1 /* memcontrol.c - Memory Controller
3 * Copyright IBM Corporation, 2007
4 * Author Balbir Singh <balbir@linux.vnet.ibm.com>
6 * Copyright 2007 OpenVZ SWsoft Inc
7 * Author: Pavel Emelianov <xemul@openvz.org>
10 * Copyright (C) 2009 Nokia Corporation
11 * Author: Kirill A. Shutemov
13 * Kernel Memory Controller
14 * Copyright (C) 2012 Parallels Inc. and Google Inc.
15 * Authors: Glauber Costa and Suleiman Souhlal
18 * Charge lifetime sanitation
19 * Lockless page tracking & accounting
20 * Unified hierarchy configuration model
21 * Copyright (C) 2015 Red Hat, Inc., Johannes Weiner
23 * This program is free software; you can redistribute it and/or modify
24 * it under the terms of the GNU General Public License as published by
25 * the Free Software Foundation; either version 2 of the License, or
26 * (at your option) any later version.
28 * This program is distributed in the hope that it will be useful,
29 * but WITHOUT ANY WARRANTY; without even the implied warranty of
30 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
31 * GNU General Public License for more details.
34 #include <linux/page_counter.h>
35 #include <linux/memcontrol.h>
36 #include <linux/cgroup.h>
38 #include <linux/hugetlb.h>
39 #include <linux/pagemap.h>
40 #include <linux/smp.h>
41 #include <linux/page-flags.h>
42 #include <linux/backing-dev.h>
43 #include <linux/bit_spinlock.h>
44 #include <linux/rcupdate.h>
45 #include <linux/limits.h>
46 #include <linux/export.h>
47 #include <linux/mutex.h>
48 #include <linux/rbtree.h>
49 #include <linux/slab.h>
50 #include <linux/swap.h>
51 #include <linux/swapops.h>
52 #include <linux/spinlock.h>
53 #include <linux/eventfd.h>
54 #include <linux/poll.h>
55 #include <linux/sort.h>
57 #include <linux/seq_file.h>
58 #include <linux/vmpressure.h>
59 #include <linux/mm_inline.h>
60 #include <linux/swap_cgroup.h>
61 #include <linux/cpu.h>
62 #include <linux/oom.h>
63 #include <linux/lockdep.h>
64 #include <linux/file.h>
65 #include <linux/tracehook.h>
71 #include <asm/uaccess.h>
73 #include <trace/events/vmscan.h>
75 struct cgroup_subsys memory_cgrp_subsys __read_mostly;
76 EXPORT_SYMBOL(memory_cgrp_subsys);
78 struct mem_cgroup *root_mem_cgroup __read_mostly;
80 #define MEM_CGROUP_RECLAIM_RETRIES 5
82 /* Socket memory accounting disabled? */
83 static bool cgroup_memory_nosocket;
85 /* Kernel memory accounting disabled? */
86 static bool cgroup_memory_nokmem;
88 /* Whether the swap controller is active */
89 #ifdef CONFIG_MEMCG_SWAP
90 int do_swap_account __read_mostly;
92 #define do_swap_account 0
95 /* Whether legacy memory+swap accounting is active */
96 static bool do_memsw_account(void)
98 return !cgroup_subsys_on_dfl(memory_cgrp_subsys) && do_swap_account;
101 static const char * const mem_cgroup_stat_names[] = {
111 static const char * const mem_cgroup_events_names[] = {
118 static const char * const mem_cgroup_lru_names[] = {
126 #define THRESHOLDS_EVENTS_TARGET 128
127 #define SOFTLIMIT_EVENTS_TARGET 1024
128 #define NUMAINFO_EVENTS_TARGET 1024
131 * Cgroups above their limits are maintained in a RB-Tree, independent of
132 * their hierarchy representation
135 struct mem_cgroup_tree_per_zone {
136 struct rb_root rb_root;
140 struct mem_cgroup_tree_per_node {
141 struct mem_cgroup_tree_per_zone rb_tree_per_zone[MAX_NR_ZONES];
144 struct mem_cgroup_tree {
145 struct mem_cgroup_tree_per_node *rb_tree_per_node[MAX_NUMNODES];
148 static struct mem_cgroup_tree soft_limit_tree __read_mostly;
151 struct mem_cgroup_eventfd_list {
152 struct list_head list;
153 struct eventfd_ctx *eventfd;
157 * cgroup_event represents events which userspace want to receive.
159 struct mem_cgroup_event {
161 * memcg which the event belongs to.
163 struct mem_cgroup *memcg;
165 * eventfd to signal userspace about the event.
167 struct eventfd_ctx *eventfd;
169 * Each of these stored in a list by the cgroup.
171 struct list_head list;
173 * register_event() callback will be used to add new userspace
174 * waiter for changes related to this event. Use eventfd_signal()
175 * on eventfd to send notification to userspace.
177 int (*register_event)(struct mem_cgroup *memcg,
178 struct eventfd_ctx *eventfd, const char *args);
180 * unregister_event() callback will be called when userspace closes
181 * the eventfd or on cgroup removing. This callback must be set,
182 * if you want provide notification functionality.
184 void (*unregister_event)(struct mem_cgroup *memcg,
185 struct eventfd_ctx *eventfd);
187 * All fields below needed to unregister event when
188 * userspace closes eventfd.
191 wait_queue_head_t *wqh;
193 struct work_struct remove;
196 static void mem_cgroup_threshold(struct mem_cgroup *memcg);
197 static void mem_cgroup_oom_notify(struct mem_cgroup *memcg);
199 /* Stuffs for move charges at task migration. */
201 * Types of charges to be moved.
203 #define MOVE_ANON 0x1U
204 #define MOVE_FILE 0x2U
205 #define MOVE_MASK (MOVE_ANON | MOVE_FILE)
207 /* "mc" and its members are protected by cgroup_mutex */
208 static struct move_charge_struct {
209 spinlock_t lock; /* for from, to */
210 struct mem_cgroup *from;
211 struct mem_cgroup *to;
213 unsigned long precharge;
214 unsigned long moved_charge;
215 unsigned long moved_swap;
216 struct task_struct *moving_task; /* a task moving charges */
217 wait_queue_head_t waitq; /* a waitq for other context */
219 .lock = __SPIN_LOCK_UNLOCKED(mc.lock),
220 .waitq = __WAIT_QUEUE_HEAD_INITIALIZER(mc.waitq),
224 * Maximum loops in mem_cgroup_hierarchical_reclaim(), used for soft
225 * limit reclaim to prevent infinite loops, if they ever occur.
227 #define MEM_CGROUP_MAX_RECLAIM_LOOPS 100
228 #define MEM_CGROUP_MAX_SOFT_LIMIT_RECLAIM_LOOPS 2
231 MEM_CGROUP_CHARGE_TYPE_CACHE = 0,
232 MEM_CGROUP_CHARGE_TYPE_ANON,
233 MEM_CGROUP_CHARGE_TYPE_SWAPOUT, /* for accounting swapcache */
234 MEM_CGROUP_CHARGE_TYPE_DROP, /* a page was unused swap cache */
238 /* for encoding cft->private value on file */
247 #define MEMFILE_PRIVATE(x, val) ((x) << 16 | (val))
248 #define MEMFILE_TYPE(val) ((val) >> 16 & 0xffff)
249 #define MEMFILE_ATTR(val) ((val) & 0xffff)
250 /* Used for OOM nofiier */
251 #define OOM_CONTROL (0)
253 /* Some nice accessors for the vmpressure. */
254 struct vmpressure *memcg_to_vmpressure(struct mem_cgroup *memcg)
257 memcg = root_mem_cgroup;
258 return &memcg->vmpressure;
261 struct cgroup_subsys_state *vmpressure_to_css(struct vmpressure *vmpr)
263 return &container_of(vmpr, struct mem_cgroup, vmpressure)->css;
266 static inline bool mem_cgroup_is_root(struct mem_cgroup *memcg)
268 return (memcg == root_mem_cgroup);
273 * This will be the memcg's index in each cache's ->memcg_params.memcg_caches.
274 * The main reason for not using cgroup id for this:
275 * this works better in sparse environments, where we have a lot of memcgs,
276 * but only a few kmem-limited. Or also, if we have, for instance, 200
277 * memcgs, and none but the 200th is kmem-limited, we'd have to have a
278 * 200 entry array for that.
280 * The current size of the caches array is stored in memcg_nr_cache_ids. It
281 * will double each time we have to increase it.
283 static DEFINE_IDA(memcg_cache_ida);
284 int memcg_nr_cache_ids;
286 /* Protects memcg_nr_cache_ids */
287 static DECLARE_RWSEM(memcg_cache_ids_sem);
289 void memcg_get_cache_ids(void)
291 down_read(&memcg_cache_ids_sem);
294 void memcg_put_cache_ids(void)
296 up_read(&memcg_cache_ids_sem);
300 * MIN_SIZE is different than 1, because we would like to avoid going through
301 * the alloc/free process all the time. In a small machine, 4 kmem-limited
302 * cgroups is a reasonable guess. In the future, it could be a parameter or
303 * tunable, but that is strictly not necessary.
305 * MAX_SIZE should be as large as the number of cgrp_ids. Ideally, we could get
306 * this constant directly from cgroup, but it is understandable that this is
307 * better kept as an internal representation in cgroup.c. In any case, the
308 * cgrp_id space is not getting any smaller, and we don't have to necessarily
309 * increase ours as well if it increases.
311 #define MEMCG_CACHES_MIN_SIZE 4
312 #define MEMCG_CACHES_MAX_SIZE MEM_CGROUP_ID_MAX
315 * A lot of the calls to the cache allocation functions are expected to be
316 * inlined by the compiler. Since the calls to memcg_kmem_get_cache are
317 * conditional to this static branch, we'll have to allow modules that does
318 * kmem_cache_alloc and the such to see this symbol as well
320 DEFINE_STATIC_KEY_FALSE(memcg_kmem_enabled_key);
321 EXPORT_SYMBOL(memcg_kmem_enabled_key);
323 #endif /* !CONFIG_SLOB */
325 static struct mem_cgroup_per_zone *
326 mem_cgroup_zone_zoneinfo(struct mem_cgroup *memcg, struct zone *zone)
328 int nid = zone_to_nid(zone);
329 int zid = zone_idx(zone);
331 return &memcg->nodeinfo[nid]->zoneinfo[zid];
335 * mem_cgroup_css_from_page - css of the memcg associated with a page
336 * @page: page of interest
338 * If memcg is bound to the default hierarchy, css of the memcg associated
339 * with @page is returned. The returned css remains associated with @page
340 * until it is released.
342 * If memcg is bound to a traditional hierarchy, the css of root_mem_cgroup
345 struct cgroup_subsys_state *mem_cgroup_css_from_page(struct page *page)
347 struct mem_cgroup *memcg;
349 memcg = page->mem_cgroup;
351 if (!memcg || !cgroup_subsys_on_dfl(memory_cgrp_subsys))
352 memcg = root_mem_cgroup;
358 * page_cgroup_ino - return inode number of the memcg a page is charged to
361 * Look up the closest online ancestor of the memory cgroup @page is charged to
362 * and return its inode number or 0 if @page is not charged to any cgroup. It
363 * is safe to call this function without holding a reference to @page.
365 * Note, this function is inherently racy, because there is nothing to prevent
366 * the cgroup inode from getting torn down and potentially reallocated a moment
367 * after page_cgroup_ino() returns, so it only should be used by callers that
368 * do not care (such as procfs interfaces).
370 ino_t page_cgroup_ino(struct page *page)
372 struct mem_cgroup *memcg;
373 unsigned long ino = 0;
376 memcg = READ_ONCE(page->mem_cgroup);
377 while (memcg && !(memcg->css.flags & CSS_ONLINE))
378 memcg = parent_mem_cgroup(memcg);
380 ino = cgroup_ino(memcg->css.cgroup);
385 static struct mem_cgroup_per_zone *
386 mem_cgroup_page_zoneinfo(struct mem_cgroup *memcg, struct page *page)
388 int nid = page_to_nid(page);
389 int zid = page_zonenum(page);
391 return &memcg->nodeinfo[nid]->zoneinfo[zid];
394 static struct mem_cgroup_tree_per_zone *
395 soft_limit_tree_node_zone(int nid, int zid)
397 return &soft_limit_tree.rb_tree_per_node[nid]->rb_tree_per_zone[zid];
400 static struct mem_cgroup_tree_per_zone *
401 soft_limit_tree_from_page(struct page *page)
403 int nid = page_to_nid(page);
404 int zid = page_zonenum(page);
406 return &soft_limit_tree.rb_tree_per_node[nid]->rb_tree_per_zone[zid];
409 static void __mem_cgroup_insert_exceeded(struct mem_cgroup_per_zone *mz,
410 struct mem_cgroup_tree_per_zone *mctz,
411 unsigned long new_usage_in_excess)
413 struct rb_node **p = &mctz->rb_root.rb_node;
414 struct rb_node *parent = NULL;
415 struct mem_cgroup_per_zone *mz_node;
420 mz->usage_in_excess = new_usage_in_excess;
421 if (!mz->usage_in_excess)
425 mz_node = rb_entry(parent, struct mem_cgroup_per_zone,
427 if (mz->usage_in_excess < mz_node->usage_in_excess)
430 * We can't avoid mem cgroups that are over their soft
431 * limit by the same amount
433 else if (mz->usage_in_excess >= mz_node->usage_in_excess)
436 rb_link_node(&mz->tree_node, parent, p);
437 rb_insert_color(&mz->tree_node, &mctz->rb_root);
441 static void __mem_cgroup_remove_exceeded(struct mem_cgroup_per_zone *mz,
442 struct mem_cgroup_tree_per_zone *mctz)
446 rb_erase(&mz->tree_node, &mctz->rb_root);
450 static void mem_cgroup_remove_exceeded(struct mem_cgroup_per_zone *mz,
451 struct mem_cgroup_tree_per_zone *mctz)
455 spin_lock_irqsave(&mctz->lock, flags);
456 __mem_cgroup_remove_exceeded(mz, mctz);
457 spin_unlock_irqrestore(&mctz->lock, flags);
460 static unsigned long soft_limit_excess(struct mem_cgroup *memcg)
462 unsigned long nr_pages = page_counter_read(&memcg->memory);
463 unsigned long soft_limit = READ_ONCE(memcg->soft_limit);
464 unsigned long excess = 0;
466 if (nr_pages > soft_limit)
467 excess = nr_pages - soft_limit;
472 static void mem_cgroup_update_tree(struct mem_cgroup *memcg, struct page *page)
474 unsigned long excess;
475 struct mem_cgroup_per_zone *mz;
476 struct mem_cgroup_tree_per_zone *mctz;
478 mctz = soft_limit_tree_from_page(page);
480 * Necessary to update all ancestors when hierarchy is used.
481 * because their event counter is not touched.
483 for (; memcg; memcg = parent_mem_cgroup(memcg)) {
484 mz = mem_cgroup_page_zoneinfo(memcg, page);
485 excess = soft_limit_excess(memcg);
487 * We have to update the tree if mz is on RB-tree or
488 * mem is over its softlimit.
490 if (excess || mz->on_tree) {
493 spin_lock_irqsave(&mctz->lock, flags);
494 /* if on-tree, remove it */
496 __mem_cgroup_remove_exceeded(mz, mctz);
498 * Insert again. mz->usage_in_excess will be updated.
499 * If excess is 0, no tree ops.
501 __mem_cgroup_insert_exceeded(mz, mctz, excess);
502 spin_unlock_irqrestore(&mctz->lock, flags);
507 static void mem_cgroup_remove_from_trees(struct mem_cgroup *memcg)
509 struct mem_cgroup_tree_per_zone *mctz;
510 struct mem_cgroup_per_zone *mz;
514 for (zid = 0; zid < MAX_NR_ZONES; zid++) {
515 mz = &memcg->nodeinfo[nid]->zoneinfo[zid];
516 mctz = soft_limit_tree_node_zone(nid, zid);
517 mem_cgroup_remove_exceeded(mz, mctz);
522 static struct mem_cgroup_per_zone *
523 __mem_cgroup_largest_soft_limit_node(struct mem_cgroup_tree_per_zone *mctz)
525 struct rb_node *rightmost = NULL;
526 struct mem_cgroup_per_zone *mz;
530 rightmost = rb_last(&mctz->rb_root);
532 goto done; /* Nothing to reclaim from */
534 mz = rb_entry(rightmost, struct mem_cgroup_per_zone, tree_node);
536 * Remove the node now but someone else can add it back,
537 * we will to add it back at the end of reclaim to its correct
538 * position in the tree.
540 __mem_cgroup_remove_exceeded(mz, mctz);
541 if (!soft_limit_excess(mz->memcg) ||
542 !css_tryget_online(&mz->memcg->css))
548 static struct mem_cgroup_per_zone *
549 mem_cgroup_largest_soft_limit_node(struct mem_cgroup_tree_per_zone *mctz)
551 struct mem_cgroup_per_zone *mz;
553 spin_lock_irq(&mctz->lock);
554 mz = __mem_cgroup_largest_soft_limit_node(mctz);
555 spin_unlock_irq(&mctz->lock);
560 * Return page count for single (non recursive) @memcg.
562 * Implementation Note: reading percpu statistics for memcg.
564 * Both of vmstat[] and percpu_counter has threshold and do periodic
565 * synchronization to implement "quick" read. There are trade-off between
566 * reading cost and precision of value. Then, we may have a chance to implement
567 * a periodic synchronization of counter in memcg's counter.
569 * But this _read() function is used for user interface now. The user accounts
570 * memory usage by memory cgroup and he _always_ requires exact value because
571 * he accounts memory. Even if we provide quick-and-fuzzy read, we always
572 * have to visit all online cpus and make sum. So, for now, unnecessary
573 * synchronization is not implemented. (just implemented for cpu hotplug)
575 * If there are kernel internal actions which can make use of some not-exact
576 * value, and reading all cpu value can be performance bottleneck in some
577 * common workload, threshold and synchronization as vmstat[] should be
581 mem_cgroup_read_stat(struct mem_cgroup *memcg, enum mem_cgroup_stat_index idx)
586 /* Per-cpu values can be negative, use a signed accumulator */
587 for_each_possible_cpu(cpu)
588 val += per_cpu(memcg->stat->count[idx], cpu);
590 * Summing races with updates, so val may be negative. Avoid exposing
591 * transient negative values.
598 static unsigned long mem_cgroup_read_events(struct mem_cgroup *memcg,
599 enum mem_cgroup_events_index idx)
601 unsigned long val = 0;
604 for_each_possible_cpu(cpu)
605 val += per_cpu(memcg->stat->events[idx], cpu);
609 static void mem_cgroup_charge_statistics(struct mem_cgroup *memcg,
611 bool compound, int nr_pages)
614 * Here, RSS means 'mapped anon' and anon's SwapCache. Shmem/tmpfs is
615 * counted as CACHE even if it's on ANON LRU.
618 __this_cpu_add(memcg->stat->count[MEM_CGROUP_STAT_RSS],
621 __this_cpu_add(memcg->stat->count[MEM_CGROUP_STAT_CACHE],
625 VM_BUG_ON_PAGE(!PageTransHuge(page), page);
626 __this_cpu_add(memcg->stat->count[MEM_CGROUP_STAT_RSS_HUGE],
630 /* pagein of a big page is an event. So, ignore page size */
632 __this_cpu_inc(memcg->stat->events[MEM_CGROUP_EVENTS_PGPGIN]);
634 __this_cpu_inc(memcg->stat->events[MEM_CGROUP_EVENTS_PGPGOUT]);
635 nr_pages = -nr_pages; /* for event */
638 __this_cpu_add(memcg->stat->nr_page_events, nr_pages);
641 unsigned long mem_cgroup_node_nr_lru_pages(struct mem_cgroup *memcg,
642 int nid, unsigned int lru_mask)
644 unsigned long nr = 0;
647 VM_BUG_ON((unsigned)nid >= nr_node_ids);
649 for (zid = 0; zid < MAX_NR_ZONES; zid++) {
650 struct mem_cgroup_per_zone *mz;
654 if (!(BIT(lru) & lru_mask))
656 mz = &memcg->nodeinfo[nid]->zoneinfo[zid];
657 nr += mz->lru_size[lru];
663 static unsigned long mem_cgroup_nr_lru_pages(struct mem_cgroup *memcg,
664 unsigned int lru_mask)
666 unsigned long nr = 0;
669 for_each_node_state(nid, N_MEMORY)
670 nr += mem_cgroup_node_nr_lru_pages(memcg, nid, lru_mask);
674 static bool mem_cgroup_event_ratelimit(struct mem_cgroup *memcg,
675 enum mem_cgroup_events_target target)
677 unsigned long val, next;
679 val = __this_cpu_read(memcg->stat->nr_page_events);
680 next = __this_cpu_read(memcg->stat->targets[target]);
681 /* from time_after() in jiffies.h */
682 if ((long)next - (long)val < 0) {
684 case MEM_CGROUP_TARGET_THRESH:
685 next = val + THRESHOLDS_EVENTS_TARGET;
687 case MEM_CGROUP_TARGET_SOFTLIMIT:
688 next = val + SOFTLIMIT_EVENTS_TARGET;
690 case MEM_CGROUP_TARGET_NUMAINFO:
691 next = val + NUMAINFO_EVENTS_TARGET;
696 __this_cpu_write(memcg->stat->targets[target], next);
703 * Check events in order.
706 static void memcg_check_events(struct mem_cgroup *memcg, struct page *page)
708 /* threshold event is triggered in finer grain than soft limit */
709 if (unlikely(mem_cgroup_event_ratelimit(memcg,
710 MEM_CGROUP_TARGET_THRESH))) {
712 bool do_numainfo __maybe_unused;
714 do_softlimit = mem_cgroup_event_ratelimit(memcg,
715 MEM_CGROUP_TARGET_SOFTLIMIT);
717 do_numainfo = mem_cgroup_event_ratelimit(memcg,
718 MEM_CGROUP_TARGET_NUMAINFO);
720 mem_cgroup_threshold(memcg);
721 if (unlikely(do_softlimit))
722 mem_cgroup_update_tree(memcg, page);
724 if (unlikely(do_numainfo))
725 atomic_inc(&memcg->numainfo_events);
730 struct mem_cgroup *mem_cgroup_from_task(struct task_struct *p)
733 * mm_update_next_owner() may clear mm->owner to NULL
734 * if it races with swapoff, page migration, etc.
735 * So this can be called with p == NULL.
740 return mem_cgroup_from_css(task_css(p, memory_cgrp_id));
742 EXPORT_SYMBOL(mem_cgroup_from_task);
744 static struct mem_cgroup *get_mem_cgroup_from_mm(struct mm_struct *mm)
746 struct mem_cgroup *memcg = NULL;
751 * Page cache insertions can happen withou an
752 * actual mm context, e.g. during disk probing
753 * on boot, loopback IO, acct() writes etc.
756 memcg = root_mem_cgroup;
758 memcg = mem_cgroup_from_task(rcu_dereference(mm->owner));
759 if (unlikely(!memcg))
760 memcg = root_mem_cgroup;
762 } while (!css_tryget_online(&memcg->css));
768 * mem_cgroup_iter - iterate over memory cgroup hierarchy
769 * @root: hierarchy root
770 * @prev: previously returned memcg, NULL on first invocation
771 * @reclaim: cookie for shared reclaim walks, NULL for full walks
773 * Returns references to children of the hierarchy below @root, or
774 * @root itself, or %NULL after a full round-trip.
776 * Caller must pass the return value in @prev on subsequent
777 * invocations for reference counting, or use mem_cgroup_iter_break()
778 * to cancel a hierarchy walk before the round-trip is complete.
780 * Reclaimers can specify a zone and a priority level in @reclaim to
781 * divide up the memcgs in the hierarchy among all concurrent
782 * reclaimers operating on the same zone and priority.
784 struct mem_cgroup *mem_cgroup_iter(struct mem_cgroup *root,
785 struct mem_cgroup *prev,
786 struct mem_cgroup_reclaim_cookie *reclaim)
788 struct mem_cgroup_reclaim_iter *uninitialized_var(iter);
789 struct cgroup_subsys_state *css = NULL;
790 struct mem_cgroup *memcg = NULL;
791 struct mem_cgroup *pos = NULL;
793 if (mem_cgroup_disabled())
797 root = root_mem_cgroup;
799 if (prev && !reclaim)
802 if (!root->use_hierarchy && root != root_mem_cgroup) {
811 struct mem_cgroup_per_zone *mz;
813 mz = mem_cgroup_zone_zoneinfo(root, reclaim->zone);
814 iter = &mz->iter[reclaim->priority];
816 if (prev && reclaim->generation != iter->generation)
820 pos = READ_ONCE(iter->position);
821 if (!pos || css_tryget(&pos->css))
824 * css reference reached zero, so iter->position will
825 * be cleared by ->css_released. However, we should not
826 * rely on this happening soon, because ->css_released
827 * is called from a work queue, and by busy-waiting we
828 * might block it. So we clear iter->position right
831 (void)cmpxchg(&iter->position, pos, NULL);
839 css = css_next_descendant_pre(css, &root->css);
842 * Reclaimers share the hierarchy walk, and a
843 * new one might jump in right at the end of
844 * the hierarchy - make sure they see at least
845 * one group and restart from the beginning.
853 * Verify the css and acquire a reference. The root
854 * is provided by the caller, so we know it's alive
855 * and kicking, and don't take an extra reference.
857 memcg = mem_cgroup_from_css(css);
859 if (css == &root->css)
870 * The position could have already been updated by a competing
871 * thread, so check that the value hasn't changed since we read
872 * it to avoid reclaiming from the same cgroup twice.
874 (void)cmpxchg(&iter->position, pos, memcg);
882 reclaim->generation = iter->generation;
888 if (prev && prev != root)
895 * mem_cgroup_iter_break - abort a hierarchy walk prematurely
896 * @root: hierarchy root
897 * @prev: last visited hierarchy member as returned by mem_cgroup_iter()
899 void mem_cgroup_iter_break(struct mem_cgroup *root,
900 struct mem_cgroup *prev)
903 root = root_mem_cgroup;
904 if (prev && prev != root)
908 static void invalidate_reclaim_iterators(struct mem_cgroup *dead_memcg)
910 struct mem_cgroup *memcg = dead_memcg;
911 struct mem_cgroup_reclaim_iter *iter;
912 struct mem_cgroup_per_zone *mz;
916 while ((memcg = parent_mem_cgroup(memcg))) {
918 for (zid = 0; zid < MAX_NR_ZONES; zid++) {
919 mz = &memcg->nodeinfo[nid]->zoneinfo[zid];
920 for (i = 0; i <= DEF_PRIORITY; i++) {
922 cmpxchg(&iter->position,
931 * Iteration constructs for visiting all cgroups (under a tree). If
932 * loops are exited prematurely (break), mem_cgroup_iter_break() must
933 * be used for reference counting.
935 #define for_each_mem_cgroup_tree(iter, root) \
936 for (iter = mem_cgroup_iter(root, NULL, NULL); \
938 iter = mem_cgroup_iter(root, iter, NULL))
940 #define for_each_mem_cgroup(iter) \
941 for (iter = mem_cgroup_iter(NULL, NULL, NULL); \
943 iter = mem_cgroup_iter(NULL, iter, NULL))
946 * mem_cgroup_zone_lruvec - get the lru list vector for a zone and memcg
947 * @zone: zone of the wanted lruvec
948 * @memcg: memcg of the wanted lruvec
950 * Returns the lru list vector holding pages for the given @zone and
951 * @mem. This can be the global zone lruvec, if the memory controller
954 struct lruvec *mem_cgroup_zone_lruvec(struct zone *zone,
955 struct mem_cgroup *memcg)
957 struct mem_cgroup_per_zone *mz;
958 struct lruvec *lruvec;
960 if (mem_cgroup_disabled()) {
961 lruvec = &zone->lruvec;
965 mz = mem_cgroup_zone_zoneinfo(memcg, zone);
966 lruvec = &mz->lruvec;
969 * Since a node can be onlined after the mem_cgroup was created,
970 * we have to be prepared to initialize lruvec->zone here;
971 * and if offlined then reonlined, we need to reinitialize it.
973 if (unlikely(lruvec->zone != zone))
979 * mem_cgroup_page_lruvec - return lruvec for isolating/putting an LRU page
981 * @zone: zone of the page
983 * This function is only safe when following the LRU page isolation
984 * and putback protocol: the LRU lock must be held, and the page must
985 * either be PageLRU() or the caller must have isolated/allocated it.
987 struct lruvec *mem_cgroup_page_lruvec(struct page *page, struct zone *zone)
989 struct mem_cgroup_per_zone *mz;
990 struct mem_cgroup *memcg;
991 struct lruvec *lruvec;
993 if (mem_cgroup_disabled()) {
994 lruvec = &zone->lruvec;
998 memcg = page->mem_cgroup;
1000 * Swapcache readahead pages are added to the LRU - and
1001 * possibly migrated - before they are charged.
1004 memcg = root_mem_cgroup;
1006 mz = mem_cgroup_page_zoneinfo(memcg, page);
1007 lruvec = &mz->lruvec;
1010 * Since a node can be onlined after the mem_cgroup was created,
1011 * we have to be prepared to initialize lruvec->zone here;
1012 * and if offlined then reonlined, we need to reinitialize it.
1014 if (unlikely(lruvec->zone != zone))
1015 lruvec->zone = zone;
1020 * mem_cgroup_update_lru_size - account for adding or removing an lru page
1021 * @lruvec: mem_cgroup per zone lru vector
1022 * @lru: index of lru list the page is sitting on
1023 * @nr_pages: positive when adding or negative when removing
1025 * This function must be called when a page is added to or removed from an
1028 void mem_cgroup_update_lru_size(struct lruvec *lruvec, enum lru_list lru,
1031 struct mem_cgroup_per_zone *mz;
1032 unsigned long *lru_size;
1034 if (mem_cgroup_disabled())
1037 mz = container_of(lruvec, struct mem_cgroup_per_zone, lruvec);
1038 lru_size = mz->lru_size + lru;
1039 *lru_size += nr_pages;
1040 VM_BUG_ON((long)(*lru_size) < 0);
1043 bool task_in_mem_cgroup(struct task_struct *task, struct mem_cgroup *memcg)
1045 struct mem_cgroup *task_memcg;
1046 struct task_struct *p;
1049 p = find_lock_task_mm(task);
1051 task_memcg = get_mem_cgroup_from_mm(p->mm);
1055 * All threads may have already detached their mm's, but the oom
1056 * killer still needs to detect if they have already been oom
1057 * killed to prevent needlessly killing additional tasks.
1060 task_memcg = mem_cgroup_from_task(task);
1061 css_get(&task_memcg->css);
1064 ret = mem_cgroup_is_descendant(task_memcg, memcg);
1065 css_put(&task_memcg->css);
1070 * mem_cgroup_margin - calculate chargeable space of a memory cgroup
1071 * @memcg: the memory cgroup
1073 * Returns the maximum amount of memory @mem can be charged with, in
1076 static unsigned long mem_cgroup_margin(struct mem_cgroup *memcg)
1078 unsigned long margin = 0;
1079 unsigned long count;
1080 unsigned long limit;
1082 count = page_counter_read(&memcg->memory);
1083 limit = READ_ONCE(memcg->memory.limit);
1085 margin = limit - count;
1087 if (do_memsw_account()) {
1088 count = page_counter_read(&memcg->memsw);
1089 limit = READ_ONCE(memcg->memsw.limit);
1091 margin = min(margin, limit - count);
1098 * A routine for checking "mem" is under move_account() or not.
1100 * Checking a cgroup is mc.from or mc.to or under hierarchy of
1101 * moving cgroups. This is for waiting at high-memory pressure
1104 static bool mem_cgroup_under_move(struct mem_cgroup *memcg)
1106 struct mem_cgroup *from;
1107 struct mem_cgroup *to;
1110 * Unlike task_move routines, we access mc.to, mc.from not under
1111 * mutual exclusion by cgroup_mutex. Here, we take spinlock instead.
1113 spin_lock(&mc.lock);
1119 ret = mem_cgroup_is_descendant(from, memcg) ||
1120 mem_cgroup_is_descendant(to, memcg);
1122 spin_unlock(&mc.lock);
1126 static bool mem_cgroup_wait_acct_move(struct mem_cgroup *memcg)
1128 if (mc.moving_task && current != mc.moving_task) {
1129 if (mem_cgroup_under_move(memcg)) {
1131 prepare_to_wait(&mc.waitq, &wait, TASK_INTERRUPTIBLE);
1132 /* moving charge context might have finished. */
1135 finish_wait(&mc.waitq, &wait);
1142 #define K(x) ((x) << (PAGE_SHIFT-10))
1144 * mem_cgroup_print_oom_info: Print OOM information relevant to memory controller.
1145 * @memcg: The memory cgroup that went over limit
1146 * @p: Task that is going to be killed
1148 * NOTE: @memcg and @p's mem_cgroup can be different when hierarchy is
1151 void mem_cgroup_print_oom_info(struct mem_cgroup *memcg, struct task_struct *p)
1153 /* oom_info_lock ensures that parallel ooms do not interleave */
1154 static DEFINE_MUTEX(oom_info_lock);
1155 struct mem_cgroup *iter;
1158 mutex_lock(&oom_info_lock);
1162 pr_info("Task in ");
1163 pr_cont_cgroup_path(task_cgroup(p, memory_cgrp_id));
1164 pr_cont(" killed as a result of limit of ");
1166 pr_info("Memory limit reached of cgroup ");
1169 pr_cont_cgroup_path(memcg->css.cgroup);
1174 pr_info("memory: usage %llukB, limit %llukB, failcnt %lu\n",
1175 K((u64)page_counter_read(&memcg->memory)),
1176 K((u64)memcg->memory.limit), memcg->memory.failcnt);
1177 pr_info("memory+swap: usage %llukB, limit %llukB, failcnt %lu\n",
1178 K((u64)page_counter_read(&memcg->memsw)),
1179 K((u64)memcg->memsw.limit), memcg->memsw.failcnt);
1180 pr_info("kmem: usage %llukB, limit %llukB, failcnt %lu\n",
1181 K((u64)page_counter_read(&memcg->kmem)),
1182 K((u64)memcg->kmem.limit), memcg->kmem.failcnt);
1184 for_each_mem_cgroup_tree(iter, memcg) {
1185 pr_info("Memory cgroup stats for ");
1186 pr_cont_cgroup_path(iter->css.cgroup);
1189 for (i = 0; i < MEM_CGROUP_STAT_NSTATS; i++) {
1190 if (i == MEM_CGROUP_STAT_SWAP && !do_swap_account)
1192 pr_cont(" %s:%luKB", mem_cgroup_stat_names[i],
1193 K(mem_cgroup_read_stat(iter, i)));
1196 for (i = 0; i < NR_LRU_LISTS; i++)
1197 pr_cont(" %s:%luKB", mem_cgroup_lru_names[i],
1198 K(mem_cgroup_nr_lru_pages(iter, BIT(i))));
1202 mutex_unlock(&oom_info_lock);
1206 * This function returns the number of memcg under hierarchy tree. Returns
1207 * 1(self count) if no children.
1209 static int mem_cgroup_count_children(struct mem_cgroup *memcg)
1212 struct mem_cgroup *iter;
1214 for_each_mem_cgroup_tree(iter, memcg)
1220 * Return the memory (and swap, if configured) limit for a memcg.
1222 static unsigned long mem_cgroup_get_limit(struct mem_cgroup *memcg)
1224 unsigned long limit;
1226 limit = memcg->memory.limit;
1227 if (mem_cgroup_swappiness(memcg)) {
1228 unsigned long memsw_limit;
1229 unsigned long swap_limit;
1231 memsw_limit = memcg->memsw.limit;
1232 swap_limit = memcg->swap.limit;
1233 swap_limit = min(swap_limit, (unsigned long)total_swap_pages);
1234 limit = min(limit + swap_limit, memsw_limit);
1239 static void mem_cgroup_out_of_memory(struct mem_cgroup *memcg, gfp_t gfp_mask,
1242 struct oom_control oc = {
1245 .gfp_mask = gfp_mask,
1248 struct mem_cgroup *iter;
1249 unsigned long chosen_points = 0;
1250 unsigned long totalpages;
1251 unsigned int points = 0;
1252 struct task_struct *chosen = NULL;
1254 mutex_lock(&oom_lock);
1257 * If current has a pending SIGKILL or is exiting, then automatically
1258 * select it. The goal is to allow it to allocate so that it may
1259 * quickly exit and free its memory.
1261 if (fatal_signal_pending(current) || task_will_free_mem(current)) {
1262 mark_oom_victim(current);
1266 check_panic_on_oom(&oc, CONSTRAINT_MEMCG, memcg);
1267 totalpages = mem_cgroup_get_limit(memcg) ? : 1;
1268 for_each_mem_cgroup_tree(iter, memcg) {
1269 struct css_task_iter it;
1270 struct task_struct *task;
1272 css_task_iter_start(&iter->css, &it);
1273 while ((task = css_task_iter_next(&it))) {
1274 switch (oom_scan_process_thread(&oc, task, totalpages)) {
1275 case OOM_SCAN_SELECT:
1277 put_task_struct(chosen);
1279 chosen_points = ULONG_MAX;
1280 get_task_struct(chosen);
1282 case OOM_SCAN_CONTINUE:
1284 case OOM_SCAN_ABORT:
1285 css_task_iter_end(&it);
1286 mem_cgroup_iter_break(memcg, iter);
1288 put_task_struct(chosen);
1293 points = oom_badness(task, memcg, NULL, totalpages);
1294 if (!points || points < chosen_points)
1296 /* Prefer thread group leaders for display purposes */
1297 if (points == chosen_points &&
1298 thread_group_leader(chosen))
1302 put_task_struct(chosen);
1304 chosen_points = points;
1305 get_task_struct(chosen);
1307 css_task_iter_end(&it);
1311 points = chosen_points * 1000 / totalpages;
1312 oom_kill_process(&oc, chosen, points, totalpages, memcg,
1313 "Memory cgroup out of memory");
1316 mutex_unlock(&oom_lock);
1319 #if MAX_NUMNODES > 1
1322 * test_mem_cgroup_node_reclaimable
1323 * @memcg: the target memcg
1324 * @nid: the node ID to be checked.
1325 * @noswap : specify true here if the user wants flle only information.
1327 * This function returns whether the specified memcg contains any
1328 * reclaimable pages on a node. Returns true if there are any reclaimable
1329 * pages in the node.
1331 static bool test_mem_cgroup_node_reclaimable(struct mem_cgroup *memcg,
1332 int nid, bool noswap)
1334 if (mem_cgroup_node_nr_lru_pages(memcg, nid, LRU_ALL_FILE))
1336 if (noswap || !total_swap_pages)
1338 if (mem_cgroup_node_nr_lru_pages(memcg, nid, LRU_ALL_ANON))
1345 * Always updating the nodemask is not very good - even if we have an empty
1346 * list or the wrong list here, we can start from some node and traverse all
1347 * nodes based on the zonelist. So update the list loosely once per 10 secs.
1350 static void mem_cgroup_may_update_nodemask(struct mem_cgroup *memcg)
1354 * numainfo_events > 0 means there was at least NUMAINFO_EVENTS_TARGET
1355 * pagein/pageout changes since the last update.
1357 if (!atomic_read(&memcg->numainfo_events))
1359 if (atomic_inc_return(&memcg->numainfo_updating) > 1)
1362 /* make a nodemask where this memcg uses memory from */
1363 memcg->scan_nodes = node_states[N_MEMORY];
1365 for_each_node_mask(nid, node_states[N_MEMORY]) {
1367 if (!test_mem_cgroup_node_reclaimable(memcg, nid, false))
1368 node_clear(nid, memcg->scan_nodes);
1371 atomic_set(&memcg->numainfo_events, 0);
1372 atomic_set(&memcg->numainfo_updating, 0);
1376 * Selecting a node where we start reclaim from. Because what we need is just
1377 * reducing usage counter, start from anywhere is O,K. Considering
1378 * memory reclaim from current node, there are pros. and cons.
1380 * Freeing memory from current node means freeing memory from a node which
1381 * we'll use or we've used. So, it may make LRU bad. And if several threads
1382 * hit limits, it will see a contention on a node. But freeing from remote
1383 * node means more costs for memory reclaim because of memory latency.
1385 * Now, we use round-robin. Better algorithm is welcomed.
1387 int mem_cgroup_select_victim_node(struct mem_cgroup *memcg)
1391 mem_cgroup_may_update_nodemask(memcg);
1392 node = memcg->last_scanned_node;
1394 node = next_node(node, memcg->scan_nodes);
1395 if (node == MAX_NUMNODES)
1396 node = first_node(memcg->scan_nodes);
1398 * We call this when we hit limit, not when pages are added to LRU.
1399 * No LRU may hold pages because all pages are UNEVICTABLE or
1400 * memcg is too small and all pages are not on LRU. In that case,
1401 * we use curret node.
1403 if (unlikely(node == MAX_NUMNODES))
1404 node = numa_node_id();
1406 memcg->last_scanned_node = node;
1410 int mem_cgroup_select_victim_node(struct mem_cgroup *memcg)
1416 static int mem_cgroup_soft_reclaim(struct mem_cgroup *root_memcg,
1419 unsigned long *total_scanned)
1421 struct mem_cgroup *victim = NULL;
1424 unsigned long excess;
1425 unsigned long nr_scanned;
1426 struct mem_cgroup_reclaim_cookie reclaim = {
1431 excess = soft_limit_excess(root_memcg);
1434 victim = mem_cgroup_iter(root_memcg, victim, &reclaim);
1439 * If we have not been able to reclaim
1440 * anything, it might because there are
1441 * no reclaimable pages under this hierarchy
1446 * We want to do more targeted reclaim.
1447 * excess >> 2 is not to excessive so as to
1448 * reclaim too much, nor too less that we keep
1449 * coming back to reclaim from this cgroup
1451 if (total >= (excess >> 2) ||
1452 (loop > MEM_CGROUP_MAX_RECLAIM_LOOPS))
1457 total += mem_cgroup_shrink_node_zone(victim, gfp_mask, false,
1459 *total_scanned += nr_scanned;
1460 if (!soft_limit_excess(root_memcg))
1463 mem_cgroup_iter_break(root_memcg, victim);
1467 #ifdef CONFIG_LOCKDEP
1468 static struct lockdep_map memcg_oom_lock_dep_map = {
1469 .name = "memcg_oom_lock",
1473 static DEFINE_SPINLOCK(memcg_oom_lock);
1476 * Check OOM-Killer is already running under our hierarchy.
1477 * If someone is running, return false.
1479 static bool mem_cgroup_oom_trylock(struct mem_cgroup *memcg)
1481 struct mem_cgroup *iter, *failed = NULL;
1483 spin_lock(&memcg_oom_lock);
1485 for_each_mem_cgroup_tree(iter, memcg) {
1486 if (iter->oom_lock) {
1488 * this subtree of our hierarchy is already locked
1489 * so we cannot give a lock.
1492 mem_cgroup_iter_break(memcg, iter);
1495 iter->oom_lock = true;
1500 * OK, we failed to lock the whole subtree so we have
1501 * to clean up what we set up to the failing subtree
1503 for_each_mem_cgroup_tree(iter, memcg) {
1504 if (iter == failed) {
1505 mem_cgroup_iter_break(memcg, iter);
1508 iter->oom_lock = false;
1511 mutex_acquire(&memcg_oom_lock_dep_map, 0, 1, _RET_IP_);
1513 spin_unlock(&memcg_oom_lock);
1518 static void mem_cgroup_oom_unlock(struct mem_cgroup *memcg)
1520 struct mem_cgroup *iter;
1522 spin_lock(&memcg_oom_lock);
1523 mutex_release(&memcg_oom_lock_dep_map, 1, _RET_IP_);
1524 for_each_mem_cgroup_tree(iter, memcg)
1525 iter->oom_lock = false;
1526 spin_unlock(&memcg_oom_lock);
1529 static void mem_cgroup_mark_under_oom(struct mem_cgroup *memcg)
1531 struct mem_cgroup *iter;
1533 spin_lock(&memcg_oom_lock);
1534 for_each_mem_cgroup_tree(iter, memcg)
1536 spin_unlock(&memcg_oom_lock);
1539 static void mem_cgroup_unmark_under_oom(struct mem_cgroup *memcg)
1541 struct mem_cgroup *iter;
1544 * When a new child is created while the hierarchy is under oom,
1545 * mem_cgroup_oom_lock() may not be called. Watch for underflow.
1547 spin_lock(&memcg_oom_lock);
1548 for_each_mem_cgroup_tree(iter, memcg)
1549 if (iter->under_oom > 0)
1551 spin_unlock(&memcg_oom_lock);
1554 static DECLARE_WAIT_QUEUE_HEAD(memcg_oom_waitq);
1556 struct oom_wait_info {
1557 struct mem_cgroup *memcg;
1561 static int memcg_oom_wake_function(wait_queue_t *wait,
1562 unsigned mode, int sync, void *arg)
1564 struct mem_cgroup *wake_memcg = (struct mem_cgroup *)arg;
1565 struct mem_cgroup *oom_wait_memcg;
1566 struct oom_wait_info *oom_wait_info;
1568 oom_wait_info = container_of(wait, struct oom_wait_info, wait);
1569 oom_wait_memcg = oom_wait_info->memcg;
1571 if (!mem_cgroup_is_descendant(wake_memcg, oom_wait_memcg) &&
1572 !mem_cgroup_is_descendant(oom_wait_memcg, wake_memcg))
1574 return autoremove_wake_function(wait, mode, sync, arg);
1577 static void memcg_oom_recover(struct mem_cgroup *memcg)
1580 * For the following lockless ->under_oom test, the only required
1581 * guarantee is that it must see the state asserted by an OOM when
1582 * this function is called as a result of userland actions
1583 * triggered by the notification of the OOM. This is trivially
1584 * achieved by invoking mem_cgroup_mark_under_oom() before
1585 * triggering notification.
1587 if (memcg && memcg->under_oom)
1588 __wake_up(&memcg_oom_waitq, TASK_NORMAL, 0, memcg);
1591 static void mem_cgroup_oom(struct mem_cgroup *memcg, gfp_t mask, int order)
1593 if (!current->memcg_may_oom)
1596 * We are in the middle of the charge context here, so we
1597 * don't want to block when potentially sitting on a callstack
1598 * that holds all kinds of filesystem and mm locks.
1600 * Also, the caller may handle a failed allocation gracefully
1601 * (like optional page cache readahead) and so an OOM killer
1602 * invocation might not even be necessary.
1604 * That's why we don't do anything here except remember the
1605 * OOM context and then deal with it at the end of the page
1606 * fault when the stack is unwound, the locks are released,
1607 * and when we know whether the fault was overall successful.
1609 css_get(&memcg->css);
1610 current->memcg_in_oom = memcg;
1611 current->memcg_oom_gfp_mask = mask;
1612 current->memcg_oom_order = order;
1616 * mem_cgroup_oom_synchronize - complete memcg OOM handling
1617 * @handle: actually kill/wait or just clean up the OOM state
1619 * This has to be called at the end of a page fault if the memcg OOM
1620 * handler was enabled.
1622 * Memcg supports userspace OOM handling where failed allocations must
1623 * sleep on a waitqueue until the userspace task resolves the
1624 * situation. Sleeping directly in the charge context with all kinds
1625 * of locks held is not a good idea, instead we remember an OOM state
1626 * in the task and mem_cgroup_oom_synchronize() has to be called at
1627 * the end of the page fault to complete the OOM handling.
1629 * Returns %true if an ongoing memcg OOM situation was detected and
1630 * completed, %false otherwise.
1632 bool mem_cgroup_oom_synchronize(bool handle)
1634 struct mem_cgroup *memcg = current->memcg_in_oom;
1635 struct oom_wait_info owait;
1638 /* OOM is global, do not handle */
1642 if (!handle || oom_killer_disabled)
1645 owait.memcg = memcg;
1646 owait.wait.flags = 0;
1647 owait.wait.func = memcg_oom_wake_function;
1648 owait.wait.private = current;
1649 INIT_LIST_HEAD(&owait.wait.task_list);
1651 prepare_to_wait(&memcg_oom_waitq, &owait.wait, TASK_KILLABLE);
1652 mem_cgroup_mark_under_oom(memcg);
1654 locked = mem_cgroup_oom_trylock(memcg);
1657 mem_cgroup_oom_notify(memcg);
1659 if (locked && !memcg->oom_kill_disable) {
1660 mem_cgroup_unmark_under_oom(memcg);
1661 finish_wait(&memcg_oom_waitq, &owait.wait);
1662 mem_cgroup_out_of_memory(memcg, current->memcg_oom_gfp_mask,
1663 current->memcg_oom_order);
1666 mem_cgroup_unmark_under_oom(memcg);
1667 finish_wait(&memcg_oom_waitq, &owait.wait);
1671 mem_cgroup_oom_unlock(memcg);
1673 * There is no guarantee that an OOM-lock contender
1674 * sees the wakeups triggered by the OOM kill
1675 * uncharges. Wake any sleepers explicitely.
1677 memcg_oom_recover(memcg);
1680 current->memcg_in_oom = NULL;
1681 css_put(&memcg->css);
1686 * lock_page_memcg - lock a page->mem_cgroup binding
1689 * This function protects unlocked LRU pages from being moved to
1690 * another cgroup and stabilizes their page->mem_cgroup binding.
1692 void lock_page_memcg(struct page *page)
1694 struct mem_cgroup *memcg;
1695 unsigned long flags;
1698 * The RCU lock is held throughout the transaction. The fast
1699 * path can get away without acquiring the memcg->move_lock
1700 * because page moving starts with an RCU grace period.
1704 if (mem_cgroup_disabled())
1707 memcg = page->mem_cgroup;
1708 if (unlikely(!memcg))
1711 if (atomic_read(&memcg->moving_account) <= 0)
1714 spin_lock_irqsave(&memcg->move_lock, flags);
1715 if (memcg != page->mem_cgroup) {
1716 spin_unlock_irqrestore(&memcg->move_lock, flags);
1721 * When charge migration first begins, we can have locked and
1722 * unlocked page stat updates happening concurrently. Track
1723 * the task who has the lock for unlock_page_memcg().
1725 memcg->move_lock_task = current;
1726 memcg->move_lock_flags = flags;
1730 EXPORT_SYMBOL(lock_page_memcg);
1733 * unlock_page_memcg - unlock a page->mem_cgroup binding
1736 void unlock_page_memcg(struct page *page)
1738 struct mem_cgroup *memcg = page->mem_cgroup;
1740 if (memcg && memcg->move_lock_task == current) {
1741 unsigned long flags = memcg->move_lock_flags;
1743 memcg->move_lock_task = NULL;
1744 memcg->move_lock_flags = 0;
1746 spin_unlock_irqrestore(&memcg->move_lock, flags);
1751 EXPORT_SYMBOL(unlock_page_memcg);
1754 * size of first charge trial. "32" comes from vmscan.c's magic value.
1755 * TODO: maybe necessary to use big numbers in big irons.
1757 #define CHARGE_BATCH 32U
1758 struct memcg_stock_pcp {
1759 struct mem_cgroup *cached; /* this never be root cgroup */
1760 unsigned int nr_pages;
1761 struct work_struct work;
1762 unsigned long flags;
1763 #define FLUSHING_CACHED_CHARGE 0
1765 static DEFINE_PER_CPU(struct memcg_stock_pcp, memcg_stock);
1766 static DEFINE_MUTEX(percpu_charge_mutex);
1769 * consume_stock: Try to consume stocked charge on this cpu.
1770 * @memcg: memcg to consume from.
1771 * @nr_pages: how many pages to charge.
1773 * The charges will only happen if @memcg matches the current cpu's memcg
1774 * stock, and at least @nr_pages are available in that stock. Failure to
1775 * service an allocation will refill the stock.
1777 * returns true if successful, false otherwise.
1779 static bool consume_stock(struct mem_cgroup *memcg, unsigned int nr_pages)
1781 struct memcg_stock_pcp *stock;
1784 if (nr_pages > CHARGE_BATCH)
1787 stock = &get_cpu_var(memcg_stock);
1788 if (memcg == stock->cached && stock->nr_pages >= nr_pages) {
1789 stock->nr_pages -= nr_pages;
1792 put_cpu_var(memcg_stock);
1797 * Returns stocks cached in percpu and reset cached information.
1799 static void drain_stock(struct memcg_stock_pcp *stock)
1801 struct mem_cgroup *old = stock->cached;
1803 if (stock->nr_pages) {
1804 page_counter_uncharge(&old->memory, stock->nr_pages);
1805 if (do_memsw_account())
1806 page_counter_uncharge(&old->memsw, stock->nr_pages);
1807 css_put_many(&old->css, stock->nr_pages);
1808 stock->nr_pages = 0;
1810 stock->cached = NULL;
1814 * This must be called under preempt disabled or must be called by
1815 * a thread which is pinned to local cpu.
1817 static void drain_local_stock(struct work_struct *dummy)
1819 struct memcg_stock_pcp *stock = this_cpu_ptr(&memcg_stock);
1821 clear_bit(FLUSHING_CACHED_CHARGE, &stock->flags);
1825 * Cache charges(val) to local per_cpu area.
1826 * This will be consumed by consume_stock() function, later.
1828 static void refill_stock(struct mem_cgroup *memcg, unsigned int nr_pages)
1830 struct memcg_stock_pcp *stock = &get_cpu_var(memcg_stock);
1832 if (stock->cached != memcg) { /* reset if necessary */
1834 stock->cached = memcg;
1836 stock->nr_pages += nr_pages;
1837 put_cpu_var(memcg_stock);
1841 * Drains all per-CPU charge caches for given root_memcg resp. subtree
1842 * of the hierarchy under it.
1844 static void drain_all_stock(struct mem_cgroup *root_memcg)
1848 /* If someone's already draining, avoid adding running more workers. */
1849 if (!mutex_trylock(&percpu_charge_mutex))
1851 /* Notify other cpus that system-wide "drain" is running */
1854 for_each_online_cpu(cpu) {
1855 struct memcg_stock_pcp *stock = &per_cpu(memcg_stock, cpu);
1856 struct mem_cgroup *memcg;
1858 memcg = stock->cached;
1859 if (!memcg || !stock->nr_pages)
1861 if (!mem_cgroup_is_descendant(memcg, root_memcg))
1863 if (!test_and_set_bit(FLUSHING_CACHED_CHARGE, &stock->flags)) {
1865 drain_local_stock(&stock->work);
1867 schedule_work_on(cpu, &stock->work);
1872 mutex_unlock(&percpu_charge_mutex);
1875 static int memcg_cpu_hotplug_callback(struct notifier_block *nb,
1876 unsigned long action,
1879 int cpu = (unsigned long)hcpu;
1880 struct memcg_stock_pcp *stock;
1882 if (action == CPU_ONLINE)
1885 if (action != CPU_DEAD && action != CPU_DEAD_FROZEN)
1888 stock = &per_cpu(memcg_stock, cpu);
1893 static void reclaim_high(struct mem_cgroup *memcg,
1894 unsigned int nr_pages,
1898 if (page_counter_read(&memcg->memory) <= memcg->high)
1900 mem_cgroup_events(memcg, MEMCG_HIGH, 1);
1901 try_to_free_mem_cgroup_pages(memcg, nr_pages, gfp_mask, true);
1902 } while ((memcg = parent_mem_cgroup(memcg)));
1905 static void high_work_func(struct work_struct *work)
1907 struct mem_cgroup *memcg;
1909 memcg = container_of(work, struct mem_cgroup, high_work);
1910 reclaim_high(memcg, CHARGE_BATCH, GFP_KERNEL);
1914 * Scheduled by try_charge() to be executed from the userland return path
1915 * and reclaims memory over the high limit.
1917 void mem_cgroup_handle_over_high(void)
1919 unsigned int nr_pages = current->memcg_nr_pages_over_high;
1920 struct mem_cgroup *memcg;
1922 if (likely(!nr_pages))
1925 memcg = get_mem_cgroup_from_mm(current->mm);
1926 reclaim_high(memcg, nr_pages, GFP_KERNEL);
1927 css_put(&memcg->css);
1928 current->memcg_nr_pages_over_high = 0;
1931 static int try_charge(struct mem_cgroup *memcg, gfp_t gfp_mask,
1932 unsigned int nr_pages)
1934 unsigned int batch = max(CHARGE_BATCH, nr_pages);
1935 int nr_retries = MEM_CGROUP_RECLAIM_RETRIES;
1936 struct mem_cgroup *mem_over_limit;
1937 struct page_counter *counter;
1938 unsigned long nr_reclaimed;
1939 bool may_swap = true;
1940 bool drained = false;
1942 if (mem_cgroup_is_root(memcg))
1945 if (consume_stock(memcg, nr_pages))
1948 if (!do_memsw_account() ||
1949 page_counter_try_charge(&memcg->memsw, batch, &counter)) {
1950 if (page_counter_try_charge(&memcg->memory, batch, &counter))
1952 if (do_memsw_account())
1953 page_counter_uncharge(&memcg->memsw, batch);
1954 mem_over_limit = mem_cgroup_from_counter(counter, memory);
1956 mem_over_limit = mem_cgroup_from_counter(counter, memsw);
1960 if (batch > nr_pages) {
1966 * Unlike in global OOM situations, memcg is not in a physical
1967 * memory shortage. Allow dying and OOM-killed tasks to
1968 * bypass the last charges so that they can exit quickly and
1969 * free their memory.
1971 if (unlikely(test_thread_flag(TIF_MEMDIE) ||
1972 fatal_signal_pending(current) ||
1973 current->flags & PF_EXITING))
1976 if (unlikely(task_in_memcg_oom(current)))
1979 if (!gfpflags_allow_blocking(gfp_mask))
1982 mem_cgroup_events(mem_over_limit, MEMCG_MAX, 1);
1984 nr_reclaimed = try_to_free_mem_cgroup_pages(mem_over_limit, nr_pages,
1985 gfp_mask, may_swap);
1987 if (mem_cgroup_margin(mem_over_limit) >= nr_pages)
1991 drain_all_stock(mem_over_limit);
1996 if (gfp_mask & __GFP_NORETRY)
1999 * Even though the limit is exceeded at this point, reclaim
2000 * may have been able to free some pages. Retry the charge
2001 * before killing the task.
2003 * Only for regular pages, though: huge pages are rather
2004 * unlikely to succeed so close to the limit, and we fall back
2005 * to regular pages anyway in case of failure.
2007 if (nr_reclaimed && nr_pages <= (1 << PAGE_ALLOC_COSTLY_ORDER))
2010 * At task move, charge accounts can be doubly counted. So, it's
2011 * better to wait until the end of task_move if something is going on.
2013 if (mem_cgroup_wait_acct_move(mem_over_limit))
2019 if (gfp_mask & __GFP_NOFAIL)
2022 if (fatal_signal_pending(current))
2025 mem_cgroup_events(mem_over_limit, MEMCG_OOM, 1);
2027 mem_cgroup_oom(mem_over_limit, gfp_mask,
2028 get_order(nr_pages * PAGE_SIZE));
2030 if (!(gfp_mask & __GFP_NOFAIL))
2034 * The allocation either can't fail or will lead to more memory
2035 * being freed very soon. Allow memory usage go over the limit
2036 * temporarily by force charging it.
2038 page_counter_charge(&memcg->memory, nr_pages);
2039 if (do_memsw_account())
2040 page_counter_charge(&memcg->memsw, nr_pages);
2041 css_get_many(&memcg->css, nr_pages);
2046 css_get_many(&memcg->css, batch);
2047 if (batch > nr_pages)
2048 refill_stock(memcg, batch - nr_pages);
2051 * If the hierarchy is above the normal consumption range, schedule
2052 * reclaim on returning to userland. We can perform reclaim here
2053 * if __GFP_RECLAIM but let's always punt for simplicity and so that
2054 * GFP_KERNEL can consistently be used during reclaim. @memcg is
2055 * not recorded as it most likely matches current's and won't
2056 * change in the meantime. As high limit is checked again before
2057 * reclaim, the cost of mismatch is negligible.
2060 if (page_counter_read(&memcg->memory) > memcg->high) {
2061 /* Don't bother a random interrupted task */
2062 if (in_interrupt()) {
2063 schedule_work(&memcg->high_work);
2066 current->memcg_nr_pages_over_high += batch;
2067 set_notify_resume(current);
2070 } while ((memcg = parent_mem_cgroup(memcg)));
2075 static void cancel_charge(struct mem_cgroup *memcg, unsigned int nr_pages)
2077 if (mem_cgroup_is_root(memcg))
2080 page_counter_uncharge(&memcg->memory, nr_pages);
2081 if (do_memsw_account())
2082 page_counter_uncharge(&memcg->memsw, nr_pages);
2084 css_put_many(&memcg->css, nr_pages);
2087 static void lock_page_lru(struct page *page, int *isolated)
2089 struct zone *zone = page_zone(page);
2091 spin_lock_irq(&zone->lru_lock);
2092 if (PageLRU(page)) {
2093 struct lruvec *lruvec;
2095 lruvec = mem_cgroup_page_lruvec(page, zone);
2097 del_page_from_lru_list(page, lruvec, page_lru(page));
2103 static void unlock_page_lru(struct page *page, int isolated)
2105 struct zone *zone = page_zone(page);
2108 struct lruvec *lruvec;
2110 lruvec = mem_cgroup_page_lruvec(page, zone);
2111 VM_BUG_ON_PAGE(PageLRU(page), page);
2113 add_page_to_lru_list(page, lruvec, page_lru(page));
2115 spin_unlock_irq(&zone->lru_lock);
2118 static void commit_charge(struct page *page, struct mem_cgroup *memcg,
2123 VM_BUG_ON_PAGE(page->mem_cgroup, page);
2126 * In some cases, SwapCache and FUSE(splice_buf->radixtree), the page
2127 * may already be on some other mem_cgroup's LRU. Take care of it.
2130 lock_page_lru(page, &isolated);
2133 * Nobody should be changing or seriously looking at
2134 * page->mem_cgroup at this point:
2136 * - the page is uncharged
2138 * - the page is off-LRU
2140 * - an anonymous fault has exclusive page access, except for
2141 * a locked page table
2143 * - a page cache insertion, a swapin fault, or a migration
2144 * have the page locked
2146 page->mem_cgroup = memcg;
2149 unlock_page_lru(page, isolated);
2153 static int memcg_alloc_cache_id(void)
2158 id = ida_simple_get(&memcg_cache_ida,
2159 0, MEMCG_CACHES_MAX_SIZE, GFP_KERNEL);
2163 if (id < memcg_nr_cache_ids)
2167 * There's no space for the new id in memcg_caches arrays,
2168 * so we have to grow them.
2170 down_write(&memcg_cache_ids_sem);
2172 size = 2 * (id + 1);
2173 if (size < MEMCG_CACHES_MIN_SIZE)
2174 size = MEMCG_CACHES_MIN_SIZE;
2175 else if (size > MEMCG_CACHES_MAX_SIZE)
2176 size = MEMCG_CACHES_MAX_SIZE;
2178 err = memcg_update_all_caches(size);
2180 err = memcg_update_all_list_lrus(size);
2182 memcg_nr_cache_ids = size;
2184 up_write(&memcg_cache_ids_sem);
2187 ida_simple_remove(&memcg_cache_ida, id);
2193 static void memcg_free_cache_id(int id)
2195 ida_simple_remove(&memcg_cache_ida, id);
2198 struct memcg_kmem_cache_create_work {
2199 struct mem_cgroup *memcg;
2200 struct kmem_cache *cachep;
2201 struct work_struct work;
2204 static void memcg_kmem_cache_create_func(struct work_struct *w)
2206 struct memcg_kmem_cache_create_work *cw =
2207 container_of(w, struct memcg_kmem_cache_create_work, work);
2208 struct mem_cgroup *memcg = cw->memcg;
2209 struct kmem_cache *cachep = cw->cachep;
2211 memcg_create_kmem_cache(memcg, cachep);
2213 css_put(&memcg->css);
2218 * Enqueue the creation of a per-memcg kmem_cache.
2220 static void __memcg_schedule_kmem_cache_create(struct mem_cgroup *memcg,
2221 struct kmem_cache *cachep)
2223 struct memcg_kmem_cache_create_work *cw;
2225 cw = kmalloc(sizeof(*cw), GFP_NOWAIT);
2229 css_get(&memcg->css);
2232 cw->cachep = cachep;
2233 INIT_WORK(&cw->work, memcg_kmem_cache_create_func);
2235 schedule_work(&cw->work);
2238 static void memcg_schedule_kmem_cache_create(struct mem_cgroup *memcg,
2239 struct kmem_cache *cachep)
2242 * We need to stop accounting when we kmalloc, because if the
2243 * corresponding kmalloc cache is not yet created, the first allocation
2244 * in __memcg_schedule_kmem_cache_create will recurse.
2246 * However, it is better to enclose the whole function. Depending on
2247 * the debugging options enabled, INIT_WORK(), for instance, can
2248 * trigger an allocation. This too, will make us recurse. Because at
2249 * this point we can't allow ourselves back into memcg_kmem_get_cache,
2250 * the safest choice is to do it like this, wrapping the whole function.
2252 current->memcg_kmem_skip_account = 1;
2253 __memcg_schedule_kmem_cache_create(memcg, cachep);
2254 current->memcg_kmem_skip_account = 0;
2258 * Return the kmem_cache we're supposed to use for a slab allocation.
2259 * We try to use the current memcg's version of the cache.
2261 * If the cache does not exist yet, if we are the first user of it,
2262 * we either create it immediately, if possible, or create it asynchronously
2264 * In the latter case, we will let the current allocation go through with
2265 * the original cache.
2267 * Can't be called in interrupt context or from kernel threads.
2268 * This function needs to be called with rcu_read_lock() held.
2270 struct kmem_cache *__memcg_kmem_get_cache(struct kmem_cache *cachep, gfp_t gfp)
2272 struct mem_cgroup *memcg;
2273 struct kmem_cache *memcg_cachep;
2276 VM_BUG_ON(!is_root_cache(cachep));
2278 if (cachep->flags & SLAB_ACCOUNT)
2279 gfp |= __GFP_ACCOUNT;
2281 if (!(gfp & __GFP_ACCOUNT))
2284 if (current->memcg_kmem_skip_account)
2287 memcg = get_mem_cgroup_from_mm(current->mm);
2288 kmemcg_id = READ_ONCE(memcg->kmemcg_id);
2292 memcg_cachep = cache_from_memcg_idx(cachep, kmemcg_id);
2293 if (likely(memcg_cachep))
2294 return memcg_cachep;
2297 * If we are in a safe context (can wait, and not in interrupt
2298 * context), we could be be predictable and return right away.
2299 * This would guarantee that the allocation being performed
2300 * already belongs in the new cache.
2302 * However, there are some clashes that can arrive from locking.
2303 * For instance, because we acquire the slab_mutex while doing
2304 * memcg_create_kmem_cache, this means no further allocation
2305 * could happen with the slab_mutex held. So it's better to
2308 memcg_schedule_kmem_cache_create(memcg, cachep);
2310 css_put(&memcg->css);
2314 void __memcg_kmem_put_cache(struct kmem_cache *cachep)
2316 if (!is_root_cache(cachep))
2317 css_put(&cachep->memcg_params.memcg->css);
2320 int __memcg_kmem_charge_memcg(struct page *page, gfp_t gfp, int order,
2321 struct mem_cgroup *memcg)
2323 unsigned int nr_pages = 1 << order;
2324 struct page_counter *counter;
2327 ret = try_charge(memcg, gfp, nr_pages);
2331 if (!cgroup_subsys_on_dfl(memory_cgrp_subsys) &&
2332 !page_counter_try_charge(&memcg->kmem, nr_pages, &counter)) {
2333 cancel_charge(memcg, nr_pages);
2337 page->mem_cgroup = memcg;
2342 int __memcg_kmem_charge(struct page *page, gfp_t gfp, int order)
2344 struct mem_cgroup *memcg;
2347 memcg = get_mem_cgroup_from_mm(current->mm);
2348 if (!mem_cgroup_is_root(memcg))
2349 ret = __memcg_kmem_charge_memcg(page, gfp, order, memcg);
2350 css_put(&memcg->css);
2354 void __memcg_kmem_uncharge(struct page *page, int order)
2356 struct mem_cgroup *memcg = page->mem_cgroup;
2357 unsigned int nr_pages = 1 << order;
2362 VM_BUG_ON_PAGE(mem_cgroup_is_root(memcg), page);
2364 if (!cgroup_subsys_on_dfl(memory_cgrp_subsys))
2365 page_counter_uncharge(&memcg->kmem, nr_pages);
2367 page_counter_uncharge(&memcg->memory, nr_pages);
2368 if (do_memsw_account())
2369 page_counter_uncharge(&memcg->memsw, nr_pages);
2371 page->mem_cgroup = NULL;
2372 css_put_many(&memcg->css, nr_pages);
2374 #endif /* !CONFIG_SLOB */
2376 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
2379 * Because tail pages are not marked as "used", set it. We're under
2380 * zone->lru_lock and migration entries setup in all page mappings.
2382 void mem_cgroup_split_huge_fixup(struct page *head)
2386 if (mem_cgroup_disabled())
2389 for (i = 1; i < HPAGE_PMD_NR; i++)
2390 head[i].mem_cgroup = head->mem_cgroup;
2392 __this_cpu_sub(head->mem_cgroup->stat->count[MEM_CGROUP_STAT_RSS_HUGE],
2395 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
2397 #ifdef CONFIG_MEMCG_SWAP
2398 static void mem_cgroup_swap_statistics(struct mem_cgroup *memcg,
2401 int val = (charge) ? 1 : -1;
2402 this_cpu_add(memcg->stat->count[MEM_CGROUP_STAT_SWAP], val);
2406 * mem_cgroup_move_swap_account - move swap charge and swap_cgroup's record.
2407 * @entry: swap entry to be moved
2408 * @from: mem_cgroup which the entry is moved from
2409 * @to: mem_cgroup which the entry is moved to
2411 * It succeeds only when the swap_cgroup's record for this entry is the same
2412 * as the mem_cgroup's id of @from.
2414 * Returns 0 on success, -EINVAL on failure.
2416 * The caller must have charged to @to, IOW, called page_counter_charge() about
2417 * both res and memsw, and called css_get().
2419 static int mem_cgroup_move_swap_account(swp_entry_t entry,
2420 struct mem_cgroup *from, struct mem_cgroup *to)
2422 unsigned short old_id, new_id;
2424 old_id = mem_cgroup_id(from);
2425 new_id = mem_cgroup_id(to);
2427 if (swap_cgroup_cmpxchg(entry, old_id, new_id) == old_id) {
2428 mem_cgroup_swap_statistics(from, false);
2429 mem_cgroup_swap_statistics(to, true);
2435 static inline int mem_cgroup_move_swap_account(swp_entry_t entry,
2436 struct mem_cgroup *from, struct mem_cgroup *to)
2442 static DEFINE_MUTEX(memcg_limit_mutex);
2444 static int mem_cgroup_resize_limit(struct mem_cgroup *memcg,
2445 unsigned long limit)
2447 unsigned long curusage;
2448 unsigned long oldusage;
2449 bool enlarge = false;
2454 * For keeping hierarchical_reclaim simple, how long we should retry
2455 * is depends on callers. We set our retry-count to be function
2456 * of # of children which we should visit in this loop.
2458 retry_count = MEM_CGROUP_RECLAIM_RETRIES *
2459 mem_cgroup_count_children(memcg);
2461 oldusage = page_counter_read(&memcg->memory);
2464 if (signal_pending(current)) {
2469 mutex_lock(&memcg_limit_mutex);
2470 if (limit > memcg->memsw.limit) {
2471 mutex_unlock(&memcg_limit_mutex);
2475 if (limit > memcg->memory.limit)
2477 ret = page_counter_limit(&memcg->memory, limit);
2478 mutex_unlock(&memcg_limit_mutex);
2483 try_to_free_mem_cgroup_pages(memcg, 1, GFP_KERNEL, true);
2485 curusage = page_counter_read(&memcg->memory);
2486 /* Usage is reduced ? */
2487 if (curusage >= oldusage)
2490 oldusage = curusage;
2491 } while (retry_count);
2493 if (!ret && enlarge)
2494 memcg_oom_recover(memcg);
2499 static int mem_cgroup_resize_memsw_limit(struct mem_cgroup *memcg,
2500 unsigned long limit)
2502 unsigned long curusage;
2503 unsigned long oldusage;
2504 bool enlarge = false;
2508 /* see mem_cgroup_resize_res_limit */
2509 retry_count = MEM_CGROUP_RECLAIM_RETRIES *
2510 mem_cgroup_count_children(memcg);
2512 oldusage = page_counter_read(&memcg->memsw);
2515 if (signal_pending(current)) {
2520 mutex_lock(&memcg_limit_mutex);
2521 if (limit < memcg->memory.limit) {
2522 mutex_unlock(&memcg_limit_mutex);
2526 if (limit > memcg->memsw.limit)
2528 ret = page_counter_limit(&memcg->memsw, limit);
2529 mutex_unlock(&memcg_limit_mutex);
2534 try_to_free_mem_cgroup_pages(memcg, 1, GFP_KERNEL, false);
2536 curusage = page_counter_read(&memcg->memsw);
2537 /* Usage is reduced ? */
2538 if (curusage >= oldusage)
2541 oldusage = curusage;
2542 } while (retry_count);
2544 if (!ret && enlarge)
2545 memcg_oom_recover(memcg);
2550 unsigned long mem_cgroup_soft_limit_reclaim(struct zone *zone, int order,
2552 unsigned long *total_scanned)
2554 unsigned long nr_reclaimed = 0;
2555 struct mem_cgroup_per_zone *mz, *next_mz = NULL;
2556 unsigned long reclaimed;
2558 struct mem_cgroup_tree_per_zone *mctz;
2559 unsigned long excess;
2560 unsigned long nr_scanned;
2565 mctz = soft_limit_tree_node_zone(zone_to_nid(zone), zone_idx(zone));
2567 * This loop can run a while, specially if mem_cgroup's continuously
2568 * keep exceeding their soft limit and putting the system under
2575 mz = mem_cgroup_largest_soft_limit_node(mctz);
2580 reclaimed = mem_cgroup_soft_reclaim(mz->memcg, zone,
2581 gfp_mask, &nr_scanned);
2582 nr_reclaimed += reclaimed;
2583 *total_scanned += nr_scanned;
2584 spin_lock_irq(&mctz->lock);
2585 __mem_cgroup_remove_exceeded(mz, mctz);
2588 * If we failed to reclaim anything from this memory cgroup
2589 * it is time to move on to the next cgroup
2593 next_mz = __mem_cgroup_largest_soft_limit_node(mctz);
2595 excess = soft_limit_excess(mz->memcg);
2597 * One school of thought says that we should not add
2598 * back the node to the tree if reclaim returns 0.
2599 * But our reclaim could return 0, simply because due
2600 * to priority we are exposing a smaller subset of
2601 * memory to reclaim from. Consider this as a longer
2604 /* If excess == 0, no tree ops */
2605 __mem_cgroup_insert_exceeded(mz, mctz, excess);
2606 spin_unlock_irq(&mctz->lock);
2607 css_put(&mz->memcg->css);
2610 * Could not reclaim anything and there are no more
2611 * mem cgroups to try or we seem to be looping without
2612 * reclaiming anything.
2614 if (!nr_reclaimed &&
2616 loop > MEM_CGROUP_MAX_SOFT_LIMIT_RECLAIM_LOOPS))
2618 } while (!nr_reclaimed);
2620 css_put(&next_mz->memcg->css);
2621 return nr_reclaimed;
2625 * Test whether @memcg has children, dead or alive. Note that this
2626 * function doesn't care whether @memcg has use_hierarchy enabled and
2627 * returns %true if there are child csses according to the cgroup
2628 * hierarchy. Testing use_hierarchy is the caller's responsiblity.
2630 static inline bool memcg_has_children(struct mem_cgroup *memcg)
2635 ret = css_next_child(NULL, &memcg->css);
2641 * Reclaims as many pages from the given memcg as possible and moves
2642 * the rest to the parent.
2644 * Caller is responsible for holding css reference for memcg.
2646 static int mem_cgroup_force_empty(struct mem_cgroup *memcg)
2648 int nr_retries = MEM_CGROUP_RECLAIM_RETRIES;
2650 /* we call try-to-free pages for make this cgroup empty */
2651 lru_add_drain_all();
2652 /* try to free all pages in this cgroup */
2653 while (nr_retries && page_counter_read(&memcg->memory)) {
2656 if (signal_pending(current))
2659 progress = try_to_free_mem_cgroup_pages(memcg, 1,
2663 /* maybe some writeback is necessary */
2664 congestion_wait(BLK_RW_ASYNC, HZ/10);
2672 static ssize_t mem_cgroup_force_empty_write(struct kernfs_open_file *of,
2673 char *buf, size_t nbytes,
2676 struct mem_cgroup *memcg = mem_cgroup_from_css(of_css(of));
2678 if (mem_cgroup_is_root(memcg))
2680 return mem_cgroup_force_empty(memcg) ?: nbytes;
2683 static u64 mem_cgroup_hierarchy_read(struct cgroup_subsys_state *css,
2686 return mem_cgroup_from_css(css)->use_hierarchy;
2689 static int mem_cgroup_hierarchy_write(struct cgroup_subsys_state *css,
2690 struct cftype *cft, u64 val)
2693 struct mem_cgroup *memcg = mem_cgroup_from_css(css);
2694 struct mem_cgroup *parent_memcg = mem_cgroup_from_css(memcg->css.parent);
2696 if (memcg->use_hierarchy == val)
2700 * If parent's use_hierarchy is set, we can't make any modifications
2701 * in the child subtrees. If it is unset, then the change can
2702 * occur, provided the current cgroup has no children.
2704 * For the root cgroup, parent_mem is NULL, we allow value to be
2705 * set if there are no children.
2707 if ((!parent_memcg || !parent_memcg->use_hierarchy) &&
2708 (val == 1 || val == 0)) {
2709 if (!memcg_has_children(memcg))
2710 memcg->use_hierarchy = val;
2719 static void tree_stat(struct mem_cgroup *memcg, unsigned long *stat)
2721 struct mem_cgroup *iter;
2724 memset(stat, 0, sizeof(*stat) * MEMCG_NR_STAT);
2726 for_each_mem_cgroup_tree(iter, memcg) {
2727 for (i = 0; i < MEMCG_NR_STAT; i++)
2728 stat[i] += mem_cgroup_read_stat(iter, i);
2732 static void tree_events(struct mem_cgroup *memcg, unsigned long *events)
2734 struct mem_cgroup *iter;
2737 memset(events, 0, sizeof(*events) * MEMCG_NR_EVENTS);
2739 for_each_mem_cgroup_tree(iter, memcg) {
2740 for (i = 0; i < MEMCG_NR_EVENTS; i++)
2741 events[i] += mem_cgroup_read_events(iter, i);
2745 static unsigned long mem_cgroup_usage(struct mem_cgroup *memcg, bool swap)
2747 unsigned long val = 0;
2749 if (mem_cgroup_is_root(memcg)) {
2750 struct mem_cgroup *iter;
2752 for_each_mem_cgroup_tree(iter, memcg) {
2753 val += mem_cgroup_read_stat(iter,
2754 MEM_CGROUP_STAT_CACHE);
2755 val += mem_cgroup_read_stat(iter,
2756 MEM_CGROUP_STAT_RSS);
2758 val += mem_cgroup_read_stat(iter,
2759 MEM_CGROUP_STAT_SWAP);
2763 val = page_counter_read(&memcg->memory);
2765 val = page_counter_read(&memcg->memsw);
2778 static u64 mem_cgroup_read_u64(struct cgroup_subsys_state *css,
2781 struct mem_cgroup *memcg = mem_cgroup_from_css(css);
2782 struct page_counter *counter;
2784 switch (MEMFILE_TYPE(cft->private)) {
2786 counter = &memcg->memory;
2789 counter = &memcg->memsw;
2792 counter = &memcg->kmem;
2795 counter = &memcg->tcpmem;
2801 switch (MEMFILE_ATTR(cft->private)) {
2803 if (counter == &memcg->memory)
2804 return (u64)mem_cgroup_usage(memcg, false) * PAGE_SIZE;
2805 if (counter == &memcg->memsw)
2806 return (u64)mem_cgroup_usage(memcg, true) * PAGE_SIZE;
2807 return (u64)page_counter_read(counter) * PAGE_SIZE;
2809 return (u64)counter->limit * PAGE_SIZE;
2811 return (u64)counter->watermark * PAGE_SIZE;
2813 return counter->failcnt;
2814 case RES_SOFT_LIMIT:
2815 return (u64)memcg->soft_limit * PAGE_SIZE;
2822 static int memcg_online_kmem(struct mem_cgroup *memcg)
2826 if (cgroup_memory_nokmem)
2829 BUG_ON(memcg->kmemcg_id >= 0);
2830 BUG_ON(memcg->kmem_state);
2832 memcg_id = memcg_alloc_cache_id();
2836 static_branch_inc(&memcg_kmem_enabled_key);
2838 * A memory cgroup is considered kmem-online as soon as it gets
2839 * kmemcg_id. Setting the id after enabling static branching will
2840 * guarantee no one starts accounting before all call sites are
2843 memcg->kmemcg_id = memcg_id;
2844 memcg->kmem_state = KMEM_ONLINE;
2849 static void memcg_offline_kmem(struct mem_cgroup *memcg)
2851 struct cgroup_subsys_state *css;
2852 struct mem_cgroup *parent, *child;
2855 if (memcg->kmem_state != KMEM_ONLINE)
2858 * Clear the online state before clearing memcg_caches array
2859 * entries. The slab_mutex in memcg_deactivate_kmem_caches()
2860 * guarantees that no cache will be created for this cgroup
2861 * after we are done (see memcg_create_kmem_cache()).
2863 memcg->kmem_state = KMEM_ALLOCATED;
2865 memcg_deactivate_kmem_caches(memcg);
2867 kmemcg_id = memcg->kmemcg_id;
2868 BUG_ON(kmemcg_id < 0);
2870 parent = parent_mem_cgroup(memcg);
2872 parent = root_mem_cgroup;
2875 * Change kmemcg_id of this cgroup and all its descendants to the
2876 * parent's id, and then move all entries from this cgroup's list_lrus
2877 * to ones of the parent. After we have finished, all list_lrus
2878 * corresponding to this cgroup are guaranteed to remain empty. The
2879 * ordering is imposed by list_lru_node->lock taken by
2880 * memcg_drain_all_list_lrus().
2882 css_for_each_descendant_pre(css, &memcg->css) {
2883 child = mem_cgroup_from_css(css);
2884 BUG_ON(child->kmemcg_id != kmemcg_id);
2885 child->kmemcg_id = parent->kmemcg_id;
2886 if (!memcg->use_hierarchy)
2889 memcg_drain_all_list_lrus(kmemcg_id, parent->kmemcg_id);
2891 memcg_free_cache_id(kmemcg_id);
2894 static void memcg_free_kmem(struct mem_cgroup *memcg)
2896 /* css_alloc() failed, offlining didn't happen */
2897 if (unlikely(memcg->kmem_state == KMEM_ONLINE))
2898 memcg_offline_kmem(memcg);
2900 if (memcg->kmem_state == KMEM_ALLOCATED) {
2901 memcg_destroy_kmem_caches(memcg);
2902 static_branch_dec(&memcg_kmem_enabled_key);
2903 WARN_ON(page_counter_read(&memcg->kmem));
2907 static int memcg_online_kmem(struct mem_cgroup *memcg)
2911 static void memcg_offline_kmem(struct mem_cgroup *memcg)
2914 static void memcg_free_kmem(struct mem_cgroup *memcg)
2917 #endif /* !CONFIG_SLOB */
2919 static int memcg_update_kmem_limit(struct mem_cgroup *memcg,
2920 unsigned long limit)
2924 mutex_lock(&memcg_limit_mutex);
2925 ret = page_counter_limit(&memcg->kmem, limit);
2926 mutex_unlock(&memcg_limit_mutex);
2930 static int memcg_update_tcp_limit(struct mem_cgroup *memcg, unsigned long limit)
2934 mutex_lock(&memcg_limit_mutex);
2936 ret = page_counter_limit(&memcg->tcpmem, limit);
2940 if (!memcg->tcpmem_active) {
2942 * The active flag needs to be written after the static_key
2943 * update. This is what guarantees that the socket activation
2944 * function is the last one to run. See sock_update_memcg() for
2945 * details, and note that we don't mark any socket as belonging
2946 * to this memcg until that flag is up.
2948 * We need to do this, because static_keys will span multiple
2949 * sites, but we can't control their order. If we mark a socket
2950 * as accounted, but the accounting functions are not patched in
2951 * yet, we'll lose accounting.
2953 * We never race with the readers in sock_update_memcg(),
2954 * because when this value change, the code to process it is not
2957 static_branch_inc(&memcg_sockets_enabled_key);
2958 memcg->tcpmem_active = true;
2961 mutex_unlock(&memcg_limit_mutex);
2966 * The user of this function is...
2969 static ssize_t mem_cgroup_write(struct kernfs_open_file *of,
2970 char *buf, size_t nbytes, loff_t off)
2972 struct mem_cgroup *memcg = mem_cgroup_from_css(of_css(of));
2973 unsigned long nr_pages;
2976 buf = strstrip(buf);
2977 ret = page_counter_memparse(buf, "-1", &nr_pages);
2981 switch (MEMFILE_ATTR(of_cft(of)->private)) {
2983 if (mem_cgroup_is_root(memcg)) { /* Can't set limit on root */
2987 switch (MEMFILE_TYPE(of_cft(of)->private)) {
2989 ret = mem_cgroup_resize_limit(memcg, nr_pages);
2992 ret = mem_cgroup_resize_memsw_limit(memcg, nr_pages);
2995 ret = memcg_update_kmem_limit(memcg, nr_pages);
2998 ret = memcg_update_tcp_limit(memcg, nr_pages);
3002 case RES_SOFT_LIMIT:
3003 memcg->soft_limit = nr_pages;
3007 return ret ?: nbytes;
3010 static ssize_t mem_cgroup_reset(struct kernfs_open_file *of, char *buf,
3011 size_t nbytes, loff_t off)
3013 struct mem_cgroup *memcg = mem_cgroup_from_css(of_css(of));
3014 struct page_counter *counter;
3016 switch (MEMFILE_TYPE(of_cft(of)->private)) {
3018 counter = &memcg->memory;
3021 counter = &memcg->memsw;
3024 counter = &memcg->kmem;
3027 counter = &memcg->tcpmem;
3033 switch (MEMFILE_ATTR(of_cft(of)->private)) {
3035 page_counter_reset_watermark(counter);
3038 counter->failcnt = 0;
3047 static u64 mem_cgroup_move_charge_read(struct cgroup_subsys_state *css,
3050 return mem_cgroup_from_css(css)->move_charge_at_immigrate;
3054 static int mem_cgroup_move_charge_write(struct cgroup_subsys_state *css,
3055 struct cftype *cft, u64 val)
3057 struct mem_cgroup *memcg = mem_cgroup_from_css(css);
3059 if (val & ~MOVE_MASK)
3063 * No kind of locking is needed in here, because ->can_attach() will
3064 * check this value once in the beginning of the process, and then carry
3065 * on with stale data. This means that changes to this value will only
3066 * affect task migrations starting after the change.
3068 memcg->move_charge_at_immigrate = val;
3072 static int mem_cgroup_move_charge_write(struct cgroup_subsys_state *css,
3073 struct cftype *cft, u64 val)
3080 static int memcg_numa_stat_show(struct seq_file *m, void *v)
3084 unsigned int lru_mask;
3087 static const struct numa_stat stats[] = {
3088 { "total", LRU_ALL },
3089 { "file", LRU_ALL_FILE },
3090 { "anon", LRU_ALL_ANON },
3091 { "unevictable", BIT(LRU_UNEVICTABLE) },
3093 const struct numa_stat *stat;
3096 struct mem_cgroup *memcg = mem_cgroup_from_css(seq_css(m));
3098 for (stat = stats; stat < stats + ARRAY_SIZE(stats); stat++) {
3099 nr = mem_cgroup_nr_lru_pages(memcg, stat->lru_mask);
3100 seq_printf(m, "%s=%lu", stat->name, nr);
3101 for_each_node_state(nid, N_MEMORY) {
3102 nr = mem_cgroup_node_nr_lru_pages(memcg, nid,
3104 seq_printf(m, " N%d=%lu", nid, nr);
3109 for (stat = stats; stat < stats + ARRAY_SIZE(stats); stat++) {
3110 struct mem_cgroup *iter;
3113 for_each_mem_cgroup_tree(iter, memcg)
3114 nr += mem_cgroup_nr_lru_pages(iter, stat->lru_mask);
3115 seq_printf(m, "hierarchical_%s=%lu", stat->name, nr);
3116 for_each_node_state(nid, N_MEMORY) {
3118 for_each_mem_cgroup_tree(iter, memcg)
3119 nr += mem_cgroup_node_nr_lru_pages(
3120 iter, nid, stat->lru_mask);
3121 seq_printf(m, " N%d=%lu", nid, nr);
3128 #endif /* CONFIG_NUMA */
3130 static int memcg_stat_show(struct seq_file *m, void *v)
3132 struct mem_cgroup *memcg = mem_cgroup_from_css(seq_css(m));
3133 unsigned long memory, memsw;
3134 struct mem_cgroup *mi;
3137 BUILD_BUG_ON(ARRAY_SIZE(mem_cgroup_stat_names) !=
3138 MEM_CGROUP_STAT_NSTATS);
3139 BUILD_BUG_ON(ARRAY_SIZE(mem_cgroup_events_names) !=
3140 MEM_CGROUP_EVENTS_NSTATS);
3141 BUILD_BUG_ON(ARRAY_SIZE(mem_cgroup_lru_names) != NR_LRU_LISTS);
3143 for (i = 0; i < MEM_CGROUP_STAT_NSTATS; i++) {
3144 if (i == MEM_CGROUP_STAT_SWAP && !do_memsw_account())
3146 seq_printf(m, "%s %lu\n", mem_cgroup_stat_names[i],
3147 mem_cgroup_read_stat(memcg, i) * PAGE_SIZE);
3150 for (i = 0; i < MEM_CGROUP_EVENTS_NSTATS; i++)
3151 seq_printf(m, "%s %lu\n", mem_cgroup_events_names[i],
3152 mem_cgroup_read_events(memcg, i));
3154 for (i = 0; i < NR_LRU_LISTS; i++)
3155 seq_printf(m, "%s %lu\n", mem_cgroup_lru_names[i],
3156 mem_cgroup_nr_lru_pages(memcg, BIT(i)) * PAGE_SIZE);
3158 /* Hierarchical information */
3159 memory = memsw = PAGE_COUNTER_MAX;
3160 for (mi = memcg; mi; mi = parent_mem_cgroup(mi)) {
3161 memory = min(memory, mi->memory.limit);
3162 memsw = min(memsw, mi->memsw.limit);
3164 seq_printf(m, "hierarchical_memory_limit %llu\n",
3165 (u64)memory * PAGE_SIZE);
3166 if (do_memsw_account())
3167 seq_printf(m, "hierarchical_memsw_limit %llu\n",
3168 (u64)memsw * PAGE_SIZE);
3170 for (i = 0; i < MEM_CGROUP_STAT_NSTATS; i++) {
3171 unsigned long long val = 0;
3173 if (i == MEM_CGROUP_STAT_SWAP && !do_memsw_account())
3175 for_each_mem_cgroup_tree(mi, memcg)
3176 val += mem_cgroup_read_stat(mi, i) * PAGE_SIZE;
3177 seq_printf(m, "total_%s %llu\n", mem_cgroup_stat_names[i], val);
3180 for (i = 0; i < MEM_CGROUP_EVENTS_NSTATS; i++) {
3181 unsigned long long val = 0;
3183 for_each_mem_cgroup_tree(mi, memcg)
3184 val += mem_cgroup_read_events(mi, i);
3185 seq_printf(m, "total_%s %llu\n",
3186 mem_cgroup_events_names[i], val);
3189 for (i = 0; i < NR_LRU_LISTS; i++) {
3190 unsigned long long val = 0;
3192 for_each_mem_cgroup_tree(mi, memcg)
3193 val += mem_cgroup_nr_lru_pages(mi, BIT(i)) * PAGE_SIZE;
3194 seq_printf(m, "total_%s %llu\n", mem_cgroup_lru_names[i], val);
3197 #ifdef CONFIG_DEBUG_VM
3200 struct mem_cgroup_per_zone *mz;
3201 struct zone_reclaim_stat *rstat;
3202 unsigned long recent_rotated[2] = {0, 0};
3203 unsigned long recent_scanned[2] = {0, 0};
3205 for_each_online_node(nid)
3206 for (zid = 0; zid < MAX_NR_ZONES; zid++) {
3207 mz = &memcg->nodeinfo[nid]->zoneinfo[zid];
3208 rstat = &mz->lruvec.reclaim_stat;
3210 recent_rotated[0] += rstat->recent_rotated[0];
3211 recent_rotated[1] += rstat->recent_rotated[1];
3212 recent_scanned[0] += rstat->recent_scanned[0];
3213 recent_scanned[1] += rstat->recent_scanned[1];
3215 seq_printf(m, "recent_rotated_anon %lu\n", recent_rotated[0]);
3216 seq_printf(m, "recent_rotated_file %lu\n", recent_rotated[1]);
3217 seq_printf(m, "recent_scanned_anon %lu\n", recent_scanned[0]);
3218 seq_printf(m, "recent_scanned_file %lu\n", recent_scanned[1]);
3225 static u64 mem_cgroup_swappiness_read(struct cgroup_subsys_state *css,
3228 struct mem_cgroup *memcg = mem_cgroup_from_css(css);
3230 return mem_cgroup_swappiness(memcg);
3233 static int mem_cgroup_swappiness_write(struct cgroup_subsys_state *css,
3234 struct cftype *cft, u64 val)
3236 struct mem_cgroup *memcg = mem_cgroup_from_css(css);
3242 memcg->swappiness = val;
3244 vm_swappiness = val;
3249 static void __mem_cgroup_threshold(struct mem_cgroup *memcg, bool swap)
3251 struct mem_cgroup_threshold_ary *t;
3252 unsigned long usage;
3257 t = rcu_dereference(memcg->thresholds.primary);
3259 t = rcu_dereference(memcg->memsw_thresholds.primary);
3264 usage = mem_cgroup_usage(memcg, swap);
3267 * current_threshold points to threshold just below or equal to usage.
3268 * If it's not true, a threshold was crossed after last
3269 * call of __mem_cgroup_threshold().
3271 i = t->current_threshold;
3274 * Iterate backward over array of thresholds starting from
3275 * current_threshold and check if a threshold is crossed.
3276 * If none of thresholds below usage is crossed, we read
3277 * only one element of the array here.
3279 for (; i >= 0 && unlikely(t->entries[i].threshold > usage); i--)
3280 eventfd_signal(t->entries[i].eventfd, 1);
3282 /* i = current_threshold + 1 */
3286 * Iterate forward over array of thresholds starting from
3287 * current_threshold+1 and check if a threshold is crossed.
3288 * If none of thresholds above usage is crossed, we read
3289 * only one element of the array here.
3291 for (; i < t->size && unlikely(t->entries[i].threshold <= usage); i++)
3292 eventfd_signal(t->entries[i].eventfd, 1);
3294 /* Update current_threshold */
3295 t->current_threshold = i - 1;
3300 static void mem_cgroup_threshold(struct mem_cgroup *memcg)
3303 __mem_cgroup_threshold(memcg, false);
3304 if (do_memsw_account())
3305 __mem_cgroup_threshold(memcg, true);
3307 memcg = parent_mem_cgroup(memcg);
3311 static int compare_thresholds(const void *a, const void *b)
3313 const struct mem_cgroup_threshold *_a = a;
3314 const struct mem_cgroup_threshold *_b = b;
3316 if (_a->threshold > _b->threshold)
3319 if (_a->threshold < _b->threshold)
3325 static int mem_cgroup_oom_notify_cb(struct mem_cgroup *memcg)
3327 struct mem_cgroup_eventfd_list *ev;
3329 spin_lock(&memcg_oom_lock);
3331 list_for_each_entry(ev, &memcg->oom_notify, list)
3332 eventfd_signal(ev->eventfd, 1);
3334 spin_unlock(&memcg_oom_lock);
3338 static void mem_cgroup_oom_notify(struct mem_cgroup *memcg)
3340 struct mem_cgroup *iter;
3342 for_each_mem_cgroup_tree(iter, memcg)
3343 mem_cgroup_oom_notify_cb(iter);
3346 static int __mem_cgroup_usage_register_event(struct mem_cgroup *memcg,
3347 struct eventfd_ctx *eventfd, const char *args, enum res_type type)
3349 struct mem_cgroup_thresholds *thresholds;
3350 struct mem_cgroup_threshold_ary *new;
3351 unsigned long threshold;
3352 unsigned long usage;
3355 ret = page_counter_memparse(args, "-1", &threshold);
3359 mutex_lock(&memcg->thresholds_lock);
3362 thresholds = &memcg->thresholds;
3363 usage = mem_cgroup_usage(memcg, false);
3364 } else if (type == _MEMSWAP) {
3365 thresholds = &memcg->memsw_thresholds;
3366 usage = mem_cgroup_usage(memcg, true);
3370 /* Check if a threshold crossed before adding a new one */
3371 if (thresholds->primary)
3372 __mem_cgroup_threshold(memcg, type == _MEMSWAP);
3374 size = thresholds->primary ? thresholds->primary->size + 1 : 1;
3376 /* Allocate memory for new array of thresholds */
3377 new = kmalloc(sizeof(*new) + size * sizeof(struct mem_cgroup_threshold),
3385 /* Copy thresholds (if any) to new array */
3386 if (thresholds->primary) {
3387 memcpy(new->entries, thresholds->primary->entries, (size - 1) *
3388 sizeof(struct mem_cgroup_threshold));
3391 /* Add new threshold */
3392 new->entries[size - 1].eventfd = eventfd;
3393 new->entries[size - 1].threshold = threshold;
3395 /* Sort thresholds. Registering of new threshold isn't time-critical */
3396 sort(new->entries, size, sizeof(struct mem_cgroup_threshold),
3397 compare_thresholds, NULL);
3399 /* Find current threshold */
3400 new->current_threshold = -1;
3401 for (i = 0; i < size; i++) {
3402 if (new->entries[i].threshold <= usage) {
3404 * new->current_threshold will not be used until
3405 * rcu_assign_pointer(), so it's safe to increment
3408 ++new->current_threshold;
3413 /* Free old spare buffer and save old primary buffer as spare */
3414 kfree(thresholds->spare);
3415 thresholds->spare = thresholds->primary;
3417 rcu_assign_pointer(thresholds->primary, new);
3419 /* To be sure that nobody uses thresholds */
3423 mutex_unlock(&memcg->thresholds_lock);
3428 static int mem_cgroup_usage_register_event(struct mem_cgroup *memcg,
3429 struct eventfd_ctx *eventfd, const char *args)
3431 return __mem_cgroup_usage_register_event(memcg, eventfd, args, _MEM);
3434 static int memsw_cgroup_usage_register_event(struct mem_cgroup *memcg,
3435 struct eventfd_ctx *eventfd, const char *args)
3437 return __mem_cgroup_usage_register_event(memcg, eventfd, args, _MEMSWAP);
3440 static void __mem_cgroup_usage_unregister_event(struct mem_cgroup *memcg,
3441 struct eventfd_ctx *eventfd, enum res_type type)
3443 struct mem_cgroup_thresholds *thresholds;
3444 struct mem_cgroup_threshold_ary *new;
3445 unsigned long usage;
3448 mutex_lock(&memcg->thresholds_lock);
3451 thresholds = &memcg->thresholds;
3452 usage = mem_cgroup_usage(memcg, false);
3453 } else if (type == _MEMSWAP) {
3454 thresholds = &memcg->memsw_thresholds;
3455 usage = mem_cgroup_usage(memcg, true);
3459 if (!thresholds->primary)
3462 /* Check if a threshold crossed before removing */
3463 __mem_cgroup_threshold(memcg, type == _MEMSWAP);
3465 /* Calculate new number of threshold */
3467 for (i = 0; i < thresholds->primary->size; i++) {
3468 if (thresholds->primary->entries[i].eventfd != eventfd)
3472 new = thresholds->spare;
3474 /* Set thresholds array to NULL if we don't have thresholds */
3483 /* Copy thresholds and find current threshold */
3484 new->current_threshold = -1;
3485 for (i = 0, j = 0; i < thresholds->primary->size; i++) {
3486 if (thresholds->primary->entries[i].eventfd == eventfd)
3489 new->entries[j] = thresholds->primary->entries[i];
3490 if (new->entries[j].threshold <= usage) {
3492 * new->current_threshold will not be used
3493 * until rcu_assign_pointer(), so it's safe to increment
3496 ++new->current_threshold;
3502 /* Swap primary and spare array */
3503 thresholds->spare = thresholds->primary;
3505 rcu_assign_pointer(thresholds->primary, new);
3507 /* To be sure that nobody uses thresholds */
3510 /* If all events are unregistered, free the spare array */
3512 kfree(thresholds->spare);
3513 thresholds->spare = NULL;
3516 mutex_unlock(&memcg->thresholds_lock);
3519 static void mem_cgroup_usage_unregister_event(struct mem_cgroup *memcg,
3520 struct eventfd_ctx *eventfd)
3522 return __mem_cgroup_usage_unregister_event(memcg, eventfd, _MEM);
3525 static void memsw_cgroup_usage_unregister_event(struct mem_cgroup *memcg,
3526 struct eventfd_ctx *eventfd)
3528 return __mem_cgroup_usage_unregister_event(memcg, eventfd, _MEMSWAP);
3531 static int mem_cgroup_oom_register_event(struct mem_cgroup *memcg,
3532 struct eventfd_ctx *eventfd, const char *args)
3534 struct mem_cgroup_eventfd_list *event;
3536 event = kmalloc(sizeof(*event), GFP_KERNEL);
3540 spin_lock(&memcg_oom_lock);
3542 event->eventfd = eventfd;
3543 list_add(&event->list, &memcg->oom_notify);
3545 /* already in OOM ? */
3546 if (memcg->under_oom)
3547 eventfd_signal(eventfd, 1);
3548 spin_unlock(&memcg_oom_lock);
3553 static void mem_cgroup_oom_unregister_event(struct mem_cgroup *memcg,
3554 struct eventfd_ctx *eventfd)
3556 struct mem_cgroup_eventfd_list *ev, *tmp;
3558 spin_lock(&memcg_oom_lock);
3560 list_for_each_entry_safe(ev, tmp, &memcg->oom_notify, list) {
3561 if (ev->eventfd == eventfd) {
3562 list_del(&ev->list);
3567 spin_unlock(&memcg_oom_lock);
3570 static int mem_cgroup_oom_control_read(struct seq_file *sf, void *v)
3572 struct mem_cgroup *memcg = mem_cgroup_from_css(seq_css(sf));
3574 seq_printf(sf, "oom_kill_disable %d\n", memcg->oom_kill_disable);
3575 seq_printf(sf, "under_oom %d\n", (bool)memcg->under_oom);
3579 static int mem_cgroup_oom_control_write(struct cgroup_subsys_state *css,
3580 struct cftype *cft, u64 val)
3582 struct mem_cgroup *memcg = mem_cgroup_from_css(css);
3584 /* cannot set to root cgroup and only 0 and 1 are allowed */
3585 if (!css->parent || !((val == 0) || (val == 1)))
3588 memcg->oom_kill_disable = val;
3590 memcg_oom_recover(memcg);
3595 #ifdef CONFIG_CGROUP_WRITEBACK
3597 struct list_head *mem_cgroup_cgwb_list(struct mem_cgroup *memcg)
3599 return &memcg->cgwb_list;
3602 static int memcg_wb_domain_init(struct mem_cgroup *memcg, gfp_t gfp)
3604 return wb_domain_init(&memcg->cgwb_domain, gfp);
3607 static void memcg_wb_domain_exit(struct mem_cgroup *memcg)
3609 wb_domain_exit(&memcg->cgwb_domain);
3612 static void memcg_wb_domain_size_changed(struct mem_cgroup *memcg)
3614 wb_domain_size_changed(&memcg->cgwb_domain);
3617 struct wb_domain *mem_cgroup_wb_domain(struct bdi_writeback *wb)
3619 struct mem_cgroup *memcg = mem_cgroup_from_css(wb->memcg_css);
3621 if (!memcg->css.parent)
3624 return &memcg->cgwb_domain;
3628 * mem_cgroup_wb_stats - retrieve writeback related stats from its memcg
3629 * @wb: bdi_writeback in question
3630 * @pfilepages: out parameter for number of file pages
3631 * @pheadroom: out parameter for number of allocatable pages according to memcg
3632 * @pdirty: out parameter for number of dirty pages
3633 * @pwriteback: out parameter for number of pages under writeback
3635 * Determine the numbers of file, headroom, dirty, and writeback pages in
3636 * @wb's memcg. File, dirty and writeback are self-explanatory. Headroom
3637 * is a bit more involved.
3639 * A memcg's headroom is "min(max, high) - used". In the hierarchy, the
3640 * headroom is calculated as the lowest headroom of itself and the
3641 * ancestors. Note that this doesn't consider the actual amount of
3642 * available memory in the system. The caller should further cap
3643 * *@pheadroom accordingly.
3645 void mem_cgroup_wb_stats(struct bdi_writeback *wb, unsigned long *pfilepages,
3646 unsigned long *pheadroom, unsigned long *pdirty,
3647 unsigned long *pwriteback)
3649 struct mem_cgroup *memcg = mem_cgroup_from_css(wb->memcg_css);
3650 struct mem_cgroup *parent;
3652 *pdirty = mem_cgroup_read_stat(memcg, MEM_CGROUP_STAT_DIRTY);
3654 /* this should eventually include NR_UNSTABLE_NFS */
3655 *pwriteback = mem_cgroup_read_stat(memcg, MEM_CGROUP_STAT_WRITEBACK);
3656 *pfilepages = mem_cgroup_nr_lru_pages(memcg, (1 << LRU_INACTIVE_FILE) |
3657 (1 << LRU_ACTIVE_FILE));
3658 *pheadroom = PAGE_COUNTER_MAX;
3660 while ((parent = parent_mem_cgroup(memcg))) {
3661 unsigned long ceiling = min(memcg->memory.limit, memcg->high);
3662 unsigned long used = page_counter_read(&memcg->memory);
3664 *pheadroom = min(*pheadroom, ceiling - min(ceiling, used));
3669 #else /* CONFIG_CGROUP_WRITEBACK */
3671 static int memcg_wb_domain_init(struct mem_cgroup *memcg, gfp_t gfp)
3676 static void memcg_wb_domain_exit(struct mem_cgroup *memcg)
3680 static void memcg_wb_domain_size_changed(struct mem_cgroup *memcg)
3684 #endif /* CONFIG_CGROUP_WRITEBACK */
3687 * DO NOT USE IN NEW FILES.
3689 * "cgroup.event_control" implementation.
3691 * This is way over-engineered. It tries to support fully configurable
3692 * events for each user. Such level of flexibility is completely
3693 * unnecessary especially in the light of the planned unified hierarchy.
3695 * Please deprecate this and replace with something simpler if at all
3700 * Unregister event and free resources.
3702 * Gets called from workqueue.
3704 static void memcg_event_remove(struct work_struct *work)
3706 struct mem_cgroup_event *event =
3707 container_of(work, struct mem_cgroup_event, remove);
3708 struct mem_cgroup *memcg = event->memcg;
3710 remove_wait_queue(event->wqh, &event->wait);
3712 event->unregister_event(memcg, event->eventfd);
3714 /* Notify userspace the event is going away. */
3715 eventfd_signal(event->eventfd, 1);
3717 eventfd_ctx_put(event->eventfd);
3719 css_put(&memcg->css);
3723 * Gets called on POLLHUP on eventfd when user closes it.
3725 * Called with wqh->lock held and interrupts disabled.
3727 static int memcg_event_wake(wait_queue_t *wait, unsigned mode,
3728 int sync, void *key)
3730 struct mem_cgroup_event *event =
3731 container_of(wait, struct mem_cgroup_event, wait);
3732 struct mem_cgroup *memcg = event->memcg;
3733 unsigned long flags = (unsigned long)key;
3735 if (flags & POLLHUP) {
3737 * If the event has been detached at cgroup removal, we
3738 * can simply return knowing the other side will cleanup
3741 * We can't race against event freeing since the other
3742 * side will require wqh->lock via remove_wait_queue(),
3745 spin_lock(&memcg->event_list_lock);
3746 if (!list_empty(&event->list)) {
3747 list_del_init(&event->list);
3749 * We are in atomic context, but cgroup_event_remove()
3750 * may sleep, so we have to call it in workqueue.
3752 schedule_work(&event->remove);
3754 spin_unlock(&memcg->event_list_lock);
3760 static void memcg_event_ptable_queue_proc(struct file *file,
3761 wait_queue_head_t *wqh, poll_table *pt)
3763 struct mem_cgroup_event *event =
3764 container_of(pt, struct mem_cgroup_event, pt);
3767 add_wait_queue(wqh, &event->wait);
3771 * DO NOT USE IN NEW FILES.
3773 * Parse input and register new cgroup event handler.
3775 * Input must be in format '<event_fd> <control_fd> <args>'.
3776 * Interpretation of args is defined by control file implementation.
3778 static ssize_t memcg_write_event_control(struct kernfs_open_file *of,
3779 char *buf, size_t nbytes, loff_t off)
3781 struct cgroup_subsys_state *css = of_css(of);
3782 struct mem_cgroup *memcg = mem_cgroup_from_css(css);
3783 struct mem_cgroup_event *event;
3784 struct cgroup_subsys_state *cfile_css;
3785 unsigned int efd, cfd;
3792 buf = strstrip(buf);
3794 efd = simple_strtoul(buf, &endp, 10);
3799 cfd = simple_strtoul(buf, &endp, 10);
3800 if ((*endp != ' ') && (*endp != '\0'))
3804 event = kzalloc(sizeof(*event), GFP_KERNEL);
3808 event->memcg = memcg;
3809 INIT_LIST_HEAD(&event->list);
3810 init_poll_funcptr(&event->pt, memcg_event_ptable_queue_proc);
3811 init_waitqueue_func_entry(&event->wait, memcg_event_wake);
3812 INIT_WORK(&event->remove, memcg_event_remove);
3820 event->eventfd = eventfd_ctx_fileget(efile.file);
3821 if (IS_ERR(event->eventfd)) {
3822 ret = PTR_ERR(event->eventfd);
3829 goto out_put_eventfd;
3832 /* the process need read permission on control file */
3833 /* AV: shouldn't we check that it's been opened for read instead? */
3834 ret = inode_permission(file_inode(cfile.file), MAY_READ);
3839 * Determine the event callbacks and set them in @event. This used
3840 * to be done via struct cftype but cgroup core no longer knows
3841 * about these events. The following is crude but the whole thing
3842 * is for compatibility anyway.
3844 * DO NOT ADD NEW FILES.
3846 name = cfile.file->f_path.dentry->d_name.name;
3848 if (!strcmp(name, "memory.usage_in_bytes")) {
3849 event->register_event = mem_cgroup_usage_register_event;
3850 event->unregister_event = mem_cgroup_usage_unregister_event;
3851 } else if (!strcmp(name, "memory.oom_control")) {
3852 event->register_event = mem_cgroup_oom_register_event;
3853 event->unregister_event = mem_cgroup_oom_unregister_event;
3854 } else if (!strcmp(name, "memory.pressure_level")) {
3855 event->register_event = vmpressure_register_event;
3856 event->unregister_event = vmpressure_unregister_event;
3857 } else if (!strcmp(name, "memory.memsw.usage_in_bytes")) {
3858 event->register_event = memsw_cgroup_usage_register_event;
3859 event->unregister_event = memsw_cgroup_usage_unregister_event;
3866 * Verify @cfile should belong to @css. Also, remaining events are
3867 * automatically removed on cgroup destruction but the removal is
3868 * asynchronous, so take an extra ref on @css.
3870 cfile_css = css_tryget_online_from_dir(cfile.file->f_path.dentry->d_parent,
3871 &memory_cgrp_subsys);
3873 if (IS_ERR(cfile_css))
3875 if (cfile_css != css) {
3880 ret = event->register_event(memcg, event->eventfd, buf);
3884 efile.file->f_op->poll(efile.file, &event->pt);
3886 spin_lock(&memcg->event_list_lock);
3887 list_add(&event->list, &memcg->event_list);
3888 spin_unlock(&memcg->event_list_lock);
3900 eventfd_ctx_put(event->eventfd);
3909 static struct cftype mem_cgroup_legacy_files[] = {
3911 .name = "usage_in_bytes",
3912 .private = MEMFILE_PRIVATE(_MEM, RES_USAGE),
3913 .read_u64 = mem_cgroup_read_u64,
3916 .name = "max_usage_in_bytes",
3917 .private = MEMFILE_PRIVATE(_MEM, RES_MAX_USAGE),
3918 .write = mem_cgroup_reset,
3919 .read_u64 = mem_cgroup_read_u64,
3922 .name = "limit_in_bytes",
3923 .private = MEMFILE_PRIVATE(_MEM, RES_LIMIT),
3924 .write = mem_cgroup_write,
3925 .read_u64 = mem_cgroup_read_u64,
3928 .name = "soft_limit_in_bytes",
3929 .private = MEMFILE_PRIVATE(_MEM, RES_SOFT_LIMIT),
3930 .write = mem_cgroup_write,
3931 .read_u64 = mem_cgroup_read_u64,
3935 .private = MEMFILE_PRIVATE(_MEM, RES_FAILCNT),
3936 .write = mem_cgroup_reset,
3937 .read_u64 = mem_cgroup_read_u64,
3941 .seq_show = memcg_stat_show,
3944 .name = "force_empty",
3945 .write = mem_cgroup_force_empty_write,
3948 .name = "use_hierarchy",
3949 .write_u64 = mem_cgroup_hierarchy_write,
3950 .read_u64 = mem_cgroup_hierarchy_read,
3953 .name = "cgroup.event_control", /* XXX: for compat */
3954 .write = memcg_write_event_control,
3955 .flags = CFTYPE_NO_PREFIX | CFTYPE_WORLD_WRITABLE,
3958 .name = "swappiness",
3959 .read_u64 = mem_cgroup_swappiness_read,
3960 .write_u64 = mem_cgroup_swappiness_write,
3963 .name = "move_charge_at_immigrate",
3964 .read_u64 = mem_cgroup_move_charge_read,
3965 .write_u64 = mem_cgroup_move_charge_write,
3968 .name = "oom_control",
3969 .seq_show = mem_cgroup_oom_control_read,
3970 .write_u64 = mem_cgroup_oom_control_write,
3971 .private = MEMFILE_PRIVATE(_OOM_TYPE, OOM_CONTROL),
3974 .name = "pressure_level",
3978 .name = "numa_stat",
3979 .seq_show = memcg_numa_stat_show,
3983 .name = "kmem.limit_in_bytes",
3984 .private = MEMFILE_PRIVATE(_KMEM, RES_LIMIT),
3985 .write = mem_cgroup_write,
3986 .read_u64 = mem_cgroup_read_u64,
3989 .name = "kmem.usage_in_bytes",
3990 .private = MEMFILE_PRIVATE(_KMEM, RES_USAGE),
3991 .read_u64 = mem_cgroup_read_u64,
3994 .name = "kmem.failcnt",
3995 .private = MEMFILE_PRIVATE(_KMEM, RES_FAILCNT),
3996 .write = mem_cgroup_reset,
3997 .read_u64 = mem_cgroup_read_u64,
4000 .name = "kmem.max_usage_in_bytes",
4001 .private = MEMFILE_PRIVATE(_KMEM, RES_MAX_USAGE),
4002 .write = mem_cgroup_reset,
4003 .read_u64 = mem_cgroup_read_u64,
4005 #ifdef CONFIG_SLABINFO
4007 .name = "kmem.slabinfo",
4008 .seq_start = slab_start,
4009 .seq_next = slab_next,
4010 .seq_stop = slab_stop,
4011 .seq_show = memcg_slab_show,
4015 .name = "kmem.tcp.limit_in_bytes",
4016 .private = MEMFILE_PRIVATE(_TCP, RES_LIMIT),
4017 .write = mem_cgroup_write,
4018 .read_u64 = mem_cgroup_read_u64,
4021 .name = "kmem.tcp.usage_in_bytes",
4022 .private = MEMFILE_PRIVATE(_TCP, RES_USAGE),
4023 .read_u64 = mem_cgroup_read_u64,
4026 .name = "kmem.tcp.failcnt",
4027 .private = MEMFILE_PRIVATE(_TCP, RES_FAILCNT),
4028 .write = mem_cgroup_reset,
4029 .read_u64 = mem_cgroup_read_u64,
4032 .name = "kmem.tcp.max_usage_in_bytes",
4033 .private = MEMFILE_PRIVATE(_TCP, RES_MAX_USAGE),
4034 .write = mem_cgroup_reset,
4035 .read_u64 = mem_cgroup_read_u64,
4037 { }, /* terminate */
4040 static int alloc_mem_cgroup_per_zone_info(struct mem_cgroup *memcg, int node)
4042 struct mem_cgroup_per_node *pn;
4043 struct mem_cgroup_per_zone *mz;
4044 int zone, tmp = node;
4046 * This routine is called against possible nodes.
4047 * But it's BUG to call kmalloc() against offline node.
4049 * TODO: this routine can waste much memory for nodes which will
4050 * never be onlined. It's better to use memory hotplug callback
4053 if (!node_state(node, N_NORMAL_MEMORY))
4055 pn = kzalloc_node(sizeof(*pn), GFP_KERNEL, tmp);
4059 for (zone = 0; zone < MAX_NR_ZONES; zone++) {
4060 mz = &pn->zoneinfo[zone];
4061 lruvec_init(&mz->lruvec);
4062 mz->usage_in_excess = 0;
4063 mz->on_tree = false;
4066 memcg->nodeinfo[node] = pn;
4070 static void free_mem_cgroup_per_zone_info(struct mem_cgroup *memcg, int node)
4072 kfree(memcg->nodeinfo[node]);
4075 static void mem_cgroup_free(struct mem_cgroup *memcg)
4079 memcg_wb_domain_exit(memcg);
4081 free_mem_cgroup_per_zone_info(memcg, node);
4082 free_percpu(memcg->stat);
4086 static struct mem_cgroup *mem_cgroup_alloc(void)
4088 struct mem_cgroup *memcg;
4092 size = sizeof(struct mem_cgroup);
4093 size += nr_node_ids * sizeof(struct mem_cgroup_per_node *);
4095 memcg = kzalloc(size, GFP_KERNEL);
4099 memcg->stat = alloc_percpu(struct mem_cgroup_stat_cpu);
4104 if (alloc_mem_cgroup_per_zone_info(memcg, node))
4107 if (memcg_wb_domain_init(memcg, GFP_KERNEL))
4110 INIT_WORK(&memcg->high_work, high_work_func);
4111 memcg->last_scanned_node = MAX_NUMNODES;
4112 INIT_LIST_HEAD(&memcg->oom_notify);
4113 mutex_init(&memcg->thresholds_lock);
4114 spin_lock_init(&memcg->move_lock);
4115 vmpressure_init(&memcg->vmpressure);
4116 INIT_LIST_HEAD(&memcg->event_list);
4117 spin_lock_init(&memcg->event_list_lock);
4118 memcg->socket_pressure = jiffies;
4120 memcg->kmemcg_id = -1;
4122 #ifdef CONFIG_CGROUP_WRITEBACK
4123 INIT_LIST_HEAD(&memcg->cgwb_list);
4127 mem_cgroup_free(memcg);
4131 static struct cgroup_subsys_state * __ref
4132 mem_cgroup_css_alloc(struct cgroup_subsys_state *parent_css)
4134 struct mem_cgroup *parent = mem_cgroup_from_css(parent_css);
4135 struct mem_cgroup *memcg;
4136 long error = -ENOMEM;
4138 memcg = mem_cgroup_alloc();
4140 return ERR_PTR(error);
4142 memcg->high = PAGE_COUNTER_MAX;
4143 memcg->soft_limit = PAGE_COUNTER_MAX;
4145 memcg->swappiness = mem_cgroup_swappiness(parent);
4146 memcg->oom_kill_disable = parent->oom_kill_disable;
4148 if (parent && parent->use_hierarchy) {
4149 memcg->use_hierarchy = true;
4150 page_counter_init(&memcg->memory, &parent->memory);
4151 page_counter_init(&memcg->swap, &parent->swap);
4152 page_counter_init(&memcg->memsw, &parent->memsw);
4153 page_counter_init(&memcg->kmem, &parent->kmem);
4154 page_counter_init(&memcg->tcpmem, &parent->tcpmem);
4156 page_counter_init(&memcg->memory, NULL);
4157 page_counter_init(&memcg->swap, NULL);
4158 page_counter_init(&memcg->memsw, NULL);
4159 page_counter_init(&memcg->kmem, NULL);
4160 page_counter_init(&memcg->tcpmem, NULL);
4162 * Deeper hierachy with use_hierarchy == false doesn't make
4163 * much sense so let cgroup subsystem know about this
4164 * unfortunate state in our controller.
4166 if (parent != root_mem_cgroup)
4167 memory_cgrp_subsys.broken_hierarchy = true;
4170 /* The following stuff does not apply to the root */
4172 root_mem_cgroup = memcg;
4176 error = memcg_online_kmem(memcg);
4180 if (cgroup_subsys_on_dfl(memory_cgrp_subsys) && !cgroup_memory_nosocket)
4181 static_branch_inc(&memcg_sockets_enabled_key);
4185 mem_cgroup_free(memcg);
4190 mem_cgroup_css_online(struct cgroup_subsys_state *css)
4192 if (css->id > MEM_CGROUP_ID_MAX)
4198 static void mem_cgroup_css_offline(struct cgroup_subsys_state *css)
4200 struct mem_cgroup *memcg = mem_cgroup_from_css(css);
4201 struct mem_cgroup_event *event, *tmp;
4204 * Unregister events and notify userspace.
4205 * Notify userspace about cgroup removing only after rmdir of cgroup
4206 * directory to avoid race between userspace and kernelspace.
4208 spin_lock(&memcg->event_list_lock);
4209 list_for_each_entry_safe(event, tmp, &memcg->event_list, list) {
4210 list_del_init(&event->list);
4211 schedule_work(&event->remove);
4213 spin_unlock(&memcg->event_list_lock);
4215 memcg_offline_kmem(memcg);
4216 wb_memcg_offline(memcg);
4219 static void mem_cgroup_css_released(struct cgroup_subsys_state *css)
4221 struct mem_cgroup *memcg = mem_cgroup_from_css(css);
4223 invalidate_reclaim_iterators(memcg);
4226 static void mem_cgroup_css_free(struct cgroup_subsys_state *css)
4228 struct mem_cgroup *memcg = mem_cgroup_from_css(css);
4230 if (cgroup_subsys_on_dfl(memory_cgrp_subsys) && !cgroup_memory_nosocket)
4231 static_branch_dec(&memcg_sockets_enabled_key);
4233 if (!cgroup_subsys_on_dfl(memory_cgrp_subsys) && memcg->tcpmem_active)
4234 static_branch_dec(&memcg_sockets_enabled_key);
4236 vmpressure_cleanup(&memcg->vmpressure);
4237 cancel_work_sync(&memcg->high_work);
4238 mem_cgroup_remove_from_trees(memcg);
4239 memcg_free_kmem(memcg);
4240 mem_cgroup_free(memcg);
4244 * mem_cgroup_css_reset - reset the states of a mem_cgroup
4245 * @css: the target css
4247 * Reset the states of the mem_cgroup associated with @css. This is
4248 * invoked when the userland requests disabling on the default hierarchy
4249 * but the memcg is pinned through dependency. The memcg should stop
4250 * applying policies and should revert to the vanilla state as it may be
4251 * made visible again.
4253 * The current implementation only resets the essential configurations.
4254 * This needs to be expanded to cover all the visible parts.
4256 static void mem_cgroup_css_reset(struct cgroup_subsys_state *css)
4258 struct mem_cgroup *memcg = mem_cgroup_from_css(css);
4260 page_counter_limit(&memcg->memory, PAGE_COUNTER_MAX);
4261 page_counter_limit(&memcg->swap, PAGE_COUNTER_MAX);
4262 page_counter_limit(&memcg->memsw, PAGE_COUNTER_MAX);
4263 page_counter_limit(&memcg->kmem, PAGE_COUNTER_MAX);
4264 page_counter_limit(&memcg->tcpmem, PAGE_COUNTER_MAX);
4266 memcg->high = PAGE_COUNTER_MAX;
4267 memcg->soft_limit = PAGE_COUNTER_MAX;
4268 memcg_wb_domain_size_changed(memcg);
4272 /* Handlers for move charge at task migration. */
4273 static int mem_cgroup_do_precharge(unsigned long count)
4277 /* Try a single bulk charge without reclaim first, kswapd may wake */
4278 ret = try_charge(mc.to, GFP_KERNEL & ~__GFP_DIRECT_RECLAIM, count);
4280 mc.precharge += count;
4284 /* Try charges one by one with reclaim */
4286 ret = try_charge(mc.to, GFP_KERNEL & ~__GFP_NORETRY, 1);
4296 * get_mctgt_type - get target type of moving charge
4297 * @vma: the vma the pte to be checked belongs
4298 * @addr: the address corresponding to the pte to be checked
4299 * @ptent: the pte to be checked
4300 * @target: the pointer the target page or swap ent will be stored(can be NULL)
4303 * 0(MC_TARGET_NONE): if the pte is not a target for move charge.
4304 * 1(MC_TARGET_PAGE): if the page corresponding to this pte is a target for
4305 * move charge. if @target is not NULL, the page is stored in target->page
4306 * with extra refcnt got(Callers should handle it).
4307 * 2(MC_TARGET_SWAP): if the swap entry corresponding to this pte is a
4308 * target for charge migration. if @target is not NULL, the entry is stored
4311 * Called with pte lock held.
4318 enum mc_target_type {
4324 static struct page *mc_handle_present_pte(struct vm_area_struct *vma,
4325 unsigned long addr, pte_t ptent)
4327 struct page *page = vm_normal_page(vma, addr, ptent);
4329 if (!page || !page_mapped(page))
4331 if (PageAnon(page)) {
4332 if (!(mc.flags & MOVE_ANON))
4335 if (!(mc.flags & MOVE_FILE))
4338 if (!get_page_unless_zero(page))
4345 static struct page *mc_handle_swap_pte(struct vm_area_struct *vma,
4346 unsigned long addr, pte_t ptent, swp_entry_t *entry)
4348 struct page *page = NULL;
4349 swp_entry_t ent = pte_to_swp_entry(ptent);
4351 if (!(mc.flags & MOVE_ANON) || non_swap_entry(ent))
4354 * Because lookup_swap_cache() updates some statistics counter,
4355 * we call find_get_page() with swapper_space directly.
4357 page = find_get_page(swap_address_space(ent), ent.val);
4358 if (do_memsw_account())
4359 entry->val = ent.val;
4364 static struct page *mc_handle_swap_pte(struct vm_area_struct *vma,
4365 unsigned long addr, pte_t ptent, swp_entry_t *entry)
4371 static struct page *mc_handle_file_pte(struct vm_area_struct *vma,
4372 unsigned long addr, pte_t ptent, swp_entry_t *entry)
4374 struct page *page = NULL;
4375 struct address_space *mapping;
4378 if (!vma->vm_file) /* anonymous vma */
4380 if (!(mc.flags & MOVE_FILE))
4383 mapping = vma->vm_file->f_mapping;
4384 pgoff = linear_page_index(vma, addr);
4386 /* page is moved even if it's not RSS of this task(page-faulted). */
4388 /* shmem/tmpfs may report page out on swap: account for that too. */
4389 if (shmem_mapping(mapping)) {
4390 page = find_get_entry(mapping, pgoff);
4391 if (radix_tree_exceptional_entry(page)) {
4392 swp_entry_t swp = radix_to_swp_entry(page);
4393 if (do_memsw_account())
4395 page = find_get_page(swap_address_space(swp), swp.val);
4398 page = find_get_page(mapping, pgoff);
4400 page = find_get_page(mapping, pgoff);
4406 * mem_cgroup_move_account - move account of the page
4408 * @nr_pages: number of regular pages (>1 for huge pages)
4409 * @from: mem_cgroup which the page is moved from.
4410 * @to: mem_cgroup which the page is moved to. @from != @to.
4412 * The caller must make sure the page is not on LRU (isolate_page() is useful.)
4414 * This function doesn't do "charge" to new cgroup and doesn't do "uncharge"
4417 static int mem_cgroup_move_account(struct page *page,
4419 struct mem_cgroup *from,
4420 struct mem_cgroup *to)
4422 unsigned long flags;
4423 unsigned int nr_pages = compound ? hpage_nr_pages(page) : 1;
4427 VM_BUG_ON(from == to);
4428 VM_BUG_ON_PAGE(PageLRU(page), page);
4429 VM_BUG_ON(compound && !PageTransHuge(page));
4432 * Prevent mem_cgroup_migrate() from looking at
4433 * page->mem_cgroup of its source page while we change it.
4436 if (!trylock_page(page))
4440 if (page->mem_cgroup != from)
4443 anon = PageAnon(page);
4445 spin_lock_irqsave(&from->move_lock, flags);
4447 if (!anon && page_mapped(page)) {
4448 __this_cpu_sub(from->stat->count[MEM_CGROUP_STAT_FILE_MAPPED],
4450 __this_cpu_add(to->stat->count[MEM_CGROUP_STAT_FILE_MAPPED],
4455 * move_lock grabbed above and caller set from->moving_account, so
4456 * mem_cgroup_update_page_stat() will serialize updates to PageDirty.
4457 * So mapping should be stable for dirty pages.
4459 if (!anon && PageDirty(page)) {
4460 struct address_space *mapping = page_mapping(page);
4462 if (mapping_cap_account_dirty(mapping)) {
4463 __this_cpu_sub(from->stat->count[MEM_CGROUP_STAT_DIRTY],
4465 __this_cpu_add(to->stat->count[MEM_CGROUP_STAT_DIRTY],
4470 if (PageWriteback(page)) {
4471 __this_cpu_sub(from->stat->count[MEM_CGROUP_STAT_WRITEBACK],
4473 __this_cpu_add(to->stat->count[MEM_CGROUP_STAT_WRITEBACK],
4478 * It is safe to change page->mem_cgroup here because the page
4479 * is referenced, charged, and isolated - we can't race with
4480 * uncharging, charging, migration, or LRU putback.
4483 /* caller should have done css_get */
4484 page->mem_cgroup = to;
4485 spin_unlock_irqrestore(&from->move_lock, flags);
4489 local_irq_disable();
4490 mem_cgroup_charge_statistics(to, page, compound, nr_pages);
4491 memcg_check_events(to, page);
4492 mem_cgroup_charge_statistics(from, page, compound, -nr_pages);
4493 memcg_check_events(from, page);
4501 static enum mc_target_type get_mctgt_type(struct vm_area_struct *vma,
4502 unsigned long addr, pte_t ptent, union mc_target *target)
4504 struct page *page = NULL;
4505 enum mc_target_type ret = MC_TARGET_NONE;
4506 swp_entry_t ent = { .val = 0 };
4508 if (pte_present(ptent))
4509 page = mc_handle_present_pte(vma, addr, ptent);
4510 else if (is_swap_pte(ptent))
4511 page = mc_handle_swap_pte(vma, addr, ptent, &ent);
4512 else if (pte_none(ptent))
4513 page = mc_handle_file_pte(vma, addr, ptent, &ent);
4515 if (!page && !ent.val)
4519 * Do only loose check w/o serialization.
4520 * mem_cgroup_move_account() checks the page is valid or
4521 * not under LRU exclusion.
4523 if (page->mem_cgroup == mc.from) {
4524 ret = MC_TARGET_PAGE;
4526 target->page = page;
4528 if (!ret || !target)
4531 /* There is a swap entry and a page doesn't exist or isn't charged */
4532 if (ent.val && !ret &&
4533 mem_cgroup_id(mc.from) == lookup_swap_cgroup_id(ent)) {
4534 ret = MC_TARGET_SWAP;
4541 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
4543 * We don't consider swapping or file mapped pages because THP does not
4544 * support them for now.
4545 * Caller should make sure that pmd_trans_huge(pmd) is true.
4547 static enum mc_target_type get_mctgt_type_thp(struct vm_area_struct *vma,
4548 unsigned long addr, pmd_t pmd, union mc_target *target)
4550 struct page *page = NULL;
4551 enum mc_target_type ret = MC_TARGET_NONE;
4553 page = pmd_page(pmd);
4554 VM_BUG_ON_PAGE(!page || !PageHead(page), page);
4555 if (!(mc.flags & MOVE_ANON))
4557 if (page->mem_cgroup == mc.from) {
4558 ret = MC_TARGET_PAGE;
4561 target->page = page;
4567 static inline enum mc_target_type get_mctgt_type_thp(struct vm_area_struct *vma,
4568 unsigned long addr, pmd_t pmd, union mc_target *target)
4570 return MC_TARGET_NONE;
4574 static int mem_cgroup_count_precharge_pte_range(pmd_t *pmd,
4575 unsigned long addr, unsigned long end,
4576 struct mm_walk *walk)
4578 struct vm_area_struct *vma = walk->vma;
4582 ptl = pmd_trans_huge_lock(pmd, vma);
4584 if (get_mctgt_type_thp(vma, addr, *pmd, NULL) == MC_TARGET_PAGE)
4585 mc.precharge += HPAGE_PMD_NR;
4590 if (pmd_trans_unstable(pmd))
4592 pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl);
4593 for (; addr != end; pte++, addr += PAGE_SIZE)
4594 if (get_mctgt_type(vma, addr, *pte, NULL))
4595 mc.precharge++; /* increment precharge temporarily */
4596 pte_unmap_unlock(pte - 1, ptl);
4602 static unsigned long mem_cgroup_count_precharge(struct mm_struct *mm)
4604 unsigned long precharge;
4606 struct mm_walk mem_cgroup_count_precharge_walk = {
4607 .pmd_entry = mem_cgroup_count_precharge_pte_range,
4610 down_read(&mm->mmap_sem);
4611 walk_page_range(0, ~0UL, &mem_cgroup_count_precharge_walk);
4612 up_read(&mm->mmap_sem);
4614 precharge = mc.precharge;
4620 static int mem_cgroup_precharge_mc(struct mm_struct *mm)
4622 unsigned long precharge = mem_cgroup_count_precharge(mm);
4624 VM_BUG_ON(mc.moving_task);
4625 mc.moving_task = current;
4626 return mem_cgroup_do_precharge(precharge);
4629 /* cancels all extra charges on mc.from and mc.to, and wakes up all waiters. */
4630 static void __mem_cgroup_clear_mc(void)
4632 struct mem_cgroup *from = mc.from;
4633 struct mem_cgroup *to = mc.to;
4635 /* we must uncharge all the leftover precharges from mc.to */
4637 cancel_charge(mc.to, mc.precharge);
4641 * we didn't uncharge from mc.from at mem_cgroup_move_account(), so
4642 * we must uncharge here.
4644 if (mc.moved_charge) {
4645 cancel_charge(mc.from, mc.moved_charge);
4646 mc.moved_charge = 0;
4648 /* we must fixup refcnts and charges */
4649 if (mc.moved_swap) {
4650 /* uncharge swap account from the old cgroup */
4651 if (!mem_cgroup_is_root(mc.from))
4652 page_counter_uncharge(&mc.from->memsw, mc.moved_swap);
4655 * we charged both to->memory and to->memsw, so we
4656 * should uncharge to->memory.
4658 if (!mem_cgroup_is_root(mc.to))
4659 page_counter_uncharge(&mc.to->memory, mc.moved_swap);
4661 css_put_many(&mc.from->css, mc.moved_swap);
4663 /* we've already done css_get(mc.to) */
4666 memcg_oom_recover(from);
4667 memcg_oom_recover(to);
4668 wake_up_all(&mc.waitq);
4671 static void mem_cgroup_clear_mc(void)
4674 * we must clear moving_task before waking up waiters at the end of
4677 mc.moving_task = NULL;
4678 __mem_cgroup_clear_mc();
4679 spin_lock(&mc.lock);
4682 spin_unlock(&mc.lock);
4685 static int mem_cgroup_can_attach(struct cgroup_taskset *tset)
4687 struct cgroup_subsys_state *css;
4688 struct mem_cgroup *memcg = NULL; /* unneeded init to make gcc happy */
4689 struct mem_cgroup *from;
4690 struct task_struct *leader, *p;
4691 struct mm_struct *mm;
4692 unsigned long move_flags;
4695 /* charge immigration isn't supported on the default hierarchy */
4696 if (cgroup_subsys_on_dfl(memory_cgrp_subsys))
4700 * Multi-process migrations only happen on the default hierarchy
4701 * where charge immigration is not used. Perform charge
4702 * immigration if @tset contains a leader and whine if there are
4706 cgroup_taskset_for_each_leader(leader, css, tset) {
4709 memcg = mem_cgroup_from_css(css);
4715 * We are now commited to this value whatever it is. Changes in this
4716 * tunable will only affect upcoming migrations, not the current one.
4717 * So we need to save it, and keep it going.
4719 move_flags = READ_ONCE(memcg->move_charge_at_immigrate);
4723 from = mem_cgroup_from_task(p);
4725 VM_BUG_ON(from == memcg);
4727 mm = get_task_mm(p);
4730 /* We move charges only when we move a owner of the mm */
4731 if (mm->owner == p) {
4734 VM_BUG_ON(mc.precharge);
4735 VM_BUG_ON(mc.moved_charge);
4736 VM_BUG_ON(mc.moved_swap);
4738 spin_lock(&mc.lock);
4741 mc.flags = move_flags;
4742 spin_unlock(&mc.lock);
4743 /* We set mc.moving_task later */
4745 ret = mem_cgroup_precharge_mc(mm);
4747 mem_cgroup_clear_mc();
4753 static void mem_cgroup_cancel_attach(struct cgroup_taskset *tset)
4756 mem_cgroup_clear_mc();
4759 static int mem_cgroup_move_charge_pte_range(pmd_t *pmd,
4760 unsigned long addr, unsigned long end,
4761 struct mm_walk *walk)
4764 struct vm_area_struct *vma = walk->vma;
4767 enum mc_target_type target_type;
4768 union mc_target target;
4771 ptl = pmd_trans_huge_lock(pmd, vma);
4773 if (mc.precharge < HPAGE_PMD_NR) {
4777 target_type = get_mctgt_type_thp(vma, addr, *pmd, &target);
4778 if (target_type == MC_TARGET_PAGE) {
4780 if (!isolate_lru_page(page)) {
4781 if (!mem_cgroup_move_account(page, true,
4783 mc.precharge -= HPAGE_PMD_NR;
4784 mc.moved_charge += HPAGE_PMD_NR;
4786 putback_lru_page(page);
4794 if (pmd_trans_unstable(pmd))
4797 pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl);
4798 for (; addr != end; addr += PAGE_SIZE) {
4799 pte_t ptent = *(pte++);
4805 switch (get_mctgt_type(vma, addr, ptent, &target)) {
4806 case MC_TARGET_PAGE:
4809 * We can have a part of the split pmd here. Moving it
4810 * can be done but it would be too convoluted so simply
4811 * ignore such a partial THP and keep it in original
4812 * memcg. There should be somebody mapping the head.
4814 if (PageTransCompound(page))
4816 if (isolate_lru_page(page))
4818 if (!mem_cgroup_move_account(page, false,
4821 /* we uncharge from mc.from later. */
4824 putback_lru_page(page);
4825 put: /* get_mctgt_type() gets the page */
4828 case MC_TARGET_SWAP:
4830 if (!mem_cgroup_move_swap_account(ent, mc.from, mc.to)) {
4832 /* we fixup refcnts and charges later. */
4840 pte_unmap_unlock(pte - 1, ptl);
4845 * We have consumed all precharges we got in can_attach().
4846 * We try charge one by one, but don't do any additional
4847 * charges to mc.to if we have failed in charge once in attach()
4850 ret = mem_cgroup_do_precharge(1);
4858 static void mem_cgroup_move_charge(struct mm_struct *mm)
4860 struct mm_walk mem_cgroup_move_charge_walk = {
4861 .pmd_entry = mem_cgroup_move_charge_pte_range,
4865 lru_add_drain_all();
4867 * Signal lock_page_memcg() to take the memcg's move_lock
4868 * while we're moving its pages to another memcg. Then wait
4869 * for already started RCU-only updates to finish.
4871 atomic_inc(&mc.from->moving_account);
4874 if (unlikely(!down_read_trylock(&mm->mmap_sem))) {
4876 * Someone who are holding the mmap_sem might be waiting in
4877 * waitq. So we cancel all extra charges, wake up all waiters,
4878 * and retry. Because we cancel precharges, we might not be able
4879 * to move enough charges, but moving charge is a best-effort
4880 * feature anyway, so it wouldn't be a big problem.
4882 __mem_cgroup_clear_mc();
4887 * When we have consumed all precharges and failed in doing
4888 * additional charge, the page walk just aborts.
4890 walk_page_range(0, ~0UL, &mem_cgroup_move_charge_walk);
4891 up_read(&mm->mmap_sem);
4892 atomic_dec(&mc.from->moving_account);
4895 static void mem_cgroup_move_task(struct cgroup_taskset *tset)
4897 struct cgroup_subsys_state *css;
4898 struct task_struct *p = cgroup_taskset_first(tset, &css);
4899 struct mm_struct *mm = get_task_mm(p);
4903 mem_cgroup_move_charge(mm);
4907 mem_cgroup_clear_mc();
4909 #else /* !CONFIG_MMU */
4910 static int mem_cgroup_can_attach(struct cgroup_taskset *tset)
4914 static void mem_cgroup_cancel_attach(struct cgroup_taskset *tset)
4917 static void mem_cgroup_move_task(struct cgroup_taskset *tset)
4923 * Cgroup retains root cgroups across [un]mount cycles making it necessary
4924 * to verify whether we're attached to the default hierarchy on each mount
4927 static void mem_cgroup_bind(struct cgroup_subsys_state *root_css)
4930 * use_hierarchy is forced on the default hierarchy. cgroup core
4931 * guarantees that @root doesn't have any children, so turning it
4932 * on for the root memcg is enough.
4934 if (cgroup_subsys_on_dfl(memory_cgrp_subsys))
4935 root_mem_cgroup->use_hierarchy = true;
4937 root_mem_cgroup->use_hierarchy = false;
4940 static u64 memory_current_read(struct cgroup_subsys_state *css,
4943 struct mem_cgroup *memcg = mem_cgroup_from_css(css);
4945 return (u64)page_counter_read(&memcg->memory) * PAGE_SIZE;
4948 static int memory_low_show(struct seq_file *m, void *v)
4950 struct mem_cgroup *memcg = mem_cgroup_from_css(seq_css(m));
4951 unsigned long low = READ_ONCE(memcg->low);
4953 if (low == PAGE_COUNTER_MAX)
4954 seq_puts(m, "max\n");
4956 seq_printf(m, "%llu\n", (u64)low * PAGE_SIZE);
4961 static ssize_t memory_low_write(struct kernfs_open_file *of,
4962 char *buf, size_t nbytes, loff_t off)
4964 struct mem_cgroup *memcg = mem_cgroup_from_css(of_css(of));
4968 buf = strstrip(buf);
4969 err = page_counter_memparse(buf, "max", &low);
4978 static int memory_high_show(struct seq_file *m, void *v)
4980 struct mem_cgroup *memcg = mem_cgroup_from_css(seq_css(m));
4981 unsigned long high = READ_ONCE(memcg->high);
4983 if (high == PAGE_COUNTER_MAX)
4984 seq_puts(m, "max\n");
4986 seq_printf(m, "%llu\n", (u64)high * PAGE_SIZE);
4991 static ssize_t memory_high_write(struct kernfs_open_file *of,
4992 char *buf, size_t nbytes, loff_t off)
4994 struct mem_cgroup *memcg = mem_cgroup_from_css(of_css(of));
4998 buf = strstrip(buf);
4999 err = page_counter_memparse(buf, "max", &high);
5005 memcg_wb_domain_size_changed(memcg);
5009 static int memory_max_show(struct seq_file *m, void *v)
5011 struct mem_cgroup *memcg = mem_cgroup_from_css(seq_css(m));
5012 unsigned long max = READ_ONCE(memcg->memory.limit);
5014 if (max == PAGE_COUNTER_MAX)
5015 seq_puts(m, "max\n");
5017 seq_printf(m, "%llu\n", (u64)max * PAGE_SIZE);
5022 static ssize_t memory_max_write(struct kernfs_open_file *of,
5023 char *buf, size_t nbytes, loff_t off)
5025 struct mem_cgroup *memcg = mem_cgroup_from_css(of_css(of));
5029 buf = strstrip(buf);
5030 err = page_counter_memparse(buf, "max", &max);
5034 err = mem_cgroup_resize_limit(memcg, max);
5038 memcg_wb_domain_size_changed(memcg);
5042 static int memory_events_show(struct seq_file *m, void *v)
5044 struct mem_cgroup *memcg = mem_cgroup_from_css(seq_css(m));
5046 seq_printf(m, "low %lu\n", mem_cgroup_read_events(memcg, MEMCG_LOW));
5047 seq_printf(m, "high %lu\n", mem_cgroup_read_events(memcg, MEMCG_HIGH));
5048 seq_printf(m, "max %lu\n", mem_cgroup_read_events(memcg, MEMCG_MAX));
5049 seq_printf(m, "oom %lu\n", mem_cgroup_read_events(memcg, MEMCG_OOM));
5054 static int memory_stat_show(struct seq_file *m, void *v)
5056 struct mem_cgroup *memcg = mem_cgroup_from_css(seq_css(m));
5057 unsigned long stat[MEMCG_NR_STAT];
5058 unsigned long events[MEMCG_NR_EVENTS];
5062 * Provide statistics on the state of the memory subsystem as
5063 * well as cumulative event counters that show past behavior.
5065 * This list is ordered following a combination of these gradients:
5066 * 1) generic big picture -> specifics and details
5067 * 2) reflecting userspace activity -> reflecting kernel heuristics
5069 * Current memory state:
5072 tree_stat(memcg, stat);
5073 tree_events(memcg, events);
5075 seq_printf(m, "anon %llu\n",
5076 (u64)stat[MEM_CGROUP_STAT_RSS] * PAGE_SIZE);
5077 seq_printf(m, "file %llu\n",
5078 (u64)stat[MEM_CGROUP_STAT_CACHE] * PAGE_SIZE);
5079 seq_printf(m, "kernel_stack %llu\n",
5080 (u64)stat[MEMCG_KERNEL_STACK] * PAGE_SIZE);
5081 seq_printf(m, "slab %llu\n",
5082 (u64)(stat[MEMCG_SLAB_RECLAIMABLE] +
5083 stat[MEMCG_SLAB_UNRECLAIMABLE]) * PAGE_SIZE);
5084 seq_printf(m, "sock %llu\n",
5085 (u64)stat[MEMCG_SOCK] * PAGE_SIZE);
5087 seq_printf(m, "file_mapped %llu\n",
5088 (u64)stat[MEM_CGROUP_STAT_FILE_MAPPED] * PAGE_SIZE);
5089 seq_printf(m, "file_dirty %llu\n",
5090 (u64)stat[MEM_CGROUP_STAT_DIRTY] * PAGE_SIZE);
5091 seq_printf(m, "file_writeback %llu\n",
5092 (u64)stat[MEM_CGROUP_STAT_WRITEBACK] * PAGE_SIZE);
5094 for (i = 0; i < NR_LRU_LISTS; i++) {
5095 struct mem_cgroup *mi;
5096 unsigned long val = 0;
5098 for_each_mem_cgroup_tree(mi, memcg)
5099 val += mem_cgroup_nr_lru_pages(mi, BIT(i));
5100 seq_printf(m, "%s %llu\n",
5101 mem_cgroup_lru_names[i], (u64)val * PAGE_SIZE);
5104 seq_printf(m, "slab_reclaimable %llu\n",
5105 (u64)stat[MEMCG_SLAB_RECLAIMABLE] * PAGE_SIZE);
5106 seq_printf(m, "slab_unreclaimable %llu\n",
5107 (u64)stat[MEMCG_SLAB_UNRECLAIMABLE] * PAGE_SIZE);
5109 /* Accumulated memory events */
5111 seq_printf(m, "pgfault %lu\n",
5112 events[MEM_CGROUP_EVENTS_PGFAULT]);
5113 seq_printf(m, "pgmajfault %lu\n",
5114 events[MEM_CGROUP_EVENTS_PGMAJFAULT]);
5119 static struct cftype memory_files[] = {
5122 .flags = CFTYPE_NOT_ON_ROOT,
5123 .read_u64 = memory_current_read,
5127 .flags = CFTYPE_NOT_ON_ROOT,
5128 .seq_show = memory_low_show,
5129 .write = memory_low_write,
5133 .flags = CFTYPE_NOT_ON_ROOT,
5134 .seq_show = memory_high_show,
5135 .write = memory_high_write,
5139 .flags = CFTYPE_NOT_ON_ROOT,
5140 .seq_show = memory_max_show,
5141 .write = memory_max_write,
5145 .flags = CFTYPE_NOT_ON_ROOT,
5146 .file_offset = offsetof(struct mem_cgroup, events_file),
5147 .seq_show = memory_events_show,
5151 .flags = CFTYPE_NOT_ON_ROOT,
5152 .seq_show = memory_stat_show,
5157 struct cgroup_subsys memory_cgrp_subsys = {
5158 .css_alloc = mem_cgroup_css_alloc,
5159 .css_online = mem_cgroup_css_online,
5160 .css_offline = mem_cgroup_css_offline,
5161 .css_released = mem_cgroup_css_released,
5162 .css_free = mem_cgroup_css_free,
5163 .css_reset = mem_cgroup_css_reset,
5164 .can_attach = mem_cgroup_can_attach,
5165 .cancel_attach = mem_cgroup_cancel_attach,
5166 .attach = mem_cgroup_move_task,
5167 .bind = mem_cgroup_bind,
5168 .dfl_cftypes = memory_files,
5169 .legacy_cftypes = mem_cgroup_legacy_files,
5174 * mem_cgroup_low - check if memory consumption is below the normal range
5175 * @root: the highest ancestor to consider
5176 * @memcg: the memory cgroup to check
5178 * Returns %true if memory consumption of @memcg, and that of all
5179 * configurable ancestors up to @root, is below the normal range.
5181 bool mem_cgroup_low(struct mem_cgroup *root, struct mem_cgroup *memcg)
5183 if (mem_cgroup_disabled())
5187 * The toplevel group doesn't have a configurable range, so
5188 * it's never low when looked at directly, and it is not
5189 * considered an ancestor when assessing the hierarchy.
5192 if (memcg == root_mem_cgroup)
5195 if (page_counter_read(&memcg->memory) >= memcg->low)
5198 while (memcg != root) {
5199 memcg = parent_mem_cgroup(memcg);
5201 if (memcg == root_mem_cgroup)
5204 if (page_counter_read(&memcg->memory) >= memcg->low)
5211 * mem_cgroup_try_charge - try charging a page
5212 * @page: page to charge
5213 * @mm: mm context of the victim
5214 * @gfp_mask: reclaim mode
5215 * @memcgp: charged memcg return
5217 * Try to charge @page to the memcg that @mm belongs to, reclaiming
5218 * pages according to @gfp_mask if necessary.
5220 * Returns 0 on success, with *@memcgp pointing to the charged memcg.
5221 * Otherwise, an error code is returned.
5223 * After page->mapping has been set up, the caller must finalize the
5224 * charge with mem_cgroup_commit_charge(). Or abort the transaction
5225 * with mem_cgroup_cancel_charge() in case page instantiation fails.
5227 int mem_cgroup_try_charge(struct page *page, struct mm_struct *mm,
5228 gfp_t gfp_mask, struct mem_cgroup **memcgp,
5231 struct mem_cgroup *memcg = NULL;
5232 unsigned int nr_pages = compound ? hpage_nr_pages(page) : 1;
5235 if (mem_cgroup_disabled())
5238 if (PageSwapCache(page)) {
5240 * Every swap fault against a single page tries to charge the
5241 * page, bail as early as possible. shmem_unuse() encounters
5242 * already charged pages, too. The USED bit is protected by
5243 * the page lock, which serializes swap cache removal, which
5244 * in turn serializes uncharging.
5246 VM_BUG_ON_PAGE(!PageLocked(page), page);
5247 if (page->mem_cgroup)
5250 if (do_swap_account) {
5251 swp_entry_t ent = { .val = page_private(page), };
5252 unsigned short id = lookup_swap_cgroup_id(ent);
5255 memcg = mem_cgroup_from_id(id);
5256 if (memcg && !css_tryget_online(&memcg->css))
5263 memcg = get_mem_cgroup_from_mm(mm);
5265 ret = try_charge(memcg, gfp_mask, nr_pages);
5267 css_put(&memcg->css);
5274 * mem_cgroup_commit_charge - commit a page charge
5275 * @page: page to charge
5276 * @memcg: memcg to charge the page to
5277 * @lrucare: page might be on LRU already
5279 * Finalize a charge transaction started by mem_cgroup_try_charge(),
5280 * after page->mapping has been set up. This must happen atomically
5281 * as part of the page instantiation, i.e. under the page table lock
5282 * for anonymous pages, under the page lock for page and swap cache.
5284 * In addition, the page must not be on the LRU during the commit, to
5285 * prevent racing with task migration. If it might be, use @lrucare.
5287 * Use mem_cgroup_cancel_charge() to cancel the transaction instead.
5289 void mem_cgroup_commit_charge(struct page *page, struct mem_cgroup *memcg,
5290 bool lrucare, bool compound)
5292 unsigned int nr_pages = compound ? hpage_nr_pages(page) : 1;
5294 VM_BUG_ON_PAGE(!page->mapping, page);
5295 VM_BUG_ON_PAGE(PageLRU(page) && !lrucare, page);
5297 if (mem_cgroup_disabled())
5300 * Swap faults will attempt to charge the same page multiple
5301 * times. But reuse_swap_page() might have removed the page
5302 * from swapcache already, so we can't check PageSwapCache().
5307 commit_charge(page, memcg, lrucare);
5309 local_irq_disable();
5310 mem_cgroup_charge_statistics(memcg, page, compound, nr_pages);
5311 memcg_check_events(memcg, page);
5314 if (do_memsw_account() && PageSwapCache(page)) {
5315 swp_entry_t entry = { .val = page_private(page) };
5317 * The swap entry might not get freed for a long time,
5318 * let's not wait for it. The page already received a
5319 * memory+swap charge, drop the swap entry duplicate.
5321 mem_cgroup_uncharge_swap(entry);
5326 * mem_cgroup_cancel_charge - cancel a page charge
5327 * @page: page to charge
5328 * @memcg: memcg to charge the page to
5330 * Cancel a charge transaction started by mem_cgroup_try_charge().
5332 void mem_cgroup_cancel_charge(struct page *page, struct mem_cgroup *memcg,
5335 unsigned int nr_pages = compound ? hpage_nr_pages(page) : 1;
5337 if (mem_cgroup_disabled())
5340 * Swap faults will attempt to charge the same page multiple
5341 * times. But reuse_swap_page() might have removed the page
5342 * from swapcache already, so we can't check PageSwapCache().
5347 cancel_charge(memcg, nr_pages);
5350 static void uncharge_batch(struct mem_cgroup *memcg, unsigned long pgpgout,
5351 unsigned long nr_anon, unsigned long nr_file,
5352 unsigned long nr_huge, struct page *dummy_page)
5354 unsigned long nr_pages = nr_anon + nr_file;
5355 unsigned long flags;
5357 if (!mem_cgroup_is_root(memcg)) {
5358 page_counter_uncharge(&memcg->memory, nr_pages);
5359 if (do_memsw_account())
5360 page_counter_uncharge(&memcg->memsw, nr_pages);
5361 memcg_oom_recover(memcg);
5364 local_irq_save(flags);
5365 __this_cpu_sub(memcg->stat->count[MEM_CGROUP_STAT_RSS], nr_anon);
5366 __this_cpu_sub(memcg->stat->count[MEM_CGROUP_STAT_CACHE], nr_file);
5367 __this_cpu_sub(memcg->stat->count[MEM_CGROUP_STAT_RSS_HUGE], nr_huge);
5368 __this_cpu_add(memcg->stat->events[MEM_CGROUP_EVENTS_PGPGOUT], pgpgout);
5369 __this_cpu_add(memcg->stat->nr_page_events, nr_pages);
5370 memcg_check_events(memcg, dummy_page);
5371 local_irq_restore(flags);
5373 if (!mem_cgroup_is_root(memcg))
5374 css_put_many(&memcg->css, nr_pages);
5377 static void uncharge_list(struct list_head *page_list)
5379 struct mem_cgroup *memcg = NULL;
5380 unsigned long nr_anon = 0;
5381 unsigned long nr_file = 0;
5382 unsigned long nr_huge = 0;
5383 unsigned long pgpgout = 0;
5384 struct list_head *next;
5387 next = page_list->next;
5389 unsigned int nr_pages = 1;
5391 page = list_entry(next, struct page, lru);
5392 next = page->lru.next;
5394 VM_BUG_ON_PAGE(PageLRU(page), page);
5395 VM_BUG_ON_PAGE(page_count(page), page);
5397 if (!page->mem_cgroup)
5401 * Nobody should be changing or seriously looking at
5402 * page->mem_cgroup at this point, we have fully
5403 * exclusive access to the page.
5406 if (memcg != page->mem_cgroup) {
5408 uncharge_batch(memcg, pgpgout, nr_anon, nr_file,
5410 pgpgout = nr_anon = nr_file = nr_huge = 0;
5412 memcg = page->mem_cgroup;
5415 if (PageTransHuge(page)) {
5416 nr_pages <<= compound_order(page);
5417 VM_BUG_ON_PAGE(!PageTransHuge(page), page);
5418 nr_huge += nr_pages;
5422 nr_anon += nr_pages;
5424 nr_file += nr_pages;
5426 page->mem_cgroup = NULL;
5429 } while (next != page_list);
5432 uncharge_batch(memcg, pgpgout, nr_anon, nr_file,
5437 * mem_cgroup_uncharge - uncharge a page
5438 * @page: page to uncharge
5440 * Uncharge a page previously charged with mem_cgroup_try_charge() and
5441 * mem_cgroup_commit_charge().
5443 void mem_cgroup_uncharge(struct page *page)
5445 if (mem_cgroup_disabled())
5448 /* Don't touch page->lru of any random page, pre-check: */
5449 if (!page->mem_cgroup)
5452 INIT_LIST_HEAD(&page->lru);
5453 uncharge_list(&page->lru);
5457 * mem_cgroup_uncharge_list - uncharge a list of page
5458 * @page_list: list of pages to uncharge
5460 * Uncharge a list of pages previously charged with
5461 * mem_cgroup_try_charge() and mem_cgroup_commit_charge().
5463 void mem_cgroup_uncharge_list(struct list_head *page_list)
5465 if (mem_cgroup_disabled())
5468 if (!list_empty(page_list))
5469 uncharge_list(page_list);
5473 * mem_cgroup_migrate - charge a page's replacement
5474 * @oldpage: currently circulating page
5475 * @newpage: replacement page
5477 * Charge @newpage as a replacement page for @oldpage. @oldpage will
5478 * be uncharged upon free.
5480 * Both pages must be locked, @newpage->mapping must be set up.
5482 void mem_cgroup_migrate(struct page *oldpage, struct page *newpage)
5484 struct mem_cgroup *memcg;
5485 unsigned int nr_pages;
5488 VM_BUG_ON_PAGE(!PageLocked(oldpage), oldpage);
5489 VM_BUG_ON_PAGE(!PageLocked(newpage), newpage);
5490 VM_BUG_ON_PAGE(PageAnon(oldpage) != PageAnon(newpage), newpage);
5491 VM_BUG_ON_PAGE(PageTransHuge(oldpage) != PageTransHuge(newpage),
5494 if (mem_cgroup_disabled())
5497 /* Page cache replacement: new page already charged? */
5498 if (newpage->mem_cgroup)
5501 /* Swapcache readahead pages can get replaced before being charged */
5502 memcg = oldpage->mem_cgroup;
5506 /* Force-charge the new page. The old one will be freed soon */
5507 compound = PageTransHuge(newpage);
5508 nr_pages = compound ? hpage_nr_pages(newpage) : 1;
5510 page_counter_charge(&memcg->memory, nr_pages);
5511 if (do_memsw_account())
5512 page_counter_charge(&memcg->memsw, nr_pages);
5513 css_get_many(&memcg->css, nr_pages);
5515 commit_charge(newpage, memcg, false);
5517 local_irq_disable();
5518 mem_cgroup_charge_statistics(memcg, newpage, compound, nr_pages);
5519 memcg_check_events(memcg, newpage);
5523 DEFINE_STATIC_KEY_FALSE(memcg_sockets_enabled_key);
5524 EXPORT_SYMBOL(memcg_sockets_enabled_key);
5526 void sock_update_memcg(struct sock *sk)
5528 struct mem_cgroup *memcg;
5530 /* Socket cloning can throw us here with sk_cgrp already
5531 * filled. It won't however, necessarily happen from
5532 * process context. So the test for root memcg given
5533 * the current task's memcg won't help us in this case.
5535 * Respecting the original socket's memcg is a better
5536 * decision in this case.
5539 BUG_ON(mem_cgroup_is_root(sk->sk_memcg));
5540 css_get(&sk->sk_memcg->css);
5545 memcg = mem_cgroup_from_task(current);
5546 if (memcg == root_mem_cgroup)
5548 if (!cgroup_subsys_on_dfl(memory_cgrp_subsys) && !memcg->tcpmem_active)
5550 if (css_tryget_online(&memcg->css))
5551 sk->sk_memcg = memcg;
5555 EXPORT_SYMBOL(sock_update_memcg);
5557 void sock_release_memcg(struct sock *sk)
5559 WARN_ON(!sk->sk_memcg);
5560 css_put(&sk->sk_memcg->css);
5564 * mem_cgroup_charge_skmem - charge socket memory
5565 * @memcg: memcg to charge
5566 * @nr_pages: number of pages to charge
5568 * Charges @nr_pages to @memcg. Returns %true if the charge fit within
5569 * @memcg's configured limit, %false if the charge had to be forced.
5571 bool mem_cgroup_charge_skmem(struct mem_cgroup *memcg, unsigned int nr_pages)
5573 gfp_t gfp_mask = GFP_KERNEL;
5575 if (!cgroup_subsys_on_dfl(memory_cgrp_subsys)) {
5576 struct page_counter *fail;
5578 if (page_counter_try_charge(&memcg->tcpmem, nr_pages, &fail)) {
5579 memcg->tcpmem_pressure = 0;
5582 page_counter_charge(&memcg->tcpmem, nr_pages);
5583 memcg->tcpmem_pressure = 1;
5587 /* Don't block in the packet receive path */
5589 gfp_mask = GFP_NOWAIT;
5591 this_cpu_add(memcg->stat->count[MEMCG_SOCK], nr_pages);
5593 if (try_charge(memcg, gfp_mask, nr_pages) == 0)
5596 try_charge(memcg, gfp_mask|__GFP_NOFAIL, nr_pages);
5601 * mem_cgroup_uncharge_skmem - uncharge socket memory
5602 * @memcg - memcg to uncharge
5603 * @nr_pages - number of pages to uncharge
5605 void mem_cgroup_uncharge_skmem(struct mem_cgroup *memcg, unsigned int nr_pages)
5607 if (!cgroup_subsys_on_dfl(memory_cgrp_subsys)) {
5608 page_counter_uncharge(&memcg->tcpmem, nr_pages);
5612 this_cpu_sub(memcg->stat->count[MEMCG_SOCK], nr_pages);
5614 page_counter_uncharge(&memcg->memory, nr_pages);
5615 css_put_many(&memcg->css, nr_pages);
5618 static int __init cgroup_memory(char *s)
5622 while ((token = strsep(&s, ",")) != NULL) {
5625 if (!strcmp(token, "nosocket"))
5626 cgroup_memory_nosocket = true;
5627 if (!strcmp(token, "nokmem"))
5628 cgroup_memory_nokmem = true;
5632 __setup("cgroup.memory=", cgroup_memory);
5635 * subsys_initcall() for memory controller.
5637 * Some parts like hotcpu_notifier() have to be initialized from this context
5638 * because of lock dependencies (cgroup_lock -> cpu hotplug) but basically
5639 * everything that doesn't depend on a specific mem_cgroup structure should
5640 * be initialized from here.
5642 static int __init mem_cgroup_init(void)
5646 hotcpu_notifier(memcg_cpu_hotplug_callback, 0);
5648 for_each_possible_cpu(cpu)
5649 INIT_WORK(&per_cpu_ptr(&memcg_stock, cpu)->work,
5652 for_each_node(node) {
5653 struct mem_cgroup_tree_per_node *rtpn;
5656 rtpn = kzalloc_node(sizeof(*rtpn), GFP_KERNEL,
5657 node_online(node) ? node : NUMA_NO_NODE);
5659 for (zone = 0; zone < MAX_NR_ZONES; zone++) {
5660 struct mem_cgroup_tree_per_zone *rtpz;
5662 rtpz = &rtpn->rb_tree_per_zone[zone];
5663 rtpz->rb_root = RB_ROOT;
5664 spin_lock_init(&rtpz->lock);
5666 soft_limit_tree.rb_tree_per_node[node] = rtpn;
5671 subsys_initcall(mem_cgroup_init);
5673 #ifdef CONFIG_MEMCG_SWAP
5675 * mem_cgroup_swapout - transfer a memsw charge to swap
5676 * @page: page whose memsw charge to transfer
5677 * @entry: swap entry to move the charge to
5679 * Transfer the memsw charge of @page to @entry.
5681 void mem_cgroup_swapout(struct page *page, swp_entry_t entry)
5683 struct mem_cgroup *memcg;
5684 unsigned short oldid;
5686 VM_BUG_ON_PAGE(PageLRU(page), page);
5687 VM_BUG_ON_PAGE(page_count(page), page);
5689 if (!do_memsw_account())
5692 memcg = page->mem_cgroup;
5694 /* Readahead page, never charged */
5698 oldid = swap_cgroup_record(entry, mem_cgroup_id(memcg));
5699 VM_BUG_ON_PAGE(oldid, page);
5700 mem_cgroup_swap_statistics(memcg, true);
5702 page->mem_cgroup = NULL;
5704 if (!mem_cgroup_is_root(memcg))
5705 page_counter_uncharge(&memcg->memory, 1);
5708 * Interrupts should be disabled here because the caller holds the
5709 * mapping->tree_lock lock which is taken with interrupts-off. It is
5710 * important here to have the interrupts disabled because it is the
5711 * only synchronisation we have for udpating the per-CPU variables.
5713 VM_BUG_ON(!irqs_disabled());
5714 mem_cgroup_charge_statistics(memcg, page, false, -1);
5715 memcg_check_events(memcg, page);
5719 * mem_cgroup_try_charge_swap - try charging a swap entry
5720 * @page: page being added to swap
5721 * @entry: swap entry to charge
5723 * Try to charge @entry to the memcg that @page belongs to.
5725 * Returns 0 on success, -ENOMEM on failure.
5727 int mem_cgroup_try_charge_swap(struct page *page, swp_entry_t entry)
5729 struct mem_cgroup *memcg;
5730 struct page_counter *counter;
5731 unsigned short oldid;
5733 if (!cgroup_subsys_on_dfl(memory_cgrp_subsys) || !do_swap_account)
5736 memcg = page->mem_cgroup;
5738 /* Readahead page, never charged */
5742 if (!mem_cgroup_is_root(memcg) &&
5743 !page_counter_try_charge(&memcg->swap, 1, &counter))
5746 oldid = swap_cgroup_record(entry, mem_cgroup_id(memcg));
5747 VM_BUG_ON_PAGE(oldid, page);
5748 mem_cgroup_swap_statistics(memcg, true);
5750 css_get(&memcg->css);
5755 * mem_cgroup_uncharge_swap - uncharge a swap entry
5756 * @entry: swap entry to uncharge
5758 * Drop the swap charge associated with @entry.
5760 void mem_cgroup_uncharge_swap(swp_entry_t entry)
5762 struct mem_cgroup *memcg;
5765 if (!do_swap_account)
5768 id = swap_cgroup_record(entry, 0);
5770 memcg = mem_cgroup_from_id(id);
5772 if (!mem_cgroup_is_root(memcg)) {
5773 if (cgroup_subsys_on_dfl(memory_cgrp_subsys))
5774 page_counter_uncharge(&memcg->swap, 1);
5776 page_counter_uncharge(&memcg->memsw, 1);
5778 mem_cgroup_swap_statistics(memcg, false);
5779 css_put(&memcg->css);
5784 long mem_cgroup_get_nr_swap_pages(struct mem_cgroup *memcg)
5786 long nr_swap_pages = get_nr_swap_pages();
5788 if (!do_swap_account || !cgroup_subsys_on_dfl(memory_cgrp_subsys))
5789 return nr_swap_pages;
5790 for (; memcg != root_mem_cgroup; memcg = parent_mem_cgroup(memcg))
5791 nr_swap_pages = min_t(long, nr_swap_pages,
5792 READ_ONCE(memcg->swap.limit) -
5793 page_counter_read(&memcg->swap));
5794 return nr_swap_pages;
5797 bool mem_cgroup_swap_full(struct page *page)
5799 struct mem_cgroup *memcg;
5801 VM_BUG_ON_PAGE(!PageLocked(page), page);
5805 if (!do_swap_account || !cgroup_subsys_on_dfl(memory_cgrp_subsys))
5808 memcg = page->mem_cgroup;
5812 for (; memcg != root_mem_cgroup; memcg = parent_mem_cgroup(memcg))
5813 if (page_counter_read(&memcg->swap) * 2 >= memcg->swap.limit)
5819 /* for remember boot option*/
5820 #ifdef CONFIG_MEMCG_SWAP_ENABLED
5821 static int really_do_swap_account __initdata = 1;
5823 static int really_do_swap_account __initdata;
5826 static int __init enable_swap_account(char *s)
5828 if (!strcmp(s, "1"))
5829 really_do_swap_account = 1;
5830 else if (!strcmp(s, "0"))
5831 really_do_swap_account = 0;
5834 __setup("swapaccount=", enable_swap_account);
5836 static u64 swap_current_read(struct cgroup_subsys_state *css,
5839 struct mem_cgroup *memcg = mem_cgroup_from_css(css);
5841 return (u64)page_counter_read(&memcg->swap) * PAGE_SIZE;
5844 static int swap_max_show(struct seq_file *m, void *v)
5846 struct mem_cgroup *memcg = mem_cgroup_from_css(seq_css(m));
5847 unsigned long max = READ_ONCE(memcg->swap.limit);
5849 if (max == PAGE_COUNTER_MAX)
5850 seq_puts(m, "max\n");
5852 seq_printf(m, "%llu\n", (u64)max * PAGE_SIZE);
5857 static ssize_t swap_max_write(struct kernfs_open_file *of,
5858 char *buf, size_t nbytes, loff_t off)
5860 struct mem_cgroup *memcg = mem_cgroup_from_css(of_css(of));
5864 buf = strstrip(buf);
5865 err = page_counter_memparse(buf, "max", &max);
5869 mutex_lock(&memcg_limit_mutex);
5870 err = page_counter_limit(&memcg->swap, max);
5871 mutex_unlock(&memcg_limit_mutex);
5878 static struct cftype swap_files[] = {
5880 .name = "swap.current",
5881 .flags = CFTYPE_NOT_ON_ROOT,
5882 .read_u64 = swap_current_read,
5886 .flags = CFTYPE_NOT_ON_ROOT,
5887 .seq_show = swap_max_show,
5888 .write = swap_max_write,
5893 static struct cftype memsw_cgroup_files[] = {
5895 .name = "memsw.usage_in_bytes",
5896 .private = MEMFILE_PRIVATE(_MEMSWAP, RES_USAGE),
5897 .read_u64 = mem_cgroup_read_u64,
5900 .name = "memsw.max_usage_in_bytes",
5901 .private = MEMFILE_PRIVATE(_MEMSWAP, RES_MAX_USAGE),
5902 .write = mem_cgroup_reset,
5903 .read_u64 = mem_cgroup_read_u64,
5906 .name = "memsw.limit_in_bytes",
5907 .private = MEMFILE_PRIVATE(_MEMSWAP, RES_LIMIT),
5908 .write = mem_cgroup_write,
5909 .read_u64 = mem_cgroup_read_u64,
5912 .name = "memsw.failcnt",
5913 .private = MEMFILE_PRIVATE(_MEMSWAP, RES_FAILCNT),
5914 .write = mem_cgroup_reset,
5915 .read_u64 = mem_cgroup_read_u64,
5917 { }, /* terminate */
5920 static int __init mem_cgroup_swap_init(void)
5922 if (!mem_cgroup_disabled() && really_do_swap_account) {
5923 do_swap_account = 1;
5924 WARN_ON(cgroup_add_dfl_cftypes(&memory_cgrp_subsys,
5926 WARN_ON(cgroup_add_legacy_cftypes(&memory_cgrp_subsys,
5927 memsw_cgroup_files));
5931 subsys_initcall(mem_cgroup_swap_init);
5933 #endif /* CONFIG_MEMCG_SWAP */