
);
1694 prepare_to_wait(&memcg_oom_waitq
, &owait
.wait
, TASK_KILLABLE
);
1695 mem_cgroup_mark_under_oom(memcg
);
1697 locked
= mem_cgroup_oom_trylock(memcg
);
1700 mem_cgroup_oom_notify(memcg
);
1702 if (locked
&& !memcg
->oom_kill_disable
) {
1703 mem_cgroup_unmark_under_oom(memcg
);
1704 finish_wait(&memcg_oom_waitq
, &owait
.wait
);
1705 mem_cgroup_out_of_memory(memcg
, current
->memcg_oom_gfp_mask
,
1706 current
->memcg_oom_order
);
1709 mem_cgroup_unmark_under_oom(memcg
);
1710 finish_wait(&memcg_oom_waitq
, &owait
.wait
);
1714 mem_cgroup_oom_unlock(memcg
);
1716 * There is no guarantee that an OOM-lock contender
1717 * sees the wakeups triggered by the OOM kill
1718 * uncharges. Wake any sleepers explicitely.
1720 memcg_oom_recover(memcg
);
1723 current
->memcg_in_oom
= NULL
;
1724 css_put(&memcg
->css
);
1729 * mem_cgroup_begin_page_stat - begin a page state statistics transaction
1730 * @page: page that is going to change accounted state
1732 * This function must mark the beginning of an accounted page state
1733 * change to prevent double accounting when the page is concurrently
1734 * being moved to another memcg:
1736 * memcg = mem_cgroup_begin_page_stat(page);
1737 * if (TestClearPageState(page))
1738 * mem_cgroup_update_page_stat(memcg, state, -1);
1739 * mem_cgroup_end_page_stat(memcg);
1741 struct mem_cgroup
*mem_cgroup_begin_page_stat(struct page
*page
)
1743 struct mem_cgroup
*memcg
;
1744 unsigned long flags
;
1747 * The RCU lock is held throughout the transaction. The fast
1748 * path can get away without acquiring the memcg->move_lock
1749 * because page moving starts with an RCU grace period.
1751 * The RCU lock also protects the memcg from being freed when
1752 * the page state that is going to change is the only thing
1753 * preventing the page from being uncharged.
1754 * E.g. end-writeback clearing PageWriteback(), which allows
1755 * migration to go ahead and uncharge the page before the
1756 * account transaction might be complete.
1760 if (mem_cgroup_disabled())
1763 memcg
= page
->mem_cgroup
;
1764 if (unlikely(!memcg
))
1767 if (atomic_read(&memcg
->moving_account
) <= 0)
1770 spin_lock_irqsave(&memcg
->move_lock
, flags
);
1771 if (memcg
!= page
->mem_cgroup
) {
1772 spin_unlock_irqrestore(&memcg
->move_lock
, flags
);
1777 * When charge migration first begins, we can have locked and
1778 * unlocked page stat updates happening concurrently. Track
1779 * the task who has the lock for mem_cgroup_end_page_stat().
1781 memcg
->move_lock_task
= current
;
1782 memcg
->move_lock_flags
= flags
;
1786 EXPORT_SYMBOL(mem_cgroup_begin_page_stat
);
1789 * mem_cgroup_end_page_stat - finish a page state statistics transaction
1790 * @memcg: the memcg that was accounted against
1792 void mem_cgroup_end_page_stat(struct mem_cgroup
*memcg
)
1794 if (memcg
&& memcg
->move_lock_task
== current
) {
1795 unsigned long flags
= memcg
->move_lock_flags
;
1797 memcg
->move_lock_task
= NULL
;
1798 memcg
->move_lock_flags
= 0;
1800 spin_unlock_irqrestore(&memcg
->move_lock
, flags
);
1805 EXPORT_SYMBOL(mem_cgroup_end_page_stat
);
1808 * size of first charge trial. "32" comes from vmscan.c's magic value.
1809 * TODO: maybe necessary to use big numbers in big irons.
1811 #define CHARGE_BATCH 32U
1812 struct memcg_stock_pcp
{
1813 struct mem_cgroup
*cached
; /* this never be root cgroup */
1814 unsigned int nr_pages
;
1815 struct work_struct work
;
1816 unsigned long flags
;
1817 #define FLUSHING_CACHED_CHARGE 0
1819 static DEFINE_PER_CPU(struct memcg_stock_pcp
, memcg_stock
);
1820 static DEFINE_MUTEX(percpu_charge_mutex
);
1823 * consume_stock: Try to consume stocked charge on this cpu.
1824 * @memcg: memcg to consume from.
1825 * @nr_pages: how many pages to charge.
1827 * The charges will only happen if @memcg matches the current cpu's memcg
1828 * stock, and at least @nr_pages are available in that stock. Failure to
1829 * service an allocation will refill the stock.
1831 * returns true if successful, false otherwise.
1833 static bool consume_stock(struct mem_cgroup
*memcg
, unsigned int nr_pages
)
1835 struct memcg_stock_pcp
*stock
;
1838 if (nr_pages
> CHARGE_BATCH
)
1841 stock
= &get_cpu_var(memcg_stock
);
1842 if (memcg
== stock
->cached
&& stock
->nr_pages
>= nr_pages
) {
1843 stock
->nr_pages
-= nr_pages
;
1846 put_cpu_var(memcg_stock
);
1851 * Returns stocks cached in percpu and reset cached information.
1853 static void drain_stock(struct memcg_stock_pcp
*stock
)
1855 struct mem_cgroup
*old
= stock
->cached
;
1857 if (stock
->nr_pages
) {
1858 page_counter_uncharge(&old
->memory
, stock
->nr_pages
);
1859 if (do_memsw_account())
1860 page_counter_uncharge(&old
->memsw
, stock
->nr_pages
);
1861 css_put_many(&old
->css
, stock
->nr_pages
);
1862 stock
->nr_pages
= 0;
1864 stock
->cached
= NULL
;
1868 * This must be called under preempt disabled or must be called by
1869 * a thread which is pinned to local cpu.
1871 static void drain_local_stock(struct work_struct
*dummy
)
1873 struct memcg_stock_pcp
*stock
= this_cpu_ptr(&memcg_stock
);
1875 clear_bit(FLUSHING_CACHED_CHARGE
, &stock
->flags
);
1879 * Cache charges(val) to local per_cpu area.
1880 * This will be consumed by consume_stock() function, later.
1882 static void refill_stock(struct mem_cgroup
*memcg
, unsigned int nr_pages
)
1884 struct memcg_stock_pcp
*stock
= &get_cpu_var(memcg_stock
);
1886 if (stock
->cached
!= memcg
) { /* reset if necessary */
1888 stock
->cached
= memcg
;
1890 stock
->nr_pages
+= nr_pages
;
1891 put_cpu_var(memcg_stock
);
1895 * Drains all per-CPU charge caches for given root_memcg resp. subtree
1896 * of the hierarchy under it.
1898 static void drain_all_stock(struct mem_cgroup
*root_memcg
)
1902 /* If someone's already draining, avoid adding running more workers. */
1903 if (!mutex_trylock(&percpu_charge_mutex
))
1905 /* Notify other cpus that system-wide "drain" is running */
1908 for_each_online_cpu(cpu
) {
1909 struct memcg_stock_pcp
*stock
= &per_cpu(memcg_stock
, cpu
);
1910 struct mem_cgroup
*memcg
;
1912 memcg
= stock
->cached
;
1913 if (!memcg
|| !stock
->nr_pages
)
1915 if (!mem_cgroup_is_descendant(memcg
, root_memcg
))
1917 if (!test_and_set_bit(FLUSHING_CACHED_CHARGE
, &stock
->flags
)) {
1919 drain_local_stock(&stock
->work
);
1921 schedule_work_on(cpu
, &stock
->work
);
1926 mutex_unlock(&percpu_charge_mutex
);
1929 static int memcg_cpu_hotplug_callback(struct notifier_block
*nb
,
1930 unsigned long action
,
1933 int cpu
= (unsigned long)hcpu
;
1934 struct memcg_stock_pcp
*stock
;
1936 if (action
== CPU_ONLINE
)
1939 if (action
!= CPU_DEAD
&& action
!= CPU_DEAD_FROZEN
)
1942 stock
= &per_cpu(memcg_stock
, cpu
);
1947 static void reclaim_high(struct mem_cgroup
*memcg
,
1948 unsigned int nr_pages
,
1952 if (page_counter_read(&memcg
->memory
) <= memcg
->high
)
1954 mem_cgroup_events(memcg
, MEMCG_HIGH
, 1);
1955 try_to_free_mem_cgroup_pages(memcg
, nr_pages
, gfp_mask
, true);
1956 } while ((memcg
= parent_mem_cgroup(memcg
)));
1959 static void high_work_func(struct work_struct
*work
)
1961 struct mem_cgroup
*memcg
;
1963 memcg
= container_of(work
, struct mem_cgroup
, high_work
);
1964 reclaim_high(memcg
, CHARGE_BATCH
, GFP_KERNEL
);
1968 * Scheduled by try_charge() to be executed from the userland return path
1969 * and reclaims memory over the high limit.
1971 void mem_cgroup_handle_over_high(void)
1973 unsigned int nr_pages
= current
->memcg_nr_pages_over_high
;
1974 struct mem_cgroup
*memcg
;
1976 if (likely(!nr_pages
))
1979 memcg
= get_mem_cgroup_from_mm(current
->mm
);
1980 reclaim_high(memcg
, nr_pages
, GFP_KERNEL
);
1981 css_put(&memcg
->css
);
1982 current
->memcg_nr_pages_over_high
= 0;
1985 static int try_charge(struct mem_cgroup
*memcg
, gfp_t gfp_mask
,
1986 unsigned int nr_pages
)
1988 unsigned int batch
= max(CHARGE_BATCH
, nr_pages
);
1989 int nr_retries
= MEM_CGROUP_RECLAIM_RETRIES
;
1990 struct mem_cgroup
*mem_over_limit
;
1991 struct page_counter
*counter
;
1992 unsigned long nr_reclaimed
;
1993 bool may_swap
= true;
1994 bool drained
= false;
1996 if (mem_cgroup_is_root(memcg
))
1999 if (consume_stock(memcg
, nr_pages
))
2002 if (!do_memsw_account() ||
2003 page_counter_try_charge(&memcg
->memsw
, batch
, &counter
)) {
2004 if (page_counter_try_charge(&memcg
->memory
, batch
, &counter
))
2006 if (do_memsw_account())
2007 page_counter_uncharge(&memcg
->memsw
, batch
);
2008 mem_over_limit
= mem_cgroup_from_counter(counter
, memory
);
2010 mem_over_limit
= mem_cgroup_from_counter(counter
, memsw
);
2014 if (batch
> nr_pages
) {
2020 * Unlike in global OOM situations, memcg is not in a physical
2021 * memory shortage. Allow dying and OOM-killed tasks to
2022 * bypass the last charges so that they can exit quickly and
2023 * free their memory.
2025 if (unlikely(test_thread_flag(TIF_MEMDIE
) ||
2026 fatal_signal_pending(current
) ||
2027 current
->flags
& PF_EXITING
))
2030 if (unlikely(task_in_memcg_oom(current
)))
2033 if (!gfpflags_allow_blocking(gfp_mask
))
2036 mem_cgroup_events(mem_over_limit
, MEMCG_MAX
, 1);
2038 nr_reclaimed
= try_to_free_mem_cgroup_pages(mem_over_limit
, nr_pages
,
2039 gfp_mask
, may_swap
);
2041 if (mem_cgroup_margin(mem_over_limit
) >= nr_pages
)
2045 drain_all_stock(mem_over_limit
);
2050 if (gfp_mask
& __GFP_NORETRY
)
2053 * Even though the limit is exceeded at this point, reclaim
2054 * may have been able to free some pages. Retry the charge
2055 * before killing the task.
2057 * Only for regular pages, though: huge pages are rather
2058 * unlikely to succeed so close to the limit, and we fall back
2059 * to regular pages anyway in case of failure.
2061 if (nr_reclaimed
&& nr_pages
<= (1 << PAGE_ALLOC_COSTLY_ORDER
))
2064 * At task move, charge accounts can be doubly counted. So, it's
2065 * better to wait until the end of task_move if something is going on.
2067 if (mem_cgroup_wait_acct_move(mem_over_limit
))
2073 if (gfp_mask
& __GFP_NOFAIL
)
2076 if (fatal_signal_pending(current
))
2079 mem_cgroup_events(mem_over_limit
, MEMCG_OOM
, 1);
2081 mem_cgroup_oom(mem_over_limit
, gfp_mask
,
2082 get_order(nr_pages
* PAGE_SIZE
));
2084 if (!(gfp_mask
& __GFP_NOFAIL
))
2088 * The allocation either can't fail or will lead to more memory
2089 * being freed very soon. Allow memory usage go over the limit
2090 * temporarily by force charging it.
2092 page_counter_charge(&memcg
->memory
, nr_pages
);
2093 if (do_memsw_account())
2094 page_counter_charge(&memcg
->memsw
, nr_pages
);
2095 css_get_many(&memcg
->css
, nr_pages
);
2100 css_get_many(&memcg
->css
, batch
);
2101 if (batch
> nr_pages
)
2102 refill_stock(memcg
, batch
- nr_pages
);
2105 * If the hierarchy is above the normal consumption range, schedule
2106 * reclaim on returning to userland. We can perform reclaim here
2107 * if __GFP_RECLAIM but let's always punt for simplicity and so that
2108 * GFP_KERNEL can consistently be used during reclaim. @memcg is
2109 * not recorded as it most likely matches current's and won't
2110 * change in the meantime. As high limit is checked again before
2111 * reclaim, the cost of mismatch is negligible.
2114 if (page_counter_read(&memcg
->memory
) > memcg
->high
) {
2115 /* Don't bother a random interrupted task */
2116 if (in_interrupt()) {
2117 schedule_work(&memcg
->high_work
);
2120 current
->memcg_nr_pages_over_high
+= batch
;
2121 set_notify_resume(current
);
2124 } while ((memcg
= parent_mem_cgroup(memcg
)));
2129 static void cancel_charge(struct mem_cgroup
*memcg
, unsigned int nr_pages
)
2131 if (mem_cgroup_is_root(memcg
))
2134 page_counter_uncharge(&memcg
->memory
, nr_pages
);
2135 if (do_memsw_account())
2136 page_counter_uncharge(&memcg
->memsw
, nr_pages
);
2138 css_put_many(&memcg
->css
, nr_pages
);
2141 static void lock_page_lru(struct page
*page
, int *isolated
)
2143 struct zone
*zone
= page_zone(page
);
2145 spin_lock_irq(&zone
->lru_lock
);
2146 if (PageLRU(page
)) {
2147 struct lruvec
*lruvec
;
2149 lruvec
= mem_cgroup_page_lruvec(page
, zone
);
2151 del_page_from_lru_list(page
, lruvec
, page_lru(page
));
2157 static void unlock_page_lru(struct page
*page
, int isolated
)
2159 struct zone
*zone
= page_zone(page
);
2162 struct lruvec
*lruvec
;
2164 lruvec
= mem_cgroup_page_lruvec(page
, zone
);
2165 VM_BUG_ON_PAGE(PageLRU(page
), page
);
2167 add_page_to_lru_list(page
, lruvec
, page_lru(page
));
2169 spin_unlock_irq(&zone
->lru_lock
);
2172 static void commit_charge(struct page
*page
, struct mem_cgroup
*memcg
,
2177 VM_BUG_ON_PAGE(page
->mem_cgroup
, page
);
2180 * In some cases, SwapCache and FUSE(splice_buf->radixtree), the page
2181 * may already be on some other mem_cgroup's LRU. Take care of it.
2184 lock_page_lru(page
, &isolated
);
2187 * Nobody should be changing or seriously looking at
2188 * page->mem_cgroup at this point:
2190 * - the page is uncharged
2192 * - the page is off-LRU
2194 * - an anonymous fault has exclusive page access, except for
2195 * a locked page table
2197 * - a page cache insertion, a swapin fault, or a migration
2198 * have the page locked
2200 page
->mem_cgroup
= memcg
;
2203 unlock_page_lru(page
, isolated
);
2206 #ifdef CONFIG_MEMCG_KMEM
2207 static int memcg_alloc_cache_id(void)
2212 id
= ida_simple_get(&memcg_cache_ida
,
2213 0, MEMCG_CACHES_MAX_SIZE
, GFP_KERNEL
);
2217 if (id
< memcg_nr_cache_ids
)
2221 * There's no space for the new id in memcg_caches arrays,
2222 * so we have to grow them.
2224 down_write(&memcg_cache_ids_sem
);
2226 size
= 2 * (id
+ 1);
2227 if (size
< MEMCG_CACHES_MIN_SIZE
)
2228 size
= MEMCG_CACHES_MIN_SIZE
;
2229 else if (size
> MEMCG_CACHES_MAX_SIZE
)
2230 size
= MEMCG_CACHES_MAX_SIZE
;
2232 err
= memcg_update_all_caches(size
);
2234 err
= memcg_update_all_list_lrus(size
);
2236 memcg_nr_cache_ids
= size
;
2238 up_write(&memcg_cache_ids_sem
);
2241 ida_simple_remove(&memcg_cache_ida
, id
);
2247 static void memcg_free_cache_id(int id
)
2249 ida_simple_remove(&memcg_cache_ida
, id
);
2252 struct memcg_kmem_cache_create_work
{
2253 struct mem_cgroup
*memcg
;
2254 struct kmem_cache
*cachep
;
2255 struct work_struct work
;
2258 static void memcg_kmem_cache_create_func(struct work_struct
*w
)
2260 struct memcg_kmem_cache_create_work
*cw
=
2261 container_of(w
, struct memcg_kmem_cache_create_work
, work
);
2262 struct mem_cgroup
*memcg
= cw
->memcg
;
2263 struct kmem_cache
*cachep
= cw
->cachep
;
2265 memcg_create_kmem_cache(memcg
, cachep
);
2267 css_put(&memcg
->css
);
2272 * Enqueue the creation of a per-memcg kmem_cache.
2274 static void __memcg_schedule_kmem_cache_create(struct mem_cgroup
*memcg
,
2275 struct kmem_cache
*cachep
)
2277 struct memcg_kmem_cache_create_work
*cw
;
2279 cw
= kmalloc(sizeof(*cw
), GFP_NOWAIT
);
2283 css_get(&memcg
->css
);
2286 cw
->cachep
= cachep
;
2287 INIT_WORK(&cw
->work
, memcg_kmem_cache_create_func
);
2289 schedule_work(&cw
->work
);
2292 static void memcg_schedule_kmem_cache_create(struct mem_cgroup
*memcg
,
2293 struct kmem_cache
*cachep
)
2296 * We need to stop accounting when we kmalloc, because if the
2297 * corresponding kmalloc cache is not yet created, the first allocation
2298 * in __memcg_schedule_kmem_cache_create will recurse.
2300 * However, it is better to enclose the whole function. Depending on
2301 * the debugging options enabled, INIT_WORK(), for instance, can
2302 * trigger an allocation. This too, will make us recurse. Because at
2303 * this point we can't allow ourselves back into memcg_kmem_get_cache,
2304 * the safest choice is to do it like this, wrapping the whole function.
2306 current
->memcg_kmem_skip_account
= 1;
2307 __memcg_schedule_kmem_cache_create(memcg
, cachep
);
2308 current
->memcg_kmem_skip_account
= 0;
2312 * Return the kmem_cache we're supposed to use for a slab allocation.
2313 * We try to use the current memcg's version of the cache.
2315 * If the cache does not exist yet, if we are the first user of it,
2316 * we either create it immediately, if possible, or create it asynchronously
2318 * In the latter case, we will let the current allocation go through with
2319 * the original cache.
2321 * Can't be called in interrupt context or from kernel threads.
2322 * This function needs to be called with rcu_read_lock() held.
2324 struct kmem_cache
*__memcg_kmem_get_cache(struct kmem_cache
*cachep
, gfp_t gfp
)
2326 struct mem_cgroup
*memcg
;
2327 struct kmem_cache
*memcg_cachep
;
2330 VM_BUG_ON(!is_root_cache(cachep
));
2332 if (cachep
->flags
& SLAB_ACCOUNT
)
2333 gfp
|= __GFP_ACCOUNT
;
2335 if (!(gfp
& __GFP_ACCOUNT
))
2338 if (current
->memcg_kmem_skip_account
)
2341 memcg
= get_mem_cgroup_from_mm(current
->mm
);
2342 kmemcg_id
= READ_ONCE(memcg
->kmemcg_id
);
2346 memcg_cachep
= cache_from_memcg_idx(cachep
, kmemcg_id
);
2347 if (likely(memcg_cachep
))
2348 return memcg_cachep
;
2351 * If we are in a safe context (can wait, and not in interrupt
2352 * context), we could be be predictable and return right away.
2353 * This would guarantee that the allocation being performed
2354 * already belongs in the new cache.
2356 * However, there are some clashes that can arrive from locking.
2357 * For instance, because we acquire the slab_mutex while doing
2358 * memcg_create_kmem_cache, this means no further allocation
2359 * could happen with the slab_mutex held. So it's better to
2362 memcg_schedule_kmem_cache_create(memcg
, cachep
);
2364 css_put(&memcg
->css
);
2368 void __memcg_kmem_put_cache(struct kmem_cache
*cachep
)
2370 if (!is_root_cache(cachep
))
2371 css_put(&cachep
->memcg_params
.memcg
->css
);
2374 int __memcg_kmem_charge_memcg(struct page
*page
, gfp_t gfp
, int order
,
2375 struct mem_cgroup
*memcg
)
2377 unsigned int nr_pages
= 1 << order
;
2378 struct page_counter
*counter
;
2381 if (!memcg_kmem_is_active(memcg
))
2384 if (!page_counter_try_charge(&memcg
->kmem
, nr_pages
, &counter
))
2387 ret
= try_charge(memcg
, gfp
, nr_pages
);
2389 page_counter_uncharge(&memcg
->kmem
, nr_pages
);
2393 page
->mem_cgroup
= memcg
;
2398 int __memcg_kmem_charge(struct page
*page
, gfp_t gfp
, int order
)
2400 struct mem_cgroup
*memcg
;
2403 memcg
= get_mem_cgroup_from_mm(current
->mm
);
2404 ret
= __memcg_kmem_charge_memcg(page
, gfp
, order
, memcg
);
2405 css_put(&memcg
->css
);
2409 void __memcg_kmem_uncharge(struct page
*page
, int order
)
2411 struct mem_cgroup
*memcg
= page
->mem_cgroup
;
2412 unsigned int nr_pages
= 1 << order
;
2417 VM_BUG_ON_PAGE(mem_cgroup_is_root(memcg
), page
);
2419 page_counter_uncharge(&memcg
->kmem
, nr_pages
);
2420 page_counter_uncharge(&memcg
->memory
, nr_pages
);
2421 if (do_memsw_account())
2422 page_counter_uncharge(&memcg
->memsw
, nr_pages
);
2424 page
->mem_cgroup
= NULL
;
2425 css_put_many(&memcg
->css
, nr_pages
);
2427 #endif /* CONFIG_MEMCG_KMEM */
2429 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
2432 * Because tail pages are not marked as "used", set it. We're under
2433 * zone->lru_lock and migration entries setup in all page mappings.
2435 void mem_cgroup_split_huge_fixup(struct page
*head
)
2439 if (mem_cgroup_disabled())
2442 for (i
= 1; i
< HPAGE_PMD_NR
; i
++)
2443 head
[i
].mem_cgroup
= head
->mem_cgroup
;
2445 __this_cpu_sub(head
->mem_cgroup
->stat
->count
[MEM_CGROUP_STAT_RSS_HUGE
],
2448 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
2450 #ifdef CONFIG_MEMCG_SWAP
2451 static void mem_cgroup_swap_statistics(struct mem_cgroup
*memcg
,
2454 int val
= (charge
) ? 1 : -1;
2455 this_cpu_add(memcg
->stat
->count
[MEM_CGROUP_STAT_SWAP
], val
);
2459 * mem_cgroup_move_swap_account - move swap charge and swap_cgroup's record.
2460 * @entry: swap entry to be moved
2461 * @from: mem_cgroup which the entry is moved from
2462 * @to: mem_cgroup which the entry is moved to
2464 * It succeeds only when the swap_cgroup's record for this entry is the same
2465 * as the mem_cgroup's id of @from.
2467 * Returns 0 on success, -EINVAL on failure.
2469 * The caller must have charged to @to, IOW, called page_counter_charge() about
2470 * both res and memsw, and called css_get().
2472 static int mem_cgroup_move_swap_account(swp_entry_t entry
,
2473 struct mem_cgroup
*from
, struct mem_cgroup
*to
)
2475 unsigned short old_id
, new_id
;
2477 old_id
= mem_cgroup_id(from
);
2478 new_id
= mem_cgroup_id(to
);
2480 if (swap_cgroup_cmpxchg(entry
, old_id
, new_id
) == old_id
) {
2481 mem_cgroup_swap_statistics(from
, false);
2482 mem_cgroup_swap_statistics(to
, true);
2488 static inline int mem_cgroup_move_swap_account(swp_entry_t entry
,
2489 struct mem_cgroup
*from
, struct mem_cgroup
*to
)
2495 static DEFINE_MUTEX(memcg_limit_mutex
);
2497 static int mem_cgroup_resize_limit(struct mem_cgroup
*memcg
,
2498 unsigned long limit
)
2500 unsigned long curusage
;
2501 unsigned long oldusage
;
2502 bool enlarge
= false;
2507 * For keeping hierarchical_reclaim simple, how long we should retry
2508 * is depends on callers. We set our retry-count to be function
2509 * of # of children which we should visit in this loop.
2511 retry_count
= MEM_CGROUP_RECLAIM_RETRIES
*
2512 mem_cgroup_count_children(memcg
);
2514 oldusage
= page_counter_read(&memcg
->memory
);
2517 if (signal_pending(current
)) {
2522 mutex_lock(&memcg_limit_mutex
);
2523 if (limit
> memcg
->memsw
.limit
) {
2524 mutex_unlock(&memcg_limit_mutex
);
2528 if (limit
> memcg
->memory
.limit
)
2530 ret
= page_counter_limit(&memcg
->memory
, limit
);
2531 mutex_unlock(&memcg_limit_mutex
);
2536 try_to_free_mem_cgroup_pages(memcg
, 1, GFP_KERNEL
, true);
2538 curusage
= page_counter_read(&memcg
->memory
);
2539 /* Usage is reduced ? */
2540 if (curusage
>= oldusage
)
2543 oldusage
= curusage
;
2544 } while (retry_count
);
2546 if (!ret
&& enlarge
)
2547 memcg_oom_recover(memcg
);
2552 static int mem_cgroup_resize_memsw_limit(struct mem_cgroup
*memcg
,
2553 unsigned long limit
)
2555 unsigned long curusage
;
2556 unsigned long oldusage
;
2557 bool enlarge
= false;
2561 /* see mem_cgroup_resize_res_limit */
2562 retry_count
= MEM_CGROUP_RECLAIM_RETRIES
*
2563 mem_cgroup_count_children(memcg
);
2565 oldusage
= page_counter_read(&memcg
->memsw
);
2568 if (signal_pending(current
)) {
2573 mutex_lock(&memcg_limit_mutex
);
2574 if (limit
< memcg
->memory
.limit
) {
2575 mutex_unlock(&memcg_limit_mutex
);
2579 if (limit
> memcg
->memsw
.limit
)
2581 ret
= page_counter_limit(&memcg
->memsw
, limit
);
2582 mutex_unlock(&memcg_limit_mutex
);
2587 try_to_free_mem_cgroup_pages(memcg
, 1, GFP_KERNEL
, false);
2589 curusage
= page_counter_read(&memcg
->memsw
);
2590 /* Usage is reduced ? */
2591 if (curusage
>= oldusage
)
2594 oldusage
= curusage
;
2595 } while (retry_count
);
2597 if (!ret
&& enlarge
)
2598 memcg_oom_recover(memcg
);
2603 unsigned long mem_cgroup_soft_limit_reclaim(struct zone
*zone
, int order
,
2605 unsigned long *total_scanned
)
2607 unsigned long nr_reclaimed
= 0;
2608 struct mem_cgroup_per_zone
*mz
, *next_mz
= NULL
;
2609 unsigned long reclaimed
;
2611 struct mem_cgroup_tree_per_zone
*mctz
;
2612 unsigned long excess
;
2613 unsigned long nr_scanned
;
2618 mctz
= soft_limit_tree_node_zone(zone_to_nid(zone
), zone_idx(zone
));
2620 * This loop can run a while, specially if mem_cgroup's continuously
2621 * keep exceeding their soft limit and putting the system under
2628 mz
= mem_cgroup_largest_soft_limit_node(mctz
);
2633 reclaimed
= mem_cgroup_soft_reclaim(mz
->memcg
, zone
,
2634 gfp_mask
, &nr_scanned
);
2635 nr_reclaimed
+= reclaimed
;
2636 *total_scanned
+= nr_scanned
;
2637 spin_lock_irq(&mctz
->lock
);
2638 __mem_cgroup_remove_exceeded(mz
, mctz
);
2641 * If we failed to reclaim anything from this memory cgroup
2642 * it is time to move on to the next cgroup
2646 next_mz
= __mem_cgroup_largest_soft_limit_node(mctz
);
2648 excess
= soft_limit_excess(mz
->memcg
);
2650 * One school of thought says that we should not add
2651 * back the node to the tree if reclaim returns 0.
2652 * But our reclaim could return 0, simply because due
2653 * to priority we are exposing a smaller subset of
2654 * memory to reclaim from. Consider this as a longer
2657 /* If excess == 0, no tree ops */
2658 __mem_cgroup_insert_exceeded(mz
, mctz
, excess
);
2659 spin_unlock_irq(&mctz
->lock
);
2660 css_put(&mz
->memcg
->css
);
2663 * Could not reclaim anything and there are no more
2664 * mem cgroups to try or we seem to be looping without
2665 * reclaiming anything.
2667 if (!nr_reclaimed
&&
2669 loop
> MEM_CGROUP_MAX_SOFT_LIMIT_RECLAIM_LOOPS
))
2671 } while (!nr_reclaimed
);
2673 css_put(&next_mz
->memcg
->css
);
2674 return nr_reclaimed
;
2678 * Test whether @memcg has children, dead or alive. Note that this
2679 * function doesn't care whether @memcg has use_hierarchy enabled and
2680 * returns %true if there are child csses according to the cgroup
2681 * hierarchy. Testing use_hierarchy is the caller's responsiblity.
2683 static inline bool memcg_has_children(struct mem_cgroup
*memcg
)
2688 * The lock does not prevent addition or deletion of children, but
2689 * it prevents a new child from being initialized based on this
2690 * parent in css_online(), so it's enough to decide whether
2691 * hierarchically inherited attributes can still be changed or not.
2693 lockdep_assert_held(&memcg_create_mutex
);
2696 ret
= css_next_child(NULL
, &memcg
->css
);
2702 * Reclaims as many pages from the given memcg as possible and moves
2703 * the rest to the parent.
2705 * Caller is responsible for holding css reference for memcg.
2707 static int mem_cgroup_force_empty(struct mem_cgroup
*memcg
)
2709 int nr_retries
= MEM_CGROUP_RECLAIM_RETRIES
;
2711 /* we call try-to-free pages for make this cgroup empty */
2712 lru_add_drain_all();
2713 /* try to free all pages in this cgroup */
2714 while (nr_retries
&& page_counter_read(&memcg
->memory
)) {
2717 if (signal_pending(current
))
2720 progress
= try_to_free_mem_cgroup_pages(memcg
, 1,
2724 /* maybe some writeback is necessary */
2725 congestion_wait(BLK_RW_ASYNC
, HZ
/10);
2733 static ssize_t
mem_cgroup_force_empty_write(struct kernfs_open_file
*of
,
2734 char *buf
, size_t nbytes
,
2737 struct mem_cgroup
*memcg
= mem_cgroup_from_css(of_css(of
));
2739 if (mem_cgroup_is_root(memcg
))
2741 return mem_cgroup_force_empty(memcg
) ?: nbytes
;
2744 static u64
mem_cgroup_hierarchy_read(struct cgroup_subsys_state
*css
,
2747 return mem_cgroup_from_css(css
)->use_hierarchy
;
2750 static int mem_cgroup_hierarchy_write(struct cgroup_subsys_state
*css
,
2751 struct cftype
*cft
, u64 val
)
2754 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
2755 struct mem_cgroup
*parent_memcg
= mem_cgroup_from_css(memcg
->css
.parent
);
2757 mutex_lock(&memcg_create_mutex
);
2759 if (memcg
->use_hierarchy
== val
)
2763 * If parent's use_hierarchy is set, we can't make any modifications
2764 * in the child subtrees. If it is unset, then the change can
2765 * occur, provided the current cgroup has no children.
2767 * For the root cgroup, parent_mem is NULL, we allow value to be
2768 * set if there are no children.
2770 if ((!parent_memcg
|| !parent_memcg
->use_hierarchy
) &&
2771 (val
== 1 || val
== 0)) {
2772 if (!memcg_has_children(memcg
))
2773 memcg
->use_hierarchy
= val
;
2780 mutex_unlock(&memcg_create_mutex
);
2785 static unsigned long tree_stat(struct mem_cgroup
*memcg
,
2786 enum mem_cgroup_stat_index idx
)
2788 struct mem_cgroup
*iter
;
2789 unsigned long val
= 0;
2791 for_each_mem_cgroup_tree(iter
, memcg
)
2792 val
+= mem_cgroup_read_stat(iter
, idx
);
2797 static unsigned long mem_cgroup_usage(struct mem_cgroup
*memcg
, bool swap
)
2801 if (mem_cgroup_is_root(memcg
)) {
2802 val
= tree_stat(memcg
, MEM_CGROUP_STAT_CACHE
);
2803 val
+= tree_stat(memcg
, MEM_CGROUP_STAT_RSS
);
2805 val
+= tree_stat(memcg
, MEM_CGROUP_STAT_SWAP
);
2808 val
= page_counter_read(&memcg
->memory
);
2810 val
= page_counter_read(&memcg
->memsw
);
2823 static u64
mem_cgroup_read_u64(struct cgroup_subsys_state
*css
,
2826 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
2827 struct page_counter
*counter
;
2829 switch (MEMFILE_TYPE(cft
->private)) {
2831 counter
= &memcg
->memory
;
2834 counter
= &memcg
->memsw
;
2837 counter
= &memcg
->kmem
;
2843 switch (MEMFILE_ATTR(cft
->private)) {
2845 if (counter
== &memcg
->memory
)
2846 return (u64
)mem_cgroup_usage(memcg
, false) * PAGE_SIZE
;
2847 if (counter
== &memcg
->memsw
)
2848 return (u64
)mem_cgroup_usage(memcg
, true) * PAGE_SIZE
;
2849 return (u64
)page_counter_read(counter
) * PAGE_SIZE
;
2851 return (u64
)counter
->limit
* PAGE_SIZE
;
2853 return (u64
)counter
->watermark
* PAGE_SIZE
;
2855 return counter
->failcnt
;
2856 case RES_SOFT_LIMIT
:
2857 return (u64
)memcg
->soft_limit
* PAGE_SIZE
;
2863 #ifdef CONFIG_MEMCG_KMEM
2864 static int memcg_activate_kmem(struct mem_cgroup
*memcg
,
2865 unsigned long nr_pages
)
2870 BUG_ON(memcg
->kmemcg_id
>= 0);
2871 BUG_ON(memcg
->kmem_acct_activated
);
2872 BUG_ON(memcg
->kmem_acct_active
);
2875 * For simplicity, we won't allow this to be disabled. It also can't
2876 * be changed if the cgroup has children already, or if tasks had
2879 * If tasks join before we set the limit, a person looking at
2880 * kmem.usage_in_bytes will have no way to determine when it took
2881 * place, which makes the value quite meaningless.
2883 * After it first became limited, changes in the value of the limit are
2884 * of course permitted.
2886 mutex_lock(&memcg_create_mutex
);
2887 if (cgroup_is_populated(memcg
->css
.cgroup
) ||
2888 (memcg
->use_hierarchy
&& memcg_has_children(memcg
)))
2890 mutex_unlock(&memcg_create_mutex
);
2894 memcg_id
= memcg_alloc_cache_id();
2901 * We couldn't have accounted to this cgroup, because it hasn't got
2902 * activated yet, so this should succeed.
2904 err
= page_counter_limit(&memcg
->kmem
, nr_pages
);
2907 static_branch_inc(&memcg_kmem_enabled_key
);
2909 * A memory cgroup is considered kmem-active as soon as it gets
2910 * kmemcg_id. Setting the id after enabling static branching will
2911 * guarantee no one starts accounting before all call sites are
2914 memcg
->kmemcg_id
= memcg_id
;
2915 memcg
->kmem_acct_activated
= true;
2916 memcg
->kmem_acct_active
= true;
2921 static int memcg_update_kmem_limit(struct mem_cgroup
*memcg
,
2922 unsigned long limit
)
2926 mutex_lock(&memcg_limit_mutex
);
2927 if (!memcg_kmem_is_active(memcg
))
2928 ret
= memcg_activate_kmem(memcg
, limit
);
2930 ret
= page_counter_limit(&memcg
->kmem
, limit
);
2931 mutex_unlock(&memcg_limit_mutex
);
2935 static int memcg_propagate_kmem(struct mem_cgroup
*memcg
)
2938 struct mem_cgroup
*parent
= parent_mem_cgroup(memcg
);
2943 mutex_lock(&memcg_limit_mutex
);
2945 * If the parent cgroup is not kmem-active now, it cannot be activated
2946 * after this point, because it has at least one child already.
2948 if (memcg_kmem_is_active(parent
))
2949 ret
= memcg_activate_kmem(memcg
, PAGE_COUNTER_MAX
);
2950 mutex_unlock(&memcg_limit_mutex
);
2954 static int memcg_update_kmem_limit(struct mem_cgroup
*memcg
,
2955 unsigned long limit
)
2959 #endif /* CONFIG_MEMCG_KMEM */
2962 * The user of this function is...
2965 static ssize_t
mem_cgroup_write(struct kernfs_open_file
*of
,
2966 char *buf
, size_t nbytes
, loff_t off
)
2968 struct mem_cgroup
*memcg
= mem_cgroup_from_css(of_css(of
));
2969 unsigned long nr_pages
;
2972 buf
= strstrip(buf
);
2973 ret
= page_counter_memparse(buf
, "-1", &nr_pages
);
2977 switch (MEMFILE_ATTR(of_cft(of
)->private)) {
2979 if (mem_cgroup_is_root(memcg
)) { /* Can't set limit on root */
2983 switch (MEMFILE_TYPE(of_cft(of
)->private)) {
2985 ret
= mem_cgroup_resize_limit(memcg
, nr_pages
);
2988 ret
= mem_cgroup_resize_memsw_limit(memcg
, nr_pages
);
2991 ret
= memcg_update_kmem_limit(memcg
, nr_pages
);
2995 case RES_SOFT_LIMIT
:
2996 memcg
->soft_limit
= nr_pages
;
3000 return ret
?: nbytes
;
3003 static ssize_t
mem_cgroup_reset(struct kernfs_open_file
*of
, char *buf
,
3004 size_t nbytes
, loff_t off
)
3006 struct mem_cgroup
*memcg
= mem_cgroup_from_css(of_css(of
));
3007 struct page_counter
*counter
;
3009 switch (MEMFILE_TYPE(of_cft(of
)->private)) {
3011 counter
= &memcg
->memory
;
3014 counter
= &memcg
->memsw
;
3017 counter
= &memcg
->kmem
;
3023 switch (MEMFILE_ATTR(of_cft(of
)->private)) {
3025 page_counter_reset_watermark(counter
);
3028 counter
->failcnt
= 0;
3037 static u64
mem_cgroup_move_charge_read(struct cgroup_subsys_state
*css
,
3040 return mem_cgroup_from_css(css
)->move_charge_at_immigrate
;
3044 static int mem_cgroup_move_charge_write(struct cgroup_subsys_state
*css
,
3045 struct cftype
*cft
, u64 val
)
3047 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
3049 if (val
& ~MOVE_MASK
)
3053 * No kind of locking is needed in here, because ->can_attach() will
3054 * check this value once in the beginning of the process, and then carry
3055 * on with stale data. This means that changes to this value will only
3056 * affect task migrations starting after the change.
3058 memcg
->move_charge_at_immigrate
= val
;
3062 static int mem_cgroup_move_charge_write(struct cgroup_subsys_state
*css
,
3063 struct cftype
*cft
, u64 val
)
3070 static int memcg_numa_stat_show(struct seq_file
*m
, void *v
)
3074 unsigned int lru_mask
;
3077 static const struct numa_stat stats
[] = {
3078 { "total", LRU_ALL
},
3079 { "file", LRU_ALL_FILE
},
3080 { "anon", LRU_ALL_ANON
},
3081 { "unevictable", BIT(LRU_UNEVICTABLE
) },
3083 const struct numa_stat
*stat
;
3086 struct mem_cgroup
*memcg
= mem_cgroup_from_css(seq_css(m
));
3088 for (stat
= stats
; stat
< stats
+ ARRAY_SIZE(stats
); stat
++) {
3089 nr
= mem_cgroup_nr_lru_pages(memcg
, stat
->lru_mask
);
3090 seq_printf(m
, "%s=%lu", stat
->name
, nr
);
3091 for_each_node_state(nid
, N_MEMORY
) {
3092 nr
= mem_cgroup_node_nr_lru_pages(memcg
, nid
,
3094 seq_printf(m
, " N%d=%lu", nid
, nr
);
3099 for (stat
= stats
; stat
< stats
+ ARRAY_SIZE(stats
); stat
++) {
3100 struct mem_cgroup
*iter
;
3103 for_each_mem_cgroup_tree(iter
, memcg
)
3104 nr
+= mem_cgroup_nr_lru_pages(iter
, stat
->lru_mask
);
3105 seq_printf(m
, "hierarchical_%s=%lu", stat
->name
, nr
);
3106 for_each_node_state(nid
, N_MEMORY
) {
3108 for_each_mem_cgroup_tree(iter
, memcg
)
3109 nr
+= mem_cgroup_node_nr_lru_pages(
3110 iter
, nid
, stat
->lru_mask
);
3111 seq_printf(m
, " N%d=%lu", nid
, nr
);
3118 #endif /* CONFIG_NUMA */
3120 static int memcg_stat_show(struct seq_file
*m
, void *v
)
3122 struct mem_cgroup
*memcg
= mem_cgroup_from_css(seq_css(m
));
3123 unsigned long memory
, memsw
;
3124 struct mem_cgroup
*mi
;
3127 BUILD_BUG_ON(ARRAY_SIZE(mem_cgroup_stat_names
) !=
3128 MEM_CGROUP_STAT_NSTATS
);
3129 BUILD_BUG_ON(ARRAY_SIZE(mem_cgroup_events_names
) !=
3130 MEM_CGROUP_EVENTS_NSTATS
);
3131 BUILD_BUG_ON(ARRAY_SIZE(mem_cgroup_lru_names
) != NR_LRU_LISTS
);
3133 for (i
= 0; i
< MEM_CGROUP_STAT_NSTATS
; i
++) {
3134 if (i
== MEM_CGROUP_STAT_SWAP
&& !do_memsw_account())
3136 seq_printf(m
, "%s %lu\n", mem_cgroup_stat_names
[i
],
3137 mem_cgroup_read_stat(memcg
, i
) * PAGE_SIZE
);
3140 for (i
= 0; i
< MEM_CGROUP_EVENTS_NSTATS
; i
++)
3141 seq_printf(m
, "%s %lu\n", mem_cgroup_events_names
[i
],
3142 mem_cgroup_read_events(memcg
, i
));
3144 for (i
= 0; i
< NR_LRU_LISTS
; i
++)
3145 seq_printf(m
, "%s %lu\n", mem_cgroup_lru_names
[i
],
3146 mem_cgroup_nr_lru_pages(memcg
, BIT(i
)) * PAGE_SIZE
);
3148 /* Hierarchical information */
3149 memory
= memsw
= PAGE_COUNTER_MAX
;
3150 for (mi
= memcg
; mi
; mi
= parent_mem_cgroup(mi
)) {
3151 memory
= min(memory
, mi
->memory
.limit
);
3152 memsw
= min(memsw
, mi
->memsw
.limit
);
3154 seq_printf(m
, "hierarchical_memory_limit %llu\n",
3155 (u64
)memory
* PAGE_SIZE
);
3156 if (do_memsw_account())
3157 seq_printf(m
, "hierarchical_memsw_limit %llu\n",
3158 (u64
)memsw
* PAGE_SIZE
);
3160 for (i
= 0; i
< MEM_CGROUP_STAT_NSTATS
; i
++) {
3161 unsigned long long val
= 0;
3163 if (i
== MEM_CGROUP_STAT_SWAP
&& !do_memsw_account())
3165 for_each_mem_cgroup_tree(mi
, memcg
)
3166 val
+= mem_cgroup_read_stat(mi
, i
) * PAGE_SIZE
;
3167 seq_printf(m
, "total_%s %llu\n", mem_cgroup_stat_names
[i
], val
);
3170 for (i
= 0; i
< MEM_CGROUP_EVENTS_NSTATS
; i
++) {
3171 unsigned long long val
= 0;
3173 for_each_mem_cgroup_tree(mi
, memcg
)
3174 val
+= mem_cgroup_read_events(mi
, i
);
3175 seq_printf(m
, "total_%s %llu\n",
3176 mem_cgroup_events_names
[i
], val
);
3179 for (i
= 0; i
< NR_LRU_LISTS
; i
++) {
3180 unsigned long long val
= 0;
3182 for_each_mem_cgroup_tree(mi
, memcg
)
3183 val
+= mem_cgroup_nr_lru_pages(mi
, BIT(i
)) * PAGE_SIZE
;
3184 seq_printf(m
, "total_%s %llu\n", mem_cgroup_lru_names
[i
], val
);
3187 #ifdef CONFIG_DEBUG_VM
3190 struct mem_cgroup_per_zone
*mz
;
3191 struct zone_reclaim_stat
*rstat
;
3192 unsigned long recent_rotated
[2] = {0, 0};
3193 unsigned long recent_scanned
[2] = {0, 0};
3195 for_each_online_node(nid
)
3196 for (zid
= 0; zid
< MAX_NR_ZONES
; zid
++) {
3197 mz
= &memcg
->nodeinfo
[nid
]->zoneinfo
[zid
];
3198 rstat
= &mz
->lruvec
.reclaim_stat
;
3200 recent_rotated
[0] += rstat
->recent_rotated
[0];
3201 recent_rotated
[1] += rstat
->recent_rotated
[1];
3202 recent_scanned
[0] += rstat
->recent_scanned
[0];
3203 recent_scanned
[1] += rstat
->recent_scanned
[1];
3205 seq_printf(m
, "recent_rotated_anon %lu\n", recent_rotated
[0]);
3206 seq_printf(m
, "recent_rotated_file %lu\n", recent_rotated
[1]);
3207 seq_printf(m
, "recent_scanned_anon %lu\n", recent_scanned
[0]);
3208 seq_printf(m
, "recent_scanned_file %lu\n", recent_scanned
[1]);
3215 static u64
mem_cgroup_swappiness_read(struct cgroup_subsys_state
*css
,
3218 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
3220 return mem_cgroup_swappiness(memcg
);
3223 static int mem_cgroup_swappiness_write(struct cgroup_subsys_state
*css
,
3224 struct cftype
*cft
, u64 val
)
3226 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
3232 memcg
->swappiness
= val
;
3234 vm_swappiness
= val
;
3239 static void __mem_cgroup_threshold(struct mem_cgroup
*memcg
, bool swap
)
3241 struct mem_cgroup_threshold_ary
*t
;
3242 unsigned long usage
;
3247 t
= rcu_dereference(memcg
->thresholds
.primary
);
3249 t
= rcu_dereference(memcg
->memsw_thresholds
.primary
);
3254 usage
= mem_cgroup_usage(memcg
, swap
);
3257 * current_threshold points to threshold just below or equal to usage.
3258 * If it's not true, a threshold was crossed after last
3259 * call of __mem_cgroup_threshold().
3261 i
= t
->current_threshold
;
3264 * Iterate backward over array of thresholds starting from
3265 * current_threshold and check if a threshold is crossed.
3266 * If none of thresholds below usage is crossed, we read
3267 * only one element of the array here.
3269 for (; i
>= 0 && unlikely(t
->entries
[i
].threshold
> usage
); i
--)
3270 eventfd_signal(t
->entries
[i
].eventfd
, 1);
3272 /* i = current_threshold + 1 */
3276 * Iterate forward over array of thresholds starting from
3277 * current_threshold+1 and check if a threshold is crossed.
3278 * If none of thresholds above usage is crossed, we read
3279 * only one element of the array here.
3281 for (; i
< t
->size
&& unlikely(t
->entries
[i
].threshold
<= usage
); i
++)
3282 eventfd_signal(t
->entries
[i
].eventfd
, 1);
3284 /* Update current_threshold */
3285 t
->current_threshold
= i
- 1;
3290 static void mem_cgroup_threshold(struct mem_cgroup
*memcg
)
3293 __mem_cgroup_threshold(memcg
, false);
3294 if (do_memsw_account())
3295 __mem_cgroup_threshold(memcg
, true);
3297 memcg
= parent_mem_cgroup(memcg
);
3301 static int compare_thresholds(const void *a
, const void *b
)
3303 const struct mem_cgroup_threshold
*_a
= a
;
3304 const struct mem_cgroup_threshold
*_b
= b
;
3306 if (_a
->threshold
> _b
->threshold
)
3309 if (_a
->threshold
< _b
->threshold
)
3315 static int mem_cgroup_oom_notify_cb(struct mem_cgroup
*memcg
)
3317 struct mem_cgroup_eventfd_list
*ev
;
3319 spin_lock(&memcg_oom_lock
);
3321 list_for_each_entry(ev
, &memcg
->oom_notify
, list
)
3322 eventfd_signal(ev
->eventfd
, 1);
3324 spin_unlock(&memcg_oom_lock
);
3328 static void mem_cgroup_oom_notify(struct mem_cgroup
*memcg
)
3330 struct mem_cgroup
*iter
;
3332 for_each_mem_cgroup_tree(iter
, memcg
)
3333 mem_cgroup_oom_notify_cb(iter
);
3336 static int __mem_cgroup_usage_register_event(struct mem_cgroup
*memcg
,
3337 struct eventfd_ctx
*eventfd
, const char *args
, enum res_type type
)
3339 struct mem_cgroup_thresholds
*thresholds
;
3340 struct mem_cgroup_threshold_ary
*new;
3341 unsigned long threshold
;
3342 unsigned long usage
;
3345 ret
= page_counter_memparse(args
, "-1", &threshold
);
3349 mutex_lock(&memcg
->thresholds_lock
);
3352 thresholds
= &memcg
->thresholds
;
3353 usage
= mem_cgroup_usage(memcg
, false);
3354 } else if (type
== _MEMSWAP
) {
3355 thresholds
= &memcg
->memsw_thresholds
;
3356 usage
= mem_cgroup_usage(memcg
, true);
3360 /* Check if a threshold crossed before adding a new one */
3361 if (thresholds
->primary
)
3362 __mem_cgroup_threshold(memcg
, type
== _MEMSWAP
);
3364 size
= thresholds
->primary
? thresholds
->primary
->size
+ 1 : 1;
3366 /* Allocate memory for new array of thresholds */
3367 new = kmalloc(sizeof(*new) + size
* sizeof(struct mem_cgroup_threshold
),
3375 /* Copy thresholds (if any) to new array */
3376 if (thresholds
->primary
) {
3377 memcpy(new->entries
, thresholds
->primary
->entries
, (size
- 1) *
3378 sizeof(struct mem_cgroup_threshold
));
3381 /* Add new threshold */
3382 new->entries
[size
- 1].eventfd
= eventfd
;
3383 new->entries
[size
- 1].threshold
= threshold
;
3385 /* Sort thresholds. Registering of new threshold isn't time-critical */
3386 sort(new->entries
, size
, sizeof(struct mem_cgroup_threshold
),
3387 compare_thresholds
, NULL
);
3389 /* Find current threshold */
3390 new->current_threshold
= -1;
3391 for (i
= 0; i
< size
; i
++) {
3392 if (new->entries
[i
].threshold
<= usage
) {
3394 * new->current_threshold will not be used until
3395 * rcu_assign_pointer(), so it's safe to increment
3398 ++new->current_threshold
;
3403 /* Free old spare buffer and save old primary buffer as spare */
3404 kfree(thresholds
->spare
);
3405 thresholds
->spare
= thresholds
->primary
;
3407 rcu_assign_pointer(thresholds
->primary
, new);
3409 /* To be sure that nobody uses thresholds */
3413 mutex_unlock(&memcg
->thresholds_lock
);
3418 static int mem_cgroup_usage_register_event(struct mem_cgroup
*memcg
,
3419 struct eventfd_ctx
*eventfd
, const char *args
)
3421 return __mem_cgroup_usage_register_event(memcg
, eventfd
, args
, _MEM
);
3424 static int memsw_cgroup_usage_register_event(struct mem_cgroup
*memcg
,
3425 struct eventfd_ctx
*eventfd
, const char *args
)
3427 return __mem_cgroup_usage_register_event(memcg
, eventfd
, args
, _MEMSWAP
);
3430 static void __mem_cgroup_usage_unregister_event(struct mem_cgroup
*memcg
,
3431 struct eventfd_ctx
*eventfd
, enum res_type type
)
3433 struct mem_cgroup_thresholds
*thresholds
;
3434 struct mem_cgroup_threshold_ary
*new;
3435 unsigned long usage
;
3438 mutex_lock(&memcg
->thresholds_lock
);
3441 thresholds
= &memcg
->thresholds
;
3442 usage
= mem_cgroup_usage(memcg
, false);
3443 } else if (type
== _MEMSWAP
) {
3444 thresholds
= &memcg
->memsw_thresholds
;
3445 usage
= mem_cgroup_usage(memcg
, true);
3449 if (!thresholds
->primary
)
3452 /* Check if a threshold crossed before removing */
3453 __mem_cgroup_threshold(memcg
, type
== _MEMSWAP
);
3455 /* Calculate new number of threshold */
3457 for (i
= 0; i
< thresholds
->primary
->size
; i
++) {
3458 if (thresholds
->primary
->entries
[i
].eventfd
!= eventfd
)
3462 new = thresholds
->spare
;
3464 /* Set thresholds array to NULL if we don't have thresholds */
3473 /* Copy thresholds and find current threshold */
3474 new->current_threshold
= -1;
3475 for (i
= 0, j
= 0; i
< thresholds
->primary
->size
; i
++) {
3476 if (thresholds
->primary
->entries
[i
].eventfd
== eventfd
)
3479 new->entries
[j
] = thresholds
->primary
->entries
[i
];
3480 if (new->entries
[j
].threshold
<= usage
) {
3482 * new->current_threshold will not be used
3483 * until rcu_assign_pointer(), so it's safe to increment
3486 ++new->current_threshold
;
3492 /* Swap primary and spare array */
3493 thresholds
->spare
= thresholds
->primary
;
3495 rcu_assign_pointer(thresholds
->primary
, new);
3497 /* To be sure that nobody uses thresholds */
3500 /* If all events are unregistered, free the spare array */
3502 kfree(thresholds
->spare
);
3503 thresholds
->spare
= NULL
;
3506 mutex_unlock(&memcg
->thresholds_lock
);
3509 static void mem_cgroup_usage_unregister_event(struct mem_cgroup
*memcg
,
3510 struct eventfd_ctx
*eventfd
)
3512 return __mem_cgroup_usage_unregister_event(memcg
, eventfd
, _MEM
);
3515 static void memsw_cgroup_usage_unregister_event(struct mem_cgroup
*memcg
,
3516 struct eventfd_ctx
*eventfd
)
3518 return __mem_cgroup_usage_unregister_event(memcg
, eventfd
, _MEMSWAP
);
3521 static int mem_cgroup_oom_register_event(struct mem_cgroup
*memcg
,
3522 struct eventfd_ctx
*eventfd
, const char *args
)
3524 struct mem_cgroup_eventfd_list
*event
;
3526 event
= kmalloc(sizeof(*event
), GFP_KERNEL
);
3530 spin_lock(&memcg_oom_lock
);
3532 event
->eventfd
= eventfd
;
3533 list_add(&event
->list
, &memcg
->oom_notify
);
3535 /* already in OOM ? */
3536 if (memcg
->under_oom
)
3537 eventfd_signal(eventfd
, 1);
3538 spin_unlock(&memcg_oom_lock
);
3543 static void mem_cgroup_oom_unregister_event(struct mem_cgroup
*memcg
,
3544 struct eventfd_ctx
*eventfd
)
3546 struct mem_cgroup_eventfd_list
*ev
, *tmp
;
3548 spin_lock(&memcg_oom_lock
);
3550 list_for_each_entry_safe(ev
, tmp
, &memcg
->oom_notify
, list
) {
3551 if (ev
->eventfd
== eventfd
) {
3552 list_del(&ev
->list
);
3557 spin_unlock(&memcg_oom_lock
);
3560 static int mem_cgroup_oom_control_read(struct seq_file
*sf
, void *v
)
3562 struct mem_cgroup
*memcg
= mem_cgroup_from_css(seq_css(sf
));
3564 seq_printf(sf
, "oom_kill_disable %d\n", memcg
->oom_kill_disable
);
3565 seq_printf(sf
, "under_oom %d\n", (bool)memcg
->under_oom
);
3569 static int mem_cgroup_oom_control_write(struct cgroup_subsys_state
*css
,
3570 struct cftype
*cft
, u64 val
)
3572 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
3574 /* cannot set to root cgroup and only 0 and 1 are allowed */
3575 if (!css
->parent
|| !((val
== 0) || (val
== 1)))
3578 memcg
->oom_kill_disable
= val
;
3580 memcg_oom_recover(memcg
);
3585 #ifdef CONFIG_MEMCG_KMEM
3586 static int memcg_init_kmem(struct mem_cgroup
*memcg
, struct cgroup_subsys
*ss
)
3590 ret
= memcg_propagate_kmem(memcg
);
3594 return tcp_init_cgroup(memcg
, ss
);
3597 static void memcg_deactivate_kmem(struct mem_cgroup
*memcg
)
3599 struct cgroup_subsys_state
*css
;
3600 struct mem_cgroup
*parent
, *child
;
3603 if (!memcg
->kmem_acct_active
)
3607 * Clear the 'active' flag before clearing memcg_caches arrays entries.
3608 * Since we take the slab_mutex in memcg_deactivate_kmem_caches(), it
3609 * guarantees no cache will be created for this cgroup after we are
3610 * done (see memcg_create_kmem_cache()).
3612 memcg
->kmem_acct_active
= false;
3614 memcg_deactivate_kmem_caches(memcg
);
3616 kmemcg_id
= memcg
->kmemcg_id
;
3617 BUG_ON(kmemcg_id
< 0);
3619 parent
= parent_mem_cgroup(memcg
);
3621 parent
= root_mem_cgroup
;
3624 * Change kmemcg_id of this cgroup and all its descendants to the
3625 * parent's id, and then move all entries from this cgroup's list_lrus
3626 * to ones of the parent. After we have finished, all list_lrus
3627 * corresponding to this cgroup are guaranteed to remain empty. The
3628 * ordering is imposed by list_lru_node->lock taken by
3629 * memcg_drain_all_list_lrus().
3631 css_for_each_descendant_pre(css
, &memcg
->css
) {
3632 child
= mem_cgroup_from_css(css
);
3633 BUG_ON(child
->kmemcg_id
!= kmemcg_id
);
3634 child
->kmemcg_id
= parent
->kmemcg_id
;
3635 if (!memcg
->use_hierarchy
)
3638 memcg_drain_all_list_lrus(kmemcg_id
, parent
->kmemcg_id
);
3640 memcg_free_cache_id(kmemcg_id
);
3643 static void memcg_destroy_kmem(struct mem_cgroup
*memcg
)
3645 if (memcg
->kmem_acct_activated
) {
3646 memcg_destroy_kmem_caches(memcg
);
3647 static_branch_dec(&memcg_kmem_enabled_key
);
3648 WARN_ON(page_counter_read(&memcg
->kmem
));
3650 tcp_destroy_cgroup(memcg
);
3653 static int memcg_init_kmem(struct mem_cgroup
*memcg
, struct cgroup_subsys
*ss
)
3658 static void memcg_deactivate_kmem(struct mem_cgroup
*memcg
)
3662 static void memcg_destroy_kmem(struct mem_cgroup
*memcg
)
3667 #ifdef CONFIG_CGROUP_WRITEBACK
3669 struct list_head
*mem_cgroup_cgwb_list(struct mem_cgroup
*memcg
)
3671 return &memcg
->cgwb_list
;
3674 static int memcg_wb_domain_init(struct mem_cgroup
*memcg
, gfp_t gfp
)
3676 return wb_domain_init(&memcg
->cgwb_domain
, gfp
);
3679 static void memcg_wb_domain_exit(struct mem_cgroup
*memcg
)
3681 wb_domain_exit(&memcg
->cgwb_domain
);
3684 static void memcg_wb_domain_size_changed(struct mem_cgroup
*memcg
)
3686 wb_domain_size_changed(&memcg
->cgwb_domain
);
3689 struct wb_domain
*mem_cgroup_wb_domain(struct bdi_writeback
*wb
)
3691 struct mem_cgroup
*memcg
= mem_cgroup_from_css(wb
->memcg_css
);
3693 if (!memcg
->css
.parent
)
3696 return &memcg
->cgwb_domain
;
3700 * mem_cgroup_wb_stats - retrieve writeback related stats from its memcg
3701 * @wb: bdi_writeback in question
3702 * @pfilepages: out parameter for number of file pages
3703 * @pheadroom: out parameter for number of allocatable pages according to memcg
3704 * @pdirty: out parameter for number of dirty pages
3705 * @pwriteback: out parameter for number of pages under writeback
3707 * Determine the numbers of file, headroom, dirty, and writeback pages in
3708 * @wb's memcg. File, dirty and writeback are self-explanatory. Headroom
3709 * is a bit more involved.
3711 * A memcg's headroom is "min(max, high) - used". In the hierarchy, the
3712 * headroom is calculated as the lowest headroom of itself and the
3713 * ancestors. Note that this doesn't consider the actual amount of
3714 * available memory in the system. The caller should further cap
3715 * *@pheadroom accordingly.
3717 void mem_cgroup_wb_stats(struct bdi_writeback
*wb
, unsigned long *pfilepages
,
3718 unsigned long *pheadroom
, unsigned long *pdirty
,
3719 unsigned long *pwriteback
)
3721 struct mem_cgroup
*memcg
= mem_cgroup_from_css(wb
->memcg_css
);
3722 struct mem_cgroup
*parent
;
3724 *pdirty
= mem_cgroup_read_stat(memcg
, MEM_CGROUP_STAT_DIRTY
);
3726 /* this should eventually include NR_UNSTABLE_NFS */
3727 *pwriteback
= mem_cgroup_read_stat(memcg
, MEM_CGROUP_STAT_WRITEBACK
);
3728 *pfilepages
= mem_cgroup_nr_lru_pages(memcg
, (1 << LRU_INACTIVE_FILE
) |
3729 (1 << LRU_ACTIVE_FILE
));
3730 *pheadroom
= PAGE_COUNTER_MAX
;
3732 while ((parent
= parent_mem_cgroup(memcg
))) {
3733 unsigned long ceiling
= min(memcg
->memory
.limit
, memcg
->high
);
3734 unsigned long used
= page_counter_read(&memcg
->memory
);
3736 *pheadroom
= min(*pheadroom
, ceiling
- min(ceiling
, used
));
3741 #else /* CONFIG_CGROUP_WRITEBACK */
3743 static int memcg_wb_domain_init(struct mem_cgroup
*memcg
, gfp_t gfp
)
3748 static void memcg_wb_domain_exit(struct mem_cgroup
*memcg
)
3752 static void memcg_wb_domain_size_changed(struct mem_cgroup
*memcg
)
3756 #endif /* CONFIG_CGROUP_WRITEBACK */
3759 * DO NOT USE IN NEW FILES.
3761 * "cgroup.event_control" implementation.
3763 * This is way over-engineered. It tries to support fully configurable
3764 * events for each user. Such level of flexibility is completely
3765 * unnecessary especially in the light of the planned unified hierarchy.
3767 * Please deprecate this and replace with something simpler if at all
3772 * Unregister event and free resources.
3774 * Gets called from workqueue.
3776 static void memcg_event_remove(struct work_struct
*work
)
3778 struct mem_cgroup_event
*event
=
3779 container_of(work
, struct mem_cgroup_event
, remove
);
3780 struct mem_cgroup
*memcg
= event
->memcg
;
3782 remove_wait_queue(event
->wqh
, &event
->wait
);
3784 event
->unregister_event(memcg
, event
->eventfd
);
3786 /* Notify userspace the event is going away. */
3787 eventfd_signal(event
->eventfd
, 1);
3789 eventfd_ctx_put(event
->eventfd
);
3791 css_put(&memcg
->css
);
3795 * Gets called on POLLHUP on eventfd when user closes it.
3797 * Called with wqh->lock held and interrupts disabled.
3799 static int memcg_event_wake(wait_queue_t
*wait
, unsigned mode
,
3800 int sync
, void *key
)
3802 struct mem_cgroup_event
*event
=
3803 container_of(wait
, struct mem_cgroup_event
, wait
);
3804 struct mem_cgroup
*memcg
= event
->memcg
;
3805 unsigned long flags
= (unsigned long)key
;
3807 if (flags
& POLLHUP
) {
3809 * If the event has been detached at cgroup removal, we
3810 * can simply return knowing the other side will cleanup
3813 * We can't race against event freeing since the other
3814 * side will require wqh->lock via remove_wait_queue(),
3817 spin_lock(&memcg
->event_list_lock
);
3818 if (!list_empty(&event
->list
)) {
3819 list_del_init(&event
->list
);
3821 * We are in atomic context, but cgroup_event_remove()
3822 * may sleep, so we have to call it in workqueue.
3824 schedule_work(&event
->remove
);
3826 spin_unlock(&memcg
->event_list_lock
);
3832 static void memcg_event_ptable_queue_proc(struct file
*file
,
3833 wait_queue_head_t
*wqh
, poll_table
*pt
)
3835 struct mem_cgroup_event
*event
=
3836 container_of(pt
, struct mem_cgroup_event
, pt
);
3839 add_wait_queue(wqh
, &event
->wait
);
3843 * DO NOT USE IN NEW FILES.
3845 * Parse input and register new cgroup event handler.
3847 * Input must be in format '<event_fd> <control_fd> <args>'.
3848 * Interpretation of args is defined by control file implementation.
3850 static ssize_t
memcg_write_event_control(struct kernfs_open_file
*of
,
3851 char *buf
, size_t nbytes
, loff_t off
)
3853 struct cgroup_subsys_state
*css
= of_css(of
);
3854 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
3855 struct mem_cgroup_event
*event
;
3856 struct cgroup_subsys_state
*cfile_css
;
3857 unsigned int efd
, cfd
;
3864 buf
= strstrip(buf
);
3866 efd
= simple_strtoul(buf
, &endp
, 10);
3871 cfd
= simple_strtoul(buf
, &endp
, 10);
3872 if ((*endp
!= ' ') && (*endp
!= '\0'))
3876 event
= kzalloc(sizeof(*event
), GFP_KERNEL
);
3880 event
->memcg
= memcg
;
3881 INIT_LIST_HEAD(&event
->list
);
3882 init_poll_funcptr(&event
->pt
, memcg_event_ptable_queue_proc
);
3883 init_waitqueue_func_entry(&event
->wait
, memcg_event_wake
);
3884 INIT_WORK(&event
->remove
, memcg_event_remove
);
3892 event
->eventfd
= eventfd_ctx_fileget(efile
.file
);
3893 if (IS_ERR(event
->eventfd
)) {
3894 ret
= PTR_ERR(event
->eventfd
);
3901 goto out_put_eventfd
;
3904 /* the process need read permission on control file */
3905 /* AV: shouldn't we check that it's been opened for read instead? */
3906 ret
= inode_permission(file_inode(cfile
.file
), MAY_READ
);
3911 * Determine the event callbacks and set them in @event. This used
3912 * to be done via struct cftype but cgroup core no longer knows
3913 * about these events. The following is crude but the whole thing
3914 * is for compatibility anyway.
3916 * DO NOT ADD NEW FILES.
3918 name
= cfile
.file
->f_path
.dentry
->d_name
.name
;
3920 if (!strcmp(name
, "memory.usage_in_bytes")) {
3921 event
->register_event
= mem_cgroup_usage_register_event
;
3922 event
->unregister_event
= mem_cgroup_usage_unregister_event
;
3923 } else if (!strcmp(name
, "memory.oom_control")) {
3924 event
->register_event
= mem_cgroup_oom_register_event
;
3925 event
->unregister_event
= mem_cgroup_oom_unregister_event
;
3926 } else if (!strcmp(name
, "memory.pressure_level")) {
3927 event
->register_event
= vmpressure_register_event
;
3928 event
->unregister_event
= vmpressure_unregister_event
;
3929 } else if (!strcmp(name
, "memory.memsw.usage_in_bytes")) {
3930 event
->register_event
= memsw_cgroup_usage_register_event
;
3931 event
->unregister_event
= memsw_cgroup_usage_unregister_event
;
3938 * Verify @cfile should belong to @css. Also, remaining events are
3939 * automatically removed on cgroup destruction but the removal is
3940 * asynchronous, so take an extra ref on @css.
3942 cfile_css
= css_tryget_online_from_dir(cfile
.file
->f_path
.dentry
->d_parent
,
3943 &memory_cgrp_subsys
);
3945 if (IS_ERR(cfile_css
))
3947 if (cfile_css
!= css
) {
3952 ret
= event
->register_event(memcg
, event
->eventfd
, buf
);
3956 efile
.file
->f_op
->poll(efile
.file
, &event
->pt
);
3958 spin_lock(&memcg
->event_list_lock
);
3959 list_add(&event
->list
, &memcg
->event_list
);
3960 spin_unlock(&memcg
->event_list_lock
);
3972 eventfd_ctx_put(event
->eventfd
);
3981 static struct cftype mem_cgroup_legacy_files
[] = {
3983 .name
= "usage_in_bytes",
3984 .private = MEMFILE_PRIVATE(_MEM
, RES_USAGE
),
3985 .read_u64
= mem_cgroup_read_u64
,
3988 .name
= "max_usage_in_bytes",
3989 .private = MEMFILE_PRIVATE(_MEM
, RES_MAX_USAGE
),
3990 .write
= mem_cgroup_reset
,
3991 .read_u64
= mem_cgroup_read_u64
,
3994 .name
= "limit_in_bytes",
3995 .private = MEMFILE_PRIVATE(_MEM
, RES_LIMIT
),
3996 .write
= mem_cgroup_write
,
3997 .read_u64
= mem_cgroup_read_u64
,
4000 .name
= "soft_limit_in_bytes",
4001 .private = MEMFILE_PRIVATE(_MEM
, RES_SOFT_LIMIT
),
4002 .write
= mem_cgroup_write
,
4003 .read_u64
= mem_cgroup_read_u64
,
4007 .private = MEMFILE_PRIVATE(_MEM
, RES_FAILCNT
),
4008 .write
= mem_cgroup_reset
,
4009 .read_u64
= mem_cgroup_read_u64
,
4013 .seq_show
= memcg_stat_show
,
4016 .name
= "force_empty",
4017 .write
= mem_cgroup_force_empty_write
,
4020 .name
= "use_hierarchy",
4021 .write_u64
= mem_cgroup_hierarchy_write
,
4022 .read_u64
= mem_cgroup_hierarchy_read
,
4025 .name
= "cgroup.event_control", /* XXX: for compat */
4026 .write
= memcg_write_event_control
,
4027 .flags
= CFTYPE_NO_PREFIX
| CFTYPE_WORLD_WRITABLE
,
4030 .name
= "swappiness",
4031 .read_u64
= mem_cgroup_swappiness_read
,
4032 .write_u64
= mem_cgroup_swappiness_write
,
4035 .name
= "move_charge_at_immigrate",
4036 .read_u64
= mem_cgroup_move_charge_read
,
4037 .write_u64
= mem_cgroup_move_charge_write
,
4040 .name
= "oom_control",
4041 .seq_show
= mem_cgroup_oom_control_read
,
4042 .write_u64
= mem_cgroup_oom_control_write
,
4043 .private = MEMFILE_PRIVATE(_OOM_TYPE
, OOM_CONTROL
),
4046 .name
= "pressure_level",
4050 .name
= "numa_stat",
4051 .seq_show
= memcg_numa_stat_show
,
4054 #ifdef CONFIG_MEMCG_KMEM
4056 .name
= "kmem.limit_in_bytes",
4057 .private = MEMFILE_PRIVATE(_KMEM
, RES_LIMIT
),
4058 .write
= mem_cgroup_write
,
4059 .read_u64
= mem_cgroup_read_u64
,
4062 .name
= "kmem.usage_in_bytes",
4063 .private = MEMFILE_PRIVATE(_KMEM
, RES_USAGE
),
4064 .read_u64
= mem_cgroup_read_u64
,
4067 .name
= "kmem.failcnt",
4068 .private = MEMFILE_PRIVATE(_KMEM
, RES_FAILCNT
),
4069 .write
= mem_cgroup_reset
,
4070 .read_u64
= mem_cgroup_read_u64
,
4073 .name
= "kmem.max_usage_in_bytes",
4074 .private = MEMFILE_PRIVATE(_KMEM
, RES_MAX_USAGE
),
4075 .write
= mem_cgroup_reset
,
4076 .read_u64
= mem_cgroup_read_u64
,
4078 #ifdef CONFIG_SLABINFO
4080 .name
= "kmem.slabinfo",
4081 .seq_start
= slab_start
,
4082 .seq_next
= slab_next
,
4083 .seq_stop
= slab_stop
,
4084 .seq_show
= memcg_slab_show
,
4088 { }, /* terminate */
4091 static int alloc_mem_cgroup_per_zone_info(struct mem_cgroup
*memcg
, int node
)
4093 struct mem_cgroup_per_node
*pn
;
4094 struct mem_cgroup_per_zone
*mz
;
4095 int zone
, tmp
= node
;
4097 * This routine is called against possible nodes.
4098 * But it's BUG to call kmalloc() against offline node.
4100 * TODO: this routine can waste much memory for nodes which will
4101 * never be onlined. It's better to use memory hotplug callback
4104 if (!node_state(node
, N_NORMAL_MEMORY
))
4106 pn
= kzalloc_node(sizeof(*pn
), GFP_KERNEL
, tmp
);
4110 for (zone
= 0; zone
< MAX_NR_ZONES
; zone
++) {
4111 mz
= &pn
->zoneinfo
[zone
];
4112 lruvec_init(&mz
->lruvec
);
4113 mz
->usage_in_excess
= 0;
4114 mz
->on_tree
= false;
4117 memcg
->nodeinfo
[node
] = pn
;
4121 static void free_mem_cgroup_per_zone_info(struct mem_cgroup
*memcg
, int node
)
4123 kfree(memcg
->nodeinfo
[node
]);
4126 static struct mem_cgroup
*mem_cgroup_alloc(void)
4128 struct mem_cgroup
*memcg
;
4131 size
= sizeof(struct mem_cgroup
);
4132 size
+= nr_node_ids
* sizeof(struct mem_cgroup_per_node
*);
4134 memcg
= kzalloc(size
, GFP_KERNEL
);
4138 memcg
->stat
= alloc_percpu(struct mem_cgroup_stat_cpu
);
4142 if (memcg_wb_domain_init(memcg
, GFP_KERNEL
))
4148 free_percpu(memcg
->stat
);
4155 * At destroying mem_cgroup, references from swap_cgroup can remain.
4156 * (scanning all at force_empty is too costly...)
4158 * Instead of clearing all references at force_empty, we remember
4159 * the number of reference from swap_cgroup and free mem_cgroup when
4160 * it goes down to 0.
4162 * Removal of cgroup itself succeeds regardless of refs from swap.
4165 static void __mem_cgroup_free(struct mem_cgroup
*memcg
)
4169 cancel_work_sync(&memcg
->high_work
);
4171 mem_cgroup_remove_from_trees(memcg
);
4174 free_mem_cgroup_per_zone_info(memcg
, node
);
4176 free_percpu(memcg
->stat
);
4177 memcg_wb_domain_exit(memcg
);
4181 static struct cgroup_subsys_state
* __ref
4182 mem_cgroup_css_alloc(struct cgroup_subsys_state
*parent_css
)
4184 struct mem_cgroup
*memcg
;
4185 long error
= -ENOMEM
;
4188 memcg
= mem_cgroup_alloc();
4190 return ERR_PTR(error
);
4193 if (alloc_mem_cgroup_per_zone_info(memcg
, node
))
4197 if (parent_css
== NULL
) {
4198 root_mem_cgroup
= memcg
;
4199 page_counter_init(&memcg
->memory
, NULL
);
4200 memcg
->high
= PAGE_COUNTER_MAX
;
4201 memcg
->soft_limit
= PAGE_COUNTER_MAX
;
4202 page_counter_init(&memcg
->memsw
, NULL
);
4203 page_counter_init(&memcg
->kmem
, NULL
);
4206 INIT_WORK(&memcg
->high_work
, high_work_func
);
4207 memcg
->last_scanned_node
= MAX_NUMNODES
;
4208 INIT_LIST_HEAD(&memcg
->oom_notify
);
4209 memcg
->move_charge_at_immigrate
= 0;
4210 mutex_init(&memcg
->thresholds_lock
);
4211 spin_lock_init(&memcg
->move_lock
);
4212 vmpressure_init(&memcg
->vmpressure
);
4213 INIT_LIST_HEAD(&memcg
->event_list
);
4214 spin_lock_init(&memcg
->event_list_lock
);
4215 #ifdef CONFIG_MEMCG_KMEM
4216 memcg
->kmemcg_id
= -1;
4218 #ifdef CONFIG_CGROUP_WRITEBACK
4219 INIT_LIST_HEAD(&memcg
->cgwb_list
);
4222 memcg
->socket_pressure
= jiffies
;
4227 __mem_cgroup_free(memcg
);
4228 return ERR_PTR(error
);
4232 mem_cgroup_css_online(struct cgroup_subsys_state
*css
)
4234 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
4235 struct mem_cgroup
*parent
= mem_cgroup_from_css(css
->parent
);
4238 if (css
->id
> MEM_CGROUP_ID_MAX
)
4244 mutex_lock(&memcg_create_mutex
);
4246 memcg
->use_hierarchy
= parent
->use_hierarchy
;
4247 memcg
->oom_kill_disable
= parent
->oom_kill_disable
;
4248 memcg
->swappiness
= mem_cgroup_swappiness(parent
);
4250 if (parent
->use_hierarchy
) {
4251 page_counter_init(&memcg
->memory
, &parent
->memory
);
4252 memcg
->high
= PAGE_COUNTER_MAX
;
4253 memcg
->soft_limit
= PAGE_COUNTER_MAX
;
4254 page_counter_init(&memcg
->memsw
, &parent
->memsw
);
4255 page_counter_init(&memcg
->kmem
, &parent
->kmem
);
4258 * No need to take a reference to the parent because cgroup
4259 * core guarantees its existence.
4262 page_counter_init(&memcg
->memory
, NULL
);
4263 memcg
->high
= PAGE_COUNTER_MAX
;
4264 memcg
->soft_limit
= PAGE_COUNTER_MAX
;
4265 page_counter_init(&memcg
->memsw
, NULL
);
4266 page_counter_init(&memcg
->kmem
, NULL
);
4268 * Deeper hierachy with use_hierarchy == false doesn't make
4269 * much sense so let cgroup subsystem know about this
4270 * unfortunate state in our controller.
4272 if (parent
!= root_mem_cgroup
)
4273 memory_cgrp_subsys
.broken_hierarchy
= true;
4275 mutex_unlock(&memcg_create_mutex
);
4277 ret
= memcg_init_kmem(memcg
, &memory_cgrp_subsys
);
4282 if (cgroup_subsys_on_dfl(memory_cgrp_subsys
) && !cgroup_memory_nosocket
)
4283 static_branch_inc(&memcg_sockets_enabled_key
);
4287 * Make sure the memcg is initialized: mem_cgroup_iter()
4288 * orders reading memcg->initialized against its callers
4289 * reading the memcg members.
4291 smp_store_release(&memcg
->initialized
, 1);
4296 static void mem_cgroup_css_offline(struct cgroup_subsys_state
*css
)
4298 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
4299 struct mem_cgroup_event
*event
, *tmp
;
4302 * Unregister events and notify userspace.
4303 * Notify userspace about cgroup removing only after rmdir of cgroup
4304 * directory to avoid race between userspace and kernelspace.
4306 spin_lock(&memcg
->event_list_lock
);
4307 list_for_each_entry_safe(event
, tmp
, &memcg
->event_list
, list
) {
4308 list_del_init(&event
->list
);
4309 schedule_work(&event
->remove
);
4311 spin_unlock(&memcg
->event_list_lock
);
4313 vmpressure_cleanup(&memcg
->vmpressure
);
4315 memcg_deactivate_kmem(memcg
);
4317 wb_memcg_offline(memcg
);
4320 static void mem_cgroup_css_released(struct cgroup_subsys_state
*css
)
4322 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
4324 invalidate_reclaim_iterators(memcg
);
4327 static void mem_cgroup_css_free(struct cgroup_subsys_state
*css
)
4329 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
4331 memcg_destroy_kmem(memcg
);
4333 if (cgroup_subsys_on_dfl(memory_cgrp_subsys
) && !cgroup_memory_nosocket
)
4334 static_branch_dec(&memcg_sockets_enabled_key
);
4336 __mem_cgroup_free(memcg
);
4340 * mem_cgroup_css_reset - reset the states of a mem_cgroup
4341 * @css: the target css
4343 * Reset the states of the mem_cgroup associated with @css. This is
4344 * invoked when the userland requests disabling on the default hierarchy
4345 * but the memcg is pinned through dependency. The memcg should stop
4346 * applying policies and should revert to the vanilla state as it may be
4347 * made visible again.
4349 * The current implementation only resets the essential configurations.
4350 * This needs to be expanded to cover all the visible parts.
4352 static void mem_cgroup_css_reset(struct cgroup_subsys_state
*css
)
4354 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
4356 mem_cgroup_resize_limit(memcg
, PAGE_COUNTER_MAX
);
4357 mem_cgroup_resize_memsw_limit(memcg
, PAGE_COUNTER_MAX
);
4358 memcg_update_kmem_limit(memcg
, PAGE_COUNTER_MAX
);
4360 memcg
->high
= PAGE_COUNTER_MAX
;
4361 memcg
->soft_limit
= PAGE_COUNTER_MAX
;
4362 memcg_wb_domain_size_changed(memcg
);
4366 /* Handlers for move charge at task migration. */
4367 static int mem_cgroup_do_precharge(unsigned long count
)
4371 /* Try a single bulk charge without reclaim first, kswapd may wake */
4372 ret
= try_charge(mc
.to
, GFP_KERNEL
& ~__GFP_DIRECT_RECLAIM
, count
);
4374 mc
.precharge
+= count
;
4378 /* Try charges one by one with reclaim */
4380 ret
= try_charge(mc
.to
, GFP_KERNEL
& ~__GFP_NORETRY
, 1);
4390 * get_mctgt_type - get target type of moving charge
4391 * @vma: the vma the pte to be checked belongs
4392 * @addr: the address corresponding to the pte to be checked
4393 * @ptent: the pte to be checked
4394 * @target: the pointer the target page or swap ent will be stored(can be NULL)
4397 * 0(MC_TARGET_NONE): if the pte is not a target for move charge.
4398 * 1(MC_TARGET_PAGE): if the page corresponding to this pte is a target for
4399 * move charge. if @target is not NULL, the page is stored in target->page
4400 * with extra refcnt got(Callers should handle it).
4401 * 2(MC_TARGET_SWAP): if the swap entry corresponding to this pte is a
4402 * target for charge migration. if @target is not NULL, the entry is stored
4405 * Called with pte lock held.
4412 enum mc_target_type
{
4418 static struct page
*mc_handle_present_pte(struct vm_area_struct
*vma
,
4419 unsigned long addr
, pte_t ptent
)
4421 struct page
*page
= vm_normal_page(vma
, addr
, ptent
);
4423 if (!page
|| !page_mapped(page
))
4425 if (PageAnon(page
)) {
4426 if (!(mc
.flags
& MOVE_ANON
))
4429 if (!(mc
.flags
& MOVE_FILE
))
4432 if (!get_page_unless_zero(page
))
4439 static struct page
*mc_handle_swap_pte(struct vm_area_struct
*vma
,
4440 unsigned long addr
, pte_t ptent
, swp_entry_t
*entry
)
4442 struct page
*page
= NULL
;
4443 swp_entry_t ent
= pte_to_swp_entry(ptent
);
4445 if (!(mc
.flags
& MOVE_ANON
) || non_swap_entry(ent
))
4448 * Because lookup_swap_cache() updates some statistics counter,
4449 * we call find_get_page() with swapper_space directly.
4451 page
= find_get_page(swap_address_space(ent
), ent
.val
);
4452 if (do_memsw_account())
4453 entry
->val
= ent
.val
;
4458 static struct page
*mc_handle_swap_pte(struct vm_area_struct
*vma
,
4459 unsigned long addr
, pte_t ptent
, swp_entry_t
*entry
)
4465 static struct page
*mc_handle_file_pte(struct vm_area_struct
*vma
,
4466 unsigned long addr
, pte_t ptent
, swp_entry_t
*entry
)
4468 struct page
*page
= NULL
;
4469 struct address_space
*mapping
;
4472 if (!vma
->vm_file
) /* anonymous vma */
4474 if (!(mc
.flags
& MOVE_FILE
))
4477 mapping
= vma
->vm_file
->f_mapping
;
4478 pgoff
= linear_page_index(vma
, addr
);
4480 /* page is moved even if it's not RSS of this task(page-faulted). */
4482 /* shmem/tmpfs may report page out on swap: account for that too. */
4483 if (shmem_mapping(mapping
)) {
4484 page
= find_get_entry(mapping
, pgoff
);
4485 if (radix_tree_exceptional_entry(page
)) {
4486 swp_entry_t swp
= radix_to_swp_entry(page
);
4487 if (do_memsw_account())
4489 page
= find_get_page(swap_address_space(swp
), swp
.val
);
4492 page
= find_get_page(mapping
, pgoff
);
4494 page
= find_get_page(mapping
, pgoff
);
4500 * mem_cgroup_move_account - move account of the page
4502 * @nr_pages: number of regular pages (>1 for huge pages)
4503 * @from: mem_cgroup which the page is moved from.
4504 * @to: mem_cgroup which the page is moved to. @from != @to.
4506 * The caller must make sure the page is not on LRU (isolate_page() is useful.)
4508 * This function doesn't do "charge" to new cgroup and doesn't do "uncharge"
4511 static int mem_cgroup_move_account(struct page
*page
,
4513 struct mem_cgroup
*from
,
4514 struct mem_cgroup
*to
)
4516 unsigned long flags
;
4517 unsigned int nr_pages
= compound
? hpage_nr_pages(page
) : 1;
4521 VM_BUG_ON(from
== to
);
4522 VM_BUG_ON_PAGE(PageLRU(page
), page
);
4523 VM_BUG_ON(compound
&& !PageTransHuge(page
));
4526 * Prevent mem_cgroup_replace_page() from looking at
4527 * page->mem_cgroup of its source page while we change it.
4530 if (!trylock_page(page
))
4534 if (page
->mem_cgroup
!= from
)
4537 anon
= PageAnon(page
);
4539 spin_lock_irqsave(&from
->move_lock
, flags
);
4541 if (!anon
&& page_mapped(page
)) {
4542 __this_cpu_sub(from
->stat
->count
[MEM_CGROUP_STAT_FILE_MAPPED
],
4544 __this_cpu_add(to
->stat
->count
[MEM_CGROUP_STAT_FILE_MAPPED
],
4549 * move_lock grabbed above and caller set from->moving_account, so
4550 * mem_cgroup_update_page_stat() will serialize updates to PageDirty.
4551 * So mapping should be stable for dirty pages.
4553 if (!anon
&& PageDirty(page
)) {
4554 struct address_space
*mapping
= page_mapping(page
);
4556 if (mapping_cap_account_dirty(mapping
)) {
4557 __this_cpu_sub(from
->stat
->count
[MEM_CGROUP_STAT_DIRTY
],
4559 __this_cpu_add(to
->stat
->count
[MEM_CGROUP_STAT_DIRTY
],
4564 if (PageWriteback(page
)) {
4565 __this_cpu_sub(from
->stat
->count
[MEM_CGROUP_STAT_WRITEBACK
],
4567 __this_cpu_add(to
->stat
->count
[MEM_CGROUP_STAT_WRITEBACK
],
4572 * It is safe to change page->mem_cgroup here because the page
4573 * is referenced, charged, and isolated - we can't race with
4574 * uncharging, charging, migration, or LRU putback.
4577 /* caller should have done css_get */
4578 page
->mem_cgroup
= to
;
4579 spin_unlock_irqrestore(&from
->move_lock
, flags
);
4583 local_irq_disable();
4584 mem_cgroup_charge_statistics(to
, page
, compound
, nr_pages
);
4585 memcg_check_events(to
, page
);
4586 mem_cgroup_charge_statistics(from
, page
, compound
, -nr_pages
);
4587 memcg_check_events(from
, page
);
4595 static enum mc_target_type
get_mctgt_type(struct vm_area_struct
*vma
,
4596 unsigned long addr
, pte_t ptent
, union mc_target
*target
)
4598 struct page
*page
= NULL
;
4599 enum mc_target_type ret
= MC_TARGET_NONE
;
4600 swp_entry_t ent
= { .val
= 0 };
4602 if (pte_present(ptent
))
4603 page
= mc_handle_present_pte(vma
, addr
, ptent
);
4604 else if (is_swap_pte(ptent
))
4605 page
= mc_handle_swap_pte(vma
, addr
, ptent
, &ent
);
4606 else if (pte_none(ptent
))
4607 page
= mc_handle_file_pte(vma
, addr
, ptent
, &ent
);
4609 if (!page
&& !ent
.val
)
4613 * Do only loose check w/o serialization.
4614 * mem_cgroup_move_account() checks the page is valid or
4615 * not under LRU exclusion.
4617 if (page
->mem_cgroup
== mc
.from
) {
4618 ret
= MC_TARGET_PAGE
;
4620 target
->page
= page
;
4622 if (!ret
|| !target
)
4625 /* There is a swap entry and a page doesn't exist or isn't charged */
4626 if (ent
.val
&& !ret
&&
4627 mem_cgroup_id(mc
.from
) == lookup_swap_cgroup_id(ent
)) {
4628 ret
= MC_TARGET_SWAP
;
4635 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
4637 * We don't consider swapping or file mapped pages because THP does not
4638 * support them for now.
4639 * Caller should make sure that pmd_trans_huge(pmd) is true.
4641 static enum mc_target_type
get_mctgt_type_thp(struct vm_area_struct
*vma
,
4642 unsigned long addr
, pmd_t pmd
, union mc_target
*target
)
4644 struct page
*page
= NULL
;
4645 enum mc_target_type ret
= MC_TARGET_NONE
;
4647 page
= pmd_page(pmd
);
4648 VM_BUG_ON_PAGE(!page
|| !PageHead(page
), page
);
4649 if (!(mc
.flags
& MOVE_ANON
))
4651 if (page
->mem_cgroup
== mc
.from
) {
4652 ret
= MC_TARGET_PAGE
;
4655 target
->page
= page
;
4661 static inline enum mc_target_type
get_mctgt_type_thp(struct vm_area_struct
*vma
,
4662 unsigned long addr
, pmd_t pmd
, union mc_target
*target
)
4664 return MC_TARGET_NONE
;
4668 static int mem_cgroup_count_precharge_pte_range(pmd_t
*pmd
,
4669 unsigned long addr
, unsigned long end
,
4670 struct mm_walk
*walk
)
4672 struct vm_area_struct
*vma
= walk
->vma
;
4676 if (pmd_trans_huge_lock(pmd
, vma
, &ptl
)) {
4677 if (get_mctgt_type_thp(vma
, addr
, *pmd
, NULL
) == MC_TARGET_PAGE
)
4678 mc
.precharge
+= HPAGE_PMD_NR
;
4683 if (pmd_trans_unstable(pmd
))
4685 pte
= pte_offset_map_lock(vma
->vm_mm
, pmd
, addr
, &ptl
);
4686 for (; addr
!= end
; pte
++, addr
+= PAGE_SIZE
)
4687 if (get_mctgt_type(vma
, addr
, *pte
, NULL
))
4688 mc
.precharge
++; /* increment precharge temporarily */
4689 pte_unmap_unlock(pte
- 1, ptl
);
4695 static unsigned long mem_cgroup_count_precharge(struct mm_struct
*mm
)
4697 unsigned long precharge
;
4699 struct mm_walk mem_cgroup_count_precharge_walk
= {
4700 .pmd_entry
= mem_cgroup_count_precharge_pte_range
,
4703 down_read(&mm
->mmap_sem
);
4704 walk_page_range(0, ~0UL, &mem_cgroup_count_precharge_walk
);
4705 up_read(&mm
->mmap_sem
);
4707 precharge
= mc
.precharge
;
4713 static int mem_cgroup_precharge_mc(struct mm_struct
*mm
)
4715 unsigned long precharge
= mem_cgroup_count_precharge(mm
);
4717 VM_BUG_ON(mc
.moving_task
);
4718 mc
.moving_task
= current
;
4719 return mem_cgroup_do_precharge(precharge
);
4722 /* cancels all extra charges on mc.from and mc.to, and wakes up all waiters. */
4723 static void __mem_cgroup_clear_mc(void)
4725 struct mem_cgroup
*from
= mc
.from
;
4726 struct mem_cgroup
*to
= mc
.to
;
4728 /* we must uncharge all the leftover precharges from mc.to */
4730 cancel_charge(mc
.to
, mc
.precharge
);
4734 * we didn't uncharge from mc.from at mem_cgroup_move_account(), so
4735 * we must uncharge here.
4737 if (mc
.moved_charge
) {
4738 cancel_charge(mc
.from
, mc
.moved_charge
);
4739 mc
.moved_charge
= 0;
4741 /* we must fixup refcnts and charges */
4742 if (mc
.moved_swap
) {
4743 /* uncharge swap account from the old cgroup */
4744 if (!mem_cgroup_is_root(mc
.from
))
4745 page_counter_uncharge(&mc
.from
->memsw
, mc
.moved_swap
);
4748 * we charged both to->memory and to->memsw, so we
4749 * should uncharge to->memory.
4751 if (!mem_cgroup_is_root(mc
.to
))
4752 page_counter_uncharge(&mc
.to
->memory
, mc
.moved_swap
);
4754 css_put_many(&mc
.from
->css
, mc
.moved_swap
);
4756 /* we've already done css_get(mc.to) */
4759 memcg_oom_recover(from
);
4760 memcg_oom_recover(to
);
4761 wake_up_all(&mc
.waitq
);
4764 static void mem_cgroup_clear_mc(void)
4767 * we must clear moving_task before waking up waiters at the end of
4770 mc
.moving_task
= NULL
;
4771 __mem_cgroup_clear_mc();
4772 spin_lock(&mc
.lock
);
4775 spin_unlock(&mc
.lock
);
4778 static int mem_cgroup_can_attach(struct cgroup_taskset
*tset
)
4780 struct cgroup_subsys_state
*css
;
4781 struct mem_cgroup
*memcg
= NULL
; /* unneeded init to make gcc happy */
4782 struct mem_cgroup
*from
;
4783 struct task_struct
*leader
, *p
;
4784 struct mm_struct
*mm
;
4785 unsigned long move_flags
;
4788 /* charge immigration isn't supported on the default hierarchy */
4789 if (cgroup_subsys_on_dfl(memory_cgrp_subsys
))
4793 * Multi-process migrations only happen on the default hierarchy
4794 * where charge immigration is not used. Perform charge
4795 * immigration if @tset contains a leader and whine if there are
4799 cgroup_taskset_for_each_leader(leader
, css
, tset
) {
4802 memcg
= mem_cgroup_from_css(css
);
4808 * We are now commited to this value whatever it is. Changes in this
4809 * tunable will only affect upcoming migrations, not the current one.
4810 * So we need to save it, and keep it going.
4812 move_flags
= READ_ONCE(memcg
->move_charge_at_immigrate
);
4816 from
= mem_cgroup_from_task(p
);
4818 VM_BUG_ON(from
== memcg
);
4820 mm
= get_task_mm(p
);
4823 /* We move charges only when we move a owner of the mm */
4824 if (mm
->owner
== p
) {
4827 VM_BUG_ON(mc
.precharge
);
4828 VM_BUG_ON(mc
.moved_charge
);
4829 VM_BUG_ON(mc
.moved_swap
);
4831 spin_lock(&mc
.lock
);
4834 mc
.flags
= move_flags
;
4835 spin_unlock(&mc
.lock
);
4836 /* We set mc.moving_task later */
4838 ret
= mem_cgroup_precharge_mc(mm
);
4840 mem_cgroup_clear_mc();
4846 static void mem_cgroup_cancel_attach(struct cgroup_taskset
*tset
)
4849 mem_cgroup_clear_mc();
4852 static int mem_cgroup_move_charge_pte_range(pmd_t
*pmd
,
4853 unsigned long addr
, unsigned long end
,
4854 struct mm_walk
*walk
)
4857 struct vm_area_struct
*vma
= walk
->vma
;
4860 enum mc_target_type target_type
;
4861 union mc_target target
;
4864 if (pmd_trans_huge_lock(pmd
, vma
, &ptl
)) {
4865 if (mc
.precharge
< HPAGE_PMD_NR
) {
4869 target_type
= get_mctgt_type_thp(vma
, addr
, *pmd
, &target
);
4870 if (target_type
== MC_TARGET_PAGE
) {
4872 if (!isolate_lru_page(page
)) {
4873 if (!mem_cgroup_move_account(page
, true,
4875 mc
.precharge
-= HPAGE_PMD_NR
;
4876 mc
.moved_charge
+= HPAGE_PMD_NR
;
4878 putback_lru_page(page
);
4886 if (pmd_trans_unstable(pmd
))
4889 pte
= pte_offset_map_lock(vma
->vm_mm
, pmd
, addr
, &ptl
);
4890 for (; addr
!= end
; addr
+= PAGE_SIZE
) {
4891 pte_t ptent
= *(pte
++);
4897 switch (get_mctgt_type(vma
, addr
, ptent
, &target
)) {
4898 case MC_TARGET_PAGE
:
4901 * We can have a part of the split pmd here. Moving it
4902 * can be done but it would be too convoluted so simply
4903 * ignore such a partial THP and keep it in original
4904 * memcg. There should be somebody mapping the head.
4906 if (PageTransCompound(page
))
4908 if (isolate_lru_page(page
))
4910 if (!mem_cgroup_move_account(page
, false,
4913 /* we uncharge from mc.from later. */
4916 putback_lru_page(page
);
4917 put
: /* get_mctgt_type() gets the page */
4920 case MC_TARGET_SWAP
:
4922 if (!mem_cgroup_move_swap_account(ent
, mc
.from
, mc
.to
)) {
4924 /* we fixup refcnts and charges later. */
4932 pte_unmap_unlock(pte
- 1, ptl
);
4937 * We have consumed all precharges we got in can_attach().
4938 * We try charge one by one, but don't do any additional
4939 * charges to mc.to if we have failed in charge once in attach()
4942 ret
= mem_cgroup_do_precharge(1);
4950 static void mem_cgroup_move_charge(struct mm_struct
*mm
)
4952 struct mm_walk mem_cgroup_move_charge_walk
= {
4953 .pmd_entry
= mem_cgroup_move_charge_pte_range
,
4957 lru_add_drain_all();
4959 * Signal mem_cgroup_begin_page_stat() to take the memcg's
4960 * move_lock while we're moving its pages to another memcg.
4961 * Then wait for already started RCU-only updates to finish.
4963 atomic_inc(&mc
.from
->moving_account
);
4966 if (unlikely(!down_read_trylock(&mm
->mmap_sem
))) {
4968 * Someone who are holding the mmap_sem might be waiting in
4969 * waitq. So we cancel all extra charges, wake up all waiters,
4970 * and retry. Because we cancel precharges, we might not be able
4971 * to move enough charges, but moving charge is a best-effort
4972 * feature anyway, so it wouldn't be a big problem.
4974 __mem_cgroup_clear_mc();
4979 * When we have consumed all precharges and failed in doing
4980 * additional charge, the page walk just aborts.
4982 walk_page_range(0, ~0UL, &mem_cgroup_move_charge_walk
);
4983 up_read(&mm
->mmap_sem
);
4984 atomic_dec(&mc
.from
->moving_account
);
4987 static void mem_cgroup_move_task(struct cgroup_taskset
*tset
)
4989 struct cgroup_subsys_state
*css
;
4990 struct task_struct
*p
= cgroup_taskset_first(tset
, &css
);
4991 struct mm_struct
*mm
= get_task_mm(p
);
4995 mem_cgroup_move_charge(mm
);
4999 mem_cgroup_clear_mc();
5001 #else /* !CONFIG_MMU */
5002 static int mem_cgroup_can_attach(struct cgroup_taskset
*tset
)
5006 static void mem_cgroup_cancel_attach(struct cgroup_taskset
*tset
)
5009 static void mem_cgroup_move_task(struct cgroup_taskset
*tset
)
5015 * Cgroup retains root cgroups across [un]mount cycles making it necessary
5016 * to verify whether we're attached to the default hierarchy on each mount
5019 static void mem_cgroup_bind(struct cgroup_subsys_state
*root_css
)
5022 * use_hierarchy is forced on the default hierarchy. cgroup core
5023 * guarantees that @root doesn't have any children, so turning it
5024 * on for the root memcg is enough.
5026 if (cgroup_subsys_on_dfl(memory_cgrp_subsys
))
5027 root_mem_cgroup
->use_hierarchy
= true;
5029 root_mem_cgroup
->use_hierarchy
= false;
5032 static u64
memory_current_read(struct cgroup_subsys_state
*css
,
5035 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
5037 return (u64
)page_counter_read(&memcg
->memory
) * PAGE_SIZE
;
5040 static int memory_low_show(struct seq_file
*m
, void *v
)
5042 struct mem_cgroup
*memcg
= mem_cgroup_from_css(seq_css(m
));
5043 unsigned long low
= READ_ONCE(memcg
->low
);
5045 if (low
== PAGE_COUNTER_MAX
)
5046 seq_puts(m
, "max\n");
5048 seq_printf(m
, "%llu\n", (u64
)low
* PAGE_SIZE
);
5053 static ssize_t
memory_low_write(struct kernfs_open_file
*of
,
5054 char *buf
, size_t nbytes
, loff_t off
)
5056 struct mem_cgroup
*memcg
= mem_cgroup_from_css(of_css(of
));
5060 buf
= strstrip(buf
);
5061 err
= page_counter_memparse(buf
, "max", &low
);
5070 static int memory_high_show(struct seq_file
*m
, void *v
)
5072 struct mem_cgroup
*memcg
= mem_cgroup_from_css(seq_css(m
));
5073 unsigned long high
= READ_ONCE(memcg
->high
);
5075 if (high
== PAGE_COUNTER_MAX
)
5076 seq_puts(m
, "max\n");
5078 seq_printf(m
, "%llu\n", (u64
)high
* PAGE_SIZE
);
5083 static ssize_t
memory_high_write(struct kernfs_open_file
*of
,
5084 char *buf
, size_t nbytes
, loff_t off
)
5086 struct mem_cgroup
*memcg
= mem_cgroup_from_css(of_css(of
));
5090 buf
= strstrip(buf
);
5091 err
= page_counter_memparse(buf
, "max", &high
);
5097 memcg_wb_domain_size_changed(memcg
);
5101 static int memory_max_show(struct seq_file
*m
, void *v
)
5103 struct mem_cgroup
*memcg
= mem_cgroup_from_css(seq_css(m
));
5104 unsigned long max
= READ_ONCE(memcg
->memory
.limit
);
5106 if (max
== PAGE_COUNTER_MAX
)
5107 seq_puts(m
, "max\n");
5109 seq_printf(m
, "%llu\n", (u64
)max
* PAGE_SIZE
);
5114 static ssize_t
memory_max_write(struct kernfs_open_file
*of
,
5115 char *buf
, size_t nbytes
, loff_t off
)
5117 struct mem_cgroup
*memcg
= mem_cgroup_from_css(of_css(of
));
5121 buf
= strstrip(buf
);
5122 err
= page_counter_memparse(buf
, "max", &max
);
5126 err
= mem_cgroup_resize_limit(memcg
, max
);
5130 memcg_wb_domain_size_changed(memcg
);
5134 static int memory_events_show(struct seq_file
*m
, void *v
)
5136 struct mem_cgroup
*memcg
= mem_cgroup_from_css(seq_css(m
));
5138 seq_printf(m
, "low %lu\n", mem_cgroup_read_events(memcg
, MEMCG_LOW
));
5139 seq_printf(m
, "high %lu\n", mem_cgroup_read_events(memcg
, MEMCG_HIGH
));
5140 seq_printf(m
, "max %lu\n", mem_cgroup_read_events(memcg
, MEMCG_MAX
));
5141 seq_printf(m
, "oom %lu\n", mem_cgroup_read_events(memcg
, MEMCG_OOM
));
5146 static struct cftype memory_files
[] = {
5149 .flags
= CFTYPE_NOT_ON_ROOT
,
5150 .read_u64
= memory_current_read
,
5154 .flags
= CFTYPE_NOT_ON_ROOT
,
5155 .seq_show
= memory_low_show
,
5156 .write
= memory_low_write
,
5160 .flags
= CFTYPE_NOT_ON_ROOT
,
5161 .seq_show
= memory_high_show
,
5162 .write
= memory_high_write
,
5166 .flags
= CFTYPE_NOT_ON_ROOT
,
5167 .seq_show
= memory_max_show
,
5168 .write
= memory_max_write
,
5172 .flags
= CFTYPE_NOT_ON_ROOT
,
5173 .file_offset
= offsetof(struct mem_cgroup
, events_file
),
5174 .seq_show
= memory_events_show
,
5179 struct cgroup_subsys memory_cgrp_subsys
= {
5180 .css_alloc
= mem_cgroup_css_alloc
,
5181 .css_online
= mem_cgroup_css_online
,
5182 .css_offline
= mem_cgroup_css_offline
,
5183 .css_released
= mem_cgroup_css_released
,
5184 .css_free
= mem_cgroup_css_free
,
5185 .css_reset
= mem_cgroup_css_reset
,
5186 .can_attach
= mem_cgroup_can_attach
,
5187 .cancel_attach
= mem_cgroup_cancel_attach
,
5188 .attach
= mem_cgroup_move_task
,
5189 .bind
= mem_cgroup_bind
,
5190 .dfl_cftypes
= memory_files
,
5191 .legacy_cftypes
= mem_cgroup_legacy_files
,
5196 * mem_cgroup_low - check if memory consumption is below the normal range
5197 * @root: the highest ancestor to consider
5198 * @memcg: the memory cgroup to check
5200 * Returns %true if memory consumption of @memcg, and that of all
5201 * configurable ancestors up to @root, is below the normal range.
5203 bool mem_cgroup_low(struct mem_cgroup
*root
, struct mem_cgroup
*memcg
)
5205 if (mem_cgroup_disabled())
5209 * The toplevel group doesn't have a configurable range, so
5210 * it's never low when looked at directly, and it is not
5211 * considered an ancestor when assessing the hierarchy.
5214 if (memcg
== root_mem_cgroup
)
5217 if (page_counter_read(&memcg
->memory
) >= memcg
->low
)
5220 while (memcg
!= root
) {
5221 memcg
= parent_mem_cgroup(memcg
);
5223 if (memcg
== root_mem_cgroup
)
5226 if (page_counter_read(&memcg
->memory
) >= memcg
->low
)
5233 * mem_cgroup_try_charge - try charging a page
5234 * @page: page to charge
5235 * @mm: mm context of the victim
5236 * @gfp_mask: reclaim mode
5237 * @memcgp: charged memcg return
5239 * Try to charge @page to the memcg that @mm belongs to, reclaiming
5240 * pages according to @gfp_mask if necessary.
5242 * Returns 0 on success, with *@memcgp pointing to the charged memcg.
5243 * Otherwise, an error code is returned.
5245 * After page->mapping has been set up, the caller must finalize the
5246 * charge with mem_cgroup_commit_charge(). Or abort the transaction
5247 * with mem_cgroup_cancel_charge() in case page instantiation fails.
5249 int mem_cgroup_try_charge(struct page
*page
, struct mm_struct
*mm
,
5250 gfp_t gfp_mask
, struct mem_cgroup
**memcgp
,
5253 struct mem_cgroup
*memcg
= NULL
;
5254 unsigned int nr_pages
= compound
? hpage_nr_pages(page
) : 1;
5257 if (mem_cgroup_disabled())
5260 if (PageSwapCache(page
)) {
5262 * Every swap fault against a single page tries to charge the
5263 * page, bail as early as possible. shmem_unuse() encounters
5264 * already charged pages, too. The USED bit is protected by
5265 * the page lock, which serializes swap cache removal, which
5266 * in turn serializes uncharging.
5268 VM_BUG_ON_PAGE(!PageLocked(page
), page
);
5269 if (page
->mem_cgroup
)
5272 if (do_memsw_account()) {
5273 swp_entry_t ent
= { .val
= page_private(page
), };
5274 unsigned short id
= lookup_swap_cgroup_id(ent
);
5277 memcg
= mem_cgroup_from_id(id
);
5278 if (memcg
&& !css_tryget_online(&memcg
->css
))
5285 memcg
= get_mem_cgroup_from_mm(mm
);
5287 ret
= try_charge(memcg
, gfp_mask
, nr_pages
);
5289 css_put(&memcg
->css
);
5296 * mem_cgroup_commit_charge - commit a page charge
5297 * @page: page to charge
5298 * @memcg: memcg to charge the page to
5299 * @lrucare: page might be on LRU already
5301 * Finalize a charge transaction started by mem_cgroup_try_charge(),
5302 * after page->mapping has been set up. This must happen atomically
5303 * as part of the page instantiation, i.e. under the page table lock
5304 * for anonymous pages, under the page lock for page and swap cache.
5306 * In addition, the page must not be on the LRU during the commit, to
5307 * prevent racing with task migration. If it might be, use @lrucare.
5309 * Use mem_cgroup_cancel_charge() to cancel the transaction instead.
5311 void mem_cgroup_commit_charge(struct page
*page
, struct mem_cgroup
*memcg
,
5312 bool lrucare
, bool compound
)
5314 unsigned int nr_pages
= compound
? hpage_nr_pages(page
) : 1;
5316 VM_BUG_ON_PAGE(!page
->mapping
, page
);
5317 VM_BUG_ON_PAGE(PageLRU(page
) && !lrucare
, page
);
5319 if (mem_cgroup_disabled())
5322 * Swap faults will attempt to charge the same page multiple
5323 * times. But reuse_swap_page() might have removed the page
5324 * from swapcache already, so we can't check PageSwapCache().
5329 commit_charge(page
, memcg
, lrucare
);
5331 local_irq_disable();
5332 mem_cgroup_charge_statistics(memcg
, page
, compound
, nr_pages
);
5333 memcg_check_events(memcg
, page
);
5336 if (do_memsw_account() && PageSwapCache(page
)) {
5337 swp_entry_t entry
= { .val
= page_private(page
) };
5339 * The swap entry might not get freed for a long time,
5340 * let's not wait for it. The page already received a
5341 * memory+swap charge, drop the swap entry duplicate.
5343 mem_cgroup_uncharge_swap(entry
);
5348 * mem_cgroup_cancel_charge - cancel a page charge
5349 * @page: page to charge
5350 * @memcg: memcg to charge the page to
5352 * Cancel a charge transaction started by mem_cgroup_try_charge().
5354 void mem_cgroup_cancel_charge(struct page
*page
, struct mem_cgroup
*memcg
,
5357 unsigned int nr_pages
= compound
? hpage_nr_pages(page
) : 1;
5359 if (mem_cgroup_disabled())
5362 * Swap faults will attempt to charge the same page multiple
5363 * times. But reuse_swap_page() might have removed the page
5364 * from swapcache already, so we can't check PageSwapCache().
5369 cancel_charge(memcg
, nr_pages
);
5372 static void uncharge_batch(struct mem_cgroup
*memcg
, unsigned long pgpgout
,
5373 unsigned long nr_anon
, unsigned long nr_file
,
5374 unsigned long nr_huge
, struct page
*dummy_page
)
5376 unsigned long nr_pages
= nr_anon
+ nr_file
;
5377 unsigned long flags
;
5379 if (!mem_cgroup_is_root(memcg
)) {
5380 page_counter_uncharge(&memcg
->memory
, nr_pages
);
5381 if (do_memsw_account())
5382 page_counter_uncharge(&memcg
->memsw
, nr_pages
);
5383 memcg_oom_recover(memcg
);
5386 local_irq_save(flags
);
5387 __this_cpu_sub(memcg
->stat
->count
[MEM_CGROUP_STAT_RSS
], nr_anon
);
5388 __this_cpu_sub(memcg
->stat
->count
[MEM_CGROUP_STAT_CACHE
], nr_file
);
5389 __this_cpu_sub(memcg
->stat
->count
[MEM_CGROUP_STAT_RSS_HUGE
], nr_huge
);
5390 __this_cpu_add(memcg
->stat
->events
[MEM_CGROUP_EVENTS_PGPGOUT
], pgpgout
);
5391 __this_cpu_add(memcg
->stat
->nr_page_events
, nr_pages
);
5392 memcg_check_events(memcg
, dummy_page
);
5393 local_irq_restore(flags
);
5395 if (!mem_cgroup_is_root(memcg
))
5396 css_put_many(&memcg
->css
, nr_pages
);
5399 static void uncharge_list(struct list_head
*page_list
)
5401 struct mem_cgroup
*memcg
= NULL
;
5402 unsigned long nr_anon
= 0;
5403 unsigned long nr_file
= 0;
5404 unsigned long nr_huge
= 0;
5405 unsigned long pgpgout
= 0;
5406 struct list_head
*next
;
5409 next
= page_list
->next
;
5411 unsigned int nr_pages
= 1;
5413 page
= list_entry(next
, struct page
, lru
);
5414 next
= page
->lru
.next
;
5416 VM_BUG_ON_PAGE(PageLRU(page
), page
);
5417 VM_BUG_ON_PAGE(page_count(page
), page
);
5419 if (!page
->mem_cgroup
)
5423 * Nobody should be changing or seriously looking at
5424 * page->mem_cgroup at this point, we have fully
5425 * exclusive access to the page.
5428 if (memcg
!= page
->mem_cgroup
) {
5430 uncharge_batch(memcg
, pgpgout
, nr_anon
, nr_file
,
5432 pgpgout
= nr_anon
= nr_file
= nr_huge
= 0;
5434 memcg
= page
->mem_cgroup
;
5437 if (PageTransHuge(page
)) {
5438 nr_pages
<<= compound_order(page
);
5439 VM_BUG_ON_PAGE(!PageTransHuge(page
), page
);
5440 nr_huge
+= nr_pages
;
5444 nr_anon
+= nr_pages
;
5446 nr_file
+= nr_pages
;
5448 page
->mem_cgroup
= NULL
;
5451 } while (next
!= page_list
);
5454 uncharge_batch(memcg
, pgpgout
, nr_anon
, nr_file
,
5459 * mem_cgroup_uncharge - uncharge a page
5460 * @page: page to uncharge
5462 * Uncharge a page previously charged with mem_cgroup_try_charge() and
5463 * mem_cgroup_commit_charge().
5465 void mem_cgroup_uncharge(struct page
*page
)
5467 if (mem_cgroup_disabled())
5470 /* Don't touch page->lru of any random page, pre-check: */
5471 if (!page
->mem_cgroup
)
5474 INIT_LIST_HEAD(&page
->lru
);
5475 uncharge_list(&page
->lru
);
5479 * mem_cgroup_uncharge_list - uncharge a list of page
5480 * @page_list: list of pages to uncharge
5482 * Uncharge a list of pages previously charged with
5483 * mem_cgroup_try_charge() and mem_cgroup_commit_charge().
5485 void mem_cgroup_uncharge_list(struct list_head
*page_list
)
5487 if (mem_cgroup_disabled())
5490 if (!list_empty(page_list
))
5491 uncharge_list(page_list
);
5495 * mem_cgroup_replace_page - migrate a charge to another page
5496 * @oldpage: currently charged page
5497 * @newpage: page to transfer the charge to
5499 * Migrate the charge from @oldpage to @newpage.
5501 * Both pages must be locked, @newpage->mapping must be set up.
5502 * Either or both pages might be on the LRU already.
5504 void mem_cgroup_replace_page(struct page
*oldpage
, struct page
*newpage
)
5506 struct mem_cgroup
*memcg
;
5509 VM_BUG_ON_PAGE(!PageLocked(oldpage
), oldpage
);
5510 VM_BUG_ON_PAGE(!PageLocked(newpage
), newpage
);
5511 VM_BUG_ON_PAGE(PageAnon(oldpage
) != PageAnon(newpage
), newpage
);
5512 VM_BUG_ON_PAGE(PageTransHuge(oldpage
) != PageTransHuge(newpage
),
5515 if (mem_cgroup_disabled())
5518 /* Page cache replacement: new page already charged? */
5519 if (newpage
->mem_cgroup
)
5522 /* Swapcache readahead pages can get replaced before being charged */
5523 memcg
= oldpage
->mem_cgroup
;
5527 lock_page_lru(oldpage
, &isolated
);
5528 oldpage
->mem_cgroup
= NULL
;
5529 unlock_page_lru(oldpage
, isolated
);
5531 commit_charge(newpage
, memcg
, true);
5536 DEFINE_STATIC_KEY_FALSE(memcg_sockets_enabled_key
);
5537 EXPORT_SYMBOL(memcg_sockets_enabled_key
);
5539 void sock_update_memcg(struct sock
*sk
)
5541 struct mem_cgroup
*memcg
;
5543 /* Socket cloning can throw us here with sk_cgrp already
5544 * filled. It won't however, necessarily happen from
5545 * process context. So the test for root memcg given
5546 * the current task's memcg won't help us in this case.
5548 * Respecting the original socket's memcg is a better
5549 * decision in this case.
5552 BUG_ON(mem_cgroup_is_root(sk
->sk_memcg
));
5553 css_get(&sk
->sk_memcg
->css
);
5558 memcg
= mem_cgroup_from_task(current
);
5559 if (memcg
== root_mem_cgroup
)
5561 #ifdef CONFIG_MEMCG_KMEM
5562 if (!cgroup_subsys_on_dfl(memory_cgrp_subsys
) && !memcg
->tcp_mem
.active
)
5565 if (css_tryget_online(&memcg
->css
))
5566 sk
->sk_memcg
= memcg
;
5570 EXPORT_SYMBOL(sock_update_memcg
);
5572 void sock_release_memcg(struct sock
*sk
)
5574 WARN_ON(!sk
->sk_memcg
);
5575 css_put(&sk
->sk_memcg
->css
);
5579 * mem_cgroup_charge_skmem - charge socket memory
5580 * @memcg: memcg to charge
5581 * @nr_pages: number of pages to charge
5583 * Charges @nr_pages to @memcg. Returns %true if the charge fit within
5584 * @memcg's configured limit, %false if the charge had to be forced.
5586 bool mem_cgroup_charge_skmem(struct mem_cgroup
*memcg
, unsigned int nr_pages
)
5588 gfp_t gfp_mask
= GFP_KERNEL
;
5590 #ifdef CONFIG_MEMCG_KMEM
5591 if (!cgroup_subsys_on_dfl(memory_cgrp_subsys
)) {
5592 struct page_counter
*counter
;
5594 if (page_counter_try_charge(&memcg
->tcp_mem
.memory_allocated
,
5595 nr_pages
, &counter
)) {
5596 memcg
->tcp_mem
.memory_pressure
= 0;
5599 page_counter_charge(&memcg
->tcp_mem
.memory_allocated
, nr_pages
);
5600 memcg
->tcp_mem
.memory_pressure
= 1;
5604 /* Don't block in the packet receive path */
5606 gfp_mask
= GFP_NOWAIT
;
5608 if (try_charge(memcg
, gfp_mask
, nr_pages
) == 0)
5611 try_charge(memcg
, gfp_mask
|__GFP_NOFAIL
, nr_pages
);
5616 * mem_cgroup_uncharge_skmem - uncharge socket memory
5617 * @memcg - memcg to uncharge
5618 * @nr_pages - number of pages to uncharge
5620 void mem_cgroup_uncharge_skmem(struct mem_cgroup
*memcg
, unsigned int nr_pages
)
5622 #ifdef CONFIG_MEMCG_KMEM
5623 if (!cgroup_subsys_on_dfl(memory_cgrp_subsys
)) {
5624 page_counter_uncharge(&memcg
->tcp_mem
.memory_allocated
,
5629 page_counter_uncharge(&memcg
->memory
, nr_pages
);
5630 css_put_many(&memcg
->css
, nr_pages
);
5633 #endif /* CONFIG_INET */
5635 static int __init
cgroup_memory(char *s
)
5639 while ((token
= strsep(&s
, ",")) != NULL
) {
5642 if (!strcmp(token
, "nosocket"))
5643 cgroup_memory_nosocket
= true;
5647 __setup("cgroup.memory=", cgroup_memory
);
5650 * subsys_initcall() for memory controller.
5652 * Some parts like hotcpu_notifier() have to be initialized from this context
5653 * because of lock dependencies (cgroup_lock -> cpu hotplug) but basically
5654 * everything that doesn't depend on a specific mem_cgroup structure should
5655 * be initialized from here.
5657 static int __init
mem_cgroup_init(void)
5661 hotcpu_notifier(memcg_cpu_hotplug_callback
, 0);
5663 for_each_possible_cpu(cpu
)
5664 INIT_WORK(&per_cpu_ptr(&memcg_stock
, cpu
)->work
,
5667 for_each_node(node
) {
5668 struct mem_cgroup_tree_per_node
*rtpn
;
5671 rtpn
= kzalloc_node(sizeof(*rtpn
), GFP_KERNEL
,
5672 node_online(node
) ? node
: NUMA_NO_NODE
);
5674 for (zone
= 0; zone
< MAX_NR_ZONES
; zone
++) {
5675 struct mem_cgroup_tree_per_zone
*rtpz
;
5677 rtpz
= &rtpn
->rb_tree_per_zone
[zone
];
5678 rtpz
->rb_root
= RB_ROOT
;
5679 spin_lock_init(&rtpz
->lock
);
5681 soft_limit_tree
.rb_tree_per_node
[node
] = rtpn
;
5686 subsys_initcall(mem_cgroup_init
);
5688 #ifdef CONFIG_MEMCG_SWAP
5690 * mem_cgroup_swapout - transfer a memsw charge to swap
5691 * @page: page whose memsw charge to transfer
5692 * @entry: swap entry to move the charge to
5694 * Transfer the memsw charge of @page to @entry.
5696 void mem_cgroup_swapout(struct page
*page
, swp_entry_t entry
)
5698 struct mem_cgroup
*memcg
;
5699 unsigned short oldid
;
5701 VM_BUG_ON_PAGE(PageLRU(page
), page
);
5702 VM_BUG_ON_PAGE(page_count(page
), page
);
5704 if (!do_memsw_account())
5707 memcg
= page
->mem_cgroup
;
5709 /* Readahead page, never charged */
5713 oldid
= swap_cgroup_record(entry
, mem_cgroup_id(memcg
));
5714 VM_BUG_ON_PAGE(oldid
, page
);
5715 mem_cgroup_swap_statistics(memcg
, true);
5717 page
->mem_cgroup
= NULL
;
5719 if (!mem_cgroup_is_root(memcg
))
5720 page_counter_uncharge(&memcg
->memory
, 1);
5723 * Interrupts should be disabled here because the caller holds the
5724 * mapping->tree_lock lock which is taken with interrupts-off. It is
5725 * important here to have the interrupts disabled because it is the
5726 * only synchronisation we have for udpating the per-CPU variables.
5728 VM_BUG_ON(!irqs_disabled());
5729 mem_cgroup_charge_statistics(memcg
, page
, false, -1);
5730 memcg_check_events(memcg
, page
);
5734 * mem_cgroup_uncharge_swap - uncharge a swap entry
5735 * @entry: swap entry to uncharge
5737 * Drop the memsw charge associated with @entry.
5739 void mem_cgroup_uncharge_swap(swp_entry_t entry
)
5741 struct mem_cgroup
*memcg
;
5744 if (!do_memsw_account())
5747 id
= swap_cgroup_record(entry
, 0);
5749 memcg
= mem_cgroup_from_id(id
);
5751 if (!mem_cgroup_is_root(memcg
))
5752 page_counter_uncharge(&memcg
->memsw
, 1);
5753 mem_cgroup_swap_statistics(memcg
, false);
5754 css_put(&memcg
->css
);
5759 /* for remember boot option*/
5760 #ifdef CONFIG_MEMCG_SWAP_ENABLED
5761 static int really_do_swap_account __initdata
= 1;
5763 static int really_do_swap_account __initdata
;
5766 static int __init
enable_swap_account(char *s
)
5768 if (!strcmp(s
, "1"))
5769 really_do_swap_account
= 1;
5770 else if (!strcmp(s
, "0"))
5771 really_do_swap_account
= 0;
5774 __setup("swapaccount=", enable_swap_account
);
5776 static struct cftype memsw_cgroup_files
[] = {
5778 .name
= "memsw.usage_in_bytes",
5779 .private = MEMFILE_PRIVATE(_MEMSWAP
, RES_USAGE
),
5780 .read_u64
= mem_cgroup_read_u64
,
5783 .name
= "memsw.max_usage_in_bytes",
5784 .private = MEMFILE_PRIVATE(_MEMSWAP
, RES_MAX_USAGE
),
5785 .write
= mem_cgroup_reset
,
5786 .read_u64
= mem_cgroup_read_u64
,
5789 .name
= "memsw.limit_in_bytes",
5790 .private = MEMFILE_PRIVATE(_MEMSWAP
, RES_LIMIT
),
5791 .write
= mem_cgroup_write
,
5792 .read_u64
= mem_cgroup_read_u64
,
5795 .name
= "memsw.failcnt",
5796 .private = MEMFILE_PRIVATE(_MEMSWAP
, RES_FAILCNT
),
5797 .write
= mem_cgroup_reset
,
5798 .read_u64
= mem_cgroup_read_u64
,
5800 { }, /* terminate */
5803 static int __init
mem_cgroup_swap_init(void)
5805 if (!mem_cgroup_disabled() && really_do_swap_account
) {
5806 do_swap_account
= 1;
5807 WARN_ON(cgroup_add_legacy_cftypes(&memory_cgrp_subsys
,
5808 memsw_cgroup_files
));
5812 subsys_initcall(mem_cgroup_swap_init
);
5814 #endif /* CONFIG_MEMCG_SWAP */