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
, bool hot
)
264 if (PageCgroupUnevictable(pc
))
265 lru
= LRU_UNEVICTABLE
;
267 if (PageCgroupActive(pc
))
269 if (PageCgroupFile(pc
))
273 MEM_CGROUP_ZSTAT(mz
, lru
) += 1;
275 list_add(&pc
->lru
, &mz
->lists
[lru
]);
277 list_add_tail(&pc
->lru
, &mz
->lists
[lru
]);
279 mem_cgroup_charge_statistics(pc
->mem_cgroup
, pc
, true);
282 static void __mem_cgroup_move_lists(struct page_cgroup
*pc
, enum lru_list lru
)
284 struct mem_cgroup_per_zone
*mz
= page_cgroup_zoneinfo(pc
);
285 int active
= PageCgroupActive(pc
);
286 int file
= PageCgroupFile(pc
);
287 int unevictable
= PageCgroupUnevictable(pc
);
288 enum lru_list from
= unevictable
? LRU_UNEVICTABLE
:
289 (LRU_FILE
* !!file
+ !!active
);
294 MEM_CGROUP_ZSTAT(mz
, from
) -= 1;
296 * However this is done under mz->lru_lock, another flags, which
297 * are not related to LRU, will be modified from out-of-lock.
298 * We have to use atomic set/clear flags.
300 if (is_unevictable_lru(lru
)) {
301 ClearPageCgroupActive(pc
);
302 SetPageCgroupUnevictable(pc
);
304 if (is_active_lru(lru
))
305 SetPageCgroupActive(pc
);
307 ClearPageCgroupActive(pc
);
308 ClearPageCgroupUnevictable(pc
);
311 MEM_CGROUP_ZSTAT(mz
, lru
) += 1;
312 list_move(&pc
->lru
, &mz
->lists
[lru
]);
315 int task_in_mem_cgroup(struct task_struct
*task
, const struct mem_cgroup
*mem
)
320 ret
= task
->mm
&& mm_match_cgroup(task
->mm
, mem
);
326 * This routine assumes that the appropriate zone's lru lock is already held
328 void mem_cgroup_move_lists(struct page
*page
, enum lru_list lru
)
330 struct page_cgroup
*pc
;
331 struct mem_cgroup_per_zone
*mz
;
334 if (mem_cgroup_subsys
.disabled
)
338 * We cannot lock_page_cgroup while holding zone's lru_lock,
339 * because other holders of lock_page_cgroup can be interrupted
340 * with an attempt to rotate_reclaimable_page. But we cannot
341 * safely get to page_cgroup without it, so just try_lock it:
342 * mem_cgroup_isolate_pages allows for page left on wrong list.
344 pc
= lookup_page_cgroup(page
);
345 if (!trylock_page_cgroup(pc
))
347 if (pc
&& PageCgroupUsed(pc
)) {
348 mz
= page_cgroup_zoneinfo(pc
);
349 spin_lock_irqsave(&mz
->lru_lock
, flags
);
350 __mem_cgroup_move_lists(pc
, lru
);
351 spin_unlock_irqrestore(&mz
->lru_lock
, flags
);
353 unlock_page_cgroup(pc
);
357 * Calculate mapped_ratio under memory controller. This will be used in
358 * vmscan.c for deteremining we have to reclaim mapped pages.
360 int mem_cgroup_calc_mapped_ratio(struct mem_cgroup
*mem
)
365 * usage is recorded in bytes. But, here, we assume the number of
366 * physical pages can be represented by "long" on any arch.
368 total
= (long) (mem
->res
.usage
>> PAGE_SHIFT
) + 1L;
369 rss
= (long)mem_cgroup_read_stat(&mem
->stat
, MEM_CGROUP_STAT_RSS
);
370 return (int)((rss
* 100L) / total
);
374 * prev_priority control...this will be used in memory reclaim path.
376 int mem_cgroup_get_reclaim_priority(struct mem_cgroup
*mem
)
378 return mem
->prev_priority
;
381 void mem_cgroup_note_reclaim_priority(struct mem_cgroup
*mem
, int priority
)
383 if (priority
< mem
->prev_priority
)
384 mem
->prev_priority
= priority
;
387 void mem_cgroup_record_reclaim_priority(struct mem_cgroup
*mem
, int priority
)
389 mem
->prev_priority
= priority
;
393 * Calculate # of pages to be scanned in this priority/zone.
396 * priority starts from "DEF_PRIORITY" and decremented in each loop.
397 * (see include/linux/mmzone.h)
400 long mem_cgroup_calc_reclaim(struct mem_cgroup
*mem
, struct zone
*zone
,
401 int priority
, enum lru_list lru
)
404 int nid
= zone
->zone_pgdat
->node_id
;
405 int zid
= zone_idx(zone
);
406 struct mem_cgroup_per_zone
*mz
= mem_cgroup_zoneinfo(mem
, nid
, zid
);
408 nr_pages
= MEM_CGROUP_ZSTAT(mz
, lru
);
410 return (nr_pages
>> priority
);
413 unsigned long mem_cgroup_isolate_pages(unsigned long nr_to_scan
,
414 struct list_head
*dst
,
415 unsigned long *scanned
, int order
,
416 int mode
, struct zone
*z
,
417 struct mem_cgroup
*mem_cont
,
418 int active
, int file
)
420 unsigned long nr_taken
= 0;
424 struct list_head
*src
;
425 struct page_cgroup
*pc
, *tmp
;
426 int nid
= z
->zone_pgdat
->node_id
;
427 int zid
= zone_idx(z
);
428 struct mem_cgroup_per_zone
*mz
;
429 int lru
= LRU_FILE
* !!file
+ !!active
;
432 mz
= mem_cgroup_zoneinfo(mem_cont
, nid
, zid
);
433 src
= &mz
->lists
[lru
];
435 spin_lock(&mz
->lru_lock
);
437 list_for_each_entry_safe_reverse(pc
, tmp
, src
, lru
) {
438 if (scan
>= nr_to_scan
)
440 if (unlikely(!PageCgroupUsed(pc
)))
444 if (unlikely(!PageLRU(page
)))
448 * TODO: play better with lumpy reclaim, grabbing anything.
450 if (PageUnevictable(page
) ||
451 (PageActive(page
) && !active
) ||
452 (!PageActive(page
) && active
)) {
453 __mem_cgroup_move_lists(pc
, page_lru(page
));
458 list_move(&pc
->lru
, &pc_list
);
460 if (__isolate_lru_page(page
, mode
, file
) == 0) {
461 list_move(&page
->lru
, dst
);
466 list_splice(&pc_list
, src
);
467 spin_unlock(&mz
->lru_lock
);
474 * Unlike exported interface, "oom" parameter is added. if oom==true,
475 * oom-killer can be invoked.
477 static int __mem_cgroup_try_charge(struct mm_struct
*mm
,
478 gfp_t gfp_mask
, struct mem_cgroup
**memcg
, bool oom
)
480 struct mem_cgroup
*mem
;
481 int nr_retries
= MEM_CGROUP_RECLAIM_RETRIES
;
483 * We always charge the cgroup the mm_struct belongs to.
484 * The mm_struct's mem_cgroup changes on task migration if the
485 * thread group leader migrates. It's possible that mm is not
486 * set, if so charge the init_mm (happens for pagecache usage).
488 if (likely(!*memcg
)) {
490 mem
= mem_cgroup_from_task(rcu_dereference(mm
->owner
));
491 if (unlikely(!mem
)) {
496 * For every charge from the cgroup, increment reference count
507 while (unlikely(res_counter_charge(&mem
->res
, PAGE_SIZE
))) {
508 if (!(gfp_mask
& __GFP_WAIT
))
511 if (try_to_free_mem_cgroup_pages(mem
, gfp_mask
))
515 * try_to_free_mem_cgroup_pages() might not give us a full
516 * picture of reclaim. Some pages are reclaimed and might be
517 * moved to swap cache or just unmapped from the cgroup.
518 * Check the limit again to see if the reclaim reduced the
519 * current usage of the cgroup before giving up
521 if (res_counter_check_under_limit(&mem
->res
))
526 mem_cgroup_out_of_memory(mem
, gfp_mask
);
537 * mem_cgroup_try_charge - get charge of PAGE_SIZE.
538 * @mm: an mm_struct which is charged against. (when *memcg is NULL)
539 * @gfp_mask: gfp_mask for reclaim.
540 * @memcg: a pointer to memory cgroup which is charged against.
542 * charge against memory cgroup pointed by *memcg. if *memcg == NULL, estimated
543 * memory cgroup from @mm is got and stored in *memcg.
545 * Returns 0 if success. -ENOMEM at failure.
546 * This call can invoke OOM-Killer.
549 int mem_cgroup_try_charge(struct mm_struct
*mm
,
550 gfp_t mask
, struct mem_cgroup
**memcg
)
552 return __mem_cgroup_try_charge(mm
, mask
, memcg
, true);
556 * commit a charge got by mem_cgroup_try_charge() and makes page_cgroup to be
557 * USED state. If already USED, uncharge and return.
560 static void __mem_cgroup_commit_charge(struct mem_cgroup
*mem
,
561 struct page_cgroup
*pc
,
562 enum charge_type ctype
)
564 struct mem_cgroup_per_zone
*mz
;
567 /* try_charge() can return NULL to *memcg, taking care of it. */
571 lock_page_cgroup(pc
);
572 if (unlikely(PageCgroupUsed(pc
))) {
573 unlock_page_cgroup(pc
);
574 res_counter_uncharge(&mem
->res
, PAGE_SIZE
);
578 pc
->mem_cgroup
= mem
;
580 * If a page is accounted as a page cache, insert to inactive list.
581 * If anon, insert to active list.
583 pc
->flags
= pcg_default_flags
[ctype
];
585 mz
= page_cgroup_zoneinfo(pc
);
587 spin_lock_irqsave(&mz
->lru_lock
, flags
);
588 __mem_cgroup_add_list(mz
, pc
, true);
589 spin_unlock_irqrestore(&mz
->lru_lock
, flags
);
590 unlock_page_cgroup(pc
);
594 * mem_cgroup_move_account - move account of the page
595 * @pc: page_cgroup of the page.
596 * @from: mem_cgroup which the page is moved from.
597 * @to: mem_cgroup which the page is moved to. @from != @to.
599 * The caller must confirm following.
601 * 2. lru_lock of old mem_cgroup(@from) should be held.
603 * returns 0 at success,
604 * returns -EBUSY when lock is busy or "pc" is unstable.
606 * This function does "uncharge" from old cgroup but doesn't do "charge" to
607 * new cgroup. It should be done by a caller.
610 static int mem_cgroup_move_account(struct page_cgroup
*pc
,
611 struct mem_cgroup
*from
, struct mem_cgroup
*to
)
613 struct mem_cgroup_per_zone
*from_mz
, *to_mz
;
617 VM_BUG_ON(!irqs_disabled());
618 VM_BUG_ON(from
== to
);
620 nid
= page_cgroup_nid(pc
);
621 zid
= page_cgroup_zid(pc
);
622 from_mz
= mem_cgroup_zoneinfo(from
, nid
, zid
);
623 to_mz
= mem_cgroup_zoneinfo(to
, nid
, zid
);
626 if (!trylock_page_cgroup(pc
))
629 if (!PageCgroupUsed(pc
))
632 if (pc
->mem_cgroup
!= from
)
635 if (spin_trylock(&to_mz
->lru_lock
)) {
636 __mem_cgroup_remove_list(from_mz
, pc
);
638 res_counter_uncharge(&from
->res
, PAGE_SIZE
);
641 __mem_cgroup_add_list(to_mz
, pc
, false);
643 spin_unlock(&to_mz
->lru_lock
);
646 unlock_page_cgroup(pc
);
651 * move charges to its parent.
654 static int mem_cgroup_move_parent(struct page_cgroup
*pc
,
655 struct mem_cgroup
*child
,
658 struct cgroup
*cg
= child
->css
.cgroup
;
659 struct cgroup
*pcg
= cg
->parent
;
660 struct mem_cgroup
*parent
;
661 struct mem_cgroup_per_zone
*mz
;
669 parent
= mem_cgroup_from_cont(pcg
);
671 ret
= __mem_cgroup_try_charge(NULL
, gfp_mask
, &parent
, false);
675 mz
= mem_cgroup_zoneinfo(child
,
676 page_cgroup_nid(pc
), page_cgroup_zid(pc
));
678 spin_lock_irqsave(&mz
->lru_lock
, flags
);
679 ret
= mem_cgroup_move_account(pc
, child
, parent
);
680 spin_unlock_irqrestore(&mz
->lru_lock
, flags
);
682 /* drop extra refcnt */
683 css_put(&parent
->css
);
684 /* uncharge if move fails */
686 res_counter_uncharge(&parent
->res
, PAGE_SIZE
);
692 * Charge the memory controller for page usage.
694 * 0 if the charge was successful
695 * < 0 if the cgroup is over its limit
697 static int mem_cgroup_charge_common(struct page
*page
, struct mm_struct
*mm
,
698 gfp_t gfp_mask
, enum charge_type ctype
,
699 struct mem_cgroup
*memcg
)
701 struct mem_cgroup
*mem
;
702 struct page_cgroup
*pc
;
705 pc
= lookup_page_cgroup(page
);
706 /* can happen at boot */
712 ret
= __mem_cgroup_try_charge(mm
, gfp_mask
, &mem
, true);
716 __mem_cgroup_commit_charge(mem
, pc
, ctype
);
720 int mem_cgroup_newpage_charge(struct page
*page
,
721 struct mm_struct
*mm
, gfp_t gfp_mask
)
723 if (mem_cgroup_subsys
.disabled
)
725 if (PageCompound(page
))
728 * If already mapped, we don't have to account.
729 * If page cache, page->mapping has address_space.
730 * But page->mapping may have out-of-use anon_vma pointer,
731 * detecit it by PageAnon() check. newly-mapped-anon's page->mapping
734 if (page_mapped(page
) || (page
->mapping
&& !PageAnon(page
)))
738 return mem_cgroup_charge_common(page
, mm
, gfp_mask
,
739 MEM_CGROUP_CHARGE_TYPE_MAPPED
, NULL
);
742 int mem_cgroup_cache_charge(struct page
*page
, struct mm_struct
*mm
,
745 if (mem_cgroup_subsys
.disabled
)
747 if (PageCompound(page
))
750 * Corner case handling. This is called from add_to_page_cache()
751 * in usual. But some FS (shmem) precharges this page before calling it
752 * and call add_to_page_cache() with GFP_NOWAIT.
754 * For GFP_NOWAIT case, the page may be pre-charged before calling
755 * add_to_page_cache(). (See shmem.c) check it here and avoid to call
756 * charge twice. (It works but has to pay a bit larger cost.)
758 if (!(gfp_mask
& __GFP_WAIT
)) {
759 struct page_cgroup
*pc
;
762 pc
= lookup_page_cgroup(page
);
765 lock_page_cgroup(pc
);
766 if (PageCgroupUsed(pc
)) {
767 unlock_page_cgroup(pc
);
770 unlock_page_cgroup(pc
);
776 if (page_is_file_cache(page
))
777 return mem_cgroup_charge_common(page
, mm
, gfp_mask
,
778 MEM_CGROUP_CHARGE_TYPE_CACHE
, NULL
);
780 return mem_cgroup_charge_common(page
, mm
, gfp_mask
,
781 MEM_CGROUP_CHARGE_TYPE_SHMEM
, NULL
);
784 void mem_cgroup_commit_charge_swapin(struct page
*page
, struct mem_cgroup
*ptr
)
786 struct page_cgroup
*pc
;
788 if (mem_cgroup_subsys
.disabled
)
792 pc
= lookup_page_cgroup(page
);
793 __mem_cgroup_commit_charge(ptr
, pc
, MEM_CGROUP_CHARGE_TYPE_MAPPED
);
796 void mem_cgroup_cancel_charge_swapin(struct mem_cgroup
*mem
)
798 if (mem_cgroup_subsys
.disabled
)
802 res_counter_uncharge(&mem
->res
, PAGE_SIZE
);
808 * uncharge if !page_mapped(page)
811 __mem_cgroup_uncharge_common(struct page
*page
, enum charge_type ctype
)
813 struct page_cgroup
*pc
;
814 struct mem_cgroup
*mem
;
815 struct mem_cgroup_per_zone
*mz
;
818 if (mem_cgroup_subsys
.disabled
)
822 * Check if our page_cgroup is valid
824 pc
= lookup_page_cgroup(page
);
825 if (unlikely(!pc
|| !PageCgroupUsed(pc
)))
828 lock_page_cgroup(pc
);
829 if ((ctype
== MEM_CGROUP_CHARGE_TYPE_MAPPED
&& page_mapped(page
))
830 || !PageCgroupUsed(pc
)) {
831 /* This happens at race in zap_pte_range() and do_swap_page()*/
832 unlock_page_cgroup(pc
);
835 ClearPageCgroupUsed(pc
);
836 mem
= pc
->mem_cgroup
;
838 mz
= page_cgroup_zoneinfo(pc
);
839 spin_lock_irqsave(&mz
->lru_lock
, flags
);
840 __mem_cgroup_remove_list(mz
, pc
);
841 spin_unlock_irqrestore(&mz
->lru_lock
, flags
);
842 unlock_page_cgroup(pc
);
844 res_counter_uncharge(&mem
->res
, PAGE_SIZE
);
850 void mem_cgroup_uncharge_page(struct page
*page
)
853 if (page_mapped(page
))
855 if (page
->mapping
&& !PageAnon(page
))
857 __mem_cgroup_uncharge_common(page
, MEM_CGROUP_CHARGE_TYPE_MAPPED
);
860 void mem_cgroup_uncharge_cache_page(struct page
*page
)
862 VM_BUG_ON(page_mapped(page
));
863 VM_BUG_ON(page
->mapping
);
864 __mem_cgroup_uncharge_common(page
, MEM_CGROUP_CHARGE_TYPE_CACHE
);
868 * Before starting migration, account PAGE_SIZE to mem_cgroup that the old
871 int mem_cgroup_prepare_migration(struct page
*page
, struct mem_cgroup
**ptr
)
873 struct page_cgroup
*pc
;
874 struct mem_cgroup
*mem
= NULL
;
877 if (mem_cgroup_subsys
.disabled
)
880 pc
= lookup_page_cgroup(page
);
881 lock_page_cgroup(pc
);
882 if (PageCgroupUsed(pc
)) {
883 mem
= pc
->mem_cgroup
;
886 unlock_page_cgroup(pc
);
889 ret
= mem_cgroup_try_charge(NULL
, GFP_HIGHUSER_MOVABLE
, &mem
);
896 /* remove redundant charge if migration failed*/
897 void mem_cgroup_end_migration(struct mem_cgroup
*mem
,
898 struct page
*oldpage
, struct page
*newpage
)
900 struct page
*target
, *unused
;
901 struct page_cgroup
*pc
;
902 enum charge_type ctype
;
907 /* at migration success, oldpage->mapping is NULL. */
908 if (oldpage
->mapping
) {
916 if (PageAnon(target
))
917 ctype
= MEM_CGROUP_CHARGE_TYPE_MAPPED
;
918 else if (page_is_file_cache(target
))
919 ctype
= MEM_CGROUP_CHARGE_TYPE_CACHE
;
921 ctype
= MEM_CGROUP_CHARGE_TYPE_SHMEM
;
923 /* unused page is not on radix-tree now. */
924 if (unused
&& ctype
!= MEM_CGROUP_CHARGE_TYPE_MAPPED
)
925 __mem_cgroup_uncharge_common(unused
, ctype
);
927 pc
= lookup_page_cgroup(target
);
929 * __mem_cgroup_commit_charge() check PCG_USED bit of page_cgroup.
930 * So, double-counting is effectively avoided.
932 __mem_cgroup_commit_charge(mem
, pc
, ctype
);
935 * Both of oldpage and newpage are still under lock_page().
936 * Then, we don't have to care about race in radix-tree.
937 * But we have to be careful that this page is unmapped or not.
939 * There is a case for !page_mapped(). At the start of
940 * migration, oldpage was mapped. But now, it's zapped.
941 * But we know *target* page is not freed/reused under us.
942 * mem_cgroup_uncharge_page() does all necessary checks.
944 if (ctype
== MEM_CGROUP_CHARGE_TYPE_MAPPED
)
945 mem_cgroup_uncharge_page(target
);
949 * A call to try to shrink memory usage under specified resource controller.
950 * This is typically used for page reclaiming for shmem for reducing side
951 * effect of page allocation from shmem, which is used by some mem_cgroup.
953 int mem_cgroup_shrink_usage(struct mm_struct
*mm
, gfp_t gfp_mask
)
955 struct mem_cgroup
*mem
;
957 int retry
= MEM_CGROUP_RECLAIM_RETRIES
;
959 if (mem_cgroup_subsys
.disabled
)
965 mem
= mem_cgroup_from_task(rcu_dereference(mm
->owner
));
966 if (unlikely(!mem
)) {
974 progress
= try_to_free_mem_cgroup_pages(mem
, gfp_mask
);
975 progress
+= res_counter_check_under_limit(&mem
->res
);
976 } while (!progress
&& --retry
);
984 static int mem_cgroup_resize_limit(struct mem_cgroup
*memcg
,
985 unsigned long long val
)
988 int retry_count
= MEM_CGROUP_RECLAIM_RETRIES
;
992 while (res_counter_set_limit(&memcg
->res
, val
)) {
993 if (signal_pending(current
)) {
1001 progress
= try_to_free_mem_cgroup_pages(memcg
,
1002 GFP_HIGHUSER_MOVABLE
);
1011 * This routine traverse page_cgroup in given list and drop them all.
1012 * *And* this routine doesn't reclaim page itself, just removes page_cgroup.
1014 static int mem_cgroup_force_empty_list(struct mem_cgroup
*mem
,
1015 struct mem_cgroup_per_zone
*mz
,
1018 struct page_cgroup
*pc
, *busy
;
1019 unsigned long flags
;
1021 struct list_head
*list
;
1024 list
= &mz
->lists
[lru
];
1026 loop
= MEM_CGROUP_ZSTAT(mz
, lru
);
1027 /* give some margin against EBUSY etc...*/
1032 spin_lock_irqsave(&mz
->lru_lock
, flags
);
1033 if (list_empty(list
)) {
1034 spin_unlock_irqrestore(&mz
->lru_lock
, flags
);
1037 pc
= list_entry(list
->prev
, struct page_cgroup
, lru
);
1039 list_move(&pc
->lru
, list
);
1041 spin_unlock_irqrestore(&mz
->lru_lock
, flags
);
1044 spin_unlock_irqrestore(&mz
->lru_lock
, flags
);
1046 ret
= mem_cgroup_move_parent(pc
, mem
, GFP_HIGHUSER_MOVABLE
);
1050 if (ret
== -EBUSY
|| ret
== -EINVAL
) {
1051 /* found lock contention or "pc" is obsolete. */
1057 if (!ret
&& !list_empty(list
))
1063 * make mem_cgroup's charge to be 0 if there is no task.
1064 * This enables deleting this mem_cgroup.
1066 static int mem_cgroup_force_empty(struct mem_cgroup
*mem
)
1069 int node
, zid
, shrink
;
1070 int nr_retries
= MEM_CGROUP_RECLAIM_RETRIES
;
1076 while (mem
->res
.usage
> 0) {
1078 if (atomic_read(&mem
->css
.cgroup
->count
) > 0)
1081 /* This is for making all *used* pages to be on LRU. */
1082 lru_add_drain_all();
1084 for_each_node_state(node
, N_POSSIBLE
) {
1085 for (zid
= 0; !ret
&& zid
< MAX_NR_ZONES
; zid
++) {
1086 struct mem_cgroup_per_zone
*mz
;
1088 mz
= mem_cgroup_zoneinfo(mem
, node
, zid
);
1090 ret
= mem_cgroup_force_empty_list(mem
,
1099 /* it seems parent cgroup doesn't have enough mem */
1110 /* returns EBUSY if we come here twice. */
1115 /* try to free all pages in this cgroup */
1117 while (nr_retries
&& mem
->res
.usage
> 0) {
1119 progress
= try_to_free_mem_cgroup_pages(mem
,
1120 GFP_HIGHUSER_MOVABLE
);
1125 /* try move_account...there may be some *locked* pages. */
1132 static u64
mem_cgroup_read(struct cgroup
*cont
, struct cftype
*cft
)
1134 return res_counter_read_u64(&mem_cgroup_from_cont(cont
)->res
,
1138 * The user of this function is...
1141 static int mem_cgroup_write(struct cgroup
*cont
, struct cftype
*cft
,
1144 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cont
);
1145 unsigned long long val
;
1148 switch (cft
->private) {
1150 /* This function does all necessary parse...reuse it */
1151 ret
= res_counter_memparse_write_strategy(buffer
, &val
);
1153 ret
= mem_cgroup_resize_limit(memcg
, val
);
1156 ret
= -EINVAL
; /* should be BUG() ? */
1162 static int mem_cgroup_reset(struct cgroup
*cont
, unsigned int event
)
1164 struct mem_cgroup
*mem
;
1166 mem
= mem_cgroup_from_cont(cont
);
1169 res_counter_reset_max(&mem
->res
);
1172 res_counter_reset_failcnt(&mem
->res
);
1178 static const struct mem_cgroup_stat_desc
{
1181 } mem_cgroup_stat_desc
[] = {
1182 [MEM_CGROUP_STAT_CACHE
] = { "cache", PAGE_SIZE
, },
1183 [MEM_CGROUP_STAT_RSS
] = { "rss", PAGE_SIZE
, },
1184 [MEM_CGROUP_STAT_PGPGIN_COUNT
] = {"pgpgin", 1, },
1185 [MEM_CGROUP_STAT_PGPGOUT_COUNT
] = {"pgpgout", 1, },
1188 static int mem_control_stat_show(struct cgroup
*cont
, struct cftype
*cft
,
1189 struct cgroup_map_cb
*cb
)
1191 struct mem_cgroup
*mem_cont
= mem_cgroup_from_cont(cont
);
1192 struct mem_cgroup_stat
*stat
= &mem_cont
->stat
;
1195 for (i
= 0; i
< ARRAY_SIZE(stat
->cpustat
[0].count
); i
++) {
1198 val
= mem_cgroup_read_stat(stat
, i
);
1199 val
*= mem_cgroup_stat_desc
[i
].unit
;
1200 cb
->fill(cb
, mem_cgroup_stat_desc
[i
].msg
, val
);
1202 /* showing # of active pages */
1204 unsigned long active_anon
, inactive_anon
;
1205 unsigned long active_file
, inactive_file
;
1206 unsigned long unevictable
;
1208 inactive_anon
= mem_cgroup_get_all_zonestat(mem_cont
,
1210 active_anon
= mem_cgroup_get_all_zonestat(mem_cont
,
1212 inactive_file
= mem_cgroup_get_all_zonestat(mem_cont
,
1214 active_file
= mem_cgroup_get_all_zonestat(mem_cont
,
1216 unevictable
= mem_cgroup_get_all_zonestat(mem_cont
,
1219 cb
->fill(cb
, "active_anon", (active_anon
) * PAGE_SIZE
);
1220 cb
->fill(cb
, "inactive_anon", (inactive_anon
) * PAGE_SIZE
);
1221 cb
->fill(cb
, "active_file", (active_file
) * PAGE_SIZE
);
1222 cb
->fill(cb
, "inactive_file", (inactive_file
) * PAGE_SIZE
);
1223 cb
->fill(cb
, "unevictable", unevictable
* PAGE_SIZE
);
1229 static struct cftype mem_cgroup_files
[] = {
1231 .name
= "usage_in_bytes",
1232 .private = RES_USAGE
,
1233 .read_u64
= mem_cgroup_read
,
1236 .name
= "max_usage_in_bytes",
1237 .private = RES_MAX_USAGE
,
1238 .trigger
= mem_cgroup_reset
,
1239 .read_u64
= mem_cgroup_read
,
1242 .name
= "limit_in_bytes",
1243 .private = RES_LIMIT
,
1244 .write_string
= mem_cgroup_write
,
1245 .read_u64
= mem_cgroup_read
,
1249 .private = RES_FAILCNT
,
1250 .trigger
= mem_cgroup_reset
,
1251 .read_u64
= mem_cgroup_read
,
1255 .read_map
= mem_control_stat_show
,
1259 static int alloc_mem_cgroup_per_zone_info(struct mem_cgroup
*mem
, int node
)
1261 struct mem_cgroup_per_node
*pn
;
1262 struct mem_cgroup_per_zone
*mz
;
1264 int zone
, tmp
= node
;
1266 * This routine is called against possible nodes.
1267 * But it's BUG to call kmalloc() against offline node.
1269 * TODO: this routine can waste much memory for nodes which will
1270 * never be onlined. It's better to use memory hotplug callback
1273 if (!node_state(node
, N_NORMAL_MEMORY
))
1275 pn
= kmalloc_node(sizeof(*pn
), GFP_KERNEL
, tmp
);
1279 mem
->info
.nodeinfo
[node
] = pn
;
1280 memset(pn
, 0, sizeof(*pn
));
1282 for (zone
= 0; zone
< MAX_NR_ZONES
; zone
++) {
1283 mz
= &pn
->zoneinfo
[zone
];
1284 spin_lock_init(&mz
->lru_lock
);
1286 INIT_LIST_HEAD(&mz
->lists
[l
]);
1291 static void free_mem_cgroup_per_zone_info(struct mem_cgroup
*mem
, int node
)
1293 kfree(mem
->info
.nodeinfo
[node
]);
1296 static struct mem_cgroup
*mem_cgroup_alloc(void)
1298 struct mem_cgroup
*mem
;
1300 if (sizeof(*mem
) < PAGE_SIZE
)
1301 mem
= kmalloc(sizeof(*mem
), GFP_KERNEL
);
1303 mem
= vmalloc(sizeof(*mem
));
1306 memset(mem
, 0, sizeof(*mem
));
1310 static void mem_cgroup_free(struct mem_cgroup
*mem
)
1312 if (sizeof(*mem
) < PAGE_SIZE
)
1319 static struct cgroup_subsys_state
*
1320 mem_cgroup_create(struct cgroup_subsys
*ss
, struct cgroup
*cont
)
1322 struct mem_cgroup
*mem
;
1325 if (unlikely((cont
->parent
) == NULL
)) {
1326 mem
= &init_mem_cgroup
;
1328 mem
= mem_cgroup_alloc();
1330 return ERR_PTR(-ENOMEM
);
1333 res_counter_init(&mem
->res
);
1335 for_each_node_state(node
, N_POSSIBLE
)
1336 if (alloc_mem_cgroup_per_zone_info(mem
, node
))
1341 for_each_node_state(node
, N_POSSIBLE
)
1342 free_mem_cgroup_per_zone_info(mem
, node
);
1343 if (cont
->parent
!= NULL
)
1344 mem_cgroup_free(mem
);
1345 return ERR_PTR(-ENOMEM
);
1348 static void mem_cgroup_pre_destroy(struct cgroup_subsys
*ss
,
1349 struct cgroup
*cont
)
1351 struct mem_cgroup
*mem
= mem_cgroup_from_cont(cont
);
1352 mem_cgroup_force_empty(mem
);
1355 static void mem_cgroup_destroy(struct cgroup_subsys
*ss
,
1356 struct cgroup
*cont
)
1359 struct mem_cgroup
*mem
= mem_cgroup_from_cont(cont
);
1361 for_each_node_state(node
, N_POSSIBLE
)
1362 free_mem_cgroup_per_zone_info(mem
, node
);
1364 mem_cgroup_free(mem_cgroup_from_cont(cont
));
1367 static int mem_cgroup_populate(struct cgroup_subsys
*ss
,
1368 struct cgroup
*cont
)
1370 return cgroup_add_files(cont
, ss
, mem_cgroup_files
,
1371 ARRAY_SIZE(mem_cgroup_files
));
1374 static void mem_cgroup_move_task(struct cgroup_subsys
*ss
,
1375 struct cgroup
*cont
,
1376 struct cgroup
*old_cont
,
1377 struct task_struct
*p
)
1379 struct mm_struct
*mm
;
1380 struct mem_cgroup
*mem
, *old_mem
;
1382 mm
= get_task_mm(p
);
1386 mem
= mem_cgroup_from_cont(cont
);
1387 old_mem
= mem_cgroup_from_cont(old_cont
);
1390 * Only thread group leaders are allowed to migrate, the mm_struct is
1391 * in effect owned by the leader
1393 if (!thread_group_leader(p
))
1400 struct cgroup_subsys mem_cgroup_subsys
= {
1402 .subsys_id
= mem_cgroup_subsys_id
,
1403 .create
= mem_cgroup_create
,
1404 .pre_destroy
= mem_cgroup_pre_destroy
,
1405 .destroy
= mem_cgroup_destroy
,
1406 .populate
= mem_cgroup_populate
,
1407 .attach
= mem_cgroup_move_task
,