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 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_ON_MOVE
, /* someone is moving account between groups */
93 MEM_CGROUP_STAT_NSTATS
,
96 enum mem_cgroup_events_index
{
97 MEM_CGROUP_EVENTS_PGPGIN
, /* # of pages paged in */
98 MEM_CGROUP_EVENTS_PGPGOUT
, /* # of pages paged out */
99 MEM_CGROUP_EVENTS_COUNT
, /* # of pages paged in/out */
100 MEM_CGROUP_EVENTS_PGFAULT
, /* # of page-faults */
101 MEM_CGROUP_EVENTS_PGMAJFAULT
, /* # of major page-faults */
102 MEM_CGROUP_EVENTS_NSTATS
,
105 * Per memcg event counter is incremented at every pagein/pageout. With THP,
106 * it will be incremated by the number of pages. This counter is used for
107 * for trigger some periodic events. This is straightforward and better
108 * than using jiffies etc. to handle periodic memcg event.
110 enum mem_cgroup_events_target
{
111 MEM_CGROUP_TARGET_THRESH
,
112 MEM_CGROUP_TARGET_SOFTLIMIT
,
113 MEM_CGROUP_TARGET_NUMAINFO
,
116 #define THRESHOLDS_EVENTS_TARGET (128)
117 #define SOFTLIMIT_EVENTS_TARGET (1024)
118 #define NUMAINFO_EVENTS_TARGET (1024)
120 struct mem_cgroup_stat_cpu
{
121 long count
[MEM_CGROUP_STAT_NSTATS
];
122 unsigned long events
[MEM_CGROUP_EVENTS_NSTATS
];
123 unsigned long targets
[MEM_CGROUP_NTARGETS
];
126 struct mem_cgroup_reclaim_iter
{
127 /* css_id of the last scanned hierarchy member */
129 /* scan generation, increased every round-trip */
130 unsigned int generation
;
134 * per-zone information in memory controller.
136 struct mem_cgroup_per_zone
{
137 struct lruvec lruvec
;
138 unsigned long lru_size
[NR_LRU_LISTS
];
140 struct mem_cgroup_reclaim_iter reclaim_iter
[DEF_PRIORITY
+ 1];
142 struct zone_reclaim_stat reclaim_stat
;
143 struct rb_node tree_node
; /* RB tree node */
144 unsigned long long usage_in_excess
;/* Set to the value by which */
145 /* the soft limit is exceeded*/
147 struct mem_cgroup
*memcg
; /* Back pointer, we cannot */
148 /* use container_of */
151 struct mem_cgroup_per_node
{
152 struct mem_cgroup_per_zone zoneinfo
[MAX_NR_ZONES
];
155 struct mem_cgroup_lru_info
{
156 struct mem_cgroup_per_node
*nodeinfo
[MAX_NUMNODES
];
160 * Cgroups above their limits are maintained in a RB-Tree, independent of
161 * their hierarchy representation
164 struct mem_cgroup_tree_per_zone
{
165 struct rb_root rb_root
;
169 struct mem_cgroup_tree_per_node
{
170 struct mem_cgroup_tree_per_zone rb_tree_per_zone
[MAX_NR_ZONES
];
173 struct mem_cgroup_tree
{
174 struct mem_cgroup_tree_per_node
*rb_tree_per_node
[MAX_NUMNODES
];
177 static struct mem_cgroup_tree soft_limit_tree __read_mostly
;
179 struct mem_cgroup_threshold
{
180 struct eventfd_ctx
*eventfd
;
185 struct mem_cgroup_threshold_ary
{
186 /* An array index points to threshold just below usage. */
187 int current_threshold
;
188 /* Size of entries[] */
190 /* Array of thresholds */
191 struct mem_cgroup_threshold entries
[0];
194 struct mem_cgroup_thresholds
{
195 /* Primary thresholds array */
196 struct mem_cgroup_threshold_ary
*primary
;
198 * Spare threshold array.
199 * This is needed to make mem_cgroup_unregister_event() "never fail".
200 * It must be able to store at least primary->size - 1 entries.
202 struct mem_cgroup_threshold_ary
*spare
;
206 struct mem_cgroup_eventfd_list
{
207 struct list_head list
;
208 struct eventfd_ctx
*eventfd
;
211 static void mem_cgroup_threshold(struct mem_cgroup
*memcg
);
212 static void mem_cgroup_oom_notify(struct mem_cgroup
*memcg
);
215 * The memory controller data structure. The memory controller controls both
216 * page cache and RSS per cgroup. We would eventually like to provide
217 * statistics based on the statistics developed by Rik Van Riel for clock-pro,
218 * to help the administrator determine what knobs to tune.
220 * TODO: Add a water mark for the memory controller. Reclaim will begin when
221 * we hit the water mark. May be even add a low water mark, such that
222 * no reclaim occurs from a cgroup at it's low water mark, this is
223 * a feature that will be implemented much later in the future.
226 struct cgroup_subsys_state css
;
228 * the counter to account for memory usage
230 struct res_counter res
;
234 * the counter to account for mem+swap usage.
236 struct res_counter memsw
;
239 * rcu_freeing is used only when freeing struct mem_cgroup,
240 * so put it into a union to avoid wasting more memory.
241 * It must be disjoint from the css field. It could be
242 * in a union with the res field, but res plays a much
243 * larger part in mem_cgroup life than memsw, and might
244 * be of interest, even at time of free, when debugging.
245 * So share rcu_head with the less interesting memsw.
247 struct rcu_head rcu_freeing
;
249 * But when using vfree(), that cannot be done at
250 * interrupt time, so we must then queue the work.
252 struct work_struct work_freeing
;
256 * Per cgroup active and inactive list, similar to the
257 * per zone LRU lists.
259 struct mem_cgroup_lru_info info
;
260 int last_scanned_node
;
262 nodemask_t scan_nodes
;
263 atomic_t numainfo_events
;
264 atomic_t numainfo_updating
;
267 * Should the accounting and control be hierarchical, per subtree?
277 /* OOM-Killer disable */
278 int oom_kill_disable
;
280 /* set when res.limit == memsw.limit */
281 bool memsw_is_minimum
;
283 /* protect arrays of thresholds */
284 struct mutex thresholds_lock
;
286 /* thresholds for memory usage. RCU-protected */
287 struct mem_cgroup_thresholds thresholds
;
289 /* thresholds for mem+swap usage. RCU-protected */
290 struct mem_cgroup_thresholds memsw_thresholds
;
292 /* For oom notifier event fd */
293 struct list_head oom_notify
;
296 * Should we move charges of a task when a task is moved into this
297 * mem_cgroup ? And what type of charges should we move ?
299 unsigned long move_charge_at_immigrate
;
303 struct mem_cgroup_stat_cpu
*stat
;
305 * used when a cpu is offlined or other synchronizations
306 * See mem_cgroup_read_stat().
308 struct mem_cgroup_stat_cpu nocpu_base
;
309 spinlock_t pcp_counter_lock
;
312 struct tcp_memcontrol tcp_mem
;
316 /* Stuffs for move charges at task migration. */
318 * Types of charges to be moved. "move_charge_at_immitgrate" is treated as a
319 * left-shifted bitmap of these types.
322 MOVE_CHARGE_TYPE_ANON
, /* private anonymous page and swap of it */
323 MOVE_CHARGE_TYPE_FILE
, /* file page(including tmpfs) and swap of it */
327 /* "mc" and its members are protected by cgroup_mutex */
328 static struct move_charge_struct
{
329 spinlock_t lock
; /* for from, to */
330 struct mem_cgroup
*from
;
331 struct mem_cgroup
*to
;
332 unsigned long precharge
;
333 unsigned long moved_charge
;
334 unsigned long moved_swap
;
335 struct task_struct
*moving_task
; /* a task moving charges */
336 wait_queue_head_t waitq
; /* a waitq for other context */
338 .lock
= __SPIN_LOCK_UNLOCKED(mc
.lock
),
339 .waitq
= __WAIT_QUEUE_HEAD_INITIALIZER(mc
.waitq
),
342 static bool move_anon(void)
344 return test_bit(MOVE_CHARGE_TYPE_ANON
,
345 &mc
.to
->move_charge_at_immigrate
);
348 static bool move_file(void)
350 return test_bit(MOVE_CHARGE_TYPE_FILE
,
351 &mc
.to
->move_charge_at_immigrate
);
355 * Maximum loops in mem_cgroup_hierarchical_reclaim(), used for soft
356 * limit reclaim to prevent infinite loops, if they ever occur.
358 #define MEM_CGROUP_MAX_RECLAIM_LOOPS (100)
359 #define MEM_CGROUP_MAX_SOFT_LIMIT_RECLAIM_LOOPS (2)
362 MEM_CGROUP_CHARGE_TYPE_CACHE
= 0,
363 MEM_CGROUP_CHARGE_TYPE_MAPPED
,
364 MEM_CGROUP_CHARGE_TYPE_SHMEM
, /* used by page migration of shmem */
365 MEM_CGROUP_CHARGE_TYPE_FORCE
, /* used by force_empty */
366 MEM_CGROUP_CHARGE_TYPE_SWAPOUT
, /* for accounting swapcache */
367 MEM_CGROUP_CHARGE_TYPE_DROP
, /* a page was unused swap cache */
371 /* for encoding cft->private value on file */
374 #define _OOM_TYPE (2)
375 #define MEMFILE_PRIVATE(x, val) (((x) << 16) | (val))
376 #define MEMFILE_TYPE(val) (((val) >> 16) & 0xffff)
377 #define MEMFILE_ATTR(val) ((val) & 0xffff)
378 /* Used for OOM nofiier */
379 #define OOM_CONTROL (0)
382 * Reclaim flags for mem_cgroup_hierarchical_reclaim
384 #define MEM_CGROUP_RECLAIM_NOSWAP_BIT 0x0
385 #define MEM_CGROUP_RECLAIM_NOSWAP (1 << MEM_CGROUP_RECLAIM_NOSWAP_BIT)
386 #define MEM_CGROUP_RECLAIM_SHRINK_BIT 0x1
387 #define MEM_CGROUP_RECLAIM_SHRINK (1 << MEM_CGROUP_RECLAIM_SHRINK_BIT)
389 static void mem_cgroup_get(struct mem_cgroup
*memcg
);
390 static void mem_cgroup_put(struct mem_cgroup
*memcg
);
392 /* Writing them here to avoid exposing memcg's inner layout */
393 #ifdef CONFIG_CGROUP_MEM_RES_CTLR_KMEM
394 #include <net/sock.h>
397 static bool mem_cgroup_is_root(struct mem_cgroup
*memcg
);
398 void sock_update_memcg(struct sock
*sk
)
400 if (mem_cgroup_sockets_enabled
) {
401 struct mem_cgroup
*memcg
;
403 BUG_ON(!sk
->sk_prot
->proto_cgroup
);
405 /* Socket cloning can throw us here with sk_cgrp already
406 * filled. It won't however, necessarily happen from
407 * process context. So the test for root memcg given
408 * the current task's memcg won't help us in this case.
410 * Respecting the original socket's memcg is a better
411 * decision in this case.
414 BUG_ON(mem_cgroup_is_root(sk
->sk_cgrp
->memcg
));
415 mem_cgroup_get(sk
->sk_cgrp
->memcg
);
420 memcg
= mem_cgroup_from_task(current
);
421 if (!mem_cgroup_is_root(memcg
)) {
422 mem_cgroup_get(memcg
);
423 sk
->sk_cgrp
= sk
->sk_prot
->proto_cgroup(memcg
);
428 EXPORT_SYMBOL(sock_update_memcg
);
430 void sock_release_memcg(struct sock
*sk
)
432 if (mem_cgroup_sockets_enabled
&& sk
->sk_cgrp
) {
433 struct mem_cgroup
*memcg
;
434 WARN_ON(!sk
->sk_cgrp
->memcg
);
435 memcg
= sk
->sk_cgrp
->memcg
;
436 mem_cgroup_put(memcg
);
441 struct cg_proto
*tcp_proto_cgroup(struct mem_cgroup
*memcg
)
443 if (!memcg
|| mem_cgroup_is_root(memcg
))
446 return &memcg
->tcp_mem
.cg_proto
;
448 EXPORT_SYMBOL(tcp_proto_cgroup
);
449 #endif /* CONFIG_INET */
450 #endif /* CONFIG_CGROUP_MEM_RES_CTLR_KMEM */
452 static void drain_all_stock_async(struct mem_cgroup
*memcg
);
454 static struct mem_cgroup_per_zone
*
455 mem_cgroup_zoneinfo(struct mem_cgroup
*memcg
, int nid
, int zid
)
457 return &memcg
->info
.nodeinfo
[nid
]->zoneinfo
[zid
];
460 struct cgroup_subsys_state
*mem_cgroup_css(struct mem_cgroup
*memcg
)
465 static struct mem_cgroup_per_zone
*
466 page_cgroup_zoneinfo(struct mem_cgroup
*memcg
, struct page
*page
)
468 int nid
= page_to_nid(page
);
469 int zid
= page_zonenum(page
);
471 return mem_cgroup_zoneinfo(memcg
, nid
, zid
);
474 static struct mem_cgroup_tree_per_zone
*
475 soft_limit_tree_node_zone(int nid
, int zid
)
477 return &soft_limit_tree
.rb_tree_per_node
[nid
]->rb_tree_per_zone
[zid
];
480 static struct mem_cgroup_tree_per_zone
*
481 soft_limit_tree_from_page(struct page
*page
)
483 int nid
= page_to_nid(page
);
484 int zid
= page_zonenum(page
);
486 return &soft_limit_tree
.rb_tree_per_node
[nid
]->rb_tree_per_zone
[zid
];
490 __mem_cgroup_insert_exceeded(struct mem_cgroup
*memcg
,
491 struct mem_cgroup_per_zone
*mz
,
492 struct mem_cgroup_tree_per_zone
*mctz
,
493 unsigned long long new_usage_in_excess
)
495 struct rb_node
**p
= &mctz
->rb_root
.rb_node
;
496 struct rb_node
*parent
= NULL
;
497 struct mem_cgroup_per_zone
*mz_node
;
502 mz
->usage_in_excess
= new_usage_in_excess
;
503 if (!mz
->usage_in_excess
)
507 mz_node
= rb_entry(parent
, struct mem_cgroup_per_zone
,
509 if (mz
->usage_in_excess
< mz_node
->usage_in_excess
)
512 * We can't avoid mem cgroups that are over their soft
513 * limit by the same amount
515 else if (mz
->usage_in_excess
>= mz_node
->usage_in_excess
)
518 rb_link_node(&mz
->tree_node
, parent
, p
);
519 rb_insert_color(&mz
->tree_node
, &mctz
->rb_root
);
524 __mem_cgroup_remove_exceeded(struct mem_cgroup
*memcg
,
525 struct mem_cgroup_per_zone
*mz
,
526 struct mem_cgroup_tree_per_zone
*mctz
)
530 rb_erase(&mz
->tree_node
, &mctz
->rb_root
);
535 mem_cgroup_remove_exceeded(struct mem_cgroup
*memcg
,
536 struct mem_cgroup_per_zone
*mz
,
537 struct mem_cgroup_tree_per_zone
*mctz
)
539 spin_lock(&mctz
->lock
);
540 __mem_cgroup_remove_exceeded(memcg
, mz
, mctz
);
541 spin_unlock(&mctz
->lock
);
545 static void mem_cgroup_update_tree(struct mem_cgroup
*memcg
, struct page
*page
)
547 unsigned long long excess
;
548 struct mem_cgroup_per_zone
*mz
;
549 struct mem_cgroup_tree_per_zone
*mctz
;
550 int nid
= page_to_nid(page
);
551 int zid
= page_zonenum(page
);
552 mctz
= soft_limit_tree_from_page(page
);
555 * Necessary to update all ancestors when hierarchy is used.
556 * because their event counter is not touched.
558 for (; memcg
; memcg
= parent_mem_cgroup(memcg
)) {
559 mz
= mem_cgroup_zoneinfo(memcg
, nid
, zid
);
560 excess
= res_counter_soft_limit_excess(&memcg
->res
);
562 * We have to update the tree if mz is on RB-tree or
563 * mem is over its softlimit.
565 if (excess
|| mz
->on_tree
) {
566 spin_lock(&mctz
->lock
);
567 /* if on-tree, remove it */
569 __mem_cgroup_remove_exceeded(memcg
, mz
, mctz
);
571 * Insert again. mz->usage_in_excess will be updated.
572 * If excess is 0, no tree ops.
574 __mem_cgroup_insert_exceeded(memcg
, mz
, mctz
, excess
);
575 spin_unlock(&mctz
->lock
);
580 static void mem_cgroup_remove_from_trees(struct mem_cgroup
*memcg
)
583 struct mem_cgroup_per_zone
*mz
;
584 struct mem_cgroup_tree_per_zone
*mctz
;
586 for_each_node(node
) {
587 for (zone
= 0; zone
< MAX_NR_ZONES
; zone
++) {
588 mz
= mem_cgroup_zoneinfo(memcg
, node
, zone
);
589 mctz
= soft_limit_tree_node_zone(node
, zone
);
590 mem_cgroup_remove_exceeded(memcg
, mz
, mctz
);
595 static struct mem_cgroup_per_zone
*
596 __mem_cgroup_largest_soft_limit_node(struct mem_cgroup_tree_per_zone
*mctz
)
598 struct rb_node
*rightmost
= NULL
;
599 struct mem_cgroup_per_zone
*mz
;
603 rightmost
= rb_last(&mctz
->rb_root
);
605 goto done
; /* Nothing to reclaim from */
607 mz
= rb_entry(rightmost
, struct mem_cgroup_per_zone
, tree_node
);
609 * Remove the node now but someone else can add it back,
610 * we will to add it back at the end of reclaim to its correct
611 * position in the tree.
613 __mem_cgroup_remove_exceeded(mz
->memcg
, mz
, mctz
);
614 if (!res_counter_soft_limit_excess(&mz
->memcg
->res
) ||
615 !css_tryget(&mz
->memcg
->css
))
621 static struct mem_cgroup_per_zone
*
622 mem_cgroup_largest_soft_limit_node(struct mem_cgroup_tree_per_zone
*mctz
)
624 struct mem_cgroup_per_zone
*mz
;
626 spin_lock(&mctz
->lock
);
627 mz
= __mem_cgroup_largest_soft_limit_node(mctz
);
628 spin_unlock(&mctz
->lock
);
633 * Implementation Note: reading percpu statistics for memcg.
635 * Both of vmstat[] and percpu_counter has threshold and do periodic
636 * synchronization to implement "quick" read. There are trade-off between
637 * reading cost and precision of value. Then, we may have a chance to implement
638 * a periodic synchronizion of counter in memcg's counter.
640 * But this _read() function is used for user interface now. The user accounts
641 * memory usage by memory cgroup and he _always_ requires exact value because
642 * he accounts memory. Even if we provide quick-and-fuzzy read, we always
643 * have to visit all online cpus and make sum. So, for now, unnecessary
644 * synchronization is not implemented. (just implemented for cpu hotplug)
646 * If there are kernel internal actions which can make use of some not-exact
647 * value, and reading all cpu value can be performance bottleneck in some
648 * common workload, threashold and synchonization as vmstat[] should be
651 static long mem_cgroup_read_stat(struct mem_cgroup
*memcg
,
652 enum mem_cgroup_stat_index idx
)
658 for_each_online_cpu(cpu
)
659 val
+= per_cpu(memcg
->stat
->count
[idx
], cpu
);
660 #ifdef CONFIG_HOTPLUG_CPU
661 spin_lock(&memcg
->pcp_counter_lock
);
662 val
+= memcg
->nocpu_base
.count
[idx
];
663 spin_unlock(&memcg
->pcp_counter_lock
);
669 static void mem_cgroup_swap_statistics(struct mem_cgroup
*memcg
,
672 int val
= (charge
) ? 1 : -1;
673 this_cpu_add(memcg
->stat
->count
[MEM_CGROUP_STAT_SWAPOUT
], val
);
676 static unsigned long mem_cgroup_read_events(struct mem_cgroup
*memcg
,
677 enum mem_cgroup_events_index idx
)
679 unsigned long val
= 0;
682 for_each_online_cpu(cpu
)
683 val
+= per_cpu(memcg
->stat
->events
[idx
], cpu
);
684 #ifdef CONFIG_HOTPLUG_CPU
685 spin_lock(&memcg
->pcp_counter_lock
);
686 val
+= memcg
->nocpu_base
.events
[idx
];
687 spin_unlock(&memcg
->pcp_counter_lock
);
692 static void mem_cgroup_charge_statistics(struct mem_cgroup
*memcg
,
693 bool anon
, int nr_pages
)
698 * Here, RSS means 'mapped anon' and anon's SwapCache. Shmem/tmpfs is
699 * counted as CACHE even if it's on ANON LRU.
702 __this_cpu_add(memcg
->stat
->count
[MEM_CGROUP_STAT_RSS
],
705 __this_cpu_add(memcg
->stat
->count
[MEM_CGROUP_STAT_CACHE
],
708 /* pagein of a big page is an event. So, ignore page size */
710 __this_cpu_inc(memcg
->stat
->events
[MEM_CGROUP_EVENTS_PGPGIN
]);
712 __this_cpu_inc(memcg
->stat
->events
[MEM_CGROUP_EVENTS_PGPGOUT
]);
713 nr_pages
= -nr_pages
; /* for event */
716 __this_cpu_add(memcg
->stat
->events
[MEM_CGROUP_EVENTS_COUNT
], nr_pages
);
722 mem_cgroup_zone_nr_lru_pages(struct mem_cgroup
*memcg
, int nid
, int zid
,
723 unsigned int lru_mask
)
725 struct mem_cgroup_per_zone
*mz
;
727 unsigned long ret
= 0;
729 mz
= mem_cgroup_zoneinfo(memcg
, nid
, zid
);
732 if (BIT(lru
) & lru_mask
)
733 ret
+= mz
->lru_size
[lru
];
739 mem_cgroup_node_nr_lru_pages(struct mem_cgroup
*memcg
,
740 int nid
, unsigned int lru_mask
)
745 for (zid
= 0; zid
< MAX_NR_ZONES
; zid
++)
746 total
+= mem_cgroup_zone_nr_lru_pages(memcg
,
752 static unsigned long mem_cgroup_nr_lru_pages(struct mem_cgroup
*memcg
,
753 unsigned int lru_mask
)
758 for_each_node_state(nid
, N_HIGH_MEMORY
)
759 total
+= mem_cgroup_node_nr_lru_pages(memcg
, nid
, lru_mask
);
763 static bool mem_cgroup_event_ratelimit(struct mem_cgroup
*memcg
,
764 enum mem_cgroup_events_target target
)
766 unsigned long val
, next
;
768 val
= __this_cpu_read(memcg
->stat
->events
[MEM_CGROUP_EVENTS_COUNT
]);
769 next
= __this_cpu_read(memcg
->stat
->targets
[target
]);
770 /* from time_after() in jiffies.h */
771 if ((long)next
- (long)val
< 0) {
773 case MEM_CGROUP_TARGET_THRESH
:
774 next
= val
+ THRESHOLDS_EVENTS_TARGET
;
776 case MEM_CGROUP_TARGET_SOFTLIMIT
:
777 next
= val
+ SOFTLIMIT_EVENTS_TARGET
;
779 case MEM_CGROUP_TARGET_NUMAINFO
:
780 next
= val
+ NUMAINFO_EVENTS_TARGET
;
785 __this_cpu_write(memcg
->stat
->targets
[target
], next
);
792 * Check events in order.
795 static void memcg_check_events(struct mem_cgroup
*memcg
, struct page
*page
)
798 /* threshold event is triggered in finer grain than soft limit */
799 if (unlikely(mem_cgroup_event_ratelimit(memcg
,
800 MEM_CGROUP_TARGET_THRESH
))) {
802 bool do_numainfo __maybe_unused
;
804 do_softlimit
= mem_cgroup_event_ratelimit(memcg
,
805 MEM_CGROUP_TARGET_SOFTLIMIT
);
807 do_numainfo
= mem_cgroup_event_ratelimit(memcg
,
808 MEM_CGROUP_TARGET_NUMAINFO
);
812 mem_cgroup_threshold(memcg
);
813 if (unlikely(do_softlimit
))
814 mem_cgroup_update_tree(memcg
, page
);
816 if (unlikely(do_numainfo
))
817 atomic_inc(&memcg
->numainfo_events
);
823 struct mem_cgroup
*mem_cgroup_from_cont(struct cgroup
*cont
)
825 return container_of(cgroup_subsys_state(cont
,
826 mem_cgroup_subsys_id
), struct mem_cgroup
,
830 struct mem_cgroup
*mem_cgroup_from_task(struct task_struct
*p
)
833 * mm_update_next_owner() may clear mm->owner to NULL
834 * if it races with swapoff, page migration, etc.
835 * So this can be called with p == NULL.
840 return container_of(task_subsys_state(p
, mem_cgroup_subsys_id
),
841 struct mem_cgroup
, css
);
844 struct mem_cgroup
*try_get_mem_cgroup_from_mm(struct mm_struct
*mm
)
846 struct mem_cgroup
*memcg
= NULL
;
851 * Because we have no locks, mm->owner's may be being moved to other
852 * cgroup. We use css_tryget() here even if this looks
853 * pessimistic (rather than adding locks here).
857 memcg
= mem_cgroup_from_task(rcu_dereference(mm
->owner
));
858 if (unlikely(!memcg
))
860 } while (!css_tryget(&memcg
->css
));
866 * mem_cgroup_iter - iterate over memory cgroup hierarchy
867 * @root: hierarchy root
868 * @prev: previously returned memcg, NULL on first invocation
869 * @reclaim: cookie for shared reclaim walks, NULL for full walks
871 * Returns references to children of the hierarchy below @root, or
872 * @root itself, or %NULL after a full round-trip.
874 * Caller must pass the return value in @prev on subsequent
875 * invocations for reference counting, or use mem_cgroup_iter_break()
876 * to cancel a hierarchy walk before the round-trip is complete.
878 * Reclaimers can specify a zone and a priority level in @reclaim to
879 * divide up the memcgs in the hierarchy among all concurrent
880 * reclaimers operating on the same zone and priority.
882 struct mem_cgroup
*mem_cgroup_iter(struct mem_cgroup
*root
,
883 struct mem_cgroup
*prev
,
884 struct mem_cgroup_reclaim_cookie
*reclaim
)
886 struct mem_cgroup
*memcg
= NULL
;
889 if (mem_cgroup_disabled())
893 root
= root_mem_cgroup
;
895 if (prev
&& !reclaim
)
896 id
= css_id(&prev
->css
);
898 if (prev
&& prev
!= root
)
901 if (!root
->use_hierarchy
&& root
!= root_mem_cgroup
) {
908 struct mem_cgroup_reclaim_iter
*uninitialized_var(iter
);
909 struct cgroup_subsys_state
*css
;
912 int nid
= zone_to_nid(reclaim
->zone
);
913 int zid
= zone_idx(reclaim
->zone
);
914 struct mem_cgroup_per_zone
*mz
;
916 mz
= mem_cgroup_zoneinfo(root
, nid
, zid
);
917 iter
= &mz
->reclaim_iter
[reclaim
->priority
];
918 if (prev
&& reclaim
->generation
!= iter
->generation
)
924 css
= css_get_next(&mem_cgroup_subsys
, id
+ 1, &root
->css
, &id
);
926 if (css
== &root
->css
|| css_tryget(css
))
927 memcg
= container_of(css
,
928 struct mem_cgroup
, css
);
937 else if (!prev
&& memcg
)
938 reclaim
->generation
= iter
->generation
;
948 * mem_cgroup_iter_break - abort a hierarchy walk prematurely
949 * @root: hierarchy root
950 * @prev: last visited hierarchy member as returned by mem_cgroup_iter()
952 void mem_cgroup_iter_break(struct mem_cgroup
*root
,
953 struct mem_cgroup
*prev
)
956 root
= root_mem_cgroup
;
957 if (prev
&& prev
!= root
)
962 * Iteration constructs for visiting all cgroups (under a tree). If
963 * loops are exited prematurely (break), mem_cgroup_iter_break() must
964 * be used for reference counting.
966 #define for_each_mem_cgroup_tree(iter, root) \
967 for (iter = mem_cgroup_iter(root, NULL, NULL); \
969 iter = mem_cgroup_iter(root, iter, NULL))
971 #define for_each_mem_cgroup(iter) \
972 for (iter = mem_cgroup_iter(NULL, NULL, NULL); \
974 iter = mem_cgroup_iter(NULL, iter, NULL))
976 static inline bool mem_cgroup_is_root(struct mem_cgroup
*memcg
)
978 return (memcg
== root_mem_cgroup
);
981 void mem_cgroup_count_vm_event(struct mm_struct
*mm
, enum vm_event_item idx
)
983 struct mem_cgroup
*memcg
;
989 memcg
= mem_cgroup_from_task(rcu_dereference(mm
->owner
));
990 if (unlikely(!memcg
))
995 this_cpu_inc(memcg
->stat
->events
[MEM_CGROUP_EVENTS_PGFAULT
]);
998 this_cpu_inc(memcg
->stat
->events
[MEM_CGROUP_EVENTS_PGMAJFAULT
]);
1006 EXPORT_SYMBOL(mem_cgroup_count_vm_event
);
1009 * mem_cgroup_zone_lruvec - get the lru list vector for a zone and memcg
1010 * @zone: zone of the wanted lruvec
1011 * @mem: memcg of the wanted lruvec
1013 * Returns the lru list vector holding pages for the given @zone and
1014 * @mem. This can be the global zone lruvec, if the memory controller
1017 struct lruvec
*mem_cgroup_zone_lruvec(struct zone
*zone
,
1018 struct mem_cgroup
*memcg
)
1020 struct mem_cgroup_per_zone
*mz
;
1022 if (mem_cgroup_disabled())
1023 return &zone
->lruvec
;
1025 mz
= mem_cgroup_zoneinfo(memcg
, zone_to_nid(zone
), zone_idx(zone
));
1030 * Following LRU functions are allowed to be used without PCG_LOCK.
1031 * Operations are called by routine of global LRU independently from memcg.
1032 * What we have to take care of here is validness of pc->mem_cgroup.
1034 * Changes to pc->mem_cgroup happens when
1037 * In typical case, "charge" is done before add-to-lru. Exception is SwapCache.
1038 * It is added to LRU before charge.
1039 * If PCG_USED bit is not set, page_cgroup is not added to this private LRU.
1040 * When moving account, the page is not on LRU. It's isolated.
1044 * mem_cgroup_lru_add_list - account for adding an lru page and return lruvec
1045 * @zone: zone of the page
1049 * This function accounts for @page being added to @lru, and returns
1050 * the lruvec for the given @zone and the memcg @page is charged to.
1052 * The callsite is then responsible for physically linking the page to
1053 * the returned lruvec->lists[@lru].
1055 struct lruvec
*mem_cgroup_lru_add_list(struct zone
*zone
, struct page
*page
,
1058 struct mem_cgroup_per_zone
*mz
;
1059 struct mem_cgroup
*memcg
;
1060 struct page_cgroup
*pc
;
1062 if (mem_cgroup_disabled())
1063 return &zone
->lruvec
;
1065 pc
= lookup_page_cgroup(page
);
1066 memcg
= pc
->mem_cgroup
;
1069 * Surreptitiously switch any uncharged page to root:
1070 * an uncharged page off lru does nothing to secure
1071 * its former mem_cgroup from sudden removal.
1073 * Our caller holds lru_lock, and PageCgroupUsed is updated
1074 * under page_cgroup lock: between them, they make all uses
1075 * of pc->mem_cgroup safe.
1077 if (!PageCgroupUsed(pc
) && memcg
!= root_mem_cgroup
)
1078 pc
->mem_cgroup
= memcg
= root_mem_cgroup
;
1080 mz
= page_cgroup_zoneinfo(memcg
, page
);
1081 /* compound_order() is stabilized through lru_lock */
1082 mz
->lru_size
[lru
] += 1 << compound_order(page
);
1087 * mem_cgroup_lru_del_list - account for removing an lru page
1091 * This function accounts for @page being removed from @lru.
1093 * The callsite is then responsible for physically unlinking
1096 void mem_cgroup_lru_del_list(struct page
*page
, enum lru_list lru
)
1098 struct mem_cgroup_per_zone
*mz
;
1099 struct mem_cgroup
*memcg
;
1100 struct page_cgroup
*pc
;
1102 if (mem_cgroup_disabled())
1105 pc
= lookup_page_cgroup(page
);
1106 memcg
= pc
->mem_cgroup
;
1108 mz
= page_cgroup_zoneinfo(memcg
, page
);
1109 /* huge page split is done under lru_lock. so, we have no races. */
1110 VM_BUG_ON(mz
->lru_size
[lru
] < (1 << compound_order(page
)));
1111 mz
->lru_size
[lru
] -= 1 << compound_order(page
);
1114 void mem_cgroup_lru_del(struct page
*page
)
1116 mem_cgroup_lru_del_list(page
, page_lru(page
));
1120 * mem_cgroup_lru_move_lists - account for moving a page between lrus
1121 * @zone: zone of the page
1123 * @from: current lru
1126 * This function accounts for @page being moved between the lrus @from
1127 * and @to, and returns the lruvec for the given @zone and the memcg
1128 * @page is charged to.
1130 * The callsite is then responsible for physically relinking
1131 * @page->lru to the returned lruvec->lists[@to].
1133 struct lruvec
*mem_cgroup_lru_move_lists(struct zone
*zone
,
1138 /* XXX: Optimize this, especially for @from == @to */
1139 mem_cgroup_lru_del_list(page
, from
);
1140 return mem_cgroup_lru_add_list(zone
, page
, to
);
1144 * Checks whether given mem is same or in the root_mem_cgroup's
1147 static bool mem_cgroup_same_or_subtree(const struct mem_cgroup
*root_memcg
,
1148 struct mem_cgroup
*memcg
)
1150 if (root_memcg
!= memcg
) {
1151 return (root_memcg
->use_hierarchy
&&
1152 css_is_ancestor(&memcg
->css
, &root_memcg
->css
));
1158 int task_in_mem_cgroup(struct task_struct
*task
, const struct mem_cgroup
*memcg
)
1161 struct mem_cgroup
*curr
= NULL
;
1162 struct task_struct
*p
;
1164 p
= find_lock_task_mm(task
);
1166 curr
= try_get_mem_cgroup_from_mm(p
->mm
);
1170 * All threads may have already detached their mm's, but the oom
1171 * killer still needs to detect if they have already been oom
1172 * killed to prevent needlessly killing additional tasks.
1175 curr
= mem_cgroup_from_task(task
);
1177 css_get(&curr
->css
);
1183 * We should check use_hierarchy of "memcg" not "curr". Because checking
1184 * use_hierarchy of "curr" here make this function true if hierarchy is
1185 * enabled in "curr" and "curr" is a child of "memcg" in *cgroup*
1186 * hierarchy(even if use_hierarchy is disabled in "memcg").
1188 ret
= mem_cgroup_same_or_subtree(memcg
, curr
);
1189 css_put(&curr
->css
);
1193 int mem_cgroup_inactive_anon_is_low(struct mem_cgroup
*memcg
, struct zone
*zone
)
1195 unsigned long inactive_ratio
;
1196 int nid
= zone_to_nid(zone
);
1197 int zid
= zone_idx(zone
);
1198 unsigned long inactive
;
1199 unsigned long active
;
1202 inactive
= mem_cgroup_zone_nr_lru_pages(memcg
, nid
, zid
,
1203 BIT(LRU_INACTIVE_ANON
));
1204 active
= mem_cgroup_zone_nr_lru_pages(memcg
, nid
, zid
,
1205 BIT(LRU_ACTIVE_ANON
));
1207 gb
= (inactive
+ active
) >> (30 - PAGE_SHIFT
);
1209 inactive_ratio
= int_sqrt(10 * gb
);
1213 return inactive
* inactive_ratio
< active
;
1216 int mem_cgroup_inactive_file_is_low(struct mem_cgroup
*memcg
, struct zone
*zone
)
1218 unsigned long active
;
1219 unsigned long inactive
;
1220 int zid
= zone_idx(zone
);
1221 int nid
= zone_to_nid(zone
);
1223 inactive
= mem_cgroup_zone_nr_lru_pages(memcg
, nid
, zid
,
1224 BIT(LRU_INACTIVE_FILE
));
1225 active
= mem_cgroup_zone_nr_lru_pages(memcg
, nid
, zid
,
1226 BIT(LRU_ACTIVE_FILE
));
1228 return (active
> inactive
);
1231 struct zone_reclaim_stat
*mem_cgroup_get_reclaim_stat(struct mem_cgroup
*memcg
,
1234 int nid
= zone_to_nid(zone
);
1235 int zid
= zone_idx(zone
);
1236 struct mem_cgroup_per_zone
*mz
= mem_cgroup_zoneinfo(memcg
, nid
, zid
);
1238 return &mz
->reclaim_stat
;
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
->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
;
1290 static void mem_cgroup_start_move(struct mem_cgroup
*memcg
)
1295 spin_lock(&memcg
->pcp_counter_lock
);
1296 for_each_online_cpu(cpu
)
1297 per_cpu(memcg
->stat
->count
[MEM_CGROUP_ON_MOVE
], cpu
) += 1;
1298 memcg
->nocpu_base
.count
[MEM_CGROUP_ON_MOVE
] += 1;
1299 spin_unlock(&memcg
->pcp_counter_lock
);
1305 static void mem_cgroup_end_move(struct mem_cgroup
*memcg
)
1312 spin_lock(&memcg
->pcp_counter_lock
);
1313 for_each_online_cpu(cpu
)
1314 per_cpu(memcg
->stat
->count
[MEM_CGROUP_ON_MOVE
], cpu
) -= 1;
1315 memcg
->nocpu_base
.count
[MEM_CGROUP_ON_MOVE
] -= 1;
1316 spin_unlock(&memcg
->pcp_counter_lock
);
1320 * 2 routines for checking "mem" is under move_account() or not.
1322 * mem_cgroup_stealed() - checking a cgroup is mc.from or not. This is used
1323 * for avoiding race in accounting. If true,
1324 * pc->mem_cgroup may be overwritten.
1326 * mem_cgroup_under_move() - checking a cgroup is mc.from or mc.to or
1327 * under hierarchy of moving cgroups. This is for
1328 * waiting at hith-memory prressure caused by "move".
1331 static bool mem_cgroup_stealed(struct mem_cgroup
*memcg
)
1333 VM_BUG_ON(!rcu_read_lock_held());
1334 return this_cpu_read(memcg
->stat
->count
[MEM_CGROUP_ON_MOVE
]) > 0;
1337 static bool mem_cgroup_under_move(struct mem_cgroup
*memcg
)
1339 struct mem_cgroup
*from
;
1340 struct mem_cgroup
*to
;
1343 * Unlike task_move routines, we access mc.to, mc.from not under
1344 * mutual exclusion by cgroup_mutex. Here, we take spinlock instead.
1346 spin_lock(&mc
.lock
);
1352 ret
= mem_cgroup_same_or_subtree(memcg
, from
)
1353 || mem_cgroup_same_or_subtree(memcg
, to
);
1355 spin_unlock(&mc
.lock
);
1359 static bool mem_cgroup_wait_acct_move(struct mem_cgroup
*memcg
)
1361 if (mc
.moving_task
&& current
!= mc
.moving_task
) {
1362 if (mem_cgroup_under_move(memcg
)) {
1364 prepare_to_wait(&mc
.waitq
, &wait
, TASK_INTERRUPTIBLE
);
1365 /* moving charge context might have finished. */
1368 finish_wait(&mc
.waitq
, &wait
);
1376 * mem_cgroup_print_oom_info: Called from OOM with tasklist_lock held in read mode.
1377 * @memcg: The memory cgroup that went over limit
1378 * @p: Task that is going to be killed
1380 * NOTE: @memcg and @p's mem_cgroup can be different when hierarchy is
1383 void mem_cgroup_print_oom_info(struct mem_cgroup
*memcg
, struct task_struct
*p
)
1385 struct cgroup
*task_cgrp
;
1386 struct cgroup
*mem_cgrp
;
1388 * Need a buffer in BSS, can't rely on allocations. The code relies
1389 * on the assumption that OOM is serialized for memory controller.
1390 * If this assumption is broken, revisit this code.
1392 static char memcg_name
[PATH_MAX
];
1400 mem_cgrp
= memcg
->css
.cgroup
;
1401 task_cgrp
= task_cgroup(p
, mem_cgroup_subsys_id
);
1403 ret
= cgroup_path(task_cgrp
, memcg_name
, PATH_MAX
);
1406 * Unfortunately, we are unable to convert to a useful name
1407 * But we'll still print out the usage information
1414 printk(KERN_INFO
"Task in %s killed", memcg_name
);
1417 ret
= cgroup_path(mem_cgrp
, memcg_name
, PATH_MAX
);
1425 * Continues from above, so we don't need an KERN_ level
1427 printk(KERN_CONT
" as a result of limit of %s\n", memcg_name
);
1430 printk(KERN_INFO
"memory: usage %llukB, limit %llukB, failcnt %llu\n",
1431 res_counter_read_u64(&memcg
->res
, RES_USAGE
) >> 10,
1432 res_counter_read_u64(&memcg
->res
, RES_LIMIT
) >> 10,
1433 res_counter_read_u64(&memcg
->res
, RES_FAILCNT
));
1434 printk(KERN_INFO
"memory+swap: usage %llukB, limit %llukB, "
1436 res_counter_read_u64(&memcg
->memsw
, RES_USAGE
) >> 10,
1437 res_counter_read_u64(&memcg
->memsw
, RES_LIMIT
) >> 10,
1438 res_counter_read_u64(&memcg
->memsw
, RES_FAILCNT
));
1442 * This function returns the number of memcg under hierarchy tree. Returns
1443 * 1(self count) if no children.
1445 static int mem_cgroup_count_children(struct mem_cgroup
*memcg
)
1448 struct mem_cgroup
*iter
;
1450 for_each_mem_cgroup_tree(iter
, memcg
)
1456 * Return the memory (and swap, if configured) limit for a memcg.
1458 u64
mem_cgroup_get_limit(struct mem_cgroup
*memcg
)
1463 limit
= res_counter_read_u64(&memcg
->res
, RES_LIMIT
);
1464 limit
+= total_swap_pages
<< PAGE_SHIFT
;
1466 memsw
= res_counter_read_u64(&memcg
->memsw
, RES_LIMIT
);
1468 * If memsw is finite and limits the amount of swap space available
1469 * to this memcg, return that limit.
1471 return min(limit
, memsw
);
1474 static unsigned long mem_cgroup_reclaim(struct mem_cgroup
*memcg
,
1476 unsigned long flags
)
1478 unsigned long total
= 0;
1479 bool noswap
= false;
1482 if (flags
& MEM_CGROUP_RECLAIM_NOSWAP
)
1484 if (!(flags
& MEM_CGROUP_RECLAIM_SHRINK
) && memcg
->memsw_is_minimum
)
1487 for (loop
= 0; loop
< MEM_CGROUP_MAX_RECLAIM_LOOPS
; loop
++) {
1489 drain_all_stock_async(memcg
);
1490 total
+= try_to_free_mem_cgroup_pages(memcg
, gfp_mask
, noswap
);
1492 * Allow limit shrinkers, which are triggered directly
1493 * by userspace, to catch signals and stop reclaim
1494 * after minimal progress, regardless of the margin.
1496 if (total
&& (flags
& MEM_CGROUP_RECLAIM_SHRINK
))
1498 if (mem_cgroup_margin(memcg
))
1501 * If nothing was reclaimed after two attempts, there
1502 * may be no reclaimable pages in this hierarchy.
1511 * test_mem_cgroup_node_reclaimable
1512 * @mem: the target memcg
1513 * @nid: the node ID to be checked.
1514 * @noswap : specify true here if the user wants flle only information.
1516 * This function returns whether the specified memcg contains any
1517 * reclaimable pages on a node. Returns true if there are any reclaimable
1518 * pages in the node.
1520 static bool test_mem_cgroup_node_reclaimable(struct mem_cgroup
*memcg
,
1521 int nid
, bool noswap
)
1523 if (mem_cgroup_node_nr_lru_pages(memcg
, nid
, LRU_ALL_FILE
))
1525 if (noswap
|| !total_swap_pages
)
1527 if (mem_cgroup_node_nr_lru_pages(memcg
, nid
, LRU_ALL_ANON
))
1532 #if MAX_NUMNODES > 1
1535 * Always updating the nodemask is not very good - even if we have an empty
1536 * list or the wrong list here, we can start from some node and traverse all
1537 * nodes based on the zonelist. So update the list loosely once per 10 secs.
1540 static void mem_cgroup_may_update_nodemask(struct mem_cgroup
*memcg
)
1544 * numainfo_events > 0 means there was at least NUMAINFO_EVENTS_TARGET
1545 * pagein/pageout changes since the last update.
1547 if (!atomic_read(&memcg
->numainfo_events
))
1549 if (atomic_inc_return(&memcg
->numainfo_updating
) > 1)
1552 /* make a nodemask where this memcg uses memory from */
1553 memcg
->scan_nodes
= node_states
[N_HIGH_MEMORY
];
1555 for_each_node_mask(nid
, node_states
[N_HIGH_MEMORY
]) {
1557 if (!test_mem_cgroup_node_reclaimable(memcg
, nid
, false))
1558 node_clear(nid
, memcg
->scan_nodes
);
1561 atomic_set(&memcg
->numainfo_events
, 0);
1562 atomic_set(&memcg
->numainfo_updating
, 0);
1566 * Selecting a node where we start reclaim from. Because what we need is just
1567 * reducing usage counter, start from anywhere is O,K. Considering
1568 * memory reclaim from current node, there are pros. and cons.
1570 * Freeing memory from current node means freeing memory from a node which
1571 * we'll use or we've used. So, it may make LRU bad. And if several threads
1572 * hit limits, it will see a contention on a node. But freeing from remote
1573 * node means more costs for memory reclaim because of memory latency.
1575 * Now, we use round-robin. Better algorithm is welcomed.
1577 int mem_cgroup_select_victim_node(struct mem_cgroup
*memcg
)
1581 mem_cgroup_may_update_nodemask(memcg
);
1582 node
= memcg
->last_scanned_node
;
1584 node
= next_node(node
, memcg
->scan_nodes
);
1585 if (node
== MAX_NUMNODES
)
1586 node
= first_node(memcg
->scan_nodes
);
1588 * We call this when we hit limit, not when pages are added to LRU.
1589 * No LRU may hold pages because all pages are UNEVICTABLE or
1590 * memcg is too small and all pages are not on LRU. In that case,
1591 * we use curret node.
1593 if (unlikely(node
== MAX_NUMNODES
))
1594 node
= numa_node_id();
1596 memcg
->last_scanned_node
= node
;
1601 * Check all nodes whether it contains reclaimable pages or not.
1602 * For quick scan, we make use of scan_nodes. This will allow us to skip
1603 * unused nodes. But scan_nodes is lazily updated and may not cotain
1604 * enough new information. We need to do double check.
1606 bool mem_cgroup_reclaimable(struct mem_cgroup
*memcg
, bool noswap
)
1611 * quick check...making use of scan_node.
1612 * We can skip unused nodes.
1614 if (!nodes_empty(memcg
->scan_nodes
)) {
1615 for (nid
= first_node(memcg
->scan_nodes
);
1617 nid
= next_node(nid
, memcg
->scan_nodes
)) {
1619 if (test_mem_cgroup_node_reclaimable(memcg
, nid
, noswap
))
1624 * Check rest of nodes.
1626 for_each_node_state(nid
, N_HIGH_MEMORY
) {
1627 if (node_isset(nid
, memcg
->scan_nodes
))
1629 if (test_mem_cgroup_node_reclaimable(memcg
, nid
, noswap
))
1636 int mem_cgroup_select_victim_node(struct mem_cgroup
*memcg
)
1641 bool mem_cgroup_reclaimable(struct mem_cgroup
*memcg
, bool noswap
)
1643 return test_mem_cgroup_node_reclaimable(memcg
, 0, noswap
);
1647 static int mem_cgroup_soft_reclaim(struct mem_cgroup
*root_memcg
,
1650 unsigned long *total_scanned
)
1652 struct mem_cgroup
*victim
= NULL
;
1655 unsigned long excess
;
1656 unsigned long nr_scanned
;
1657 struct mem_cgroup_reclaim_cookie reclaim
= {
1662 excess
= res_counter_soft_limit_excess(&root_memcg
->res
) >> PAGE_SHIFT
;
1665 victim
= mem_cgroup_iter(root_memcg
, victim
, &reclaim
);
1670 * If we have not been able to reclaim
1671 * anything, it might because there are
1672 * no reclaimable pages under this hierarchy
1677 * We want to do more targeted reclaim.
1678 * excess >> 2 is not to excessive so as to
1679 * reclaim too much, nor too less that we keep
1680 * coming back to reclaim from this cgroup
1682 if (total
>= (excess
>> 2) ||
1683 (loop
> MEM_CGROUP_MAX_RECLAIM_LOOPS
))
1688 if (!mem_cgroup_reclaimable(victim
, false))
1690 total
+= mem_cgroup_shrink_node_zone(victim
, gfp_mask
, false,
1692 *total_scanned
+= nr_scanned
;
1693 if (!res_counter_soft_limit_excess(&root_memcg
->res
))
1696 mem_cgroup_iter_break(root_memcg
, victim
);
1701 * Check OOM-Killer is already running under our hierarchy.
1702 * If someone is running, return false.
1703 * Has to be called with memcg_oom_lock
1705 static bool mem_cgroup_oom_lock(struct mem_cgroup
*memcg
)
1707 struct mem_cgroup
*iter
, *failed
= NULL
;
1709 for_each_mem_cgroup_tree(iter
, memcg
) {
1710 if (iter
->oom_lock
) {
1712 * this subtree of our hierarchy is already locked
1713 * so we cannot give a lock.
1716 mem_cgroup_iter_break(memcg
, iter
);
1719 iter
->oom_lock
= true;
1726 * OK, we failed to lock the whole subtree so we have to clean up
1727 * what we set up to the failing subtree
1729 for_each_mem_cgroup_tree(iter
, memcg
) {
1730 if (iter
== failed
) {
1731 mem_cgroup_iter_break(memcg
, iter
);
1734 iter
->oom_lock
= false;
1740 * Has to be called with memcg_oom_lock
1742 static int mem_cgroup_oom_unlock(struct mem_cgroup
*memcg
)
1744 struct mem_cgroup
*iter
;
1746 for_each_mem_cgroup_tree(iter
, memcg
)
1747 iter
->oom_lock
= false;
1751 static void mem_cgroup_mark_under_oom(struct mem_cgroup
*memcg
)
1753 struct mem_cgroup
*iter
;
1755 for_each_mem_cgroup_tree(iter
, memcg
)
1756 atomic_inc(&iter
->under_oom
);
1759 static void mem_cgroup_unmark_under_oom(struct mem_cgroup
*memcg
)
1761 struct mem_cgroup
*iter
;
1764 * When a new child is created while the hierarchy is under oom,
1765 * mem_cgroup_oom_lock() may not be called. We have to use
1766 * atomic_add_unless() here.
1768 for_each_mem_cgroup_tree(iter
, memcg
)
1769 atomic_add_unless(&iter
->under_oom
, -1, 0);
1772 static DEFINE_SPINLOCK(memcg_oom_lock
);
1773 static DECLARE_WAIT_QUEUE_HEAD(memcg_oom_waitq
);
1775 struct oom_wait_info
{
1776 struct mem_cgroup
*memcg
;
1780 static int memcg_oom_wake_function(wait_queue_t
*wait
,
1781 unsigned mode
, int sync
, void *arg
)
1783 struct mem_cgroup
*wake_memcg
= (struct mem_cgroup
*)arg
;
1784 struct mem_cgroup
*oom_wait_memcg
;
1785 struct oom_wait_info
*oom_wait_info
;
1787 oom_wait_info
= container_of(wait
, struct oom_wait_info
, wait
);
1788 oom_wait_memcg
= oom_wait_info
->memcg
;
1791 * Both of oom_wait_info->memcg and wake_memcg are stable under us.
1792 * Then we can use css_is_ancestor without taking care of RCU.
1794 if (!mem_cgroup_same_or_subtree(oom_wait_memcg
, wake_memcg
)
1795 && !mem_cgroup_same_or_subtree(wake_memcg
, oom_wait_memcg
))
1797 return autoremove_wake_function(wait
, mode
, sync
, arg
);
1800 static void memcg_wakeup_oom(struct mem_cgroup
*memcg
)
1802 /* for filtering, pass "memcg" as argument. */
1803 __wake_up(&memcg_oom_waitq
, TASK_NORMAL
, 0, memcg
);
1806 static void memcg_oom_recover(struct mem_cgroup
*memcg
)
1808 if (memcg
&& atomic_read(&memcg
->under_oom
))
1809 memcg_wakeup_oom(memcg
);
1813 * try to call OOM killer. returns false if we should exit memory-reclaim loop.
1815 bool mem_cgroup_handle_oom(struct mem_cgroup
*memcg
, gfp_t mask
, int order
)
1817 struct oom_wait_info owait
;
1818 bool locked
, need_to_kill
;
1820 owait
.memcg
= memcg
;
1821 owait
.wait
.flags
= 0;
1822 owait
.wait
.func
= memcg_oom_wake_function
;
1823 owait
.wait
.private = current
;
1824 INIT_LIST_HEAD(&owait
.wait
.task_list
);
1825 need_to_kill
= true;
1826 mem_cgroup_mark_under_oom(memcg
);
1828 /* At first, try to OOM lock hierarchy under memcg.*/
1829 spin_lock(&memcg_oom_lock
);
1830 locked
= mem_cgroup_oom_lock(memcg
);
1832 * Even if signal_pending(), we can't quit charge() loop without
1833 * accounting. So, UNINTERRUPTIBLE is appropriate. But SIGKILL
1834 * under OOM is always welcomed, use TASK_KILLABLE here.
1836 prepare_to_wait(&memcg_oom_waitq
, &owait
.wait
, TASK_KILLABLE
);
1837 if (!locked
|| memcg
->oom_kill_disable
)
1838 need_to_kill
= false;
1840 mem_cgroup_oom_notify(memcg
);
1841 spin_unlock(&memcg_oom_lock
);
1844 finish_wait(&memcg_oom_waitq
, &owait
.wait
);
1845 mem_cgroup_out_of_memory(memcg
, mask
, order
);
1848 finish_wait(&memcg_oom_waitq
, &owait
.wait
);
1850 spin_lock(&memcg_oom_lock
);
1852 mem_cgroup_oom_unlock(memcg
);
1853 memcg_wakeup_oom(memcg
);
1854 spin_unlock(&memcg_oom_lock
);
1856 mem_cgroup_unmark_under_oom(memcg
);
1858 if (test_thread_flag(TIF_MEMDIE
) || fatal_signal_pending(current
))
1860 /* Give chance to dying process */
1861 schedule_timeout_uninterruptible(1);
1866 * Currently used to update mapped file statistics, but the routine can be
1867 * generalized to update other statistics as well.
1869 * Notes: Race condition
1871 * We usually use page_cgroup_lock() for accessing page_cgroup member but
1872 * it tends to be costly. But considering some conditions, we doesn't need
1873 * to do so _always_.
1875 * Considering "charge", lock_page_cgroup() is not required because all
1876 * file-stat operations happen after a page is attached to radix-tree. There
1877 * are no race with "charge".
1879 * Considering "uncharge", we know that memcg doesn't clear pc->mem_cgroup
1880 * at "uncharge" intentionally. So, we always see valid pc->mem_cgroup even
1881 * if there are race with "uncharge". Statistics itself is properly handled
1884 * Considering "move", this is an only case we see a race. To make the race
1885 * small, we check MEM_CGROUP_ON_MOVE percpu value and detect there are
1886 * possibility of race condition. If there is, we take a lock.
1889 void mem_cgroup_update_page_stat(struct page
*page
,
1890 enum mem_cgroup_page_stat_item idx
, int val
)
1892 struct mem_cgroup
*memcg
;
1893 struct page_cgroup
*pc
= lookup_page_cgroup(page
);
1894 bool need_unlock
= false;
1895 unsigned long uninitialized_var(flags
);
1897 if (mem_cgroup_disabled())
1901 memcg
= pc
->mem_cgroup
;
1902 if (unlikely(!memcg
|| !PageCgroupUsed(pc
)))
1904 /* pc->mem_cgroup is unstable ? */
1905 if (unlikely(mem_cgroup_stealed(memcg
))) {
1906 /* take a lock against to access pc->mem_cgroup */
1907 move_lock_page_cgroup(pc
, &flags
);
1909 memcg
= pc
->mem_cgroup
;
1910 if (!memcg
|| !PageCgroupUsed(pc
))
1915 case MEMCG_NR_FILE_MAPPED
:
1917 SetPageCgroupFileMapped(pc
);
1918 else if (!page_mapped(page
))
1919 ClearPageCgroupFileMapped(pc
);
1920 idx
= MEM_CGROUP_STAT_FILE_MAPPED
;
1926 this_cpu_add(memcg
->stat
->count
[idx
], val
);
1929 if (unlikely(need_unlock
))
1930 move_unlock_page_cgroup(pc
, &flags
);
1935 * size of first charge trial. "32" comes from vmscan.c's magic value.
1936 * TODO: maybe necessary to use big numbers in big irons.
1938 #define CHARGE_BATCH 32U
1939 struct memcg_stock_pcp
{
1940 struct mem_cgroup
*cached
; /* this never be root cgroup */
1941 unsigned int nr_pages
;
1942 struct work_struct work
;
1943 unsigned long flags
;
1944 #define FLUSHING_CACHED_CHARGE (0)
1946 static DEFINE_PER_CPU(struct memcg_stock_pcp
, memcg_stock
);
1947 static DEFINE_MUTEX(percpu_charge_mutex
);
1950 * Try to consume stocked charge on this cpu. If success, one page is consumed
1951 * from local stock and true is returned. If the stock is 0 or charges from a
1952 * cgroup which is not current target, returns false. This stock will be
1955 static bool consume_stock(struct mem_cgroup
*memcg
)
1957 struct memcg_stock_pcp
*stock
;
1960 stock
= &get_cpu_var(memcg_stock
);
1961 if (memcg
== stock
->cached
&& stock
->nr_pages
)
1963 else /* need to call res_counter_charge */
1965 put_cpu_var(memcg_stock
);
1970 * Returns stocks cached in percpu to res_counter and reset cached information.
1972 static void drain_stock(struct memcg_stock_pcp
*stock
)
1974 struct mem_cgroup
*old
= stock
->cached
;
1976 if (stock
->nr_pages
) {
1977 unsigned long bytes
= stock
->nr_pages
* PAGE_SIZE
;
1979 res_counter_uncharge(&old
->res
, bytes
);
1980 if (do_swap_account
)
1981 res_counter_uncharge(&old
->memsw
, bytes
);
1982 stock
->nr_pages
= 0;
1984 stock
->cached
= NULL
;
1988 * This must be called under preempt disabled or must be called by
1989 * a thread which is pinned to local cpu.
1991 static void drain_local_stock(struct work_struct
*dummy
)
1993 struct memcg_stock_pcp
*stock
= &__get_cpu_var(memcg_stock
);
1995 clear_bit(FLUSHING_CACHED_CHARGE
, &stock
->flags
);
1999 * Cache charges(val) which is from res_counter, to local per_cpu area.
2000 * This will be consumed by consume_stock() function, later.
2002 static void refill_stock(struct mem_cgroup
*memcg
, unsigned int nr_pages
)
2004 struct memcg_stock_pcp
*stock
= &get_cpu_var(memcg_stock
);
2006 if (stock
->cached
!= memcg
) { /* reset if necessary */
2008 stock
->cached
= memcg
;
2010 stock
->nr_pages
+= nr_pages
;
2011 put_cpu_var(memcg_stock
);
2015 * Drains all per-CPU charge caches for given root_memcg resp. subtree
2016 * of the hierarchy under it. sync flag says whether we should block
2017 * until the work is done.
2019 static void drain_all_stock(struct mem_cgroup
*root_memcg
, bool sync
)
2023 /* Notify other cpus that system-wide "drain" is running */
2026 for_each_online_cpu(cpu
) {
2027 struct memcg_stock_pcp
*stock
= &per_cpu(memcg_stock
, cpu
);
2028 struct mem_cgroup
*memcg
;
2030 memcg
= stock
->cached
;
2031 if (!memcg
|| !stock
->nr_pages
)
2033 if (!mem_cgroup_same_or_subtree(root_memcg
, memcg
))
2035 if (!test_and_set_bit(FLUSHING_CACHED_CHARGE
, &stock
->flags
)) {
2037 drain_local_stock(&stock
->work
);
2039 schedule_work_on(cpu
, &stock
->work
);
2047 for_each_online_cpu(cpu
) {
2048 struct memcg_stock_pcp
*stock
= &per_cpu(memcg_stock
, cpu
);
2049 if (test_bit(FLUSHING_CACHED_CHARGE
, &stock
->flags
))
2050 flush_work(&stock
->work
);
2057 * Tries to drain stocked charges in other cpus. This function is asynchronous
2058 * and just put a work per cpu for draining localy on each cpu. Caller can
2059 * expects some charges will be back to res_counter later but cannot wait for
2062 static void drain_all_stock_async(struct mem_cgroup
*root_memcg
)
2065 * If someone calls draining, avoid adding more kworker runs.
2067 if (!mutex_trylock(&percpu_charge_mutex
))
2069 drain_all_stock(root_memcg
, false);
2070 mutex_unlock(&percpu_charge_mutex
);
2073 /* This is a synchronous drain interface. */
2074 static void drain_all_stock_sync(struct mem_cgroup
*root_memcg
)
2076 /* called when force_empty is called */
2077 mutex_lock(&percpu_charge_mutex
);
2078 drain_all_stock(root_memcg
, true);
2079 mutex_unlock(&percpu_charge_mutex
);
2083 * This function drains percpu counter value from DEAD cpu and
2084 * move it to local cpu. Note that this function can be preempted.
2086 static void mem_cgroup_drain_pcp_counter(struct mem_cgroup
*memcg
, int cpu
)
2090 spin_lock(&memcg
->pcp_counter_lock
);
2091 for (i
= 0; i
< MEM_CGROUP_STAT_DATA
; i
++) {
2092 long x
= per_cpu(memcg
->stat
->count
[i
], cpu
);
2094 per_cpu(memcg
->stat
->count
[i
], cpu
) = 0;
2095 memcg
->nocpu_base
.count
[i
] += x
;
2097 for (i
= 0; i
< MEM_CGROUP_EVENTS_NSTATS
; i
++) {
2098 unsigned long x
= per_cpu(memcg
->stat
->events
[i
], cpu
);
2100 per_cpu(memcg
->stat
->events
[i
], cpu
) = 0;
2101 memcg
->nocpu_base
.events
[i
] += x
;
2103 /* need to clear ON_MOVE value, works as a kind of lock. */
2104 per_cpu(memcg
->stat
->count
[MEM_CGROUP_ON_MOVE
], cpu
) = 0;
2105 spin_unlock(&memcg
->pcp_counter_lock
);
2108 static void synchronize_mem_cgroup_on_move(struct mem_cgroup
*memcg
, int cpu
)
2110 int idx
= MEM_CGROUP_ON_MOVE
;
2112 spin_lock(&memcg
->pcp_counter_lock
);
2113 per_cpu(memcg
->stat
->count
[idx
], cpu
) = memcg
->nocpu_base
.count
[idx
];
2114 spin_unlock(&memcg
->pcp_counter_lock
);
2117 static int __cpuinit
memcg_cpu_hotplug_callback(struct notifier_block
*nb
,
2118 unsigned long action
,
2121 int cpu
= (unsigned long)hcpu
;
2122 struct memcg_stock_pcp
*stock
;
2123 struct mem_cgroup
*iter
;
2125 if ((action
== CPU_ONLINE
)) {
2126 for_each_mem_cgroup(iter
)
2127 synchronize_mem_cgroup_on_move(iter
, cpu
);
2131 if ((action
!= CPU_DEAD
) || action
!= CPU_DEAD_FROZEN
)
2134 for_each_mem_cgroup(iter
)
2135 mem_cgroup_drain_pcp_counter(iter
, cpu
);
2137 stock
= &per_cpu(memcg_stock
, cpu
);
2143 /* See __mem_cgroup_try_charge() for details */
2145 CHARGE_OK
, /* success */
2146 CHARGE_RETRY
, /* need to retry but retry is not bad */
2147 CHARGE_NOMEM
, /* we can't do more. return -ENOMEM */
2148 CHARGE_WOULDBLOCK
, /* GFP_WAIT wasn't set and no enough res. */
2149 CHARGE_OOM_DIE
, /* the current is killed because of OOM */
2152 static int mem_cgroup_do_charge(struct mem_cgroup
*memcg
, gfp_t gfp_mask
,
2153 unsigned int nr_pages
, bool oom_check
)
2155 unsigned long csize
= nr_pages
* PAGE_SIZE
;
2156 struct mem_cgroup
*mem_over_limit
;
2157 struct res_counter
*fail_res
;
2158 unsigned long flags
= 0;
2161 ret
= res_counter_charge(&memcg
->res
, csize
, &fail_res
);
2164 if (!do_swap_account
)
2166 ret
= res_counter_charge(&memcg
->memsw
, csize
, &fail_res
);
2170 res_counter_uncharge(&memcg
->res
, csize
);
2171 mem_over_limit
= mem_cgroup_from_res_counter(fail_res
, memsw
);
2172 flags
|= MEM_CGROUP_RECLAIM_NOSWAP
;
2174 mem_over_limit
= mem_cgroup_from_res_counter(fail_res
, res
);
2176 * nr_pages can be either a huge page (HPAGE_PMD_NR), a batch
2177 * of regular pages (CHARGE_BATCH), or a single regular page (1).
2179 * Never reclaim on behalf of optional batching, retry with a
2180 * single page instead.
2182 if (nr_pages
== CHARGE_BATCH
)
2183 return CHARGE_RETRY
;
2185 if (!(gfp_mask
& __GFP_WAIT
))
2186 return CHARGE_WOULDBLOCK
;
2188 ret
= mem_cgroup_reclaim(mem_over_limit
, gfp_mask
, flags
);
2189 if (mem_cgroup_margin(mem_over_limit
) >= nr_pages
)
2190 return CHARGE_RETRY
;
2192 * Even though the limit is exceeded at this point, reclaim
2193 * may have been able to free some pages. Retry the charge
2194 * before killing the task.
2196 * Only for regular pages, though: huge pages are rather
2197 * unlikely to succeed so close to the limit, and we fall back
2198 * to regular pages anyway in case of failure.
2200 if (nr_pages
== 1 && ret
)
2201 return CHARGE_RETRY
;
2204 * At task move, charge accounts can be doubly counted. So, it's
2205 * better to wait until the end of task_move if something is going on.
2207 if (mem_cgroup_wait_acct_move(mem_over_limit
))
2208 return CHARGE_RETRY
;
2210 /* If we don't need to call oom-killer at el, return immediately */
2212 return CHARGE_NOMEM
;
2214 if (!mem_cgroup_handle_oom(mem_over_limit
, gfp_mask
, get_order(csize
)))
2215 return CHARGE_OOM_DIE
;
2217 return CHARGE_RETRY
;
2221 * __mem_cgroup_try_charge() does
2222 * 1. detect memcg to be charged against from passed *mm and *ptr,
2223 * 2. update res_counter
2224 * 3. call memory reclaim if necessary.
2226 * In some special case, if the task is fatal, fatal_signal_pending() or
2227 * has TIF_MEMDIE, this function returns -EINTR while writing root_mem_cgroup
2228 * to *ptr. There are two reasons for this. 1: fatal threads should quit as soon
2229 * as possible without any hazards. 2: all pages should have a valid
2230 * pc->mem_cgroup. If mm is NULL and the caller doesn't pass a valid memcg
2231 * pointer, that is treated as a charge to root_mem_cgroup.
2233 * So __mem_cgroup_try_charge() will return
2234 * 0 ... on success, filling *ptr with a valid memcg pointer.
2235 * -ENOMEM ... charge failure because of resource limits.
2236 * -EINTR ... if thread is fatal. *ptr is filled with root_mem_cgroup.
2238 * Unlike the exported interface, an "oom" parameter is added. if oom==true,
2239 * the oom-killer can be invoked.
2241 static int __mem_cgroup_try_charge(struct mm_struct
*mm
,
2243 unsigned int nr_pages
,
2244 struct mem_cgroup
**ptr
,
2247 unsigned int batch
= max(CHARGE_BATCH
, nr_pages
);
2248 int nr_oom_retries
= MEM_CGROUP_RECLAIM_RETRIES
;
2249 struct mem_cgroup
*memcg
= NULL
;
2253 * Unlike gloval-vm's OOM-kill, we're not in memory shortage
2254 * in system level. So, allow to go ahead dying process in addition to
2257 if (unlikely(test_thread_flag(TIF_MEMDIE
)
2258 || fatal_signal_pending(current
)))
2262 * We always charge the cgroup the mm_struct belongs to.
2263 * The mm_struct's mem_cgroup changes on task migration if the
2264 * thread group leader migrates. It's possible that mm is not
2265 * set, if so charge the init_mm (happens for pagecache usage).
2268 *ptr
= root_mem_cgroup
;
2270 if (*ptr
) { /* css should be a valid one */
2272 VM_BUG_ON(css_is_removed(&memcg
->css
));
2273 if (mem_cgroup_is_root(memcg
))
2275 if (nr_pages
== 1 && consume_stock(memcg
))
2277 css_get(&memcg
->css
);
2279 struct task_struct
*p
;
2282 p
= rcu_dereference(mm
->owner
);
2284 * Because we don't have task_lock(), "p" can exit.
2285 * In that case, "memcg" can point to root or p can be NULL with
2286 * race with swapoff. Then, we have small risk of mis-accouning.
2287 * But such kind of mis-account by race always happens because
2288 * we don't have cgroup_mutex(). It's overkill and we allo that
2290 * (*) swapoff at el will charge against mm-struct not against
2291 * task-struct. So, mm->owner can be NULL.
2293 memcg
= mem_cgroup_from_task(p
);
2295 memcg
= root_mem_cgroup
;
2296 if (mem_cgroup_is_root(memcg
)) {
2300 if (nr_pages
== 1 && consume_stock(memcg
)) {
2302 * It seems dagerous to access memcg without css_get().
2303 * But considering how consume_stok works, it's not
2304 * necessary. If consume_stock success, some charges
2305 * from this memcg are cached on this cpu. So, we
2306 * don't need to call css_get()/css_tryget() before
2307 * calling consume_stock().
2312 /* after here, we may be blocked. we need to get refcnt */
2313 if (!css_tryget(&memcg
->css
)) {
2323 /* If killed, bypass charge */
2324 if (fatal_signal_pending(current
)) {
2325 css_put(&memcg
->css
);
2330 if (oom
&& !nr_oom_retries
) {
2332 nr_oom_retries
= MEM_CGROUP_RECLAIM_RETRIES
;
2335 ret
= mem_cgroup_do_charge(memcg
, gfp_mask
, batch
, oom_check
);
2339 case CHARGE_RETRY
: /* not in OOM situation but retry */
2341 css_put(&memcg
->css
);
2344 case CHARGE_WOULDBLOCK
: /* !__GFP_WAIT */
2345 css_put(&memcg
->css
);
2347 case CHARGE_NOMEM
: /* OOM routine works */
2349 css_put(&memcg
->css
);
2352 /* If oom, we never return -ENOMEM */
2355 case CHARGE_OOM_DIE
: /* Killed by OOM Killer */
2356 css_put(&memcg
->css
);
2359 } while (ret
!= CHARGE_OK
);
2361 if (batch
> nr_pages
)
2362 refill_stock(memcg
, batch
- nr_pages
);
2363 css_put(&memcg
->css
);
2371 *ptr
= root_mem_cgroup
;
2376 * Somemtimes we have to undo a charge we got by try_charge().
2377 * This function is for that and do uncharge, put css's refcnt.
2378 * gotten by try_charge().
2380 static void __mem_cgroup_cancel_charge(struct mem_cgroup
*memcg
,
2381 unsigned int nr_pages
)
2383 if (!mem_cgroup_is_root(memcg
)) {
2384 unsigned long bytes
= nr_pages
* PAGE_SIZE
;
2386 res_counter_uncharge(&memcg
->res
, bytes
);
2387 if (do_swap_account
)
2388 res_counter_uncharge(&memcg
->memsw
, bytes
);
2393 * A helper function to get mem_cgroup from ID. must be called under
2394 * rcu_read_lock(). The caller must check css_is_removed() or some if
2395 * it's concern. (dropping refcnt from swap can be called against removed
2398 static struct mem_cgroup
*mem_cgroup_lookup(unsigned short id
)
2400 struct cgroup_subsys_state
*css
;
2402 /* ID 0 is unused ID */
2405 css
= css_lookup(&mem_cgroup_subsys
, id
);
2408 return container_of(css
, struct mem_cgroup
, css
);
2411 struct mem_cgroup
*try_get_mem_cgroup_from_page(struct page
*page
)
2413 struct mem_cgroup
*memcg
= NULL
;
2414 struct page_cgroup
*pc
;
2418 VM_BUG_ON(!PageLocked(page
));
2420 pc
= lookup_page_cgroup(page
);
2421 lock_page_cgroup(pc
);
2422 if (PageCgroupUsed(pc
)) {
2423 memcg
= pc
->mem_cgroup
;
2424 if (memcg
&& !css_tryget(&memcg
->css
))
2426 } else if (PageSwapCache(page
)) {
2427 ent
.val
= page_private(page
);
2428 id
= lookup_swap_cgroup_id(ent
);
2430 memcg
= mem_cgroup_lookup(id
);
2431 if (memcg
&& !css_tryget(&memcg
->css
))
2435 unlock_page_cgroup(pc
);
2439 static void __mem_cgroup_commit_charge(struct mem_cgroup
*memcg
,
2441 unsigned int nr_pages
,
2442 struct page_cgroup
*pc
,
2443 enum charge_type ctype
,
2446 struct zone
*uninitialized_var(zone
);
2447 bool was_on_lru
= false;
2450 lock_page_cgroup(pc
);
2451 if (unlikely(PageCgroupUsed(pc
))) {
2452 unlock_page_cgroup(pc
);
2453 __mem_cgroup_cancel_charge(memcg
, nr_pages
);
2457 * we don't need page_cgroup_lock about tail pages, becase they are not
2458 * accessed by any other context at this point.
2462 * In some cases, SwapCache and FUSE(splice_buf->radixtree), the page
2463 * may already be on some other mem_cgroup's LRU. Take care of it.
2466 zone
= page_zone(page
);
2467 spin_lock_irq(&zone
->lru_lock
);
2468 if (PageLRU(page
)) {
2470 del_page_from_lru_list(zone
, page
, page_lru(page
));
2475 pc
->mem_cgroup
= memcg
;
2477 * We access a page_cgroup asynchronously without lock_page_cgroup().
2478 * Especially when a page_cgroup is taken from a page, pc->mem_cgroup
2479 * is accessed after testing USED bit. To make pc->mem_cgroup visible
2480 * before USED bit, we need memory barrier here.
2481 * See mem_cgroup_add_lru_list(), etc.
2484 SetPageCgroupUsed(pc
);
2488 VM_BUG_ON(PageLRU(page
));
2490 add_page_to_lru_list(zone
, page
, page_lru(page
));
2492 spin_unlock_irq(&zone
->lru_lock
);
2495 if (ctype
== MEM_CGROUP_CHARGE_TYPE_MAPPED
)
2500 mem_cgroup_charge_statistics(memcg
, anon
, nr_pages
);
2501 unlock_page_cgroup(pc
);
2504 * "charge_statistics" updated event counter. Then, check it.
2505 * Insert ancestor (and ancestor's ancestors), to softlimit RB-tree.
2506 * if they exceeds softlimit.
2508 memcg_check_events(memcg
, page
);
2511 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
2513 #define PCGF_NOCOPY_AT_SPLIT ((1 << PCG_LOCK) | (1 << PCG_MOVE_LOCK) |\
2514 (1 << PCG_MIGRATION))
2516 * Because tail pages are not marked as "used", set it. We're under
2517 * zone->lru_lock, 'splitting on pmd' and compound_lock.
2518 * charge/uncharge will be never happen and move_account() is done under
2519 * compound_lock(), so we don't have to take care of races.
2521 void mem_cgroup_split_huge_fixup(struct page
*head
)
2523 struct page_cgroup
*head_pc
= lookup_page_cgroup(head
);
2524 struct page_cgroup
*pc
;
2527 if (mem_cgroup_disabled())
2529 for (i
= 1; i
< HPAGE_PMD_NR
; i
++) {
2531 pc
->mem_cgroup
= head_pc
->mem_cgroup
;
2532 smp_wmb();/* see __commit_charge() */
2533 pc
->flags
= head_pc
->flags
& ~PCGF_NOCOPY_AT_SPLIT
;
2536 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
2539 * mem_cgroup_move_account - move account of the page
2541 * @nr_pages: number of regular pages (>1 for huge pages)
2542 * @pc: page_cgroup of the page.
2543 * @from: mem_cgroup which the page is moved from.
2544 * @to: mem_cgroup which the page is moved to. @from != @to.
2545 * @uncharge: whether we should call uncharge and css_put against @from.
2547 * The caller must confirm following.
2548 * - page is not on LRU (isolate_page() is useful.)
2549 * - compound_lock is held when nr_pages > 1
2551 * This function doesn't do "charge" nor css_get to new cgroup. It should be
2552 * done by a caller(__mem_cgroup_try_charge would be useful). If @uncharge is
2553 * true, this function does "uncharge" from old cgroup, but it doesn't if
2554 * @uncharge is false, so a caller should do "uncharge".
2556 static int mem_cgroup_move_account(struct page
*page
,
2557 unsigned int nr_pages
,
2558 struct page_cgroup
*pc
,
2559 struct mem_cgroup
*from
,
2560 struct mem_cgroup
*to
,
2563 unsigned long flags
;
2565 bool anon
= PageAnon(page
);
2567 VM_BUG_ON(from
== to
);
2568 VM_BUG_ON(PageLRU(page
));
2570 * The page is isolated from LRU. So, collapse function
2571 * will not handle this page. But page splitting can happen.
2572 * Do this check under compound_page_lock(). The caller should
2576 if (nr_pages
> 1 && !PageTransHuge(page
))
2579 lock_page_cgroup(pc
);
2582 if (!PageCgroupUsed(pc
) || pc
->mem_cgroup
!= from
)
2585 move_lock_page_cgroup(pc
, &flags
);
2587 if (PageCgroupFileMapped(pc
)) {
2588 /* Update mapped_file data for mem_cgroup */
2590 __this_cpu_dec(from
->stat
->count
[MEM_CGROUP_STAT_FILE_MAPPED
]);
2591 __this_cpu_inc(to
->stat
->count
[MEM_CGROUP_STAT_FILE_MAPPED
]);
2594 mem_cgroup_charge_statistics(from
, anon
, -nr_pages
);
2596 /* This is not "cancel", but cancel_charge does all we need. */
2597 __mem_cgroup_cancel_charge(from
, nr_pages
);
2599 /* caller should have done css_get */
2600 pc
->mem_cgroup
= to
;
2601 mem_cgroup_charge_statistics(to
, anon
, nr_pages
);
2603 * We charges against "to" which may not have any tasks. Then, "to"
2604 * can be under rmdir(). But in current implementation, caller of
2605 * this function is just force_empty() and move charge, so it's
2606 * guaranteed that "to" is never removed. So, we don't check rmdir
2609 move_unlock_page_cgroup(pc
, &flags
);
2612 unlock_page_cgroup(pc
);
2616 memcg_check_events(to
, page
);
2617 memcg_check_events(from
, page
);
2623 * move charges to its parent.
2626 static int mem_cgroup_move_parent(struct page
*page
,
2627 struct page_cgroup
*pc
,
2628 struct mem_cgroup
*child
,
2631 struct cgroup
*cg
= child
->css
.cgroup
;
2632 struct cgroup
*pcg
= cg
->parent
;
2633 struct mem_cgroup
*parent
;
2634 unsigned int nr_pages
;
2635 unsigned long uninitialized_var(flags
);
2643 if (!get_page_unless_zero(page
))
2645 if (isolate_lru_page(page
))
2648 nr_pages
= hpage_nr_pages(page
);
2650 parent
= mem_cgroup_from_cont(pcg
);
2651 ret
= __mem_cgroup_try_charge(NULL
, gfp_mask
, nr_pages
, &parent
, false);
2656 flags
= compound_lock_irqsave(page
);
2658 ret
= mem_cgroup_move_account(page
, nr_pages
, pc
, child
, parent
, true);
2660 __mem_cgroup_cancel_charge(parent
, nr_pages
);
2663 compound_unlock_irqrestore(page
, flags
);
2665 putback_lru_page(page
);
2673 * Charge the memory controller for page usage.
2675 * 0 if the charge was successful
2676 * < 0 if the cgroup is over its limit
2678 static int mem_cgroup_charge_common(struct page
*page
, struct mm_struct
*mm
,
2679 gfp_t gfp_mask
, enum charge_type ctype
)
2681 struct mem_cgroup
*memcg
= NULL
;
2682 unsigned int nr_pages
= 1;
2683 struct page_cgroup
*pc
;
2687 if (PageTransHuge(page
)) {
2688 nr_pages
<<= compound_order(page
);
2689 VM_BUG_ON(!PageTransHuge(page
));
2691 * Never OOM-kill a process for a huge page. The
2692 * fault handler will fall back to regular pages.
2697 pc
= lookup_page_cgroup(page
);
2698 ret
= __mem_cgroup_try_charge(mm
, gfp_mask
, nr_pages
, &memcg
, oom
);
2701 __mem_cgroup_commit_charge(memcg
, page
, nr_pages
, pc
, ctype
, false);
2705 int mem_cgroup_newpage_charge(struct page
*page
,
2706 struct mm_struct
*mm
, gfp_t gfp_mask
)
2708 if (mem_cgroup_disabled())
2710 VM_BUG_ON(page_mapped(page
));
2711 VM_BUG_ON(page
->mapping
&& !PageAnon(page
));
2713 return mem_cgroup_charge_common(page
, mm
, gfp_mask
,
2714 MEM_CGROUP_CHARGE_TYPE_MAPPED
);
2718 __mem_cgroup_commit_charge_swapin(struct page
*page
, struct mem_cgroup
*ptr
,
2719 enum charge_type ctype
);
2721 int mem_cgroup_cache_charge(struct page
*page
, struct mm_struct
*mm
,
2724 struct mem_cgroup
*memcg
= NULL
;
2725 enum charge_type type
= MEM_CGROUP_CHARGE_TYPE_CACHE
;
2728 if (mem_cgroup_disabled())
2730 if (PageCompound(page
))
2735 if (!page_is_file_cache(page
))
2736 type
= MEM_CGROUP_CHARGE_TYPE_SHMEM
;
2738 if (!PageSwapCache(page
))
2739 ret
= mem_cgroup_charge_common(page
, mm
, gfp_mask
, type
);
2740 else { /* page is swapcache/shmem */
2741 ret
= mem_cgroup_try_charge_swapin(mm
, page
, gfp_mask
, &memcg
);
2743 __mem_cgroup_commit_charge_swapin(page
, memcg
, type
);
2749 * While swap-in, try_charge -> commit or cancel, the page is locked.
2750 * And when try_charge() successfully returns, one refcnt to memcg without
2751 * struct page_cgroup is acquired. This refcnt will be consumed by
2752 * "commit()" or removed by "cancel()"
2754 int mem_cgroup_try_charge_swapin(struct mm_struct
*mm
,
2756 gfp_t mask
, struct mem_cgroup
**memcgp
)
2758 struct mem_cgroup
*memcg
;
2763 if (mem_cgroup_disabled())
2766 if (!do_swap_account
)
2769 * A racing thread's fault, or swapoff, may have already updated
2770 * the pte, and even removed page from swap cache: in those cases
2771 * do_swap_page()'s pte_same() test will fail; but there's also a
2772 * KSM case which does need to charge the page.
2774 if (!PageSwapCache(page
))
2776 memcg
= try_get_mem_cgroup_from_page(page
);
2780 ret
= __mem_cgroup_try_charge(NULL
, mask
, 1, memcgp
, true);
2781 css_put(&memcg
->css
);
2788 ret
= __mem_cgroup_try_charge(mm
, mask
, 1, memcgp
, true);
2795 __mem_cgroup_commit_charge_swapin(struct page
*page
, struct mem_cgroup
*memcg
,
2796 enum charge_type ctype
)
2798 struct page_cgroup
*pc
;
2800 if (mem_cgroup_disabled())
2804 cgroup_exclude_rmdir(&memcg
->css
);
2806 pc
= lookup_page_cgroup(page
);
2807 __mem_cgroup_commit_charge(memcg
, page
, 1, pc
, ctype
, true);
2809 * Now swap is on-memory. This means this page may be
2810 * counted both as mem and swap....double count.
2811 * Fix it by uncharging from memsw. Basically, this SwapCache is stable
2812 * under lock_page(). But in do_swap_page()::memory.c, reuse_swap_page()
2813 * may call delete_from_swap_cache() before reach here.
2815 if (do_swap_account
&& PageSwapCache(page
)) {
2816 swp_entry_t ent
= {.val
= page_private(page
)};
2817 struct mem_cgroup
*swap_memcg
;
2820 id
= swap_cgroup_record(ent
, 0);
2822 swap_memcg
= mem_cgroup_lookup(id
);
2825 * This recorded memcg can be obsolete one. So, avoid
2826 * calling css_tryget
2828 if (!mem_cgroup_is_root(swap_memcg
))
2829 res_counter_uncharge(&swap_memcg
->memsw
,
2831 mem_cgroup_swap_statistics(swap_memcg
, false);
2832 mem_cgroup_put(swap_memcg
);
2837 * At swapin, we may charge account against cgroup which has no tasks.
2838 * So, rmdir()->pre_destroy() can be called while we do this charge.
2839 * In that case, we need to call pre_destroy() again. check it here.
2841 cgroup_release_and_wakeup_rmdir(&memcg
->css
);
2844 void mem_cgroup_commit_charge_swapin(struct page
*page
,
2845 struct mem_cgroup
*memcg
)
2847 __mem_cgroup_commit_charge_swapin(page
, memcg
,
2848 MEM_CGROUP_CHARGE_TYPE_MAPPED
);
2851 void mem_cgroup_cancel_charge_swapin(struct mem_cgroup
*memcg
)
2853 if (mem_cgroup_disabled())
2857 __mem_cgroup_cancel_charge(memcg
, 1);
2860 static void mem_cgroup_do_uncharge(struct mem_cgroup
*memcg
,
2861 unsigned int nr_pages
,
2862 const enum charge_type ctype
)
2864 struct memcg_batch_info
*batch
= NULL
;
2865 bool uncharge_memsw
= true;
2867 /* If swapout, usage of swap doesn't decrease */
2868 if (!do_swap_account
|| ctype
== MEM_CGROUP_CHARGE_TYPE_SWAPOUT
)
2869 uncharge_memsw
= false;
2871 batch
= ¤t
->memcg_batch
;
2873 * In usual, we do css_get() when we remember memcg pointer.
2874 * But in this case, we keep res->usage until end of a series of
2875 * uncharges. Then, it's ok to ignore memcg's refcnt.
2878 batch
->memcg
= memcg
;
2880 * do_batch > 0 when unmapping pages or inode invalidate/truncate.
2881 * In those cases, all pages freed continuously can be expected to be in
2882 * the same cgroup and we have chance to coalesce uncharges.
2883 * But we do uncharge one by one if this is killed by OOM(TIF_MEMDIE)
2884 * because we want to do uncharge as soon as possible.
2887 if (!batch
->do_batch
|| test_thread_flag(TIF_MEMDIE
))
2888 goto direct_uncharge
;
2891 goto direct_uncharge
;
2894 * In typical case, batch->memcg == mem. This means we can
2895 * merge a series of uncharges to an uncharge of res_counter.
2896 * If not, we uncharge res_counter ony by one.
2898 if (batch
->memcg
!= memcg
)
2899 goto direct_uncharge
;
2900 /* remember freed charge and uncharge it later */
2903 batch
->memsw_nr_pages
++;
2906 res_counter_uncharge(&memcg
->res
, nr_pages
* PAGE_SIZE
);
2908 res_counter_uncharge(&memcg
->memsw
, nr_pages
* PAGE_SIZE
);
2909 if (unlikely(batch
->memcg
!= memcg
))
2910 memcg_oom_recover(memcg
);
2914 * uncharge if !page_mapped(page)
2916 static struct mem_cgroup
*
2917 __mem_cgroup_uncharge_common(struct page
*page
, enum charge_type ctype
)
2919 struct mem_cgroup
*memcg
= NULL
;
2920 unsigned int nr_pages
= 1;
2921 struct page_cgroup
*pc
;
2924 if (mem_cgroup_disabled())
2927 if (PageSwapCache(page
))
2930 if (PageTransHuge(page
)) {
2931 nr_pages
<<= compound_order(page
);
2932 VM_BUG_ON(!PageTransHuge(page
));
2935 * Check if our page_cgroup is valid
2937 pc
= lookup_page_cgroup(page
);
2938 if (unlikely(!PageCgroupUsed(pc
)))
2941 lock_page_cgroup(pc
);
2943 memcg
= pc
->mem_cgroup
;
2945 if (!PageCgroupUsed(pc
))
2948 anon
= PageAnon(page
);
2951 case MEM_CGROUP_CHARGE_TYPE_MAPPED
:
2954 case MEM_CGROUP_CHARGE_TYPE_DROP
:
2955 /* See mem_cgroup_prepare_migration() */
2956 if (page_mapped(page
) || PageCgroupMigration(pc
))
2959 case MEM_CGROUP_CHARGE_TYPE_SWAPOUT
:
2960 if (!PageAnon(page
)) { /* Shared memory */
2961 if (page
->mapping
&& !page_is_file_cache(page
))
2963 } else if (page_mapped(page
)) /* Anon */
2970 mem_cgroup_charge_statistics(memcg
, anon
, -nr_pages
);
2972 ClearPageCgroupUsed(pc
);
2974 * pc->mem_cgroup is not cleared here. It will be accessed when it's
2975 * freed from LRU. This is safe because uncharged page is expected not
2976 * to be reused (freed soon). Exception is SwapCache, it's handled by
2977 * special functions.
2980 unlock_page_cgroup(pc
);
2982 * even after unlock, we have memcg->res.usage here and this memcg
2983 * will never be freed.
2985 memcg_check_events(memcg
, page
);
2986 if (do_swap_account
&& ctype
== MEM_CGROUP_CHARGE_TYPE_SWAPOUT
) {
2987 mem_cgroup_swap_statistics(memcg
, true);
2988 mem_cgroup_get(memcg
);
2990 if (!mem_cgroup_is_root(memcg
))
2991 mem_cgroup_do_uncharge(memcg
, nr_pages
, ctype
);
2996 unlock_page_cgroup(pc
);
3000 void mem_cgroup_uncharge_page(struct page
*page
)
3003 if (page_mapped(page
))
3005 VM_BUG_ON(page
->mapping
&& !PageAnon(page
));
3006 __mem_cgroup_uncharge_common(page
, MEM_CGROUP_CHARGE_TYPE_MAPPED
);
3009 void mem_cgroup_uncharge_cache_page(struct page
*page
)
3011 VM_BUG_ON(page_mapped(page
));
3012 VM_BUG_ON(page
->mapping
);
3013 __mem_cgroup_uncharge_common(page
, MEM_CGROUP_CHARGE_TYPE_CACHE
);
3017 * Batch_start/batch_end is called in unmap_page_range/invlidate/trucate.
3018 * In that cases, pages are freed continuously and we can expect pages
3019 * are in the same memcg. All these calls itself limits the number of
3020 * pages freed at once, then uncharge_start/end() is called properly.
3021 * This may be called prural(2) times in a context,
3024 void mem_cgroup_uncharge_start(void)
3026 current
->memcg_batch
.do_batch
++;
3027 /* We can do nest. */
3028 if (current
->memcg_batch
.do_batch
== 1) {
3029 current
->memcg_batch
.memcg
= NULL
;
3030 current
->memcg_batch
.nr_pages
= 0;
3031 current
->memcg_batch
.memsw_nr_pages
= 0;
3035 void mem_cgroup_uncharge_end(void)
3037 struct memcg_batch_info
*batch
= ¤t
->memcg_batch
;
3039 if (!batch
->do_batch
)
3043 if (batch
->do_batch
) /* If stacked, do nothing. */
3049 * This "batch->memcg" is valid without any css_get/put etc...
3050 * bacause we hide charges behind us.
3052 if (batch
->nr_pages
)
3053 res_counter_uncharge(&batch
->memcg
->res
,
3054 batch
->nr_pages
* PAGE_SIZE
);
3055 if (batch
->memsw_nr_pages
)
3056 res_counter_uncharge(&batch
->memcg
->memsw
,
3057 batch
->memsw_nr_pages
* PAGE_SIZE
);
3058 memcg_oom_recover(batch
->memcg
);
3059 /* forget this pointer (for sanity check) */
3060 batch
->memcg
= NULL
;
3065 * called after __delete_from_swap_cache() and drop "page" account.
3066 * memcg information is recorded to swap_cgroup of "ent"
3069 mem_cgroup_uncharge_swapcache(struct page
*page
, swp_entry_t ent
, bool swapout
)
3071 struct mem_cgroup
*memcg
;
3072 int ctype
= MEM_CGROUP_CHARGE_TYPE_SWAPOUT
;
3074 if (!swapout
) /* this was a swap cache but the swap is unused ! */
3075 ctype
= MEM_CGROUP_CHARGE_TYPE_DROP
;
3077 memcg
= __mem_cgroup_uncharge_common(page
, ctype
);
3080 * record memcg information, if swapout && memcg != NULL,
3081 * mem_cgroup_get() was called in uncharge().
3083 if (do_swap_account
&& swapout
&& memcg
)
3084 swap_cgroup_record(ent
, css_id(&memcg
->css
));
3088 #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP
3090 * called from swap_entry_free(). remove record in swap_cgroup and
3091 * uncharge "memsw" account.
3093 void mem_cgroup_uncharge_swap(swp_entry_t ent
)
3095 struct mem_cgroup
*memcg
;
3098 if (!do_swap_account
)
3101 id
= swap_cgroup_record(ent
, 0);
3103 memcg
= mem_cgroup_lookup(id
);
3106 * We uncharge this because swap is freed.
3107 * This memcg can be obsolete one. We avoid calling css_tryget
3109 if (!mem_cgroup_is_root(memcg
))
3110 res_counter_uncharge(&memcg
->memsw
, PAGE_SIZE
);
3111 mem_cgroup_swap_statistics(memcg
, false);
3112 mem_cgroup_put(memcg
);
3118 * mem_cgroup_move_swap_account - move swap charge and swap_cgroup's record.
3119 * @entry: swap entry to be moved
3120 * @from: mem_cgroup which the entry is moved from
3121 * @to: mem_cgroup which the entry is moved to
3122 * @need_fixup: whether we should fixup res_counters and refcounts.
3124 * It succeeds only when the swap_cgroup's record for this entry is the same
3125 * as the mem_cgroup's id of @from.
3127 * Returns 0 on success, -EINVAL on failure.
3129 * The caller must have charged to @to, IOW, called res_counter_charge() about
3130 * both res and memsw, and called css_get().
3132 static int mem_cgroup_move_swap_account(swp_entry_t entry
,
3133 struct mem_cgroup
*from
, struct mem_cgroup
*to
, bool need_fixup
)
3135 unsigned short old_id
, new_id
;
3137 old_id
= css_id(&from
->css
);
3138 new_id
= css_id(&to
->css
);
3140 if (swap_cgroup_cmpxchg(entry
, old_id
, new_id
) == old_id
) {
3141 mem_cgroup_swap_statistics(from
, false);
3142 mem_cgroup_swap_statistics(to
, true);
3144 * This function is only called from task migration context now.
3145 * It postpones res_counter and refcount handling till the end
3146 * of task migration(mem_cgroup_clear_mc()) for performance
3147 * improvement. But we cannot postpone mem_cgroup_get(to)
3148 * because if the process that has been moved to @to does
3149 * swap-in, the refcount of @to might be decreased to 0.
3153 if (!mem_cgroup_is_root(from
))
3154 res_counter_uncharge(&from
->memsw
, PAGE_SIZE
);
3155 mem_cgroup_put(from
);
3157 * we charged both to->res and to->memsw, so we should
3160 if (!mem_cgroup_is_root(to
))
3161 res_counter_uncharge(&to
->res
, PAGE_SIZE
);
3168 static inline int mem_cgroup_move_swap_account(swp_entry_t entry
,
3169 struct mem_cgroup
*from
, struct mem_cgroup
*to
, bool need_fixup
)
3176 * Before starting migration, account PAGE_SIZE to mem_cgroup that the old
3179 int mem_cgroup_prepare_migration(struct page
*page
,
3180 struct page
*newpage
, struct mem_cgroup
**memcgp
, gfp_t gfp_mask
)
3182 struct mem_cgroup
*memcg
= NULL
;
3183 struct page_cgroup
*pc
;
3184 enum charge_type ctype
;
3189 VM_BUG_ON(PageTransHuge(page
));
3190 if (mem_cgroup_disabled())
3193 pc
= lookup_page_cgroup(page
);
3194 lock_page_cgroup(pc
);
3195 if (PageCgroupUsed(pc
)) {
3196 memcg
= pc
->mem_cgroup
;
3197 css_get(&memcg
->css
);
3199 * At migrating an anonymous page, its mapcount goes down
3200 * to 0 and uncharge() will be called. But, even if it's fully
3201 * unmapped, migration may fail and this page has to be
3202 * charged again. We set MIGRATION flag here and delay uncharge
3203 * until end_migration() is called
3205 * Corner Case Thinking
3207 * When the old page was mapped as Anon and it's unmap-and-freed
3208 * while migration was ongoing.
3209 * If unmap finds the old page, uncharge() of it will be delayed
3210 * until end_migration(). If unmap finds a new page, it's
3211 * uncharged when it make mapcount to be 1->0. If unmap code
3212 * finds swap_migration_entry, the new page will not be mapped
3213 * and end_migration() will find it(mapcount==0).
3216 * When the old page was mapped but migraion fails, the kernel
3217 * remaps it. A charge for it is kept by MIGRATION flag even
3218 * if mapcount goes down to 0. We can do remap successfully
3219 * without charging it again.
3222 * The "old" page is under lock_page() until the end of
3223 * migration, so, the old page itself will not be swapped-out.
3224 * If the new page is swapped out before end_migraton, our
3225 * hook to usual swap-out path will catch the event.
3228 SetPageCgroupMigration(pc
);
3230 unlock_page_cgroup(pc
);
3232 * If the page is not charged at this point,
3239 ret
= __mem_cgroup_try_charge(NULL
, gfp_mask
, 1, memcgp
, false);
3240 css_put(&memcg
->css
);/* drop extra refcnt */
3242 if (PageAnon(page
)) {
3243 lock_page_cgroup(pc
);
3244 ClearPageCgroupMigration(pc
);
3245 unlock_page_cgroup(pc
);
3247 * The old page may be fully unmapped while we kept it.
3249 mem_cgroup_uncharge_page(page
);
3251 /* we'll need to revisit this error code (we have -EINTR) */
3255 * We charge new page before it's used/mapped. So, even if unlock_page()
3256 * is called before end_migration, we can catch all events on this new
3257 * page. In the case new page is migrated but not remapped, new page's
3258 * mapcount will be finally 0 and we call uncharge in end_migration().
3260 pc
= lookup_page_cgroup(newpage
);
3262 ctype
= MEM_CGROUP_CHARGE_TYPE_MAPPED
;
3263 else if (page_is_file_cache(page
))
3264 ctype
= MEM_CGROUP_CHARGE_TYPE_CACHE
;
3266 ctype
= MEM_CGROUP_CHARGE_TYPE_SHMEM
;
3267 __mem_cgroup_commit_charge(memcg
, newpage
, 1, pc
, ctype
, false);
3271 /* remove redundant charge if migration failed*/
3272 void mem_cgroup_end_migration(struct mem_cgroup
*memcg
,
3273 struct page
*oldpage
, struct page
*newpage
, bool migration_ok
)
3275 struct page
*used
, *unused
;
3276 struct page_cgroup
*pc
;
3281 /* blocks rmdir() */
3282 cgroup_exclude_rmdir(&memcg
->css
);
3283 if (!migration_ok
) {
3291 * We disallowed uncharge of pages under migration because mapcount
3292 * of the page goes down to zero, temporarly.
3293 * Clear the flag and check the page should be charged.
3295 pc
= lookup_page_cgroup(oldpage
);
3296 lock_page_cgroup(pc
);
3297 ClearPageCgroupMigration(pc
);
3298 unlock_page_cgroup(pc
);
3299 anon
= PageAnon(used
);
3300 __mem_cgroup_uncharge_common(unused
,
3301 anon
? MEM_CGROUP_CHARGE_TYPE_MAPPED
3302 : MEM_CGROUP_CHARGE_TYPE_CACHE
);
3305 * If a page is a file cache, radix-tree replacement is very atomic
3306 * and we can skip this check. When it was an Anon page, its mapcount
3307 * goes down to 0. But because we added MIGRATION flage, it's not
3308 * uncharged yet. There are several case but page->mapcount check
3309 * and USED bit check in mem_cgroup_uncharge_page() will do enough
3310 * check. (see prepare_charge() also)
3313 mem_cgroup_uncharge_page(used
);
3315 * At migration, we may charge account against cgroup which has no
3317 * So, rmdir()->pre_destroy() can be called while we do this charge.
3318 * In that case, we need to call pre_destroy() again. check it here.
3320 cgroup_release_and_wakeup_rmdir(&memcg
->css
);
3324 * At replace page cache, newpage is not under any memcg but it's on
3325 * LRU. So, this function doesn't touch res_counter but handles LRU
3326 * in correct way. Both pages are locked so we cannot race with uncharge.
3328 void mem_cgroup_replace_page_cache(struct page
*oldpage
,
3329 struct page
*newpage
)
3331 struct mem_cgroup
*memcg
;
3332 struct page_cgroup
*pc
;
3333 enum charge_type type
= MEM_CGROUP_CHARGE_TYPE_CACHE
;
3335 if (mem_cgroup_disabled())
3338 pc
= lookup_page_cgroup(oldpage
);
3339 /* fix accounting on old pages */
3340 lock_page_cgroup(pc
);
3341 memcg
= pc
->mem_cgroup
;
3342 mem_cgroup_charge_statistics(memcg
, false, -1);
3343 ClearPageCgroupUsed(pc
);
3344 unlock_page_cgroup(pc
);
3346 if (PageSwapBacked(oldpage
))
3347 type
= MEM_CGROUP_CHARGE_TYPE_SHMEM
;
3350 * Even if newpage->mapping was NULL before starting replacement,
3351 * the newpage may be on LRU(or pagevec for LRU) already. We lock
3352 * LRU while we overwrite pc->mem_cgroup.
3354 __mem_cgroup_commit_charge(memcg
, newpage
, 1, pc
, type
, true);
3357 #ifdef CONFIG_DEBUG_VM
3358 static struct page_cgroup
*lookup_page_cgroup_used(struct page
*page
)
3360 struct page_cgroup
*pc
;
3362 pc
= lookup_page_cgroup(page
);
3364 * Can be NULL while feeding pages into the page allocator for
3365 * the first time, i.e. during boot or memory hotplug;
3366 * or when mem_cgroup_disabled().
3368 if (likely(pc
) && PageCgroupUsed(pc
))
3373 bool mem_cgroup_bad_page_check(struct page
*page
)
3375 if (mem_cgroup_disabled())
3378 return lookup_page_cgroup_used(page
) != NULL
;
3381 void mem_cgroup_print_bad_page(struct page
*page
)
3383 struct page_cgroup
*pc
;
3385 pc
= lookup_page_cgroup_used(page
);
3387 printk(KERN_ALERT
"pc:%p pc->flags:%lx pc->mem_cgroup:%p\n",
3388 pc
, pc
->flags
, pc
->mem_cgroup
);
3393 static DEFINE_MUTEX(set_limit_mutex
);
3395 static int mem_cgroup_resize_limit(struct mem_cgroup
*memcg
,
3396 unsigned long long val
)
3399 u64 memswlimit
, memlimit
;
3401 int children
= mem_cgroup_count_children(memcg
);
3402 u64 curusage
, oldusage
;
3406 * For keeping hierarchical_reclaim simple, how long we should retry
3407 * is depends on callers. We set our retry-count to be function
3408 * of # of children which we should visit in this loop.
3410 retry_count
= MEM_CGROUP_RECLAIM_RETRIES
* children
;
3412 oldusage
= res_counter_read_u64(&memcg
->res
, RES_USAGE
);
3415 while (retry_count
) {
3416 if (signal_pending(current
)) {
3421 * Rather than hide all in some function, I do this in
3422 * open coded manner. You see what this really does.
3423 * We have to guarantee memcg->res.limit < memcg->memsw.limit.
3425 mutex_lock(&set_limit_mutex
);
3426 memswlimit
= res_counter_read_u64(&memcg
->memsw
, RES_LIMIT
);
3427 if (memswlimit
< val
) {
3429 mutex_unlock(&set_limit_mutex
);
3433 memlimit
= res_counter_read_u64(&memcg
->res
, RES_LIMIT
);
3437 ret
= res_counter_set_limit(&memcg
->res
, val
);
3439 if (memswlimit
== val
)
3440 memcg
->memsw_is_minimum
= true;
3442 memcg
->memsw_is_minimum
= false;
3444 mutex_unlock(&set_limit_mutex
);
3449 mem_cgroup_reclaim(memcg
, GFP_KERNEL
,
3450 MEM_CGROUP_RECLAIM_SHRINK
);
3451 curusage
= res_counter_read_u64(&memcg
->res
, RES_USAGE
);
3452 /* Usage is reduced ? */
3453 if (curusage
>= oldusage
)
3456 oldusage
= curusage
;
3458 if (!ret
&& enlarge
)
3459 memcg_oom_recover(memcg
);
3464 static int mem_cgroup_resize_memsw_limit(struct mem_cgroup
*memcg
,
3465 unsigned long long val
)
3468 u64 memlimit
, memswlimit
, oldusage
, curusage
;
3469 int children
= mem_cgroup_count_children(memcg
);
3473 /* see mem_cgroup_resize_res_limit */
3474 retry_count
= children
* MEM_CGROUP_RECLAIM_RETRIES
;
3475 oldusage
= res_counter_read_u64(&memcg
->memsw
, RES_USAGE
);
3476 while (retry_count
) {
3477 if (signal_pending(current
)) {
3482 * Rather than hide all in some function, I do this in
3483 * open coded manner. You see what this really does.
3484 * We have to guarantee memcg->res.limit < memcg->memsw.limit.
3486 mutex_lock(&set_limit_mutex
);
3487 memlimit
= res_counter_read_u64(&memcg
->res
, RES_LIMIT
);
3488 if (memlimit
> val
) {
3490 mutex_unlock(&set_limit_mutex
);
3493 memswlimit
= res_counter_read_u64(&memcg
->memsw
, RES_LIMIT
);
3494 if (memswlimit
< val
)
3496 ret
= res_counter_set_limit(&memcg
->memsw
, val
);
3498 if (memlimit
== val
)
3499 memcg
->memsw_is_minimum
= true;
3501 memcg
->memsw_is_minimum
= false;
3503 mutex_unlock(&set_limit_mutex
);
3508 mem_cgroup_reclaim(memcg
, GFP_KERNEL
,
3509 MEM_CGROUP_RECLAIM_NOSWAP
|
3510 MEM_CGROUP_RECLAIM_SHRINK
);
3511 curusage
= res_counter_read_u64(&memcg
->memsw
, RES_USAGE
);
3512 /* Usage is reduced ? */
3513 if (curusage
>= oldusage
)
3516 oldusage
= curusage
;
3518 if (!ret
&& enlarge
)
3519 memcg_oom_recover(memcg
);
3523 unsigned long mem_cgroup_soft_limit_reclaim(struct zone
*zone
, int order
,
3525 unsigned long *total_scanned
)
3527 unsigned long nr_reclaimed
= 0;
3528 struct mem_cgroup_per_zone
*mz
, *next_mz
= NULL
;
3529 unsigned long reclaimed
;
3531 struct mem_cgroup_tree_per_zone
*mctz
;
3532 unsigned long long excess
;
3533 unsigned long nr_scanned
;
3538 mctz
= soft_limit_tree_node_zone(zone_to_nid(zone
), zone_idx(zone
));
3540 * This loop can run a while, specially if mem_cgroup's continuously
3541 * keep exceeding their soft limit and putting the system under
3548 mz
= mem_cgroup_largest_soft_limit_node(mctz
);
3553 reclaimed
= mem_cgroup_soft_reclaim(mz
->memcg
, zone
,
3554 gfp_mask
, &nr_scanned
);
3555 nr_reclaimed
+= reclaimed
;
3556 *total_scanned
+= nr_scanned
;
3557 spin_lock(&mctz
->lock
);
3560 * If we failed to reclaim anything from this memory cgroup
3561 * it is time to move on to the next cgroup
3567 * Loop until we find yet another one.
3569 * By the time we get the soft_limit lock
3570 * again, someone might have aded the
3571 * group back on the RB tree. Iterate to
3572 * make sure we get a different mem.
3573 * mem_cgroup_largest_soft_limit_node returns
3574 * NULL if no other cgroup is present on
3578 __mem_cgroup_largest_soft_limit_node(mctz
);
3580 css_put(&next_mz
->memcg
->css
);
3581 else /* next_mz == NULL or other memcg */
3585 __mem_cgroup_remove_exceeded(mz
->memcg
, mz
, mctz
);
3586 excess
= res_counter_soft_limit_excess(&mz
->memcg
->res
);
3588 * One school of thought says that we should not add
3589 * back the node to the tree if reclaim returns 0.
3590 * But our reclaim could return 0, simply because due
3591 * to priority we are exposing a smaller subset of
3592 * memory to reclaim from. Consider this as a longer
3595 /* If excess == 0, no tree ops */
3596 __mem_cgroup_insert_exceeded(mz
->memcg
, mz
, mctz
, excess
);
3597 spin_unlock(&mctz
->lock
);
3598 css_put(&mz
->memcg
->css
);
3601 * Could not reclaim anything and there are no more
3602 * mem cgroups to try or we seem to be looping without
3603 * reclaiming anything.
3605 if (!nr_reclaimed
&&
3607 loop
> MEM_CGROUP_MAX_SOFT_LIMIT_RECLAIM_LOOPS
))
3609 } while (!nr_reclaimed
);
3611 css_put(&next_mz
->memcg
->css
);
3612 return nr_reclaimed
;
3616 * This routine traverse page_cgroup in given list and drop them all.
3617 * *And* this routine doesn't reclaim page itself, just removes page_cgroup.
3619 static int mem_cgroup_force_empty_list(struct mem_cgroup
*memcg
,
3620 int node
, int zid
, enum lru_list lru
)
3622 struct mem_cgroup_per_zone
*mz
;
3623 unsigned long flags
, loop
;
3624 struct list_head
*list
;
3629 zone
= &NODE_DATA(node
)->node_zones
[zid
];
3630 mz
= mem_cgroup_zoneinfo(memcg
, node
, zid
);
3631 list
= &mz
->lruvec
.lists
[lru
];
3633 loop
= mz
->lru_size
[lru
];
3634 /* give some margin against EBUSY etc...*/
3638 struct page_cgroup
*pc
;
3642 spin_lock_irqsave(&zone
->lru_lock
, flags
);
3643 if (list_empty(list
)) {
3644 spin_unlock_irqrestore(&zone
->lru_lock
, flags
);
3647 page
= list_entry(list
->prev
, struct page
, lru
);
3649 list_move(&page
->lru
, list
);
3651 spin_unlock_irqrestore(&zone
->lru_lock
, flags
);
3654 spin_unlock_irqrestore(&zone
->lru_lock
, flags
);
3656 pc
= lookup_page_cgroup(page
);
3658 ret
= mem_cgroup_move_parent(page
, pc
, memcg
, GFP_KERNEL
);
3659 if (ret
== -ENOMEM
|| ret
== -EINTR
)
3662 if (ret
== -EBUSY
|| ret
== -EINVAL
) {
3663 /* found lock contention or "pc" is obsolete. */
3670 if (!ret
&& !list_empty(list
))
3676 * make mem_cgroup's charge to be 0 if there is no task.
3677 * This enables deleting this mem_cgroup.
3679 static int mem_cgroup_force_empty(struct mem_cgroup
*memcg
, bool free_all
)
3682 int node
, zid
, shrink
;
3683 int nr_retries
= MEM_CGROUP_RECLAIM_RETRIES
;
3684 struct cgroup
*cgrp
= memcg
->css
.cgroup
;
3686 css_get(&memcg
->css
);
3689 /* should free all ? */
3695 if (cgroup_task_count(cgrp
) || !list_empty(&cgrp
->children
))
3698 if (signal_pending(current
))
3700 /* This is for making all *used* pages to be on LRU. */
3701 lru_add_drain_all();
3702 drain_all_stock_sync(memcg
);
3704 mem_cgroup_start_move(memcg
);
3705 for_each_node_state(node
, N_HIGH_MEMORY
) {
3706 for (zid
= 0; !ret
&& zid
< MAX_NR_ZONES
; zid
++) {
3709 ret
= mem_cgroup_force_empty_list(memcg
,
3718 mem_cgroup_end_move(memcg
);
3719 memcg_oom_recover(memcg
);
3720 /* it seems parent cgroup doesn't have enough mem */
3724 /* "ret" should also be checked to ensure all lists are empty. */
3725 } while (memcg
->res
.usage
> 0 || ret
);
3727 css_put(&memcg
->css
);
3731 /* returns EBUSY if there is a task or if we come here twice. */
3732 if (cgroup_task_count(cgrp
) || !list_empty(&cgrp
->children
) || shrink
) {
3736 /* we call try-to-free pages for make this cgroup empty */
3737 lru_add_drain_all();
3738 /* try to free all pages in this cgroup */
3740 while (nr_retries
&& memcg
->res
.usage
> 0) {
3743 if (signal_pending(current
)) {
3747 progress
= try_to_free_mem_cgroup_pages(memcg
, GFP_KERNEL
,
3751 /* maybe some writeback is necessary */
3752 congestion_wait(BLK_RW_ASYNC
, HZ
/10);
3757 /* try move_account...there may be some *locked* pages. */
3761 int mem_cgroup_force_empty_write(struct cgroup
*cont
, unsigned int event
)
3763 return mem_cgroup_force_empty(mem_cgroup_from_cont(cont
), true);
3767 static u64
mem_cgroup_hierarchy_read(struct cgroup
*cont
, struct cftype
*cft
)
3769 return mem_cgroup_from_cont(cont
)->use_hierarchy
;
3772 static int mem_cgroup_hierarchy_write(struct cgroup
*cont
, struct cftype
*cft
,
3776 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cont
);
3777 struct cgroup
*parent
= cont
->parent
;
3778 struct mem_cgroup
*parent_memcg
= NULL
;
3781 parent_memcg
= mem_cgroup_from_cont(parent
);
3785 * If parent's use_hierarchy is set, we can't make any modifications
3786 * in the child subtrees. If it is unset, then the change can
3787 * occur, provided the current cgroup has no children.
3789 * For the root cgroup, parent_mem is NULL, we allow value to be
3790 * set if there are no children.
3792 if ((!parent_memcg
|| !parent_memcg
->use_hierarchy
) &&
3793 (val
== 1 || val
== 0)) {
3794 if (list_empty(&cont
->children
))
3795 memcg
->use_hierarchy
= val
;
3806 static unsigned long mem_cgroup_recursive_stat(struct mem_cgroup
*memcg
,
3807 enum mem_cgroup_stat_index idx
)
3809 struct mem_cgroup
*iter
;
3812 /* Per-cpu values can be negative, use a signed accumulator */
3813 for_each_mem_cgroup_tree(iter
, memcg
)
3814 val
+= mem_cgroup_read_stat(iter
, idx
);
3816 if (val
< 0) /* race ? */
3821 static inline u64
mem_cgroup_usage(struct mem_cgroup
*memcg
, bool swap
)
3825 if (!mem_cgroup_is_root(memcg
)) {
3827 return res_counter_read_u64(&memcg
->res
, RES_USAGE
);
3829 return res_counter_read_u64(&memcg
->memsw
, RES_USAGE
);
3832 val
= mem_cgroup_recursive_stat(memcg
, MEM_CGROUP_STAT_CACHE
);
3833 val
+= mem_cgroup_recursive_stat(memcg
, MEM_CGROUP_STAT_RSS
);
3836 val
+= mem_cgroup_recursive_stat(memcg
, MEM_CGROUP_STAT_SWAPOUT
);
3838 return val
<< PAGE_SHIFT
;
3841 static u64
mem_cgroup_read(struct cgroup
*cont
, struct cftype
*cft
)
3843 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cont
);
3847 type
= MEMFILE_TYPE(cft
->private);
3848 name
= MEMFILE_ATTR(cft
->private);
3851 if (name
== RES_USAGE
)
3852 val
= mem_cgroup_usage(memcg
, false);
3854 val
= res_counter_read_u64(&memcg
->res
, name
);
3857 if (name
== RES_USAGE
)
3858 val
= mem_cgroup_usage(memcg
, true);
3860 val
= res_counter_read_u64(&memcg
->memsw
, name
);
3869 * The user of this function is...
3872 static int mem_cgroup_write(struct cgroup
*cont
, struct cftype
*cft
,
3875 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cont
);
3877 unsigned long long val
;
3880 type
= MEMFILE_TYPE(cft
->private);
3881 name
= MEMFILE_ATTR(cft
->private);
3884 if (mem_cgroup_is_root(memcg
)) { /* Can't set limit on root */
3888 /* This function does all necessary parse...reuse it */
3889 ret
= res_counter_memparse_write_strategy(buffer
, &val
);
3893 ret
= mem_cgroup_resize_limit(memcg
, val
);
3895 ret
= mem_cgroup_resize_memsw_limit(memcg
, val
);
3897 case RES_SOFT_LIMIT
:
3898 ret
= res_counter_memparse_write_strategy(buffer
, &val
);
3902 * For memsw, soft limits are hard to implement in terms
3903 * of semantics, for now, we support soft limits for
3904 * control without swap
3907 ret
= res_counter_set_soft_limit(&memcg
->res
, val
);
3912 ret
= -EINVAL
; /* should be BUG() ? */
3918 static void memcg_get_hierarchical_limit(struct mem_cgroup
*memcg
,
3919 unsigned long long *mem_limit
, unsigned long long *memsw_limit
)
3921 struct cgroup
*cgroup
;
3922 unsigned long long min_limit
, min_memsw_limit
, tmp
;
3924 min_limit
= res_counter_read_u64(&memcg
->res
, RES_LIMIT
);
3925 min_memsw_limit
= res_counter_read_u64(&memcg
->memsw
, RES_LIMIT
);
3926 cgroup
= memcg
->css
.cgroup
;
3927 if (!memcg
->use_hierarchy
)
3930 while (cgroup
->parent
) {
3931 cgroup
= cgroup
->parent
;
3932 memcg
= mem_cgroup_from_cont(cgroup
);
3933 if (!memcg
->use_hierarchy
)
3935 tmp
= res_counter_read_u64(&memcg
->res
, RES_LIMIT
);
3936 min_limit
= min(min_limit
, tmp
);
3937 tmp
= res_counter_read_u64(&memcg
->memsw
, RES_LIMIT
);
3938 min_memsw_limit
= min(min_memsw_limit
, tmp
);
3941 *mem_limit
= min_limit
;
3942 *memsw_limit
= min_memsw_limit
;
3945 static int mem_cgroup_reset(struct cgroup
*cont
, unsigned int event
)
3947 struct mem_cgroup
*memcg
;
3950 memcg
= mem_cgroup_from_cont(cont
);
3951 type
= MEMFILE_TYPE(event
);
3952 name
= MEMFILE_ATTR(event
);
3956 res_counter_reset_max(&memcg
->res
);
3958 res_counter_reset_max(&memcg
->memsw
);
3962 res_counter_reset_failcnt(&memcg
->res
);
3964 res_counter_reset_failcnt(&memcg
->memsw
);
3971 static u64
mem_cgroup_move_charge_read(struct cgroup
*cgrp
,
3974 return mem_cgroup_from_cont(cgrp
)->move_charge_at_immigrate
;
3978 static int mem_cgroup_move_charge_write(struct cgroup
*cgrp
,
3979 struct cftype
*cft
, u64 val
)
3981 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cgrp
);
3983 if (val
>= (1 << NR_MOVE_TYPE
))
3986 * We check this value several times in both in can_attach() and
3987 * attach(), so we need cgroup lock to prevent this value from being
3991 memcg
->move_charge_at_immigrate
= val
;
3997 static int mem_cgroup_move_charge_write(struct cgroup
*cgrp
,
3998 struct cftype
*cft
, u64 val
)
4005 /* For read statistics */
4023 struct mcs_total_stat
{
4024 s64 stat
[NR_MCS_STAT
];
4030 } memcg_stat_strings
[NR_MCS_STAT
] = {
4031 {"cache", "total_cache"},
4032 {"rss", "total_rss"},
4033 {"mapped_file", "total_mapped_file"},
4034 {"pgpgin", "total_pgpgin"},
4035 {"pgpgout", "total_pgpgout"},
4036 {"swap", "total_swap"},
4037 {"pgfault", "total_pgfault"},
4038 {"pgmajfault", "total_pgmajfault"},
4039 {"inactive_anon", "total_inactive_anon"},
4040 {"active_anon", "total_active_anon"},
4041 {"inactive_file", "total_inactive_file"},
4042 {"active_file", "total_active_file"},
4043 {"unevictable", "total_unevictable"}
4048 mem_cgroup_get_local_stat(struct mem_cgroup
*memcg
, struct mcs_total_stat
*s
)
4053 val
= mem_cgroup_read_stat(memcg
, MEM_CGROUP_STAT_CACHE
);
4054 s
->stat
[MCS_CACHE
] += val
* PAGE_SIZE
;
4055 val
= mem_cgroup_read_stat(memcg
, MEM_CGROUP_STAT_RSS
);
4056 s
->stat
[MCS_RSS
] += val
* PAGE_SIZE
;
4057 val
= mem_cgroup_read_stat(memcg
, MEM_CGROUP_STAT_FILE_MAPPED
);
4058 s
->stat
[MCS_FILE_MAPPED
] += val
* PAGE_SIZE
;
4059 val
= mem_cgroup_read_events(memcg
, MEM_CGROUP_EVENTS_PGPGIN
);
4060 s
->stat
[MCS_PGPGIN
] += val
;
4061 val
= mem_cgroup_read_events(memcg
, MEM_CGROUP_EVENTS_PGPGOUT
);
4062 s
->stat
[MCS_PGPGOUT
] += val
;
4063 if (do_swap_account
) {
4064 val
= mem_cgroup_read_stat(memcg
, MEM_CGROUP_STAT_SWAPOUT
);
4065 s
->stat
[MCS_SWAP
] += val
* PAGE_SIZE
;
4067 val
= mem_cgroup_read_events(memcg
, MEM_CGROUP_EVENTS_PGFAULT
);
4068 s
->stat
[MCS_PGFAULT
] += val
;
4069 val
= mem_cgroup_read_events(memcg
, MEM_CGROUP_EVENTS_PGMAJFAULT
);
4070 s
->stat
[MCS_PGMAJFAULT
] += val
;
4073 val
= mem_cgroup_nr_lru_pages(memcg
, BIT(LRU_INACTIVE_ANON
));
4074 s
->stat
[MCS_INACTIVE_ANON
] += val
* PAGE_SIZE
;
4075 val
= mem_cgroup_nr_lru_pages(memcg
, BIT(LRU_ACTIVE_ANON
));
4076 s
->stat
[MCS_ACTIVE_ANON
] += val
* PAGE_SIZE
;
4077 val
= mem_cgroup_nr_lru_pages(memcg
, BIT(LRU_INACTIVE_FILE
));
4078 s
->stat
[MCS_INACTIVE_FILE
] += val
* PAGE_SIZE
;
4079 val
= mem_cgroup_nr_lru_pages(memcg
, BIT(LRU_ACTIVE_FILE
));
4080 s
->stat
[MCS_ACTIVE_FILE
] += val
* PAGE_SIZE
;
4081 val
= mem_cgroup_nr_lru_pages(memcg
, BIT(LRU_UNEVICTABLE
));
4082 s
->stat
[MCS_UNEVICTABLE
] += val
* PAGE_SIZE
;
4086 mem_cgroup_get_total_stat(struct mem_cgroup
*memcg
, struct mcs_total_stat
*s
)
4088 struct mem_cgroup
*iter
;
4090 for_each_mem_cgroup_tree(iter
, memcg
)
4091 mem_cgroup_get_local_stat(iter
, s
);
4095 static int mem_control_numa_stat_show(struct seq_file
*m
, void *arg
)
4098 unsigned long total_nr
, file_nr
, anon_nr
, unevictable_nr
;
4099 unsigned long node_nr
;
4100 struct cgroup
*cont
= m
->private;
4101 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cont
);
4103 total_nr
= mem_cgroup_nr_lru_pages(memcg
, LRU_ALL
);
4104 seq_printf(m
, "total=%lu", total_nr
);
4105 for_each_node_state(nid
, N_HIGH_MEMORY
) {
4106 node_nr
= mem_cgroup_node_nr_lru_pages(memcg
, nid
, LRU_ALL
);
4107 seq_printf(m
, " N%d=%lu", nid
, node_nr
);
4111 file_nr
= mem_cgroup_nr_lru_pages(memcg
, LRU_ALL_FILE
);
4112 seq_printf(m
, "file=%lu", file_nr
);
4113 for_each_node_state(nid
, N_HIGH_MEMORY
) {
4114 node_nr
= mem_cgroup_node_nr_lru_pages(memcg
, nid
,
4116 seq_printf(m
, " N%d=%lu", nid
, node_nr
);
4120 anon_nr
= mem_cgroup_nr_lru_pages(memcg
, LRU_ALL_ANON
);
4121 seq_printf(m
, "anon=%lu", anon_nr
);
4122 for_each_node_state(nid
, N_HIGH_MEMORY
) {
4123 node_nr
= mem_cgroup_node_nr_lru_pages(memcg
, nid
,
4125 seq_printf(m
, " N%d=%lu", nid
, node_nr
);
4129 unevictable_nr
= mem_cgroup_nr_lru_pages(memcg
, BIT(LRU_UNEVICTABLE
));
4130 seq_printf(m
, "unevictable=%lu", unevictable_nr
);
4131 for_each_node_state(nid
, N_HIGH_MEMORY
) {
4132 node_nr
= mem_cgroup_node_nr_lru_pages(memcg
, nid
,
4133 BIT(LRU_UNEVICTABLE
));
4134 seq_printf(m
, " N%d=%lu", nid
, node_nr
);
4139 #endif /* CONFIG_NUMA */
4141 static int mem_control_stat_show(struct cgroup
*cont
, struct cftype
*cft
,
4142 struct cgroup_map_cb
*cb
)
4144 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cont
);
4145 struct mcs_total_stat mystat
;
4148 memset(&mystat
, 0, sizeof(mystat
));
4149 mem_cgroup_get_local_stat(memcg
, &mystat
);
4152 for (i
= 0; i
< NR_MCS_STAT
; i
++) {
4153 if (i
== MCS_SWAP
&& !do_swap_account
)
4155 cb
->fill(cb
, memcg_stat_strings
[i
].local_name
, mystat
.stat
[i
]);
4158 /* Hierarchical information */
4160 unsigned long long limit
, memsw_limit
;
4161 memcg_get_hierarchical_limit(memcg
, &limit
, &memsw_limit
);
4162 cb
->fill(cb
, "hierarchical_memory_limit", limit
);
4163 if (do_swap_account
)
4164 cb
->fill(cb
, "hierarchical_memsw_limit", memsw_limit
);
4167 memset(&mystat
, 0, sizeof(mystat
));
4168 mem_cgroup_get_total_stat(memcg
, &mystat
);
4169 for (i
= 0; i
< NR_MCS_STAT
; i
++) {
4170 if (i
== MCS_SWAP
&& !do_swap_account
)
4172 cb
->fill(cb
, memcg_stat_strings
[i
].total_name
, mystat
.stat
[i
]);
4175 #ifdef CONFIG_DEBUG_VM
4178 struct mem_cgroup_per_zone
*mz
;
4179 unsigned long recent_rotated
[2] = {0, 0};
4180 unsigned long recent_scanned
[2] = {0, 0};
4182 for_each_online_node(nid
)
4183 for (zid
= 0; zid
< MAX_NR_ZONES
; zid
++) {
4184 mz
= mem_cgroup_zoneinfo(memcg
, nid
, zid
);
4186 recent_rotated
[0] +=
4187 mz
->reclaim_stat
.recent_rotated
[0];
4188 recent_rotated
[1] +=
4189 mz
->reclaim_stat
.recent_rotated
[1];
4190 recent_scanned
[0] +=
4191 mz
->reclaim_stat
.recent_scanned
[0];
4192 recent_scanned
[1] +=
4193 mz
->reclaim_stat
.recent_scanned
[1];
4195 cb
->fill(cb
, "recent_rotated_anon", recent_rotated
[0]);
4196 cb
->fill(cb
, "recent_rotated_file", recent_rotated
[1]);
4197 cb
->fill(cb
, "recent_scanned_anon", recent_scanned
[0]);
4198 cb
->fill(cb
, "recent_scanned_file", recent_scanned
[1]);
4205 static u64
mem_cgroup_swappiness_read(struct cgroup
*cgrp
, struct cftype
*cft
)
4207 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cgrp
);
4209 return mem_cgroup_swappiness(memcg
);
4212 static int mem_cgroup_swappiness_write(struct cgroup
*cgrp
, struct cftype
*cft
,
4215 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cgrp
);
4216 struct mem_cgroup
*parent
;
4221 if (cgrp
->parent
== NULL
)
4224 parent
= mem_cgroup_from_cont(cgrp
->parent
);
4228 /* If under hierarchy, only empty-root can set this value */
4229 if ((parent
->use_hierarchy
) ||
4230 (memcg
->use_hierarchy
&& !list_empty(&cgrp
->children
))) {
4235 memcg
->swappiness
= val
;
4242 static void __mem_cgroup_threshold(struct mem_cgroup
*memcg
, bool swap
)
4244 struct mem_cgroup_threshold_ary
*t
;
4250 t
= rcu_dereference(memcg
->thresholds
.primary
);
4252 t
= rcu_dereference(memcg
->memsw_thresholds
.primary
);
4257 usage
= mem_cgroup_usage(memcg
, swap
);
4260 * current_threshold points to threshold just below usage.
4261 * If it's not true, a threshold was crossed after last
4262 * call of __mem_cgroup_threshold().
4264 i
= t
->current_threshold
;
4267 * Iterate backward over array of thresholds starting from
4268 * current_threshold and check if a threshold is crossed.
4269 * If none of thresholds below usage is crossed, we read
4270 * only one element of the array here.
4272 for (; i
>= 0 && unlikely(t
->entries
[i
].threshold
> usage
); i
--)
4273 eventfd_signal(t
->entries
[i
].eventfd
, 1);
4275 /* i = current_threshold + 1 */
4279 * Iterate forward over array of thresholds starting from
4280 * current_threshold+1 and check if a threshold is crossed.
4281 * If none of thresholds above usage is crossed, we read
4282 * only one element of the array here.
4284 for (; i
< t
->size
&& unlikely(t
->entries
[i
].threshold
<= usage
); i
++)
4285 eventfd_signal(t
->entries
[i
].eventfd
, 1);
4287 /* Update current_threshold */
4288 t
->current_threshold
= i
- 1;
4293 static void mem_cgroup_threshold(struct mem_cgroup
*memcg
)
4296 __mem_cgroup_threshold(memcg
, false);
4297 if (do_swap_account
)
4298 __mem_cgroup_threshold(memcg
, true);
4300 memcg
= parent_mem_cgroup(memcg
);
4304 static int compare_thresholds(const void *a
, const void *b
)
4306 const struct mem_cgroup_threshold
*_a
= a
;
4307 const struct mem_cgroup_threshold
*_b
= b
;
4309 return _a
->threshold
- _b
->threshold
;
4312 static int mem_cgroup_oom_notify_cb(struct mem_cgroup
*memcg
)
4314 struct mem_cgroup_eventfd_list
*ev
;
4316 list_for_each_entry(ev
, &memcg
->oom_notify
, list
)
4317 eventfd_signal(ev
->eventfd
, 1);
4321 static void mem_cgroup_oom_notify(struct mem_cgroup
*memcg
)
4323 struct mem_cgroup
*iter
;
4325 for_each_mem_cgroup_tree(iter
, memcg
)
4326 mem_cgroup_oom_notify_cb(iter
);
4329 static int mem_cgroup_usage_register_event(struct cgroup
*cgrp
,
4330 struct cftype
*cft
, struct eventfd_ctx
*eventfd
, const char *args
)
4332 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cgrp
);
4333 struct mem_cgroup_thresholds
*thresholds
;
4334 struct mem_cgroup_threshold_ary
*new;
4335 int type
= MEMFILE_TYPE(cft
->private);
4336 u64 threshold
, usage
;
4339 ret
= res_counter_memparse_write_strategy(args
, &threshold
);
4343 mutex_lock(&memcg
->thresholds_lock
);
4346 thresholds
= &memcg
->thresholds
;
4347 else if (type
== _MEMSWAP
)
4348 thresholds
= &memcg
->memsw_thresholds
;
4352 usage
= mem_cgroup_usage(memcg
, type
== _MEMSWAP
);
4354 /* Check if a threshold crossed before adding a new one */
4355 if (thresholds
->primary
)
4356 __mem_cgroup_threshold(memcg
, type
== _MEMSWAP
);
4358 size
= thresholds
->primary
? thresholds
->primary
->size
+ 1 : 1;
4360 /* Allocate memory for new array of thresholds */
4361 new = kmalloc(sizeof(*new) + size
* sizeof(struct mem_cgroup_threshold
),
4369 /* Copy thresholds (if any) to new array */
4370 if (thresholds
->primary
) {
4371 memcpy(new->entries
, thresholds
->primary
->entries
, (size
- 1) *
4372 sizeof(struct mem_cgroup_threshold
));
4375 /* Add new threshold */
4376 new->entries
[size
- 1].eventfd
= eventfd
;
4377 new->entries
[size
- 1].threshold
= threshold
;
4379 /* Sort thresholds. Registering of new threshold isn't time-critical */
4380 sort(new->entries
, size
, sizeof(struct mem_cgroup_threshold
),
4381 compare_thresholds
, NULL
);
4383 /* Find current threshold */
4384 new->current_threshold
= -1;
4385 for (i
= 0; i
< size
; i
++) {
4386 if (new->entries
[i
].threshold
< usage
) {
4388 * new->current_threshold will not be used until
4389 * rcu_assign_pointer(), so it's safe to increment
4392 ++new->current_threshold
;
4396 /* Free old spare buffer and save old primary buffer as spare */
4397 kfree(thresholds
->spare
);
4398 thresholds
->spare
= thresholds
->primary
;
4400 rcu_assign_pointer(thresholds
->primary
, new);
4402 /* To be sure that nobody uses thresholds */
4406 mutex_unlock(&memcg
->thresholds_lock
);
4411 static void mem_cgroup_usage_unregister_event(struct cgroup
*cgrp
,
4412 struct cftype
*cft
, struct eventfd_ctx
*eventfd
)
4414 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cgrp
);
4415 struct mem_cgroup_thresholds
*thresholds
;
4416 struct mem_cgroup_threshold_ary
*new;
4417 int type
= MEMFILE_TYPE(cft
->private);
4421 mutex_lock(&memcg
->thresholds_lock
);
4423 thresholds
= &memcg
->thresholds
;
4424 else if (type
== _MEMSWAP
)
4425 thresholds
= &memcg
->memsw_thresholds
;
4430 * Something went wrong if we trying to unregister a threshold
4431 * if we don't have thresholds
4433 BUG_ON(!thresholds
);
4435 if (!thresholds
->primary
)
4438 usage
= mem_cgroup_usage(memcg
, type
== _MEMSWAP
);
4440 /* Check if a threshold crossed before removing */
4441 __mem_cgroup_threshold(memcg
, type
== _MEMSWAP
);
4443 /* Calculate new number of threshold */
4445 for (i
= 0; i
< thresholds
->primary
->size
; i
++) {
4446 if (thresholds
->primary
->entries
[i
].eventfd
!= eventfd
)
4450 new = thresholds
->spare
;
4452 /* Set thresholds array to NULL if we don't have thresholds */
4461 /* Copy thresholds and find current threshold */
4462 new->current_threshold
= -1;
4463 for (i
= 0, j
= 0; i
< thresholds
->primary
->size
; i
++) {
4464 if (thresholds
->primary
->entries
[i
].eventfd
== eventfd
)
4467 new->entries
[j
] = thresholds
->primary
->entries
[i
];
4468 if (new->entries
[j
].threshold
< usage
) {
4470 * new->current_threshold will not be used
4471 * until rcu_assign_pointer(), so it's safe to increment
4474 ++new->current_threshold
;
4480 /* Swap primary and spare array */
4481 thresholds
->spare
= thresholds
->primary
;
4482 rcu_assign_pointer(thresholds
->primary
, new);
4484 /* To be sure that nobody uses thresholds */
4487 mutex_unlock(&memcg
->thresholds_lock
);
4490 static int mem_cgroup_oom_register_event(struct cgroup
*cgrp
,
4491 struct cftype
*cft
, struct eventfd_ctx
*eventfd
, const char *args
)
4493 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cgrp
);
4494 struct mem_cgroup_eventfd_list
*event
;
4495 int type
= MEMFILE_TYPE(cft
->private);
4497 BUG_ON(type
!= _OOM_TYPE
);
4498 event
= kmalloc(sizeof(*event
), GFP_KERNEL
);
4502 spin_lock(&memcg_oom_lock
);
4504 event
->eventfd
= eventfd
;
4505 list_add(&event
->list
, &memcg
->oom_notify
);
4507 /* already in OOM ? */
4508 if (atomic_read(&memcg
->under_oom
))
4509 eventfd_signal(eventfd
, 1);
4510 spin_unlock(&memcg_oom_lock
);
4515 static void mem_cgroup_oom_unregister_event(struct cgroup
*cgrp
,
4516 struct cftype
*cft
, struct eventfd_ctx
*eventfd
)
4518 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cgrp
);
4519 struct mem_cgroup_eventfd_list
*ev
, *tmp
;
4520 int type
= MEMFILE_TYPE(cft
->private);
4522 BUG_ON(type
!= _OOM_TYPE
);
4524 spin_lock(&memcg_oom_lock
);
4526 list_for_each_entry_safe(ev
, tmp
, &memcg
->oom_notify
, list
) {
4527 if (ev
->eventfd
== eventfd
) {
4528 list_del(&ev
->list
);
4533 spin_unlock(&memcg_oom_lock
);
4536 static int mem_cgroup_oom_control_read(struct cgroup
*cgrp
,
4537 struct cftype
*cft
, struct cgroup_map_cb
*cb
)
4539 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cgrp
);
4541 cb
->fill(cb
, "oom_kill_disable", memcg
->oom_kill_disable
);
4543 if (atomic_read(&memcg
->under_oom
))
4544 cb
->fill(cb
, "under_oom", 1);
4546 cb
->fill(cb
, "under_oom", 0);
4550 static int mem_cgroup_oom_control_write(struct cgroup
*cgrp
,
4551 struct cftype
*cft
, u64 val
)
4553 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cgrp
);
4554 struct mem_cgroup
*parent
;
4556 /* cannot set to root cgroup and only 0 and 1 are allowed */
4557 if (!cgrp
->parent
|| !((val
== 0) || (val
== 1)))
4560 parent
= mem_cgroup_from_cont(cgrp
->parent
);
4563 /* oom-kill-disable is a flag for subhierarchy. */
4564 if ((parent
->use_hierarchy
) ||
4565 (memcg
->use_hierarchy
&& !list_empty(&cgrp
->children
))) {
4569 memcg
->oom_kill_disable
= val
;
4571 memcg_oom_recover(memcg
);
4577 static const struct file_operations mem_control_numa_stat_file_operations
= {
4579 .llseek
= seq_lseek
,
4580 .release
= single_release
,
4583 static int mem_control_numa_stat_open(struct inode
*unused
, struct file
*file
)
4585 struct cgroup
*cont
= file
->f_dentry
->d_parent
->d_fsdata
;
4587 file
->f_op
= &mem_control_numa_stat_file_operations
;
4588 return single_open(file
, mem_control_numa_stat_show
, cont
);
4590 #endif /* CONFIG_NUMA */
4592 #ifdef CONFIG_CGROUP_MEM_RES_CTLR_KMEM
4593 static int register_kmem_files(struct cgroup
*cont
, struct cgroup_subsys
*ss
)
4596 * Part of this would be better living in a separate allocation
4597 * function, leaving us with just the cgroup tree population work.
4598 * We, however, depend on state such as network's proto_list that
4599 * is only initialized after cgroup creation. I found the less
4600 * cumbersome way to deal with it to defer it all to populate time
4602 return mem_cgroup_sockets_init(cont
, ss
);
4605 static void kmem_cgroup_destroy(struct cgroup
*cont
)
4607 mem_cgroup_sockets_destroy(cont
);
4610 static int register_kmem_files(struct cgroup
*cont
, struct cgroup_subsys
*ss
)
4615 static void kmem_cgroup_destroy(struct cgroup
*cont
)
4620 static struct cftype mem_cgroup_files
[] = {
4622 .name
= "usage_in_bytes",
4623 .private = MEMFILE_PRIVATE(_MEM
, RES_USAGE
),
4624 .read_u64
= mem_cgroup_read
,
4625 .register_event
= mem_cgroup_usage_register_event
,
4626 .unregister_event
= mem_cgroup_usage_unregister_event
,
4629 .name
= "max_usage_in_bytes",
4630 .private = MEMFILE_PRIVATE(_MEM
, RES_MAX_USAGE
),
4631 .trigger
= mem_cgroup_reset
,
4632 .read_u64
= mem_cgroup_read
,
4635 .name
= "limit_in_bytes",
4636 .private = MEMFILE_PRIVATE(_MEM
, RES_LIMIT
),
4637 .write_string
= mem_cgroup_write
,
4638 .read_u64
= mem_cgroup_read
,
4641 .name
= "soft_limit_in_bytes",
4642 .private = MEMFILE_PRIVATE(_MEM
, RES_SOFT_LIMIT
),
4643 .write_string
= mem_cgroup_write
,
4644 .read_u64
= mem_cgroup_read
,
4648 .private = MEMFILE_PRIVATE(_MEM
, RES_FAILCNT
),
4649 .trigger
= mem_cgroup_reset
,
4650 .read_u64
= mem_cgroup_read
,
4654 .read_map
= mem_control_stat_show
,
4657 .name
= "force_empty",
4658 .trigger
= mem_cgroup_force_empty_write
,
4661 .name
= "use_hierarchy",
4662 .write_u64
= mem_cgroup_hierarchy_write
,
4663 .read_u64
= mem_cgroup_hierarchy_read
,
4666 .name
= "swappiness",
4667 .read_u64
= mem_cgroup_swappiness_read
,
4668 .write_u64
= mem_cgroup_swappiness_write
,
4671 .name
= "move_charge_at_immigrate",
4672 .read_u64
= mem_cgroup_move_charge_read
,
4673 .write_u64
= mem_cgroup_move_charge_write
,
4676 .name
= "oom_control",
4677 .read_map
= mem_cgroup_oom_control_read
,
4678 .write_u64
= mem_cgroup_oom_control_write
,
4679 .register_event
= mem_cgroup_oom_register_event
,
4680 .unregister_event
= mem_cgroup_oom_unregister_event
,
4681 .private = MEMFILE_PRIVATE(_OOM_TYPE
, OOM_CONTROL
),
4685 .name
= "numa_stat",
4686 .open
= mem_control_numa_stat_open
,
4692 #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP
4693 static struct cftype memsw_cgroup_files
[] = {
4695 .name
= "memsw.usage_in_bytes",
4696 .private = MEMFILE_PRIVATE(_MEMSWAP
, RES_USAGE
),
4697 .read_u64
= mem_cgroup_read
,
4698 .register_event
= mem_cgroup_usage_register_event
,
4699 .unregister_event
= mem_cgroup_usage_unregister_event
,
4702 .name
= "memsw.max_usage_in_bytes",
4703 .private = MEMFILE_PRIVATE(_MEMSWAP
, RES_MAX_USAGE
),
4704 .trigger
= mem_cgroup_reset
,
4705 .read_u64
= mem_cgroup_read
,
4708 .name
= "memsw.limit_in_bytes",
4709 .private = MEMFILE_PRIVATE(_MEMSWAP
, RES_LIMIT
),
4710 .write_string
= mem_cgroup_write
,
4711 .read_u64
= mem_cgroup_read
,
4714 .name
= "memsw.failcnt",
4715 .private = MEMFILE_PRIVATE(_MEMSWAP
, RES_FAILCNT
),
4716 .trigger
= mem_cgroup_reset
,
4717 .read_u64
= mem_cgroup_read
,
4721 static int register_memsw_files(struct cgroup
*cont
, struct cgroup_subsys
*ss
)
4723 if (!do_swap_account
)
4725 return cgroup_add_files(cont
, ss
, memsw_cgroup_files
,
4726 ARRAY_SIZE(memsw_cgroup_files
));
4729 static int register_memsw_files(struct cgroup
*cont
, struct cgroup_subsys
*ss
)
4735 static int alloc_mem_cgroup_per_zone_info(struct mem_cgroup
*memcg
, int node
)
4737 struct mem_cgroup_per_node
*pn
;
4738 struct mem_cgroup_per_zone
*mz
;
4740 int zone
, tmp
= node
;
4742 * This routine is called against possible nodes.
4743 * But it's BUG to call kmalloc() against offline node.
4745 * TODO: this routine can waste much memory for nodes which will
4746 * never be onlined. It's better to use memory hotplug callback
4749 if (!node_state(node
, N_NORMAL_MEMORY
))
4751 pn
= kzalloc_node(sizeof(*pn
), GFP_KERNEL
, tmp
);
4755 for (zone
= 0; zone
< MAX_NR_ZONES
; zone
++) {
4756 mz
= &pn
->zoneinfo
[zone
];
4758 INIT_LIST_HEAD(&mz
->lruvec
.lists
[lru
]);
4759 mz
->usage_in_excess
= 0;
4760 mz
->on_tree
= false;
4763 memcg
->info
.nodeinfo
[node
] = pn
;
4767 static void free_mem_cgroup_per_zone_info(struct mem_cgroup
*memcg
, int node
)
4769 kfree(memcg
->info
.nodeinfo
[node
]);
4772 static struct mem_cgroup
*mem_cgroup_alloc(void)
4774 struct mem_cgroup
*memcg
;
4775 int size
= sizeof(struct mem_cgroup
);
4777 /* Can be very big if MAX_NUMNODES is very big */
4778 if (size
< PAGE_SIZE
)
4779 memcg
= kzalloc(size
, GFP_KERNEL
);
4781 memcg
= vzalloc(size
);
4786 memcg
->stat
= alloc_percpu(struct mem_cgroup_stat_cpu
);
4789 spin_lock_init(&memcg
->pcp_counter_lock
);
4793 if (size
< PAGE_SIZE
)
4801 * Helpers for freeing a vzalloc()ed mem_cgroup by RCU,
4802 * but in process context. The work_freeing structure is overlaid
4803 * on the rcu_freeing structure, which itself is overlaid on memsw.
4805 static void vfree_work(struct work_struct
*work
)
4807 struct mem_cgroup
*memcg
;
4809 memcg
= container_of(work
, struct mem_cgroup
, work_freeing
);
4812 static void vfree_rcu(struct rcu_head
*rcu_head
)
4814 struct mem_cgroup
*memcg
;
4816 memcg
= container_of(rcu_head
, struct mem_cgroup
, rcu_freeing
);
4817 INIT_WORK(&memcg
->work_freeing
, vfree_work
);
4818 schedule_work(&memcg
->work_freeing
);
4822 * At destroying mem_cgroup, references from swap_cgroup can remain.
4823 * (scanning all at force_empty is too costly...)
4825 * Instead of clearing all references at force_empty, we remember
4826 * the number of reference from swap_cgroup and free mem_cgroup when
4827 * it goes down to 0.
4829 * Removal of cgroup itself succeeds regardless of refs from swap.
4832 static void __mem_cgroup_free(struct mem_cgroup
*memcg
)
4836 mem_cgroup_remove_from_trees(memcg
);
4837 free_css_id(&mem_cgroup_subsys
, &memcg
->css
);
4840 free_mem_cgroup_per_zone_info(memcg
, node
);
4842 free_percpu(memcg
->stat
);
4843 if (sizeof(struct mem_cgroup
) < PAGE_SIZE
)
4844 kfree_rcu(memcg
, rcu_freeing
);
4846 call_rcu(&memcg
->rcu_freeing
, vfree_rcu
);
4849 static void mem_cgroup_get(struct mem_cgroup
*memcg
)
4851 atomic_inc(&memcg
->refcnt
);
4854 static void __mem_cgroup_put(struct mem_cgroup
*memcg
, int count
)
4856 if (atomic_sub_and_test(count
, &memcg
->refcnt
)) {
4857 struct mem_cgroup
*parent
= parent_mem_cgroup(memcg
);
4858 __mem_cgroup_free(memcg
);
4860 mem_cgroup_put(parent
);
4864 static void mem_cgroup_put(struct mem_cgroup
*memcg
)
4866 __mem_cgroup_put(memcg
, 1);
4870 * Returns the parent mem_cgroup in memcgroup hierarchy with hierarchy enabled.
4872 struct mem_cgroup
*parent_mem_cgroup(struct mem_cgroup
*memcg
)
4874 if (!memcg
->res
.parent
)
4876 return mem_cgroup_from_res_counter(memcg
->res
.parent
, res
);
4878 EXPORT_SYMBOL(parent_mem_cgroup
);
4880 #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP
4881 static void __init
enable_swap_cgroup(void)
4883 if (!mem_cgroup_disabled() && really_do_swap_account
)
4884 do_swap_account
= 1;
4887 static void __init
enable_swap_cgroup(void)
4892 static int mem_cgroup_soft_limit_tree_init(void)
4894 struct mem_cgroup_tree_per_node
*rtpn
;
4895 struct mem_cgroup_tree_per_zone
*rtpz
;
4896 int tmp
, node
, zone
;
4898 for_each_node(node
) {
4900 if (!node_state(node
, N_NORMAL_MEMORY
))
4902 rtpn
= kzalloc_node(sizeof(*rtpn
), GFP_KERNEL
, tmp
);
4906 soft_limit_tree
.rb_tree_per_node
[node
] = rtpn
;
4908 for (zone
= 0; zone
< MAX_NR_ZONES
; zone
++) {
4909 rtpz
= &rtpn
->rb_tree_per_zone
[zone
];
4910 rtpz
->rb_root
= RB_ROOT
;
4911 spin_lock_init(&rtpz
->lock
);
4917 for_each_node(node
) {
4918 if (!soft_limit_tree
.rb_tree_per_node
[node
])
4920 kfree(soft_limit_tree
.rb_tree_per_node
[node
]);
4921 soft_limit_tree
.rb_tree_per_node
[node
] = NULL
;
4927 static struct cgroup_subsys_state
* __ref
4928 mem_cgroup_create(struct cgroup
*cont
)
4930 struct mem_cgroup
*memcg
, *parent
;
4931 long error
= -ENOMEM
;
4934 memcg
= mem_cgroup_alloc();
4936 return ERR_PTR(error
);
4939 if (alloc_mem_cgroup_per_zone_info(memcg
, node
))
4943 if (cont
->parent
== NULL
) {
4945 enable_swap_cgroup();
4947 if (mem_cgroup_soft_limit_tree_init())
4949 root_mem_cgroup
= memcg
;
4950 for_each_possible_cpu(cpu
) {
4951 struct memcg_stock_pcp
*stock
=
4952 &per_cpu(memcg_stock
, cpu
);
4953 INIT_WORK(&stock
->work
, drain_local_stock
);
4955 hotcpu_notifier(memcg_cpu_hotplug_callback
, 0);
4957 parent
= mem_cgroup_from_cont(cont
->parent
);
4958 memcg
->use_hierarchy
= parent
->use_hierarchy
;
4959 memcg
->oom_kill_disable
= parent
->oom_kill_disable
;
4962 if (parent
&& parent
->use_hierarchy
) {
4963 res_counter_init(&memcg
->res
, &parent
->res
);
4964 res_counter_init(&memcg
->memsw
, &parent
->memsw
);
4966 * We increment refcnt of the parent to ensure that we can
4967 * safely access it on res_counter_charge/uncharge.
4968 * This refcnt will be decremented when freeing this
4969 * mem_cgroup(see mem_cgroup_put).
4971 mem_cgroup_get(parent
);
4973 res_counter_init(&memcg
->res
, NULL
);
4974 res_counter_init(&memcg
->memsw
, NULL
);
4976 memcg
->last_scanned_node
= MAX_NUMNODES
;
4977 INIT_LIST_HEAD(&memcg
->oom_notify
);
4980 memcg
->swappiness
= mem_cgroup_swappiness(parent
);
4981 atomic_set(&memcg
->refcnt
, 1);
4982 memcg
->move_charge_at_immigrate
= 0;
4983 mutex_init(&memcg
->thresholds_lock
);
4986 __mem_cgroup_free(memcg
);
4987 return ERR_PTR(error
);
4990 static int mem_cgroup_pre_destroy(struct cgroup
*cont
)
4992 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cont
);
4994 return mem_cgroup_force_empty(memcg
, false);
4997 static void mem_cgroup_destroy(struct cgroup
*cont
)
4999 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cont
);
5001 kmem_cgroup_destroy(cont
);
5003 mem_cgroup_put(memcg
);
5006 static int mem_cgroup_populate(struct cgroup_subsys
*ss
,
5007 struct cgroup
*cont
)
5011 ret
= cgroup_add_files(cont
, ss
, mem_cgroup_files
,
5012 ARRAY_SIZE(mem_cgroup_files
));
5015 ret
= register_memsw_files(cont
, ss
);
5018 ret
= register_kmem_files(cont
, ss
);
5024 /* Handlers for move charge at task migration. */
5025 #define PRECHARGE_COUNT_AT_ONCE 256
5026 static int mem_cgroup_do_precharge(unsigned long count
)
5029 int batch_count
= PRECHARGE_COUNT_AT_ONCE
;
5030 struct mem_cgroup
*memcg
= mc
.to
;
5032 if (mem_cgroup_is_root(memcg
)) {
5033 mc
.precharge
+= count
;
5034 /* we don't need css_get for root */
5037 /* try to charge at once */
5039 struct res_counter
*dummy
;
5041 * "memcg" cannot be under rmdir() because we've already checked
5042 * by cgroup_lock_live_cgroup() that it is not removed and we
5043 * are still under the same cgroup_mutex. So we can postpone
5046 if (res_counter_charge(&memcg
->res
, PAGE_SIZE
* count
, &dummy
))
5048 if (do_swap_account
&& res_counter_charge(&memcg
->memsw
,
5049 PAGE_SIZE
* count
, &dummy
)) {
5050 res_counter_uncharge(&memcg
->res
, PAGE_SIZE
* count
);
5053 mc
.precharge
+= count
;
5057 /* fall back to one by one charge */
5059 if (signal_pending(current
)) {
5063 if (!batch_count
--) {
5064 batch_count
= PRECHARGE_COUNT_AT_ONCE
;
5067 ret
= __mem_cgroup_try_charge(NULL
,
5068 GFP_KERNEL
, 1, &memcg
, false);
5070 /* mem_cgroup_clear_mc() will do uncharge later */
5078 * is_target_pte_for_mc - check a pte whether it is valid for move charge
5079 * @vma: the vma the pte to be checked belongs
5080 * @addr: the address corresponding to the pte to be checked
5081 * @ptent: the pte to be checked
5082 * @target: the pointer the target page or swap ent will be stored(can be NULL)
5085 * 0(MC_TARGET_NONE): if the pte is not a target for move charge.
5086 * 1(MC_TARGET_PAGE): if the page corresponding to this pte is a target for
5087 * move charge. if @target is not NULL, the page is stored in target->page
5088 * with extra refcnt got(Callers should handle it).
5089 * 2(MC_TARGET_SWAP): if the swap entry corresponding to this pte is a
5090 * target for charge migration. if @target is not NULL, the entry is stored
5093 * Called with pte lock held.
5100 enum mc_target_type
{
5101 MC_TARGET_NONE
, /* not used */
5106 static struct page
*mc_handle_present_pte(struct vm_area_struct
*vma
,
5107 unsigned long addr
, pte_t ptent
)
5109 struct page
*page
= vm_normal_page(vma
, addr
, ptent
);
5111 if (!page
|| !page_mapped(page
))
5113 if (PageAnon(page
)) {
5114 /* we don't move shared anon */
5115 if (!move_anon() || page_mapcount(page
) > 2)
5117 } else if (!move_file())
5118 /* we ignore mapcount for file pages */
5120 if (!get_page_unless_zero(page
))
5126 static struct page
*mc_handle_swap_pte(struct vm_area_struct
*vma
,
5127 unsigned long addr
, pte_t ptent
, swp_entry_t
*entry
)
5130 struct page
*page
= NULL
;
5131 swp_entry_t ent
= pte_to_swp_entry(ptent
);
5133 if (!move_anon() || non_swap_entry(ent
))
5135 usage_count
= mem_cgroup_count_swap_user(ent
, &page
);
5136 if (usage_count
> 1) { /* we don't move shared anon */
5141 if (do_swap_account
)
5142 entry
->val
= ent
.val
;
5147 static struct page
*mc_handle_file_pte(struct vm_area_struct
*vma
,
5148 unsigned long addr
, pte_t ptent
, swp_entry_t
*entry
)
5150 struct page
*page
= NULL
;
5151 struct inode
*inode
;
5152 struct address_space
*mapping
;
5155 if (!vma
->vm_file
) /* anonymous vma */
5160 inode
= vma
->vm_file
->f_path
.dentry
->d_inode
;
5161 mapping
= vma
->vm_file
->f_mapping
;
5162 if (pte_none(ptent
))
5163 pgoff
= linear_page_index(vma
, addr
);
5164 else /* pte_file(ptent) is true */
5165 pgoff
= pte_to_pgoff(ptent
);
5167 /* page is moved even if it's not RSS of this task(page-faulted). */
5168 page
= find_get_page(mapping
, pgoff
);
5171 /* shmem/tmpfs may report page out on swap: account for that too. */
5172 if (radix_tree_exceptional_entry(page
)) {
5173 swp_entry_t swap
= radix_to_swp_entry(page
);
5174 if (do_swap_account
)
5176 page
= find_get_page(&swapper_space
, swap
.val
);
5182 static int is_target_pte_for_mc(struct vm_area_struct
*vma
,
5183 unsigned long addr
, pte_t ptent
, union mc_target
*target
)
5185 struct page
*page
= NULL
;
5186 struct page_cgroup
*pc
;
5188 swp_entry_t ent
= { .val
= 0 };
5190 if (pte_present(ptent
))
5191 page
= mc_handle_present_pte(vma
, addr
, ptent
);
5192 else if (is_swap_pte(ptent
))
5193 page
= mc_handle_swap_pte(vma
, addr
, ptent
, &ent
);
5194 else if (pte_none(ptent
) || pte_file(ptent
))
5195 page
= mc_handle_file_pte(vma
, addr
, ptent
, &ent
);
5197 if (!page
&& !ent
.val
)
5200 pc
= lookup_page_cgroup(page
);
5202 * Do only loose check w/o page_cgroup lock.
5203 * mem_cgroup_move_account() checks the pc is valid or not under
5206 if (PageCgroupUsed(pc
) && pc
->mem_cgroup
== mc
.from
) {
5207 ret
= MC_TARGET_PAGE
;
5209 target
->page
= page
;
5211 if (!ret
|| !target
)
5214 /* There is a swap entry and a page doesn't exist or isn't charged */
5215 if (ent
.val
&& !ret
&&
5216 css_id(&mc
.from
->css
) == lookup_swap_cgroup_id(ent
)) {
5217 ret
= MC_TARGET_SWAP
;
5224 static int mem_cgroup_count_precharge_pte_range(pmd_t
*pmd
,
5225 unsigned long addr
, unsigned long end
,
5226 struct mm_walk
*walk
)
5228 struct vm_area_struct
*vma
= walk
->private;
5232 split_huge_page_pmd(walk
->mm
, pmd
);
5233 if (pmd_trans_unstable(pmd
))
5236 pte
= pte_offset_map_lock(vma
->vm_mm
, pmd
, addr
, &ptl
);
5237 for (; addr
!= end
; pte
++, addr
+= PAGE_SIZE
)
5238 if (is_target_pte_for_mc(vma
, addr
, *pte
, NULL
))
5239 mc
.precharge
++; /* increment precharge temporarily */
5240 pte_unmap_unlock(pte
- 1, ptl
);
5246 static unsigned long mem_cgroup_count_precharge(struct mm_struct
*mm
)
5248 unsigned long precharge
;
5249 struct vm_area_struct
*vma
;
5251 down_read(&mm
->mmap_sem
);
5252 for (vma
= mm
->mmap
; vma
; vma
= vma
->vm_next
) {
5253 struct mm_walk mem_cgroup_count_precharge_walk
= {
5254 .pmd_entry
= mem_cgroup_count_precharge_pte_range
,
5258 if (is_vm_hugetlb_page(vma
))
5260 walk_page_range(vma
->vm_start
, vma
->vm_end
,
5261 &mem_cgroup_count_precharge_walk
);
5263 up_read(&mm
->mmap_sem
);
5265 precharge
= mc
.precharge
;
5271 static int mem_cgroup_precharge_mc(struct mm_struct
*mm
)
5273 unsigned long precharge
= mem_cgroup_count_precharge(mm
);
5275 VM_BUG_ON(mc
.moving_task
);
5276 mc
.moving_task
= current
;
5277 return mem_cgroup_do_precharge(precharge
);
5280 /* cancels all extra charges on mc.from and mc.to, and wakes up all waiters. */
5281 static void __mem_cgroup_clear_mc(void)
5283 struct mem_cgroup
*from
= mc
.from
;
5284 struct mem_cgroup
*to
= mc
.to
;
5286 /* we must uncharge all the leftover precharges from mc.to */
5288 __mem_cgroup_cancel_charge(mc
.to
, mc
.precharge
);
5292 * we didn't uncharge from mc.from at mem_cgroup_move_account(), so
5293 * we must uncharge here.
5295 if (mc
.moved_charge
) {
5296 __mem_cgroup_cancel_charge(mc
.from
, mc
.moved_charge
);
5297 mc
.moved_charge
= 0;
5299 /* we must fixup refcnts and charges */
5300 if (mc
.moved_swap
) {
5301 /* uncharge swap account from the old cgroup */
5302 if (!mem_cgroup_is_root(mc
.from
))
5303 res_counter_uncharge(&mc
.from
->memsw
,
5304 PAGE_SIZE
* mc
.moved_swap
);
5305 __mem_cgroup_put(mc
.from
, mc
.moved_swap
);
5307 if (!mem_cgroup_is_root(mc
.to
)) {
5309 * we charged both to->res and to->memsw, so we should
5312 res_counter_uncharge(&mc
.to
->res
,
5313 PAGE_SIZE
* mc
.moved_swap
);
5315 /* we've already done mem_cgroup_get(mc.to) */
5318 memcg_oom_recover(from
);
5319 memcg_oom_recover(to
);
5320 wake_up_all(&mc
.waitq
);
5323 static void mem_cgroup_clear_mc(void)
5325 struct mem_cgroup
*from
= mc
.from
;
5328 * we must clear moving_task before waking up waiters at the end of
5331 mc
.moving_task
= NULL
;
5332 __mem_cgroup_clear_mc();
5333 spin_lock(&mc
.lock
);
5336 spin_unlock(&mc
.lock
);
5337 mem_cgroup_end_move(from
);
5340 static int mem_cgroup_can_attach(struct cgroup
*cgroup
,
5341 struct cgroup_taskset
*tset
)
5343 struct task_struct
*p
= cgroup_taskset_first(tset
);
5345 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cgroup
);
5347 if (memcg
->move_charge_at_immigrate
) {
5348 struct mm_struct
*mm
;
5349 struct mem_cgroup
*from
= mem_cgroup_from_task(p
);
5351 VM_BUG_ON(from
== memcg
);
5353 mm
= get_task_mm(p
);
5356 /* We move charges only when we move a owner of the mm */
5357 if (mm
->owner
== p
) {
5360 VM_BUG_ON(mc
.precharge
);
5361 VM_BUG_ON(mc
.moved_charge
);
5362 VM_BUG_ON(mc
.moved_swap
);
5363 mem_cgroup_start_move(from
);
5364 spin_lock(&mc
.lock
);
5367 spin_unlock(&mc
.lock
);
5368 /* We set mc.moving_task later */
5370 ret
= mem_cgroup_precharge_mc(mm
);
5372 mem_cgroup_clear_mc();
5379 static void mem_cgroup_cancel_attach(struct cgroup
*cgroup
,
5380 struct cgroup_taskset
*tset
)
5382 mem_cgroup_clear_mc();
5385 static int mem_cgroup_move_charge_pte_range(pmd_t
*pmd
,
5386 unsigned long addr
, unsigned long end
,
5387 struct mm_walk
*walk
)
5390 struct vm_area_struct
*vma
= walk
->private;
5394 split_huge_page_pmd(walk
->mm
, pmd
);
5395 if (pmd_trans_unstable(pmd
))
5398 pte
= pte_offset_map_lock(vma
->vm_mm
, pmd
, addr
, &ptl
);
5399 for (; addr
!= end
; addr
+= PAGE_SIZE
) {
5400 pte_t ptent
= *(pte
++);
5401 union mc_target target
;
5404 struct page_cgroup
*pc
;
5410 type
= is_target_pte_for_mc(vma
, addr
, ptent
, &target
);
5412 case MC_TARGET_PAGE
:
5414 if (isolate_lru_page(page
))
5416 pc
= lookup_page_cgroup(page
);
5417 if (!mem_cgroup_move_account(page
, 1, pc
,
5418 mc
.from
, mc
.to
, false)) {
5420 /* we uncharge from mc.from later. */
5423 putback_lru_page(page
);
5424 put
: /* is_target_pte_for_mc() gets the page */
5427 case MC_TARGET_SWAP
:
5429 if (!mem_cgroup_move_swap_account(ent
,
5430 mc
.from
, mc
.to
, false)) {
5432 /* we fixup refcnts and charges later. */
5440 pte_unmap_unlock(pte
- 1, ptl
);
5445 * We have consumed all precharges we got in can_attach().
5446 * We try charge one by one, but don't do any additional
5447 * charges to mc.to if we have failed in charge once in attach()
5450 ret
= mem_cgroup_do_precharge(1);
5458 static void mem_cgroup_move_charge(struct mm_struct
*mm
)
5460 struct vm_area_struct
*vma
;
5462 lru_add_drain_all();
5464 if (unlikely(!down_read_trylock(&mm
->mmap_sem
))) {
5466 * Someone who are holding the mmap_sem might be waiting in
5467 * waitq. So we cancel all extra charges, wake up all waiters,
5468 * and retry. Because we cancel precharges, we might not be able
5469 * to move enough charges, but moving charge is a best-effort
5470 * feature anyway, so it wouldn't be a big problem.
5472 __mem_cgroup_clear_mc();
5476 for (vma
= mm
->mmap
; vma
; vma
= vma
->vm_next
) {
5478 struct mm_walk mem_cgroup_move_charge_walk
= {
5479 .pmd_entry
= mem_cgroup_move_charge_pte_range
,
5483 if (is_vm_hugetlb_page(vma
))
5485 ret
= walk_page_range(vma
->vm_start
, vma
->vm_end
,
5486 &mem_cgroup_move_charge_walk
);
5489 * means we have consumed all precharges and failed in
5490 * doing additional charge. Just abandon here.
5494 up_read(&mm
->mmap_sem
);
5497 static void mem_cgroup_move_task(struct cgroup
*cont
,
5498 struct cgroup_taskset
*tset
)
5500 struct task_struct
*p
= cgroup_taskset_first(tset
);
5501 struct mm_struct
*mm
= get_task_mm(p
);
5505 mem_cgroup_move_charge(mm
);
5510 mem_cgroup_clear_mc();
5512 #else /* !CONFIG_MMU */
5513 static int mem_cgroup_can_attach(struct cgroup
*cgroup
,
5514 struct cgroup_taskset
*tset
)
5518 static void mem_cgroup_cancel_attach(struct cgroup
*cgroup
,
5519 struct cgroup_taskset
*tset
)
5522 static void mem_cgroup_move_task(struct cgroup
*cont
,
5523 struct cgroup_taskset
*tset
)
5528 struct cgroup_subsys mem_cgroup_subsys
= {
5530 .subsys_id
= mem_cgroup_subsys_id
,
5531 .create
= mem_cgroup_create
,
5532 .pre_destroy
= mem_cgroup_pre_destroy
,
5533 .destroy
= mem_cgroup_destroy
,
5534 .populate
= mem_cgroup_populate
,
5535 .can_attach
= mem_cgroup_can_attach
,
5536 .cancel_attach
= mem_cgroup_cancel_attach
,
5537 .attach
= mem_cgroup_move_task
,
5542 #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP
5543 static int __init
enable_swap_account(char *s
)
5545 /* consider enabled if no parameter or 1 is given */
5546 if (!strcmp(s
, "1"))
5547 really_do_swap_account
= 1;
5548 else if (!strcmp(s
, "0"))
5549 really_do_swap_account
= 0;
5552 __setup("swapaccount=", enable_swap_account
);