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/mutex.h>
37 #include <linux/rbtree.h>
38 #include <linux/shmem_fs.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 <asm/uaccess.h>
56 #include <trace/events/vmscan.h>
58 struct cgroup_subsys mem_cgroup_subsys __read_mostly
;
59 #define MEM_CGROUP_RECLAIM_RETRIES 5
60 struct mem_cgroup
*root_mem_cgroup __read_mostly
;
62 #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP
63 /* Turned on only when memory cgroup is enabled && really_do_swap_account = 1 */
64 int do_swap_account __read_mostly
;
66 /* for remember boot option*/
67 #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP_ENABLED
68 static int really_do_swap_account __initdata
= 1;
70 static int really_do_swap_account __initdata
= 0;
74 #define do_swap_account (0)
79 * Statistics for memory cgroup.
81 enum mem_cgroup_stat_index
{
83 * For MEM_CONTAINER_TYPE_ALL, usage = pagecache + rss.
85 MEM_CGROUP_STAT_CACHE
, /* # of pages charged as cache */
86 MEM_CGROUP_STAT_RSS
, /* # of pages charged as anon rss */
87 MEM_CGROUP_STAT_FILE_MAPPED
, /* # of pages charged as file rss */
88 MEM_CGROUP_STAT_SWAPOUT
, /* # of pages, swapped out */
89 MEM_CGROUP_STAT_DATA
, /* end of data requires synchronization */
90 MEM_CGROUP_ON_MOVE
, /* someone is moving account between groups */
91 MEM_CGROUP_STAT_NSTATS
,
94 enum mem_cgroup_events_index
{
95 MEM_CGROUP_EVENTS_PGPGIN
, /* # of pages paged in */
96 MEM_CGROUP_EVENTS_PGPGOUT
, /* # of pages paged out */
97 MEM_CGROUP_EVENTS_COUNT
, /* # of pages paged in/out */
98 MEM_CGROUP_EVENTS_PGFAULT
, /* # of page-faults */
99 MEM_CGROUP_EVENTS_PGMAJFAULT
, /* # of major page-faults */
100 MEM_CGROUP_EVENTS_NSTATS
,
103 * Per memcg event counter is incremented at every pagein/pageout. With THP,
104 * it will be incremated by the number of pages. This counter is used for
105 * for trigger some periodic events. This is straightforward and better
106 * than using jiffies etc. to handle periodic memcg event.
108 enum mem_cgroup_events_target
{
109 MEM_CGROUP_TARGET_THRESH
,
110 MEM_CGROUP_TARGET_SOFTLIMIT
,
111 MEM_CGROUP_TARGET_NUMAINFO
,
114 #define THRESHOLDS_EVENTS_TARGET (128)
115 #define SOFTLIMIT_EVENTS_TARGET (1024)
116 #define NUMAINFO_EVENTS_TARGET (1024)
118 struct mem_cgroup_stat_cpu
{
119 long count
[MEM_CGROUP_STAT_NSTATS
];
120 unsigned long events
[MEM_CGROUP_EVENTS_NSTATS
];
121 unsigned long targets
[MEM_CGROUP_NTARGETS
];
125 * per-zone information in memory controller.
127 struct mem_cgroup_per_zone
{
129 * spin_lock to protect the per cgroup LRU
131 struct list_head lists
[NR_LRU_LISTS
];
132 unsigned long count
[NR_LRU_LISTS
];
134 struct zone_reclaim_stat reclaim_stat
;
135 struct rb_node tree_node
; /* RB tree node */
136 unsigned long long usage_in_excess
;/* Set to the value by which */
137 /* the soft limit is exceeded*/
139 struct mem_cgroup
*mem
; /* Back pointer, we cannot */
140 /* use container_of */
142 /* Macro for accessing counter */
143 #define MEM_CGROUP_ZSTAT(mz, idx) ((mz)->count[(idx)])
145 struct mem_cgroup_per_node
{
146 struct mem_cgroup_per_zone zoneinfo
[MAX_NR_ZONES
];
149 struct mem_cgroup_lru_info
{
150 struct mem_cgroup_per_node
*nodeinfo
[MAX_NUMNODES
];
154 * Cgroups above their limits are maintained in a RB-Tree, independent of
155 * their hierarchy representation
158 struct mem_cgroup_tree_per_zone
{
159 struct rb_root rb_root
;
163 struct mem_cgroup_tree_per_node
{
164 struct mem_cgroup_tree_per_zone rb_tree_per_zone
[MAX_NR_ZONES
];
167 struct mem_cgroup_tree
{
168 struct mem_cgroup_tree_per_node
*rb_tree_per_node
[MAX_NUMNODES
];
171 static struct mem_cgroup_tree soft_limit_tree __read_mostly
;
173 struct mem_cgroup_threshold
{
174 struct eventfd_ctx
*eventfd
;
179 struct mem_cgroup_threshold_ary
{
180 /* An array index points to threshold just below usage. */
181 int current_threshold
;
182 /* Size of entries[] */
184 /* Array of thresholds */
185 struct mem_cgroup_threshold entries
[0];
188 struct mem_cgroup_thresholds
{
189 /* Primary thresholds array */
190 struct mem_cgroup_threshold_ary
*primary
;
192 * Spare threshold array.
193 * This is needed to make mem_cgroup_unregister_event() "never fail".
194 * It must be able to store at least primary->size - 1 entries.
196 struct mem_cgroup_threshold_ary
*spare
;
200 struct mem_cgroup_eventfd_list
{
201 struct list_head list
;
202 struct eventfd_ctx
*eventfd
;
205 static void mem_cgroup_threshold(struct mem_cgroup
*mem
);
206 static void mem_cgroup_oom_notify(struct mem_cgroup
*mem
);
209 * The memory controller data structure. The memory controller controls both
210 * page cache and RSS per cgroup. We would eventually like to provide
211 * statistics based on the statistics developed by Rik Van Riel for clock-pro,
212 * to help the administrator determine what knobs to tune.
214 * TODO: Add a water mark for the memory controller. Reclaim will begin when
215 * we hit the water mark. May be even add a low water mark, such that
216 * no reclaim occurs from a cgroup at it's low water mark, this is
217 * a feature that will be implemented much later in the future.
220 struct cgroup_subsys_state css
;
222 * the counter to account for memory usage
224 struct res_counter res
;
226 * the counter to account for mem+swap usage.
228 struct res_counter memsw
;
230 * Per cgroup active and inactive list, similar to the
231 * per zone LRU lists.
233 struct mem_cgroup_lru_info info
;
235 * While reclaiming in a hierarchy, we cache the last child we
238 int last_scanned_child
;
239 int last_scanned_node
;
241 nodemask_t scan_nodes
;
242 atomic_t numainfo_events
;
243 atomic_t numainfo_updating
;
246 * Should the accounting and control be hierarchical, per subtree?
256 /* OOM-Killer disable */
257 int oom_kill_disable
;
259 /* set when res.limit == memsw.limit */
260 bool memsw_is_minimum
;
262 /* protect arrays of thresholds */
263 struct mutex thresholds_lock
;
265 /* thresholds for memory usage. RCU-protected */
266 struct mem_cgroup_thresholds thresholds
;
268 /* thresholds for mem+swap usage. RCU-protected */
269 struct mem_cgroup_thresholds memsw_thresholds
;
271 /* For oom notifier event fd */
272 struct list_head oom_notify
;
275 * Should we move charges of a task when a task is moved into this
276 * mem_cgroup ? And what type of charges should we move ?
278 unsigned long move_charge_at_immigrate
;
282 struct mem_cgroup_stat_cpu
*stat
;
284 * used when a cpu is offlined or other synchronizations
285 * See mem_cgroup_read_stat().
287 struct mem_cgroup_stat_cpu nocpu_base
;
288 spinlock_t pcp_counter_lock
;
291 /* Stuffs for move charges at task migration. */
293 * Types of charges to be moved. "move_charge_at_immitgrate" is treated as a
294 * left-shifted bitmap of these types.
297 MOVE_CHARGE_TYPE_ANON
, /* private anonymous page and swap of it */
298 MOVE_CHARGE_TYPE_FILE
, /* file page(including tmpfs) and swap of it */
302 /* "mc" and its members are protected by cgroup_mutex */
303 static struct move_charge_struct
{
304 spinlock_t lock
; /* for from, to */
305 struct mem_cgroup
*from
;
306 struct mem_cgroup
*to
;
307 unsigned long precharge
;
308 unsigned long moved_charge
;
309 unsigned long moved_swap
;
310 struct task_struct
*moving_task
; /* a task moving charges */
311 wait_queue_head_t waitq
; /* a waitq for other context */
313 .lock
= __SPIN_LOCK_UNLOCKED(mc
.lock
),
314 .waitq
= __WAIT_QUEUE_HEAD_INITIALIZER(mc
.waitq
),
317 static bool move_anon(void)
319 return test_bit(MOVE_CHARGE_TYPE_ANON
,
320 &mc
.to
->move_charge_at_immigrate
);
323 static bool move_file(void)
325 return test_bit(MOVE_CHARGE_TYPE_FILE
,
326 &mc
.to
->move_charge_at_immigrate
);
330 * Maximum loops in mem_cgroup_hierarchical_reclaim(), used for soft
331 * limit reclaim to prevent infinite loops, if they ever occur.
333 #define MEM_CGROUP_MAX_RECLAIM_LOOPS (100)
334 #define MEM_CGROUP_MAX_SOFT_LIMIT_RECLAIM_LOOPS (2)
337 MEM_CGROUP_CHARGE_TYPE_CACHE
= 0,
338 MEM_CGROUP_CHARGE_TYPE_MAPPED
,
339 MEM_CGROUP_CHARGE_TYPE_SHMEM
, /* used by page migration of shmem */
340 MEM_CGROUP_CHARGE_TYPE_FORCE
, /* used by force_empty */
341 MEM_CGROUP_CHARGE_TYPE_SWAPOUT
, /* for accounting swapcache */
342 MEM_CGROUP_CHARGE_TYPE_DROP
, /* a page was unused swap cache */
346 /* for encoding cft->private value on file */
349 #define _OOM_TYPE (2)
350 #define MEMFILE_PRIVATE(x, val) (((x) << 16) | (val))
351 #define MEMFILE_TYPE(val) (((val) >> 16) & 0xffff)
352 #define MEMFILE_ATTR(val) ((val) & 0xffff)
353 /* Used for OOM nofiier */
354 #define OOM_CONTROL (0)
357 * Reclaim flags for mem_cgroup_hierarchical_reclaim
359 #define MEM_CGROUP_RECLAIM_NOSWAP_BIT 0x0
360 #define MEM_CGROUP_RECLAIM_NOSWAP (1 << MEM_CGROUP_RECLAIM_NOSWAP_BIT)
361 #define MEM_CGROUP_RECLAIM_SHRINK_BIT 0x1
362 #define MEM_CGROUP_RECLAIM_SHRINK (1 << MEM_CGROUP_RECLAIM_SHRINK_BIT)
363 #define MEM_CGROUP_RECLAIM_SOFT_BIT 0x2
364 #define MEM_CGROUP_RECLAIM_SOFT (1 << MEM_CGROUP_RECLAIM_SOFT_BIT)
366 static void mem_cgroup_get(struct mem_cgroup
*mem
);
367 static void mem_cgroup_put(struct mem_cgroup
*mem
);
368 static struct mem_cgroup
*parent_mem_cgroup(struct mem_cgroup
*mem
);
369 static void drain_all_stock_async(struct mem_cgroup
*mem
);
371 static struct mem_cgroup_per_zone
*
372 mem_cgroup_zoneinfo(struct mem_cgroup
*mem
, int nid
, int zid
)
374 return &mem
->info
.nodeinfo
[nid
]->zoneinfo
[zid
];
377 struct cgroup_subsys_state
*mem_cgroup_css(struct mem_cgroup
*mem
)
382 static struct mem_cgroup_per_zone
*
383 page_cgroup_zoneinfo(struct mem_cgroup
*mem
, struct page
*page
)
385 int nid
= page_to_nid(page
);
386 int zid
= page_zonenum(page
);
388 return mem_cgroup_zoneinfo(mem
, nid
, zid
);
391 static struct mem_cgroup_tree_per_zone
*
392 soft_limit_tree_node_zone(int nid
, int zid
)
394 return &soft_limit_tree
.rb_tree_per_node
[nid
]->rb_tree_per_zone
[zid
];
397 static struct mem_cgroup_tree_per_zone
*
398 soft_limit_tree_from_page(struct page
*page
)
400 int nid
= page_to_nid(page
);
401 int zid
= page_zonenum(page
);
403 return &soft_limit_tree
.rb_tree_per_node
[nid
]->rb_tree_per_zone
[zid
];
407 __mem_cgroup_insert_exceeded(struct mem_cgroup
*mem
,
408 struct mem_cgroup_per_zone
*mz
,
409 struct mem_cgroup_tree_per_zone
*mctz
,
410 unsigned long long new_usage_in_excess
)
412 struct rb_node
**p
= &mctz
->rb_root
.rb_node
;
413 struct rb_node
*parent
= NULL
;
414 struct mem_cgroup_per_zone
*mz_node
;
419 mz
->usage_in_excess
= new_usage_in_excess
;
420 if (!mz
->usage_in_excess
)
424 mz_node
= rb_entry(parent
, struct mem_cgroup_per_zone
,
426 if (mz
->usage_in_excess
< mz_node
->usage_in_excess
)
429 * We can't avoid mem cgroups that are over their soft
430 * limit by the same amount
432 else if (mz
->usage_in_excess
>= mz_node
->usage_in_excess
)
435 rb_link_node(&mz
->tree_node
, parent
, p
);
436 rb_insert_color(&mz
->tree_node
, &mctz
->rb_root
);
441 __mem_cgroup_remove_exceeded(struct mem_cgroup
*mem
,
442 struct mem_cgroup_per_zone
*mz
,
443 struct mem_cgroup_tree_per_zone
*mctz
)
447 rb_erase(&mz
->tree_node
, &mctz
->rb_root
);
452 mem_cgroup_remove_exceeded(struct mem_cgroup
*mem
,
453 struct mem_cgroup_per_zone
*mz
,
454 struct mem_cgroup_tree_per_zone
*mctz
)
456 spin_lock(&mctz
->lock
);
457 __mem_cgroup_remove_exceeded(mem
, mz
, mctz
);
458 spin_unlock(&mctz
->lock
);
462 static void mem_cgroup_update_tree(struct mem_cgroup
*mem
, struct page
*page
)
464 unsigned long long excess
;
465 struct mem_cgroup_per_zone
*mz
;
466 struct mem_cgroup_tree_per_zone
*mctz
;
467 int nid
= page_to_nid(page
);
468 int zid
= page_zonenum(page
);
469 mctz
= soft_limit_tree_from_page(page
);
472 * Necessary to update all ancestors when hierarchy is used.
473 * because their event counter is not touched.
475 for (; mem
; mem
= parent_mem_cgroup(mem
)) {
476 mz
= mem_cgroup_zoneinfo(mem
, nid
, zid
);
477 excess
= res_counter_soft_limit_excess(&mem
->res
);
479 * We have to update the tree if mz is on RB-tree or
480 * mem is over its softlimit.
482 if (excess
|| mz
->on_tree
) {
483 spin_lock(&mctz
->lock
);
484 /* if on-tree, remove it */
486 __mem_cgroup_remove_exceeded(mem
, mz
, mctz
);
488 * Insert again. mz->usage_in_excess will be updated.
489 * If excess is 0, no tree ops.
491 __mem_cgroup_insert_exceeded(mem
, mz
, mctz
, excess
);
492 spin_unlock(&mctz
->lock
);
497 static void mem_cgroup_remove_from_trees(struct mem_cgroup
*mem
)
500 struct mem_cgroup_per_zone
*mz
;
501 struct mem_cgroup_tree_per_zone
*mctz
;
503 for_each_node_state(node
, N_POSSIBLE
) {
504 for (zone
= 0; zone
< MAX_NR_ZONES
; zone
++) {
505 mz
= mem_cgroup_zoneinfo(mem
, node
, zone
);
506 mctz
= soft_limit_tree_node_zone(node
, zone
);
507 mem_cgroup_remove_exceeded(mem
, mz
, mctz
);
512 static struct mem_cgroup_per_zone
*
513 __mem_cgroup_largest_soft_limit_node(struct mem_cgroup_tree_per_zone
*mctz
)
515 struct rb_node
*rightmost
= NULL
;
516 struct mem_cgroup_per_zone
*mz
;
520 rightmost
= rb_last(&mctz
->rb_root
);
522 goto done
; /* Nothing to reclaim from */
524 mz
= rb_entry(rightmost
, struct mem_cgroup_per_zone
, tree_node
);
526 * Remove the node now but someone else can add it back,
527 * we will to add it back at the end of reclaim to its correct
528 * position in the tree.
530 __mem_cgroup_remove_exceeded(mz
->mem
, mz
, mctz
);
531 if (!res_counter_soft_limit_excess(&mz
->mem
->res
) ||
532 !css_tryget(&mz
->mem
->css
))
538 static struct mem_cgroup_per_zone
*
539 mem_cgroup_largest_soft_limit_node(struct mem_cgroup_tree_per_zone
*mctz
)
541 struct mem_cgroup_per_zone
*mz
;
543 spin_lock(&mctz
->lock
);
544 mz
= __mem_cgroup_largest_soft_limit_node(mctz
);
545 spin_unlock(&mctz
->lock
);
550 * Implementation Note: reading percpu statistics for memcg.
552 * Both of vmstat[] and percpu_counter has threshold and do periodic
553 * synchronization to implement "quick" read. There are trade-off between
554 * reading cost and precision of value. Then, we may have a chance to implement
555 * a periodic synchronizion of counter in memcg's counter.
557 * But this _read() function is used for user interface now. The user accounts
558 * memory usage by memory cgroup and he _always_ requires exact value because
559 * he accounts memory. Even if we provide quick-and-fuzzy read, we always
560 * have to visit all online cpus and make sum. So, for now, unnecessary
561 * synchronization is not implemented. (just implemented for cpu hotplug)
563 * If there are kernel internal actions which can make use of some not-exact
564 * value, and reading all cpu value can be performance bottleneck in some
565 * common workload, threashold and synchonization as vmstat[] should be
568 static long mem_cgroup_read_stat(struct mem_cgroup
*mem
,
569 enum mem_cgroup_stat_index idx
)
575 for_each_online_cpu(cpu
)
576 val
+= per_cpu(mem
->stat
->count
[idx
], cpu
);
577 #ifdef CONFIG_HOTPLUG_CPU
578 spin_lock(&mem
->pcp_counter_lock
);
579 val
+= mem
->nocpu_base
.count
[idx
];
580 spin_unlock(&mem
->pcp_counter_lock
);
586 static void mem_cgroup_swap_statistics(struct mem_cgroup
*mem
,
589 int val
= (charge
) ? 1 : -1;
590 this_cpu_add(mem
->stat
->count
[MEM_CGROUP_STAT_SWAPOUT
], val
);
593 void mem_cgroup_pgfault(struct mem_cgroup
*mem
, int val
)
595 this_cpu_add(mem
->stat
->events
[MEM_CGROUP_EVENTS_PGFAULT
], val
);
598 void mem_cgroup_pgmajfault(struct mem_cgroup
*mem
, int val
)
600 this_cpu_add(mem
->stat
->events
[MEM_CGROUP_EVENTS_PGMAJFAULT
], val
);
603 static unsigned long mem_cgroup_read_events(struct mem_cgroup
*mem
,
604 enum mem_cgroup_events_index idx
)
606 unsigned long val
= 0;
609 for_each_online_cpu(cpu
)
610 val
+= per_cpu(mem
->stat
->events
[idx
], cpu
);
611 #ifdef CONFIG_HOTPLUG_CPU
612 spin_lock(&mem
->pcp_counter_lock
);
613 val
+= mem
->nocpu_base
.events
[idx
];
614 spin_unlock(&mem
->pcp_counter_lock
);
619 static void mem_cgroup_charge_statistics(struct mem_cgroup
*mem
,
620 bool file
, int nr_pages
)
625 __this_cpu_add(mem
->stat
->count
[MEM_CGROUP_STAT_CACHE
], nr_pages
);
627 __this_cpu_add(mem
->stat
->count
[MEM_CGROUP_STAT_RSS
], nr_pages
);
629 /* pagein of a big page is an event. So, ignore page size */
631 __this_cpu_inc(mem
->stat
->events
[MEM_CGROUP_EVENTS_PGPGIN
]);
633 __this_cpu_inc(mem
->stat
->events
[MEM_CGROUP_EVENTS_PGPGOUT
]);
634 nr_pages
= -nr_pages
; /* for event */
637 __this_cpu_add(mem
->stat
->events
[MEM_CGROUP_EVENTS_COUNT
], nr_pages
);
643 mem_cgroup_zone_nr_lru_pages(struct mem_cgroup
*mem
, int nid
, int zid
,
644 unsigned int lru_mask
)
646 struct mem_cgroup_per_zone
*mz
;
648 unsigned long ret
= 0;
650 mz
= mem_cgroup_zoneinfo(mem
, nid
, zid
);
653 if (BIT(l
) & lru_mask
)
654 ret
+= MEM_CGROUP_ZSTAT(mz
, l
);
660 mem_cgroup_node_nr_lru_pages(struct mem_cgroup
*mem
,
661 int nid
, unsigned int lru_mask
)
666 for (zid
= 0; zid
< MAX_NR_ZONES
; zid
++)
667 total
+= mem_cgroup_zone_nr_lru_pages(mem
, nid
, zid
, lru_mask
);
672 static unsigned long mem_cgroup_nr_lru_pages(struct mem_cgroup
*mem
,
673 unsigned int lru_mask
)
678 for_each_node_state(nid
, N_HIGH_MEMORY
)
679 total
+= mem_cgroup_node_nr_lru_pages(mem
, nid
, lru_mask
);
683 static bool __memcg_event_check(struct mem_cgroup
*mem
, int target
)
685 unsigned long val
, next
;
687 val
= this_cpu_read(mem
->stat
->events
[MEM_CGROUP_EVENTS_COUNT
]);
688 next
= this_cpu_read(mem
->stat
->targets
[target
]);
689 /* from time_after() in jiffies.h */
690 return ((long)next
- (long)val
< 0);
693 static void __mem_cgroup_target_update(struct mem_cgroup
*mem
, int target
)
695 unsigned long val
, next
;
697 val
= this_cpu_read(mem
->stat
->events
[MEM_CGROUP_EVENTS_COUNT
]);
700 case MEM_CGROUP_TARGET_THRESH
:
701 next
= val
+ THRESHOLDS_EVENTS_TARGET
;
703 case MEM_CGROUP_TARGET_SOFTLIMIT
:
704 next
= val
+ SOFTLIMIT_EVENTS_TARGET
;
706 case MEM_CGROUP_TARGET_NUMAINFO
:
707 next
= val
+ NUMAINFO_EVENTS_TARGET
;
713 this_cpu_write(mem
->stat
->targets
[target
], next
);
717 * Check events in order.
720 static void memcg_check_events(struct mem_cgroup
*mem
, struct page
*page
)
722 /* threshold event is triggered in finer grain than soft limit */
723 if (unlikely(__memcg_event_check(mem
, MEM_CGROUP_TARGET_THRESH
))) {
724 mem_cgroup_threshold(mem
);
725 __mem_cgroup_target_update(mem
, MEM_CGROUP_TARGET_THRESH
);
726 if (unlikely(__memcg_event_check(mem
,
727 MEM_CGROUP_TARGET_SOFTLIMIT
))) {
728 mem_cgroup_update_tree(mem
, page
);
729 __mem_cgroup_target_update(mem
,
730 MEM_CGROUP_TARGET_SOFTLIMIT
);
733 if (unlikely(__memcg_event_check(mem
,
734 MEM_CGROUP_TARGET_NUMAINFO
))) {
735 atomic_inc(&mem
->numainfo_events
);
736 __mem_cgroup_target_update(mem
,
737 MEM_CGROUP_TARGET_NUMAINFO
);
743 static struct mem_cgroup
*mem_cgroup_from_cont(struct cgroup
*cont
)
745 return container_of(cgroup_subsys_state(cont
,
746 mem_cgroup_subsys_id
), struct mem_cgroup
,
750 struct mem_cgroup
*mem_cgroup_from_task(struct task_struct
*p
)
753 * mm_update_next_owner() may clear mm->owner to NULL
754 * if it races with swapoff, page migration, etc.
755 * So this can be called with p == NULL.
760 return container_of(task_subsys_state(p
, mem_cgroup_subsys_id
),
761 struct mem_cgroup
, css
);
764 struct mem_cgroup
*try_get_mem_cgroup_from_mm(struct mm_struct
*mm
)
766 struct mem_cgroup
*mem
= NULL
;
771 * Because we have no locks, mm->owner's may be being moved to other
772 * cgroup. We use css_tryget() here even if this looks
773 * pessimistic (rather than adding locks here).
777 mem
= mem_cgroup_from_task(rcu_dereference(mm
->owner
));
780 } while (!css_tryget(&mem
->css
));
785 /* The caller has to guarantee "mem" exists before calling this */
786 static struct mem_cgroup
*mem_cgroup_start_loop(struct mem_cgroup
*mem
)
788 struct cgroup_subsys_state
*css
;
791 if (!mem
) /* ROOT cgroup has the smallest ID */
792 return root_mem_cgroup
; /*css_put/get against root is ignored*/
793 if (!mem
->use_hierarchy
) {
794 if (css_tryget(&mem
->css
))
800 * searching a memory cgroup which has the smallest ID under given
801 * ROOT cgroup. (ID >= 1)
803 css
= css_get_next(&mem_cgroup_subsys
, 1, &mem
->css
, &found
);
804 if (css
&& css_tryget(css
))
805 mem
= container_of(css
, struct mem_cgroup
, css
);
812 static struct mem_cgroup
*mem_cgroup_get_next(struct mem_cgroup
*iter
,
813 struct mem_cgroup
*root
,
816 int nextid
= css_id(&iter
->css
) + 1;
819 struct cgroup_subsys_state
*css
;
821 hierarchy_used
= iter
->use_hierarchy
;
824 /* If no ROOT, walk all, ignore hierarchy */
825 if (!cond
|| (root
&& !hierarchy_used
))
829 root
= root_mem_cgroup
;
835 css
= css_get_next(&mem_cgroup_subsys
, nextid
,
837 if (css
&& css_tryget(css
))
838 iter
= container_of(css
, struct mem_cgroup
, css
);
840 /* If css is NULL, no more cgroups will be found */
842 } while (css
&& !iter
);
847 * for_eacn_mem_cgroup_tree() for visiting all cgroup under tree. Please
848 * be careful that "break" loop is not allowed. We have reference count.
849 * Instead of that modify "cond" to be false and "continue" to exit the loop.
851 #define for_each_mem_cgroup_tree_cond(iter, root, cond) \
852 for (iter = mem_cgroup_start_loop(root);\
854 iter = mem_cgroup_get_next(iter, root, cond))
856 #define for_each_mem_cgroup_tree(iter, root) \
857 for_each_mem_cgroup_tree_cond(iter, root, true)
859 #define for_each_mem_cgroup_all(iter) \
860 for_each_mem_cgroup_tree_cond(iter, NULL, true)
863 static inline bool mem_cgroup_is_root(struct mem_cgroup
*mem
)
865 return (mem
== root_mem_cgroup
);
868 void mem_cgroup_count_vm_event(struct mm_struct
*mm
, enum vm_event_item idx
)
870 struct mem_cgroup
*mem
;
876 mem
= mem_cgroup_from_task(rcu_dereference(mm
->owner
));
882 mem_cgroup_pgmajfault(mem
, 1);
885 mem_cgroup_pgfault(mem
, 1);
893 EXPORT_SYMBOL(mem_cgroup_count_vm_event
);
896 * Following LRU functions are allowed to be used without PCG_LOCK.
897 * Operations are called by routine of global LRU independently from memcg.
898 * What we have to take care of here is validness of pc->mem_cgroup.
900 * Changes to pc->mem_cgroup happens when
903 * In typical case, "charge" is done before add-to-lru. Exception is SwapCache.
904 * It is added to LRU before charge.
905 * If PCG_USED bit is not set, page_cgroup is not added to this private LRU.
906 * When moving account, the page is not on LRU. It's isolated.
909 void mem_cgroup_del_lru_list(struct page
*page
, enum lru_list lru
)
911 struct page_cgroup
*pc
;
912 struct mem_cgroup_per_zone
*mz
;
914 if (mem_cgroup_disabled())
916 pc
= lookup_page_cgroup(page
);
917 /* can happen while we handle swapcache. */
918 if (!TestClearPageCgroupAcctLRU(pc
))
920 VM_BUG_ON(!pc
->mem_cgroup
);
922 * We don't check PCG_USED bit. It's cleared when the "page" is finally
923 * removed from global LRU.
925 mz
= page_cgroup_zoneinfo(pc
->mem_cgroup
, page
);
926 /* huge page split is done under lru_lock. so, we have no races. */
927 MEM_CGROUP_ZSTAT(mz
, lru
) -= 1 << compound_order(page
);
928 if (mem_cgroup_is_root(pc
->mem_cgroup
))
930 VM_BUG_ON(list_empty(&pc
->lru
));
931 list_del_init(&pc
->lru
);
934 void mem_cgroup_del_lru(struct page
*page
)
936 mem_cgroup_del_lru_list(page
, page_lru(page
));
940 * Writeback is about to end against a page which has been marked for immediate
941 * reclaim. If it still appears to be reclaimable, move it to the tail of the
944 void mem_cgroup_rotate_reclaimable_page(struct page
*page
)
946 struct mem_cgroup_per_zone
*mz
;
947 struct page_cgroup
*pc
;
948 enum lru_list lru
= page_lru(page
);
950 if (mem_cgroup_disabled())
953 pc
= lookup_page_cgroup(page
);
954 /* unused or root page is not rotated. */
955 if (!PageCgroupUsed(pc
))
957 /* Ensure pc->mem_cgroup is visible after reading PCG_USED. */
959 if (mem_cgroup_is_root(pc
->mem_cgroup
))
961 mz
= page_cgroup_zoneinfo(pc
->mem_cgroup
, page
);
962 list_move_tail(&pc
->lru
, &mz
->lists
[lru
]);
965 void mem_cgroup_rotate_lru_list(struct page
*page
, enum lru_list lru
)
967 struct mem_cgroup_per_zone
*mz
;
968 struct page_cgroup
*pc
;
970 if (mem_cgroup_disabled())
973 pc
= lookup_page_cgroup(page
);
974 /* unused or root page is not rotated. */
975 if (!PageCgroupUsed(pc
))
977 /* Ensure pc->mem_cgroup is visible after reading PCG_USED. */
979 if (mem_cgroup_is_root(pc
->mem_cgroup
))
981 mz
= page_cgroup_zoneinfo(pc
->mem_cgroup
, page
);
982 list_move(&pc
->lru
, &mz
->lists
[lru
]);
985 void mem_cgroup_add_lru_list(struct page
*page
, enum lru_list lru
)
987 struct page_cgroup
*pc
;
988 struct mem_cgroup_per_zone
*mz
;
990 if (mem_cgroup_disabled())
992 pc
= lookup_page_cgroup(page
);
993 VM_BUG_ON(PageCgroupAcctLRU(pc
));
994 if (!PageCgroupUsed(pc
))
996 /* Ensure pc->mem_cgroup is visible after reading PCG_USED. */
998 mz
= page_cgroup_zoneinfo(pc
->mem_cgroup
, page
);
999 /* huge page split is done under lru_lock. so, we have no races. */
1000 MEM_CGROUP_ZSTAT(mz
, lru
) += 1 << compound_order(page
);
1001 SetPageCgroupAcctLRU(pc
);
1002 if (mem_cgroup_is_root(pc
->mem_cgroup
))
1004 list_add(&pc
->lru
, &mz
->lists
[lru
]);
1008 * At handling SwapCache and other FUSE stuff, pc->mem_cgroup may be changed
1009 * while it's linked to lru because the page may be reused after it's fully
1010 * uncharged. To handle that, unlink page_cgroup from LRU when charge it again.
1011 * It's done under lock_page and expected that zone->lru_lock isnever held.
1013 static void mem_cgroup_lru_del_before_commit(struct page
*page
)
1015 unsigned long flags
;
1016 struct zone
*zone
= page_zone(page
);
1017 struct page_cgroup
*pc
= lookup_page_cgroup(page
);
1020 * Doing this check without taking ->lru_lock seems wrong but this
1021 * is safe. Because if page_cgroup's USED bit is unset, the page
1022 * will not be added to any memcg's LRU. If page_cgroup's USED bit is
1023 * set, the commit after this will fail, anyway.
1024 * This all charge/uncharge is done under some mutual execustion.
1025 * So, we don't need to taking care of changes in USED bit.
1027 if (likely(!PageLRU(page
)))
1030 spin_lock_irqsave(&zone
->lru_lock
, flags
);
1032 * Forget old LRU when this page_cgroup is *not* used. This Used bit
1033 * is guarded by lock_page() because the page is SwapCache.
1035 if (!PageCgroupUsed(pc
))
1036 mem_cgroup_del_lru_list(page
, page_lru(page
));
1037 spin_unlock_irqrestore(&zone
->lru_lock
, flags
);
1040 static void mem_cgroup_lru_add_after_commit(struct page
*page
)
1042 unsigned long flags
;
1043 struct zone
*zone
= page_zone(page
);
1044 struct page_cgroup
*pc
= lookup_page_cgroup(page
);
1046 /* taking care of that the page is added to LRU while we commit it */
1047 if (likely(!PageLRU(page
)))
1049 spin_lock_irqsave(&zone
->lru_lock
, flags
);
1050 /* link when the page is linked to LRU but page_cgroup isn't */
1051 if (PageLRU(page
) && !PageCgroupAcctLRU(pc
))
1052 mem_cgroup_add_lru_list(page
, page_lru(page
));
1053 spin_unlock_irqrestore(&zone
->lru_lock
, flags
);
1057 void mem_cgroup_move_lists(struct page
*page
,
1058 enum lru_list from
, enum lru_list to
)
1060 if (mem_cgroup_disabled())
1062 mem_cgroup_del_lru_list(page
, from
);
1063 mem_cgroup_add_lru_list(page
, to
);
1066 int task_in_mem_cgroup(struct task_struct
*task
, const struct mem_cgroup
*mem
)
1069 struct mem_cgroup
*curr
= NULL
;
1070 struct task_struct
*p
;
1072 p
= find_lock_task_mm(task
);
1075 curr
= try_get_mem_cgroup_from_mm(p
->mm
);
1080 * We should check use_hierarchy of "mem" not "curr". Because checking
1081 * use_hierarchy of "curr" here make this function true if hierarchy is
1082 * enabled in "curr" and "curr" is a child of "mem" in *cgroup*
1083 * hierarchy(even if use_hierarchy is disabled in "mem").
1085 if (mem
->use_hierarchy
)
1086 ret
= css_is_ancestor(&curr
->css
, &mem
->css
);
1088 ret
= (curr
== mem
);
1089 css_put(&curr
->css
);
1093 static int calc_inactive_ratio(struct mem_cgroup
*memcg
, unsigned long *present_pages
)
1095 unsigned long active
;
1096 unsigned long inactive
;
1098 unsigned long inactive_ratio
;
1100 inactive
= mem_cgroup_nr_lru_pages(memcg
, BIT(LRU_INACTIVE_ANON
));
1101 active
= mem_cgroup_nr_lru_pages(memcg
, BIT(LRU_ACTIVE_ANON
));
1103 gb
= (inactive
+ active
) >> (30 - PAGE_SHIFT
);
1105 inactive_ratio
= int_sqrt(10 * gb
);
1109 if (present_pages
) {
1110 present_pages
[0] = inactive
;
1111 present_pages
[1] = active
;
1114 return inactive_ratio
;
1117 int mem_cgroup_inactive_anon_is_low(struct mem_cgroup
*memcg
)
1119 unsigned long active
;
1120 unsigned long inactive
;
1121 unsigned long present_pages
[2];
1122 unsigned long inactive_ratio
;
1124 inactive_ratio
= calc_inactive_ratio(memcg
, present_pages
);
1126 inactive
= present_pages
[0];
1127 active
= present_pages
[1];
1129 if (inactive
* inactive_ratio
< active
)
1135 int mem_cgroup_inactive_file_is_low(struct mem_cgroup
*memcg
)
1137 unsigned long active
;
1138 unsigned long inactive
;
1140 inactive
= mem_cgroup_nr_lru_pages(memcg
, BIT(LRU_INACTIVE_FILE
));
1141 active
= mem_cgroup_nr_lru_pages(memcg
, BIT(LRU_ACTIVE_FILE
));
1143 return (active
> inactive
);
1146 struct zone_reclaim_stat
*mem_cgroup_get_reclaim_stat(struct mem_cgroup
*memcg
,
1149 int nid
= zone_to_nid(zone
);
1150 int zid
= zone_idx(zone
);
1151 struct mem_cgroup_per_zone
*mz
= mem_cgroup_zoneinfo(memcg
, nid
, zid
);
1153 return &mz
->reclaim_stat
;
1156 struct zone_reclaim_stat
*
1157 mem_cgroup_get_reclaim_stat_from_page(struct page
*page
)
1159 struct page_cgroup
*pc
;
1160 struct mem_cgroup_per_zone
*mz
;
1162 if (mem_cgroup_disabled())
1165 pc
= lookup_page_cgroup(page
);
1166 if (!PageCgroupUsed(pc
))
1168 /* Ensure pc->mem_cgroup is visible after reading PCG_USED. */
1170 mz
= page_cgroup_zoneinfo(pc
->mem_cgroup
, page
);
1171 return &mz
->reclaim_stat
;
1174 unsigned long mem_cgroup_isolate_pages(unsigned long nr_to_scan
,
1175 struct list_head
*dst
,
1176 unsigned long *scanned
, int order
,
1177 int mode
, struct zone
*z
,
1178 struct mem_cgroup
*mem_cont
,
1179 int active
, int file
)
1181 unsigned long nr_taken
= 0;
1185 struct list_head
*src
;
1186 struct page_cgroup
*pc
, *tmp
;
1187 int nid
= zone_to_nid(z
);
1188 int zid
= zone_idx(z
);
1189 struct mem_cgroup_per_zone
*mz
;
1190 int lru
= LRU_FILE
* file
+ active
;
1194 mz
= mem_cgroup_zoneinfo(mem_cont
, nid
, zid
);
1195 src
= &mz
->lists
[lru
];
1198 list_for_each_entry_safe_reverse(pc
, tmp
, src
, lru
) {
1199 if (scan
>= nr_to_scan
)
1202 if (unlikely(!PageCgroupUsed(pc
)))
1205 page
= lookup_cgroup_page(pc
);
1207 if (unlikely(!PageLRU(page
)))
1211 ret
= __isolate_lru_page(page
, mode
, file
);
1214 list_move(&page
->lru
, dst
);
1215 mem_cgroup_del_lru(page
);
1216 nr_taken
+= hpage_nr_pages(page
);
1219 /* we don't affect global LRU but rotate in our LRU */
1220 mem_cgroup_rotate_lru_list(page
, page_lru(page
));
1229 trace_mm_vmscan_memcg_isolate(0, nr_to_scan
, scan
, nr_taken
,
1235 #define mem_cgroup_from_res_counter(counter, member) \
1236 container_of(counter, struct mem_cgroup, member)
1239 * mem_cgroup_margin - calculate chargeable space of a memory cgroup
1240 * @mem: the memory cgroup
1242 * Returns the maximum amount of memory @mem can be charged with, in
1245 static unsigned long mem_cgroup_margin(struct mem_cgroup
*mem
)
1247 unsigned long long margin
;
1249 margin
= res_counter_margin(&mem
->res
);
1250 if (do_swap_account
)
1251 margin
= min(margin
, res_counter_margin(&mem
->memsw
));
1252 return margin
>> PAGE_SHIFT
;
1255 int mem_cgroup_swappiness(struct mem_cgroup
*memcg
)
1257 struct cgroup
*cgrp
= memcg
->css
.cgroup
;
1260 if (cgrp
->parent
== NULL
)
1261 return vm_swappiness
;
1263 return memcg
->swappiness
;
1266 static void mem_cgroup_start_move(struct mem_cgroup
*mem
)
1271 spin_lock(&mem
->pcp_counter_lock
);
1272 for_each_online_cpu(cpu
)
1273 per_cpu(mem
->stat
->count
[MEM_CGROUP_ON_MOVE
], cpu
) += 1;
1274 mem
->nocpu_base
.count
[MEM_CGROUP_ON_MOVE
] += 1;
1275 spin_unlock(&mem
->pcp_counter_lock
);
1281 static void mem_cgroup_end_move(struct mem_cgroup
*mem
)
1288 spin_lock(&mem
->pcp_counter_lock
);
1289 for_each_online_cpu(cpu
)
1290 per_cpu(mem
->stat
->count
[MEM_CGROUP_ON_MOVE
], cpu
) -= 1;
1291 mem
->nocpu_base
.count
[MEM_CGROUP_ON_MOVE
] -= 1;
1292 spin_unlock(&mem
->pcp_counter_lock
);
1296 * 2 routines for checking "mem" is under move_account() or not.
1298 * mem_cgroup_stealed() - checking a cgroup is mc.from or not. This is used
1299 * for avoiding race in accounting. If true,
1300 * pc->mem_cgroup may be overwritten.
1302 * mem_cgroup_under_move() - checking a cgroup is mc.from or mc.to or
1303 * under hierarchy of moving cgroups. This is for
1304 * waiting at hith-memory prressure caused by "move".
1307 static bool mem_cgroup_stealed(struct mem_cgroup
*mem
)
1309 VM_BUG_ON(!rcu_read_lock_held());
1310 return this_cpu_read(mem
->stat
->count
[MEM_CGROUP_ON_MOVE
]) > 0;
1313 static bool mem_cgroup_under_move(struct mem_cgroup
*mem
)
1315 struct mem_cgroup
*from
;
1316 struct mem_cgroup
*to
;
1319 * Unlike task_move routines, we access mc.to, mc.from not under
1320 * mutual exclusion by cgroup_mutex. Here, we take spinlock instead.
1322 spin_lock(&mc
.lock
);
1327 if (from
== mem
|| to
== mem
1328 || (mem
->use_hierarchy
&& css_is_ancestor(&from
->css
, &mem
->css
))
1329 || (mem
->use_hierarchy
&& css_is_ancestor(&to
->css
, &mem
->css
)))
1332 spin_unlock(&mc
.lock
);
1336 static bool mem_cgroup_wait_acct_move(struct mem_cgroup
*mem
)
1338 if (mc
.moving_task
&& current
!= mc
.moving_task
) {
1339 if (mem_cgroup_under_move(mem
)) {
1341 prepare_to_wait(&mc
.waitq
, &wait
, TASK_INTERRUPTIBLE
);
1342 /* moving charge context might have finished. */
1345 finish_wait(&mc
.waitq
, &wait
);
1353 * mem_cgroup_print_oom_info: Called from OOM with tasklist_lock held in read mode.
1354 * @memcg: The memory cgroup that went over limit
1355 * @p: Task that is going to be killed
1357 * NOTE: @memcg and @p's mem_cgroup can be different when hierarchy is
1360 void mem_cgroup_print_oom_info(struct mem_cgroup
*memcg
, struct task_struct
*p
)
1362 struct cgroup
*task_cgrp
;
1363 struct cgroup
*mem_cgrp
;
1365 * Need a buffer in BSS, can't rely on allocations. The code relies
1366 * on the assumption that OOM is serialized for memory controller.
1367 * If this assumption is broken, revisit this code.
1369 static char memcg_name
[PATH_MAX
];
1378 mem_cgrp
= memcg
->css
.cgroup
;
1379 task_cgrp
= task_cgroup(p
, mem_cgroup_subsys_id
);
1381 ret
= cgroup_path(task_cgrp
, memcg_name
, PATH_MAX
);
1384 * Unfortunately, we are unable to convert to a useful name
1385 * But we'll still print out the usage information
1392 printk(KERN_INFO
"Task in %s killed", memcg_name
);
1395 ret
= cgroup_path(mem_cgrp
, memcg_name
, PATH_MAX
);
1403 * Continues from above, so we don't need an KERN_ level
1405 printk(KERN_CONT
" as a result of limit of %s\n", memcg_name
);
1408 printk(KERN_INFO
"memory: usage %llukB, limit %llukB, failcnt %llu\n",
1409 res_counter_read_u64(&memcg
->res
, RES_USAGE
) >> 10,
1410 res_counter_read_u64(&memcg
->res
, RES_LIMIT
) >> 10,
1411 res_counter_read_u64(&memcg
->res
, RES_FAILCNT
));
1412 printk(KERN_INFO
"memory+swap: usage %llukB, limit %llukB, "
1414 res_counter_read_u64(&memcg
->memsw
, RES_USAGE
) >> 10,
1415 res_counter_read_u64(&memcg
->memsw
, RES_LIMIT
) >> 10,
1416 res_counter_read_u64(&memcg
->memsw
, RES_FAILCNT
));
1420 * This function returns the number of memcg under hierarchy tree. Returns
1421 * 1(self count) if no children.
1423 static int mem_cgroup_count_children(struct mem_cgroup
*mem
)
1426 struct mem_cgroup
*iter
;
1428 for_each_mem_cgroup_tree(iter
, mem
)
1434 * Return the memory (and swap, if configured) limit for a memcg.
1436 u64
mem_cgroup_get_limit(struct mem_cgroup
*memcg
)
1441 limit
= res_counter_read_u64(&memcg
->res
, RES_LIMIT
);
1442 limit
+= total_swap_pages
<< PAGE_SHIFT
;
1444 memsw
= res_counter_read_u64(&memcg
->memsw
, RES_LIMIT
);
1446 * If memsw is finite and limits the amount of swap space available
1447 * to this memcg, return that limit.
1449 return min(limit
, memsw
);
1453 * Visit the first child (need not be the first child as per the ordering
1454 * of the cgroup list, since we track last_scanned_child) of @mem and use
1455 * that to reclaim free pages from.
1457 static struct mem_cgroup
*
1458 mem_cgroup_select_victim(struct mem_cgroup
*root_mem
)
1460 struct mem_cgroup
*ret
= NULL
;
1461 struct cgroup_subsys_state
*css
;
1464 if (!root_mem
->use_hierarchy
) {
1465 css_get(&root_mem
->css
);
1471 nextid
= root_mem
->last_scanned_child
+ 1;
1472 css
= css_get_next(&mem_cgroup_subsys
, nextid
, &root_mem
->css
,
1474 if (css
&& css_tryget(css
))
1475 ret
= container_of(css
, struct mem_cgroup
, css
);
1478 /* Updates scanning parameter */
1480 /* this means start scan from ID:1 */
1481 root_mem
->last_scanned_child
= 0;
1483 root_mem
->last_scanned_child
= found
;
1490 * test_mem_cgroup_node_reclaimable
1491 * @mem: the target memcg
1492 * @nid: the node ID to be checked.
1493 * @noswap : specify true here if the user wants flle only information.
1495 * This function returns whether the specified memcg contains any
1496 * reclaimable pages on a node. Returns true if there are any reclaimable
1497 * pages in the node.
1499 static bool test_mem_cgroup_node_reclaimable(struct mem_cgroup
*mem
,
1500 int nid
, bool noswap
)
1502 if (mem_cgroup_node_nr_lru_pages(mem
, nid
, LRU_ALL_FILE
))
1504 if (noswap
|| !total_swap_pages
)
1506 if (mem_cgroup_node_nr_lru_pages(mem
, nid
, LRU_ALL_ANON
))
1511 #if MAX_NUMNODES > 1
1514 * Always updating the nodemask is not very good - even if we have an empty
1515 * list or the wrong list here, we can start from some node and traverse all
1516 * nodes based on the zonelist. So update the list loosely once per 10 secs.
1519 static void mem_cgroup_may_update_nodemask(struct mem_cgroup
*mem
)
1523 * numainfo_events > 0 means there was at least NUMAINFO_EVENTS_TARGET
1524 * pagein/pageout changes since the last update.
1526 if (!atomic_read(&mem
->numainfo_events
))
1528 if (atomic_inc_return(&mem
->numainfo_updating
) > 1)
1531 /* make a nodemask where this memcg uses memory from */
1532 mem
->scan_nodes
= node_states
[N_HIGH_MEMORY
];
1534 for_each_node_mask(nid
, node_states
[N_HIGH_MEMORY
]) {
1536 if (!test_mem_cgroup_node_reclaimable(mem
, nid
, false))
1537 node_clear(nid
, mem
->scan_nodes
);
1540 atomic_set(&mem
->numainfo_events
, 0);
1541 atomic_set(&mem
->numainfo_updating
, 0);
1545 * Selecting a node where we start reclaim from. Because what we need is just
1546 * reducing usage counter, start from anywhere is O,K. Considering
1547 * memory reclaim from current node, there are pros. and cons.
1549 * Freeing memory from current node means freeing memory from a node which
1550 * we'll use or we've used. So, it may make LRU bad. And if several threads
1551 * hit limits, it will see a contention on a node. But freeing from remote
1552 * node means more costs for memory reclaim because of memory latency.
1554 * Now, we use round-robin. Better algorithm is welcomed.
1556 int mem_cgroup_select_victim_node(struct mem_cgroup
*mem
)
1560 mem_cgroup_may_update_nodemask(mem
);
1561 node
= mem
->last_scanned_node
;
1563 node
= next_node(node
, mem
->scan_nodes
);
1564 if (node
== MAX_NUMNODES
)
1565 node
= first_node(mem
->scan_nodes
);
1567 * We call this when we hit limit, not when pages are added to LRU.
1568 * No LRU may hold pages because all pages are UNEVICTABLE or
1569 * memcg is too small and all pages are not on LRU. In that case,
1570 * we use curret node.
1572 if (unlikely(node
== MAX_NUMNODES
))
1573 node
= numa_node_id();
1575 mem
->last_scanned_node
= node
;
1580 * Check all nodes whether it contains reclaimable pages or not.
1581 * For quick scan, we make use of scan_nodes. This will allow us to skip
1582 * unused nodes. But scan_nodes is lazily updated and may not cotain
1583 * enough new information. We need to do double check.
1585 bool mem_cgroup_reclaimable(struct mem_cgroup
*mem
, bool noswap
)
1590 * quick check...making use of scan_node.
1591 * We can skip unused nodes.
1593 if (!nodes_empty(mem
->scan_nodes
)) {
1594 for (nid
= first_node(mem
->scan_nodes
);
1596 nid
= next_node(nid
, mem
->scan_nodes
)) {
1598 if (test_mem_cgroup_node_reclaimable(mem
, nid
, noswap
))
1603 * Check rest of nodes.
1605 for_each_node_state(nid
, N_HIGH_MEMORY
) {
1606 if (node_isset(nid
, mem
->scan_nodes
))
1608 if (test_mem_cgroup_node_reclaimable(mem
, nid
, noswap
))
1615 int mem_cgroup_select_victim_node(struct mem_cgroup
*mem
)
1620 bool mem_cgroup_reclaimable(struct mem_cgroup
*mem
, bool noswap
)
1622 return test_mem_cgroup_node_reclaimable(mem
, 0, noswap
);
1627 * Scan the hierarchy if needed to reclaim memory. We remember the last child
1628 * we reclaimed from, so that we don't end up penalizing one child extensively
1629 * based on its position in the children list.
1631 * root_mem is the original ancestor that we've been reclaim from.
1633 * We give up and return to the caller when we visit root_mem twice.
1634 * (other groups can be removed while we're walking....)
1636 * If shrink==true, for avoiding to free too much, this returns immedieately.
1638 static int mem_cgroup_hierarchical_reclaim(struct mem_cgroup
*root_mem
,
1641 unsigned long reclaim_options
,
1642 unsigned long *total_scanned
)
1644 struct mem_cgroup
*victim
;
1647 bool noswap
= reclaim_options
& MEM_CGROUP_RECLAIM_NOSWAP
;
1648 bool shrink
= reclaim_options
& MEM_CGROUP_RECLAIM_SHRINK
;
1649 bool check_soft
= reclaim_options
& MEM_CGROUP_RECLAIM_SOFT
;
1650 unsigned long excess
;
1651 unsigned long nr_scanned
;
1653 excess
= res_counter_soft_limit_excess(&root_mem
->res
) >> PAGE_SHIFT
;
1655 /* If memsw_is_minimum==1, swap-out is of-no-use. */
1656 if (!check_soft
&& root_mem
->memsw_is_minimum
)
1660 victim
= mem_cgroup_select_victim(root_mem
);
1661 if (victim
== root_mem
) {
1664 * We are not draining per cpu cached charges during
1665 * soft limit reclaim because global reclaim doesn't
1666 * care about charges. It tries to free some memory and
1667 * charges will not give any.
1669 if (!check_soft
&& loop
>= 1)
1670 drain_all_stock_async(root_mem
);
1673 * If we have not been able to reclaim
1674 * anything, it might because there are
1675 * no reclaimable pages under this hierarchy
1677 if (!check_soft
|| !total
) {
1678 css_put(&victim
->css
);
1682 * We want to do more targeted reclaim.
1683 * excess >> 2 is not to excessive so as to
1684 * reclaim too much, nor too less that we keep
1685 * coming back to reclaim from this cgroup
1687 if (total
>= (excess
>> 2) ||
1688 (loop
> MEM_CGROUP_MAX_RECLAIM_LOOPS
)) {
1689 css_put(&victim
->css
);
1694 if (!mem_cgroup_reclaimable(victim
, noswap
)) {
1695 /* this cgroup's local usage == 0 */
1696 css_put(&victim
->css
);
1699 /* we use swappiness of local cgroup */
1701 ret
= mem_cgroup_shrink_node_zone(victim
, gfp_mask
,
1702 noswap
, zone
, &nr_scanned
);
1703 *total_scanned
+= nr_scanned
;
1705 ret
= try_to_free_mem_cgroup_pages(victim
, gfp_mask
,
1707 css_put(&victim
->css
);
1709 * At shrinking usage, we can't check we should stop here or
1710 * reclaim more. It's depends on callers. last_scanned_child
1711 * will work enough for keeping fairness under tree.
1717 if (!res_counter_soft_limit_excess(&root_mem
->res
))
1719 } else if (mem_cgroup_margin(root_mem
))
1726 * Check OOM-Killer is already running under our hierarchy.
1727 * If someone is running, return false.
1728 * Has to be called with memcg_oom_lock
1730 static bool mem_cgroup_oom_lock(struct mem_cgroup
*mem
)
1732 int lock_count
= -1;
1733 struct mem_cgroup
*iter
, *failed
= NULL
;
1736 for_each_mem_cgroup_tree_cond(iter
, mem
, cond
) {
1737 bool locked
= iter
->oom_lock
;
1739 iter
->oom_lock
= true;
1740 if (lock_count
== -1)
1741 lock_count
= iter
->oom_lock
;
1742 else if (lock_count
!= locked
) {
1744 * this subtree of our hierarchy is already locked
1745 * so we cannot give a lock.
1757 * OK, we failed to lock the whole subtree so we have to clean up
1758 * what we set up to the failing subtree
1761 for_each_mem_cgroup_tree_cond(iter
, mem
, cond
) {
1762 if (iter
== failed
) {
1766 iter
->oom_lock
= false;
1773 * Has to be called with memcg_oom_lock
1775 static int mem_cgroup_oom_unlock(struct mem_cgroup
*mem
)
1777 struct mem_cgroup
*iter
;
1779 for_each_mem_cgroup_tree(iter
, mem
)
1780 iter
->oom_lock
= false;
1784 static void mem_cgroup_mark_under_oom(struct mem_cgroup
*mem
)
1786 struct mem_cgroup
*iter
;
1788 for_each_mem_cgroup_tree(iter
, mem
)
1789 atomic_inc(&iter
->under_oom
);
1792 static void mem_cgroup_unmark_under_oom(struct mem_cgroup
*mem
)
1794 struct mem_cgroup
*iter
;
1797 * When a new child is created while the hierarchy is under oom,
1798 * mem_cgroup_oom_lock() may not be called. We have to use
1799 * atomic_add_unless() here.
1801 for_each_mem_cgroup_tree(iter
, mem
)
1802 atomic_add_unless(&iter
->under_oom
, -1, 0);
1805 static DEFINE_SPINLOCK(memcg_oom_lock
);
1806 static DECLARE_WAIT_QUEUE_HEAD(memcg_oom_waitq
);
1808 struct oom_wait_info
{
1809 struct mem_cgroup
*mem
;
1813 static int memcg_oom_wake_function(wait_queue_t
*wait
,
1814 unsigned mode
, int sync
, void *arg
)
1816 struct mem_cgroup
*wake_mem
= (struct mem_cgroup
*)arg
;
1817 struct oom_wait_info
*oom_wait_info
;
1819 oom_wait_info
= container_of(wait
, struct oom_wait_info
, wait
);
1821 if (oom_wait_info
->mem
== wake_mem
)
1823 /* if no hierarchy, no match */
1824 if (!oom_wait_info
->mem
->use_hierarchy
|| !wake_mem
->use_hierarchy
)
1827 * Both of oom_wait_info->mem and wake_mem are stable under us.
1828 * Then we can use css_is_ancestor without taking care of RCU.
1830 if (!css_is_ancestor(&oom_wait_info
->mem
->css
, &wake_mem
->css
) &&
1831 !css_is_ancestor(&wake_mem
->css
, &oom_wait_info
->mem
->css
))
1835 return autoremove_wake_function(wait
, mode
, sync
, arg
);
1838 static void memcg_wakeup_oom(struct mem_cgroup
*mem
)
1840 /* for filtering, pass "mem" as argument. */
1841 __wake_up(&memcg_oom_waitq
, TASK_NORMAL
, 0, mem
);
1844 static void memcg_oom_recover(struct mem_cgroup
*mem
)
1846 if (mem
&& atomic_read(&mem
->under_oom
))
1847 memcg_wakeup_oom(mem
);
1851 * try to call OOM killer. returns false if we should exit memory-reclaim loop.
1853 bool mem_cgroup_handle_oom(struct mem_cgroup
*mem
, gfp_t mask
)
1855 struct oom_wait_info owait
;
1856 bool locked
, need_to_kill
;
1859 owait
.wait
.flags
= 0;
1860 owait
.wait
.func
= memcg_oom_wake_function
;
1861 owait
.wait
.private = current
;
1862 INIT_LIST_HEAD(&owait
.wait
.task_list
);
1863 need_to_kill
= true;
1864 mem_cgroup_mark_under_oom(mem
);
1866 /* At first, try to OOM lock hierarchy under mem.*/
1867 spin_lock(&memcg_oom_lock
);
1868 locked
= mem_cgroup_oom_lock(mem
);
1870 * Even if signal_pending(), we can't quit charge() loop without
1871 * accounting. So, UNINTERRUPTIBLE is appropriate. But SIGKILL
1872 * under OOM is always welcomed, use TASK_KILLABLE here.
1874 prepare_to_wait(&memcg_oom_waitq
, &owait
.wait
, TASK_KILLABLE
);
1875 if (!locked
|| mem
->oom_kill_disable
)
1876 need_to_kill
= false;
1878 mem_cgroup_oom_notify(mem
);
1879 spin_unlock(&memcg_oom_lock
);
1882 finish_wait(&memcg_oom_waitq
, &owait
.wait
);
1883 mem_cgroup_out_of_memory(mem
, mask
);
1886 finish_wait(&memcg_oom_waitq
, &owait
.wait
);
1888 spin_lock(&memcg_oom_lock
);
1890 mem_cgroup_oom_unlock(mem
);
1891 memcg_wakeup_oom(mem
);
1892 spin_unlock(&memcg_oom_lock
);
1894 mem_cgroup_unmark_under_oom(mem
);
1896 if (test_thread_flag(TIF_MEMDIE
) || fatal_signal_pending(current
))
1898 /* Give chance to dying process */
1899 schedule_timeout(1);
1904 * Currently used to update mapped file statistics, but the routine can be
1905 * generalized to update other statistics as well.
1907 * Notes: Race condition
1909 * We usually use page_cgroup_lock() for accessing page_cgroup member but
1910 * it tends to be costly. But considering some conditions, we doesn't need
1911 * to do so _always_.
1913 * Considering "charge", lock_page_cgroup() is not required because all
1914 * file-stat operations happen after a page is attached to radix-tree. There
1915 * are no race with "charge".
1917 * Considering "uncharge", we know that memcg doesn't clear pc->mem_cgroup
1918 * at "uncharge" intentionally. So, we always see valid pc->mem_cgroup even
1919 * if there are race with "uncharge". Statistics itself is properly handled
1922 * Considering "move", this is an only case we see a race. To make the race
1923 * small, we check MEM_CGROUP_ON_MOVE percpu value and detect there are
1924 * possibility of race condition. If there is, we take a lock.
1927 void mem_cgroup_update_page_stat(struct page
*page
,
1928 enum mem_cgroup_page_stat_item idx
, int val
)
1930 struct mem_cgroup
*mem
;
1931 struct page_cgroup
*pc
= lookup_page_cgroup(page
);
1932 bool need_unlock
= false;
1933 unsigned long uninitialized_var(flags
);
1939 mem
= pc
->mem_cgroup
;
1940 if (unlikely(!mem
|| !PageCgroupUsed(pc
)))
1942 /* pc->mem_cgroup is unstable ? */
1943 if (unlikely(mem_cgroup_stealed(mem
)) || PageTransHuge(page
)) {
1944 /* take a lock against to access pc->mem_cgroup */
1945 move_lock_page_cgroup(pc
, &flags
);
1947 mem
= pc
->mem_cgroup
;
1948 if (!mem
|| !PageCgroupUsed(pc
))
1953 case MEMCG_NR_FILE_MAPPED
:
1955 SetPageCgroupFileMapped(pc
);
1956 else if (!page_mapped(page
))
1957 ClearPageCgroupFileMapped(pc
);
1958 idx
= MEM_CGROUP_STAT_FILE_MAPPED
;
1964 this_cpu_add(mem
->stat
->count
[idx
], val
);
1967 if (unlikely(need_unlock
))
1968 move_unlock_page_cgroup(pc
, &flags
);
1972 EXPORT_SYMBOL(mem_cgroup_update_page_stat
);
1975 * size of first charge trial. "32" comes from vmscan.c's magic value.
1976 * TODO: maybe necessary to use big numbers in big irons.
1978 #define CHARGE_BATCH 32U
1979 struct memcg_stock_pcp
{
1980 struct mem_cgroup
*cached
; /* this never be root cgroup */
1981 unsigned int nr_pages
;
1982 struct work_struct work
;
1983 unsigned long flags
;
1984 #define FLUSHING_CACHED_CHARGE (0)
1986 static DEFINE_PER_CPU(struct memcg_stock_pcp
, memcg_stock
);
1987 static DEFINE_MUTEX(percpu_charge_mutex
);
1990 * Try to consume stocked charge on this cpu. If success, one page is consumed
1991 * from local stock and true is returned. If the stock is 0 or charges from a
1992 * cgroup which is not current target, returns false. This stock will be
1995 static bool consume_stock(struct mem_cgroup
*mem
)
1997 struct memcg_stock_pcp
*stock
;
2000 stock
= &get_cpu_var(memcg_stock
);
2001 if (mem
== stock
->cached
&& stock
->nr_pages
)
2003 else /* need to call res_counter_charge */
2005 put_cpu_var(memcg_stock
);
2010 * Returns stocks cached in percpu to res_counter and reset cached information.
2012 static void drain_stock(struct memcg_stock_pcp
*stock
)
2014 struct mem_cgroup
*old
= stock
->cached
;
2016 if (stock
->nr_pages
) {
2017 unsigned long bytes
= stock
->nr_pages
* PAGE_SIZE
;
2019 res_counter_uncharge(&old
->res
, bytes
);
2020 if (do_swap_account
)
2021 res_counter_uncharge(&old
->memsw
, bytes
);
2022 stock
->nr_pages
= 0;
2024 stock
->cached
= NULL
;
2028 * This must be called under preempt disabled or must be called by
2029 * a thread which is pinned to local cpu.
2031 static void drain_local_stock(struct work_struct
*dummy
)
2033 struct memcg_stock_pcp
*stock
= &__get_cpu_var(memcg_stock
);
2035 clear_bit(FLUSHING_CACHED_CHARGE
, &stock
->flags
);
2039 * Cache charges(val) which is from res_counter, to local per_cpu area.
2040 * This will be consumed by consume_stock() function, later.
2042 static void refill_stock(struct mem_cgroup
*mem
, unsigned int nr_pages
)
2044 struct memcg_stock_pcp
*stock
= &get_cpu_var(memcg_stock
);
2046 if (stock
->cached
!= mem
) { /* reset if necessary */
2048 stock
->cached
= mem
;
2050 stock
->nr_pages
+= nr_pages
;
2051 put_cpu_var(memcg_stock
);
2055 * Tries to drain stocked charges in other cpus. This function is asynchronous
2056 * and just put a work per cpu for draining localy on each cpu. Caller can
2057 * expects some charges will be back to res_counter later but cannot wait for
2060 static void drain_all_stock_async(struct mem_cgroup
*root_mem
)
2064 * If someone calls draining, avoid adding more kworker runs.
2066 if (!mutex_trylock(&percpu_charge_mutex
))
2068 /* Notify other cpus that system-wide "drain" is running */
2071 * Get a hint for avoiding draining charges on the current cpu,
2072 * which must be exhausted by our charging. It is not required that
2073 * this be a precise check, so we use raw_smp_processor_id() instead of
2074 * getcpu()/putcpu().
2076 curcpu
= raw_smp_processor_id();
2077 for_each_online_cpu(cpu
) {
2078 struct memcg_stock_pcp
*stock
= &per_cpu(memcg_stock
, cpu
);
2079 struct mem_cgroup
*mem
;
2084 mem
= stock
->cached
;
2087 if (mem
!= root_mem
) {
2088 if (!root_mem
->use_hierarchy
)
2090 /* check whether "mem" is under tree of "root_mem" */
2091 if (!css_is_ancestor(&mem
->css
, &root_mem
->css
))
2094 if (!test_and_set_bit(FLUSHING_CACHED_CHARGE
, &stock
->flags
))
2095 schedule_work_on(cpu
, &stock
->work
);
2098 mutex_unlock(&percpu_charge_mutex
);
2099 /* We don't wait for flush_work */
2102 /* This is a synchronous drain interface. */
2103 static void drain_all_stock_sync(void)
2105 /* called when force_empty is called */
2106 mutex_lock(&percpu_charge_mutex
);
2107 schedule_on_each_cpu(drain_local_stock
);
2108 mutex_unlock(&percpu_charge_mutex
);
2112 * This function drains percpu counter value from DEAD cpu and
2113 * move it to local cpu. Note that this function can be preempted.
2115 static void mem_cgroup_drain_pcp_counter(struct mem_cgroup
*mem
, int cpu
)
2119 spin_lock(&mem
->pcp_counter_lock
);
2120 for (i
= 0; i
< MEM_CGROUP_STAT_DATA
; i
++) {
2121 long x
= per_cpu(mem
->stat
->count
[i
], cpu
);
2123 per_cpu(mem
->stat
->count
[i
], cpu
) = 0;
2124 mem
->nocpu_base
.count
[i
] += x
;
2126 for (i
= 0; i
< MEM_CGROUP_EVENTS_NSTATS
; i
++) {
2127 unsigned long x
= per_cpu(mem
->stat
->events
[i
], cpu
);
2129 per_cpu(mem
->stat
->events
[i
], cpu
) = 0;
2130 mem
->nocpu_base
.events
[i
] += x
;
2132 /* need to clear ON_MOVE value, works as a kind of lock. */
2133 per_cpu(mem
->stat
->count
[MEM_CGROUP_ON_MOVE
], cpu
) = 0;
2134 spin_unlock(&mem
->pcp_counter_lock
);
2137 static void synchronize_mem_cgroup_on_move(struct mem_cgroup
*mem
, int cpu
)
2139 int idx
= MEM_CGROUP_ON_MOVE
;
2141 spin_lock(&mem
->pcp_counter_lock
);
2142 per_cpu(mem
->stat
->count
[idx
], cpu
) = mem
->nocpu_base
.count
[idx
];
2143 spin_unlock(&mem
->pcp_counter_lock
);
2146 static int __cpuinit
memcg_cpu_hotplug_callback(struct notifier_block
*nb
,
2147 unsigned long action
,
2150 int cpu
= (unsigned long)hcpu
;
2151 struct memcg_stock_pcp
*stock
;
2152 struct mem_cgroup
*iter
;
2154 if ((action
== CPU_ONLINE
)) {
2155 for_each_mem_cgroup_all(iter
)
2156 synchronize_mem_cgroup_on_move(iter
, cpu
);
2160 if ((action
!= CPU_DEAD
) || action
!= CPU_DEAD_FROZEN
)
2163 for_each_mem_cgroup_all(iter
)
2164 mem_cgroup_drain_pcp_counter(iter
, cpu
);
2166 stock
= &per_cpu(memcg_stock
, cpu
);
2172 /* See __mem_cgroup_try_charge() for details */
2174 CHARGE_OK
, /* success */
2175 CHARGE_RETRY
, /* need to retry but retry is not bad */
2176 CHARGE_NOMEM
, /* we can't do more. return -ENOMEM */
2177 CHARGE_WOULDBLOCK
, /* GFP_WAIT wasn't set and no enough res. */
2178 CHARGE_OOM_DIE
, /* the current is killed because of OOM */
2181 static int mem_cgroup_do_charge(struct mem_cgroup
*mem
, gfp_t gfp_mask
,
2182 unsigned int nr_pages
, bool oom_check
)
2184 unsigned long csize
= nr_pages
* PAGE_SIZE
;
2185 struct mem_cgroup
*mem_over_limit
;
2186 struct res_counter
*fail_res
;
2187 unsigned long flags
= 0;
2190 ret
= res_counter_charge(&mem
->res
, csize
, &fail_res
);
2193 if (!do_swap_account
)
2195 ret
= res_counter_charge(&mem
->memsw
, csize
, &fail_res
);
2199 res_counter_uncharge(&mem
->res
, csize
);
2200 mem_over_limit
= mem_cgroup_from_res_counter(fail_res
, memsw
);
2201 flags
|= MEM_CGROUP_RECLAIM_NOSWAP
;
2203 mem_over_limit
= mem_cgroup_from_res_counter(fail_res
, res
);
2205 * nr_pages can be either a huge page (HPAGE_PMD_NR), a batch
2206 * of regular pages (CHARGE_BATCH), or a single regular page (1).
2208 * Never reclaim on behalf of optional batching, retry with a
2209 * single page instead.
2211 if (nr_pages
== CHARGE_BATCH
)
2212 return CHARGE_RETRY
;
2214 if (!(gfp_mask
& __GFP_WAIT
))
2215 return CHARGE_WOULDBLOCK
;
2217 ret
= mem_cgroup_hierarchical_reclaim(mem_over_limit
, NULL
,
2218 gfp_mask
, flags
, NULL
);
2219 if (mem_cgroup_margin(mem_over_limit
) >= nr_pages
)
2220 return CHARGE_RETRY
;
2222 * Even though the limit is exceeded at this point, reclaim
2223 * may have been able to free some pages. Retry the charge
2224 * before killing the task.
2226 * Only for regular pages, though: huge pages are rather
2227 * unlikely to succeed so close to the limit, and we fall back
2228 * to regular pages anyway in case of failure.
2230 if (nr_pages
== 1 && ret
)
2231 return CHARGE_RETRY
;
2234 * At task move, charge accounts can be doubly counted. So, it's
2235 * better to wait until the end of task_move if something is going on.
2237 if (mem_cgroup_wait_acct_move(mem_over_limit
))
2238 return CHARGE_RETRY
;
2240 /* If we don't need to call oom-killer at el, return immediately */
2242 return CHARGE_NOMEM
;
2244 if (!mem_cgroup_handle_oom(mem_over_limit
, gfp_mask
))
2245 return CHARGE_OOM_DIE
;
2247 return CHARGE_RETRY
;
2251 * Unlike exported interface, "oom" parameter is added. if oom==true,
2252 * oom-killer can be invoked.
2254 static int __mem_cgroup_try_charge(struct mm_struct
*mm
,
2256 unsigned int nr_pages
,
2257 struct mem_cgroup
**memcg
,
2260 unsigned int batch
= max(CHARGE_BATCH
, nr_pages
);
2261 int nr_oom_retries
= MEM_CGROUP_RECLAIM_RETRIES
;
2262 struct mem_cgroup
*mem
= NULL
;
2266 * Unlike gloval-vm's OOM-kill, we're not in memory shortage
2267 * in system level. So, allow to go ahead dying process in addition to
2270 if (unlikely(test_thread_flag(TIF_MEMDIE
)
2271 || fatal_signal_pending(current
)))
2275 * We always charge the cgroup the mm_struct belongs to.
2276 * The mm_struct's mem_cgroup changes on task migration if the
2277 * thread group leader migrates. It's possible that mm is not
2278 * set, if so charge the init_mm (happens for pagecache usage).
2283 if (*memcg
) { /* css should be a valid one */
2285 VM_BUG_ON(css_is_removed(&mem
->css
));
2286 if (mem_cgroup_is_root(mem
))
2288 if (nr_pages
== 1 && consume_stock(mem
))
2292 struct task_struct
*p
;
2295 p
= rcu_dereference(mm
->owner
);
2297 * Because we don't have task_lock(), "p" can exit.
2298 * In that case, "mem" can point to root or p can be NULL with
2299 * race with swapoff. Then, we have small risk of mis-accouning.
2300 * But such kind of mis-account by race always happens because
2301 * we don't have cgroup_mutex(). It's overkill and we allo that
2303 * (*) swapoff at el will charge against mm-struct not against
2304 * task-struct. So, mm->owner can be NULL.
2306 mem
= mem_cgroup_from_task(p
);
2307 if (!mem
|| mem_cgroup_is_root(mem
)) {
2311 if (nr_pages
== 1 && consume_stock(mem
)) {
2313 * It seems dagerous to access memcg without css_get().
2314 * But considering how consume_stok works, it's not
2315 * necessary. If consume_stock success, some charges
2316 * from this memcg are cached on this cpu. So, we
2317 * don't need to call css_get()/css_tryget() before
2318 * calling consume_stock().
2323 /* after here, we may be blocked. we need to get refcnt */
2324 if (!css_tryget(&mem
->css
)) {
2334 /* If killed, bypass charge */
2335 if (fatal_signal_pending(current
)) {
2341 if (oom
&& !nr_oom_retries
) {
2343 nr_oom_retries
= MEM_CGROUP_RECLAIM_RETRIES
;
2346 ret
= mem_cgroup_do_charge(mem
, gfp_mask
, batch
, oom_check
);
2350 case CHARGE_RETRY
: /* not in OOM situation but retry */
2355 case CHARGE_WOULDBLOCK
: /* !__GFP_WAIT */
2358 case CHARGE_NOMEM
: /* OOM routine works */
2363 /* If oom, we never return -ENOMEM */
2366 case CHARGE_OOM_DIE
: /* Killed by OOM Killer */
2370 } while (ret
!= CHARGE_OK
);
2372 if (batch
> nr_pages
)
2373 refill_stock(mem
, batch
- nr_pages
);
2387 * Somemtimes we have to undo a charge we got by try_charge().
2388 * This function is for that and do uncharge, put css's refcnt.
2389 * gotten by try_charge().
2391 static void __mem_cgroup_cancel_charge(struct mem_cgroup
*mem
,
2392 unsigned int nr_pages
)
2394 if (!mem_cgroup_is_root(mem
)) {
2395 unsigned long bytes
= nr_pages
* PAGE_SIZE
;
2397 res_counter_uncharge(&mem
->res
, bytes
);
2398 if (do_swap_account
)
2399 res_counter_uncharge(&mem
->memsw
, bytes
);
2404 * A helper function to get mem_cgroup from ID. must be called under
2405 * rcu_read_lock(). The caller must check css_is_removed() or some if
2406 * it's concern. (dropping refcnt from swap can be called against removed
2409 static struct mem_cgroup
*mem_cgroup_lookup(unsigned short id
)
2411 struct cgroup_subsys_state
*css
;
2413 /* ID 0 is unused ID */
2416 css
= css_lookup(&mem_cgroup_subsys
, id
);
2419 return container_of(css
, struct mem_cgroup
, css
);
2422 struct mem_cgroup
*try_get_mem_cgroup_from_page(struct page
*page
)
2424 struct mem_cgroup
*mem
= NULL
;
2425 struct page_cgroup
*pc
;
2429 VM_BUG_ON(!PageLocked(page
));
2431 pc
= lookup_page_cgroup(page
);
2432 lock_page_cgroup(pc
);
2433 if (PageCgroupUsed(pc
)) {
2434 mem
= pc
->mem_cgroup
;
2435 if (mem
&& !css_tryget(&mem
->css
))
2437 } else if (PageSwapCache(page
)) {
2438 ent
.val
= page_private(page
);
2439 id
= lookup_swap_cgroup(ent
);
2441 mem
= mem_cgroup_lookup(id
);
2442 if (mem
&& !css_tryget(&mem
->css
))
2446 unlock_page_cgroup(pc
);
2450 static void __mem_cgroup_commit_charge(struct mem_cgroup
*mem
,
2452 unsigned int nr_pages
,
2453 struct page_cgroup
*pc
,
2454 enum charge_type ctype
)
2456 lock_page_cgroup(pc
);
2457 if (unlikely(PageCgroupUsed(pc
))) {
2458 unlock_page_cgroup(pc
);
2459 __mem_cgroup_cancel_charge(mem
, nr_pages
);
2463 * we don't need page_cgroup_lock about tail pages, becase they are not
2464 * accessed by any other context at this point.
2466 pc
->mem_cgroup
= mem
;
2468 * We access a page_cgroup asynchronously without lock_page_cgroup().
2469 * Especially when a page_cgroup is taken from a page, pc->mem_cgroup
2470 * is accessed after testing USED bit. To make pc->mem_cgroup visible
2471 * before USED bit, we need memory barrier here.
2472 * See mem_cgroup_add_lru_list(), etc.
2476 case MEM_CGROUP_CHARGE_TYPE_CACHE
:
2477 case MEM_CGROUP_CHARGE_TYPE_SHMEM
:
2478 SetPageCgroupCache(pc
);
2479 SetPageCgroupUsed(pc
);
2481 case MEM_CGROUP_CHARGE_TYPE_MAPPED
:
2482 ClearPageCgroupCache(pc
);
2483 SetPageCgroupUsed(pc
);
2489 mem_cgroup_charge_statistics(mem
, PageCgroupCache(pc
), nr_pages
);
2490 unlock_page_cgroup(pc
);
2492 * "charge_statistics" updated event counter. Then, check it.
2493 * Insert ancestor (and ancestor's ancestors), to softlimit RB-tree.
2494 * if they exceeds softlimit.
2496 memcg_check_events(mem
, page
);
2499 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
2501 #define PCGF_NOCOPY_AT_SPLIT ((1 << PCG_LOCK) | (1 << PCG_MOVE_LOCK) |\
2502 (1 << PCG_ACCT_LRU) | (1 << PCG_MIGRATION))
2504 * Because tail pages are not marked as "used", set it. We're under
2505 * zone->lru_lock, 'splitting on pmd' and compund_lock.
2507 void mem_cgroup_split_huge_fixup(struct page
*head
, struct page
*tail
)
2509 struct page_cgroup
*head_pc
= lookup_page_cgroup(head
);
2510 struct page_cgroup
*tail_pc
= lookup_page_cgroup(tail
);
2511 unsigned long flags
;
2513 if (mem_cgroup_disabled())
2516 * We have no races with charge/uncharge but will have races with
2517 * page state accounting.
2519 move_lock_page_cgroup(head_pc
, &flags
);
2521 tail_pc
->mem_cgroup
= head_pc
->mem_cgroup
;
2522 smp_wmb(); /* see __commit_charge() */
2523 if (PageCgroupAcctLRU(head_pc
)) {
2525 struct mem_cgroup_per_zone
*mz
;
2528 * LRU flags cannot be copied because we need to add tail
2529 *.page to LRU by generic call and our hook will be called.
2530 * We hold lru_lock, then, reduce counter directly.
2532 lru
= page_lru(head
);
2533 mz
= page_cgroup_zoneinfo(head_pc
->mem_cgroup
, head
);
2534 MEM_CGROUP_ZSTAT(mz
, lru
) -= 1;
2536 tail_pc
->flags
= head_pc
->flags
& ~PCGF_NOCOPY_AT_SPLIT
;
2537 move_unlock_page_cgroup(head_pc
, &flags
);
2542 * mem_cgroup_move_account - move account of the page
2544 * @nr_pages: number of regular pages (>1 for huge pages)
2545 * @pc: page_cgroup of the page.
2546 * @from: mem_cgroup which the page is moved from.
2547 * @to: mem_cgroup which the page is moved to. @from != @to.
2548 * @uncharge: whether we should call uncharge and css_put against @from.
2550 * The caller must confirm following.
2551 * - page is not on LRU (isolate_page() is useful.)
2552 * - compound_lock is held when nr_pages > 1
2554 * This function doesn't do "charge" nor css_get to new cgroup. It should be
2555 * done by a caller(__mem_cgroup_try_charge would be useful). If @uncharge is
2556 * true, this function does "uncharge" from old cgroup, but it doesn't if
2557 * @uncharge is false, so a caller should do "uncharge".
2559 static int mem_cgroup_move_account(struct page
*page
,
2560 unsigned int nr_pages
,
2561 struct page_cgroup
*pc
,
2562 struct mem_cgroup
*from
,
2563 struct mem_cgroup
*to
,
2566 unsigned long flags
;
2569 VM_BUG_ON(from
== to
);
2570 VM_BUG_ON(PageLRU(page
));
2572 * The page is isolated from LRU. So, collapse function
2573 * will not handle this page. But page splitting can happen.
2574 * Do this check under compound_page_lock(). The caller should
2578 if (nr_pages
> 1 && !PageTransHuge(page
))
2581 lock_page_cgroup(pc
);
2584 if (!PageCgroupUsed(pc
) || pc
->mem_cgroup
!= from
)
2587 move_lock_page_cgroup(pc
, &flags
);
2589 if (PageCgroupFileMapped(pc
)) {
2590 /* Update mapped_file data for mem_cgroup */
2592 __this_cpu_dec(from
->stat
->count
[MEM_CGROUP_STAT_FILE_MAPPED
]);
2593 __this_cpu_inc(to
->stat
->count
[MEM_CGROUP_STAT_FILE_MAPPED
]);
2596 mem_cgroup_charge_statistics(from
, PageCgroupCache(pc
), -nr_pages
);
2598 /* This is not "cancel", but cancel_charge does all we need. */
2599 __mem_cgroup_cancel_charge(from
, nr_pages
);
2601 /* caller should have done css_get */
2602 pc
->mem_cgroup
= to
;
2603 mem_cgroup_charge_statistics(to
, PageCgroupCache(pc
), nr_pages
);
2605 * We charges against "to" which may not have any tasks. Then, "to"
2606 * can be under rmdir(). But in current implementation, caller of
2607 * this function is just force_empty() and move charge, so it's
2608 * guaranteed that "to" is never removed. So, we don't check rmdir
2611 move_unlock_page_cgroup(pc
, &flags
);
2614 unlock_page_cgroup(pc
);
2618 memcg_check_events(to
, page
);
2619 memcg_check_events(from
, page
);
2625 * move charges to its parent.
2628 static int mem_cgroup_move_parent(struct page
*page
,
2629 struct page_cgroup
*pc
,
2630 struct mem_cgroup
*child
,
2633 struct cgroup
*cg
= child
->css
.cgroup
;
2634 struct cgroup
*pcg
= cg
->parent
;
2635 struct mem_cgroup
*parent
;
2636 unsigned int nr_pages
;
2637 unsigned long uninitialized_var(flags
);
2645 if (!get_page_unless_zero(page
))
2647 if (isolate_lru_page(page
))
2650 nr_pages
= hpage_nr_pages(page
);
2652 parent
= mem_cgroup_from_cont(pcg
);
2653 ret
= __mem_cgroup_try_charge(NULL
, gfp_mask
, nr_pages
, &parent
, false);
2658 flags
= compound_lock_irqsave(page
);
2660 ret
= mem_cgroup_move_account(page
, nr_pages
, pc
, child
, parent
, true);
2662 __mem_cgroup_cancel_charge(parent
, nr_pages
);
2665 compound_unlock_irqrestore(page
, flags
);
2667 putback_lru_page(page
);
2675 * Charge the memory controller for page usage.
2677 * 0 if the charge was successful
2678 * < 0 if the cgroup is over its limit
2680 static int mem_cgroup_charge_common(struct page
*page
, struct mm_struct
*mm
,
2681 gfp_t gfp_mask
, enum charge_type ctype
)
2683 struct mem_cgroup
*mem
= NULL
;
2684 unsigned int nr_pages
= 1;
2685 struct page_cgroup
*pc
;
2689 if (PageTransHuge(page
)) {
2690 nr_pages
<<= compound_order(page
);
2691 VM_BUG_ON(!PageTransHuge(page
));
2693 * Never OOM-kill a process for a huge page. The
2694 * fault handler will fall back to regular pages.
2699 pc
= lookup_page_cgroup(page
);
2700 BUG_ON(!pc
); /* XXX: remove this and move pc lookup into commit */
2702 ret
= __mem_cgroup_try_charge(mm
, gfp_mask
, nr_pages
, &mem
, oom
);
2706 __mem_cgroup_commit_charge(mem
, page
, nr_pages
, pc
, ctype
);
2710 int mem_cgroup_newpage_charge(struct page
*page
,
2711 struct mm_struct
*mm
, gfp_t gfp_mask
)
2713 if (mem_cgroup_disabled())
2716 * If already mapped, we don't have to account.
2717 * If page cache, page->mapping has address_space.
2718 * But page->mapping may have out-of-use anon_vma pointer,
2719 * detecit it by PageAnon() check. newly-mapped-anon's page->mapping
2722 if (page_mapped(page
) || (page
->mapping
&& !PageAnon(page
)))
2726 return mem_cgroup_charge_common(page
, mm
, gfp_mask
,
2727 MEM_CGROUP_CHARGE_TYPE_MAPPED
);
2731 __mem_cgroup_commit_charge_swapin(struct page
*page
, struct mem_cgroup
*ptr
,
2732 enum charge_type ctype
);
2735 __mem_cgroup_commit_charge_lrucare(struct page
*page
, struct mem_cgroup
*mem
,
2736 enum charge_type ctype
)
2738 struct page_cgroup
*pc
= lookup_page_cgroup(page
);
2740 * In some case, SwapCache, FUSE(splice_buf->radixtree), the page
2741 * is already on LRU. It means the page may on some other page_cgroup's
2742 * LRU. Take care of it.
2744 mem_cgroup_lru_del_before_commit(page
);
2745 __mem_cgroup_commit_charge(mem
, page
, 1, pc
, ctype
);
2746 mem_cgroup_lru_add_after_commit(page
);
2750 int mem_cgroup_cache_charge(struct page
*page
, struct mm_struct
*mm
,
2753 struct mem_cgroup
*mem
= NULL
;
2756 if (mem_cgroup_disabled())
2758 if (PageCompound(page
))
2761 * Corner case handling. This is called from add_to_page_cache()
2762 * in usual. But some FS (shmem) precharges this page before calling it
2763 * and call add_to_page_cache() with GFP_NOWAIT.
2765 * For GFP_NOWAIT case, the page may be pre-charged before calling
2766 * add_to_page_cache(). (See shmem.c) check it here and avoid to call
2767 * charge twice. (It works but has to pay a bit larger cost.)
2768 * And when the page is SwapCache, it should take swap information
2769 * into account. This is under lock_page() now.
2771 if (!(gfp_mask
& __GFP_WAIT
)) {
2772 struct page_cgroup
*pc
;
2774 pc
= lookup_page_cgroup(page
);
2777 lock_page_cgroup(pc
);
2778 if (PageCgroupUsed(pc
)) {
2779 unlock_page_cgroup(pc
);
2782 unlock_page_cgroup(pc
);
2788 if (page_is_file_cache(page
)) {
2789 ret
= __mem_cgroup_try_charge(mm
, gfp_mask
, 1, &mem
, true);
2794 * FUSE reuses pages without going through the final
2795 * put that would remove them from the LRU list, make
2796 * sure that they get relinked properly.
2798 __mem_cgroup_commit_charge_lrucare(page
, mem
,
2799 MEM_CGROUP_CHARGE_TYPE_CACHE
);
2803 if (PageSwapCache(page
)) {
2804 ret
= mem_cgroup_try_charge_swapin(mm
, page
, gfp_mask
, &mem
);
2806 __mem_cgroup_commit_charge_swapin(page
, mem
,
2807 MEM_CGROUP_CHARGE_TYPE_SHMEM
);
2809 ret
= mem_cgroup_charge_common(page
, mm
, gfp_mask
,
2810 MEM_CGROUP_CHARGE_TYPE_SHMEM
);
2816 * While swap-in, try_charge -> commit or cancel, the page is locked.
2817 * And when try_charge() successfully returns, one refcnt to memcg without
2818 * struct page_cgroup is acquired. This refcnt will be consumed by
2819 * "commit()" or removed by "cancel()"
2821 int mem_cgroup_try_charge_swapin(struct mm_struct
*mm
,
2823 gfp_t mask
, struct mem_cgroup
**ptr
)
2825 struct mem_cgroup
*mem
;
2830 if (mem_cgroup_disabled())
2833 if (!do_swap_account
)
2836 * A racing thread's fault, or swapoff, may have already updated
2837 * the pte, and even removed page from swap cache: in those cases
2838 * do_swap_page()'s pte_same() test will fail; but there's also a
2839 * KSM case which does need to charge the page.
2841 if (!PageSwapCache(page
))
2843 mem
= try_get_mem_cgroup_from_page(page
);
2847 ret
= __mem_cgroup_try_charge(NULL
, mask
, 1, ptr
, true);
2853 return __mem_cgroup_try_charge(mm
, mask
, 1, ptr
, true);
2857 __mem_cgroup_commit_charge_swapin(struct page
*page
, struct mem_cgroup
*ptr
,
2858 enum charge_type ctype
)
2860 if (mem_cgroup_disabled())
2864 cgroup_exclude_rmdir(&ptr
->css
);
2866 __mem_cgroup_commit_charge_lrucare(page
, ptr
, ctype
);
2868 * Now swap is on-memory. This means this page may be
2869 * counted both as mem and swap....double count.
2870 * Fix it by uncharging from memsw. Basically, this SwapCache is stable
2871 * under lock_page(). But in do_swap_page()::memory.c, reuse_swap_page()
2872 * may call delete_from_swap_cache() before reach here.
2874 if (do_swap_account
&& PageSwapCache(page
)) {
2875 swp_entry_t ent
= {.val
= page_private(page
)};
2877 struct mem_cgroup
*memcg
;
2879 id
= swap_cgroup_record(ent
, 0);
2881 memcg
= mem_cgroup_lookup(id
);
2884 * This recorded memcg can be obsolete one. So, avoid
2885 * calling css_tryget
2887 if (!mem_cgroup_is_root(memcg
))
2888 res_counter_uncharge(&memcg
->memsw
, PAGE_SIZE
);
2889 mem_cgroup_swap_statistics(memcg
, false);
2890 mem_cgroup_put(memcg
);
2895 * At swapin, we may charge account against cgroup which has no tasks.
2896 * So, rmdir()->pre_destroy() can be called while we do this charge.
2897 * In that case, we need to call pre_destroy() again. check it here.
2899 cgroup_release_and_wakeup_rmdir(&ptr
->css
);
2902 void mem_cgroup_commit_charge_swapin(struct page
*page
, struct mem_cgroup
*ptr
)
2904 __mem_cgroup_commit_charge_swapin(page
, ptr
,
2905 MEM_CGROUP_CHARGE_TYPE_MAPPED
);
2908 void mem_cgroup_cancel_charge_swapin(struct mem_cgroup
*mem
)
2910 if (mem_cgroup_disabled())
2914 __mem_cgroup_cancel_charge(mem
, 1);
2917 static void mem_cgroup_do_uncharge(struct mem_cgroup
*mem
,
2918 unsigned int nr_pages
,
2919 const enum charge_type ctype
)
2921 struct memcg_batch_info
*batch
= NULL
;
2922 bool uncharge_memsw
= true;
2924 /* If swapout, usage of swap doesn't decrease */
2925 if (!do_swap_account
|| ctype
== MEM_CGROUP_CHARGE_TYPE_SWAPOUT
)
2926 uncharge_memsw
= false;
2928 batch
= ¤t
->memcg_batch
;
2930 * In usual, we do css_get() when we remember memcg pointer.
2931 * But in this case, we keep res->usage until end of a series of
2932 * uncharges. Then, it's ok to ignore memcg's refcnt.
2937 * do_batch > 0 when unmapping pages or inode invalidate/truncate.
2938 * In those cases, all pages freed continuously can be expected to be in
2939 * the same cgroup and we have chance to coalesce uncharges.
2940 * But we do uncharge one by one if this is killed by OOM(TIF_MEMDIE)
2941 * because we want to do uncharge as soon as possible.
2944 if (!batch
->do_batch
|| test_thread_flag(TIF_MEMDIE
))
2945 goto direct_uncharge
;
2948 goto direct_uncharge
;
2951 * In typical case, batch->memcg == mem. This means we can
2952 * merge a series of uncharges to an uncharge of res_counter.
2953 * If not, we uncharge res_counter ony by one.
2955 if (batch
->memcg
!= mem
)
2956 goto direct_uncharge
;
2957 /* remember freed charge and uncharge it later */
2960 batch
->memsw_nr_pages
++;
2963 res_counter_uncharge(&mem
->res
, nr_pages
* PAGE_SIZE
);
2965 res_counter_uncharge(&mem
->memsw
, nr_pages
* PAGE_SIZE
);
2966 if (unlikely(batch
->memcg
!= mem
))
2967 memcg_oom_recover(mem
);
2972 * uncharge if !page_mapped(page)
2974 static struct mem_cgroup
*
2975 __mem_cgroup_uncharge_common(struct page
*page
, enum charge_type ctype
)
2977 struct mem_cgroup
*mem
= NULL
;
2978 unsigned int nr_pages
= 1;
2979 struct page_cgroup
*pc
;
2981 if (mem_cgroup_disabled())
2984 if (PageSwapCache(page
))
2987 if (PageTransHuge(page
)) {
2988 nr_pages
<<= compound_order(page
);
2989 VM_BUG_ON(!PageTransHuge(page
));
2992 * Check if our page_cgroup is valid
2994 pc
= lookup_page_cgroup(page
);
2995 if (unlikely(!pc
|| !PageCgroupUsed(pc
)))
2998 lock_page_cgroup(pc
);
3000 mem
= pc
->mem_cgroup
;
3002 if (!PageCgroupUsed(pc
))
3006 case MEM_CGROUP_CHARGE_TYPE_MAPPED
:
3007 case MEM_CGROUP_CHARGE_TYPE_DROP
:
3008 /* See mem_cgroup_prepare_migration() */
3009 if (page_mapped(page
) || PageCgroupMigration(pc
))
3012 case MEM_CGROUP_CHARGE_TYPE_SWAPOUT
:
3013 if (!PageAnon(page
)) { /* Shared memory */
3014 if (page
->mapping
&& !page_is_file_cache(page
))
3016 } else if (page_mapped(page
)) /* Anon */
3023 mem_cgroup_charge_statistics(mem
, PageCgroupCache(pc
), -nr_pages
);
3025 ClearPageCgroupUsed(pc
);
3027 * pc->mem_cgroup is not cleared here. It will be accessed when it's
3028 * freed from LRU. This is safe because uncharged page is expected not
3029 * to be reused (freed soon). Exception is SwapCache, it's handled by
3030 * special functions.
3033 unlock_page_cgroup(pc
);
3035 * even after unlock, we have mem->res.usage here and this memcg
3036 * will never be freed.
3038 memcg_check_events(mem
, page
);
3039 if (do_swap_account
&& ctype
== MEM_CGROUP_CHARGE_TYPE_SWAPOUT
) {
3040 mem_cgroup_swap_statistics(mem
, true);
3041 mem_cgroup_get(mem
);
3043 if (!mem_cgroup_is_root(mem
))
3044 mem_cgroup_do_uncharge(mem
, nr_pages
, ctype
);
3049 unlock_page_cgroup(pc
);
3053 void mem_cgroup_uncharge_page(struct page
*page
)
3056 if (page_mapped(page
))
3058 if (page
->mapping
&& !PageAnon(page
))
3060 __mem_cgroup_uncharge_common(page
, MEM_CGROUP_CHARGE_TYPE_MAPPED
);
3063 void mem_cgroup_uncharge_cache_page(struct page
*page
)
3065 VM_BUG_ON(page_mapped(page
));
3066 VM_BUG_ON(page
->mapping
);
3067 __mem_cgroup_uncharge_common(page
, MEM_CGROUP_CHARGE_TYPE_CACHE
);
3071 * Batch_start/batch_end is called in unmap_page_range/invlidate/trucate.
3072 * In that cases, pages are freed continuously and we can expect pages
3073 * are in the same memcg. All these calls itself limits the number of
3074 * pages freed at once, then uncharge_start/end() is called properly.
3075 * This may be called prural(2) times in a context,
3078 void mem_cgroup_uncharge_start(void)
3080 current
->memcg_batch
.do_batch
++;
3081 /* We can do nest. */
3082 if (current
->memcg_batch
.do_batch
== 1) {
3083 current
->memcg_batch
.memcg
= NULL
;
3084 current
->memcg_batch
.nr_pages
= 0;
3085 current
->memcg_batch
.memsw_nr_pages
= 0;
3089 void mem_cgroup_uncharge_end(void)
3091 struct memcg_batch_info
*batch
= ¤t
->memcg_batch
;
3093 if (!batch
->do_batch
)
3097 if (batch
->do_batch
) /* If stacked, do nothing. */
3103 * This "batch->memcg" is valid without any css_get/put etc...
3104 * bacause we hide charges behind us.
3106 if (batch
->nr_pages
)
3107 res_counter_uncharge(&batch
->memcg
->res
,
3108 batch
->nr_pages
* PAGE_SIZE
);
3109 if (batch
->memsw_nr_pages
)
3110 res_counter_uncharge(&batch
->memcg
->memsw
,
3111 batch
->memsw_nr_pages
* PAGE_SIZE
);
3112 memcg_oom_recover(batch
->memcg
);
3113 /* forget this pointer (for sanity check) */
3114 batch
->memcg
= NULL
;
3119 * called after __delete_from_swap_cache() and drop "page" account.
3120 * memcg information is recorded to swap_cgroup of "ent"
3123 mem_cgroup_uncharge_swapcache(struct page
*page
, swp_entry_t ent
, bool swapout
)
3125 struct mem_cgroup
*memcg
;
3126 int ctype
= MEM_CGROUP_CHARGE_TYPE_SWAPOUT
;
3128 if (!swapout
) /* this was a swap cache but the swap is unused ! */
3129 ctype
= MEM_CGROUP_CHARGE_TYPE_DROP
;
3131 memcg
= __mem_cgroup_uncharge_common(page
, ctype
);
3134 * record memcg information, if swapout && memcg != NULL,
3135 * mem_cgroup_get() was called in uncharge().
3137 if (do_swap_account
&& swapout
&& memcg
)
3138 swap_cgroup_record(ent
, css_id(&memcg
->css
));
3142 #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP
3144 * called from swap_entry_free(). remove record in swap_cgroup and
3145 * uncharge "memsw" account.
3147 void mem_cgroup_uncharge_swap(swp_entry_t ent
)
3149 struct mem_cgroup
*memcg
;
3152 if (!do_swap_account
)
3155 id
= swap_cgroup_record(ent
, 0);
3157 memcg
= mem_cgroup_lookup(id
);
3160 * We uncharge this because swap is freed.
3161 * This memcg can be obsolete one. We avoid calling css_tryget
3163 if (!mem_cgroup_is_root(memcg
))
3164 res_counter_uncharge(&memcg
->memsw
, PAGE_SIZE
);
3165 mem_cgroup_swap_statistics(memcg
, false);
3166 mem_cgroup_put(memcg
);
3172 * mem_cgroup_move_swap_account - move swap charge and swap_cgroup's record.
3173 * @entry: swap entry to be moved
3174 * @from: mem_cgroup which the entry is moved from
3175 * @to: mem_cgroup which the entry is moved to
3176 * @need_fixup: whether we should fixup res_counters and refcounts.
3178 * It succeeds only when the swap_cgroup's record for this entry is the same
3179 * as the mem_cgroup's id of @from.
3181 * Returns 0 on success, -EINVAL on failure.
3183 * The caller must have charged to @to, IOW, called res_counter_charge() about
3184 * both res and memsw, and called css_get().
3186 static int mem_cgroup_move_swap_account(swp_entry_t entry
,
3187 struct mem_cgroup
*from
, struct mem_cgroup
*to
, bool need_fixup
)
3189 unsigned short old_id
, new_id
;
3191 old_id
= css_id(&from
->css
);
3192 new_id
= css_id(&to
->css
);
3194 if (swap_cgroup_cmpxchg(entry
, old_id
, new_id
) == old_id
) {
3195 mem_cgroup_swap_statistics(from
, false);
3196 mem_cgroup_swap_statistics(to
, true);
3198 * This function is only called from task migration context now.
3199 * It postpones res_counter and refcount handling till the end
3200 * of task migration(mem_cgroup_clear_mc()) for performance
3201 * improvement. But we cannot postpone mem_cgroup_get(to)
3202 * because if the process that has been moved to @to does
3203 * swap-in, the refcount of @to might be decreased to 0.
3207 if (!mem_cgroup_is_root(from
))
3208 res_counter_uncharge(&from
->memsw
, PAGE_SIZE
);
3209 mem_cgroup_put(from
);
3211 * we charged both to->res and to->memsw, so we should
3214 if (!mem_cgroup_is_root(to
))
3215 res_counter_uncharge(&to
->res
, PAGE_SIZE
);
3222 static inline int mem_cgroup_move_swap_account(swp_entry_t entry
,
3223 struct mem_cgroup
*from
, struct mem_cgroup
*to
, bool need_fixup
)
3230 * Before starting migration, account PAGE_SIZE to mem_cgroup that the old
3233 int mem_cgroup_prepare_migration(struct page
*page
,
3234 struct page
*newpage
, struct mem_cgroup
**ptr
, gfp_t gfp_mask
)
3236 struct mem_cgroup
*mem
= NULL
;
3237 struct page_cgroup
*pc
;
3238 enum charge_type ctype
;
3243 VM_BUG_ON(PageTransHuge(page
));
3244 if (mem_cgroup_disabled())
3247 pc
= lookup_page_cgroup(page
);
3248 lock_page_cgroup(pc
);
3249 if (PageCgroupUsed(pc
)) {
3250 mem
= pc
->mem_cgroup
;
3253 * At migrating an anonymous page, its mapcount goes down
3254 * to 0 and uncharge() will be called. But, even if it's fully
3255 * unmapped, migration may fail and this page has to be
3256 * charged again. We set MIGRATION flag here and delay uncharge
3257 * until end_migration() is called
3259 * Corner Case Thinking
3261 * When the old page was mapped as Anon and it's unmap-and-freed
3262 * while migration was ongoing.
3263 * If unmap finds the old page, uncharge() of it will be delayed
3264 * until end_migration(). If unmap finds a new page, it's
3265 * uncharged when it make mapcount to be 1->0. If unmap code
3266 * finds swap_migration_entry, the new page will not be mapped
3267 * and end_migration() will find it(mapcount==0).
3270 * When the old page was mapped but migraion fails, the kernel
3271 * remaps it. A charge for it is kept by MIGRATION flag even
3272 * if mapcount goes down to 0. We can do remap successfully
3273 * without charging it again.
3276 * The "old" page is under lock_page() until the end of
3277 * migration, so, the old page itself will not be swapped-out.
3278 * If the new page is swapped out before end_migraton, our
3279 * hook to usual swap-out path will catch the event.
3282 SetPageCgroupMigration(pc
);
3284 unlock_page_cgroup(pc
);
3286 * If the page is not charged at this point,
3293 ret
= __mem_cgroup_try_charge(NULL
, gfp_mask
, 1, ptr
, false);
3294 css_put(&mem
->css
);/* drop extra refcnt */
3295 if (ret
|| *ptr
== NULL
) {
3296 if (PageAnon(page
)) {
3297 lock_page_cgroup(pc
);
3298 ClearPageCgroupMigration(pc
);
3299 unlock_page_cgroup(pc
);
3301 * The old page may be fully unmapped while we kept it.
3303 mem_cgroup_uncharge_page(page
);
3308 * We charge new page before it's used/mapped. So, even if unlock_page()
3309 * is called before end_migration, we can catch all events on this new
3310 * page. In the case new page is migrated but not remapped, new page's
3311 * mapcount will be finally 0 and we call uncharge in end_migration().
3313 pc
= lookup_page_cgroup(newpage
);
3315 ctype
= MEM_CGROUP_CHARGE_TYPE_MAPPED
;
3316 else if (page_is_file_cache(page
))
3317 ctype
= MEM_CGROUP_CHARGE_TYPE_CACHE
;
3319 ctype
= MEM_CGROUP_CHARGE_TYPE_SHMEM
;
3320 __mem_cgroup_commit_charge(mem
, page
, 1, pc
, ctype
);
3324 /* remove redundant charge if migration failed*/
3325 void mem_cgroup_end_migration(struct mem_cgroup
*mem
,
3326 struct page
*oldpage
, struct page
*newpage
, bool migration_ok
)
3328 struct page
*used
, *unused
;
3329 struct page_cgroup
*pc
;
3333 /* blocks rmdir() */
3334 cgroup_exclude_rmdir(&mem
->css
);
3335 if (!migration_ok
) {
3343 * We disallowed uncharge of pages under migration because mapcount
3344 * of the page goes down to zero, temporarly.
3345 * Clear the flag and check the page should be charged.
3347 pc
= lookup_page_cgroup(oldpage
);
3348 lock_page_cgroup(pc
);
3349 ClearPageCgroupMigration(pc
);
3350 unlock_page_cgroup(pc
);
3352 __mem_cgroup_uncharge_common(unused
, MEM_CGROUP_CHARGE_TYPE_FORCE
);
3355 * If a page is a file cache, radix-tree replacement is very atomic
3356 * and we can skip this check. When it was an Anon page, its mapcount
3357 * goes down to 0. But because we added MIGRATION flage, it's not
3358 * uncharged yet. There are several case but page->mapcount check
3359 * and USED bit check in mem_cgroup_uncharge_page() will do enough
3360 * check. (see prepare_charge() also)
3363 mem_cgroup_uncharge_page(used
);
3365 * At migration, we may charge account against cgroup which has no
3367 * So, rmdir()->pre_destroy() can be called while we do this charge.
3368 * In that case, we need to call pre_destroy() again. check it here.
3370 cgroup_release_and_wakeup_rmdir(&mem
->css
);
3374 * A call to try to shrink memory usage on charge failure at shmem's swapin.
3375 * Calling hierarchical_reclaim is not enough because we should update
3376 * last_oom_jiffies to prevent pagefault_out_of_memory from invoking global OOM.
3377 * Moreover considering hierarchy, we should reclaim from the mem_over_limit,
3378 * not from the memcg which this page would be charged to.
3379 * try_charge_swapin does all of these works properly.
3381 int mem_cgroup_shmem_charge_fallback(struct page
*page
,
3382 struct mm_struct
*mm
,
3385 struct mem_cgroup
*mem
;
3388 if (mem_cgroup_disabled())
3391 ret
= mem_cgroup_try_charge_swapin(mm
, page
, gfp_mask
, &mem
);
3393 mem_cgroup_cancel_charge_swapin(mem
); /* it does !mem check */
3398 #ifdef CONFIG_DEBUG_VM
3399 static struct page_cgroup
*lookup_page_cgroup_used(struct page
*page
)
3401 struct page_cgroup
*pc
;
3403 pc
= lookup_page_cgroup(page
);
3404 if (likely(pc
) && PageCgroupUsed(pc
))
3409 bool mem_cgroup_bad_page_check(struct page
*page
)
3411 if (mem_cgroup_disabled())
3414 return lookup_page_cgroup_used(page
) != NULL
;
3417 void mem_cgroup_print_bad_page(struct page
*page
)
3419 struct page_cgroup
*pc
;
3421 pc
= lookup_page_cgroup_used(page
);
3426 printk(KERN_ALERT
"pc:%p pc->flags:%lx pc->mem_cgroup:%p",
3427 pc
, pc
->flags
, pc
->mem_cgroup
);
3429 path
= kmalloc(PATH_MAX
, GFP_KERNEL
);
3432 ret
= cgroup_path(pc
->mem_cgroup
->css
.cgroup
,
3437 printk(KERN_CONT
"(%s)\n",
3438 (ret
< 0) ? "cannot get the path" : path
);
3444 static DEFINE_MUTEX(set_limit_mutex
);
3446 static int mem_cgroup_resize_limit(struct mem_cgroup
*memcg
,
3447 unsigned long long val
)
3450 u64 memswlimit
, memlimit
;
3452 int children
= mem_cgroup_count_children(memcg
);
3453 u64 curusage
, oldusage
;
3457 * For keeping hierarchical_reclaim simple, how long we should retry
3458 * is depends on callers. We set our retry-count to be function
3459 * of # of children which we should visit in this loop.
3461 retry_count
= MEM_CGROUP_RECLAIM_RETRIES
* children
;
3463 oldusage
= res_counter_read_u64(&memcg
->res
, RES_USAGE
);
3466 while (retry_count
) {
3467 if (signal_pending(current
)) {
3472 * Rather than hide all in some function, I do this in
3473 * open coded manner. You see what this really does.
3474 * We have to guarantee mem->res.limit < mem->memsw.limit.
3476 mutex_lock(&set_limit_mutex
);
3477 memswlimit
= res_counter_read_u64(&memcg
->memsw
, RES_LIMIT
);
3478 if (memswlimit
< val
) {
3480 mutex_unlock(&set_limit_mutex
);
3484 memlimit
= res_counter_read_u64(&memcg
->res
, RES_LIMIT
);
3488 ret
= res_counter_set_limit(&memcg
->res
, val
);
3490 if (memswlimit
== val
)
3491 memcg
->memsw_is_minimum
= true;
3493 memcg
->memsw_is_minimum
= false;
3495 mutex_unlock(&set_limit_mutex
);
3500 mem_cgroup_hierarchical_reclaim(memcg
, NULL
, GFP_KERNEL
,
3501 MEM_CGROUP_RECLAIM_SHRINK
,
3503 curusage
= res_counter_read_u64(&memcg
->res
, RES_USAGE
);
3504 /* Usage is reduced ? */
3505 if (curusage
>= oldusage
)
3508 oldusage
= curusage
;
3510 if (!ret
&& enlarge
)
3511 memcg_oom_recover(memcg
);
3516 static int mem_cgroup_resize_memsw_limit(struct mem_cgroup
*memcg
,
3517 unsigned long long val
)
3520 u64 memlimit
, memswlimit
, oldusage
, curusage
;
3521 int children
= mem_cgroup_count_children(memcg
);
3525 /* see mem_cgroup_resize_res_limit */
3526 retry_count
= children
* MEM_CGROUP_RECLAIM_RETRIES
;
3527 oldusage
= res_counter_read_u64(&memcg
->memsw
, RES_USAGE
);
3528 while (retry_count
) {
3529 if (signal_pending(current
)) {
3534 * Rather than hide all in some function, I do this in
3535 * open coded manner. You see what this really does.
3536 * We have to guarantee mem->res.limit < mem->memsw.limit.
3538 mutex_lock(&set_limit_mutex
);
3539 memlimit
= res_counter_read_u64(&memcg
->res
, RES_LIMIT
);
3540 if (memlimit
> val
) {
3542 mutex_unlock(&set_limit_mutex
);
3545 memswlimit
= res_counter_read_u64(&memcg
->memsw
, RES_LIMIT
);
3546 if (memswlimit
< val
)
3548 ret
= res_counter_set_limit(&memcg
->memsw
, val
);
3550 if (memlimit
== val
)
3551 memcg
->memsw_is_minimum
= true;
3553 memcg
->memsw_is_minimum
= false;
3555 mutex_unlock(&set_limit_mutex
);
3560 mem_cgroup_hierarchical_reclaim(memcg
, NULL
, GFP_KERNEL
,
3561 MEM_CGROUP_RECLAIM_NOSWAP
|
3562 MEM_CGROUP_RECLAIM_SHRINK
,
3564 curusage
= res_counter_read_u64(&memcg
->memsw
, RES_USAGE
);
3565 /* Usage is reduced ? */
3566 if (curusage
>= oldusage
)
3569 oldusage
= curusage
;
3571 if (!ret
&& enlarge
)
3572 memcg_oom_recover(memcg
);
3576 unsigned long mem_cgroup_soft_limit_reclaim(struct zone
*zone
, int order
,
3578 unsigned long *total_scanned
)
3580 unsigned long nr_reclaimed
= 0;
3581 struct mem_cgroup_per_zone
*mz
, *next_mz
= NULL
;
3582 unsigned long reclaimed
;
3584 struct mem_cgroup_tree_per_zone
*mctz
;
3585 unsigned long long excess
;
3586 unsigned long nr_scanned
;
3591 mctz
= soft_limit_tree_node_zone(zone_to_nid(zone
), zone_idx(zone
));
3593 * This loop can run a while, specially if mem_cgroup's continuously
3594 * keep exceeding their soft limit and putting the system under
3601 mz
= mem_cgroup_largest_soft_limit_node(mctz
);
3606 reclaimed
= mem_cgroup_hierarchical_reclaim(mz
->mem
, zone
,
3608 MEM_CGROUP_RECLAIM_SOFT
,
3610 nr_reclaimed
+= reclaimed
;
3611 *total_scanned
+= nr_scanned
;
3612 spin_lock(&mctz
->lock
);
3615 * If we failed to reclaim anything from this memory cgroup
3616 * it is time to move on to the next cgroup
3622 * Loop until we find yet another one.
3624 * By the time we get the soft_limit lock
3625 * again, someone might have aded the
3626 * group back on the RB tree. Iterate to
3627 * make sure we get a different mem.
3628 * mem_cgroup_largest_soft_limit_node returns
3629 * NULL if no other cgroup is present on
3633 __mem_cgroup_largest_soft_limit_node(mctz
);
3635 css_put(&next_mz
->mem
->css
);
3636 else /* next_mz == NULL or other memcg */
3640 __mem_cgroup_remove_exceeded(mz
->mem
, mz
, mctz
);
3641 excess
= res_counter_soft_limit_excess(&mz
->mem
->res
);
3643 * One school of thought says that we should not add
3644 * back the node to the tree if reclaim returns 0.
3645 * But our reclaim could return 0, simply because due
3646 * to priority we are exposing a smaller subset of
3647 * memory to reclaim from. Consider this as a longer
3650 /* If excess == 0, no tree ops */
3651 __mem_cgroup_insert_exceeded(mz
->mem
, mz
, mctz
, excess
);
3652 spin_unlock(&mctz
->lock
);
3653 css_put(&mz
->mem
->css
);
3656 * Could not reclaim anything and there are no more
3657 * mem cgroups to try or we seem to be looping without
3658 * reclaiming anything.
3660 if (!nr_reclaimed
&&
3662 loop
> MEM_CGROUP_MAX_SOFT_LIMIT_RECLAIM_LOOPS
))
3664 } while (!nr_reclaimed
);
3666 css_put(&next_mz
->mem
->css
);
3667 return nr_reclaimed
;
3671 * This routine traverse page_cgroup in given list and drop them all.
3672 * *And* this routine doesn't reclaim page itself, just removes page_cgroup.
3674 static int mem_cgroup_force_empty_list(struct mem_cgroup
*mem
,
3675 int node
, int zid
, enum lru_list lru
)
3678 struct mem_cgroup_per_zone
*mz
;
3679 struct page_cgroup
*pc
, *busy
;
3680 unsigned long flags
, loop
;
3681 struct list_head
*list
;
3684 zone
= &NODE_DATA(node
)->node_zones
[zid
];
3685 mz
= mem_cgroup_zoneinfo(mem
, node
, zid
);
3686 list
= &mz
->lists
[lru
];
3688 loop
= MEM_CGROUP_ZSTAT(mz
, lru
);
3689 /* give some margin against EBUSY etc...*/
3696 spin_lock_irqsave(&zone
->lru_lock
, flags
);
3697 if (list_empty(list
)) {
3698 spin_unlock_irqrestore(&zone
->lru_lock
, flags
);
3701 pc
= list_entry(list
->prev
, struct page_cgroup
, lru
);
3703 list_move(&pc
->lru
, list
);
3705 spin_unlock_irqrestore(&zone
->lru_lock
, flags
);
3708 spin_unlock_irqrestore(&zone
->lru_lock
, flags
);
3710 page
= lookup_cgroup_page(pc
);
3712 ret
= mem_cgroup_move_parent(page
, pc
, mem
, GFP_KERNEL
);
3716 if (ret
== -EBUSY
|| ret
== -EINVAL
) {
3717 /* found lock contention or "pc" is obsolete. */
3724 if (!ret
&& !list_empty(list
))
3730 * make mem_cgroup's charge to be 0 if there is no task.
3731 * This enables deleting this mem_cgroup.
3733 static int mem_cgroup_force_empty(struct mem_cgroup
*mem
, bool free_all
)
3736 int node
, zid
, shrink
;
3737 int nr_retries
= MEM_CGROUP_RECLAIM_RETRIES
;
3738 struct cgroup
*cgrp
= mem
->css
.cgroup
;
3743 /* should free all ? */
3749 if (cgroup_task_count(cgrp
) || !list_empty(&cgrp
->children
))
3752 if (signal_pending(current
))
3754 /* This is for making all *used* pages to be on LRU. */
3755 lru_add_drain_all();
3756 drain_all_stock_sync();
3758 mem_cgroup_start_move(mem
);
3759 for_each_node_state(node
, N_HIGH_MEMORY
) {
3760 for (zid
= 0; !ret
&& zid
< MAX_NR_ZONES
; zid
++) {
3763 ret
= mem_cgroup_force_empty_list(mem
,
3772 mem_cgroup_end_move(mem
);
3773 memcg_oom_recover(mem
);
3774 /* it seems parent cgroup doesn't have enough mem */
3778 /* "ret" should also be checked to ensure all lists are empty. */
3779 } while (mem
->res
.usage
> 0 || ret
);
3785 /* returns EBUSY if there is a task or if we come here twice. */
3786 if (cgroup_task_count(cgrp
) || !list_empty(&cgrp
->children
) || shrink
) {
3790 /* we call try-to-free pages for make this cgroup empty */
3791 lru_add_drain_all();
3792 /* try to free all pages in this cgroup */
3794 while (nr_retries
&& mem
->res
.usage
> 0) {
3797 if (signal_pending(current
)) {
3801 progress
= try_to_free_mem_cgroup_pages(mem
, GFP_KERNEL
,
3805 /* maybe some writeback is necessary */
3806 congestion_wait(BLK_RW_ASYNC
, HZ
/10);
3811 /* try move_account...there may be some *locked* pages. */
3815 int mem_cgroup_force_empty_write(struct cgroup
*cont
, unsigned int event
)
3817 return mem_cgroup_force_empty(mem_cgroup_from_cont(cont
), true);
3821 static u64
mem_cgroup_hierarchy_read(struct cgroup
*cont
, struct cftype
*cft
)
3823 return mem_cgroup_from_cont(cont
)->use_hierarchy
;
3826 static int mem_cgroup_hierarchy_write(struct cgroup
*cont
, struct cftype
*cft
,
3830 struct mem_cgroup
*mem
= mem_cgroup_from_cont(cont
);
3831 struct cgroup
*parent
= cont
->parent
;
3832 struct mem_cgroup
*parent_mem
= NULL
;
3835 parent_mem
= mem_cgroup_from_cont(parent
);
3839 * If parent's use_hierarchy is set, we can't make any modifications
3840 * in the child subtrees. If it is unset, then the change can
3841 * occur, provided the current cgroup has no children.
3843 * For the root cgroup, parent_mem is NULL, we allow value to be
3844 * set if there are no children.
3846 if ((!parent_mem
|| !parent_mem
->use_hierarchy
) &&
3847 (val
== 1 || val
== 0)) {
3848 if (list_empty(&cont
->children
))
3849 mem
->use_hierarchy
= val
;
3860 static unsigned long mem_cgroup_recursive_stat(struct mem_cgroup
*mem
,
3861 enum mem_cgroup_stat_index idx
)
3863 struct mem_cgroup
*iter
;
3866 /* Per-cpu values can be negative, use a signed accumulator */
3867 for_each_mem_cgroup_tree(iter
, mem
)
3868 val
+= mem_cgroup_read_stat(iter
, idx
);
3870 if (val
< 0) /* race ? */
3875 static inline u64
mem_cgroup_usage(struct mem_cgroup
*mem
, bool swap
)
3879 if (!mem_cgroup_is_root(mem
)) {
3881 return res_counter_read_u64(&mem
->res
, RES_USAGE
);
3883 return res_counter_read_u64(&mem
->memsw
, RES_USAGE
);
3886 val
= mem_cgroup_recursive_stat(mem
, MEM_CGROUP_STAT_CACHE
);
3887 val
+= mem_cgroup_recursive_stat(mem
, MEM_CGROUP_STAT_RSS
);
3890 val
+= mem_cgroup_recursive_stat(mem
, MEM_CGROUP_STAT_SWAPOUT
);
3892 return val
<< PAGE_SHIFT
;
3895 static u64
mem_cgroup_read(struct cgroup
*cont
, struct cftype
*cft
)
3897 struct mem_cgroup
*mem
= mem_cgroup_from_cont(cont
);
3901 type
= MEMFILE_TYPE(cft
->private);
3902 name
= MEMFILE_ATTR(cft
->private);
3905 if (name
== RES_USAGE
)
3906 val
= mem_cgroup_usage(mem
, false);
3908 val
= res_counter_read_u64(&mem
->res
, name
);
3911 if (name
== RES_USAGE
)
3912 val
= mem_cgroup_usage(mem
, true);
3914 val
= res_counter_read_u64(&mem
->memsw
, name
);
3923 * The user of this function is...
3926 static int mem_cgroup_write(struct cgroup
*cont
, struct cftype
*cft
,
3929 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cont
);
3931 unsigned long long val
;
3934 type
= MEMFILE_TYPE(cft
->private);
3935 name
= MEMFILE_ATTR(cft
->private);
3938 if (mem_cgroup_is_root(memcg
)) { /* Can't set limit on root */
3942 /* This function does all necessary parse...reuse it */
3943 ret
= res_counter_memparse_write_strategy(buffer
, &val
);
3947 ret
= mem_cgroup_resize_limit(memcg
, val
);
3949 ret
= mem_cgroup_resize_memsw_limit(memcg
, val
);
3951 case RES_SOFT_LIMIT
:
3952 ret
= res_counter_memparse_write_strategy(buffer
, &val
);
3956 * For memsw, soft limits are hard to implement in terms
3957 * of semantics, for now, we support soft limits for
3958 * control without swap
3961 ret
= res_counter_set_soft_limit(&memcg
->res
, val
);
3966 ret
= -EINVAL
; /* should be BUG() ? */
3972 static void memcg_get_hierarchical_limit(struct mem_cgroup
*memcg
,
3973 unsigned long long *mem_limit
, unsigned long long *memsw_limit
)
3975 struct cgroup
*cgroup
;
3976 unsigned long long min_limit
, min_memsw_limit
, tmp
;
3978 min_limit
= res_counter_read_u64(&memcg
->res
, RES_LIMIT
);
3979 min_memsw_limit
= res_counter_read_u64(&memcg
->memsw
, RES_LIMIT
);
3980 cgroup
= memcg
->css
.cgroup
;
3981 if (!memcg
->use_hierarchy
)
3984 while (cgroup
->parent
) {
3985 cgroup
= cgroup
->parent
;
3986 memcg
= mem_cgroup_from_cont(cgroup
);
3987 if (!memcg
->use_hierarchy
)
3989 tmp
= res_counter_read_u64(&memcg
->res
, RES_LIMIT
);
3990 min_limit
= min(min_limit
, tmp
);
3991 tmp
= res_counter_read_u64(&memcg
->memsw
, RES_LIMIT
);
3992 min_memsw_limit
= min(min_memsw_limit
, tmp
);
3995 *mem_limit
= min_limit
;
3996 *memsw_limit
= min_memsw_limit
;
4000 static int mem_cgroup_reset(struct cgroup
*cont
, unsigned int event
)
4002 struct mem_cgroup
*mem
;
4005 mem
= mem_cgroup_from_cont(cont
);
4006 type
= MEMFILE_TYPE(event
);
4007 name
= MEMFILE_ATTR(event
);
4011 res_counter_reset_max(&mem
->res
);
4013 res_counter_reset_max(&mem
->memsw
);
4017 res_counter_reset_failcnt(&mem
->res
);
4019 res_counter_reset_failcnt(&mem
->memsw
);
4026 static u64
mem_cgroup_move_charge_read(struct cgroup
*cgrp
,
4029 return mem_cgroup_from_cont(cgrp
)->move_charge_at_immigrate
;
4033 static int mem_cgroup_move_charge_write(struct cgroup
*cgrp
,
4034 struct cftype
*cft
, u64 val
)
4036 struct mem_cgroup
*mem
= mem_cgroup_from_cont(cgrp
);
4038 if (val
>= (1 << NR_MOVE_TYPE
))
4041 * We check this value several times in both in can_attach() and
4042 * attach(), so we need cgroup lock to prevent this value from being
4046 mem
->move_charge_at_immigrate
= val
;
4052 static int mem_cgroup_move_charge_write(struct cgroup
*cgrp
,
4053 struct cftype
*cft
, u64 val
)
4060 /* For read statistics */
4078 struct mcs_total_stat
{
4079 s64 stat
[NR_MCS_STAT
];
4085 } memcg_stat_strings
[NR_MCS_STAT
] = {
4086 {"cache", "total_cache"},
4087 {"rss", "total_rss"},
4088 {"mapped_file", "total_mapped_file"},
4089 {"pgpgin", "total_pgpgin"},
4090 {"pgpgout", "total_pgpgout"},
4091 {"swap", "total_swap"},
4092 {"pgfault", "total_pgfault"},
4093 {"pgmajfault", "total_pgmajfault"},
4094 {"inactive_anon", "total_inactive_anon"},
4095 {"active_anon", "total_active_anon"},
4096 {"inactive_file", "total_inactive_file"},
4097 {"active_file", "total_active_file"},
4098 {"unevictable", "total_unevictable"}
4103 mem_cgroup_get_local_stat(struct mem_cgroup
*mem
, struct mcs_total_stat
*s
)
4108 val
= mem_cgroup_read_stat(mem
, MEM_CGROUP_STAT_CACHE
);
4109 s
->stat
[MCS_CACHE
] += val
* PAGE_SIZE
;
4110 val
= mem_cgroup_read_stat(mem
, MEM_CGROUP_STAT_RSS
);
4111 s
->stat
[MCS_RSS
] += val
* PAGE_SIZE
;
4112 val
= mem_cgroup_read_stat(mem
, MEM_CGROUP_STAT_FILE_MAPPED
);
4113 s
->stat
[MCS_FILE_MAPPED
] += val
* PAGE_SIZE
;
4114 val
= mem_cgroup_read_events(mem
, MEM_CGROUP_EVENTS_PGPGIN
);
4115 s
->stat
[MCS_PGPGIN
] += val
;
4116 val
= mem_cgroup_read_events(mem
, MEM_CGROUP_EVENTS_PGPGOUT
);
4117 s
->stat
[MCS_PGPGOUT
] += val
;
4118 if (do_swap_account
) {
4119 val
= mem_cgroup_read_stat(mem
, MEM_CGROUP_STAT_SWAPOUT
);
4120 s
->stat
[MCS_SWAP
] += val
* PAGE_SIZE
;
4122 val
= mem_cgroup_read_events(mem
, MEM_CGROUP_EVENTS_PGFAULT
);
4123 s
->stat
[MCS_PGFAULT
] += val
;
4124 val
= mem_cgroup_read_events(mem
, MEM_CGROUP_EVENTS_PGMAJFAULT
);
4125 s
->stat
[MCS_PGMAJFAULT
] += val
;
4128 val
= mem_cgroup_nr_lru_pages(mem
, BIT(LRU_INACTIVE_ANON
));
4129 s
->stat
[MCS_INACTIVE_ANON
] += val
* PAGE_SIZE
;
4130 val
= mem_cgroup_nr_lru_pages(mem
, BIT(LRU_ACTIVE_ANON
));
4131 s
->stat
[MCS_ACTIVE_ANON
] += val
* PAGE_SIZE
;
4132 val
= mem_cgroup_nr_lru_pages(mem
, BIT(LRU_INACTIVE_FILE
));
4133 s
->stat
[MCS_INACTIVE_FILE
] += val
* PAGE_SIZE
;
4134 val
= mem_cgroup_nr_lru_pages(mem
, BIT(LRU_ACTIVE_FILE
));
4135 s
->stat
[MCS_ACTIVE_FILE
] += val
* PAGE_SIZE
;
4136 val
= mem_cgroup_nr_lru_pages(mem
, BIT(LRU_UNEVICTABLE
));
4137 s
->stat
[MCS_UNEVICTABLE
] += val
* PAGE_SIZE
;
4141 mem_cgroup_get_total_stat(struct mem_cgroup
*mem
, struct mcs_total_stat
*s
)
4143 struct mem_cgroup
*iter
;
4145 for_each_mem_cgroup_tree(iter
, mem
)
4146 mem_cgroup_get_local_stat(iter
, s
);
4150 static int mem_control_numa_stat_show(struct seq_file
*m
, void *arg
)
4153 unsigned long total_nr
, file_nr
, anon_nr
, unevictable_nr
;
4154 unsigned long node_nr
;
4155 struct cgroup
*cont
= m
->private;
4156 struct mem_cgroup
*mem_cont
= mem_cgroup_from_cont(cont
);
4158 total_nr
= mem_cgroup_nr_lru_pages(mem_cont
, LRU_ALL
);
4159 seq_printf(m
, "total=%lu", total_nr
);
4160 for_each_node_state(nid
, N_HIGH_MEMORY
) {
4161 node_nr
= mem_cgroup_node_nr_lru_pages(mem_cont
, nid
, LRU_ALL
);
4162 seq_printf(m
, " N%d=%lu", nid
, node_nr
);
4166 file_nr
= mem_cgroup_nr_lru_pages(mem_cont
, LRU_ALL_FILE
);
4167 seq_printf(m
, "file=%lu", file_nr
);
4168 for_each_node_state(nid
, N_HIGH_MEMORY
) {
4169 node_nr
= mem_cgroup_node_nr_lru_pages(mem_cont
, nid
,
4171 seq_printf(m
, " N%d=%lu", nid
, node_nr
);
4175 anon_nr
= mem_cgroup_nr_lru_pages(mem_cont
, LRU_ALL_ANON
);
4176 seq_printf(m
, "anon=%lu", anon_nr
);
4177 for_each_node_state(nid
, N_HIGH_MEMORY
) {
4178 node_nr
= mem_cgroup_node_nr_lru_pages(mem_cont
, nid
,
4180 seq_printf(m
, " N%d=%lu", nid
, node_nr
);
4184 unevictable_nr
= mem_cgroup_nr_lru_pages(mem_cont
, BIT(LRU_UNEVICTABLE
));
4185 seq_printf(m
, "unevictable=%lu", unevictable_nr
);
4186 for_each_node_state(nid
, N_HIGH_MEMORY
) {
4187 node_nr
= mem_cgroup_node_nr_lru_pages(mem_cont
, nid
,
4188 BIT(LRU_UNEVICTABLE
));
4189 seq_printf(m
, " N%d=%lu", nid
, node_nr
);
4194 #endif /* CONFIG_NUMA */
4196 static int mem_control_stat_show(struct cgroup
*cont
, struct cftype
*cft
,
4197 struct cgroup_map_cb
*cb
)
4199 struct mem_cgroup
*mem_cont
= mem_cgroup_from_cont(cont
);
4200 struct mcs_total_stat mystat
;
4203 memset(&mystat
, 0, sizeof(mystat
));
4204 mem_cgroup_get_local_stat(mem_cont
, &mystat
);
4207 for (i
= 0; i
< NR_MCS_STAT
; i
++) {
4208 if (i
== MCS_SWAP
&& !do_swap_account
)
4210 cb
->fill(cb
, memcg_stat_strings
[i
].local_name
, mystat
.stat
[i
]);
4213 /* Hierarchical information */
4215 unsigned long long limit
, memsw_limit
;
4216 memcg_get_hierarchical_limit(mem_cont
, &limit
, &memsw_limit
);
4217 cb
->fill(cb
, "hierarchical_memory_limit", limit
);
4218 if (do_swap_account
)
4219 cb
->fill(cb
, "hierarchical_memsw_limit", memsw_limit
);
4222 memset(&mystat
, 0, sizeof(mystat
));
4223 mem_cgroup_get_total_stat(mem_cont
, &mystat
);
4224 for (i
= 0; i
< NR_MCS_STAT
; i
++) {
4225 if (i
== MCS_SWAP
&& !do_swap_account
)
4227 cb
->fill(cb
, memcg_stat_strings
[i
].total_name
, mystat
.stat
[i
]);
4230 #ifdef CONFIG_DEBUG_VM
4231 cb
->fill(cb
, "inactive_ratio", calc_inactive_ratio(mem_cont
, NULL
));
4235 struct mem_cgroup_per_zone
*mz
;
4236 unsigned long recent_rotated
[2] = {0, 0};
4237 unsigned long recent_scanned
[2] = {0, 0};
4239 for_each_online_node(nid
)
4240 for (zid
= 0; zid
< MAX_NR_ZONES
; zid
++) {
4241 mz
= mem_cgroup_zoneinfo(mem_cont
, nid
, zid
);
4243 recent_rotated
[0] +=
4244 mz
->reclaim_stat
.recent_rotated
[0];
4245 recent_rotated
[1] +=
4246 mz
->reclaim_stat
.recent_rotated
[1];
4247 recent_scanned
[0] +=
4248 mz
->reclaim_stat
.recent_scanned
[0];
4249 recent_scanned
[1] +=
4250 mz
->reclaim_stat
.recent_scanned
[1];
4252 cb
->fill(cb
, "recent_rotated_anon", recent_rotated
[0]);
4253 cb
->fill(cb
, "recent_rotated_file", recent_rotated
[1]);
4254 cb
->fill(cb
, "recent_scanned_anon", recent_scanned
[0]);
4255 cb
->fill(cb
, "recent_scanned_file", recent_scanned
[1]);
4262 static u64
mem_cgroup_swappiness_read(struct cgroup
*cgrp
, struct cftype
*cft
)
4264 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cgrp
);
4266 return mem_cgroup_swappiness(memcg
);
4269 static int mem_cgroup_swappiness_write(struct cgroup
*cgrp
, struct cftype
*cft
,
4272 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cgrp
);
4273 struct mem_cgroup
*parent
;
4278 if (cgrp
->parent
== NULL
)
4281 parent
= mem_cgroup_from_cont(cgrp
->parent
);
4285 /* If under hierarchy, only empty-root can set this value */
4286 if ((parent
->use_hierarchy
) ||
4287 (memcg
->use_hierarchy
&& !list_empty(&cgrp
->children
))) {
4292 memcg
->swappiness
= val
;
4299 static void __mem_cgroup_threshold(struct mem_cgroup
*memcg
, bool swap
)
4301 struct mem_cgroup_threshold_ary
*t
;
4307 t
= rcu_dereference(memcg
->thresholds
.primary
);
4309 t
= rcu_dereference(memcg
->memsw_thresholds
.primary
);
4314 usage
= mem_cgroup_usage(memcg
, swap
);
4317 * current_threshold points to threshold just below usage.
4318 * If it's not true, a threshold was crossed after last
4319 * call of __mem_cgroup_threshold().
4321 i
= t
->current_threshold
;
4324 * Iterate backward over array of thresholds starting from
4325 * current_threshold and check if a threshold is crossed.
4326 * If none of thresholds below usage is crossed, we read
4327 * only one element of the array here.
4329 for (; i
>= 0 && unlikely(t
->entries
[i
].threshold
> usage
); i
--)
4330 eventfd_signal(t
->entries
[i
].eventfd
, 1);
4332 /* i = current_threshold + 1 */
4336 * Iterate forward over array of thresholds starting from
4337 * current_threshold+1 and check if a threshold is crossed.
4338 * If none of thresholds above usage is crossed, we read
4339 * only one element of the array here.
4341 for (; i
< t
->size
&& unlikely(t
->entries
[i
].threshold
<= usage
); i
++)
4342 eventfd_signal(t
->entries
[i
].eventfd
, 1);
4344 /* Update current_threshold */
4345 t
->current_threshold
= i
- 1;
4350 static void mem_cgroup_threshold(struct mem_cgroup
*memcg
)
4353 __mem_cgroup_threshold(memcg
, false);
4354 if (do_swap_account
)
4355 __mem_cgroup_threshold(memcg
, true);
4357 memcg
= parent_mem_cgroup(memcg
);
4361 static int compare_thresholds(const void *a
, const void *b
)
4363 const struct mem_cgroup_threshold
*_a
= a
;
4364 const struct mem_cgroup_threshold
*_b
= b
;
4366 return _a
->threshold
- _b
->threshold
;
4369 static int mem_cgroup_oom_notify_cb(struct mem_cgroup
*mem
)
4371 struct mem_cgroup_eventfd_list
*ev
;
4373 list_for_each_entry(ev
, &mem
->oom_notify
, list
)
4374 eventfd_signal(ev
->eventfd
, 1);
4378 static void mem_cgroup_oom_notify(struct mem_cgroup
*mem
)
4380 struct mem_cgroup
*iter
;
4382 for_each_mem_cgroup_tree(iter
, mem
)
4383 mem_cgroup_oom_notify_cb(iter
);
4386 static int mem_cgroup_usage_register_event(struct cgroup
*cgrp
,
4387 struct cftype
*cft
, struct eventfd_ctx
*eventfd
, const char *args
)
4389 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cgrp
);
4390 struct mem_cgroup_thresholds
*thresholds
;
4391 struct mem_cgroup_threshold_ary
*new;
4392 int type
= MEMFILE_TYPE(cft
->private);
4393 u64 threshold
, usage
;
4396 ret
= res_counter_memparse_write_strategy(args
, &threshold
);
4400 mutex_lock(&memcg
->thresholds_lock
);
4403 thresholds
= &memcg
->thresholds
;
4404 else if (type
== _MEMSWAP
)
4405 thresholds
= &memcg
->memsw_thresholds
;
4409 usage
= mem_cgroup_usage(memcg
, type
== _MEMSWAP
);
4411 /* Check if a threshold crossed before adding a new one */
4412 if (thresholds
->primary
)
4413 __mem_cgroup_threshold(memcg
, type
== _MEMSWAP
);
4415 size
= thresholds
->primary
? thresholds
->primary
->size
+ 1 : 1;
4417 /* Allocate memory for new array of thresholds */
4418 new = kmalloc(sizeof(*new) + size
* sizeof(struct mem_cgroup_threshold
),
4426 /* Copy thresholds (if any) to new array */
4427 if (thresholds
->primary
) {
4428 memcpy(new->entries
, thresholds
->primary
->entries
, (size
- 1) *
4429 sizeof(struct mem_cgroup_threshold
));
4432 /* Add new threshold */
4433 new->entries
[size
- 1].eventfd
= eventfd
;
4434 new->entries
[size
- 1].threshold
= threshold
;
4436 /* Sort thresholds. Registering of new threshold isn't time-critical */
4437 sort(new->entries
, size
, sizeof(struct mem_cgroup_threshold
),
4438 compare_thresholds
, NULL
);
4440 /* Find current threshold */
4441 new->current_threshold
= -1;
4442 for (i
= 0; i
< size
; i
++) {
4443 if (new->entries
[i
].threshold
< usage
) {
4445 * new->current_threshold will not be used until
4446 * rcu_assign_pointer(), so it's safe to increment
4449 ++new->current_threshold
;
4453 /* Free old spare buffer and save old primary buffer as spare */
4454 kfree(thresholds
->spare
);
4455 thresholds
->spare
= thresholds
->primary
;
4457 rcu_assign_pointer(thresholds
->primary
, new);
4459 /* To be sure that nobody uses thresholds */
4463 mutex_unlock(&memcg
->thresholds_lock
);
4468 static void mem_cgroup_usage_unregister_event(struct cgroup
*cgrp
,
4469 struct cftype
*cft
, struct eventfd_ctx
*eventfd
)
4471 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cgrp
);
4472 struct mem_cgroup_thresholds
*thresholds
;
4473 struct mem_cgroup_threshold_ary
*new;
4474 int type
= MEMFILE_TYPE(cft
->private);
4478 mutex_lock(&memcg
->thresholds_lock
);
4480 thresholds
= &memcg
->thresholds
;
4481 else if (type
== _MEMSWAP
)
4482 thresholds
= &memcg
->memsw_thresholds
;
4487 * Something went wrong if we trying to unregister a threshold
4488 * if we don't have thresholds
4490 BUG_ON(!thresholds
);
4492 usage
= mem_cgroup_usage(memcg
, type
== _MEMSWAP
);
4494 /* Check if a threshold crossed before removing */
4495 __mem_cgroup_threshold(memcg
, type
== _MEMSWAP
);
4497 /* Calculate new number of threshold */
4499 for (i
= 0; i
< thresholds
->primary
->size
; i
++) {
4500 if (thresholds
->primary
->entries
[i
].eventfd
!= eventfd
)
4504 new = thresholds
->spare
;
4506 /* Set thresholds array to NULL if we don't have thresholds */
4515 /* Copy thresholds and find current threshold */
4516 new->current_threshold
= -1;
4517 for (i
= 0, j
= 0; i
< thresholds
->primary
->size
; i
++) {
4518 if (thresholds
->primary
->entries
[i
].eventfd
== eventfd
)
4521 new->entries
[j
] = thresholds
->primary
->entries
[i
];
4522 if (new->entries
[j
].threshold
< usage
) {
4524 * new->current_threshold will not be used
4525 * until rcu_assign_pointer(), so it's safe to increment
4528 ++new->current_threshold
;
4534 /* Swap primary and spare array */
4535 thresholds
->spare
= thresholds
->primary
;
4536 rcu_assign_pointer(thresholds
->primary
, new);
4538 /* To be sure that nobody uses thresholds */
4541 mutex_unlock(&memcg
->thresholds_lock
);
4544 static int mem_cgroup_oom_register_event(struct cgroup
*cgrp
,
4545 struct cftype
*cft
, struct eventfd_ctx
*eventfd
, const char *args
)
4547 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cgrp
);
4548 struct mem_cgroup_eventfd_list
*event
;
4549 int type
= MEMFILE_TYPE(cft
->private);
4551 BUG_ON(type
!= _OOM_TYPE
);
4552 event
= kmalloc(sizeof(*event
), GFP_KERNEL
);
4556 spin_lock(&memcg_oom_lock
);
4558 event
->eventfd
= eventfd
;
4559 list_add(&event
->list
, &memcg
->oom_notify
);
4561 /* already in OOM ? */
4562 if (atomic_read(&memcg
->under_oom
))
4563 eventfd_signal(eventfd
, 1);
4564 spin_unlock(&memcg_oom_lock
);
4569 static void mem_cgroup_oom_unregister_event(struct cgroup
*cgrp
,
4570 struct cftype
*cft
, struct eventfd_ctx
*eventfd
)
4572 struct mem_cgroup
*mem
= mem_cgroup_from_cont(cgrp
);
4573 struct mem_cgroup_eventfd_list
*ev
, *tmp
;
4574 int type
= MEMFILE_TYPE(cft
->private);
4576 BUG_ON(type
!= _OOM_TYPE
);
4578 spin_lock(&memcg_oom_lock
);
4580 list_for_each_entry_safe(ev
, tmp
, &mem
->oom_notify
, list
) {
4581 if (ev
->eventfd
== eventfd
) {
4582 list_del(&ev
->list
);
4587 spin_unlock(&memcg_oom_lock
);
4590 static int mem_cgroup_oom_control_read(struct cgroup
*cgrp
,
4591 struct cftype
*cft
, struct cgroup_map_cb
*cb
)
4593 struct mem_cgroup
*mem
= mem_cgroup_from_cont(cgrp
);
4595 cb
->fill(cb
, "oom_kill_disable", mem
->oom_kill_disable
);
4597 if (atomic_read(&mem
->under_oom
))
4598 cb
->fill(cb
, "under_oom", 1);
4600 cb
->fill(cb
, "under_oom", 0);
4604 static int mem_cgroup_oom_control_write(struct cgroup
*cgrp
,
4605 struct cftype
*cft
, u64 val
)
4607 struct mem_cgroup
*mem
= mem_cgroup_from_cont(cgrp
);
4608 struct mem_cgroup
*parent
;
4610 /* cannot set to root cgroup and only 0 and 1 are allowed */
4611 if (!cgrp
->parent
|| !((val
== 0) || (val
== 1)))
4614 parent
= mem_cgroup_from_cont(cgrp
->parent
);
4617 /* oom-kill-disable is a flag for subhierarchy. */
4618 if ((parent
->use_hierarchy
) ||
4619 (mem
->use_hierarchy
&& !list_empty(&cgrp
->children
))) {
4623 mem
->oom_kill_disable
= val
;
4625 memcg_oom_recover(mem
);
4631 static const struct file_operations mem_control_numa_stat_file_operations
= {
4633 .llseek
= seq_lseek
,
4634 .release
= single_release
,
4637 static int mem_control_numa_stat_open(struct inode
*unused
, struct file
*file
)
4639 struct cgroup
*cont
= file
->f_dentry
->d_parent
->d_fsdata
;
4641 file
->f_op
= &mem_control_numa_stat_file_operations
;
4642 return single_open(file
, mem_control_numa_stat_show
, cont
);
4644 #endif /* CONFIG_NUMA */
4646 static struct cftype mem_cgroup_files
[] = {
4648 .name
= "usage_in_bytes",
4649 .private = MEMFILE_PRIVATE(_MEM
, RES_USAGE
),
4650 .read_u64
= mem_cgroup_read
,
4651 .register_event
= mem_cgroup_usage_register_event
,
4652 .unregister_event
= mem_cgroup_usage_unregister_event
,
4655 .name
= "max_usage_in_bytes",
4656 .private = MEMFILE_PRIVATE(_MEM
, RES_MAX_USAGE
),
4657 .trigger
= mem_cgroup_reset
,
4658 .read_u64
= mem_cgroup_read
,
4661 .name
= "limit_in_bytes",
4662 .private = MEMFILE_PRIVATE(_MEM
, RES_LIMIT
),
4663 .write_string
= mem_cgroup_write
,
4664 .read_u64
= mem_cgroup_read
,
4667 .name
= "soft_limit_in_bytes",
4668 .private = MEMFILE_PRIVATE(_MEM
, RES_SOFT_LIMIT
),
4669 .write_string
= mem_cgroup_write
,
4670 .read_u64
= mem_cgroup_read
,
4674 .private = MEMFILE_PRIVATE(_MEM
, RES_FAILCNT
),
4675 .trigger
= mem_cgroup_reset
,
4676 .read_u64
= mem_cgroup_read
,
4680 .read_map
= mem_control_stat_show
,
4683 .name
= "force_empty",
4684 .trigger
= mem_cgroup_force_empty_write
,
4687 .name
= "use_hierarchy",
4688 .write_u64
= mem_cgroup_hierarchy_write
,
4689 .read_u64
= mem_cgroup_hierarchy_read
,
4692 .name
= "swappiness",
4693 .read_u64
= mem_cgroup_swappiness_read
,
4694 .write_u64
= mem_cgroup_swappiness_write
,
4697 .name
= "move_charge_at_immigrate",
4698 .read_u64
= mem_cgroup_move_charge_read
,
4699 .write_u64
= mem_cgroup_move_charge_write
,
4702 .name
= "oom_control",
4703 .read_map
= mem_cgroup_oom_control_read
,
4704 .write_u64
= mem_cgroup_oom_control_write
,
4705 .register_event
= mem_cgroup_oom_register_event
,
4706 .unregister_event
= mem_cgroup_oom_unregister_event
,
4707 .private = MEMFILE_PRIVATE(_OOM_TYPE
, OOM_CONTROL
),
4711 .name
= "numa_stat",
4712 .open
= mem_control_numa_stat_open
,
4718 #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP
4719 static struct cftype memsw_cgroup_files
[] = {
4721 .name
= "memsw.usage_in_bytes",
4722 .private = MEMFILE_PRIVATE(_MEMSWAP
, RES_USAGE
),
4723 .read_u64
= mem_cgroup_read
,
4724 .register_event
= mem_cgroup_usage_register_event
,
4725 .unregister_event
= mem_cgroup_usage_unregister_event
,
4728 .name
= "memsw.max_usage_in_bytes",
4729 .private = MEMFILE_PRIVATE(_MEMSWAP
, RES_MAX_USAGE
),
4730 .trigger
= mem_cgroup_reset
,
4731 .read_u64
= mem_cgroup_read
,
4734 .name
= "memsw.limit_in_bytes",
4735 .private = MEMFILE_PRIVATE(_MEMSWAP
, RES_LIMIT
),
4736 .write_string
= mem_cgroup_write
,
4737 .read_u64
= mem_cgroup_read
,
4740 .name
= "memsw.failcnt",
4741 .private = MEMFILE_PRIVATE(_MEMSWAP
, RES_FAILCNT
),
4742 .trigger
= mem_cgroup_reset
,
4743 .read_u64
= mem_cgroup_read
,
4747 static int register_memsw_files(struct cgroup
*cont
, struct cgroup_subsys
*ss
)
4749 if (!do_swap_account
)
4751 return cgroup_add_files(cont
, ss
, memsw_cgroup_files
,
4752 ARRAY_SIZE(memsw_cgroup_files
));
4755 static int register_memsw_files(struct cgroup
*cont
, struct cgroup_subsys
*ss
)
4761 static int alloc_mem_cgroup_per_zone_info(struct mem_cgroup
*mem
, int node
)
4763 struct mem_cgroup_per_node
*pn
;
4764 struct mem_cgroup_per_zone
*mz
;
4766 int zone
, tmp
= node
;
4768 * This routine is called against possible nodes.
4769 * But it's BUG to call kmalloc() against offline node.
4771 * TODO: this routine can waste much memory for nodes which will
4772 * never be onlined. It's better to use memory hotplug callback
4775 if (!node_state(node
, N_NORMAL_MEMORY
))
4777 pn
= kzalloc_node(sizeof(*pn
), GFP_KERNEL
, tmp
);
4781 mem
->info
.nodeinfo
[node
] = pn
;
4782 for (zone
= 0; zone
< MAX_NR_ZONES
; zone
++) {
4783 mz
= &pn
->zoneinfo
[zone
];
4785 INIT_LIST_HEAD(&mz
->lists
[l
]);
4786 mz
->usage_in_excess
= 0;
4787 mz
->on_tree
= false;
4793 static void free_mem_cgroup_per_zone_info(struct mem_cgroup
*mem
, int node
)
4795 kfree(mem
->info
.nodeinfo
[node
]);
4798 static struct mem_cgroup
*mem_cgroup_alloc(void)
4800 struct mem_cgroup
*mem
;
4801 int size
= sizeof(struct mem_cgroup
);
4803 /* Can be very big if MAX_NUMNODES is very big */
4804 if (size
< PAGE_SIZE
)
4805 mem
= kzalloc(size
, GFP_KERNEL
);
4807 mem
= vzalloc(size
);
4812 mem
->stat
= alloc_percpu(struct mem_cgroup_stat_cpu
);
4815 spin_lock_init(&mem
->pcp_counter_lock
);
4819 if (size
< PAGE_SIZE
)
4827 * At destroying mem_cgroup, references from swap_cgroup can remain.
4828 * (scanning all at force_empty is too costly...)
4830 * Instead of clearing all references at force_empty, we remember
4831 * the number of reference from swap_cgroup and free mem_cgroup when
4832 * it goes down to 0.
4834 * Removal of cgroup itself succeeds regardless of refs from swap.
4837 static void __mem_cgroup_free(struct mem_cgroup
*mem
)
4841 mem_cgroup_remove_from_trees(mem
);
4842 free_css_id(&mem_cgroup_subsys
, &mem
->css
);
4844 for_each_node_state(node
, N_POSSIBLE
)
4845 free_mem_cgroup_per_zone_info(mem
, node
);
4847 free_percpu(mem
->stat
);
4848 if (sizeof(struct mem_cgroup
) < PAGE_SIZE
)
4854 static void mem_cgroup_get(struct mem_cgroup
*mem
)
4856 atomic_inc(&mem
->refcnt
);
4859 static void __mem_cgroup_put(struct mem_cgroup
*mem
, int count
)
4861 if (atomic_sub_and_test(count
, &mem
->refcnt
)) {
4862 struct mem_cgroup
*parent
= parent_mem_cgroup(mem
);
4863 __mem_cgroup_free(mem
);
4865 mem_cgroup_put(parent
);
4869 static void mem_cgroup_put(struct mem_cgroup
*mem
)
4871 __mem_cgroup_put(mem
, 1);
4875 * Returns the parent mem_cgroup in memcgroup hierarchy with hierarchy enabled.
4877 static struct mem_cgroup
*parent_mem_cgroup(struct mem_cgroup
*mem
)
4879 if (!mem
->res
.parent
)
4881 return mem_cgroup_from_res_counter(mem
->res
.parent
, res
);
4884 #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP
4885 static void __init
enable_swap_cgroup(void)
4887 if (!mem_cgroup_disabled() && really_do_swap_account
)
4888 do_swap_account
= 1;
4891 static void __init
enable_swap_cgroup(void)
4896 static int mem_cgroup_soft_limit_tree_init(void)
4898 struct mem_cgroup_tree_per_node
*rtpn
;
4899 struct mem_cgroup_tree_per_zone
*rtpz
;
4900 int tmp
, node
, zone
;
4902 for_each_node_state(node
, N_POSSIBLE
) {
4904 if (!node_state(node
, N_NORMAL_MEMORY
))
4906 rtpn
= kzalloc_node(sizeof(*rtpn
), GFP_KERNEL
, tmp
);
4910 soft_limit_tree
.rb_tree_per_node
[node
] = rtpn
;
4912 for (zone
= 0; zone
< MAX_NR_ZONES
; zone
++) {
4913 rtpz
= &rtpn
->rb_tree_per_zone
[zone
];
4914 rtpz
->rb_root
= RB_ROOT
;
4915 spin_lock_init(&rtpz
->lock
);
4921 static struct cgroup_subsys_state
* __ref
4922 mem_cgroup_create(struct cgroup_subsys
*ss
, struct cgroup
*cont
)
4924 struct mem_cgroup
*mem
, *parent
;
4925 long error
= -ENOMEM
;
4928 mem
= mem_cgroup_alloc();
4930 return ERR_PTR(error
);
4932 for_each_node_state(node
, N_POSSIBLE
)
4933 if (alloc_mem_cgroup_per_zone_info(mem
, node
))
4937 if (cont
->parent
== NULL
) {
4939 enable_swap_cgroup();
4941 root_mem_cgroup
= mem
;
4942 if (mem_cgroup_soft_limit_tree_init())
4944 for_each_possible_cpu(cpu
) {
4945 struct memcg_stock_pcp
*stock
=
4946 &per_cpu(memcg_stock
, cpu
);
4947 INIT_WORK(&stock
->work
, drain_local_stock
);
4949 hotcpu_notifier(memcg_cpu_hotplug_callback
, 0);
4951 parent
= mem_cgroup_from_cont(cont
->parent
);
4952 mem
->use_hierarchy
= parent
->use_hierarchy
;
4953 mem
->oom_kill_disable
= parent
->oom_kill_disable
;
4956 if (parent
&& parent
->use_hierarchy
) {
4957 res_counter_init(&mem
->res
, &parent
->res
);
4958 res_counter_init(&mem
->memsw
, &parent
->memsw
);
4960 * We increment refcnt of the parent to ensure that we can
4961 * safely access it on res_counter_charge/uncharge.
4962 * This refcnt will be decremented when freeing this
4963 * mem_cgroup(see mem_cgroup_put).
4965 mem_cgroup_get(parent
);
4967 res_counter_init(&mem
->res
, NULL
);
4968 res_counter_init(&mem
->memsw
, NULL
);
4970 mem
->last_scanned_child
= 0;
4971 mem
->last_scanned_node
= MAX_NUMNODES
;
4972 INIT_LIST_HEAD(&mem
->oom_notify
);
4975 mem
->swappiness
= mem_cgroup_swappiness(parent
);
4976 atomic_set(&mem
->refcnt
, 1);
4977 mem
->move_charge_at_immigrate
= 0;
4978 mutex_init(&mem
->thresholds_lock
);
4981 __mem_cgroup_free(mem
);
4982 root_mem_cgroup
= NULL
;
4983 return ERR_PTR(error
);
4986 static int mem_cgroup_pre_destroy(struct cgroup_subsys
*ss
,
4987 struct cgroup
*cont
)
4989 struct mem_cgroup
*mem
= mem_cgroup_from_cont(cont
);
4991 return mem_cgroup_force_empty(mem
, false);
4994 static void mem_cgroup_destroy(struct cgroup_subsys
*ss
,
4995 struct cgroup
*cont
)
4997 struct mem_cgroup
*mem
= mem_cgroup_from_cont(cont
);
4999 mem_cgroup_put(mem
);
5002 static int mem_cgroup_populate(struct cgroup_subsys
*ss
,
5003 struct cgroup
*cont
)
5007 ret
= cgroup_add_files(cont
, ss
, mem_cgroup_files
,
5008 ARRAY_SIZE(mem_cgroup_files
));
5011 ret
= register_memsw_files(cont
, ss
);
5016 /* Handlers for move charge at task migration. */
5017 #define PRECHARGE_COUNT_AT_ONCE 256
5018 static int mem_cgroup_do_precharge(unsigned long count
)
5021 int batch_count
= PRECHARGE_COUNT_AT_ONCE
;
5022 struct mem_cgroup
*mem
= mc
.to
;
5024 if (mem_cgroup_is_root(mem
)) {
5025 mc
.precharge
+= count
;
5026 /* we don't need css_get for root */
5029 /* try to charge at once */
5031 struct res_counter
*dummy
;
5033 * "mem" cannot be under rmdir() because we've already checked
5034 * by cgroup_lock_live_cgroup() that it is not removed and we
5035 * are still under the same cgroup_mutex. So we can postpone
5038 if (res_counter_charge(&mem
->res
, PAGE_SIZE
* count
, &dummy
))
5040 if (do_swap_account
&& res_counter_charge(&mem
->memsw
,
5041 PAGE_SIZE
* count
, &dummy
)) {
5042 res_counter_uncharge(&mem
->res
, PAGE_SIZE
* count
);
5045 mc
.precharge
+= count
;
5049 /* fall back to one by one charge */
5051 if (signal_pending(current
)) {
5055 if (!batch_count
--) {
5056 batch_count
= PRECHARGE_COUNT_AT_ONCE
;
5059 ret
= __mem_cgroup_try_charge(NULL
, GFP_KERNEL
, 1, &mem
, false);
5061 /* mem_cgroup_clear_mc() will do uncharge later */
5069 * is_target_pte_for_mc - check a pte whether it is valid for move charge
5070 * @vma: the vma the pte to be checked belongs
5071 * @addr: the address corresponding to the pte to be checked
5072 * @ptent: the pte to be checked
5073 * @target: the pointer the target page or swap ent will be stored(can be NULL)
5076 * 0(MC_TARGET_NONE): if the pte is not a target for move charge.
5077 * 1(MC_TARGET_PAGE): if the page corresponding to this pte is a target for
5078 * move charge. if @target is not NULL, the page is stored in target->page
5079 * with extra refcnt got(Callers should handle it).
5080 * 2(MC_TARGET_SWAP): if the swap entry corresponding to this pte is a
5081 * target for charge migration. if @target is not NULL, the entry is stored
5084 * Called with pte lock held.
5091 enum mc_target_type
{
5092 MC_TARGET_NONE
, /* not used */
5097 static struct page
*mc_handle_present_pte(struct vm_area_struct
*vma
,
5098 unsigned long addr
, pte_t ptent
)
5100 struct page
*page
= vm_normal_page(vma
, addr
, ptent
);
5102 if (!page
|| !page_mapped(page
))
5104 if (PageAnon(page
)) {
5105 /* we don't move shared anon */
5106 if (!move_anon() || page_mapcount(page
) > 2)
5108 } else if (!move_file())
5109 /* we ignore mapcount for file pages */
5111 if (!get_page_unless_zero(page
))
5117 static struct page
*mc_handle_swap_pte(struct vm_area_struct
*vma
,
5118 unsigned long addr
, pte_t ptent
, swp_entry_t
*entry
)
5121 struct page
*page
= NULL
;
5122 swp_entry_t ent
= pte_to_swp_entry(ptent
);
5124 if (!move_anon() || non_swap_entry(ent
))
5126 usage_count
= mem_cgroup_count_swap_user(ent
, &page
);
5127 if (usage_count
> 1) { /* we don't move shared anon */
5132 if (do_swap_account
)
5133 entry
->val
= ent
.val
;
5138 static struct page
*mc_handle_file_pte(struct vm_area_struct
*vma
,
5139 unsigned long addr
, pte_t ptent
, swp_entry_t
*entry
)
5141 struct page
*page
= NULL
;
5142 struct inode
*inode
;
5143 struct address_space
*mapping
;
5146 if (!vma
->vm_file
) /* anonymous vma */
5151 inode
= vma
->vm_file
->f_path
.dentry
->d_inode
;
5152 mapping
= vma
->vm_file
->f_mapping
;
5153 if (pte_none(ptent
))
5154 pgoff
= linear_page_index(vma
, addr
);
5155 else /* pte_file(ptent) is true */
5156 pgoff
= pte_to_pgoff(ptent
);
5158 /* page is moved even if it's not RSS of this task(page-faulted). */
5159 if (!mapping_cap_swap_backed(mapping
)) { /* normal file */
5160 page
= find_get_page(mapping
, pgoff
);
5161 } else { /* shmem/tmpfs file. we should take account of swap too. */
5163 mem_cgroup_get_shmem_target(inode
, pgoff
, &page
, &ent
);
5164 if (do_swap_account
)
5165 entry
->val
= ent
.val
;
5171 static int is_target_pte_for_mc(struct vm_area_struct
*vma
,
5172 unsigned long addr
, pte_t ptent
, union mc_target
*target
)
5174 struct page
*page
= NULL
;
5175 struct page_cgroup
*pc
;
5177 swp_entry_t ent
= { .val
= 0 };
5179 if (pte_present(ptent
))
5180 page
= mc_handle_present_pte(vma
, addr
, ptent
);
5181 else if (is_swap_pte(ptent
))
5182 page
= mc_handle_swap_pte(vma
, addr
, ptent
, &ent
);
5183 else if (pte_none(ptent
) || pte_file(ptent
))
5184 page
= mc_handle_file_pte(vma
, addr
, ptent
, &ent
);
5186 if (!page
&& !ent
.val
)
5189 pc
= lookup_page_cgroup(page
);
5191 * Do only loose check w/o page_cgroup lock.
5192 * mem_cgroup_move_account() checks the pc is valid or not under
5195 if (PageCgroupUsed(pc
) && pc
->mem_cgroup
== mc
.from
) {
5196 ret
= MC_TARGET_PAGE
;
5198 target
->page
= page
;
5200 if (!ret
|| !target
)
5203 /* There is a swap entry and a page doesn't exist or isn't charged */
5204 if (ent
.val
&& !ret
&&
5205 css_id(&mc
.from
->css
) == lookup_swap_cgroup(ent
)) {
5206 ret
= MC_TARGET_SWAP
;
5213 static int mem_cgroup_count_precharge_pte_range(pmd_t
*pmd
,
5214 unsigned long addr
, unsigned long end
,
5215 struct mm_walk
*walk
)
5217 struct vm_area_struct
*vma
= walk
->private;
5221 split_huge_page_pmd(walk
->mm
, pmd
);
5223 pte
= pte_offset_map_lock(vma
->vm_mm
, pmd
, addr
, &ptl
);
5224 for (; addr
!= end
; pte
++, addr
+= PAGE_SIZE
)
5225 if (is_target_pte_for_mc(vma
, addr
, *pte
, NULL
))
5226 mc
.precharge
++; /* increment precharge temporarily */
5227 pte_unmap_unlock(pte
- 1, ptl
);
5233 static unsigned long mem_cgroup_count_precharge(struct mm_struct
*mm
)
5235 unsigned long precharge
;
5236 struct vm_area_struct
*vma
;
5238 down_read(&mm
->mmap_sem
);
5239 for (vma
= mm
->mmap
; vma
; vma
= vma
->vm_next
) {
5240 struct mm_walk mem_cgroup_count_precharge_walk
= {
5241 .pmd_entry
= mem_cgroup_count_precharge_pte_range
,
5245 if (is_vm_hugetlb_page(vma
))
5247 walk_page_range(vma
->vm_start
, vma
->vm_end
,
5248 &mem_cgroup_count_precharge_walk
);
5250 up_read(&mm
->mmap_sem
);
5252 precharge
= mc
.precharge
;
5258 static int mem_cgroup_precharge_mc(struct mm_struct
*mm
)
5260 unsigned long precharge
= mem_cgroup_count_precharge(mm
);
5262 VM_BUG_ON(mc
.moving_task
);
5263 mc
.moving_task
= current
;
5264 return mem_cgroup_do_precharge(precharge
);
5267 /* cancels all extra charges on mc.from and mc.to, and wakes up all waiters. */
5268 static void __mem_cgroup_clear_mc(void)
5270 struct mem_cgroup
*from
= mc
.from
;
5271 struct mem_cgroup
*to
= mc
.to
;
5273 /* we must uncharge all the leftover precharges from mc.to */
5275 __mem_cgroup_cancel_charge(mc
.to
, mc
.precharge
);
5279 * we didn't uncharge from mc.from at mem_cgroup_move_account(), so
5280 * we must uncharge here.
5282 if (mc
.moved_charge
) {
5283 __mem_cgroup_cancel_charge(mc
.from
, mc
.moved_charge
);
5284 mc
.moved_charge
= 0;
5286 /* we must fixup refcnts and charges */
5287 if (mc
.moved_swap
) {
5288 /* uncharge swap account from the old cgroup */
5289 if (!mem_cgroup_is_root(mc
.from
))
5290 res_counter_uncharge(&mc
.from
->memsw
,
5291 PAGE_SIZE
* mc
.moved_swap
);
5292 __mem_cgroup_put(mc
.from
, mc
.moved_swap
);
5294 if (!mem_cgroup_is_root(mc
.to
)) {
5296 * we charged both to->res and to->memsw, so we should
5299 res_counter_uncharge(&mc
.to
->res
,
5300 PAGE_SIZE
* mc
.moved_swap
);
5302 /* we've already done mem_cgroup_get(mc.to) */
5305 memcg_oom_recover(from
);
5306 memcg_oom_recover(to
);
5307 wake_up_all(&mc
.waitq
);
5310 static void mem_cgroup_clear_mc(void)
5312 struct mem_cgroup
*from
= mc
.from
;
5315 * we must clear moving_task before waking up waiters at the end of
5318 mc
.moving_task
= NULL
;
5319 __mem_cgroup_clear_mc();
5320 spin_lock(&mc
.lock
);
5323 spin_unlock(&mc
.lock
);
5324 mem_cgroup_end_move(from
);
5327 static int mem_cgroup_can_attach(struct cgroup_subsys
*ss
,
5328 struct cgroup
*cgroup
,
5329 struct task_struct
*p
)
5332 struct mem_cgroup
*mem
= mem_cgroup_from_cont(cgroup
);
5334 if (mem
->move_charge_at_immigrate
) {
5335 struct mm_struct
*mm
;
5336 struct mem_cgroup
*from
= mem_cgroup_from_task(p
);
5338 VM_BUG_ON(from
== mem
);
5340 mm
= get_task_mm(p
);
5343 /* We move charges only when we move a owner of the mm */
5344 if (mm
->owner
== p
) {
5347 VM_BUG_ON(mc
.precharge
);
5348 VM_BUG_ON(mc
.moved_charge
);
5349 VM_BUG_ON(mc
.moved_swap
);
5350 mem_cgroup_start_move(from
);
5351 spin_lock(&mc
.lock
);
5354 spin_unlock(&mc
.lock
);
5355 /* We set mc.moving_task later */
5357 ret
= mem_cgroup_precharge_mc(mm
);
5359 mem_cgroup_clear_mc();
5366 static void mem_cgroup_cancel_attach(struct cgroup_subsys
*ss
,
5367 struct cgroup
*cgroup
,
5368 struct task_struct
*p
)
5370 mem_cgroup_clear_mc();
5373 static int mem_cgroup_move_charge_pte_range(pmd_t
*pmd
,
5374 unsigned long addr
, unsigned long end
,
5375 struct mm_walk
*walk
)
5378 struct vm_area_struct
*vma
= walk
->private;
5382 split_huge_page_pmd(walk
->mm
, pmd
);
5384 pte
= pte_offset_map_lock(vma
->vm_mm
, pmd
, addr
, &ptl
);
5385 for (; addr
!= end
; addr
+= PAGE_SIZE
) {
5386 pte_t ptent
= *(pte
++);
5387 union mc_target target
;
5390 struct page_cgroup
*pc
;
5396 type
= is_target_pte_for_mc(vma
, addr
, ptent
, &target
);
5398 case MC_TARGET_PAGE
:
5400 if (isolate_lru_page(page
))
5402 pc
= lookup_page_cgroup(page
);
5403 if (!mem_cgroup_move_account(page
, 1, pc
,
5404 mc
.from
, mc
.to
, false)) {
5406 /* we uncharge from mc.from later. */
5409 putback_lru_page(page
);
5410 put
: /* is_target_pte_for_mc() gets the page */
5413 case MC_TARGET_SWAP
:
5415 if (!mem_cgroup_move_swap_account(ent
,
5416 mc
.from
, mc
.to
, false)) {
5418 /* we fixup refcnts and charges later. */
5426 pte_unmap_unlock(pte
- 1, ptl
);
5431 * We have consumed all precharges we got in can_attach().
5432 * We try charge one by one, but don't do any additional
5433 * charges to mc.to if we have failed in charge once in attach()
5436 ret
= mem_cgroup_do_precharge(1);
5444 static void mem_cgroup_move_charge(struct mm_struct
*mm
)
5446 struct vm_area_struct
*vma
;
5448 lru_add_drain_all();
5450 if (unlikely(!down_read_trylock(&mm
->mmap_sem
))) {
5452 * Someone who are holding the mmap_sem might be waiting in
5453 * waitq. So we cancel all extra charges, wake up all waiters,
5454 * and retry. Because we cancel precharges, we might not be able
5455 * to move enough charges, but moving charge is a best-effort
5456 * feature anyway, so it wouldn't be a big problem.
5458 __mem_cgroup_clear_mc();
5462 for (vma
= mm
->mmap
; vma
; vma
= vma
->vm_next
) {
5464 struct mm_walk mem_cgroup_move_charge_walk
= {
5465 .pmd_entry
= mem_cgroup_move_charge_pte_range
,
5469 if (is_vm_hugetlb_page(vma
))
5471 ret
= walk_page_range(vma
->vm_start
, vma
->vm_end
,
5472 &mem_cgroup_move_charge_walk
);
5475 * means we have consumed all precharges and failed in
5476 * doing additional charge. Just abandon here.
5480 up_read(&mm
->mmap_sem
);
5483 static void mem_cgroup_move_task(struct cgroup_subsys
*ss
,
5484 struct cgroup
*cont
,
5485 struct cgroup
*old_cont
,
5486 struct task_struct
*p
)
5488 struct mm_struct
*mm
= get_task_mm(p
);
5492 mem_cgroup_move_charge(mm
);
5497 mem_cgroup_clear_mc();
5499 #else /* !CONFIG_MMU */
5500 static int mem_cgroup_can_attach(struct cgroup_subsys
*ss
,
5501 struct cgroup
*cgroup
,
5502 struct task_struct
*p
)
5506 static void mem_cgroup_cancel_attach(struct cgroup_subsys
*ss
,
5507 struct cgroup
*cgroup
,
5508 struct task_struct
*p
)
5511 static void mem_cgroup_move_task(struct cgroup_subsys
*ss
,
5512 struct cgroup
*cont
,
5513 struct cgroup
*old_cont
,
5514 struct task_struct
*p
)
5519 struct cgroup_subsys mem_cgroup_subsys
= {
5521 .subsys_id
= mem_cgroup_subsys_id
,
5522 .create
= mem_cgroup_create
,
5523 .pre_destroy
= mem_cgroup_pre_destroy
,
5524 .destroy
= mem_cgroup_destroy
,
5525 .populate
= mem_cgroup_populate
,
5526 .can_attach
= mem_cgroup_can_attach
,
5527 .cancel_attach
= mem_cgroup_cancel_attach
,
5528 .attach
= mem_cgroup_move_task
,
5533 #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP
5534 static int __init
enable_swap_account(char *s
)
5536 /* consider enabled if no parameter or 1 is given */
5537 if (!strcmp(s
, "1"))
5538 really_do_swap_account
= 1;
5539 else if (!strcmp(s
, "0"))
5540 really_do_swap_account
= 0;
5543 __setup("swapaccount=", enable_swap_account
);