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>
37 #include <asm/uaccess.h>
39 struct cgroup_subsys mem_cgroup_subsys __read_mostly
;
40 static struct kmem_cache
*page_cgroup_cache __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 void __mem_cgroup_stat_add_safe(struct mem_cgroup_stat
*stat
,
70 enum mem_cgroup_stat_index idx
, int val
)
72 int cpu
= smp_processor_id();
73 stat
->cpustat
[cpu
].count
[idx
] += val
;
76 static s64
mem_cgroup_read_stat(struct mem_cgroup_stat
*stat
,
77 enum mem_cgroup_stat_index idx
)
81 for_each_possible_cpu(cpu
)
82 ret
+= stat
->cpustat
[cpu
].count
[idx
];
87 * per-zone information in memory controller.
89 struct mem_cgroup_per_zone
{
91 * spin_lock to protect the per cgroup LRU
94 struct list_head lists
[NR_LRU_LISTS
];
95 unsigned long count
[NR_LRU_LISTS
];
97 /* Macro for accessing counter */
98 #define MEM_CGROUP_ZSTAT(mz, idx) ((mz)->count[(idx)])
100 struct mem_cgroup_per_node
{
101 struct mem_cgroup_per_zone zoneinfo
[MAX_NR_ZONES
];
104 struct mem_cgroup_lru_info
{
105 struct mem_cgroup_per_node
*nodeinfo
[MAX_NUMNODES
];
109 * The memory controller data structure. The memory controller controls both
110 * page cache and RSS per cgroup. We would eventually like to provide
111 * statistics based on the statistics developed by Rik Van Riel for clock-pro,
112 * to help the administrator determine what knobs to tune.
114 * TODO: Add a water mark for the memory controller. Reclaim will begin when
115 * we hit the water mark. May be even add a low water mark, such that
116 * no reclaim occurs from a cgroup at it's low water mark, this is
117 * a feature that will be implemented much later in the future.
120 struct cgroup_subsys_state css
;
122 * the counter to account for memory usage
124 struct res_counter res
;
126 * Per cgroup active and inactive list, similar to the
127 * per zone LRU lists.
129 struct mem_cgroup_lru_info info
;
131 int prev_priority
; /* for recording reclaim priority */
135 struct mem_cgroup_stat stat
;
137 static struct mem_cgroup init_mem_cgroup
;
140 * We use the lower bit of the page->page_cgroup pointer as a bit spin
141 * lock. We need to ensure that page->page_cgroup is at least two
142 * byte aligned (based on comments from Nick Piggin). But since
143 * bit_spin_lock doesn't actually set that lock bit in a non-debug
144 * uniprocessor kernel, we should avoid setting it here too.
146 #define PAGE_CGROUP_LOCK_BIT 0x0
147 #if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK)
148 #define PAGE_CGROUP_LOCK (1 << PAGE_CGROUP_LOCK_BIT)
150 #define PAGE_CGROUP_LOCK 0x0
154 * A page_cgroup page is associated with every page descriptor. The
155 * page_cgroup helps us identify information about the cgroup
158 struct list_head lru
; /* per cgroup LRU list */
160 struct mem_cgroup
*mem_cgroup
;
163 #define PAGE_CGROUP_FLAG_CACHE (0x1) /* charged as cache */
164 #define PAGE_CGROUP_FLAG_ACTIVE (0x2) /* page is active in this cgroup */
165 #define PAGE_CGROUP_FLAG_FILE (0x4) /* page is file system backed */
166 #define PAGE_CGROUP_FLAG_UNEVICTABLE (0x8) /* page is unevictableable */
168 static int page_cgroup_nid(struct page_cgroup
*pc
)
170 return page_to_nid(pc
->page
);
173 static enum zone_type
page_cgroup_zid(struct page_cgroup
*pc
)
175 return page_zonenum(pc
->page
);
179 MEM_CGROUP_CHARGE_TYPE_CACHE
= 0,
180 MEM_CGROUP_CHARGE_TYPE_MAPPED
,
181 MEM_CGROUP_CHARGE_TYPE_FORCE
, /* used by force_empty */
182 MEM_CGROUP_CHARGE_TYPE_SHMEM
, /* used by page migration of shmem */
186 * Always modified under lru lock. Then, not necessary to preempt_disable()
188 static void mem_cgroup_charge_statistics(struct mem_cgroup
*mem
, int flags
,
191 int val
= (charge
)? 1 : -1;
192 struct mem_cgroup_stat
*stat
= &mem
->stat
;
194 VM_BUG_ON(!irqs_disabled());
195 if (flags
& PAGE_CGROUP_FLAG_CACHE
)
196 __mem_cgroup_stat_add_safe(stat
, MEM_CGROUP_STAT_CACHE
, val
);
198 __mem_cgroup_stat_add_safe(stat
, MEM_CGROUP_STAT_RSS
, val
);
201 __mem_cgroup_stat_add_safe(stat
,
202 MEM_CGROUP_STAT_PGPGIN_COUNT
, 1);
204 __mem_cgroup_stat_add_safe(stat
,
205 MEM_CGROUP_STAT_PGPGOUT_COUNT
, 1);
208 static struct mem_cgroup_per_zone
*
209 mem_cgroup_zoneinfo(struct mem_cgroup
*mem
, int nid
, int zid
)
211 return &mem
->info
.nodeinfo
[nid
]->zoneinfo
[zid
];
214 static struct mem_cgroup_per_zone
*
215 page_cgroup_zoneinfo(struct page_cgroup
*pc
)
217 struct mem_cgroup
*mem
= pc
->mem_cgroup
;
218 int nid
= page_cgroup_nid(pc
);
219 int zid
= page_cgroup_zid(pc
);
221 return mem_cgroup_zoneinfo(mem
, nid
, zid
);
224 static unsigned long mem_cgroup_get_all_zonestat(struct mem_cgroup
*mem
,
228 struct mem_cgroup_per_zone
*mz
;
231 for_each_online_node(nid
)
232 for (zid
= 0; zid
< MAX_NR_ZONES
; zid
++) {
233 mz
= mem_cgroup_zoneinfo(mem
, nid
, zid
);
234 total
+= MEM_CGROUP_ZSTAT(mz
, idx
);
239 static struct mem_cgroup
*mem_cgroup_from_cont(struct cgroup
*cont
)
241 return container_of(cgroup_subsys_state(cont
,
242 mem_cgroup_subsys_id
), struct mem_cgroup
,
246 struct mem_cgroup
*mem_cgroup_from_task(struct task_struct
*p
)
249 * mm_update_next_owner() may clear mm->owner to NULL
250 * if it races with swapoff, page migration, etc.
251 * So this can be called with p == NULL.
256 return container_of(task_subsys_state(p
, mem_cgroup_subsys_id
),
257 struct mem_cgroup
, css
);
260 static inline int page_cgroup_locked(struct page
*page
)
262 return bit_spin_is_locked(PAGE_CGROUP_LOCK_BIT
, &page
->page_cgroup
);
265 static void page_assign_page_cgroup(struct page
*page
, struct page_cgroup
*pc
)
267 VM_BUG_ON(!page_cgroup_locked(page
));
268 page
->page_cgroup
= ((unsigned long)pc
| PAGE_CGROUP_LOCK
);
271 struct page_cgroup
*page_get_page_cgroup(struct page
*page
)
273 return (struct page_cgroup
*) (page
->page_cgroup
& ~PAGE_CGROUP_LOCK
);
276 static void lock_page_cgroup(struct page
*page
)
278 bit_spin_lock(PAGE_CGROUP_LOCK_BIT
, &page
->page_cgroup
);
281 static int try_lock_page_cgroup(struct page
*page
)
283 return bit_spin_trylock(PAGE_CGROUP_LOCK_BIT
, &page
->page_cgroup
);
286 static void unlock_page_cgroup(struct page
*page
)
288 bit_spin_unlock(PAGE_CGROUP_LOCK_BIT
, &page
->page_cgroup
);
291 static void __mem_cgroup_remove_list(struct mem_cgroup_per_zone
*mz
,
292 struct page_cgroup
*pc
)
296 if (pc
->flags
& PAGE_CGROUP_FLAG_UNEVICTABLE
)
297 lru
= LRU_UNEVICTABLE
;
299 if (pc
->flags
& PAGE_CGROUP_FLAG_ACTIVE
)
301 if (pc
->flags
& PAGE_CGROUP_FLAG_FILE
)
305 MEM_CGROUP_ZSTAT(mz
, lru
) -= 1;
307 mem_cgroup_charge_statistics(pc
->mem_cgroup
, pc
->flags
, false);
311 static void __mem_cgroup_add_list(struct mem_cgroup_per_zone
*mz
,
312 struct page_cgroup
*pc
)
316 if (pc
->flags
& PAGE_CGROUP_FLAG_UNEVICTABLE
)
317 lru
= LRU_UNEVICTABLE
;
319 if (pc
->flags
& PAGE_CGROUP_FLAG_ACTIVE
)
321 if (pc
->flags
& PAGE_CGROUP_FLAG_FILE
)
325 MEM_CGROUP_ZSTAT(mz
, lru
) += 1;
326 list_add(&pc
->lru
, &mz
->lists
[lru
]);
328 mem_cgroup_charge_statistics(pc
->mem_cgroup
, pc
->flags
, true);
331 static void __mem_cgroup_move_lists(struct page_cgroup
*pc
, enum lru_list lru
)
333 struct mem_cgroup_per_zone
*mz
= page_cgroup_zoneinfo(pc
);
334 int active
= pc
->flags
& PAGE_CGROUP_FLAG_ACTIVE
;
335 int file
= pc
->flags
& PAGE_CGROUP_FLAG_FILE
;
336 int unevictable
= pc
->flags
& PAGE_CGROUP_FLAG_UNEVICTABLE
;
337 enum lru_list from
= unevictable
? LRU_UNEVICTABLE
:
338 (LRU_FILE
* !!file
+ !!active
);
343 MEM_CGROUP_ZSTAT(mz
, from
) -= 1;
345 if (is_unevictable_lru(lru
)) {
346 pc
->flags
&= ~PAGE_CGROUP_FLAG_ACTIVE
;
347 pc
->flags
|= PAGE_CGROUP_FLAG_UNEVICTABLE
;
349 if (is_active_lru(lru
))
350 pc
->flags
|= PAGE_CGROUP_FLAG_ACTIVE
;
352 pc
->flags
&= ~PAGE_CGROUP_FLAG_ACTIVE
;
353 pc
->flags
&= ~PAGE_CGROUP_FLAG_UNEVICTABLE
;
356 MEM_CGROUP_ZSTAT(mz
, lru
) += 1;
357 list_move(&pc
->lru
, &mz
->lists
[lru
]);
360 int task_in_mem_cgroup(struct task_struct
*task
, const struct mem_cgroup
*mem
)
365 ret
= task
->mm
&& mm_match_cgroup(task
->mm
, mem
);
371 * This routine assumes that the appropriate zone's lru lock is already held
373 void mem_cgroup_move_lists(struct page
*page
, enum lru_list lru
)
375 struct page_cgroup
*pc
;
376 struct mem_cgroup_per_zone
*mz
;
379 if (mem_cgroup_subsys
.disabled
)
383 * We cannot lock_page_cgroup while holding zone's lru_lock,
384 * because other holders of lock_page_cgroup can be interrupted
385 * with an attempt to rotate_reclaimable_page. But we cannot
386 * safely get to page_cgroup without it, so just try_lock it:
387 * mem_cgroup_isolate_pages allows for page left on wrong list.
389 if (!try_lock_page_cgroup(page
))
392 pc
= page_get_page_cgroup(page
);
394 mz
= page_cgroup_zoneinfo(pc
);
395 spin_lock_irqsave(&mz
->lru_lock
, flags
);
396 __mem_cgroup_move_lists(pc
, lru
);
397 spin_unlock_irqrestore(&mz
->lru_lock
, flags
);
399 unlock_page_cgroup(page
);
403 * Calculate mapped_ratio under memory controller. This will be used in
404 * vmscan.c for deteremining we have to reclaim mapped pages.
406 int mem_cgroup_calc_mapped_ratio(struct mem_cgroup
*mem
)
411 * usage is recorded in bytes. But, here, we assume the number of
412 * physical pages can be represented by "long" on any arch.
414 total
= (long) (mem
->res
.usage
>> PAGE_SHIFT
) + 1L;
415 rss
= (long)mem_cgroup_read_stat(&mem
->stat
, MEM_CGROUP_STAT_RSS
);
416 return (int)((rss
* 100L) / total
);
420 * prev_priority control...this will be used in memory reclaim path.
422 int mem_cgroup_get_reclaim_priority(struct mem_cgroup
*mem
)
424 return mem
->prev_priority
;
427 void mem_cgroup_note_reclaim_priority(struct mem_cgroup
*mem
, int priority
)
429 if (priority
< mem
->prev_priority
)
430 mem
->prev_priority
= priority
;
433 void mem_cgroup_record_reclaim_priority(struct mem_cgroup
*mem
, int priority
)
435 mem
->prev_priority
= priority
;
439 * Calculate # of pages to be scanned in this priority/zone.
442 * priority starts from "DEF_PRIORITY" and decremented in each loop.
443 * (see include/linux/mmzone.h)
446 long mem_cgroup_calc_reclaim(struct mem_cgroup
*mem
, struct zone
*zone
,
447 int priority
, enum lru_list lru
)
450 int nid
= zone
->zone_pgdat
->node_id
;
451 int zid
= zone_idx(zone
);
452 struct mem_cgroup_per_zone
*mz
= mem_cgroup_zoneinfo(mem
, nid
, zid
);
454 nr_pages
= MEM_CGROUP_ZSTAT(mz
, lru
);
456 return (nr_pages
>> priority
);
459 unsigned long mem_cgroup_isolate_pages(unsigned long nr_to_scan
,
460 struct list_head
*dst
,
461 unsigned long *scanned
, int order
,
462 int mode
, struct zone
*z
,
463 struct mem_cgroup
*mem_cont
,
464 int active
, int file
)
466 unsigned long nr_taken
= 0;
470 struct list_head
*src
;
471 struct page_cgroup
*pc
, *tmp
;
472 int nid
= z
->zone_pgdat
->node_id
;
473 int zid
= zone_idx(z
);
474 struct mem_cgroup_per_zone
*mz
;
475 int lru
= LRU_FILE
* !!file
+ !!active
;
478 mz
= mem_cgroup_zoneinfo(mem_cont
, nid
, zid
);
479 src
= &mz
->lists
[lru
];
481 spin_lock(&mz
->lru_lock
);
483 list_for_each_entry_safe_reverse(pc
, tmp
, src
, lru
) {
484 if (scan
>= nr_to_scan
)
488 if (unlikely(!PageLRU(page
)))
492 * TODO: play better with lumpy reclaim, grabbing anything.
494 if (PageUnevictable(page
) ||
495 (PageActive(page
) && !active
) ||
496 (!PageActive(page
) && active
)) {
497 __mem_cgroup_move_lists(pc
, page_lru(page
));
502 list_move(&pc
->lru
, &pc_list
);
504 if (__isolate_lru_page(page
, mode
, file
) == 0) {
505 list_move(&page
->lru
, dst
);
510 list_splice(&pc_list
, src
);
511 spin_unlock(&mz
->lru_lock
);
518 * Charge the memory controller for page usage.
520 * 0 if the charge was successful
521 * < 0 if the cgroup is over its limit
523 static int mem_cgroup_charge_common(struct page
*page
, struct mm_struct
*mm
,
524 gfp_t gfp_mask
, enum charge_type ctype
,
525 struct mem_cgroup
*memcg
)
527 struct mem_cgroup
*mem
;
528 struct page_cgroup
*pc
;
530 unsigned long nr_retries
= MEM_CGROUP_RECLAIM_RETRIES
;
531 struct mem_cgroup_per_zone
*mz
;
533 pc
= kmem_cache_alloc(page_cgroup_cache
, gfp_mask
);
534 if (unlikely(pc
== NULL
))
538 * We always charge the cgroup the mm_struct belongs to.
539 * The mm_struct's mem_cgroup changes on task migration if the
540 * thread group leader migrates. It's possible that mm is not
541 * set, if so charge the init_mm (happens for pagecache usage).
543 if (likely(!memcg
)) {
545 mem
= mem_cgroup_from_task(rcu_dereference(mm
->owner
));
546 if (unlikely(!mem
)) {
548 kmem_cache_free(page_cgroup_cache
, pc
);
552 * For every charge from the cgroup, increment reference count
558 css_get(&memcg
->css
);
561 while (res_counter_charge(&mem
->res
, PAGE_SIZE
)) {
562 if (!(gfp_mask
& __GFP_WAIT
))
565 if (try_to_free_mem_cgroup_pages(mem
, gfp_mask
))
569 * try_to_free_mem_cgroup_pages() might not give us a full
570 * picture of reclaim. Some pages are reclaimed and might be
571 * moved to swap cache or just unmapped from the cgroup.
572 * Check the limit again to see if the reclaim reduced the
573 * current usage of the cgroup before giving up
575 if (res_counter_check_under_limit(&mem
->res
))
579 mem_cgroup_out_of_memory(mem
, gfp_mask
);
584 pc
->mem_cgroup
= mem
;
587 * If a page is accounted as a page cache, insert to inactive list.
588 * If anon, insert to active list.
590 if (ctype
== MEM_CGROUP_CHARGE_TYPE_CACHE
) {
591 pc
->flags
= PAGE_CGROUP_FLAG_CACHE
;
592 if (page_is_file_cache(page
))
593 pc
->flags
|= PAGE_CGROUP_FLAG_FILE
;
595 pc
->flags
|= PAGE_CGROUP_FLAG_ACTIVE
;
596 } else if (ctype
== MEM_CGROUP_CHARGE_TYPE_MAPPED
)
597 pc
->flags
= PAGE_CGROUP_FLAG_ACTIVE
;
598 else /* MEM_CGROUP_CHARGE_TYPE_SHMEM */
599 pc
->flags
= PAGE_CGROUP_FLAG_CACHE
| PAGE_CGROUP_FLAG_ACTIVE
;
601 lock_page_cgroup(page
);
602 if (unlikely(page_get_page_cgroup(page
))) {
603 unlock_page_cgroup(page
);
604 res_counter_uncharge(&mem
->res
, PAGE_SIZE
);
606 kmem_cache_free(page_cgroup_cache
, pc
);
609 page_assign_page_cgroup(page
, pc
);
611 mz
= page_cgroup_zoneinfo(pc
);
612 spin_lock_irqsave(&mz
->lru_lock
, flags
);
613 __mem_cgroup_add_list(mz
, pc
);
614 spin_unlock_irqrestore(&mz
->lru_lock
, flags
);
616 unlock_page_cgroup(page
);
621 kmem_cache_free(page_cgroup_cache
, pc
);
626 int mem_cgroup_charge(struct page
*page
, struct mm_struct
*mm
, gfp_t gfp_mask
)
628 if (mem_cgroup_subsys
.disabled
)
632 * If already mapped, we don't have to account.
633 * If page cache, page->mapping has address_space.
634 * But page->mapping may have out-of-use anon_vma pointer,
635 * detecit it by PageAnon() check. newly-mapped-anon's page->mapping
638 if (page_mapped(page
) || (page
->mapping
&& !PageAnon(page
)))
642 return mem_cgroup_charge_common(page
, mm
, gfp_mask
,
643 MEM_CGROUP_CHARGE_TYPE_MAPPED
, NULL
);
646 int mem_cgroup_cache_charge(struct page
*page
, struct mm_struct
*mm
,
649 if (mem_cgroup_subsys
.disabled
)
653 * Corner case handling. This is called from add_to_page_cache()
654 * in usual. But some FS (shmem) precharges this page before calling it
655 * and call add_to_page_cache() with GFP_NOWAIT.
657 * For GFP_NOWAIT case, the page may be pre-charged before calling
658 * add_to_page_cache(). (See shmem.c) check it here and avoid to call
659 * charge twice. (It works but has to pay a bit larger cost.)
661 if (!(gfp_mask
& __GFP_WAIT
)) {
662 struct page_cgroup
*pc
;
664 lock_page_cgroup(page
);
665 pc
= page_get_page_cgroup(page
);
667 VM_BUG_ON(pc
->page
!= page
);
668 VM_BUG_ON(!pc
->mem_cgroup
);
669 unlock_page_cgroup(page
);
672 unlock_page_cgroup(page
);
678 return mem_cgroup_charge_common(page
, mm
, gfp_mask
,
679 MEM_CGROUP_CHARGE_TYPE_CACHE
, NULL
);
683 * uncharge if !page_mapped(page)
686 __mem_cgroup_uncharge_common(struct page
*page
, enum charge_type ctype
)
688 struct page_cgroup
*pc
;
689 struct mem_cgroup
*mem
;
690 struct mem_cgroup_per_zone
*mz
;
693 if (mem_cgroup_subsys
.disabled
)
697 * Check if our page_cgroup is valid
699 lock_page_cgroup(page
);
700 pc
= page_get_page_cgroup(page
);
704 VM_BUG_ON(pc
->page
!= page
);
706 if ((ctype
== MEM_CGROUP_CHARGE_TYPE_MAPPED
)
707 && ((pc
->flags
& PAGE_CGROUP_FLAG_CACHE
)
708 || page_mapped(page
)))
711 mz
= page_cgroup_zoneinfo(pc
);
712 spin_lock_irqsave(&mz
->lru_lock
, flags
);
713 __mem_cgroup_remove_list(mz
, pc
);
714 spin_unlock_irqrestore(&mz
->lru_lock
, flags
);
716 page_assign_page_cgroup(page
, NULL
);
717 unlock_page_cgroup(page
);
719 mem
= pc
->mem_cgroup
;
720 res_counter_uncharge(&mem
->res
, PAGE_SIZE
);
723 kmem_cache_free(page_cgroup_cache
, pc
);
726 unlock_page_cgroup(page
);
729 void mem_cgroup_uncharge_page(struct page
*page
)
731 __mem_cgroup_uncharge_common(page
, MEM_CGROUP_CHARGE_TYPE_MAPPED
);
734 void mem_cgroup_uncharge_cache_page(struct page
*page
)
736 VM_BUG_ON(page_mapped(page
));
737 __mem_cgroup_uncharge_common(page
, MEM_CGROUP_CHARGE_TYPE_CACHE
);
741 * Before starting migration, account against new page.
743 int mem_cgroup_prepare_migration(struct page
*page
, struct page
*newpage
)
745 struct page_cgroup
*pc
;
746 struct mem_cgroup
*mem
= NULL
;
747 enum charge_type ctype
= MEM_CGROUP_CHARGE_TYPE_MAPPED
;
750 if (mem_cgroup_subsys
.disabled
)
753 lock_page_cgroup(page
);
754 pc
= page_get_page_cgroup(page
);
756 mem
= pc
->mem_cgroup
;
758 if (pc
->flags
& PAGE_CGROUP_FLAG_CACHE
) {
759 if (page_is_file_cache(page
))
760 ctype
= MEM_CGROUP_CHARGE_TYPE_CACHE
;
762 ctype
= MEM_CGROUP_CHARGE_TYPE_SHMEM
;
765 unlock_page_cgroup(page
);
767 ret
= mem_cgroup_charge_common(newpage
, NULL
, GFP_KERNEL
,
774 /* remove redundant charge if migration failed*/
775 void mem_cgroup_end_migration(struct page
*newpage
)
778 * At success, page->mapping is not NULL.
779 * special rollback care is necessary when
780 * 1. at migration failure. (newpage->mapping is cleared in this case)
781 * 2. the newpage was moved but not remapped again because the task
782 * exits and the newpage is obsolete. In this case, the new page
783 * may be a swapcache. So, we just call mem_cgroup_uncharge_page()
784 * always for avoiding mess. The page_cgroup will be removed if
785 * unnecessary. File cache pages is still on radix-tree. Don't
788 if (!newpage
->mapping
)
789 __mem_cgroup_uncharge_common(newpage
,
790 MEM_CGROUP_CHARGE_TYPE_FORCE
);
791 else if (PageAnon(newpage
))
792 mem_cgroup_uncharge_page(newpage
);
796 * A call to try to shrink memory usage under specified resource controller.
797 * This is typically used for page reclaiming for shmem for reducing side
798 * effect of page allocation from shmem, which is used by some mem_cgroup.
800 int mem_cgroup_shrink_usage(struct mm_struct
*mm
, gfp_t gfp_mask
)
802 struct mem_cgroup
*mem
;
804 int retry
= MEM_CGROUP_RECLAIM_RETRIES
;
806 if (mem_cgroup_subsys
.disabled
)
812 mem
= mem_cgroup_from_task(rcu_dereference(mm
->owner
));
813 if (unlikely(!mem
)) {
821 progress
= try_to_free_mem_cgroup_pages(mem
, gfp_mask
);
822 progress
+= res_counter_check_under_limit(&mem
->res
);
823 } while (!progress
&& --retry
);
831 int mem_cgroup_resize_limit(struct mem_cgroup
*memcg
, unsigned long long val
)
834 int retry_count
= MEM_CGROUP_RECLAIM_RETRIES
;
838 while (res_counter_set_limit(&memcg
->res
, val
)) {
839 if (signal_pending(current
)) {
847 progress
= try_to_free_mem_cgroup_pages(memcg
, GFP_KERNEL
);
856 * This routine traverse page_cgroup in given list and drop them all.
857 * *And* this routine doesn't reclaim page itself, just removes page_cgroup.
859 #define FORCE_UNCHARGE_BATCH (128)
860 static void mem_cgroup_force_empty_list(struct mem_cgroup
*mem
,
861 struct mem_cgroup_per_zone
*mz
,
864 struct page_cgroup
*pc
;
866 int count
= FORCE_UNCHARGE_BATCH
;
868 struct list_head
*list
;
870 list
= &mz
->lists
[lru
];
872 spin_lock_irqsave(&mz
->lru_lock
, flags
);
873 while (!list_empty(list
)) {
874 pc
= list_entry(list
->prev
, struct page_cgroup
, lru
);
877 spin_unlock_irqrestore(&mz
->lru_lock
, flags
);
879 * Check if this page is on LRU. !LRU page can be found
880 * if it's under page migration.
883 __mem_cgroup_uncharge_common(page
,
884 MEM_CGROUP_CHARGE_TYPE_FORCE
);
887 count
= FORCE_UNCHARGE_BATCH
;
892 spin_lock_irqsave(&mz
->lru_lock
, flags
);
894 spin_unlock_irqrestore(&mz
->lru_lock
, flags
);
898 * make mem_cgroup's charge to be 0 if there is no task.
899 * This enables deleting this mem_cgroup.
901 static int mem_cgroup_force_empty(struct mem_cgroup
*mem
)
908 * page reclaim code (kswapd etc..) will move pages between
909 * active_list <-> inactive_list while we don't take a lock.
910 * So, we have to do loop here until all lists are empty.
912 while (mem
->res
.usage
> 0) {
913 if (atomic_read(&mem
->css
.cgroup
->count
) > 0)
915 for_each_node_state(node
, N_POSSIBLE
)
916 for (zid
= 0; zid
< MAX_NR_ZONES
; zid
++) {
917 struct mem_cgroup_per_zone
*mz
;
919 mz
= mem_cgroup_zoneinfo(mem
, node
, zid
);
921 mem_cgroup_force_empty_list(mem
, mz
, l
);
930 static u64
mem_cgroup_read(struct cgroup
*cont
, struct cftype
*cft
)
932 return res_counter_read_u64(&mem_cgroup_from_cont(cont
)->res
,
936 * The user of this function is...
939 static int mem_cgroup_write(struct cgroup
*cont
, struct cftype
*cft
,
942 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cont
);
943 unsigned long long val
;
946 switch (cft
->private) {
948 /* This function does all necessary parse...reuse it */
949 ret
= res_counter_memparse_write_strategy(buffer
, &val
);
951 ret
= mem_cgroup_resize_limit(memcg
, val
);
954 ret
= -EINVAL
; /* should be BUG() ? */
960 static int mem_cgroup_reset(struct cgroup
*cont
, unsigned int event
)
962 struct mem_cgroup
*mem
;
964 mem
= mem_cgroup_from_cont(cont
);
967 res_counter_reset_max(&mem
->res
);
970 res_counter_reset_failcnt(&mem
->res
);
976 static int mem_force_empty_write(struct cgroup
*cont
, unsigned int event
)
978 return mem_cgroup_force_empty(mem_cgroup_from_cont(cont
));
981 static const struct mem_cgroup_stat_desc
{
984 } mem_cgroup_stat_desc
[] = {
985 [MEM_CGROUP_STAT_CACHE
] = { "cache", PAGE_SIZE
, },
986 [MEM_CGROUP_STAT_RSS
] = { "rss", PAGE_SIZE
, },
987 [MEM_CGROUP_STAT_PGPGIN_COUNT
] = {"pgpgin", 1, },
988 [MEM_CGROUP_STAT_PGPGOUT_COUNT
] = {"pgpgout", 1, },
991 static int mem_control_stat_show(struct cgroup
*cont
, struct cftype
*cft
,
992 struct cgroup_map_cb
*cb
)
994 struct mem_cgroup
*mem_cont
= mem_cgroup_from_cont(cont
);
995 struct mem_cgroup_stat
*stat
= &mem_cont
->stat
;
998 for (i
= 0; i
< ARRAY_SIZE(stat
->cpustat
[0].count
); i
++) {
1001 val
= mem_cgroup_read_stat(stat
, i
);
1002 val
*= mem_cgroup_stat_desc
[i
].unit
;
1003 cb
->fill(cb
, mem_cgroup_stat_desc
[i
].msg
, val
);
1005 /* showing # of active pages */
1007 unsigned long active_anon
, inactive_anon
;
1008 unsigned long active_file
, inactive_file
;
1009 unsigned long unevictable
;
1011 inactive_anon
= mem_cgroup_get_all_zonestat(mem_cont
,
1013 active_anon
= mem_cgroup_get_all_zonestat(mem_cont
,
1015 inactive_file
= mem_cgroup_get_all_zonestat(mem_cont
,
1017 active_file
= mem_cgroup_get_all_zonestat(mem_cont
,
1019 unevictable
= mem_cgroup_get_all_zonestat(mem_cont
,
1022 cb
->fill(cb
, "active_anon", (active_anon
) * PAGE_SIZE
);
1023 cb
->fill(cb
, "inactive_anon", (inactive_anon
) * PAGE_SIZE
);
1024 cb
->fill(cb
, "active_file", (active_file
) * PAGE_SIZE
);
1025 cb
->fill(cb
, "inactive_file", (inactive_file
) * PAGE_SIZE
);
1026 cb
->fill(cb
, "unevictable", unevictable
* PAGE_SIZE
);
1032 static struct cftype mem_cgroup_files
[] = {
1034 .name
= "usage_in_bytes",
1035 .private = RES_USAGE
,
1036 .read_u64
= mem_cgroup_read
,
1039 .name
= "max_usage_in_bytes",
1040 .private = RES_MAX_USAGE
,
1041 .trigger
= mem_cgroup_reset
,
1042 .read_u64
= mem_cgroup_read
,
1045 .name
= "limit_in_bytes",
1046 .private = RES_LIMIT
,
1047 .write_string
= mem_cgroup_write
,
1048 .read_u64
= mem_cgroup_read
,
1052 .private = RES_FAILCNT
,
1053 .trigger
= mem_cgroup_reset
,
1054 .read_u64
= mem_cgroup_read
,
1057 .name
= "force_empty",
1058 .trigger
= mem_force_empty_write
,
1062 .read_map
= mem_control_stat_show
,
1066 static int alloc_mem_cgroup_per_zone_info(struct mem_cgroup
*mem
, int node
)
1068 struct mem_cgroup_per_node
*pn
;
1069 struct mem_cgroup_per_zone
*mz
;
1071 int zone
, tmp
= node
;
1073 * This routine is called against possible nodes.
1074 * But it's BUG to call kmalloc() against offline node.
1076 * TODO: this routine can waste much memory for nodes which will
1077 * never be onlined. It's better to use memory hotplug callback
1080 if (!node_state(node
, N_NORMAL_MEMORY
))
1082 pn
= kmalloc_node(sizeof(*pn
), GFP_KERNEL
, tmp
);
1086 mem
->info
.nodeinfo
[node
] = pn
;
1087 memset(pn
, 0, sizeof(*pn
));
1089 for (zone
= 0; zone
< MAX_NR_ZONES
; zone
++) {
1090 mz
= &pn
->zoneinfo
[zone
];
1091 spin_lock_init(&mz
->lru_lock
);
1093 INIT_LIST_HEAD(&mz
->lists
[l
]);
1098 static void free_mem_cgroup_per_zone_info(struct mem_cgroup
*mem
, int node
)
1100 kfree(mem
->info
.nodeinfo
[node
]);
1103 static struct mem_cgroup
*mem_cgroup_alloc(void)
1105 struct mem_cgroup
*mem
;
1107 if (sizeof(*mem
) < PAGE_SIZE
)
1108 mem
= kmalloc(sizeof(*mem
), GFP_KERNEL
);
1110 mem
= vmalloc(sizeof(*mem
));
1113 memset(mem
, 0, sizeof(*mem
));
1117 static void mem_cgroup_free(struct mem_cgroup
*mem
)
1119 if (sizeof(*mem
) < PAGE_SIZE
)
1126 static struct cgroup_subsys_state
*
1127 mem_cgroup_create(struct cgroup_subsys
*ss
, struct cgroup
*cont
)
1129 struct mem_cgroup
*mem
;
1132 if (unlikely((cont
->parent
) == NULL
)) {
1133 mem
= &init_mem_cgroup
;
1134 page_cgroup_cache
= KMEM_CACHE(page_cgroup
, SLAB_PANIC
);
1136 mem
= mem_cgroup_alloc();
1138 return ERR_PTR(-ENOMEM
);
1141 res_counter_init(&mem
->res
);
1143 for_each_node_state(node
, N_POSSIBLE
)
1144 if (alloc_mem_cgroup_per_zone_info(mem
, node
))
1149 for_each_node_state(node
, N_POSSIBLE
)
1150 free_mem_cgroup_per_zone_info(mem
, node
);
1151 if (cont
->parent
!= NULL
)
1152 mem_cgroup_free(mem
);
1153 return ERR_PTR(-ENOMEM
);
1156 static void mem_cgroup_pre_destroy(struct cgroup_subsys
*ss
,
1157 struct cgroup
*cont
)
1159 struct mem_cgroup
*mem
= mem_cgroup_from_cont(cont
);
1160 mem_cgroup_force_empty(mem
);
1163 static void mem_cgroup_destroy(struct cgroup_subsys
*ss
,
1164 struct cgroup
*cont
)
1167 struct mem_cgroup
*mem
= mem_cgroup_from_cont(cont
);
1169 for_each_node_state(node
, N_POSSIBLE
)
1170 free_mem_cgroup_per_zone_info(mem
, node
);
1172 mem_cgroup_free(mem_cgroup_from_cont(cont
));
1175 static int mem_cgroup_populate(struct cgroup_subsys
*ss
,
1176 struct cgroup
*cont
)
1178 return cgroup_add_files(cont
, ss
, mem_cgroup_files
,
1179 ARRAY_SIZE(mem_cgroup_files
));
1182 static void mem_cgroup_move_task(struct cgroup_subsys
*ss
,
1183 struct cgroup
*cont
,
1184 struct cgroup
*old_cont
,
1185 struct task_struct
*p
)
1187 struct mm_struct
*mm
;
1188 struct mem_cgroup
*mem
, *old_mem
;
1190 mm
= get_task_mm(p
);
1194 mem
= mem_cgroup_from_cont(cont
);
1195 old_mem
= mem_cgroup_from_cont(old_cont
);
1198 * Only thread group leaders are allowed to migrate, the mm_struct is
1199 * in effect owned by the leader
1201 if (!thread_group_leader(p
))
1208 struct cgroup_subsys mem_cgroup_subsys
= {
1210 .subsys_id
= mem_cgroup_subsys_id
,
1211 .create
= mem_cgroup_create
,
1212 .pre_destroy
= mem_cgroup_pre_destroy
,
1213 .destroy
= mem_cgroup_destroy
,
1214 .populate
= mem_cgroup_populate
,
1215 .attach
= mem_cgroup_move_task
,