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
);
408 /* Writing them here to avoid exposing memcg's inner layout */
409 #ifdef CONFIG_MEMCG_KMEM
410 #include <net/sock.h>
413 static bool mem_cgroup_is_root(struct mem_cgroup
*memcg
);
414 void sock_update_memcg(struct sock
*sk
)
416 if (mem_cgroup_sockets_enabled
) {
417 struct mem_cgroup
*memcg
;
418 struct cg_proto
*cg_proto
;
420 BUG_ON(!sk
->sk_prot
->proto_cgroup
);
422 /* Socket cloning can throw us here with sk_cgrp already
423 * filled. It won't however, necessarily happen from
424 * process context. So the test for root memcg given
425 * the current task's memcg won't help us in this case.
427 * Respecting the original socket's memcg is a better
428 * decision in this case.
431 BUG_ON(mem_cgroup_is_root(sk
->sk_cgrp
->memcg
));
432 mem_cgroup_get(sk
->sk_cgrp
->memcg
);
437 memcg
= mem_cgroup_from_task(current
);
438 cg_proto
= sk
->sk_prot
->proto_cgroup(memcg
);
439 if (!mem_cgroup_is_root(memcg
) && memcg_proto_active(cg_proto
)) {
440 mem_cgroup_get(memcg
);
441 sk
->sk_cgrp
= cg_proto
;
446 EXPORT_SYMBOL(sock_update_memcg
);
448 void sock_release_memcg(struct sock
*sk
)
450 if (mem_cgroup_sockets_enabled
&& sk
->sk_cgrp
) {
451 struct mem_cgroup
*memcg
;
452 WARN_ON(!sk
->sk_cgrp
->memcg
);
453 memcg
= sk
->sk_cgrp
->memcg
;
454 mem_cgroup_put(memcg
);
459 struct cg_proto
*tcp_proto_cgroup(struct mem_cgroup
*memcg
)
461 if (!memcg
|| mem_cgroup_is_root(memcg
))
464 return &memcg
->tcp_mem
.cg_proto
;
466 EXPORT_SYMBOL(tcp_proto_cgroup
);
467 #endif /* CONFIG_INET */
468 #endif /* CONFIG_MEMCG_KMEM */
470 #if defined(CONFIG_INET) && defined(CONFIG_MEMCG_KMEM)
471 static void disarm_sock_keys(struct mem_cgroup
*memcg
)
473 if (!memcg_proto_activated(&memcg
->tcp_mem
.cg_proto
))
475 static_key_slow_dec(&memcg_socket_limit_enabled
);
478 static void disarm_sock_keys(struct mem_cgroup
*memcg
)
483 static void drain_all_stock_async(struct mem_cgroup
*memcg
);
485 static struct mem_cgroup_per_zone
*
486 mem_cgroup_zoneinfo(struct mem_cgroup
*memcg
, int nid
, int zid
)
488 return &memcg
->info
.nodeinfo
[nid
]->zoneinfo
[zid
];
491 struct cgroup_subsys_state
*mem_cgroup_css(struct mem_cgroup
*memcg
)
496 static struct mem_cgroup_per_zone
*
497 page_cgroup_zoneinfo(struct mem_cgroup
*memcg
, struct page
*page
)
499 int nid
= page_to_nid(page
);
500 int zid
= page_zonenum(page
);
502 return mem_cgroup_zoneinfo(memcg
, nid
, zid
);
505 static struct mem_cgroup_tree_per_zone
*
506 soft_limit_tree_node_zone(int nid
, int zid
)
508 return &soft_limit_tree
.rb_tree_per_node
[nid
]->rb_tree_per_zone
[zid
];
511 static struct mem_cgroup_tree_per_zone
*
512 soft_limit_tree_from_page(struct page
*page
)
514 int nid
= page_to_nid(page
);
515 int zid
= page_zonenum(page
);
517 return &soft_limit_tree
.rb_tree_per_node
[nid
]->rb_tree_per_zone
[zid
];
521 __mem_cgroup_insert_exceeded(struct mem_cgroup
*memcg
,
522 struct mem_cgroup_per_zone
*mz
,
523 struct mem_cgroup_tree_per_zone
*mctz
,
524 unsigned long long new_usage_in_excess
)
526 struct rb_node
**p
= &mctz
->rb_root
.rb_node
;
527 struct rb_node
*parent
= NULL
;
528 struct mem_cgroup_per_zone
*mz_node
;
533 mz
->usage_in_excess
= new_usage_in_excess
;
534 if (!mz
->usage_in_excess
)
538 mz_node
= rb_entry(parent
, struct mem_cgroup_per_zone
,
540 if (mz
->usage_in_excess
< mz_node
->usage_in_excess
)
543 * We can't avoid mem cgroups that are over their soft
544 * limit by the same amount
546 else if (mz
->usage_in_excess
>= mz_node
->usage_in_excess
)
549 rb_link_node(&mz
->tree_node
, parent
, p
);
550 rb_insert_color(&mz
->tree_node
, &mctz
->rb_root
);
555 __mem_cgroup_remove_exceeded(struct mem_cgroup
*memcg
,
556 struct mem_cgroup_per_zone
*mz
,
557 struct mem_cgroup_tree_per_zone
*mctz
)
561 rb_erase(&mz
->tree_node
, &mctz
->rb_root
);
566 mem_cgroup_remove_exceeded(struct mem_cgroup
*memcg
,
567 struct mem_cgroup_per_zone
*mz
,
568 struct mem_cgroup_tree_per_zone
*mctz
)
570 spin_lock(&mctz
->lock
);
571 __mem_cgroup_remove_exceeded(memcg
, mz
, mctz
);
572 spin_unlock(&mctz
->lock
);
576 static void mem_cgroup_update_tree(struct mem_cgroup
*memcg
, struct page
*page
)
578 unsigned long long excess
;
579 struct mem_cgroup_per_zone
*mz
;
580 struct mem_cgroup_tree_per_zone
*mctz
;
581 int nid
= page_to_nid(page
);
582 int zid
= page_zonenum(page
);
583 mctz
= soft_limit_tree_from_page(page
);
586 * Necessary to update all ancestors when hierarchy is used.
587 * because their event counter is not touched.
589 for (; memcg
; memcg
= parent_mem_cgroup(memcg
)) {
590 mz
= mem_cgroup_zoneinfo(memcg
, nid
, zid
);
591 excess
= res_counter_soft_limit_excess(&memcg
->res
);
593 * We have to update the tree if mz is on RB-tree or
594 * mem is over its softlimit.
596 if (excess
|| mz
->on_tree
) {
597 spin_lock(&mctz
->lock
);
598 /* if on-tree, remove it */
600 __mem_cgroup_remove_exceeded(memcg
, mz
, mctz
);
602 * Insert again. mz->usage_in_excess will be updated.
603 * If excess is 0, no tree ops.
605 __mem_cgroup_insert_exceeded(memcg
, mz
, mctz
, excess
);
606 spin_unlock(&mctz
->lock
);
611 static void mem_cgroup_remove_from_trees(struct mem_cgroup
*memcg
)
614 struct mem_cgroup_per_zone
*mz
;
615 struct mem_cgroup_tree_per_zone
*mctz
;
617 for_each_node(node
) {
618 for (zone
= 0; zone
< MAX_NR_ZONES
; zone
++) {
619 mz
= mem_cgroup_zoneinfo(memcg
, node
, zone
);
620 mctz
= soft_limit_tree_node_zone(node
, zone
);
621 mem_cgroup_remove_exceeded(memcg
, mz
, mctz
);
626 static struct mem_cgroup_per_zone
*
627 __mem_cgroup_largest_soft_limit_node(struct mem_cgroup_tree_per_zone
*mctz
)
629 struct rb_node
*rightmost
= NULL
;
630 struct mem_cgroup_per_zone
*mz
;
634 rightmost
= rb_last(&mctz
->rb_root
);
636 goto done
; /* Nothing to reclaim from */
638 mz
= rb_entry(rightmost
, struct mem_cgroup_per_zone
, tree_node
);
640 * Remove the node now but someone else can add it back,
641 * we will to add it back at the end of reclaim to its correct
642 * position in the tree.
644 __mem_cgroup_remove_exceeded(mz
->memcg
, mz
, mctz
);
645 if (!res_counter_soft_limit_excess(&mz
->memcg
->res
) ||
646 !css_tryget(&mz
->memcg
->css
))
652 static struct mem_cgroup_per_zone
*
653 mem_cgroup_largest_soft_limit_node(struct mem_cgroup_tree_per_zone
*mctz
)
655 struct mem_cgroup_per_zone
*mz
;
657 spin_lock(&mctz
->lock
);
658 mz
= __mem_cgroup_largest_soft_limit_node(mctz
);
659 spin_unlock(&mctz
->lock
);
664 * Implementation Note: reading percpu statistics for memcg.
666 * Both of vmstat[] and percpu_counter has threshold and do periodic
667 * synchronization to implement "quick" read. There are trade-off between
668 * reading cost and precision of value. Then, we may have a chance to implement
669 * a periodic synchronizion of counter in memcg's counter.
671 * But this _read() function is used for user interface now. The user accounts
672 * memory usage by memory cgroup and he _always_ requires exact value because
673 * he accounts memory. Even if we provide quick-and-fuzzy read, we always
674 * have to visit all online cpus and make sum. So, for now, unnecessary
675 * synchronization is not implemented. (just implemented for cpu hotplug)
677 * If there are kernel internal actions which can make use of some not-exact
678 * value, and reading all cpu value can be performance bottleneck in some
679 * common workload, threashold and synchonization as vmstat[] should be
682 static long mem_cgroup_read_stat(struct mem_cgroup
*memcg
,
683 enum mem_cgroup_stat_index idx
)
689 for_each_online_cpu(cpu
)
690 val
+= per_cpu(memcg
->stat
->count
[idx
], cpu
);
691 #ifdef CONFIG_HOTPLUG_CPU
692 spin_lock(&memcg
->pcp_counter_lock
);
693 val
+= memcg
->nocpu_base
.count
[idx
];
694 spin_unlock(&memcg
->pcp_counter_lock
);
700 static void mem_cgroup_swap_statistics(struct mem_cgroup
*memcg
,
703 int val
= (charge
) ? 1 : -1;
704 this_cpu_add(memcg
->stat
->count
[MEM_CGROUP_STAT_SWAP
], val
);
707 static unsigned long mem_cgroup_read_events(struct mem_cgroup
*memcg
,
708 enum mem_cgroup_events_index idx
)
710 unsigned long val
= 0;
713 for_each_online_cpu(cpu
)
714 val
+= per_cpu(memcg
->stat
->events
[idx
], cpu
);
715 #ifdef CONFIG_HOTPLUG_CPU
716 spin_lock(&memcg
->pcp_counter_lock
);
717 val
+= memcg
->nocpu_base
.events
[idx
];
718 spin_unlock(&memcg
->pcp_counter_lock
);
723 static void mem_cgroup_charge_statistics(struct mem_cgroup
*memcg
,
724 bool anon
, int nr_pages
)
729 * Here, RSS means 'mapped anon' and anon's SwapCache. Shmem/tmpfs is
730 * counted as CACHE even if it's on ANON LRU.
733 __this_cpu_add(memcg
->stat
->count
[MEM_CGROUP_STAT_RSS
],
736 __this_cpu_add(memcg
->stat
->count
[MEM_CGROUP_STAT_CACHE
],
739 /* pagein of a big page is an event. So, ignore page size */
741 __this_cpu_inc(memcg
->stat
->events
[MEM_CGROUP_EVENTS_PGPGIN
]);
743 __this_cpu_inc(memcg
->stat
->events
[MEM_CGROUP_EVENTS_PGPGOUT
]);
744 nr_pages
= -nr_pages
; /* for event */
747 __this_cpu_add(memcg
->stat
->nr_page_events
, nr_pages
);
753 mem_cgroup_get_lru_size(struct lruvec
*lruvec
, enum lru_list lru
)
755 struct mem_cgroup_per_zone
*mz
;
757 mz
= container_of(lruvec
, struct mem_cgroup_per_zone
, lruvec
);
758 return mz
->lru_size
[lru
];
762 mem_cgroup_zone_nr_lru_pages(struct mem_cgroup
*memcg
, int nid
, int zid
,
763 unsigned int lru_mask
)
765 struct mem_cgroup_per_zone
*mz
;
767 unsigned long ret
= 0;
769 mz
= mem_cgroup_zoneinfo(memcg
, nid
, zid
);
772 if (BIT(lru
) & lru_mask
)
773 ret
+= mz
->lru_size
[lru
];
779 mem_cgroup_node_nr_lru_pages(struct mem_cgroup
*memcg
,
780 int nid
, unsigned int lru_mask
)
785 for (zid
= 0; zid
< MAX_NR_ZONES
; zid
++)
786 total
+= mem_cgroup_zone_nr_lru_pages(memcg
,
792 static unsigned long mem_cgroup_nr_lru_pages(struct mem_cgroup
*memcg
,
793 unsigned int lru_mask
)
798 for_each_node_state(nid
, N_HIGH_MEMORY
)
799 total
+= mem_cgroup_node_nr_lru_pages(memcg
, nid
, lru_mask
);
803 static bool mem_cgroup_event_ratelimit(struct mem_cgroup
*memcg
,
804 enum mem_cgroup_events_target target
)
806 unsigned long val
, next
;
808 val
= __this_cpu_read(memcg
->stat
->nr_page_events
);
809 next
= __this_cpu_read(memcg
->stat
->targets
[target
]);
810 /* from time_after() in jiffies.h */
811 if ((long)next
- (long)val
< 0) {
813 case MEM_CGROUP_TARGET_THRESH
:
814 next
= val
+ THRESHOLDS_EVENTS_TARGET
;
816 case MEM_CGROUP_TARGET_SOFTLIMIT
:
817 next
= val
+ SOFTLIMIT_EVENTS_TARGET
;
819 case MEM_CGROUP_TARGET_NUMAINFO
:
820 next
= val
+ NUMAINFO_EVENTS_TARGET
;
825 __this_cpu_write(memcg
->stat
->targets
[target
], next
);
832 * Check events in order.
835 static void memcg_check_events(struct mem_cgroup
*memcg
, struct page
*page
)
838 /* threshold event is triggered in finer grain than soft limit */
839 if (unlikely(mem_cgroup_event_ratelimit(memcg
,
840 MEM_CGROUP_TARGET_THRESH
))) {
842 bool do_numainfo __maybe_unused
;
844 do_softlimit
= mem_cgroup_event_ratelimit(memcg
,
845 MEM_CGROUP_TARGET_SOFTLIMIT
);
847 do_numainfo
= mem_cgroup_event_ratelimit(memcg
,
848 MEM_CGROUP_TARGET_NUMAINFO
);
852 mem_cgroup_threshold(memcg
);
853 if (unlikely(do_softlimit
))
854 mem_cgroup_update_tree(memcg
, page
);
856 if (unlikely(do_numainfo
))
857 atomic_inc(&memcg
->numainfo_events
);
863 struct mem_cgroup
*mem_cgroup_from_cont(struct cgroup
*cont
)
865 return container_of(cgroup_subsys_state(cont
,
866 mem_cgroup_subsys_id
), struct mem_cgroup
,
870 struct mem_cgroup
*mem_cgroup_from_task(struct task_struct
*p
)
873 * mm_update_next_owner() may clear mm->owner to NULL
874 * if it races with swapoff, page migration, etc.
875 * So this can be called with p == NULL.
880 return container_of(task_subsys_state(p
, mem_cgroup_subsys_id
),
881 struct mem_cgroup
, css
);
884 struct mem_cgroup
*try_get_mem_cgroup_from_mm(struct mm_struct
*mm
)
886 struct mem_cgroup
*memcg
= NULL
;
891 * Because we have no locks, mm->owner's may be being moved to other
892 * cgroup. We use css_tryget() here even if this looks
893 * pessimistic (rather than adding locks here).
897 memcg
= mem_cgroup_from_task(rcu_dereference(mm
->owner
));
898 if (unlikely(!memcg
))
900 } while (!css_tryget(&memcg
->css
));
906 * mem_cgroup_iter - iterate over memory cgroup hierarchy
907 * @root: hierarchy root
908 * @prev: previously returned memcg, NULL on first invocation
909 * @reclaim: cookie for shared reclaim walks, NULL for full walks
911 * Returns references to children of the hierarchy below @root, or
912 * @root itself, or %NULL after a full round-trip.
914 * Caller must pass the return value in @prev on subsequent
915 * invocations for reference counting, or use mem_cgroup_iter_break()
916 * to cancel a hierarchy walk before the round-trip is complete.
918 * Reclaimers can specify a zone and a priority level in @reclaim to
919 * divide up the memcgs in the hierarchy among all concurrent
920 * reclaimers operating on the same zone and priority.
922 struct mem_cgroup
*mem_cgroup_iter(struct mem_cgroup
*root
,
923 struct mem_cgroup
*prev
,
924 struct mem_cgroup_reclaim_cookie
*reclaim
)
926 struct mem_cgroup
*memcg
= NULL
;
929 if (mem_cgroup_disabled())
933 root
= root_mem_cgroup
;
935 if (prev
&& !reclaim
)
936 id
= css_id(&prev
->css
);
938 if (prev
&& prev
!= root
)
941 if (!root
->use_hierarchy
&& root
!= root_mem_cgroup
) {
948 struct mem_cgroup_reclaim_iter
*uninitialized_var(iter
);
949 struct cgroup_subsys_state
*css
;
952 int nid
= zone_to_nid(reclaim
->zone
);
953 int zid
= zone_idx(reclaim
->zone
);
954 struct mem_cgroup_per_zone
*mz
;
956 mz
= mem_cgroup_zoneinfo(root
, nid
, zid
);
957 iter
= &mz
->reclaim_iter
[reclaim
->priority
];
958 if (prev
&& reclaim
->generation
!= iter
->generation
)
964 css
= css_get_next(&mem_cgroup_subsys
, id
+ 1, &root
->css
, &id
);
966 if (css
== &root
->css
|| css_tryget(css
))
967 memcg
= container_of(css
,
968 struct mem_cgroup
, css
);
977 else if (!prev
&& memcg
)
978 reclaim
->generation
= iter
->generation
;
988 * mem_cgroup_iter_break - abort a hierarchy walk prematurely
989 * @root: hierarchy root
990 * @prev: last visited hierarchy member as returned by mem_cgroup_iter()
992 void mem_cgroup_iter_break(struct mem_cgroup
*root
,
993 struct mem_cgroup
*prev
)
996 root
= root_mem_cgroup
;
997 if (prev
&& prev
!= root
)
1002 * Iteration constructs for visiting all cgroups (under a tree). If
1003 * loops are exited prematurely (break), mem_cgroup_iter_break() must
1004 * be used for reference counting.
1006 #define for_each_mem_cgroup_tree(iter, root) \
1007 for (iter = mem_cgroup_iter(root, NULL, NULL); \
1009 iter = mem_cgroup_iter(root, iter, NULL))
1011 #define for_each_mem_cgroup(iter) \
1012 for (iter = mem_cgroup_iter(NULL, NULL, NULL); \
1014 iter = mem_cgroup_iter(NULL, iter, NULL))
1016 static inline bool mem_cgroup_is_root(struct mem_cgroup
*memcg
)
1018 return (memcg
== root_mem_cgroup
);
1021 void mem_cgroup_count_vm_event(struct mm_struct
*mm
, enum vm_event_item idx
)
1023 struct mem_cgroup
*memcg
;
1029 memcg
= mem_cgroup_from_task(rcu_dereference(mm
->owner
));
1030 if (unlikely(!memcg
))
1035 this_cpu_inc(memcg
->stat
->events
[MEM_CGROUP_EVENTS_PGFAULT
]);
1038 this_cpu_inc(memcg
->stat
->events
[MEM_CGROUP_EVENTS_PGMAJFAULT
]);
1046 EXPORT_SYMBOL(mem_cgroup_count_vm_event
);
1049 * mem_cgroup_zone_lruvec - get the lru list vector for a zone and memcg
1050 * @zone: zone of the wanted lruvec
1051 * @memcg: memcg of the wanted lruvec
1053 * Returns the lru list vector holding pages for the given @zone and
1054 * @mem. This can be the global zone lruvec, if the memory controller
1057 struct lruvec
*mem_cgroup_zone_lruvec(struct zone
*zone
,
1058 struct mem_cgroup
*memcg
)
1060 struct mem_cgroup_per_zone
*mz
;
1062 if (mem_cgroup_disabled())
1063 return &zone
->lruvec
;
1065 mz
= mem_cgroup_zoneinfo(memcg
, zone_to_nid(zone
), zone_idx(zone
));
1070 * Following LRU functions are allowed to be used without PCG_LOCK.
1071 * Operations are called by routine of global LRU independently from memcg.
1072 * What we have to take care of here is validness of pc->mem_cgroup.
1074 * Changes to pc->mem_cgroup happens when
1077 * In typical case, "charge" is done before add-to-lru. Exception is SwapCache.
1078 * It is added to LRU before charge.
1079 * If PCG_USED bit is not set, page_cgroup is not added to this private LRU.
1080 * When moving account, the page is not on LRU. It's isolated.
1084 * mem_cgroup_page_lruvec - return lruvec for adding an lru page
1086 * @zone: zone of the page
1088 struct lruvec
*mem_cgroup_page_lruvec(struct page
*page
, struct zone
*zone
)
1090 struct mem_cgroup_per_zone
*mz
;
1091 struct mem_cgroup
*memcg
;
1092 struct page_cgroup
*pc
;
1094 if (mem_cgroup_disabled())
1095 return &zone
->lruvec
;
1097 pc
= lookup_page_cgroup(page
);
1098 memcg
= pc
->mem_cgroup
;
1101 * Surreptitiously switch any uncharged offlist page to root:
1102 * an uncharged page off lru does nothing to secure
1103 * its former mem_cgroup from sudden removal.
1105 * Our caller holds lru_lock, and PageCgroupUsed is updated
1106 * under page_cgroup lock: between them, they make all uses
1107 * of pc->mem_cgroup safe.
1109 if (!PageLRU(page
) && !PageCgroupUsed(pc
) && memcg
!= root_mem_cgroup
)
1110 pc
->mem_cgroup
= memcg
= root_mem_cgroup
;
1112 mz
= page_cgroup_zoneinfo(memcg
, page
);
1117 * mem_cgroup_update_lru_size - account for adding or removing an lru page
1118 * @lruvec: mem_cgroup per zone lru vector
1119 * @lru: index of lru list the page is sitting on
1120 * @nr_pages: positive when adding or negative when removing
1122 * This function must be called when a page is added to or removed from an
1125 void mem_cgroup_update_lru_size(struct lruvec
*lruvec
, enum lru_list lru
,
1128 struct mem_cgroup_per_zone
*mz
;
1129 unsigned long *lru_size
;
1131 if (mem_cgroup_disabled())
1134 mz
= container_of(lruvec
, struct mem_cgroup_per_zone
, lruvec
);
1135 lru_size
= mz
->lru_size
+ lru
;
1136 *lru_size
+= nr_pages
;
1137 VM_BUG_ON((long)(*lru_size
) < 0);
1141 * Checks whether given mem is same or in the root_mem_cgroup's
1144 bool __mem_cgroup_same_or_subtree(const struct mem_cgroup
*root_memcg
,
1145 struct mem_cgroup
*memcg
)
1147 if (root_memcg
== memcg
)
1149 if (!root_memcg
->use_hierarchy
|| !memcg
)
1151 return css_is_ancestor(&memcg
->css
, &root_memcg
->css
);
1154 static bool mem_cgroup_same_or_subtree(const struct mem_cgroup
*root_memcg
,
1155 struct mem_cgroup
*memcg
)
1160 ret
= __mem_cgroup_same_or_subtree(root_memcg
, memcg
);
1165 int task_in_mem_cgroup(struct task_struct
*task
, const struct mem_cgroup
*memcg
)
1168 struct mem_cgroup
*curr
= NULL
;
1169 struct task_struct
*p
;
1171 p
= find_lock_task_mm(task
);
1173 curr
= try_get_mem_cgroup_from_mm(p
->mm
);
1177 * All threads may have already detached their mm's, but the oom
1178 * killer still needs to detect if they have already been oom
1179 * killed to prevent needlessly killing additional tasks.
1182 curr
= mem_cgroup_from_task(task
);
1184 css_get(&curr
->css
);
1190 * We should check use_hierarchy of "memcg" not "curr". Because checking
1191 * use_hierarchy of "curr" here make this function true if hierarchy is
1192 * enabled in "curr" and "curr" is a child of "memcg" in *cgroup*
1193 * hierarchy(even if use_hierarchy is disabled in "memcg").
1195 ret
= mem_cgroup_same_or_subtree(memcg
, curr
);
1196 css_put(&curr
->css
);
1200 int mem_cgroup_inactive_anon_is_low(struct lruvec
*lruvec
)
1202 unsigned long inactive_ratio
;
1203 unsigned long inactive
;
1204 unsigned long active
;
1207 inactive
= mem_cgroup_get_lru_size(lruvec
, LRU_INACTIVE_ANON
);
1208 active
= mem_cgroup_get_lru_size(lruvec
, LRU_ACTIVE_ANON
);
1210 gb
= (inactive
+ active
) >> (30 - PAGE_SHIFT
);
1212 inactive_ratio
= int_sqrt(10 * gb
);
1216 return inactive
* inactive_ratio
< active
;
1219 int mem_cgroup_inactive_file_is_low(struct lruvec
*lruvec
)
1221 unsigned long active
;
1222 unsigned long inactive
;
1224 inactive
= mem_cgroup_get_lru_size(lruvec
, LRU_INACTIVE_FILE
);
1225 active
= mem_cgroup_get_lru_size(lruvec
, LRU_ACTIVE_FILE
);
1227 return (active
> inactive
);
1230 #define mem_cgroup_from_res_counter(counter, member) \
1231 container_of(counter, struct mem_cgroup, member)
1234 * mem_cgroup_margin - calculate chargeable space of a memory cgroup
1235 * @memcg: the memory cgroup
1237 * Returns the maximum amount of memory @mem can be charged with, in
1240 static unsigned long mem_cgroup_margin(struct mem_cgroup
*memcg
)
1242 unsigned long long margin
;
1244 margin
= res_counter_margin(&memcg
->res
);
1245 if (do_swap_account
)
1246 margin
= min(margin
, res_counter_margin(&memcg
->memsw
));
1247 return margin
>> PAGE_SHIFT
;
1250 int mem_cgroup_swappiness(struct mem_cgroup
*memcg
)
1252 struct cgroup
*cgrp
= memcg
->css
.cgroup
;
1255 if (cgrp
->parent
== NULL
)
1256 return vm_swappiness
;
1258 return memcg
->swappiness
;
1262 * memcg->moving_account is used for checking possibility that some thread is
1263 * calling move_account(). When a thread on CPU-A starts moving pages under
1264 * a memcg, other threads should check memcg->moving_account under
1265 * rcu_read_lock(), like this:
1269 * memcg->moving_account+1 if (memcg->mocing_account)
1271 * synchronize_rcu() update something.
1276 /* for quick checking without looking up memcg */
1277 atomic_t memcg_moving __read_mostly
;
1279 static void mem_cgroup_start_move(struct mem_cgroup
*memcg
)
1281 atomic_inc(&memcg_moving
);
1282 atomic_inc(&memcg
->moving_account
);
1286 static void mem_cgroup_end_move(struct mem_cgroup
*memcg
)
1289 * Now, mem_cgroup_clear_mc() may call this function with NULL.
1290 * We check NULL in callee rather than caller.
1293 atomic_dec(&memcg_moving
);
1294 atomic_dec(&memcg
->moving_account
);
1299 * 2 routines for checking "mem" is under move_account() or not.
1301 * mem_cgroup_stolen() - checking whether a cgroup is mc.from or not. This
1302 * is used for avoiding races in accounting. If true,
1303 * pc->mem_cgroup may be overwritten.
1305 * mem_cgroup_under_move() - checking a cgroup is mc.from or mc.to or
1306 * under hierarchy of moving cgroups. This is for
1307 * waiting at hith-memory prressure caused by "move".
1310 static bool mem_cgroup_stolen(struct mem_cgroup
*memcg
)
1312 VM_BUG_ON(!rcu_read_lock_held());
1313 return atomic_read(&memcg
->moving_account
) > 0;
1316 static bool mem_cgroup_under_move(struct mem_cgroup
*memcg
)
1318 struct mem_cgroup
*from
;
1319 struct mem_cgroup
*to
;
1322 * Unlike task_move routines, we access mc.to, mc.from not under
1323 * mutual exclusion by cgroup_mutex. Here, we take spinlock instead.
1325 spin_lock(&mc
.lock
);
1331 ret
= mem_cgroup_same_or_subtree(memcg
, from
)
1332 || mem_cgroup_same_or_subtree(memcg
, to
);
1334 spin_unlock(&mc
.lock
);
1338 static bool mem_cgroup_wait_acct_move(struct mem_cgroup
*memcg
)
1340 if (mc
.moving_task
&& current
!= mc
.moving_task
) {
1341 if (mem_cgroup_under_move(memcg
)) {
1343 prepare_to_wait(&mc
.waitq
, &wait
, TASK_INTERRUPTIBLE
);
1344 /* moving charge context might have finished. */
1347 finish_wait(&mc
.waitq
, &wait
);
1355 * Take this lock when
1356 * - a code tries to modify page's memcg while it's USED.
1357 * - a code tries to modify page state accounting in a memcg.
1358 * see mem_cgroup_stolen(), too.
1360 static void move_lock_mem_cgroup(struct mem_cgroup
*memcg
,
1361 unsigned long *flags
)
1363 spin_lock_irqsave(&memcg
->move_lock
, *flags
);
1366 static void move_unlock_mem_cgroup(struct mem_cgroup
*memcg
,
1367 unsigned long *flags
)
1369 spin_unlock_irqrestore(&memcg
->move_lock
, *flags
);
1373 * mem_cgroup_print_oom_info: Called from OOM with tasklist_lock held in read mode.
1374 * @memcg: The memory cgroup that went over limit
1375 * @p: Task that is going to be killed
1377 * NOTE: @memcg and @p's mem_cgroup can be different when hierarchy is
1380 void mem_cgroup_print_oom_info(struct mem_cgroup
*memcg
, struct task_struct
*p
)
1382 struct cgroup
*task_cgrp
;
1383 struct cgroup
*mem_cgrp
;
1385 * Need a buffer in BSS, can't rely on allocations. The code relies
1386 * on the assumption that OOM is serialized for memory controller.
1387 * If this assumption is broken, revisit this code.
1389 static char memcg_name
[PATH_MAX
];
1397 mem_cgrp
= memcg
->css
.cgroup
;
1398 task_cgrp
= task_cgroup(p
, mem_cgroup_subsys_id
);
1400 ret
= cgroup_path(task_cgrp
, memcg_name
, PATH_MAX
);
1403 * Unfortunately, we are unable to convert to a useful name
1404 * But we'll still print out the usage information
1411 printk(KERN_INFO
"Task in %s killed", memcg_name
);
1414 ret
= cgroup_path(mem_cgrp
, memcg_name
, PATH_MAX
);
1422 * Continues from above, so we don't need an KERN_ level
1424 printk(KERN_CONT
" as a result of limit of %s\n", memcg_name
);
1427 printk(KERN_INFO
"memory: usage %llukB, limit %llukB, failcnt %llu\n",
1428 res_counter_read_u64(&memcg
->res
, RES_USAGE
) >> 10,
1429 res_counter_read_u64(&memcg
->res
, RES_LIMIT
) >> 10,
1430 res_counter_read_u64(&memcg
->res
, RES_FAILCNT
));
1431 printk(KERN_INFO
"memory+swap: usage %llukB, limit %llukB, "
1433 res_counter_read_u64(&memcg
->memsw
, RES_USAGE
) >> 10,
1434 res_counter_read_u64(&memcg
->memsw
, RES_LIMIT
) >> 10,
1435 res_counter_read_u64(&memcg
->memsw
, RES_FAILCNT
));
1439 * This function returns the number of memcg under hierarchy tree. Returns
1440 * 1(self count) if no children.
1442 static int mem_cgroup_count_children(struct mem_cgroup
*memcg
)
1445 struct mem_cgroup
*iter
;
1447 for_each_mem_cgroup_tree(iter
, memcg
)
1453 * Return the memory (and swap, if configured) limit for a memcg.
1455 static u64
mem_cgroup_get_limit(struct mem_cgroup
*memcg
)
1460 limit
= res_counter_read_u64(&memcg
->res
, RES_LIMIT
);
1461 limit
+= total_swap_pages
<< PAGE_SHIFT
;
1463 memsw
= res_counter_read_u64(&memcg
->memsw
, RES_LIMIT
);
1465 * If memsw is finite and limits the amount of swap space available
1466 * to this memcg, return that limit.
1468 return min(limit
, memsw
);
1471 void mem_cgroup_out_of_memory(struct mem_cgroup
*memcg
, gfp_t gfp_mask
,
1474 struct mem_cgroup
*iter
;
1475 unsigned long chosen_points
= 0;
1476 unsigned long totalpages
;
1477 unsigned int points
= 0;
1478 struct task_struct
*chosen
= NULL
;
1481 * If current has a pending SIGKILL, then automatically select it. The
1482 * goal is to allow it to allocate so that it may quickly exit and free
1485 if (fatal_signal_pending(current
)) {
1486 set_thread_flag(TIF_MEMDIE
);
1490 check_panic_on_oom(CONSTRAINT_MEMCG
, gfp_mask
, order
, NULL
);
1491 totalpages
= mem_cgroup_get_limit(memcg
) >> PAGE_SHIFT
? : 1;
1492 for_each_mem_cgroup_tree(iter
, memcg
) {
1493 struct cgroup
*cgroup
= iter
->css
.cgroup
;
1494 struct cgroup_iter it
;
1495 struct task_struct
*task
;
1497 cgroup_iter_start(cgroup
, &it
);
1498 while ((task
= cgroup_iter_next(cgroup
, &it
))) {
1499 switch (oom_scan_process_thread(task
, totalpages
, NULL
,
1501 case OOM_SCAN_SELECT
:
1503 put_task_struct(chosen
);
1505 chosen_points
= ULONG_MAX
;
1506 get_task_struct(chosen
);
1508 case OOM_SCAN_CONTINUE
:
1510 case OOM_SCAN_ABORT
:
1511 cgroup_iter_end(cgroup
, &it
);
1512 mem_cgroup_iter_break(memcg
, iter
);
1514 put_task_struct(chosen
);
1519 points
= oom_badness(task
, memcg
, NULL
, totalpages
);
1520 if (points
> chosen_points
) {
1522 put_task_struct(chosen
);
1524 chosen_points
= points
;
1525 get_task_struct(chosen
);
1528 cgroup_iter_end(cgroup
, &it
);
1533 points
= chosen_points
* 1000 / totalpages
;
1534 oom_kill_process(chosen
, gfp_mask
, order
, points
, totalpages
, memcg
,
1535 NULL
, "Memory cgroup out of memory");
1538 static unsigned long mem_cgroup_reclaim(struct mem_cgroup
*memcg
,
1540 unsigned long flags
)
1542 unsigned long total
= 0;
1543 bool noswap
= false;
1546 if (flags
& MEM_CGROUP_RECLAIM_NOSWAP
)
1548 if (!(flags
& MEM_CGROUP_RECLAIM_SHRINK
) && memcg
->memsw_is_minimum
)
1551 for (loop
= 0; loop
< MEM_CGROUP_MAX_RECLAIM_LOOPS
; loop
++) {
1553 drain_all_stock_async(memcg
);
1554 total
+= try_to_free_mem_cgroup_pages(memcg
, gfp_mask
, noswap
);
1556 * Allow limit shrinkers, which are triggered directly
1557 * by userspace, to catch signals and stop reclaim
1558 * after minimal progress, regardless of the margin.
1560 if (total
&& (flags
& MEM_CGROUP_RECLAIM_SHRINK
))
1562 if (mem_cgroup_margin(memcg
))
1565 * If nothing was reclaimed after two attempts, there
1566 * may be no reclaimable pages in this hierarchy.
1575 * test_mem_cgroup_node_reclaimable
1576 * @memcg: the target memcg
1577 * @nid: the node ID to be checked.
1578 * @noswap : specify true here if the user wants flle only information.
1580 * This function returns whether the specified memcg contains any
1581 * reclaimable pages on a node. Returns true if there are any reclaimable
1582 * pages in the node.
1584 static bool test_mem_cgroup_node_reclaimable(struct mem_cgroup
*memcg
,
1585 int nid
, bool noswap
)
1587 if (mem_cgroup_node_nr_lru_pages(memcg
, nid
, LRU_ALL_FILE
))
1589 if (noswap
|| !total_swap_pages
)
1591 if (mem_cgroup_node_nr_lru_pages(memcg
, nid
, LRU_ALL_ANON
))
1596 #if MAX_NUMNODES > 1
1599 * Always updating the nodemask is not very good - even if we have an empty
1600 * list or the wrong list here, we can start from some node and traverse all
1601 * nodes based on the zonelist. So update the list loosely once per 10 secs.
1604 static void mem_cgroup_may_update_nodemask(struct mem_cgroup
*memcg
)
1608 * numainfo_events > 0 means there was at least NUMAINFO_EVENTS_TARGET
1609 * pagein/pageout changes since the last update.
1611 if (!atomic_read(&memcg
->numainfo_events
))
1613 if (atomic_inc_return(&memcg
->numainfo_updating
) > 1)
1616 /* make a nodemask where this memcg uses memory from */
1617 memcg
->scan_nodes
= node_states
[N_HIGH_MEMORY
];
1619 for_each_node_mask(nid
, node_states
[N_HIGH_MEMORY
]) {
1621 if (!test_mem_cgroup_node_reclaimable(memcg
, nid
, false))
1622 node_clear(nid
, memcg
->scan_nodes
);
1625 atomic_set(&memcg
->numainfo_events
, 0);
1626 atomic_set(&memcg
->numainfo_updating
, 0);
1630 * Selecting a node where we start reclaim from. Because what we need is just
1631 * reducing usage counter, start from anywhere is O,K. Considering
1632 * memory reclaim from current node, there are pros. and cons.
1634 * Freeing memory from current node means freeing memory from a node which
1635 * we'll use or we've used. So, it may make LRU bad. And if several threads
1636 * hit limits, it will see a contention on a node. But freeing from remote
1637 * node means more costs for memory reclaim because of memory latency.
1639 * Now, we use round-robin. Better algorithm is welcomed.
1641 int mem_cgroup_select_victim_node(struct mem_cgroup
*memcg
)
1645 mem_cgroup_may_update_nodemask(memcg
);
1646 node
= memcg
->last_scanned_node
;
1648 node
= next_node(node
, memcg
->scan_nodes
);
1649 if (node
== MAX_NUMNODES
)
1650 node
= first_node(memcg
->scan_nodes
);
1652 * We call this when we hit limit, not when pages are added to LRU.
1653 * No LRU may hold pages because all pages are UNEVICTABLE or
1654 * memcg is too small and all pages are not on LRU. In that case,
1655 * we use curret node.
1657 if (unlikely(node
== MAX_NUMNODES
))
1658 node
= numa_node_id();
1660 memcg
->last_scanned_node
= node
;
1665 * Check all nodes whether it contains reclaimable pages or not.
1666 * For quick scan, we make use of scan_nodes. This will allow us to skip
1667 * unused nodes. But scan_nodes is lazily updated and may not cotain
1668 * enough new information. We need to do double check.
1670 static bool mem_cgroup_reclaimable(struct mem_cgroup
*memcg
, bool noswap
)
1675 * quick check...making use of scan_node.
1676 * We can skip unused nodes.
1678 if (!nodes_empty(memcg
->scan_nodes
)) {
1679 for (nid
= first_node(memcg
->scan_nodes
);
1681 nid
= next_node(nid
, memcg
->scan_nodes
)) {
1683 if (test_mem_cgroup_node_reclaimable(memcg
, nid
, noswap
))
1688 * Check rest of nodes.
1690 for_each_node_state(nid
, N_HIGH_MEMORY
) {
1691 if (node_isset(nid
, memcg
->scan_nodes
))
1693 if (test_mem_cgroup_node_reclaimable(memcg
, nid
, noswap
))
1700 int mem_cgroup_select_victim_node(struct mem_cgroup
*memcg
)
1705 static bool mem_cgroup_reclaimable(struct mem_cgroup
*memcg
, bool noswap
)
1707 return test_mem_cgroup_node_reclaimable(memcg
, 0, noswap
);
1711 static int mem_cgroup_soft_reclaim(struct mem_cgroup
*root_memcg
,
1714 unsigned long *total_scanned
)
1716 struct mem_cgroup
*victim
= NULL
;
1719 unsigned long excess
;
1720 unsigned long nr_scanned
;
1721 struct mem_cgroup_reclaim_cookie reclaim
= {
1726 excess
= res_counter_soft_limit_excess(&root_memcg
->res
) >> PAGE_SHIFT
;
1729 victim
= mem_cgroup_iter(root_memcg
, victim
, &reclaim
);
1734 * If we have not been able to reclaim
1735 * anything, it might because there are
1736 * no reclaimable pages under this hierarchy
1741 * We want to do more targeted reclaim.
1742 * excess >> 2 is not to excessive so as to
1743 * reclaim too much, nor too less that we keep
1744 * coming back to reclaim from this cgroup
1746 if (total
>= (excess
>> 2) ||
1747 (loop
> MEM_CGROUP_MAX_RECLAIM_LOOPS
))
1752 if (!mem_cgroup_reclaimable(victim
, false))
1754 total
+= mem_cgroup_shrink_node_zone(victim
, gfp_mask
, false,
1756 *total_scanned
+= nr_scanned
;
1757 if (!res_counter_soft_limit_excess(&root_memcg
->res
))
1760 mem_cgroup_iter_break(root_memcg
, victim
);
1765 * Check OOM-Killer is already running under our hierarchy.
1766 * If someone is running, return false.
1767 * Has to be called with memcg_oom_lock
1769 static bool mem_cgroup_oom_lock(struct mem_cgroup
*memcg
)
1771 struct mem_cgroup
*iter
, *failed
= NULL
;
1773 for_each_mem_cgroup_tree(iter
, memcg
) {
1774 if (iter
->oom_lock
) {
1776 * this subtree of our hierarchy is already locked
1777 * so we cannot give a lock.
1780 mem_cgroup_iter_break(memcg
, iter
);
1783 iter
->oom_lock
= true;
1790 * OK, we failed to lock the whole subtree so we have to clean up
1791 * what we set up to the failing subtree
1793 for_each_mem_cgroup_tree(iter
, memcg
) {
1794 if (iter
== failed
) {
1795 mem_cgroup_iter_break(memcg
, iter
);
1798 iter
->oom_lock
= false;
1804 * Has to be called with memcg_oom_lock
1806 static int mem_cgroup_oom_unlock(struct mem_cgroup
*memcg
)
1808 struct mem_cgroup
*iter
;
1810 for_each_mem_cgroup_tree(iter
, memcg
)
1811 iter
->oom_lock
= false;
1815 static void mem_cgroup_mark_under_oom(struct mem_cgroup
*memcg
)
1817 struct mem_cgroup
*iter
;
1819 for_each_mem_cgroup_tree(iter
, memcg
)
1820 atomic_inc(&iter
->under_oom
);
1823 static void mem_cgroup_unmark_under_oom(struct mem_cgroup
*memcg
)
1825 struct mem_cgroup
*iter
;
1828 * When a new child is created while the hierarchy is under oom,
1829 * mem_cgroup_oom_lock() may not be called. We have to use
1830 * atomic_add_unless() here.
1832 for_each_mem_cgroup_tree(iter
, memcg
)
1833 atomic_add_unless(&iter
->under_oom
, -1, 0);
1836 static DEFINE_SPINLOCK(memcg_oom_lock
);
1837 static DECLARE_WAIT_QUEUE_HEAD(memcg_oom_waitq
);
1839 struct oom_wait_info
{
1840 struct mem_cgroup
*memcg
;
1844 static int memcg_oom_wake_function(wait_queue_t
*wait
,
1845 unsigned mode
, int sync
, void *arg
)
1847 struct mem_cgroup
*wake_memcg
= (struct mem_cgroup
*)arg
;
1848 struct mem_cgroup
*oom_wait_memcg
;
1849 struct oom_wait_info
*oom_wait_info
;
1851 oom_wait_info
= container_of(wait
, struct oom_wait_info
, wait
);
1852 oom_wait_memcg
= oom_wait_info
->memcg
;
1855 * Both of oom_wait_info->memcg and wake_memcg are stable under us.
1856 * Then we can use css_is_ancestor without taking care of RCU.
1858 if (!mem_cgroup_same_or_subtree(oom_wait_memcg
, wake_memcg
)
1859 && !mem_cgroup_same_or_subtree(wake_memcg
, oom_wait_memcg
))
1861 return autoremove_wake_function(wait
, mode
, sync
, arg
);
1864 static void memcg_wakeup_oom(struct mem_cgroup
*memcg
)
1866 /* for filtering, pass "memcg" as argument. */
1867 __wake_up(&memcg_oom_waitq
, TASK_NORMAL
, 0, memcg
);
1870 static void memcg_oom_recover(struct mem_cgroup
*memcg
)
1872 if (memcg
&& atomic_read(&memcg
->under_oom
))
1873 memcg_wakeup_oom(memcg
);
1877 * try to call OOM killer. returns false if we should exit memory-reclaim loop.
1879 static bool mem_cgroup_handle_oom(struct mem_cgroup
*memcg
, gfp_t mask
,
1882 struct oom_wait_info owait
;
1883 bool locked
, need_to_kill
;
1885 owait
.memcg
= memcg
;
1886 owait
.wait
.flags
= 0;
1887 owait
.wait
.func
= memcg_oom_wake_function
;
1888 owait
.wait
.private = current
;
1889 INIT_LIST_HEAD(&owait
.wait
.task_list
);
1890 need_to_kill
= true;
1891 mem_cgroup_mark_under_oom(memcg
);
1893 /* At first, try to OOM lock hierarchy under memcg.*/
1894 spin_lock(&memcg_oom_lock
);
1895 locked
= mem_cgroup_oom_lock(memcg
);
1897 * Even if signal_pending(), we can't quit charge() loop without
1898 * accounting. So, UNINTERRUPTIBLE is appropriate. But SIGKILL
1899 * under OOM is always welcomed, use TASK_KILLABLE here.
1901 prepare_to_wait(&memcg_oom_waitq
, &owait
.wait
, TASK_KILLABLE
);
1902 if (!locked
|| memcg
->oom_kill_disable
)
1903 need_to_kill
= false;
1905 mem_cgroup_oom_notify(memcg
);
1906 spin_unlock(&memcg_oom_lock
);
1909 finish_wait(&memcg_oom_waitq
, &owait
.wait
);
1910 mem_cgroup_out_of_memory(memcg
, mask
, order
);
1913 finish_wait(&memcg_oom_waitq
, &owait
.wait
);
1915 spin_lock(&memcg_oom_lock
);
1917 mem_cgroup_oom_unlock(memcg
);
1918 memcg_wakeup_oom(memcg
);
1919 spin_unlock(&memcg_oom_lock
);
1921 mem_cgroup_unmark_under_oom(memcg
);
1923 if (test_thread_flag(TIF_MEMDIE
) || fatal_signal_pending(current
))
1925 /* Give chance to dying process */
1926 schedule_timeout_uninterruptible(1);
1931 * Currently used to update mapped file statistics, but the routine can be
1932 * generalized to update other statistics as well.
1934 * Notes: Race condition
1936 * We usually use page_cgroup_lock() for accessing page_cgroup member but
1937 * it tends to be costly. But considering some conditions, we doesn't need
1938 * to do so _always_.
1940 * Considering "charge", lock_page_cgroup() is not required because all
1941 * file-stat operations happen after a page is attached to radix-tree. There
1942 * are no race with "charge".
1944 * Considering "uncharge", we know that memcg doesn't clear pc->mem_cgroup
1945 * at "uncharge" intentionally. So, we always see valid pc->mem_cgroup even
1946 * if there are race with "uncharge". Statistics itself is properly handled
1949 * Considering "move", this is an only case we see a race. To make the race
1950 * small, we check mm->moving_account and detect there are possibility of race
1951 * If there is, we take a lock.
1954 void __mem_cgroup_begin_update_page_stat(struct page
*page
,
1955 bool *locked
, unsigned long *flags
)
1957 struct mem_cgroup
*memcg
;
1958 struct page_cgroup
*pc
;
1960 pc
= lookup_page_cgroup(page
);
1962 memcg
= pc
->mem_cgroup
;
1963 if (unlikely(!memcg
|| !PageCgroupUsed(pc
)))
1966 * If this memory cgroup is not under account moving, we don't
1967 * need to take move_lock_mem_cgroup(). Because we already hold
1968 * rcu_read_lock(), any calls to move_account will be delayed until
1969 * rcu_read_unlock() if mem_cgroup_stolen() == true.
1971 if (!mem_cgroup_stolen(memcg
))
1974 move_lock_mem_cgroup(memcg
, flags
);
1975 if (memcg
!= pc
->mem_cgroup
|| !PageCgroupUsed(pc
)) {
1976 move_unlock_mem_cgroup(memcg
, flags
);
1982 void __mem_cgroup_end_update_page_stat(struct page
*page
, unsigned long *flags
)
1984 struct page_cgroup
*pc
= lookup_page_cgroup(page
);
1987 * It's guaranteed that pc->mem_cgroup never changes while
1988 * lock is held because a routine modifies pc->mem_cgroup
1989 * should take move_lock_mem_cgroup().
1991 move_unlock_mem_cgroup(pc
->mem_cgroup
, flags
);
1994 void mem_cgroup_update_page_stat(struct page
*page
,
1995 enum mem_cgroup_page_stat_item idx
, int val
)
1997 struct mem_cgroup
*memcg
;
1998 struct page_cgroup
*pc
= lookup_page_cgroup(page
);
1999 unsigned long uninitialized_var(flags
);
2001 if (mem_cgroup_disabled())
2004 memcg
= pc
->mem_cgroup
;
2005 if (unlikely(!memcg
|| !PageCgroupUsed(pc
)))
2009 case MEMCG_NR_FILE_MAPPED
:
2010 idx
= MEM_CGROUP_STAT_FILE_MAPPED
;
2016 this_cpu_add(memcg
->stat
->count
[idx
], val
);
2020 * size of first charge trial. "32" comes from vmscan.c's magic value.
2021 * TODO: maybe necessary to use big numbers in big irons.
2023 #define CHARGE_BATCH 32U
2024 struct memcg_stock_pcp
{
2025 struct mem_cgroup
*cached
; /* this never be root cgroup */
2026 unsigned int nr_pages
;
2027 struct work_struct work
;
2028 unsigned long flags
;
2029 #define FLUSHING_CACHED_CHARGE 0
2031 static DEFINE_PER_CPU(struct memcg_stock_pcp
, memcg_stock
);
2032 static DEFINE_MUTEX(percpu_charge_mutex
);
2035 * Try to consume stocked charge on this cpu. If success, one page is consumed
2036 * from local stock and true is returned. If the stock is 0 or charges from a
2037 * cgroup which is not current target, returns false. This stock will be
2040 static bool consume_stock(struct mem_cgroup
*memcg
)
2042 struct memcg_stock_pcp
*stock
;
2045 stock
= &get_cpu_var(memcg_stock
);
2046 if (memcg
== stock
->cached
&& stock
->nr_pages
)
2048 else /* need to call res_counter_charge */
2050 put_cpu_var(memcg_stock
);
2055 * Returns stocks cached in percpu to res_counter and reset cached information.
2057 static void drain_stock(struct memcg_stock_pcp
*stock
)
2059 struct mem_cgroup
*old
= stock
->cached
;
2061 if (stock
->nr_pages
) {
2062 unsigned long bytes
= stock
->nr_pages
* PAGE_SIZE
;
2064 res_counter_uncharge(&old
->res
, bytes
);
2065 if (do_swap_account
)
2066 res_counter_uncharge(&old
->memsw
, bytes
);
2067 stock
->nr_pages
= 0;
2069 stock
->cached
= NULL
;
2073 * This must be called under preempt disabled or must be called by
2074 * a thread which is pinned to local cpu.
2076 static void drain_local_stock(struct work_struct
*dummy
)
2078 struct memcg_stock_pcp
*stock
= &__get_cpu_var(memcg_stock
);
2080 clear_bit(FLUSHING_CACHED_CHARGE
, &stock
->flags
);
2084 * Cache charges(val) which is from res_counter, to local per_cpu area.
2085 * This will be consumed by consume_stock() function, later.
2087 static void refill_stock(struct mem_cgroup
*memcg
, unsigned int nr_pages
)
2089 struct memcg_stock_pcp
*stock
= &get_cpu_var(memcg_stock
);
2091 if (stock
->cached
!= memcg
) { /* reset if necessary */
2093 stock
->cached
= memcg
;
2095 stock
->nr_pages
+= nr_pages
;
2096 put_cpu_var(memcg_stock
);
2100 * Drains all per-CPU charge caches for given root_memcg resp. subtree
2101 * of the hierarchy under it. sync flag says whether we should block
2102 * until the work is done.
2104 static void drain_all_stock(struct mem_cgroup
*root_memcg
, bool sync
)
2108 /* Notify other cpus that system-wide "drain" is running */
2111 for_each_online_cpu(cpu
) {
2112 struct memcg_stock_pcp
*stock
= &per_cpu(memcg_stock
, cpu
);
2113 struct mem_cgroup
*memcg
;
2115 memcg
= stock
->cached
;
2116 if (!memcg
|| !stock
->nr_pages
)
2118 if (!mem_cgroup_same_or_subtree(root_memcg
, memcg
))
2120 if (!test_and_set_bit(FLUSHING_CACHED_CHARGE
, &stock
->flags
)) {
2122 drain_local_stock(&stock
->work
);
2124 schedule_work_on(cpu
, &stock
->work
);
2132 for_each_online_cpu(cpu
) {
2133 struct memcg_stock_pcp
*stock
= &per_cpu(memcg_stock
, cpu
);
2134 if (test_bit(FLUSHING_CACHED_CHARGE
, &stock
->flags
))
2135 flush_work(&stock
->work
);
2142 * Tries to drain stocked charges in other cpus. This function is asynchronous
2143 * and just put a work per cpu for draining localy on each cpu. Caller can
2144 * expects some charges will be back to res_counter later but cannot wait for
2147 static void drain_all_stock_async(struct mem_cgroup
*root_memcg
)
2150 * If someone calls draining, avoid adding more kworker runs.
2152 if (!mutex_trylock(&percpu_charge_mutex
))
2154 drain_all_stock(root_memcg
, false);
2155 mutex_unlock(&percpu_charge_mutex
);
2158 /* This is a synchronous drain interface. */
2159 static void drain_all_stock_sync(struct mem_cgroup
*root_memcg
)
2161 /* called when force_empty is called */
2162 mutex_lock(&percpu_charge_mutex
);
2163 drain_all_stock(root_memcg
, true);
2164 mutex_unlock(&percpu_charge_mutex
);
2168 * This function drains percpu counter value from DEAD cpu and
2169 * move it to local cpu. Note that this function can be preempted.
2171 static void mem_cgroup_drain_pcp_counter(struct mem_cgroup
*memcg
, int cpu
)
2175 spin_lock(&memcg
->pcp_counter_lock
);
2176 for (i
= 0; i
< MEM_CGROUP_STAT_NSTATS
; i
++) {
2177 long x
= per_cpu(memcg
->stat
->count
[i
], cpu
);
2179 per_cpu(memcg
->stat
->count
[i
], cpu
) = 0;
2180 memcg
->nocpu_base
.count
[i
] += x
;
2182 for (i
= 0; i
< MEM_CGROUP_EVENTS_NSTATS
; i
++) {
2183 unsigned long x
= per_cpu(memcg
->stat
->events
[i
], cpu
);
2185 per_cpu(memcg
->stat
->events
[i
], cpu
) = 0;
2186 memcg
->nocpu_base
.events
[i
] += x
;
2188 spin_unlock(&memcg
->pcp_counter_lock
);
2191 static int __cpuinit
memcg_cpu_hotplug_callback(struct notifier_block
*nb
,
2192 unsigned long action
,
2195 int cpu
= (unsigned long)hcpu
;
2196 struct memcg_stock_pcp
*stock
;
2197 struct mem_cgroup
*iter
;
2199 if (action
== CPU_ONLINE
)
2202 if (action
!= CPU_DEAD
&& action
!= CPU_DEAD_FROZEN
)
2205 for_each_mem_cgroup(iter
)
2206 mem_cgroup_drain_pcp_counter(iter
, cpu
);
2208 stock
= &per_cpu(memcg_stock
, cpu
);
2214 /* See __mem_cgroup_try_charge() for details */
2216 CHARGE_OK
, /* success */
2217 CHARGE_RETRY
, /* need to retry but retry is not bad */
2218 CHARGE_NOMEM
, /* we can't do more. return -ENOMEM */
2219 CHARGE_WOULDBLOCK
, /* GFP_WAIT wasn't set and no enough res. */
2220 CHARGE_OOM_DIE
, /* the current is killed because of OOM */
2223 static int mem_cgroup_do_charge(struct mem_cgroup
*memcg
, gfp_t gfp_mask
,
2224 unsigned int nr_pages
, bool oom_check
)
2226 unsigned long csize
= nr_pages
* PAGE_SIZE
;
2227 struct mem_cgroup
*mem_over_limit
;
2228 struct res_counter
*fail_res
;
2229 unsigned long flags
= 0;
2232 ret
= res_counter_charge(&memcg
->res
, csize
, &fail_res
);
2235 if (!do_swap_account
)
2237 ret
= res_counter_charge(&memcg
->memsw
, csize
, &fail_res
);
2241 res_counter_uncharge(&memcg
->res
, csize
);
2242 mem_over_limit
= mem_cgroup_from_res_counter(fail_res
, memsw
);
2243 flags
|= MEM_CGROUP_RECLAIM_NOSWAP
;
2245 mem_over_limit
= mem_cgroup_from_res_counter(fail_res
, res
);
2247 * nr_pages can be either a huge page (HPAGE_PMD_NR), a batch
2248 * of regular pages (CHARGE_BATCH), or a single regular page (1).
2250 * Never reclaim on behalf of optional batching, retry with a
2251 * single page instead.
2253 if (nr_pages
== CHARGE_BATCH
)
2254 return CHARGE_RETRY
;
2256 if (!(gfp_mask
& __GFP_WAIT
))
2257 return CHARGE_WOULDBLOCK
;
2259 ret
= mem_cgroup_reclaim(mem_over_limit
, gfp_mask
, flags
);
2260 if (mem_cgroup_margin(mem_over_limit
) >= nr_pages
)
2261 return CHARGE_RETRY
;
2263 * Even though the limit is exceeded at this point, reclaim
2264 * may have been able to free some pages. Retry the charge
2265 * before killing the task.
2267 * Only for regular pages, though: huge pages are rather
2268 * unlikely to succeed so close to the limit, and we fall back
2269 * to regular pages anyway in case of failure.
2271 if (nr_pages
== 1 && ret
)
2272 return CHARGE_RETRY
;
2275 * At task move, charge accounts can be doubly counted. So, it's
2276 * better to wait until the end of task_move if something is going on.
2278 if (mem_cgroup_wait_acct_move(mem_over_limit
))
2279 return CHARGE_RETRY
;
2281 /* If we don't need to call oom-killer at el, return immediately */
2283 return CHARGE_NOMEM
;
2285 if (!mem_cgroup_handle_oom(mem_over_limit
, gfp_mask
, get_order(csize
)))
2286 return CHARGE_OOM_DIE
;
2288 return CHARGE_RETRY
;
2292 * __mem_cgroup_try_charge() does
2293 * 1. detect memcg to be charged against from passed *mm and *ptr,
2294 * 2. update res_counter
2295 * 3. call memory reclaim if necessary.
2297 * In some special case, if the task is fatal, fatal_signal_pending() or
2298 * has TIF_MEMDIE, this function returns -EINTR while writing root_mem_cgroup
2299 * to *ptr. There are two reasons for this. 1: fatal threads should quit as soon
2300 * as possible without any hazards. 2: all pages should have a valid
2301 * pc->mem_cgroup. If mm is NULL and the caller doesn't pass a valid memcg
2302 * pointer, that is treated as a charge to root_mem_cgroup.
2304 * So __mem_cgroup_try_charge() will return
2305 * 0 ... on success, filling *ptr with a valid memcg pointer.
2306 * -ENOMEM ... charge failure because of resource limits.
2307 * -EINTR ... if thread is fatal. *ptr is filled with root_mem_cgroup.
2309 * Unlike the exported interface, an "oom" parameter is added. if oom==true,
2310 * the oom-killer can be invoked.
2312 static int __mem_cgroup_try_charge(struct mm_struct
*mm
,
2314 unsigned int nr_pages
,
2315 struct mem_cgroup
**ptr
,
2318 unsigned int batch
= max(CHARGE_BATCH
, nr_pages
);
2319 int nr_oom_retries
= MEM_CGROUP_RECLAIM_RETRIES
;
2320 struct mem_cgroup
*memcg
= NULL
;
2324 * Unlike gloval-vm's OOM-kill, we're not in memory shortage
2325 * in system level. So, allow to go ahead dying process in addition to
2328 if (unlikely(test_thread_flag(TIF_MEMDIE
)
2329 || fatal_signal_pending(current
)))
2333 * We always charge the cgroup the mm_struct belongs to.
2334 * The mm_struct's mem_cgroup changes on task migration if the
2335 * thread group leader migrates. It's possible that mm is not
2336 * set, if so charge the root memcg (happens for pagecache usage).
2339 *ptr
= root_mem_cgroup
;
2341 if (*ptr
) { /* css should be a valid one */
2343 VM_BUG_ON(css_is_removed(&memcg
->css
));
2344 if (mem_cgroup_is_root(memcg
))
2346 if (nr_pages
== 1 && consume_stock(memcg
))
2348 css_get(&memcg
->css
);
2350 struct task_struct
*p
;
2353 p
= rcu_dereference(mm
->owner
);
2355 * Because we don't have task_lock(), "p" can exit.
2356 * In that case, "memcg" can point to root or p can be NULL with
2357 * race with swapoff. Then, we have small risk of mis-accouning.
2358 * But such kind of mis-account by race always happens because
2359 * we don't have cgroup_mutex(). It's overkill and we allo that
2361 * (*) swapoff at el will charge against mm-struct not against
2362 * task-struct. So, mm->owner can be NULL.
2364 memcg
= mem_cgroup_from_task(p
);
2366 memcg
= root_mem_cgroup
;
2367 if (mem_cgroup_is_root(memcg
)) {
2371 if (nr_pages
== 1 && consume_stock(memcg
)) {
2373 * It seems dagerous to access memcg without css_get().
2374 * But considering how consume_stok works, it's not
2375 * necessary. If consume_stock success, some charges
2376 * from this memcg are cached on this cpu. So, we
2377 * don't need to call css_get()/css_tryget() before
2378 * calling consume_stock().
2383 /* after here, we may be blocked. we need to get refcnt */
2384 if (!css_tryget(&memcg
->css
)) {
2394 /* If killed, bypass charge */
2395 if (fatal_signal_pending(current
)) {
2396 css_put(&memcg
->css
);
2401 if (oom
&& !nr_oom_retries
) {
2403 nr_oom_retries
= MEM_CGROUP_RECLAIM_RETRIES
;
2406 ret
= mem_cgroup_do_charge(memcg
, gfp_mask
, batch
, oom_check
);
2410 case CHARGE_RETRY
: /* not in OOM situation but retry */
2412 css_put(&memcg
->css
);
2415 case CHARGE_WOULDBLOCK
: /* !__GFP_WAIT */
2416 css_put(&memcg
->css
);
2418 case CHARGE_NOMEM
: /* OOM routine works */
2420 css_put(&memcg
->css
);
2423 /* If oom, we never return -ENOMEM */
2426 case CHARGE_OOM_DIE
: /* Killed by OOM Killer */
2427 css_put(&memcg
->css
);
2430 } while (ret
!= CHARGE_OK
);
2432 if (batch
> nr_pages
)
2433 refill_stock(memcg
, batch
- nr_pages
);
2434 css_put(&memcg
->css
);
2442 *ptr
= root_mem_cgroup
;
2447 * Somemtimes we have to undo a charge we got by try_charge().
2448 * This function is for that and do uncharge, put css's refcnt.
2449 * gotten by try_charge().
2451 static void __mem_cgroup_cancel_charge(struct mem_cgroup
*memcg
,
2452 unsigned int nr_pages
)
2454 if (!mem_cgroup_is_root(memcg
)) {
2455 unsigned long bytes
= nr_pages
* PAGE_SIZE
;
2457 res_counter_uncharge(&memcg
->res
, bytes
);
2458 if (do_swap_account
)
2459 res_counter_uncharge(&memcg
->memsw
, bytes
);
2464 * Cancel chrages in this cgroup....doesn't propagate to parent cgroup.
2465 * This is useful when moving usage to parent cgroup.
2467 static void __mem_cgroup_cancel_local_charge(struct mem_cgroup
*memcg
,
2468 unsigned int nr_pages
)
2470 unsigned long bytes
= nr_pages
* PAGE_SIZE
;
2472 if (mem_cgroup_is_root(memcg
))
2475 res_counter_uncharge_until(&memcg
->res
, memcg
->res
.parent
, bytes
);
2476 if (do_swap_account
)
2477 res_counter_uncharge_until(&memcg
->memsw
,
2478 memcg
->memsw
.parent
, bytes
);
2482 * A helper function to get mem_cgroup from ID. must be called under
2483 * rcu_read_lock(). The caller must check css_is_removed() or some if
2484 * it's concern. (dropping refcnt from swap can be called against removed
2487 static struct mem_cgroup
*mem_cgroup_lookup(unsigned short id
)
2489 struct cgroup_subsys_state
*css
;
2491 /* ID 0 is unused ID */
2494 css
= css_lookup(&mem_cgroup_subsys
, id
);
2497 return container_of(css
, struct mem_cgroup
, css
);
2500 struct mem_cgroup
*try_get_mem_cgroup_from_page(struct page
*page
)
2502 struct mem_cgroup
*memcg
= NULL
;
2503 struct page_cgroup
*pc
;
2507 VM_BUG_ON(!PageLocked(page
));
2509 pc
= lookup_page_cgroup(page
);
2510 lock_page_cgroup(pc
);
2511 if (PageCgroupUsed(pc
)) {
2512 memcg
= pc
->mem_cgroup
;
2513 if (memcg
&& !css_tryget(&memcg
->css
))
2515 } else if (PageSwapCache(page
)) {
2516 ent
.val
= page_private(page
);
2517 id
= lookup_swap_cgroup_id(ent
);
2519 memcg
= mem_cgroup_lookup(id
);
2520 if (memcg
&& !css_tryget(&memcg
->css
))
2524 unlock_page_cgroup(pc
);
2528 static void __mem_cgroup_commit_charge(struct mem_cgroup
*memcg
,
2530 unsigned int nr_pages
,
2531 enum charge_type ctype
,
2534 struct page_cgroup
*pc
= lookup_page_cgroup(page
);
2535 struct zone
*uninitialized_var(zone
);
2536 struct lruvec
*lruvec
;
2537 bool was_on_lru
= false;
2540 lock_page_cgroup(pc
);
2541 VM_BUG_ON(PageCgroupUsed(pc
));
2543 * we don't need page_cgroup_lock about tail pages, becase they are not
2544 * accessed by any other context at this point.
2548 * In some cases, SwapCache and FUSE(splice_buf->radixtree), the page
2549 * may already be on some other mem_cgroup's LRU. Take care of it.
2552 zone
= page_zone(page
);
2553 spin_lock_irq(&zone
->lru_lock
);
2554 if (PageLRU(page
)) {
2555 lruvec
= mem_cgroup_zone_lruvec(zone
, pc
->mem_cgroup
);
2557 del_page_from_lru_list(page
, lruvec
, page_lru(page
));
2562 pc
->mem_cgroup
= memcg
;
2564 * We access a page_cgroup asynchronously without lock_page_cgroup().
2565 * Especially when a page_cgroup is taken from a page, pc->mem_cgroup
2566 * is accessed after testing USED bit. To make pc->mem_cgroup visible
2567 * before USED bit, we need memory barrier here.
2568 * See mem_cgroup_add_lru_list(), etc.
2571 SetPageCgroupUsed(pc
);
2575 lruvec
= mem_cgroup_zone_lruvec(zone
, pc
->mem_cgroup
);
2576 VM_BUG_ON(PageLRU(page
));
2578 add_page_to_lru_list(page
, lruvec
, page_lru(page
));
2580 spin_unlock_irq(&zone
->lru_lock
);
2583 if (ctype
== MEM_CGROUP_CHARGE_TYPE_ANON
)
2588 mem_cgroup_charge_statistics(memcg
, anon
, nr_pages
);
2589 unlock_page_cgroup(pc
);
2592 * "charge_statistics" updated event counter. Then, check it.
2593 * Insert ancestor (and ancestor's ancestors), to softlimit RB-tree.
2594 * if they exceeds softlimit.
2596 memcg_check_events(memcg
, page
);
2599 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
2601 #define PCGF_NOCOPY_AT_SPLIT (1 << PCG_LOCK | 1 << PCG_MIGRATION)
2603 * Because tail pages are not marked as "used", set it. We're under
2604 * zone->lru_lock, 'splitting on pmd' and compound_lock.
2605 * charge/uncharge will be never happen and move_account() is done under
2606 * compound_lock(), so we don't have to take care of races.
2608 void mem_cgroup_split_huge_fixup(struct page
*head
)
2610 struct page_cgroup
*head_pc
= lookup_page_cgroup(head
);
2611 struct page_cgroup
*pc
;
2614 if (mem_cgroup_disabled())
2616 for (i
= 1; i
< HPAGE_PMD_NR
; i
++) {
2618 pc
->mem_cgroup
= head_pc
->mem_cgroup
;
2619 smp_wmb();/* see __commit_charge() */
2620 pc
->flags
= head_pc
->flags
& ~PCGF_NOCOPY_AT_SPLIT
;
2623 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
2626 * mem_cgroup_move_account - move account of the page
2628 * @nr_pages: number of regular pages (>1 for huge pages)
2629 * @pc: page_cgroup of the page.
2630 * @from: mem_cgroup which the page is moved from.
2631 * @to: mem_cgroup which the page is moved to. @from != @to.
2633 * The caller must confirm following.
2634 * - page is not on LRU (isolate_page() is useful.)
2635 * - compound_lock is held when nr_pages > 1
2637 * This function doesn't do "charge" to new cgroup and doesn't do "uncharge"
2640 static int mem_cgroup_move_account(struct page
*page
,
2641 unsigned int nr_pages
,
2642 struct page_cgroup
*pc
,
2643 struct mem_cgroup
*from
,
2644 struct mem_cgroup
*to
)
2646 unsigned long flags
;
2648 bool anon
= PageAnon(page
);
2650 VM_BUG_ON(from
== to
);
2651 VM_BUG_ON(PageLRU(page
));
2653 * The page is isolated from LRU. So, collapse function
2654 * will not handle this page. But page splitting can happen.
2655 * Do this check under compound_page_lock(). The caller should
2659 if (nr_pages
> 1 && !PageTransHuge(page
))
2662 lock_page_cgroup(pc
);
2665 if (!PageCgroupUsed(pc
) || pc
->mem_cgroup
!= from
)
2668 move_lock_mem_cgroup(from
, &flags
);
2670 if (!anon
&& page_mapped(page
)) {
2671 /* Update mapped_file data for mem_cgroup */
2673 __this_cpu_dec(from
->stat
->count
[MEM_CGROUP_STAT_FILE_MAPPED
]);
2674 __this_cpu_inc(to
->stat
->count
[MEM_CGROUP_STAT_FILE_MAPPED
]);
2677 mem_cgroup_charge_statistics(from
, anon
, -nr_pages
);
2679 /* caller should have done css_get */
2680 pc
->mem_cgroup
= to
;
2681 mem_cgroup_charge_statistics(to
, anon
, nr_pages
);
2683 * We charges against "to" which may not have any tasks. Then, "to"
2684 * can be under rmdir(). But in current implementation, caller of
2685 * this function is just force_empty() and move charge, so it's
2686 * guaranteed that "to" is never removed. So, we don't check rmdir
2689 move_unlock_mem_cgroup(from
, &flags
);
2692 unlock_page_cgroup(pc
);
2696 memcg_check_events(to
, page
);
2697 memcg_check_events(from
, page
);
2703 * move charges to its parent.
2706 static int mem_cgroup_move_parent(struct page
*page
,
2707 struct page_cgroup
*pc
,
2708 struct mem_cgroup
*child
)
2710 struct mem_cgroup
*parent
;
2711 unsigned int nr_pages
;
2712 unsigned long uninitialized_var(flags
);
2716 if (mem_cgroup_is_root(child
))
2720 if (!get_page_unless_zero(page
))
2722 if (isolate_lru_page(page
))
2725 nr_pages
= hpage_nr_pages(page
);
2727 parent
= parent_mem_cgroup(child
);
2729 * If no parent, move charges to root cgroup.
2732 parent
= root_mem_cgroup
;
2735 flags
= compound_lock_irqsave(page
);
2737 ret
= mem_cgroup_move_account(page
, nr_pages
,
2740 __mem_cgroup_cancel_local_charge(child
, nr_pages
);
2743 compound_unlock_irqrestore(page
, flags
);
2744 putback_lru_page(page
);
2752 * Charge the memory controller for page usage.
2754 * 0 if the charge was successful
2755 * < 0 if the cgroup is over its limit
2757 static int mem_cgroup_charge_common(struct page
*page
, struct mm_struct
*mm
,
2758 gfp_t gfp_mask
, enum charge_type ctype
)
2760 struct mem_cgroup
*memcg
= NULL
;
2761 unsigned int nr_pages
= 1;
2765 if (PageTransHuge(page
)) {
2766 nr_pages
<<= compound_order(page
);
2767 VM_BUG_ON(!PageTransHuge(page
));
2769 * Never OOM-kill a process for a huge page. The
2770 * fault handler will fall back to regular pages.
2775 ret
= __mem_cgroup_try_charge(mm
, gfp_mask
, nr_pages
, &memcg
, oom
);
2778 __mem_cgroup_commit_charge(memcg
, page
, nr_pages
, ctype
, false);
2782 int mem_cgroup_newpage_charge(struct page
*page
,
2783 struct mm_struct
*mm
, gfp_t gfp_mask
)
2785 if (mem_cgroup_disabled())
2787 VM_BUG_ON(page_mapped(page
));
2788 VM_BUG_ON(page
->mapping
&& !PageAnon(page
));
2790 return mem_cgroup_charge_common(page
, mm
, gfp_mask
,
2791 MEM_CGROUP_CHARGE_TYPE_ANON
);
2795 * While swap-in, try_charge -> commit or cancel, the page is locked.
2796 * And when try_charge() successfully returns, one refcnt to memcg without
2797 * struct page_cgroup is acquired. This refcnt will be consumed by
2798 * "commit()" or removed by "cancel()"
2800 static int __mem_cgroup_try_charge_swapin(struct mm_struct
*mm
,
2803 struct mem_cgroup
**memcgp
)
2805 struct mem_cgroup
*memcg
;
2806 struct page_cgroup
*pc
;
2809 pc
= lookup_page_cgroup(page
);
2811 * Every swap fault against a single page tries to charge the
2812 * page, bail as early as possible. shmem_unuse() encounters
2813 * already charged pages, too. The USED bit is protected by
2814 * the page lock, which serializes swap cache removal, which
2815 * in turn serializes uncharging.
2817 if (PageCgroupUsed(pc
))
2819 if (!do_swap_account
)
2822 * A racing thread's fault, or swapoff, may have already updated
2823 * the pte, and even removed page from swap cache: in those cases
2824 * do_swap_page()'s pte_same() test will fail; but there's also a
2825 * KSM case which does need to charge the page.
2827 if (!PageSwapCache(page
))
2829 memcg
= try_get_mem_cgroup_from_page(page
);
2833 ret
= __mem_cgroup_try_charge(NULL
, mask
, 1, memcgp
, true);
2834 css_put(&memcg
->css
);
2839 ret
= __mem_cgroup_try_charge(mm
, mask
, 1, memcgp
, true);
2845 int mem_cgroup_try_charge_swapin(struct mm_struct
*mm
, struct page
*page
,
2846 gfp_t gfp_mask
, struct mem_cgroup
**memcgp
)
2849 if (mem_cgroup_disabled())
2851 return __mem_cgroup_try_charge_swapin(mm
, page
, gfp_mask
, memcgp
);
2854 void mem_cgroup_cancel_charge_swapin(struct mem_cgroup
*memcg
)
2856 if (mem_cgroup_disabled())
2860 __mem_cgroup_cancel_charge(memcg
, 1);
2864 __mem_cgroup_commit_charge_swapin(struct page
*page
, struct mem_cgroup
*memcg
,
2865 enum charge_type ctype
)
2867 if (mem_cgroup_disabled())
2871 cgroup_exclude_rmdir(&memcg
->css
);
2873 __mem_cgroup_commit_charge(memcg
, page
, 1, ctype
, true);
2875 * Now swap is on-memory. This means this page may be
2876 * counted both as mem and swap....double count.
2877 * Fix it by uncharging from memsw. Basically, this SwapCache is stable
2878 * under lock_page(). But in do_swap_page()::memory.c, reuse_swap_page()
2879 * may call delete_from_swap_cache() before reach here.
2881 if (do_swap_account
&& PageSwapCache(page
)) {
2882 swp_entry_t ent
= {.val
= page_private(page
)};
2883 mem_cgroup_uncharge_swap(ent
);
2886 * At swapin, we may charge account against cgroup which has no tasks.
2887 * So, rmdir()->pre_destroy() can be called while we do this charge.
2888 * In that case, we need to call pre_destroy() again. check it here.
2890 cgroup_release_and_wakeup_rmdir(&memcg
->css
);
2893 void mem_cgroup_commit_charge_swapin(struct page
*page
,
2894 struct mem_cgroup
*memcg
)
2896 __mem_cgroup_commit_charge_swapin(page
, memcg
,
2897 MEM_CGROUP_CHARGE_TYPE_ANON
);
2900 int mem_cgroup_cache_charge(struct page
*page
, struct mm_struct
*mm
,
2903 struct mem_cgroup
*memcg
= NULL
;
2904 enum charge_type type
= MEM_CGROUP_CHARGE_TYPE_CACHE
;
2907 if (mem_cgroup_disabled())
2909 if (PageCompound(page
))
2912 if (!PageSwapCache(page
))
2913 ret
= mem_cgroup_charge_common(page
, mm
, gfp_mask
, type
);
2914 else { /* page is swapcache/shmem */
2915 ret
= __mem_cgroup_try_charge_swapin(mm
, page
,
2918 __mem_cgroup_commit_charge_swapin(page
, memcg
, type
);
2923 static void mem_cgroup_do_uncharge(struct mem_cgroup
*memcg
,
2924 unsigned int nr_pages
,
2925 const enum charge_type ctype
)
2927 struct memcg_batch_info
*batch
= NULL
;
2928 bool uncharge_memsw
= true;
2930 /* If swapout, usage of swap doesn't decrease */
2931 if (!do_swap_account
|| ctype
== MEM_CGROUP_CHARGE_TYPE_SWAPOUT
)
2932 uncharge_memsw
= false;
2934 batch
= ¤t
->memcg_batch
;
2936 * In usual, we do css_get() when we remember memcg pointer.
2937 * But in this case, we keep res->usage until end of a series of
2938 * uncharges. Then, it's ok to ignore memcg's refcnt.
2941 batch
->memcg
= memcg
;
2943 * do_batch > 0 when unmapping pages or inode invalidate/truncate.
2944 * In those cases, all pages freed continuously can be expected to be in
2945 * the same cgroup and we have chance to coalesce uncharges.
2946 * But we do uncharge one by one if this is killed by OOM(TIF_MEMDIE)
2947 * because we want to do uncharge as soon as possible.
2950 if (!batch
->do_batch
|| test_thread_flag(TIF_MEMDIE
))
2951 goto direct_uncharge
;
2954 goto direct_uncharge
;
2957 * In typical case, batch->memcg == mem. This means we can
2958 * merge a series of uncharges to an uncharge of res_counter.
2959 * If not, we uncharge res_counter ony by one.
2961 if (batch
->memcg
!= memcg
)
2962 goto direct_uncharge
;
2963 /* remember freed charge and uncharge it later */
2966 batch
->memsw_nr_pages
++;
2969 res_counter_uncharge(&memcg
->res
, nr_pages
* PAGE_SIZE
);
2971 res_counter_uncharge(&memcg
->memsw
, nr_pages
* PAGE_SIZE
);
2972 if (unlikely(batch
->memcg
!= memcg
))
2973 memcg_oom_recover(memcg
);
2977 * uncharge if !page_mapped(page)
2979 static struct mem_cgroup
*
2980 __mem_cgroup_uncharge_common(struct page
*page
, enum charge_type ctype
,
2983 struct mem_cgroup
*memcg
= NULL
;
2984 unsigned int nr_pages
= 1;
2985 struct page_cgroup
*pc
;
2988 if (mem_cgroup_disabled())
2991 VM_BUG_ON(PageSwapCache(page
));
2993 if (PageTransHuge(page
)) {
2994 nr_pages
<<= compound_order(page
);
2995 VM_BUG_ON(!PageTransHuge(page
));
2998 * Check if our page_cgroup is valid
3000 pc
= lookup_page_cgroup(page
);
3001 if (unlikely(!PageCgroupUsed(pc
)))
3004 lock_page_cgroup(pc
);
3006 memcg
= pc
->mem_cgroup
;
3008 if (!PageCgroupUsed(pc
))
3011 anon
= PageAnon(page
);
3014 case MEM_CGROUP_CHARGE_TYPE_ANON
:
3016 * Generally PageAnon tells if it's the anon statistics to be
3017 * updated; but sometimes e.g. mem_cgroup_uncharge_page() is
3018 * used before page reached the stage of being marked PageAnon.
3022 case MEM_CGROUP_CHARGE_TYPE_DROP
:
3023 /* See mem_cgroup_prepare_migration() */
3024 if (page_mapped(page
))
3027 * Pages under migration may not be uncharged. But
3028 * end_migration() /must/ be the one uncharging the
3029 * unused post-migration page and so it has to call
3030 * here with the migration bit still set. See the
3031 * res_counter handling below.
3033 if (!end_migration
&& PageCgroupMigration(pc
))
3036 case MEM_CGROUP_CHARGE_TYPE_SWAPOUT
:
3037 if (!PageAnon(page
)) { /* Shared memory */
3038 if (page
->mapping
&& !page_is_file_cache(page
))
3040 } else if (page_mapped(page
)) /* Anon */
3047 mem_cgroup_charge_statistics(memcg
, anon
, -nr_pages
);
3049 ClearPageCgroupUsed(pc
);
3051 * pc->mem_cgroup is not cleared here. It will be accessed when it's
3052 * freed from LRU. This is safe because uncharged page is expected not
3053 * to be reused (freed soon). Exception is SwapCache, it's handled by
3054 * special functions.
3057 unlock_page_cgroup(pc
);
3059 * even after unlock, we have memcg->res.usage here and this memcg
3060 * will never be freed.
3062 memcg_check_events(memcg
, page
);
3063 if (do_swap_account
&& ctype
== MEM_CGROUP_CHARGE_TYPE_SWAPOUT
) {
3064 mem_cgroup_swap_statistics(memcg
, true);
3065 mem_cgroup_get(memcg
);
3068 * Migration does not charge the res_counter for the
3069 * replacement page, so leave it alone when phasing out the
3070 * page that is unused after the migration.
3072 if (!end_migration
&& !mem_cgroup_is_root(memcg
))
3073 mem_cgroup_do_uncharge(memcg
, nr_pages
, ctype
);
3078 unlock_page_cgroup(pc
);
3082 void mem_cgroup_uncharge_page(struct page
*page
)
3085 if (page_mapped(page
))
3087 VM_BUG_ON(page
->mapping
&& !PageAnon(page
));
3088 if (PageSwapCache(page
))
3090 __mem_cgroup_uncharge_common(page
, MEM_CGROUP_CHARGE_TYPE_ANON
, false);
3093 void mem_cgroup_uncharge_cache_page(struct page
*page
)
3095 VM_BUG_ON(page_mapped(page
));
3096 VM_BUG_ON(page
->mapping
);
3097 __mem_cgroup_uncharge_common(page
, MEM_CGROUP_CHARGE_TYPE_CACHE
, false);
3101 * Batch_start/batch_end is called in unmap_page_range/invlidate/trucate.
3102 * In that cases, pages are freed continuously and we can expect pages
3103 * are in the same memcg. All these calls itself limits the number of
3104 * pages freed at once, then uncharge_start/end() is called properly.
3105 * This may be called prural(2) times in a context,
3108 void mem_cgroup_uncharge_start(void)
3110 current
->memcg_batch
.do_batch
++;
3111 /* We can do nest. */
3112 if (current
->memcg_batch
.do_batch
== 1) {
3113 current
->memcg_batch
.memcg
= NULL
;
3114 current
->memcg_batch
.nr_pages
= 0;
3115 current
->memcg_batch
.memsw_nr_pages
= 0;
3119 void mem_cgroup_uncharge_end(void)
3121 struct memcg_batch_info
*batch
= ¤t
->memcg_batch
;
3123 if (!batch
->do_batch
)
3127 if (batch
->do_batch
) /* If stacked, do nothing. */
3133 * This "batch->memcg" is valid without any css_get/put etc...
3134 * bacause we hide charges behind us.
3136 if (batch
->nr_pages
)
3137 res_counter_uncharge(&batch
->memcg
->res
,
3138 batch
->nr_pages
* PAGE_SIZE
);
3139 if (batch
->memsw_nr_pages
)
3140 res_counter_uncharge(&batch
->memcg
->memsw
,
3141 batch
->memsw_nr_pages
* PAGE_SIZE
);
3142 memcg_oom_recover(batch
->memcg
);
3143 /* forget this pointer (for sanity check) */
3144 batch
->memcg
= NULL
;
3149 * called after __delete_from_swap_cache() and drop "page" account.
3150 * memcg information is recorded to swap_cgroup of "ent"
3153 mem_cgroup_uncharge_swapcache(struct page
*page
, swp_entry_t ent
, bool swapout
)
3155 struct mem_cgroup
*memcg
;
3156 int ctype
= MEM_CGROUP_CHARGE_TYPE_SWAPOUT
;
3158 if (!swapout
) /* this was a swap cache but the swap is unused ! */
3159 ctype
= MEM_CGROUP_CHARGE_TYPE_DROP
;
3161 memcg
= __mem_cgroup_uncharge_common(page
, ctype
, false);
3164 * record memcg information, if swapout && memcg != NULL,
3165 * mem_cgroup_get() was called in uncharge().
3167 if (do_swap_account
&& swapout
&& memcg
)
3168 swap_cgroup_record(ent
, css_id(&memcg
->css
));
3172 #ifdef CONFIG_MEMCG_SWAP
3174 * called from swap_entry_free(). remove record in swap_cgroup and
3175 * uncharge "memsw" account.
3177 void mem_cgroup_uncharge_swap(swp_entry_t ent
)
3179 struct mem_cgroup
*memcg
;
3182 if (!do_swap_account
)
3185 id
= swap_cgroup_record(ent
, 0);
3187 memcg
= mem_cgroup_lookup(id
);
3190 * We uncharge this because swap is freed.
3191 * This memcg can be obsolete one. We avoid calling css_tryget
3193 if (!mem_cgroup_is_root(memcg
))
3194 res_counter_uncharge(&memcg
->memsw
, PAGE_SIZE
);
3195 mem_cgroup_swap_statistics(memcg
, false);
3196 mem_cgroup_put(memcg
);
3202 * mem_cgroup_move_swap_account - move swap charge and swap_cgroup's record.
3203 * @entry: swap entry to be moved
3204 * @from: mem_cgroup which the entry is moved from
3205 * @to: mem_cgroup which the entry is moved to
3207 * It succeeds only when the swap_cgroup's record for this entry is the same
3208 * as the mem_cgroup's id of @from.
3210 * Returns 0 on success, -EINVAL on failure.
3212 * The caller must have charged to @to, IOW, called res_counter_charge() about
3213 * both res and memsw, and called css_get().
3215 static int mem_cgroup_move_swap_account(swp_entry_t entry
,
3216 struct mem_cgroup
*from
, struct mem_cgroup
*to
)
3218 unsigned short old_id
, new_id
;
3220 old_id
= css_id(&from
->css
);
3221 new_id
= css_id(&to
->css
);
3223 if (swap_cgroup_cmpxchg(entry
, old_id
, new_id
) == old_id
) {
3224 mem_cgroup_swap_statistics(from
, false);
3225 mem_cgroup_swap_statistics(to
, true);
3227 * This function is only called from task migration context now.
3228 * It postpones res_counter and refcount handling till the end
3229 * of task migration(mem_cgroup_clear_mc()) for performance
3230 * improvement. But we cannot postpone mem_cgroup_get(to)
3231 * because if the process that has been moved to @to does
3232 * swap-in, the refcount of @to might be decreased to 0.
3240 static inline int mem_cgroup_move_swap_account(swp_entry_t entry
,
3241 struct mem_cgroup
*from
, struct mem_cgroup
*to
)
3248 * Before starting migration, account PAGE_SIZE to mem_cgroup that the old
3251 void mem_cgroup_prepare_migration(struct page
*page
, struct page
*newpage
,
3252 struct mem_cgroup
**memcgp
)
3254 struct mem_cgroup
*memcg
= NULL
;
3255 struct page_cgroup
*pc
;
3256 enum charge_type ctype
;
3260 VM_BUG_ON(PageTransHuge(page
));
3261 if (mem_cgroup_disabled())
3264 pc
= lookup_page_cgroup(page
);
3265 lock_page_cgroup(pc
);
3266 if (PageCgroupUsed(pc
)) {
3267 memcg
= pc
->mem_cgroup
;
3268 css_get(&memcg
->css
);
3270 * At migrating an anonymous page, its mapcount goes down
3271 * to 0 and uncharge() will be called. But, even if it's fully
3272 * unmapped, migration may fail and this page has to be
3273 * charged again. We set MIGRATION flag here and delay uncharge
3274 * until end_migration() is called
3276 * Corner Case Thinking
3278 * When the old page was mapped as Anon and it's unmap-and-freed
3279 * while migration was ongoing.
3280 * If unmap finds the old page, uncharge() of it will be delayed
3281 * until end_migration(). If unmap finds a new page, it's
3282 * uncharged when it make mapcount to be 1->0. If unmap code
3283 * finds swap_migration_entry, the new page will not be mapped
3284 * and end_migration() will find it(mapcount==0).
3287 * When the old page was mapped but migraion fails, the kernel
3288 * remaps it. A charge for it is kept by MIGRATION flag even
3289 * if mapcount goes down to 0. We can do remap successfully
3290 * without charging it again.
3293 * The "old" page is under lock_page() until the end of
3294 * migration, so, the old page itself will not be swapped-out.
3295 * If the new page is swapped out before end_migraton, our
3296 * hook to usual swap-out path will catch the event.
3299 SetPageCgroupMigration(pc
);
3301 unlock_page_cgroup(pc
);
3303 * If the page is not charged at this point,
3311 * We charge new page before it's used/mapped. So, even if unlock_page()
3312 * is called before end_migration, we can catch all events on this new
3313 * page. In the case new page is migrated but not remapped, new page's
3314 * mapcount will be finally 0 and we call uncharge in end_migration().
3317 ctype
= MEM_CGROUP_CHARGE_TYPE_ANON
;
3319 ctype
= MEM_CGROUP_CHARGE_TYPE_CACHE
;
3321 * The page is committed to the memcg, but it's not actually
3322 * charged to the res_counter since we plan on replacing the
3323 * old one and only one page is going to be left afterwards.
3325 __mem_cgroup_commit_charge(memcg
, newpage
, 1, ctype
, false);
3328 /* remove redundant charge if migration failed*/
3329 void mem_cgroup_end_migration(struct mem_cgroup
*memcg
,
3330 struct page
*oldpage
, struct page
*newpage
, bool migration_ok
)
3332 struct page
*used
, *unused
;
3333 struct page_cgroup
*pc
;
3338 /* blocks rmdir() */
3339 cgroup_exclude_rmdir(&memcg
->css
);
3340 if (!migration_ok
) {
3347 anon
= PageAnon(used
);
3348 __mem_cgroup_uncharge_common(unused
,
3349 anon
? MEM_CGROUP_CHARGE_TYPE_ANON
3350 : MEM_CGROUP_CHARGE_TYPE_CACHE
,
3352 css_put(&memcg
->css
);
3354 * We disallowed uncharge of pages under migration because mapcount
3355 * of the page goes down to zero, temporarly.
3356 * Clear the flag and check the page should be charged.
3358 pc
= lookup_page_cgroup(oldpage
);
3359 lock_page_cgroup(pc
);
3360 ClearPageCgroupMigration(pc
);
3361 unlock_page_cgroup(pc
);
3364 * If a page is a file cache, radix-tree replacement is very atomic
3365 * and we can skip this check. When it was an Anon page, its mapcount
3366 * goes down to 0. But because we added MIGRATION flage, it's not
3367 * uncharged yet. There are several case but page->mapcount check
3368 * and USED bit check in mem_cgroup_uncharge_page() will do enough
3369 * check. (see prepare_charge() also)
3372 mem_cgroup_uncharge_page(used
);
3374 * At migration, we may charge account against cgroup which has no
3376 * So, rmdir()->pre_destroy() can be called while we do this charge.
3377 * In that case, we need to call pre_destroy() again. check it here.
3379 cgroup_release_and_wakeup_rmdir(&memcg
->css
);
3383 * At replace page cache, newpage is not under any memcg but it's on
3384 * LRU. So, this function doesn't touch res_counter but handles LRU
3385 * in correct way. Both pages are locked so we cannot race with uncharge.
3387 void mem_cgroup_replace_page_cache(struct page
*oldpage
,
3388 struct page
*newpage
)
3390 struct mem_cgroup
*memcg
= NULL
;
3391 struct page_cgroup
*pc
;
3392 enum charge_type type
= MEM_CGROUP_CHARGE_TYPE_CACHE
;
3394 if (mem_cgroup_disabled())
3397 pc
= lookup_page_cgroup(oldpage
);
3398 /* fix accounting on old pages */
3399 lock_page_cgroup(pc
);
3400 if (PageCgroupUsed(pc
)) {
3401 memcg
= pc
->mem_cgroup
;
3402 mem_cgroup_charge_statistics(memcg
, false, -1);
3403 ClearPageCgroupUsed(pc
);
3405 unlock_page_cgroup(pc
);
3408 * When called from shmem_replace_page(), in some cases the
3409 * oldpage has already been charged, and in some cases not.
3414 * Even if newpage->mapping was NULL before starting replacement,
3415 * the newpage may be on LRU(or pagevec for LRU) already. We lock
3416 * LRU while we overwrite pc->mem_cgroup.
3418 __mem_cgroup_commit_charge(memcg
, newpage
, 1, type
, true);
3421 #ifdef CONFIG_DEBUG_VM
3422 static struct page_cgroup
*lookup_page_cgroup_used(struct page
*page
)
3424 struct page_cgroup
*pc
;
3426 pc
= lookup_page_cgroup(page
);
3428 * Can be NULL while feeding pages into the page allocator for
3429 * the first time, i.e. during boot or memory hotplug;
3430 * or when mem_cgroup_disabled().
3432 if (likely(pc
) && PageCgroupUsed(pc
))
3437 bool mem_cgroup_bad_page_check(struct page
*page
)
3439 if (mem_cgroup_disabled())
3442 return lookup_page_cgroup_used(page
) != NULL
;
3445 void mem_cgroup_print_bad_page(struct page
*page
)
3447 struct page_cgroup
*pc
;
3449 pc
= lookup_page_cgroup_used(page
);
3451 printk(KERN_ALERT
"pc:%p pc->flags:%lx pc->mem_cgroup:%p\n",
3452 pc
, pc
->flags
, pc
->mem_cgroup
);
3457 static DEFINE_MUTEX(set_limit_mutex
);
3459 static int mem_cgroup_resize_limit(struct mem_cgroup
*memcg
,
3460 unsigned long long val
)
3463 u64 memswlimit
, memlimit
;
3465 int children
= mem_cgroup_count_children(memcg
);
3466 u64 curusage
, oldusage
;
3470 * For keeping hierarchical_reclaim simple, how long we should retry
3471 * is depends on callers. We set our retry-count to be function
3472 * of # of children which we should visit in this loop.
3474 retry_count
= MEM_CGROUP_RECLAIM_RETRIES
* children
;
3476 oldusage
= res_counter_read_u64(&memcg
->res
, RES_USAGE
);
3479 while (retry_count
) {
3480 if (signal_pending(current
)) {
3485 * Rather than hide all in some function, I do this in
3486 * open coded manner. You see what this really does.
3487 * We have to guarantee memcg->res.limit <= memcg->memsw.limit.
3489 mutex_lock(&set_limit_mutex
);
3490 memswlimit
= res_counter_read_u64(&memcg
->memsw
, RES_LIMIT
);
3491 if (memswlimit
< val
) {
3493 mutex_unlock(&set_limit_mutex
);
3497 memlimit
= res_counter_read_u64(&memcg
->res
, RES_LIMIT
);
3501 ret
= res_counter_set_limit(&memcg
->res
, val
);
3503 if (memswlimit
== val
)
3504 memcg
->memsw_is_minimum
= true;
3506 memcg
->memsw_is_minimum
= false;
3508 mutex_unlock(&set_limit_mutex
);
3513 mem_cgroup_reclaim(memcg
, GFP_KERNEL
,
3514 MEM_CGROUP_RECLAIM_SHRINK
);
3515 curusage
= res_counter_read_u64(&memcg
->res
, RES_USAGE
);
3516 /* Usage is reduced ? */
3517 if (curusage
>= oldusage
)
3520 oldusage
= curusage
;
3522 if (!ret
&& enlarge
)
3523 memcg_oom_recover(memcg
);
3528 static int mem_cgroup_resize_memsw_limit(struct mem_cgroup
*memcg
,
3529 unsigned long long val
)
3532 u64 memlimit
, memswlimit
, oldusage
, curusage
;
3533 int children
= mem_cgroup_count_children(memcg
);
3537 /* see mem_cgroup_resize_res_limit */
3538 retry_count
= children
* MEM_CGROUP_RECLAIM_RETRIES
;
3539 oldusage
= res_counter_read_u64(&memcg
->memsw
, RES_USAGE
);
3540 while (retry_count
) {
3541 if (signal_pending(current
)) {
3546 * Rather than hide all in some function, I do this in
3547 * open coded manner. You see what this really does.
3548 * We have to guarantee memcg->res.limit <= memcg->memsw.limit.
3550 mutex_lock(&set_limit_mutex
);
3551 memlimit
= res_counter_read_u64(&memcg
->res
, RES_LIMIT
);
3552 if (memlimit
> val
) {
3554 mutex_unlock(&set_limit_mutex
);
3557 memswlimit
= res_counter_read_u64(&memcg
->memsw
, RES_LIMIT
);
3558 if (memswlimit
< val
)
3560 ret
= res_counter_set_limit(&memcg
->memsw
, val
);
3562 if (memlimit
== val
)
3563 memcg
->memsw_is_minimum
= true;
3565 memcg
->memsw_is_minimum
= false;
3567 mutex_unlock(&set_limit_mutex
);
3572 mem_cgroup_reclaim(memcg
, GFP_KERNEL
,
3573 MEM_CGROUP_RECLAIM_NOSWAP
|
3574 MEM_CGROUP_RECLAIM_SHRINK
);
3575 curusage
= res_counter_read_u64(&memcg
->memsw
, RES_USAGE
);
3576 /* Usage is reduced ? */
3577 if (curusage
>= oldusage
)
3580 oldusage
= curusage
;
3582 if (!ret
&& enlarge
)
3583 memcg_oom_recover(memcg
);
3587 unsigned long mem_cgroup_soft_limit_reclaim(struct zone
*zone
, int order
,
3589 unsigned long *total_scanned
)
3591 unsigned long nr_reclaimed
= 0;
3592 struct mem_cgroup_per_zone
*mz
, *next_mz
= NULL
;
3593 unsigned long reclaimed
;
3595 struct mem_cgroup_tree_per_zone
*mctz
;
3596 unsigned long long excess
;
3597 unsigned long nr_scanned
;
3602 mctz
= soft_limit_tree_node_zone(zone_to_nid(zone
), zone_idx(zone
));
3604 * This loop can run a while, specially if mem_cgroup's continuously
3605 * keep exceeding their soft limit and putting the system under
3612 mz
= mem_cgroup_largest_soft_limit_node(mctz
);
3617 reclaimed
= mem_cgroup_soft_reclaim(mz
->memcg
, zone
,
3618 gfp_mask
, &nr_scanned
);
3619 nr_reclaimed
+= reclaimed
;
3620 *total_scanned
+= nr_scanned
;
3621 spin_lock(&mctz
->lock
);
3624 * If we failed to reclaim anything from this memory cgroup
3625 * it is time to move on to the next cgroup
3631 * Loop until we find yet another one.
3633 * By the time we get the soft_limit lock
3634 * again, someone might have aded the
3635 * group back on the RB tree. Iterate to
3636 * make sure we get a different mem.
3637 * mem_cgroup_largest_soft_limit_node returns
3638 * NULL if no other cgroup is present on
3642 __mem_cgroup_largest_soft_limit_node(mctz
);
3644 css_put(&next_mz
->memcg
->css
);
3645 else /* next_mz == NULL or other memcg */
3649 __mem_cgroup_remove_exceeded(mz
->memcg
, mz
, mctz
);
3650 excess
= res_counter_soft_limit_excess(&mz
->memcg
->res
);
3652 * One school of thought says that we should not add
3653 * back the node to the tree if reclaim returns 0.
3654 * But our reclaim could return 0, simply because due
3655 * to priority we are exposing a smaller subset of
3656 * memory to reclaim from. Consider this as a longer
3659 /* If excess == 0, no tree ops */
3660 __mem_cgroup_insert_exceeded(mz
->memcg
, mz
, mctz
, excess
);
3661 spin_unlock(&mctz
->lock
);
3662 css_put(&mz
->memcg
->css
);
3665 * Could not reclaim anything and there are no more
3666 * mem cgroups to try or we seem to be looping without
3667 * reclaiming anything.
3669 if (!nr_reclaimed
&&
3671 loop
> MEM_CGROUP_MAX_SOFT_LIMIT_RECLAIM_LOOPS
))
3673 } while (!nr_reclaimed
);
3675 css_put(&next_mz
->memcg
->css
);
3676 return nr_reclaimed
;
3680 * Traverse a specified page_cgroup list and try to drop them all. This doesn't
3681 * reclaim the pages page themselves - it just removes the page_cgroups.
3682 * Returns true if some page_cgroups were not freed, indicating that the caller
3683 * must retry this operation.
3685 static bool mem_cgroup_force_empty_list(struct mem_cgroup
*memcg
,
3686 int node
, int zid
, enum lru_list lru
)
3688 struct mem_cgroup_per_zone
*mz
;
3689 unsigned long flags
, loop
;
3690 struct list_head
*list
;
3694 zone
= &NODE_DATA(node
)->node_zones
[zid
];
3695 mz
= mem_cgroup_zoneinfo(memcg
, node
, zid
);
3696 list
= &mz
->lruvec
.lists
[lru
];
3698 loop
= mz
->lru_size
[lru
];
3699 /* give some margin against EBUSY etc...*/
3703 struct page_cgroup
*pc
;
3706 spin_lock_irqsave(&zone
->lru_lock
, flags
);
3707 if (list_empty(list
)) {
3708 spin_unlock_irqrestore(&zone
->lru_lock
, flags
);
3711 page
= list_entry(list
->prev
, struct page
, lru
);
3713 list_move(&page
->lru
, list
);
3715 spin_unlock_irqrestore(&zone
->lru_lock
, flags
);
3718 spin_unlock_irqrestore(&zone
->lru_lock
, flags
);
3720 pc
= lookup_page_cgroup(page
);
3722 if (mem_cgroup_move_parent(page
, pc
, memcg
)) {
3723 /* found lock contention or "pc" is obsolete. */
3729 return !list_empty(list
);
3733 * make mem_cgroup's charge to be 0 if there is no task.
3734 * This enables deleting this mem_cgroup.
3736 static int mem_cgroup_force_empty(struct mem_cgroup
*memcg
, bool free_all
)
3739 int node
, zid
, shrink
;
3740 int nr_retries
= MEM_CGROUP_RECLAIM_RETRIES
;
3741 struct cgroup
*cgrp
= memcg
->css
.cgroup
;
3743 css_get(&memcg
->css
);
3746 /* should free all ? */
3752 if (cgroup_task_count(cgrp
) || !list_empty(&cgrp
->children
))
3754 /* This is for making all *used* pages to be on LRU. */
3755 lru_add_drain_all();
3756 drain_all_stock_sync(memcg
);
3758 mem_cgroup_start_move(memcg
);
3759 for_each_node_state(node
, N_HIGH_MEMORY
) {
3760 for (zid
= 0; !ret
&& zid
< MAX_NR_ZONES
; zid
++) {
3763 ret
= mem_cgroup_force_empty_list(memcg
,
3772 mem_cgroup_end_move(memcg
);
3773 memcg_oom_recover(memcg
);
3775 /* "ret" should also be checked to ensure all lists are empty. */
3776 } while (res_counter_read_u64(&memcg
->res
, RES_USAGE
) > 0 || ret
);
3778 css_put(&memcg
->css
);
3782 /* returns EBUSY if there is a task or if we come here twice. */
3783 if (cgroup_task_count(cgrp
) || !list_empty(&cgrp
->children
) || shrink
) {
3787 /* we call try-to-free pages for make this cgroup empty */
3788 lru_add_drain_all();
3789 /* try to free all pages in this cgroup */
3791 while (nr_retries
&& res_counter_read_u64(&memcg
->res
, RES_USAGE
) > 0) {
3794 if (signal_pending(current
)) {
3798 progress
= try_to_free_mem_cgroup_pages(memcg
, GFP_KERNEL
,
3802 /* maybe some writeback is necessary */
3803 congestion_wait(BLK_RW_ASYNC
, HZ
/10);
3808 /* try move_account...there may be some *locked* pages. */
3812 static int mem_cgroup_force_empty_write(struct cgroup
*cont
, unsigned int event
)
3814 return mem_cgroup_force_empty(mem_cgroup_from_cont(cont
), true);
3818 static u64
mem_cgroup_hierarchy_read(struct cgroup
*cont
, struct cftype
*cft
)
3820 return mem_cgroup_from_cont(cont
)->use_hierarchy
;
3823 static int mem_cgroup_hierarchy_write(struct cgroup
*cont
, struct cftype
*cft
,
3827 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cont
);
3828 struct cgroup
*parent
= cont
->parent
;
3829 struct mem_cgroup
*parent_memcg
= NULL
;
3832 parent_memcg
= mem_cgroup_from_cont(parent
);
3836 if (memcg
->use_hierarchy
== val
)
3840 * If parent's use_hierarchy is set, we can't make any modifications
3841 * in the child subtrees. If it is unset, then the change can
3842 * occur, provided the current cgroup has no children.
3844 * For the root cgroup, parent_mem is NULL, we allow value to be
3845 * set if there are no children.
3847 if ((!parent_memcg
|| !parent_memcg
->use_hierarchy
) &&
3848 (val
== 1 || val
== 0)) {
3849 if (list_empty(&cont
->children
))
3850 memcg
->use_hierarchy
= val
;
3863 static unsigned long mem_cgroup_recursive_stat(struct mem_cgroup
*memcg
,
3864 enum mem_cgroup_stat_index idx
)
3866 struct mem_cgroup
*iter
;
3869 /* Per-cpu values can be negative, use a signed accumulator */
3870 for_each_mem_cgroup_tree(iter
, memcg
)
3871 val
+= mem_cgroup_read_stat(iter
, idx
);
3873 if (val
< 0) /* race ? */
3878 static inline u64
mem_cgroup_usage(struct mem_cgroup
*memcg
, bool swap
)
3882 if (!mem_cgroup_is_root(memcg
)) {
3884 return res_counter_read_u64(&memcg
->res
, RES_USAGE
);
3886 return res_counter_read_u64(&memcg
->memsw
, RES_USAGE
);
3889 val
= mem_cgroup_recursive_stat(memcg
, MEM_CGROUP_STAT_CACHE
);
3890 val
+= mem_cgroup_recursive_stat(memcg
, MEM_CGROUP_STAT_RSS
);
3893 val
+= mem_cgroup_recursive_stat(memcg
, MEM_CGROUP_STAT_SWAP
);
3895 return val
<< PAGE_SHIFT
;
3898 static ssize_t
mem_cgroup_read(struct cgroup
*cont
, struct cftype
*cft
,
3899 struct file
*file
, char __user
*buf
,
3900 size_t nbytes
, loff_t
*ppos
)
3902 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cont
);
3905 int type
, name
, len
;
3907 type
= MEMFILE_TYPE(cft
->private);
3908 name
= MEMFILE_ATTR(cft
->private);
3910 if (!do_swap_account
&& type
== _MEMSWAP
)
3915 if (name
== RES_USAGE
)
3916 val
= mem_cgroup_usage(memcg
, false);
3918 val
= res_counter_read_u64(&memcg
->res
, name
);
3921 if (name
== RES_USAGE
)
3922 val
= mem_cgroup_usage(memcg
, true);
3924 val
= res_counter_read_u64(&memcg
->memsw
, name
);
3930 len
= scnprintf(str
, sizeof(str
), "%llu\n", (unsigned long long)val
);
3931 return simple_read_from_buffer(buf
, nbytes
, ppos
, str
, len
);
3934 * The user of this function is...
3937 static int mem_cgroup_write(struct cgroup
*cont
, struct cftype
*cft
,
3940 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cont
);
3942 unsigned long long val
;
3945 type
= MEMFILE_TYPE(cft
->private);
3946 name
= MEMFILE_ATTR(cft
->private);
3948 if (!do_swap_account
&& type
== _MEMSWAP
)
3953 if (mem_cgroup_is_root(memcg
)) { /* Can't set limit on root */
3957 /* This function does all necessary parse...reuse it */
3958 ret
= res_counter_memparse_write_strategy(buffer
, &val
);
3962 ret
= mem_cgroup_resize_limit(memcg
, val
);
3964 ret
= mem_cgroup_resize_memsw_limit(memcg
, val
);
3966 case RES_SOFT_LIMIT
:
3967 ret
= res_counter_memparse_write_strategy(buffer
, &val
);
3971 * For memsw, soft limits are hard to implement in terms
3972 * of semantics, for now, we support soft limits for
3973 * control without swap
3976 ret
= res_counter_set_soft_limit(&memcg
->res
, val
);
3981 ret
= -EINVAL
; /* should be BUG() ? */
3987 static void memcg_get_hierarchical_limit(struct mem_cgroup
*memcg
,
3988 unsigned long long *mem_limit
, unsigned long long *memsw_limit
)
3990 struct cgroup
*cgroup
;
3991 unsigned long long min_limit
, min_memsw_limit
, tmp
;
3993 min_limit
= res_counter_read_u64(&memcg
->res
, RES_LIMIT
);
3994 min_memsw_limit
= res_counter_read_u64(&memcg
->memsw
, RES_LIMIT
);
3995 cgroup
= memcg
->css
.cgroup
;
3996 if (!memcg
->use_hierarchy
)
3999 while (cgroup
->parent
) {
4000 cgroup
= cgroup
->parent
;
4001 memcg
= mem_cgroup_from_cont(cgroup
);
4002 if (!memcg
->use_hierarchy
)
4004 tmp
= res_counter_read_u64(&memcg
->res
, RES_LIMIT
);
4005 min_limit
= min(min_limit
, tmp
);
4006 tmp
= res_counter_read_u64(&memcg
->memsw
, RES_LIMIT
);
4007 min_memsw_limit
= min(min_memsw_limit
, tmp
);
4010 *mem_limit
= min_limit
;
4011 *memsw_limit
= min_memsw_limit
;
4014 static int mem_cgroup_reset(struct cgroup
*cont
, unsigned int event
)
4016 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cont
);
4019 type
= MEMFILE_TYPE(event
);
4020 name
= MEMFILE_ATTR(event
);
4022 if (!do_swap_account
&& type
== _MEMSWAP
)
4028 res_counter_reset_max(&memcg
->res
);
4030 res_counter_reset_max(&memcg
->memsw
);
4034 res_counter_reset_failcnt(&memcg
->res
);
4036 res_counter_reset_failcnt(&memcg
->memsw
);
4043 static u64
mem_cgroup_move_charge_read(struct cgroup
*cgrp
,
4046 return mem_cgroup_from_cont(cgrp
)->move_charge_at_immigrate
;
4050 static int mem_cgroup_move_charge_write(struct cgroup
*cgrp
,
4051 struct cftype
*cft
, u64 val
)
4053 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cgrp
);
4055 if (val
>= (1 << NR_MOVE_TYPE
))
4058 * We check this value several times in both in can_attach() and
4059 * attach(), so we need cgroup lock to prevent this value from being
4063 memcg
->move_charge_at_immigrate
= val
;
4069 static int mem_cgroup_move_charge_write(struct cgroup
*cgrp
,
4070 struct cftype
*cft
, u64 val
)
4077 static int memcg_numa_stat_show(struct cgroup
*cont
, struct cftype
*cft
,
4081 unsigned long total_nr
, file_nr
, anon_nr
, unevictable_nr
;
4082 unsigned long node_nr
;
4083 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cont
);
4085 total_nr
= mem_cgroup_nr_lru_pages(memcg
, LRU_ALL
);
4086 seq_printf(m
, "total=%lu", total_nr
);
4087 for_each_node_state(nid
, N_HIGH_MEMORY
) {
4088 node_nr
= mem_cgroup_node_nr_lru_pages(memcg
, nid
, LRU_ALL
);
4089 seq_printf(m
, " N%d=%lu", nid
, node_nr
);
4093 file_nr
= mem_cgroup_nr_lru_pages(memcg
, LRU_ALL_FILE
);
4094 seq_printf(m
, "file=%lu", file_nr
);
4095 for_each_node_state(nid
, N_HIGH_MEMORY
) {
4096 node_nr
= mem_cgroup_node_nr_lru_pages(memcg
, nid
,
4098 seq_printf(m
, " N%d=%lu", nid
, node_nr
);
4102 anon_nr
= mem_cgroup_nr_lru_pages(memcg
, LRU_ALL_ANON
);
4103 seq_printf(m
, "anon=%lu", anon_nr
);
4104 for_each_node_state(nid
, N_HIGH_MEMORY
) {
4105 node_nr
= mem_cgroup_node_nr_lru_pages(memcg
, nid
,
4107 seq_printf(m
, " N%d=%lu", nid
, node_nr
);
4111 unevictable_nr
= mem_cgroup_nr_lru_pages(memcg
, BIT(LRU_UNEVICTABLE
));
4112 seq_printf(m
, "unevictable=%lu", unevictable_nr
);
4113 for_each_node_state(nid
, N_HIGH_MEMORY
) {
4114 node_nr
= mem_cgroup_node_nr_lru_pages(memcg
, nid
,
4115 BIT(LRU_UNEVICTABLE
));
4116 seq_printf(m
, " N%d=%lu", nid
, node_nr
);
4121 #endif /* CONFIG_NUMA */
4123 static const char * const mem_cgroup_lru_names
[] = {
4131 static inline void mem_cgroup_lru_names_not_uptodate(void)
4133 BUILD_BUG_ON(ARRAY_SIZE(mem_cgroup_lru_names
) != NR_LRU_LISTS
);
4136 static int memcg_stat_show(struct cgroup
*cont
, struct cftype
*cft
,
4139 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cont
);
4140 struct mem_cgroup
*mi
;
4143 for (i
= 0; i
< MEM_CGROUP_STAT_NSTATS
; i
++) {
4144 if (i
== MEM_CGROUP_STAT_SWAP
&& !do_swap_account
)
4146 seq_printf(m
, "%s %ld\n", mem_cgroup_stat_names
[i
],
4147 mem_cgroup_read_stat(memcg
, i
) * PAGE_SIZE
);
4150 for (i
= 0; i
< MEM_CGROUP_EVENTS_NSTATS
; i
++)
4151 seq_printf(m
, "%s %lu\n", mem_cgroup_events_names
[i
],
4152 mem_cgroup_read_events(memcg
, i
));
4154 for (i
= 0; i
< NR_LRU_LISTS
; i
++)
4155 seq_printf(m
, "%s %lu\n", mem_cgroup_lru_names
[i
],
4156 mem_cgroup_nr_lru_pages(memcg
, BIT(i
)) * PAGE_SIZE
);
4158 /* Hierarchical information */
4160 unsigned long long limit
, memsw_limit
;
4161 memcg_get_hierarchical_limit(memcg
, &limit
, &memsw_limit
);
4162 seq_printf(m
, "hierarchical_memory_limit %llu\n", limit
);
4163 if (do_swap_account
)
4164 seq_printf(m
, "hierarchical_memsw_limit %llu\n",
4168 for (i
= 0; i
< MEM_CGROUP_STAT_NSTATS
; i
++) {
4171 if (i
== MEM_CGROUP_STAT_SWAP
&& !do_swap_account
)
4173 for_each_mem_cgroup_tree(mi
, memcg
)
4174 val
+= mem_cgroup_read_stat(mi
, i
) * PAGE_SIZE
;
4175 seq_printf(m
, "total_%s %lld\n", mem_cgroup_stat_names
[i
], val
);
4178 for (i
= 0; i
< MEM_CGROUP_EVENTS_NSTATS
; i
++) {
4179 unsigned long long val
= 0;
4181 for_each_mem_cgroup_tree(mi
, memcg
)
4182 val
+= mem_cgroup_read_events(mi
, i
);
4183 seq_printf(m
, "total_%s %llu\n",
4184 mem_cgroup_events_names
[i
], val
);
4187 for (i
= 0; i
< NR_LRU_LISTS
; i
++) {
4188 unsigned long long val
= 0;
4190 for_each_mem_cgroup_tree(mi
, memcg
)
4191 val
+= mem_cgroup_nr_lru_pages(mi
, BIT(i
)) * PAGE_SIZE
;
4192 seq_printf(m
, "total_%s %llu\n", mem_cgroup_lru_names
[i
], val
);
4195 #ifdef CONFIG_DEBUG_VM
4198 struct mem_cgroup_per_zone
*mz
;
4199 struct zone_reclaim_stat
*rstat
;
4200 unsigned long recent_rotated
[2] = {0, 0};
4201 unsigned long recent_scanned
[2] = {0, 0};
4203 for_each_online_node(nid
)
4204 for (zid
= 0; zid
< MAX_NR_ZONES
; zid
++) {
4205 mz
= mem_cgroup_zoneinfo(memcg
, nid
, zid
);
4206 rstat
= &mz
->lruvec
.reclaim_stat
;
4208 recent_rotated
[0] += rstat
->recent_rotated
[0];
4209 recent_rotated
[1] += rstat
->recent_rotated
[1];
4210 recent_scanned
[0] += rstat
->recent_scanned
[0];
4211 recent_scanned
[1] += rstat
->recent_scanned
[1];
4213 seq_printf(m
, "recent_rotated_anon %lu\n", recent_rotated
[0]);
4214 seq_printf(m
, "recent_rotated_file %lu\n", recent_rotated
[1]);
4215 seq_printf(m
, "recent_scanned_anon %lu\n", recent_scanned
[0]);
4216 seq_printf(m
, "recent_scanned_file %lu\n", recent_scanned
[1]);
4223 static u64
mem_cgroup_swappiness_read(struct cgroup
*cgrp
, struct cftype
*cft
)
4225 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cgrp
);
4227 return mem_cgroup_swappiness(memcg
);
4230 static int mem_cgroup_swappiness_write(struct cgroup
*cgrp
, struct cftype
*cft
,
4233 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cgrp
);
4234 struct mem_cgroup
*parent
;
4239 if (cgrp
->parent
== NULL
)
4242 parent
= mem_cgroup_from_cont(cgrp
->parent
);
4246 /* If under hierarchy, only empty-root can set this value */
4247 if ((parent
->use_hierarchy
) ||
4248 (memcg
->use_hierarchy
&& !list_empty(&cgrp
->children
))) {
4253 memcg
->swappiness
= val
;
4260 static void __mem_cgroup_threshold(struct mem_cgroup
*memcg
, bool swap
)
4262 struct mem_cgroup_threshold_ary
*t
;
4268 t
= rcu_dereference(memcg
->thresholds
.primary
);
4270 t
= rcu_dereference(memcg
->memsw_thresholds
.primary
);
4275 usage
= mem_cgroup_usage(memcg
, swap
);
4278 * current_threshold points to threshold just below or equal to usage.
4279 * If it's not true, a threshold was crossed after last
4280 * call of __mem_cgroup_threshold().
4282 i
= t
->current_threshold
;
4285 * Iterate backward over array of thresholds starting from
4286 * current_threshold and check if a threshold is crossed.
4287 * If none of thresholds below usage is crossed, we read
4288 * only one element of the array here.
4290 for (; i
>= 0 && unlikely(t
->entries
[i
].threshold
> usage
); i
--)
4291 eventfd_signal(t
->entries
[i
].eventfd
, 1);
4293 /* i = current_threshold + 1 */
4297 * Iterate forward over array of thresholds starting from
4298 * current_threshold+1 and check if a threshold is crossed.
4299 * If none of thresholds above usage is crossed, we read
4300 * only one element of the array here.
4302 for (; i
< t
->size
&& unlikely(t
->entries
[i
].threshold
<= usage
); i
++)
4303 eventfd_signal(t
->entries
[i
].eventfd
, 1);
4305 /* Update current_threshold */
4306 t
->current_threshold
= i
- 1;
4311 static void mem_cgroup_threshold(struct mem_cgroup
*memcg
)
4314 __mem_cgroup_threshold(memcg
, false);
4315 if (do_swap_account
)
4316 __mem_cgroup_threshold(memcg
, true);
4318 memcg
= parent_mem_cgroup(memcg
);
4322 static int compare_thresholds(const void *a
, const void *b
)
4324 const struct mem_cgroup_threshold
*_a
= a
;
4325 const struct mem_cgroup_threshold
*_b
= b
;
4327 return _a
->threshold
- _b
->threshold
;
4330 static int mem_cgroup_oom_notify_cb(struct mem_cgroup
*memcg
)
4332 struct mem_cgroup_eventfd_list
*ev
;
4334 list_for_each_entry(ev
, &memcg
->oom_notify
, list
)
4335 eventfd_signal(ev
->eventfd
, 1);
4339 static void mem_cgroup_oom_notify(struct mem_cgroup
*memcg
)
4341 struct mem_cgroup
*iter
;
4343 for_each_mem_cgroup_tree(iter
, memcg
)
4344 mem_cgroup_oom_notify_cb(iter
);
4347 static int mem_cgroup_usage_register_event(struct cgroup
*cgrp
,
4348 struct cftype
*cft
, struct eventfd_ctx
*eventfd
, const char *args
)
4350 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cgrp
);
4351 struct mem_cgroup_thresholds
*thresholds
;
4352 struct mem_cgroup_threshold_ary
*new;
4353 int type
= MEMFILE_TYPE(cft
->private);
4354 u64 threshold
, usage
;
4357 ret
= res_counter_memparse_write_strategy(args
, &threshold
);
4361 mutex_lock(&memcg
->thresholds_lock
);
4364 thresholds
= &memcg
->thresholds
;
4365 else if (type
== _MEMSWAP
)
4366 thresholds
= &memcg
->memsw_thresholds
;
4370 usage
= mem_cgroup_usage(memcg
, type
== _MEMSWAP
);
4372 /* Check if a threshold crossed before adding a new one */
4373 if (thresholds
->primary
)
4374 __mem_cgroup_threshold(memcg
, type
== _MEMSWAP
);
4376 size
= thresholds
->primary
? thresholds
->primary
->size
+ 1 : 1;
4378 /* Allocate memory for new array of thresholds */
4379 new = kmalloc(sizeof(*new) + size
* sizeof(struct mem_cgroup_threshold
),
4387 /* Copy thresholds (if any) to new array */
4388 if (thresholds
->primary
) {
4389 memcpy(new->entries
, thresholds
->primary
->entries
, (size
- 1) *
4390 sizeof(struct mem_cgroup_threshold
));
4393 /* Add new threshold */
4394 new->entries
[size
- 1].eventfd
= eventfd
;
4395 new->entries
[size
- 1].threshold
= threshold
;
4397 /* Sort thresholds. Registering of new threshold isn't time-critical */
4398 sort(new->entries
, size
, sizeof(struct mem_cgroup_threshold
),
4399 compare_thresholds
, NULL
);
4401 /* Find current threshold */
4402 new->current_threshold
= -1;
4403 for (i
= 0; i
< size
; i
++) {
4404 if (new->entries
[i
].threshold
<= usage
) {
4406 * new->current_threshold will not be used until
4407 * rcu_assign_pointer(), so it's safe to increment
4410 ++new->current_threshold
;
4415 /* Free old spare buffer and save old primary buffer as spare */
4416 kfree(thresholds
->spare
);
4417 thresholds
->spare
= thresholds
->primary
;
4419 rcu_assign_pointer(thresholds
->primary
, new);
4421 /* To be sure that nobody uses thresholds */
4425 mutex_unlock(&memcg
->thresholds_lock
);
4430 static void mem_cgroup_usage_unregister_event(struct cgroup
*cgrp
,
4431 struct cftype
*cft
, struct eventfd_ctx
*eventfd
)
4433 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cgrp
);
4434 struct mem_cgroup_thresholds
*thresholds
;
4435 struct mem_cgroup_threshold_ary
*new;
4436 int type
= MEMFILE_TYPE(cft
->private);
4440 mutex_lock(&memcg
->thresholds_lock
);
4442 thresholds
= &memcg
->thresholds
;
4443 else if (type
== _MEMSWAP
)
4444 thresholds
= &memcg
->memsw_thresholds
;
4448 if (!thresholds
->primary
)
4451 usage
= mem_cgroup_usage(memcg
, type
== _MEMSWAP
);
4453 /* Check if a threshold crossed before removing */
4454 __mem_cgroup_threshold(memcg
, type
== _MEMSWAP
);
4456 /* Calculate new number of threshold */
4458 for (i
= 0; i
< thresholds
->primary
->size
; i
++) {
4459 if (thresholds
->primary
->entries
[i
].eventfd
!= eventfd
)
4463 new = thresholds
->spare
;
4465 /* Set thresholds array to NULL if we don't have thresholds */
4474 /* Copy thresholds and find current threshold */
4475 new->current_threshold
= -1;
4476 for (i
= 0, j
= 0; i
< thresholds
->primary
->size
; i
++) {
4477 if (thresholds
->primary
->entries
[i
].eventfd
== eventfd
)
4480 new->entries
[j
] = thresholds
->primary
->entries
[i
];
4481 if (new->entries
[j
].threshold
<= usage
) {
4483 * new->current_threshold will not be used
4484 * until rcu_assign_pointer(), so it's safe to increment
4487 ++new->current_threshold
;
4493 /* Swap primary and spare array */
4494 thresholds
->spare
= thresholds
->primary
;
4495 /* If all events are unregistered, free the spare array */
4497 kfree(thresholds
->spare
);
4498 thresholds
->spare
= NULL
;
4501 rcu_assign_pointer(thresholds
->primary
, new);
4503 /* To be sure that nobody uses thresholds */
4506 mutex_unlock(&memcg
->thresholds_lock
);
4509 static int mem_cgroup_oom_register_event(struct cgroup
*cgrp
,
4510 struct cftype
*cft
, struct eventfd_ctx
*eventfd
, const char *args
)
4512 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cgrp
);
4513 struct mem_cgroup_eventfd_list
*event
;
4514 int type
= MEMFILE_TYPE(cft
->private);
4516 BUG_ON(type
!= _OOM_TYPE
);
4517 event
= kmalloc(sizeof(*event
), GFP_KERNEL
);
4521 spin_lock(&memcg_oom_lock
);
4523 event
->eventfd
= eventfd
;
4524 list_add(&event
->list
, &memcg
->oom_notify
);
4526 /* already in OOM ? */
4527 if (atomic_read(&memcg
->under_oom
))
4528 eventfd_signal(eventfd
, 1);
4529 spin_unlock(&memcg_oom_lock
);
4534 static void mem_cgroup_oom_unregister_event(struct cgroup
*cgrp
,
4535 struct cftype
*cft
, struct eventfd_ctx
*eventfd
)
4537 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cgrp
);
4538 struct mem_cgroup_eventfd_list
*ev
, *tmp
;
4539 int type
= MEMFILE_TYPE(cft
->private);
4541 BUG_ON(type
!= _OOM_TYPE
);
4543 spin_lock(&memcg_oom_lock
);
4545 list_for_each_entry_safe(ev
, tmp
, &memcg
->oom_notify
, list
) {
4546 if (ev
->eventfd
== eventfd
) {
4547 list_del(&ev
->list
);
4552 spin_unlock(&memcg_oom_lock
);
4555 static int mem_cgroup_oom_control_read(struct cgroup
*cgrp
,
4556 struct cftype
*cft
, struct cgroup_map_cb
*cb
)
4558 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cgrp
);
4560 cb
->fill(cb
, "oom_kill_disable", memcg
->oom_kill_disable
);
4562 if (atomic_read(&memcg
->under_oom
))
4563 cb
->fill(cb
, "under_oom", 1);
4565 cb
->fill(cb
, "under_oom", 0);
4569 static int mem_cgroup_oom_control_write(struct cgroup
*cgrp
,
4570 struct cftype
*cft
, u64 val
)
4572 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cgrp
);
4573 struct mem_cgroup
*parent
;
4575 /* cannot set to root cgroup and only 0 and 1 are allowed */
4576 if (!cgrp
->parent
|| !((val
== 0) || (val
== 1)))
4579 parent
= mem_cgroup_from_cont(cgrp
->parent
);
4582 /* oom-kill-disable is a flag for subhierarchy. */
4583 if ((parent
->use_hierarchy
) ||
4584 (memcg
->use_hierarchy
&& !list_empty(&cgrp
->children
))) {
4588 memcg
->oom_kill_disable
= val
;
4590 memcg_oom_recover(memcg
);
4595 #ifdef CONFIG_MEMCG_KMEM
4596 static int memcg_init_kmem(struct mem_cgroup
*memcg
, struct cgroup_subsys
*ss
)
4598 return mem_cgroup_sockets_init(memcg
, ss
);
4601 static void kmem_cgroup_destroy(struct mem_cgroup
*memcg
)
4603 mem_cgroup_sockets_destroy(memcg
);
4606 static int memcg_init_kmem(struct mem_cgroup
*memcg
, struct cgroup_subsys
*ss
)
4611 static void kmem_cgroup_destroy(struct mem_cgroup
*memcg
)
4616 static struct cftype mem_cgroup_files
[] = {
4618 .name
= "usage_in_bytes",
4619 .private = MEMFILE_PRIVATE(_MEM
, RES_USAGE
),
4620 .read
= mem_cgroup_read
,
4621 .register_event
= mem_cgroup_usage_register_event
,
4622 .unregister_event
= mem_cgroup_usage_unregister_event
,
4625 .name
= "max_usage_in_bytes",
4626 .private = MEMFILE_PRIVATE(_MEM
, RES_MAX_USAGE
),
4627 .trigger
= mem_cgroup_reset
,
4628 .read
= mem_cgroup_read
,
4631 .name
= "limit_in_bytes",
4632 .private = MEMFILE_PRIVATE(_MEM
, RES_LIMIT
),
4633 .write_string
= mem_cgroup_write
,
4634 .read
= mem_cgroup_read
,
4637 .name
= "soft_limit_in_bytes",
4638 .private = MEMFILE_PRIVATE(_MEM
, RES_SOFT_LIMIT
),
4639 .write_string
= mem_cgroup_write
,
4640 .read
= mem_cgroup_read
,
4644 .private = MEMFILE_PRIVATE(_MEM
, RES_FAILCNT
),
4645 .trigger
= mem_cgroup_reset
,
4646 .read
= mem_cgroup_read
,
4650 .read_seq_string
= memcg_stat_show
,
4653 .name
= "force_empty",
4654 .trigger
= mem_cgroup_force_empty_write
,
4657 .name
= "use_hierarchy",
4658 .write_u64
= mem_cgroup_hierarchy_write
,
4659 .read_u64
= mem_cgroup_hierarchy_read
,
4662 .name
= "swappiness",
4663 .read_u64
= mem_cgroup_swappiness_read
,
4664 .write_u64
= mem_cgroup_swappiness_write
,
4667 .name
= "move_charge_at_immigrate",
4668 .read_u64
= mem_cgroup_move_charge_read
,
4669 .write_u64
= mem_cgroup_move_charge_write
,
4672 .name
= "oom_control",
4673 .read_map
= mem_cgroup_oom_control_read
,
4674 .write_u64
= mem_cgroup_oom_control_write
,
4675 .register_event
= mem_cgroup_oom_register_event
,
4676 .unregister_event
= mem_cgroup_oom_unregister_event
,
4677 .private = MEMFILE_PRIVATE(_OOM_TYPE
, OOM_CONTROL
),
4681 .name
= "numa_stat",
4682 .read_seq_string
= memcg_numa_stat_show
,
4685 #ifdef CONFIG_MEMCG_SWAP
4687 .name
= "memsw.usage_in_bytes",
4688 .private = MEMFILE_PRIVATE(_MEMSWAP
, RES_USAGE
),
4689 .read
= mem_cgroup_read
,
4690 .register_event
= mem_cgroup_usage_register_event
,
4691 .unregister_event
= mem_cgroup_usage_unregister_event
,
4694 .name
= "memsw.max_usage_in_bytes",
4695 .private = MEMFILE_PRIVATE(_MEMSWAP
, RES_MAX_USAGE
),
4696 .trigger
= mem_cgroup_reset
,
4697 .read
= mem_cgroup_read
,
4700 .name
= "memsw.limit_in_bytes",
4701 .private = MEMFILE_PRIVATE(_MEMSWAP
, RES_LIMIT
),
4702 .write_string
= mem_cgroup_write
,
4703 .read
= mem_cgroup_read
,
4706 .name
= "memsw.failcnt",
4707 .private = MEMFILE_PRIVATE(_MEMSWAP
, RES_FAILCNT
),
4708 .trigger
= mem_cgroup_reset
,
4709 .read
= mem_cgroup_read
,
4712 { }, /* terminate */
4715 static int alloc_mem_cgroup_per_zone_info(struct mem_cgroup
*memcg
, int node
)
4717 struct mem_cgroup_per_node
*pn
;
4718 struct mem_cgroup_per_zone
*mz
;
4719 int zone
, tmp
= node
;
4721 * This routine is called against possible nodes.
4722 * But it's BUG to call kmalloc() against offline node.
4724 * TODO: this routine can waste much memory for nodes which will
4725 * never be onlined. It's better to use memory hotplug callback
4728 if (!node_state(node
, N_NORMAL_MEMORY
))
4730 pn
= kzalloc_node(sizeof(*pn
), GFP_KERNEL
, tmp
);
4734 for (zone
= 0; zone
< MAX_NR_ZONES
; zone
++) {
4735 mz
= &pn
->zoneinfo
[zone
];
4736 lruvec_init(&mz
->lruvec
, &NODE_DATA(node
)->node_zones
[zone
]);
4737 mz
->usage_in_excess
= 0;
4738 mz
->on_tree
= false;
4741 memcg
->info
.nodeinfo
[node
] = pn
;
4745 static void free_mem_cgroup_per_zone_info(struct mem_cgroup
*memcg
, int node
)
4747 kfree(memcg
->info
.nodeinfo
[node
]);
4750 static struct mem_cgroup
*mem_cgroup_alloc(void)
4752 struct mem_cgroup
*memcg
;
4753 int size
= sizeof(struct mem_cgroup
);
4755 /* Can be very big if MAX_NUMNODES is very big */
4756 if (size
< PAGE_SIZE
)
4757 memcg
= kzalloc(size
, GFP_KERNEL
);
4759 memcg
= vzalloc(size
);
4764 memcg
->stat
= alloc_percpu(struct mem_cgroup_stat_cpu
);
4767 spin_lock_init(&memcg
->pcp_counter_lock
);
4771 if (size
< PAGE_SIZE
)
4779 * Helpers for freeing a kmalloc()ed/vzalloc()ed mem_cgroup by RCU,
4780 * but in process context. The work_freeing structure is overlaid
4781 * on the rcu_freeing structure, which itself is overlaid on memsw.
4783 static void free_work(struct work_struct
*work
)
4785 struct mem_cgroup
*memcg
;
4786 int size
= sizeof(struct mem_cgroup
);
4788 memcg
= container_of(work
, struct mem_cgroup
, work_freeing
);
4790 * We need to make sure that (at least for now), the jump label
4791 * destruction code runs outside of the cgroup lock. This is because
4792 * get_online_cpus(), which is called from the static_branch update,
4793 * can't be called inside the cgroup_lock. cpusets are the ones
4794 * enforcing this dependency, so if they ever change, we might as well.
4796 * schedule_work() will guarantee this happens. Be careful if you need
4797 * to move this code around, and make sure it is outside
4800 disarm_sock_keys(memcg
);
4801 if (size
< PAGE_SIZE
)
4807 static void free_rcu(struct rcu_head
*rcu_head
)
4809 struct mem_cgroup
*memcg
;
4811 memcg
= container_of(rcu_head
, struct mem_cgroup
, rcu_freeing
);
4812 INIT_WORK(&memcg
->work_freeing
, free_work
);
4813 schedule_work(&memcg
->work_freeing
);
4817 * At destroying mem_cgroup, references from swap_cgroup can remain.
4818 * (scanning all at force_empty is too costly...)
4820 * Instead of clearing all references at force_empty, we remember
4821 * the number of reference from swap_cgroup and free mem_cgroup when
4822 * it goes down to 0.
4824 * Removal of cgroup itself succeeds regardless of refs from swap.
4827 static void __mem_cgroup_free(struct mem_cgroup
*memcg
)
4831 mem_cgroup_remove_from_trees(memcg
);
4832 free_css_id(&mem_cgroup_subsys
, &memcg
->css
);
4835 free_mem_cgroup_per_zone_info(memcg
, node
);
4837 free_percpu(memcg
->stat
);
4838 call_rcu(&memcg
->rcu_freeing
, free_rcu
);
4841 static void mem_cgroup_get(struct mem_cgroup
*memcg
)
4843 atomic_inc(&memcg
->refcnt
);
4846 static void __mem_cgroup_put(struct mem_cgroup
*memcg
, int count
)
4848 if (atomic_sub_and_test(count
, &memcg
->refcnt
)) {
4849 struct mem_cgroup
*parent
= parent_mem_cgroup(memcg
);
4850 __mem_cgroup_free(memcg
);
4852 mem_cgroup_put(parent
);
4856 static void mem_cgroup_put(struct mem_cgroup
*memcg
)
4858 __mem_cgroup_put(memcg
, 1);
4862 * Returns the parent mem_cgroup in memcgroup hierarchy with hierarchy enabled.
4864 struct mem_cgroup
*parent_mem_cgroup(struct mem_cgroup
*memcg
)
4866 if (!memcg
->res
.parent
)
4868 return mem_cgroup_from_res_counter(memcg
->res
.parent
, res
);
4870 EXPORT_SYMBOL(parent_mem_cgroup
);
4872 #ifdef CONFIG_MEMCG_SWAP
4873 static void __init
enable_swap_cgroup(void)
4875 if (!mem_cgroup_disabled() && really_do_swap_account
)
4876 do_swap_account
= 1;
4879 static void __init
enable_swap_cgroup(void)
4884 static int mem_cgroup_soft_limit_tree_init(void)
4886 struct mem_cgroup_tree_per_node
*rtpn
;
4887 struct mem_cgroup_tree_per_zone
*rtpz
;
4888 int tmp
, node
, zone
;
4890 for_each_node(node
) {
4892 if (!node_state(node
, N_NORMAL_MEMORY
))
4894 rtpn
= kzalloc_node(sizeof(*rtpn
), GFP_KERNEL
, tmp
);
4898 soft_limit_tree
.rb_tree_per_node
[node
] = rtpn
;
4900 for (zone
= 0; zone
< MAX_NR_ZONES
; zone
++) {
4901 rtpz
= &rtpn
->rb_tree_per_zone
[zone
];
4902 rtpz
->rb_root
= RB_ROOT
;
4903 spin_lock_init(&rtpz
->lock
);
4909 for_each_node(node
) {
4910 if (!soft_limit_tree
.rb_tree_per_node
[node
])
4912 kfree(soft_limit_tree
.rb_tree_per_node
[node
]);
4913 soft_limit_tree
.rb_tree_per_node
[node
] = NULL
;
4919 static struct cgroup_subsys_state
* __ref
4920 mem_cgroup_create(struct cgroup
*cont
)
4922 struct mem_cgroup
*memcg
, *parent
;
4923 long error
= -ENOMEM
;
4926 memcg
= mem_cgroup_alloc();
4928 return ERR_PTR(error
);
4931 if (alloc_mem_cgroup_per_zone_info(memcg
, node
))
4935 if (cont
->parent
== NULL
) {
4937 enable_swap_cgroup();
4939 if (mem_cgroup_soft_limit_tree_init())
4941 root_mem_cgroup
= memcg
;
4942 for_each_possible_cpu(cpu
) {
4943 struct memcg_stock_pcp
*stock
=
4944 &per_cpu(memcg_stock
, cpu
);
4945 INIT_WORK(&stock
->work
, drain_local_stock
);
4947 hotcpu_notifier(memcg_cpu_hotplug_callback
, 0);
4949 parent
= mem_cgroup_from_cont(cont
->parent
);
4950 memcg
->use_hierarchy
= parent
->use_hierarchy
;
4951 memcg
->oom_kill_disable
= parent
->oom_kill_disable
;
4954 if (parent
&& parent
->use_hierarchy
) {
4955 res_counter_init(&memcg
->res
, &parent
->res
);
4956 res_counter_init(&memcg
->memsw
, &parent
->memsw
);
4958 * We increment refcnt of the parent to ensure that we can
4959 * safely access it on res_counter_charge/uncharge.
4960 * This refcnt will be decremented when freeing this
4961 * mem_cgroup(see mem_cgroup_put).
4963 mem_cgroup_get(parent
);
4965 res_counter_init(&memcg
->res
, NULL
);
4966 res_counter_init(&memcg
->memsw
, NULL
);
4968 memcg
->last_scanned_node
= MAX_NUMNODES
;
4969 INIT_LIST_HEAD(&memcg
->oom_notify
);
4972 memcg
->swappiness
= mem_cgroup_swappiness(parent
);
4973 atomic_set(&memcg
->refcnt
, 1);
4974 memcg
->move_charge_at_immigrate
= 0;
4975 mutex_init(&memcg
->thresholds_lock
);
4976 spin_lock_init(&memcg
->move_lock
);
4978 error
= memcg_init_kmem(memcg
, &mem_cgroup_subsys
);
4981 * We call put now because our (and parent's) refcnts
4982 * are already in place. mem_cgroup_put() will internally
4983 * call __mem_cgroup_free, so return directly
4985 mem_cgroup_put(memcg
);
4986 return ERR_PTR(error
);
4990 __mem_cgroup_free(memcg
);
4991 return ERR_PTR(error
);
4994 static int mem_cgroup_pre_destroy(struct cgroup
*cont
)
4996 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cont
);
4998 return mem_cgroup_force_empty(memcg
, false);
5001 static void mem_cgroup_destroy(struct cgroup
*cont
)
5003 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cont
);
5005 kmem_cgroup_destroy(memcg
);
5007 mem_cgroup_put(memcg
);
5011 /* Handlers for move charge at task migration. */
5012 #define PRECHARGE_COUNT_AT_ONCE 256
5013 static int mem_cgroup_do_precharge(unsigned long count
)
5016 int batch_count
= PRECHARGE_COUNT_AT_ONCE
;
5017 struct mem_cgroup
*memcg
= mc
.to
;
5019 if (mem_cgroup_is_root(memcg
)) {
5020 mc
.precharge
+= count
;
5021 /* we don't need css_get for root */
5024 /* try to charge at once */
5026 struct res_counter
*dummy
;
5028 * "memcg" cannot be under rmdir() because we've already checked
5029 * by cgroup_lock_live_cgroup() that it is not removed and we
5030 * are still under the same cgroup_mutex. So we can postpone
5033 if (res_counter_charge(&memcg
->res
, PAGE_SIZE
* count
, &dummy
))
5035 if (do_swap_account
&& res_counter_charge(&memcg
->memsw
,
5036 PAGE_SIZE
* count
, &dummy
)) {
5037 res_counter_uncharge(&memcg
->res
, PAGE_SIZE
* count
);
5040 mc
.precharge
+= count
;
5044 /* fall back to one by one charge */
5046 if (signal_pending(current
)) {
5050 if (!batch_count
--) {
5051 batch_count
= PRECHARGE_COUNT_AT_ONCE
;
5054 ret
= __mem_cgroup_try_charge(NULL
,
5055 GFP_KERNEL
, 1, &memcg
, false);
5057 /* mem_cgroup_clear_mc() will do uncharge later */
5065 * get_mctgt_type - get target type of moving charge
5066 * @vma: the vma the pte to be checked belongs
5067 * @addr: the address corresponding to the pte to be checked
5068 * @ptent: the pte to be checked
5069 * @target: the pointer the target page or swap ent will be stored(can be NULL)
5072 * 0(MC_TARGET_NONE): if the pte is not a target for move charge.
5073 * 1(MC_TARGET_PAGE): if the page corresponding to this pte is a target for
5074 * move charge. if @target is not NULL, the page is stored in target->page
5075 * with extra refcnt got(Callers should handle it).
5076 * 2(MC_TARGET_SWAP): if the swap entry corresponding to this pte is a
5077 * target for charge migration. if @target is not NULL, the entry is stored
5080 * Called with pte lock held.
5087 enum mc_target_type
{
5093 static struct page
*mc_handle_present_pte(struct vm_area_struct
*vma
,
5094 unsigned long addr
, pte_t ptent
)
5096 struct page
*page
= vm_normal_page(vma
, addr
, ptent
);
5098 if (!page
|| !page_mapped(page
))
5100 if (PageAnon(page
)) {
5101 /* we don't move shared anon */
5104 } else if (!move_file())
5105 /* we ignore mapcount for file pages */
5107 if (!get_page_unless_zero(page
))
5114 static struct page
*mc_handle_swap_pte(struct vm_area_struct
*vma
,
5115 unsigned long addr
, pte_t ptent
, swp_entry_t
*entry
)
5117 struct page
*page
= NULL
;
5118 swp_entry_t ent
= pte_to_swp_entry(ptent
);
5120 if (!move_anon() || non_swap_entry(ent
))
5123 * Because lookup_swap_cache() updates some statistics counter,
5124 * we call find_get_page() with swapper_space directly.
5126 page
= find_get_page(&swapper_space
, ent
.val
);
5127 if (do_swap_account
)
5128 entry
->val
= ent
.val
;
5133 static struct page
*mc_handle_swap_pte(struct vm_area_struct
*vma
,
5134 unsigned long addr
, pte_t ptent
, swp_entry_t
*entry
)
5140 static struct page
*mc_handle_file_pte(struct vm_area_struct
*vma
,
5141 unsigned long addr
, pte_t ptent
, swp_entry_t
*entry
)
5143 struct page
*page
= NULL
;
5144 struct address_space
*mapping
;
5147 if (!vma
->vm_file
) /* anonymous vma */
5152 mapping
= vma
->vm_file
->f_mapping
;
5153 if (pte_none(ptent
))
5154 pgoff
= linear_page_index(vma
, addr
);
5155 else /* pte_file(ptent) is true */
5156 pgoff
= pte_to_pgoff(ptent
);
5158 /* page is moved even if it's not RSS of this task(page-faulted). */
5159 page
= find_get_page(mapping
, pgoff
);
5162 /* shmem/tmpfs may report page out on swap: account for that too. */
5163 if (radix_tree_exceptional_entry(page
)) {
5164 swp_entry_t swap
= radix_to_swp_entry(page
);
5165 if (do_swap_account
)
5167 page
= find_get_page(&swapper_space
, swap
.val
);
5173 static enum mc_target_type
get_mctgt_type(struct vm_area_struct
*vma
,
5174 unsigned long addr
, pte_t ptent
, union mc_target
*target
)
5176 struct page
*page
= NULL
;
5177 struct page_cgroup
*pc
;
5178 enum mc_target_type ret
= MC_TARGET_NONE
;
5179 swp_entry_t ent
= { .val
= 0 };
5181 if (pte_present(ptent
))
5182 page
= mc_handle_present_pte(vma
, addr
, ptent
);
5183 else if (is_swap_pte(ptent
))
5184 page
= mc_handle_swap_pte(vma
, addr
, ptent
, &ent
);
5185 else if (pte_none(ptent
) || pte_file(ptent
))
5186 page
= mc_handle_file_pte(vma
, addr
, ptent
, &ent
);
5188 if (!page
&& !ent
.val
)
5191 pc
= lookup_page_cgroup(page
);
5193 * Do only loose check w/o page_cgroup lock.
5194 * mem_cgroup_move_account() checks the pc is valid or not under
5197 if (PageCgroupUsed(pc
) && pc
->mem_cgroup
== mc
.from
) {
5198 ret
= MC_TARGET_PAGE
;
5200 target
->page
= page
;
5202 if (!ret
|| !target
)
5205 /* There is a swap entry and a page doesn't exist or isn't charged */
5206 if (ent
.val
&& !ret
&&
5207 css_id(&mc
.from
->css
) == lookup_swap_cgroup_id(ent
)) {
5208 ret
= MC_TARGET_SWAP
;
5215 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
5217 * We don't consider swapping or file mapped pages because THP does not
5218 * support them for now.
5219 * Caller should make sure that pmd_trans_huge(pmd) is true.
5221 static enum mc_target_type
get_mctgt_type_thp(struct vm_area_struct
*vma
,
5222 unsigned long addr
, pmd_t pmd
, union mc_target
*target
)
5224 struct page
*page
= NULL
;
5225 struct page_cgroup
*pc
;
5226 enum mc_target_type ret
= MC_TARGET_NONE
;
5228 page
= pmd_page(pmd
);
5229 VM_BUG_ON(!page
|| !PageHead(page
));
5232 pc
= lookup_page_cgroup(page
);
5233 if (PageCgroupUsed(pc
) && pc
->mem_cgroup
== mc
.from
) {
5234 ret
= MC_TARGET_PAGE
;
5237 target
->page
= page
;
5243 static inline enum mc_target_type
get_mctgt_type_thp(struct vm_area_struct
*vma
,
5244 unsigned long addr
, pmd_t pmd
, union mc_target
*target
)
5246 return MC_TARGET_NONE
;
5250 static int mem_cgroup_count_precharge_pte_range(pmd_t
*pmd
,
5251 unsigned long addr
, unsigned long end
,
5252 struct mm_walk
*walk
)
5254 struct vm_area_struct
*vma
= walk
->private;
5258 if (pmd_trans_huge_lock(pmd
, vma
) == 1) {
5259 if (get_mctgt_type_thp(vma
, addr
, *pmd
, NULL
) == MC_TARGET_PAGE
)
5260 mc
.precharge
+= HPAGE_PMD_NR
;
5261 spin_unlock(&vma
->vm_mm
->page_table_lock
);
5265 if (pmd_trans_unstable(pmd
))
5267 pte
= pte_offset_map_lock(vma
->vm_mm
, pmd
, addr
, &ptl
);
5268 for (; addr
!= end
; pte
++, addr
+= PAGE_SIZE
)
5269 if (get_mctgt_type(vma
, addr
, *pte
, NULL
))
5270 mc
.precharge
++; /* increment precharge temporarily */
5271 pte_unmap_unlock(pte
- 1, ptl
);
5277 static unsigned long mem_cgroup_count_precharge(struct mm_struct
*mm
)
5279 unsigned long precharge
;
5280 struct vm_area_struct
*vma
;
5282 down_read(&mm
->mmap_sem
);
5283 for (vma
= mm
->mmap
; vma
; vma
= vma
->vm_next
) {
5284 struct mm_walk mem_cgroup_count_precharge_walk
= {
5285 .pmd_entry
= mem_cgroup_count_precharge_pte_range
,
5289 if (is_vm_hugetlb_page(vma
))
5291 walk_page_range(vma
->vm_start
, vma
->vm_end
,
5292 &mem_cgroup_count_precharge_walk
);
5294 up_read(&mm
->mmap_sem
);
5296 precharge
= mc
.precharge
;
5302 static int mem_cgroup_precharge_mc(struct mm_struct
*mm
)
5304 unsigned long precharge
= mem_cgroup_count_precharge(mm
);
5306 VM_BUG_ON(mc
.moving_task
);
5307 mc
.moving_task
= current
;
5308 return mem_cgroup_do_precharge(precharge
);
5311 /* cancels all extra charges on mc.from and mc.to, and wakes up all waiters. */
5312 static void __mem_cgroup_clear_mc(void)
5314 struct mem_cgroup
*from
= mc
.from
;
5315 struct mem_cgroup
*to
= mc
.to
;
5317 /* we must uncharge all the leftover precharges from mc.to */
5319 __mem_cgroup_cancel_charge(mc
.to
, mc
.precharge
);
5323 * we didn't uncharge from mc.from at mem_cgroup_move_account(), so
5324 * we must uncharge here.
5326 if (mc
.moved_charge
) {
5327 __mem_cgroup_cancel_charge(mc
.from
, mc
.moved_charge
);
5328 mc
.moved_charge
= 0;
5330 /* we must fixup refcnts and charges */
5331 if (mc
.moved_swap
) {
5332 /* uncharge swap account from the old cgroup */
5333 if (!mem_cgroup_is_root(mc
.from
))
5334 res_counter_uncharge(&mc
.from
->memsw
,
5335 PAGE_SIZE
* mc
.moved_swap
);
5336 __mem_cgroup_put(mc
.from
, mc
.moved_swap
);
5338 if (!mem_cgroup_is_root(mc
.to
)) {
5340 * we charged both to->res and to->memsw, so we should
5343 res_counter_uncharge(&mc
.to
->res
,
5344 PAGE_SIZE
* mc
.moved_swap
);
5346 /* we've already done mem_cgroup_get(mc.to) */
5349 memcg_oom_recover(from
);
5350 memcg_oom_recover(to
);
5351 wake_up_all(&mc
.waitq
);
5354 static void mem_cgroup_clear_mc(void)
5356 struct mem_cgroup
*from
= mc
.from
;
5359 * we must clear moving_task before waking up waiters at the end of
5362 mc
.moving_task
= NULL
;
5363 __mem_cgroup_clear_mc();
5364 spin_lock(&mc
.lock
);
5367 spin_unlock(&mc
.lock
);
5368 mem_cgroup_end_move(from
);
5371 static int mem_cgroup_can_attach(struct cgroup
*cgroup
,
5372 struct cgroup_taskset
*tset
)
5374 struct task_struct
*p
= cgroup_taskset_first(tset
);
5376 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cgroup
);
5378 if (memcg
->move_charge_at_immigrate
) {
5379 struct mm_struct
*mm
;
5380 struct mem_cgroup
*from
= mem_cgroup_from_task(p
);
5382 VM_BUG_ON(from
== memcg
);
5384 mm
= get_task_mm(p
);
5387 /* We move charges only when we move a owner of the mm */
5388 if (mm
->owner
== p
) {
5391 VM_BUG_ON(mc
.precharge
);
5392 VM_BUG_ON(mc
.moved_charge
);
5393 VM_BUG_ON(mc
.moved_swap
);
5394 mem_cgroup_start_move(from
);
5395 spin_lock(&mc
.lock
);
5398 spin_unlock(&mc
.lock
);
5399 /* We set mc.moving_task later */
5401 ret
= mem_cgroup_precharge_mc(mm
);
5403 mem_cgroup_clear_mc();
5410 static void mem_cgroup_cancel_attach(struct cgroup
*cgroup
,
5411 struct cgroup_taskset
*tset
)
5413 mem_cgroup_clear_mc();
5416 static int mem_cgroup_move_charge_pte_range(pmd_t
*pmd
,
5417 unsigned long addr
, unsigned long end
,
5418 struct mm_walk
*walk
)
5421 struct vm_area_struct
*vma
= walk
->private;
5424 enum mc_target_type target_type
;
5425 union mc_target target
;
5427 struct page_cgroup
*pc
;
5430 * We don't take compound_lock() here but no race with splitting thp
5432 * - if pmd_trans_huge_lock() returns 1, the relevant thp is not
5433 * under splitting, which means there's no concurrent thp split,
5434 * - if another thread runs into split_huge_page() just after we
5435 * entered this if-block, the thread must wait for page table lock
5436 * to be unlocked in __split_huge_page_splitting(), where the main
5437 * part of thp split is not executed yet.
5439 if (pmd_trans_huge_lock(pmd
, vma
) == 1) {
5440 if (mc
.precharge
< HPAGE_PMD_NR
) {
5441 spin_unlock(&vma
->vm_mm
->page_table_lock
);
5444 target_type
= get_mctgt_type_thp(vma
, addr
, *pmd
, &target
);
5445 if (target_type
== MC_TARGET_PAGE
) {
5447 if (!isolate_lru_page(page
)) {
5448 pc
= lookup_page_cgroup(page
);
5449 if (!mem_cgroup_move_account(page
, HPAGE_PMD_NR
,
5450 pc
, mc
.from
, mc
.to
)) {
5451 mc
.precharge
-= HPAGE_PMD_NR
;
5452 mc
.moved_charge
+= HPAGE_PMD_NR
;
5454 putback_lru_page(page
);
5458 spin_unlock(&vma
->vm_mm
->page_table_lock
);
5462 if (pmd_trans_unstable(pmd
))
5465 pte
= pte_offset_map_lock(vma
->vm_mm
, pmd
, addr
, &ptl
);
5466 for (; addr
!= end
; addr
+= PAGE_SIZE
) {
5467 pte_t ptent
= *(pte
++);
5473 switch (get_mctgt_type(vma
, addr
, ptent
, &target
)) {
5474 case MC_TARGET_PAGE
:
5476 if (isolate_lru_page(page
))
5478 pc
= lookup_page_cgroup(page
);
5479 if (!mem_cgroup_move_account(page
, 1, pc
,
5482 /* we uncharge from mc.from later. */
5485 putback_lru_page(page
);
5486 put
: /* get_mctgt_type() gets the page */
5489 case MC_TARGET_SWAP
:
5491 if (!mem_cgroup_move_swap_account(ent
, mc
.from
, mc
.to
)) {
5493 /* we fixup refcnts and charges later. */
5501 pte_unmap_unlock(pte
- 1, ptl
);
5506 * We have consumed all precharges we got in can_attach().
5507 * We try charge one by one, but don't do any additional
5508 * charges to mc.to if we have failed in charge once in attach()
5511 ret
= mem_cgroup_do_precharge(1);
5519 static void mem_cgroup_move_charge(struct mm_struct
*mm
)
5521 struct vm_area_struct
*vma
;
5523 lru_add_drain_all();
5525 if (unlikely(!down_read_trylock(&mm
->mmap_sem
))) {
5527 * Someone who are holding the mmap_sem might be waiting in
5528 * waitq. So we cancel all extra charges, wake up all waiters,
5529 * and retry. Because we cancel precharges, we might not be able
5530 * to move enough charges, but moving charge is a best-effort
5531 * feature anyway, so it wouldn't be a big problem.
5533 __mem_cgroup_clear_mc();
5537 for (vma
= mm
->mmap
; vma
; vma
= vma
->vm_next
) {
5539 struct mm_walk mem_cgroup_move_charge_walk
= {
5540 .pmd_entry
= mem_cgroup_move_charge_pte_range
,
5544 if (is_vm_hugetlb_page(vma
))
5546 ret
= walk_page_range(vma
->vm_start
, vma
->vm_end
,
5547 &mem_cgroup_move_charge_walk
);
5550 * means we have consumed all precharges and failed in
5551 * doing additional charge. Just abandon here.
5555 up_read(&mm
->mmap_sem
);
5558 static void mem_cgroup_move_task(struct cgroup
*cont
,
5559 struct cgroup_taskset
*tset
)
5561 struct task_struct
*p
= cgroup_taskset_first(tset
);
5562 struct mm_struct
*mm
= get_task_mm(p
);
5566 mem_cgroup_move_charge(mm
);
5570 mem_cgroup_clear_mc();
5572 #else /* !CONFIG_MMU */
5573 static int mem_cgroup_can_attach(struct cgroup
*cgroup
,
5574 struct cgroup_taskset
*tset
)
5578 static void mem_cgroup_cancel_attach(struct cgroup
*cgroup
,
5579 struct cgroup_taskset
*tset
)
5582 static void mem_cgroup_move_task(struct cgroup
*cont
,
5583 struct cgroup_taskset
*tset
)
5588 struct cgroup_subsys mem_cgroup_subsys
= {
5590 .subsys_id
= mem_cgroup_subsys_id
,
5591 .create
= mem_cgroup_create
,
5592 .pre_destroy
= mem_cgroup_pre_destroy
,
5593 .destroy
= mem_cgroup_destroy
,
5594 .can_attach
= mem_cgroup_can_attach
,
5595 .cancel_attach
= mem_cgroup_cancel_attach
,
5596 .attach
= mem_cgroup_move_task
,
5597 .base_cftypes
= mem_cgroup_files
,
5600 .__DEPRECATED_clear_css_refs
= true,
5603 #ifdef CONFIG_MEMCG_SWAP
5604 static int __init
enable_swap_account(char *s
)
5606 /* consider enabled if no parameter or 1 is given */
5607 if (!strcmp(s
, "1"))
5608 really_do_swap_account
= 1;
5609 else if (!strcmp(s
, "0"))
5610 really_do_swap_account
= 0;
5613 __setup("swapaccount=", enable_swap_account
);