1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /* memcontrol.c - Memory Controller
4 * Copyright IBM Corporation, 2007
5 * Author Balbir Singh <balbir@linux.vnet.ibm.com>
7 * Copyright 2007 OpenVZ SWsoft Inc
8 * Author: Pavel Emelianov <xemul@openvz.org>
11 * Copyright (C) 2009 Nokia Corporation
12 * Author: Kirill A. Shutemov
14 * Kernel Memory Controller
15 * Copyright (C) 2012 Parallels Inc. and Google Inc.
16 * Authors: Glauber Costa and Suleiman Souhlal
19 * Charge lifetime sanitation
20 * Lockless page tracking & accounting
21 * Unified hierarchy configuration model
22 * Copyright (C) 2015 Red Hat, Inc., Johannes Weiner
25 #include <linux/page_counter.h>
26 #include <linux/memcontrol.h>
27 #include <linux/cgroup.h>
28 #include <linux/pagewalk.h>
29 #include <linux/sched/mm.h>
30 #include <linux/shmem_fs.h>
31 #include <linux/hugetlb.h>
32 #include <linux/pagemap.h>
33 #include <linux/vm_event_item.h>
34 #include <linux/smp.h>
35 #include <linux/page-flags.h>
36 #include <linux/backing-dev.h>
37 #include <linux/bit_spinlock.h>
38 #include <linux/rcupdate.h>
39 #include <linux/limits.h>
40 #include <linux/export.h>
41 #include <linux/mutex.h>
42 #include <linux/rbtree.h>
43 #include <linux/slab.h>
44 #include <linux/swap.h>
45 #include <linux/swapops.h>
46 #include <linux/spinlock.h>
47 #include <linux/eventfd.h>
48 #include <linux/poll.h>
49 #include <linux/sort.h>
51 #include <linux/seq_file.h>
52 #include <linux/vmpressure.h>
53 #include <linux/mm_inline.h>
54 #include <linux/swap_cgroup.h>
55 #include <linux/cpu.h>
56 #include <linux/oom.h>
57 #include <linux/lockdep.h>
58 #include <linux/file.h>
59 #include <linux/tracehook.h>
60 #include <linux/psi.h>
61 #include <linux/seq_buf.h>
67 #include <linux/uaccess.h>
69 #include <trace/events/vmscan.h>
71 struct cgroup_subsys memory_cgrp_subsys __read_mostly
;
72 EXPORT_SYMBOL(memory_cgrp_subsys
);
74 struct mem_cgroup
*root_mem_cgroup __read_mostly
;
76 /* Active memory cgroup to use from an interrupt context */
77 DEFINE_PER_CPU(struct mem_cgroup
*, int_active_memcg
);
79 /* Socket memory accounting disabled? */
80 static bool cgroup_memory_nosocket
;
82 /* Kernel memory accounting disabled? */
83 static bool cgroup_memory_nokmem
;
85 /* Whether the swap controller is active */
86 #ifdef CONFIG_MEMCG_SWAP
87 bool cgroup_memory_noswap __read_mostly
;
89 #define cgroup_memory_noswap 1
92 #ifdef CONFIG_CGROUP_WRITEBACK
93 static DECLARE_WAIT_QUEUE_HEAD(memcg_cgwb_frn_waitq
);
96 /* Whether legacy memory+swap accounting is active */
97 static bool do_memsw_account(void)
99 return !cgroup_subsys_on_dfl(memory_cgrp_subsys
) && !cgroup_memory_noswap
;
102 #define THRESHOLDS_EVENTS_TARGET 128
103 #define SOFTLIMIT_EVENTS_TARGET 1024
106 * Cgroups above their limits are maintained in a RB-Tree, independent of
107 * their hierarchy representation
110 struct mem_cgroup_tree_per_node
{
111 struct rb_root rb_root
;
112 struct rb_node
*rb_rightmost
;
116 struct mem_cgroup_tree
{
117 struct mem_cgroup_tree_per_node
*rb_tree_per_node
[MAX_NUMNODES
];
120 static struct mem_cgroup_tree soft_limit_tree __read_mostly
;
123 struct mem_cgroup_eventfd_list
{
124 struct list_head list
;
125 struct eventfd_ctx
*eventfd
;
129 * cgroup_event represents events which userspace want to receive.
131 struct mem_cgroup_event
{
133 * memcg which the event belongs to.
135 struct mem_cgroup
*memcg
;
137 * eventfd to signal userspace about the event.
139 struct eventfd_ctx
*eventfd
;
141 * Each of these stored in a list by the cgroup.
143 struct list_head list
;
145 * register_event() callback will be used to add new userspace
146 * waiter for changes related to this event. Use eventfd_signal()
147 * on eventfd to send notification to userspace.
149 int (*register_event
)(struct mem_cgroup
*memcg
,
150 struct eventfd_ctx
*eventfd
, const char *args
);
152 * unregister_event() callback will be called when userspace closes
153 * the eventfd or on cgroup removing. This callback must be set,
154 * if you want provide notification functionality.
156 void (*unregister_event
)(struct mem_cgroup
*memcg
,
157 struct eventfd_ctx
*eventfd
);
159 * All fields below needed to unregister event when
160 * userspace closes eventfd.
163 wait_queue_head_t
*wqh
;
164 wait_queue_entry_t wait
;
165 struct work_struct remove
;
168 static void mem_cgroup_threshold(struct mem_cgroup
*memcg
);
169 static void mem_cgroup_oom_notify(struct mem_cgroup
*memcg
);
171 /* Stuffs for move charges at task migration. */
173 * Types of charges to be moved.
175 #define MOVE_ANON 0x1U
176 #define MOVE_FILE 0x2U
177 #define MOVE_MASK (MOVE_ANON | MOVE_FILE)
179 /* "mc" and its members are protected by cgroup_mutex */
180 static struct move_charge_struct
{
181 spinlock_t lock
; /* for from, to */
182 struct mm_struct
*mm
;
183 struct mem_cgroup
*from
;
184 struct mem_cgroup
*to
;
186 unsigned long precharge
;
187 unsigned long moved_charge
;
188 unsigned long moved_swap
;
189 struct task_struct
*moving_task
; /* a task moving charges */
190 wait_queue_head_t waitq
; /* a waitq for other context */
192 .lock
= __SPIN_LOCK_UNLOCKED(mc
.lock
),
193 .waitq
= __WAIT_QUEUE_HEAD_INITIALIZER(mc
.waitq
),
197 * Maximum loops in mem_cgroup_hierarchical_reclaim(), used for soft
198 * limit reclaim to prevent infinite loops, if they ever occur.
200 #define MEM_CGROUP_MAX_RECLAIM_LOOPS 100
201 #define MEM_CGROUP_MAX_SOFT_LIMIT_RECLAIM_LOOPS 2
203 /* for encoding cft->private value on file */
212 #define MEMFILE_PRIVATE(x, val) ((x) << 16 | (val))
213 #define MEMFILE_TYPE(val) ((val) >> 16 & 0xffff)
214 #define MEMFILE_ATTR(val) ((val) & 0xffff)
215 /* Used for OOM nofiier */
216 #define OOM_CONTROL (0)
219 * Iteration constructs for visiting all cgroups (under a tree). If
220 * loops are exited prematurely (break), mem_cgroup_iter_break() must
221 * be used for reference counting.
223 #define for_each_mem_cgroup_tree(iter, root) \
224 for (iter = mem_cgroup_iter(root, NULL, NULL); \
226 iter = mem_cgroup_iter(root, iter, NULL))
228 #define for_each_mem_cgroup(iter) \
229 for (iter = mem_cgroup_iter(NULL, NULL, NULL); \
231 iter = mem_cgroup_iter(NULL, iter, NULL))
233 static inline bool should_force_charge(void)
235 return tsk_is_oom_victim(current
) || fatal_signal_pending(current
) ||
236 (current
->flags
& PF_EXITING
);
239 /* Some nice accessors for the vmpressure. */
240 struct vmpressure
*memcg_to_vmpressure(struct mem_cgroup
*memcg
)
243 memcg
= root_mem_cgroup
;
244 return &memcg
->vmpressure
;
247 struct cgroup_subsys_state
*vmpressure_to_css(struct vmpressure
*vmpr
)
249 return &container_of(vmpr
, struct mem_cgroup
, vmpressure
)->css
;
252 #ifdef CONFIG_MEMCG_KMEM
253 extern spinlock_t css_set_lock
;
255 static void obj_cgroup_release(struct percpu_ref
*ref
)
257 struct obj_cgroup
*objcg
= container_of(ref
, struct obj_cgroup
, refcnt
);
258 struct mem_cgroup
*memcg
;
259 unsigned int nr_bytes
;
260 unsigned int nr_pages
;
264 * At this point all allocated objects are freed, and
265 * objcg->nr_charged_bytes can't have an arbitrary byte value.
266 * However, it can be PAGE_SIZE or (x * PAGE_SIZE).
268 * The following sequence can lead to it:
269 * 1) CPU0: objcg == stock->cached_objcg
270 * 2) CPU1: we do a small allocation (e.g. 92 bytes),
271 * PAGE_SIZE bytes are charged
272 * 3) CPU1: a process from another memcg is allocating something,
273 * the stock if flushed,
274 * objcg->nr_charged_bytes = PAGE_SIZE - 92
275 * 5) CPU0: we do release this object,
276 * 92 bytes are added to stock->nr_bytes
277 * 6) CPU0: stock is flushed,
278 * 92 bytes are added to objcg->nr_charged_bytes
280 * In the result, nr_charged_bytes == PAGE_SIZE.
281 * This page will be uncharged in obj_cgroup_release().
283 nr_bytes
= atomic_read(&objcg
->nr_charged_bytes
);
284 WARN_ON_ONCE(nr_bytes
& (PAGE_SIZE
- 1));
285 nr_pages
= nr_bytes
>> PAGE_SHIFT
;
287 spin_lock_irqsave(&css_set_lock
, flags
);
288 memcg
= obj_cgroup_memcg(objcg
);
290 __memcg_kmem_uncharge(memcg
, nr_pages
);
291 list_del(&objcg
->list
);
292 mem_cgroup_put(memcg
);
293 spin_unlock_irqrestore(&css_set_lock
, flags
);
295 percpu_ref_exit(ref
);
296 kfree_rcu(objcg
, rcu
);
299 static struct obj_cgroup
*obj_cgroup_alloc(void)
301 struct obj_cgroup
*objcg
;
304 objcg
= kzalloc(sizeof(struct obj_cgroup
), GFP_KERNEL
);
308 ret
= percpu_ref_init(&objcg
->refcnt
, obj_cgroup_release
, 0,
314 INIT_LIST_HEAD(&objcg
->list
);
318 static void memcg_reparent_objcgs(struct mem_cgroup
*memcg
,
319 struct mem_cgroup
*parent
)
321 struct obj_cgroup
*objcg
, *iter
;
323 objcg
= rcu_replace_pointer(memcg
->objcg
, NULL
, true);
325 spin_lock_irq(&css_set_lock
);
327 /* Move active objcg to the parent's list */
328 xchg(&objcg
->memcg
, parent
);
329 css_get(&parent
->css
);
330 list_add(&objcg
->list
, &parent
->objcg_list
);
332 /* Move already reparented objcgs to the parent's list */
333 list_for_each_entry(iter
, &memcg
->objcg_list
, list
) {
334 css_get(&parent
->css
);
335 xchg(&iter
->memcg
, parent
);
336 css_put(&memcg
->css
);
338 list_splice(&memcg
->objcg_list
, &parent
->objcg_list
);
340 spin_unlock_irq(&css_set_lock
);
342 percpu_ref_kill(&objcg
->refcnt
);
346 * This will be used as a shrinker list's index.
347 * The main reason for not using cgroup id for this:
348 * this works better in sparse environments, where we have a lot of memcgs,
349 * but only a few kmem-limited. Or also, if we have, for instance, 200
350 * memcgs, and none but the 200th is kmem-limited, we'd have to have a
351 * 200 entry array for that.
353 * The current size of the caches array is stored in memcg_nr_cache_ids. It
354 * will double each time we have to increase it.
356 static DEFINE_IDA(memcg_cache_ida
);
357 int memcg_nr_cache_ids
;
359 /* Protects memcg_nr_cache_ids */
360 static DECLARE_RWSEM(memcg_cache_ids_sem
);
362 void memcg_get_cache_ids(void)
364 down_read(&memcg_cache_ids_sem
);
367 void memcg_put_cache_ids(void)
369 up_read(&memcg_cache_ids_sem
);
373 * MIN_SIZE is different than 1, because we would like to avoid going through
374 * the alloc/free process all the time. In a small machine, 4 kmem-limited
375 * cgroups is a reasonable guess. In the future, it could be a parameter or
376 * tunable, but that is strictly not necessary.
378 * MAX_SIZE should be as large as the number of cgrp_ids. Ideally, we could get
379 * this constant directly from cgroup, but it is understandable that this is
380 * better kept as an internal representation in cgroup.c. In any case, the
381 * cgrp_id space is not getting any smaller, and we don't have to necessarily
382 * increase ours as well if it increases.
384 #define MEMCG_CACHES_MIN_SIZE 4
385 #define MEMCG_CACHES_MAX_SIZE MEM_CGROUP_ID_MAX
388 * A lot of the calls to the cache allocation functions are expected to be
389 * inlined by the compiler. Since the calls to memcg_slab_pre_alloc_hook() are
390 * conditional to this static branch, we'll have to allow modules that does
391 * kmem_cache_alloc and the such to see this symbol as well
393 DEFINE_STATIC_KEY_FALSE(memcg_kmem_enabled_key
);
394 EXPORT_SYMBOL(memcg_kmem_enabled_key
);
397 static int memcg_shrinker_map_size
;
398 static DEFINE_MUTEX(memcg_shrinker_map_mutex
);
400 static void memcg_free_shrinker_map_rcu(struct rcu_head
*head
)
402 kvfree(container_of(head
, struct memcg_shrinker_map
, rcu
));
405 static int memcg_expand_one_shrinker_map(struct mem_cgroup
*memcg
,
406 int size
, int old_size
)
408 struct memcg_shrinker_map
*new, *old
;
411 lockdep_assert_held(&memcg_shrinker_map_mutex
);
414 old
= rcu_dereference_protected(
415 mem_cgroup_nodeinfo(memcg
, nid
)->shrinker_map
, true);
416 /* Not yet online memcg */
420 new = kvmalloc_node(sizeof(*new) + size
, GFP_KERNEL
, nid
);
424 /* Set all old bits, clear all new bits */
425 memset(new->map
, (int)0xff, old_size
);
426 memset((void *)new->map
+ old_size
, 0, size
- old_size
);
428 rcu_assign_pointer(memcg
->nodeinfo
[nid
]->shrinker_map
, new);
429 call_rcu(&old
->rcu
, memcg_free_shrinker_map_rcu
);
435 static void memcg_free_shrinker_maps(struct mem_cgroup
*memcg
)
437 struct mem_cgroup_per_node
*pn
;
438 struct memcg_shrinker_map
*map
;
441 if (mem_cgroup_is_root(memcg
))
445 pn
= mem_cgroup_nodeinfo(memcg
, nid
);
446 map
= rcu_dereference_protected(pn
->shrinker_map
, true);
449 rcu_assign_pointer(pn
->shrinker_map
, NULL
);
453 static int memcg_alloc_shrinker_maps(struct mem_cgroup
*memcg
)
455 struct memcg_shrinker_map
*map
;
456 int nid
, size
, ret
= 0;
458 if (mem_cgroup_is_root(memcg
))
461 mutex_lock(&memcg_shrinker_map_mutex
);
462 size
= memcg_shrinker_map_size
;
464 map
= kvzalloc_node(sizeof(*map
) + size
, GFP_KERNEL
, nid
);
466 memcg_free_shrinker_maps(memcg
);
470 rcu_assign_pointer(memcg
->nodeinfo
[nid
]->shrinker_map
, map
);
472 mutex_unlock(&memcg_shrinker_map_mutex
);
477 int memcg_expand_shrinker_maps(int new_id
)
479 int size
, old_size
, ret
= 0;
480 struct mem_cgroup
*memcg
;
482 size
= DIV_ROUND_UP(new_id
+ 1, BITS_PER_LONG
) * sizeof(unsigned long);
483 old_size
= memcg_shrinker_map_size
;
484 if (size
<= old_size
)
487 mutex_lock(&memcg_shrinker_map_mutex
);
488 if (!root_mem_cgroup
)
491 for_each_mem_cgroup(memcg
) {
492 if (mem_cgroup_is_root(memcg
))
494 ret
= memcg_expand_one_shrinker_map(memcg
, size
, old_size
);
496 mem_cgroup_iter_break(NULL
, memcg
);
502 memcg_shrinker_map_size
= size
;
503 mutex_unlock(&memcg_shrinker_map_mutex
);
507 void memcg_set_shrinker_bit(struct mem_cgroup
*memcg
, int nid
, int shrinker_id
)
509 if (shrinker_id
>= 0 && memcg
&& !mem_cgroup_is_root(memcg
)) {
510 struct memcg_shrinker_map
*map
;
513 map
= rcu_dereference(memcg
->nodeinfo
[nid
]->shrinker_map
);
514 /* Pairs with smp mb in shrink_slab() */
515 smp_mb__before_atomic();
516 set_bit(shrinker_id
, map
->map
);
522 * mem_cgroup_css_from_page - css of the memcg associated with a page
523 * @page: page of interest
525 * If memcg is bound to the default hierarchy, css of the memcg associated
526 * with @page is returned. The returned css remains associated with @page
527 * until it is released.
529 * If memcg is bound to a traditional hierarchy, the css of root_mem_cgroup
532 struct cgroup_subsys_state
*mem_cgroup_css_from_page(struct page
*page
)
534 struct mem_cgroup
*memcg
;
536 memcg
= page
->mem_cgroup
;
538 if (!memcg
|| !cgroup_subsys_on_dfl(memory_cgrp_subsys
))
539 memcg
= root_mem_cgroup
;
545 * page_cgroup_ino - return inode number of the memcg a page is charged to
548 * Look up the closest online ancestor of the memory cgroup @page is charged to
549 * and return its inode number or 0 if @page is not charged to any cgroup. It
550 * is safe to call this function without holding a reference to @page.
552 * Note, this function is inherently racy, because there is nothing to prevent
553 * the cgroup inode from getting torn down and potentially reallocated a moment
554 * after page_cgroup_ino() returns, so it only should be used by callers that
555 * do not care (such as procfs interfaces).
557 ino_t
page_cgroup_ino(struct page
*page
)
559 struct mem_cgroup
*memcg
;
560 unsigned long ino
= 0;
563 memcg
= page
->mem_cgroup
;
566 * The lowest bit set means that memcg isn't a valid
567 * memcg pointer, but a obj_cgroups pointer.
568 * In this case the page is shared and doesn't belong
569 * to any specific memory cgroup.
571 if ((unsigned long) memcg
& 0x1UL
)
574 while (memcg
&& !(memcg
->css
.flags
& CSS_ONLINE
))
575 memcg
= parent_mem_cgroup(memcg
);
577 ino
= cgroup_ino(memcg
->css
.cgroup
);
582 static struct mem_cgroup_per_node
*
583 mem_cgroup_page_nodeinfo(struct mem_cgroup
*memcg
, struct page
*page
)
585 int nid
= page_to_nid(page
);
587 return memcg
->nodeinfo
[nid
];
590 static struct mem_cgroup_tree_per_node
*
591 soft_limit_tree_node(int nid
)
593 return soft_limit_tree
.rb_tree_per_node
[nid
];
596 static struct mem_cgroup_tree_per_node
*
597 soft_limit_tree_from_page(struct page
*page
)
599 int nid
= page_to_nid(page
);
601 return soft_limit_tree
.rb_tree_per_node
[nid
];
604 static void __mem_cgroup_insert_exceeded(struct mem_cgroup_per_node
*mz
,
605 struct mem_cgroup_tree_per_node
*mctz
,
606 unsigned long new_usage_in_excess
)
608 struct rb_node
**p
= &mctz
->rb_root
.rb_node
;
609 struct rb_node
*parent
= NULL
;
610 struct mem_cgroup_per_node
*mz_node
;
611 bool rightmost
= true;
616 mz
->usage_in_excess
= new_usage_in_excess
;
617 if (!mz
->usage_in_excess
)
621 mz_node
= rb_entry(parent
, struct mem_cgroup_per_node
,
623 if (mz
->usage_in_excess
< mz_node
->usage_in_excess
) {
629 * We can't avoid mem cgroups that are over their soft
630 * limit by the same amount
632 else if (mz
->usage_in_excess
>= mz_node
->usage_in_excess
)
637 mctz
->rb_rightmost
= &mz
->tree_node
;
639 rb_link_node(&mz
->tree_node
, parent
, p
);
640 rb_insert_color(&mz
->tree_node
, &mctz
->rb_root
);
644 static void __mem_cgroup_remove_exceeded(struct mem_cgroup_per_node
*mz
,
645 struct mem_cgroup_tree_per_node
*mctz
)
650 if (&mz
->tree_node
== mctz
->rb_rightmost
)
651 mctz
->rb_rightmost
= rb_prev(&mz
->tree_node
);
653 rb_erase(&mz
->tree_node
, &mctz
->rb_root
);
657 static void mem_cgroup_remove_exceeded(struct mem_cgroup_per_node
*mz
,
658 struct mem_cgroup_tree_per_node
*mctz
)
662 spin_lock_irqsave(&mctz
->lock
, flags
);
663 __mem_cgroup_remove_exceeded(mz
, mctz
);
664 spin_unlock_irqrestore(&mctz
->lock
, flags
);
667 static unsigned long soft_limit_excess(struct mem_cgroup
*memcg
)
669 unsigned long nr_pages
= page_counter_read(&memcg
->memory
);
670 unsigned long soft_limit
= READ_ONCE(memcg
->soft_limit
);
671 unsigned long excess
= 0;
673 if (nr_pages
> soft_limit
)
674 excess
= nr_pages
- soft_limit
;
679 static void mem_cgroup_update_tree(struct mem_cgroup
*memcg
, struct page
*page
)
681 unsigned long excess
;
682 struct mem_cgroup_per_node
*mz
;
683 struct mem_cgroup_tree_per_node
*mctz
;
685 mctz
= soft_limit_tree_from_page(page
);
689 * Necessary to update all ancestors when hierarchy is used.
690 * because their event counter is not touched.
692 for (; memcg
; memcg
= parent_mem_cgroup(memcg
)) {
693 mz
= mem_cgroup_page_nodeinfo(memcg
, page
);
694 excess
= soft_limit_excess(memcg
);
696 * We have to update the tree if mz is on RB-tree or
697 * mem is over its softlimit.
699 if (excess
|| mz
->on_tree
) {
702 spin_lock_irqsave(&mctz
->lock
, flags
);
703 /* if on-tree, remove it */
705 __mem_cgroup_remove_exceeded(mz
, mctz
);
707 * Insert again. mz->usage_in_excess will be updated.
708 * If excess is 0, no tree ops.
710 __mem_cgroup_insert_exceeded(mz
, mctz
, excess
);
711 spin_unlock_irqrestore(&mctz
->lock
, flags
);
716 static void mem_cgroup_remove_from_trees(struct mem_cgroup
*memcg
)
718 struct mem_cgroup_tree_per_node
*mctz
;
719 struct mem_cgroup_per_node
*mz
;
723 mz
= mem_cgroup_nodeinfo(memcg
, nid
);
724 mctz
= soft_limit_tree_node(nid
);
726 mem_cgroup_remove_exceeded(mz
, mctz
);
730 static struct mem_cgroup_per_node
*
731 __mem_cgroup_largest_soft_limit_node(struct mem_cgroup_tree_per_node
*mctz
)
733 struct mem_cgroup_per_node
*mz
;
737 if (!mctz
->rb_rightmost
)
738 goto done
; /* Nothing to reclaim from */
740 mz
= rb_entry(mctz
->rb_rightmost
,
741 struct mem_cgroup_per_node
, tree_node
);
743 * Remove the node now but someone else can add it back,
744 * we will to add it back at the end of reclaim to its correct
745 * position in the tree.
747 __mem_cgroup_remove_exceeded(mz
, mctz
);
748 if (!soft_limit_excess(mz
->memcg
) ||
749 !css_tryget(&mz
->memcg
->css
))
755 static struct mem_cgroup_per_node
*
756 mem_cgroup_largest_soft_limit_node(struct mem_cgroup_tree_per_node
*mctz
)
758 struct mem_cgroup_per_node
*mz
;
760 spin_lock_irq(&mctz
->lock
);
761 mz
= __mem_cgroup_largest_soft_limit_node(mctz
);
762 spin_unlock_irq(&mctz
->lock
);
767 * __mod_memcg_state - update cgroup memory statistics
768 * @memcg: the memory cgroup
769 * @idx: the stat item - can be enum memcg_stat_item or enum node_stat_item
770 * @val: delta to add to the counter, can be negative
772 void __mod_memcg_state(struct mem_cgroup
*memcg
, int idx
, int val
)
774 long x
, threshold
= MEMCG_CHARGE_BATCH
;
776 if (mem_cgroup_disabled())
779 if (memcg_stat_item_in_bytes(idx
))
780 threshold
<<= PAGE_SHIFT
;
782 x
= val
+ __this_cpu_read(memcg
->vmstats_percpu
->stat
[idx
]);
783 if (unlikely(abs(x
) > threshold
)) {
784 struct mem_cgroup
*mi
;
787 * Batch local counters to keep them in sync with
788 * the hierarchical ones.
790 __this_cpu_add(memcg
->vmstats_local
->stat
[idx
], x
);
791 for (mi
= memcg
; mi
; mi
= parent_mem_cgroup(mi
))
792 atomic_long_add(x
, &mi
->vmstats
[idx
]);
795 __this_cpu_write(memcg
->vmstats_percpu
->stat
[idx
], x
);
798 static struct mem_cgroup_per_node
*
799 parent_nodeinfo(struct mem_cgroup_per_node
*pn
, int nid
)
801 struct mem_cgroup
*parent
;
803 parent
= parent_mem_cgroup(pn
->memcg
);
806 return mem_cgroup_nodeinfo(parent
, nid
);
809 void __mod_memcg_lruvec_state(struct lruvec
*lruvec
, enum node_stat_item idx
,
812 struct mem_cgroup_per_node
*pn
;
813 struct mem_cgroup
*memcg
;
814 long x
, threshold
= MEMCG_CHARGE_BATCH
;
816 pn
= container_of(lruvec
, struct mem_cgroup_per_node
, lruvec
);
820 __mod_memcg_state(memcg
, idx
, val
);
823 __this_cpu_add(pn
->lruvec_stat_local
->count
[idx
], val
);
825 if (vmstat_item_in_bytes(idx
))
826 threshold
<<= PAGE_SHIFT
;
828 x
= val
+ __this_cpu_read(pn
->lruvec_stat_cpu
->count
[idx
]);
829 if (unlikely(abs(x
) > threshold
)) {
830 pg_data_t
*pgdat
= lruvec_pgdat(lruvec
);
831 struct mem_cgroup_per_node
*pi
;
833 for (pi
= pn
; pi
; pi
= parent_nodeinfo(pi
, pgdat
->node_id
))
834 atomic_long_add(x
, &pi
->lruvec_stat
[idx
]);
837 __this_cpu_write(pn
->lruvec_stat_cpu
->count
[idx
], x
);
841 * __mod_lruvec_state - update lruvec memory statistics
842 * @lruvec: the lruvec
843 * @idx: the stat item
844 * @val: delta to add to the counter, can be negative
846 * The lruvec is the intersection of the NUMA node and a cgroup. This
847 * function updates the all three counters that are affected by a
848 * change of state at this level: per-node, per-cgroup, per-lruvec.
850 void __mod_lruvec_state(struct lruvec
*lruvec
, enum node_stat_item idx
,
854 __mod_node_page_state(lruvec_pgdat(lruvec
), idx
, val
);
856 /* Update memcg and lruvec */
857 if (!mem_cgroup_disabled())
858 __mod_memcg_lruvec_state(lruvec
, idx
, val
);
861 void __mod_lruvec_slab_state(void *p
, enum node_stat_item idx
, int val
)
863 pg_data_t
*pgdat
= page_pgdat(virt_to_page(p
));
864 struct mem_cgroup
*memcg
;
865 struct lruvec
*lruvec
;
868 memcg
= mem_cgroup_from_obj(p
);
870 /* Untracked pages have no memcg, no lruvec. Update only the node */
871 if (!memcg
|| memcg
== root_mem_cgroup
) {
872 __mod_node_page_state(pgdat
, idx
, val
);
874 lruvec
= mem_cgroup_lruvec(memcg
, pgdat
);
875 __mod_lruvec_state(lruvec
, idx
, val
);
880 void mod_memcg_obj_state(void *p
, int idx
, int val
)
882 struct mem_cgroup
*memcg
;
885 memcg
= mem_cgroup_from_obj(p
);
887 mod_memcg_state(memcg
, idx
, val
);
892 * __count_memcg_events - account VM events in a cgroup
893 * @memcg: the memory cgroup
894 * @idx: the event item
895 * @count: the number of events that occured
897 void __count_memcg_events(struct mem_cgroup
*memcg
, enum vm_event_item idx
,
902 if (mem_cgroup_disabled())
905 x
= count
+ __this_cpu_read(memcg
->vmstats_percpu
->events
[idx
]);
906 if (unlikely(x
> MEMCG_CHARGE_BATCH
)) {
907 struct mem_cgroup
*mi
;
910 * Batch local counters to keep them in sync with
911 * the hierarchical ones.
913 __this_cpu_add(memcg
->vmstats_local
->events
[idx
], x
);
914 for (mi
= memcg
; mi
; mi
= parent_mem_cgroup(mi
))
915 atomic_long_add(x
, &mi
->vmevents
[idx
]);
918 __this_cpu_write(memcg
->vmstats_percpu
->events
[idx
], x
);
921 static unsigned long memcg_events(struct mem_cgroup
*memcg
, int event
)
923 return atomic_long_read(&memcg
->vmevents
[event
]);
926 static unsigned long memcg_events_local(struct mem_cgroup
*memcg
, int event
)
931 for_each_possible_cpu(cpu
)
932 x
+= per_cpu(memcg
->vmstats_local
->events
[event
], cpu
);
936 static void mem_cgroup_charge_statistics(struct mem_cgroup
*memcg
,
940 /* pagein of a big page is an event. So, ignore page size */
942 __count_memcg_events(memcg
, PGPGIN
, 1);
944 __count_memcg_events(memcg
, PGPGOUT
, 1);
945 nr_pages
= -nr_pages
; /* for event */
948 __this_cpu_add(memcg
->vmstats_percpu
->nr_page_events
, nr_pages
);
951 static bool mem_cgroup_event_ratelimit(struct mem_cgroup
*memcg
,
952 enum mem_cgroup_events_target target
)
954 unsigned long val
, next
;
956 val
= __this_cpu_read(memcg
->vmstats_percpu
->nr_page_events
);
957 next
= __this_cpu_read(memcg
->vmstats_percpu
->targets
[target
]);
958 /* from time_after() in jiffies.h */
959 if ((long)(next
- val
) < 0) {
961 case MEM_CGROUP_TARGET_THRESH
:
962 next
= val
+ THRESHOLDS_EVENTS_TARGET
;
964 case MEM_CGROUP_TARGET_SOFTLIMIT
:
965 next
= val
+ SOFTLIMIT_EVENTS_TARGET
;
970 __this_cpu_write(memcg
->vmstats_percpu
->targets
[target
], next
);
977 * Check events in order.
980 static void memcg_check_events(struct mem_cgroup
*memcg
, struct page
*page
)
982 /* threshold event is triggered in finer grain than soft limit */
983 if (unlikely(mem_cgroup_event_ratelimit(memcg
,
984 MEM_CGROUP_TARGET_THRESH
))) {
987 do_softlimit
= mem_cgroup_event_ratelimit(memcg
,
988 MEM_CGROUP_TARGET_SOFTLIMIT
);
989 mem_cgroup_threshold(memcg
);
990 if (unlikely(do_softlimit
))
991 mem_cgroup_update_tree(memcg
, page
);
995 struct mem_cgroup
*mem_cgroup_from_task(struct task_struct
*p
)
998 * mm_update_next_owner() may clear mm->owner to NULL
999 * if it races with swapoff, page migration, etc.
1000 * So this can be called with p == NULL.
1005 return mem_cgroup_from_css(task_css(p
, memory_cgrp_id
));
1007 EXPORT_SYMBOL(mem_cgroup_from_task
);
1010 * get_mem_cgroup_from_mm: Obtain a reference on given mm_struct's memcg.
1011 * @mm: mm from which memcg should be extracted. It can be NULL.
1013 * Obtain a reference on mm->memcg and returns it if successful. Otherwise
1014 * root_mem_cgroup is returned. However if mem_cgroup is disabled, NULL is
1017 struct mem_cgroup
*get_mem_cgroup_from_mm(struct mm_struct
*mm
)
1019 struct mem_cgroup
*memcg
;
1021 if (mem_cgroup_disabled())
1027 * Page cache insertions can happen withou an
1028 * actual mm context, e.g. during disk probing
1029 * on boot, loopback IO, acct() writes etc.
1032 memcg
= root_mem_cgroup
;
1034 memcg
= mem_cgroup_from_task(rcu_dereference(mm
->owner
));
1035 if (unlikely(!memcg
))
1036 memcg
= root_mem_cgroup
;
1038 } while (!css_tryget(&memcg
->css
));
1042 EXPORT_SYMBOL(get_mem_cgroup_from_mm
);
1045 * get_mem_cgroup_from_page: Obtain a reference on given page's memcg.
1046 * @page: page from which memcg should be extracted.
1048 * Obtain a reference on page->memcg and returns it if successful. Otherwise
1049 * root_mem_cgroup is returned.
1051 struct mem_cgroup
*get_mem_cgroup_from_page(struct page
*page
)
1053 struct mem_cgroup
*memcg
= page
->mem_cgroup
;
1055 if (mem_cgroup_disabled())
1059 /* Page should not get uncharged and freed memcg under us. */
1060 if (!memcg
|| WARN_ON_ONCE(!css_tryget(&memcg
->css
)))
1061 memcg
= root_mem_cgroup
;
1065 EXPORT_SYMBOL(get_mem_cgroup_from_page
);
1067 static __always_inline
struct mem_cgroup
*active_memcg(void)
1070 return this_cpu_read(int_active_memcg
);
1072 return current
->active_memcg
;
1075 static __always_inline
struct mem_cgroup
*get_active_memcg(void)
1077 struct mem_cgroup
*memcg
;
1080 memcg
= active_memcg();
1082 /* current->active_memcg must hold a ref. */
1083 if (WARN_ON_ONCE(!css_tryget(&memcg
->css
)))
1084 memcg
= root_mem_cgroup
;
1086 memcg
= current
->active_memcg
;
1093 static __always_inline
bool memcg_kmem_bypass(void)
1095 /* Allow remote memcg charging from any context. */
1096 if (unlikely(active_memcg()))
1099 /* Memcg to charge can't be determined. */
1100 if (in_interrupt() || !current
->mm
|| (current
->flags
& PF_KTHREAD
))
1107 * If active memcg is set, do not fallback to current->mm->memcg.
1109 static __always_inline
struct mem_cgroup
*get_mem_cgroup_from_current(void)
1111 if (memcg_kmem_bypass())
1114 if (unlikely(active_memcg()))
1115 return get_active_memcg();
1117 return get_mem_cgroup_from_mm(current
->mm
);
1121 * mem_cgroup_iter - iterate over memory cgroup hierarchy
1122 * @root: hierarchy root
1123 * @prev: previously returned memcg, NULL on first invocation
1124 * @reclaim: cookie for shared reclaim walks, NULL for full walks
1126 * Returns references to children of the hierarchy below @root, or
1127 * @root itself, or %NULL after a full round-trip.
1129 * Caller must pass the return value in @prev on subsequent
1130 * invocations for reference counting, or use mem_cgroup_iter_break()
1131 * to cancel a hierarchy walk before the round-trip is complete.
1133 * Reclaimers can specify a node in @reclaim to divide up the memcgs
1134 * in the hierarchy among all concurrent reclaimers operating on the
1137 struct mem_cgroup
*mem_cgroup_iter(struct mem_cgroup
*root
,
1138 struct mem_cgroup
*prev
,
1139 struct mem_cgroup_reclaim_cookie
*reclaim
)
1141 struct mem_cgroup_reclaim_iter
*iter
;
1142 struct cgroup_subsys_state
*css
= NULL
;
1143 struct mem_cgroup
*memcg
= NULL
;
1144 struct mem_cgroup
*pos
= NULL
;
1146 if (mem_cgroup_disabled())
1150 root
= root_mem_cgroup
;
1152 if (prev
&& !reclaim
)
1155 if (!root
->use_hierarchy
&& root
!= root_mem_cgroup
) {
1164 struct mem_cgroup_per_node
*mz
;
1166 mz
= mem_cgroup_nodeinfo(root
, reclaim
->pgdat
->node_id
);
1169 if (prev
&& reclaim
->generation
!= iter
->generation
)
1173 pos
= READ_ONCE(iter
->position
);
1174 if (!pos
|| css_tryget(&pos
->css
))
1177 * css reference reached zero, so iter->position will
1178 * be cleared by ->css_released. However, we should not
1179 * rely on this happening soon, because ->css_released
1180 * is called from a work queue, and by busy-waiting we
1181 * might block it. So we clear iter->position right
1184 (void)cmpxchg(&iter
->position
, pos
, NULL
);
1192 css
= css_next_descendant_pre(css
, &root
->css
);
1195 * Reclaimers share the hierarchy walk, and a
1196 * new one might jump in right at the end of
1197 * the hierarchy - make sure they see at least
1198 * one group and restart from the beginning.
1206 * Verify the css and acquire a reference. The root
1207 * is provided by the caller, so we know it's alive
1208 * and kicking, and don't take an extra reference.
1210 memcg
= mem_cgroup_from_css(css
);
1212 if (css
== &root
->css
)
1215 if (css_tryget(css
))
1223 * The position could have already been updated by a competing
1224 * thread, so check that the value hasn't changed since we read
1225 * it to avoid reclaiming from the same cgroup twice.
1227 (void)cmpxchg(&iter
->position
, pos
, memcg
);
1235 reclaim
->generation
= iter
->generation
;
1241 if (prev
&& prev
!= root
)
1242 css_put(&prev
->css
);
1248 * mem_cgroup_iter_break - abort a hierarchy walk prematurely
1249 * @root: hierarchy root
1250 * @prev: last visited hierarchy member as returned by mem_cgroup_iter()
1252 void mem_cgroup_iter_break(struct mem_cgroup
*root
,
1253 struct mem_cgroup
*prev
)
1256 root
= root_mem_cgroup
;
1257 if (prev
&& prev
!= root
)
1258 css_put(&prev
->css
);
1261 static void __invalidate_reclaim_iterators(struct mem_cgroup
*from
,
1262 struct mem_cgroup
*dead_memcg
)
1264 struct mem_cgroup_reclaim_iter
*iter
;
1265 struct mem_cgroup_per_node
*mz
;
1268 for_each_node(nid
) {
1269 mz
= mem_cgroup_nodeinfo(from
, nid
);
1271 cmpxchg(&iter
->position
, dead_memcg
, NULL
);
1275 static void invalidate_reclaim_iterators(struct mem_cgroup
*dead_memcg
)
1277 struct mem_cgroup
*memcg
= dead_memcg
;
1278 struct mem_cgroup
*last
;
1281 __invalidate_reclaim_iterators(memcg
, dead_memcg
);
1283 } while ((memcg
= parent_mem_cgroup(memcg
)));
1286 * When cgruop1 non-hierarchy mode is used,
1287 * parent_mem_cgroup() does not walk all the way up to the
1288 * cgroup root (root_mem_cgroup). So we have to handle
1289 * dead_memcg from cgroup root separately.
1291 if (last
!= root_mem_cgroup
)
1292 __invalidate_reclaim_iterators(root_mem_cgroup
,
1297 * mem_cgroup_scan_tasks - iterate over tasks of a memory cgroup hierarchy
1298 * @memcg: hierarchy root
1299 * @fn: function to call for each task
1300 * @arg: argument passed to @fn
1302 * This function iterates over tasks attached to @memcg or to any of its
1303 * descendants and calls @fn for each task. If @fn returns a non-zero
1304 * value, the function breaks the iteration loop and returns the value.
1305 * Otherwise, it will iterate over all tasks and return 0.
1307 * This function must not be called for the root memory cgroup.
1309 int mem_cgroup_scan_tasks(struct mem_cgroup
*memcg
,
1310 int (*fn
)(struct task_struct
*, void *), void *arg
)
1312 struct mem_cgroup
*iter
;
1315 BUG_ON(memcg
== root_mem_cgroup
);
1317 for_each_mem_cgroup_tree(iter
, memcg
) {
1318 struct css_task_iter it
;
1319 struct task_struct
*task
;
1321 css_task_iter_start(&iter
->css
, CSS_TASK_ITER_PROCS
, &it
);
1322 while (!ret
&& (task
= css_task_iter_next(&it
)))
1323 ret
= fn(task
, arg
);
1324 css_task_iter_end(&it
);
1326 mem_cgroup_iter_break(memcg
, iter
);
1334 * mem_cgroup_page_lruvec - return lruvec for isolating/putting an LRU page
1336 * @pgdat: pgdat of the page
1338 * This function relies on page->mem_cgroup being stable - see the
1339 * access rules in commit_charge().
1341 struct lruvec
*mem_cgroup_page_lruvec(struct page
*page
, struct pglist_data
*pgdat
)
1343 struct mem_cgroup_per_node
*mz
;
1344 struct mem_cgroup
*memcg
;
1345 struct lruvec
*lruvec
;
1347 if (mem_cgroup_disabled()) {
1348 lruvec
= &pgdat
->__lruvec
;
1352 memcg
= page
->mem_cgroup
;
1354 * Swapcache readahead pages are added to the LRU - and
1355 * possibly migrated - before they are charged.
1358 memcg
= root_mem_cgroup
;
1360 mz
= mem_cgroup_page_nodeinfo(memcg
, page
);
1361 lruvec
= &mz
->lruvec
;
1364 * Since a node can be onlined after the mem_cgroup was created,
1365 * we have to be prepared to initialize lruvec->zone here;
1366 * and if offlined then reonlined, we need to reinitialize it.
1368 if (unlikely(lruvec
->pgdat
!= pgdat
))
1369 lruvec
->pgdat
= pgdat
;
1374 * mem_cgroup_update_lru_size - account for adding or removing an lru page
1375 * @lruvec: mem_cgroup per zone lru vector
1376 * @lru: index of lru list the page is sitting on
1377 * @zid: zone id of the accounted pages
1378 * @nr_pages: positive when adding or negative when removing
1380 * This function must be called under lru_lock, just before a page is added
1381 * to or just after a page is removed from an lru list (that ordering being
1382 * so as to allow it to check that lru_size 0 is consistent with list_empty).
1384 void mem_cgroup_update_lru_size(struct lruvec
*lruvec
, enum lru_list lru
,
1385 int zid
, int nr_pages
)
1387 struct mem_cgroup_per_node
*mz
;
1388 unsigned long *lru_size
;
1391 if (mem_cgroup_disabled())
1394 mz
= container_of(lruvec
, struct mem_cgroup_per_node
, lruvec
);
1395 lru_size
= &mz
->lru_zone_size
[zid
][lru
];
1398 *lru_size
+= nr_pages
;
1401 if (WARN_ONCE(size
< 0,
1402 "%s(%p, %d, %d): lru_size %ld\n",
1403 __func__
, lruvec
, lru
, nr_pages
, size
)) {
1409 *lru_size
+= nr_pages
;
1413 * mem_cgroup_margin - calculate chargeable space of a memory cgroup
1414 * @memcg: the memory cgroup
1416 * Returns the maximum amount of memory @mem can be charged with, in
1419 static unsigned long mem_cgroup_margin(struct mem_cgroup
*memcg
)
1421 unsigned long margin
= 0;
1422 unsigned long count
;
1423 unsigned long limit
;
1425 count
= page_counter_read(&memcg
->memory
);
1426 limit
= READ_ONCE(memcg
->memory
.max
);
1428 margin
= limit
- count
;
1430 if (do_memsw_account()) {
1431 count
= page_counter_read(&memcg
->memsw
);
1432 limit
= READ_ONCE(memcg
->memsw
.max
);
1434 margin
= min(margin
, limit
- count
);
1443 * A routine for checking "mem" is under move_account() or not.
1445 * Checking a cgroup is mc.from or mc.to or under hierarchy of
1446 * moving cgroups. This is for waiting at high-memory pressure
1449 static bool mem_cgroup_under_move(struct mem_cgroup
*memcg
)
1451 struct mem_cgroup
*from
;
1452 struct mem_cgroup
*to
;
1455 * Unlike task_move routines, we access mc.to, mc.from not under
1456 * mutual exclusion by cgroup_mutex. Here, we take spinlock instead.
1458 spin_lock(&mc
.lock
);
1464 ret
= mem_cgroup_is_descendant(from
, memcg
) ||
1465 mem_cgroup_is_descendant(to
, memcg
);
1467 spin_unlock(&mc
.lock
);
1471 static bool mem_cgroup_wait_acct_move(struct mem_cgroup
*memcg
)
1473 if (mc
.moving_task
&& current
!= mc
.moving_task
) {
1474 if (mem_cgroup_under_move(memcg
)) {
1476 prepare_to_wait(&mc
.waitq
, &wait
, TASK_INTERRUPTIBLE
);
1477 /* moving charge context might have finished. */
1480 finish_wait(&mc
.waitq
, &wait
);
1487 struct memory_stat
{
1493 static struct memory_stat memory_stats
[] = {
1494 { "anon", PAGE_SIZE
, NR_ANON_MAPPED
},
1495 { "file", PAGE_SIZE
, NR_FILE_PAGES
},
1496 { "kernel_stack", 1024, NR_KERNEL_STACK_KB
},
1497 { "percpu", 1, MEMCG_PERCPU_B
},
1498 { "sock", PAGE_SIZE
, MEMCG_SOCK
},
1499 { "shmem", PAGE_SIZE
, NR_SHMEM
},
1500 { "file_mapped", PAGE_SIZE
, NR_FILE_MAPPED
},
1501 { "file_dirty", PAGE_SIZE
, NR_FILE_DIRTY
},
1502 { "file_writeback", PAGE_SIZE
, NR_WRITEBACK
},
1503 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
1505 * The ratio will be initialized in memory_stats_init(). Because
1506 * on some architectures, the macro of HPAGE_PMD_SIZE is not
1507 * constant(e.g. powerpc).
1509 { "anon_thp", 0, NR_ANON_THPS
},
1511 { "inactive_anon", PAGE_SIZE
, NR_INACTIVE_ANON
},
1512 { "active_anon", PAGE_SIZE
, NR_ACTIVE_ANON
},
1513 { "inactive_file", PAGE_SIZE
, NR_INACTIVE_FILE
},
1514 { "active_file", PAGE_SIZE
, NR_ACTIVE_FILE
},
1515 { "unevictable", PAGE_SIZE
, NR_UNEVICTABLE
},
1518 * Note: The slab_reclaimable and slab_unreclaimable must be
1519 * together and slab_reclaimable must be in front.
1521 { "slab_reclaimable", 1, NR_SLAB_RECLAIMABLE_B
},
1522 { "slab_unreclaimable", 1, NR_SLAB_UNRECLAIMABLE_B
},
1524 /* The memory events */
1525 { "workingset_refault_anon", 1, WORKINGSET_REFAULT_ANON
},
1526 { "workingset_refault_file", 1, WORKINGSET_REFAULT_FILE
},
1527 { "workingset_activate_anon", 1, WORKINGSET_ACTIVATE_ANON
},
1528 { "workingset_activate_file", 1, WORKINGSET_ACTIVATE_FILE
},
1529 { "workingset_restore_anon", 1, WORKINGSET_RESTORE_ANON
},
1530 { "workingset_restore_file", 1, WORKINGSET_RESTORE_FILE
},
1531 { "workingset_nodereclaim", 1, WORKINGSET_NODERECLAIM
},
1534 static int __init
memory_stats_init(void)
1538 for (i
= 0; i
< ARRAY_SIZE(memory_stats
); i
++) {
1539 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
1540 if (memory_stats
[i
].idx
== NR_ANON_THPS
)
1541 memory_stats
[i
].ratio
= HPAGE_PMD_SIZE
;
1543 VM_BUG_ON(!memory_stats
[i
].ratio
);
1544 VM_BUG_ON(memory_stats
[i
].idx
>= MEMCG_NR_STAT
);
1549 pure_initcall(memory_stats_init
);
1551 static char *memory_stat_format(struct mem_cgroup
*memcg
)
1556 seq_buf_init(&s
, kmalloc(PAGE_SIZE
, GFP_KERNEL
), PAGE_SIZE
);
1561 * Provide statistics on the state of the memory subsystem as
1562 * well as cumulative event counters that show past behavior.
1564 * This list is ordered following a combination of these gradients:
1565 * 1) generic big picture -> specifics and details
1566 * 2) reflecting userspace activity -> reflecting kernel heuristics
1568 * Current memory state:
1571 for (i
= 0; i
< ARRAY_SIZE(memory_stats
); i
++) {
1574 size
= memcg_page_state(memcg
, memory_stats
[i
].idx
);
1575 size
*= memory_stats
[i
].ratio
;
1576 seq_buf_printf(&s
, "%s %llu\n", memory_stats
[i
].name
, size
);
1578 if (unlikely(memory_stats
[i
].idx
== NR_SLAB_UNRECLAIMABLE_B
)) {
1579 size
= memcg_page_state(memcg
, NR_SLAB_RECLAIMABLE_B
) +
1580 memcg_page_state(memcg
, NR_SLAB_UNRECLAIMABLE_B
);
1581 seq_buf_printf(&s
, "slab %llu\n", size
);
1585 /* Accumulated memory events */
1587 seq_buf_printf(&s
, "%s %lu\n", vm_event_name(PGFAULT
),
1588 memcg_events(memcg
, PGFAULT
));
1589 seq_buf_printf(&s
, "%s %lu\n", vm_event_name(PGMAJFAULT
),
1590 memcg_events(memcg
, PGMAJFAULT
));
1591 seq_buf_printf(&s
, "%s %lu\n", vm_event_name(PGREFILL
),
1592 memcg_events(memcg
, PGREFILL
));
1593 seq_buf_printf(&s
, "pgscan %lu\n",
1594 memcg_events(memcg
, PGSCAN_KSWAPD
) +
1595 memcg_events(memcg
, PGSCAN_DIRECT
));
1596 seq_buf_printf(&s
, "pgsteal %lu\n",
1597 memcg_events(memcg
, PGSTEAL_KSWAPD
) +
1598 memcg_events(memcg
, PGSTEAL_DIRECT
));
1599 seq_buf_printf(&s
, "%s %lu\n", vm_event_name(PGACTIVATE
),
1600 memcg_events(memcg
, PGACTIVATE
));
1601 seq_buf_printf(&s
, "%s %lu\n", vm_event_name(PGDEACTIVATE
),
1602 memcg_events(memcg
, PGDEACTIVATE
));
1603 seq_buf_printf(&s
, "%s %lu\n", vm_event_name(PGLAZYFREE
),
1604 memcg_events(memcg
, PGLAZYFREE
));
1605 seq_buf_printf(&s
, "%s %lu\n", vm_event_name(PGLAZYFREED
),
1606 memcg_events(memcg
, PGLAZYFREED
));
1608 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
1609 seq_buf_printf(&s
, "%s %lu\n", vm_event_name(THP_FAULT_ALLOC
),
1610 memcg_events(memcg
, THP_FAULT_ALLOC
));
1611 seq_buf_printf(&s
, "%s %lu\n", vm_event_name(THP_COLLAPSE_ALLOC
),
1612 memcg_events(memcg
, THP_COLLAPSE_ALLOC
));
1613 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
1615 /* The above should easily fit into one page */
1616 WARN_ON_ONCE(seq_buf_has_overflowed(&s
));
1621 #define K(x) ((x) << (PAGE_SHIFT-10))
1623 * mem_cgroup_print_oom_context: Print OOM information relevant to
1624 * memory controller.
1625 * @memcg: The memory cgroup that went over limit
1626 * @p: Task that is going to be killed
1628 * NOTE: @memcg and @p's mem_cgroup can be different when hierarchy is
1631 void mem_cgroup_print_oom_context(struct mem_cgroup
*memcg
, struct task_struct
*p
)
1636 pr_cont(",oom_memcg=");
1637 pr_cont_cgroup_path(memcg
->css
.cgroup
);
1639 pr_cont(",global_oom");
1641 pr_cont(",task_memcg=");
1642 pr_cont_cgroup_path(task_cgroup(p
, memory_cgrp_id
));
1648 * mem_cgroup_print_oom_meminfo: Print OOM memory information relevant to
1649 * memory controller.
1650 * @memcg: The memory cgroup that went over limit
1652 void mem_cgroup_print_oom_meminfo(struct mem_cgroup
*memcg
)
1656 pr_info("memory: usage %llukB, limit %llukB, failcnt %lu\n",
1657 K((u64
)page_counter_read(&memcg
->memory
)),
1658 K((u64
)READ_ONCE(memcg
->memory
.max
)), memcg
->memory
.failcnt
);
1659 if (cgroup_subsys_on_dfl(memory_cgrp_subsys
))
1660 pr_info("swap: usage %llukB, limit %llukB, failcnt %lu\n",
1661 K((u64
)page_counter_read(&memcg
->swap
)),
1662 K((u64
)READ_ONCE(memcg
->swap
.max
)), memcg
->swap
.failcnt
);
1664 pr_info("memory+swap: usage %llukB, limit %llukB, failcnt %lu\n",
1665 K((u64
)page_counter_read(&memcg
->memsw
)),
1666 K((u64
)memcg
->memsw
.max
), memcg
->memsw
.failcnt
);
1667 pr_info("kmem: usage %llukB, limit %llukB, failcnt %lu\n",
1668 K((u64
)page_counter_read(&memcg
->kmem
)),
1669 K((u64
)memcg
->kmem
.max
), memcg
->kmem
.failcnt
);
1672 pr_info("Memory cgroup stats for ");
1673 pr_cont_cgroup_path(memcg
->css
.cgroup
);
1675 buf
= memory_stat_format(memcg
);
1683 * Return the memory (and swap, if configured) limit for a memcg.
1685 unsigned long mem_cgroup_get_max(struct mem_cgroup
*memcg
)
1687 unsigned long max
= READ_ONCE(memcg
->memory
.max
);
1689 if (cgroup_subsys_on_dfl(memory_cgrp_subsys
)) {
1690 if (mem_cgroup_swappiness(memcg
))
1691 max
+= min(READ_ONCE(memcg
->swap
.max
),
1692 (unsigned long)total_swap_pages
);
1694 if (mem_cgroup_swappiness(memcg
)) {
1695 /* Calculate swap excess capacity from memsw limit */
1696 unsigned long swap
= READ_ONCE(memcg
->memsw
.max
) - max
;
1698 max
+= min(swap
, (unsigned long)total_swap_pages
);
1704 unsigned long mem_cgroup_size(struct mem_cgroup
*memcg
)
1706 return page_counter_read(&memcg
->memory
);
1709 static bool mem_cgroup_out_of_memory(struct mem_cgroup
*memcg
, gfp_t gfp_mask
,
1712 struct oom_control oc
= {
1716 .gfp_mask
= gfp_mask
,
1721 if (mutex_lock_killable(&oom_lock
))
1724 if (mem_cgroup_margin(memcg
) >= (1 << order
))
1728 * A few threads which were not waiting at mutex_lock_killable() can
1729 * fail to bail out. Therefore, check again after holding oom_lock.
1731 ret
= should_force_charge() || out_of_memory(&oc
);
1734 mutex_unlock(&oom_lock
);
1738 static int mem_cgroup_soft_reclaim(struct mem_cgroup
*root_memcg
,
1741 unsigned long *total_scanned
)
1743 struct mem_cgroup
*victim
= NULL
;
1746 unsigned long excess
;
1747 unsigned long nr_scanned
;
1748 struct mem_cgroup_reclaim_cookie reclaim
= {
1752 excess
= soft_limit_excess(root_memcg
);
1755 victim
= mem_cgroup_iter(root_memcg
, victim
, &reclaim
);
1760 * If we have not been able to reclaim
1761 * anything, it might because there are
1762 * no reclaimable pages under this hierarchy
1767 * We want to do more targeted reclaim.
1768 * excess >> 2 is not to excessive so as to
1769 * reclaim too much, nor too less that we keep
1770 * coming back to reclaim from this cgroup
1772 if (total
>= (excess
>> 2) ||
1773 (loop
> MEM_CGROUP_MAX_RECLAIM_LOOPS
))
1778 total
+= mem_cgroup_shrink_node(victim
, gfp_mask
, false,
1779 pgdat
, &nr_scanned
);
1780 *total_scanned
+= nr_scanned
;
1781 if (!soft_limit_excess(root_memcg
))
1784 mem_cgroup_iter_break(root_memcg
, victim
);
1788 #ifdef CONFIG_LOCKDEP
1789 static struct lockdep_map memcg_oom_lock_dep_map
= {
1790 .name
= "memcg_oom_lock",
1794 static DEFINE_SPINLOCK(memcg_oom_lock
);
1797 * Check OOM-Killer is already running under our hierarchy.
1798 * If someone is running, return false.
1800 static bool mem_cgroup_oom_trylock(struct mem_cgroup
*memcg
)
1802 struct mem_cgroup
*iter
, *failed
= NULL
;
1804 spin_lock(&memcg_oom_lock
);
1806 for_each_mem_cgroup_tree(iter
, memcg
) {
1807 if (iter
->oom_lock
) {
1809 * this subtree of our hierarchy is already locked
1810 * so we cannot give a lock.
1813 mem_cgroup_iter_break(memcg
, iter
);
1816 iter
->oom_lock
= true;
1821 * OK, we failed to lock the whole subtree so we have
1822 * to clean up what we set up to the failing subtree
1824 for_each_mem_cgroup_tree(iter
, memcg
) {
1825 if (iter
== failed
) {
1826 mem_cgroup_iter_break(memcg
, iter
);
1829 iter
->oom_lock
= false;
1832 mutex_acquire(&memcg_oom_lock_dep_map
, 0, 1, _RET_IP_
);
1834 spin_unlock(&memcg_oom_lock
);
1839 static void mem_cgroup_oom_unlock(struct mem_cgroup
*memcg
)
1841 struct mem_cgroup
*iter
;
1843 spin_lock(&memcg_oom_lock
);
1844 mutex_release(&memcg_oom_lock_dep_map
, _RET_IP_
);
1845 for_each_mem_cgroup_tree(iter
, memcg
)
1846 iter
->oom_lock
= false;
1847 spin_unlock(&memcg_oom_lock
);
1850 static void mem_cgroup_mark_under_oom(struct mem_cgroup
*memcg
)
1852 struct mem_cgroup
*iter
;
1854 spin_lock(&memcg_oom_lock
);
1855 for_each_mem_cgroup_tree(iter
, memcg
)
1857 spin_unlock(&memcg_oom_lock
);
1860 static void mem_cgroup_unmark_under_oom(struct mem_cgroup
*memcg
)
1862 struct mem_cgroup
*iter
;
1865 * Be careful about under_oom underflows becase a child memcg
1866 * could have been added after mem_cgroup_mark_under_oom.
1868 spin_lock(&memcg_oom_lock
);
1869 for_each_mem_cgroup_tree(iter
, memcg
)
1870 if (iter
->under_oom
> 0)
1872 spin_unlock(&memcg_oom_lock
);
1875 static DECLARE_WAIT_QUEUE_HEAD(memcg_oom_waitq
);
1877 struct oom_wait_info
{
1878 struct mem_cgroup
*memcg
;
1879 wait_queue_entry_t wait
;
1882 static int memcg_oom_wake_function(wait_queue_entry_t
*wait
,
1883 unsigned mode
, int sync
, void *arg
)
1885 struct mem_cgroup
*wake_memcg
= (struct mem_cgroup
*)arg
;
1886 struct mem_cgroup
*oom_wait_memcg
;
1887 struct oom_wait_info
*oom_wait_info
;
1889 oom_wait_info
= container_of(wait
, struct oom_wait_info
, wait
);
1890 oom_wait_memcg
= oom_wait_info
->memcg
;
1892 if (!mem_cgroup_is_descendant(wake_memcg
, oom_wait_memcg
) &&
1893 !mem_cgroup_is_descendant(oom_wait_memcg
, wake_memcg
))
1895 return autoremove_wake_function(wait
, mode
, sync
, arg
);
1898 static void memcg_oom_recover(struct mem_cgroup
*memcg
)
1901 * For the following lockless ->under_oom test, the only required
1902 * guarantee is that it must see the state asserted by an OOM when
1903 * this function is called as a result of userland actions
1904 * triggered by the notification of the OOM. This is trivially
1905 * achieved by invoking mem_cgroup_mark_under_oom() before
1906 * triggering notification.
1908 if (memcg
&& memcg
->under_oom
)
1909 __wake_up(&memcg_oom_waitq
, TASK_NORMAL
, 0, memcg
);
1919 static enum oom_status
mem_cgroup_oom(struct mem_cgroup
*memcg
, gfp_t mask
, int order
)
1921 enum oom_status ret
;
1924 if (order
> PAGE_ALLOC_COSTLY_ORDER
)
1927 memcg_memory_event(memcg
, MEMCG_OOM
);
1930 * We are in the middle of the charge context here, so we
1931 * don't want to block when potentially sitting on a callstack
1932 * that holds all kinds of filesystem and mm locks.
1934 * cgroup1 allows disabling the OOM killer and waiting for outside
1935 * handling until the charge can succeed; remember the context and put
1936 * the task to sleep at the end of the page fault when all locks are
1939 * On the other hand, in-kernel OOM killer allows for an async victim
1940 * memory reclaim (oom_reaper) and that means that we are not solely
1941 * relying on the oom victim to make a forward progress and we can
1942 * invoke the oom killer here.
1944 * Please note that mem_cgroup_out_of_memory might fail to find a
1945 * victim and then we have to bail out from the charge path.
1947 if (memcg
->oom_kill_disable
) {
1948 if (!current
->in_user_fault
)
1950 css_get(&memcg
->css
);
1951 current
->memcg_in_oom
= memcg
;
1952 current
->memcg_oom_gfp_mask
= mask
;
1953 current
->memcg_oom_order
= order
;
1958 mem_cgroup_mark_under_oom(memcg
);
1960 locked
= mem_cgroup_oom_trylock(memcg
);
1963 mem_cgroup_oom_notify(memcg
);
1965 mem_cgroup_unmark_under_oom(memcg
);
1966 if (mem_cgroup_out_of_memory(memcg
, mask
, order
))
1972 mem_cgroup_oom_unlock(memcg
);
1978 * mem_cgroup_oom_synchronize - complete memcg OOM handling
1979 * @handle: actually kill/wait or just clean up the OOM state
1981 * This has to be called at the end of a page fault if the memcg OOM
1982 * handler was enabled.
1984 * Memcg supports userspace OOM handling where failed allocations must
1985 * sleep on a waitqueue until the userspace task resolves the
1986 * situation. Sleeping directly in the charge context with all kinds
1987 * of locks held is not a good idea, instead we remember an OOM state
1988 * in the task and mem_cgroup_oom_synchronize() has to be called at
1989 * the end of the page fault to complete the OOM handling.
1991 * Returns %true if an ongoing memcg OOM situation was detected and
1992 * completed, %false otherwise.
1994 bool mem_cgroup_oom_synchronize(bool handle
)
1996 struct mem_cgroup
*memcg
= current
->memcg_in_oom
;
1997 struct oom_wait_info owait
;
2000 /* OOM is global, do not handle */
2007 owait
.memcg
= memcg
;
2008 owait
.wait
.flags
= 0;
2009 owait
.wait
.func
= memcg_oom_wake_function
;
2010 owait
.wait
.private = current
;
2011 INIT_LIST_HEAD(&owait
.wait
.entry
);
2013 prepare_to_wait(&memcg_oom_waitq
, &owait
.wait
, TASK_KILLABLE
);
2014 mem_cgroup_mark_under_oom(memcg
);
2016 locked
= mem_cgroup_oom_trylock(memcg
);
2019 mem_cgroup_oom_notify(memcg
);
2021 if (locked
&& !memcg
->oom_kill_disable
) {
2022 mem_cgroup_unmark_under_oom(memcg
);
2023 finish_wait(&memcg_oom_waitq
, &owait
.wait
);
2024 mem_cgroup_out_of_memory(memcg
, current
->memcg_oom_gfp_mask
,
2025 current
->memcg_oom_order
);
2028 mem_cgroup_unmark_under_oom(memcg
);
2029 finish_wait(&memcg_oom_waitq
, &owait
.wait
);
2033 mem_cgroup_oom_unlock(memcg
);
2035 * There is no guarantee that an OOM-lock contender
2036 * sees the wakeups triggered by the OOM kill
2037 * uncharges. Wake any sleepers explicitely.
2039 memcg_oom_recover(memcg
);
2042 current
->memcg_in_oom
= NULL
;
2043 css_put(&memcg
->css
);
2048 * mem_cgroup_get_oom_group - get a memory cgroup to clean up after OOM
2049 * @victim: task to be killed by the OOM killer
2050 * @oom_domain: memcg in case of memcg OOM, NULL in case of system-wide OOM
2052 * Returns a pointer to a memory cgroup, which has to be cleaned up
2053 * by killing all belonging OOM-killable tasks.
2055 * Caller has to call mem_cgroup_put() on the returned non-NULL memcg.
2057 struct mem_cgroup
*mem_cgroup_get_oom_group(struct task_struct
*victim
,
2058 struct mem_cgroup
*oom_domain
)
2060 struct mem_cgroup
*oom_group
= NULL
;
2061 struct mem_cgroup
*memcg
;
2063 if (!cgroup_subsys_on_dfl(memory_cgrp_subsys
))
2067 oom_domain
= root_mem_cgroup
;
2071 memcg
= mem_cgroup_from_task(victim
);
2072 if (memcg
== root_mem_cgroup
)
2076 * If the victim task has been asynchronously moved to a different
2077 * memory cgroup, we might end up killing tasks outside oom_domain.
2078 * In this case it's better to ignore memory.group.oom.
2080 if (unlikely(!mem_cgroup_is_descendant(memcg
, oom_domain
)))
2084 * Traverse the memory cgroup hierarchy from the victim task's
2085 * cgroup up to the OOMing cgroup (or root) to find the
2086 * highest-level memory cgroup with oom.group set.
2088 for (; memcg
; memcg
= parent_mem_cgroup(memcg
)) {
2089 if (memcg
->oom_group
)
2092 if (memcg
== oom_domain
)
2097 css_get(&oom_group
->css
);
2104 void mem_cgroup_print_oom_group(struct mem_cgroup
*memcg
)
2106 pr_info("Tasks in ");
2107 pr_cont_cgroup_path(memcg
->css
.cgroup
);
2108 pr_cont(" are going to be killed due to memory.oom.group set\n");
2112 * lock_page_memcg - lock a page->mem_cgroup binding
2115 * This function protects unlocked LRU pages from being moved to
2118 * It ensures lifetime of the returned memcg. Caller is responsible
2119 * for the lifetime of the page; __unlock_page_memcg() is available
2120 * when @page might get freed inside the locked section.
2122 struct mem_cgroup
*lock_page_memcg(struct page
*page
)
2124 struct page
*head
= compound_head(page
); /* rmap on tail pages */
2125 struct mem_cgroup
*memcg
;
2126 unsigned long flags
;
2129 * The RCU lock is held throughout the transaction. The fast
2130 * path can get away without acquiring the memcg->move_lock
2131 * because page moving starts with an RCU grace period.
2133 * The RCU lock also protects the memcg from being freed when
2134 * the page state that is going to change is the only thing
2135 * preventing the page itself from being freed. E.g. writeback
2136 * doesn't hold a page reference and relies on PG_writeback to
2137 * keep off truncation, migration and so forth.
2141 if (mem_cgroup_disabled())
2144 memcg
= head
->mem_cgroup
;
2145 if (unlikely(!memcg
))
2148 if (atomic_read(&memcg
->moving_account
) <= 0)
2151 spin_lock_irqsave(&memcg
->move_lock
, flags
);
2152 if (memcg
!= head
->mem_cgroup
) {
2153 spin_unlock_irqrestore(&memcg
->move_lock
, flags
);
2158 * When charge migration first begins, we can have locked and
2159 * unlocked page stat updates happening concurrently. Track
2160 * the task who has the lock for unlock_page_memcg().
2162 memcg
->move_lock_task
= current
;
2163 memcg
->move_lock_flags
= flags
;
2167 EXPORT_SYMBOL(lock_page_memcg
);
2170 * __unlock_page_memcg - unlock and unpin a memcg
2173 * Unlock and unpin a memcg returned by lock_page_memcg().
2175 void __unlock_page_memcg(struct mem_cgroup
*memcg
)
2177 if (memcg
&& memcg
->move_lock_task
== current
) {
2178 unsigned long flags
= memcg
->move_lock_flags
;
2180 memcg
->move_lock_task
= NULL
;
2181 memcg
->move_lock_flags
= 0;
2183 spin_unlock_irqrestore(&memcg
->move_lock
, flags
);
2190 * unlock_page_memcg - unlock a page->mem_cgroup binding
2193 void unlock_page_memcg(struct page
*page
)
2195 struct page
*head
= compound_head(page
);
2197 __unlock_page_memcg(head
->mem_cgroup
);
2199 EXPORT_SYMBOL(unlock_page_memcg
);
2201 struct memcg_stock_pcp
{
2202 struct mem_cgroup
*cached
; /* this never be root cgroup */
2203 unsigned int nr_pages
;
2205 #ifdef CONFIG_MEMCG_KMEM
2206 struct obj_cgroup
*cached_objcg
;
2207 unsigned int nr_bytes
;
2210 struct work_struct work
;
2211 unsigned long flags
;
2212 #define FLUSHING_CACHED_CHARGE 0
2214 static DEFINE_PER_CPU(struct memcg_stock_pcp
, memcg_stock
);
2215 static DEFINE_MUTEX(percpu_charge_mutex
);
2217 #ifdef CONFIG_MEMCG_KMEM
2218 static void drain_obj_stock(struct memcg_stock_pcp
*stock
);
2219 static bool obj_stock_flush_required(struct memcg_stock_pcp
*stock
,
2220 struct mem_cgroup
*root_memcg
);
2223 static inline void drain_obj_stock(struct memcg_stock_pcp
*stock
)
2226 static bool obj_stock_flush_required(struct memcg_stock_pcp
*stock
,
2227 struct mem_cgroup
*root_memcg
)
2234 * consume_stock: Try to consume stocked charge on this cpu.
2235 * @memcg: memcg to consume from.
2236 * @nr_pages: how many pages to charge.
2238 * The charges will only happen if @memcg matches the current cpu's memcg
2239 * stock, and at least @nr_pages are available in that stock. Failure to
2240 * service an allocation will refill the stock.
2242 * returns true if successful, false otherwise.
2244 static bool consume_stock(struct mem_cgroup
*memcg
, unsigned int nr_pages
)
2246 struct memcg_stock_pcp
*stock
;
2247 unsigned long flags
;
2250 if (nr_pages
> MEMCG_CHARGE_BATCH
)
2253 local_irq_save(flags
);
2255 stock
= this_cpu_ptr(&memcg_stock
);
2256 if (memcg
== stock
->cached
&& stock
->nr_pages
>= nr_pages
) {
2257 stock
->nr_pages
-= nr_pages
;
2261 local_irq_restore(flags
);
2267 * Returns stocks cached in percpu and reset cached information.
2269 static void drain_stock(struct memcg_stock_pcp
*stock
)
2271 struct mem_cgroup
*old
= stock
->cached
;
2276 if (stock
->nr_pages
) {
2277 page_counter_uncharge(&old
->memory
, stock
->nr_pages
);
2278 if (do_memsw_account())
2279 page_counter_uncharge(&old
->memsw
, stock
->nr_pages
);
2280 stock
->nr_pages
= 0;
2284 stock
->cached
= NULL
;
2287 static void drain_local_stock(struct work_struct
*dummy
)
2289 struct memcg_stock_pcp
*stock
;
2290 unsigned long flags
;
2293 * The only protection from memory hotplug vs. drain_stock races is
2294 * that we always operate on local CPU stock here with IRQ disabled
2296 local_irq_save(flags
);
2298 stock
= this_cpu_ptr(&memcg_stock
);
2299 drain_obj_stock(stock
);
2301 clear_bit(FLUSHING_CACHED_CHARGE
, &stock
->flags
);
2303 local_irq_restore(flags
);
2307 * Cache charges(val) to local per_cpu area.
2308 * This will be consumed by consume_stock() function, later.
2310 static void refill_stock(struct mem_cgroup
*memcg
, unsigned int nr_pages
)
2312 struct memcg_stock_pcp
*stock
;
2313 unsigned long flags
;
2315 local_irq_save(flags
);
2317 stock
= this_cpu_ptr(&memcg_stock
);
2318 if (stock
->cached
!= memcg
) { /* reset if necessary */
2320 css_get(&memcg
->css
);
2321 stock
->cached
= memcg
;
2323 stock
->nr_pages
+= nr_pages
;
2325 if (stock
->nr_pages
> MEMCG_CHARGE_BATCH
)
2328 local_irq_restore(flags
);
2332 * Drains all per-CPU charge caches for given root_memcg resp. subtree
2333 * of the hierarchy under it.
2335 static void drain_all_stock(struct mem_cgroup
*root_memcg
)
2339 /* If someone's already draining, avoid adding running more workers. */
2340 if (!mutex_trylock(&percpu_charge_mutex
))
2343 * Notify other cpus that system-wide "drain" is running
2344 * We do not care about races with the cpu hotplug because cpu down
2345 * as well as workers from this path always operate on the local
2346 * per-cpu data. CPU up doesn't touch memcg_stock at all.
2349 for_each_online_cpu(cpu
) {
2350 struct memcg_stock_pcp
*stock
= &per_cpu(memcg_stock
, cpu
);
2351 struct mem_cgroup
*memcg
;
2355 memcg
= stock
->cached
;
2356 if (memcg
&& stock
->nr_pages
&&
2357 mem_cgroup_is_descendant(memcg
, root_memcg
))
2359 if (obj_stock_flush_required(stock
, root_memcg
))
2364 !test_and_set_bit(FLUSHING_CACHED_CHARGE
, &stock
->flags
)) {
2366 drain_local_stock(&stock
->work
);
2368 schedule_work_on(cpu
, &stock
->work
);
2372 mutex_unlock(&percpu_charge_mutex
);
2375 static int memcg_hotplug_cpu_dead(unsigned int cpu
)
2377 struct memcg_stock_pcp
*stock
;
2378 struct mem_cgroup
*memcg
, *mi
;
2380 stock
= &per_cpu(memcg_stock
, cpu
);
2383 for_each_mem_cgroup(memcg
) {
2386 for (i
= 0; i
< MEMCG_NR_STAT
; i
++) {
2390 x
= this_cpu_xchg(memcg
->vmstats_percpu
->stat
[i
], 0);
2392 for (mi
= memcg
; mi
; mi
= parent_mem_cgroup(mi
))
2393 atomic_long_add(x
, &memcg
->vmstats
[i
]);
2395 if (i
>= NR_VM_NODE_STAT_ITEMS
)
2398 for_each_node(nid
) {
2399 struct mem_cgroup_per_node
*pn
;
2401 pn
= mem_cgroup_nodeinfo(memcg
, nid
);
2402 x
= this_cpu_xchg(pn
->lruvec_stat_cpu
->count
[i
], 0);
2405 atomic_long_add(x
, &pn
->lruvec_stat
[i
]);
2406 } while ((pn
= parent_nodeinfo(pn
, nid
)));
2410 for (i
= 0; i
< NR_VM_EVENT_ITEMS
; i
++) {
2413 x
= this_cpu_xchg(memcg
->vmstats_percpu
->events
[i
], 0);
2415 for (mi
= memcg
; mi
; mi
= parent_mem_cgroup(mi
))
2416 atomic_long_add(x
, &memcg
->vmevents
[i
]);
2423 static unsigned long reclaim_high(struct mem_cgroup
*memcg
,
2424 unsigned int nr_pages
,
2427 unsigned long nr_reclaimed
= 0;
2430 unsigned long pflags
;
2432 if (page_counter_read(&memcg
->memory
) <=
2433 READ_ONCE(memcg
->memory
.high
))
2436 memcg_memory_event(memcg
, MEMCG_HIGH
);
2438 psi_memstall_enter(&pflags
);
2439 nr_reclaimed
+= try_to_free_mem_cgroup_pages(memcg
, nr_pages
,
2441 psi_memstall_leave(&pflags
);
2442 } while ((memcg
= parent_mem_cgroup(memcg
)) &&
2443 !mem_cgroup_is_root(memcg
));
2445 return nr_reclaimed
;
2448 static void high_work_func(struct work_struct
*work
)
2450 struct mem_cgroup
*memcg
;
2452 memcg
= container_of(work
, struct mem_cgroup
, high_work
);
2453 reclaim_high(memcg
, MEMCG_CHARGE_BATCH
, GFP_KERNEL
);
2457 * Clamp the maximum sleep time per allocation batch to 2 seconds. This is
2458 * enough to still cause a significant slowdown in most cases, while still
2459 * allowing diagnostics and tracing to proceed without becoming stuck.
2461 #define MEMCG_MAX_HIGH_DELAY_JIFFIES (2UL*HZ)
2464 * When calculating the delay, we use these either side of the exponentiation to
2465 * maintain precision and scale to a reasonable number of jiffies (see the table
2468 * - MEMCG_DELAY_PRECISION_SHIFT: Extra precision bits while translating the
2469 * overage ratio to a delay.
2470 * - MEMCG_DELAY_SCALING_SHIFT: The number of bits to scale down the
2471 * proposed penalty in order to reduce to a reasonable number of jiffies, and
2472 * to produce a reasonable delay curve.
2474 * MEMCG_DELAY_SCALING_SHIFT just happens to be a number that produces a
2475 * reasonable delay curve compared to precision-adjusted overage, not
2476 * penalising heavily at first, but still making sure that growth beyond the
2477 * limit penalises misbehaviour cgroups by slowing them down exponentially. For
2478 * example, with a high of 100 megabytes:
2480 * +-------+------------------------+
2481 * | usage | time to allocate in ms |
2482 * +-------+------------------------+
2504 * +-------+------------------------+
2506 #define MEMCG_DELAY_PRECISION_SHIFT 20
2507 #define MEMCG_DELAY_SCALING_SHIFT 14
2509 static u64
calculate_overage(unsigned long usage
, unsigned long high
)
2517 * Prevent division by 0 in overage calculation by acting as if
2518 * it was a threshold of 1 page
2520 high
= max(high
, 1UL);
2522 overage
= usage
- high
;
2523 overage
<<= MEMCG_DELAY_PRECISION_SHIFT
;
2524 return div64_u64(overage
, high
);
2527 static u64
mem_find_max_overage(struct mem_cgroup
*memcg
)
2529 u64 overage
, max_overage
= 0;
2532 overage
= calculate_overage(page_counter_read(&memcg
->memory
),
2533 READ_ONCE(memcg
->memory
.high
));
2534 max_overage
= max(overage
, max_overage
);
2535 } while ((memcg
= parent_mem_cgroup(memcg
)) &&
2536 !mem_cgroup_is_root(memcg
));
2541 static u64
swap_find_max_overage(struct mem_cgroup
*memcg
)
2543 u64 overage
, max_overage
= 0;
2546 overage
= calculate_overage(page_counter_read(&memcg
->swap
),
2547 READ_ONCE(memcg
->swap
.high
));
2549 memcg_memory_event(memcg
, MEMCG_SWAP_HIGH
);
2550 max_overage
= max(overage
, max_overage
);
2551 } while ((memcg
= parent_mem_cgroup(memcg
)) &&
2552 !mem_cgroup_is_root(memcg
));
2558 * Get the number of jiffies that we should penalise a mischievous cgroup which
2559 * is exceeding its memory.high by checking both it and its ancestors.
2561 static unsigned long calculate_high_delay(struct mem_cgroup
*memcg
,
2562 unsigned int nr_pages
,
2565 unsigned long penalty_jiffies
;
2571 * We use overage compared to memory.high to calculate the number of
2572 * jiffies to sleep (penalty_jiffies). Ideally this value should be
2573 * fairly lenient on small overages, and increasingly harsh when the
2574 * memcg in question makes it clear that it has no intention of stopping
2575 * its crazy behaviour, so we exponentially increase the delay based on
2578 penalty_jiffies
= max_overage
* max_overage
* HZ
;
2579 penalty_jiffies
>>= MEMCG_DELAY_PRECISION_SHIFT
;
2580 penalty_jiffies
>>= MEMCG_DELAY_SCALING_SHIFT
;
2583 * Factor in the task's own contribution to the overage, such that four
2584 * N-sized allocations are throttled approximately the same as one
2585 * 4N-sized allocation.
2587 * MEMCG_CHARGE_BATCH pages is nominal, so work out how much smaller or
2588 * larger the current charge patch is than that.
2590 return penalty_jiffies
* nr_pages
/ MEMCG_CHARGE_BATCH
;
2594 * Scheduled by try_charge() to be executed from the userland return path
2595 * and reclaims memory over the high limit.
2597 void mem_cgroup_handle_over_high(void)
2599 unsigned long penalty_jiffies
;
2600 unsigned long pflags
;
2601 unsigned long nr_reclaimed
;
2602 unsigned int nr_pages
= current
->memcg_nr_pages_over_high
;
2603 int nr_retries
= MAX_RECLAIM_RETRIES
;
2604 struct mem_cgroup
*memcg
;
2605 bool in_retry
= false;
2607 if (likely(!nr_pages
))
2610 memcg
= get_mem_cgroup_from_mm(current
->mm
);
2611 current
->memcg_nr_pages_over_high
= 0;
2615 * The allocating task should reclaim at least the batch size, but for
2616 * subsequent retries we only want to do what's necessary to prevent oom
2617 * or breaching resource isolation.
2619 * This is distinct from memory.max or page allocator behaviour because
2620 * memory.high is currently batched, whereas memory.max and the page
2621 * allocator run every time an allocation is made.
2623 nr_reclaimed
= reclaim_high(memcg
,
2624 in_retry
? SWAP_CLUSTER_MAX
: nr_pages
,
2628 * memory.high is breached and reclaim is unable to keep up. Throttle
2629 * allocators proactively to slow down excessive growth.
2631 penalty_jiffies
= calculate_high_delay(memcg
, nr_pages
,
2632 mem_find_max_overage(memcg
));
2634 penalty_jiffies
+= calculate_high_delay(memcg
, nr_pages
,
2635 swap_find_max_overage(memcg
));
2638 * Clamp the max delay per usermode return so as to still keep the
2639 * application moving forwards and also permit diagnostics, albeit
2642 penalty_jiffies
= min(penalty_jiffies
, MEMCG_MAX_HIGH_DELAY_JIFFIES
);
2645 * Don't sleep if the amount of jiffies this memcg owes us is so low
2646 * that it's not even worth doing, in an attempt to be nice to those who
2647 * go only a small amount over their memory.high value and maybe haven't
2648 * been aggressively reclaimed enough yet.
2650 if (penalty_jiffies
<= HZ
/ 100)
2654 * If reclaim is making forward progress but we're still over
2655 * memory.high, we want to encourage that rather than doing allocator
2658 if (nr_reclaimed
|| nr_retries
--) {
2664 * If we exit early, we're guaranteed to die (since
2665 * schedule_timeout_killable sets TASK_KILLABLE). This means we don't
2666 * need to account for any ill-begotten jiffies to pay them off later.
2668 psi_memstall_enter(&pflags
);
2669 schedule_timeout_killable(penalty_jiffies
);
2670 psi_memstall_leave(&pflags
);
2673 css_put(&memcg
->css
);
2676 static int try_charge(struct mem_cgroup
*memcg
, gfp_t gfp_mask
,
2677 unsigned int nr_pages
)
2679 unsigned int batch
= max(MEMCG_CHARGE_BATCH
, nr_pages
);
2680 int nr_retries
= MAX_RECLAIM_RETRIES
;
2681 struct mem_cgroup
*mem_over_limit
;
2682 struct page_counter
*counter
;
2683 enum oom_status oom_status
;
2684 unsigned long nr_reclaimed
;
2685 bool may_swap
= true;
2686 bool drained
= false;
2687 unsigned long pflags
;
2689 if (mem_cgroup_is_root(memcg
))
2692 if (consume_stock(memcg
, nr_pages
))
2695 if (!do_memsw_account() ||
2696 page_counter_try_charge(&memcg
->memsw
, batch
, &counter
)) {
2697 if (page_counter_try_charge(&memcg
->memory
, batch
, &counter
))
2699 if (do_memsw_account())
2700 page_counter_uncharge(&memcg
->memsw
, batch
);
2701 mem_over_limit
= mem_cgroup_from_counter(counter
, memory
);
2703 mem_over_limit
= mem_cgroup_from_counter(counter
, memsw
);
2707 if (batch
> nr_pages
) {
2713 * Memcg doesn't have a dedicated reserve for atomic
2714 * allocations. But like the global atomic pool, we need to
2715 * put the burden of reclaim on regular allocation requests
2716 * and let these go through as privileged allocations.
2718 if (gfp_mask
& __GFP_ATOMIC
)
2722 * Unlike in global OOM situations, memcg is not in a physical
2723 * memory shortage. Allow dying and OOM-killed tasks to
2724 * bypass the last charges so that they can exit quickly and
2725 * free their memory.
2727 if (unlikely(should_force_charge()))
2731 * Prevent unbounded recursion when reclaim operations need to
2732 * allocate memory. This might exceed the limits temporarily,
2733 * but we prefer facilitating memory reclaim and getting back
2734 * under the limit over triggering OOM kills in these cases.
2736 if (unlikely(current
->flags
& PF_MEMALLOC
))
2739 if (unlikely(task_in_memcg_oom(current
)))
2742 if (!gfpflags_allow_blocking(gfp_mask
))
2745 memcg_memory_event(mem_over_limit
, MEMCG_MAX
);
2747 psi_memstall_enter(&pflags
);
2748 nr_reclaimed
= try_to_free_mem_cgroup_pages(mem_over_limit
, nr_pages
,
2749 gfp_mask
, may_swap
);
2750 psi_memstall_leave(&pflags
);
2752 if (mem_cgroup_margin(mem_over_limit
) >= nr_pages
)
2756 drain_all_stock(mem_over_limit
);
2761 if (gfp_mask
& __GFP_NORETRY
)
2764 * Even though the limit is exceeded at this point, reclaim
2765 * may have been able to free some pages. Retry the charge
2766 * before killing the task.
2768 * Only for regular pages, though: huge pages are rather
2769 * unlikely to succeed so close to the limit, and we fall back
2770 * to regular pages anyway in case of failure.
2772 if (nr_reclaimed
&& nr_pages
<= (1 << PAGE_ALLOC_COSTLY_ORDER
))
2775 * At task move, charge accounts can be doubly counted. So, it's
2776 * better to wait until the end of task_move if something is going on.
2778 if (mem_cgroup_wait_acct_move(mem_over_limit
))
2784 if (gfp_mask
& __GFP_RETRY_MAYFAIL
)
2787 if (gfp_mask
& __GFP_NOFAIL
)
2790 if (fatal_signal_pending(current
))
2794 * keep retrying as long as the memcg oom killer is able to make
2795 * a forward progress or bypass the charge if the oom killer
2796 * couldn't make any progress.
2798 oom_status
= mem_cgroup_oom(mem_over_limit
, gfp_mask
,
2799 get_order(nr_pages
* PAGE_SIZE
));
2800 switch (oom_status
) {
2802 nr_retries
= MAX_RECLAIM_RETRIES
;
2810 if (!(gfp_mask
& __GFP_NOFAIL
))
2814 * The allocation either can't fail or will lead to more memory
2815 * being freed very soon. Allow memory usage go over the limit
2816 * temporarily by force charging it.
2818 page_counter_charge(&memcg
->memory
, nr_pages
);
2819 if (do_memsw_account())
2820 page_counter_charge(&memcg
->memsw
, nr_pages
);
2825 if (batch
> nr_pages
)
2826 refill_stock(memcg
, batch
- nr_pages
);
2829 * If the hierarchy is above the normal consumption range, schedule
2830 * reclaim on returning to userland. We can perform reclaim here
2831 * if __GFP_RECLAIM but let's always punt for simplicity and so that
2832 * GFP_KERNEL can consistently be used during reclaim. @memcg is
2833 * not recorded as it most likely matches current's and won't
2834 * change in the meantime. As high limit is checked again before
2835 * reclaim, the cost of mismatch is negligible.
2838 bool mem_high
, swap_high
;
2840 mem_high
= page_counter_read(&memcg
->memory
) >
2841 READ_ONCE(memcg
->memory
.high
);
2842 swap_high
= page_counter_read(&memcg
->swap
) >
2843 READ_ONCE(memcg
->swap
.high
);
2845 /* Don't bother a random interrupted task */
2846 if (in_interrupt()) {
2848 schedule_work(&memcg
->high_work
);
2854 if (mem_high
|| swap_high
) {
2856 * The allocating tasks in this cgroup will need to do
2857 * reclaim or be throttled to prevent further growth
2858 * of the memory or swap footprints.
2860 * Target some best-effort fairness between the tasks,
2861 * and distribute reclaim work and delay penalties
2862 * based on how much each task is actually allocating.
2864 current
->memcg_nr_pages_over_high
+= batch
;
2865 set_notify_resume(current
);
2868 } while ((memcg
= parent_mem_cgroup(memcg
)));
2873 #if defined(CONFIG_MEMCG_KMEM) || defined(CONFIG_MMU)
2874 static void cancel_charge(struct mem_cgroup
*memcg
, unsigned int nr_pages
)
2876 if (mem_cgroup_is_root(memcg
))
2879 page_counter_uncharge(&memcg
->memory
, nr_pages
);
2880 if (do_memsw_account())
2881 page_counter_uncharge(&memcg
->memsw
, nr_pages
);
2885 static void commit_charge(struct page
*page
, struct mem_cgroup
*memcg
)
2887 VM_BUG_ON_PAGE(page
->mem_cgroup
, page
);
2889 * Any of the following ensures page->mem_cgroup stability:
2893 * - lock_page_memcg()
2894 * - exclusive reference
2896 page
->mem_cgroup
= memcg
;
2899 #ifdef CONFIG_MEMCG_KMEM
2900 int memcg_alloc_page_obj_cgroups(struct page
*page
, struct kmem_cache
*s
,
2903 unsigned int objects
= objs_per_slab_page(s
, page
);
2906 vec
= kcalloc_node(objects
, sizeof(struct obj_cgroup
*), gfp
,
2911 if (cmpxchg(&page
->obj_cgroups
, NULL
,
2912 (struct obj_cgroup
**) ((unsigned long)vec
| 0x1UL
)))
2915 kmemleak_not_leak(vec
);
2921 * Returns a pointer to the memory cgroup to which the kernel object is charged.
2923 * The caller must ensure the memcg lifetime, e.g. by taking rcu_read_lock(),
2924 * cgroup_mutex, etc.
2926 struct mem_cgroup
*mem_cgroup_from_obj(void *p
)
2930 if (mem_cgroup_disabled())
2933 page
= virt_to_head_page(p
);
2936 * If page->mem_cgroup is set, it's either a simple mem_cgroup pointer
2937 * or a pointer to obj_cgroup vector. In the latter case the lowest
2938 * bit of the pointer is set.
2939 * The page->mem_cgroup pointer can be asynchronously changed
2940 * from NULL to (obj_cgroup_vec | 0x1UL), but can't be changed
2941 * from a valid memcg pointer to objcg vector or back.
2943 if (!page
->mem_cgroup
)
2947 * Slab objects are accounted individually, not per-page.
2948 * Memcg membership data for each individual object is saved in
2949 * the page->obj_cgroups.
2951 if (page_has_obj_cgroups(page
)) {
2952 struct obj_cgroup
*objcg
;
2955 off
= obj_to_index(page
->slab_cache
, page
, p
);
2956 objcg
= page_obj_cgroups(page
)[off
];
2958 return obj_cgroup_memcg(objcg
);
2963 /* All other pages use page->mem_cgroup */
2964 return page
->mem_cgroup
;
2967 __always_inline
struct obj_cgroup
*get_obj_cgroup_from_current(void)
2969 struct obj_cgroup
*objcg
= NULL
;
2970 struct mem_cgroup
*memcg
;
2972 if (memcg_kmem_bypass())
2976 if (unlikely(active_memcg()))
2977 memcg
= active_memcg();
2979 memcg
= mem_cgroup_from_task(current
);
2981 for (; memcg
!= root_mem_cgroup
; memcg
= parent_mem_cgroup(memcg
)) {
2982 objcg
= rcu_dereference(memcg
->objcg
);
2983 if (objcg
&& obj_cgroup_tryget(objcg
))
2991 static int memcg_alloc_cache_id(void)
2996 id
= ida_simple_get(&memcg_cache_ida
,
2997 0, MEMCG_CACHES_MAX_SIZE
, GFP_KERNEL
);
3001 if (id
< memcg_nr_cache_ids
)
3005 * There's no space for the new id in memcg_caches arrays,
3006 * so we have to grow them.
3008 down_write(&memcg_cache_ids_sem
);
3010 size
= 2 * (id
+ 1);
3011 if (size
< MEMCG_CACHES_MIN_SIZE
)
3012 size
= MEMCG_CACHES_MIN_SIZE
;
3013 else if (size
> MEMCG_CACHES_MAX_SIZE
)
3014 size
= MEMCG_CACHES_MAX_SIZE
;
3016 err
= memcg_update_all_list_lrus(size
);
3018 memcg_nr_cache_ids
= size
;
3020 up_write(&memcg_cache_ids_sem
);
3023 ida_simple_remove(&memcg_cache_ida
, id
);
3029 static void memcg_free_cache_id(int id
)
3031 ida_simple_remove(&memcg_cache_ida
, id
);
3035 * __memcg_kmem_charge: charge a number of kernel pages to a memcg
3036 * @memcg: memory cgroup to charge
3037 * @gfp: reclaim mode
3038 * @nr_pages: number of pages to charge
3040 * Returns 0 on success, an error code on failure.
3042 int __memcg_kmem_charge(struct mem_cgroup
*memcg
, gfp_t gfp
,
3043 unsigned int nr_pages
)
3045 struct page_counter
*counter
;
3048 ret
= try_charge(memcg
, gfp
, nr_pages
);
3052 if (!cgroup_subsys_on_dfl(memory_cgrp_subsys
) &&
3053 !page_counter_try_charge(&memcg
->kmem
, nr_pages
, &counter
)) {
3056 * Enforce __GFP_NOFAIL allocation because callers are not
3057 * prepared to see failures and likely do not have any failure
3060 if (gfp
& __GFP_NOFAIL
) {
3061 page_counter_charge(&memcg
->kmem
, nr_pages
);
3064 cancel_charge(memcg
, nr_pages
);
3071 * __memcg_kmem_uncharge: uncharge a number of kernel pages from a memcg
3072 * @memcg: memcg to uncharge
3073 * @nr_pages: number of pages to uncharge
3075 void __memcg_kmem_uncharge(struct mem_cgroup
*memcg
, unsigned int nr_pages
)
3077 if (!cgroup_subsys_on_dfl(memory_cgrp_subsys
))
3078 page_counter_uncharge(&memcg
->kmem
, nr_pages
);
3080 page_counter_uncharge(&memcg
->memory
, nr_pages
);
3081 if (do_memsw_account())
3082 page_counter_uncharge(&memcg
->memsw
, nr_pages
);
3086 * __memcg_kmem_charge_page: charge a kmem page to the current memory cgroup
3087 * @page: page to charge
3088 * @gfp: reclaim mode
3089 * @order: allocation order
3091 * Returns 0 on success, an error code on failure.
3093 int __memcg_kmem_charge_page(struct page
*page
, gfp_t gfp
, int order
)
3095 struct mem_cgroup
*memcg
;
3098 memcg
= get_mem_cgroup_from_current();
3099 if (memcg
&& !mem_cgroup_is_root(memcg
)) {
3100 ret
= __memcg_kmem_charge(memcg
, gfp
, 1 << order
);
3102 page
->mem_cgroup
= memcg
;
3103 __SetPageKmemcg(page
);
3106 css_put(&memcg
->css
);
3112 * __memcg_kmem_uncharge_page: uncharge a kmem page
3113 * @page: page to uncharge
3114 * @order: allocation order
3116 void __memcg_kmem_uncharge_page(struct page
*page
, int order
)
3118 struct mem_cgroup
*memcg
= page
->mem_cgroup
;
3119 unsigned int nr_pages
= 1 << order
;
3124 VM_BUG_ON_PAGE(mem_cgroup_is_root(memcg
), page
);
3125 __memcg_kmem_uncharge(memcg
, nr_pages
);
3126 page
->mem_cgroup
= NULL
;
3127 css_put(&memcg
->css
);
3129 /* slab pages do not have PageKmemcg flag set */
3130 if (PageKmemcg(page
))
3131 __ClearPageKmemcg(page
);
3134 static bool consume_obj_stock(struct obj_cgroup
*objcg
, unsigned int nr_bytes
)
3136 struct memcg_stock_pcp
*stock
;
3137 unsigned long flags
;
3140 local_irq_save(flags
);
3142 stock
= this_cpu_ptr(&memcg_stock
);
3143 if (objcg
== stock
->cached_objcg
&& stock
->nr_bytes
>= nr_bytes
) {
3144 stock
->nr_bytes
-= nr_bytes
;
3148 local_irq_restore(flags
);
3153 static void drain_obj_stock(struct memcg_stock_pcp
*stock
)
3155 struct obj_cgroup
*old
= stock
->cached_objcg
;
3160 if (stock
->nr_bytes
) {
3161 unsigned int nr_pages
= stock
->nr_bytes
>> PAGE_SHIFT
;
3162 unsigned int nr_bytes
= stock
->nr_bytes
& (PAGE_SIZE
- 1);
3166 __memcg_kmem_uncharge(obj_cgroup_memcg(old
), nr_pages
);
3171 * The leftover is flushed to the centralized per-memcg value.
3172 * On the next attempt to refill obj stock it will be moved
3173 * to a per-cpu stock (probably, on an other CPU), see
3174 * refill_obj_stock().
3176 * How often it's flushed is a trade-off between the memory
3177 * limit enforcement accuracy and potential CPU contention,
3178 * so it might be changed in the future.
3180 atomic_add(nr_bytes
, &old
->nr_charged_bytes
);
3181 stock
->nr_bytes
= 0;
3184 obj_cgroup_put(old
);
3185 stock
->cached_objcg
= NULL
;
3188 static bool obj_stock_flush_required(struct memcg_stock_pcp
*stock
,
3189 struct mem_cgroup
*root_memcg
)
3191 struct mem_cgroup
*memcg
;
3193 if (stock
->cached_objcg
) {
3194 memcg
= obj_cgroup_memcg(stock
->cached_objcg
);
3195 if (memcg
&& mem_cgroup_is_descendant(memcg
, root_memcg
))
3202 static void refill_obj_stock(struct obj_cgroup
*objcg
, unsigned int nr_bytes
)
3204 struct memcg_stock_pcp
*stock
;
3205 unsigned long flags
;
3207 local_irq_save(flags
);
3209 stock
= this_cpu_ptr(&memcg_stock
);
3210 if (stock
->cached_objcg
!= objcg
) { /* reset if necessary */
3211 drain_obj_stock(stock
);
3212 obj_cgroup_get(objcg
);
3213 stock
->cached_objcg
= objcg
;
3214 stock
->nr_bytes
= atomic_xchg(&objcg
->nr_charged_bytes
, 0);
3216 stock
->nr_bytes
+= nr_bytes
;
3218 if (stock
->nr_bytes
> PAGE_SIZE
)
3219 drain_obj_stock(stock
);
3221 local_irq_restore(flags
);
3224 int obj_cgroup_charge(struct obj_cgroup
*objcg
, gfp_t gfp
, size_t size
)
3226 struct mem_cgroup
*memcg
;
3227 unsigned int nr_pages
, nr_bytes
;
3230 if (consume_obj_stock(objcg
, size
))
3234 * In theory, memcg->nr_charged_bytes can have enough
3235 * pre-charged bytes to satisfy the allocation. However,
3236 * flushing memcg->nr_charged_bytes requires two atomic
3237 * operations, and memcg->nr_charged_bytes can't be big,
3238 * so it's better to ignore it and try grab some new pages.
3239 * memcg->nr_charged_bytes will be flushed in
3240 * refill_obj_stock(), called from this function or
3241 * independently later.
3244 memcg
= obj_cgroup_memcg(objcg
);
3245 css_get(&memcg
->css
);
3248 nr_pages
= size
>> PAGE_SHIFT
;
3249 nr_bytes
= size
& (PAGE_SIZE
- 1);
3254 ret
= __memcg_kmem_charge(memcg
, gfp
, nr_pages
);
3255 if (!ret
&& nr_bytes
)
3256 refill_obj_stock(objcg
, PAGE_SIZE
- nr_bytes
);
3258 css_put(&memcg
->css
);
3262 void obj_cgroup_uncharge(struct obj_cgroup
*objcg
, size_t size
)
3264 refill_obj_stock(objcg
, size
);
3267 #endif /* CONFIG_MEMCG_KMEM */
3269 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
3272 * Because tail pages are not marked as "used", set it. We're under
3273 * pgdat->lru_lock and migration entries setup in all page mappings.
3275 void mem_cgroup_split_huge_fixup(struct page
*head
)
3277 struct mem_cgroup
*memcg
= head
->mem_cgroup
;
3280 if (mem_cgroup_disabled())
3283 for (i
= 1; i
< HPAGE_PMD_NR
; i
++) {
3284 css_get(&memcg
->css
);
3285 head
[i
].mem_cgroup
= memcg
;
3288 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
3290 #ifdef CONFIG_MEMCG_SWAP
3292 * mem_cgroup_move_swap_account - move swap charge and swap_cgroup's record.
3293 * @entry: swap entry to be moved
3294 * @from: mem_cgroup which the entry is moved from
3295 * @to: mem_cgroup which the entry is moved to
3297 * It succeeds only when the swap_cgroup's record for this entry is the same
3298 * as the mem_cgroup's id of @from.
3300 * Returns 0 on success, -EINVAL on failure.
3302 * The caller must have charged to @to, IOW, called page_counter_charge() about
3303 * both res and memsw, and called css_get().
3305 static int mem_cgroup_move_swap_account(swp_entry_t entry
,
3306 struct mem_cgroup
*from
, struct mem_cgroup
*to
)
3308 unsigned short old_id
, new_id
;
3310 old_id
= mem_cgroup_id(from
);
3311 new_id
= mem_cgroup_id(to
);
3313 if (swap_cgroup_cmpxchg(entry
, old_id
, new_id
) == old_id
) {
3314 mod_memcg_state(from
, MEMCG_SWAP
, -1);
3315 mod_memcg_state(to
, MEMCG_SWAP
, 1);
3321 static inline int mem_cgroup_move_swap_account(swp_entry_t entry
,
3322 struct mem_cgroup
*from
, struct mem_cgroup
*to
)
3328 static DEFINE_MUTEX(memcg_max_mutex
);
3330 static int mem_cgroup_resize_max(struct mem_cgroup
*memcg
,
3331 unsigned long max
, bool memsw
)
3333 bool enlarge
= false;
3334 bool drained
= false;
3336 bool limits_invariant
;
3337 struct page_counter
*counter
= memsw
? &memcg
->memsw
: &memcg
->memory
;
3340 if (signal_pending(current
)) {
3345 mutex_lock(&memcg_max_mutex
);
3347 * Make sure that the new limit (memsw or memory limit) doesn't
3348 * break our basic invariant rule memory.max <= memsw.max.
3350 limits_invariant
= memsw
? max
>= READ_ONCE(memcg
->memory
.max
) :
3351 max
<= memcg
->memsw
.max
;
3352 if (!limits_invariant
) {
3353 mutex_unlock(&memcg_max_mutex
);
3357 if (max
> counter
->max
)
3359 ret
= page_counter_set_max(counter
, max
);
3360 mutex_unlock(&memcg_max_mutex
);
3366 drain_all_stock(memcg
);
3371 if (!try_to_free_mem_cgroup_pages(memcg
, 1,
3372 GFP_KERNEL
, !memsw
)) {
3378 if (!ret
&& enlarge
)
3379 memcg_oom_recover(memcg
);
3384 unsigned long mem_cgroup_soft_limit_reclaim(pg_data_t
*pgdat
, int order
,
3386 unsigned long *total_scanned
)
3388 unsigned long nr_reclaimed
= 0;
3389 struct mem_cgroup_per_node
*mz
, *next_mz
= NULL
;
3390 unsigned long reclaimed
;
3392 struct mem_cgroup_tree_per_node
*mctz
;
3393 unsigned long excess
;
3394 unsigned long nr_scanned
;
3399 mctz
= soft_limit_tree_node(pgdat
->node_id
);
3402 * Do not even bother to check the largest node if the root
3403 * is empty. Do it lockless to prevent lock bouncing. Races
3404 * are acceptable as soft limit is best effort anyway.
3406 if (!mctz
|| RB_EMPTY_ROOT(&mctz
->rb_root
))
3410 * This loop can run a while, specially if mem_cgroup's continuously
3411 * keep exceeding their soft limit and putting the system under
3418 mz
= mem_cgroup_largest_soft_limit_node(mctz
);
3423 reclaimed
= mem_cgroup_soft_reclaim(mz
->memcg
, pgdat
,
3424 gfp_mask
, &nr_scanned
);
3425 nr_reclaimed
+= reclaimed
;
3426 *total_scanned
+= nr_scanned
;
3427 spin_lock_irq(&mctz
->lock
);
3428 __mem_cgroup_remove_exceeded(mz
, mctz
);
3431 * If we failed to reclaim anything from this memory cgroup
3432 * it is time to move on to the next cgroup
3436 next_mz
= __mem_cgroup_largest_soft_limit_node(mctz
);
3438 excess
= soft_limit_excess(mz
->memcg
);
3440 * One school of thought says that we should not add
3441 * back the node to the tree if reclaim returns 0.
3442 * But our reclaim could return 0, simply because due
3443 * to priority we are exposing a smaller subset of
3444 * memory to reclaim from. Consider this as a longer
3447 /* If excess == 0, no tree ops */
3448 __mem_cgroup_insert_exceeded(mz
, mctz
, excess
);
3449 spin_unlock_irq(&mctz
->lock
);
3450 css_put(&mz
->memcg
->css
);
3453 * Could not reclaim anything and there are no more
3454 * mem cgroups to try or we seem to be looping without
3455 * reclaiming anything.
3457 if (!nr_reclaimed
&&
3459 loop
> MEM_CGROUP_MAX_SOFT_LIMIT_RECLAIM_LOOPS
))
3461 } while (!nr_reclaimed
);
3463 css_put(&next_mz
->memcg
->css
);
3464 return nr_reclaimed
;
3468 * Test whether @memcg has children, dead or alive. Note that this
3469 * function doesn't care whether @memcg has use_hierarchy enabled and
3470 * returns %true if there are child csses according to the cgroup
3471 * hierarchy. Testing use_hierarchy is the caller's responsibility.
3473 static inline bool memcg_has_children(struct mem_cgroup
*memcg
)
3478 ret
= css_next_child(NULL
, &memcg
->css
);
3484 * Reclaims as many pages from the given memcg as possible.
3486 * Caller is responsible for holding css reference for memcg.
3488 static int mem_cgroup_force_empty(struct mem_cgroup
*memcg
)
3490 int nr_retries
= MAX_RECLAIM_RETRIES
;
3492 /* we call try-to-free pages for make this cgroup empty */
3493 lru_add_drain_all();
3495 drain_all_stock(memcg
);
3497 /* try to free all pages in this cgroup */
3498 while (nr_retries
&& page_counter_read(&memcg
->memory
)) {
3501 if (signal_pending(current
))
3504 progress
= try_to_free_mem_cgroup_pages(memcg
, 1,
3508 /* maybe some writeback is necessary */
3509 congestion_wait(BLK_RW_ASYNC
, HZ
/10);
3517 static ssize_t
mem_cgroup_force_empty_write(struct kernfs_open_file
*of
,
3518 char *buf
, size_t nbytes
,
3521 struct mem_cgroup
*memcg
= mem_cgroup_from_css(of_css(of
));
3523 if (mem_cgroup_is_root(memcg
))
3525 return mem_cgroup_force_empty(memcg
) ?: nbytes
;
3528 static u64
mem_cgroup_hierarchy_read(struct cgroup_subsys_state
*css
,
3531 return mem_cgroup_from_css(css
)->use_hierarchy
;
3534 static int mem_cgroup_hierarchy_write(struct cgroup_subsys_state
*css
,
3535 struct cftype
*cft
, u64 val
)
3538 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
3539 struct mem_cgroup
*parent_memcg
= mem_cgroup_from_css(memcg
->css
.parent
);
3541 if (memcg
->use_hierarchy
== val
)
3545 * If parent's use_hierarchy is set, we can't make any modifications
3546 * in the child subtrees. If it is unset, then the change can
3547 * occur, provided the current cgroup has no children.
3549 * For the root cgroup, parent_mem is NULL, we allow value to be
3550 * set if there are no children.
3552 if ((!parent_memcg
|| !parent_memcg
->use_hierarchy
) &&
3553 (val
== 1 || val
== 0)) {
3554 if (!memcg_has_children(memcg
))
3555 memcg
->use_hierarchy
= val
;
3564 static unsigned long mem_cgroup_usage(struct mem_cgroup
*memcg
, bool swap
)
3568 if (mem_cgroup_is_root(memcg
)) {
3569 val
= memcg_page_state(memcg
, NR_FILE_PAGES
) +
3570 memcg_page_state(memcg
, NR_ANON_MAPPED
);
3572 val
+= memcg_page_state(memcg
, MEMCG_SWAP
);
3575 val
= page_counter_read(&memcg
->memory
);
3577 val
= page_counter_read(&memcg
->memsw
);
3590 static u64
mem_cgroup_read_u64(struct cgroup_subsys_state
*css
,
3593 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
3594 struct page_counter
*counter
;
3596 switch (MEMFILE_TYPE(cft
->private)) {
3598 counter
= &memcg
->memory
;
3601 counter
= &memcg
->memsw
;
3604 counter
= &memcg
->kmem
;
3607 counter
= &memcg
->tcpmem
;
3613 switch (MEMFILE_ATTR(cft
->private)) {
3615 if (counter
== &memcg
->memory
)
3616 return (u64
)mem_cgroup_usage(memcg
, false) * PAGE_SIZE
;
3617 if (counter
== &memcg
->memsw
)
3618 return (u64
)mem_cgroup_usage(memcg
, true) * PAGE_SIZE
;
3619 return (u64
)page_counter_read(counter
) * PAGE_SIZE
;
3621 return (u64
)counter
->max
* PAGE_SIZE
;
3623 return (u64
)counter
->watermark
* PAGE_SIZE
;
3625 return counter
->failcnt
;
3626 case RES_SOFT_LIMIT
:
3627 return (u64
)memcg
->soft_limit
* PAGE_SIZE
;
3633 static void memcg_flush_percpu_vmstats(struct mem_cgroup
*memcg
)
3635 unsigned long stat
[MEMCG_NR_STAT
] = {0};
3636 struct mem_cgroup
*mi
;
3639 for_each_online_cpu(cpu
)
3640 for (i
= 0; i
< MEMCG_NR_STAT
; i
++)
3641 stat
[i
] += per_cpu(memcg
->vmstats_percpu
->stat
[i
], cpu
);
3643 for (mi
= memcg
; mi
; mi
= parent_mem_cgroup(mi
))
3644 for (i
= 0; i
< MEMCG_NR_STAT
; i
++)
3645 atomic_long_add(stat
[i
], &mi
->vmstats
[i
]);
3647 for_each_node(node
) {
3648 struct mem_cgroup_per_node
*pn
= memcg
->nodeinfo
[node
];
3649 struct mem_cgroup_per_node
*pi
;
3651 for (i
= 0; i
< NR_VM_NODE_STAT_ITEMS
; i
++)
3654 for_each_online_cpu(cpu
)
3655 for (i
= 0; i
< NR_VM_NODE_STAT_ITEMS
; i
++)
3657 pn
->lruvec_stat_cpu
->count
[i
], cpu
);
3659 for (pi
= pn
; pi
; pi
= parent_nodeinfo(pi
, node
))
3660 for (i
= 0; i
< NR_VM_NODE_STAT_ITEMS
; i
++)
3661 atomic_long_add(stat
[i
], &pi
->lruvec_stat
[i
]);
3665 static void memcg_flush_percpu_vmevents(struct mem_cgroup
*memcg
)
3667 unsigned long events
[NR_VM_EVENT_ITEMS
];
3668 struct mem_cgroup
*mi
;
3671 for (i
= 0; i
< NR_VM_EVENT_ITEMS
; i
++)
3674 for_each_online_cpu(cpu
)
3675 for (i
= 0; i
< NR_VM_EVENT_ITEMS
; i
++)
3676 events
[i
] += per_cpu(memcg
->vmstats_percpu
->events
[i
],
3679 for (mi
= memcg
; mi
; mi
= parent_mem_cgroup(mi
))
3680 for (i
= 0; i
< NR_VM_EVENT_ITEMS
; i
++)
3681 atomic_long_add(events
[i
], &mi
->vmevents
[i
]);
3684 #ifdef CONFIG_MEMCG_KMEM
3685 static int memcg_online_kmem(struct mem_cgroup
*memcg
)
3687 struct obj_cgroup
*objcg
;
3690 if (cgroup_memory_nokmem
)
3693 BUG_ON(memcg
->kmemcg_id
>= 0);
3694 BUG_ON(memcg
->kmem_state
);
3696 memcg_id
= memcg_alloc_cache_id();
3700 objcg
= obj_cgroup_alloc();
3702 memcg_free_cache_id(memcg_id
);
3705 objcg
->memcg
= memcg
;
3706 rcu_assign_pointer(memcg
->objcg
, objcg
);
3708 static_branch_enable(&memcg_kmem_enabled_key
);
3711 * A memory cgroup is considered kmem-online as soon as it gets
3712 * kmemcg_id. Setting the id after enabling static branching will
3713 * guarantee no one starts accounting before all call sites are
3716 memcg
->kmemcg_id
= memcg_id
;
3717 memcg
->kmem_state
= KMEM_ONLINE
;
3722 static void memcg_offline_kmem(struct mem_cgroup
*memcg
)
3724 struct cgroup_subsys_state
*css
;
3725 struct mem_cgroup
*parent
, *child
;
3728 if (memcg
->kmem_state
!= KMEM_ONLINE
)
3731 memcg
->kmem_state
= KMEM_ALLOCATED
;
3733 parent
= parent_mem_cgroup(memcg
);
3735 parent
= root_mem_cgroup
;
3737 memcg_reparent_objcgs(memcg
, parent
);
3739 kmemcg_id
= memcg
->kmemcg_id
;
3740 BUG_ON(kmemcg_id
< 0);
3743 * Change kmemcg_id of this cgroup and all its descendants to the
3744 * parent's id, and then move all entries from this cgroup's list_lrus
3745 * to ones of the parent. After we have finished, all list_lrus
3746 * corresponding to this cgroup are guaranteed to remain empty. The
3747 * ordering is imposed by list_lru_node->lock taken by
3748 * memcg_drain_all_list_lrus().
3750 rcu_read_lock(); /* can be called from css_free w/o cgroup_mutex */
3751 css_for_each_descendant_pre(css
, &memcg
->css
) {
3752 child
= mem_cgroup_from_css(css
);
3753 BUG_ON(child
->kmemcg_id
!= kmemcg_id
);
3754 child
->kmemcg_id
= parent
->kmemcg_id
;
3755 if (!memcg
->use_hierarchy
)
3760 memcg_drain_all_list_lrus(kmemcg_id
, parent
);
3762 memcg_free_cache_id(kmemcg_id
);
3765 static void memcg_free_kmem(struct mem_cgroup
*memcg
)
3767 /* css_alloc() failed, offlining didn't happen */
3768 if (unlikely(memcg
->kmem_state
== KMEM_ONLINE
))
3769 memcg_offline_kmem(memcg
);
3772 static int memcg_online_kmem(struct mem_cgroup
*memcg
)
3776 static void memcg_offline_kmem(struct mem_cgroup
*memcg
)
3779 static void memcg_free_kmem(struct mem_cgroup
*memcg
)
3782 #endif /* CONFIG_MEMCG_KMEM */
3784 static int memcg_update_kmem_max(struct mem_cgroup
*memcg
,
3789 mutex_lock(&memcg_max_mutex
);
3790 ret
= page_counter_set_max(&memcg
->kmem
, max
);
3791 mutex_unlock(&memcg_max_mutex
);
3795 static int memcg_update_tcp_max(struct mem_cgroup
*memcg
, unsigned long max
)
3799 mutex_lock(&memcg_max_mutex
);
3801 ret
= page_counter_set_max(&memcg
->tcpmem
, max
);
3805 if (!memcg
->tcpmem_active
) {
3807 * The active flag needs to be written after the static_key
3808 * update. This is what guarantees that the socket activation
3809 * function is the last one to run. See mem_cgroup_sk_alloc()
3810 * for details, and note that we don't mark any socket as
3811 * belonging to this memcg until that flag is up.
3813 * We need to do this, because static_keys will span multiple
3814 * sites, but we can't control their order. If we mark a socket
3815 * as accounted, but the accounting functions are not patched in
3816 * yet, we'll lose accounting.
3818 * We never race with the readers in mem_cgroup_sk_alloc(),
3819 * because when this value change, the code to process it is not
3822 static_branch_inc(&memcg_sockets_enabled_key
);
3823 memcg
->tcpmem_active
= true;
3826 mutex_unlock(&memcg_max_mutex
);
3831 * The user of this function is...
3834 static ssize_t
mem_cgroup_write(struct kernfs_open_file
*of
,
3835 char *buf
, size_t nbytes
, loff_t off
)
3837 struct mem_cgroup
*memcg
= mem_cgroup_from_css(of_css(of
));
3838 unsigned long nr_pages
;
3841 buf
= strstrip(buf
);
3842 ret
= page_counter_memparse(buf
, "-1", &nr_pages
);
3846 switch (MEMFILE_ATTR(of_cft(of
)->private)) {
3848 if (mem_cgroup_is_root(memcg
)) { /* Can't set limit on root */
3852 switch (MEMFILE_TYPE(of_cft(of
)->private)) {
3854 ret
= mem_cgroup_resize_max(memcg
, nr_pages
, false);
3857 ret
= mem_cgroup_resize_max(memcg
, nr_pages
, true);
3860 pr_warn_once("kmem.limit_in_bytes is deprecated and will be removed. "
3861 "Please report your usecase to linux-mm@kvack.org if you "
3862 "depend on this functionality.\n");
3863 ret
= memcg_update_kmem_max(memcg
, nr_pages
);
3866 ret
= memcg_update_tcp_max(memcg
, nr_pages
);
3870 case RES_SOFT_LIMIT
:
3871 memcg
->soft_limit
= nr_pages
;
3875 return ret
?: nbytes
;
3878 static ssize_t
mem_cgroup_reset(struct kernfs_open_file
*of
, char *buf
,
3879 size_t nbytes
, loff_t off
)
3881 struct mem_cgroup
*memcg
= mem_cgroup_from_css(of_css(of
));
3882 struct page_counter
*counter
;
3884 switch (MEMFILE_TYPE(of_cft(of
)->private)) {
3886 counter
= &memcg
->memory
;
3889 counter
= &memcg
->memsw
;
3892 counter
= &memcg
->kmem
;
3895 counter
= &memcg
->tcpmem
;
3901 switch (MEMFILE_ATTR(of_cft(of
)->private)) {
3903 page_counter_reset_watermark(counter
);
3906 counter
->failcnt
= 0;
3915 static u64
mem_cgroup_move_charge_read(struct cgroup_subsys_state
*css
,
3918 return mem_cgroup_from_css(css
)->move_charge_at_immigrate
;
3922 static int mem_cgroup_move_charge_write(struct cgroup_subsys_state
*css
,
3923 struct cftype
*cft
, u64 val
)
3925 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
3927 if (val
& ~MOVE_MASK
)
3931 * No kind of locking is needed in here, because ->can_attach() will
3932 * check this value once in the beginning of the process, and then carry
3933 * on with stale data. This means that changes to this value will only
3934 * affect task migrations starting after the change.
3936 memcg
->move_charge_at_immigrate
= val
;
3940 static int mem_cgroup_move_charge_write(struct cgroup_subsys_state
*css
,
3941 struct cftype
*cft
, u64 val
)
3949 #define LRU_ALL_FILE (BIT(LRU_INACTIVE_FILE) | BIT(LRU_ACTIVE_FILE))
3950 #define LRU_ALL_ANON (BIT(LRU_INACTIVE_ANON) | BIT(LRU_ACTIVE_ANON))
3951 #define LRU_ALL ((1 << NR_LRU_LISTS) - 1)
3953 static unsigned long mem_cgroup_node_nr_lru_pages(struct mem_cgroup
*memcg
,
3954 int nid
, unsigned int lru_mask
, bool tree
)
3956 struct lruvec
*lruvec
= mem_cgroup_lruvec(memcg
, NODE_DATA(nid
));
3957 unsigned long nr
= 0;
3960 VM_BUG_ON((unsigned)nid
>= nr_node_ids
);
3963 if (!(BIT(lru
) & lru_mask
))
3966 nr
+= lruvec_page_state(lruvec
, NR_LRU_BASE
+ lru
);
3968 nr
+= lruvec_page_state_local(lruvec
, NR_LRU_BASE
+ lru
);
3973 static unsigned long mem_cgroup_nr_lru_pages(struct mem_cgroup
*memcg
,
3974 unsigned int lru_mask
,
3977 unsigned long nr
= 0;
3981 if (!(BIT(lru
) & lru_mask
))
3984 nr
+= memcg_page_state(memcg
, NR_LRU_BASE
+ lru
);
3986 nr
+= memcg_page_state_local(memcg
, NR_LRU_BASE
+ lru
);
3991 static int memcg_numa_stat_show(struct seq_file
*m
, void *v
)
3995 unsigned int lru_mask
;
3998 static const struct numa_stat stats
[] = {
3999 { "total", LRU_ALL
},
4000 { "file", LRU_ALL_FILE
},
4001 { "anon", LRU_ALL_ANON
},
4002 { "unevictable", BIT(LRU_UNEVICTABLE
) },
4004 const struct numa_stat
*stat
;
4006 struct mem_cgroup
*memcg
= mem_cgroup_from_seq(m
);
4008 for (stat
= stats
; stat
< stats
+ ARRAY_SIZE(stats
); stat
++) {
4009 seq_printf(m
, "%s=%lu", stat
->name
,
4010 mem_cgroup_nr_lru_pages(memcg
, stat
->lru_mask
,
4012 for_each_node_state(nid
, N_MEMORY
)
4013 seq_printf(m
, " N%d=%lu", nid
,
4014 mem_cgroup_node_nr_lru_pages(memcg
, nid
,
4015 stat
->lru_mask
, false));
4019 for (stat
= stats
; stat
< stats
+ ARRAY_SIZE(stats
); stat
++) {
4021 seq_printf(m
, "hierarchical_%s=%lu", stat
->name
,
4022 mem_cgroup_nr_lru_pages(memcg
, stat
->lru_mask
,
4024 for_each_node_state(nid
, N_MEMORY
)
4025 seq_printf(m
, " N%d=%lu", nid
,
4026 mem_cgroup_node_nr_lru_pages(memcg
, nid
,
4027 stat
->lru_mask
, true));
4033 #endif /* CONFIG_NUMA */
4035 static const unsigned int memcg1_stats
[] = {
4038 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
4048 static const char *const memcg1_stat_names
[] = {
4051 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
4061 /* Universal VM events cgroup1 shows, original sort order */
4062 static const unsigned int memcg1_events
[] = {
4069 static int memcg_stat_show(struct seq_file
*m
, void *v
)
4071 struct mem_cgroup
*memcg
= mem_cgroup_from_seq(m
);
4072 unsigned long memory
, memsw
;
4073 struct mem_cgroup
*mi
;
4076 BUILD_BUG_ON(ARRAY_SIZE(memcg1_stat_names
) != ARRAY_SIZE(memcg1_stats
));
4078 for (i
= 0; i
< ARRAY_SIZE(memcg1_stats
); i
++) {
4081 if (memcg1_stats
[i
] == MEMCG_SWAP
&& !do_memsw_account())
4083 nr
= memcg_page_state_local(memcg
, memcg1_stats
[i
]);
4084 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
4085 if (memcg1_stats
[i
] == NR_ANON_THPS
)
4088 seq_printf(m
, "%s %lu\n", memcg1_stat_names
[i
], nr
* PAGE_SIZE
);
4091 for (i
= 0; i
< ARRAY_SIZE(memcg1_events
); i
++)
4092 seq_printf(m
, "%s %lu\n", vm_event_name(memcg1_events
[i
]),
4093 memcg_events_local(memcg
, memcg1_events
[i
]));
4095 for (i
= 0; i
< NR_LRU_LISTS
; i
++)
4096 seq_printf(m
, "%s %lu\n", lru_list_name(i
),
4097 memcg_page_state_local(memcg
, NR_LRU_BASE
+ i
) *
4100 /* Hierarchical information */
4101 memory
= memsw
= PAGE_COUNTER_MAX
;
4102 for (mi
= memcg
; mi
; mi
= parent_mem_cgroup(mi
)) {
4103 memory
= min(memory
, READ_ONCE(mi
->memory
.max
));
4104 memsw
= min(memsw
, READ_ONCE(mi
->memsw
.max
));
4106 seq_printf(m
, "hierarchical_memory_limit %llu\n",
4107 (u64
)memory
* PAGE_SIZE
);
4108 if (do_memsw_account())
4109 seq_printf(m
, "hierarchical_memsw_limit %llu\n",
4110 (u64
)memsw
* PAGE_SIZE
);
4112 for (i
= 0; i
< ARRAY_SIZE(memcg1_stats
); i
++) {
4115 if (memcg1_stats
[i
] == MEMCG_SWAP
&& !do_memsw_account())
4117 nr
= memcg_page_state(memcg
, memcg1_stats
[i
]);
4118 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
4119 if (memcg1_stats
[i
] == NR_ANON_THPS
)
4122 seq_printf(m
, "total_%s %llu\n", memcg1_stat_names
[i
],
4123 (u64
)nr
* PAGE_SIZE
);
4126 for (i
= 0; i
< ARRAY_SIZE(memcg1_events
); i
++)
4127 seq_printf(m
, "total_%s %llu\n",
4128 vm_event_name(memcg1_events
[i
]),
4129 (u64
)memcg_events(memcg
, memcg1_events
[i
]));
4131 for (i
= 0; i
< NR_LRU_LISTS
; i
++)
4132 seq_printf(m
, "total_%s %llu\n", lru_list_name(i
),
4133 (u64
)memcg_page_state(memcg
, NR_LRU_BASE
+ i
) *
4136 #ifdef CONFIG_DEBUG_VM
4139 struct mem_cgroup_per_node
*mz
;
4140 unsigned long anon_cost
= 0;
4141 unsigned long file_cost
= 0;
4143 for_each_online_pgdat(pgdat
) {
4144 mz
= mem_cgroup_nodeinfo(memcg
, pgdat
->node_id
);
4146 anon_cost
+= mz
->lruvec
.anon_cost
;
4147 file_cost
+= mz
->lruvec
.file_cost
;
4149 seq_printf(m
, "anon_cost %lu\n", anon_cost
);
4150 seq_printf(m
, "file_cost %lu\n", file_cost
);
4157 static u64
mem_cgroup_swappiness_read(struct cgroup_subsys_state
*css
,
4160 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
4162 return mem_cgroup_swappiness(memcg
);
4165 static int mem_cgroup_swappiness_write(struct cgroup_subsys_state
*css
,
4166 struct cftype
*cft
, u64 val
)
4168 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
4174 memcg
->swappiness
= val
;
4176 vm_swappiness
= val
;
4181 static void __mem_cgroup_threshold(struct mem_cgroup
*memcg
, bool swap
)
4183 struct mem_cgroup_threshold_ary
*t
;
4184 unsigned long usage
;
4189 t
= rcu_dereference(memcg
->thresholds
.primary
);
4191 t
= rcu_dereference(memcg
->memsw_thresholds
.primary
);
4196 usage
= mem_cgroup_usage(memcg
, swap
);
4199 * current_threshold points to threshold just below or equal to usage.
4200 * If it's not true, a threshold was crossed after last
4201 * call of __mem_cgroup_threshold().
4203 i
= t
->current_threshold
;
4206 * Iterate backward over array of thresholds starting from
4207 * current_threshold and check if a threshold is crossed.
4208 * If none of thresholds below usage is crossed, we read
4209 * only one element of the array here.
4211 for (; i
>= 0 && unlikely(t
->entries
[i
].threshold
> usage
); i
--)
4212 eventfd_signal(t
->entries
[i
].eventfd
, 1);
4214 /* i = current_threshold + 1 */
4218 * Iterate forward over array of thresholds starting from
4219 * current_threshold+1 and check if a threshold is crossed.
4220 * If none of thresholds above usage is crossed, we read
4221 * only one element of the array here.
4223 for (; i
< t
->size
&& unlikely(t
->entries
[i
].threshold
<= usage
); i
++)
4224 eventfd_signal(t
->entries
[i
].eventfd
, 1);
4226 /* Update current_threshold */
4227 t
->current_threshold
= i
- 1;
4232 static void mem_cgroup_threshold(struct mem_cgroup
*memcg
)
4235 __mem_cgroup_threshold(memcg
, false);
4236 if (do_memsw_account())
4237 __mem_cgroup_threshold(memcg
, true);
4239 memcg
= parent_mem_cgroup(memcg
);
4243 static int compare_thresholds(const void *a
, const void *b
)
4245 const struct mem_cgroup_threshold
*_a
= a
;
4246 const struct mem_cgroup_threshold
*_b
= b
;
4248 if (_a
->threshold
> _b
->threshold
)
4251 if (_a
->threshold
< _b
->threshold
)
4257 static int mem_cgroup_oom_notify_cb(struct mem_cgroup
*memcg
)
4259 struct mem_cgroup_eventfd_list
*ev
;
4261 spin_lock(&memcg_oom_lock
);
4263 list_for_each_entry(ev
, &memcg
->oom_notify
, list
)
4264 eventfd_signal(ev
->eventfd
, 1);
4266 spin_unlock(&memcg_oom_lock
);
4270 static void mem_cgroup_oom_notify(struct mem_cgroup
*memcg
)
4272 struct mem_cgroup
*iter
;
4274 for_each_mem_cgroup_tree(iter
, memcg
)
4275 mem_cgroup_oom_notify_cb(iter
);
4278 static int __mem_cgroup_usage_register_event(struct mem_cgroup
*memcg
,
4279 struct eventfd_ctx
*eventfd
, const char *args
, enum res_type type
)
4281 struct mem_cgroup_thresholds
*thresholds
;
4282 struct mem_cgroup_threshold_ary
*new;
4283 unsigned long threshold
;
4284 unsigned long usage
;
4287 ret
= page_counter_memparse(args
, "-1", &threshold
);
4291 mutex_lock(&memcg
->thresholds_lock
);
4294 thresholds
= &memcg
->thresholds
;
4295 usage
= mem_cgroup_usage(memcg
, false);
4296 } else if (type
== _MEMSWAP
) {
4297 thresholds
= &memcg
->memsw_thresholds
;
4298 usage
= mem_cgroup_usage(memcg
, true);
4302 /* Check if a threshold crossed before adding a new one */
4303 if (thresholds
->primary
)
4304 __mem_cgroup_threshold(memcg
, type
== _MEMSWAP
);
4306 size
= thresholds
->primary
? thresholds
->primary
->size
+ 1 : 1;
4308 /* Allocate memory for new array of thresholds */
4309 new = kmalloc(struct_size(new, entries
, size
), GFP_KERNEL
);
4316 /* Copy thresholds (if any) to new array */
4317 if (thresholds
->primary
)
4318 memcpy(new->entries
, thresholds
->primary
->entries
,
4319 flex_array_size(new, entries
, size
- 1));
4321 /* Add new threshold */
4322 new->entries
[size
- 1].eventfd
= eventfd
;
4323 new->entries
[size
- 1].threshold
= threshold
;
4325 /* Sort thresholds. Registering of new threshold isn't time-critical */
4326 sort(new->entries
, size
, sizeof(*new->entries
),
4327 compare_thresholds
, NULL
);
4329 /* Find current threshold */
4330 new->current_threshold
= -1;
4331 for (i
= 0; i
< size
; i
++) {
4332 if (new->entries
[i
].threshold
<= usage
) {
4334 * new->current_threshold will not be used until
4335 * rcu_assign_pointer(), so it's safe to increment
4338 ++new->current_threshold
;
4343 /* Free old spare buffer and save old primary buffer as spare */
4344 kfree(thresholds
->spare
);
4345 thresholds
->spare
= thresholds
->primary
;
4347 rcu_assign_pointer(thresholds
->primary
, new);
4349 /* To be sure that nobody uses thresholds */
4353 mutex_unlock(&memcg
->thresholds_lock
);
4358 static int mem_cgroup_usage_register_event(struct mem_cgroup
*memcg
,
4359 struct eventfd_ctx
*eventfd
, const char *args
)
4361 return __mem_cgroup_usage_register_event(memcg
, eventfd
, args
, _MEM
);
4364 static int memsw_cgroup_usage_register_event(struct mem_cgroup
*memcg
,
4365 struct eventfd_ctx
*eventfd
, const char *args
)
4367 return __mem_cgroup_usage_register_event(memcg
, eventfd
, args
, _MEMSWAP
);
4370 static void __mem_cgroup_usage_unregister_event(struct mem_cgroup
*memcg
,
4371 struct eventfd_ctx
*eventfd
, enum res_type type
)
4373 struct mem_cgroup_thresholds
*thresholds
;
4374 struct mem_cgroup_threshold_ary
*new;
4375 unsigned long usage
;
4376 int i
, j
, size
, entries
;
4378 mutex_lock(&memcg
->thresholds_lock
);
4381 thresholds
= &memcg
->thresholds
;
4382 usage
= mem_cgroup_usage(memcg
, false);
4383 } else if (type
== _MEMSWAP
) {
4384 thresholds
= &memcg
->memsw_thresholds
;
4385 usage
= mem_cgroup_usage(memcg
, true);
4389 if (!thresholds
->primary
)
4392 /* Check if a threshold crossed before removing */
4393 __mem_cgroup_threshold(memcg
, type
== _MEMSWAP
);
4395 /* Calculate new number of threshold */
4397 for (i
= 0; i
< thresholds
->primary
->size
; i
++) {
4398 if (thresholds
->primary
->entries
[i
].eventfd
!= eventfd
)
4404 new = thresholds
->spare
;
4406 /* If no items related to eventfd have been cleared, nothing to do */
4410 /* Set thresholds array to NULL if we don't have thresholds */
4419 /* Copy thresholds and find current threshold */
4420 new->current_threshold
= -1;
4421 for (i
= 0, j
= 0; i
< thresholds
->primary
->size
; i
++) {
4422 if (thresholds
->primary
->entries
[i
].eventfd
== eventfd
)
4425 new->entries
[j
] = thresholds
->primary
->entries
[i
];
4426 if (new->entries
[j
].threshold
<= usage
) {
4428 * new->current_threshold will not be used
4429 * until rcu_assign_pointer(), so it's safe to increment
4432 ++new->current_threshold
;
4438 /* Swap primary and spare array */
4439 thresholds
->spare
= thresholds
->primary
;
4441 rcu_assign_pointer(thresholds
->primary
, new);
4443 /* To be sure that nobody uses thresholds */
4446 /* If all events are unregistered, free the spare array */
4448 kfree(thresholds
->spare
);
4449 thresholds
->spare
= NULL
;
4452 mutex_unlock(&memcg
->thresholds_lock
);
4455 static void mem_cgroup_usage_unregister_event(struct mem_cgroup
*memcg
,
4456 struct eventfd_ctx
*eventfd
)
4458 return __mem_cgroup_usage_unregister_event(memcg
, eventfd
, _MEM
);
4461 static void memsw_cgroup_usage_unregister_event(struct mem_cgroup
*memcg
,
4462 struct eventfd_ctx
*eventfd
)
4464 return __mem_cgroup_usage_unregister_event(memcg
, eventfd
, _MEMSWAP
);
4467 static int mem_cgroup_oom_register_event(struct mem_cgroup
*memcg
,
4468 struct eventfd_ctx
*eventfd
, const char *args
)
4470 struct mem_cgroup_eventfd_list
*event
;
4472 event
= kmalloc(sizeof(*event
), GFP_KERNEL
);
4476 spin_lock(&memcg_oom_lock
);
4478 event
->eventfd
= eventfd
;
4479 list_add(&event
->list
, &memcg
->oom_notify
);
4481 /* already in OOM ? */
4482 if (memcg
->under_oom
)
4483 eventfd_signal(eventfd
, 1);
4484 spin_unlock(&memcg_oom_lock
);
4489 static void mem_cgroup_oom_unregister_event(struct mem_cgroup
*memcg
,
4490 struct eventfd_ctx
*eventfd
)
4492 struct mem_cgroup_eventfd_list
*ev
, *tmp
;
4494 spin_lock(&memcg_oom_lock
);
4496 list_for_each_entry_safe(ev
, tmp
, &memcg
->oom_notify
, list
) {
4497 if (ev
->eventfd
== eventfd
) {
4498 list_del(&ev
->list
);
4503 spin_unlock(&memcg_oom_lock
);
4506 static int mem_cgroup_oom_control_read(struct seq_file
*sf
, void *v
)
4508 struct mem_cgroup
*memcg
= mem_cgroup_from_seq(sf
);
4510 seq_printf(sf
, "oom_kill_disable %d\n", memcg
->oom_kill_disable
);
4511 seq_printf(sf
, "under_oom %d\n", (bool)memcg
->under_oom
);
4512 seq_printf(sf
, "oom_kill %lu\n",
4513 atomic_long_read(&memcg
->memory_events
[MEMCG_OOM_KILL
]));
4517 static int mem_cgroup_oom_control_write(struct cgroup_subsys_state
*css
,
4518 struct cftype
*cft
, u64 val
)
4520 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
4522 /* cannot set to root cgroup and only 0 and 1 are allowed */
4523 if (!css
->parent
|| !((val
== 0) || (val
== 1)))
4526 memcg
->oom_kill_disable
= val
;
4528 memcg_oom_recover(memcg
);
4533 #ifdef CONFIG_CGROUP_WRITEBACK
4535 #include <trace/events/writeback.h>
4537 static int memcg_wb_domain_init(struct mem_cgroup
*memcg
, gfp_t gfp
)
4539 return wb_domain_init(&memcg
->cgwb_domain
, gfp
);
4542 static void memcg_wb_domain_exit(struct mem_cgroup
*memcg
)
4544 wb_domain_exit(&memcg
->cgwb_domain
);
4547 static void memcg_wb_domain_size_changed(struct mem_cgroup
*memcg
)
4549 wb_domain_size_changed(&memcg
->cgwb_domain
);
4552 struct wb_domain
*mem_cgroup_wb_domain(struct bdi_writeback
*wb
)
4554 struct mem_cgroup
*memcg
= mem_cgroup_from_css(wb
->memcg_css
);
4556 if (!memcg
->css
.parent
)
4559 return &memcg
->cgwb_domain
;
4563 * idx can be of type enum memcg_stat_item or node_stat_item.
4564 * Keep in sync with memcg_exact_page().
4566 static unsigned long memcg_exact_page_state(struct mem_cgroup
*memcg
, int idx
)
4568 long x
= atomic_long_read(&memcg
->vmstats
[idx
]);
4571 for_each_online_cpu(cpu
)
4572 x
+= per_cpu_ptr(memcg
->vmstats_percpu
, cpu
)->stat
[idx
];
4579 * mem_cgroup_wb_stats - retrieve writeback related stats from its memcg
4580 * @wb: bdi_writeback in question
4581 * @pfilepages: out parameter for number of file pages
4582 * @pheadroom: out parameter for number of allocatable pages according to memcg
4583 * @pdirty: out parameter for number of dirty pages
4584 * @pwriteback: out parameter for number of pages under writeback
4586 * Determine the numbers of file, headroom, dirty, and writeback pages in
4587 * @wb's memcg. File, dirty and writeback are self-explanatory. Headroom
4588 * is a bit more involved.
4590 * A memcg's headroom is "min(max, high) - used". In the hierarchy, the
4591 * headroom is calculated as the lowest headroom of itself and the
4592 * ancestors. Note that this doesn't consider the actual amount of
4593 * available memory in the system. The caller should further cap
4594 * *@pheadroom accordingly.
4596 void mem_cgroup_wb_stats(struct bdi_writeback
*wb
, unsigned long *pfilepages
,
4597 unsigned long *pheadroom
, unsigned long *pdirty
,
4598 unsigned long *pwriteback
)
4600 struct mem_cgroup
*memcg
= mem_cgroup_from_css(wb
->memcg_css
);
4601 struct mem_cgroup
*parent
;
4603 *pdirty
= memcg_exact_page_state(memcg
, NR_FILE_DIRTY
);
4605 *pwriteback
= memcg_exact_page_state(memcg
, NR_WRITEBACK
);
4606 *pfilepages
= memcg_exact_page_state(memcg
, NR_INACTIVE_FILE
) +
4607 memcg_exact_page_state(memcg
, NR_ACTIVE_FILE
);
4608 *pheadroom
= PAGE_COUNTER_MAX
;
4610 while ((parent
= parent_mem_cgroup(memcg
))) {
4611 unsigned long ceiling
= min(READ_ONCE(memcg
->memory
.max
),
4612 READ_ONCE(memcg
->memory
.high
));
4613 unsigned long used
= page_counter_read(&memcg
->memory
);
4615 *pheadroom
= min(*pheadroom
, ceiling
- min(ceiling
, used
));
4621 * Foreign dirty flushing
4623 * There's an inherent mismatch between memcg and writeback. The former
4624 * trackes ownership per-page while the latter per-inode. This was a
4625 * deliberate design decision because honoring per-page ownership in the
4626 * writeback path is complicated, may lead to higher CPU and IO overheads
4627 * and deemed unnecessary given that write-sharing an inode across
4628 * different cgroups isn't a common use-case.
4630 * Combined with inode majority-writer ownership switching, this works well
4631 * enough in most cases but there are some pathological cases. For
4632 * example, let's say there are two cgroups A and B which keep writing to
4633 * different but confined parts of the same inode. B owns the inode and
4634 * A's memory is limited far below B's. A's dirty ratio can rise enough to
4635 * trigger balance_dirty_pages() sleeps but B's can be low enough to avoid
4636 * triggering background writeback. A will be slowed down without a way to
4637 * make writeback of the dirty pages happen.
4639 * Conditions like the above can lead to a cgroup getting repatedly and
4640 * severely throttled after making some progress after each
4641 * dirty_expire_interval while the underyling IO device is almost
4644 * Solving this problem completely requires matching the ownership tracking
4645 * granularities between memcg and writeback in either direction. However,
4646 * the more egregious behaviors can be avoided by simply remembering the
4647 * most recent foreign dirtying events and initiating remote flushes on
4648 * them when local writeback isn't enough to keep the memory clean enough.
4650 * The following two functions implement such mechanism. When a foreign
4651 * page - a page whose memcg and writeback ownerships don't match - is
4652 * dirtied, mem_cgroup_track_foreign_dirty() records the inode owning
4653 * bdi_writeback on the page owning memcg. When balance_dirty_pages()
4654 * decides that the memcg needs to sleep due to high dirty ratio, it calls
4655 * mem_cgroup_flush_foreign() which queues writeback on the recorded
4656 * foreign bdi_writebacks which haven't expired. Both the numbers of
4657 * recorded bdi_writebacks and concurrent in-flight foreign writebacks are
4658 * limited to MEMCG_CGWB_FRN_CNT.
4660 * The mechanism only remembers IDs and doesn't hold any object references.
4661 * As being wrong occasionally doesn't matter, updates and accesses to the
4662 * records are lockless and racy.
4664 void mem_cgroup_track_foreign_dirty_slowpath(struct page
*page
,
4665 struct bdi_writeback
*wb
)
4667 struct mem_cgroup
*memcg
= page
->mem_cgroup
;
4668 struct memcg_cgwb_frn
*frn
;
4669 u64 now
= get_jiffies_64();
4670 u64 oldest_at
= now
;
4674 trace_track_foreign_dirty(page
, wb
);
4677 * Pick the slot to use. If there is already a slot for @wb, keep
4678 * using it. If not replace the oldest one which isn't being
4681 for (i
= 0; i
< MEMCG_CGWB_FRN_CNT
; i
++) {
4682 frn
= &memcg
->cgwb_frn
[i
];
4683 if (frn
->bdi_id
== wb
->bdi
->id
&&
4684 frn
->memcg_id
== wb
->memcg_css
->id
)
4686 if (time_before64(frn
->at
, oldest_at
) &&
4687 atomic_read(&frn
->done
.cnt
) == 1) {
4689 oldest_at
= frn
->at
;
4693 if (i
< MEMCG_CGWB_FRN_CNT
) {
4695 * Re-using an existing one. Update timestamp lazily to
4696 * avoid making the cacheline hot. We want them to be
4697 * reasonably up-to-date and significantly shorter than
4698 * dirty_expire_interval as that's what expires the record.
4699 * Use the shorter of 1s and dirty_expire_interval / 8.
4701 unsigned long update_intv
=
4702 min_t(unsigned long, HZ
,
4703 msecs_to_jiffies(dirty_expire_interval
* 10) / 8);
4705 if (time_before64(frn
->at
, now
- update_intv
))
4707 } else if (oldest
>= 0) {
4708 /* replace the oldest free one */
4709 frn
= &memcg
->cgwb_frn
[oldest
];
4710 frn
->bdi_id
= wb
->bdi
->id
;
4711 frn
->memcg_id
= wb
->memcg_css
->id
;
4716 /* issue foreign writeback flushes for recorded foreign dirtying events */
4717 void mem_cgroup_flush_foreign(struct bdi_writeback
*wb
)
4719 struct mem_cgroup
*memcg
= mem_cgroup_from_css(wb
->memcg_css
);
4720 unsigned long intv
= msecs_to_jiffies(dirty_expire_interval
* 10);
4721 u64 now
= jiffies_64
;
4724 for (i
= 0; i
< MEMCG_CGWB_FRN_CNT
; i
++) {
4725 struct memcg_cgwb_frn
*frn
= &memcg
->cgwb_frn
[i
];
4728 * If the record is older than dirty_expire_interval,
4729 * writeback on it has already started. No need to kick it
4730 * off again. Also, don't start a new one if there's
4731 * already one in flight.
4733 if (time_after64(frn
->at
, now
- intv
) &&
4734 atomic_read(&frn
->done
.cnt
) == 1) {
4736 trace_flush_foreign(wb
, frn
->bdi_id
, frn
->memcg_id
);
4737 cgroup_writeback_by_id(frn
->bdi_id
, frn
->memcg_id
, 0,
4738 WB_REASON_FOREIGN_FLUSH
,
4744 #else /* CONFIG_CGROUP_WRITEBACK */
4746 static int memcg_wb_domain_init(struct mem_cgroup
*memcg
, gfp_t gfp
)
4751 static void memcg_wb_domain_exit(struct mem_cgroup
*memcg
)
4755 static void memcg_wb_domain_size_changed(struct mem_cgroup
*memcg
)
4759 #endif /* CONFIG_CGROUP_WRITEBACK */
4762 * DO NOT USE IN NEW FILES.
4764 * "cgroup.event_control" implementation.
4766 * This is way over-engineered. It tries to support fully configurable
4767 * events for each user. Such level of flexibility is completely
4768 * unnecessary especially in the light of the planned unified hierarchy.
4770 * Please deprecate this and replace with something simpler if at all
4775 * Unregister event and free resources.
4777 * Gets called from workqueue.
4779 static void memcg_event_remove(struct work_struct
*work
)
4781 struct mem_cgroup_event
*event
=
4782 container_of(work
, struct mem_cgroup_event
, remove
);
4783 struct mem_cgroup
*memcg
= event
->memcg
;
4785 remove_wait_queue(event
->wqh
, &event
->wait
);
4787 event
->unregister_event(memcg
, event
->eventfd
);
4789 /* Notify userspace the event is going away. */
4790 eventfd_signal(event
->eventfd
, 1);
4792 eventfd_ctx_put(event
->eventfd
);
4794 css_put(&memcg
->css
);
4798 * Gets called on EPOLLHUP on eventfd when user closes it.
4800 * Called with wqh->lock held and interrupts disabled.
4802 static int memcg_event_wake(wait_queue_entry_t
*wait
, unsigned mode
,
4803 int sync
, void *key
)
4805 struct mem_cgroup_event
*event
=
4806 container_of(wait
, struct mem_cgroup_event
, wait
);
4807 struct mem_cgroup
*memcg
= event
->memcg
;
4808 __poll_t flags
= key_to_poll(key
);
4810 if (flags
& EPOLLHUP
) {
4812 * If the event has been detached at cgroup removal, we
4813 * can simply return knowing the other side will cleanup
4816 * We can't race against event freeing since the other
4817 * side will require wqh->lock via remove_wait_queue(),
4820 spin_lock(&memcg
->event_list_lock
);
4821 if (!list_empty(&event
->list
)) {
4822 list_del_init(&event
->list
);
4824 * We are in atomic context, but cgroup_event_remove()
4825 * may sleep, so we have to call it in workqueue.
4827 schedule_work(&event
->remove
);
4829 spin_unlock(&memcg
->event_list_lock
);
4835 static void memcg_event_ptable_queue_proc(struct file
*file
,
4836 wait_queue_head_t
*wqh
, poll_table
*pt
)
4838 struct mem_cgroup_event
*event
=
4839 container_of(pt
, struct mem_cgroup_event
, pt
);
4842 add_wait_queue(wqh
, &event
->wait
);
4846 * DO NOT USE IN NEW FILES.
4848 * Parse input and register new cgroup event handler.
4850 * Input must be in format '<event_fd> <control_fd> <args>'.
4851 * Interpretation of args is defined by control file implementation.
4853 static ssize_t
memcg_write_event_control(struct kernfs_open_file
*of
,
4854 char *buf
, size_t nbytes
, loff_t off
)
4856 struct cgroup_subsys_state
*css
= of_css(of
);
4857 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
4858 struct mem_cgroup_event
*event
;
4859 struct cgroup_subsys_state
*cfile_css
;
4860 unsigned int efd
, cfd
;
4867 buf
= strstrip(buf
);
4869 efd
= simple_strtoul(buf
, &endp
, 10);
4874 cfd
= simple_strtoul(buf
, &endp
, 10);
4875 if ((*endp
!= ' ') && (*endp
!= '\0'))
4879 event
= kzalloc(sizeof(*event
), GFP_KERNEL
);
4883 event
->memcg
= memcg
;
4884 INIT_LIST_HEAD(&event
->list
);
4885 init_poll_funcptr(&event
->pt
, memcg_event_ptable_queue_proc
);
4886 init_waitqueue_func_entry(&event
->wait
, memcg_event_wake
);
4887 INIT_WORK(&event
->remove
, memcg_event_remove
);
4895 event
->eventfd
= eventfd_ctx_fileget(efile
.file
);
4896 if (IS_ERR(event
->eventfd
)) {
4897 ret
= PTR_ERR(event
->eventfd
);
4904 goto out_put_eventfd
;
4907 /* the process need read permission on control file */
4908 /* AV: shouldn't we check that it's been opened for read instead? */
4909 ret
= inode_permission(file_inode(cfile
.file
), MAY_READ
);
4914 * Determine the event callbacks and set them in @event. This used
4915 * to be done via struct cftype but cgroup core no longer knows
4916 * about these events. The following is crude but the whole thing
4917 * is for compatibility anyway.
4919 * DO NOT ADD NEW FILES.
4921 name
= cfile
.file
->f_path
.dentry
->d_name
.name
;
4923 if (!strcmp(name
, "memory.usage_in_bytes")) {
4924 event
->register_event
= mem_cgroup_usage_register_event
;
4925 event
->unregister_event
= mem_cgroup_usage_unregister_event
;
4926 } else if (!strcmp(name
, "memory.oom_control")) {
4927 event
->register_event
= mem_cgroup_oom_register_event
;
4928 event
->unregister_event
= mem_cgroup_oom_unregister_event
;
4929 } else if (!strcmp(name
, "memory.pressure_level")) {
4930 event
->register_event
= vmpressure_register_event
;
4931 event
->unregister_event
= vmpressure_unregister_event
;
4932 } else if (!strcmp(name
, "memory.memsw.usage_in_bytes")) {
4933 event
->register_event
= memsw_cgroup_usage_register_event
;
4934 event
->unregister_event
= memsw_cgroup_usage_unregister_event
;
4941 * Verify @cfile should belong to @css. Also, remaining events are
4942 * automatically removed on cgroup destruction but the removal is
4943 * asynchronous, so take an extra ref on @css.
4945 cfile_css
= css_tryget_online_from_dir(cfile
.file
->f_path
.dentry
->d_parent
,
4946 &memory_cgrp_subsys
);
4948 if (IS_ERR(cfile_css
))
4950 if (cfile_css
!= css
) {
4955 ret
= event
->register_event(memcg
, event
->eventfd
, buf
);
4959 vfs_poll(efile
.file
, &event
->pt
);
4961 spin_lock(&memcg
->event_list_lock
);
4962 list_add(&event
->list
, &memcg
->event_list
);
4963 spin_unlock(&memcg
->event_list_lock
);
4975 eventfd_ctx_put(event
->eventfd
);
4984 static struct cftype mem_cgroup_legacy_files
[] = {
4986 .name
= "usage_in_bytes",
4987 .private = MEMFILE_PRIVATE(_MEM
, RES_USAGE
),
4988 .read_u64
= mem_cgroup_read_u64
,
4991 .name
= "max_usage_in_bytes",
4992 .private = MEMFILE_PRIVATE(_MEM
, RES_MAX_USAGE
),
4993 .write
= mem_cgroup_reset
,
4994 .read_u64
= mem_cgroup_read_u64
,
4997 .name
= "limit_in_bytes",
4998 .private = MEMFILE_PRIVATE(_MEM
, RES_LIMIT
),
4999 .write
= mem_cgroup_write
,
5000 .read_u64
= mem_cgroup_read_u64
,
5003 .name
= "soft_limit_in_bytes",
5004 .private = MEMFILE_PRIVATE(_MEM
, RES_SOFT_LIMIT
),
5005 .write
= mem_cgroup_write
,
5006 .read_u64
= mem_cgroup_read_u64
,
5010 .private = MEMFILE_PRIVATE(_MEM
, RES_FAILCNT
),
5011 .write
= mem_cgroup_reset
,
5012 .read_u64
= mem_cgroup_read_u64
,
5016 .seq_show
= memcg_stat_show
,
5019 .name
= "force_empty",
5020 .write
= mem_cgroup_force_empty_write
,
5023 .name
= "use_hierarchy",
5024 .write_u64
= mem_cgroup_hierarchy_write
,
5025 .read_u64
= mem_cgroup_hierarchy_read
,
5028 .name
= "cgroup.event_control", /* XXX: for compat */
5029 .write
= memcg_write_event_control
,
5030 .flags
= CFTYPE_NO_PREFIX
| CFTYPE_WORLD_WRITABLE
,
5033 .name
= "swappiness",
5034 .read_u64
= mem_cgroup_swappiness_read
,
5035 .write_u64
= mem_cgroup_swappiness_write
,
5038 .name
= "move_charge_at_immigrate",
5039 .read_u64
= mem_cgroup_move_charge_read
,
5040 .write_u64
= mem_cgroup_move_charge_write
,
5043 .name
= "oom_control",
5044 .seq_show
= mem_cgroup_oom_control_read
,
5045 .write_u64
= mem_cgroup_oom_control_write
,
5046 .private = MEMFILE_PRIVATE(_OOM_TYPE
, OOM_CONTROL
),
5049 .name
= "pressure_level",
5053 .name
= "numa_stat",
5054 .seq_show
= memcg_numa_stat_show
,
5058 .name
= "kmem.limit_in_bytes",
5059 .private = MEMFILE_PRIVATE(_KMEM
, RES_LIMIT
),
5060 .write
= mem_cgroup_write
,
5061 .read_u64
= mem_cgroup_read_u64
,
5064 .name
= "kmem.usage_in_bytes",
5065 .private = MEMFILE_PRIVATE(_KMEM
, RES_USAGE
),
5066 .read_u64
= mem_cgroup_read_u64
,
5069 .name
= "kmem.failcnt",
5070 .private = MEMFILE_PRIVATE(_KMEM
, RES_FAILCNT
),
5071 .write
= mem_cgroup_reset
,
5072 .read_u64
= mem_cgroup_read_u64
,
5075 .name
= "kmem.max_usage_in_bytes",
5076 .private = MEMFILE_PRIVATE(_KMEM
, RES_MAX_USAGE
),
5077 .write
= mem_cgroup_reset
,
5078 .read_u64
= mem_cgroup_read_u64
,
5080 #if defined(CONFIG_MEMCG_KMEM) && \
5081 (defined(CONFIG_SLAB) || defined(CONFIG_SLUB_DEBUG))
5083 .name
= "kmem.slabinfo",
5084 .seq_show
= memcg_slab_show
,
5088 .name
= "kmem.tcp.limit_in_bytes",
5089 .private = MEMFILE_PRIVATE(_TCP
, RES_LIMIT
),
5090 .write
= mem_cgroup_write
,
5091 .read_u64
= mem_cgroup_read_u64
,
5094 .name
= "kmem.tcp.usage_in_bytes",
5095 .private = MEMFILE_PRIVATE(_TCP
, RES_USAGE
),
5096 .read_u64
= mem_cgroup_read_u64
,
5099 .name
= "kmem.tcp.failcnt",
5100 .private = MEMFILE_PRIVATE(_TCP
, RES_FAILCNT
),
5101 .write
= mem_cgroup_reset
,
5102 .read_u64
= mem_cgroup_read_u64
,
5105 .name
= "kmem.tcp.max_usage_in_bytes",
5106 .private = MEMFILE_PRIVATE(_TCP
, RES_MAX_USAGE
),
5107 .write
= mem_cgroup_reset
,
5108 .read_u64
= mem_cgroup_read_u64
,
5110 { }, /* terminate */
5114 * Private memory cgroup IDR
5116 * Swap-out records and page cache shadow entries need to store memcg
5117 * references in constrained space, so we maintain an ID space that is
5118 * limited to 16 bit (MEM_CGROUP_ID_MAX), limiting the total number of
5119 * memory-controlled cgroups to 64k.
5121 * However, there usually are many references to the offline CSS after
5122 * the cgroup has been destroyed, such as page cache or reclaimable
5123 * slab objects, that don't need to hang on to the ID. We want to keep
5124 * those dead CSS from occupying IDs, or we might quickly exhaust the
5125 * relatively small ID space and prevent the creation of new cgroups
5126 * even when there are much fewer than 64k cgroups - possibly none.
5128 * Maintain a private 16-bit ID space for memcg, and allow the ID to
5129 * be freed and recycled when it's no longer needed, which is usually
5130 * when the CSS is offlined.
5132 * The only exception to that are records of swapped out tmpfs/shmem
5133 * pages that need to be attributed to live ancestors on swapin. But
5134 * those references are manageable from userspace.
5137 static DEFINE_IDR(mem_cgroup_idr
);
5139 static void mem_cgroup_id_remove(struct mem_cgroup
*memcg
)
5141 if (memcg
->id
.id
> 0) {
5142 idr_remove(&mem_cgroup_idr
, memcg
->id
.id
);
5147 static void __maybe_unused
mem_cgroup_id_get_many(struct mem_cgroup
*memcg
,
5150 refcount_add(n
, &memcg
->id
.ref
);
5153 static void mem_cgroup_id_put_many(struct mem_cgroup
*memcg
, unsigned int n
)
5155 if (refcount_sub_and_test(n
, &memcg
->id
.ref
)) {
5156 mem_cgroup_id_remove(memcg
);
5158 /* Memcg ID pins CSS */
5159 css_put(&memcg
->css
);
5163 static inline void mem_cgroup_id_put(struct mem_cgroup
*memcg
)
5165 mem_cgroup_id_put_many(memcg
, 1);
5169 * mem_cgroup_from_id - look up a memcg from a memcg id
5170 * @id: the memcg id to look up
5172 * Caller must hold rcu_read_lock().
5174 struct mem_cgroup
*mem_cgroup_from_id(unsigned short id
)
5176 WARN_ON_ONCE(!rcu_read_lock_held());
5177 return idr_find(&mem_cgroup_idr
, id
);
5180 static int alloc_mem_cgroup_per_node_info(struct mem_cgroup
*memcg
, int node
)
5182 struct mem_cgroup_per_node
*pn
;
5185 * This routine is called against possible nodes.
5186 * But it's BUG to call kmalloc() against offline node.
5188 * TODO: this routine can waste much memory for nodes which will
5189 * never be onlined. It's better to use memory hotplug callback
5192 if (!node_state(node
, N_NORMAL_MEMORY
))
5194 pn
= kzalloc_node(sizeof(*pn
), GFP_KERNEL
, tmp
);
5198 pn
->lruvec_stat_local
= alloc_percpu_gfp(struct lruvec_stat
,
5199 GFP_KERNEL_ACCOUNT
);
5200 if (!pn
->lruvec_stat_local
) {
5205 pn
->lruvec_stat_cpu
= alloc_percpu_gfp(struct lruvec_stat
,
5206 GFP_KERNEL_ACCOUNT
);
5207 if (!pn
->lruvec_stat_cpu
) {
5208 free_percpu(pn
->lruvec_stat_local
);
5213 lruvec_init(&pn
->lruvec
);
5214 pn
->usage_in_excess
= 0;
5215 pn
->on_tree
= false;
5218 memcg
->nodeinfo
[node
] = pn
;
5222 static void free_mem_cgroup_per_node_info(struct mem_cgroup
*memcg
, int node
)
5224 struct mem_cgroup_per_node
*pn
= memcg
->nodeinfo
[node
];
5229 free_percpu(pn
->lruvec_stat_cpu
);
5230 free_percpu(pn
->lruvec_stat_local
);
5234 static void __mem_cgroup_free(struct mem_cgroup
*memcg
)
5239 free_mem_cgroup_per_node_info(memcg
, node
);
5240 free_percpu(memcg
->vmstats_percpu
);
5241 free_percpu(memcg
->vmstats_local
);
5245 static void mem_cgroup_free(struct mem_cgroup
*memcg
)
5247 memcg_wb_domain_exit(memcg
);
5249 * Flush percpu vmstats and vmevents to guarantee the value correctness
5250 * on parent's and all ancestor levels.
5252 memcg_flush_percpu_vmstats(memcg
);
5253 memcg_flush_percpu_vmevents(memcg
);
5254 __mem_cgroup_free(memcg
);
5257 static struct mem_cgroup
*mem_cgroup_alloc(void)
5259 struct mem_cgroup
*memcg
;
5262 int __maybe_unused i
;
5263 long error
= -ENOMEM
;
5265 size
= sizeof(struct mem_cgroup
);
5266 size
+= nr_node_ids
* sizeof(struct mem_cgroup_per_node
*);
5268 memcg
= kzalloc(size
, GFP_KERNEL
);
5270 return ERR_PTR(error
);
5272 memcg
->id
.id
= idr_alloc(&mem_cgroup_idr
, NULL
,
5273 1, MEM_CGROUP_ID_MAX
,
5275 if (memcg
->id
.id
< 0) {
5276 error
= memcg
->id
.id
;
5280 memcg
->vmstats_local
= alloc_percpu_gfp(struct memcg_vmstats_percpu
,
5281 GFP_KERNEL_ACCOUNT
);
5282 if (!memcg
->vmstats_local
)
5285 memcg
->vmstats_percpu
= alloc_percpu_gfp(struct memcg_vmstats_percpu
,
5286 GFP_KERNEL_ACCOUNT
);
5287 if (!memcg
->vmstats_percpu
)
5291 if (alloc_mem_cgroup_per_node_info(memcg
, node
))
5294 if (memcg_wb_domain_init(memcg
, GFP_KERNEL
))
5297 INIT_WORK(&memcg
->high_work
, high_work_func
);
5298 INIT_LIST_HEAD(&memcg
->oom_notify
);
5299 mutex_init(&memcg
->thresholds_lock
);
5300 spin_lock_init(&memcg
->move_lock
);
5301 vmpressure_init(&memcg
->vmpressure
);
5302 INIT_LIST_HEAD(&memcg
->event_list
);
5303 spin_lock_init(&memcg
->event_list_lock
);
5304 memcg
->socket_pressure
= jiffies
;
5305 #ifdef CONFIG_MEMCG_KMEM
5306 memcg
->kmemcg_id
= -1;
5307 INIT_LIST_HEAD(&memcg
->objcg_list
);
5309 #ifdef CONFIG_CGROUP_WRITEBACK
5310 INIT_LIST_HEAD(&memcg
->cgwb_list
);
5311 for (i
= 0; i
< MEMCG_CGWB_FRN_CNT
; i
++)
5312 memcg
->cgwb_frn
[i
].done
=
5313 __WB_COMPLETION_INIT(&memcg_cgwb_frn_waitq
);
5315 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
5316 spin_lock_init(&memcg
->deferred_split_queue
.split_queue_lock
);
5317 INIT_LIST_HEAD(&memcg
->deferred_split_queue
.split_queue
);
5318 memcg
->deferred_split_queue
.split_queue_len
= 0;
5320 idr_replace(&mem_cgroup_idr
, memcg
, memcg
->id
.id
);
5323 mem_cgroup_id_remove(memcg
);
5324 __mem_cgroup_free(memcg
);
5325 return ERR_PTR(error
);
5328 static struct cgroup_subsys_state
* __ref
5329 mem_cgroup_css_alloc(struct cgroup_subsys_state
*parent_css
)
5331 struct mem_cgroup
*parent
= mem_cgroup_from_css(parent_css
);
5332 struct mem_cgroup
*memcg
, *old_memcg
;
5333 long error
= -ENOMEM
;
5335 old_memcg
= set_active_memcg(parent
);
5336 memcg
= mem_cgroup_alloc();
5337 set_active_memcg(old_memcg
);
5339 return ERR_CAST(memcg
);
5341 page_counter_set_high(&memcg
->memory
, PAGE_COUNTER_MAX
);
5342 memcg
->soft_limit
= PAGE_COUNTER_MAX
;
5343 page_counter_set_high(&memcg
->swap
, PAGE_COUNTER_MAX
);
5345 memcg
->swappiness
= mem_cgroup_swappiness(parent
);
5346 memcg
->oom_kill_disable
= parent
->oom_kill_disable
;
5349 page_counter_init(&memcg
->memory
, NULL
);
5350 page_counter_init(&memcg
->swap
, NULL
);
5351 page_counter_init(&memcg
->kmem
, NULL
);
5352 page_counter_init(&memcg
->tcpmem
, NULL
);
5353 } else if (parent
->use_hierarchy
) {
5354 memcg
->use_hierarchy
= true;
5355 page_counter_init(&memcg
->memory
, &parent
->memory
);
5356 page_counter_init(&memcg
->swap
, &parent
->swap
);
5357 page_counter_init(&memcg
->kmem
, &parent
->kmem
);
5358 page_counter_init(&memcg
->tcpmem
, &parent
->tcpmem
);
5360 page_counter_init(&memcg
->memory
, &root_mem_cgroup
->memory
);
5361 page_counter_init(&memcg
->swap
, &root_mem_cgroup
->swap
);
5362 page_counter_init(&memcg
->kmem
, &root_mem_cgroup
->kmem
);
5363 page_counter_init(&memcg
->tcpmem
, &root_mem_cgroup
->tcpmem
);
5365 * Deeper hierachy with use_hierarchy == false doesn't make
5366 * much sense so let cgroup subsystem know about this
5367 * unfortunate state in our controller.
5369 if (parent
!= root_mem_cgroup
)
5370 memory_cgrp_subsys
.broken_hierarchy
= true;
5373 /* The following stuff does not apply to the root */
5375 root_mem_cgroup
= memcg
;
5379 error
= memcg_online_kmem(memcg
);
5383 if (cgroup_subsys_on_dfl(memory_cgrp_subsys
) && !cgroup_memory_nosocket
)
5384 static_branch_inc(&memcg_sockets_enabled_key
);
5388 mem_cgroup_id_remove(memcg
);
5389 mem_cgroup_free(memcg
);
5390 return ERR_PTR(error
);
5393 static int mem_cgroup_css_online(struct cgroup_subsys_state
*css
)
5395 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
5398 * A memcg must be visible for memcg_expand_shrinker_maps()
5399 * by the time the maps are allocated. So, we allocate maps
5400 * here, when for_each_mem_cgroup() can't skip it.
5402 if (memcg_alloc_shrinker_maps(memcg
)) {
5403 mem_cgroup_id_remove(memcg
);
5407 /* Online state pins memcg ID, memcg ID pins CSS */
5408 refcount_set(&memcg
->id
.ref
, 1);
5413 static void mem_cgroup_css_offline(struct cgroup_subsys_state
*css
)
5415 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
5416 struct mem_cgroup_event
*event
, *tmp
;
5419 * Unregister events and notify userspace.
5420 * Notify userspace about cgroup removing only after rmdir of cgroup
5421 * directory to avoid race between userspace and kernelspace.
5423 spin_lock(&memcg
->event_list_lock
);
5424 list_for_each_entry_safe(event
, tmp
, &memcg
->event_list
, list
) {
5425 list_del_init(&event
->list
);
5426 schedule_work(&event
->remove
);
5428 spin_unlock(&memcg
->event_list_lock
);
5430 page_counter_set_min(&memcg
->memory
, 0);
5431 page_counter_set_low(&memcg
->memory
, 0);
5433 memcg_offline_kmem(memcg
);
5434 wb_memcg_offline(memcg
);
5436 drain_all_stock(memcg
);
5438 mem_cgroup_id_put(memcg
);
5441 static void mem_cgroup_css_released(struct cgroup_subsys_state
*css
)
5443 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
5445 invalidate_reclaim_iterators(memcg
);
5448 static void mem_cgroup_css_free(struct cgroup_subsys_state
*css
)
5450 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
5451 int __maybe_unused i
;
5453 #ifdef CONFIG_CGROUP_WRITEBACK
5454 for (i
= 0; i
< MEMCG_CGWB_FRN_CNT
; i
++)
5455 wb_wait_for_completion(&memcg
->cgwb_frn
[i
].done
);
5457 if (cgroup_subsys_on_dfl(memory_cgrp_subsys
) && !cgroup_memory_nosocket
)
5458 static_branch_dec(&memcg_sockets_enabled_key
);
5460 if (!cgroup_subsys_on_dfl(memory_cgrp_subsys
) && memcg
->tcpmem_active
)
5461 static_branch_dec(&memcg_sockets_enabled_key
);
5463 vmpressure_cleanup(&memcg
->vmpressure
);
5464 cancel_work_sync(&memcg
->high_work
);
5465 mem_cgroup_remove_from_trees(memcg
);
5466 memcg_free_shrinker_maps(memcg
);
5467 memcg_free_kmem(memcg
);
5468 mem_cgroup_free(memcg
);
5472 * mem_cgroup_css_reset - reset the states of a mem_cgroup
5473 * @css: the target css
5475 * Reset the states of the mem_cgroup associated with @css. This is
5476 * invoked when the userland requests disabling on the default hierarchy
5477 * but the memcg is pinned through dependency. The memcg should stop
5478 * applying policies and should revert to the vanilla state as it may be
5479 * made visible again.
5481 * The current implementation only resets the essential configurations.
5482 * This needs to be expanded to cover all the visible parts.
5484 static void mem_cgroup_css_reset(struct cgroup_subsys_state
*css
)
5486 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
5488 page_counter_set_max(&memcg
->memory
, PAGE_COUNTER_MAX
);
5489 page_counter_set_max(&memcg
->swap
, PAGE_COUNTER_MAX
);
5490 page_counter_set_max(&memcg
->kmem
, PAGE_COUNTER_MAX
);
5491 page_counter_set_max(&memcg
->tcpmem
, PAGE_COUNTER_MAX
);
5492 page_counter_set_min(&memcg
->memory
, 0);
5493 page_counter_set_low(&memcg
->memory
, 0);
5494 page_counter_set_high(&memcg
->memory
, PAGE_COUNTER_MAX
);
5495 memcg
->soft_limit
= PAGE_COUNTER_MAX
;
5496 page_counter_set_high(&memcg
->swap
, PAGE_COUNTER_MAX
);
5497 memcg_wb_domain_size_changed(memcg
);
5501 /* Handlers for move charge at task migration. */
5502 static int mem_cgroup_do_precharge(unsigned long count
)
5506 /* Try a single bulk charge without reclaim first, kswapd may wake */
5507 ret
= try_charge(mc
.to
, GFP_KERNEL
& ~__GFP_DIRECT_RECLAIM
, count
);
5509 mc
.precharge
+= count
;
5513 /* Try charges one by one with reclaim, but do not retry */
5515 ret
= try_charge(mc
.to
, GFP_KERNEL
| __GFP_NORETRY
, 1);
5529 enum mc_target_type
{
5536 static struct page
*mc_handle_present_pte(struct vm_area_struct
*vma
,
5537 unsigned long addr
, pte_t ptent
)
5539 struct page
*page
= vm_normal_page(vma
, addr
, ptent
);
5541 if (!page
|| !page_mapped(page
))
5543 if (PageAnon(page
)) {
5544 if (!(mc
.flags
& MOVE_ANON
))
5547 if (!(mc
.flags
& MOVE_FILE
))
5550 if (!get_page_unless_zero(page
))
5556 #if defined(CONFIG_SWAP) || defined(CONFIG_DEVICE_PRIVATE)
5557 static struct page
*mc_handle_swap_pte(struct vm_area_struct
*vma
,
5558 pte_t ptent
, swp_entry_t
*entry
)
5560 struct page
*page
= NULL
;
5561 swp_entry_t ent
= pte_to_swp_entry(ptent
);
5563 if (!(mc
.flags
& MOVE_ANON
))
5567 * Handle MEMORY_DEVICE_PRIVATE which are ZONE_DEVICE page belonging to
5568 * a device and because they are not accessible by CPU they are store
5569 * as special swap entry in the CPU page table.
5571 if (is_device_private_entry(ent
)) {
5572 page
= device_private_entry_to_page(ent
);
5574 * MEMORY_DEVICE_PRIVATE means ZONE_DEVICE page and which have
5575 * a refcount of 1 when free (unlike normal page)
5577 if (!page_ref_add_unless(page
, 1, 1))
5582 if (non_swap_entry(ent
))
5586 * Because lookup_swap_cache() updates some statistics counter,
5587 * we call find_get_page() with swapper_space directly.
5589 page
= find_get_page(swap_address_space(ent
), swp_offset(ent
));
5590 entry
->val
= ent
.val
;
5595 static struct page
*mc_handle_swap_pte(struct vm_area_struct
*vma
,
5596 pte_t ptent
, swp_entry_t
*entry
)
5602 static struct page
*mc_handle_file_pte(struct vm_area_struct
*vma
,
5603 unsigned long addr
, pte_t ptent
, swp_entry_t
*entry
)
5605 if (!vma
->vm_file
) /* anonymous vma */
5607 if (!(mc
.flags
& MOVE_FILE
))
5610 /* page is moved even if it's not RSS of this task(page-faulted). */
5611 /* shmem/tmpfs may report page out on swap: account for that too. */
5612 return find_get_incore_page(vma
->vm_file
->f_mapping
,
5613 linear_page_index(vma
, addr
));
5617 * mem_cgroup_move_account - move account of the page
5619 * @compound: charge the page as compound or small page
5620 * @from: mem_cgroup which the page is moved from.
5621 * @to: mem_cgroup which the page is moved to. @from != @to.
5623 * The caller must make sure the page is not on LRU (isolate_page() is useful.)
5625 * This function doesn't do "charge" to new cgroup and doesn't do "uncharge"
5628 static int mem_cgroup_move_account(struct page
*page
,
5630 struct mem_cgroup
*from
,
5631 struct mem_cgroup
*to
)
5633 struct lruvec
*from_vec
, *to_vec
;
5634 struct pglist_data
*pgdat
;
5635 unsigned int nr_pages
= compound
? thp_nr_pages(page
) : 1;
5638 VM_BUG_ON(from
== to
);
5639 VM_BUG_ON_PAGE(PageLRU(page
), page
);
5640 VM_BUG_ON(compound
&& !PageTransHuge(page
));
5643 * Prevent mem_cgroup_migrate() from looking at
5644 * page->mem_cgroup of its source page while we change it.
5647 if (!trylock_page(page
))
5651 if (page
->mem_cgroup
!= from
)
5654 pgdat
= page_pgdat(page
);
5655 from_vec
= mem_cgroup_lruvec(from
, pgdat
);
5656 to_vec
= mem_cgroup_lruvec(to
, pgdat
);
5658 lock_page_memcg(page
);
5660 if (PageAnon(page
)) {
5661 if (page_mapped(page
)) {
5662 __mod_lruvec_state(from_vec
, NR_ANON_MAPPED
, -nr_pages
);
5663 __mod_lruvec_state(to_vec
, NR_ANON_MAPPED
, nr_pages
);
5664 if (PageTransHuge(page
)) {
5665 __mod_lruvec_state(from_vec
, NR_ANON_THPS
,
5667 __mod_lruvec_state(to_vec
, NR_ANON_THPS
,
5673 __mod_lruvec_state(from_vec
, NR_FILE_PAGES
, -nr_pages
);
5674 __mod_lruvec_state(to_vec
, NR_FILE_PAGES
, nr_pages
);
5676 if (PageSwapBacked(page
)) {
5677 __mod_lruvec_state(from_vec
, NR_SHMEM
, -nr_pages
);
5678 __mod_lruvec_state(to_vec
, NR_SHMEM
, nr_pages
);
5681 if (page_mapped(page
)) {
5682 __mod_lruvec_state(from_vec
, NR_FILE_MAPPED
, -nr_pages
);
5683 __mod_lruvec_state(to_vec
, NR_FILE_MAPPED
, nr_pages
);
5686 if (PageDirty(page
)) {
5687 struct address_space
*mapping
= page_mapping(page
);
5689 if (mapping_can_writeback(mapping
)) {
5690 __mod_lruvec_state(from_vec
, NR_FILE_DIRTY
,
5692 __mod_lruvec_state(to_vec
, NR_FILE_DIRTY
,
5698 if (PageWriteback(page
)) {
5699 __mod_lruvec_state(from_vec
, NR_WRITEBACK
, -nr_pages
);
5700 __mod_lruvec_state(to_vec
, NR_WRITEBACK
, nr_pages
);
5704 * All state has been migrated, let's switch to the new memcg.
5706 * It is safe to change page->mem_cgroup here because the page
5707 * is referenced, charged, isolated, and locked: we can't race
5708 * with (un)charging, migration, LRU putback, or anything else
5709 * that would rely on a stable page->mem_cgroup.
5711 * Note that lock_page_memcg is a memcg lock, not a page lock,
5712 * to save space. As soon as we switch page->mem_cgroup to a
5713 * new memcg that isn't locked, the above state can change
5714 * concurrently again. Make sure we're truly done with it.
5719 css_put(&from
->css
);
5721 page
->mem_cgroup
= to
;
5723 __unlock_page_memcg(from
);
5727 local_irq_disable();
5728 mem_cgroup_charge_statistics(to
, page
, nr_pages
);
5729 memcg_check_events(to
, page
);
5730 mem_cgroup_charge_statistics(from
, page
, -nr_pages
);
5731 memcg_check_events(from
, page
);
5740 * get_mctgt_type - get target type of moving charge
5741 * @vma: the vma the pte to be checked belongs
5742 * @addr: the address corresponding to the pte to be checked
5743 * @ptent: the pte to be checked
5744 * @target: the pointer the target page or swap ent will be stored(can be NULL)
5747 * 0(MC_TARGET_NONE): if the pte is not a target for move charge.
5748 * 1(MC_TARGET_PAGE): if the page corresponding to this pte is a target for
5749 * move charge. if @target is not NULL, the page is stored in target->page
5750 * with extra refcnt got(Callers should handle it).
5751 * 2(MC_TARGET_SWAP): if the swap entry corresponding to this pte is a
5752 * target for charge migration. if @target is not NULL, the entry is stored
5754 * 3(MC_TARGET_DEVICE): like MC_TARGET_PAGE but page is MEMORY_DEVICE_PRIVATE
5755 * (so ZONE_DEVICE page and thus not on the lru).
5756 * For now we such page is charge like a regular page would be as for all
5757 * intent and purposes it is just special memory taking the place of a
5760 * See Documentations/vm/hmm.txt and include/linux/hmm.h
5762 * Called with pte lock held.
5765 static enum mc_target_type
get_mctgt_type(struct vm_area_struct
*vma
,
5766 unsigned long addr
, pte_t ptent
, union mc_target
*target
)
5768 struct page
*page
= NULL
;
5769 enum mc_target_type ret
= MC_TARGET_NONE
;
5770 swp_entry_t ent
= { .val
= 0 };
5772 if (pte_present(ptent
))
5773 page
= mc_handle_present_pte(vma
, addr
, ptent
);
5774 else if (is_swap_pte(ptent
))
5775 page
= mc_handle_swap_pte(vma
, ptent
, &ent
);
5776 else if (pte_none(ptent
))
5777 page
= mc_handle_file_pte(vma
, addr
, ptent
, &ent
);
5779 if (!page
&& !ent
.val
)
5783 * Do only loose check w/o serialization.
5784 * mem_cgroup_move_account() checks the page is valid or
5785 * not under LRU exclusion.
5787 if (page
->mem_cgroup
== mc
.from
) {
5788 ret
= MC_TARGET_PAGE
;
5789 if (is_device_private_page(page
))
5790 ret
= MC_TARGET_DEVICE
;
5792 target
->page
= page
;
5794 if (!ret
|| !target
)
5798 * There is a swap entry and a page doesn't exist or isn't charged.
5799 * But we cannot move a tail-page in a THP.
5801 if (ent
.val
&& !ret
&& (!page
|| !PageTransCompound(page
)) &&
5802 mem_cgroup_id(mc
.from
) == lookup_swap_cgroup_id(ent
)) {
5803 ret
= MC_TARGET_SWAP
;
5810 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
5812 * We don't consider PMD mapped swapping or file mapped pages because THP does
5813 * not support them for now.
5814 * Caller should make sure that pmd_trans_huge(pmd) is true.
5816 static enum mc_target_type
get_mctgt_type_thp(struct vm_area_struct
*vma
,
5817 unsigned long addr
, pmd_t pmd
, union mc_target
*target
)
5819 struct page
*page
= NULL
;
5820 enum mc_target_type ret
= MC_TARGET_NONE
;
5822 if (unlikely(is_swap_pmd(pmd
))) {
5823 VM_BUG_ON(thp_migration_supported() &&
5824 !is_pmd_migration_entry(pmd
));
5827 page
= pmd_page(pmd
);
5828 VM_BUG_ON_PAGE(!page
|| !PageHead(page
), page
);
5829 if (!(mc
.flags
& MOVE_ANON
))
5831 if (page
->mem_cgroup
== mc
.from
) {
5832 ret
= MC_TARGET_PAGE
;
5835 target
->page
= page
;
5841 static inline enum mc_target_type
get_mctgt_type_thp(struct vm_area_struct
*vma
,
5842 unsigned long addr
, pmd_t pmd
, union mc_target
*target
)
5844 return MC_TARGET_NONE
;
5848 static int mem_cgroup_count_precharge_pte_range(pmd_t
*pmd
,
5849 unsigned long addr
, unsigned long end
,
5850 struct mm_walk
*walk
)
5852 struct vm_area_struct
*vma
= walk
->vma
;
5856 ptl
= pmd_trans_huge_lock(pmd
, vma
);
5859 * Note their can not be MC_TARGET_DEVICE for now as we do not
5860 * support transparent huge page with MEMORY_DEVICE_PRIVATE but
5861 * this might change.
5863 if (get_mctgt_type_thp(vma
, addr
, *pmd
, NULL
) == MC_TARGET_PAGE
)
5864 mc
.precharge
+= HPAGE_PMD_NR
;
5869 if (pmd_trans_unstable(pmd
))
5871 pte
= pte_offset_map_lock(vma
->vm_mm
, pmd
, addr
, &ptl
);
5872 for (; addr
!= end
; pte
++, addr
+= PAGE_SIZE
)
5873 if (get_mctgt_type(vma
, addr
, *pte
, NULL
))
5874 mc
.precharge
++; /* increment precharge temporarily */
5875 pte_unmap_unlock(pte
- 1, ptl
);
5881 static const struct mm_walk_ops precharge_walk_ops
= {
5882 .pmd_entry
= mem_cgroup_count_precharge_pte_range
,
5885 static unsigned long mem_cgroup_count_precharge(struct mm_struct
*mm
)
5887 unsigned long precharge
;
5890 walk_page_range(mm
, 0, mm
->highest_vm_end
, &precharge_walk_ops
, NULL
);
5891 mmap_read_unlock(mm
);
5893 precharge
= mc
.precharge
;
5899 static int mem_cgroup_precharge_mc(struct mm_struct
*mm
)
5901 unsigned long precharge
= mem_cgroup_count_precharge(mm
);
5903 VM_BUG_ON(mc
.moving_task
);
5904 mc
.moving_task
= current
;
5905 return mem_cgroup_do_precharge(precharge
);
5908 /* cancels all extra charges on mc.from and mc.to, and wakes up all waiters. */
5909 static void __mem_cgroup_clear_mc(void)
5911 struct mem_cgroup
*from
= mc
.from
;
5912 struct mem_cgroup
*to
= mc
.to
;
5914 /* we must uncharge all the leftover precharges from mc.to */
5916 cancel_charge(mc
.to
, mc
.precharge
);
5920 * we didn't uncharge from mc.from at mem_cgroup_move_account(), so
5921 * we must uncharge here.
5923 if (mc
.moved_charge
) {
5924 cancel_charge(mc
.from
, mc
.moved_charge
);
5925 mc
.moved_charge
= 0;
5927 /* we must fixup refcnts and charges */
5928 if (mc
.moved_swap
) {
5929 /* uncharge swap account from the old cgroup */
5930 if (!mem_cgroup_is_root(mc
.from
))
5931 page_counter_uncharge(&mc
.from
->memsw
, mc
.moved_swap
);
5933 mem_cgroup_id_put_many(mc
.from
, mc
.moved_swap
);
5936 * we charged both to->memory and to->memsw, so we
5937 * should uncharge to->memory.
5939 if (!mem_cgroup_is_root(mc
.to
))
5940 page_counter_uncharge(&mc
.to
->memory
, mc
.moved_swap
);
5944 memcg_oom_recover(from
);
5945 memcg_oom_recover(to
);
5946 wake_up_all(&mc
.waitq
);
5949 static void mem_cgroup_clear_mc(void)
5951 struct mm_struct
*mm
= mc
.mm
;
5954 * we must clear moving_task before waking up waiters at the end of
5957 mc
.moving_task
= NULL
;
5958 __mem_cgroup_clear_mc();
5959 spin_lock(&mc
.lock
);
5963 spin_unlock(&mc
.lock
);
5968 static int mem_cgroup_can_attach(struct cgroup_taskset
*tset
)
5970 struct cgroup_subsys_state
*css
;
5971 struct mem_cgroup
*memcg
= NULL
; /* unneeded init to make gcc happy */
5972 struct mem_cgroup
*from
;
5973 struct task_struct
*leader
, *p
;
5974 struct mm_struct
*mm
;
5975 unsigned long move_flags
;
5978 /* charge immigration isn't supported on the default hierarchy */
5979 if (cgroup_subsys_on_dfl(memory_cgrp_subsys
))
5983 * Multi-process migrations only happen on the default hierarchy
5984 * where charge immigration is not used. Perform charge
5985 * immigration if @tset contains a leader and whine if there are
5989 cgroup_taskset_for_each_leader(leader
, css
, tset
) {
5992 memcg
= mem_cgroup_from_css(css
);
5998 * We are now commited to this value whatever it is. Changes in this
5999 * tunable will only affect upcoming migrations, not the current one.
6000 * So we need to save it, and keep it going.
6002 move_flags
= READ_ONCE(memcg
->move_charge_at_immigrate
);
6006 from
= mem_cgroup_from_task(p
);
6008 VM_BUG_ON(from
== memcg
);
6010 mm
= get_task_mm(p
);
6013 /* We move charges only when we move a owner of the mm */
6014 if (mm
->owner
== p
) {
6017 VM_BUG_ON(mc
.precharge
);
6018 VM_BUG_ON(mc
.moved_charge
);
6019 VM_BUG_ON(mc
.moved_swap
);
6021 spin_lock(&mc
.lock
);
6025 mc
.flags
= move_flags
;
6026 spin_unlock(&mc
.lock
);
6027 /* We set mc.moving_task later */
6029 ret
= mem_cgroup_precharge_mc(mm
);
6031 mem_cgroup_clear_mc();
6038 static void mem_cgroup_cancel_attach(struct cgroup_taskset
*tset
)
6041 mem_cgroup_clear_mc();
6044 static int mem_cgroup_move_charge_pte_range(pmd_t
*pmd
,
6045 unsigned long addr
, unsigned long end
,
6046 struct mm_walk
*walk
)
6049 struct vm_area_struct
*vma
= walk
->vma
;
6052 enum mc_target_type target_type
;
6053 union mc_target target
;
6056 ptl
= pmd_trans_huge_lock(pmd
, vma
);
6058 if (mc
.precharge
< HPAGE_PMD_NR
) {
6062 target_type
= get_mctgt_type_thp(vma
, addr
, *pmd
, &target
);
6063 if (target_type
== MC_TARGET_PAGE
) {
6065 if (!isolate_lru_page(page
)) {
6066 if (!mem_cgroup_move_account(page
, true,
6068 mc
.precharge
-= HPAGE_PMD_NR
;
6069 mc
.moved_charge
+= HPAGE_PMD_NR
;
6071 putback_lru_page(page
);
6074 } else if (target_type
== MC_TARGET_DEVICE
) {
6076 if (!mem_cgroup_move_account(page
, true,
6078 mc
.precharge
-= HPAGE_PMD_NR
;
6079 mc
.moved_charge
+= HPAGE_PMD_NR
;
6087 if (pmd_trans_unstable(pmd
))
6090 pte
= pte_offset_map_lock(vma
->vm_mm
, pmd
, addr
, &ptl
);
6091 for (; addr
!= end
; addr
+= PAGE_SIZE
) {
6092 pte_t ptent
= *(pte
++);
6093 bool device
= false;
6099 switch (get_mctgt_type(vma
, addr
, ptent
, &target
)) {
6100 case MC_TARGET_DEVICE
:
6103 case MC_TARGET_PAGE
:
6106 * We can have a part of the split pmd here. Moving it
6107 * can be done but it would be too convoluted so simply
6108 * ignore such a partial THP and keep it in original
6109 * memcg. There should be somebody mapping the head.
6111 if (PageTransCompound(page
))
6113 if (!device
&& isolate_lru_page(page
))
6115 if (!mem_cgroup_move_account(page
, false,
6118 /* we uncharge from mc.from later. */
6122 putback_lru_page(page
);
6123 put
: /* get_mctgt_type() gets the page */
6126 case MC_TARGET_SWAP
:
6128 if (!mem_cgroup_move_swap_account(ent
, mc
.from
, mc
.to
)) {
6130 mem_cgroup_id_get_many(mc
.to
, 1);
6131 /* we fixup other refcnts and charges later. */
6139 pte_unmap_unlock(pte
- 1, ptl
);
6144 * We have consumed all precharges we got in can_attach().
6145 * We try charge one by one, but don't do any additional
6146 * charges to mc.to if we have failed in charge once in attach()
6149 ret
= mem_cgroup_do_precharge(1);
6157 static const struct mm_walk_ops charge_walk_ops
= {
6158 .pmd_entry
= mem_cgroup_move_charge_pte_range
,
6161 static void mem_cgroup_move_charge(void)
6163 lru_add_drain_all();
6165 * Signal lock_page_memcg() to take the memcg's move_lock
6166 * while we're moving its pages to another memcg. Then wait
6167 * for already started RCU-only updates to finish.
6169 atomic_inc(&mc
.from
->moving_account
);
6172 if (unlikely(!mmap_read_trylock(mc
.mm
))) {
6174 * Someone who are holding the mmap_lock might be waiting in
6175 * waitq. So we cancel all extra charges, wake up all waiters,
6176 * and retry. Because we cancel precharges, we might not be able
6177 * to move enough charges, but moving charge is a best-effort
6178 * feature anyway, so it wouldn't be a big problem.
6180 __mem_cgroup_clear_mc();
6185 * When we have consumed all precharges and failed in doing
6186 * additional charge, the page walk just aborts.
6188 walk_page_range(mc
.mm
, 0, mc
.mm
->highest_vm_end
, &charge_walk_ops
,
6191 mmap_read_unlock(mc
.mm
);
6192 atomic_dec(&mc
.from
->moving_account
);
6195 static void mem_cgroup_move_task(void)
6198 mem_cgroup_move_charge();
6199 mem_cgroup_clear_mc();
6202 #else /* !CONFIG_MMU */
6203 static int mem_cgroup_can_attach(struct cgroup_taskset
*tset
)
6207 static void mem_cgroup_cancel_attach(struct cgroup_taskset
*tset
)
6210 static void mem_cgroup_move_task(void)
6216 * Cgroup retains root cgroups across [un]mount cycles making it necessary
6217 * to verify whether we're attached to the default hierarchy on each mount
6220 static void mem_cgroup_bind(struct cgroup_subsys_state
*root_css
)
6223 * use_hierarchy is forced on the default hierarchy. cgroup core
6224 * guarantees that @root doesn't have any children, so turning it
6225 * on for the root memcg is enough.
6227 if (cgroup_subsys_on_dfl(memory_cgrp_subsys
))
6228 root_mem_cgroup
->use_hierarchy
= true;
6230 root_mem_cgroup
->use_hierarchy
= false;
6233 static int seq_puts_memcg_tunable(struct seq_file
*m
, unsigned long value
)
6235 if (value
== PAGE_COUNTER_MAX
)
6236 seq_puts(m
, "max\n");
6238 seq_printf(m
, "%llu\n", (u64
)value
* PAGE_SIZE
);
6243 static u64
memory_current_read(struct cgroup_subsys_state
*css
,
6246 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
6248 return (u64
)page_counter_read(&memcg
->memory
) * PAGE_SIZE
;
6251 static int memory_min_show(struct seq_file
*m
, void *v
)
6253 return seq_puts_memcg_tunable(m
,
6254 READ_ONCE(mem_cgroup_from_seq(m
)->memory
.min
));
6257 static ssize_t
memory_min_write(struct kernfs_open_file
*of
,
6258 char *buf
, size_t nbytes
, loff_t off
)
6260 struct mem_cgroup
*memcg
= mem_cgroup_from_css(of_css(of
));
6264 buf
= strstrip(buf
);
6265 err
= page_counter_memparse(buf
, "max", &min
);
6269 page_counter_set_min(&memcg
->memory
, min
);
6274 static int memory_low_show(struct seq_file
*m
, void *v
)
6276 return seq_puts_memcg_tunable(m
,
6277 READ_ONCE(mem_cgroup_from_seq(m
)->memory
.low
));
6280 static ssize_t
memory_low_write(struct kernfs_open_file
*of
,
6281 char *buf
, size_t nbytes
, loff_t off
)
6283 struct mem_cgroup
*memcg
= mem_cgroup_from_css(of_css(of
));
6287 buf
= strstrip(buf
);
6288 err
= page_counter_memparse(buf
, "max", &low
);
6292 page_counter_set_low(&memcg
->memory
, low
);
6297 static int memory_high_show(struct seq_file
*m
, void *v
)
6299 return seq_puts_memcg_tunable(m
,
6300 READ_ONCE(mem_cgroup_from_seq(m
)->memory
.high
));
6303 static ssize_t
memory_high_write(struct kernfs_open_file
*of
,
6304 char *buf
, size_t nbytes
, loff_t off
)
6306 struct mem_cgroup
*memcg
= mem_cgroup_from_css(of_css(of
));
6307 unsigned int nr_retries
= MAX_RECLAIM_RETRIES
;
6308 bool drained
= false;
6312 buf
= strstrip(buf
);
6313 err
= page_counter_memparse(buf
, "max", &high
);
6318 unsigned long nr_pages
= page_counter_read(&memcg
->memory
);
6319 unsigned long reclaimed
;
6321 if (nr_pages
<= high
)
6324 if (signal_pending(current
))
6328 drain_all_stock(memcg
);
6333 reclaimed
= try_to_free_mem_cgroup_pages(memcg
, nr_pages
- high
,
6336 if (!reclaimed
&& !nr_retries
--)
6340 page_counter_set_high(&memcg
->memory
, high
);
6342 memcg_wb_domain_size_changed(memcg
);
6347 static int memory_max_show(struct seq_file
*m
, void *v
)
6349 return seq_puts_memcg_tunable(m
,
6350 READ_ONCE(mem_cgroup_from_seq(m
)->memory
.max
));
6353 static ssize_t
memory_max_write(struct kernfs_open_file
*of
,
6354 char *buf
, size_t nbytes
, loff_t off
)
6356 struct mem_cgroup
*memcg
= mem_cgroup_from_css(of_css(of
));
6357 unsigned int nr_reclaims
= MAX_RECLAIM_RETRIES
;
6358 bool drained
= false;
6362 buf
= strstrip(buf
);
6363 err
= page_counter_memparse(buf
, "max", &max
);
6367 xchg(&memcg
->memory
.max
, max
);
6370 unsigned long nr_pages
= page_counter_read(&memcg
->memory
);
6372 if (nr_pages
<= max
)
6375 if (signal_pending(current
))
6379 drain_all_stock(memcg
);
6385 if (!try_to_free_mem_cgroup_pages(memcg
, nr_pages
- max
,
6391 memcg_memory_event(memcg
, MEMCG_OOM
);
6392 if (!mem_cgroup_out_of_memory(memcg
, GFP_KERNEL
, 0))
6396 memcg_wb_domain_size_changed(memcg
);
6400 static void __memory_events_show(struct seq_file
*m
, atomic_long_t
*events
)
6402 seq_printf(m
, "low %lu\n", atomic_long_read(&events
[MEMCG_LOW
]));
6403 seq_printf(m
, "high %lu\n", atomic_long_read(&events
[MEMCG_HIGH
]));
6404 seq_printf(m
, "max %lu\n", atomic_long_read(&events
[MEMCG_MAX
]));
6405 seq_printf(m
, "oom %lu\n", atomic_long_read(&events
[MEMCG_OOM
]));
6406 seq_printf(m
, "oom_kill %lu\n",
6407 atomic_long_read(&events
[MEMCG_OOM_KILL
]));
6410 static int memory_events_show(struct seq_file
*m
, void *v
)
6412 struct mem_cgroup
*memcg
= mem_cgroup_from_seq(m
);
6414 __memory_events_show(m
, memcg
->memory_events
);
6418 static int memory_events_local_show(struct seq_file
*m
, void *v
)
6420 struct mem_cgroup
*memcg
= mem_cgroup_from_seq(m
);
6422 __memory_events_show(m
, memcg
->memory_events_local
);
6426 static int memory_stat_show(struct seq_file
*m
, void *v
)
6428 struct mem_cgroup
*memcg
= mem_cgroup_from_seq(m
);
6431 buf
= memory_stat_format(memcg
);
6440 static int memory_numa_stat_show(struct seq_file
*m
, void *v
)
6443 struct mem_cgroup
*memcg
= mem_cgroup_from_seq(m
);
6445 for (i
= 0; i
< ARRAY_SIZE(memory_stats
); i
++) {
6448 if (memory_stats
[i
].idx
>= NR_VM_NODE_STAT_ITEMS
)
6451 seq_printf(m
, "%s", memory_stats
[i
].name
);
6452 for_each_node_state(nid
, N_MEMORY
) {
6454 struct lruvec
*lruvec
;
6456 lruvec
= mem_cgroup_lruvec(memcg
, NODE_DATA(nid
));
6457 size
= lruvec_page_state(lruvec
, memory_stats
[i
].idx
);
6458 size
*= memory_stats
[i
].ratio
;
6459 seq_printf(m
, " N%d=%llu", nid
, size
);
6468 static int memory_oom_group_show(struct seq_file
*m
, void *v
)
6470 struct mem_cgroup
*memcg
= mem_cgroup_from_seq(m
);
6472 seq_printf(m
, "%d\n", memcg
->oom_group
);
6477 static ssize_t
memory_oom_group_write(struct kernfs_open_file
*of
,
6478 char *buf
, size_t nbytes
, loff_t off
)
6480 struct mem_cgroup
*memcg
= mem_cgroup_from_css(of_css(of
));
6483 buf
= strstrip(buf
);
6487 ret
= kstrtoint(buf
, 0, &oom_group
);
6491 if (oom_group
!= 0 && oom_group
!= 1)
6494 memcg
->oom_group
= oom_group
;
6499 static struct cftype memory_files
[] = {
6502 .flags
= CFTYPE_NOT_ON_ROOT
,
6503 .read_u64
= memory_current_read
,
6507 .flags
= CFTYPE_NOT_ON_ROOT
,
6508 .seq_show
= memory_min_show
,
6509 .write
= memory_min_write
,
6513 .flags
= CFTYPE_NOT_ON_ROOT
,
6514 .seq_show
= memory_low_show
,
6515 .write
= memory_low_write
,
6519 .flags
= CFTYPE_NOT_ON_ROOT
,
6520 .seq_show
= memory_high_show
,
6521 .write
= memory_high_write
,
6525 .flags
= CFTYPE_NOT_ON_ROOT
,
6526 .seq_show
= memory_max_show
,
6527 .write
= memory_max_write
,
6531 .flags
= CFTYPE_NOT_ON_ROOT
,
6532 .file_offset
= offsetof(struct mem_cgroup
, events_file
),
6533 .seq_show
= memory_events_show
,
6536 .name
= "events.local",
6537 .flags
= CFTYPE_NOT_ON_ROOT
,
6538 .file_offset
= offsetof(struct mem_cgroup
, events_local_file
),
6539 .seq_show
= memory_events_local_show
,
6543 .seq_show
= memory_stat_show
,
6547 .name
= "numa_stat",
6548 .seq_show
= memory_numa_stat_show
,
6552 .name
= "oom.group",
6553 .flags
= CFTYPE_NOT_ON_ROOT
| CFTYPE_NS_DELEGATABLE
,
6554 .seq_show
= memory_oom_group_show
,
6555 .write
= memory_oom_group_write
,
6560 struct cgroup_subsys memory_cgrp_subsys
= {
6561 .css_alloc
= mem_cgroup_css_alloc
,
6562 .css_online
= mem_cgroup_css_online
,
6563 .css_offline
= mem_cgroup_css_offline
,
6564 .css_released
= mem_cgroup_css_released
,
6565 .css_free
= mem_cgroup_css_free
,
6566 .css_reset
= mem_cgroup_css_reset
,
6567 .can_attach
= mem_cgroup_can_attach
,
6568 .cancel_attach
= mem_cgroup_cancel_attach
,
6569 .post_attach
= mem_cgroup_move_task
,
6570 .bind
= mem_cgroup_bind
,
6571 .dfl_cftypes
= memory_files
,
6572 .legacy_cftypes
= mem_cgroup_legacy_files
,
6577 * This function calculates an individual cgroup's effective
6578 * protection which is derived from its own memory.min/low, its
6579 * parent's and siblings' settings, as well as the actual memory
6580 * distribution in the tree.
6582 * The following rules apply to the effective protection values:
6584 * 1. At the first level of reclaim, effective protection is equal to
6585 * the declared protection in memory.min and memory.low.
6587 * 2. To enable safe delegation of the protection configuration, at
6588 * subsequent levels the effective protection is capped to the
6589 * parent's effective protection.
6591 * 3. To make complex and dynamic subtrees easier to configure, the
6592 * user is allowed to overcommit the declared protection at a given
6593 * level. If that is the case, the parent's effective protection is
6594 * distributed to the children in proportion to how much protection
6595 * they have declared and how much of it they are utilizing.
6597 * This makes distribution proportional, but also work-conserving:
6598 * if one cgroup claims much more protection than it uses memory,
6599 * the unused remainder is available to its siblings.
6601 * 4. Conversely, when the declared protection is undercommitted at a
6602 * given level, the distribution of the larger parental protection
6603 * budget is NOT proportional. A cgroup's protection from a sibling
6604 * is capped to its own memory.min/low setting.
6606 * 5. However, to allow protecting recursive subtrees from each other
6607 * without having to declare each individual cgroup's fixed share
6608 * of the ancestor's claim to protection, any unutilized -
6609 * "floating" - protection from up the tree is distributed in
6610 * proportion to each cgroup's *usage*. This makes the protection
6611 * neutral wrt sibling cgroups and lets them compete freely over
6612 * the shared parental protection budget, but it protects the
6613 * subtree as a whole from neighboring subtrees.
6615 * Note that 4. and 5. are not in conflict: 4. is about protecting
6616 * against immediate siblings whereas 5. is about protecting against
6617 * neighboring subtrees.
6619 static unsigned long effective_protection(unsigned long usage
,
6620 unsigned long parent_usage
,
6621 unsigned long setting
,
6622 unsigned long parent_effective
,
6623 unsigned long siblings_protected
)
6625 unsigned long protected;
6628 protected = min(usage
, setting
);
6630 * If all cgroups at this level combined claim and use more
6631 * protection then what the parent affords them, distribute
6632 * shares in proportion to utilization.
6634 * We are using actual utilization rather than the statically
6635 * claimed protection in order to be work-conserving: claimed
6636 * but unused protection is available to siblings that would
6637 * otherwise get a smaller chunk than what they claimed.
6639 if (siblings_protected
> parent_effective
)
6640 return protected * parent_effective
/ siblings_protected
;
6643 * Ok, utilized protection of all children is within what the
6644 * parent affords them, so we know whatever this child claims
6645 * and utilizes is effectively protected.
6647 * If there is unprotected usage beyond this value, reclaim
6648 * will apply pressure in proportion to that amount.
6650 * If there is unutilized protection, the cgroup will be fully
6651 * shielded from reclaim, but we do return a smaller value for
6652 * protection than what the group could enjoy in theory. This
6653 * is okay. With the overcommit distribution above, effective
6654 * protection is always dependent on how memory is actually
6655 * consumed among the siblings anyway.
6660 * If the children aren't claiming (all of) the protection
6661 * afforded to them by the parent, distribute the remainder in
6662 * proportion to the (unprotected) memory of each cgroup. That
6663 * way, cgroups that aren't explicitly prioritized wrt each
6664 * other compete freely over the allowance, but they are
6665 * collectively protected from neighboring trees.
6667 * We're using unprotected memory for the weight so that if
6668 * some cgroups DO claim explicit protection, we don't protect
6669 * the same bytes twice.
6671 * Check both usage and parent_usage against the respective
6672 * protected values. One should imply the other, but they
6673 * aren't read atomically - make sure the division is sane.
6675 if (!(cgrp_dfl_root
.flags
& CGRP_ROOT_MEMORY_RECURSIVE_PROT
))
6677 if (parent_effective
> siblings_protected
&&
6678 parent_usage
> siblings_protected
&&
6679 usage
> protected) {
6680 unsigned long unclaimed
;
6682 unclaimed
= parent_effective
- siblings_protected
;
6683 unclaimed
*= usage
- protected;
6684 unclaimed
/= parent_usage
- siblings_protected
;
6693 * mem_cgroup_protected - check if memory consumption is in the normal range
6694 * @root: the top ancestor of the sub-tree being checked
6695 * @memcg: the memory cgroup to check
6697 * WARNING: This function is not stateless! It can only be used as part
6698 * of a top-down tree iteration, not for isolated queries.
6700 void mem_cgroup_calculate_protection(struct mem_cgroup
*root
,
6701 struct mem_cgroup
*memcg
)
6703 unsigned long usage
, parent_usage
;
6704 struct mem_cgroup
*parent
;
6706 if (mem_cgroup_disabled())
6710 root
= root_mem_cgroup
;
6713 * Effective values of the reclaim targets are ignored so they
6714 * can be stale. Have a look at mem_cgroup_protection for more
6716 * TODO: calculation should be more robust so that we do not need
6717 * that special casing.
6722 usage
= page_counter_read(&memcg
->memory
);
6726 parent
= parent_mem_cgroup(memcg
);
6727 /* No parent means a non-hierarchical mode on v1 memcg */
6731 if (parent
== root
) {
6732 memcg
->memory
.emin
= READ_ONCE(memcg
->memory
.min
);
6733 memcg
->memory
.elow
= READ_ONCE(memcg
->memory
.low
);
6737 parent_usage
= page_counter_read(&parent
->memory
);
6739 WRITE_ONCE(memcg
->memory
.emin
, effective_protection(usage
, parent_usage
,
6740 READ_ONCE(memcg
->memory
.min
),
6741 READ_ONCE(parent
->memory
.emin
),
6742 atomic_long_read(&parent
->memory
.children_min_usage
)));
6744 WRITE_ONCE(memcg
->memory
.elow
, effective_protection(usage
, parent_usage
,
6745 READ_ONCE(memcg
->memory
.low
),
6746 READ_ONCE(parent
->memory
.elow
),
6747 atomic_long_read(&parent
->memory
.children_low_usage
)));
6751 * mem_cgroup_charge - charge a newly allocated page to a cgroup
6752 * @page: page to charge
6753 * @mm: mm context of the victim
6754 * @gfp_mask: reclaim mode
6756 * Try to charge @page to the memcg that @mm belongs to, reclaiming
6757 * pages according to @gfp_mask if necessary.
6759 * Returns 0 on success. Otherwise, an error code is returned.
6761 int mem_cgroup_charge(struct page
*page
, struct mm_struct
*mm
, gfp_t gfp_mask
)
6763 unsigned int nr_pages
= thp_nr_pages(page
);
6764 struct mem_cgroup
*memcg
= NULL
;
6767 if (mem_cgroup_disabled())
6770 if (PageSwapCache(page
)) {
6771 swp_entry_t ent
= { .val
= page_private(page
), };
6775 * Every swap fault against a single page tries to charge the
6776 * page, bail as early as possible. shmem_unuse() encounters
6777 * already charged pages, too. page->mem_cgroup is protected
6778 * by the page lock, which serializes swap cache removal, which
6779 * in turn serializes uncharging.
6781 VM_BUG_ON_PAGE(!PageLocked(page
), page
);
6782 if (compound_head(page
)->mem_cgroup
)
6785 id
= lookup_swap_cgroup_id(ent
);
6787 memcg
= mem_cgroup_from_id(id
);
6788 if (memcg
&& !css_tryget_online(&memcg
->css
))
6794 memcg
= get_mem_cgroup_from_mm(mm
);
6796 ret
= try_charge(memcg
, gfp_mask
, nr_pages
);
6800 css_get(&memcg
->css
);
6801 commit_charge(page
, memcg
);
6803 local_irq_disable();
6804 mem_cgroup_charge_statistics(memcg
, page
, nr_pages
);
6805 memcg_check_events(memcg
, page
);
6808 if (PageSwapCache(page
)) {
6809 swp_entry_t entry
= { .val
= page_private(page
) };
6811 * The swap entry might not get freed for a long time,
6812 * let's not wait for it. The page already received a
6813 * memory+swap charge, drop the swap entry duplicate.
6815 mem_cgroup_uncharge_swap(entry
, nr_pages
);
6819 css_put(&memcg
->css
);
6824 struct uncharge_gather
{
6825 struct mem_cgroup
*memcg
;
6826 unsigned long nr_pages
;
6827 unsigned long pgpgout
;
6828 unsigned long nr_kmem
;
6829 struct page
*dummy_page
;
6832 static inline void uncharge_gather_clear(struct uncharge_gather
*ug
)
6834 memset(ug
, 0, sizeof(*ug
));
6837 static void uncharge_batch(const struct uncharge_gather
*ug
)
6839 unsigned long flags
;
6841 if (!mem_cgroup_is_root(ug
->memcg
)) {
6842 page_counter_uncharge(&ug
->memcg
->memory
, ug
->nr_pages
);
6843 if (do_memsw_account())
6844 page_counter_uncharge(&ug
->memcg
->memsw
, ug
->nr_pages
);
6845 if (!cgroup_subsys_on_dfl(memory_cgrp_subsys
) && ug
->nr_kmem
)
6846 page_counter_uncharge(&ug
->memcg
->kmem
, ug
->nr_kmem
);
6847 memcg_oom_recover(ug
->memcg
);
6850 local_irq_save(flags
);
6851 __count_memcg_events(ug
->memcg
, PGPGOUT
, ug
->pgpgout
);
6852 __this_cpu_add(ug
->memcg
->vmstats_percpu
->nr_page_events
, ug
->nr_pages
);
6853 memcg_check_events(ug
->memcg
, ug
->dummy_page
);
6854 local_irq_restore(flags
);
6856 /* drop reference from uncharge_page */
6857 css_put(&ug
->memcg
->css
);
6860 static void uncharge_page(struct page
*page
, struct uncharge_gather
*ug
)
6862 unsigned long nr_pages
;
6864 VM_BUG_ON_PAGE(PageLRU(page
), page
);
6866 if (!page
->mem_cgroup
)
6870 * Nobody should be changing or seriously looking at
6871 * page->mem_cgroup at this point, we have fully
6872 * exclusive access to the page.
6875 if (ug
->memcg
!= page
->mem_cgroup
) {
6878 uncharge_gather_clear(ug
);
6880 ug
->memcg
= page
->mem_cgroup
;
6882 /* pairs with css_put in uncharge_batch */
6883 css_get(&ug
->memcg
->css
);
6886 nr_pages
= compound_nr(page
);
6887 ug
->nr_pages
+= nr_pages
;
6889 if (!PageKmemcg(page
)) {
6892 ug
->nr_kmem
+= nr_pages
;
6893 __ClearPageKmemcg(page
);
6896 ug
->dummy_page
= page
;
6897 page
->mem_cgroup
= NULL
;
6898 css_put(&ug
->memcg
->css
);
6901 static void uncharge_list(struct list_head
*page_list
)
6903 struct uncharge_gather ug
;
6904 struct list_head
*next
;
6906 uncharge_gather_clear(&ug
);
6909 * Note that the list can be a single page->lru; hence the
6910 * do-while loop instead of a simple list_for_each_entry().
6912 next
= page_list
->next
;
6916 page
= list_entry(next
, struct page
, lru
);
6917 next
= page
->lru
.next
;
6919 uncharge_page(page
, &ug
);
6920 } while (next
!= page_list
);
6923 uncharge_batch(&ug
);
6927 * mem_cgroup_uncharge - uncharge a page
6928 * @page: page to uncharge
6930 * Uncharge a page previously charged with mem_cgroup_charge().
6932 void mem_cgroup_uncharge(struct page
*page
)
6934 struct uncharge_gather ug
;
6936 if (mem_cgroup_disabled())
6939 /* Don't touch page->lru of any random page, pre-check: */
6940 if (!page
->mem_cgroup
)
6943 uncharge_gather_clear(&ug
);
6944 uncharge_page(page
, &ug
);
6945 uncharge_batch(&ug
);
6949 * mem_cgroup_uncharge_list - uncharge a list of page
6950 * @page_list: list of pages to uncharge
6952 * Uncharge a list of pages previously charged with
6953 * mem_cgroup_charge().
6955 void mem_cgroup_uncharge_list(struct list_head
*page_list
)
6957 if (mem_cgroup_disabled())
6960 if (!list_empty(page_list
))
6961 uncharge_list(page_list
);
6965 * mem_cgroup_migrate - charge a page's replacement
6966 * @oldpage: currently circulating page
6967 * @newpage: replacement page
6969 * Charge @newpage as a replacement page for @oldpage. @oldpage will
6970 * be uncharged upon free.
6972 * Both pages must be locked, @newpage->mapping must be set up.
6974 void mem_cgroup_migrate(struct page
*oldpage
, struct page
*newpage
)
6976 struct mem_cgroup
*memcg
;
6977 unsigned int nr_pages
;
6978 unsigned long flags
;
6980 VM_BUG_ON_PAGE(!PageLocked(oldpage
), oldpage
);
6981 VM_BUG_ON_PAGE(!PageLocked(newpage
), newpage
);
6982 VM_BUG_ON_PAGE(PageAnon(oldpage
) != PageAnon(newpage
), newpage
);
6983 VM_BUG_ON_PAGE(PageTransHuge(oldpage
) != PageTransHuge(newpage
),
6986 if (mem_cgroup_disabled())
6989 /* Page cache replacement: new page already charged? */
6990 if (newpage
->mem_cgroup
)
6993 /* Swapcache readahead pages can get replaced before being charged */
6994 memcg
= oldpage
->mem_cgroup
;
6998 /* Force-charge the new page. The old one will be freed soon */
6999 nr_pages
= thp_nr_pages(newpage
);
7001 page_counter_charge(&memcg
->memory
, nr_pages
);
7002 if (do_memsw_account())
7003 page_counter_charge(&memcg
->memsw
, nr_pages
);
7005 css_get(&memcg
->css
);
7006 commit_charge(newpage
, memcg
);
7008 local_irq_save(flags
);
7009 mem_cgroup_charge_statistics(memcg
, newpage
, nr_pages
);
7010 memcg_check_events(memcg
, newpage
);
7011 local_irq_restore(flags
);
7014 DEFINE_STATIC_KEY_FALSE(memcg_sockets_enabled_key
);
7015 EXPORT_SYMBOL(memcg_sockets_enabled_key
);
7017 void mem_cgroup_sk_alloc(struct sock
*sk
)
7019 struct mem_cgroup
*memcg
;
7021 if (!mem_cgroup_sockets_enabled
)
7024 /* Do not associate the sock with unrelated interrupted task's memcg. */
7029 memcg
= mem_cgroup_from_task(current
);
7030 if (memcg
== root_mem_cgroup
)
7032 if (!cgroup_subsys_on_dfl(memory_cgrp_subsys
) && !memcg
->tcpmem_active
)
7034 if (css_tryget(&memcg
->css
))
7035 sk
->sk_memcg
= memcg
;
7040 void mem_cgroup_sk_free(struct sock
*sk
)
7043 css_put(&sk
->sk_memcg
->css
);
7047 * mem_cgroup_charge_skmem - charge socket memory
7048 * @memcg: memcg to charge
7049 * @nr_pages: number of pages to charge
7051 * Charges @nr_pages to @memcg. Returns %true if the charge fit within
7052 * @memcg's configured limit, %false if the charge had to be forced.
7054 bool mem_cgroup_charge_skmem(struct mem_cgroup
*memcg
, unsigned int nr_pages
)
7056 gfp_t gfp_mask
= GFP_KERNEL
;
7058 if (!cgroup_subsys_on_dfl(memory_cgrp_subsys
)) {
7059 struct page_counter
*fail
;
7061 if (page_counter_try_charge(&memcg
->tcpmem
, nr_pages
, &fail
)) {
7062 memcg
->tcpmem_pressure
= 0;
7065 page_counter_charge(&memcg
->tcpmem
, nr_pages
);
7066 memcg
->tcpmem_pressure
= 1;
7070 /* Don't block in the packet receive path */
7072 gfp_mask
= GFP_NOWAIT
;
7074 mod_memcg_state(memcg
, MEMCG_SOCK
, nr_pages
);
7076 if (try_charge(memcg
, gfp_mask
, nr_pages
) == 0)
7079 try_charge(memcg
, gfp_mask
|__GFP_NOFAIL
, nr_pages
);
7084 * mem_cgroup_uncharge_skmem - uncharge socket memory
7085 * @memcg: memcg to uncharge
7086 * @nr_pages: number of pages to uncharge
7088 void mem_cgroup_uncharge_skmem(struct mem_cgroup
*memcg
, unsigned int nr_pages
)
7090 if (!cgroup_subsys_on_dfl(memory_cgrp_subsys
)) {
7091 page_counter_uncharge(&memcg
->tcpmem
, nr_pages
);
7095 mod_memcg_state(memcg
, MEMCG_SOCK
, -nr_pages
);
7097 refill_stock(memcg
, nr_pages
);
7100 static int __init
cgroup_memory(char *s
)
7104 while ((token
= strsep(&s
, ",")) != NULL
) {
7107 if (!strcmp(token
, "nosocket"))
7108 cgroup_memory_nosocket
= true;
7109 if (!strcmp(token
, "nokmem"))
7110 cgroup_memory_nokmem
= true;
7114 __setup("cgroup.memory=", cgroup_memory
);
7117 * subsys_initcall() for memory controller.
7119 * Some parts like memcg_hotplug_cpu_dead() have to be initialized from this
7120 * context because of lock dependencies (cgroup_lock -> cpu hotplug) but
7121 * basically everything that doesn't depend on a specific mem_cgroup structure
7122 * should be initialized from here.
7124 static int __init
mem_cgroup_init(void)
7128 cpuhp_setup_state_nocalls(CPUHP_MM_MEMCQ_DEAD
, "mm/memctrl:dead", NULL
,
7129 memcg_hotplug_cpu_dead
);
7131 for_each_possible_cpu(cpu
)
7132 INIT_WORK(&per_cpu_ptr(&memcg_stock
, cpu
)->work
,
7135 for_each_node(node
) {
7136 struct mem_cgroup_tree_per_node
*rtpn
;
7138 rtpn
= kzalloc_node(sizeof(*rtpn
), GFP_KERNEL
,
7139 node_online(node
) ? node
: NUMA_NO_NODE
);
7141 rtpn
->rb_root
= RB_ROOT
;
7142 rtpn
->rb_rightmost
= NULL
;
7143 spin_lock_init(&rtpn
->lock
);
7144 soft_limit_tree
.rb_tree_per_node
[node
] = rtpn
;
7149 subsys_initcall(mem_cgroup_init
);
7151 #ifdef CONFIG_MEMCG_SWAP
7152 static struct mem_cgroup
*mem_cgroup_id_get_online(struct mem_cgroup
*memcg
)
7154 while (!refcount_inc_not_zero(&memcg
->id
.ref
)) {
7156 * The root cgroup cannot be destroyed, so it's refcount must
7159 if (WARN_ON_ONCE(memcg
== root_mem_cgroup
)) {
7163 memcg
= parent_mem_cgroup(memcg
);
7165 memcg
= root_mem_cgroup
;
7171 * mem_cgroup_swapout - transfer a memsw charge to swap
7172 * @page: page whose memsw charge to transfer
7173 * @entry: swap entry to move the charge to
7175 * Transfer the memsw charge of @page to @entry.
7177 void mem_cgroup_swapout(struct page
*page
, swp_entry_t entry
)
7179 struct mem_cgroup
*memcg
, *swap_memcg
;
7180 unsigned int nr_entries
;
7181 unsigned short oldid
;
7183 VM_BUG_ON_PAGE(PageLRU(page
), page
);
7184 VM_BUG_ON_PAGE(page_count(page
), page
);
7186 if (cgroup_subsys_on_dfl(memory_cgrp_subsys
))
7189 memcg
= page
->mem_cgroup
;
7191 /* Readahead page, never charged */
7196 * In case the memcg owning these pages has been offlined and doesn't
7197 * have an ID allocated to it anymore, charge the closest online
7198 * ancestor for the swap instead and transfer the memory+swap charge.
7200 swap_memcg
= mem_cgroup_id_get_online(memcg
);
7201 nr_entries
= thp_nr_pages(page
);
7202 /* Get references for the tail pages, too */
7204 mem_cgroup_id_get_many(swap_memcg
, nr_entries
- 1);
7205 oldid
= swap_cgroup_record(entry
, mem_cgroup_id(swap_memcg
),
7207 VM_BUG_ON_PAGE(oldid
, page
);
7208 mod_memcg_state(swap_memcg
, MEMCG_SWAP
, nr_entries
);
7210 page
->mem_cgroup
= NULL
;
7212 if (!mem_cgroup_is_root(memcg
))
7213 page_counter_uncharge(&memcg
->memory
, nr_entries
);
7215 if (!cgroup_memory_noswap
&& memcg
!= swap_memcg
) {
7216 if (!mem_cgroup_is_root(swap_memcg
))
7217 page_counter_charge(&swap_memcg
->memsw
, nr_entries
);
7218 page_counter_uncharge(&memcg
->memsw
, nr_entries
);
7222 * Interrupts should be disabled here because the caller holds the
7223 * i_pages lock which is taken with interrupts-off. It is
7224 * important here to have the interrupts disabled because it is the
7225 * only synchronisation we have for updating the per-CPU variables.
7227 VM_BUG_ON(!irqs_disabled());
7228 mem_cgroup_charge_statistics(memcg
, page
, -nr_entries
);
7229 memcg_check_events(memcg
, page
);
7231 css_put(&memcg
->css
);
7235 * mem_cgroup_try_charge_swap - try charging swap space for a page
7236 * @page: page being added to swap
7237 * @entry: swap entry to charge
7239 * Try to charge @page's memcg for the swap space at @entry.
7241 * Returns 0 on success, -ENOMEM on failure.
7243 int mem_cgroup_try_charge_swap(struct page
*page
, swp_entry_t entry
)
7245 unsigned int nr_pages
= thp_nr_pages(page
);
7246 struct page_counter
*counter
;
7247 struct mem_cgroup
*memcg
;
7248 unsigned short oldid
;
7250 if (!cgroup_subsys_on_dfl(memory_cgrp_subsys
))
7253 memcg
= page
->mem_cgroup
;
7255 /* Readahead page, never charged */
7260 memcg_memory_event(memcg
, MEMCG_SWAP_FAIL
);
7264 memcg
= mem_cgroup_id_get_online(memcg
);
7266 if (!cgroup_memory_noswap
&& !mem_cgroup_is_root(memcg
) &&
7267 !page_counter_try_charge(&memcg
->swap
, nr_pages
, &counter
)) {
7268 memcg_memory_event(memcg
, MEMCG_SWAP_MAX
);
7269 memcg_memory_event(memcg
, MEMCG_SWAP_FAIL
);
7270 mem_cgroup_id_put(memcg
);
7274 /* Get references for the tail pages, too */
7276 mem_cgroup_id_get_many(memcg
, nr_pages
- 1);
7277 oldid
= swap_cgroup_record(entry
, mem_cgroup_id(memcg
), nr_pages
);
7278 VM_BUG_ON_PAGE(oldid
, page
);
7279 mod_memcg_state(memcg
, MEMCG_SWAP
, nr_pages
);
7285 * mem_cgroup_uncharge_swap - uncharge swap space
7286 * @entry: swap entry to uncharge
7287 * @nr_pages: the amount of swap space to uncharge
7289 void mem_cgroup_uncharge_swap(swp_entry_t entry
, unsigned int nr_pages
)
7291 struct mem_cgroup
*memcg
;
7294 id
= swap_cgroup_record(entry
, 0, nr_pages
);
7296 memcg
= mem_cgroup_from_id(id
);
7298 if (!cgroup_memory_noswap
&& !mem_cgroup_is_root(memcg
)) {
7299 if (cgroup_subsys_on_dfl(memory_cgrp_subsys
))
7300 page_counter_uncharge(&memcg
->swap
, nr_pages
);
7302 page_counter_uncharge(&memcg
->memsw
, nr_pages
);
7304 mod_memcg_state(memcg
, MEMCG_SWAP
, -nr_pages
);
7305 mem_cgroup_id_put_many(memcg
, nr_pages
);
7310 long mem_cgroup_get_nr_swap_pages(struct mem_cgroup
*memcg
)
7312 long nr_swap_pages
= get_nr_swap_pages();
7314 if (cgroup_memory_noswap
|| !cgroup_subsys_on_dfl(memory_cgrp_subsys
))
7315 return nr_swap_pages
;
7316 for (; memcg
!= root_mem_cgroup
; memcg
= parent_mem_cgroup(memcg
))
7317 nr_swap_pages
= min_t(long, nr_swap_pages
,
7318 READ_ONCE(memcg
->swap
.max
) -
7319 page_counter_read(&memcg
->swap
));
7320 return nr_swap_pages
;
7323 bool mem_cgroup_swap_full(struct page
*page
)
7325 struct mem_cgroup
*memcg
;
7327 VM_BUG_ON_PAGE(!PageLocked(page
), page
);
7331 if (cgroup_memory_noswap
|| !cgroup_subsys_on_dfl(memory_cgrp_subsys
))
7334 memcg
= page
->mem_cgroup
;
7338 for (; memcg
!= root_mem_cgroup
; memcg
= parent_mem_cgroup(memcg
)) {
7339 unsigned long usage
= page_counter_read(&memcg
->swap
);
7341 if (usage
* 2 >= READ_ONCE(memcg
->swap
.high
) ||
7342 usage
* 2 >= READ_ONCE(memcg
->swap
.max
))
7349 static int __init
setup_swap_account(char *s
)
7351 if (!strcmp(s
, "1"))
7352 cgroup_memory_noswap
= 0;
7353 else if (!strcmp(s
, "0"))
7354 cgroup_memory_noswap
= 1;
7357 __setup("swapaccount=", setup_swap_account
);
7359 static u64
swap_current_read(struct cgroup_subsys_state
*css
,
7362 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
7364 return (u64
)page_counter_read(&memcg
->swap
) * PAGE_SIZE
;
7367 static int swap_high_show(struct seq_file
*m
, void *v
)
7369 return seq_puts_memcg_tunable(m
,
7370 READ_ONCE(mem_cgroup_from_seq(m
)->swap
.high
));
7373 static ssize_t
swap_high_write(struct kernfs_open_file
*of
,
7374 char *buf
, size_t nbytes
, loff_t off
)
7376 struct mem_cgroup
*memcg
= mem_cgroup_from_css(of_css(of
));
7380 buf
= strstrip(buf
);
7381 err
= page_counter_memparse(buf
, "max", &high
);
7385 page_counter_set_high(&memcg
->swap
, high
);
7390 static int swap_max_show(struct seq_file
*m
, void *v
)
7392 return seq_puts_memcg_tunable(m
,
7393 READ_ONCE(mem_cgroup_from_seq(m
)->swap
.max
));
7396 static ssize_t
swap_max_write(struct kernfs_open_file
*of
,
7397 char *buf
, size_t nbytes
, loff_t off
)
7399 struct mem_cgroup
*memcg
= mem_cgroup_from_css(of_css(of
));
7403 buf
= strstrip(buf
);
7404 err
= page_counter_memparse(buf
, "max", &max
);
7408 xchg(&memcg
->swap
.max
, max
);
7413 static int swap_events_show(struct seq_file
*m
, void *v
)
7415 struct mem_cgroup
*memcg
= mem_cgroup_from_seq(m
);
7417 seq_printf(m
, "high %lu\n",
7418 atomic_long_read(&memcg
->memory_events
[MEMCG_SWAP_HIGH
]));
7419 seq_printf(m
, "max %lu\n",
7420 atomic_long_read(&memcg
->memory_events
[MEMCG_SWAP_MAX
]));
7421 seq_printf(m
, "fail %lu\n",
7422 atomic_long_read(&memcg
->memory_events
[MEMCG_SWAP_FAIL
]));
7427 static struct cftype swap_files
[] = {
7429 .name
= "swap.current",
7430 .flags
= CFTYPE_NOT_ON_ROOT
,
7431 .read_u64
= swap_current_read
,
7434 .name
= "swap.high",
7435 .flags
= CFTYPE_NOT_ON_ROOT
,
7436 .seq_show
= swap_high_show
,
7437 .write
= swap_high_write
,
7441 .flags
= CFTYPE_NOT_ON_ROOT
,
7442 .seq_show
= swap_max_show
,
7443 .write
= swap_max_write
,
7446 .name
= "swap.events",
7447 .flags
= CFTYPE_NOT_ON_ROOT
,
7448 .file_offset
= offsetof(struct mem_cgroup
, swap_events_file
),
7449 .seq_show
= swap_events_show
,
7454 static struct cftype memsw_files
[] = {
7456 .name
= "memsw.usage_in_bytes",
7457 .private = MEMFILE_PRIVATE(_MEMSWAP
, RES_USAGE
),
7458 .read_u64
= mem_cgroup_read_u64
,
7461 .name
= "memsw.max_usage_in_bytes",
7462 .private = MEMFILE_PRIVATE(_MEMSWAP
, RES_MAX_USAGE
),
7463 .write
= mem_cgroup_reset
,
7464 .read_u64
= mem_cgroup_read_u64
,
7467 .name
= "memsw.limit_in_bytes",
7468 .private = MEMFILE_PRIVATE(_MEMSWAP
, RES_LIMIT
),
7469 .write
= mem_cgroup_write
,
7470 .read_u64
= mem_cgroup_read_u64
,
7473 .name
= "memsw.failcnt",
7474 .private = MEMFILE_PRIVATE(_MEMSWAP
, RES_FAILCNT
),
7475 .write
= mem_cgroup_reset
,
7476 .read_u64
= mem_cgroup_read_u64
,
7478 { }, /* terminate */
7482 * If mem_cgroup_swap_init() is implemented as a subsys_initcall()
7483 * instead of a core_initcall(), this could mean cgroup_memory_noswap still
7484 * remains set to false even when memcg is disabled via "cgroup_disable=memory"
7485 * boot parameter. This may result in premature OOPS inside
7486 * mem_cgroup_get_nr_swap_pages() function in corner cases.
7488 static int __init
mem_cgroup_swap_init(void)
7490 /* No memory control -> no swap control */
7491 if (mem_cgroup_disabled())
7492 cgroup_memory_noswap
= true;
7494 if (cgroup_memory_noswap
)
7497 WARN_ON(cgroup_add_dfl_cftypes(&memory_cgrp_subsys
, swap_files
));
7498 WARN_ON(cgroup_add_legacy_cftypes(&memory_cgrp_subsys
, memsw_files
));
7502 core_initcall(mem_cgroup_swap_init
);
7504 #endif /* CONFIG_MEMCG_SWAP */