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/pagemap.h>
25 #include <linux/smp.h>
26 #include <linux/page-flags.h>
27 #include <linux/backing-dev.h>
28 #include <linux/bit_spinlock.h>
29 #include <linux/rcupdate.h>
30 #include <linux/mutex.h>
31 #include <linux/slab.h>
32 #include <linux/swap.h>
33 #include <linux/spinlock.h>
35 #include <linux/seq_file.h>
36 #include <linux/vmalloc.h>
37 #include <linux/mm_inline.h>
38 #include <linux/page_cgroup.h>
41 #include <asm/uaccess.h>
43 struct cgroup_subsys mem_cgroup_subsys __read_mostly
;
44 #define MEM_CGROUP_RECLAIM_RETRIES 5
46 #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP
47 /* Turned on only when memory cgroup is enabled && really_do_swap_account = 0 */
48 int do_swap_account __read_mostly
;
49 static int really_do_swap_account __initdata
= 1; /* for remember boot option*/
51 #define do_swap_account (0)
54 static DEFINE_MUTEX(memcg_tasklist
); /* can be hold under cgroup_mutex */
57 * Statistics for memory cgroup.
59 enum mem_cgroup_stat_index
{
61 * For MEM_CONTAINER_TYPE_ALL, usage = pagecache + rss.
63 MEM_CGROUP_STAT_CACHE
, /* # of pages charged as cache */
64 MEM_CGROUP_STAT_RSS
, /* # of pages charged as rss */
65 MEM_CGROUP_STAT_PGPGIN_COUNT
, /* # of pages paged in */
66 MEM_CGROUP_STAT_PGPGOUT_COUNT
, /* # of pages paged out */
68 MEM_CGROUP_STAT_NSTATS
,
71 struct mem_cgroup_stat_cpu
{
72 s64 count
[MEM_CGROUP_STAT_NSTATS
];
73 } ____cacheline_aligned_in_smp
;
75 struct mem_cgroup_stat
{
76 struct mem_cgroup_stat_cpu cpustat
[0];
80 * For accounting under irq disable, no need for increment preempt count.
82 static inline void __mem_cgroup_stat_add_safe(struct mem_cgroup_stat_cpu
*stat
,
83 enum mem_cgroup_stat_index idx
, int val
)
85 stat
->count
[idx
] += val
;
88 static s64
mem_cgroup_read_stat(struct mem_cgroup_stat
*stat
,
89 enum mem_cgroup_stat_index idx
)
93 for_each_possible_cpu(cpu
)
94 ret
+= stat
->cpustat
[cpu
].count
[idx
];
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
;
110 /* Macro for accessing counter */
111 #define MEM_CGROUP_ZSTAT(mz, idx) ((mz)->count[(idx)])
113 struct mem_cgroup_per_node
{
114 struct mem_cgroup_per_zone zoneinfo
[MAX_NR_ZONES
];
117 struct mem_cgroup_lru_info
{
118 struct mem_cgroup_per_node
*nodeinfo
[MAX_NUMNODES
];
122 * The memory controller data structure. The memory controller controls both
123 * page cache and RSS per cgroup. We would eventually like to provide
124 * statistics based on the statistics developed by Rik Van Riel for clock-pro,
125 * to help the administrator determine what knobs to tune.
127 * TODO: Add a water mark for the memory controller. Reclaim will begin when
128 * we hit the water mark. May be even add a low water mark, such that
129 * no reclaim occurs from a cgroup at it's low water mark, this is
130 * a feature that will be implemented much later in the future.
133 struct cgroup_subsys_state css
;
135 * the counter to account for memory usage
137 struct res_counter res
;
139 * the counter to account for mem+swap usage.
141 struct res_counter memsw
;
143 * Per cgroup active and inactive list, similar to the
144 * per zone LRU lists.
146 struct mem_cgroup_lru_info info
;
149 protect against reclaim related member.
151 spinlock_t reclaim_param_lock
;
153 int prev_priority
; /* for recording reclaim priority */
156 * While reclaiming in a hiearchy, we cache the last child we
157 * reclaimed from. Protected by cgroup_lock()
159 struct mem_cgroup
*last_scanned_child
;
161 * Should the accounting and control be hierarchical, per subtree?
164 unsigned long last_oom_jiffies
;
168 unsigned int swappiness
;
171 * statistics. This must be placed at the end of memcg.
173 struct mem_cgroup_stat stat
;
177 MEM_CGROUP_CHARGE_TYPE_CACHE
= 0,
178 MEM_CGROUP_CHARGE_TYPE_MAPPED
,
179 MEM_CGROUP_CHARGE_TYPE_SHMEM
, /* used by page migration of shmem */
180 MEM_CGROUP_CHARGE_TYPE_FORCE
, /* used by force_empty */
181 MEM_CGROUP_CHARGE_TYPE_SWAPOUT
, /* for accounting swapcache */
185 /* only for here (for easy reading.) */
186 #define PCGF_CACHE (1UL << PCG_CACHE)
187 #define PCGF_USED (1UL << PCG_USED)
188 #define PCGF_LOCK (1UL << PCG_LOCK)
189 static const unsigned long
190 pcg_default_flags
[NR_CHARGE_TYPE
] = {
191 PCGF_CACHE
| PCGF_USED
| PCGF_LOCK
, /* File Cache */
192 PCGF_USED
| PCGF_LOCK
, /* Anon */
193 PCGF_CACHE
| PCGF_USED
| PCGF_LOCK
, /* Shmem */
197 /* for encoding cft->private value on file */
200 #define MEMFILE_PRIVATE(x, val) (((x) << 16) | (val))
201 #define MEMFILE_TYPE(val) (((val) >> 16) & 0xffff)
202 #define MEMFILE_ATTR(val) ((val) & 0xffff)
204 static void mem_cgroup_get(struct mem_cgroup
*mem
);
205 static void mem_cgroup_put(struct mem_cgroup
*mem
);
207 static void mem_cgroup_charge_statistics(struct mem_cgroup
*mem
,
208 struct page_cgroup
*pc
,
211 int val
= (charge
)? 1 : -1;
212 struct mem_cgroup_stat
*stat
= &mem
->stat
;
213 struct mem_cgroup_stat_cpu
*cpustat
;
216 cpustat
= &stat
->cpustat
[cpu
];
217 if (PageCgroupCache(pc
))
218 __mem_cgroup_stat_add_safe(cpustat
, MEM_CGROUP_STAT_CACHE
, val
);
220 __mem_cgroup_stat_add_safe(cpustat
, MEM_CGROUP_STAT_RSS
, val
);
223 __mem_cgroup_stat_add_safe(cpustat
,
224 MEM_CGROUP_STAT_PGPGIN_COUNT
, 1);
226 __mem_cgroup_stat_add_safe(cpustat
,
227 MEM_CGROUP_STAT_PGPGOUT_COUNT
, 1);
231 static struct mem_cgroup_per_zone
*
232 mem_cgroup_zoneinfo(struct mem_cgroup
*mem
, int nid
, int zid
)
234 return &mem
->info
.nodeinfo
[nid
]->zoneinfo
[zid
];
237 static struct mem_cgroup_per_zone
*
238 page_cgroup_zoneinfo(struct page_cgroup
*pc
)
240 struct mem_cgroup
*mem
= pc
->mem_cgroup
;
241 int nid
= page_cgroup_nid(pc
);
242 int zid
= page_cgroup_zid(pc
);
247 return mem_cgroup_zoneinfo(mem
, nid
, zid
);
250 static unsigned long mem_cgroup_get_all_zonestat(struct mem_cgroup
*mem
,
254 struct mem_cgroup_per_zone
*mz
;
257 for_each_online_node(nid
)
258 for (zid
= 0; zid
< MAX_NR_ZONES
; zid
++) {
259 mz
= mem_cgroup_zoneinfo(mem
, nid
, zid
);
260 total
+= MEM_CGROUP_ZSTAT(mz
, idx
);
265 static struct mem_cgroup
*mem_cgroup_from_cont(struct cgroup
*cont
)
267 return container_of(cgroup_subsys_state(cont
,
268 mem_cgroup_subsys_id
), struct mem_cgroup
,
272 struct mem_cgroup
*mem_cgroup_from_task(struct task_struct
*p
)
275 * mm_update_next_owner() may clear mm->owner to NULL
276 * if it races with swapoff, page migration, etc.
277 * So this can be called with p == NULL.
282 return container_of(task_subsys_state(p
, mem_cgroup_subsys_id
),
283 struct mem_cgroup
, css
);
287 * Following LRU functions are allowed to be used without PCG_LOCK.
288 * Operations are called by routine of global LRU independently from memcg.
289 * What we have to take care of here is validness of pc->mem_cgroup.
291 * Changes to pc->mem_cgroup happens when
294 * In typical case, "charge" is done before add-to-lru. Exception is SwapCache.
295 * It is added to LRU before charge.
296 * If PCG_USED bit is not set, page_cgroup is not added to this private LRU.
297 * When moving account, the page is not on LRU. It's isolated.
300 void mem_cgroup_del_lru_list(struct page
*page
, enum lru_list lru
)
302 struct page_cgroup
*pc
;
303 struct mem_cgroup
*mem
;
304 struct mem_cgroup_per_zone
*mz
;
306 if (mem_cgroup_disabled())
308 pc
= lookup_page_cgroup(page
);
309 /* can happen while we handle swapcache. */
310 if (list_empty(&pc
->lru
))
312 mz
= page_cgroup_zoneinfo(pc
);
313 mem
= pc
->mem_cgroup
;
314 MEM_CGROUP_ZSTAT(mz
, lru
) -= 1;
315 list_del_init(&pc
->lru
);
319 void mem_cgroup_del_lru(struct page
*page
)
321 mem_cgroup_del_lru_list(page
, page_lru(page
));
324 void mem_cgroup_rotate_lru_list(struct page
*page
, enum lru_list lru
)
326 struct mem_cgroup_per_zone
*mz
;
327 struct page_cgroup
*pc
;
329 if (mem_cgroup_disabled())
332 pc
= lookup_page_cgroup(page
);
334 /* unused page is not rotated. */
335 if (!PageCgroupUsed(pc
))
337 mz
= page_cgroup_zoneinfo(pc
);
338 list_move(&pc
->lru
, &mz
->lists
[lru
]);
341 void mem_cgroup_add_lru_list(struct page
*page
, enum lru_list lru
)
343 struct page_cgroup
*pc
;
344 struct mem_cgroup_per_zone
*mz
;
346 if (mem_cgroup_disabled())
348 pc
= lookup_page_cgroup(page
);
349 /* barrier to sync with "charge" */
351 if (!PageCgroupUsed(pc
))
354 mz
= page_cgroup_zoneinfo(pc
);
355 MEM_CGROUP_ZSTAT(mz
, lru
) += 1;
356 list_add(&pc
->lru
, &mz
->lists
[lru
]);
359 * To add swapcache into LRU. Be careful to all this function.
360 * zone->lru_lock shouldn't be held and irq must not be disabled.
362 static void mem_cgroup_lru_fixup(struct page
*page
)
364 if (!isolate_lru_page(page
))
365 putback_lru_page(page
);
368 void mem_cgroup_move_lists(struct page
*page
,
369 enum lru_list from
, enum lru_list to
)
371 if (mem_cgroup_disabled())
373 mem_cgroup_del_lru_list(page
, from
);
374 mem_cgroup_add_lru_list(page
, to
);
377 int task_in_mem_cgroup(struct task_struct
*task
, const struct mem_cgroup
*mem
)
382 ret
= task
->mm
&& mm_match_cgroup(task
->mm
, mem
);
388 * Calculate mapped_ratio under memory controller. This will be used in
389 * vmscan.c for deteremining we have to reclaim mapped pages.
391 int mem_cgroup_calc_mapped_ratio(struct mem_cgroup
*mem
)
396 * usage is recorded in bytes. But, here, we assume the number of
397 * physical pages can be represented by "long" on any arch.
399 total
= (long) (mem
->res
.usage
>> PAGE_SHIFT
) + 1L;
400 rss
= (long)mem_cgroup_read_stat(&mem
->stat
, MEM_CGROUP_STAT_RSS
);
401 return (int)((rss
* 100L) / total
);
405 * prev_priority control...this will be used in memory reclaim path.
407 int mem_cgroup_get_reclaim_priority(struct mem_cgroup
*mem
)
411 spin_lock(&mem
->reclaim_param_lock
);
412 prev_priority
= mem
->prev_priority
;
413 spin_unlock(&mem
->reclaim_param_lock
);
415 return prev_priority
;
418 void mem_cgroup_note_reclaim_priority(struct mem_cgroup
*mem
, int priority
)
420 spin_lock(&mem
->reclaim_param_lock
);
421 if (priority
< mem
->prev_priority
)
422 mem
->prev_priority
= priority
;
423 spin_unlock(&mem
->reclaim_param_lock
);
426 void mem_cgroup_record_reclaim_priority(struct mem_cgroup
*mem
, int priority
)
428 spin_lock(&mem
->reclaim_param_lock
);
429 mem
->prev_priority
= priority
;
430 spin_unlock(&mem
->reclaim_param_lock
);
433 static int calc_inactive_ratio(struct mem_cgroup
*memcg
, unsigned long *present_pages
)
435 unsigned long active
;
436 unsigned long inactive
;
438 unsigned long inactive_ratio
;
440 inactive
= mem_cgroup_get_all_zonestat(memcg
, LRU_INACTIVE_ANON
);
441 active
= mem_cgroup_get_all_zonestat(memcg
, LRU_ACTIVE_ANON
);
443 gb
= (inactive
+ active
) >> (30 - PAGE_SHIFT
);
445 inactive_ratio
= int_sqrt(10 * gb
);
450 present_pages
[0] = inactive
;
451 present_pages
[1] = active
;
454 return inactive_ratio
;
457 int mem_cgroup_inactive_anon_is_low(struct mem_cgroup
*memcg
)
459 unsigned long active
;
460 unsigned long inactive
;
461 unsigned long present_pages
[2];
462 unsigned long inactive_ratio
;
464 inactive_ratio
= calc_inactive_ratio(memcg
, present_pages
);
466 inactive
= present_pages
[0];
467 active
= present_pages
[1];
469 if (inactive
* inactive_ratio
< active
)
475 unsigned long mem_cgroup_zone_nr_pages(struct mem_cgroup
*memcg
,
479 int nid
= zone
->zone_pgdat
->node_id
;
480 int zid
= zone_idx(zone
);
481 struct mem_cgroup_per_zone
*mz
= mem_cgroup_zoneinfo(memcg
, nid
, zid
);
483 return MEM_CGROUP_ZSTAT(mz
, lru
);
486 struct zone_reclaim_stat
*mem_cgroup_get_reclaim_stat(struct mem_cgroup
*memcg
,
489 int nid
= zone
->zone_pgdat
->node_id
;
490 int zid
= zone_idx(zone
);
491 struct mem_cgroup_per_zone
*mz
= mem_cgroup_zoneinfo(memcg
, nid
, zid
);
493 return &mz
->reclaim_stat
;
496 struct zone_reclaim_stat
*
497 mem_cgroup_get_reclaim_stat_from_page(struct page
*page
)
499 struct page_cgroup
*pc
;
500 struct mem_cgroup_per_zone
*mz
;
502 if (mem_cgroup_disabled())
505 pc
= lookup_page_cgroup(page
);
506 mz
= page_cgroup_zoneinfo(pc
);
510 return &mz
->reclaim_stat
;
513 unsigned long mem_cgroup_isolate_pages(unsigned long nr_to_scan
,
514 struct list_head
*dst
,
515 unsigned long *scanned
, int order
,
516 int mode
, struct zone
*z
,
517 struct mem_cgroup
*mem_cont
,
518 int active
, int file
)
520 unsigned long nr_taken
= 0;
524 struct list_head
*src
;
525 struct page_cgroup
*pc
, *tmp
;
526 int nid
= z
->zone_pgdat
->node_id
;
527 int zid
= zone_idx(z
);
528 struct mem_cgroup_per_zone
*mz
;
529 int lru
= LRU_FILE
* !!file
+ !!active
;
532 mz
= mem_cgroup_zoneinfo(mem_cont
, nid
, zid
);
533 src
= &mz
->lists
[lru
];
536 list_for_each_entry_safe_reverse(pc
, tmp
, src
, lru
) {
537 if (scan
>= nr_to_scan
)
541 if (unlikely(!PageCgroupUsed(pc
)))
543 if (unlikely(!PageLRU(page
)))
547 if (__isolate_lru_page(page
, mode
, file
) == 0) {
548 list_move(&page
->lru
, dst
);
557 #define mem_cgroup_from_res_counter(counter, member) \
558 container_of(counter, struct mem_cgroup, member)
561 * This routine finds the DFS walk successor. This routine should be
562 * called with cgroup_mutex held
564 static struct mem_cgroup
*
565 mem_cgroup_get_next_node(struct mem_cgroup
*curr
, struct mem_cgroup
*root_mem
)
567 struct cgroup
*cgroup
, *curr_cgroup
, *root_cgroup
;
569 curr_cgroup
= curr
->css
.cgroup
;
570 root_cgroup
= root_mem
->css
.cgroup
;
572 if (!list_empty(&curr_cgroup
->children
)) {
574 * Walk down to children
576 mem_cgroup_put(curr
);
577 cgroup
= list_entry(curr_cgroup
->children
.next
,
578 struct cgroup
, sibling
);
579 curr
= mem_cgroup_from_cont(cgroup
);
580 mem_cgroup_get(curr
);
585 if (curr_cgroup
== root_cgroup
) {
586 mem_cgroup_put(curr
);
588 mem_cgroup_get(curr
);
595 if (curr_cgroup
->sibling
.next
!= &curr_cgroup
->parent
->children
) {
596 mem_cgroup_put(curr
);
597 cgroup
= list_entry(curr_cgroup
->sibling
.next
, struct cgroup
,
599 curr
= mem_cgroup_from_cont(cgroup
);
600 mem_cgroup_get(curr
);
605 * Go up to next parent and next parent's sibling if need be
607 curr_cgroup
= curr_cgroup
->parent
;
611 root_mem
->last_scanned_child
= curr
;
616 * Visit the first child (need not be the first child as per the ordering
617 * of the cgroup list, since we track last_scanned_child) of @mem and use
618 * that to reclaim free pages from.
620 static struct mem_cgroup
*
621 mem_cgroup_get_first_node(struct mem_cgroup
*root_mem
)
623 struct cgroup
*cgroup
;
624 struct mem_cgroup
*ret
;
625 bool obsolete
= (root_mem
->last_scanned_child
&&
626 root_mem
->last_scanned_child
->obsolete
);
629 * Scan all children under the mem_cgroup mem
632 if (list_empty(&root_mem
->css
.cgroup
->children
)) {
637 if (!root_mem
->last_scanned_child
|| obsolete
) {
640 mem_cgroup_put(root_mem
->last_scanned_child
);
642 cgroup
= list_first_entry(&root_mem
->css
.cgroup
->children
,
643 struct cgroup
, sibling
);
644 ret
= mem_cgroup_from_cont(cgroup
);
647 ret
= mem_cgroup_get_next_node(root_mem
->last_scanned_child
,
651 root_mem
->last_scanned_child
= ret
;
656 static bool mem_cgroup_check_under_limit(struct mem_cgroup
*mem
)
658 if (do_swap_account
) {
659 if (res_counter_check_under_limit(&mem
->res
) &&
660 res_counter_check_under_limit(&mem
->memsw
))
663 if (res_counter_check_under_limit(&mem
->res
))
668 static unsigned int get_swappiness(struct mem_cgroup
*memcg
)
670 struct cgroup
*cgrp
= memcg
->css
.cgroup
;
671 unsigned int swappiness
;
674 if (cgrp
->parent
== NULL
)
675 return vm_swappiness
;
677 spin_lock(&memcg
->reclaim_param_lock
);
678 swappiness
= memcg
->swappiness
;
679 spin_unlock(&memcg
->reclaim_param_lock
);
685 * Dance down the hierarchy if needed to reclaim memory. We remember the
686 * last child we reclaimed from, so that we don't end up penalizing
687 * one child extensively based on its position in the children list.
689 * root_mem is the original ancestor that we've been reclaim from.
691 static int mem_cgroup_hierarchical_reclaim(struct mem_cgroup
*root_mem
,
692 gfp_t gfp_mask
, bool noswap
)
694 struct mem_cgroup
*next_mem
;
698 * Reclaim unconditionally and don't check for return value.
699 * We need to reclaim in the current group and down the tree.
700 * One might think about checking for children before reclaiming,
701 * but there might be left over accounting, even after children
704 ret
= try_to_free_mem_cgroup_pages(root_mem
, gfp_mask
, noswap
,
705 get_swappiness(root_mem
));
706 if (mem_cgroup_check_under_limit(root_mem
))
708 if (!root_mem
->use_hierarchy
)
711 next_mem
= mem_cgroup_get_first_node(root_mem
);
713 while (next_mem
!= root_mem
) {
714 if (next_mem
->obsolete
) {
715 mem_cgroup_put(next_mem
);
717 next_mem
= mem_cgroup_get_first_node(root_mem
);
721 ret
= try_to_free_mem_cgroup_pages(next_mem
, gfp_mask
, noswap
,
722 get_swappiness(next_mem
));
723 if (mem_cgroup_check_under_limit(root_mem
))
726 next_mem
= mem_cgroup_get_next_node(next_mem
, root_mem
);
732 bool mem_cgroup_oom_called(struct task_struct
*task
)
735 struct mem_cgroup
*mem
;
736 struct mm_struct
*mm
;
742 mem
= mem_cgroup_from_task(rcu_dereference(mm
->owner
));
743 if (mem
&& time_before(jiffies
, mem
->last_oom_jiffies
+ HZ
/10))
749 * Unlike exported interface, "oom" parameter is added. if oom==true,
750 * oom-killer can be invoked.
752 static int __mem_cgroup_try_charge(struct mm_struct
*mm
,
753 gfp_t gfp_mask
, struct mem_cgroup
**memcg
,
756 struct mem_cgroup
*mem
, *mem_over_limit
;
757 int nr_retries
= MEM_CGROUP_RECLAIM_RETRIES
;
758 struct res_counter
*fail_res
;
760 if (unlikely(test_thread_flag(TIF_MEMDIE
))) {
761 /* Don't account this! */
767 * We always charge the cgroup the mm_struct belongs to.
768 * The mm_struct's mem_cgroup changes on task migration if the
769 * thread group leader migrates. It's possible that mm is not
770 * set, if so charge the init_mm (happens for pagecache usage).
772 if (likely(!*memcg
)) {
774 mem
= mem_cgroup_from_task(rcu_dereference(mm
->owner
));
775 if (unlikely(!mem
)) {
780 * For every charge from the cgroup, increment reference count
794 ret
= res_counter_charge(&mem
->res
, PAGE_SIZE
, &fail_res
);
796 if (!do_swap_account
)
798 ret
= res_counter_charge(&mem
->memsw
, PAGE_SIZE
,
802 /* mem+swap counter fails */
803 res_counter_uncharge(&mem
->res
, PAGE_SIZE
);
805 mem_over_limit
= mem_cgroup_from_res_counter(fail_res
,
808 /* mem counter fails */
809 mem_over_limit
= mem_cgroup_from_res_counter(fail_res
,
812 if (!(gfp_mask
& __GFP_WAIT
))
815 ret
= mem_cgroup_hierarchical_reclaim(mem_over_limit
, gfp_mask
,
819 * try_to_free_mem_cgroup_pages() might not give us a full
820 * picture of reclaim. Some pages are reclaimed and might be
821 * moved to swap cache or just unmapped from the cgroup.
822 * Check the limit again to see if the reclaim reduced the
823 * current usage of the cgroup before giving up
826 if (mem_cgroup_check_under_limit(mem_over_limit
))
831 mutex_lock(&memcg_tasklist
);
832 mem_cgroup_out_of_memory(mem_over_limit
, gfp_mask
);
833 mutex_unlock(&memcg_tasklist
);
834 mem_over_limit
->last_oom_jiffies
= jiffies
;
846 * commit a charge got by __mem_cgroup_try_charge() and makes page_cgroup to be
847 * USED state. If already USED, uncharge and return.
850 static void __mem_cgroup_commit_charge(struct mem_cgroup
*mem
,
851 struct page_cgroup
*pc
,
852 enum charge_type ctype
)
854 /* try_charge() can return NULL to *memcg, taking care of it. */
858 lock_page_cgroup(pc
);
859 if (unlikely(PageCgroupUsed(pc
))) {
860 unlock_page_cgroup(pc
);
861 res_counter_uncharge(&mem
->res
, PAGE_SIZE
);
863 res_counter_uncharge(&mem
->memsw
, PAGE_SIZE
);
867 pc
->mem_cgroup
= mem
;
869 pc
->flags
= pcg_default_flags
[ctype
];
871 mem_cgroup_charge_statistics(mem
, pc
, true);
873 unlock_page_cgroup(pc
);
877 * mem_cgroup_move_account - move account of the page
878 * @pc: page_cgroup of the page.
879 * @from: mem_cgroup which the page is moved from.
880 * @to: mem_cgroup which the page is moved to. @from != @to.
882 * The caller must confirm following.
883 * - page is not on LRU (isolate_page() is useful.)
885 * returns 0 at success,
886 * returns -EBUSY when lock is busy or "pc" is unstable.
888 * This function does "uncharge" from old cgroup but doesn't do "charge" to
889 * new cgroup. It should be done by a caller.
892 static int mem_cgroup_move_account(struct page_cgroup
*pc
,
893 struct mem_cgroup
*from
, struct mem_cgroup
*to
)
895 struct mem_cgroup_per_zone
*from_mz
, *to_mz
;
899 VM_BUG_ON(from
== to
);
900 VM_BUG_ON(PageLRU(pc
->page
));
902 nid
= page_cgroup_nid(pc
);
903 zid
= page_cgroup_zid(pc
);
904 from_mz
= mem_cgroup_zoneinfo(from
, nid
, zid
);
905 to_mz
= mem_cgroup_zoneinfo(to
, nid
, zid
);
907 if (!trylock_page_cgroup(pc
))
910 if (!PageCgroupUsed(pc
))
913 if (pc
->mem_cgroup
!= from
)
917 res_counter_uncharge(&from
->res
, PAGE_SIZE
);
918 mem_cgroup_charge_statistics(from
, pc
, false);
920 res_counter_uncharge(&from
->memsw
, PAGE_SIZE
);
922 mem_cgroup_charge_statistics(to
, pc
, true);
926 unlock_page_cgroup(pc
);
931 * move charges to its parent.
934 static int mem_cgroup_move_parent(struct page_cgroup
*pc
,
935 struct mem_cgroup
*child
,
938 struct page
*page
= pc
->page
;
939 struct cgroup
*cg
= child
->css
.cgroup
;
940 struct cgroup
*pcg
= cg
->parent
;
941 struct mem_cgroup
*parent
;
949 parent
= mem_cgroup_from_cont(pcg
);
952 ret
= __mem_cgroup_try_charge(NULL
, gfp_mask
, &parent
, false);
956 if (!get_page_unless_zero(page
))
959 ret
= isolate_lru_page(page
);
964 ret
= mem_cgroup_move_account(pc
, child
, parent
);
966 /* drop extra refcnt by try_charge() (move_account increment one) */
967 css_put(&parent
->css
);
968 putback_lru_page(page
);
973 /* uncharge if move fails */
975 res_counter_uncharge(&parent
->res
, PAGE_SIZE
);
977 res_counter_uncharge(&parent
->memsw
, PAGE_SIZE
);
983 * Charge the memory controller for page usage.
985 * 0 if the charge was successful
986 * < 0 if the cgroup is over its limit
988 static int mem_cgroup_charge_common(struct page
*page
, struct mm_struct
*mm
,
989 gfp_t gfp_mask
, enum charge_type ctype
,
990 struct mem_cgroup
*memcg
)
992 struct mem_cgroup
*mem
;
993 struct page_cgroup
*pc
;
996 pc
= lookup_page_cgroup(page
);
997 /* can happen at boot */
1003 ret
= __mem_cgroup_try_charge(mm
, gfp_mask
, &mem
, true);
1007 __mem_cgroup_commit_charge(mem
, pc
, ctype
);
1011 int mem_cgroup_newpage_charge(struct page
*page
,
1012 struct mm_struct
*mm
, gfp_t gfp_mask
)
1014 if (mem_cgroup_disabled())
1016 if (PageCompound(page
))
1019 * If already mapped, we don't have to account.
1020 * If page cache, page->mapping has address_space.
1021 * But page->mapping may have out-of-use anon_vma pointer,
1022 * detecit it by PageAnon() check. newly-mapped-anon's page->mapping
1025 if (page_mapped(page
) || (page
->mapping
&& !PageAnon(page
)))
1029 return mem_cgroup_charge_common(page
, mm
, gfp_mask
,
1030 MEM_CGROUP_CHARGE_TYPE_MAPPED
, NULL
);
1033 int mem_cgroup_cache_charge(struct page
*page
, struct mm_struct
*mm
,
1036 if (mem_cgroup_disabled())
1038 if (PageCompound(page
))
1041 * Corner case handling. This is called from add_to_page_cache()
1042 * in usual. But some FS (shmem) precharges this page before calling it
1043 * and call add_to_page_cache() with GFP_NOWAIT.
1045 * For GFP_NOWAIT case, the page may be pre-charged before calling
1046 * add_to_page_cache(). (See shmem.c) check it here and avoid to call
1047 * charge twice. (It works but has to pay a bit larger cost.)
1049 if (!(gfp_mask
& __GFP_WAIT
)) {
1050 struct page_cgroup
*pc
;
1053 pc
= lookup_page_cgroup(page
);
1056 lock_page_cgroup(pc
);
1057 if (PageCgroupUsed(pc
)) {
1058 unlock_page_cgroup(pc
);
1061 unlock_page_cgroup(pc
);
1067 if (page_is_file_cache(page
))
1068 return mem_cgroup_charge_common(page
, mm
, gfp_mask
,
1069 MEM_CGROUP_CHARGE_TYPE_CACHE
, NULL
);
1071 return mem_cgroup_charge_common(page
, mm
, gfp_mask
,
1072 MEM_CGROUP_CHARGE_TYPE_SHMEM
, NULL
);
1075 int mem_cgroup_try_charge_swapin(struct mm_struct
*mm
,
1077 gfp_t mask
, struct mem_cgroup
**ptr
)
1079 struct mem_cgroup
*mem
;
1082 if (mem_cgroup_disabled())
1085 if (!do_swap_account
)
1089 * A racing thread's fault, or swapoff, may have already updated
1090 * the pte, and even removed page from swap cache: return success
1091 * to go on to do_swap_page()'s pte_same() test, which should fail.
1093 if (!PageSwapCache(page
))
1096 ent
.val
= page_private(page
);
1098 mem
= lookup_swap_cgroup(ent
);
1099 if (!mem
|| mem
->obsolete
)
1102 return __mem_cgroup_try_charge(NULL
, mask
, ptr
, true);
1106 return __mem_cgroup_try_charge(mm
, mask
, ptr
, true);
1111 int mem_cgroup_cache_charge_swapin(struct page
*page
,
1112 struct mm_struct
*mm
, gfp_t mask
, bool locked
)
1116 if (mem_cgroup_disabled())
1123 * If not locked, the page can be dropped from SwapCache until
1126 if (PageSwapCache(page
)) {
1127 struct mem_cgroup
*mem
= NULL
;
1130 ent
.val
= page_private(page
);
1131 if (do_swap_account
) {
1132 mem
= lookup_swap_cgroup(ent
);
1133 if (mem
&& mem
->obsolete
)
1138 ret
= mem_cgroup_charge_common(page
, mm
, mask
,
1139 MEM_CGROUP_CHARGE_TYPE_SHMEM
, mem
);
1141 if (!ret
&& do_swap_account
) {
1142 /* avoid double counting */
1143 mem
= swap_cgroup_record(ent
, NULL
);
1145 res_counter_uncharge(&mem
->memsw
, PAGE_SIZE
);
1146 mem_cgroup_put(mem
);
1152 /* add this page(page_cgroup) to the LRU we want. */
1153 mem_cgroup_lru_fixup(page
);
1159 void mem_cgroup_commit_charge_swapin(struct page
*page
, struct mem_cgroup
*ptr
)
1161 struct page_cgroup
*pc
;
1163 if (mem_cgroup_disabled())
1167 pc
= lookup_page_cgroup(page
);
1168 __mem_cgroup_commit_charge(ptr
, pc
, MEM_CGROUP_CHARGE_TYPE_MAPPED
);
1170 * Now swap is on-memory. This means this page may be
1171 * counted both as mem and swap....double count.
1172 * Fix it by uncharging from memsw. This SwapCache is stable
1173 * because we're still under lock_page().
1175 if (do_swap_account
) {
1176 swp_entry_t ent
= {.val
= page_private(page
)};
1177 struct mem_cgroup
*memcg
;
1178 memcg
= swap_cgroup_record(ent
, NULL
);
1180 /* If memcg is obsolete, memcg can be != ptr */
1181 res_counter_uncharge(&memcg
->memsw
, PAGE_SIZE
);
1182 mem_cgroup_put(memcg
);
1186 /* add this page(page_cgroup) to the LRU we want. */
1187 mem_cgroup_lru_fixup(page
);
1190 void mem_cgroup_cancel_charge_swapin(struct mem_cgroup
*mem
)
1192 if (mem_cgroup_disabled())
1196 res_counter_uncharge(&mem
->res
, PAGE_SIZE
);
1197 if (do_swap_account
)
1198 res_counter_uncharge(&mem
->memsw
, PAGE_SIZE
);
1204 * uncharge if !page_mapped(page)
1206 static struct mem_cgroup
*
1207 __mem_cgroup_uncharge_common(struct page
*page
, enum charge_type ctype
)
1209 struct page_cgroup
*pc
;
1210 struct mem_cgroup
*mem
= NULL
;
1211 struct mem_cgroup_per_zone
*mz
;
1213 if (mem_cgroup_disabled())
1216 if (PageSwapCache(page
))
1220 * Check if our page_cgroup is valid
1222 pc
= lookup_page_cgroup(page
);
1223 if (unlikely(!pc
|| !PageCgroupUsed(pc
)))
1226 lock_page_cgroup(pc
);
1228 mem
= pc
->mem_cgroup
;
1230 if (!PageCgroupUsed(pc
))
1234 case MEM_CGROUP_CHARGE_TYPE_MAPPED
:
1235 if (page_mapped(page
))
1238 case MEM_CGROUP_CHARGE_TYPE_SWAPOUT
:
1239 if (!PageAnon(page
)) { /* Shared memory */
1240 if (page
->mapping
&& !page_is_file_cache(page
))
1242 } else if (page_mapped(page
)) /* Anon */
1249 res_counter_uncharge(&mem
->res
, PAGE_SIZE
);
1250 if (do_swap_account
&& (ctype
!= MEM_CGROUP_CHARGE_TYPE_SWAPOUT
))
1251 res_counter_uncharge(&mem
->memsw
, PAGE_SIZE
);
1253 mem_cgroup_charge_statistics(mem
, pc
, false);
1254 ClearPageCgroupUsed(pc
);
1256 mz
= page_cgroup_zoneinfo(pc
);
1257 unlock_page_cgroup(pc
);
1259 /* at swapout, this memcg will be accessed to record to swap */
1260 if (ctype
!= MEM_CGROUP_CHARGE_TYPE_SWAPOUT
)
1266 unlock_page_cgroup(pc
);
1270 void mem_cgroup_uncharge_page(struct page
*page
)
1273 if (page_mapped(page
))
1275 if (page
->mapping
&& !PageAnon(page
))
1277 __mem_cgroup_uncharge_common(page
, MEM_CGROUP_CHARGE_TYPE_MAPPED
);
1280 void mem_cgroup_uncharge_cache_page(struct page
*page
)
1282 VM_BUG_ON(page_mapped(page
));
1283 VM_BUG_ON(page
->mapping
);
1284 __mem_cgroup_uncharge_common(page
, MEM_CGROUP_CHARGE_TYPE_CACHE
);
1288 * called from __delete_from_swap_cache() and drop "page" account.
1289 * memcg information is recorded to swap_cgroup of "ent"
1291 void mem_cgroup_uncharge_swapcache(struct page
*page
, swp_entry_t ent
)
1293 struct mem_cgroup
*memcg
;
1295 memcg
= __mem_cgroup_uncharge_common(page
,
1296 MEM_CGROUP_CHARGE_TYPE_SWAPOUT
);
1297 /* record memcg information */
1298 if (do_swap_account
&& memcg
) {
1299 swap_cgroup_record(ent
, memcg
);
1300 mem_cgroup_get(memcg
);
1303 css_put(&memcg
->css
);
1306 #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP
1308 * called from swap_entry_free(). remove record in swap_cgroup and
1309 * uncharge "memsw" account.
1311 void mem_cgroup_uncharge_swap(swp_entry_t ent
)
1313 struct mem_cgroup
*memcg
;
1315 if (!do_swap_account
)
1318 memcg
= swap_cgroup_record(ent
, NULL
);
1320 res_counter_uncharge(&memcg
->memsw
, PAGE_SIZE
);
1321 mem_cgroup_put(memcg
);
1327 * Before starting migration, account PAGE_SIZE to mem_cgroup that the old
1330 int mem_cgroup_prepare_migration(struct page
*page
, struct mem_cgroup
**ptr
)
1332 struct page_cgroup
*pc
;
1333 struct mem_cgroup
*mem
= NULL
;
1336 if (mem_cgroup_disabled())
1339 pc
= lookup_page_cgroup(page
);
1340 lock_page_cgroup(pc
);
1341 if (PageCgroupUsed(pc
)) {
1342 mem
= pc
->mem_cgroup
;
1345 unlock_page_cgroup(pc
);
1348 ret
= __mem_cgroup_try_charge(NULL
, GFP_KERNEL
, &mem
, false);
1355 /* remove redundant charge if migration failed*/
1356 void mem_cgroup_end_migration(struct mem_cgroup
*mem
,
1357 struct page
*oldpage
, struct page
*newpage
)
1359 struct page
*target
, *unused
;
1360 struct page_cgroup
*pc
;
1361 enum charge_type ctype
;
1366 /* at migration success, oldpage->mapping is NULL. */
1367 if (oldpage
->mapping
) {
1375 if (PageAnon(target
))
1376 ctype
= MEM_CGROUP_CHARGE_TYPE_MAPPED
;
1377 else if (page_is_file_cache(target
))
1378 ctype
= MEM_CGROUP_CHARGE_TYPE_CACHE
;
1380 ctype
= MEM_CGROUP_CHARGE_TYPE_SHMEM
;
1382 /* unused page is not on radix-tree now. */
1384 __mem_cgroup_uncharge_common(unused
, ctype
);
1386 pc
= lookup_page_cgroup(target
);
1388 * __mem_cgroup_commit_charge() check PCG_USED bit of page_cgroup.
1389 * So, double-counting is effectively avoided.
1391 __mem_cgroup_commit_charge(mem
, pc
, ctype
);
1394 * Both of oldpage and newpage are still under lock_page().
1395 * Then, we don't have to care about race in radix-tree.
1396 * But we have to be careful that this page is unmapped or not.
1398 * There is a case for !page_mapped(). At the start of
1399 * migration, oldpage was mapped. But now, it's zapped.
1400 * But we know *target* page is not freed/reused under us.
1401 * mem_cgroup_uncharge_page() does all necessary checks.
1403 if (ctype
== MEM_CGROUP_CHARGE_TYPE_MAPPED
)
1404 mem_cgroup_uncharge_page(target
);
1408 * A call to try to shrink memory usage under specified resource controller.
1409 * This is typically used for page reclaiming for shmem for reducing side
1410 * effect of page allocation from shmem, which is used by some mem_cgroup.
1412 int mem_cgroup_shrink_usage(struct mm_struct
*mm
, gfp_t gfp_mask
)
1414 struct mem_cgroup
*mem
;
1416 int retry
= MEM_CGROUP_RECLAIM_RETRIES
;
1418 if (mem_cgroup_disabled())
1424 mem
= mem_cgroup_from_task(rcu_dereference(mm
->owner
));
1425 if (unlikely(!mem
)) {
1433 progress
= try_to_free_mem_cgroup_pages(mem
, gfp_mask
, true,
1434 get_swappiness(mem
));
1435 progress
+= mem_cgroup_check_under_limit(mem
);
1436 } while (!progress
&& --retry
);
1444 static DEFINE_MUTEX(set_limit_mutex
);
1446 static int mem_cgroup_resize_limit(struct mem_cgroup
*memcg
,
1447 unsigned long long val
)
1450 int retry_count
= MEM_CGROUP_RECLAIM_RETRIES
;
1455 while (retry_count
) {
1456 if (signal_pending(current
)) {
1461 * Rather than hide all in some function, I do this in
1462 * open coded manner. You see what this really does.
1463 * We have to guarantee mem->res.limit < mem->memsw.limit.
1465 mutex_lock(&set_limit_mutex
);
1466 memswlimit
= res_counter_read_u64(&memcg
->memsw
, RES_LIMIT
);
1467 if (memswlimit
< val
) {
1469 mutex_unlock(&set_limit_mutex
);
1472 ret
= res_counter_set_limit(&memcg
->res
, val
);
1473 mutex_unlock(&set_limit_mutex
);
1478 progress
= try_to_free_mem_cgroup_pages(memcg
,
1481 get_swappiness(memcg
));
1482 if (!progress
) retry_count
--;
1488 int mem_cgroup_resize_memsw_limit(struct mem_cgroup
*memcg
,
1489 unsigned long long val
)
1491 int retry_count
= MEM_CGROUP_RECLAIM_RETRIES
;
1492 u64 memlimit
, oldusage
, curusage
;
1495 if (!do_swap_account
)
1498 while (retry_count
) {
1499 if (signal_pending(current
)) {
1504 * Rather than hide all in some function, I do this in
1505 * open coded manner. You see what this really does.
1506 * We have to guarantee mem->res.limit < mem->memsw.limit.
1508 mutex_lock(&set_limit_mutex
);
1509 memlimit
= res_counter_read_u64(&memcg
->res
, RES_LIMIT
);
1510 if (memlimit
> val
) {
1512 mutex_unlock(&set_limit_mutex
);
1515 ret
= res_counter_set_limit(&memcg
->memsw
, val
);
1516 mutex_unlock(&set_limit_mutex
);
1521 oldusage
= res_counter_read_u64(&memcg
->memsw
, RES_USAGE
);
1522 try_to_free_mem_cgroup_pages(memcg
, GFP_KERNEL
, true,
1523 get_swappiness(memcg
));
1524 curusage
= res_counter_read_u64(&memcg
->memsw
, RES_USAGE
);
1525 if (curusage
>= oldusage
)
1532 * This routine traverse page_cgroup in given list and drop them all.
1533 * *And* this routine doesn't reclaim page itself, just removes page_cgroup.
1535 static int mem_cgroup_force_empty_list(struct mem_cgroup
*mem
,
1536 int node
, int zid
, enum lru_list lru
)
1539 struct mem_cgroup_per_zone
*mz
;
1540 struct page_cgroup
*pc
, *busy
;
1541 unsigned long flags
, loop
;
1542 struct list_head
*list
;
1545 zone
= &NODE_DATA(node
)->node_zones
[zid
];
1546 mz
= mem_cgroup_zoneinfo(mem
, node
, zid
);
1547 list
= &mz
->lists
[lru
];
1549 loop
= MEM_CGROUP_ZSTAT(mz
, lru
);
1550 /* give some margin against EBUSY etc...*/
1555 spin_lock_irqsave(&zone
->lru_lock
, flags
);
1556 if (list_empty(list
)) {
1557 spin_unlock_irqrestore(&zone
->lru_lock
, flags
);
1560 pc
= list_entry(list
->prev
, struct page_cgroup
, lru
);
1562 list_move(&pc
->lru
, list
);
1564 spin_unlock_irqrestore(&zone
->lru_lock
, flags
);
1567 spin_unlock_irqrestore(&zone
->lru_lock
, flags
);
1569 ret
= mem_cgroup_move_parent(pc
, mem
, GFP_KERNEL
);
1573 if (ret
== -EBUSY
|| ret
== -EINVAL
) {
1574 /* found lock contention or "pc" is obsolete. */
1581 if (!ret
&& !list_empty(list
))
1587 * make mem_cgroup's charge to be 0 if there is no task.
1588 * This enables deleting this mem_cgroup.
1590 static int mem_cgroup_force_empty(struct mem_cgroup
*mem
, bool free_all
)
1593 int node
, zid
, shrink
;
1594 int nr_retries
= MEM_CGROUP_RECLAIM_RETRIES
;
1595 struct cgroup
*cgrp
= mem
->css
.cgroup
;
1600 /* should free all ? */
1604 while (mem
->res
.usage
> 0) {
1606 if (cgroup_task_count(cgrp
) || !list_empty(&cgrp
->children
))
1609 if (signal_pending(current
))
1611 /* This is for making all *used* pages to be on LRU. */
1612 lru_add_drain_all();
1614 for_each_node_state(node
, N_POSSIBLE
) {
1615 for (zid
= 0; !ret
&& zid
< MAX_NR_ZONES
; zid
++) {
1618 ret
= mem_cgroup_force_empty_list(mem
,
1627 /* it seems parent cgroup doesn't have enough mem */
1638 /* returns EBUSY if there is a task or if we come here twice. */
1639 if (cgroup_task_count(cgrp
) || !list_empty(&cgrp
->children
) || shrink
) {
1643 /* we call try-to-free pages for make this cgroup empty */
1644 lru_add_drain_all();
1645 /* try to free all pages in this cgroup */
1647 while (nr_retries
&& mem
->res
.usage
> 0) {
1650 if (signal_pending(current
)) {
1654 progress
= try_to_free_mem_cgroup_pages(mem
, GFP_KERNEL
,
1655 false, get_swappiness(mem
));
1658 /* maybe some writeback is necessary */
1659 congestion_wait(WRITE
, HZ
/10);
1664 /* try move_account...there may be some *locked* pages. */
1671 int mem_cgroup_force_empty_write(struct cgroup
*cont
, unsigned int event
)
1673 return mem_cgroup_force_empty(mem_cgroup_from_cont(cont
), true);
1677 static u64
mem_cgroup_hierarchy_read(struct cgroup
*cont
, struct cftype
*cft
)
1679 return mem_cgroup_from_cont(cont
)->use_hierarchy
;
1682 static int mem_cgroup_hierarchy_write(struct cgroup
*cont
, struct cftype
*cft
,
1686 struct mem_cgroup
*mem
= mem_cgroup_from_cont(cont
);
1687 struct cgroup
*parent
= cont
->parent
;
1688 struct mem_cgroup
*parent_mem
= NULL
;
1691 parent_mem
= mem_cgroup_from_cont(parent
);
1695 * If parent's use_hiearchy is set, we can't make any modifications
1696 * in the child subtrees. If it is unset, then the change can
1697 * occur, provided the current cgroup has no children.
1699 * For the root cgroup, parent_mem is NULL, we allow value to be
1700 * set if there are no children.
1702 if ((!parent_mem
|| !parent_mem
->use_hierarchy
) &&
1703 (val
== 1 || val
== 0)) {
1704 if (list_empty(&cont
->children
))
1705 mem
->use_hierarchy
= val
;
1715 static u64
mem_cgroup_read(struct cgroup
*cont
, struct cftype
*cft
)
1717 struct mem_cgroup
*mem
= mem_cgroup_from_cont(cont
);
1721 type
= MEMFILE_TYPE(cft
->private);
1722 name
= MEMFILE_ATTR(cft
->private);
1725 val
= res_counter_read_u64(&mem
->res
, name
);
1728 if (do_swap_account
)
1729 val
= res_counter_read_u64(&mem
->memsw
, name
);
1738 * The user of this function is...
1741 static int mem_cgroup_write(struct cgroup
*cont
, struct cftype
*cft
,
1744 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cont
);
1746 unsigned long long val
;
1749 type
= MEMFILE_TYPE(cft
->private);
1750 name
= MEMFILE_ATTR(cft
->private);
1753 /* This function does all necessary parse...reuse it */
1754 ret
= res_counter_memparse_write_strategy(buffer
, &val
);
1758 ret
= mem_cgroup_resize_limit(memcg
, val
);
1760 ret
= mem_cgroup_resize_memsw_limit(memcg
, val
);
1763 ret
= -EINVAL
; /* should be BUG() ? */
1769 static void memcg_get_hierarchical_limit(struct mem_cgroup
*memcg
,
1770 unsigned long long *mem_limit
, unsigned long long *memsw_limit
)
1772 struct cgroup
*cgroup
;
1773 unsigned long long min_limit
, min_memsw_limit
, tmp
;
1775 min_limit
= res_counter_read_u64(&memcg
->res
, RES_LIMIT
);
1776 min_memsw_limit
= res_counter_read_u64(&memcg
->memsw
, RES_LIMIT
);
1777 cgroup
= memcg
->css
.cgroup
;
1778 if (!memcg
->use_hierarchy
)
1781 while (cgroup
->parent
) {
1782 cgroup
= cgroup
->parent
;
1783 memcg
= mem_cgroup_from_cont(cgroup
);
1784 if (!memcg
->use_hierarchy
)
1786 tmp
= res_counter_read_u64(&memcg
->res
, RES_LIMIT
);
1787 min_limit
= min(min_limit
, tmp
);
1788 tmp
= res_counter_read_u64(&memcg
->memsw
, RES_LIMIT
);
1789 min_memsw_limit
= min(min_memsw_limit
, tmp
);
1792 *mem_limit
= min_limit
;
1793 *memsw_limit
= min_memsw_limit
;
1797 static int mem_cgroup_reset(struct cgroup
*cont
, unsigned int event
)
1799 struct mem_cgroup
*mem
;
1802 mem
= mem_cgroup_from_cont(cont
);
1803 type
= MEMFILE_TYPE(event
);
1804 name
= MEMFILE_ATTR(event
);
1808 res_counter_reset_max(&mem
->res
);
1810 res_counter_reset_max(&mem
->memsw
);
1814 res_counter_reset_failcnt(&mem
->res
);
1816 res_counter_reset_failcnt(&mem
->memsw
);
1822 static const struct mem_cgroup_stat_desc
{
1825 } mem_cgroup_stat_desc
[] = {
1826 [MEM_CGROUP_STAT_CACHE
] = { "cache", PAGE_SIZE
, },
1827 [MEM_CGROUP_STAT_RSS
] = { "rss", PAGE_SIZE
, },
1828 [MEM_CGROUP_STAT_PGPGIN_COUNT
] = {"pgpgin", 1, },
1829 [MEM_CGROUP_STAT_PGPGOUT_COUNT
] = {"pgpgout", 1, },
1832 static int mem_control_stat_show(struct cgroup
*cont
, struct cftype
*cft
,
1833 struct cgroup_map_cb
*cb
)
1835 struct mem_cgroup
*mem_cont
= mem_cgroup_from_cont(cont
);
1836 struct mem_cgroup_stat
*stat
= &mem_cont
->stat
;
1839 for (i
= 0; i
< ARRAY_SIZE(stat
->cpustat
[0].count
); i
++) {
1842 val
= mem_cgroup_read_stat(stat
, i
);
1843 val
*= mem_cgroup_stat_desc
[i
].unit
;
1844 cb
->fill(cb
, mem_cgroup_stat_desc
[i
].msg
, val
);
1846 /* showing # of active pages */
1848 unsigned long active_anon
, inactive_anon
;
1849 unsigned long active_file
, inactive_file
;
1850 unsigned long unevictable
;
1852 inactive_anon
= mem_cgroup_get_all_zonestat(mem_cont
,
1854 active_anon
= mem_cgroup_get_all_zonestat(mem_cont
,
1856 inactive_file
= mem_cgroup_get_all_zonestat(mem_cont
,
1858 active_file
= mem_cgroup_get_all_zonestat(mem_cont
,
1860 unevictable
= mem_cgroup_get_all_zonestat(mem_cont
,
1863 cb
->fill(cb
, "active_anon", (active_anon
) * PAGE_SIZE
);
1864 cb
->fill(cb
, "inactive_anon", (inactive_anon
) * PAGE_SIZE
);
1865 cb
->fill(cb
, "active_file", (active_file
) * PAGE_SIZE
);
1866 cb
->fill(cb
, "inactive_file", (inactive_file
) * PAGE_SIZE
);
1867 cb
->fill(cb
, "unevictable", unevictable
* PAGE_SIZE
);
1871 unsigned long long limit
, memsw_limit
;
1872 memcg_get_hierarchical_limit(mem_cont
, &limit
, &memsw_limit
);
1873 cb
->fill(cb
, "hierarchical_memory_limit", limit
);
1874 if (do_swap_account
)
1875 cb
->fill(cb
, "hierarchical_memsw_limit", memsw_limit
);
1878 #ifdef CONFIG_DEBUG_VM
1879 cb
->fill(cb
, "inactive_ratio", calc_inactive_ratio(mem_cont
, NULL
));
1883 struct mem_cgroup_per_zone
*mz
;
1884 unsigned long recent_rotated
[2] = {0, 0};
1885 unsigned long recent_scanned
[2] = {0, 0};
1887 for_each_online_node(nid
)
1888 for (zid
= 0; zid
< MAX_NR_ZONES
; zid
++) {
1889 mz
= mem_cgroup_zoneinfo(mem_cont
, nid
, zid
);
1891 recent_rotated
[0] +=
1892 mz
->reclaim_stat
.recent_rotated
[0];
1893 recent_rotated
[1] +=
1894 mz
->reclaim_stat
.recent_rotated
[1];
1895 recent_scanned
[0] +=
1896 mz
->reclaim_stat
.recent_scanned
[0];
1897 recent_scanned
[1] +=
1898 mz
->reclaim_stat
.recent_scanned
[1];
1900 cb
->fill(cb
, "recent_rotated_anon", recent_rotated
[0]);
1901 cb
->fill(cb
, "recent_rotated_file", recent_rotated
[1]);
1902 cb
->fill(cb
, "recent_scanned_anon", recent_scanned
[0]);
1903 cb
->fill(cb
, "recent_scanned_file", recent_scanned
[1]);
1910 static u64
mem_cgroup_swappiness_read(struct cgroup
*cgrp
, struct cftype
*cft
)
1912 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cgrp
);
1914 return get_swappiness(memcg
);
1917 static int mem_cgroup_swappiness_write(struct cgroup
*cgrp
, struct cftype
*cft
,
1920 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cgrp
);
1921 struct mem_cgroup
*parent
;
1925 if (cgrp
->parent
== NULL
)
1928 parent
= mem_cgroup_from_cont(cgrp
->parent
);
1929 /* If under hierarchy, only empty-root can set this value */
1930 if ((parent
->use_hierarchy
) ||
1931 (memcg
->use_hierarchy
&& !list_empty(&cgrp
->children
)))
1934 spin_lock(&memcg
->reclaim_param_lock
);
1935 memcg
->swappiness
= val
;
1936 spin_unlock(&memcg
->reclaim_param_lock
);
1942 static struct cftype mem_cgroup_files
[] = {
1944 .name
= "usage_in_bytes",
1945 .private = MEMFILE_PRIVATE(_MEM
, RES_USAGE
),
1946 .read_u64
= mem_cgroup_read
,
1949 .name
= "max_usage_in_bytes",
1950 .private = MEMFILE_PRIVATE(_MEM
, RES_MAX_USAGE
),
1951 .trigger
= mem_cgroup_reset
,
1952 .read_u64
= mem_cgroup_read
,
1955 .name
= "limit_in_bytes",
1956 .private = MEMFILE_PRIVATE(_MEM
, RES_LIMIT
),
1957 .write_string
= mem_cgroup_write
,
1958 .read_u64
= mem_cgroup_read
,
1962 .private = MEMFILE_PRIVATE(_MEM
, RES_FAILCNT
),
1963 .trigger
= mem_cgroup_reset
,
1964 .read_u64
= mem_cgroup_read
,
1968 .read_map
= mem_control_stat_show
,
1971 .name
= "force_empty",
1972 .trigger
= mem_cgroup_force_empty_write
,
1975 .name
= "use_hierarchy",
1976 .write_u64
= mem_cgroup_hierarchy_write
,
1977 .read_u64
= mem_cgroup_hierarchy_read
,
1980 .name
= "swappiness",
1981 .read_u64
= mem_cgroup_swappiness_read
,
1982 .write_u64
= mem_cgroup_swappiness_write
,
1986 #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP
1987 static struct cftype memsw_cgroup_files
[] = {
1989 .name
= "memsw.usage_in_bytes",
1990 .private = MEMFILE_PRIVATE(_MEMSWAP
, RES_USAGE
),
1991 .read_u64
= mem_cgroup_read
,
1994 .name
= "memsw.max_usage_in_bytes",
1995 .private = MEMFILE_PRIVATE(_MEMSWAP
, RES_MAX_USAGE
),
1996 .trigger
= mem_cgroup_reset
,
1997 .read_u64
= mem_cgroup_read
,
2000 .name
= "memsw.limit_in_bytes",
2001 .private = MEMFILE_PRIVATE(_MEMSWAP
, RES_LIMIT
),
2002 .write_string
= mem_cgroup_write
,
2003 .read_u64
= mem_cgroup_read
,
2006 .name
= "memsw.failcnt",
2007 .private = MEMFILE_PRIVATE(_MEMSWAP
, RES_FAILCNT
),
2008 .trigger
= mem_cgroup_reset
,
2009 .read_u64
= mem_cgroup_read
,
2013 static int register_memsw_files(struct cgroup
*cont
, struct cgroup_subsys
*ss
)
2015 if (!do_swap_account
)
2017 return cgroup_add_files(cont
, ss
, memsw_cgroup_files
,
2018 ARRAY_SIZE(memsw_cgroup_files
));
2021 static int register_memsw_files(struct cgroup
*cont
, struct cgroup_subsys
*ss
)
2027 static int alloc_mem_cgroup_per_zone_info(struct mem_cgroup
*mem
, int node
)
2029 struct mem_cgroup_per_node
*pn
;
2030 struct mem_cgroup_per_zone
*mz
;
2032 int zone
, tmp
= node
;
2034 * This routine is called against possible nodes.
2035 * But it's BUG to call kmalloc() against offline node.
2037 * TODO: this routine can waste much memory for nodes which will
2038 * never be onlined. It's better to use memory hotplug callback
2041 if (!node_state(node
, N_NORMAL_MEMORY
))
2043 pn
= kmalloc_node(sizeof(*pn
), GFP_KERNEL
, tmp
);
2047 mem
->info
.nodeinfo
[node
] = pn
;
2048 memset(pn
, 0, sizeof(*pn
));
2050 for (zone
= 0; zone
< MAX_NR_ZONES
; zone
++) {
2051 mz
= &pn
->zoneinfo
[zone
];
2053 INIT_LIST_HEAD(&mz
->lists
[l
]);
2058 static void free_mem_cgroup_per_zone_info(struct mem_cgroup
*mem
, int node
)
2060 kfree(mem
->info
.nodeinfo
[node
]);
2063 static int mem_cgroup_size(void)
2065 int cpustat_size
= nr_cpu_ids
* sizeof(struct mem_cgroup_stat_cpu
);
2066 return sizeof(struct mem_cgroup
) + cpustat_size
;
2069 static struct mem_cgroup
*mem_cgroup_alloc(void)
2071 struct mem_cgroup
*mem
;
2072 int size
= mem_cgroup_size();
2074 if (size
< PAGE_SIZE
)
2075 mem
= kmalloc(size
, GFP_KERNEL
);
2077 mem
= vmalloc(size
);
2080 memset(mem
, 0, size
);
2085 * At destroying mem_cgroup, references from swap_cgroup can remain.
2086 * (scanning all at force_empty is too costly...)
2088 * Instead of clearing all references at force_empty, we remember
2089 * the number of reference from swap_cgroup and free mem_cgroup when
2090 * it goes down to 0.
2092 * When mem_cgroup is destroyed, mem->obsolete will be set to 0 and
2093 * entry which points to this memcg will be ignore at swapin.
2095 * Removal of cgroup itself succeeds regardless of refs from swap.
2098 static void mem_cgroup_free(struct mem_cgroup
*mem
)
2102 if (atomic_read(&mem
->refcnt
) > 0)
2106 for_each_node_state(node
, N_POSSIBLE
)
2107 free_mem_cgroup_per_zone_info(mem
, node
);
2109 if (mem_cgroup_size() < PAGE_SIZE
)
2115 static void mem_cgroup_get(struct mem_cgroup
*mem
)
2117 atomic_inc(&mem
->refcnt
);
2120 static void mem_cgroup_put(struct mem_cgroup
*mem
)
2122 if (atomic_dec_and_test(&mem
->refcnt
)) {
2125 mem_cgroup_free(mem
);
2130 #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP
2131 static void __init
enable_swap_cgroup(void)
2133 if (!mem_cgroup_disabled() && really_do_swap_account
)
2134 do_swap_account
= 1;
2137 static void __init
enable_swap_cgroup(void)
2142 static struct cgroup_subsys_state
*
2143 mem_cgroup_create(struct cgroup_subsys
*ss
, struct cgroup
*cont
)
2145 struct mem_cgroup
*mem
, *parent
;
2148 mem
= mem_cgroup_alloc();
2150 return ERR_PTR(-ENOMEM
);
2152 for_each_node_state(node
, N_POSSIBLE
)
2153 if (alloc_mem_cgroup_per_zone_info(mem
, node
))
2156 if (cont
->parent
== NULL
) {
2157 enable_swap_cgroup();
2160 parent
= mem_cgroup_from_cont(cont
->parent
);
2161 mem
->use_hierarchy
= parent
->use_hierarchy
;
2164 if (parent
&& parent
->use_hierarchy
) {
2165 res_counter_init(&mem
->res
, &parent
->res
);
2166 res_counter_init(&mem
->memsw
, &parent
->memsw
);
2168 res_counter_init(&mem
->res
, NULL
);
2169 res_counter_init(&mem
->memsw
, NULL
);
2171 mem
->last_scanned_child
= NULL
;
2172 spin_lock_init(&mem
->reclaim_param_lock
);
2175 mem
->swappiness
= get_swappiness(parent
);
2179 for_each_node_state(node
, N_POSSIBLE
)
2180 free_mem_cgroup_per_zone_info(mem
, node
);
2181 mem_cgroup_free(mem
);
2182 return ERR_PTR(-ENOMEM
);
2185 static void mem_cgroup_pre_destroy(struct cgroup_subsys
*ss
,
2186 struct cgroup
*cont
)
2188 struct mem_cgroup
*mem
= mem_cgroup_from_cont(cont
);
2190 mem_cgroup_force_empty(mem
, false);
2193 static void mem_cgroup_destroy(struct cgroup_subsys
*ss
,
2194 struct cgroup
*cont
)
2196 mem_cgroup_free(mem_cgroup_from_cont(cont
));
2199 static int mem_cgroup_populate(struct cgroup_subsys
*ss
,
2200 struct cgroup
*cont
)
2204 ret
= cgroup_add_files(cont
, ss
, mem_cgroup_files
,
2205 ARRAY_SIZE(mem_cgroup_files
));
2208 ret
= register_memsw_files(cont
, ss
);
2212 static void mem_cgroup_move_task(struct cgroup_subsys
*ss
,
2213 struct cgroup
*cont
,
2214 struct cgroup
*old_cont
,
2215 struct task_struct
*p
)
2217 mutex_lock(&memcg_tasklist
);
2219 * FIXME: It's better to move charges of this process from old
2220 * memcg to new memcg. But it's just on TODO-List now.
2222 mutex_unlock(&memcg_tasklist
);
2225 struct cgroup_subsys mem_cgroup_subsys
= {
2227 .subsys_id
= mem_cgroup_subsys_id
,
2228 .create
= mem_cgroup_create
,
2229 .pre_destroy
= mem_cgroup_pre_destroy
,
2230 .destroy
= mem_cgroup_destroy
,
2231 .populate
= mem_cgroup_populate
,
2232 .attach
= mem_cgroup_move_task
,
2236 #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP
2238 static int __init
disable_swap_account(char *s
)
2240 really_do_swap_account
= 0;
2243 __setup("noswapaccount", disable_swap_account
);