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?
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 static int mem_cgroup_oom_lock_cb(struct mem_cgroup
*mem
, void *data
)
1251 int *val
= (int *)data
;
1254 * Logically, we can stop scanning immediately when we find
1255 * a memcg is already locked. But condidering unlock ops and
1256 * creation/removal of memcg, scan-all is simple operation.
1258 x
= atomic_inc_return(&mem
->oom_lock
);
1259 *val
= max(x
, *val
);
1263 * Check OOM-Killer is already running under our hierarchy.
1264 * If someone is running, return false.
1266 static bool mem_cgroup_oom_lock(struct mem_cgroup
*mem
)
1270 mem_cgroup_walk_tree(mem
, &lock_count
, mem_cgroup_oom_lock_cb
);
1272 if (lock_count
== 1)
1277 static int mem_cgroup_oom_unlock_cb(struct mem_cgroup
*mem
, void *data
)
1280 * When a new child is created while the hierarchy is under oom,
1281 * mem_cgroup_oom_lock() may not be called. We have to use
1282 * atomic_add_unless() here.
1284 atomic_add_unless(&mem
->oom_lock
, -1, 0);
1288 static void mem_cgroup_oom_unlock(struct mem_cgroup
*mem
)
1290 mem_cgroup_walk_tree(mem
, NULL
, mem_cgroup_oom_unlock_cb
);
1293 static DEFINE_MUTEX(memcg_oom_mutex
);
1294 static DECLARE_WAIT_QUEUE_HEAD(memcg_oom_waitq
);
1297 * try to call OOM killer. returns false if we should exit memory-reclaim loop.
1299 bool mem_cgroup_handle_oom(struct mem_cgroup
*mem
, gfp_t mask
)
1304 /* At first, try to OOM lock hierarchy under mem.*/
1305 mutex_lock(&memcg_oom_mutex
);
1306 locked
= mem_cgroup_oom_lock(mem
);
1308 * Even if signal_pending(), we can't quit charge() loop without
1309 * accounting. So, UNINTERRUPTIBLE is appropriate. But SIGKILL
1310 * under OOM is always welcomed, use TASK_KILLABLE here.
1313 prepare_to_wait(&memcg_oom_waitq
, &wait
, TASK_KILLABLE
);
1314 mutex_unlock(&memcg_oom_mutex
);
1317 mem_cgroup_out_of_memory(mem
, mask
);
1320 finish_wait(&memcg_oom_waitq
, &wait
);
1322 mutex_lock(&memcg_oom_mutex
);
1323 mem_cgroup_oom_unlock(mem
);
1325 * Here, we use global waitq .....more fine grained waitq ?
1326 * Assume following hierarchy.
1330 * assume OOM happens both in A and 01 at the same time. Tthey are
1331 * mutually exclusive by lock. (kill in 01 helps A.)
1332 * When we use per memcg waitq, we have to wake up waiters on A and 02
1333 * in addtion to waiters on 01. We use global waitq for avoiding mess.
1334 * It will not be a big problem.
1335 * (And a task may be moved to other groups while it's waiting for OOM.)
1337 wake_up_all(&memcg_oom_waitq
);
1338 mutex_unlock(&memcg_oom_mutex
);
1340 if (test_thread_flag(TIF_MEMDIE
) || fatal_signal_pending(current
))
1342 /* Give chance to dying process */
1343 schedule_timeout(1);
1348 * Currently used to update mapped file statistics, but the routine can be
1349 * generalized to update other statistics as well.
1351 void mem_cgroup_update_file_mapped(struct page
*page
, int val
)
1353 struct mem_cgroup
*mem
;
1354 struct page_cgroup
*pc
;
1356 pc
= lookup_page_cgroup(page
);
1360 lock_page_cgroup(pc
);
1361 mem
= pc
->mem_cgroup
;
1365 if (!PageCgroupUsed(pc
))
1369 * Preemption is already disabled. We can use __this_cpu_xxx
1371 __this_cpu_add(mem
->stat
->count
[MEM_CGROUP_STAT_FILE_MAPPED
], val
);
1374 unlock_page_cgroup(pc
);
1378 * size of first charge trial. "32" comes from vmscan.c's magic value.
1379 * TODO: maybe necessary to use big numbers in big irons.
1381 #define CHARGE_SIZE (32 * PAGE_SIZE)
1382 struct memcg_stock_pcp
{
1383 struct mem_cgroup
*cached
; /* this never be root cgroup */
1385 struct work_struct work
;
1387 static DEFINE_PER_CPU(struct memcg_stock_pcp
, memcg_stock
);
1388 static atomic_t memcg_drain_count
;
1391 * Try to consume stocked charge on this cpu. If success, PAGE_SIZE is consumed
1392 * from local stock and true is returned. If the stock is 0 or charges from a
1393 * cgroup which is not current target, returns false. This stock will be
1396 static bool consume_stock(struct mem_cgroup
*mem
)
1398 struct memcg_stock_pcp
*stock
;
1401 stock
= &get_cpu_var(memcg_stock
);
1402 if (mem
== stock
->cached
&& stock
->charge
)
1403 stock
->charge
-= PAGE_SIZE
;
1404 else /* need to call res_counter_charge */
1406 put_cpu_var(memcg_stock
);
1411 * Returns stocks cached in percpu to res_counter and reset cached information.
1413 static void drain_stock(struct memcg_stock_pcp
*stock
)
1415 struct mem_cgroup
*old
= stock
->cached
;
1417 if (stock
->charge
) {
1418 res_counter_uncharge(&old
->res
, stock
->charge
);
1419 if (do_swap_account
)
1420 res_counter_uncharge(&old
->memsw
, stock
->charge
);
1422 stock
->cached
= NULL
;
1427 * This must be called under preempt disabled or must be called by
1428 * a thread which is pinned to local cpu.
1430 static void drain_local_stock(struct work_struct
*dummy
)
1432 struct memcg_stock_pcp
*stock
= &__get_cpu_var(memcg_stock
);
1437 * Cache charges(val) which is from res_counter, to local per_cpu area.
1438 * This will be consumed by consumt_stock() function, later.
1440 static void refill_stock(struct mem_cgroup
*mem
, int val
)
1442 struct memcg_stock_pcp
*stock
= &get_cpu_var(memcg_stock
);
1444 if (stock
->cached
!= mem
) { /* reset if necessary */
1446 stock
->cached
= mem
;
1448 stock
->charge
+= val
;
1449 put_cpu_var(memcg_stock
);
1453 * Tries to drain stocked charges in other cpus. This function is asynchronous
1454 * and just put a work per cpu for draining localy on each cpu. Caller can
1455 * expects some charges will be back to res_counter later but cannot wait for
1458 static void drain_all_stock_async(void)
1461 /* This function is for scheduling "drain" in asynchronous way.
1462 * The result of "drain" is not directly handled by callers. Then,
1463 * if someone is calling drain, we don't have to call drain more.
1464 * Anyway, WORK_STRUCT_PENDING check in queue_work_on() will catch if
1465 * there is a race. We just do loose check here.
1467 if (atomic_read(&memcg_drain_count
))
1469 /* Notify other cpus that system-wide "drain" is running */
1470 atomic_inc(&memcg_drain_count
);
1472 for_each_online_cpu(cpu
) {
1473 struct memcg_stock_pcp
*stock
= &per_cpu(memcg_stock
, cpu
);
1474 schedule_work_on(cpu
, &stock
->work
);
1477 atomic_dec(&memcg_drain_count
);
1478 /* We don't wait for flush_work */
1481 /* This is a synchronous drain interface. */
1482 static void drain_all_stock_sync(void)
1484 /* called when force_empty is called */
1485 atomic_inc(&memcg_drain_count
);
1486 schedule_on_each_cpu(drain_local_stock
);
1487 atomic_dec(&memcg_drain_count
);
1490 static int __cpuinit
memcg_stock_cpu_callback(struct notifier_block
*nb
,
1491 unsigned long action
,
1494 int cpu
= (unsigned long)hcpu
;
1495 struct memcg_stock_pcp
*stock
;
1497 if (action
!= CPU_DEAD
)
1499 stock
= &per_cpu(memcg_stock
, cpu
);
1505 * Unlike exported interface, "oom" parameter is added. if oom==true,
1506 * oom-killer can be invoked.
1508 static int __mem_cgroup_try_charge(struct mm_struct
*mm
,
1509 gfp_t gfp_mask
, struct mem_cgroup
**memcg
, bool oom
)
1511 struct mem_cgroup
*mem
, *mem_over_limit
;
1512 int nr_retries
= MEM_CGROUP_RECLAIM_RETRIES
;
1513 struct res_counter
*fail_res
;
1514 int csize
= CHARGE_SIZE
;
1517 * Unlike gloval-vm's OOM-kill, we're not in memory shortage
1518 * in system level. So, allow to go ahead dying process in addition to
1521 if (unlikely(test_thread_flag(TIF_MEMDIE
)
1522 || fatal_signal_pending(current
)))
1526 * We always charge the cgroup the mm_struct belongs to.
1527 * The mm_struct's mem_cgroup changes on task migration if the
1528 * thread group leader migrates. It's possible that mm is not
1529 * set, if so charge the init_mm (happens for pagecache usage).
1533 mem
= try_get_mem_cgroup_from_mm(mm
);
1541 VM_BUG_ON(css_is_removed(&mem
->css
));
1542 if (mem_cgroup_is_root(mem
))
1547 unsigned long flags
= 0;
1549 if (consume_stock(mem
))
1552 ret
= res_counter_charge(&mem
->res
, csize
, &fail_res
);
1554 if (!do_swap_account
)
1556 ret
= res_counter_charge(&mem
->memsw
, csize
, &fail_res
);
1559 /* mem+swap counter fails */
1560 res_counter_uncharge(&mem
->res
, csize
);
1561 flags
|= MEM_CGROUP_RECLAIM_NOSWAP
;
1562 mem_over_limit
= mem_cgroup_from_res_counter(fail_res
,
1565 /* mem counter fails */
1566 mem_over_limit
= mem_cgroup_from_res_counter(fail_res
,
1569 /* reduce request size and retry */
1570 if (csize
> PAGE_SIZE
) {
1574 if (!(gfp_mask
& __GFP_WAIT
))
1577 ret
= mem_cgroup_hierarchical_reclaim(mem_over_limit
, NULL
,
1583 * try_to_free_mem_cgroup_pages() might not give us a full
1584 * picture of reclaim. Some pages are reclaimed and might be
1585 * moved to swap cache or just unmapped from the cgroup.
1586 * Check the limit again to see if the reclaim reduced the
1587 * current usage of the cgroup before giving up
1590 if (mem_cgroup_check_under_limit(mem_over_limit
))
1593 /* try to avoid oom while someone is moving charge */
1594 if (mc
.moving_task
&& current
!= mc
.moving_task
) {
1595 struct mem_cgroup
*from
, *to
;
1596 bool do_continue
= false;
1598 * There is a small race that "from" or "to" can be
1599 * freed by rmdir, so we use css_tryget().
1604 if (from
&& css_tryget(&from
->css
)) {
1605 if (mem_over_limit
->use_hierarchy
)
1606 do_continue
= css_is_ancestor(
1608 &mem_over_limit
->css
);
1610 do_continue
= (from
== mem_over_limit
);
1611 css_put(&from
->css
);
1613 if (!do_continue
&& to
&& css_tryget(&to
->css
)) {
1614 if (mem_over_limit
->use_hierarchy
)
1615 do_continue
= css_is_ancestor(
1617 &mem_over_limit
->css
);
1619 do_continue
= (to
== mem_over_limit
);
1625 prepare_to_wait(&mc
.waitq
, &wait
,
1626 TASK_INTERRUPTIBLE
);
1627 /* moving charge context might have finished. */
1630 finish_wait(&mc
.waitq
, &wait
);
1635 if (!nr_retries
--) {
1638 if (mem_cgroup_handle_oom(mem_over_limit
, gfp_mask
)) {
1639 nr_retries
= MEM_CGROUP_RECLAIM_RETRIES
;
1642 /* When we reach here, current task is dying .*/
1647 if (csize
> PAGE_SIZE
)
1648 refill_stock(mem
, csize
- PAGE_SIZE
);
1660 * Somemtimes we have to undo a charge we got by try_charge().
1661 * This function is for that and do uncharge, put css's refcnt.
1662 * gotten by try_charge().
1664 static void __mem_cgroup_cancel_charge(struct mem_cgroup
*mem
,
1665 unsigned long count
)
1667 if (!mem_cgroup_is_root(mem
)) {
1668 res_counter_uncharge(&mem
->res
, PAGE_SIZE
* count
);
1669 if (do_swap_account
)
1670 res_counter_uncharge(&mem
->memsw
, PAGE_SIZE
* count
);
1671 VM_BUG_ON(test_bit(CSS_ROOT
, &mem
->css
.flags
));
1672 WARN_ON_ONCE(count
> INT_MAX
);
1673 __css_put(&mem
->css
, (int)count
);
1675 /* we don't need css_put for root */
1678 static void mem_cgroup_cancel_charge(struct mem_cgroup
*mem
)
1680 __mem_cgroup_cancel_charge(mem
, 1);
1684 * A helper function to get mem_cgroup from ID. must be called under
1685 * rcu_read_lock(). The caller must check css_is_removed() or some if
1686 * it's concern. (dropping refcnt from swap can be called against removed
1689 static struct mem_cgroup
*mem_cgroup_lookup(unsigned short id
)
1691 struct cgroup_subsys_state
*css
;
1693 /* ID 0 is unused ID */
1696 css
= css_lookup(&mem_cgroup_subsys
, id
);
1699 return container_of(css
, struct mem_cgroup
, css
);
1702 struct mem_cgroup
*try_get_mem_cgroup_from_page(struct page
*page
)
1704 struct mem_cgroup
*mem
= NULL
;
1705 struct page_cgroup
*pc
;
1709 VM_BUG_ON(!PageLocked(page
));
1711 pc
= lookup_page_cgroup(page
);
1712 lock_page_cgroup(pc
);
1713 if (PageCgroupUsed(pc
)) {
1714 mem
= pc
->mem_cgroup
;
1715 if (mem
&& !css_tryget(&mem
->css
))
1717 } else if (PageSwapCache(page
)) {
1718 ent
.val
= page_private(page
);
1719 id
= lookup_swap_cgroup(ent
);
1721 mem
= mem_cgroup_lookup(id
);
1722 if (mem
&& !css_tryget(&mem
->css
))
1726 unlock_page_cgroup(pc
);
1731 * commit a charge got by __mem_cgroup_try_charge() and makes page_cgroup to be
1732 * USED state. If already USED, uncharge and return.
1735 static void __mem_cgroup_commit_charge(struct mem_cgroup
*mem
,
1736 struct page_cgroup
*pc
,
1737 enum charge_type ctype
)
1739 /* try_charge() can return NULL to *memcg, taking care of it. */
1743 lock_page_cgroup(pc
);
1744 if (unlikely(PageCgroupUsed(pc
))) {
1745 unlock_page_cgroup(pc
);
1746 mem_cgroup_cancel_charge(mem
);
1750 pc
->mem_cgroup
= mem
;
1752 * We access a page_cgroup asynchronously without lock_page_cgroup().
1753 * Especially when a page_cgroup is taken from a page, pc->mem_cgroup
1754 * is accessed after testing USED bit. To make pc->mem_cgroup visible
1755 * before USED bit, we need memory barrier here.
1756 * See mem_cgroup_add_lru_list(), etc.
1760 case MEM_CGROUP_CHARGE_TYPE_CACHE
:
1761 case MEM_CGROUP_CHARGE_TYPE_SHMEM
:
1762 SetPageCgroupCache(pc
);
1763 SetPageCgroupUsed(pc
);
1765 case MEM_CGROUP_CHARGE_TYPE_MAPPED
:
1766 ClearPageCgroupCache(pc
);
1767 SetPageCgroupUsed(pc
);
1773 mem_cgroup_charge_statistics(mem
, pc
, true);
1775 unlock_page_cgroup(pc
);
1777 * "charge_statistics" updated event counter. Then, check it.
1778 * Insert ancestor (and ancestor's ancestors), to softlimit RB-tree.
1779 * if they exceeds softlimit.
1781 memcg_check_events(mem
, pc
->page
);
1785 * __mem_cgroup_move_account - move account of the page
1786 * @pc: page_cgroup of the page.
1787 * @from: mem_cgroup which the page is moved from.
1788 * @to: mem_cgroup which the page is moved to. @from != @to.
1789 * @uncharge: whether we should call uncharge and css_put against @from.
1791 * The caller must confirm following.
1792 * - page is not on LRU (isolate_page() is useful.)
1793 * - the pc is locked, used, and ->mem_cgroup points to @from.
1795 * This function doesn't do "charge" nor css_get to new cgroup. It should be
1796 * done by a caller(__mem_cgroup_try_charge would be usefull). If @uncharge is
1797 * true, this function does "uncharge" from old cgroup, but it doesn't if
1798 * @uncharge is false, so a caller should do "uncharge".
1801 static void __mem_cgroup_move_account(struct page_cgroup
*pc
,
1802 struct mem_cgroup
*from
, struct mem_cgroup
*to
, bool uncharge
)
1806 VM_BUG_ON(from
== to
);
1807 VM_BUG_ON(PageLRU(pc
->page
));
1808 VM_BUG_ON(!PageCgroupLocked(pc
));
1809 VM_BUG_ON(!PageCgroupUsed(pc
));
1810 VM_BUG_ON(pc
->mem_cgroup
!= from
);
1813 if (page_mapped(page
) && !PageAnon(page
)) {
1814 /* Update mapped_file data for mem_cgroup */
1816 __this_cpu_dec(from
->stat
->count
[MEM_CGROUP_STAT_FILE_MAPPED
]);
1817 __this_cpu_inc(to
->stat
->count
[MEM_CGROUP_STAT_FILE_MAPPED
]);
1820 mem_cgroup_charge_statistics(from
, pc
, false);
1822 /* This is not "cancel", but cancel_charge does all we need. */
1823 mem_cgroup_cancel_charge(from
);
1825 /* caller should have done css_get */
1826 pc
->mem_cgroup
= to
;
1827 mem_cgroup_charge_statistics(to
, pc
, true);
1829 * We charges against "to" which may not have any tasks. Then, "to"
1830 * can be under rmdir(). But in current implementation, caller of
1831 * this function is just force_empty() and move charge, so it's
1832 * garanteed that "to" is never removed. So, we don't check rmdir
1838 * check whether the @pc is valid for moving account and call
1839 * __mem_cgroup_move_account()
1841 static int mem_cgroup_move_account(struct page_cgroup
*pc
,
1842 struct mem_cgroup
*from
, struct mem_cgroup
*to
, bool uncharge
)
1845 lock_page_cgroup(pc
);
1846 if (PageCgroupUsed(pc
) && pc
->mem_cgroup
== from
) {
1847 __mem_cgroup_move_account(pc
, from
, to
, uncharge
);
1850 unlock_page_cgroup(pc
);
1854 memcg_check_events(to
, pc
->page
);
1855 memcg_check_events(from
, pc
->page
);
1860 * move charges to its parent.
1863 static int mem_cgroup_move_parent(struct page_cgroup
*pc
,
1864 struct mem_cgroup
*child
,
1867 struct page
*page
= pc
->page
;
1868 struct cgroup
*cg
= child
->css
.cgroup
;
1869 struct cgroup
*pcg
= cg
->parent
;
1870 struct mem_cgroup
*parent
;
1878 if (!get_page_unless_zero(page
))
1880 if (isolate_lru_page(page
))
1883 parent
= mem_cgroup_from_cont(pcg
);
1884 ret
= __mem_cgroup_try_charge(NULL
, gfp_mask
, &parent
, false);
1888 ret
= mem_cgroup_move_account(pc
, child
, parent
, true);
1890 mem_cgroup_cancel_charge(parent
);
1892 putback_lru_page(page
);
1900 * Charge the memory controller for page usage.
1902 * 0 if the charge was successful
1903 * < 0 if the cgroup is over its limit
1905 static int mem_cgroup_charge_common(struct page
*page
, struct mm_struct
*mm
,
1906 gfp_t gfp_mask
, enum charge_type ctype
,
1907 struct mem_cgroup
*memcg
)
1909 struct mem_cgroup
*mem
;
1910 struct page_cgroup
*pc
;
1913 pc
= lookup_page_cgroup(page
);
1914 /* can happen at boot */
1920 ret
= __mem_cgroup_try_charge(mm
, gfp_mask
, &mem
, true);
1924 __mem_cgroup_commit_charge(mem
, pc
, ctype
);
1928 int mem_cgroup_newpage_charge(struct page
*page
,
1929 struct mm_struct
*mm
, gfp_t gfp_mask
)
1931 if (mem_cgroup_disabled())
1933 if (PageCompound(page
))
1936 * If already mapped, we don't have to account.
1937 * If page cache, page->mapping has address_space.
1938 * But page->mapping may have out-of-use anon_vma pointer,
1939 * detecit it by PageAnon() check. newly-mapped-anon's page->mapping
1942 if (page_mapped(page
) || (page
->mapping
&& !PageAnon(page
)))
1946 return mem_cgroup_charge_common(page
, mm
, gfp_mask
,
1947 MEM_CGROUP_CHARGE_TYPE_MAPPED
, NULL
);
1951 __mem_cgroup_commit_charge_swapin(struct page
*page
, struct mem_cgroup
*ptr
,
1952 enum charge_type ctype
);
1954 int mem_cgroup_cache_charge(struct page
*page
, struct mm_struct
*mm
,
1957 struct mem_cgroup
*mem
= NULL
;
1960 if (mem_cgroup_disabled())
1962 if (PageCompound(page
))
1965 * Corner case handling. This is called from add_to_page_cache()
1966 * in usual. But some FS (shmem) precharges this page before calling it
1967 * and call add_to_page_cache() with GFP_NOWAIT.
1969 * For GFP_NOWAIT case, the page may be pre-charged before calling
1970 * add_to_page_cache(). (See shmem.c) check it here and avoid to call
1971 * charge twice. (It works but has to pay a bit larger cost.)
1972 * And when the page is SwapCache, it should take swap information
1973 * into account. This is under lock_page() now.
1975 if (!(gfp_mask
& __GFP_WAIT
)) {
1976 struct page_cgroup
*pc
;
1979 pc
= lookup_page_cgroup(page
);
1982 lock_page_cgroup(pc
);
1983 if (PageCgroupUsed(pc
)) {
1984 unlock_page_cgroup(pc
);
1987 unlock_page_cgroup(pc
);
1990 if (unlikely(!mm
&& !mem
))
1993 if (page_is_file_cache(page
))
1994 return mem_cgroup_charge_common(page
, mm
, gfp_mask
,
1995 MEM_CGROUP_CHARGE_TYPE_CACHE
, NULL
);
1998 if (PageSwapCache(page
)) {
1999 ret
= mem_cgroup_try_charge_swapin(mm
, page
, gfp_mask
, &mem
);
2001 __mem_cgroup_commit_charge_swapin(page
, mem
,
2002 MEM_CGROUP_CHARGE_TYPE_SHMEM
);
2004 ret
= mem_cgroup_charge_common(page
, mm
, gfp_mask
,
2005 MEM_CGROUP_CHARGE_TYPE_SHMEM
, mem
);
2011 * While swap-in, try_charge -> commit or cancel, the page is locked.
2012 * And when try_charge() successfully returns, one refcnt to memcg without
2013 * struct page_cgroup is acquired. This refcnt will be consumed by
2014 * "commit()" or removed by "cancel()"
2016 int mem_cgroup_try_charge_swapin(struct mm_struct
*mm
,
2018 gfp_t mask
, struct mem_cgroup
**ptr
)
2020 struct mem_cgroup
*mem
;
2023 if (mem_cgroup_disabled())
2026 if (!do_swap_account
)
2029 * A racing thread's fault, or swapoff, may have already updated
2030 * the pte, and even removed page from swap cache: in those cases
2031 * do_swap_page()'s pte_same() test will fail; but there's also a
2032 * KSM case which does need to charge the page.
2034 if (!PageSwapCache(page
))
2036 mem
= try_get_mem_cgroup_from_page(page
);
2040 ret
= __mem_cgroup_try_charge(NULL
, mask
, ptr
, true);
2041 /* drop extra refcnt from tryget */
2047 return __mem_cgroup_try_charge(mm
, mask
, ptr
, true);
2051 __mem_cgroup_commit_charge_swapin(struct page
*page
, struct mem_cgroup
*ptr
,
2052 enum charge_type ctype
)
2054 struct page_cgroup
*pc
;
2056 if (mem_cgroup_disabled())
2060 cgroup_exclude_rmdir(&ptr
->css
);
2061 pc
= lookup_page_cgroup(page
);
2062 mem_cgroup_lru_del_before_commit_swapcache(page
);
2063 __mem_cgroup_commit_charge(ptr
, pc
, ctype
);
2064 mem_cgroup_lru_add_after_commit_swapcache(page
);
2066 * Now swap is on-memory. This means this page may be
2067 * counted both as mem and swap....double count.
2068 * Fix it by uncharging from memsw. Basically, this SwapCache is stable
2069 * under lock_page(). But in do_swap_page()::memory.c, reuse_swap_page()
2070 * may call delete_from_swap_cache() before reach here.
2072 if (do_swap_account
&& PageSwapCache(page
)) {
2073 swp_entry_t ent
= {.val
= page_private(page
)};
2075 struct mem_cgroup
*memcg
;
2077 id
= swap_cgroup_record(ent
, 0);
2079 memcg
= mem_cgroup_lookup(id
);
2082 * This recorded memcg can be obsolete one. So, avoid
2083 * calling css_tryget
2085 if (!mem_cgroup_is_root(memcg
))
2086 res_counter_uncharge(&memcg
->memsw
, PAGE_SIZE
);
2087 mem_cgroup_swap_statistics(memcg
, false);
2088 mem_cgroup_put(memcg
);
2093 * At swapin, we may charge account against cgroup which has no tasks.
2094 * So, rmdir()->pre_destroy() can be called while we do this charge.
2095 * In that case, we need to call pre_destroy() again. check it here.
2097 cgroup_release_and_wakeup_rmdir(&ptr
->css
);
2100 void mem_cgroup_commit_charge_swapin(struct page
*page
, struct mem_cgroup
*ptr
)
2102 __mem_cgroup_commit_charge_swapin(page
, ptr
,
2103 MEM_CGROUP_CHARGE_TYPE_MAPPED
);
2106 void mem_cgroup_cancel_charge_swapin(struct mem_cgroup
*mem
)
2108 if (mem_cgroup_disabled())
2112 mem_cgroup_cancel_charge(mem
);
2116 __do_uncharge(struct mem_cgroup
*mem
, const enum charge_type ctype
)
2118 struct memcg_batch_info
*batch
= NULL
;
2119 bool uncharge_memsw
= true;
2120 /* If swapout, usage of swap doesn't decrease */
2121 if (!do_swap_account
|| ctype
== MEM_CGROUP_CHARGE_TYPE_SWAPOUT
)
2122 uncharge_memsw
= false;
2124 * do_batch > 0 when unmapping pages or inode invalidate/truncate.
2125 * In those cases, all pages freed continously can be expected to be in
2126 * the same cgroup and we have chance to coalesce uncharges.
2127 * But we do uncharge one by one if this is killed by OOM(TIF_MEMDIE)
2128 * because we want to do uncharge as soon as possible.
2130 if (!current
->memcg_batch
.do_batch
|| test_thread_flag(TIF_MEMDIE
))
2131 goto direct_uncharge
;
2133 batch
= ¤t
->memcg_batch
;
2135 * In usual, we do css_get() when we remember memcg pointer.
2136 * But in this case, we keep res->usage until end of a series of
2137 * uncharges. Then, it's ok to ignore memcg's refcnt.
2142 * In typical case, batch->memcg == mem. This means we can
2143 * merge a series of uncharges to an uncharge of res_counter.
2144 * If not, we uncharge res_counter ony by one.
2146 if (batch
->memcg
!= mem
)
2147 goto direct_uncharge
;
2148 /* remember freed charge and uncharge it later */
2149 batch
->bytes
+= PAGE_SIZE
;
2151 batch
->memsw_bytes
+= PAGE_SIZE
;
2154 res_counter_uncharge(&mem
->res
, PAGE_SIZE
);
2156 res_counter_uncharge(&mem
->memsw
, PAGE_SIZE
);
2161 * uncharge if !page_mapped(page)
2163 static struct mem_cgroup
*
2164 __mem_cgroup_uncharge_common(struct page
*page
, enum charge_type ctype
)
2166 struct page_cgroup
*pc
;
2167 struct mem_cgroup
*mem
= NULL
;
2168 struct mem_cgroup_per_zone
*mz
;
2170 if (mem_cgroup_disabled())
2173 if (PageSwapCache(page
))
2177 * Check if our page_cgroup is valid
2179 pc
= lookup_page_cgroup(page
);
2180 if (unlikely(!pc
|| !PageCgroupUsed(pc
)))
2183 lock_page_cgroup(pc
);
2185 mem
= pc
->mem_cgroup
;
2187 if (!PageCgroupUsed(pc
))
2191 case MEM_CGROUP_CHARGE_TYPE_MAPPED
:
2192 case MEM_CGROUP_CHARGE_TYPE_DROP
:
2193 if (page_mapped(page
))
2196 case MEM_CGROUP_CHARGE_TYPE_SWAPOUT
:
2197 if (!PageAnon(page
)) { /* Shared memory */
2198 if (page
->mapping
&& !page_is_file_cache(page
))
2200 } else if (page_mapped(page
)) /* Anon */
2207 if (!mem_cgroup_is_root(mem
))
2208 __do_uncharge(mem
, ctype
);
2209 if (ctype
== MEM_CGROUP_CHARGE_TYPE_SWAPOUT
)
2210 mem_cgroup_swap_statistics(mem
, true);
2211 mem_cgroup_charge_statistics(mem
, pc
, false);
2213 ClearPageCgroupUsed(pc
);
2215 * pc->mem_cgroup is not cleared here. It will be accessed when it's
2216 * freed from LRU. This is safe because uncharged page is expected not
2217 * to be reused (freed soon). Exception is SwapCache, it's handled by
2218 * special functions.
2221 mz
= page_cgroup_zoneinfo(pc
);
2222 unlock_page_cgroup(pc
);
2224 memcg_check_events(mem
, page
);
2225 /* at swapout, this memcg will be accessed to record to swap */
2226 if (ctype
!= MEM_CGROUP_CHARGE_TYPE_SWAPOUT
)
2232 unlock_page_cgroup(pc
);
2236 void mem_cgroup_uncharge_page(struct page
*page
)
2239 if (page_mapped(page
))
2241 if (page
->mapping
&& !PageAnon(page
))
2243 __mem_cgroup_uncharge_common(page
, MEM_CGROUP_CHARGE_TYPE_MAPPED
);
2246 void mem_cgroup_uncharge_cache_page(struct page
*page
)
2248 VM_BUG_ON(page_mapped(page
));
2249 VM_BUG_ON(page
->mapping
);
2250 __mem_cgroup_uncharge_common(page
, MEM_CGROUP_CHARGE_TYPE_CACHE
);
2254 * Batch_start/batch_end is called in unmap_page_range/invlidate/trucate.
2255 * In that cases, pages are freed continuously and we can expect pages
2256 * are in the same memcg. All these calls itself limits the number of
2257 * pages freed at once, then uncharge_start/end() is called properly.
2258 * This may be called prural(2) times in a context,
2261 void mem_cgroup_uncharge_start(void)
2263 current
->memcg_batch
.do_batch
++;
2264 /* We can do nest. */
2265 if (current
->memcg_batch
.do_batch
== 1) {
2266 current
->memcg_batch
.memcg
= NULL
;
2267 current
->memcg_batch
.bytes
= 0;
2268 current
->memcg_batch
.memsw_bytes
= 0;
2272 void mem_cgroup_uncharge_end(void)
2274 struct memcg_batch_info
*batch
= ¤t
->memcg_batch
;
2276 if (!batch
->do_batch
)
2280 if (batch
->do_batch
) /* If stacked, do nothing. */
2286 * This "batch->memcg" is valid without any css_get/put etc...
2287 * bacause we hide charges behind us.
2290 res_counter_uncharge(&batch
->memcg
->res
, batch
->bytes
);
2291 if (batch
->memsw_bytes
)
2292 res_counter_uncharge(&batch
->memcg
->memsw
, batch
->memsw_bytes
);
2293 /* forget this pointer (for sanity check) */
2294 batch
->memcg
= NULL
;
2299 * called after __delete_from_swap_cache() and drop "page" account.
2300 * memcg information is recorded to swap_cgroup of "ent"
2303 mem_cgroup_uncharge_swapcache(struct page
*page
, swp_entry_t ent
, bool swapout
)
2305 struct mem_cgroup
*memcg
;
2306 int ctype
= MEM_CGROUP_CHARGE_TYPE_SWAPOUT
;
2308 if (!swapout
) /* this was a swap cache but the swap is unused ! */
2309 ctype
= MEM_CGROUP_CHARGE_TYPE_DROP
;
2311 memcg
= __mem_cgroup_uncharge_common(page
, ctype
);
2313 /* record memcg information */
2314 if (do_swap_account
&& swapout
&& memcg
) {
2315 swap_cgroup_record(ent
, css_id(&memcg
->css
));
2316 mem_cgroup_get(memcg
);
2318 if (swapout
&& memcg
)
2319 css_put(&memcg
->css
);
2323 #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP
2325 * called from swap_entry_free(). remove record in swap_cgroup and
2326 * uncharge "memsw" account.
2328 void mem_cgroup_uncharge_swap(swp_entry_t ent
)
2330 struct mem_cgroup
*memcg
;
2333 if (!do_swap_account
)
2336 id
= swap_cgroup_record(ent
, 0);
2338 memcg
= mem_cgroup_lookup(id
);
2341 * We uncharge this because swap is freed.
2342 * This memcg can be obsolete one. We avoid calling css_tryget
2344 if (!mem_cgroup_is_root(memcg
))
2345 res_counter_uncharge(&memcg
->memsw
, PAGE_SIZE
);
2346 mem_cgroup_swap_statistics(memcg
, false);
2347 mem_cgroup_put(memcg
);
2353 * mem_cgroup_move_swap_account - move swap charge and swap_cgroup's record.
2354 * @entry: swap entry to be moved
2355 * @from: mem_cgroup which the entry is moved from
2356 * @to: mem_cgroup which the entry is moved to
2357 * @need_fixup: whether we should fixup res_counters and refcounts.
2359 * It succeeds only when the swap_cgroup's record for this entry is the same
2360 * as the mem_cgroup's id of @from.
2362 * Returns 0 on success, -EINVAL on failure.
2364 * The caller must have charged to @to, IOW, called res_counter_charge() about
2365 * both res and memsw, and called css_get().
2367 static int mem_cgroup_move_swap_account(swp_entry_t entry
,
2368 struct mem_cgroup
*from
, struct mem_cgroup
*to
, bool need_fixup
)
2370 unsigned short old_id
, new_id
;
2372 old_id
= css_id(&from
->css
);
2373 new_id
= css_id(&to
->css
);
2375 if (swap_cgroup_cmpxchg(entry
, old_id
, new_id
) == old_id
) {
2376 mem_cgroup_swap_statistics(from
, false);
2377 mem_cgroup_swap_statistics(to
, true);
2379 * This function is only called from task migration context now.
2380 * It postpones res_counter and refcount handling till the end
2381 * of task migration(mem_cgroup_clear_mc()) for performance
2382 * improvement. But we cannot postpone mem_cgroup_get(to)
2383 * because if the process that has been moved to @to does
2384 * swap-in, the refcount of @to might be decreased to 0.
2388 if (!mem_cgroup_is_root(from
))
2389 res_counter_uncharge(&from
->memsw
, PAGE_SIZE
);
2390 mem_cgroup_put(from
);
2392 * we charged both to->res and to->memsw, so we should
2395 if (!mem_cgroup_is_root(to
))
2396 res_counter_uncharge(&to
->res
, PAGE_SIZE
);
2404 static inline int mem_cgroup_move_swap_account(swp_entry_t entry
,
2405 struct mem_cgroup
*from
, struct mem_cgroup
*to
, bool need_fixup
)
2412 * Before starting migration, account PAGE_SIZE to mem_cgroup that the old
2415 int mem_cgroup_prepare_migration(struct page
*page
, struct mem_cgroup
**ptr
)
2417 struct page_cgroup
*pc
;
2418 struct mem_cgroup
*mem
= NULL
;
2421 if (mem_cgroup_disabled())
2424 pc
= lookup_page_cgroup(page
);
2425 lock_page_cgroup(pc
);
2426 if (PageCgroupUsed(pc
)) {
2427 mem
= pc
->mem_cgroup
;
2430 unlock_page_cgroup(pc
);
2433 ret
= __mem_cgroup_try_charge(NULL
, GFP_KERNEL
, &mem
, false);
2440 /* remove redundant charge if migration failed*/
2441 void mem_cgroup_end_migration(struct mem_cgroup
*mem
,
2442 struct page
*oldpage
, struct page
*newpage
)
2444 struct page
*target
, *unused
;
2445 struct page_cgroup
*pc
;
2446 enum charge_type ctype
;
2450 cgroup_exclude_rmdir(&mem
->css
);
2451 /* at migration success, oldpage->mapping is NULL. */
2452 if (oldpage
->mapping
) {
2460 if (PageAnon(target
))
2461 ctype
= MEM_CGROUP_CHARGE_TYPE_MAPPED
;
2462 else if (page_is_file_cache(target
))
2463 ctype
= MEM_CGROUP_CHARGE_TYPE_CACHE
;
2465 ctype
= MEM_CGROUP_CHARGE_TYPE_SHMEM
;
2467 /* unused page is not on radix-tree now. */
2469 __mem_cgroup_uncharge_common(unused
, ctype
);
2471 pc
= lookup_page_cgroup(target
);
2473 * __mem_cgroup_commit_charge() check PCG_USED bit of page_cgroup.
2474 * So, double-counting is effectively avoided.
2476 __mem_cgroup_commit_charge(mem
, pc
, ctype
);
2479 * Both of oldpage and newpage are still under lock_page().
2480 * Then, we don't have to care about race in radix-tree.
2481 * But we have to be careful that this page is unmapped or not.
2483 * There is a case for !page_mapped(). At the start of
2484 * migration, oldpage was mapped. But now, it's zapped.
2485 * But we know *target* page is not freed/reused under us.
2486 * mem_cgroup_uncharge_page() does all necessary checks.
2488 if (ctype
== MEM_CGROUP_CHARGE_TYPE_MAPPED
)
2489 mem_cgroup_uncharge_page(target
);
2491 * At migration, we may charge account against cgroup which has no tasks
2492 * So, rmdir()->pre_destroy() can be called while we do this charge.
2493 * In that case, we need to call pre_destroy() again. check it here.
2495 cgroup_release_and_wakeup_rmdir(&mem
->css
);
2499 * A call to try to shrink memory usage on charge failure at shmem's swapin.
2500 * Calling hierarchical_reclaim is not enough because we should update
2501 * last_oom_jiffies to prevent pagefault_out_of_memory from invoking global OOM.
2502 * Moreover considering hierarchy, we should reclaim from the mem_over_limit,
2503 * not from the memcg which this page would be charged to.
2504 * try_charge_swapin does all of these works properly.
2506 int mem_cgroup_shmem_charge_fallback(struct page
*page
,
2507 struct mm_struct
*mm
,
2510 struct mem_cgroup
*mem
= NULL
;
2513 if (mem_cgroup_disabled())
2516 ret
= mem_cgroup_try_charge_swapin(mm
, page
, gfp_mask
, &mem
);
2518 mem_cgroup_cancel_charge_swapin(mem
); /* it does !mem check */
2523 static DEFINE_MUTEX(set_limit_mutex
);
2525 static int mem_cgroup_resize_limit(struct mem_cgroup
*memcg
,
2526 unsigned long long val
)
2531 int children
= mem_cgroup_count_children(memcg
);
2532 u64 curusage
, oldusage
;
2535 * For keeping hierarchical_reclaim simple, how long we should retry
2536 * is depends on callers. We set our retry-count to be function
2537 * of # of children which we should visit in this loop.
2539 retry_count
= MEM_CGROUP_RECLAIM_RETRIES
* children
;
2541 oldusage
= res_counter_read_u64(&memcg
->res
, RES_USAGE
);
2543 while (retry_count
) {
2544 if (signal_pending(current
)) {
2549 * Rather than hide all in some function, I do this in
2550 * open coded manner. You see what this really does.
2551 * We have to guarantee mem->res.limit < mem->memsw.limit.
2553 mutex_lock(&set_limit_mutex
);
2554 memswlimit
= res_counter_read_u64(&memcg
->memsw
, RES_LIMIT
);
2555 if (memswlimit
< val
) {
2557 mutex_unlock(&set_limit_mutex
);
2560 ret
= res_counter_set_limit(&memcg
->res
, val
);
2562 if (memswlimit
== val
)
2563 memcg
->memsw_is_minimum
= true;
2565 memcg
->memsw_is_minimum
= false;
2567 mutex_unlock(&set_limit_mutex
);
2572 mem_cgroup_hierarchical_reclaim(memcg
, NULL
, GFP_KERNEL
,
2573 MEM_CGROUP_RECLAIM_SHRINK
);
2574 curusage
= res_counter_read_u64(&memcg
->res
, RES_USAGE
);
2575 /* Usage is reduced ? */
2576 if (curusage
>= oldusage
)
2579 oldusage
= curusage
;
2585 static int mem_cgroup_resize_memsw_limit(struct mem_cgroup
*memcg
,
2586 unsigned long long val
)
2589 u64 memlimit
, oldusage
, curusage
;
2590 int children
= mem_cgroup_count_children(memcg
);
2593 /* see mem_cgroup_resize_res_limit */
2594 retry_count
= children
* MEM_CGROUP_RECLAIM_RETRIES
;
2595 oldusage
= res_counter_read_u64(&memcg
->memsw
, RES_USAGE
);
2596 while (retry_count
) {
2597 if (signal_pending(current
)) {
2602 * Rather than hide all in some function, I do this in
2603 * open coded manner. You see what this really does.
2604 * We have to guarantee mem->res.limit < mem->memsw.limit.
2606 mutex_lock(&set_limit_mutex
);
2607 memlimit
= res_counter_read_u64(&memcg
->res
, RES_LIMIT
);
2608 if (memlimit
> val
) {
2610 mutex_unlock(&set_limit_mutex
);
2613 ret
= res_counter_set_limit(&memcg
->memsw
, val
);
2615 if (memlimit
== val
)
2616 memcg
->memsw_is_minimum
= true;
2618 memcg
->memsw_is_minimum
= false;
2620 mutex_unlock(&set_limit_mutex
);
2625 mem_cgroup_hierarchical_reclaim(memcg
, NULL
, GFP_KERNEL
,
2626 MEM_CGROUP_RECLAIM_NOSWAP
|
2627 MEM_CGROUP_RECLAIM_SHRINK
);
2628 curusage
= res_counter_read_u64(&memcg
->memsw
, RES_USAGE
);
2629 /* Usage is reduced ? */
2630 if (curusage
>= oldusage
)
2633 oldusage
= curusage
;
2638 unsigned long mem_cgroup_soft_limit_reclaim(struct zone
*zone
, int order
,
2639 gfp_t gfp_mask
, int nid
,
2642 unsigned long nr_reclaimed
= 0;
2643 struct mem_cgroup_per_zone
*mz
, *next_mz
= NULL
;
2644 unsigned long reclaimed
;
2646 struct mem_cgroup_tree_per_zone
*mctz
;
2647 unsigned long long excess
;
2652 mctz
= soft_limit_tree_node_zone(nid
, zid
);
2654 * This loop can run a while, specially if mem_cgroup's continuously
2655 * keep exceeding their soft limit and putting the system under
2662 mz
= mem_cgroup_largest_soft_limit_node(mctz
);
2666 reclaimed
= mem_cgroup_hierarchical_reclaim(mz
->mem
, zone
,
2668 MEM_CGROUP_RECLAIM_SOFT
);
2669 nr_reclaimed
+= reclaimed
;
2670 spin_lock(&mctz
->lock
);
2673 * If we failed to reclaim anything from this memory cgroup
2674 * it is time to move on to the next cgroup
2680 * Loop until we find yet another one.
2682 * By the time we get the soft_limit lock
2683 * again, someone might have aded the
2684 * group back on the RB tree. Iterate to
2685 * make sure we get a different mem.
2686 * mem_cgroup_largest_soft_limit_node returns
2687 * NULL if no other cgroup is present on
2691 __mem_cgroup_largest_soft_limit_node(mctz
);
2692 if (next_mz
== mz
) {
2693 css_put(&next_mz
->mem
->css
);
2695 } else /* next_mz == NULL or other memcg */
2699 __mem_cgroup_remove_exceeded(mz
->mem
, mz
, mctz
);
2700 excess
= res_counter_soft_limit_excess(&mz
->mem
->res
);
2702 * One school of thought says that we should not add
2703 * back the node to the tree if reclaim returns 0.
2704 * But our reclaim could return 0, simply because due
2705 * to priority we are exposing a smaller subset of
2706 * memory to reclaim from. Consider this as a longer
2709 /* If excess == 0, no tree ops */
2710 __mem_cgroup_insert_exceeded(mz
->mem
, mz
, mctz
, excess
);
2711 spin_unlock(&mctz
->lock
);
2712 css_put(&mz
->mem
->css
);
2715 * Could not reclaim anything and there are no more
2716 * mem cgroups to try or we seem to be looping without
2717 * reclaiming anything.
2719 if (!nr_reclaimed
&&
2721 loop
> MEM_CGROUP_MAX_SOFT_LIMIT_RECLAIM_LOOPS
))
2723 } while (!nr_reclaimed
);
2725 css_put(&next_mz
->mem
->css
);
2726 return nr_reclaimed
;
2730 * This routine traverse page_cgroup in given list and drop them all.
2731 * *And* this routine doesn't reclaim page itself, just removes page_cgroup.
2733 static int mem_cgroup_force_empty_list(struct mem_cgroup
*mem
,
2734 int node
, int zid
, enum lru_list lru
)
2737 struct mem_cgroup_per_zone
*mz
;
2738 struct page_cgroup
*pc
, *busy
;
2739 unsigned long flags
, loop
;
2740 struct list_head
*list
;
2743 zone
= &NODE_DATA(node
)->node_zones
[zid
];
2744 mz
= mem_cgroup_zoneinfo(mem
, node
, zid
);
2745 list
= &mz
->lists
[lru
];
2747 loop
= MEM_CGROUP_ZSTAT(mz
, lru
);
2748 /* give some margin against EBUSY etc...*/
2753 spin_lock_irqsave(&zone
->lru_lock
, flags
);
2754 if (list_empty(list
)) {
2755 spin_unlock_irqrestore(&zone
->lru_lock
, flags
);
2758 pc
= list_entry(list
->prev
, struct page_cgroup
, lru
);
2760 list_move(&pc
->lru
, list
);
2762 spin_unlock_irqrestore(&zone
->lru_lock
, flags
);
2765 spin_unlock_irqrestore(&zone
->lru_lock
, flags
);
2767 ret
= mem_cgroup_move_parent(pc
, mem
, GFP_KERNEL
);
2771 if (ret
== -EBUSY
|| ret
== -EINVAL
) {
2772 /* found lock contention or "pc" is obsolete. */
2779 if (!ret
&& !list_empty(list
))
2785 * make mem_cgroup's charge to be 0 if there is no task.
2786 * This enables deleting this mem_cgroup.
2788 static int mem_cgroup_force_empty(struct mem_cgroup
*mem
, bool free_all
)
2791 int node
, zid
, shrink
;
2792 int nr_retries
= MEM_CGROUP_RECLAIM_RETRIES
;
2793 struct cgroup
*cgrp
= mem
->css
.cgroup
;
2798 /* should free all ? */
2804 if (cgroup_task_count(cgrp
) || !list_empty(&cgrp
->children
))
2807 if (signal_pending(current
))
2809 /* This is for making all *used* pages to be on LRU. */
2810 lru_add_drain_all();
2811 drain_all_stock_sync();
2813 for_each_node_state(node
, N_HIGH_MEMORY
) {
2814 for (zid
= 0; !ret
&& zid
< MAX_NR_ZONES
; zid
++) {
2817 ret
= mem_cgroup_force_empty_list(mem
,
2826 /* it seems parent cgroup doesn't have enough mem */
2830 /* "ret" should also be checked to ensure all lists are empty. */
2831 } while (mem
->res
.usage
> 0 || ret
);
2837 /* returns EBUSY if there is a task or if we come here twice. */
2838 if (cgroup_task_count(cgrp
) || !list_empty(&cgrp
->children
) || shrink
) {
2842 /* we call try-to-free pages for make this cgroup empty */
2843 lru_add_drain_all();
2844 /* try to free all pages in this cgroup */
2846 while (nr_retries
&& mem
->res
.usage
> 0) {
2849 if (signal_pending(current
)) {
2853 progress
= try_to_free_mem_cgroup_pages(mem
, GFP_KERNEL
,
2854 false, get_swappiness(mem
));
2857 /* maybe some writeback is necessary */
2858 congestion_wait(BLK_RW_ASYNC
, HZ
/10);
2863 /* try move_account...there may be some *locked* pages. */
2867 int mem_cgroup_force_empty_write(struct cgroup
*cont
, unsigned int event
)
2869 return mem_cgroup_force_empty(mem_cgroup_from_cont(cont
), true);
2873 static u64
mem_cgroup_hierarchy_read(struct cgroup
*cont
, struct cftype
*cft
)
2875 return mem_cgroup_from_cont(cont
)->use_hierarchy
;
2878 static int mem_cgroup_hierarchy_write(struct cgroup
*cont
, struct cftype
*cft
,
2882 struct mem_cgroup
*mem
= mem_cgroup_from_cont(cont
);
2883 struct cgroup
*parent
= cont
->parent
;
2884 struct mem_cgroup
*parent_mem
= NULL
;
2887 parent_mem
= mem_cgroup_from_cont(parent
);
2891 * If parent's use_hierarchy is set, we can't make any modifications
2892 * in the child subtrees. If it is unset, then the change can
2893 * occur, provided the current cgroup has no children.
2895 * For the root cgroup, parent_mem is NULL, we allow value to be
2896 * set if there are no children.
2898 if ((!parent_mem
|| !parent_mem
->use_hierarchy
) &&
2899 (val
== 1 || val
== 0)) {
2900 if (list_empty(&cont
->children
))
2901 mem
->use_hierarchy
= val
;
2911 struct mem_cgroup_idx_data
{
2913 enum mem_cgroup_stat_index idx
;
2917 mem_cgroup_get_idx_stat(struct mem_cgroup
*mem
, void *data
)
2919 struct mem_cgroup_idx_data
*d
= data
;
2920 d
->val
+= mem_cgroup_read_stat(mem
, d
->idx
);
2925 mem_cgroup_get_recursive_idx_stat(struct mem_cgroup
*mem
,
2926 enum mem_cgroup_stat_index idx
, s64
*val
)
2928 struct mem_cgroup_idx_data d
;
2931 mem_cgroup_walk_tree(mem
, &d
, mem_cgroup_get_idx_stat
);
2935 static inline u64
mem_cgroup_usage(struct mem_cgroup
*mem
, bool swap
)
2939 if (!mem_cgroup_is_root(mem
)) {
2941 return res_counter_read_u64(&mem
->res
, RES_USAGE
);
2943 return res_counter_read_u64(&mem
->memsw
, RES_USAGE
);
2946 mem_cgroup_get_recursive_idx_stat(mem
, MEM_CGROUP_STAT_CACHE
, &idx_val
);
2948 mem_cgroup_get_recursive_idx_stat(mem
, MEM_CGROUP_STAT_RSS
, &idx_val
);
2952 mem_cgroup_get_recursive_idx_stat(mem
,
2953 MEM_CGROUP_STAT_SWAPOUT
, &idx_val
);
2957 return val
<< PAGE_SHIFT
;
2960 static u64
mem_cgroup_read(struct cgroup
*cont
, struct cftype
*cft
)
2962 struct mem_cgroup
*mem
= mem_cgroup_from_cont(cont
);
2966 type
= MEMFILE_TYPE(cft
->private);
2967 name
= MEMFILE_ATTR(cft
->private);
2970 if (name
== RES_USAGE
)
2971 val
= mem_cgroup_usage(mem
, false);
2973 val
= res_counter_read_u64(&mem
->res
, name
);
2976 if (name
== RES_USAGE
)
2977 val
= mem_cgroup_usage(mem
, true);
2979 val
= res_counter_read_u64(&mem
->memsw
, name
);
2988 * The user of this function is...
2991 static int mem_cgroup_write(struct cgroup
*cont
, struct cftype
*cft
,
2994 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cont
);
2996 unsigned long long val
;
2999 type
= MEMFILE_TYPE(cft
->private);
3000 name
= MEMFILE_ATTR(cft
->private);
3003 if (mem_cgroup_is_root(memcg
)) { /* Can't set limit on root */
3007 /* This function does all necessary parse...reuse it */
3008 ret
= res_counter_memparse_write_strategy(buffer
, &val
);
3012 ret
= mem_cgroup_resize_limit(memcg
, val
);
3014 ret
= mem_cgroup_resize_memsw_limit(memcg
, val
);
3016 case RES_SOFT_LIMIT
:
3017 ret
= res_counter_memparse_write_strategy(buffer
, &val
);
3021 * For memsw, soft limits are hard to implement in terms
3022 * of semantics, for now, we support soft limits for
3023 * control without swap
3026 ret
= res_counter_set_soft_limit(&memcg
->res
, val
);
3031 ret
= -EINVAL
; /* should be BUG() ? */
3037 static void memcg_get_hierarchical_limit(struct mem_cgroup
*memcg
,
3038 unsigned long long *mem_limit
, unsigned long long *memsw_limit
)
3040 struct cgroup
*cgroup
;
3041 unsigned long long min_limit
, min_memsw_limit
, tmp
;
3043 min_limit
= res_counter_read_u64(&memcg
->res
, RES_LIMIT
);
3044 min_memsw_limit
= res_counter_read_u64(&memcg
->memsw
, RES_LIMIT
);
3045 cgroup
= memcg
->css
.cgroup
;
3046 if (!memcg
->use_hierarchy
)
3049 while (cgroup
->parent
) {
3050 cgroup
= cgroup
->parent
;
3051 memcg
= mem_cgroup_from_cont(cgroup
);
3052 if (!memcg
->use_hierarchy
)
3054 tmp
= res_counter_read_u64(&memcg
->res
, RES_LIMIT
);
3055 min_limit
= min(min_limit
, tmp
);
3056 tmp
= res_counter_read_u64(&memcg
->memsw
, RES_LIMIT
);
3057 min_memsw_limit
= min(min_memsw_limit
, tmp
);
3060 *mem_limit
= min_limit
;
3061 *memsw_limit
= min_memsw_limit
;
3065 static int mem_cgroup_reset(struct cgroup
*cont
, unsigned int event
)
3067 struct mem_cgroup
*mem
;
3070 mem
= mem_cgroup_from_cont(cont
);
3071 type
= MEMFILE_TYPE(event
);
3072 name
= MEMFILE_ATTR(event
);
3076 res_counter_reset_max(&mem
->res
);
3078 res_counter_reset_max(&mem
->memsw
);
3082 res_counter_reset_failcnt(&mem
->res
);
3084 res_counter_reset_failcnt(&mem
->memsw
);
3091 static u64
mem_cgroup_move_charge_read(struct cgroup
*cgrp
,
3094 return mem_cgroup_from_cont(cgrp
)->move_charge_at_immigrate
;
3098 static int mem_cgroup_move_charge_write(struct cgroup
*cgrp
,
3099 struct cftype
*cft
, u64 val
)
3101 struct mem_cgroup
*mem
= mem_cgroup_from_cont(cgrp
);
3103 if (val
>= (1 << NR_MOVE_TYPE
))
3106 * We check this value several times in both in can_attach() and
3107 * attach(), so we need cgroup lock to prevent this value from being
3111 mem
->move_charge_at_immigrate
= val
;
3117 static int mem_cgroup_move_charge_write(struct cgroup
*cgrp
,
3118 struct cftype
*cft
, u64 val
)
3125 /* For read statistics */
3141 struct mcs_total_stat
{
3142 s64 stat
[NR_MCS_STAT
];
3148 } memcg_stat_strings
[NR_MCS_STAT
] = {
3149 {"cache", "total_cache"},
3150 {"rss", "total_rss"},
3151 {"mapped_file", "total_mapped_file"},
3152 {"pgpgin", "total_pgpgin"},
3153 {"pgpgout", "total_pgpgout"},
3154 {"swap", "total_swap"},
3155 {"inactive_anon", "total_inactive_anon"},
3156 {"active_anon", "total_active_anon"},
3157 {"inactive_file", "total_inactive_file"},
3158 {"active_file", "total_active_file"},
3159 {"unevictable", "total_unevictable"}
3163 static int mem_cgroup_get_local_stat(struct mem_cgroup
*mem
, void *data
)
3165 struct mcs_total_stat
*s
= data
;
3169 val
= mem_cgroup_read_stat(mem
, MEM_CGROUP_STAT_CACHE
);
3170 s
->stat
[MCS_CACHE
] += val
* PAGE_SIZE
;
3171 val
= mem_cgroup_read_stat(mem
, MEM_CGROUP_STAT_RSS
);
3172 s
->stat
[MCS_RSS
] += val
* PAGE_SIZE
;
3173 val
= mem_cgroup_read_stat(mem
, MEM_CGROUP_STAT_FILE_MAPPED
);
3174 s
->stat
[MCS_FILE_MAPPED
] += val
* PAGE_SIZE
;
3175 val
= mem_cgroup_read_stat(mem
, MEM_CGROUP_STAT_PGPGIN_COUNT
);
3176 s
->stat
[MCS_PGPGIN
] += val
;
3177 val
= mem_cgroup_read_stat(mem
, MEM_CGROUP_STAT_PGPGOUT_COUNT
);
3178 s
->stat
[MCS_PGPGOUT
] += val
;
3179 if (do_swap_account
) {
3180 val
= mem_cgroup_read_stat(mem
, MEM_CGROUP_STAT_SWAPOUT
);
3181 s
->stat
[MCS_SWAP
] += val
* PAGE_SIZE
;
3185 val
= mem_cgroup_get_local_zonestat(mem
, LRU_INACTIVE_ANON
);
3186 s
->stat
[MCS_INACTIVE_ANON
] += val
* PAGE_SIZE
;
3187 val
= mem_cgroup_get_local_zonestat(mem
, LRU_ACTIVE_ANON
);
3188 s
->stat
[MCS_ACTIVE_ANON
] += val
* PAGE_SIZE
;
3189 val
= mem_cgroup_get_local_zonestat(mem
, LRU_INACTIVE_FILE
);
3190 s
->stat
[MCS_INACTIVE_FILE
] += val
* PAGE_SIZE
;
3191 val
= mem_cgroup_get_local_zonestat(mem
, LRU_ACTIVE_FILE
);
3192 s
->stat
[MCS_ACTIVE_FILE
] += val
* PAGE_SIZE
;
3193 val
= mem_cgroup_get_local_zonestat(mem
, LRU_UNEVICTABLE
);
3194 s
->stat
[MCS_UNEVICTABLE
] += val
* PAGE_SIZE
;
3199 mem_cgroup_get_total_stat(struct mem_cgroup
*mem
, struct mcs_total_stat
*s
)
3201 mem_cgroup_walk_tree(mem
, s
, mem_cgroup_get_local_stat
);
3204 static int mem_control_stat_show(struct cgroup
*cont
, struct cftype
*cft
,
3205 struct cgroup_map_cb
*cb
)
3207 struct mem_cgroup
*mem_cont
= mem_cgroup_from_cont(cont
);
3208 struct mcs_total_stat mystat
;
3211 memset(&mystat
, 0, sizeof(mystat
));
3212 mem_cgroup_get_local_stat(mem_cont
, &mystat
);
3214 for (i
= 0; i
< NR_MCS_STAT
; i
++) {
3215 if (i
== MCS_SWAP
&& !do_swap_account
)
3217 cb
->fill(cb
, memcg_stat_strings
[i
].local_name
, mystat
.stat
[i
]);
3220 /* Hierarchical information */
3222 unsigned long long limit
, memsw_limit
;
3223 memcg_get_hierarchical_limit(mem_cont
, &limit
, &memsw_limit
);
3224 cb
->fill(cb
, "hierarchical_memory_limit", limit
);
3225 if (do_swap_account
)
3226 cb
->fill(cb
, "hierarchical_memsw_limit", memsw_limit
);
3229 memset(&mystat
, 0, sizeof(mystat
));
3230 mem_cgroup_get_total_stat(mem_cont
, &mystat
);
3231 for (i
= 0; i
< NR_MCS_STAT
; i
++) {
3232 if (i
== MCS_SWAP
&& !do_swap_account
)
3234 cb
->fill(cb
, memcg_stat_strings
[i
].total_name
, mystat
.stat
[i
]);
3237 #ifdef CONFIG_DEBUG_VM
3238 cb
->fill(cb
, "inactive_ratio", calc_inactive_ratio(mem_cont
, NULL
));
3242 struct mem_cgroup_per_zone
*mz
;
3243 unsigned long recent_rotated
[2] = {0, 0};
3244 unsigned long recent_scanned
[2] = {0, 0};
3246 for_each_online_node(nid
)
3247 for (zid
= 0; zid
< MAX_NR_ZONES
; zid
++) {
3248 mz
= mem_cgroup_zoneinfo(mem_cont
, nid
, zid
);
3250 recent_rotated
[0] +=
3251 mz
->reclaim_stat
.recent_rotated
[0];
3252 recent_rotated
[1] +=
3253 mz
->reclaim_stat
.recent_rotated
[1];
3254 recent_scanned
[0] +=
3255 mz
->reclaim_stat
.recent_scanned
[0];
3256 recent_scanned
[1] +=
3257 mz
->reclaim_stat
.recent_scanned
[1];
3259 cb
->fill(cb
, "recent_rotated_anon", recent_rotated
[0]);
3260 cb
->fill(cb
, "recent_rotated_file", recent_rotated
[1]);
3261 cb
->fill(cb
, "recent_scanned_anon", recent_scanned
[0]);
3262 cb
->fill(cb
, "recent_scanned_file", recent_scanned
[1]);
3269 static u64
mem_cgroup_swappiness_read(struct cgroup
*cgrp
, struct cftype
*cft
)
3271 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cgrp
);
3273 return get_swappiness(memcg
);
3276 static int mem_cgroup_swappiness_write(struct cgroup
*cgrp
, struct cftype
*cft
,
3279 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cgrp
);
3280 struct mem_cgroup
*parent
;
3285 if (cgrp
->parent
== NULL
)
3288 parent
= mem_cgroup_from_cont(cgrp
->parent
);
3292 /* If under hierarchy, only empty-root can set this value */
3293 if ((parent
->use_hierarchy
) ||
3294 (memcg
->use_hierarchy
&& !list_empty(&cgrp
->children
))) {
3299 spin_lock(&memcg
->reclaim_param_lock
);
3300 memcg
->swappiness
= val
;
3301 spin_unlock(&memcg
->reclaim_param_lock
);
3308 static void __mem_cgroup_threshold(struct mem_cgroup
*memcg
, bool swap
)
3310 struct mem_cgroup_threshold_ary
*t
;
3316 t
= rcu_dereference(memcg
->thresholds
);
3318 t
= rcu_dereference(memcg
->memsw_thresholds
);
3323 usage
= mem_cgroup_usage(memcg
, swap
);
3326 * current_threshold points to threshold just below usage.
3327 * If it's not true, a threshold was crossed after last
3328 * call of __mem_cgroup_threshold().
3330 i
= atomic_read(&t
->current_threshold
);
3333 * Iterate backward over array of thresholds starting from
3334 * current_threshold and check if a threshold is crossed.
3335 * If none of thresholds below usage is crossed, we read
3336 * only one element of the array here.
3338 for (; i
>= 0 && unlikely(t
->entries
[i
].threshold
> usage
); i
--)
3339 eventfd_signal(t
->entries
[i
].eventfd
, 1);
3341 /* i = current_threshold + 1 */
3345 * Iterate forward over array of thresholds starting from
3346 * current_threshold+1 and check if a threshold is crossed.
3347 * If none of thresholds above usage is crossed, we read
3348 * only one element of the array here.
3350 for (; i
< t
->size
&& unlikely(t
->entries
[i
].threshold
<= usage
); i
++)
3351 eventfd_signal(t
->entries
[i
].eventfd
, 1);
3353 /* Update current_threshold */
3354 atomic_set(&t
->current_threshold
, i
- 1);
3359 static void mem_cgroup_threshold(struct mem_cgroup
*memcg
)
3361 __mem_cgroup_threshold(memcg
, false);
3362 if (do_swap_account
)
3363 __mem_cgroup_threshold(memcg
, true);
3366 static int compare_thresholds(const void *a
, const void *b
)
3368 const struct mem_cgroup_threshold
*_a
= a
;
3369 const struct mem_cgroup_threshold
*_b
= b
;
3371 return _a
->threshold
- _b
->threshold
;
3374 static int mem_cgroup_register_event(struct cgroup
*cgrp
, struct cftype
*cft
,
3375 struct eventfd_ctx
*eventfd
, const char *args
)
3377 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cgrp
);
3378 struct mem_cgroup_threshold_ary
*thresholds
, *thresholds_new
;
3379 int type
= MEMFILE_TYPE(cft
->private);
3380 u64 threshold
, usage
;
3384 ret
= res_counter_memparse_write_strategy(args
, &threshold
);
3388 mutex_lock(&memcg
->thresholds_lock
);
3390 thresholds
= memcg
->thresholds
;
3391 else if (type
== _MEMSWAP
)
3392 thresholds
= memcg
->memsw_thresholds
;
3396 usage
= mem_cgroup_usage(memcg
, type
== _MEMSWAP
);
3398 /* Check if a threshold crossed before adding a new one */
3400 __mem_cgroup_threshold(memcg
, type
== _MEMSWAP
);
3403 size
= thresholds
->size
+ 1;
3407 /* Allocate memory for new array of thresholds */
3408 thresholds_new
= kmalloc(sizeof(*thresholds_new
) +
3409 size
* sizeof(struct mem_cgroup_threshold
),
3411 if (!thresholds_new
) {
3415 thresholds_new
->size
= size
;
3417 /* Copy thresholds (if any) to new array */
3419 memcpy(thresholds_new
->entries
, thresholds
->entries
,
3421 sizeof(struct mem_cgroup_threshold
));
3422 /* Add new threshold */
3423 thresholds_new
->entries
[size
- 1].eventfd
= eventfd
;
3424 thresholds_new
->entries
[size
- 1].threshold
= threshold
;
3426 /* Sort thresholds. Registering of new threshold isn't time-critical */
3427 sort(thresholds_new
->entries
, size
,
3428 sizeof(struct mem_cgroup_threshold
),
3429 compare_thresholds
, NULL
);
3431 /* Find current threshold */
3432 atomic_set(&thresholds_new
->current_threshold
, -1);
3433 for (i
= 0; i
< size
; i
++) {
3434 if (thresholds_new
->entries
[i
].threshold
< usage
) {
3436 * thresholds_new->current_threshold will not be used
3437 * until rcu_assign_pointer(), so it's safe to increment
3440 atomic_inc(&thresholds_new
->current_threshold
);
3445 rcu_assign_pointer(memcg
->thresholds
, thresholds_new
);
3447 rcu_assign_pointer(memcg
->memsw_thresholds
, thresholds_new
);
3449 /* To be sure that nobody uses thresholds before freeing it */
3454 mutex_unlock(&memcg
->thresholds_lock
);
3459 static int mem_cgroup_unregister_event(struct cgroup
*cgrp
, struct cftype
*cft
,
3460 struct eventfd_ctx
*eventfd
)
3462 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cgrp
);
3463 struct mem_cgroup_threshold_ary
*thresholds
, *thresholds_new
;
3464 int type
= MEMFILE_TYPE(cft
->private);
3469 mutex_lock(&memcg
->thresholds_lock
);
3471 thresholds
= memcg
->thresholds
;
3472 else if (type
== _MEMSWAP
)
3473 thresholds
= memcg
->memsw_thresholds
;
3478 * Something went wrong if we trying to unregister a threshold
3479 * if we don't have thresholds
3481 BUG_ON(!thresholds
);
3483 usage
= mem_cgroup_usage(memcg
, type
== _MEMSWAP
);
3485 /* Check if a threshold crossed before removing */
3486 __mem_cgroup_threshold(memcg
, type
== _MEMSWAP
);
3488 /* Calculate new number of threshold */
3489 for (i
= 0; i
< thresholds
->size
; i
++) {
3490 if (thresholds
->entries
[i
].eventfd
!= eventfd
)
3494 /* Set thresholds array to NULL if we don't have thresholds */
3496 thresholds_new
= NULL
;
3500 /* Allocate memory for new array of thresholds */
3501 thresholds_new
= kmalloc(sizeof(*thresholds_new
) +
3502 size
* sizeof(struct mem_cgroup_threshold
),
3504 if (!thresholds_new
) {
3508 thresholds_new
->size
= size
;
3510 /* Copy thresholds and find current threshold */
3511 atomic_set(&thresholds_new
->current_threshold
, -1);
3512 for (i
= 0, j
= 0; i
< thresholds
->size
; i
++) {
3513 if (thresholds
->entries
[i
].eventfd
== eventfd
)
3516 thresholds_new
->entries
[j
] = thresholds
->entries
[i
];
3517 if (thresholds_new
->entries
[j
].threshold
< usage
) {
3519 * thresholds_new->current_threshold will not be used
3520 * until rcu_assign_pointer(), so it's safe to increment
3523 atomic_inc(&thresholds_new
->current_threshold
);
3530 rcu_assign_pointer(memcg
->thresholds
, thresholds_new
);
3532 rcu_assign_pointer(memcg
->memsw_thresholds
, thresholds_new
);
3534 /* To be sure that nobody uses thresholds before freeing it */
3539 mutex_unlock(&memcg
->thresholds_lock
);
3544 static struct cftype mem_cgroup_files
[] = {
3546 .name
= "usage_in_bytes",
3547 .private = MEMFILE_PRIVATE(_MEM
, RES_USAGE
),
3548 .read_u64
= mem_cgroup_read
,
3549 .register_event
= mem_cgroup_register_event
,
3550 .unregister_event
= mem_cgroup_unregister_event
,
3553 .name
= "max_usage_in_bytes",
3554 .private = MEMFILE_PRIVATE(_MEM
, RES_MAX_USAGE
),
3555 .trigger
= mem_cgroup_reset
,
3556 .read_u64
= mem_cgroup_read
,
3559 .name
= "limit_in_bytes",
3560 .private = MEMFILE_PRIVATE(_MEM
, RES_LIMIT
),
3561 .write_string
= mem_cgroup_write
,
3562 .read_u64
= mem_cgroup_read
,
3565 .name
= "soft_limit_in_bytes",
3566 .private = MEMFILE_PRIVATE(_MEM
, RES_SOFT_LIMIT
),
3567 .write_string
= mem_cgroup_write
,
3568 .read_u64
= mem_cgroup_read
,
3572 .private = MEMFILE_PRIVATE(_MEM
, RES_FAILCNT
),
3573 .trigger
= mem_cgroup_reset
,
3574 .read_u64
= mem_cgroup_read
,
3578 .read_map
= mem_control_stat_show
,
3581 .name
= "force_empty",
3582 .trigger
= mem_cgroup_force_empty_write
,
3585 .name
= "use_hierarchy",
3586 .write_u64
= mem_cgroup_hierarchy_write
,
3587 .read_u64
= mem_cgroup_hierarchy_read
,
3590 .name
= "swappiness",
3591 .read_u64
= mem_cgroup_swappiness_read
,
3592 .write_u64
= mem_cgroup_swappiness_write
,
3595 .name
= "move_charge_at_immigrate",
3596 .read_u64
= mem_cgroup_move_charge_read
,
3597 .write_u64
= mem_cgroup_move_charge_write
,
3601 #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP
3602 static struct cftype memsw_cgroup_files
[] = {
3604 .name
= "memsw.usage_in_bytes",
3605 .private = MEMFILE_PRIVATE(_MEMSWAP
, RES_USAGE
),
3606 .read_u64
= mem_cgroup_read
,
3607 .register_event
= mem_cgroup_register_event
,
3608 .unregister_event
= mem_cgroup_unregister_event
,
3611 .name
= "memsw.max_usage_in_bytes",
3612 .private = MEMFILE_PRIVATE(_MEMSWAP
, RES_MAX_USAGE
),
3613 .trigger
= mem_cgroup_reset
,
3614 .read_u64
= mem_cgroup_read
,
3617 .name
= "memsw.limit_in_bytes",
3618 .private = MEMFILE_PRIVATE(_MEMSWAP
, RES_LIMIT
),
3619 .write_string
= mem_cgroup_write
,
3620 .read_u64
= mem_cgroup_read
,
3623 .name
= "memsw.failcnt",
3624 .private = MEMFILE_PRIVATE(_MEMSWAP
, RES_FAILCNT
),
3625 .trigger
= mem_cgroup_reset
,
3626 .read_u64
= mem_cgroup_read
,
3630 static int register_memsw_files(struct cgroup
*cont
, struct cgroup_subsys
*ss
)
3632 if (!do_swap_account
)
3634 return cgroup_add_files(cont
, ss
, memsw_cgroup_files
,
3635 ARRAY_SIZE(memsw_cgroup_files
));
3638 static int register_memsw_files(struct cgroup
*cont
, struct cgroup_subsys
*ss
)
3644 static int alloc_mem_cgroup_per_zone_info(struct mem_cgroup
*mem
, int node
)
3646 struct mem_cgroup_per_node
*pn
;
3647 struct mem_cgroup_per_zone
*mz
;
3649 int zone
, tmp
= node
;
3651 * This routine is called against possible nodes.
3652 * But it's BUG to call kmalloc() against offline node.
3654 * TODO: this routine can waste much memory for nodes which will
3655 * never be onlined. It's better to use memory hotplug callback
3658 if (!node_state(node
, N_NORMAL_MEMORY
))
3660 pn
= kmalloc_node(sizeof(*pn
), GFP_KERNEL
, tmp
);
3664 mem
->info
.nodeinfo
[node
] = pn
;
3665 memset(pn
, 0, sizeof(*pn
));
3667 for (zone
= 0; zone
< MAX_NR_ZONES
; zone
++) {
3668 mz
= &pn
->zoneinfo
[zone
];
3670 INIT_LIST_HEAD(&mz
->lists
[l
]);
3671 mz
->usage_in_excess
= 0;
3672 mz
->on_tree
= false;
3678 static void free_mem_cgroup_per_zone_info(struct mem_cgroup
*mem
, int node
)
3680 kfree(mem
->info
.nodeinfo
[node
]);
3683 static struct mem_cgroup
*mem_cgroup_alloc(void)
3685 struct mem_cgroup
*mem
;
3686 int size
= sizeof(struct mem_cgroup
);
3688 /* Can be very big if MAX_NUMNODES is very big */
3689 if (size
< PAGE_SIZE
)
3690 mem
= kmalloc(size
, GFP_KERNEL
);
3692 mem
= vmalloc(size
);
3697 memset(mem
, 0, size
);
3698 mem
->stat
= alloc_percpu(struct mem_cgroup_stat_cpu
);
3700 if (size
< PAGE_SIZE
)
3710 * At destroying mem_cgroup, references from swap_cgroup can remain.
3711 * (scanning all at force_empty is too costly...)
3713 * Instead of clearing all references at force_empty, we remember
3714 * the number of reference from swap_cgroup and free mem_cgroup when
3715 * it goes down to 0.
3717 * Removal of cgroup itself succeeds regardless of refs from swap.
3720 static void __mem_cgroup_free(struct mem_cgroup
*mem
)
3724 mem_cgroup_remove_from_trees(mem
);
3725 free_css_id(&mem_cgroup_subsys
, &mem
->css
);
3727 for_each_node_state(node
, N_POSSIBLE
)
3728 free_mem_cgroup_per_zone_info(mem
, node
);
3730 free_percpu(mem
->stat
);
3731 if (sizeof(struct mem_cgroup
) < PAGE_SIZE
)
3737 static void mem_cgroup_get(struct mem_cgroup
*mem
)
3739 atomic_inc(&mem
->refcnt
);
3742 static void __mem_cgroup_put(struct mem_cgroup
*mem
, int count
)
3744 if (atomic_sub_and_test(count
, &mem
->refcnt
)) {
3745 struct mem_cgroup
*parent
= parent_mem_cgroup(mem
);
3746 __mem_cgroup_free(mem
);
3748 mem_cgroup_put(parent
);
3752 static void mem_cgroup_put(struct mem_cgroup
*mem
)
3754 __mem_cgroup_put(mem
, 1);
3758 * Returns the parent mem_cgroup in memcgroup hierarchy with hierarchy enabled.
3760 static struct mem_cgroup
*parent_mem_cgroup(struct mem_cgroup
*mem
)
3762 if (!mem
->res
.parent
)
3764 return mem_cgroup_from_res_counter(mem
->res
.parent
, res
);
3767 #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP
3768 static void __init
enable_swap_cgroup(void)
3770 if (!mem_cgroup_disabled() && really_do_swap_account
)
3771 do_swap_account
= 1;
3774 static void __init
enable_swap_cgroup(void)
3779 static int mem_cgroup_soft_limit_tree_init(void)
3781 struct mem_cgroup_tree_per_node
*rtpn
;
3782 struct mem_cgroup_tree_per_zone
*rtpz
;
3783 int tmp
, node
, zone
;
3785 for_each_node_state(node
, N_POSSIBLE
) {
3787 if (!node_state(node
, N_NORMAL_MEMORY
))
3789 rtpn
= kzalloc_node(sizeof(*rtpn
), GFP_KERNEL
, tmp
);
3793 soft_limit_tree
.rb_tree_per_node
[node
] = rtpn
;
3795 for (zone
= 0; zone
< MAX_NR_ZONES
; zone
++) {
3796 rtpz
= &rtpn
->rb_tree_per_zone
[zone
];
3797 rtpz
->rb_root
= RB_ROOT
;
3798 spin_lock_init(&rtpz
->lock
);
3804 static struct cgroup_subsys_state
* __ref
3805 mem_cgroup_create(struct cgroup_subsys
*ss
, struct cgroup
*cont
)
3807 struct mem_cgroup
*mem
, *parent
;
3808 long error
= -ENOMEM
;
3811 mem
= mem_cgroup_alloc();
3813 return ERR_PTR(error
);
3815 for_each_node_state(node
, N_POSSIBLE
)
3816 if (alloc_mem_cgroup_per_zone_info(mem
, node
))
3820 if (cont
->parent
== NULL
) {
3822 enable_swap_cgroup();
3824 root_mem_cgroup
= mem
;
3825 if (mem_cgroup_soft_limit_tree_init())
3827 for_each_possible_cpu(cpu
) {
3828 struct memcg_stock_pcp
*stock
=
3829 &per_cpu(memcg_stock
, cpu
);
3830 INIT_WORK(&stock
->work
, drain_local_stock
);
3832 hotcpu_notifier(memcg_stock_cpu_callback
, 0);
3834 parent
= mem_cgroup_from_cont(cont
->parent
);
3835 mem
->use_hierarchy
= parent
->use_hierarchy
;
3838 if (parent
&& parent
->use_hierarchy
) {
3839 res_counter_init(&mem
->res
, &parent
->res
);
3840 res_counter_init(&mem
->memsw
, &parent
->memsw
);
3842 * We increment refcnt of the parent to ensure that we can
3843 * safely access it on res_counter_charge/uncharge.
3844 * This refcnt will be decremented when freeing this
3845 * mem_cgroup(see mem_cgroup_put).
3847 mem_cgroup_get(parent
);
3849 res_counter_init(&mem
->res
, NULL
);
3850 res_counter_init(&mem
->memsw
, NULL
);
3852 mem
->last_scanned_child
= 0;
3853 spin_lock_init(&mem
->reclaim_param_lock
);
3856 mem
->swappiness
= get_swappiness(parent
);
3857 atomic_set(&mem
->refcnt
, 1);
3858 mem
->move_charge_at_immigrate
= 0;
3859 mutex_init(&mem
->thresholds_lock
);
3862 __mem_cgroup_free(mem
);
3863 root_mem_cgroup
= NULL
;
3864 return ERR_PTR(error
);
3867 static int mem_cgroup_pre_destroy(struct cgroup_subsys
*ss
,
3868 struct cgroup
*cont
)
3870 struct mem_cgroup
*mem
= mem_cgroup_from_cont(cont
);
3872 return mem_cgroup_force_empty(mem
, false);
3875 static void mem_cgroup_destroy(struct cgroup_subsys
*ss
,
3876 struct cgroup
*cont
)
3878 struct mem_cgroup
*mem
= mem_cgroup_from_cont(cont
);
3880 mem_cgroup_put(mem
);
3883 static int mem_cgroup_populate(struct cgroup_subsys
*ss
,
3884 struct cgroup
*cont
)
3888 ret
= cgroup_add_files(cont
, ss
, mem_cgroup_files
,
3889 ARRAY_SIZE(mem_cgroup_files
));
3892 ret
= register_memsw_files(cont
, ss
);
3897 /* Handlers for move charge at task migration. */
3898 #define PRECHARGE_COUNT_AT_ONCE 256
3899 static int mem_cgroup_do_precharge(unsigned long count
)
3902 int batch_count
= PRECHARGE_COUNT_AT_ONCE
;
3903 struct mem_cgroup
*mem
= mc
.to
;
3905 if (mem_cgroup_is_root(mem
)) {
3906 mc
.precharge
+= count
;
3907 /* we don't need css_get for root */
3910 /* try to charge at once */
3912 struct res_counter
*dummy
;
3914 * "mem" cannot be under rmdir() because we've already checked
3915 * by cgroup_lock_live_cgroup() that it is not removed and we
3916 * are still under the same cgroup_mutex. So we can postpone
3919 if (res_counter_charge(&mem
->res
, PAGE_SIZE
* count
, &dummy
))
3921 if (do_swap_account
&& res_counter_charge(&mem
->memsw
,
3922 PAGE_SIZE
* count
, &dummy
)) {
3923 res_counter_uncharge(&mem
->res
, PAGE_SIZE
* count
);
3926 mc
.precharge
+= count
;
3927 VM_BUG_ON(test_bit(CSS_ROOT
, &mem
->css
.flags
));
3928 WARN_ON_ONCE(count
> INT_MAX
);
3929 __css_get(&mem
->css
, (int)count
);
3933 /* fall back to one by one charge */
3935 if (signal_pending(current
)) {
3939 if (!batch_count
--) {
3940 batch_count
= PRECHARGE_COUNT_AT_ONCE
;
3943 ret
= __mem_cgroup_try_charge(NULL
, GFP_KERNEL
, &mem
, false);
3945 /* mem_cgroup_clear_mc() will do uncharge later */
3953 * is_target_pte_for_mc - check a pte whether it is valid for move charge
3954 * @vma: the vma the pte to be checked belongs
3955 * @addr: the address corresponding to the pte to be checked
3956 * @ptent: the pte to be checked
3957 * @target: the pointer the target page or swap ent will be stored(can be NULL)
3960 * 0(MC_TARGET_NONE): if the pte is not a target for move charge.
3961 * 1(MC_TARGET_PAGE): if the page corresponding to this pte is a target for
3962 * move charge. if @target is not NULL, the page is stored in target->page
3963 * with extra refcnt got(Callers should handle it).
3964 * 2(MC_TARGET_SWAP): if the swap entry corresponding to this pte is a
3965 * target for charge migration. if @target is not NULL, the entry is stored
3968 * Called with pte lock held.
3975 enum mc_target_type
{
3976 MC_TARGET_NONE
, /* not used */
3981 static int is_target_pte_for_mc(struct vm_area_struct
*vma
,
3982 unsigned long addr
, pte_t ptent
, union mc_target
*target
)
3984 struct page
*page
= NULL
;
3985 struct page_cgroup
*pc
;
3987 swp_entry_t ent
= { .val
= 0 };
3988 int usage_count
= 0;
3989 bool move_anon
= test_bit(MOVE_CHARGE_TYPE_ANON
,
3990 &mc
.to
->move_charge_at_immigrate
);
3992 if (!pte_present(ptent
)) {
3993 /* TODO: handle swap of shmes/tmpfs */
3994 if (pte_none(ptent
) || pte_file(ptent
))
3996 else if (is_swap_pte(ptent
)) {
3997 ent
= pte_to_swp_entry(ptent
);
3998 if (!move_anon
|| non_swap_entry(ent
))
4000 usage_count
= mem_cgroup_count_swap_user(ent
, &page
);
4003 page
= vm_normal_page(vma
, addr
, ptent
);
4004 if (!page
|| !page_mapped(page
))
4007 * TODO: We don't move charges of file(including shmem/tmpfs)
4010 if (!move_anon
|| !PageAnon(page
))
4012 if (!get_page_unless_zero(page
))
4014 usage_count
= page_mapcount(page
);
4016 if (usage_count
> 1) {
4018 * TODO: We don't move charges of shared(used by multiple
4019 * processes) pages for now.
4026 pc
= lookup_page_cgroup(page
);
4028 * Do only loose check w/o page_cgroup lock.
4029 * mem_cgroup_move_account() checks the pc is valid or not under
4032 if (PageCgroupUsed(pc
) && pc
->mem_cgroup
== mc
.from
) {
4033 ret
= MC_TARGET_PAGE
;
4035 target
->page
= page
;
4037 if (!ret
|| !target
)
4041 if (ent
.val
&& do_swap_account
&& !ret
&&
4042 css_id(&mc
.from
->css
) == lookup_swap_cgroup(ent
)) {
4043 ret
= MC_TARGET_SWAP
;
4050 static int mem_cgroup_count_precharge_pte_range(pmd_t
*pmd
,
4051 unsigned long addr
, unsigned long end
,
4052 struct mm_walk
*walk
)
4054 struct vm_area_struct
*vma
= walk
->private;
4058 pte
= pte_offset_map_lock(vma
->vm_mm
, pmd
, addr
, &ptl
);
4059 for (; addr
!= end
; pte
++, addr
+= PAGE_SIZE
)
4060 if (is_target_pte_for_mc(vma
, addr
, *pte
, NULL
))
4061 mc
.precharge
++; /* increment precharge temporarily */
4062 pte_unmap_unlock(pte
- 1, ptl
);
4068 static unsigned long mem_cgroup_count_precharge(struct mm_struct
*mm
)
4070 unsigned long precharge
;
4071 struct vm_area_struct
*vma
;
4073 down_read(&mm
->mmap_sem
);
4074 for (vma
= mm
->mmap
; vma
; vma
= vma
->vm_next
) {
4075 struct mm_walk mem_cgroup_count_precharge_walk
= {
4076 .pmd_entry
= mem_cgroup_count_precharge_pte_range
,
4080 if (is_vm_hugetlb_page(vma
))
4082 /* TODO: We don't move charges of shmem/tmpfs pages for now. */
4083 if (vma
->vm_flags
& VM_SHARED
)
4085 walk_page_range(vma
->vm_start
, vma
->vm_end
,
4086 &mem_cgroup_count_precharge_walk
);
4088 up_read(&mm
->mmap_sem
);
4090 precharge
= mc
.precharge
;
4096 static int mem_cgroup_precharge_mc(struct mm_struct
*mm
)
4098 return mem_cgroup_do_precharge(mem_cgroup_count_precharge(mm
));
4101 static void mem_cgroup_clear_mc(void)
4103 /* we must uncharge all the leftover precharges from mc.to */
4105 __mem_cgroup_cancel_charge(mc
.to
, mc
.precharge
);
4109 * we didn't uncharge from mc.from at mem_cgroup_move_account(), so
4110 * we must uncharge here.
4112 if (mc
.moved_charge
) {
4113 __mem_cgroup_cancel_charge(mc
.from
, mc
.moved_charge
);
4114 mc
.moved_charge
= 0;
4116 /* we must fixup refcnts and charges */
4117 if (mc
.moved_swap
) {
4118 WARN_ON_ONCE(mc
.moved_swap
> INT_MAX
);
4119 /* uncharge swap account from the old cgroup */
4120 if (!mem_cgroup_is_root(mc
.from
))
4121 res_counter_uncharge(&mc
.from
->memsw
,
4122 PAGE_SIZE
* mc
.moved_swap
);
4123 __mem_cgroup_put(mc
.from
, mc
.moved_swap
);
4125 if (!mem_cgroup_is_root(mc
.to
)) {
4127 * we charged both to->res and to->memsw, so we should
4130 res_counter_uncharge(&mc
.to
->res
,
4131 PAGE_SIZE
* mc
.moved_swap
);
4132 VM_BUG_ON(test_bit(CSS_ROOT
, &mc
.to
->css
.flags
));
4133 __css_put(&mc
.to
->css
, mc
.moved_swap
);
4135 /* we've already done mem_cgroup_get(mc.to) */
4141 mc
.moving_task
= NULL
;
4142 wake_up_all(&mc
.waitq
);
4145 static int mem_cgroup_can_attach(struct cgroup_subsys
*ss
,
4146 struct cgroup
*cgroup
,
4147 struct task_struct
*p
,
4151 struct mem_cgroup
*mem
= mem_cgroup_from_cont(cgroup
);
4153 if (mem
->move_charge_at_immigrate
) {
4154 struct mm_struct
*mm
;
4155 struct mem_cgroup
*from
= mem_cgroup_from_task(p
);
4157 VM_BUG_ON(from
== mem
);
4159 mm
= get_task_mm(p
);
4162 /* We move charges only when we move a owner of the mm */
4163 if (mm
->owner
== p
) {
4166 VM_BUG_ON(mc
.precharge
);
4167 VM_BUG_ON(mc
.moved_charge
);
4168 VM_BUG_ON(mc
.moved_swap
);
4169 VM_BUG_ON(mc
.moving_task
);
4173 mc
.moved_charge
= 0;
4175 mc
.moving_task
= current
;
4177 ret
= mem_cgroup_precharge_mc(mm
);
4179 mem_cgroup_clear_mc();
4186 static void mem_cgroup_cancel_attach(struct cgroup_subsys
*ss
,
4187 struct cgroup
*cgroup
,
4188 struct task_struct
*p
,
4191 mem_cgroup_clear_mc();
4194 static int mem_cgroup_move_charge_pte_range(pmd_t
*pmd
,
4195 unsigned long addr
, unsigned long end
,
4196 struct mm_walk
*walk
)
4199 struct vm_area_struct
*vma
= walk
->private;
4204 pte
= pte_offset_map_lock(vma
->vm_mm
, pmd
, addr
, &ptl
);
4205 for (; addr
!= end
; addr
+= PAGE_SIZE
) {
4206 pte_t ptent
= *(pte
++);
4207 union mc_target target
;
4210 struct page_cgroup
*pc
;
4216 type
= is_target_pte_for_mc(vma
, addr
, ptent
, &target
);
4218 case MC_TARGET_PAGE
:
4220 if (isolate_lru_page(page
))
4222 pc
= lookup_page_cgroup(page
);
4223 if (!mem_cgroup_move_account(pc
,
4224 mc
.from
, mc
.to
, false)) {
4226 /* we uncharge from mc.from later. */
4229 putback_lru_page(page
);
4230 put
: /* is_target_pte_for_mc() gets the page */
4233 case MC_TARGET_SWAP
:
4235 if (!mem_cgroup_move_swap_account(ent
,
4236 mc
.from
, mc
.to
, false)) {
4238 /* we fixup refcnts and charges later. */
4246 pte_unmap_unlock(pte
- 1, ptl
);
4251 * We have consumed all precharges we got in can_attach().
4252 * We try charge one by one, but don't do any additional
4253 * charges to mc.to if we have failed in charge once in attach()
4256 ret
= mem_cgroup_do_precharge(1);
4264 static void mem_cgroup_move_charge(struct mm_struct
*mm
)
4266 struct vm_area_struct
*vma
;
4268 lru_add_drain_all();
4269 down_read(&mm
->mmap_sem
);
4270 for (vma
= mm
->mmap
; vma
; vma
= vma
->vm_next
) {
4272 struct mm_walk mem_cgroup_move_charge_walk
= {
4273 .pmd_entry
= mem_cgroup_move_charge_pte_range
,
4277 if (is_vm_hugetlb_page(vma
))
4279 /* TODO: We don't move charges of shmem/tmpfs pages for now. */
4280 if (vma
->vm_flags
& VM_SHARED
)
4282 ret
= walk_page_range(vma
->vm_start
, vma
->vm_end
,
4283 &mem_cgroup_move_charge_walk
);
4286 * means we have consumed all precharges and failed in
4287 * doing additional charge. Just abandon here.
4291 up_read(&mm
->mmap_sem
);
4294 static void mem_cgroup_move_task(struct cgroup_subsys
*ss
,
4295 struct cgroup
*cont
,
4296 struct cgroup
*old_cont
,
4297 struct task_struct
*p
,
4300 struct mm_struct
*mm
;
4303 /* no need to move charge */
4306 mm
= get_task_mm(p
);
4308 mem_cgroup_move_charge(mm
);
4311 mem_cgroup_clear_mc();
4313 #else /* !CONFIG_MMU */
4314 static int mem_cgroup_can_attach(struct cgroup_subsys
*ss
,
4315 struct cgroup
*cgroup
,
4316 struct task_struct
*p
,
4321 static void mem_cgroup_cancel_attach(struct cgroup_subsys
*ss
,
4322 struct cgroup
*cgroup
,
4323 struct task_struct
*p
,
4327 static void mem_cgroup_move_task(struct cgroup_subsys
*ss
,
4328 struct cgroup
*cont
,
4329 struct cgroup
*old_cont
,
4330 struct task_struct
*p
,
4336 struct cgroup_subsys mem_cgroup_subsys
= {
4338 .subsys_id
= mem_cgroup_subsys_id
,
4339 .create
= mem_cgroup_create
,
4340 .pre_destroy
= mem_cgroup_pre_destroy
,
4341 .destroy
= mem_cgroup_destroy
,
4342 .populate
= mem_cgroup_populate
,
4343 .can_attach
= mem_cgroup_can_attach
,
4344 .cancel_attach
= mem_cgroup_cancel_attach
,
4345 .attach
= mem_cgroup_move_task
,
4350 #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP
4352 static int __init
disable_swap_account(char *s
)
4354 really_do_swap_account
= 0;
4357 __setup("noswapaccount", disable_swap_account
);