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/slab.h>
39 #include <linux/swap.h>
40 #include <linux/swapops.h>
41 #include <linux/spinlock.h>
42 #include <linux/eventfd.h>
43 #include <linux/sort.h>
45 #include <linux/seq_file.h>
46 #include <linux/vmalloc.h>
47 #include <linux/mm_inline.h>
48 #include <linux/page_cgroup.h>
49 #include <linux/cpu.h>
50 #include <linux/oom.h>
53 #include <asm/uaccess.h>
55 #include <trace/events/vmscan.h>
57 struct cgroup_subsys mem_cgroup_subsys __read_mostly
;
58 #define MEM_CGROUP_RECLAIM_RETRIES 5
59 struct mem_cgroup
*root_mem_cgroup __read_mostly
;
61 #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP
62 /* Turned on only when memory cgroup is enabled && really_do_swap_account = 1 */
63 int do_swap_account __read_mostly
;
65 /* for remember boot option*/
66 #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP_ENABLED
67 static int really_do_swap_account __initdata
= 1;
69 static int really_do_swap_account __initdata
= 0;
73 #define do_swap_account (0)
77 * Per memcg event counter is incremented at every pagein/pageout. This counter
78 * is used for trigger some periodic events. This is straightforward and better
79 * than using jiffies etc. to handle periodic memcg event.
81 * These values will be used as !((event) & ((1 <<(thresh)) - 1))
83 #define THRESHOLDS_EVENTS_THRESH (7) /* once in 128 */
84 #define SOFTLIMIT_EVENTS_THRESH (10) /* once in 1024 */
87 * Statistics for memory cgroup.
89 enum mem_cgroup_stat_index
{
91 * For MEM_CONTAINER_TYPE_ALL, usage = pagecache + rss.
93 MEM_CGROUP_STAT_CACHE
, /* # of pages charged as cache */
94 MEM_CGROUP_STAT_RSS
, /* # of pages charged as anon rss */
95 MEM_CGROUP_STAT_FILE_MAPPED
, /* # of pages charged as file rss */
96 MEM_CGROUP_STAT_PGPGIN_COUNT
, /* # of pages paged in */
97 MEM_CGROUP_STAT_PGPGOUT_COUNT
, /* # of pages paged out */
98 MEM_CGROUP_STAT_SWAPOUT
, /* # of pages, swapped out */
99 MEM_CGROUP_STAT_DATA
, /* end of data requires synchronization */
100 /* incremented at every pagein/pageout */
101 MEM_CGROUP_EVENTS
= MEM_CGROUP_STAT_DATA
,
102 MEM_CGROUP_ON_MOVE
, /* someone is moving account between groups */
104 MEM_CGROUP_STAT_NSTATS
,
107 struct mem_cgroup_stat_cpu
{
108 s64 count
[MEM_CGROUP_STAT_NSTATS
];
112 * per-zone information in memory controller.
114 struct mem_cgroup_per_zone
{
116 * spin_lock to protect the per cgroup LRU
118 struct list_head lists
[NR_LRU_LISTS
];
119 unsigned long count
[NR_LRU_LISTS
];
121 struct zone_reclaim_stat reclaim_stat
;
122 struct rb_node tree_node
; /* RB tree node */
123 unsigned long long usage_in_excess
;/* Set to the value by which */
124 /* the soft limit is exceeded*/
126 struct mem_cgroup
*mem
; /* Back pointer, we cannot */
127 /* use container_of */
129 /* Macro for accessing counter */
130 #define MEM_CGROUP_ZSTAT(mz, idx) ((mz)->count[(idx)])
132 struct mem_cgroup_per_node
{
133 struct mem_cgroup_per_zone zoneinfo
[MAX_NR_ZONES
];
136 struct mem_cgroup_lru_info
{
137 struct mem_cgroup_per_node
*nodeinfo
[MAX_NUMNODES
];
141 * Cgroups above their limits are maintained in a RB-Tree, independent of
142 * their hierarchy representation
145 struct mem_cgroup_tree_per_zone
{
146 struct rb_root rb_root
;
150 struct mem_cgroup_tree_per_node
{
151 struct mem_cgroup_tree_per_zone rb_tree_per_zone
[MAX_NR_ZONES
];
154 struct mem_cgroup_tree
{
155 struct mem_cgroup_tree_per_node
*rb_tree_per_node
[MAX_NUMNODES
];
158 static struct mem_cgroup_tree soft_limit_tree __read_mostly
;
160 struct mem_cgroup_threshold
{
161 struct eventfd_ctx
*eventfd
;
166 struct mem_cgroup_threshold_ary
{
167 /* An array index points to threshold just below usage. */
168 int current_threshold
;
169 /* Size of entries[] */
171 /* Array of thresholds */
172 struct mem_cgroup_threshold entries
[0];
175 struct mem_cgroup_thresholds
{
176 /* Primary thresholds array */
177 struct mem_cgroup_threshold_ary
*primary
;
179 * Spare threshold array.
180 * This is needed to make mem_cgroup_unregister_event() "never fail".
181 * It must be able to store at least primary->size - 1 entries.
183 struct mem_cgroup_threshold_ary
*spare
;
187 struct mem_cgroup_eventfd_list
{
188 struct list_head list
;
189 struct eventfd_ctx
*eventfd
;
192 static void mem_cgroup_threshold(struct mem_cgroup
*mem
);
193 static void mem_cgroup_oom_notify(struct mem_cgroup
*mem
);
196 * The memory controller data structure. The memory controller controls both
197 * page cache and RSS per cgroup. We would eventually like to provide
198 * statistics based on the statistics developed by Rik Van Riel for clock-pro,
199 * to help the administrator determine what knobs to tune.
201 * TODO: Add a water mark for the memory controller. Reclaim will begin when
202 * we hit the water mark. May be even add a low water mark, such that
203 * no reclaim occurs from a cgroup at it's low water mark, this is
204 * a feature that will be implemented much later in the future.
207 struct cgroup_subsys_state css
;
209 * the counter to account for memory usage
211 struct res_counter res
;
213 * the counter to account for mem+swap usage.
215 struct res_counter memsw
;
217 * Per cgroup active and inactive list, similar to the
218 * per zone LRU lists.
220 struct mem_cgroup_lru_info info
;
223 protect against reclaim related member.
225 spinlock_t reclaim_param_lock
;
228 * While reclaiming in a hierarchy, we cache the last child we
231 int last_scanned_child
;
233 * Should the accounting and control be hierarchical, per subtree?
239 unsigned int swappiness
;
240 /* OOM-Killer disable */
241 int oom_kill_disable
;
243 /* set when res.limit == memsw.limit */
244 bool memsw_is_minimum
;
246 /* protect arrays of thresholds */
247 struct mutex thresholds_lock
;
249 /* thresholds for memory usage. RCU-protected */
250 struct mem_cgroup_thresholds thresholds
;
252 /* thresholds for mem+swap usage. RCU-protected */
253 struct mem_cgroup_thresholds memsw_thresholds
;
255 /* For oom notifier event fd */
256 struct list_head oom_notify
;
259 * Should we move charges of a task when a task is moved into this
260 * mem_cgroup ? And what type of charges should we move ?
262 unsigned long move_charge_at_immigrate
;
266 struct mem_cgroup_stat_cpu
*stat
;
268 * used when a cpu is offlined or other synchronizations
269 * See mem_cgroup_read_stat().
271 struct mem_cgroup_stat_cpu nocpu_base
;
272 spinlock_t pcp_counter_lock
;
275 /* Stuffs for move charges at task migration. */
277 * Types of charges to be moved. "move_charge_at_immitgrate" is treated as a
278 * left-shifted bitmap of these types.
281 MOVE_CHARGE_TYPE_ANON
, /* private anonymous page and swap of it */
282 MOVE_CHARGE_TYPE_FILE
, /* file page(including tmpfs) and swap of it */
286 /* "mc" and its members are protected by cgroup_mutex */
287 static struct move_charge_struct
{
288 spinlock_t lock
; /* for from, to */
289 struct mem_cgroup
*from
;
290 struct mem_cgroup
*to
;
291 unsigned long precharge
;
292 unsigned long moved_charge
;
293 unsigned long moved_swap
;
294 struct task_struct
*moving_task
; /* a task moving charges */
295 struct mm_struct
*mm
;
296 wait_queue_head_t waitq
; /* a waitq for other context */
298 .lock
= __SPIN_LOCK_UNLOCKED(mc
.lock
),
299 .waitq
= __WAIT_QUEUE_HEAD_INITIALIZER(mc
.waitq
),
302 static bool move_anon(void)
304 return test_bit(MOVE_CHARGE_TYPE_ANON
,
305 &mc
.to
->move_charge_at_immigrate
);
308 static bool move_file(void)
310 return test_bit(MOVE_CHARGE_TYPE_FILE
,
311 &mc
.to
->move_charge_at_immigrate
);
315 * Maximum loops in mem_cgroup_hierarchical_reclaim(), used for soft
316 * limit reclaim to prevent infinite loops, if they ever occur.
318 #define MEM_CGROUP_MAX_RECLAIM_LOOPS (100)
319 #define MEM_CGROUP_MAX_SOFT_LIMIT_RECLAIM_LOOPS (2)
322 MEM_CGROUP_CHARGE_TYPE_CACHE
= 0,
323 MEM_CGROUP_CHARGE_TYPE_MAPPED
,
324 MEM_CGROUP_CHARGE_TYPE_SHMEM
, /* used by page migration of shmem */
325 MEM_CGROUP_CHARGE_TYPE_FORCE
, /* used by force_empty */
326 MEM_CGROUP_CHARGE_TYPE_SWAPOUT
, /* for accounting swapcache */
327 MEM_CGROUP_CHARGE_TYPE_DROP
, /* a page was unused swap cache */
331 /* only for here (for easy reading.) */
332 #define PCGF_CACHE (1UL << PCG_CACHE)
333 #define PCGF_USED (1UL << PCG_USED)
334 #define PCGF_LOCK (1UL << PCG_LOCK)
335 /* Not used, but added here for completeness */
336 #define PCGF_ACCT (1UL << PCG_ACCT)
338 /* for encoding cft->private value on file */
341 #define _OOM_TYPE (2)
342 #define MEMFILE_PRIVATE(x, val) (((x) << 16) | (val))
343 #define MEMFILE_TYPE(val) (((val) >> 16) & 0xffff)
344 #define MEMFILE_ATTR(val) ((val) & 0xffff)
345 /* Used for OOM nofiier */
346 #define OOM_CONTROL (0)
349 * Reclaim flags for mem_cgroup_hierarchical_reclaim
351 #define MEM_CGROUP_RECLAIM_NOSWAP_BIT 0x0
352 #define MEM_CGROUP_RECLAIM_NOSWAP (1 << MEM_CGROUP_RECLAIM_NOSWAP_BIT)
353 #define MEM_CGROUP_RECLAIM_SHRINK_BIT 0x1
354 #define MEM_CGROUP_RECLAIM_SHRINK (1 << MEM_CGROUP_RECLAIM_SHRINK_BIT)
355 #define MEM_CGROUP_RECLAIM_SOFT_BIT 0x2
356 #define MEM_CGROUP_RECLAIM_SOFT (1 << MEM_CGROUP_RECLAIM_SOFT_BIT)
358 static void mem_cgroup_get(struct mem_cgroup
*mem
);
359 static void mem_cgroup_put(struct mem_cgroup
*mem
);
360 static struct mem_cgroup
*parent_mem_cgroup(struct mem_cgroup
*mem
);
361 static void drain_all_stock_async(void);
363 static struct mem_cgroup_per_zone
*
364 mem_cgroup_zoneinfo(struct mem_cgroup
*mem
, int nid
, int zid
)
366 return &mem
->info
.nodeinfo
[nid
]->zoneinfo
[zid
];
369 struct cgroup_subsys_state
*mem_cgroup_css(struct mem_cgroup
*mem
)
374 static struct mem_cgroup_per_zone
*
375 page_cgroup_zoneinfo(struct page_cgroup
*pc
)
377 struct mem_cgroup
*mem
= pc
->mem_cgroup
;
378 int nid
= page_cgroup_nid(pc
);
379 int zid
= page_cgroup_zid(pc
);
384 return mem_cgroup_zoneinfo(mem
, nid
, zid
);
387 static struct mem_cgroup_tree_per_zone
*
388 soft_limit_tree_node_zone(int nid
, int zid
)
390 return &soft_limit_tree
.rb_tree_per_node
[nid
]->rb_tree_per_zone
[zid
];
393 static struct mem_cgroup_tree_per_zone
*
394 soft_limit_tree_from_page(struct page
*page
)
396 int nid
= page_to_nid(page
);
397 int zid
= page_zonenum(page
);
399 return &soft_limit_tree
.rb_tree_per_node
[nid
]->rb_tree_per_zone
[zid
];
403 __mem_cgroup_insert_exceeded(struct mem_cgroup
*mem
,
404 struct mem_cgroup_per_zone
*mz
,
405 struct mem_cgroup_tree_per_zone
*mctz
,
406 unsigned long long new_usage_in_excess
)
408 struct rb_node
**p
= &mctz
->rb_root
.rb_node
;
409 struct rb_node
*parent
= NULL
;
410 struct mem_cgroup_per_zone
*mz_node
;
415 mz
->usage_in_excess
= new_usage_in_excess
;
416 if (!mz
->usage_in_excess
)
420 mz_node
= rb_entry(parent
, struct mem_cgroup_per_zone
,
422 if (mz
->usage_in_excess
< mz_node
->usage_in_excess
)
425 * We can't avoid mem cgroups that are over their soft
426 * limit by the same amount
428 else if (mz
->usage_in_excess
>= mz_node
->usage_in_excess
)
431 rb_link_node(&mz
->tree_node
, parent
, p
);
432 rb_insert_color(&mz
->tree_node
, &mctz
->rb_root
);
437 __mem_cgroup_remove_exceeded(struct mem_cgroup
*mem
,
438 struct mem_cgroup_per_zone
*mz
,
439 struct mem_cgroup_tree_per_zone
*mctz
)
443 rb_erase(&mz
->tree_node
, &mctz
->rb_root
);
448 mem_cgroup_remove_exceeded(struct mem_cgroup
*mem
,
449 struct mem_cgroup_per_zone
*mz
,
450 struct mem_cgroup_tree_per_zone
*mctz
)
452 spin_lock(&mctz
->lock
);
453 __mem_cgroup_remove_exceeded(mem
, mz
, mctz
);
454 spin_unlock(&mctz
->lock
);
458 static void mem_cgroup_update_tree(struct mem_cgroup
*mem
, struct page
*page
)
460 unsigned long long excess
;
461 struct mem_cgroup_per_zone
*mz
;
462 struct mem_cgroup_tree_per_zone
*mctz
;
463 int nid
= page_to_nid(page
);
464 int zid
= page_zonenum(page
);
465 mctz
= soft_limit_tree_from_page(page
);
468 * Necessary to update all ancestors when hierarchy is used.
469 * because their event counter is not touched.
471 for (; mem
; mem
= parent_mem_cgroup(mem
)) {
472 mz
= mem_cgroup_zoneinfo(mem
, nid
, zid
);
473 excess
= res_counter_soft_limit_excess(&mem
->res
);
475 * We have to update the tree if mz is on RB-tree or
476 * mem is over its softlimit.
478 if (excess
|| mz
->on_tree
) {
479 spin_lock(&mctz
->lock
);
480 /* if on-tree, remove it */
482 __mem_cgroup_remove_exceeded(mem
, mz
, mctz
);
484 * Insert again. mz->usage_in_excess will be updated.
485 * If excess is 0, no tree ops.
487 __mem_cgroup_insert_exceeded(mem
, mz
, mctz
, excess
);
488 spin_unlock(&mctz
->lock
);
493 static void mem_cgroup_remove_from_trees(struct mem_cgroup
*mem
)
496 struct mem_cgroup_per_zone
*mz
;
497 struct mem_cgroup_tree_per_zone
*mctz
;
499 for_each_node_state(node
, N_POSSIBLE
) {
500 for (zone
= 0; zone
< MAX_NR_ZONES
; zone
++) {
501 mz
= mem_cgroup_zoneinfo(mem
, node
, zone
);
502 mctz
= soft_limit_tree_node_zone(node
, zone
);
503 mem_cgroup_remove_exceeded(mem
, mz
, mctz
);
508 static inline unsigned long mem_cgroup_get_excess(struct mem_cgroup
*mem
)
510 return res_counter_soft_limit_excess(&mem
->res
) >> PAGE_SHIFT
;
513 static struct mem_cgroup_per_zone
*
514 __mem_cgroup_largest_soft_limit_node(struct mem_cgroup_tree_per_zone
*mctz
)
516 struct rb_node
*rightmost
= NULL
;
517 struct mem_cgroup_per_zone
*mz
;
521 rightmost
= rb_last(&mctz
->rb_root
);
523 goto done
; /* Nothing to reclaim from */
525 mz
= rb_entry(rightmost
, struct mem_cgroup_per_zone
, tree_node
);
527 * Remove the node now but someone else can add it back,
528 * we will to add it back at the end of reclaim to its correct
529 * position in the tree.
531 __mem_cgroup_remove_exceeded(mz
->mem
, mz
, mctz
);
532 if (!res_counter_soft_limit_excess(&mz
->mem
->res
) ||
533 !css_tryget(&mz
->mem
->css
))
539 static struct mem_cgroup_per_zone
*
540 mem_cgroup_largest_soft_limit_node(struct mem_cgroup_tree_per_zone
*mctz
)
542 struct mem_cgroup_per_zone
*mz
;
544 spin_lock(&mctz
->lock
);
545 mz
= __mem_cgroup_largest_soft_limit_node(mctz
);
546 spin_unlock(&mctz
->lock
);
551 * Implementation Note: reading percpu statistics for memcg.
553 * Both of vmstat[] and percpu_counter has threshold and do periodic
554 * synchronization to implement "quick" read. There are trade-off between
555 * reading cost and precision of value. Then, we may have a chance to implement
556 * a periodic synchronizion of counter in memcg's counter.
558 * But this _read() function is used for user interface now. The user accounts
559 * memory usage by memory cgroup and he _always_ requires exact value because
560 * he accounts memory. Even if we provide quick-and-fuzzy read, we always
561 * have to visit all online cpus and make sum. So, for now, unnecessary
562 * synchronization is not implemented. (just implemented for cpu hotplug)
564 * If there are kernel internal actions which can make use of some not-exact
565 * value, and reading all cpu value can be performance bottleneck in some
566 * common workload, threashold and synchonization as vmstat[] should be
569 static s64
mem_cgroup_read_stat(struct mem_cgroup
*mem
,
570 enum mem_cgroup_stat_index idx
)
576 for_each_online_cpu(cpu
)
577 val
+= per_cpu(mem
->stat
->count
[idx
], cpu
);
578 #ifdef CONFIG_HOTPLUG_CPU
579 spin_lock(&mem
->pcp_counter_lock
);
580 val
+= mem
->nocpu_base
.count
[idx
];
581 spin_unlock(&mem
->pcp_counter_lock
);
587 static s64
mem_cgroup_local_usage(struct mem_cgroup
*mem
)
591 ret
= mem_cgroup_read_stat(mem
, MEM_CGROUP_STAT_RSS
);
592 ret
+= mem_cgroup_read_stat(mem
, MEM_CGROUP_STAT_CACHE
);
596 static void mem_cgroup_swap_statistics(struct mem_cgroup
*mem
,
599 int val
= (charge
) ? 1 : -1;
600 this_cpu_add(mem
->stat
->count
[MEM_CGROUP_STAT_SWAPOUT
], val
);
603 static void mem_cgroup_charge_statistics(struct mem_cgroup
*mem
,
604 struct page_cgroup
*pc
,
607 int val
= (charge
) ? 1 : -1;
611 if (PageCgroupCache(pc
))
612 __this_cpu_add(mem
->stat
->count
[MEM_CGROUP_STAT_CACHE
], val
);
614 __this_cpu_add(mem
->stat
->count
[MEM_CGROUP_STAT_RSS
], val
);
617 __this_cpu_inc(mem
->stat
->count
[MEM_CGROUP_STAT_PGPGIN_COUNT
]);
619 __this_cpu_inc(mem
->stat
->count
[MEM_CGROUP_STAT_PGPGOUT_COUNT
]);
620 __this_cpu_inc(mem
->stat
->count
[MEM_CGROUP_EVENTS
]);
625 static unsigned long mem_cgroup_get_local_zonestat(struct mem_cgroup
*mem
,
629 struct mem_cgroup_per_zone
*mz
;
632 for_each_online_node(nid
)
633 for (zid
= 0; zid
< MAX_NR_ZONES
; zid
++) {
634 mz
= mem_cgroup_zoneinfo(mem
, nid
, zid
);
635 total
+= MEM_CGROUP_ZSTAT(mz
, idx
);
640 static bool __memcg_event_check(struct mem_cgroup
*mem
, int event_mask_shift
)
644 val
= this_cpu_read(mem
->stat
->count
[MEM_CGROUP_EVENTS
]);
646 return !(val
& ((1 << event_mask_shift
) - 1));
650 * Check events in order.
653 static void memcg_check_events(struct mem_cgroup
*mem
, struct page
*page
)
655 /* threshold event is triggered in finer grain than soft limit */
656 if (unlikely(__memcg_event_check(mem
, THRESHOLDS_EVENTS_THRESH
))) {
657 mem_cgroup_threshold(mem
);
658 if (unlikely(__memcg_event_check(mem
, SOFTLIMIT_EVENTS_THRESH
)))
659 mem_cgroup_update_tree(mem
, page
);
663 static struct mem_cgroup
*mem_cgroup_from_cont(struct cgroup
*cont
)
665 return container_of(cgroup_subsys_state(cont
,
666 mem_cgroup_subsys_id
), struct mem_cgroup
,
670 struct mem_cgroup
*mem_cgroup_from_task(struct task_struct
*p
)
673 * mm_update_next_owner() may clear mm->owner to NULL
674 * if it races with swapoff, page migration, etc.
675 * So this can be called with p == NULL.
680 return container_of(task_subsys_state(p
, mem_cgroup_subsys_id
),
681 struct mem_cgroup
, css
);
684 static struct mem_cgroup
*try_get_mem_cgroup_from_mm(struct mm_struct
*mm
)
686 struct mem_cgroup
*mem
= NULL
;
691 * Because we have no locks, mm->owner's may be being moved to other
692 * cgroup. We use css_tryget() here even if this looks
693 * pessimistic (rather than adding locks here).
697 mem
= mem_cgroup_from_task(rcu_dereference(mm
->owner
));
700 } while (!css_tryget(&mem
->css
));
705 /* The caller has to guarantee "mem" exists before calling this */
706 static struct mem_cgroup
*mem_cgroup_start_loop(struct mem_cgroup
*mem
)
708 struct cgroup_subsys_state
*css
;
711 if (!mem
) /* ROOT cgroup has the smallest ID */
712 return root_mem_cgroup
; /*css_put/get against root is ignored*/
713 if (!mem
->use_hierarchy
) {
714 if (css_tryget(&mem
->css
))
720 * searching a memory cgroup which has the smallest ID under given
721 * ROOT cgroup. (ID >= 1)
723 css
= css_get_next(&mem_cgroup_subsys
, 1, &mem
->css
, &found
);
724 if (css
&& css_tryget(css
))
725 mem
= container_of(css
, struct mem_cgroup
, css
);
732 static struct mem_cgroup
*mem_cgroup_get_next(struct mem_cgroup
*iter
,
733 struct mem_cgroup
*root
,
736 int nextid
= css_id(&iter
->css
) + 1;
739 struct cgroup_subsys_state
*css
;
741 hierarchy_used
= iter
->use_hierarchy
;
744 /* If no ROOT, walk all, ignore hierarchy */
745 if (!cond
|| (root
&& !hierarchy_used
))
749 root
= root_mem_cgroup
;
755 css
= css_get_next(&mem_cgroup_subsys
, nextid
,
757 if (css
&& css_tryget(css
))
758 iter
= container_of(css
, struct mem_cgroup
, css
);
760 /* If css is NULL, no more cgroups will be found */
762 } while (css
&& !iter
);
767 * for_eacn_mem_cgroup_tree() for visiting all cgroup under tree. Please
768 * be careful that "break" loop is not allowed. We have reference count.
769 * Instead of that modify "cond" to be false and "continue" to exit the loop.
771 #define for_each_mem_cgroup_tree_cond(iter, root, cond) \
772 for (iter = mem_cgroup_start_loop(root);\
774 iter = mem_cgroup_get_next(iter, root, cond))
776 #define for_each_mem_cgroup_tree(iter, root) \
777 for_each_mem_cgroup_tree_cond(iter, root, true)
779 #define for_each_mem_cgroup_all(iter) \
780 for_each_mem_cgroup_tree_cond(iter, NULL, true)
783 static inline bool mem_cgroup_is_root(struct mem_cgroup
*mem
)
785 return (mem
== root_mem_cgroup
);
789 * Following LRU functions are allowed to be used without PCG_LOCK.
790 * Operations are called by routine of global LRU independently from memcg.
791 * What we have to take care of here is validness of pc->mem_cgroup.
793 * Changes to pc->mem_cgroup happens when
796 * In typical case, "charge" is done before add-to-lru. Exception is SwapCache.
797 * It is added to LRU before charge.
798 * If PCG_USED bit is not set, page_cgroup is not added to this private LRU.
799 * When moving account, the page is not on LRU. It's isolated.
802 void mem_cgroup_del_lru_list(struct page
*page
, enum lru_list lru
)
804 struct page_cgroup
*pc
;
805 struct mem_cgroup_per_zone
*mz
;
807 if (mem_cgroup_disabled())
809 pc
= lookup_page_cgroup(page
);
810 /* can happen while we handle swapcache. */
811 if (!TestClearPageCgroupAcctLRU(pc
))
813 VM_BUG_ON(!pc
->mem_cgroup
);
815 * We don't check PCG_USED bit. It's cleared when the "page" is finally
816 * removed from global LRU.
818 mz
= page_cgroup_zoneinfo(pc
);
819 MEM_CGROUP_ZSTAT(mz
, lru
) -= 1;
820 if (mem_cgroup_is_root(pc
->mem_cgroup
))
822 VM_BUG_ON(list_empty(&pc
->lru
));
823 list_del_init(&pc
->lru
);
827 void mem_cgroup_del_lru(struct page
*page
)
829 mem_cgroup_del_lru_list(page
, page_lru(page
));
832 void mem_cgroup_rotate_lru_list(struct page
*page
, enum lru_list lru
)
834 struct mem_cgroup_per_zone
*mz
;
835 struct page_cgroup
*pc
;
837 if (mem_cgroup_disabled())
840 pc
= lookup_page_cgroup(page
);
842 * Used bit is set without atomic ops but after smp_wmb().
843 * For making pc->mem_cgroup visible, insert smp_rmb() here.
846 /* unused or root page is not rotated. */
847 if (!PageCgroupUsed(pc
) || mem_cgroup_is_root(pc
->mem_cgroup
))
849 mz
= page_cgroup_zoneinfo(pc
);
850 list_move(&pc
->lru
, &mz
->lists
[lru
]);
853 void mem_cgroup_add_lru_list(struct page
*page
, enum lru_list lru
)
855 struct page_cgroup
*pc
;
856 struct mem_cgroup_per_zone
*mz
;
858 if (mem_cgroup_disabled())
860 pc
= lookup_page_cgroup(page
);
861 VM_BUG_ON(PageCgroupAcctLRU(pc
));
863 * Used bit is set without atomic ops but after smp_wmb().
864 * For making pc->mem_cgroup visible, insert smp_rmb() here.
867 if (!PageCgroupUsed(pc
))
870 mz
= page_cgroup_zoneinfo(pc
);
871 MEM_CGROUP_ZSTAT(mz
, lru
) += 1;
872 SetPageCgroupAcctLRU(pc
);
873 if (mem_cgroup_is_root(pc
->mem_cgroup
))
875 list_add(&pc
->lru
, &mz
->lists
[lru
]);
879 * At handling SwapCache, pc->mem_cgroup may be changed while it's linked to
880 * lru because the page may.be reused after it's fully uncharged (because of
881 * SwapCache behavior).To handle that, unlink page_cgroup from LRU when charge
882 * it again. This function is only used to charge SwapCache. It's done under
883 * lock_page and expected that zone->lru_lock is never held.
885 static void mem_cgroup_lru_del_before_commit_swapcache(struct page
*page
)
888 struct zone
*zone
= page_zone(page
);
889 struct page_cgroup
*pc
= lookup_page_cgroup(page
);
891 spin_lock_irqsave(&zone
->lru_lock
, flags
);
893 * Forget old LRU when this page_cgroup is *not* used. This Used bit
894 * is guarded by lock_page() because the page is SwapCache.
896 if (!PageCgroupUsed(pc
))
897 mem_cgroup_del_lru_list(page
, page_lru(page
));
898 spin_unlock_irqrestore(&zone
->lru_lock
, flags
);
901 static void mem_cgroup_lru_add_after_commit_swapcache(struct page
*page
)
904 struct zone
*zone
= page_zone(page
);
905 struct page_cgroup
*pc
= lookup_page_cgroup(page
);
907 spin_lock_irqsave(&zone
->lru_lock
, flags
);
908 /* link when the page is linked to LRU but page_cgroup isn't */
909 if (PageLRU(page
) && !PageCgroupAcctLRU(pc
))
910 mem_cgroup_add_lru_list(page
, page_lru(page
));
911 spin_unlock_irqrestore(&zone
->lru_lock
, flags
);
915 void mem_cgroup_move_lists(struct page
*page
,
916 enum lru_list from
, enum lru_list to
)
918 if (mem_cgroup_disabled())
920 mem_cgroup_del_lru_list(page
, from
);
921 mem_cgroup_add_lru_list(page
, to
);
924 int task_in_mem_cgroup(struct task_struct
*task
, const struct mem_cgroup
*mem
)
927 struct mem_cgroup
*curr
= NULL
;
928 struct task_struct
*p
;
930 p
= find_lock_task_mm(task
);
933 curr
= try_get_mem_cgroup_from_mm(p
->mm
);
938 * We should check use_hierarchy of "mem" not "curr". Because checking
939 * use_hierarchy of "curr" here make this function true if hierarchy is
940 * enabled in "curr" and "curr" is a child of "mem" in *cgroup*
941 * hierarchy(even if use_hierarchy is disabled in "mem").
943 if (mem
->use_hierarchy
)
944 ret
= css_is_ancestor(&curr
->css
, &mem
->css
);
951 static int calc_inactive_ratio(struct mem_cgroup
*memcg
, unsigned long *present_pages
)
953 unsigned long active
;
954 unsigned long inactive
;
956 unsigned long inactive_ratio
;
958 inactive
= mem_cgroup_get_local_zonestat(memcg
, LRU_INACTIVE_ANON
);
959 active
= mem_cgroup_get_local_zonestat(memcg
, LRU_ACTIVE_ANON
);
961 gb
= (inactive
+ active
) >> (30 - PAGE_SHIFT
);
963 inactive_ratio
= int_sqrt(10 * gb
);
968 present_pages
[0] = inactive
;
969 present_pages
[1] = active
;
972 return inactive_ratio
;
975 int mem_cgroup_inactive_anon_is_low(struct mem_cgroup
*memcg
)
977 unsigned long active
;
978 unsigned long inactive
;
979 unsigned long present_pages
[2];
980 unsigned long inactive_ratio
;
982 inactive_ratio
= calc_inactive_ratio(memcg
, present_pages
);
984 inactive
= present_pages
[0];
985 active
= present_pages
[1];
987 if (inactive
* inactive_ratio
< active
)
993 int mem_cgroup_inactive_file_is_low(struct mem_cgroup
*memcg
)
995 unsigned long active
;
996 unsigned long inactive
;
998 inactive
= mem_cgroup_get_local_zonestat(memcg
, LRU_INACTIVE_FILE
);
999 active
= mem_cgroup_get_local_zonestat(memcg
, LRU_ACTIVE_FILE
);
1001 return (active
> inactive
);
1004 unsigned long mem_cgroup_zone_nr_pages(struct mem_cgroup
*memcg
,
1008 int nid
= zone_to_nid(zone
);
1009 int zid
= zone_idx(zone
);
1010 struct mem_cgroup_per_zone
*mz
= mem_cgroup_zoneinfo(memcg
, nid
, zid
);
1012 return MEM_CGROUP_ZSTAT(mz
, lru
);
1015 struct zone_reclaim_stat
*mem_cgroup_get_reclaim_stat(struct mem_cgroup
*memcg
,
1018 int nid
= zone_to_nid(zone
);
1019 int zid
= zone_idx(zone
);
1020 struct mem_cgroup_per_zone
*mz
= mem_cgroup_zoneinfo(memcg
, nid
, zid
);
1022 return &mz
->reclaim_stat
;
1025 struct zone_reclaim_stat
*
1026 mem_cgroup_get_reclaim_stat_from_page(struct page
*page
)
1028 struct page_cgroup
*pc
;
1029 struct mem_cgroup_per_zone
*mz
;
1030 int page_size
= PAGE_SIZE
;
1032 if (PageTransHuge(page
))
1033 page_size
<<= compound_order(page
);
1035 if (mem_cgroup_disabled())
1038 pc
= lookup_page_cgroup(page
);
1040 * Used bit is set without atomic ops but after smp_wmb().
1041 * For making pc->mem_cgroup visible, insert smp_rmb() here.
1044 if (!PageCgroupUsed(pc
))
1047 mz
= page_cgroup_zoneinfo(pc
);
1051 return &mz
->reclaim_stat
;
1054 unsigned long mem_cgroup_isolate_pages(unsigned long nr_to_scan
,
1055 struct list_head
*dst
,
1056 unsigned long *scanned
, int order
,
1057 int mode
, struct zone
*z
,
1058 struct mem_cgroup
*mem_cont
,
1059 int active
, int file
)
1061 unsigned long nr_taken
= 0;
1065 struct list_head
*src
;
1066 struct page_cgroup
*pc
, *tmp
;
1067 int nid
= zone_to_nid(z
);
1068 int zid
= zone_idx(z
);
1069 struct mem_cgroup_per_zone
*mz
;
1070 int lru
= LRU_FILE
* file
+ active
;
1074 mz
= mem_cgroup_zoneinfo(mem_cont
, nid
, zid
);
1075 src
= &mz
->lists
[lru
];
1078 list_for_each_entry_safe_reverse(pc
, tmp
, src
, lru
) {
1079 if (scan
>= nr_to_scan
)
1083 if (unlikely(!PageCgroupUsed(pc
)))
1085 if (unlikely(!PageLRU(page
)))
1089 ret
= __isolate_lru_page(page
, mode
, file
);
1092 list_move(&page
->lru
, dst
);
1093 mem_cgroup_del_lru(page
);
1097 /* we don't affect global LRU but rotate in our LRU */
1098 mem_cgroup_rotate_lru_list(page
, page_lru(page
));
1107 trace_mm_vmscan_memcg_isolate(0, nr_to_scan
, scan
, nr_taken
,
1113 #define mem_cgroup_from_res_counter(counter, member) \
1114 container_of(counter, struct mem_cgroup, member)
1116 static bool mem_cgroup_check_under_limit(struct mem_cgroup
*mem
)
1118 if (do_swap_account
) {
1119 if (res_counter_check_under_limit(&mem
->res
) &&
1120 res_counter_check_under_limit(&mem
->memsw
))
1123 if (res_counter_check_under_limit(&mem
->res
))
1128 static unsigned int get_swappiness(struct mem_cgroup
*memcg
)
1130 struct cgroup
*cgrp
= memcg
->css
.cgroup
;
1131 unsigned int swappiness
;
1134 if (cgrp
->parent
== NULL
)
1135 return vm_swappiness
;
1137 spin_lock(&memcg
->reclaim_param_lock
);
1138 swappiness
= memcg
->swappiness
;
1139 spin_unlock(&memcg
->reclaim_param_lock
);
1144 static void mem_cgroup_start_move(struct mem_cgroup
*mem
)
1149 spin_lock(&mem
->pcp_counter_lock
);
1150 for_each_online_cpu(cpu
)
1151 per_cpu(mem
->stat
->count
[MEM_CGROUP_ON_MOVE
], cpu
) += 1;
1152 mem
->nocpu_base
.count
[MEM_CGROUP_ON_MOVE
] += 1;
1153 spin_unlock(&mem
->pcp_counter_lock
);
1159 static void mem_cgroup_end_move(struct mem_cgroup
*mem
)
1166 spin_lock(&mem
->pcp_counter_lock
);
1167 for_each_online_cpu(cpu
)
1168 per_cpu(mem
->stat
->count
[MEM_CGROUP_ON_MOVE
], cpu
) -= 1;
1169 mem
->nocpu_base
.count
[MEM_CGROUP_ON_MOVE
] -= 1;
1170 spin_unlock(&mem
->pcp_counter_lock
);
1174 * 2 routines for checking "mem" is under move_account() or not.
1176 * mem_cgroup_stealed() - checking a cgroup is mc.from or not. This is used
1177 * for avoiding race in accounting. If true,
1178 * pc->mem_cgroup may be overwritten.
1180 * mem_cgroup_under_move() - checking a cgroup is mc.from or mc.to or
1181 * under hierarchy of moving cgroups. This is for
1182 * waiting at hith-memory prressure caused by "move".
1185 static bool mem_cgroup_stealed(struct mem_cgroup
*mem
)
1187 VM_BUG_ON(!rcu_read_lock_held());
1188 return this_cpu_read(mem
->stat
->count
[MEM_CGROUP_ON_MOVE
]) > 0;
1191 static bool mem_cgroup_under_move(struct mem_cgroup
*mem
)
1193 struct mem_cgroup
*from
;
1194 struct mem_cgroup
*to
;
1197 * Unlike task_move routines, we access mc.to, mc.from not under
1198 * mutual exclusion by cgroup_mutex. Here, we take spinlock instead.
1200 spin_lock(&mc
.lock
);
1205 if (from
== mem
|| to
== mem
1206 || (mem
->use_hierarchy
&& css_is_ancestor(&from
->css
, &mem
->css
))
1207 || (mem
->use_hierarchy
&& css_is_ancestor(&to
->css
, &mem
->css
)))
1210 spin_unlock(&mc
.lock
);
1214 static bool mem_cgroup_wait_acct_move(struct mem_cgroup
*mem
)
1216 if (mc
.moving_task
&& current
!= mc
.moving_task
) {
1217 if (mem_cgroup_under_move(mem
)) {
1219 prepare_to_wait(&mc
.waitq
, &wait
, TASK_INTERRUPTIBLE
);
1220 /* moving charge context might have finished. */
1223 finish_wait(&mc
.waitq
, &wait
);
1231 * mem_cgroup_print_oom_info: Called from OOM with tasklist_lock held in read mode.
1232 * @memcg: The memory cgroup that went over limit
1233 * @p: Task that is going to be killed
1235 * NOTE: @memcg and @p's mem_cgroup can be different when hierarchy is
1238 void mem_cgroup_print_oom_info(struct mem_cgroup
*memcg
, struct task_struct
*p
)
1240 struct cgroup
*task_cgrp
;
1241 struct cgroup
*mem_cgrp
;
1243 * Need a buffer in BSS, can't rely on allocations. The code relies
1244 * on the assumption that OOM is serialized for memory controller.
1245 * If this assumption is broken, revisit this code.
1247 static char memcg_name
[PATH_MAX
];
1256 mem_cgrp
= memcg
->css
.cgroup
;
1257 task_cgrp
= task_cgroup(p
, mem_cgroup_subsys_id
);
1259 ret
= cgroup_path(task_cgrp
, memcg_name
, PATH_MAX
);
1262 * Unfortunately, we are unable to convert to a useful name
1263 * But we'll still print out the usage information
1270 printk(KERN_INFO
"Task in %s killed", memcg_name
);
1273 ret
= cgroup_path(mem_cgrp
, memcg_name
, PATH_MAX
);
1281 * Continues from above, so we don't need an KERN_ level
1283 printk(KERN_CONT
" as a result of limit of %s\n", memcg_name
);
1286 printk(KERN_INFO
"memory: usage %llukB, limit %llukB, failcnt %llu\n",
1287 res_counter_read_u64(&memcg
->res
, RES_USAGE
) >> 10,
1288 res_counter_read_u64(&memcg
->res
, RES_LIMIT
) >> 10,
1289 res_counter_read_u64(&memcg
->res
, RES_FAILCNT
));
1290 printk(KERN_INFO
"memory+swap: usage %llukB, limit %llukB, "
1292 res_counter_read_u64(&memcg
->memsw
, RES_USAGE
) >> 10,
1293 res_counter_read_u64(&memcg
->memsw
, RES_LIMIT
) >> 10,
1294 res_counter_read_u64(&memcg
->memsw
, RES_FAILCNT
));
1298 * This function returns the number of memcg under hierarchy tree. Returns
1299 * 1(self count) if no children.
1301 static int mem_cgroup_count_children(struct mem_cgroup
*mem
)
1304 struct mem_cgroup
*iter
;
1306 for_each_mem_cgroup_tree(iter
, mem
)
1312 * Return the memory (and swap, if configured) limit for a memcg.
1314 u64
mem_cgroup_get_limit(struct mem_cgroup
*memcg
)
1319 limit
= res_counter_read_u64(&memcg
->res
, RES_LIMIT
) +
1321 memsw
= res_counter_read_u64(&memcg
->memsw
, RES_LIMIT
);
1323 * If memsw is finite and limits the amount of swap space available
1324 * to this memcg, return that limit.
1326 return min(limit
, memsw
);
1330 * Visit the first child (need not be the first child as per the ordering
1331 * of the cgroup list, since we track last_scanned_child) of @mem and use
1332 * that to reclaim free pages from.
1334 static struct mem_cgroup
*
1335 mem_cgroup_select_victim(struct mem_cgroup
*root_mem
)
1337 struct mem_cgroup
*ret
= NULL
;
1338 struct cgroup_subsys_state
*css
;
1341 if (!root_mem
->use_hierarchy
) {
1342 css_get(&root_mem
->css
);
1348 nextid
= root_mem
->last_scanned_child
+ 1;
1349 css
= css_get_next(&mem_cgroup_subsys
, nextid
, &root_mem
->css
,
1351 if (css
&& css_tryget(css
))
1352 ret
= container_of(css
, struct mem_cgroup
, css
);
1355 /* Updates scanning parameter */
1356 spin_lock(&root_mem
->reclaim_param_lock
);
1358 /* this means start scan from ID:1 */
1359 root_mem
->last_scanned_child
= 0;
1361 root_mem
->last_scanned_child
= found
;
1362 spin_unlock(&root_mem
->reclaim_param_lock
);
1369 * Scan the hierarchy if needed to reclaim memory. We remember the last child
1370 * we reclaimed from, so that we don't end up penalizing one child extensively
1371 * based on its position in the children list.
1373 * root_mem is the original ancestor that we've been reclaim from.
1375 * We give up and return to the caller when we visit root_mem twice.
1376 * (other groups can be removed while we're walking....)
1378 * If shrink==true, for avoiding to free too much, this returns immedieately.
1380 static int mem_cgroup_hierarchical_reclaim(struct mem_cgroup
*root_mem
,
1383 unsigned long reclaim_options
)
1385 struct mem_cgroup
*victim
;
1388 bool noswap
= reclaim_options
& MEM_CGROUP_RECLAIM_NOSWAP
;
1389 bool shrink
= reclaim_options
& MEM_CGROUP_RECLAIM_SHRINK
;
1390 bool check_soft
= reclaim_options
& MEM_CGROUP_RECLAIM_SOFT
;
1391 unsigned long excess
= mem_cgroup_get_excess(root_mem
);
1393 /* If memsw_is_minimum==1, swap-out is of-no-use. */
1394 if (root_mem
->memsw_is_minimum
)
1398 victim
= mem_cgroup_select_victim(root_mem
);
1399 if (victim
== root_mem
) {
1402 drain_all_stock_async();
1405 * If we have not been able to reclaim
1406 * anything, it might because there are
1407 * no reclaimable pages under this hierarchy
1409 if (!check_soft
|| !total
) {
1410 css_put(&victim
->css
);
1414 * We want to do more targetted reclaim.
1415 * excess >> 2 is not to excessive so as to
1416 * reclaim too much, nor too less that we keep
1417 * coming back to reclaim from this cgroup
1419 if (total
>= (excess
>> 2) ||
1420 (loop
> MEM_CGROUP_MAX_RECLAIM_LOOPS
)) {
1421 css_put(&victim
->css
);
1426 if (!mem_cgroup_local_usage(victim
)) {
1427 /* this cgroup's local usage == 0 */
1428 css_put(&victim
->css
);
1431 /* we use swappiness of local cgroup */
1433 ret
= mem_cgroup_shrink_node_zone(victim
, gfp_mask
,
1434 noswap
, get_swappiness(victim
), zone
);
1436 ret
= try_to_free_mem_cgroup_pages(victim
, gfp_mask
,
1437 noswap
, get_swappiness(victim
));
1438 css_put(&victim
->css
);
1440 * At shrinking usage, we can't check we should stop here or
1441 * reclaim more. It's depends on callers. last_scanned_child
1442 * will work enough for keeping fairness under tree.
1448 if (res_counter_check_under_soft_limit(&root_mem
->res
))
1450 } else if (mem_cgroup_check_under_limit(root_mem
))
1457 * Check OOM-Killer is already running under our hierarchy.
1458 * If someone is running, return false.
1460 static bool mem_cgroup_oom_lock(struct mem_cgroup
*mem
)
1462 int x
, lock_count
= 0;
1463 struct mem_cgroup
*iter
;
1465 for_each_mem_cgroup_tree(iter
, mem
) {
1466 x
= atomic_inc_return(&iter
->oom_lock
);
1467 lock_count
= max(x
, lock_count
);
1470 if (lock_count
== 1)
1475 static int mem_cgroup_oom_unlock(struct mem_cgroup
*mem
)
1477 struct mem_cgroup
*iter
;
1480 * When a new child is created while the hierarchy is under oom,
1481 * mem_cgroup_oom_lock() may not be called. We have to use
1482 * atomic_add_unless() here.
1484 for_each_mem_cgroup_tree(iter
, mem
)
1485 atomic_add_unless(&iter
->oom_lock
, -1, 0);
1490 static DEFINE_MUTEX(memcg_oom_mutex
);
1491 static DECLARE_WAIT_QUEUE_HEAD(memcg_oom_waitq
);
1493 struct oom_wait_info
{
1494 struct mem_cgroup
*mem
;
1498 static int memcg_oom_wake_function(wait_queue_t
*wait
,
1499 unsigned mode
, int sync
, void *arg
)
1501 struct mem_cgroup
*wake_mem
= (struct mem_cgroup
*)arg
;
1502 struct oom_wait_info
*oom_wait_info
;
1504 oom_wait_info
= container_of(wait
, struct oom_wait_info
, wait
);
1506 if (oom_wait_info
->mem
== wake_mem
)
1508 /* if no hierarchy, no match */
1509 if (!oom_wait_info
->mem
->use_hierarchy
|| !wake_mem
->use_hierarchy
)
1512 * Both of oom_wait_info->mem and wake_mem are stable under us.
1513 * Then we can use css_is_ancestor without taking care of RCU.
1515 if (!css_is_ancestor(&oom_wait_info
->mem
->css
, &wake_mem
->css
) &&
1516 !css_is_ancestor(&wake_mem
->css
, &oom_wait_info
->mem
->css
))
1520 return autoremove_wake_function(wait
, mode
, sync
, arg
);
1523 static void memcg_wakeup_oom(struct mem_cgroup
*mem
)
1525 /* for filtering, pass "mem" as argument. */
1526 __wake_up(&memcg_oom_waitq
, TASK_NORMAL
, 0, mem
);
1529 static void memcg_oom_recover(struct mem_cgroup
*mem
)
1531 if (mem
&& atomic_read(&mem
->oom_lock
))
1532 memcg_wakeup_oom(mem
);
1536 * try to call OOM killer. returns false if we should exit memory-reclaim loop.
1538 bool mem_cgroup_handle_oom(struct mem_cgroup
*mem
, gfp_t mask
)
1540 struct oom_wait_info owait
;
1541 bool locked
, need_to_kill
;
1544 owait
.wait
.flags
= 0;
1545 owait
.wait
.func
= memcg_oom_wake_function
;
1546 owait
.wait
.private = current
;
1547 INIT_LIST_HEAD(&owait
.wait
.task_list
);
1548 need_to_kill
= true;
1549 /* At first, try to OOM lock hierarchy under mem.*/
1550 mutex_lock(&memcg_oom_mutex
);
1551 locked
= mem_cgroup_oom_lock(mem
);
1553 * Even if signal_pending(), we can't quit charge() loop without
1554 * accounting. So, UNINTERRUPTIBLE is appropriate. But SIGKILL
1555 * under OOM is always welcomed, use TASK_KILLABLE here.
1557 prepare_to_wait(&memcg_oom_waitq
, &owait
.wait
, TASK_KILLABLE
);
1558 if (!locked
|| mem
->oom_kill_disable
)
1559 need_to_kill
= false;
1561 mem_cgroup_oom_notify(mem
);
1562 mutex_unlock(&memcg_oom_mutex
);
1565 finish_wait(&memcg_oom_waitq
, &owait
.wait
);
1566 mem_cgroup_out_of_memory(mem
, mask
);
1569 finish_wait(&memcg_oom_waitq
, &owait
.wait
);
1571 mutex_lock(&memcg_oom_mutex
);
1572 mem_cgroup_oom_unlock(mem
);
1573 memcg_wakeup_oom(mem
);
1574 mutex_unlock(&memcg_oom_mutex
);
1576 if (test_thread_flag(TIF_MEMDIE
) || fatal_signal_pending(current
))
1578 /* Give chance to dying process */
1579 schedule_timeout(1);
1584 * Currently used to update mapped file statistics, but the routine can be
1585 * generalized to update other statistics as well.
1587 * Notes: Race condition
1589 * We usually use page_cgroup_lock() for accessing page_cgroup member but
1590 * it tends to be costly. But considering some conditions, we doesn't need
1591 * to do so _always_.
1593 * Considering "charge", lock_page_cgroup() is not required because all
1594 * file-stat operations happen after a page is attached to radix-tree. There
1595 * are no race with "charge".
1597 * Considering "uncharge", we know that memcg doesn't clear pc->mem_cgroup
1598 * at "uncharge" intentionally. So, we always see valid pc->mem_cgroup even
1599 * if there are race with "uncharge". Statistics itself is properly handled
1602 * Considering "move", this is an only case we see a race. To make the race
1603 * small, we check MEM_CGROUP_ON_MOVE percpu value and detect there are
1604 * possibility of race condition. If there is, we take a lock.
1607 static void mem_cgroup_update_file_stat(struct page
*page
, int idx
, int val
)
1609 struct mem_cgroup
*mem
;
1610 struct page_cgroup
*pc
= lookup_page_cgroup(page
);
1611 bool need_unlock
= false;
1617 mem
= pc
->mem_cgroup
;
1618 if (unlikely(!mem
|| !PageCgroupUsed(pc
)))
1620 /* pc->mem_cgroup is unstable ? */
1621 if (unlikely(mem_cgroup_stealed(mem
))) {
1622 /* take a lock against to access pc->mem_cgroup */
1623 lock_page_cgroup(pc
);
1625 mem
= pc
->mem_cgroup
;
1626 if (!mem
|| !PageCgroupUsed(pc
))
1630 this_cpu_add(mem
->stat
->count
[idx
], val
);
1633 case MEM_CGROUP_STAT_FILE_MAPPED
:
1635 SetPageCgroupFileMapped(pc
);
1636 else if (!page_mapped(page
))
1637 ClearPageCgroupFileMapped(pc
);
1644 if (unlikely(need_unlock
))
1645 unlock_page_cgroup(pc
);
1650 void mem_cgroup_update_file_mapped(struct page
*page
, int val
)
1652 mem_cgroup_update_file_stat(page
, MEM_CGROUP_STAT_FILE_MAPPED
, val
);
1656 * size of first charge trial. "32" comes from vmscan.c's magic value.
1657 * TODO: maybe necessary to use big numbers in big irons.
1659 #define CHARGE_SIZE (32 * PAGE_SIZE)
1660 struct memcg_stock_pcp
{
1661 struct mem_cgroup
*cached
; /* this never be root cgroup */
1663 struct work_struct work
;
1665 static DEFINE_PER_CPU(struct memcg_stock_pcp
, memcg_stock
);
1666 static atomic_t memcg_drain_count
;
1669 * Try to consume stocked charge on this cpu. If success, PAGE_SIZE is consumed
1670 * from local stock and true is returned. If the stock is 0 or charges from a
1671 * cgroup which is not current target, returns false. This stock will be
1674 static bool consume_stock(struct mem_cgroup
*mem
)
1676 struct memcg_stock_pcp
*stock
;
1679 stock
= &get_cpu_var(memcg_stock
);
1680 if (mem
== stock
->cached
&& stock
->charge
)
1681 stock
->charge
-= PAGE_SIZE
;
1682 else /* need to call res_counter_charge */
1684 put_cpu_var(memcg_stock
);
1689 * Returns stocks cached in percpu to res_counter and reset cached information.
1691 static void drain_stock(struct memcg_stock_pcp
*stock
)
1693 struct mem_cgroup
*old
= stock
->cached
;
1695 if (stock
->charge
) {
1696 res_counter_uncharge(&old
->res
, stock
->charge
);
1697 if (do_swap_account
)
1698 res_counter_uncharge(&old
->memsw
, stock
->charge
);
1700 stock
->cached
= NULL
;
1705 * This must be called under preempt disabled or must be called by
1706 * a thread which is pinned to local cpu.
1708 static void drain_local_stock(struct work_struct
*dummy
)
1710 struct memcg_stock_pcp
*stock
= &__get_cpu_var(memcg_stock
);
1715 * Cache charges(val) which is from res_counter, to local per_cpu area.
1716 * This will be consumed by consume_stock() function, later.
1718 static void refill_stock(struct mem_cgroup
*mem
, int val
)
1720 struct memcg_stock_pcp
*stock
= &get_cpu_var(memcg_stock
);
1722 if (stock
->cached
!= mem
) { /* reset if necessary */
1724 stock
->cached
= mem
;
1726 stock
->charge
+= val
;
1727 put_cpu_var(memcg_stock
);
1731 * Tries to drain stocked charges in other cpus. This function is asynchronous
1732 * and just put a work per cpu for draining localy on each cpu. Caller can
1733 * expects some charges will be back to res_counter later but cannot wait for
1736 static void drain_all_stock_async(void)
1739 /* This function is for scheduling "drain" in asynchronous way.
1740 * The result of "drain" is not directly handled by callers. Then,
1741 * if someone is calling drain, we don't have to call drain more.
1742 * Anyway, WORK_STRUCT_PENDING check in queue_work_on() will catch if
1743 * there is a race. We just do loose check here.
1745 if (atomic_read(&memcg_drain_count
))
1747 /* Notify other cpus that system-wide "drain" is running */
1748 atomic_inc(&memcg_drain_count
);
1750 for_each_online_cpu(cpu
) {
1751 struct memcg_stock_pcp
*stock
= &per_cpu(memcg_stock
, cpu
);
1752 schedule_work_on(cpu
, &stock
->work
);
1755 atomic_dec(&memcg_drain_count
);
1756 /* We don't wait for flush_work */
1759 /* This is a synchronous drain interface. */
1760 static void drain_all_stock_sync(void)
1762 /* called when force_empty is called */
1763 atomic_inc(&memcg_drain_count
);
1764 schedule_on_each_cpu(drain_local_stock
);
1765 atomic_dec(&memcg_drain_count
);
1769 * This function drains percpu counter value from DEAD cpu and
1770 * move it to local cpu. Note that this function can be preempted.
1772 static void mem_cgroup_drain_pcp_counter(struct mem_cgroup
*mem
, int cpu
)
1776 spin_lock(&mem
->pcp_counter_lock
);
1777 for (i
= 0; i
< MEM_CGROUP_STAT_DATA
; i
++) {
1778 s64 x
= per_cpu(mem
->stat
->count
[i
], cpu
);
1780 per_cpu(mem
->stat
->count
[i
], cpu
) = 0;
1781 mem
->nocpu_base
.count
[i
] += x
;
1783 /* need to clear ON_MOVE value, works as a kind of lock. */
1784 per_cpu(mem
->stat
->count
[MEM_CGROUP_ON_MOVE
], cpu
) = 0;
1785 spin_unlock(&mem
->pcp_counter_lock
);
1788 static void synchronize_mem_cgroup_on_move(struct mem_cgroup
*mem
, int cpu
)
1790 int idx
= MEM_CGROUP_ON_MOVE
;
1792 spin_lock(&mem
->pcp_counter_lock
);
1793 per_cpu(mem
->stat
->count
[idx
], cpu
) = mem
->nocpu_base
.count
[idx
];
1794 spin_unlock(&mem
->pcp_counter_lock
);
1797 static int __cpuinit
memcg_cpu_hotplug_callback(struct notifier_block
*nb
,
1798 unsigned long action
,
1801 int cpu
= (unsigned long)hcpu
;
1802 struct memcg_stock_pcp
*stock
;
1803 struct mem_cgroup
*iter
;
1805 if ((action
== CPU_ONLINE
)) {
1806 for_each_mem_cgroup_all(iter
)
1807 synchronize_mem_cgroup_on_move(iter
, cpu
);
1811 if ((action
!= CPU_DEAD
) || action
!= CPU_DEAD_FROZEN
)
1814 for_each_mem_cgroup_all(iter
)
1815 mem_cgroup_drain_pcp_counter(iter
, cpu
);
1817 stock
= &per_cpu(memcg_stock
, cpu
);
1823 /* See __mem_cgroup_try_charge() for details */
1825 CHARGE_OK
, /* success */
1826 CHARGE_RETRY
, /* need to retry but retry is not bad */
1827 CHARGE_NOMEM
, /* we can't do more. return -ENOMEM */
1828 CHARGE_WOULDBLOCK
, /* GFP_WAIT wasn't set and no enough res. */
1829 CHARGE_OOM_DIE
, /* the current is killed because of OOM */
1832 static int __mem_cgroup_do_charge(struct mem_cgroup
*mem
, gfp_t gfp_mask
,
1833 int csize
, bool oom_check
)
1835 struct mem_cgroup
*mem_over_limit
;
1836 struct res_counter
*fail_res
;
1837 unsigned long flags
= 0;
1840 ret
= res_counter_charge(&mem
->res
, csize
, &fail_res
);
1843 if (!do_swap_account
)
1845 ret
= res_counter_charge(&mem
->memsw
, csize
, &fail_res
);
1849 mem_over_limit
= mem_cgroup_from_res_counter(fail_res
, memsw
);
1850 flags
|= MEM_CGROUP_RECLAIM_NOSWAP
;
1852 mem_over_limit
= mem_cgroup_from_res_counter(fail_res
, res
);
1854 if (csize
> PAGE_SIZE
) /* change csize and retry */
1855 return CHARGE_RETRY
;
1857 if (!(gfp_mask
& __GFP_WAIT
))
1858 return CHARGE_WOULDBLOCK
;
1860 ret
= mem_cgroup_hierarchical_reclaim(mem_over_limit
, NULL
,
1863 * try_to_free_mem_cgroup_pages() might not give us a full
1864 * picture of reclaim. Some pages are reclaimed and might be
1865 * moved to swap cache or just unmapped from the cgroup.
1866 * Check the limit again to see if the reclaim reduced the
1867 * current usage of the cgroup before giving up
1869 if (ret
|| mem_cgroup_check_under_limit(mem_over_limit
))
1870 return CHARGE_RETRY
;
1873 * At task move, charge accounts can be doubly counted. So, it's
1874 * better to wait until the end of task_move if something is going on.
1876 if (mem_cgroup_wait_acct_move(mem_over_limit
))
1877 return CHARGE_RETRY
;
1879 /* If we don't need to call oom-killer at el, return immediately */
1881 return CHARGE_NOMEM
;
1883 if (!mem_cgroup_handle_oom(mem_over_limit
, gfp_mask
))
1884 return CHARGE_OOM_DIE
;
1886 return CHARGE_RETRY
;
1890 * Unlike exported interface, "oom" parameter is added. if oom==true,
1891 * oom-killer can be invoked.
1893 static int __mem_cgroup_try_charge(struct mm_struct
*mm
,
1895 struct mem_cgroup
**memcg
, bool oom
,
1898 int nr_oom_retries
= MEM_CGROUP_RECLAIM_RETRIES
;
1899 struct mem_cgroup
*mem
= NULL
;
1901 int csize
= max(CHARGE_SIZE
, (unsigned long) page_size
);
1904 * Unlike gloval-vm's OOM-kill, we're not in memory shortage
1905 * in system level. So, allow to go ahead dying process in addition to
1908 if (unlikely(test_thread_flag(TIF_MEMDIE
)
1909 || fatal_signal_pending(current
)))
1913 * We always charge the cgroup the mm_struct belongs to.
1914 * The mm_struct's mem_cgroup changes on task migration if the
1915 * thread group leader migrates. It's possible that mm is not
1916 * set, if so charge the init_mm (happens for pagecache usage).
1921 if (*memcg
) { /* css should be a valid one */
1923 VM_BUG_ON(css_is_removed(&mem
->css
));
1924 if (mem_cgroup_is_root(mem
))
1926 if (page_size
== PAGE_SIZE
&& consume_stock(mem
))
1930 struct task_struct
*p
;
1933 p
= rcu_dereference(mm
->owner
);
1935 * Because we don't have task_lock(), "p" can exit.
1936 * In that case, "mem" can point to root or p can be NULL with
1937 * race with swapoff. Then, we have small risk of mis-accouning.
1938 * But such kind of mis-account by race always happens because
1939 * we don't have cgroup_mutex(). It's overkill and we allo that
1941 * (*) swapoff at el will charge against mm-struct not against
1942 * task-struct. So, mm->owner can be NULL.
1944 mem
= mem_cgroup_from_task(p
);
1945 if (!mem
|| mem_cgroup_is_root(mem
)) {
1949 if (page_size
== PAGE_SIZE
&& consume_stock(mem
)) {
1951 * It seems dagerous to access memcg without css_get().
1952 * But considering how consume_stok works, it's not
1953 * necessary. If consume_stock success, some charges
1954 * from this memcg are cached on this cpu. So, we
1955 * don't need to call css_get()/css_tryget() before
1956 * calling consume_stock().
1961 /* after here, we may be blocked. we need to get refcnt */
1962 if (!css_tryget(&mem
->css
)) {
1972 /* If killed, bypass charge */
1973 if (fatal_signal_pending(current
)) {
1979 if (oom
&& !nr_oom_retries
) {
1981 nr_oom_retries
= MEM_CGROUP_RECLAIM_RETRIES
;
1984 ret
= __mem_cgroup_do_charge(mem
, gfp_mask
, csize
, oom_check
);
1989 case CHARGE_RETRY
: /* not in OOM situation but retry */
1994 case CHARGE_WOULDBLOCK
: /* !__GFP_WAIT */
1997 case CHARGE_NOMEM
: /* OOM routine works */
2002 /* If oom, we never return -ENOMEM */
2005 case CHARGE_OOM_DIE
: /* Killed by OOM Killer */
2009 } while (ret
!= CHARGE_OK
);
2011 if (csize
> page_size
)
2012 refill_stock(mem
, csize
- page_size
);
2026 * Somemtimes we have to undo a charge we got by try_charge().
2027 * This function is for that and do uncharge, put css's refcnt.
2028 * gotten by try_charge().
2030 static void __mem_cgroup_cancel_charge(struct mem_cgroup
*mem
,
2031 unsigned long count
)
2033 if (!mem_cgroup_is_root(mem
)) {
2034 res_counter_uncharge(&mem
->res
, PAGE_SIZE
* count
);
2035 if (do_swap_account
)
2036 res_counter_uncharge(&mem
->memsw
, PAGE_SIZE
* count
);
2040 static void mem_cgroup_cancel_charge(struct mem_cgroup
*mem
,
2043 __mem_cgroup_cancel_charge(mem
, page_size
>> PAGE_SHIFT
);
2047 * A helper function to get mem_cgroup from ID. must be called under
2048 * rcu_read_lock(). The caller must check css_is_removed() or some if
2049 * it's concern. (dropping refcnt from swap can be called against removed
2052 static struct mem_cgroup
*mem_cgroup_lookup(unsigned short id
)
2054 struct cgroup_subsys_state
*css
;
2056 /* ID 0 is unused ID */
2059 css
= css_lookup(&mem_cgroup_subsys
, id
);
2062 return container_of(css
, struct mem_cgroup
, css
);
2065 struct mem_cgroup
*try_get_mem_cgroup_from_page(struct page
*page
)
2067 struct mem_cgroup
*mem
= NULL
;
2068 struct page_cgroup
*pc
;
2072 VM_BUG_ON(!PageLocked(page
));
2074 pc
= lookup_page_cgroup(page
);
2075 lock_page_cgroup(pc
);
2076 if (PageCgroupUsed(pc
)) {
2077 mem
= pc
->mem_cgroup
;
2078 if (mem
&& !css_tryget(&mem
->css
))
2080 } else if (PageSwapCache(page
)) {
2081 ent
.val
= page_private(page
);
2082 id
= lookup_swap_cgroup(ent
);
2084 mem
= mem_cgroup_lookup(id
);
2085 if (mem
&& !css_tryget(&mem
->css
))
2089 unlock_page_cgroup(pc
);
2094 * commit a charge got by __mem_cgroup_try_charge() and makes page_cgroup to be
2095 * USED state. If already USED, uncharge and return.
2097 static void ____mem_cgroup_commit_charge(struct mem_cgroup
*mem
,
2098 struct page_cgroup
*pc
,
2099 enum charge_type ctype
)
2101 pc
->mem_cgroup
= mem
;
2103 * We access a page_cgroup asynchronously without lock_page_cgroup().
2104 * Especially when a page_cgroup is taken from a page, pc->mem_cgroup
2105 * is accessed after testing USED bit. To make pc->mem_cgroup visible
2106 * before USED bit, we need memory barrier here.
2107 * See mem_cgroup_add_lru_list(), etc.
2111 case MEM_CGROUP_CHARGE_TYPE_CACHE
:
2112 case MEM_CGROUP_CHARGE_TYPE_SHMEM
:
2113 SetPageCgroupCache(pc
);
2114 SetPageCgroupUsed(pc
);
2116 case MEM_CGROUP_CHARGE_TYPE_MAPPED
:
2117 ClearPageCgroupCache(pc
);
2118 SetPageCgroupUsed(pc
);
2124 mem_cgroup_charge_statistics(mem
, pc
, true);
2127 static void __mem_cgroup_commit_charge(struct mem_cgroup
*mem
,
2128 struct page_cgroup
*pc
,
2129 enum charge_type ctype
,
2133 int count
= page_size
>> PAGE_SHIFT
;
2135 /* try_charge() can return NULL to *memcg, taking care of it. */
2139 lock_page_cgroup(pc
);
2140 if (unlikely(PageCgroupUsed(pc
))) {
2141 unlock_page_cgroup(pc
);
2142 mem_cgroup_cancel_charge(mem
, page_size
);
2147 * we don't need page_cgroup_lock about tail pages, becase they are not
2148 * accessed by any other context at this point.
2150 for (i
= 0; i
< count
; i
++)
2151 ____mem_cgroup_commit_charge(mem
, pc
+ i
, ctype
);
2153 unlock_page_cgroup(pc
);
2155 * "charge_statistics" updated event counter. Then, check it.
2156 * Insert ancestor (and ancestor's ancestors), to softlimit RB-tree.
2157 * if they exceeds softlimit.
2159 memcg_check_events(mem
, pc
->page
);
2163 * __mem_cgroup_move_account - move account of the page
2164 * @pc: page_cgroup of the page.
2165 * @from: mem_cgroup which the page is moved from.
2166 * @to: mem_cgroup which the page is moved to. @from != @to.
2167 * @uncharge: whether we should call uncharge and css_put against @from.
2169 * The caller must confirm following.
2170 * - page is not on LRU (isolate_page() is useful.)
2171 * - the pc is locked, used, and ->mem_cgroup points to @from.
2173 * This function doesn't do "charge" nor css_get to new cgroup. It should be
2174 * done by a caller(__mem_cgroup_try_charge would be usefull). If @uncharge is
2175 * true, this function does "uncharge" from old cgroup, but it doesn't if
2176 * @uncharge is false, so a caller should do "uncharge".
2179 static void __mem_cgroup_move_account(struct page_cgroup
*pc
,
2180 struct mem_cgroup
*from
, struct mem_cgroup
*to
, bool uncharge
)
2182 VM_BUG_ON(from
== to
);
2183 VM_BUG_ON(PageLRU(pc
->page
));
2184 VM_BUG_ON(!page_is_cgroup_locked(pc
));
2185 VM_BUG_ON(!PageCgroupUsed(pc
));
2186 VM_BUG_ON(pc
->mem_cgroup
!= from
);
2188 if (PageCgroupFileMapped(pc
)) {
2189 /* Update mapped_file data for mem_cgroup */
2191 __this_cpu_dec(from
->stat
->count
[MEM_CGROUP_STAT_FILE_MAPPED
]);
2192 __this_cpu_inc(to
->stat
->count
[MEM_CGROUP_STAT_FILE_MAPPED
]);
2195 mem_cgroup_charge_statistics(from
, pc
, false);
2197 /* This is not "cancel", but cancel_charge does all we need. */
2198 mem_cgroup_cancel_charge(from
, PAGE_SIZE
);
2200 /* caller should have done css_get */
2201 pc
->mem_cgroup
= to
;
2202 mem_cgroup_charge_statistics(to
, pc
, true);
2204 * We charges against "to" which may not have any tasks. Then, "to"
2205 * can be under rmdir(). But in current implementation, caller of
2206 * this function is just force_empty() and move charge, so it's
2207 * garanteed that "to" is never removed. So, we don't check rmdir
2213 * check whether the @pc is valid for moving account and call
2214 * __mem_cgroup_move_account()
2216 static int mem_cgroup_move_account(struct page_cgroup
*pc
,
2217 struct mem_cgroup
*from
, struct mem_cgroup
*to
, bool uncharge
)
2220 lock_page_cgroup(pc
);
2221 if (PageCgroupUsed(pc
) && pc
->mem_cgroup
== from
) {
2222 __mem_cgroup_move_account(pc
, from
, to
, uncharge
);
2225 unlock_page_cgroup(pc
);
2229 memcg_check_events(to
, pc
->page
);
2230 memcg_check_events(from
, pc
->page
);
2235 * move charges to its parent.
2238 static int mem_cgroup_move_parent(struct page_cgroup
*pc
,
2239 struct mem_cgroup
*child
,
2242 struct page
*page
= pc
->page
;
2243 struct cgroup
*cg
= child
->css
.cgroup
;
2244 struct cgroup
*pcg
= cg
->parent
;
2245 struct mem_cgroup
*parent
;
2253 if (!get_page_unless_zero(page
))
2255 if (isolate_lru_page(page
))
2258 parent
= mem_cgroup_from_cont(pcg
);
2259 ret
= __mem_cgroup_try_charge(NULL
, gfp_mask
, &parent
, false,
2264 ret
= mem_cgroup_move_account(pc
, child
, parent
, true);
2266 mem_cgroup_cancel_charge(parent
, PAGE_SIZE
);
2268 putback_lru_page(page
);
2276 * Charge the memory controller for page usage.
2278 * 0 if the charge was successful
2279 * < 0 if the cgroup is over its limit
2281 static int mem_cgroup_charge_common(struct page
*page
, struct mm_struct
*mm
,
2282 gfp_t gfp_mask
, enum charge_type ctype
)
2284 struct mem_cgroup
*mem
= NULL
;
2285 struct page_cgroup
*pc
;
2287 int page_size
= PAGE_SIZE
;
2289 if (PageTransHuge(page
))
2290 page_size
<<= compound_order(page
);
2292 pc
= lookup_page_cgroup(page
);
2293 /* can happen at boot */
2298 ret
= __mem_cgroup_try_charge(mm
, gfp_mask
, &mem
, true, page_size
);
2302 __mem_cgroup_commit_charge(mem
, pc
, ctype
, page_size
);
2306 int mem_cgroup_newpage_charge(struct page
*page
,
2307 struct mm_struct
*mm
, gfp_t gfp_mask
)
2309 if (mem_cgroup_disabled())
2312 * If already mapped, we don't have to account.
2313 * If page cache, page->mapping has address_space.
2314 * But page->mapping may have out-of-use anon_vma pointer,
2315 * detecit it by PageAnon() check. newly-mapped-anon's page->mapping
2318 if (page_mapped(page
) || (page
->mapping
&& !PageAnon(page
)))
2322 return mem_cgroup_charge_common(page
, mm
, gfp_mask
,
2323 MEM_CGROUP_CHARGE_TYPE_MAPPED
);
2327 __mem_cgroup_commit_charge_swapin(struct page
*page
, struct mem_cgroup
*ptr
,
2328 enum charge_type ctype
);
2330 int mem_cgroup_cache_charge(struct page
*page
, struct mm_struct
*mm
,
2335 if (mem_cgroup_disabled())
2337 if (PageCompound(page
))
2340 * Corner case handling. This is called from add_to_page_cache()
2341 * in usual. But some FS (shmem) precharges this page before calling it
2342 * and call add_to_page_cache() with GFP_NOWAIT.
2344 * For GFP_NOWAIT case, the page may be pre-charged before calling
2345 * add_to_page_cache(). (See shmem.c) check it here and avoid to call
2346 * charge twice. (It works but has to pay a bit larger cost.)
2347 * And when the page is SwapCache, it should take swap information
2348 * into account. This is under lock_page() now.
2350 if (!(gfp_mask
& __GFP_WAIT
)) {
2351 struct page_cgroup
*pc
;
2353 pc
= lookup_page_cgroup(page
);
2356 lock_page_cgroup(pc
);
2357 if (PageCgroupUsed(pc
)) {
2358 unlock_page_cgroup(pc
);
2361 unlock_page_cgroup(pc
);
2367 if (page_is_file_cache(page
))
2368 return mem_cgroup_charge_common(page
, mm
, gfp_mask
,
2369 MEM_CGROUP_CHARGE_TYPE_CACHE
);
2372 if (PageSwapCache(page
)) {
2373 struct mem_cgroup
*mem
= NULL
;
2375 ret
= mem_cgroup_try_charge_swapin(mm
, page
, gfp_mask
, &mem
);
2377 __mem_cgroup_commit_charge_swapin(page
, mem
,
2378 MEM_CGROUP_CHARGE_TYPE_SHMEM
);
2380 ret
= mem_cgroup_charge_common(page
, mm
, gfp_mask
,
2381 MEM_CGROUP_CHARGE_TYPE_SHMEM
);
2387 * While swap-in, try_charge -> commit or cancel, the page is locked.
2388 * And when try_charge() successfully returns, one refcnt to memcg without
2389 * struct page_cgroup is acquired. This refcnt will be consumed by
2390 * "commit()" or removed by "cancel()"
2392 int mem_cgroup_try_charge_swapin(struct mm_struct
*mm
,
2394 gfp_t mask
, struct mem_cgroup
**ptr
)
2396 struct mem_cgroup
*mem
;
2399 if (mem_cgroup_disabled())
2402 if (!do_swap_account
)
2405 * A racing thread's fault, or swapoff, may have already updated
2406 * the pte, and even removed page from swap cache: in those cases
2407 * do_swap_page()'s pte_same() test will fail; but there's also a
2408 * KSM case which does need to charge the page.
2410 if (!PageSwapCache(page
))
2412 mem
= try_get_mem_cgroup_from_page(page
);
2416 ret
= __mem_cgroup_try_charge(NULL
, mask
, ptr
, true, PAGE_SIZE
);
2422 return __mem_cgroup_try_charge(mm
, mask
, ptr
, true, PAGE_SIZE
);
2426 __mem_cgroup_commit_charge_swapin(struct page
*page
, struct mem_cgroup
*ptr
,
2427 enum charge_type ctype
)
2429 struct page_cgroup
*pc
;
2431 if (mem_cgroup_disabled())
2435 cgroup_exclude_rmdir(&ptr
->css
);
2436 pc
= lookup_page_cgroup(page
);
2437 mem_cgroup_lru_del_before_commit_swapcache(page
);
2438 __mem_cgroup_commit_charge(ptr
, pc
, ctype
, PAGE_SIZE
);
2439 mem_cgroup_lru_add_after_commit_swapcache(page
);
2441 * Now swap is on-memory. This means this page may be
2442 * counted both as mem and swap....double count.
2443 * Fix it by uncharging from memsw. Basically, this SwapCache is stable
2444 * under lock_page(). But in do_swap_page()::memory.c, reuse_swap_page()
2445 * may call delete_from_swap_cache() before reach here.
2447 if (do_swap_account
&& PageSwapCache(page
)) {
2448 swp_entry_t ent
= {.val
= page_private(page
)};
2450 struct mem_cgroup
*memcg
;
2452 id
= swap_cgroup_record(ent
, 0);
2454 memcg
= mem_cgroup_lookup(id
);
2457 * This recorded memcg can be obsolete one. So, avoid
2458 * calling css_tryget
2460 if (!mem_cgroup_is_root(memcg
))
2461 res_counter_uncharge(&memcg
->memsw
, PAGE_SIZE
);
2462 mem_cgroup_swap_statistics(memcg
, false);
2463 mem_cgroup_put(memcg
);
2468 * At swapin, we may charge account against cgroup which has no tasks.
2469 * So, rmdir()->pre_destroy() can be called while we do this charge.
2470 * In that case, we need to call pre_destroy() again. check it here.
2472 cgroup_release_and_wakeup_rmdir(&ptr
->css
);
2475 void mem_cgroup_commit_charge_swapin(struct page
*page
, struct mem_cgroup
*ptr
)
2477 __mem_cgroup_commit_charge_swapin(page
, ptr
,
2478 MEM_CGROUP_CHARGE_TYPE_MAPPED
);
2481 void mem_cgroup_cancel_charge_swapin(struct mem_cgroup
*mem
)
2483 if (mem_cgroup_disabled())
2487 mem_cgroup_cancel_charge(mem
, PAGE_SIZE
);
2491 __do_uncharge(struct mem_cgroup
*mem
, const enum charge_type ctype
,
2494 struct memcg_batch_info
*batch
= NULL
;
2495 bool uncharge_memsw
= true;
2496 /* If swapout, usage of swap doesn't decrease */
2497 if (!do_swap_account
|| ctype
== MEM_CGROUP_CHARGE_TYPE_SWAPOUT
)
2498 uncharge_memsw
= false;
2500 batch
= ¤t
->memcg_batch
;
2502 * In usual, we do css_get() when we remember memcg pointer.
2503 * But in this case, we keep res->usage until end of a series of
2504 * uncharges. Then, it's ok to ignore memcg's refcnt.
2509 * do_batch > 0 when unmapping pages or inode invalidate/truncate.
2510 * In those cases, all pages freed continously can be expected to be in
2511 * the same cgroup and we have chance to coalesce uncharges.
2512 * But we do uncharge one by one if this is killed by OOM(TIF_MEMDIE)
2513 * because we want to do uncharge as soon as possible.
2516 if (!batch
->do_batch
|| test_thread_flag(TIF_MEMDIE
))
2517 goto direct_uncharge
;
2519 if (page_size
!= PAGE_SIZE
)
2520 goto direct_uncharge
;
2523 * In typical case, batch->memcg == mem. This means we can
2524 * merge a series of uncharges to an uncharge of res_counter.
2525 * If not, we uncharge res_counter ony by one.
2527 if (batch
->memcg
!= mem
)
2528 goto direct_uncharge
;
2529 /* remember freed charge and uncharge it later */
2530 batch
->bytes
+= PAGE_SIZE
;
2532 batch
->memsw_bytes
+= PAGE_SIZE
;
2535 res_counter_uncharge(&mem
->res
, page_size
);
2537 res_counter_uncharge(&mem
->memsw
, page_size
);
2538 if (unlikely(batch
->memcg
!= mem
))
2539 memcg_oom_recover(mem
);
2544 * uncharge if !page_mapped(page)
2546 static struct mem_cgroup
*
2547 __mem_cgroup_uncharge_common(struct page
*page
, enum charge_type ctype
)
2551 struct page_cgroup
*pc
;
2552 struct mem_cgroup
*mem
= NULL
;
2553 int page_size
= PAGE_SIZE
;
2555 if (mem_cgroup_disabled())
2558 if (PageSwapCache(page
))
2561 if (PageTransHuge(page
))
2562 page_size
<<= compound_order(page
);
2564 count
= page_size
>> PAGE_SHIFT
;
2566 * Check if our page_cgroup is valid
2568 pc
= lookup_page_cgroup(page
);
2569 if (unlikely(!pc
|| !PageCgroupUsed(pc
)))
2572 lock_page_cgroup(pc
);
2574 mem
= pc
->mem_cgroup
;
2576 if (!PageCgroupUsed(pc
))
2580 case MEM_CGROUP_CHARGE_TYPE_MAPPED
:
2581 case MEM_CGROUP_CHARGE_TYPE_DROP
:
2582 /* See mem_cgroup_prepare_migration() */
2583 if (page_mapped(page
) || PageCgroupMigration(pc
))
2586 case MEM_CGROUP_CHARGE_TYPE_SWAPOUT
:
2587 if (!PageAnon(page
)) { /* Shared memory */
2588 if (page
->mapping
&& !page_is_file_cache(page
))
2590 } else if (page_mapped(page
)) /* Anon */
2597 for (i
= 0; i
< count
; i
++)
2598 mem_cgroup_charge_statistics(mem
, pc
+ i
, false);
2600 ClearPageCgroupUsed(pc
);
2602 * pc->mem_cgroup is not cleared here. It will be accessed when it's
2603 * freed from LRU. This is safe because uncharged page is expected not
2604 * to be reused (freed soon). Exception is SwapCache, it's handled by
2605 * special functions.
2608 unlock_page_cgroup(pc
);
2610 * even after unlock, we have mem->res.usage here and this memcg
2611 * will never be freed.
2613 memcg_check_events(mem
, page
);
2614 if (do_swap_account
&& ctype
== MEM_CGROUP_CHARGE_TYPE_SWAPOUT
) {
2615 mem_cgroup_swap_statistics(mem
, true);
2616 mem_cgroup_get(mem
);
2618 if (!mem_cgroup_is_root(mem
))
2619 __do_uncharge(mem
, ctype
, page_size
);
2624 unlock_page_cgroup(pc
);
2628 void mem_cgroup_uncharge_page(struct page
*page
)
2631 if (page_mapped(page
))
2633 if (page
->mapping
&& !PageAnon(page
))
2635 __mem_cgroup_uncharge_common(page
, MEM_CGROUP_CHARGE_TYPE_MAPPED
);
2638 void mem_cgroup_uncharge_cache_page(struct page
*page
)
2640 VM_BUG_ON(page_mapped(page
));
2641 VM_BUG_ON(page
->mapping
);
2642 __mem_cgroup_uncharge_common(page
, MEM_CGROUP_CHARGE_TYPE_CACHE
);
2646 * Batch_start/batch_end is called in unmap_page_range/invlidate/trucate.
2647 * In that cases, pages are freed continuously and we can expect pages
2648 * are in the same memcg. All these calls itself limits the number of
2649 * pages freed at once, then uncharge_start/end() is called properly.
2650 * This may be called prural(2) times in a context,
2653 void mem_cgroup_uncharge_start(void)
2655 current
->memcg_batch
.do_batch
++;
2656 /* We can do nest. */
2657 if (current
->memcg_batch
.do_batch
== 1) {
2658 current
->memcg_batch
.memcg
= NULL
;
2659 current
->memcg_batch
.bytes
= 0;
2660 current
->memcg_batch
.memsw_bytes
= 0;
2664 void mem_cgroup_uncharge_end(void)
2666 struct memcg_batch_info
*batch
= ¤t
->memcg_batch
;
2668 if (!batch
->do_batch
)
2672 if (batch
->do_batch
) /* If stacked, do nothing. */
2678 * This "batch->memcg" is valid without any css_get/put etc...
2679 * bacause we hide charges behind us.
2682 res_counter_uncharge(&batch
->memcg
->res
, batch
->bytes
);
2683 if (batch
->memsw_bytes
)
2684 res_counter_uncharge(&batch
->memcg
->memsw
, batch
->memsw_bytes
);
2685 memcg_oom_recover(batch
->memcg
);
2686 /* forget this pointer (for sanity check) */
2687 batch
->memcg
= NULL
;
2692 * called after __delete_from_swap_cache() and drop "page" account.
2693 * memcg information is recorded to swap_cgroup of "ent"
2696 mem_cgroup_uncharge_swapcache(struct page
*page
, swp_entry_t ent
, bool swapout
)
2698 struct mem_cgroup
*memcg
;
2699 int ctype
= MEM_CGROUP_CHARGE_TYPE_SWAPOUT
;
2701 if (!swapout
) /* this was a swap cache but the swap is unused ! */
2702 ctype
= MEM_CGROUP_CHARGE_TYPE_DROP
;
2704 memcg
= __mem_cgroup_uncharge_common(page
, ctype
);
2707 * record memcg information, if swapout && memcg != NULL,
2708 * mem_cgroup_get() was called in uncharge().
2710 if (do_swap_account
&& swapout
&& memcg
)
2711 swap_cgroup_record(ent
, css_id(&memcg
->css
));
2715 #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP
2717 * called from swap_entry_free(). remove record in swap_cgroup and
2718 * uncharge "memsw" account.
2720 void mem_cgroup_uncharge_swap(swp_entry_t ent
)
2722 struct mem_cgroup
*memcg
;
2725 if (!do_swap_account
)
2728 id
= swap_cgroup_record(ent
, 0);
2730 memcg
= mem_cgroup_lookup(id
);
2733 * We uncharge this because swap is freed.
2734 * This memcg can be obsolete one. We avoid calling css_tryget
2736 if (!mem_cgroup_is_root(memcg
))
2737 res_counter_uncharge(&memcg
->memsw
, PAGE_SIZE
);
2738 mem_cgroup_swap_statistics(memcg
, false);
2739 mem_cgroup_put(memcg
);
2745 * mem_cgroup_move_swap_account - move swap charge and swap_cgroup's record.
2746 * @entry: swap entry to be moved
2747 * @from: mem_cgroup which the entry is moved from
2748 * @to: mem_cgroup which the entry is moved to
2749 * @need_fixup: whether we should fixup res_counters and refcounts.
2751 * It succeeds only when the swap_cgroup's record for this entry is the same
2752 * as the mem_cgroup's id of @from.
2754 * Returns 0 on success, -EINVAL on failure.
2756 * The caller must have charged to @to, IOW, called res_counter_charge() about
2757 * both res and memsw, and called css_get().
2759 static int mem_cgroup_move_swap_account(swp_entry_t entry
,
2760 struct mem_cgroup
*from
, struct mem_cgroup
*to
, bool need_fixup
)
2762 unsigned short old_id
, new_id
;
2764 old_id
= css_id(&from
->css
);
2765 new_id
= css_id(&to
->css
);
2767 if (swap_cgroup_cmpxchg(entry
, old_id
, new_id
) == old_id
) {
2768 mem_cgroup_swap_statistics(from
, false);
2769 mem_cgroup_swap_statistics(to
, true);
2771 * This function is only called from task migration context now.
2772 * It postpones res_counter and refcount handling till the end
2773 * of task migration(mem_cgroup_clear_mc()) for performance
2774 * improvement. But we cannot postpone mem_cgroup_get(to)
2775 * because if the process that has been moved to @to does
2776 * swap-in, the refcount of @to might be decreased to 0.
2780 if (!mem_cgroup_is_root(from
))
2781 res_counter_uncharge(&from
->memsw
, PAGE_SIZE
);
2782 mem_cgroup_put(from
);
2784 * we charged both to->res and to->memsw, so we should
2787 if (!mem_cgroup_is_root(to
))
2788 res_counter_uncharge(&to
->res
, PAGE_SIZE
);
2795 static inline int mem_cgroup_move_swap_account(swp_entry_t entry
,
2796 struct mem_cgroup
*from
, struct mem_cgroup
*to
, bool need_fixup
)
2803 * Before starting migration, account PAGE_SIZE to mem_cgroup that the old
2806 int mem_cgroup_prepare_migration(struct page
*page
,
2807 struct page
*newpage
, struct mem_cgroup
**ptr
)
2809 struct page_cgroup
*pc
;
2810 struct mem_cgroup
*mem
= NULL
;
2811 enum charge_type ctype
;
2814 VM_BUG_ON(PageTransHuge(page
));
2815 if (mem_cgroup_disabled())
2818 pc
= lookup_page_cgroup(page
);
2819 lock_page_cgroup(pc
);
2820 if (PageCgroupUsed(pc
)) {
2821 mem
= pc
->mem_cgroup
;
2824 * At migrating an anonymous page, its mapcount goes down
2825 * to 0 and uncharge() will be called. But, even if it's fully
2826 * unmapped, migration may fail and this page has to be
2827 * charged again. We set MIGRATION flag here and delay uncharge
2828 * until end_migration() is called
2830 * Corner Case Thinking
2832 * When the old page was mapped as Anon and it's unmap-and-freed
2833 * while migration was ongoing.
2834 * If unmap finds the old page, uncharge() of it will be delayed
2835 * until end_migration(). If unmap finds a new page, it's
2836 * uncharged when it make mapcount to be 1->0. If unmap code
2837 * finds swap_migration_entry, the new page will not be mapped
2838 * and end_migration() will find it(mapcount==0).
2841 * When the old page was mapped but migraion fails, the kernel
2842 * remaps it. A charge for it is kept by MIGRATION flag even
2843 * if mapcount goes down to 0. We can do remap successfully
2844 * without charging it again.
2847 * The "old" page is under lock_page() until the end of
2848 * migration, so, the old page itself will not be swapped-out.
2849 * If the new page is swapped out before end_migraton, our
2850 * hook to usual swap-out path will catch the event.
2853 SetPageCgroupMigration(pc
);
2855 unlock_page_cgroup(pc
);
2857 * If the page is not charged at this point,
2864 ret
= __mem_cgroup_try_charge(NULL
, GFP_KERNEL
, ptr
, false, PAGE_SIZE
);
2865 css_put(&mem
->css
);/* drop extra refcnt */
2866 if (ret
|| *ptr
== NULL
) {
2867 if (PageAnon(page
)) {
2868 lock_page_cgroup(pc
);
2869 ClearPageCgroupMigration(pc
);
2870 unlock_page_cgroup(pc
);
2872 * The old page may be fully unmapped while we kept it.
2874 mem_cgroup_uncharge_page(page
);
2879 * We charge new page before it's used/mapped. So, even if unlock_page()
2880 * is called before end_migration, we can catch all events on this new
2881 * page. In the case new page is migrated but not remapped, new page's
2882 * mapcount will be finally 0 and we call uncharge in end_migration().
2884 pc
= lookup_page_cgroup(newpage
);
2886 ctype
= MEM_CGROUP_CHARGE_TYPE_MAPPED
;
2887 else if (page_is_file_cache(page
))
2888 ctype
= MEM_CGROUP_CHARGE_TYPE_CACHE
;
2890 ctype
= MEM_CGROUP_CHARGE_TYPE_SHMEM
;
2891 __mem_cgroup_commit_charge(mem
, pc
, ctype
, PAGE_SIZE
);
2895 /* remove redundant charge if migration failed*/
2896 void mem_cgroup_end_migration(struct mem_cgroup
*mem
,
2897 struct page
*oldpage
, struct page
*newpage
)
2899 struct page
*used
, *unused
;
2900 struct page_cgroup
*pc
;
2904 /* blocks rmdir() */
2905 cgroup_exclude_rmdir(&mem
->css
);
2906 /* at migration success, oldpage->mapping is NULL. */
2907 if (oldpage
->mapping
) {
2915 * We disallowed uncharge of pages under migration because mapcount
2916 * of the page goes down to zero, temporarly.
2917 * Clear the flag and check the page should be charged.
2919 pc
= lookup_page_cgroup(oldpage
);
2920 lock_page_cgroup(pc
);
2921 ClearPageCgroupMigration(pc
);
2922 unlock_page_cgroup(pc
);
2924 __mem_cgroup_uncharge_common(unused
, MEM_CGROUP_CHARGE_TYPE_FORCE
);
2927 * If a page is a file cache, radix-tree replacement is very atomic
2928 * and we can skip this check. When it was an Anon page, its mapcount
2929 * goes down to 0. But because we added MIGRATION flage, it's not
2930 * uncharged yet. There are several case but page->mapcount check
2931 * and USED bit check in mem_cgroup_uncharge_page() will do enough
2932 * check. (see prepare_charge() also)
2935 mem_cgroup_uncharge_page(used
);
2937 * At migration, we may charge account against cgroup which has no
2939 * So, rmdir()->pre_destroy() can be called while we do this charge.
2940 * In that case, we need to call pre_destroy() again. check it here.
2942 cgroup_release_and_wakeup_rmdir(&mem
->css
);
2946 * A call to try to shrink memory usage on charge failure at shmem's swapin.
2947 * Calling hierarchical_reclaim is not enough because we should update
2948 * last_oom_jiffies to prevent pagefault_out_of_memory from invoking global OOM.
2949 * Moreover considering hierarchy, we should reclaim from the mem_over_limit,
2950 * not from the memcg which this page would be charged to.
2951 * try_charge_swapin does all of these works properly.
2953 int mem_cgroup_shmem_charge_fallback(struct page
*page
,
2954 struct mm_struct
*mm
,
2957 struct mem_cgroup
*mem
= NULL
;
2960 if (mem_cgroup_disabled())
2963 ret
= mem_cgroup_try_charge_swapin(mm
, page
, gfp_mask
, &mem
);
2965 mem_cgroup_cancel_charge_swapin(mem
); /* it does !mem check */
2970 static DEFINE_MUTEX(set_limit_mutex
);
2972 static int mem_cgroup_resize_limit(struct mem_cgroup
*memcg
,
2973 unsigned long long val
)
2976 u64 memswlimit
, memlimit
;
2978 int children
= mem_cgroup_count_children(memcg
);
2979 u64 curusage
, oldusage
;
2983 * For keeping hierarchical_reclaim simple, how long we should retry
2984 * is depends on callers. We set our retry-count to be function
2985 * of # of children which we should visit in this loop.
2987 retry_count
= MEM_CGROUP_RECLAIM_RETRIES
* children
;
2989 oldusage
= res_counter_read_u64(&memcg
->res
, RES_USAGE
);
2992 while (retry_count
) {
2993 if (signal_pending(current
)) {
2998 * Rather than hide all in some function, I do this in
2999 * open coded manner. You see what this really does.
3000 * We have to guarantee mem->res.limit < mem->memsw.limit.
3002 mutex_lock(&set_limit_mutex
);
3003 memswlimit
= res_counter_read_u64(&memcg
->memsw
, RES_LIMIT
);
3004 if (memswlimit
< val
) {
3006 mutex_unlock(&set_limit_mutex
);
3010 memlimit
= res_counter_read_u64(&memcg
->res
, RES_LIMIT
);
3014 ret
= res_counter_set_limit(&memcg
->res
, val
);
3016 if (memswlimit
== val
)
3017 memcg
->memsw_is_minimum
= true;
3019 memcg
->memsw_is_minimum
= false;
3021 mutex_unlock(&set_limit_mutex
);
3026 mem_cgroup_hierarchical_reclaim(memcg
, NULL
, GFP_KERNEL
,
3027 MEM_CGROUP_RECLAIM_SHRINK
);
3028 curusage
= res_counter_read_u64(&memcg
->res
, RES_USAGE
);
3029 /* Usage is reduced ? */
3030 if (curusage
>= oldusage
)
3033 oldusage
= curusage
;
3035 if (!ret
&& enlarge
)
3036 memcg_oom_recover(memcg
);
3041 static int mem_cgroup_resize_memsw_limit(struct mem_cgroup
*memcg
,
3042 unsigned long long val
)
3045 u64 memlimit
, memswlimit
, oldusage
, curusage
;
3046 int children
= mem_cgroup_count_children(memcg
);
3050 /* see mem_cgroup_resize_res_limit */
3051 retry_count
= children
* MEM_CGROUP_RECLAIM_RETRIES
;
3052 oldusage
= res_counter_read_u64(&memcg
->memsw
, RES_USAGE
);
3053 while (retry_count
) {
3054 if (signal_pending(current
)) {
3059 * Rather than hide all in some function, I do this in
3060 * open coded manner. You see what this really does.
3061 * We have to guarantee mem->res.limit < mem->memsw.limit.
3063 mutex_lock(&set_limit_mutex
);
3064 memlimit
= res_counter_read_u64(&memcg
->res
, RES_LIMIT
);
3065 if (memlimit
> val
) {
3067 mutex_unlock(&set_limit_mutex
);
3070 memswlimit
= res_counter_read_u64(&memcg
->memsw
, RES_LIMIT
);
3071 if (memswlimit
< val
)
3073 ret
= res_counter_set_limit(&memcg
->memsw
, val
);
3075 if (memlimit
== val
)
3076 memcg
->memsw_is_minimum
= true;
3078 memcg
->memsw_is_minimum
= false;
3080 mutex_unlock(&set_limit_mutex
);
3085 mem_cgroup_hierarchical_reclaim(memcg
, NULL
, GFP_KERNEL
,
3086 MEM_CGROUP_RECLAIM_NOSWAP
|
3087 MEM_CGROUP_RECLAIM_SHRINK
);
3088 curusage
= res_counter_read_u64(&memcg
->memsw
, RES_USAGE
);
3089 /* Usage is reduced ? */
3090 if (curusage
>= oldusage
)
3093 oldusage
= curusage
;
3095 if (!ret
&& enlarge
)
3096 memcg_oom_recover(memcg
);
3100 unsigned long mem_cgroup_soft_limit_reclaim(struct zone
*zone
, int order
,
3103 unsigned long nr_reclaimed
= 0;
3104 struct mem_cgroup_per_zone
*mz
, *next_mz
= NULL
;
3105 unsigned long reclaimed
;
3107 struct mem_cgroup_tree_per_zone
*mctz
;
3108 unsigned long long excess
;
3113 mctz
= soft_limit_tree_node_zone(zone_to_nid(zone
), zone_idx(zone
));
3115 * This loop can run a while, specially if mem_cgroup's continuously
3116 * keep exceeding their soft limit and putting the system under
3123 mz
= mem_cgroup_largest_soft_limit_node(mctz
);
3127 reclaimed
= mem_cgroup_hierarchical_reclaim(mz
->mem
, zone
,
3129 MEM_CGROUP_RECLAIM_SOFT
);
3130 nr_reclaimed
+= reclaimed
;
3131 spin_lock(&mctz
->lock
);
3134 * If we failed to reclaim anything from this memory cgroup
3135 * it is time to move on to the next cgroup
3141 * Loop until we find yet another one.
3143 * By the time we get the soft_limit lock
3144 * again, someone might have aded the
3145 * group back on the RB tree. Iterate to
3146 * make sure we get a different mem.
3147 * mem_cgroup_largest_soft_limit_node returns
3148 * NULL if no other cgroup is present on
3152 __mem_cgroup_largest_soft_limit_node(mctz
);
3153 if (next_mz
== mz
) {
3154 css_put(&next_mz
->mem
->css
);
3156 } else /* next_mz == NULL or other memcg */
3160 __mem_cgroup_remove_exceeded(mz
->mem
, mz
, mctz
);
3161 excess
= res_counter_soft_limit_excess(&mz
->mem
->res
);
3163 * One school of thought says that we should not add
3164 * back the node to the tree if reclaim returns 0.
3165 * But our reclaim could return 0, simply because due
3166 * to priority we are exposing a smaller subset of
3167 * memory to reclaim from. Consider this as a longer
3170 /* If excess == 0, no tree ops */
3171 __mem_cgroup_insert_exceeded(mz
->mem
, mz
, mctz
, excess
);
3172 spin_unlock(&mctz
->lock
);
3173 css_put(&mz
->mem
->css
);
3176 * Could not reclaim anything and there are no more
3177 * mem cgroups to try or we seem to be looping without
3178 * reclaiming anything.
3180 if (!nr_reclaimed
&&
3182 loop
> MEM_CGROUP_MAX_SOFT_LIMIT_RECLAIM_LOOPS
))
3184 } while (!nr_reclaimed
);
3186 css_put(&next_mz
->mem
->css
);
3187 return nr_reclaimed
;
3191 * This routine traverse page_cgroup in given list and drop them all.
3192 * *And* this routine doesn't reclaim page itself, just removes page_cgroup.
3194 static int mem_cgroup_force_empty_list(struct mem_cgroup
*mem
,
3195 int node
, int zid
, enum lru_list lru
)
3198 struct mem_cgroup_per_zone
*mz
;
3199 struct page_cgroup
*pc
, *busy
;
3200 unsigned long flags
, loop
;
3201 struct list_head
*list
;
3204 zone
= &NODE_DATA(node
)->node_zones
[zid
];
3205 mz
= mem_cgroup_zoneinfo(mem
, node
, zid
);
3206 list
= &mz
->lists
[lru
];
3208 loop
= MEM_CGROUP_ZSTAT(mz
, lru
);
3209 /* give some margin against EBUSY etc...*/
3214 spin_lock_irqsave(&zone
->lru_lock
, flags
);
3215 if (list_empty(list
)) {
3216 spin_unlock_irqrestore(&zone
->lru_lock
, flags
);
3219 pc
= list_entry(list
->prev
, struct page_cgroup
, lru
);
3221 list_move(&pc
->lru
, list
);
3223 spin_unlock_irqrestore(&zone
->lru_lock
, flags
);
3226 spin_unlock_irqrestore(&zone
->lru_lock
, flags
);
3228 ret
= mem_cgroup_move_parent(pc
, mem
, GFP_KERNEL
);
3232 if (ret
== -EBUSY
|| ret
== -EINVAL
) {
3233 /* found lock contention or "pc" is obsolete. */
3240 if (!ret
&& !list_empty(list
))
3246 * make mem_cgroup's charge to be 0 if there is no task.
3247 * This enables deleting this mem_cgroup.
3249 static int mem_cgroup_force_empty(struct mem_cgroup
*mem
, bool free_all
)
3252 int node
, zid
, shrink
;
3253 int nr_retries
= MEM_CGROUP_RECLAIM_RETRIES
;
3254 struct cgroup
*cgrp
= mem
->css
.cgroup
;
3259 /* should free all ? */
3265 if (cgroup_task_count(cgrp
) || !list_empty(&cgrp
->children
))
3268 if (signal_pending(current
))
3270 /* This is for making all *used* pages to be on LRU. */
3271 lru_add_drain_all();
3272 drain_all_stock_sync();
3274 mem_cgroup_start_move(mem
);
3275 for_each_node_state(node
, N_HIGH_MEMORY
) {
3276 for (zid
= 0; !ret
&& zid
< MAX_NR_ZONES
; zid
++) {
3279 ret
= mem_cgroup_force_empty_list(mem
,
3288 mem_cgroup_end_move(mem
);
3289 memcg_oom_recover(mem
);
3290 /* it seems parent cgroup doesn't have enough mem */
3294 /* "ret" should also be checked to ensure all lists are empty. */
3295 } while (mem
->res
.usage
> 0 || ret
);
3301 /* returns EBUSY if there is a task or if we come here twice. */
3302 if (cgroup_task_count(cgrp
) || !list_empty(&cgrp
->children
) || shrink
) {
3306 /* we call try-to-free pages for make this cgroup empty */
3307 lru_add_drain_all();
3308 /* try to free all pages in this cgroup */
3310 while (nr_retries
&& mem
->res
.usage
> 0) {
3313 if (signal_pending(current
)) {
3317 progress
= try_to_free_mem_cgroup_pages(mem
, GFP_KERNEL
,
3318 false, get_swappiness(mem
));
3321 /* maybe some writeback is necessary */
3322 congestion_wait(BLK_RW_ASYNC
, HZ
/10);
3327 /* try move_account...there may be some *locked* pages. */
3331 int mem_cgroup_force_empty_write(struct cgroup
*cont
, unsigned int event
)
3333 return mem_cgroup_force_empty(mem_cgroup_from_cont(cont
), true);
3337 static u64
mem_cgroup_hierarchy_read(struct cgroup
*cont
, struct cftype
*cft
)
3339 return mem_cgroup_from_cont(cont
)->use_hierarchy
;
3342 static int mem_cgroup_hierarchy_write(struct cgroup
*cont
, struct cftype
*cft
,
3346 struct mem_cgroup
*mem
= mem_cgroup_from_cont(cont
);
3347 struct cgroup
*parent
= cont
->parent
;
3348 struct mem_cgroup
*parent_mem
= NULL
;
3351 parent_mem
= mem_cgroup_from_cont(parent
);
3355 * If parent's use_hierarchy is set, we can't make any modifications
3356 * in the child subtrees. If it is unset, then the change can
3357 * occur, provided the current cgroup has no children.
3359 * For the root cgroup, parent_mem is NULL, we allow value to be
3360 * set if there are no children.
3362 if ((!parent_mem
|| !parent_mem
->use_hierarchy
) &&
3363 (val
== 1 || val
== 0)) {
3364 if (list_empty(&cont
->children
))
3365 mem
->use_hierarchy
= val
;
3376 static u64
mem_cgroup_get_recursive_idx_stat(struct mem_cgroup
*mem
,
3377 enum mem_cgroup_stat_index idx
)
3379 struct mem_cgroup
*iter
;
3382 /* each per cpu's value can be minus.Then, use s64 */
3383 for_each_mem_cgroup_tree(iter
, mem
)
3384 val
+= mem_cgroup_read_stat(iter
, idx
);
3386 if (val
< 0) /* race ? */
3391 static inline u64
mem_cgroup_usage(struct mem_cgroup
*mem
, bool swap
)
3395 if (!mem_cgroup_is_root(mem
)) {
3397 return res_counter_read_u64(&mem
->res
, RES_USAGE
);
3399 return res_counter_read_u64(&mem
->memsw
, RES_USAGE
);
3402 val
= mem_cgroup_get_recursive_idx_stat(mem
, MEM_CGROUP_STAT_CACHE
);
3403 val
+= mem_cgroup_get_recursive_idx_stat(mem
, MEM_CGROUP_STAT_RSS
);
3406 val
+= mem_cgroup_get_recursive_idx_stat(mem
,
3407 MEM_CGROUP_STAT_SWAPOUT
);
3409 return val
<< PAGE_SHIFT
;
3412 static u64
mem_cgroup_read(struct cgroup
*cont
, struct cftype
*cft
)
3414 struct mem_cgroup
*mem
= mem_cgroup_from_cont(cont
);
3418 type
= MEMFILE_TYPE(cft
->private);
3419 name
= MEMFILE_ATTR(cft
->private);
3422 if (name
== RES_USAGE
)
3423 val
= mem_cgroup_usage(mem
, false);
3425 val
= res_counter_read_u64(&mem
->res
, name
);
3428 if (name
== RES_USAGE
)
3429 val
= mem_cgroup_usage(mem
, true);
3431 val
= res_counter_read_u64(&mem
->memsw
, name
);
3440 * The user of this function is...
3443 static int mem_cgroup_write(struct cgroup
*cont
, struct cftype
*cft
,
3446 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cont
);
3448 unsigned long long val
;
3451 type
= MEMFILE_TYPE(cft
->private);
3452 name
= MEMFILE_ATTR(cft
->private);
3455 if (mem_cgroup_is_root(memcg
)) { /* Can't set limit on root */
3459 /* This function does all necessary parse...reuse it */
3460 ret
= res_counter_memparse_write_strategy(buffer
, &val
);
3464 ret
= mem_cgroup_resize_limit(memcg
, val
);
3466 ret
= mem_cgroup_resize_memsw_limit(memcg
, val
);
3468 case RES_SOFT_LIMIT
:
3469 ret
= res_counter_memparse_write_strategy(buffer
, &val
);
3473 * For memsw, soft limits are hard to implement in terms
3474 * of semantics, for now, we support soft limits for
3475 * control without swap
3478 ret
= res_counter_set_soft_limit(&memcg
->res
, val
);
3483 ret
= -EINVAL
; /* should be BUG() ? */
3489 static void memcg_get_hierarchical_limit(struct mem_cgroup
*memcg
,
3490 unsigned long long *mem_limit
, unsigned long long *memsw_limit
)
3492 struct cgroup
*cgroup
;
3493 unsigned long long min_limit
, min_memsw_limit
, tmp
;
3495 min_limit
= res_counter_read_u64(&memcg
->res
, RES_LIMIT
);
3496 min_memsw_limit
= res_counter_read_u64(&memcg
->memsw
, RES_LIMIT
);
3497 cgroup
= memcg
->css
.cgroup
;
3498 if (!memcg
->use_hierarchy
)
3501 while (cgroup
->parent
) {
3502 cgroup
= cgroup
->parent
;
3503 memcg
= mem_cgroup_from_cont(cgroup
);
3504 if (!memcg
->use_hierarchy
)
3506 tmp
= res_counter_read_u64(&memcg
->res
, RES_LIMIT
);
3507 min_limit
= min(min_limit
, tmp
);
3508 tmp
= res_counter_read_u64(&memcg
->memsw
, RES_LIMIT
);
3509 min_memsw_limit
= min(min_memsw_limit
, tmp
);
3512 *mem_limit
= min_limit
;
3513 *memsw_limit
= min_memsw_limit
;
3517 static int mem_cgroup_reset(struct cgroup
*cont
, unsigned int event
)
3519 struct mem_cgroup
*mem
;
3522 mem
= mem_cgroup_from_cont(cont
);
3523 type
= MEMFILE_TYPE(event
);
3524 name
= MEMFILE_ATTR(event
);
3528 res_counter_reset_max(&mem
->res
);
3530 res_counter_reset_max(&mem
->memsw
);
3534 res_counter_reset_failcnt(&mem
->res
);
3536 res_counter_reset_failcnt(&mem
->memsw
);
3543 static u64
mem_cgroup_move_charge_read(struct cgroup
*cgrp
,
3546 return mem_cgroup_from_cont(cgrp
)->move_charge_at_immigrate
;
3550 static int mem_cgroup_move_charge_write(struct cgroup
*cgrp
,
3551 struct cftype
*cft
, u64 val
)
3553 struct mem_cgroup
*mem
= mem_cgroup_from_cont(cgrp
);
3555 if (val
>= (1 << NR_MOVE_TYPE
))
3558 * We check this value several times in both in can_attach() and
3559 * attach(), so we need cgroup lock to prevent this value from being
3563 mem
->move_charge_at_immigrate
= val
;
3569 static int mem_cgroup_move_charge_write(struct cgroup
*cgrp
,
3570 struct cftype
*cft
, u64 val
)
3577 /* For read statistics */
3593 struct mcs_total_stat
{
3594 s64 stat
[NR_MCS_STAT
];
3600 } memcg_stat_strings
[NR_MCS_STAT
] = {
3601 {"cache", "total_cache"},
3602 {"rss", "total_rss"},
3603 {"mapped_file", "total_mapped_file"},
3604 {"pgpgin", "total_pgpgin"},
3605 {"pgpgout", "total_pgpgout"},
3606 {"swap", "total_swap"},
3607 {"inactive_anon", "total_inactive_anon"},
3608 {"active_anon", "total_active_anon"},
3609 {"inactive_file", "total_inactive_file"},
3610 {"active_file", "total_active_file"},
3611 {"unevictable", "total_unevictable"}
3616 mem_cgroup_get_local_stat(struct mem_cgroup
*mem
, struct mcs_total_stat
*s
)
3621 val
= mem_cgroup_read_stat(mem
, MEM_CGROUP_STAT_CACHE
);
3622 s
->stat
[MCS_CACHE
] += val
* PAGE_SIZE
;
3623 val
= mem_cgroup_read_stat(mem
, MEM_CGROUP_STAT_RSS
);
3624 s
->stat
[MCS_RSS
] += val
* PAGE_SIZE
;
3625 val
= mem_cgroup_read_stat(mem
, MEM_CGROUP_STAT_FILE_MAPPED
);
3626 s
->stat
[MCS_FILE_MAPPED
] += val
* PAGE_SIZE
;
3627 val
= mem_cgroup_read_stat(mem
, MEM_CGROUP_STAT_PGPGIN_COUNT
);
3628 s
->stat
[MCS_PGPGIN
] += val
;
3629 val
= mem_cgroup_read_stat(mem
, MEM_CGROUP_STAT_PGPGOUT_COUNT
);
3630 s
->stat
[MCS_PGPGOUT
] += val
;
3631 if (do_swap_account
) {
3632 val
= mem_cgroup_read_stat(mem
, MEM_CGROUP_STAT_SWAPOUT
);
3633 s
->stat
[MCS_SWAP
] += val
* PAGE_SIZE
;
3637 val
= mem_cgroup_get_local_zonestat(mem
, LRU_INACTIVE_ANON
);
3638 s
->stat
[MCS_INACTIVE_ANON
] += val
* PAGE_SIZE
;
3639 val
= mem_cgroup_get_local_zonestat(mem
, LRU_ACTIVE_ANON
);
3640 s
->stat
[MCS_ACTIVE_ANON
] += val
* PAGE_SIZE
;
3641 val
= mem_cgroup_get_local_zonestat(mem
, LRU_INACTIVE_FILE
);
3642 s
->stat
[MCS_INACTIVE_FILE
] += val
* PAGE_SIZE
;
3643 val
= mem_cgroup_get_local_zonestat(mem
, LRU_ACTIVE_FILE
);
3644 s
->stat
[MCS_ACTIVE_FILE
] += val
* PAGE_SIZE
;
3645 val
= mem_cgroup_get_local_zonestat(mem
, LRU_UNEVICTABLE
);
3646 s
->stat
[MCS_UNEVICTABLE
] += val
* PAGE_SIZE
;
3650 mem_cgroup_get_total_stat(struct mem_cgroup
*mem
, struct mcs_total_stat
*s
)
3652 struct mem_cgroup
*iter
;
3654 for_each_mem_cgroup_tree(iter
, mem
)
3655 mem_cgroup_get_local_stat(iter
, s
);
3658 static int mem_control_stat_show(struct cgroup
*cont
, struct cftype
*cft
,
3659 struct cgroup_map_cb
*cb
)
3661 struct mem_cgroup
*mem_cont
= mem_cgroup_from_cont(cont
);
3662 struct mcs_total_stat mystat
;
3665 memset(&mystat
, 0, sizeof(mystat
));
3666 mem_cgroup_get_local_stat(mem_cont
, &mystat
);
3668 for (i
= 0; i
< NR_MCS_STAT
; i
++) {
3669 if (i
== MCS_SWAP
&& !do_swap_account
)
3671 cb
->fill(cb
, memcg_stat_strings
[i
].local_name
, mystat
.stat
[i
]);
3674 /* Hierarchical information */
3676 unsigned long long limit
, memsw_limit
;
3677 memcg_get_hierarchical_limit(mem_cont
, &limit
, &memsw_limit
);
3678 cb
->fill(cb
, "hierarchical_memory_limit", limit
);
3679 if (do_swap_account
)
3680 cb
->fill(cb
, "hierarchical_memsw_limit", memsw_limit
);
3683 memset(&mystat
, 0, sizeof(mystat
));
3684 mem_cgroup_get_total_stat(mem_cont
, &mystat
);
3685 for (i
= 0; i
< NR_MCS_STAT
; i
++) {
3686 if (i
== MCS_SWAP
&& !do_swap_account
)
3688 cb
->fill(cb
, memcg_stat_strings
[i
].total_name
, mystat
.stat
[i
]);
3691 #ifdef CONFIG_DEBUG_VM
3692 cb
->fill(cb
, "inactive_ratio", calc_inactive_ratio(mem_cont
, NULL
));
3696 struct mem_cgroup_per_zone
*mz
;
3697 unsigned long recent_rotated
[2] = {0, 0};
3698 unsigned long recent_scanned
[2] = {0, 0};
3700 for_each_online_node(nid
)
3701 for (zid
= 0; zid
< MAX_NR_ZONES
; zid
++) {
3702 mz
= mem_cgroup_zoneinfo(mem_cont
, nid
, zid
);
3704 recent_rotated
[0] +=
3705 mz
->reclaim_stat
.recent_rotated
[0];
3706 recent_rotated
[1] +=
3707 mz
->reclaim_stat
.recent_rotated
[1];
3708 recent_scanned
[0] +=
3709 mz
->reclaim_stat
.recent_scanned
[0];
3710 recent_scanned
[1] +=
3711 mz
->reclaim_stat
.recent_scanned
[1];
3713 cb
->fill(cb
, "recent_rotated_anon", recent_rotated
[0]);
3714 cb
->fill(cb
, "recent_rotated_file", recent_rotated
[1]);
3715 cb
->fill(cb
, "recent_scanned_anon", recent_scanned
[0]);
3716 cb
->fill(cb
, "recent_scanned_file", recent_scanned
[1]);
3723 static u64
mem_cgroup_swappiness_read(struct cgroup
*cgrp
, struct cftype
*cft
)
3725 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cgrp
);
3727 return get_swappiness(memcg
);
3730 static int mem_cgroup_swappiness_write(struct cgroup
*cgrp
, struct cftype
*cft
,
3733 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cgrp
);
3734 struct mem_cgroup
*parent
;
3739 if (cgrp
->parent
== NULL
)
3742 parent
= mem_cgroup_from_cont(cgrp
->parent
);
3746 /* If under hierarchy, only empty-root can set this value */
3747 if ((parent
->use_hierarchy
) ||
3748 (memcg
->use_hierarchy
&& !list_empty(&cgrp
->children
))) {
3753 spin_lock(&memcg
->reclaim_param_lock
);
3754 memcg
->swappiness
= val
;
3755 spin_unlock(&memcg
->reclaim_param_lock
);
3762 static void __mem_cgroup_threshold(struct mem_cgroup
*memcg
, bool swap
)
3764 struct mem_cgroup_threshold_ary
*t
;
3770 t
= rcu_dereference(memcg
->thresholds
.primary
);
3772 t
= rcu_dereference(memcg
->memsw_thresholds
.primary
);
3777 usage
= mem_cgroup_usage(memcg
, swap
);
3780 * current_threshold points to threshold just below usage.
3781 * If it's not true, a threshold was crossed after last
3782 * call of __mem_cgroup_threshold().
3784 i
= t
->current_threshold
;
3787 * Iterate backward over array of thresholds starting from
3788 * current_threshold and check if a threshold is crossed.
3789 * If none of thresholds below usage is crossed, we read
3790 * only one element of the array here.
3792 for (; i
>= 0 && unlikely(t
->entries
[i
].threshold
> usage
); i
--)
3793 eventfd_signal(t
->entries
[i
].eventfd
, 1);
3795 /* i = current_threshold + 1 */
3799 * Iterate forward over array of thresholds starting from
3800 * current_threshold+1 and check if a threshold is crossed.
3801 * If none of thresholds above usage is crossed, we read
3802 * only one element of the array here.
3804 for (; i
< t
->size
&& unlikely(t
->entries
[i
].threshold
<= usage
); i
++)
3805 eventfd_signal(t
->entries
[i
].eventfd
, 1);
3807 /* Update current_threshold */
3808 t
->current_threshold
= i
- 1;
3813 static void mem_cgroup_threshold(struct mem_cgroup
*memcg
)
3816 __mem_cgroup_threshold(memcg
, false);
3817 if (do_swap_account
)
3818 __mem_cgroup_threshold(memcg
, true);
3820 memcg
= parent_mem_cgroup(memcg
);
3824 static int compare_thresholds(const void *a
, const void *b
)
3826 const struct mem_cgroup_threshold
*_a
= a
;
3827 const struct mem_cgroup_threshold
*_b
= b
;
3829 return _a
->threshold
- _b
->threshold
;
3832 static int mem_cgroup_oom_notify_cb(struct mem_cgroup
*mem
)
3834 struct mem_cgroup_eventfd_list
*ev
;
3836 list_for_each_entry(ev
, &mem
->oom_notify
, list
)
3837 eventfd_signal(ev
->eventfd
, 1);
3841 static void mem_cgroup_oom_notify(struct mem_cgroup
*mem
)
3843 struct mem_cgroup
*iter
;
3845 for_each_mem_cgroup_tree(iter
, mem
)
3846 mem_cgroup_oom_notify_cb(iter
);
3849 static int mem_cgroup_usage_register_event(struct cgroup
*cgrp
,
3850 struct cftype
*cft
, struct eventfd_ctx
*eventfd
, const char *args
)
3852 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cgrp
);
3853 struct mem_cgroup_thresholds
*thresholds
;
3854 struct mem_cgroup_threshold_ary
*new;
3855 int type
= MEMFILE_TYPE(cft
->private);
3856 u64 threshold
, usage
;
3859 ret
= res_counter_memparse_write_strategy(args
, &threshold
);
3863 mutex_lock(&memcg
->thresholds_lock
);
3866 thresholds
= &memcg
->thresholds
;
3867 else if (type
== _MEMSWAP
)
3868 thresholds
= &memcg
->memsw_thresholds
;
3872 usage
= mem_cgroup_usage(memcg
, type
== _MEMSWAP
);
3874 /* Check if a threshold crossed before adding a new one */
3875 if (thresholds
->primary
)
3876 __mem_cgroup_threshold(memcg
, type
== _MEMSWAP
);
3878 size
= thresholds
->primary
? thresholds
->primary
->size
+ 1 : 1;
3880 /* Allocate memory for new array of thresholds */
3881 new = kmalloc(sizeof(*new) + size
* sizeof(struct mem_cgroup_threshold
),
3889 /* Copy thresholds (if any) to new array */
3890 if (thresholds
->primary
) {
3891 memcpy(new->entries
, thresholds
->primary
->entries
, (size
- 1) *
3892 sizeof(struct mem_cgroup_threshold
));
3895 /* Add new threshold */
3896 new->entries
[size
- 1].eventfd
= eventfd
;
3897 new->entries
[size
- 1].threshold
= threshold
;
3899 /* Sort thresholds. Registering of new threshold isn't time-critical */
3900 sort(new->entries
, size
, sizeof(struct mem_cgroup_threshold
),
3901 compare_thresholds
, NULL
);
3903 /* Find current threshold */
3904 new->current_threshold
= -1;
3905 for (i
= 0; i
< size
; i
++) {
3906 if (new->entries
[i
].threshold
< usage
) {
3908 * new->current_threshold will not be used until
3909 * rcu_assign_pointer(), so it's safe to increment
3912 ++new->current_threshold
;
3916 /* Free old spare buffer and save old primary buffer as spare */
3917 kfree(thresholds
->spare
);
3918 thresholds
->spare
= thresholds
->primary
;
3920 rcu_assign_pointer(thresholds
->primary
, new);
3922 /* To be sure that nobody uses thresholds */
3926 mutex_unlock(&memcg
->thresholds_lock
);
3931 static void mem_cgroup_usage_unregister_event(struct cgroup
*cgrp
,
3932 struct cftype
*cft
, struct eventfd_ctx
*eventfd
)
3934 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cgrp
);
3935 struct mem_cgroup_thresholds
*thresholds
;
3936 struct mem_cgroup_threshold_ary
*new;
3937 int type
= MEMFILE_TYPE(cft
->private);
3941 mutex_lock(&memcg
->thresholds_lock
);
3943 thresholds
= &memcg
->thresholds
;
3944 else if (type
== _MEMSWAP
)
3945 thresholds
= &memcg
->memsw_thresholds
;
3950 * Something went wrong if we trying to unregister a threshold
3951 * if we don't have thresholds
3953 BUG_ON(!thresholds
);
3955 usage
= mem_cgroup_usage(memcg
, type
== _MEMSWAP
);
3957 /* Check if a threshold crossed before removing */
3958 __mem_cgroup_threshold(memcg
, type
== _MEMSWAP
);
3960 /* Calculate new number of threshold */
3962 for (i
= 0; i
< thresholds
->primary
->size
; i
++) {
3963 if (thresholds
->primary
->entries
[i
].eventfd
!= eventfd
)
3967 new = thresholds
->spare
;
3969 /* Set thresholds array to NULL if we don't have thresholds */
3978 /* Copy thresholds and find current threshold */
3979 new->current_threshold
= -1;
3980 for (i
= 0, j
= 0; i
< thresholds
->primary
->size
; i
++) {
3981 if (thresholds
->primary
->entries
[i
].eventfd
== eventfd
)
3984 new->entries
[j
] = thresholds
->primary
->entries
[i
];
3985 if (new->entries
[j
].threshold
< usage
) {
3987 * new->current_threshold will not be used
3988 * until rcu_assign_pointer(), so it's safe to increment
3991 ++new->current_threshold
;
3997 /* Swap primary and spare array */
3998 thresholds
->spare
= thresholds
->primary
;
3999 rcu_assign_pointer(thresholds
->primary
, new);
4001 /* To be sure that nobody uses thresholds */
4004 mutex_unlock(&memcg
->thresholds_lock
);
4007 static int mem_cgroup_oom_register_event(struct cgroup
*cgrp
,
4008 struct cftype
*cft
, struct eventfd_ctx
*eventfd
, const char *args
)
4010 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cgrp
);
4011 struct mem_cgroup_eventfd_list
*event
;
4012 int type
= MEMFILE_TYPE(cft
->private);
4014 BUG_ON(type
!= _OOM_TYPE
);
4015 event
= kmalloc(sizeof(*event
), GFP_KERNEL
);
4019 mutex_lock(&memcg_oom_mutex
);
4021 event
->eventfd
= eventfd
;
4022 list_add(&event
->list
, &memcg
->oom_notify
);
4024 /* already in OOM ? */
4025 if (atomic_read(&memcg
->oom_lock
))
4026 eventfd_signal(eventfd
, 1);
4027 mutex_unlock(&memcg_oom_mutex
);
4032 static void mem_cgroup_oom_unregister_event(struct cgroup
*cgrp
,
4033 struct cftype
*cft
, struct eventfd_ctx
*eventfd
)
4035 struct mem_cgroup
*mem
= mem_cgroup_from_cont(cgrp
);
4036 struct mem_cgroup_eventfd_list
*ev
, *tmp
;
4037 int type
= MEMFILE_TYPE(cft
->private);
4039 BUG_ON(type
!= _OOM_TYPE
);
4041 mutex_lock(&memcg_oom_mutex
);
4043 list_for_each_entry_safe(ev
, tmp
, &mem
->oom_notify
, list
) {
4044 if (ev
->eventfd
== eventfd
) {
4045 list_del(&ev
->list
);
4050 mutex_unlock(&memcg_oom_mutex
);
4053 static int mem_cgroup_oom_control_read(struct cgroup
*cgrp
,
4054 struct cftype
*cft
, struct cgroup_map_cb
*cb
)
4056 struct mem_cgroup
*mem
= mem_cgroup_from_cont(cgrp
);
4058 cb
->fill(cb
, "oom_kill_disable", mem
->oom_kill_disable
);
4060 if (atomic_read(&mem
->oom_lock
))
4061 cb
->fill(cb
, "under_oom", 1);
4063 cb
->fill(cb
, "under_oom", 0);
4067 static int mem_cgroup_oom_control_write(struct cgroup
*cgrp
,
4068 struct cftype
*cft
, u64 val
)
4070 struct mem_cgroup
*mem
= mem_cgroup_from_cont(cgrp
);
4071 struct mem_cgroup
*parent
;
4073 /* cannot set to root cgroup and only 0 and 1 are allowed */
4074 if (!cgrp
->parent
|| !((val
== 0) || (val
== 1)))
4077 parent
= mem_cgroup_from_cont(cgrp
->parent
);
4080 /* oom-kill-disable is a flag for subhierarchy. */
4081 if ((parent
->use_hierarchy
) ||
4082 (mem
->use_hierarchy
&& !list_empty(&cgrp
->children
))) {
4086 mem
->oom_kill_disable
= val
;
4088 memcg_oom_recover(mem
);
4093 static struct cftype mem_cgroup_files
[] = {
4095 .name
= "usage_in_bytes",
4096 .private = MEMFILE_PRIVATE(_MEM
, RES_USAGE
),
4097 .read_u64
= mem_cgroup_read
,
4098 .register_event
= mem_cgroup_usage_register_event
,
4099 .unregister_event
= mem_cgroup_usage_unregister_event
,
4102 .name
= "max_usage_in_bytes",
4103 .private = MEMFILE_PRIVATE(_MEM
, RES_MAX_USAGE
),
4104 .trigger
= mem_cgroup_reset
,
4105 .read_u64
= mem_cgroup_read
,
4108 .name
= "limit_in_bytes",
4109 .private = MEMFILE_PRIVATE(_MEM
, RES_LIMIT
),
4110 .write_string
= mem_cgroup_write
,
4111 .read_u64
= mem_cgroup_read
,
4114 .name
= "soft_limit_in_bytes",
4115 .private = MEMFILE_PRIVATE(_MEM
, RES_SOFT_LIMIT
),
4116 .write_string
= mem_cgroup_write
,
4117 .read_u64
= mem_cgroup_read
,
4121 .private = MEMFILE_PRIVATE(_MEM
, RES_FAILCNT
),
4122 .trigger
= mem_cgroup_reset
,
4123 .read_u64
= mem_cgroup_read
,
4127 .read_map
= mem_control_stat_show
,
4130 .name
= "force_empty",
4131 .trigger
= mem_cgroup_force_empty_write
,
4134 .name
= "use_hierarchy",
4135 .write_u64
= mem_cgroup_hierarchy_write
,
4136 .read_u64
= mem_cgroup_hierarchy_read
,
4139 .name
= "swappiness",
4140 .read_u64
= mem_cgroup_swappiness_read
,
4141 .write_u64
= mem_cgroup_swappiness_write
,
4144 .name
= "move_charge_at_immigrate",
4145 .read_u64
= mem_cgroup_move_charge_read
,
4146 .write_u64
= mem_cgroup_move_charge_write
,
4149 .name
= "oom_control",
4150 .read_map
= mem_cgroup_oom_control_read
,
4151 .write_u64
= mem_cgroup_oom_control_write
,
4152 .register_event
= mem_cgroup_oom_register_event
,
4153 .unregister_event
= mem_cgroup_oom_unregister_event
,
4154 .private = MEMFILE_PRIVATE(_OOM_TYPE
, OOM_CONTROL
),
4158 #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP
4159 static struct cftype memsw_cgroup_files
[] = {
4161 .name
= "memsw.usage_in_bytes",
4162 .private = MEMFILE_PRIVATE(_MEMSWAP
, RES_USAGE
),
4163 .read_u64
= mem_cgroup_read
,
4164 .register_event
= mem_cgroup_usage_register_event
,
4165 .unregister_event
= mem_cgroup_usage_unregister_event
,
4168 .name
= "memsw.max_usage_in_bytes",
4169 .private = MEMFILE_PRIVATE(_MEMSWAP
, RES_MAX_USAGE
),
4170 .trigger
= mem_cgroup_reset
,
4171 .read_u64
= mem_cgroup_read
,
4174 .name
= "memsw.limit_in_bytes",
4175 .private = MEMFILE_PRIVATE(_MEMSWAP
, RES_LIMIT
),
4176 .write_string
= mem_cgroup_write
,
4177 .read_u64
= mem_cgroup_read
,
4180 .name
= "memsw.failcnt",
4181 .private = MEMFILE_PRIVATE(_MEMSWAP
, RES_FAILCNT
),
4182 .trigger
= mem_cgroup_reset
,
4183 .read_u64
= mem_cgroup_read
,
4187 static int register_memsw_files(struct cgroup
*cont
, struct cgroup_subsys
*ss
)
4189 if (!do_swap_account
)
4191 return cgroup_add_files(cont
, ss
, memsw_cgroup_files
,
4192 ARRAY_SIZE(memsw_cgroup_files
));
4195 static int register_memsw_files(struct cgroup
*cont
, struct cgroup_subsys
*ss
)
4201 static int alloc_mem_cgroup_per_zone_info(struct mem_cgroup
*mem
, int node
)
4203 struct mem_cgroup_per_node
*pn
;
4204 struct mem_cgroup_per_zone
*mz
;
4206 int zone
, tmp
= node
;
4208 * This routine is called against possible nodes.
4209 * But it's BUG to call kmalloc() against offline node.
4211 * TODO: this routine can waste much memory for nodes which will
4212 * never be onlined. It's better to use memory hotplug callback
4215 if (!node_state(node
, N_NORMAL_MEMORY
))
4217 pn
= kmalloc_node(sizeof(*pn
), GFP_KERNEL
, tmp
);
4221 mem
->info
.nodeinfo
[node
] = pn
;
4222 memset(pn
, 0, sizeof(*pn
));
4224 for (zone
= 0; zone
< MAX_NR_ZONES
; zone
++) {
4225 mz
= &pn
->zoneinfo
[zone
];
4227 INIT_LIST_HEAD(&mz
->lists
[l
]);
4228 mz
->usage_in_excess
= 0;
4229 mz
->on_tree
= false;
4235 static void free_mem_cgroup_per_zone_info(struct mem_cgroup
*mem
, int node
)
4237 kfree(mem
->info
.nodeinfo
[node
]);
4240 static struct mem_cgroup
*mem_cgroup_alloc(void)
4242 struct mem_cgroup
*mem
;
4243 int size
= sizeof(struct mem_cgroup
);
4245 /* Can be very big if MAX_NUMNODES is very big */
4246 if (size
< PAGE_SIZE
)
4247 mem
= kmalloc(size
, GFP_KERNEL
);
4249 mem
= vmalloc(size
);
4254 memset(mem
, 0, size
);
4255 mem
->stat
= alloc_percpu(struct mem_cgroup_stat_cpu
);
4258 spin_lock_init(&mem
->pcp_counter_lock
);
4262 if (size
< PAGE_SIZE
)
4270 * At destroying mem_cgroup, references from swap_cgroup can remain.
4271 * (scanning all at force_empty is too costly...)
4273 * Instead of clearing all references at force_empty, we remember
4274 * the number of reference from swap_cgroup and free mem_cgroup when
4275 * it goes down to 0.
4277 * Removal of cgroup itself succeeds regardless of refs from swap.
4280 static void __mem_cgroup_free(struct mem_cgroup
*mem
)
4284 mem_cgroup_remove_from_trees(mem
);
4285 free_css_id(&mem_cgroup_subsys
, &mem
->css
);
4287 for_each_node_state(node
, N_POSSIBLE
)
4288 free_mem_cgroup_per_zone_info(mem
, node
);
4290 free_percpu(mem
->stat
);
4291 if (sizeof(struct mem_cgroup
) < PAGE_SIZE
)
4297 static void mem_cgroup_get(struct mem_cgroup
*mem
)
4299 atomic_inc(&mem
->refcnt
);
4302 static void __mem_cgroup_put(struct mem_cgroup
*mem
, int count
)
4304 if (atomic_sub_and_test(count
, &mem
->refcnt
)) {
4305 struct mem_cgroup
*parent
= parent_mem_cgroup(mem
);
4306 __mem_cgroup_free(mem
);
4308 mem_cgroup_put(parent
);
4312 static void mem_cgroup_put(struct mem_cgroup
*mem
)
4314 __mem_cgroup_put(mem
, 1);
4318 * Returns the parent mem_cgroup in memcgroup hierarchy with hierarchy enabled.
4320 static struct mem_cgroup
*parent_mem_cgroup(struct mem_cgroup
*mem
)
4322 if (!mem
->res
.parent
)
4324 return mem_cgroup_from_res_counter(mem
->res
.parent
, res
);
4327 #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP
4328 static void __init
enable_swap_cgroup(void)
4330 if (!mem_cgroup_disabled() && really_do_swap_account
)
4331 do_swap_account
= 1;
4334 static void __init
enable_swap_cgroup(void)
4339 static int mem_cgroup_soft_limit_tree_init(void)
4341 struct mem_cgroup_tree_per_node
*rtpn
;
4342 struct mem_cgroup_tree_per_zone
*rtpz
;
4343 int tmp
, node
, zone
;
4345 for_each_node_state(node
, N_POSSIBLE
) {
4347 if (!node_state(node
, N_NORMAL_MEMORY
))
4349 rtpn
= kzalloc_node(sizeof(*rtpn
), GFP_KERNEL
, tmp
);
4353 soft_limit_tree
.rb_tree_per_node
[node
] = rtpn
;
4355 for (zone
= 0; zone
< MAX_NR_ZONES
; zone
++) {
4356 rtpz
= &rtpn
->rb_tree_per_zone
[zone
];
4357 rtpz
->rb_root
= RB_ROOT
;
4358 spin_lock_init(&rtpz
->lock
);
4364 static struct cgroup_subsys_state
* __ref
4365 mem_cgroup_create(struct cgroup_subsys
*ss
, struct cgroup
*cont
)
4367 struct mem_cgroup
*mem
, *parent
;
4368 long error
= -ENOMEM
;
4371 mem
= mem_cgroup_alloc();
4373 return ERR_PTR(error
);
4375 for_each_node_state(node
, N_POSSIBLE
)
4376 if (alloc_mem_cgroup_per_zone_info(mem
, node
))
4380 if (cont
->parent
== NULL
) {
4382 enable_swap_cgroup();
4384 root_mem_cgroup
= mem
;
4385 if (mem_cgroup_soft_limit_tree_init())
4387 for_each_possible_cpu(cpu
) {
4388 struct memcg_stock_pcp
*stock
=
4389 &per_cpu(memcg_stock
, cpu
);
4390 INIT_WORK(&stock
->work
, drain_local_stock
);
4392 hotcpu_notifier(memcg_cpu_hotplug_callback
, 0);
4394 parent
= mem_cgroup_from_cont(cont
->parent
);
4395 mem
->use_hierarchy
= parent
->use_hierarchy
;
4396 mem
->oom_kill_disable
= parent
->oom_kill_disable
;
4399 if (parent
&& parent
->use_hierarchy
) {
4400 res_counter_init(&mem
->res
, &parent
->res
);
4401 res_counter_init(&mem
->memsw
, &parent
->memsw
);
4403 * We increment refcnt of the parent to ensure that we can
4404 * safely access it on res_counter_charge/uncharge.
4405 * This refcnt will be decremented when freeing this
4406 * mem_cgroup(see mem_cgroup_put).
4408 mem_cgroup_get(parent
);
4410 res_counter_init(&mem
->res
, NULL
);
4411 res_counter_init(&mem
->memsw
, NULL
);
4413 mem
->last_scanned_child
= 0;
4414 spin_lock_init(&mem
->reclaim_param_lock
);
4415 INIT_LIST_HEAD(&mem
->oom_notify
);
4418 mem
->swappiness
= get_swappiness(parent
);
4419 atomic_set(&mem
->refcnt
, 1);
4420 mem
->move_charge_at_immigrate
= 0;
4421 mutex_init(&mem
->thresholds_lock
);
4424 __mem_cgroup_free(mem
);
4425 root_mem_cgroup
= NULL
;
4426 return ERR_PTR(error
);
4429 static int mem_cgroup_pre_destroy(struct cgroup_subsys
*ss
,
4430 struct cgroup
*cont
)
4432 struct mem_cgroup
*mem
= mem_cgroup_from_cont(cont
);
4434 return mem_cgroup_force_empty(mem
, false);
4437 static void mem_cgroup_destroy(struct cgroup_subsys
*ss
,
4438 struct cgroup
*cont
)
4440 struct mem_cgroup
*mem
= mem_cgroup_from_cont(cont
);
4442 mem_cgroup_put(mem
);
4445 static int mem_cgroup_populate(struct cgroup_subsys
*ss
,
4446 struct cgroup
*cont
)
4450 ret
= cgroup_add_files(cont
, ss
, mem_cgroup_files
,
4451 ARRAY_SIZE(mem_cgroup_files
));
4454 ret
= register_memsw_files(cont
, ss
);
4459 /* Handlers for move charge at task migration. */
4460 #define PRECHARGE_COUNT_AT_ONCE 256
4461 static int mem_cgroup_do_precharge(unsigned long count
)
4464 int batch_count
= PRECHARGE_COUNT_AT_ONCE
;
4465 struct mem_cgroup
*mem
= mc
.to
;
4467 if (mem_cgroup_is_root(mem
)) {
4468 mc
.precharge
+= count
;
4469 /* we don't need css_get for root */
4472 /* try to charge at once */
4474 struct res_counter
*dummy
;
4476 * "mem" cannot be under rmdir() because we've already checked
4477 * by cgroup_lock_live_cgroup() that it is not removed and we
4478 * are still under the same cgroup_mutex. So we can postpone
4481 if (res_counter_charge(&mem
->res
, PAGE_SIZE
* count
, &dummy
))
4483 if (do_swap_account
&& res_counter_charge(&mem
->memsw
,
4484 PAGE_SIZE
* count
, &dummy
)) {
4485 res_counter_uncharge(&mem
->res
, PAGE_SIZE
* count
);
4488 mc
.precharge
+= count
;
4492 /* fall back to one by one charge */
4494 if (signal_pending(current
)) {
4498 if (!batch_count
--) {
4499 batch_count
= PRECHARGE_COUNT_AT_ONCE
;
4502 ret
= __mem_cgroup_try_charge(NULL
, GFP_KERNEL
, &mem
, false,
4505 /* mem_cgroup_clear_mc() will do uncharge later */
4513 * is_target_pte_for_mc - check a pte whether it is valid for move charge
4514 * @vma: the vma the pte to be checked belongs
4515 * @addr: the address corresponding to the pte to be checked
4516 * @ptent: the pte to be checked
4517 * @target: the pointer the target page or swap ent will be stored(can be NULL)
4520 * 0(MC_TARGET_NONE): if the pte is not a target for move charge.
4521 * 1(MC_TARGET_PAGE): if the page corresponding to this pte is a target for
4522 * move charge. if @target is not NULL, the page is stored in target->page
4523 * with extra refcnt got(Callers should handle it).
4524 * 2(MC_TARGET_SWAP): if the swap entry corresponding to this pte is a
4525 * target for charge migration. if @target is not NULL, the entry is stored
4528 * Called with pte lock held.
4535 enum mc_target_type
{
4536 MC_TARGET_NONE
, /* not used */
4541 static struct page
*mc_handle_present_pte(struct vm_area_struct
*vma
,
4542 unsigned long addr
, pte_t ptent
)
4544 struct page
*page
= vm_normal_page(vma
, addr
, ptent
);
4546 if (!page
|| !page_mapped(page
))
4548 if (PageAnon(page
)) {
4549 /* we don't move shared anon */
4550 if (!move_anon() || page_mapcount(page
) > 2)
4552 } else if (!move_file())
4553 /* we ignore mapcount for file pages */
4555 if (!get_page_unless_zero(page
))
4561 static struct page
*mc_handle_swap_pte(struct vm_area_struct
*vma
,
4562 unsigned long addr
, pte_t ptent
, swp_entry_t
*entry
)
4565 struct page
*page
= NULL
;
4566 swp_entry_t ent
= pte_to_swp_entry(ptent
);
4568 if (!move_anon() || non_swap_entry(ent
))
4570 usage_count
= mem_cgroup_count_swap_user(ent
, &page
);
4571 if (usage_count
> 1) { /* we don't move shared anon */
4576 if (do_swap_account
)
4577 entry
->val
= ent
.val
;
4582 static struct page
*mc_handle_file_pte(struct vm_area_struct
*vma
,
4583 unsigned long addr
, pte_t ptent
, swp_entry_t
*entry
)
4585 struct page
*page
= NULL
;
4586 struct inode
*inode
;
4587 struct address_space
*mapping
;
4590 if (!vma
->vm_file
) /* anonymous vma */
4595 inode
= vma
->vm_file
->f_path
.dentry
->d_inode
;
4596 mapping
= vma
->vm_file
->f_mapping
;
4597 if (pte_none(ptent
))
4598 pgoff
= linear_page_index(vma
, addr
);
4599 else /* pte_file(ptent) is true */
4600 pgoff
= pte_to_pgoff(ptent
);
4602 /* page is moved even if it's not RSS of this task(page-faulted). */
4603 if (!mapping_cap_swap_backed(mapping
)) { /* normal file */
4604 page
= find_get_page(mapping
, pgoff
);
4605 } else { /* shmem/tmpfs file. we should take account of swap too. */
4607 mem_cgroup_get_shmem_target(inode
, pgoff
, &page
, &ent
);
4608 if (do_swap_account
)
4609 entry
->val
= ent
.val
;
4615 static int is_target_pte_for_mc(struct vm_area_struct
*vma
,
4616 unsigned long addr
, pte_t ptent
, union mc_target
*target
)
4618 struct page
*page
= NULL
;
4619 struct page_cgroup
*pc
;
4621 swp_entry_t ent
= { .val
= 0 };
4623 if (pte_present(ptent
))
4624 page
= mc_handle_present_pte(vma
, addr
, ptent
);
4625 else if (is_swap_pte(ptent
))
4626 page
= mc_handle_swap_pte(vma
, addr
, ptent
, &ent
);
4627 else if (pte_none(ptent
) || pte_file(ptent
))
4628 page
= mc_handle_file_pte(vma
, addr
, ptent
, &ent
);
4630 if (!page
&& !ent
.val
)
4633 pc
= lookup_page_cgroup(page
);
4635 * Do only loose check w/o page_cgroup lock.
4636 * mem_cgroup_move_account() checks the pc is valid or not under
4639 if (PageCgroupUsed(pc
) && pc
->mem_cgroup
== mc
.from
) {
4640 ret
= MC_TARGET_PAGE
;
4642 target
->page
= page
;
4644 if (!ret
|| !target
)
4647 /* There is a swap entry and a page doesn't exist or isn't charged */
4648 if (ent
.val
&& !ret
&&
4649 css_id(&mc
.from
->css
) == lookup_swap_cgroup(ent
)) {
4650 ret
= MC_TARGET_SWAP
;
4657 static int mem_cgroup_count_precharge_pte_range(pmd_t
*pmd
,
4658 unsigned long addr
, unsigned long end
,
4659 struct mm_walk
*walk
)
4661 struct vm_area_struct
*vma
= walk
->private;
4665 VM_BUG_ON(pmd_trans_huge(*pmd
));
4666 pte
= pte_offset_map_lock(vma
->vm_mm
, pmd
, addr
, &ptl
);
4667 for (; addr
!= end
; pte
++, addr
+= PAGE_SIZE
)
4668 if (is_target_pte_for_mc(vma
, addr
, *pte
, NULL
))
4669 mc
.precharge
++; /* increment precharge temporarily */
4670 pte_unmap_unlock(pte
- 1, ptl
);
4676 static unsigned long mem_cgroup_count_precharge(struct mm_struct
*mm
)
4678 unsigned long precharge
;
4679 struct vm_area_struct
*vma
;
4681 /* We've already held the mmap_sem */
4682 for (vma
= mm
->mmap
; vma
; vma
= vma
->vm_next
) {
4683 struct mm_walk mem_cgroup_count_precharge_walk
= {
4684 .pmd_entry
= mem_cgroup_count_precharge_pte_range
,
4688 if (is_vm_hugetlb_page(vma
))
4690 walk_page_range(vma
->vm_start
, vma
->vm_end
,
4691 &mem_cgroup_count_precharge_walk
);
4694 precharge
= mc
.precharge
;
4700 static int mem_cgroup_precharge_mc(struct mm_struct
*mm
)
4702 return mem_cgroup_do_precharge(mem_cgroup_count_precharge(mm
));
4705 static void mem_cgroup_clear_mc(void)
4707 struct mem_cgroup
*from
= mc
.from
;
4708 struct mem_cgroup
*to
= mc
.to
;
4710 /* we must uncharge all the leftover precharges from mc.to */
4712 __mem_cgroup_cancel_charge(mc
.to
, mc
.precharge
);
4716 * we didn't uncharge from mc.from at mem_cgroup_move_account(), so
4717 * we must uncharge here.
4719 if (mc
.moved_charge
) {
4720 __mem_cgroup_cancel_charge(mc
.from
, mc
.moved_charge
);
4721 mc
.moved_charge
= 0;
4723 /* we must fixup refcnts and charges */
4724 if (mc
.moved_swap
) {
4725 /* uncharge swap account from the old cgroup */
4726 if (!mem_cgroup_is_root(mc
.from
))
4727 res_counter_uncharge(&mc
.from
->memsw
,
4728 PAGE_SIZE
* mc
.moved_swap
);
4729 __mem_cgroup_put(mc
.from
, mc
.moved_swap
);
4731 if (!mem_cgroup_is_root(mc
.to
)) {
4733 * we charged both to->res and to->memsw, so we should
4736 res_counter_uncharge(&mc
.to
->res
,
4737 PAGE_SIZE
* mc
.moved_swap
);
4739 /* we've already done mem_cgroup_get(mc.to) */
4744 up_read(&mc
.mm
->mmap_sem
);
4747 spin_lock(&mc
.lock
);
4750 spin_unlock(&mc
.lock
);
4751 mc
.moving_task
= NULL
;
4753 mem_cgroup_end_move(from
);
4754 memcg_oom_recover(from
);
4755 memcg_oom_recover(to
);
4756 wake_up_all(&mc
.waitq
);
4759 static int mem_cgroup_can_attach(struct cgroup_subsys
*ss
,
4760 struct cgroup
*cgroup
,
4761 struct task_struct
*p
,
4765 struct mem_cgroup
*mem
= mem_cgroup_from_cont(cgroup
);
4767 if (mem
->move_charge_at_immigrate
) {
4768 struct mm_struct
*mm
;
4769 struct mem_cgroup
*from
= mem_cgroup_from_task(p
);
4771 VM_BUG_ON(from
== mem
);
4773 mm
= get_task_mm(p
);
4776 /* We move charges only when we move a owner of the mm */
4777 if (mm
->owner
== p
) {
4779 * We do all the move charge works under one mmap_sem to
4780 * avoid deadlock with down_write(&mmap_sem)
4781 * -> try_charge() -> if (mc.moving_task) -> sleep.
4783 down_read(&mm
->mmap_sem
);
4787 VM_BUG_ON(mc
.precharge
);
4788 VM_BUG_ON(mc
.moved_charge
);
4789 VM_BUG_ON(mc
.moved_swap
);
4790 VM_BUG_ON(mc
.moving_task
);
4793 mem_cgroup_start_move(from
);
4794 spin_lock(&mc
.lock
);
4798 mc
.moved_charge
= 0;
4800 spin_unlock(&mc
.lock
);
4801 mc
.moving_task
= current
;
4804 ret
= mem_cgroup_precharge_mc(mm
);
4806 mem_cgroup_clear_mc();
4807 /* We call up_read() and mmput() in clear_mc(). */
4814 static void mem_cgroup_cancel_attach(struct cgroup_subsys
*ss
,
4815 struct cgroup
*cgroup
,
4816 struct task_struct
*p
,
4819 mem_cgroup_clear_mc();
4822 static int mem_cgroup_move_charge_pte_range(pmd_t
*pmd
,
4823 unsigned long addr
, unsigned long end
,
4824 struct mm_walk
*walk
)
4827 struct vm_area_struct
*vma
= walk
->private;
4832 VM_BUG_ON(pmd_trans_huge(*pmd
));
4833 pte
= pte_offset_map_lock(vma
->vm_mm
, pmd
, addr
, &ptl
);
4834 for (; addr
!= end
; addr
+= PAGE_SIZE
) {
4835 pte_t ptent
= *(pte
++);
4836 union mc_target target
;
4839 struct page_cgroup
*pc
;
4845 type
= is_target_pte_for_mc(vma
, addr
, ptent
, &target
);
4847 case MC_TARGET_PAGE
:
4849 if (isolate_lru_page(page
))
4851 pc
= lookup_page_cgroup(page
);
4852 if (!mem_cgroup_move_account(pc
,
4853 mc
.from
, mc
.to
, false)) {
4855 /* we uncharge from mc.from later. */
4858 putback_lru_page(page
);
4859 put
: /* is_target_pte_for_mc() gets the page */
4862 case MC_TARGET_SWAP
:
4864 if (!mem_cgroup_move_swap_account(ent
,
4865 mc
.from
, mc
.to
, false)) {
4867 /* we fixup refcnts and charges later. */
4875 pte_unmap_unlock(pte
- 1, ptl
);
4880 * We have consumed all precharges we got in can_attach().
4881 * We try charge one by one, but don't do any additional
4882 * charges to mc.to if we have failed in charge once in attach()
4885 ret
= mem_cgroup_do_precharge(1);
4893 static void mem_cgroup_move_charge(struct mm_struct
*mm
)
4895 struct vm_area_struct
*vma
;
4897 lru_add_drain_all();
4898 /* We've already held the mmap_sem */
4899 for (vma
= mm
->mmap
; vma
; vma
= vma
->vm_next
) {
4901 struct mm_walk mem_cgroup_move_charge_walk
= {
4902 .pmd_entry
= mem_cgroup_move_charge_pte_range
,
4906 if (is_vm_hugetlb_page(vma
))
4908 ret
= walk_page_range(vma
->vm_start
, vma
->vm_end
,
4909 &mem_cgroup_move_charge_walk
);
4912 * means we have consumed all precharges and failed in
4913 * doing additional charge. Just abandon here.
4919 static void mem_cgroup_move_task(struct cgroup_subsys
*ss
,
4920 struct cgroup
*cont
,
4921 struct cgroup
*old_cont
,
4922 struct task_struct
*p
,
4926 /* no need to move charge */
4929 mem_cgroup_move_charge(mc
.mm
);
4930 mem_cgroup_clear_mc();
4932 #else /* !CONFIG_MMU */
4933 static int mem_cgroup_can_attach(struct cgroup_subsys
*ss
,
4934 struct cgroup
*cgroup
,
4935 struct task_struct
*p
,
4940 static void mem_cgroup_cancel_attach(struct cgroup_subsys
*ss
,
4941 struct cgroup
*cgroup
,
4942 struct task_struct
*p
,
4946 static void mem_cgroup_move_task(struct cgroup_subsys
*ss
,
4947 struct cgroup
*cont
,
4948 struct cgroup
*old_cont
,
4949 struct task_struct
*p
,
4955 struct cgroup_subsys mem_cgroup_subsys
= {
4957 .subsys_id
= mem_cgroup_subsys_id
,
4958 .create
= mem_cgroup_create
,
4959 .pre_destroy
= mem_cgroup_pre_destroy
,
4960 .destroy
= mem_cgroup_destroy
,
4961 .populate
= mem_cgroup_populate
,
4962 .can_attach
= mem_cgroup_can_attach
,
4963 .cancel_attach
= mem_cgroup_cancel_attach
,
4964 .attach
= mem_cgroup_move_task
,
4969 #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP
4970 static int __init
enable_swap_account(char *s
)
4972 /* consider enabled if no parameter or 1 is given */
4973 if (!s
|| !strcmp(s
, "1"))
4974 really_do_swap_account
= 1;
4975 else if (!strcmp(s
, "0"))
4976 really_do_swap_account
= 0;
4979 __setup("swapaccount", enable_swap_account
);
4981 static int __init
disable_swap_account(char *s
)
4983 enable_swap_account("0");
4986 __setup("noswapaccount", disable_swap_account
);