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>
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/seq_buf.h>
66 #include <linux/uaccess.h>
68 #include <trace/events/vmscan.h>
70 struct cgroup_subsys memory_cgrp_subsys __read_mostly
;
71 EXPORT_SYMBOL(memory_cgrp_subsys
);
73 struct mem_cgroup
*root_mem_cgroup __read_mostly
;
75 #define MEM_CGROUP_RECLAIM_RETRIES 5
77 /* Socket memory accounting disabled? */
78 static bool cgroup_memory_nosocket
;
80 /* Kernel memory accounting disabled? */
81 static bool cgroup_memory_nokmem
;
83 /* Whether the swap controller is active */
84 #ifdef CONFIG_MEMCG_SWAP
85 int do_swap_account __read_mostly
;
87 #define do_swap_account 0
90 /* Whether legacy memory+swap accounting is active */
91 static bool do_memsw_account(void)
93 return !cgroup_subsys_on_dfl(memory_cgrp_subsys
) && do_swap_account
;
96 static const char *const mem_cgroup_lru_names
[] = {
104 #define THRESHOLDS_EVENTS_TARGET 128
105 #define SOFTLIMIT_EVENTS_TARGET 1024
106 #define NUMAINFO_EVENTS_TARGET 1024
109 * Cgroups above their limits are maintained in a RB-Tree, independent of
110 * their hierarchy representation
113 struct mem_cgroup_tree_per_node
{
114 struct rb_root rb_root
;
115 struct rb_node
*rb_rightmost
;
119 struct mem_cgroup_tree
{
120 struct mem_cgroup_tree_per_node
*rb_tree_per_node
[MAX_NUMNODES
];
123 static struct mem_cgroup_tree soft_limit_tree __read_mostly
;
126 struct mem_cgroup_eventfd_list
{
127 struct list_head list
;
128 struct eventfd_ctx
*eventfd
;
132 * cgroup_event represents events which userspace want to receive.
134 struct mem_cgroup_event
{
136 * memcg which the event belongs to.
138 struct mem_cgroup
*memcg
;
140 * eventfd to signal userspace about the event.
142 struct eventfd_ctx
*eventfd
;
144 * Each of these stored in a list by the cgroup.
146 struct list_head list
;
148 * register_event() callback will be used to add new userspace
149 * waiter for changes related to this event. Use eventfd_signal()
150 * on eventfd to send notification to userspace.
152 int (*register_event
)(struct mem_cgroup
*memcg
,
153 struct eventfd_ctx
*eventfd
, const char *args
);
155 * unregister_event() callback will be called when userspace closes
156 * the eventfd or on cgroup removing. This callback must be set,
157 * if you want provide notification functionality.
159 void (*unregister_event
)(struct mem_cgroup
*memcg
,
160 struct eventfd_ctx
*eventfd
);
162 * All fields below needed to unregister event when
163 * userspace closes eventfd.
166 wait_queue_head_t
*wqh
;
167 wait_queue_entry_t wait
;
168 struct work_struct remove
;
171 static void mem_cgroup_threshold(struct mem_cgroup
*memcg
);
172 static void mem_cgroup_oom_notify(struct mem_cgroup
*memcg
);
174 /* Stuffs for move charges at task migration. */
176 * Types of charges to be moved.
178 #define MOVE_ANON 0x1U
179 #define MOVE_FILE 0x2U
180 #define MOVE_MASK (MOVE_ANON | MOVE_FILE)
182 /* "mc" and its members are protected by cgroup_mutex */
183 static struct move_charge_struct
{
184 spinlock_t lock
; /* for from, to */
185 struct mm_struct
*mm
;
186 struct mem_cgroup
*from
;
187 struct mem_cgroup
*to
;
189 unsigned long precharge
;
190 unsigned long moved_charge
;
191 unsigned long moved_swap
;
192 struct task_struct
*moving_task
; /* a task moving charges */
193 wait_queue_head_t waitq
; /* a waitq for other context */
195 .lock
= __SPIN_LOCK_UNLOCKED(mc
.lock
),
196 .waitq
= __WAIT_QUEUE_HEAD_INITIALIZER(mc
.waitq
),
200 * Maximum loops in mem_cgroup_hierarchical_reclaim(), used for soft
201 * limit reclaim to prevent infinite loops, if they ever occur.
203 #define MEM_CGROUP_MAX_RECLAIM_LOOPS 100
204 #define MEM_CGROUP_MAX_SOFT_LIMIT_RECLAIM_LOOPS 2
207 MEM_CGROUP_CHARGE_TYPE_CACHE
= 0,
208 MEM_CGROUP_CHARGE_TYPE_ANON
,
209 MEM_CGROUP_CHARGE_TYPE_SWAPOUT
, /* for accounting swapcache */
210 MEM_CGROUP_CHARGE_TYPE_DROP
, /* a page was unused swap cache */
214 /* for encoding cft->private value on file */
223 #define MEMFILE_PRIVATE(x, val) ((x) << 16 | (val))
224 #define MEMFILE_TYPE(val) ((val) >> 16 & 0xffff)
225 #define MEMFILE_ATTR(val) ((val) & 0xffff)
226 /* Used for OOM nofiier */
227 #define OOM_CONTROL (0)
230 * Iteration constructs for visiting all cgroups (under a tree). If
231 * loops are exited prematurely (break), mem_cgroup_iter_break() must
232 * be used for reference counting.
234 #define for_each_mem_cgroup_tree(iter, root) \
235 for (iter = mem_cgroup_iter(root, NULL, NULL); \
237 iter = mem_cgroup_iter(root, iter, NULL))
239 #define for_each_mem_cgroup(iter) \
240 for (iter = mem_cgroup_iter(NULL, NULL, NULL); \
242 iter = mem_cgroup_iter(NULL, iter, NULL))
244 static inline bool should_force_charge(void)
246 return tsk_is_oom_victim(current
) || fatal_signal_pending(current
) ||
247 (current
->flags
& PF_EXITING
);
250 /* Some nice accessors for the vmpressure. */
251 struct vmpressure
*memcg_to_vmpressure(struct mem_cgroup
*memcg
)
254 memcg
= root_mem_cgroup
;
255 return &memcg
->vmpressure
;
258 struct cgroup_subsys_state
*vmpressure_to_css(struct vmpressure
*vmpr
)
260 return &container_of(vmpr
, struct mem_cgroup
, vmpressure
)->css
;
263 #ifdef CONFIG_MEMCG_KMEM
265 * This will be the memcg's index in each cache's ->memcg_params.memcg_caches.
266 * The main reason for not using cgroup id for this:
267 * this works better in sparse environments, where we have a lot of memcgs,
268 * but only a few kmem-limited. Or also, if we have, for instance, 200
269 * memcgs, and none but the 200th is kmem-limited, we'd have to have a
270 * 200 entry array for that.
272 * The current size of the caches array is stored in memcg_nr_cache_ids. It
273 * will double each time we have to increase it.
275 static DEFINE_IDA(memcg_cache_ida
);
276 int memcg_nr_cache_ids
;
278 /* Protects memcg_nr_cache_ids */
279 static DECLARE_RWSEM(memcg_cache_ids_sem
);
281 void memcg_get_cache_ids(void)
283 down_read(&memcg_cache_ids_sem
);
286 void memcg_put_cache_ids(void)
288 up_read(&memcg_cache_ids_sem
);
292 * MIN_SIZE is different than 1, because we would like to avoid going through
293 * the alloc/free process all the time. In a small machine, 4 kmem-limited
294 * cgroups is a reasonable guess. In the future, it could be a parameter or
295 * tunable, but that is strictly not necessary.
297 * MAX_SIZE should be as large as the number of cgrp_ids. Ideally, we could get
298 * this constant directly from cgroup, but it is understandable that this is
299 * better kept as an internal representation in cgroup.c. In any case, the
300 * cgrp_id space is not getting any smaller, and we don't have to necessarily
301 * increase ours as well if it increases.
303 #define MEMCG_CACHES_MIN_SIZE 4
304 #define MEMCG_CACHES_MAX_SIZE MEM_CGROUP_ID_MAX
307 * A lot of the calls to the cache allocation functions are expected to be
308 * inlined by the compiler. Since the calls to memcg_kmem_get_cache are
309 * conditional to this static branch, we'll have to allow modules that does
310 * kmem_cache_alloc and the such to see this symbol as well
312 DEFINE_STATIC_KEY_FALSE(memcg_kmem_enabled_key
);
313 EXPORT_SYMBOL(memcg_kmem_enabled_key
);
315 struct workqueue_struct
*memcg_kmem_cache_wq
;
317 static int memcg_shrinker_map_size
;
318 static DEFINE_MUTEX(memcg_shrinker_map_mutex
);
320 static void memcg_free_shrinker_map_rcu(struct rcu_head
*head
)
322 kvfree(container_of(head
, struct memcg_shrinker_map
, rcu
));
325 static int memcg_expand_one_shrinker_map(struct mem_cgroup
*memcg
,
326 int size
, int old_size
)
328 struct memcg_shrinker_map
*new, *old
;
331 lockdep_assert_held(&memcg_shrinker_map_mutex
);
334 old
= rcu_dereference_protected(
335 mem_cgroup_nodeinfo(memcg
, nid
)->shrinker_map
, true);
336 /* Not yet online memcg */
340 new = kvmalloc(sizeof(*new) + size
, GFP_KERNEL
);
344 /* Set all old bits, clear all new bits */
345 memset(new->map
, (int)0xff, old_size
);
346 memset((void *)new->map
+ old_size
, 0, size
- old_size
);
348 rcu_assign_pointer(memcg
->nodeinfo
[nid
]->shrinker_map
, new);
349 call_rcu(&old
->rcu
, memcg_free_shrinker_map_rcu
);
355 static void memcg_free_shrinker_maps(struct mem_cgroup
*memcg
)
357 struct mem_cgroup_per_node
*pn
;
358 struct memcg_shrinker_map
*map
;
361 if (mem_cgroup_is_root(memcg
))
365 pn
= mem_cgroup_nodeinfo(memcg
, nid
);
366 map
= rcu_dereference_protected(pn
->shrinker_map
, true);
369 rcu_assign_pointer(pn
->shrinker_map
, NULL
);
373 static int memcg_alloc_shrinker_maps(struct mem_cgroup
*memcg
)
375 struct memcg_shrinker_map
*map
;
376 int nid
, size
, ret
= 0;
378 if (mem_cgroup_is_root(memcg
))
381 mutex_lock(&memcg_shrinker_map_mutex
);
382 size
= memcg_shrinker_map_size
;
384 map
= kvzalloc(sizeof(*map
) + size
, GFP_KERNEL
);
386 memcg_free_shrinker_maps(memcg
);
390 rcu_assign_pointer(memcg
->nodeinfo
[nid
]->shrinker_map
, map
);
392 mutex_unlock(&memcg_shrinker_map_mutex
);
397 int memcg_expand_shrinker_maps(int new_id
)
399 int size
, old_size
, ret
= 0;
400 struct mem_cgroup
*memcg
;
402 size
= DIV_ROUND_UP(new_id
+ 1, BITS_PER_LONG
) * sizeof(unsigned long);
403 old_size
= memcg_shrinker_map_size
;
404 if (size
<= old_size
)
407 mutex_lock(&memcg_shrinker_map_mutex
);
408 if (!root_mem_cgroup
)
411 for_each_mem_cgroup(memcg
) {
412 if (mem_cgroup_is_root(memcg
))
414 ret
= memcg_expand_one_shrinker_map(memcg
, size
, old_size
);
420 memcg_shrinker_map_size
= size
;
421 mutex_unlock(&memcg_shrinker_map_mutex
);
425 void memcg_set_shrinker_bit(struct mem_cgroup
*memcg
, int nid
, int shrinker_id
)
427 if (shrinker_id
>= 0 && memcg
&& !mem_cgroup_is_root(memcg
)) {
428 struct memcg_shrinker_map
*map
;
431 map
= rcu_dereference(memcg
->nodeinfo
[nid
]->shrinker_map
);
432 /* Pairs with smp mb in shrink_slab() */
433 smp_mb__before_atomic();
434 set_bit(shrinker_id
, map
->map
);
439 #else /* CONFIG_MEMCG_KMEM */
440 static int memcg_alloc_shrinker_maps(struct mem_cgroup
*memcg
)
444 static void memcg_free_shrinker_maps(struct mem_cgroup
*memcg
) { }
445 #endif /* CONFIG_MEMCG_KMEM */
448 * mem_cgroup_css_from_page - css of the memcg associated with a page
449 * @page: page of interest
451 * If memcg is bound to the default hierarchy, css of the memcg associated
452 * with @page is returned. The returned css remains associated with @page
453 * until it is released.
455 * If memcg is bound to a traditional hierarchy, the css of root_mem_cgroup
458 struct cgroup_subsys_state
*mem_cgroup_css_from_page(struct page
*page
)
460 struct mem_cgroup
*memcg
;
462 memcg
= page
->mem_cgroup
;
464 if (!memcg
|| !cgroup_subsys_on_dfl(memory_cgrp_subsys
))
465 memcg
= root_mem_cgroup
;
471 * page_cgroup_ino - return inode number of the memcg a page is charged to
474 * Look up the closest online ancestor of the memory cgroup @page is charged to
475 * and return its inode number or 0 if @page is not charged to any cgroup. It
476 * is safe to call this function without holding a reference to @page.
478 * Note, this function is inherently racy, because there is nothing to prevent
479 * the cgroup inode from getting torn down and potentially reallocated a moment
480 * after page_cgroup_ino() returns, so it only should be used by callers that
481 * do not care (such as procfs interfaces).
483 ino_t
page_cgroup_ino(struct page
*page
)
485 struct mem_cgroup
*memcg
;
486 unsigned long ino
= 0;
489 if (PageHead(page
) && PageSlab(page
))
490 memcg
= memcg_from_slab_page(page
);
492 memcg
= READ_ONCE(page
->mem_cgroup
);
493 while (memcg
&& !(memcg
->css
.flags
& CSS_ONLINE
))
494 memcg
= parent_mem_cgroup(memcg
);
496 ino
= cgroup_ino(memcg
->css
.cgroup
);
501 static struct mem_cgroup_per_node
*
502 mem_cgroup_page_nodeinfo(struct mem_cgroup
*memcg
, struct page
*page
)
504 int nid
= page_to_nid(page
);
506 return memcg
->nodeinfo
[nid
];
509 static struct mem_cgroup_tree_per_node
*
510 soft_limit_tree_node(int nid
)
512 return soft_limit_tree
.rb_tree_per_node
[nid
];
515 static struct mem_cgroup_tree_per_node
*
516 soft_limit_tree_from_page(struct page
*page
)
518 int nid
= page_to_nid(page
);
520 return soft_limit_tree
.rb_tree_per_node
[nid
];
523 static void __mem_cgroup_insert_exceeded(struct mem_cgroup_per_node
*mz
,
524 struct mem_cgroup_tree_per_node
*mctz
,
525 unsigned long new_usage_in_excess
)
527 struct rb_node
**p
= &mctz
->rb_root
.rb_node
;
528 struct rb_node
*parent
= NULL
;
529 struct mem_cgroup_per_node
*mz_node
;
530 bool rightmost
= true;
535 mz
->usage_in_excess
= new_usage_in_excess
;
536 if (!mz
->usage_in_excess
)
540 mz_node
= rb_entry(parent
, struct mem_cgroup_per_node
,
542 if (mz
->usage_in_excess
< mz_node
->usage_in_excess
) {
548 * We can't avoid mem cgroups that are over their soft
549 * limit by the same amount
551 else if (mz
->usage_in_excess
>= mz_node
->usage_in_excess
)
556 mctz
->rb_rightmost
= &mz
->tree_node
;
558 rb_link_node(&mz
->tree_node
, parent
, p
);
559 rb_insert_color(&mz
->tree_node
, &mctz
->rb_root
);
563 static void __mem_cgroup_remove_exceeded(struct mem_cgroup_per_node
*mz
,
564 struct mem_cgroup_tree_per_node
*mctz
)
569 if (&mz
->tree_node
== mctz
->rb_rightmost
)
570 mctz
->rb_rightmost
= rb_prev(&mz
->tree_node
);
572 rb_erase(&mz
->tree_node
, &mctz
->rb_root
);
576 static void mem_cgroup_remove_exceeded(struct mem_cgroup_per_node
*mz
,
577 struct mem_cgroup_tree_per_node
*mctz
)
581 spin_lock_irqsave(&mctz
->lock
, flags
);
582 __mem_cgroup_remove_exceeded(mz
, mctz
);
583 spin_unlock_irqrestore(&mctz
->lock
, flags
);
586 static unsigned long soft_limit_excess(struct mem_cgroup
*memcg
)
588 unsigned long nr_pages
= page_counter_read(&memcg
->memory
);
589 unsigned long soft_limit
= READ_ONCE(memcg
->soft_limit
);
590 unsigned long excess
= 0;
592 if (nr_pages
> soft_limit
)
593 excess
= nr_pages
- soft_limit
;
598 static void mem_cgroup_update_tree(struct mem_cgroup
*memcg
, struct page
*page
)
600 unsigned long excess
;
601 struct mem_cgroup_per_node
*mz
;
602 struct mem_cgroup_tree_per_node
*mctz
;
604 mctz
= soft_limit_tree_from_page(page
);
608 * Necessary to update all ancestors when hierarchy is used.
609 * because their event counter is not touched.
611 for (; memcg
; memcg
= parent_mem_cgroup(memcg
)) {
612 mz
= mem_cgroup_page_nodeinfo(memcg
, page
);
613 excess
= soft_limit_excess(memcg
);
615 * We have to update the tree if mz is on RB-tree or
616 * mem is over its softlimit.
618 if (excess
|| mz
->on_tree
) {
621 spin_lock_irqsave(&mctz
->lock
, flags
);
622 /* if on-tree, remove it */
624 __mem_cgroup_remove_exceeded(mz
, mctz
);
626 * Insert again. mz->usage_in_excess will be updated.
627 * If excess is 0, no tree ops.
629 __mem_cgroup_insert_exceeded(mz
, mctz
, excess
);
630 spin_unlock_irqrestore(&mctz
->lock
, flags
);
635 static void mem_cgroup_remove_from_trees(struct mem_cgroup
*memcg
)
637 struct mem_cgroup_tree_per_node
*mctz
;
638 struct mem_cgroup_per_node
*mz
;
642 mz
= mem_cgroup_nodeinfo(memcg
, nid
);
643 mctz
= soft_limit_tree_node(nid
);
645 mem_cgroup_remove_exceeded(mz
, mctz
);
649 static struct mem_cgroup_per_node
*
650 __mem_cgroup_largest_soft_limit_node(struct mem_cgroup_tree_per_node
*mctz
)
652 struct mem_cgroup_per_node
*mz
;
656 if (!mctz
->rb_rightmost
)
657 goto done
; /* Nothing to reclaim from */
659 mz
= rb_entry(mctz
->rb_rightmost
,
660 struct mem_cgroup_per_node
, tree_node
);
662 * Remove the node now but someone else can add it back,
663 * we will to add it back at the end of reclaim to its correct
664 * position in the tree.
666 __mem_cgroup_remove_exceeded(mz
, mctz
);
667 if (!soft_limit_excess(mz
->memcg
) ||
668 !css_tryget_online(&mz
->memcg
->css
))
674 static struct mem_cgroup_per_node
*
675 mem_cgroup_largest_soft_limit_node(struct mem_cgroup_tree_per_node
*mctz
)
677 struct mem_cgroup_per_node
*mz
;
679 spin_lock_irq(&mctz
->lock
);
680 mz
= __mem_cgroup_largest_soft_limit_node(mctz
);
681 spin_unlock_irq(&mctz
->lock
);
686 * __mod_memcg_state - update cgroup memory statistics
687 * @memcg: the memory cgroup
688 * @idx: the stat item - can be enum memcg_stat_item or enum node_stat_item
689 * @val: delta to add to the counter, can be negative
691 void __mod_memcg_state(struct mem_cgroup
*memcg
, int idx
, int val
)
695 if (mem_cgroup_disabled())
698 x
= val
+ __this_cpu_read(memcg
->vmstats_percpu
->stat
[idx
]);
699 if (unlikely(abs(x
) > MEMCG_CHARGE_BATCH
)) {
700 struct mem_cgroup
*mi
;
703 * Batch local counters to keep them in sync with
704 * the hierarchical ones.
706 __this_cpu_add(memcg
->vmstats_local
->stat
[idx
], x
);
707 for (mi
= memcg
; mi
; mi
= parent_mem_cgroup(mi
))
708 atomic_long_add(x
, &mi
->vmstats
[idx
]);
711 __this_cpu_write(memcg
->vmstats_percpu
->stat
[idx
], x
);
714 static struct mem_cgroup_per_node
*
715 parent_nodeinfo(struct mem_cgroup_per_node
*pn
, int nid
)
717 struct mem_cgroup
*parent
;
719 parent
= parent_mem_cgroup(pn
->memcg
);
722 return mem_cgroup_nodeinfo(parent
, nid
);
726 * __mod_lruvec_state - update lruvec memory statistics
727 * @lruvec: the lruvec
728 * @idx: the stat item
729 * @val: delta to add to the counter, can be negative
731 * The lruvec is the intersection of the NUMA node and a cgroup. This
732 * function updates the all three counters that are affected by a
733 * change of state at this level: per-node, per-cgroup, per-lruvec.
735 void __mod_lruvec_state(struct lruvec
*lruvec
, enum node_stat_item idx
,
738 pg_data_t
*pgdat
= lruvec_pgdat(lruvec
);
739 struct mem_cgroup_per_node
*pn
;
740 struct mem_cgroup
*memcg
;
744 __mod_node_page_state(pgdat
, idx
, val
);
746 if (mem_cgroup_disabled())
749 pn
= container_of(lruvec
, struct mem_cgroup_per_node
, lruvec
);
753 __mod_memcg_state(memcg
, idx
, val
);
755 x
= val
+ __this_cpu_read(pn
->lruvec_stat_cpu
->count
[idx
]);
756 if (unlikely(abs(x
) > MEMCG_CHARGE_BATCH
)) {
757 struct mem_cgroup_per_node
*pi
;
760 * Batch local counters to keep them in sync with
761 * the hierarchical ones.
763 __this_cpu_add(pn
->lruvec_stat_local
->count
[idx
], x
);
764 for (pi
= pn
; pi
; pi
= parent_nodeinfo(pi
, pgdat
->node_id
))
765 atomic_long_add(x
, &pi
->lruvec_stat
[idx
]);
768 __this_cpu_write(pn
->lruvec_stat_cpu
->count
[idx
], x
);
771 void __mod_lruvec_slab_state(void *p
, enum node_stat_item idx
, int val
)
773 struct page
*page
= virt_to_head_page(p
);
774 pg_data_t
*pgdat
= page_pgdat(page
);
775 struct mem_cgroup
*memcg
;
776 struct lruvec
*lruvec
;
779 memcg
= memcg_from_slab_page(page
);
781 /* Untracked pages have no memcg, no lruvec. Update only the node */
782 if (!memcg
|| memcg
== root_mem_cgroup
) {
783 __mod_node_page_state(pgdat
, idx
, val
);
785 lruvec
= mem_cgroup_lruvec(pgdat
, memcg
);
786 __mod_lruvec_state(lruvec
, idx
, val
);
792 * __count_memcg_events - account VM events in a cgroup
793 * @memcg: the memory cgroup
794 * @idx: the event item
795 * @count: the number of events that occured
797 void __count_memcg_events(struct mem_cgroup
*memcg
, enum vm_event_item idx
,
802 if (mem_cgroup_disabled())
805 x
= count
+ __this_cpu_read(memcg
->vmstats_percpu
->events
[idx
]);
806 if (unlikely(x
> MEMCG_CHARGE_BATCH
)) {
807 struct mem_cgroup
*mi
;
810 * Batch local counters to keep them in sync with
811 * the hierarchical ones.
813 __this_cpu_add(memcg
->vmstats_local
->events
[idx
], x
);
814 for (mi
= memcg
; mi
; mi
= parent_mem_cgroup(mi
))
815 atomic_long_add(x
, &mi
->vmevents
[idx
]);
818 __this_cpu_write(memcg
->vmstats_percpu
->events
[idx
], x
);
821 static unsigned long memcg_events(struct mem_cgroup
*memcg
, int event
)
823 return atomic_long_read(&memcg
->vmevents
[event
]);
826 static unsigned long memcg_events_local(struct mem_cgroup
*memcg
, int event
)
831 for_each_possible_cpu(cpu
)
832 x
+= per_cpu(memcg
->vmstats_local
->events
[event
], cpu
);
836 static void mem_cgroup_charge_statistics(struct mem_cgroup
*memcg
,
838 bool compound
, int nr_pages
)
841 * Here, RSS means 'mapped anon' and anon's SwapCache. Shmem/tmpfs is
842 * counted as CACHE even if it's on ANON LRU.
845 __mod_memcg_state(memcg
, MEMCG_RSS
, nr_pages
);
847 __mod_memcg_state(memcg
, MEMCG_CACHE
, nr_pages
);
848 if (PageSwapBacked(page
))
849 __mod_memcg_state(memcg
, NR_SHMEM
, nr_pages
);
853 VM_BUG_ON_PAGE(!PageTransHuge(page
), page
);
854 __mod_memcg_state(memcg
, MEMCG_RSS_HUGE
, nr_pages
);
857 /* pagein of a big page is an event. So, ignore page size */
859 __count_memcg_events(memcg
, PGPGIN
, 1);
861 __count_memcg_events(memcg
, PGPGOUT
, 1);
862 nr_pages
= -nr_pages
; /* for event */
865 __this_cpu_add(memcg
->vmstats_percpu
->nr_page_events
, nr_pages
);
868 static bool mem_cgroup_event_ratelimit(struct mem_cgroup
*memcg
,
869 enum mem_cgroup_events_target target
)
871 unsigned long val
, next
;
873 val
= __this_cpu_read(memcg
->vmstats_percpu
->nr_page_events
);
874 next
= __this_cpu_read(memcg
->vmstats_percpu
->targets
[target
]);
875 /* from time_after() in jiffies.h */
876 if ((long)(next
- val
) < 0) {
878 case MEM_CGROUP_TARGET_THRESH
:
879 next
= val
+ THRESHOLDS_EVENTS_TARGET
;
881 case MEM_CGROUP_TARGET_SOFTLIMIT
:
882 next
= val
+ SOFTLIMIT_EVENTS_TARGET
;
884 case MEM_CGROUP_TARGET_NUMAINFO
:
885 next
= val
+ NUMAINFO_EVENTS_TARGET
;
890 __this_cpu_write(memcg
->vmstats_percpu
->targets
[target
], next
);
897 * Check events in order.
900 static void memcg_check_events(struct mem_cgroup
*memcg
, struct page
*page
)
902 /* threshold event is triggered in finer grain than soft limit */
903 if (unlikely(mem_cgroup_event_ratelimit(memcg
,
904 MEM_CGROUP_TARGET_THRESH
))) {
906 bool do_numainfo __maybe_unused
;
908 do_softlimit
= mem_cgroup_event_ratelimit(memcg
,
909 MEM_CGROUP_TARGET_SOFTLIMIT
);
911 do_numainfo
= mem_cgroup_event_ratelimit(memcg
,
912 MEM_CGROUP_TARGET_NUMAINFO
);
914 mem_cgroup_threshold(memcg
);
915 if (unlikely(do_softlimit
))
916 mem_cgroup_update_tree(memcg
, page
);
918 if (unlikely(do_numainfo
))
919 atomic_inc(&memcg
->numainfo_events
);
924 struct mem_cgroup
*mem_cgroup_from_task(struct task_struct
*p
)
927 * mm_update_next_owner() may clear mm->owner to NULL
928 * if it races with swapoff, page migration, etc.
929 * So this can be called with p == NULL.
934 return mem_cgroup_from_css(task_css(p
, memory_cgrp_id
));
936 EXPORT_SYMBOL(mem_cgroup_from_task
);
939 * get_mem_cgroup_from_mm: Obtain a reference on given mm_struct's memcg.
940 * @mm: mm from which memcg should be extracted. It can be NULL.
942 * Obtain a reference on mm->memcg and returns it if successful. Otherwise
943 * root_mem_cgroup is returned. However if mem_cgroup is disabled, NULL is
946 struct mem_cgroup
*get_mem_cgroup_from_mm(struct mm_struct
*mm
)
948 struct mem_cgroup
*memcg
;
950 if (mem_cgroup_disabled())
956 * Page cache insertions can happen withou an
957 * actual mm context, e.g. during disk probing
958 * on boot, loopback IO, acct() writes etc.
961 memcg
= root_mem_cgroup
;
963 memcg
= mem_cgroup_from_task(rcu_dereference(mm
->owner
));
964 if (unlikely(!memcg
))
965 memcg
= root_mem_cgroup
;
967 } while (!css_tryget_online(&memcg
->css
));
971 EXPORT_SYMBOL(get_mem_cgroup_from_mm
);
974 * get_mem_cgroup_from_page: Obtain a reference on given page's memcg.
975 * @page: page from which memcg should be extracted.
977 * Obtain a reference on page->memcg and returns it if successful. Otherwise
978 * root_mem_cgroup is returned.
980 struct mem_cgroup
*get_mem_cgroup_from_page(struct page
*page
)
982 struct mem_cgroup
*memcg
= page
->mem_cgroup
;
984 if (mem_cgroup_disabled())
988 if (!memcg
|| !css_tryget_online(&memcg
->css
))
989 memcg
= root_mem_cgroup
;
993 EXPORT_SYMBOL(get_mem_cgroup_from_page
);
996 * If current->active_memcg is non-NULL, do not fallback to current->mm->memcg.
998 static __always_inline
struct mem_cgroup
*get_mem_cgroup_from_current(void)
1000 if (unlikely(current
->active_memcg
)) {
1001 struct mem_cgroup
*memcg
= root_mem_cgroup
;
1004 if (css_tryget_online(¤t
->active_memcg
->css
))
1005 memcg
= current
->active_memcg
;
1009 return get_mem_cgroup_from_mm(current
->mm
);
1013 * mem_cgroup_iter - iterate over memory cgroup hierarchy
1014 * @root: hierarchy root
1015 * @prev: previously returned memcg, NULL on first invocation
1016 * @reclaim: cookie for shared reclaim walks, NULL for full walks
1018 * Returns references to children of the hierarchy below @root, or
1019 * @root itself, or %NULL after a full round-trip.
1021 * Caller must pass the return value in @prev on subsequent
1022 * invocations for reference counting, or use mem_cgroup_iter_break()
1023 * to cancel a hierarchy walk before the round-trip is complete.
1025 * Reclaimers can specify a node and a priority level in @reclaim to
1026 * divide up the memcgs in the hierarchy among all concurrent
1027 * reclaimers operating on the same node and priority.
1029 struct mem_cgroup
*mem_cgroup_iter(struct mem_cgroup
*root
,
1030 struct mem_cgroup
*prev
,
1031 struct mem_cgroup_reclaim_cookie
*reclaim
)
1033 struct mem_cgroup_reclaim_iter
*uninitialized_var(iter
);
1034 struct cgroup_subsys_state
*css
= NULL
;
1035 struct mem_cgroup
*memcg
= NULL
;
1036 struct mem_cgroup
*pos
= NULL
;
1038 if (mem_cgroup_disabled())
1042 root
= root_mem_cgroup
;
1044 if (prev
&& !reclaim
)
1047 if (!root
->use_hierarchy
&& root
!= root_mem_cgroup
) {
1056 struct mem_cgroup_per_node
*mz
;
1058 mz
= mem_cgroup_nodeinfo(root
, reclaim
->pgdat
->node_id
);
1059 iter
= &mz
->iter
[reclaim
->priority
];
1061 if (prev
&& reclaim
->generation
!= iter
->generation
)
1065 pos
= READ_ONCE(iter
->position
);
1066 if (!pos
|| css_tryget(&pos
->css
))
1069 * css reference reached zero, so iter->position will
1070 * be cleared by ->css_released. However, we should not
1071 * rely on this happening soon, because ->css_released
1072 * is called from a work queue, and by busy-waiting we
1073 * might block it. So we clear iter->position right
1076 (void)cmpxchg(&iter
->position
, pos
, NULL
);
1084 css
= css_next_descendant_pre(css
, &root
->css
);
1087 * Reclaimers share the hierarchy walk, and a
1088 * new one might jump in right at the end of
1089 * the hierarchy - make sure they see at least
1090 * one group and restart from the beginning.
1098 * Verify the css and acquire a reference. The root
1099 * is provided by the caller, so we know it's alive
1100 * and kicking, and don't take an extra reference.
1102 memcg
= mem_cgroup_from_css(css
);
1104 if (css
== &root
->css
)
1107 if (css_tryget(css
))
1115 * The position could have already been updated by a competing
1116 * thread, so check that the value hasn't changed since we read
1117 * it to avoid reclaiming from the same cgroup twice.
1119 (void)cmpxchg(&iter
->position
, pos
, memcg
);
1127 reclaim
->generation
= iter
->generation
;
1133 if (prev
&& prev
!= root
)
1134 css_put(&prev
->css
);
1140 * mem_cgroup_iter_break - abort a hierarchy walk prematurely
1141 * @root: hierarchy root
1142 * @prev: last visited hierarchy member as returned by mem_cgroup_iter()
1144 void mem_cgroup_iter_break(struct mem_cgroup
*root
,
1145 struct mem_cgroup
*prev
)
1148 root
= root_mem_cgroup
;
1149 if (prev
&& prev
!= root
)
1150 css_put(&prev
->css
);
1153 static void __invalidate_reclaim_iterators(struct mem_cgroup
*from
,
1154 struct mem_cgroup
*dead_memcg
)
1156 struct mem_cgroup_reclaim_iter
*iter
;
1157 struct mem_cgroup_per_node
*mz
;
1161 for_each_node(nid
) {
1162 mz
= mem_cgroup_nodeinfo(from
, nid
);
1163 for (i
= 0; i
<= DEF_PRIORITY
; i
++) {
1164 iter
= &mz
->iter
[i
];
1165 cmpxchg(&iter
->position
,
1171 static void invalidate_reclaim_iterators(struct mem_cgroup
*dead_memcg
)
1173 struct mem_cgroup
*memcg
= dead_memcg
;
1174 struct mem_cgroup
*last
;
1177 __invalidate_reclaim_iterators(memcg
, dead_memcg
);
1179 } while ((memcg
= parent_mem_cgroup(memcg
)));
1182 * When cgruop1 non-hierarchy mode is used,
1183 * parent_mem_cgroup() does not walk all the way up to the
1184 * cgroup root (root_mem_cgroup). So we have to handle
1185 * dead_memcg from cgroup root separately.
1187 if (last
!= root_mem_cgroup
)
1188 __invalidate_reclaim_iterators(root_mem_cgroup
,
1193 * mem_cgroup_scan_tasks - iterate over tasks of a memory cgroup hierarchy
1194 * @memcg: hierarchy root
1195 * @fn: function to call for each task
1196 * @arg: argument passed to @fn
1198 * This function iterates over tasks attached to @memcg or to any of its
1199 * descendants and calls @fn for each task. If @fn returns a non-zero
1200 * value, the function breaks the iteration loop and returns the value.
1201 * Otherwise, it will iterate over all tasks and return 0.
1203 * This function must not be called for the root memory cgroup.
1205 int mem_cgroup_scan_tasks(struct mem_cgroup
*memcg
,
1206 int (*fn
)(struct task_struct
*, void *), void *arg
)
1208 struct mem_cgroup
*iter
;
1211 BUG_ON(memcg
== root_mem_cgroup
);
1213 for_each_mem_cgroup_tree(iter
, memcg
) {
1214 struct css_task_iter it
;
1215 struct task_struct
*task
;
1217 css_task_iter_start(&iter
->css
, CSS_TASK_ITER_PROCS
, &it
);
1218 while (!ret
&& (task
= css_task_iter_next(&it
)))
1219 ret
= fn(task
, arg
);
1220 css_task_iter_end(&it
);
1222 mem_cgroup_iter_break(memcg
, iter
);
1230 * mem_cgroup_page_lruvec - return lruvec for isolating/putting an LRU page
1232 * @pgdat: pgdat of the page
1234 * This function is only safe when following the LRU page isolation
1235 * and putback protocol: the LRU lock must be held, and the page must
1236 * either be PageLRU() or the caller must have isolated/allocated it.
1238 struct lruvec
*mem_cgroup_page_lruvec(struct page
*page
, struct pglist_data
*pgdat
)
1240 struct mem_cgroup_per_node
*mz
;
1241 struct mem_cgroup
*memcg
;
1242 struct lruvec
*lruvec
;
1244 if (mem_cgroup_disabled()) {
1245 lruvec
= &pgdat
->lruvec
;
1249 memcg
= page
->mem_cgroup
;
1251 * Swapcache readahead pages are added to the LRU - and
1252 * possibly migrated - before they are charged.
1255 memcg
= root_mem_cgroup
;
1257 mz
= mem_cgroup_page_nodeinfo(memcg
, page
);
1258 lruvec
= &mz
->lruvec
;
1261 * Since a node can be onlined after the mem_cgroup was created,
1262 * we have to be prepared to initialize lruvec->zone here;
1263 * and if offlined then reonlined, we need to reinitialize it.
1265 if (unlikely(lruvec
->pgdat
!= pgdat
))
1266 lruvec
->pgdat
= pgdat
;
1271 * mem_cgroup_update_lru_size - account for adding or removing an lru page
1272 * @lruvec: mem_cgroup per zone lru vector
1273 * @lru: index of lru list the page is sitting on
1274 * @zid: zone id of the accounted pages
1275 * @nr_pages: positive when adding or negative when removing
1277 * This function must be called under lru_lock, just before a page is added
1278 * to or just after a page is removed from an lru list (that ordering being
1279 * so as to allow it to check that lru_size 0 is consistent with list_empty).
1281 void mem_cgroup_update_lru_size(struct lruvec
*lruvec
, enum lru_list lru
,
1282 int zid
, int nr_pages
)
1284 struct mem_cgroup_per_node
*mz
;
1285 unsigned long *lru_size
;
1288 if (mem_cgroup_disabled())
1291 mz
= container_of(lruvec
, struct mem_cgroup_per_node
, lruvec
);
1292 lru_size
= &mz
->lru_zone_size
[zid
][lru
];
1295 *lru_size
+= nr_pages
;
1298 if (WARN_ONCE(size
< 0,
1299 "%s(%p, %d, %d): lru_size %ld\n",
1300 __func__
, lruvec
, lru
, nr_pages
, size
)) {
1306 *lru_size
+= nr_pages
;
1310 * mem_cgroup_margin - calculate chargeable space of a memory cgroup
1311 * @memcg: the memory cgroup
1313 * Returns the maximum amount of memory @mem can be charged with, in
1316 static unsigned long mem_cgroup_margin(struct mem_cgroup
*memcg
)
1318 unsigned long margin
= 0;
1319 unsigned long count
;
1320 unsigned long limit
;
1322 count
= page_counter_read(&memcg
->memory
);
1323 limit
= READ_ONCE(memcg
->memory
.max
);
1325 margin
= limit
- count
;
1327 if (do_memsw_account()) {
1328 count
= page_counter_read(&memcg
->memsw
);
1329 limit
= READ_ONCE(memcg
->memsw
.max
);
1331 margin
= min(margin
, limit
- count
);
1340 * A routine for checking "mem" is under move_account() or not.
1342 * Checking a cgroup is mc.from or mc.to or under hierarchy of
1343 * moving cgroups. This is for waiting at high-memory pressure
1346 static bool mem_cgroup_under_move(struct mem_cgroup
*memcg
)
1348 struct mem_cgroup
*from
;
1349 struct mem_cgroup
*to
;
1352 * Unlike task_move routines, we access mc.to, mc.from not under
1353 * mutual exclusion by cgroup_mutex. Here, we take spinlock instead.
1355 spin_lock(&mc
.lock
);
1361 ret
= mem_cgroup_is_descendant(from
, memcg
) ||
1362 mem_cgroup_is_descendant(to
, memcg
);
1364 spin_unlock(&mc
.lock
);
1368 static bool mem_cgroup_wait_acct_move(struct mem_cgroup
*memcg
)
1370 if (mc
.moving_task
&& current
!= mc
.moving_task
) {
1371 if (mem_cgroup_under_move(memcg
)) {
1373 prepare_to_wait(&mc
.waitq
, &wait
, TASK_INTERRUPTIBLE
);
1374 /* moving charge context might have finished. */
1377 finish_wait(&mc
.waitq
, &wait
);
1384 static char *memory_stat_format(struct mem_cgroup
*memcg
)
1389 seq_buf_init(&s
, kmalloc(PAGE_SIZE
, GFP_KERNEL
), PAGE_SIZE
);
1394 * Provide statistics on the state of the memory subsystem as
1395 * well as cumulative event counters that show past behavior.
1397 * This list is ordered following a combination of these gradients:
1398 * 1) generic big picture -> specifics and details
1399 * 2) reflecting userspace activity -> reflecting kernel heuristics
1401 * Current memory state:
1404 seq_buf_printf(&s
, "anon %llu\n",
1405 (u64
)memcg_page_state(memcg
, MEMCG_RSS
) *
1407 seq_buf_printf(&s
, "file %llu\n",
1408 (u64
)memcg_page_state(memcg
, MEMCG_CACHE
) *
1410 seq_buf_printf(&s
, "kernel_stack %llu\n",
1411 (u64
)memcg_page_state(memcg
, MEMCG_KERNEL_STACK_KB
) *
1413 seq_buf_printf(&s
, "slab %llu\n",
1414 (u64
)(memcg_page_state(memcg
, NR_SLAB_RECLAIMABLE
) +
1415 memcg_page_state(memcg
, NR_SLAB_UNRECLAIMABLE
)) *
1417 seq_buf_printf(&s
, "sock %llu\n",
1418 (u64
)memcg_page_state(memcg
, MEMCG_SOCK
) *
1421 seq_buf_printf(&s
, "shmem %llu\n",
1422 (u64
)memcg_page_state(memcg
, NR_SHMEM
) *
1424 seq_buf_printf(&s
, "file_mapped %llu\n",
1425 (u64
)memcg_page_state(memcg
, NR_FILE_MAPPED
) *
1427 seq_buf_printf(&s
, "file_dirty %llu\n",
1428 (u64
)memcg_page_state(memcg
, NR_FILE_DIRTY
) *
1430 seq_buf_printf(&s
, "file_writeback %llu\n",
1431 (u64
)memcg_page_state(memcg
, NR_WRITEBACK
) *
1435 * TODO: We should eventually replace our own MEMCG_RSS_HUGE counter
1436 * with the NR_ANON_THP vm counter, but right now it's a pain in the
1437 * arse because it requires migrating the work out of rmap to a place
1438 * where the page->mem_cgroup is set up and stable.
1440 seq_buf_printf(&s
, "anon_thp %llu\n",
1441 (u64
)memcg_page_state(memcg
, MEMCG_RSS_HUGE
) *
1444 for (i
= 0; i
< NR_LRU_LISTS
; i
++)
1445 seq_buf_printf(&s
, "%s %llu\n", mem_cgroup_lru_names
[i
],
1446 (u64
)memcg_page_state(memcg
, NR_LRU_BASE
+ i
) *
1449 seq_buf_printf(&s
, "slab_reclaimable %llu\n",
1450 (u64
)memcg_page_state(memcg
, NR_SLAB_RECLAIMABLE
) *
1452 seq_buf_printf(&s
, "slab_unreclaimable %llu\n",
1453 (u64
)memcg_page_state(memcg
, NR_SLAB_UNRECLAIMABLE
) *
1456 /* Accumulated memory events */
1458 seq_buf_printf(&s
, "pgfault %lu\n", memcg_events(memcg
, PGFAULT
));
1459 seq_buf_printf(&s
, "pgmajfault %lu\n", memcg_events(memcg
, PGMAJFAULT
));
1461 seq_buf_printf(&s
, "workingset_refault %lu\n",
1462 memcg_page_state(memcg
, WORKINGSET_REFAULT
));
1463 seq_buf_printf(&s
, "workingset_activate %lu\n",
1464 memcg_page_state(memcg
, WORKINGSET_ACTIVATE
));
1465 seq_buf_printf(&s
, "workingset_nodereclaim %lu\n",
1466 memcg_page_state(memcg
, WORKINGSET_NODERECLAIM
));
1468 seq_buf_printf(&s
, "pgrefill %lu\n", memcg_events(memcg
, PGREFILL
));
1469 seq_buf_printf(&s
, "pgscan %lu\n",
1470 memcg_events(memcg
, PGSCAN_KSWAPD
) +
1471 memcg_events(memcg
, PGSCAN_DIRECT
));
1472 seq_buf_printf(&s
, "pgsteal %lu\n",
1473 memcg_events(memcg
, PGSTEAL_KSWAPD
) +
1474 memcg_events(memcg
, PGSTEAL_DIRECT
));
1475 seq_buf_printf(&s
, "pgactivate %lu\n", memcg_events(memcg
, PGACTIVATE
));
1476 seq_buf_printf(&s
, "pgdeactivate %lu\n", memcg_events(memcg
, PGDEACTIVATE
));
1477 seq_buf_printf(&s
, "pglazyfree %lu\n", memcg_events(memcg
, PGLAZYFREE
));
1478 seq_buf_printf(&s
, "pglazyfreed %lu\n", memcg_events(memcg
, PGLAZYFREED
));
1480 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
1481 seq_buf_printf(&s
, "thp_fault_alloc %lu\n",
1482 memcg_events(memcg
, THP_FAULT_ALLOC
));
1483 seq_buf_printf(&s
, "thp_collapse_alloc %lu\n",
1484 memcg_events(memcg
, THP_COLLAPSE_ALLOC
));
1485 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
1487 /* The above should easily fit into one page */
1488 WARN_ON_ONCE(seq_buf_has_overflowed(&s
));
1493 #define K(x) ((x) << (PAGE_SHIFT-10))
1495 * mem_cgroup_print_oom_context: Print OOM information relevant to
1496 * memory controller.
1497 * @memcg: The memory cgroup that went over limit
1498 * @p: Task that is going to be killed
1500 * NOTE: @memcg and @p's mem_cgroup can be different when hierarchy is
1503 void mem_cgroup_print_oom_context(struct mem_cgroup
*memcg
, struct task_struct
*p
)
1508 pr_cont(",oom_memcg=");
1509 pr_cont_cgroup_path(memcg
->css
.cgroup
);
1511 pr_cont(",global_oom");
1513 pr_cont(",task_memcg=");
1514 pr_cont_cgroup_path(task_cgroup(p
, memory_cgrp_id
));
1520 * mem_cgroup_print_oom_meminfo: Print OOM memory information relevant to
1521 * memory controller.
1522 * @memcg: The memory cgroup that went over limit
1524 void mem_cgroup_print_oom_meminfo(struct mem_cgroup
*memcg
)
1528 pr_info("memory: usage %llukB, limit %llukB, failcnt %lu\n",
1529 K((u64
)page_counter_read(&memcg
->memory
)),
1530 K((u64
)memcg
->memory
.max
), memcg
->memory
.failcnt
);
1531 if (cgroup_subsys_on_dfl(memory_cgrp_subsys
))
1532 pr_info("swap: usage %llukB, limit %llukB, failcnt %lu\n",
1533 K((u64
)page_counter_read(&memcg
->swap
)),
1534 K((u64
)memcg
->swap
.max
), memcg
->swap
.failcnt
);
1536 pr_info("memory+swap: usage %llukB, limit %llukB, failcnt %lu\n",
1537 K((u64
)page_counter_read(&memcg
->memsw
)),
1538 K((u64
)memcg
->memsw
.max
), memcg
->memsw
.failcnt
);
1539 pr_info("kmem: usage %llukB, limit %llukB, failcnt %lu\n",
1540 K((u64
)page_counter_read(&memcg
->kmem
)),
1541 K((u64
)memcg
->kmem
.max
), memcg
->kmem
.failcnt
);
1544 pr_info("Memory cgroup stats for ");
1545 pr_cont_cgroup_path(memcg
->css
.cgroup
);
1547 buf
= memory_stat_format(memcg
);
1555 * Return the memory (and swap, if configured) limit for a memcg.
1557 unsigned long mem_cgroup_get_max(struct mem_cgroup
*memcg
)
1561 max
= memcg
->memory
.max
;
1562 if (mem_cgroup_swappiness(memcg
)) {
1563 unsigned long memsw_max
;
1564 unsigned long swap_max
;
1566 memsw_max
= memcg
->memsw
.max
;
1567 swap_max
= memcg
->swap
.max
;
1568 swap_max
= min(swap_max
, (unsigned long)total_swap_pages
);
1569 max
= min(max
+ swap_max
, memsw_max
);
1574 static bool mem_cgroup_out_of_memory(struct mem_cgroup
*memcg
, gfp_t gfp_mask
,
1577 struct oom_control oc
= {
1581 .gfp_mask
= gfp_mask
,
1586 if (mutex_lock_killable(&oom_lock
))
1589 * A few threads which were not waiting at mutex_lock_killable() can
1590 * fail to bail out. Therefore, check again after holding oom_lock.
1592 ret
= should_force_charge() || out_of_memory(&oc
);
1593 mutex_unlock(&oom_lock
);
1597 #if MAX_NUMNODES > 1
1600 * test_mem_cgroup_node_reclaimable
1601 * @memcg: the target memcg
1602 * @nid: the node ID to be checked.
1603 * @noswap : specify true here if the user wants flle only information.
1605 * This function returns whether the specified memcg contains any
1606 * reclaimable pages on a node. Returns true if there are any reclaimable
1607 * pages in the node.
1609 static bool test_mem_cgroup_node_reclaimable(struct mem_cgroup
*memcg
,
1610 int nid
, bool noswap
)
1612 struct lruvec
*lruvec
= mem_cgroup_lruvec(NODE_DATA(nid
), memcg
);
1614 if (lruvec_page_state(lruvec
, NR_INACTIVE_FILE
) ||
1615 lruvec_page_state(lruvec
, NR_ACTIVE_FILE
))
1617 if (noswap
|| !total_swap_pages
)
1619 if (lruvec_page_state(lruvec
, NR_INACTIVE_ANON
) ||
1620 lruvec_page_state(lruvec
, NR_ACTIVE_ANON
))
1627 * Always updating the nodemask is not very good - even if we have an empty
1628 * list or the wrong list here, we can start from some node and traverse all
1629 * nodes based on the zonelist. So update the list loosely once per 10 secs.
1632 static void mem_cgroup_may_update_nodemask(struct mem_cgroup
*memcg
)
1636 * numainfo_events > 0 means there was at least NUMAINFO_EVENTS_TARGET
1637 * pagein/pageout changes since the last update.
1639 if (!atomic_read(&memcg
->numainfo_events
))
1641 if (atomic_inc_return(&memcg
->numainfo_updating
) > 1)
1644 /* make a nodemask where this memcg uses memory from */
1645 memcg
->scan_nodes
= node_states
[N_MEMORY
];
1647 for_each_node_mask(nid
, node_states
[N_MEMORY
]) {
1649 if (!test_mem_cgroup_node_reclaimable(memcg
, nid
, false))
1650 node_clear(nid
, memcg
->scan_nodes
);
1653 atomic_set(&memcg
->numainfo_events
, 0);
1654 atomic_set(&memcg
->numainfo_updating
, 0);
1658 * Selecting a node where we start reclaim from. Because what we need is just
1659 * reducing usage counter, start from anywhere is O,K. Considering
1660 * memory reclaim from current node, there are pros. and cons.
1662 * Freeing memory from current node means freeing memory from a node which
1663 * we'll use or we've used. So, it may make LRU bad. And if several threads
1664 * hit limits, it will see a contention on a node. But freeing from remote
1665 * node means more costs for memory reclaim because of memory latency.
1667 * Now, we use round-robin. Better algorithm is welcomed.
1669 int mem_cgroup_select_victim_node(struct mem_cgroup
*memcg
)
1673 mem_cgroup_may_update_nodemask(memcg
);
1674 node
= memcg
->last_scanned_node
;
1676 node
= next_node_in(node
, memcg
->scan_nodes
);
1678 * mem_cgroup_may_update_nodemask might have seen no reclaimmable pages
1679 * last time it really checked all the LRUs due to rate limiting.
1680 * Fallback to the current node in that case for simplicity.
1682 if (unlikely(node
== MAX_NUMNODES
))
1683 node
= numa_node_id();
1685 memcg
->last_scanned_node
= node
;
1689 int mem_cgroup_select_victim_node(struct mem_cgroup
*memcg
)
1695 static int mem_cgroup_soft_reclaim(struct mem_cgroup
*root_memcg
,
1698 unsigned long *total_scanned
)
1700 struct mem_cgroup
*victim
= NULL
;
1703 unsigned long excess
;
1704 unsigned long nr_scanned
;
1705 struct mem_cgroup_reclaim_cookie reclaim
= {
1710 excess
= soft_limit_excess(root_memcg
);
1713 victim
= mem_cgroup_iter(root_memcg
, victim
, &reclaim
);
1718 * If we have not been able to reclaim
1719 * anything, it might because there are
1720 * no reclaimable pages under this hierarchy
1725 * We want to do more targeted reclaim.
1726 * excess >> 2 is not to excessive so as to
1727 * reclaim too much, nor too less that we keep
1728 * coming back to reclaim from this cgroup
1730 if (total
>= (excess
>> 2) ||
1731 (loop
> MEM_CGROUP_MAX_RECLAIM_LOOPS
))
1736 total
+= mem_cgroup_shrink_node(victim
, gfp_mask
, false,
1737 pgdat
, &nr_scanned
);
1738 *total_scanned
+= nr_scanned
;
1739 if (!soft_limit_excess(root_memcg
))
1742 mem_cgroup_iter_break(root_memcg
, victim
);
1746 #ifdef CONFIG_LOCKDEP
1747 static struct lockdep_map memcg_oom_lock_dep_map
= {
1748 .name
= "memcg_oom_lock",
1752 static DEFINE_SPINLOCK(memcg_oom_lock
);
1755 * Check OOM-Killer is already running under our hierarchy.
1756 * If someone is running, return false.
1758 static bool mem_cgroup_oom_trylock(struct mem_cgroup
*memcg
)
1760 struct mem_cgroup
*iter
, *failed
= NULL
;
1762 spin_lock(&memcg_oom_lock
);
1764 for_each_mem_cgroup_tree(iter
, memcg
) {
1765 if (iter
->oom_lock
) {
1767 * this subtree of our hierarchy is already locked
1768 * so we cannot give a lock.
1771 mem_cgroup_iter_break(memcg
, iter
);
1774 iter
->oom_lock
= true;
1779 * OK, we failed to lock the whole subtree so we have
1780 * to clean up what we set up to the failing subtree
1782 for_each_mem_cgroup_tree(iter
, memcg
) {
1783 if (iter
== failed
) {
1784 mem_cgroup_iter_break(memcg
, iter
);
1787 iter
->oom_lock
= false;
1790 mutex_acquire(&memcg_oom_lock_dep_map
, 0, 1, _RET_IP_
);
1792 spin_unlock(&memcg_oom_lock
);
1797 static void mem_cgroup_oom_unlock(struct mem_cgroup
*memcg
)
1799 struct mem_cgroup
*iter
;
1801 spin_lock(&memcg_oom_lock
);
1802 mutex_release(&memcg_oom_lock_dep_map
, 1, _RET_IP_
);
1803 for_each_mem_cgroup_tree(iter
, memcg
)
1804 iter
->oom_lock
= false;
1805 spin_unlock(&memcg_oom_lock
);
1808 static void mem_cgroup_mark_under_oom(struct mem_cgroup
*memcg
)
1810 struct mem_cgroup
*iter
;
1812 spin_lock(&memcg_oom_lock
);
1813 for_each_mem_cgroup_tree(iter
, memcg
)
1815 spin_unlock(&memcg_oom_lock
);
1818 static void mem_cgroup_unmark_under_oom(struct mem_cgroup
*memcg
)
1820 struct mem_cgroup
*iter
;
1823 * When a new child is created while the hierarchy is under oom,
1824 * mem_cgroup_oom_lock() may not be called. Watch for underflow.
1826 spin_lock(&memcg_oom_lock
);
1827 for_each_mem_cgroup_tree(iter
, memcg
)
1828 if (iter
->under_oom
> 0)
1830 spin_unlock(&memcg_oom_lock
);
1833 static DECLARE_WAIT_QUEUE_HEAD(memcg_oom_waitq
);
1835 struct oom_wait_info
{
1836 struct mem_cgroup
*memcg
;
1837 wait_queue_entry_t wait
;
1840 static int memcg_oom_wake_function(wait_queue_entry_t
*wait
,
1841 unsigned mode
, int sync
, void *arg
)
1843 struct mem_cgroup
*wake_memcg
= (struct mem_cgroup
*)arg
;
1844 struct mem_cgroup
*oom_wait_memcg
;
1845 struct oom_wait_info
*oom_wait_info
;
1847 oom_wait_info
= container_of(wait
, struct oom_wait_info
, wait
);
1848 oom_wait_memcg
= oom_wait_info
->memcg
;
1850 if (!mem_cgroup_is_descendant(wake_memcg
, oom_wait_memcg
) &&
1851 !mem_cgroup_is_descendant(oom_wait_memcg
, wake_memcg
))
1853 return autoremove_wake_function(wait
, mode
, sync
, arg
);
1856 static void memcg_oom_recover(struct mem_cgroup
*memcg
)
1859 * For the following lockless ->under_oom test, the only required
1860 * guarantee is that it must see the state asserted by an OOM when
1861 * this function is called as a result of userland actions
1862 * triggered by the notification of the OOM. This is trivially
1863 * achieved by invoking mem_cgroup_mark_under_oom() before
1864 * triggering notification.
1866 if (memcg
&& memcg
->under_oom
)
1867 __wake_up(&memcg_oom_waitq
, TASK_NORMAL
, 0, memcg
);
1877 static enum oom_status
mem_cgroup_oom(struct mem_cgroup
*memcg
, gfp_t mask
, int order
)
1879 enum oom_status ret
;
1882 if (order
> PAGE_ALLOC_COSTLY_ORDER
)
1885 memcg_memory_event(memcg
, MEMCG_OOM
);
1888 * We are in the middle of the charge context here, so we
1889 * don't want to block when potentially sitting on a callstack
1890 * that holds all kinds of filesystem and mm locks.
1892 * cgroup1 allows disabling the OOM killer and waiting for outside
1893 * handling until the charge can succeed; remember the context and put
1894 * the task to sleep at the end of the page fault when all locks are
1897 * On the other hand, in-kernel OOM killer allows for an async victim
1898 * memory reclaim (oom_reaper) and that means that we are not solely
1899 * relying on the oom victim to make a forward progress and we can
1900 * invoke the oom killer here.
1902 * Please note that mem_cgroup_out_of_memory might fail to find a
1903 * victim and then we have to bail out from the charge path.
1905 if (memcg
->oom_kill_disable
) {
1906 if (!current
->in_user_fault
)
1908 css_get(&memcg
->css
);
1909 current
->memcg_in_oom
= memcg
;
1910 current
->memcg_oom_gfp_mask
= mask
;
1911 current
->memcg_oom_order
= order
;
1916 mem_cgroup_mark_under_oom(memcg
);
1918 locked
= mem_cgroup_oom_trylock(memcg
);
1921 mem_cgroup_oom_notify(memcg
);
1923 mem_cgroup_unmark_under_oom(memcg
);
1924 if (mem_cgroup_out_of_memory(memcg
, mask
, order
))
1930 mem_cgroup_oom_unlock(memcg
);
1936 * mem_cgroup_oom_synchronize - complete memcg OOM handling
1937 * @handle: actually kill/wait or just clean up the OOM state
1939 * This has to be called at the end of a page fault if the memcg OOM
1940 * handler was enabled.
1942 * Memcg supports userspace OOM handling where failed allocations must
1943 * sleep on a waitqueue until the userspace task resolves the
1944 * situation. Sleeping directly in the charge context with all kinds
1945 * of locks held is not a good idea, instead we remember an OOM state
1946 * in the task and mem_cgroup_oom_synchronize() has to be called at
1947 * the end of the page fault to complete the OOM handling.
1949 * Returns %true if an ongoing memcg OOM situation was detected and
1950 * completed, %false otherwise.
1952 bool mem_cgroup_oom_synchronize(bool handle
)
1954 struct mem_cgroup
*memcg
= current
->memcg_in_oom
;
1955 struct oom_wait_info owait
;
1958 /* OOM is global, do not handle */
1965 owait
.memcg
= memcg
;
1966 owait
.wait
.flags
= 0;
1967 owait
.wait
.func
= memcg_oom_wake_function
;
1968 owait
.wait
.private = current
;
1969 INIT_LIST_HEAD(&owait
.wait
.entry
);
1971 prepare_to_wait(&memcg_oom_waitq
, &owait
.wait
, TASK_KILLABLE
);
1972 mem_cgroup_mark_under_oom(memcg
);
1974 locked
= mem_cgroup_oom_trylock(memcg
);
1977 mem_cgroup_oom_notify(memcg
);
1979 if (locked
&& !memcg
->oom_kill_disable
) {
1980 mem_cgroup_unmark_under_oom(memcg
);
1981 finish_wait(&memcg_oom_waitq
, &owait
.wait
);
1982 mem_cgroup_out_of_memory(memcg
, current
->memcg_oom_gfp_mask
,
1983 current
->memcg_oom_order
);
1986 mem_cgroup_unmark_under_oom(memcg
);
1987 finish_wait(&memcg_oom_waitq
, &owait
.wait
);
1991 mem_cgroup_oom_unlock(memcg
);
1993 * There is no guarantee that an OOM-lock contender
1994 * sees the wakeups triggered by the OOM kill
1995 * uncharges. Wake any sleepers explicitely.
1997 memcg_oom_recover(memcg
);
2000 current
->memcg_in_oom
= NULL
;
2001 css_put(&memcg
->css
);
2006 * mem_cgroup_get_oom_group - get a memory cgroup to clean up after OOM
2007 * @victim: task to be killed by the OOM killer
2008 * @oom_domain: memcg in case of memcg OOM, NULL in case of system-wide OOM
2010 * Returns a pointer to a memory cgroup, which has to be cleaned up
2011 * by killing all belonging OOM-killable tasks.
2013 * Caller has to call mem_cgroup_put() on the returned non-NULL memcg.
2015 struct mem_cgroup
*mem_cgroup_get_oom_group(struct task_struct
*victim
,
2016 struct mem_cgroup
*oom_domain
)
2018 struct mem_cgroup
*oom_group
= NULL
;
2019 struct mem_cgroup
*memcg
;
2021 if (!cgroup_subsys_on_dfl(memory_cgrp_subsys
))
2025 oom_domain
= root_mem_cgroup
;
2029 memcg
= mem_cgroup_from_task(victim
);
2030 if (memcg
== root_mem_cgroup
)
2034 * Traverse the memory cgroup hierarchy from the victim task's
2035 * cgroup up to the OOMing cgroup (or root) to find the
2036 * highest-level memory cgroup with oom.group set.
2038 for (; memcg
; memcg
= parent_mem_cgroup(memcg
)) {
2039 if (memcg
->oom_group
)
2042 if (memcg
== oom_domain
)
2047 css_get(&oom_group
->css
);
2054 void mem_cgroup_print_oom_group(struct mem_cgroup
*memcg
)
2056 pr_info("Tasks in ");
2057 pr_cont_cgroup_path(memcg
->css
.cgroup
);
2058 pr_cont(" are going to be killed due to memory.oom.group set\n");
2062 * lock_page_memcg - lock a page->mem_cgroup binding
2065 * This function protects unlocked LRU pages from being moved to
2068 * It ensures lifetime of the returned memcg. Caller is responsible
2069 * for the lifetime of the page; __unlock_page_memcg() is available
2070 * when @page might get freed inside the locked section.
2072 struct mem_cgroup
*lock_page_memcg(struct page
*page
)
2074 struct mem_cgroup
*memcg
;
2075 unsigned long flags
;
2078 * The RCU lock is held throughout the transaction. The fast
2079 * path can get away without acquiring the memcg->move_lock
2080 * because page moving starts with an RCU grace period.
2082 * The RCU lock also protects the memcg from being freed when
2083 * the page state that is going to change is the only thing
2084 * preventing the page itself from being freed. E.g. writeback
2085 * doesn't hold a page reference and relies on PG_writeback to
2086 * keep off truncation, migration and so forth.
2090 if (mem_cgroup_disabled())
2093 memcg
= page
->mem_cgroup
;
2094 if (unlikely(!memcg
))
2097 if (atomic_read(&memcg
->moving_account
) <= 0)
2100 spin_lock_irqsave(&memcg
->move_lock
, flags
);
2101 if (memcg
!= page
->mem_cgroup
) {
2102 spin_unlock_irqrestore(&memcg
->move_lock
, flags
);
2107 * When charge migration first begins, we can have locked and
2108 * unlocked page stat updates happening concurrently. Track
2109 * the task who has the lock for unlock_page_memcg().
2111 memcg
->move_lock_task
= current
;
2112 memcg
->move_lock_flags
= flags
;
2116 EXPORT_SYMBOL(lock_page_memcg
);
2119 * __unlock_page_memcg - unlock and unpin a memcg
2122 * Unlock and unpin a memcg returned by lock_page_memcg().
2124 void __unlock_page_memcg(struct mem_cgroup
*memcg
)
2126 if (memcg
&& memcg
->move_lock_task
== current
) {
2127 unsigned long flags
= memcg
->move_lock_flags
;
2129 memcg
->move_lock_task
= NULL
;
2130 memcg
->move_lock_flags
= 0;
2132 spin_unlock_irqrestore(&memcg
->move_lock
, flags
);
2139 * unlock_page_memcg - unlock a page->mem_cgroup binding
2142 void unlock_page_memcg(struct page
*page
)
2144 __unlock_page_memcg(page
->mem_cgroup
);
2146 EXPORT_SYMBOL(unlock_page_memcg
);
2148 struct memcg_stock_pcp
{
2149 struct mem_cgroup
*cached
; /* this never be root cgroup */
2150 unsigned int nr_pages
;
2151 struct work_struct work
;
2152 unsigned long flags
;
2153 #define FLUSHING_CACHED_CHARGE 0
2155 static DEFINE_PER_CPU(struct memcg_stock_pcp
, memcg_stock
);
2156 static DEFINE_MUTEX(percpu_charge_mutex
);
2159 * consume_stock: Try to consume stocked charge on this cpu.
2160 * @memcg: memcg to consume from.
2161 * @nr_pages: how many pages to charge.
2163 * The charges will only happen if @memcg matches the current cpu's memcg
2164 * stock, and at least @nr_pages are available in that stock. Failure to
2165 * service an allocation will refill the stock.
2167 * returns true if successful, false otherwise.
2169 static bool consume_stock(struct mem_cgroup
*memcg
, unsigned int nr_pages
)
2171 struct memcg_stock_pcp
*stock
;
2172 unsigned long flags
;
2175 if (nr_pages
> MEMCG_CHARGE_BATCH
)
2178 local_irq_save(flags
);
2180 stock
= this_cpu_ptr(&memcg_stock
);
2181 if (memcg
== stock
->cached
&& stock
->nr_pages
>= nr_pages
) {
2182 stock
->nr_pages
-= nr_pages
;
2186 local_irq_restore(flags
);
2192 * Returns stocks cached in percpu and reset cached information.
2194 static void drain_stock(struct memcg_stock_pcp
*stock
)
2196 struct mem_cgroup
*old
= stock
->cached
;
2198 if (stock
->nr_pages
) {
2199 page_counter_uncharge(&old
->memory
, stock
->nr_pages
);
2200 if (do_memsw_account())
2201 page_counter_uncharge(&old
->memsw
, stock
->nr_pages
);
2202 css_put_many(&old
->css
, stock
->nr_pages
);
2203 stock
->nr_pages
= 0;
2205 stock
->cached
= NULL
;
2208 static void drain_local_stock(struct work_struct
*dummy
)
2210 struct memcg_stock_pcp
*stock
;
2211 unsigned long flags
;
2214 * The only protection from memory hotplug vs. drain_stock races is
2215 * that we always operate on local CPU stock here with IRQ disabled
2217 local_irq_save(flags
);
2219 stock
= this_cpu_ptr(&memcg_stock
);
2221 clear_bit(FLUSHING_CACHED_CHARGE
, &stock
->flags
);
2223 local_irq_restore(flags
);
2227 * Cache charges(val) to local per_cpu area.
2228 * This will be consumed by consume_stock() function, later.
2230 static void refill_stock(struct mem_cgroup
*memcg
, unsigned int nr_pages
)
2232 struct memcg_stock_pcp
*stock
;
2233 unsigned long flags
;
2235 local_irq_save(flags
);
2237 stock
= this_cpu_ptr(&memcg_stock
);
2238 if (stock
->cached
!= memcg
) { /* reset if necessary */
2240 stock
->cached
= memcg
;
2242 stock
->nr_pages
+= nr_pages
;
2244 if (stock
->nr_pages
> MEMCG_CHARGE_BATCH
)
2247 local_irq_restore(flags
);
2251 * Drains all per-CPU charge caches for given root_memcg resp. subtree
2252 * of the hierarchy under it.
2254 static void drain_all_stock(struct mem_cgroup
*root_memcg
)
2258 /* If someone's already draining, avoid adding running more workers. */
2259 if (!mutex_trylock(&percpu_charge_mutex
))
2262 * Notify other cpus that system-wide "drain" is running
2263 * We do not care about races with the cpu hotplug because cpu down
2264 * as well as workers from this path always operate on the local
2265 * per-cpu data. CPU up doesn't touch memcg_stock at all.
2268 for_each_online_cpu(cpu
) {
2269 struct memcg_stock_pcp
*stock
= &per_cpu(memcg_stock
, cpu
);
2270 struct mem_cgroup
*memcg
;
2272 memcg
= stock
->cached
;
2273 if (!memcg
|| !stock
->nr_pages
|| !css_tryget(&memcg
->css
))
2275 if (!mem_cgroup_is_descendant(memcg
, root_memcg
)) {
2276 css_put(&memcg
->css
);
2279 if (!test_and_set_bit(FLUSHING_CACHED_CHARGE
, &stock
->flags
)) {
2281 drain_local_stock(&stock
->work
);
2283 schedule_work_on(cpu
, &stock
->work
);
2285 css_put(&memcg
->css
);
2288 mutex_unlock(&percpu_charge_mutex
);
2291 static int memcg_hotplug_cpu_dead(unsigned int cpu
)
2293 struct memcg_stock_pcp
*stock
;
2294 struct mem_cgroup
*memcg
, *mi
;
2296 stock
= &per_cpu(memcg_stock
, cpu
);
2299 for_each_mem_cgroup(memcg
) {
2302 for (i
= 0; i
< MEMCG_NR_STAT
; i
++) {
2306 x
= this_cpu_xchg(memcg
->vmstats_percpu
->stat
[i
], 0);
2308 for (mi
= memcg
; mi
; mi
= parent_mem_cgroup(mi
))
2309 atomic_long_add(x
, &memcg
->vmstats
[i
]);
2311 if (i
>= NR_VM_NODE_STAT_ITEMS
)
2314 for_each_node(nid
) {
2315 struct mem_cgroup_per_node
*pn
;
2317 pn
= mem_cgroup_nodeinfo(memcg
, nid
);
2318 x
= this_cpu_xchg(pn
->lruvec_stat_cpu
->count
[i
], 0);
2321 atomic_long_add(x
, &pn
->lruvec_stat
[i
]);
2322 } while ((pn
= parent_nodeinfo(pn
, nid
)));
2326 for (i
= 0; i
< NR_VM_EVENT_ITEMS
; i
++) {
2329 x
= this_cpu_xchg(memcg
->vmstats_percpu
->events
[i
], 0);
2331 for (mi
= memcg
; mi
; mi
= parent_mem_cgroup(mi
))
2332 atomic_long_add(x
, &memcg
->vmevents
[i
]);
2339 static void reclaim_high(struct mem_cgroup
*memcg
,
2340 unsigned int nr_pages
,
2344 if (page_counter_read(&memcg
->memory
) <= memcg
->high
)
2346 memcg_memory_event(memcg
, MEMCG_HIGH
);
2347 try_to_free_mem_cgroup_pages(memcg
, nr_pages
, gfp_mask
, true);
2348 } while ((memcg
= parent_mem_cgroup(memcg
)));
2351 static void high_work_func(struct work_struct
*work
)
2353 struct mem_cgroup
*memcg
;
2355 memcg
= container_of(work
, struct mem_cgroup
, high_work
);
2356 reclaim_high(memcg
, MEMCG_CHARGE_BATCH
, GFP_KERNEL
);
2360 * Scheduled by try_charge() to be executed from the userland return path
2361 * and reclaims memory over the high limit.
2363 void mem_cgroup_handle_over_high(void)
2365 unsigned int nr_pages
= current
->memcg_nr_pages_over_high
;
2366 struct mem_cgroup
*memcg
;
2368 if (likely(!nr_pages
))
2371 memcg
= get_mem_cgroup_from_mm(current
->mm
);
2372 reclaim_high(memcg
, nr_pages
, GFP_KERNEL
);
2373 css_put(&memcg
->css
);
2374 current
->memcg_nr_pages_over_high
= 0;
2377 static int try_charge(struct mem_cgroup
*memcg
, gfp_t gfp_mask
,
2378 unsigned int nr_pages
)
2380 unsigned int batch
= max(MEMCG_CHARGE_BATCH
, nr_pages
);
2381 int nr_retries
= MEM_CGROUP_RECLAIM_RETRIES
;
2382 struct mem_cgroup
*mem_over_limit
;
2383 struct page_counter
*counter
;
2384 unsigned long nr_reclaimed
;
2385 bool may_swap
= true;
2386 bool drained
= false;
2387 enum oom_status oom_status
;
2389 if (mem_cgroup_is_root(memcg
))
2392 if (consume_stock(memcg
, nr_pages
))
2395 if (!do_memsw_account() ||
2396 page_counter_try_charge(&memcg
->memsw
, batch
, &counter
)) {
2397 if (page_counter_try_charge(&memcg
->memory
, batch
, &counter
))
2399 if (do_memsw_account())
2400 page_counter_uncharge(&memcg
->memsw
, batch
);
2401 mem_over_limit
= mem_cgroup_from_counter(counter
, memory
);
2403 mem_over_limit
= mem_cgroup_from_counter(counter
, memsw
);
2407 if (batch
> nr_pages
) {
2413 * Unlike in global OOM situations, memcg is not in a physical
2414 * memory shortage. Allow dying and OOM-killed tasks to
2415 * bypass the last charges so that they can exit quickly and
2416 * free their memory.
2418 if (unlikely(should_force_charge()))
2422 * Prevent unbounded recursion when reclaim operations need to
2423 * allocate memory. This might exceed the limits temporarily,
2424 * but we prefer facilitating memory reclaim and getting back
2425 * under the limit over triggering OOM kills in these cases.
2427 if (unlikely(current
->flags
& PF_MEMALLOC
))
2430 if (unlikely(task_in_memcg_oom(current
)))
2433 if (!gfpflags_allow_blocking(gfp_mask
))
2436 memcg_memory_event(mem_over_limit
, MEMCG_MAX
);
2438 nr_reclaimed
= try_to_free_mem_cgroup_pages(mem_over_limit
, nr_pages
,
2439 gfp_mask
, may_swap
);
2441 if (mem_cgroup_margin(mem_over_limit
) >= nr_pages
)
2445 drain_all_stock(mem_over_limit
);
2450 if (gfp_mask
& __GFP_NORETRY
)
2453 * Even though the limit is exceeded at this point, reclaim
2454 * may have been able to free some pages. Retry the charge
2455 * before killing the task.
2457 * Only for regular pages, though: huge pages are rather
2458 * unlikely to succeed so close to the limit, and we fall back
2459 * to regular pages anyway in case of failure.
2461 if (nr_reclaimed
&& nr_pages
<= (1 << PAGE_ALLOC_COSTLY_ORDER
))
2464 * At task move, charge accounts can be doubly counted. So, it's
2465 * better to wait until the end of task_move if something is going on.
2467 if (mem_cgroup_wait_acct_move(mem_over_limit
))
2473 if (gfp_mask
& __GFP_RETRY_MAYFAIL
)
2476 if (gfp_mask
& __GFP_NOFAIL
)
2479 if (fatal_signal_pending(current
))
2483 * keep retrying as long as the memcg oom killer is able to make
2484 * a forward progress or bypass the charge if the oom killer
2485 * couldn't make any progress.
2487 oom_status
= mem_cgroup_oom(mem_over_limit
, gfp_mask
,
2488 get_order(nr_pages
* PAGE_SIZE
));
2489 switch (oom_status
) {
2491 nr_retries
= MEM_CGROUP_RECLAIM_RETRIES
;
2499 if (!(gfp_mask
& __GFP_NOFAIL
))
2503 * The allocation either can't fail or will lead to more memory
2504 * being freed very soon. Allow memory usage go over the limit
2505 * temporarily by force charging it.
2507 page_counter_charge(&memcg
->memory
, nr_pages
);
2508 if (do_memsw_account())
2509 page_counter_charge(&memcg
->memsw
, nr_pages
);
2510 css_get_many(&memcg
->css
, nr_pages
);
2515 css_get_many(&memcg
->css
, batch
);
2516 if (batch
> nr_pages
)
2517 refill_stock(memcg
, batch
- nr_pages
);
2520 * If the hierarchy is above the normal consumption range, schedule
2521 * reclaim on returning to userland. We can perform reclaim here
2522 * if __GFP_RECLAIM but let's always punt for simplicity and so that
2523 * GFP_KERNEL can consistently be used during reclaim. @memcg is
2524 * not recorded as it most likely matches current's and won't
2525 * change in the meantime. As high limit is checked again before
2526 * reclaim, the cost of mismatch is negligible.
2529 if (page_counter_read(&memcg
->memory
) > memcg
->high
) {
2530 /* Don't bother a random interrupted task */
2531 if (in_interrupt()) {
2532 schedule_work(&memcg
->high_work
);
2535 current
->memcg_nr_pages_over_high
+= batch
;
2536 set_notify_resume(current
);
2539 } while ((memcg
= parent_mem_cgroup(memcg
)));
2544 static void cancel_charge(struct mem_cgroup
*memcg
, unsigned int nr_pages
)
2546 if (mem_cgroup_is_root(memcg
))
2549 page_counter_uncharge(&memcg
->memory
, nr_pages
);
2550 if (do_memsw_account())
2551 page_counter_uncharge(&memcg
->memsw
, nr_pages
);
2553 css_put_many(&memcg
->css
, nr_pages
);
2556 static void lock_page_lru(struct page
*page
, int *isolated
)
2558 pg_data_t
*pgdat
= page_pgdat(page
);
2560 spin_lock_irq(&pgdat
->lru_lock
);
2561 if (PageLRU(page
)) {
2562 struct lruvec
*lruvec
;
2564 lruvec
= mem_cgroup_page_lruvec(page
, pgdat
);
2566 del_page_from_lru_list(page
, lruvec
, page_lru(page
));
2572 static void unlock_page_lru(struct page
*page
, int isolated
)
2574 pg_data_t
*pgdat
= page_pgdat(page
);
2577 struct lruvec
*lruvec
;
2579 lruvec
= mem_cgroup_page_lruvec(page
, pgdat
);
2580 VM_BUG_ON_PAGE(PageLRU(page
), page
);
2582 add_page_to_lru_list(page
, lruvec
, page_lru(page
));
2584 spin_unlock_irq(&pgdat
->lru_lock
);
2587 static void commit_charge(struct page
*page
, struct mem_cgroup
*memcg
,
2592 VM_BUG_ON_PAGE(page
->mem_cgroup
, page
);
2595 * In some cases, SwapCache and FUSE(splice_buf->radixtree), the page
2596 * may already be on some other mem_cgroup's LRU. Take care of it.
2599 lock_page_lru(page
, &isolated
);
2602 * Nobody should be changing or seriously looking at
2603 * page->mem_cgroup at this point:
2605 * - the page is uncharged
2607 * - the page is off-LRU
2609 * - an anonymous fault has exclusive page access, except for
2610 * a locked page table
2612 * - a page cache insertion, a swapin fault, or a migration
2613 * have the page locked
2615 page
->mem_cgroup
= memcg
;
2618 unlock_page_lru(page
, isolated
);
2621 #ifdef CONFIG_MEMCG_KMEM
2622 static int memcg_alloc_cache_id(void)
2627 id
= ida_simple_get(&memcg_cache_ida
,
2628 0, MEMCG_CACHES_MAX_SIZE
, GFP_KERNEL
);
2632 if (id
< memcg_nr_cache_ids
)
2636 * There's no space for the new id in memcg_caches arrays,
2637 * so we have to grow them.
2639 down_write(&memcg_cache_ids_sem
);
2641 size
= 2 * (id
+ 1);
2642 if (size
< MEMCG_CACHES_MIN_SIZE
)
2643 size
= MEMCG_CACHES_MIN_SIZE
;
2644 else if (size
> MEMCG_CACHES_MAX_SIZE
)
2645 size
= MEMCG_CACHES_MAX_SIZE
;
2647 err
= memcg_update_all_caches(size
);
2649 err
= memcg_update_all_list_lrus(size
);
2651 memcg_nr_cache_ids
= size
;
2653 up_write(&memcg_cache_ids_sem
);
2656 ida_simple_remove(&memcg_cache_ida
, id
);
2662 static void memcg_free_cache_id(int id
)
2664 ida_simple_remove(&memcg_cache_ida
, id
);
2667 struct memcg_kmem_cache_create_work
{
2668 struct mem_cgroup
*memcg
;
2669 struct kmem_cache
*cachep
;
2670 struct work_struct work
;
2673 static void memcg_kmem_cache_create_func(struct work_struct
*w
)
2675 struct memcg_kmem_cache_create_work
*cw
=
2676 container_of(w
, struct memcg_kmem_cache_create_work
, work
);
2677 struct mem_cgroup
*memcg
= cw
->memcg
;
2678 struct kmem_cache
*cachep
= cw
->cachep
;
2680 memcg_create_kmem_cache(memcg
, cachep
);
2682 css_put(&memcg
->css
);
2687 * Enqueue the creation of a per-memcg kmem_cache.
2689 static void memcg_schedule_kmem_cache_create(struct mem_cgroup
*memcg
,
2690 struct kmem_cache
*cachep
)
2692 struct memcg_kmem_cache_create_work
*cw
;
2694 if (!css_tryget_online(&memcg
->css
))
2697 cw
= kmalloc(sizeof(*cw
), GFP_NOWAIT
| __GFP_NOWARN
);
2702 cw
->cachep
= cachep
;
2703 INIT_WORK(&cw
->work
, memcg_kmem_cache_create_func
);
2705 queue_work(memcg_kmem_cache_wq
, &cw
->work
);
2708 static inline bool memcg_kmem_bypass(void)
2710 if (in_interrupt() || !current
->mm
|| (current
->flags
& PF_KTHREAD
))
2716 * memcg_kmem_get_cache: select the correct per-memcg cache for allocation
2717 * @cachep: the original global kmem cache
2719 * Return the kmem_cache we're supposed to use for a slab allocation.
2720 * We try to use the current memcg's version of the cache.
2722 * If the cache does not exist yet, if we are the first user of it, we
2723 * create it asynchronously in a workqueue and let the current allocation
2724 * go through with the original cache.
2726 * This function takes a reference to the cache it returns to assure it
2727 * won't get destroyed while we are working with it. Once the caller is
2728 * done with it, memcg_kmem_put_cache() must be called to release the
2731 struct kmem_cache
*memcg_kmem_get_cache(struct kmem_cache
*cachep
)
2733 struct mem_cgroup
*memcg
;
2734 struct kmem_cache
*memcg_cachep
;
2735 struct memcg_cache_array
*arr
;
2738 VM_BUG_ON(!is_root_cache(cachep
));
2740 if (memcg_kmem_bypass())
2745 if (unlikely(current
->active_memcg
))
2746 memcg
= current
->active_memcg
;
2748 memcg
= mem_cgroup_from_task(current
);
2750 if (!memcg
|| memcg
== root_mem_cgroup
)
2753 kmemcg_id
= READ_ONCE(memcg
->kmemcg_id
);
2757 arr
= rcu_dereference(cachep
->memcg_params
.memcg_caches
);
2760 * Make sure we will access the up-to-date value. The code updating
2761 * memcg_caches issues a write barrier to match the data dependency
2762 * barrier inside READ_ONCE() (see memcg_create_kmem_cache()).
2764 memcg_cachep
= READ_ONCE(arr
->entries
[kmemcg_id
]);
2767 * If we are in a safe context (can wait, and not in interrupt
2768 * context), we could be be predictable and return right away.
2769 * This would guarantee that the allocation being performed
2770 * already belongs in the new cache.
2772 * However, there are some clashes that can arrive from locking.
2773 * For instance, because we acquire the slab_mutex while doing
2774 * memcg_create_kmem_cache, this means no further allocation
2775 * could happen with the slab_mutex held. So it's better to
2778 * If the memcg is dying or memcg_cache is about to be released,
2779 * don't bother creating new kmem_caches. Because memcg_cachep
2780 * is ZEROed as the fist step of kmem offlining, we don't need
2781 * percpu_ref_tryget_live() here. css_tryget_online() check in
2782 * memcg_schedule_kmem_cache_create() will prevent us from
2783 * creation of a new kmem_cache.
2785 if (unlikely(!memcg_cachep
))
2786 memcg_schedule_kmem_cache_create(memcg
, cachep
);
2787 else if (percpu_ref_tryget(&memcg_cachep
->memcg_params
.refcnt
))
2788 cachep
= memcg_cachep
;
2795 * memcg_kmem_put_cache: drop reference taken by memcg_kmem_get_cache
2796 * @cachep: the cache returned by memcg_kmem_get_cache
2798 void memcg_kmem_put_cache(struct kmem_cache
*cachep
)
2800 if (!is_root_cache(cachep
))
2801 percpu_ref_put(&cachep
->memcg_params
.refcnt
);
2805 * __memcg_kmem_charge_memcg: charge a kmem page
2806 * @page: page to charge
2807 * @gfp: reclaim mode
2808 * @order: allocation order
2809 * @memcg: memory cgroup to charge
2811 * Returns 0 on success, an error code on failure.
2813 int __memcg_kmem_charge_memcg(struct page
*page
, gfp_t gfp
, int order
,
2814 struct mem_cgroup
*memcg
)
2816 unsigned int nr_pages
= 1 << order
;
2817 struct page_counter
*counter
;
2820 ret
= try_charge(memcg
, gfp
, nr_pages
);
2824 if (!cgroup_subsys_on_dfl(memory_cgrp_subsys
) &&
2825 !page_counter_try_charge(&memcg
->kmem
, nr_pages
, &counter
)) {
2826 cancel_charge(memcg
, nr_pages
);
2833 * __memcg_kmem_charge: charge a kmem page to the current memory cgroup
2834 * @page: page to charge
2835 * @gfp: reclaim mode
2836 * @order: allocation order
2838 * Returns 0 on success, an error code on failure.
2840 int __memcg_kmem_charge(struct page
*page
, gfp_t gfp
, int order
)
2842 struct mem_cgroup
*memcg
;
2845 if (memcg_kmem_bypass())
2848 memcg
= get_mem_cgroup_from_current();
2849 if (!mem_cgroup_is_root(memcg
)) {
2850 ret
= __memcg_kmem_charge_memcg(page
, gfp
, order
, memcg
);
2852 page
->mem_cgroup
= memcg
;
2853 __SetPageKmemcg(page
);
2856 css_put(&memcg
->css
);
2861 * __memcg_kmem_uncharge_memcg: uncharge a kmem page
2862 * @memcg: memcg to uncharge
2863 * @nr_pages: number of pages to uncharge
2865 void __memcg_kmem_uncharge_memcg(struct mem_cgroup
*memcg
,
2866 unsigned int nr_pages
)
2868 if (!cgroup_subsys_on_dfl(memory_cgrp_subsys
))
2869 page_counter_uncharge(&memcg
->kmem
, nr_pages
);
2871 page_counter_uncharge(&memcg
->memory
, nr_pages
);
2872 if (do_memsw_account())
2873 page_counter_uncharge(&memcg
->memsw
, nr_pages
);
2876 * __memcg_kmem_uncharge: uncharge a kmem page
2877 * @page: page to uncharge
2878 * @order: allocation order
2880 void __memcg_kmem_uncharge(struct page
*page
, int order
)
2882 struct mem_cgroup
*memcg
= page
->mem_cgroup
;
2883 unsigned int nr_pages
= 1 << order
;
2888 VM_BUG_ON_PAGE(mem_cgroup_is_root(memcg
), page
);
2889 __memcg_kmem_uncharge_memcg(memcg
, nr_pages
);
2890 page
->mem_cgroup
= NULL
;
2892 /* slab pages do not have PageKmemcg flag set */
2893 if (PageKmemcg(page
))
2894 __ClearPageKmemcg(page
);
2896 css_put_many(&memcg
->css
, nr_pages
);
2898 #endif /* CONFIG_MEMCG_KMEM */
2900 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
2903 * Because tail pages are not marked as "used", set it. We're under
2904 * pgdat->lru_lock and migration entries setup in all page mappings.
2906 void mem_cgroup_split_huge_fixup(struct page
*head
)
2910 if (mem_cgroup_disabled())
2913 for (i
= 1; i
< HPAGE_PMD_NR
; i
++)
2914 head
[i
].mem_cgroup
= head
->mem_cgroup
;
2916 __mod_memcg_state(head
->mem_cgroup
, MEMCG_RSS_HUGE
, -HPAGE_PMD_NR
);
2918 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
2920 #ifdef CONFIG_MEMCG_SWAP
2922 * mem_cgroup_move_swap_account - move swap charge and swap_cgroup's record.
2923 * @entry: swap entry to be moved
2924 * @from: mem_cgroup which the entry is moved from
2925 * @to: mem_cgroup which the entry is moved to
2927 * It succeeds only when the swap_cgroup's record for this entry is the same
2928 * as the mem_cgroup's id of @from.
2930 * Returns 0 on success, -EINVAL on failure.
2932 * The caller must have charged to @to, IOW, called page_counter_charge() about
2933 * both res and memsw, and called css_get().
2935 static int mem_cgroup_move_swap_account(swp_entry_t entry
,
2936 struct mem_cgroup
*from
, struct mem_cgroup
*to
)
2938 unsigned short old_id
, new_id
;
2940 old_id
= mem_cgroup_id(from
);
2941 new_id
= mem_cgroup_id(to
);
2943 if (swap_cgroup_cmpxchg(entry
, old_id
, new_id
) == old_id
) {
2944 mod_memcg_state(from
, MEMCG_SWAP
, -1);
2945 mod_memcg_state(to
, MEMCG_SWAP
, 1);
2951 static inline int mem_cgroup_move_swap_account(swp_entry_t entry
,
2952 struct mem_cgroup
*from
, struct mem_cgroup
*to
)
2958 static DEFINE_MUTEX(memcg_max_mutex
);
2960 static int mem_cgroup_resize_max(struct mem_cgroup
*memcg
,
2961 unsigned long max
, bool memsw
)
2963 bool enlarge
= false;
2964 bool drained
= false;
2966 bool limits_invariant
;
2967 struct page_counter
*counter
= memsw
? &memcg
->memsw
: &memcg
->memory
;
2970 if (signal_pending(current
)) {
2975 mutex_lock(&memcg_max_mutex
);
2977 * Make sure that the new limit (memsw or memory limit) doesn't
2978 * break our basic invariant rule memory.max <= memsw.max.
2980 limits_invariant
= memsw
? max
>= memcg
->memory
.max
:
2981 max
<= memcg
->memsw
.max
;
2982 if (!limits_invariant
) {
2983 mutex_unlock(&memcg_max_mutex
);
2987 if (max
> counter
->max
)
2989 ret
= page_counter_set_max(counter
, max
);
2990 mutex_unlock(&memcg_max_mutex
);
2996 drain_all_stock(memcg
);
3001 if (!try_to_free_mem_cgroup_pages(memcg
, 1,
3002 GFP_KERNEL
, !memsw
)) {
3008 if (!ret
&& enlarge
)
3009 memcg_oom_recover(memcg
);
3014 unsigned long mem_cgroup_soft_limit_reclaim(pg_data_t
*pgdat
, int order
,
3016 unsigned long *total_scanned
)
3018 unsigned long nr_reclaimed
= 0;
3019 struct mem_cgroup_per_node
*mz
, *next_mz
= NULL
;
3020 unsigned long reclaimed
;
3022 struct mem_cgroup_tree_per_node
*mctz
;
3023 unsigned long excess
;
3024 unsigned long nr_scanned
;
3029 mctz
= soft_limit_tree_node(pgdat
->node_id
);
3032 * Do not even bother to check the largest node if the root
3033 * is empty. Do it lockless to prevent lock bouncing. Races
3034 * are acceptable as soft limit is best effort anyway.
3036 if (!mctz
|| RB_EMPTY_ROOT(&mctz
->rb_root
))
3040 * This loop can run a while, specially if mem_cgroup's continuously
3041 * keep exceeding their soft limit and putting the system under
3048 mz
= mem_cgroup_largest_soft_limit_node(mctz
);
3053 reclaimed
= mem_cgroup_soft_reclaim(mz
->memcg
, pgdat
,
3054 gfp_mask
, &nr_scanned
);
3055 nr_reclaimed
+= reclaimed
;
3056 *total_scanned
+= nr_scanned
;
3057 spin_lock_irq(&mctz
->lock
);
3058 __mem_cgroup_remove_exceeded(mz
, mctz
);
3061 * If we failed to reclaim anything from this memory cgroup
3062 * it is time to move on to the next cgroup
3066 next_mz
= __mem_cgroup_largest_soft_limit_node(mctz
);
3068 excess
= soft_limit_excess(mz
->memcg
);
3070 * One school of thought says that we should not add
3071 * back the node to the tree if reclaim returns 0.
3072 * But our reclaim could return 0, simply because due
3073 * to priority we are exposing a smaller subset of
3074 * memory to reclaim from. Consider this as a longer
3077 /* If excess == 0, no tree ops */
3078 __mem_cgroup_insert_exceeded(mz
, mctz
, excess
);
3079 spin_unlock_irq(&mctz
->lock
);
3080 css_put(&mz
->memcg
->css
);
3083 * Could not reclaim anything and there are no more
3084 * mem cgroups to try or we seem to be looping without
3085 * reclaiming anything.
3087 if (!nr_reclaimed
&&
3089 loop
> MEM_CGROUP_MAX_SOFT_LIMIT_RECLAIM_LOOPS
))
3091 } while (!nr_reclaimed
);
3093 css_put(&next_mz
->memcg
->css
);
3094 return nr_reclaimed
;
3098 * Test whether @memcg has children, dead or alive. Note that this
3099 * function doesn't care whether @memcg has use_hierarchy enabled and
3100 * returns %true if there are child csses according to the cgroup
3101 * hierarchy. Testing use_hierarchy is the caller's responsiblity.
3103 static inline bool memcg_has_children(struct mem_cgroup
*memcg
)
3108 ret
= css_next_child(NULL
, &memcg
->css
);
3114 * Reclaims as many pages from the given memcg as possible.
3116 * Caller is responsible for holding css reference for memcg.
3118 static int mem_cgroup_force_empty(struct mem_cgroup
*memcg
)
3120 int nr_retries
= MEM_CGROUP_RECLAIM_RETRIES
;
3122 /* we call try-to-free pages for make this cgroup empty */
3123 lru_add_drain_all();
3125 drain_all_stock(memcg
);
3127 /* try to free all pages in this cgroup */
3128 while (nr_retries
&& page_counter_read(&memcg
->memory
)) {
3131 if (signal_pending(current
))
3134 progress
= try_to_free_mem_cgroup_pages(memcg
, 1,
3138 /* maybe some writeback is necessary */
3139 congestion_wait(BLK_RW_ASYNC
, HZ
/10);
3147 static ssize_t
mem_cgroup_force_empty_write(struct kernfs_open_file
*of
,
3148 char *buf
, size_t nbytes
,
3151 struct mem_cgroup
*memcg
= mem_cgroup_from_css(of_css(of
));
3153 if (mem_cgroup_is_root(memcg
))
3155 return mem_cgroup_force_empty(memcg
) ?: nbytes
;
3158 static u64
mem_cgroup_hierarchy_read(struct cgroup_subsys_state
*css
,
3161 return mem_cgroup_from_css(css
)->use_hierarchy
;
3164 static int mem_cgroup_hierarchy_write(struct cgroup_subsys_state
*css
,
3165 struct cftype
*cft
, u64 val
)
3168 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
3169 struct mem_cgroup
*parent_memcg
= mem_cgroup_from_css(memcg
->css
.parent
);
3171 if (memcg
->use_hierarchy
== val
)
3175 * If parent's use_hierarchy is set, we can't make any modifications
3176 * in the child subtrees. If it is unset, then the change can
3177 * occur, provided the current cgroup has no children.
3179 * For the root cgroup, parent_mem is NULL, we allow value to be
3180 * set if there are no children.
3182 if ((!parent_memcg
|| !parent_memcg
->use_hierarchy
) &&
3183 (val
== 1 || val
== 0)) {
3184 if (!memcg_has_children(memcg
))
3185 memcg
->use_hierarchy
= val
;
3194 static unsigned long mem_cgroup_usage(struct mem_cgroup
*memcg
, bool swap
)
3198 if (mem_cgroup_is_root(memcg
)) {
3199 val
= memcg_page_state(memcg
, MEMCG_CACHE
) +
3200 memcg_page_state(memcg
, MEMCG_RSS
);
3202 val
+= memcg_page_state(memcg
, MEMCG_SWAP
);
3205 val
= page_counter_read(&memcg
->memory
);
3207 val
= page_counter_read(&memcg
->memsw
);
3220 static u64
mem_cgroup_read_u64(struct cgroup_subsys_state
*css
,
3223 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
3224 struct page_counter
*counter
;
3226 switch (MEMFILE_TYPE(cft
->private)) {
3228 counter
= &memcg
->memory
;
3231 counter
= &memcg
->memsw
;
3234 counter
= &memcg
->kmem
;
3237 counter
= &memcg
->tcpmem
;
3243 switch (MEMFILE_ATTR(cft
->private)) {
3245 if (counter
== &memcg
->memory
)
3246 return (u64
)mem_cgroup_usage(memcg
, false) * PAGE_SIZE
;
3247 if (counter
== &memcg
->memsw
)
3248 return (u64
)mem_cgroup_usage(memcg
, true) * PAGE_SIZE
;
3249 return (u64
)page_counter_read(counter
) * PAGE_SIZE
;
3251 return (u64
)counter
->max
* PAGE_SIZE
;
3253 return (u64
)counter
->watermark
* PAGE_SIZE
;
3255 return counter
->failcnt
;
3256 case RES_SOFT_LIMIT
:
3257 return (u64
)memcg
->soft_limit
* PAGE_SIZE
;
3263 #ifdef CONFIG_MEMCG_KMEM
3264 static int memcg_online_kmem(struct mem_cgroup
*memcg
)
3268 if (cgroup_memory_nokmem
)
3271 BUG_ON(memcg
->kmemcg_id
>= 0);
3272 BUG_ON(memcg
->kmem_state
);
3274 memcg_id
= memcg_alloc_cache_id();
3278 static_branch_inc(&memcg_kmem_enabled_key
);
3280 * A memory cgroup is considered kmem-online as soon as it gets
3281 * kmemcg_id. Setting the id after enabling static branching will
3282 * guarantee no one starts accounting before all call sites are
3285 memcg
->kmemcg_id
= memcg_id
;
3286 memcg
->kmem_state
= KMEM_ONLINE
;
3287 INIT_LIST_HEAD(&memcg
->kmem_caches
);
3292 static void memcg_offline_kmem(struct mem_cgroup
*memcg
)
3294 struct cgroup_subsys_state
*css
;
3295 struct mem_cgroup
*parent
, *child
;
3298 if (memcg
->kmem_state
!= KMEM_ONLINE
)
3301 * Clear the online state before clearing memcg_caches array
3302 * entries. The slab_mutex in memcg_deactivate_kmem_caches()
3303 * guarantees that no cache will be created for this cgroup
3304 * after we are done (see memcg_create_kmem_cache()).
3306 memcg
->kmem_state
= KMEM_ALLOCATED
;
3308 parent
= parent_mem_cgroup(memcg
);
3310 parent
= root_mem_cgroup
;
3312 memcg_deactivate_kmem_caches(memcg
, parent
);
3314 kmemcg_id
= memcg
->kmemcg_id
;
3315 BUG_ON(kmemcg_id
< 0);
3318 * Change kmemcg_id of this cgroup and all its descendants to the
3319 * parent's id, and then move all entries from this cgroup's list_lrus
3320 * to ones of the parent. After we have finished, all list_lrus
3321 * corresponding to this cgroup are guaranteed to remain empty. The
3322 * ordering is imposed by list_lru_node->lock taken by
3323 * memcg_drain_all_list_lrus().
3325 rcu_read_lock(); /* can be called from css_free w/o cgroup_mutex */
3326 css_for_each_descendant_pre(css
, &memcg
->css
) {
3327 child
= mem_cgroup_from_css(css
);
3328 BUG_ON(child
->kmemcg_id
!= kmemcg_id
);
3329 child
->kmemcg_id
= parent
->kmemcg_id
;
3330 if (!memcg
->use_hierarchy
)
3335 memcg_drain_all_list_lrus(kmemcg_id
, parent
);
3337 memcg_free_cache_id(kmemcg_id
);
3340 static void memcg_free_kmem(struct mem_cgroup
*memcg
)
3342 /* css_alloc() failed, offlining didn't happen */
3343 if (unlikely(memcg
->kmem_state
== KMEM_ONLINE
))
3344 memcg_offline_kmem(memcg
);
3346 if (memcg
->kmem_state
== KMEM_ALLOCATED
) {
3347 WARN_ON(!list_empty(&memcg
->kmem_caches
));
3348 static_branch_dec(&memcg_kmem_enabled_key
);
3352 static int memcg_online_kmem(struct mem_cgroup
*memcg
)
3356 static void memcg_offline_kmem(struct mem_cgroup
*memcg
)
3359 static void memcg_free_kmem(struct mem_cgroup
*memcg
)
3362 #endif /* CONFIG_MEMCG_KMEM */
3364 static int memcg_update_kmem_max(struct mem_cgroup
*memcg
,
3369 mutex_lock(&memcg_max_mutex
);
3370 ret
= page_counter_set_max(&memcg
->kmem
, max
);
3371 mutex_unlock(&memcg_max_mutex
);
3375 static int memcg_update_tcp_max(struct mem_cgroup
*memcg
, unsigned long max
)
3379 mutex_lock(&memcg_max_mutex
);
3381 ret
= page_counter_set_max(&memcg
->tcpmem
, max
);
3385 if (!memcg
->tcpmem_active
) {
3387 * The active flag needs to be written after the static_key
3388 * update. This is what guarantees that the socket activation
3389 * function is the last one to run. See mem_cgroup_sk_alloc()
3390 * for details, and note that we don't mark any socket as
3391 * belonging to this memcg until that flag is up.
3393 * We need to do this, because static_keys will span multiple
3394 * sites, but we can't control their order. If we mark a socket
3395 * as accounted, but the accounting functions are not patched in
3396 * yet, we'll lose accounting.
3398 * We never race with the readers in mem_cgroup_sk_alloc(),
3399 * because when this value change, the code to process it is not
3402 static_branch_inc(&memcg_sockets_enabled_key
);
3403 memcg
->tcpmem_active
= true;
3406 mutex_unlock(&memcg_max_mutex
);
3411 * The user of this function is...
3414 static ssize_t
mem_cgroup_write(struct kernfs_open_file
*of
,
3415 char *buf
, size_t nbytes
, loff_t off
)
3417 struct mem_cgroup
*memcg
= mem_cgroup_from_css(of_css(of
));
3418 unsigned long nr_pages
;
3421 buf
= strstrip(buf
);
3422 ret
= page_counter_memparse(buf
, "-1", &nr_pages
);
3426 switch (MEMFILE_ATTR(of_cft(of
)->private)) {
3428 if (mem_cgroup_is_root(memcg
)) { /* Can't set limit on root */
3432 switch (MEMFILE_TYPE(of_cft(of
)->private)) {
3434 ret
= mem_cgroup_resize_max(memcg
, nr_pages
, false);
3437 ret
= mem_cgroup_resize_max(memcg
, nr_pages
, true);
3440 ret
= memcg_update_kmem_max(memcg
, nr_pages
);
3443 ret
= memcg_update_tcp_max(memcg
, nr_pages
);
3447 case RES_SOFT_LIMIT
:
3448 memcg
->soft_limit
= nr_pages
;
3452 return ret
?: nbytes
;
3455 static ssize_t
mem_cgroup_reset(struct kernfs_open_file
*of
, char *buf
,
3456 size_t nbytes
, loff_t off
)
3458 struct mem_cgroup
*memcg
= mem_cgroup_from_css(of_css(of
));
3459 struct page_counter
*counter
;
3461 switch (MEMFILE_TYPE(of_cft(of
)->private)) {
3463 counter
= &memcg
->memory
;
3466 counter
= &memcg
->memsw
;
3469 counter
= &memcg
->kmem
;
3472 counter
= &memcg
->tcpmem
;
3478 switch (MEMFILE_ATTR(of_cft(of
)->private)) {
3480 page_counter_reset_watermark(counter
);
3483 counter
->failcnt
= 0;
3492 static u64
mem_cgroup_move_charge_read(struct cgroup_subsys_state
*css
,
3495 return mem_cgroup_from_css(css
)->move_charge_at_immigrate
;
3499 static int mem_cgroup_move_charge_write(struct cgroup_subsys_state
*css
,
3500 struct cftype
*cft
, u64 val
)
3502 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
3504 if (val
& ~MOVE_MASK
)
3508 * No kind of locking is needed in here, because ->can_attach() will
3509 * check this value once in the beginning of the process, and then carry
3510 * on with stale data. This means that changes to this value will only
3511 * affect task migrations starting after the change.
3513 memcg
->move_charge_at_immigrate
= val
;
3517 static int mem_cgroup_move_charge_write(struct cgroup_subsys_state
*css
,
3518 struct cftype
*cft
, u64 val
)
3526 #define LRU_ALL_FILE (BIT(LRU_INACTIVE_FILE) | BIT(LRU_ACTIVE_FILE))
3527 #define LRU_ALL_ANON (BIT(LRU_INACTIVE_ANON) | BIT(LRU_ACTIVE_ANON))
3528 #define LRU_ALL ((1 << NR_LRU_LISTS) - 1)
3530 static unsigned long mem_cgroup_node_nr_lru_pages(struct mem_cgroup
*memcg
,
3531 int nid
, unsigned int lru_mask
)
3533 struct lruvec
*lruvec
= mem_cgroup_lruvec(NODE_DATA(nid
), memcg
);
3534 unsigned long nr
= 0;
3537 VM_BUG_ON((unsigned)nid
>= nr_node_ids
);
3540 if (!(BIT(lru
) & lru_mask
))
3542 nr
+= lruvec_page_state_local(lruvec
, NR_LRU_BASE
+ lru
);
3547 static unsigned long mem_cgroup_nr_lru_pages(struct mem_cgroup
*memcg
,
3548 unsigned int lru_mask
)
3550 unsigned long nr
= 0;
3554 if (!(BIT(lru
) & lru_mask
))
3556 nr
+= memcg_page_state_local(memcg
, NR_LRU_BASE
+ lru
);
3561 static int memcg_numa_stat_show(struct seq_file
*m
, void *v
)
3565 unsigned int lru_mask
;
3568 static const struct numa_stat stats
[] = {
3569 { "total", LRU_ALL
},
3570 { "file", LRU_ALL_FILE
},
3571 { "anon", LRU_ALL_ANON
},
3572 { "unevictable", BIT(LRU_UNEVICTABLE
) },
3574 const struct numa_stat
*stat
;
3577 struct mem_cgroup
*memcg
= mem_cgroup_from_seq(m
);
3579 for (stat
= stats
; stat
< stats
+ ARRAY_SIZE(stats
); stat
++) {
3580 nr
= mem_cgroup_nr_lru_pages(memcg
, stat
->lru_mask
);
3581 seq_printf(m
, "%s=%lu", stat
->name
, nr
);
3582 for_each_node_state(nid
, N_MEMORY
) {
3583 nr
= mem_cgroup_node_nr_lru_pages(memcg
, nid
,
3585 seq_printf(m
, " N%d=%lu", nid
, nr
);
3590 for (stat
= stats
; stat
< stats
+ ARRAY_SIZE(stats
); stat
++) {
3591 struct mem_cgroup
*iter
;
3594 for_each_mem_cgroup_tree(iter
, memcg
)
3595 nr
+= mem_cgroup_nr_lru_pages(iter
, stat
->lru_mask
);
3596 seq_printf(m
, "hierarchical_%s=%lu", stat
->name
, nr
);
3597 for_each_node_state(nid
, N_MEMORY
) {
3599 for_each_mem_cgroup_tree(iter
, memcg
)
3600 nr
+= mem_cgroup_node_nr_lru_pages(
3601 iter
, nid
, stat
->lru_mask
);
3602 seq_printf(m
, " N%d=%lu", nid
, nr
);
3609 #endif /* CONFIG_NUMA */
3611 static const unsigned int memcg1_stats
[] = {
3622 static const char *const memcg1_stat_names
[] = {
3633 /* Universal VM events cgroup1 shows, original sort order */
3634 static const unsigned int memcg1_events
[] = {
3641 static const char *const memcg1_event_names
[] = {
3648 static int memcg_stat_show(struct seq_file
*m
, void *v
)
3650 struct mem_cgroup
*memcg
= mem_cgroup_from_seq(m
);
3651 unsigned long memory
, memsw
;
3652 struct mem_cgroup
*mi
;
3655 BUILD_BUG_ON(ARRAY_SIZE(memcg1_stat_names
) != ARRAY_SIZE(memcg1_stats
));
3656 BUILD_BUG_ON(ARRAY_SIZE(mem_cgroup_lru_names
) != NR_LRU_LISTS
);
3658 for (i
= 0; i
< ARRAY_SIZE(memcg1_stats
); i
++) {
3659 if (memcg1_stats
[i
] == MEMCG_SWAP
&& !do_memsw_account())
3661 seq_printf(m
, "%s %lu\n", memcg1_stat_names
[i
],
3662 memcg_page_state_local(memcg
, memcg1_stats
[i
]) *
3666 for (i
= 0; i
< ARRAY_SIZE(memcg1_events
); i
++)
3667 seq_printf(m
, "%s %lu\n", memcg1_event_names
[i
],
3668 memcg_events_local(memcg
, memcg1_events
[i
]));
3670 for (i
= 0; i
< NR_LRU_LISTS
; i
++)
3671 seq_printf(m
, "%s %lu\n", mem_cgroup_lru_names
[i
],
3672 memcg_page_state_local(memcg
, NR_LRU_BASE
+ i
) *
3675 /* Hierarchical information */
3676 memory
= memsw
= PAGE_COUNTER_MAX
;
3677 for (mi
= memcg
; mi
; mi
= parent_mem_cgroup(mi
)) {
3678 memory
= min(memory
, mi
->memory
.max
);
3679 memsw
= min(memsw
, mi
->memsw
.max
);
3681 seq_printf(m
, "hierarchical_memory_limit %llu\n",
3682 (u64
)memory
* PAGE_SIZE
);
3683 if (do_memsw_account())
3684 seq_printf(m
, "hierarchical_memsw_limit %llu\n",
3685 (u64
)memsw
* PAGE_SIZE
);
3687 for (i
= 0; i
< ARRAY_SIZE(memcg1_stats
); i
++) {
3688 if (memcg1_stats
[i
] == MEMCG_SWAP
&& !do_memsw_account())
3690 seq_printf(m
, "total_%s %llu\n", memcg1_stat_names
[i
],
3691 (u64
)memcg_page_state(memcg
, memcg1_stats
[i
]) *
3695 for (i
= 0; i
< ARRAY_SIZE(memcg1_events
); i
++)
3696 seq_printf(m
, "total_%s %llu\n", memcg1_event_names
[i
],
3697 (u64
)memcg_events(memcg
, memcg1_events
[i
]));
3699 for (i
= 0; i
< NR_LRU_LISTS
; i
++)
3700 seq_printf(m
, "total_%s %llu\n", mem_cgroup_lru_names
[i
],
3701 (u64
)memcg_page_state(memcg
, NR_LRU_BASE
+ i
) *
3704 #ifdef CONFIG_DEBUG_VM
3707 struct mem_cgroup_per_node
*mz
;
3708 struct zone_reclaim_stat
*rstat
;
3709 unsigned long recent_rotated
[2] = {0, 0};
3710 unsigned long recent_scanned
[2] = {0, 0};
3712 for_each_online_pgdat(pgdat
) {
3713 mz
= mem_cgroup_nodeinfo(memcg
, pgdat
->node_id
);
3714 rstat
= &mz
->lruvec
.reclaim_stat
;
3716 recent_rotated
[0] += rstat
->recent_rotated
[0];
3717 recent_rotated
[1] += rstat
->recent_rotated
[1];
3718 recent_scanned
[0] += rstat
->recent_scanned
[0];
3719 recent_scanned
[1] += rstat
->recent_scanned
[1];
3721 seq_printf(m
, "recent_rotated_anon %lu\n", recent_rotated
[0]);
3722 seq_printf(m
, "recent_rotated_file %lu\n", recent_rotated
[1]);
3723 seq_printf(m
, "recent_scanned_anon %lu\n", recent_scanned
[0]);
3724 seq_printf(m
, "recent_scanned_file %lu\n", recent_scanned
[1]);
3731 static u64
mem_cgroup_swappiness_read(struct cgroup_subsys_state
*css
,
3734 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
3736 return mem_cgroup_swappiness(memcg
);
3739 static int mem_cgroup_swappiness_write(struct cgroup_subsys_state
*css
,
3740 struct cftype
*cft
, u64 val
)
3742 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
3748 memcg
->swappiness
= val
;
3750 vm_swappiness
= val
;
3755 static void __mem_cgroup_threshold(struct mem_cgroup
*memcg
, bool swap
)
3757 struct mem_cgroup_threshold_ary
*t
;
3758 unsigned long usage
;
3763 t
= rcu_dereference(memcg
->thresholds
.primary
);
3765 t
= rcu_dereference(memcg
->memsw_thresholds
.primary
);
3770 usage
= mem_cgroup_usage(memcg
, swap
);
3773 * current_threshold points to threshold just below or equal to usage.
3774 * If it's not true, a threshold was crossed after last
3775 * call of __mem_cgroup_threshold().
3777 i
= t
->current_threshold
;
3780 * Iterate backward over array of thresholds starting from
3781 * current_threshold and check if a threshold is crossed.
3782 * If none of thresholds below usage is crossed, we read
3783 * only one element of the array here.
3785 for (; i
>= 0 && unlikely(t
->entries
[i
].threshold
> usage
); i
--)
3786 eventfd_signal(t
->entries
[i
].eventfd
, 1);
3788 /* i = current_threshold + 1 */
3792 * Iterate forward over array of thresholds starting from
3793 * current_threshold+1 and check if a threshold is crossed.
3794 * If none of thresholds above usage is crossed, we read
3795 * only one element of the array here.
3797 for (; i
< t
->size
&& unlikely(t
->entries
[i
].threshold
<= usage
); i
++)
3798 eventfd_signal(t
->entries
[i
].eventfd
, 1);
3800 /* Update current_threshold */
3801 t
->current_threshold
= i
- 1;
3806 static void mem_cgroup_threshold(struct mem_cgroup
*memcg
)
3809 __mem_cgroup_threshold(memcg
, false);
3810 if (do_memsw_account())
3811 __mem_cgroup_threshold(memcg
, true);
3813 memcg
= parent_mem_cgroup(memcg
);
3817 static int compare_thresholds(const void *a
, const void *b
)
3819 const struct mem_cgroup_threshold
*_a
= a
;
3820 const struct mem_cgroup_threshold
*_b
= b
;
3822 if (_a
->threshold
> _b
->threshold
)
3825 if (_a
->threshold
< _b
->threshold
)
3831 static int mem_cgroup_oom_notify_cb(struct mem_cgroup
*memcg
)
3833 struct mem_cgroup_eventfd_list
*ev
;
3835 spin_lock(&memcg_oom_lock
);
3837 list_for_each_entry(ev
, &memcg
->oom_notify
, list
)
3838 eventfd_signal(ev
->eventfd
, 1);
3840 spin_unlock(&memcg_oom_lock
);
3844 static void mem_cgroup_oom_notify(struct mem_cgroup
*memcg
)
3846 struct mem_cgroup
*iter
;
3848 for_each_mem_cgroup_tree(iter
, memcg
)
3849 mem_cgroup_oom_notify_cb(iter
);
3852 static int __mem_cgroup_usage_register_event(struct mem_cgroup
*memcg
,
3853 struct eventfd_ctx
*eventfd
, const char *args
, enum res_type type
)
3855 struct mem_cgroup_thresholds
*thresholds
;
3856 struct mem_cgroup_threshold_ary
*new;
3857 unsigned long threshold
;
3858 unsigned long usage
;
3861 ret
= page_counter_memparse(args
, "-1", &threshold
);
3865 mutex_lock(&memcg
->thresholds_lock
);
3868 thresholds
= &memcg
->thresholds
;
3869 usage
= mem_cgroup_usage(memcg
, false);
3870 } else if (type
== _MEMSWAP
) {
3871 thresholds
= &memcg
->memsw_thresholds
;
3872 usage
= mem_cgroup_usage(memcg
, true);
3876 /* Check if a threshold crossed before adding a new one */
3877 if (thresholds
->primary
)
3878 __mem_cgroup_threshold(memcg
, type
== _MEMSWAP
);
3880 size
= thresholds
->primary
? thresholds
->primary
->size
+ 1 : 1;
3882 /* Allocate memory for new array of thresholds */
3883 new = kmalloc(struct_size(new, entries
, size
), GFP_KERNEL
);
3890 /* Copy thresholds (if any) to new array */
3891 if (thresholds
->primary
) {
3892 memcpy(new->entries
, thresholds
->primary
->entries
, (size
- 1) *
3893 sizeof(struct mem_cgroup_threshold
));
3896 /* Add new threshold */
3897 new->entries
[size
- 1].eventfd
= eventfd
;
3898 new->entries
[size
- 1].threshold
= threshold
;
3900 /* Sort thresholds. Registering of new threshold isn't time-critical */
3901 sort(new->entries
, size
, sizeof(struct mem_cgroup_threshold
),
3902 compare_thresholds
, NULL
);
3904 /* Find current threshold */
3905 new->current_threshold
= -1;
3906 for (i
= 0; i
< size
; i
++) {
3907 if (new->entries
[i
].threshold
<= usage
) {
3909 * new->current_threshold will not be used until
3910 * rcu_assign_pointer(), so it's safe to increment
3913 ++new->current_threshold
;
3918 /* Free old spare buffer and save old primary buffer as spare */
3919 kfree(thresholds
->spare
);
3920 thresholds
->spare
= thresholds
->primary
;
3922 rcu_assign_pointer(thresholds
->primary
, new);
3924 /* To be sure that nobody uses thresholds */
3928 mutex_unlock(&memcg
->thresholds_lock
);
3933 static int mem_cgroup_usage_register_event(struct mem_cgroup
*memcg
,
3934 struct eventfd_ctx
*eventfd
, const char *args
)
3936 return __mem_cgroup_usage_register_event(memcg
, eventfd
, args
, _MEM
);
3939 static int memsw_cgroup_usage_register_event(struct mem_cgroup
*memcg
,
3940 struct eventfd_ctx
*eventfd
, const char *args
)
3942 return __mem_cgroup_usage_register_event(memcg
, eventfd
, args
, _MEMSWAP
);
3945 static void __mem_cgroup_usage_unregister_event(struct mem_cgroup
*memcg
,
3946 struct eventfd_ctx
*eventfd
, enum res_type type
)
3948 struct mem_cgroup_thresholds
*thresholds
;
3949 struct mem_cgroup_threshold_ary
*new;
3950 unsigned long usage
;
3953 mutex_lock(&memcg
->thresholds_lock
);
3956 thresholds
= &memcg
->thresholds
;
3957 usage
= mem_cgroup_usage(memcg
, false);
3958 } else if (type
== _MEMSWAP
) {
3959 thresholds
= &memcg
->memsw_thresholds
;
3960 usage
= mem_cgroup_usage(memcg
, true);
3964 if (!thresholds
->primary
)
3967 /* Check if a threshold crossed before removing */
3968 __mem_cgroup_threshold(memcg
, type
== _MEMSWAP
);
3970 /* Calculate new number of threshold */
3972 for (i
= 0; i
< thresholds
->primary
->size
; i
++) {
3973 if (thresholds
->primary
->entries
[i
].eventfd
!= eventfd
)
3977 new = thresholds
->spare
;
3979 /* Set thresholds array to NULL if we don't have thresholds */
3988 /* Copy thresholds and find current threshold */
3989 new->current_threshold
= -1;
3990 for (i
= 0, j
= 0; i
< thresholds
->primary
->size
; i
++) {
3991 if (thresholds
->primary
->entries
[i
].eventfd
== eventfd
)
3994 new->entries
[j
] = thresholds
->primary
->entries
[i
];
3995 if (new->entries
[j
].threshold
<= usage
) {
3997 * new->current_threshold will not be used
3998 * until rcu_assign_pointer(), so it's safe to increment
4001 ++new->current_threshold
;
4007 /* Swap primary and spare array */
4008 thresholds
->spare
= thresholds
->primary
;
4010 rcu_assign_pointer(thresholds
->primary
, new);
4012 /* To be sure that nobody uses thresholds */
4015 /* If all events are unregistered, free the spare array */
4017 kfree(thresholds
->spare
);
4018 thresholds
->spare
= NULL
;
4021 mutex_unlock(&memcg
->thresholds_lock
);
4024 static void mem_cgroup_usage_unregister_event(struct mem_cgroup
*memcg
,
4025 struct eventfd_ctx
*eventfd
)
4027 return __mem_cgroup_usage_unregister_event(memcg
, eventfd
, _MEM
);
4030 static void memsw_cgroup_usage_unregister_event(struct mem_cgroup
*memcg
,
4031 struct eventfd_ctx
*eventfd
)
4033 return __mem_cgroup_usage_unregister_event(memcg
, eventfd
, _MEMSWAP
);
4036 static int mem_cgroup_oom_register_event(struct mem_cgroup
*memcg
,
4037 struct eventfd_ctx
*eventfd
, const char *args
)
4039 struct mem_cgroup_eventfd_list
*event
;
4041 event
= kmalloc(sizeof(*event
), GFP_KERNEL
);
4045 spin_lock(&memcg_oom_lock
);
4047 event
->eventfd
= eventfd
;
4048 list_add(&event
->list
, &memcg
->oom_notify
);
4050 /* already in OOM ? */
4051 if (memcg
->under_oom
)
4052 eventfd_signal(eventfd
, 1);
4053 spin_unlock(&memcg_oom_lock
);
4058 static void mem_cgroup_oom_unregister_event(struct mem_cgroup
*memcg
,
4059 struct eventfd_ctx
*eventfd
)
4061 struct mem_cgroup_eventfd_list
*ev
, *tmp
;
4063 spin_lock(&memcg_oom_lock
);
4065 list_for_each_entry_safe(ev
, tmp
, &memcg
->oom_notify
, list
) {
4066 if (ev
->eventfd
== eventfd
) {
4067 list_del(&ev
->list
);
4072 spin_unlock(&memcg_oom_lock
);
4075 static int mem_cgroup_oom_control_read(struct seq_file
*sf
, void *v
)
4077 struct mem_cgroup
*memcg
= mem_cgroup_from_seq(sf
);
4079 seq_printf(sf
, "oom_kill_disable %d\n", memcg
->oom_kill_disable
);
4080 seq_printf(sf
, "under_oom %d\n", (bool)memcg
->under_oom
);
4081 seq_printf(sf
, "oom_kill %lu\n",
4082 atomic_long_read(&memcg
->memory_events
[MEMCG_OOM_KILL
]));
4086 static int mem_cgroup_oom_control_write(struct cgroup_subsys_state
*css
,
4087 struct cftype
*cft
, u64 val
)
4089 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
4091 /* cannot set to root cgroup and only 0 and 1 are allowed */
4092 if (!css
->parent
|| !((val
== 0) || (val
== 1)))
4095 memcg
->oom_kill_disable
= val
;
4097 memcg_oom_recover(memcg
);
4102 #ifdef CONFIG_CGROUP_WRITEBACK
4104 static int memcg_wb_domain_init(struct mem_cgroup
*memcg
, gfp_t gfp
)
4106 return wb_domain_init(&memcg
->cgwb_domain
, gfp
);
4109 static void memcg_wb_domain_exit(struct mem_cgroup
*memcg
)
4111 wb_domain_exit(&memcg
->cgwb_domain
);
4114 static void memcg_wb_domain_size_changed(struct mem_cgroup
*memcg
)
4116 wb_domain_size_changed(&memcg
->cgwb_domain
);
4119 struct wb_domain
*mem_cgroup_wb_domain(struct bdi_writeback
*wb
)
4121 struct mem_cgroup
*memcg
= mem_cgroup_from_css(wb
->memcg_css
);
4123 if (!memcg
->css
.parent
)
4126 return &memcg
->cgwb_domain
;
4130 * idx can be of type enum memcg_stat_item or node_stat_item.
4131 * Keep in sync with memcg_exact_page().
4133 static unsigned long memcg_exact_page_state(struct mem_cgroup
*memcg
, int idx
)
4135 long x
= atomic_long_read(&memcg
->vmstats
[idx
]);
4138 for_each_online_cpu(cpu
)
4139 x
+= per_cpu_ptr(memcg
->vmstats_percpu
, cpu
)->stat
[idx
];
4146 * mem_cgroup_wb_stats - retrieve writeback related stats from its memcg
4147 * @wb: bdi_writeback in question
4148 * @pfilepages: out parameter for number of file pages
4149 * @pheadroom: out parameter for number of allocatable pages according to memcg
4150 * @pdirty: out parameter for number of dirty pages
4151 * @pwriteback: out parameter for number of pages under writeback
4153 * Determine the numbers of file, headroom, dirty, and writeback pages in
4154 * @wb's memcg. File, dirty and writeback are self-explanatory. Headroom
4155 * is a bit more involved.
4157 * A memcg's headroom is "min(max, high) - used". In the hierarchy, the
4158 * headroom is calculated as the lowest headroom of itself and the
4159 * ancestors. Note that this doesn't consider the actual amount of
4160 * available memory in the system. The caller should further cap
4161 * *@pheadroom accordingly.
4163 void mem_cgroup_wb_stats(struct bdi_writeback
*wb
, unsigned long *pfilepages
,
4164 unsigned long *pheadroom
, unsigned long *pdirty
,
4165 unsigned long *pwriteback
)
4167 struct mem_cgroup
*memcg
= mem_cgroup_from_css(wb
->memcg_css
);
4168 struct mem_cgroup
*parent
;
4170 *pdirty
= memcg_exact_page_state(memcg
, NR_FILE_DIRTY
);
4172 /* this should eventually include NR_UNSTABLE_NFS */
4173 *pwriteback
= memcg_exact_page_state(memcg
, NR_WRITEBACK
);
4174 *pfilepages
= memcg_exact_page_state(memcg
, NR_INACTIVE_FILE
) +
4175 memcg_exact_page_state(memcg
, NR_ACTIVE_FILE
);
4176 *pheadroom
= PAGE_COUNTER_MAX
;
4178 while ((parent
= parent_mem_cgroup(memcg
))) {
4179 unsigned long ceiling
= min(memcg
->memory
.max
, memcg
->high
);
4180 unsigned long used
= page_counter_read(&memcg
->memory
);
4182 *pheadroom
= min(*pheadroom
, ceiling
- min(ceiling
, used
));
4187 #else /* CONFIG_CGROUP_WRITEBACK */
4189 static int memcg_wb_domain_init(struct mem_cgroup
*memcg
, gfp_t gfp
)
4194 static void memcg_wb_domain_exit(struct mem_cgroup
*memcg
)
4198 static void memcg_wb_domain_size_changed(struct mem_cgroup
*memcg
)
4202 #endif /* CONFIG_CGROUP_WRITEBACK */
4205 * DO NOT USE IN NEW FILES.
4207 * "cgroup.event_control" implementation.
4209 * This is way over-engineered. It tries to support fully configurable
4210 * events for each user. Such level of flexibility is completely
4211 * unnecessary especially in the light of the planned unified hierarchy.
4213 * Please deprecate this and replace with something simpler if at all
4218 * Unregister event and free resources.
4220 * Gets called from workqueue.
4222 static void memcg_event_remove(struct work_struct
*work
)
4224 struct mem_cgroup_event
*event
=
4225 container_of(work
, struct mem_cgroup_event
, remove
);
4226 struct mem_cgroup
*memcg
= event
->memcg
;
4228 remove_wait_queue(event
->wqh
, &event
->wait
);
4230 event
->unregister_event(memcg
, event
->eventfd
);
4232 /* Notify userspace the event is going away. */
4233 eventfd_signal(event
->eventfd
, 1);
4235 eventfd_ctx_put(event
->eventfd
);
4237 css_put(&memcg
->css
);
4241 * Gets called on EPOLLHUP on eventfd when user closes it.
4243 * Called with wqh->lock held and interrupts disabled.
4245 static int memcg_event_wake(wait_queue_entry_t
*wait
, unsigned mode
,
4246 int sync
, void *key
)
4248 struct mem_cgroup_event
*event
=
4249 container_of(wait
, struct mem_cgroup_event
, wait
);
4250 struct mem_cgroup
*memcg
= event
->memcg
;
4251 __poll_t flags
= key_to_poll(key
);
4253 if (flags
& EPOLLHUP
) {
4255 * If the event has been detached at cgroup removal, we
4256 * can simply return knowing the other side will cleanup
4259 * We can't race against event freeing since the other
4260 * side will require wqh->lock via remove_wait_queue(),
4263 spin_lock(&memcg
->event_list_lock
);
4264 if (!list_empty(&event
->list
)) {
4265 list_del_init(&event
->list
);
4267 * We are in atomic context, but cgroup_event_remove()
4268 * may sleep, so we have to call it in workqueue.
4270 schedule_work(&event
->remove
);
4272 spin_unlock(&memcg
->event_list_lock
);
4278 static void memcg_event_ptable_queue_proc(struct file
*file
,
4279 wait_queue_head_t
*wqh
, poll_table
*pt
)
4281 struct mem_cgroup_event
*event
=
4282 container_of(pt
, struct mem_cgroup_event
, pt
);
4285 add_wait_queue(wqh
, &event
->wait
);
4289 * DO NOT USE IN NEW FILES.
4291 * Parse input and register new cgroup event handler.
4293 * Input must be in format '<event_fd> <control_fd> <args>'.
4294 * Interpretation of args is defined by control file implementation.
4296 static ssize_t
memcg_write_event_control(struct kernfs_open_file
*of
,
4297 char *buf
, size_t nbytes
, loff_t off
)
4299 struct cgroup_subsys_state
*css
= of_css(of
);
4300 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
4301 struct mem_cgroup_event
*event
;
4302 struct cgroup_subsys_state
*cfile_css
;
4303 unsigned int efd
, cfd
;
4310 buf
= strstrip(buf
);
4312 efd
= simple_strtoul(buf
, &endp
, 10);
4317 cfd
= simple_strtoul(buf
, &endp
, 10);
4318 if ((*endp
!= ' ') && (*endp
!= '\0'))
4322 event
= kzalloc(sizeof(*event
), GFP_KERNEL
);
4326 event
->memcg
= memcg
;
4327 INIT_LIST_HEAD(&event
->list
);
4328 init_poll_funcptr(&event
->pt
, memcg_event_ptable_queue_proc
);
4329 init_waitqueue_func_entry(&event
->wait
, memcg_event_wake
);
4330 INIT_WORK(&event
->remove
, memcg_event_remove
);
4338 event
->eventfd
= eventfd_ctx_fileget(efile
.file
);
4339 if (IS_ERR(event
->eventfd
)) {
4340 ret
= PTR_ERR(event
->eventfd
);
4347 goto out_put_eventfd
;
4350 /* the process need read permission on control file */
4351 /* AV: shouldn't we check that it's been opened for read instead? */
4352 ret
= inode_permission(file_inode(cfile
.file
), MAY_READ
);
4357 * Determine the event callbacks and set them in @event. This used
4358 * to be done via struct cftype but cgroup core no longer knows
4359 * about these events. The following is crude but the whole thing
4360 * is for compatibility anyway.
4362 * DO NOT ADD NEW FILES.
4364 name
= cfile
.file
->f_path
.dentry
->d_name
.name
;
4366 if (!strcmp(name
, "memory.usage_in_bytes")) {
4367 event
->register_event
= mem_cgroup_usage_register_event
;
4368 event
->unregister_event
= mem_cgroup_usage_unregister_event
;
4369 } else if (!strcmp(name
, "memory.oom_control")) {
4370 event
->register_event
= mem_cgroup_oom_register_event
;
4371 event
->unregister_event
= mem_cgroup_oom_unregister_event
;
4372 } else if (!strcmp(name
, "memory.pressure_level")) {
4373 event
->register_event
= vmpressure_register_event
;
4374 event
->unregister_event
= vmpressure_unregister_event
;
4375 } else if (!strcmp(name
, "memory.memsw.usage_in_bytes")) {
4376 event
->register_event
= memsw_cgroup_usage_register_event
;
4377 event
->unregister_event
= memsw_cgroup_usage_unregister_event
;
4384 * Verify @cfile should belong to @css. Also, remaining events are
4385 * automatically removed on cgroup destruction but the removal is
4386 * asynchronous, so take an extra ref on @css.
4388 cfile_css
= css_tryget_online_from_dir(cfile
.file
->f_path
.dentry
->d_parent
,
4389 &memory_cgrp_subsys
);
4391 if (IS_ERR(cfile_css
))
4393 if (cfile_css
!= css
) {
4398 ret
= event
->register_event(memcg
, event
->eventfd
, buf
);
4402 vfs_poll(efile
.file
, &event
->pt
);
4404 spin_lock(&memcg
->event_list_lock
);
4405 list_add(&event
->list
, &memcg
->event_list
);
4406 spin_unlock(&memcg
->event_list_lock
);
4418 eventfd_ctx_put(event
->eventfd
);
4427 static struct cftype mem_cgroup_legacy_files
[] = {
4429 .name
= "usage_in_bytes",
4430 .private = MEMFILE_PRIVATE(_MEM
, RES_USAGE
),
4431 .read_u64
= mem_cgroup_read_u64
,
4434 .name
= "max_usage_in_bytes",
4435 .private = MEMFILE_PRIVATE(_MEM
, RES_MAX_USAGE
),
4436 .write
= mem_cgroup_reset
,
4437 .read_u64
= mem_cgroup_read_u64
,
4440 .name
= "limit_in_bytes",
4441 .private = MEMFILE_PRIVATE(_MEM
, RES_LIMIT
),
4442 .write
= mem_cgroup_write
,
4443 .read_u64
= mem_cgroup_read_u64
,
4446 .name
= "soft_limit_in_bytes",
4447 .private = MEMFILE_PRIVATE(_MEM
, RES_SOFT_LIMIT
),
4448 .write
= mem_cgroup_write
,
4449 .read_u64
= mem_cgroup_read_u64
,
4453 .private = MEMFILE_PRIVATE(_MEM
, RES_FAILCNT
),
4454 .write
= mem_cgroup_reset
,
4455 .read_u64
= mem_cgroup_read_u64
,
4459 .seq_show
= memcg_stat_show
,
4462 .name
= "force_empty",
4463 .write
= mem_cgroup_force_empty_write
,
4466 .name
= "use_hierarchy",
4467 .write_u64
= mem_cgroup_hierarchy_write
,
4468 .read_u64
= mem_cgroup_hierarchy_read
,
4471 .name
= "cgroup.event_control", /* XXX: for compat */
4472 .write
= memcg_write_event_control
,
4473 .flags
= CFTYPE_NO_PREFIX
| CFTYPE_WORLD_WRITABLE
,
4476 .name
= "swappiness",
4477 .read_u64
= mem_cgroup_swappiness_read
,
4478 .write_u64
= mem_cgroup_swappiness_write
,
4481 .name
= "move_charge_at_immigrate",
4482 .read_u64
= mem_cgroup_move_charge_read
,
4483 .write_u64
= mem_cgroup_move_charge_write
,
4486 .name
= "oom_control",
4487 .seq_show
= mem_cgroup_oom_control_read
,
4488 .write_u64
= mem_cgroup_oom_control_write
,
4489 .private = MEMFILE_PRIVATE(_OOM_TYPE
, OOM_CONTROL
),
4492 .name
= "pressure_level",
4496 .name
= "numa_stat",
4497 .seq_show
= memcg_numa_stat_show
,
4501 .name
= "kmem.limit_in_bytes",
4502 .private = MEMFILE_PRIVATE(_KMEM
, RES_LIMIT
),
4503 .write
= mem_cgroup_write
,
4504 .read_u64
= mem_cgroup_read_u64
,
4507 .name
= "kmem.usage_in_bytes",
4508 .private = MEMFILE_PRIVATE(_KMEM
, RES_USAGE
),
4509 .read_u64
= mem_cgroup_read_u64
,
4512 .name
= "kmem.failcnt",
4513 .private = MEMFILE_PRIVATE(_KMEM
, RES_FAILCNT
),
4514 .write
= mem_cgroup_reset
,
4515 .read_u64
= mem_cgroup_read_u64
,
4518 .name
= "kmem.max_usage_in_bytes",
4519 .private = MEMFILE_PRIVATE(_KMEM
, RES_MAX_USAGE
),
4520 .write
= mem_cgroup_reset
,
4521 .read_u64
= mem_cgroup_read_u64
,
4523 #if defined(CONFIG_SLAB) || defined(CONFIG_SLUB_DEBUG)
4525 .name
= "kmem.slabinfo",
4526 .seq_start
= memcg_slab_start
,
4527 .seq_next
= memcg_slab_next
,
4528 .seq_stop
= memcg_slab_stop
,
4529 .seq_show
= memcg_slab_show
,
4533 .name
= "kmem.tcp.limit_in_bytes",
4534 .private = MEMFILE_PRIVATE(_TCP
, RES_LIMIT
),
4535 .write
= mem_cgroup_write
,
4536 .read_u64
= mem_cgroup_read_u64
,
4539 .name
= "kmem.tcp.usage_in_bytes",
4540 .private = MEMFILE_PRIVATE(_TCP
, RES_USAGE
),
4541 .read_u64
= mem_cgroup_read_u64
,
4544 .name
= "kmem.tcp.failcnt",
4545 .private = MEMFILE_PRIVATE(_TCP
, RES_FAILCNT
),
4546 .write
= mem_cgroup_reset
,
4547 .read_u64
= mem_cgroup_read_u64
,
4550 .name
= "kmem.tcp.max_usage_in_bytes",
4551 .private = MEMFILE_PRIVATE(_TCP
, RES_MAX_USAGE
),
4552 .write
= mem_cgroup_reset
,
4553 .read_u64
= mem_cgroup_read_u64
,
4555 { }, /* terminate */
4559 * Private memory cgroup IDR
4561 * Swap-out records and page cache shadow entries need to store memcg
4562 * references in constrained space, so we maintain an ID space that is
4563 * limited to 16 bit (MEM_CGROUP_ID_MAX), limiting the total number of
4564 * memory-controlled cgroups to 64k.
4566 * However, there usually are many references to the oflline CSS after
4567 * the cgroup has been destroyed, such as page cache or reclaimable
4568 * slab objects, that don't need to hang on to the ID. We want to keep
4569 * those dead CSS from occupying IDs, or we might quickly exhaust the
4570 * relatively small ID space and prevent the creation of new cgroups
4571 * even when there are much fewer than 64k cgroups - possibly none.
4573 * Maintain a private 16-bit ID space for memcg, and allow the ID to
4574 * be freed and recycled when it's no longer needed, which is usually
4575 * when the CSS is offlined.
4577 * The only exception to that are records of swapped out tmpfs/shmem
4578 * pages that need to be attributed to live ancestors on swapin. But
4579 * those references are manageable from userspace.
4582 static DEFINE_IDR(mem_cgroup_idr
);
4584 static void mem_cgroup_id_remove(struct mem_cgroup
*memcg
)
4586 if (memcg
->id
.id
> 0) {
4587 idr_remove(&mem_cgroup_idr
, memcg
->id
.id
);
4592 static void mem_cgroup_id_get_many(struct mem_cgroup
*memcg
, unsigned int n
)
4594 refcount_add(n
, &memcg
->id
.ref
);
4597 static void mem_cgroup_id_put_many(struct mem_cgroup
*memcg
, unsigned int n
)
4599 if (refcount_sub_and_test(n
, &memcg
->id
.ref
)) {
4600 mem_cgroup_id_remove(memcg
);
4602 /* Memcg ID pins CSS */
4603 css_put(&memcg
->css
);
4607 static inline void mem_cgroup_id_get(struct mem_cgroup
*memcg
)
4609 mem_cgroup_id_get_many(memcg
, 1);
4612 static inline void mem_cgroup_id_put(struct mem_cgroup
*memcg
)
4614 mem_cgroup_id_put_many(memcg
, 1);
4618 * mem_cgroup_from_id - look up a memcg from a memcg id
4619 * @id: the memcg id to look up
4621 * Caller must hold rcu_read_lock().
4623 struct mem_cgroup
*mem_cgroup_from_id(unsigned short id
)
4625 WARN_ON_ONCE(!rcu_read_lock_held());
4626 return idr_find(&mem_cgroup_idr
, id
);
4629 static int alloc_mem_cgroup_per_node_info(struct mem_cgroup
*memcg
, int node
)
4631 struct mem_cgroup_per_node
*pn
;
4634 * This routine is called against possible nodes.
4635 * But it's BUG to call kmalloc() against offline node.
4637 * TODO: this routine can waste much memory for nodes which will
4638 * never be onlined. It's better to use memory hotplug callback
4641 if (!node_state(node
, N_NORMAL_MEMORY
))
4643 pn
= kzalloc_node(sizeof(*pn
), GFP_KERNEL
, tmp
);
4647 pn
->lruvec_stat_local
= alloc_percpu(struct lruvec_stat
);
4648 if (!pn
->lruvec_stat_local
) {
4653 pn
->lruvec_stat_cpu
= alloc_percpu(struct lruvec_stat
);
4654 if (!pn
->lruvec_stat_cpu
) {
4655 free_percpu(pn
->lruvec_stat_local
);
4660 lruvec_init(&pn
->lruvec
);
4661 pn
->usage_in_excess
= 0;
4662 pn
->on_tree
= false;
4665 memcg
->nodeinfo
[node
] = pn
;
4669 static void free_mem_cgroup_per_node_info(struct mem_cgroup
*memcg
, int node
)
4671 struct mem_cgroup_per_node
*pn
= memcg
->nodeinfo
[node
];
4676 free_percpu(pn
->lruvec_stat_cpu
);
4677 free_percpu(pn
->lruvec_stat_local
);
4681 static void __mem_cgroup_free(struct mem_cgroup
*memcg
)
4686 free_mem_cgroup_per_node_info(memcg
, node
);
4687 free_percpu(memcg
->vmstats_percpu
);
4688 free_percpu(memcg
->vmstats_local
);
4692 static void mem_cgroup_free(struct mem_cgroup
*memcg
)
4694 memcg_wb_domain_exit(memcg
);
4695 __mem_cgroup_free(memcg
);
4698 static struct mem_cgroup
*mem_cgroup_alloc(void)
4700 struct mem_cgroup
*memcg
;
4704 size
= sizeof(struct mem_cgroup
);
4705 size
+= nr_node_ids
* sizeof(struct mem_cgroup_per_node
*);
4707 memcg
= kzalloc(size
, GFP_KERNEL
);
4711 memcg
->id
.id
= idr_alloc(&mem_cgroup_idr
, NULL
,
4712 1, MEM_CGROUP_ID_MAX
,
4714 if (memcg
->id
.id
< 0)
4717 memcg
->vmstats_local
= alloc_percpu(struct memcg_vmstats_percpu
);
4718 if (!memcg
->vmstats_local
)
4721 memcg
->vmstats_percpu
= alloc_percpu(struct memcg_vmstats_percpu
);
4722 if (!memcg
->vmstats_percpu
)
4726 if (alloc_mem_cgroup_per_node_info(memcg
, node
))
4729 if (memcg_wb_domain_init(memcg
, GFP_KERNEL
))
4732 INIT_WORK(&memcg
->high_work
, high_work_func
);
4733 memcg
->last_scanned_node
= MAX_NUMNODES
;
4734 INIT_LIST_HEAD(&memcg
->oom_notify
);
4735 mutex_init(&memcg
->thresholds_lock
);
4736 spin_lock_init(&memcg
->move_lock
);
4737 vmpressure_init(&memcg
->vmpressure
);
4738 INIT_LIST_HEAD(&memcg
->event_list
);
4739 spin_lock_init(&memcg
->event_list_lock
);
4740 memcg
->socket_pressure
= jiffies
;
4741 #ifdef CONFIG_MEMCG_KMEM
4742 memcg
->kmemcg_id
= -1;
4744 #ifdef CONFIG_CGROUP_WRITEBACK
4745 INIT_LIST_HEAD(&memcg
->cgwb_list
);
4747 idr_replace(&mem_cgroup_idr
, memcg
, memcg
->id
.id
);
4750 mem_cgroup_id_remove(memcg
);
4751 __mem_cgroup_free(memcg
);
4755 static struct cgroup_subsys_state
* __ref
4756 mem_cgroup_css_alloc(struct cgroup_subsys_state
*parent_css
)
4758 struct mem_cgroup
*parent
= mem_cgroup_from_css(parent_css
);
4759 struct mem_cgroup
*memcg
;
4760 long error
= -ENOMEM
;
4762 memcg
= mem_cgroup_alloc();
4764 return ERR_PTR(error
);
4766 memcg
->high
= PAGE_COUNTER_MAX
;
4767 memcg
->soft_limit
= PAGE_COUNTER_MAX
;
4769 memcg
->swappiness
= mem_cgroup_swappiness(parent
);
4770 memcg
->oom_kill_disable
= parent
->oom_kill_disable
;
4772 if (parent
&& parent
->use_hierarchy
) {
4773 memcg
->use_hierarchy
= true;
4774 page_counter_init(&memcg
->memory
, &parent
->memory
);
4775 page_counter_init(&memcg
->swap
, &parent
->swap
);
4776 page_counter_init(&memcg
->memsw
, &parent
->memsw
);
4777 page_counter_init(&memcg
->kmem
, &parent
->kmem
);
4778 page_counter_init(&memcg
->tcpmem
, &parent
->tcpmem
);
4780 page_counter_init(&memcg
->memory
, NULL
);
4781 page_counter_init(&memcg
->swap
, NULL
);
4782 page_counter_init(&memcg
->memsw
, NULL
);
4783 page_counter_init(&memcg
->kmem
, NULL
);
4784 page_counter_init(&memcg
->tcpmem
, NULL
);
4786 * Deeper hierachy with use_hierarchy == false doesn't make
4787 * much sense so let cgroup subsystem know about this
4788 * unfortunate state in our controller.
4790 if (parent
!= root_mem_cgroup
)
4791 memory_cgrp_subsys
.broken_hierarchy
= true;
4794 /* The following stuff does not apply to the root */
4796 #ifdef CONFIG_MEMCG_KMEM
4797 INIT_LIST_HEAD(&memcg
->kmem_caches
);
4799 root_mem_cgroup
= memcg
;
4803 error
= memcg_online_kmem(memcg
);
4807 if (cgroup_subsys_on_dfl(memory_cgrp_subsys
) && !cgroup_memory_nosocket
)
4808 static_branch_inc(&memcg_sockets_enabled_key
);
4812 mem_cgroup_id_remove(memcg
);
4813 mem_cgroup_free(memcg
);
4814 return ERR_PTR(-ENOMEM
);
4817 static int mem_cgroup_css_online(struct cgroup_subsys_state
*css
)
4819 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
4822 * A memcg must be visible for memcg_expand_shrinker_maps()
4823 * by the time the maps are allocated. So, we allocate maps
4824 * here, when for_each_mem_cgroup() can't skip it.
4826 if (memcg_alloc_shrinker_maps(memcg
)) {
4827 mem_cgroup_id_remove(memcg
);
4831 /* Online state pins memcg ID, memcg ID pins CSS */
4832 refcount_set(&memcg
->id
.ref
, 1);
4837 static void mem_cgroup_css_offline(struct cgroup_subsys_state
*css
)
4839 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
4840 struct mem_cgroup_event
*event
, *tmp
;
4843 * Unregister events and notify userspace.
4844 * Notify userspace about cgroup removing only after rmdir of cgroup
4845 * directory to avoid race between userspace and kernelspace.
4847 spin_lock(&memcg
->event_list_lock
);
4848 list_for_each_entry_safe(event
, tmp
, &memcg
->event_list
, list
) {
4849 list_del_init(&event
->list
);
4850 schedule_work(&event
->remove
);
4852 spin_unlock(&memcg
->event_list_lock
);
4854 page_counter_set_min(&memcg
->memory
, 0);
4855 page_counter_set_low(&memcg
->memory
, 0);
4857 memcg_offline_kmem(memcg
);
4858 wb_memcg_offline(memcg
);
4860 drain_all_stock(memcg
);
4862 mem_cgroup_id_put(memcg
);
4865 static void mem_cgroup_css_released(struct cgroup_subsys_state
*css
)
4867 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
4869 invalidate_reclaim_iterators(memcg
);
4872 static void mem_cgroup_css_free(struct cgroup_subsys_state
*css
)
4874 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
4876 if (cgroup_subsys_on_dfl(memory_cgrp_subsys
) && !cgroup_memory_nosocket
)
4877 static_branch_dec(&memcg_sockets_enabled_key
);
4879 if (!cgroup_subsys_on_dfl(memory_cgrp_subsys
) && memcg
->tcpmem_active
)
4880 static_branch_dec(&memcg_sockets_enabled_key
);
4882 vmpressure_cleanup(&memcg
->vmpressure
);
4883 cancel_work_sync(&memcg
->high_work
);
4884 mem_cgroup_remove_from_trees(memcg
);
4885 memcg_free_shrinker_maps(memcg
);
4886 memcg_free_kmem(memcg
);
4887 mem_cgroup_free(memcg
);
4891 * mem_cgroup_css_reset - reset the states of a mem_cgroup
4892 * @css: the target css
4894 * Reset the states of the mem_cgroup associated with @css. This is
4895 * invoked when the userland requests disabling on the default hierarchy
4896 * but the memcg is pinned through dependency. The memcg should stop
4897 * applying policies and should revert to the vanilla state as it may be
4898 * made visible again.
4900 * The current implementation only resets the essential configurations.
4901 * This needs to be expanded to cover all the visible parts.
4903 static void mem_cgroup_css_reset(struct cgroup_subsys_state
*css
)
4905 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
4907 page_counter_set_max(&memcg
->memory
, PAGE_COUNTER_MAX
);
4908 page_counter_set_max(&memcg
->swap
, PAGE_COUNTER_MAX
);
4909 page_counter_set_max(&memcg
->memsw
, PAGE_COUNTER_MAX
);
4910 page_counter_set_max(&memcg
->kmem
, PAGE_COUNTER_MAX
);
4911 page_counter_set_max(&memcg
->tcpmem
, PAGE_COUNTER_MAX
);
4912 page_counter_set_min(&memcg
->memory
, 0);
4913 page_counter_set_low(&memcg
->memory
, 0);
4914 memcg
->high
= PAGE_COUNTER_MAX
;
4915 memcg
->soft_limit
= PAGE_COUNTER_MAX
;
4916 memcg_wb_domain_size_changed(memcg
);
4920 /* Handlers for move charge at task migration. */
4921 static int mem_cgroup_do_precharge(unsigned long count
)
4925 /* Try a single bulk charge without reclaim first, kswapd may wake */
4926 ret
= try_charge(mc
.to
, GFP_KERNEL
& ~__GFP_DIRECT_RECLAIM
, count
);
4928 mc
.precharge
+= count
;
4932 /* Try charges one by one with reclaim, but do not retry */
4934 ret
= try_charge(mc
.to
, GFP_KERNEL
| __GFP_NORETRY
, 1);
4948 enum mc_target_type
{
4955 static struct page
*mc_handle_present_pte(struct vm_area_struct
*vma
,
4956 unsigned long addr
, pte_t ptent
)
4958 struct page
*page
= vm_normal_page(vma
, addr
, ptent
);
4960 if (!page
|| !page_mapped(page
))
4962 if (PageAnon(page
)) {
4963 if (!(mc
.flags
& MOVE_ANON
))
4966 if (!(mc
.flags
& MOVE_FILE
))
4969 if (!get_page_unless_zero(page
))
4975 #if defined(CONFIG_SWAP) || defined(CONFIG_DEVICE_PRIVATE)
4976 static struct page
*mc_handle_swap_pte(struct vm_area_struct
*vma
,
4977 pte_t ptent
, swp_entry_t
*entry
)
4979 struct page
*page
= NULL
;
4980 swp_entry_t ent
= pte_to_swp_entry(ptent
);
4982 if (!(mc
.flags
& MOVE_ANON
) || non_swap_entry(ent
))
4986 * Handle MEMORY_DEVICE_PRIVATE which are ZONE_DEVICE page belonging to
4987 * a device and because they are not accessible by CPU they are store
4988 * as special swap entry in the CPU page table.
4990 if (is_device_private_entry(ent
)) {
4991 page
= device_private_entry_to_page(ent
);
4993 * MEMORY_DEVICE_PRIVATE means ZONE_DEVICE page and which have
4994 * a refcount of 1 when free (unlike normal page)
4996 if (!page_ref_add_unless(page
, 1, 1))
5002 * Because lookup_swap_cache() updates some statistics counter,
5003 * we call find_get_page() with swapper_space directly.
5005 page
= find_get_page(swap_address_space(ent
), swp_offset(ent
));
5006 if (do_memsw_account())
5007 entry
->val
= ent
.val
;
5012 static struct page
*mc_handle_swap_pte(struct vm_area_struct
*vma
,
5013 pte_t ptent
, swp_entry_t
*entry
)
5019 static struct page
*mc_handle_file_pte(struct vm_area_struct
*vma
,
5020 unsigned long addr
, pte_t ptent
, swp_entry_t
*entry
)
5022 struct page
*page
= NULL
;
5023 struct address_space
*mapping
;
5026 if (!vma
->vm_file
) /* anonymous vma */
5028 if (!(mc
.flags
& MOVE_FILE
))
5031 mapping
= vma
->vm_file
->f_mapping
;
5032 pgoff
= linear_page_index(vma
, addr
);
5034 /* page is moved even if it's not RSS of this task(page-faulted). */
5036 /* shmem/tmpfs may report page out on swap: account for that too. */
5037 if (shmem_mapping(mapping
)) {
5038 page
= find_get_entry(mapping
, pgoff
);
5039 if (xa_is_value(page
)) {
5040 swp_entry_t swp
= radix_to_swp_entry(page
);
5041 if (do_memsw_account())
5043 page
= find_get_page(swap_address_space(swp
),
5047 page
= find_get_page(mapping
, pgoff
);
5049 page
= find_get_page(mapping
, pgoff
);
5055 * mem_cgroup_move_account - move account of the page
5057 * @compound: charge the page as compound or small page
5058 * @from: mem_cgroup which the page is moved from.
5059 * @to: mem_cgroup which the page is moved to. @from != @to.
5061 * The caller must make sure the page is not on LRU (isolate_page() is useful.)
5063 * This function doesn't do "charge" to new cgroup and doesn't do "uncharge"
5066 static int mem_cgroup_move_account(struct page
*page
,
5068 struct mem_cgroup
*from
,
5069 struct mem_cgroup
*to
)
5071 unsigned long flags
;
5072 unsigned int nr_pages
= compound
? hpage_nr_pages(page
) : 1;
5076 VM_BUG_ON(from
== to
);
5077 VM_BUG_ON_PAGE(PageLRU(page
), page
);
5078 VM_BUG_ON(compound
&& !PageTransHuge(page
));
5081 * Prevent mem_cgroup_migrate() from looking at
5082 * page->mem_cgroup of its source page while we change it.
5085 if (!trylock_page(page
))
5089 if (page
->mem_cgroup
!= from
)
5092 anon
= PageAnon(page
);
5094 spin_lock_irqsave(&from
->move_lock
, flags
);
5096 if (!anon
&& page_mapped(page
)) {
5097 __mod_memcg_state(from
, NR_FILE_MAPPED
, -nr_pages
);
5098 __mod_memcg_state(to
, NR_FILE_MAPPED
, nr_pages
);
5102 * move_lock grabbed above and caller set from->moving_account, so
5103 * mod_memcg_page_state will serialize updates to PageDirty.
5104 * So mapping should be stable for dirty pages.
5106 if (!anon
&& PageDirty(page
)) {
5107 struct address_space
*mapping
= page_mapping(page
);
5109 if (mapping_cap_account_dirty(mapping
)) {
5110 __mod_memcg_state(from
, NR_FILE_DIRTY
, -nr_pages
);
5111 __mod_memcg_state(to
, NR_FILE_DIRTY
, nr_pages
);
5115 if (PageWriteback(page
)) {
5116 __mod_memcg_state(from
, NR_WRITEBACK
, -nr_pages
);
5117 __mod_memcg_state(to
, NR_WRITEBACK
, nr_pages
);
5121 * It is safe to change page->mem_cgroup here because the page
5122 * is referenced, charged, and isolated - we can't race with
5123 * uncharging, charging, migration, or LRU putback.
5126 /* caller should have done css_get */
5127 page
->mem_cgroup
= to
;
5128 spin_unlock_irqrestore(&from
->move_lock
, flags
);
5132 local_irq_disable();
5133 mem_cgroup_charge_statistics(to
, page
, compound
, nr_pages
);
5134 memcg_check_events(to
, page
);
5135 mem_cgroup_charge_statistics(from
, page
, compound
, -nr_pages
);
5136 memcg_check_events(from
, page
);
5145 * get_mctgt_type - get target type of moving charge
5146 * @vma: the vma the pte to be checked belongs
5147 * @addr: the address corresponding to the pte to be checked
5148 * @ptent: the pte to be checked
5149 * @target: the pointer the target page or swap ent will be stored(can be NULL)
5152 * 0(MC_TARGET_NONE): if the pte is not a target for move charge.
5153 * 1(MC_TARGET_PAGE): if the page corresponding to this pte is a target for
5154 * move charge. if @target is not NULL, the page is stored in target->page
5155 * with extra refcnt got(Callers should handle it).
5156 * 2(MC_TARGET_SWAP): if the swap entry corresponding to this pte is a
5157 * target for charge migration. if @target is not NULL, the entry is stored
5159 * 3(MC_TARGET_DEVICE): like MC_TARGET_PAGE but page is MEMORY_DEVICE_PRIVATE
5160 * (so ZONE_DEVICE page and thus not on the lru).
5161 * For now we such page is charge like a regular page would be as for all
5162 * intent and purposes it is just special memory taking the place of a
5165 * See Documentations/vm/hmm.txt and include/linux/hmm.h
5167 * Called with pte lock held.
5170 static enum mc_target_type
get_mctgt_type(struct vm_area_struct
*vma
,
5171 unsigned long addr
, pte_t ptent
, union mc_target
*target
)
5173 struct page
*page
= NULL
;
5174 enum mc_target_type ret
= MC_TARGET_NONE
;
5175 swp_entry_t ent
= { .val
= 0 };
5177 if (pte_present(ptent
))
5178 page
= mc_handle_present_pte(vma
, addr
, ptent
);
5179 else if (is_swap_pte(ptent
))
5180 page
= mc_handle_swap_pte(vma
, ptent
, &ent
);
5181 else if (pte_none(ptent
))
5182 page
= mc_handle_file_pte(vma
, addr
, ptent
, &ent
);
5184 if (!page
&& !ent
.val
)
5188 * Do only loose check w/o serialization.
5189 * mem_cgroup_move_account() checks the page is valid or
5190 * not under LRU exclusion.
5192 if (page
->mem_cgroup
== mc
.from
) {
5193 ret
= MC_TARGET_PAGE
;
5194 if (is_device_private_page(page
))
5195 ret
= MC_TARGET_DEVICE
;
5197 target
->page
= page
;
5199 if (!ret
|| !target
)
5203 * There is a swap entry and a page doesn't exist or isn't charged.
5204 * But we cannot move a tail-page in a THP.
5206 if (ent
.val
&& !ret
&& (!page
|| !PageTransCompound(page
)) &&
5207 mem_cgroup_id(mc
.from
) == lookup_swap_cgroup_id(ent
)) {
5208 ret
= MC_TARGET_SWAP
;
5215 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
5217 * We don't consider PMD mapped swapping or file mapped pages because THP does
5218 * not support them for now.
5219 * Caller should make sure that pmd_trans_huge(pmd) is true.
5221 static enum mc_target_type
get_mctgt_type_thp(struct vm_area_struct
*vma
,
5222 unsigned long addr
, pmd_t pmd
, union mc_target
*target
)
5224 struct page
*page
= NULL
;
5225 enum mc_target_type ret
= MC_TARGET_NONE
;
5227 if (unlikely(is_swap_pmd(pmd
))) {
5228 VM_BUG_ON(thp_migration_supported() &&
5229 !is_pmd_migration_entry(pmd
));
5232 page
= pmd_page(pmd
);
5233 VM_BUG_ON_PAGE(!page
|| !PageHead(page
), page
);
5234 if (!(mc
.flags
& MOVE_ANON
))
5236 if (page
->mem_cgroup
== mc
.from
) {
5237 ret
= MC_TARGET_PAGE
;
5240 target
->page
= page
;
5246 static inline enum mc_target_type
get_mctgt_type_thp(struct vm_area_struct
*vma
,
5247 unsigned long addr
, pmd_t pmd
, union mc_target
*target
)
5249 return MC_TARGET_NONE
;
5253 static int mem_cgroup_count_precharge_pte_range(pmd_t
*pmd
,
5254 unsigned long addr
, unsigned long end
,
5255 struct mm_walk
*walk
)
5257 struct vm_area_struct
*vma
= walk
->vma
;
5261 ptl
= pmd_trans_huge_lock(pmd
, vma
);
5264 * Note their can not be MC_TARGET_DEVICE for now as we do not
5265 * support transparent huge page with MEMORY_DEVICE_PRIVATE but
5266 * this might change.
5268 if (get_mctgt_type_thp(vma
, addr
, *pmd
, NULL
) == MC_TARGET_PAGE
)
5269 mc
.precharge
+= HPAGE_PMD_NR
;
5274 if (pmd_trans_unstable(pmd
))
5276 pte
= pte_offset_map_lock(vma
->vm_mm
, pmd
, addr
, &ptl
);
5277 for (; addr
!= end
; pte
++, addr
+= PAGE_SIZE
)
5278 if (get_mctgt_type(vma
, addr
, *pte
, NULL
))
5279 mc
.precharge
++; /* increment precharge temporarily */
5280 pte_unmap_unlock(pte
- 1, ptl
);
5286 static unsigned long mem_cgroup_count_precharge(struct mm_struct
*mm
)
5288 unsigned long precharge
;
5290 struct mm_walk mem_cgroup_count_precharge_walk
= {
5291 .pmd_entry
= mem_cgroup_count_precharge_pte_range
,
5294 down_read(&mm
->mmap_sem
);
5295 walk_page_range(0, mm
->highest_vm_end
,
5296 &mem_cgroup_count_precharge_walk
);
5297 up_read(&mm
->mmap_sem
);
5299 precharge
= mc
.precharge
;
5305 static int mem_cgroup_precharge_mc(struct mm_struct
*mm
)
5307 unsigned long precharge
= mem_cgroup_count_precharge(mm
);
5309 VM_BUG_ON(mc
.moving_task
);
5310 mc
.moving_task
= current
;
5311 return mem_cgroup_do_precharge(precharge
);
5314 /* cancels all extra charges on mc.from and mc.to, and wakes up all waiters. */
5315 static void __mem_cgroup_clear_mc(void)
5317 struct mem_cgroup
*from
= mc
.from
;
5318 struct mem_cgroup
*to
= mc
.to
;
5320 /* we must uncharge all the leftover precharges from mc.to */
5322 cancel_charge(mc
.to
, mc
.precharge
);
5326 * we didn't uncharge from mc.from at mem_cgroup_move_account(), so
5327 * we must uncharge here.
5329 if (mc
.moved_charge
) {
5330 cancel_charge(mc
.from
, mc
.moved_charge
);
5331 mc
.moved_charge
= 0;
5333 /* we must fixup refcnts and charges */
5334 if (mc
.moved_swap
) {
5335 /* uncharge swap account from the old cgroup */
5336 if (!mem_cgroup_is_root(mc
.from
))
5337 page_counter_uncharge(&mc
.from
->memsw
, mc
.moved_swap
);
5339 mem_cgroup_id_put_many(mc
.from
, mc
.moved_swap
);
5342 * we charged both to->memory and to->memsw, so we
5343 * should uncharge to->memory.
5345 if (!mem_cgroup_is_root(mc
.to
))
5346 page_counter_uncharge(&mc
.to
->memory
, mc
.moved_swap
);
5348 mem_cgroup_id_get_many(mc
.to
, mc
.moved_swap
);
5349 css_put_many(&mc
.to
->css
, mc
.moved_swap
);
5353 memcg_oom_recover(from
);
5354 memcg_oom_recover(to
);
5355 wake_up_all(&mc
.waitq
);
5358 static void mem_cgroup_clear_mc(void)
5360 struct mm_struct
*mm
= mc
.mm
;
5363 * we must clear moving_task before waking up waiters at the end of
5366 mc
.moving_task
= NULL
;
5367 __mem_cgroup_clear_mc();
5368 spin_lock(&mc
.lock
);
5372 spin_unlock(&mc
.lock
);
5377 static int mem_cgroup_can_attach(struct cgroup_taskset
*tset
)
5379 struct cgroup_subsys_state
*css
;
5380 struct mem_cgroup
*memcg
= NULL
; /* unneeded init to make gcc happy */
5381 struct mem_cgroup
*from
;
5382 struct task_struct
*leader
, *p
;
5383 struct mm_struct
*mm
;
5384 unsigned long move_flags
;
5387 /* charge immigration isn't supported on the default hierarchy */
5388 if (cgroup_subsys_on_dfl(memory_cgrp_subsys
))
5392 * Multi-process migrations only happen on the default hierarchy
5393 * where charge immigration is not used. Perform charge
5394 * immigration if @tset contains a leader and whine if there are
5398 cgroup_taskset_for_each_leader(leader
, css
, tset
) {
5401 memcg
= mem_cgroup_from_css(css
);
5407 * We are now commited to this value whatever it is. Changes in this
5408 * tunable will only affect upcoming migrations, not the current one.
5409 * So we need to save it, and keep it going.
5411 move_flags
= READ_ONCE(memcg
->move_charge_at_immigrate
);
5415 from
= mem_cgroup_from_task(p
);
5417 VM_BUG_ON(from
== memcg
);
5419 mm
= get_task_mm(p
);
5422 /* We move charges only when we move a owner of the mm */
5423 if (mm
->owner
== p
) {
5426 VM_BUG_ON(mc
.precharge
);
5427 VM_BUG_ON(mc
.moved_charge
);
5428 VM_BUG_ON(mc
.moved_swap
);
5430 spin_lock(&mc
.lock
);
5434 mc
.flags
= move_flags
;
5435 spin_unlock(&mc
.lock
);
5436 /* We set mc.moving_task later */
5438 ret
= mem_cgroup_precharge_mc(mm
);
5440 mem_cgroup_clear_mc();
5447 static void mem_cgroup_cancel_attach(struct cgroup_taskset
*tset
)
5450 mem_cgroup_clear_mc();
5453 static int mem_cgroup_move_charge_pte_range(pmd_t
*pmd
,
5454 unsigned long addr
, unsigned long end
,
5455 struct mm_walk
*walk
)
5458 struct vm_area_struct
*vma
= walk
->vma
;
5461 enum mc_target_type target_type
;
5462 union mc_target target
;
5465 ptl
= pmd_trans_huge_lock(pmd
, vma
);
5467 if (mc
.precharge
< HPAGE_PMD_NR
) {
5471 target_type
= get_mctgt_type_thp(vma
, addr
, *pmd
, &target
);
5472 if (target_type
== MC_TARGET_PAGE
) {
5474 if (!isolate_lru_page(page
)) {
5475 if (!mem_cgroup_move_account(page
, true,
5477 mc
.precharge
-= HPAGE_PMD_NR
;
5478 mc
.moved_charge
+= HPAGE_PMD_NR
;
5480 putback_lru_page(page
);
5483 } else if (target_type
== MC_TARGET_DEVICE
) {
5485 if (!mem_cgroup_move_account(page
, true,
5487 mc
.precharge
-= HPAGE_PMD_NR
;
5488 mc
.moved_charge
+= HPAGE_PMD_NR
;
5496 if (pmd_trans_unstable(pmd
))
5499 pte
= pte_offset_map_lock(vma
->vm_mm
, pmd
, addr
, &ptl
);
5500 for (; addr
!= end
; addr
+= PAGE_SIZE
) {
5501 pte_t ptent
= *(pte
++);
5502 bool device
= false;
5508 switch (get_mctgt_type(vma
, addr
, ptent
, &target
)) {
5509 case MC_TARGET_DEVICE
:
5512 case MC_TARGET_PAGE
:
5515 * We can have a part of the split pmd here. Moving it
5516 * can be done but it would be too convoluted so simply
5517 * ignore such a partial THP and keep it in original
5518 * memcg. There should be somebody mapping the head.
5520 if (PageTransCompound(page
))
5522 if (!device
&& isolate_lru_page(page
))
5524 if (!mem_cgroup_move_account(page
, false,
5527 /* we uncharge from mc.from later. */
5531 putback_lru_page(page
);
5532 put
: /* get_mctgt_type() gets the page */
5535 case MC_TARGET_SWAP
:
5537 if (!mem_cgroup_move_swap_account(ent
, mc
.from
, mc
.to
)) {
5539 /* we fixup refcnts and charges later. */
5547 pte_unmap_unlock(pte
- 1, ptl
);
5552 * We have consumed all precharges we got in can_attach().
5553 * We try charge one by one, but don't do any additional
5554 * charges to mc.to if we have failed in charge once in attach()
5557 ret
= mem_cgroup_do_precharge(1);
5565 static void mem_cgroup_move_charge(void)
5567 struct mm_walk mem_cgroup_move_charge_walk
= {
5568 .pmd_entry
= mem_cgroup_move_charge_pte_range
,
5572 lru_add_drain_all();
5574 * Signal lock_page_memcg() to take the memcg's move_lock
5575 * while we're moving its pages to another memcg. Then wait
5576 * for already started RCU-only updates to finish.
5578 atomic_inc(&mc
.from
->moving_account
);
5581 if (unlikely(!down_read_trylock(&mc
.mm
->mmap_sem
))) {
5583 * Someone who are holding the mmap_sem might be waiting in
5584 * waitq. So we cancel all extra charges, wake up all waiters,
5585 * and retry. Because we cancel precharges, we might not be able
5586 * to move enough charges, but moving charge is a best-effort
5587 * feature anyway, so it wouldn't be a big problem.
5589 __mem_cgroup_clear_mc();
5594 * When we have consumed all precharges and failed in doing
5595 * additional charge, the page walk just aborts.
5597 walk_page_range(0, mc
.mm
->highest_vm_end
, &mem_cgroup_move_charge_walk
);
5599 up_read(&mc
.mm
->mmap_sem
);
5600 atomic_dec(&mc
.from
->moving_account
);
5603 static void mem_cgroup_move_task(void)
5606 mem_cgroup_move_charge();
5607 mem_cgroup_clear_mc();
5610 #else /* !CONFIG_MMU */
5611 static int mem_cgroup_can_attach(struct cgroup_taskset
*tset
)
5615 static void mem_cgroup_cancel_attach(struct cgroup_taskset
*tset
)
5618 static void mem_cgroup_move_task(void)
5624 * Cgroup retains root cgroups across [un]mount cycles making it necessary
5625 * to verify whether we're attached to the default hierarchy on each mount
5628 static void mem_cgroup_bind(struct cgroup_subsys_state
*root_css
)
5631 * use_hierarchy is forced on the default hierarchy. cgroup core
5632 * guarantees that @root doesn't have any children, so turning it
5633 * on for the root memcg is enough.
5635 if (cgroup_subsys_on_dfl(memory_cgrp_subsys
))
5636 root_mem_cgroup
->use_hierarchy
= true;
5638 root_mem_cgroup
->use_hierarchy
= false;
5641 static int seq_puts_memcg_tunable(struct seq_file
*m
, unsigned long value
)
5643 if (value
== PAGE_COUNTER_MAX
)
5644 seq_puts(m
, "max\n");
5646 seq_printf(m
, "%llu\n", (u64
)value
* PAGE_SIZE
);
5651 static u64
memory_current_read(struct cgroup_subsys_state
*css
,
5654 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
5656 return (u64
)page_counter_read(&memcg
->memory
) * PAGE_SIZE
;
5659 static int memory_min_show(struct seq_file
*m
, void *v
)
5661 return seq_puts_memcg_tunable(m
,
5662 READ_ONCE(mem_cgroup_from_seq(m
)->memory
.min
));
5665 static ssize_t
memory_min_write(struct kernfs_open_file
*of
,
5666 char *buf
, size_t nbytes
, loff_t off
)
5668 struct mem_cgroup
*memcg
= mem_cgroup_from_css(of_css(of
));
5672 buf
= strstrip(buf
);
5673 err
= page_counter_memparse(buf
, "max", &min
);
5677 page_counter_set_min(&memcg
->memory
, min
);
5682 static int memory_low_show(struct seq_file
*m
, void *v
)
5684 return seq_puts_memcg_tunable(m
,
5685 READ_ONCE(mem_cgroup_from_seq(m
)->memory
.low
));
5688 static ssize_t
memory_low_write(struct kernfs_open_file
*of
,
5689 char *buf
, size_t nbytes
, loff_t off
)
5691 struct mem_cgroup
*memcg
= mem_cgroup_from_css(of_css(of
));
5695 buf
= strstrip(buf
);
5696 err
= page_counter_memparse(buf
, "max", &low
);
5700 page_counter_set_low(&memcg
->memory
, low
);
5705 static int memory_high_show(struct seq_file
*m
, void *v
)
5707 return seq_puts_memcg_tunable(m
, READ_ONCE(mem_cgroup_from_seq(m
)->high
));
5710 static ssize_t
memory_high_write(struct kernfs_open_file
*of
,
5711 char *buf
, size_t nbytes
, loff_t off
)
5713 struct mem_cgroup
*memcg
= mem_cgroup_from_css(of_css(of
));
5714 unsigned long nr_pages
;
5718 buf
= strstrip(buf
);
5719 err
= page_counter_memparse(buf
, "max", &high
);
5725 nr_pages
= page_counter_read(&memcg
->memory
);
5726 if (nr_pages
> high
)
5727 try_to_free_mem_cgroup_pages(memcg
, nr_pages
- high
,
5730 memcg_wb_domain_size_changed(memcg
);
5734 static int memory_max_show(struct seq_file
*m
, void *v
)
5736 return seq_puts_memcg_tunable(m
,
5737 READ_ONCE(mem_cgroup_from_seq(m
)->memory
.max
));
5740 static ssize_t
memory_max_write(struct kernfs_open_file
*of
,
5741 char *buf
, size_t nbytes
, loff_t off
)
5743 struct mem_cgroup
*memcg
= mem_cgroup_from_css(of_css(of
));
5744 unsigned int nr_reclaims
= MEM_CGROUP_RECLAIM_RETRIES
;
5745 bool drained
= false;
5749 buf
= strstrip(buf
);
5750 err
= page_counter_memparse(buf
, "max", &max
);
5754 xchg(&memcg
->memory
.max
, max
);
5757 unsigned long nr_pages
= page_counter_read(&memcg
->memory
);
5759 if (nr_pages
<= max
)
5762 if (signal_pending(current
)) {
5768 drain_all_stock(memcg
);
5774 if (!try_to_free_mem_cgroup_pages(memcg
, nr_pages
- max
,
5780 memcg_memory_event(memcg
, MEMCG_OOM
);
5781 if (!mem_cgroup_out_of_memory(memcg
, GFP_KERNEL
, 0))
5785 memcg_wb_domain_size_changed(memcg
);
5789 static void __memory_events_show(struct seq_file
*m
, atomic_long_t
*events
)
5791 seq_printf(m
, "low %lu\n", atomic_long_read(&events
[MEMCG_LOW
]));
5792 seq_printf(m
, "high %lu\n", atomic_long_read(&events
[MEMCG_HIGH
]));
5793 seq_printf(m
, "max %lu\n", atomic_long_read(&events
[MEMCG_MAX
]));
5794 seq_printf(m
, "oom %lu\n", atomic_long_read(&events
[MEMCG_OOM
]));
5795 seq_printf(m
, "oom_kill %lu\n",
5796 atomic_long_read(&events
[MEMCG_OOM_KILL
]));
5799 static int memory_events_show(struct seq_file
*m
, void *v
)
5801 struct mem_cgroup
*memcg
= mem_cgroup_from_seq(m
);
5803 __memory_events_show(m
, memcg
->memory_events
);
5807 static int memory_events_local_show(struct seq_file
*m
, void *v
)
5809 struct mem_cgroup
*memcg
= mem_cgroup_from_seq(m
);
5811 __memory_events_show(m
, memcg
->memory_events_local
);
5815 static int memory_stat_show(struct seq_file
*m
, void *v
)
5817 struct mem_cgroup
*memcg
= mem_cgroup_from_seq(m
);
5820 buf
= memory_stat_format(memcg
);
5828 static int memory_oom_group_show(struct seq_file
*m
, void *v
)
5830 struct mem_cgroup
*memcg
= mem_cgroup_from_seq(m
);
5832 seq_printf(m
, "%d\n", memcg
->oom_group
);
5837 static ssize_t
memory_oom_group_write(struct kernfs_open_file
*of
,
5838 char *buf
, size_t nbytes
, loff_t off
)
5840 struct mem_cgroup
*memcg
= mem_cgroup_from_css(of_css(of
));
5843 buf
= strstrip(buf
);
5847 ret
= kstrtoint(buf
, 0, &oom_group
);
5851 if (oom_group
!= 0 && oom_group
!= 1)
5854 memcg
->oom_group
= oom_group
;
5859 static struct cftype memory_files
[] = {
5862 .flags
= CFTYPE_NOT_ON_ROOT
,
5863 .read_u64
= memory_current_read
,
5867 .flags
= CFTYPE_NOT_ON_ROOT
,
5868 .seq_show
= memory_min_show
,
5869 .write
= memory_min_write
,
5873 .flags
= CFTYPE_NOT_ON_ROOT
,
5874 .seq_show
= memory_low_show
,
5875 .write
= memory_low_write
,
5879 .flags
= CFTYPE_NOT_ON_ROOT
,
5880 .seq_show
= memory_high_show
,
5881 .write
= memory_high_write
,
5885 .flags
= CFTYPE_NOT_ON_ROOT
,
5886 .seq_show
= memory_max_show
,
5887 .write
= memory_max_write
,
5891 .flags
= CFTYPE_NOT_ON_ROOT
,
5892 .file_offset
= offsetof(struct mem_cgroup
, events_file
),
5893 .seq_show
= memory_events_show
,
5896 .name
= "events.local",
5897 .flags
= CFTYPE_NOT_ON_ROOT
,
5898 .file_offset
= offsetof(struct mem_cgroup
, events_local_file
),
5899 .seq_show
= memory_events_local_show
,
5903 .flags
= CFTYPE_NOT_ON_ROOT
,
5904 .seq_show
= memory_stat_show
,
5907 .name
= "oom.group",
5908 .flags
= CFTYPE_NOT_ON_ROOT
| CFTYPE_NS_DELEGATABLE
,
5909 .seq_show
= memory_oom_group_show
,
5910 .write
= memory_oom_group_write
,
5915 struct cgroup_subsys memory_cgrp_subsys
= {
5916 .css_alloc
= mem_cgroup_css_alloc
,
5917 .css_online
= mem_cgroup_css_online
,
5918 .css_offline
= mem_cgroup_css_offline
,
5919 .css_released
= mem_cgroup_css_released
,
5920 .css_free
= mem_cgroup_css_free
,
5921 .css_reset
= mem_cgroup_css_reset
,
5922 .can_attach
= mem_cgroup_can_attach
,
5923 .cancel_attach
= mem_cgroup_cancel_attach
,
5924 .post_attach
= mem_cgroup_move_task
,
5925 .bind
= mem_cgroup_bind
,
5926 .dfl_cftypes
= memory_files
,
5927 .legacy_cftypes
= mem_cgroup_legacy_files
,
5932 * mem_cgroup_protected - check if memory consumption is in the normal range
5933 * @root: the top ancestor of the sub-tree being checked
5934 * @memcg: the memory cgroup to check
5936 * WARNING: This function is not stateless! It can only be used as part
5937 * of a top-down tree iteration, not for isolated queries.
5939 * Returns one of the following:
5940 * MEMCG_PROT_NONE: cgroup memory is not protected
5941 * MEMCG_PROT_LOW: cgroup memory is protected as long there is
5942 * an unprotected supply of reclaimable memory from other cgroups.
5943 * MEMCG_PROT_MIN: cgroup memory is protected
5945 * @root is exclusive; it is never protected when looked at directly
5947 * To provide a proper hierarchical behavior, effective memory.min/low values
5948 * are used. Below is the description of how effective memory.low is calculated.
5949 * Effective memory.min values is calculated in the same way.
5951 * Effective memory.low is always equal or less than the original memory.low.
5952 * If there is no memory.low overcommittment (which is always true for
5953 * top-level memory cgroups), these two values are equal.
5954 * Otherwise, it's a part of parent's effective memory.low,
5955 * calculated as a cgroup's memory.low usage divided by sum of sibling's
5956 * memory.low usages, where memory.low usage is the size of actually
5960 * elow = min( memory.low, parent->elow * ------------------ ),
5961 * siblings_low_usage
5963 * | memory.current, if memory.current < memory.low
5968 * Such definition of the effective memory.low provides the expected
5969 * hierarchical behavior: parent's memory.low value is limiting
5970 * children, unprotected memory is reclaimed first and cgroups,
5971 * which are not using their guarantee do not affect actual memory
5974 * For example, if there are memcgs A, A/B, A/C, A/D and A/E:
5976 * A A/memory.low = 2G, A/memory.current = 6G
5978 * BC DE B/memory.low = 3G B/memory.current = 2G
5979 * C/memory.low = 1G C/memory.current = 2G
5980 * D/memory.low = 0 D/memory.current = 2G
5981 * E/memory.low = 10G E/memory.current = 0
5983 * and the memory pressure is applied, the following memory distribution
5984 * is expected (approximately):
5986 * A/memory.current = 2G
5988 * B/memory.current = 1.3G
5989 * C/memory.current = 0.6G
5990 * D/memory.current = 0
5991 * E/memory.current = 0
5993 * These calculations require constant tracking of the actual low usages
5994 * (see propagate_protected_usage()), as well as recursive calculation of
5995 * effective memory.low values. But as we do call mem_cgroup_protected()
5996 * path for each memory cgroup top-down from the reclaim,
5997 * it's possible to optimize this part, and save calculated elow
5998 * for next usage. This part is intentionally racy, but it's ok,
5999 * as memory.low is a best-effort mechanism.
6001 enum mem_cgroup_protection
mem_cgroup_protected(struct mem_cgroup
*root
,
6002 struct mem_cgroup
*memcg
)
6004 struct mem_cgroup
*parent
;
6005 unsigned long emin
, parent_emin
;
6006 unsigned long elow
, parent_elow
;
6007 unsigned long usage
;
6009 if (mem_cgroup_disabled())
6010 return MEMCG_PROT_NONE
;
6013 root
= root_mem_cgroup
;
6015 return MEMCG_PROT_NONE
;
6017 usage
= page_counter_read(&memcg
->memory
);
6019 return MEMCG_PROT_NONE
;
6021 emin
= memcg
->memory
.min
;
6022 elow
= memcg
->memory
.low
;
6024 parent
= parent_mem_cgroup(memcg
);
6025 /* No parent means a non-hierarchical mode on v1 memcg */
6027 return MEMCG_PROT_NONE
;
6032 parent_emin
= READ_ONCE(parent
->memory
.emin
);
6033 emin
= min(emin
, parent_emin
);
6034 if (emin
&& parent_emin
) {
6035 unsigned long min_usage
, siblings_min_usage
;
6037 min_usage
= min(usage
, memcg
->memory
.min
);
6038 siblings_min_usage
= atomic_long_read(
6039 &parent
->memory
.children_min_usage
);
6041 if (min_usage
&& siblings_min_usage
)
6042 emin
= min(emin
, parent_emin
* min_usage
/
6043 siblings_min_usage
);
6046 parent_elow
= READ_ONCE(parent
->memory
.elow
);
6047 elow
= min(elow
, parent_elow
);
6048 if (elow
&& parent_elow
) {
6049 unsigned long low_usage
, siblings_low_usage
;
6051 low_usage
= min(usage
, memcg
->memory
.low
);
6052 siblings_low_usage
= atomic_long_read(
6053 &parent
->memory
.children_low_usage
);
6055 if (low_usage
&& siblings_low_usage
)
6056 elow
= min(elow
, parent_elow
* low_usage
/
6057 siblings_low_usage
);
6061 memcg
->memory
.emin
= emin
;
6062 memcg
->memory
.elow
= elow
;
6065 return MEMCG_PROT_MIN
;
6066 else if (usage
<= elow
)
6067 return MEMCG_PROT_LOW
;
6069 return MEMCG_PROT_NONE
;
6073 * mem_cgroup_try_charge - try charging a page
6074 * @page: page to charge
6075 * @mm: mm context of the victim
6076 * @gfp_mask: reclaim mode
6077 * @memcgp: charged memcg return
6078 * @compound: charge the page as compound or small page
6080 * Try to charge @page to the memcg that @mm belongs to, reclaiming
6081 * pages according to @gfp_mask if necessary.
6083 * Returns 0 on success, with *@memcgp pointing to the charged memcg.
6084 * Otherwise, an error code is returned.
6086 * After page->mapping has been set up, the caller must finalize the
6087 * charge with mem_cgroup_commit_charge(). Or abort the transaction
6088 * with mem_cgroup_cancel_charge() in case page instantiation fails.
6090 int mem_cgroup_try_charge(struct page
*page
, struct mm_struct
*mm
,
6091 gfp_t gfp_mask
, struct mem_cgroup
**memcgp
,
6094 struct mem_cgroup
*memcg
= NULL
;
6095 unsigned int nr_pages
= compound
? hpage_nr_pages(page
) : 1;
6098 if (mem_cgroup_disabled())
6101 if (PageSwapCache(page
)) {
6103 * Every swap fault against a single page tries to charge the
6104 * page, bail as early as possible. shmem_unuse() encounters
6105 * already charged pages, too. The USED bit is protected by
6106 * the page lock, which serializes swap cache removal, which
6107 * in turn serializes uncharging.
6109 VM_BUG_ON_PAGE(!PageLocked(page
), page
);
6110 if (compound_head(page
)->mem_cgroup
)
6113 if (do_swap_account
) {
6114 swp_entry_t ent
= { .val
= page_private(page
), };
6115 unsigned short id
= lookup_swap_cgroup_id(ent
);
6118 memcg
= mem_cgroup_from_id(id
);
6119 if (memcg
&& !css_tryget_online(&memcg
->css
))
6126 memcg
= get_mem_cgroup_from_mm(mm
);
6128 ret
= try_charge(memcg
, gfp_mask
, nr_pages
);
6130 css_put(&memcg
->css
);
6136 int mem_cgroup_try_charge_delay(struct page
*page
, struct mm_struct
*mm
,
6137 gfp_t gfp_mask
, struct mem_cgroup
**memcgp
,
6140 struct mem_cgroup
*memcg
;
6143 ret
= mem_cgroup_try_charge(page
, mm
, gfp_mask
, memcgp
, compound
);
6145 mem_cgroup_throttle_swaprate(memcg
, page_to_nid(page
), gfp_mask
);
6150 * mem_cgroup_commit_charge - commit a page charge
6151 * @page: page to charge
6152 * @memcg: memcg to charge the page to
6153 * @lrucare: page might be on LRU already
6154 * @compound: charge the page as compound or small page
6156 * Finalize a charge transaction started by mem_cgroup_try_charge(),
6157 * after page->mapping has been set up. This must happen atomically
6158 * as part of the page instantiation, i.e. under the page table lock
6159 * for anonymous pages, under the page lock for page and swap cache.
6161 * In addition, the page must not be on the LRU during the commit, to
6162 * prevent racing with task migration. If it might be, use @lrucare.
6164 * Use mem_cgroup_cancel_charge() to cancel the transaction instead.
6166 void mem_cgroup_commit_charge(struct page
*page
, struct mem_cgroup
*memcg
,
6167 bool lrucare
, bool compound
)
6169 unsigned int nr_pages
= compound
? hpage_nr_pages(page
) : 1;
6171 VM_BUG_ON_PAGE(!page
->mapping
, page
);
6172 VM_BUG_ON_PAGE(PageLRU(page
) && !lrucare
, page
);
6174 if (mem_cgroup_disabled())
6177 * Swap faults will attempt to charge the same page multiple
6178 * times. But reuse_swap_page() might have removed the page
6179 * from swapcache already, so we can't check PageSwapCache().
6184 commit_charge(page
, memcg
, lrucare
);
6186 local_irq_disable();
6187 mem_cgroup_charge_statistics(memcg
, page
, compound
, nr_pages
);
6188 memcg_check_events(memcg
, page
);
6191 if (do_memsw_account() && PageSwapCache(page
)) {
6192 swp_entry_t entry
= { .val
= page_private(page
) };
6194 * The swap entry might not get freed for a long time,
6195 * let's not wait for it. The page already received a
6196 * memory+swap charge, drop the swap entry duplicate.
6198 mem_cgroup_uncharge_swap(entry
, nr_pages
);
6203 * mem_cgroup_cancel_charge - cancel a page charge
6204 * @page: page to charge
6205 * @memcg: memcg to charge the page to
6206 * @compound: charge the page as compound or small page
6208 * Cancel a charge transaction started by mem_cgroup_try_charge().
6210 void mem_cgroup_cancel_charge(struct page
*page
, struct mem_cgroup
*memcg
,
6213 unsigned int nr_pages
= compound
? hpage_nr_pages(page
) : 1;
6215 if (mem_cgroup_disabled())
6218 * Swap faults will attempt to charge the same page multiple
6219 * times. But reuse_swap_page() might have removed the page
6220 * from swapcache already, so we can't check PageSwapCache().
6225 cancel_charge(memcg
, nr_pages
);
6228 struct uncharge_gather
{
6229 struct mem_cgroup
*memcg
;
6230 unsigned long pgpgout
;
6231 unsigned long nr_anon
;
6232 unsigned long nr_file
;
6233 unsigned long nr_kmem
;
6234 unsigned long nr_huge
;
6235 unsigned long nr_shmem
;
6236 struct page
*dummy_page
;
6239 static inline void uncharge_gather_clear(struct uncharge_gather
*ug
)
6241 memset(ug
, 0, sizeof(*ug
));
6244 static void uncharge_batch(const struct uncharge_gather
*ug
)
6246 unsigned long nr_pages
= ug
->nr_anon
+ ug
->nr_file
+ ug
->nr_kmem
;
6247 unsigned long flags
;
6249 if (!mem_cgroup_is_root(ug
->memcg
)) {
6250 page_counter_uncharge(&ug
->memcg
->memory
, nr_pages
);
6251 if (do_memsw_account())
6252 page_counter_uncharge(&ug
->memcg
->memsw
, nr_pages
);
6253 if (!cgroup_subsys_on_dfl(memory_cgrp_subsys
) && ug
->nr_kmem
)
6254 page_counter_uncharge(&ug
->memcg
->kmem
, ug
->nr_kmem
);
6255 memcg_oom_recover(ug
->memcg
);
6258 local_irq_save(flags
);
6259 __mod_memcg_state(ug
->memcg
, MEMCG_RSS
, -ug
->nr_anon
);
6260 __mod_memcg_state(ug
->memcg
, MEMCG_CACHE
, -ug
->nr_file
);
6261 __mod_memcg_state(ug
->memcg
, MEMCG_RSS_HUGE
, -ug
->nr_huge
);
6262 __mod_memcg_state(ug
->memcg
, NR_SHMEM
, -ug
->nr_shmem
);
6263 __count_memcg_events(ug
->memcg
, PGPGOUT
, ug
->pgpgout
);
6264 __this_cpu_add(ug
->memcg
->vmstats_percpu
->nr_page_events
, nr_pages
);
6265 memcg_check_events(ug
->memcg
, ug
->dummy_page
);
6266 local_irq_restore(flags
);
6268 if (!mem_cgroup_is_root(ug
->memcg
))
6269 css_put_many(&ug
->memcg
->css
, nr_pages
);
6272 static void uncharge_page(struct page
*page
, struct uncharge_gather
*ug
)
6274 VM_BUG_ON_PAGE(PageLRU(page
), page
);
6275 VM_BUG_ON_PAGE(page_count(page
) && !is_zone_device_page(page
) &&
6276 !PageHWPoison(page
) , page
);
6278 if (!page
->mem_cgroup
)
6282 * Nobody should be changing or seriously looking at
6283 * page->mem_cgroup at this point, we have fully
6284 * exclusive access to the page.
6287 if (ug
->memcg
!= page
->mem_cgroup
) {
6290 uncharge_gather_clear(ug
);
6292 ug
->memcg
= page
->mem_cgroup
;
6295 if (!PageKmemcg(page
)) {
6296 unsigned int nr_pages
= 1;
6298 if (PageTransHuge(page
)) {
6299 nr_pages
<<= compound_order(page
);
6300 ug
->nr_huge
+= nr_pages
;
6303 ug
->nr_anon
+= nr_pages
;
6305 ug
->nr_file
+= nr_pages
;
6306 if (PageSwapBacked(page
))
6307 ug
->nr_shmem
+= nr_pages
;
6311 ug
->nr_kmem
+= 1 << compound_order(page
);
6312 __ClearPageKmemcg(page
);
6315 ug
->dummy_page
= page
;
6316 page
->mem_cgroup
= NULL
;
6319 static void uncharge_list(struct list_head
*page_list
)
6321 struct uncharge_gather ug
;
6322 struct list_head
*next
;
6324 uncharge_gather_clear(&ug
);
6327 * Note that the list can be a single page->lru; hence the
6328 * do-while loop instead of a simple list_for_each_entry().
6330 next
= page_list
->next
;
6334 page
= list_entry(next
, struct page
, lru
);
6335 next
= page
->lru
.next
;
6337 uncharge_page(page
, &ug
);
6338 } while (next
!= page_list
);
6341 uncharge_batch(&ug
);
6345 * mem_cgroup_uncharge - uncharge a page
6346 * @page: page to uncharge
6348 * Uncharge a page previously charged with mem_cgroup_try_charge() and
6349 * mem_cgroup_commit_charge().
6351 void mem_cgroup_uncharge(struct page
*page
)
6353 struct uncharge_gather ug
;
6355 if (mem_cgroup_disabled())
6358 /* Don't touch page->lru of any random page, pre-check: */
6359 if (!page
->mem_cgroup
)
6362 uncharge_gather_clear(&ug
);
6363 uncharge_page(page
, &ug
);
6364 uncharge_batch(&ug
);
6368 * mem_cgroup_uncharge_list - uncharge a list of page
6369 * @page_list: list of pages to uncharge
6371 * Uncharge a list of pages previously charged with
6372 * mem_cgroup_try_charge() and mem_cgroup_commit_charge().
6374 void mem_cgroup_uncharge_list(struct list_head
*page_list
)
6376 if (mem_cgroup_disabled())
6379 if (!list_empty(page_list
))
6380 uncharge_list(page_list
);
6384 * mem_cgroup_migrate - charge a page's replacement
6385 * @oldpage: currently circulating page
6386 * @newpage: replacement page
6388 * Charge @newpage as a replacement page for @oldpage. @oldpage will
6389 * be uncharged upon free.
6391 * Both pages must be locked, @newpage->mapping must be set up.
6393 void mem_cgroup_migrate(struct page
*oldpage
, struct page
*newpage
)
6395 struct mem_cgroup
*memcg
;
6396 unsigned int nr_pages
;
6398 unsigned long flags
;
6400 VM_BUG_ON_PAGE(!PageLocked(oldpage
), oldpage
);
6401 VM_BUG_ON_PAGE(!PageLocked(newpage
), newpage
);
6402 VM_BUG_ON_PAGE(PageAnon(oldpage
) != PageAnon(newpage
), newpage
);
6403 VM_BUG_ON_PAGE(PageTransHuge(oldpage
) != PageTransHuge(newpage
),
6406 if (mem_cgroup_disabled())
6409 /* Page cache replacement: new page already charged? */
6410 if (newpage
->mem_cgroup
)
6413 /* Swapcache readahead pages can get replaced before being charged */
6414 memcg
= oldpage
->mem_cgroup
;
6418 /* Force-charge the new page. The old one will be freed soon */
6419 compound
= PageTransHuge(newpage
);
6420 nr_pages
= compound
? hpage_nr_pages(newpage
) : 1;
6422 page_counter_charge(&memcg
->memory
, nr_pages
);
6423 if (do_memsw_account())
6424 page_counter_charge(&memcg
->memsw
, nr_pages
);
6425 css_get_many(&memcg
->css
, nr_pages
);
6427 commit_charge(newpage
, memcg
, false);
6429 local_irq_save(flags
);
6430 mem_cgroup_charge_statistics(memcg
, newpage
, compound
, nr_pages
);
6431 memcg_check_events(memcg
, newpage
);
6432 local_irq_restore(flags
);
6435 DEFINE_STATIC_KEY_FALSE(memcg_sockets_enabled_key
);
6436 EXPORT_SYMBOL(memcg_sockets_enabled_key
);
6438 void mem_cgroup_sk_alloc(struct sock
*sk
)
6440 struct mem_cgroup
*memcg
;
6442 if (!mem_cgroup_sockets_enabled
)
6446 * Socket cloning can throw us here with sk_memcg already
6447 * filled. It won't however, necessarily happen from
6448 * process context. So the test for root memcg given
6449 * the current task's memcg won't help us in this case.
6451 * Respecting the original socket's memcg is a better
6452 * decision in this case.
6455 css_get(&sk
->sk_memcg
->css
);
6460 memcg
= mem_cgroup_from_task(current
);
6461 if (memcg
== root_mem_cgroup
)
6463 if (!cgroup_subsys_on_dfl(memory_cgrp_subsys
) && !memcg
->tcpmem_active
)
6465 if (css_tryget_online(&memcg
->css
))
6466 sk
->sk_memcg
= memcg
;
6471 void mem_cgroup_sk_free(struct sock
*sk
)
6474 css_put(&sk
->sk_memcg
->css
);
6478 * mem_cgroup_charge_skmem - charge socket memory
6479 * @memcg: memcg to charge
6480 * @nr_pages: number of pages to charge
6482 * Charges @nr_pages to @memcg. Returns %true if the charge fit within
6483 * @memcg's configured limit, %false if the charge had to be forced.
6485 bool mem_cgroup_charge_skmem(struct mem_cgroup
*memcg
, unsigned int nr_pages
)
6487 gfp_t gfp_mask
= GFP_KERNEL
;
6489 if (!cgroup_subsys_on_dfl(memory_cgrp_subsys
)) {
6490 struct page_counter
*fail
;
6492 if (page_counter_try_charge(&memcg
->tcpmem
, nr_pages
, &fail
)) {
6493 memcg
->tcpmem_pressure
= 0;
6496 page_counter_charge(&memcg
->tcpmem
, nr_pages
);
6497 memcg
->tcpmem_pressure
= 1;
6501 /* Don't block in the packet receive path */
6503 gfp_mask
= GFP_NOWAIT
;
6505 mod_memcg_state(memcg
, MEMCG_SOCK
, nr_pages
);
6507 if (try_charge(memcg
, gfp_mask
, nr_pages
) == 0)
6510 try_charge(memcg
, gfp_mask
|__GFP_NOFAIL
, nr_pages
);
6515 * mem_cgroup_uncharge_skmem - uncharge socket memory
6516 * @memcg: memcg to uncharge
6517 * @nr_pages: number of pages to uncharge
6519 void mem_cgroup_uncharge_skmem(struct mem_cgroup
*memcg
, unsigned int nr_pages
)
6521 if (!cgroup_subsys_on_dfl(memory_cgrp_subsys
)) {
6522 page_counter_uncharge(&memcg
->tcpmem
, nr_pages
);
6526 mod_memcg_state(memcg
, MEMCG_SOCK
, -nr_pages
);
6528 refill_stock(memcg
, nr_pages
);
6531 static int __init
cgroup_memory(char *s
)
6535 while ((token
= strsep(&s
, ",")) != NULL
) {
6538 if (!strcmp(token
, "nosocket"))
6539 cgroup_memory_nosocket
= true;
6540 if (!strcmp(token
, "nokmem"))
6541 cgroup_memory_nokmem
= true;
6545 __setup("cgroup.memory=", cgroup_memory
);
6548 * subsys_initcall() for memory controller.
6550 * Some parts like memcg_hotplug_cpu_dead() have to be initialized from this
6551 * context because of lock dependencies (cgroup_lock -> cpu hotplug) but
6552 * basically everything that doesn't depend on a specific mem_cgroup structure
6553 * should be initialized from here.
6555 static int __init
mem_cgroup_init(void)
6559 #ifdef CONFIG_MEMCG_KMEM
6561 * Kmem cache creation is mostly done with the slab_mutex held,
6562 * so use a workqueue with limited concurrency to avoid stalling
6563 * all worker threads in case lots of cgroups are created and
6564 * destroyed simultaneously.
6566 memcg_kmem_cache_wq
= alloc_workqueue("memcg_kmem_cache", 0, 1);
6567 BUG_ON(!memcg_kmem_cache_wq
);
6570 cpuhp_setup_state_nocalls(CPUHP_MM_MEMCQ_DEAD
, "mm/memctrl:dead", NULL
,
6571 memcg_hotplug_cpu_dead
);
6573 for_each_possible_cpu(cpu
)
6574 INIT_WORK(&per_cpu_ptr(&memcg_stock
, cpu
)->work
,
6577 for_each_node(node
) {
6578 struct mem_cgroup_tree_per_node
*rtpn
;
6580 rtpn
= kzalloc_node(sizeof(*rtpn
), GFP_KERNEL
,
6581 node_online(node
) ? node
: NUMA_NO_NODE
);
6583 rtpn
->rb_root
= RB_ROOT
;
6584 rtpn
->rb_rightmost
= NULL
;
6585 spin_lock_init(&rtpn
->lock
);
6586 soft_limit_tree
.rb_tree_per_node
[node
] = rtpn
;
6591 subsys_initcall(mem_cgroup_init
);
6593 #ifdef CONFIG_MEMCG_SWAP
6594 static struct mem_cgroup
*mem_cgroup_id_get_online(struct mem_cgroup
*memcg
)
6596 while (!refcount_inc_not_zero(&memcg
->id
.ref
)) {
6598 * The root cgroup cannot be destroyed, so it's refcount must
6601 if (WARN_ON_ONCE(memcg
== root_mem_cgroup
)) {
6605 memcg
= parent_mem_cgroup(memcg
);
6607 memcg
= root_mem_cgroup
;
6613 * mem_cgroup_swapout - transfer a memsw charge to swap
6614 * @page: page whose memsw charge to transfer
6615 * @entry: swap entry to move the charge to
6617 * Transfer the memsw charge of @page to @entry.
6619 void mem_cgroup_swapout(struct page
*page
, swp_entry_t entry
)
6621 struct mem_cgroup
*memcg
, *swap_memcg
;
6622 unsigned int nr_entries
;
6623 unsigned short oldid
;
6625 VM_BUG_ON_PAGE(PageLRU(page
), page
);
6626 VM_BUG_ON_PAGE(page_count(page
), page
);
6628 if (!do_memsw_account())
6631 memcg
= page
->mem_cgroup
;
6633 /* Readahead page, never charged */
6638 * In case the memcg owning these pages has been offlined and doesn't
6639 * have an ID allocated to it anymore, charge the closest online
6640 * ancestor for the swap instead and transfer the memory+swap charge.
6642 swap_memcg
= mem_cgroup_id_get_online(memcg
);
6643 nr_entries
= hpage_nr_pages(page
);
6644 /* Get references for the tail pages, too */
6646 mem_cgroup_id_get_many(swap_memcg
, nr_entries
- 1);
6647 oldid
= swap_cgroup_record(entry
, mem_cgroup_id(swap_memcg
),
6649 VM_BUG_ON_PAGE(oldid
, page
);
6650 mod_memcg_state(swap_memcg
, MEMCG_SWAP
, nr_entries
);
6652 page
->mem_cgroup
= NULL
;
6654 if (!mem_cgroup_is_root(memcg
))
6655 page_counter_uncharge(&memcg
->memory
, nr_entries
);
6657 if (memcg
!= swap_memcg
) {
6658 if (!mem_cgroup_is_root(swap_memcg
))
6659 page_counter_charge(&swap_memcg
->memsw
, nr_entries
);
6660 page_counter_uncharge(&memcg
->memsw
, nr_entries
);
6664 * Interrupts should be disabled here because the caller holds the
6665 * i_pages lock which is taken with interrupts-off. It is
6666 * important here to have the interrupts disabled because it is the
6667 * only synchronisation we have for updating the per-CPU variables.
6669 VM_BUG_ON(!irqs_disabled());
6670 mem_cgroup_charge_statistics(memcg
, page
, PageTransHuge(page
),
6672 memcg_check_events(memcg
, page
);
6674 if (!mem_cgroup_is_root(memcg
))
6675 css_put_many(&memcg
->css
, nr_entries
);
6679 * mem_cgroup_try_charge_swap - try charging swap space for a page
6680 * @page: page being added to swap
6681 * @entry: swap entry to charge
6683 * Try to charge @page's memcg for the swap space at @entry.
6685 * Returns 0 on success, -ENOMEM on failure.
6687 int mem_cgroup_try_charge_swap(struct page
*page
, swp_entry_t entry
)
6689 unsigned int nr_pages
= hpage_nr_pages(page
);
6690 struct page_counter
*counter
;
6691 struct mem_cgroup
*memcg
;
6692 unsigned short oldid
;
6694 if (!cgroup_subsys_on_dfl(memory_cgrp_subsys
) || !do_swap_account
)
6697 memcg
= page
->mem_cgroup
;
6699 /* Readahead page, never charged */
6704 memcg_memory_event(memcg
, MEMCG_SWAP_FAIL
);
6708 memcg
= mem_cgroup_id_get_online(memcg
);
6710 if (!mem_cgroup_is_root(memcg
) &&
6711 !page_counter_try_charge(&memcg
->swap
, nr_pages
, &counter
)) {
6712 memcg_memory_event(memcg
, MEMCG_SWAP_MAX
);
6713 memcg_memory_event(memcg
, MEMCG_SWAP_FAIL
);
6714 mem_cgroup_id_put(memcg
);
6718 /* Get references for the tail pages, too */
6720 mem_cgroup_id_get_many(memcg
, nr_pages
- 1);
6721 oldid
= swap_cgroup_record(entry
, mem_cgroup_id(memcg
), nr_pages
);
6722 VM_BUG_ON_PAGE(oldid
, page
);
6723 mod_memcg_state(memcg
, MEMCG_SWAP
, nr_pages
);
6729 * mem_cgroup_uncharge_swap - uncharge swap space
6730 * @entry: swap entry to uncharge
6731 * @nr_pages: the amount of swap space to uncharge
6733 void mem_cgroup_uncharge_swap(swp_entry_t entry
, unsigned int nr_pages
)
6735 struct mem_cgroup
*memcg
;
6738 if (!do_swap_account
)
6741 id
= swap_cgroup_record(entry
, 0, nr_pages
);
6743 memcg
= mem_cgroup_from_id(id
);
6745 if (!mem_cgroup_is_root(memcg
)) {
6746 if (cgroup_subsys_on_dfl(memory_cgrp_subsys
))
6747 page_counter_uncharge(&memcg
->swap
, nr_pages
);
6749 page_counter_uncharge(&memcg
->memsw
, nr_pages
);
6751 mod_memcg_state(memcg
, MEMCG_SWAP
, -nr_pages
);
6752 mem_cgroup_id_put_many(memcg
, nr_pages
);
6757 long mem_cgroup_get_nr_swap_pages(struct mem_cgroup
*memcg
)
6759 long nr_swap_pages
= get_nr_swap_pages();
6761 if (!do_swap_account
|| !cgroup_subsys_on_dfl(memory_cgrp_subsys
))
6762 return nr_swap_pages
;
6763 for (; memcg
!= root_mem_cgroup
; memcg
= parent_mem_cgroup(memcg
))
6764 nr_swap_pages
= min_t(long, nr_swap_pages
,
6765 READ_ONCE(memcg
->swap
.max
) -
6766 page_counter_read(&memcg
->swap
));
6767 return nr_swap_pages
;
6770 bool mem_cgroup_swap_full(struct page
*page
)
6772 struct mem_cgroup
*memcg
;
6774 VM_BUG_ON_PAGE(!PageLocked(page
), page
);
6778 if (!do_swap_account
|| !cgroup_subsys_on_dfl(memory_cgrp_subsys
))
6781 memcg
= page
->mem_cgroup
;
6785 for (; memcg
!= root_mem_cgroup
; memcg
= parent_mem_cgroup(memcg
))
6786 if (page_counter_read(&memcg
->swap
) * 2 >= memcg
->swap
.max
)
6792 /* for remember boot option*/
6793 #ifdef CONFIG_MEMCG_SWAP_ENABLED
6794 static int really_do_swap_account __initdata
= 1;
6796 static int really_do_swap_account __initdata
;
6799 static int __init
enable_swap_account(char *s
)
6801 if (!strcmp(s
, "1"))
6802 really_do_swap_account
= 1;
6803 else if (!strcmp(s
, "0"))
6804 really_do_swap_account
= 0;
6807 __setup("swapaccount=", enable_swap_account
);
6809 static u64
swap_current_read(struct cgroup_subsys_state
*css
,
6812 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
6814 return (u64
)page_counter_read(&memcg
->swap
) * PAGE_SIZE
;
6817 static int swap_max_show(struct seq_file
*m
, void *v
)
6819 return seq_puts_memcg_tunable(m
,
6820 READ_ONCE(mem_cgroup_from_seq(m
)->swap
.max
));
6823 static ssize_t
swap_max_write(struct kernfs_open_file
*of
,
6824 char *buf
, size_t nbytes
, loff_t off
)
6826 struct mem_cgroup
*memcg
= mem_cgroup_from_css(of_css(of
));
6830 buf
= strstrip(buf
);
6831 err
= page_counter_memparse(buf
, "max", &max
);
6835 xchg(&memcg
->swap
.max
, max
);
6840 static int swap_events_show(struct seq_file
*m
, void *v
)
6842 struct mem_cgroup
*memcg
= mem_cgroup_from_seq(m
);
6844 seq_printf(m
, "max %lu\n",
6845 atomic_long_read(&memcg
->memory_events
[MEMCG_SWAP_MAX
]));
6846 seq_printf(m
, "fail %lu\n",
6847 atomic_long_read(&memcg
->memory_events
[MEMCG_SWAP_FAIL
]));
6852 static struct cftype swap_files
[] = {
6854 .name
= "swap.current",
6855 .flags
= CFTYPE_NOT_ON_ROOT
,
6856 .read_u64
= swap_current_read
,
6860 .flags
= CFTYPE_NOT_ON_ROOT
,
6861 .seq_show
= swap_max_show
,
6862 .write
= swap_max_write
,
6865 .name
= "swap.events",
6866 .flags
= CFTYPE_NOT_ON_ROOT
,
6867 .file_offset
= offsetof(struct mem_cgroup
, swap_events_file
),
6868 .seq_show
= swap_events_show
,
6873 static struct cftype memsw_cgroup_files
[] = {
6875 .name
= "memsw.usage_in_bytes",
6876 .private = MEMFILE_PRIVATE(_MEMSWAP
, RES_USAGE
),
6877 .read_u64
= mem_cgroup_read_u64
,
6880 .name
= "memsw.max_usage_in_bytes",
6881 .private = MEMFILE_PRIVATE(_MEMSWAP
, RES_MAX_USAGE
),
6882 .write
= mem_cgroup_reset
,
6883 .read_u64
= mem_cgroup_read_u64
,
6886 .name
= "memsw.limit_in_bytes",
6887 .private = MEMFILE_PRIVATE(_MEMSWAP
, RES_LIMIT
),
6888 .write
= mem_cgroup_write
,
6889 .read_u64
= mem_cgroup_read_u64
,
6892 .name
= "memsw.failcnt",
6893 .private = MEMFILE_PRIVATE(_MEMSWAP
, RES_FAILCNT
),
6894 .write
= mem_cgroup_reset
,
6895 .read_u64
= mem_cgroup_read_u64
,
6897 { }, /* terminate */
6900 static int __init
mem_cgroup_swap_init(void)
6902 if (!mem_cgroup_disabled() && really_do_swap_account
) {
6903 do_swap_account
= 1;
6904 WARN_ON(cgroup_add_dfl_cftypes(&memory_cgrp_subsys
,
6906 WARN_ON(cgroup_add_legacy_cftypes(&memory_cgrp_subsys
,
6907 memsw_cgroup_files
));
6911 subsys_initcall(mem_cgroup_swap_init
);
6913 #endif /* CONFIG_MEMCG_SWAP */