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/smp.h>
25 #include <linux/page-flags.h>
26 #include <linux/backing-dev.h>
27 #include <linux/bit_spinlock.h>
28 #include <linux/rcupdate.h>
29 #include <linux/slab.h>
30 #include <linux/swap.h>
31 #include <linux/spinlock.h>
33 #include <linux/seq_file.h>
34 #include <linux/vmalloc.h>
35 #include <linux/mm_inline.h>
36 #include <linux/page_cgroup.h>
38 #include <asm/uaccess.h>
40 struct cgroup_subsys mem_cgroup_subsys __read_mostly
;
41 #define MEM_CGROUP_RECLAIM_RETRIES 5
44 * Statistics for memory cgroup.
46 enum mem_cgroup_stat_index
{
48 * For MEM_CONTAINER_TYPE_ALL, usage = pagecache + rss.
50 MEM_CGROUP_STAT_CACHE
, /* # of pages charged as cache */
51 MEM_CGROUP_STAT_RSS
, /* # of pages charged as rss */
52 MEM_CGROUP_STAT_PGPGIN_COUNT
, /* # of pages paged in */
53 MEM_CGROUP_STAT_PGPGOUT_COUNT
, /* # of pages paged out */
55 MEM_CGROUP_STAT_NSTATS
,
58 struct mem_cgroup_stat_cpu
{
59 s64 count
[MEM_CGROUP_STAT_NSTATS
];
60 } ____cacheline_aligned_in_smp
;
62 struct mem_cgroup_stat
{
63 struct mem_cgroup_stat_cpu cpustat
[NR_CPUS
];
67 * For accounting under irq disable, no need for increment preempt count.
69 static inline void __mem_cgroup_stat_add_safe(struct mem_cgroup_stat_cpu
*stat
,
70 enum mem_cgroup_stat_index idx
, int val
)
72 stat
->count
[idx
] += val
;
75 static s64
mem_cgroup_read_stat(struct mem_cgroup_stat
*stat
,
76 enum mem_cgroup_stat_index idx
)
80 for_each_possible_cpu(cpu
)
81 ret
+= stat
->cpustat
[cpu
].count
[idx
];
86 * per-zone information in memory controller.
88 struct mem_cgroup_per_zone
{
90 * spin_lock to protect the per cgroup LRU
93 struct list_head lists
[NR_LRU_LISTS
];
94 unsigned long count
[NR_LRU_LISTS
];
96 /* Macro for accessing counter */
97 #define MEM_CGROUP_ZSTAT(mz, idx) ((mz)->count[(idx)])
99 struct mem_cgroup_per_node
{
100 struct mem_cgroup_per_zone zoneinfo
[MAX_NR_ZONES
];
103 struct mem_cgroup_lru_info
{
104 struct mem_cgroup_per_node
*nodeinfo
[MAX_NUMNODES
];
108 * The memory controller data structure. The memory controller controls both
109 * page cache and RSS per cgroup. We would eventually like to provide
110 * statistics based on the statistics developed by Rik Van Riel for clock-pro,
111 * to help the administrator determine what knobs to tune.
113 * TODO: Add a water mark for the memory controller. Reclaim will begin when
114 * we hit the water mark. May be even add a low water mark, such that
115 * no reclaim occurs from a cgroup at it's low water mark, this is
116 * a feature that will be implemented much later in the future.
119 struct cgroup_subsys_state css
;
121 * the counter to account for memory usage
123 struct res_counter res
;
125 * Per cgroup active and inactive list, similar to the
126 * per zone LRU lists.
128 struct mem_cgroup_lru_info info
;
130 int prev_priority
; /* for recording reclaim priority */
134 struct mem_cgroup_stat stat
;
136 static struct mem_cgroup init_mem_cgroup
;
139 MEM_CGROUP_CHARGE_TYPE_CACHE
= 0,
140 MEM_CGROUP_CHARGE_TYPE_MAPPED
,
141 MEM_CGROUP_CHARGE_TYPE_SHMEM
, /* used by page migration of shmem */
142 MEM_CGROUP_CHARGE_TYPE_FORCE
, /* used by force_empty */
146 /* only for here (for easy reading.) */
147 #define PCGF_CACHE (1UL << PCG_CACHE)
148 #define PCGF_USED (1UL << PCG_USED)
149 #define PCGF_ACTIVE (1UL << PCG_ACTIVE)
150 #define PCGF_LOCK (1UL << PCG_LOCK)
151 #define PCGF_FILE (1UL << PCG_FILE)
152 static const unsigned long
153 pcg_default_flags
[NR_CHARGE_TYPE
] = {
154 PCGF_CACHE
| PCGF_FILE
| PCGF_USED
| PCGF_LOCK
, /* File Cache */
155 PCGF_ACTIVE
| PCGF_USED
| PCGF_LOCK
, /* Anon */
156 PCGF_ACTIVE
| PCGF_CACHE
| PCGF_USED
| PCGF_LOCK
, /* Shmem */
161 * Always modified under lru lock. Then, not necessary to preempt_disable()
163 static void mem_cgroup_charge_statistics(struct mem_cgroup
*mem
,
164 struct page_cgroup
*pc
,
167 int val
= (charge
)? 1 : -1;
168 struct mem_cgroup_stat
*stat
= &mem
->stat
;
169 struct mem_cgroup_stat_cpu
*cpustat
;
171 VM_BUG_ON(!irqs_disabled());
173 cpustat
= &stat
->cpustat
[smp_processor_id()];
174 if (PageCgroupCache(pc
))
175 __mem_cgroup_stat_add_safe(cpustat
, MEM_CGROUP_STAT_CACHE
, val
);
177 __mem_cgroup_stat_add_safe(cpustat
, MEM_CGROUP_STAT_RSS
, val
);
180 __mem_cgroup_stat_add_safe(cpustat
,
181 MEM_CGROUP_STAT_PGPGIN_COUNT
, 1);
183 __mem_cgroup_stat_add_safe(cpustat
,
184 MEM_CGROUP_STAT_PGPGOUT_COUNT
, 1);
187 static struct mem_cgroup_per_zone
*
188 mem_cgroup_zoneinfo(struct mem_cgroup
*mem
, int nid
, int zid
)
190 return &mem
->info
.nodeinfo
[nid
]->zoneinfo
[zid
];
193 static struct mem_cgroup_per_zone
*
194 page_cgroup_zoneinfo(struct page_cgroup
*pc
)
196 struct mem_cgroup
*mem
= pc
->mem_cgroup
;
197 int nid
= page_cgroup_nid(pc
);
198 int zid
= page_cgroup_zid(pc
);
200 return mem_cgroup_zoneinfo(mem
, nid
, zid
);
203 static unsigned long mem_cgroup_get_all_zonestat(struct mem_cgroup
*mem
,
207 struct mem_cgroup_per_zone
*mz
;
210 for_each_online_node(nid
)
211 for (zid
= 0; zid
< MAX_NR_ZONES
; zid
++) {
212 mz
= mem_cgroup_zoneinfo(mem
, nid
, zid
);
213 total
+= MEM_CGROUP_ZSTAT(mz
, idx
);
218 static struct mem_cgroup
*mem_cgroup_from_cont(struct cgroup
*cont
)
220 return container_of(cgroup_subsys_state(cont
,
221 mem_cgroup_subsys_id
), struct mem_cgroup
,
225 struct mem_cgroup
*mem_cgroup_from_task(struct task_struct
*p
)
228 * mm_update_next_owner() may clear mm->owner to NULL
229 * if it races with swapoff, page migration, etc.
230 * So this can be called with p == NULL.
235 return container_of(task_subsys_state(p
, mem_cgroup_subsys_id
),
236 struct mem_cgroup
, css
);
239 static void __mem_cgroup_remove_list(struct mem_cgroup_per_zone
*mz
,
240 struct page_cgroup
*pc
)
244 if (PageCgroupUnevictable(pc
))
245 lru
= LRU_UNEVICTABLE
;
247 if (PageCgroupActive(pc
))
249 if (PageCgroupFile(pc
))
253 MEM_CGROUP_ZSTAT(mz
, lru
) -= 1;
255 mem_cgroup_charge_statistics(pc
->mem_cgroup
, pc
, false);
259 static void __mem_cgroup_add_list(struct mem_cgroup_per_zone
*mz
,
260 struct page_cgroup
*pc
)
264 if (PageCgroupUnevictable(pc
))
265 lru
= LRU_UNEVICTABLE
;
267 if (PageCgroupActive(pc
))
269 if (PageCgroupFile(pc
))
273 MEM_CGROUP_ZSTAT(mz
, lru
) += 1;
274 list_add(&pc
->lru
, &mz
->lists
[lru
]);
276 mem_cgroup_charge_statistics(pc
->mem_cgroup
, pc
, true);
279 static void __mem_cgroup_move_lists(struct page_cgroup
*pc
, enum lru_list lru
)
281 struct mem_cgroup_per_zone
*mz
= page_cgroup_zoneinfo(pc
);
282 int active
= PageCgroupActive(pc
);
283 int file
= PageCgroupFile(pc
);
284 int unevictable
= PageCgroupUnevictable(pc
);
285 enum lru_list from
= unevictable
? LRU_UNEVICTABLE
:
286 (LRU_FILE
* !!file
+ !!active
);
291 MEM_CGROUP_ZSTAT(mz
, from
) -= 1;
293 * However this is done under mz->lru_lock, another flags, which
294 * are not related to LRU, will be modified from out-of-lock.
295 * We have to use atomic set/clear flags.
297 if (is_unevictable_lru(lru
)) {
298 ClearPageCgroupActive(pc
);
299 SetPageCgroupUnevictable(pc
);
301 if (is_active_lru(lru
))
302 SetPageCgroupActive(pc
);
304 ClearPageCgroupActive(pc
);
305 ClearPageCgroupUnevictable(pc
);
308 MEM_CGROUP_ZSTAT(mz
, lru
) += 1;
309 list_move(&pc
->lru
, &mz
->lists
[lru
]);
312 int task_in_mem_cgroup(struct task_struct
*task
, const struct mem_cgroup
*mem
)
317 ret
= task
->mm
&& mm_match_cgroup(task
->mm
, mem
);
323 * This routine assumes that the appropriate zone's lru lock is already held
325 void mem_cgroup_move_lists(struct page
*page
, enum lru_list lru
)
327 struct page_cgroup
*pc
;
328 struct mem_cgroup_per_zone
*mz
;
331 if (mem_cgroup_subsys
.disabled
)
335 * We cannot lock_page_cgroup while holding zone's lru_lock,
336 * because other holders of lock_page_cgroup can be interrupted
337 * with an attempt to rotate_reclaimable_page. But we cannot
338 * safely get to page_cgroup without it, so just try_lock it:
339 * mem_cgroup_isolate_pages allows for page left on wrong list.
341 pc
= lookup_page_cgroup(page
);
342 if (!trylock_page_cgroup(pc
))
344 if (pc
&& PageCgroupUsed(pc
)) {
345 mz
= page_cgroup_zoneinfo(pc
);
346 spin_lock_irqsave(&mz
->lru_lock
, flags
);
347 __mem_cgroup_move_lists(pc
, lru
);
348 spin_unlock_irqrestore(&mz
->lru_lock
, flags
);
350 unlock_page_cgroup(pc
);
354 * Calculate mapped_ratio under memory controller. This will be used in
355 * vmscan.c for deteremining we have to reclaim mapped pages.
357 int mem_cgroup_calc_mapped_ratio(struct mem_cgroup
*mem
)
362 * usage is recorded in bytes. But, here, we assume the number of
363 * physical pages can be represented by "long" on any arch.
365 total
= (long) (mem
->res
.usage
>> PAGE_SHIFT
) + 1L;
366 rss
= (long)mem_cgroup_read_stat(&mem
->stat
, MEM_CGROUP_STAT_RSS
);
367 return (int)((rss
* 100L) / total
);
371 * prev_priority control...this will be used in memory reclaim path.
373 int mem_cgroup_get_reclaim_priority(struct mem_cgroup
*mem
)
375 return mem
->prev_priority
;
378 void mem_cgroup_note_reclaim_priority(struct mem_cgroup
*mem
, int priority
)
380 if (priority
< mem
->prev_priority
)
381 mem
->prev_priority
= priority
;
384 void mem_cgroup_record_reclaim_priority(struct mem_cgroup
*mem
, int priority
)
386 mem
->prev_priority
= priority
;
390 * Calculate # of pages to be scanned in this priority/zone.
393 * priority starts from "DEF_PRIORITY" and decremented in each loop.
394 * (see include/linux/mmzone.h)
397 long mem_cgroup_calc_reclaim(struct mem_cgroup
*mem
, struct zone
*zone
,
398 int priority
, enum lru_list lru
)
401 int nid
= zone
->zone_pgdat
->node_id
;
402 int zid
= zone_idx(zone
);
403 struct mem_cgroup_per_zone
*mz
= mem_cgroup_zoneinfo(mem
, nid
, zid
);
405 nr_pages
= MEM_CGROUP_ZSTAT(mz
, lru
);
407 return (nr_pages
>> priority
);
410 unsigned long mem_cgroup_isolate_pages(unsigned long nr_to_scan
,
411 struct list_head
*dst
,
412 unsigned long *scanned
, int order
,
413 int mode
, struct zone
*z
,
414 struct mem_cgroup
*mem_cont
,
415 int active
, int file
)
417 unsigned long nr_taken
= 0;
421 struct list_head
*src
;
422 struct page_cgroup
*pc
, *tmp
;
423 int nid
= z
->zone_pgdat
->node_id
;
424 int zid
= zone_idx(z
);
425 struct mem_cgroup_per_zone
*mz
;
426 int lru
= LRU_FILE
* !!file
+ !!active
;
429 mz
= mem_cgroup_zoneinfo(mem_cont
, nid
, zid
);
430 src
= &mz
->lists
[lru
];
432 spin_lock(&mz
->lru_lock
);
434 list_for_each_entry_safe_reverse(pc
, tmp
, src
, lru
) {
435 if (scan
>= nr_to_scan
)
437 if (unlikely(!PageCgroupUsed(pc
)))
441 if (unlikely(!PageLRU(page
)))
445 * TODO: play better with lumpy reclaim, grabbing anything.
447 if (PageUnevictable(page
) ||
448 (PageActive(page
) && !active
) ||
449 (!PageActive(page
) && active
)) {
450 __mem_cgroup_move_lists(pc
, page_lru(page
));
455 list_move(&pc
->lru
, &pc_list
);
457 if (__isolate_lru_page(page
, mode
, file
) == 0) {
458 list_move(&page
->lru
, dst
);
463 list_splice(&pc_list
, src
);
464 spin_unlock(&mz
->lru_lock
);
472 * mem_cgroup_try_charge - get charge of PAGE_SIZE.
473 * @mm: an mm_struct which is charged against. (when *memcg is NULL)
474 * @gfp_mask: gfp_mask for reclaim.
475 * @memcg: a pointer to memory cgroup which is charged against.
477 * charge against memory cgroup pointed by *memcg. if *memcg == NULL, estimated
478 * memory cgroup from @mm is got and stored in *memcg.
480 * Returns 0 if success. -ENOMEM at failure.
483 int mem_cgroup_try_charge(struct mm_struct
*mm
,
484 gfp_t gfp_mask
, struct mem_cgroup
**memcg
)
486 struct mem_cgroup
*mem
;
487 int nr_retries
= MEM_CGROUP_RECLAIM_RETRIES
;
489 * We always charge the cgroup the mm_struct belongs to.
490 * The mm_struct's mem_cgroup changes on task migration if the
491 * thread group leader migrates. It's possible that mm is not
492 * set, if so charge the init_mm (happens for pagecache usage).
494 if (likely(!*memcg
)) {
496 mem
= mem_cgroup_from_task(rcu_dereference(mm
->owner
));
497 if (unlikely(!mem
)) {
502 * For every charge from the cgroup, increment reference count
513 while (unlikely(res_counter_charge(&mem
->res
, PAGE_SIZE
))) {
514 if (!(gfp_mask
& __GFP_WAIT
))
517 if (try_to_free_mem_cgroup_pages(mem
, gfp_mask
))
521 * try_to_free_mem_cgroup_pages() might not give us a full
522 * picture of reclaim. Some pages are reclaimed and might be
523 * moved to swap cache or just unmapped from the cgroup.
524 * Check the limit again to see if the reclaim reduced the
525 * current usage of the cgroup before giving up
527 if (res_counter_check_under_limit(&mem
->res
))
531 mem_cgroup_out_of_memory(mem
, gfp_mask
);
542 * commit a charge got by mem_cgroup_try_charge() and makes page_cgroup to be
543 * USED state. If already USED, uncharge and return.
546 static void __mem_cgroup_commit_charge(struct mem_cgroup
*mem
,
547 struct page_cgroup
*pc
,
548 enum charge_type ctype
)
550 struct mem_cgroup_per_zone
*mz
;
553 /* try_charge() can return NULL to *memcg, taking care of it. */
557 lock_page_cgroup(pc
);
558 if (unlikely(PageCgroupUsed(pc
))) {
559 unlock_page_cgroup(pc
);
560 res_counter_uncharge(&mem
->res
, PAGE_SIZE
);
564 pc
->mem_cgroup
= mem
;
566 * If a page is accounted as a page cache, insert to inactive list.
567 * If anon, insert to active list.
569 pc
->flags
= pcg_default_flags
[ctype
];
571 mz
= page_cgroup_zoneinfo(pc
);
573 spin_lock_irqsave(&mz
->lru_lock
, flags
);
574 __mem_cgroup_add_list(mz
, pc
);
575 spin_unlock_irqrestore(&mz
->lru_lock
, flags
);
576 unlock_page_cgroup(pc
);
580 * Charge the memory controller for page usage.
582 * 0 if the charge was successful
583 * < 0 if the cgroup is over its limit
585 static int mem_cgroup_charge_common(struct page
*page
, struct mm_struct
*mm
,
586 gfp_t gfp_mask
, enum charge_type ctype
,
587 struct mem_cgroup
*memcg
)
589 struct mem_cgroup
*mem
;
590 struct page_cgroup
*pc
;
593 pc
= lookup_page_cgroup(page
);
594 /* can happen at boot */
600 ret
= mem_cgroup_try_charge(mm
, gfp_mask
, &mem
);
604 __mem_cgroup_commit_charge(mem
, pc
, ctype
);
608 int mem_cgroup_newpage_charge(struct page
*page
,
609 struct mm_struct
*mm
, gfp_t gfp_mask
)
611 if (mem_cgroup_subsys
.disabled
)
613 if (PageCompound(page
))
616 * If already mapped, we don't have to account.
617 * If page cache, page->mapping has address_space.
618 * But page->mapping may have out-of-use anon_vma pointer,
619 * detecit it by PageAnon() check. newly-mapped-anon's page->mapping
622 if (page_mapped(page
) || (page
->mapping
&& !PageAnon(page
)))
626 return mem_cgroup_charge_common(page
, mm
, gfp_mask
,
627 MEM_CGROUP_CHARGE_TYPE_MAPPED
, NULL
);
631 * same as mem_cgroup_newpage_charge(), now.
632 * But what we assume is different from newpage, and this is special case.
633 * treat this in special function. easy for maintenance.
636 int mem_cgroup_charge_migrate_fixup(struct page
*page
,
637 struct mm_struct
*mm
, gfp_t gfp_mask
)
639 if (mem_cgroup_subsys
.disabled
)
642 if (PageCompound(page
))
645 if (page_mapped(page
) || (page
->mapping
&& !PageAnon(page
)))
651 return mem_cgroup_charge_common(page
, mm
, gfp_mask
,
652 MEM_CGROUP_CHARGE_TYPE_MAPPED
, NULL
);
658 int mem_cgroup_cache_charge(struct page
*page
, struct mm_struct
*mm
,
661 if (mem_cgroup_subsys
.disabled
)
663 if (PageCompound(page
))
666 * Corner case handling. This is called from add_to_page_cache()
667 * in usual. But some FS (shmem) precharges this page before calling it
668 * and call add_to_page_cache() with GFP_NOWAIT.
670 * For GFP_NOWAIT case, the page may be pre-charged before calling
671 * add_to_page_cache(). (See shmem.c) check it here and avoid to call
672 * charge twice. (It works but has to pay a bit larger cost.)
674 if (!(gfp_mask
& __GFP_WAIT
)) {
675 struct page_cgroup
*pc
;
678 pc
= lookup_page_cgroup(page
);
681 lock_page_cgroup(pc
);
682 if (PageCgroupUsed(pc
)) {
683 unlock_page_cgroup(pc
);
686 unlock_page_cgroup(pc
);
692 if (page_is_file_cache(page
))
693 return mem_cgroup_charge_common(page
, mm
, gfp_mask
,
694 MEM_CGROUP_CHARGE_TYPE_CACHE
, NULL
);
696 return mem_cgroup_charge_common(page
, mm
, gfp_mask
,
697 MEM_CGROUP_CHARGE_TYPE_SHMEM
, NULL
);
701 void mem_cgroup_commit_charge_swapin(struct page
*page
, struct mem_cgroup
*ptr
)
703 struct page_cgroup
*pc
;
705 if (mem_cgroup_subsys
.disabled
)
709 pc
= lookup_page_cgroup(page
);
710 __mem_cgroup_commit_charge(ptr
, pc
, MEM_CGROUP_CHARGE_TYPE_MAPPED
);
713 void mem_cgroup_cancel_charge_swapin(struct mem_cgroup
*mem
)
715 if (mem_cgroup_subsys
.disabled
)
719 res_counter_uncharge(&mem
->res
, PAGE_SIZE
);
725 * uncharge if !page_mapped(page)
728 __mem_cgroup_uncharge_common(struct page
*page
, enum charge_type ctype
)
730 struct page_cgroup
*pc
;
731 struct mem_cgroup
*mem
;
732 struct mem_cgroup_per_zone
*mz
;
735 if (mem_cgroup_subsys
.disabled
)
739 * Check if our page_cgroup is valid
741 pc
= lookup_page_cgroup(page
);
742 if (unlikely(!pc
|| !PageCgroupUsed(pc
)))
745 lock_page_cgroup(pc
);
746 if ((ctype
== MEM_CGROUP_CHARGE_TYPE_MAPPED
&& page_mapped(page
))
747 || !PageCgroupUsed(pc
)) {
748 /* This happens at race in zap_pte_range() and do_swap_page()*/
749 unlock_page_cgroup(pc
);
752 ClearPageCgroupUsed(pc
);
753 mem
= pc
->mem_cgroup
;
755 mz
= page_cgroup_zoneinfo(pc
);
756 spin_lock_irqsave(&mz
->lru_lock
, flags
);
757 __mem_cgroup_remove_list(mz
, pc
);
758 spin_unlock_irqrestore(&mz
->lru_lock
, flags
);
759 unlock_page_cgroup(pc
);
761 res_counter_uncharge(&mem
->res
, PAGE_SIZE
);
767 void mem_cgroup_uncharge_page(struct page
*page
)
770 if (page_mapped(page
))
772 if (page
->mapping
&& !PageAnon(page
))
774 __mem_cgroup_uncharge_common(page
, MEM_CGROUP_CHARGE_TYPE_MAPPED
);
777 void mem_cgroup_uncharge_cache_page(struct page
*page
)
779 VM_BUG_ON(page_mapped(page
));
780 VM_BUG_ON(page
->mapping
);
781 __mem_cgroup_uncharge_common(page
, MEM_CGROUP_CHARGE_TYPE_CACHE
);
785 * Before starting migration, account against new page.
787 int mem_cgroup_prepare_migration(struct page
*page
, struct page
*newpage
)
789 struct page_cgroup
*pc
;
790 struct mem_cgroup
*mem
= NULL
;
791 enum charge_type ctype
= MEM_CGROUP_CHARGE_TYPE_MAPPED
;
794 if (mem_cgroup_subsys
.disabled
)
797 pc
= lookup_page_cgroup(page
);
798 lock_page_cgroup(pc
);
799 if (PageCgroupUsed(pc
)) {
800 mem
= pc
->mem_cgroup
;
802 if (PageCgroupCache(pc
)) {
803 if (page_is_file_cache(page
))
804 ctype
= MEM_CGROUP_CHARGE_TYPE_CACHE
;
806 ctype
= MEM_CGROUP_CHARGE_TYPE_SHMEM
;
809 unlock_page_cgroup(pc
);
811 ret
= mem_cgroup_charge_common(newpage
, NULL
, GFP_KERNEL
,
818 /* remove redundant charge if migration failed*/
819 void mem_cgroup_end_migration(struct page
*newpage
)
822 * At success, page->mapping is not NULL.
823 * special rollback care is necessary when
824 * 1. at migration failure. (newpage->mapping is cleared in this case)
825 * 2. the newpage was moved but not remapped again because the task
826 * exits and the newpage is obsolete. In this case, the new page
827 * may be a swapcache. So, we just call mem_cgroup_uncharge_page()
828 * always for avoiding mess. The page_cgroup will be removed if
829 * unnecessary. File cache pages is still on radix-tree. Don't
832 if (!newpage
->mapping
)
833 __mem_cgroup_uncharge_common(newpage
,
834 MEM_CGROUP_CHARGE_TYPE_FORCE
);
835 else if (PageAnon(newpage
))
836 mem_cgroup_uncharge_page(newpage
);
840 * A call to try to shrink memory usage under specified resource controller.
841 * This is typically used for page reclaiming for shmem for reducing side
842 * effect of page allocation from shmem, which is used by some mem_cgroup.
844 int mem_cgroup_shrink_usage(struct mm_struct
*mm
, gfp_t gfp_mask
)
846 struct mem_cgroup
*mem
;
848 int retry
= MEM_CGROUP_RECLAIM_RETRIES
;
850 if (mem_cgroup_subsys
.disabled
)
856 mem
= mem_cgroup_from_task(rcu_dereference(mm
->owner
));
857 if (unlikely(!mem
)) {
865 progress
= try_to_free_mem_cgroup_pages(mem
, gfp_mask
);
866 progress
+= res_counter_check_under_limit(&mem
->res
);
867 } while (!progress
&& --retry
);
875 static int mem_cgroup_resize_limit(struct mem_cgroup
*memcg
,
876 unsigned long long val
)
879 int retry_count
= MEM_CGROUP_RECLAIM_RETRIES
;
883 while (res_counter_set_limit(&memcg
->res
, val
)) {
884 if (signal_pending(current
)) {
892 progress
= try_to_free_mem_cgroup_pages(memcg
, GFP_KERNEL
);
901 * This routine traverse page_cgroup in given list and drop them all.
902 * *And* this routine doesn't reclaim page itself, just removes page_cgroup.
904 #define FORCE_UNCHARGE_BATCH (128)
905 static void mem_cgroup_force_empty_list(struct mem_cgroup
*mem
,
906 struct mem_cgroup_per_zone
*mz
,
909 struct page_cgroup
*pc
;
911 int count
= FORCE_UNCHARGE_BATCH
;
913 struct list_head
*list
;
915 list
= &mz
->lists
[lru
];
917 spin_lock_irqsave(&mz
->lru_lock
, flags
);
918 while (!list_empty(list
)) {
919 pc
= list_entry(list
->prev
, struct page_cgroup
, lru
);
921 if (!PageCgroupUsed(pc
))
924 spin_unlock_irqrestore(&mz
->lru_lock
, flags
);
926 * Check if this page is on LRU. !LRU page can be found
927 * if it's under page migration.
930 __mem_cgroup_uncharge_common(page
,
931 MEM_CGROUP_CHARGE_TYPE_FORCE
);
934 count
= FORCE_UNCHARGE_BATCH
;
938 spin_lock_irqsave(&mz
->lru_lock
, flags
);
941 spin_lock_irqsave(&mz
->lru_lock
, flags
);
943 spin_unlock_irqrestore(&mz
->lru_lock
, flags
);
947 * make mem_cgroup's charge to be 0 if there is no task.
948 * This enables deleting this mem_cgroup.
950 static int mem_cgroup_force_empty(struct mem_cgroup
*mem
)
957 * page reclaim code (kswapd etc..) will move pages between
958 * active_list <-> inactive_list while we don't take a lock.
959 * So, we have to do loop here until all lists are empty.
961 while (mem
->res
.usage
> 0) {
962 if (atomic_read(&mem
->css
.cgroup
->count
) > 0)
964 /* This is for making all *used* pages to be on LRU. */
966 for_each_node_state(node
, N_POSSIBLE
)
967 for (zid
= 0; zid
< MAX_NR_ZONES
; zid
++) {
968 struct mem_cgroup_per_zone
*mz
;
970 mz
= mem_cgroup_zoneinfo(mem
, node
, zid
);
972 mem_cgroup_force_empty_list(mem
, mz
, l
);
982 static u64
mem_cgroup_read(struct cgroup
*cont
, struct cftype
*cft
)
984 return res_counter_read_u64(&mem_cgroup_from_cont(cont
)->res
,
988 * The user of this function is...
991 static int mem_cgroup_write(struct cgroup
*cont
, struct cftype
*cft
,
994 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cont
);
995 unsigned long long val
;
998 switch (cft
->private) {
1000 /* This function does all necessary parse...reuse it */
1001 ret
= res_counter_memparse_write_strategy(buffer
, &val
);
1003 ret
= mem_cgroup_resize_limit(memcg
, val
);
1006 ret
= -EINVAL
; /* should be BUG() ? */
1012 static int mem_cgroup_reset(struct cgroup
*cont
, unsigned int event
)
1014 struct mem_cgroup
*mem
;
1016 mem
= mem_cgroup_from_cont(cont
);
1019 res_counter_reset_max(&mem
->res
);
1022 res_counter_reset_failcnt(&mem
->res
);
1028 static int mem_force_empty_write(struct cgroup
*cont
, unsigned int event
)
1030 return mem_cgroup_force_empty(mem_cgroup_from_cont(cont
));
1033 static const struct mem_cgroup_stat_desc
{
1036 } mem_cgroup_stat_desc
[] = {
1037 [MEM_CGROUP_STAT_CACHE
] = { "cache", PAGE_SIZE
, },
1038 [MEM_CGROUP_STAT_RSS
] = { "rss", PAGE_SIZE
, },
1039 [MEM_CGROUP_STAT_PGPGIN_COUNT
] = {"pgpgin", 1, },
1040 [MEM_CGROUP_STAT_PGPGOUT_COUNT
] = {"pgpgout", 1, },
1043 static int mem_control_stat_show(struct cgroup
*cont
, struct cftype
*cft
,
1044 struct cgroup_map_cb
*cb
)
1046 struct mem_cgroup
*mem_cont
= mem_cgroup_from_cont(cont
);
1047 struct mem_cgroup_stat
*stat
= &mem_cont
->stat
;
1050 for (i
= 0; i
< ARRAY_SIZE(stat
->cpustat
[0].count
); i
++) {
1053 val
= mem_cgroup_read_stat(stat
, i
);
1054 val
*= mem_cgroup_stat_desc
[i
].unit
;
1055 cb
->fill(cb
, mem_cgroup_stat_desc
[i
].msg
, val
);
1057 /* showing # of active pages */
1059 unsigned long active_anon
, inactive_anon
;
1060 unsigned long active_file
, inactive_file
;
1061 unsigned long unevictable
;
1063 inactive_anon
= mem_cgroup_get_all_zonestat(mem_cont
,
1065 active_anon
= mem_cgroup_get_all_zonestat(mem_cont
,
1067 inactive_file
= mem_cgroup_get_all_zonestat(mem_cont
,
1069 active_file
= mem_cgroup_get_all_zonestat(mem_cont
,
1071 unevictable
= mem_cgroup_get_all_zonestat(mem_cont
,
1074 cb
->fill(cb
, "active_anon", (active_anon
) * PAGE_SIZE
);
1075 cb
->fill(cb
, "inactive_anon", (inactive_anon
) * PAGE_SIZE
);
1076 cb
->fill(cb
, "active_file", (active_file
) * PAGE_SIZE
);
1077 cb
->fill(cb
, "inactive_file", (inactive_file
) * PAGE_SIZE
);
1078 cb
->fill(cb
, "unevictable", unevictable
* PAGE_SIZE
);
1084 static struct cftype mem_cgroup_files
[] = {
1086 .name
= "usage_in_bytes",
1087 .private = RES_USAGE
,
1088 .read_u64
= mem_cgroup_read
,
1091 .name
= "max_usage_in_bytes",
1092 .private = RES_MAX_USAGE
,
1093 .trigger
= mem_cgroup_reset
,
1094 .read_u64
= mem_cgroup_read
,
1097 .name
= "limit_in_bytes",
1098 .private = RES_LIMIT
,
1099 .write_string
= mem_cgroup_write
,
1100 .read_u64
= mem_cgroup_read
,
1104 .private = RES_FAILCNT
,
1105 .trigger
= mem_cgroup_reset
,
1106 .read_u64
= mem_cgroup_read
,
1109 .name
= "force_empty",
1110 .trigger
= mem_force_empty_write
,
1114 .read_map
= mem_control_stat_show
,
1118 static int alloc_mem_cgroup_per_zone_info(struct mem_cgroup
*mem
, int node
)
1120 struct mem_cgroup_per_node
*pn
;
1121 struct mem_cgroup_per_zone
*mz
;
1123 int zone
, tmp
= node
;
1125 * This routine is called against possible nodes.
1126 * But it's BUG to call kmalloc() against offline node.
1128 * TODO: this routine can waste much memory for nodes which will
1129 * never be onlined. It's better to use memory hotplug callback
1132 if (!node_state(node
, N_NORMAL_MEMORY
))
1134 pn
= kmalloc_node(sizeof(*pn
), GFP_KERNEL
, tmp
);
1138 mem
->info
.nodeinfo
[node
] = pn
;
1139 memset(pn
, 0, sizeof(*pn
));
1141 for (zone
= 0; zone
< MAX_NR_ZONES
; zone
++) {
1142 mz
= &pn
->zoneinfo
[zone
];
1143 spin_lock_init(&mz
->lru_lock
);
1145 INIT_LIST_HEAD(&mz
->lists
[l
]);
1150 static void free_mem_cgroup_per_zone_info(struct mem_cgroup
*mem
, int node
)
1152 kfree(mem
->info
.nodeinfo
[node
]);
1155 static struct mem_cgroup
*mem_cgroup_alloc(void)
1157 struct mem_cgroup
*mem
;
1159 if (sizeof(*mem
) < PAGE_SIZE
)
1160 mem
= kmalloc(sizeof(*mem
), GFP_KERNEL
);
1162 mem
= vmalloc(sizeof(*mem
));
1165 memset(mem
, 0, sizeof(*mem
));
1169 static void mem_cgroup_free(struct mem_cgroup
*mem
)
1171 if (sizeof(*mem
) < PAGE_SIZE
)
1178 static struct cgroup_subsys_state
*
1179 mem_cgroup_create(struct cgroup_subsys
*ss
, struct cgroup
*cont
)
1181 struct mem_cgroup
*mem
;
1184 if (unlikely((cont
->parent
) == NULL
)) {
1185 mem
= &init_mem_cgroup
;
1187 mem
= mem_cgroup_alloc();
1189 return ERR_PTR(-ENOMEM
);
1192 res_counter_init(&mem
->res
);
1194 for_each_node_state(node
, N_POSSIBLE
)
1195 if (alloc_mem_cgroup_per_zone_info(mem
, node
))
1200 for_each_node_state(node
, N_POSSIBLE
)
1201 free_mem_cgroup_per_zone_info(mem
, node
);
1202 if (cont
->parent
!= NULL
)
1203 mem_cgroup_free(mem
);
1204 return ERR_PTR(-ENOMEM
);
1207 static void mem_cgroup_pre_destroy(struct cgroup_subsys
*ss
,
1208 struct cgroup
*cont
)
1210 struct mem_cgroup
*mem
= mem_cgroup_from_cont(cont
);
1211 mem_cgroup_force_empty(mem
);
1214 static void mem_cgroup_destroy(struct cgroup_subsys
*ss
,
1215 struct cgroup
*cont
)
1218 struct mem_cgroup
*mem
= mem_cgroup_from_cont(cont
);
1220 for_each_node_state(node
, N_POSSIBLE
)
1221 free_mem_cgroup_per_zone_info(mem
, node
);
1223 mem_cgroup_free(mem_cgroup_from_cont(cont
));
1226 static int mem_cgroup_populate(struct cgroup_subsys
*ss
,
1227 struct cgroup
*cont
)
1229 return cgroup_add_files(cont
, ss
, mem_cgroup_files
,
1230 ARRAY_SIZE(mem_cgroup_files
));
1233 static void mem_cgroup_move_task(struct cgroup_subsys
*ss
,
1234 struct cgroup
*cont
,
1235 struct cgroup
*old_cont
,
1236 struct task_struct
*p
)
1238 struct mm_struct
*mm
;
1239 struct mem_cgroup
*mem
, *old_mem
;
1241 mm
= get_task_mm(p
);
1245 mem
= mem_cgroup_from_cont(cont
);
1246 old_mem
= mem_cgroup_from_cont(old_cont
);
1249 * Only thread group leaders are allowed to migrate, the mm_struct is
1250 * in effect owned by the leader
1252 if (!thread_group_leader(p
))
1259 struct cgroup_subsys mem_cgroup_subsys
= {
1261 .subsys_id
= mem_cgroup_subsys_id
,
1262 .create
= mem_cgroup_create
,
1263 .pre_destroy
= mem_cgroup_pre_destroy
,
1264 .destroy
= mem_cgroup_destroy
,
1265 .populate
= mem_cgroup_populate
,
1266 .attach
= mem_cgroup_move_task
,