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>
52 #include <asm/uaccess.h>
54 struct cgroup_subsys mem_cgroup_subsys __read_mostly
;
55 #define MEM_CGROUP_RECLAIM_RETRIES 5
56 struct mem_cgroup
*root_mem_cgroup __read_mostly
;
58 #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP
59 /* Turned on only when memory cgroup is enabled && really_do_swap_account = 1 */
60 int do_swap_account __read_mostly
;
61 static int really_do_swap_account __initdata
= 1; /* for remember boot option*/
63 #define do_swap_account (0)
67 * Per memcg event counter is incremented at every pagein/pageout. This counter
68 * is used for trigger some periodic events. This is straightforward and better
69 * than using jiffies etc. to handle periodic memcg event.
71 * These values will be used as !((event) & ((1 <<(thresh)) - 1))
73 #define THRESHOLDS_EVENTS_THRESH (7) /* once in 128 */
74 #define SOFTLIMIT_EVENTS_THRESH (10) /* once in 1024 */
77 * Statistics for memory cgroup.
79 enum mem_cgroup_stat_index
{
81 * For MEM_CONTAINER_TYPE_ALL, usage = pagecache + rss.
83 MEM_CGROUP_STAT_CACHE
, /* # of pages charged as cache */
84 MEM_CGROUP_STAT_RSS
, /* # of pages charged as anon rss */
85 MEM_CGROUP_STAT_FILE_MAPPED
, /* # of pages charged as file rss */
86 MEM_CGROUP_STAT_PGPGIN_COUNT
, /* # of pages paged in */
87 MEM_CGROUP_STAT_PGPGOUT_COUNT
, /* # of pages paged out */
88 MEM_CGROUP_STAT_SWAPOUT
, /* # of pages, swapped out */
89 MEM_CGROUP_EVENTS
, /* incremented at every pagein/pageout */
91 MEM_CGROUP_STAT_NSTATS
,
94 struct mem_cgroup_stat_cpu
{
95 s64 count
[MEM_CGROUP_STAT_NSTATS
];
99 * per-zone information in memory controller.
101 struct mem_cgroup_per_zone
{
103 * spin_lock to protect the per cgroup LRU
105 struct list_head lists
[NR_LRU_LISTS
];
106 unsigned long count
[NR_LRU_LISTS
];
108 struct zone_reclaim_stat reclaim_stat
;
109 struct rb_node tree_node
; /* RB tree node */
110 unsigned long long usage_in_excess
;/* Set to the value by which */
111 /* the soft limit is exceeded*/
113 struct mem_cgroup
*mem
; /* Back pointer, we cannot */
114 /* use container_of */
116 /* Macro for accessing counter */
117 #define MEM_CGROUP_ZSTAT(mz, idx) ((mz)->count[(idx)])
119 struct mem_cgroup_per_node
{
120 struct mem_cgroup_per_zone zoneinfo
[MAX_NR_ZONES
];
123 struct mem_cgroup_lru_info
{
124 struct mem_cgroup_per_node
*nodeinfo
[MAX_NUMNODES
];
128 * Cgroups above their limits are maintained in a RB-Tree, independent of
129 * their hierarchy representation
132 struct mem_cgroup_tree_per_zone
{
133 struct rb_root rb_root
;
137 struct mem_cgroup_tree_per_node
{
138 struct mem_cgroup_tree_per_zone rb_tree_per_zone
[MAX_NR_ZONES
];
141 struct mem_cgroup_tree
{
142 struct mem_cgroup_tree_per_node
*rb_tree_per_node
[MAX_NUMNODES
];
145 static struct mem_cgroup_tree soft_limit_tree __read_mostly
;
147 struct mem_cgroup_threshold
{
148 struct eventfd_ctx
*eventfd
;
152 struct mem_cgroup_threshold_ary
{
153 /* An array index points to threshold just below usage. */
154 atomic_t current_threshold
;
155 /* Size of entries[] */
157 /* Array of thresholds */
158 struct mem_cgroup_threshold entries
[0];
161 static void mem_cgroup_threshold(struct mem_cgroup
*mem
);
164 * The memory controller data structure. The memory controller controls both
165 * page cache and RSS per cgroup. We would eventually like to provide
166 * statistics based on the statistics developed by Rik Van Riel for clock-pro,
167 * to help the administrator determine what knobs to tune.
169 * TODO: Add a water mark for the memory controller. Reclaim will begin when
170 * we hit the water mark. May be even add a low water mark, such that
171 * no reclaim occurs from a cgroup at it's low water mark, this is
172 * a feature that will be implemented much later in the future.
175 struct cgroup_subsys_state css
;
177 * the counter to account for memory usage
179 struct res_counter res
;
181 * the counter to account for mem+swap usage.
183 struct res_counter memsw
;
185 * Per cgroup active and inactive list, similar to the
186 * per zone LRU lists.
188 struct mem_cgroup_lru_info info
;
191 protect against reclaim related member.
193 spinlock_t reclaim_param_lock
;
195 int prev_priority
; /* for recording reclaim priority */
198 * While reclaiming in a hierarchy, we cache the last child we
201 int last_scanned_child
;
203 * Should the accounting and control be hierarchical, per subtree?
206 unsigned long last_oom_jiffies
;
209 unsigned int swappiness
;
211 /* set when res.limit == memsw.limit */
212 bool memsw_is_minimum
;
214 /* protect arrays of thresholds */
215 struct mutex thresholds_lock
;
217 /* thresholds for memory usage. RCU-protected */
218 struct mem_cgroup_threshold_ary
*thresholds
;
220 /* thresholds for mem+swap usage. RCU-protected */
221 struct mem_cgroup_threshold_ary
*memsw_thresholds
;
224 * Should we move charges of a task when a task is moved into this
225 * mem_cgroup ? And what type of charges should we move ?
227 unsigned long move_charge_at_immigrate
;
232 struct mem_cgroup_stat_cpu
*stat
;
235 /* Stuffs for move charges at task migration. */
237 * Types of charges to be moved. "move_charge_at_immitgrate" is treated as a
238 * left-shifted bitmap of these types.
241 MOVE_CHARGE_TYPE_ANON
, /* private anonymous page and swap of it */
245 /* "mc" and its members are protected by cgroup_mutex */
246 static struct move_charge_struct
{
247 struct mem_cgroup
*from
;
248 struct mem_cgroup
*to
;
249 unsigned long precharge
;
250 unsigned long moved_charge
;
251 unsigned long moved_swap
;
252 struct task_struct
*moving_task
; /* a task moving charges */
253 wait_queue_head_t waitq
; /* a waitq for other context */
255 .waitq
= __WAIT_QUEUE_HEAD_INITIALIZER(mc
.waitq
),
259 * Maximum loops in mem_cgroup_hierarchical_reclaim(), used for soft
260 * limit reclaim to prevent infinite loops, if they ever occur.
262 #define MEM_CGROUP_MAX_RECLAIM_LOOPS (100)
263 #define MEM_CGROUP_MAX_SOFT_LIMIT_RECLAIM_LOOPS (2)
266 MEM_CGROUP_CHARGE_TYPE_CACHE
= 0,
267 MEM_CGROUP_CHARGE_TYPE_MAPPED
,
268 MEM_CGROUP_CHARGE_TYPE_SHMEM
, /* used by page migration of shmem */
269 MEM_CGROUP_CHARGE_TYPE_FORCE
, /* used by force_empty */
270 MEM_CGROUP_CHARGE_TYPE_SWAPOUT
, /* for accounting swapcache */
271 MEM_CGROUP_CHARGE_TYPE_DROP
, /* a page was unused swap cache */
275 /* only for here (for easy reading.) */
276 #define PCGF_CACHE (1UL << PCG_CACHE)
277 #define PCGF_USED (1UL << PCG_USED)
278 #define PCGF_LOCK (1UL << PCG_LOCK)
279 /* Not used, but added here for completeness */
280 #define PCGF_ACCT (1UL << PCG_ACCT)
282 /* for encoding cft->private value on file */
285 #define MEMFILE_PRIVATE(x, val) (((x) << 16) | (val))
286 #define MEMFILE_TYPE(val) (((val) >> 16) & 0xffff)
287 #define MEMFILE_ATTR(val) ((val) & 0xffff)
290 * Reclaim flags for mem_cgroup_hierarchical_reclaim
292 #define MEM_CGROUP_RECLAIM_NOSWAP_BIT 0x0
293 #define MEM_CGROUP_RECLAIM_NOSWAP (1 << MEM_CGROUP_RECLAIM_NOSWAP_BIT)
294 #define MEM_CGROUP_RECLAIM_SHRINK_BIT 0x1
295 #define MEM_CGROUP_RECLAIM_SHRINK (1 << MEM_CGROUP_RECLAIM_SHRINK_BIT)
296 #define MEM_CGROUP_RECLAIM_SOFT_BIT 0x2
297 #define MEM_CGROUP_RECLAIM_SOFT (1 << MEM_CGROUP_RECLAIM_SOFT_BIT)
299 static void mem_cgroup_get(struct mem_cgroup
*mem
);
300 static void mem_cgroup_put(struct mem_cgroup
*mem
);
301 static struct mem_cgroup
*parent_mem_cgroup(struct mem_cgroup
*mem
);
302 static void drain_all_stock_async(void);
304 static struct mem_cgroup_per_zone
*
305 mem_cgroup_zoneinfo(struct mem_cgroup
*mem
, int nid
, int zid
)
307 return &mem
->info
.nodeinfo
[nid
]->zoneinfo
[zid
];
310 struct cgroup_subsys_state
*mem_cgroup_css(struct mem_cgroup
*mem
)
315 static struct mem_cgroup_per_zone
*
316 page_cgroup_zoneinfo(struct page_cgroup
*pc
)
318 struct mem_cgroup
*mem
= pc
->mem_cgroup
;
319 int nid
= page_cgroup_nid(pc
);
320 int zid
= page_cgroup_zid(pc
);
325 return mem_cgroup_zoneinfo(mem
, nid
, zid
);
328 static struct mem_cgroup_tree_per_zone
*
329 soft_limit_tree_node_zone(int nid
, int zid
)
331 return &soft_limit_tree
.rb_tree_per_node
[nid
]->rb_tree_per_zone
[zid
];
334 static struct mem_cgroup_tree_per_zone
*
335 soft_limit_tree_from_page(struct page
*page
)
337 int nid
= page_to_nid(page
);
338 int zid
= page_zonenum(page
);
340 return &soft_limit_tree
.rb_tree_per_node
[nid
]->rb_tree_per_zone
[zid
];
344 __mem_cgroup_insert_exceeded(struct mem_cgroup
*mem
,
345 struct mem_cgroup_per_zone
*mz
,
346 struct mem_cgroup_tree_per_zone
*mctz
,
347 unsigned long long new_usage_in_excess
)
349 struct rb_node
**p
= &mctz
->rb_root
.rb_node
;
350 struct rb_node
*parent
= NULL
;
351 struct mem_cgroup_per_zone
*mz_node
;
356 mz
->usage_in_excess
= new_usage_in_excess
;
357 if (!mz
->usage_in_excess
)
361 mz_node
= rb_entry(parent
, struct mem_cgroup_per_zone
,
363 if (mz
->usage_in_excess
< mz_node
->usage_in_excess
)
366 * We can't avoid mem cgroups that are over their soft
367 * limit by the same amount
369 else if (mz
->usage_in_excess
>= mz_node
->usage_in_excess
)
372 rb_link_node(&mz
->tree_node
, parent
, p
);
373 rb_insert_color(&mz
->tree_node
, &mctz
->rb_root
);
378 __mem_cgroup_remove_exceeded(struct mem_cgroup
*mem
,
379 struct mem_cgroup_per_zone
*mz
,
380 struct mem_cgroup_tree_per_zone
*mctz
)
384 rb_erase(&mz
->tree_node
, &mctz
->rb_root
);
389 mem_cgroup_remove_exceeded(struct mem_cgroup
*mem
,
390 struct mem_cgroup_per_zone
*mz
,
391 struct mem_cgroup_tree_per_zone
*mctz
)
393 spin_lock(&mctz
->lock
);
394 __mem_cgroup_remove_exceeded(mem
, mz
, mctz
);
395 spin_unlock(&mctz
->lock
);
399 static void mem_cgroup_update_tree(struct mem_cgroup
*mem
, struct page
*page
)
401 unsigned long long excess
;
402 struct mem_cgroup_per_zone
*mz
;
403 struct mem_cgroup_tree_per_zone
*mctz
;
404 int nid
= page_to_nid(page
);
405 int zid
= page_zonenum(page
);
406 mctz
= soft_limit_tree_from_page(page
);
409 * Necessary to update all ancestors when hierarchy is used.
410 * because their event counter is not touched.
412 for (; mem
; mem
= parent_mem_cgroup(mem
)) {
413 mz
= mem_cgroup_zoneinfo(mem
, nid
, zid
);
414 excess
= res_counter_soft_limit_excess(&mem
->res
);
416 * We have to update the tree if mz is on RB-tree or
417 * mem is over its softlimit.
419 if (excess
|| mz
->on_tree
) {
420 spin_lock(&mctz
->lock
);
421 /* if on-tree, remove it */
423 __mem_cgroup_remove_exceeded(mem
, mz
, mctz
);
425 * Insert again. mz->usage_in_excess will be updated.
426 * If excess is 0, no tree ops.
428 __mem_cgroup_insert_exceeded(mem
, mz
, mctz
, excess
);
429 spin_unlock(&mctz
->lock
);
434 static void mem_cgroup_remove_from_trees(struct mem_cgroup
*mem
)
437 struct mem_cgroup_per_zone
*mz
;
438 struct mem_cgroup_tree_per_zone
*mctz
;
440 for_each_node_state(node
, N_POSSIBLE
) {
441 for (zone
= 0; zone
< MAX_NR_ZONES
; zone
++) {
442 mz
= mem_cgroup_zoneinfo(mem
, node
, zone
);
443 mctz
= soft_limit_tree_node_zone(node
, zone
);
444 mem_cgroup_remove_exceeded(mem
, mz
, mctz
);
449 static inline unsigned long mem_cgroup_get_excess(struct mem_cgroup
*mem
)
451 return res_counter_soft_limit_excess(&mem
->res
) >> PAGE_SHIFT
;
454 static struct mem_cgroup_per_zone
*
455 __mem_cgroup_largest_soft_limit_node(struct mem_cgroup_tree_per_zone
*mctz
)
457 struct rb_node
*rightmost
= NULL
;
458 struct mem_cgroup_per_zone
*mz
;
462 rightmost
= rb_last(&mctz
->rb_root
);
464 goto done
; /* Nothing to reclaim from */
466 mz
= rb_entry(rightmost
, struct mem_cgroup_per_zone
, tree_node
);
468 * Remove the node now but someone else can add it back,
469 * we will to add it back at the end of reclaim to its correct
470 * position in the tree.
472 __mem_cgroup_remove_exceeded(mz
->mem
, mz
, mctz
);
473 if (!res_counter_soft_limit_excess(&mz
->mem
->res
) ||
474 !css_tryget(&mz
->mem
->css
))
480 static struct mem_cgroup_per_zone
*
481 mem_cgroup_largest_soft_limit_node(struct mem_cgroup_tree_per_zone
*mctz
)
483 struct mem_cgroup_per_zone
*mz
;
485 spin_lock(&mctz
->lock
);
486 mz
= __mem_cgroup_largest_soft_limit_node(mctz
);
487 spin_unlock(&mctz
->lock
);
491 static s64
mem_cgroup_read_stat(struct mem_cgroup
*mem
,
492 enum mem_cgroup_stat_index idx
)
497 for_each_possible_cpu(cpu
)
498 val
+= per_cpu(mem
->stat
->count
[idx
], cpu
);
502 static s64
mem_cgroup_local_usage(struct mem_cgroup
*mem
)
506 ret
= mem_cgroup_read_stat(mem
, MEM_CGROUP_STAT_RSS
);
507 ret
+= mem_cgroup_read_stat(mem
, MEM_CGROUP_STAT_CACHE
);
511 static void mem_cgroup_swap_statistics(struct mem_cgroup
*mem
,
514 int val
= (charge
) ? 1 : -1;
515 this_cpu_add(mem
->stat
->count
[MEM_CGROUP_STAT_SWAPOUT
], val
);
518 static void mem_cgroup_charge_statistics(struct mem_cgroup
*mem
,
519 struct page_cgroup
*pc
,
522 int val
= (charge
) ? 1 : -1;
526 if (PageCgroupCache(pc
))
527 __this_cpu_add(mem
->stat
->count
[MEM_CGROUP_STAT_CACHE
], val
);
529 __this_cpu_add(mem
->stat
->count
[MEM_CGROUP_STAT_RSS
], val
);
532 __this_cpu_inc(mem
->stat
->count
[MEM_CGROUP_STAT_PGPGIN_COUNT
]);
534 __this_cpu_inc(mem
->stat
->count
[MEM_CGROUP_STAT_PGPGOUT_COUNT
]);
535 __this_cpu_inc(mem
->stat
->count
[MEM_CGROUP_EVENTS
]);
540 static unsigned long mem_cgroup_get_local_zonestat(struct mem_cgroup
*mem
,
544 struct mem_cgroup_per_zone
*mz
;
547 for_each_online_node(nid
)
548 for (zid
= 0; zid
< MAX_NR_ZONES
; zid
++) {
549 mz
= mem_cgroup_zoneinfo(mem
, nid
, zid
);
550 total
+= MEM_CGROUP_ZSTAT(mz
, idx
);
555 static bool __memcg_event_check(struct mem_cgroup
*mem
, int event_mask_shift
)
559 val
= this_cpu_read(mem
->stat
->count
[MEM_CGROUP_EVENTS
]);
561 return !(val
& ((1 << event_mask_shift
) - 1));
565 * Check events in order.
568 static void memcg_check_events(struct mem_cgroup
*mem
, struct page
*page
)
570 /* threshold event is triggered in finer grain than soft limit */
571 if (unlikely(__memcg_event_check(mem
, THRESHOLDS_EVENTS_THRESH
))) {
572 mem_cgroup_threshold(mem
);
573 if (unlikely(__memcg_event_check(mem
, SOFTLIMIT_EVENTS_THRESH
)))
574 mem_cgroup_update_tree(mem
, page
);
578 static struct mem_cgroup
*mem_cgroup_from_cont(struct cgroup
*cont
)
580 return container_of(cgroup_subsys_state(cont
,
581 mem_cgroup_subsys_id
), struct mem_cgroup
,
585 struct mem_cgroup
*mem_cgroup_from_task(struct task_struct
*p
)
588 * mm_update_next_owner() may clear mm->owner to NULL
589 * if it races with swapoff, page migration, etc.
590 * So this can be called with p == NULL.
595 return container_of(task_subsys_state(p
, mem_cgroup_subsys_id
),
596 struct mem_cgroup
, css
);
599 static struct mem_cgroup
*try_get_mem_cgroup_from_mm(struct mm_struct
*mm
)
601 struct mem_cgroup
*mem
= NULL
;
606 * Because we have no locks, mm->owner's may be being moved to other
607 * cgroup. We use css_tryget() here even if this looks
608 * pessimistic (rather than adding locks here).
612 mem
= mem_cgroup_from_task(rcu_dereference(mm
->owner
));
615 } while (!css_tryget(&mem
->css
));
621 * Call callback function against all cgroup under hierarchy tree.
623 static int mem_cgroup_walk_tree(struct mem_cgroup
*root
, void *data
,
624 int (*func
)(struct mem_cgroup
*, void *))
626 int found
, ret
, nextid
;
627 struct cgroup_subsys_state
*css
;
628 struct mem_cgroup
*mem
;
630 if (!root
->use_hierarchy
)
631 return (*func
)(root
, data
);
639 css
= css_get_next(&mem_cgroup_subsys
, nextid
, &root
->css
,
641 if (css
&& css_tryget(css
))
642 mem
= container_of(css
, struct mem_cgroup
, css
);
646 ret
= (*func
)(mem
, data
);
650 } while (!ret
&& css
);
655 static inline bool mem_cgroup_is_root(struct mem_cgroup
*mem
)
657 return (mem
== root_mem_cgroup
);
661 * Following LRU functions are allowed to be used without PCG_LOCK.
662 * Operations are called by routine of global LRU independently from memcg.
663 * What we have to take care of here is validness of pc->mem_cgroup.
665 * Changes to pc->mem_cgroup happens when
668 * In typical case, "charge" is done before add-to-lru. Exception is SwapCache.
669 * It is added to LRU before charge.
670 * If PCG_USED bit is not set, page_cgroup is not added to this private LRU.
671 * When moving account, the page is not on LRU. It's isolated.
674 void mem_cgroup_del_lru_list(struct page
*page
, enum lru_list lru
)
676 struct page_cgroup
*pc
;
677 struct mem_cgroup_per_zone
*mz
;
679 if (mem_cgroup_disabled())
681 pc
= lookup_page_cgroup(page
);
682 /* can happen while we handle swapcache. */
683 if (!TestClearPageCgroupAcctLRU(pc
))
685 VM_BUG_ON(!pc
->mem_cgroup
);
687 * We don't check PCG_USED bit. It's cleared when the "page" is finally
688 * removed from global LRU.
690 mz
= page_cgroup_zoneinfo(pc
);
691 MEM_CGROUP_ZSTAT(mz
, lru
) -= 1;
692 if (mem_cgroup_is_root(pc
->mem_cgroup
))
694 VM_BUG_ON(list_empty(&pc
->lru
));
695 list_del_init(&pc
->lru
);
699 void mem_cgroup_del_lru(struct page
*page
)
701 mem_cgroup_del_lru_list(page
, page_lru(page
));
704 void mem_cgroup_rotate_lru_list(struct page
*page
, enum lru_list lru
)
706 struct mem_cgroup_per_zone
*mz
;
707 struct page_cgroup
*pc
;
709 if (mem_cgroup_disabled())
712 pc
= lookup_page_cgroup(page
);
714 * Used bit is set without atomic ops but after smp_wmb().
715 * For making pc->mem_cgroup visible, insert smp_rmb() here.
718 /* unused or root page is not rotated. */
719 if (!PageCgroupUsed(pc
) || mem_cgroup_is_root(pc
->mem_cgroup
))
721 mz
= page_cgroup_zoneinfo(pc
);
722 list_move(&pc
->lru
, &mz
->lists
[lru
]);
725 void mem_cgroup_add_lru_list(struct page
*page
, enum lru_list lru
)
727 struct page_cgroup
*pc
;
728 struct mem_cgroup_per_zone
*mz
;
730 if (mem_cgroup_disabled())
732 pc
= lookup_page_cgroup(page
);
733 VM_BUG_ON(PageCgroupAcctLRU(pc
));
735 * Used bit is set without atomic ops but after smp_wmb().
736 * For making pc->mem_cgroup visible, insert smp_rmb() here.
739 if (!PageCgroupUsed(pc
))
742 mz
= page_cgroup_zoneinfo(pc
);
743 MEM_CGROUP_ZSTAT(mz
, lru
) += 1;
744 SetPageCgroupAcctLRU(pc
);
745 if (mem_cgroup_is_root(pc
->mem_cgroup
))
747 list_add(&pc
->lru
, &mz
->lists
[lru
]);
751 * At handling SwapCache, pc->mem_cgroup may be changed while it's linked to
752 * lru because the page may.be reused after it's fully uncharged (because of
753 * SwapCache behavior).To handle that, unlink page_cgroup from LRU when charge
754 * it again. This function is only used to charge SwapCache. It's done under
755 * lock_page and expected that zone->lru_lock is never held.
757 static void mem_cgroup_lru_del_before_commit_swapcache(struct page
*page
)
760 struct zone
*zone
= page_zone(page
);
761 struct page_cgroup
*pc
= lookup_page_cgroup(page
);
763 spin_lock_irqsave(&zone
->lru_lock
, flags
);
765 * Forget old LRU when this page_cgroup is *not* used. This Used bit
766 * is guarded by lock_page() because the page is SwapCache.
768 if (!PageCgroupUsed(pc
))
769 mem_cgroup_del_lru_list(page
, page_lru(page
));
770 spin_unlock_irqrestore(&zone
->lru_lock
, flags
);
773 static void mem_cgroup_lru_add_after_commit_swapcache(struct page
*page
)
776 struct zone
*zone
= page_zone(page
);
777 struct page_cgroup
*pc
= lookup_page_cgroup(page
);
779 spin_lock_irqsave(&zone
->lru_lock
, flags
);
780 /* link when the page is linked to LRU but page_cgroup isn't */
781 if (PageLRU(page
) && !PageCgroupAcctLRU(pc
))
782 mem_cgroup_add_lru_list(page
, page_lru(page
));
783 spin_unlock_irqrestore(&zone
->lru_lock
, flags
);
787 void mem_cgroup_move_lists(struct page
*page
,
788 enum lru_list from
, enum lru_list to
)
790 if (mem_cgroup_disabled())
792 mem_cgroup_del_lru_list(page
, from
);
793 mem_cgroup_add_lru_list(page
, to
);
796 int task_in_mem_cgroup(struct task_struct
*task
, const struct mem_cgroup
*mem
)
799 struct mem_cgroup
*curr
= NULL
;
803 curr
= try_get_mem_cgroup_from_mm(task
->mm
);
809 * We should check use_hierarchy of "mem" not "curr". Because checking
810 * use_hierarchy of "curr" here make this function true if hierarchy is
811 * enabled in "curr" and "curr" is a child of "mem" in *cgroup*
812 * hierarchy(even if use_hierarchy is disabled in "mem").
814 if (mem
->use_hierarchy
)
815 ret
= css_is_ancestor(&curr
->css
, &mem
->css
);
823 * prev_priority control...this will be used in memory reclaim path.
825 int mem_cgroup_get_reclaim_priority(struct mem_cgroup
*mem
)
829 spin_lock(&mem
->reclaim_param_lock
);
830 prev_priority
= mem
->prev_priority
;
831 spin_unlock(&mem
->reclaim_param_lock
);
833 return prev_priority
;
836 void mem_cgroup_note_reclaim_priority(struct mem_cgroup
*mem
, int priority
)
838 spin_lock(&mem
->reclaim_param_lock
);
839 if (priority
< mem
->prev_priority
)
840 mem
->prev_priority
= priority
;
841 spin_unlock(&mem
->reclaim_param_lock
);
844 void mem_cgroup_record_reclaim_priority(struct mem_cgroup
*mem
, int priority
)
846 spin_lock(&mem
->reclaim_param_lock
);
847 mem
->prev_priority
= priority
;
848 spin_unlock(&mem
->reclaim_param_lock
);
851 static int calc_inactive_ratio(struct mem_cgroup
*memcg
, unsigned long *present_pages
)
853 unsigned long active
;
854 unsigned long inactive
;
856 unsigned long inactive_ratio
;
858 inactive
= mem_cgroup_get_local_zonestat(memcg
, LRU_INACTIVE_ANON
);
859 active
= mem_cgroup_get_local_zonestat(memcg
, LRU_ACTIVE_ANON
);
861 gb
= (inactive
+ active
) >> (30 - PAGE_SHIFT
);
863 inactive_ratio
= int_sqrt(10 * gb
);
868 present_pages
[0] = inactive
;
869 present_pages
[1] = active
;
872 return inactive_ratio
;
875 int mem_cgroup_inactive_anon_is_low(struct mem_cgroup
*memcg
)
877 unsigned long active
;
878 unsigned long inactive
;
879 unsigned long present_pages
[2];
880 unsigned long inactive_ratio
;
882 inactive_ratio
= calc_inactive_ratio(memcg
, present_pages
);
884 inactive
= present_pages
[0];
885 active
= present_pages
[1];
887 if (inactive
* inactive_ratio
< active
)
893 int mem_cgroup_inactive_file_is_low(struct mem_cgroup
*memcg
)
895 unsigned long active
;
896 unsigned long inactive
;
898 inactive
= mem_cgroup_get_local_zonestat(memcg
, LRU_INACTIVE_FILE
);
899 active
= mem_cgroup_get_local_zonestat(memcg
, LRU_ACTIVE_FILE
);
901 return (active
> inactive
);
904 unsigned long mem_cgroup_zone_nr_pages(struct mem_cgroup
*memcg
,
908 int nid
= zone
->zone_pgdat
->node_id
;
909 int zid
= zone_idx(zone
);
910 struct mem_cgroup_per_zone
*mz
= mem_cgroup_zoneinfo(memcg
, nid
, zid
);
912 return MEM_CGROUP_ZSTAT(mz
, lru
);
915 struct zone_reclaim_stat
*mem_cgroup_get_reclaim_stat(struct mem_cgroup
*memcg
,
918 int nid
= zone
->zone_pgdat
->node_id
;
919 int zid
= zone_idx(zone
);
920 struct mem_cgroup_per_zone
*mz
= mem_cgroup_zoneinfo(memcg
, nid
, zid
);
922 return &mz
->reclaim_stat
;
925 struct zone_reclaim_stat
*
926 mem_cgroup_get_reclaim_stat_from_page(struct page
*page
)
928 struct page_cgroup
*pc
;
929 struct mem_cgroup_per_zone
*mz
;
931 if (mem_cgroup_disabled())
934 pc
= lookup_page_cgroup(page
);
936 * Used bit is set without atomic ops but after smp_wmb().
937 * For making pc->mem_cgroup visible, insert smp_rmb() here.
940 if (!PageCgroupUsed(pc
))
943 mz
= page_cgroup_zoneinfo(pc
);
947 return &mz
->reclaim_stat
;
950 unsigned long mem_cgroup_isolate_pages(unsigned long nr_to_scan
,
951 struct list_head
*dst
,
952 unsigned long *scanned
, int order
,
953 int mode
, struct zone
*z
,
954 struct mem_cgroup
*mem_cont
,
955 int active
, int file
)
957 unsigned long nr_taken
= 0;
961 struct list_head
*src
;
962 struct page_cgroup
*pc
, *tmp
;
963 int nid
= z
->zone_pgdat
->node_id
;
964 int zid
= zone_idx(z
);
965 struct mem_cgroup_per_zone
*mz
;
966 int lru
= LRU_FILE
* file
+ active
;
970 mz
= mem_cgroup_zoneinfo(mem_cont
, nid
, zid
);
971 src
= &mz
->lists
[lru
];
974 list_for_each_entry_safe_reverse(pc
, tmp
, src
, lru
) {
975 if (scan
>= nr_to_scan
)
979 if (unlikely(!PageCgroupUsed(pc
)))
981 if (unlikely(!PageLRU(page
)))
985 ret
= __isolate_lru_page(page
, mode
, file
);
988 list_move(&page
->lru
, dst
);
989 mem_cgroup_del_lru(page
);
993 /* we don't affect global LRU but rotate in our LRU */
994 mem_cgroup_rotate_lru_list(page
, page_lru(page
));
1005 #define mem_cgroup_from_res_counter(counter, member) \
1006 container_of(counter, struct mem_cgroup, member)
1008 static bool mem_cgroup_check_under_limit(struct mem_cgroup
*mem
)
1010 if (do_swap_account
) {
1011 if (res_counter_check_under_limit(&mem
->res
) &&
1012 res_counter_check_under_limit(&mem
->memsw
))
1015 if (res_counter_check_under_limit(&mem
->res
))
1020 static unsigned int get_swappiness(struct mem_cgroup
*memcg
)
1022 struct cgroup
*cgrp
= memcg
->css
.cgroup
;
1023 unsigned int swappiness
;
1026 if (cgrp
->parent
== NULL
)
1027 return vm_swappiness
;
1029 spin_lock(&memcg
->reclaim_param_lock
);
1030 swappiness
= memcg
->swappiness
;
1031 spin_unlock(&memcg
->reclaim_param_lock
);
1036 static int mem_cgroup_count_children_cb(struct mem_cgroup
*mem
, void *data
)
1044 * mem_cgroup_print_oom_info: Called from OOM with tasklist_lock held in read mode.
1045 * @memcg: The memory cgroup that went over limit
1046 * @p: Task that is going to be killed
1048 * NOTE: @memcg and @p's mem_cgroup can be different when hierarchy is
1051 void mem_cgroup_print_oom_info(struct mem_cgroup
*memcg
, struct task_struct
*p
)
1053 struct cgroup
*task_cgrp
;
1054 struct cgroup
*mem_cgrp
;
1056 * Need a buffer in BSS, can't rely on allocations. The code relies
1057 * on the assumption that OOM is serialized for memory controller.
1058 * If this assumption is broken, revisit this code.
1060 static char memcg_name
[PATH_MAX
];
1069 mem_cgrp
= memcg
->css
.cgroup
;
1070 task_cgrp
= task_cgroup(p
, mem_cgroup_subsys_id
);
1072 ret
= cgroup_path(task_cgrp
, memcg_name
, PATH_MAX
);
1075 * Unfortunately, we are unable to convert to a useful name
1076 * But we'll still print out the usage information
1083 printk(KERN_INFO
"Task in %s killed", memcg_name
);
1086 ret
= cgroup_path(mem_cgrp
, memcg_name
, PATH_MAX
);
1094 * Continues from above, so we don't need an KERN_ level
1096 printk(KERN_CONT
" as a result of limit of %s\n", memcg_name
);
1099 printk(KERN_INFO
"memory: usage %llukB, limit %llukB, failcnt %llu\n",
1100 res_counter_read_u64(&memcg
->res
, RES_USAGE
) >> 10,
1101 res_counter_read_u64(&memcg
->res
, RES_LIMIT
) >> 10,
1102 res_counter_read_u64(&memcg
->res
, RES_FAILCNT
));
1103 printk(KERN_INFO
"memory+swap: usage %llukB, limit %llukB, "
1105 res_counter_read_u64(&memcg
->memsw
, RES_USAGE
) >> 10,
1106 res_counter_read_u64(&memcg
->memsw
, RES_LIMIT
) >> 10,
1107 res_counter_read_u64(&memcg
->memsw
, RES_FAILCNT
));
1111 * This function returns the number of memcg under hierarchy tree. Returns
1112 * 1(self count) if no children.
1114 static int mem_cgroup_count_children(struct mem_cgroup
*mem
)
1117 mem_cgroup_walk_tree(mem
, &num
, mem_cgroup_count_children_cb
);
1122 * Visit the first child (need not be the first child as per the ordering
1123 * of the cgroup list, since we track last_scanned_child) of @mem and use
1124 * that to reclaim free pages from.
1126 static struct mem_cgroup
*
1127 mem_cgroup_select_victim(struct mem_cgroup
*root_mem
)
1129 struct mem_cgroup
*ret
= NULL
;
1130 struct cgroup_subsys_state
*css
;
1133 if (!root_mem
->use_hierarchy
) {
1134 css_get(&root_mem
->css
);
1140 nextid
= root_mem
->last_scanned_child
+ 1;
1141 css
= css_get_next(&mem_cgroup_subsys
, nextid
, &root_mem
->css
,
1143 if (css
&& css_tryget(css
))
1144 ret
= container_of(css
, struct mem_cgroup
, css
);
1147 /* Updates scanning parameter */
1148 spin_lock(&root_mem
->reclaim_param_lock
);
1150 /* this means start scan from ID:1 */
1151 root_mem
->last_scanned_child
= 0;
1153 root_mem
->last_scanned_child
= found
;
1154 spin_unlock(&root_mem
->reclaim_param_lock
);
1161 * Scan the hierarchy if needed to reclaim memory. We remember the last child
1162 * we reclaimed from, so that we don't end up penalizing one child extensively
1163 * based on its position in the children list.
1165 * root_mem is the original ancestor that we've been reclaim from.
1167 * We give up and return to the caller when we visit root_mem twice.
1168 * (other groups can be removed while we're walking....)
1170 * If shrink==true, for avoiding to free too much, this returns immedieately.
1172 static int mem_cgroup_hierarchical_reclaim(struct mem_cgroup
*root_mem
,
1175 unsigned long reclaim_options
)
1177 struct mem_cgroup
*victim
;
1180 bool noswap
= reclaim_options
& MEM_CGROUP_RECLAIM_NOSWAP
;
1181 bool shrink
= reclaim_options
& MEM_CGROUP_RECLAIM_SHRINK
;
1182 bool check_soft
= reclaim_options
& MEM_CGROUP_RECLAIM_SOFT
;
1183 unsigned long excess
= mem_cgroup_get_excess(root_mem
);
1185 /* If memsw_is_minimum==1, swap-out is of-no-use. */
1186 if (root_mem
->memsw_is_minimum
)
1190 victim
= mem_cgroup_select_victim(root_mem
);
1191 if (victim
== root_mem
) {
1194 drain_all_stock_async();
1197 * If we have not been able to reclaim
1198 * anything, it might because there are
1199 * no reclaimable pages under this hierarchy
1201 if (!check_soft
|| !total
) {
1202 css_put(&victim
->css
);
1206 * We want to do more targetted reclaim.
1207 * excess >> 2 is not to excessive so as to
1208 * reclaim too much, nor too less that we keep
1209 * coming back to reclaim from this cgroup
1211 if (total
>= (excess
>> 2) ||
1212 (loop
> MEM_CGROUP_MAX_RECLAIM_LOOPS
)) {
1213 css_put(&victim
->css
);
1218 if (!mem_cgroup_local_usage(victim
)) {
1219 /* this cgroup's local usage == 0 */
1220 css_put(&victim
->css
);
1223 /* we use swappiness of local cgroup */
1225 ret
= mem_cgroup_shrink_node_zone(victim
, gfp_mask
,
1226 noswap
, get_swappiness(victim
), zone
,
1227 zone
->zone_pgdat
->node_id
);
1229 ret
= try_to_free_mem_cgroup_pages(victim
, gfp_mask
,
1230 noswap
, get_swappiness(victim
));
1231 css_put(&victim
->css
);
1233 * At shrinking usage, we can't check we should stop here or
1234 * reclaim more. It's depends on callers. last_scanned_child
1235 * will work enough for keeping fairness under tree.
1241 if (res_counter_check_under_soft_limit(&root_mem
->res
))
1243 } else if (mem_cgroup_check_under_limit(root_mem
))
1249 bool mem_cgroup_oom_called(struct task_struct
*task
)
1252 struct mem_cgroup
*mem
;
1253 struct mm_struct
*mm
;
1259 mem
= mem_cgroup_from_task(rcu_dereference(mm
->owner
));
1260 if (mem
&& time_before(jiffies
, mem
->last_oom_jiffies
+ HZ
/10))
1266 static int record_last_oom_cb(struct mem_cgroup
*mem
, void *data
)
1268 mem
->last_oom_jiffies
= jiffies
;
1272 static void record_last_oom(struct mem_cgroup
*mem
)
1274 mem_cgroup_walk_tree(mem
, NULL
, record_last_oom_cb
);
1278 * Currently used to update mapped file statistics, but the routine can be
1279 * generalized to update other statistics as well.
1281 void mem_cgroup_update_file_mapped(struct page
*page
, int val
)
1283 struct mem_cgroup
*mem
;
1284 struct page_cgroup
*pc
;
1286 pc
= lookup_page_cgroup(page
);
1290 lock_page_cgroup(pc
);
1291 mem
= pc
->mem_cgroup
;
1295 if (!PageCgroupUsed(pc
))
1299 * Preemption is already disabled. We can use __this_cpu_xxx
1301 __this_cpu_add(mem
->stat
->count
[MEM_CGROUP_STAT_FILE_MAPPED
], val
);
1304 unlock_page_cgroup(pc
);
1308 * size of first charge trial. "32" comes from vmscan.c's magic value.
1309 * TODO: maybe necessary to use big numbers in big irons.
1311 #define CHARGE_SIZE (32 * PAGE_SIZE)
1312 struct memcg_stock_pcp
{
1313 struct mem_cgroup
*cached
; /* this never be root cgroup */
1315 struct work_struct work
;
1317 static DEFINE_PER_CPU(struct memcg_stock_pcp
, memcg_stock
);
1318 static atomic_t memcg_drain_count
;
1321 * Try to consume stocked charge on this cpu. If success, PAGE_SIZE is consumed
1322 * from local stock and true is returned. If the stock is 0 or charges from a
1323 * cgroup which is not current target, returns false. This stock will be
1326 static bool consume_stock(struct mem_cgroup
*mem
)
1328 struct memcg_stock_pcp
*stock
;
1331 stock
= &get_cpu_var(memcg_stock
);
1332 if (mem
== stock
->cached
&& stock
->charge
)
1333 stock
->charge
-= PAGE_SIZE
;
1334 else /* need to call res_counter_charge */
1336 put_cpu_var(memcg_stock
);
1341 * Returns stocks cached in percpu to res_counter and reset cached information.
1343 static void drain_stock(struct memcg_stock_pcp
*stock
)
1345 struct mem_cgroup
*old
= stock
->cached
;
1347 if (stock
->charge
) {
1348 res_counter_uncharge(&old
->res
, stock
->charge
);
1349 if (do_swap_account
)
1350 res_counter_uncharge(&old
->memsw
, stock
->charge
);
1352 stock
->cached
= NULL
;
1357 * This must be called under preempt disabled or must be called by
1358 * a thread which is pinned to local cpu.
1360 static void drain_local_stock(struct work_struct
*dummy
)
1362 struct memcg_stock_pcp
*stock
= &__get_cpu_var(memcg_stock
);
1367 * Cache charges(val) which is from res_counter, to local per_cpu area.
1368 * This will be consumed by consumt_stock() function, later.
1370 static void refill_stock(struct mem_cgroup
*mem
, int val
)
1372 struct memcg_stock_pcp
*stock
= &get_cpu_var(memcg_stock
);
1374 if (stock
->cached
!= mem
) { /* reset if necessary */
1376 stock
->cached
= mem
;
1378 stock
->charge
+= val
;
1379 put_cpu_var(memcg_stock
);
1383 * Tries to drain stocked charges in other cpus. This function is asynchronous
1384 * and just put a work per cpu for draining localy on each cpu. Caller can
1385 * expects some charges will be back to res_counter later but cannot wait for
1388 static void drain_all_stock_async(void)
1391 /* This function is for scheduling "drain" in asynchronous way.
1392 * The result of "drain" is not directly handled by callers. Then,
1393 * if someone is calling drain, we don't have to call drain more.
1394 * Anyway, WORK_STRUCT_PENDING check in queue_work_on() will catch if
1395 * there is a race. We just do loose check here.
1397 if (atomic_read(&memcg_drain_count
))
1399 /* Notify other cpus that system-wide "drain" is running */
1400 atomic_inc(&memcg_drain_count
);
1402 for_each_online_cpu(cpu
) {
1403 struct memcg_stock_pcp
*stock
= &per_cpu(memcg_stock
, cpu
);
1404 schedule_work_on(cpu
, &stock
->work
);
1407 atomic_dec(&memcg_drain_count
);
1408 /* We don't wait for flush_work */
1411 /* This is a synchronous drain interface. */
1412 static void drain_all_stock_sync(void)
1414 /* called when force_empty is called */
1415 atomic_inc(&memcg_drain_count
);
1416 schedule_on_each_cpu(drain_local_stock
);
1417 atomic_dec(&memcg_drain_count
);
1420 static int __cpuinit
memcg_stock_cpu_callback(struct notifier_block
*nb
,
1421 unsigned long action
,
1424 int cpu
= (unsigned long)hcpu
;
1425 struct memcg_stock_pcp
*stock
;
1427 if (action
!= CPU_DEAD
)
1429 stock
= &per_cpu(memcg_stock
, cpu
);
1435 * Unlike exported interface, "oom" parameter is added. if oom==true,
1436 * oom-killer can be invoked.
1438 static int __mem_cgroup_try_charge(struct mm_struct
*mm
,
1439 gfp_t gfp_mask
, struct mem_cgroup
**memcg
, bool oom
)
1441 struct mem_cgroup
*mem
, *mem_over_limit
;
1442 int nr_retries
= MEM_CGROUP_RECLAIM_RETRIES
;
1443 struct res_counter
*fail_res
;
1444 int csize
= CHARGE_SIZE
;
1446 if (unlikely(test_thread_flag(TIF_MEMDIE
))) {
1447 /* Don't account this! */
1453 * We always charge the cgroup the mm_struct belongs to.
1454 * The mm_struct's mem_cgroup changes on task migration if the
1455 * thread group leader migrates. It's possible that mm is not
1456 * set, if so charge the init_mm (happens for pagecache usage).
1460 mem
= try_get_mem_cgroup_from_mm(mm
);
1468 VM_BUG_ON(css_is_removed(&mem
->css
));
1469 if (mem_cgroup_is_root(mem
))
1474 unsigned long flags
= 0;
1476 if (consume_stock(mem
))
1479 ret
= res_counter_charge(&mem
->res
, csize
, &fail_res
);
1481 if (!do_swap_account
)
1483 ret
= res_counter_charge(&mem
->memsw
, csize
, &fail_res
);
1486 /* mem+swap counter fails */
1487 res_counter_uncharge(&mem
->res
, csize
);
1488 flags
|= MEM_CGROUP_RECLAIM_NOSWAP
;
1489 mem_over_limit
= mem_cgroup_from_res_counter(fail_res
,
1492 /* mem counter fails */
1493 mem_over_limit
= mem_cgroup_from_res_counter(fail_res
,
1496 /* reduce request size and retry */
1497 if (csize
> PAGE_SIZE
) {
1501 if (!(gfp_mask
& __GFP_WAIT
))
1504 ret
= mem_cgroup_hierarchical_reclaim(mem_over_limit
, NULL
,
1510 * try_to_free_mem_cgroup_pages() might not give us a full
1511 * picture of reclaim. Some pages are reclaimed and might be
1512 * moved to swap cache or just unmapped from the cgroup.
1513 * Check the limit again to see if the reclaim reduced the
1514 * current usage of the cgroup before giving up
1517 if (mem_cgroup_check_under_limit(mem_over_limit
))
1520 /* try to avoid oom while someone is moving charge */
1521 if (mc
.moving_task
&& current
!= mc
.moving_task
) {
1522 struct mem_cgroup
*from
, *to
;
1523 bool do_continue
= false;
1525 * There is a small race that "from" or "to" can be
1526 * freed by rmdir, so we use css_tryget().
1531 if (from
&& css_tryget(&from
->css
)) {
1532 if (mem_over_limit
->use_hierarchy
)
1533 do_continue
= css_is_ancestor(
1535 &mem_over_limit
->css
);
1537 do_continue
= (from
== mem_over_limit
);
1538 css_put(&from
->css
);
1540 if (!do_continue
&& to
&& css_tryget(&to
->css
)) {
1541 if (mem_over_limit
->use_hierarchy
)
1542 do_continue
= css_is_ancestor(
1544 &mem_over_limit
->css
);
1546 do_continue
= (to
== mem_over_limit
);
1552 prepare_to_wait(&mc
.waitq
, &wait
,
1553 TASK_INTERRUPTIBLE
);
1554 /* moving charge context might have finished. */
1557 finish_wait(&mc
.waitq
, &wait
);
1562 if (!nr_retries
--) {
1564 mem_cgroup_out_of_memory(mem_over_limit
, gfp_mask
);
1565 record_last_oom(mem_over_limit
);
1570 if (csize
> PAGE_SIZE
)
1571 refill_stock(mem
, csize
- PAGE_SIZE
);
1580 * Somemtimes we have to undo a charge we got by try_charge().
1581 * This function is for that and do uncharge, put css's refcnt.
1582 * gotten by try_charge().
1584 static void __mem_cgroup_cancel_charge(struct mem_cgroup
*mem
,
1585 unsigned long count
)
1587 if (!mem_cgroup_is_root(mem
)) {
1588 res_counter_uncharge(&mem
->res
, PAGE_SIZE
* count
);
1589 if (do_swap_account
)
1590 res_counter_uncharge(&mem
->memsw
, PAGE_SIZE
* count
);
1591 VM_BUG_ON(test_bit(CSS_ROOT
, &mem
->css
.flags
));
1592 WARN_ON_ONCE(count
> INT_MAX
);
1593 __css_put(&mem
->css
, (int)count
);
1595 /* we don't need css_put for root */
1598 static void mem_cgroup_cancel_charge(struct mem_cgroup
*mem
)
1600 __mem_cgroup_cancel_charge(mem
, 1);
1604 * A helper function to get mem_cgroup from ID. must be called under
1605 * rcu_read_lock(). The caller must check css_is_removed() or some if
1606 * it's concern. (dropping refcnt from swap can be called against removed
1609 static struct mem_cgroup
*mem_cgroup_lookup(unsigned short id
)
1611 struct cgroup_subsys_state
*css
;
1613 /* ID 0 is unused ID */
1616 css
= css_lookup(&mem_cgroup_subsys
, id
);
1619 return container_of(css
, struct mem_cgroup
, css
);
1622 struct mem_cgroup
*try_get_mem_cgroup_from_page(struct page
*page
)
1624 struct mem_cgroup
*mem
= NULL
;
1625 struct page_cgroup
*pc
;
1629 VM_BUG_ON(!PageLocked(page
));
1631 pc
= lookup_page_cgroup(page
);
1632 lock_page_cgroup(pc
);
1633 if (PageCgroupUsed(pc
)) {
1634 mem
= pc
->mem_cgroup
;
1635 if (mem
&& !css_tryget(&mem
->css
))
1637 } else if (PageSwapCache(page
)) {
1638 ent
.val
= page_private(page
);
1639 id
= lookup_swap_cgroup(ent
);
1641 mem
= mem_cgroup_lookup(id
);
1642 if (mem
&& !css_tryget(&mem
->css
))
1646 unlock_page_cgroup(pc
);
1651 * commit a charge got by __mem_cgroup_try_charge() and makes page_cgroup to be
1652 * USED state. If already USED, uncharge and return.
1655 static void __mem_cgroup_commit_charge(struct mem_cgroup
*mem
,
1656 struct page_cgroup
*pc
,
1657 enum charge_type ctype
)
1659 /* try_charge() can return NULL to *memcg, taking care of it. */
1663 lock_page_cgroup(pc
);
1664 if (unlikely(PageCgroupUsed(pc
))) {
1665 unlock_page_cgroup(pc
);
1666 mem_cgroup_cancel_charge(mem
);
1670 pc
->mem_cgroup
= mem
;
1672 * We access a page_cgroup asynchronously without lock_page_cgroup().
1673 * Especially when a page_cgroup is taken from a page, pc->mem_cgroup
1674 * is accessed after testing USED bit. To make pc->mem_cgroup visible
1675 * before USED bit, we need memory barrier here.
1676 * See mem_cgroup_add_lru_list(), etc.
1680 case MEM_CGROUP_CHARGE_TYPE_CACHE
:
1681 case MEM_CGROUP_CHARGE_TYPE_SHMEM
:
1682 SetPageCgroupCache(pc
);
1683 SetPageCgroupUsed(pc
);
1685 case MEM_CGROUP_CHARGE_TYPE_MAPPED
:
1686 ClearPageCgroupCache(pc
);
1687 SetPageCgroupUsed(pc
);
1693 mem_cgroup_charge_statistics(mem
, pc
, true);
1695 unlock_page_cgroup(pc
);
1697 * "charge_statistics" updated event counter. Then, check it.
1698 * Insert ancestor (and ancestor's ancestors), to softlimit RB-tree.
1699 * if they exceeds softlimit.
1701 memcg_check_events(mem
, pc
->page
);
1705 * __mem_cgroup_move_account - move account of the page
1706 * @pc: page_cgroup of the page.
1707 * @from: mem_cgroup which the page is moved from.
1708 * @to: mem_cgroup which the page is moved to. @from != @to.
1709 * @uncharge: whether we should call uncharge and css_put against @from.
1711 * The caller must confirm following.
1712 * - page is not on LRU (isolate_page() is useful.)
1713 * - the pc is locked, used, and ->mem_cgroup points to @from.
1715 * This function doesn't do "charge" nor css_get to new cgroup. It should be
1716 * done by a caller(__mem_cgroup_try_charge would be usefull). If @uncharge is
1717 * true, this function does "uncharge" from old cgroup, but it doesn't if
1718 * @uncharge is false, so a caller should do "uncharge".
1721 static void __mem_cgroup_move_account(struct page_cgroup
*pc
,
1722 struct mem_cgroup
*from
, struct mem_cgroup
*to
, bool uncharge
)
1726 VM_BUG_ON(from
== to
);
1727 VM_BUG_ON(PageLRU(pc
->page
));
1728 VM_BUG_ON(!PageCgroupLocked(pc
));
1729 VM_BUG_ON(!PageCgroupUsed(pc
));
1730 VM_BUG_ON(pc
->mem_cgroup
!= from
);
1733 if (page_mapped(page
) && !PageAnon(page
)) {
1734 /* Update mapped_file data for mem_cgroup */
1736 __this_cpu_dec(from
->stat
->count
[MEM_CGROUP_STAT_FILE_MAPPED
]);
1737 __this_cpu_inc(to
->stat
->count
[MEM_CGROUP_STAT_FILE_MAPPED
]);
1740 mem_cgroup_charge_statistics(from
, pc
, false);
1742 /* This is not "cancel", but cancel_charge does all we need. */
1743 mem_cgroup_cancel_charge(from
);
1745 /* caller should have done css_get */
1746 pc
->mem_cgroup
= to
;
1747 mem_cgroup_charge_statistics(to
, pc
, true);
1749 * We charges against "to" which may not have any tasks. Then, "to"
1750 * can be under rmdir(). But in current implementation, caller of
1751 * this function is just force_empty() and move charge, so it's
1752 * garanteed that "to" is never removed. So, we don't check rmdir
1758 * check whether the @pc is valid for moving account and call
1759 * __mem_cgroup_move_account()
1761 static int mem_cgroup_move_account(struct page_cgroup
*pc
,
1762 struct mem_cgroup
*from
, struct mem_cgroup
*to
, bool uncharge
)
1765 lock_page_cgroup(pc
);
1766 if (PageCgroupUsed(pc
) && pc
->mem_cgroup
== from
) {
1767 __mem_cgroup_move_account(pc
, from
, to
, uncharge
);
1770 unlock_page_cgroup(pc
);
1774 memcg_check_events(to
, pc
->page
);
1775 memcg_check_events(from
, pc
->page
);
1780 * move charges to its parent.
1783 static int mem_cgroup_move_parent(struct page_cgroup
*pc
,
1784 struct mem_cgroup
*child
,
1787 struct page
*page
= pc
->page
;
1788 struct cgroup
*cg
= child
->css
.cgroup
;
1789 struct cgroup
*pcg
= cg
->parent
;
1790 struct mem_cgroup
*parent
;
1798 if (!get_page_unless_zero(page
))
1800 if (isolate_lru_page(page
))
1803 parent
= mem_cgroup_from_cont(pcg
);
1804 ret
= __mem_cgroup_try_charge(NULL
, gfp_mask
, &parent
, false);
1808 ret
= mem_cgroup_move_account(pc
, child
, parent
, true);
1810 mem_cgroup_cancel_charge(parent
);
1812 putback_lru_page(page
);
1820 * Charge the memory controller for page usage.
1822 * 0 if the charge was successful
1823 * < 0 if the cgroup is over its limit
1825 static int mem_cgroup_charge_common(struct page
*page
, struct mm_struct
*mm
,
1826 gfp_t gfp_mask
, enum charge_type ctype
,
1827 struct mem_cgroup
*memcg
)
1829 struct mem_cgroup
*mem
;
1830 struct page_cgroup
*pc
;
1833 pc
= lookup_page_cgroup(page
);
1834 /* can happen at boot */
1840 ret
= __mem_cgroup_try_charge(mm
, gfp_mask
, &mem
, true);
1844 __mem_cgroup_commit_charge(mem
, pc
, ctype
);
1848 int mem_cgroup_newpage_charge(struct page
*page
,
1849 struct mm_struct
*mm
, gfp_t gfp_mask
)
1851 if (mem_cgroup_disabled())
1853 if (PageCompound(page
))
1856 * If already mapped, we don't have to account.
1857 * If page cache, page->mapping has address_space.
1858 * But page->mapping may have out-of-use anon_vma pointer,
1859 * detecit it by PageAnon() check. newly-mapped-anon's page->mapping
1862 if (page_mapped(page
) || (page
->mapping
&& !PageAnon(page
)))
1866 return mem_cgroup_charge_common(page
, mm
, gfp_mask
,
1867 MEM_CGROUP_CHARGE_TYPE_MAPPED
, NULL
);
1871 __mem_cgroup_commit_charge_swapin(struct page
*page
, struct mem_cgroup
*ptr
,
1872 enum charge_type ctype
);
1874 int mem_cgroup_cache_charge(struct page
*page
, struct mm_struct
*mm
,
1877 struct mem_cgroup
*mem
= NULL
;
1880 if (mem_cgroup_disabled())
1882 if (PageCompound(page
))
1885 * Corner case handling. This is called from add_to_page_cache()
1886 * in usual. But some FS (shmem) precharges this page before calling it
1887 * and call add_to_page_cache() with GFP_NOWAIT.
1889 * For GFP_NOWAIT case, the page may be pre-charged before calling
1890 * add_to_page_cache(). (See shmem.c) check it here and avoid to call
1891 * charge twice. (It works but has to pay a bit larger cost.)
1892 * And when the page is SwapCache, it should take swap information
1893 * into account. This is under lock_page() now.
1895 if (!(gfp_mask
& __GFP_WAIT
)) {
1896 struct page_cgroup
*pc
;
1899 pc
= lookup_page_cgroup(page
);
1902 lock_page_cgroup(pc
);
1903 if (PageCgroupUsed(pc
)) {
1904 unlock_page_cgroup(pc
);
1907 unlock_page_cgroup(pc
);
1910 if (unlikely(!mm
&& !mem
))
1913 if (page_is_file_cache(page
))
1914 return mem_cgroup_charge_common(page
, mm
, gfp_mask
,
1915 MEM_CGROUP_CHARGE_TYPE_CACHE
, NULL
);
1918 if (PageSwapCache(page
)) {
1919 ret
= mem_cgroup_try_charge_swapin(mm
, page
, gfp_mask
, &mem
);
1921 __mem_cgroup_commit_charge_swapin(page
, mem
,
1922 MEM_CGROUP_CHARGE_TYPE_SHMEM
);
1924 ret
= mem_cgroup_charge_common(page
, mm
, gfp_mask
,
1925 MEM_CGROUP_CHARGE_TYPE_SHMEM
, mem
);
1931 * While swap-in, try_charge -> commit or cancel, the page is locked.
1932 * And when try_charge() successfully returns, one refcnt to memcg without
1933 * struct page_cgroup is acquired. This refcnt will be consumed by
1934 * "commit()" or removed by "cancel()"
1936 int mem_cgroup_try_charge_swapin(struct mm_struct
*mm
,
1938 gfp_t mask
, struct mem_cgroup
**ptr
)
1940 struct mem_cgroup
*mem
;
1943 if (mem_cgroup_disabled())
1946 if (!do_swap_account
)
1949 * A racing thread's fault, or swapoff, may have already updated
1950 * the pte, and even removed page from swap cache: in those cases
1951 * do_swap_page()'s pte_same() test will fail; but there's also a
1952 * KSM case which does need to charge the page.
1954 if (!PageSwapCache(page
))
1956 mem
= try_get_mem_cgroup_from_page(page
);
1960 ret
= __mem_cgroup_try_charge(NULL
, mask
, ptr
, true);
1961 /* drop extra refcnt from tryget */
1967 return __mem_cgroup_try_charge(mm
, mask
, ptr
, true);
1971 __mem_cgroup_commit_charge_swapin(struct page
*page
, struct mem_cgroup
*ptr
,
1972 enum charge_type ctype
)
1974 struct page_cgroup
*pc
;
1976 if (mem_cgroup_disabled())
1980 cgroup_exclude_rmdir(&ptr
->css
);
1981 pc
= lookup_page_cgroup(page
);
1982 mem_cgroup_lru_del_before_commit_swapcache(page
);
1983 __mem_cgroup_commit_charge(ptr
, pc
, ctype
);
1984 mem_cgroup_lru_add_after_commit_swapcache(page
);
1986 * Now swap is on-memory. This means this page may be
1987 * counted both as mem and swap....double count.
1988 * Fix it by uncharging from memsw. Basically, this SwapCache is stable
1989 * under lock_page(). But in do_swap_page()::memory.c, reuse_swap_page()
1990 * may call delete_from_swap_cache() before reach here.
1992 if (do_swap_account
&& PageSwapCache(page
)) {
1993 swp_entry_t ent
= {.val
= page_private(page
)};
1995 struct mem_cgroup
*memcg
;
1997 id
= swap_cgroup_record(ent
, 0);
1999 memcg
= mem_cgroup_lookup(id
);
2002 * This recorded memcg can be obsolete one. So, avoid
2003 * calling css_tryget
2005 if (!mem_cgroup_is_root(memcg
))
2006 res_counter_uncharge(&memcg
->memsw
, PAGE_SIZE
);
2007 mem_cgroup_swap_statistics(memcg
, false);
2008 mem_cgroup_put(memcg
);
2013 * At swapin, we may charge account against cgroup which has no tasks.
2014 * So, rmdir()->pre_destroy() can be called while we do this charge.
2015 * In that case, we need to call pre_destroy() again. check it here.
2017 cgroup_release_and_wakeup_rmdir(&ptr
->css
);
2020 void mem_cgroup_commit_charge_swapin(struct page
*page
, struct mem_cgroup
*ptr
)
2022 __mem_cgroup_commit_charge_swapin(page
, ptr
,
2023 MEM_CGROUP_CHARGE_TYPE_MAPPED
);
2026 void mem_cgroup_cancel_charge_swapin(struct mem_cgroup
*mem
)
2028 if (mem_cgroup_disabled())
2032 mem_cgroup_cancel_charge(mem
);
2036 __do_uncharge(struct mem_cgroup
*mem
, const enum charge_type ctype
)
2038 struct memcg_batch_info
*batch
= NULL
;
2039 bool uncharge_memsw
= true;
2040 /* If swapout, usage of swap doesn't decrease */
2041 if (!do_swap_account
|| ctype
== MEM_CGROUP_CHARGE_TYPE_SWAPOUT
)
2042 uncharge_memsw
= false;
2044 * do_batch > 0 when unmapping pages or inode invalidate/truncate.
2045 * In those cases, all pages freed continously can be expected to be in
2046 * the same cgroup and we have chance to coalesce uncharges.
2047 * But we do uncharge one by one if this is killed by OOM(TIF_MEMDIE)
2048 * because we want to do uncharge as soon as possible.
2050 if (!current
->memcg_batch
.do_batch
|| test_thread_flag(TIF_MEMDIE
))
2051 goto direct_uncharge
;
2053 batch
= ¤t
->memcg_batch
;
2055 * In usual, we do css_get() when we remember memcg pointer.
2056 * But in this case, we keep res->usage until end of a series of
2057 * uncharges. Then, it's ok to ignore memcg's refcnt.
2062 * In typical case, batch->memcg == mem. This means we can
2063 * merge a series of uncharges to an uncharge of res_counter.
2064 * If not, we uncharge res_counter ony by one.
2066 if (batch
->memcg
!= mem
)
2067 goto direct_uncharge
;
2068 /* remember freed charge and uncharge it later */
2069 batch
->bytes
+= PAGE_SIZE
;
2071 batch
->memsw_bytes
+= PAGE_SIZE
;
2074 res_counter_uncharge(&mem
->res
, PAGE_SIZE
);
2076 res_counter_uncharge(&mem
->memsw
, PAGE_SIZE
);
2081 * uncharge if !page_mapped(page)
2083 static struct mem_cgroup
*
2084 __mem_cgroup_uncharge_common(struct page
*page
, enum charge_type ctype
)
2086 struct page_cgroup
*pc
;
2087 struct mem_cgroup
*mem
= NULL
;
2088 struct mem_cgroup_per_zone
*mz
;
2090 if (mem_cgroup_disabled())
2093 if (PageSwapCache(page
))
2097 * Check if our page_cgroup is valid
2099 pc
= lookup_page_cgroup(page
);
2100 if (unlikely(!pc
|| !PageCgroupUsed(pc
)))
2103 lock_page_cgroup(pc
);
2105 mem
= pc
->mem_cgroup
;
2107 if (!PageCgroupUsed(pc
))
2111 case MEM_CGROUP_CHARGE_TYPE_MAPPED
:
2112 case MEM_CGROUP_CHARGE_TYPE_DROP
:
2113 if (page_mapped(page
))
2116 case MEM_CGROUP_CHARGE_TYPE_SWAPOUT
:
2117 if (!PageAnon(page
)) { /* Shared memory */
2118 if (page
->mapping
&& !page_is_file_cache(page
))
2120 } else if (page_mapped(page
)) /* Anon */
2127 if (!mem_cgroup_is_root(mem
))
2128 __do_uncharge(mem
, ctype
);
2129 if (ctype
== MEM_CGROUP_CHARGE_TYPE_SWAPOUT
)
2130 mem_cgroup_swap_statistics(mem
, true);
2131 mem_cgroup_charge_statistics(mem
, pc
, false);
2133 ClearPageCgroupUsed(pc
);
2135 * pc->mem_cgroup is not cleared here. It will be accessed when it's
2136 * freed from LRU. This is safe because uncharged page is expected not
2137 * to be reused (freed soon). Exception is SwapCache, it's handled by
2138 * special functions.
2141 mz
= page_cgroup_zoneinfo(pc
);
2142 unlock_page_cgroup(pc
);
2144 memcg_check_events(mem
, page
);
2145 /* at swapout, this memcg will be accessed to record to swap */
2146 if (ctype
!= MEM_CGROUP_CHARGE_TYPE_SWAPOUT
)
2152 unlock_page_cgroup(pc
);
2156 void mem_cgroup_uncharge_page(struct page
*page
)
2159 if (page_mapped(page
))
2161 if (page
->mapping
&& !PageAnon(page
))
2163 __mem_cgroup_uncharge_common(page
, MEM_CGROUP_CHARGE_TYPE_MAPPED
);
2166 void mem_cgroup_uncharge_cache_page(struct page
*page
)
2168 VM_BUG_ON(page_mapped(page
));
2169 VM_BUG_ON(page
->mapping
);
2170 __mem_cgroup_uncharge_common(page
, MEM_CGROUP_CHARGE_TYPE_CACHE
);
2174 * Batch_start/batch_end is called in unmap_page_range/invlidate/trucate.
2175 * In that cases, pages are freed continuously and we can expect pages
2176 * are in the same memcg. All these calls itself limits the number of
2177 * pages freed at once, then uncharge_start/end() is called properly.
2178 * This may be called prural(2) times in a context,
2181 void mem_cgroup_uncharge_start(void)
2183 current
->memcg_batch
.do_batch
++;
2184 /* We can do nest. */
2185 if (current
->memcg_batch
.do_batch
== 1) {
2186 current
->memcg_batch
.memcg
= NULL
;
2187 current
->memcg_batch
.bytes
= 0;
2188 current
->memcg_batch
.memsw_bytes
= 0;
2192 void mem_cgroup_uncharge_end(void)
2194 struct memcg_batch_info
*batch
= ¤t
->memcg_batch
;
2196 if (!batch
->do_batch
)
2200 if (batch
->do_batch
) /* If stacked, do nothing. */
2206 * This "batch->memcg" is valid without any css_get/put etc...
2207 * bacause we hide charges behind us.
2210 res_counter_uncharge(&batch
->memcg
->res
, batch
->bytes
);
2211 if (batch
->memsw_bytes
)
2212 res_counter_uncharge(&batch
->memcg
->memsw
, batch
->memsw_bytes
);
2213 /* forget this pointer (for sanity check) */
2214 batch
->memcg
= NULL
;
2219 * called after __delete_from_swap_cache() and drop "page" account.
2220 * memcg information is recorded to swap_cgroup of "ent"
2223 mem_cgroup_uncharge_swapcache(struct page
*page
, swp_entry_t ent
, bool swapout
)
2225 struct mem_cgroup
*memcg
;
2226 int ctype
= MEM_CGROUP_CHARGE_TYPE_SWAPOUT
;
2228 if (!swapout
) /* this was a swap cache but the swap is unused ! */
2229 ctype
= MEM_CGROUP_CHARGE_TYPE_DROP
;
2231 memcg
= __mem_cgroup_uncharge_common(page
, ctype
);
2233 /* record memcg information */
2234 if (do_swap_account
&& swapout
&& memcg
) {
2235 swap_cgroup_record(ent
, css_id(&memcg
->css
));
2236 mem_cgroup_get(memcg
);
2238 if (swapout
&& memcg
)
2239 css_put(&memcg
->css
);
2243 #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP
2245 * called from swap_entry_free(). remove record in swap_cgroup and
2246 * uncharge "memsw" account.
2248 void mem_cgroup_uncharge_swap(swp_entry_t ent
)
2250 struct mem_cgroup
*memcg
;
2253 if (!do_swap_account
)
2256 id
= swap_cgroup_record(ent
, 0);
2258 memcg
= mem_cgroup_lookup(id
);
2261 * We uncharge this because swap is freed.
2262 * This memcg can be obsolete one. We avoid calling css_tryget
2264 if (!mem_cgroup_is_root(memcg
))
2265 res_counter_uncharge(&memcg
->memsw
, PAGE_SIZE
);
2266 mem_cgroup_swap_statistics(memcg
, false);
2267 mem_cgroup_put(memcg
);
2273 * mem_cgroup_move_swap_account - move swap charge and swap_cgroup's record.
2274 * @entry: swap entry to be moved
2275 * @from: mem_cgroup which the entry is moved from
2276 * @to: mem_cgroup which the entry is moved to
2277 * @need_fixup: whether we should fixup res_counters and refcounts.
2279 * It succeeds only when the swap_cgroup's record for this entry is the same
2280 * as the mem_cgroup's id of @from.
2282 * Returns 0 on success, -EINVAL on failure.
2284 * The caller must have charged to @to, IOW, called res_counter_charge() about
2285 * both res and memsw, and called css_get().
2287 static int mem_cgroup_move_swap_account(swp_entry_t entry
,
2288 struct mem_cgroup
*from
, struct mem_cgroup
*to
, bool need_fixup
)
2290 unsigned short old_id
, new_id
;
2292 old_id
= css_id(&from
->css
);
2293 new_id
= css_id(&to
->css
);
2295 if (swap_cgroup_cmpxchg(entry
, old_id
, new_id
) == old_id
) {
2296 mem_cgroup_swap_statistics(from
, false);
2297 mem_cgroup_swap_statistics(to
, true);
2299 * This function is only called from task migration context now.
2300 * It postpones res_counter and refcount handling till the end
2301 * of task migration(mem_cgroup_clear_mc()) for performance
2302 * improvement. But we cannot postpone mem_cgroup_get(to)
2303 * because if the process that has been moved to @to does
2304 * swap-in, the refcount of @to might be decreased to 0.
2308 if (!mem_cgroup_is_root(from
))
2309 res_counter_uncharge(&from
->memsw
, PAGE_SIZE
);
2310 mem_cgroup_put(from
);
2312 * we charged both to->res and to->memsw, so we should
2315 if (!mem_cgroup_is_root(to
))
2316 res_counter_uncharge(&to
->res
, PAGE_SIZE
);
2324 static inline int mem_cgroup_move_swap_account(swp_entry_t entry
,
2325 struct mem_cgroup
*from
, struct mem_cgroup
*to
, bool need_fixup
)
2332 * Before starting migration, account PAGE_SIZE to mem_cgroup that the old
2335 int mem_cgroup_prepare_migration(struct page
*page
, struct mem_cgroup
**ptr
)
2337 struct page_cgroup
*pc
;
2338 struct mem_cgroup
*mem
= NULL
;
2341 if (mem_cgroup_disabled())
2344 pc
= lookup_page_cgroup(page
);
2345 lock_page_cgroup(pc
);
2346 if (PageCgroupUsed(pc
)) {
2347 mem
= pc
->mem_cgroup
;
2350 unlock_page_cgroup(pc
);
2353 ret
= __mem_cgroup_try_charge(NULL
, GFP_KERNEL
, &mem
, false);
2360 /* remove redundant charge if migration failed*/
2361 void mem_cgroup_end_migration(struct mem_cgroup
*mem
,
2362 struct page
*oldpage
, struct page
*newpage
)
2364 struct page
*target
, *unused
;
2365 struct page_cgroup
*pc
;
2366 enum charge_type ctype
;
2370 cgroup_exclude_rmdir(&mem
->css
);
2371 /* at migration success, oldpage->mapping is NULL. */
2372 if (oldpage
->mapping
) {
2380 if (PageAnon(target
))
2381 ctype
= MEM_CGROUP_CHARGE_TYPE_MAPPED
;
2382 else if (page_is_file_cache(target
))
2383 ctype
= MEM_CGROUP_CHARGE_TYPE_CACHE
;
2385 ctype
= MEM_CGROUP_CHARGE_TYPE_SHMEM
;
2387 /* unused page is not on radix-tree now. */
2389 __mem_cgroup_uncharge_common(unused
, ctype
);
2391 pc
= lookup_page_cgroup(target
);
2393 * __mem_cgroup_commit_charge() check PCG_USED bit of page_cgroup.
2394 * So, double-counting is effectively avoided.
2396 __mem_cgroup_commit_charge(mem
, pc
, ctype
);
2399 * Both of oldpage and newpage are still under lock_page().
2400 * Then, we don't have to care about race in radix-tree.
2401 * But we have to be careful that this page is unmapped or not.
2403 * There is a case for !page_mapped(). At the start of
2404 * migration, oldpage was mapped. But now, it's zapped.
2405 * But we know *target* page is not freed/reused under us.
2406 * mem_cgroup_uncharge_page() does all necessary checks.
2408 if (ctype
== MEM_CGROUP_CHARGE_TYPE_MAPPED
)
2409 mem_cgroup_uncharge_page(target
);
2411 * At migration, we may charge account against cgroup which has no tasks
2412 * So, rmdir()->pre_destroy() can be called while we do this charge.
2413 * In that case, we need to call pre_destroy() again. check it here.
2415 cgroup_release_and_wakeup_rmdir(&mem
->css
);
2419 * A call to try to shrink memory usage on charge failure at shmem's swapin.
2420 * Calling hierarchical_reclaim is not enough because we should update
2421 * last_oom_jiffies to prevent pagefault_out_of_memory from invoking global OOM.
2422 * Moreover considering hierarchy, we should reclaim from the mem_over_limit,
2423 * not from the memcg which this page would be charged to.
2424 * try_charge_swapin does all of these works properly.
2426 int mem_cgroup_shmem_charge_fallback(struct page
*page
,
2427 struct mm_struct
*mm
,
2430 struct mem_cgroup
*mem
= NULL
;
2433 if (mem_cgroup_disabled())
2436 ret
= mem_cgroup_try_charge_swapin(mm
, page
, gfp_mask
, &mem
);
2438 mem_cgroup_cancel_charge_swapin(mem
); /* it does !mem check */
2443 static DEFINE_MUTEX(set_limit_mutex
);
2445 static int mem_cgroup_resize_limit(struct mem_cgroup
*memcg
,
2446 unsigned long long val
)
2451 int children
= mem_cgroup_count_children(memcg
);
2452 u64 curusage
, oldusage
;
2455 * For keeping hierarchical_reclaim simple, how long we should retry
2456 * is depends on callers. We set our retry-count to be function
2457 * of # of children which we should visit in this loop.
2459 retry_count
= MEM_CGROUP_RECLAIM_RETRIES
* children
;
2461 oldusage
= res_counter_read_u64(&memcg
->res
, RES_USAGE
);
2463 while (retry_count
) {
2464 if (signal_pending(current
)) {
2469 * Rather than hide all in some function, I do this in
2470 * open coded manner. You see what this really does.
2471 * We have to guarantee mem->res.limit < mem->memsw.limit.
2473 mutex_lock(&set_limit_mutex
);
2474 memswlimit
= res_counter_read_u64(&memcg
->memsw
, RES_LIMIT
);
2475 if (memswlimit
< val
) {
2477 mutex_unlock(&set_limit_mutex
);
2480 ret
= res_counter_set_limit(&memcg
->res
, val
);
2482 if (memswlimit
== val
)
2483 memcg
->memsw_is_minimum
= true;
2485 memcg
->memsw_is_minimum
= false;
2487 mutex_unlock(&set_limit_mutex
);
2492 mem_cgroup_hierarchical_reclaim(memcg
, NULL
, GFP_KERNEL
,
2493 MEM_CGROUP_RECLAIM_SHRINK
);
2494 curusage
= res_counter_read_u64(&memcg
->res
, RES_USAGE
);
2495 /* Usage is reduced ? */
2496 if (curusage
>= oldusage
)
2499 oldusage
= curusage
;
2505 static int mem_cgroup_resize_memsw_limit(struct mem_cgroup
*memcg
,
2506 unsigned long long val
)
2509 u64 memlimit
, oldusage
, curusage
;
2510 int children
= mem_cgroup_count_children(memcg
);
2513 /* see mem_cgroup_resize_res_limit */
2514 retry_count
= children
* MEM_CGROUP_RECLAIM_RETRIES
;
2515 oldusage
= res_counter_read_u64(&memcg
->memsw
, RES_USAGE
);
2516 while (retry_count
) {
2517 if (signal_pending(current
)) {
2522 * Rather than hide all in some function, I do this in
2523 * open coded manner. You see what this really does.
2524 * We have to guarantee mem->res.limit < mem->memsw.limit.
2526 mutex_lock(&set_limit_mutex
);
2527 memlimit
= res_counter_read_u64(&memcg
->res
, RES_LIMIT
);
2528 if (memlimit
> val
) {
2530 mutex_unlock(&set_limit_mutex
);
2533 ret
= res_counter_set_limit(&memcg
->memsw
, val
);
2535 if (memlimit
== val
)
2536 memcg
->memsw_is_minimum
= true;
2538 memcg
->memsw_is_minimum
= false;
2540 mutex_unlock(&set_limit_mutex
);
2545 mem_cgroup_hierarchical_reclaim(memcg
, NULL
, GFP_KERNEL
,
2546 MEM_CGROUP_RECLAIM_NOSWAP
|
2547 MEM_CGROUP_RECLAIM_SHRINK
);
2548 curusage
= res_counter_read_u64(&memcg
->memsw
, RES_USAGE
);
2549 /* Usage is reduced ? */
2550 if (curusage
>= oldusage
)
2553 oldusage
= curusage
;
2558 unsigned long mem_cgroup_soft_limit_reclaim(struct zone
*zone
, int order
,
2559 gfp_t gfp_mask
, int nid
,
2562 unsigned long nr_reclaimed
= 0;
2563 struct mem_cgroup_per_zone
*mz
, *next_mz
= NULL
;
2564 unsigned long reclaimed
;
2566 struct mem_cgroup_tree_per_zone
*mctz
;
2567 unsigned long long excess
;
2572 mctz
= soft_limit_tree_node_zone(nid
, zid
);
2574 * This loop can run a while, specially if mem_cgroup's continuously
2575 * keep exceeding their soft limit and putting the system under
2582 mz
= mem_cgroup_largest_soft_limit_node(mctz
);
2586 reclaimed
= mem_cgroup_hierarchical_reclaim(mz
->mem
, zone
,
2588 MEM_CGROUP_RECLAIM_SOFT
);
2589 nr_reclaimed
+= reclaimed
;
2590 spin_lock(&mctz
->lock
);
2593 * If we failed to reclaim anything from this memory cgroup
2594 * it is time to move on to the next cgroup
2600 * Loop until we find yet another one.
2602 * By the time we get the soft_limit lock
2603 * again, someone might have aded the
2604 * group back on the RB tree. Iterate to
2605 * make sure we get a different mem.
2606 * mem_cgroup_largest_soft_limit_node returns
2607 * NULL if no other cgroup is present on
2611 __mem_cgroup_largest_soft_limit_node(mctz
);
2612 if (next_mz
== mz
) {
2613 css_put(&next_mz
->mem
->css
);
2615 } else /* next_mz == NULL or other memcg */
2619 __mem_cgroup_remove_exceeded(mz
->mem
, mz
, mctz
);
2620 excess
= res_counter_soft_limit_excess(&mz
->mem
->res
);
2622 * One school of thought says that we should not add
2623 * back the node to the tree if reclaim returns 0.
2624 * But our reclaim could return 0, simply because due
2625 * to priority we are exposing a smaller subset of
2626 * memory to reclaim from. Consider this as a longer
2629 /* If excess == 0, no tree ops */
2630 __mem_cgroup_insert_exceeded(mz
->mem
, mz
, mctz
, excess
);
2631 spin_unlock(&mctz
->lock
);
2632 css_put(&mz
->mem
->css
);
2635 * Could not reclaim anything and there are no more
2636 * mem cgroups to try or we seem to be looping without
2637 * reclaiming anything.
2639 if (!nr_reclaimed
&&
2641 loop
> MEM_CGROUP_MAX_SOFT_LIMIT_RECLAIM_LOOPS
))
2643 } while (!nr_reclaimed
);
2645 css_put(&next_mz
->mem
->css
);
2646 return nr_reclaimed
;
2650 * This routine traverse page_cgroup in given list and drop them all.
2651 * *And* this routine doesn't reclaim page itself, just removes page_cgroup.
2653 static int mem_cgroup_force_empty_list(struct mem_cgroup
*mem
,
2654 int node
, int zid
, enum lru_list lru
)
2657 struct mem_cgroup_per_zone
*mz
;
2658 struct page_cgroup
*pc
, *busy
;
2659 unsigned long flags
, loop
;
2660 struct list_head
*list
;
2663 zone
= &NODE_DATA(node
)->node_zones
[zid
];
2664 mz
= mem_cgroup_zoneinfo(mem
, node
, zid
);
2665 list
= &mz
->lists
[lru
];
2667 loop
= MEM_CGROUP_ZSTAT(mz
, lru
);
2668 /* give some margin against EBUSY etc...*/
2673 spin_lock_irqsave(&zone
->lru_lock
, flags
);
2674 if (list_empty(list
)) {
2675 spin_unlock_irqrestore(&zone
->lru_lock
, flags
);
2678 pc
= list_entry(list
->prev
, struct page_cgroup
, lru
);
2680 list_move(&pc
->lru
, list
);
2682 spin_unlock_irqrestore(&zone
->lru_lock
, flags
);
2685 spin_unlock_irqrestore(&zone
->lru_lock
, flags
);
2687 ret
= mem_cgroup_move_parent(pc
, mem
, GFP_KERNEL
);
2691 if (ret
== -EBUSY
|| ret
== -EINVAL
) {
2692 /* found lock contention or "pc" is obsolete. */
2699 if (!ret
&& !list_empty(list
))
2705 * make mem_cgroup's charge to be 0 if there is no task.
2706 * This enables deleting this mem_cgroup.
2708 static int mem_cgroup_force_empty(struct mem_cgroup
*mem
, bool free_all
)
2711 int node
, zid
, shrink
;
2712 int nr_retries
= MEM_CGROUP_RECLAIM_RETRIES
;
2713 struct cgroup
*cgrp
= mem
->css
.cgroup
;
2718 /* should free all ? */
2724 if (cgroup_task_count(cgrp
) || !list_empty(&cgrp
->children
))
2727 if (signal_pending(current
))
2729 /* This is for making all *used* pages to be on LRU. */
2730 lru_add_drain_all();
2731 drain_all_stock_sync();
2733 for_each_node_state(node
, N_HIGH_MEMORY
) {
2734 for (zid
= 0; !ret
&& zid
< MAX_NR_ZONES
; zid
++) {
2737 ret
= mem_cgroup_force_empty_list(mem
,
2746 /* it seems parent cgroup doesn't have enough mem */
2750 /* "ret" should also be checked to ensure all lists are empty. */
2751 } while (mem
->res
.usage
> 0 || ret
);
2757 /* returns EBUSY if there is a task or if we come here twice. */
2758 if (cgroup_task_count(cgrp
) || !list_empty(&cgrp
->children
) || shrink
) {
2762 /* we call try-to-free pages for make this cgroup empty */
2763 lru_add_drain_all();
2764 /* try to free all pages in this cgroup */
2766 while (nr_retries
&& mem
->res
.usage
> 0) {
2769 if (signal_pending(current
)) {
2773 progress
= try_to_free_mem_cgroup_pages(mem
, GFP_KERNEL
,
2774 false, get_swappiness(mem
));
2777 /* maybe some writeback is necessary */
2778 congestion_wait(BLK_RW_ASYNC
, HZ
/10);
2783 /* try move_account...there may be some *locked* pages. */
2787 int mem_cgroup_force_empty_write(struct cgroup
*cont
, unsigned int event
)
2789 return mem_cgroup_force_empty(mem_cgroup_from_cont(cont
), true);
2793 static u64
mem_cgroup_hierarchy_read(struct cgroup
*cont
, struct cftype
*cft
)
2795 return mem_cgroup_from_cont(cont
)->use_hierarchy
;
2798 static int mem_cgroup_hierarchy_write(struct cgroup
*cont
, struct cftype
*cft
,
2802 struct mem_cgroup
*mem
= mem_cgroup_from_cont(cont
);
2803 struct cgroup
*parent
= cont
->parent
;
2804 struct mem_cgroup
*parent_mem
= NULL
;
2807 parent_mem
= mem_cgroup_from_cont(parent
);
2811 * If parent's use_hierarchy is set, we can't make any modifications
2812 * in the child subtrees. If it is unset, then the change can
2813 * occur, provided the current cgroup has no children.
2815 * For the root cgroup, parent_mem is NULL, we allow value to be
2816 * set if there are no children.
2818 if ((!parent_mem
|| !parent_mem
->use_hierarchy
) &&
2819 (val
== 1 || val
== 0)) {
2820 if (list_empty(&cont
->children
))
2821 mem
->use_hierarchy
= val
;
2831 struct mem_cgroup_idx_data
{
2833 enum mem_cgroup_stat_index idx
;
2837 mem_cgroup_get_idx_stat(struct mem_cgroup
*mem
, void *data
)
2839 struct mem_cgroup_idx_data
*d
= data
;
2840 d
->val
+= mem_cgroup_read_stat(mem
, d
->idx
);
2845 mem_cgroup_get_recursive_idx_stat(struct mem_cgroup
*mem
,
2846 enum mem_cgroup_stat_index idx
, s64
*val
)
2848 struct mem_cgroup_idx_data d
;
2851 mem_cgroup_walk_tree(mem
, &d
, mem_cgroup_get_idx_stat
);
2855 static inline u64
mem_cgroup_usage(struct mem_cgroup
*mem
, bool swap
)
2859 if (!mem_cgroup_is_root(mem
)) {
2861 return res_counter_read_u64(&mem
->res
, RES_USAGE
);
2863 return res_counter_read_u64(&mem
->memsw
, RES_USAGE
);
2866 mem_cgroup_get_recursive_idx_stat(mem
, MEM_CGROUP_STAT_CACHE
, &idx_val
);
2868 mem_cgroup_get_recursive_idx_stat(mem
, MEM_CGROUP_STAT_RSS
, &idx_val
);
2872 mem_cgroup_get_recursive_idx_stat(mem
,
2873 MEM_CGROUP_STAT_SWAPOUT
, &idx_val
);
2877 return val
<< PAGE_SHIFT
;
2880 static u64
mem_cgroup_read(struct cgroup
*cont
, struct cftype
*cft
)
2882 struct mem_cgroup
*mem
= mem_cgroup_from_cont(cont
);
2886 type
= MEMFILE_TYPE(cft
->private);
2887 name
= MEMFILE_ATTR(cft
->private);
2890 if (name
== RES_USAGE
)
2891 val
= mem_cgroup_usage(mem
, false);
2893 val
= res_counter_read_u64(&mem
->res
, name
);
2896 if (name
== RES_USAGE
)
2897 val
= mem_cgroup_usage(mem
, true);
2899 val
= res_counter_read_u64(&mem
->memsw
, name
);
2908 * The user of this function is...
2911 static int mem_cgroup_write(struct cgroup
*cont
, struct cftype
*cft
,
2914 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cont
);
2916 unsigned long long val
;
2919 type
= MEMFILE_TYPE(cft
->private);
2920 name
= MEMFILE_ATTR(cft
->private);
2923 if (mem_cgroup_is_root(memcg
)) { /* Can't set limit on root */
2927 /* This function does all necessary parse...reuse it */
2928 ret
= res_counter_memparse_write_strategy(buffer
, &val
);
2932 ret
= mem_cgroup_resize_limit(memcg
, val
);
2934 ret
= mem_cgroup_resize_memsw_limit(memcg
, val
);
2936 case RES_SOFT_LIMIT
:
2937 ret
= res_counter_memparse_write_strategy(buffer
, &val
);
2941 * For memsw, soft limits are hard to implement in terms
2942 * of semantics, for now, we support soft limits for
2943 * control without swap
2946 ret
= res_counter_set_soft_limit(&memcg
->res
, val
);
2951 ret
= -EINVAL
; /* should be BUG() ? */
2957 static void memcg_get_hierarchical_limit(struct mem_cgroup
*memcg
,
2958 unsigned long long *mem_limit
, unsigned long long *memsw_limit
)
2960 struct cgroup
*cgroup
;
2961 unsigned long long min_limit
, min_memsw_limit
, tmp
;
2963 min_limit
= res_counter_read_u64(&memcg
->res
, RES_LIMIT
);
2964 min_memsw_limit
= res_counter_read_u64(&memcg
->memsw
, RES_LIMIT
);
2965 cgroup
= memcg
->css
.cgroup
;
2966 if (!memcg
->use_hierarchy
)
2969 while (cgroup
->parent
) {
2970 cgroup
= cgroup
->parent
;
2971 memcg
= mem_cgroup_from_cont(cgroup
);
2972 if (!memcg
->use_hierarchy
)
2974 tmp
= res_counter_read_u64(&memcg
->res
, RES_LIMIT
);
2975 min_limit
= min(min_limit
, tmp
);
2976 tmp
= res_counter_read_u64(&memcg
->memsw
, RES_LIMIT
);
2977 min_memsw_limit
= min(min_memsw_limit
, tmp
);
2980 *mem_limit
= min_limit
;
2981 *memsw_limit
= min_memsw_limit
;
2985 static int mem_cgroup_reset(struct cgroup
*cont
, unsigned int event
)
2987 struct mem_cgroup
*mem
;
2990 mem
= mem_cgroup_from_cont(cont
);
2991 type
= MEMFILE_TYPE(event
);
2992 name
= MEMFILE_ATTR(event
);
2996 res_counter_reset_max(&mem
->res
);
2998 res_counter_reset_max(&mem
->memsw
);
3002 res_counter_reset_failcnt(&mem
->res
);
3004 res_counter_reset_failcnt(&mem
->memsw
);
3011 static u64
mem_cgroup_move_charge_read(struct cgroup
*cgrp
,
3014 return mem_cgroup_from_cont(cgrp
)->move_charge_at_immigrate
;
3018 static int mem_cgroup_move_charge_write(struct cgroup
*cgrp
,
3019 struct cftype
*cft
, u64 val
)
3021 struct mem_cgroup
*mem
= mem_cgroup_from_cont(cgrp
);
3023 if (val
>= (1 << NR_MOVE_TYPE
))
3026 * We check this value several times in both in can_attach() and
3027 * attach(), so we need cgroup lock to prevent this value from being
3031 mem
->move_charge_at_immigrate
= val
;
3037 static int mem_cgroup_move_charge_write(struct cgroup
*cgrp
,
3038 struct cftype
*cft
, u64 val
)
3045 /* For read statistics */
3061 struct mcs_total_stat
{
3062 s64 stat
[NR_MCS_STAT
];
3068 } memcg_stat_strings
[NR_MCS_STAT
] = {
3069 {"cache", "total_cache"},
3070 {"rss", "total_rss"},
3071 {"mapped_file", "total_mapped_file"},
3072 {"pgpgin", "total_pgpgin"},
3073 {"pgpgout", "total_pgpgout"},
3074 {"swap", "total_swap"},
3075 {"inactive_anon", "total_inactive_anon"},
3076 {"active_anon", "total_active_anon"},
3077 {"inactive_file", "total_inactive_file"},
3078 {"active_file", "total_active_file"},
3079 {"unevictable", "total_unevictable"}
3083 static int mem_cgroup_get_local_stat(struct mem_cgroup
*mem
, void *data
)
3085 struct mcs_total_stat
*s
= data
;
3089 val
= mem_cgroup_read_stat(mem
, MEM_CGROUP_STAT_CACHE
);
3090 s
->stat
[MCS_CACHE
] += val
* PAGE_SIZE
;
3091 val
= mem_cgroup_read_stat(mem
, MEM_CGROUP_STAT_RSS
);
3092 s
->stat
[MCS_RSS
] += val
* PAGE_SIZE
;
3093 val
= mem_cgroup_read_stat(mem
, MEM_CGROUP_STAT_FILE_MAPPED
);
3094 s
->stat
[MCS_FILE_MAPPED
] += val
* PAGE_SIZE
;
3095 val
= mem_cgroup_read_stat(mem
, MEM_CGROUP_STAT_PGPGIN_COUNT
);
3096 s
->stat
[MCS_PGPGIN
] += val
;
3097 val
= mem_cgroup_read_stat(mem
, MEM_CGROUP_STAT_PGPGOUT_COUNT
);
3098 s
->stat
[MCS_PGPGOUT
] += val
;
3099 if (do_swap_account
) {
3100 val
= mem_cgroup_read_stat(mem
, MEM_CGROUP_STAT_SWAPOUT
);
3101 s
->stat
[MCS_SWAP
] += val
* PAGE_SIZE
;
3105 val
= mem_cgroup_get_local_zonestat(mem
, LRU_INACTIVE_ANON
);
3106 s
->stat
[MCS_INACTIVE_ANON
] += val
* PAGE_SIZE
;
3107 val
= mem_cgroup_get_local_zonestat(mem
, LRU_ACTIVE_ANON
);
3108 s
->stat
[MCS_ACTIVE_ANON
] += val
* PAGE_SIZE
;
3109 val
= mem_cgroup_get_local_zonestat(mem
, LRU_INACTIVE_FILE
);
3110 s
->stat
[MCS_INACTIVE_FILE
] += val
* PAGE_SIZE
;
3111 val
= mem_cgroup_get_local_zonestat(mem
, LRU_ACTIVE_FILE
);
3112 s
->stat
[MCS_ACTIVE_FILE
] += val
* PAGE_SIZE
;
3113 val
= mem_cgroup_get_local_zonestat(mem
, LRU_UNEVICTABLE
);
3114 s
->stat
[MCS_UNEVICTABLE
] += val
* PAGE_SIZE
;
3119 mem_cgroup_get_total_stat(struct mem_cgroup
*mem
, struct mcs_total_stat
*s
)
3121 mem_cgroup_walk_tree(mem
, s
, mem_cgroup_get_local_stat
);
3124 static int mem_control_stat_show(struct cgroup
*cont
, struct cftype
*cft
,
3125 struct cgroup_map_cb
*cb
)
3127 struct mem_cgroup
*mem_cont
= mem_cgroup_from_cont(cont
);
3128 struct mcs_total_stat mystat
;
3131 memset(&mystat
, 0, sizeof(mystat
));
3132 mem_cgroup_get_local_stat(mem_cont
, &mystat
);
3134 for (i
= 0; i
< NR_MCS_STAT
; i
++) {
3135 if (i
== MCS_SWAP
&& !do_swap_account
)
3137 cb
->fill(cb
, memcg_stat_strings
[i
].local_name
, mystat
.stat
[i
]);
3140 /* Hierarchical information */
3142 unsigned long long limit
, memsw_limit
;
3143 memcg_get_hierarchical_limit(mem_cont
, &limit
, &memsw_limit
);
3144 cb
->fill(cb
, "hierarchical_memory_limit", limit
);
3145 if (do_swap_account
)
3146 cb
->fill(cb
, "hierarchical_memsw_limit", memsw_limit
);
3149 memset(&mystat
, 0, sizeof(mystat
));
3150 mem_cgroup_get_total_stat(mem_cont
, &mystat
);
3151 for (i
= 0; i
< NR_MCS_STAT
; i
++) {
3152 if (i
== MCS_SWAP
&& !do_swap_account
)
3154 cb
->fill(cb
, memcg_stat_strings
[i
].total_name
, mystat
.stat
[i
]);
3157 #ifdef CONFIG_DEBUG_VM
3158 cb
->fill(cb
, "inactive_ratio", calc_inactive_ratio(mem_cont
, NULL
));
3162 struct mem_cgroup_per_zone
*mz
;
3163 unsigned long recent_rotated
[2] = {0, 0};
3164 unsigned long recent_scanned
[2] = {0, 0};
3166 for_each_online_node(nid
)
3167 for (zid
= 0; zid
< MAX_NR_ZONES
; zid
++) {
3168 mz
= mem_cgroup_zoneinfo(mem_cont
, nid
, zid
);
3170 recent_rotated
[0] +=
3171 mz
->reclaim_stat
.recent_rotated
[0];
3172 recent_rotated
[1] +=
3173 mz
->reclaim_stat
.recent_rotated
[1];
3174 recent_scanned
[0] +=
3175 mz
->reclaim_stat
.recent_scanned
[0];
3176 recent_scanned
[1] +=
3177 mz
->reclaim_stat
.recent_scanned
[1];
3179 cb
->fill(cb
, "recent_rotated_anon", recent_rotated
[0]);
3180 cb
->fill(cb
, "recent_rotated_file", recent_rotated
[1]);
3181 cb
->fill(cb
, "recent_scanned_anon", recent_scanned
[0]);
3182 cb
->fill(cb
, "recent_scanned_file", recent_scanned
[1]);
3189 static u64
mem_cgroup_swappiness_read(struct cgroup
*cgrp
, struct cftype
*cft
)
3191 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cgrp
);
3193 return get_swappiness(memcg
);
3196 static int mem_cgroup_swappiness_write(struct cgroup
*cgrp
, struct cftype
*cft
,
3199 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cgrp
);
3200 struct mem_cgroup
*parent
;
3205 if (cgrp
->parent
== NULL
)
3208 parent
= mem_cgroup_from_cont(cgrp
->parent
);
3212 /* If under hierarchy, only empty-root can set this value */
3213 if ((parent
->use_hierarchy
) ||
3214 (memcg
->use_hierarchy
&& !list_empty(&cgrp
->children
))) {
3219 spin_lock(&memcg
->reclaim_param_lock
);
3220 memcg
->swappiness
= val
;
3221 spin_unlock(&memcg
->reclaim_param_lock
);
3228 static void __mem_cgroup_threshold(struct mem_cgroup
*memcg
, bool swap
)
3230 struct mem_cgroup_threshold_ary
*t
;
3236 t
= rcu_dereference(memcg
->thresholds
);
3238 t
= rcu_dereference(memcg
->memsw_thresholds
);
3243 usage
= mem_cgroup_usage(memcg
, swap
);
3246 * current_threshold points to threshold just below usage.
3247 * If it's not true, a threshold was crossed after last
3248 * call of __mem_cgroup_threshold().
3250 i
= atomic_read(&t
->current_threshold
);
3253 * Iterate backward over array of thresholds starting from
3254 * current_threshold and check if a threshold is crossed.
3255 * If none of thresholds below usage is crossed, we read
3256 * only one element of the array here.
3258 for (; i
>= 0 && unlikely(t
->entries
[i
].threshold
> usage
); i
--)
3259 eventfd_signal(t
->entries
[i
].eventfd
, 1);
3261 /* i = current_threshold + 1 */
3265 * Iterate forward over array of thresholds starting from
3266 * current_threshold+1 and check if a threshold is crossed.
3267 * If none of thresholds above usage is crossed, we read
3268 * only one element of the array here.
3270 for (; i
< t
->size
&& unlikely(t
->entries
[i
].threshold
<= usage
); i
++)
3271 eventfd_signal(t
->entries
[i
].eventfd
, 1);
3273 /* Update current_threshold */
3274 atomic_set(&t
->current_threshold
, i
- 1);
3279 static void mem_cgroup_threshold(struct mem_cgroup
*memcg
)
3281 __mem_cgroup_threshold(memcg
, false);
3282 if (do_swap_account
)
3283 __mem_cgroup_threshold(memcg
, true);
3286 static int compare_thresholds(const void *a
, const void *b
)
3288 const struct mem_cgroup_threshold
*_a
= a
;
3289 const struct mem_cgroup_threshold
*_b
= b
;
3291 return _a
->threshold
- _b
->threshold
;
3294 static int mem_cgroup_register_event(struct cgroup
*cgrp
, struct cftype
*cft
,
3295 struct eventfd_ctx
*eventfd
, const char *args
)
3297 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cgrp
);
3298 struct mem_cgroup_threshold_ary
*thresholds
, *thresholds_new
;
3299 int type
= MEMFILE_TYPE(cft
->private);
3300 u64 threshold
, usage
;
3304 ret
= res_counter_memparse_write_strategy(args
, &threshold
);
3308 mutex_lock(&memcg
->thresholds_lock
);
3310 thresholds
= memcg
->thresholds
;
3311 else if (type
== _MEMSWAP
)
3312 thresholds
= memcg
->memsw_thresholds
;
3316 usage
= mem_cgroup_usage(memcg
, type
== _MEMSWAP
);
3318 /* Check if a threshold crossed before adding a new one */
3320 __mem_cgroup_threshold(memcg
, type
== _MEMSWAP
);
3323 size
= thresholds
->size
+ 1;
3327 /* Allocate memory for new array of thresholds */
3328 thresholds_new
= kmalloc(sizeof(*thresholds_new
) +
3329 size
* sizeof(struct mem_cgroup_threshold
),
3331 if (!thresholds_new
) {
3335 thresholds_new
->size
= size
;
3337 /* Copy thresholds (if any) to new array */
3339 memcpy(thresholds_new
->entries
, thresholds
->entries
,
3341 sizeof(struct mem_cgroup_threshold
));
3342 /* Add new threshold */
3343 thresholds_new
->entries
[size
- 1].eventfd
= eventfd
;
3344 thresholds_new
->entries
[size
- 1].threshold
= threshold
;
3346 /* Sort thresholds. Registering of new threshold isn't time-critical */
3347 sort(thresholds_new
->entries
, size
,
3348 sizeof(struct mem_cgroup_threshold
),
3349 compare_thresholds
, NULL
);
3351 /* Find current threshold */
3352 atomic_set(&thresholds_new
->current_threshold
, -1);
3353 for (i
= 0; i
< size
; i
++) {
3354 if (thresholds_new
->entries
[i
].threshold
< usage
) {
3356 * thresholds_new->current_threshold will not be used
3357 * until rcu_assign_pointer(), so it's safe to increment
3360 atomic_inc(&thresholds_new
->current_threshold
);
3365 rcu_assign_pointer(memcg
->thresholds
, thresholds_new
);
3367 rcu_assign_pointer(memcg
->memsw_thresholds
, thresholds_new
);
3369 /* To be sure that nobody uses thresholds before freeing it */
3374 mutex_unlock(&memcg
->thresholds_lock
);
3379 static int mem_cgroup_unregister_event(struct cgroup
*cgrp
, struct cftype
*cft
,
3380 struct eventfd_ctx
*eventfd
)
3382 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cgrp
);
3383 struct mem_cgroup_threshold_ary
*thresholds
, *thresholds_new
;
3384 int type
= MEMFILE_TYPE(cft
->private);
3389 mutex_lock(&memcg
->thresholds_lock
);
3391 thresholds
= memcg
->thresholds
;
3392 else if (type
== _MEMSWAP
)
3393 thresholds
= memcg
->memsw_thresholds
;
3398 * Something went wrong if we trying to unregister a threshold
3399 * if we don't have thresholds
3401 BUG_ON(!thresholds
);
3403 usage
= mem_cgroup_usage(memcg
, type
== _MEMSWAP
);
3405 /* Check if a threshold crossed before removing */
3406 __mem_cgroup_threshold(memcg
, type
== _MEMSWAP
);
3408 /* Calculate new number of threshold */
3409 for (i
= 0; i
< thresholds
->size
; i
++) {
3410 if (thresholds
->entries
[i
].eventfd
!= eventfd
)
3414 /* Set thresholds array to NULL if we don't have thresholds */
3416 thresholds_new
= NULL
;
3420 /* Allocate memory for new array of thresholds */
3421 thresholds_new
= kmalloc(sizeof(*thresholds_new
) +
3422 size
* sizeof(struct mem_cgroup_threshold
),
3424 if (!thresholds_new
) {
3428 thresholds_new
->size
= size
;
3430 /* Copy thresholds and find current threshold */
3431 atomic_set(&thresholds_new
->current_threshold
, -1);
3432 for (i
= 0, j
= 0; i
< thresholds
->size
; i
++) {
3433 if (thresholds
->entries
[i
].eventfd
== eventfd
)
3436 thresholds_new
->entries
[j
] = thresholds
->entries
[i
];
3437 if (thresholds_new
->entries
[j
].threshold
< usage
) {
3439 * thresholds_new->current_threshold will not be used
3440 * until rcu_assign_pointer(), so it's safe to increment
3443 atomic_inc(&thresholds_new
->current_threshold
);
3450 rcu_assign_pointer(memcg
->thresholds
, thresholds_new
);
3452 rcu_assign_pointer(memcg
->memsw_thresholds
, thresholds_new
);
3454 /* To be sure that nobody uses thresholds before freeing it */
3459 mutex_unlock(&memcg
->thresholds_lock
);
3464 static struct cftype mem_cgroup_files
[] = {
3466 .name
= "usage_in_bytes",
3467 .private = MEMFILE_PRIVATE(_MEM
, RES_USAGE
),
3468 .read_u64
= mem_cgroup_read
,
3469 .register_event
= mem_cgroup_register_event
,
3470 .unregister_event
= mem_cgroup_unregister_event
,
3473 .name
= "max_usage_in_bytes",
3474 .private = MEMFILE_PRIVATE(_MEM
, RES_MAX_USAGE
),
3475 .trigger
= mem_cgroup_reset
,
3476 .read_u64
= mem_cgroup_read
,
3479 .name
= "limit_in_bytes",
3480 .private = MEMFILE_PRIVATE(_MEM
, RES_LIMIT
),
3481 .write_string
= mem_cgroup_write
,
3482 .read_u64
= mem_cgroup_read
,
3485 .name
= "soft_limit_in_bytes",
3486 .private = MEMFILE_PRIVATE(_MEM
, RES_SOFT_LIMIT
),
3487 .write_string
= mem_cgroup_write
,
3488 .read_u64
= mem_cgroup_read
,
3492 .private = MEMFILE_PRIVATE(_MEM
, RES_FAILCNT
),
3493 .trigger
= mem_cgroup_reset
,
3494 .read_u64
= mem_cgroup_read
,
3498 .read_map
= mem_control_stat_show
,
3501 .name
= "force_empty",
3502 .trigger
= mem_cgroup_force_empty_write
,
3505 .name
= "use_hierarchy",
3506 .write_u64
= mem_cgroup_hierarchy_write
,
3507 .read_u64
= mem_cgroup_hierarchy_read
,
3510 .name
= "swappiness",
3511 .read_u64
= mem_cgroup_swappiness_read
,
3512 .write_u64
= mem_cgroup_swappiness_write
,
3515 .name
= "move_charge_at_immigrate",
3516 .read_u64
= mem_cgroup_move_charge_read
,
3517 .write_u64
= mem_cgroup_move_charge_write
,
3521 #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP
3522 static struct cftype memsw_cgroup_files
[] = {
3524 .name
= "memsw.usage_in_bytes",
3525 .private = MEMFILE_PRIVATE(_MEMSWAP
, RES_USAGE
),
3526 .read_u64
= mem_cgroup_read
,
3527 .register_event
= mem_cgroup_register_event
,
3528 .unregister_event
= mem_cgroup_unregister_event
,
3531 .name
= "memsw.max_usage_in_bytes",
3532 .private = MEMFILE_PRIVATE(_MEMSWAP
, RES_MAX_USAGE
),
3533 .trigger
= mem_cgroup_reset
,
3534 .read_u64
= mem_cgroup_read
,
3537 .name
= "memsw.limit_in_bytes",
3538 .private = MEMFILE_PRIVATE(_MEMSWAP
, RES_LIMIT
),
3539 .write_string
= mem_cgroup_write
,
3540 .read_u64
= mem_cgroup_read
,
3543 .name
= "memsw.failcnt",
3544 .private = MEMFILE_PRIVATE(_MEMSWAP
, RES_FAILCNT
),
3545 .trigger
= mem_cgroup_reset
,
3546 .read_u64
= mem_cgroup_read
,
3550 static int register_memsw_files(struct cgroup
*cont
, struct cgroup_subsys
*ss
)
3552 if (!do_swap_account
)
3554 return cgroup_add_files(cont
, ss
, memsw_cgroup_files
,
3555 ARRAY_SIZE(memsw_cgroup_files
));
3558 static int register_memsw_files(struct cgroup
*cont
, struct cgroup_subsys
*ss
)
3564 static int alloc_mem_cgroup_per_zone_info(struct mem_cgroup
*mem
, int node
)
3566 struct mem_cgroup_per_node
*pn
;
3567 struct mem_cgroup_per_zone
*mz
;
3569 int zone
, tmp
= node
;
3571 * This routine is called against possible nodes.
3572 * But it's BUG to call kmalloc() against offline node.
3574 * TODO: this routine can waste much memory for nodes which will
3575 * never be onlined. It's better to use memory hotplug callback
3578 if (!node_state(node
, N_NORMAL_MEMORY
))
3580 pn
= kmalloc_node(sizeof(*pn
), GFP_KERNEL
, tmp
);
3584 mem
->info
.nodeinfo
[node
] = pn
;
3585 memset(pn
, 0, sizeof(*pn
));
3587 for (zone
= 0; zone
< MAX_NR_ZONES
; zone
++) {
3588 mz
= &pn
->zoneinfo
[zone
];
3590 INIT_LIST_HEAD(&mz
->lists
[l
]);
3591 mz
->usage_in_excess
= 0;
3592 mz
->on_tree
= false;
3598 static void free_mem_cgroup_per_zone_info(struct mem_cgroup
*mem
, int node
)
3600 kfree(mem
->info
.nodeinfo
[node
]);
3603 static struct mem_cgroup
*mem_cgroup_alloc(void)
3605 struct mem_cgroup
*mem
;
3606 int size
= sizeof(struct mem_cgroup
);
3608 /* Can be very big if MAX_NUMNODES is very big */
3609 if (size
< PAGE_SIZE
)
3610 mem
= kmalloc(size
, GFP_KERNEL
);
3612 mem
= vmalloc(size
);
3615 memset(mem
, 0, size
);
3616 mem
->stat
= alloc_percpu(struct mem_cgroup_stat_cpu
);
3618 if (size
< PAGE_SIZE
)
3628 * At destroying mem_cgroup, references from swap_cgroup can remain.
3629 * (scanning all at force_empty is too costly...)
3631 * Instead of clearing all references at force_empty, we remember
3632 * the number of reference from swap_cgroup and free mem_cgroup when
3633 * it goes down to 0.
3635 * Removal of cgroup itself succeeds regardless of refs from swap.
3638 static void __mem_cgroup_free(struct mem_cgroup
*mem
)
3642 mem_cgroup_remove_from_trees(mem
);
3643 free_css_id(&mem_cgroup_subsys
, &mem
->css
);
3645 for_each_node_state(node
, N_POSSIBLE
)
3646 free_mem_cgroup_per_zone_info(mem
, node
);
3648 free_percpu(mem
->stat
);
3649 if (sizeof(struct mem_cgroup
) < PAGE_SIZE
)
3655 static void mem_cgroup_get(struct mem_cgroup
*mem
)
3657 atomic_inc(&mem
->refcnt
);
3660 static void __mem_cgroup_put(struct mem_cgroup
*mem
, int count
)
3662 if (atomic_sub_and_test(count
, &mem
->refcnt
)) {
3663 struct mem_cgroup
*parent
= parent_mem_cgroup(mem
);
3664 __mem_cgroup_free(mem
);
3666 mem_cgroup_put(parent
);
3670 static void mem_cgroup_put(struct mem_cgroup
*mem
)
3672 __mem_cgroup_put(mem
, 1);
3676 * Returns the parent mem_cgroup in memcgroup hierarchy with hierarchy enabled.
3678 static struct mem_cgroup
*parent_mem_cgroup(struct mem_cgroup
*mem
)
3680 if (!mem
->res
.parent
)
3682 return mem_cgroup_from_res_counter(mem
->res
.parent
, res
);
3685 #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP
3686 static void __init
enable_swap_cgroup(void)
3688 if (!mem_cgroup_disabled() && really_do_swap_account
)
3689 do_swap_account
= 1;
3692 static void __init
enable_swap_cgroup(void)
3697 static int mem_cgroup_soft_limit_tree_init(void)
3699 struct mem_cgroup_tree_per_node
*rtpn
;
3700 struct mem_cgroup_tree_per_zone
*rtpz
;
3701 int tmp
, node
, zone
;
3703 for_each_node_state(node
, N_POSSIBLE
) {
3705 if (!node_state(node
, N_NORMAL_MEMORY
))
3707 rtpn
= kzalloc_node(sizeof(*rtpn
), GFP_KERNEL
, tmp
);
3711 soft_limit_tree
.rb_tree_per_node
[node
] = rtpn
;
3713 for (zone
= 0; zone
< MAX_NR_ZONES
; zone
++) {
3714 rtpz
= &rtpn
->rb_tree_per_zone
[zone
];
3715 rtpz
->rb_root
= RB_ROOT
;
3716 spin_lock_init(&rtpz
->lock
);
3722 static struct cgroup_subsys_state
* __ref
3723 mem_cgroup_create(struct cgroup_subsys
*ss
, struct cgroup
*cont
)
3725 struct mem_cgroup
*mem
, *parent
;
3726 long error
= -ENOMEM
;
3729 mem
= mem_cgroup_alloc();
3731 return ERR_PTR(error
);
3733 for_each_node_state(node
, N_POSSIBLE
)
3734 if (alloc_mem_cgroup_per_zone_info(mem
, node
))
3738 if (cont
->parent
== NULL
) {
3740 enable_swap_cgroup();
3742 root_mem_cgroup
= mem
;
3743 if (mem_cgroup_soft_limit_tree_init())
3745 for_each_possible_cpu(cpu
) {
3746 struct memcg_stock_pcp
*stock
=
3747 &per_cpu(memcg_stock
, cpu
);
3748 INIT_WORK(&stock
->work
, drain_local_stock
);
3750 hotcpu_notifier(memcg_stock_cpu_callback
, 0);
3752 parent
= mem_cgroup_from_cont(cont
->parent
);
3753 mem
->use_hierarchy
= parent
->use_hierarchy
;
3756 if (parent
&& parent
->use_hierarchy
) {
3757 res_counter_init(&mem
->res
, &parent
->res
);
3758 res_counter_init(&mem
->memsw
, &parent
->memsw
);
3760 * We increment refcnt of the parent to ensure that we can
3761 * safely access it on res_counter_charge/uncharge.
3762 * This refcnt will be decremented when freeing this
3763 * mem_cgroup(see mem_cgroup_put).
3765 mem_cgroup_get(parent
);
3767 res_counter_init(&mem
->res
, NULL
);
3768 res_counter_init(&mem
->memsw
, NULL
);
3770 mem
->last_scanned_child
= 0;
3771 spin_lock_init(&mem
->reclaim_param_lock
);
3774 mem
->swappiness
= get_swappiness(parent
);
3775 atomic_set(&mem
->refcnt
, 1);
3776 mem
->move_charge_at_immigrate
= 0;
3777 mutex_init(&mem
->thresholds_lock
);
3780 __mem_cgroup_free(mem
);
3781 root_mem_cgroup
= NULL
;
3782 return ERR_PTR(error
);
3785 static int mem_cgroup_pre_destroy(struct cgroup_subsys
*ss
,
3786 struct cgroup
*cont
)
3788 struct mem_cgroup
*mem
= mem_cgroup_from_cont(cont
);
3790 return mem_cgroup_force_empty(mem
, false);
3793 static void mem_cgroup_destroy(struct cgroup_subsys
*ss
,
3794 struct cgroup
*cont
)
3796 struct mem_cgroup
*mem
= mem_cgroup_from_cont(cont
);
3798 mem_cgroup_put(mem
);
3801 static int mem_cgroup_populate(struct cgroup_subsys
*ss
,
3802 struct cgroup
*cont
)
3806 ret
= cgroup_add_files(cont
, ss
, mem_cgroup_files
,
3807 ARRAY_SIZE(mem_cgroup_files
));
3810 ret
= register_memsw_files(cont
, ss
);
3815 /* Handlers for move charge at task migration. */
3816 #define PRECHARGE_COUNT_AT_ONCE 256
3817 static int mem_cgroup_do_precharge(unsigned long count
)
3820 int batch_count
= PRECHARGE_COUNT_AT_ONCE
;
3821 struct mem_cgroup
*mem
= mc
.to
;
3823 if (mem_cgroup_is_root(mem
)) {
3824 mc
.precharge
+= count
;
3825 /* we don't need css_get for root */
3828 /* try to charge at once */
3830 struct res_counter
*dummy
;
3832 * "mem" cannot be under rmdir() because we've already checked
3833 * by cgroup_lock_live_cgroup() that it is not removed and we
3834 * are still under the same cgroup_mutex. So we can postpone
3837 if (res_counter_charge(&mem
->res
, PAGE_SIZE
* count
, &dummy
))
3839 if (do_swap_account
&& res_counter_charge(&mem
->memsw
,
3840 PAGE_SIZE
* count
, &dummy
)) {
3841 res_counter_uncharge(&mem
->res
, PAGE_SIZE
* count
);
3844 mc
.precharge
+= count
;
3845 VM_BUG_ON(test_bit(CSS_ROOT
, &mem
->css
.flags
));
3846 WARN_ON_ONCE(count
> INT_MAX
);
3847 __css_get(&mem
->css
, (int)count
);
3851 /* fall back to one by one charge */
3853 if (signal_pending(current
)) {
3857 if (!batch_count
--) {
3858 batch_count
= PRECHARGE_COUNT_AT_ONCE
;
3861 ret
= __mem_cgroup_try_charge(NULL
, GFP_KERNEL
, &mem
, false);
3863 /* mem_cgroup_clear_mc() will do uncharge later */
3869 #else /* !CONFIG_MMU */
3870 static int mem_cgroup_can_attach(struct cgroup_subsys
*ss
,
3871 struct cgroup
*cgroup
,
3872 struct task_struct
*p
,
3877 static void mem_cgroup_cancel_attach(struct cgroup_subsys
*ss
,
3878 struct cgroup
*cgroup
,
3879 struct task_struct
*p
,
3883 static void mem_cgroup_move_task(struct cgroup_subsys
*ss
,
3884 struct cgroup
*cont
,
3885 struct cgroup
*old_cont
,
3886 struct task_struct
*p
,
3893 * is_target_pte_for_mc - check a pte whether it is valid for move charge
3894 * @vma: the vma the pte to be checked belongs
3895 * @addr: the address corresponding to the pte to be checked
3896 * @ptent: the pte to be checked
3897 * @target: the pointer the target page or swap ent will be stored(can be NULL)
3900 * 0(MC_TARGET_NONE): if the pte is not a target for move charge.
3901 * 1(MC_TARGET_PAGE): if the page corresponding to this pte is a target for
3902 * move charge. if @target is not NULL, the page is stored in target->page
3903 * with extra refcnt got(Callers should handle it).
3904 * 2(MC_TARGET_SWAP): if the swap entry corresponding to this pte is a
3905 * target for charge migration. if @target is not NULL, the entry is stored
3908 * Called with pte lock held.
3915 enum mc_target_type
{
3916 MC_TARGET_NONE
, /* not used */
3921 static int is_target_pte_for_mc(struct vm_area_struct
*vma
,
3922 unsigned long addr
, pte_t ptent
, union mc_target
*target
)
3924 struct page
*page
= NULL
;
3925 struct page_cgroup
*pc
;
3927 swp_entry_t ent
= { .val
= 0 };
3928 int usage_count
= 0;
3929 bool move_anon
= test_bit(MOVE_CHARGE_TYPE_ANON
,
3930 &mc
.to
->move_charge_at_immigrate
);
3932 if (!pte_present(ptent
)) {
3933 /* TODO: handle swap of shmes/tmpfs */
3934 if (pte_none(ptent
) || pte_file(ptent
))
3936 else if (is_swap_pte(ptent
)) {
3937 ent
= pte_to_swp_entry(ptent
);
3938 if (!move_anon
|| non_swap_entry(ent
))
3940 usage_count
= mem_cgroup_count_swap_user(ent
, &page
);
3943 page
= vm_normal_page(vma
, addr
, ptent
);
3944 if (!page
|| !page_mapped(page
))
3947 * TODO: We don't move charges of file(including shmem/tmpfs)
3950 if (!move_anon
|| !PageAnon(page
))
3952 if (!get_page_unless_zero(page
))
3954 usage_count
= page_mapcount(page
);
3956 if (usage_count
> 1) {
3958 * TODO: We don't move charges of shared(used by multiple
3959 * processes) pages for now.
3966 pc
= lookup_page_cgroup(page
);
3968 * Do only loose check w/o page_cgroup lock.
3969 * mem_cgroup_move_account() checks the pc is valid or not under
3972 if (PageCgroupUsed(pc
) && pc
->mem_cgroup
== mc
.from
) {
3973 ret
= MC_TARGET_PAGE
;
3975 target
->page
= page
;
3977 if (!ret
|| !target
)
3981 if (ent
.val
&& do_swap_account
&& !ret
&&
3982 css_id(&mc
.from
->css
) == lookup_swap_cgroup(ent
)) {
3983 ret
= MC_TARGET_SWAP
;
3990 static int mem_cgroup_count_precharge_pte_range(pmd_t
*pmd
,
3991 unsigned long addr
, unsigned long end
,
3992 struct mm_walk
*walk
)
3994 struct vm_area_struct
*vma
= walk
->private;
3998 pte
= pte_offset_map_lock(vma
->vm_mm
, pmd
, addr
, &ptl
);
3999 for (; addr
!= end
; pte
++, addr
+= PAGE_SIZE
)
4000 if (is_target_pte_for_mc(vma
, addr
, *pte
, NULL
))
4001 mc
.precharge
++; /* increment precharge temporarily */
4002 pte_unmap_unlock(pte
- 1, ptl
);
4008 static unsigned long mem_cgroup_count_precharge(struct mm_struct
*mm
)
4010 unsigned long precharge
;
4011 struct vm_area_struct
*vma
;
4013 down_read(&mm
->mmap_sem
);
4014 for (vma
= mm
->mmap
; vma
; vma
= vma
->vm_next
) {
4015 struct mm_walk mem_cgroup_count_precharge_walk
= {
4016 .pmd_entry
= mem_cgroup_count_precharge_pte_range
,
4020 if (is_vm_hugetlb_page(vma
))
4022 /* TODO: We don't move charges of shmem/tmpfs pages for now. */
4023 if (vma
->vm_flags
& VM_SHARED
)
4025 walk_page_range(vma
->vm_start
, vma
->vm_end
,
4026 &mem_cgroup_count_precharge_walk
);
4028 up_read(&mm
->mmap_sem
);
4030 precharge
= mc
.precharge
;
4036 static int mem_cgroup_precharge_mc(struct mm_struct
*mm
)
4038 return mem_cgroup_do_precharge(mem_cgroup_count_precharge(mm
));
4041 static void mem_cgroup_clear_mc(void)
4043 /* we must uncharge all the leftover precharges from mc.to */
4045 __mem_cgroup_cancel_charge(mc
.to
, mc
.precharge
);
4049 * we didn't uncharge from mc.from at mem_cgroup_move_account(), so
4050 * we must uncharge here.
4052 if (mc
.moved_charge
) {
4053 __mem_cgroup_cancel_charge(mc
.from
, mc
.moved_charge
);
4054 mc
.moved_charge
= 0;
4056 /* we must fixup refcnts and charges */
4057 if (mc
.moved_swap
) {
4058 WARN_ON_ONCE(mc
.moved_swap
> INT_MAX
);
4059 /* uncharge swap account from the old cgroup */
4060 if (!mem_cgroup_is_root(mc
.from
))
4061 res_counter_uncharge(&mc
.from
->memsw
,
4062 PAGE_SIZE
* mc
.moved_swap
);
4063 __mem_cgroup_put(mc
.from
, mc
.moved_swap
);
4065 if (!mem_cgroup_is_root(mc
.to
)) {
4067 * we charged both to->res and to->memsw, so we should
4070 res_counter_uncharge(&mc
.to
->res
,
4071 PAGE_SIZE
* mc
.moved_swap
);
4072 VM_BUG_ON(test_bit(CSS_ROOT
, &mc
.to
->css
.flags
));
4073 __css_put(&mc
.to
->css
, mc
.moved_swap
);
4075 /* we've already done mem_cgroup_get(mc.to) */
4081 mc
.moving_task
= NULL
;
4082 wake_up_all(&mc
.waitq
);
4085 static int mem_cgroup_can_attach(struct cgroup_subsys
*ss
,
4086 struct cgroup
*cgroup
,
4087 struct task_struct
*p
,
4091 struct mem_cgroup
*mem
= mem_cgroup_from_cont(cgroup
);
4093 if (mem
->move_charge_at_immigrate
) {
4094 struct mm_struct
*mm
;
4095 struct mem_cgroup
*from
= mem_cgroup_from_task(p
);
4097 VM_BUG_ON(from
== mem
);
4099 mm
= get_task_mm(p
);
4102 /* We move charges only when we move a owner of the mm */
4103 if (mm
->owner
== p
) {
4106 VM_BUG_ON(mc
.precharge
);
4107 VM_BUG_ON(mc
.moved_charge
);
4108 VM_BUG_ON(mc
.moved_swap
);
4109 VM_BUG_ON(mc
.moving_task
);
4113 mc
.moved_charge
= 0;
4115 mc
.moving_task
= current
;
4117 ret
= mem_cgroup_precharge_mc(mm
);
4119 mem_cgroup_clear_mc();
4126 static void mem_cgroup_cancel_attach(struct cgroup_subsys
*ss
,
4127 struct cgroup
*cgroup
,
4128 struct task_struct
*p
,
4131 mem_cgroup_clear_mc();
4134 static int mem_cgroup_move_charge_pte_range(pmd_t
*pmd
,
4135 unsigned long addr
, unsigned long end
,
4136 struct mm_walk
*walk
)
4139 struct vm_area_struct
*vma
= walk
->private;
4144 pte
= pte_offset_map_lock(vma
->vm_mm
, pmd
, addr
, &ptl
);
4145 for (; addr
!= end
; addr
+= PAGE_SIZE
) {
4146 pte_t ptent
= *(pte
++);
4147 union mc_target target
;
4150 struct page_cgroup
*pc
;
4156 type
= is_target_pte_for_mc(vma
, addr
, ptent
, &target
);
4158 case MC_TARGET_PAGE
:
4160 if (isolate_lru_page(page
))
4162 pc
= lookup_page_cgroup(page
);
4163 if (!mem_cgroup_move_account(pc
,
4164 mc
.from
, mc
.to
, false)) {
4166 /* we uncharge from mc.from later. */
4169 putback_lru_page(page
);
4170 put
: /* is_target_pte_for_mc() gets the page */
4173 case MC_TARGET_SWAP
:
4175 if (!mem_cgroup_move_swap_account(ent
,
4176 mc
.from
, mc
.to
, false)) {
4178 /* we fixup refcnts and charges later. */
4186 pte_unmap_unlock(pte
- 1, ptl
);
4191 * We have consumed all precharges we got in can_attach().
4192 * We try charge one by one, but don't do any additional
4193 * charges to mc.to if we have failed in charge once in attach()
4196 ret
= mem_cgroup_do_precharge(1);
4204 static void mem_cgroup_move_charge(struct mm_struct
*mm
)
4206 struct vm_area_struct
*vma
;
4208 lru_add_drain_all();
4209 down_read(&mm
->mmap_sem
);
4210 for (vma
= mm
->mmap
; vma
; vma
= vma
->vm_next
) {
4212 struct mm_walk mem_cgroup_move_charge_walk
= {
4213 .pmd_entry
= mem_cgroup_move_charge_pte_range
,
4217 if (is_vm_hugetlb_page(vma
))
4219 /* TODO: We don't move charges of shmem/tmpfs pages for now. */
4220 if (vma
->vm_flags
& VM_SHARED
)
4222 ret
= walk_page_range(vma
->vm_start
, vma
->vm_end
,
4223 &mem_cgroup_move_charge_walk
);
4226 * means we have consumed all precharges and failed in
4227 * doing additional charge. Just abandon here.
4231 up_read(&mm
->mmap_sem
);
4234 static void mem_cgroup_move_task(struct cgroup_subsys
*ss
,
4235 struct cgroup
*cont
,
4236 struct cgroup
*old_cont
,
4237 struct task_struct
*p
,
4240 struct mm_struct
*mm
;
4243 /* no need to move charge */
4246 mm
= get_task_mm(p
);
4248 mem_cgroup_move_charge(mm
);
4251 mem_cgroup_clear_mc();
4254 struct cgroup_subsys mem_cgroup_subsys
= {
4256 .subsys_id
= mem_cgroup_subsys_id
,
4257 .create
= mem_cgroup_create
,
4258 .pre_destroy
= mem_cgroup_pre_destroy
,
4259 .destroy
= mem_cgroup_destroy
,
4260 .populate
= mem_cgroup_populate
,
4261 .can_attach
= mem_cgroup_can_attach
,
4262 .cancel_attach
= mem_cgroup_cancel_attach
,
4263 .attach
= mem_cgroup_move_task
,
4268 #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP
4270 static int __init
disable_swap_account(char *s
)
4272 really_do_swap_account
= 0;
4275 __setup("noswapaccount", disable_swap_account
);