1 /* memcontrol.c - Memory Controller
3 * Copyright IBM Corporation, 2007
4 * Author Balbir Singh <balbir@linux.vnet.ibm.com>
6 * Copyright 2007 OpenVZ SWsoft Inc
7 * Author: Pavel Emelianov <xemul@openvz.org>
10 * Copyright (C) 2009 Nokia Corporation
11 * Author: Kirill A. Shutemov
13 * Kernel Memory Controller
14 * Copyright (C) 2012 Parallels Inc. and Google Inc.
15 * Authors: Glauber Costa and Suleiman Souhlal
18 * Charge lifetime sanitation
19 * Lockless page tracking & accounting
20 * Unified hierarchy configuration model
21 * Copyright (C) 2015 Red Hat, Inc., Johannes Weiner
23 * This program is free software; you can redistribute it and/or modify
24 * it under the terms of the GNU General Public License as published by
25 * the Free Software Foundation; either version 2 of the License, or
26 * (at your option) any later version.
28 * This program is distributed in the hope that it will be useful,
29 * but WITHOUT ANY WARRANTY; without even the implied warranty of
30 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
31 * GNU General Public License for more details.
34 #include <linux/page_counter.h>
35 #include <linux/memcontrol.h>
36 #include <linux/cgroup.h>
38 #include <linux/hugetlb.h>
39 #include <linux/pagemap.h>
40 #include <linux/smp.h>
41 #include <linux/page-flags.h>
42 #include <linux/backing-dev.h>
43 #include <linux/bit_spinlock.h>
44 #include <linux/rcupdate.h>
45 #include <linux/limits.h>
46 #include <linux/export.h>
47 #include <linux/mutex.h>
48 #include <linux/rbtree.h>
49 #include <linux/slab.h>
50 #include <linux/swap.h>
51 #include <linux/swapops.h>
52 #include <linux/spinlock.h>
53 #include <linux/eventfd.h>
54 #include <linux/poll.h>
55 #include <linux/sort.h>
57 #include <linux/seq_file.h>
58 #include <linux/vmpressure.h>
59 #include <linux/mm_inline.h>
60 #include <linux/swap_cgroup.h>
61 #include <linux/cpu.h>
62 #include <linux/oom.h>
63 #include <linux/lockdep.h>
64 #include <linux/file.h>
65 #include <linux/tracehook.h>
69 #include <net/tcp_memcontrol.h>
72 #include <asm/uaccess.h>
74 #include <trace/events/vmscan.h>
76 struct cgroup_subsys memory_cgrp_subsys __read_mostly
;
77 EXPORT_SYMBOL(memory_cgrp_subsys
);
79 #define MEM_CGROUP_RECLAIM_RETRIES 5
80 static struct mem_cgroup
*root_mem_cgroup __read_mostly
;
81 struct cgroup_subsys_state
*mem_cgroup_root_css __read_mostly
;
83 /* Whether the swap controller is active */
84 #ifdef CONFIG_MEMCG_SWAP
85 int do_swap_account __read_mostly
;
87 #define do_swap_account 0
90 static const char * const mem_cgroup_stat_names
[] = {
100 static const char * const mem_cgroup_events_names
[] = {
107 static const char * const mem_cgroup_lru_names
[] = {
115 #define THRESHOLDS_EVENTS_TARGET 128
116 #define SOFTLIMIT_EVENTS_TARGET 1024
117 #define NUMAINFO_EVENTS_TARGET 1024
120 * Cgroups above their limits are maintained in a RB-Tree, independent of
121 * their hierarchy representation
124 struct mem_cgroup_tree_per_zone
{
125 struct rb_root rb_root
;
129 struct mem_cgroup_tree_per_node
{
130 struct mem_cgroup_tree_per_zone rb_tree_per_zone
[MAX_NR_ZONES
];
133 struct mem_cgroup_tree
{
134 struct mem_cgroup_tree_per_node
*rb_tree_per_node
[MAX_NUMNODES
];
137 static struct mem_cgroup_tree soft_limit_tree __read_mostly
;
140 struct mem_cgroup_eventfd_list
{
141 struct list_head list
;
142 struct eventfd_ctx
*eventfd
;
146 * cgroup_event represents events which userspace want to receive.
148 struct mem_cgroup_event
{
150 * memcg which the event belongs to.
152 struct mem_cgroup
*memcg
;
154 * eventfd to signal userspace about the event.
156 struct eventfd_ctx
*eventfd
;
158 * Each of these stored in a list by the cgroup.
160 struct list_head list
;
162 * register_event() callback will be used to add new userspace
163 * waiter for changes related to this event. Use eventfd_signal()
164 * on eventfd to send notification to userspace.
166 int (*register_event
)(struct mem_cgroup
*memcg
,
167 struct eventfd_ctx
*eventfd
, const char *args
);
169 * unregister_event() callback will be called when userspace closes
170 * the eventfd or on cgroup removing. This callback must be set,
171 * if you want provide notification functionality.
173 void (*unregister_event
)(struct mem_cgroup
*memcg
,
174 struct eventfd_ctx
*eventfd
);
176 * All fields below needed to unregister event when
177 * userspace closes eventfd.
180 wait_queue_head_t
*wqh
;
182 struct work_struct remove
;
185 static void mem_cgroup_threshold(struct mem_cgroup
*memcg
);
186 static void mem_cgroup_oom_notify(struct mem_cgroup
*memcg
);
188 /* Stuffs for move charges at task migration. */
190 * Types of charges to be moved.
192 #define MOVE_ANON 0x1U
193 #define MOVE_FILE 0x2U
194 #define MOVE_MASK (MOVE_ANON | MOVE_FILE)
196 /* "mc" and its members are protected by cgroup_mutex */
197 static struct move_charge_struct
{
198 spinlock_t lock
; /* for from, to */
199 struct mem_cgroup
*from
;
200 struct mem_cgroup
*to
;
202 unsigned long precharge
;
203 unsigned long moved_charge
;
204 unsigned long moved_swap
;
205 struct task_struct
*moving_task
; /* a task moving charges */
206 wait_queue_head_t waitq
; /* a waitq for other context */
208 .lock
= __SPIN_LOCK_UNLOCKED(mc
.lock
),
209 .waitq
= __WAIT_QUEUE_HEAD_INITIALIZER(mc
.waitq
),
213 * Maximum loops in mem_cgroup_hierarchical_reclaim(), used for soft
214 * limit reclaim to prevent infinite loops, if they ever occur.
216 #define MEM_CGROUP_MAX_RECLAIM_LOOPS 100
217 #define MEM_CGROUP_MAX_SOFT_LIMIT_RECLAIM_LOOPS 2
220 MEM_CGROUP_CHARGE_TYPE_CACHE
= 0,
221 MEM_CGROUP_CHARGE_TYPE_ANON
,
222 MEM_CGROUP_CHARGE_TYPE_SWAPOUT
, /* for accounting swapcache */
223 MEM_CGROUP_CHARGE_TYPE_DROP
, /* a page was unused swap cache */
227 /* for encoding cft->private value on file */
235 #define MEMFILE_PRIVATE(x, val) ((x) << 16 | (val))
236 #define MEMFILE_TYPE(val) ((val) >> 16 & 0xffff)
237 #define MEMFILE_ATTR(val) ((val) & 0xffff)
238 /* Used for OOM nofiier */
239 #define OOM_CONTROL (0)
242 * The memcg_create_mutex will be held whenever a new cgroup is created.
243 * As a consequence, any change that needs to protect against new child cgroups
244 * appearing has to hold it as well.
246 static DEFINE_MUTEX(memcg_create_mutex
);
248 /* Some nice accessors for the vmpressure. */
249 struct vmpressure
*memcg_to_vmpressure(struct mem_cgroup
*memcg
)
252 memcg
= root_mem_cgroup
;
253 return &memcg
->vmpressure
;
256 struct cgroup_subsys_state
*vmpressure_to_css(struct vmpressure
*vmpr
)
258 return &container_of(vmpr
, struct mem_cgroup
, vmpressure
)->css
;
261 static inline bool mem_cgroup_is_root(struct mem_cgroup
*memcg
)
263 return (memcg
== root_mem_cgroup
);
267 * We restrict the id in the range of [1, 65535], so it can fit into
270 #define MEM_CGROUP_ID_MAX USHRT_MAX
272 static inline unsigned short mem_cgroup_id(struct mem_cgroup
*memcg
)
274 return memcg
->css
.id
;
278 * A helper function to get mem_cgroup from ID. must be called under
279 * rcu_read_lock(). The caller is responsible for calling
280 * css_tryget_online() if the mem_cgroup is used for charging. (dropping
281 * refcnt from swap can be called against removed memcg.)
283 static inline struct mem_cgroup
*mem_cgroup_from_id(unsigned short id
)
285 struct cgroup_subsys_state
*css
;
287 css
= css_from_id(id
, &memory_cgrp_subsys
);
288 return mem_cgroup_from_css(css
);
291 /* Writing them here to avoid exposing memcg's inner layout */
292 #if defined(CONFIG_INET) && defined(CONFIG_MEMCG_KMEM)
294 void sock_update_memcg(struct sock
*sk
)
296 if (mem_cgroup_sockets_enabled
) {
297 struct mem_cgroup
*memcg
;
298 struct cg_proto
*cg_proto
;
300 BUG_ON(!sk
->sk_prot
->proto_cgroup
);
302 /* Socket cloning can throw us here with sk_cgrp already
303 * filled. It won't however, necessarily happen from
304 * process context. So the test for root memcg given
305 * the current task's memcg won't help us in this case.
307 * Respecting the original socket's memcg is a better
308 * decision in this case.
311 BUG_ON(mem_cgroup_is_root(sk
->sk_cgrp
->memcg
));
312 css_get(&sk
->sk_cgrp
->memcg
->css
);
317 memcg
= mem_cgroup_from_task(current
);
318 cg_proto
= sk
->sk_prot
->proto_cgroup(memcg
);
319 if (cg_proto
&& test_bit(MEMCG_SOCK_ACTIVE
, &cg_proto
->flags
) &&
320 css_tryget_online(&memcg
->css
)) {
321 sk
->sk_cgrp
= cg_proto
;
326 EXPORT_SYMBOL(sock_update_memcg
);
328 void sock_release_memcg(struct sock
*sk
)
330 if (mem_cgroup_sockets_enabled
&& sk
->sk_cgrp
) {
331 struct mem_cgroup
*memcg
;
332 WARN_ON(!sk
->sk_cgrp
->memcg
);
333 memcg
= sk
->sk_cgrp
->memcg
;
334 css_put(&sk
->sk_cgrp
->memcg
->css
);
338 struct cg_proto
*tcp_proto_cgroup(struct mem_cgroup
*memcg
)
340 if (!memcg
|| mem_cgroup_is_root(memcg
))
343 return &memcg
->tcp_mem
;
345 EXPORT_SYMBOL(tcp_proto_cgroup
);
349 #ifdef CONFIG_MEMCG_KMEM
351 * This will be the memcg's index in each cache's ->memcg_params.memcg_caches.
352 * The main reason for not using cgroup id for this:
353 * this works better in sparse environments, where we have a lot of memcgs,
354 * but only a few kmem-limited. Or also, if we have, for instance, 200
355 * memcgs, and none but the 200th is kmem-limited, we'd have to have a
356 * 200 entry array for that.
358 * The current size of the caches array is stored in memcg_nr_cache_ids. It
359 * will double each time we have to increase it.
361 static DEFINE_IDA(memcg_cache_ida
);
362 int memcg_nr_cache_ids
;
364 /* Protects memcg_nr_cache_ids */
365 static DECLARE_RWSEM(memcg_cache_ids_sem
);
367 void memcg_get_cache_ids(void)
369 down_read(&memcg_cache_ids_sem
);
372 void memcg_put_cache_ids(void)
374 up_read(&memcg_cache_ids_sem
);
378 * MIN_SIZE is different than 1, because we would like to avoid going through
379 * the alloc/free process all the time. In a small machine, 4 kmem-limited
380 * cgroups is a reasonable guess. In the future, it could be a parameter or
381 * tunable, but that is strictly not necessary.
383 * MAX_SIZE should be as large as the number of cgrp_ids. Ideally, we could get
384 * this constant directly from cgroup, but it is understandable that this is
385 * better kept as an internal representation in cgroup.c. In any case, the
386 * cgrp_id space is not getting any smaller, and we don't have to necessarily
387 * increase ours as well if it increases.
389 #define MEMCG_CACHES_MIN_SIZE 4
390 #define MEMCG_CACHES_MAX_SIZE MEM_CGROUP_ID_MAX
393 * A lot of the calls to the cache allocation functions are expected to be
394 * inlined by the compiler. Since the calls to memcg_kmem_get_cache are
395 * conditional to this static branch, we'll have to allow modules that does
396 * kmem_cache_alloc and the such to see this symbol as well
398 struct static_key memcg_kmem_enabled_key
;
399 EXPORT_SYMBOL(memcg_kmem_enabled_key
);
401 #endif /* CONFIG_MEMCG_KMEM */
403 static struct mem_cgroup_per_zone
*
404 mem_cgroup_zone_zoneinfo(struct mem_cgroup
*memcg
, struct zone
*zone
)
406 int nid
= zone_to_nid(zone
);
407 int zid
= zone_idx(zone
);
409 return &memcg
->nodeinfo
[nid
]->zoneinfo
[zid
];
413 * mem_cgroup_css_from_page - css of the memcg associated with a page
414 * @page: page of interest
416 * If memcg is bound to the default hierarchy, css of the memcg associated
417 * with @page is returned. The returned css remains associated with @page
418 * until it is released.
420 * If memcg is bound to a traditional hierarchy, the css of root_mem_cgroup
423 * XXX: The above description of behavior on the default hierarchy isn't
424 * strictly true yet as replace_page_cache_page() can modify the
425 * association before @page is released even on the default hierarchy;
426 * however, the current and planned usages don't mix the the two functions
427 * and replace_page_cache_page() will soon be updated to make the invariant
430 struct cgroup_subsys_state
*mem_cgroup_css_from_page(struct page
*page
)
432 struct mem_cgroup
*memcg
;
436 memcg
= page
->mem_cgroup
;
438 if (!memcg
|| !cgroup_on_dfl(memcg
->css
.cgroup
))
439 memcg
= root_mem_cgroup
;
446 * page_cgroup_ino - return inode number of the memcg a page is charged to
449 * Look up the closest online ancestor of the memory cgroup @page is charged to
450 * and return its inode number or 0 if @page is not charged to any cgroup. It
451 * is safe to call this function without holding a reference to @page.
453 * Note, this function is inherently racy, because there is nothing to prevent
454 * the cgroup inode from getting torn down and potentially reallocated a moment
455 * after page_cgroup_ino() returns, so it only should be used by callers that
456 * do not care (such as procfs interfaces).
458 ino_t
page_cgroup_ino(struct page
*page
)
460 struct mem_cgroup
*memcg
;
461 unsigned long ino
= 0;
464 memcg
= READ_ONCE(page
->mem_cgroup
);
465 while (memcg
&& !(memcg
->css
.flags
& CSS_ONLINE
))
466 memcg
= parent_mem_cgroup(memcg
);
468 ino
= cgroup_ino(memcg
->css
.cgroup
);
473 static struct mem_cgroup_per_zone
*
474 mem_cgroup_page_zoneinfo(struct mem_cgroup
*memcg
, struct page
*page
)
476 int nid
= page_to_nid(page
);
477 int zid
= page_zonenum(page
);
479 return &memcg
->nodeinfo
[nid
]->zoneinfo
[zid
];
482 static struct mem_cgroup_tree_per_zone
*
483 soft_limit_tree_node_zone(int nid
, int zid
)
485 return &soft_limit_tree
.rb_tree_per_node
[nid
]->rb_tree_per_zone
[zid
];
488 static struct mem_cgroup_tree_per_zone
*
489 soft_limit_tree_from_page(struct page
*page
)
491 int nid
= page_to_nid(page
);
492 int zid
= page_zonenum(page
);
494 return &soft_limit_tree
.rb_tree_per_node
[nid
]->rb_tree_per_zone
[zid
];
497 static void __mem_cgroup_insert_exceeded(struct mem_cgroup_per_zone
*mz
,
498 struct mem_cgroup_tree_per_zone
*mctz
,
499 unsigned long new_usage_in_excess
)
501 struct rb_node
**p
= &mctz
->rb_root
.rb_node
;
502 struct rb_node
*parent
= NULL
;
503 struct mem_cgroup_per_zone
*mz_node
;
508 mz
->usage_in_excess
= new_usage_in_excess
;
509 if (!mz
->usage_in_excess
)
513 mz_node
= rb_entry(parent
, struct mem_cgroup_per_zone
,
515 if (mz
->usage_in_excess
< mz_node
->usage_in_excess
)
518 * We can't avoid mem cgroups that are over their soft
519 * limit by the same amount
521 else if (mz
->usage_in_excess
>= mz_node
->usage_in_excess
)
524 rb_link_node(&mz
->tree_node
, parent
, p
);
525 rb_insert_color(&mz
->tree_node
, &mctz
->rb_root
);
529 static void __mem_cgroup_remove_exceeded(struct mem_cgroup_per_zone
*mz
,
530 struct mem_cgroup_tree_per_zone
*mctz
)
534 rb_erase(&mz
->tree_node
, &mctz
->rb_root
);
538 static void mem_cgroup_remove_exceeded(struct mem_cgroup_per_zone
*mz
,
539 struct mem_cgroup_tree_per_zone
*mctz
)
543 spin_lock_irqsave(&mctz
->lock
, flags
);
544 __mem_cgroup_remove_exceeded(mz
, mctz
);
545 spin_unlock_irqrestore(&mctz
->lock
, flags
);
548 static unsigned long soft_limit_excess(struct mem_cgroup
*memcg
)
550 unsigned long nr_pages
= page_counter_read(&memcg
->memory
);
551 unsigned long soft_limit
= READ_ONCE(memcg
->soft_limit
);
552 unsigned long excess
= 0;
554 if (nr_pages
> soft_limit
)
555 excess
= nr_pages
- soft_limit
;
560 static void mem_cgroup_update_tree(struct mem_cgroup
*memcg
, struct page
*page
)
562 unsigned long excess
;
563 struct mem_cgroup_per_zone
*mz
;
564 struct mem_cgroup_tree_per_zone
*mctz
;
566 mctz
= soft_limit_tree_from_page(page
);
568 * Necessary to update all ancestors when hierarchy is used.
569 * because their event counter is not touched.
571 for (; memcg
; memcg
= parent_mem_cgroup(memcg
)) {
572 mz
= mem_cgroup_page_zoneinfo(memcg
, page
);
573 excess
= soft_limit_excess(memcg
);
575 * We have to update the tree if mz is on RB-tree or
576 * mem is over its softlimit.
578 if (excess
|| mz
->on_tree
) {
581 spin_lock_irqsave(&mctz
->lock
, flags
);
582 /* if on-tree, remove it */
584 __mem_cgroup_remove_exceeded(mz
, mctz
);
586 * Insert again. mz->usage_in_excess will be updated.
587 * If excess is 0, no tree ops.
589 __mem_cgroup_insert_exceeded(mz
, mctz
, excess
);
590 spin_unlock_irqrestore(&mctz
->lock
, flags
);
595 static void mem_cgroup_remove_from_trees(struct mem_cgroup
*memcg
)
597 struct mem_cgroup_tree_per_zone
*mctz
;
598 struct mem_cgroup_per_zone
*mz
;
602 for (zid
= 0; zid
< MAX_NR_ZONES
; zid
++) {
603 mz
= &memcg
->nodeinfo
[nid
]->zoneinfo
[zid
];
604 mctz
= soft_limit_tree_node_zone(nid
, zid
);
605 mem_cgroup_remove_exceeded(mz
, mctz
);
610 static struct mem_cgroup_per_zone
*
611 __mem_cgroup_largest_soft_limit_node(struct mem_cgroup_tree_per_zone
*mctz
)
613 struct rb_node
*rightmost
= NULL
;
614 struct mem_cgroup_per_zone
*mz
;
618 rightmost
= rb_last(&mctz
->rb_root
);
620 goto done
; /* Nothing to reclaim from */
622 mz
= rb_entry(rightmost
, struct mem_cgroup_per_zone
, tree_node
);
624 * Remove the node now but someone else can add it back,
625 * we will to add it back at the end of reclaim to its correct
626 * position in the tree.
628 __mem_cgroup_remove_exceeded(mz
, mctz
);
629 if (!soft_limit_excess(mz
->memcg
) ||
630 !css_tryget_online(&mz
->memcg
->css
))
636 static struct mem_cgroup_per_zone
*
637 mem_cgroup_largest_soft_limit_node(struct mem_cgroup_tree_per_zone
*mctz
)
639 struct mem_cgroup_per_zone
*mz
;
641 spin_lock_irq(&mctz
->lock
);
642 mz
= __mem_cgroup_largest_soft_limit_node(mctz
);
643 spin_unlock_irq(&mctz
->lock
);
648 * Return page count for single (non recursive) @memcg.
650 * Implementation Note: reading percpu statistics for memcg.
652 * Both of vmstat[] and percpu_counter has threshold and do periodic
653 * synchronization to implement "quick" read. There are trade-off between
654 * reading cost and precision of value. Then, we may have a chance to implement
655 * a periodic synchronization of counter in memcg's counter.
657 * But this _read() function is used for user interface now. The user accounts
658 * memory usage by memory cgroup and he _always_ requires exact value because
659 * he accounts memory. Even if we provide quick-and-fuzzy read, we always
660 * have to visit all online cpus and make sum. So, for now, unnecessary
661 * synchronization is not implemented. (just implemented for cpu hotplug)
663 * If there are kernel internal actions which can make use of some not-exact
664 * value, and reading all cpu value can be performance bottleneck in some
665 * common workload, threshold and synchronization as vmstat[] should be
669 mem_cgroup_read_stat(struct mem_cgroup
*memcg
, enum mem_cgroup_stat_index idx
)
674 /* Per-cpu values can be negative, use a signed accumulator */
675 for_each_possible_cpu(cpu
)
676 val
+= per_cpu(memcg
->stat
->count
[idx
], cpu
);
678 * Summing races with updates, so val may be negative. Avoid exposing
679 * transient negative values.
686 static unsigned long mem_cgroup_read_events(struct mem_cgroup
*memcg
,
687 enum mem_cgroup_events_index idx
)
689 unsigned long val
= 0;
692 for_each_possible_cpu(cpu
)
693 val
+= per_cpu(memcg
->stat
->events
[idx
], cpu
);
697 static void mem_cgroup_charge_statistics(struct mem_cgroup
*memcg
,
702 * Here, RSS means 'mapped anon' and anon's SwapCache. Shmem/tmpfs is
703 * counted as CACHE even if it's on ANON LRU.
706 __this_cpu_add(memcg
->stat
->count
[MEM_CGROUP_STAT_RSS
],
709 __this_cpu_add(memcg
->stat
->count
[MEM_CGROUP_STAT_CACHE
],
712 if (PageTransHuge(page
))
713 __this_cpu_add(memcg
->stat
->count
[MEM_CGROUP_STAT_RSS_HUGE
],
716 /* pagein of a big page is an event. So, ignore page size */
718 __this_cpu_inc(memcg
->stat
->events
[MEM_CGROUP_EVENTS_PGPGIN
]);
720 __this_cpu_inc(memcg
->stat
->events
[MEM_CGROUP_EVENTS_PGPGOUT
]);
721 nr_pages
= -nr_pages
; /* for event */
724 __this_cpu_add(memcg
->stat
->nr_page_events
, nr_pages
);
727 static unsigned long mem_cgroup_node_nr_lru_pages(struct mem_cgroup
*memcg
,
729 unsigned int lru_mask
)
731 unsigned long nr
= 0;
734 VM_BUG_ON((unsigned)nid
>= nr_node_ids
);
736 for (zid
= 0; zid
< MAX_NR_ZONES
; zid
++) {
737 struct mem_cgroup_per_zone
*mz
;
741 if (!(BIT(lru
) & lru_mask
))
743 mz
= &memcg
->nodeinfo
[nid
]->zoneinfo
[zid
];
744 nr
+= mz
->lru_size
[lru
];
750 static unsigned long mem_cgroup_nr_lru_pages(struct mem_cgroup
*memcg
,
751 unsigned int lru_mask
)
753 unsigned long nr
= 0;
756 for_each_node_state(nid
, N_MEMORY
)
757 nr
+= mem_cgroup_node_nr_lru_pages(memcg
, nid
, lru_mask
);
761 static bool mem_cgroup_event_ratelimit(struct mem_cgroup
*memcg
,
762 enum mem_cgroup_events_target target
)
764 unsigned long val
, next
;
766 val
= __this_cpu_read(memcg
->stat
->nr_page_events
);
767 next
= __this_cpu_read(memcg
->stat
->targets
[target
]);
768 /* from time_after() in jiffies.h */
769 if ((long)next
- (long)val
< 0) {
771 case MEM_CGROUP_TARGET_THRESH
:
772 next
= val
+ THRESHOLDS_EVENTS_TARGET
;
774 case MEM_CGROUP_TARGET_SOFTLIMIT
:
775 next
= val
+ SOFTLIMIT_EVENTS_TARGET
;
777 case MEM_CGROUP_TARGET_NUMAINFO
:
778 next
= val
+ NUMAINFO_EVENTS_TARGET
;
783 __this_cpu_write(memcg
->stat
->targets
[target
], next
);
790 * Check events in order.
793 static void memcg_check_events(struct mem_cgroup
*memcg
, struct page
*page
)
795 /* threshold event is triggered in finer grain than soft limit */
796 if (unlikely(mem_cgroup_event_ratelimit(memcg
,
797 MEM_CGROUP_TARGET_THRESH
))) {
799 bool do_numainfo __maybe_unused
;
801 do_softlimit
= mem_cgroup_event_ratelimit(memcg
,
802 MEM_CGROUP_TARGET_SOFTLIMIT
);
804 do_numainfo
= mem_cgroup_event_ratelimit(memcg
,
805 MEM_CGROUP_TARGET_NUMAINFO
);
807 mem_cgroup_threshold(memcg
);
808 if (unlikely(do_softlimit
))
809 mem_cgroup_update_tree(memcg
, page
);
811 if (unlikely(do_numainfo
))
812 atomic_inc(&memcg
->numainfo_events
);
817 struct mem_cgroup
*mem_cgroup_from_task(struct task_struct
*p
)
820 * mm_update_next_owner() may clear mm->owner to NULL
821 * if it races with swapoff, page migration, etc.
822 * So this can be called with p == NULL.
827 return mem_cgroup_from_css(task_css(p
, memory_cgrp_id
));
829 EXPORT_SYMBOL(mem_cgroup_from_task
);
831 static struct mem_cgroup
*get_mem_cgroup_from_mm(struct mm_struct
*mm
)
833 struct mem_cgroup
*memcg
= NULL
;
838 * Page cache insertions can happen withou an
839 * actual mm context, e.g. during disk probing
840 * on boot, loopback IO, acct() writes etc.
843 memcg
= root_mem_cgroup
;
845 memcg
= mem_cgroup_from_task(rcu_dereference(mm
->owner
));
846 if (unlikely(!memcg
))
847 memcg
= root_mem_cgroup
;
849 } while (!css_tryget_online(&memcg
->css
));
855 * mem_cgroup_iter - iterate over memory cgroup hierarchy
856 * @root: hierarchy root
857 * @prev: previously returned memcg, NULL on first invocation
858 * @reclaim: cookie for shared reclaim walks, NULL for full walks
860 * Returns references to children of the hierarchy below @root, or
861 * @root itself, or %NULL after a full round-trip.
863 * Caller must pass the return value in @prev on subsequent
864 * invocations for reference counting, or use mem_cgroup_iter_break()
865 * to cancel a hierarchy walk before the round-trip is complete.
867 * Reclaimers can specify a zone and a priority level in @reclaim to
868 * divide up the memcgs in the hierarchy among all concurrent
869 * reclaimers operating on the same zone and priority.
871 struct mem_cgroup
*mem_cgroup_iter(struct mem_cgroup
*root
,
872 struct mem_cgroup
*prev
,
873 struct mem_cgroup_reclaim_cookie
*reclaim
)
875 struct mem_cgroup_reclaim_iter
*uninitialized_var(iter
);
876 struct cgroup_subsys_state
*css
= NULL
;
877 struct mem_cgroup
*memcg
= NULL
;
878 struct mem_cgroup
*pos
= NULL
;
880 if (mem_cgroup_disabled())
884 root
= root_mem_cgroup
;
886 if (prev
&& !reclaim
)
889 if (!root
->use_hierarchy
&& root
!= root_mem_cgroup
) {
898 struct mem_cgroup_per_zone
*mz
;
900 mz
= mem_cgroup_zone_zoneinfo(root
, reclaim
->zone
);
901 iter
= &mz
->iter
[reclaim
->priority
];
903 if (prev
&& reclaim
->generation
!= iter
->generation
)
907 pos
= READ_ONCE(iter
->position
);
909 * A racing update may change the position and
910 * put the last reference, hence css_tryget(),
911 * or retry to see the updated position.
913 } while (pos
&& !css_tryget(&pos
->css
));
920 css
= css_next_descendant_pre(css
, &root
->css
);
923 * Reclaimers share the hierarchy walk, and a
924 * new one might jump in right at the end of
925 * the hierarchy - make sure they see at least
926 * one group and restart from the beginning.
934 * Verify the css and acquire a reference. The root
935 * is provided by the caller, so we know it's alive
936 * and kicking, and don't take an extra reference.
938 memcg
= mem_cgroup_from_css(css
);
940 if (css
== &root
->css
)
943 if (css_tryget(css
)) {
945 * Make sure the memcg is initialized:
946 * mem_cgroup_css_online() orders the the
947 * initialization against setting the flag.
949 if (smp_load_acquire(&memcg
->initialized
))
959 if (cmpxchg(&iter
->position
, pos
, memcg
) == pos
) {
961 css_get(&memcg
->css
);
967 * pairs with css_tryget when dereferencing iter->position
976 reclaim
->generation
= iter
->generation
;
982 if (prev
&& prev
!= root
)
989 * mem_cgroup_iter_break - abort a hierarchy walk prematurely
990 * @root: hierarchy root
991 * @prev: last visited hierarchy member as returned by mem_cgroup_iter()
993 void mem_cgroup_iter_break(struct mem_cgroup
*root
,
994 struct mem_cgroup
*prev
)
997 root
= root_mem_cgroup
;
998 if (prev
&& prev
!= root
)
1003 * Iteration constructs for visiting all cgroups (under a tree). If
1004 * loops are exited prematurely (break), mem_cgroup_iter_break() must
1005 * be used for reference counting.
1007 #define for_each_mem_cgroup_tree(iter, root) \
1008 for (iter = mem_cgroup_iter(root, NULL, NULL); \
1010 iter = mem_cgroup_iter(root, iter, NULL))
1012 #define for_each_mem_cgroup(iter) \
1013 for (iter = mem_cgroup_iter(NULL, NULL, NULL); \
1015 iter = mem_cgroup_iter(NULL, iter, NULL))
1018 * mem_cgroup_zone_lruvec - get the lru list vector for a zone and memcg
1019 * @zone: zone of the wanted lruvec
1020 * @memcg: memcg of the wanted lruvec
1022 * Returns the lru list vector holding pages for the given @zone and
1023 * @mem. This can be the global zone lruvec, if the memory controller
1026 struct lruvec
*mem_cgroup_zone_lruvec(struct zone
*zone
,
1027 struct mem_cgroup
*memcg
)
1029 struct mem_cgroup_per_zone
*mz
;
1030 struct lruvec
*lruvec
;
1032 if (mem_cgroup_disabled()) {
1033 lruvec
= &zone
->lruvec
;
1037 mz
= mem_cgroup_zone_zoneinfo(memcg
, zone
);
1038 lruvec
= &mz
->lruvec
;
1041 * Since a node can be onlined after the mem_cgroup was created,
1042 * we have to be prepared to initialize lruvec->zone here;
1043 * and if offlined then reonlined, we need to reinitialize it.
1045 if (unlikely(lruvec
->zone
!= zone
))
1046 lruvec
->zone
= zone
;
1051 * mem_cgroup_page_lruvec - return lruvec for isolating/putting an LRU page
1053 * @zone: zone of the page
1055 * This function is only safe when following the LRU page isolation
1056 * and putback protocol: the LRU lock must be held, and the page must
1057 * either be PageLRU() or the caller must have isolated/allocated it.
1059 struct lruvec
*mem_cgroup_page_lruvec(struct page
*page
, struct zone
*zone
)
1061 struct mem_cgroup_per_zone
*mz
;
1062 struct mem_cgroup
*memcg
;
1063 struct lruvec
*lruvec
;
1065 if (mem_cgroup_disabled()) {
1066 lruvec
= &zone
->lruvec
;
1070 memcg
= page
->mem_cgroup
;
1072 * Swapcache readahead pages are added to the LRU - and
1073 * possibly migrated - before they are charged.
1076 memcg
= root_mem_cgroup
;
1078 mz
= mem_cgroup_page_zoneinfo(memcg
, page
);
1079 lruvec
= &mz
->lruvec
;
1082 * Since a node can be onlined after the mem_cgroup was created,
1083 * we have to be prepared to initialize lruvec->zone here;
1084 * and if offlined then reonlined, we need to reinitialize it.
1086 if (unlikely(lruvec
->zone
!= zone
))
1087 lruvec
->zone
= zone
;
1092 * mem_cgroup_update_lru_size - account for adding or removing an lru page
1093 * @lruvec: mem_cgroup per zone lru vector
1094 * @lru: index of lru list the page is sitting on
1095 * @nr_pages: positive when adding or negative when removing
1097 * This function must be called when a page is added to or removed from an
1100 void mem_cgroup_update_lru_size(struct lruvec
*lruvec
, enum lru_list lru
,
1103 struct mem_cgroup_per_zone
*mz
;
1104 unsigned long *lru_size
;
1106 if (mem_cgroup_disabled())
1109 mz
= container_of(lruvec
, struct mem_cgroup_per_zone
, lruvec
);
1110 lru_size
= mz
->lru_size
+ lru
;
1111 *lru_size
+= nr_pages
;
1112 VM_BUG_ON((long)(*lru_size
) < 0);
1115 bool task_in_mem_cgroup(struct task_struct
*task
, struct mem_cgroup
*memcg
)
1117 struct mem_cgroup
*task_memcg
;
1118 struct task_struct
*p
;
1121 p
= find_lock_task_mm(task
);
1123 task_memcg
= get_mem_cgroup_from_mm(p
->mm
);
1127 * All threads may have already detached their mm's, but the oom
1128 * killer still needs to detect if they have already been oom
1129 * killed to prevent needlessly killing additional tasks.
1132 task_memcg
= mem_cgroup_from_task(task
);
1133 css_get(&task_memcg
->css
);
1136 ret
= mem_cgroup_is_descendant(task_memcg
, memcg
);
1137 css_put(&task_memcg
->css
);
1141 #define mem_cgroup_from_counter(counter, member) \
1142 container_of(counter, struct mem_cgroup, member)
1145 * mem_cgroup_margin - calculate chargeable space of a memory cgroup
1146 * @memcg: the memory cgroup
1148 * Returns the maximum amount of memory @mem can be charged with, in
1151 static unsigned long mem_cgroup_margin(struct mem_cgroup
*memcg
)
1153 unsigned long margin
= 0;
1154 unsigned long count
;
1155 unsigned long limit
;
1157 count
= page_counter_read(&memcg
->memory
);
1158 limit
= READ_ONCE(memcg
->memory
.limit
);
1160 margin
= limit
- count
;
1162 if (do_swap_account
) {
1163 count
= page_counter_read(&memcg
->memsw
);
1164 limit
= READ_ONCE(memcg
->memsw
.limit
);
1166 margin
= min(margin
, limit
- count
);
1173 * A routine for checking "mem" is under move_account() or not.
1175 * Checking a cgroup is mc.from or mc.to or under hierarchy of
1176 * moving cgroups. This is for waiting at high-memory pressure
1179 static bool mem_cgroup_under_move(struct mem_cgroup
*memcg
)
1181 struct mem_cgroup
*from
;
1182 struct mem_cgroup
*to
;
1185 * Unlike task_move routines, we access mc.to, mc.from not under
1186 * mutual exclusion by cgroup_mutex. Here, we take spinlock instead.
1188 spin_lock(&mc
.lock
);
1194 ret
= mem_cgroup_is_descendant(from
, memcg
) ||
1195 mem_cgroup_is_descendant(to
, memcg
);
1197 spin_unlock(&mc
.lock
);
1201 static bool mem_cgroup_wait_acct_move(struct mem_cgroup
*memcg
)
1203 if (mc
.moving_task
&& current
!= mc
.moving_task
) {
1204 if (mem_cgroup_under_move(memcg
)) {
1206 prepare_to_wait(&mc
.waitq
, &wait
, TASK_INTERRUPTIBLE
);
1207 /* moving charge context might have finished. */
1210 finish_wait(&mc
.waitq
, &wait
);
1217 #define K(x) ((x) << (PAGE_SHIFT-10))
1219 * mem_cgroup_print_oom_info: Print OOM information relevant to memory controller.
1220 * @memcg: The memory cgroup that went over limit
1221 * @p: Task that is going to be killed
1223 * NOTE: @memcg and @p's mem_cgroup can be different when hierarchy is
1226 void mem_cgroup_print_oom_info(struct mem_cgroup
*memcg
, struct task_struct
*p
)
1228 /* oom_info_lock ensures that parallel ooms do not interleave */
1229 static DEFINE_MUTEX(oom_info_lock
);
1230 struct mem_cgroup
*iter
;
1233 mutex_lock(&oom_info_lock
);
1237 pr_info("Task in ");
1238 pr_cont_cgroup_path(task_cgroup(p
, memory_cgrp_id
));
1239 pr_cont(" killed as a result of limit of ");
1241 pr_info("Memory limit reached of cgroup ");
1244 pr_cont_cgroup_path(memcg
->css
.cgroup
);
1249 pr_info("memory: usage %llukB, limit %llukB, failcnt %lu\n",
1250 K((u64
)page_counter_read(&memcg
->memory
)),
1251 K((u64
)memcg
->memory
.limit
), memcg
->memory
.failcnt
);
1252 pr_info("memory+swap: usage %llukB, limit %llukB, failcnt %lu\n",
1253 K((u64
)page_counter_read(&memcg
->memsw
)),
1254 K((u64
)memcg
->memsw
.limit
), memcg
->memsw
.failcnt
);
1255 pr_info("kmem: usage %llukB, limit %llukB, failcnt %lu\n",
1256 K((u64
)page_counter_read(&memcg
->kmem
)),
1257 K((u64
)memcg
->kmem
.limit
), memcg
->kmem
.failcnt
);
1259 for_each_mem_cgroup_tree(iter
, memcg
) {
1260 pr_info("Memory cgroup stats for ");
1261 pr_cont_cgroup_path(iter
->css
.cgroup
);
1264 for (i
= 0; i
< MEM_CGROUP_STAT_NSTATS
; i
++) {
1265 if (i
== MEM_CGROUP_STAT_SWAP
&& !do_swap_account
)
1267 pr_cont(" %s:%luKB", mem_cgroup_stat_names
[i
],
1268 K(mem_cgroup_read_stat(iter
, i
)));
1271 for (i
= 0; i
< NR_LRU_LISTS
; i
++)
1272 pr_cont(" %s:%luKB", mem_cgroup_lru_names
[i
],
1273 K(mem_cgroup_nr_lru_pages(iter
, BIT(i
))));
1277 mutex_unlock(&oom_info_lock
);
1281 * This function returns the number of memcg under hierarchy tree. Returns
1282 * 1(self count) if no children.
1284 static int mem_cgroup_count_children(struct mem_cgroup
*memcg
)
1287 struct mem_cgroup
*iter
;
1289 for_each_mem_cgroup_tree(iter
, memcg
)
1295 * Return the memory (and swap, if configured) limit for a memcg.
1297 static unsigned long mem_cgroup_get_limit(struct mem_cgroup
*memcg
)
1299 unsigned long limit
;
1301 limit
= memcg
->memory
.limit
;
1302 if (mem_cgroup_swappiness(memcg
)) {
1303 unsigned long memsw_limit
;
1305 memsw_limit
= memcg
->memsw
.limit
;
1306 limit
= min(limit
+ total_swap_pages
, memsw_limit
);
1311 static void mem_cgroup_out_of_memory(struct mem_cgroup
*memcg
, gfp_t gfp_mask
,
1314 struct oom_control oc
= {
1317 .gfp_mask
= gfp_mask
,
1320 struct mem_cgroup
*iter
;
1321 unsigned long chosen_points
= 0;
1322 unsigned long totalpages
;
1323 unsigned int points
= 0;
1324 struct task_struct
*chosen
= NULL
;
1326 mutex_lock(&oom_lock
);
1329 * If current has a pending SIGKILL or is exiting, then automatically
1330 * select it. The goal is to allow it to allocate so that it may
1331 * quickly exit and free its memory.
1333 if (fatal_signal_pending(current
) || task_will_free_mem(current
)) {
1334 mark_oom_victim(current
);
1338 check_panic_on_oom(&oc
, CONSTRAINT_MEMCG
, memcg
);
1339 totalpages
= mem_cgroup_get_limit(memcg
) ? : 1;
1340 for_each_mem_cgroup_tree(iter
, memcg
) {
1341 struct css_task_iter it
;
1342 struct task_struct
*task
;
1344 css_task_iter_start(&iter
->css
, &it
);
1345 while ((task
= css_task_iter_next(&it
))) {
1346 switch (oom_scan_process_thread(&oc
, task
, totalpages
)) {
1347 case OOM_SCAN_SELECT
:
1349 put_task_struct(chosen
);
1351 chosen_points
= ULONG_MAX
;
1352 get_task_struct(chosen
);
1354 case OOM_SCAN_CONTINUE
:
1356 case OOM_SCAN_ABORT
:
1357 css_task_iter_end(&it
);
1358 mem_cgroup_iter_break(memcg
, iter
);
1360 put_task_struct(chosen
);
1365 points
= oom_badness(task
, memcg
, NULL
, totalpages
);
1366 if (!points
|| points
< chosen_points
)
1368 /* Prefer thread group leaders for display purposes */
1369 if (points
== chosen_points
&&
1370 thread_group_leader(chosen
))
1374 put_task_struct(chosen
);
1376 chosen_points
= points
;
1377 get_task_struct(chosen
);
1379 css_task_iter_end(&it
);
1383 points
= chosen_points
* 1000 / totalpages
;
1384 oom_kill_process(&oc
, chosen
, points
, totalpages
, memcg
,
1385 "Memory cgroup out of memory");
1388 mutex_unlock(&oom_lock
);
1391 #if MAX_NUMNODES > 1
1394 * test_mem_cgroup_node_reclaimable
1395 * @memcg: the target memcg
1396 * @nid: the node ID to be checked.
1397 * @noswap : specify true here if the user wants flle only information.
1399 * This function returns whether the specified memcg contains any
1400 * reclaimable pages on a node. Returns true if there are any reclaimable
1401 * pages in the node.
1403 static bool test_mem_cgroup_node_reclaimable(struct mem_cgroup
*memcg
,
1404 int nid
, bool noswap
)
1406 if (mem_cgroup_node_nr_lru_pages(memcg
, nid
, LRU_ALL_FILE
))
1408 if (noswap
|| !total_swap_pages
)
1410 if (mem_cgroup_node_nr_lru_pages(memcg
, nid
, LRU_ALL_ANON
))
1417 * Always updating the nodemask is not very good - even if we have an empty
1418 * list or the wrong list here, we can start from some node and traverse all
1419 * nodes based on the zonelist. So update the list loosely once per 10 secs.
1422 static void mem_cgroup_may_update_nodemask(struct mem_cgroup
*memcg
)
1426 * numainfo_events > 0 means there was at least NUMAINFO_EVENTS_TARGET
1427 * pagein/pageout changes since the last update.
1429 if (!atomic_read(&memcg
->numainfo_events
))
1431 if (atomic_inc_return(&memcg
->numainfo_updating
) > 1)
1434 /* make a nodemask where this memcg uses memory from */
1435 memcg
->scan_nodes
= node_states
[N_MEMORY
];
1437 for_each_node_mask(nid
, node_states
[N_MEMORY
]) {
1439 if (!test_mem_cgroup_node_reclaimable(memcg
, nid
, false))
1440 node_clear(nid
, memcg
->scan_nodes
);
1443 atomic_set(&memcg
->numainfo_events
, 0);
1444 atomic_set(&memcg
->numainfo_updating
, 0);
1448 * Selecting a node where we start reclaim from. Because what we need is just
1449 * reducing usage counter, start from anywhere is O,K. Considering
1450 * memory reclaim from current node, there are pros. and cons.
1452 * Freeing memory from current node means freeing memory from a node which
1453 * we'll use or we've used. So, it may make LRU bad. And if several threads
1454 * hit limits, it will see a contention on a node. But freeing from remote
1455 * node means more costs for memory reclaim because of memory latency.
1457 * Now, we use round-robin. Better algorithm is welcomed.
1459 int mem_cgroup_select_victim_node(struct mem_cgroup
*memcg
)
1463 mem_cgroup_may_update_nodemask(memcg
);
1464 node
= memcg
->last_scanned_node
;
1466 node
= next_node(node
, memcg
->scan_nodes
);
1467 if (node
== MAX_NUMNODES
)
1468 node
= first_node(memcg
->scan_nodes
);
1470 * We call this when we hit limit, not when pages are added to LRU.
1471 * No LRU may hold pages because all pages are UNEVICTABLE or
1472 * memcg is too small and all pages are not on LRU. In that case,
1473 * we use curret node.
1475 if (unlikely(node
== MAX_NUMNODES
))
1476 node
= numa_node_id();
1478 memcg
->last_scanned_node
= node
;
1482 int mem_cgroup_select_victim_node(struct mem_cgroup
*memcg
)
1488 static int mem_cgroup_soft_reclaim(struct mem_cgroup
*root_memcg
,
1491 unsigned long *total_scanned
)
1493 struct mem_cgroup
*victim
= NULL
;
1496 unsigned long excess
;
1497 unsigned long nr_scanned
;
1498 struct mem_cgroup_reclaim_cookie reclaim
= {
1503 excess
= soft_limit_excess(root_memcg
);
1506 victim
= mem_cgroup_iter(root_memcg
, victim
, &reclaim
);
1511 * If we have not been able to reclaim
1512 * anything, it might because there are
1513 * no reclaimable pages under this hierarchy
1518 * We want to do more targeted reclaim.
1519 * excess >> 2 is not to excessive so as to
1520 * reclaim too much, nor too less that we keep
1521 * coming back to reclaim from this cgroup
1523 if (total
>= (excess
>> 2) ||
1524 (loop
> MEM_CGROUP_MAX_RECLAIM_LOOPS
))
1529 total
+= mem_cgroup_shrink_node_zone(victim
, gfp_mask
, false,
1531 *total_scanned
+= nr_scanned
;
1532 if (!soft_limit_excess(root_memcg
))
1535 mem_cgroup_iter_break(root_memcg
, victim
);
1539 #ifdef CONFIG_LOCKDEP
1540 static struct lockdep_map memcg_oom_lock_dep_map
= {
1541 .name
= "memcg_oom_lock",
1545 static DEFINE_SPINLOCK(memcg_oom_lock
);
1548 * Check OOM-Killer is already running under our hierarchy.
1549 * If someone is running, return false.
1551 static bool mem_cgroup_oom_trylock(struct mem_cgroup
*memcg
)
1553 struct mem_cgroup
*iter
, *failed
= NULL
;
1555 spin_lock(&memcg_oom_lock
);
1557 for_each_mem_cgroup_tree(iter
, memcg
) {
1558 if (iter
->oom_lock
) {
1560 * this subtree of our hierarchy is already locked
1561 * so we cannot give a lock.
1564 mem_cgroup_iter_break(memcg
, iter
);
1567 iter
->oom_lock
= true;
1572 * OK, we failed to lock the whole subtree so we have
1573 * to clean up what we set up to the failing subtree
1575 for_each_mem_cgroup_tree(iter
, memcg
) {
1576 if (iter
== failed
) {
1577 mem_cgroup_iter_break(memcg
, iter
);
1580 iter
->oom_lock
= false;
1583 mutex_acquire(&memcg_oom_lock_dep_map
, 0, 1, _RET_IP_
);
1585 spin_unlock(&memcg_oom_lock
);
1590 static void mem_cgroup_oom_unlock(struct mem_cgroup
*memcg
)
1592 struct mem_cgroup
*iter
;
1594 spin_lock(&memcg_oom_lock
);
1595 mutex_release(&memcg_oom_lock_dep_map
, 1, _RET_IP_
);
1596 for_each_mem_cgroup_tree(iter
, memcg
)
1597 iter
->oom_lock
= false;
1598 spin_unlock(&memcg_oom_lock
);
1601 static void mem_cgroup_mark_under_oom(struct mem_cgroup
*memcg
)
1603 struct mem_cgroup
*iter
;
1605 spin_lock(&memcg_oom_lock
);
1606 for_each_mem_cgroup_tree(iter
, memcg
)
1608 spin_unlock(&memcg_oom_lock
);
1611 static void mem_cgroup_unmark_under_oom(struct mem_cgroup
*memcg
)
1613 struct mem_cgroup
*iter
;
1616 * When a new child is created while the hierarchy is under oom,
1617 * mem_cgroup_oom_lock() may not be called. Watch for underflow.
1619 spin_lock(&memcg_oom_lock
);
1620 for_each_mem_cgroup_tree(iter
, memcg
)
1621 if (iter
->under_oom
> 0)
1623 spin_unlock(&memcg_oom_lock
);
1626 static DECLARE_WAIT_QUEUE_HEAD(memcg_oom_waitq
);
1628 struct oom_wait_info
{
1629 struct mem_cgroup
*memcg
;
1633 static int memcg_oom_wake_function(wait_queue_t
*wait
,
1634 unsigned mode
, int sync
, void *arg
)
1636 struct mem_cgroup
*wake_memcg
= (struct mem_cgroup
*)arg
;
1637 struct mem_cgroup
*oom_wait_memcg
;
1638 struct oom_wait_info
*oom_wait_info
;
1640 oom_wait_info
= container_of(wait
, struct oom_wait_info
, wait
);
1641 oom_wait_memcg
= oom_wait_info
->memcg
;
1643 if (!mem_cgroup_is_descendant(wake_memcg
, oom_wait_memcg
) &&
1644 !mem_cgroup_is_descendant(oom_wait_memcg
, wake_memcg
))
1646 return autoremove_wake_function(wait
, mode
, sync
, arg
);
1649 static void memcg_oom_recover(struct mem_cgroup
*memcg
)
1652 * For the following lockless ->under_oom test, the only required
1653 * guarantee is that it must see the state asserted by an OOM when
1654 * this function is called as a result of userland actions
1655 * triggered by the notification of the OOM. This is trivially
1656 * achieved by invoking mem_cgroup_mark_under_oom() before
1657 * triggering notification.
1659 if (memcg
&& memcg
->under_oom
)
1660 __wake_up(&memcg_oom_waitq
, TASK_NORMAL
, 0, memcg
);
1663 static void mem_cgroup_oom(struct mem_cgroup
*memcg
, gfp_t mask
, int order
)
1665 if (!current
->memcg_may_oom
)
1668 * We are in the middle of the charge context here, so we
1669 * don't want to block when potentially sitting on a callstack
1670 * that holds all kinds of filesystem and mm locks.
1672 * Also, the caller may handle a failed allocation gracefully
1673 * (like optional page cache readahead) and so an OOM killer
1674 * invocation might not even be necessary.
1676 * That's why we don't do anything here except remember the
1677 * OOM context and then deal with it at the end of the page
1678 * fault when the stack is unwound, the locks are released,
1679 * and when we know whether the fault was overall successful.
1681 css_get(&memcg
->css
);
1682 current
->memcg_in_oom
= memcg
;
1683 current
->memcg_oom_gfp_mask
= mask
;
1684 current
->memcg_oom_order
= order
;
1688 * mem_cgroup_oom_synchronize - complete memcg OOM handling
1689 * @handle: actually kill/wait or just clean up the OOM state
1691 * This has to be called at the end of a page fault if the memcg OOM
1692 * handler was enabled.
1694 * Memcg supports userspace OOM handling where failed allocations must
1695 * sleep on a waitqueue until the userspace task resolves the
1696 * situation. Sleeping directly in the charge context with all kinds
1697 * of locks held is not a good idea, instead we remember an OOM state
1698 * in the task and mem_cgroup_oom_synchronize() has to be called at
1699 * the end of the page fault to complete the OOM handling.
1701 * Returns %true if an ongoing memcg OOM situation was detected and
1702 * completed, %false otherwise.
1704 bool mem_cgroup_oom_synchronize(bool handle
)
1706 struct mem_cgroup
*memcg
= current
->memcg_in_oom
;
1707 struct oom_wait_info owait
;
1710 /* OOM is global, do not handle */
1714 if (!handle
|| oom_killer_disabled
)
1717 owait
.memcg
= memcg
;
1718 owait
.wait
.flags
= 0;
1719 owait
.wait
.func
= memcg_oom_wake_function
;
1720 owait
.wait
.private = current
;
1721 INIT_LIST_HEAD(&owait
.wait
.task_list
);
1723 prepare_to_wait(&memcg_oom_waitq
, &owait
.wait
, TASK_KILLABLE
);
1724 mem_cgroup_mark_under_oom(memcg
);
1726 locked
= mem_cgroup_oom_trylock(memcg
);
1729 mem_cgroup_oom_notify(memcg
);
1731 if (locked
&& !memcg
->oom_kill_disable
) {
1732 mem_cgroup_unmark_under_oom(memcg
);
1733 finish_wait(&memcg_oom_waitq
, &owait
.wait
);
1734 mem_cgroup_out_of_memory(memcg
, current
->memcg_oom_gfp_mask
,
1735 current
->memcg_oom_order
);
1738 mem_cgroup_unmark_under_oom(memcg
);
1739 finish_wait(&memcg_oom_waitq
, &owait
.wait
);
1743 mem_cgroup_oom_unlock(memcg
);
1745 * There is no guarantee that an OOM-lock contender
1746 * sees the wakeups triggered by the OOM kill
1747 * uncharges. Wake any sleepers explicitely.
1749 memcg_oom_recover(memcg
);
1752 current
->memcg_in_oom
= NULL
;
1753 css_put(&memcg
->css
);
1758 * mem_cgroup_begin_page_stat - begin a page state statistics transaction
1759 * @page: page that is going to change accounted state
1761 * This function must mark the beginning of an accounted page state
1762 * change to prevent double accounting when the page is concurrently
1763 * being moved to another memcg:
1765 * memcg = mem_cgroup_begin_page_stat(page);
1766 * if (TestClearPageState(page))
1767 * mem_cgroup_update_page_stat(memcg, state, -1);
1768 * mem_cgroup_end_page_stat(memcg);
1770 struct mem_cgroup
*mem_cgroup_begin_page_stat(struct page
*page
)
1772 struct mem_cgroup
*memcg
;
1773 unsigned long flags
;
1776 * The RCU lock is held throughout the transaction. The fast
1777 * path can get away without acquiring the memcg->move_lock
1778 * because page moving starts with an RCU grace period.
1780 * The RCU lock also protects the memcg from being freed when
1781 * the page state that is going to change is the only thing
1782 * preventing the page from being uncharged.
1783 * E.g. end-writeback clearing PageWriteback(), which allows
1784 * migration to go ahead and uncharge the page before the
1785 * account transaction might be complete.
1789 if (mem_cgroup_disabled())
1792 memcg
= page
->mem_cgroup
;
1793 if (unlikely(!memcg
))
1796 if (atomic_read(&memcg
->moving_account
) <= 0)
1799 spin_lock_irqsave(&memcg
->move_lock
, flags
);
1800 if (memcg
!= page
->mem_cgroup
) {
1801 spin_unlock_irqrestore(&memcg
->move_lock
, flags
);
1806 * When charge migration first begins, we can have locked and
1807 * unlocked page stat updates happening concurrently. Track
1808 * the task who has the lock for mem_cgroup_end_page_stat().
1810 memcg
->move_lock_task
= current
;
1811 memcg
->move_lock_flags
= flags
;
1815 EXPORT_SYMBOL(mem_cgroup_begin_page_stat
);
1818 * mem_cgroup_end_page_stat - finish a page state statistics transaction
1819 * @memcg: the memcg that was accounted against
1821 void mem_cgroup_end_page_stat(struct mem_cgroup
*memcg
)
1823 if (memcg
&& memcg
->move_lock_task
== current
) {
1824 unsigned long flags
= memcg
->move_lock_flags
;
1826 memcg
->move_lock_task
= NULL
;
1827 memcg
->move_lock_flags
= 0;
1829 spin_unlock_irqrestore(&memcg
->move_lock
, flags
);
1834 EXPORT_SYMBOL(mem_cgroup_end_page_stat
);
1837 * size of first charge trial. "32" comes from vmscan.c's magic value.
1838 * TODO: maybe necessary to use big numbers in big irons.
1840 #define CHARGE_BATCH 32U
1841 struct memcg_stock_pcp
{
1842 struct mem_cgroup
*cached
; /* this never be root cgroup */
1843 unsigned int nr_pages
;
1844 struct work_struct work
;
1845 unsigned long flags
;
1846 #define FLUSHING_CACHED_CHARGE 0
1848 static DEFINE_PER_CPU(struct memcg_stock_pcp
, memcg_stock
);
1849 static DEFINE_MUTEX(percpu_charge_mutex
);
1852 * consume_stock: Try to consume stocked charge on this cpu.
1853 * @memcg: memcg to consume from.
1854 * @nr_pages: how many pages to charge.
1856 * The charges will only happen if @memcg matches the current cpu's memcg
1857 * stock, and at least @nr_pages are available in that stock. Failure to
1858 * service an allocation will refill the stock.
1860 * returns true if successful, false otherwise.
1862 static bool consume_stock(struct mem_cgroup
*memcg
, unsigned int nr_pages
)
1864 struct memcg_stock_pcp
*stock
;
1867 if (nr_pages
> CHARGE_BATCH
)
1870 stock
= &get_cpu_var(memcg_stock
);
1871 if (memcg
== stock
->cached
&& stock
->nr_pages
>= nr_pages
) {
1872 stock
->nr_pages
-= nr_pages
;
1875 put_cpu_var(memcg_stock
);
1880 * Returns stocks cached in percpu and reset cached information.
1882 static void drain_stock(struct memcg_stock_pcp
*stock
)
1884 struct mem_cgroup
*old
= stock
->cached
;
1886 if (stock
->nr_pages
) {
1887 page_counter_uncharge(&old
->memory
, stock
->nr_pages
);
1888 if (do_swap_account
)
1889 page_counter_uncharge(&old
->memsw
, stock
->nr_pages
);
1890 css_put_many(&old
->css
, stock
->nr_pages
);
1891 stock
->nr_pages
= 0;
1893 stock
->cached
= NULL
;
1897 * This must be called under preempt disabled or must be called by
1898 * a thread which is pinned to local cpu.
1900 static void drain_local_stock(struct work_struct
*dummy
)
1902 struct memcg_stock_pcp
*stock
= this_cpu_ptr(&memcg_stock
);
1904 clear_bit(FLUSHING_CACHED_CHARGE
, &stock
->flags
);
1908 * Cache charges(val) to local per_cpu area.
1909 * This will be consumed by consume_stock() function, later.
1911 static void refill_stock(struct mem_cgroup
*memcg
, unsigned int nr_pages
)
1913 struct memcg_stock_pcp
*stock
= &get_cpu_var(memcg_stock
);
1915 if (stock
->cached
!= memcg
) { /* reset if necessary */
1917 stock
->cached
= memcg
;
1919 stock
->nr_pages
+= nr_pages
;
1920 put_cpu_var(memcg_stock
);
1924 * Drains all per-CPU charge caches for given root_memcg resp. subtree
1925 * of the hierarchy under it.
1927 static void drain_all_stock(struct mem_cgroup
*root_memcg
)
1931 /* If someone's already draining, avoid adding running more workers. */
1932 if (!mutex_trylock(&percpu_charge_mutex
))
1934 /* Notify other cpus that system-wide "drain" is running */
1937 for_each_online_cpu(cpu
) {
1938 struct memcg_stock_pcp
*stock
= &per_cpu(memcg_stock
, cpu
);
1939 struct mem_cgroup
*memcg
;
1941 memcg
= stock
->cached
;
1942 if (!memcg
|| !stock
->nr_pages
)
1944 if (!mem_cgroup_is_descendant(memcg
, root_memcg
))
1946 if (!test_and_set_bit(FLUSHING_CACHED_CHARGE
, &stock
->flags
)) {
1948 drain_local_stock(&stock
->work
);
1950 schedule_work_on(cpu
, &stock
->work
);
1955 mutex_unlock(&percpu_charge_mutex
);
1958 static int memcg_cpu_hotplug_callback(struct notifier_block
*nb
,
1959 unsigned long action
,
1962 int cpu
= (unsigned long)hcpu
;
1963 struct memcg_stock_pcp
*stock
;
1965 if (action
== CPU_ONLINE
)
1968 if (action
!= CPU_DEAD
&& action
!= CPU_DEAD_FROZEN
)
1971 stock
= &per_cpu(memcg_stock
, cpu
);
1977 * Scheduled by try_charge() to be executed from the userland return path
1978 * and reclaims memory over the high limit.
1980 void mem_cgroup_handle_over_high(void)
1982 unsigned int nr_pages
= current
->memcg_nr_pages_over_high
;
1983 struct mem_cgroup
*memcg
, *pos
;
1985 if (likely(!nr_pages
))
1988 pos
= memcg
= get_mem_cgroup_from_mm(current
->mm
);
1991 if (page_counter_read(&pos
->memory
) <= pos
->high
)
1993 mem_cgroup_events(pos
, MEMCG_HIGH
, 1);
1994 try_to_free_mem_cgroup_pages(pos
, nr_pages
, GFP_KERNEL
, true);
1995 } while ((pos
= parent_mem_cgroup(pos
)));
1997 css_put(&memcg
->css
);
1998 current
->memcg_nr_pages_over_high
= 0;
2001 static int try_charge(struct mem_cgroup
*memcg
, gfp_t gfp_mask
,
2002 unsigned int nr_pages
)
2004 unsigned int batch
= max(CHARGE_BATCH
, nr_pages
);
2005 int nr_retries
= MEM_CGROUP_RECLAIM_RETRIES
;
2006 struct mem_cgroup
*mem_over_limit
;
2007 struct page_counter
*counter
;
2008 unsigned long nr_reclaimed
;
2009 bool may_swap
= true;
2010 bool drained
= false;
2012 if (mem_cgroup_is_root(memcg
))
2015 if (consume_stock(memcg
, nr_pages
))
2018 if (!do_swap_account
||
2019 !page_counter_try_charge(&memcg
->memsw
, batch
, &counter
)) {
2020 if (!page_counter_try_charge(&memcg
->memory
, batch
, &counter
))
2022 if (do_swap_account
)
2023 page_counter_uncharge(&memcg
->memsw
, batch
);
2024 mem_over_limit
= mem_cgroup_from_counter(counter
, memory
);
2026 mem_over_limit
= mem_cgroup_from_counter(counter
, memsw
);
2030 if (batch
> nr_pages
) {
2036 * Unlike in global OOM situations, memcg is not in a physical
2037 * memory shortage. Allow dying and OOM-killed tasks to
2038 * bypass the last charges so that they can exit quickly and
2039 * free their memory.
2041 if (unlikely(test_thread_flag(TIF_MEMDIE
) ||
2042 fatal_signal_pending(current
) ||
2043 current
->flags
& PF_EXITING
))
2046 if (unlikely(task_in_memcg_oom(current
)))
2049 if (!(gfp_mask
& __GFP_WAIT
))
2052 mem_cgroup_events(mem_over_limit
, MEMCG_MAX
, 1);
2054 nr_reclaimed
= try_to_free_mem_cgroup_pages(mem_over_limit
, nr_pages
,
2055 gfp_mask
, may_swap
);
2057 if (mem_cgroup_margin(mem_over_limit
) >= nr_pages
)
2061 drain_all_stock(mem_over_limit
);
2066 if (gfp_mask
& __GFP_NORETRY
)
2069 * Even though the limit is exceeded at this point, reclaim
2070 * may have been able to free some pages. Retry the charge
2071 * before killing the task.
2073 * Only for regular pages, though: huge pages are rather
2074 * unlikely to succeed so close to the limit, and we fall back
2075 * to regular pages anyway in case of failure.
2077 if (nr_reclaimed
&& nr_pages
<= (1 << PAGE_ALLOC_COSTLY_ORDER
))
2080 * At task move, charge accounts can be doubly counted. So, it's
2081 * better to wait until the end of task_move if something is going on.
2083 if (mem_cgroup_wait_acct_move(mem_over_limit
))
2089 if (gfp_mask
& __GFP_NOFAIL
)
2092 if (fatal_signal_pending(current
))
2095 mem_cgroup_events(mem_over_limit
, MEMCG_OOM
, 1);
2097 mem_cgroup_oom(mem_over_limit
, gfp_mask
, get_order(nr_pages
));
2099 if (!(gfp_mask
& __GFP_NOFAIL
))
2103 * The allocation either can't fail or will lead to more memory
2104 * being freed very soon. Allow memory usage go over the limit
2105 * temporarily by force charging it.
2107 page_counter_charge(&memcg
->memory
, nr_pages
);
2108 if (do_swap_account
)
2109 page_counter_charge(&memcg
->memsw
, nr_pages
);
2110 css_get_many(&memcg
->css
, nr_pages
);
2115 css_get_many(&memcg
->css
, batch
);
2116 if (batch
> nr_pages
)
2117 refill_stock(memcg
, batch
- nr_pages
);
2120 * If the hierarchy is above the normal consumption range, schedule
2121 * reclaim on returning to userland. We can perform reclaim here
2122 * if __GFP_WAIT but let's always punt for simplicity and so that
2123 * GFP_KERNEL can consistently be used during reclaim. @memcg is
2124 * not recorded as it most likely matches current's and won't
2125 * change in the meantime. As high limit is checked again before
2126 * reclaim, the cost of mismatch is negligible.
2129 if (page_counter_read(&memcg
->memory
) > memcg
->high
) {
2130 current
->memcg_nr_pages_over_high
+= nr_pages
;
2131 set_notify_resume(current
);
2134 } while ((memcg
= parent_mem_cgroup(memcg
)));
2139 static void cancel_charge(struct mem_cgroup
*memcg
, unsigned int nr_pages
)
2141 if (mem_cgroup_is_root(memcg
))
2144 page_counter_uncharge(&memcg
->memory
, nr_pages
);
2145 if (do_swap_account
)
2146 page_counter_uncharge(&memcg
->memsw
, nr_pages
);
2148 css_put_many(&memcg
->css
, nr_pages
);
2151 static void lock_page_lru(struct page
*page
, int *isolated
)
2153 struct zone
*zone
= page_zone(page
);
2155 spin_lock_irq(&zone
->lru_lock
);
2156 if (PageLRU(page
)) {
2157 struct lruvec
*lruvec
;
2159 lruvec
= mem_cgroup_page_lruvec(page
, zone
);
2161 del_page_from_lru_list(page
, lruvec
, page_lru(page
));
2167 static void unlock_page_lru(struct page
*page
, int isolated
)
2169 struct zone
*zone
= page_zone(page
);
2172 struct lruvec
*lruvec
;
2174 lruvec
= mem_cgroup_page_lruvec(page
, zone
);
2175 VM_BUG_ON_PAGE(PageLRU(page
), page
);
2177 add_page_to_lru_list(page
, lruvec
, page_lru(page
));
2179 spin_unlock_irq(&zone
->lru_lock
);
2182 static void commit_charge(struct page
*page
, struct mem_cgroup
*memcg
,
2187 VM_BUG_ON_PAGE(page
->mem_cgroup
, page
);
2190 * In some cases, SwapCache and FUSE(splice_buf->radixtree), the page
2191 * may already be on some other mem_cgroup's LRU. Take care of it.
2194 lock_page_lru(page
, &isolated
);
2197 * Nobody should be changing or seriously looking at
2198 * page->mem_cgroup at this point:
2200 * - the page is uncharged
2202 * - the page is off-LRU
2204 * - an anonymous fault has exclusive page access, except for
2205 * a locked page table
2207 * - a page cache insertion, a swapin fault, or a migration
2208 * have the page locked
2210 page
->mem_cgroup
= memcg
;
2213 unlock_page_lru(page
, isolated
);
2216 #ifdef CONFIG_MEMCG_KMEM
2217 int memcg_charge_kmem(struct mem_cgroup
*memcg
, gfp_t gfp
,
2218 unsigned long nr_pages
)
2220 struct page_counter
*counter
;
2223 ret
= page_counter_try_charge(&memcg
->kmem
, nr_pages
, &counter
);
2227 ret
= try_charge(memcg
, gfp
, nr_pages
);
2229 page_counter_uncharge(&memcg
->kmem
, nr_pages
);
2234 void memcg_uncharge_kmem(struct mem_cgroup
*memcg
, unsigned long nr_pages
)
2236 page_counter_uncharge(&memcg
->memory
, nr_pages
);
2237 if (do_swap_account
)
2238 page_counter_uncharge(&memcg
->memsw
, nr_pages
);
2240 page_counter_uncharge(&memcg
->kmem
, nr_pages
);
2242 css_put_many(&memcg
->css
, nr_pages
);
2245 static int memcg_alloc_cache_id(void)
2250 id
= ida_simple_get(&memcg_cache_ida
,
2251 0, MEMCG_CACHES_MAX_SIZE
, GFP_KERNEL
);
2255 if (id
< memcg_nr_cache_ids
)
2259 * There's no space for the new id in memcg_caches arrays,
2260 * so we have to grow them.
2262 down_write(&memcg_cache_ids_sem
);
2264 size
= 2 * (id
+ 1);
2265 if (size
< MEMCG_CACHES_MIN_SIZE
)
2266 size
= MEMCG_CACHES_MIN_SIZE
;
2267 else if (size
> MEMCG_CACHES_MAX_SIZE
)
2268 size
= MEMCG_CACHES_MAX_SIZE
;
2270 err
= memcg_update_all_caches(size
);
2272 err
= memcg_update_all_list_lrus(size
);
2274 memcg_nr_cache_ids
= size
;
2276 up_write(&memcg_cache_ids_sem
);
2279 ida_simple_remove(&memcg_cache_ida
, id
);
2285 static void memcg_free_cache_id(int id
)
2287 ida_simple_remove(&memcg_cache_ida
, id
);
2290 struct memcg_kmem_cache_create_work
{
2291 struct mem_cgroup
*memcg
;
2292 struct kmem_cache
*cachep
;
2293 struct work_struct work
;
2296 static void memcg_kmem_cache_create_func(struct work_struct
*w
)
2298 struct memcg_kmem_cache_create_work
*cw
=
2299 container_of(w
, struct memcg_kmem_cache_create_work
, work
);
2300 struct mem_cgroup
*memcg
= cw
->memcg
;
2301 struct kmem_cache
*cachep
= cw
->cachep
;
2303 memcg_create_kmem_cache(memcg
, cachep
);
2305 css_put(&memcg
->css
);
2310 * Enqueue the creation of a per-memcg kmem_cache.
2312 static void __memcg_schedule_kmem_cache_create(struct mem_cgroup
*memcg
,
2313 struct kmem_cache
*cachep
)
2315 struct memcg_kmem_cache_create_work
*cw
;
2317 cw
= kmalloc(sizeof(*cw
), GFP_NOWAIT
);
2321 css_get(&memcg
->css
);
2324 cw
->cachep
= cachep
;
2325 INIT_WORK(&cw
->work
, memcg_kmem_cache_create_func
);
2327 schedule_work(&cw
->work
);
2330 static void memcg_schedule_kmem_cache_create(struct mem_cgroup
*memcg
,
2331 struct kmem_cache
*cachep
)
2334 * We need to stop accounting when we kmalloc, because if the
2335 * corresponding kmalloc cache is not yet created, the first allocation
2336 * in __memcg_schedule_kmem_cache_create will recurse.
2338 * However, it is better to enclose the whole function. Depending on
2339 * the debugging options enabled, INIT_WORK(), for instance, can
2340 * trigger an allocation. This too, will make us recurse. Because at
2341 * this point we can't allow ourselves back into memcg_kmem_get_cache,
2342 * the safest choice is to do it like this, wrapping the whole function.
2344 current
->memcg_kmem_skip_account
= 1;
2345 __memcg_schedule_kmem_cache_create(memcg
, cachep
);
2346 current
->memcg_kmem_skip_account
= 0;
2350 * Return the kmem_cache we're supposed to use for a slab allocation.
2351 * We try to use the current memcg's version of the cache.
2353 * If the cache does not exist yet, if we are the first user of it,
2354 * we either create it immediately, if possible, or create it asynchronously
2356 * In the latter case, we will let the current allocation go through with
2357 * the original cache.
2359 * Can't be called in interrupt context or from kernel threads.
2360 * This function needs to be called with rcu_read_lock() held.
2362 struct kmem_cache
*__memcg_kmem_get_cache(struct kmem_cache
*cachep
)
2364 struct mem_cgroup
*memcg
;
2365 struct kmem_cache
*memcg_cachep
;
2368 VM_BUG_ON(!is_root_cache(cachep
));
2370 if (current
->memcg_kmem_skip_account
)
2373 memcg
= get_mem_cgroup_from_mm(current
->mm
);
2374 kmemcg_id
= READ_ONCE(memcg
->kmemcg_id
);
2378 memcg_cachep
= cache_from_memcg_idx(cachep
, kmemcg_id
);
2379 if (likely(memcg_cachep
))
2380 return memcg_cachep
;
2383 * If we are in a safe context (can wait, and not in interrupt
2384 * context), we could be be predictable and return right away.
2385 * This would guarantee that the allocation being performed
2386 * already belongs in the new cache.
2388 * However, there are some clashes that can arrive from locking.
2389 * For instance, because we acquire the slab_mutex while doing
2390 * memcg_create_kmem_cache, this means no further allocation
2391 * could happen with the slab_mutex held. So it's better to
2394 memcg_schedule_kmem_cache_create(memcg
, cachep
);
2396 css_put(&memcg
->css
);
2400 void __memcg_kmem_put_cache(struct kmem_cache
*cachep
)
2402 if (!is_root_cache(cachep
))
2403 css_put(&cachep
->memcg_params
.memcg
->css
);
2407 * We need to verify if the allocation against current->mm->owner's memcg is
2408 * possible for the given order. But the page is not allocated yet, so we'll
2409 * need a further commit step to do the final arrangements.
2411 * It is possible for the task to switch cgroups in this mean time, so at
2412 * commit time, we can't rely on task conversion any longer. We'll then use
2413 * the handle argument to return to the caller which cgroup we should commit
2414 * against. We could also return the memcg directly and avoid the pointer
2415 * passing, but a boolean return value gives better semantics considering
2416 * the compiled-out case as well.
2418 * Returning true means the allocation is possible.
2421 __memcg_kmem_newpage_charge(gfp_t gfp
, struct mem_cgroup
**_memcg
, int order
)
2423 struct mem_cgroup
*memcg
;
2428 memcg
= get_mem_cgroup_from_mm(current
->mm
);
2430 if (!memcg_kmem_is_active(memcg
)) {
2431 css_put(&memcg
->css
);
2435 ret
= memcg_charge_kmem(memcg
, gfp
, 1 << order
);
2439 css_put(&memcg
->css
);
2443 void __memcg_kmem_commit_charge(struct page
*page
, struct mem_cgroup
*memcg
,
2446 VM_BUG_ON(mem_cgroup_is_root(memcg
));
2448 /* The page allocation failed. Revert */
2450 memcg_uncharge_kmem(memcg
, 1 << order
);
2453 page
->mem_cgroup
= memcg
;
2456 void __memcg_kmem_uncharge_pages(struct page
*page
, int order
)
2458 struct mem_cgroup
*memcg
= page
->mem_cgroup
;
2463 VM_BUG_ON_PAGE(mem_cgroup_is_root(memcg
), page
);
2465 memcg_uncharge_kmem(memcg
, 1 << order
);
2466 page
->mem_cgroup
= NULL
;
2469 struct mem_cgroup
*__mem_cgroup_from_kmem(void *ptr
)
2471 struct mem_cgroup
*memcg
= NULL
;
2472 struct kmem_cache
*cachep
;
2475 page
= virt_to_head_page(ptr
);
2476 if (PageSlab(page
)) {
2477 cachep
= page
->slab_cache
;
2478 if (!is_root_cache(cachep
))
2479 memcg
= cachep
->memcg_params
.memcg
;
2481 /* page allocated by alloc_kmem_pages */
2482 memcg
= page
->mem_cgroup
;
2486 #endif /* CONFIG_MEMCG_KMEM */
2488 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
2491 * Because tail pages are not marked as "used", set it. We're under
2492 * zone->lru_lock, 'splitting on pmd' and compound_lock.
2493 * charge/uncharge will be never happen and move_account() is done under
2494 * compound_lock(), so we don't have to take care of races.
2496 void mem_cgroup_split_huge_fixup(struct page
*head
)
2500 if (mem_cgroup_disabled())
2503 for (i
= 1; i
< HPAGE_PMD_NR
; i
++)
2504 head
[i
].mem_cgroup
= head
->mem_cgroup
;
2506 __this_cpu_sub(head
->mem_cgroup
->stat
->count
[MEM_CGROUP_STAT_RSS_HUGE
],
2509 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
2511 #ifdef CONFIG_MEMCG_SWAP
2512 static void mem_cgroup_swap_statistics(struct mem_cgroup
*memcg
,
2515 int val
= (charge
) ? 1 : -1;
2516 this_cpu_add(memcg
->stat
->count
[MEM_CGROUP_STAT_SWAP
], val
);
2520 * mem_cgroup_move_swap_account - move swap charge and swap_cgroup's record.
2521 * @entry: swap entry to be moved
2522 * @from: mem_cgroup which the entry is moved from
2523 * @to: mem_cgroup which the entry is moved to
2525 * It succeeds only when the swap_cgroup's record for this entry is the same
2526 * as the mem_cgroup's id of @from.
2528 * Returns 0 on success, -EINVAL on failure.
2530 * The caller must have charged to @to, IOW, called page_counter_charge() about
2531 * both res and memsw, and called css_get().
2533 static int mem_cgroup_move_swap_account(swp_entry_t entry
,
2534 struct mem_cgroup
*from
, struct mem_cgroup
*to
)
2536 unsigned short old_id
, new_id
;
2538 old_id
= mem_cgroup_id(from
);
2539 new_id
= mem_cgroup_id(to
);
2541 if (swap_cgroup_cmpxchg(entry
, old_id
, new_id
) == old_id
) {
2542 mem_cgroup_swap_statistics(from
, false);
2543 mem_cgroup_swap_statistics(to
, true);
2549 static inline int mem_cgroup_move_swap_account(swp_entry_t entry
,
2550 struct mem_cgroup
*from
, struct mem_cgroup
*to
)
2556 static DEFINE_MUTEX(memcg_limit_mutex
);
2558 static int mem_cgroup_resize_limit(struct mem_cgroup
*memcg
,
2559 unsigned long limit
)
2561 unsigned long curusage
;
2562 unsigned long oldusage
;
2563 bool enlarge
= false;
2568 * For keeping hierarchical_reclaim simple, how long we should retry
2569 * is depends on callers. We set our retry-count to be function
2570 * of # of children which we should visit in this loop.
2572 retry_count
= MEM_CGROUP_RECLAIM_RETRIES
*
2573 mem_cgroup_count_children(memcg
);
2575 oldusage
= page_counter_read(&memcg
->memory
);
2578 if (signal_pending(current
)) {
2583 mutex_lock(&memcg_limit_mutex
);
2584 if (limit
> memcg
->memsw
.limit
) {
2585 mutex_unlock(&memcg_limit_mutex
);
2589 if (limit
> memcg
->memory
.limit
)
2591 ret
= page_counter_limit(&memcg
->memory
, limit
);
2592 mutex_unlock(&memcg_limit_mutex
);
2597 try_to_free_mem_cgroup_pages(memcg
, 1, GFP_KERNEL
, true);
2599 curusage
= page_counter_read(&memcg
->memory
);
2600 /* Usage is reduced ? */
2601 if (curusage
>= oldusage
)
2604 oldusage
= curusage
;
2605 } while (retry_count
);
2607 if (!ret
&& enlarge
)
2608 memcg_oom_recover(memcg
);
2613 static int mem_cgroup_resize_memsw_limit(struct mem_cgroup
*memcg
,
2614 unsigned long limit
)
2616 unsigned long curusage
;
2617 unsigned long oldusage
;
2618 bool enlarge
= false;
2622 /* see mem_cgroup_resize_res_limit */
2623 retry_count
= MEM_CGROUP_RECLAIM_RETRIES
*
2624 mem_cgroup_count_children(memcg
);
2626 oldusage
= page_counter_read(&memcg
->memsw
);
2629 if (signal_pending(current
)) {
2634 mutex_lock(&memcg_limit_mutex
);
2635 if (limit
< memcg
->memory
.limit
) {
2636 mutex_unlock(&memcg_limit_mutex
);
2640 if (limit
> memcg
->memsw
.limit
)
2642 ret
= page_counter_limit(&memcg
->memsw
, limit
);
2643 mutex_unlock(&memcg_limit_mutex
);
2648 try_to_free_mem_cgroup_pages(memcg
, 1, GFP_KERNEL
, false);
2650 curusage
= page_counter_read(&memcg
->memsw
);
2651 /* Usage is reduced ? */
2652 if (curusage
>= oldusage
)
2655 oldusage
= curusage
;
2656 } while (retry_count
);
2658 if (!ret
&& enlarge
)
2659 memcg_oom_recover(memcg
);
2664 unsigned long mem_cgroup_soft_limit_reclaim(struct zone
*zone
, int order
,
2666 unsigned long *total_scanned
)
2668 unsigned long nr_reclaimed
= 0;
2669 struct mem_cgroup_per_zone
*mz
, *next_mz
= NULL
;
2670 unsigned long reclaimed
;
2672 struct mem_cgroup_tree_per_zone
*mctz
;
2673 unsigned long excess
;
2674 unsigned long nr_scanned
;
2679 mctz
= soft_limit_tree_node_zone(zone_to_nid(zone
), zone_idx(zone
));
2681 * This loop can run a while, specially if mem_cgroup's continuously
2682 * keep exceeding their soft limit and putting the system under
2689 mz
= mem_cgroup_largest_soft_limit_node(mctz
);
2694 reclaimed
= mem_cgroup_soft_reclaim(mz
->memcg
, zone
,
2695 gfp_mask
, &nr_scanned
);
2696 nr_reclaimed
+= reclaimed
;
2697 *total_scanned
+= nr_scanned
;
2698 spin_lock_irq(&mctz
->lock
);
2699 __mem_cgroup_remove_exceeded(mz
, mctz
);
2702 * If we failed to reclaim anything from this memory cgroup
2703 * it is time to move on to the next cgroup
2707 next_mz
= __mem_cgroup_largest_soft_limit_node(mctz
);
2709 excess
= soft_limit_excess(mz
->memcg
);
2711 * One school of thought says that we should not add
2712 * back the node to the tree if reclaim returns 0.
2713 * But our reclaim could return 0, simply because due
2714 * to priority we are exposing a smaller subset of
2715 * memory to reclaim from. Consider this as a longer
2718 /* If excess == 0, no tree ops */
2719 __mem_cgroup_insert_exceeded(mz
, mctz
, excess
);
2720 spin_unlock_irq(&mctz
->lock
);
2721 css_put(&mz
->memcg
->css
);
2724 * Could not reclaim anything and there are no more
2725 * mem cgroups to try or we seem to be looping without
2726 * reclaiming anything.
2728 if (!nr_reclaimed
&&
2730 loop
> MEM_CGROUP_MAX_SOFT_LIMIT_RECLAIM_LOOPS
))
2732 } while (!nr_reclaimed
);
2734 css_put(&next_mz
->memcg
->css
);
2735 return nr_reclaimed
;
2739 * Test whether @memcg has children, dead or alive. Note that this
2740 * function doesn't care whether @memcg has use_hierarchy enabled and
2741 * returns %true if there are child csses according to the cgroup
2742 * hierarchy. Testing use_hierarchy is the caller's responsiblity.
2744 static inline bool memcg_has_children(struct mem_cgroup
*memcg
)
2749 * The lock does not prevent addition or deletion of children, but
2750 * it prevents a new child from being initialized based on this
2751 * parent in css_online(), so it's enough to decide whether
2752 * hierarchically inherited attributes can still be changed or not.
2754 lockdep_assert_held(&memcg_create_mutex
);
2757 ret
= css_next_child(NULL
, &memcg
->css
);
2763 * Reclaims as many pages from the given memcg as possible and moves
2764 * the rest to the parent.
2766 * Caller is responsible for holding css reference for memcg.
2768 static int mem_cgroup_force_empty(struct mem_cgroup
*memcg
)
2770 int nr_retries
= MEM_CGROUP_RECLAIM_RETRIES
;
2772 /* we call try-to-free pages for make this cgroup empty */
2773 lru_add_drain_all();
2774 /* try to free all pages in this cgroup */
2775 while (nr_retries
&& page_counter_read(&memcg
->memory
)) {
2778 if (signal_pending(current
))
2781 progress
= try_to_free_mem_cgroup_pages(memcg
, 1,
2785 /* maybe some writeback is necessary */
2786 congestion_wait(BLK_RW_ASYNC
, HZ
/10);
2794 static ssize_t
mem_cgroup_force_empty_write(struct kernfs_open_file
*of
,
2795 char *buf
, size_t nbytes
,
2798 struct mem_cgroup
*memcg
= mem_cgroup_from_css(of_css(of
));
2800 if (mem_cgroup_is_root(memcg
))
2802 return mem_cgroup_force_empty(memcg
) ?: nbytes
;
2805 static u64
mem_cgroup_hierarchy_read(struct cgroup_subsys_state
*css
,
2808 return mem_cgroup_from_css(css
)->use_hierarchy
;
2811 static int mem_cgroup_hierarchy_write(struct cgroup_subsys_state
*css
,
2812 struct cftype
*cft
, u64 val
)
2815 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
2816 struct mem_cgroup
*parent_memcg
= mem_cgroup_from_css(memcg
->css
.parent
);
2818 mutex_lock(&memcg_create_mutex
);
2820 if (memcg
->use_hierarchy
== val
)
2824 * If parent's use_hierarchy is set, we can't make any modifications
2825 * in the child subtrees. If it is unset, then the change can
2826 * occur, provided the current cgroup has no children.
2828 * For the root cgroup, parent_mem is NULL, we allow value to be
2829 * set if there are no children.
2831 if ((!parent_memcg
|| !parent_memcg
->use_hierarchy
) &&
2832 (val
== 1 || val
== 0)) {
2833 if (!memcg_has_children(memcg
))
2834 memcg
->use_hierarchy
= val
;
2841 mutex_unlock(&memcg_create_mutex
);
2846 static unsigned long tree_stat(struct mem_cgroup
*memcg
,
2847 enum mem_cgroup_stat_index idx
)
2849 struct mem_cgroup
*iter
;
2850 unsigned long val
= 0;
2852 for_each_mem_cgroup_tree(iter
, memcg
)
2853 val
+= mem_cgroup_read_stat(iter
, idx
);
2858 static inline u64
mem_cgroup_usage(struct mem_cgroup
*memcg
, bool swap
)
2862 if (mem_cgroup_is_root(memcg
)) {
2863 val
= tree_stat(memcg
, MEM_CGROUP_STAT_CACHE
);
2864 val
+= tree_stat(memcg
, MEM_CGROUP_STAT_RSS
);
2866 val
+= tree_stat(memcg
, MEM_CGROUP_STAT_SWAP
);
2869 val
= page_counter_read(&memcg
->memory
);
2871 val
= page_counter_read(&memcg
->memsw
);
2873 return val
<< PAGE_SHIFT
;
2884 static u64
mem_cgroup_read_u64(struct cgroup_subsys_state
*css
,
2887 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
2888 struct page_counter
*counter
;
2890 switch (MEMFILE_TYPE(cft
->private)) {
2892 counter
= &memcg
->memory
;
2895 counter
= &memcg
->memsw
;
2898 counter
= &memcg
->kmem
;
2904 switch (MEMFILE_ATTR(cft
->private)) {
2906 if (counter
== &memcg
->memory
)
2907 return mem_cgroup_usage(memcg
, false);
2908 if (counter
== &memcg
->memsw
)
2909 return mem_cgroup_usage(memcg
, true);
2910 return (u64
)page_counter_read(counter
) * PAGE_SIZE
;
2912 return (u64
)counter
->limit
* PAGE_SIZE
;
2914 return (u64
)counter
->watermark
* PAGE_SIZE
;
2916 return counter
->failcnt
;
2917 case RES_SOFT_LIMIT
:
2918 return (u64
)memcg
->soft_limit
* PAGE_SIZE
;
2924 #ifdef CONFIG_MEMCG_KMEM
2925 static int memcg_activate_kmem(struct mem_cgroup
*memcg
,
2926 unsigned long nr_pages
)
2931 BUG_ON(memcg
->kmemcg_id
>= 0);
2932 BUG_ON(memcg
->kmem_acct_activated
);
2933 BUG_ON(memcg
->kmem_acct_active
);
2936 * For simplicity, we won't allow this to be disabled. It also can't
2937 * be changed if the cgroup has children already, or if tasks had
2940 * If tasks join before we set the limit, a person looking at
2941 * kmem.usage_in_bytes will have no way to determine when it took
2942 * place, which makes the value quite meaningless.
2944 * After it first became limited, changes in the value of the limit are
2945 * of course permitted.
2947 mutex_lock(&memcg_create_mutex
);
2948 if (cgroup_has_tasks(memcg
->css
.cgroup
) ||
2949 (memcg
->use_hierarchy
&& memcg_has_children(memcg
)))
2951 mutex_unlock(&memcg_create_mutex
);
2955 memcg_id
= memcg_alloc_cache_id();
2962 * We couldn't have accounted to this cgroup, because it hasn't got
2963 * activated yet, so this should succeed.
2965 err
= page_counter_limit(&memcg
->kmem
, nr_pages
);
2968 static_key_slow_inc(&memcg_kmem_enabled_key
);
2970 * A memory cgroup is considered kmem-active as soon as it gets
2971 * kmemcg_id. Setting the id after enabling static branching will
2972 * guarantee no one starts accounting before all call sites are
2975 memcg
->kmemcg_id
= memcg_id
;
2976 memcg
->kmem_acct_activated
= true;
2977 memcg
->kmem_acct_active
= true;
2982 static int memcg_update_kmem_limit(struct mem_cgroup
*memcg
,
2983 unsigned long limit
)
2987 mutex_lock(&memcg_limit_mutex
);
2988 if (!memcg_kmem_is_active(memcg
))
2989 ret
= memcg_activate_kmem(memcg
, limit
);
2991 ret
= page_counter_limit(&memcg
->kmem
, limit
);
2992 mutex_unlock(&memcg_limit_mutex
);
2996 static int memcg_propagate_kmem(struct mem_cgroup
*memcg
)
2999 struct mem_cgroup
*parent
= parent_mem_cgroup(memcg
);
3004 mutex_lock(&memcg_limit_mutex
);
3006 * If the parent cgroup is not kmem-active now, it cannot be activated
3007 * after this point, because it has at least one child already.
3009 if (memcg_kmem_is_active(parent
))
3010 ret
= memcg_activate_kmem(memcg
, PAGE_COUNTER_MAX
);
3011 mutex_unlock(&memcg_limit_mutex
);
3015 static int memcg_update_kmem_limit(struct mem_cgroup
*memcg
,
3016 unsigned long limit
)
3020 #endif /* CONFIG_MEMCG_KMEM */
3023 * The user of this function is...
3026 static ssize_t
mem_cgroup_write(struct kernfs_open_file
*of
,
3027 char *buf
, size_t nbytes
, loff_t off
)
3029 struct mem_cgroup
*memcg
= mem_cgroup_from_css(of_css(of
));
3030 unsigned long nr_pages
;
3033 buf
= strstrip(buf
);
3034 ret
= page_counter_memparse(buf
, "-1", &nr_pages
);
3038 switch (MEMFILE_ATTR(of_cft(of
)->private)) {
3040 if (mem_cgroup_is_root(memcg
)) { /* Can't set limit on root */
3044 switch (MEMFILE_TYPE(of_cft(of
)->private)) {
3046 ret
= mem_cgroup_resize_limit(memcg
, nr_pages
);
3049 ret
= mem_cgroup_resize_memsw_limit(memcg
, nr_pages
);
3052 ret
= memcg_update_kmem_limit(memcg
, nr_pages
);
3056 case RES_SOFT_LIMIT
:
3057 memcg
->soft_limit
= nr_pages
;
3061 return ret
?: nbytes
;
3064 static ssize_t
mem_cgroup_reset(struct kernfs_open_file
*of
, char *buf
,
3065 size_t nbytes
, loff_t off
)
3067 struct mem_cgroup
*memcg
= mem_cgroup_from_css(of_css(of
));
3068 struct page_counter
*counter
;
3070 switch (MEMFILE_TYPE(of_cft(of
)->private)) {
3072 counter
= &memcg
->memory
;
3075 counter
= &memcg
->memsw
;
3078 counter
= &memcg
->kmem
;
3084 switch (MEMFILE_ATTR(of_cft(of
)->private)) {
3086 page_counter_reset_watermark(counter
);
3089 counter
->failcnt
= 0;
3098 static u64
mem_cgroup_move_charge_read(struct cgroup_subsys_state
*css
,
3101 return mem_cgroup_from_css(css
)->move_charge_at_immigrate
;
3105 static int mem_cgroup_move_charge_write(struct cgroup_subsys_state
*css
,
3106 struct cftype
*cft
, u64 val
)
3108 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
3110 if (val
& ~MOVE_MASK
)
3114 * No kind of locking is needed in here, because ->can_attach() will
3115 * check this value once in the beginning of the process, and then carry
3116 * on with stale data. This means that changes to this value will only
3117 * affect task migrations starting after the change.
3119 memcg
->move_charge_at_immigrate
= val
;
3123 static int mem_cgroup_move_charge_write(struct cgroup_subsys_state
*css
,
3124 struct cftype
*cft
, u64 val
)
3131 static int memcg_numa_stat_show(struct seq_file
*m
, void *v
)
3135 unsigned int lru_mask
;
3138 static const struct numa_stat stats
[] = {
3139 { "total", LRU_ALL
},
3140 { "file", LRU_ALL_FILE
},
3141 { "anon", LRU_ALL_ANON
},
3142 { "unevictable", BIT(LRU_UNEVICTABLE
) },
3144 const struct numa_stat
*stat
;
3147 struct mem_cgroup
*memcg
= mem_cgroup_from_css(seq_css(m
));
3149 for (stat
= stats
; stat
< stats
+ ARRAY_SIZE(stats
); stat
++) {
3150 nr
= mem_cgroup_nr_lru_pages(memcg
, stat
->lru_mask
);
3151 seq_printf(m
, "%s=%lu", stat
->name
, nr
);
3152 for_each_node_state(nid
, N_MEMORY
) {
3153 nr
= mem_cgroup_node_nr_lru_pages(memcg
, nid
,
3155 seq_printf(m
, " N%d=%lu", nid
, nr
);
3160 for (stat
= stats
; stat
< stats
+ ARRAY_SIZE(stats
); stat
++) {
3161 struct mem_cgroup
*iter
;
3164 for_each_mem_cgroup_tree(iter
, memcg
)
3165 nr
+= mem_cgroup_nr_lru_pages(iter
, stat
->lru_mask
);
3166 seq_printf(m
, "hierarchical_%s=%lu", stat
->name
, nr
);
3167 for_each_node_state(nid
, N_MEMORY
) {
3169 for_each_mem_cgroup_tree(iter
, memcg
)
3170 nr
+= mem_cgroup_node_nr_lru_pages(
3171 iter
, nid
, stat
->lru_mask
);
3172 seq_printf(m
, " N%d=%lu", nid
, nr
);
3179 #endif /* CONFIG_NUMA */
3181 static int memcg_stat_show(struct seq_file
*m
, void *v
)
3183 struct mem_cgroup
*memcg
= mem_cgroup_from_css(seq_css(m
));
3184 unsigned long memory
, memsw
;
3185 struct mem_cgroup
*mi
;
3188 BUILD_BUG_ON(ARRAY_SIZE(mem_cgroup_stat_names
) !=
3189 MEM_CGROUP_STAT_NSTATS
);
3190 BUILD_BUG_ON(ARRAY_SIZE(mem_cgroup_events_names
) !=
3191 MEM_CGROUP_EVENTS_NSTATS
);
3192 BUILD_BUG_ON(ARRAY_SIZE(mem_cgroup_lru_names
) != NR_LRU_LISTS
);
3194 for (i
= 0; i
< MEM_CGROUP_STAT_NSTATS
; i
++) {
3195 if (i
== MEM_CGROUP_STAT_SWAP
&& !do_swap_account
)
3197 seq_printf(m
, "%s %lu\n", mem_cgroup_stat_names
[i
],
3198 mem_cgroup_read_stat(memcg
, i
) * PAGE_SIZE
);
3201 for (i
= 0; i
< MEM_CGROUP_EVENTS_NSTATS
; i
++)
3202 seq_printf(m
, "%s %lu\n", mem_cgroup_events_names
[i
],
3203 mem_cgroup_read_events(memcg
, i
));
3205 for (i
= 0; i
< NR_LRU_LISTS
; i
++)
3206 seq_printf(m
, "%s %lu\n", mem_cgroup_lru_names
[i
],
3207 mem_cgroup_nr_lru_pages(memcg
, BIT(i
)) * PAGE_SIZE
);
3209 /* Hierarchical information */
3210 memory
= memsw
= PAGE_COUNTER_MAX
;
3211 for (mi
= memcg
; mi
; mi
= parent_mem_cgroup(mi
)) {
3212 memory
= min(memory
, mi
->memory
.limit
);
3213 memsw
= min(memsw
, mi
->memsw
.limit
);
3215 seq_printf(m
, "hierarchical_memory_limit %llu\n",
3216 (u64
)memory
* PAGE_SIZE
);
3217 if (do_swap_account
)
3218 seq_printf(m
, "hierarchical_memsw_limit %llu\n",
3219 (u64
)memsw
* PAGE_SIZE
);
3221 for (i
= 0; i
< MEM_CGROUP_STAT_NSTATS
; i
++) {
3222 unsigned long long val
= 0;
3224 if (i
== MEM_CGROUP_STAT_SWAP
&& !do_swap_account
)
3226 for_each_mem_cgroup_tree(mi
, memcg
)
3227 val
+= mem_cgroup_read_stat(mi
, i
) * PAGE_SIZE
;
3228 seq_printf(m
, "total_%s %llu\n", mem_cgroup_stat_names
[i
], val
);
3231 for (i
= 0; i
< MEM_CGROUP_EVENTS_NSTATS
; i
++) {
3232 unsigned long long val
= 0;
3234 for_each_mem_cgroup_tree(mi
, memcg
)
3235 val
+= mem_cgroup_read_events(mi
, i
);
3236 seq_printf(m
, "total_%s %llu\n",
3237 mem_cgroup_events_names
[i
], val
);
3240 for (i
= 0; i
< NR_LRU_LISTS
; i
++) {
3241 unsigned long long val
= 0;
3243 for_each_mem_cgroup_tree(mi
, memcg
)
3244 val
+= mem_cgroup_nr_lru_pages(mi
, BIT(i
)) * PAGE_SIZE
;
3245 seq_printf(m
, "total_%s %llu\n", mem_cgroup_lru_names
[i
], val
);
3248 #ifdef CONFIG_DEBUG_VM
3251 struct mem_cgroup_per_zone
*mz
;
3252 struct zone_reclaim_stat
*rstat
;
3253 unsigned long recent_rotated
[2] = {0, 0};
3254 unsigned long recent_scanned
[2] = {0, 0};
3256 for_each_online_node(nid
)
3257 for (zid
= 0; zid
< MAX_NR_ZONES
; zid
++) {
3258 mz
= &memcg
->nodeinfo
[nid
]->zoneinfo
[zid
];
3259 rstat
= &mz
->lruvec
.reclaim_stat
;
3261 recent_rotated
[0] += rstat
->recent_rotated
[0];
3262 recent_rotated
[1] += rstat
->recent_rotated
[1];
3263 recent_scanned
[0] += rstat
->recent_scanned
[0];
3264 recent_scanned
[1] += rstat
->recent_scanned
[1];
3266 seq_printf(m
, "recent_rotated_anon %lu\n", recent_rotated
[0]);
3267 seq_printf(m
, "recent_rotated_file %lu\n", recent_rotated
[1]);
3268 seq_printf(m
, "recent_scanned_anon %lu\n", recent_scanned
[0]);
3269 seq_printf(m
, "recent_scanned_file %lu\n", recent_scanned
[1]);
3276 static u64
mem_cgroup_swappiness_read(struct cgroup_subsys_state
*css
,
3279 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
3281 return mem_cgroup_swappiness(memcg
);
3284 static int mem_cgroup_swappiness_write(struct cgroup_subsys_state
*css
,
3285 struct cftype
*cft
, u64 val
)
3287 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
3293 memcg
->swappiness
= val
;
3295 vm_swappiness
= val
;
3300 static void __mem_cgroup_threshold(struct mem_cgroup
*memcg
, bool swap
)
3302 struct mem_cgroup_threshold_ary
*t
;
3303 unsigned long usage
;
3308 t
= rcu_dereference(memcg
->thresholds
.primary
);
3310 t
= rcu_dereference(memcg
->memsw_thresholds
.primary
);
3315 usage
= mem_cgroup_usage(memcg
, swap
);
3318 * current_threshold points to threshold just below or equal to usage.
3319 * If it's not true, a threshold was crossed after last
3320 * call of __mem_cgroup_threshold().
3322 i
= t
->current_threshold
;
3325 * Iterate backward over array of thresholds starting from
3326 * current_threshold and check if a threshold is crossed.
3327 * If none of thresholds below usage is crossed, we read
3328 * only one element of the array here.
3330 for (; i
>= 0 && unlikely(t
->entries
[i
].threshold
> usage
); i
--)
3331 eventfd_signal(t
->entries
[i
].eventfd
, 1);
3333 /* i = current_threshold + 1 */
3337 * Iterate forward over array of thresholds starting from
3338 * current_threshold+1 and check if a threshold is crossed.
3339 * If none of thresholds above usage is crossed, we read
3340 * only one element of the array here.
3342 for (; i
< t
->size
&& unlikely(t
->entries
[i
].threshold
<= usage
); i
++)
3343 eventfd_signal(t
->entries
[i
].eventfd
, 1);
3345 /* Update current_threshold */
3346 t
->current_threshold
= i
- 1;
3351 static void mem_cgroup_threshold(struct mem_cgroup
*memcg
)
3354 __mem_cgroup_threshold(memcg
, false);
3355 if (do_swap_account
)
3356 __mem_cgroup_threshold(memcg
, true);
3358 memcg
= parent_mem_cgroup(memcg
);
3362 static int compare_thresholds(const void *a
, const void *b
)
3364 const struct mem_cgroup_threshold
*_a
= a
;
3365 const struct mem_cgroup_threshold
*_b
= b
;
3367 if (_a
->threshold
> _b
->threshold
)
3370 if (_a
->threshold
< _b
->threshold
)
3376 static int mem_cgroup_oom_notify_cb(struct mem_cgroup
*memcg
)
3378 struct mem_cgroup_eventfd_list
*ev
;
3380 spin_lock(&memcg_oom_lock
);
3382 list_for_each_entry(ev
, &memcg
->oom_notify
, list
)
3383 eventfd_signal(ev
->eventfd
, 1);
3385 spin_unlock(&memcg_oom_lock
);
3389 static void mem_cgroup_oom_notify(struct mem_cgroup
*memcg
)
3391 struct mem_cgroup
*iter
;
3393 for_each_mem_cgroup_tree(iter
, memcg
)
3394 mem_cgroup_oom_notify_cb(iter
);
3397 static int __mem_cgroup_usage_register_event(struct mem_cgroup
*memcg
,
3398 struct eventfd_ctx
*eventfd
, const char *args
, enum res_type type
)
3400 struct mem_cgroup_thresholds
*thresholds
;
3401 struct mem_cgroup_threshold_ary
*new;
3402 unsigned long threshold
;
3403 unsigned long usage
;
3406 ret
= page_counter_memparse(args
, "-1", &threshold
);
3409 threshold
<<= PAGE_SHIFT
;
3411 mutex_lock(&memcg
->thresholds_lock
);
3414 thresholds
= &memcg
->thresholds
;
3415 usage
= mem_cgroup_usage(memcg
, false);
3416 } else if (type
== _MEMSWAP
) {
3417 thresholds
= &memcg
->memsw_thresholds
;
3418 usage
= mem_cgroup_usage(memcg
, true);
3422 /* Check if a threshold crossed before adding a new one */
3423 if (thresholds
->primary
)
3424 __mem_cgroup_threshold(memcg
, type
== _MEMSWAP
);
3426 size
= thresholds
->primary
? thresholds
->primary
->size
+ 1 : 1;
3428 /* Allocate memory for new array of thresholds */
3429 new = kmalloc(sizeof(*new) + size
* sizeof(struct mem_cgroup_threshold
),
3437 /* Copy thresholds (if any) to new array */
3438 if (thresholds
->primary
) {
3439 memcpy(new->entries
, thresholds
->primary
->entries
, (size
- 1) *
3440 sizeof(struct mem_cgroup_threshold
));
3443 /* Add new threshold */
3444 new->entries
[size
- 1].eventfd
= eventfd
;
3445 new->entries
[size
- 1].threshold
= threshold
;
3447 /* Sort thresholds. Registering of new threshold isn't time-critical */
3448 sort(new->entries
, size
, sizeof(struct mem_cgroup_threshold
),
3449 compare_thresholds
, NULL
);
3451 /* Find current threshold */
3452 new->current_threshold
= -1;
3453 for (i
= 0; i
< size
; i
++) {
3454 if (new->entries
[i
].threshold
<= usage
) {
3456 * new->current_threshold will not be used until
3457 * rcu_assign_pointer(), so it's safe to increment
3460 ++new->current_threshold
;
3465 /* Free old spare buffer and save old primary buffer as spare */
3466 kfree(thresholds
->spare
);
3467 thresholds
->spare
= thresholds
->primary
;
3469 rcu_assign_pointer(thresholds
->primary
, new);
3471 /* To be sure that nobody uses thresholds */
3475 mutex_unlock(&memcg
->thresholds_lock
);
3480 static int mem_cgroup_usage_register_event(struct mem_cgroup
*memcg
,
3481 struct eventfd_ctx
*eventfd
, const char *args
)
3483 return __mem_cgroup_usage_register_event(memcg
, eventfd
, args
, _MEM
);
3486 static int memsw_cgroup_usage_register_event(struct mem_cgroup
*memcg
,
3487 struct eventfd_ctx
*eventfd
, const char *args
)
3489 return __mem_cgroup_usage_register_event(memcg
, eventfd
, args
, _MEMSWAP
);
3492 static void __mem_cgroup_usage_unregister_event(struct mem_cgroup
*memcg
,
3493 struct eventfd_ctx
*eventfd
, enum res_type type
)
3495 struct mem_cgroup_thresholds
*thresholds
;
3496 struct mem_cgroup_threshold_ary
*new;
3497 unsigned long usage
;
3500 mutex_lock(&memcg
->thresholds_lock
);
3503 thresholds
= &memcg
->thresholds
;
3504 usage
= mem_cgroup_usage(memcg
, false);
3505 } else if (type
== _MEMSWAP
) {
3506 thresholds
= &memcg
->memsw_thresholds
;
3507 usage
= mem_cgroup_usage(memcg
, true);
3511 if (!thresholds
->primary
)
3514 /* Check if a threshold crossed before removing */
3515 __mem_cgroup_threshold(memcg
, type
== _MEMSWAP
);
3517 /* Calculate new number of threshold */
3519 for (i
= 0; i
< thresholds
->primary
->size
; i
++) {
3520 if (thresholds
->primary
->entries
[i
].eventfd
!= eventfd
)
3524 new = thresholds
->spare
;
3526 /* Set thresholds array to NULL if we don't have thresholds */
3535 /* Copy thresholds and find current threshold */
3536 new->current_threshold
= -1;
3537 for (i
= 0, j
= 0; i
< thresholds
->primary
->size
; i
++) {
3538 if (thresholds
->primary
->entries
[i
].eventfd
== eventfd
)
3541 new->entries
[j
] = thresholds
->primary
->entries
[i
];
3542 if (new->entries
[j
].threshold
<= usage
) {
3544 * new->current_threshold will not be used
3545 * until rcu_assign_pointer(), so it's safe to increment
3548 ++new->current_threshold
;
3554 /* Swap primary and spare array */
3555 thresholds
->spare
= thresholds
->primary
;
3556 /* If all events are unregistered, free the spare array */
3558 kfree(thresholds
->spare
);
3559 thresholds
->spare
= NULL
;
3562 rcu_assign_pointer(thresholds
->primary
, new);
3564 /* To be sure that nobody uses thresholds */
3567 mutex_unlock(&memcg
->thresholds_lock
);
3570 static void mem_cgroup_usage_unregister_event(struct mem_cgroup
*memcg
,
3571 struct eventfd_ctx
*eventfd
)
3573 return __mem_cgroup_usage_unregister_event(memcg
, eventfd
, _MEM
);
3576 static void memsw_cgroup_usage_unregister_event(struct mem_cgroup
*memcg
,
3577 struct eventfd_ctx
*eventfd
)
3579 return __mem_cgroup_usage_unregister_event(memcg
, eventfd
, _MEMSWAP
);
3582 static int mem_cgroup_oom_register_event(struct mem_cgroup
*memcg
,
3583 struct eventfd_ctx
*eventfd
, const char *args
)
3585 struct mem_cgroup_eventfd_list
*event
;
3587 event
= kmalloc(sizeof(*event
), GFP_KERNEL
);
3591 spin_lock(&memcg_oom_lock
);
3593 event
->eventfd
= eventfd
;
3594 list_add(&event
->list
, &memcg
->oom_notify
);
3596 /* already in OOM ? */
3597 if (memcg
->under_oom
)
3598 eventfd_signal(eventfd
, 1);
3599 spin_unlock(&memcg_oom_lock
);
3604 static void mem_cgroup_oom_unregister_event(struct mem_cgroup
*memcg
,
3605 struct eventfd_ctx
*eventfd
)
3607 struct mem_cgroup_eventfd_list
*ev
, *tmp
;
3609 spin_lock(&memcg_oom_lock
);
3611 list_for_each_entry_safe(ev
, tmp
, &memcg
->oom_notify
, list
) {
3612 if (ev
->eventfd
== eventfd
) {
3613 list_del(&ev
->list
);
3618 spin_unlock(&memcg_oom_lock
);
3621 static int mem_cgroup_oom_control_read(struct seq_file
*sf
, void *v
)
3623 struct mem_cgroup
*memcg
= mem_cgroup_from_css(seq_css(sf
));
3625 seq_printf(sf
, "oom_kill_disable %d\n", memcg
->oom_kill_disable
);
3626 seq_printf(sf
, "under_oom %d\n", (bool)memcg
->under_oom
);
3630 static int mem_cgroup_oom_control_write(struct cgroup_subsys_state
*css
,
3631 struct cftype
*cft
, u64 val
)
3633 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
3635 /* cannot set to root cgroup and only 0 and 1 are allowed */
3636 if (!css
->parent
|| !((val
== 0) || (val
== 1)))
3639 memcg
->oom_kill_disable
= val
;
3641 memcg_oom_recover(memcg
);
3646 #ifdef CONFIG_MEMCG_KMEM
3647 static int memcg_init_kmem(struct mem_cgroup
*memcg
, struct cgroup_subsys
*ss
)
3651 ret
= memcg_propagate_kmem(memcg
);
3655 return mem_cgroup_sockets_init(memcg
, ss
);
3658 static void memcg_deactivate_kmem(struct mem_cgroup
*memcg
)
3660 struct cgroup_subsys_state
*css
;
3661 struct mem_cgroup
*parent
, *child
;
3664 if (!memcg
->kmem_acct_active
)
3668 * Clear the 'active' flag before clearing memcg_caches arrays entries.
3669 * Since we take the slab_mutex in memcg_deactivate_kmem_caches(), it
3670 * guarantees no cache will be created for this cgroup after we are
3671 * done (see memcg_create_kmem_cache()).
3673 memcg
->kmem_acct_active
= false;
3675 memcg_deactivate_kmem_caches(memcg
);
3677 kmemcg_id
= memcg
->kmemcg_id
;
3678 BUG_ON(kmemcg_id
< 0);
3680 parent
= parent_mem_cgroup(memcg
);
3682 parent
= root_mem_cgroup
;
3685 * Change kmemcg_id of this cgroup and all its descendants to the
3686 * parent's id, and then move all entries from this cgroup's list_lrus
3687 * to ones of the parent. After we have finished, all list_lrus
3688 * corresponding to this cgroup are guaranteed to remain empty. The
3689 * ordering is imposed by list_lru_node->lock taken by
3690 * memcg_drain_all_list_lrus().
3692 css_for_each_descendant_pre(css
, &memcg
->css
) {
3693 child
= mem_cgroup_from_css(css
);
3694 BUG_ON(child
->kmemcg_id
!= kmemcg_id
);
3695 child
->kmemcg_id
= parent
->kmemcg_id
;
3696 if (!memcg
->use_hierarchy
)
3699 memcg_drain_all_list_lrus(kmemcg_id
, parent
->kmemcg_id
);
3701 memcg_free_cache_id(kmemcg_id
);
3704 static void memcg_destroy_kmem(struct mem_cgroup
*memcg
)
3706 if (memcg
->kmem_acct_activated
) {
3707 memcg_destroy_kmem_caches(memcg
);
3708 static_key_slow_dec(&memcg_kmem_enabled_key
);
3709 WARN_ON(page_counter_read(&memcg
->kmem
));
3711 mem_cgroup_sockets_destroy(memcg
);
3714 static int memcg_init_kmem(struct mem_cgroup
*memcg
, struct cgroup_subsys
*ss
)
3719 static void memcg_deactivate_kmem(struct mem_cgroup
*memcg
)
3723 static void memcg_destroy_kmem(struct mem_cgroup
*memcg
)
3728 #ifdef CONFIG_CGROUP_WRITEBACK
3730 struct list_head
*mem_cgroup_cgwb_list(struct mem_cgroup
*memcg
)
3732 return &memcg
->cgwb_list
;
3735 static int memcg_wb_domain_init(struct mem_cgroup
*memcg
, gfp_t gfp
)
3737 return wb_domain_init(&memcg
->cgwb_domain
, gfp
);
3740 static void memcg_wb_domain_exit(struct mem_cgroup
*memcg
)
3742 wb_domain_exit(&memcg
->cgwb_domain
);
3745 static void memcg_wb_domain_size_changed(struct mem_cgroup
*memcg
)
3747 wb_domain_size_changed(&memcg
->cgwb_domain
);
3750 struct wb_domain
*mem_cgroup_wb_domain(struct bdi_writeback
*wb
)
3752 struct mem_cgroup
*memcg
= mem_cgroup_from_css(wb
->memcg_css
);
3754 if (!memcg
->css
.parent
)
3757 return &memcg
->cgwb_domain
;
3761 * mem_cgroup_wb_stats - retrieve writeback related stats from its memcg
3762 * @wb: bdi_writeback in question
3763 * @pfilepages: out parameter for number of file pages
3764 * @pheadroom: out parameter for number of allocatable pages according to memcg
3765 * @pdirty: out parameter for number of dirty pages
3766 * @pwriteback: out parameter for number of pages under writeback
3768 * Determine the numbers of file, headroom, dirty, and writeback pages in
3769 * @wb's memcg. File, dirty and writeback are self-explanatory. Headroom
3770 * is a bit more involved.
3772 * A memcg's headroom is "min(max, high) - used". In the hierarchy, the
3773 * headroom is calculated as the lowest headroom of itself and the
3774 * ancestors. Note that this doesn't consider the actual amount of
3775 * available memory in the system. The caller should further cap
3776 * *@pheadroom accordingly.
3778 void mem_cgroup_wb_stats(struct bdi_writeback
*wb
, unsigned long *pfilepages
,
3779 unsigned long *pheadroom
, unsigned long *pdirty
,
3780 unsigned long *pwriteback
)
3782 struct mem_cgroup
*memcg
= mem_cgroup_from_css(wb
->memcg_css
);
3783 struct mem_cgroup
*parent
;
3785 *pdirty
= mem_cgroup_read_stat(memcg
, MEM_CGROUP_STAT_DIRTY
);
3787 /* this should eventually include NR_UNSTABLE_NFS */
3788 *pwriteback
= mem_cgroup_read_stat(memcg
, MEM_CGROUP_STAT_WRITEBACK
);
3789 *pfilepages
= mem_cgroup_nr_lru_pages(memcg
, (1 << LRU_INACTIVE_FILE
) |
3790 (1 << LRU_ACTIVE_FILE
));
3791 *pheadroom
= PAGE_COUNTER_MAX
;
3793 while ((parent
= parent_mem_cgroup(memcg
))) {
3794 unsigned long ceiling
= min(memcg
->memory
.limit
, memcg
->high
);
3795 unsigned long used
= page_counter_read(&memcg
->memory
);
3797 *pheadroom
= min(*pheadroom
, ceiling
- min(ceiling
, used
));
3802 #else /* CONFIG_CGROUP_WRITEBACK */
3804 static int memcg_wb_domain_init(struct mem_cgroup
*memcg
, gfp_t gfp
)
3809 static void memcg_wb_domain_exit(struct mem_cgroup
*memcg
)
3813 static void memcg_wb_domain_size_changed(struct mem_cgroup
*memcg
)
3817 #endif /* CONFIG_CGROUP_WRITEBACK */
3820 * DO NOT USE IN NEW FILES.
3822 * "cgroup.event_control" implementation.
3824 * This is way over-engineered. It tries to support fully configurable
3825 * events for each user. Such level of flexibility is completely
3826 * unnecessary especially in the light of the planned unified hierarchy.
3828 * Please deprecate this and replace with something simpler if at all
3833 * Unregister event and free resources.
3835 * Gets called from workqueue.
3837 static void memcg_event_remove(struct work_struct
*work
)
3839 struct mem_cgroup_event
*event
=
3840 container_of(work
, struct mem_cgroup_event
, remove
);
3841 struct mem_cgroup
*memcg
= event
->memcg
;
3843 remove_wait_queue(event
->wqh
, &event
->wait
);
3845 event
->unregister_event(memcg
, event
->eventfd
);
3847 /* Notify userspace the event is going away. */
3848 eventfd_signal(event
->eventfd
, 1);
3850 eventfd_ctx_put(event
->eventfd
);
3852 css_put(&memcg
->css
);
3856 * Gets called on POLLHUP on eventfd when user closes it.
3858 * Called with wqh->lock held and interrupts disabled.
3860 static int memcg_event_wake(wait_queue_t
*wait
, unsigned mode
,
3861 int sync
, void *key
)
3863 struct mem_cgroup_event
*event
=
3864 container_of(wait
, struct mem_cgroup_event
, wait
);
3865 struct mem_cgroup
*memcg
= event
->memcg
;
3866 unsigned long flags
= (unsigned long)key
;
3868 if (flags
& POLLHUP
) {
3870 * If the event has been detached at cgroup removal, we
3871 * can simply return knowing the other side will cleanup
3874 * We can't race against event freeing since the other
3875 * side will require wqh->lock via remove_wait_queue(),
3878 spin_lock(&memcg
->event_list_lock
);
3879 if (!list_empty(&event
->list
)) {
3880 list_del_init(&event
->list
);
3882 * We are in atomic context, but cgroup_event_remove()
3883 * may sleep, so we have to call it in workqueue.
3885 schedule_work(&event
->remove
);
3887 spin_unlock(&memcg
->event_list_lock
);
3893 static void memcg_event_ptable_queue_proc(struct file
*file
,
3894 wait_queue_head_t
*wqh
, poll_table
*pt
)
3896 struct mem_cgroup_event
*event
=
3897 container_of(pt
, struct mem_cgroup_event
, pt
);
3900 add_wait_queue(wqh
, &event
->wait
);
3904 * DO NOT USE IN NEW FILES.
3906 * Parse input and register new cgroup event handler.
3908 * Input must be in format '<event_fd> <control_fd> <args>'.
3909 * Interpretation of args is defined by control file implementation.
3911 static ssize_t
memcg_write_event_control(struct kernfs_open_file
*of
,
3912 char *buf
, size_t nbytes
, loff_t off
)
3914 struct cgroup_subsys_state
*css
= of_css(of
);
3915 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
3916 struct mem_cgroup_event
*event
;
3917 struct cgroup_subsys_state
*cfile_css
;
3918 unsigned int efd
, cfd
;
3925 buf
= strstrip(buf
);
3927 efd
= simple_strtoul(buf
, &endp
, 10);
3932 cfd
= simple_strtoul(buf
, &endp
, 10);
3933 if ((*endp
!= ' ') && (*endp
!= '\0'))
3937 event
= kzalloc(sizeof(*event
), GFP_KERNEL
);
3941 event
->memcg
= memcg
;
3942 INIT_LIST_HEAD(&event
->list
);
3943 init_poll_funcptr(&event
->pt
, memcg_event_ptable_queue_proc
);
3944 init_waitqueue_func_entry(&event
->wait
, memcg_event_wake
);
3945 INIT_WORK(&event
->remove
, memcg_event_remove
);
3953 event
->eventfd
= eventfd_ctx_fileget(efile
.file
);
3954 if (IS_ERR(event
->eventfd
)) {
3955 ret
= PTR_ERR(event
->eventfd
);
3962 goto out_put_eventfd
;
3965 /* the process need read permission on control file */
3966 /* AV: shouldn't we check that it's been opened for read instead? */
3967 ret
= inode_permission(file_inode(cfile
.file
), MAY_READ
);
3972 * Determine the event callbacks and set them in @event. This used
3973 * to be done via struct cftype but cgroup core no longer knows
3974 * about these events. The following is crude but the whole thing
3975 * is for compatibility anyway.
3977 * DO NOT ADD NEW FILES.
3979 name
= cfile
.file
->f_path
.dentry
->d_name
.name
;
3981 if (!strcmp(name
, "memory.usage_in_bytes")) {
3982 event
->register_event
= mem_cgroup_usage_register_event
;
3983 event
->unregister_event
= mem_cgroup_usage_unregister_event
;
3984 } else if (!strcmp(name
, "memory.oom_control")) {
3985 event
->register_event
= mem_cgroup_oom_register_event
;
3986 event
->unregister_event
= mem_cgroup_oom_unregister_event
;
3987 } else if (!strcmp(name
, "memory.pressure_level")) {
3988 event
->register_event
= vmpressure_register_event
;
3989 event
->unregister_event
= vmpressure_unregister_event
;
3990 } else if (!strcmp(name
, "memory.memsw.usage_in_bytes")) {
3991 event
->register_event
= memsw_cgroup_usage_register_event
;
3992 event
->unregister_event
= memsw_cgroup_usage_unregister_event
;
3999 * Verify @cfile should belong to @css. Also, remaining events are
4000 * automatically removed on cgroup destruction but the removal is
4001 * asynchronous, so take an extra ref on @css.
4003 cfile_css
= css_tryget_online_from_dir(cfile
.file
->f_path
.dentry
->d_parent
,
4004 &memory_cgrp_subsys
);
4006 if (IS_ERR(cfile_css
))
4008 if (cfile_css
!= css
) {
4013 ret
= event
->register_event(memcg
, event
->eventfd
, buf
);
4017 efile
.file
->f_op
->poll(efile
.file
, &event
->pt
);
4019 spin_lock(&memcg
->event_list_lock
);
4020 list_add(&event
->list
, &memcg
->event_list
);
4021 spin_unlock(&memcg
->event_list_lock
);
4033 eventfd_ctx_put(event
->eventfd
);
4042 static struct cftype mem_cgroup_legacy_files
[] = {
4044 .name
= "usage_in_bytes",
4045 .private = MEMFILE_PRIVATE(_MEM
, RES_USAGE
),
4046 .read_u64
= mem_cgroup_read_u64
,
4049 .name
= "max_usage_in_bytes",
4050 .private = MEMFILE_PRIVATE(_MEM
, RES_MAX_USAGE
),
4051 .write
= mem_cgroup_reset
,
4052 .read_u64
= mem_cgroup_read_u64
,
4055 .name
= "limit_in_bytes",
4056 .private = MEMFILE_PRIVATE(_MEM
, RES_LIMIT
),
4057 .write
= mem_cgroup_write
,
4058 .read_u64
= mem_cgroup_read_u64
,
4061 .name
= "soft_limit_in_bytes",
4062 .private = MEMFILE_PRIVATE(_MEM
, RES_SOFT_LIMIT
),
4063 .write
= mem_cgroup_write
,
4064 .read_u64
= mem_cgroup_read_u64
,
4068 .private = MEMFILE_PRIVATE(_MEM
, RES_FAILCNT
),
4069 .write
= mem_cgroup_reset
,
4070 .read_u64
= mem_cgroup_read_u64
,
4074 .seq_show
= memcg_stat_show
,
4077 .name
= "force_empty",
4078 .write
= mem_cgroup_force_empty_write
,
4081 .name
= "use_hierarchy",
4082 .write_u64
= mem_cgroup_hierarchy_write
,
4083 .read_u64
= mem_cgroup_hierarchy_read
,
4086 .name
= "cgroup.event_control", /* XXX: for compat */
4087 .write
= memcg_write_event_control
,
4088 .flags
= CFTYPE_NO_PREFIX
,
4092 .name
= "swappiness",
4093 .read_u64
= mem_cgroup_swappiness_read
,
4094 .write_u64
= mem_cgroup_swappiness_write
,
4097 .name
= "move_charge_at_immigrate",
4098 .read_u64
= mem_cgroup_move_charge_read
,
4099 .write_u64
= mem_cgroup_move_charge_write
,
4102 .name
= "oom_control",
4103 .seq_show
= mem_cgroup_oom_control_read
,
4104 .write_u64
= mem_cgroup_oom_control_write
,
4105 .private = MEMFILE_PRIVATE(_OOM_TYPE
, OOM_CONTROL
),
4108 .name
= "pressure_level",
4112 .name
= "numa_stat",
4113 .seq_show
= memcg_numa_stat_show
,
4116 #ifdef CONFIG_MEMCG_KMEM
4118 .name
= "kmem.limit_in_bytes",
4119 .private = MEMFILE_PRIVATE(_KMEM
, RES_LIMIT
),
4120 .write
= mem_cgroup_write
,
4121 .read_u64
= mem_cgroup_read_u64
,
4124 .name
= "kmem.usage_in_bytes",
4125 .private = MEMFILE_PRIVATE(_KMEM
, RES_USAGE
),
4126 .read_u64
= mem_cgroup_read_u64
,
4129 .name
= "kmem.failcnt",
4130 .private = MEMFILE_PRIVATE(_KMEM
, RES_FAILCNT
),
4131 .write
= mem_cgroup_reset
,
4132 .read_u64
= mem_cgroup_read_u64
,
4135 .name
= "kmem.max_usage_in_bytes",
4136 .private = MEMFILE_PRIVATE(_KMEM
, RES_MAX_USAGE
),
4137 .write
= mem_cgroup_reset
,
4138 .read_u64
= mem_cgroup_read_u64
,
4140 #ifdef CONFIG_SLABINFO
4142 .name
= "kmem.slabinfo",
4143 .seq_start
= slab_start
,
4144 .seq_next
= slab_next
,
4145 .seq_stop
= slab_stop
,
4146 .seq_show
= memcg_slab_show
,
4150 { }, /* terminate */
4153 static int alloc_mem_cgroup_per_zone_info(struct mem_cgroup
*memcg
, int node
)
4155 struct mem_cgroup_per_node
*pn
;
4156 struct mem_cgroup_per_zone
*mz
;
4157 int zone
, tmp
= node
;
4159 * This routine is called against possible nodes.
4160 * But it's BUG to call kmalloc() against offline node.
4162 * TODO: this routine can waste much memory for nodes which will
4163 * never be onlined. It's better to use memory hotplug callback
4166 if (!node_state(node
, N_NORMAL_MEMORY
))
4168 pn
= kzalloc_node(sizeof(*pn
), GFP_KERNEL
, tmp
);
4172 for (zone
= 0; zone
< MAX_NR_ZONES
; zone
++) {
4173 mz
= &pn
->zoneinfo
[zone
];
4174 lruvec_init(&mz
->lruvec
);
4175 mz
->usage_in_excess
= 0;
4176 mz
->on_tree
= false;
4179 memcg
->nodeinfo
[node
] = pn
;
4183 static void free_mem_cgroup_per_zone_info(struct mem_cgroup
*memcg
, int node
)
4185 kfree(memcg
->nodeinfo
[node
]);
4188 static struct mem_cgroup
*mem_cgroup_alloc(void)
4190 struct mem_cgroup
*memcg
;
4193 size
= sizeof(struct mem_cgroup
);
4194 size
+= nr_node_ids
* sizeof(struct mem_cgroup_per_node
*);
4196 memcg
= kzalloc(size
, GFP_KERNEL
);
4200 memcg
->stat
= alloc_percpu(struct mem_cgroup_stat_cpu
);
4204 if (memcg_wb_domain_init(memcg
, GFP_KERNEL
))
4210 free_percpu(memcg
->stat
);
4217 * At destroying mem_cgroup, references from swap_cgroup can remain.
4218 * (scanning all at force_empty is too costly...)
4220 * Instead of clearing all references at force_empty, we remember
4221 * the number of reference from swap_cgroup and free mem_cgroup when
4222 * it goes down to 0.
4224 * Removal of cgroup itself succeeds regardless of refs from swap.
4227 static void __mem_cgroup_free(struct mem_cgroup
*memcg
)
4231 mem_cgroup_remove_from_trees(memcg
);
4234 free_mem_cgroup_per_zone_info(memcg
, node
);
4236 free_percpu(memcg
->stat
);
4237 memcg_wb_domain_exit(memcg
);
4242 * Returns the parent mem_cgroup in memcgroup hierarchy with hierarchy enabled.
4244 struct mem_cgroup
*parent_mem_cgroup(struct mem_cgroup
*memcg
)
4246 if (!memcg
->memory
.parent
)
4248 return mem_cgroup_from_counter(memcg
->memory
.parent
, memory
);
4250 EXPORT_SYMBOL(parent_mem_cgroup
);
4252 static struct cgroup_subsys_state
* __ref
4253 mem_cgroup_css_alloc(struct cgroup_subsys_state
*parent_css
)
4255 struct mem_cgroup
*memcg
;
4256 long error
= -ENOMEM
;
4259 memcg
= mem_cgroup_alloc();
4261 return ERR_PTR(error
);
4264 if (alloc_mem_cgroup_per_zone_info(memcg
, node
))
4268 if (parent_css
== NULL
) {
4269 root_mem_cgroup
= memcg
;
4270 mem_cgroup_root_css
= &memcg
->css
;
4271 page_counter_init(&memcg
->memory
, NULL
);
4272 memcg
->high
= PAGE_COUNTER_MAX
;
4273 memcg
->soft_limit
= PAGE_COUNTER_MAX
;
4274 page_counter_init(&memcg
->memsw
, NULL
);
4275 page_counter_init(&memcg
->kmem
, NULL
);
4278 memcg
->last_scanned_node
= MAX_NUMNODES
;
4279 INIT_LIST_HEAD(&memcg
->oom_notify
);
4280 memcg
->move_charge_at_immigrate
= 0;
4281 mutex_init(&memcg
->thresholds_lock
);
4282 spin_lock_init(&memcg
->move_lock
);
4283 vmpressure_init(&memcg
->vmpressure
);
4284 INIT_LIST_HEAD(&memcg
->event_list
);
4285 spin_lock_init(&memcg
->event_list_lock
);
4286 #ifdef CONFIG_MEMCG_KMEM
4287 memcg
->kmemcg_id
= -1;
4289 #ifdef CONFIG_CGROUP_WRITEBACK
4290 INIT_LIST_HEAD(&memcg
->cgwb_list
);
4295 __mem_cgroup_free(memcg
);
4296 return ERR_PTR(error
);
4300 mem_cgroup_css_online(struct cgroup_subsys_state
*css
)
4302 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
4303 struct mem_cgroup
*parent
= mem_cgroup_from_css(css
->parent
);
4306 if (css
->id
> MEM_CGROUP_ID_MAX
)
4312 mutex_lock(&memcg_create_mutex
);
4314 memcg
->use_hierarchy
= parent
->use_hierarchy
;
4315 memcg
->oom_kill_disable
= parent
->oom_kill_disable
;
4316 memcg
->swappiness
= mem_cgroup_swappiness(parent
);
4318 if (parent
->use_hierarchy
) {
4319 page_counter_init(&memcg
->memory
, &parent
->memory
);
4320 memcg
->high
= PAGE_COUNTER_MAX
;
4321 memcg
->soft_limit
= PAGE_COUNTER_MAX
;
4322 page_counter_init(&memcg
->memsw
, &parent
->memsw
);
4323 page_counter_init(&memcg
->kmem
, &parent
->kmem
);
4326 * No need to take a reference to the parent because cgroup
4327 * core guarantees its existence.
4330 page_counter_init(&memcg
->memory
, NULL
);
4331 memcg
->high
= PAGE_COUNTER_MAX
;
4332 memcg
->soft_limit
= PAGE_COUNTER_MAX
;
4333 page_counter_init(&memcg
->memsw
, NULL
);
4334 page_counter_init(&memcg
->kmem
, NULL
);
4336 * Deeper hierachy with use_hierarchy == false doesn't make
4337 * much sense so let cgroup subsystem know about this
4338 * unfortunate state in our controller.
4340 if (parent
!= root_mem_cgroup
)
4341 memory_cgrp_subsys
.broken_hierarchy
= true;
4343 mutex_unlock(&memcg_create_mutex
);
4345 ret
= memcg_init_kmem(memcg
, &memory_cgrp_subsys
);
4350 * Make sure the memcg is initialized: mem_cgroup_iter()
4351 * orders reading memcg->initialized against its callers
4352 * reading the memcg members.
4354 smp_store_release(&memcg
->initialized
, 1);
4359 static void mem_cgroup_css_offline(struct cgroup_subsys_state
*css
)
4361 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
4362 struct mem_cgroup_event
*event
, *tmp
;
4365 * Unregister events and notify userspace.
4366 * Notify userspace about cgroup removing only after rmdir of cgroup
4367 * directory to avoid race between userspace and kernelspace.
4369 spin_lock(&memcg
->event_list_lock
);
4370 list_for_each_entry_safe(event
, tmp
, &memcg
->event_list
, list
) {
4371 list_del_init(&event
->list
);
4372 schedule_work(&event
->remove
);
4374 spin_unlock(&memcg
->event_list_lock
);
4376 vmpressure_cleanup(&memcg
->vmpressure
);
4378 memcg_deactivate_kmem(memcg
);
4380 wb_memcg_offline(memcg
);
4383 static void mem_cgroup_css_free(struct cgroup_subsys_state
*css
)
4385 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
4387 memcg_destroy_kmem(memcg
);
4388 __mem_cgroup_free(memcg
);
4392 * mem_cgroup_css_reset - reset the states of a mem_cgroup
4393 * @css: the target css
4395 * Reset the states of the mem_cgroup associated with @css. This is
4396 * invoked when the userland requests disabling on the default hierarchy
4397 * but the memcg is pinned through dependency. The memcg should stop
4398 * applying policies and should revert to the vanilla state as it may be
4399 * made visible again.
4401 * The current implementation only resets the essential configurations.
4402 * This needs to be expanded to cover all the visible parts.
4404 static void mem_cgroup_css_reset(struct cgroup_subsys_state
*css
)
4406 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
4408 mem_cgroup_resize_limit(memcg
, PAGE_COUNTER_MAX
);
4409 mem_cgroup_resize_memsw_limit(memcg
, PAGE_COUNTER_MAX
);
4410 memcg_update_kmem_limit(memcg
, PAGE_COUNTER_MAX
);
4412 memcg
->high
= PAGE_COUNTER_MAX
;
4413 memcg
->soft_limit
= PAGE_COUNTER_MAX
;
4414 memcg_wb_domain_size_changed(memcg
);
4418 /* Handlers for move charge at task migration. */
4419 static int mem_cgroup_do_precharge(unsigned long count
)
4423 /* Try a single bulk charge without reclaim first */
4424 ret
= try_charge(mc
.to
, GFP_KERNEL
& ~__GFP_WAIT
, count
);
4426 mc
.precharge
+= count
;
4430 /* Try charges one by one with reclaim */
4432 ret
= try_charge(mc
.to
, GFP_KERNEL
& ~__GFP_NORETRY
, 1);
4442 * get_mctgt_type - get target type of moving charge
4443 * @vma: the vma the pte to be checked belongs
4444 * @addr: the address corresponding to the pte to be checked
4445 * @ptent: the pte to be checked
4446 * @target: the pointer the target page or swap ent will be stored(can be NULL)
4449 * 0(MC_TARGET_NONE): if the pte is not a target for move charge.
4450 * 1(MC_TARGET_PAGE): if the page corresponding to this pte is a target for
4451 * move charge. if @target is not NULL, the page is stored in target->page
4452 * with extra refcnt got(Callers should handle it).
4453 * 2(MC_TARGET_SWAP): if the swap entry corresponding to this pte is a
4454 * target for charge migration. if @target is not NULL, the entry is stored
4457 * Called with pte lock held.
4464 enum mc_target_type
{
4470 static struct page
*mc_handle_present_pte(struct vm_area_struct
*vma
,
4471 unsigned long addr
, pte_t ptent
)
4473 struct page
*page
= vm_normal_page(vma
, addr
, ptent
);
4475 if (!page
|| !page_mapped(page
))
4477 if (PageAnon(page
)) {
4478 if (!(mc
.flags
& MOVE_ANON
))
4481 if (!(mc
.flags
& MOVE_FILE
))
4484 if (!get_page_unless_zero(page
))
4491 static struct page
*mc_handle_swap_pte(struct vm_area_struct
*vma
,
4492 unsigned long addr
, pte_t ptent
, swp_entry_t
*entry
)
4494 struct page
*page
= NULL
;
4495 swp_entry_t ent
= pte_to_swp_entry(ptent
);
4497 if (!(mc
.flags
& MOVE_ANON
) || non_swap_entry(ent
))
4500 * Because lookup_swap_cache() updates some statistics counter,
4501 * we call find_get_page() with swapper_space directly.
4503 page
= find_get_page(swap_address_space(ent
), ent
.val
);
4504 if (do_swap_account
)
4505 entry
->val
= ent
.val
;
4510 static struct page
*mc_handle_swap_pte(struct vm_area_struct
*vma
,
4511 unsigned long addr
, pte_t ptent
, swp_entry_t
*entry
)
4517 static struct page
*mc_handle_file_pte(struct vm_area_struct
*vma
,
4518 unsigned long addr
, pte_t ptent
, swp_entry_t
*entry
)
4520 struct page
*page
= NULL
;
4521 struct address_space
*mapping
;
4524 if (!vma
->vm_file
) /* anonymous vma */
4526 if (!(mc
.flags
& MOVE_FILE
))
4529 mapping
= vma
->vm_file
->f_mapping
;
4530 pgoff
= linear_page_index(vma
, addr
);
4532 /* page is moved even if it's not RSS of this task(page-faulted). */
4534 /* shmem/tmpfs may report page out on swap: account for that too. */
4535 if (shmem_mapping(mapping
)) {
4536 page
= find_get_entry(mapping
, pgoff
);
4537 if (radix_tree_exceptional_entry(page
)) {
4538 swp_entry_t swp
= radix_to_swp_entry(page
);
4539 if (do_swap_account
)
4541 page
= find_get_page(swap_address_space(swp
), swp
.val
);
4544 page
= find_get_page(mapping
, pgoff
);
4546 page
= find_get_page(mapping
, pgoff
);
4552 * mem_cgroup_move_account - move account of the page
4554 * @nr_pages: number of regular pages (>1 for huge pages)
4555 * @from: mem_cgroup which the page is moved from.
4556 * @to: mem_cgroup which the page is moved to. @from != @to.
4558 * The caller must confirm following.
4559 * - page is not on LRU (isolate_page() is useful.)
4560 * - compound_lock is held when nr_pages > 1
4562 * This function doesn't do "charge" to new cgroup and doesn't do "uncharge"
4565 static int mem_cgroup_move_account(struct page
*page
,
4566 unsigned int nr_pages
,
4567 struct mem_cgroup
*from
,
4568 struct mem_cgroup
*to
)
4570 unsigned long flags
;
4574 VM_BUG_ON(from
== to
);
4575 VM_BUG_ON_PAGE(PageLRU(page
), page
);
4577 * The page is isolated from LRU. So, collapse function
4578 * will not handle this page. But page splitting can happen.
4579 * Do this check under compound_page_lock(). The caller should
4583 if (nr_pages
> 1 && !PageTransHuge(page
))
4587 * Prevent mem_cgroup_migrate() from looking at page->mem_cgroup
4588 * of its source page while we change it: page migration takes
4589 * both pages off the LRU, but page cache replacement doesn't.
4591 if (!trylock_page(page
))
4595 if (page
->mem_cgroup
!= from
)
4598 anon
= PageAnon(page
);
4600 spin_lock_irqsave(&from
->move_lock
, flags
);
4602 if (!anon
&& page_mapped(page
)) {
4603 __this_cpu_sub(from
->stat
->count
[MEM_CGROUP_STAT_FILE_MAPPED
],
4605 __this_cpu_add(to
->stat
->count
[MEM_CGROUP_STAT_FILE_MAPPED
],
4610 * move_lock grabbed above and caller set from->moving_account, so
4611 * mem_cgroup_update_page_stat() will serialize updates to PageDirty.
4612 * So mapping should be stable for dirty pages.
4614 if (!anon
&& PageDirty(page
)) {
4615 struct address_space
*mapping
= page_mapping(page
);
4617 if (mapping_cap_account_dirty(mapping
)) {
4618 __this_cpu_sub(from
->stat
->count
[MEM_CGROUP_STAT_DIRTY
],
4620 __this_cpu_add(to
->stat
->count
[MEM_CGROUP_STAT_DIRTY
],
4625 if (PageWriteback(page
)) {
4626 __this_cpu_sub(from
->stat
->count
[MEM_CGROUP_STAT_WRITEBACK
],
4628 __this_cpu_add(to
->stat
->count
[MEM_CGROUP_STAT_WRITEBACK
],
4633 * It is safe to change page->mem_cgroup here because the page
4634 * is referenced, charged, and isolated - we can't race with
4635 * uncharging, charging, migration, or LRU putback.
4638 /* caller should have done css_get */
4639 page
->mem_cgroup
= to
;
4640 spin_unlock_irqrestore(&from
->move_lock
, flags
);
4644 local_irq_disable();
4645 mem_cgroup_charge_statistics(to
, page
, nr_pages
);
4646 memcg_check_events(to
, page
);
4647 mem_cgroup_charge_statistics(from
, page
, -nr_pages
);
4648 memcg_check_events(from
, page
);
4656 static enum mc_target_type
get_mctgt_type(struct vm_area_struct
*vma
,
4657 unsigned long addr
, pte_t ptent
, union mc_target
*target
)
4659 struct page
*page
= NULL
;
4660 enum mc_target_type ret
= MC_TARGET_NONE
;
4661 swp_entry_t ent
= { .val
= 0 };
4663 if (pte_present(ptent
))
4664 page
= mc_handle_present_pte(vma
, addr
, ptent
);
4665 else if (is_swap_pte(ptent
))
4666 page
= mc_handle_swap_pte(vma
, addr
, ptent
, &ent
);
4667 else if (pte_none(ptent
))
4668 page
= mc_handle_file_pte(vma
, addr
, ptent
, &ent
);
4670 if (!page
&& !ent
.val
)
4674 * Do only loose check w/o serialization.
4675 * mem_cgroup_move_account() checks the page is valid or
4676 * not under LRU exclusion.
4678 if (page
->mem_cgroup
== mc
.from
) {
4679 ret
= MC_TARGET_PAGE
;
4681 target
->page
= page
;
4683 if (!ret
|| !target
)
4686 /* There is a swap entry and a page doesn't exist or isn't charged */
4687 if (ent
.val
&& !ret
&&
4688 mem_cgroup_id(mc
.from
) == lookup_swap_cgroup_id(ent
)) {
4689 ret
= MC_TARGET_SWAP
;
4696 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
4698 * We don't consider swapping or file mapped pages because THP does not
4699 * support them for now.
4700 * Caller should make sure that pmd_trans_huge(pmd) is true.
4702 static enum mc_target_type
get_mctgt_type_thp(struct vm_area_struct
*vma
,
4703 unsigned long addr
, pmd_t pmd
, union mc_target
*target
)
4705 struct page
*page
= NULL
;
4706 enum mc_target_type ret
= MC_TARGET_NONE
;
4708 page
= pmd_page(pmd
);
4709 VM_BUG_ON_PAGE(!page
|| !PageHead(page
), page
);
4710 if (!(mc
.flags
& MOVE_ANON
))
4712 if (page
->mem_cgroup
== mc
.from
) {
4713 ret
= MC_TARGET_PAGE
;
4716 target
->page
= page
;
4722 static inline enum mc_target_type
get_mctgt_type_thp(struct vm_area_struct
*vma
,
4723 unsigned long addr
, pmd_t pmd
, union mc_target
*target
)
4725 return MC_TARGET_NONE
;
4729 static int mem_cgroup_count_precharge_pte_range(pmd_t
*pmd
,
4730 unsigned long addr
, unsigned long end
,
4731 struct mm_walk
*walk
)
4733 struct vm_area_struct
*vma
= walk
->vma
;
4737 if (pmd_trans_huge_lock(pmd
, vma
, &ptl
) == 1) {
4738 if (get_mctgt_type_thp(vma
, addr
, *pmd
, NULL
) == MC_TARGET_PAGE
)
4739 mc
.precharge
+= HPAGE_PMD_NR
;
4744 if (pmd_trans_unstable(pmd
))
4746 pte
= pte_offset_map_lock(vma
->vm_mm
, pmd
, addr
, &ptl
);
4747 for (; addr
!= end
; pte
++, addr
+= PAGE_SIZE
)
4748 if (get_mctgt_type(vma
, addr
, *pte
, NULL
))
4749 mc
.precharge
++; /* increment precharge temporarily */
4750 pte_unmap_unlock(pte
- 1, ptl
);
4756 static unsigned long mem_cgroup_count_precharge(struct mm_struct
*mm
)
4758 unsigned long precharge
;
4760 struct mm_walk mem_cgroup_count_precharge_walk
= {
4761 .pmd_entry
= mem_cgroup_count_precharge_pte_range
,
4764 down_read(&mm
->mmap_sem
);
4765 walk_page_range(0, ~0UL, &mem_cgroup_count_precharge_walk
);
4766 up_read(&mm
->mmap_sem
);
4768 precharge
= mc
.precharge
;
4774 static int mem_cgroup_precharge_mc(struct mm_struct
*mm
)
4776 unsigned long precharge
= mem_cgroup_count_precharge(mm
);
4778 VM_BUG_ON(mc
.moving_task
);
4779 mc
.moving_task
= current
;
4780 return mem_cgroup_do_precharge(precharge
);
4783 /* cancels all extra charges on mc.from and mc.to, and wakes up all waiters. */
4784 static void __mem_cgroup_clear_mc(void)
4786 struct mem_cgroup
*from
= mc
.from
;
4787 struct mem_cgroup
*to
= mc
.to
;
4789 /* we must uncharge all the leftover precharges from mc.to */
4791 cancel_charge(mc
.to
, mc
.precharge
);
4795 * we didn't uncharge from mc.from at mem_cgroup_move_account(), so
4796 * we must uncharge here.
4798 if (mc
.moved_charge
) {
4799 cancel_charge(mc
.from
, mc
.moved_charge
);
4800 mc
.moved_charge
= 0;
4802 /* we must fixup refcnts and charges */
4803 if (mc
.moved_swap
) {
4804 /* uncharge swap account from the old cgroup */
4805 if (!mem_cgroup_is_root(mc
.from
))
4806 page_counter_uncharge(&mc
.from
->memsw
, mc
.moved_swap
);
4809 * we charged both to->memory and to->memsw, so we
4810 * should uncharge to->memory.
4812 if (!mem_cgroup_is_root(mc
.to
))
4813 page_counter_uncharge(&mc
.to
->memory
, mc
.moved_swap
);
4815 css_put_many(&mc
.from
->css
, mc
.moved_swap
);
4817 /* we've already done css_get(mc.to) */
4820 memcg_oom_recover(from
);
4821 memcg_oom_recover(to
);
4822 wake_up_all(&mc
.waitq
);
4825 static void mem_cgroup_clear_mc(void)
4828 * we must clear moving_task before waking up waiters at the end of
4831 mc
.moving_task
= NULL
;
4832 __mem_cgroup_clear_mc();
4833 spin_lock(&mc
.lock
);
4836 spin_unlock(&mc
.lock
);
4839 static int mem_cgroup_can_attach(struct cgroup_subsys_state
*css
,
4840 struct cgroup_taskset
*tset
)
4842 struct mem_cgroup
*memcg
= mem_cgroup_from_css(css
);
4843 struct mem_cgroup
*from
;
4844 struct task_struct
*p
;
4845 struct mm_struct
*mm
;
4846 unsigned long move_flags
;
4850 * We are now commited to this value whatever it is. Changes in this
4851 * tunable will only affect upcoming migrations, not the current one.
4852 * So we need to save it, and keep it going.
4854 move_flags
= READ_ONCE(memcg
->move_charge_at_immigrate
);
4858 p
= cgroup_taskset_first(tset
);
4859 from
= mem_cgroup_from_task(p
);
4861 VM_BUG_ON(from
== memcg
);
4863 mm
= get_task_mm(p
);
4866 /* We move charges only when we move a owner of the mm */
4867 if (mm
->owner
== p
) {
4870 VM_BUG_ON(mc
.precharge
);
4871 VM_BUG_ON(mc
.moved_charge
);
4872 VM_BUG_ON(mc
.moved_swap
);
4874 spin_lock(&mc
.lock
);
4877 mc
.flags
= move_flags
;
4878 spin_unlock(&mc
.lock
);
4879 /* We set mc.moving_task later */
4881 ret
= mem_cgroup_precharge_mc(mm
);
4883 mem_cgroup_clear_mc();
4889 static void mem_cgroup_cancel_attach(struct cgroup_subsys_state
*css
,
4890 struct cgroup_taskset
*tset
)
4893 mem_cgroup_clear_mc();
4896 static int mem_cgroup_move_charge_pte_range(pmd_t
*pmd
,
4897 unsigned long addr
, unsigned long end
,
4898 struct mm_walk
*walk
)
4901 struct vm_area_struct
*vma
= walk
->vma
;
4904 enum mc_target_type target_type
;
4905 union mc_target target
;
4909 * We don't take compound_lock() here but no race with splitting thp
4911 * - if pmd_trans_huge_lock() returns 1, the relevant thp is not
4912 * under splitting, which means there's no concurrent thp split,
4913 * - if another thread runs into split_huge_page() just after we
4914 * entered this if-block, the thread must wait for page table lock
4915 * to be unlocked in __split_huge_page_splitting(), where the main
4916 * part of thp split is not executed yet.
4918 if (pmd_trans_huge_lock(pmd
, vma
, &ptl
) == 1) {
4919 if (mc
.precharge
< HPAGE_PMD_NR
) {
4923 target_type
= get_mctgt_type_thp(vma
, addr
, *pmd
, &target
);
4924 if (target_type
== MC_TARGET_PAGE
) {
4926 if (!isolate_lru_page(page
)) {
4927 if (!mem_cgroup_move_account(page
, HPAGE_PMD_NR
,
4929 mc
.precharge
-= HPAGE_PMD_NR
;
4930 mc
.moved_charge
+= HPAGE_PMD_NR
;
4932 putback_lru_page(page
);
4940 if (pmd_trans_unstable(pmd
))
4943 pte
= pte_offset_map_lock(vma
->vm_mm
, pmd
, addr
, &ptl
);
4944 for (; addr
!= end
; addr
+= PAGE_SIZE
) {
4945 pte_t ptent
= *(pte
++);
4951 switch (get_mctgt_type(vma
, addr
, ptent
, &target
)) {
4952 case MC_TARGET_PAGE
:
4954 if (isolate_lru_page(page
))
4956 if (!mem_cgroup_move_account(page
, 1, mc
.from
, mc
.to
)) {
4958 /* we uncharge from mc.from later. */
4961 putback_lru_page(page
);
4962 put
: /* get_mctgt_type() gets the page */
4965 case MC_TARGET_SWAP
:
4967 if (!mem_cgroup_move_swap_account(ent
, mc
.from
, mc
.to
)) {
4969 /* we fixup refcnts and charges later. */
4977 pte_unmap_unlock(pte
- 1, ptl
);
4982 * We have consumed all precharges we got in can_attach().
4983 * We try charge one by one, but don't do any additional
4984 * charges to mc.to if we have failed in charge once in attach()
4987 ret
= mem_cgroup_do_precharge(1);
4995 static void mem_cgroup_move_charge(struct mm_struct
*mm
)
4997 struct mm_walk mem_cgroup_move_charge_walk
= {
4998 .pmd_entry
= mem_cgroup_move_charge_pte_range
,
5002 lru_add_drain_all();
5004 * Signal mem_cgroup_begin_page_stat() to take the memcg's
5005 * move_lock while we're moving its pages to another memcg.
5006 * Then wait for already started RCU-only updates to finish.
5008 atomic_inc(&mc
.from
->moving_account
);
5011 if (unlikely(!down_read_trylock(&mm
->mmap_sem
))) {
5013 * Someone who are holding the mmap_sem might be waiting in
5014 * waitq. So we cancel all extra charges, wake up all waiters,
5015 * and retry. Because we cancel precharges, we might not be able
5016 * to move enough charges, but moving charge is a best-effort
5017 * feature anyway, so it wouldn't be a big problem.
5019 __mem_cgroup_clear_mc();
5024 * When we have consumed all precharges and failed in doing
5025 * additional charge, the page walk just aborts.
5027 walk_page_range(0, ~0UL, &mem_cgroup_move_charge_walk
);
5028 up_read(&mm
->mmap_sem
);
5029 atomic_dec(&mc
.from
->moving_account
);
5032 static void mem_cgroup_move_task(struct cgroup_subsys_state
*css
,
5033 struct cgroup_taskset
*tset
)
5035 struct task_struct
*p
= cgroup_taskset_first(tset
);
5036 struct mm_struct
*mm
= get_task_mm(p
);
5040 mem_cgroup_move_charge(mm
);
5044 mem_cgroup_clear_mc();
5046 #else /* !CONFIG_MMU */
5047 static int mem_cgroup_can_attach(struct cgroup_subsys_state
*css
,
5048 struct cgroup_taskset
*tset
)
5052 static void mem_cgroup_cancel_attach(struct cgroup_subsys_state
*css
,
5053 struct cgroup_taskset
*tset
)
5056 static void mem_cgroup_move_task(struct cgroup_subsys_state
*css
,
5057 struct cgroup_taskset
*tset
)
5063 * Cgroup retains root cgroups across [un]mount cycles making it necessary
5064 * to verify whether we're attached to the default hierarchy on each mount
5067 static void mem_cgroup_bind(struct cgroup_subsys_state
*root_css
)
5070 * use_hierarchy is forced on the default hierarchy. cgroup core
5071 * guarantees that @root doesn't have any children, so turning it
5072 * on for the root memcg is enough.
5074 if (cgroup_on_dfl(root_css
->cgroup
))
5075 root_mem_cgroup
->use_hierarchy
= true;
5077 root_mem_cgroup
->use_hierarchy
= false;
5080 static u64
memory_current_read(struct cgroup_subsys_state
*css
,
5083 return mem_cgroup_usage(mem_cgroup_from_css(css
), false);
5086 static int memory_low_show(struct seq_file
*m
, void *v
)
5088 struct mem_cgroup
*memcg
= mem_cgroup_from_css(seq_css(m
));
5089 unsigned long low
= READ_ONCE(memcg
->low
);
5091 if (low
== PAGE_COUNTER_MAX
)
5092 seq_puts(m
, "max\n");
5094 seq_printf(m
, "%llu\n", (u64
)low
* PAGE_SIZE
);
5099 static ssize_t
memory_low_write(struct kernfs_open_file
*of
,
5100 char *buf
, size_t nbytes
, loff_t off
)
5102 struct mem_cgroup
*memcg
= mem_cgroup_from_css(of_css(of
));
5106 buf
= strstrip(buf
);
5107 err
= page_counter_memparse(buf
, "max", &low
);
5116 static int memory_high_show(struct seq_file
*m
, void *v
)
5118 struct mem_cgroup
*memcg
= mem_cgroup_from_css(seq_css(m
));
5119 unsigned long high
= READ_ONCE(memcg
->high
);
5121 if (high
== PAGE_COUNTER_MAX
)
5122 seq_puts(m
, "max\n");
5124 seq_printf(m
, "%llu\n", (u64
)high
* PAGE_SIZE
);
5129 static ssize_t
memory_high_write(struct kernfs_open_file
*of
,
5130 char *buf
, size_t nbytes
, loff_t off
)
5132 struct mem_cgroup
*memcg
= mem_cgroup_from_css(of_css(of
));
5136 buf
= strstrip(buf
);
5137 err
= page_counter_memparse(buf
, "max", &high
);
5143 memcg_wb_domain_size_changed(memcg
);
5147 static int memory_max_show(struct seq_file
*m
, void *v
)
5149 struct mem_cgroup
*memcg
= mem_cgroup_from_css(seq_css(m
));
5150 unsigned long max
= READ_ONCE(memcg
->memory
.limit
);
5152 if (max
== PAGE_COUNTER_MAX
)
5153 seq_puts(m
, "max\n");
5155 seq_printf(m
, "%llu\n", (u64
)max
* PAGE_SIZE
);
5160 static ssize_t
memory_max_write(struct kernfs_open_file
*of
,
5161 char *buf
, size_t nbytes
, loff_t off
)
5163 struct mem_cgroup
*memcg
= mem_cgroup_from_css(of_css(of
));
5167 buf
= strstrip(buf
);
5168 err
= page_counter_memparse(buf
, "max", &max
);
5172 err
= mem_cgroup_resize_limit(memcg
, max
);
5176 memcg_wb_domain_size_changed(memcg
);
5180 static int memory_events_show(struct seq_file
*m
, void *v
)
5182 struct mem_cgroup
*memcg
= mem_cgroup_from_css(seq_css(m
));
5184 seq_printf(m
, "low %lu\n", mem_cgroup_read_events(memcg
, MEMCG_LOW
));
5185 seq_printf(m
, "high %lu\n", mem_cgroup_read_events(memcg
, MEMCG_HIGH
));
5186 seq_printf(m
, "max %lu\n", mem_cgroup_read_events(memcg
, MEMCG_MAX
));
5187 seq_printf(m
, "oom %lu\n", mem_cgroup_read_events(memcg
, MEMCG_OOM
));
5192 static struct cftype memory_files
[] = {
5195 .read_u64
= memory_current_read
,
5199 .flags
= CFTYPE_NOT_ON_ROOT
,
5200 .seq_show
= memory_low_show
,
5201 .write
= memory_low_write
,
5205 .flags
= CFTYPE_NOT_ON_ROOT
,
5206 .seq_show
= memory_high_show
,
5207 .write
= memory_high_write
,
5211 .flags
= CFTYPE_NOT_ON_ROOT
,
5212 .seq_show
= memory_max_show
,
5213 .write
= memory_max_write
,
5217 .flags
= CFTYPE_NOT_ON_ROOT
,
5218 .seq_show
= memory_events_show
,
5223 struct cgroup_subsys memory_cgrp_subsys
= {
5224 .css_alloc
= mem_cgroup_css_alloc
,
5225 .css_online
= mem_cgroup_css_online
,
5226 .css_offline
= mem_cgroup_css_offline
,
5227 .css_free
= mem_cgroup_css_free
,
5228 .css_reset
= mem_cgroup_css_reset
,
5229 .can_attach
= mem_cgroup_can_attach
,
5230 .cancel_attach
= mem_cgroup_cancel_attach
,
5231 .attach
= mem_cgroup_move_task
,
5232 .bind
= mem_cgroup_bind
,
5233 .dfl_cftypes
= memory_files
,
5234 .legacy_cftypes
= mem_cgroup_legacy_files
,
5239 * mem_cgroup_low - check if memory consumption is below the normal range
5240 * @root: the highest ancestor to consider
5241 * @memcg: the memory cgroup to check
5243 * Returns %true if memory consumption of @memcg, and that of all
5244 * configurable ancestors up to @root, is below the normal range.
5246 bool mem_cgroup_low(struct mem_cgroup
*root
, struct mem_cgroup
*memcg
)
5248 if (mem_cgroup_disabled())
5252 * The toplevel group doesn't have a configurable range, so
5253 * it's never low when looked at directly, and it is not
5254 * considered an ancestor when assessing the hierarchy.
5257 if (memcg
== root_mem_cgroup
)
5260 if (page_counter_read(&memcg
->memory
) >= memcg
->low
)
5263 while (memcg
!= root
) {
5264 memcg
= parent_mem_cgroup(memcg
);
5266 if (memcg
== root_mem_cgroup
)
5269 if (page_counter_read(&memcg
->memory
) >= memcg
->low
)
5276 * mem_cgroup_try_charge - try charging a page
5277 * @page: page to charge
5278 * @mm: mm context of the victim
5279 * @gfp_mask: reclaim mode
5280 * @memcgp: charged memcg return
5282 * Try to charge @page to the memcg that @mm belongs to, reclaiming
5283 * pages according to @gfp_mask if necessary.
5285 * Returns 0 on success, with *@memcgp pointing to the charged memcg.
5286 * Otherwise, an error code is returned.
5288 * After page->mapping has been set up, the caller must finalize the
5289 * charge with mem_cgroup_commit_charge(). Or abort the transaction
5290 * with mem_cgroup_cancel_charge() in case page instantiation fails.
5292 int mem_cgroup_try_charge(struct page
*page
, struct mm_struct
*mm
,
5293 gfp_t gfp_mask
, struct mem_cgroup
**memcgp
)
5295 struct mem_cgroup
*memcg
= NULL
;
5296 unsigned int nr_pages
= 1;
5299 if (mem_cgroup_disabled())
5302 if (PageSwapCache(page
)) {
5304 * Every swap fault against a single page tries to charge the
5305 * page, bail as early as possible. shmem_unuse() encounters
5306 * already charged pages, too. The USED bit is protected by
5307 * the page lock, which serializes swap cache removal, which
5308 * in turn serializes uncharging.
5310 VM_BUG_ON_PAGE(!PageLocked(page
), page
);
5311 if (page
->mem_cgroup
)
5314 if (do_swap_account
) {
5315 swp_entry_t ent
= { .val
= page_private(page
), };
5316 unsigned short id
= lookup_swap_cgroup_id(ent
);
5319 memcg
= mem_cgroup_from_id(id
);
5320 if (memcg
&& !css_tryget_online(&memcg
->css
))
5326 if (PageTransHuge(page
)) {
5327 nr_pages
<<= compound_order(page
);
5328 VM_BUG_ON_PAGE(!PageTransHuge(page
), page
);
5332 memcg
= get_mem_cgroup_from_mm(mm
);
5334 ret
= try_charge(memcg
, gfp_mask
, nr_pages
);
5336 css_put(&memcg
->css
);
5343 * mem_cgroup_commit_charge - commit a page charge
5344 * @page: page to charge
5345 * @memcg: memcg to charge the page to
5346 * @lrucare: page might be on LRU already
5348 * Finalize a charge transaction started by mem_cgroup_try_charge(),
5349 * after page->mapping has been set up. This must happen atomically
5350 * as part of the page instantiation, i.e. under the page table lock
5351 * for anonymous pages, under the page lock for page and swap cache.
5353 * In addition, the page must not be on the LRU during the commit, to
5354 * prevent racing with task migration. If it might be, use @lrucare.
5356 * Use mem_cgroup_cancel_charge() to cancel the transaction instead.
5358 void mem_cgroup_commit_charge(struct page
*page
, struct mem_cgroup
*memcg
,
5361 unsigned int nr_pages
= 1;
5363 VM_BUG_ON_PAGE(!page
->mapping
, page
);
5364 VM_BUG_ON_PAGE(PageLRU(page
) && !lrucare
, page
);
5366 if (mem_cgroup_disabled())
5369 * Swap faults will attempt to charge the same page multiple
5370 * times. But reuse_swap_page() might have removed the page
5371 * from swapcache already, so we can't check PageSwapCache().
5376 commit_charge(page
, memcg
, lrucare
);
5378 if (PageTransHuge(page
)) {
5379 nr_pages
<<= compound_order(page
);
5380 VM_BUG_ON_PAGE(!PageTransHuge(page
), page
);
5383 local_irq_disable();
5384 mem_cgroup_charge_statistics(memcg
, page
, nr_pages
);
5385 memcg_check_events(memcg
, page
);
5388 if (do_swap_account
&& PageSwapCache(page
)) {
5389 swp_entry_t entry
= { .val
= page_private(page
) };
5391 * The swap entry might not get freed for a long time,
5392 * let's not wait for it. The page already received a
5393 * memory+swap charge, drop the swap entry duplicate.
5395 mem_cgroup_uncharge_swap(entry
);
5400 * mem_cgroup_cancel_charge - cancel a page charge
5401 * @page: page to charge
5402 * @memcg: memcg to charge the page to
5404 * Cancel a charge transaction started by mem_cgroup_try_charge().
5406 void mem_cgroup_cancel_charge(struct page
*page
, struct mem_cgroup
*memcg
)
5408 unsigned int nr_pages
= 1;
5410 if (mem_cgroup_disabled())
5413 * Swap faults will attempt to charge the same page multiple
5414 * times. But reuse_swap_page() might have removed the page
5415 * from swapcache already, so we can't check PageSwapCache().
5420 if (PageTransHuge(page
)) {
5421 nr_pages
<<= compound_order(page
);
5422 VM_BUG_ON_PAGE(!PageTransHuge(page
), page
);
5425 cancel_charge(memcg
, nr_pages
);
5428 static void uncharge_batch(struct mem_cgroup
*memcg
, unsigned long pgpgout
,
5429 unsigned long nr_anon
, unsigned long nr_file
,
5430 unsigned long nr_huge
, struct page
*dummy_page
)
5432 unsigned long nr_pages
= nr_anon
+ nr_file
;
5433 unsigned long flags
;
5435 if (!mem_cgroup_is_root(memcg
)) {
5436 page_counter_uncharge(&memcg
->memory
, nr_pages
);
5437 if (do_swap_account
)
5438 page_counter_uncharge(&memcg
->memsw
, nr_pages
);
5439 memcg_oom_recover(memcg
);
5442 local_irq_save(flags
);
5443 __this_cpu_sub(memcg
->stat
->count
[MEM_CGROUP_STAT_RSS
], nr_anon
);
5444 __this_cpu_sub(memcg
->stat
->count
[MEM_CGROUP_STAT_CACHE
], nr_file
);
5445 __this_cpu_sub(memcg
->stat
->count
[MEM_CGROUP_STAT_RSS_HUGE
], nr_huge
);
5446 __this_cpu_add(memcg
->stat
->events
[MEM_CGROUP_EVENTS_PGPGOUT
], pgpgout
);
5447 __this_cpu_add(memcg
->stat
->nr_page_events
, nr_pages
);
5448 memcg_check_events(memcg
, dummy_page
);
5449 local_irq_restore(flags
);
5451 if (!mem_cgroup_is_root(memcg
))
5452 css_put_many(&memcg
->css
, nr_pages
);
5455 static void uncharge_list(struct list_head
*page_list
)
5457 struct mem_cgroup
*memcg
= NULL
;
5458 unsigned long nr_anon
= 0;
5459 unsigned long nr_file
= 0;
5460 unsigned long nr_huge
= 0;
5461 unsigned long pgpgout
= 0;
5462 struct list_head
*next
;
5465 next
= page_list
->next
;
5467 unsigned int nr_pages
= 1;
5469 page
= list_entry(next
, struct page
, lru
);
5470 next
= page
->lru
.next
;
5472 VM_BUG_ON_PAGE(PageLRU(page
), page
);
5473 VM_BUG_ON_PAGE(page_count(page
), page
);
5475 if (!page
->mem_cgroup
)
5479 * Nobody should be changing or seriously looking at
5480 * page->mem_cgroup at this point, we have fully
5481 * exclusive access to the page.
5484 if (memcg
!= page
->mem_cgroup
) {
5486 uncharge_batch(memcg
, pgpgout
, nr_anon
, nr_file
,
5488 pgpgout
= nr_anon
= nr_file
= nr_huge
= 0;
5490 memcg
= page
->mem_cgroup
;
5493 if (PageTransHuge(page
)) {
5494 nr_pages
<<= compound_order(page
);
5495 VM_BUG_ON_PAGE(!PageTransHuge(page
), page
);
5496 nr_huge
+= nr_pages
;
5500 nr_anon
+= nr_pages
;
5502 nr_file
+= nr_pages
;
5504 page
->mem_cgroup
= NULL
;
5507 } while (next
!= page_list
);
5510 uncharge_batch(memcg
, pgpgout
, nr_anon
, nr_file
,
5515 * mem_cgroup_uncharge - uncharge a page
5516 * @page: page to uncharge
5518 * Uncharge a page previously charged with mem_cgroup_try_charge() and
5519 * mem_cgroup_commit_charge().
5521 void mem_cgroup_uncharge(struct page
*page
)
5523 if (mem_cgroup_disabled())
5526 /* Don't touch page->lru of any random page, pre-check: */
5527 if (!page
->mem_cgroup
)
5530 INIT_LIST_HEAD(&page
->lru
);
5531 uncharge_list(&page
->lru
);
5535 * mem_cgroup_uncharge_list - uncharge a list of page
5536 * @page_list: list of pages to uncharge
5538 * Uncharge a list of pages previously charged with
5539 * mem_cgroup_try_charge() and mem_cgroup_commit_charge().
5541 void mem_cgroup_uncharge_list(struct list_head
*page_list
)
5543 if (mem_cgroup_disabled())
5546 if (!list_empty(page_list
))
5547 uncharge_list(page_list
);
5551 * mem_cgroup_migrate - migrate a charge to another page
5552 * @oldpage: currently charged page
5553 * @newpage: page to transfer the charge to
5554 * @lrucare: either or both pages might be on the LRU already
5556 * Migrate the charge from @oldpage to @newpage.
5558 * Both pages must be locked, @newpage->mapping must be set up.
5560 void mem_cgroup_migrate(struct page
*oldpage
, struct page
*newpage
,
5563 struct mem_cgroup
*memcg
;
5566 VM_BUG_ON_PAGE(!PageLocked(oldpage
), oldpage
);
5567 VM_BUG_ON_PAGE(!PageLocked(newpage
), newpage
);
5568 VM_BUG_ON_PAGE(!lrucare
&& PageLRU(oldpage
), oldpage
);
5569 VM_BUG_ON_PAGE(!lrucare
&& PageLRU(newpage
), newpage
);
5570 VM_BUG_ON_PAGE(PageAnon(oldpage
) != PageAnon(newpage
), newpage
);
5571 VM_BUG_ON_PAGE(PageTransHuge(oldpage
) != PageTransHuge(newpage
),
5574 if (mem_cgroup_disabled())
5577 /* Page cache replacement: new page already charged? */
5578 if (newpage
->mem_cgroup
)
5582 * Swapcache readahead pages can get migrated before being
5583 * charged, and migration from compaction can happen to an
5584 * uncharged page when the PFN walker finds a page that
5585 * reclaim just put back on the LRU but has not released yet.
5587 memcg
= oldpage
->mem_cgroup
;
5592 lock_page_lru(oldpage
, &isolated
);
5594 oldpage
->mem_cgroup
= NULL
;
5597 unlock_page_lru(oldpage
, isolated
);
5599 commit_charge(newpage
, memcg
, lrucare
);
5603 * subsys_initcall() for memory controller.
5605 * Some parts like hotcpu_notifier() have to be initialized from this context
5606 * because of lock dependencies (cgroup_lock -> cpu hotplug) but basically
5607 * everything that doesn't depend on a specific mem_cgroup structure should
5608 * be initialized from here.
5610 static int __init
mem_cgroup_init(void)
5614 hotcpu_notifier(memcg_cpu_hotplug_callback
, 0);
5616 for_each_possible_cpu(cpu
)
5617 INIT_WORK(&per_cpu_ptr(&memcg_stock
, cpu
)->work
,
5620 for_each_node(node
) {
5621 struct mem_cgroup_tree_per_node
*rtpn
;
5624 rtpn
= kzalloc_node(sizeof(*rtpn
), GFP_KERNEL
,
5625 node_online(node
) ? node
: NUMA_NO_NODE
);
5627 for (zone
= 0; zone
< MAX_NR_ZONES
; zone
++) {
5628 struct mem_cgroup_tree_per_zone
*rtpz
;
5630 rtpz
= &rtpn
->rb_tree_per_zone
[zone
];
5631 rtpz
->rb_root
= RB_ROOT
;
5632 spin_lock_init(&rtpz
->lock
);
5634 soft_limit_tree
.rb_tree_per_node
[node
] = rtpn
;
5639 subsys_initcall(mem_cgroup_init
);
5641 #ifdef CONFIG_MEMCG_SWAP
5643 * mem_cgroup_swapout - transfer a memsw charge to swap
5644 * @page: page whose memsw charge to transfer
5645 * @entry: swap entry to move the charge to
5647 * Transfer the memsw charge of @page to @entry.
5649 void mem_cgroup_swapout(struct page
*page
, swp_entry_t entry
)
5651 struct mem_cgroup
*memcg
;
5652 unsigned short oldid
;
5654 VM_BUG_ON_PAGE(PageLRU(page
), page
);
5655 VM_BUG_ON_PAGE(page_count(page
), page
);
5657 if (!do_swap_account
)
5660 memcg
= page
->mem_cgroup
;
5662 /* Readahead page, never charged */
5666 oldid
= swap_cgroup_record(entry
, mem_cgroup_id(memcg
));
5667 VM_BUG_ON_PAGE(oldid
, page
);
5668 mem_cgroup_swap_statistics(memcg
, true);
5670 page
->mem_cgroup
= NULL
;
5672 if (!mem_cgroup_is_root(memcg
))
5673 page_counter_uncharge(&memcg
->memory
, 1);
5676 * Interrupts should be disabled here because the caller holds the
5677 * mapping->tree_lock lock which is taken with interrupts-off. It is
5678 * important here to have the interrupts disabled because it is the
5679 * only synchronisation we have for udpating the per-CPU variables.
5681 VM_BUG_ON(!irqs_disabled());
5682 mem_cgroup_charge_statistics(memcg
, page
, -1);
5683 memcg_check_events(memcg
, page
);
5687 * mem_cgroup_uncharge_swap - uncharge a swap entry
5688 * @entry: swap entry to uncharge
5690 * Drop the memsw charge associated with @entry.
5692 void mem_cgroup_uncharge_swap(swp_entry_t entry
)
5694 struct mem_cgroup
*memcg
;
5697 if (!do_swap_account
)
5700 id
= swap_cgroup_record(entry
, 0);
5702 memcg
= mem_cgroup_from_id(id
);
5704 if (!mem_cgroup_is_root(memcg
))
5705 page_counter_uncharge(&memcg
->memsw
, 1);
5706 mem_cgroup_swap_statistics(memcg
, false);
5707 css_put(&memcg
->css
);
5712 /* for remember boot option*/
5713 #ifdef CONFIG_MEMCG_SWAP_ENABLED
5714 static int really_do_swap_account __initdata
= 1;
5716 static int really_do_swap_account __initdata
;
5719 static int __init
enable_swap_account(char *s
)
5721 if (!strcmp(s
, "1"))
5722 really_do_swap_account
= 1;
5723 else if (!strcmp(s
, "0"))
5724 really_do_swap_account
= 0;
5727 __setup("swapaccount=", enable_swap_account
);
5729 static struct cftype memsw_cgroup_files
[] = {
5731 .name
= "memsw.usage_in_bytes",
5732 .private = MEMFILE_PRIVATE(_MEMSWAP
, RES_USAGE
),
5733 .read_u64
= mem_cgroup_read_u64
,
5736 .name
= "memsw.max_usage_in_bytes",
5737 .private = MEMFILE_PRIVATE(_MEMSWAP
, RES_MAX_USAGE
),
5738 .write
= mem_cgroup_reset
,
5739 .read_u64
= mem_cgroup_read_u64
,
5742 .name
= "memsw.limit_in_bytes",
5743 .private = MEMFILE_PRIVATE(_MEMSWAP
, RES_LIMIT
),
5744 .write
= mem_cgroup_write
,
5745 .read_u64
= mem_cgroup_read_u64
,
5748 .name
= "memsw.failcnt",
5749 .private = MEMFILE_PRIVATE(_MEMSWAP
, RES_FAILCNT
),
5750 .write
= mem_cgroup_reset
,
5751 .read_u64
= mem_cgroup_read_u64
,
5753 { }, /* terminate */
5756 static int __init
mem_cgroup_swap_init(void)
5758 if (!mem_cgroup_disabled() && really_do_swap_account
) {
5759 do_swap_account
= 1;
5760 WARN_ON(cgroup_add_legacy_cftypes(&memory_cgrp_subsys
,
5761 memsw_cgroup_files
));
5765 subsys_initcall(mem_cgroup_swap_init
);
5767 #endif /* CONFIG_MEMCG_SWAP */