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
;
153 struct mem_cgroup_threshold_ary
{
154 /* An array index points to threshold just below usage. */
155 atomic_t current_threshold
;
156 /* Size of entries[] */
158 /* Array of thresholds */
159 struct mem_cgroup_threshold entries
[0];
162 struct mem_cgroup_eventfd_list
{
163 struct list_head list
;
164 struct eventfd_ctx
*eventfd
;
167 static void mem_cgroup_threshold(struct mem_cgroup
*mem
);
168 static void mem_cgroup_oom_notify(struct mem_cgroup
*mem
);
171 * The memory controller data structure. The memory controller controls both
172 * page cache and RSS per cgroup. We would eventually like to provide
173 * statistics based on the statistics developed by Rik Van Riel for clock-pro,
174 * to help the administrator determine what knobs to tune.
176 * TODO: Add a water mark for the memory controller. Reclaim will begin when
177 * we hit the water mark. May be even add a low water mark, such that
178 * no reclaim occurs from a cgroup at it's low water mark, this is
179 * a feature that will be implemented much later in the future.
182 struct cgroup_subsys_state css
;
184 * the counter to account for memory usage
186 struct res_counter res
;
188 * the counter to account for mem+swap usage.
190 struct res_counter memsw
;
192 * Per cgroup active and inactive list, similar to the
193 * per zone LRU lists.
195 struct mem_cgroup_lru_info info
;
198 protect against reclaim related member.
200 spinlock_t reclaim_param_lock
;
202 int prev_priority
; /* for recording reclaim priority */
205 * While reclaiming in a hierarchy, we cache the last child we
208 int last_scanned_child
;
210 * Should the accounting and control be hierarchical, per subtree?
216 unsigned int swappiness
;
217 /* OOM-Killer disable */
218 int oom_kill_disable
;
220 /* set when res.limit == memsw.limit */
221 bool memsw_is_minimum
;
223 /* protect arrays of thresholds */
224 struct mutex thresholds_lock
;
226 /* thresholds for memory usage. RCU-protected */
227 struct mem_cgroup_threshold_ary
*thresholds
;
229 /* thresholds for mem+swap usage. RCU-protected */
230 struct mem_cgroup_threshold_ary
*memsw_thresholds
;
232 /* For oom notifier event fd */
233 struct list_head oom_notify
;
236 * Should we move charges of a task when a task is moved into this
237 * mem_cgroup ? And what type of charges should we move ?
239 unsigned long move_charge_at_immigrate
;
243 struct mem_cgroup_stat_cpu
*stat
;
246 /* Stuffs for move charges at task migration. */
248 * Types of charges to be moved. "move_charge_at_immitgrate" is treated as a
249 * left-shifted bitmap of these types.
252 MOVE_CHARGE_TYPE_ANON
, /* private anonymous page and swap of it */
256 /* "mc" and its members are protected by cgroup_mutex */
257 static struct move_charge_struct
{
258 struct mem_cgroup
*from
;
259 struct mem_cgroup
*to
;
260 unsigned long precharge
;
261 unsigned long moved_charge
;
262 unsigned long moved_swap
;
263 struct task_struct
*moving_task
; /* a task moving charges */
264 wait_queue_head_t waitq
; /* a waitq for other context */
266 .waitq
= __WAIT_QUEUE_HEAD_INITIALIZER(mc
.waitq
),
270 * Maximum loops in mem_cgroup_hierarchical_reclaim(), used for soft
271 * limit reclaim to prevent infinite loops, if they ever occur.
273 #define MEM_CGROUP_MAX_RECLAIM_LOOPS (100)
274 #define MEM_CGROUP_MAX_SOFT_LIMIT_RECLAIM_LOOPS (2)
277 MEM_CGROUP_CHARGE_TYPE_CACHE
= 0,
278 MEM_CGROUP_CHARGE_TYPE_MAPPED
,
279 MEM_CGROUP_CHARGE_TYPE_SHMEM
, /* used by page migration of shmem */
280 MEM_CGROUP_CHARGE_TYPE_FORCE
, /* used by force_empty */
281 MEM_CGROUP_CHARGE_TYPE_SWAPOUT
, /* for accounting swapcache */
282 MEM_CGROUP_CHARGE_TYPE_DROP
, /* a page was unused swap cache */
286 /* only for here (for easy reading.) */
287 #define PCGF_CACHE (1UL << PCG_CACHE)
288 #define PCGF_USED (1UL << PCG_USED)
289 #define PCGF_LOCK (1UL << PCG_LOCK)
290 /* Not used, but added here for completeness */
291 #define PCGF_ACCT (1UL << PCG_ACCT)
293 /* for encoding cft->private value on file */
296 #define _OOM_TYPE (2)
297 #define MEMFILE_PRIVATE(x, val) (((x) << 16) | (val))
298 #define MEMFILE_TYPE(val) (((val) >> 16) & 0xffff)
299 #define MEMFILE_ATTR(val) ((val) & 0xffff)
300 /* Used for OOM nofiier */
301 #define OOM_CONTROL (0)
304 * Reclaim flags for mem_cgroup_hierarchical_reclaim
306 #define MEM_CGROUP_RECLAIM_NOSWAP_BIT 0x0
307 #define MEM_CGROUP_RECLAIM_NOSWAP (1 << MEM_CGROUP_RECLAIM_NOSWAP_BIT)
308 #define MEM_CGROUP_RECLAIM_SHRINK_BIT 0x1
309 #define MEM_CGROUP_RECLAIM_SHRINK (1 << MEM_CGROUP_RECLAIM_SHRINK_BIT)
310 #define MEM_CGROUP_RECLAIM_SOFT_BIT 0x2
311 #define MEM_CGROUP_RECLAIM_SOFT (1 << MEM_CGROUP_RECLAIM_SOFT_BIT)
313 static void mem_cgroup_get(struct mem_cgroup
*mem
);
314 static void mem_cgroup_put(struct mem_cgroup
*mem
);
315 static struct mem_cgroup
*parent_mem_cgroup(struct mem_cgroup
*mem
);
316 static void drain_all_stock_async(void);
318 static struct mem_cgroup_per_zone
*
319 mem_cgroup_zoneinfo(struct mem_cgroup
*mem
, int nid
, int zid
)
321 return &mem
->info
.nodeinfo
[nid
]->zoneinfo
[zid
];
324 struct cgroup_subsys_state
*mem_cgroup_css(struct mem_cgroup
*mem
)
329 static struct mem_cgroup_per_zone
*
330 page_cgroup_zoneinfo(struct page_cgroup
*pc
)
332 struct mem_cgroup
*mem
= pc
->mem_cgroup
;
333 int nid
= page_cgroup_nid(pc
);
334 int zid
= page_cgroup_zid(pc
);
339 return mem_cgroup_zoneinfo(mem
, nid
, zid
);
342 static struct mem_cgroup_tree_per_zone
*
343 soft_limit_tree_node_zone(int nid
, int zid
)
345 return &soft_limit_tree
.rb_tree_per_node
[nid
]->rb_tree_per_zone
[zid
];
348 static struct mem_cgroup_tree_per_zone
*
349 soft_limit_tree_from_page(struct page
*page
)
351 int nid
= page_to_nid(page
);
352 int zid
= page_zonenum(page
);
354 return &soft_limit_tree
.rb_tree_per_node
[nid
]->rb_tree_per_zone
[zid
];
358 __mem_cgroup_insert_exceeded(struct mem_cgroup
*mem
,
359 struct mem_cgroup_per_zone
*mz
,
360 struct mem_cgroup_tree_per_zone
*mctz
,
361 unsigned long long new_usage_in_excess
)
363 struct rb_node
**p
= &mctz
->rb_root
.rb_node
;
364 struct rb_node
*parent
= NULL
;
365 struct mem_cgroup_per_zone
*mz_node
;
370 mz
->usage_in_excess
= new_usage_in_excess
;
371 if (!mz
->usage_in_excess
)
375 mz_node
= rb_entry(parent
, struct mem_cgroup_per_zone
,
377 if (mz
->usage_in_excess
< mz_node
->usage_in_excess
)
380 * We can't avoid mem cgroups that are over their soft
381 * limit by the same amount
383 else if (mz
->usage_in_excess
>= mz_node
->usage_in_excess
)
386 rb_link_node(&mz
->tree_node
, parent
, p
);
387 rb_insert_color(&mz
->tree_node
, &mctz
->rb_root
);
392 __mem_cgroup_remove_exceeded(struct mem_cgroup
*mem
,
393 struct mem_cgroup_per_zone
*mz
,
394 struct mem_cgroup_tree_per_zone
*mctz
)
398 rb_erase(&mz
->tree_node
, &mctz
->rb_root
);
403 mem_cgroup_remove_exceeded(struct mem_cgroup
*mem
,
404 struct mem_cgroup_per_zone
*mz
,
405 struct mem_cgroup_tree_per_zone
*mctz
)
407 spin_lock(&mctz
->lock
);
408 __mem_cgroup_remove_exceeded(mem
, mz
, mctz
);
409 spin_unlock(&mctz
->lock
);
413 static void mem_cgroup_update_tree(struct mem_cgroup
*mem
, struct page
*page
)
415 unsigned long long excess
;
416 struct mem_cgroup_per_zone
*mz
;
417 struct mem_cgroup_tree_per_zone
*mctz
;
418 int nid
= page_to_nid(page
);
419 int zid
= page_zonenum(page
);
420 mctz
= soft_limit_tree_from_page(page
);
423 * Necessary to update all ancestors when hierarchy is used.
424 * because their event counter is not touched.
426 for (; mem
; mem
= parent_mem_cgroup(mem
)) {
427 mz
= mem_cgroup_zoneinfo(mem
, nid
, zid
);
428 excess
= res_counter_soft_limit_excess(&mem
->res
);
430 * We have to update the tree if mz is on RB-tree or
431 * mem is over its softlimit.
433 if (excess
|| mz
->on_tree
) {
434 spin_lock(&mctz
->lock
);
435 /* if on-tree, remove it */
437 __mem_cgroup_remove_exceeded(mem
, mz
, mctz
);
439 * Insert again. mz->usage_in_excess will be updated.
440 * If excess is 0, no tree ops.
442 __mem_cgroup_insert_exceeded(mem
, mz
, mctz
, excess
);
443 spin_unlock(&mctz
->lock
);
448 static void mem_cgroup_remove_from_trees(struct mem_cgroup
*mem
)
451 struct mem_cgroup_per_zone
*mz
;
452 struct mem_cgroup_tree_per_zone
*mctz
;
454 for_each_node_state(node
, N_POSSIBLE
) {
455 for (zone
= 0; zone
< MAX_NR_ZONES
; zone
++) {
456 mz
= mem_cgroup_zoneinfo(mem
, node
, zone
);
457 mctz
= soft_limit_tree_node_zone(node
, zone
);
458 mem_cgroup_remove_exceeded(mem
, mz
, mctz
);
463 static inline unsigned long mem_cgroup_get_excess(struct mem_cgroup
*mem
)
465 return res_counter_soft_limit_excess(&mem
->res
) >> PAGE_SHIFT
;
468 static struct mem_cgroup_per_zone
*
469 __mem_cgroup_largest_soft_limit_node(struct mem_cgroup_tree_per_zone
*mctz
)
471 struct rb_node
*rightmost
= NULL
;
472 struct mem_cgroup_per_zone
*mz
;
476 rightmost
= rb_last(&mctz
->rb_root
);
478 goto done
; /* Nothing to reclaim from */
480 mz
= rb_entry(rightmost
, struct mem_cgroup_per_zone
, tree_node
);
482 * Remove the node now but someone else can add it back,
483 * we will to add it back at the end of reclaim to its correct
484 * position in the tree.
486 __mem_cgroup_remove_exceeded(mz
->mem
, mz
, mctz
);
487 if (!res_counter_soft_limit_excess(&mz
->mem
->res
) ||
488 !css_tryget(&mz
->mem
->css
))
494 static struct mem_cgroup_per_zone
*
495 mem_cgroup_largest_soft_limit_node(struct mem_cgroup_tree_per_zone
*mctz
)
497 struct mem_cgroup_per_zone
*mz
;
499 spin_lock(&mctz
->lock
);
500 mz
= __mem_cgroup_largest_soft_limit_node(mctz
);
501 spin_unlock(&mctz
->lock
);
505 static s64
mem_cgroup_read_stat(struct mem_cgroup
*mem
,
506 enum mem_cgroup_stat_index idx
)
511 for_each_possible_cpu(cpu
)
512 val
+= per_cpu(mem
->stat
->count
[idx
], cpu
);
516 static s64
mem_cgroup_local_usage(struct mem_cgroup
*mem
)
520 ret
= mem_cgroup_read_stat(mem
, MEM_CGROUP_STAT_RSS
);
521 ret
+= mem_cgroup_read_stat(mem
, MEM_CGROUP_STAT_CACHE
);
525 static void mem_cgroup_swap_statistics(struct mem_cgroup
*mem
,
528 int val
= (charge
) ? 1 : -1;
529 this_cpu_add(mem
->stat
->count
[MEM_CGROUP_STAT_SWAPOUT
], val
);
532 static void mem_cgroup_charge_statistics(struct mem_cgroup
*mem
,
533 struct page_cgroup
*pc
,
536 int val
= (charge
) ? 1 : -1;
540 if (PageCgroupCache(pc
))
541 __this_cpu_add(mem
->stat
->count
[MEM_CGROUP_STAT_CACHE
], val
);
543 __this_cpu_add(mem
->stat
->count
[MEM_CGROUP_STAT_RSS
], val
);
546 __this_cpu_inc(mem
->stat
->count
[MEM_CGROUP_STAT_PGPGIN_COUNT
]);
548 __this_cpu_inc(mem
->stat
->count
[MEM_CGROUP_STAT_PGPGOUT_COUNT
]);
549 __this_cpu_inc(mem
->stat
->count
[MEM_CGROUP_EVENTS
]);
554 static unsigned long mem_cgroup_get_local_zonestat(struct mem_cgroup
*mem
,
558 struct mem_cgroup_per_zone
*mz
;
561 for_each_online_node(nid
)
562 for (zid
= 0; zid
< MAX_NR_ZONES
; zid
++) {
563 mz
= mem_cgroup_zoneinfo(mem
, nid
, zid
);
564 total
+= MEM_CGROUP_ZSTAT(mz
, idx
);
569 static bool __memcg_event_check(struct mem_cgroup
*mem
, int event_mask_shift
)
573 val
= this_cpu_read(mem
->stat
->count
[MEM_CGROUP_EVENTS
]);
575 return !(val
& ((1 << event_mask_shift
) - 1));
579 * Check events in order.
582 static void memcg_check_events(struct mem_cgroup
*mem
, struct page
*page
)
584 /* threshold event is triggered in finer grain than soft limit */
585 if (unlikely(__memcg_event_check(mem
, THRESHOLDS_EVENTS_THRESH
))) {
586 mem_cgroup_threshold(mem
);
587 if (unlikely(__memcg_event_check(mem
, SOFTLIMIT_EVENTS_THRESH
)))
588 mem_cgroup_update_tree(mem
, page
);
592 static struct mem_cgroup
*mem_cgroup_from_cont(struct cgroup
*cont
)
594 return container_of(cgroup_subsys_state(cont
,
595 mem_cgroup_subsys_id
), struct mem_cgroup
,
599 struct mem_cgroup
*mem_cgroup_from_task(struct task_struct
*p
)
602 * mm_update_next_owner() may clear mm->owner to NULL
603 * if it races with swapoff, page migration, etc.
604 * So this can be called with p == NULL.
609 return container_of(task_subsys_state(p
, mem_cgroup_subsys_id
),
610 struct mem_cgroup
, css
);
613 static struct mem_cgroup
*try_get_mem_cgroup_from_mm(struct mm_struct
*mm
)
615 struct mem_cgroup
*mem
= NULL
;
620 * Because we have no locks, mm->owner's may be being moved to other
621 * cgroup. We use css_tryget() here even if this looks
622 * pessimistic (rather than adding locks here).
626 mem
= mem_cgroup_from_task(rcu_dereference(mm
->owner
));
629 } while (!css_tryget(&mem
->css
));
635 * Call callback function against all cgroup under hierarchy tree.
637 static int mem_cgroup_walk_tree(struct mem_cgroup
*root
, void *data
,
638 int (*func
)(struct mem_cgroup
*, void *))
640 int found
, ret
, nextid
;
641 struct cgroup_subsys_state
*css
;
642 struct mem_cgroup
*mem
;
644 if (!root
->use_hierarchy
)
645 return (*func
)(root
, data
);
653 css
= css_get_next(&mem_cgroup_subsys
, nextid
, &root
->css
,
655 if (css
&& css_tryget(css
))
656 mem
= container_of(css
, struct mem_cgroup
, css
);
660 ret
= (*func
)(mem
, data
);
664 } while (!ret
&& css
);
669 static inline bool mem_cgroup_is_root(struct mem_cgroup
*mem
)
671 return (mem
== root_mem_cgroup
);
675 * Following LRU functions are allowed to be used without PCG_LOCK.
676 * Operations are called by routine of global LRU independently from memcg.
677 * What we have to take care of here is validness of pc->mem_cgroup.
679 * Changes to pc->mem_cgroup happens when
682 * In typical case, "charge" is done before add-to-lru. Exception is SwapCache.
683 * It is added to LRU before charge.
684 * If PCG_USED bit is not set, page_cgroup is not added to this private LRU.
685 * When moving account, the page is not on LRU. It's isolated.
688 void mem_cgroup_del_lru_list(struct page
*page
, enum lru_list lru
)
690 struct page_cgroup
*pc
;
691 struct mem_cgroup_per_zone
*mz
;
693 if (mem_cgroup_disabled())
695 pc
= lookup_page_cgroup(page
);
696 /* can happen while we handle swapcache. */
697 if (!TestClearPageCgroupAcctLRU(pc
))
699 VM_BUG_ON(!pc
->mem_cgroup
);
701 * We don't check PCG_USED bit. It's cleared when the "page" is finally
702 * removed from global LRU.
704 mz
= page_cgroup_zoneinfo(pc
);
705 MEM_CGROUP_ZSTAT(mz
, lru
) -= 1;
706 if (mem_cgroup_is_root(pc
->mem_cgroup
))
708 VM_BUG_ON(list_empty(&pc
->lru
));
709 list_del_init(&pc
->lru
);
713 void mem_cgroup_del_lru(struct page
*page
)
715 mem_cgroup_del_lru_list(page
, page_lru(page
));
718 void mem_cgroup_rotate_lru_list(struct page
*page
, enum lru_list lru
)
720 struct mem_cgroup_per_zone
*mz
;
721 struct page_cgroup
*pc
;
723 if (mem_cgroup_disabled())
726 pc
= lookup_page_cgroup(page
);
728 * Used bit is set without atomic ops but after smp_wmb().
729 * For making pc->mem_cgroup visible, insert smp_rmb() here.
732 /* unused or root page is not rotated. */
733 if (!PageCgroupUsed(pc
) || mem_cgroup_is_root(pc
->mem_cgroup
))
735 mz
= page_cgroup_zoneinfo(pc
);
736 list_move(&pc
->lru
, &mz
->lists
[lru
]);
739 void mem_cgroup_add_lru_list(struct page
*page
, enum lru_list lru
)
741 struct page_cgroup
*pc
;
742 struct mem_cgroup_per_zone
*mz
;
744 if (mem_cgroup_disabled())
746 pc
= lookup_page_cgroup(page
);
747 VM_BUG_ON(PageCgroupAcctLRU(pc
));
749 * Used bit is set without atomic ops but after smp_wmb().
750 * For making pc->mem_cgroup visible, insert smp_rmb() here.
753 if (!PageCgroupUsed(pc
))
756 mz
= page_cgroup_zoneinfo(pc
);
757 MEM_CGROUP_ZSTAT(mz
, lru
) += 1;
758 SetPageCgroupAcctLRU(pc
);
759 if (mem_cgroup_is_root(pc
->mem_cgroup
))
761 list_add(&pc
->lru
, &mz
->lists
[lru
]);
765 * At handling SwapCache, pc->mem_cgroup may be changed while it's linked to
766 * lru because the page may.be reused after it's fully uncharged (because of
767 * SwapCache behavior).To handle that, unlink page_cgroup from LRU when charge
768 * it again. This function is only used to charge SwapCache. It's done under
769 * lock_page and expected that zone->lru_lock is never held.
771 static void mem_cgroup_lru_del_before_commit_swapcache(struct page
*page
)
774 struct zone
*zone
= page_zone(page
);
775 struct page_cgroup
*pc
= lookup_page_cgroup(page
);
777 spin_lock_irqsave(&zone
->lru_lock
, flags
);
779 * Forget old LRU when this page_cgroup is *not* used. This Used bit
780 * is guarded by lock_page() because the page is SwapCache.
782 if (!PageCgroupUsed(pc
))
783 mem_cgroup_del_lru_list(page
, page_lru(page
));
784 spin_unlock_irqrestore(&zone
->lru_lock
, flags
);
787 static void mem_cgroup_lru_add_after_commit_swapcache(struct page
*page
)
790 struct zone
*zone
= page_zone(page
);
791 struct page_cgroup
*pc
= lookup_page_cgroup(page
);
793 spin_lock_irqsave(&zone
->lru_lock
, flags
);
794 /* link when the page is linked to LRU but page_cgroup isn't */
795 if (PageLRU(page
) && !PageCgroupAcctLRU(pc
))
796 mem_cgroup_add_lru_list(page
, page_lru(page
));
797 spin_unlock_irqrestore(&zone
->lru_lock
, flags
);
801 void mem_cgroup_move_lists(struct page
*page
,
802 enum lru_list from
, enum lru_list to
)
804 if (mem_cgroup_disabled())
806 mem_cgroup_del_lru_list(page
, from
);
807 mem_cgroup_add_lru_list(page
, to
);
810 int task_in_mem_cgroup(struct task_struct
*task
, const struct mem_cgroup
*mem
)
813 struct mem_cgroup
*curr
= NULL
;
817 curr
= try_get_mem_cgroup_from_mm(task
->mm
);
823 * We should check use_hierarchy of "mem" not "curr". Because checking
824 * use_hierarchy of "curr" here make this function true if hierarchy is
825 * enabled in "curr" and "curr" is a child of "mem" in *cgroup*
826 * hierarchy(even if use_hierarchy is disabled in "mem").
828 if (mem
->use_hierarchy
)
829 ret
= css_is_ancestor(&curr
->css
, &mem
->css
);
837 * prev_priority control...this will be used in memory reclaim path.
839 int mem_cgroup_get_reclaim_priority(struct mem_cgroup
*mem
)
843 spin_lock(&mem
->reclaim_param_lock
);
844 prev_priority
= mem
->prev_priority
;
845 spin_unlock(&mem
->reclaim_param_lock
);
847 return prev_priority
;
850 void mem_cgroup_note_reclaim_priority(struct mem_cgroup
*mem
, int priority
)
852 spin_lock(&mem
->reclaim_param_lock
);
853 if (priority
< mem
->prev_priority
)
854 mem
->prev_priority
= priority
;
855 spin_unlock(&mem
->reclaim_param_lock
);
858 void mem_cgroup_record_reclaim_priority(struct mem_cgroup
*mem
, int priority
)
860 spin_lock(&mem
->reclaim_param_lock
);
861 mem
->prev_priority
= priority
;
862 spin_unlock(&mem
->reclaim_param_lock
);
865 static int calc_inactive_ratio(struct mem_cgroup
*memcg
, unsigned long *present_pages
)
867 unsigned long active
;
868 unsigned long inactive
;
870 unsigned long inactive_ratio
;
872 inactive
= mem_cgroup_get_local_zonestat(memcg
, LRU_INACTIVE_ANON
);
873 active
= mem_cgroup_get_local_zonestat(memcg
, LRU_ACTIVE_ANON
);
875 gb
= (inactive
+ active
) >> (30 - PAGE_SHIFT
);
877 inactive_ratio
= int_sqrt(10 * gb
);
882 present_pages
[0] = inactive
;
883 present_pages
[1] = active
;
886 return inactive_ratio
;
889 int mem_cgroup_inactive_anon_is_low(struct mem_cgroup
*memcg
)
891 unsigned long active
;
892 unsigned long inactive
;
893 unsigned long present_pages
[2];
894 unsigned long inactive_ratio
;
896 inactive_ratio
= calc_inactive_ratio(memcg
, present_pages
);
898 inactive
= present_pages
[0];
899 active
= present_pages
[1];
901 if (inactive
* inactive_ratio
< active
)
907 int mem_cgroup_inactive_file_is_low(struct mem_cgroup
*memcg
)
909 unsigned long active
;
910 unsigned long inactive
;
912 inactive
= mem_cgroup_get_local_zonestat(memcg
, LRU_INACTIVE_FILE
);
913 active
= mem_cgroup_get_local_zonestat(memcg
, LRU_ACTIVE_FILE
);
915 return (active
> inactive
);
918 unsigned long mem_cgroup_zone_nr_pages(struct mem_cgroup
*memcg
,
922 int nid
= zone
->zone_pgdat
->node_id
;
923 int zid
= zone_idx(zone
);
924 struct mem_cgroup_per_zone
*mz
= mem_cgroup_zoneinfo(memcg
, nid
, zid
);
926 return MEM_CGROUP_ZSTAT(mz
, lru
);
929 struct zone_reclaim_stat
*mem_cgroup_get_reclaim_stat(struct mem_cgroup
*memcg
,
932 int nid
= zone
->zone_pgdat
->node_id
;
933 int zid
= zone_idx(zone
);
934 struct mem_cgroup_per_zone
*mz
= mem_cgroup_zoneinfo(memcg
, nid
, zid
);
936 return &mz
->reclaim_stat
;
939 struct zone_reclaim_stat
*
940 mem_cgroup_get_reclaim_stat_from_page(struct page
*page
)
942 struct page_cgroup
*pc
;
943 struct mem_cgroup_per_zone
*mz
;
945 if (mem_cgroup_disabled())
948 pc
= lookup_page_cgroup(page
);
950 * Used bit is set without atomic ops but after smp_wmb().
951 * For making pc->mem_cgroup visible, insert smp_rmb() here.
954 if (!PageCgroupUsed(pc
))
957 mz
= page_cgroup_zoneinfo(pc
);
961 return &mz
->reclaim_stat
;
964 unsigned long mem_cgroup_isolate_pages(unsigned long nr_to_scan
,
965 struct list_head
*dst
,
966 unsigned long *scanned
, int order
,
967 int mode
, struct zone
*z
,
968 struct mem_cgroup
*mem_cont
,
969 int active
, int file
)
971 unsigned long nr_taken
= 0;
975 struct list_head
*src
;
976 struct page_cgroup
*pc
, *tmp
;
977 int nid
= z
->zone_pgdat
->node_id
;
978 int zid
= zone_idx(z
);
979 struct mem_cgroup_per_zone
*mz
;
980 int lru
= LRU_FILE
* file
+ active
;
984 mz
= mem_cgroup_zoneinfo(mem_cont
, nid
, zid
);
985 src
= &mz
->lists
[lru
];
988 list_for_each_entry_safe_reverse(pc
, tmp
, src
, lru
) {
989 if (scan
>= nr_to_scan
)
993 if (unlikely(!PageCgroupUsed(pc
)))
995 if (unlikely(!PageLRU(page
)))
999 ret
= __isolate_lru_page(page
, mode
, file
);
1002 list_move(&page
->lru
, dst
);
1003 mem_cgroup_del_lru(page
);
1007 /* we don't affect global LRU but rotate in our LRU */
1008 mem_cgroup_rotate_lru_list(page
, page_lru(page
));
1019 #define mem_cgroup_from_res_counter(counter, member) \
1020 container_of(counter, struct mem_cgroup, member)
1022 static bool mem_cgroup_check_under_limit(struct mem_cgroup
*mem
)
1024 if (do_swap_account
) {
1025 if (res_counter_check_under_limit(&mem
->res
) &&
1026 res_counter_check_under_limit(&mem
->memsw
))
1029 if (res_counter_check_under_limit(&mem
->res
))
1034 static unsigned int get_swappiness(struct mem_cgroup
*memcg
)
1036 struct cgroup
*cgrp
= memcg
->css
.cgroup
;
1037 unsigned int swappiness
;
1040 if (cgrp
->parent
== NULL
)
1041 return vm_swappiness
;
1043 spin_lock(&memcg
->reclaim_param_lock
);
1044 swappiness
= memcg
->swappiness
;
1045 spin_unlock(&memcg
->reclaim_param_lock
);
1050 static int mem_cgroup_count_children_cb(struct mem_cgroup
*mem
, void *data
)
1058 * mem_cgroup_print_oom_info: Called from OOM with tasklist_lock held in read mode.
1059 * @memcg: The memory cgroup that went over limit
1060 * @p: Task that is going to be killed
1062 * NOTE: @memcg and @p's mem_cgroup can be different when hierarchy is
1065 void mem_cgroup_print_oom_info(struct mem_cgroup
*memcg
, struct task_struct
*p
)
1067 struct cgroup
*task_cgrp
;
1068 struct cgroup
*mem_cgrp
;
1070 * Need a buffer in BSS, can't rely on allocations. The code relies
1071 * on the assumption that OOM is serialized for memory controller.
1072 * If this assumption is broken, revisit this code.
1074 static char memcg_name
[PATH_MAX
];
1083 mem_cgrp
= memcg
->css
.cgroup
;
1084 task_cgrp
= task_cgroup(p
, mem_cgroup_subsys_id
);
1086 ret
= cgroup_path(task_cgrp
, memcg_name
, PATH_MAX
);
1089 * Unfortunately, we are unable to convert to a useful name
1090 * But we'll still print out the usage information
1097 printk(KERN_INFO
"Task in %s killed", memcg_name
);
1100 ret
= cgroup_path(mem_cgrp
, memcg_name
, PATH_MAX
);
1108 * Continues from above, so we don't need an KERN_ level
1110 printk(KERN_CONT
" as a result of limit of %s\n", memcg_name
);
1113 printk(KERN_INFO
"memory: usage %llukB, limit %llukB, failcnt %llu\n",
1114 res_counter_read_u64(&memcg
->res
, RES_USAGE
) >> 10,
1115 res_counter_read_u64(&memcg
->res
, RES_LIMIT
) >> 10,
1116 res_counter_read_u64(&memcg
->res
, RES_FAILCNT
));
1117 printk(KERN_INFO
"memory+swap: usage %llukB, limit %llukB, "
1119 res_counter_read_u64(&memcg
->memsw
, RES_USAGE
) >> 10,
1120 res_counter_read_u64(&memcg
->memsw
, RES_LIMIT
) >> 10,
1121 res_counter_read_u64(&memcg
->memsw
, RES_FAILCNT
));
1125 * This function returns the number of memcg under hierarchy tree. Returns
1126 * 1(self count) if no children.
1128 static int mem_cgroup_count_children(struct mem_cgroup
*mem
)
1131 mem_cgroup_walk_tree(mem
, &num
, mem_cgroup_count_children_cb
);
1136 * Visit the first child (need not be the first child as per the ordering
1137 * of the cgroup list, since we track last_scanned_child) of @mem and use
1138 * that to reclaim free pages from.
1140 static struct mem_cgroup
*
1141 mem_cgroup_select_victim(struct mem_cgroup
*root_mem
)
1143 struct mem_cgroup
*ret
= NULL
;
1144 struct cgroup_subsys_state
*css
;
1147 if (!root_mem
->use_hierarchy
) {
1148 css_get(&root_mem
->css
);
1154 nextid
= root_mem
->last_scanned_child
+ 1;
1155 css
= css_get_next(&mem_cgroup_subsys
, nextid
, &root_mem
->css
,
1157 if (css
&& css_tryget(css
))
1158 ret
= container_of(css
, struct mem_cgroup
, css
);
1161 /* Updates scanning parameter */
1162 spin_lock(&root_mem
->reclaim_param_lock
);
1164 /* this means start scan from ID:1 */
1165 root_mem
->last_scanned_child
= 0;
1167 root_mem
->last_scanned_child
= found
;
1168 spin_unlock(&root_mem
->reclaim_param_lock
);
1175 * Scan the hierarchy if needed to reclaim memory. We remember the last child
1176 * we reclaimed from, so that we don't end up penalizing one child extensively
1177 * based on its position in the children list.
1179 * root_mem is the original ancestor that we've been reclaim from.
1181 * We give up and return to the caller when we visit root_mem twice.
1182 * (other groups can be removed while we're walking....)
1184 * If shrink==true, for avoiding to free too much, this returns immedieately.
1186 static int mem_cgroup_hierarchical_reclaim(struct mem_cgroup
*root_mem
,
1189 unsigned long reclaim_options
)
1191 struct mem_cgroup
*victim
;
1194 bool noswap
= reclaim_options
& MEM_CGROUP_RECLAIM_NOSWAP
;
1195 bool shrink
= reclaim_options
& MEM_CGROUP_RECLAIM_SHRINK
;
1196 bool check_soft
= reclaim_options
& MEM_CGROUP_RECLAIM_SOFT
;
1197 unsigned long excess
= mem_cgroup_get_excess(root_mem
);
1199 /* If memsw_is_minimum==1, swap-out is of-no-use. */
1200 if (root_mem
->memsw_is_minimum
)
1204 victim
= mem_cgroup_select_victim(root_mem
);
1205 if (victim
== root_mem
) {
1208 drain_all_stock_async();
1211 * If we have not been able to reclaim
1212 * anything, it might because there are
1213 * no reclaimable pages under this hierarchy
1215 if (!check_soft
|| !total
) {
1216 css_put(&victim
->css
);
1220 * We want to do more targetted reclaim.
1221 * excess >> 2 is not to excessive so as to
1222 * reclaim too much, nor too less that we keep
1223 * coming back to reclaim from this cgroup
1225 if (total
>= (excess
>> 2) ||
1226 (loop
> MEM_CGROUP_MAX_RECLAIM_LOOPS
)) {
1227 css_put(&victim
->css
);
1232 if (!mem_cgroup_local_usage(victim
)) {
1233 /* this cgroup's local usage == 0 */
1234 css_put(&victim
->css
);
1237 /* we use swappiness of local cgroup */
1239 ret
= mem_cgroup_shrink_node_zone(victim
, gfp_mask
,
1240 noswap
, get_swappiness(victim
), zone
,
1241 zone
->zone_pgdat
->node_id
);
1243 ret
= try_to_free_mem_cgroup_pages(victim
, gfp_mask
,
1244 noswap
, get_swappiness(victim
));
1245 css_put(&victim
->css
);
1247 * At shrinking usage, we can't check we should stop here or
1248 * reclaim more. It's depends on callers. last_scanned_child
1249 * will work enough for keeping fairness under tree.
1255 if (res_counter_check_under_soft_limit(&root_mem
->res
))
1257 } else if (mem_cgroup_check_under_limit(root_mem
))
1263 static int mem_cgroup_oom_lock_cb(struct mem_cgroup
*mem
, void *data
)
1265 int *val
= (int *)data
;
1268 * Logically, we can stop scanning immediately when we find
1269 * a memcg is already locked. But condidering unlock ops and
1270 * creation/removal of memcg, scan-all is simple operation.
1272 x
= atomic_inc_return(&mem
->oom_lock
);
1273 *val
= max(x
, *val
);
1277 * Check OOM-Killer is already running under our hierarchy.
1278 * If someone is running, return false.
1280 static bool mem_cgroup_oom_lock(struct mem_cgroup
*mem
)
1284 mem_cgroup_walk_tree(mem
, &lock_count
, mem_cgroup_oom_lock_cb
);
1286 if (lock_count
== 1)
1291 static int mem_cgroup_oom_unlock_cb(struct mem_cgroup
*mem
, void *data
)
1294 * When a new child is created while the hierarchy is under oom,
1295 * mem_cgroup_oom_lock() may not be called. We have to use
1296 * atomic_add_unless() here.
1298 atomic_add_unless(&mem
->oom_lock
, -1, 0);
1302 static void mem_cgroup_oom_unlock(struct mem_cgroup
*mem
)
1304 mem_cgroup_walk_tree(mem
, NULL
, mem_cgroup_oom_unlock_cb
);
1307 static DEFINE_MUTEX(memcg_oom_mutex
);
1308 static DECLARE_WAIT_QUEUE_HEAD(memcg_oom_waitq
);
1310 struct oom_wait_info
{
1311 struct mem_cgroup
*mem
;
1315 static int memcg_oom_wake_function(wait_queue_t
*wait
,
1316 unsigned mode
, int sync
, void *arg
)
1318 struct mem_cgroup
*wake_mem
= (struct mem_cgroup
*)arg
;
1319 struct oom_wait_info
*oom_wait_info
;
1321 oom_wait_info
= container_of(wait
, struct oom_wait_info
, wait
);
1323 if (oom_wait_info
->mem
== wake_mem
)
1325 /* if no hierarchy, no match */
1326 if (!oom_wait_info
->mem
->use_hierarchy
|| !wake_mem
->use_hierarchy
)
1329 * Both of oom_wait_info->mem and wake_mem are stable under us.
1330 * Then we can use css_is_ancestor without taking care of RCU.
1332 if (!css_is_ancestor(&oom_wait_info
->mem
->css
, &wake_mem
->css
) &&
1333 !css_is_ancestor(&wake_mem
->css
, &oom_wait_info
->mem
->css
))
1337 return autoremove_wake_function(wait
, mode
, sync
, arg
);
1340 static void memcg_wakeup_oom(struct mem_cgroup
*mem
)
1342 /* for filtering, pass "mem" as argument. */
1343 __wake_up(&memcg_oom_waitq
, TASK_NORMAL
, 0, mem
);
1346 static void memcg_oom_recover(struct mem_cgroup
*mem
)
1348 if (mem
->oom_kill_disable
&& atomic_read(&mem
->oom_lock
))
1349 memcg_wakeup_oom(mem
);
1353 * try to call OOM killer. returns false if we should exit memory-reclaim loop.
1355 bool mem_cgroup_handle_oom(struct mem_cgroup
*mem
, gfp_t mask
)
1357 struct oom_wait_info owait
;
1358 bool locked
, need_to_kill
;
1361 owait
.wait
.flags
= 0;
1362 owait
.wait
.func
= memcg_oom_wake_function
;
1363 owait
.wait
.private = current
;
1364 INIT_LIST_HEAD(&owait
.wait
.task_list
);
1365 need_to_kill
= true;
1366 /* At first, try to OOM lock hierarchy under mem.*/
1367 mutex_lock(&memcg_oom_mutex
);
1368 locked
= mem_cgroup_oom_lock(mem
);
1370 * Even if signal_pending(), we can't quit charge() loop without
1371 * accounting. So, UNINTERRUPTIBLE is appropriate. But SIGKILL
1372 * under OOM is always welcomed, use TASK_KILLABLE here.
1374 prepare_to_wait(&memcg_oom_waitq
, &owait
.wait
, TASK_KILLABLE
);
1375 if (!locked
|| mem
->oom_kill_disable
)
1376 need_to_kill
= false;
1378 mem_cgroup_oom_notify(mem
);
1379 mutex_unlock(&memcg_oom_mutex
);
1382 finish_wait(&memcg_oom_waitq
, &owait
.wait
);
1383 mem_cgroup_out_of_memory(mem
, mask
);
1386 finish_wait(&memcg_oom_waitq
, &owait
.wait
);
1388 mutex_lock(&memcg_oom_mutex
);
1389 mem_cgroup_oom_unlock(mem
);
1390 memcg_wakeup_oom(mem
);
1391 mutex_unlock(&memcg_oom_mutex
);
1393 if (test_thread_flag(TIF_MEMDIE
) || fatal_signal_pending(current
))
1395 /* Give chance to dying process */
1396 schedule_timeout(1);
1401 * Currently used to update mapped file statistics, but the routine can be
1402 * generalized to update other statistics as well.
1404 void mem_cgroup_update_file_mapped(struct page
*page
, int val
)
1406 struct mem_cgroup
*mem
;
1407 struct page_cgroup
*pc
;
1409 pc
= lookup_page_cgroup(page
);
1413 lock_page_cgroup(pc
);
1414 mem
= pc
->mem_cgroup
;
1415 if (!mem
|| !PageCgroupUsed(pc
))
1419 * Preemption is already disabled. We can use __this_cpu_xxx
1422 __this_cpu_inc(mem
->stat
->count
[MEM_CGROUP_STAT_FILE_MAPPED
]);
1423 SetPageCgroupFileMapped(pc
);
1425 __this_cpu_dec(mem
->stat
->count
[MEM_CGROUP_STAT_FILE_MAPPED
]);
1426 ClearPageCgroupFileMapped(pc
);
1430 unlock_page_cgroup(pc
);
1434 * size of first charge trial. "32" comes from vmscan.c's magic value.
1435 * TODO: maybe necessary to use big numbers in big irons.
1437 #define CHARGE_SIZE (32 * PAGE_SIZE)
1438 struct memcg_stock_pcp
{
1439 struct mem_cgroup
*cached
; /* this never be root cgroup */
1441 struct work_struct work
;
1443 static DEFINE_PER_CPU(struct memcg_stock_pcp
, memcg_stock
);
1444 static atomic_t memcg_drain_count
;
1447 * Try to consume stocked charge on this cpu. If success, PAGE_SIZE is consumed
1448 * from local stock and true is returned. If the stock is 0 or charges from a
1449 * cgroup which is not current target, returns false. This stock will be
1452 static bool consume_stock(struct mem_cgroup
*mem
)
1454 struct memcg_stock_pcp
*stock
;
1457 stock
= &get_cpu_var(memcg_stock
);
1458 if (mem
== stock
->cached
&& stock
->charge
)
1459 stock
->charge
-= PAGE_SIZE
;
1460 else /* need to call res_counter_charge */
1462 put_cpu_var(memcg_stock
);
1467 * Returns stocks cached in percpu to res_counter and reset cached information.
1469 static void drain_stock(struct memcg_stock_pcp
*stock
)
1471 struct mem_cgroup
*old
= stock
->cached
;
1473 if (stock
->charge
) {
1474 res_counter_uncharge(&old
->res
, stock
->charge
);
1475 if (do_swap_account
)
1476 res_counter_uncharge(&old
->memsw
, stock
->charge
);
1478 stock
->cached
= NULL
;
1483 * This must be called under preempt disabled or must be called by
1484 * a thread which is pinned to local cpu.
1486 static void drain_local_stock(struct work_struct
*dummy
)
1488 struct memcg_stock_pcp
*stock
= &__get_cpu_var(memcg_stock
);
1493 * Cache charges(val) which is from res_counter, to local per_cpu area.
1494 * This will be consumed by consume_stock() function, later.
1496 static void refill_stock(struct mem_cgroup
*mem
, int val
)
1498 struct memcg_stock_pcp
*stock
= &get_cpu_var(memcg_stock
);
1500 if (stock
->cached
!= mem
) { /* reset if necessary */
1502 stock
->cached
= mem
;
1504 stock
->charge
+= val
;
1505 put_cpu_var(memcg_stock
);
1509 * Tries to drain stocked charges in other cpus. This function is asynchronous
1510 * and just put a work per cpu for draining localy on each cpu. Caller can
1511 * expects some charges will be back to res_counter later but cannot wait for
1514 static void drain_all_stock_async(void)
1517 /* This function is for scheduling "drain" in asynchronous way.
1518 * The result of "drain" is not directly handled by callers. Then,
1519 * if someone is calling drain, we don't have to call drain more.
1520 * Anyway, WORK_STRUCT_PENDING check in queue_work_on() will catch if
1521 * there is a race. We just do loose check here.
1523 if (atomic_read(&memcg_drain_count
))
1525 /* Notify other cpus that system-wide "drain" is running */
1526 atomic_inc(&memcg_drain_count
);
1528 for_each_online_cpu(cpu
) {
1529 struct memcg_stock_pcp
*stock
= &per_cpu(memcg_stock
, cpu
);
1530 schedule_work_on(cpu
, &stock
->work
);
1533 atomic_dec(&memcg_drain_count
);
1534 /* We don't wait for flush_work */
1537 /* This is a synchronous drain interface. */
1538 static void drain_all_stock_sync(void)
1540 /* called when force_empty is called */
1541 atomic_inc(&memcg_drain_count
);
1542 schedule_on_each_cpu(drain_local_stock
);
1543 atomic_dec(&memcg_drain_count
);
1546 static int __cpuinit
memcg_stock_cpu_callback(struct notifier_block
*nb
,
1547 unsigned long action
,
1550 int cpu
= (unsigned long)hcpu
;
1551 struct memcg_stock_pcp
*stock
;
1553 if (action
!= CPU_DEAD
)
1555 stock
= &per_cpu(memcg_stock
, cpu
);
1561 * Unlike exported interface, "oom" parameter is added. if oom==true,
1562 * oom-killer can be invoked.
1564 static int __mem_cgroup_try_charge(struct mm_struct
*mm
,
1565 gfp_t gfp_mask
, struct mem_cgroup
**memcg
, bool oom
)
1567 struct mem_cgroup
*mem
, *mem_over_limit
;
1568 int nr_retries
= MEM_CGROUP_RECLAIM_RETRIES
;
1569 struct res_counter
*fail_res
;
1570 int csize
= CHARGE_SIZE
;
1573 * Unlike gloval-vm's OOM-kill, we're not in memory shortage
1574 * in system level. So, allow to go ahead dying process in addition to
1577 if (unlikely(test_thread_flag(TIF_MEMDIE
)
1578 || fatal_signal_pending(current
)))
1582 * We always charge the cgroup the mm_struct belongs to.
1583 * The mm_struct's mem_cgroup changes on task migration if the
1584 * thread group leader migrates. It's possible that mm is not
1585 * set, if so charge the init_mm (happens for pagecache usage).
1589 mem
= try_get_mem_cgroup_from_mm(mm
);
1597 VM_BUG_ON(css_is_removed(&mem
->css
));
1598 if (mem_cgroup_is_root(mem
))
1603 unsigned long flags
= 0;
1605 if (consume_stock(mem
))
1608 ret
= res_counter_charge(&mem
->res
, csize
, &fail_res
);
1610 if (!do_swap_account
)
1612 ret
= res_counter_charge(&mem
->memsw
, csize
, &fail_res
);
1615 /* mem+swap counter fails */
1616 res_counter_uncharge(&mem
->res
, csize
);
1617 flags
|= MEM_CGROUP_RECLAIM_NOSWAP
;
1618 mem_over_limit
= mem_cgroup_from_res_counter(fail_res
,
1621 /* mem counter fails */
1622 mem_over_limit
= mem_cgroup_from_res_counter(fail_res
,
1625 /* reduce request size and retry */
1626 if (csize
> PAGE_SIZE
) {
1630 if (!(gfp_mask
& __GFP_WAIT
))
1633 ret
= mem_cgroup_hierarchical_reclaim(mem_over_limit
, NULL
,
1639 * try_to_free_mem_cgroup_pages() might not give us a full
1640 * picture of reclaim. Some pages are reclaimed and might be
1641 * moved to swap cache or just unmapped from the cgroup.
1642 * Check the limit again to see if the reclaim reduced the
1643 * current usage of the cgroup before giving up
1646 if (mem_cgroup_check_under_limit(mem_over_limit
))
1649 /* try to avoid oom while someone is moving charge */
1650 if (mc
.moving_task
&& current
!= mc
.moving_task
) {
1651 struct mem_cgroup
*from
, *to
;
1652 bool do_continue
= false;
1654 * There is a small race that "from" or "to" can be
1655 * freed by rmdir, so we use css_tryget().
1659 if (from
&& css_tryget(&from
->css
)) {
1660 if (mem_over_limit
->use_hierarchy
)
1661 do_continue
= css_is_ancestor(
1663 &mem_over_limit
->css
);
1665 do_continue
= (from
== mem_over_limit
);
1666 css_put(&from
->css
);
1668 if (!do_continue
&& to
&& css_tryget(&to
->css
)) {
1669 if (mem_over_limit
->use_hierarchy
)
1670 do_continue
= css_is_ancestor(
1672 &mem_over_limit
->css
);
1674 do_continue
= (to
== mem_over_limit
);
1679 prepare_to_wait(&mc
.waitq
, &wait
,
1680 TASK_INTERRUPTIBLE
);
1681 /* moving charge context might have finished. */
1684 finish_wait(&mc
.waitq
, &wait
);
1689 if (!nr_retries
--) {
1692 if (mem_cgroup_handle_oom(mem_over_limit
, gfp_mask
)) {
1693 nr_retries
= MEM_CGROUP_RECLAIM_RETRIES
;
1696 /* When we reach here, current task is dying .*/
1701 if (csize
> PAGE_SIZE
)
1702 refill_stock(mem
, csize
- PAGE_SIZE
);
1714 * Somemtimes we have to undo a charge we got by try_charge().
1715 * This function is for that and do uncharge, put css's refcnt.
1716 * gotten by try_charge().
1718 static void __mem_cgroup_cancel_charge(struct mem_cgroup
*mem
,
1719 unsigned long count
)
1721 if (!mem_cgroup_is_root(mem
)) {
1722 res_counter_uncharge(&mem
->res
, PAGE_SIZE
* count
);
1723 if (do_swap_account
)
1724 res_counter_uncharge(&mem
->memsw
, PAGE_SIZE
* count
);
1725 VM_BUG_ON(test_bit(CSS_ROOT
, &mem
->css
.flags
));
1726 WARN_ON_ONCE(count
> INT_MAX
);
1727 __css_put(&mem
->css
, (int)count
);
1729 /* we don't need css_put for root */
1732 static void mem_cgroup_cancel_charge(struct mem_cgroup
*mem
)
1734 __mem_cgroup_cancel_charge(mem
, 1);
1738 * A helper function to get mem_cgroup from ID. must be called under
1739 * rcu_read_lock(). The caller must check css_is_removed() or some if
1740 * it's concern. (dropping refcnt from swap can be called against removed
1743 static struct mem_cgroup
*mem_cgroup_lookup(unsigned short id
)
1745 struct cgroup_subsys_state
*css
;
1747 /* ID 0 is unused ID */
1750 css
= css_lookup(&mem_cgroup_subsys
, id
);
1753 return container_of(css
, struct mem_cgroup
, css
);
1756 struct mem_cgroup
*try_get_mem_cgroup_from_page(struct page
*page
)
1758 struct mem_cgroup
*mem
= NULL
;
1759 struct page_cgroup
*pc
;
1763 VM_BUG_ON(!PageLocked(page
));
1765 pc
= lookup_page_cgroup(page
);
1766 lock_page_cgroup(pc
);
1767 if (PageCgroupUsed(pc
)) {
1768 mem
= pc
->mem_cgroup
;
1769 if (mem
&& !css_tryget(&mem
->css
))
1771 } else if (PageSwapCache(page
)) {
1772 ent
.val
= page_private(page
);
1773 id
= lookup_swap_cgroup(ent
);
1775 mem
= mem_cgroup_lookup(id
);
1776 if (mem
&& !css_tryget(&mem
->css
))
1780 unlock_page_cgroup(pc
);
1785 * commit a charge got by __mem_cgroup_try_charge() and makes page_cgroup to be
1786 * USED state. If already USED, uncharge and return.
1789 static void __mem_cgroup_commit_charge(struct mem_cgroup
*mem
,
1790 struct page_cgroup
*pc
,
1791 enum charge_type ctype
)
1793 /* try_charge() can return NULL to *memcg, taking care of it. */
1797 lock_page_cgroup(pc
);
1798 if (unlikely(PageCgroupUsed(pc
))) {
1799 unlock_page_cgroup(pc
);
1800 mem_cgroup_cancel_charge(mem
);
1804 pc
->mem_cgroup
= mem
;
1806 * We access a page_cgroup asynchronously without lock_page_cgroup().
1807 * Especially when a page_cgroup is taken from a page, pc->mem_cgroup
1808 * is accessed after testing USED bit. To make pc->mem_cgroup visible
1809 * before USED bit, we need memory barrier here.
1810 * See mem_cgroup_add_lru_list(), etc.
1814 case MEM_CGROUP_CHARGE_TYPE_CACHE
:
1815 case MEM_CGROUP_CHARGE_TYPE_SHMEM
:
1816 SetPageCgroupCache(pc
);
1817 SetPageCgroupUsed(pc
);
1819 case MEM_CGROUP_CHARGE_TYPE_MAPPED
:
1820 ClearPageCgroupCache(pc
);
1821 SetPageCgroupUsed(pc
);
1827 mem_cgroup_charge_statistics(mem
, pc
, true);
1829 unlock_page_cgroup(pc
);
1831 * "charge_statistics" updated event counter. Then, check it.
1832 * Insert ancestor (and ancestor's ancestors), to softlimit RB-tree.
1833 * if they exceeds softlimit.
1835 memcg_check_events(mem
, pc
->page
);
1839 * __mem_cgroup_move_account - move account of the page
1840 * @pc: page_cgroup of the page.
1841 * @from: mem_cgroup which the page is moved from.
1842 * @to: mem_cgroup which the page is moved to. @from != @to.
1843 * @uncharge: whether we should call uncharge and css_put against @from.
1845 * The caller must confirm following.
1846 * - page is not on LRU (isolate_page() is useful.)
1847 * - the pc is locked, used, and ->mem_cgroup points to @from.
1849 * This function doesn't do "charge" nor css_get to new cgroup. It should be
1850 * done by a caller(__mem_cgroup_try_charge would be usefull). If @uncharge is
1851 * true, this function does "uncharge" from old cgroup, but it doesn't if
1852 * @uncharge is false, so a caller should do "uncharge".
1855 static void __mem_cgroup_move_account(struct page_cgroup
*pc
,
1856 struct mem_cgroup
*from
, struct mem_cgroup
*to
, bool uncharge
)
1858 VM_BUG_ON(from
== to
);
1859 VM_BUG_ON(PageLRU(pc
->page
));
1860 VM_BUG_ON(!PageCgroupLocked(pc
));
1861 VM_BUG_ON(!PageCgroupUsed(pc
));
1862 VM_BUG_ON(pc
->mem_cgroup
!= from
);
1864 if (PageCgroupFileMapped(pc
)) {
1865 /* Update mapped_file data for mem_cgroup */
1867 __this_cpu_dec(from
->stat
->count
[MEM_CGROUP_STAT_FILE_MAPPED
]);
1868 __this_cpu_inc(to
->stat
->count
[MEM_CGROUP_STAT_FILE_MAPPED
]);
1871 mem_cgroup_charge_statistics(from
, pc
, false);
1873 /* This is not "cancel", but cancel_charge does all we need. */
1874 mem_cgroup_cancel_charge(from
);
1876 /* caller should have done css_get */
1877 pc
->mem_cgroup
= to
;
1878 mem_cgroup_charge_statistics(to
, pc
, true);
1880 * We charges against "to" which may not have any tasks. Then, "to"
1881 * can be under rmdir(). But in current implementation, caller of
1882 * this function is just force_empty() and move charge, so it's
1883 * garanteed that "to" is never removed. So, we don't check rmdir
1889 * check whether the @pc is valid for moving account and call
1890 * __mem_cgroup_move_account()
1892 static int mem_cgroup_move_account(struct page_cgroup
*pc
,
1893 struct mem_cgroup
*from
, struct mem_cgroup
*to
, bool uncharge
)
1896 lock_page_cgroup(pc
);
1897 if (PageCgroupUsed(pc
) && pc
->mem_cgroup
== from
) {
1898 __mem_cgroup_move_account(pc
, from
, to
, uncharge
);
1901 unlock_page_cgroup(pc
);
1905 memcg_check_events(to
, pc
->page
);
1906 memcg_check_events(from
, pc
->page
);
1911 * move charges to its parent.
1914 static int mem_cgroup_move_parent(struct page_cgroup
*pc
,
1915 struct mem_cgroup
*child
,
1918 struct page
*page
= pc
->page
;
1919 struct cgroup
*cg
= child
->css
.cgroup
;
1920 struct cgroup
*pcg
= cg
->parent
;
1921 struct mem_cgroup
*parent
;
1929 if (!get_page_unless_zero(page
))
1931 if (isolate_lru_page(page
))
1934 parent
= mem_cgroup_from_cont(pcg
);
1935 ret
= __mem_cgroup_try_charge(NULL
, gfp_mask
, &parent
, false);
1939 ret
= mem_cgroup_move_account(pc
, child
, parent
, true);
1941 mem_cgroup_cancel_charge(parent
);
1943 putback_lru_page(page
);
1951 * Charge the memory controller for page usage.
1953 * 0 if the charge was successful
1954 * < 0 if the cgroup is over its limit
1956 static int mem_cgroup_charge_common(struct page
*page
, struct mm_struct
*mm
,
1957 gfp_t gfp_mask
, enum charge_type ctype
,
1958 struct mem_cgroup
*memcg
)
1960 struct mem_cgroup
*mem
;
1961 struct page_cgroup
*pc
;
1964 pc
= lookup_page_cgroup(page
);
1965 /* can happen at boot */
1971 ret
= __mem_cgroup_try_charge(mm
, gfp_mask
, &mem
, true);
1975 __mem_cgroup_commit_charge(mem
, pc
, ctype
);
1979 int mem_cgroup_newpage_charge(struct page
*page
,
1980 struct mm_struct
*mm
, gfp_t gfp_mask
)
1982 if (mem_cgroup_disabled())
1984 if (PageCompound(page
))
1987 * If already mapped, we don't have to account.
1988 * If page cache, page->mapping has address_space.
1989 * But page->mapping may have out-of-use anon_vma pointer,
1990 * detecit it by PageAnon() check. newly-mapped-anon's page->mapping
1993 if (page_mapped(page
) || (page
->mapping
&& !PageAnon(page
)))
1997 return mem_cgroup_charge_common(page
, mm
, gfp_mask
,
1998 MEM_CGROUP_CHARGE_TYPE_MAPPED
, NULL
);
2002 __mem_cgroup_commit_charge_swapin(struct page
*page
, struct mem_cgroup
*ptr
,
2003 enum charge_type ctype
);
2005 int mem_cgroup_cache_charge(struct page
*page
, struct mm_struct
*mm
,
2008 struct mem_cgroup
*mem
= NULL
;
2011 if (mem_cgroup_disabled())
2013 if (PageCompound(page
))
2016 * Corner case handling. This is called from add_to_page_cache()
2017 * in usual. But some FS (shmem) precharges this page before calling it
2018 * and call add_to_page_cache() with GFP_NOWAIT.
2020 * For GFP_NOWAIT case, the page may be pre-charged before calling
2021 * add_to_page_cache(). (See shmem.c) check it here and avoid to call
2022 * charge twice. (It works but has to pay a bit larger cost.)
2023 * And when the page is SwapCache, it should take swap information
2024 * into account. This is under lock_page() now.
2026 if (!(gfp_mask
& __GFP_WAIT
)) {
2027 struct page_cgroup
*pc
;
2030 pc
= lookup_page_cgroup(page
);
2033 lock_page_cgroup(pc
);
2034 if (PageCgroupUsed(pc
)) {
2035 unlock_page_cgroup(pc
);
2038 unlock_page_cgroup(pc
);
2041 if (unlikely(!mm
&& !mem
))
2044 if (page_is_file_cache(page
))
2045 return mem_cgroup_charge_common(page
, mm
, gfp_mask
,
2046 MEM_CGROUP_CHARGE_TYPE_CACHE
, NULL
);
2049 if (PageSwapCache(page
)) {
2050 ret
= mem_cgroup_try_charge_swapin(mm
, page
, gfp_mask
, &mem
);
2052 __mem_cgroup_commit_charge_swapin(page
, mem
,
2053 MEM_CGROUP_CHARGE_TYPE_SHMEM
);
2055 ret
= mem_cgroup_charge_common(page
, mm
, gfp_mask
,
2056 MEM_CGROUP_CHARGE_TYPE_SHMEM
, mem
);
2062 * While swap-in, try_charge -> commit or cancel, the page is locked.
2063 * And when try_charge() successfully returns, one refcnt to memcg without
2064 * struct page_cgroup is acquired. This refcnt will be consumed by
2065 * "commit()" or removed by "cancel()"
2067 int mem_cgroup_try_charge_swapin(struct mm_struct
*mm
,
2069 gfp_t mask
, struct mem_cgroup
**ptr
)
2071 struct mem_cgroup
*mem
;
2074 if (mem_cgroup_disabled())
2077 if (!do_swap_account
)
2080 * A racing thread's fault, or swapoff, may have already updated
2081 * the pte, and even removed page from swap cache: in those cases
2082 * do_swap_page()'s pte_same() test will fail; but there's also a
2083 * KSM case which does need to charge the page.
2085 if (!PageSwapCache(page
))
2087 mem
= try_get_mem_cgroup_from_page(page
);
2091 ret
= __mem_cgroup_try_charge(NULL
, mask
, ptr
, true);
2092 /* drop extra refcnt from tryget */
2098 return __mem_cgroup_try_charge(mm
, mask
, ptr
, true);
2102 __mem_cgroup_commit_charge_swapin(struct page
*page
, struct mem_cgroup
*ptr
,
2103 enum charge_type ctype
)
2105 struct page_cgroup
*pc
;
2107 if (mem_cgroup_disabled())
2111 cgroup_exclude_rmdir(&ptr
->css
);
2112 pc
= lookup_page_cgroup(page
);
2113 mem_cgroup_lru_del_before_commit_swapcache(page
);
2114 __mem_cgroup_commit_charge(ptr
, pc
, ctype
);
2115 mem_cgroup_lru_add_after_commit_swapcache(page
);
2117 * Now swap is on-memory. This means this page may be
2118 * counted both as mem and swap....double count.
2119 * Fix it by uncharging from memsw. Basically, this SwapCache is stable
2120 * under lock_page(). But in do_swap_page()::memory.c, reuse_swap_page()
2121 * may call delete_from_swap_cache() before reach here.
2123 if (do_swap_account
&& PageSwapCache(page
)) {
2124 swp_entry_t ent
= {.val
= page_private(page
)};
2126 struct mem_cgroup
*memcg
;
2128 id
= swap_cgroup_record(ent
, 0);
2130 memcg
= mem_cgroup_lookup(id
);
2133 * This recorded memcg can be obsolete one. So, avoid
2134 * calling css_tryget
2136 if (!mem_cgroup_is_root(memcg
))
2137 res_counter_uncharge(&memcg
->memsw
, PAGE_SIZE
);
2138 mem_cgroup_swap_statistics(memcg
, false);
2139 mem_cgroup_put(memcg
);
2144 * At swapin, we may charge account against cgroup which has no tasks.
2145 * So, rmdir()->pre_destroy() can be called while we do this charge.
2146 * In that case, we need to call pre_destroy() again. check it here.
2148 cgroup_release_and_wakeup_rmdir(&ptr
->css
);
2151 void mem_cgroup_commit_charge_swapin(struct page
*page
, struct mem_cgroup
*ptr
)
2153 __mem_cgroup_commit_charge_swapin(page
, ptr
,
2154 MEM_CGROUP_CHARGE_TYPE_MAPPED
);
2157 void mem_cgroup_cancel_charge_swapin(struct mem_cgroup
*mem
)
2159 if (mem_cgroup_disabled())
2163 mem_cgroup_cancel_charge(mem
);
2167 __do_uncharge(struct mem_cgroup
*mem
, const enum charge_type ctype
)
2169 struct memcg_batch_info
*batch
= NULL
;
2170 bool uncharge_memsw
= true;
2171 /* If swapout, usage of swap doesn't decrease */
2172 if (!do_swap_account
|| ctype
== MEM_CGROUP_CHARGE_TYPE_SWAPOUT
)
2173 uncharge_memsw
= false;
2175 batch
= ¤t
->memcg_batch
;
2177 * In usual, we do css_get() when we remember memcg pointer.
2178 * But in this case, we keep res->usage until end of a series of
2179 * uncharges. Then, it's ok to ignore memcg's refcnt.
2184 * do_batch > 0 when unmapping pages or inode invalidate/truncate.
2185 * In those cases, all pages freed continously can be expected to be in
2186 * the same cgroup and we have chance to coalesce uncharges.
2187 * But we do uncharge one by one if this is killed by OOM(TIF_MEMDIE)
2188 * because we want to do uncharge as soon as possible.
2191 if (!batch
->do_batch
|| test_thread_flag(TIF_MEMDIE
))
2192 goto direct_uncharge
;
2195 * In typical case, batch->memcg == mem. This means we can
2196 * merge a series of uncharges to an uncharge of res_counter.
2197 * If not, we uncharge res_counter ony by one.
2199 if (batch
->memcg
!= mem
)
2200 goto direct_uncharge
;
2201 /* remember freed charge and uncharge it later */
2202 batch
->bytes
+= PAGE_SIZE
;
2204 batch
->memsw_bytes
+= PAGE_SIZE
;
2207 res_counter_uncharge(&mem
->res
, PAGE_SIZE
);
2209 res_counter_uncharge(&mem
->memsw
, PAGE_SIZE
);
2210 if (unlikely(batch
->memcg
!= mem
))
2211 memcg_oom_recover(mem
);
2216 * uncharge if !page_mapped(page)
2218 static struct mem_cgroup
*
2219 __mem_cgroup_uncharge_common(struct page
*page
, enum charge_type ctype
)
2221 struct page_cgroup
*pc
;
2222 struct mem_cgroup
*mem
= NULL
;
2223 struct mem_cgroup_per_zone
*mz
;
2225 if (mem_cgroup_disabled())
2228 if (PageSwapCache(page
))
2232 * Check if our page_cgroup is valid
2234 pc
= lookup_page_cgroup(page
);
2235 if (unlikely(!pc
|| !PageCgroupUsed(pc
)))
2238 lock_page_cgroup(pc
);
2240 mem
= pc
->mem_cgroup
;
2242 if (!PageCgroupUsed(pc
))
2246 case MEM_CGROUP_CHARGE_TYPE_MAPPED
:
2247 case MEM_CGROUP_CHARGE_TYPE_DROP
:
2248 if (page_mapped(page
))
2251 case MEM_CGROUP_CHARGE_TYPE_SWAPOUT
:
2252 if (!PageAnon(page
)) { /* Shared memory */
2253 if (page
->mapping
&& !page_is_file_cache(page
))
2255 } else if (page_mapped(page
)) /* Anon */
2262 if (!mem_cgroup_is_root(mem
))
2263 __do_uncharge(mem
, ctype
);
2264 if (ctype
== MEM_CGROUP_CHARGE_TYPE_SWAPOUT
)
2265 mem_cgroup_swap_statistics(mem
, true);
2266 mem_cgroup_charge_statistics(mem
, pc
, false);
2268 ClearPageCgroupUsed(pc
);
2270 * pc->mem_cgroup is not cleared here. It will be accessed when it's
2271 * freed from LRU. This is safe because uncharged page is expected not
2272 * to be reused (freed soon). Exception is SwapCache, it's handled by
2273 * special functions.
2276 mz
= page_cgroup_zoneinfo(pc
);
2277 unlock_page_cgroup(pc
);
2279 memcg_check_events(mem
, page
);
2280 /* at swapout, this memcg will be accessed to record to swap */
2281 if (ctype
!= MEM_CGROUP_CHARGE_TYPE_SWAPOUT
)
2287 unlock_page_cgroup(pc
);
2291 void mem_cgroup_uncharge_page(struct page
*page
)
2294 if (page_mapped(page
))
2296 if (page
->mapping
&& !PageAnon(page
))
2298 __mem_cgroup_uncharge_common(page
, MEM_CGROUP_CHARGE_TYPE_MAPPED
);
2301 void mem_cgroup_uncharge_cache_page(struct page
*page
)
2303 VM_BUG_ON(page_mapped(page
));
2304 VM_BUG_ON(page
->mapping
);
2305 __mem_cgroup_uncharge_common(page
, MEM_CGROUP_CHARGE_TYPE_CACHE
);
2309 * Batch_start/batch_end is called in unmap_page_range/invlidate/trucate.
2310 * In that cases, pages are freed continuously and we can expect pages
2311 * are in the same memcg. All these calls itself limits the number of
2312 * pages freed at once, then uncharge_start/end() is called properly.
2313 * This may be called prural(2) times in a context,
2316 void mem_cgroup_uncharge_start(void)
2318 current
->memcg_batch
.do_batch
++;
2319 /* We can do nest. */
2320 if (current
->memcg_batch
.do_batch
== 1) {
2321 current
->memcg_batch
.memcg
= NULL
;
2322 current
->memcg_batch
.bytes
= 0;
2323 current
->memcg_batch
.memsw_bytes
= 0;
2327 void mem_cgroup_uncharge_end(void)
2329 struct memcg_batch_info
*batch
= ¤t
->memcg_batch
;
2331 if (!batch
->do_batch
)
2335 if (batch
->do_batch
) /* If stacked, do nothing. */
2341 * This "batch->memcg" is valid without any css_get/put etc...
2342 * bacause we hide charges behind us.
2345 res_counter_uncharge(&batch
->memcg
->res
, batch
->bytes
);
2346 if (batch
->memsw_bytes
)
2347 res_counter_uncharge(&batch
->memcg
->memsw
, batch
->memsw_bytes
);
2348 memcg_oom_recover(batch
->memcg
);
2349 /* forget this pointer (for sanity check) */
2350 batch
->memcg
= NULL
;
2355 * called after __delete_from_swap_cache() and drop "page" account.
2356 * memcg information is recorded to swap_cgroup of "ent"
2359 mem_cgroup_uncharge_swapcache(struct page
*page
, swp_entry_t ent
, bool swapout
)
2361 struct mem_cgroup
*memcg
;
2362 int ctype
= MEM_CGROUP_CHARGE_TYPE_SWAPOUT
;
2364 if (!swapout
) /* this was a swap cache but the swap is unused ! */
2365 ctype
= MEM_CGROUP_CHARGE_TYPE_DROP
;
2367 memcg
= __mem_cgroup_uncharge_common(page
, ctype
);
2369 /* record memcg information */
2370 if (do_swap_account
&& swapout
&& memcg
) {
2371 swap_cgroup_record(ent
, css_id(&memcg
->css
));
2372 mem_cgroup_get(memcg
);
2374 if (swapout
&& memcg
)
2375 css_put(&memcg
->css
);
2379 #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP
2381 * called from swap_entry_free(). remove record in swap_cgroup and
2382 * uncharge "memsw" account.
2384 void mem_cgroup_uncharge_swap(swp_entry_t ent
)
2386 struct mem_cgroup
*memcg
;
2389 if (!do_swap_account
)
2392 id
= swap_cgroup_record(ent
, 0);
2394 memcg
= mem_cgroup_lookup(id
);
2397 * We uncharge this because swap is freed.
2398 * This memcg can be obsolete one. We avoid calling css_tryget
2400 if (!mem_cgroup_is_root(memcg
))
2401 res_counter_uncharge(&memcg
->memsw
, PAGE_SIZE
);
2402 mem_cgroup_swap_statistics(memcg
, false);
2403 mem_cgroup_put(memcg
);
2409 * mem_cgroup_move_swap_account - move swap charge and swap_cgroup's record.
2410 * @entry: swap entry to be moved
2411 * @from: mem_cgroup which the entry is moved from
2412 * @to: mem_cgroup which the entry is moved to
2413 * @need_fixup: whether we should fixup res_counters and refcounts.
2415 * It succeeds only when the swap_cgroup's record for this entry is the same
2416 * as the mem_cgroup's id of @from.
2418 * Returns 0 on success, -EINVAL on failure.
2420 * The caller must have charged to @to, IOW, called res_counter_charge() about
2421 * both res and memsw, and called css_get().
2423 static int mem_cgroup_move_swap_account(swp_entry_t entry
,
2424 struct mem_cgroup
*from
, struct mem_cgroup
*to
, bool need_fixup
)
2426 unsigned short old_id
, new_id
;
2428 old_id
= css_id(&from
->css
);
2429 new_id
= css_id(&to
->css
);
2431 if (swap_cgroup_cmpxchg(entry
, old_id
, new_id
) == old_id
) {
2432 mem_cgroup_swap_statistics(from
, false);
2433 mem_cgroup_swap_statistics(to
, true);
2435 * This function is only called from task migration context now.
2436 * It postpones res_counter and refcount handling till the end
2437 * of task migration(mem_cgroup_clear_mc()) for performance
2438 * improvement. But we cannot postpone mem_cgroup_get(to)
2439 * because if the process that has been moved to @to does
2440 * swap-in, the refcount of @to might be decreased to 0.
2444 if (!mem_cgroup_is_root(from
))
2445 res_counter_uncharge(&from
->memsw
, PAGE_SIZE
);
2446 mem_cgroup_put(from
);
2448 * we charged both to->res and to->memsw, so we should
2451 if (!mem_cgroup_is_root(to
))
2452 res_counter_uncharge(&to
->res
, PAGE_SIZE
);
2460 static inline int mem_cgroup_move_swap_account(swp_entry_t entry
,
2461 struct mem_cgroup
*from
, struct mem_cgroup
*to
, bool need_fixup
)
2468 * Before starting migration, account PAGE_SIZE to mem_cgroup that the old
2471 int mem_cgroup_prepare_migration(struct page
*page
, struct mem_cgroup
**ptr
)
2473 struct page_cgroup
*pc
;
2474 struct mem_cgroup
*mem
= NULL
;
2477 if (mem_cgroup_disabled())
2480 pc
= lookup_page_cgroup(page
);
2481 lock_page_cgroup(pc
);
2482 if (PageCgroupUsed(pc
)) {
2483 mem
= pc
->mem_cgroup
;
2486 unlock_page_cgroup(pc
);
2490 ret
= __mem_cgroup_try_charge(NULL
, GFP_KERNEL
, ptr
, false);
2496 /* remove redundant charge if migration failed*/
2497 void mem_cgroup_end_migration(struct mem_cgroup
*mem
,
2498 struct page
*oldpage
, struct page
*newpage
)
2500 struct page
*target
, *unused
;
2501 struct page_cgroup
*pc
;
2502 enum charge_type ctype
;
2506 cgroup_exclude_rmdir(&mem
->css
);
2507 /* at migration success, oldpage->mapping is NULL. */
2508 if (oldpage
->mapping
) {
2516 if (PageAnon(target
))
2517 ctype
= MEM_CGROUP_CHARGE_TYPE_MAPPED
;
2518 else if (page_is_file_cache(target
))
2519 ctype
= MEM_CGROUP_CHARGE_TYPE_CACHE
;
2521 ctype
= MEM_CGROUP_CHARGE_TYPE_SHMEM
;
2523 /* unused page is not on radix-tree now. */
2525 __mem_cgroup_uncharge_common(unused
, ctype
);
2527 pc
= lookup_page_cgroup(target
);
2529 * __mem_cgroup_commit_charge() check PCG_USED bit of page_cgroup.
2530 * So, double-counting is effectively avoided.
2532 __mem_cgroup_commit_charge(mem
, pc
, ctype
);
2535 * Both of oldpage and newpage are still under lock_page().
2536 * Then, we don't have to care about race in radix-tree.
2537 * But we have to be careful that this page is unmapped or not.
2539 * There is a case for !page_mapped(). At the start of
2540 * migration, oldpage was mapped. But now, it's zapped.
2541 * But we know *target* page is not freed/reused under us.
2542 * mem_cgroup_uncharge_page() does all necessary checks.
2544 if (ctype
== MEM_CGROUP_CHARGE_TYPE_MAPPED
)
2545 mem_cgroup_uncharge_page(target
);
2547 * At migration, we may charge account against cgroup which has no tasks
2548 * So, rmdir()->pre_destroy() can be called while we do this charge.
2549 * In that case, we need to call pre_destroy() again. check it here.
2551 cgroup_release_and_wakeup_rmdir(&mem
->css
);
2555 * A call to try to shrink memory usage on charge failure at shmem's swapin.
2556 * Calling hierarchical_reclaim is not enough because we should update
2557 * last_oom_jiffies to prevent pagefault_out_of_memory from invoking global OOM.
2558 * Moreover considering hierarchy, we should reclaim from the mem_over_limit,
2559 * not from the memcg which this page would be charged to.
2560 * try_charge_swapin does all of these works properly.
2562 int mem_cgroup_shmem_charge_fallback(struct page
*page
,
2563 struct mm_struct
*mm
,
2566 struct mem_cgroup
*mem
= NULL
;
2569 if (mem_cgroup_disabled())
2572 ret
= mem_cgroup_try_charge_swapin(mm
, page
, gfp_mask
, &mem
);
2574 mem_cgroup_cancel_charge_swapin(mem
); /* it does !mem check */
2579 static DEFINE_MUTEX(set_limit_mutex
);
2581 static int mem_cgroup_resize_limit(struct mem_cgroup
*memcg
,
2582 unsigned long long val
)
2585 u64 memswlimit
, memlimit
;
2587 int children
= mem_cgroup_count_children(memcg
);
2588 u64 curusage
, oldusage
;
2592 * For keeping hierarchical_reclaim simple, how long we should retry
2593 * is depends on callers. We set our retry-count to be function
2594 * of # of children which we should visit in this loop.
2596 retry_count
= MEM_CGROUP_RECLAIM_RETRIES
* children
;
2598 oldusage
= res_counter_read_u64(&memcg
->res
, RES_USAGE
);
2601 while (retry_count
) {
2602 if (signal_pending(current
)) {
2607 * Rather than hide all in some function, I do this in
2608 * open coded manner. You see what this really does.
2609 * We have to guarantee mem->res.limit < mem->memsw.limit.
2611 mutex_lock(&set_limit_mutex
);
2612 memswlimit
= res_counter_read_u64(&memcg
->memsw
, RES_LIMIT
);
2613 if (memswlimit
< val
) {
2615 mutex_unlock(&set_limit_mutex
);
2619 memlimit
= res_counter_read_u64(&memcg
->res
, RES_LIMIT
);
2623 ret
= res_counter_set_limit(&memcg
->res
, val
);
2625 if (memswlimit
== val
)
2626 memcg
->memsw_is_minimum
= true;
2628 memcg
->memsw_is_minimum
= false;
2630 mutex_unlock(&set_limit_mutex
);
2635 mem_cgroup_hierarchical_reclaim(memcg
, NULL
, GFP_KERNEL
,
2636 MEM_CGROUP_RECLAIM_SHRINK
);
2637 curusage
= res_counter_read_u64(&memcg
->res
, RES_USAGE
);
2638 /* Usage is reduced ? */
2639 if (curusage
>= oldusage
)
2642 oldusage
= curusage
;
2644 if (!ret
&& enlarge
)
2645 memcg_oom_recover(memcg
);
2650 static int mem_cgroup_resize_memsw_limit(struct mem_cgroup
*memcg
,
2651 unsigned long long val
)
2654 u64 memlimit
, memswlimit
, oldusage
, curusage
;
2655 int children
= mem_cgroup_count_children(memcg
);
2659 /* see mem_cgroup_resize_res_limit */
2660 retry_count
= children
* MEM_CGROUP_RECLAIM_RETRIES
;
2661 oldusage
= res_counter_read_u64(&memcg
->memsw
, RES_USAGE
);
2662 while (retry_count
) {
2663 if (signal_pending(current
)) {
2668 * Rather than hide all in some function, I do this in
2669 * open coded manner. You see what this really does.
2670 * We have to guarantee mem->res.limit < mem->memsw.limit.
2672 mutex_lock(&set_limit_mutex
);
2673 memlimit
= res_counter_read_u64(&memcg
->res
, RES_LIMIT
);
2674 if (memlimit
> val
) {
2676 mutex_unlock(&set_limit_mutex
);
2679 memswlimit
= res_counter_read_u64(&memcg
->memsw
, RES_LIMIT
);
2680 if (memswlimit
< val
)
2682 ret
= res_counter_set_limit(&memcg
->memsw
, val
);
2684 if (memlimit
== val
)
2685 memcg
->memsw_is_minimum
= true;
2687 memcg
->memsw_is_minimum
= false;
2689 mutex_unlock(&set_limit_mutex
);
2694 mem_cgroup_hierarchical_reclaim(memcg
, NULL
, GFP_KERNEL
,
2695 MEM_CGROUP_RECLAIM_NOSWAP
|
2696 MEM_CGROUP_RECLAIM_SHRINK
);
2697 curusage
= res_counter_read_u64(&memcg
->memsw
, RES_USAGE
);
2698 /* Usage is reduced ? */
2699 if (curusage
>= oldusage
)
2702 oldusage
= curusage
;
2704 if (!ret
&& enlarge
)
2705 memcg_oom_recover(memcg
);
2709 unsigned long mem_cgroup_soft_limit_reclaim(struct zone
*zone
, int order
,
2710 gfp_t gfp_mask
, int nid
,
2713 unsigned long nr_reclaimed
= 0;
2714 struct mem_cgroup_per_zone
*mz
, *next_mz
= NULL
;
2715 unsigned long reclaimed
;
2717 struct mem_cgroup_tree_per_zone
*mctz
;
2718 unsigned long long excess
;
2723 mctz
= soft_limit_tree_node_zone(nid
, zid
);
2725 * This loop can run a while, specially if mem_cgroup's continuously
2726 * keep exceeding their soft limit and putting the system under
2733 mz
= mem_cgroup_largest_soft_limit_node(mctz
);
2737 reclaimed
= mem_cgroup_hierarchical_reclaim(mz
->mem
, zone
,
2739 MEM_CGROUP_RECLAIM_SOFT
);
2740 nr_reclaimed
+= reclaimed
;
2741 spin_lock(&mctz
->lock
);
2744 * If we failed to reclaim anything from this memory cgroup
2745 * it is time to move on to the next cgroup
2751 * Loop until we find yet another one.
2753 * By the time we get the soft_limit lock
2754 * again, someone might have aded the
2755 * group back on the RB tree. Iterate to
2756 * make sure we get a different mem.
2757 * mem_cgroup_largest_soft_limit_node returns
2758 * NULL if no other cgroup is present on
2762 __mem_cgroup_largest_soft_limit_node(mctz
);
2763 if (next_mz
== mz
) {
2764 css_put(&next_mz
->mem
->css
);
2766 } else /* next_mz == NULL or other memcg */
2770 __mem_cgroup_remove_exceeded(mz
->mem
, mz
, mctz
);
2771 excess
= res_counter_soft_limit_excess(&mz
->mem
->res
);
2773 * One school of thought says that we should not add
2774 * back the node to the tree if reclaim returns 0.
2775 * But our reclaim could return 0, simply because due
2776 * to priority we are exposing a smaller subset of
2777 * memory to reclaim from. Consider this as a longer
2780 /* If excess == 0, no tree ops */
2781 __mem_cgroup_insert_exceeded(mz
->mem
, mz
, mctz
, excess
);
2782 spin_unlock(&mctz
->lock
);
2783 css_put(&mz
->mem
->css
);
2786 * Could not reclaim anything and there are no more
2787 * mem cgroups to try or we seem to be looping without
2788 * reclaiming anything.
2790 if (!nr_reclaimed
&&
2792 loop
> MEM_CGROUP_MAX_SOFT_LIMIT_RECLAIM_LOOPS
))
2794 } while (!nr_reclaimed
);
2796 css_put(&next_mz
->mem
->css
);
2797 return nr_reclaimed
;
2801 * This routine traverse page_cgroup in given list and drop them all.
2802 * *And* this routine doesn't reclaim page itself, just removes page_cgroup.
2804 static int mem_cgroup_force_empty_list(struct mem_cgroup
*mem
,
2805 int node
, int zid
, enum lru_list lru
)
2808 struct mem_cgroup_per_zone
*mz
;
2809 struct page_cgroup
*pc
, *busy
;
2810 unsigned long flags
, loop
;
2811 struct list_head
*list
;
2814 zone
= &NODE_DATA(node
)->node_zones
[zid
];
2815 mz
= mem_cgroup_zoneinfo(mem
, node
, zid
);
2816 list
= &mz
->lists
[lru
];
2818 loop
= MEM_CGROUP_ZSTAT(mz
, lru
);
2819 /* give some margin against EBUSY etc...*/
2824 spin_lock_irqsave(&zone
->lru_lock
, flags
);
2825 if (list_empty(list
)) {
2826 spin_unlock_irqrestore(&zone
->lru_lock
, flags
);
2829 pc
= list_entry(list
->prev
, struct page_cgroup
, lru
);
2831 list_move(&pc
->lru
, list
);
2833 spin_unlock_irqrestore(&zone
->lru_lock
, flags
);
2836 spin_unlock_irqrestore(&zone
->lru_lock
, flags
);
2838 ret
= mem_cgroup_move_parent(pc
, mem
, GFP_KERNEL
);
2842 if (ret
== -EBUSY
|| ret
== -EINVAL
) {
2843 /* found lock contention or "pc" is obsolete. */
2850 if (!ret
&& !list_empty(list
))
2856 * make mem_cgroup's charge to be 0 if there is no task.
2857 * This enables deleting this mem_cgroup.
2859 static int mem_cgroup_force_empty(struct mem_cgroup
*mem
, bool free_all
)
2862 int node
, zid
, shrink
;
2863 int nr_retries
= MEM_CGROUP_RECLAIM_RETRIES
;
2864 struct cgroup
*cgrp
= mem
->css
.cgroup
;
2869 /* should free all ? */
2875 if (cgroup_task_count(cgrp
) || !list_empty(&cgrp
->children
))
2878 if (signal_pending(current
))
2880 /* This is for making all *used* pages to be on LRU. */
2881 lru_add_drain_all();
2882 drain_all_stock_sync();
2884 for_each_node_state(node
, N_HIGH_MEMORY
) {
2885 for (zid
= 0; !ret
&& zid
< MAX_NR_ZONES
; zid
++) {
2888 ret
= mem_cgroup_force_empty_list(mem
,
2897 memcg_oom_recover(mem
);
2898 /* it seems parent cgroup doesn't have enough mem */
2902 /* "ret" should also be checked to ensure all lists are empty. */
2903 } while (mem
->res
.usage
> 0 || ret
);
2909 /* returns EBUSY if there is a task or if we come here twice. */
2910 if (cgroup_task_count(cgrp
) || !list_empty(&cgrp
->children
) || shrink
) {
2914 /* we call try-to-free pages for make this cgroup empty */
2915 lru_add_drain_all();
2916 /* try to free all pages in this cgroup */
2918 while (nr_retries
&& mem
->res
.usage
> 0) {
2921 if (signal_pending(current
)) {
2925 progress
= try_to_free_mem_cgroup_pages(mem
, GFP_KERNEL
,
2926 false, get_swappiness(mem
));
2929 /* maybe some writeback is necessary */
2930 congestion_wait(BLK_RW_ASYNC
, HZ
/10);
2935 /* try move_account...there may be some *locked* pages. */
2939 int mem_cgroup_force_empty_write(struct cgroup
*cont
, unsigned int event
)
2941 return mem_cgroup_force_empty(mem_cgroup_from_cont(cont
), true);
2945 static u64
mem_cgroup_hierarchy_read(struct cgroup
*cont
, struct cftype
*cft
)
2947 return mem_cgroup_from_cont(cont
)->use_hierarchy
;
2950 static int mem_cgroup_hierarchy_write(struct cgroup
*cont
, struct cftype
*cft
,
2954 struct mem_cgroup
*mem
= mem_cgroup_from_cont(cont
);
2955 struct cgroup
*parent
= cont
->parent
;
2956 struct mem_cgroup
*parent_mem
= NULL
;
2959 parent_mem
= mem_cgroup_from_cont(parent
);
2963 * If parent's use_hierarchy is set, we can't make any modifications
2964 * in the child subtrees. If it is unset, then the change can
2965 * occur, provided the current cgroup has no children.
2967 * For the root cgroup, parent_mem is NULL, we allow value to be
2968 * set if there are no children.
2970 if ((!parent_mem
|| !parent_mem
->use_hierarchy
) &&
2971 (val
== 1 || val
== 0)) {
2972 if (list_empty(&cont
->children
))
2973 mem
->use_hierarchy
= val
;
2983 struct mem_cgroup_idx_data
{
2985 enum mem_cgroup_stat_index idx
;
2989 mem_cgroup_get_idx_stat(struct mem_cgroup
*mem
, void *data
)
2991 struct mem_cgroup_idx_data
*d
= data
;
2992 d
->val
+= mem_cgroup_read_stat(mem
, d
->idx
);
2997 mem_cgroup_get_recursive_idx_stat(struct mem_cgroup
*mem
,
2998 enum mem_cgroup_stat_index idx
, s64
*val
)
3000 struct mem_cgroup_idx_data d
;
3003 mem_cgroup_walk_tree(mem
, &d
, mem_cgroup_get_idx_stat
);
3007 static inline u64
mem_cgroup_usage(struct mem_cgroup
*mem
, bool swap
)
3011 if (!mem_cgroup_is_root(mem
)) {
3013 return res_counter_read_u64(&mem
->res
, RES_USAGE
);
3015 return res_counter_read_u64(&mem
->memsw
, RES_USAGE
);
3018 mem_cgroup_get_recursive_idx_stat(mem
, MEM_CGROUP_STAT_CACHE
, &idx_val
);
3020 mem_cgroup_get_recursive_idx_stat(mem
, MEM_CGROUP_STAT_RSS
, &idx_val
);
3024 mem_cgroup_get_recursive_idx_stat(mem
,
3025 MEM_CGROUP_STAT_SWAPOUT
, &idx_val
);
3029 return val
<< PAGE_SHIFT
;
3032 static u64
mem_cgroup_read(struct cgroup
*cont
, struct cftype
*cft
)
3034 struct mem_cgroup
*mem
= mem_cgroup_from_cont(cont
);
3038 type
= MEMFILE_TYPE(cft
->private);
3039 name
= MEMFILE_ATTR(cft
->private);
3042 if (name
== RES_USAGE
)
3043 val
= mem_cgroup_usage(mem
, false);
3045 val
= res_counter_read_u64(&mem
->res
, name
);
3048 if (name
== RES_USAGE
)
3049 val
= mem_cgroup_usage(mem
, true);
3051 val
= res_counter_read_u64(&mem
->memsw
, name
);
3060 * The user of this function is...
3063 static int mem_cgroup_write(struct cgroup
*cont
, struct cftype
*cft
,
3066 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cont
);
3068 unsigned long long val
;
3071 type
= MEMFILE_TYPE(cft
->private);
3072 name
= MEMFILE_ATTR(cft
->private);
3075 if (mem_cgroup_is_root(memcg
)) { /* Can't set limit on root */
3079 /* This function does all necessary parse...reuse it */
3080 ret
= res_counter_memparse_write_strategy(buffer
, &val
);
3084 ret
= mem_cgroup_resize_limit(memcg
, val
);
3086 ret
= mem_cgroup_resize_memsw_limit(memcg
, val
);
3088 case RES_SOFT_LIMIT
:
3089 ret
= res_counter_memparse_write_strategy(buffer
, &val
);
3093 * For memsw, soft limits are hard to implement in terms
3094 * of semantics, for now, we support soft limits for
3095 * control without swap
3098 ret
= res_counter_set_soft_limit(&memcg
->res
, val
);
3103 ret
= -EINVAL
; /* should be BUG() ? */
3109 static void memcg_get_hierarchical_limit(struct mem_cgroup
*memcg
,
3110 unsigned long long *mem_limit
, unsigned long long *memsw_limit
)
3112 struct cgroup
*cgroup
;
3113 unsigned long long min_limit
, min_memsw_limit
, tmp
;
3115 min_limit
= res_counter_read_u64(&memcg
->res
, RES_LIMIT
);
3116 min_memsw_limit
= res_counter_read_u64(&memcg
->memsw
, RES_LIMIT
);
3117 cgroup
= memcg
->css
.cgroup
;
3118 if (!memcg
->use_hierarchy
)
3121 while (cgroup
->parent
) {
3122 cgroup
= cgroup
->parent
;
3123 memcg
= mem_cgroup_from_cont(cgroup
);
3124 if (!memcg
->use_hierarchy
)
3126 tmp
= res_counter_read_u64(&memcg
->res
, RES_LIMIT
);
3127 min_limit
= min(min_limit
, tmp
);
3128 tmp
= res_counter_read_u64(&memcg
->memsw
, RES_LIMIT
);
3129 min_memsw_limit
= min(min_memsw_limit
, tmp
);
3132 *mem_limit
= min_limit
;
3133 *memsw_limit
= min_memsw_limit
;
3137 static int mem_cgroup_reset(struct cgroup
*cont
, unsigned int event
)
3139 struct mem_cgroup
*mem
;
3142 mem
= mem_cgroup_from_cont(cont
);
3143 type
= MEMFILE_TYPE(event
);
3144 name
= MEMFILE_ATTR(event
);
3148 res_counter_reset_max(&mem
->res
);
3150 res_counter_reset_max(&mem
->memsw
);
3154 res_counter_reset_failcnt(&mem
->res
);
3156 res_counter_reset_failcnt(&mem
->memsw
);
3163 static u64
mem_cgroup_move_charge_read(struct cgroup
*cgrp
,
3166 return mem_cgroup_from_cont(cgrp
)->move_charge_at_immigrate
;
3170 static int mem_cgroup_move_charge_write(struct cgroup
*cgrp
,
3171 struct cftype
*cft
, u64 val
)
3173 struct mem_cgroup
*mem
= mem_cgroup_from_cont(cgrp
);
3175 if (val
>= (1 << NR_MOVE_TYPE
))
3178 * We check this value several times in both in can_attach() and
3179 * attach(), so we need cgroup lock to prevent this value from being
3183 mem
->move_charge_at_immigrate
= val
;
3189 static int mem_cgroup_move_charge_write(struct cgroup
*cgrp
,
3190 struct cftype
*cft
, u64 val
)
3197 /* For read statistics */
3213 struct mcs_total_stat
{
3214 s64 stat
[NR_MCS_STAT
];
3220 } memcg_stat_strings
[NR_MCS_STAT
] = {
3221 {"cache", "total_cache"},
3222 {"rss", "total_rss"},
3223 {"mapped_file", "total_mapped_file"},
3224 {"pgpgin", "total_pgpgin"},
3225 {"pgpgout", "total_pgpgout"},
3226 {"swap", "total_swap"},
3227 {"inactive_anon", "total_inactive_anon"},
3228 {"active_anon", "total_active_anon"},
3229 {"inactive_file", "total_inactive_file"},
3230 {"active_file", "total_active_file"},
3231 {"unevictable", "total_unevictable"}
3235 static int mem_cgroup_get_local_stat(struct mem_cgroup
*mem
, void *data
)
3237 struct mcs_total_stat
*s
= data
;
3241 val
= mem_cgroup_read_stat(mem
, MEM_CGROUP_STAT_CACHE
);
3242 s
->stat
[MCS_CACHE
] += val
* PAGE_SIZE
;
3243 val
= mem_cgroup_read_stat(mem
, MEM_CGROUP_STAT_RSS
);
3244 s
->stat
[MCS_RSS
] += val
* PAGE_SIZE
;
3245 val
= mem_cgroup_read_stat(mem
, MEM_CGROUP_STAT_FILE_MAPPED
);
3246 s
->stat
[MCS_FILE_MAPPED
] += val
* PAGE_SIZE
;
3247 val
= mem_cgroup_read_stat(mem
, MEM_CGROUP_STAT_PGPGIN_COUNT
);
3248 s
->stat
[MCS_PGPGIN
] += val
;
3249 val
= mem_cgroup_read_stat(mem
, MEM_CGROUP_STAT_PGPGOUT_COUNT
);
3250 s
->stat
[MCS_PGPGOUT
] += val
;
3251 if (do_swap_account
) {
3252 val
= mem_cgroup_read_stat(mem
, MEM_CGROUP_STAT_SWAPOUT
);
3253 s
->stat
[MCS_SWAP
] += val
* PAGE_SIZE
;
3257 val
= mem_cgroup_get_local_zonestat(mem
, LRU_INACTIVE_ANON
);
3258 s
->stat
[MCS_INACTIVE_ANON
] += val
* PAGE_SIZE
;
3259 val
= mem_cgroup_get_local_zonestat(mem
, LRU_ACTIVE_ANON
);
3260 s
->stat
[MCS_ACTIVE_ANON
] += val
* PAGE_SIZE
;
3261 val
= mem_cgroup_get_local_zonestat(mem
, LRU_INACTIVE_FILE
);
3262 s
->stat
[MCS_INACTIVE_FILE
] += val
* PAGE_SIZE
;
3263 val
= mem_cgroup_get_local_zonestat(mem
, LRU_ACTIVE_FILE
);
3264 s
->stat
[MCS_ACTIVE_FILE
] += val
* PAGE_SIZE
;
3265 val
= mem_cgroup_get_local_zonestat(mem
, LRU_UNEVICTABLE
);
3266 s
->stat
[MCS_UNEVICTABLE
] += val
* PAGE_SIZE
;
3271 mem_cgroup_get_total_stat(struct mem_cgroup
*mem
, struct mcs_total_stat
*s
)
3273 mem_cgroup_walk_tree(mem
, s
, mem_cgroup_get_local_stat
);
3276 static int mem_control_stat_show(struct cgroup
*cont
, struct cftype
*cft
,
3277 struct cgroup_map_cb
*cb
)
3279 struct mem_cgroup
*mem_cont
= mem_cgroup_from_cont(cont
);
3280 struct mcs_total_stat mystat
;
3283 memset(&mystat
, 0, sizeof(mystat
));
3284 mem_cgroup_get_local_stat(mem_cont
, &mystat
);
3286 for (i
= 0; i
< NR_MCS_STAT
; i
++) {
3287 if (i
== MCS_SWAP
&& !do_swap_account
)
3289 cb
->fill(cb
, memcg_stat_strings
[i
].local_name
, mystat
.stat
[i
]);
3292 /* Hierarchical information */
3294 unsigned long long limit
, memsw_limit
;
3295 memcg_get_hierarchical_limit(mem_cont
, &limit
, &memsw_limit
);
3296 cb
->fill(cb
, "hierarchical_memory_limit", limit
);
3297 if (do_swap_account
)
3298 cb
->fill(cb
, "hierarchical_memsw_limit", memsw_limit
);
3301 memset(&mystat
, 0, sizeof(mystat
));
3302 mem_cgroup_get_total_stat(mem_cont
, &mystat
);
3303 for (i
= 0; i
< NR_MCS_STAT
; i
++) {
3304 if (i
== MCS_SWAP
&& !do_swap_account
)
3306 cb
->fill(cb
, memcg_stat_strings
[i
].total_name
, mystat
.stat
[i
]);
3309 #ifdef CONFIG_DEBUG_VM
3310 cb
->fill(cb
, "inactive_ratio", calc_inactive_ratio(mem_cont
, NULL
));
3314 struct mem_cgroup_per_zone
*mz
;
3315 unsigned long recent_rotated
[2] = {0, 0};
3316 unsigned long recent_scanned
[2] = {0, 0};
3318 for_each_online_node(nid
)
3319 for (zid
= 0; zid
< MAX_NR_ZONES
; zid
++) {
3320 mz
= mem_cgroup_zoneinfo(mem_cont
, nid
, zid
);
3322 recent_rotated
[0] +=
3323 mz
->reclaim_stat
.recent_rotated
[0];
3324 recent_rotated
[1] +=
3325 mz
->reclaim_stat
.recent_rotated
[1];
3326 recent_scanned
[0] +=
3327 mz
->reclaim_stat
.recent_scanned
[0];
3328 recent_scanned
[1] +=
3329 mz
->reclaim_stat
.recent_scanned
[1];
3331 cb
->fill(cb
, "recent_rotated_anon", recent_rotated
[0]);
3332 cb
->fill(cb
, "recent_rotated_file", recent_rotated
[1]);
3333 cb
->fill(cb
, "recent_scanned_anon", recent_scanned
[0]);
3334 cb
->fill(cb
, "recent_scanned_file", recent_scanned
[1]);
3341 static u64
mem_cgroup_swappiness_read(struct cgroup
*cgrp
, struct cftype
*cft
)
3343 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cgrp
);
3345 return get_swappiness(memcg
);
3348 static int mem_cgroup_swappiness_write(struct cgroup
*cgrp
, struct cftype
*cft
,
3351 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cgrp
);
3352 struct mem_cgroup
*parent
;
3357 if (cgrp
->parent
== NULL
)
3360 parent
= mem_cgroup_from_cont(cgrp
->parent
);
3364 /* If under hierarchy, only empty-root can set this value */
3365 if ((parent
->use_hierarchy
) ||
3366 (memcg
->use_hierarchy
&& !list_empty(&cgrp
->children
))) {
3371 spin_lock(&memcg
->reclaim_param_lock
);
3372 memcg
->swappiness
= val
;
3373 spin_unlock(&memcg
->reclaim_param_lock
);
3380 static void __mem_cgroup_threshold(struct mem_cgroup
*memcg
, bool swap
)
3382 struct mem_cgroup_threshold_ary
*t
;
3388 t
= rcu_dereference(memcg
->thresholds
);
3390 t
= rcu_dereference(memcg
->memsw_thresholds
);
3395 usage
= mem_cgroup_usage(memcg
, swap
);
3398 * current_threshold points to threshold just below usage.
3399 * If it's not true, a threshold was crossed after last
3400 * call of __mem_cgroup_threshold().
3402 i
= atomic_read(&t
->current_threshold
);
3405 * Iterate backward over array of thresholds starting from
3406 * current_threshold and check if a threshold is crossed.
3407 * If none of thresholds below usage is crossed, we read
3408 * only one element of the array here.
3410 for (; i
>= 0 && unlikely(t
->entries
[i
].threshold
> usage
); i
--)
3411 eventfd_signal(t
->entries
[i
].eventfd
, 1);
3413 /* i = current_threshold + 1 */
3417 * Iterate forward over array of thresholds starting from
3418 * current_threshold+1 and check if a threshold is crossed.
3419 * If none of thresholds above usage is crossed, we read
3420 * only one element of the array here.
3422 for (; i
< t
->size
&& unlikely(t
->entries
[i
].threshold
<= usage
); i
++)
3423 eventfd_signal(t
->entries
[i
].eventfd
, 1);
3425 /* Update current_threshold */
3426 atomic_set(&t
->current_threshold
, i
- 1);
3431 static void mem_cgroup_threshold(struct mem_cgroup
*memcg
)
3433 __mem_cgroup_threshold(memcg
, false);
3434 if (do_swap_account
)
3435 __mem_cgroup_threshold(memcg
, true);
3438 static int compare_thresholds(const void *a
, const void *b
)
3440 const struct mem_cgroup_threshold
*_a
= a
;
3441 const struct mem_cgroup_threshold
*_b
= b
;
3443 return _a
->threshold
- _b
->threshold
;
3446 static int mem_cgroup_oom_notify_cb(struct mem_cgroup
*mem
, void *data
)
3448 struct mem_cgroup_eventfd_list
*ev
;
3450 list_for_each_entry(ev
, &mem
->oom_notify
, list
)
3451 eventfd_signal(ev
->eventfd
, 1);
3455 static void mem_cgroup_oom_notify(struct mem_cgroup
*mem
)
3457 mem_cgroup_walk_tree(mem
, NULL
, mem_cgroup_oom_notify_cb
);
3460 static int mem_cgroup_usage_register_event(struct cgroup
*cgrp
,
3461 struct cftype
*cft
, struct eventfd_ctx
*eventfd
, const char *args
)
3463 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cgrp
);
3464 struct mem_cgroup_threshold_ary
*thresholds
, *thresholds_new
;
3465 int type
= MEMFILE_TYPE(cft
->private);
3466 u64 threshold
, usage
;
3470 ret
= res_counter_memparse_write_strategy(args
, &threshold
);
3474 mutex_lock(&memcg
->thresholds_lock
);
3476 thresholds
= memcg
->thresholds
;
3477 else if (type
== _MEMSWAP
)
3478 thresholds
= memcg
->memsw_thresholds
;
3482 usage
= mem_cgroup_usage(memcg
, type
== _MEMSWAP
);
3484 /* Check if a threshold crossed before adding a new one */
3486 __mem_cgroup_threshold(memcg
, type
== _MEMSWAP
);
3489 size
= thresholds
->size
+ 1;
3493 /* Allocate memory for new array of thresholds */
3494 thresholds_new
= kmalloc(sizeof(*thresholds_new
) +
3495 size
* sizeof(struct mem_cgroup_threshold
),
3497 if (!thresholds_new
) {
3501 thresholds_new
->size
= size
;
3503 /* Copy thresholds (if any) to new array */
3505 memcpy(thresholds_new
->entries
, thresholds
->entries
,
3507 sizeof(struct mem_cgroup_threshold
));
3508 /* Add new threshold */
3509 thresholds_new
->entries
[size
- 1].eventfd
= eventfd
;
3510 thresholds_new
->entries
[size
- 1].threshold
= threshold
;
3512 /* Sort thresholds. Registering of new threshold isn't time-critical */
3513 sort(thresholds_new
->entries
, size
,
3514 sizeof(struct mem_cgroup_threshold
),
3515 compare_thresholds
, NULL
);
3517 /* Find current threshold */
3518 atomic_set(&thresholds_new
->current_threshold
, -1);
3519 for (i
= 0; i
< size
; i
++) {
3520 if (thresholds_new
->entries
[i
].threshold
< usage
) {
3522 * thresholds_new->current_threshold will not be used
3523 * until rcu_assign_pointer(), so it's safe to increment
3526 atomic_inc(&thresholds_new
->current_threshold
);
3531 rcu_assign_pointer(memcg
->thresholds
, thresholds_new
);
3533 rcu_assign_pointer(memcg
->memsw_thresholds
, thresholds_new
);
3535 /* To be sure that nobody uses thresholds before freeing it */
3540 mutex_unlock(&memcg
->thresholds_lock
);
3545 static int mem_cgroup_usage_unregister_event(struct cgroup
*cgrp
,
3546 struct cftype
*cft
, struct eventfd_ctx
*eventfd
)
3548 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cgrp
);
3549 struct mem_cgroup_threshold_ary
*thresholds
, *thresholds_new
;
3550 int type
= MEMFILE_TYPE(cft
->private);
3555 mutex_lock(&memcg
->thresholds_lock
);
3557 thresholds
= memcg
->thresholds
;
3558 else if (type
== _MEMSWAP
)
3559 thresholds
= memcg
->memsw_thresholds
;
3564 * Something went wrong if we trying to unregister a threshold
3565 * if we don't have thresholds
3567 BUG_ON(!thresholds
);
3569 usage
= mem_cgroup_usage(memcg
, type
== _MEMSWAP
);
3571 /* Check if a threshold crossed before removing */
3572 __mem_cgroup_threshold(memcg
, type
== _MEMSWAP
);
3574 /* Calculate new number of threshold */
3575 for (i
= 0; i
< thresholds
->size
; i
++) {
3576 if (thresholds
->entries
[i
].eventfd
!= eventfd
)
3580 /* Set thresholds array to NULL if we don't have thresholds */
3582 thresholds_new
= NULL
;
3586 /* Allocate memory for new array of thresholds */
3587 thresholds_new
= kmalloc(sizeof(*thresholds_new
) +
3588 size
* sizeof(struct mem_cgroup_threshold
),
3590 if (!thresholds_new
) {
3594 thresholds_new
->size
= size
;
3596 /* Copy thresholds and find current threshold */
3597 atomic_set(&thresholds_new
->current_threshold
, -1);
3598 for (i
= 0, j
= 0; i
< thresholds
->size
; i
++) {
3599 if (thresholds
->entries
[i
].eventfd
== eventfd
)
3602 thresholds_new
->entries
[j
] = thresholds
->entries
[i
];
3603 if (thresholds_new
->entries
[j
].threshold
< usage
) {
3605 * thresholds_new->current_threshold will not be used
3606 * until rcu_assign_pointer(), so it's safe to increment
3609 atomic_inc(&thresholds_new
->current_threshold
);
3616 rcu_assign_pointer(memcg
->thresholds
, thresholds_new
);
3618 rcu_assign_pointer(memcg
->memsw_thresholds
, thresholds_new
);
3620 /* To be sure that nobody uses thresholds before freeing it */
3625 mutex_unlock(&memcg
->thresholds_lock
);
3630 static int mem_cgroup_oom_register_event(struct cgroup
*cgrp
,
3631 struct cftype
*cft
, struct eventfd_ctx
*eventfd
, const char *args
)
3633 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cgrp
);
3634 struct mem_cgroup_eventfd_list
*event
;
3635 int type
= MEMFILE_TYPE(cft
->private);
3637 BUG_ON(type
!= _OOM_TYPE
);
3638 event
= kmalloc(sizeof(*event
), GFP_KERNEL
);
3642 mutex_lock(&memcg_oom_mutex
);
3644 event
->eventfd
= eventfd
;
3645 list_add(&event
->list
, &memcg
->oom_notify
);
3647 /* already in OOM ? */
3648 if (atomic_read(&memcg
->oom_lock
))
3649 eventfd_signal(eventfd
, 1);
3650 mutex_unlock(&memcg_oom_mutex
);
3655 static int mem_cgroup_oom_unregister_event(struct cgroup
*cgrp
,
3656 struct cftype
*cft
, struct eventfd_ctx
*eventfd
)
3658 struct mem_cgroup
*mem
= mem_cgroup_from_cont(cgrp
);
3659 struct mem_cgroup_eventfd_list
*ev
, *tmp
;
3660 int type
= MEMFILE_TYPE(cft
->private);
3662 BUG_ON(type
!= _OOM_TYPE
);
3664 mutex_lock(&memcg_oom_mutex
);
3666 list_for_each_entry_safe(ev
, tmp
, &mem
->oom_notify
, list
) {
3667 if (ev
->eventfd
== eventfd
) {
3668 list_del(&ev
->list
);
3673 mutex_unlock(&memcg_oom_mutex
);
3678 static int mem_cgroup_oom_control_read(struct cgroup
*cgrp
,
3679 struct cftype
*cft
, struct cgroup_map_cb
*cb
)
3681 struct mem_cgroup
*mem
= mem_cgroup_from_cont(cgrp
);
3683 cb
->fill(cb
, "oom_kill_disable", mem
->oom_kill_disable
);
3685 if (atomic_read(&mem
->oom_lock
))
3686 cb
->fill(cb
, "under_oom", 1);
3688 cb
->fill(cb
, "under_oom", 0);
3694 static int mem_cgroup_oom_control_write(struct cgroup
*cgrp
,
3695 struct cftype
*cft
, u64 val
)
3697 struct mem_cgroup
*mem
= mem_cgroup_from_cont(cgrp
);
3698 struct mem_cgroup
*parent
;
3700 /* cannot set to root cgroup and only 0 and 1 are allowed */
3701 if (!cgrp
->parent
|| !((val
== 0) || (val
== 1)))
3704 parent
= mem_cgroup_from_cont(cgrp
->parent
);
3707 /* oom-kill-disable is a flag for subhierarchy. */
3708 if ((parent
->use_hierarchy
) ||
3709 (mem
->use_hierarchy
&& !list_empty(&cgrp
->children
))) {
3713 mem
->oom_kill_disable
= val
;
3718 static struct cftype mem_cgroup_files
[] = {
3720 .name
= "usage_in_bytes",
3721 .private = MEMFILE_PRIVATE(_MEM
, RES_USAGE
),
3722 .read_u64
= mem_cgroup_read
,
3723 .register_event
= mem_cgroup_usage_register_event
,
3724 .unregister_event
= mem_cgroup_usage_unregister_event
,
3727 .name
= "max_usage_in_bytes",
3728 .private = MEMFILE_PRIVATE(_MEM
, RES_MAX_USAGE
),
3729 .trigger
= mem_cgroup_reset
,
3730 .read_u64
= mem_cgroup_read
,
3733 .name
= "limit_in_bytes",
3734 .private = MEMFILE_PRIVATE(_MEM
, RES_LIMIT
),
3735 .write_string
= mem_cgroup_write
,
3736 .read_u64
= mem_cgroup_read
,
3739 .name
= "soft_limit_in_bytes",
3740 .private = MEMFILE_PRIVATE(_MEM
, RES_SOFT_LIMIT
),
3741 .write_string
= mem_cgroup_write
,
3742 .read_u64
= mem_cgroup_read
,
3746 .private = MEMFILE_PRIVATE(_MEM
, RES_FAILCNT
),
3747 .trigger
= mem_cgroup_reset
,
3748 .read_u64
= mem_cgroup_read
,
3752 .read_map
= mem_control_stat_show
,
3755 .name
= "force_empty",
3756 .trigger
= mem_cgroup_force_empty_write
,
3759 .name
= "use_hierarchy",
3760 .write_u64
= mem_cgroup_hierarchy_write
,
3761 .read_u64
= mem_cgroup_hierarchy_read
,
3764 .name
= "swappiness",
3765 .read_u64
= mem_cgroup_swappiness_read
,
3766 .write_u64
= mem_cgroup_swappiness_write
,
3769 .name
= "move_charge_at_immigrate",
3770 .read_u64
= mem_cgroup_move_charge_read
,
3771 .write_u64
= mem_cgroup_move_charge_write
,
3774 .name
= "oom_control",
3775 .read_map
= mem_cgroup_oom_control_read
,
3776 .write_u64
= mem_cgroup_oom_control_write
,
3777 .register_event
= mem_cgroup_oom_register_event
,
3778 .unregister_event
= mem_cgroup_oom_unregister_event
,
3779 .private = MEMFILE_PRIVATE(_OOM_TYPE
, OOM_CONTROL
),
3783 #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP
3784 static struct cftype memsw_cgroup_files
[] = {
3786 .name
= "memsw.usage_in_bytes",
3787 .private = MEMFILE_PRIVATE(_MEMSWAP
, RES_USAGE
),
3788 .read_u64
= mem_cgroup_read
,
3789 .register_event
= mem_cgroup_usage_register_event
,
3790 .unregister_event
= mem_cgroup_usage_unregister_event
,
3793 .name
= "memsw.max_usage_in_bytes",
3794 .private = MEMFILE_PRIVATE(_MEMSWAP
, RES_MAX_USAGE
),
3795 .trigger
= mem_cgroup_reset
,
3796 .read_u64
= mem_cgroup_read
,
3799 .name
= "memsw.limit_in_bytes",
3800 .private = MEMFILE_PRIVATE(_MEMSWAP
, RES_LIMIT
),
3801 .write_string
= mem_cgroup_write
,
3802 .read_u64
= mem_cgroup_read
,
3805 .name
= "memsw.failcnt",
3806 .private = MEMFILE_PRIVATE(_MEMSWAP
, RES_FAILCNT
),
3807 .trigger
= mem_cgroup_reset
,
3808 .read_u64
= mem_cgroup_read
,
3812 static int register_memsw_files(struct cgroup
*cont
, struct cgroup_subsys
*ss
)
3814 if (!do_swap_account
)
3816 return cgroup_add_files(cont
, ss
, memsw_cgroup_files
,
3817 ARRAY_SIZE(memsw_cgroup_files
));
3820 static int register_memsw_files(struct cgroup
*cont
, struct cgroup_subsys
*ss
)
3826 static int alloc_mem_cgroup_per_zone_info(struct mem_cgroup
*mem
, int node
)
3828 struct mem_cgroup_per_node
*pn
;
3829 struct mem_cgroup_per_zone
*mz
;
3831 int zone
, tmp
= node
;
3833 * This routine is called against possible nodes.
3834 * But it's BUG to call kmalloc() against offline node.
3836 * TODO: this routine can waste much memory for nodes which will
3837 * never be onlined. It's better to use memory hotplug callback
3840 if (!node_state(node
, N_NORMAL_MEMORY
))
3842 pn
= kmalloc_node(sizeof(*pn
), GFP_KERNEL
, tmp
);
3846 mem
->info
.nodeinfo
[node
] = pn
;
3847 memset(pn
, 0, sizeof(*pn
));
3849 for (zone
= 0; zone
< MAX_NR_ZONES
; zone
++) {
3850 mz
= &pn
->zoneinfo
[zone
];
3852 INIT_LIST_HEAD(&mz
->lists
[l
]);
3853 mz
->usage_in_excess
= 0;
3854 mz
->on_tree
= false;
3860 static void free_mem_cgroup_per_zone_info(struct mem_cgroup
*mem
, int node
)
3862 kfree(mem
->info
.nodeinfo
[node
]);
3865 static struct mem_cgroup
*mem_cgroup_alloc(void)
3867 struct mem_cgroup
*mem
;
3868 int size
= sizeof(struct mem_cgroup
);
3870 /* Can be very big if MAX_NUMNODES is very big */
3871 if (size
< PAGE_SIZE
)
3872 mem
= kmalloc(size
, GFP_KERNEL
);
3874 mem
= vmalloc(size
);
3879 memset(mem
, 0, size
);
3880 mem
->stat
= alloc_percpu(struct mem_cgroup_stat_cpu
);
3882 if (size
< PAGE_SIZE
)
3892 * At destroying mem_cgroup, references from swap_cgroup can remain.
3893 * (scanning all at force_empty is too costly...)
3895 * Instead of clearing all references at force_empty, we remember
3896 * the number of reference from swap_cgroup and free mem_cgroup when
3897 * it goes down to 0.
3899 * Removal of cgroup itself succeeds regardless of refs from swap.
3902 static void __mem_cgroup_free(struct mem_cgroup
*mem
)
3906 mem_cgroup_remove_from_trees(mem
);
3907 free_css_id(&mem_cgroup_subsys
, &mem
->css
);
3909 for_each_node_state(node
, N_POSSIBLE
)
3910 free_mem_cgroup_per_zone_info(mem
, node
);
3912 free_percpu(mem
->stat
);
3913 if (sizeof(struct mem_cgroup
) < PAGE_SIZE
)
3919 static void mem_cgroup_get(struct mem_cgroup
*mem
)
3921 atomic_inc(&mem
->refcnt
);
3924 static void __mem_cgroup_put(struct mem_cgroup
*mem
, int count
)
3926 if (atomic_sub_and_test(count
, &mem
->refcnt
)) {
3927 struct mem_cgroup
*parent
= parent_mem_cgroup(mem
);
3928 __mem_cgroup_free(mem
);
3930 mem_cgroup_put(parent
);
3934 static void mem_cgroup_put(struct mem_cgroup
*mem
)
3936 __mem_cgroup_put(mem
, 1);
3940 * Returns the parent mem_cgroup in memcgroup hierarchy with hierarchy enabled.
3942 static struct mem_cgroup
*parent_mem_cgroup(struct mem_cgroup
*mem
)
3944 if (!mem
->res
.parent
)
3946 return mem_cgroup_from_res_counter(mem
->res
.parent
, res
);
3949 #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP
3950 static void __init
enable_swap_cgroup(void)
3952 if (!mem_cgroup_disabled() && really_do_swap_account
)
3953 do_swap_account
= 1;
3956 static void __init
enable_swap_cgroup(void)
3961 static int mem_cgroup_soft_limit_tree_init(void)
3963 struct mem_cgroup_tree_per_node
*rtpn
;
3964 struct mem_cgroup_tree_per_zone
*rtpz
;
3965 int tmp
, node
, zone
;
3967 for_each_node_state(node
, N_POSSIBLE
) {
3969 if (!node_state(node
, N_NORMAL_MEMORY
))
3971 rtpn
= kzalloc_node(sizeof(*rtpn
), GFP_KERNEL
, tmp
);
3975 soft_limit_tree
.rb_tree_per_node
[node
] = rtpn
;
3977 for (zone
= 0; zone
< MAX_NR_ZONES
; zone
++) {
3978 rtpz
= &rtpn
->rb_tree_per_zone
[zone
];
3979 rtpz
->rb_root
= RB_ROOT
;
3980 spin_lock_init(&rtpz
->lock
);
3986 static struct cgroup_subsys_state
* __ref
3987 mem_cgroup_create(struct cgroup_subsys
*ss
, struct cgroup
*cont
)
3989 struct mem_cgroup
*mem
, *parent
;
3990 long error
= -ENOMEM
;
3993 mem
= mem_cgroup_alloc();
3995 return ERR_PTR(error
);
3997 for_each_node_state(node
, N_POSSIBLE
)
3998 if (alloc_mem_cgroup_per_zone_info(mem
, node
))
4002 if (cont
->parent
== NULL
) {
4004 enable_swap_cgroup();
4006 root_mem_cgroup
= mem
;
4007 if (mem_cgroup_soft_limit_tree_init())
4009 for_each_possible_cpu(cpu
) {
4010 struct memcg_stock_pcp
*stock
=
4011 &per_cpu(memcg_stock
, cpu
);
4012 INIT_WORK(&stock
->work
, drain_local_stock
);
4014 hotcpu_notifier(memcg_stock_cpu_callback
, 0);
4016 parent
= mem_cgroup_from_cont(cont
->parent
);
4017 mem
->use_hierarchy
= parent
->use_hierarchy
;
4018 mem
->oom_kill_disable
= parent
->oom_kill_disable
;
4021 if (parent
&& parent
->use_hierarchy
) {
4022 res_counter_init(&mem
->res
, &parent
->res
);
4023 res_counter_init(&mem
->memsw
, &parent
->memsw
);
4025 * We increment refcnt of the parent to ensure that we can
4026 * safely access it on res_counter_charge/uncharge.
4027 * This refcnt will be decremented when freeing this
4028 * mem_cgroup(see mem_cgroup_put).
4030 mem_cgroup_get(parent
);
4032 res_counter_init(&mem
->res
, NULL
);
4033 res_counter_init(&mem
->memsw
, NULL
);
4035 mem
->last_scanned_child
= 0;
4036 spin_lock_init(&mem
->reclaim_param_lock
);
4037 INIT_LIST_HEAD(&mem
->oom_notify
);
4040 mem
->swappiness
= get_swappiness(parent
);
4041 atomic_set(&mem
->refcnt
, 1);
4042 mem
->move_charge_at_immigrate
= 0;
4043 mutex_init(&mem
->thresholds_lock
);
4046 __mem_cgroup_free(mem
);
4047 root_mem_cgroup
= NULL
;
4048 return ERR_PTR(error
);
4051 static int mem_cgroup_pre_destroy(struct cgroup_subsys
*ss
,
4052 struct cgroup
*cont
)
4054 struct mem_cgroup
*mem
= mem_cgroup_from_cont(cont
);
4056 return mem_cgroup_force_empty(mem
, false);
4059 static void mem_cgroup_destroy(struct cgroup_subsys
*ss
,
4060 struct cgroup
*cont
)
4062 struct mem_cgroup
*mem
= mem_cgroup_from_cont(cont
);
4064 mem_cgroup_put(mem
);
4067 static int mem_cgroup_populate(struct cgroup_subsys
*ss
,
4068 struct cgroup
*cont
)
4072 ret
= cgroup_add_files(cont
, ss
, mem_cgroup_files
,
4073 ARRAY_SIZE(mem_cgroup_files
));
4076 ret
= register_memsw_files(cont
, ss
);
4081 /* Handlers for move charge at task migration. */
4082 #define PRECHARGE_COUNT_AT_ONCE 256
4083 static int mem_cgroup_do_precharge(unsigned long count
)
4086 int batch_count
= PRECHARGE_COUNT_AT_ONCE
;
4087 struct mem_cgroup
*mem
= mc
.to
;
4089 if (mem_cgroup_is_root(mem
)) {
4090 mc
.precharge
+= count
;
4091 /* we don't need css_get for root */
4094 /* try to charge at once */
4096 struct res_counter
*dummy
;
4098 * "mem" cannot be under rmdir() because we've already checked
4099 * by cgroup_lock_live_cgroup() that it is not removed and we
4100 * are still under the same cgroup_mutex. So we can postpone
4103 if (res_counter_charge(&mem
->res
, PAGE_SIZE
* count
, &dummy
))
4105 if (do_swap_account
&& res_counter_charge(&mem
->memsw
,
4106 PAGE_SIZE
* count
, &dummy
)) {
4107 res_counter_uncharge(&mem
->res
, PAGE_SIZE
* count
);
4110 mc
.precharge
+= count
;
4111 VM_BUG_ON(test_bit(CSS_ROOT
, &mem
->css
.flags
));
4112 WARN_ON_ONCE(count
> INT_MAX
);
4113 __css_get(&mem
->css
, (int)count
);
4117 /* fall back to one by one charge */
4119 if (signal_pending(current
)) {
4123 if (!batch_count
--) {
4124 batch_count
= PRECHARGE_COUNT_AT_ONCE
;
4127 ret
= __mem_cgroup_try_charge(NULL
, GFP_KERNEL
, &mem
, false);
4129 /* mem_cgroup_clear_mc() will do uncharge later */
4137 * is_target_pte_for_mc - check a pte whether it is valid for move charge
4138 * @vma: the vma the pte to be checked belongs
4139 * @addr: the address corresponding to the pte to be checked
4140 * @ptent: the pte to be checked
4141 * @target: the pointer the target page or swap ent will be stored(can be NULL)
4144 * 0(MC_TARGET_NONE): if the pte is not a target for move charge.
4145 * 1(MC_TARGET_PAGE): if the page corresponding to this pte is a target for
4146 * move charge. if @target is not NULL, the page is stored in target->page
4147 * with extra refcnt got(Callers should handle it).
4148 * 2(MC_TARGET_SWAP): if the swap entry corresponding to this pte is a
4149 * target for charge migration. if @target is not NULL, the entry is stored
4152 * Called with pte lock held.
4159 enum mc_target_type
{
4160 MC_TARGET_NONE
, /* not used */
4165 static int is_target_pte_for_mc(struct vm_area_struct
*vma
,
4166 unsigned long addr
, pte_t ptent
, union mc_target
*target
)
4168 struct page
*page
= NULL
;
4169 struct page_cgroup
*pc
;
4171 swp_entry_t ent
= { .val
= 0 };
4172 int usage_count
= 0;
4173 bool move_anon
= test_bit(MOVE_CHARGE_TYPE_ANON
,
4174 &mc
.to
->move_charge_at_immigrate
);
4176 if (!pte_present(ptent
)) {
4177 /* TODO: handle swap of shmes/tmpfs */
4178 if (pte_none(ptent
) || pte_file(ptent
))
4180 else if (is_swap_pte(ptent
)) {
4181 ent
= pte_to_swp_entry(ptent
);
4182 if (!move_anon
|| non_swap_entry(ent
))
4184 usage_count
= mem_cgroup_count_swap_user(ent
, &page
);
4187 page
= vm_normal_page(vma
, addr
, ptent
);
4188 if (!page
|| !page_mapped(page
))
4191 * TODO: We don't move charges of file(including shmem/tmpfs)
4194 if (!move_anon
|| !PageAnon(page
))
4196 if (!get_page_unless_zero(page
))
4198 usage_count
= page_mapcount(page
);
4200 if (usage_count
> 1) {
4202 * TODO: We don't move charges of shared(used by multiple
4203 * processes) pages for now.
4210 pc
= lookup_page_cgroup(page
);
4212 * Do only loose check w/o page_cgroup lock.
4213 * mem_cgroup_move_account() checks the pc is valid or not under
4216 if (PageCgroupUsed(pc
) && pc
->mem_cgroup
== mc
.from
) {
4217 ret
= MC_TARGET_PAGE
;
4219 target
->page
= page
;
4221 if (!ret
|| !target
)
4225 if (ent
.val
&& do_swap_account
&& !ret
&&
4226 css_id(&mc
.from
->css
) == lookup_swap_cgroup(ent
)) {
4227 ret
= MC_TARGET_SWAP
;
4234 static int mem_cgroup_count_precharge_pte_range(pmd_t
*pmd
,
4235 unsigned long addr
, unsigned long end
,
4236 struct mm_walk
*walk
)
4238 struct vm_area_struct
*vma
= walk
->private;
4242 pte
= pte_offset_map_lock(vma
->vm_mm
, pmd
, addr
, &ptl
);
4243 for (; addr
!= end
; pte
++, addr
+= PAGE_SIZE
)
4244 if (is_target_pte_for_mc(vma
, addr
, *pte
, NULL
))
4245 mc
.precharge
++; /* increment precharge temporarily */
4246 pte_unmap_unlock(pte
- 1, ptl
);
4252 static unsigned long mem_cgroup_count_precharge(struct mm_struct
*mm
)
4254 unsigned long precharge
;
4255 struct vm_area_struct
*vma
;
4257 down_read(&mm
->mmap_sem
);
4258 for (vma
= mm
->mmap
; vma
; vma
= vma
->vm_next
) {
4259 struct mm_walk mem_cgroup_count_precharge_walk
= {
4260 .pmd_entry
= mem_cgroup_count_precharge_pte_range
,
4264 if (is_vm_hugetlb_page(vma
))
4266 /* TODO: We don't move charges of shmem/tmpfs pages for now. */
4267 if (vma
->vm_flags
& VM_SHARED
)
4269 walk_page_range(vma
->vm_start
, vma
->vm_end
,
4270 &mem_cgroup_count_precharge_walk
);
4272 up_read(&mm
->mmap_sem
);
4274 precharge
= mc
.precharge
;
4280 static int mem_cgroup_precharge_mc(struct mm_struct
*mm
)
4282 return mem_cgroup_do_precharge(mem_cgroup_count_precharge(mm
));
4285 static void mem_cgroup_clear_mc(void)
4287 /* we must uncharge all the leftover precharges from mc.to */
4289 __mem_cgroup_cancel_charge(mc
.to
, mc
.precharge
);
4291 memcg_oom_recover(mc
.to
);
4294 * we didn't uncharge from mc.from at mem_cgroup_move_account(), so
4295 * we must uncharge here.
4297 if (mc
.moved_charge
) {
4298 __mem_cgroup_cancel_charge(mc
.from
, mc
.moved_charge
);
4299 mc
.moved_charge
= 0;
4300 memcg_oom_recover(mc
.from
);
4302 /* we must fixup refcnts and charges */
4303 if (mc
.moved_swap
) {
4304 WARN_ON_ONCE(mc
.moved_swap
> INT_MAX
);
4305 /* uncharge swap account from the old cgroup */
4306 if (!mem_cgroup_is_root(mc
.from
))
4307 res_counter_uncharge(&mc
.from
->memsw
,
4308 PAGE_SIZE
* mc
.moved_swap
);
4309 __mem_cgroup_put(mc
.from
, mc
.moved_swap
);
4311 if (!mem_cgroup_is_root(mc
.to
)) {
4313 * we charged both to->res and to->memsw, so we should
4316 res_counter_uncharge(&mc
.to
->res
,
4317 PAGE_SIZE
* mc
.moved_swap
);
4318 VM_BUG_ON(test_bit(CSS_ROOT
, &mc
.to
->css
.flags
));
4319 __css_put(&mc
.to
->css
, mc
.moved_swap
);
4321 /* we've already done mem_cgroup_get(mc.to) */
4327 mc
.moving_task
= NULL
;
4328 wake_up_all(&mc
.waitq
);
4331 static int mem_cgroup_can_attach(struct cgroup_subsys
*ss
,
4332 struct cgroup
*cgroup
,
4333 struct task_struct
*p
,
4337 struct mem_cgroup
*mem
= mem_cgroup_from_cont(cgroup
);
4339 if (mem
->move_charge_at_immigrate
) {
4340 struct mm_struct
*mm
;
4341 struct mem_cgroup
*from
= mem_cgroup_from_task(p
);
4343 VM_BUG_ON(from
== mem
);
4345 mm
= get_task_mm(p
);
4348 /* We move charges only when we move a owner of the mm */
4349 if (mm
->owner
== p
) {
4352 VM_BUG_ON(mc
.precharge
);
4353 VM_BUG_ON(mc
.moved_charge
);
4354 VM_BUG_ON(mc
.moved_swap
);
4355 VM_BUG_ON(mc
.moving_task
);
4359 mc
.moved_charge
= 0;
4361 mc
.moving_task
= current
;
4363 ret
= mem_cgroup_precharge_mc(mm
);
4365 mem_cgroup_clear_mc();
4372 static void mem_cgroup_cancel_attach(struct cgroup_subsys
*ss
,
4373 struct cgroup
*cgroup
,
4374 struct task_struct
*p
,
4377 mem_cgroup_clear_mc();
4380 static int mem_cgroup_move_charge_pte_range(pmd_t
*pmd
,
4381 unsigned long addr
, unsigned long end
,
4382 struct mm_walk
*walk
)
4385 struct vm_area_struct
*vma
= walk
->private;
4390 pte
= pte_offset_map_lock(vma
->vm_mm
, pmd
, addr
, &ptl
);
4391 for (; addr
!= end
; addr
+= PAGE_SIZE
) {
4392 pte_t ptent
= *(pte
++);
4393 union mc_target target
;
4396 struct page_cgroup
*pc
;
4402 type
= is_target_pte_for_mc(vma
, addr
, ptent
, &target
);
4404 case MC_TARGET_PAGE
:
4406 if (isolate_lru_page(page
))
4408 pc
= lookup_page_cgroup(page
);
4409 if (!mem_cgroup_move_account(pc
,
4410 mc
.from
, mc
.to
, false)) {
4412 /* we uncharge from mc.from later. */
4415 putback_lru_page(page
);
4416 put
: /* is_target_pte_for_mc() gets the page */
4419 case MC_TARGET_SWAP
:
4421 if (!mem_cgroup_move_swap_account(ent
,
4422 mc
.from
, mc
.to
, false)) {
4424 /* we fixup refcnts and charges later. */
4432 pte_unmap_unlock(pte
- 1, ptl
);
4437 * We have consumed all precharges we got in can_attach().
4438 * We try charge one by one, but don't do any additional
4439 * charges to mc.to if we have failed in charge once in attach()
4442 ret
= mem_cgroup_do_precharge(1);
4450 static void mem_cgroup_move_charge(struct mm_struct
*mm
)
4452 struct vm_area_struct
*vma
;
4454 lru_add_drain_all();
4455 down_read(&mm
->mmap_sem
);
4456 for (vma
= mm
->mmap
; vma
; vma
= vma
->vm_next
) {
4458 struct mm_walk mem_cgroup_move_charge_walk
= {
4459 .pmd_entry
= mem_cgroup_move_charge_pte_range
,
4463 if (is_vm_hugetlb_page(vma
))
4465 /* TODO: We don't move charges of shmem/tmpfs pages for now. */
4466 if (vma
->vm_flags
& VM_SHARED
)
4468 ret
= walk_page_range(vma
->vm_start
, vma
->vm_end
,
4469 &mem_cgroup_move_charge_walk
);
4472 * means we have consumed all precharges and failed in
4473 * doing additional charge. Just abandon here.
4477 up_read(&mm
->mmap_sem
);
4480 static void mem_cgroup_move_task(struct cgroup_subsys
*ss
,
4481 struct cgroup
*cont
,
4482 struct cgroup
*old_cont
,
4483 struct task_struct
*p
,
4486 struct mm_struct
*mm
;
4489 /* no need to move charge */
4492 mm
= get_task_mm(p
);
4494 mem_cgroup_move_charge(mm
);
4497 mem_cgroup_clear_mc();
4499 #else /* !CONFIG_MMU */
4500 static int mem_cgroup_can_attach(struct cgroup_subsys
*ss
,
4501 struct cgroup
*cgroup
,
4502 struct task_struct
*p
,
4507 static void mem_cgroup_cancel_attach(struct cgroup_subsys
*ss
,
4508 struct cgroup
*cgroup
,
4509 struct task_struct
*p
,
4513 static void mem_cgroup_move_task(struct cgroup_subsys
*ss
,
4514 struct cgroup
*cont
,
4515 struct cgroup
*old_cont
,
4516 struct task_struct
*p
,
4522 struct cgroup_subsys mem_cgroup_subsys
= {
4524 .subsys_id
= mem_cgroup_subsys_id
,
4525 .create
= mem_cgroup_create
,
4526 .pre_destroy
= mem_cgroup_pre_destroy
,
4527 .destroy
= mem_cgroup_destroy
,
4528 .populate
= mem_cgroup_populate
,
4529 .can_attach
= mem_cgroup_can_attach
,
4530 .cancel_attach
= mem_cgroup_cancel_attach
,
4531 .attach
= mem_cgroup_move_task
,
4536 #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP
4538 static int __init
disable_swap_account(char *s
)
4540 really_do_swap_account
= 0;
4543 __setup("noswapaccount", disable_swap_account
);