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_CGROUP_MEM_RES_CTLR_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_CGROUP_MEM_RES_CTLR_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_SWAPOUT
, /* # of pages, swapped out */
91 MEM_CGROUP_STAT_DATA
, /* end of data requires synchronization */
92 MEM_CGROUP_STAT_NSTATS
,
95 enum mem_cgroup_events_index
{
96 MEM_CGROUP_EVENTS_PGPGIN
, /* # of pages paged in */
97 MEM_CGROUP_EVENTS_PGPGOUT
, /* # of pages paged out */
98 MEM_CGROUP_EVENTS_COUNT
, /* # of pages paged in/out */
99 MEM_CGROUP_EVENTS_PGFAULT
, /* # of page-faults */
100 MEM_CGROUP_EVENTS_PGMAJFAULT
, /* # of major page-faults */
101 MEM_CGROUP_EVENTS_NSTATS
,
104 * Per memcg event counter is incremented at every pagein/pageout. With THP,
105 * it will be incremated by the number of pages. This counter is used for
106 * for trigger some periodic events. This is straightforward and better
107 * than using jiffies etc. to handle periodic memcg event.
109 enum mem_cgroup_events_target
{
110 MEM_CGROUP_TARGET_THRESH
,
111 MEM_CGROUP_TARGET_SOFTLIMIT
,
112 MEM_CGROUP_TARGET_NUMAINFO
,
115 #define THRESHOLDS_EVENTS_TARGET 128
116 #define SOFTLIMIT_EVENTS_TARGET 1024
117 #define NUMAINFO_EVENTS_TARGET 1024
119 struct mem_cgroup_stat_cpu
{
120 long count
[MEM_CGROUP_STAT_NSTATS
];
121 unsigned long events
[MEM_CGROUP_EVENTS_NSTATS
];
122 unsigned long targets
[MEM_CGROUP_NTARGETS
];
125 struct mem_cgroup_reclaim_iter
{
126 /* css_id of the last scanned hierarchy member */
128 /* scan generation, increased every round-trip */
129 unsigned int generation
;
133 * per-zone information in memory controller.
135 struct mem_cgroup_per_zone
{
136 struct lruvec lruvec
;
137 unsigned long lru_size
[NR_LRU_LISTS
];
139 struct mem_cgroup_reclaim_iter reclaim_iter
[DEF_PRIORITY
+ 1];
141 struct rb_node tree_node
; /* RB tree node */
142 unsigned long long usage_in_excess
;/* Set to the value by which */
143 /* the soft limit is exceeded*/
145 struct mem_cgroup
*memcg
; /* Back pointer, we cannot */
146 /* use container_of */
149 struct mem_cgroup_per_node
{
150 struct mem_cgroup_per_zone zoneinfo
[MAX_NR_ZONES
];
153 struct mem_cgroup_lru_info
{
154 struct mem_cgroup_per_node
*nodeinfo
[MAX_NUMNODES
];
158 * Cgroups above their limits are maintained in a RB-Tree, independent of
159 * their hierarchy representation
162 struct mem_cgroup_tree_per_zone
{
163 struct rb_root rb_root
;
167 struct mem_cgroup_tree_per_node
{
168 struct mem_cgroup_tree_per_zone rb_tree_per_zone
[MAX_NR_ZONES
];
171 struct mem_cgroup_tree
{
172 struct mem_cgroup_tree_per_node
*rb_tree_per_node
[MAX_NUMNODES
];
175 static struct mem_cgroup_tree soft_limit_tree __read_mostly
;
177 struct mem_cgroup_threshold
{
178 struct eventfd_ctx
*eventfd
;
183 struct mem_cgroup_threshold_ary
{
184 /* An array index points to threshold just below or equal to usage. */
185 int current_threshold
;
186 /* Size of entries[] */
188 /* Array of thresholds */
189 struct mem_cgroup_threshold entries
[0];
192 struct mem_cgroup_thresholds
{
193 /* Primary thresholds array */
194 struct mem_cgroup_threshold_ary
*primary
;
196 * Spare threshold array.
197 * This is needed to make mem_cgroup_unregister_event() "never fail".
198 * It must be able to store at least primary->size - 1 entries.
200 struct mem_cgroup_threshold_ary
*spare
;
204 struct mem_cgroup_eventfd_list
{
205 struct list_head list
;
206 struct eventfd_ctx
*eventfd
;
209 static void mem_cgroup_threshold(struct mem_cgroup
*memcg
);
210 static void mem_cgroup_oom_notify(struct mem_cgroup
*memcg
);
213 * The memory controller data structure. The memory controller controls both
214 * page cache and RSS per cgroup. We would eventually like to provide
215 * statistics based on the statistics developed by Rik Van Riel for clock-pro,
216 * to help the administrator determine what knobs to tune.
218 * TODO: Add a water mark for the memory controller. Reclaim will begin when
219 * we hit the water mark. May be even add a low water mark, such that
220 * no reclaim occurs from a cgroup at it's low water mark, this is
221 * a feature that will be implemented much later in the future.
224 struct cgroup_subsys_state css
;
226 * the counter to account for memory usage
228 struct res_counter res
;
232 * the counter to account for mem+swap usage.
234 struct res_counter memsw
;
237 * rcu_freeing is used only when freeing struct mem_cgroup,
238 * so put it into a union to avoid wasting more memory.
239 * It must be disjoint from the css field. It could be
240 * in a union with the res field, but res plays a much
241 * larger part in mem_cgroup life than memsw, and might
242 * be of interest, even at time of free, when debugging.
243 * So share rcu_head with the less interesting memsw.
245 struct rcu_head rcu_freeing
;
247 * But when using vfree(), that cannot be done at
248 * interrupt time, so we must then queue the work.
250 struct work_struct work_freeing
;
254 * Per cgroup active and inactive list, similar to the
255 * per zone LRU lists.
257 struct mem_cgroup_lru_info info
;
258 int last_scanned_node
;
260 nodemask_t scan_nodes
;
261 atomic_t numainfo_events
;
262 atomic_t numainfo_updating
;
265 * Should the accounting and control be hierarchical, per subtree?
275 /* OOM-Killer disable */
276 int oom_kill_disable
;
278 /* set when res.limit == memsw.limit */
279 bool memsw_is_minimum
;
281 /* protect arrays of thresholds */
282 struct mutex thresholds_lock
;
284 /* thresholds for memory usage. RCU-protected */
285 struct mem_cgroup_thresholds thresholds
;
287 /* thresholds for mem+swap usage. RCU-protected */
288 struct mem_cgroup_thresholds memsw_thresholds
;
290 /* For oom notifier event fd */
291 struct list_head oom_notify
;
294 * Should we move charges of a task when a task is moved into this
295 * mem_cgroup ? And what type of charges should we move ?
297 unsigned long move_charge_at_immigrate
;
299 * set > 0 if pages under this cgroup are moving to other cgroup.
301 atomic_t moving_account
;
302 /* taken only while moving_account > 0 */
303 spinlock_t move_lock
;
307 struct mem_cgroup_stat_cpu __percpu
*stat
;
309 * used when a cpu is offlined or other synchronizations
310 * See mem_cgroup_read_stat().
312 struct mem_cgroup_stat_cpu nocpu_base
;
313 spinlock_t pcp_counter_lock
;
316 struct tcp_memcontrol tcp_mem
;
320 /* Stuffs for move charges at task migration. */
322 * Types of charges to be moved. "move_charge_at_immitgrate" is treated as a
323 * left-shifted bitmap of these types.
326 MOVE_CHARGE_TYPE_ANON
, /* private anonymous page and swap of it */
327 MOVE_CHARGE_TYPE_FILE
, /* file page(including tmpfs) and swap of it */
331 /* "mc" and its members are protected by cgroup_mutex */
332 static struct move_charge_struct
{
333 spinlock_t lock
; /* for from, to */
334 struct mem_cgroup
*from
;
335 struct mem_cgroup
*to
;
336 unsigned long precharge
;
337 unsigned long moved_charge
;
338 unsigned long moved_swap
;
339 struct task_struct
*moving_task
; /* a task moving charges */
340 wait_queue_head_t waitq
; /* a waitq for other context */
342 .lock
= __SPIN_LOCK_UNLOCKED(mc
.lock
),
343 .waitq
= __WAIT_QUEUE_HEAD_INITIALIZER(mc
.waitq
),
346 static bool move_anon(void)
348 return test_bit(MOVE_CHARGE_TYPE_ANON
,
349 &mc
.to
->move_charge_at_immigrate
);
352 static bool move_file(void)
354 return test_bit(MOVE_CHARGE_TYPE_FILE
,
355 &mc
.to
->move_charge_at_immigrate
);
359 * Maximum loops in mem_cgroup_hierarchical_reclaim(), used for soft
360 * limit reclaim to prevent infinite loops, if they ever occur.
362 #define MEM_CGROUP_MAX_RECLAIM_LOOPS 100
363 #define MEM_CGROUP_MAX_SOFT_LIMIT_RECLAIM_LOOPS 2
366 MEM_CGROUP_CHARGE_TYPE_CACHE
= 0,
367 MEM_CGROUP_CHARGE_TYPE_MAPPED
,
368 MEM_CGROUP_CHARGE_TYPE_SHMEM
, /* used by page migration of shmem */
369 MEM_CGROUP_CHARGE_TYPE_FORCE
, /* used by force_empty */
370 MEM_CGROUP_CHARGE_TYPE_SWAPOUT
, /* for accounting swapcache */
371 MEM_CGROUP_CHARGE_TYPE_DROP
, /* a page was unused swap cache */
375 /* for encoding cft->private value on file */
378 #define _OOM_TYPE (2)
379 #define MEMFILE_PRIVATE(x, val) ((x) << 16 | (val))
380 #define MEMFILE_TYPE(val) ((val) >> 16 & 0xffff)
381 #define MEMFILE_ATTR(val) ((val) & 0xffff)
382 /* Used for OOM nofiier */
383 #define OOM_CONTROL (0)
386 * Reclaim flags for mem_cgroup_hierarchical_reclaim
388 #define MEM_CGROUP_RECLAIM_NOSWAP_BIT 0x0
389 #define MEM_CGROUP_RECLAIM_NOSWAP (1 << MEM_CGROUP_RECLAIM_NOSWAP_BIT)
390 #define MEM_CGROUP_RECLAIM_SHRINK_BIT 0x1
391 #define MEM_CGROUP_RECLAIM_SHRINK (1 << MEM_CGROUP_RECLAIM_SHRINK_BIT)
393 static void mem_cgroup_get(struct mem_cgroup
*memcg
);
394 static void mem_cgroup_put(struct mem_cgroup
*memcg
);
396 /* Writing them here to avoid exposing memcg's inner layout */
397 #ifdef CONFIG_CGROUP_MEM_RES_CTLR_KMEM
398 #include <net/sock.h>
401 static bool mem_cgroup_is_root(struct mem_cgroup
*memcg
);
402 void sock_update_memcg(struct sock
*sk
)
404 if (mem_cgroup_sockets_enabled
) {
405 struct mem_cgroup
*memcg
;
407 BUG_ON(!sk
->sk_prot
->proto_cgroup
);
409 /* Socket cloning can throw us here with sk_cgrp already
410 * filled. It won't however, necessarily happen from
411 * process context. So the test for root memcg given
412 * the current task's memcg won't help us in this case.
414 * Respecting the original socket's memcg is a better
415 * decision in this case.
418 BUG_ON(mem_cgroup_is_root(sk
->sk_cgrp
->memcg
));
419 mem_cgroup_get(sk
->sk_cgrp
->memcg
);
424 memcg
= mem_cgroup_from_task(current
);
425 if (!mem_cgroup_is_root(memcg
)) {
426 mem_cgroup_get(memcg
);
427 sk
->sk_cgrp
= sk
->sk_prot
->proto_cgroup(memcg
);
432 EXPORT_SYMBOL(sock_update_memcg
);
434 void sock_release_memcg(struct sock
*sk
)
436 if (mem_cgroup_sockets_enabled
&& sk
->sk_cgrp
) {
437 struct mem_cgroup
*memcg
;
438 WARN_ON(!sk
->sk_cgrp
->memcg
);
439 memcg
= sk
->sk_cgrp
->memcg
;
440 mem_cgroup_put(memcg
);
445 struct cg_proto
*tcp_proto_cgroup(struct mem_cgroup
*memcg
)
447 if (!memcg
|| mem_cgroup_is_root(memcg
))
450 return &memcg
->tcp_mem
.cg_proto
;
452 EXPORT_SYMBOL(tcp_proto_cgroup
);
453 #endif /* CONFIG_INET */
454 #endif /* CONFIG_CGROUP_MEM_RES_CTLR_KMEM */
456 static void drain_all_stock_async(struct mem_cgroup
*memcg
);
458 static struct mem_cgroup_per_zone
*
459 mem_cgroup_zoneinfo(struct mem_cgroup
*memcg
, int nid
, int zid
)
461 return &memcg
->info
.nodeinfo
[nid
]->zoneinfo
[zid
];
464 struct cgroup_subsys_state
*mem_cgroup_css(struct mem_cgroup
*memcg
)
469 static struct mem_cgroup_per_zone
*
470 page_cgroup_zoneinfo(struct mem_cgroup
*memcg
, struct page
*page
)
472 int nid
= page_to_nid(page
);
473 int zid
= page_zonenum(page
);
475 return mem_cgroup_zoneinfo(memcg
, nid
, zid
);
478 static struct mem_cgroup_tree_per_zone
*
479 soft_limit_tree_node_zone(int nid
, int zid
)
481 return &soft_limit_tree
.rb_tree_per_node
[nid
]->rb_tree_per_zone
[zid
];
484 static struct mem_cgroup_tree_per_zone
*
485 soft_limit_tree_from_page(struct page
*page
)
487 int nid
= page_to_nid(page
);
488 int zid
= page_zonenum(page
);
490 return &soft_limit_tree
.rb_tree_per_node
[nid
]->rb_tree_per_zone
[zid
];
494 __mem_cgroup_insert_exceeded(struct mem_cgroup
*memcg
,
495 struct mem_cgroup_per_zone
*mz
,
496 struct mem_cgroup_tree_per_zone
*mctz
,
497 unsigned long long new_usage_in_excess
)
499 struct rb_node
**p
= &mctz
->rb_root
.rb_node
;
500 struct rb_node
*parent
= NULL
;
501 struct mem_cgroup_per_zone
*mz_node
;
506 mz
->usage_in_excess
= new_usage_in_excess
;
507 if (!mz
->usage_in_excess
)
511 mz_node
= rb_entry(parent
, struct mem_cgroup_per_zone
,
513 if (mz
->usage_in_excess
< mz_node
->usage_in_excess
)
516 * We can't avoid mem cgroups that are over their soft
517 * limit by the same amount
519 else if (mz
->usage_in_excess
>= mz_node
->usage_in_excess
)
522 rb_link_node(&mz
->tree_node
, parent
, p
);
523 rb_insert_color(&mz
->tree_node
, &mctz
->rb_root
);
528 __mem_cgroup_remove_exceeded(struct mem_cgroup
*memcg
,
529 struct mem_cgroup_per_zone
*mz
,
530 struct mem_cgroup_tree_per_zone
*mctz
)
534 rb_erase(&mz
->tree_node
, &mctz
->rb_root
);
539 mem_cgroup_remove_exceeded(struct mem_cgroup
*memcg
,
540 struct mem_cgroup_per_zone
*mz
,
541 struct mem_cgroup_tree_per_zone
*mctz
)
543 spin_lock(&mctz
->lock
);
544 __mem_cgroup_remove_exceeded(memcg
, mz
, mctz
);
545 spin_unlock(&mctz
->lock
);
549 static void mem_cgroup_update_tree(struct mem_cgroup
*memcg
, struct page
*page
)
551 unsigned long long excess
;
552 struct mem_cgroup_per_zone
*mz
;
553 struct mem_cgroup_tree_per_zone
*mctz
;
554 int nid
= page_to_nid(page
);
555 int zid
= page_zonenum(page
);
556 mctz
= soft_limit_tree_from_page(page
);
559 * Necessary to update all ancestors when hierarchy is used.
560 * because their event counter is not touched.
562 for (; memcg
; memcg
= parent_mem_cgroup(memcg
)) {
563 mz
= mem_cgroup_zoneinfo(memcg
, nid
, zid
);
564 excess
= res_counter_soft_limit_excess(&memcg
->res
);
566 * We have to update the tree if mz is on RB-tree or
567 * mem is over its softlimit.
569 if (excess
|| mz
->on_tree
) {
570 spin_lock(&mctz
->lock
);
571 /* if on-tree, remove it */
573 __mem_cgroup_remove_exceeded(memcg
, mz
, mctz
);
575 * Insert again. mz->usage_in_excess will be updated.
576 * If excess is 0, no tree ops.
578 __mem_cgroup_insert_exceeded(memcg
, mz
, mctz
, excess
);
579 spin_unlock(&mctz
->lock
);
584 static void mem_cgroup_remove_from_trees(struct mem_cgroup
*memcg
)
587 struct mem_cgroup_per_zone
*mz
;
588 struct mem_cgroup_tree_per_zone
*mctz
;
590 for_each_node(node
) {
591 for (zone
= 0; zone
< MAX_NR_ZONES
; zone
++) {
592 mz
= mem_cgroup_zoneinfo(memcg
, node
, zone
);
593 mctz
= soft_limit_tree_node_zone(node
, zone
);
594 mem_cgroup_remove_exceeded(memcg
, mz
, mctz
);
599 static struct mem_cgroup_per_zone
*
600 __mem_cgroup_largest_soft_limit_node(struct mem_cgroup_tree_per_zone
*mctz
)
602 struct rb_node
*rightmost
= NULL
;
603 struct mem_cgroup_per_zone
*mz
;
607 rightmost
= rb_last(&mctz
->rb_root
);
609 goto done
; /* Nothing to reclaim from */
611 mz
= rb_entry(rightmost
, struct mem_cgroup_per_zone
, tree_node
);
613 * Remove the node now but someone else can add it back,
614 * we will to add it back at the end of reclaim to its correct
615 * position in the tree.
617 __mem_cgroup_remove_exceeded(mz
->memcg
, mz
, mctz
);
618 if (!res_counter_soft_limit_excess(&mz
->memcg
->res
) ||
619 !css_tryget(&mz
->memcg
->css
))
625 static struct mem_cgroup_per_zone
*
626 mem_cgroup_largest_soft_limit_node(struct mem_cgroup_tree_per_zone
*mctz
)
628 struct mem_cgroup_per_zone
*mz
;
630 spin_lock(&mctz
->lock
);
631 mz
= __mem_cgroup_largest_soft_limit_node(mctz
);
632 spin_unlock(&mctz
->lock
);
637 * Implementation Note: reading percpu statistics for memcg.
639 * Both of vmstat[] and percpu_counter has threshold and do periodic
640 * synchronization to implement "quick" read. There are trade-off between
641 * reading cost and precision of value. Then, we may have a chance to implement
642 * a periodic synchronizion of counter in memcg's counter.
644 * But this _read() function is used for user interface now. The user accounts
645 * memory usage by memory cgroup and he _always_ requires exact value because
646 * he accounts memory. Even if we provide quick-and-fuzzy read, we always
647 * have to visit all online cpus and make sum. So, for now, unnecessary
648 * synchronization is not implemented. (just implemented for cpu hotplug)
650 * If there are kernel internal actions which can make use of some not-exact
651 * value, and reading all cpu value can be performance bottleneck in some
652 * common workload, threashold and synchonization as vmstat[] should be
655 static long mem_cgroup_read_stat(struct mem_cgroup
*memcg
,
656 enum mem_cgroup_stat_index idx
)
662 for_each_online_cpu(cpu
)
663 val
+= per_cpu(memcg
->stat
->count
[idx
], cpu
);
664 #ifdef CONFIG_HOTPLUG_CPU
665 spin_lock(&memcg
->pcp_counter_lock
);
666 val
+= memcg
->nocpu_base
.count
[idx
];
667 spin_unlock(&memcg
->pcp_counter_lock
);
673 static void mem_cgroup_swap_statistics(struct mem_cgroup
*memcg
,
676 int val
= (charge
) ? 1 : -1;
677 this_cpu_add(memcg
->stat
->count
[MEM_CGROUP_STAT_SWAPOUT
], val
);
680 static unsigned long mem_cgroup_read_events(struct mem_cgroup
*memcg
,
681 enum mem_cgroup_events_index idx
)
683 unsigned long val
= 0;
686 for_each_online_cpu(cpu
)
687 val
+= per_cpu(memcg
->stat
->events
[idx
], cpu
);
688 #ifdef CONFIG_HOTPLUG_CPU
689 spin_lock(&memcg
->pcp_counter_lock
);
690 val
+= memcg
->nocpu_base
.events
[idx
];
691 spin_unlock(&memcg
->pcp_counter_lock
);
696 static void mem_cgroup_charge_statistics(struct mem_cgroup
*memcg
,
697 bool anon
, int nr_pages
)
702 * Here, RSS means 'mapped anon' and anon's SwapCache. Shmem/tmpfs is
703 * counted as CACHE even if it's on ANON LRU.
706 __this_cpu_add(memcg
->stat
->count
[MEM_CGROUP_STAT_RSS
],
709 __this_cpu_add(memcg
->stat
->count
[MEM_CGROUP_STAT_CACHE
],
712 /* pagein of a big page is an event. So, ignore page size */
714 __this_cpu_inc(memcg
->stat
->events
[MEM_CGROUP_EVENTS_PGPGIN
]);
716 __this_cpu_inc(memcg
->stat
->events
[MEM_CGROUP_EVENTS_PGPGOUT
]);
717 nr_pages
= -nr_pages
; /* for event */
720 __this_cpu_add(memcg
->stat
->events
[MEM_CGROUP_EVENTS_COUNT
], nr_pages
);
726 mem_cgroup_get_lruvec_size(struct lruvec
*lruvec
, enum lru_list lru
)
728 struct mem_cgroup_per_zone
*mz
;
730 mz
= container_of(lruvec
, struct mem_cgroup_per_zone
, lruvec
);
731 return mz
->lru_size
[lru
];
735 mem_cgroup_zone_nr_lru_pages(struct mem_cgroup
*memcg
, int nid
, int zid
,
736 unsigned int lru_mask
)
738 struct mem_cgroup_per_zone
*mz
;
740 unsigned long ret
= 0;
742 mz
= mem_cgroup_zoneinfo(memcg
, nid
, zid
);
745 if (BIT(lru
) & lru_mask
)
746 ret
+= mz
->lru_size
[lru
];
752 mem_cgroup_node_nr_lru_pages(struct mem_cgroup
*memcg
,
753 int nid
, unsigned int lru_mask
)
758 for (zid
= 0; zid
< MAX_NR_ZONES
; zid
++)
759 total
+= mem_cgroup_zone_nr_lru_pages(memcg
,
765 static unsigned long mem_cgroup_nr_lru_pages(struct mem_cgroup
*memcg
,
766 unsigned int lru_mask
)
771 for_each_node_state(nid
, N_HIGH_MEMORY
)
772 total
+= mem_cgroup_node_nr_lru_pages(memcg
, nid
, lru_mask
);
776 static bool mem_cgroup_event_ratelimit(struct mem_cgroup
*memcg
,
777 enum mem_cgroup_events_target target
)
779 unsigned long val
, next
;
781 val
= __this_cpu_read(memcg
->stat
->events
[MEM_CGROUP_EVENTS_COUNT
]);
782 next
= __this_cpu_read(memcg
->stat
->targets
[target
]);
783 /* from time_after() in jiffies.h */
784 if ((long)next
- (long)val
< 0) {
786 case MEM_CGROUP_TARGET_THRESH
:
787 next
= val
+ THRESHOLDS_EVENTS_TARGET
;
789 case MEM_CGROUP_TARGET_SOFTLIMIT
:
790 next
= val
+ SOFTLIMIT_EVENTS_TARGET
;
792 case MEM_CGROUP_TARGET_NUMAINFO
:
793 next
= val
+ NUMAINFO_EVENTS_TARGET
;
798 __this_cpu_write(memcg
->stat
->targets
[target
], next
);
805 * Check events in order.
808 static void memcg_check_events(struct mem_cgroup
*memcg
, struct page
*page
)
811 /* threshold event is triggered in finer grain than soft limit */
812 if (unlikely(mem_cgroup_event_ratelimit(memcg
,
813 MEM_CGROUP_TARGET_THRESH
))) {
815 bool do_numainfo __maybe_unused
;
817 do_softlimit
= mem_cgroup_event_ratelimit(memcg
,
818 MEM_CGROUP_TARGET_SOFTLIMIT
);
820 do_numainfo
= mem_cgroup_event_ratelimit(memcg
,
821 MEM_CGROUP_TARGET_NUMAINFO
);
825 mem_cgroup_threshold(memcg
);
826 if (unlikely(do_softlimit
))
827 mem_cgroup_update_tree(memcg
, page
);
829 if (unlikely(do_numainfo
))
830 atomic_inc(&memcg
->numainfo_events
);
836 struct mem_cgroup
*mem_cgroup_from_cont(struct cgroup
*cont
)
838 return container_of(cgroup_subsys_state(cont
,
839 mem_cgroup_subsys_id
), struct mem_cgroup
,
843 struct mem_cgroup
*mem_cgroup_from_task(struct task_struct
*p
)
846 * mm_update_next_owner() may clear mm->owner to NULL
847 * if it races with swapoff, page migration, etc.
848 * So this can be called with p == NULL.
853 return container_of(task_subsys_state(p
, mem_cgroup_subsys_id
),
854 struct mem_cgroup
, css
);
857 struct mem_cgroup
*try_get_mem_cgroup_from_mm(struct mm_struct
*mm
)
859 struct mem_cgroup
*memcg
= NULL
;
864 * Because we have no locks, mm->owner's may be being moved to other
865 * cgroup. We use css_tryget() here even if this looks
866 * pessimistic (rather than adding locks here).
870 memcg
= mem_cgroup_from_task(rcu_dereference(mm
->owner
));
871 if (unlikely(!memcg
))
873 } while (!css_tryget(&memcg
->css
));
879 * mem_cgroup_iter - iterate over memory cgroup hierarchy
880 * @root: hierarchy root
881 * @prev: previously returned memcg, NULL on first invocation
882 * @reclaim: cookie for shared reclaim walks, NULL for full walks
884 * Returns references to children of the hierarchy below @root, or
885 * @root itself, or %NULL after a full round-trip.
887 * Caller must pass the return value in @prev on subsequent
888 * invocations for reference counting, or use mem_cgroup_iter_break()
889 * to cancel a hierarchy walk before the round-trip is complete.
891 * Reclaimers can specify a zone and a priority level in @reclaim to
892 * divide up the memcgs in the hierarchy among all concurrent
893 * reclaimers operating on the same zone and priority.
895 struct mem_cgroup
*mem_cgroup_iter(struct mem_cgroup
*root
,
896 struct mem_cgroup
*prev
,
897 struct mem_cgroup_reclaim_cookie
*reclaim
)
899 struct mem_cgroup
*memcg
= NULL
;
902 if (mem_cgroup_disabled())
906 root
= root_mem_cgroup
;
908 if (prev
&& !reclaim
)
909 id
= css_id(&prev
->css
);
911 if (prev
&& prev
!= root
)
914 if (!root
->use_hierarchy
&& root
!= root_mem_cgroup
) {
921 struct mem_cgroup_reclaim_iter
*uninitialized_var(iter
);
922 struct cgroup_subsys_state
*css
;
925 int nid
= zone_to_nid(reclaim
->zone
);
926 int zid
= zone_idx(reclaim
->zone
);
927 struct mem_cgroup_per_zone
*mz
;
929 mz
= mem_cgroup_zoneinfo(root
, nid
, zid
);
930 iter
= &mz
->reclaim_iter
[reclaim
->priority
];
931 if (prev
&& reclaim
->generation
!= iter
->generation
)
937 css
= css_get_next(&mem_cgroup_subsys
, id
+ 1, &root
->css
, &id
);
939 if (css
== &root
->css
|| css_tryget(css
))
940 memcg
= container_of(css
,
941 struct mem_cgroup
, css
);
950 else if (!prev
&& memcg
)
951 reclaim
->generation
= iter
->generation
;
961 * mem_cgroup_iter_break - abort a hierarchy walk prematurely
962 * @root: hierarchy root
963 * @prev: last visited hierarchy member as returned by mem_cgroup_iter()
965 void mem_cgroup_iter_break(struct mem_cgroup
*root
,
966 struct mem_cgroup
*prev
)
969 root
= root_mem_cgroup
;
970 if (prev
&& prev
!= root
)
975 * Iteration constructs for visiting all cgroups (under a tree). If
976 * loops are exited prematurely (break), mem_cgroup_iter_break() must
977 * be used for reference counting.
979 #define for_each_mem_cgroup_tree(iter, root) \
980 for (iter = mem_cgroup_iter(root, NULL, NULL); \
982 iter = mem_cgroup_iter(root, iter, NULL))
984 #define for_each_mem_cgroup(iter) \
985 for (iter = mem_cgroup_iter(NULL, NULL, NULL); \
987 iter = mem_cgroup_iter(NULL, iter, NULL))
989 static inline bool mem_cgroup_is_root(struct mem_cgroup
*memcg
)
991 return (memcg
== root_mem_cgroup
);
994 void mem_cgroup_count_vm_event(struct mm_struct
*mm
, enum vm_event_item idx
)
996 struct mem_cgroup
*memcg
;
1002 memcg
= mem_cgroup_from_task(rcu_dereference(mm
->owner
));
1003 if (unlikely(!memcg
))
1008 this_cpu_inc(memcg
->stat
->events
[MEM_CGROUP_EVENTS_PGFAULT
]);
1011 this_cpu_inc(memcg
->stat
->events
[MEM_CGROUP_EVENTS_PGMAJFAULT
]);
1019 EXPORT_SYMBOL(mem_cgroup_count_vm_event
);
1022 * mem_cgroup_zone_lruvec - get the lru list vector for a zone and memcg
1023 * @zone: zone of the wanted lruvec
1024 * @mem: memcg of the wanted lruvec
1026 * Returns the lru list vector holding pages for the given @zone and
1027 * @mem. This can be the global zone lruvec, if the memory controller
1030 struct lruvec
*mem_cgroup_zone_lruvec(struct zone
*zone
,
1031 struct mem_cgroup
*memcg
)
1033 struct mem_cgroup_per_zone
*mz
;
1035 if (mem_cgroup_disabled())
1036 return &zone
->lruvec
;
1038 mz
= mem_cgroup_zoneinfo(memcg
, zone_to_nid(zone
), zone_idx(zone
));
1043 * Following LRU functions are allowed to be used without PCG_LOCK.
1044 * Operations are called by routine of global LRU independently from memcg.
1045 * What we have to take care of here is validness of pc->mem_cgroup.
1047 * Changes to pc->mem_cgroup happens when
1050 * In typical case, "charge" is done before add-to-lru. Exception is SwapCache.
1051 * It is added to LRU before charge.
1052 * If PCG_USED bit is not set, page_cgroup is not added to this private LRU.
1053 * When moving account, the page is not on LRU. It's isolated.
1057 * mem_cgroup_lru_add_list - account for adding an lru page and return lruvec
1058 * @zone: zone of the page
1062 * This function accounts for @page being added to @lru, and returns
1063 * the lruvec for the given @zone and the memcg @page is charged to.
1065 * The callsite is then responsible for physically linking the page to
1066 * the returned lruvec->lists[@lru].
1068 struct lruvec
*mem_cgroup_lru_add_list(struct zone
*zone
, struct page
*page
,
1071 struct mem_cgroup_per_zone
*mz
;
1072 struct mem_cgroup
*memcg
;
1073 struct page_cgroup
*pc
;
1075 if (mem_cgroup_disabled())
1076 return &zone
->lruvec
;
1078 pc
= lookup_page_cgroup(page
);
1079 memcg
= pc
->mem_cgroup
;
1082 * Surreptitiously switch any uncharged page to root:
1083 * an uncharged page off lru does nothing to secure
1084 * its former mem_cgroup from sudden removal.
1086 * Our caller holds lru_lock, and PageCgroupUsed is updated
1087 * under page_cgroup lock: between them, they make all uses
1088 * of pc->mem_cgroup safe.
1090 if (!PageCgroupUsed(pc
) && memcg
!= root_mem_cgroup
)
1091 pc
->mem_cgroup
= memcg
= root_mem_cgroup
;
1093 mz
= page_cgroup_zoneinfo(memcg
, page
);
1094 /* compound_order() is stabilized through lru_lock */
1095 mz
->lru_size
[lru
] += 1 << compound_order(page
);
1100 * mem_cgroup_lru_del_list - account for removing an lru page
1104 * This function accounts for @page being removed from @lru.
1106 * The callsite is then responsible for physically unlinking
1109 void mem_cgroup_lru_del_list(struct page
*page
, enum lru_list lru
)
1111 struct mem_cgroup_per_zone
*mz
;
1112 struct mem_cgroup
*memcg
;
1113 struct page_cgroup
*pc
;
1115 if (mem_cgroup_disabled())
1118 pc
= lookup_page_cgroup(page
);
1119 memcg
= pc
->mem_cgroup
;
1121 mz
= page_cgroup_zoneinfo(memcg
, page
);
1122 /* huge page split is done under lru_lock. so, we have no races. */
1123 VM_BUG_ON(mz
->lru_size
[lru
] < (1 << compound_order(page
)));
1124 mz
->lru_size
[lru
] -= 1 << compound_order(page
);
1128 * mem_cgroup_lru_move_lists - account for moving a page between lrus
1129 * @zone: zone of the page
1131 * @from: current lru
1134 * This function accounts for @page being moved between the lrus @from
1135 * and @to, and returns the lruvec for the given @zone and the memcg
1136 * @page is charged to.
1138 * The callsite is then responsible for physically relinking
1139 * @page->lru to the returned lruvec->lists[@to].
1141 struct lruvec
*mem_cgroup_lru_move_lists(struct zone
*zone
,
1146 /* XXX: Optimize this, especially for @from == @to */
1147 mem_cgroup_lru_del_list(page
, from
);
1148 return mem_cgroup_lru_add_list(zone
, page
, to
);
1152 * Checks whether given mem is same or in the root_mem_cgroup's
1155 bool __mem_cgroup_same_or_subtree(const struct mem_cgroup
*root_memcg
,
1156 struct mem_cgroup
*memcg
)
1158 if (root_memcg
== memcg
)
1160 if (!root_memcg
->use_hierarchy
)
1162 return css_is_ancestor(&memcg
->css
, &root_memcg
->css
);
1165 static bool mem_cgroup_same_or_subtree(const struct mem_cgroup
*root_memcg
,
1166 struct mem_cgroup
*memcg
)
1171 ret
= __mem_cgroup_same_or_subtree(root_memcg
, memcg
);
1176 int task_in_mem_cgroup(struct task_struct
*task
, const struct mem_cgroup
*memcg
)
1179 struct mem_cgroup
*curr
= NULL
;
1180 struct task_struct
*p
;
1182 p
= find_lock_task_mm(task
);
1184 curr
= try_get_mem_cgroup_from_mm(p
->mm
);
1188 * All threads may have already detached their mm's, but the oom
1189 * killer still needs to detect if they have already been oom
1190 * killed to prevent needlessly killing additional tasks.
1193 curr
= mem_cgroup_from_task(task
);
1195 css_get(&curr
->css
);
1201 * We should check use_hierarchy of "memcg" not "curr". Because checking
1202 * use_hierarchy of "curr" here make this function true if hierarchy is
1203 * enabled in "curr" and "curr" is a child of "memcg" in *cgroup*
1204 * hierarchy(even if use_hierarchy is disabled in "memcg").
1206 ret
= mem_cgroup_same_or_subtree(memcg
, curr
);
1207 css_put(&curr
->css
);
1211 int mem_cgroup_inactive_anon_is_low(struct lruvec
*lruvec
)
1213 unsigned long inactive_ratio
;
1214 unsigned long inactive
;
1215 unsigned long active
;
1218 inactive
= mem_cgroup_get_lruvec_size(lruvec
, LRU_INACTIVE_ANON
);
1219 active
= mem_cgroup_get_lruvec_size(lruvec
, LRU_ACTIVE_ANON
);
1221 gb
= (inactive
+ active
) >> (30 - PAGE_SHIFT
);
1223 inactive_ratio
= int_sqrt(10 * gb
);
1227 return inactive
* inactive_ratio
< active
;
1230 int mem_cgroup_inactive_file_is_low(struct lruvec
*lruvec
)
1232 unsigned long active
;
1233 unsigned long inactive
;
1235 inactive
= mem_cgroup_get_lruvec_size(lruvec
, LRU_INACTIVE_FILE
);
1236 active
= mem_cgroup_get_lruvec_size(lruvec
, LRU_ACTIVE_FILE
);
1238 return (active
> inactive
);
1241 struct zone_reclaim_stat
*
1242 mem_cgroup_get_reclaim_stat_from_page(struct page
*page
)
1244 struct page_cgroup
*pc
;
1245 struct mem_cgroup_per_zone
*mz
;
1247 if (mem_cgroup_disabled())
1250 pc
= lookup_page_cgroup(page
);
1251 if (!PageCgroupUsed(pc
))
1253 /* Ensure pc->mem_cgroup is visible after reading PCG_USED. */
1255 mz
= page_cgroup_zoneinfo(pc
->mem_cgroup
, page
);
1256 return &mz
->lruvec
.reclaim_stat
;
1259 #define mem_cgroup_from_res_counter(counter, member) \
1260 container_of(counter, struct mem_cgroup, member)
1263 * mem_cgroup_margin - calculate chargeable space of a memory cgroup
1264 * @mem: the memory cgroup
1266 * Returns the maximum amount of memory @mem can be charged with, in
1269 static unsigned long mem_cgroup_margin(struct mem_cgroup
*memcg
)
1271 unsigned long long margin
;
1273 margin
= res_counter_margin(&memcg
->res
);
1274 if (do_swap_account
)
1275 margin
= min(margin
, res_counter_margin(&memcg
->memsw
));
1276 return margin
>> PAGE_SHIFT
;
1279 int mem_cgroup_swappiness(struct mem_cgroup
*memcg
)
1281 struct cgroup
*cgrp
= memcg
->css
.cgroup
;
1284 if (cgrp
->parent
== NULL
)
1285 return vm_swappiness
;
1287 return memcg
->swappiness
;
1291 * memcg->moving_account is used for checking possibility that some thread is
1292 * calling move_account(). When a thread on CPU-A starts moving pages under
1293 * a memcg, other threads should check memcg->moving_account under
1294 * rcu_read_lock(), like this:
1298 * memcg->moving_account+1 if (memcg->mocing_account)
1300 * synchronize_rcu() update something.
1305 /* for quick checking without looking up memcg */
1306 atomic_t memcg_moving __read_mostly
;
1308 static void mem_cgroup_start_move(struct mem_cgroup
*memcg
)
1310 atomic_inc(&memcg_moving
);
1311 atomic_inc(&memcg
->moving_account
);
1315 static void mem_cgroup_end_move(struct mem_cgroup
*memcg
)
1318 * Now, mem_cgroup_clear_mc() may call this function with NULL.
1319 * We check NULL in callee rather than caller.
1322 atomic_dec(&memcg_moving
);
1323 atomic_dec(&memcg
->moving_account
);
1328 * 2 routines for checking "mem" is under move_account() or not.
1330 * mem_cgroup_stolen() - checking whether a cgroup is mc.from or not. This
1331 * is used for avoiding races in accounting. If true,
1332 * pc->mem_cgroup may be overwritten.
1334 * mem_cgroup_under_move() - checking a cgroup is mc.from or mc.to or
1335 * under hierarchy of moving cgroups. This is for
1336 * waiting at hith-memory prressure caused by "move".
1339 static bool mem_cgroup_stolen(struct mem_cgroup
*memcg
)
1341 VM_BUG_ON(!rcu_read_lock_held());
1342 return atomic_read(&memcg
->moving_account
) > 0;
1345 static bool mem_cgroup_under_move(struct mem_cgroup
*memcg
)
1347 struct mem_cgroup
*from
;
1348 struct mem_cgroup
*to
;
1351 * Unlike task_move routines, we access mc.to, mc.from not under
1352 * mutual exclusion by cgroup_mutex. Here, we take spinlock instead.
1354 spin_lock(&mc
.lock
);
1360 ret
= mem_cgroup_same_or_subtree(memcg
, from
)
1361 || mem_cgroup_same_or_subtree(memcg
, to
);
1363 spin_unlock(&mc
.lock
);
1367 static bool mem_cgroup_wait_acct_move(struct mem_cgroup
*memcg
)
1369 if (mc
.moving_task
&& current
!= mc
.moving_task
) {
1370 if (mem_cgroup_under_move(memcg
)) {
1372 prepare_to_wait(&mc
.waitq
, &wait
, TASK_INTERRUPTIBLE
);
1373 /* moving charge context might have finished. */
1376 finish_wait(&mc
.waitq
, &wait
);
1384 * Take this lock when
1385 * - a code tries to modify page's memcg while it's USED.
1386 * - a code tries to modify page state accounting in a memcg.
1387 * see mem_cgroup_stolen(), too.
1389 static void move_lock_mem_cgroup(struct mem_cgroup
*memcg
,
1390 unsigned long *flags
)
1392 spin_lock_irqsave(&memcg
->move_lock
, *flags
);
1395 static void move_unlock_mem_cgroup(struct mem_cgroup
*memcg
,
1396 unsigned long *flags
)
1398 spin_unlock_irqrestore(&memcg
->move_lock
, *flags
);
1402 * mem_cgroup_print_oom_info: Called from OOM with tasklist_lock held in read mode.
1403 * @memcg: The memory cgroup that went over limit
1404 * @p: Task that is going to be killed
1406 * NOTE: @memcg and @p's mem_cgroup can be different when hierarchy is
1409 void mem_cgroup_print_oom_info(struct mem_cgroup
*memcg
, struct task_struct
*p
)
1411 struct cgroup
*task_cgrp
;
1412 struct cgroup
*mem_cgrp
;
1414 * Need a buffer in BSS, can't rely on allocations. The code relies
1415 * on the assumption that OOM is serialized for memory controller.
1416 * If this assumption is broken, revisit this code.
1418 static char memcg_name
[PATH_MAX
];
1426 mem_cgrp
= memcg
->css
.cgroup
;
1427 task_cgrp
= task_cgroup(p
, mem_cgroup_subsys_id
);
1429 ret
= cgroup_path(task_cgrp
, memcg_name
, PATH_MAX
);
1432 * Unfortunately, we are unable to convert to a useful name
1433 * But we'll still print out the usage information
1440 printk(KERN_INFO
"Task in %s killed", memcg_name
);
1443 ret
= cgroup_path(mem_cgrp
, memcg_name
, PATH_MAX
);
1451 * Continues from above, so we don't need an KERN_ level
1453 printk(KERN_CONT
" as a result of limit of %s\n", memcg_name
);
1456 printk(KERN_INFO
"memory: usage %llukB, limit %llukB, failcnt %llu\n",
1457 res_counter_read_u64(&memcg
->res
, RES_USAGE
) >> 10,
1458 res_counter_read_u64(&memcg
->res
, RES_LIMIT
) >> 10,
1459 res_counter_read_u64(&memcg
->res
, RES_FAILCNT
));
1460 printk(KERN_INFO
"memory+swap: usage %llukB, limit %llukB, "
1462 res_counter_read_u64(&memcg
->memsw
, RES_USAGE
) >> 10,
1463 res_counter_read_u64(&memcg
->memsw
, RES_LIMIT
) >> 10,
1464 res_counter_read_u64(&memcg
->memsw
, RES_FAILCNT
));
1468 * This function returns the number of memcg under hierarchy tree. Returns
1469 * 1(self count) if no children.
1471 static int mem_cgroup_count_children(struct mem_cgroup
*memcg
)
1474 struct mem_cgroup
*iter
;
1476 for_each_mem_cgroup_tree(iter
, memcg
)
1482 * Return the memory (and swap, if configured) limit for a memcg.
1484 u64
mem_cgroup_get_limit(struct mem_cgroup
*memcg
)
1489 limit
= res_counter_read_u64(&memcg
->res
, RES_LIMIT
);
1490 limit
+= total_swap_pages
<< PAGE_SHIFT
;
1492 memsw
= res_counter_read_u64(&memcg
->memsw
, RES_LIMIT
);
1494 * If memsw is finite and limits the amount of swap space available
1495 * to this memcg, return that limit.
1497 return min(limit
, memsw
);
1500 static unsigned long mem_cgroup_reclaim(struct mem_cgroup
*memcg
,
1502 unsigned long flags
)
1504 unsigned long total
= 0;
1505 bool noswap
= false;
1508 if (flags
& MEM_CGROUP_RECLAIM_NOSWAP
)
1510 if (!(flags
& MEM_CGROUP_RECLAIM_SHRINK
) && memcg
->memsw_is_minimum
)
1513 for (loop
= 0; loop
< MEM_CGROUP_MAX_RECLAIM_LOOPS
; loop
++) {
1515 drain_all_stock_async(memcg
);
1516 total
+= try_to_free_mem_cgroup_pages(memcg
, gfp_mask
, noswap
);
1518 * Allow limit shrinkers, which are triggered directly
1519 * by userspace, to catch signals and stop reclaim
1520 * after minimal progress, regardless of the margin.
1522 if (total
&& (flags
& MEM_CGROUP_RECLAIM_SHRINK
))
1524 if (mem_cgroup_margin(memcg
))
1527 * If nothing was reclaimed after two attempts, there
1528 * may be no reclaimable pages in this hierarchy.
1537 * test_mem_cgroup_node_reclaimable
1538 * @mem: the target memcg
1539 * @nid: the node ID to be checked.
1540 * @noswap : specify true here if the user wants flle only information.
1542 * This function returns whether the specified memcg contains any
1543 * reclaimable pages on a node. Returns true if there are any reclaimable
1544 * pages in the node.
1546 static bool test_mem_cgroup_node_reclaimable(struct mem_cgroup
*memcg
,
1547 int nid
, bool noswap
)
1549 if (mem_cgroup_node_nr_lru_pages(memcg
, nid
, LRU_ALL_FILE
))
1551 if (noswap
|| !total_swap_pages
)
1553 if (mem_cgroup_node_nr_lru_pages(memcg
, nid
, LRU_ALL_ANON
))
1558 #if MAX_NUMNODES > 1
1561 * Always updating the nodemask is not very good - even if we have an empty
1562 * list or the wrong list here, we can start from some node and traverse all
1563 * nodes based on the zonelist. So update the list loosely once per 10 secs.
1566 static void mem_cgroup_may_update_nodemask(struct mem_cgroup
*memcg
)
1570 * numainfo_events > 0 means there was at least NUMAINFO_EVENTS_TARGET
1571 * pagein/pageout changes since the last update.
1573 if (!atomic_read(&memcg
->numainfo_events
))
1575 if (atomic_inc_return(&memcg
->numainfo_updating
) > 1)
1578 /* make a nodemask where this memcg uses memory from */
1579 memcg
->scan_nodes
= node_states
[N_HIGH_MEMORY
];
1581 for_each_node_mask(nid
, node_states
[N_HIGH_MEMORY
]) {
1583 if (!test_mem_cgroup_node_reclaimable(memcg
, nid
, false))
1584 node_clear(nid
, memcg
->scan_nodes
);
1587 atomic_set(&memcg
->numainfo_events
, 0);
1588 atomic_set(&memcg
->numainfo_updating
, 0);
1592 * Selecting a node where we start reclaim from. Because what we need is just
1593 * reducing usage counter, start from anywhere is O,K. Considering
1594 * memory reclaim from current node, there are pros. and cons.
1596 * Freeing memory from current node means freeing memory from a node which
1597 * we'll use or we've used. So, it may make LRU bad. And if several threads
1598 * hit limits, it will see a contention on a node. But freeing from remote
1599 * node means more costs for memory reclaim because of memory latency.
1601 * Now, we use round-robin. Better algorithm is welcomed.
1603 int mem_cgroup_select_victim_node(struct mem_cgroup
*memcg
)
1607 mem_cgroup_may_update_nodemask(memcg
);
1608 node
= memcg
->last_scanned_node
;
1610 node
= next_node(node
, memcg
->scan_nodes
);
1611 if (node
== MAX_NUMNODES
)
1612 node
= first_node(memcg
->scan_nodes
);
1614 * We call this when we hit limit, not when pages are added to LRU.
1615 * No LRU may hold pages because all pages are UNEVICTABLE or
1616 * memcg is too small and all pages are not on LRU. In that case,
1617 * we use curret node.
1619 if (unlikely(node
== MAX_NUMNODES
))
1620 node
= numa_node_id();
1622 memcg
->last_scanned_node
= node
;
1627 * Check all nodes whether it contains reclaimable pages or not.
1628 * For quick scan, we make use of scan_nodes. This will allow us to skip
1629 * unused nodes. But scan_nodes is lazily updated and may not cotain
1630 * enough new information. We need to do double check.
1632 static bool mem_cgroup_reclaimable(struct mem_cgroup
*memcg
, bool noswap
)
1637 * quick check...making use of scan_node.
1638 * We can skip unused nodes.
1640 if (!nodes_empty(memcg
->scan_nodes
)) {
1641 for (nid
= first_node(memcg
->scan_nodes
);
1643 nid
= next_node(nid
, memcg
->scan_nodes
)) {
1645 if (test_mem_cgroup_node_reclaimable(memcg
, nid
, noswap
))
1650 * Check rest of nodes.
1652 for_each_node_state(nid
, N_HIGH_MEMORY
) {
1653 if (node_isset(nid
, memcg
->scan_nodes
))
1655 if (test_mem_cgroup_node_reclaimable(memcg
, nid
, noswap
))
1662 int mem_cgroup_select_victim_node(struct mem_cgroup
*memcg
)
1667 static bool mem_cgroup_reclaimable(struct mem_cgroup
*memcg
, bool noswap
)
1669 return test_mem_cgroup_node_reclaimable(memcg
, 0, noswap
);
1673 static int mem_cgroup_soft_reclaim(struct mem_cgroup
*root_memcg
,
1676 unsigned long *total_scanned
)
1678 struct mem_cgroup
*victim
= NULL
;
1681 unsigned long excess
;
1682 unsigned long nr_scanned
;
1683 struct mem_cgroup_reclaim_cookie reclaim
= {
1688 excess
= res_counter_soft_limit_excess(&root_memcg
->res
) >> PAGE_SHIFT
;
1691 victim
= mem_cgroup_iter(root_memcg
, victim
, &reclaim
);
1696 * If we have not been able to reclaim
1697 * anything, it might because there are
1698 * no reclaimable pages under this hierarchy
1703 * We want to do more targeted reclaim.
1704 * excess >> 2 is not to excessive so as to
1705 * reclaim too much, nor too less that we keep
1706 * coming back to reclaim from this cgroup
1708 if (total
>= (excess
>> 2) ||
1709 (loop
> MEM_CGROUP_MAX_RECLAIM_LOOPS
))
1714 if (!mem_cgroup_reclaimable(victim
, false))
1716 total
+= mem_cgroup_shrink_node_zone(victim
, gfp_mask
, false,
1718 *total_scanned
+= nr_scanned
;
1719 if (!res_counter_soft_limit_excess(&root_memcg
->res
))
1722 mem_cgroup_iter_break(root_memcg
, victim
);
1727 * Check OOM-Killer is already running under our hierarchy.
1728 * If someone is running, return false.
1729 * Has to be called with memcg_oom_lock
1731 static bool mem_cgroup_oom_lock(struct mem_cgroup
*memcg
)
1733 struct mem_cgroup
*iter
, *failed
= NULL
;
1735 for_each_mem_cgroup_tree(iter
, memcg
) {
1736 if (iter
->oom_lock
) {
1738 * this subtree of our hierarchy is already locked
1739 * so we cannot give a lock.
1742 mem_cgroup_iter_break(memcg
, iter
);
1745 iter
->oom_lock
= true;
1752 * OK, we failed to lock the whole subtree so we have to clean up
1753 * what we set up to the failing subtree
1755 for_each_mem_cgroup_tree(iter
, memcg
) {
1756 if (iter
== failed
) {
1757 mem_cgroup_iter_break(memcg
, iter
);
1760 iter
->oom_lock
= false;
1766 * Has to be called with memcg_oom_lock
1768 static int mem_cgroup_oom_unlock(struct mem_cgroup
*memcg
)
1770 struct mem_cgroup
*iter
;
1772 for_each_mem_cgroup_tree(iter
, memcg
)
1773 iter
->oom_lock
= false;
1777 static void mem_cgroup_mark_under_oom(struct mem_cgroup
*memcg
)
1779 struct mem_cgroup
*iter
;
1781 for_each_mem_cgroup_tree(iter
, memcg
)
1782 atomic_inc(&iter
->under_oom
);
1785 static void mem_cgroup_unmark_under_oom(struct mem_cgroup
*memcg
)
1787 struct mem_cgroup
*iter
;
1790 * When a new child is created while the hierarchy is under oom,
1791 * mem_cgroup_oom_lock() may not be called. We have to use
1792 * atomic_add_unless() here.
1794 for_each_mem_cgroup_tree(iter
, memcg
)
1795 atomic_add_unless(&iter
->under_oom
, -1, 0);
1798 static DEFINE_SPINLOCK(memcg_oom_lock
);
1799 static DECLARE_WAIT_QUEUE_HEAD(memcg_oom_waitq
);
1801 struct oom_wait_info
{
1802 struct mem_cgroup
*memcg
;
1806 static int memcg_oom_wake_function(wait_queue_t
*wait
,
1807 unsigned mode
, int sync
, void *arg
)
1809 struct mem_cgroup
*wake_memcg
= (struct mem_cgroup
*)arg
;
1810 struct mem_cgroup
*oom_wait_memcg
;
1811 struct oom_wait_info
*oom_wait_info
;
1813 oom_wait_info
= container_of(wait
, struct oom_wait_info
, wait
);
1814 oom_wait_memcg
= oom_wait_info
->memcg
;
1817 * Both of oom_wait_info->memcg and wake_memcg are stable under us.
1818 * Then we can use css_is_ancestor without taking care of RCU.
1820 if (!mem_cgroup_same_or_subtree(oom_wait_memcg
, wake_memcg
)
1821 && !mem_cgroup_same_or_subtree(wake_memcg
, oom_wait_memcg
))
1823 return autoremove_wake_function(wait
, mode
, sync
, arg
);
1826 static void memcg_wakeup_oom(struct mem_cgroup
*memcg
)
1828 /* for filtering, pass "memcg" as argument. */
1829 __wake_up(&memcg_oom_waitq
, TASK_NORMAL
, 0, memcg
);
1832 static void memcg_oom_recover(struct mem_cgroup
*memcg
)
1834 if (memcg
&& atomic_read(&memcg
->under_oom
))
1835 memcg_wakeup_oom(memcg
);
1839 * try to call OOM killer. returns false if we should exit memory-reclaim loop.
1841 static bool mem_cgroup_handle_oom(struct mem_cgroup
*memcg
, gfp_t mask
,
1844 struct oom_wait_info owait
;
1845 bool locked
, need_to_kill
;
1847 owait
.memcg
= memcg
;
1848 owait
.wait
.flags
= 0;
1849 owait
.wait
.func
= memcg_oom_wake_function
;
1850 owait
.wait
.private = current
;
1851 INIT_LIST_HEAD(&owait
.wait
.task_list
);
1852 need_to_kill
= true;
1853 mem_cgroup_mark_under_oom(memcg
);
1855 /* At first, try to OOM lock hierarchy under memcg.*/
1856 spin_lock(&memcg_oom_lock
);
1857 locked
= mem_cgroup_oom_lock(memcg
);
1859 * Even if signal_pending(), we can't quit charge() loop without
1860 * accounting. So, UNINTERRUPTIBLE is appropriate. But SIGKILL
1861 * under OOM is always welcomed, use TASK_KILLABLE here.
1863 prepare_to_wait(&memcg_oom_waitq
, &owait
.wait
, TASK_KILLABLE
);
1864 if (!locked
|| memcg
->oom_kill_disable
)
1865 need_to_kill
= false;
1867 mem_cgroup_oom_notify(memcg
);
1868 spin_unlock(&memcg_oom_lock
);
1871 finish_wait(&memcg_oom_waitq
, &owait
.wait
);
1872 mem_cgroup_out_of_memory(memcg
, mask
, order
);
1875 finish_wait(&memcg_oom_waitq
, &owait
.wait
);
1877 spin_lock(&memcg_oom_lock
);
1879 mem_cgroup_oom_unlock(memcg
);
1880 memcg_wakeup_oom(memcg
);
1881 spin_unlock(&memcg_oom_lock
);
1883 mem_cgroup_unmark_under_oom(memcg
);
1885 if (test_thread_flag(TIF_MEMDIE
) || fatal_signal_pending(current
))
1887 /* Give chance to dying process */
1888 schedule_timeout_uninterruptible(1);
1893 * Currently used to update mapped file statistics, but the routine can be
1894 * generalized to update other statistics as well.
1896 * Notes: Race condition
1898 * We usually use page_cgroup_lock() for accessing page_cgroup member but
1899 * it tends to be costly. But considering some conditions, we doesn't need
1900 * to do so _always_.
1902 * Considering "charge", lock_page_cgroup() is not required because all
1903 * file-stat operations happen after a page is attached to radix-tree. There
1904 * are no race with "charge".
1906 * Considering "uncharge", we know that memcg doesn't clear pc->mem_cgroup
1907 * at "uncharge" intentionally. So, we always see valid pc->mem_cgroup even
1908 * if there are race with "uncharge". Statistics itself is properly handled
1911 * Considering "move", this is an only case we see a race. To make the race
1912 * small, we check mm->moving_account and detect there are possibility of race
1913 * If there is, we take a lock.
1916 void __mem_cgroup_begin_update_page_stat(struct page
*page
,
1917 bool *locked
, unsigned long *flags
)
1919 struct mem_cgroup
*memcg
;
1920 struct page_cgroup
*pc
;
1922 pc
= lookup_page_cgroup(page
);
1924 memcg
= pc
->mem_cgroup
;
1925 if (unlikely(!memcg
|| !PageCgroupUsed(pc
)))
1928 * If this memory cgroup is not under account moving, we don't
1929 * need to take move_lock_page_cgroup(). Because we already hold
1930 * rcu_read_lock(), any calls to move_account will be delayed until
1931 * rcu_read_unlock() if mem_cgroup_stolen() == true.
1933 if (!mem_cgroup_stolen(memcg
))
1936 move_lock_mem_cgroup(memcg
, flags
);
1937 if (memcg
!= pc
->mem_cgroup
|| !PageCgroupUsed(pc
)) {
1938 move_unlock_mem_cgroup(memcg
, flags
);
1944 void __mem_cgroup_end_update_page_stat(struct page
*page
, unsigned long *flags
)
1946 struct page_cgroup
*pc
= lookup_page_cgroup(page
);
1949 * It's guaranteed that pc->mem_cgroup never changes while
1950 * lock is held because a routine modifies pc->mem_cgroup
1951 * should take move_lock_page_cgroup().
1953 move_unlock_mem_cgroup(pc
->mem_cgroup
, flags
);
1956 void mem_cgroup_update_page_stat(struct page
*page
,
1957 enum mem_cgroup_page_stat_item idx
, int val
)
1959 struct mem_cgroup
*memcg
;
1960 struct page_cgroup
*pc
= lookup_page_cgroup(page
);
1961 unsigned long uninitialized_var(flags
);
1963 if (mem_cgroup_disabled())
1966 memcg
= pc
->mem_cgroup
;
1967 if (unlikely(!memcg
|| !PageCgroupUsed(pc
)))
1971 case MEMCG_NR_FILE_MAPPED
:
1972 idx
= MEM_CGROUP_STAT_FILE_MAPPED
;
1978 this_cpu_add(memcg
->stat
->count
[idx
], val
);
1982 * size of first charge trial. "32" comes from vmscan.c's magic value.
1983 * TODO: maybe necessary to use big numbers in big irons.
1985 #define CHARGE_BATCH 32U
1986 struct memcg_stock_pcp
{
1987 struct mem_cgroup
*cached
; /* this never be root cgroup */
1988 unsigned int nr_pages
;
1989 struct work_struct work
;
1990 unsigned long flags
;
1991 #define FLUSHING_CACHED_CHARGE 0
1993 static DEFINE_PER_CPU(struct memcg_stock_pcp
, memcg_stock
);
1994 static DEFINE_MUTEX(percpu_charge_mutex
);
1997 * Try to consume stocked charge on this cpu. If success, one page is consumed
1998 * from local stock and true is returned. If the stock is 0 or charges from a
1999 * cgroup which is not current target, returns false. This stock will be
2002 static bool consume_stock(struct mem_cgroup
*memcg
)
2004 struct memcg_stock_pcp
*stock
;
2007 stock
= &get_cpu_var(memcg_stock
);
2008 if (memcg
== stock
->cached
&& stock
->nr_pages
)
2010 else /* need to call res_counter_charge */
2012 put_cpu_var(memcg_stock
);
2017 * Returns stocks cached in percpu to res_counter and reset cached information.
2019 static void drain_stock(struct memcg_stock_pcp
*stock
)
2021 struct mem_cgroup
*old
= stock
->cached
;
2023 if (stock
->nr_pages
) {
2024 unsigned long bytes
= stock
->nr_pages
* PAGE_SIZE
;
2026 res_counter_uncharge(&old
->res
, bytes
);
2027 if (do_swap_account
)
2028 res_counter_uncharge(&old
->memsw
, bytes
);
2029 stock
->nr_pages
= 0;
2031 stock
->cached
= NULL
;
2035 * This must be called under preempt disabled or must be called by
2036 * a thread which is pinned to local cpu.
2038 static void drain_local_stock(struct work_struct
*dummy
)
2040 struct memcg_stock_pcp
*stock
= &__get_cpu_var(memcg_stock
);
2042 clear_bit(FLUSHING_CACHED_CHARGE
, &stock
->flags
);
2046 * Cache charges(val) which is from res_counter, to local per_cpu area.
2047 * This will be consumed by consume_stock() function, later.
2049 static void refill_stock(struct mem_cgroup
*memcg
, unsigned int nr_pages
)
2051 struct memcg_stock_pcp
*stock
= &get_cpu_var(memcg_stock
);
2053 if (stock
->cached
!= memcg
) { /* reset if necessary */
2055 stock
->cached
= memcg
;
2057 stock
->nr_pages
+= nr_pages
;
2058 put_cpu_var(memcg_stock
);
2062 * Drains all per-CPU charge caches for given root_memcg resp. subtree
2063 * of the hierarchy under it. sync flag says whether we should block
2064 * until the work is done.
2066 static void drain_all_stock(struct mem_cgroup
*root_memcg
, bool sync
)
2070 /* Notify other cpus that system-wide "drain" is running */
2073 for_each_online_cpu(cpu
) {
2074 struct memcg_stock_pcp
*stock
= &per_cpu(memcg_stock
, cpu
);
2075 struct mem_cgroup
*memcg
;
2077 memcg
= stock
->cached
;
2078 if (!memcg
|| !stock
->nr_pages
)
2080 if (!mem_cgroup_same_or_subtree(root_memcg
, memcg
))
2082 if (!test_and_set_bit(FLUSHING_CACHED_CHARGE
, &stock
->flags
)) {
2084 drain_local_stock(&stock
->work
);
2086 schedule_work_on(cpu
, &stock
->work
);
2094 for_each_online_cpu(cpu
) {
2095 struct memcg_stock_pcp
*stock
= &per_cpu(memcg_stock
, cpu
);
2096 if (test_bit(FLUSHING_CACHED_CHARGE
, &stock
->flags
))
2097 flush_work(&stock
->work
);
2104 * Tries to drain stocked charges in other cpus. This function is asynchronous
2105 * and just put a work per cpu for draining localy on each cpu. Caller can
2106 * expects some charges will be back to res_counter later but cannot wait for
2109 static void drain_all_stock_async(struct mem_cgroup
*root_memcg
)
2112 * If someone calls draining, avoid adding more kworker runs.
2114 if (!mutex_trylock(&percpu_charge_mutex
))
2116 drain_all_stock(root_memcg
, false);
2117 mutex_unlock(&percpu_charge_mutex
);
2120 /* This is a synchronous drain interface. */
2121 static void drain_all_stock_sync(struct mem_cgroup
*root_memcg
)
2123 /* called when force_empty is called */
2124 mutex_lock(&percpu_charge_mutex
);
2125 drain_all_stock(root_memcg
, true);
2126 mutex_unlock(&percpu_charge_mutex
);
2130 * This function drains percpu counter value from DEAD cpu and
2131 * move it to local cpu. Note that this function can be preempted.
2133 static void mem_cgroup_drain_pcp_counter(struct mem_cgroup
*memcg
, int cpu
)
2137 spin_lock(&memcg
->pcp_counter_lock
);
2138 for (i
= 0; i
< MEM_CGROUP_STAT_DATA
; i
++) {
2139 long x
= per_cpu(memcg
->stat
->count
[i
], cpu
);
2141 per_cpu(memcg
->stat
->count
[i
], cpu
) = 0;
2142 memcg
->nocpu_base
.count
[i
] += x
;
2144 for (i
= 0; i
< MEM_CGROUP_EVENTS_NSTATS
; i
++) {
2145 unsigned long x
= per_cpu(memcg
->stat
->events
[i
], cpu
);
2147 per_cpu(memcg
->stat
->events
[i
], cpu
) = 0;
2148 memcg
->nocpu_base
.events
[i
] += x
;
2150 spin_unlock(&memcg
->pcp_counter_lock
);
2153 static int __cpuinit
memcg_cpu_hotplug_callback(struct notifier_block
*nb
,
2154 unsigned long action
,
2157 int cpu
= (unsigned long)hcpu
;
2158 struct memcg_stock_pcp
*stock
;
2159 struct mem_cgroup
*iter
;
2161 if (action
== CPU_ONLINE
)
2164 if (action
!= CPU_DEAD
&& action
!= CPU_DEAD_FROZEN
)
2167 for_each_mem_cgroup(iter
)
2168 mem_cgroup_drain_pcp_counter(iter
, cpu
);
2170 stock
= &per_cpu(memcg_stock
, cpu
);
2176 /* See __mem_cgroup_try_charge() for details */
2178 CHARGE_OK
, /* success */
2179 CHARGE_RETRY
, /* need to retry but retry is not bad */
2180 CHARGE_NOMEM
, /* we can't do more. return -ENOMEM */
2181 CHARGE_WOULDBLOCK
, /* GFP_WAIT wasn't set and no enough res. */
2182 CHARGE_OOM_DIE
, /* the current is killed because of OOM */
2185 static int mem_cgroup_do_charge(struct mem_cgroup
*memcg
, gfp_t gfp_mask
,
2186 unsigned int nr_pages
, bool oom_check
)
2188 unsigned long csize
= nr_pages
* PAGE_SIZE
;
2189 struct mem_cgroup
*mem_over_limit
;
2190 struct res_counter
*fail_res
;
2191 unsigned long flags
= 0;
2194 ret
= res_counter_charge(&memcg
->res
, csize
, &fail_res
);
2197 if (!do_swap_account
)
2199 ret
= res_counter_charge(&memcg
->memsw
, csize
, &fail_res
);
2203 res_counter_uncharge(&memcg
->res
, csize
);
2204 mem_over_limit
= mem_cgroup_from_res_counter(fail_res
, memsw
);
2205 flags
|= MEM_CGROUP_RECLAIM_NOSWAP
;
2207 mem_over_limit
= mem_cgroup_from_res_counter(fail_res
, res
);
2209 * nr_pages can be either a huge page (HPAGE_PMD_NR), a batch
2210 * of regular pages (CHARGE_BATCH), or a single regular page (1).
2212 * Never reclaim on behalf of optional batching, retry with a
2213 * single page instead.
2215 if (nr_pages
== CHARGE_BATCH
)
2216 return CHARGE_RETRY
;
2218 if (!(gfp_mask
& __GFP_WAIT
))
2219 return CHARGE_WOULDBLOCK
;
2221 ret
= mem_cgroup_reclaim(mem_over_limit
, gfp_mask
, flags
);
2222 if (mem_cgroup_margin(mem_over_limit
) >= nr_pages
)
2223 return CHARGE_RETRY
;
2225 * Even though the limit is exceeded at this point, reclaim
2226 * may have been able to free some pages. Retry the charge
2227 * before killing the task.
2229 * Only for regular pages, though: huge pages are rather
2230 * unlikely to succeed so close to the limit, and we fall back
2231 * to regular pages anyway in case of failure.
2233 if (nr_pages
== 1 && ret
)
2234 return CHARGE_RETRY
;
2237 * At task move, charge accounts can be doubly counted. So, it's
2238 * better to wait until the end of task_move if something is going on.
2240 if (mem_cgroup_wait_acct_move(mem_over_limit
))
2241 return CHARGE_RETRY
;
2243 /* If we don't need to call oom-killer at el, return immediately */
2245 return CHARGE_NOMEM
;
2247 if (!mem_cgroup_handle_oom(mem_over_limit
, gfp_mask
, get_order(csize
)))
2248 return CHARGE_OOM_DIE
;
2250 return CHARGE_RETRY
;
2254 * __mem_cgroup_try_charge() does
2255 * 1. detect memcg to be charged against from passed *mm and *ptr,
2256 * 2. update res_counter
2257 * 3. call memory reclaim if necessary.
2259 * In some special case, if the task is fatal, fatal_signal_pending() or
2260 * has TIF_MEMDIE, this function returns -EINTR while writing root_mem_cgroup
2261 * to *ptr. There are two reasons for this. 1: fatal threads should quit as soon
2262 * as possible without any hazards. 2: all pages should have a valid
2263 * pc->mem_cgroup. If mm is NULL and the caller doesn't pass a valid memcg
2264 * pointer, that is treated as a charge to root_mem_cgroup.
2266 * So __mem_cgroup_try_charge() will return
2267 * 0 ... on success, filling *ptr with a valid memcg pointer.
2268 * -ENOMEM ... charge failure because of resource limits.
2269 * -EINTR ... if thread is fatal. *ptr is filled with root_mem_cgroup.
2271 * Unlike the exported interface, an "oom" parameter is added. if oom==true,
2272 * the oom-killer can be invoked.
2274 static int __mem_cgroup_try_charge(struct mm_struct
*mm
,
2276 unsigned int nr_pages
,
2277 struct mem_cgroup
**ptr
,
2280 unsigned int batch
= max(CHARGE_BATCH
, nr_pages
);
2281 int nr_oom_retries
= MEM_CGROUP_RECLAIM_RETRIES
;
2282 struct mem_cgroup
*memcg
= NULL
;
2286 * Unlike gloval-vm's OOM-kill, we're not in memory shortage
2287 * in system level. So, allow to go ahead dying process in addition to
2290 if (unlikely(test_thread_flag(TIF_MEMDIE
)
2291 || fatal_signal_pending(current
)))
2295 * We always charge the cgroup the mm_struct belongs to.
2296 * The mm_struct's mem_cgroup changes on task migration if the
2297 * thread group leader migrates. It's possible that mm is not
2298 * set, if so charge the init_mm (happens for pagecache usage).
2301 *ptr
= root_mem_cgroup
;
2303 if (*ptr
) { /* css should be a valid one */
2305 VM_BUG_ON(css_is_removed(&memcg
->css
));
2306 if (mem_cgroup_is_root(memcg
))
2308 if (nr_pages
== 1 && consume_stock(memcg
))
2310 css_get(&memcg
->css
);
2312 struct task_struct
*p
;
2315 p
= rcu_dereference(mm
->owner
);
2317 * Because we don't have task_lock(), "p" can exit.
2318 * In that case, "memcg" can point to root or p can be NULL with
2319 * race with swapoff. Then, we have small risk of mis-accouning.
2320 * But such kind of mis-account by race always happens because
2321 * we don't have cgroup_mutex(). It's overkill and we allo that
2323 * (*) swapoff at el will charge against mm-struct not against
2324 * task-struct. So, mm->owner can be NULL.
2326 memcg
= mem_cgroup_from_task(p
);
2328 memcg
= root_mem_cgroup
;
2329 if (mem_cgroup_is_root(memcg
)) {
2333 if (nr_pages
== 1 && consume_stock(memcg
)) {
2335 * It seems dagerous to access memcg without css_get().
2336 * But considering how consume_stok works, it's not
2337 * necessary. If consume_stock success, some charges
2338 * from this memcg are cached on this cpu. So, we
2339 * don't need to call css_get()/css_tryget() before
2340 * calling consume_stock().
2345 /* after here, we may be blocked. we need to get refcnt */
2346 if (!css_tryget(&memcg
->css
)) {
2356 /* If killed, bypass charge */
2357 if (fatal_signal_pending(current
)) {
2358 css_put(&memcg
->css
);
2363 if (oom
&& !nr_oom_retries
) {
2365 nr_oom_retries
= MEM_CGROUP_RECLAIM_RETRIES
;
2368 ret
= mem_cgroup_do_charge(memcg
, gfp_mask
, batch
, oom_check
);
2372 case CHARGE_RETRY
: /* not in OOM situation but retry */
2374 css_put(&memcg
->css
);
2377 case CHARGE_WOULDBLOCK
: /* !__GFP_WAIT */
2378 css_put(&memcg
->css
);
2380 case CHARGE_NOMEM
: /* OOM routine works */
2382 css_put(&memcg
->css
);
2385 /* If oom, we never return -ENOMEM */
2388 case CHARGE_OOM_DIE
: /* Killed by OOM Killer */
2389 css_put(&memcg
->css
);
2392 } while (ret
!= CHARGE_OK
);
2394 if (batch
> nr_pages
)
2395 refill_stock(memcg
, batch
- nr_pages
);
2396 css_put(&memcg
->css
);
2404 *ptr
= root_mem_cgroup
;
2409 * Somemtimes we have to undo a charge we got by try_charge().
2410 * This function is for that and do uncharge, put css's refcnt.
2411 * gotten by try_charge().
2413 static void __mem_cgroup_cancel_charge(struct mem_cgroup
*memcg
,
2414 unsigned int nr_pages
)
2416 if (!mem_cgroup_is_root(memcg
)) {
2417 unsigned long bytes
= nr_pages
* PAGE_SIZE
;
2419 res_counter_uncharge(&memcg
->res
, bytes
);
2420 if (do_swap_account
)
2421 res_counter_uncharge(&memcg
->memsw
, bytes
);
2426 * Cancel chrages in this cgroup....doesn't propagate to parent cgroup.
2427 * This is useful when moving usage to parent cgroup.
2429 static void __mem_cgroup_cancel_local_charge(struct mem_cgroup
*memcg
,
2430 unsigned int nr_pages
)
2432 unsigned long bytes
= nr_pages
* PAGE_SIZE
;
2434 if (mem_cgroup_is_root(memcg
))
2437 res_counter_uncharge_until(&memcg
->res
, memcg
->res
.parent
, bytes
);
2438 if (do_swap_account
)
2439 res_counter_uncharge_until(&memcg
->memsw
,
2440 memcg
->memsw
.parent
, bytes
);
2444 * A helper function to get mem_cgroup from ID. must be called under
2445 * rcu_read_lock(). The caller must check css_is_removed() or some if
2446 * it's concern. (dropping refcnt from swap can be called against removed
2449 static struct mem_cgroup
*mem_cgroup_lookup(unsigned short id
)
2451 struct cgroup_subsys_state
*css
;
2453 /* ID 0 is unused ID */
2456 css
= css_lookup(&mem_cgroup_subsys
, id
);
2459 return container_of(css
, struct mem_cgroup
, css
);
2462 struct mem_cgroup
*try_get_mem_cgroup_from_page(struct page
*page
)
2464 struct mem_cgroup
*memcg
= NULL
;
2465 struct page_cgroup
*pc
;
2469 VM_BUG_ON(!PageLocked(page
));
2471 pc
= lookup_page_cgroup(page
);
2472 lock_page_cgroup(pc
);
2473 if (PageCgroupUsed(pc
)) {
2474 memcg
= pc
->mem_cgroup
;
2475 if (memcg
&& !css_tryget(&memcg
->css
))
2477 } else if (PageSwapCache(page
)) {
2478 ent
.val
= page_private(page
);
2479 id
= lookup_swap_cgroup_id(ent
);
2481 memcg
= mem_cgroup_lookup(id
);
2482 if (memcg
&& !css_tryget(&memcg
->css
))
2486 unlock_page_cgroup(pc
);
2490 static void __mem_cgroup_commit_charge(struct mem_cgroup
*memcg
,
2492 unsigned int nr_pages
,
2493 enum charge_type ctype
,
2496 struct page_cgroup
*pc
= lookup_page_cgroup(page
);
2497 struct zone
*uninitialized_var(zone
);
2498 bool was_on_lru
= false;
2501 lock_page_cgroup(pc
);
2502 if (unlikely(PageCgroupUsed(pc
))) {
2503 unlock_page_cgroup(pc
);
2504 __mem_cgroup_cancel_charge(memcg
, nr_pages
);
2508 * we don't need page_cgroup_lock about tail pages, becase they are not
2509 * accessed by any other context at this point.
2513 * In some cases, SwapCache and FUSE(splice_buf->radixtree), the page
2514 * may already be on some other mem_cgroup's LRU. Take care of it.
2517 zone
= page_zone(page
);
2518 spin_lock_irq(&zone
->lru_lock
);
2519 if (PageLRU(page
)) {
2521 del_page_from_lru_list(zone
, page
, page_lru(page
));
2526 pc
->mem_cgroup
= memcg
;
2528 * We access a page_cgroup asynchronously without lock_page_cgroup().
2529 * Especially when a page_cgroup is taken from a page, pc->mem_cgroup
2530 * is accessed after testing USED bit. To make pc->mem_cgroup visible
2531 * before USED bit, we need memory barrier here.
2532 * See mem_cgroup_add_lru_list(), etc.
2535 SetPageCgroupUsed(pc
);
2539 VM_BUG_ON(PageLRU(page
));
2541 add_page_to_lru_list(zone
, page
, page_lru(page
));
2543 spin_unlock_irq(&zone
->lru_lock
);
2546 if (ctype
== MEM_CGROUP_CHARGE_TYPE_MAPPED
)
2551 mem_cgroup_charge_statistics(memcg
, anon
, nr_pages
);
2552 unlock_page_cgroup(pc
);
2555 * "charge_statistics" updated event counter. Then, check it.
2556 * Insert ancestor (and ancestor's ancestors), to softlimit RB-tree.
2557 * if they exceeds softlimit.
2559 memcg_check_events(memcg
, page
);
2562 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
2564 #define PCGF_NOCOPY_AT_SPLIT (1 << PCG_LOCK | 1 << PCG_MIGRATION)
2566 * Because tail pages are not marked as "used", set it. We're under
2567 * zone->lru_lock, 'splitting on pmd' and compound_lock.
2568 * charge/uncharge will be never happen and move_account() is done under
2569 * compound_lock(), so we don't have to take care of races.
2571 void mem_cgroup_split_huge_fixup(struct page
*head
)
2573 struct page_cgroup
*head_pc
= lookup_page_cgroup(head
);
2574 struct page_cgroup
*pc
;
2577 if (mem_cgroup_disabled())
2579 for (i
= 1; i
< HPAGE_PMD_NR
; i
++) {
2581 pc
->mem_cgroup
= head_pc
->mem_cgroup
;
2582 smp_wmb();/* see __commit_charge() */
2583 pc
->flags
= head_pc
->flags
& ~PCGF_NOCOPY_AT_SPLIT
;
2586 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
2589 * mem_cgroup_move_account - move account of the page
2591 * @nr_pages: number of regular pages (>1 for huge pages)
2592 * @pc: page_cgroup of the page.
2593 * @from: mem_cgroup which the page is moved from.
2594 * @to: mem_cgroup which the page is moved to. @from != @to.
2595 * @uncharge: whether we should call uncharge and css_put against @from.
2597 * The caller must confirm following.
2598 * - page is not on LRU (isolate_page() is useful.)
2599 * - compound_lock is held when nr_pages > 1
2601 * This function doesn't do "charge" nor css_get to new cgroup. It should be
2602 * done by a caller(__mem_cgroup_try_charge would be useful). If @uncharge is
2603 * true, this function does "uncharge" from old cgroup, but it doesn't if
2604 * @uncharge is false, so a caller should do "uncharge".
2606 static int mem_cgroup_move_account(struct page
*page
,
2607 unsigned int nr_pages
,
2608 struct page_cgroup
*pc
,
2609 struct mem_cgroup
*from
,
2610 struct mem_cgroup
*to
,
2613 unsigned long flags
;
2615 bool anon
= PageAnon(page
);
2617 VM_BUG_ON(from
== to
);
2618 VM_BUG_ON(PageLRU(page
));
2620 * The page is isolated from LRU. So, collapse function
2621 * will not handle this page. But page splitting can happen.
2622 * Do this check under compound_page_lock(). The caller should
2626 if (nr_pages
> 1 && !PageTransHuge(page
))
2629 lock_page_cgroup(pc
);
2632 if (!PageCgroupUsed(pc
) || pc
->mem_cgroup
!= from
)
2635 move_lock_mem_cgroup(from
, &flags
);
2637 if (!anon
&& page_mapped(page
)) {
2638 /* Update mapped_file data for mem_cgroup */
2640 __this_cpu_dec(from
->stat
->count
[MEM_CGROUP_STAT_FILE_MAPPED
]);
2641 __this_cpu_inc(to
->stat
->count
[MEM_CGROUP_STAT_FILE_MAPPED
]);
2644 mem_cgroup_charge_statistics(from
, anon
, -nr_pages
);
2646 /* This is not "cancel", but cancel_charge does all we need. */
2647 __mem_cgroup_cancel_charge(from
, nr_pages
);
2649 /* caller should have done css_get */
2650 pc
->mem_cgroup
= to
;
2651 mem_cgroup_charge_statistics(to
, anon
, nr_pages
);
2653 * We charges against "to" which may not have any tasks. Then, "to"
2654 * can be under rmdir(). But in current implementation, caller of
2655 * this function is just force_empty() and move charge, so it's
2656 * guaranteed that "to" is never removed. So, we don't check rmdir
2659 move_unlock_mem_cgroup(from
, &flags
);
2662 unlock_page_cgroup(pc
);
2666 memcg_check_events(to
, page
);
2667 memcg_check_events(from
, page
);
2673 * move charges to its parent.
2676 static int mem_cgroup_move_parent(struct page
*page
,
2677 struct page_cgroup
*pc
,
2678 struct mem_cgroup
*child
,
2681 struct mem_cgroup
*parent
;
2682 unsigned int nr_pages
;
2683 unsigned long uninitialized_var(flags
);
2687 if (mem_cgroup_is_root(child
))
2691 if (!get_page_unless_zero(page
))
2693 if (isolate_lru_page(page
))
2696 nr_pages
= hpage_nr_pages(page
);
2698 parent
= parent_mem_cgroup(child
);
2700 * If no parent, move charges to root cgroup.
2703 parent
= root_mem_cgroup
;
2706 flags
= compound_lock_irqsave(page
);
2708 ret
= mem_cgroup_move_account(page
, nr_pages
,
2709 pc
, child
, parent
, false);
2711 __mem_cgroup_cancel_local_charge(child
, nr_pages
);
2714 compound_unlock_irqrestore(page
, flags
);
2715 putback_lru_page(page
);
2723 * Charge the memory controller for page usage.
2725 * 0 if the charge was successful
2726 * < 0 if the cgroup is over its limit
2728 static int mem_cgroup_charge_common(struct page
*page
, struct mm_struct
*mm
,
2729 gfp_t gfp_mask
, enum charge_type ctype
)
2731 struct mem_cgroup
*memcg
= NULL
;
2732 unsigned int nr_pages
= 1;
2736 if (PageTransHuge(page
)) {
2737 nr_pages
<<= compound_order(page
);
2738 VM_BUG_ON(!PageTransHuge(page
));
2740 * Never OOM-kill a process for a huge page. The
2741 * fault handler will fall back to regular pages.
2746 ret
= __mem_cgroup_try_charge(mm
, gfp_mask
, nr_pages
, &memcg
, oom
);
2749 __mem_cgroup_commit_charge(memcg
, page
, nr_pages
, ctype
, false);
2753 int mem_cgroup_newpage_charge(struct page
*page
,
2754 struct mm_struct
*mm
, gfp_t gfp_mask
)
2756 if (mem_cgroup_disabled())
2758 VM_BUG_ON(page_mapped(page
));
2759 VM_BUG_ON(page
->mapping
&& !PageAnon(page
));
2761 return mem_cgroup_charge_common(page
, mm
, gfp_mask
,
2762 MEM_CGROUP_CHARGE_TYPE_MAPPED
);
2766 __mem_cgroup_commit_charge_swapin(struct page
*page
, struct mem_cgroup
*ptr
,
2767 enum charge_type ctype
);
2769 int mem_cgroup_cache_charge(struct page
*page
, struct mm_struct
*mm
,
2772 struct mem_cgroup
*memcg
= NULL
;
2773 enum charge_type type
= MEM_CGROUP_CHARGE_TYPE_CACHE
;
2776 if (mem_cgroup_disabled())
2778 if (PageCompound(page
))
2783 if (!page_is_file_cache(page
))
2784 type
= MEM_CGROUP_CHARGE_TYPE_SHMEM
;
2786 if (!PageSwapCache(page
))
2787 ret
= mem_cgroup_charge_common(page
, mm
, gfp_mask
, type
);
2788 else { /* page is swapcache/shmem */
2789 ret
= mem_cgroup_try_charge_swapin(mm
, page
, gfp_mask
, &memcg
);
2791 __mem_cgroup_commit_charge_swapin(page
, memcg
, type
);
2797 * While swap-in, try_charge -> commit or cancel, the page is locked.
2798 * And when try_charge() successfully returns, one refcnt to memcg without
2799 * struct page_cgroup is acquired. This refcnt will be consumed by
2800 * "commit()" or removed by "cancel()"
2802 int mem_cgroup_try_charge_swapin(struct mm_struct
*mm
,
2804 gfp_t mask
, struct mem_cgroup
**memcgp
)
2806 struct mem_cgroup
*memcg
;
2811 if (mem_cgroup_disabled())
2814 if (!do_swap_account
)
2817 * A racing thread's fault, or swapoff, may have already updated
2818 * the pte, and even removed page from swap cache: in those cases
2819 * do_swap_page()'s pte_same() test will fail; but there's also a
2820 * KSM case which does need to charge the page.
2822 if (!PageSwapCache(page
))
2824 memcg
= try_get_mem_cgroup_from_page(page
);
2828 ret
= __mem_cgroup_try_charge(NULL
, mask
, 1, memcgp
, true);
2829 css_put(&memcg
->css
);
2836 ret
= __mem_cgroup_try_charge(mm
, mask
, 1, memcgp
, true);
2843 __mem_cgroup_commit_charge_swapin(struct page
*page
, struct mem_cgroup
*memcg
,
2844 enum charge_type ctype
)
2846 if (mem_cgroup_disabled())
2850 cgroup_exclude_rmdir(&memcg
->css
);
2852 __mem_cgroup_commit_charge(memcg
, page
, 1, ctype
, true);
2854 * Now swap is on-memory. This means this page may be
2855 * counted both as mem and swap....double count.
2856 * Fix it by uncharging from memsw. Basically, this SwapCache is stable
2857 * under lock_page(). But in do_swap_page()::memory.c, reuse_swap_page()
2858 * may call delete_from_swap_cache() before reach here.
2860 if (do_swap_account
&& PageSwapCache(page
)) {
2861 swp_entry_t ent
= {.val
= page_private(page
)};
2862 mem_cgroup_uncharge_swap(ent
);
2865 * At swapin, we may charge account against cgroup which has no tasks.
2866 * So, rmdir()->pre_destroy() can be called while we do this charge.
2867 * In that case, we need to call pre_destroy() again. check it here.
2869 cgroup_release_and_wakeup_rmdir(&memcg
->css
);
2872 void mem_cgroup_commit_charge_swapin(struct page
*page
,
2873 struct mem_cgroup
*memcg
)
2875 __mem_cgroup_commit_charge_swapin(page
, memcg
,
2876 MEM_CGROUP_CHARGE_TYPE_MAPPED
);
2879 void mem_cgroup_cancel_charge_swapin(struct mem_cgroup
*memcg
)
2881 if (mem_cgroup_disabled())
2885 __mem_cgroup_cancel_charge(memcg
, 1);
2888 static void mem_cgroup_do_uncharge(struct mem_cgroup
*memcg
,
2889 unsigned int nr_pages
,
2890 const enum charge_type ctype
)
2892 struct memcg_batch_info
*batch
= NULL
;
2893 bool uncharge_memsw
= true;
2895 /* If swapout, usage of swap doesn't decrease */
2896 if (!do_swap_account
|| ctype
== MEM_CGROUP_CHARGE_TYPE_SWAPOUT
)
2897 uncharge_memsw
= false;
2899 batch
= ¤t
->memcg_batch
;
2901 * In usual, we do css_get() when we remember memcg pointer.
2902 * But in this case, we keep res->usage until end of a series of
2903 * uncharges. Then, it's ok to ignore memcg's refcnt.
2906 batch
->memcg
= memcg
;
2908 * do_batch > 0 when unmapping pages or inode invalidate/truncate.
2909 * In those cases, all pages freed continuously can be expected to be in
2910 * the same cgroup and we have chance to coalesce uncharges.
2911 * But we do uncharge one by one if this is killed by OOM(TIF_MEMDIE)
2912 * because we want to do uncharge as soon as possible.
2915 if (!batch
->do_batch
|| test_thread_flag(TIF_MEMDIE
))
2916 goto direct_uncharge
;
2919 goto direct_uncharge
;
2922 * In typical case, batch->memcg == mem. This means we can
2923 * merge a series of uncharges to an uncharge of res_counter.
2924 * If not, we uncharge res_counter ony by one.
2926 if (batch
->memcg
!= memcg
)
2927 goto direct_uncharge
;
2928 /* remember freed charge and uncharge it later */
2931 batch
->memsw_nr_pages
++;
2934 res_counter_uncharge(&memcg
->res
, nr_pages
* PAGE_SIZE
);
2936 res_counter_uncharge(&memcg
->memsw
, nr_pages
* PAGE_SIZE
);
2937 if (unlikely(batch
->memcg
!= memcg
))
2938 memcg_oom_recover(memcg
);
2942 * uncharge if !page_mapped(page)
2944 static struct mem_cgroup
*
2945 __mem_cgroup_uncharge_common(struct page
*page
, enum charge_type ctype
)
2947 struct mem_cgroup
*memcg
= NULL
;
2948 unsigned int nr_pages
= 1;
2949 struct page_cgroup
*pc
;
2952 if (mem_cgroup_disabled())
2955 if (PageSwapCache(page
))
2958 if (PageTransHuge(page
)) {
2959 nr_pages
<<= compound_order(page
);
2960 VM_BUG_ON(!PageTransHuge(page
));
2963 * Check if our page_cgroup is valid
2965 pc
= lookup_page_cgroup(page
);
2966 if (unlikely(!PageCgroupUsed(pc
)))
2969 lock_page_cgroup(pc
);
2971 memcg
= pc
->mem_cgroup
;
2973 if (!PageCgroupUsed(pc
))
2976 anon
= PageAnon(page
);
2979 case MEM_CGROUP_CHARGE_TYPE_MAPPED
:
2981 * Generally PageAnon tells if it's the anon statistics to be
2982 * updated; but sometimes e.g. mem_cgroup_uncharge_page() is
2983 * used before page reached the stage of being marked PageAnon.
2987 case MEM_CGROUP_CHARGE_TYPE_DROP
:
2988 /* See mem_cgroup_prepare_migration() */
2989 if (page_mapped(page
) || PageCgroupMigration(pc
))
2992 case MEM_CGROUP_CHARGE_TYPE_SWAPOUT
:
2993 if (!PageAnon(page
)) { /* Shared memory */
2994 if (page
->mapping
&& !page_is_file_cache(page
))
2996 } else if (page_mapped(page
)) /* Anon */
3003 mem_cgroup_charge_statistics(memcg
, anon
, -nr_pages
);
3005 ClearPageCgroupUsed(pc
);
3007 * pc->mem_cgroup is not cleared here. It will be accessed when it's
3008 * freed from LRU. This is safe because uncharged page is expected not
3009 * to be reused (freed soon). Exception is SwapCache, it's handled by
3010 * special functions.
3013 unlock_page_cgroup(pc
);
3015 * even after unlock, we have memcg->res.usage here and this memcg
3016 * will never be freed.
3018 memcg_check_events(memcg
, page
);
3019 if (do_swap_account
&& ctype
== MEM_CGROUP_CHARGE_TYPE_SWAPOUT
) {
3020 mem_cgroup_swap_statistics(memcg
, true);
3021 mem_cgroup_get(memcg
);
3023 if (!mem_cgroup_is_root(memcg
))
3024 mem_cgroup_do_uncharge(memcg
, nr_pages
, ctype
);
3029 unlock_page_cgroup(pc
);
3033 void mem_cgroup_uncharge_page(struct page
*page
)
3036 if (page_mapped(page
))
3038 VM_BUG_ON(page
->mapping
&& !PageAnon(page
));
3039 __mem_cgroup_uncharge_common(page
, MEM_CGROUP_CHARGE_TYPE_MAPPED
);
3042 void mem_cgroup_uncharge_cache_page(struct page
*page
)
3044 VM_BUG_ON(page_mapped(page
));
3045 VM_BUG_ON(page
->mapping
);
3046 __mem_cgroup_uncharge_common(page
, MEM_CGROUP_CHARGE_TYPE_CACHE
);
3050 * Batch_start/batch_end is called in unmap_page_range/invlidate/trucate.
3051 * In that cases, pages are freed continuously and we can expect pages
3052 * are in the same memcg. All these calls itself limits the number of
3053 * pages freed at once, then uncharge_start/end() is called properly.
3054 * This may be called prural(2) times in a context,
3057 void mem_cgroup_uncharge_start(void)
3059 current
->memcg_batch
.do_batch
++;
3060 /* We can do nest. */
3061 if (current
->memcg_batch
.do_batch
== 1) {
3062 current
->memcg_batch
.memcg
= NULL
;
3063 current
->memcg_batch
.nr_pages
= 0;
3064 current
->memcg_batch
.memsw_nr_pages
= 0;
3068 void mem_cgroup_uncharge_end(void)
3070 struct memcg_batch_info
*batch
= ¤t
->memcg_batch
;
3072 if (!batch
->do_batch
)
3076 if (batch
->do_batch
) /* If stacked, do nothing. */
3082 * This "batch->memcg" is valid without any css_get/put etc...
3083 * bacause we hide charges behind us.
3085 if (batch
->nr_pages
)
3086 res_counter_uncharge(&batch
->memcg
->res
,
3087 batch
->nr_pages
* PAGE_SIZE
);
3088 if (batch
->memsw_nr_pages
)
3089 res_counter_uncharge(&batch
->memcg
->memsw
,
3090 batch
->memsw_nr_pages
* PAGE_SIZE
);
3091 memcg_oom_recover(batch
->memcg
);
3092 /* forget this pointer (for sanity check) */
3093 batch
->memcg
= NULL
;
3098 * called after __delete_from_swap_cache() and drop "page" account.
3099 * memcg information is recorded to swap_cgroup of "ent"
3102 mem_cgroup_uncharge_swapcache(struct page
*page
, swp_entry_t ent
, bool swapout
)
3104 struct mem_cgroup
*memcg
;
3105 int ctype
= MEM_CGROUP_CHARGE_TYPE_SWAPOUT
;
3107 if (!swapout
) /* this was a swap cache but the swap is unused ! */
3108 ctype
= MEM_CGROUP_CHARGE_TYPE_DROP
;
3110 memcg
= __mem_cgroup_uncharge_common(page
, ctype
);
3113 * record memcg information, if swapout && memcg != NULL,
3114 * mem_cgroup_get() was called in uncharge().
3116 if (do_swap_account
&& swapout
&& memcg
)
3117 swap_cgroup_record(ent
, css_id(&memcg
->css
));
3121 #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP
3123 * called from swap_entry_free(). remove record in swap_cgroup and
3124 * uncharge "memsw" account.
3126 void mem_cgroup_uncharge_swap(swp_entry_t ent
)
3128 struct mem_cgroup
*memcg
;
3131 if (!do_swap_account
)
3134 id
= swap_cgroup_record(ent
, 0);
3136 memcg
= mem_cgroup_lookup(id
);
3139 * We uncharge this because swap is freed.
3140 * This memcg can be obsolete one. We avoid calling css_tryget
3142 if (!mem_cgroup_is_root(memcg
))
3143 res_counter_uncharge(&memcg
->memsw
, PAGE_SIZE
);
3144 mem_cgroup_swap_statistics(memcg
, false);
3145 mem_cgroup_put(memcg
);
3151 * mem_cgroup_move_swap_account - move swap charge and swap_cgroup's record.
3152 * @entry: swap entry to be moved
3153 * @from: mem_cgroup which the entry is moved from
3154 * @to: mem_cgroup which the entry is moved to
3156 * It succeeds only when the swap_cgroup's record for this entry is the same
3157 * as the mem_cgroup's id of @from.
3159 * Returns 0 on success, -EINVAL on failure.
3161 * The caller must have charged to @to, IOW, called res_counter_charge() about
3162 * both res and memsw, and called css_get().
3164 static int mem_cgroup_move_swap_account(swp_entry_t entry
,
3165 struct mem_cgroup
*from
, struct mem_cgroup
*to
)
3167 unsigned short old_id
, new_id
;
3169 old_id
= css_id(&from
->css
);
3170 new_id
= css_id(&to
->css
);
3172 if (swap_cgroup_cmpxchg(entry
, old_id
, new_id
) == old_id
) {
3173 mem_cgroup_swap_statistics(from
, false);
3174 mem_cgroup_swap_statistics(to
, true);
3176 * This function is only called from task migration context now.
3177 * It postpones res_counter and refcount handling till the end
3178 * of task migration(mem_cgroup_clear_mc()) for performance
3179 * improvement. But we cannot postpone mem_cgroup_get(to)
3180 * because if the process that has been moved to @to does
3181 * swap-in, the refcount of @to might be decreased to 0.
3189 static inline int mem_cgroup_move_swap_account(swp_entry_t entry
,
3190 struct mem_cgroup
*from
, struct mem_cgroup
*to
)
3197 * Before starting migration, account PAGE_SIZE to mem_cgroup that the old
3200 int mem_cgroup_prepare_migration(struct page
*page
,
3201 struct page
*newpage
, struct mem_cgroup
**memcgp
, gfp_t gfp_mask
)
3203 struct mem_cgroup
*memcg
= NULL
;
3204 struct page_cgroup
*pc
;
3205 enum charge_type ctype
;
3210 VM_BUG_ON(PageTransHuge(page
));
3211 if (mem_cgroup_disabled())
3214 pc
= lookup_page_cgroup(page
);
3215 lock_page_cgroup(pc
);
3216 if (PageCgroupUsed(pc
)) {
3217 memcg
= pc
->mem_cgroup
;
3218 css_get(&memcg
->css
);
3220 * At migrating an anonymous page, its mapcount goes down
3221 * to 0 and uncharge() will be called. But, even if it's fully
3222 * unmapped, migration may fail and this page has to be
3223 * charged again. We set MIGRATION flag here and delay uncharge
3224 * until end_migration() is called
3226 * Corner Case Thinking
3228 * When the old page was mapped as Anon and it's unmap-and-freed
3229 * while migration was ongoing.
3230 * If unmap finds the old page, uncharge() of it will be delayed
3231 * until end_migration(). If unmap finds a new page, it's
3232 * uncharged when it make mapcount to be 1->0. If unmap code
3233 * finds swap_migration_entry, the new page will not be mapped
3234 * and end_migration() will find it(mapcount==0).
3237 * When the old page was mapped but migraion fails, the kernel
3238 * remaps it. A charge for it is kept by MIGRATION flag even
3239 * if mapcount goes down to 0. We can do remap successfully
3240 * without charging it again.
3243 * The "old" page is under lock_page() until the end of
3244 * migration, so, the old page itself will not be swapped-out.
3245 * If the new page is swapped out before end_migraton, our
3246 * hook to usual swap-out path will catch the event.
3249 SetPageCgroupMigration(pc
);
3251 unlock_page_cgroup(pc
);
3253 * If the page is not charged at this point,
3260 ret
= __mem_cgroup_try_charge(NULL
, gfp_mask
, 1, memcgp
, false);
3261 css_put(&memcg
->css
);/* drop extra refcnt */
3263 if (PageAnon(page
)) {
3264 lock_page_cgroup(pc
);
3265 ClearPageCgroupMigration(pc
);
3266 unlock_page_cgroup(pc
);
3268 * The old page may be fully unmapped while we kept it.
3270 mem_cgroup_uncharge_page(page
);
3272 /* we'll need to revisit this error code (we have -EINTR) */
3276 * We charge new page before it's used/mapped. So, even if unlock_page()
3277 * is called before end_migration, we can catch all events on this new
3278 * page. In the case new page is migrated but not remapped, new page's
3279 * mapcount will be finally 0 and we call uncharge in end_migration().
3282 ctype
= MEM_CGROUP_CHARGE_TYPE_MAPPED
;
3283 else if (page_is_file_cache(page
))
3284 ctype
= MEM_CGROUP_CHARGE_TYPE_CACHE
;
3286 ctype
= MEM_CGROUP_CHARGE_TYPE_SHMEM
;
3287 __mem_cgroup_commit_charge(memcg
, newpage
, 1, ctype
, false);
3291 /* remove redundant charge if migration failed*/
3292 void mem_cgroup_end_migration(struct mem_cgroup
*memcg
,
3293 struct page
*oldpage
, struct page
*newpage
, bool migration_ok
)
3295 struct page
*used
, *unused
;
3296 struct page_cgroup
*pc
;
3301 /* blocks rmdir() */
3302 cgroup_exclude_rmdir(&memcg
->css
);
3303 if (!migration_ok
) {
3311 * We disallowed uncharge of pages under migration because mapcount
3312 * of the page goes down to zero, temporarly.
3313 * Clear the flag and check the page should be charged.
3315 pc
= lookup_page_cgroup(oldpage
);
3316 lock_page_cgroup(pc
);
3317 ClearPageCgroupMigration(pc
);
3318 unlock_page_cgroup(pc
);
3319 anon
= PageAnon(used
);
3320 __mem_cgroup_uncharge_common(unused
,
3321 anon
? MEM_CGROUP_CHARGE_TYPE_MAPPED
3322 : MEM_CGROUP_CHARGE_TYPE_CACHE
);
3325 * If a page is a file cache, radix-tree replacement is very atomic
3326 * and we can skip this check. When it was an Anon page, its mapcount
3327 * goes down to 0. But because we added MIGRATION flage, it's not
3328 * uncharged yet. There are several case but page->mapcount check
3329 * and USED bit check in mem_cgroup_uncharge_page() will do enough
3330 * check. (see prepare_charge() also)
3333 mem_cgroup_uncharge_page(used
);
3335 * At migration, we may charge account against cgroup which has no
3337 * So, rmdir()->pre_destroy() can be called while we do this charge.
3338 * In that case, we need to call pre_destroy() again. check it here.
3340 cgroup_release_and_wakeup_rmdir(&memcg
->css
);
3344 * At replace page cache, newpage is not under any memcg but it's on
3345 * LRU. So, this function doesn't touch res_counter but handles LRU
3346 * in correct way. Both pages are locked so we cannot race with uncharge.
3348 void mem_cgroup_replace_page_cache(struct page
*oldpage
,
3349 struct page
*newpage
)
3351 struct mem_cgroup
*memcg
= NULL
;
3352 struct page_cgroup
*pc
;
3353 enum charge_type type
= MEM_CGROUP_CHARGE_TYPE_CACHE
;
3355 if (mem_cgroup_disabled())
3358 pc
= lookup_page_cgroup(oldpage
);
3359 /* fix accounting on old pages */
3360 lock_page_cgroup(pc
);
3361 if (PageCgroupUsed(pc
)) {
3362 memcg
= pc
->mem_cgroup
;
3363 mem_cgroup_charge_statistics(memcg
, false, -1);
3364 ClearPageCgroupUsed(pc
);
3366 unlock_page_cgroup(pc
);
3369 * When called from shmem_replace_page(), in some cases the
3370 * oldpage has already been charged, and in some cases not.
3375 if (PageSwapBacked(oldpage
))
3376 type
= MEM_CGROUP_CHARGE_TYPE_SHMEM
;
3379 * Even if newpage->mapping was NULL before starting replacement,
3380 * the newpage may be on LRU(or pagevec for LRU) already. We lock
3381 * LRU while we overwrite pc->mem_cgroup.
3383 __mem_cgroup_commit_charge(memcg
, newpage
, 1, type
, true);
3386 #ifdef CONFIG_DEBUG_VM
3387 static struct page_cgroup
*lookup_page_cgroup_used(struct page
*page
)
3389 struct page_cgroup
*pc
;
3391 pc
= lookup_page_cgroup(page
);
3393 * Can be NULL while feeding pages into the page allocator for
3394 * the first time, i.e. during boot or memory hotplug;
3395 * or when mem_cgroup_disabled().
3397 if (likely(pc
) && PageCgroupUsed(pc
))
3402 bool mem_cgroup_bad_page_check(struct page
*page
)
3404 if (mem_cgroup_disabled())
3407 return lookup_page_cgroup_used(page
) != NULL
;
3410 void mem_cgroup_print_bad_page(struct page
*page
)
3412 struct page_cgroup
*pc
;
3414 pc
= lookup_page_cgroup_used(page
);
3416 printk(KERN_ALERT
"pc:%p pc->flags:%lx pc->mem_cgroup:%p\n",
3417 pc
, pc
->flags
, pc
->mem_cgroup
);
3422 static DEFINE_MUTEX(set_limit_mutex
);
3424 static int mem_cgroup_resize_limit(struct mem_cgroup
*memcg
,
3425 unsigned long long val
)
3428 u64 memswlimit
, memlimit
;
3430 int children
= mem_cgroup_count_children(memcg
);
3431 u64 curusage
, oldusage
;
3435 * For keeping hierarchical_reclaim simple, how long we should retry
3436 * is depends on callers. We set our retry-count to be function
3437 * of # of children which we should visit in this loop.
3439 retry_count
= MEM_CGROUP_RECLAIM_RETRIES
* children
;
3441 oldusage
= res_counter_read_u64(&memcg
->res
, RES_USAGE
);
3444 while (retry_count
) {
3445 if (signal_pending(current
)) {
3450 * Rather than hide all in some function, I do this in
3451 * open coded manner. You see what this really does.
3452 * We have to guarantee memcg->res.limit < memcg->memsw.limit.
3454 mutex_lock(&set_limit_mutex
);
3455 memswlimit
= res_counter_read_u64(&memcg
->memsw
, RES_LIMIT
);
3456 if (memswlimit
< val
) {
3458 mutex_unlock(&set_limit_mutex
);
3462 memlimit
= res_counter_read_u64(&memcg
->res
, RES_LIMIT
);
3466 ret
= res_counter_set_limit(&memcg
->res
, val
);
3468 if (memswlimit
== val
)
3469 memcg
->memsw_is_minimum
= true;
3471 memcg
->memsw_is_minimum
= false;
3473 mutex_unlock(&set_limit_mutex
);
3478 mem_cgroup_reclaim(memcg
, GFP_KERNEL
,
3479 MEM_CGROUP_RECLAIM_SHRINK
);
3480 curusage
= res_counter_read_u64(&memcg
->res
, RES_USAGE
);
3481 /* Usage is reduced ? */
3482 if (curusage
>= oldusage
)
3485 oldusage
= curusage
;
3487 if (!ret
&& enlarge
)
3488 memcg_oom_recover(memcg
);
3493 static int mem_cgroup_resize_memsw_limit(struct mem_cgroup
*memcg
,
3494 unsigned long long val
)
3497 u64 memlimit
, memswlimit
, oldusage
, curusage
;
3498 int children
= mem_cgroup_count_children(memcg
);
3502 /* see mem_cgroup_resize_res_limit */
3503 retry_count
= children
* MEM_CGROUP_RECLAIM_RETRIES
;
3504 oldusage
= res_counter_read_u64(&memcg
->memsw
, RES_USAGE
);
3505 while (retry_count
) {
3506 if (signal_pending(current
)) {
3511 * Rather than hide all in some function, I do this in
3512 * open coded manner. You see what this really does.
3513 * We have to guarantee memcg->res.limit < memcg->memsw.limit.
3515 mutex_lock(&set_limit_mutex
);
3516 memlimit
= res_counter_read_u64(&memcg
->res
, RES_LIMIT
);
3517 if (memlimit
> val
) {
3519 mutex_unlock(&set_limit_mutex
);
3522 memswlimit
= res_counter_read_u64(&memcg
->memsw
, RES_LIMIT
);
3523 if (memswlimit
< val
)
3525 ret
= res_counter_set_limit(&memcg
->memsw
, val
);
3527 if (memlimit
== val
)
3528 memcg
->memsw_is_minimum
= true;
3530 memcg
->memsw_is_minimum
= false;
3532 mutex_unlock(&set_limit_mutex
);
3537 mem_cgroup_reclaim(memcg
, GFP_KERNEL
,
3538 MEM_CGROUP_RECLAIM_NOSWAP
|
3539 MEM_CGROUP_RECLAIM_SHRINK
);
3540 curusage
= res_counter_read_u64(&memcg
->memsw
, RES_USAGE
);
3541 /* Usage is reduced ? */
3542 if (curusage
>= oldusage
)
3545 oldusage
= curusage
;
3547 if (!ret
&& enlarge
)
3548 memcg_oom_recover(memcg
);
3552 unsigned long mem_cgroup_soft_limit_reclaim(struct zone
*zone
, int order
,
3554 unsigned long *total_scanned
)
3556 unsigned long nr_reclaimed
= 0;
3557 struct mem_cgroup_per_zone
*mz
, *next_mz
= NULL
;
3558 unsigned long reclaimed
;
3560 struct mem_cgroup_tree_per_zone
*mctz
;
3561 unsigned long long excess
;
3562 unsigned long nr_scanned
;
3567 mctz
= soft_limit_tree_node_zone(zone_to_nid(zone
), zone_idx(zone
));
3569 * This loop can run a while, specially if mem_cgroup's continuously
3570 * keep exceeding their soft limit and putting the system under
3577 mz
= mem_cgroup_largest_soft_limit_node(mctz
);
3582 reclaimed
= mem_cgroup_soft_reclaim(mz
->memcg
, zone
,
3583 gfp_mask
, &nr_scanned
);
3584 nr_reclaimed
+= reclaimed
;
3585 *total_scanned
+= nr_scanned
;
3586 spin_lock(&mctz
->lock
);
3589 * If we failed to reclaim anything from this memory cgroup
3590 * it is time to move on to the next cgroup
3596 * Loop until we find yet another one.
3598 * By the time we get the soft_limit lock
3599 * again, someone might have aded the
3600 * group back on the RB tree. Iterate to
3601 * make sure we get a different mem.
3602 * mem_cgroup_largest_soft_limit_node returns
3603 * NULL if no other cgroup is present on
3607 __mem_cgroup_largest_soft_limit_node(mctz
);
3609 css_put(&next_mz
->memcg
->css
);
3610 else /* next_mz == NULL or other memcg */
3614 __mem_cgroup_remove_exceeded(mz
->memcg
, mz
, mctz
);
3615 excess
= res_counter_soft_limit_excess(&mz
->memcg
->res
);
3617 * One school of thought says that we should not add
3618 * back the node to the tree if reclaim returns 0.
3619 * But our reclaim could return 0, simply because due
3620 * to priority we are exposing a smaller subset of
3621 * memory to reclaim from. Consider this as a longer
3624 /* If excess == 0, no tree ops */
3625 __mem_cgroup_insert_exceeded(mz
->memcg
, mz
, mctz
, excess
);
3626 spin_unlock(&mctz
->lock
);
3627 css_put(&mz
->memcg
->css
);
3630 * Could not reclaim anything and there are no more
3631 * mem cgroups to try or we seem to be looping without
3632 * reclaiming anything.
3634 if (!nr_reclaimed
&&
3636 loop
> MEM_CGROUP_MAX_SOFT_LIMIT_RECLAIM_LOOPS
))
3638 } while (!nr_reclaimed
);
3640 css_put(&next_mz
->memcg
->css
);
3641 return nr_reclaimed
;
3645 * This routine traverse page_cgroup in given list and drop them all.
3646 * *And* this routine doesn't reclaim page itself, just removes page_cgroup.
3648 static int mem_cgroup_force_empty_list(struct mem_cgroup
*memcg
,
3649 int node
, int zid
, enum lru_list lru
)
3651 struct mem_cgroup_per_zone
*mz
;
3652 unsigned long flags
, loop
;
3653 struct list_head
*list
;
3658 zone
= &NODE_DATA(node
)->node_zones
[zid
];
3659 mz
= mem_cgroup_zoneinfo(memcg
, node
, zid
);
3660 list
= &mz
->lruvec
.lists
[lru
];
3662 loop
= mz
->lru_size
[lru
];
3663 /* give some margin against EBUSY etc...*/
3667 struct page_cgroup
*pc
;
3671 spin_lock_irqsave(&zone
->lru_lock
, flags
);
3672 if (list_empty(list
)) {
3673 spin_unlock_irqrestore(&zone
->lru_lock
, flags
);
3676 page
= list_entry(list
->prev
, struct page
, lru
);
3678 list_move(&page
->lru
, list
);
3680 spin_unlock_irqrestore(&zone
->lru_lock
, flags
);
3683 spin_unlock_irqrestore(&zone
->lru_lock
, flags
);
3685 pc
= lookup_page_cgroup(page
);
3687 ret
= mem_cgroup_move_parent(page
, pc
, memcg
, GFP_KERNEL
);
3688 if (ret
== -ENOMEM
|| ret
== -EINTR
)
3691 if (ret
== -EBUSY
|| ret
== -EINVAL
) {
3692 /* found lock contention or "pc" is obsolete. */
3699 if (!ret
&& !list_empty(list
))
3705 * make mem_cgroup's charge to be 0 if there is no task.
3706 * This enables deleting this mem_cgroup.
3708 static int mem_cgroup_force_empty(struct mem_cgroup
*memcg
, bool free_all
)
3711 int node
, zid
, shrink
;
3712 int nr_retries
= MEM_CGROUP_RECLAIM_RETRIES
;
3713 struct cgroup
*cgrp
= memcg
->css
.cgroup
;
3715 css_get(&memcg
->css
);
3718 /* should free all ? */
3724 if (cgroup_task_count(cgrp
) || !list_empty(&cgrp
->children
))
3727 if (signal_pending(current
))
3729 /* This is for making all *used* pages to be on LRU. */
3730 lru_add_drain_all();
3731 drain_all_stock_sync(memcg
);
3733 mem_cgroup_start_move(memcg
);
3734 for_each_node_state(node
, N_HIGH_MEMORY
) {
3735 for (zid
= 0; !ret
&& zid
< MAX_NR_ZONES
; zid
++) {
3738 ret
= mem_cgroup_force_empty_list(memcg
,
3747 mem_cgroup_end_move(memcg
);
3748 memcg_oom_recover(memcg
);
3749 /* it seems parent cgroup doesn't have enough mem */
3753 /* "ret" should also be checked to ensure all lists are empty. */
3754 } while (res_counter_read_u64(&memcg
->res
, RES_USAGE
) > 0 || ret
);
3756 css_put(&memcg
->css
);
3760 /* returns EBUSY if there is a task or if we come here twice. */
3761 if (cgroup_task_count(cgrp
) || !list_empty(&cgrp
->children
) || shrink
) {
3765 /* we call try-to-free pages for make this cgroup empty */
3766 lru_add_drain_all();
3767 /* try to free all pages in this cgroup */
3769 while (nr_retries
&& res_counter_read_u64(&memcg
->res
, RES_USAGE
) > 0) {
3772 if (signal_pending(current
)) {
3776 progress
= try_to_free_mem_cgroup_pages(memcg
, GFP_KERNEL
,
3780 /* maybe some writeback is necessary */
3781 congestion_wait(BLK_RW_ASYNC
, HZ
/10);
3786 /* try move_account...there may be some *locked* pages. */
3790 static int mem_cgroup_force_empty_write(struct cgroup
*cont
, unsigned int event
)
3792 return mem_cgroup_force_empty(mem_cgroup_from_cont(cont
), true);
3796 static u64
mem_cgroup_hierarchy_read(struct cgroup
*cont
, struct cftype
*cft
)
3798 return mem_cgroup_from_cont(cont
)->use_hierarchy
;
3801 static int mem_cgroup_hierarchy_write(struct cgroup
*cont
, struct cftype
*cft
,
3805 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cont
);
3806 struct cgroup
*parent
= cont
->parent
;
3807 struct mem_cgroup
*parent_memcg
= NULL
;
3810 parent_memcg
= mem_cgroup_from_cont(parent
);
3814 * If parent's use_hierarchy is set, we can't make any modifications
3815 * in the child subtrees. If it is unset, then the change can
3816 * occur, provided the current cgroup has no children.
3818 * For the root cgroup, parent_mem is NULL, we allow value to be
3819 * set if there are no children.
3821 if ((!parent_memcg
|| !parent_memcg
->use_hierarchy
) &&
3822 (val
== 1 || val
== 0)) {
3823 if (list_empty(&cont
->children
))
3824 memcg
->use_hierarchy
= val
;
3835 static unsigned long mem_cgroup_recursive_stat(struct mem_cgroup
*memcg
,
3836 enum mem_cgroup_stat_index idx
)
3838 struct mem_cgroup
*iter
;
3841 /* Per-cpu values can be negative, use a signed accumulator */
3842 for_each_mem_cgroup_tree(iter
, memcg
)
3843 val
+= mem_cgroup_read_stat(iter
, idx
);
3845 if (val
< 0) /* race ? */
3850 static inline u64
mem_cgroup_usage(struct mem_cgroup
*memcg
, bool swap
)
3854 if (!mem_cgroup_is_root(memcg
)) {
3856 return res_counter_read_u64(&memcg
->res
, RES_USAGE
);
3858 return res_counter_read_u64(&memcg
->memsw
, RES_USAGE
);
3861 val
= mem_cgroup_recursive_stat(memcg
, MEM_CGROUP_STAT_CACHE
);
3862 val
+= mem_cgroup_recursive_stat(memcg
, MEM_CGROUP_STAT_RSS
);
3865 val
+= mem_cgroup_recursive_stat(memcg
, MEM_CGROUP_STAT_SWAPOUT
);
3867 return val
<< PAGE_SHIFT
;
3870 static ssize_t
mem_cgroup_read(struct cgroup
*cont
, struct cftype
*cft
,
3871 struct file
*file
, char __user
*buf
,
3872 size_t nbytes
, loff_t
*ppos
)
3874 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cont
);
3877 int type
, name
, len
;
3879 type
= MEMFILE_TYPE(cft
->private);
3880 name
= MEMFILE_ATTR(cft
->private);
3882 if (!do_swap_account
&& type
== _MEMSWAP
)
3887 if (name
== RES_USAGE
)
3888 val
= mem_cgroup_usage(memcg
, false);
3890 val
= res_counter_read_u64(&memcg
->res
, name
);
3893 if (name
== RES_USAGE
)
3894 val
= mem_cgroup_usage(memcg
, true);
3896 val
= res_counter_read_u64(&memcg
->memsw
, name
);
3902 len
= scnprintf(str
, sizeof(str
), "%llu\n", (unsigned long long)val
);
3903 return simple_read_from_buffer(buf
, nbytes
, ppos
, str
, len
);
3906 * The user of this function is...
3909 static int mem_cgroup_write(struct cgroup
*cont
, struct cftype
*cft
,
3912 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cont
);
3914 unsigned long long val
;
3917 type
= MEMFILE_TYPE(cft
->private);
3918 name
= MEMFILE_ATTR(cft
->private);
3920 if (!do_swap_account
&& type
== _MEMSWAP
)
3925 if (mem_cgroup_is_root(memcg
)) { /* Can't set limit on root */
3929 /* This function does all necessary parse...reuse it */
3930 ret
= res_counter_memparse_write_strategy(buffer
, &val
);
3934 ret
= mem_cgroup_resize_limit(memcg
, val
);
3936 ret
= mem_cgroup_resize_memsw_limit(memcg
, val
);
3938 case RES_SOFT_LIMIT
:
3939 ret
= res_counter_memparse_write_strategy(buffer
, &val
);
3943 * For memsw, soft limits are hard to implement in terms
3944 * of semantics, for now, we support soft limits for
3945 * control without swap
3948 ret
= res_counter_set_soft_limit(&memcg
->res
, val
);
3953 ret
= -EINVAL
; /* should be BUG() ? */
3959 static void memcg_get_hierarchical_limit(struct mem_cgroup
*memcg
,
3960 unsigned long long *mem_limit
, unsigned long long *memsw_limit
)
3962 struct cgroup
*cgroup
;
3963 unsigned long long min_limit
, min_memsw_limit
, tmp
;
3965 min_limit
= res_counter_read_u64(&memcg
->res
, RES_LIMIT
);
3966 min_memsw_limit
= res_counter_read_u64(&memcg
->memsw
, RES_LIMIT
);
3967 cgroup
= memcg
->css
.cgroup
;
3968 if (!memcg
->use_hierarchy
)
3971 while (cgroup
->parent
) {
3972 cgroup
= cgroup
->parent
;
3973 memcg
= mem_cgroup_from_cont(cgroup
);
3974 if (!memcg
->use_hierarchy
)
3976 tmp
= res_counter_read_u64(&memcg
->res
, RES_LIMIT
);
3977 min_limit
= min(min_limit
, tmp
);
3978 tmp
= res_counter_read_u64(&memcg
->memsw
, RES_LIMIT
);
3979 min_memsw_limit
= min(min_memsw_limit
, tmp
);
3982 *mem_limit
= min_limit
;
3983 *memsw_limit
= min_memsw_limit
;
3986 static int mem_cgroup_reset(struct cgroup
*cont
, unsigned int event
)
3988 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cont
);
3991 type
= MEMFILE_TYPE(event
);
3992 name
= MEMFILE_ATTR(event
);
3994 if (!do_swap_account
&& type
== _MEMSWAP
)
4000 res_counter_reset_max(&memcg
->res
);
4002 res_counter_reset_max(&memcg
->memsw
);
4006 res_counter_reset_failcnt(&memcg
->res
);
4008 res_counter_reset_failcnt(&memcg
->memsw
);
4015 static u64
mem_cgroup_move_charge_read(struct cgroup
*cgrp
,
4018 return mem_cgroup_from_cont(cgrp
)->move_charge_at_immigrate
;
4022 static int mem_cgroup_move_charge_write(struct cgroup
*cgrp
,
4023 struct cftype
*cft
, u64 val
)
4025 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cgrp
);
4027 if (val
>= (1 << NR_MOVE_TYPE
))
4030 * We check this value several times in both in can_attach() and
4031 * attach(), so we need cgroup lock to prevent this value from being
4035 memcg
->move_charge_at_immigrate
= val
;
4041 static int mem_cgroup_move_charge_write(struct cgroup
*cgrp
,
4042 struct cftype
*cft
, u64 val
)
4049 /* For read statistics */
4067 struct mcs_total_stat
{
4068 s64 stat
[NR_MCS_STAT
];
4074 } memcg_stat_strings
[NR_MCS_STAT
] = {
4075 {"cache", "total_cache"},
4076 {"rss", "total_rss"},
4077 {"mapped_file", "total_mapped_file"},
4078 {"pgpgin", "total_pgpgin"},
4079 {"pgpgout", "total_pgpgout"},
4080 {"swap", "total_swap"},
4081 {"pgfault", "total_pgfault"},
4082 {"pgmajfault", "total_pgmajfault"},
4083 {"inactive_anon", "total_inactive_anon"},
4084 {"active_anon", "total_active_anon"},
4085 {"inactive_file", "total_inactive_file"},
4086 {"active_file", "total_active_file"},
4087 {"unevictable", "total_unevictable"}
4092 mem_cgroup_get_local_stat(struct mem_cgroup
*memcg
, struct mcs_total_stat
*s
)
4097 val
= mem_cgroup_read_stat(memcg
, MEM_CGROUP_STAT_CACHE
);
4098 s
->stat
[MCS_CACHE
] += val
* PAGE_SIZE
;
4099 val
= mem_cgroup_read_stat(memcg
, MEM_CGROUP_STAT_RSS
);
4100 s
->stat
[MCS_RSS
] += val
* PAGE_SIZE
;
4101 val
= mem_cgroup_read_stat(memcg
, MEM_CGROUP_STAT_FILE_MAPPED
);
4102 s
->stat
[MCS_FILE_MAPPED
] += val
* PAGE_SIZE
;
4103 val
= mem_cgroup_read_events(memcg
, MEM_CGROUP_EVENTS_PGPGIN
);
4104 s
->stat
[MCS_PGPGIN
] += val
;
4105 val
= mem_cgroup_read_events(memcg
, MEM_CGROUP_EVENTS_PGPGOUT
);
4106 s
->stat
[MCS_PGPGOUT
] += val
;
4107 if (do_swap_account
) {
4108 val
= mem_cgroup_read_stat(memcg
, MEM_CGROUP_STAT_SWAPOUT
);
4109 s
->stat
[MCS_SWAP
] += val
* PAGE_SIZE
;
4111 val
= mem_cgroup_read_events(memcg
, MEM_CGROUP_EVENTS_PGFAULT
);
4112 s
->stat
[MCS_PGFAULT
] += val
;
4113 val
= mem_cgroup_read_events(memcg
, MEM_CGROUP_EVENTS_PGMAJFAULT
);
4114 s
->stat
[MCS_PGMAJFAULT
] += val
;
4117 val
= mem_cgroup_nr_lru_pages(memcg
, BIT(LRU_INACTIVE_ANON
));
4118 s
->stat
[MCS_INACTIVE_ANON
] += val
* PAGE_SIZE
;
4119 val
= mem_cgroup_nr_lru_pages(memcg
, BIT(LRU_ACTIVE_ANON
));
4120 s
->stat
[MCS_ACTIVE_ANON
] += val
* PAGE_SIZE
;
4121 val
= mem_cgroup_nr_lru_pages(memcg
, BIT(LRU_INACTIVE_FILE
));
4122 s
->stat
[MCS_INACTIVE_FILE
] += val
* PAGE_SIZE
;
4123 val
= mem_cgroup_nr_lru_pages(memcg
, BIT(LRU_ACTIVE_FILE
));
4124 s
->stat
[MCS_ACTIVE_FILE
] += val
* PAGE_SIZE
;
4125 val
= mem_cgroup_nr_lru_pages(memcg
, BIT(LRU_UNEVICTABLE
));
4126 s
->stat
[MCS_UNEVICTABLE
] += val
* PAGE_SIZE
;
4130 mem_cgroup_get_total_stat(struct mem_cgroup
*memcg
, struct mcs_total_stat
*s
)
4132 struct mem_cgroup
*iter
;
4134 for_each_mem_cgroup_tree(iter
, memcg
)
4135 mem_cgroup_get_local_stat(iter
, s
);
4139 static int mem_control_numa_stat_show(struct seq_file
*m
, void *arg
)
4142 unsigned long total_nr
, file_nr
, anon_nr
, unevictable_nr
;
4143 unsigned long node_nr
;
4144 struct cgroup
*cont
= m
->private;
4145 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cont
);
4147 total_nr
= mem_cgroup_nr_lru_pages(memcg
, LRU_ALL
);
4148 seq_printf(m
, "total=%lu", total_nr
);
4149 for_each_node_state(nid
, N_HIGH_MEMORY
) {
4150 node_nr
= mem_cgroup_node_nr_lru_pages(memcg
, nid
, LRU_ALL
);
4151 seq_printf(m
, " N%d=%lu", nid
, node_nr
);
4155 file_nr
= mem_cgroup_nr_lru_pages(memcg
, LRU_ALL_FILE
);
4156 seq_printf(m
, "file=%lu", file_nr
);
4157 for_each_node_state(nid
, N_HIGH_MEMORY
) {
4158 node_nr
= mem_cgroup_node_nr_lru_pages(memcg
, nid
,
4160 seq_printf(m
, " N%d=%lu", nid
, node_nr
);
4164 anon_nr
= mem_cgroup_nr_lru_pages(memcg
, LRU_ALL_ANON
);
4165 seq_printf(m
, "anon=%lu", anon_nr
);
4166 for_each_node_state(nid
, N_HIGH_MEMORY
) {
4167 node_nr
= mem_cgroup_node_nr_lru_pages(memcg
, nid
,
4169 seq_printf(m
, " N%d=%lu", nid
, node_nr
);
4173 unevictable_nr
= mem_cgroup_nr_lru_pages(memcg
, BIT(LRU_UNEVICTABLE
));
4174 seq_printf(m
, "unevictable=%lu", unevictable_nr
);
4175 for_each_node_state(nid
, N_HIGH_MEMORY
) {
4176 node_nr
= mem_cgroup_node_nr_lru_pages(memcg
, nid
,
4177 BIT(LRU_UNEVICTABLE
));
4178 seq_printf(m
, " N%d=%lu", nid
, node_nr
);
4183 #endif /* CONFIG_NUMA */
4185 static int mem_control_stat_show(struct cgroup
*cont
, struct cftype
*cft
,
4186 struct cgroup_map_cb
*cb
)
4188 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cont
);
4189 struct mcs_total_stat mystat
;
4192 memset(&mystat
, 0, sizeof(mystat
));
4193 mem_cgroup_get_local_stat(memcg
, &mystat
);
4196 for (i
= 0; i
< NR_MCS_STAT
; i
++) {
4197 if (i
== MCS_SWAP
&& !do_swap_account
)
4199 cb
->fill(cb
, memcg_stat_strings
[i
].local_name
, mystat
.stat
[i
]);
4202 /* Hierarchical information */
4204 unsigned long long limit
, memsw_limit
;
4205 memcg_get_hierarchical_limit(memcg
, &limit
, &memsw_limit
);
4206 cb
->fill(cb
, "hierarchical_memory_limit", limit
);
4207 if (do_swap_account
)
4208 cb
->fill(cb
, "hierarchical_memsw_limit", memsw_limit
);
4211 memset(&mystat
, 0, sizeof(mystat
));
4212 mem_cgroup_get_total_stat(memcg
, &mystat
);
4213 for (i
= 0; i
< NR_MCS_STAT
; i
++) {
4214 if (i
== MCS_SWAP
&& !do_swap_account
)
4216 cb
->fill(cb
, memcg_stat_strings
[i
].total_name
, mystat
.stat
[i
]);
4219 #ifdef CONFIG_DEBUG_VM
4222 struct mem_cgroup_per_zone
*mz
;
4223 struct zone_reclaim_stat
*rstat
;
4224 unsigned long recent_rotated
[2] = {0, 0};
4225 unsigned long recent_scanned
[2] = {0, 0};
4227 for_each_online_node(nid
)
4228 for (zid
= 0; zid
< MAX_NR_ZONES
; zid
++) {
4229 mz
= mem_cgroup_zoneinfo(memcg
, nid
, zid
);
4230 rstat
= &mz
->lruvec
.reclaim_stat
;
4232 recent_rotated
[0] += rstat
->recent_rotated
[0];
4233 recent_rotated
[1] += rstat
->recent_rotated
[1];
4234 recent_scanned
[0] += rstat
->recent_scanned
[0];
4235 recent_scanned
[1] += rstat
->recent_scanned
[1];
4237 cb
->fill(cb
, "recent_rotated_anon", recent_rotated
[0]);
4238 cb
->fill(cb
, "recent_rotated_file", recent_rotated
[1]);
4239 cb
->fill(cb
, "recent_scanned_anon", recent_scanned
[0]);
4240 cb
->fill(cb
, "recent_scanned_file", recent_scanned
[1]);
4247 static u64
mem_cgroup_swappiness_read(struct cgroup
*cgrp
, struct cftype
*cft
)
4249 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cgrp
);
4251 return mem_cgroup_swappiness(memcg
);
4254 static int mem_cgroup_swappiness_write(struct cgroup
*cgrp
, struct cftype
*cft
,
4257 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cgrp
);
4258 struct mem_cgroup
*parent
;
4263 if (cgrp
->parent
== NULL
)
4266 parent
= mem_cgroup_from_cont(cgrp
->parent
);
4270 /* If under hierarchy, only empty-root can set this value */
4271 if ((parent
->use_hierarchy
) ||
4272 (memcg
->use_hierarchy
&& !list_empty(&cgrp
->children
))) {
4277 memcg
->swappiness
= val
;
4284 static void __mem_cgroup_threshold(struct mem_cgroup
*memcg
, bool swap
)
4286 struct mem_cgroup_threshold_ary
*t
;
4292 t
= rcu_dereference(memcg
->thresholds
.primary
);
4294 t
= rcu_dereference(memcg
->memsw_thresholds
.primary
);
4299 usage
= mem_cgroup_usage(memcg
, swap
);
4302 * current_threshold points to threshold just below or equal to usage.
4303 * If it's not true, a threshold was crossed after last
4304 * call of __mem_cgroup_threshold().
4306 i
= t
->current_threshold
;
4309 * Iterate backward over array of thresholds starting from
4310 * current_threshold and check if a threshold is crossed.
4311 * If none of thresholds below usage is crossed, we read
4312 * only one element of the array here.
4314 for (; i
>= 0 && unlikely(t
->entries
[i
].threshold
> usage
); i
--)
4315 eventfd_signal(t
->entries
[i
].eventfd
, 1);
4317 /* i = current_threshold + 1 */
4321 * Iterate forward over array of thresholds starting from
4322 * current_threshold+1 and check if a threshold is crossed.
4323 * If none of thresholds above usage is crossed, we read
4324 * only one element of the array here.
4326 for (; i
< t
->size
&& unlikely(t
->entries
[i
].threshold
<= usage
); i
++)
4327 eventfd_signal(t
->entries
[i
].eventfd
, 1);
4329 /* Update current_threshold */
4330 t
->current_threshold
= i
- 1;
4335 static void mem_cgroup_threshold(struct mem_cgroup
*memcg
)
4338 __mem_cgroup_threshold(memcg
, false);
4339 if (do_swap_account
)
4340 __mem_cgroup_threshold(memcg
, true);
4342 memcg
= parent_mem_cgroup(memcg
);
4346 static int compare_thresholds(const void *a
, const void *b
)
4348 const struct mem_cgroup_threshold
*_a
= a
;
4349 const struct mem_cgroup_threshold
*_b
= b
;
4351 return _a
->threshold
- _b
->threshold
;
4354 static int mem_cgroup_oom_notify_cb(struct mem_cgroup
*memcg
)
4356 struct mem_cgroup_eventfd_list
*ev
;
4358 list_for_each_entry(ev
, &memcg
->oom_notify
, list
)
4359 eventfd_signal(ev
->eventfd
, 1);
4363 static void mem_cgroup_oom_notify(struct mem_cgroup
*memcg
)
4365 struct mem_cgroup
*iter
;
4367 for_each_mem_cgroup_tree(iter
, memcg
)
4368 mem_cgroup_oom_notify_cb(iter
);
4371 static int mem_cgroup_usage_register_event(struct cgroup
*cgrp
,
4372 struct cftype
*cft
, struct eventfd_ctx
*eventfd
, const char *args
)
4374 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cgrp
);
4375 struct mem_cgroup_thresholds
*thresholds
;
4376 struct mem_cgroup_threshold_ary
*new;
4377 int type
= MEMFILE_TYPE(cft
->private);
4378 u64 threshold
, usage
;
4381 ret
= res_counter_memparse_write_strategy(args
, &threshold
);
4385 mutex_lock(&memcg
->thresholds_lock
);
4388 thresholds
= &memcg
->thresholds
;
4389 else if (type
== _MEMSWAP
)
4390 thresholds
= &memcg
->memsw_thresholds
;
4394 usage
= mem_cgroup_usage(memcg
, type
== _MEMSWAP
);
4396 /* Check if a threshold crossed before adding a new one */
4397 if (thresholds
->primary
)
4398 __mem_cgroup_threshold(memcg
, type
== _MEMSWAP
);
4400 size
= thresholds
->primary
? thresholds
->primary
->size
+ 1 : 1;
4402 /* Allocate memory for new array of thresholds */
4403 new = kmalloc(sizeof(*new) + size
* sizeof(struct mem_cgroup_threshold
),
4411 /* Copy thresholds (if any) to new array */
4412 if (thresholds
->primary
) {
4413 memcpy(new->entries
, thresholds
->primary
->entries
, (size
- 1) *
4414 sizeof(struct mem_cgroup_threshold
));
4417 /* Add new threshold */
4418 new->entries
[size
- 1].eventfd
= eventfd
;
4419 new->entries
[size
- 1].threshold
= threshold
;
4421 /* Sort thresholds. Registering of new threshold isn't time-critical */
4422 sort(new->entries
, size
, sizeof(struct mem_cgroup_threshold
),
4423 compare_thresholds
, NULL
);
4425 /* Find current threshold */
4426 new->current_threshold
= -1;
4427 for (i
= 0; i
< size
; i
++) {
4428 if (new->entries
[i
].threshold
<= usage
) {
4430 * new->current_threshold will not be used until
4431 * rcu_assign_pointer(), so it's safe to increment
4434 ++new->current_threshold
;
4439 /* Free old spare buffer and save old primary buffer as spare */
4440 kfree(thresholds
->spare
);
4441 thresholds
->spare
= thresholds
->primary
;
4443 rcu_assign_pointer(thresholds
->primary
, new);
4445 /* To be sure that nobody uses thresholds */
4449 mutex_unlock(&memcg
->thresholds_lock
);
4454 static void mem_cgroup_usage_unregister_event(struct cgroup
*cgrp
,
4455 struct cftype
*cft
, struct eventfd_ctx
*eventfd
)
4457 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cgrp
);
4458 struct mem_cgroup_thresholds
*thresholds
;
4459 struct mem_cgroup_threshold_ary
*new;
4460 int type
= MEMFILE_TYPE(cft
->private);
4464 mutex_lock(&memcg
->thresholds_lock
);
4466 thresholds
= &memcg
->thresholds
;
4467 else if (type
== _MEMSWAP
)
4468 thresholds
= &memcg
->memsw_thresholds
;
4472 if (!thresholds
->primary
)
4475 usage
= mem_cgroup_usage(memcg
, type
== _MEMSWAP
);
4477 /* Check if a threshold crossed before removing */
4478 __mem_cgroup_threshold(memcg
, type
== _MEMSWAP
);
4480 /* Calculate new number of threshold */
4482 for (i
= 0; i
< thresholds
->primary
->size
; i
++) {
4483 if (thresholds
->primary
->entries
[i
].eventfd
!= eventfd
)
4487 new = thresholds
->spare
;
4489 /* Set thresholds array to NULL if we don't have thresholds */
4498 /* Copy thresholds and find current threshold */
4499 new->current_threshold
= -1;
4500 for (i
= 0, j
= 0; i
< thresholds
->primary
->size
; i
++) {
4501 if (thresholds
->primary
->entries
[i
].eventfd
== eventfd
)
4504 new->entries
[j
] = thresholds
->primary
->entries
[i
];
4505 if (new->entries
[j
].threshold
<= usage
) {
4507 * new->current_threshold will not be used
4508 * until rcu_assign_pointer(), so it's safe to increment
4511 ++new->current_threshold
;
4517 /* Swap primary and spare array */
4518 thresholds
->spare
= thresholds
->primary
;
4519 /* If all events are unregistered, free the spare array */
4521 kfree(thresholds
->spare
);
4522 thresholds
->spare
= NULL
;
4525 rcu_assign_pointer(thresholds
->primary
, new);
4527 /* To be sure that nobody uses thresholds */
4530 mutex_unlock(&memcg
->thresholds_lock
);
4533 static int mem_cgroup_oom_register_event(struct cgroup
*cgrp
,
4534 struct cftype
*cft
, struct eventfd_ctx
*eventfd
, const char *args
)
4536 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cgrp
);
4537 struct mem_cgroup_eventfd_list
*event
;
4538 int type
= MEMFILE_TYPE(cft
->private);
4540 BUG_ON(type
!= _OOM_TYPE
);
4541 event
= kmalloc(sizeof(*event
), GFP_KERNEL
);
4545 spin_lock(&memcg_oom_lock
);
4547 event
->eventfd
= eventfd
;
4548 list_add(&event
->list
, &memcg
->oom_notify
);
4550 /* already in OOM ? */
4551 if (atomic_read(&memcg
->under_oom
))
4552 eventfd_signal(eventfd
, 1);
4553 spin_unlock(&memcg_oom_lock
);
4558 static void mem_cgroup_oom_unregister_event(struct cgroup
*cgrp
,
4559 struct cftype
*cft
, struct eventfd_ctx
*eventfd
)
4561 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cgrp
);
4562 struct mem_cgroup_eventfd_list
*ev
, *tmp
;
4563 int type
= MEMFILE_TYPE(cft
->private);
4565 BUG_ON(type
!= _OOM_TYPE
);
4567 spin_lock(&memcg_oom_lock
);
4569 list_for_each_entry_safe(ev
, tmp
, &memcg
->oom_notify
, list
) {
4570 if (ev
->eventfd
== eventfd
) {
4571 list_del(&ev
->list
);
4576 spin_unlock(&memcg_oom_lock
);
4579 static int mem_cgroup_oom_control_read(struct cgroup
*cgrp
,
4580 struct cftype
*cft
, struct cgroup_map_cb
*cb
)
4582 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cgrp
);
4584 cb
->fill(cb
, "oom_kill_disable", memcg
->oom_kill_disable
);
4586 if (atomic_read(&memcg
->under_oom
))
4587 cb
->fill(cb
, "under_oom", 1);
4589 cb
->fill(cb
, "under_oom", 0);
4593 static int mem_cgroup_oom_control_write(struct cgroup
*cgrp
,
4594 struct cftype
*cft
, u64 val
)
4596 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cgrp
);
4597 struct mem_cgroup
*parent
;
4599 /* cannot set to root cgroup and only 0 and 1 are allowed */
4600 if (!cgrp
->parent
|| !((val
== 0) || (val
== 1)))
4603 parent
= mem_cgroup_from_cont(cgrp
->parent
);
4606 /* oom-kill-disable is a flag for subhierarchy. */
4607 if ((parent
->use_hierarchy
) ||
4608 (memcg
->use_hierarchy
&& !list_empty(&cgrp
->children
))) {
4612 memcg
->oom_kill_disable
= val
;
4614 memcg_oom_recover(memcg
);
4620 static const struct file_operations mem_control_numa_stat_file_operations
= {
4622 .llseek
= seq_lseek
,
4623 .release
= single_release
,
4626 static int mem_control_numa_stat_open(struct inode
*unused
, struct file
*file
)
4628 struct cgroup
*cont
= file
->f_dentry
->d_parent
->d_fsdata
;
4630 file
->f_op
= &mem_control_numa_stat_file_operations
;
4631 return single_open(file
, mem_control_numa_stat_show
, cont
);
4633 #endif /* CONFIG_NUMA */
4635 #ifdef CONFIG_CGROUP_MEM_RES_CTLR_KMEM
4636 static int memcg_init_kmem(struct mem_cgroup
*memcg
, struct cgroup_subsys
*ss
)
4638 return mem_cgroup_sockets_init(memcg
, ss
);
4641 static void kmem_cgroup_destroy(struct mem_cgroup
*memcg
)
4643 mem_cgroup_sockets_destroy(memcg
);
4646 static int memcg_init_kmem(struct mem_cgroup
*memcg
, struct cgroup_subsys
*ss
)
4651 static void kmem_cgroup_destroy(struct mem_cgroup
*memcg
)
4656 static struct cftype mem_cgroup_files
[] = {
4658 .name
= "usage_in_bytes",
4659 .private = MEMFILE_PRIVATE(_MEM
, RES_USAGE
),
4660 .read
= mem_cgroup_read
,
4661 .register_event
= mem_cgroup_usage_register_event
,
4662 .unregister_event
= mem_cgroup_usage_unregister_event
,
4665 .name
= "max_usage_in_bytes",
4666 .private = MEMFILE_PRIVATE(_MEM
, RES_MAX_USAGE
),
4667 .trigger
= mem_cgroup_reset
,
4668 .read
= mem_cgroup_read
,
4671 .name
= "limit_in_bytes",
4672 .private = MEMFILE_PRIVATE(_MEM
, RES_LIMIT
),
4673 .write_string
= mem_cgroup_write
,
4674 .read
= mem_cgroup_read
,
4677 .name
= "soft_limit_in_bytes",
4678 .private = MEMFILE_PRIVATE(_MEM
, RES_SOFT_LIMIT
),
4679 .write_string
= mem_cgroup_write
,
4680 .read
= mem_cgroup_read
,
4684 .private = MEMFILE_PRIVATE(_MEM
, RES_FAILCNT
),
4685 .trigger
= mem_cgroup_reset
,
4686 .read
= mem_cgroup_read
,
4690 .read_map
= mem_control_stat_show
,
4693 .name
= "force_empty",
4694 .trigger
= mem_cgroup_force_empty_write
,
4697 .name
= "use_hierarchy",
4698 .write_u64
= mem_cgroup_hierarchy_write
,
4699 .read_u64
= mem_cgroup_hierarchy_read
,
4702 .name
= "swappiness",
4703 .read_u64
= mem_cgroup_swappiness_read
,
4704 .write_u64
= mem_cgroup_swappiness_write
,
4707 .name
= "move_charge_at_immigrate",
4708 .read_u64
= mem_cgroup_move_charge_read
,
4709 .write_u64
= mem_cgroup_move_charge_write
,
4712 .name
= "oom_control",
4713 .read_map
= mem_cgroup_oom_control_read
,
4714 .write_u64
= mem_cgroup_oom_control_write
,
4715 .register_event
= mem_cgroup_oom_register_event
,
4716 .unregister_event
= mem_cgroup_oom_unregister_event
,
4717 .private = MEMFILE_PRIVATE(_OOM_TYPE
, OOM_CONTROL
),
4721 .name
= "numa_stat",
4722 .open
= mem_control_numa_stat_open
,
4726 #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP
4728 .name
= "memsw.usage_in_bytes",
4729 .private = MEMFILE_PRIVATE(_MEMSWAP
, RES_USAGE
),
4730 .read
= mem_cgroup_read
,
4731 .register_event
= mem_cgroup_usage_register_event
,
4732 .unregister_event
= mem_cgroup_usage_unregister_event
,
4735 .name
= "memsw.max_usage_in_bytes",
4736 .private = MEMFILE_PRIVATE(_MEMSWAP
, RES_MAX_USAGE
),
4737 .trigger
= mem_cgroup_reset
,
4738 .read
= mem_cgroup_read
,
4741 .name
= "memsw.limit_in_bytes",
4742 .private = MEMFILE_PRIVATE(_MEMSWAP
, RES_LIMIT
),
4743 .write_string
= mem_cgroup_write
,
4744 .read
= mem_cgroup_read
,
4747 .name
= "memsw.failcnt",
4748 .private = MEMFILE_PRIVATE(_MEMSWAP
, RES_FAILCNT
),
4749 .trigger
= mem_cgroup_reset
,
4750 .read
= mem_cgroup_read
,
4753 { }, /* terminate */
4756 static int alloc_mem_cgroup_per_zone_info(struct mem_cgroup
*memcg
, int node
)
4758 struct mem_cgroup_per_node
*pn
;
4759 struct mem_cgroup_per_zone
*mz
;
4760 int zone
, tmp
= node
;
4762 * This routine is called against possible nodes.
4763 * But it's BUG to call kmalloc() against offline node.
4765 * TODO: this routine can waste much memory for nodes which will
4766 * never be onlined. It's better to use memory hotplug callback
4769 if (!node_state(node
, N_NORMAL_MEMORY
))
4771 pn
= kzalloc_node(sizeof(*pn
), GFP_KERNEL
, tmp
);
4775 for (zone
= 0; zone
< MAX_NR_ZONES
; zone
++) {
4776 mz
= &pn
->zoneinfo
[zone
];
4777 lruvec_init(&mz
->lruvec
, &NODE_DATA(node
)->node_zones
[zone
]);
4778 mz
->usage_in_excess
= 0;
4779 mz
->on_tree
= false;
4782 memcg
->info
.nodeinfo
[node
] = pn
;
4786 static void free_mem_cgroup_per_zone_info(struct mem_cgroup
*memcg
, int node
)
4788 kfree(memcg
->info
.nodeinfo
[node
]);
4791 static struct mem_cgroup
*mem_cgroup_alloc(void)
4793 struct mem_cgroup
*memcg
;
4794 int size
= sizeof(struct mem_cgroup
);
4796 /* Can be very big if MAX_NUMNODES is very big */
4797 if (size
< PAGE_SIZE
)
4798 memcg
= kzalloc(size
, GFP_KERNEL
);
4800 memcg
= vzalloc(size
);
4805 memcg
->stat
= alloc_percpu(struct mem_cgroup_stat_cpu
);
4808 spin_lock_init(&memcg
->pcp_counter_lock
);
4812 if (size
< PAGE_SIZE
)
4820 * Helpers for freeing a vzalloc()ed mem_cgroup by RCU,
4821 * but in process context. The work_freeing structure is overlaid
4822 * on the rcu_freeing structure, which itself is overlaid on memsw.
4824 static void vfree_work(struct work_struct
*work
)
4826 struct mem_cgroup
*memcg
;
4828 memcg
= container_of(work
, struct mem_cgroup
, work_freeing
);
4831 static void vfree_rcu(struct rcu_head
*rcu_head
)
4833 struct mem_cgroup
*memcg
;
4835 memcg
= container_of(rcu_head
, struct mem_cgroup
, rcu_freeing
);
4836 INIT_WORK(&memcg
->work_freeing
, vfree_work
);
4837 schedule_work(&memcg
->work_freeing
);
4841 * At destroying mem_cgroup, references from swap_cgroup can remain.
4842 * (scanning all at force_empty is too costly...)
4844 * Instead of clearing all references at force_empty, we remember
4845 * the number of reference from swap_cgroup and free mem_cgroup when
4846 * it goes down to 0.
4848 * Removal of cgroup itself succeeds regardless of refs from swap.
4851 static void __mem_cgroup_free(struct mem_cgroup
*memcg
)
4855 mem_cgroup_remove_from_trees(memcg
);
4856 free_css_id(&mem_cgroup_subsys
, &memcg
->css
);
4859 free_mem_cgroup_per_zone_info(memcg
, node
);
4861 free_percpu(memcg
->stat
);
4862 if (sizeof(struct mem_cgroup
) < PAGE_SIZE
)
4863 kfree_rcu(memcg
, rcu_freeing
);
4865 call_rcu(&memcg
->rcu_freeing
, vfree_rcu
);
4868 static void mem_cgroup_get(struct mem_cgroup
*memcg
)
4870 atomic_inc(&memcg
->refcnt
);
4873 static void __mem_cgroup_put(struct mem_cgroup
*memcg
, int count
)
4875 if (atomic_sub_and_test(count
, &memcg
->refcnt
)) {
4876 struct mem_cgroup
*parent
= parent_mem_cgroup(memcg
);
4877 __mem_cgroup_free(memcg
);
4879 mem_cgroup_put(parent
);
4883 static void mem_cgroup_put(struct mem_cgroup
*memcg
)
4885 __mem_cgroup_put(memcg
, 1);
4889 * Returns the parent mem_cgroup in memcgroup hierarchy with hierarchy enabled.
4891 struct mem_cgroup
*parent_mem_cgroup(struct mem_cgroup
*memcg
)
4893 if (!memcg
->res
.parent
)
4895 return mem_cgroup_from_res_counter(memcg
->res
.parent
, res
);
4897 EXPORT_SYMBOL(parent_mem_cgroup
);
4899 #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP
4900 static void __init
enable_swap_cgroup(void)
4902 if (!mem_cgroup_disabled() && really_do_swap_account
)
4903 do_swap_account
= 1;
4906 static void __init
enable_swap_cgroup(void)
4911 static int mem_cgroup_soft_limit_tree_init(void)
4913 struct mem_cgroup_tree_per_node
*rtpn
;
4914 struct mem_cgroup_tree_per_zone
*rtpz
;
4915 int tmp
, node
, zone
;
4917 for_each_node(node
) {
4919 if (!node_state(node
, N_NORMAL_MEMORY
))
4921 rtpn
= kzalloc_node(sizeof(*rtpn
), GFP_KERNEL
, tmp
);
4925 soft_limit_tree
.rb_tree_per_node
[node
] = rtpn
;
4927 for (zone
= 0; zone
< MAX_NR_ZONES
; zone
++) {
4928 rtpz
= &rtpn
->rb_tree_per_zone
[zone
];
4929 rtpz
->rb_root
= RB_ROOT
;
4930 spin_lock_init(&rtpz
->lock
);
4936 for_each_node(node
) {
4937 if (!soft_limit_tree
.rb_tree_per_node
[node
])
4939 kfree(soft_limit_tree
.rb_tree_per_node
[node
]);
4940 soft_limit_tree
.rb_tree_per_node
[node
] = NULL
;
4946 static struct cgroup_subsys_state
* __ref
4947 mem_cgroup_create(struct cgroup
*cont
)
4949 struct mem_cgroup
*memcg
, *parent
;
4950 long error
= -ENOMEM
;
4953 memcg
= mem_cgroup_alloc();
4955 return ERR_PTR(error
);
4958 if (alloc_mem_cgroup_per_zone_info(memcg
, node
))
4962 if (cont
->parent
== NULL
) {
4964 enable_swap_cgroup();
4966 if (mem_cgroup_soft_limit_tree_init())
4968 root_mem_cgroup
= memcg
;
4969 for_each_possible_cpu(cpu
) {
4970 struct memcg_stock_pcp
*stock
=
4971 &per_cpu(memcg_stock
, cpu
);
4972 INIT_WORK(&stock
->work
, drain_local_stock
);
4974 hotcpu_notifier(memcg_cpu_hotplug_callback
, 0);
4976 parent
= mem_cgroup_from_cont(cont
->parent
);
4977 memcg
->use_hierarchy
= parent
->use_hierarchy
;
4978 memcg
->oom_kill_disable
= parent
->oom_kill_disable
;
4981 if (parent
&& parent
->use_hierarchy
) {
4982 res_counter_init(&memcg
->res
, &parent
->res
);
4983 res_counter_init(&memcg
->memsw
, &parent
->memsw
);
4985 * We increment refcnt of the parent to ensure that we can
4986 * safely access it on res_counter_charge/uncharge.
4987 * This refcnt will be decremented when freeing this
4988 * mem_cgroup(see mem_cgroup_put).
4990 mem_cgroup_get(parent
);
4992 res_counter_init(&memcg
->res
, NULL
);
4993 res_counter_init(&memcg
->memsw
, NULL
);
4995 memcg
->last_scanned_node
= MAX_NUMNODES
;
4996 INIT_LIST_HEAD(&memcg
->oom_notify
);
4999 memcg
->swappiness
= mem_cgroup_swappiness(parent
);
5000 atomic_set(&memcg
->refcnt
, 1);
5001 memcg
->move_charge_at_immigrate
= 0;
5002 mutex_init(&memcg
->thresholds_lock
);
5003 spin_lock_init(&memcg
->move_lock
);
5005 error
= memcg_init_kmem(memcg
, &mem_cgroup_subsys
);
5008 * We call put now because our (and parent's) refcnts
5009 * are already in place. mem_cgroup_put() will internally
5010 * call __mem_cgroup_free, so return directly
5012 mem_cgroup_put(memcg
);
5013 return ERR_PTR(error
);
5017 __mem_cgroup_free(memcg
);
5018 return ERR_PTR(error
);
5021 static int mem_cgroup_pre_destroy(struct cgroup
*cont
)
5023 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cont
);
5025 return mem_cgroup_force_empty(memcg
, false);
5028 static void mem_cgroup_destroy(struct cgroup
*cont
)
5030 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cont
);
5032 kmem_cgroup_destroy(memcg
);
5034 mem_cgroup_put(memcg
);
5038 /* Handlers for move charge at task migration. */
5039 #define PRECHARGE_COUNT_AT_ONCE 256
5040 static int mem_cgroup_do_precharge(unsigned long count
)
5043 int batch_count
= PRECHARGE_COUNT_AT_ONCE
;
5044 struct mem_cgroup
*memcg
= mc
.to
;
5046 if (mem_cgroup_is_root(memcg
)) {
5047 mc
.precharge
+= count
;
5048 /* we don't need css_get for root */
5051 /* try to charge at once */
5053 struct res_counter
*dummy
;
5055 * "memcg" cannot be under rmdir() because we've already checked
5056 * by cgroup_lock_live_cgroup() that it is not removed and we
5057 * are still under the same cgroup_mutex. So we can postpone
5060 if (res_counter_charge(&memcg
->res
, PAGE_SIZE
* count
, &dummy
))
5062 if (do_swap_account
&& res_counter_charge(&memcg
->memsw
,
5063 PAGE_SIZE
* count
, &dummy
)) {
5064 res_counter_uncharge(&memcg
->res
, PAGE_SIZE
* count
);
5067 mc
.precharge
+= count
;
5071 /* fall back to one by one charge */
5073 if (signal_pending(current
)) {
5077 if (!batch_count
--) {
5078 batch_count
= PRECHARGE_COUNT_AT_ONCE
;
5081 ret
= __mem_cgroup_try_charge(NULL
,
5082 GFP_KERNEL
, 1, &memcg
, false);
5084 /* mem_cgroup_clear_mc() will do uncharge later */
5092 * get_mctgt_type - get target type of moving charge
5093 * @vma: the vma the pte to be checked belongs
5094 * @addr: the address corresponding to the pte to be checked
5095 * @ptent: the pte to be checked
5096 * @target: the pointer the target page or swap ent will be stored(can be NULL)
5099 * 0(MC_TARGET_NONE): if the pte is not a target for move charge.
5100 * 1(MC_TARGET_PAGE): if the page corresponding to this pte is a target for
5101 * move charge. if @target is not NULL, the page is stored in target->page
5102 * with extra refcnt got(Callers should handle it).
5103 * 2(MC_TARGET_SWAP): if the swap entry corresponding to this pte is a
5104 * target for charge migration. if @target is not NULL, the entry is stored
5107 * Called with pte lock held.
5114 enum mc_target_type
{
5120 static struct page
*mc_handle_present_pte(struct vm_area_struct
*vma
,
5121 unsigned long addr
, pte_t ptent
)
5123 struct page
*page
= vm_normal_page(vma
, addr
, ptent
);
5125 if (!page
|| !page_mapped(page
))
5127 if (PageAnon(page
)) {
5128 /* we don't move shared anon */
5131 } else if (!move_file())
5132 /* we ignore mapcount for file pages */
5134 if (!get_page_unless_zero(page
))
5141 static struct page
*mc_handle_swap_pte(struct vm_area_struct
*vma
,
5142 unsigned long addr
, pte_t ptent
, swp_entry_t
*entry
)
5144 struct page
*page
= NULL
;
5145 swp_entry_t ent
= pte_to_swp_entry(ptent
);
5147 if (!move_anon() || non_swap_entry(ent
))
5150 * Because lookup_swap_cache() updates some statistics counter,
5151 * we call find_get_page() with swapper_space directly.
5153 page
= find_get_page(&swapper_space
, ent
.val
);
5154 if (do_swap_account
)
5155 entry
->val
= ent
.val
;
5160 static struct page
*mc_handle_swap_pte(struct vm_area_struct
*vma
,
5161 unsigned long addr
, pte_t ptent
, swp_entry_t
*entry
)
5167 static struct page
*mc_handle_file_pte(struct vm_area_struct
*vma
,
5168 unsigned long addr
, pte_t ptent
, swp_entry_t
*entry
)
5170 struct page
*page
= NULL
;
5171 struct address_space
*mapping
;
5174 if (!vma
->vm_file
) /* anonymous vma */
5179 mapping
= vma
->vm_file
->f_mapping
;
5180 if (pte_none(ptent
))
5181 pgoff
= linear_page_index(vma
, addr
);
5182 else /* pte_file(ptent) is true */
5183 pgoff
= pte_to_pgoff(ptent
);
5185 /* page is moved even if it's not RSS of this task(page-faulted). */
5186 page
= find_get_page(mapping
, pgoff
);
5189 /* shmem/tmpfs may report page out on swap: account for that too. */
5190 if (radix_tree_exceptional_entry(page
)) {
5191 swp_entry_t swap
= radix_to_swp_entry(page
);
5192 if (do_swap_account
)
5194 page
= find_get_page(&swapper_space
, swap
.val
);
5200 static enum mc_target_type
get_mctgt_type(struct vm_area_struct
*vma
,
5201 unsigned long addr
, pte_t ptent
, union mc_target
*target
)
5203 struct page
*page
= NULL
;
5204 struct page_cgroup
*pc
;
5205 enum mc_target_type ret
= MC_TARGET_NONE
;
5206 swp_entry_t ent
= { .val
= 0 };
5208 if (pte_present(ptent
))
5209 page
= mc_handle_present_pte(vma
, addr
, ptent
);
5210 else if (is_swap_pte(ptent
))
5211 page
= mc_handle_swap_pte(vma
, addr
, ptent
, &ent
);
5212 else if (pte_none(ptent
) || pte_file(ptent
))
5213 page
= mc_handle_file_pte(vma
, addr
, ptent
, &ent
);
5215 if (!page
&& !ent
.val
)
5218 pc
= lookup_page_cgroup(page
);
5220 * Do only loose check w/o page_cgroup lock.
5221 * mem_cgroup_move_account() checks the pc is valid or not under
5224 if (PageCgroupUsed(pc
) && pc
->mem_cgroup
== mc
.from
) {
5225 ret
= MC_TARGET_PAGE
;
5227 target
->page
= page
;
5229 if (!ret
|| !target
)
5232 /* There is a swap entry and a page doesn't exist or isn't charged */
5233 if (ent
.val
&& !ret
&&
5234 css_id(&mc
.from
->css
) == lookup_swap_cgroup_id(ent
)) {
5235 ret
= MC_TARGET_SWAP
;
5242 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
5244 * We don't consider swapping or file mapped pages because THP does not
5245 * support them for now.
5246 * Caller should make sure that pmd_trans_huge(pmd) is true.
5248 static enum mc_target_type
get_mctgt_type_thp(struct vm_area_struct
*vma
,
5249 unsigned long addr
, pmd_t pmd
, union mc_target
*target
)
5251 struct page
*page
= NULL
;
5252 struct page_cgroup
*pc
;
5253 enum mc_target_type ret
= MC_TARGET_NONE
;
5255 page
= pmd_page(pmd
);
5256 VM_BUG_ON(!page
|| !PageHead(page
));
5259 pc
= lookup_page_cgroup(page
);
5260 if (PageCgroupUsed(pc
) && pc
->mem_cgroup
== mc
.from
) {
5261 ret
= MC_TARGET_PAGE
;
5264 target
->page
= page
;
5270 static inline enum mc_target_type
get_mctgt_type_thp(struct vm_area_struct
*vma
,
5271 unsigned long addr
, pmd_t pmd
, union mc_target
*target
)
5273 return MC_TARGET_NONE
;
5277 static int mem_cgroup_count_precharge_pte_range(pmd_t
*pmd
,
5278 unsigned long addr
, unsigned long end
,
5279 struct mm_walk
*walk
)
5281 struct vm_area_struct
*vma
= walk
->private;
5285 if (pmd_trans_huge_lock(pmd
, vma
) == 1) {
5286 if (get_mctgt_type_thp(vma
, addr
, *pmd
, NULL
) == MC_TARGET_PAGE
)
5287 mc
.precharge
+= HPAGE_PMD_NR
;
5288 spin_unlock(&vma
->vm_mm
->page_table_lock
);
5292 if (pmd_trans_unstable(pmd
))
5294 pte
= pte_offset_map_lock(vma
->vm_mm
, pmd
, addr
, &ptl
);
5295 for (; addr
!= end
; pte
++, addr
+= PAGE_SIZE
)
5296 if (get_mctgt_type(vma
, addr
, *pte
, NULL
))
5297 mc
.precharge
++; /* increment precharge temporarily */
5298 pte_unmap_unlock(pte
- 1, ptl
);
5304 static unsigned long mem_cgroup_count_precharge(struct mm_struct
*mm
)
5306 unsigned long precharge
;
5307 struct vm_area_struct
*vma
;
5309 down_read(&mm
->mmap_sem
);
5310 for (vma
= mm
->mmap
; vma
; vma
= vma
->vm_next
) {
5311 struct mm_walk mem_cgroup_count_precharge_walk
= {
5312 .pmd_entry
= mem_cgroup_count_precharge_pte_range
,
5316 if (is_vm_hugetlb_page(vma
))
5318 walk_page_range(vma
->vm_start
, vma
->vm_end
,
5319 &mem_cgroup_count_precharge_walk
);
5321 up_read(&mm
->mmap_sem
);
5323 precharge
= mc
.precharge
;
5329 static int mem_cgroup_precharge_mc(struct mm_struct
*mm
)
5331 unsigned long precharge
= mem_cgroup_count_precharge(mm
);
5333 VM_BUG_ON(mc
.moving_task
);
5334 mc
.moving_task
= current
;
5335 return mem_cgroup_do_precharge(precharge
);
5338 /* cancels all extra charges on mc.from and mc.to, and wakes up all waiters. */
5339 static void __mem_cgroup_clear_mc(void)
5341 struct mem_cgroup
*from
= mc
.from
;
5342 struct mem_cgroup
*to
= mc
.to
;
5344 /* we must uncharge all the leftover precharges from mc.to */
5346 __mem_cgroup_cancel_charge(mc
.to
, mc
.precharge
);
5350 * we didn't uncharge from mc.from at mem_cgroup_move_account(), so
5351 * we must uncharge here.
5353 if (mc
.moved_charge
) {
5354 __mem_cgroup_cancel_charge(mc
.from
, mc
.moved_charge
);
5355 mc
.moved_charge
= 0;
5357 /* we must fixup refcnts and charges */
5358 if (mc
.moved_swap
) {
5359 /* uncharge swap account from the old cgroup */
5360 if (!mem_cgroup_is_root(mc
.from
))
5361 res_counter_uncharge(&mc
.from
->memsw
,
5362 PAGE_SIZE
* mc
.moved_swap
);
5363 __mem_cgroup_put(mc
.from
, mc
.moved_swap
);
5365 if (!mem_cgroup_is_root(mc
.to
)) {
5367 * we charged both to->res and to->memsw, so we should
5370 res_counter_uncharge(&mc
.to
->res
,
5371 PAGE_SIZE
* mc
.moved_swap
);
5373 /* we've already done mem_cgroup_get(mc.to) */
5376 memcg_oom_recover(from
);
5377 memcg_oom_recover(to
);
5378 wake_up_all(&mc
.waitq
);
5381 static void mem_cgroup_clear_mc(void)
5383 struct mem_cgroup
*from
= mc
.from
;
5386 * we must clear moving_task before waking up waiters at the end of
5389 mc
.moving_task
= NULL
;
5390 __mem_cgroup_clear_mc();
5391 spin_lock(&mc
.lock
);
5394 spin_unlock(&mc
.lock
);
5395 mem_cgroup_end_move(from
);
5398 static int mem_cgroup_can_attach(struct cgroup
*cgroup
,
5399 struct cgroup_taskset
*tset
)
5401 struct task_struct
*p
= cgroup_taskset_first(tset
);
5403 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cgroup
);
5405 if (memcg
->move_charge_at_immigrate
) {
5406 struct mm_struct
*mm
;
5407 struct mem_cgroup
*from
= mem_cgroup_from_task(p
);
5409 VM_BUG_ON(from
== memcg
);
5411 mm
= get_task_mm(p
);
5414 /* We move charges only when we move a owner of the mm */
5415 if (mm
->owner
== p
) {
5418 VM_BUG_ON(mc
.precharge
);
5419 VM_BUG_ON(mc
.moved_charge
);
5420 VM_BUG_ON(mc
.moved_swap
);
5421 mem_cgroup_start_move(from
);
5422 spin_lock(&mc
.lock
);
5425 spin_unlock(&mc
.lock
);
5426 /* We set mc.moving_task later */
5428 ret
= mem_cgroup_precharge_mc(mm
);
5430 mem_cgroup_clear_mc();
5437 static void mem_cgroup_cancel_attach(struct cgroup
*cgroup
,
5438 struct cgroup_taskset
*tset
)
5440 mem_cgroup_clear_mc();
5443 static int mem_cgroup_move_charge_pte_range(pmd_t
*pmd
,
5444 unsigned long addr
, unsigned long end
,
5445 struct mm_walk
*walk
)
5448 struct vm_area_struct
*vma
= walk
->private;
5451 enum mc_target_type target_type
;
5452 union mc_target target
;
5454 struct page_cgroup
*pc
;
5457 * We don't take compound_lock() here but no race with splitting thp
5459 * - if pmd_trans_huge_lock() returns 1, the relevant thp is not
5460 * under splitting, which means there's no concurrent thp split,
5461 * - if another thread runs into split_huge_page() just after we
5462 * entered this if-block, the thread must wait for page table lock
5463 * to be unlocked in __split_huge_page_splitting(), where the main
5464 * part of thp split is not executed yet.
5466 if (pmd_trans_huge_lock(pmd
, vma
) == 1) {
5467 if (mc
.precharge
< HPAGE_PMD_NR
) {
5468 spin_unlock(&vma
->vm_mm
->page_table_lock
);
5471 target_type
= get_mctgt_type_thp(vma
, addr
, *pmd
, &target
);
5472 if (target_type
== MC_TARGET_PAGE
) {
5474 if (!isolate_lru_page(page
)) {
5475 pc
= lookup_page_cgroup(page
);
5476 if (!mem_cgroup_move_account(page
, HPAGE_PMD_NR
,
5479 mc
.precharge
-= HPAGE_PMD_NR
;
5480 mc
.moved_charge
+= HPAGE_PMD_NR
;
5482 putback_lru_page(page
);
5486 spin_unlock(&vma
->vm_mm
->page_table_lock
);
5490 if (pmd_trans_unstable(pmd
))
5493 pte
= pte_offset_map_lock(vma
->vm_mm
, pmd
, addr
, &ptl
);
5494 for (; addr
!= end
; addr
+= PAGE_SIZE
) {
5495 pte_t ptent
= *(pte
++);
5501 switch (get_mctgt_type(vma
, addr
, ptent
, &target
)) {
5502 case MC_TARGET_PAGE
:
5504 if (isolate_lru_page(page
))
5506 pc
= lookup_page_cgroup(page
);
5507 if (!mem_cgroup_move_account(page
, 1, pc
,
5508 mc
.from
, mc
.to
, false)) {
5510 /* we uncharge from mc.from later. */
5513 putback_lru_page(page
);
5514 put
: /* get_mctgt_type() gets the page */
5517 case MC_TARGET_SWAP
:
5519 if (!mem_cgroup_move_swap_account(ent
, mc
.from
, mc
.to
)) {
5521 /* we fixup refcnts and charges later. */
5529 pte_unmap_unlock(pte
- 1, ptl
);
5534 * We have consumed all precharges we got in can_attach().
5535 * We try charge one by one, but don't do any additional
5536 * charges to mc.to if we have failed in charge once in attach()
5539 ret
= mem_cgroup_do_precharge(1);
5547 static void mem_cgroup_move_charge(struct mm_struct
*mm
)
5549 struct vm_area_struct
*vma
;
5551 lru_add_drain_all();
5553 if (unlikely(!down_read_trylock(&mm
->mmap_sem
))) {
5555 * Someone who are holding the mmap_sem might be waiting in
5556 * waitq. So we cancel all extra charges, wake up all waiters,
5557 * and retry. Because we cancel precharges, we might not be able
5558 * to move enough charges, but moving charge is a best-effort
5559 * feature anyway, so it wouldn't be a big problem.
5561 __mem_cgroup_clear_mc();
5565 for (vma
= mm
->mmap
; vma
; vma
= vma
->vm_next
) {
5567 struct mm_walk mem_cgroup_move_charge_walk
= {
5568 .pmd_entry
= mem_cgroup_move_charge_pte_range
,
5572 if (is_vm_hugetlb_page(vma
))
5574 ret
= walk_page_range(vma
->vm_start
, vma
->vm_end
,
5575 &mem_cgroup_move_charge_walk
);
5578 * means we have consumed all precharges and failed in
5579 * doing additional charge. Just abandon here.
5583 up_read(&mm
->mmap_sem
);
5586 static void mem_cgroup_move_task(struct cgroup
*cont
,
5587 struct cgroup_taskset
*tset
)
5589 struct task_struct
*p
= cgroup_taskset_first(tset
);
5590 struct mm_struct
*mm
= get_task_mm(p
);
5594 mem_cgroup_move_charge(mm
);
5598 mem_cgroup_clear_mc();
5600 #else /* !CONFIG_MMU */
5601 static int mem_cgroup_can_attach(struct cgroup
*cgroup
,
5602 struct cgroup_taskset
*tset
)
5606 static void mem_cgroup_cancel_attach(struct cgroup
*cgroup
,
5607 struct cgroup_taskset
*tset
)
5610 static void mem_cgroup_move_task(struct cgroup
*cont
,
5611 struct cgroup_taskset
*tset
)
5616 struct cgroup_subsys mem_cgroup_subsys
= {
5618 .subsys_id
= mem_cgroup_subsys_id
,
5619 .create
= mem_cgroup_create
,
5620 .pre_destroy
= mem_cgroup_pre_destroy
,
5621 .destroy
= mem_cgroup_destroy
,
5622 .can_attach
= mem_cgroup_can_attach
,
5623 .cancel_attach
= mem_cgroup_cancel_attach
,
5624 .attach
= mem_cgroup_move_task
,
5625 .base_cftypes
= mem_cgroup_files
,
5628 .__DEPRECATED_clear_css_refs
= true,
5631 #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP
5632 static int __init
enable_swap_account(char *s
)
5634 /* consider enabled if no parameter or 1 is given */
5635 if (!strcmp(s
, "1"))
5636 really_do_swap_account
= 1;
5637 else if (!strcmp(s
, "0"))
5638 really_do_swap_account
= 0;
5641 __setup("swapaccount=", enable_swap_account
);