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>
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License as published by
11 * the Free Software Foundation; either version 2 of the License, or
12 * (at your option) any later version.
14 * This program is distributed in the hope that it will be useful,
15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 * GNU General Public License for more details.
20 #include <linux/res_counter.h>
21 #include <linux/memcontrol.h>
22 #include <linux/cgroup.h>
24 #include <linux/hugetlb.h>
25 #include <linux/pagemap.h>
26 #include <linux/smp.h>
27 #include <linux/page-flags.h>
28 #include <linux/backing-dev.h>
29 #include <linux/bit_spinlock.h>
30 #include <linux/rcupdate.h>
31 #include <linux/limits.h>
32 #include <linux/mutex.h>
33 #include <linux/rbtree.h>
34 #include <linux/slab.h>
35 #include <linux/swap.h>
36 #include <linux/spinlock.h>
38 #include <linux/seq_file.h>
39 #include <linux/vmalloc.h>
40 #include <linux/mm_inline.h>
41 #include <linux/page_cgroup.h>
42 #include <linux/cpu.h>
45 #include <asm/uaccess.h>
47 struct cgroup_subsys mem_cgroup_subsys __read_mostly
;
48 #define MEM_CGROUP_RECLAIM_RETRIES 5
49 struct mem_cgroup
*root_mem_cgroup __read_mostly
;
51 #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP
52 /* Turned on only when memory cgroup is enabled && really_do_swap_account = 1 */
53 int do_swap_account __read_mostly
;
54 static int really_do_swap_account __initdata
= 1; /* for remember boot option*/
56 #define do_swap_account (0)
59 #define SOFTLIMIT_EVENTS_THRESH (1000)
62 * Statistics for memory cgroup.
64 enum mem_cgroup_stat_index
{
66 * For MEM_CONTAINER_TYPE_ALL, usage = pagecache + rss.
68 MEM_CGROUP_STAT_CACHE
, /* # of pages charged as cache */
69 MEM_CGROUP_STAT_RSS
, /* # of pages charged as anon rss */
70 MEM_CGROUP_STAT_FILE_MAPPED
, /* # of pages charged as file rss */
71 MEM_CGROUP_STAT_PGPGIN_COUNT
, /* # of pages paged in */
72 MEM_CGROUP_STAT_PGPGOUT_COUNT
, /* # of pages paged out */
73 MEM_CGROUP_STAT_EVENTS
, /* sum of pagein + pageout for internal use */
74 MEM_CGROUP_STAT_SWAPOUT
, /* # of pages, swapped out */
76 MEM_CGROUP_STAT_NSTATS
,
79 struct mem_cgroup_stat_cpu
{
80 s64 count
[MEM_CGROUP_STAT_NSTATS
];
81 } ____cacheline_aligned_in_smp
;
83 struct mem_cgroup_stat
{
84 struct mem_cgroup_stat_cpu cpustat
[0];
88 __mem_cgroup_stat_reset_safe(struct mem_cgroup_stat_cpu
*stat
,
89 enum mem_cgroup_stat_index idx
)
95 __mem_cgroup_stat_read_local(struct mem_cgroup_stat_cpu
*stat
,
96 enum mem_cgroup_stat_index idx
)
98 return stat
->count
[idx
];
102 * For accounting under irq disable, no need for increment preempt count.
104 static inline void __mem_cgroup_stat_add_safe(struct mem_cgroup_stat_cpu
*stat
,
105 enum mem_cgroup_stat_index idx
, int val
)
107 stat
->count
[idx
] += val
;
110 static s64
mem_cgroup_read_stat(struct mem_cgroup_stat
*stat
,
111 enum mem_cgroup_stat_index idx
)
115 for_each_possible_cpu(cpu
)
116 ret
+= stat
->cpustat
[cpu
].count
[idx
];
120 static s64
mem_cgroup_local_usage(struct mem_cgroup_stat
*stat
)
124 ret
= mem_cgroup_read_stat(stat
, MEM_CGROUP_STAT_CACHE
);
125 ret
+= mem_cgroup_read_stat(stat
, MEM_CGROUP_STAT_RSS
);
130 * per-zone information in memory controller.
132 struct mem_cgroup_per_zone
{
134 * spin_lock to protect the per cgroup LRU
136 struct list_head lists
[NR_LRU_LISTS
];
137 unsigned long count
[NR_LRU_LISTS
];
139 struct zone_reclaim_stat reclaim_stat
;
140 struct rb_node tree_node
; /* RB tree node */
141 unsigned long long usage_in_excess
;/* Set to the value by which */
142 /* the soft limit is exceeded*/
144 struct mem_cgroup
*mem
; /* Back pointer, we cannot */
145 /* use container_of */
147 /* Macro for accessing counter */
148 #define MEM_CGROUP_ZSTAT(mz, idx) ((mz)->count[(idx)])
150 struct mem_cgroup_per_node
{
151 struct mem_cgroup_per_zone zoneinfo
[MAX_NR_ZONES
];
154 struct mem_cgroup_lru_info
{
155 struct mem_cgroup_per_node
*nodeinfo
[MAX_NUMNODES
];
159 * Cgroups above their limits are maintained in a RB-Tree, independent of
160 * their hierarchy representation
163 struct mem_cgroup_tree_per_zone
{
164 struct rb_root rb_root
;
168 struct mem_cgroup_tree_per_node
{
169 struct mem_cgroup_tree_per_zone rb_tree_per_zone
[MAX_NR_ZONES
];
172 struct mem_cgroup_tree
{
173 struct mem_cgroup_tree_per_node
*rb_tree_per_node
[MAX_NUMNODES
];
176 static struct mem_cgroup_tree soft_limit_tree __read_mostly
;
179 * The memory controller data structure. The memory controller controls both
180 * page cache and RSS per cgroup. We would eventually like to provide
181 * statistics based on the statistics developed by Rik Van Riel for clock-pro,
182 * to help the administrator determine what knobs to tune.
184 * TODO: Add a water mark for the memory controller. Reclaim will begin when
185 * we hit the water mark. May be even add a low water mark, such that
186 * no reclaim occurs from a cgroup at it's low water mark, this is
187 * a feature that will be implemented much later in the future.
190 struct cgroup_subsys_state css
;
192 * the counter to account for memory usage
194 struct res_counter res
;
196 * the counter to account for mem+swap usage.
198 struct res_counter memsw
;
200 * Per cgroup active and inactive list, similar to the
201 * per zone LRU lists.
203 struct mem_cgroup_lru_info info
;
206 protect against reclaim related member.
208 spinlock_t reclaim_param_lock
;
210 int prev_priority
; /* for recording reclaim priority */
213 * While reclaiming in a hierarchy, we cache the last child we
216 int last_scanned_child
;
218 * Should the accounting and control be hierarchical, per subtree?
221 unsigned long last_oom_jiffies
;
224 unsigned int swappiness
;
226 /* set when res.limit == memsw.limit */
227 bool memsw_is_minimum
;
230 * Should we move charges of a task when a task is moved into this
231 * mem_cgroup ? And what type of charges should we move ?
233 unsigned long move_charge_at_immigrate
;
236 * statistics. This must be placed at the end of memcg.
238 struct mem_cgroup_stat stat
;
241 /* Stuffs for move charges at task migration. */
243 * Types of charges to be moved. "move_charge_at_immitgrate" is treated as a
244 * left-shifted bitmap of these types.
247 MOVE_CHARGE_TYPE_ANON
, /* private anonymous page and swap of it */
251 /* "mc" and its members are protected by cgroup_mutex */
252 static struct move_charge_struct
{
253 struct mem_cgroup
*from
;
254 struct mem_cgroup
*to
;
255 unsigned long precharge
;
259 * Maximum loops in mem_cgroup_hierarchical_reclaim(), used for soft
260 * limit reclaim to prevent infinite loops, if they ever occur.
262 #define MEM_CGROUP_MAX_RECLAIM_LOOPS (100)
263 #define MEM_CGROUP_MAX_SOFT_LIMIT_RECLAIM_LOOPS (2)
266 MEM_CGROUP_CHARGE_TYPE_CACHE
= 0,
267 MEM_CGROUP_CHARGE_TYPE_MAPPED
,
268 MEM_CGROUP_CHARGE_TYPE_SHMEM
, /* used by page migration of shmem */
269 MEM_CGROUP_CHARGE_TYPE_FORCE
, /* used by force_empty */
270 MEM_CGROUP_CHARGE_TYPE_SWAPOUT
, /* for accounting swapcache */
271 MEM_CGROUP_CHARGE_TYPE_DROP
, /* a page was unused swap cache */
275 /* only for here (for easy reading.) */
276 #define PCGF_CACHE (1UL << PCG_CACHE)
277 #define PCGF_USED (1UL << PCG_USED)
278 #define PCGF_LOCK (1UL << PCG_LOCK)
279 /* Not used, but added here for completeness */
280 #define PCGF_ACCT (1UL << PCG_ACCT)
282 /* for encoding cft->private value on file */
285 #define MEMFILE_PRIVATE(x, val) (((x) << 16) | (val))
286 #define MEMFILE_TYPE(val) (((val) >> 16) & 0xffff)
287 #define MEMFILE_ATTR(val) ((val) & 0xffff)
290 * Reclaim flags for mem_cgroup_hierarchical_reclaim
292 #define MEM_CGROUP_RECLAIM_NOSWAP_BIT 0x0
293 #define MEM_CGROUP_RECLAIM_NOSWAP (1 << MEM_CGROUP_RECLAIM_NOSWAP_BIT)
294 #define MEM_CGROUP_RECLAIM_SHRINK_BIT 0x1
295 #define MEM_CGROUP_RECLAIM_SHRINK (1 << MEM_CGROUP_RECLAIM_SHRINK_BIT)
296 #define MEM_CGROUP_RECLAIM_SOFT_BIT 0x2
297 #define MEM_CGROUP_RECLAIM_SOFT (1 << MEM_CGROUP_RECLAIM_SOFT_BIT)
299 static void mem_cgroup_get(struct mem_cgroup
*mem
);
300 static void mem_cgroup_put(struct mem_cgroup
*mem
);
301 static struct mem_cgroup
*parent_mem_cgroup(struct mem_cgroup
*mem
);
302 static void drain_all_stock_async(void);
304 static struct mem_cgroup_per_zone
*
305 mem_cgroup_zoneinfo(struct mem_cgroup
*mem
, int nid
, int zid
)
307 return &mem
->info
.nodeinfo
[nid
]->zoneinfo
[zid
];
310 struct cgroup_subsys_state
*mem_cgroup_css(struct mem_cgroup
*mem
)
315 static struct mem_cgroup_per_zone
*
316 page_cgroup_zoneinfo(struct page_cgroup
*pc
)
318 struct mem_cgroup
*mem
= pc
->mem_cgroup
;
319 int nid
= page_cgroup_nid(pc
);
320 int zid
= page_cgroup_zid(pc
);
325 return mem_cgroup_zoneinfo(mem
, nid
, zid
);
328 static struct mem_cgroup_tree_per_zone
*
329 soft_limit_tree_node_zone(int nid
, int zid
)
331 return &soft_limit_tree
.rb_tree_per_node
[nid
]->rb_tree_per_zone
[zid
];
334 static struct mem_cgroup_tree_per_zone
*
335 soft_limit_tree_from_page(struct page
*page
)
337 int nid
= page_to_nid(page
);
338 int zid
= page_zonenum(page
);
340 return &soft_limit_tree
.rb_tree_per_node
[nid
]->rb_tree_per_zone
[zid
];
344 __mem_cgroup_insert_exceeded(struct mem_cgroup
*mem
,
345 struct mem_cgroup_per_zone
*mz
,
346 struct mem_cgroup_tree_per_zone
*mctz
,
347 unsigned long long new_usage_in_excess
)
349 struct rb_node
**p
= &mctz
->rb_root
.rb_node
;
350 struct rb_node
*parent
= NULL
;
351 struct mem_cgroup_per_zone
*mz_node
;
356 mz
->usage_in_excess
= new_usage_in_excess
;
357 if (!mz
->usage_in_excess
)
361 mz_node
= rb_entry(parent
, struct mem_cgroup_per_zone
,
363 if (mz
->usage_in_excess
< mz_node
->usage_in_excess
)
366 * We can't avoid mem cgroups that are over their soft
367 * limit by the same amount
369 else if (mz
->usage_in_excess
>= mz_node
->usage_in_excess
)
372 rb_link_node(&mz
->tree_node
, parent
, p
);
373 rb_insert_color(&mz
->tree_node
, &mctz
->rb_root
);
378 __mem_cgroup_remove_exceeded(struct mem_cgroup
*mem
,
379 struct mem_cgroup_per_zone
*mz
,
380 struct mem_cgroup_tree_per_zone
*mctz
)
384 rb_erase(&mz
->tree_node
, &mctz
->rb_root
);
389 mem_cgroup_remove_exceeded(struct mem_cgroup
*mem
,
390 struct mem_cgroup_per_zone
*mz
,
391 struct mem_cgroup_tree_per_zone
*mctz
)
393 spin_lock(&mctz
->lock
);
394 __mem_cgroup_remove_exceeded(mem
, mz
, mctz
);
395 spin_unlock(&mctz
->lock
);
398 static bool mem_cgroup_soft_limit_check(struct mem_cgroup
*mem
)
403 struct mem_cgroup_stat_cpu
*cpustat
;
406 cpustat
= &mem
->stat
.cpustat
[cpu
];
407 val
= __mem_cgroup_stat_read_local(cpustat
, MEM_CGROUP_STAT_EVENTS
);
408 if (unlikely(val
> SOFTLIMIT_EVENTS_THRESH
)) {
409 __mem_cgroup_stat_reset_safe(cpustat
, MEM_CGROUP_STAT_EVENTS
);
416 static void mem_cgroup_update_tree(struct mem_cgroup
*mem
, struct page
*page
)
418 unsigned long long excess
;
419 struct mem_cgroup_per_zone
*mz
;
420 struct mem_cgroup_tree_per_zone
*mctz
;
421 int nid
= page_to_nid(page
);
422 int zid
= page_zonenum(page
);
423 mctz
= soft_limit_tree_from_page(page
);
426 * Necessary to update all ancestors when hierarchy is used.
427 * because their event counter is not touched.
429 for (; mem
; mem
= parent_mem_cgroup(mem
)) {
430 mz
= mem_cgroup_zoneinfo(mem
, nid
, zid
);
431 excess
= res_counter_soft_limit_excess(&mem
->res
);
433 * We have to update the tree if mz is on RB-tree or
434 * mem is over its softlimit.
436 if (excess
|| mz
->on_tree
) {
437 spin_lock(&mctz
->lock
);
438 /* if on-tree, remove it */
440 __mem_cgroup_remove_exceeded(mem
, mz
, mctz
);
442 * Insert again. mz->usage_in_excess will be updated.
443 * If excess is 0, no tree ops.
445 __mem_cgroup_insert_exceeded(mem
, mz
, mctz
, excess
);
446 spin_unlock(&mctz
->lock
);
451 static void mem_cgroup_remove_from_trees(struct mem_cgroup
*mem
)
454 struct mem_cgroup_per_zone
*mz
;
455 struct mem_cgroup_tree_per_zone
*mctz
;
457 for_each_node_state(node
, N_POSSIBLE
) {
458 for (zone
= 0; zone
< MAX_NR_ZONES
; zone
++) {
459 mz
= mem_cgroup_zoneinfo(mem
, node
, zone
);
460 mctz
= soft_limit_tree_node_zone(node
, zone
);
461 mem_cgroup_remove_exceeded(mem
, mz
, mctz
);
466 static inline unsigned long mem_cgroup_get_excess(struct mem_cgroup
*mem
)
468 return res_counter_soft_limit_excess(&mem
->res
) >> PAGE_SHIFT
;
471 static struct mem_cgroup_per_zone
*
472 __mem_cgroup_largest_soft_limit_node(struct mem_cgroup_tree_per_zone
*mctz
)
474 struct rb_node
*rightmost
= NULL
;
475 struct mem_cgroup_per_zone
*mz
;
479 rightmost
= rb_last(&mctz
->rb_root
);
481 goto done
; /* Nothing to reclaim from */
483 mz
= rb_entry(rightmost
, struct mem_cgroup_per_zone
, tree_node
);
485 * Remove the node now but someone else can add it back,
486 * we will to add it back at the end of reclaim to its correct
487 * position in the tree.
489 __mem_cgroup_remove_exceeded(mz
->mem
, mz
, mctz
);
490 if (!res_counter_soft_limit_excess(&mz
->mem
->res
) ||
491 !css_tryget(&mz
->mem
->css
))
497 static struct mem_cgroup_per_zone
*
498 mem_cgroup_largest_soft_limit_node(struct mem_cgroup_tree_per_zone
*mctz
)
500 struct mem_cgroup_per_zone
*mz
;
502 spin_lock(&mctz
->lock
);
503 mz
= __mem_cgroup_largest_soft_limit_node(mctz
);
504 spin_unlock(&mctz
->lock
);
508 static void mem_cgroup_swap_statistics(struct mem_cgroup
*mem
,
511 int val
= (charge
) ? 1 : -1;
512 struct mem_cgroup_stat
*stat
= &mem
->stat
;
513 struct mem_cgroup_stat_cpu
*cpustat
;
516 cpustat
= &stat
->cpustat
[cpu
];
517 __mem_cgroup_stat_add_safe(cpustat
, MEM_CGROUP_STAT_SWAPOUT
, val
);
521 static void mem_cgroup_charge_statistics(struct mem_cgroup
*mem
,
522 struct page_cgroup
*pc
,
525 int val
= (charge
) ? 1 : -1;
526 struct mem_cgroup_stat
*stat
= &mem
->stat
;
527 struct mem_cgroup_stat_cpu
*cpustat
;
530 cpustat
= &stat
->cpustat
[cpu
];
531 if (PageCgroupCache(pc
))
532 __mem_cgroup_stat_add_safe(cpustat
, MEM_CGROUP_STAT_CACHE
, val
);
534 __mem_cgroup_stat_add_safe(cpustat
, MEM_CGROUP_STAT_RSS
, val
);
537 __mem_cgroup_stat_add_safe(cpustat
,
538 MEM_CGROUP_STAT_PGPGIN_COUNT
, 1);
540 __mem_cgroup_stat_add_safe(cpustat
,
541 MEM_CGROUP_STAT_PGPGOUT_COUNT
, 1);
542 __mem_cgroup_stat_add_safe(cpustat
, MEM_CGROUP_STAT_EVENTS
, 1);
546 static unsigned long mem_cgroup_get_local_zonestat(struct mem_cgroup
*mem
,
550 struct mem_cgroup_per_zone
*mz
;
553 for_each_online_node(nid
)
554 for (zid
= 0; zid
< MAX_NR_ZONES
; zid
++) {
555 mz
= mem_cgroup_zoneinfo(mem
, nid
, zid
);
556 total
+= MEM_CGROUP_ZSTAT(mz
, idx
);
561 static struct mem_cgroup
*mem_cgroup_from_cont(struct cgroup
*cont
)
563 return container_of(cgroup_subsys_state(cont
,
564 mem_cgroup_subsys_id
), struct mem_cgroup
,
568 struct mem_cgroup
*mem_cgroup_from_task(struct task_struct
*p
)
571 * mm_update_next_owner() may clear mm->owner to NULL
572 * if it races with swapoff, page migration, etc.
573 * So this can be called with p == NULL.
578 return container_of(task_subsys_state(p
, mem_cgroup_subsys_id
),
579 struct mem_cgroup
, css
);
582 static struct mem_cgroup
*try_get_mem_cgroup_from_mm(struct mm_struct
*mm
)
584 struct mem_cgroup
*mem
= NULL
;
589 * Because we have no locks, mm->owner's may be being moved to other
590 * cgroup. We use css_tryget() here even if this looks
591 * pessimistic (rather than adding locks here).
595 mem
= mem_cgroup_from_task(rcu_dereference(mm
->owner
));
598 } while (!css_tryget(&mem
->css
));
604 * Call callback function against all cgroup under hierarchy tree.
606 static int mem_cgroup_walk_tree(struct mem_cgroup
*root
, void *data
,
607 int (*func
)(struct mem_cgroup
*, void *))
609 int found
, ret
, nextid
;
610 struct cgroup_subsys_state
*css
;
611 struct mem_cgroup
*mem
;
613 if (!root
->use_hierarchy
)
614 return (*func
)(root
, data
);
622 css
= css_get_next(&mem_cgroup_subsys
, nextid
, &root
->css
,
624 if (css
&& css_tryget(css
))
625 mem
= container_of(css
, struct mem_cgroup
, css
);
629 ret
= (*func
)(mem
, data
);
633 } while (!ret
&& css
);
638 static inline bool mem_cgroup_is_root(struct mem_cgroup
*mem
)
640 return (mem
== root_mem_cgroup
);
644 * Following LRU functions are allowed to be used without PCG_LOCK.
645 * Operations are called by routine of global LRU independently from memcg.
646 * What we have to take care of here is validness of pc->mem_cgroup.
648 * Changes to pc->mem_cgroup happens when
651 * In typical case, "charge" is done before add-to-lru. Exception is SwapCache.
652 * It is added to LRU before charge.
653 * If PCG_USED bit is not set, page_cgroup is not added to this private LRU.
654 * When moving account, the page is not on LRU. It's isolated.
657 void mem_cgroup_del_lru_list(struct page
*page
, enum lru_list lru
)
659 struct page_cgroup
*pc
;
660 struct mem_cgroup_per_zone
*mz
;
662 if (mem_cgroup_disabled())
664 pc
= lookup_page_cgroup(page
);
665 /* can happen while we handle swapcache. */
666 if (!TestClearPageCgroupAcctLRU(pc
))
668 VM_BUG_ON(!pc
->mem_cgroup
);
670 * We don't check PCG_USED bit. It's cleared when the "page" is finally
671 * removed from global LRU.
673 mz
= page_cgroup_zoneinfo(pc
);
674 MEM_CGROUP_ZSTAT(mz
, lru
) -= 1;
675 if (mem_cgroup_is_root(pc
->mem_cgroup
))
677 VM_BUG_ON(list_empty(&pc
->lru
));
678 list_del_init(&pc
->lru
);
682 void mem_cgroup_del_lru(struct page
*page
)
684 mem_cgroup_del_lru_list(page
, page_lru(page
));
687 void mem_cgroup_rotate_lru_list(struct page
*page
, enum lru_list lru
)
689 struct mem_cgroup_per_zone
*mz
;
690 struct page_cgroup
*pc
;
692 if (mem_cgroup_disabled())
695 pc
= lookup_page_cgroup(page
);
697 * Used bit is set without atomic ops but after smp_wmb().
698 * For making pc->mem_cgroup visible, insert smp_rmb() here.
701 /* unused or root page is not rotated. */
702 if (!PageCgroupUsed(pc
) || mem_cgroup_is_root(pc
->mem_cgroup
))
704 mz
= page_cgroup_zoneinfo(pc
);
705 list_move(&pc
->lru
, &mz
->lists
[lru
]);
708 void mem_cgroup_add_lru_list(struct page
*page
, enum lru_list lru
)
710 struct page_cgroup
*pc
;
711 struct mem_cgroup_per_zone
*mz
;
713 if (mem_cgroup_disabled())
715 pc
= lookup_page_cgroup(page
);
716 VM_BUG_ON(PageCgroupAcctLRU(pc
));
718 * Used bit is set without atomic ops but after smp_wmb().
719 * For making pc->mem_cgroup visible, insert smp_rmb() here.
722 if (!PageCgroupUsed(pc
))
725 mz
= page_cgroup_zoneinfo(pc
);
726 MEM_CGROUP_ZSTAT(mz
, lru
) += 1;
727 SetPageCgroupAcctLRU(pc
);
728 if (mem_cgroup_is_root(pc
->mem_cgroup
))
730 list_add(&pc
->lru
, &mz
->lists
[lru
]);
734 * At handling SwapCache, pc->mem_cgroup may be changed while it's linked to
735 * lru because the page may.be reused after it's fully uncharged (because of
736 * SwapCache behavior).To handle that, unlink page_cgroup from LRU when charge
737 * it again. This function is only used to charge SwapCache. It's done under
738 * lock_page and expected that zone->lru_lock is never held.
740 static void mem_cgroup_lru_del_before_commit_swapcache(struct page
*page
)
743 struct zone
*zone
= page_zone(page
);
744 struct page_cgroup
*pc
= lookup_page_cgroup(page
);
746 spin_lock_irqsave(&zone
->lru_lock
, flags
);
748 * Forget old LRU when this page_cgroup is *not* used. This Used bit
749 * is guarded by lock_page() because the page is SwapCache.
751 if (!PageCgroupUsed(pc
))
752 mem_cgroup_del_lru_list(page
, page_lru(page
));
753 spin_unlock_irqrestore(&zone
->lru_lock
, flags
);
756 static void mem_cgroup_lru_add_after_commit_swapcache(struct page
*page
)
759 struct zone
*zone
= page_zone(page
);
760 struct page_cgroup
*pc
= lookup_page_cgroup(page
);
762 spin_lock_irqsave(&zone
->lru_lock
, flags
);
763 /* link when the page is linked to LRU but page_cgroup isn't */
764 if (PageLRU(page
) && !PageCgroupAcctLRU(pc
))
765 mem_cgroup_add_lru_list(page
, page_lru(page
));
766 spin_unlock_irqrestore(&zone
->lru_lock
, flags
);
770 void mem_cgroup_move_lists(struct page
*page
,
771 enum lru_list from
, enum lru_list to
)
773 if (mem_cgroup_disabled())
775 mem_cgroup_del_lru_list(page
, from
);
776 mem_cgroup_add_lru_list(page
, to
);
779 int task_in_mem_cgroup(struct task_struct
*task
, const struct mem_cgroup
*mem
)
782 struct mem_cgroup
*curr
= NULL
;
786 curr
= try_get_mem_cgroup_from_mm(task
->mm
);
792 * We should check use_hierarchy of "mem" not "curr". Because checking
793 * use_hierarchy of "curr" here make this function true if hierarchy is
794 * enabled in "curr" and "curr" is a child of "mem" in *cgroup*
795 * hierarchy(even if use_hierarchy is disabled in "mem").
797 if (mem
->use_hierarchy
)
798 ret
= css_is_ancestor(&curr
->css
, &mem
->css
);
806 * prev_priority control...this will be used in memory reclaim path.
808 int mem_cgroup_get_reclaim_priority(struct mem_cgroup
*mem
)
812 spin_lock(&mem
->reclaim_param_lock
);
813 prev_priority
= mem
->prev_priority
;
814 spin_unlock(&mem
->reclaim_param_lock
);
816 return prev_priority
;
819 void mem_cgroup_note_reclaim_priority(struct mem_cgroup
*mem
, int priority
)
821 spin_lock(&mem
->reclaim_param_lock
);
822 if (priority
< mem
->prev_priority
)
823 mem
->prev_priority
= priority
;
824 spin_unlock(&mem
->reclaim_param_lock
);
827 void mem_cgroup_record_reclaim_priority(struct mem_cgroup
*mem
, int priority
)
829 spin_lock(&mem
->reclaim_param_lock
);
830 mem
->prev_priority
= priority
;
831 spin_unlock(&mem
->reclaim_param_lock
);
834 static int calc_inactive_ratio(struct mem_cgroup
*memcg
, unsigned long *present_pages
)
836 unsigned long active
;
837 unsigned long inactive
;
839 unsigned long inactive_ratio
;
841 inactive
= mem_cgroup_get_local_zonestat(memcg
, LRU_INACTIVE_ANON
);
842 active
= mem_cgroup_get_local_zonestat(memcg
, LRU_ACTIVE_ANON
);
844 gb
= (inactive
+ active
) >> (30 - PAGE_SHIFT
);
846 inactive_ratio
= int_sqrt(10 * gb
);
851 present_pages
[0] = inactive
;
852 present_pages
[1] = active
;
855 return inactive_ratio
;
858 int mem_cgroup_inactive_anon_is_low(struct mem_cgroup
*memcg
)
860 unsigned long active
;
861 unsigned long inactive
;
862 unsigned long present_pages
[2];
863 unsigned long inactive_ratio
;
865 inactive_ratio
= calc_inactive_ratio(memcg
, present_pages
);
867 inactive
= present_pages
[0];
868 active
= present_pages
[1];
870 if (inactive
* inactive_ratio
< active
)
876 int mem_cgroup_inactive_file_is_low(struct mem_cgroup
*memcg
)
878 unsigned long active
;
879 unsigned long inactive
;
881 inactive
= mem_cgroup_get_local_zonestat(memcg
, LRU_INACTIVE_FILE
);
882 active
= mem_cgroup_get_local_zonestat(memcg
, LRU_ACTIVE_FILE
);
884 return (active
> inactive
);
887 unsigned long mem_cgroup_zone_nr_pages(struct mem_cgroup
*memcg
,
891 int nid
= zone
->zone_pgdat
->node_id
;
892 int zid
= zone_idx(zone
);
893 struct mem_cgroup_per_zone
*mz
= mem_cgroup_zoneinfo(memcg
, nid
, zid
);
895 return MEM_CGROUP_ZSTAT(mz
, lru
);
898 struct zone_reclaim_stat
*mem_cgroup_get_reclaim_stat(struct mem_cgroup
*memcg
,
901 int nid
= zone
->zone_pgdat
->node_id
;
902 int zid
= zone_idx(zone
);
903 struct mem_cgroup_per_zone
*mz
= mem_cgroup_zoneinfo(memcg
, nid
, zid
);
905 return &mz
->reclaim_stat
;
908 struct zone_reclaim_stat
*
909 mem_cgroup_get_reclaim_stat_from_page(struct page
*page
)
911 struct page_cgroup
*pc
;
912 struct mem_cgroup_per_zone
*mz
;
914 if (mem_cgroup_disabled())
917 pc
= lookup_page_cgroup(page
);
919 * Used bit is set without atomic ops but after smp_wmb().
920 * For making pc->mem_cgroup visible, insert smp_rmb() here.
923 if (!PageCgroupUsed(pc
))
926 mz
= page_cgroup_zoneinfo(pc
);
930 return &mz
->reclaim_stat
;
933 unsigned long mem_cgroup_isolate_pages(unsigned long nr_to_scan
,
934 struct list_head
*dst
,
935 unsigned long *scanned
, int order
,
936 int mode
, struct zone
*z
,
937 struct mem_cgroup
*mem_cont
,
938 int active
, int file
)
940 unsigned long nr_taken
= 0;
944 struct list_head
*src
;
945 struct page_cgroup
*pc
, *tmp
;
946 int nid
= z
->zone_pgdat
->node_id
;
947 int zid
= zone_idx(z
);
948 struct mem_cgroup_per_zone
*mz
;
949 int lru
= LRU_FILE
* file
+ active
;
953 mz
= mem_cgroup_zoneinfo(mem_cont
, nid
, zid
);
954 src
= &mz
->lists
[lru
];
957 list_for_each_entry_safe_reverse(pc
, tmp
, src
, lru
) {
958 if (scan
>= nr_to_scan
)
962 if (unlikely(!PageCgroupUsed(pc
)))
964 if (unlikely(!PageLRU(page
)))
968 ret
= __isolate_lru_page(page
, mode
, file
);
971 list_move(&page
->lru
, dst
);
972 mem_cgroup_del_lru(page
);
976 /* we don't affect global LRU but rotate in our LRU */
977 mem_cgroup_rotate_lru_list(page
, page_lru(page
));
988 #define mem_cgroup_from_res_counter(counter, member) \
989 container_of(counter, struct mem_cgroup, member)
991 static bool mem_cgroup_check_under_limit(struct mem_cgroup
*mem
)
993 if (do_swap_account
) {
994 if (res_counter_check_under_limit(&mem
->res
) &&
995 res_counter_check_under_limit(&mem
->memsw
))
998 if (res_counter_check_under_limit(&mem
->res
))
1003 static unsigned int get_swappiness(struct mem_cgroup
*memcg
)
1005 struct cgroup
*cgrp
= memcg
->css
.cgroup
;
1006 unsigned int swappiness
;
1009 if (cgrp
->parent
== NULL
)
1010 return vm_swappiness
;
1012 spin_lock(&memcg
->reclaim_param_lock
);
1013 swappiness
= memcg
->swappiness
;
1014 spin_unlock(&memcg
->reclaim_param_lock
);
1019 static int mem_cgroup_count_children_cb(struct mem_cgroup
*mem
, void *data
)
1027 * mem_cgroup_print_mem_info: Called from OOM with tasklist_lock held in read mode.
1028 * @memcg: The memory cgroup that went over limit
1029 * @p: Task that is going to be killed
1031 * NOTE: @memcg and @p's mem_cgroup can be different when hierarchy is
1034 void mem_cgroup_print_oom_info(struct mem_cgroup
*memcg
, struct task_struct
*p
)
1036 struct cgroup
*task_cgrp
;
1037 struct cgroup
*mem_cgrp
;
1039 * Need a buffer in BSS, can't rely on allocations. The code relies
1040 * on the assumption that OOM is serialized for memory controller.
1041 * If this assumption is broken, revisit this code.
1043 static char memcg_name
[PATH_MAX
];
1052 mem_cgrp
= memcg
->css
.cgroup
;
1053 task_cgrp
= task_cgroup(p
, mem_cgroup_subsys_id
);
1055 ret
= cgroup_path(task_cgrp
, memcg_name
, PATH_MAX
);
1058 * Unfortunately, we are unable to convert to a useful name
1059 * But we'll still print out the usage information
1066 printk(KERN_INFO
"Task in %s killed", memcg_name
);
1069 ret
= cgroup_path(mem_cgrp
, memcg_name
, PATH_MAX
);
1077 * Continues from above, so we don't need an KERN_ level
1079 printk(KERN_CONT
" as a result of limit of %s\n", memcg_name
);
1082 printk(KERN_INFO
"memory: usage %llukB, limit %llukB, failcnt %llu\n",
1083 res_counter_read_u64(&memcg
->res
, RES_USAGE
) >> 10,
1084 res_counter_read_u64(&memcg
->res
, RES_LIMIT
) >> 10,
1085 res_counter_read_u64(&memcg
->res
, RES_FAILCNT
));
1086 printk(KERN_INFO
"memory+swap: usage %llukB, limit %llukB, "
1088 res_counter_read_u64(&memcg
->memsw
, RES_USAGE
) >> 10,
1089 res_counter_read_u64(&memcg
->memsw
, RES_LIMIT
) >> 10,
1090 res_counter_read_u64(&memcg
->memsw
, RES_FAILCNT
));
1094 * This function returns the number of memcg under hierarchy tree. Returns
1095 * 1(self count) if no children.
1097 static int mem_cgroup_count_children(struct mem_cgroup
*mem
)
1100 mem_cgroup_walk_tree(mem
, &num
, mem_cgroup_count_children_cb
);
1105 * Visit the first child (need not be the first child as per the ordering
1106 * of the cgroup list, since we track last_scanned_child) of @mem and use
1107 * that to reclaim free pages from.
1109 static struct mem_cgroup
*
1110 mem_cgroup_select_victim(struct mem_cgroup
*root_mem
)
1112 struct mem_cgroup
*ret
= NULL
;
1113 struct cgroup_subsys_state
*css
;
1116 if (!root_mem
->use_hierarchy
) {
1117 css_get(&root_mem
->css
);
1123 nextid
= root_mem
->last_scanned_child
+ 1;
1124 css
= css_get_next(&mem_cgroup_subsys
, nextid
, &root_mem
->css
,
1126 if (css
&& css_tryget(css
))
1127 ret
= container_of(css
, struct mem_cgroup
, css
);
1130 /* Updates scanning parameter */
1131 spin_lock(&root_mem
->reclaim_param_lock
);
1133 /* this means start scan from ID:1 */
1134 root_mem
->last_scanned_child
= 0;
1136 root_mem
->last_scanned_child
= found
;
1137 spin_unlock(&root_mem
->reclaim_param_lock
);
1144 * Scan the hierarchy if needed to reclaim memory. We remember the last child
1145 * we reclaimed from, so that we don't end up penalizing one child extensively
1146 * based on its position in the children list.
1148 * root_mem is the original ancestor that we've been reclaim from.
1150 * We give up and return to the caller when we visit root_mem twice.
1151 * (other groups can be removed while we're walking....)
1153 * If shrink==true, for avoiding to free too much, this returns immedieately.
1155 static int mem_cgroup_hierarchical_reclaim(struct mem_cgroup
*root_mem
,
1158 unsigned long reclaim_options
)
1160 struct mem_cgroup
*victim
;
1163 bool noswap
= reclaim_options
& MEM_CGROUP_RECLAIM_NOSWAP
;
1164 bool shrink
= reclaim_options
& MEM_CGROUP_RECLAIM_SHRINK
;
1165 bool check_soft
= reclaim_options
& MEM_CGROUP_RECLAIM_SOFT
;
1166 unsigned long excess
= mem_cgroup_get_excess(root_mem
);
1168 /* If memsw_is_minimum==1, swap-out is of-no-use. */
1169 if (root_mem
->memsw_is_minimum
)
1173 victim
= mem_cgroup_select_victim(root_mem
);
1174 if (victim
== root_mem
) {
1177 drain_all_stock_async();
1180 * If we have not been able to reclaim
1181 * anything, it might because there are
1182 * no reclaimable pages under this hierarchy
1184 if (!check_soft
|| !total
) {
1185 css_put(&victim
->css
);
1189 * We want to do more targetted reclaim.
1190 * excess >> 2 is not to excessive so as to
1191 * reclaim too much, nor too less that we keep
1192 * coming back to reclaim from this cgroup
1194 if (total
>= (excess
>> 2) ||
1195 (loop
> MEM_CGROUP_MAX_RECLAIM_LOOPS
)) {
1196 css_put(&victim
->css
);
1201 if (!mem_cgroup_local_usage(&victim
->stat
)) {
1202 /* this cgroup's local usage == 0 */
1203 css_put(&victim
->css
);
1206 /* we use swappiness of local cgroup */
1208 ret
= mem_cgroup_shrink_node_zone(victim
, gfp_mask
,
1209 noswap
, get_swappiness(victim
), zone
,
1210 zone
->zone_pgdat
->node_id
);
1212 ret
= try_to_free_mem_cgroup_pages(victim
, gfp_mask
,
1213 noswap
, get_swappiness(victim
));
1214 css_put(&victim
->css
);
1216 * At shrinking usage, we can't check we should stop here or
1217 * reclaim more. It's depends on callers. last_scanned_child
1218 * will work enough for keeping fairness under tree.
1224 if (res_counter_check_under_soft_limit(&root_mem
->res
))
1226 } else if (mem_cgroup_check_under_limit(root_mem
))
1232 bool mem_cgroup_oom_called(struct task_struct
*task
)
1235 struct mem_cgroup
*mem
;
1236 struct mm_struct
*mm
;
1242 mem
= mem_cgroup_from_task(rcu_dereference(mm
->owner
));
1243 if (mem
&& time_before(jiffies
, mem
->last_oom_jiffies
+ HZ
/10))
1249 static int record_last_oom_cb(struct mem_cgroup
*mem
, void *data
)
1251 mem
->last_oom_jiffies
= jiffies
;
1255 static void record_last_oom(struct mem_cgroup
*mem
)
1257 mem_cgroup_walk_tree(mem
, NULL
, record_last_oom_cb
);
1261 * Currently used to update mapped file statistics, but the routine can be
1262 * generalized to update other statistics as well.
1264 void mem_cgroup_update_file_mapped(struct page
*page
, int val
)
1266 struct mem_cgroup
*mem
;
1267 struct mem_cgroup_stat
*stat
;
1268 struct mem_cgroup_stat_cpu
*cpustat
;
1270 struct page_cgroup
*pc
;
1272 pc
= lookup_page_cgroup(page
);
1276 lock_page_cgroup(pc
);
1277 mem
= pc
->mem_cgroup
;
1281 if (!PageCgroupUsed(pc
))
1285 * Preemption is already disabled, we don't need get_cpu()
1287 cpu
= smp_processor_id();
1289 cpustat
= &stat
->cpustat
[cpu
];
1291 __mem_cgroup_stat_add_safe(cpustat
, MEM_CGROUP_STAT_FILE_MAPPED
, val
);
1293 unlock_page_cgroup(pc
);
1297 * size of first charge trial. "32" comes from vmscan.c's magic value.
1298 * TODO: maybe necessary to use big numbers in big irons.
1300 #define CHARGE_SIZE (32 * PAGE_SIZE)
1301 struct memcg_stock_pcp
{
1302 struct mem_cgroup
*cached
; /* this never be root cgroup */
1304 struct work_struct work
;
1306 static DEFINE_PER_CPU(struct memcg_stock_pcp
, memcg_stock
);
1307 static atomic_t memcg_drain_count
;
1310 * Try to consume stocked charge on this cpu. If success, PAGE_SIZE is consumed
1311 * from local stock and true is returned. If the stock is 0 or charges from a
1312 * cgroup which is not current target, returns false. This stock will be
1315 static bool consume_stock(struct mem_cgroup
*mem
)
1317 struct memcg_stock_pcp
*stock
;
1320 stock
= &get_cpu_var(memcg_stock
);
1321 if (mem
== stock
->cached
&& stock
->charge
)
1322 stock
->charge
-= PAGE_SIZE
;
1323 else /* need to call res_counter_charge */
1325 put_cpu_var(memcg_stock
);
1330 * Returns stocks cached in percpu to res_counter and reset cached information.
1332 static void drain_stock(struct memcg_stock_pcp
*stock
)
1334 struct mem_cgroup
*old
= stock
->cached
;
1336 if (stock
->charge
) {
1337 res_counter_uncharge(&old
->res
, stock
->charge
);
1338 if (do_swap_account
)
1339 res_counter_uncharge(&old
->memsw
, stock
->charge
);
1341 stock
->cached
= NULL
;
1346 * This must be called under preempt disabled or must be called by
1347 * a thread which is pinned to local cpu.
1349 static void drain_local_stock(struct work_struct
*dummy
)
1351 struct memcg_stock_pcp
*stock
= &__get_cpu_var(memcg_stock
);
1356 * Cache charges(val) which is from res_counter, to local per_cpu area.
1357 * This will be consumed by consumt_stock() function, later.
1359 static void refill_stock(struct mem_cgroup
*mem
, int val
)
1361 struct memcg_stock_pcp
*stock
= &get_cpu_var(memcg_stock
);
1363 if (stock
->cached
!= mem
) { /* reset if necessary */
1365 stock
->cached
= mem
;
1367 stock
->charge
+= val
;
1368 put_cpu_var(memcg_stock
);
1372 * Tries to drain stocked charges in other cpus. This function is asynchronous
1373 * and just put a work per cpu for draining localy on each cpu. Caller can
1374 * expects some charges will be back to res_counter later but cannot wait for
1377 static void drain_all_stock_async(void)
1380 /* This function is for scheduling "drain" in asynchronous way.
1381 * The result of "drain" is not directly handled by callers. Then,
1382 * if someone is calling drain, we don't have to call drain more.
1383 * Anyway, WORK_STRUCT_PENDING check in queue_work_on() will catch if
1384 * there is a race. We just do loose check here.
1386 if (atomic_read(&memcg_drain_count
))
1388 /* Notify other cpus that system-wide "drain" is running */
1389 atomic_inc(&memcg_drain_count
);
1391 for_each_online_cpu(cpu
) {
1392 struct memcg_stock_pcp
*stock
= &per_cpu(memcg_stock
, cpu
);
1393 schedule_work_on(cpu
, &stock
->work
);
1396 atomic_dec(&memcg_drain_count
);
1397 /* We don't wait for flush_work */
1400 /* This is a synchronous drain interface. */
1401 static void drain_all_stock_sync(void)
1403 /* called when force_empty is called */
1404 atomic_inc(&memcg_drain_count
);
1405 schedule_on_each_cpu(drain_local_stock
);
1406 atomic_dec(&memcg_drain_count
);
1409 static int __cpuinit
memcg_stock_cpu_callback(struct notifier_block
*nb
,
1410 unsigned long action
,
1413 int cpu
= (unsigned long)hcpu
;
1414 struct memcg_stock_pcp
*stock
;
1416 if (action
!= CPU_DEAD
)
1418 stock
= &per_cpu(memcg_stock
, cpu
);
1424 * Unlike exported interface, "oom" parameter is added. if oom==true,
1425 * oom-killer can be invoked.
1427 static int __mem_cgroup_try_charge(struct mm_struct
*mm
,
1428 gfp_t gfp_mask
, struct mem_cgroup
**memcg
,
1429 bool oom
, struct page
*page
)
1431 struct mem_cgroup
*mem
, *mem_over_limit
;
1432 int nr_retries
= MEM_CGROUP_RECLAIM_RETRIES
;
1433 struct res_counter
*fail_res
;
1434 int csize
= CHARGE_SIZE
;
1436 if (unlikely(test_thread_flag(TIF_MEMDIE
))) {
1437 /* Don't account this! */
1443 * We always charge the cgroup the mm_struct belongs to.
1444 * The mm_struct's mem_cgroup changes on task migration if the
1445 * thread group leader migrates. It's possible that mm is not
1446 * set, if so charge the init_mm (happens for pagecache usage).
1450 mem
= try_get_mem_cgroup_from_mm(mm
);
1458 VM_BUG_ON(css_is_removed(&mem
->css
));
1459 if (mem_cgroup_is_root(mem
))
1464 unsigned long flags
= 0;
1466 if (consume_stock(mem
))
1469 ret
= res_counter_charge(&mem
->res
, csize
, &fail_res
);
1471 if (!do_swap_account
)
1473 ret
= res_counter_charge(&mem
->memsw
, csize
, &fail_res
);
1476 /* mem+swap counter fails */
1477 res_counter_uncharge(&mem
->res
, csize
);
1478 flags
|= MEM_CGROUP_RECLAIM_NOSWAP
;
1479 mem_over_limit
= mem_cgroup_from_res_counter(fail_res
,
1482 /* mem counter fails */
1483 mem_over_limit
= mem_cgroup_from_res_counter(fail_res
,
1486 /* reduce request size and retry */
1487 if (csize
> PAGE_SIZE
) {
1491 if (!(gfp_mask
& __GFP_WAIT
))
1494 ret
= mem_cgroup_hierarchical_reclaim(mem_over_limit
, NULL
,
1500 * try_to_free_mem_cgroup_pages() might not give us a full
1501 * picture of reclaim. Some pages are reclaimed and might be
1502 * moved to swap cache or just unmapped from the cgroup.
1503 * Check the limit again to see if the reclaim reduced the
1504 * current usage of the cgroup before giving up
1507 if (mem_cgroup_check_under_limit(mem_over_limit
))
1510 if (!nr_retries
--) {
1512 mem_cgroup_out_of_memory(mem_over_limit
, gfp_mask
);
1513 record_last_oom(mem_over_limit
);
1518 if (csize
> PAGE_SIZE
)
1519 refill_stock(mem
, csize
- PAGE_SIZE
);
1522 * Insert ancestor (and ancestor's ancestors), to softlimit RB-tree.
1523 * if they exceeds softlimit.
1525 if (page
&& mem_cgroup_soft_limit_check(mem
))
1526 mem_cgroup_update_tree(mem
, page
);
1535 * Somemtimes we have to undo a charge we got by try_charge().
1536 * This function is for that and do uncharge, put css's refcnt.
1537 * gotten by try_charge().
1539 static void mem_cgroup_cancel_charge(struct mem_cgroup
*mem
)
1541 if (!mem_cgroup_is_root(mem
)) {
1542 res_counter_uncharge(&mem
->res
, PAGE_SIZE
);
1543 if (do_swap_account
)
1544 res_counter_uncharge(&mem
->memsw
, PAGE_SIZE
);
1550 * A helper function to get mem_cgroup from ID. must be called under
1551 * rcu_read_lock(). The caller must check css_is_removed() or some if
1552 * it's concern. (dropping refcnt from swap can be called against removed
1555 static struct mem_cgroup
*mem_cgroup_lookup(unsigned short id
)
1557 struct cgroup_subsys_state
*css
;
1559 /* ID 0 is unused ID */
1562 css
= css_lookup(&mem_cgroup_subsys
, id
);
1565 return container_of(css
, struct mem_cgroup
, css
);
1568 struct mem_cgroup
*try_get_mem_cgroup_from_page(struct page
*page
)
1570 struct mem_cgroup
*mem
= NULL
;
1571 struct page_cgroup
*pc
;
1575 VM_BUG_ON(!PageLocked(page
));
1577 pc
= lookup_page_cgroup(page
);
1578 lock_page_cgroup(pc
);
1579 if (PageCgroupUsed(pc
)) {
1580 mem
= pc
->mem_cgroup
;
1581 if (mem
&& !css_tryget(&mem
->css
))
1583 } else if (PageSwapCache(page
)) {
1584 ent
.val
= page_private(page
);
1585 id
= lookup_swap_cgroup(ent
);
1587 mem
= mem_cgroup_lookup(id
);
1588 if (mem
&& !css_tryget(&mem
->css
))
1592 unlock_page_cgroup(pc
);
1597 * commit a charge got by __mem_cgroup_try_charge() and makes page_cgroup to be
1598 * USED state. If already USED, uncharge and return.
1601 static void __mem_cgroup_commit_charge(struct mem_cgroup
*mem
,
1602 struct page_cgroup
*pc
,
1603 enum charge_type ctype
)
1605 /* try_charge() can return NULL to *memcg, taking care of it. */
1609 lock_page_cgroup(pc
);
1610 if (unlikely(PageCgroupUsed(pc
))) {
1611 unlock_page_cgroup(pc
);
1612 mem_cgroup_cancel_charge(mem
);
1616 pc
->mem_cgroup
= mem
;
1618 * We access a page_cgroup asynchronously without lock_page_cgroup().
1619 * Especially when a page_cgroup is taken from a page, pc->mem_cgroup
1620 * is accessed after testing USED bit. To make pc->mem_cgroup visible
1621 * before USED bit, we need memory barrier here.
1622 * See mem_cgroup_add_lru_list(), etc.
1626 case MEM_CGROUP_CHARGE_TYPE_CACHE
:
1627 case MEM_CGROUP_CHARGE_TYPE_SHMEM
:
1628 SetPageCgroupCache(pc
);
1629 SetPageCgroupUsed(pc
);
1631 case MEM_CGROUP_CHARGE_TYPE_MAPPED
:
1632 ClearPageCgroupCache(pc
);
1633 SetPageCgroupUsed(pc
);
1639 mem_cgroup_charge_statistics(mem
, pc
, true);
1641 unlock_page_cgroup(pc
);
1645 * __mem_cgroup_move_account - move account of the page
1646 * @pc: page_cgroup of the page.
1647 * @from: mem_cgroup which the page is moved from.
1648 * @to: mem_cgroup which the page is moved to. @from != @to.
1650 * The caller must confirm following.
1651 * - page is not on LRU (isolate_page() is useful.)
1652 * - the pc is locked, used, and ->mem_cgroup points to @from.
1654 * This function does "uncharge" from old cgroup but doesn't do "charge" to
1655 * new cgroup. It should be done by a caller.
1658 static void __mem_cgroup_move_account(struct page_cgroup
*pc
,
1659 struct mem_cgroup
*from
, struct mem_cgroup
*to
)
1663 struct mem_cgroup_stat
*stat
;
1664 struct mem_cgroup_stat_cpu
*cpustat
;
1666 VM_BUG_ON(from
== to
);
1667 VM_BUG_ON(PageLRU(pc
->page
));
1668 VM_BUG_ON(!PageCgroupLocked(pc
));
1669 VM_BUG_ON(!PageCgroupUsed(pc
));
1670 VM_BUG_ON(pc
->mem_cgroup
!= from
);
1672 if (!mem_cgroup_is_root(from
))
1673 res_counter_uncharge(&from
->res
, PAGE_SIZE
);
1674 mem_cgroup_charge_statistics(from
, pc
, false);
1677 if (page_mapped(page
) && !PageAnon(page
)) {
1678 cpu
= smp_processor_id();
1679 /* Update mapped_file data for mem_cgroup "from" */
1681 cpustat
= &stat
->cpustat
[cpu
];
1682 __mem_cgroup_stat_add_safe(cpustat
, MEM_CGROUP_STAT_FILE_MAPPED
,
1685 /* Update mapped_file data for mem_cgroup "to" */
1687 cpustat
= &stat
->cpustat
[cpu
];
1688 __mem_cgroup_stat_add_safe(cpustat
, MEM_CGROUP_STAT_FILE_MAPPED
,
1692 if (do_swap_account
&& !mem_cgroup_is_root(from
))
1693 res_counter_uncharge(&from
->memsw
, PAGE_SIZE
);
1694 css_put(&from
->css
);
1697 pc
->mem_cgroup
= to
;
1698 mem_cgroup_charge_statistics(to
, pc
, true);
1700 * We charges against "to" which may not have any tasks. Then, "to"
1701 * can be under rmdir(). But in current implementation, caller of
1702 * this function is just force_empty() and move charge, so it's
1703 * garanteed that "to" is never removed. So, we don't check rmdir
1709 * check whether the @pc is valid for moving account and call
1710 * __mem_cgroup_move_account()
1712 static int mem_cgroup_move_account(struct page_cgroup
*pc
,
1713 struct mem_cgroup
*from
, struct mem_cgroup
*to
)
1716 lock_page_cgroup(pc
);
1717 if (PageCgroupUsed(pc
) && pc
->mem_cgroup
== from
) {
1718 __mem_cgroup_move_account(pc
, from
, to
);
1721 unlock_page_cgroup(pc
);
1726 * move charges to its parent.
1729 static int mem_cgroup_move_parent(struct page_cgroup
*pc
,
1730 struct mem_cgroup
*child
,
1733 struct page
*page
= pc
->page
;
1734 struct cgroup
*cg
= child
->css
.cgroup
;
1735 struct cgroup
*pcg
= cg
->parent
;
1736 struct mem_cgroup
*parent
;
1744 if (!get_page_unless_zero(page
))
1746 if (isolate_lru_page(page
))
1749 parent
= mem_cgroup_from_cont(pcg
);
1750 ret
= __mem_cgroup_try_charge(NULL
, gfp_mask
, &parent
, false, page
);
1754 ret
= mem_cgroup_move_account(pc
, child
, parent
);
1756 css_put(&parent
->css
); /* drop extra refcnt by try_charge() */
1758 mem_cgroup_cancel_charge(parent
); /* does css_put */
1760 putback_lru_page(page
);
1768 * Charge the memory controller for page usage.
1770 * 0 if the charge was successful
1771 * < 0 if the cgroup is over its limit
1773 static int mem_cgroup_charge_common(struct page
*page
, struct mm_struct
*mm
,
1774 gfp_t gfp_mask
, enum charge_type ctype
,
1775 struct mem_cgroup
*memcg
)
1777 struct mem_cgroup
*mem
;
1778 struct page_cgroup
*pc
;
1781 pc
= lookup_page_cgroup(page
);
1782 /* can happen at boot */
1788 ret
= __mem_cgroup_try_charge(mm
, gfp_mask
, &mem
, true, page
);
1792 __mem_cgroup_commit_charge(mem
, pc
, ctype
);
1796 int mem_cgroup_newpage_charge(struct page
*page
,
1797 struct mm_struct
*mm
, gfp_t gfp_mask
)
1799 if (mem_cgroup_disabled())
1801 if (PageCompound(page
))
1804 * If already mapped, we don't have to account.
1805 * If page cache, page->mapping has address_space.
1806 * But page->mapping may have out-of-use anon_vma pointer,
1807 * detecit it by PageAnon() check. newly-mapped-anon's page->mapping
1810 if (page_mapped(page
) || (page
->mapping
&& !PageAnon(page
)))
1814 return mem_cgroup_charge_common(page
, mm
, gfp_mask
,
1815 MEM_CGROUP_CHARGE_TYPE_MAPPED
, NULL
);
1819 __mem_cgroup_commit_charge_swapin(struct page
*page
, struct mem_cgroup
*ptr
,
1820 enum charge_type ctype
);
1822 int mem_cgroup_cache_charge(struct page
*page
, struct mm_struct
*mm
,
1825 struct mem_cgroup
*mem
= NULL
;
1828 if (mem_cgroup_disabled())
1830 if (PageCompound(page
))
1833 * Corner case handling. This is called from add_to_page_cache()
1834 * in usual. But some FS (shmem) precharges this page before calling it
1835 * and call add_to_page_cache() with GFP_NOWAIT.
1837 * For GFP_NOWAIT case, the page may be pre-charged before calling
1838 * add_to_page_cache(). (See shmem.c) check it here and avoid to call
1839 * charge twice. (It works but has to pay a bit larger cost.)
1840 * And when the page is SwapCache, it should take swap information
1841 * into account. This is under lock_page() now.
1843 if (!(gfp_mask
& __GFP_WAIT
)) {
1844 struct page_cgroup
*pc
;
1847 pc
= lookup_page_cgroup(page
);
1850 lock_page_cgroup(pc
);
1851 if (PageCgroupUsed(pc
)) {
1852 unlock_page_cgroup(pc
);
1855 unlock_page_cgroup(pc
);
1858 if (unlikely(!mm
&& !mem
))
1861 if (page_is_file_cache(page
))
1862 return mem_cgroup_charge_common(page
, mm
, gfp_mask
,
1863 MEM_CGROUP_CHARGE_TYPE_CACHE
, NULL
);
1866 if (PageSwapCache(page
)) {
1867 ret
= mem_cgroup_try_charge_swapin(mm
, page
, gfp_mask
, &mem
);
1869 __mem_cgroup_commit_charge_swapin(page
, mem
,
1870 MEM_CGROUP_CHARGE_TYPE_SHMEM
);
1872 ret
= mem_cgroup_charge_common(page
, mm
, gfp_mask
,
1873 MEM_CGROUP_CHARGE_TYPE_SHMEM
, mem
);
1879 * While swap-in, try_charge -> commit or cancel, the page is locked.
1880 * And when try_charge() successfully returns, one refcnt to memcg without
1881 * struct page_cgroup is acquired. This refcnt will be consumed by
1882 * "commit()" or removed by "cancel()"
1884 int mem_cgroup_try_charge_swapin(struct mm_struct
*mm
,
1886 gfp_t mask
, struct mem_cgroup
**ptr
)
1888 struct mem_cgroup
*mem
;
1891 if (mem_cgroup_disabled())
1894 if (!do_swap_account
)
1897 * A racing thread's fault, or swapoff, may have already updated
1898 * the pte, and even removed page from swap cache: in those cases
1899 * do_swap_page()'s pte_same() test will fail; but there's also a
1900 * KSM case which does need to charge the page.
1902 if (!PageSwapCache(page
))
1904 mem
= try_get_mem_cgroup_from_page(page
);
1908 ret
= __mem_cgroup_try_charge(NULL
, mask
, ptr
, true, page
);
1909 /* drop extra refcnt from tryget */
1915 return __mem_cgroup_try_charge(mm
, mask
, ptr
, true, page
);
1919 __mem_cgroup_commit_charge_swapin(struct page
*page
, struct mem_cgroup
*ptr
,
1920 enum charge_type ctype
)
1922 struct page_cgroup
*pc
;
1924 if (mem_cgroup_disabled())
1928 cgroup_exclude_rmdir(&ptr
->css
);
1929 pc
= lookup_page_cgroup(page
);
1930 mem_cgroup_lru_del_before_commit_swapcache(page
);
1931 __mem_cgroup_commit_charge(ptr
, pc
, ctype
);
1932 mem_cgroup_lru_add_after_commit_swapcache(page
);
1934 * Now swap is on-memory. This means this page may be
1935 * counted both as mem and swap....double count.
1936 * Fix it by uncharging from memsw. Basically, this SwapCache is stable
1937 * under lock_page(). But in do_swap_page()::memory.c, reuse_swap_page()
1938 * may call delete_from_swap_cache() before reach here.
1940 if (do_swap_account
&& PageSwapCache(page
)) {
1941 swp_entry_t ent
= {.val
= page_private(page
)};
1943 struct mem_cgroup
*memcg
;
1945 id
= swap_cgroup_record(ent
, 0);
1947 memcg
= mem_cgroup_lookup(id
);
1950 * This recorded memcg can be obsolete one. So, avoid
1951 * calling css_tryget
1953 if (!mem_cgroup_is_root(memcg
))
1954 res_counter_uncharge(&memcg
->memsw
, PAGE_SIZE
);
1955 mem_cgroup_swap_statistics(memcg
, false);
1956 mem_cgroup_put(memcg
);
1961 * At swapin, we may charge account against cgroup which has no tasks.
1962 * So, rmdir()->pre_destroy() can be called while we do this charge.
1963 * In that case, we need to call pre_destroy() again. check it here.
1965 cgroup_release_and_wakeup_rmdir(&ptr
->css
);
1968 void mem_cgroup_commit_charge_swapin(struct page
*page
, struct mem_cgroup
*ptr
)
1970 __mem_cgroup_commit_charge_swapin(page
, ptr
,
1971 MEM_CGROUP_CHARGE_TYPE_MAPPED
);
1974 void mem_cgroup_cancel_charge_swapin(struct mem_cgroup
*mem
)
1976 if (mem_cgroup_disabled())
1980 mem_cgroup_cancel_charge(mem
);
1984 __do_uncharge(struct mem_cgroup
*mem
, const enum charge_type ctype
)
1986 struct memcg_batch_info
*batch
= NULL
;
1987 bool uncharge_memsw
= true;
1988 /* If swapout, usage of swap doesn't decrease */
1989 if (!do_swap_account
|| ctype
== MEM_CGROUP_CHARGE_TYPE_SWAPOUT
)
1990 uncharge_memsw
= false;
1992 * do_batch > 0 when unmapping pages or inode invalidate/truncate.
1993 * In those cases, all pages freed continously can be expected to be in
1994 * the same cgroup and we have chance to coalesce uncharges.
1995 * But we do uncharge one by one if this is killed by OOM(TIF_MEMDIE)
1996 * because we want to do uncharge as soon as possible.
1998 if (!current
->memcg_batch
.do_batch
|| test_thread_flag(TIF_MEMDIE
))
1999 goto direct_uncharge
;
2001 batch
= ¤t
->memcg_batch
;
2003 * In usual, we do css_get() when we remember memcg pointer.
2004 * But in this case, we keep res->usage until end of a series of
2005 * uncharges. Then, it's ok to ignore memcg's refcnt.
2010 * In typical case, batch->memcg == mem. This means we can
2011 * merge a series of uncharges to an uncharge of res_counter.
2012 * If not, we uncharge res_counter ony by one.
2014 if (batch
->memcg
!= mem
)
2015 goto direct_uncharge
;
2016 /* remember freed charge and uncharge it later */
2017 batch
->bytes
+= PAGE_SIZE
;
2019 batch
->memsw_bytes
+= PAGE_SIZE
;
2022 res_counter_uncharge(&mem
->res
, PAGE_SIZE
);
2024 res_counter_uncharge(&mem
->memsw
, PAGE_SIZE
);
2029 * uncharge if !page_mapped(page)
2031 static struct mem_cgroup
*
2032 __mem_cgroup_uncharge_common(struct page
*page
, enum charge_type ctype
)
2034 struct page_cgroup
*pc
;
2035 struct mem_cgroup
*mem
= NULL
;
2036 struct mem_cgroup_per_zone
*mz
;
2038 if (mem_cgroup_disabled())
2041 if (PageSwapCache(page
))
2045 * Check if our page_cgroup is valid
2047 pc
= lookup_page_cgroup(page
);
2048 if (unlikely(!pc
|| !PageCgroupUsed(pc
)))
2051 lock_page_cgroup(pc
);
2053 mem
= pc
->mem_cgroup
;
2055 if (!PageCgroupUsed(pc
))
2059 case MEM_CGROUP_CHARGE_TYPE_MAPPED
:
2060 case MEM_CGROUP_CHARGE_TYPE_DROP
:
2061 if (page_mapped(page
))
2064 case MEM_CGROUP_CHARGE_TYPE_SWAPOUT
:
2065 if (!PageAnon(page
)) { /* Shared memory */
2066 if (page
->mapping
&& !page_is_file_cache(page
))
2068 } else if (page_mapped(page
)) /* Anon */
2075 if (!mem_cgroup_is_root(mem
))
2076 __do_uncharge(mem
, ctype
);
2077 if (ctype
== MEM_CGROUP_CHARGE_TYPE_SWAPOUT
)
2078 mem_cgroup_swap_statistics(mem
, true);
2079 mem_cgroup_charge_statistics(mem
, pc
, false);
2081 ClearPageCgroupUsed(pc
);
2083 * pc->mem_cgroup is not cleared here. It will be accessed when it's
2084 * freed from LRU. This is safe because uncharged page is expected not
2085 * to be reused (freed soon). Exception is SwapCache, it's handled by
2086 * special functions.
2089 mz
= page_cgroup_zoneinfo(pc
);
2090 unlock_page_cgroup(pc
);
2092 if (mem_cgroup_soft_limit_check(mem
))
2093 mem_cgroup_update_tree(mem
, page
);
2094 /* at swapout, this memcg will be accessed to record to swap */
2095 if (ctype
!= MEM_CGROUP_CHARGE_TYPE_SWAPOUT
)
2101 unlock_page_cgroup(pc
);
2105 void mem_cgroup_uncharge_page(struct page
*page
)
2108 if (page_mapped(page
))
2110 if (page
->mapping
&& !PageAnon(page
))
2112 __mem_cgroup_uncharge_common(page
, MEM_CGROUP_CHARGE_TYPE_MAPPED
);
2115 void mem_cgroup_uncharge_cache_page(struct page
*page
)
2117 VM_BUG_ON(page_mapped(page
));
2118 VM_BUG_ON(page
->mapping
);
2119 __mem_cgroup_uncharge_common(page
, MEM_CGROUP_CHARGE_TYPE_CACHE
);
2123 * Batch_start/batch_end is called in unmap_page_range/invlidate/trucate.
2124 * In that cases, pages are freed continuously and we can expect pages
2125 * are in the same memcg. All these calls itself limits the number of
2126 * pages freed at once, then uncharge_start/end() is called properly.
2127 * This may be called prural(2) times in a context,
2130 void mem_cgroup_uncharge_start(void)
2132 current
->memcg_batch
.do_batch
++;
2133 /* We can do nest. */
2134 if (current
->memcg_batch
.do_batch
== 1) {
2135 current
->memcg_batch
.memcg
= NULL
;
2136 current
->memcg_batch
.bytes
= 0;
2137 current
->memcg_batch
.memsw_bytes
= 0;
2141 void mem_cgroup_uncharge_end(void)
2143 struct memcg_batch_info
*batch
= ¤t
->memcg_batch
;
2145 if (!batch
->do_batch
)
2149 if (batch
->do_batch
) /* If stacked, do nothing. */
2155 * This "batch->memcg" is valid without any css_get/put etc...
2156 * bacause we hide charges behind us.
2159 res_counter_uncharge(&batch
->memcg
->res
, batch
->bytes
);
2160 if (batch
->memsw_bytes
)
2161 res_counter_uncharge(&batch
->memcg
->memsw
, batch
->memsw_bytes
);
2162 /* forget this pointer (for sanity check) */
2163 batch
->memcg
= NULL
;
2168 * called after __delete_from_swap_cache() and drop "page" account.
2169 * memcg information is recorded to swap_cgroup of "ent"
2172 mem_cgroup_uncharge_swapcache(struct page
*page
, swp_entry_t ent
, bool swapout
)
2174 struct mem_cgroup
*memcg
;
2175 int ctype
= MEM_CGROUP_CHARGE_TYPE_SWAPOUT
;
2177 if (!swapout
) /* this was a swap cache but the swap is unused ! */
2178 ctype
= MEM_CGROUP_CHARGE_TYPE_DROP
;
2180 memcg
= __mem_cgroup_uncharge_common(page
, ctype
);
2182 /* record memcg information */
2183 if (do_swap_account
&& swapout
&& memcg
) {
2184 swap_cgroup_record(ent
, css_id(&memcg
->css
));
2185 mem_cgroup_get(memcg
);
2187 if (swapout
&& memcg
)
2188 css_put(&memcg
->css
);
2192 #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP
2194 * called from swap_entry_free(). remove record in swap_cgroup and
2195 * uncharge "memsw" account.
2197 void mem_cgroup_uncharge_swap(swp_entry_t ent
)
2199 struct mem_cgroup
*memcg
;
2202 if (!do_swap_account
)
2205 id
= swap_cgroup_record(ent
, 0);
2207 memcg
= mem_cgroup_lookup(id
);
2210 * We uncharge this because swap is freed.
2211 * This memcg can be obsolete one. We avoid calling css_tryget
2213 if (!mem_cgroup_is_root(memcg
))
2214 res_counter_uncharge(&memcg
->memsw
, PAGE_SIZE
);
2215 mem_cgroup_swap_statistics(memcg
, false);
2216 mem_cgroup_put(memcg
);
2223 * Before starting migration, account PAGE_SIZE to mem_cgroup that the old
2226 int mem_cgroup_prepare_migration(struct page
*page
, struct mem_cgroup
**ptr
)
2228 struct page_cgroup
*pc
;
2229 struct mem_cgroup
*mem
= NULL
;
2232 if (mem_cgroup_disabled())
2235 pc
= lookup_page_cgroup(page
);
2236 lock_page_cgroup(pc
);
2237 if (PageCgroupUsed(pc
)) {
2238 mem
= pc
->mem_cgroup
;
2241 unlock_page_cgroup(pc
);
2244 ret
= __mem_cgroup_try_charge(NULL
, GFP_KERNEL
, &mem
, false,
2252 /* remove redundant charge if migration failed*/
2253 void mem_cgroup_end_migration(struct mem_cgroup
*mem
,
2254 struct page
*oldpage
, struct page
*newpage
)
2256 struct page
*target
, *unused
;
2257 struct page_cgroup
*pc
;
2258 enum charge_type ctype
;
2262 cgroup_exclude_rmdir(&mem
->css
);
2263 /* at migration success, oldpage->mapping is NULL. */
2264 if (oldpage
->mapping
) {
2272 if (PageAnon(target
))
2273 ctype
= MEM_CGROUP_CHARGE_TYPE_MAPPED
;
2274 else if (page_is_file_cache(target
))
2275 ctype
= MEM_CGROUP_CHARGE_TYPE_CACHE
;
2277 ctype
= MEM_CGROUP_CHARGE_TYPE_SHMEM
;
2279 /* unused page is not on radix-tree now. */
2281 __mem_cgroup_uncharge_common(unused
, ctype
);
2283 pc
= lookup_page_cgroup(target
);
2285 * __mem_cgroup_commit_charge() check PCG_USED bit of page_cgroup.
2286 * So, double-counting is effectively avoided.
2288 __mem_cgroup_commit_charge(mem
, pc
, ctype
);
2291 * Both of oldpage and newpage are still under lock_page().
2292 * Then, we don't have to care about race in radix-tree.
2293 * But we have to be careful that this page is unmapped or not.
2295 * There is a case for !page_mapped(). At the start of
2296 * migration, oldpage was mapped. But now, it's zapped.
2297 * But we know *target* page is not freed/reused under us.
2298 * mem_cgroup_uncharge_page() does all necessary checks.
2300 if (ctype
== MEM_CGROUP_CHARGE_TYPE_MAPPED
)
2301 mem_cgroup_uncharge_page(target
);
2303 * At migration, we may charge account against cgroup which has no tasks
2304 * So, rmdir()->pre_destroy() can be called while we do this charge.
2305 * In that case, we need to call pre_destroy() again. check it here.
2307 cgroup_release_and_wakeup_rmdir(&mem
->css
);
2311 * A call to try to shrink memory usage on charge failure at shmem's swapin.
2312 * Calling hierarchical_reclaim is not enough because we should update
2313 * last_oom_jiffies to prevent pagefault_out_of_memory from invoking global OOM.
2314 * Moreover considering hierarchy, we should reclaim from the mem_over_limit,
2315 * not from the memcg which this page would be charged to.
2316 * try_charge_swapin does all of these works properly.
2318 int mem_cgroup_shmem_charge_fallback(struct page
*page
,
2319 struct mm_struct
*mm
,
2322 struct mem_cgroup
*mem
= NULL
;
2325 if (mem_cgroup_disabled())
2328 ret
= mem_cgroup_try_charge_swapin(mm
, page
, gfp_mask
, &mem
);
2330 mem_cgroup_cancel_charge_swapin(mem
); /* it does !mem check */
2335 static DEFINE_MUTEX(set_limit_mutex
);
2337 static int mem_cgroup_resize_limit(struct mem_cgroup
*memcg
,
2338 unsigned long long val
)
2343 int children
= mem_cgroup_count_children(memcg
);
2344 u64 curusage
, oldusage
;
2347 * For keeping hierarchical_reclaim simple, how long we should retry
2348 * is depends on callers. We set our retry-count to be function
2349 * of # of children which we should visit in this loop.
2351 retry_count
= MEM_CGROUP_RECLAIM_RETRIES
* children
;
2353 oldusage
= res_counter_read_u64(&memcg
->res
, RES_USAGE
);
2355 while (retry_count
) {
2356 if (signal_pending(current
)) {
2361 * Rather than hide all in some function, I do this in
2362 * open coded manner. You see what this really does.
2363 * We have to guarantee mem->res.limit < mem->memsw.limit.
2365 mutex_lock(&set_limit_mutex
);
2366 memswlimit
= res_counter_read_u64(&memcg
->memsw
, RES_LIMIT
);
2367 if (memswlimit
< val
) {
2369 mutex_unlock(&set_limit_mutex
);
2372 ret
= res_counter_set_limit(&memcg
->res
, val
);
2374 if (memswlimit
== val
)
2375 memcg
->memsw_is_minimum
= true;
2377 memcg
->memsw_is_minimum
= false;
2379 mutex_unlock(&set_limit_mutex
);
2384 mem_cgroup_hierarchical_reclaim(memcg
, NULL
, GFP_KERNEL
,
2385 MEM_CGROUP_RECLAIM_SHRINK
);
2386 curusage
= res_counter_read_u64(&memcg
->res
, RES_USAGE
);
2387 /* Usage is reduced ? */
2388 if (curusage
>= oldusage
)
2391 oldusage
= curusage
;
2397 static int mem_cgroup_resize_memsw_limit(struct mem_cgroup
*memcg
,
2398 unsigned long long val
)
2401 u64 memlimit
, oldusage
, curusage
;
2402 int children
= mem_cgroup_count_children(memcg
);
2405 /* see mem_cgroup_resize_res_limit */
2406 retry_count
= children
* MEM_CGROUP_RECLAIM_RETRIES
;
2407 oldusage
= res_counter_read_u64(&memcg
->memsw
, RES_USAGE
);
2408 while (retry_count
) {
2409 if (signal_pending(current
)) {
2414 * Rather than hide all in some function, I do this in
2415 * open coded manner. You see what this really does.
2416 * We have to guarantee mem->res.limit < mem->memsw.limit.
2418 mutex_lock(&set_limit_mutex
);
2419 memlimit
= res_counter_read_u64(&memcg
->res
, RES_LIMIT
);
2420 if (memlimit
> val
) {
2422 mutex_unlock(&set_limit_mutex
);
2425 ret
= res_counter_set_limit(&memcg
->memsw
, val
);
2427 if (memlimit
== val
)
2428 memcg
->memsw_is_minimum
= true;
2430 memcg
->memsw_is_minimum
= false;
2432 mutex_unlock(&set_limit_mutex
);
2437 mem_cgroup_hierarchical_reclaim(memcg
, NULL
, GFP_KERNEL
,
2438 MEM_CGROUP_RECLAIM_NOSWAP
|
2439 MEM_CGROUP_RECLAIM_SHRINK
);
2440 curusage
= res_counter_read_u64(&memcg
->memsw
, RES_USAGE
);
2441 /* Usage is reduced ? */
2442 if (curusage
>= oldusage
)
2445 oldusage
= curusage
;
2450 unsigned long mem_cgroup_soft_limit_reclaim(struct zone
*zone
, int order
,
2451 gfp_t gfp_mask
, int nid
,
2454 unsigned long nr_reclaimed
= 0;
2455 struct mem_cgroup_per_zone
*mz
, *next_mz
= NULL
;
2456 unsigned long reclaimed
;
2458 struct mem_cgroup_tree_per_zone
*mctz
;
2459 unsigned long long excess
;
2464 mctz
= soft_limit_tree_node_zone(nid
, zid
);
2466 * This loop can run a while, specially if mem_cgroup's continuously
2467 * keep exceeding their soft limit and putting the system under
2474 mz
= mem_cgroup_largest_soft_limit_node(mctz
);
2478 reclaimed
= mem_cgroup_hierarchical_reclaim(mz
->mem
, zone
,
2480 MEM_CGROUP_RECLAIM_SOFT
);
2481 nr_reclaimed
+= reclaimed
;
2482 spin_lock(&mctz
->lock
);
2485 * If we failed to reclaim anything from this memory cgroup
2486 * it is time to move on to the next cgroup
2492 * Loop until we find yet another one.
2494 * By the time we get the soft_limit lock
2495 * again, someone might have aded the
2496 * group back on the RB tree. Iterate to
2497 * make sure we get a different mem.
2498 * mem_cgroup_largest_soft_limit_node returns
2499 * NULL if no other cgroup is present on
2503 __mem_cgroup_largest_soft_limit_node(mctz
);
2504 if (next_mz
== mz
) {
2505 css_put(&next_mz
->mem
->css
);
2507 } else /* next_mz == NULL or other memcg */
2511 __mem_cgroup_remove_exceeded(mz
->mem
, mz
, mctz
);
2512 excess
= res_counter_soft_limit_excess(&mz
->mem
->res
);
2514 * One school of thought says that we should not add
2515 * back the node to the tree if reclaim returns 0.
2516 * But our reclaim could return 0, simply because due
2517 * to priority we are exposing a smaller subset of
2518 * memory to reclaim from. Consider this as a longer
2521 /* If excess == 0, no tree ops */
2522 __mem_cgroup_insert_exceeded(mz
->mem
, mz
, mctz
, excess
);
2523 spin_unlock(&mctz
->lock
);
2524 css_put(&mz
->mem
->css
);
2527 * Could not reclaim anything and there are no more
2528 * mem cgroups to try or we seem to be looping without
2529 * reclaiming anything.
2531 if (!nr_reclaimed
&&
2533 loop
> MEM_CGROUP_MAX_SOFT_LIMIT_RECLAIM_LOOPS
))
2535 } while (!nr_reclaimed
);
2537 css_put(&next_mz
->mem
->css
);
2538 return nr_reclaimed
;
2542 * This routine traverse page_cgroup in given list and drop them all.
2543 * *And* this routine doesn't reclaim page itself, just removes page_cgroup.
2545 static int mem_cgroup_force_empty_list(struct mem_cgroup
*mem
,
2546 int node
, int zid
, enum lru_list lru
)
2549 struct mem_cgroup_per_zone
*mz
;
2550 struct page_cgroup
*pc
, *busy
;
2551 unsigned long flags
, loop
;
2552 struct list_head
*list
;
2555 zone
= &NODE_DATA(node
)->node_zones
[zid
];
2556 mz
= mem_cgroup_zoneinfo(mem
, node
, zid
);
2557 list
= &mz
->lists
[lru
];
2559 loop
= MEM_CGROUP_ZSTAT(mz
, lru
);
2560 /* give some margin against EBUSY etc...*/
2565 spin_lock_irqsave(&zone
->lru_lock
, flags
);
2566 if (list_empty(list
)) {
2567 spin_unlock_irqrestore(&zone
->lru_lock
, flags
);
2570 pc
= list_entry(list
->prev
, struct page_cgroup
, lru
);
2572 list_move(&pc
->lru
, list
);
2574 spin_unlock_irqrestore(&zone
->lru_lock
, flags
);
2577 spin_unlock_irqrestore(&zone
->lru_lock
, flags
);
2579 ret
= mem_cgroup_move_parent(pc
, mem
, GFP_KERNEL
);
2583 if (ret
== -EBUSY
|| ret
== -EINVAL
) {
2584 /* found lock contention or "pc" is obsolete. */
2591 if (!ret
&& !list_empty(list
))
2597 * make mem_cgroup's charge to be 0 if there is no task.
2598 * This enables deleting this mem_cgroup.
2600 static int mem_cgroup_force_empty(struct mem_cgroup
*mem
, bool free_all
)
2603 int node
, zid
, shrink
;
2604 int nr_retries
= MEM_CGROUP_RECLAIM_RETRIES
;
2605 struct cgroup
*cgrp
= mem
->css
.cgroup
;
2610 /* should free all ? */
2616 if (cgroup_task_count(cgrp
) || !list_empty(&cgrp
->children
))
2619 if (signal_pending(current
))
2621 /* This is for making all *used* pages to be on LRU. */
2622 lru_add_drain_all();
2623 drain_all_stock_sync();
2625 for_each_node_state(node
, N_HIGH_MEMORY
) {
2626 for (zid
= 0; !ret
&& zid
< MAX_NR_ZONES
; zid
++) {
2629 ret
= mem_cgroup_force_empty_list(mem
,
2638 /* it seems parent cgroup doesn't have enough mem */
2642 /* "ret" should also be checked to ensure all lists are empty. */
2643 } while (mem
->res
.usage
> 0 || ret
);
2649 /* returns EBUSY if there is a task or if we come here twice. */
2650 if (cgroup_task_count(cgrp
) || !list_empty(&cgrp
->children
) || shrink
) {
2654 /* we call try-to-free pages for make this cgroup empty */
2655 lru_add_drain_all();
2656 /* try to free all pages in this cgroup */
2658 while (nr_retries
&& mem
->res
.usage
> 0) {
2661 if (signal_pending(current
)) {
2665 progress
= try_to_free_mem_cgroup_pages(mem
, GFP_KERNEL
,
2666 false, get_swappiness(mem
));
2669 /* maybe some writeback is necessary */
2670 congestion_wait(BLK_RW_ASYNC
, HZ
/10);
2675 /* try move_account...there may be some *locked* pages. */
2679 int mem_cgroup_force_empty_write(struct cgroup
*cont
, unsigned int event
)
2681 return mem_cgroup_force_empty(mem_cgroup_from_cont(cont
), true);
2685 static u64
mem_cgroup_hierarchy_read(struct cgroup
*cont
, struct cftype
*cft
)
2687 return mem_cgroup_from_cont(cont
)->use_hierarchy
;
2690 static int mem_cgroup_hierarchy_write(struct cgroup
*cont
, struct cftype
*cft
,
2694 struct mem_cgroup
*mem
= mem_cgroup_from_cont(cont
);
2695 struct cgroup
*parent
= cont
->parent
;
2696 struct mem_cgroup
*parent_mem
= NULL
;
2699 parent_mem
= mem_cgroup_from_cont(parent
);
2703 * If parent's use_hierarchy is set, we can't make any modifications
2704 * in the child subtrees. If it is unset, then the change can
2705 * occur, provided the current cgroup has no children.
2707 * For the root cgroup, parent_mem is NULL, we allow value to be
2708 * set if there are no children.
2710 if ((!parent_mem
|| !parent_mem
->use_hierarchy
) &&
2711 (val
== 1 || val
== 0)) {
2712 if (list_empty(&cont
->children
))
2713 mem
->use_hierarchy
= val
;
2723 struct mem_cgroup_idx_data
{
2725 enum mem_cgroup_stat_index idx
;
2729 mem_cgroup_get_idx_stat(struct mem_cgroup
*mem
, void *data
)
2731 struct mem_cgroup_idx_data
*d
= data
;
2732 d
->val
+= mem_cgroup_read_stat(&mem
->stat
, d
->idx
);
2737 mem_cgroup_get_recursive_idx_stat(struct mem_cgroup
*mem
,
2738 enum mem_cgroup_stat_index idx
, s64
*val
)
2740 struct mem_cgroup_idx_data d
;
2743 mem_cgroup_walk_tree(mem
, &d
, mem_cgroup_get_idx_stat
);
2747 static u64
mem_cgroup_read(struct cgroup
*cont
, struct cftype
*cft
)
2749 struct mem_cgroup
*mem
= mem_cgroup_from_cont(cont
);
2753 type
= MEMFILE_TYPE(cft
->private);
2754 name
= MEMFILE_ATTR(cft
->private);
2757 if (name
== RES_USAGE
&& mem_cgroup_is_root(mem
)) {
2758 mem_cgroup_get_recursive_idx_stat(mem
,
2759 MEM_CGROUP_STAT_CACHE
, &idx_val
);
2761 mem_cgroup_get_recursive_idx_stat(mem
,
2762 MEM_CGROUP_STAT_RSS
, &idx_val
);
2766 val
= res_counter_read_u64(&mem
->res
, name
);
2769 if (name
== RES_USAGE
&& mem_cgroup_is_root(mem
)) {
2770 mem_cgroup_get_recursive_idx_stat(mem
,
2771 MEM_CGROUP_STAT_CACHE
, &idx_val
);
2773 mem_cgroup_get_recursive_idx_stat(mem
,
2774 MEM_CGROUP_STAT_RSS
, &idx_val
);
2776 mem_cgroup_get_recursive_idx_stat(mem
,
2777 MEM_CGROUP_STAT_SWAPOUT
, &idx_val
);
2781 val
= res_counter_read_u64(&mem
->memsw
, name
);
2790 * The user of this function is...
2793 static int mem_cgroup_write(struct cgroup
*cont
, struct cftype
*cft
,
2796 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cont
);
2798 unsigned long long val
;
2801 type
= MEMFILE_TYPE(cft
->private);
2802 name
= MEMFILE_ATTR(cft
->private);
2805 if (mem_cgroup_is_root(memcg
)) { /* Can't set limit on root */
2809 /* This function does all necessary parse...reuse it */
2810 ret
= res_counter_memparse_write_strategy(buffer
, &val
);
2814 ret
= mem_cgroup_resize_limit(memcg
, val
);
2816 ret
= mem_cgroup_resize_memsw_limit(memcg
, val
);
2818 case RES_SOFT_LIMIT
:
2819 ret
= res_counter_memparse_write_strategy(buffer
, &val
);
2823 * For memsw, soft limits are hard to implement in terms
2824 * of semantics, for now, we support soft limits for
2825 * control without swap
2828 ret
= res_counter_set_soft_limit(&memcg
->res
, val
);
2833 ret
= -EINVAL
; /* should be BUG() ? */
2839 static void memcg_get_hierarchical_limit(struct mem_cgroup
*memcg
,
2840 unsigned long long *mem_limit
, unsigned long long *memsw_limit
)
2842 struct cgroup
*cgroup
;
2843 unsigned long long min_limit
, min_memsw_limit
, tmp
;
2845 min_limit
= res_counter_read_u64(&memcg
->res
, RES_LIMIT
);
2846 min_memsw_limit
= res_counter_read_u64(&memcg
->memsw
, RES_LIMIT
);
2847 cgroup
= memcg
->css
.cgroup
;
2848 if (!memcg
->use_hierarchy
)
2851 while (cgroup
->parent
) {
2852 cgroup
= cgroup
->parent
;
2853 memcg
= mem_cgroup_from_cont(cgroup
);
2854 if (!memcg
->use_hierarchy
)
2856 tmp
= res_counter_read_u64(&memcg
->res
, RES_LIMIT
);
2857 min_limit
= min(min_limit
, tmp
);
2858 tmp
= res_counter_read_u64(&memcg
->memsw
, RES_LIMIT
);
2859 min_memsw_limit
= min(min_memsw_limit
, tmp
);
2862 *mem_limit
= min_limit
;
2863 *memsw_limit
= min_memsw_limit
;
2867 static int mem_cgroup_reset(struct cgroup
*cont
, unsigned int event
)
2869 struct mem_cgroup
*mem
;
2872 mem
= mem_cgroup_from_cont(cont
);
2873 type
= MEMFILE_TYPE(event
);
2874 name
= MEMFILE_ATTR(event
);
2878 res_counter_reset_max(&mem
->res
);
2880 res_counter_reset_max(&mem
->memsw
);
2884 res_counter_reset_failcnt(&mem
->res
);
2886 res_counter_reset_failcnt(&mem
->memsw
);
2893 static u64
mem_cgroup_move_charge_read(struct cgroup
*cgrp
,
2896 return mem_cgroup_from_cont(cgrp
)->move_charge_at_immigrate
;
2899 static int mem_cgroup_move_charge_write(struct cgroup
*cgrp
,
2900 struct cftype
*cft
, u64 val
)
2902 struct mem_cgroup
*mem
= mem_cgroup_from_cont(cgrp
);
2904 if (val
>= (1 << NR_MOVE_TYPE
))
2907 * We check this value several times in both in can_attach() and
2908 * attach(), so we need cgroup lock to prevent this value from being
2912 mem
->move_charge_at_immigrate
= val
;
2919 /* For read statistics */
2935 struct mcs_total_stat
{
2936 s64 stat
[NR_MCS_STAT
];
2942 } memcg_stat_strings
[NR_MCS_STAT
] = {
2943 {"cache", "total_cache"},
2944 {"rss", "total_rss"},
2945 {"mapped_file", "total_mapped_file"},
2946 {"pgpgin", "total_pgpgin"},
2947 {"pgpgout", "total_pgpgout"},
2948 {"swap", "total_swap"},
2949 {"inactive_anon", "total_inactive_anon"},
2950 {"active_anon", "total_active_anon"},
2951 {"inactive_file", "total_inactive_file"},
2952 {"active_file", "total_active_file"},
2953 {"unevictable", "total_unevictable"}
2957 static int mem_cgroup_get_local_stat(struct mem_cgroup
*mem
, void *data
)
2959 struct mcs_total_stat
*s
= data
;
2963 val
= mem_cgroup_read_stat(&mem
->stat
, MEM_CGROUP_STAT_CACHE
);
2964 s
->stat
[MCS_CACHE
] += val
* PAGE_SIZE
;
2965 val
= mem_cgroup_read_stat(&mem
->stat
, MEM_CGROUP_STAT_RSS
);
2966 s
->stat
[MCS_RSS
] += val
* PAGE_SIZE
;
2967 val
= mem_cgroup_read_stat(&mem
->stat
, MEM_CGROUP_STAT_FILE_MAPPED
);
2968 s
->stat
[MCS_FILE_MAPPED
] += val
* PAGE_SIZE
;
2969 val
= mem_cgroup_read_stat(&mem
->stat
, MEM_CGROUP_STAT_PGPGIN_COUNT
);
2970 s
->stat
[MCS_PGPGIN
] += val
;
2971 val
= mem_cgroup_read_stat(&mem
->stat
, MEM_CGROUP_STAT_PGPGOUT_COUNT
);
2972 s
->stat
[MCS_PGPGOUT
] += val
;
2973 if (do_swap_account
) {
2974 val
= mem_cgroup_read_stat(&mem
->stat
, MEM_CGROUP_STAT_SWAPOUT
);
2975 s
->stat
[MCS_SWAP
] += val
* PAGE_SIZE
;
2979 val
= mem_cgroup_get_local_zonestat(mem
, LRU_INACTIVE_ANON
);
2980 s
->stat
[MCS_INACTIVE_ANON
] += val
* PAGE_SIZE
;
2981 val
= mem_cgroup_get_local_zonestat(mem
, LRU_ACTIVE_ANON
);
2982 s
->stat
[MCS_ACTIVE_ANON
] += val
* PAGE_SIZE
;
2983 val
= mem_cgroup_get_local_zonestat(mem
, LRU_INACTIVE_FILE
);
2984 s
->stat
[MCS_INACTIVE_FILE
] += val
* PAGE_SIZE
;
2985 val
= mem_cgroup_get_local_zonestat(mem
, LRU_ACTIVE_FILE
);
2986 s
->stat
[MCS_ACTIVE_FILE
] += val
* PAGE_SIZE
;
2987 val
= mem_cgroup_get_local_zonestat(mem
, LRU_UNEVICTABLE
);
2988 s
->stat
[MCS_UNEVICTABLE
] += val
* PAGE_SIZE
;
2993 mem_cgroup_get_total_stat(struct mem_cgroup
*mem
, struct mcs_total_stat
*s
)
2995 mem_cgroup_walk_tree(mem
, s
, mem_cgroup_get_local_stat
);
2998 static int mem_control_stat_show(struct cgroup
*cont
, struct cftype
*cft
,
2999 struct cgroup_map_cb
*cb
)
3001 struct mem_cgroup
*mem_cont
= mem_cgroup_from_cont(cont
);
3002 struct mcs_total_stat mystat
;
3005 memset(&mystat
, 0, sizeof(mystat
));
3006 mem_cgroup_get_local_stat(mem_cont
, &mystat
);
3008 for (i
= 0; i
< NR_MCS_STAT
; i
++) {
3009 if (i
== MCS_SWAP
&& !do_swap_account
)
3011 cb
->fill(cb
, memcg_stat_strings
[i
].local_name
, mystat
.stat
[i
]);
3014 /* Hierarchical information */
3016 unsigned long long limit
, memsw_limit
;
3017 memcg_get_hierarchical_limit(mem_cont
, &limit
, &memsw_limit
);
3018 cb
->fill(cb
, "hierarchical_memory_limit", limit
);
3019 if (do_swap_account
)
3020 cb
->fill(cb
, "hierarchical_memsw_limit", memsw_limit
);
3023 memset(&mystat
, 0, sizeof(mystat
));
3024 mem_cgroup_get_total_stat(mem_cont
, &mystat
);
3025 for (i
= 0; i
< NR_MCS_STAT
; i
++) {
3026 if (i
== MCS_SWAP
&& !do_swap_account
)
3028 cb
->fill(cb
, memcg_stat_strings
[i
].total_name
, mystat
.stat
[i
]);
3031 #ifdef CONFIG_DEBUG_VM
3032 cb
->fill(cb
, "inactive_ratio", calc_inactive_ratio(mem_cont
, NULL
));
3036 struct mem_cgroup_per_zone
*mz
;
3037 unsigned long recent_rotated
[2] = {0, 0};
3038 unsigned long recent_scanned
[2] = {0, 0};
3040 for_each_online_node(nid
)
3041 for (zid
= 0; zid
< MAX_NR_ZONES
; zid
++) {
3042 mz
= mem_cgroup_zoneinfo(mem_cont
, nid
, zid
);
3044 recent_rotated
[0] +=
3045 mz
->reclaim_stat
.recent_rotated
[0];
3046 recent_rotated
[1] +=
3047 mz
->reclaim_stat
.recent_rotated
[1];
3048 recent_scanned
[0] +=
3049 mz
->reclaim_stat
.recent_scanned
[0];
3050 recent_scanned
[1] +=
3051 mz
->reclaim_stat
.recent_scanned
[1];
3053 cb
->fill(cb
, "recent_rotated_anon", recent_rotated
[0]);
3054 cb
->fill(cb
, "recent_rotated_file", recent_rotated
[1]);
3055 cb
->fill(cb
, "recent_scanned_anon", recent_scanned
[0]);
3056 cb
->fill(cb
, "recent_scanned_file", recent_scanned
[1]);
3063 static u64
mem_cgroup_swappiness_read(struct cgroup
*cgrp
, struct cftype
*cft
)
3065 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cgrp
);
3067 return get_swappiness(memcg
);
3070 static int mem_cgroup_swappiness_write(struct cgroup
*cgrp
, struct cftype
*cft
,
3073 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cgrp
);
3074 struct mem_cgroup
*parent
;
3079 if (cgrp
->parent
== NULL
)
3082 parent
= mem_cgroup_from_cont(cgrp
->parent
);
3086 /* If under hierarchy, only empty-root can set this value */
3087 if ((parent
->use_hierarchy
) ||
3088 (memcg
->use_hierarchy
&& !list_empty(&cgrp
->children
))) {
3093 spin_lock(&memcg
->reclaim_param_lock
);
3094 memcg
->swappiness
= val
;
3095 spin_unlock(&memcg
->reclaim_param_lock
);
3103 static struct cftype mem_cgroup_files
[] = {
3105 .name
= "usage_in_bytes",
3106 .private = MEMFILE_PRIVATE(_MEM
, RES_USAGE
),
3107 .read_u64
= mem_cgroup_read
,
3110 .name
= "max_usage_in_bytes",
3111 .private = MEMFILE_PRIVATE(_MEM
, RES_MAX_USAGE
),
3112 .trigger
= mem_cgroup_reset
,
3113 .read_u64
= mem_cgroup_read
,
3116 .name
= "limit_in_bytes",
3117 .private = MEMFILE_PRIVATE(_MEM
, RES_LIMIT
),
3118 .write_string
= mem_cgroup_write
,
3119 .read_u64
= mem_cgroup_read
,
3122 .name
= "soft_limit_in_bytes",
3123 .private = MEMFILE_PRIVATE(_MEM
, RES_SOFT_LIMIT
),
3124 .write_string
= mem_cgroup_write
,
3125 .read_u64
= mem_cgroup_read
,
3129 .private = MEMFILE_PRIVATE(_MEM
, RES_FAILCNT
),
3130 .trigger
= mem_cgroup_reset
,
3131 .read_u64
= mem_cgroup_read
,
3135 .read_map
= mem_control_stat_show
,
3138 .name
= "force_empty",
3139 .trigger
= mem_cgroup_force_empty_write
,
3142 .name
= "use_hierarchy",
3143 .write_u64
= mem_cgroup_hierarchy_write
,
3144 .read_u64
= mem_cgroup_hierarchy_read
,
3147 .name
= "swappiness",
3148 .read_u64
= mem_cgroup_swappiness_read
,
3149 .write_u64
= mem_cgroup_swappiness_write
,
3152 .name
= "move_charge_at_immigrate",
3153 .read_u64
= mem_cgroup_move_charge_read
,
3154 .write_u64
= mem_cgroup_move_charge_write
,
3158 #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP
3159 static struct cftype memsw_cgroup_files
[] = {
3161 .name
= "memsw.usage_in_bytes",
3162 .private = MEMFILE_PRIVATE(_MEMSWAP
, RES_USAGE
),
3163 .read_u64
= mem_cgroup_read
,
3166 .name
= "memsw.max_usage_in_bytes",
3167 .private = MEMFILE_PRIVATE(_MEMSWAP
, RES_MAX_USAGE
),
3168 .trigger
= mem_cgroup_reset
,
3169 .read_u64
= mem_cgroup_read
,
3172 .name
= "memsw.limit_in_bytes",
3173 .private = MEMFILE_PRIVATE(_MEMSWAP
, RES_LIMIT
),
3174 .write_string
= mem_cgroup_write
,
3175 .read_u64
= mem_cgroup_read
,
3178 .name
= "memsw.failcnt",
3179 .private = MEMFILE_PRIVATE(_MEMSWAP
, RES_FAILCNT
),
3180 .trigger
= mem_cgroup_reset
,
3181 .read_u64
= mem_cgroup_read
,
3185 static int register_memsw_files(struct cgroup
*cont
, struct cgroup_subsys
*ss
)
3187 if (!do_swap_account
)
3189 return cgroup_add_files(cont
, ss
, memsw_cgroup_files
,
3190 ARRAY_SIZE(memsw_cgroup_files
));
3193 static int register_memsw_files(struct cgroup
*cont
, struct cgroup_subsys
*ss
)
3199 static int alloc_mem_cgroup_per_zone_info(struct mem_cgroup
*mem
, int node
)
3201 struct mem_cgroup_per_node
*pn
;
3202 struct mem_cgroup_per_zone
*mz
;
3204 int zone
, tmp
= node
;
3206 * This routine is called against possible nodes.
3207 * But it's BUG to call kmalloc() against offline node.
3209 * TODO: this routine can waste much memory for nodes which will
3210 * never be onlined. It's better to use memory hotplug callback
3213 if (!node_state(node
, N_NORMAL_MEMORY
))
3215 pn
= kmalloc_node(sizeof(*pn
), GFP_KERNEL
, tmp
);
3219 mem
->info
.nodeinfo
[node
] = pn
;
3220 memset(pn
, 0, sizeof(*pn
));
3222 for (zone
= 0; zone
< MAX_NR_ZONES
; zone
++) {
3223 mz
= &pn
->zoneinfo
[zone
];
3225 INIT_LIST_HEAD(&mz
->lists
[l
]);
3226 mz
->usage_in_excess
= 0;
3227 mz
->on_tree
= false;
3233 static void free_mem_cgroup_per_zone_info(struct mem_cgroup
*mem
, int node
)
3235 kfree(mem
->info
.nodeinfo
[node
]);
3238 static int mem_cgroup_size(void)
3240 int cpustat_size
= nr_cpu_ids
* sizeof(struct mem_cgroup_stat_cpu
);
3241 return sizeof(struct mem_cgroup
) + cpustat_size
;
3244 static struct mem_cgroup
*mem_cgroup_alloc(void)
3246 struct mem_cgroup
*mem
;
3247 int size
= mem_cgroup_size();
3249 if (size
< PAGE_SIZE
)
3250 mem
= kmalloc(size
, GFP_KERNEL
);
3252 mem
= vmalloc(size
);
3255 memset(mem
, 0, size
);
3260 * At destroying mem_cgroup, references from swap_cgroup can remain.
3261 * (scanning all at force_empty is too costly...)
3263 * Instead of clearing all references at force_empty, we remember
3264 * the number of reference from swap_cgroup and free mem_cgroup when
3265 * it goes down to 0.
3267 * Removal of cgroup itself succeeds regardless of refs from swap.
3270 static void __mem_cgroup_free(struct mem_cgroup
*mem
)
3274 mem_cgroup_remove_from_trees(mem
);
3275 free_css_id(&mem_cgroup_subsys
, &mem
->css
);
3277 for_each_node_state(node
, N_POSSIBLE
)
3278 free_mem_cgroup_per_zone_info(mem
, node
);
3280 if (mem_cgroup_size() < PAGE_SIZE
)
3286 static void mem_cgroup_get(struct mem_cgroup
*mem
)
3288 atomic_inc(&mem
->refcnt
);
3291 static void mem_cgroup_put(struct mem_cgroup
*mem
)
3293 if (atomic_dec_and_test(&mem
->refcnt
)) {
3294 struct mem_cgroup
*parent
= parent_mem_cgroup(mem
);
3295 __mem_cgroup_free(mem
);
3297 mem_cgroup_put(parent
);
3302 * Returns the parent mem_cgroup in memcgroup hierarchy with hierarchy enabled.
3304 static struct mem_cgroup
*parent_mem_cgroup(struct mem_cgroup
*mem
)
3306 if (!mem
->res
.parent
)
3308 return mem_cgroup_from_res_counter(mem
->res
.parent
, res
);
3311 #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP
3312 static void __init
enable_swap_cgroup(void)
3314 if (!mem_cgroup_disabled() && really_do_swap_account
)
3315 do_swap_account
= 1;
3318 static void __init
enable_swap_cgroup(void)
3323 static int mem_cgroup_soft_limit_tree_init(void)
3325 struct mem_cgroup_tree_per_node
*rtpn
;
3326 struct mem_cgroup_tree_per_zone
*rtpz
;
3327 int tmp
, node
, zone
;
3329 for_each_node_state(node
, N_POSSIBLE
) {
3331 if (!node_state(node
, N_NORMAL_MEMORY
))
3333 rtpn
= kzalloc_node(sizeof(*rtpn
), GFP_KERNEL
, tmp
);
3337 soft_limit_tree
.rb_tree_per_node
[node
] = rtpn
;
3339 for (zone
= 0; zone
< MAX_NR_ZONES
; zone
++) {
3340 rtpz
= &rtpn
->rb_tree_per_zone
[zone
];
3341 rtpz
->rb_root
= RB_ROOT
;
3342 spin_lock_init(&rtpz
->lock
);
3348 static struct cgroup_subsys_state
* __ref
3349 mem_cgroup_create(struct cgroup_subsys
*ss
, struct cgroup
*cont
)
3351 struct mem_cgroup
*mem
, *parent
;
3352 long error
= -ENOMEM
;
3355 mem
= mem_cgroup_alloc();
3357 return ERR_PTR(error
);
3359 for_each_node_state(node
, N_POSSIBLE
)
3360 if (alloc_mem_cgroup_per_zone_info(mem
, node
))
3364 if (cont
->parent
== NULL
) {
3366 enable_swap_cgroup();
3368 root_mem_cgroup
= mem
;
3369 if (mem_cgroup_soft_limit_tree_init())
3371 for_each_possible_cpu(cpu
) {
3372 struct memcg_stock_pcp
*stock
=
3373 &per_cpu(memcg_stock
, cpu
);
3374 INIT_WORK(&stock
->work
, drain_local_stock
);
3376 hotcpu_notifier(memcg_stock_cpu_callback
, 0);
3379 parent
= mem_cgroup_from_cont(cont
->parent
);
3380 mem
->use_hierarchy
= parent
->use_hierarchy
;
3383 if (parent
&& parent
->use_hierarchy
) {
3384 res_counter_init(&mem
->res
, &parent
->res
);
3385 res_counter_init(&mem
->memsw
, &parent
->memsw
);
3387 * We increment refcnt of the parent to ensure that we can
3388 * safely access it on res_counter_charge/uncharge.
3389 * This refcnt will be decremented when freeing this
3390 * mem_cgroup(see mem_cgroup_put).
3392 mem_cgroup_get(parent
);
3394 res_counter_init(&mem
->res
, NULL
);
3395 res_counter_init(&mem
->memsw
, NULL
);
3397 mem
->last_scanned_child
= 0;
3398 spin_lock_init(&mem
->reclaim_param_lock
);
3401 mem
->swappiness
= get_swappiness(parent
);
3402 atomic_set(&mem
->refcnt
, 1);
3403 mem
->move_charge_at_immigrate
= 0;
3406 __mem_cgroup_free(mem
);
3407 root_mem_cgroup
= NULL
;
3408 return ERR_PTR(error
);
3411 static int mem_cgroup_pre_destroy(struct cgroup_subsys
*ss
,
3412 struct cgroup
*cont
)
3414 struct mem_cgroup
*mem
= mem_cgroup_from_cont(cont
);
3416 return mem_cgroup_force_empty(mem
, false);
3419 static void mem_cgroup_destroy(struct cgroup_subsys
*ss
,
3420 struct cgroup
*cont
)
3422 struct mem_cgroup
*mem
= mem_cgroup_from_cont(cont
);
3424 mem_cgroup_put(mem
);
3427 static int mem_cgroup_populate(struct cgroup_subsys
*ss
,
3428 struct cgroup
*cont
)
3432 ret
= cgroup_add_files(cont
, ss
, mem_cgroup_files
,
3433 ARRAY_SIZE(mem_cgroup_files
));
3436 ret
= register_memsw_files(cont
, ss
);
3440 /* Handlers for move charge at task migration. */
3441 static int mem_cgroup_do_precharge(void)
3444 struct mem_cgroup
*mem
= mc
.to
;
3446 ret
= __mem_cgroup_try_charge(NULL
, GFP_KERNEL
, &mem
, false, NULL
);
3455 * is_target_pte_for_mc - check a pte whether it is valid for move charge
3456 * @vma: the vma the pte to be checked belongs
3457 * @addr: the address corresponding to the pte to be checked
3458 * @ptent: the pte to be checked
3459 * @target: the pointer the target page will be stored(can be NULL)
3462 * 0(MC_TARGET_NONE): if the pte is not a target for move charge.
3463 * 1(MC_TARGET_PAGE): if the page corresponding to this pte is a target for
3464 * move charge. if @target is not NULL, the page is stored in target->page
3465 * with extra refcnt got(Callers should handle it).
3467 * Called with pte lock held.
3469 /* We add a new member later. */
3474 /* We add a new type later. */
3475 enum mc_target_type
{
3476 MC_TARGET_NONE
, /* not used */
3480 static int is_target_pte_for_mc(struct vm_area_struct
*vma
,
3481 unsigned long addr
, pte_t ptent
, union mc_target
*target
)
3484 struct page_cgroup
*pc
;
3486 bool move_anon
= test_bit(MOVE_CHARGE_TYPE_ANON
,
3487 &mc
.to
->move_charge_at_immigrate
);
3489 if (!pte_present(ptent
))
3492 page
= vm_normal_page(vma
, addr
, ptent
);
3493 if (!page
|| !page_mapped(page
))
3496 * TODO: We don't move charges of file(including shmem/tmpfs) pages for
3499 if (!move_anon
|| !PageAnon(page
))
3502 * TODO: We don't move charges of shared(used by multiple processes)
3505 if (page_mapcount(page
) > 1)
3507 if (!get_page_unless_zero(page
))
3510 pc
= lookup_page_cgroup(page
);
3512 * Do only loose check w/o page_cgroup lock. mem_cgroup_move_account()
3513 * checks the pc is valid or not under the lock.
3515 if (PageCgroupUsed(pc
) && pc
->mem_cgroup
== mc
.from
) {
3516 ret
= MC_TARGET_PAGE
;
3518 target
->page
= page
;
3521 if (!ret
|| !target
)
3527 static int mem_cgroup_count_precharge_pte_range(pmd_t
*pmd
,
3528 unsigned long addr
, unsigned long end
,
3529 struct mm_walk
*walk
)
3531 struct vm_area_struct
*vma
= walk
->private;
3535 pte
= pte_offset_map_lock(vma
->vm_mm
, pmd
, addr
, &ptl
);
3536 for (; addr
!= end
; pte
++, addr
+= PAGE_SIZE
)
3537 if (is_target_pte_for_mc(vma
, addr
, *pte
, NULL
))
3538 mc
.precharge
++; /* increment precharge temporarily */
3539 pte_unmap_unlock(pte
- 1, ptl
);
3545 static unsigned long mem_cgroup_count_precharge(struct mm_struct
*mm
)
3547 unsigned long precharge
;
3548 struct vm_area_struct
*vma
;
3550 down_read(&mm
->mmap_sem
);
3551 for (vma
= mm
->mmap
; vma
; vma
= vma
->vm_next
) {
3552 struct mm_walk mem_cgroup_count_precharge_walk
= {
3553 .pmd_entry
= mem_cgroup_count_precharge_pte_range
,
3557 if (is_vm_hugetlb_page(vma
))
3559 /* TODO: We don't move charges of shmem/tmpfs pages for now. */
3560 if (vma
->vm_flags
& VM_SHARED
)
3562 walk_page_range(vma
->vm_start
, vma
->vm_end
,
3563 &mem_cgroup_count_precharge_walk
);
3565 up_read(&mm
->mmap_sem
);
3567 precharge
= mc
.precharge
;
3573 #define PRECHARGE_AT_ONCE 256
3574 static int mem_cgroup_precharge_mc(struct mm_struct
*mm
)
3577 int count
= PRECHARGE_AT_ONCE
;
3578 unsigned long precharge
= mem_cgroup_count_precharge(mm
);
3580 while (!ret
&& precharge
--) {
3581 if (signal_pending(current
)) {
3586 count
= PRECHARGE_AT_ONCE
;
3589 ret
= mem_cgroup_do_precharge();
3595 static void mem_cgroup_clear_mc(void)
3597 /* we must uncharge all the leftover precharges from mc.to */
3598 while (mc
.precharge
) {
3599 mem_cgroup_cancel_charge(mc
.to
);
3606 static int mem_cgroup_can_attach(struct cgroup_subsys
*ss
,
3607 struct cgroup
*cgroup
,
3608 struct task_struct
*p
,
3612 struct mem_cgroup
*mem
= mem_cgroup_from_cont(cgroup
);
3614 if (mem
->move_charge_at_immigrate
) {
3615 struct mm_struct
*mm
;
3616 struct mem_cgroup
*from
= mem_cgroup_from_task(p
);
3618 VM_BUG_ON(from
== mem
);
3620 mm
= get_task_mm(p
);
3623 /* We move charges only when we move a owner of the mm */
3624 if (mm
->owner
== p
) {
3627 VM_BUG_ON(mc
.precharge
);
3632 ret
= mem_cgroup_precharge_mc(mm
);
3634 mem_cgroup_clear_mc();
3641 static void mem_cgroup_cancel_attach(struct cgroup_subsys
*ss
,
3642 struct cgroup
*cgroup
,
3643 struct task_struct
*p
,
3646 mem_cgroup_clear_mc();
3649 static int mem_cgroup_move_charge_pte_range(pmd_t
*pmd
,
3650 unsigned long addr
, unsigned long end
,
3651 struct mm_walk
*walk
)
3654 struct vm_area_struct
*vma
= walk
->private;
3659 pte
= pte_offset_map_lock(vma
->vm_mm
, pmd
, addr
, &ptl
);
3660 for (; addr
!= end
; addr
+= PAGE_SIZE
) {
3661 pte_t ptent
= *(pte
++);
3662 union mc_target target
;
3665 struct page_cgroup
*pc
;
3670 type
= is_target_pte_for_mc(vma
, addr
, ptent
, &target
);
3672 case MC_TARGET_PAGE
:
3674 if (isolate_lru_page(page
))
3676 pc
= lookup_page_cgroup(page
);
3677 if (!mem_cgroup_move_account(pc
, mc
.from
, mc
.to
)) {
3678 css_put(&mc
.to
->css
);
3681 putback_lru_page(page
);
3682 put
: /* is_target_pte_for_mc() gets the page */
3689 pte_unmap_unlock(pte
- 1, ptl
);
3694 * We have consumed all precharges we got in can_attach().
3695 * We try charge one by one, but don't do any additional
3696 * charges to mc.to if we have failed in charge once in attach()
3699 ret
= mem_cgroup_do_precharge();
3707 static void mem_cgroup_move_charge(struct mm_struct
*mm
)
3709 struct vm_area_struct
*vma
;
3711 lru_add_drain_all();
3712 down_read(&mm
->mmap_sem
);
3713 for (vma
= mm
->mmap
; vma
; vma
= vma
->vm_next
) {
3715 struct mm_walk mem_cgroup_move_charge_walk
= {
3716 .pmd_entry
= mem_cgroup_move_charge_pte_range
,
3720 if (is_vm_hugetlb_page(vma
))
3722 /* TODO: We don't move charges of shmem/tmpfs pages for now. */
3723 if (vma
->vm_flags
& VM_SHARED
)
3725 ret
= walk_page_range(vma
->vm_start
, vma
->vm_end
,
3726 &mem_cgroup_move_charge_walk
);
3729 * means we have consumed all precharges and failed in
3730 * doing additional charge. Just abandon here.
3734 up_read(&mm
->mmap_sem
);
3737 static void mem_cgroup_move_task(struct cgroup_subsys
*ss
,
3738 struct cgroup
*cont
,
3739 struct cgroup
*old_cont
,
3740 struct task_struct
*p
,
3743 struct mm_struct
*mm
;
3746 /* no need to move charge */
3749 mm
= get_task_mm(p
);
3751 mem_cgroup_move_charge(mm
);
3754 mem_cgroup_clear_mc();
3757 struct cgroup_subsys mem_cgroup_subsys
= {
3759 .subsys_id
= mem_cgroup_subsys_id
,
3760 .create
= mem_cgroup_create
,
3761 .pre_destroy
= mem_cgroup_pre_destroy
,
3762 .destroy
= mem_cgroup_destroy
,
3763 .populate
= mem_cgroup_populate
,
3764 .can_attach
= mem_cgroup_can_attach
,
3765 .cancel_attach
= mem_cgroup_cancel_attach
,
3766 .attach
= mem_cgroup_move_task
,
3771 #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP
3773 static int __init
disable_swap_account(char *s
)
3775 really_do_swap_account
= 0;
3778 __setup("noswapaccount", disable_swap_account
);