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 * This program is free software; you can redistribute it and/or modify
14 * it under the terms of the GNU General Public License as published by
15 * the Free Software Foundation; either version 2 of the License, or
16 * (at your option) any later version.
18 * This program is distributed in the hope that it will be useful,
19 * but WITHOUT ANY WARRANTY; without even the implied warranty of
20 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
21 * GNU General Public License for more details.
24 #include <linux/res_counter.h>
25 #include <linux/memcontrol.h>
26 #include <linux/cgroup.h>
28 #include <linux/hugetlb.h>
29 #include <linux/pagemap.h>
30 #include <linux/smp.h>
31 #include <linux/page-flags.h>
32 #include <linux/backing-dev.h>
33 #include <linux/bit_spinlock.h>
34 #include <linux/rcupdate.h>
35 #include <linux/limits.h>
36 #include <linux/export.h>
37 #include <linux/mutex.h>
38 #include <linux/rbtree.h>
39 #include <linux/slab.h>
40 #include <linux/swap.h>
41 #include <linux/swapops.h>
42 #include <linux/spinlock.h>
43 #include <linux/eventfd.h>
44 #include <linux/sort.h>
46 #include <linux/seq_file.h>
47 #include <linux/vmalloc.h>
48 #include <linux/mm_inline.h>
49 #include <linux/page_cgroup.h>
50 #include <linux/cpu.h>
51 #include <linux/oom.h>
54 #include <net/tcp_memcontrol.h>
56 #include <asm/uaccess.h>
58 #include <trace/events/vmscan.h>
60 struct cgroup_subsys mem_cgroup_subsys __read_mostly
;
61 #define MEM_CGROUP_RECLAIM_RETRIES 5
62 static struct mem_cgroup
*root_mem_cgroup __read_mostly
;
64 #ifdef CONFIG_MEMCG_SWAP
65 /* Turned on only when memory cgroup is enabled && really_do_swap_account = 1 */
66 int do_swap_account __read_mostly
;
68 /* for remember boot option*/
69 #ifdef CONFIG_MEMCG_SWAP_ENABLED
70 static int really_do_swap_account __initdata
= 1;
72 static int really_do_swap_account __initdata
= 0;
76 #define do_swap_account 0
81 * Statistics for memory cgroup.
83 enum mem_cgroup_stat_index
{
85 * For MEM_CONTAINER_TYPE_ALL, usage = pagecache + rss.
87 MEM_CGROUP_STAT_CACHE
, /* # of pages charged as cache */
88 MEM_CGROUP_STAT_RSS
, /* # of pages charged as anon rss */
89 MEM_CGROUP_STAT_FILE_MAPPED
, /* # of pages charged as file rss */
90 MEM_CGROUP_STAT_SWAP
, /* # of pages, swapped out */
91 MEM_CGROUP_STAT_NSTATS
,
94 static const char * const mem_cgroup_stat_names
[] = {
101 enum mem_cgroup_events_index
{
102 MEM_CGROUP_EVENTS_PGPGIN
, /* # of pages paged in */
103 MEM_CGROUP_EVENTS_PGPGOUT
, /* # of pages paged out */
104 MEM_CGROUP_EVENTS_PGFAULT
, /* # of page-faults */
105 MEM_CGROUP_EVENTS_PGMAJFAULT
, /* # of major page-faults */
106 MEM_CGROUP_EVENTS_NSTATS
,
109 static const char * const mem_cgroup_events_names
[] = {
117 * Per memcg event counter is incremented at every pagein/pageout. With THP,
118 * it will be incremated by the number of pages. This counter is used for
119 * for trigger some periodic events. This is straightforward and better
120 * than using jiffies etc. to handle periodic memcg event.
122 enum mem_cgroup_events_target
{
123 MEM_CGROUP_TARGET_THRESH
,
124 MEM_CGROUP_TARGET_SOFTLIMIT
,
125 MEM_CGROUP_TARGET_NUMAINFO
,
128 #define THRESHOLDS_EVENTS_TARGET 128
129 #define SOFTLIMIT_EVENTS_TARGET 1024
130 #define NUMAINFO_EVENTS_TARGET 1024
132 struct mem_cgroup_stat_cpu
{
133 long count
[MEM_CGROUP_STAT_NSTATS
];
134 unsigned long events
[MEM_CGROUP_EVENTS_NSTATS
];
135 unsigned long nr_page_events
;
136 unsigned long targets
[MEM_CGROUP_NTARGETS
];
139 struct mem_cgroup_reclaim_iter
{
140 /* css_id of the last scanned hierarchy member */
142 /* scan generation, increased every round-trip */
143 unsigned int generation
;
147 * per-zone information in memory controller.
149 struct mem_cgroup_per_zone
{
150 struct lruvec lruvec
;
151 unsigned long lru_size
[NR_LRU_LISTS
];
153 struct mem_cgroup_reclaim_iter reclaim_iter
[DEF_PRIORITY
+ 1];
155 struct rb_node tree_node
; /* RB tree node */
156 unsigned long long usage_in_excess
;/* Set to the value by which */
157 /* the soft limit is exceeded*/
159 struct mem_cgroup
*memcg
; /* Back pointer, we cannot */
160 /* use container_of */
163 struct mem_cgroup_per_node
{
164 struct mem_cgroup_per_zone zoneinfo
[MAX_NR_ZONES
];
167 struct mem_cgroup_lru_info
{
168 struct mem_cgroup_per_node
*nodeinfo
[MAX_NUMNODES
];
172 * Cgroups above their limits are maintained in a RB-Tree, independent of
173 * their hierarchy representation
176 struct mem_cgroup_tree_per_zone
{
177 struct rb_root rb_root
;
181 struct mem_cgroup_tree_per_node
{
182 struct mem_cgroup_tree_per_zone rb_tree_per_zone
[MAX_NR_ZONES
];
185 struct mem_cgroup_tree
{
186 struct mem_cgroup_tree_per_node
*rb_tree_per_node
[MAX_NUMNODES
];
189 static struct mem_cgroup_tree soft_limit_tree __read_mostly
;
191 struct mem_cgroup_threshold
{
192 struct eventfd_ctx
*eventfd
;
197 struct mem_cgroup_threshold_ary
{
198 /* An array index points to threshold just below or equal to usage. */
199 int current_threshold
;
200 /* Size of entries[] */
202 /* Array of thresholds */
203 struct mem_cgroup_threshold entries
[0];
206 struct mem_cgroup_thresholds
{
207 /* Primary thresholds array */
208 struct mem_cgroup_threshold_ary
*primary
;
210 * Spare threshold array.
211 * This is needed to make mem_cgroup_unregister_event() "never fail".
212 * It must be able to store at least primary->size - 1 entries.
214 struct mem_cgroup_threshold_ary
*spare
;
218 struct mem_cgroup_eventfd_list
{
219 struct list_head list
;
220 struct eventfd_ctx
*eventfd
;
223 static void mem_cgroup_threshold(struct mem_cgroup
*memcg
);
224 static void mem_cgroup_oom_notify(struct mem_cgroup
*memcg
);
227 * The memory controller data structure. The memory controller controls both
228 * page cache and RSS per cgroup. We would eventually like to provide
229 * statistics based on the statistics developed by Rik Van Riel for clock-pro,
230 * to help the administrator determine what knobs to tune.
232 * TODO: Add a water mark for the memory controller. Reclaim will begin when
233 * we hit the water mark. May be even add a low water mark, such that
234 * no reclaim occurs from a cgroup at it's low water mark, this is
235 * a feature that will be implemented much later in the future.
238 struct cgroup_subsys_state css
;
240 * the counter to account for memory usage
242 struct res_counter res
;
246 * the counter to account for mem+swap usage.
248 struct res_counter memsw
;
251 * rcu_freeing is used only when freeing struct mem_cgroup,
252 * so put it into a union to avoid wasting more memory.
253 * It must be disjoint from the css field. It could be
254 * in a union with the res field, but res plays a much
255 * larger part in mem_cgroup life than memsw, and might
256 * be of interest, even at time of free, when debugging.
257 * So share rcu_head with the less interesting memsw.
259 struct rcu_head rcu_freeing
;
261 * We also need some space for a worker in deferred freeing.
262 * By the time we call it, rcu_freeing is no longer in use.
264 struct work_struct work_freeing
;
268 * Per cgroup active and inactive list, similar to the
269 * per zone LRU lists.
271 struct mem_cgroup_lru_info info
;
272 int last_scanned_node
;
274 nodemask_t scan_nodes
;
275 atomic_t numainfo_events
;
276 atomic_t numainfo_updating
;
279 * Should the accounting and control be hierarchical, per subtree?
289 /* OOM-Killer disable */
290 int oom_kill_disable
;
292 /* set when res.limit == memsw.limit */
293 bool memsw_is_minimum
;
295 /* protect arrays of thresholds */
296 struct mutex thresholds_lock
;
298 /* thresholds for memory usage. RCU-protected */
299 struct mem_cgroup_thresholds thresholds
;
301 /* thresholds for mem+swap usage. RCU-protected */
302 struct mem_cgroup_thresholds memsw_thresholds
;
304 /* For oom notifier event fd */
305 struct list_head oom_notify
;
308 * Should we move charges of a task when a task is moved into this
309 * mem_cgroup ? And what type of charges should we move ?
311 unsigned long move_charge_at_immigrate
;
313 * set > 0 if pages under this cgroup are moving to other cgroup.
315 atomic_t moving_account
;
316 /* taken only while moving_account > 0 */
317 spinlock_t move_lock
;
321 struct mem_cgroup_stat_cpu __percpu
*stat
;
323 * used when a cpu is offlined or other synchronizations
324 * See mem_cgroup_read_stat().
326 struct mem_cgroup_stat_cpu nocpu_base
;
327 spinlock_t pcp_counter_lock
;
330 struct tcp_memcontrol tcp_mem
;
334 /* Stuffs for move charges at task migration. */
336 * Types of charges to be moved. "move_charge_at_immitgrate" is treated as a
337 * left-shifted bitmap of these types.
340 MOVE_CHARGE_TYPE_ANON
, /* private anonymous page and swap of it */
341 MOVE_CHARGE_TYPE_FILE
, /* file page(including tmpfs) and swap of it */
345 /* "mc" and its members are protected by cgroup_mutex */
346 static struct move_charge_struct
{
347 spinlock_t lock
; /* for from, to */
348 struct mem_cgroup
*from
;
349 struct mem_cgroup
*to
;
350 unsigned long precharge
;
351 unsigned long moved_charge
;
352 unsigned long moved_swap
;
353 struct task_struct
*moving_task
; /* a task moving charges */
354 wait_queue_head_t waitq
; /* a waitq for other context */
356 .lock
= __SPIN_LOCK_UNLOCKED(mc
.lock
),
357 .waitq
= __WAIT_QUEUE_HEAD_INITIALIZER(mc
.waitq
),
360 static bool move_anon(void)
362 return test_bit(MOVE_CHARGE_TYPE_ANON
,
363 &mc
.to
->move_charge_at_immigrate
);
366 static bool move_file(void)
368 return test_bit(MOVE_CHARGE_TYPE_FILE
,
369 &mc
.to
->move_charge_at_immigrate
);
373 * Maximum loops in mem_cgroup_hierarchical_reclaim(), used for soft
374 * limit reclaim to prevent infinite loops, if they ever occur.
376 #define MEM_CGROUP_MAX_RECLAIM_LOOPS 100
377 #define MEM_CGROUP_MAX_SOFT_LIMIT_RECLAIM_LOOPS 2
380 MEM_CGROUP_CHARGE_TYPE_CACHE
= 0,
381 MEM_CGROUP_CHARGE_TYPE_ANON
,
382 MEM_CGROUP_CHARGE_TYPE_SWAPOUT
, /* for accounting swapcache */
383 MEM_CGROUP_CHARGE_TYPE_DROP
, /* a page was unused swap cache */
387 /* for encoding cft->private value on file */
390 #define _OOM_TYPE (2)
391 #define MEMFILE_PRIVATE(x, val) ((x) << 16 | (val))
392 #define MEMFILE_TYPE(val) ((val) >> 16 & 0xffff)
393 #define MEMFILE_ATTR(val) ((val) & 0xffff)
394 /* Used for OOM nofiier */
395 #define OOM_CONTROL (0)
398 * Reclaim flags for mem_cgroup_hierarchical_reclaim
400 #define MEM_CGROUP_RECLAIM_NOSWAP_BIT 0x0
401 #define MEM_CGROUP_RECLAIM_NOSWAP (1 << MEM_CGROUP_RECLAIM_NOSWAP_BIT)
402 #define MEM_CGROUP_RECLAIM_SHRINK_BIT 0x1
403 #define MEM_CGROUP_RECLAIM_SHRINK (1 << MEM_CGROUP_RECLAIM_SHRINK_BIT)
405 static void mem_cgroup_get(struct mem_cgroup
*memcg
);
406 static void mem_cgroup_put(struct mem_cgroup
*memcg
);
409 struct mem_cgroup
*mem_cgroup_from_css(struct cgroup_subsys_state
*s
)
411 return container_of(s
, struct mem_cgroup
, css
);
414 /* Writing them here to avoid exposing memcg's inner layout */
415 #ifdef CONFIG_MEMCG_KMEM
416 #include <net/sock.h>
419 static bool mem_cgroup_is_root(struct mem_cgroup
*memcg
);
420 void sock_update_memcg(struct sock
*sk
)
422 if (mem_cgroup_sockets_enabled
) {
423 struct mem_cgroup
*memcg
;
424 struct cg_proto
*cg_proto
;
426 BUG_ON(!sk
->sk_prot
->proto_cgroup
);
428 /* Socket cloning can throw us here with sk_cgrp already
429 * filled. It won't however, necessarily happen from
430 * process context. So the test for root memcg given
431 * the current task's memcg won't help us in this case.
433 * Respecting the original socket's memcg is a better
434 * decision in this case.
437 BUG_ON(mem_cgroup_is_root(sk
->sk_cgrp
->memcg
));
438 mem_cgroup_get(sk
->sk_cgrp
->memcg
);
443 memcg
= mem_cgroup_from_task(current
);
444 cg_proto
= sk
->sk_prot
->proto_cgroup(memcg
);
445 if (!mem_cgroup_is_root(memcg
) && memcg_proto_active(cg_proto
)) {
446 mem_cgroup_get(memcg
);
447 sk
->sk_cgrp
= cg_proto
;
452 EXPORT_SYMBOL(sock_update_memcg
);
454 void sock_release_memcg(struct sock
*sk
)
456 if (mem_cgroup_sockets_enabled
&& sk
->sk_cgrp
) {
457 struct mem_cgroup
*memcg
;
458 WARN_ON(!sk
->sk_cgrp
->memcg
);
459 memcg
= sk
->sk_cgrp
->memcg
;
460 mem_cgroup_put(memcg
);
465 struct cg_proto
*tcp_proto_cgroup(struct mem_cgroup
*memcg
)
467 if (!memcg
|| mem_cgroup_is_root(memcg
))
470 return &memcg
->tcp_mem
.cg_proto
;
472 EXPORT_SYMBOL(tcp_proto_cgroup
);
473 #endif /* CONFIG_INET */
474 #endif /* CONFIG_MEMCG_KMEM */
476 #if defined(CONFIG_INET) && defined(CONFIG_MEMCG_KMEM)
477 static void disarm_sock_keys(struct mem_cgroup
*memcg
)
479 if (!memcg_proto_activated(&memcg
->tcp_mem
.cg_proto
))
481 static_key_slow_dec(&memcg_socket_limit_enabled
);
484 static void disarm_sock_keys(struct mem_cgroup
*memcg
)
489 static void drain_all_stock_async(struct mem_cgroup
*memcg
);
491 static struct mem_cgroup_per_zone
*
492 mem_cgroup_zoneinfo(struct mem_cgroup
*memcg
, int nid
, int zid
)
494 return &memcg
->info
.nodeinfo
[nid
]->zoneinfo
[zid
];
497 struct cgroup_subsys_state
*mem_cgroup_css(struct mem_cgroup
*memcg
)
502 static struct mem_cgroup_per_zone
*
503 page_cgroup_zoneinfo(struct mem_cgroup
*memcg
, struct page
*page
)
505 int nid
= page_to_nid(page
);
506 int zid
= page_zonenum(page
);
508 return mem_cgroup_zoneinfo(memcg
, nid
, zid
);
511 static struct mem_cgroup_tree_per_zone
*
512 soft_limit_tree_node_zone(int nid
, int zid
)
514 return &soft_limit_tree
.rb_tree_per_node
[nid
]->rb_tree_per_zone
[zid
];
517 static struct mem_cgroup_tree_per_zone
*
518 soft_limit_tree_from_page(struct page
*page
)
520 int nid
= page_to_nid(page
);
521 int zid
= page_zonenum(page
);
523 return &soft_limit_tree
.rb_tree_per_node
[nid
]->rb_tree_per_zone
[zid
];
527 __mem_cgroup_insert_exceeded(struct mem_cgroup
*memcg
,
528 struct mem_cgroup_per_zone
*mz
,
529 struct mem_cgroup_tree_per_zone
*mctz
,
530 unsigned long long new_usage_in_excess
)
532 struct rb_node
**p
= &mctz
->rb_root
.rb_node
;
533 struct rb_node
*parent
= NULL
;
534 struct mem_cgroup_per_zone
*mz_node
;
539 mz
->usage_in_excess
= new_usage_in_excess
;
540 if (!mz
->usage_in_excess
)
544 mz_node
= rb_entry(parent
, struct mem_cgroup_per_zone
,
546 if (mz
->usage_in_excess
< mz_node
->usage_in_excess
)
549 * We can't avoid mem cgroups that are over their soft
550 * limit by the same amount
552 else if (mz
->usage_in_excess
>= mz_node
->usage_in_excess
)
555 rb_link_node(&mz
->tree_node
, parent
, p
);
556 rb_insert_color(&mz
->tree_node
, &mctz
->rb_root
);
561 __mem_cgroup_remove_exceeded(struct mem_cgroup
*memcg
,
562 struct mem_cgroup_per_zone
*mz
,
563 struct mem_cgroup_tree_per_zone
*mctz
)
567 rb_erase(&mz
->tree_node
, &mctz
->rb_root
);
572 mem_cgroup_remove_exceeded(struct mem_cgroup
*memcg
,
573 struct mem_cgroup_per_zone
*mz
,
574 struct mem_cgroup_tree_per_zone
*mctz
)
576 spin_lock(&mctz
->lock
);
577 __mem_cgroup_remove_exceeded(memcg
, mz
, mctz
);
578 spin_unlock(&mctz
->lock
);
582 static void mem_cgroup_update_tree(struct mem_cgroup
*memcg
, struct page
*page
)
584 unsigned long long excess
;
585 struct mem_cgroup_per_zone
*mz
;
586 struct mem_cgroup_tree_per_zone
*mctz
;
587 int nid
= page_to_nid(page
);
588 int zid
= page_zonenum(page
);
589 mctz
= soft_limit_tree_from_page(page
);
592 * Necessary to update all ancestors when hierarchy is used.
593 * because their event counter is not touched.
595 for (; memcg
; memcg
= parent_mem_cgroup(memcg
)) {
596 mz
= mem_cgroup_zoneinfo(memcg
, nid
, zid
);
597 excess
= res_counter_soft_limit_excess(&memcg
->res
);
599 * We have to update the tree if mz is on RB-tree or
600 * mem is over its softlimit.
602 if (excess
|| mz
->on_tree
) {
603 spin_lock(&mctz
->lock
);
604 /* if on-tree, remove it */
606 __mem_cgroup_remove_exceeded(memcg
, mz
, mctz
);
608 * Insert again. mz->usage_in_excess will be updated.
609 * If excess is 0, no tree ops.
611 __mem_cgroup_insert_exceeded(memcg
, mz
, mctz
, excess
);
612 spin_unlock(&mctz
->lock
);
617 static void mem_cgroup_remove_from_trees(struct mem_cgroup
*memcg
)
620 struct mem_cgroup_per_zone
*mz
;
621 struct mem_cgroup_tree_per_zone
*mctz
;
623 for_each_node(node
) {
624 for (zone
= 0; zone
< MAX_NR_ZONES
; zone
++) {
625 mz
= mem_cgroup_zoneinfo(memcg
, node
, zone
);
626 mctz
= soft_limit_tree_node_zone(node
, zone
);
627 mem_cgroup_remove_exceeded(memcg
, mz
, mctz
);
632 static struct mem_cgroup_per_zone
*
633 __mem_cgroup_largest_soft_limit_node(struct mem_cgroup_tree_per_zone
*mctz
)
635 struct rb_node
*rightmost
= NULL
;
636 struct mem_cgroup_per_zone
*mz
;
640 rightmost
= rb_last(&mctz
->rb_root
);
642 goto done
; /* Nothing to reclaim from */
644 mz
= rb_entry(rightmost
, struct mem_cgroup_per_zone
, tree_node
);
646 * Remove the node now but someone else can add it back,
647 * we will to add it back at the end of reclaim to its correct
648 * position in the tree.
650 __mem_cgroup_remove_exceeded(mz
->memcg
, mz
, mctz
);
651 if (!res_counter_soft_limit_excess(&mz
->memcg
->res
) ||
652 !css_tryget(&mz
->memcg
->css
))
658 static struct mem_cgroup_per_zone
*
659 mem_cgroup_largest_soft_limit_node(struct mem_cgroup_tree_per_zone
*mctz
)
661 struct mem_cgroup_per_zone
*mz
;
663 spin_lock(&mctz
->lock
);
664 mz
= __mem_cgroup_largest_soft_limit_node(mctz
);
665 spin_unlock(&mctz
->lock
);
670 * Implementation Note: reading percpu statistics for memcg.
672 * Both of vmstat[] and percpu_counter has threshold and do periodic
673 * synchronization to implement "quick" read. There are trade-off between
674 * reading cost and precision of value. Then, we may have a chance to implement
675 * a periodic synchronizion of counter in memcg's counter.
677 * But this _read() function is used for user interface now. The user accounts
678 * memory usage by memory cgroup and he _always_ requires exact value because
679 * he accounts memory. Even if we provide quick-and-fuzzy read, we always
680 * have to visit all online cpus and make sum. So, for now, unnecessary
681 * synchronization is not implemented. (just implemented for cpu hotplug)
683 * If there are kernel internal actions which can make use of some not-exact
684 * value, and reading all cpu value can be performance bottleneck in some
685 * common workload, threashold and synchonization as vmstat[] should be
688 static long mem_cgroup_read_stat(struct mem_cgroup
*memcg
,
689 enum mem_cgroup_stat_index idx
)
695 for_each_online_cpu(cpu
)
696 val
+= per_cpu(memcg
->stat
->count
[idx
], cpu
);
697 #ifdef CONFIG_HOTPLUG_CPU
698 spin_lock(&memcg
->pcp_counter_lock
);
699 val
+= memcg
->nocpu_base
.count
[idx
];
700 spin_unlock(&memcg
->pcp_counter_lock
);
706 static void mem_cgroup_swap_statistics(struct mem_cgroup
*memcg
,
709 int val
= (charge
) ? 1 : -1;
710 this_cpu_add(memcg
->stat
->count
[MEM_CGROUP_STAT_SWAP
], val
);
713 static unsigned long mem_cgroup_read_events(struct mem_cgroup
*memcg
,
714 enum mem_cgroup_events_index idx
)
716 unsigned long val
= 0;
719 for_each_online_cpu(cpu
)
720 val
+= per_cpu(memcg
->stat
->events
[idx
], cpu
);
721 #ifdef CONFIG_HOTPLUG_CPU
722 spin_lock(&memcg
->pcp_counter_lock
);
723 val
+= memcg
->nocpu_base
.events
[idx
];
724 spin_unlock(&memcg
->pcp_counter_lock
);
729 static void mem_cgroup_charge_statistics(struct mem_cgroup
*memcg
,
730 bool anon
, int nr_pages
)
735 * Here, RSS means 'mapped anon' and anon's SwapCache. Shmem/tmpfs is
736 * counted as CACHE even if it's on ANON LRU.
739 __this_cpu_add(memcg
->stat
->count
[MEM_CGROUP_STAT_RSS
],
742 __this_cpu_add(memcg
->stat
->count
[MEM_CGROUP_STAT_CACHE
],
745 /* pagein of a big page is an event. So, ignore page size */
747 __this_cpu_inc(memcg
->stat
->events
[MEM_CGROUP_EVENTS_PGPGIN
]);
749 __this_cpu_inc(memcg
->stat
->events
[MEM_CGROUP_EVENTS_PGPGOUT
]);
750 nr_pages
= -nr_pages
; /* for event */
753 __this_cpu_add(memcg
->stat
->nr_page_events
, nr_pages
);
759 mem_cgroup_get_lru_size(struct lruvec
*lruvec
, enum lru_list lru
)
761 struct mem_cgroup_per_zone
*mz
;
763 mz
= container_of(lruvec
, struct mem_cgroup_per_zone
, lruvec
);
764 return mz
->lru_size
[lru
];
768 mem_cgroup_zone_nr_lru_pages(struct mem_cgroup
*memcg
, int nid
, int zid
,
769 unsigned int lru_mask
)
771 struct mem_cgroup_per_zone
*mz
;
773 unsigned long ret
= 0;
775 mz
= mem_cgroup_zoneinfo(memcg
, nid
, zid
);
778 if (BIT(lru
) & lru_mask
)
779 ret
+= mz
->lru_size
[lru
];
785 mem_cgroup_node_nr_lru_pages(struct mem_cgroup
*memcg
,
786 int nid
, unsigned int lru_mask
)
791 for (zid
= 0; zid
< MAX_NR_ZONES
; zid
++)
792 total
+= mem_cgroup_zone_nr_lru_pages(memcg
,
798 static unsigned long mem_cgroup_nr_lru_pages(struct mem_cgroup
*memcg
,
799 unsigned int lru_mask
)
804 for_each_node_state(nid
, N_HIGH_MEMORY
)
805 total
+= mem_cgroup_node_nr_lru_pages(memcg
, nid
, lru_mask
);
809 static bool mem_cgroup_event_ratelimit(struct mem_cgroup
*memcg
,
810 enum mem_cgroup_events_target target
)
812 unsigned long val
, next
;
814 val
= __this_cpu_read(memcg
->stat
->nr_page_events
);
815 next
= __this_cpu_read(memcg
->stat
->targets
[target
]);
816 /* from time_after() in jiffies.h */
817 if ((long)next
- (long)val
< 0) {
819 case MEM_CGROUP_TARGET_THRESH
:
820 next
= val
+ THRESHOLDS_EVENTS_TARGET
;
822 case MEM_CGROUP_TARGET_SOFTLIMIT
:
823 next
= val
+ SOFTLIMIT_EVENTS_TARGET
;
825 case MEM_CGROUP_TARGET_NUMAINFO
:
826 next
= val
+ NUMAINFO_EVENTS_TARGET
;
831 __this_cpu_write(memcg
->stat
->targets
[target
], next
);
838 * Check events in order.
841 static void memcg_check_events(struct mem_cgroup
*memcg
, struct page
*page
)
844 /* threshold event is triggered in finer grain than soft limit */
845 if (unlikely(mem_cgroup_event_ratelimit(memcg
,
846 MEM_CGROUP_TARGET_THRESH
))) {
848 bool do_numainfo __maybe_unused
;
850 do_softlimit
= mem_cgroup_event_ratelimit(memcg
,
851 MEM_CGROUP_TARGET_SOFTLIMIT
);
853 do_numainfo
= mem_cgroup_event_ratelimit(memcg
,
854 MEM_CGROUP_TARGET_NUMAINFO
);
858 mem_cgroup_threshold(memcg
);
859 if (unlikely(do_softlimit
))
860 mem_cgroup_update_tree(memcg
, page
);
862 if (unlikely(do_numainfo
))
863 atomic_inc(&memcg
->numainfo_events
);
869 struct mem_cgroup
*mem_cgroup_from_cont(struct cgroup
*cont
)
871 return mem_cgroup_from_css(
872 cgroup_subsys_state(cont
, mem_cgroup_subsys_id
));
875 struct mem_cgroup
*mem_cgroup_from_task(struct task_struct
*p
)
878 * mm_update_next_owner() may clear mm->owner to NULL
879 * if it races with swapoff, page migration, etc.
880 * So this can be called with p == NULL.
885 return mem_cgroup_from_css(task_subsys_state(p
, mem_cgroup_subsys_id
));
888 struct mem_cgroup
*try_get_mem_cgroup_from_mm(struct mm_struct
*mm
)
890 struct mem_cgroup
*memcg
= NULL
;
895 * Because we have no locks, mm->owner's may be being moved to other
896 * cgroup. We use css_tryget() here even if this looks
897 * pessimistic (rather than adding locks here).
901 memcg
= mem_cgroup_from_task(rcu_dereference(mm
->owner
));
902 if (unlikely(!memcg
))
904 } while (!css_tryget(&memcg
->css
));
910 * mem_cgroup_iter - iterate over memory cgroup hierarchy
911 * @root: hierarchy root
912 * @prev: previously returned memcg, NULL on first invocation
913 * @reclaim: cookie for shared reclaim walks, NULL for full walks
915 * Returns references to children of the hierarchy below @root, or
916 * @root itself, or %NULL after a full round-trip.
918 * Caller must pass the return value in @prev on subsequent
919 * invocations for reference counting, or use mem_cgroup_iter_break()
920 * to cancel a hierarchy walk before the round-trip is complete.
922 * Reclaimers can specify a zone and a priority level in @reclaim to
923 * divide up the memcgs in the hierarchy among all concurrent
924 * reclaimers operating on the same zone and priority.
926 struct mem_cgroup
*mem_cgroup_iter(struct mem_cgroup
*root
,
927 struct mem_cgroup
*prev
,
928 struct mem_cgroup_reclaim_cookie
*reclaim
)
930 struct mem_cgroup
*memcg
= NULL
;
933 if (mem_cgroup_disabled())
937 root
= root_mem_cgroup
;
939 if (prev
&& !reclaim
)
940 id
= css_id(&prev
->css
);
942 if (prev
&& prev
!= root
)
945 if (!root
->use_hierarchy
&& root
!= root_mem_cgroup
) {
952 struct mem_cgroup_reclaim_iter
*uninitialized_var(iter
);
953 struct cgroup_subsys_state
*css
;
956 int nid
= zone_to_nid(reclaim
->zone
);
957 int zid
= zone_idx(reclaim
->zone
);
958 struct mem_cgroup_per_zone
*mz
;
960 mz
= mem_cgroup_zoneinfo(root
, nid
, zid
);
961 iter
= &mz
->reclaim_iter
[reclaim
->priority
];
962 if (prev
&& reclaim
->generation
!= iter
->generation
)
968 css
= css_get_next(&mem_cgroup_subsys
, id
+ 1, &root
->css
, &id
);
970 if (css
== &root
->css
|| css_tryget(css
))
971 memcg
= mem_cgroup_from_css(css
);
980 else if (!prev
&& memcg
)
981 reclaim
->generation
= iter
->generation
;
991 * mem_cgroup_iter_break - abort a hierarchy walk prematurely
992 * @root: hierarchy root
993 * @prev: last visited hierarchy member as returned by mem_cgroup_iter()
995 void mem_cgroup_iter_break(struct mem_cgroup
*root
,
996 struct mem_cgroup
*prev
)
999 root
= root_mem_cgroup
;
1000 if (prev
&& prev
!= root
)
1001 css_put(&prev
->css
);
1005 * Iteration constructs for visiting all cgroups (under a tree). If
1006 * loops are exited prematurely (break), mem_cgroup_iter_break() must
1007 * be used for reference counting.
1009 #define for_each_mem_cgroup_tree(iter, root) \
1010 for (iter = mem_cgroup_iter(root, NULL, NULL); \
1012 iter = mem_cgroup_iter(root, iter, NULL))
1014 #define for_each_mem_cgroup(iter) \
1015 for (iter = mem_cgroup_iter(NULL, NULL, NULL); \
1017 iter = mem_cgroup_iter(NULL, iter, NULL))
1019 static inline bool mem_cgroup_is_root(struct mem_cgroup
*memcg
)
1021 return (memcg
== root_mem_cgroup
);
1024 void mem_cgroup_count_vm_event(struct mm_struct
*mm
, enum vm_event_item idx
)
1026 struct mem_cgroup
*memcg
;
1032 memcg
= mem_cgroup_from_task(rcu_dereference(mm
->owner
));
1033 if (unlikely(!memcg
))
1038 this_cpu_inc(memcg
->stat
->events
[MEM_CGROUP_EVENTS_PGFAULT
]);
1041 this_cpu_inc(memcg
->stat
->events
[MEM_CGROUP_EVENTS_PGMAJFAULT
]);
1049 EXPORT_SYMBOL(mem_cgroup_count_vm_event
);
1052 * mem_cgroup_zone_lruvec - get the lru list vector for a zone and memcg
1053 * @zone: zone of the wanted lruvec
1054 * @memcg: memcg of the wanted lruvec
1056 * Returns the lru list vector holding pages for the given @zone and
1057 * @mem. This can be the global zone lruvec, if the memory controller
1060 struct lruvec
*mem_cgroup_zone_lruvec(struct zone
*zone
,
1061 struct mem_cgroup
*memcg
)
1063 struct mem_cgroup_per_zone
*mz
;
1065 if (mem_cgroup_disabled())
1066 return &zone
->lruvec
;
1068 mz
= mem_cgroup_zoneinfo(memcg
, zone_to_nid(zone
), zone_idx(zone
));
1073 * Following LRU functions are allowed to be used without PCG_LOCK.
1074 * Operations are called by routine of global LRU independently from memcg.
1075 * What we have to take care of here is validness of pc->mem_cgroup.
1077 * Changes to pc->mem_cgroup happens when
1080 * In typical case, "charge" is done before add-to-lru. Exception is SwapCache.
1081 * It is added to LRU before charge.
1082 * If PCG_USED bit is not set, page_cgroup is not added to this private LRU.
1083 * When moving account, the page is not on LRU. It's isolated.
1087 * mem_cgroup_page_lruvec - return lruvec for adding an lru page
1089 * @zone: zone of the page
1091 struct lruvec
*mem_cgroup_page_lruvec(struct page
*page
, struct zone
*zone
)
1093 struct mem_cgroup_per_zone
*mz
;
1094 struct mem_cgroup
*memcg
;
1095 struct page_cgroup
*pc
;
1097 if (mem_cgroup_disabled())
1098 return &zone
->lruvec
;
1100 pc
= lookup_page_cgroup(page
);
1101 memcg
= pc
->mem_cgroup
;
1104 * Surreptitiously switch any uncharged offlist page to root:
1105 * an uncharged page off lru does nothing to secure
1106 * its former mem_cgroup from sudden removal.
1108 * Our caller holds lru_lock, and PageCgroupUsed is updated
1109 * under page_cgroup lock: between them, they make all uses
1110 * of pc->mem_cgroup safe.
1112 if (!PageLRU(page
) && !PageCgroupUsed(pc
) && memcg
!= root_mem_cgroup
)
1113 pc
->mem_cgroup
= memcg
= root_mem_cgroup
;
1115 mz
= page_cgroup_zoneinfo(memcg
, page
);
1120 * mem_cgroup_update_lru_size - account for adding or removing an lru page
1121 * @lruvec: mem_cgroup per zone lru vector
1122 * @lru: index of lru list the page is sitting on
1123 * @nr_pages: positive when adding or negative when removing
1125 * This function must be called when a page is added to or removed from an
1128 void mem_cgroup_update_lru_size(struct lruvec
*lruvec
, enum lru_list lru
,
1131 struct mem_cgroup_per_zone
*mz
;
1132 unsigned long *lru_size
;
1134 if (mem_cgroup_disabled())
1137 mz
= container_of(lruvec
, struct mem_cgroup_per_zone
, lruvec
);
1138 lru_size
= mz
->lru_size
+ lru
;
1139 *lru_size
+= nr_pages
;
1140 VM_BUG_ON((long)(*lru_size
) < 0);
1144 * Checks whether given mem is same or in the root_mem_cgroup's
1147 bool __mem_cgroup_same_or_subtree(const struct mem_cgroup
*root_memcg
,
1148 struct mem_cgroup
*memcg
)
1150 if (root_memcg
== memcg
)
1152 if (!root_memcg
->use_hierarchy
|| !memcg
)
1154 return css_is_ancestor(&memcg
->css
, &root_memcg
->css
);
1157 static bool mem_cgroup_same_or_subtree(const struct mem_cgroup
*root_memcg
,
1158 struct mem_cgroup
*memcg
)
1163 ret
= __mem_cgroup_same_or_subtree(root_memcg
, memcg
);
1168 int task_in_mem_cgroup(struct task_struct
*task
, const struct mem_cgroup
*memcg
)
1171 struct mem_cgroup
*curr
= NULL
;
1172 struct task_struct
*p
;
1174 p
= find_lock_task_mm(task
);
1176 curr
= try_get_mem_cgroup_from_mm(p
->mm
);
1180 * All threads may have already detached their mm's, but the oom
1181 * killer still needs to detect if they have already been oom
1182 * killed to prevent needlessly killing additional tasks.
1185 curr
= mem_cgroup_from_task(task
);
1187 css_get(&curr
->css
);
1193 * We should check use_hierarchy of "memcg" not "curr". Because checking
1194 * use_hierarchy of "curr" here make this function true if hierarchy is
1195 * enabled in "curr" and "curr" is a child of "memcg" in *cgroup*
1196 * hierarchy(even if use_hierarchy is disabled in "memcg").
1198 ret
= mem_cgroup_same_or_subtree(memcg
, curr
);
1199 css_put(&curr
->css
);
1203 int mem_cgroup_inactive_anon_is_low(struct lruvec
*lruvec
)
1205 unsigned long inactive_ratio
;
1206 unsigned long inactive
;
1207 unsigned long active
;
1210 inactive
= mem_cgroup_get_lru_size(lruvec
, LRU_INACTIVE_ANON
);
1211 active
= mem_cgroup_get_lru_size(lruvec
, LRU_ACTIVE_ANON
);
1213 gb
= (inactive
+ active
) >> (30 - PAGE_SHIFT
);
1215 inactive_ratio
= int_sqrt(10 * gb
);
1219 return inactive
* inactive_ratio
< active
;
1222 int mem_cgroup_inactive_file_is_low(struct lruvec
*lruvec
)
1224 unsigned long active
;
1225 unsigned long inactive
;
1227 inactive
= mem_cgroup_get_lru_size(lruvec
, LRU_INACTIVE_FILE
);
1228 active
= mem_cgroup_get_lru_size(lruvec
, LRU_ACTIVE_FILE
);
1230 return (active
> inactive
);
1233 #define mem_cgroup_from_res_counter(counter, member) \
1234 container_of(counter, struct mem_cgroup, member)
1237 * mem_cgroup_margin - calculate chargeable space of a memory cgroup
1238 * @memcg: the memory cgroup
1240 * Returns the maximum amount of memory @mem can be charged with, in
1243 static unsigned long mem_cgroup_margin(struct mem_cgroup
*memcg
)
1245 unsigned long long margin
;
1247 margin
= res_counter_margin(&memcg
->res
);
1248 if (do_swap_account
)
1249 margin
= min(margin
, res_counter_margin(&memcg
->memsw
));
1250 return margin
>> PAGE_SHIFT
;
1253 int mem_cgroup_swappiness(struct mem_cgroup
*memcg
)
1255 struct cgroup
*cgrp
= memcg
->css
.cgroup
;
1258 if (cgrp
->parent
== NULL
)
1259 return vm_swappiness
;
1261 return memcg
->swappiness
;
1265 * memcg->moving_account is used for checking possibility that some thread is
1266 * calling move_account(). When a thread on CPU-A starts moving pages under
1267 * a memcg, other threads should check memcg->moving_account under
1268 * rcu_read_lock(), like this:
1272 * memcg->moving_account+1 if (memcg->mocing_account)
1274 * synchronize_rcu() update something.
1279 /* for quick checking without looking up memcg */
1280 atomic_t memcg_moving __read_mostly
;
1282 static void mem_cgroup_start_move(struct mem_cgroup
*memcg
)
1284 atomic_inc(&memcg_moving
);
1285 atomic_inc(&memcg
->moving_account
);
1289 static void mem_cgroup_end_move(struct mem_cgroup
*memcg
)
1292 * Now, mem_cgroup_clear_mc() may call this function with NULL.
1293 * We check NULL in callee rather than caller.
1296 atomic_dec(&memcg_moving
);
1297 atomic_dec(&memcg
->moving_account
);
1302 * 2 routines for checking "mem" is under move_account() or not.
1304 * mem_cgroup_stolen() - checking whether a cgroup is mc.from or not. This
1305 * is used for avoiding races in accounting. If true,
1306 * pc->mem_cgroup may be overwritten.
1308 * mem_cgroup_under_move() - checking a cgroup is mc.from or mc.to or
1309 * under hierarchy of moving cgroups. This is for
1310 * waiting at hith-memory prressure caused by "move".
1313 static bool mem_cgroup_stolen(struct mem_cgroup
*memcg
)
1315 VM_BUG_ON(!rcu_read_lock_held());
1316 return atomic_read(&memcg
->moving_account
) > 0;
1319 static bool mem_cgroup_under_move(struct mem_cgroup
*memcg
)
1321 struct mem_cgroup
*from
;
1322 struct mem_cgroup
*to
;
1325 * Unlike task_move routines, we access mc.to, mc.from not under
1326 * mutual exclusion by cgroup_mutex. Here, we take spinlock instead.
1328 spin_lock(&mc
.lock
);
1334 ret
= mem_cgroup_same_or_subtree(memcg
, from
)
1335 || mem_cgroup_same_or_subtree(memcg
, to
);
1337 spin_unlock(&mc
.lock
);
1341 static bool mem_cgroup_wait_acct_move(struct mem_cgroup
*memcg
)
1343 if (mc
.moving_task
&& current
!= mc
.moving_task
) {
1344 if (mem_cgroup_under_move(memcg
)) {
1346 prepare_to_wait(&mc
.waitq
, &wait
, TASK_INTERRUPTIBLE
);
1347 /* moving charge context might have finished. */
1350 finish_wait(&mc
.waitq
, &wait
);
1358 * Take this lock when
1359 * - a code tries to modify page's memcg while it's USED.
1360 * - a code tries to modify page state accounting in a memcg.
1361 * see mem_cgroup_stolen(), too.
1363 static void move_lock_mem_cgroup(struct mem_cgroup
*memcg
,
1364 unsigned long *flags
)
1366 spin_lock_irqsave(&memcg
->move_lock
, *flags
);
1369 static void move_unlock_mem_cgroup(struct mem_cgroup
*memcg
,
1370 unsigned long *flags
)
1372 spin_unlock_irqrestore(&memcg
->move_lock
, *flags
);
1376 * mem_cgroup_print_oom_info: Called from OOM with tasklist_lock held in read mode.
1377 * @memcg: The memory cgroup that went over limit
1378 * @p: Task that is going to be killed
1380 * NOTE: @memcg and @p's mem_cgroup can be different when hierarchy is
1383 void mem_cgroup_print_oom_info(struct mem_cgroup
*memcg
, struct task_struct
*p
)
1385 struct cgroup
*task_cgrp
;
1386 struct cgroup
*mem_cgrp
;
1388 * Need a buffer in BSS, can't rely on allocations. The code relies
1389 * on the assumption that OOM is serialized for memory controller.
1390 * If this assumption is broken, revisit this code.
1392 static char memcg_name
[PATH_MAX
];
1400 mem_cgrp
= memcg
->css
.cgroup
;
1401 task_cgrp
= task_cgroup(p
, mem_cgroup_subsys_id
);
1403 ret
= cgroup_path(task_cgrp
, memcg_name
, PATH_MAX
);
1406 * Unfortunately, we are unable to convert to a useful name
1407 * But we'll still print out the usage information
1414 printk(KERN_INFO
"Task in %s killed", memcg_name
);
1417 ret
= cgroup_path(mem_cgrp
, memcg_name
, PATH_MAX
);
1425 * Continues from above, so we don't need an KERN_ level
1427 printk(KERN_CONT
" as a result of limit of %s\n", memcg_name
);
1430 printk(KERN_INFO
"memory: usage %llukB, limit %llukB, failcnt %llu\n",
1431 res_counter_read_u64(&memcg
->res
, RES_USAGE
) >> 10,
1432 res_counter_read_u64(&memcg
->res
, RES_LIMIT
) >> 10,
1433 res_counter_read_u64(&memcg
->res
, RES_FAILCNT
));
1434 printk(KERN_INFO
"memory+swap: usage %llukB, limit %llukB, "
1436 res_counter_read_u64(&memcg
->memsw
, RES_USAGE
) >> 10,
1437 res_counter_read_u64(&memcg
->memsw
, RES_LIMIT
) >> 10,
1438 res_counter_read_u64(&memcg
->memsw
, RES_FAILCNT
));
1442 * This function returns the number of memcg under hierarchy tree. Returns
1443 * 1(self count) if no children.
1445 static int mem_cgroup_count_children(struct mem_cgroup
*memcg
)
1448 struct mem_cgroup
*iter
;
1450 for_each_mem_cgroup_tree(iter
, memcg
)
1456 * Return the memory (and swap, if configured) limit for a memcg.
1458 static u64
mem_cgroup_get_limit(struct mem_cgroup
*memcg
)
1463 limit
= res_counter_read_u64(&memcg
->res
, RES_LIMIT
);
1464 limit
+= total_swap_pages
<< PAGE_SHIFT
;
1466 memsw
= res_counter_read_u64(&memcg
->memsw
, RES_LIMIT
);
1468 * If memsw is finite and limits the amount of swap space available
1469 * to this memcg, return that limit.
1471 return min(limit
, memsw
);
1474 void mem_cgroup_out_of_memory(struct mem_cgroup
*memcg
, gfp_t gfp_mask
,
1477 struct mem_cgroup
*iter
;
1478 unsigned long chosen_points
= 0;
1479 unsigned long totalpages
;
1480 unsigned int points
= 0;
1481 struct task_struct
*chosen
= NULL
;
1484 * If current has a pending SIGKILL, then automatically select it. The
1485 * goal is to allow it to allocate so that it may quickly exit and free
1488 if (fatal_signal_pending(current
)) {
1489 set_thread_flag(TIF_MEMDIE
);
1493 check_panic_on_oom(CONSTRAINT_MEMCG
, gfp_mask
, order
, NULL
);
1494 totalpages
= mem_cgroup_get_limit(memcg
) >> PAGE_SHIFT
? : 1;
1495 for_each_mem_cgroup_tree(iter
, memcg
) {
1496 struct cgroup
*cgroup
= iter
->css
.cgroup
;
1497 struct cgroup_iter it
;
1498 struct task_struct
*task
;
1500 cgroup_iter_start(cgroup
, &it
);
1501 while ((task
= cgroup_iter_next(cgroup
, &it
))) {
1502 switch (oom_scan_process_thread(task
, totalpages
, NULL
,
1504 case OOM_SCAN_SELECT
:
1506 put_task_struct(chosen
);
1508 chosen_points
= ULONG_MAX
;
1509 get_task_struct(chosen
);
1511 case OOM_SCAN_CONTINUE
:
1513 case OOM_SCAN_ABORT
:
1514 cgroup_iter_end(cgroup
, &it
);
1515 mem_cgroup_iter_break(memcg
, iter
);
1517 put_task_struct(chosen
);
1522 points
= oom_badness(task
, memcg
, NULL
, totalpages
);
1523 if (points
> chosen_points
) {
1525 put_task_struct(chosen
);
1527 chosen_points
= points
;
1528 get_task_struct(chosen
);
1531 cgroup_iter_end(cgroup
, &it
);
1536 points
= chosen_points
* 1000 / totalpages
;
1537 oom_kill_process(chosen
, gfp_mask
, order
, points
, totalpages
, memcg
,
1538 NULL
, "Memory cgroup out of memory");
1541 static unsigned long mem_cgroup_reclaim(struct mem_cgroup
*memcg
,
1543 unsigned long flags
)
1545 unsigned long total
= 0;
1546 bool noswap
= false;
1549 if (flags
& MEM_CGROUP_RECLAIM_NOSWAP
)
1551 if (!(flags
& MEM_CGROUP_RECLAIM_SHRINK
) && memcg
->memsw_is_minimum
)
1554 for (loop
= 0; loop
< MEM_CGROUP_MAX_RECLAIM_LOOPS
; loop
++) {
1556 drain_all_stock_async(memcg
);
1557 total
+= try_to_free_mem_cgroup_pages(memcg
, gfp_mask
, noswap
);
1559 * Allow limit shrinkers, which are triggered directly
1560 * by userspace, to catch signals and stop reclaim
1561 * after minimal progress, regardless of the margin.
1563 if (total
&& (flags
& MEM_CGROUP_RECLAIM_SHRINK
))
1565 if (mem_cgroup_margin(memcg
))
1568 * If nothing was reclaimed after two attempts, there
1569 * may be no reclaimable pages in this hierarchy.
1578 * test_mem_cgroup_node_reclaimable
1579 * @memcg: the target memcg
1580 * @nid: the node ID to be checked.
1581 * @noswap : specify true here if the user wants flle only information.
1583 * This function returns whether the specified memcg contains any
1584 * reclaimable pages on a node. Returns true if there are any reclaimable
1585 * pages in the node.
1587 static bool test_mem_cgroup_node_reclaimable(struct mem_cgroup
*memcg
,
1588 int nid
, bool noswap
)
1590 if (mem_cgroup_node_nr_lru_pages(memcg
, nid
, LRU_ALL_FILE
))
1592 if (noswap
|| !total_swap_pages
)
1594 if (mem_cgroup_node_nr_lru_pages(memcg
, nid
, LRU_ALL_ANON
))
1599 #if MAX_NUMNODES > 1
1602 * Always updating the nodemask is not very good - even if we have an empty
1603 * list or the wrong list here, we can start from some node and traverse all
1604 * nodes based on the zonelist. So update the list loosely once per 10 secs.
1607 static void mem_cgroup_may_update_nodemask(struct mem_cgroup
*memcg
)
1611 * numainfo_events > 0 means there was at least NUMAINFO_EVENTS_TARGET
1612 * pagein/pageout changes since the last update.
1614 if (!atomic_read(&memcg
->numainfo_events
))
1616 if (atomic_inc_return(&memcg
->numainfo_updating
) > 1)
1619 /* make a nodemask where this memcg uses memory from */
1620 memcg
->scan_nodes
= node_states
[N_HIGH_MEMORY
];
1622 for_each_node_mask(nid
, node_states
[N_HIGH_MEMORY
]) {
1624 if (!test_mem_cgroup_node_reclaimable(memcg
, nid
, false))
1625 node_clear(nid
, memcg
->scan_nodes
);
1628 atomic_set(&memcg
->numainfo_events
, 0);
1629 atomic_set(&memcg
->numainfo_updating
, 0);
1633 * Selecting a node where we start reclaim from. Because what we need is just
1634 * reducing usage counter, start from anywhere is O,K. Considering
1635 * memory reclaim from current node, there are pros. and cons.
1637 * Freeing memory from current node means freeing memory from a node which
1638 * we'll use or we've used. So, it may make LRU bad. And if several threads
1639 * hit limits, it will see a contention on a node. But freeing from remote
1640 * node means more costs for memory reclaim because of memory latency.
1642 * Now, we use round-robin. Better algorithm is welcomed.
1644 int mem_cgroup_select_victim_node(struct mem_cgroup
*memcg
)
1648 mem_cgroup_may_update_nodemask(memcg
);
1649 node
= memcg
->last_scanned_node
;
1651 node
= next_node(node
, memcg
->scan_nodes
);
1652 if (node
== MAX_NUMNODES
)
1653 node
= first_node(memcg
->scan_nodes
);
1655 * We call this when we hit limit, not when pages are added to LRU.
1656 * No LRU may hold pages because all pages are UNEVICTABLE or
1657 * memcg is too small and all pages are not on LRU. In that case,
1658 * we use curret node.
1660 if (unlikely(node
== MAX_NUMNODES
))
1661 node
= numa_node_id();
1663 memcg
->last_scanned_node
= node
;
1668 * Check all nodes whether it contains reclaimable pages or not.
1669 * For quick scan, we make use of scan_nodes. This will allow us to skip
1670 * unused nodes. But scan_nodes is lazily updated and may not cotain
1671 * enough new information. We need to do double check.
1673 static bool mem_cgroup_reclaimable(struct mem_cgroup
*memcg
, bool noswap
)
1678 * quick check...making use of scan_node.
1679 * We can skip unused nodes.
1681 if (!nodes_empty(memcg
->scan_nodes
)) {
1682 for (nid
= first_node(memcg
->scan_nodes
);
1684 nid
= next_node(nid
, memcg
->scan_nodes
)) {
1686 if (test_mem_cgroup_node_reclaimable(memcg
, nid
, noswap
))
1691 * Check rest of nodes.
1693 for_each_node_state(nid
, N_HIGH_MEMORY
) {
1694 if (node_isset(nid
, memcg
->scan_nodes
))
1696 if (test_mem_cgroup_node_reclaimable(memcg
, nid
, noswap
))
1703 int mem_cgroup_select_victim_node(struct mem_cgroup
*memcg
)
1708 static bool mem_cgroup_reclaimable(struct mem_cgroup
*memcg
, bool noswap
)
1710 return test_mem_cgroup_node_reclaimable(memcg
, 0, noswap
);
1714 static int mem_cgroup_soft_reclaim(struct mem_cgroup
*root_memcg
,
1717 unsigned long *total_scanned
)
1719 struct mem_cgroup
*victim
= NULL
;
1722 unsigned long excess
;
1723 unsigned long nr_scanned
;
1724 struct mem_cgroup_reclaim_cookie reclaim
= {
1729 excess
= res_counter_soft_limit_excess(&root_memcg
->res
) >> PAGE_SHIFT
;
1732 victim
= mem_cgroup_iter(root_memcg
, victim
, &reclaim
);
1737 * If we have not been able to reclaim
1738 * anything, it might because there are
1739 * no reclaimable pages under this hierarchy
1744 * We want to do more targeted reclaim.
1745 * excess >> 2 is not to excessive so as to
1746 * reclaim too much, nor too less that we keep
1747 * coming back to reclaim from this cgroup
1749 if (total
>= (excess
>> 2) ||
1750 (loop
> MEM_CGROUP_MAX_RECLAIM_LOOPS
))
1755 if (!mem_cgroup_reclaimable(victim
, false))
1757 total
+= mem_cgroup_shrink_node_zone(victim
, gfp_mask
, false,
1759 *total_scanned
+= nr_scanned
;
1760 if (!res_counter_soft_limit_excess(&root_memcg
->res
))
1763 mem_cgroup_iter_break(root_memcg
, victim
);
1768 * Check OOM-Killer is already running under our hierarchy.
1769 * If someone is running, return false.
1770 * Has to be called with memcg_oom_lock
1772 static bool mem_cgroup_oom_lock(struct mem_cgroup
*memcg
)
1774 struct mem_cgroup
*iter
, *failed
= NULL
;
1776 for_each_mem_cgroup_tree(iter
, memcg
) {
1777 if (iter
->oom_lock
) {
1779 * this subtree of our hierarchy is already locked
1780 * so we cannot give a lock.
1783 mem_cgroup_iter_break(memcg
, iter
);
1786 iter
->oom_lock
= true;
1793 * OK, we failed to lock the whole subtree so we have to clean up
1794 * what we set up to the failing subtree
1796 for_each_mem_cgroup_tree(iter
, memcg
) {
1797 if (iter
== failed
) {
1798 mem_cgroup_iter_break(memcg
, iter
);
1801 iter
->oom_lock
= false;
1807 * Has to be called with memcg_oom_lock
1809 static int mem_cgroup_oom_unlock(struct mem_cgroup
*memcg
)
1811 struct mem_cgroup
*iter
;
1813 for_each_mem_cgroup_tree(iter
, memcg
)
1814 iter
->oom_lock
= false;
1818 static void mem_cgroup_mark_under_oom(struct mem_cgroup
*memcg
)
1820 struct mem_cgroup
*iter
;
1822 for_each_mem_cgroup_tree(iter
, memcg
)
1823 atomic_inc(&iter
->under_oom
);
1826 static void mem_cgroup_unmark_under_oom(struct mem_cgroup
*memcg
)
1828 struct mem_cgroup
*iter
;
1831 * When a new child is created while the hierarchy is under oom,
1832 * mem_cgroup_oom_lock() may not be called. We have to use
1833 * atomic_add_unless() here.
1835 for_each_mem_cgroup_tree(iter
, memcg
)
1836 atomic_add_unless(&iter
->under_oom
, -1, 0);
1839 static DEFINE_SPINLOCK(memcg_oom_lock
);
1840 static DECLARE_WAIT_QUEUE_HEAD(memcg_oom_waitq
);
1842 struct oom_wait_info
{
1843 struct mem_cgroup
*memcg
;
1847 static int memcg_oom_wake_function(wait_queue_t
*wait
,
1848 unsigned mode
, int sync
, void *arg
)
1850 struct mem_cgroup
*wake_memcg
= (struct mem_cgroup
*)arg
;
1851 struct mem_cgroup
*oom_wait_memcg
;
1852 struct oom_wait_info
*oom_wait_info
;
1854 oom_wait_info
= container_of(wait
, struct oom_wait_info
, wait
);
1855 oom_wait_memcg
= oom_wait_info
->memcg
;
1858 * Both of oom_wait_info->memcg and wake_memcg are stable under us.
1859 * Then we can use css_is_ancestor without taking care of RCU.
1861 if (!mem_cgroup_same_or_subtree(oom_wait_memcg
, wake_memcg
)
1862 && !mem_cgroup_same_or_subtree(wake_memcg
, oom_wait_memcg
))
1864 return autoremove_wake_function(wait
, mode
, sync
, arg
);
1867 static void memcg_wakeup_oom(struct mem_cgroup
*memcg
)
1869 /* for filtering, pass "memcg" as argument. */
1870 __wake_up(&memcg_oom_waitq
, TASK_NORMAL
, 0, memcg
);
1873 static void memcg_oom_recover(struct mem_cgroup
*memcg
)
1875 if (memcg
&& atomic_read(&memcg
->under_oom
))
1876 memcg_wakeup_oom(memcg
);
1880 * try to call OOM killer. returns false if we should exit memory-reclaim loop.
1882 static bool mem_cgroup_handle_oom(struct mem_cgroup
*memcg
, gfp_t mask
,
1885 struct oom_wait_info owait
;
1886 bool locked
, need_to_kill
;
1888 owait
.memcg
= memcg
;
1889 owait
.wait
.flags
= 0;
1890 owait
.wait
.func
= memcg_oom_wake_function
;
1891 owait
.wait
.private = current
;
1892 INIT_LIST_HEAD(&owait
.wait
.task_list
);
1893 need_to_kill
= true;
1894 mem_cgroup_mark_under_oom(memcg
);
1896 /* At first, try to OOM lock hierarchy under memcg.*/
1897 spin_lock(&memcg_oom_lock
);
1898 locked
= mem_cgroup_oom_lock(memcg
);
1900 * Even if signal_pending(), we can't quit charge() loop without
1901 * accounting. So, UNINTERRUPTIBLE is appropriate. But SIGKILL
1902 * under OOM is always welcomed, use TASK_KILLABLE here.
1904 prepare_to_wait(&memcg_oom_waitq
, &owait
.wait
, TASK_KILLABLE
);
1905 if (!locked
|| memcg
->oom_kill_disable
)
1906 need_to_kill
= false;
1908 mem_cgroup_oom_notify(memcg
);
1909 spin_unlock(&memcg_oom_lock
);
1912 finish_wait(&memcg_oom_waitq
, &owait
.wait
);
1913 mem_cgroup_out_of_memory(memcg
, mask
, order
);
1916 finish_wait(&memcg_oom_waitq
, &owait
.wait
);
1918 spin_lock(&memcg_oom_lock
);
1920 mem_cgroup_oom_unlock(memcg
);
1921 memcg_wakeup_oom(memcg
);
1922 spin_unlock(&memcg_oom_lock
);
1924 mem_cgroup_unmark_under_oom(memcg
);
1926 if (test_thread_flag(TIF_MEMDIE
) || fatal_signal_pending(current
))
1928 /* Give chance to dying process */
1929 schedule_timeout_uninterruptible(1);
1934 * Currently used to update mapped file statistics, but the routine can be
1935 * generalized to update other statistics as well.
1937 * Notes: Race condition
1939 * We usually use page_cgroup_lock() for accessing page_cgroup member but
1940 * it tends to be costly. But considering some conditions, we doesn't need
1941 * to do so _always_.
1943 * Considering "charge", lock_page_cgroup() is not required because all
1944 * file-stat operations happen after a page is attached to radix-tree. There
1945 * are no race with "charge".
1947 * Considering "uncharge", we know that memcg doesn't clear pc->mem_cgroup
1948 * at "uncharge" intentionally. So, we always see valid pc->mem_cgroup even
1949 * if there are race with "uncharge". Statistics itself is properly handled
1952 * Considering "move", this is an only case we see a race. To make the race
1953 * small, we check mm->moving_account and detect there are possibility of race
1954 * If there is, we take a lock.
1957 void __mem_cgroup_begin_update_page_stat(struct page
*page
,
1958 bool *locked
, unsigned long *flags
)
1960 struct mem_cgroup
*memcg
;
1961 struct page_cgroup
*pc
;
1963 pc
= lookup_page_cgroup(page
);
1965 memcg
= pc
->mem_cgroup
;
1966 if (unlikely(!memcg
|| !PageCgroupUsed(pc
)))
1969 * If this memory cgroup is not under account moving, we don't
1970 * need to take move_lock_mem_cgroup(). Because we already hold
1971 * rcu_read_lock(), any calls to move_account will be delayed until
1972 * rcu_read_unlock() if mem_cgroup_stolen() == true.
1974 if (!mem_cgroup_stolen(memcg
))
1977 move_lock_mem_cgroup(memcg
, flags
);
1978 if (memcg
!= pc
->mem_cgroup
|| !PageCgroupUsed(pc
)) {
1979 move_unlock_mem_cgroup(memcg
, flags
);
1985 void __mem_cgroup_end_update_page_stat(struct page
*page
, unsigned long *flags
)
1987 struct page_cgroup
*pc
= lookup_page_cgroup(page
);
1990 * It's guaranteed that pc->mem_cgroup never changes while
1991 * lock is held because a routine modifies pc->mem_cgroup
1992 * should take move_lock_mem_cgroup().
1994 move_unlock_mem_cgroup(pc
->mem_cgroup
, flags
);
1997 void mem_cgroup_update_page_stat(struct page
*page
,
1998 enum mem_cgroup_page_stat_item idx
, int val
)
2000 struct mem_cgroup
*memcg
;
2001 struct page_cgroup
*pc
= lookup_page_cgroup(page
);
2002 unsigned long uninitialized_var(flags
);
2004 if (mem_cgroup_disabled())
2007 memcg
= pc
->mem_cgroup
;
2008 if (unlikely(!memcg
|| !PageCgroupUsed(pc
)))
2012 case MEMCG_NR_FILE_MAPPED
:
2013 idx
= MEM_CGROUP_STAT_FILE_MAPPED
;
2019 this_cpu_add(memcg
->stat
->count
[idx
], val
);
2023 * size of first charge trial. "32" comes from vmscan.c's magic value.
2024 * TODO: maybe necessary to use big numbers in big irons.
2026 #define CHARGE_BATCH 32U
2027 struct memcg_stock_pcp
{
2028 struct mem_cgroup
*cached
; /* this never be root cgroup */
2029 unsigned int nr_pages
;
2030 struct work_struct work
;
2031 unsigned long flags
;
2032 #define FLUSHING_CACHED_CHARGE 0
2034 static DEFINE_PER_CPU(struct memcg_stock_pcp
, memcg_stock
);
2035 static DEFINE_MUTEX(percpu_charge_mutex
);
2038 * Try to consume stocked charge on this cpu. If success, one page is consumed
2039 * from local stock and true is returned. If the stock is 0 or charges from a
2040 * cgroup which is not current target, returns false. This stock will be
2043 static bool consume_stock(struct mem_cgroup
*memcg
)
2045 struct memcg_stock_pcp
*stock
;
2048 stock
= &get_cpu_var(memcg_stock
);
2049 if (memcg
== stock
->cached
&& stock
->nr_pages
)
2051 else /* need to call res_counter_charge */
2053 put_cpu_var(memcg_stock
);
2058 * Returns stocks cached in percpu to res_counter and reset cached information.
2060 static void drain_stock(struct memcg_stock_pcp
*stock
)
2062 struct mem_cgroup
*old
= stock
->cached
;
2064 if (stock
->nr_pages
) {
2065 unsigned long bytes
= stock
->nr_pages
* PAGE_SIZE
;
2067 res_counter_uncharge(&old
->res
, bytes
);
2068 if (do_swap_account
)
2069 res_counter_uncharge(&old
->memsw
, bytes
);
2070 stock
->nr_pages
= 0;
2072 stock
->cached
= NULL
;
2076 * This must be called under preempt disabled or must be called by
2077 * a thread which is pinned to local cpu.
2079 static void drain_local_stock(struct work_struct
*dummy
)
2081 struct memcg_stock_pcp
*stock
= &__get_cpu_var(memcg_stock
);
2083 clear_bit(FLUSHING_CACHED_CHARGE
, &stock
->flags
);
2087 * Cache charges(val) which is from res_counter, to local per_cpu area.
2088 * This will be consumed by consume_stock() function, later.
2090 static void refill_stock(struct mem_cgroup
*memcg
, unsigned int nr_pages
)
2092 struct memcg_stock_pcp
*stock
= &get_cpu_var(memcg_stock
);
2094 if (stock
->cached
!= memcg
) { /* reset if necessary */
2096 stock
->cached
= memcg
;
2098 stock
->nr_pages
+= nr_pages
;
2099 put_cpu_var(memcg_stock
);
2103 * Drains all per-CPU charge caches for given root_memcg resp. subtree
2104 * of the hierarchy under it. sync flag says whether we should block
2105 * until the work is done.
2107 static void drain_all_stock(struct mem_cgroup
*root_memcg
, bool sync
)
2111 /* Notify other cpus that system-wide "drain" is running */
2114 for_each_online_cpu(cpu
) {
2115 struct memcg_stock_pcp
*stock
= &per_cpu(memcg_stock
, cpu
);
2116 struct mem_cgroup
*memcg
;
2118 memcg
= stock
->cached
;
2119 if (!memcg
|| !stock
->nr_pages
)
2121 if (!mem_cgroup_same_or_subtree(root_memcg
, memcg
))
2123 if (!test_and_set_bit(FLUSHING_CACHED_CHARGE
, &stock
->flags
)) {
2125 drain_local_stock(&stock
->work
);
2127 schedule_work_on(cpu
, &stock
->work
);
2135 for_each_online_cpu(cpu
) {
2136 struct memcg_stock_pcp
*stock
= &per_cpu(memcg_stock
, cpu
);
2137 if (test_bit(FLUSHING_CACHED_CHARGE
, &stock
->flags
))
2138 flush_work(&stock
->work
);
2145 * Tries to drain stocked charges in other cpus. This function is asynchronous
2146 * and just put a work per cpu for draining localy on each cpu. Caller can
2147 * expects some charges will be back to res_counter later but cannot wait for
2150 static void drain_all_stock_async(struct mem_cgroup
*root_memcg
)
2153 * If someone calls draining, avoid adding more kworker runs.
2155 if (!mutex_trylock(&percpu_charge_mutex
))
2157 drain_all_stock(root_memcg
, false);
2158 mutex_unlock(&percpu_charge_mutex
);
2161 /* This is a synchronous drain interface. */
2162 static void drain_all_stock_sync(struct mem_cgroup
*root_memcg
)
2164 /* called when force_empty is called */
2165 mutex_lock(&percpu_charge_mutex
);
2166 drain_all_stock(root_memcg
, true);
2167 mutex_unlock(&percpu_charge_mutex
);
2171 * This function drains percpu counter value from DEAD cpu and
2172 * move it to local cpu. Note that this function can be preempted.
2174 static void mem_cgroup_drain_pcp_counter(struct mem_cgroup
*memcg
, int cpu
)
2178 spin_lock(&memcg
->pcp_counter_lock
);
2179 for (i
= 0; i
< MEM_CGROUP_STAT_NSTATS
; i
++) {
2180 long x
= per_cpu(memcg
->stat
->count
[i
], cpu
);
2182 per_cpu(memcg
->stat
->count
[i
], cpu
) = 0;
2183 memcg
->nocpu_base
.count
[i
] += x
;
2185 for (i
= 0; i
< MEM_CGROUP_EVENTS_NSTATS
; i
++) {
2186 unsigned long x
= per_cpu(memcg
->stat
->events
[i
], cpu
);
2188 per_cpu(memcg
->stat
->events
[i
], cpu
) = 0;
2189 memcg
->nocpu_base
.events
[i
] += x
;
2191 spin_unlock(&memcg
->pcp_counter_lock
);
2194 static int __cpuinit
memcg_cpu_hotplug_callback(struct notifier_block
*nb
,
2195 unsigned long action
,
2198 int cpu
= (unsigned long)hcpu
;
2199 struct memcg_stock_pcp
*stock
;
2200 struct mem_cgroup
*iter
;
2202 if (action
== CPU_ONLINE
)
2205 if (action
!= CPU_DEAD
&& action
!= CPU_DEAD_FROZEN
)
2208 for_each_mem_cgroup(iter
)
2209 mem_cgroup_drain_pcp_counter(iter
, cpu
);
2211 stock
= &per_cpu(memcg_stock
, cpu
);
2217 /* See __mem_cgroup_try_charge() for details */
2219 CHARGE_OK
, /* success */
2220 CHARGE_RETRY
, /* need to retry but retry is not bad */
2221 CHARGE_NOMEM
, /* we can't do more. return -ENOMEM */
2222 CHARGE_WOULDBLOCK
, /* GFP_WAIT wasn't set and no enough res. */
2223 CHARGE_OOM_DIE
, /* the current is killed because of OOM */
2226 static int mem_cgroup_do_charge(struct mem_cgroup
*memcg
, gfp_t gfp_mask
,
2227 unsigned int nr_pages
, bool oom_check
)
2229 unsigned long csize
= nr_pages
* PAGE_SIZE
;
2230 struct mem_cgroup
*mem_over_limit
;
2231 struct res_counter
*fail_res
;
2232 unsigned long flags
= 0;
2235 ret
= res_counter_charge(&memcg
->res
, csize
, &fail_res
);
2238 if (!do_swap_account
)
2240 ret
= res_counter_charge(&memcg
->memsw
, csize
, &fail_res
);
2244 res_counter_uncharge(&memcg
->res
, csize
);
2245 mem_over_limit
= mem_cgroup_from_res_counter(fail_res
, memsw
);
2246 flags
|= MEM_CGROUP_RECLAIM_NOSWAP
;
2248 mem_over_limit
= mem_cgroup_from_res_counter(fail_res
, res
);
2250 * nr_pages can be either a huge page (HPAGE_PMD_NR), a batch
2251 * of regular pages (CHARGE_BATCH), or a single regular page (1).
2253 * Never reclaim on behalf of optional batching, retry with a
2254 * single page instead.
2256 if (nr_pages
== CHARGE_BATCH
)
2257 return CHARGE_RETRY
;
2259 if (!(gfp_mask
& __GFP_WAIT
))
2260 return CHARGE_WOULDBLOCK
;
2262 ret
= mem_cgroup_reclaim(mem_over_limit
, gfp_mask
, flags
);
2263 if (mem_cgroup_margin(mem_over_limit
) >= nr_pages
)
2264 return CHARGE_RETRY
;
2266 * Even though the limit is exceeded at this point, reclaim
2267 * may have been able to free some pages. Retry the charge
2268 * before killing the task.
2270 * Only for regular pages, though: huge pages are rather
2271 * unlikely to succeed so close to the limit, and we fall back
2272 * to regular pages anyway in case of failure.
2274 if (nr_pages
== 1 && ret
)
2275 return CHARGE_RETRY
;
2278 * At task move, charge accounts can be doubly counted. So, it's
2279 * better to wait until the end of task_move if something is going on.
2281 if (mem_cgroup_wait_acct_move(mem_over_limit
))
2282 return CHARGE_RETRY
;
2284 /* If we don't need to call oom-killer at el, return immediately */
2286 return CHARGE_NOMEM
;
2288 if (!mem_cgroup_handle_oom(mem_over_limit
, gfp_mask
, get_order(csize
)))
2289 return CHARGE_OOM_DIE
;
2291 return CHARGE_RETRY
;
2295 * __mem_cgroup_try_charge() does
2296 * 1. detect memcg to be charged against from passed *mm and *ptr,
2297 * 2. update res_counter
2298 * 3. call memory reclaim if necessary.
2300 * In some special case, if the task is fatal, fatal_signal_pending() or
2301 * has TIF_MEMDIE, this function returns -EINTR while writing root_mem_cgroup
2302 * to *ptr. There are two reasons for this. 1: fatal threads should quit as soon
2303 * as possible without any hazards. 2: all pages should have a valid
2304 * pc->mem_cgroup. If mm is NULL and the caller doesn't pass a valid memcg
2305 * pointer, that is treated as a charge to root_mem_cgroup.
2307 * So __mem_cgroup_try_charge() will return
2308 * 0 ... on success, filling *ptr with a valid memcg pointer.
2309 * -ENOMEM ... charge failure because of resource limits.
2310 * -EINTR ... if thread is fatal. *ptr is filled with root_mem_cgroup.
2312 * Unlike the exported interface, an "oom" parameter is added. if oom==true,
2313 * the oom-killer can be invoked.
2315 static int __mem_cgroup_try_charge(struct mm_struct
*mm
,
2317 unsigned int nr_pages
,
2318 struct mem_cgroup
**ptr
,
2321 unsigned int batch
= max(CHARGE_BATCH
, nr_pages
);
2322 int nr_oom_retries
= MEM_CGROUP_RECLAIM_RETRIES
;
2323 struct mem_cgroup
*memcg
= NULL
;
2327 * Unlike gloval-vm's OOM-kill, we're not in memory shortage
2328 * in system level. So, allow to go ahead dying process in addition to
2331 if (unlikely(test_thread_flag(TIF_MEMDIE
)
2332 || fatal_signal_pending(current
)))
2336 * We always charge the cgroup the mm_struct belongs to.
2337 * The mm_struct's mem_cgroup changes on task migration if the
2338 * thread group leader migrates. It's possible that mm is not
2339 * set, if so charge the root memcg (happens for pagecache usage).
2342 *ptr
= root_mem_cgroup
;
2344 if (*ptr
) { /* css should be a valid one */
2346 if (mem_cgroup_is_root(memcg
))
2348 if (nr_pages
== 1 && consume_stock(memcg
))
2350 css_get(&memcg
->css
);
2352 struct task_struct
*p
;
2355 p
= rcu_dereference(mm
->owner
);
2357 * Because we don't have task_lock(), "p" can exit.
2358 * In that case, "memcg" can point to root or p can be NULL with
2359 * race with swapoff. Then, we have small risk of mis-accouning.
2360 * But such kind of mis-account by race always happens because
2361 * we don't have cgroup_mutex(). It's overkill and we allo that
2363 * (*) swapoff at el will charge against mm-struct not against
2364 * task-struct. So, mm->owner can be NULL.
2366 memcg
= mem_cgroup_from_task(p
);
2368 memcg
= root_mem_cgroup
;
2369 if (mem_cgroup_is_root(memcg
)) {
2373 if (nr_pages
== 1 && consume_stock(memcg
)) {
2375 * It seems dagerous to access memcg without css_get().
2376 * But considering how consume_stok works, it's not
2377 * necessary. If consume_stock success, some charges
2378 * from this memcg are cached on this cpu. So, we
2379 * don't need to call css_get()/css_tryget() before
2380 * calling consume_stock().
2385 /* after here, we may be blocked. we need to get refcnt */
2386 if (!css_tryget(&memcg
->css
)) {
2396 /* If killed, bypass charge */
2397 if (fatal_signal_pending(current
)) {
2398 css_put(&memcg
->css
);
2403 if (oom
&& !nr_oom_retries
) {
2405 nr_oom_retries
= MEM_CGROUP_RECLAIM_RETRIES
;
2408 ret
= mem_cgroup_do_charge(memcg
, gfp_mask
, batch
, oom_check
);
2412 case CHARGE_RETRY
: /* not in OOM situation but retry */
2414 css_put(&memcg
->css
);
2417 case CHARGE_WOULDBLOCK
: /* !__GFP_WAIT */
2418 css_put(&memcg
->css
);
2420 case CHARGE_NOMEM
: /* OOM routine works */
2422 css_put(&memcg
->css
);
2425 /* If oom, we never return -ENOMEM */
2428 case CHARGE_OOM_DIE
: /* Killed by OOM Killer */
2429 css_put(&memcg
->css
);
2432 } while (ret
!= CHARGE_OK
);
2434 if (batch
> nr_pages
)
2435 refill_stock(memcg
, batch
- nr_pages
);
2436 css_put(&memcg
->css
);
2444 *ptr
= root_mem_cgroup
;
2449 * Somemtimes we have to undo a charge we got by try_charge().
2450 * This function is for that and do uncharge, put css's refcnt.
2451 * gotten by try_charge().
2453 static void __mem_cgroup_cancel_charge(struct mem_cgroup
*memcg
,
2454 unsigned int nr_pages
)
2456 if (!mem_cgroup_is_root(memcg
)) {
2457 unsigned long bytes
= nr_pages
* PAGE_SIZE
;
2459 res_counter_uncharge(&memcg
->res
, bytes
);
2460 if (do_swap_account
)
2461 res_counter_uncharge(&memcg
->memsw
, bytes
);
2466 * Cancel chrages in this cgroup....doesn't propagate to parent cgroup.
2467 * This is useful when moving usage to parent cgroup.
2469 static void __mem_cgroup_cancel_local_charge(struct mem_cgroup
*memcg
,
2470 unsigned int nr_pages
)
2472 unsigned long bytes
= nr_pages
* PAGE_SIZE
;
2474 if (mem_cgroup_is_root(memcg
))
2477 res_counter_uncharge_until(&memcg
->res
, memcg
->res
.parent
, bytes
);
2478 if (do_swap_account
)
2479 res_counter_uncharge_until(&memcg
->memsw
,
2480 memcg
->memsw
.parent
, bytes
);
2484 * A helper function to get mem_cgroup from ID. must be called under
2485 * rcu_read_lock(). The caller is responsible for calling css_tryget if
2486 * the mem_cgroup is used for charging. (dropping refcnt from swap can be
2487 * called against removed memcg.)
2489 static struct mem_cgroup
*mem_cgroup_lookup(unsigned short id
)
2491 struct cgroup_subsys_state
*css
;
2493 /* ID 0 is unused ID */
2496 css
= css_lookup(&mem_cgroup_subsys
, id
);
2499 return mem_cgroup_from_css(css
);
2502 struct mem_cgroup
*try_get_mem_cgroup_from_page(struct page
*page
)
2504 struct mem_cgroup
*memcg
= NULL
;
2505 struct page_cgroup
*pc
;
2509 VM_BUG_ON(!PageLocked(page
));
2511 pc
= lookup_page_cgroup(page
);
2512 lock_page_cgroup(pc
);
2513 if (PageCgroupUsed(pc
)) {
2514 memcg
= pc
->mem_cgroup
;
2515 if (memcg
&& !css_tryget(&memcg
->css
))
2517 } else if (PageSwapCache(page
)) {
2518 ent
.val
= page_private(page
);
2519 id
= lookup_swap_cgroup_id(ent
);
2521 memcg
= mem_cgroup_lookup(id
);
2522 if (memcg
&& !css_tryget(&memcg
->css
))
2526 unlock_page_cgroup(pc
);
2530 static void __mem_cgroup_commit_charge(struct mem_cgroup
*memcg
,
2532 unsigned int nr_pages
,
2533 enum charge_type ctype
,
2536 struct page_cgroup
*pc
= lookup_page_cgroup(page
);
2537 struct zone
*uninitialized_var(zone
);
2538 struct lruvec
*lruvec
;
2539 bool was_on_lru
= false;
2542 lock_page_cgroup(pc
);
2543 VM_BUG_ON(PageCgroupUsed(pc
));
2545 * we don't need page_cgroup_lock about tail pages, becase they are not
2546 * accessed by any other context at this point.
2550 * In some cases, SwapCache and FUSE(splice_buf->radixtree), the page
2551 * may already be on some other mem_cgroup's LRU. Take care of it.
2554 zone
= page_zone(page
);
2555 spin_lock_irq(&zone
->lru_lock
);
2556 if (PageLRU(page
)) {
2557 lruvec
= mem_cgroup_zone_lruvec(zone
, pc
->mem_cgroup
);
2559 del_page_from_lru_list(page
, lruvec
, page_lru(page
));
2564 pc
->mem_cgroup
= memcg
;
2566 * We access a page_cgroup asynchronously without lock_page_cgroup().
2567 * Especially when a page_cgroup is taken from a page, pc->mem_cgroup
2568 * is accessed after testing USED bit. To make pc->mem_cgroup visible
2569 * before USED bit, we need memory barrier here.
2570 * See mem_cgroup_add_lru_list(), etc.
2573 SetPageCgroupUsed(pc
);
2577 lruvec
= mem_cgroup_zone_lruvec(zone
, pc
->mem_cgroup
);
2578 VM_BUG_ON(PageLRU(page
));
2580 add_page_to_lru_list(page
, lruvec
, page_lru(page
));
2582 spin_unlock_irq(&zone
->lru_lock
);
2585 if (ctype
== MEM_CGROUP_CHARGE_TYPE_ANON
)
2590 mem_cgroup_charge_statistics(memcg
, anon
, nr_pages
);
2591 unlock_page_cgroup(pc
);
2594 * "charge_statistics" updated event counter. Then, check it.
2595 * Insert ancestor (and ancestor's ancestors), to softlimit RB-tree.
2596 * if they exceeds softlimit.
2598 memcg_check_events(memcg
, page
);
2601 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
2603 #define PCGF_NOCOPY_AT_SPLIT (1 << PCG_LOCK | 1 << PCG_MIGRATION)
2605 * Because tail pages are not marked as "used", set it. We're under
2606 * zone->lru_lock, 'splitting on pmd' and compound_lock.
2607 * charge/uncharge will be never happen and move_account() is done under
2608 * compound_lock(), so we don't have to take care of races.
2610 void mem_cgroup_split_huge_fixup(struct page
*head
)
2612 struct page_cgroup
*head_pc
= lookup_page_cgroup(head
);
2613 struct page_cgroup
*pc
;
2616 if (mem_cgroup_disabled())
2618 for (i
= 1; i
< HPAGE_PMD_NR
; i
++) {
2620 pc
->mem_cgroup
= head_pc
->mem_cgroup
;
2621 smp_wmb();/* see __commit_charge() */
2622 pc
->flags
= head_pc
->flags
& ~PCGF_NOCOPY_AT_SPLIT
;
2625 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
2628 * mem_cgroup_move_account - move account of the page
2630 * @nr_pages: number of regular pages (>1 for huge pages)
2631 * @pc: page_cgroup of the page.
2632 * @from: mem_cgroup which the page is moved from.
2633 * @to: mem_cgroup which the page is moved to. @from != @to.
2635 * The caller must confirm following.
2636 * - page is not on LRU (isolate_page() is useful.)
2637 * - compound_lock is held when nr_pages > 1
2639 * This function doesn't do "charge" to new cgroup and doesn't do "uncharge"
2642 static int mem_cgroup_move_account(struct page
*page
,
2643 unsigned int nr_pages
,
2644 struct page_cgroup
*pc
,
2645 struct mem_cgroup
*from
,
2646 struct mem_cgroup
*to
)
2648 unsigned long flags
;
2650 bool anon
= PageAnon(page
);
2652 VM_BUG_ON(from
== to
);
2653 VM_BUG_ON(PageLRU(page
));
2655 * The page is isolated from LRU. So, collapse function
2656 * will not handle this page. But page splitting can happen.
2657 * Do this check under compound_page_lock(). The caller should
2661 if (nr_pages
> 1 && !PageTransHuge(page
))
2664 lock_page_cgroup(pc
);
2667 if (!PageCgroupUsed(pc
) || pc
->mem_cgroup
!= from
)
2670 move_lock_mem_cgroup(from
, &flags
);
2672 if (!anon
&& page_mapped(page
)) {
2673 /* Update mapped_file data for mem_cgroup */
2675 __this_cpu_dec(from
->stat
->count
[MEM_CGROUP_STAT_FILE_MAPPED
]);
2676 __this_cpu_inc(to
->stat
->count
[MEM_CGROUP_STAT_FILE_MAPPED
]);
2679 mem_cgroup_charge_statistics(from
, anon
, -nr_pages
);
2681 /* caller should have done css_get */
2682 pc
->mem_cgroup
= to
;
2683 mem_cgroup_charge_statistics(to
, anon
, nr_pages
);
2684 move_unlock_mem_cgroup(from
, &flags
);
2687 unlock_page_cgroup(pc
);
2691 memcg_check_events(to
, page
);
2692 memcg_check_events(from
, page
);
2698 * mem_cgroup_move_parent - moves page to the parent group
2699 * @page: the page to move
2700 * @pc: page_cgroup of the page
2701 * @child: page's cgroup
2703 * move charges to its parent or the root cgroup if the group has no
2704 * parent (aka use_hierarchy==0).
2705 * Although this might fail (get_page_unless_zero, isolate_lru_page or
2706 * mem_cgroup_move_account fails) the failure is always temporary and
2707 * it signals a race with a page removal/uncharge or migration. In the
2708 * first case the page is on the way out and it will vanish from the LRU
2709 * on the next attempt and the call should be retried later.
2710 * Isolation from the LRU fails only if page has been isolated from
2711 * the LRU since we looked at it and that usually means either global
2712 * reclaim or migration going on. The page will either get back to the
2714 * Finaly mem_cgroup_move_account fails only if the page got uncharged
2715 * (!PageCgroupUsed) or moved to a different group. The page will
2716 * disappear in the next attempt.
2718 static int mem_cgroup_move_parent(struct page
*page
,
2719 struct page_cgroup
*pc
,
2720 struct mem_cgroup
*child
)
2722 struct mem_cgroup
*parent
;
2723 unsigned int nr_pages
;
2724 unsigned long uninitialized_var(flags
);
2727 VM_BUG_ON(mem_cgroup_is_root(child
));
2730 if (!get_page_unless_zero(page
))
2732 if (isolate_lru_page(page
))
2735 nr_pages
= hpage_nr_pages(page
);
2737 parent
= parent_mem_cgroup(child
);
2739 * If no parent, move charges to root cgroup.
2742 parent
= root_mem_cgroup
;
2745 VM_BUG_ON(!PageTransHuge(page
));
2746 flags
= compound_lock_irqsave(page
);
2749 ret
= mem_cgroup_move_account(page
, nr_pages
,
2752 __mem_cgroup_cancel_local_charge(child
, nr_pages
);
2755 compound_unlock_irqrestore(page
, flags
);
2756 putback_lru_page(page
);
2764 * Charge the memory controller for page usage.
2766 * 0 if the charge was successful
2767 * < 0 if the cgroup is over its limit
2769 static int mem_cgroup_charge_common(struct page
*page
, struct mm_struct
*mm
,
2770 gfp_t gfp_mask
, enum charge_type ctype
)
2772 struct mem_cgroup
*memcg
= NULL
;
2773 unsigned int nr_pages
= 1;
2777 if (PageTransHuge(page
)) {
2778 nr_pages
<<= compound_order(page
);
2779 VM_BUG_ON(!PageTransHuge(page
));
2781 * Never OOM-kill a process for a huge page. The
2782 * fault handler will fall back to regular pages.
2787 ret
= __mem_cgroup_try_charge(mm
, gfp_mask
, nr_pages
, &memcg
, oom
);
2790 __mem_cgroup_commit_charge(memcg
, page
, nr_pages
, ctype
, false);
2794 int mem_cgroup_newpage_charge(struct page
*page
,
2795 struct mm_struct
*mm
, gfp_t gfp_mask
)
2797 if (mem_cgroup_disabled())
2799 VM_BUG_ON(page_mapped(page
));
2800 VM_BUG_ON(page
->mapping
&& !PageAnon(page
));
2802 return mem_cgroup_charge_common(page
, mm
, gfp_mask
,
2803 MEM_CGROUP_CHARGE_TYPE_ANON
);
2807 * While swap-in, try_charge -> commit or cancel, the page is locked.
2808 * And when try_charge() successfully returns, one refcnt to memcg without
2809 * struct page_cgroup is acquired. This refcnt will be consumed by
2810 * "commit()" or removed by "cancel()"
2812 static int __mem_cgroup_try_charge_swapin(struct mm_struct
*mm
,
2815 struct mem_cgroup
**memcgp
)
2817 struct mem_cgroup
*memcg
;
2818 struct page_cgroup
*pc
;
2821 pc
= lookup_page_cgroup(page
);
2823 * Every swap fault against a single page tries to charge the
2824 * page, bail as early as possible. shmem_unuse() encounters
2825 * already charged pages, too. The USED bit is protected by
2826 * the page lock, which serializes swap cache removal, which
2827 * in turn serializes uncharging.
2829 if (PageCgroupUsed(pc
))
2831 if (!do_swap_account
)
2833 memcg
= try_get_mem_cgroup_from_page(page
);
2837 ret
= __mem_cgroup_try_charge(NULL
, mask
, 1, memcgp
, true);
2838 css_put(&memcg
->css
);
2843 ret
= __mem_cgroup_try_charge(mm
, mask
, 1, memcgp
, true);
2849 int mem_cgroup_try_charge_swapin(struct mm_struct
*mm
, struct page
*page
,
2850 gfp_t gfp_mask
, struct mem_cgroup
**memcgp
)
2853 if (mem_cgroup_disabled())
2856 * A racing thread's fault, or swapoff, may have already
2857 * updated the pte, and even removed page from swap cache: in
2858 * those cases unuse_pte()'s pte_same() test will fail; but
2859 * there's also a KSM case which does need to charge the page.
2861 if (!PageSwapCache(page
)) {
2864 ret
= __mem_cgroup_try_charge(mm
, gfp_mask
, 1, memcgp
, true);
2869 return __mem_cgroup_try_charge_swapin(mm
, page
, gfp_mask
, memcgp
);
2872 void mem_cgroup_cancel_charge_swapin(struct mem_cgroup
*memcg
)
2874 if (mem_cgroup_disabled())
2878 __mem_cgroup_cancel_charge(memcg
, 1);
2882 __mem_cgroup_commit_charge_swapin(struct page
*page
, struct mem_cgroup
*memcg
,
2883 enum charge_type ctype
)
2885 if (mem_cgroup_disabled())
2890 __mem_cgroup_commit_charge(memcg
, page
, 1, ctype
, true);
2892 * Now swap is on-memory. This means this page may be
2893 * counted both as mem and swap....double count.
2894 * Fix it by uncharging from memsw. Basically, this SwapCache is stable
2895 * under lock_page(). But in do_swap_page()::memory.c, reuse_swap_page()
2896 * may call delete_from_swap_cache() before reach here.
2898 if (do_swap_account
&& PageSwapCache(page
)) {
2899 swp_entry_t ent
= {.val
= page_private(page
)};
2900 mem_cgroup_uncharge_swap(ent
);
2904 void mem_cgroup_commit_charge_swapin(struct page
*page
,
2905 struct mem_cgroup
*memcg
)
2907 __mem_cgroup_commit_charge_swapin(page
, memcg
,
2908 MEM_CGROUP_CHARGE_TYPE_ANON
);
2911 int mem_cgroup_cache_charge(struct page
*page
, struct mm_struct
*mm
,
2914 struct mem_cgroup
*memcg
= NULL
;
2915 enum charge_type type
= MEM_CGROUP_CHARGE_TYPE_CACHE
;
2918 if (mem_cgroup_disabled())
2920 if (PageCompound(page
))
2923 if (!PageSwapCache(page
))
2924 ret
= mem_cgroup_charge_common(page
, mm
, gfp_mask
, type
);
2925 else { /* page is swapcache/shmem */
2926 ret
= __mem_cgroup_try_charge_swapin(mm
, page
,
2929 __mem_cgroup_commit_charge_swapin(page
, memcg
, type
);
2934 static void mem_cgroup_do_uncharge(struct mem_cgroup
*memcg
,
2935 unsigned int nr_pages
,
2936 const enum charge_type ctype
)
2938 struct memcg_batch_info
*batch
= NULL
;
2939 bool uncharge_memsw
= true;
2941 /* If swapout, usage of swap doesn't decrease */
2942 if (!do_swap_account
|| ctype
== MEM_CGROUP_CHARGE_TYPE_SWAPOUT
)
2943 uncharge_memsw
= false;
2945 batch
= ¤t
->memcg_batch
;
2947 * In usual, we do css_get() when we remember memcg pointer.
2948 * But in this case, we keep res->usage until end of a series of
2949 * uncharges. Then, it's ok to ignore memcg's refcnt.
2952 batch
->memcg
= memcg
;
2954 * do_batch > 0 when unmapping pages or inode invalidate/truncate.
2955 * In those cases, all pages freed continuously can be expected to be in
2956 * the same cgroup and we have chance to coalesce uncharges.
2957 * But we do uncharge one by one if this is killed by OOM(TIF_MEMDIE)
2958 * because we want to do uncharge as soon as possible.
2961 if (!batch
->do_batch
|| test_thread_flag(TIF_MEMDIE
))
2962 goto direct_uncharge
;
2965 goto direct_uncharge
;
2968 * In typical case, batch->memcg == mem. This means we can
2969 * merge a series of uncharges to an uncharge of res_counter.
2970 * If not, we uncharge res_counter ony by one.
2972 if (batch
->memcg
!= memcg
)
2973 goto direct_uncharge
;
2974 /* remember freed charge and uncharge it later */
2977 batch
->memsw_nr_pages
++;
2980 res_counter_uncharge(&memcg
->res
, nr_pages
* PAGE_SIZE
);
2982 res_counter_uncharge(&memcg
->memsw
, nr_pages
* PAGE_SIZE
);
2983 if (unlikely(batch
->memcg
!= memcg
))
2984 memcg_oom_recover(memcg
);
2988 * uncharge if !page_mapped(page)
2990 static struct mem_cgroup
*
2991 __mem_cgroup_uncharge_common(struct page
*page
, enum charge_type ctype
,
2994 struct mem_cgroup
*memcg
= NULL
;
2995 unsigned int nr_pages
= 1;
2996 struct page_cgroup
*pc
;
2999 if (mem_cgroup_disabled())
3002 VM_BUG_ON(PageSwapCache(page
));
3004 if (PageTransHuge(page
)) {
3005 nr_pages
<<= compound_order(page
);
3006 VM_BUG_ON(!PageTransHuge(page
));
3009 * Check if our page_cgroup is valid
3011 pc
= lookup_page_cgroup(page
);
3012 if (unlikely(!PageCgroupUsed(pc
)))
3015 lock_page_cgroup(pc
);
3017 memcg
= pc
->mem_cgroup
;
3019 if (!PageCgroupUsed(pc
))
3022 anon
= PageAnon(page
);
3025 case MEM_CGROUP_CHARGE_TYPE_ANON
:
3027 * Generally PageAnon tells if it's the anon statistics to be
3028 * updated; but sometimes e.g. mem_cgroup_uncharge_page() is
3029 * used before page reached the stage of being marked PageAnon.
3033 case MEM_CGROUP_CHARGE_TYPE_DROP
:
3034 /* See mem_cgroup_prepare_migration() */
3035 if (page_mapped(page
))
3038 * Pages under migration may not be uncharged. But
3039 * end_migration() /must/ be the one uncharging the
3040 * unused post-migration page and so it has to call
3041 * here with the migration bit still set. See the
3042 * res_counter handling below.
3044 if (!end_migration
&& PageCgroupMigration(pc
))
3047 case MEM_CGROUP_CHARGE_TYPE_SWAPOUT
:
3048 if (!PageAnon(page
)) { /* Shared memory */
3049 if (page
->mapping
&& !page_is_file_cache(page
))
3051 } else if (page_mapped(page
)) /* Anon */
3058 mem_cgroup_charge_statistics(memcg
, anon
, -nr_pages
);
3060 ClearPageCgroupUsed(pc
);
3062 * pc->mem_cgroup is not cleared here. It will be accessed when it's
3063 * freed from LRU. This is safe because uncharged page is expected not
3064 * to be reused (freed soon). Exception is SwapCache, it's handled by
3065 * special functions.
3068 unlock_page_cgroup(pc
);
3070 * even after unlock, we have memcg->res.usage here and this memcg
3071 * will never be freed.
3073 memcg_check_events(memcg
, page
);
3074 if (do_swap_account
&& ctype
== MEM_CGROUP_CHARGE_TYPE_SWAPOUT
) {
3075 mem_cgroup_swap_statistics(memcg
, true);
3076 mem_cgroup_get(memcg
);
3079 * Migration does not charge the res_counter for the
3080 * replacement page, so leave it alone when phasing out the
3081 * page that is unused after the migration.
3083 if (!end_migration
&& !mem_cgroup_is_root(memcg
))
3084 mem_cgroup_do_uncharge(memcg
, nr_pages
, ctype
);
3089 unlock_page_cgroup(pc
);
3093 void mem_cgroup_uncharge_page(struct page
*page
)
3096 if (page_mapped(page
))
3098 VM_BUG_ON(page
->mapping
&& !PageAnon(page
));
3099 if (PageSwapCache(page
))
3101 __mem_cgroup_uncharge_common(page
, MEM_CGROUP_CHARGE_TYPE_ANON
, false);
3104 void mem_cgroup_uncharge_cache_page(struct page
*page
)
3106 VM_BUG_ON(page_mapped(page
));
3107 VM_BUG_ON(page
->mapping
);
3108 __mem_cgroup_uncharge_common(page
, MEM_CGROUP_CHARGE_TYPE_CACHE
, false);
3112 * Batch_start/batch_end is called in unmap_page_range/invlidate/trucate.
3113 * In that cases, pages are freed continuously and we can expect pages
3114 * are in the same memcg. All these calls itself limits the number of
3115 * pages freed at once, then uncharge_start/end() is called properly.
3116 * This may be called prural(2) times in a context,
3119 void mem_cgroup_uncharge_start(void)
3121 current
->memcg_batch
.do_batch
++;
3122 /* We can do nest. */
3123 if (current
->memcg_batch
.do_batch
== 1) {
3124 current
->memcg_batch
.memcg
= NULL
;
3125 current
->memcg_batch
.nr_pages
= 0;
3126 current
->memcg_batch
.memsw_nr_pages
= 0;
3130 void mem_cgroup_uncharge_end(void)
3132 struct memcg_batch_info
*batch
= ¤t
->memcg_batch
;
3134 if (!batch
->do_batch
)
3138 if (batch
->do_batch
) /* If stacked, do nothing. */
3144 * This "batch->memcg" is valid without any css_get/put etc...
3145 * bacause we hide charges behind us.
3147 if (batch
->nr_pages
)
3148 res_counter_uncharge(&batch
->memcg
->res
,
3149 batch
->nr_pages
* PAGE_SIZE
);
3150 if (batch
->memsw_nr_pages
)
3151 res_counter_uncharge(&batch
->memcg
->memsw
,
3152 batch
->memsw_nr_pages
* PAGE_SIZE
);
3153 memcg_oom_recover(batch
->memcg
);
3154 /* forget this pointer (for sanity check) */
3155 batch
->memcg
= NULL
;
3160 * called after __delete_from_swap_cache() and drop "page" account.
3161 * memcg information is recorded to swap_cgroup of "ent"
3164 mem_cgroup_uncharge_swapcache(struct page
*page
, swp_entry_t ent
, bool swapout
)
3166 struct mem_cgroup
*memcg
;
3167 int ctype
= MEM_CGROUP_CHARGE_TYPE_SWAPOUT
;
3169 if (!swapout
) /* this was a swap cache but the swap is unused ! */
3170 ctype
= MEM_CGROUP_CHARGE_TYPE_DROP
;
3172 memcg
= __mem_cgroup_uncharge_common(page
, ctype
, false);
3175 * record memcg information, if swapout && memcg != NULL,
3176 * mem_cgroup_get() was called in uncharge().
3178 if (do_swap_account
&& swapout
&& memcg
)
3179 swap_cgroup_record(ent
, css_id(&memcg
->css
));
3183 #ifdef CONFIG_MEMCG_SWAP
3185 * called from swap_entry_free(). remove record in swap_cgroup and
3186 * uncharge "memsw" account.
3188 void mem_cgroup_uncharge_swap(swp_entry_t ent
)
3190 struct mem_cgroup
*memcg
;
3193 if (!do_swap_account
)
3196 id
= swap_cgroup_record(ent
, 0);
3198 memcg
= mem_cgroup_lookup(id
);
3201 * We uncharge this because swap is freed.
3202 * This memcg can be obsolete one. We avoid calling css_tryget
3204 if (!mem_cgroup_is_root(memcg
))
3205 res_counter_uncharge(&memcg
->memsw
, PAGE_SIZE
);
3206 mem_cgroup_swap_statistics(memcg
, false);
3207 mem_cgroup_put(memcg
);
3213 * mem_cgroup_move_swap_account - move swap charge and swap_cgroup's record.
3214 * @entry: swap entry to be moved
3215 * @from: mem_cgroup which the entry is moved from
3216 * @to: mem_cgroup which the entry is moved to
3218 * It succeeds only when the swap_cgroup's record for this entry is the same
3219 * as the mem_cgroup's id of @from.
3221 * Returns 0 on success, -EINVAL on failure.
3223 * The caller must have charged to @to, IOW, called res_counter_charge() about
3224 * both res and memsw, and called css_get().
3226 static int mem_cgroup_move_swap_account(swp_entry_t entry
,
3227 struct mem_cgroup
*from
, struct mem_cgroup
*to
)
3229 unsigned short old_id
, new_id
;
3231 old_id
= css_id(&from
->css
);
3232 new_id
= css_id(&to
->css
);
3234 if (swap_cgroup_cmpxchg(entry
, old_id
, new_id
) == old_id
) {
3235 mem_cgroup_swap_statistics(from
, false);
3236 mem_cgroup_swap_statistics(to
, true);
3238 * This function is only called from task migration context now.
3239 * It postpones res_counter and refcount handling till the end
3240 * of task migration(mem_cgroup_clear_mc()) for performance
3241 * improvement. But we cannot postpone mem_cgroup_get(to)
3242 * because if the process that has been moved to @to does
3243 * swap-in, the refcount of @to might be decreased to 0.
3251 static inline int mem_cgroup_move_swap_account(swp_entry_t entry
,
3252 struct mem_cgroup
*from
, struct mem_cgroup
*to
)
3259 * Before starting migration, account PAGE_SIZE to mem_cgroup that the old
3262 void mem_cgroup_prepare_migration(struct page
*page
, struct page
*newpage
,
3263 struct mem_cgroup
**memcgp
)
3265 struct mem_cgroup
*memcg
= NULL
;
3266 struct page_cgroup
*pc
;
3267 enum charge_type ctype
;
3271 VM_BUG_ON(PageTransHuge(page
));
3272 if (mem_cgroup_disabled())
3275 pc
= lookup_page_cgroup(page
);
3276 lock_page_cgroup(pc
);
3277 if (PageCgroupUsed(pc
)) {
3278 memcg
= pc
->mem_cgroup
;
3279 css_get(&memcg
->css
);
3281 * At migrating an anonymous page, its mapcount goes down
3282 * to 0 and uncharge() will be called. But, even if it's fully
3283 * unmapped, migration may fail and this page has to be
3284 * charged again. We set MIGRATION flag here and delay uncharge
3285 * until end_migration() is called
3287 * Corner Case Thinking
3289 * When the old page was mapped as Anon and it's unmap-and-freed
3290 * while migration was ongoing.
3291 * If unmap finds the old page, uncharge() of it will be delayed
3292 * until end_migration(). If unmap finds a new page, it's
3293 * uncharged when it make mapcount to be 1->0. If unmap code
3294 * finds swap_migration_entry, the new page will not be mapped
3295 * and end_migration() will find it(mapcount==0).
3298 * When the old page was mapped but migraion fails, the kernel
3299 * remaps it. A charge for it is kept by MIGRATION flag even
3300 * if mapcount goes down to 0. We can do remap successfully
3301 * without charging it again.
3304 * The "old" page is under lock_page() until the end of
3305 * migration, so, the old page itself will not be swapped-out.
3306 * If the new page is swapped out before end_migraton, our
3307 * hook to usual swap-out path will catch the event.
3310 SetPageCgroupMigration(pc
);
3312 unlock_page_cgroup(pc
);
3314 * If the page is not charged at this point,
3322 * We charge new page before it's used/mapped. So, even if unlock_page()
3323 * is called before end_migration, we can catch all events on this new
3324 * page. In the case new page is migrated but not remapped, new page's
3325 * mapcount will be finally 0 and we call uncharge in end_migration().
3328 ctype
= MEM_CGROUP_CHARGE_TYPE_ANON
;
3330 ctype
= MEM_CGROUP_CHARGE_TYPE_CACHE
;
3332 * The page is committed to the memcg, but it's not actually
3333 * charged to the res_counter since we plan on replacing the
3334 * old one and only one page is going to be left afterwards.
3336 __mem_cgroup_commit_charge(memcg
, newpage
, 1, ctype
, false);
3339 /* remove redundant charge if migration failed*/
3340 void mem_cgroup_end_migration(struct mem_cgroup
*memcg
,
3341 struct page
*oldpage
, struct page
*newpage
, bool migration_ok
)
3343 struct page
*used
, *unused
;
3344 struct page_cgroup
*pc
;
3350 if (!migration_ok
) {
3357 anon
= PageAnon(used
);
3358 __mem_cgroup_uncharge_common(unused
,
3359 anon
? MEM_CGROUP_CHARGE_TYPE_ANON
3360 : MEM_CGROUP_CHARGE_TYPE_CACHE
,
3362 css_put(&memcg
->css
);
3364 * We disallowed uncharge of pages under migration because mapcount
3365 * of the page goes down to zero, temporarly.
3366 * Clear the flag and check the page should be charged.
3368 pc
= lookup_page_cgroup(oldpage
);
3369 lock_page_cgroup(pc
);
3370 ClearPageCgroupMigration(pc
);
3371 unlock_page_cgroup(pc
);
3374 * If a page is a file cache, radix-tree replacement is very atomic
3375 * and we can skip this check. When it was an Anon page, its mapcount
3376 * goes down to 0. But because we added MIGRATION flage, it's not
3377 * uncharged yet. There are several case but page->mapcount check
3378 * and USED bit check in mem_cgroup_uncharge_page() will do enough
3379 * check. (see prepare_charge() also)
3382 mem_cgroup_uncharge_page(used
);
3386 * At replace page cache, newpage is not under any memcg but it's on
3387 * LRU. So, this function doesn't touch res_counter but handles LRU
3388 * in correct way. Both pages are locked so we cannot race with uncharge.
3390 void mem_cgroup_replace_page_cache(struct page
*oldpage
,
3391 struct page
*newpage
)
3393 struct mem_cgroup
*memcg
= NULL
;
3394 struct page_cgroup
*pc
;
3395 enum charge_type type
= MEM_CGROUP_CHARGE_TYPE_CACHE
;
3397 if (mem_cgroup_disabled())
3400 pc
= lookup_page_cgroup(oldpage
);
3401 /* fix accounting on old pages */
3402 lock_page_cgroup(pc
);
3403 if (PageCgroupUsed(pc
)) {
3404 memcg
= pc
->mem_cgroup
;
3405 mem_cgroup_charge_statistics(memcg
, false, -1);
3406 ClearPageCgroupUsed(pc
);
3408 unlock_page_cgroup(pc
);
3411 * When called from shmem_replace_page(), in some cases the
3412 * oldpage has already been charged, and in some cases not.
3417 * Even if newpage->mapping was NULL before starting replacement,
3418 * the newpage may be on LRU(or pagevec for LRU) already. We lock
3419 * LRU while we overwrite pc->mem_cgroup.
3421 __mem_cgroup_commit_charge(memcg
, newpage
, 1, type
, true);
3424 #ifdef CONFIG_DEBUG_VM
3425 static struct page_cgroup
*lookup_page_cgroup_used(struct page
*page
)
3427 struct page_cgroup
*pc
;
3429 pc
= lookup_page_cgroup(page
);
3431 * Can be NULL while feeding pages into the page allocator for
3432 * the first time, i.e. during boot or memory hotplug;
3433 * or when mem_cgroup_disabled().
3435 if (likely(pc
) && PageCgroupUsed(pc
))
3440 bool mem_cgroup_bad_page_check(struct page
*page
)
3442 if (mem_cgroup_disabled())
3445 return lookup_page_cgroup_used(page
) != NULL
;
3448 void mem_cgroup_print_bad_page(struct page
*page
)
3450 struct page_cgroup
*pc
;
3452 pc
= lookup_page_cgroup_used(page
);
3454 printk(KERN_ALERT
"pc:%p pc->flags:%lx pc->mem_cgroup:%p\n",
3455 pc
, pc
->flags
, pc
->mem_cgroup
);
3460 static DEFINE_MUTEX(set_limit_mutex
);
3462 static int mem_cgroup_resize_limit(struct mem_cgroup
*memcg
,
3463 unsigned long long val
)
3466 u64 memswlimit
, memlimit
;
3468 int children
= mem_cgroup_count_children(memcg
);
3469 u64 curusage
, oldusage
;
3473 * For keeping hierarchical_reclaim simple, how long we should retry
3474 * is depends on callers. We set our retry-count to be function
3475 * of # of children which we should visit in this loop.
3477 retry_count
= MEM_CGROUP_RECLAIM_RETRIES
* children
;
3479 oldusage
= res_counter_read_u64(&memcg
->res
, RES_USAGE
);
3482 while (retry_count
) {
3483 if (signal_pending(current
)) {
3488 * Rather than hide all in some function, I do this in
3489 * open coded manner. You see what this really does.
3490 * We have to guarantee memcg->res.limit <= memcg->memsw.limit.
3492 mutex_lock(&set_limit_mutex
);
3493 memswlimit
= res_counter_read_u64(&memcg
->memsw
, RES_LIMIT
);
3494 if (memswlimit
< val
) {
3496 mutex_unlock(&set_limit_mutex
);
3500 memlimit
= res_counter_read_u64(&memcg
->res
, RES_LIMIT
);
3504 ret
= res_counter_set_limit(&memcg
->res
, val
);
3506 if (memswlimit
== val
)
3507 memcg
->memsw_is_minimum
= true;
3509 memcg
->memsw_is_minimum
= false;
3511 mutex_unlock(&set_limit_mutex
);
3516 mem_cgroup_reclaim(memcg
, GFP_KERNEL
,
3517 MEM_CGROUP_RECLAIM_SHRINK
);
3518 curusage
= res_counter_read_u64(&memcg
->res
, RES_USAGE
);
3519 /* Usage is reduced ? */
3520 if (curusage
>= oldusage
)
3523 oldusage
= curusage
;
3525 if (!ret
&& enlarge
)
3526 memcg_oom_recover(memcg
);
3531 static int mem_cgroup_resize_memsw_limit(struct mem_cgroup
*memcg
,
3532 unsigned long long val
)
3535 u64 memlimit
, memswlimit
, oldusage
, curusage
;
3536 int children
= mem_cgroup_count_children(memcg
);
3540 /* see mem_cgroup_resize_res_limit */
3541 retry_count
= children
* MEM_CGROUP_RECLAIM_RETRIES
;
3542 oldusage
= res_counter_read_u64(&memcg
->memsw
, RES_USAGE
);
3543 while (retry_count
) {
3544 if (signal_pending(current
)) {
3549 * Rather than hide all in some function, I do this in
3550 * open coded manner. You see what this really does.
3551 * We have to guarantee memcg->res.limit <= memcg->memsw.limit.
3553 mutex_lock(&set_limit_mutex
);
3554 memlimit
= res_counter_read_u64(&memcg
->res
, RES_LIMIT
);
3555 if (memlimit
> val
) {
3557 mutex_unlock(&set_limit_mutex
);
3560 memswlimit
= res_counter_read_u64(&memcg
->memsw
, RES_LIMIT
);
3561 if (memswlimit
< val
)
3563 ret
= res_counter_set_limit(&memcg
->memsw
, val
);
3565 if (memlimit
== val
)
3566 memcg
->memsw_is_minimum
= true;
3568 memcg
->memsw_is_minimum
= false;
3570 mutex_unlock(&set_limit_mutex
);
3575 mem_cgroup_reclaim(memcg
, GFP_KERNEL
,
3576 MEM_CGROUP_RECLAIM_NOSWAP
|
3577 MEM_CGROUP_RECLAIM_SHRINK
);
3578 curusage
= res_counter_read_u64(&memcg
->memsw
, RES_USAGE
);
3579 /* Usage is reduced ? */
3580 if (curusage
>= oldusage
)
3583 oldusage
= curusage
;
3585 if (!ret
&& enlarge
)
3586 memcg_oom_recover(memcg
);
3590 unsigned long mem_cgroup_soft_limit_reclaim(struct zone
*zone
, int order
,
3592 unsigned long *total_scanned
)
3594 unsigned long nr_reclaimed
= 0;
3595 struct mem_cgroup_per_zone
*mz
, *next_mz
= NULL
;
3596 unsigned long reclaimed
;
3598 struct mem_cgroup_tree_per_zone
*mctz
;
3599 unsigned long long excess
;
3600 unsigned long nr_scanned
;
3605 mctz
= soft_limit_tree_node_zone(zone_to_nid(zone
), zone_idx(zone
));
3607 * This loop can run a while, specially if mem_cgroup's continuously
3608 * keep exceeding their soft limit and putting the system under
3615 mz
= mem_cgroup_largest_soft_limit_node(mctz
);
3620 reclaimed
= mem_cgroup_soft_reclaim(mz
->memcg
, zone
,
3621 gfp_mask
, &nr_scanned
);
3622 nr_reclaimed
+= reclaimed
;
3623 *total_scanned
+= nr_scanned
;
3624 spin_lock(&mctz
->lock
);
3627 * If we failed to reclaim anything from this memory cgroup
3628 * it is time to move on to the next cgroup
3634 * Loop until we find yet another one.
3636 * By the time we get the soft_limit lock
3637 * again, someone might have aded the
3638 * group back on the RB tree. Iterate to
3639 * make sure we get a different mem.
3640 * mem_cgroup_largest_soft_limit_node returns
3641 * NULL if no other cgroup is present on
3645 __mem_cgroup_largest_soft_limit_node(mctz
);
3647 css_put(&next_mz
->memcg
->css
);
3648 else /* next_mz == NULL or other memcg */
3652 __mem_cgroup_remove_exceeded(mz
->memcg
, mz
, mctz
);
3653 excess
= res_counter_soft_limit_excess(&mz
->memcg
->res
);
3655 * One school of thought says that we should not add
3656 * back the node to the tree if reclaim returns 0.
3657 * But our reclaim could return 0, simply because due
3658 * to priority we are exposing a smaller subset of
3659 * memory to reclaim from. Consider this as a longer
3662 /* If excess == 0, no tree ops */
3663 __mem_cgroup_insert_exceeded(mz
->memcg
, mz
, mctz
, excess
);
3664 spin_unlock(&mctz
->lock
);
3665 css_put(&mz
->memcg
->css
);
3668 * Could not reclaim anything and there are no more
3669 * mem cgroups to try or we seem to be looping without
3670 * reclaiming anything.
3672 if (!nr_reclaimed
&&
3674 loop
> MEM_CGROUP_MAX_SOFT_LIMIT_RECLAIM_LOOPS
))
3676 } while (!nr_reclaimed
);
3678 css_put(&next_mz
->memcg
->css
);
3679 return nr_reclaimed
;
3683 * mem_cgroup_force_empty_list - clears LRU of a group
3684 * @memcg: group to clear
3687 * @lru: lru to to clear
3689 * Traverse a specified page_cgroup list and try to drop them all. This doesn't
3690 * reclaim the pages page themselves - pages are moved to the parent (or root)
3693 static void mem_cgroup_force_empty_list(struct mem_cgroup
*memcg
,
3694 int node
, int zid
, enum lru_list lru
)
3696 struct mem_cgroup_per_zone
*mz
;
3697 unsigned long flags
;
3698 struct list_head
*list
;
3702 zone
= &NODE_DATA(node
)->node_zones
[zid
];
3703 mz
= mem_cgroup_zoneinfo(memcg
, node
, zid
);
3704 list
= &mz
->lruvec
.lists
[lru
];
3708 struct page_cgroup
*pc
;
3711 spin_lock_irqsave(&zone
->lru_lock
, flags
);
3712 if (list_empty(list
)) {
3713 spin_unlock_irqrestore(&zone
->lru_lock
, flags
);
3716 page
= list_entry(list
->prev
, struct page
, lru
);
3718 list_move(&page
->lru
, list
);
3720 spin_unlock_irqrestore(&zone
->lru_lock
, flags
);
3723 spin_unlock_irqrestore(&zone
->lru_lock
, flags
);
3725 pc
= lookup_page_cgroup(page
);
3727 if (mem_cgroup_move_parent(page
, pc
, memcg
)) {
3728 /* found lock contention or "pc" is obsolete. */
3733 } while (!list_empty(list
));
3737 * make mem_cgroup's charge to be 0 if there is no task by moving
3738 * all the charges and pages to the parent.
3739 * This enables deleting this mem_cgroup.
3741 * Caller is responsible for holding css reference on the memcg.
3743 static void mem_cgroup_reparent_charges(struct mem_cgroup
*memcg
)
3748 /* This is for making all *used* pages to be on LRU. */
3749 lru_add_drain_all();
3750 drain_all_stock_sync(memcg
);
3751 mem_cgroup_start_move(memcg
);
3752 for_each_node_state(node
, N_HIGH_MEMORY
) {
3753 for (zid
= 0; zid
< MAX_NR_ZONES
; zid
++) {
3756 mem_cgroup_force_empty_list(memcg
,
3761 mem_cgroup_end_move(memcg
);
3762 memcg_oom_recover(memcg
);
3766 * This is a safety check because mem_cgroup_force_empty_list
3767 * could have raced with mem_cgroup_replace_page_cache callers
3768 * so the lru seemed empty but the page could have been added
3769 * right after the check. RES_USAGE should be safe as we always
3770 * charge before adding to the LRU.
3772 } while (res_counter_read_u64(&memcg
->res
, RES_USAGE
) > 0);
3776 * Reclaims as many pages from the given memcg as possible and moves
3777 * the rest to the parent.
3779 * Caller is responsible for holding css reference for memcg.
3781 static int mem_cgroup_force_empty(struct mem_cgroup
*memcg
)
3783 int nr_retries
= MEM_CGROUP_RECLAIM_RETRIES
;
3784 struct cgroup
*cgrp
= memcg
->css
.cgroup
;
3786 /* returns EBUSY if there is a task or if we come here twice. */
3787 if (cgroup_task_count(cgrp
) || !list_empty(&cgrp
->children
))
3790 /* we call try-to-free pages for make this cgroup empty */
3791 lru_add_drain_all();
3792 /* try to free all pages in this cgroup */
3793 while (nr_retries
&& res_counter_read_u64(&memcg
->res
, RES_USAGE
) > 0) {
3796 if (signal_pending(current
))
3799 progress
= try_to_free_mem_cgroup_pages(memcg
, GFP_KERNEL
,
3803 /* maybe some writeback is necessary */
3804 congestion_wait(BLK_RW_ASYNC
, HZ
/10);
3809 mem_cgroup_reparent_charges(memcg
);
3814 static int mem_cgroup_force_empty_write(struct cgroup
*cont
, unsigned int event
)
3816 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cont
);
3819 if (mem_cgroup_is_root(memcg
))
3821 css_get(&memcg
->css
);
3822 ret
= mem_cgroup_force_empty(memcg
);
3823 css_put(&memcg
->css
);
3829 static u64
mem_cgroup_hierarchy_read(struct cgroup
*cont
, struct cftype
*cft
)
3831 return mem_cgroup_from_cont(cont
)->use_hierarchy
;
3834 static int mem_cgroup_hierarchy_write(struct cgroup
*cont
, struct cftype
*cft
,
3838 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cont
);
3839 struct cgroup
*parent
= cont
->parent
;
3840 struct mem_cgroup
*parent_memcg
= NULL
;
3843 parent_memcg
= mem_cgroup_from_cont(parent
);
3847 if (memcg
->use_hierarchy
== val
)
3851 * If parent's use_hierarchy is set, we can't make any modifications
3852 * in the child subtrees. If it is unset, then the change can
3853 * occur, provided the current cgroup has no children.
3855 * For the root cgroup, parent_mem is NULL, we allow value to be
3856 * set if there are no children.
3858 if ((!parent_memcg
|| !parent_memcg
->use_hierarchy
) &&
3859 (val
== 1 || val
== 0)) {
3860 if (list_empty(&cont
->children
))
3861 memcg
->use_hierarchy
= val
;
3874 static unsigned long mem_cgroup_recursive_stat(struct mem_cgroup
*memcg
,
3875 enum mem_cgroup_stat_index idx
)
3877 struct mem_cgroup
*iter
;
3880 /* Per-cpu values can be negative, use a signed accumulator */
3881 for_each_mem_cgroup_tree(iter
, memcg
)
3882 val
+= mem_cgroup_read_stat(iter
, idx
);
3884 if (val
< 0) /* race ? */
3889 static inline u64
mem_cgroup_usage(struct mem_cgroup
*memcg
, bool swap
)
3893 if (!mem_cgroup_is_root(memcg
)) {
3895 return res_counter_read_u64(&memcg
->res
, RES_USAGE
);
3897 return res_counter_read_u64(&memcg
->memsw
, RES_USAGE
);
3900 val
= mem_cgroup_recursive_stat(memcg
, MEM_CGROUP_STAT_CACHE
);
3901 val
+= mem_cgroup_recursive_stat(memcg
, MEM_CGROUP_STAT_RSS
);
3904 val
+= mem_cgroup_recursive_stat(memcg
, MEM_CGROUP_STAT_SWAP
);
3906 return val
<< PAGE_SHIFT
;
3909 static ssize_t
mem_cgroup_read(struct cgroup
*cont
, struct cftype
*cft
,
3910 struct file
*file
, char __user
*buf
,
3911 size_t nbytes
, loff_t
*ppos
)
3913 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cont
);
3916 int type
, name
, len
;
3918 type
= MEMFILE_TYPE(cft
->private);
3919 name
= MEMFILE_ATTR(cft
->private);
3921 if (!do_swap_account
&& type
== _MEMSWAP
)
3926 if (name
== RES_USAGE
)
3927 val
= mem_cgroup_usage(memcg
, false);
3929 val
= res_counter_read_u64(&memcg
->res
, name
);
3932 if (name
== RES_USAGE
)
3933 val
= mem_cgroup_usage(memcg
, true);
3935 val
= res_counter_read_u64(&memcg
->memsw
, name
);
3941 len
= scnprintf(str
, sizeof(str
), "%llu\n", (unsigned long long)val
);
3942 return simple_read_from_buffer(buf
, nbytes
, ppos
, str
, len
);
3945 * The user of this function is...
3948 static int mem_cgroup_write(struct cgroup
*cont
, struct cftype
*cft
,
3951 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cont
);
3953 unsigned long long val
;
3956 type
= MEMFILE_TYPE(cft
->private);
3957 name
= MEMFILE_ATTR(cft
->private);
3959 if (!do_swap_account
&& type
== _MEMSWAP
)
3964 if (mem_cgroup_is_root(memcg
)) { /* Can't set limit on root */
3968 /* This function does all necessary parse...reuse it */
3969 ret
= res_counter_memparse_write_strategy(buffer
, &val
);
3973 ret
= mem_cgroup_resize_limit(memcg
, val
);
3975 ret
= mem_cgroup_resize_memsw_limit(memcg
, val
);
3977 case RES_SOFT_LIMIT
:
3978 ret
= res_counter_memparse_write_strategy(buffer
, &val
);
3982 * For memsw, soft limits are hard to implement in terms
3983 * of semantics, for now, we support soft limits for
3984 * control without swap
3987 ret
= res_counter_set_soft_limit(&memcg
->res
, val
);
3992 ret
= -EINVAL
; /* should be BUG() ? */
3998 static void memcg_get_hierarchical_limit(struct mem_cgroup
*memcg
,
3999 unsigned long long *mem_limit
, unsigned long long *memsw_limit
)
4001 struct cgroup
*cgroup
;
4002 unsigned long long min_limit
, min_memsw_limit
, tmp
;
4004 min_limit
= res_counter_read_u64(&memcg
->res
, RES_LIMIT
);
4005 min_memsw_limit
= res_counter_read_u64(&memcg
->memsw
, RES_LIMIT
);
4006 cgroup
= memcg
->css
.cgroup
;
4007 if (!memcg
->use_hierarchy
)
4010 while (cgroup
->parent
) {
4011 cgroup
= cgroup
->parent
;
4012 memcg
= mem_cgroup_from_cont(cgroup
);
4013 if (!memcg
->use_hierarchy
)
4015 tmp
= res_counter_read_u64(&memcg
->res
, RES_LIMIT
);
4016 min_limit
= min(min_limit
, tmp
);
4017 tmp
= res_counter_read_u64(&memcg
->memsw
, RES_LIMIT
);
4018 min_memsw_limit
= min(min_memsw_limit
, tmp
);
4021 *mem_limit
= min_limit
;
4022 *memsw_limit
= min_memsw_limit
;
4025 static int mem_cgroup_reset(struct cgroup
*cont
, unsigned int event
)
4027 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cont
);
4030 type
= MEMFILE_TYPE(event
);
4031 name
= MEMFILE_ATTR(event
);
4033 if (!do_swap_account
&& type
== _MEMSWAP
)
4039 res_counter_reset_max(&memcg
->res
);
4041 res_counter_reset_max(&memcg
->memsw
);
4045 res_counter_reset_failcnt(&memcg
->res
);
4047 res_counter_reset_failcnt(&memcg
->memsw
);
4054 static u64
mem_cgroup_move_charge_read(struct cgroup
*cgrp
,
4057 return mem_cgroup_from_cont(cgrp
)->move_charge_at_immigrate
;
4061 static int mem_cgroup_move_charge_write(struct cgroup
*cgrp
,
4062 struct cftype
*cft
, u64 val
)
4064 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cgrp
);
4066 if (val
>= (1 << NR_MOVE_TYPE
))
4069 * We check this value several times in both in can_attach() and
4070 * attach(), so we need cgroup lock to prevent this value from being
4074 memcg
->move_charge_at_immigrate
= val
;
4080 static int mem_cgroup_move_charge_write(struct cgroup
*cgrp
,
4081 struct cftype
*cft
, u64 val
)
4088 static int memcg_numa_stat_show(struct cgroup
*cont
, struct cftype
*cft
,
4092 unsigned long total_nr
, file_nr
, anon_nr
, unevictable_nr
;
4093 unsigned long node_nr
;
4094 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cont
);
4096 total_nr
= mem_cgroup_nr_lru_pages(memcg
, LRU_ALL
);
4097 seq_printf(m
, "total=%lu", total_nr
);
4098 for_each_node_state(nid
, N_HIGH_MEMORY
) {
4099 node_nr
= mem_cgroup_node_nr_lru_pages(memcg
, nid
, LRU_ALL
);
4100 seq_printf(m
, " N%d=%lu", nid
, node_nr
);
4104 file_nr
= mem_cgroup_nr_lru_pages(memcg
, LRU_ALL_FILE
);
4105 seq_printf(m
, "file=%lu", file_nr
);
4106 for_each_node_state(nid
, N_HIGH_MEMORY
) {
4107 node_nr
= mem_cgroup_node_nr_lru_pages(memcg
, nid
,
4109 seq_printf(m
, " N%d=%lu", nid
, node_nr
);
4113 anon_nr
= mem_cgroup_nr_lru_pages(memcg
, LRU_ALL_ANON
);
4114 seq_printf(m
, "anon=%lu", anon_nr
);
4115 for_each_node_state(nid
, N_HIGH_MEMORY
) {
4116 node_nr
= mem_cgroup_node_nr_lru_pages(memcg
, nid
,
4118 seq_printf(m
, " N%d=%lu", nid
, node_nr
);
4122 unevictable_nr
= mem_cgroup_nr_lru_pages(memcg
, BIT(LRU_UNEVICTABLE
));
4123 seq_printf(m
, "unevictable=%lu", unevictable_nr
);
4124 for_each_node_state(nid
, N_HIGH_MEMORY
) {
4125 node_nr
= mem_cgroup_node_nr_lru_pages(memcg
, nid
,
4126 BIT(LRU_UNEVICTABLE
));
4127 seq_printf(m
, " N%d=%lu", nid
, node_nr
);
4132 #endif /* CONFIG_NUMA */
4134 static const char * const mem_cgroup_lru_names
[] = {
4142 static inline void mem_cgroup_lru_names_not_uptodate(void)
4144 BUILD_BUG_ON(ARRAY_SIZE(mem_cgroup_lru_names
) != NR_LRU_LISTS
);
4147 static int memcg_stat_show(struct cgroup
*cont
, struct cftype
*cft
,
4150 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cont
);
4151 struct mem_cgroup
*mi
;
4154 for (i
= 0; i
< MEM_CGROUP_STAT_NSTATS
; i
++) {
4155 if (i
== MEM_CGROUP_STAT_SWAP
&& !do_swap_account
)
4157 seq_printf(m
, "%s %ld\n", mem_cgroup_stat_names
[i
],
4158 mem_cgroup_read_stat(memcg
, i
) * PAGE_SIZE
);
4161 for (i
= 0; i
< MEM_CGROUP_EVENTS_NSTATS
; i
++)
4162 seq_printf(m
, "%s %lu\n", mem_cgroup_events_names
[i
],
4163 mem_cgroup_read_events(memcg
, i
));
4165 for (i
= 0; i
< NR_LRU_LISTS
; i
++)
4166 seq_printf(m
, "%s %lu\n", mem_cgroup_lru_names
[i
],
4167 mem_cgroup_nr_lru_pages(memcg
, BIT(i
)) * PAGE_SIZE
);
4169 /* Hierarchical information */
4171 unsigned long long limit
, memsw_limit
;
4172 memcg_get_hierarchical_limit(memcg
, &limit
, &memsw_limit
);
4173 seq_printf(m
, "hierarchical_memory_limit %llu\n", limit
);
4174 if (do_swap_account
)
4175 seq_printf(m
, "hierarchical_memsw_limit %llu\n",
4179 for (i
= 0; i
< MEM_CGROUP_STAT_NSTATS
; i
++) {
4182 if (i
== MEM_CGROUP_STAT_SWAP
&& !do_swap_account
)
4184 for_each_mem_cgroup_tree(mi
, memcg
)
4185 val
+= mem_cgroup_read_stat(mi
, i
) * PAGE_SIZE
;
4186 seq_printf(m
, "total_%s %lld\n", mem_cgroup_stat_names
[i
], val
);
4189 for (i
= 0; i
< MEM_CGROUP_EVENTS_NSTATS
; i
++) {
4190 unsigned long long val
= 0;
4192 for_each_mem_cgroup_tree(mi
, memcg
)
4193 val
+= mem_cgroup_read_events(mi
, i
);
4194 seq_printf(m
, "total_%s %llu\n",
4195 mem_cgroup_events_names
[i
], val
);
4198 for (i
= 0; i
< NR_LRU_LISTS
; i
++) {
4199 unsigned long long val
= 0;
4201 for_each_mem_cgroup_tree(mi
, memcg
)
4202 val
+= mem_cgroup_nr_lru_pages(mi
, BIT(i
)) * PAGE_SIZE
;
4203 seq_printf(m
, "total_%s %llu\n", mem_cgroup_lru_names
[i
], val
);
4206 #ifdef CONFIG_DEBUG_VM
4209 struct mem_cgroup_per_zone
*mz
;
4210 struct zone_reclaim_stat
*rstat
;
4211 unsigned long recent_rotated
[2] = {0, 0};
4212 unsigned long recent_scanned
[2] = {0, 0};
4214 for_each_online_node(nid
)
4215 for (zid
= 0; zid
< MAX_NR_ZONES
; zid
++) {
4216 mz
= mem_cgroup_zoneinfo(memcg
, nid
, zid
);
4217 rstat
= &mz
->lruvec
.reclaim_stat
;
4219 recent_rotated
[0] += rstat
->recent_rotated
[0];
4220 recent_rotated
[1] += rstat
->recent_rotated
[1];
4221 recent_scanned
[0] += rstat
->recent_scanned
[0];
4222 recent_scanned
[1] += rstat
->recent_scanned
[1];
4224 seq_printf(m
, "recent_rotated_anon %lu\n", recent_rotated
[0]);
4225 seq_printf(m
, "recent_rotated_file %lu\n", recent_rotated
[1]);
4226 seq_printf(m
, "recent_scanned_anon %lu\n", recent_scanned
[0]);
4227 seq_printf(m
, "recent_scanned_file %lu\n", recent_scanned
[1]);
4234 static u64
mem_cgroup_swappiness_read(struct cgroup
*cgrp
, struct cftype
*cft
)
4236 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cgrp
);
4238 return mem_cgroup_swappiness(memcg
);
4241 static int mem_cgroup_swappiness_write(struct cgroup
*cgrp
, struct cftype
*cft
,
4244 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cgrp
);
4245 struct mem_cgroup
*parent
;
4250 if (cgrp
->parent
== NULL
)
4253 parent
= mem_cgroup_from_cont(cgrp
->parent
);
4257 /* If under hierarchy, only empty-root can set this value */
4258 if ((parent
->use_hierarchy
) ||
4259 (memcg
->use_hierarchy
&& !list_empty(&cgrp
->children
))) {
4264 memcg
->swappiness
= val
;
4271 static void __mem_cgroup_threshold(struct mem_cgroup
*memcg
, bool swap
)
4273 struct mem_cgroup_threshold_ary
*t
;
4279 t
= rcu_dereference(memcg
->thresholds
.primary
);
4281 t
= rcu_dereference(memcg
->memsw_thresholds
.primary
);
4286 usage
= mem_cgroup_usage(memcg
, swap
);
4289 * current_threshold points to threshold just below or equal to usage.
4290 * If it's not true, a threshold was crossed after last
4291 * call of __mem_cgroup_threshold().
4293 i
= t
->current_threshold
;
4296 * Iterate backward over array of thresholds starting from
4297 * current_threshold and check if a threshold is crossed.
4298 * If none of thresholds below usage is crossed, we read
4299 * only one element of the array here.
4301 for (; i
>= 0 && unlikely(t
->entries
[i
].threshold
> usage
); i
--)
4302 eventfd_signal(t
->entries
[i
].eventfd
, 1);
4304 /* i = current_threshold + 1 */
4308 * Iterate forward over array of thresholds starting from
4309 * current_threshold+1 and check if a threshold is crossed.
4310 * If none of thresholds above usage is crossed, we read
4311 * only one element of the array here.
4313 for (; i
< t
->size
&& unlikely(t
->entries
[i
].threshold
<= usage
); i
++)
4314 eventfd_signal(t
->entries
[i
].eventfd
, 1);
4316 /* Update current_threshold */
4317 t
->current_threshold
= i
- 1;
4322 static void mem_cgroup_threshold(struct mem_cgroup
*memcg
)
4325 __mem_cgroup_threshold(memcg
, false);
4326 if (do_swap_account
)
4327 __mem_cgroup_threshold(memcg
, true);
4329 memcg
= parent_mem_cgroup(memcg
);
4333 static int compare_thresholds(const void *a
, const void *b
)
4335 const struct mem_cgroup_threshold
*_a
= a
;
4336 const struct mem_cgroup_threshold
*_b
= b
;
4338 return _a
->threshold
- _b
->threshold
;
4341 static int mem_cgroup_oom_notify_cb(struct mem_cgroup
*memcg
)
4343 struct mem_cgroup_eventfd_list
*ev
;
4345 list_for_each_entry(ev
, &memcg
->oom_notify
, list
)
4346 eventfd_signal(ev
->eventfd
, 1);
4350 static void mem_cgroup_oom_notify(struct mem_cgroup
*memcg
)
4352 struct mem_cgroup
*iter
;
4354 for_each_mem_cgroup_tree(iter
, memcg
)
4355 mem_cgroup_oom_notify_cb(iter
);
4358 static int mem_cgroup_usage_register_event(struct cgroup
*cgrp
,
4359 struct cftype
*cft
, struct eventfd_ctx
*eventfd
, const char *args
)
4361 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cgrp
);
4362 struct mem_cgroup_thresholds
*thresholds
;
4363 struct mem_cgroup_threshold_ary
*new;
4364 int type
= MEMFILE_TYPE(cft
->private);
4365 u64 threshold
, usage
;
4368 ret
= res_counter_memparse_write_strategy(args
, &threshold
);
4372 mutex_lock(&memcg
->thresholds_lock
);
4375 thresholds
= &memcg
->thresholds
;
4376 else if (type
== _MEMSWAP
)
4377 thresholds
= &memcg
->memsw_thresholds
;
4381 usage
= mem_cgroup_usage(memcg
, type
== _MEMSWAP
);
4383 /* Check if a threshold crossed before adding a new one */
4384 if (thresholds
->primary
)
4385 __mem_cgroup_threshold(memcg
, type
== _MEMSWAP
);
4387 size
= thresholds
->primary
? thresholds
->primary
->size
+ 1 : 1;
4389 /* Allocate memory for new array of thresholds */
4390 new = kmalloc(sizeof(*new) + size
* sizeof(struct mem_cgroup_threshold
),
4398 /* Copy thresholds (if any) to new array */
4399 if (thresholds
->primary
) {
4400 memcpy(new->entries
, thresholds
->primary
->entries
, (size
- 1) *
4401 sizeof(struct mem_cgroup_threshold
));
4404 /* Add new threshold */
4405 new->entries
[size
- 1].eventfd
= eventfd
;
4406 new->entries
[size
- 1].threshold
= threshold
;
4408 /* Sort thresholds. Registering of new threshold isn't time-critical */
4409 sort(new->entries
, size
, sizeof(struct mem_cgroup_threshold
),
4410 compare_thresholds
, NULL
);
4412 /* Find current threshold */
4413 new->current_threshold
= -1;
4414 for (i
= 0; i
< size
; i
++) {
4415 if (new->entries
[i
].threshold
<= usage
) {
4417 * new->current_threshold will not be used until
4418 * rcu_assign_pointer(), so it's safe to increment
4421 ++new->current_threshold
;
4426 /* Free old spare buffer and save old primary buffer as spare */
4427 kfree(thresholds
->spare
);
4428 thresholds
->spare
= thresholds
->primary
;
4430 rcu_assign_pointer(thresholds
->primary
, new);
4432 /* To be sure that nobody uses thresholds */
4436 mutex_unlock(&memcg
->thresholds_lock
);
4441 static void mem_cgroup_usage_unregister_event(struct cgroup
*cgrp
,
4442 struct cftype
*cft
, struct eventfd_ctx
*eventfd
)
4444 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cgrp
);
4445 struct mem_cgroup_thresholds
*thresholds
;
4446 struct mem_cgroup_threshold_ary
*new;
4447 int type
= MEMFILE_TYPE(cft
->private);
4451 mutex_lock(&memcg
->thresholds_lock
);
4453 thresholds
= &memcg
->thresholds
;
4454 else if (type
== _MEMSWAP
)
4455 thresholds
= &memcg
->memsw_thresholds
;
4459 if (!thresholds
->primary
)
4462 usage
= mem_cgroup_usage(memcg
, type
== _MEMSWAP
);
4464 /* Check if a threshold crossed before removing */
4465 __mem_cgroup_threshold(memcg
, type
== _MEMSWAP
);
4467 /* Calculate new number of threshold */
4469 for (i
= 0; i
< thresholds
->primary
->size
; i
++) {
4470 if (thresholds
->primary
->entries
[i
].eventfd
!= eventfd
)
4474 new = thresholds
->spare
;
4476 /* Set thresholds array to NULL if we don't have thresholds */
4485 /* Copy thresholds and find current threshold */
4486 new->current_threshold
= -1;
4487 for (i
= 0, j
= 0; i
< thresholds
->primary
->size
; i
++) {
4488 if (thresholds
->primary
->entries
[i
].eventfd
== eventfd
)
4491 new->entries
[j
] = thresholds
->primary
->entries
[i
];
4492 if (new->entries
[j
].threshold
<= usage
) {
4494 * new->current_threshold will not be used
4495 * until rcu_assign_pointer(), so it's safe to increment
4498 ++new->current_threshold
;
4504 /* Swap primary and spare array */
4505 thresholds
->spare
= thresholds
->primary
;
4506 /* If all events are unregistered, free the spare array */
4508 kfree(thresholds
->spare
);
4509 thresholds
->spare
= NULL
;
4512 rcu_assign_pointer(thresholds
->primary
, new);
4514 /* To be sure that nobody uses thresholds */
4517 mutex_unlock(&memcg
->thresholds_lock
);
4520 static int mem_cgroup_oom_register_event(struct cgroup
*cgrp
,
4521 struct cftype
*cft
, struct eventfd_ctx
*eventfd
, const char *args
)
4523 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cgrp
);
4524 struct mem_cgroup_eventfd_list
*event
;
4525 int type
= MEMFILE_TYPE(cft
->private);
4527 BUG_ON(type
!= _OOM_TYPE
);
4528 event
= kmalloc(sizeof(*event
), GFP_KERNEL
);
4532 spin_lock(&memcg_oom_lock
);
4534 event
->eventfd
= eventfd
;
4535 list_add(&event
->list
, &memcg
->oom_notify
);
4537 /* already in OOM ? */
4538 if (atomic_read(&memcg
->under_oom
))
4539 eventfd_signal(eventfd
, 1);
4540 spin_unlock(&memcg_oom_lock
);
4545 static void mem_cgroup_oom_unregister_event(struct cgroup
*cgrp
,
4546 struct cftype
*cft
, struct eventfd_ctx
*eventfd
)
4548 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cgrp
);
4549 struct mem_cgroup_eventfd_list
*ev
, *tmp
;
4550 int type
= MEMFILE_TYPE(cft
->private);
4552 BUG_ON(type
!= _OOM_TYPE
);
4554 spin_lock(&memcg_oom_lock
);
4556 list_for_each_entry_safe(ev
, tmp
, &memcg
->oom_notify
, list
) {
4557 if (ev
->eventfd
== eventfd
) {
4558 list_del(&ev
->list
);
4563 spin_unlock(&memcg_oom_lock
);
4566 static int mem_cgroup_oom_control_read(struct cgroup
*cgrp
,
4567 struct cftype
*cft
, struct cgroup_map_cb
*cb
)
4569 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cgrp
);
4571 cb
->fill(cb
, "oom_kill_disable", memcg
->oom_kill_disable
);
4573 if (atomic_read(&memcg
->under_oom
))
4574 cb
->fill(cb
, "under_oom", 1);
4576 cb
->fill(cb
, "under_oom", 0);
4580 static int mem_cgroup_oom_control_write(struct cgroup
*cgrp
,
4581 struct cftype
*cft
, u64 val
)
4583 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cgrp
);
4584 struct mem_cgroup
*parent
;
4586 /* cannot set to root cgroup and only 0 and 1 are allowed */
4587 if (!cgrp
->parent
|| !((val
== 0) || (val
== 1)))
4590 parent
= mem_cgroup_from_cont(cgrp
->parent
);
4593 /* oom-kill-disable is a flag for subhierarchy. */
4594 if ((parent
->use_hierarchy
) ||
4595 (memcg
->use_hierarchy
&& !list_empty(&cgrp
->children
))) {
4599 memcg
->oom_kill_disable
= val
;
4601 memcg_oom_recover(memcg
);
4606 #ifdef CONFIG_MEMCG_KMEM
4607 static int memcg_init_kmem(struct mem_cgroup
*memcg
, struct cgroup_subsys
*ss
)
4609 return mem_cgroup_sockets_init(memcg
, ss
);
4612 static void kmem_cgroup_destroy(struct mem_cgroup
*memcg
)
4614 mem_cgroup_sockets_destroy(memcg
);
4617 static int memcg_init_kmem(struct mem_cgroup
*memcg
, struct cgroup_subsys
*ss
)
4622 static void kmem_cgroup_destroy(struct mem_cgroup
*memcg
)
4627 static struct cftype mem_cgroup_files
[] = {
4629 .name
= "usage_in_bytes",
4630 .private = MEMFILE_PRIVATE(_MEM
, RES_USAGE
),
4631 .read
= mem_cgroup_read
,
4632 .register_event
= mem_cgroup_usage_register_event
,
4633 .unregister_event
= mem_cgroup_usage_unregister_event
,
4636 .name
= "max_usage_in_bytes",
4637 .private = MEMFILE_PRIVATE(_MEM
, RES_MAX_USAGE
),
4638 .trigger
= mem_cgroup_reset
,
4639 .read
= mem_cgroup_read
,
4642 .name
= "limit_in_bytes",
4643 .private = MEMFILE_PRIVATE(_MEM
, RES_LIMIT
),
4644 .write_string
= mem_cgroup_write
,
4645 .read
= mem_cgroup_read
,
4648 .name
= "soft_limit_in_bytes",
4649 .private = MEMFILE_PRIVATE(_MEM
, RES_SOFT_LIMIT
),
4650 .write_string
= mem_cgroup_write
,
4651 .read
= mem_cgroup_read
,
4655 .private = MEMFILE_PRIVATE(_MEM
, RES_FAILCNT
),
4656 .trigger
= mem_cgroup_reset
,
4657 .read
= mem_cgroup_read
,
4661 .read_seq_string
= memcg_stat_show
,
4664 .name
= "force_empty",
4665 .trigger
= mem_cgroup_force_empty_write
,
4668 .name
= "use_hierarchy",
4669 .write_u64
= mem_cgroup_hierarchy_write
,
4670 .read_u64
= mem_cgroup_hierarchy_read
,
4673 .name
= "swappiness",
4674 .read_u64
= mem_cgroup_swappiness_read
,
4675 .write_u64
= mem_cgroup_swappiness_write
,
4678 .name
= "move_charge_at_immigrate",
4679 .read_u64
= mem_cgroup_move_charge_read
,
4680 .write_u64
= mem_cgroup_move_charge_write
,
4683 .name
= "oom_control",
4684 .read_map
= mem_cgroup_oom_control_read
,
4685 .write_u64
= mem_cgroup_oom_control_write
,
4686 .register_event
= mem_cgroup_oom_register_event
,
4687 .unregister_event
= mem_cgroup_oom_unregister_event
,
4688 .private = MEMFILE_PRIVATE(_OOM_TYPE
, OOM_CONTROL
),
4692 .name
= "numa_stat",
4693 .read_seq_string
= memcg_numa_stat_show
,
4696 #ifdef CONFIG_MEMCG_SWAP
4698 .name
= "memsw.usage_in_bytes",
4699 .private = MEMFILE_PRIVATE(_MEMSWAP
, RES_USAGE
),
4700 .read
= mem_cgroup_read
,
4701 .register_event
= mem_cgroup_usage_register_event
,
4702 .unregister_event
= mem_cgroup_usage_unregister_event
,
4705 .name
= "memsw.max_usage_in_bytes",
4706 .private = MEMFILE_PRIVATE(_MEMSWAP
, RES_MAX_USAGE
),
4707 .trigger
= mem_cgroup_reset
,
4708 .read
= mem_cgroup_read
,
4711 .name
= "memsw.limit_in_bytes",
4712 .private = MEMFILE_PRIVATE(_MEMSWAP
, RES_LIMIT
),
4713 .write_string
= mem_cgroup_write
,
4714 .read
= mem_cgroup_read
,
4717 .name
= "memsw.failcnt",
4718 .private = MEMFILE_PRIVATE(_MEMSWAP
, RES_FAILCNT
),
4719 .trigger
= mem_cgroup_reset
,
4720 .read
= mem_cgroup_read
,
4723 { }, /* terminate */
4726 static int alloc_mem_cgroup_per_zone_info(struct mem_cgroup
*memcg
, int node
)
4728 struct mem_cgroup_per_node
*pn
;
4729 struct mem_cgroup_per_zone
*mz
;
4730 int zone
, tmp
= node
;
4732 * This routine is called against possible nodes.
4733 * But it's BUG to call kmalloc() against offline node.
4735 * TODO: this routine can waste much memory for nodes which will
4736 * never be onlined. It's better to use memory hotplug callback
4739 if (!node_state(node
, N_NORMAL_MEMORY
))
4741 pn
= kzalloc_node(sizeof(*pn
), GFP_KERNEL
, tmp
);
4745 for (zone
= 0; zone
< MAX_NR_ZONES
; zone
++) {
4746 mz
= &pn
->zoneinfo
[zone
];
4747 lruvec_init(&mz
->lruvec
, &NODE_DATA(node
)->node_zones
[zone
]);
4748 mz
->usage_in_excess
= 0;
4749 mz
->on_tree
= false;
4752 memcg
->info
.nodeinfo
[node
] = pn
;
4756 static void free_mem_cgroup_per_zone_info(struct mem_cgroup
*memcg
, int node
)
4758 kfree(memcg
->info
.nodeinfo
[node
]);
4761 static struct mem_cgroup
*mem_cgroup_alloc(void)
4763 struct mem_cgroup
*memcg
;
4764 int size
= sizeof(struct mem_cgroup
);
4766 /* Can be very big if MAX_NUMNODES is very big */
4767 if (size
< PAGE_SIZE
)
4768 memcg
= kzalloc(size
, GFP_KERNEL
);
4770 memcg
= vzalloc(size
);
4775 memcg
->stat
= alloc_percpu(struct mem_cgroup_stat_cpu
);
4778 spin_lock_init(&memcg
->pcp_counter_lock
);
4782 if (size
< PAGE_SIZE
)
4790 * Helpers for freeing a kmalloc()ed/vzalloc()ed mem_cgroup by RCU,
4791 * but in process context. The work_freeing structure is overlaid
4792 * on the rcu_freeing structure, which itself is overlaid on memsw.
4794 static void free_work(struct work_struct
*work
)
4796 struct mem_cgroup
*memcg
;
4797 int size
= sizeof(struct mem_cgroup
);
4799 memcg
= container_of(work
, struct mem_cgroup
, work_freeing
);
4801 * We need to make sure that (at least for now), the jump label
4802 * destruction code runs outside of the cgroup lock. This is because
4803 * get_online_cpus(), which is called from the static_branch update,
4804 * can't be called inside the cgroup_lock. cpusets are the ones
4805 * enforcing this dependency, so if they ever change, we might as well.
4807 * schedule_work() will guarantee this happens. Be careful if you need
4808 * to move this code around, and make sure it is outside
4811 disarm_sock_keys(memcg
);
4812 if (size
< PAGE_SIZE
)
4818 static void free_rcu(struct rcu_head
*rcu_head
)
4820 struct mem_cgroup
*memcg
;
4822 memcg
= container_of(rcu_head
, struct mem_cgroup
, rcu_freeing
);
4823 INIT_WORK(&memcg
->work_freeing
, free_work
);
4824 schedule_work(&memcg
->work_freeing
);
4828 * At destroying mem_cgroup, references from swap_cgroup can remain.
4829 * (scanning all at force_empty is too costly...)
4831 * Instead of clearing all references at force_empty, we remember
4832 * the number of reference from swap_cgroup and free mem_cgroup when
4833 * it goes down to 0.
4835 * Removal of cgroup itself succeeds regardless of refs from swap.
4838 static void __mem_cgroup_free(struct mem_cgroup
*memcg
)
4842 mem_cgroup_remove_from_trees(memcg
);
4843 free_css_id(&mem_cgroup_subsys
, &memcg
->css
);
4846 free_mem_cgroup_per_zone_info(memcg
, node
);
4848 free_percpu(memcg
->stat
);
4849 call_rcu(&memcg
->rcu_freeing
, free_rcu
);
4852 static void mem_cgroup_get(struct mem_cgroup
*memcg
)
4854 atomic_inc(&memcg
->refcnt
);
4857 static void __mem_cgroup_put(struct mem_cgroup
*memcg
, int count
)
4859 if (atomic_sub_and_test(count
, &memcg
->refcnt
)) {
4860 struct mem_cgroup
*parent
= parent_mem_cgroup(memcg
);
4861 __mem_cgroup_free(memcg
);
4863 mem_cgroup_put(parent
);
4867 static void mem_cgroup_put(struct mem_cgroup
*memcg
)
4869 __mem_cgroup_put(memcg
, 1);
4873 * Returns the parent mem_cgroup in memcgroup hierarchy with hierarchy enabled.
4875 struct mem_cgroup
*parent_mem_cgroup(struct mem_cgroup
*memcg
)
4877 if (!memcg
->res
.parent
)
4879 return mem_cgroup_from_res_counter(memcg
->res
.parent
, res
);
4881 EXPORT_SYMBOL(parent_mem_cgroup
);
4883 #ifdef CONFIG_MEMCG_SWAP
4884 static void __init
enable_swap_cgroup(void)
4886 if (!mem_cgroup_disabled() && really_do_swap_account
)
4887 do_swap_account
= 1;
4890 static void __init
enable_swap_cgroup(void)
4895 static int mem_cgroup_soft_limit_tree_init(void)
4897 struct mem_cgroup_tree_per_node
*rtpn
;
4898 struct mem_cgroup_tree_per_zone
*rtpz
;
4899 int tmp
, node
, zone
;
4901 for_each_node(node
) {
4903 if (!node_state(node
, N_NORMAL_MEMORY
))
4905 rtpn
= kzalloc_node(sizeof(*rtpn
), GFP_KERNEL
, tmp
);
4909 soft_limit_tree
.rb_tree_per_node
[node
] = rtpn
;
4911 for (zone
= 0; zone
< MAX_NR_ZONES
; zone
++) {
4912 rtpz
= &rtpn
->rb_tree_per_zone
[zone
];
4913 rtpz
->rb_root
= RB_ROOT
;
4914 spin_lock_init(&rtpz
->lock
);
4920 for_each_node(node
) {
4921 if (!soft_limit_tree
.rb_tree_per_node
[node
])
4923 kfree(soft_limit_tree
.rb_tree_per_node
[node
]);
4924 soft_limit_tree
.rb_tree_per_node
[node
] = NULL
;
4930 static struct cgroup_subsys_state
* __ref
4931 mem_cgroup_create(struct cgroup
*cont
)
4933 struct mem_cgroup
*memcg
, *parent
;
4934 long error
= -ENOMEM
;
4937 memcg
= mem_cgroup_alloc();
4939 return ERR_PTR(error
);
4942 if (alloc_mem_cgroup_per_zone_info(memcg
, node
))
4946 if (cont
->parent
== NULL
) {
4948 enable_swap_cgroup();
4950 if (mem_cgroup_soft_limit_tree_init())
4952 root_mem_cgroup
= memcg
;
4953 for_each_possible_cpu(cpu
) {
4954 struct memcg_stock_pcp
*stock
=
4955 &per_cpu(memcg_stock
, cpu
);
4956 INIT_WORK(&stock
->work
, drain_local_stock
);
4958 hotcpu_notifier(memcg_cpu_hotplug_callback
, 0);
4960 parent
= mem_cgroup_from_cont(cont
->parent
);
4961 memcg
->use_hierarchy
= parent
->use_hierarchy
;
4962 memcg
->oom_kill_disable
= parent
->oom_kill_disable
;
4965 if (parent
&& parent
->use_hierarchy
) {
4966 res_counter_init(&memcg
->res
, &parent
->res
);
4967 res_counter_init(&memcg
->memsw
, &parent
->memsw
);
4969 * We increment refcnt of the parent to ensure that we can
4970 * safely access it on res_counter_charge/uncharge.
4971 * This refcnt will be decremented when freeing this
4972 * mem_cgroup(see mem_cgroup_put).
4974 mem_cgroup_get(parent
);
4976 res_counter_init(&memcg
->res
, NULL
);
4977 res_counter_init(&memcg
->memsw
, NULL
);
4979 memcg
->last_scanned_node
= MAX_NUMNODES
;
4980 INIT_LIST_HEAD(&memcg
->oom_notify
);
4983 memcg
->swappiness
= mem_cgroup_swappiness(parent
);
4984 atomic_set(&memcg
->refcnt
, 1);
4985 memcg
->move_charge_at_immigrate
= 0;
4986 mutex_init(&memcg
->thresholds_lock
);
4987 spin_lock_init(&memcg
->move_lock
);
4989 error
= memcg_init_kmem(memcg
, &mem_cgroup_subsys
);
4992 * We call put now because our (and parent's) refcnts
4993 * are already in place. mem_cgroup_put() will internally
4994 * call __mem_cgroup_free, so return directly
4996 mem_cgroup_put(memcg
);
4997 return ERR_PTR(error
);
5001 __mem_cgroup_free(memcg
);
5002 return ERR_PTR(error
);
5005 static int mem_cgroup_pre_destroy(struct cgroup
*cont
)
5007 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cont
);
5009 mem_cgroup_reparent_charges(memcg
);
5013 static void mem_cgroup_destroy(struct cgroup
*cont
)
5015 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cont
);
5017 kmem_cgroup_destroy(memcg
);
5019 mem_cgroup_put(memcg
);
5023 /* Handlers for move charge at task migration. */
5024 #define PRECHARGE_COUNT_AT_ONCE 256
5025 static int mem_cgroup_do_precharge(unsigned long count
)
5028 int batch_count
= PRECHARGE_COUNT_AT_ONCE
;
5029 struct mem_cgroup
*memcg
= mc
.to
;
5031 if (mem_cgroup_is_root(memcg
)) {
5032 mc
.precharge
+= count
;
5033 /* we don't need css_get for root */
5036 /* try to charge at once */
5038 struct res_counter
*dummy
;
5040 * "memcg" cannot be under rmdir() because we've already checked
5041 * by cgroup_lock_live_cgroup() that it is not removed and we
5042 * are still under the same cgroup_mutex. So we can postpone
5045 if (res_counter_charge(&memcg
->res
, PAGE_SIZE
* count
, &dummy
))
5047 if (do_swap_account
&& res_counter_charge(&memcg
->memsw
,
5048 PAGE_SIZE
* count
, &dummy
)) {
5049 res_counter_uncharge(&memcg
->res
, PAGE_SIZE
* count
);
5052 mc
.precharge
+= count
;
5056 /* fall back to one by one charge */
5058 if (signal_pending(current
)) {
5062 if (!batch_count
--) {
5063 batch_count
= PRECHARGE_COUNT_AT_ONCE
;
5066 ret
= __mem_cgroup_try_charge(NULL
,
5067 GFP_KERNEL
, 1, &memcg
, false);
5069 /* mem_cgroup_clear_mc() will do uncharge later */
5077 * get_mctgt_type - get target type of moving charge
5078 * @vma: the vma the pte to be checked belongs
5079 * @addr: the address corresponding to the pte to be checked
5080 * @ptent: the pte to be checked
5081 * @target: the pointer the target page or swap ent will be stored(can be NULL)
5084 * 0(MC_TARGET_NONE): if the pte is not a target for move charge.
5085 * 1(MC_TARGET_PAGE): if the page corresponding to this pte is a target for
5086 * move charge. if @target is not NULL, the page is stored in target->page
5087 * with extra refcnt got(Callers should handle it).
5088 * 2(MC_TARGET_SWAP): if the swap entry corresponding to this pte is a
5089 * target for charge migration. if @target is not NULL, the entry is stored
5092 * Called with pte lock held.
5099 enum mc_target_type
{
5105 static struct page
*mc_handle_present_pte(struct vm_area_struct
*vma
,
5106 unsigned long addr
, pte_t ptent
)
5108 struct page
*page
= vm_normal_page(vma
, addr
, ptent
);
5110 if (!page
|| !page_mapped(page
))
5112 if (PageAnon(page
)) {
5113 /* we don't move shared anon */
5116 } else if (!move_file())
5117 /* we ignore mapcount for file pages */
5119 if (!get_page_unless_zero(page
))
5126 static struct page
*mc_handle_swap_pte(struct vm_area_struct
*vma
,
5127 unsigned long addr
, pte_t ptent
, swp_entry_t
*entry
)
5129 struct page
*page
= NULL
;
5130 swp_entry_t ent
= pte_to_swp_entry(ptent
);
5132 if (!move_anon() || non_swap_entry(ent
))
5135 * Because lookup_swap_cache() updates some statistics counter,
5136 * we call find_get_page() with swapper_space directly.
5138 page
= find_get_page(&swapper_space
, ent
.val
);
5139 if (do_swap_account
)
5140 entry
->val
= ent
.val
;
5145 static struct page
*mc_handle_swap_pte(struct vm_area_struct
*vma
,
5146 unsigned long addr
, pte_t ptent
, swp_entry_t
*entry
)
5152 static struct page
*mc_handle_file_pte(struct vm_area_struct
*vma
,
5153 unsigned long addr
, pte_t ptent
, swp_entry_t
*entry
)
5155 struct page
*page
= NULL
;
5156 struct address_space
*mapping
;
5159 if (!vma
->vm_file
) /* anonymous vma */
5164 mapping
= vma
->vm_file
->f_mapping
;
5165 if (pte_none(ptent
))
5166 pgoff
= linear_page_index(vma
, addr
);
5167 else /* pte_file(ptent) is true */
5168 pgoff
= pte_to_pgoff(ptent
);
5170 /* page is moved even if it's not RSS of this task(page-faulted). */
5171 page
= find_get_page(mapping
, pgoff
);
5174 /* shmem/tmpfs may report page out on swap: account for that too. */
5175 if (radix_tree_exceptional_entry(page
)) {
5176 swp_entry_t swap
= radix_to_swp_entry(page
);
5177 if (do_swap_account
)
5179 page
= find_get_page(&swapper_space
, swap
.val
);
5185 static enum mc_target_type
get_mctgt_type(struct vm_area_struct
*vma
,
5186 unsigned long addr
, pte_t ptent
, union mc_target
*target
)
5188 struct page
*page
= NULL
;
5189 struct page_cgroup
*pc
;
5190 enum mc_target_type ret
= MC_TARGET_NONE
;
5191 swp_entry_t ent
= { .val
= 0 };
5193 if (pte_present(ptent
))
5194 page
= mc_handle_present_pte(vma
, addr
, ptent
);
5195 else if (is_swap_pte(ptent
))
5196 page
= mc_handle_swap_pte(vma
, addr
, ptent
, &ent
);
5197 else if (pte_none(ptent
) || pte_file(ptent
))
5198 page
= mc_handle_file_pte(vma
, addr
, ptent
, &ent
);
5200 if (!page
&& !ent
.val
)
5203 pc
= lookup_page_cgroup(page
);
5205 * Do only loose check w/o page_cgroup lock.
5206 * mem_cgroup_move_account() checks the pc is valid or not under
5209 if (PageCgroupUsed(pc
) && pc
->mem_cgroup
== mc
.from
) {
5210 ret
= MC_TARGET_PAGE
;
5212 target
->page
= page
;
5214 if (!ret
|| !target
)
5217 /* There is a swap entry and a page doesn't exist or isn't charged */
5218 if (ent
.val
&& !ret
&&
5219 css_id(&mc
.from
->css
) == lookup_swap_cgroup_id(ent
)) {
5220 ret
= MC_TARGET_SWAP
;
5227 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
5229 * We don't consider swapping or file mapped pages because THP does not
5230 * support them for now.
5231 * Caller should make sure that pmd_trans_huge(pmd) is true.
5233 static enum mc_target_type
get_mctgt_type_thp(struct vm_area_struct
*vma
,
5234 unsigned long addr
, pmd_t pmd
, union mc_target
*target
)
5236 struct page
*page
= NULL
;
5237 struct page_cgroup
*pc
;
5238 enum mc_target_type ret
= MC_TARGET_NONE
;
5240 page
= pmd_page(pmd
);
5241 VM_BUG_ON(!page
|| !PageHead(page
));
5244 pc
= lookup_page_cgroup(page
);
5245 if (PageCgroupUsed(pc
) && pc
->mem_cgroup
== mc
.from
) {
5246 ret
= MC_TARGET_PAGE
;
5249 target
->page
= page
;
5255 static inline enum mc_target_type
get_mctgt_type_thp(struct vm_area_struct
*vma
,
5256 unsigned long addr
, pmd_t pmd
, union mc_target
*target
)
5258 return MC_TARGET_NONE
;
5262 static int mem_cgroup_count_precharge_pte_range(pmd_t
*pmd
,
5263 unsigned long addr
, unsigned long end
,
5264 struct mm_walk
*walk
)
5266 struct vm_area_struct
*vma
= walk
->private;
5270 if (pmd_trans_huge_lock(pmd
, vma
) == 1) {
5271 if (get_mctgt_type_thp(vma
, addr
, *pmd
, NULL
) == MC_TARGET_PAGE
)
5272 mc
.precharge
+= HPAGE_PMD_NR
;
5273 spin_unlock(&vma
->vm_mm
->page_table_lock
);
5277 if (pmd_trans_unstable(pmd
))
5279 pte
= pte_offset_map_lock(vma
->vm_mm
, pmd
, addr
, &ptl
);
5280 for (; addr
!= end
; pte
++, addr
+= PAGE_SIZE
)
5281 if (get_mctgt_type(vma
, addr
, *pte
, NULL
))
5282 mc
.precharge
++; /* increment precharge temporarily */
5283 pte_unmap_unlock(pte
- 1, ptl
);
5289 static unsigned long mem_cgroup_count_precharge(struct mm_struct
*mm
)
5291 unsigned long precharge
;
5292 struct vm_area_struct
*vma
;
5294 down_read(&mm
->mmap_sem
);
5295 for (vma
= mm
->mmap
; vma
; vma
= vma
->vm_next
) {
5296 struct mm_walk mem_cgroup_count_precharge_walk
= {
5297 .pmd_entry
= mem_cgroup_count_precharge_pte_range
,
5301 if (is_vm_hugetlb_page(vma
))
5303 walk_page_range(vma
->vm_start
, vma
->vm_end
,
5304 &mem_cgroup_count_precharge_walk
);
5306 up_read(&mm
->mmap_sem
);
5308 precharge
= mc
.precharge
;
5314 static int mem_cgroup_precharge_mc(struct mm_struct
*mm
)
5316 unsigned long precharge
= mem_cgroup_count_precharge(mm
);
5318 VM_BUG_ON(mc
.moving_task
);
5319 mc
.moving_task
= current
;
5320 return mem_cgroup_do_precharge(precharge
);
5323 /* cancels all extra charges on mc.from and mc.to, and wakes up all waiters. */
5324 static void __mem_cgroup_clear_mc(void)
5326 struct mem_cgroup
*from
= mc
.from
;
5327 struct mem_cgroup
*to
= mc
.to
;
5329 /* we must uncharge all the leftover precharges from mc.to */
5331 __mem_cgroup_cancel_charge(mc
.to
, mc
.precharge
);
5335 * we didn't uncharge from mc.from at mem_cgroup_move_account(), so
5336 * we must uncharge here.
5338 if (mc
.moved_charge
) {
5339 __mem_cgroup_cancel_charge(mc
.from
, mc
.moved_charge
);
5340 mc
.moved_charge
= 0;
5342 /* we must fixup refcnts and charges */
5343 if (mc
.moved_swap
) {
5344 /* uncharge swap account from the old cgroup */
5345 if (!mem_cgroup_is_root(mc
.from
))
5346 res_counter_uncharge(&mc
.from
->memsw
,
5347 PAGE_SIZE
* mc
.moved_swap
);
5348 __mem_cgroup_put(mc
.from
, mc
.moved_swap
);
5350 if (!mem_cgroup_is_root(mc
.to
)) {
5352 * we charged both to->res and to->memsw, so we should
5355 res_counter_uncharge(&mc
.to
->res
,
5356 PAGE_SIZE
* mc
.moved_swap
);
5358 /* we've already done mem_cgroup_get(mc.to) */
5361 memcg_oom_recover(from
);
5362 memcg_oom_recover(to
);
5363 wake_up_all(&mc
.waitq
);
5366 static void mem_cgroup_clear_mc(void)
5368 struct mem_cgroup
*from
= mc
.from
;
5371 * we must clear moving_task before waking up waiters at the end of
5374 mc
.moving_task
= NULL
;
5375 __mem_cgroup_clear_mc();
5376 spin_lock(&mc
.lock
);
5379 spin_unlock(&mc
.lock
);
5380 mem_cgroup_end_move(from
);
5383 static int mem_cgroup_can_attach(struct cgroup
*cgroup
,
5384 struct cgroup_taskset
*tset
)
5386 struct task_struct
*p
= cgroup_taskset_first(tset
);
5388 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cgroup
);
5390 if (memcg
->move_charge_at_immigrate
) {
5391 struct mm_struct
*mm
;
5392 struct mem_cgroup
*from
= mem_cgroup_from_task(p
);
5394 VM_BUG_ON(from
== memcg
);
5396 mm
= get_task_mm(p
);
5399 /* We move charges only when we move a owner of the mm */
5400 if (mm
->owner
== p
) {
5403 VM_BUG_ON(mc
.precharge
);
5404 VM_BUG_ON(mc
.moved_charge
);
5405 VM_BUG_ON(mc
.moved_swap
);
5406 mem_cgroup_start_move(from
);
5407 spin_lock(&mc
.lock
);
5410 spin_unlock(&mc
.lock
);
5411 /* We set mc.moving_task later */
5413 ret
= mem_cgroup_precharge_mc(mm
);
5415 mem_cgroup_clear_mc();
5422 static void mem_cgroup_cancel_attach(struct cgroup
*cgroup
,
5423 struct cgroup_taskset
*tset
)
5425 mem_cgroup_clear_mc();
5428 static int mem_cgroup_move_charge_pte_range(pmd_t
*pmd
,
5429 unsigned long addr
, unsigned long end
,
5430 struct mm_walk
*walk
)
5433 struct vm_area_struct
*vma
= walk
->private;
5436 enum mc_target_type target_type
;
5437 union mc_target target
;
5439 struct page_cgroup
*pc
;
5442 * We don't take compound_lock() here but no race with splitting thp
5444 * - if pmd_trans_huge_lock() returns 1, the relevant thp is not
5445 * under splitting, which means there's no concurrent thp split,
5446 * - if another thread runs into split_huge_page() just after we
5447 * entered this if-block, the thread must wait for page table lock
5448 * to be unlocked in __split_huge_page_splitting(), where the main
5449 * part of thp split is not executed yet.
5451 if (pmd_trans_huge_lock(pmd
, vma
) == 1) {
5452 if (mc
.precharge
< HPAGE_PMD_NR
) {
5453 spin_unlock(&vma
->vm_mm
->page_table_lock
);
5456 target_type
= get_mctgt_type_thp(vma
, addr
, *pmd
, &target
);
5457 if (target_type
== MC_TARGET_PAGE
) {
5459 if (!isolate_lru_page(page
)) {
5460 pc
= lookup_page_cgroup(page
);
5461 if (!mem_cgroup_move_account(page
, HPAGE_PMD_NR
,
5462 pc
, mc
.from
, mc
.to
)) {
5463 mc
.precharge
-= HPAGE_PMD_NR
;
5464 mc
.moved_charge
+= HPAGE_PMD_NR
;
5466 putback_lru_page(page
);
5470 spin_unlock(&vma
->vm_mm
->page_table_lock
);
5474 if (pmd_trans_unstable(pmd
))
5477 pte
= pte_offset_map_lock(vma
->vm_mm
, pmd
, addr
, &ptl
);
5478 for (; addr
!= end
; addr
+= PAGE_SIZE
) {
5479 pte_t ptent
= *(pte
++);
5485 switch (get_mctgt_type(vma
, addr
, ptent
, &target
)) {
5486 case MC_TARGET_PAGE
:
5488 if (isolate_lru_page(page
))
5490 pc
= lookup_page_cgroup(page
);
5491 if (!mem_cgroup_move_account(page
, 1, pc
,
5494 /* we uncharge from mc.from later. */
5497 putback_lru_page(page
);
5498 put
: /* get_mctgt_type() gets the page */
5501 case MC_TARGET_SWAP
:
5503 if (!mem_cgroup_move_swap_account(ent
, mc
.from
, mc
.to
)) {
5505 /* we fixup refcnts and charges later. */
5513 pte_unmap_unlock(pte
- 1, ptl
);
5518 * We have consumed all precharges we got in can_attach().
5519 * We try charge one by one, but don't do any additional
5520 * charges to mc.to if we have failed in charge once in attach()
5523 ret
= mem_cgroup_do_precharge(1);
5531 static void mem_cgroup_move_charge(struct mm_struct
*mm
)
5533 struct vm_area_struct
*vma
;
5535 lru_add_drain_all();
5537 if (unlikely(!down_read_trylock(&mm
->mmap_sem
))) {
5539 * Someone who are holding the mmap_sem might be waiting in
5540 * waitq. So we cancel all extra charges, wake up all waiters,
5541 * and retry. Because we cancel precharges, we might not be able
5542 * to move enough charges, but moving charge is a best-effort
5543 * feature anyway, so it wouldn't be a big problem.
5545 __mem_cgroup_clear_mc();
5549 for (vma
= mm
->mmap
; vma
; vma
= vma
->vm_next
) {
5551 struct mm_walk mem_cgroup_move_charge_walk
= {
5552 .pmd_entry
= mem_cgroup_move_charge_pte_range
,
5556 if (is_vm_hugetlb_page(vma
))
5558 ret
= walk_page_range(vma
->vm_start
, vma
->vm_end
,
5559 &mem_cgroup_move_charge_walk
);
5562 * means we have consumed all precharges and failed in
5563 * doing additional charge. Just abandon here.
5567 up_read(&mm
->mmap_sem
);
5570 static void mem_cgroup_move_task(struct cgroup
*cont
,
5571 struct cgroup_taskset
*tset
)
5573 struct task_struct
*p
= cgroup_taskset_first(tset
);
5574 struct mm_struct
*mm
= get_task_mm(p
);
5578 mem_cgroup_move_charge(mm
);
5582 mem_cgroup_clear_mc();
5584 #else /* !CONFIG_MMU */
5585 static int mem_cgroup_can_attach(struct cgroup
*cgroup
,
5586 struct cgroup_taskset
*tset
)
5590 static void mem_cgroup_cancel_attach(struct cgroup
*cgroup
,
5591 struct cgroup_taskset
*tset
)
5594 static void mem_cgroup_move_task(struct cgroup
*cont
,
5595 struct cgroup_taskset
*tset
)
5600 struct cgroup_subsys mem_cgroup_subsys
= {
5602 .subsys_id
= mem_cgroup_subsys_id
,
5603 .create
= mem_cgroup_create
,
5604 .pre_destroy
= mem_cgroup_pre_destroy
,
5605 .destroy
= mem_cgroup_destroy
,
5606 .can_attach
= mem_cgroup_can_attach
,
5607 .cancel_attach
= mem_cgroup_cancel_attach
,
5608 .attach
= mem_cgroup_move_task
,
5609 .base_cftypes
= mem_cgroup_files
,
5614 #ifdef CONFIG_MEMCG_SWAP
5615 static int __init
enable_swap_account(char *s
)
5617 /* consider enabled if no parameter or 1 is given */
5618 if (!strcmp(s
, "1"))
5619 really_do_swap_account
= 1;
5620 else if (!strcmp(s
, "0"))
5621 really_do_swap_account
= 0;
5624 __setup("swapaccount=", enable_swap_account
);