1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /* memcontrol.c - Memory Controller
4 * Copyright IBM Corporation, 2007
5 * Author Balbir Singh <balbir@linux.vnet.ibm.com>
7 * Copyright 2007 OpenVZ SWsoft Inc
8 * Author: Pavel Emelianov <xemul@openvz.org>
11 * Copyright (C) 2009 Nokia Corporation
12 * Author: Kirill A. Shutemov
14 * Kernel Memory Controller
15 * Copyright (C) 2012 Parallels Inc. and Google Inc.
16 * Authors: Glauber Costa and Suleiman Souhlal
19 * Charge lifetime sanitation
20 * Lockless page tracking & accounting
21 * Unified hierarchy configuration model
22 * Copyright (C) 2015 Red Hat, Inc., Johannes Weiner
25 #include <linux/page_counter.h>
26 #include <linux/memcontrol.h>
27 #include <linux/cgroup.h>
28 #include <linux/pagewalk.h>
29 #include <linux/sched/mm.h>
30 #include <linux/shmem_fs.h>
31 #include <linux/hugetlb.h>
32 #include <linux/pagemap.h>
33 #include <linux/vm_event_item.h>
34 #include <linux/smp.h>
35 #include <linux/page-flags.h>
36 #include <linux/backing-dev.h>
37 #include <linux/bit_spinlock.h>
38 #include <linux/rcupdate.h>
39 #include <linux/limits.h>
40 #include <linux/export.h>
41 #include <linux/mutex.h>
42 #include <linux/rbtree.h>
43 #include <linux/slab.h>
44 #include <linux/swap.h>
45 #include <linux/swapops.h>
46 #include <linux/spinlock.h>
47 #include <linux/eventfd.h>
48 #include <linux/poll.h>
49 #include <linux/sort.h>
51 #include <linux/seq_file.h>
52 #include <linux/vmpressure.h>
53 #include <linux/mm_inline.h>
54 #include <linux/swap_cgroup.h>
55 #include <linux/cpu.h>
56 #include <linux/oom.h>
57 #include <linux/lockdep.h>
58 #include <linux/file.h>
59 #include <linux/tracehook.h>
60 #include <linux/psi.h>
61 #include <linux/seq_buf.h>
67 #include <linux/uaccess.h>
69 #include <trace/events/vmscan.h>
71 struct cgroup_subsys memory_cgrp_subsys __read_mostly
;
72 EXPORT_SYMBOL(memory_cgrp_subsys
);
74 struct mem_cgroup
*root_mem_cgroup __read_mostly
;
76 #define MEM_CGROUP_RECLAIM_RETRIES 5
78 /* Socket memory accounting disabled? */
79 static bool cgroup_memory_nosocket
;
81 /* Kernel memory accounting disabled? */
82 static bool cgroup_memory_nokmem
;
84 /* Whether the swap controller is active */
85 #ifdef CONFIG_MEMCG_SWAP
86 int do_swap_account __read_mostly
;
88 #define do_swap_account 0
91 #ifdef CONFIG_CGROUP_WRITEBACK
92 static DECLARE_WAIT_QUEUE_HEAD(memcg_cgwb_frn_waitq
);
95 /* Whether legacy memory+swap accounting is active */
96 static bool do_memsw_account(void)
98 return !cgroup_subsys_on_dfl(memory_cgrp_subsys
) && do_swap_account
;
101 static const char *const mem_cgroup_lru_names
[] = {
109 #define THRESHOLDS_EVENTS_TARGET 128
110 #define SOFTLIMIT_EVENTS_TARGET 1024
111 #define NUMAINFO_EVENTS_TARGET 1024
114 * Cgroups above their limits are maintained in a RB-Tree, independent of
115 * their hierarchy representation
118 struct mem_cgroup_tree_per_node
{
119 struct rb_root rb_root
;
120 struct rb_node
*rb_rightmost
;
124 struct mem_cgroup_tree
{
125 struct mem_cgroup_tree_per_node
*rb_tree_per_node
[MAX_NUMNODES
];
128 static struct mem_cgroup_tree soft_limit_tree __read_mostly
;
131 struct mem_cgroup_eventfd_list
{
132 struct list_head list
;
133 struct eventfd_ctx
*eventfd
;
137 * cgroup_event represents events which userspace want to receive.
139 struct mem_cgroup_event
{
141 * memcg which the event belongs to.
143 struct mem_cgroup
*memcg
;
145 * eventfd to signal userspace about the event.
147 struct eventfd_ctx
*eventfd
;
149 * Each of these stored in a list by the cgroup.
151 struct list_head list
;
153 * register_event() callback will be used to add new userspace
154 * waiter for changes related to this event. Use eventfd_signal()
155 * on eventfd to send notification to userspace.
157 int (*register_event
)(struct mem_cgroup
*memcg
,
158 struct eventfd_ctx
*eventfd
, const char *args
);
160 * unregister_event() callback will be called when userspace closes
161 * the eventfd or on cgroup removing. This callback must be set,
162 * if you want provide notification functionality.
164 void (*unregister_event
)(struct mem_cgroup
*memcg
,
165 struct eventfd_ctx
*eventfd
);
167 * All fields below needed to unregister event when
168 * userspace closes eventfd.
171 wait_queue_head_t
*wqh
;
172 wait_queue_entry_t wait
;
173 struct work_struct remove
;
176 static void mem_cgroup_threshold(struct mem_cgroup
*memcg
);
177 static void mem_cgroup_oom_notify(struct mem_cgroup
*memcg
);
179 /* Stuffs for move charges at task migration. */
181 * Types of charges to be moved.
183 #define MOVE_ANON 0x1U
184 #define MOVE_FILE 0x2U
185 #define MOVE_MASK (MOVE_ANON | MOVE_FILE)
187 /* "mc" and its members are protected by cgroup_mutex */
188 static struct move_charge_struct
{
189 spinlock_t lock
; /* for from, to */
190 struct mm_struct
*mm
;
191 struct mem_cgroup
*from
;
192 struct mem_cgroup
*to
;
194 unsigned long precharge
;
195 unsigned long moved_charge
;
196 unsigned long moved_swap
;
197 struct task_struct
*moving_task
; /* a task moving charges */
198 wait_queue_head_t waitq
; /* a waitq for other context */
200 .lock
= __SPIN_LOCK_UNLOCKED(mc
.lock
),
201 .waitq
= __WAIT_QUEUE_HEAD_INITIALIZER(mc
.waitq
),
205 * Maximum loops in mem_cgroup_hierarchical_reclaim(), used for soft
206 * limit reclaim to prevent infinite loops, if they ever occur.
208 #define MEM_CGROUP_MAX_RECLAIM_LOOPS 100
209 #define MEM_CGROUP_MAX_SOFT_LIMIT_RECLAIM_LOOPS 2
212 MEM_CGROUP_CHARGE_TYPE_CACHE
= 0,
213 MEM_CGROUP_CHARGE_TYPE_ANON
,
214 MEM_CGROUP_CHARGE_TYPE_SWAPOUT
, /* for accounting swapcache */
215 MEM_CGROUP_CHARGE_TYPE_DROP
, /* a page was unused swap cache */
219 /* for encoding cft->private value on file */
228 #define MEMFILE_PRIVATE(x, val) ((x) << 16 | (val))
229 #define MEMFILE_TYPE(val) ((val) >> 16 & 0xffff)
230 #define MEMFILE_ATTR(val) ((val) & 0xffff)
231 /* Used for OOM nofiier */
232 #define OOM_CONTROL (0)
235 * Iteration constructs for visiting all cgroups (under a tree). If
236 * loops are exited prematurely (break), mem_cgroup_iter_break() must
237 * be used for reference counting.
239 #define for_each_mem_cgroup_tree(iter, root) \
240 for (iter = mem_cgroup_iter(root, NULL, NULL); \
242 iter = mem_cgroup_iter(root, iter, NULL))
244 #define for_each_mem_cgroup(iter) \
245 for (iter = mem_cgroup_iter(NULL, NULL, NULL); \
247 iter = mem_cgroup_iter(NULL, iter, NULL))
249 static inline bool should_force_charge(void)
251 return tsk_is_oom_victim(current
) || fatal_signal_pending(current
) ||
252 (current
->flags
& PF_EXITING
);
255 /* Some nice accessors for the vmpressure. */
256 struct vmpressure
*memcg_to_vmpressure(struct mem_cgroup
*memcg
)
259 memcg
= root_mem_cgroup
;
260 return &memcg
->vmpressure
;
263 struct cgroup_subsys_state
*vmpressure_to_css(struct vmpressure
*vmpr
)
265 return &container_of(vmpr
, struct mem_cgroup
, vmpressure
)->css
;
268 #ifdef CONFIG_MEMCG_KMEM
270 * This will be the memcg's index in each cache's ->memcg_params.memcg_caches.
271 * The main reason for not using cgroup id for this:
272 * this works better in sparse environments, where we have a lot of memcgs,
273 * but only a few kmem-limited. Or also, if we have, for instance, 200
274 * memcgs, and none but the 200th is kmem-limited, we'd have to have a
275 * 200 entry array for that.
277 * The current size of the caches array is stored in memcg_nr_cache_ids. It
278 * will double each time we have to increase it.
280 static DEFINE_IDA(memcg_cache_ida
);
281 int memcg_nr_cache_ids
;
283 /* Protects memcg_nr_cache_ids */
284 static DECLARE_RWSEM(memcg_cache_ids_sem
);
286 void memcg_get_cache_ids(void)
288 down_read(&memcg_cache_ids_sem
);
291 void memcg_put_cache_ids(void)
293 up_read(&memcg_cache_ids_sem
);
297 * MIN_SIZE is different than 1, because we would like to avoid going through
298 * the alloc/free process all the time. In a small machine, 4 kmem-limited
299 * cgroups is a reasonable guess. In the future, it could be a parameter or
300 * tunable, but that is strictly not necessary.
302 * MAX_SIZE should be as large as the number of cgrp_ids. Ideally, we could get
303 * this constant directly from cgroup, but it is understandable that this is
304 * better kept as an internal representation in cgroup.c. In any case, the
305 * cgrp_id space is not getting any smaller, and we don't have to necessarily
306 * increase ours as well if it increases.
308 #define MEMCG_CACHES_MIN_SIZE 4
309 #define MEMCG_CACHES_MAX_SIZE MEM_CGROUP_ID_MAX
312 * A lot of the calls to the cache allocation functions are expected to be
313 * inlined by the compiler. Since the calls to memcg_kmem_get_cache are
314 * conditional to this static branch, we'll have to allow modules that does
315 * kmem_cache_alloc and the such to see this symbol as well
317 DEFINE_STATIC_KEY_FALSE(memcg_kmem_enabled_key
);
318 EXPORT_SYMBOL(memcg_kmem_enabled_key
);
320 struct workqueue_struct
*memcg_kmem_cache_wq
;
323 static int memcg_shrinker_map_size
;
324 static DEFINE_MUTEX(memcg_shrinker_map_mutex
);
326 static void memcg_free_shrinker_map_rcu(struct rcu_head
*head
)
328 kvfree(container_of(head
, struct memcg_shrinker_map
, rcu
));
331 static int memcg_expand_one_shrinker_map(struct mem_cgroup
*memcg
,
332 int size
, int old_size
)
334 struct memcg_shrinker_map
*new, *old
;
337 lockdep_assert_held(&memcg_shrinker_map_mutex
);
340 old
= rcu_dereference_protected(
341 mem_cgroup_nodeinfo(memcg
, nid
)->shrinker_map
, true);
342 /* Not yet online memcg */
346 new = kvmalloc(sizeof(*new) + size
, GFP_KERNEL
);
350 /* Set all old bits, clear all new bits */
351 memset(new->map
, (int)0xff, old_size
);
352 memset((void *)new->map
+ old_size
, 0, size
- old_size
);
354 rcu_assign_pointer(memcg
->nodeinfo
[nid
]->shrinker_map
, new);
355 call_rcu(&old
->rcu
, memcg_free_shrinker_map_rcu
);
361 static void memcg_free_shrinker_maps(struct mem_cgroup
*memcg
)
363 struct mem_cgroup_per_node
*pn
;
364 struct memcg_shrinker_map
*map
;
367 if (mem_cgroup_is_root(memcg
))
371 pn
= mem_cgroup_nodeinfo(memcg
, nid
);
372 map
= rcu_dereference_protected(pn
->shrinker_map
, true);
375 rcu_assign_pointer(pn
->shrinker_map
, NULL
);
379 static int memcg_alloc_shrinker_maps(struct mem_cgroup
*memcg
)
381 struct memcg_shrinker_map
*map
;
382 int nid
, size
, ret
= 0;
384 if (mem_cgroup_is_root(memcg
))
387 mutex_lock(&memcg_shrinker_map_mutex
);
388 size
= memcg_shrinker_map_size
;
390 map
= kvzalloc(sizeof(*map
) + size
, GFP_KERNEL
);
392 memcg_free_shrinker_maps(memcg
);
396 rcu_assign_pointer(memcg
->nodeinfo
[nid
]->shrinker_map
, map
);
398 mutex_unlock(&memcg_shrinker_map_mutex
);
403 int memcg_expand_shrinker_maps(int new_id
)
405 int size
, old_size
, ret
= 0;
406 struct mem_cgroup
*memcg
;
408 size
= DIV_ROUND_UP(new_id
+ 1, BITS_PER_LONG
) * sizeof(unsigned long);
409 old_size
= memcg_shrinker_map_size
;
410 if (size
<= old_size
)
413 mutex_lock(&memcg_shrinker_map_mutex
);
414 if (!root_mem_cgroup
)
417 for_each_mem_cgroup(memcg
) {
418 if (mem_cgroup_is_root(memcg
))
420 ret
= memcg_expand_one_shrinker_map(memcg
, size
, old_size
);
422 mem_cgroup_iter_break(NULL
, memcg
);
428 memcg_shrinker_map_size
= size
;
429 mutex_unlock(&memcg_shrinker_map_mutex
);
433 void memcg_set_shrinker_bit(struct mem_cgroup
*memcg
, int nid
, int shrinker_id
)
435 if (shrinker_id
>= 0 && memcg
&& !mem_cgroup_is_root(memcg
)) {
436 struct memcg_shrinker_map
*map
;
439 map
= rcu_dereference(memcg
->nodeinfo
[nid
]->shrinker_map
);
440 /* Pairs with smp mb in shrink_slab() */
441 smp_mb__before_atomic();
442 set_bit(shrinker_id
, map
->map
);
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 (PageSlab(page
) && !PageTail(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
);
756 __this_cpu_add(pn
->lruvec_stat_local
->count
[idx
], val
);
758 x
= val
+ __this_cpu_read(pn
->lruvec_stat_cpu
->count
[idx
]);
759 if (unlikely(abs(x
) > MEMCG_CHARGE_BATCH
)) {
760 struct mem_cgroup_per_node
*pi
;
762 for (pi
= pn
; pi
; pi
= parent_nodeinfo(pi
, pgdat
->node_id
))
763 atomic_long_add(x
, &pi
->lruvec_stat
[idx
]);
766 __this_cpu_write(pn
->lruvec_stat_cpu
->count
[idx
], x
);
769 void __mod_lruvec_slab_state(void *p
, enum node_stat_item idx
, int val
)
771 struct page
*page
= virt_to_head_page(p
);
772 pg_data_t
*pgdat
= page_pgdat(page
);
773 struct mem_cgroup
*memcg
;
774 struct lruvec
*lruvec
;
777 memcg
= memcg_from_slab_page(page
);
780 * Untracked pages have no memcg, no lruvec. Update only the
781 * node. If we reparent the slab objects to the root memcg,
782 * when we free the slab object, we need to update the per-memcg
783 * vmstats to keep it correct for the root memcg.
786 __mod_node_page_state(pgdat
, idx
, val
);
788 lruvec
= mem_cgroup_lruvec(pgdat
, memcg
);
789 __mod_lruvec_state(lruvec
, idx
, val
);
794 void mod_memcg_obj_state(void *p
, int idx
, int val
)
796 struct mem_cgroup
*memcg
;
799 memcg
= mem_cgroup_from_obj(p
);
801 mod_memcg_state(memcg
, idx
, val
);
806 * __count_memcg_events - account VM events in a cgroup
807 * @memcg: the memory cgroup
808 * @idx: the event item
809 * @count: the number of events that occured
811 void __count_memcg_events(struct mem_cgroup
*memcg
, enum vm_event_item idx
,
816 if (mem_cgroup_disabled())
819 x
= count
+ __this_cpu_read(memcg
->vmstats_percpu
->events
[idx
]);
820 if (unlikely(x
> MEMCG_CHARGE_BATCH
)) {
821 struct mem_cgroup
*mi
;
824 * Batch local counters to keep them in sync with
825 * the hierarchical ones.
827 __this_cpu_add(memcg
->vmstats_local
->events
[idx
], x
);
828 for (mi
= memcg
; mi
; mi
= parent_mem_cgroup(mi
))
829 atomic_long_add(x
, &mi
->vmevents
[idx
]);
832 __this_cpu_write(memcg
->vmstats_percpu
->events
[idx
], x
);
835 static unsigned long memcg_events(struct mem_cgroup
*memcg
, int event
)
837 return atomic_long_read(&memcg
->vmevents
[event
]);
840 static unsigned long memcg_events_local(struct mem_cgroup
*memcg
, int event
)
845 for_each_possible_cpu(cpu
)
846 x
+= per_cpu(memcg
->vmstats_local
->events
[event
], cpu
);
850 static void mem_cgroup_charge_statistics(struct mem_cgroup
*memcg
,
852 bool compound
, int nr_pages
)
855 * Here, RSS means 'mapped anon' and anon's SwapCache. Shmem/tmpfs is
856 * counted as CACHE even if it's on ANON LRU.
859 __mod_memcg_state(memcg
, MEMCG_RSS
, nr_pages
);
861 __mod_memcg_state(memcg
, MEMCG_CACHE
, nr_pages
);
862 if (PageSwapBacked(page
))
863 __mod_memcg_state(memcg
, NR_SHMEM
, nr_pages
);
867 VM_BUG_ON_PAGE(!PageTransHuge(page
), page
);
868 __mod_memcg_state(memcg
, MEMCG_RSS_HUGE
, nr_pages
);
871 /* pagein of a big page is an event. So, ignore page size */
873 __count_memcg_events(memcg
, PGPGIN
, 1);
875 __count_memcg_events(memcg
, PGPGOUT
, 1);
876 nr_pages
= -nr_pages
; /* for event */
879 __this_cpu_add(memcg
->vmstats_percpu
->nr_page_events
, nr_pages
);
882 static bool mem_cgroup_event_ratelimit(struct mem_cgroup
*memcg
,
883 enum mem_cgroup_events_target target
)
885 unsigned long val
, next
;
887 val
= __this_cpu_read(memcg
->vmstats_percpu
->nr_page_events
);
888 next
= __this_cpu_read(memcg
->vmstats_percpu
->targets
[target
]);
889 /* from time_after() in jiffies.h */
890 if ((long)(next
- val
) < 0) {
892 case MEM_CGROUP_TARGET_THRESH
:
893 next
= val
+ THRESHOLDS_EVENTS_TARGET
;
895 case MEM_CGROUP_TARGET_SOFTLIMIT
:
896 next
= val
+ SOFTLIMIT_EVENTS_TARGET
;
898 case MEM_CGROUP_TARGET_NUMAINFO
:
899 next
= val
+ NUMAINFO_EVENTS_TARGET
;
904 __this_cpu_write(memcg
->vmstats_percpu
->targets
[target
], next
);
911 * Check events in order.
914 static void memcg_check_events(struct mem_cgroup
*memcg
, struct page
*page
)
916 /* threshold event is triggered in finer grain than soft limit */
917 if (unlikely(mem_cgroup_event_ratelimit(memcg
,
918 MEM_CGROUP_TARGET_THRESH
))) {
920 bool do_numainfo __maybe_unused
;
922 do_softlimit
= mem_cgroup_event_ratelimit(memcg
,
923 MEM_CGROUP_TARGET_SOFTLIMIT
);
925 do_numainfo
= mem_cgroup_event_ratelimit(memcg
,
926 MEM_CGROUP_TARGET_NUMAINFO
);
928 mem_cgroup_threshold(memcg
);
929 if (unlikely(do_softlimit
))
930 mem_cgroup_update_tree(memcg
, page
);
932 if (unlikely(do_numainfo
))
933 atomic_inc(&memcg
->numainfo_events
);
938 struct mem_cgroup
*mem_cgroup_from_task(struct task_struct
*p
)
941 * mm_update_next_owner() may clear mm->owner to NULL
942 * if it races with swapoff, page migration, etc.
943 * So this can be called with p == NULL.
948 return mem_cgroup_from_css(task_css(p
, memory_cgrp_id
));
950 EXPORT_SYMBOL(mem_cgroup_from_task
);
953 * get_mem_cgroup_from_mm: Obtain a reference on given mm_struct's memcg.
954 * @mm: mm from which memcg should be extracted. It can be NULL.
956 * Obtain a reference on mm->memcg and returns it if successful. Otherwise
957 * root_mem_cgroup is returned. However if mem_cgroup is disabled, NULL is
960 struct mem_cgroup
*get_mem_cgroup_from_mm(struct mm_struct
*mm
)
962 struct mem_cgroup
*memcg
;
964 if (mem_cgroup_disabled())
970 * Page cache insertions can happen withou an
971 * actual mm context, e.g. during disk probing
972 * on boot, loopback IO, acct() writes etc.
975 memcg
= root_mem_cgroup
;
977 memcg
= mem_cgroup_from_task(rcu_dereference(mm
->owner
));
978 if (unlikely(!memcg
))
979 memcg
= root_mem_cgroup
;
981 } while (!css_tryget(&memcg
->css
));
985 EXPORT_SYMBOL(get_mem_cgroup_from_mm
);
988 * get_mem_cgroup_from_page: Obtain a reference on given page's memcg.
989 * @page: page from which memcg should be extracted.
991 * Obtain a reference on page->memcg and returns it if successful. Otherwise
992 * root_mem_cgroup is returned.
994 struct mem_cgroup
*get_mem_cgroup_from_page(struct page
*page
)
996 struct mem_cgroup
*memcg
= page
->mem_cgroup
;
998 if (mem_cgroup_disabled())
1002 if (!memcg
|| !css_tryget_online(&memcg
->css
))
1003 memcg
= root_mem_cgroup
;
1007 EXPORT_SYMBOL(get_mem_cgroup_from_page
);
1010 * If current->active_memcg is non-NULL, do not fallback to current->mm->memcg.
1012 static __always_inline
struct mem_cgroup
*get_mem_cgroup_from_current(void)
1014 if (unlikely(current
->active_memcg
)) {
1015 struct mem_cgroup
*memcg
= root_mem_cgroup
;
1018 if (css_tryget_online(¤t
->active_memcg
->css
))
1019 memcg
= current
->active_memcg
;
1023 return get_mem_cgroup_from_mm(current
->mm
);
1027 * mem_cgroup_iter - iterate over memory cgroup hierarchy
1028 * @root: hierarchy root
1029 * @prev: previously returned memcg, NULL on first invocation
1030 * @reclaim: cookie for shared reclaim walks, NULL for full walks
1032 * Returns references to children of the hierarchy below @root, or
1033 * @root itself, or %NULL after a full round-trip.
1035 * Caller must pass the return value in @prev on subsequent
1036 * invocations for reference counting, or use mem_cgroup_iter_break()
1037 * to cancel a hierarchy walk before the round-trip is complete.
1039 * Reclaimers can specify a node and a priority level in @reclaim to
1040 * divide up the memcgs in the hierarchy among all concurrent
1041 * reclaimers operating on the same node and priority.
1043 struct mem_cgroup
*mem_cgroup_iter(struct mem_cgroup
*root
,
1044 struct mem_cgroup
*prev
,
1045 struct mem_cgroup_reclaim_cookie
*reclaim
)
1047 struct mem_cgroup_reclaim_iter
*uninitialized_var(iter
);
1048 struct cgroup_subsys_state
*css
= NULL
;
1049 struct mem_cgroup
*memcg
= NULL
;
1050 struct mem_cgroup
*pos
= NULL
;
1052 if (mem_cgroup_disabled())
1056 root
= root_mem_cgroup
;
1058 if (prev
&& !reclaim
)
1061 if (!root
->use_hierarchy
&& root
!= root_mem_cgroup
) {
1070 struct mem_cgroup_per_node
*mz
;
1072 mz
= mem_cgroup_nodeinfo(root
, reclaim
->pgdat
->node_id
);
1073 iter
= &mz
->iter
[reclaim
->priority
];
1075 if (prev
&& reclaim
->generation
!= iter
->generation
)
1079 pos
= READ_ONCE(iter
->position
);
1080 if (!pos
|| css_tryget(&pos
->css
))
1083 * css reference reached zero, so iter->position will
1084 * be cleared by ->css_released. However, we should not
1085 * rely on this happening soon, because ->css_released
1086 * is called from a work queue, and by busy-waiting we
1087 * might block it. So we clear iter->position right
1090 (void)cmpxchg(&iter
->position
, pos
, NULL
);
1098 css
= css_next_descendant_pre(css
, &root
->css
);
1101 * Reclaimers share the hierarchy walk, and a
1102 * new one might jump in right at the end of
1103 * the hierarchy - make sure they see at least
1104 * one group and restart from the beginning.
1112 * Verify the css and acquire a reference. The root
1113 * is provided by the caller, so we know it's alive
1114 * and kicking, and don't take an extra reference.
1116 memcg
= mem_cgroup_from_css(css
);
1118 if (css
== &root
->css
)
1121 if (css_tryget(css
))
1129 * The position could have already been updated by a competing
1130 * thread, so check that the value hasn't changed since we read
1131 * it to avoid reclaiming from the same cgroup twice.
1133 (void)cmpxchg(&iter
->position
, pos
, memcg
);
1141 reclaim
->generation
= iter
->generation
;
1147 if (prev
&& prev
!= root
)
1148 css_put(&prev
->css
);
1154 * mem_cgroup_iter_break - abort a hierarchy walk prematurely
1155 * @root: hierarchy root
1156 * @prev: last visited hierarchy member as returned by mem_cgroup_iter()
1158 void mem_cgroup_iter_break(struct mem_cgroup
*root
,
1159 struct mem_cgroup
*prev
)
1162 root
= root_mem_cgroup
;
1163 if (prev
&& prev
!= root
)
1164 css_put(&prev
->css
);
1167 static void __invalidate_reclaim_iterators(struct mem_cgroup
*from
,
1168 struct mem_cgroup
*dead_memcg
)
1170 struct mem_cgroup_reclaim_iter
*iter
;
1171 struct mem_cgroup_per_node
*mz
;
1175 for_each_node(nid
) {
1176 mz
= mem_cgroup_nodeinfo(from
, nid
);
1177 for (i
= 0; i
<= DEF_PRIORITY
; i
++) {
1178 iter
= &mz
->iter
[i
];
1179 cmpxchg(&iter
->position
,
1185 static void invalidate_reclaim_iterators(struct mem_cgroup
*dead_memcg
)
1187 struct mem_cgroup
*memcg
= dead_memcg
;
1188 struct mem_cgroup
*last
;
1191 __invalidate_reclaim_iterators(memcg
, dead_memcg
);
1193 } while ((memcg
= parent_mem_cgroup(memcg
)));
1196 * When cgruop1 non-hierarchy mode is used,
1197 * parent_mem_cgroup() does not walk all the way up to the
1198 * cgroup root (root_mem_cgroup). So we have to handle
1199 * dead_memcg from cgroup root separately.
1201 if (last
!= root_mem_cgroup
)
1202 __invalidate_reclaim_iterators(root_mem_cgroup
,
1207 * mem_cgroup_scan_tasks - iterate over tasks of a memory cgroup hierarchy
1208 * @memcg: hierarchy root
1209 * @fn: function to call for each task
1210 * @arg: argument passed to @fn
1212 * This function iterates over tasks attached to @memcg or to any of its
1213 * descendants and calls @fn for each task. If @fn returns a non-zero
1214 * value, the function breaks the iteration loop and returns the value.
1215 * Otherwise, it will iterate over all tasks and return 0.
1217 * This function must not be called for the root memory cgroup.
1219 int mem_cgroup_scan_tasks(struct mem_cgroup
*memcg
,
1220 int (*fn
)(struct task_struct
*, void *), void *arg
)
1222 struct mem_cgroup
*iter
;
1225 BUG_ON(memcg
== root_mem_cgroup
);
1227 for_each_mem_cgroup_tree(iter
, memcg
) {
1228 struct css_task_iter it
;
1229 struct task_struct
*task
;
1231 css_task_iter_start(&iter
->css
, CSS_TASK_ITER_PROCS
, &it
);
1232 while (!ret
&& (task
= css_task_iter_next(&it
)))
1233 ret
= fn(task
, arg
);
1234 css_task_iter_end(&it
);
1236 mem_cgroup_iter_break(memcg
, iter
);
1244 * mem_cgroup_page_lruvec - return lruvec for isolating/putting an LRU page
1246 * @pgdat: pgdat of the page
1248 * This function is only safe when following the LRU page isolation
1249 * and putback protocol: the LRU lock must be held, and the page must
1250 * either be PageLRU() or the caller must have isolated/allocated it.
1252 struct lruvec
*mem_cgroup_page_lruvec(struct page
*page
, struct pglist_data
*pgdat
)
1254 struct mem_cgroup_per_node
*mz
;
1255 struct mem_cgroup
*memcg
;
1256 struct lruvec
*lruvec
;
1258 if (mem_cgroup_disabled()) {
1259 lruvec
= &pgdat
->lruvec
;
1263 memcg
= page
->mem_cgroup
;
1265 * Swapcache readahead pages are added to the LRU - and
1266 * possibly migrated - before they are charged.
1269 memcg
= root_mem_cgroup
;
1271 mz
= mem_cgroup_page_nodeinfo(memcg
, page
);
1272 lruvec
= &mz
->lruvec
;
1275 * Since a node can be onlined after the mem_cgroup was created,
1276 * we have to be prepared to initialize lruvec->zone here;
1277 * and if offlined then reonlined, we need to reinitialize it.
1279 if (unlikely(lruvec
->pgdat
!= pgdat
))
1280 lruvec
->pgdat
= pgdat
;
1285 * mem_cgroup_update_lru_size - account for adding or removing an lru page
1286 * @lruvec: mem_cgroup per zone lru vector
1287 * @lru: index of lru list the page is sitting on
1288 * @zid: zone id of the accounted pages
1289 * @nr_pages: positive when adding or negative when removing
1291 * This function must be called under lru_lock, just before a page is added
1292 * to or just after a page is removed from an lru list (that ordering being
1293 * so as to allow it to check that lru_size 0 is consistent with list_empty).
1295 void mem_cgroup_update_lru_size(struct lruvec
*lruvec
, enum lru_list lru
,
1296 int zid
, int nr_pages
)
1298 struct mem_cgroup_per_node
*mz
;
1299 unsigned long *lru_size
;
1302 if (mem_cgroup_disabled())
1305 mz
= container_of(lruvec
, struct mem_cgroup_per_node
, lruvec
);
1306 lru_size
= &mz
->lru_zone_size
[zid
][lru
];
1309 *lru_size
+= nr_pages
;
1312 if (WARN_ONCE(size
< 0,
1313 "%s(%p, %d, %d): lru_size %ld\n",
1314 __func__
, lruvec
, lru
, nr_pages
, size
)) {
1320 *lru_size
+= nr_pages
;
1324 * mem_cgroup_margin - calculate chargeable space of a memory cgroup
1325 * @memcg: the memory cgroup
1327 * Returns the maximum amount of memory @mem can be charged with, in
1330 static unsigned long mem_cgroup_margin(struct mem_cgroup
*memcg
)
1332 unsigned long margin
= 0;
1333 unsigned long count
;
1334 unsigned long limit
;
1336 count
= page_counter_read(&memcg
->memory
);
1337 limit
= READ_ONCE(memcg
->memory
.max
);
1339 margin
= limit
- count
;
1341 if (do_memsw_account()) {
1342 count
= page_counter_read(&memcg
->memsw
);
1343 limit
= READ_ONCE(memcg
->memsw
.max
);
1345 margin
= min(margin
, limit
- count
);
1354 * A routine for checking "mem" is under move_account() or not.
1356 * Checking a cgroup is mc.from or mc.to or under hierarchy of
1357 * moving cgroups. This is for waiting at high-memory pressure
1360 static bool mem_cgroup_under_move(struct mem_cgroup
*memcg
)
1362 struct mem_cgroup
*from
;
1363 struct mem_cgroup
*to
;
1366 * Unlike task_move routines, we access mc.to, mc.from not under
1367 * mutual exclusion by cgroup_mutex. Here, we take spinlock instead.
1369 spin_lock(&mc
.lock
);
1375 ret
= mem_cgroup_is_descendant(from
, memcg
) ||
1376 mem_cgroup_is_descendant(to
, memcg
);
1378 spin_unlock(&mc
.lock
);
1382 static bool mem_cgroup_wait_acct_move(struct mem_cgroup
*memcg
)
1384 if (mc
.moving_task
&& current
!= mc
.moving_task
) {
1385 if (mem_cgroup_under_move(memcg
)) {
1387 prepare_to_wait(&mc
.waitq
, &wait
, TASK_INTERRUPTIBLE
);
1388 /* moving charge context might have finished. */
1391 finish_wait(&mc
.waitq
, &wait
);
1398 static char *memory_stat_format(struct mem_cgroup
*memcg
)
1403 seq_buf_init(&s
, kmalloc(PAGE_SIZE
, GFP_KERNEL
), PAGE_SIZE
);
1408 * Provide statistics on the state of the memory subsystem as
1409 * well as cumulative event counters that show past behavior.
1411 * This list is ordered following a combination of these gradients:
1412 * 1) generic big picture -> specifics and details
1413 * 2) reflecting userspace activity -> reflecting kernel heuristics
1415 * Current memory state:
1418 seq_buf_printf(&s
, "anon %llu\n",
1419 (u64
)memcg_page_state(memcg
, MEMCG_RSS
) *
1421 seq_buf_printf(&s
, "file %llu\n",
1422 (u64
)memcg_page_state(memcg
, MEMCG_CACHE
) *
1424 seq_buf_printf(&s
, "kernel_stack %llu\n",
1425 (u64
)memcg_page_state(memcg
, MEMCG_KERNEL_STACK_KB
) *
1427 seq_buf_printf(&s
, "slab %llu\n",
1428 (u64
)(memcg_page_state(memcg
, NR_SLAB_RECLAIMABLE
) +
1429 memcg_page_state(memcg
, NR_SLAB_UNRECLAIMABLE
)) *
1431 seq_buf_printf(&s
, "sock %llu\n",
1432 (u64
)memcg_page_state(memcg
, MEMCG_SOCK
) *
1435 seq_buf_printf(&s
, "shmem %llu\n",
1436 (u64
)memcg_page_state(memcg
, NR_SHMEM
) *
1438 seq_buf_printf(&s
, "file_mapped %llu\n",
1439 (u64
)memcg_page_state(memcg
, NR_FILE_MAPPED
) *
1441 seq_buf_printf(&s
, "file_dirty %llu\n",
1442 (u64
)memcg_page_state(memcg
, NR_FILE_DIRTY
) *
1444 seq_buf_printf(&s
, "file_writeback %llu\n",
1445 (u64
)memcg_page_state(memcg
, NR_WRITEBACK
) *
1449 * TODO: We should eventually replace our own MEMCG_RSS_HUGE counter
1450 * with the NR_ANON_THP vm counter, but right now it's a pain in the
1451 * arse because it requires migrating the work out of rmap to a place
1452 * where the page->mem_cgroup is set up and stable.
1454 seq_buf_printf(&s
, "anon_thp %llu\n",
1455 (u64
)memcg_page_state(memcg
, MEMCG_RSS_HUGE
) *
1458 for (i
= 0; i
< NR_LRU_LISTS
; i
++)
1459 seq_buf_printf(&s
, "%s %llu\n", mem_cgroup_lru_names
[i
],
1460 (u64
)memcg_page_state(memcg
, NR_LRU_BASE
+ i
) *
1463 seq_buf_printf(&s
, "slab_reclaimable %llu\n",
1464 (u64
)memcg_page_state(memcg
, NR_SLAB_RECLAIMABLE
) *
1466 seq_buf_printf(&s
, "slab_unreclaimable %llu\n",
1467 (u64
)memcg_page_state(memcg
, NR_SLAB_UNRECLAIMABLE
) *
1470 /* Accumulated memory events */
1472 seq_buf_printf(&s
, "pgfault %lu\n", memcg_events(memcg
, PGFAULT
));
1473 seq_buf_printf(&s
, "pgmajfault %lu\n", memcg_events(memcg
, PGMAJFAULT
));
1475 seq_buf_printf(&s
, "workingset_refault %lu\n",
1476 memcg_page_state(memcg
, WORKINGSET_REFAULT
));
1477 seq_buf_printf(&s
, "workingset_activate %lu\n",
1478 memcg_page_state(memcg
, WORKINGSET_ACTIVATE
));
1479 seq_buf_printf(&s
, "workingset_nodereclaim %lu\n",
1480 memcg_page_state(memcg
, WORKINGSET_NODERECLAIM
));
1482 seq_buf_printf(&s
, "pgrefill %lu\n", memcg_events(memcg
, PGREFILL
));
1483 seq_buf_printf(&s
, "pgscan %lu\n",
1484 memcg_events(memcg
, PGSCAN_KSWAPD
) +
1485 memcg_events(memcg
, PGSCAN_DIRECT
));
1486 seq_buf_printf(&s
, "pgsteal %lu\n",
1487 memcg_events(memcg
, PGSTEAL_KSWAPD
) +
1488 memcg_events(memcg
, PGSTEAL_DIRECT
));
1489 seq_buf_printf(&s
, "pgactivate %lu\n", memcg_events(memcg
, PGACTIVATE
));
1490 seq_buf_printf(&s
, "pgdeactivate %lu\n", memcg_events(memcg
, PGDEACTIVATE
));
1491 seq_buf_printf(&s
, "pglazyfree %lu\n", memcg_events(memcg
, PGLAZYFREE
));
1492 seq_buf_printf(&s
, "pglazyfreed %lu\n", memcg_events(memcg
, PGLAZYFREED
));
1494 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
1495 seq_buf_printf(&s
, "thp_fault_alloc %lu\n",
1496 memcg_events(memcg
, THP_FAULT_ALLOC
));
1497 seq_buf_printf(&s
, "thp_collapse_alloc %lu\n",
1498 memcg_events(memcg
, THP_COLLAPSE_ALLOC
));
1499 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
1501 /* The above should easily fit into one page */
1502 WARN_ON_ONCE(seq_buf_has_overflowed(&s
));
1507 #define K(x) ((x) << (PAGE_SHIFT-10))
1509 * mem_cgroup_print_oom_context: Print OOM information relevant to
1510 * memory controller.
1511 * @memcg: The memory cgroup that went over limit
1512 * @p: Task that is going to be killed
1514 * NOTE: @memcg and @p's mem_cgroup can be different when hierarchy is
1517 void mem_cgroup_print_oom_context(struct mem_cgroup
*memcg
, struct task_struct
*p
)
1522 pr_cont(",oom_memcg=");
1523 pr_cont_cgroup_path(memcg
->css
.cgroup
);
1525 pr_cont(",global_oom");
1527 pr_cont(",task_memcg=");
1528 pr_cont_cgroup_path(task_cgroup(p
, memory_cgrp_id
));
1534 * mem_cgroup_print_oom_meminfo: Print OOM memory information relevant to
1535 * memory controller.
1536 * @memcg: The memory cgroup that went over limit
1538 void mem_cgroup_print_oom_meminfo(struct mem_cgroup
*memcg
)
1542 pr_info("memory: usage %llukB, limit %llukB, failcnt %lu\n",
1543 K((u64
)page_counter_read(&memcg
->memory
)),
1544 K((u64
)memcg
->memory
.max
), memcg
->memory
.failcnt
);
1545 if (cgroup_subsys_on_dfl(memory_cgrp_subsys
))
1546 pr_info("swap: usage %llukB, limit %llukB, failcnt %lu\n",
1547 K((u64
)page_counter_read(&memcg
->swap
)),
1548 K((u64
)memcg
->swap
.max
), memcg
->swap
.failcnt
);
1550 pr_info("memory+swap: usage %llukB, limit %llukB, failcnt %lu\n",
1551 K((u64
)page_counter_read(&memcg
->memsw
)),
1552 K((u64
)memcg
->memsw
.max
), memcg
->memsw
.failcnt
);
1553 pr_info("kmem: usage %llukB, limit %llukB, failcnt %lu\n",
1554 K((u64
)page_counter_read(&memcg
->kmem
)),
1555 K((u64
)memcg
->kmem
.max
), memcg
->kmem
.failcnt
);
1558 pr_info("Memory cgroup stats for ");
1559 pr_cont_cgroup_path(memcg
->css
.cgroup
);
1561 buf
= memory_stat_format(memcg
);
1569 * Return the memory (and swap, if configured) limit for a memcg.
1571 unsigned long mem_cgroup_get_max(struct mem_cgroup
*memcg
)
1575 max
= memcg
->memory
.max
;
1576 if (mem_cgroup_swappiness(memcg
)) {
1577 unsigned long memsw_max
;
1578 unsigned long swap_max
;
1580 memsw_max
= memcg
->memsw
.max
;
1581 swap_max
= memcg
->swap
.max
;
1582 swap_max
= min(swap_max
, (unsigned long)total_swap_pages
);
1583 max
= min(max
+ swap_max
, memsw_max
);
1588 unsigned long mem_cgroup_size(struct mem_cgroup
*memcg
)
1590 return page_counter_read(&memcg
->memory
);
1593 static bool mem_cgroup_out_of_memory(struct mem_cgroup
*memcg
, gfp_t gfp_mask
,
1596 struct oom_control oc
= {
1600 .gfp_mask
= gfp_mask
,
1605 if (mutex_lock_killable(&oom_lock
))
1608 * A few threads which were not waiting at mutex_lock_killable() can
1609 * fail to bail out. Therefore, check again after holding oom_lock.
1611 ret
= should_force_charge() || out_of_memory(&oc
);
1612 mutex_unlock(&oom_lock
);
1616 #if MAX_NUMNODES > 1
1619 * test_mem_cgroup_node_reclaimable
1620 * @memcg: the target memcg
1621 * @nid: the node ID to be checked.
1622 * @noswap : specify true here if the user wants flle only information.
1624 * This function returns whether the specified memcg contains any
1625 * reclaimable pages on a node. Returns true if there are any reclaimable
1626 * pages in the node.
1628 static bool test_mem_cgroup_node_reclaimable(struct mem_cgroup
*memcg
,
1629 int nid
, bool noswap
)
1631 struct lruvec
*lruvec
= mem_cgroup_lruvec(NODE_DATA(nid
), memcg
);
1633 if (lruvec_page_state(lruvec
, NR_INACTIVE_FILE
) ||
1634 lruvec_page_state(lruvec
, NR_ACTIVE_FILE
))
1636 if (noswap
|| !total_swap_pages
)
1638 if (lruvec_page_state(lruvec
, NR_INACTIVE_ANON
) ||
1639 lruvec_page_state(lruvec
, NR_ACTIVE_ANON
))
1646 * Always updating the nodemask is not very good - even if we have an empty
1647 * list or the wrong list here, we can start from some node and traverse all
1648 * nodes based on the zonelist. So update the list loosely once per 10 secs.
1651 static void mem_cgroup_may_update_nodemask(struct mem_cgroup
*memcg
)
1655 * numainfo_events > 0 means there was at least NUMAINFO_EVENTS_TARGET
1656 * pagein/pageout changes since the last update.
1658 if (!atomic_read(&memcg
->numainfo_events
))
1660 if (atomic_inc_return(&memcg
->numainfo_updating
) > 1)
1663 /* make a nodemask where this memcg uses memory from */
1664 memcg
->scan_nodes
= node_states
[N_MEMORY
];
1666 for_each_node_mask(nid
, node_states
[N_MEMORY
]) {
1668 if (!test_mem_cgroup_node_reclaimable(memcg
, nid
, false))
1669 node_clear(nid
, memcg
->scan_nodes
);
1672 atomic_set(&memcg
->numainfo_events
, 0);
1673 atomic_set(&memcg
->numainfo_updating
, 0);
1677 * Selecting a node where we start reclaim from. Because what we need is just
1678 * reducing usage counter, start from anywhere is O,K. Considering
1679 * memory reclaim from current node, there are pros. and cons.
1681 * Freeing memory from current node means freeing memory from a node which
1682 * we'll use or we've used. So, it may make LRU bad. And if several threads
1683 * hit limits, it will see a contention on a node. But freeing from remote
1684 * node means more costs for memory reclaim because of memory latency.
1686 * Now, we use round-robin. Better algorithm is welcomed.
1688 int mem_cgroup_select_victim_node(struct mem_cgroup
*memcg
)
1692 mem_cgroup_may_update_nodemask(memcg
);
1693 node
= memcg
->last_scanned_node
;
1695 node
= next_node_in(node
, memcg
->scan_nodes
);
1697 * mem_cgroup_may_update_nodemask might have seen no reclaimmable pages
1698 * last time it really checked all the LRUs due to rate limiting.
1699 * Fallback to the current node in that case for simplicity.
1701 if (unlikely(node
== MAX_NUMNODES
))
1702 node
= numa_node_id();
1704 memcg
->last_scanned_node
= node
;
1708 int mem_cgroup_select_victim_node(struct mem_cgroup
*memcg
)
1714 static int mem_cgroup_soft_reclaim(struct mem_cgroup
*root_memcg
,
1717 unsigned long *total_scanned
)
1719 struct mem_cgroup
*victim
= NULL
;
1722 unsigned long excess
;
1723 unsigned long nr_scanned
;
1724 struct mem_cgroup_reclaim_cookie reclaim
= {
1729 excess
= soft_limit_excess(root_memcg
);
1732 victim
= mem_cgroup_iter(root_memcg
, victim
, &reclaim
);
1737 * If we have not been able to reclaim
1738 * anything, it might because there are
1739 * no reclaimable pages under this hierarchy
1744 * We want to do more targeted reclaim.
1745 * excess >> 2 is not to excessive so as to
1746 * reclaim too much, nor too less that we keep
1747 * coming back to reclaim from this cgroup
1749 if (total
>= (excess
>> 2) ||
1750 (loop
> MEM_CGROUP_MAX_RECLAIM_LOOPS
))
1755 total
+= mem_cgroup_shrink_node(victim
, gfp_mask
, false,
1756 pgdat
, &nr_scanned
);
1757 *total_scanned
+= nr_scanned
;
1758 if (!soft_limit_excess(root_memcg
))
1761 mem_cgroup_iter_break(root_memcg
, victim
);
1765 #ifdef CONFIG_LOCKDEP
1766 static struct lockdep_map memcg_oom_lock_dep_map
= {
1767 .name
= "memcg_oom_lock",
1771 static DEFINE_SPINLOCK(memcg_oom_lock
);
1774 * Check OOM-Killer is already running under our hierarchy.
1775 * If someone is running, return false.
1777 static bool mem_cgroup_oom_trylock(struct mem_cgroup
*memcg
)
1779 struct mem_cgroup
*iter
, *failed
= NULL
;
1781 spin_lock(&memcg_oom_lock
);
1783 for_each_mem_cgroup_tree(iter
, memcg
) {
1784 if (iter
->oom_lock
) {
1786 * this subtree of our hierarchy is already locked
1787 * so we cannot give a lock.
1790 mem_cgroup_iter_break(memcg
, iter
);
1793 iter
->oom_lock
= true;
1798 * OK, we failed to lock the whole subtree so we have
1799 * to clean up what we set up to the failing subtree
1801 for_each_mem_cgroup_tree(iter
, memcg
) {
1802 if (iter
== failed
) {
1803 mem_cgroup_iter_break(memcg
, iter
);
1806 iter
->oom_lock
= false;
1809 mutex_acquire(&memcg_oom_lock_dep_map
, 0, 1, _RET_IP_
);
1811 spin_unlock(&memcg_oom_lock
);
1816 static void mem_cgroup_oom_unlock(struct mem_cgroup
*memcg
)
1818 struct mem_cgroup
*iter
;
1820 spin_lock(&memcg_oom_lock
);
1821 mutex_release(&memcg_oom_lock_dep_map
, 1, _RET_IP_
);
1822 for_each_mem_cgroup_tree(iter
, memcg
)
1823 iter
->oom_lock
= false;
1824 spin_unlock(&memcg_oom_lock
);
1827 static void mem_cgroup_mark_under_oom(struct mem_cgroup
*memcg
)
1829 struct mem_cgroup
*iter
;
1831 spin_lock(&memcg_oom_lock
);
1832 for_each_mem_cgroup_tree(iter
, memcg
)
1834 spin_unlock(&memcg_oom_lock
);
1837 static void mem_cgroup_unmark_under_oom(struct mem_cgroup
*memcg
)
1839 struct mem_cgroup
*iter
;
1842 * When a new child is created while the hierarchy is under oom,
1843 * mem_cgroup_oom_lock() may not be called. Watch for underflow.
1845 spin_lock(&memcg_oom_lock
);
1846 for_each_mem_cgroup_tree(iter
, memcg
)
1847 if (iter
->under_oom
> 0)
1849 spin_unlock(&memcg_oom_lock
);
1852 static DECLARE_WAIT_QUEUE_HEAD(memcg_oom_waitq
);
1854 struct oom_wait_info
{
1855 struct mem_cgroup
*memcg
;
1856 wait_queue_entry_t wait
;
1859 static int memcg_oom_wake_function(wait_queue_entry_t
*wait
,
1860 unsigned mode
, int sync
, void *arg
)
1862 struct mem_cgroup
*wake_memcg
= (struct mem_cgroup
*)arg
;
1863 struct mem_cgroup
*oom_wait_memcg
;
1864 struct oom_wait_info
*oom_wait_info
;
1866 oom_wait_info
= container_of(wait
, struct oom_wait_info
, wait
);
1867 oom_wait_memcg
= oom_wait_info
->memcg
;
1869 if (!mem_cgroup_is_descendant(wake_memcg
, oom_wait_memcg
) &&
1870 !mem_cgroup_is_descendant(oom_wait_memcg
, wake_memcg
))
1872 return autoremove_wake_function(wait
, mode
, sync
, arg
);
1875 static void memcg_oom_recover(struct mem_cgroup
*memcg
)
1878 * For the following lockless ->under_oom test, the only required
1879 * guarantee is that it must see the state asserted by an OOM when
1880 * this function is called as a result of userland actions
1881 * triggered by the notification of the OOM. This is trivially
1882 * achieved by invoking mem_cgroup_mark_under_oom() before
1883 * triggering notification.
1885 if (memcg
&& memcg
->under_oom
)
1886 __wake_up(&memcg_oom_waitq
, TASK_NORMAL
, 0, memcg
);
1896 static enum oom_status
mem_cgroup_oom(struct mem_cgroup
*memcg
, gfp_t mask
, int order
)
1898 enum oom_status ret
;
1901 if (order
> PAGE_ALLOC_COSTLY_ORDER
)
1904 memcg_memory_event(memcg
, MEMCG_OOM
);
1907 * We are in the middle of the charge context here, so we
1908 * don't want to block when potentially sitting on a callstack
1909 * that holds all kinds of filesystem and mm locks.
1911 * cgroup1 allows disabling the OOM killer and waiting for outside
1912 * handling until the charge can succeed; remember the context and put
1913 * the task to sleep at the end of the page fault when all locks are
1916 * On the other hand, in-kernel OOM killer allows for an async victim
1917 * memory reclaim (oom_reaper) and that means that we are not solely
1918 * relying on the oom victim to make a forward progress and we can
1919 * invoke the oom killer here.
1921 * Please note that mem_cgroup_out_of_memory might fail to find a
1922 * victim and then we have to bail out from the charge path.
1924 if (memcg
->oom_kill_disable
) {
1925 if (!current
->in_user_fault
)
1927 css_get(&memcg
->css
);
1928 current
->memcg_in_oom
= memcg
;
1929 current
->memcg_oom_gfp_mask
= mask
;
1930 current
->memcg_oom_order
= order
;
1935 mem_cgroup_mark_under_oom(memcg
);
1937 locked
= mem_cgroup_oom_trylock(memcg
);
1940 mem_cgroup_oom_notify(memcg
);
1942 mem_cgroup_unmark_under_oom(memcg
);
1943 if (mem_cgroup_out_of_memory(memcg
, mask
, order
))
1949 mem_cgroup_oom_unlock(memcg
);
1955 * mem_cgroup_oom_synchronize - complete memcg OOM handling
1956 * @handle: actually kill/wait or just clean up the OOM state
1958 * This has to be called at the end of a page fault if the memcg OOM
1959 * handler was enabled.
1961 * Memcg supports userspace OOM handling where failed allocations must
1962 * sleep on a waitqueue until the userspace task resolves the
1963 * situation. Sleeping directly in the charge context with all kinds
1964 * of locks held is not a good idea, instead we remember an OOM state
1965 * in the task and mem_cgroup_oom_synchronize() has to be called at
1966 * the end of the page fault to complete the OOM handling.
1968 * Returns %true if an ongoing memcg OOM situation was detected and
1969 * completed, %false otherwise.
1971 bool mem_cgroup_oom_synchronize(bool handle
)
1973 struct mem_cgroup
*memcg
= current
->memcg_in_oom
;
1974 struct oom_wait_info owait
;
1977 /* OOM is global, do not handle */
1984 owait
.memcg
= memcg
;
1985 owait
.wait
.flags
= 0;
1986 owait
.wait
.func
= memcg_oom_wake_function
;
1987 owait
.wait
.private = current
;
1988 INIT_LIST_HEAD(&owait
.wait
.entry
);
1990 prepare_to_wait(&memcg_oom_waitq
, &owait
.wait
, TASK_KILLABLE
);
1991 mem_cgroup_mark_under_oom(memcg
);
1993 locked
= mem_cgroup_oom_trylock(memcg
);
1996 mem_cgroup_oom_notify(memcg
);
1998 if (locked
&& !memcg
->oom_kill_disable
) {
1999 mem_cgroup_unmark_under_oom(memcg
);
2000 finish_wait(&memcg_oom_waitq
, &owait
.wait
);
2001 mem_cgroup_out_of_memory(memcg
, current
->memcg_oom_gfp_mask
,
2002 current
->memcg_oom_order
);
2005 mem_cgroup_unmark_under_oom(memcg
);
2006 finish_wait(&memcg_oom_waitq
, &owait
.wait
);
2010 mem_cgroup_oom_unlock(memcg
);
2012 * There is no guarantee that an OOM-lock contender
2013 * sees the wakeups triggered by the OOM kill
2014 * uncharges. Wake any sleepers explicitely.
2016 memcg_oom_recover(memcg
);
2019 current
->memcg_in_oom
= NULL
;
2020 css_put(&memcg
->css
);
2025 * mem_cgroup_get_oom_group - get a memory cgroup to clean up after OOM
2026 * @victim: task to be killed by the OOM killer
2027 * @oom_domain: memcg in case of memcg OOM, NULL in case of system-wide OOM
2029 * Returns a pointer to a memory cgroup, which has to be cleaned up
2030 * by killing all belonging OOM-killable tasks.
2032 * Caller has to call mem_cgroup_put() on the returned non-NULL memcg.
2034 struct mem_cgroup
*mem_cgroup_get_oom_group(struct task_struct
*victim
,
2035 struct mem_cgroup
*oom_domain
)
2037 struct mem_cgroup
*oom_group
= NULL
;
2038 struct mem_cgroup
*memcg
;
2040 if (!cgroup_subsys_on_dfl(memory_cgrp_subsys
))
2044 oom_domain
= root_mem_cgroup
;
2048 memcg
= mem_cgroup_from_task(victim
);
2049 if (memcg
== root_mem_cgroup
)
2053 * Traverse the memory cgroup hierarchy from the victim task's
2054 * cgroup up to the OOMing cgroup (or root) to find the
2055 * highest-level memory cgroup with oom.group set.
2057 for (; memcg
; memcg
= parent_mem_cgroup(memcg
)) {
2058 if (memcg
->oom_group
)
2061 if (memcg
== oom_domain
)
2066 css_get(&oom_group
->css
);
2073 void mem_cgroup_print_oom_group(struct mem_cgroup
*memcg
)
2075 pr_info("Tasks in ");
2076 pr_cont_cgroup_path(memcg
->css
.cgroup
);
2077 pr_cont(" are going to be killed due to memory.oom.group set\n");
2081 * lock_page_memcg - lock a page->mem_cgroup binding
2084 * This function protects unlocked LRU pages from being moved to
2087 * It ensures lifetime of the returned memcg. Caller is responsible
2088 * for the lifetime of the page; __unlock_page_memcg() is available
2089 * when @page might get freed inside the locked section.
2091 struct mem_cgroup
*lock_page_memcg(struct page
*page
)
2093 struct mem_cgroup
*memcg
;
2094 unsigned long flags
;
2097 * The RCU lock is held throughout the transaction. The fast
2098 * path can get away without acquiring the memcg->move_lock
2099 * because page moving starts with an RCU grace period.
2101 * The RCU lock also protects the memcg from being freed when
2102 * the page state that is going to change is the only thing
2103 * preventing the page itself from being freed. E.g. writeback
2104 * doesn't hold a page reference and relies on PG_writeback to
2105 * keep off truncation, migration and so forth.
2109 if (mem_cgroup_disabled())
2112 memcg
= page
->mem_cgroup
;
2113 if (unlikely(!memcg
))
2116 if (atomic_read(&memcg
->moving_account
) <= 0)
2119 spin_lock_irqsave(&memcg
->move_lock
, flags
);
2120 if (memcg
!= page
->mem_cgroup
) {
2121 spin_unlock_irqrestore(&memcg
->move_lock
, flags
);
2126 * When charge migration first begins, we can have locked and
2127 * unlocked page stat updates happening concurrently. Track
2128 * the task who has the lock for unlock_page_memcg().
2130 memcg
->move_lock_task
= current
;
2131 memcg
->move_lock_flags
= flags
;
2135 EXPORT_SYMBOL(lock_page_memcg
);
2138 * __unlock_page_memcg - unlock and unpin a memcg
2141 * Unlock and unpin a memcg returned by lock_page_memcg().
2143 void __unlock_page_memcg(struct mem_cgroup
*memcg
)
2145 if (memcg
&& memcg
->move_lock_task
== current
) {
2146 unsigned long flags
= memcg
->move_lock_flags
;
2148 memcg
->move_lock_task
= NULL
;
2149 memcg
->move_lock_flags
= 0;
2151 spin_unlock_irqrestore(&memcg
->move_lock
, flags
);
2158 * unlock_page_memcg - unlock a page->mem_cgroup binding
2161 void unlock_page_memcg(struct page
*page
)
2163 __unlock_page_memcg(page
->mem_cgroup
);
2165 EXPORT_SYMBOL(unlock_page_memcg
);
2167 struct memcg_stock_pcp
{
2168 struct mem_cgroup
*cached
; /* this never be root cgroup */
2169 unsigned int nr_pages
;
2170 struct work_struct work
;
2171 unsigned long flags
;
2172 #define FLUSHING_CACHED_CHARGE 0
2174 static DEFINE_PER_CPU(struct memcg_stock_pcp
, memcg_stock
);
2175 static DEFINE_MUTEX(percpu_charge_mutex
);
2178 * consume_stock: Try to consume stocked charge on this cpu.
2179 * @memcg: memcg to consume from.
2180 * @nr_pages: how many pages to charge.
2182 * The charges will only happen if @memcg matches the current cpu's memcg
2183 * stock, and at least @nr_pages are available in that stock. Failure to
2184 * service an allocation will refill the stock.
2186 * returns true if successful, false otherwise.
2188 static bool consume_stock(struct mem_cgroup
*memcg
, unsigned int nr_pages
)
2190 struct memcg_stock_pcp
*stock
;
2191 unsigned long flags
;
2194 if (nr_pages
> MEMCG_CHARGE_BATCH
)
2197 local_irq_save(flags
);
2199 stock
= this_cpu_ptr(&memcg_stock
);
2200 if (memcg
== stock
->cached
&& stock
->nr_pages
>= nr_pages
) {
2201 stock
->nr_pages
-= nr_pages
;
2205 local_irq_restore(flags
);
2211 * Returns stocks cached in percpu and reset cached information.
2213 static void drain_stock(struct memcg_stock_pcp
*stock
)
2215 struct mem_cgroup
*old
= stock
->cached
;
2217 if (stock
->nr_pages
) {
2218 page_counter_uncharge(&old
->memory
, stock
->nr_pages
);
2219 if (do_memsw_account())
2220 page_counter_uncharge(&old
->memsw
, stock
->nr_pages
);
2221 css_put_many(&old
->css
, stock
->nr_pages
);
2222 stock
->nr_pages
= 0;
2224 stock
->cached
= NULL
;
2227 static void drain_local_stock(struct work_struct
*dummy
)
2229 struct memcg_stock_pcp
*stock
;
2230 unsigned long flags
;
2233 * The only protection from memory hotplug vs. drain_stock races is
2234 * that we always operate on local CPU stock here with IRQ disabled
2236 local_irq_save(flags
);
2238 stock
= this_cpu_ptr(&memcg_stock
);
2240 clear_bit(FLUSHING_CACHED_CHARGE
, &stock
->flags
);
2242 local_irq_restore(flags
);
2246 * Cache charges(val) to local per_cpu area.
2247 * This will be consumed by consume_stock() function, later.
2249 static void refill_stock(struct mem_cgroup
*memcg
, unsigned int nr_pages
)
2251 struct memcg_stock_pcp
*stock
;
2252 unsigned long flags
;
2254 local_irq_save(flags
);
2256 stock
= this_cpu_ptr(&memcg_stock
);
2257 if (stock
->cached
!= memcg
) { /* reset if necessary */
2259 stock
->cached
= memcg
;
2261 stock
->nr_pages
+= nr_pages
;
2263 if (stock
->nr_pages
> MEMCG_CHARGE_BATCH
)
2266 local_irq_restore(flags
);
2270 * Drains all per-CPU charge caches for given root_memcg resp. subtree
2271 * of the hierarchy under it.
2273 static void drain_all_stock(struct mem_cgroup
*root_memcg
)
2277 /* If someone's already draining, avoid adding running more workers. */
2278 if (!mutex_trylock(&percpu_charge_mutex
))
2281 * Notify other cpus that system-wide "drain" is running
2282 * We do not care about races with the cpu hotplug because cpu down
2283 * as well as workers from this path always operate on the local
2284 * per-cpu data. CPU up doesn't touch memcg_stock at all.
2287 for_each_online_cpu(cpu
) {
2288 struct memcg_stock_pcp
*stock
= &per_cpu(memcg_stock
, cpu
);
2289 struct mem_cgroup
*memcg
;
2293 memcg
= stock
->cached
;
2294 if (memcg
&& stock
->nr_pages
&&
2295 mem_cgroup_is_descendant(memcg
, root_memcg
))
2300 !test_and_set_bit(FLUSHING_CACHED_CHARGE
, &stock
->flags
)) {
2302 drain_local_stock(&stock
->work
);
2304 schedule_work_on(cpu
, &stock
->work
);
2308 mutex_unlock(&percpu_charge_mutex
);
2311 static int memcg_hotplug_cpu_dead(unsigned int cpu
)
2313 struct memcg_stock_pcp
*stock
;
2314 struct mem_cgroup
*memcg
, *mi
;
2316 stock
= &per_cpu(memcg_stock
, cpu
);
2319 for_each_mem_cgroup(memcg
) {
2322 for (i
= 0; i
< MEMCG_NR_STAT
; i
++) {
2326 x
= this_cpu_xchg(memcg
->vmstats_percpu
->stat
[i
], 0);
2328 for (mi
= memcg
; mi
; mi
= parent_mem_cgroup(mi
))
2329 atomic_long_add(x
, &memcg
->vmstats
[i
]);
2331 if (i
>= NR_VM_NODE_STAT_ITEMS
)
2334 for_each_node(nid
) {
2335 struct mem_cgroup_per_node
*pn
;
2337 pn
= mem_cgroup_nodeinfo(memcg
, nid
);
2338 x
= this_cpu_xchg(pn
->lruvec_stat_cpu
->count
[i
], 0);
2341 atomic_long_add(x
, &pn
->lruvec_stat
[i
]);
2342 } while ((pn
= parent_nodeinfo(pn
, nid
)));
2346 for (i
= 0; i
< NR_VM_EVENT_ITEMS
; i
++) {
2349 x
= this_cpu_xchg(memcg
->vmstats_percpu
->events
[i
], 0);
2351 for (mi
= memcg
; mi
; mi
= parent_mem_cgroup(mi
))
2352 atomic_long_add(x
, &memcg
->vmevents
[i
]);
2359 static void reclaim_high(struct mem_cgroup
*memcg
,
2360 unsigned int nr_pages
,
2364 if (page_counter_read(&memcg
->memory
) <= memcg
->high
)
2366 memcg_memory_event(memcg
, MEMCG_HIGH
);
2367 try_to_free_mem_cgroup_pages(memcg
, nr_pages
, gfp_mask
, true);
2368 } while ((memcg
= parent_mem_cgroup(memcg
)));
2371 static void high_work_func(struct work_struct
*work
)
2373 struct mem_cgroup
*memcg
;
2375 memcg
= container_of(work
, struct mem_cgroup
, high_work
);
2376 reclaim_high(memcg
, MEMCG_CHARGE_BATCH
, GFP_KERNEL
);
2380 * Clamp the maximum sleep time per allocation batch to 2 seconds. This is
2381 * enough to still cause a significant slowdown in most cases, while still
2382 * allowing diagnostics and tracing to proceed without becoming stuck.
2384 #define MEMCG_MAX_HIGH_DELAY_JIFFIES (2UL*HZ)
2387 * When calculating the delay, we use these either side of the exponentiation to
2388 * maintain precision and scale to a reasonable number of jiffies (see the table
2391 * - MEMCG_DELAY_PRECISION_SHIFT: Extra precision bits while translating the
2392 * overage ratio to a delay.
2393 * - MEMCG_DELAY_SCALING_SHIFT: The number of bits to scale down down the
2394 * proposed penalty in order to reduce to a reasonable number of jiffies, and
2395 * to produce a reasonable delay curve.
2397 * MEMCG_DELAY_SCALING_SHIFT just happens to be a number that produces a
2398 * reasonable delay curve compared to precision-adjusted overage, not
2399 * penalising heavily at first, but still making sure that growth beyond the
2400 * limit penalises misbehaviour cgroups by slowing them down exponentially. For
2401 * example, with a high of 100 megabytes:
2403 * +-------+------------------------+
2404 * | usage | time to allocate in ms |
2405 * +-------+------------------------+
2427 * +-------+------------------------+
2429 #define MEMCG_DELAY_PRECISION_SHIFT 20
2430 #define MEMCG_DELAY_SCALING_SHIFT 14
2433 * Get the number of jiffies that we should penalise a mischievous cgroup which
2434 * is exceeding its memory.high by checking both it and its ancestors.
2436 static unsigned long calculate_high_delay(struct mem_cgroup
*memcg
,
2437 unsigned int nr_pages
)
2439 unsigned long penalty_jiffies
;
2440 u64 max_overage
= 0;
2443 unsigned long usage
, high
;
2446 usage
= page_counter_read(&memcg
->memory
);
2447 high
= READ_ONCE(memcg
->high
);
2453 * Prevent division by 0 in overage calculation by acting as if
2454 * it was a threshold of 1 page
2456 high
= max(high
, 1UL);
2458 overage
= usage
- high
;
2459 overage
<<= MEMCG_DELAY_PRECISION_SHIFT
;
2460 overage
= div64_u64(overage
, high
);
2462 if (overage
> max_overage
)
2463 max_overage
= overage
;
2464 } while ((memcg
= parent_mem_cgroup(memcg
)) &&
2465 !mem_cgroup_is_root(memcg
));
2471 * We use overage compared to memory.high to calculate the number of
2472 * jiffies to sleep (penalty_jiffies). Ideally this value should be
2473 * fairly lenient on small overages, and increasingly harsh when the
2474 * memcg in question makes it clear that it has no intention of stopping
2475 * its crazy behaviour, so we exponentially increase the delay based on
2478 penalty_jiffies
= max_overage
* max_overage
* HZ
;
2479 penalty_jiffies
>>= MEMCG_DELAY_PRECISION_SHIFT
;
2480 penalty_jiffies
>>= MEMCG_DELAY_SCALING_SHIFT
;
2483 * Factor in the task's own contribution to the overage, such that four
2484 * N-sized allocations are throttled approximately the same as one
2485 * 4N-sized allocation.
2487 * MEMCG_CHARGE_BATCH pages is nominal, so work out how much smaller or
2488 * larger the current charge patch is than that.
2490 penalty_jiffies
= penalty_jiffies
* nr_pages
/ MEMCG_CHARGE_BATCH
;
2493 * Clamp the max delay per usermode return so as to still keep the
2494 * application moving forwards and also permit diagnostics, albeit
2497 return min(penalty_jiffies
, MEMCG_MAX_HIGH_DELAY_JIFFIES
);
2501 * Scheduled by try_charge() to be executed from the userland return path
2502 * and reclaims memory over the high limit.
2504 void mem_cgroup_handle_over_high(void)
2506 unsigned long penalty_jiffies
;
2507 unsigned long pflags
;
2508 unsigned int nr_pages
= current
->memcg_nr_pages_over_high
;
2509 struct mem_cgroup
*memcg
;
2511 if (likely(!nr_pages
))
2514 memcg
= get_mem_cgroup_from_mm(current
->mm
);
2515 reclaim_high(memcg
, nr_pages
, GFP_KERNEL
);
2516 current
->memcg_nr_pages_over_high
= 0;
2519 * memory.high is breached and reclaim is unable to keep up. Throttle
2520 * allocators proactively to slow down excessive growth.
2522 penalty_jiffies
= calculate_high_delay(memcg
, nr_pages
);
2525 * Don't sleep if the amount of jiffies this memcg owes us is so low
2526 * that it's not even worth doing, in an attempt to be nice to those who
2527 * go only a small amount over their memory.high value and maybe haven't
2528 * been aggressively reclaimed enough yet.
2530 if (penalty_jiffies
<= HZ
/ 100)
2534 * If we exit early, we're guaranteed to die (since
2535 * schedule_timeout_killable sets TASK_KILLABLE). This means we don't
2536 * need to account for any ill-begotten jiffies to pay them off later.
2538 psi_memstall_enter(&pflags
);
2539 schedule_timeout_killable(penalty_jiffies
);
2540 psi_memstall_leave(&pflags
);
2543 css_put(&memcg
->css
);
2546 static int try_charge(struct mem_cgroup
*memcg
, gfp_t gfp_mask
,
2547 unsigned int nr_pages
)
2549 unsigned int batch
= max(MEMCG_CHARGE_BATCH
, nr_pages
);
2550 int nr_retries
= MEM_CGROUP_RECLAIM_RETRIES
;
2551 struct mem_cgroup
*mem_over_limit
;
2552 struct page_counter
*counter
;
2553 unsigned long nr_reclaimed
;
2554 bool may_swap
= true;
2555 bool drained
= false;
2556 enum oom_status oom_status
;
2558 if (mem_cgroup_is_root(memcg
))
2561 if (consume_stock(memcg
, nr_pages
))
2564 if (!do_memsw_account() ||
2565 page_counter_try_charge(&memcg
->memsw
, batch
, &counter
)) {
2566 if (page_counter_try_charge(&memcg
->memory
, batch
, &counter
))
2568 if (do_memsw_account())
2569 page_counter_uncharge(&memcg
->memsw
, batch
);
2570 mem_over_limit
= mem_cgroup_from_counter(counter
, memory
);
2572 mem_over_limit
= mem_cgroup_from_counter(counter
, memsw
);
2576 if (batch
> nr_pages
) {
2582 * Memcg doesn't have a dedicated reserve for atomic
2583 * allocations. But like the global atomic pool, we need to
2584 * put the burden of reclaim on regular allocation requests
2585 * and let these go through as privileged allocations.
2587 if (gfp_mask
& __GFP_ATOMIC
)
2591 * Unlike in global OOM situations, memcg is not in a physical
2592 * memory shortage. Allow dying and OOM-killed tasks to
2593 * bypass the last charges so that they can exit quickly and
2594 * free their memory.
2596 if (unlikely(should_force_charge()))
2600 * Prevent unbounded recursion when reclaim operations need to
2601 * allocate memory. This might exceed the limits temporarily,
2602 * but we prefer facilitating memory reclaim and getting back
2603 * under the limit over triggering OOM kills in these cases.
2605 if (unlikely(current
->flags
& PF_MEMALLOC
))
2608 if (unlikely(task_in_memcg_oom(current
)))
2611 if (!gfpflags_allow_blocking(gfp_mask
))
2614 memcg_memory_event(mem_over_limit
, MEMCG_MAX
);
2616 nr_reclaimed
= try_to_free_mem_cgroup_pages(mem_over_limit
, nr_pages
,
2617 gfp_mask
, may_swap
);
2619 if (mem_cgroup_margin(mem_over_limit
) >= nr_pages
)
2623 drain_all_stock(mem_over_limit
);
2628 if (gfp_mask
& __GFP_NORETRY
)
2631 * Even though the limit is exceeded at this point, reclaim
2632 * may have been able to free some pages. Retry the charge
2633 * before killing the task.
2635 * Only for regular pages, though: huge pages are rather
2636 * unlikely to succeed so close to the limit, and we fall back
2637 * to regular pages anyway in case of failure.
2639 if (nr_reclaimed
&& nr_pages
<= (1 << PAGE_ALLOC_COSTLY_ORDER
))
2642 * At task move, charge accounts can be doubly counted. So, it's
2643 * better to wait until the end of task_move if something is going on.
2645 if (mem_cgroup_wait_acct_move(mem_over_limit
))
2651 if (gfp_mask
& __GFP_RETRY_MAYFAIL
)
2654 if (gfp_mask
& __GFP_NOFAIL
)
2657 if (fatal_signal_pending(current
))
2661 * keep retrying as long as the memcg oom killer is able to make
2662 * a forward progress or bypass the charge if the oom killer
2663 * couldn't make any progress.
2665 oom_status
= mem_cgroup_oom(mem_over_limit
, gfp_mask
,
2666 get_order(nr_pages
* PAGE_SIZE
));
2667 switch (oom_status
) {
2669 nr_retries
= MEM_CGROUP_RECLAIM_RETRIES
;
2677 if (!(gfp_mask
& __GFP_NOFAIL
))
2681 * The allocation either can't fail or will lead to more memory
2682 * being freed very soon. Allow memory usage go over the limit
2683 * temporarily by force charging it.
2685 page_counter_charge(&memcg
->memory
, nr_pages
);
2686 if (do_memsw_account())
2687 page_counter_charge(&memcg
->memsw
, nr_pages
);
2688 css_get_many(&memcg
->css
, nr_pages
);
2693 css_get_many(&memcg
->css
, batch
);
2694 if (batch
> nr_pages
)
2695 refill_stock(memcg
, batch
- nr_pages
);
2698 * If the hierarchy is above the normal consumption range, schedule
2699 * reclaim on returning to userland. We can perform reclaim here
2700 * if __GFP_RECLAIM but let's always punt for simplicity and so that
2701 * GFP_KERNEL can consistently be used during reclaim. @memcg is
2702 * not recorded as it most likely matches current's and won't
2703 * change in the meantime. As high limit is checked again before
2704 * reclaim, the cost of mismatch is negligible.
2707 if (page_counter_read(&memcg
->memory
) > memcg
->high
) {
2708 /* Don't bother a random interrupted task */
2709 if (in_interrupt()) {
2710 schedule_work(&memcg
->high_work
);
2713 current
->memcg_nr_pages_over_high
+= batch
;
2714 set_notify_resume(current
);
2717 } while ((memcg
= parent_mem_cgroup(memcg
)));
2722 static void cancel_charge(struct mem_cgroup
*memcg
, unsigned int nr_pages
)
2724 if (mem_cgroup_is_root(memcg
))
2727 page_counter_uncharge(&memcg
->memory
, nr_pages
);
2728 if (do_memsw_account())
2729 page_counter_uncharge(&memcg
->memsw
, nr_pages
);
2731 css_put_many(&memcg
->css
, nr_pages
);
2734 static void lock_page_lru(struct page
*page
, int *isolated
)
2736 pg_data_t
*pgdat
= page_pgdat(page
);
2738 spin_lock_irq(&pgdat
->lru_lock
);
2739 if (PageLRU(page
)) {
2740 struct lruvec
*lruvec
;
2742 lruvec
= mem_cgroup_page_lruvec(page
, pgdat
);
2744 del_page_from_lru_list(page
, lruvec
, page_lru(page
));
2750 static void unlock_page_lru(struct page
*page
, int isolated
)
2752 pg_data_t
*pgdat
= page_pgdat(page
);
2755 struct lruvec
*lruvec
;
2757 lruvec
= mem_cgroup_page_lruvec(page
, pgdat
);
2758 VM_BUG_ON_PAGE(PageLRU(page
), page
);
2760 add_page_to_lru_list(page
, lruvec
, page_lru(page
));
2762 spin_unlock_irq(&pgdat
->lru_lock
);
2765 static void commit_charge(struct page
*page
, struct mem_cgroup
*memcg
,
2770 VM_BUG_ON_PAGE(page
->mem_cgroup
, page
);
2773 * In some cases, SwapCache and FUSE(splice_buf->radixtree), the page
2774 * may already be on some other mem_cgroup's LRU. Take care of it.
2777 lock_page_lru(page
, &isolated
);
2780 * Nobody should be changing or seriously looking at
2781 * page->mem_cgroup at this point:
2783 * - the page is uncharged
2785 * - the page is off-LRU
2787 * - an anonymous fault has exclusive page access, except for
2788 * a locked page table
2790 * - a page cache insertion, a swapin fault, or a migration
2791 * have the page locked
2793 page
->mem_cgroup
= memcg
;
2796 unlock_page_lru(page
, isolated
);
2799 #ifdef CONFIG_MEMCG_KMEM
2801 * Returns a pointer to the memory cgroup to which the kernel object is charged.
2803 * The caller must ensure the memcg lifetime, e.g. by taking rcu_read_lock(),
2804 * cgroup_mutex, etc.
2806 struct mem_cgroup
*mem_cgroup_from_obj(void *p
)
2810 if (mem_cgroup_disabled())
2813 page
= virt_to_head_page(p
);
2816 * Slab pages don't have page->mem_cgroup set because corresponding
2817 * kmem caches can be reparented during the lifetime. That's why
2818 * memcg_from_slab_page() should be used instead.
2821 return memcg_from_slab_page(page
);
2823 /* All other pages use page->mem_cgroup */
2824 return page
->mem_cgroup
;
2827 static int memcg_alloc_cache_id(void)
2832 id
= ida_simple_get(&memcg_cache_ida
,
2833 0, MEMCG_CACHES_MAX_SIZE
, GFP_KERNEL
);
2837 if (id
< memcg_nr_cache_ids
)
2841 * There's no space for the new id in memcg_caches arrays,
2842 * so we have to grow them.
2844 down_write(&memcg_cache_ids_sem
);
2846 size
= 2 * (id
+ 1);
2847 if (size
< MEMCG_CACHES_MIN_SIZE
)
2848 size
= MEMCG_CACHES_MIN_SIZE
;
2849 else if (size
> MEMCG_CACHES_MAX_SIZE
)
2850 size
= MEMCG_CACHES_MAX_SIZE
;
2852 err
= memcg_update_all_caches(size
);
2854 err
= memcg_update_all_list_lrus(size
);
2856 memcg_nr_cache_ids
= size
;
2858 up_write(&memcg_cache_ids_sem
);
2861 ida_simple_remove(&memcg_cache_ida
, id
);
2867 static void memcg_free_cache_id(int id
)
2869 ida_simple_remove(&memcg_cache_ida
, id
);
2872 struct memcg_kmem_cache_create_work
{
2873 struct mem_cgroup
*memcg
;
2874 struct kmem_cache
*cachep
;
2875 struct work_struct work
;
2878 static void memcg_kmem_cache_create_func(struct work_struct
*w
)
2880 struct memcg_kmem_cache_create_work
*cw
=
2881 container_of(w
, struct memcg_kmem_cache_create_work
, work
);
2882 struct mem_cgroup
*memcg
= cw
->memcg
;
2883 struct kmem_cache
*cachep
= cw
->cachep
;
2885 memcg_create_kmem_cache(memcg
, cachep
);
2887 css_put(&memcg
->css
);
2892 * Enqueue the creation of a per-memcg kmem_cache.
2894 static void memcg_schedule_kmem_cache_create(struct mem_cgroup
*memcg
,
2895 struct kmem_cache
*cachep
)
2897 struct memcg_kmem_cache_create_work
*cw
;
2899 if (!css_tryget_online(&memcg
->css
))
2902 cw
= kmalloc(sizeof(*cw
), GFP_NOWAIT
| __GFP_NOWARN
);
2904 css_put(&memcg
->css
);
2909 cw
->cachep
= cachep
;
2910 INIT_WORK(&cw
->work
, memcg_kmem_cache_create_func
);
2912 queue_work(memcg_kmem_cache_wq
, &cw
->work
);
2915 static inline bool memcg_kmem_bypass(void)
2917 if (in_interrupt() || !current
->mm
|| (current
->flags
& PF_KTHREAD
))
2923 * memcg_kmem_get_cache: select the correct per-memcg cache for allocation
2924 * @cachep: the original global kmem cache
2926 * Return the kmem_cache we're supposed to use for a slab allocation.
2927 * We try to use the current memcg's version of the cache.
2929 * If the cache does not exist yet, if we are the first user of it, we
2930 * create it asynchronously in a workqueue and let the current allocation
2931 * go through with the original cache.
2933 * This function takes a reference to the cache it returns to assure it
2934 * won't get destroyed while we are working with it. Once the caller is
2935 * done with it, memcg_kmem_put_cache() must be called to release the
2938 struct kmem_cache
*memcg_kmem_get_cache(struct kmem_cache
*cachep
)
2940 struct mem_cgroup
*memcg
;
2941 struct kmem_cache
*memcg_cachep
;
2942 struct memcg_cache_array
*arr
;
2945 VM_BUG_ON(!is_root_cache(cachep
));
2947 if (memcg_kmem_bypass())
2952 if (unlikely(current
->active_memcg
))
2953 memcg
= current
->active_memcg
;
2955 memcg
= mem_cgroup_from_task(current
);
2957 if (!memcg
|| memcg
== root_mem_cgroup
)
2960 kmemcg_id
= READ_ONCE(memcg
->kmemcg_id
);
2964 arr
= rcu_dereference(cachep
->memcg_params
.memcg_caches
);
2967 * Make sure we will access the up-to-date value. The code updating
2968 * memcg_caches issues a write barrier to match the data dependency
2969 * barrier inside READ_ONCE() (see memcg_create_kmem_cache()).
2971 memcg_cachep
= READ_ONCE(arr
->entries
[kmemcg_id
]);
2974 * If we are in a safe context (can wait, and not in interrupt
2975 * context), we could be be predictable and return right away.
2976 * This would guarantee that the allocation being performed
2977 * already belongs in the new cache.
2979 * However, there are some clashes that can arrive from locking.
2980 * For instance, because we acquire the slab_mutex while doing
2981 * memcg_create_kmem_cache, this means no further allocation
2982 * could happen with the slab_mutex held. So it's better to
2985 * If the memcg is dying or memcg_cache is about to be released,
2986 * don't bother creating new kmem_caches. Because memcg_cachep
2987 * is ZEROed as the fist step of kmem offlining, we don't need
2988 * percpu_ref_tryget_live() here. css_tryget_online() check in
2989 * memcg_schedule_kmem_cache_create() will prevent us from
2990 * creation of a new kmem_cache.
2992 if (unlikely(!memcg_cachep
))
2993 memcg_schedule_kmem_cache_create(memcg
, cachep
);
2994 else if (percpu_ref_tryget(&memcg_cachep
->memcg_params
.refcnt
))
2995 cachep
= memcg_cachep
;
3002 * memcg_kmem_put_cache: drop reference taken by memcg_kmem_get_cache
3003 * @cachep: the cache returned by memcg_kmem_get_cache
3005 void memcg_kmem_put_cache(struct kmem_cache
*cachep
)
3007 if (!is_root_cache(cachep
))
3008 percpu_ref_put(&cachep
->memcg_params
.refcnt
);
3012 * __memcg_kmem_charge_memcg: charge a kmem page
3013 * @page: page to charge
3014 * @gfp: reclaim mode
3015 * @order: allocation order
3016 * @memcg: memory cgroup to charge
3018 * Returns 0 on success, an error code on failure.
3020 int __memcg_kmem_charge_memcg(struct page
*page
, gfp_t gfp
, int order
,
3021 struct mem_cgroup
*memcg
)
3023 unsigned int nr_pages
= 1 << order
;
3024 struct page_counter
*counter
;
3027 ret
= try_charge(memcg
, gfp
, nr_pages
);
3031 if (!cgroup_subsys_on_dfl(memory_cgrp_subsys
) &&
3032 !page_counter_try_charge(&memcg
->kmem
, nr_pages
, &counter
)) {
3035 * Enforce __GFP_NOFAIL allocation because callers are not
3036 * prepared to see failures and likely do not have any failure
3039 if (gfp
& __GFP_NOFAIL
) {
3040 page_counter_charge(&memcg
->kmem
, nr_pages
);
3043 cancel_charge(memcg
, nr_pages
);
3050 * __memcg_kmem_charge: charge a kmem page to the current memory cgroup
3051 * @page: page to charge
3052 * @gfp: reclaim mode
3053 * @order: allocation order
3055 * Returns 0 on success, an error code on failure.
3057 int __memcg_kmem_charge(struct page
*page
, gfp_t gfp
, int order
)
3059 struct mem_cgroup
*memcg
;
3062 if (memcg_kmem_bypass())
3065 memcg
= get_mem_cgroup_from_current();
3066 if (!mem_cgroup_is_root(memcg
)) {
3067 ret
= __memcg_kmem_charge_memcg(page
, gfp
, order
, memcg
);
3069 page
->mem_cgroup
= memcg
;
3070 __SetPageKmemcg(page
);
3073 css_put(&memcg
->css
);
3078 * __memcg_kmem_uncharge_memcg: uncharge a kmem page
3079 * @memcg: memcg to uncharge
3080 * @nr_pages: number of pages to uncharge
3082 void __memcg_kmem_uncharge_memcg(struct mem_cgroup
*memcg
,
3083 unsigned int nr_pages
)
3085 if (!cgroup_subsys_on_dfl(memory_cgrp_subsys
))
3086 page_counter_uncharge(&memcg
->kmem
, nr_pages
);
3088 page_counter_uncharge(&memcg
->memory
, nr_pages
);
3089 if (do_memsw_account())
3090 page_counter_uncharge(&memcg
->memsw
, nr_pages
);
3093 * __memcg_kmem_uncharge: uncharge a kmem page
3094 * @page: page to uncharge
3095 * @order: allocation order
3097 void __memcg_kmem_uncharge(struct page
*page
, int order
)
3099 struct mem_cgroup
*memcg
= page
->mem_cgroup
;
3100 unsigned int nr_pages
= 1 << order
;
3105 VM_BUG_ON_PAGE(mem_cgroup_is_root(memcg
), page
);
3106 __memcg_kmem_uncharge_memcg(memcg
, nr_pages
);
3107 page
->mem_cgroup
= NULL
;
3109 /* slab pages do not have PageKmemcg flag set */
3110 if (PageKmemcg(page
))
3111 __ClearPageKmemcg(page
);
3113 css_put_many(&memcg
->css
, nr_pages
);
3115 #endif /* CONFIG_MEMCG_KMEM */
3117 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
3120 * Because tail pages are not marked as "used", set it. We're under
3121 * pgdat->lru_lock and migration entries setup in all page mappings.
3123 void mem_cgroup_split_huge_fixup(struct page
*head
)
3127 if (mem_cgroup_disabled())
3130 for (i
= 1; i
< HPAGE_PMD_NR
; i
++)
3131 head
[i
].mem_cgroup
= head
->mem_cgroup
;
3133 __mod_memcg_state(head
->mem_cgroup
, MEMCG_RSS_HUGE
, -HPAGE_PMD_NR
);
3135 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
3137 #ifdef CONFIG_MEMCG_SWAP
3139 * mem_cgroup_move_swap_account - move swap charge and swap_cgroup's record.
3140 * @entry: swap entry to be moved
3141 * @from: mem_cgroup which the entry is moved from
3142 * @to: mem_cgroup which the entry is moved to
3144 * It succeeds only when the swap_cgroup's record for this entry is the same
3145 * as the mem_cgroup's id of @from.
3147 * Returns 0 on success, -EINVAL on failure.
3149 * The caller must have charged to @to, IOW, called page_counter_charge() about
3150 * both res and memsw, and called css_get().
3152 static int mem_cgroup_move_swap_account(swp_entry_t entry
,
3153 struct mem_cgroup
*from
, struct mem_cgroup
*to
)
3155 unsigned short old_id
, new_id
;
3157 old_id
= mem_cgroup_id(from
);
3158 new_id
= mem_cgroup_id(to
);
3160 if (swap_cgroup_cmpxchg(entry
, old_id
, new_id
) == old_id
) {
3161 mod_memcg_state(from
, MEMCG_SWAP
, -1);
3162 mod_memcg_state(to
, MEMCG_SWAP
, 1);
3168 static inline int mem_cgroup_move_swap_account(swp_entry_t entry
,
3169 struct mem_cgroup
*from
, struct mem_cgroup
*to
)
3175 static DEFINE_MUTEX(memcg_max_mutex
);
3177 static int mem_cgroup_resize_max(struct mem_cgroup
*memcg
,
3178 unsigned long max
, bool memsw
)
3180 bool enlarge
= false;
3181 bool drained
= false;
3183 bool limits_invariant
;
3184 struct page_counter
*counter
= memsw
? &memcg
->memsw
: &memcg
->memory
;
3187 if (signal_pending(current
)) {
3192 mutex_lock(&memcg_max_mutex
);
3194 * Make sure that the new limit (memsw or memory limit) doesn't
3195 * break our basic invariant rule memory.max <= memsw.max.
3197 limits_invariant
= memsw
? max
>= memcg
->memory
.max
:
3198 max
<= memcg
->memsw
.max
;
3199 if (!limits_invariant
) {
3200 mutex_unlock(&memcg_max_mutex
);
3204 if (max
> counter
->max
)
3206 ret
= page_counter_set_max(counter
, max
);
3207 mutex_unlock(&memcg_max_mutex
);
3213 drain_all_stock(memcg
);
3218 if (!try_to_free_mem_cgroup_pages(memcg
, 1,
3219 GFP_KERNEL
, !memsw
)) {
3225 if (!ret
&& enlarge
)
3226 memcg_oom_recover(memcg
);
3231 unsigned long mem_cgroup_soft_limit_reclaim(pg_data_t
*pgdat
, int order
,
3233 unsigned long *total_scanned
)
3235 unsigned long nr_reclaimed
= 0;
3236 struct mem_cgroup_per_node
*mz
, *next_mz
= NULL
;
3237 unsigned long reclaimed
;
3239 struct mem_cgroup_tree_per_node
*mctz
;
3240 unsigned long excess
;
3241 unsigned long nr_scanned
;
3246 mctz
= soft_limit_tree_node(pgdat
->node_id
);
3249 * Do not even bother to check the largest node if the root
3250 * is empty. Do it lockless to prevent lock bouncing. Races
3251 * are acceptable as soft limit is best effort anyway.
3253 if (!mctz
|| RB_EMPTY_ROOT(&mctz
->rb_root
))
3257 * This loop can run a while, specially if mem_cgroup's continuously
3258 * keep exceeding their soft limit and putting the system under
3265 mz
= mem_cgroup_largest_soft_limit_node(mctz
);
3270 reclaimed
= mem_cgroup_soft_reclaim(mz
->memcg
, pgdat
,
3271 gfp_mask
, &nr_scanned
);
3272 nr_reclaimed
+= reclaimed
;
3273 *total_scanned
+= nr_scanned
;
3274 spin_lock_irq(&mctz
->lock
);
3275 __mem_cgroup_remove_exceeded(mz
, mctz
);
3278 * If we failed to reclaim anything from this memory cgroup
3279 * it is time to move on to the next cgroup
3283 next_mz
= __mem_cgroup_largest_soft_limit_node(mctz
);
3285 excess
= soft_limit_excess(mz
->memcg
);
3287 * One school of thought says that we should not add
3288 * back the node to the tree if reclaim returns 0.
3289 * But our reclaim could return 0, simply because due
3290 * to priority we are exposing a smaller subset of
3291 * memory to reclaim from. Consider this as a longer
3294 /* If excess == 0, no tree ops */
3295 __mem_cgroup_insert_exceeded(mz
, mctz
, excess
);
3296 spin_unlock_irq(&mctz
->lock
);
3297 css_put(&mz
->memcg
->css
);
3300 * Could not reclaim anything and there are no more
3301 * mem cgroups to try or we seem to be looping without
3302 * reclaiming anything.
3304 if (!nr_reclaimed
&&
3306 loop
> MEM_CGROUP_MAX_SOFT_LIMIT_RECLAIM_LOOPS
))
3308 } while (!nr_reclaimed
);
3310 css_put(&next_mz
->memcg
->css
);
3311 return nr_reclaimed
;
3315 * Test whether @memcg has children, dead or alive. Note that this
3316 * function doesn't care whether @memcg has use_hierarchy enabled and
3317 * returns %true if there are child csses according to the cgroup
3318 * hierarchy. Testing use_hierarchy is the caller's responsiblity.
3320 static inline bool memcg_has_children(struct mem_cgroup
*memcg
)
3325 ret
= css_next_child(NULL
, &memcg
->css
);
3331 * Reclaims as many pages from the given memcg as possible.
3333 * Caller is responsible for holding css reference for memcg.
3335 static int mem_cgroup_force_empty(struct mem_cgroup
*memcg
)
3337 int nr_retries
= MEM_CGROUP_RECLAIM_RETRIES
;
3339 /* we call try-to-free pages for make this cgroup empty */
3340 lru_add_drain_all();
3342 drain_all_stock(memcg
);
3344 /* try to free all pages in this cgroup */
3345 while (nr_retries
&& page_counter_read(&memcg
->memory
)) {
3348 if (signal_pending(current
))
3351 progress
= try_to_free_mem_cgroup_pages(memcg
, 1,
3355 /* maybe some writeback is necessary */
3356 congestion_wait(BLK_RW_ASYNC
, HZ
/10);
3364 static ssize_t
mem_cgroup_force_empty_write(struct kernfs_open_file
*of
,
3365 char *buf
, size_t nbytes
,
3368 struct mem_cgroup
*memcg
= mem_cgroup_from_css(of_css(of
));
3370 if (mem_cgroup_is_root(memcg
))
3372 return mem_cgroup_force_empty(memcg
) ?: nbytes
;
3375 static u64
mem_cgroup_hierarchy_read(struct cgroup_subsys_state
*css
,
3378 return mem_cgroup_from_css(css
)->use_hierarchy
;
3381 static int mem_cgroup_hierarchy_write(struct cgroup_subsys_state
*css
,
3382 struct cftype
*cft
, u64 val
)
3385 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
3386 struct mem_cgroup
*parent_memcg
= mem_cgroup_from_css(memcg
->css
.parent
);
3388 if (memcg
->use_hierarchy
== val
)
3392 * If parent's use_hierarchy is set, we can't make any modifications
3393 * in the child subtrees. If it is unset, then the change can
3394 * occur, provided the current cgroup has no children.
3396 * For the root cgroup, parent_mem is NULL, we allow value to be
3397 * set if there are no children.
3399 if ((!parent_memcg
|| !parent_memcg
->use_hierarchy
) &&
3400 (val
== 1 || val
== 0)) {
3401 if (!memcg_has_children(memcg
))
3402 memcg
->use_hierarchy
= val
;
3411 static unsigned long mem_cgroup_usage(struct mem_cgroup
*memcg
, bool swap
)
3415 if (mem_cgroup_is_root(memcg
)) {
3416 val
= memcg_page_state(memcg
, MEMCG_CACHE
) +
3417 memcg_page_state(memcg
, MEMCG_RSS
);
3419 val
+= memcg_page_state(memcg
, MEMCG_SWAP
);
3422 val
= page_counter_read(&memcg
->memory
);
3424 val
= page_counter_read(&memcg
->memsw
);
3437 static u64
mem_cgroup_read_u64(struct cgroup_subsys_state
*css
,
3440 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
3441 struct page_counter
*counter
;
3443 switch (MEMFILE_TYPE(cft
->private)) {
3445 counter
= &memcg
->memory
;
3448 counter
= &memcg
->memsw
;
3451 counter
= &memcg
->kmem
;
3454 counter
= &memcg
->tcpmem
;
3460 switch (MEMFILE_ATTR(cft
->private)) {
3462 if (counter
== &memcg
->memory
)
3463 return (u64
)mem_cgroup_usage(memcg
, false) * PAGE_SIZE
;
3464 if (counter
== &memcg
->memsw
)
3465 return (u64
)mem_cgroup_usage(memcg
, true) * PAGE_SIZE
;
3466 return (u64
)page_counter_read(counter
) * PAGE_SIZE
;
3468 return (u64
)counter
->max
* PAGE_SIZE
;
3470 return (u64
)counter
->watermark
* PAGE_SIZE
;
3472 return counter
->failcnt
;
3473 case RES_SOFT_LIMIT
:
3474 return (u64
)memcg
->soft_limit
* PAGE_SIZE
;
3480 static void memcg_flush_percpu_vmstats(struct mem_cgroup
*memcg
)
3482 unsigned long stat
[MEMCG_NR_STAT
] = {0};
3483 struct mem_cgroup
*mi
;
3486 for_each_online_cpu(cpu
)
3487 for (i
= 0; i
< MEMCG_NR_STAT
; i
++)
3488 stat
[i
] += per_cpu(memcg
->vmstats_percpu
->stat
[i
], cpu
);
3490 for (mi
= memcg
; mi
; mi
= parent_mem_cgroup(mi
))
3491 for (i
= 0; i
< MEMCG_NR_STAT
; i
++)
3492 atomic_long_add(stat
[i
], &mi
->vmstats
[i
]);
3494 for_each_node(node
) {
3495 struct mem_cgroup_per_node
*pn
= memcg
->nodeinfo
[node
];
3496 struct mem_cgroup_per_node
*pi
;
3498 for (i
= 0; i
< NR_VM_NODE_STAT_ITEMS
; i
++)
3501 for_each_online_cpu(cpu
)
3502 for (i
= 0; i
< NR_VM_NODE_STAT_ITEMS
; i
++)
3504 pn
->lruvec_stat_cpu
->count
[i
], cpu
);
3506 for (pi
= pn
; pi
; pi
= parent_nodeinfo(pi
, node
))
3507 for (i
= 0; i
< NR_VM_NODE_STAT_ITEMS
; i
++)
3508 atomic_long_add(stat
[i
], &pi
->lruvec_stat
[i
]);
3512 static void memcg_flush_percpu_vmevents(struct mem_cgroup
*memcg
)
3514 unsigned long events
[NR_VM_EVENT_ITEMS
];
3515 struct mem_cgroup
*mi
;
3518 for (i
= 0; i
< NR_VM_EVENT_ITEMS
; i
++)
3521 for_each_online_cpu(cpu
)
3522 for (i
= 0; i
< NR_VM_EVENT_ITEMS
; i
++)
3523 events
[i
] += per_cpu(memcg
->vmstats_percpu
->events
[i
],
3526 for (mi
= memcg
; mi
; mi
= parent_mem_cgroup(mi
))
3527 for (i
= 0; i
< NR_VM_EVENT_ITEMS
; i
++)
3528 atomic_long_add(events
[i
], &mi
->vmevents
[i
]);
3531 #ifdef CONFIG_MEMCG_KMEM
3532 static int memcg_online_kmem(struct mem_cgroup
*memcg
)
3536 if (cgroup_memory_nokmem
)
3539 BUG_ON(memcg
->kmemcg_id
>= 0);
3540 BUG_ON(memcg
->kmem_state
);
3542 memcg_id
= memcg_alloc_cache_id();
3546 static_branch_inc(&memcg_kmem_enabled_key
);
3548 * A memory cgroup is considered kmem-online as soon as it gets
3549 * kmemcg_id. Setting the id after enabling static branching will
3550 * guarantee no one starts accounting before all call sites are
3553 memcg
->kmemcg_id
= memcg_id
;
3554 memcg
->kmem_state
= KMEM_ONLINE
;
3555 INIT_LIST_HEAD(&memcg
->kmem_caches
);
3560 static void memcg_offline_kmem(struct mem_cgroup
*memcg
)
3562 struct cgroup_subsys_state
*css
;
3563 struct mem_cgroup
*parent
, *child
;
3566 if (memcg
->kmem_state
!= KMEM_ONLINE
)
3569 * Clear the online state before clearing memcg_caches array
3570 * entries. The slab_mutex in memcg_deactivate_kmem_caches()
3571 * guarantees that no cache will be created for this cgroup
3572 * after we are done (see memcg_create_kmem_cache()).
3574 memcg
->kmem_state
= KMEM_ALLOCATED
;
3576 parent
= parent_mem_cgroup(memcg
);
3578 parent
= root_mem_cgroup
;
3581 * Deactivate and reparent kmem_caches.
3583 memcg_deactivate_kmem_caches(memcg
, parent
);
3585 kmemcg_id
= memcg
->kmemcg_id
;
3586 BUG_ON(kmemcg_id
< 0);
3589 * Change kmemcg_id of this cgroup and all its descendants to the
3590 * parent's id, and then move all entries from this cgroup's list_lrus
3591 * to ones of the parent. After we have finished, all list_lrus
3592 * corresponding to this cgroup are guaranteed to remain empty. The
3593 * ordering is imposed by list_lru_node->lock taken by
3594 * memcg_drain_all_list_lrus().
3596 rcu_read_lock(); /* can be called from css_free w/o cgroup_mutex */
3597 css_for_each_descendant_pre(css
, &memcg
->css
) {
3598 child
= mem_cgroup_from_css(css
);
3599 BUG_ON(child
->kmemcg_id
!= kmemcg_id
);
3600 child
->kmemcg_id
= parent
->kmemcg_id
;
3601 if (!memcg
->use_hierarchy
)
3606 memcg_drain_all_list_lrus(kmemcg_id
, parent
);
3608 memcg_free_cache_id(kmemcg_id
);
3611 static void memcg_free_kmem(struct mem_cgroup
*memcg
)
3613 /* css_alloc() failed, offlining didn't happen */
3614 if (unlikely(memcg
->kmem_state
== KMEM_ONLINE
))
3615 memcg_offline_kmem(memcg
);
3617 if (memcg
->kmem_state
== KMEM_ALLOCATED
) {
3618 WARN_ON(!list_empty(&memcg
->kmem_caches
));
3619 static_branch_dec(&memcg_kmem_enabled_key
);
3623 static int memcg_online_kmem(struct mem_cgroup
*memcg
)
3627 static void memcg_offline_kmem(struct mem_cgroup
*memcg
)
3630 static void memcg_free_kmem(struct mem_cgroup
*memcg
)
3633 #endif /* CONFIG_MEMCG_KMEM */
3635 static int memcg_update_kmem_max(struct mem_cgroup
*memcg
,
3640 mutex_lock(&memcg_max_mutex
);
3641 ret
= page_counter_set_max(&memcg
->kmem
, max
);
3642 mutex_unlock(&memcg_max_mutex
);
3646 static int memcg_update_tcp_max(struct mem_cgroup
*memcg
, unsigned long max
)
3650 mutex_lock(&memcg_max_mutex
);
3652 ret
= page_counter_set_max(&memcg
->tcpmem
, max
);
3656 if (!memcg
->tcpmem_active
) {
3658 * The active flag needs to be written after the static_key
3659 * update. This is what guarantees that the socket activation
3660 * function is the last one to run. See mem_cgroup_sk_alloc()
3661 * for details, and note that we don't mark any socket as
3662 * belonging to this memcg until that flag is up.
3664 * We need to do this, because static_keys will span multiple
3665 * sites, but we can't control their order. If we mark a socket
3666 * as accounted, but the accounting functions are not patched in
3667 * yet, we'll lose accounting.
3669 * We never race with the readers in mem_cgroup_sk_alloc(),
3670 * because when this value change, the code to process it is not
3673 static_branch_inc(&memcg_sockets_enabled_key
);
3674 memcg
->tcpmem_active
= true;
3677 mutex_unlock(&memcg_max_mutex
);
3682 * The user of this function is...
3685 static ssize_t
mem_cgroup_write(struct kernfs_open_file
*of
,
3686 char *buf
, size_t nbytes
, loff_t off
)
3688 struct mem_cgroup
*memcg
= mem_cgroup_from_css(of_css(of
));
3689 unsigned long nr_pages
;
3692 buf
= strstrip(buf
);
3693 ret
= page_counter_memparse(buf
, "-1", &nr_pages
);
3697 switch (MEMFILE_ATTR(of_cft(of
)->private)) {
3699 if (mem_cgroup_is_root(memcg
)) { /* Can't set limit on root */
3703 switch (MEMFILE_TYPE(of_cft(of
)->private)) {
3705 ret
= mem_cgroup_resize_max(memcg
, nr_pages
, false);
3708 ret
= mem_cgroup_resize_max(memcg
, nr_pages
, true);
3711 pr_warn_once("kmem.limit_in_bytes is deprecated and will be removed. "
3712 "Please report your usecase to linux-mm@kvack.org if you "
3713 "depend on this functionality.\n");
3714 ret
= memcg_update_kmem_max(memcg
, nr_pages
);
3717 ret
= memcg_update_tcp_max(memcg
, nr_pages
);
3721 case RES_SOFT_LIMIT
:
3722 memcg
->soft_limit
= nr_pages
;
3726 return ret
?: nbytes
;
3729 static ssize_t
mem_cgroup_reset(struct kernfs_open_file
*of
, char *buf
,
3730 size_t nbytes
, loff_t off
)
3732 struct mem_cgroup
*memcg
= mem_cgroup_from_css(of_css(of
));
3733 struct page_counter
*counter
;
3735 switch (MEMFILE_TYPE(of_cft(of
)->private)) {
3737 counter
= &memcg
->memory
;
3740 counter
= &memcg
->memsw
;
3743 counter
= &memcg
->kmem
;
3746 counter
= &memcg
->tcpmem
;
3752 switch (MEMFILE_ATTR(of_cft(of
)->private)) {
3754 page_counter_reset_watermark(counter
);
3757 counter
->failcnt
= 0;
3766 static u64
mem_cgroup_move_charge_read(struct cgroup_subsys_state
*css
,
3769 return mem_cgroup_from_css(css
)->move_charge_at_immigrate
;
3773 static int mem_cgroup_move_charge_write(struct cgroup_subsys_state
*css
,
3774 struct cftype
*cft
, u64 val
)
3776 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
3778 if (val
& ~MOVE_MASK
)
3782 * No kind of locking is needed in here, because ->can_attach() will
3783 * check this value once in the beginning of the process, and then carry
3784 * on with stale data. This means that changes to this value will only
3785 * affect task migrations starting after the change.
3787 memcg
->move_charge_at_immigrate
= val
;
3791 static int mem_cgroup_move_charge_write(struct cgroup_subsys_state
*css
,
3792 struct cftype
*cft
, u64 val
)
3800 #define LRU_ALL_FILE (BIT(LRU_INACTIVE_FILE) | BIT(LRU_ACTIVE_FILE))
3801 #define LRU_ALL_ANON (BIT(LRU_INACTIVE_ANON) | BIT(LRU_ACTIVE_ANON))
3802 #define LRU_ALL ((1 << NR_LRU_LISTS) - 1)
3804 static unsigned long mem_cgroup_node_nr_lru_pages(struct mem_cgroup
*memcg
,
3805 int nid
, unsigned int lru_mask
)
3807 struct lruvec
*lruvec
= mem_cgroup_lruvec(NODE_DATA(nid
), memcg
);
3808 unsigned long nr
= 0;
3811 VM_BUG_ON((unsigned)nid
>= nr_node_ids
);
3814 if (!(BIT(lru
) & lru_mask
))
3816 nr
+= lruvec_page_state_local(lruvec
, NR_LRU_BASE
+ lru
);
3821 static unsigned long mem_cgroup_nr_lru_pages(struct mem_cgroup
*memcg
,
3822 unsigned int lru_mask
)
3824 unsigned long nr
= 0;
3828 if (!(BIT(lru
) & lru_mask
))
3830 nr
+= memcg_page_state_local(memcg
, NR_LRU_BASE
+ lru
);
3835 static int memcg_numa_stat_show(struct seq_file
*m
, void *v
)
3839 unsigned int lru_mask
;
3842 static const struct numa_stat stats
[] = {
3843 { "total", LRU_ALL
},
3844 { "file", LRU_ALL_FILE
},
3845 { "anon", LRU_ALL_ANON
},
3846 { "unevictable", BIT(LRU_UNEVICTABLE
) },
3848 const struct numa_stat
*stat
;
3851 struct mem_cgroup
*memcg
= mem_cgroup_from_seq(m
);
3853 for (stat
= stats
; stat
< stats
+ ARRAY_SIZE(stats
); stat
++) {
3854 nr
= mem_cgroup_nr_lru_pages(memcg
, stat
->lru_mask
);
3855 seq_printf(m
, "%s=%lu", stat
->name
, nr
);
3856 for_each_node_state(nid
, N_MEMORY
) {
3857 nr
= mem_cgroup_node_nr_lru_pages(memcg
, nid
,
3859 seq_printf(m
, " N%d=%lu", nid
, nr
);
3864 for (stat
= stats
; stat
< stats
+ ARRAY_SIZE(stats
); stat
++) {
3865 struct mem_cgroup
*iter
;
3868 for_each_mem_cgroup_tree(iter
, memcg
)
3869 nr
+= mem_cgroup_nr_lru_pages(iter
, stat
->lru_mask
);
3870 seq_printf(m
, "hierarchical_%s=%lu", stat
->name
, nr
);
3871 for_each_node_state(nid
, N_MEMORY
) {
3873 for_each_mem_cgroup_tree(iter
, memcg
)
3874 nr
+= mem_cgroup_node_nr_lru_pages(
3875 iter
, nid
, stat
->lru_mask
);
3876 seq_printf(m
, " N%d=%lu", nid
, nr
);
3883 #endif /* CONFIG_NUMA */
3885 static const unsigned int memcg1_stats
[] = {
3896 static const char *const memcg1_stat_names
[] = {
3907 /* Universal VM events cgroup1 shows, original sort order */
3908 static const unsigned int memcg1_events
[] = {
3915 static const char *const memcg1_event_names
[] = {
3922 static int memcg_stat_show(struct seq_file
*m
, void *v
)
3924 struct mem_cgroup
*memcg
= mem_cgroup_from_seq(m
);
3925 unsigned long memory
, memsw
;
3926 struct mem_cgroup
*mi
;
3929 BUILD_BUG_ON(ARRAY_SIZE(memcg1_stat_names
) != ARRAY_SIZE(memcg1_stats
));
3930 BUILD_BUG_ON(ARRAY_SIZE(mem_cgroup_lru_names
) != NR_LRU_LISTS
);
3932 for (i
= 0; i
< ARRAY_SIZE(memcg1_stats
); i
++) {
3933 if (memcg1_stats
[i
] == MEMCG_SWAP
&& !do_memsw_account())
3935 seq_printf(m
, "%s %lu\n", memcg1_stat_names
[i
],
3936 memcg_page_state_local(memcg
, memcg1_stats
[i
]) *
3940 for (i
= 0; i
< ARRAY_SIZE(memcg1_events
); i
++)
3941 seq_printf(m
, "%s %lu\n", memcg1_event_names
[i
],
3942 memcg_events_local(memcg
, memcg1_events
[i
]));
3944 for (i
= 0; i
< NR_LRU_LISTS
; i
++)
3945 seq_printf(m
, "%s %lu\n", mem_cgroup_lru_names
[i
],
3946 memcg_page_state_local(memcg
, NR_LRU_BASE
+ i
) *
3949 /* Hierarchical information */
3950 memory
= memsw
= PAGE_COUNTER_MAX
;
3951 for (mi
= memcg
; mi
; mi
= parent_mem_cgroup(mi
)) {
3952 memory
= min(memory
, mi
->memory
.max
);
3953 memsw
= min(memsw
, mi
->memsw
.max
);
3955 seq_printf(m
, "hierarchical_memory_limit %llu\n",
3956 (u64
)memory
* PAGE_SIZE
);
3957 if (do_memsw_account())
3958 seq_printf(m
, "hierarchical_memsw_limit %llu\n",
3959 (u64
)memsw
* PAGE_SIZE
);
3961 for (i
= 0; i
< ARRAY_SIZE(memcg1_stats
); i
++) {
3962 if (memcg1_stats
[i
] == MEMCG_SWAP
&& !do_memsw_account())
3964 seq_printf(m
, "total_%s %llu\n", memcg1_stat_names
[i
],
3965 (u64
)memcg_page_state(memcg
, memcg1_stats
[i
]) *
3969 for (i
= 0; i
< ARRAY_SIZE(memcg1_events
); i
++)
3970 seq_printf(m
, "total_%s %llu\n", memcg1_event_names
[i
],
3971 (u64
)memcg_events(memcg
, memcg1_events
[i
]));
3973 for (i
= 0; i
< NR_LRU_LISTS
; i
++)
3974 seq_printf(m
, "total_%s %llu\n", mem_cgroup_lru_names
[i
],
3975 (u64
)memcg_page_state(memcg
, NR_LRU_BASE
+ i
) *
3978 #ifdef CONFIG_DEBUG_VM
3981 struct mem_cgroup_per_node
*mz
;
3982 struct zone_reclaim_stat
*rstat
;
3983 unsigned long recent_rotated
[2] = {0, 0};
3984 unsigned long recent_scanned
[2] = {0, 0};
3986 for_each_online_pgdat(pgdat
) {
3987 mz
= mem_cgroup_nodeinfo(memcg
, pgdat
->node_id
);
3988 rstat
= &mz
->lruvec
.reclaim_stat
;
3990 recent_rotated
[0] += rstat
->recent_rotated
[0];
3991 recent_rotated
[1] += rstat
->recent_rotated
[1];
3992 recent_scanned
[0] += rstat
->recent_scanned
[0];
3993 recent_scanned
[1] += rstat
->recent_scanned
[1];
3995 seq_printf(m
, "recent_rotated_anon %lu\n", recent_rotated
[0]);
3996 seq_printf(m
, "recent_rotated_file %lu\n", recent_rotated
[1]);
3997 seq_printf(m
, "recent_scanned_anon %lu\n", recent_scanned
[0]);
3998 seq_printf(m
, "recent_scanned_file %lu\n", recent_scanned
[1]);
4005 static u64
mem_cgroup_swappiness_read(struct cgroup_subsys_state
*css
,
4008 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
4010 return mem_cgroup_swappiness(memcg
);
4013 static int mem_cgroup_swappiness_write(struct cgroup_subsys_state
*css
,
4014 struct cftype
*cft
, u64 val
)
4016 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
4022 memcg
->swappiness
= val
;
4024 vm_swappiness
= val
;
4029 static void __mem_cgroup_threshold(struct mem_cgroup
*memcg
, bool swap
)
4031 struct mem_cgroup_threshold_ary
*t
;
4032 unsigned long usage
;
4037 t
= rcu_dereference(memcg
->thresholds
.primary
);
4039 t
= rcu_dereference(memcg
->memsw_thresholds
.primary
);
4044 usage
= mem_cgroup_usage(memcg
, swap
);
4047 * current_threshold points to threshold just below or equal to usage.
4048 * If it's not true, a threshold was crossed after last
4049 * call of __mem_cgroup_threshold().
4051 i
= t
->current_threshold
;
4054 * Iterate backward over array of thresholds starting from
4055 * current_threshold and check if a threshold is crossed.
4056 * If none of thresholds below usage is crossed, we read
4057 * only one element of the array here.
4059 for (; i
>= 0 && unlikely(t
->entries
[i
].threshold
> usage
); i
--)
4060 eventfd_signal(t
->entries
[i
].eventfd
, 1);
4062 /* i = current_threshold + 1 */
4066 * Iterate forward over array of thresholds starting from
4067 * current_threshold+1 and check if a threshold is crossed.
4068 * If none of thresholds above usage is crossed, we read
4069 * only one element of the array here.
4071 for (; i
< t
->size
&& unlikely(t
->entries
[i
].threshold
<= usage
); i
++)
4072 eventfd_signal(t
->entries
[i
].eventfd
, 1);
4074 /* Update current_threshold */
4075 t
->current_threshold
= i
- 1;
4080 static void mem_cgroup_threshold(struct mem_cgroup
*memcg
)
4083 __mem_cgroup_threshold(memcg
, false);
4084 if (do_memsw_account())
4085 __mem_cgroup_threshold(memcg
, true);
4087 memcg
= parent_mem_cgroup(memcg
);
4091 static int compare_thresholds(const void *a
, const void *b
)
4093 const struct mem_cgroup_threshold
*_a
= a
;
4094 const struct mem_cgroup_threshold
*_b
= b
;
4096 if (_a
->threshold
> _b
->threshold
)
4099 if (_a
->threshold
< _b
->threshold
)
4105 static int mem_cgroup_oom_notify_cb(struct mem_cgroup
*memcg
)
4107 struct mem_cgroup_eventfd_list
*ev
;
4109 spin_lock(&memcg_oom_lock
);
4111 list_for_each_entry(ev
, &memcg
->oom_notify
, list
)
4112 eventfd_signal(ev
->eventfd
, 1);
4114 spin_unlock(&memcg_oom_lock
);
4118 static void mem_cgroup_oom_notify(struct mem_cgroup
*memcg
)
4120 struct mem_cgroup
*iter
;
4122 for_each_mem_cgroup_tree(iter
, memcg
)
4123 mem_cgroup_oom_notify_cb(iter
);
4126 static int __mem_cgroup_usage_register_event(struct mem_cgroup
*memcg
,
4127 struct eventfd_ctx
*eventfd
, const char *args
, enum res_type type
)
4129 struct mem_cgroup_thresholds
*thresholds
;
4130 struct mem_cgroup_threshold_ary
*new;
4131 unsigned long threshold
;
4132 unsigned long usage
;
4135 ret
= page_counter_memparse(args
, "-1", &threshold
);
4139 mutex_lock(&memcg
->thresholds_lock
);
4142 thresholds
= &memcg
->thresholds
;
4143 usage
= mem_cgroup_usage(memcg
, false);
4144 } else if (type
== _MEMSWAP
) {
4145 thresholds
= &memcg
->memsw_thresholds
;
4146 usage
= mem_cgroup_usage(memcg
, true);
4150 /* Check if a threshold crossed before adding a new one */
4151 if (thresholds
->primary
)
4152 __mem_cgroup_threshold(memcg
, type
== _MEMSWAP
);
4154 size
= thresholds
->primary
? thresholds
->primary
->size
+ 1 : 1;
4156 /* Allocate memory for new array of thresholds */
4157 new = kmalloc(struct_size(new, entries
, size
), GFP_KERNEL
);
4164 /* Copy thresholds (if any) to new array */
4165 if (thresholds
->primary
) {
4166 memcpy(new->entries
, thresholds
->primary
->entries
, (size
- 1) *
4167 sizeof(struct mem_cgroup_threshold
));
4170 /* Add new threshold */
4171 new->entries
[size
- 1].eventfd
= eventfd
;
4172 new->entries
[size
- 1].threshold
= threshold
;
4174 /* Sort thresholds. Registering of new threshold isn't time-critical */
4175 sort(new->entries
, size
, sizeof(struct mem_cgroup_threshold
),
4176 compare_thresholds
, NULL
);
4178 /* Find current threshold */
4179 new->current_threshold
= -1;
4180 for (i
= 0; i
< size
; i
++) {
4181 if (new->entries
[i
].threshold
<= usage
) {
4183 * new->current_threshold will not be used until
4184 * rcu_assign_pointer(), so it's safe to increment
4187 ++new->current_threshold
;
4192 /* Free old spare buffer and save old primary buffer as spare */
4193 kfree(thresholds
->spare
);
4194 thresholds
->spare
= thresholds
->primary
;
4196 rcu_assign_pointer(thresholds
->primary
, new);
4198 /* To be sure that nobody uses thresholds */
4202 mutex_unlock(&memcg
->thresholds_lock
);
4207 static int mem_cgroup_usage_register_event(struct mem_cgroup
*memcg
,
4208 struct eventfd_ctx
*eventfd
, const char *args
)
4210 return __mem_cgroup_usage_register_event(memcg
, eventfd
, args
, _MEM
);
4213 static int memsw_cgroup_usage_register_event(struct mem_cgroup
*memcg
,
4214 struct eventfd_ctx
*eventfd
, const char *args
)
4216 return __mem_cgroup_usage_register_event(memcg
, eventfd
, args
, _MEMSWAP
);
4219 static void __mem_cgroup_usage_unregister_event(struct mem_cgroup
*memcg
,
4220 struct eventfd_ctx
*eventfd
, enum res_type type
)
4222 struct mem_cgroup_thresholds
*thresholds
;
4223 struct mem_cgroup_threshold_ary
*new;
4224 unsigned long usage
;
4225 int i
, j
, size
, entries
;
4227 mutex_lock(&memcg
->thresholds_lock
);
4230 thresholds
= &memcg
->thresholds
;
4231 usage
= mem_cgroup_usage(memcg
, false);
4232 } else if (type
== _MEMSWAP
) {
4233 thresholds
= &memcg
->memsw_thresholds
;
4234 usage
= mem_cgroup_usage(memcg
, true);
4238 if (!thresholds
->primary
)
4241 /* Check if a threshold crossed before removing */
4242 __mem_cgroup_threshold(memcg
, type
== _MEMSWAP
);
4244 /* Calculate new number of threshold */
4246 for (i
= 0; i
< thresholds
->primary
->size
; i
++) {
4247 if (thresholds
->primary
->entries
[i
].eventfd
!= eventfd
)
4253 new = thresholds
->spare
;
4255 /* If no items related to eventfd have been cleared, nothing to do */
4259 /* Set thresholds array to NULL if we don't have thresholds */
4268 /* Copy thresholds and find current threshold */
4269 new->current_threshold
= -1;
4270 for (i
= 0, j
= 0; i
< thresholds
->primary
->size
; i
++) {
4271 if (thresholds
->primary
->entries
[i
].eventfd
== eventfd
)
4274 new->entries
[j
] = thresholds
->primary
->entries
[i
];
4275 if (new->entries
[j
].threshold
<= usage
) {
4277 * new->current_threshold will not be used
4278 * until rcu_assign_pointer(), so it's safe to increment
4281 ++new->current_threshold
;
4287 /* Swap primary and spare array */
4288 thresholds
->spare
= thresholds
->primary
;
4290 rcu_assign_pointer(thresholds
->primary
, new);
4292 /* To be sure that nobody uses thresholds */
4295 /* If all events are unregistered, free the spare array */
4297 kfree(thresholds
->spare
);
4298 thresholds
->spare
= NULL
;
4301 mutex_unlock(&memcg
->thresholds_lock
);
4304 static void mem_cgroup_usage_unregister_event(struct mem_cgroup
*memcg
,
4305 struct eventfd_ctx
*eventfd
)
4307 return __mem_cgroup_usage_unregister_event(memcg
, eventfd
, _MEM
);
4310 static void memsw_cgroup_usage_unregister_event(struct mem_cgroup
*memcg
,
4311 struct eventfd_ctx
*eventfd
)
4313 return __mem_cgroup_usage_unregister_event(memcg
, eventfd
, _MEMSWAP
);
4316 static int mem_cgroup_oom_register_event(struct mem_cgroup
*memcg
,
4317 struct eventfd_ctx
*eventfd
, const char *args
)
4319 struct mem_cgroup_eventfd_list
*event
;
4321 event
= kmalloc(sizeof(*event
), GFP_KERNEL
);
4325 spin_lock(&memcg_oom_lock
);
4327 event
->eventfd
= eventfd
;
4328 list_add(&event
->list
, &memcg
->oom_notify
);
4330 /* already in OOM ? */
4331 if (memcg
->under_oom
)
4332 eventfd_signal(eventfd
, 1);
4333 spin_unlock(&memcg_oom_lock
);
4338 static void mem_cgroup_oom_unregister_event(struct mem_cgroup
*memcg
,
4339 struct eventfd_ctx
*eventfd
)
4341 struct mem_cgroup_eventfd_list
*ev
, *tmp
;
4343 spin_lock(&memcg_oom_lock
);
4345 list_for_each_entry_safe(ev
, tmp
, &memcg
->oom_notify
, list
) {
4346 if (ev
->eventfd
== eventfd
) {
4347 list_del(&ev
->list
);
4352 spin_unlock(&memcg_oom_lock
);
4355 static int mem_cgroup_oom_control_read(struct seq_file
*sf
, void *v
)
4357 struct mem_cgroup
*memcg
= mem_cgroup_from_seq(sf
);
4359 seq_printf(sf
, "oom_kill_disable %d\n", memcg
->oom_kill_disable
);
4360 seq_printf(sf
, "under_oom %d\n", (bool)memcg
->under_oom
);
4361 seq_printf(sf
, "oom_kill %lu\n",
4362 atomic_long_read(&memcg
->memory_events
[MEMCG_OOM_KILL
]));
4366 static int mem_cgroup_oom_control_write(struct cgroup_subsys_state
*css
,
4367 struct cftype
*cft
, u64 val
)
4369 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
4371 /* cannot set to root cgroup and only 0 and 1 are allowed */
4372 if (!css
->parent
|| !((val
== 0) || (val
== 1)))
4375 memcg
->oom_kill_disable
= val
;
4377 memcg_oom_recover(memcg
);
4382 #ifdef CONFIG_CGROUP_WRITEBACK
4384 #include <trace/events/writeback.h>
4386 static int memcg_wb_domain_init(struct mem_cgroup
*memcg
, gfp_t gfp
)
4388 return wb_domain_init(&memcg
->cgwb_domain
, gfp
);
4391 static void memcg_wb_domain_exit(struct mem_cgroup
*memcg
)
4393 wb_domain_exit(&memcg
->cgwb_domain
);
4396 static void memcg_wb_domain_size_changed(struct mem_cgroup
*memcg
)
4398 wb_domain_size_changed(&memcg
->cgwb_domain
);
4401 struct wb_domain
*mem_cgroup_wb_domain(struct bdi_writeback
*wb
)
4403 struct mem_cgroup
*memcg
= mem_cgroup_from_css(wb
->memcg_css
);
4405 if (!memcg
->css
.parent
)
4408 return &memcg
->cgwb_domain
;
4412 * idx can be of type enum memcg_stat_item or node_stat_item.
4413 * Keep in sync with memcg_exact_page().
4415 static unsigned long memcg_exact_page_state(struct mem_cgroup
*memcg
, int idx
)
4417 long x
= atomic_long_read(&memcg
->vmstats
[idx
]);
4420 for_each_online_cpu(cpu
)
4421 x
+= per_cpu_ptr(memcg
->vmstats_percpu
, cpu
)->stat
[idx
];
4428 * mem_cgroup_wb_stats - retrieve writeback related stats from its memcg
4429 * @wb: bdi_writeback in question
4430 * @pfilepages: out parameter for number of file pages
4431 * @pheadroom: out parameter for number of allocatable pages according to memcg
4432 * @pdirty: out parameter for number of dirty pages
4433 * @pwriteback: out parameter for number of pages under writeback
4435 * Determine the numbers of file, headroom, dirty, and writeback pages in
4436 * @wb's memcg. File, dirty and writeback are self-explanatory. Headroom
4437 * is a bit more involved.
4439 * A memcg's headroom is "min(max, high) - used". In the hierarchy, the
4440 * headroom is calculated as the lowest headroom of itself and the
4441 * ancestors. Note that this doesn't consider the actual amount of
4442 * available memory in the system. The caller should further cap
4443 * *@pheadroom accordingly.
4445 void mem_cgroup_wb_stats(struct bdi_writeback
*wb
, unsigned long *pfilepages
,
4446 unsigned long *pheadroom
, unsigned long *pdirty
,
4447 unsigned long *pwriteback
)
4449 struct mem_cgroup
*memcg
= mem_cgroup_from_css(wb
->memcg_css
);
4450 struct mem_cgroup
*parent
;
4452 *pdirty
= memcg_exact_page_state(memcg
, NR_FILE_DIRTY
);
4454 /* this should eventually include NR_UNSTABLE_NFS */
4455 *pwriteback
= memcg_exact_page_state(memcg
, NR_WRITEBACK
);
4456 *pfilepages
= memcg_exact_page_state(memcg
, NR_INACTIVE_FILE
) +
4457 memcg_exact_page_state(memcg
, NR_ACTIVE_FILE
);
4458 *pheadroom
= PAGE_COUNTER_MAX
;
4460 while ((parent
= parent_mem_cgroup(memcg
))) {
4461 unsigned long ceiling
= min(memcg
->memory
.max
, memcg
->high
);
4462 unsigned long used
= page_counter_read(&memcg
->memory
);
4464 *pheadroom
= min(*pheadroom
, ceiling
- min(ceiling
, used
));
4470 * Foreign dirty flushing
4472 * There's an inherent mismatch between memcg and writeback. The former
4473 * trackes ownership per-page while the latter per-inode. This was a
4474 * deliberate design decision because honoring per-page ownership in the
4475 * writeback path is complicated, may lead to higher CPU and IO overheads
4476 * and deemed unnecessary given that write-sharing an inode across
4477 * different cgroups isn't a common use-case.
4479 * Combined with inode majority-writer ownership switching, this works well
4480 * enough in most cases but there are some pathological cases. For
4481 * example, let's say there are two cgroups A and B which keep writing to
4482 * different but confined parts of the same inode. B owns the inode and
4483 * A's memory is limited far below B's. A's dirty ratio can rise enough to
4484 * trigger balance_dirty_pages() sleeps but B's can be low enough to avoid
4485 * triggering background writeback. A will be slowed down without a way to
4486 * make writeback of the dirty pages happen.
4488 * Conditions like the above can lead to a cgroup getting repatedly and
4489 * severely throttled after making some progress after each
4490 * dirty_expire_interval while the underyling IO device is almost
4493 * Solving this problem completely requires matching the ownership tracking
4494 * granularities between memcg and writeback in either direction. However,
4495 * the more egregious behaviors can be avoided by simply remembering the
4496 * most recent foreign dirtying events and initiating remote flushes on
4497 * them when local writeback isn't enough to keep the memory clean enough.
4499 * The following two functions implement such mechanism. When a foreign
4500 * page - a page whose memcg and writeback ownerships don't match - is
4501 * dirtied, mem_cgroup_track_foreign_dirty() records the inode owning
4502 * bdi_writeback on the page owning memcg. When balance_dirty_pages()
4503 * decides that the memcg needs to sleep due to high dirty ratio, it calls
4504 * mem_cgroup_flush_foreign() which queues writeback on the recorded
4505 * foreign bdi_writebacks which haven't expired. Both the numbers of
4506 * recorded bdi_writebacks and concurrent in-flight foreign writebacks are
4507 * limited to MEMCG_CGWB_FRN_CNT.
4509 * The mechanism only remembers IDs and doesn't hold any object references.
4510 * As being wrong occasionally doesn't matter, updates and accesses to the
4511 * records are lockless and racy.
4513 void mem_cgroup_track_foreign_dirty_slowpath(struct page
*page
,
4514 struct bdi_writeback
*wb
)
4516 struct mem_cgroup
*memcg
= page
->mem_cgroup
;
4517 struct memcg_cgwb_frn
*frn
;
4518 u64 now
= get_jiffies_64();
4519 u64 oldest_at
= now
;
4523 trace_track_foreign_dirty(page
, wb
);
4526 * Pick the slot to use. If there is already a slot for @wb, keep
4527 * using it. If not replace the oldest one which isn't being
4530 for (i
= 0; i
< MEMCG_CGWB_FRN_CNT
; i
++) {
4531 frn
= &memcg
->cgwb_frn
[i
];
4532 if (frn
->bdi_id
== wb
->bdi
->id
&&
4533 frn
->memcg_id
== wb
->memcg_css
->id
)
4535 if (time_before64(frn
->at
, oldest_at
) &&
4536 atomic_read(&frn
->done
.cnt
) == 1) {
4538 oldest_at
= frn
->at
;
4542 if (i
< MEMCG_CGWB_FRN_CNT
) {
4544 * Re-using an existing one. Update timestamp lazily to
4545 * avoid making the cacheline hot. We want them to be
4546 * reasonably up-to-date and significantly shorter than
4547 * dirty_expire_interval as that's what expires the record.
4548 * Use the shorter of 1s and dirty_expire_interval / 8.
4550 unsigned long update_intv
=
4551 min_t(unsigned long, HZ
,
4552 msecs_to_jiffies(dirty_expire_interval
* 10) / 8);
4554 if (time_before64(frn
->at
, now
- update_intv
))
4556 } else if (oldest
>= 0) {
4557 /* replace the oldest free one */
4558 frn
= &memcg
->cgwb_frn
[oldest
];
4559 frn
->bdi_id
= wb
->bdi
->id
;
4560 frn
->memcg_id
= wb
->memcg_css
->id
;
4565 /* issue foreign writeback flushes for recorded foreign dirtying events */
4566 void mem_cgroup_flush_foreign(struct bdi_writeback
*wb
)
4568 struct mem_cgroup
*memcg
= mem_cgroup_from_css(wb
->memcg_css
);
4569 unsigned long intv
= msecs_to_jiffies(dirty_expire_interval
* 10);
4570 u64 now
= jiffies_64
;
4573 for (i
= 0; i
< MEMCG_CGWB_FRN_CNT
; i
++) {
4574 struct memcg_cgwb_frn
*frn
= &memcg
->cgwb_frn
[i
];
4577 * If the record is older than dirty_expire_interval,
4578 * writeback on it has already started. No need to kick it
4579 * off again. Also, don't start a new one if there's
4580 * already one in flight.
4582 if (time_after64(frn
->at
, now
- intv
) &&
4583 atomic_read(&frn
->done
.cnt
) == 1) {
4585 trace_flush_foreign(wb
, frn
->bdi_id
, frn
->memcg_id
);
4586 cgroup_writeback_by_id(frn
->bdi_id
, frn
->memcg_id
, 0,
4587 WB_REASON_FOREIGN_FLUSH
,
4593 #else /* CONFIG_CGROUP_WRITEBACK */
4595 static int memcg_wb_domain_init(struct mem_cgroup
*memcg
, gfp_t gfp
)
4600 static void memcg_wb_domain_exit(struct mem_cgroup
*memcg
)
4604 static void memcg_wb_domain_size_changed(struct mem_cgroup
*memcg
)
4608 #endif /* CONFIG_CGROUP_WRITEBACK */
4611 * DO NOT USE IN NEW FILES.
4613 * "cgroup.event_control" implementation.
4615 * This is way over-engineered. It tries to support fully configurable
4616 * events for each user. Such level of flexibility is completely
4617 * unnecessary especially in the light of the planned unified hierarchy.
4619 * Please deprecate this and replace with something simpler if at all
4624 * Unregister event and free resources.
4626 * Gets called from workqueue.
4628 static void memcg_event_remove(struct work_struct
*work
)
4630 struct mem_cgroup_event
*event
=
4631 container_of(work
, struct mem_cgroup_event
, remove
);
4632 struct mem_cgroup
*memcg
= event
->memcg
;
4634 remove_wait_queue(event
->wqh
, &event
->wait
);
4636 event
->unregister_event(memcg
, event
->eventfd
);
4638 /* Notify userspace the event is going away. */
4639 eventfd_signal(event
->eventfd
, 1);
4641 eventfd_ctx_put(event
->eventfd
);
4643 css_put(&memcg
->css
);
4647 * Gets called on EPOLLHUP on eventfd when user closes it.
4649 * Called with wqh->lock held and interrupts disabled.
4651 static int memcg_event_wake(wait_queue_entry_t
*wait
, unsigned mode
,
4652 int sync
, void *key
)
4654 struct mem_cgroup_event
*event
=
4655 container_of(wait
, struct mem_cgroup_event
, wait
);
4656 struct mem_cgroup
*memcg
= event
->memcg
;
4657 __poll_t flags
= key_to_poll(key
);
4659 if (flags
& EPOLLHUP
) {
4661 * If the event has been detached at cgroup removal, we
4662 * can simply return knowing the other side will cleanup
4665 * We can't race against event freeing since the other
4666 * side will require wqh->lock via remove_wait_queue(),
4669 spin_lock(&memcg
->event_list_lock
);
4670 if (!list_empty(&event
->list
)) {
4671 list_del_init(&event
->list
);
4673 * We are in atomic context, but cgroup_event_remove()
4674 * may sleep, so we have to call it in workqueue.
4676 schedule_work(&event
->remove
);
4678 spin_unlock(&memcg
->event_list_lock
);
4684 static void memcg_event_ptable_queue_proc(struct file
*file
,
4685 wait_queue_head_t
*wqh
, poll_table
*pt
)
4687 struct mem_cgroup_event
*event
=
4688 container_of(pt
, struct mem_cgroup_event
, pt
);
4691 add_wait_queue(wqh
, &event
->wait
);
4695 * DO NOT USE IN NEW FILES.
4697 * Parse input and register new cgroup event handler.
4699 * Input must be in format '<event_fd> <control_fd> <args>'.
4700 * Interpretation of args is defined by control file implementation.
4702 static ssize_t
memcg_write_event_control(struct kernfs_open_file
*of
,
4703 char *buf
, size_t nbytes
, loff_t off
)
4705 struct cgroup_subsys_state
*css
= of_css(of
);
4706 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
4707 struct mem_cgroup_event
*event
;
4708 struct cgroup_subsys_state
*cfile_css
;
4709 unsigned int efd
, cfd
;
4716 buf
= strstrip(buf
);
4718 efd
= simple_strtoul(buf
, &endp
, 10);
4723 cfd
= simple_strtoul(buf
, &endp
, 10);
4724 if ((*endp
!= ' ') && (*endp
!= '\0'))
4728 event
= kzalloc(sizeof(*event
), GFP_KERNEL
);
4732 event
->memcg
= memcg
;
4733 INIT_LIST_HEAD(&event
->list
);
4734 init_poll_funcptr(&event
->pt
, memcg_event_ptable_queue_proc
);
4735 init_waitqueue_func_entry(&event
->wait
, memcg_event_wake
);
4736 INIT_WORK(&event
->remove
, memcg_event_remove
);
4744 event
->eventfd
= eventfd_ctx_fileget(efile
.file
);
4745 if (IS_ERR(event
->eventfd
)) {
4746 ret
= PTR_ERR(event
->eventfd
);
4753 goto out_put_eventfd
;
4756 /* the process need read permission on control file */
4757 /* AV: shouldn't we check that it's been opened for read instead? */
4758 ret
= inode_permission(file_inode(cfile
.file
), MAY_READ
);
4763 * Determine the event callbacks and set them in @event. This used
4764 * to be done via struct cftype but cgroup core no longer knows
4765 * about these events. The following is crude but the whole thing
4766 * is for compatibility anyway.
4768 * DO NOT ADD NEW FILES.
4770 name
= cfile
.file
->f_path
.dentry
->d_name
.name
;
4772 if (!strcmp(name
, "memory.usage_in_bytes")) {
4773 event
->register_event
= mem_cgroup_usage_register_event
;
4774 event
->unregister_event
= mem_cgroup_usage_unregister_event
;
4775 } else if (!strcmp(name
, "memory.oom_control")) {
4776 event
->register_event
= mem_cgroup_oom_register_event
;
4777 event
->unregister_event
= mem_cgroup_oom_unregister_event
;
4778 } else if (!strcmp(name
, "memory.pressure_level")) {
4779 event
->register_event
= vmpressure_register_event
;
4780 event
->unregister_event
= vmpressure_unregister_event
;
4781 } else if (!strcmp(name
, "memory.memsw.usage_in_bytes")) {
4782 event
->register_event
= memsw_cgroup_usage_register_event
;
4783 event
->unregister_event
= memsw_cgroup_usage_unregister_event
;
4790 * Verify @cfile should belong to @css. Also, remaining events are
4791 * automatically removed on cgroup destruction but the removal is
4792 * asynchronous, so take an extra ref on @css.
4794 cfile_css
= css_tryget_online_from_dir(cfile
.file
->f_path
.dentry
->d_parent
,
4795 &memory_cgrp_subsys
);
4797 if (IS_ERR(cfile_css
))
4799 if (cfile_css
!= css
) {
4804 ret
= event
->register_event(memcg
, event
->eventfd
, buf
);
4808 vfs_poll(efile
.file
, &event
->pt
);
4810 spin_lock(&memcg
->event_list_lock
);
4811 list_add(&event
->list
, &memcg
->event_list
);
4812 spin_unlock(&memcg
->event_list_lock
);
4824 eventfd_ctx_put(event
->eventfd
);
4833 static struct cftype mem_cgroup_legacy_files
[] = {
4835 .name
= "usage_in_bytes",
4836 .private = MEMFILE_PRIVATE(_MEM
, RES_USAGE
),
4837 .read_u64
= mem_cgroup_read_u64
,
4840 .name
= "max_usage_in_bytes",
4841 .private = MEMFILE_PRIVATE(_MEM
, RES_MAX_USAGE
),
4842 .write
= mem_cgroup_reset
,
4843 .read_u64
= mem_cgroup_read_u64
,
4846 .name
= "limit_in_bytes",
4847 .private = MEMFILE_PRIVATE(_MEM
, RES_LIMIT
),
4848 .write
= mem_cgroup_write
,
4849 .read_u64
= mem_cgroup_read_u64
,
4852 .name
= "soft_limit_in_bytes",
4853 .private = MEMFILE_PRIVATE(_MEM
, RES_SOFT_LIMIT
),
4854 .write
= mem_cgroup_write
,
4855 .read_u64
= mem_cgroup_read_u64
,
4859 .private = MEMFILE_PRIVATE(_MEM
, RES_FAILCNT
),
4860 .write
= mem_cgroup_reset
,
4861 .read_u64
= mem_cgroup_read_u64
,
4865 .seq_show
= memcg_stat_show
,
4868 .name
= "force_empty",
4869 .write
= mem_cgroup_force_empty_write
,
4872 .name
= "use_hierarchy",
4873 .write_u64
= mem_cgroup_hierarchy_write
,
4874 .read_u64
= mem_cgroup_hierarchy_read
,
4877 .name
= "cgroup.event_control", /* XXX: for compat */
4878 .write
= memcg_write_event_control
,
4879 .flags
= CFTYPE_NO_PREFIX
| CFTYPE_WORLD_WRITABLE
,
4882 .name
= "swappiness",
4883 .read_u64
= mem_cgroup_swappiness_read
,
4884 .write_u64
= mem_cgroup_swappiness_write
,
4887 .name
= "move_charge_at_immigrate",
4888 .read_u64
= mem_cgroup_move_charge_read
,
4889 .write_u64
= mem_cgroup_move_charge_write
,
4892 .name
= "oom_control",
4893 .seq_show
= mem_cgroup_oom_control_read
,
4894 .write_u64
= mem_cgroup_oom_control_write
,
4895 .private = MEMFILE_PRIVATE(_OOM_TYPE
, OOM_CONTROL
),
4898 .name
= "pressure_level",
4902 .name
= "numa_stat",
4903 .seq_show
= memcg_numa_stat_show
,
4907 .name
= "kmem.limit_in_bytes",
4908 .private = MEMFILE_PRIVATE(_KMEM
, RES_LIMIT
),
4909 .write
= mem_cgroup_write
,
4910 .read_u64
= mem_cgroup_read_u64
,
4913 .name
= "kmem.usage_in_bytes",
4914 .private = MEMFILE_PRIVATE(_KMEM
, RES_USAGE
),
4915 .read_u64
= mem_cgroup_read_u64
,
4918 .name
= "kmem.failcnt",
4919 .private = MEMFILE_PRIVATE(_KMEM
, RES_FAILCNT
),
4920 .write
= mem_cgroup_reset
,
4921 .read_u64
= mem_cgroup_read_u64
,
4924 .name
= "kmem.max_usage_in_bytes",
4925 .private = MEMFILE_PRIVATE(_KMEM
, RES_MAX_USAGE
),
4926 .write
= mem_cgroup_reset
,
4927 .read_u64
= mem_cgroup_read_u64
,
4929 #if defined(CONFIG_SLAB) || defined(CONFIG_SLUB_DEBUG)
4931 .name
= "kmem.slabinfo",
4932 .seq_start
= memcg_slab_start
,
4933 .seq_next
= memcg_slab_next
,
4934 .seq_stop
= memcg_slab_stop
,
4935 .seq_show
= memcg_slab_show
,
4939 .name
= "kmem.tcp.limit_in_bytes",
4940 .private = MEMFILE_PRIVATE(_TCP
, RES_LIMIT
),
4941 .write
= mem_cgroup_write
,
4942 .read_u64
= mem_cgroup_read_u64
,
4945 .name
= "kmem.tcp.usage_in_bytes",
4946 .private = MEMFILE_PRIVATE(_TCP
, RES_USAGE
),
4947 .read_u64
= mem_cgroup_read_u64
,
4950 .name
= "kmem.tcp.failcnt",
4951 .private = MEMFILE_PRIVATE(_TCP
, RES_FAILCNT
),
4952 .write
= mem_cgroup_reset
,
4953 .read_u64
= mem_cgroup_read_u64
,
4956 .name
= "kmem.tcp.max_usage_in_bytes",
4957 .private = MEMFILE_PRIVATE(_TCP
, RES_MAX_USAGE
),
4958 .write
= mem_cgroup_reset
,
4959 .read_u64
= mem_cgroup_read_u64
,
4961 { }, /* terminate */
4965 * Private memory cgroup IDR
4967 * Swap-out records and page cache shadow entries need to store memcg
4968 * references in constrained space, so we maintain an ID space that is
4969 * limited to 16 bit (MEM_CGROUP_ID_MAX), limiting the total number of
4970 * memory-controlled cgroups to 64k.
4972 * However, there usually are many references to the oflline CSS after
4973 * the cgroup has been destroyed, such as page cache or reclaimable
4974 * slab objects, that don't need to hang on to the ID. We want to keep
4975 * those dead CSS from occupying IDs, or we might quickly exhaust the
4976 * relatively small ID space and prevent the creation of new cgroups
4977 * even when there are much fewer than 64k cgroups - possibly none.
4979 * Maintain a private 16-bit ID space for memcg, and allow the ID to
4980 * be freed and recycled when it's no longer needed, which is usually
4981 * when the CSS is offlined.
4983 * The only exception to that are records of swapped out tmpfs/shmem
4984 * pages that need to be attributed to live ancestors on swapin. But
4985 * those references are manageable from userspace.
4988 static DEFINE_IDR(mem_cgroup_idr
);
4990 static void mem_cgroup_id_remove(struct mem_cgroup
*memcg
)
4992 if (memcg
->id
.id
> 0) {
4993 idr_remove(&mem_cgroup_idr
, memcg
->id
.id
);
4998 static void mem_cgroup_id_get_many(struct mem_cgroup
*memcg
, unsigned int n
)
5000 refcount_add(n
, &memcg
->id
.ref
);
5003 static void mem_cgroup_id_put_many(struct mem_cgroup
*memcg
, unsigned int n
)
5005 if (refcount_sub_and_test(n
, &memcg
->id
.ref
)) {
5006 mem_cgroup_id_remove(memcg
);
5008 /* Memcg ID pins CSS */
5009 css_put(&memcg
->css
);
5013 static inline void mem_cgroup_id_put(struct mem_cgroup
*memcg
)
5015 mem_cgroup_id_put_many(memcg
, 1);
5019 * mem_cgroup_from_id - look up a memcg from a memcg id
5020 * @id: the memcg id to look up
5022 * Caller must hold rcu_read_lock().
5024 struct mem_cgroup
*mem_cgroup_from_id(unsigned short id
)
5026 WARN_ON_ONCE(!rcu_read_lock_held());
5027 return idr_find(&mem_cgroup_idr
, id
);
5030 static int alloc_mem_cgroup_per_node_info(struct mem_cgroup
*memcg
, int node
)
5032 struct mem_cgroup_per_node
*pn
;
5035 * This routine is called against possible nodes.
5036 * But it's BUG to call kmalloc() against offline node.
5038 * TODO: this routine can waste much memory for nodes which will
5039 * never be onlined. It's better to use memory hotplug callback
5042 if (!node_state(node
, N_NORMAL_MEMORY
))
5044 pn
= kzalloc_node(sizeof(*pn
), GFP_KERNEL
, tmp
);
5048 pn
->lruvec_stat_local
= alloc_percpu(struct lruvec_stat
);
5049 if (!pn
->lruvec_stat_local
) {
5054 pn
->lruvec_stat_cpu
= alloc_percpu(struct lruvec_stat
);
5055 if (!pn
->lruvec_stat_cpu
) {
5056 free_percpu(pn
->lruvec_stat_local
);
5061 lruvec_init(&pn
->lruvec
);
5062 pn
->usage_in_excess
= 0;
5063 pn
->on_tree
= false;
5066 memcg
->nodeinfo
[node
] = pn
;
5070 static void free_mem_cgroup_per_node_info(struct mem_cgroup
*memcg
, int node
)
5072 struct mem_cgroup_per_node
*pn
= memcg
->nodeinfo
[node
];
5077 free_percpu(pn
->lruvec_stat_cpu
);
5078 free_percpu(pn
->lruvec_stat_local
);
5082 static void __mem_cgroup_free(struct mem_cgroup
*memcg
)
5087 free_mem_cgroup_per_node_info(memcg
, node
);
5088 free_percpu(memcg
->vmstats_percpu
);
5089 free_percpu(memcg
->vmstats_local
);
5093 static void mem_cgroup_free(struct mem_cgroup
*memcg
)
5095 memcg_wb_domain_exit(memcg
);
5097 * Flush percpu vmstats and vmevents to guarantee the value correctness
5098 * on parent's and all ancestor levels.
5100 memcg_flush_percpu_vmstats(memcg
);
5101 memcg_flush_percpu_vmevents(memcg
);
5102 __mem_cgroup_free(memcg
);
5105 static struct mem_cgroup
*mem_cgroup_alloc(void)
5107 struct mem_cgroup
*memcg
;
5110 int __maybe_unused i
;
5111 long error
= -ENOMEM
;
5113 size
= sizeof(struct mem_cgroup
);
5114 size
+= nr_node_ids
* sizeof(struct mem_cgroup_per_node
*);
5116 memcg
= kzalloc(size
, GFP_KERNEL
);
5118 return ERR_PTR(error
);
5120 memcg
->id
.id
= idr_alloc(&mem_cgroup_idr
, NULL
,
5121 1, MEM_CGROUP_ID_MAX
,
5123 if (memcg
->id
.id
< 0) {
5124 error
= memcg
->id
.id
;
5128 memcg
->vmstats_local
= alloc_percpu(struct memcg_vmstats_percpu
);
5129 if (!memcg
->vmstats_local
)
5132 memcg
->vmstats_percpu
= alloc_percpu(struct memcg_vmstats_percpu
);
5133 if (!memcg
->vmstats_percpu
)
5137 if (alloc_mem_cgroup_per_node_info(memcg
, node
))
5140 if (memcg_wb_domain_init(memcg
, GFP_KERNEL
))
5143 INIT_WORK(&memcg
->high_work
, high_work_func
);
5144 memcg
->last_scanned_node
= MAX_NUMNODES
;
5145 INIT_LIST_HEAD(&memcg
->oom_notify
);
5146 mutex_init(&memcg
->thresholds_lock
);
5147 spin_lock_init(&memcg
->move_lock
);
5148 vmpressure_init(&memcg
->vmpressure
);
5149 INIT_LIST_HEAD(&memcg
->event_list
);
5150 spin_lock_init(&memcg
->event_list_lock
);
5151 memcg
->socket_pressure
= jiffies
;
5152 #ifdef CONFIG_MEMCG_KMEM
5153 memcg
->kmemcg_id
= -1;
5155 #ifdef CONFIG_CGROUP_WRITEBACK
5156 INIT_LIST_HEAD(&memcg
->cgwb_list
);
5157 for (i
= 0; i
< MEMCG_CGWB_FRN_CNT
; i
++)
5158 memcg
->cgwb_frn
[i
].done
=
5159 __WB_COMPLETION_INIT(&memcg_cgwb_frn_waitq
);
5161 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
5162 spin_lock_init(&memcg
->deferred_split_queue
.split_queue_lock
);
5163 INIT_LIST_HEAD(&memcg
->deferred_split_queue
.split_queue
);
5164 memcg
->deferred_split_queue
.split_queue_len
= 0;
5166 idr_replace(&mem_cgroup_idr
, memcg
, memcg
->id
.id
);
5169 mem_cgroup_id_remove(memcg
);
5170 __mem_cgroup_free(memcg
);
5171 return ERR_PTR(error
);
5174 static struct cgroup_subsys_state
* __ref
5175 mem_cgroup_css_alloc(struct cgroup_subsys_state
*parent_css
)
5177 struct mem_cgroup
*parent
= mem_cgroup_from_css(parent_css
);
5178 struct mem_cgroup
*memcg
;
5179 long error
= -ENOMEM
;
5181 memcg
= mem_cgroup_alloc();
5183 return ERR_CAST(memcg
);
5185 memcg
->high
= PAGE_COUNTER_MAX
;
5186 memcg
->soft_limit
= PAGE_COUNTER_MAX
;
5188 memcg
->swappiness
= mem_cgroup_swappiness(parent
);
5189 memcg
->oom_kill_disable
= parent
->oom_kill_disable
;
5191 if (parent
&& parent
->use_hierarchy
) {
5192 memcg
->use_hierarchy
= true;
5193 page_counter_init(&memcg
->memory
, &parent
->memory
);
5194 page_counter_init(&memcg
->swap
, &parent
->swap
);
5195 page_counter_init(&memcg
->memsw
, &parent
->memsw
);
5196 page_counter_init(&memcg
->kmem
, &parent
->kmem
);
5197 page_counter_init(&memcg
->tcpmem
, &parent
->tcpmem
);
5199 page_counter_init(&memcg
->memory
, NULL
);
5200 page_counter_init(&memcg
->swap
, NULL
);
5201 page_counter_init(&memcg
->memsw
, NULL
);
5202 page_counter_init(&memcg
->kmem
, NULL
);
5203 page_counter_init(&memcg
->tcpmem
, NULL
);
5205 * Deeper hierachy with use_hierarchy == false doesn't make
5206 * much sense so let cgroup subsystem know about this
5207 * unfortunate state in our controller.
5209 if (parent
!= root_mem_cgroup
)
5210 memory_cgrp_subsys
.broken_hierarchy
= true;
5213 /* The following stuff does not apply to the root */
5215 #ifdef CONFIG_MEMCG_KMEM
5216 INIT_LIST_HEAD(&memcg
->kmem_caches
);
5218 root_mem_cgroup
= memcg
;
5222 error
= memcg_online_kmem(memcg
);
5226 if (cgroup_subsys_on_dfl(memory_cgrp_subsys
) && !cgroup_memory_nosocket
)
5227 static_branch_inc(&memcg_sockets_enabled_key
);
5231 mem_cgroup_id_remove(memcg
);
5232 mem_cgroup_free(memcg
);
5233 return ERR_PTR(error
);
5236 static int mem_cgroup_css_online(struct cgroup_subsys_state
*css
)
5238 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
5241 * A memcg must be visible for memcg_expand_shrinker_maps()
5242 * by the time the maps are allocated. So, we allocate maps
5243 * here, when for_each_mem_cgroup() can't skip it.
5245 if (memcg_alloc_shrinker_maps(memcg
)) {
5246 mem_cgroup_id_remove(memcg
);
5250 /* Online state pins memcg ID, memcg ID pins CSS */
5251 refcount_set(&memcg
->id
.ref
, 1);
5256 static void mem_cgroup_css_offline(struct cgroup_subsys_state
*css
)
5258 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
5259 struct mem_cgroup_event
*event
, *tmp
;
5262 * Unregister events and notify userspace.
5263 * Notify userspace about cgroup removing only after rmdir of cgroup
5264 * directory to avoid race between userspace and kernelspace.
5266 spin_lock(&memcg
->event_list_lock
);
5267 list_for_each_entry_safe(event
, tmp
, &memcg
->event_list
, list
) {
5268 list_del_init(&event
->list
);
5269 schedule_work(&event
->remove
);
5271 spin_unlock(&memcg
->event_list_lock
);
5273 page_counter_set_min(&memcg
->memory
, 0);
5274 page_counter_set_low(&memcg
->memory
, 0);
5276 memcg_offline_kmem(memcg
);
5277 wb_memcg_offline(memcg
);
5279 drain_all_stock(memcg
);
5281 mem_cgroup_id_put(memcg
);
5284 static void mem_cgroup_css_released(struct cgroup_subsys_state
*css
)
5286 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
5288 invalidate_reclaim_iterators(memcg
);
5291 static void mem_cgroup_css_free(struct cgroup_subsys_state
*css
)
5293 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
5294 int __maybe_unused i
;
5296 #ifdef CONFIG_CGROUP_WRITEBACK
5297 for (i
= 0; i
< MEMCG_CGWB_FRN_CNT
; i
++)
5298 wb_wait_for_completion(&memcg
->cgwb_frn
[i
].done
);
5300 if (cgroup_subsys_on_dfl(memory_cgrp_subsys
) && !cgroup_memory_nosocket
)
5301 static_branch_dec(&memcg_sockets_enabled_key
);
5303 if (!cgroup_subsys_on_dfl(memory_cgrp_subsys
) && memcg
->tcpmem_active
)
5304 static_branch_dec(&memcg_sockets_enabled_key
);
5306 vmpressure_cleanup(&memcg
->vmpressure
);
5307 cancel_work_sync(&memcg
->high_work
);
5308 mem_cgroup_remove_from_trees(memcg
);
5309 memcg_free_shrinker_maps(memcg
);
5310 memcg_free_kmem(memcg
);
5311 mem_cgroup_free(memcg
);
5315 * mem_cgroup_css_reset - reset the states of a mem_cgroup
5316 * @css: the target css
5318 * Reset the states of the mem_cgroup associated with @css. This is
5319 * invoked when the userland requests disabling on the default hierarchy
5320 * but the memcg is pinned through dependency. The memcg should stop
5321 * applying policies and should revert to the vanilla state as it may be
5322 * made visible again.
5324 * The current implementation only resets the essential configurations.
5325 * This needs to be expanded to cover all the visible parts.
5327 static void mem_cgroup_css_reset(struct cgroup_subsys_state
*css
)
5329 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
5331 page_counter_set_max(&memcg
->memory
, PAGE_COUNTER_MAX
);
5332 page_counter_set_max(&memcg
->swap
, PAGE_COUNTER_MAX
);
5333 page_counter_set_max(&memcg
->memsw
, PAGE_COUNTER_MAX
);
5334 page_counter_set_max(&memcg
->kmem
, PAGE_COUNTER_MAX
);
5335 page_counter_set_max(&memcg
->tcpmem
, PAGE_COUNTER_MAX
);
5336 page_counter_set_min(&memcg
->memory
, 0);
5337 page_counter_set_low(&memcg
->memory
, 0);
5338 memcg
->high
= PAGE_COUNTER_MAX
;
5339 memcg
->soft_limit
= PAGE_COUNTER_MAX
;
5340 memcg_wb_domain_size_changed(memcg
);
5344 /* Handlers for move charge at task migration. */
5345 static int mem_cgroup_do_precharge(unsigned long count
)
5349 /* Try a single bulk charge without reclaim first, kswapd may wake */
5350 ret
= try_charge(mc
.to
, GFP_KERNEL
& ~__GFP_DIRECT_RECLAIM
, count
);
5352 mc
.precharge
+= count
;
5356 /* Try charges one by one with reclaim, but do not retry */
5358 ret
= try_charge(mc
.to
, GFP_KERNEL
| __GFP_NORETRY
, 1);
5372 enum mc_target_type
{
5379 static struct page
*mc_handle_present_pte(struct vm_area_struct
*vma
,
5380 unsigned long addr
, pte_t ptent
)
5382 struct page
*page
= vm_normal_page(vma
, addr
, ptent
);
5384 if (!page
|| !page_mapped(page
))
5386 if (PageAnon(page
)) {
5387 if (!(mc
.flags
& MOVE_ANON
))
5390 if (!(mc
.flags
& MOVE_FILE
))
5393 if (!get_page_unless_zero(page
))
5399 #if defined(CONFIG_SWAP) || defined(CONFIG_DEVICE_PRIVATE)
5400 static struct page
*mc_handle_swap_pte(struct vm_area_struct
*vma
,
5401 pte_t ptent
, swp_entry_t
*entry
)
5403 struct page
*page
= NULL
;
5404 swp_entry_t ent
= pte_to_swp_entry(ptent
);
5406 if (!(mc
.flags
& MOVE_ANON
))
5410 * Handle MEMORY_DEVICE_PRIVATE which are ZONE_DEVICE page belonging to
5411 * a device and because they are not accessible by CPU they are store
5412 * as special swap entry in the CPU page table.
5414 if (is_device_private_entry(ent
)) {
5415 page
= device_private_entry_to_page(ent
);
5417 * MEMORY_DEVICE_PRIVATE means ZONE_DEVICE page and which have
5418 * a refcount of 1 when free (unlike normal page)
5420 if (!page_ref_add_unless(page
, 1, 1))
5425 if (non_swap_entry(ent
))
5429 * Because lookup_swap_cache() updates some statistics counter,
5430 * we call find_get_page() with swapper_space directly.
5432 page
= find_get_page(swap_address_space(ent
), swp_offset(ent
));
5433 if (do_memsw_account())
5434 entry
->val
= ent
.val
;
5439 static struct page
*mc_handle_swap_pte(struct vm_area_struct
*vma
,
5440 pte_t ptent
, swp_entry_t
*entry
)
5446 static struct page
*mc_handle_file_pte(struct vm_area_struct
*vma
,
5447 unsigned long addr
, pte_t ptent
, swp_entry_t
*entry
)
5449 struct page
*page
= NULL
;
5450 struct address_space
*mapping
;
5453 if (!vma
->vm_file
) /* anonymous vma */
5455 if (!(mc
.flags
& MOVE_FILE
))
5458 mapping
= vma
->vm_file
->f_mapping
;
5459 pgoff
= linear_page_index(vma
, addr
);
5461 /* page is moved even if it's not RSS of this task(page-faulted). */
5463 /* shmem/tmpfs may report page out on swap: account for that too. */
5464 if (shmem_mapping(mapping
)) {
5465 page
= find_get_entry(mapping
, pgoff
);
5466 if (xa_is_value(page
)) {
5467 swp_entry_t swp
= radix_to_swp_entry(page
);
5468 if (do_memsw_account())
5470 page
= find_get_page(swap_address_space(swp
),
5474 page
= find_get_page(mapping
, pgoff
);
5476 page
= find_get_page(mapping
, pgoff
);
5482 * mem_cgroup_move_account - move account of the page
5484 * @compound: charge the page as compound or small page
5485 * @from: mem_cgroup which the page is moved from.
5486 * @to: mem_cgroup which the page is moved to. @from != @to.
5488 * The caller must make sure the page is not on LRU (isolate_page() is useful.)
5490 * This function doesn't do "charge" to new cgroup and doesn't do "uncharge"
5493 static int mem_cgroup_move_account(struct page
*page
,
5495 struct mem_cgroup
*from
,
5496 struct mem_cgroup
*to
)
5498 struct lruvec
*from_vec
, *to_vec
;
5499 struct pglist_data
*pgdat
;
5500 unsigned int nr_pages
= compound
? hpage_nr_pages(page
) : 1;
5504 VM_BUG_ON(from
== to
);
5505 VM_BUG_ON_PAGE(PageLRU(page
), page
);
5506 VM_BUG_ON(compound
&& !PageTransHuge(page
));
5509 * Prevent mem_cgroup_migrate() from looking at
5510 * page->mem_cgroup of its source page while we change it.
5513 if (!trylock_page(page
))
5517 if (page
->mem_cgroup
!= from
)
5520 anon
= PageAnon(page
);
5522 pgdat
= page_pgdat(page
);
5523 from_vec
= mem_cgroup_lruvec(pgdat
, from
);
5524 to_vec
= mem_cgroup_lruvec(pgdat
, to
);
5526 lock_page_memcg(page
);
5528 if (!anon
&& page_mapped(page
)) {
5529 __mod_lruvec_state(from_vec
, NR_FILE_MAPPED
, -nr_pages
);
5530 __mod_lruvec_state(to_vec
, NR_FILE_MAPPED
, nr_pages
);
5533 if (!anon
&& PageDirty(page
)) {
5534 struct address_space
*mapping
= page_mapping(page
);
5536 if (mapping_cap_account_dirty(mapping
)) {
5537 __mod_lruvec_state(from_vec
, NR_FILE_DIRTY
, -nr_pages
);
5538 __mod_lruvec_state(to_vec
, NR_FILE_DIRTY
, nr_pages
);
5542 if (PageWriteback(page
)) {
5543 __mod_lruvec_state(from_vec
, NR_WRITEBACK
, -nr_pages
);
5544 __mod_lruvec_state(to_vec
, NR_WRITEBACK
, nr_pages
);
5548 * All state has been migrated, let's switch to the new memcg.
5550 * It is safe to change page->mem_cgroup here because the page
5551 * is referenced, charged, isolated, and locked: we can't race
5552 * with (un)charging, migration, LRU putback, or anything else
5553 * that would rely on a stable page->mem_cgroup.
5555 * Note that lock_page_memcg is a memcg lock, not a page lock,
5556 * to save space. As soon as we switch page->mem_cgroup to a
5557 * new memcg that isn't locked, the above state can change
5558 * concurrently again. Make sure we're truly done with it.
5562 page
->mem_cgroup
= to
; /* caller should have done css_get */
5564 __unlock_page_memcg(from
);
5568 local_irq_disable();
5569 mem_cgroup_charge_statistics(to
, page
, compound
, nr_pages
);
5570 memcg_check_events(to
, page
);
5571 mem_cgroup_charge_statistics(from
, page
, compound
, -nr_pages
);
5572 memcg_check_events(from
, page
);
5581 * get_mctgt_type - get target type of moving charge
5582 * @vma: the vma the pte to be checked belongs
5583 * @addr: the address corresponding to the pte to be checked
5584 * @ptent: the pte to be checked
5585 * @target: the pointer the target page or swap ent will be stored(can be NULL)
5588 * 0(MC_TARGET_NONE): if the pte is not a target for move charge.
5589 * 1(MC_TARGET_PAGE): if the page corresponding to this pte is a target for
5590 * move charge. if @target is not NULL, the page is stored in target->page
5591 * with extra refcnt got(Callers should handle it).
5592 * 2(MC_TARGET_SWAP): if the swap entry corresponding to this pte is a
5593 * target for charge migration. if @target is not NULL, the entry is stored
5595 * 3(MC_TARGET_DEVICE): like MC_TARGET_PAGE but page is MEMORY_DEVICE_PRIVATE
5596 * (so ZONE_DEVICE page and thus not on the lru).
5597 * For now we such page is charge like a regular page would be as for all
5598 * intent and purposes it is just special memory taking the place of a
5601 * See Documentations/vm/hmm.txt and include/linux/hmm.h
5603 * Called with pte lock held.
5606 static enum mc_target_type
get_mctgt_type(struct vm_area_struct
*vma
,
5607 unsigned long addr
, pte_t ptent
, union mc_target
*target
)
5609 struct page
*page
= NULL
;
5610 enum mc_target_type ret
= MC_TARGET_NONE
;
5611 swp_entry_t ent
= { .val
= 0 };
5613 if (pte_present(ptent
))
5614 page
= mc_handle_present_pte(vma
, addr
, ptent
);
5615 else if (is_swap_pte(ptent
))
5616 page
= mc_handle_swap_pte(vma
, ptent
, &ent
);
5617 else if (pte_none(ptent
))
5618 page
= mc_handle_file_pte(vma
, addr
, ptent
, &ent
);
5620 if (!page
&& !ent
.val
)
5624 * Do only loose check w/o serialization.
5625 * mem_cgroup_move_account() checks the page is valid or
5626 * not under LRU exclusion.
5628 if (page
->mem_cgroup
== mc
.from
) {
5629 ret
= MC_TARGET_PAGE
;
5630 if (is_device_private_page(page
))
5631 ret
= MC_TARGET_DEVICE
;
5633 target
->page
= page
;
5635 if (!ret
|| !target
)
5639 * There is a swap entry and a page doesn't exist or isn't charged.
5640 * But we cannot move a tail-page in a THP.
5642 if (ent
.val
&& !ret
&& (!page
|| !PageTransCompound(page
)) &&
5643 mem_cgroup_id(mc
.from
) == lookup_swap_cgroup_id(ent
)) {
5644 ret
= MC_TARGET_SWAP
;
5651 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
5653 * We don't consider PMD mapped swapping or file mapped pages because THP does
5654 * not support them for now.
5655 * Caller should make sure that pmd_trans_huge(pmd) is true.
5657 static enum mc_target_type
get_mctgt_type_thp(struct vm_area_struct
*vma
,
5658 unsigned long addr
, pmd_t pmd
, union mc_target
*target
)
5660 struct page
*page
= NULL
;
5661 enum mc_target_type ret
= MC_TARGET_NONE
;
5663 if (unlikely(is_swap_pmd(pmd
))) {
5664 VM_BUG_ON(thp_migration_supported() &&
5665 !is_pmd_migration_entry(pmd
));
5668 page
= pmd_page(pmd
);
5669 VM_BUG_ON_PAGE(!page
|| !PageHead(page
), page
);
5670 if (!(mc
.flags
& MOVE_ANON
))
5672 if (page
->mem_cgroup
== mc
.from
) {
5673 ret
= MC_TARGET_PAGE
;
5676 target
->page
= page
;
5682 static inline enum mc_target_type
get_mctgt_type_thp(struct vm_area_struct
*vma
,
5683 unsigned long addr
, pmd_t pmd
, union mc_target
*target
)
5685 return MC_TARGET_NONE
;
5689 static int mem_cgroup_count_precharge_pte_range(pmd_t
*pmd
,
5690 unsigned long addr
, unsigned long end
,
5691 struct mm_walk
*walk
)
5693 struct vm_area_struct
*vma
= walk
->vma
;
5697 ptl
= pmd_trans_huge_lock(pmd
, vma
);
5700 * Note their can not be MC_TARGET_DEVICE for now as we do not
5701 * support transparent huge page with MEMORY_DEVICE_PRIVATE but
5702 * this might change.
5704 if (get_mctgt_type_thp(vma
, addr
, *pmd
, NULL
) == MC_TARGET_PAGE
)
5705 mc
.precharge
+= HPAGE_PMD_NR
;
5710 if (pmd_trans_unstable(pmd
))
5712 pte
= pte_offset_map_lock(vma
->vm_mm
, pmd
, addr
, &ptl
);
5713 for (; addr
!= end
; pte
++, addr
+= PAGE_SIZE
)
5714 if (get_mctgt_type(vma
, addr
, *pte
, NULL
))
5715 mc
.precharge
++; /* increment precharge temporarily */
5716 pte_unmap_unlock(pte
- 1, ptl
);
5722 static const struct mm_walk_ops precharge_walk_ops
= {
5723 .pmd_entry
= mem_cgroup_count_precharge_pte_range
,
5726 static unsigned long mem_cgroup_count_precharge(struct mm_struct
*mm
)
5728 unsigned long precharge
;
5730 down_read(&mm
->mmap_sem
);
5731 walk_page_range(mm
, 0, mm
->highest_vm_end
, &precharge_walk_ops
, NULL
);
5732 up_read(&mm
->mmap_sem
);
5734 precharge
= mc
.precharge
;
5740 static int mem_cgroup_precharge_mc(struct mm_struct
*mm
)
5742 unsigned long precharge
= mem_cgroup_count_precharge(mm
);
5744 VM_BUG_ON(mc
.moving_task
);
5745 mc
.moving_task
= current
;
5746 return mem_cgroup_do_precharge(precharge
);
5749 /* cancels all extra charges on mc.from and mc.to, and wakes up all waiters. */
5750 static void __mem_cgroup_clear_mc(void)
5752 struct mem_cgroup
*from
= mc
.from
;
5753 struct mem_cgroup
*to
= mc
.to
;
5755 /* we must uncharge all the leftover precharges from mc.to */
5757 cancel_charge(mc
.to
, mc
.precharge
);
5761 * we didn't uncharge from mc.from at mem_cgroup_move_account(), so
5762 * we must uncharge here.
5764 if (mc
.moved_charge
) {
5765 cancel_charge(mc
.from
, mc
.moved_charge
);
5766 mc
.moved_charge
= 0;
5768 /* we must fixup refcnts and charges */
5769 if (mc
.moved_swap
) {
5770 /* uncharge swap account from the old cgroup */
5771 if (!mem_cgroup_is_root(mc
.from
))
5772 page_counter_uncharge(&mc
.from
->memsw
, mc
.moved_swap
);
5774 mem_cgroup_id_put_many(mc
.from
, mc
.moved_swap
);
5777 * we charged both to->memory and to->memsw, so we
5778 * should uncharge to->memory.
5780 if (!mem_cgroup_is_root(mc
.to
))
5781 page_counter_uncharge(&mc
.to
->memory
, mc
.moved_swap
);
5783 css_put_many(&mc
.to
->css
, mc
.moved_swap
);
5787 memcg_oom_recover(from
);
5788 memcg_oom_recover(to
);
5789 wake_up_all(&mc
.waitq
);
5792 static void mem_cgroup_clear_mc(void)
5794 struct mm_struct
*mm
= mc
.mm
;
5797 * we must clear moving_task before waking up waiters at the end of
5800 mc
.moving_task
= NULL
;
5801 __mem_cgroup_clear_mc();
5802 spin_lock(&mc
.lock
);
5806 spin_unlock(&mc
.lock
);
5811 static int mem_cgroup_can_attach(struct cgroup_taskset
*tset
)
5813 struct cgroup_subsys_state
*css
;
5814 struct mem_cgroup
*memcg
= NULL
; /* unneeded init to make gcc happy */
5815 struct mem_cgroup
*from
;
5816 struct task_struct
*leader
, *p
;
5817 struct mm_struct
*mm
;
5818 unsigned long move_flags
;
5821 /* charge immigration isn't supported on the default hierarchy */
5822 if (cgroup_subsys_on_dfl(memory_cgrp_subsys
))
5826 * Multi-process migrations only happen on the default hierarchy
5827 * where charge immigration is not used. Perform charge
5828 * immigration if @tset contains a leader and whine if there are
5832 cgroup_taskset_for_each_leader(leader
, css
, tset
) {
5835 memcg
= mem_cgroup_from_css(css
);
5841 * We are now commited to this value whatever it is. Changes in this
5842 * tunable will only affect upcoming migrations, not the current one.
5843 * So we need to save it, and keep it going.
5845 move_flags
= READ_ONCE(memcg
->move_charge_at_immigrate
);
5849 from
= mem_cgroup_from_task(p
);
5851 VM_BUG_ON(from
== memcg
);
5853 mm
= get_task_mm(p
);
5856 /* We move charges only when we move a owner of the mm */
5857 if (mm
->owner
== p
) {
5860 VM_BUG_ON(mc
.precharge
);
5861 VM_BUG_ON(mc
.moved_charge
);
5862 VM_BUG_ON(mc
.moved_swap
);
5864 spin_lock(&mc
.lock
);
5868 mc
.flags
= move_flags
;
5869 spin_unlock(&mc
.lock
);
5870 /* We set mc.moving_task later */
5872 ret
= mem_cgroup_precharge_mc(mm
);
5874 mem_cgroup_clear_mc();
5881 static void mem_cgroup_cancel_attach(struct cgroup_taskset
*tset
)
5884 mem_cgroup_clear_mc();
5887 static int mem_cgroup_move_charge_pte_range(pmd_t
*pmd
,
5888 unsigned long addr
, unsigned long end
,
5889 struct mm_walk
*walk
)
5892 struct vm_area_struct
*vma
= walk
->vma
;
5895 enum mc_target_type target_type
;
5896 union mc_target target
;
5899 ptl
= pmd_trans_huge_lock(pmd
, vma
);
5901 if (mc
.precharge
< HPAGE_PMD_NR
) {
5905 target_type
= get_mctgt_type_thp(vma
, addr
, *pmd
, &target
);
5906 if (target_type
== MC_TARGET_PAGE
) {
5908 if (!isolate_lru_page(page
)) {
5909 if (!mem_cgroup_move_account(page
, true,
5911 mc
.precharge
-= HPAGE_PMD_NR
;
5912 mc
.moved_charge
+= HPAGE_PMD_NR
;
5914 putback_lru_page(page
);
5917 } else if (target_type
== MC_TARGET_DEVICE
) {
5919 if (!mem_cgroup_move_account(page
, true,
5921 mc
.precharge
-= HPAGE_PMD_NR
;
5922 mc
.moved_charge
+= HPAGE_PMD_NR
;
5930 if (pmd_trans_unstable(pmd
))
5933 pte
= pte_offset_map_lock(vma
->vm_mm
, pmd
, addr
, &ptl
);
5934 for (; addr
!= end
; addr
+= PAGE_SIZE
) {
5935 pte_t ptent
= *(pte
++);
5936 bool device
= false;
5942 switch (get_mctgt_type(vma
, addr
, ptent
, &target
)) {
5943 case MC_TARGET_DEVICE
:
5946 case MC_TARGET_PAGE
:
5949 * We can have a part of the split pmd here. Moving it
5950 * can be done but it would be too convoluted so simply
5951 * ignore such a partial THP and keep it in original
5952 * memcg. There should be somebody mapping the head.
5954 if (PageTransCompound(page
))
5956 if (!device
&& isolate_lru_page(page
))
5958 if (!mem_cgroup_move_account(page
, false,
5961 /* we uncharge from mc.from later. */
5965 putback_lru_page(page
);
5966 put
: /* get_mctgt_type() gets the page */
5969 case MC_TARGET_SWAP
:
5971 if (!mem_cgroup_move_swap_account(ent
, mc
.from
, mc
.to
)) {
5973 mem_cgroup_id_get_many(mc
.to
, 1);
5974 /* we fixup other refcnts and charges later. */
5982 pte_unmap_unlock(pte
- 1, ptl
);
5987 * We have consumed all precharges we got in can_attach().
5988 * We try charge one by one, but don't do any additional
5989 * charges to mc.to if we have failed in charge once in attach()
5992 ret
= mem_cgroup_do_precharge(1);
6000 static const struct mm_walk_ops charge_walk_ops
= {
6001 .pmd_entry
= mem_cgroup_move_charge_pte_range
,
6004 static void mem_cgroup_move_charge(void)
6006 lru_add_drain_all();
6008 * Signal lock_page_memcg() to take the memcg's move_lock
6009 * while we're moving its pages to another memcg. Then wait
6010 * for already started RCU-only updates to finish.
6012 atomic_inc(&mc
.from
->moving_account
);
6015 if (unlikely(!down_read_trylock(&mc
.mm
->mmap_sem
))) {
6017 * Someone who are holding the mmap_sem might be waiting in
6018 * waitq. So we cancel all extra charges, wake up all waiters,
6019 * and retry. Because we cancel precharges, we might not be able
6020 * to move enough charges, but moving charge is a best-effort
6021 * feature anyway, so it wouldn't be a big problem.
6023 __mem_cgroup_clear_mc();
6028 * When we have consumed all precharges and failed in doing
6029 * additional charge, the page walk just aborts.
6031 walk_page_range(mc
.mm
, 0, mc
.mm
->highest_vm_end
, &charge_walk_ops
,
6034 up_read(&mc
.mm
->mmap_sem
);
6035 atomic_dec(&mc
.from
->moving_account
);
6038 static void mem_cgroup_move_task(void)
6041 mem_cgroup_move_charge();
6042 mem_cgroup_clear_mc();
6045 #else /* !CONFIG_MMU */
6046 static int mem_cgroup_can_attach(struct cgroup_taskset
*tset
)
6050 static void mem_cgroup_cancel_attach(struct cgroup_taskset
*tset
)
6053 static void mem_cgroup_move_task(void)
6059 * Cgroup retains root cgroups across [un]mount cycles making it necessary
6060 * to verify whether we're attached to the default hierarchy on each mount
6063 static void mem_cgroup_bind(struct cgroup_subsys_state
*root_css
)
6066 * use_hierarchy is forced on the default hierarchy. cgroup core
6067 * guarantees that @root doesn't have any children, so turning it
6068 * on for the root memcg is enough.
6070 if (cgroup_subsys_on_dfl(memory_cgrp_subsys
))
6071 root_mem_cgroup
->use_hierarchy
= true;
6073 root_mem_cgroup
->use_hierarchy
= false;
6076 static int seq_puts_memcg_tunable(struct seq_file
*m
, unsigned long value
)
6078 if (value
== PAGE_COUNTER_MAX
)
6079 seq_puts(m
, "max\n");
6081 seq_printf(m
, "%llu\n", (u64
)value
* PAGE_SIZE
);
6086 static u64
memory_current_read(struct cgroup_subsys_state
*css
,
6089 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
6091 return (u64
)page_counter_read(&memcg
->memory
) * PAGE_SIZE
;
6094 static int memory_min_show(struct seq_file
*m
, void *v
)
6096 return seq_puts_memcg_tunable(m
,
6097 READ_ONCE(mem_cgroup_from_seq(m
)->memory
.min
));
6100 static ssize_t
memory_min_write(struct kernfs_open_file
*of
,
6101 char *buf
, size_t nbytes
, loff_t off
)
6103 struct mem_cgroup
*memcg
= mem_cgroup_from_css(of_css(of
));
6107 buf
= strstrip(buf
);
6108 err
= page_counter_memparse(buf
, "max", &min
);
6112 page_counter_set_min(&memcg
->memory
, min
);
6117 static int memory_low_show(struct seq_file
*m
, void *v
)
6119 return seq_puts_memcg_tunable(m
,
6120 READ_ONCE(mem_cgroup_from_seq(m
)->memory
.low
));
6123 static ssize_t
memory_low_write(struct kernfs_open_file
*of
,
6124 char *buf
, size_t nbytes
, loff_t off
)
6126 struct mem_cgroup
*memcg
= mem_cgroup_from_css(of_css(of
));
6130 buf
= strstrip(buf
);
6131 err
= page_counter_memparse(buf
, "max", &low
);
6135 page_counter_set_low(&memcg
->memory
, low
);
6140 static int memory_high_show(struct seq_file
*m
, void *v
)
6142 return seq_puts_memcg_tunable(m
, READ_ONCE(mem_cgroup_from_seq(m
)->high
));
6145 static ssize_t
memory_high_write(struct kernfs_open_file
*of
,
6146 char *buf
, size_t nbytes
, loff_t off
)
6148 struct mem_cgroup
*memcg
= mem_cgroup_from_css(of_css(of
));
6149 unsigned long nr_pages
;
6153 buf
= strstrip(buf
);
6154 err
= page_counter_memparse(buf
, "max", &high
);
6160 nr_pages
= page_counter_read(&memcg
->memory
);
6161 if (nr_pages
> high
)
6162 try_to_free_mem_cgroup_pages(memcg
, nr_pages
- high
,
6165 memcg_wb_domain_size_changed(memcg
);
6169 static int memory_max_show(struct seq_file
*m
, void *v
)
6171 return seq_puts_memcg_tunable(m
,
6172 READ_ONCE(mem_cgroup_from_seq(m
)->memory
.max
));
6175 static ssize_t
memory_max_write(struct kernfs_open_file
*of
,
6176 char *buf
, size_t nbytes
, loff_t off
)
6178 struct mem_cgroup
*memcg
= mem_cgroup_from_css(of_css(of
));
6179 unsigned int nr_reclaims
= MEM_CGROUP_RECLAIM_RETRIES
;
6180 bool drained
= false;
6184 buf
= strstrip(buf
);
6185 err
= page_counter_memparse(buf
, "max", &max
);
6189 xchg(&memcg
->memory
.max
, max
);
6192 unsigned long nr_pages
= page_counter_read(&memcg
->memory
);
6194 if (nr_pages
<= max
)
6197 if (signal_pending(current
)) {
6203 drain_all_stock(memcg
);
6209 if (!try_to_free_mem_cgroup_pages(memcg
, nr_pages
- max
,
6215 memcg_memory_event(memcg
, MEMCG_OOM
);
6216 if (!mem_cgroup_out_of_memory(memcg
, GFP_KERNEL
, 0))
6220 memcg_wb_domain_size_changed(memcg
);
6224 static void __memory_events_show(struct seq_file
*m
, atomic_long_t
*events
)
6226 seq_printf(m
, "low %lu\n", atomic_long_read(&events
[MEMCG_LOW
]));
6227 seq_printf(m
, "high %lu\n", atomic_long_read(&events
[MEMCG_HIGH
]));
6228 seq_printf(m
, "max %lu\n", atomic_long_read(&events
[MEMCG_MAX
]));
6229 seq_printf(m
, "oom %lu\n", atomic_long_read(&events
[MEMCG_OOM
]));
6230 seq_printf(m
, "oom_kill %lu\n",
6231 atomic_long_read(&events
[MEMCG_OOM_KILL
]));
6234 static int memory_events_show(struct seq_file
*m
, void *v
)
6236 struct mem_cgroup
*memcg
= mem_cgroup_from_seq(m
);
6238 __memory_events_show(m
, memcg
->memory_events
);
6242 static int memory_events_local_show(struct seq_file
*m
, void *v
)
6244 struct mem_cgroup
*memcg
= mem_cgroup_from_seq(m
);
6246 __memory_events_show(m
, memcg
->memory_events_local
);
6250 static int memory_stat_show(struct seq_file
*m
, void *v
)
6252 struct mem_cgroup
*memcg
= mem_cgroup_from_seq(m
);
6255 buf
= memory_stat_format(memcg
);
6263 static int memory_oom_group_show(struct seq_file
*m
, void *v
)
6265 struct mem_cgroup
*memcg
= mem_cgroup_from_seq(m
);
6267 seq_printf(m
, "%d\n", memcg
->oom_group
);
6272 static ssize_t
memory_oom_group_write(struct kernfs_open_file
*of
,
6273 char *buf
, size_t nbytes
, loff_t off
)
6275 struct mem_cgroup
*memcg
= mem_cgroup_from_css(of_css(of
));
6278 buf
= strstrip(buf
);
6282 ret
= kstrtoint(buf
, 0, &oom_group
);
6286 if (oom_group
!= 0 && oom_group
!= 1)
6289 memcg
->oom_group
= oom_group
;
6294 static struct cftype memory_files
[] = {
6297 .flags
= CFTYPE_NOT_ON_ROOT
,
6298 .read_u64
= memory_current_read
,
6302 .flags
= CFTYPE_NOT_ON_ROOT
,
6303 .seq_show
= memory_min_show
,
6304 .write
= memory_min_write
,
6308 .flags
= CFTYPE_NOT_ON_ROOT
,
6309 .seq_show
= memory_low_show
,
6310 .write
= memory_low_write
,
6314 .flags
= CFTYPE_NOT_ON_ROOT
,
6315 .seq_show
= memory_high_show
,
6316 .write
= memory_high_write
,
6320 .flags
= CFTYPE_NOT_ON_ROOT
,
6321 .seq_show
= memory_max_show
,
6322 .write
= memory_max_write
,
6326 .flags
= CFTYPE_NOT_ON_ROOT
,
6327 .file_offset
= offsetof(struct mem_cgroup
, events_file
),
6328 .seq_show
= memory_events_show
,
6331 .name
= "events.local",
6332 .flags
= CFTYPE_NOT_ON_ROOT
,
6333 .file_offset
= offsetof(struct mem_cgroup
, events_local_file
),
6334 .seq_show
= memory_events_local_show
,
6338 .flags
= CFTYPE_NOT_ON_ROOT
,
6339 .seq_show
= memory_stat_show
,
6342 .name
= "oom.group",
6343 .flags
= CFTYPE_NOT_ON_ROOT
| CFTYPE_NS_DELEGATABLE
,
6344 .seq_show
= memory_oom_group_show
,
6345 .write
= memory_oom_group_write
,
6350 struct cgroup_subsys memory_cgrp_subsys
= {
6351 .css_alloc
= mem_cgroup_css_alloc
,
6352 .css_online
= mem_cgroup_css_online
,
6353 .css_offline
= mem_cgroup_css_offline
,
6354 .css_released
= mem_cgroup_css_released
,
6355 .css_free
= mem_cgroup_css_free
,
6356 .css_reset
= mem_cgroup_css_reset
,
6357 .can_attach
= mem_cgroup_can_attach
,
6358 .cancel_attach
= mem_cgroup_cancel_attach
,
6359 .post_attach
= mem_cgroup_move_task
,
6360 .bind
= mem_cgroup_bind
,
6361 .dfl_cftypes
= memory_files
,
6362 .legacy_cftypes
= mem_cgroup_legacy_files
,
6367 * mem_cgroup_protected - check if memory consumption is in the normal range
6368 * @root: the top ancestor of the sub-tree being checked
6369 * @memcg: the memory cgroup to check
6371 * WARNING: This function is not stateless! It can only be used as part
6372 * of a top-down tree iteration, not for isolated queries.
6374 * Returns one of the following:
6375 * MEMCG_PROT_NONE: cgroup memory is not protected
6376 * MEMCG_PROT_LOW: cgroup memory is protected as long there is
6377 * an unprotected supply of reclaimable memory from other cgroups.
6378 * MEMCG_PROT_MIN: cgroup memory is protected
6380 * @root is exclusive; it is never protected when looked at directly
6382 * To provide a proper hierarchical behavior, effective memory.min/low values
6383 * are used. Below is the description of how effective memory.low is calculated.
6384 * Effective memory.min values is calculated in the same way.
6386 * Effective memory.low is always equal or less than the original memory.low.
6387 * If there is no memory.low overcommittment (which is always true for
6388 * top-level memory cgroups), these two values are equal.
6389 * Otherwise, it's a part of parent's effective memory.low,
6390 * calculated as a cgroup's memory.low usage divided by sum of sibling's
6391 * memory.low usages, where memory.low usage is the size of actually
6395 * elow = min( memory.low, parent->elow * ------------------ ),
6396 * siblings_low_usage
6398 * | memory.current, if memory.current < memory.low
6403 * Such definition of the effective memory.low provides the expected
6404 * hierarchical behavior: parent's memory.low value is limiting
6405 * children, unprotected memory is reclaimed first and cgroups,
6406 * which are not using their guarantee do not affect actual memory
6409 * For example, if there are memcgs A, A/B, A/C, A/D and A/E:
6411 * A A/memory.low = 2G, A/memory.current = 6G
6413 * BC DE B/memory.low = 3G B/memory.current = 2G
6414 * C/memory.low = 1G C/memory.current = 2G
6415 * D/memory.low = 0 D/memory.current = 2G
6416 * E/memory.low = 10G E/memory.current = 0
6418 * and the memory pressure is applied, the following memory distribution
6419 * is expected (approximately):
6421 * A/memory.current = 2G
6423 * B/memory.current = 1.3G
6424 * C/memory.current = 0.6G
6425 * D/memory.current = 0
6426 * E/memory.current = 0
6428 * These calculations require constant tracking of the actual low usages
6429 * (see propagate_protected_usage()), as well as recursive calculation of
6430 * effective memory.low values. But as we do call mem_cgroup_protected()
6431 * path for each memory cgroup top-down from the reclaim,
6432 * it's possible to optimize this part, and save calculated elow
6433 * for next usage. This part is intentionally racy, but it's ok,
6434 * as memory.low is a best-effort mechanism.
6436 enum mem_cgroup_protection
mem_cgroup_protected(struct mem_cgroup
*root
,
6437 struct mem_cgroup
*memcg
)
6439 struct mem_cgroup
*parent
;
6440 unsigned long emin
, parent_emin
;
6441 unsigned long elow
, parent_elow
;
6442 unsigned long usage
;
6444 if (mem_cgroup_disabled())
6445 return MEMCG_PROT_NONE
;
6448 root
= root_mem_cgroup
;
6451 * Effective values of the reclaim targets are ignored so they
6452 * can be stale. Have a look at mem_cgroup_protection for more
6454 * TODO: calculation should be more robust so that we do not need
6455 * that special casing.
6458 return MEMCG_PROT_NONE
;
6460 usage
= page_counter_read(&memcg
->memory
);
6462 return MEMCG_PROT_NONE
;
6464 emin
= memcg
->memory
.min
;
6465 elow
= memcg
->memory
.low
;
6467 parent
= parent_mem_cgroup(memcg
);
6468 /* No parent means a non-hierarchical mode on v1 memcg */
6470 return MEMCG_PROT_NONE
;
6475 parent_emin
= READ_ONCE(parent
->memory
.emin
);
6476 emin
= min(emin
, parent_emin
);
6477 if (emin
&& parent_emin
) {
6478 unsigned long min_usage
, siblings_min_usage
;
6480 min_usage
= min(usage
, memcg
->memory
.min
);
6481 siblings_min_usage
= atomic_long_read(
6482 &parent
->memory
.children_min_usage
);
6484 if (min_usage
&& siblings_min_usage
)
6485 emin
= min(emin
, parent_emin
* min_usage
/
6486 siblings_min_usage
);
6489 parent_elow
= READ_ONCE(parent
->memory
.elow
);
6490 elow
= min(elow
, parent_elow
);
6491 if (elow
&& parent_elow
) {
6492 unsigned long low_usage
, siblings_low_usage
;
6494 low_usage
= min(usage
, memcg
->memory
.low
);
6495 siblings_low_usage
= atomic_long_read(
6496 &parent
->memory
.children_low_usage
);
6498 if (low_usage
&& siblings_low_usage
)
6499 elow
= min(elow
, parent_elow
* low_usage
/
6500 siblings_low_usage
);
6504 memcg
->memory
.emin
= emin
;
6505 memcg
->memory
.elow
= elow
;
6508 return MEMCG_PROT_MIN
;
6509 else if (usage
<= elow
)
6510 return MEMCG_PROT_LOW
;
6512 return MEMCG_PROT_NONE
;
6516 * mem_cgroup_try_charge - try charging a page
6517 * @page: page to charge
6518 * @mm: mm context of the victim
6519 * @gfp_mask: reclaim mode
6520 * @memcgp: charged memcg return
6521 * @compound: charge the page as compound or small page
6523 * Try to charge @page to the memcg that @mm belongs to, reclaiming
6524 * pages according to @gfp_mask if necessary.
6526 * Returns 0 on success, with *@memcgp pointing to the charged memcg.
6527 * Otherwise, an error code is returned.
6529 * After page->mapping has been set up, the caller must finalize the
6530 * charge with mem_cgroup_commit_charge(). Or abort the transaction
6531 * with mem_cgroup_cancel_charge() in case page instantiation fails.
6533 int mem_cgroup_try_charge(struct page
*page
, struct mm_struct
*mm
,
6534 gfp_t gfp_mask
, struct mem_cgroup
**memcgp
,
6537 struct mem_cgroup
*memcg
= NULL
;
6538 unsigned int nr_pages
= compound
? hpage_nr_pages(page
) : 1;
6541 if (mem_cgroup_disabled())
6544 if (PageSwapCache(page
)) {
6546 * Every swap fault against a single page tries to charge the
6547 * page, bail as early as possible. shmem_unuse() encounters
6548 * already charged pages, too. The USED bit is protected by
6549 * the page lock, which serializes swap cache removal, which
6550 * in turn serializes uncharging.
6552 VM_BUG_ON_PAGE(!PageLocked(page
), page
);
6553 if (compound_head(page
)->mem_cgroup
)
6556 if (do_swap_account
) {
6557 swp_entry_t ent
= { .val
= page_private(page
), };
6558 unsigned short id
= lookup_swap_cgroup_id(ent
);
6561 memcg
= mem_cgroup_from_id(id
);
6562 if (memcg
&& !css_tryget_online(&memcg
->css
))
6569 memcg
= get_mem_cgroup_from_mm(mm
);
6571 ret
= try_charge(memcg
, gfp_mask
, nr_pages
);
6573 css_put(&memcg
->css
);
6579 int mem_cgroup_try_charge_delay(struct page
*page
, struct mm_struct
*mm
,
6580 gfp_t gfp_mask
, struct mem_cgroup
**memcgp
,
6583 struct mem_cgroup
*memcg
;
6586 ret
= mem_cgroup_try_charge(page
, mm
, gfp_mask
, memcgp
, compound
);
6588 mem_cgroup_throttle_swaprate(memcg
, page_to_nid(page
), gfp_mask
);
6593 * mem_cgroup_commit_charge - commit a page charge
6594 * @page: page to charge
6595 * @memcg: memcg to charge the page to
6596 * @lrucare: page might be on LRU already
6597 * @compound: charge the page as compound or small page
6599 * Finalize a charge transaction started by mem_cgroup_try_charge(),
6600 * after page->mapping has been set up. This must happen atomically
6601 * as part of the page instantiation, i.e. under the page table lock
6602 * for anonymous pages, under the page lock for page and swap cache.
6604 * In addition, the page must not be on the LRU during the commit, to
6605 * prevent racing with task migration. If it might be, use @lrucare.
6607 * Use mem_cgroup_cancel_charge() to cancel the transaction instead.
6609 void mem_cgroup_commit_charge(struct page
*page
, struct mem_cgroup
*memcg
,
6610 bool lrucare
, bool compound
)
6612 unsigned int nr_pages
= compound
? hpage_nr_pages(page
) : 1;
6614 VM_BUG_ON_PAGE(!page
->mapping
, page
);
6615 VM_BUG_ON_PAGE(PageLRU(page
) && !lrucare
, page
);
6617 if (mem_cgroup_disabled())
6620 * Swap faults will attempt to charge the same page multiple
6621 * times. But reuse_swap_page() might have removed the page
6622 * from swapcache already, so we can't check PageSwapCache().
6627 commit_charge(page
, memcg
, lrucare
);
6629 local_irq_disable();
6630 mem_cgroup_charge_statistics(memcg
, page
, compound
, nr_pages
);
6631 memcg_check_events(memcg
, page
);
6634 if (do_memsw_account() && PageSwapCache(page
)) {
6635 swp_entry_t entry
= { .val
= page_private(page
) };
6637 * The swap entry might not get freed for a long time,
6638 * let's not wait for it. The page already received a
6639 * memory+swap charge, drop the swap entry duplicate.
6641 mem_cgroup_uncharge_swap(entry
, nr_pages
);
6646 * mem_cgroup_cancel_charge - cancel a page charge
6647 * @page: page to charge
6648 * @memcg: memcg to charge the page to
6649 * @compound: charge the page as compound or small page
6651 * Cancel a charge transaction started by mem_cgroup_try_charge().
6653 void mem_cgroup_cancel_charge(struct page
*page
, struct mem_cgroup
*memcg
,
6656 unsigned int nr_pages
= compound
? hpage_nr_pages(page
) : 1;
6658 if (mem_cgroup_disabled())
6661 * Swap faults will attempt to charge the same page multiple
6662 * times. But reuse_swap_page() might have removed the page
6663 * from swapcache already, so we can't check PageSwapCache().
6668 cancel_charge(memcg
, nr_pages
);
6671 struct uncharge_gather
{
6672 struct mem_cgroup
*memcg
;
6673 unsigned long pgpgout
;
6674 unsigned long nr_anon
;
6675 unsigned long nr_file
;
6676 unsigned long nr_kmem
;
6677 unsigned long nr_huge
;
6678 unsigned long nr_shmem
;
6679 struct page
*dummy_page
;
6682 static inline void uncharge_gather_clear(struct uncharge_gather
*ug
)
6684 memset(ug
, 0, sizeof(*ug
));
6687 static void uncharge_batch(const struct uncharge_gather
*ug
)
6689 unsigned long nr_pages
= ug
->nr_anon
+ ug
->nr_file
+ ug
->nr_kmem
;
6690 unsigned long flags
;
6692 if (!mem_cgroup_is_root(ug
->memcg
)) {
6693 page_counter_uncharge(&ug
->memcg
->memory
, nr_pages
);
6694 if (do_memsw_account())
6695 page_counter_uncharge(&ug
->memcg
->memsw
, nr_pages
);
6696 if (!cgroup_subsys_on_dfl(memory_cgrp_subsys
) && ug
->nr_kmem
)
6697 page_counter_uncharge(&ug
->memcg
->kmem
, ug
->nr_kmem
);
6698 memcg_oom_recover(ug
->memcg
);
6701 local_irq_save(flags
);
6702 __mod_memcg_state(ug
->memcg
, MEMCG_RSS
, -ug
->nr_anon
);
6703 __mod_memcg_state(ug
->memcg
, MEMCG_CACHE
, -ug
->nr_file
);
6704 __mod_memcg_state(ug
->memcg
, MEMCG_RSS_HUGE
, -ug
->nr_huge
);
6705 __mod_memcg_state(ug
->memcg
, NR_SHMEM
, -ug
->nr_shmem
);
6706 __count_memcg_events(ug
->memcg
, PGPGOUT
, ug
->pgpgout
);
6707 __this_cpu_add(ug
->memcg
->vmstats_percpu
->nr_page_events
, nr_pages
);
6708 memcg_check_events(ug
->memcg
, ug
->dummy_page
);
6709 local_irq_restore(flags
);
6711 if (!mem_cgroup_is_root(ug
->memcg
))
6712 css_put_many(&ug
->memcg
->css
, nr_pages
);
6715 static void uncharge_page(struct page
*page
, struct uncharge_gather
*ug
)
6717 VM_BUG_ON_PAGE(PageLRU(page
), page
);
6718 VM_BUG_ON_PAGE(page_count(page
) && !is_zone_device_page(page
) &&
6719 !PageHWPoison(page
) , page
);
6721 if (!page
->mem_cgroup
)
6725 * Nobody should be changing or seriously looking at
6726 * page->mem_cgroup at this point, we have fully
6727 * exclusive access to the page.
6730 if (ug
->memcg
!= page
->mem_cgroup
) {
6733 uncharge_gather_clear(ug
);
6735 ug
->memcg
= page
->mem_cgroup
;
6738 if (!PageKmemcg(page
)) {
6739 unsigned int nr_pages
= 1;
6741 if (PageTransHuge(page
)) {
6742 nr_pages
= compound_nr(page
);
6743 ug
->nr_huge
+= nr_pages
;
6746 ug
->nr_anon
+= nr_pages
;
6748 ug
->nr_file
+= nr_pages
;
6749 if (PageSwapBacked(page
))
6750 ug
->nr_shmem
+= nr_pages
;
6754 ug
->nr_kmem
+= compound_nr(page
);
6755 __ClearPageKmemcg(page
);
6758 ug
->dummy_page
= page
;
6759 page
->mem_cgroup
= NULL
;
6762 static void uncharge_list(struct list_head
*page_list
)
6764 struct uncharge_gather ug
;
6765 struct list_head
*next
;
6767 uncharge_gather_clear(&ug
);
6770 * Note that the list can be a single page->lru; hence the
6771 * do-while loop instead of a simple list_for_each_entry().
6773 next
= page_list
->next
;
6777 page
= list_entry(next
, struct page
, lru
);
6778 next
= page
->lru
.next
;
6780 uncharge_page(page
, &ug
);
6781 } while (next
!= page_list
);
6784 uncharge_batch(&ug
);
6788 * mem_cgroup_uncharge - uncharge a page
6789 * @page: page to uncharge
6791 * Uncharge a page previously charged with mem_cgroup_try_charge() and
6792 * mem_cgroup_commit_charge().
6794 void mem_cgroup_uncharge(struct page
*page
)
6796 struct uncharge_gather ug
;
6798 if (mem_cgroup_disabled())
6801 /* Don't touch page->lru of any random page, pre-check: */
6802 if (!page
->mem_cgroup
)
6805 uncharge_gather_clear(&ug
);
6806 uncharge_page(page
, &ug
);
6807 uncharge_batch(&ug
);
6811 * mem_cgroup_uncharge_list - uncharge a list of page
6812 * @page_list: list of pages to uncharge
6814 * Uncharge a list of pages previously charged with
6815 * mem_cgroup_try_charge() and mem_cgroup_commit_charge().
6817 void mem_cgroup_uncharge_list(struct list_head
*page_list
)
6819 if (mem_cgroup_disabled())
6822 if (!list_empty(page_list
))
6823 uncharge_list(page_list
);
6827 * mem_cgroup_migrate - charge a page's replacement
6828 * @oldpage: currently circulating page
6829 * @newpage: replacement page
6831 * Charge @newpage as a replacement page for @oldpage. @oldpage will
6832 * be uncharged upon free.
6834 * Both pages must be locked, @newpage->mapping must be set up.
6836 void mem_cgroup_migrate(struct page
*oldpage
, struct page
*newpage
)
6838 struct mem_cgroup
*memcg
;
6839 unsigned int nr_pages
;
6841 unsigned long flags
;
6843 VM_BUG_ON_PAGE(!PageLocked(oldpage
), oldpage
);
6844 VM_BUG_ON_PAGE(!PageLocked(newpage
), newpage
);
6845 VM_BUG_ON_PAGE(PageAnon(oldpage
) != PageAnon(newpage
), newpage
);
6846 VM_BUG_ON_PAGE(PageTransHuge(oldpage
) != PageTransHuge(newpage
),
6849 if (mem_cgroup_disabled())
6852 /* Page cache replacement: new page already charged? */
6853 if (newpage
->mem_cgroup
)
6856 /* Swapcache readahead pages can get replaced before being charged */
6857 memcg
= oldpage
->mem_cgroup
;
6861 /* Force-charge the new page. The old one will be freed soon */
6862 compound
= PageTransHuge(newpage
);
6863 nr_pages
= compound
? hpage_nr_pages(newpage
) : 1;
6865 page_counter_charge(&memcg
->memory
, nr_pages
);
6866 if (do_memsw_account())
6867 page_counter_charge(&memcg
->memsw
, nr_pages
);
6868 css_get_many(&memcg
->css
, nr_pages
);
6870 commit_charge(newpage
, memcg
, false);
6872 local_irq_save(flags
);
6873 mem_cgroup_charge_statistics(memcg
, newpage
, compound
, nr_pages
);
6874 memcg_check_events(memcg
, newpage
);
6875 local_irq_restore(flags
);
6878 DEFINE_STATIC_KEY_FALSE(memcg_sockets_enabled_key
);
6879 EXPORT_SYMBOL(memcg_sockets_enabled_key
);
6881 void mem_cgroup_sk_alloc(struct sock
*sk
)
6883 struct mem_cgroup
*memcg
;
6885 if (!mem_cgroup_sockets_enabled
)
6888 /* Do not associate the sock with unrelated interrupted task's memcg. */
6893 memcg
= mem_cgroup_from_task(current
);
6894 if (memcg
== root_mem_cgroup
)
6896 if (!cgroup_subsys_on_dfl(memory_cgrp_subsys
) && !memcg
->tcpmem_active
)
6898 if (css_tryget_online(&memcg
->css
))
6899 sk
->sk_memcg
= memcg
;
6904 void mem_cgroup_sk_free(struct sock
*sk
)
6907 css_put(&sk
->sk_memcg
->css
);
6911 * mem_cgroup_charge_skmem - charge socket memory
6912 * @memcg: memcg to charge
6913 * @nr_pages: number of pages to charge
6915 * Charges @nr_pages to @memcg. Returns %true if the charge fit within
6916 * @memcg's configured limit, %false if the charge had to be forced.
6918 bool mem_cgroup_charge_skmem(struct mem_cgroup
*memcg
, unsigned int nr_pages
)
6920 gfp_t gfp_mask
= GFP_KERNEL
;
6922 if (!cgroup_subsys_on_dfl(memory_cgrp_subsys
)) {
6923 struct page_counter
*fail
;
6925 if (page_counter_try_charge(&memcg
->tcpmem
, nr_pages
, &fail
)) {
6926 memcg
->tcpmem_pressure
= 0;
6929 page_counter_charge(&memcg
->tcpmem
, nr_pages
);
6930 memcg
->tcpmem_pressure
= 1;
6934 /* Don't block in the packet receive path */
6936 gfp_mask
= GFP_NOWAIT
;
6938 mod_memcg_state(memcg
, MEMCG_SOCK
, nr_pages
);
6940 if (try_charge(memcg
, gfp_mask
, nr_pages
) == 0)
6943 try_charge(memcg
, gfp_mask
|__GFP_NOFAIL
, nr_pages
);
6948 * mem_cgroup_uncharge_skmem - uncharge socket memory
6949 * @memcg: memcg to uncharge
6950 * @nr_pages: number of pages to uncharge
6952 void mem_cgroup_uncharge_skmem(struct mem_cgroup
*memcg
, unsigned int nr_pages
)
6954 if (!cgroup_subsys_on_dfl(memory_cgrp_subsys
)) {
6955 page_counter_uncharge(&memcg
->tcpmem
, nr_pages
);
6959 mod_memcg_state(memcg
, MEMCG_SOCK
, -nr_pages
);
6961 refill_stock(memcg
, nr_pages
);
6964 static int __init
cgroup_memory(char *s
)
6968 while ((token
= strsep(&s
, ",")) != NULL
) {
6971 if (!strcmp(token
, "nosocket"))
6972 cgroup_memory_nosocket
= true;
6973 if (!strcmp(token
, "nokmem"))
6974 cgroup_memory_nokmem
= true;
6978 __setup("cgroup.memory=", cgroup_memory
);
6981 * subsys_initcall() for memory controller.
6983 * Some parts like memcg_hotplug_cpu_dead() have to be initialized from this
6984 * context because of lock dependencies (cgroup_lock -> cpu hotplug) but
6985 * basically everything that doesn't depend on a specific mem_cgroup structure
6986 * should be initialized from here.
6988 static int __init
mem_cgroup_init(void)
6992 #ifdef CONFIG_MEMCG_KMEM
6994 * Kmem cache creation is mostly done with the slab_mutex held,
6995 * so use a workqueue with limited concurrency to avoid stalling
6996 * all worker threads in case lots of cgroups are created and
6997 * destroyed simultaneously.
6999 memcg_kmem_cache_wq
= alloc_workqueue("memcg_kmem_cache", 0, 1);
7000 BUG_ON(!memcg_kmem_cache_wq
);
7003 cpuhp_setup_state_nocalls(CPUHP_MM_MEMCQ_DEAD
, "mm/memctrl:dead", NULL
,
7004 memcg_hotplug_cpu_dead
);
7006 for_each_possible_cpu(cpu
)
7007 INIT_WORK(&per_cpu_ptr(&memcg_stock
, cpu
)->work
,
7010 for_each_node(node
) {
7011 struct mem_cgroup_tree_per_node
*rtpn
;
7013 rtpn
= kzalloc_node(sizeof(*rtpn
), GFP_KERNEL
,
7014 node_online(node
) ? node
: NUMA_NO_NODE
);
7016 rtpn
->rb_root
= RB_ROOT
;
7017 rtpn
->rb_rightmost
= NULL
;
7018 spin_lock_init(&rtpn
->lock
);
7019 soft_limit_tree
.rb_tree_per_node
[node
] = rtpn
;
7024 subsys_initcall(mem_cgroup_init
);
7026 #ifdef CONFIG_MEMCG_SWAP
7027 static struct mem_cgroup
*mem_cgroup_id_get_online(struct mem_cgroup
*memcg
)
7029 while (!refcount_inc_not_zero(&memcg
->id
.ref
)) {
7031 * The root cgroup cannot be destroyed, so it's refcount must
7034 if (WARN_ON_ONCE(memcg
== root_mem_cgroup
)) {
7038 memcg
= parent_mem_cgroup(memcg
);
7040 memcg
= root_mem_cgroup
;
7046 * mem_cgroup_swapout - transfer a memsw charge to swap
7047 * @page: page whose memsw charge to transfer
7048 * @entry: swap entry to move the charge to
7050 * Transfer the memsw charge of @page to @entry.
7052 void mem_cgroup_swapout(struct page
*page
, swp_entry_t entry
)
7054 struct mem_cgroup
*memcg
, *swap_memcg
;
7055 unsigned int nr_entries
;
7056 unsigned short oldid
;
7058 VM_BUG_ON_PAGE(PageLRU(page
), page
);
7059 VM_BUG_ON_PAGE(page_count(page
), page
);
7061 if (!do_memsw_account())
7064 memcg
= page
->mem_cgroup
;
7066 /* Readahead page, never charged */
7071 * In case the memcg owning these pages has been offlined and doesn't
7072 * have an ID allocated to it anymore, charge the closest online
7073 * ancestor for the swap instead and transfer the memory+swap charge.
7075 swap_memcg
= mem_cgroup_id_get_online(memcg
);
7076 nr_entries
= hpage_nr_pages(page
);
7077 /* Get references for the tail pages, too */
7079 mem_cgroup_id_get_many(swap_memcg
, nr_entries
- 1);
7080 oldid
= swap_cgroup_record(entry
, mem_cgroup_id(swap_memcg
),
7082 VM_BUG_ON_PAGE(oldid
, page
);
7083 mod_memcg_state(swap_memcg
, MEMCG_SWAP
, nr_entries
);
7085 page
->mem_cgroup
= NULL
;
7087 if (!mem_cgroup_is_root(memcg
))
7088 page_counter_uncharge(&memcg
->memory
, nr_entries
);
7090 if (memcg
!= swap_memcg
) {
7091 if (!mem_cgroup_is_root(swap_memcg
))
7092 page_counter_charge(&swap_memcg
->memsw
, nr_entries
);
7093 page_counter_uncharge(&memcg
->memsw
, nr_entries
);
7097 * Interrupts should be disabled here because the caller holds the
7098 * i_pages lock which is taken with interrupts-off. It is
7099 * important here to have the interrupts disabled because it is the
7100 * only synchronisation we have for updating the per-CPU variables.
7102 VM_BUG_ON(!irqs_disabled());
7103 mem_cgroup_charge_statistics(memcg
, page
, PageTransHuge(page
),
7105 memcg_check_events(memcg
, page
);
7107 if (!mem_cgroup_is_root(memcg
))
7108 css_put_many(&memcg
->css
, nr_entries
);
7112 * mem_cgroup_try_charge_swap - try charging swap space for a page
7113 * @page: page being added to swap
7114 * @entry: swap entry to charge
7116 * Try to charge @page's memcg for the swap space at @entry.
7118 * Returns 0 on success, -ENOMEM on failure.
7120 int mem_cgroup_try_charge_swap(struct page
*page
, swp_entry_t entry
)
7122 unsigned int nr_pages
= hpage_nr_pages(page
);
7123 struct page_counter
*counter
;
7124 struct mem_cgroup
*memcg
;
7125 unsigned short oldid
;
7127 if (!cgroup_subsys_on_dfl(memory_cgrp_subsys
) || !do_swap_account
)
7130 memcg
= page
->mem_cgroup
;
7132 /* Readahead page, never charged */
7137 memcg_memory_event(memcg
, MEMCG_SWAP_FAIL
);
7141 memcg
= mem_cgroup_id_get_online(memcg
);
7143 if (!mem_cgroup_is_root(memcg
) &&
7144 !page_counter_try_charge(&memcg
->swap
, nr_pages
, &counter
)) {
7145 memcg_memory_event(memcg
, MEMCG_SWAP_MAX
);
7146 memcg_memory_event(memcg
, MEMCG_SWAP_FAIL
);
7147 mem_cgroup_id_put(memcg
);
7151 /* Get references for the tail pages, too */
7153 mem_cgroup_id_get_many(memcg
, nr_pages
- 1);
7154 oldid
= swap_cgroup_record(entry
, mem_cgroup_id(memcg
), nr_pages
);
7155 VM_BUG_ON_PAGE(oldid
, page
);
7156 mod_memcg_state(memcg
, MEMCG_SWAP
, nr_pages
);
7162 * mem_cgroup_uncharge_swap - uncharge swap space
7163 * @entry: swap entry to uncharge
7164 * @nr_pages: the amount of swap space to uncharge
7166 void mem_cgroup_uncharge_swap(swp_entry_t entry
, unsigned int nr_pages
)
7168 struct mem_cgroup
*memcg
;
7171 if (!do_swap_account
)
7174 id
= swap_cgroup_record(entry
, 0, nr_pages
);
7176 memcg
= mem_cgroup_from_id(id
);
7178 if (!mem_cgroup_is_root(memcg
)) {
7179 if (cgroup_subsys_on_dfl(memory_cgrp_subsys
))
7180 page_counter_uncharge(&memcg
->swap
, nr_pages
);
7182 page_counter_uncharge(&memcg
->memsw
, nr_pages
);
7184 mod_memcg_state(memcg
, MEMCG_SWAP
, -nr_pages
);
7185 mem_cgroup_id_put_many(memcg
, nr_pages
);
7190 long mem_cgroup_get_nr_swap_pages(struct mem_cgroup
*memcg
)
7192 long nr_swap_pages
= get_nr_swap_pages();
7194 if (!do_swap_account
|| !cgroup_subsys_on_dfl(memory_cgrp_subsys
))
7195 return nr_swap_pages
;
7196 for (; memcg
!= root_mem_cgroup
; memcg
= parent_mem_cgroup(memcg
))
7197 nr_swap_pages
= min_t(long, nr_swap_pages
,
7198 READ_ONCE(memcg
->swap
.max
) -
7199 page_counter_read(&memcg
->swap
));
7200 return nr_swap_pages
;
7203 bool mem_cgroup_swap_full(struct page
*page
)
7205 struct mem_cgroup
*memcg
;
7207 VM_BUG_ON_PAGE(!PageLocked(page
), page
);
7211 if (!do_swap_account
|| !cgroup_subsys_on_dfl(memory_cgrp_subsys
))
7214 memcg
= page
->mem_cgroup
;
7218 for (; memcg
!= root_mem_cgroup
; memcg
= parent_mem_cgroup(memcg
))
7219 if (page_counter_read(&memcg
->swap
) * 2 >= memcg
->swap
.max
)
7225 /* for remember boot option*/
7226 #ifdef CONFIG_MEMCG_SWAP_ENABLED
7227 static int really_do_swap_account __initdata
= 1;
7229 static int really_do_swap_account __initdata
;
7232 static int __init
enable_swap_account(char *s
)
7234 if (!strcmp(s
, "1"))
7235 really_do_swap_account
= 1;
7236 else if (!strcmp(s
, "0"))
7237 really_do_swap_account
= 0;
7240 __setup("swapaccount=", enable_swap_account
);
7242 static u64
swap_current_read(struct cgroup_subsys_state
*css
,
7245 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
7247 return (u64
)page_counter_read(&memcg
->swap
) * PAGE_SIZE
;
7250 static int swap_max_show(struct seq_file
*m
, void *v
)
7252 return seq_puts_memcg_tunable(m
,
7253 READ_ONCE(mem_cgroup_from_seq(m
)->swap
.max
));
7256 static ssize_t
swap_max_write(struct kernfs_open_file
*of
,
7257 char *buf
, size_t nbytes
, loff_t off
)
7259 struct mem_cgroup
*memcg
= mem_cgroup_from_css(of_css(of
));
7263 buf
= strstrip(buf
);
7264 err
= page_counter_memparse(buf
, "max", &max
);
7268 xchg(&memcg
->swap
.max
, max
);
7273 static int swap_events_show(struct seq_file
*m
, void *v
)
7275 struct mem_cgroup
*memcg
= mem_cgroup_from_seq(m
);
7277 seq_printf(m
, "max %lu\n",
7278 atomic_long_read(&memcg
->memory_events
[MEMCG_SWAP_MAX
]));
7279 seq_printf(m
, "fail %lu\n",
7280 atomic_long_read(&memcg
->memory_events
[MEMCG_SWAP_FAIL
]));
7285 static struct cftype swap_files
[] = {
7287 .name
= "swap.current",
7288 .flags
= CFTYPE_NOT_ON_ROOT
,
7289 .read_u64
= swap_current_read
,
7293 .flags
= CFTYPE_NOT_ON_ROOT
,
7294 .seq_show
= swap_max_show
,
7295 .write
= swap_max_write
,
7298 .name
= "swap.events",
7299 .flags
= CFTYPE_NOT_ON_ROOT
,
7300 .file_offset
= offsetof(struct mem_cgroup
, swap_events_file
),
7301 .seq_show
= swap_events_show
,
7306 static struct cftype memsw_cgroup_files
[] = {
7308 .name
= "memsw.usage_in_bytes",
7309 .private = MEMFILE_PRIVATE(_MEMSWAP
, RES_USAGE
),
7310 .read_u64
= mem_cgroup_read_u64
,
7313 .name
= "memsw.max_usage_in_bytes",
7314 .private = MEMFILE_PRIVATE(_MEMSWAP
, RES_MAX_USAGE
),
7315 .write
= mem_cgroup_reset
,
7316 .read_u64
= mem_cgroup_read_u64
,
7319 .name
= "memsw.limit_in_bytes",
7320 .private = MEMFILE_PRIVATE(_MEMSWAP
, RES_LIMIT
),
7321 .write
= mem_cgroup_write
,
7322 .read_u64
= mem_cgroup_read_u64
,
7325 .name
= "memsw.failcnt",
7326 .private = MEMFILE_PRIVATE(_MEMSWAP
, RES_FAILCNT
),
7327 .write
= mem_cgroup_reset
,
7328 .read_u64
= mem_cgroup_read_u64
,
7330 { }, /* terminate */
7333 static int __init
mem_cgroup_swap_init(void)
7335 if (!mem_cgroup_disabled() && really_do_swap_account
) {
7336 do_swap_account
= 1;
7337 WARN_ON(cgroup_add_dfl_cftypes(&memory_cgrp_subsys
,
7339 WARN_ON(cgroup_add_legacy_cftypes(&memory_cgrp_subsys
,
7340 memsw_cgroup_files
));
7344 subsys_initcall(mem_cgroup_swap_init
);
7346 #endif /* CONFIG_MEMCG_SWAP */