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>
35 #include <asm/uaccess.h>
37 struct cgroup_subsys mem_cgroup_subsys
;
38 static const int MEM_CGROUP_RECLAIM_RETRIES
= 5;
39 static struct kmem_cache
*page_cgroup_cache
;
42 * Statistics for memory cgroup.
44 enum mem_cgroup_stat_index
{
46 * For MEM_CONTAINER_TYPE_ALL, usage = pagecache + rss.
48 MEM_CGROUP_STAT_CACHE
, /* # of pages charged as cache */
49 MEM_CGROUP_STAT_RSS
, /* # of pages charged as rss */
51 MEM_CGROUP_STAT_NSTATS
,
54 struct mem_cgroup_stat_cpu
{
55 s64 count
[MEM_CGROUP_STAT_NSTATS
];
56 } ____cacheline_aligned_in_smp
;
58 struct mem_cgroup_stat
{
59 struct mem_cgroup_stat_cpu cpustat
[NR_CPUS
];
63 * For accounting under irq disable, no need for increment preempt count.
65 static void __mem_cgroup_stat_add_safe(struct mem_cgroup_stat
*stat
,
66 enum mem_cgroup_stat_index idx
, int val
)
68 int cpu
= smp_processor_id();
69 stat
->cpustat
[cpu
].count
[idx
] += val
;
72 static s64
mem_cgroup_read_stat(struct mem_cgroup_stat
*stat
,
73 enum mem_cgroup_stat_index idx
)
77 for_each_possible_cpu(cpu
)
78 ret
+= stat
->cpustat
[cpu
].count
[idx
];
83 * per-zone information in memory controller.
86 enum mem_cgroup_zstat_index
{
87 MEM_CGROUP_ZSTAT_ACTIVE
,
88 MEM_CGROUP_ZSTAT_INACTIVE
,
93 struct mem_cgroup_per_zone
{
95 * spin_lock to protect the per cgroup LRU
98 struct list_head active_list
;
99 struct list_head inactive_list
;
100 unsigned long count
[NR_MEM_CGROUP_ZSTAT
];
102 /* Macro for accessing counter */
103 #define MEM_CGROUP_ZSTAT(mz, idx) ((mz)->count[(idx)])
105 struct mem_cgroup_per_node
{
106 struct mem_cgroup_per_zone zoneinfo
[MAX_NR_ZONES
];
109 struct mem_cgroup_lru_info
{
110 struct mem_cgroup_per_node
*nodeinfo
[MAX_NUMNODES
];
114 * The memory controller data structure. The memory controller controls both
115 * page cache and RSS per cgroup. We would eventually like to provide
116 * statistics based on the statistics developed by Rik Van Riel for clock-pro,
117 * to help the administrator determine what knobs to tune.
119 * TODO: Add a water mark for the memory controller. Reclaim will begin when
120 * we hit the water mark. May be even add a low water mark, such that
121 * no reclaim occurs from a cgroup at it's low water mark, this is
122 * a feature that will be implemented much later in the future.
125 struct cgroup_subsys_state css
;
127 * the counter to account for memory usage
129 struct res_counter res
;
131 * Per cgroup active and inactive list, similar to the
132 * per zone LRU lists.
134 struct mem_cgroup_lru_info info
;
136 int prev_priority
; /* for recording reclaim priority */
140 struct mem_cgroup_stat stat
;
142 static struct mem_cgroup init_mem_cgroup
;
145 * We use the lower bit of the page->page_cgroup pointer as a bit spin
146 * lock. We need to ensure that page->page_cgroup is at least two
147 * byte aligned (based on comments from Nick Piggin). But since
148 * bit_spin_lock doesn't actually set that lock bit in a non-debug
149 * uniprocessor kernel, we should avoid setting it here too.
151 #define PAGE_CGROUP_LOCK_BIT 0x0
152 #if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK)
153 #define PAGE_CGROUP_LOCK (1 << PAGE_CGROUP_LOCK_BIT)
155 #define PAGE_CGROUP_LOCK 0x0
159 * A page_cgroup page is associated with every page descriptor. The
160 * page_cgroup helps us identify information about the cgroup
163 struct list_head lru
; /* per cgroup LRU list */
165 struct mem_cgroup
*mem_cgroup
;
166 int ref_cnt
; /* cached, mapped, migrating */
169 #define PAGE_CGROUP_FLAG_CACHE (0x1) /* charged as cache */
170 #define PAGE_CGROUP_FLAG_ACTIVE (0x2) /* page is active in this cgroup */
172 static int page_cgroup_nid(struct page_cgroup
*pc
)
174 return page_to_nid(pc
->page
);
177 static enum zone_type
page_cgroup_zid(struct page_cgroup
*pc
)
179 return page_zonenum(pc
->page
);
183 MEM_CGROUP_CHARGE_TYPE_CACHE
= 0,
184 MEM_CGROUP_CHARGE_TYPE_MAPPED
,
188 * Always modified under lru lock. Then, not necessary to preempt_disable()
190 static void mem_cgroup_charge_statistics(struct mem_cgroup
*mem
, int flags
,
193 int val
= (charge
)? 1 : -1;
194 struct mem_cgroup_stat
*stat
= &mem
->stat
;
196 VM_BUG_ON(!irqs_disabled());
197 if (flags
& PAGE_CGROUP_FLAG_CACHE
)
198 __mem_cgroup_stat_add_safe(stat
, MEM_CGROUP_STAT_CACHE
, val
);
200 __mem_cgroup_stat_add_safe(stat
, MEM_CGROUP_STAT_RSS
, val
);
203 static struct mem_cgroup_per_zone
*
204 mem_cgroup_zoneinfo(struct mem_cgroup
*mem
, int nid
, int zid
)
206 return &mem
->info
.nodeinfo
[nid
]->zoneinfo
[zid
];
209 static struct mem_cgroup_per_zone
*
210 page_cgroup_zoneinfo(struct page_cgroup
*pc
)
212 struct mem_cgroup
*mem
= pc
->mem_cgroup
;
213 int nid
= page_cgroup_nid(pc
);
214 int zid
= page_cgroup_zid(pc
);
216 return mem_cgroup_zoneinfo(mem
, nid
, zid
);
219 static unsigned long mem_cgroup_get_all_zonestat(struct mem_cgroup
*mem
,
220 enum mem_cgroup_zstat_index idx
)
223 struct mem_cgroup_per_zone
*mz
;
226 for_each_online_node(nid
)
227 for (zid
= 0; zid
< MAX_NR_ZONES
; zid
++) {
228 mz
= mem_cgroup_zoneinfo(mem
, nid
, zid
);
229 total
+= MEM_CGROUP_ZSTAT(mz
, idx
);
234 static struct mem_cgroup
*mem_cgroup_from_cont(struct cgroup
*cont
)
236 return container_of(cgroup_subsys_state(cont
,
237 mem_cgroup_subsys_id
), struct mem_cgroup
,
241 struct mem_cgroup
*mem_cgroup_from_task(struct task_struct
*p
)
243 return container_of(task_subsys_state(p
, mem_cgroup_subsys_id
),
244 struct mem_cgroup
, css
);
247 static inline int page_cgroup_locked(struct page
*page
)
249 return bit_spin_is_locked(PAGE_CGROUP_LOCK_BIT
, &page
->page_cgroup
);
252 static void page_assign_page_cgroup(struct page
*page
, struct page_cgroup
*pc
)
254 VM_BUG_ON(!page_cgroup_locked(page
));
255 page
->page_cgroup
= ((unsigned long)pc
| PAGE_CGROUP_LOCK
);
258 struct page_cgroup
*page_get_page_cgroup(struct page
*page
)
260 return (struct page_cgroup
*) (page
->page_cgroup
& ~PAGE_CGROUP_LOCK
);
263 static void lock_page_cgroup(struct page
*page
)
265 bit_spin_lock(PAGE_CGROUP_LOCK_BIT
, &page
->page_cgroup
);
268 static int try_lock_page_cgroup(struct page
*page
)
270 return bit_spin_trylock(PAGE_CGROUP_LOCK_BIT
, &page
->page_cgroup
);
273 static void unlock_page_cgroup(struct page
*page
)
275 bit_spin_unlock(PAGE_CGROUP_LOCK_BIT
, &page
->page_cgroup
);
278 static void __mem_cgroup_remove_list(struct mem_cgroup_per_zone
*mz
,
279 struct page_cgroup
*pc
)
281 int from
= pc
->flags
& PAGE_CGROUP_FLAG_ACTIVE
;
284 MEM_CGROUP_ZSTAT(mz
, MEM_CGROUP_ZSTAT_ACTIVE
) -= 1;
286 MEM_CGROUP_ZSTAT(mz
, MEM_CGROUP_ZSTAT_INACTIVE
) -= 1;
288 mem_cgroup_charge_statistics(pc
->mem_cgroup
, pc
->flags
, false);
289 list_del_init(&pc
->lru
);
292 static void __mem_cgroup_add_list(struct mem_cgroup_per_zone
*mz
,
293 struct page_cgroup
*pc
)
295 int to
= pc
->flags
& PAGE_CGROUP_FLAG_ACTIVE
;
298 MEM_CGROUP_ZSTAT(mz
, MEM_CGROUP_ZSTAT_INACTIVE
) += 1;
299 list_add(&pc
->lru
, &mz
->inactive_list
);
301 MEM_CGROUP_ZSTAT(mz
, MEM_CGROUP_ZSTAT_ACTIVE
) += 1;
302 list_add(&pc
->lru
, &mz
->active_list
);
304 mem_cgroup_charge_statistics(pc
->mem_cgroup
, pc
->flags
, true);
307 static void __mem_cgroup_move_lists(struct page_cgroup
*pc
, bool active
)
309 int from
= pc
->flags
& PAGE_CGROUP_FLAG_ACTIVE
;
310 struct mem_cgroup_per_zone
*mz
= page_cgroup_zoneinfo(pc
);
313 MEM_CGROUP_ZSTAT(mz
, MEM_CGROUP_ZSTAT_ACTIVE
) -= 1;
315 MEM_CGROUP_ZSTAT(mz
, MEM_CGROUP_ZSTAT_INACTIVE
) -= 1;
318 MEM_CGROUP_ZSTAT(mz
, MEM_CGROUP_ZSTAT_ACTIVE
) += 1;
319 pc
->flags
|= PAGE_CGROUP_FLAG_ACTIVE
;
320 list_move(&pc
->lru
, &mz
->active_list
);
322 MEM_CGROUP_ZSTAT(mz
, MEM_CGROUP_ZSTAT_INACTIVE
) += 1;
323 pc
->flags
&= ~PAGE_CGROUP_FLAG_ACTIVE
;
324 list_move(&pc
->lru
, &mz
->inactive_list
);
328 int task_in_mem_cgroup(struct task_struct
*task
, const struct mem_cgroup
*mem
)
333 ret
= task
->mm
&& mm_match_cgroup(task
->mm
, mem
);
339 * This routine assumes that the appropriate zone's lru lock is already held
341 void mem_cgroup_move_lists(struct page
*page
, bool active
)
343 struct page_cgroup
*pc
;
344 struct mem_cgroup_per_zone
*mz
;
348 * We cannot lock_page_cgroup while holding zone's lru_lock,
349 * because other holders of lock_page_cgroup can be interrupted
350 * with an attempt to rotate_reclaimable_page. But we cannot
351 * safely get to page_cgroup without it, so just try_lock it:
352 * mem_cgroup_isolate_pages allows for page left on wrong list.
354 if (!try_lock_page_cgroup(page
))
357 pc
= page_get_page_cgroup(page
);
359 mz
= page_cgroup_zoneinfo(pc
);
360 spin_lock_irqsave(&mz
->lru_lock
, flags
);
361 __mem_cgroup_move_lists(pc
, active
);
362 spin_unlock_irqrestore(&mz
->lru_lock
, flags
);
364 unlock_page_cgroup(page
);
368 * Calculate mapped_ratio under memory controller. This will be used in
369 * vmscan.c for deteremining we have to reclaim mapped pages.
371 int mem_cgroup_calc_mapped_ratio(struct mem_cgroup
*mem
)
376 * usage is recorded in bytes. But, here, we assume the number of
377 * physical pages can be represented by "long" on any arch.
379 total
= (long) (mem
->res
.usage
>> PAGE_SHIFT
) + 1L;
380 rss
= (long)mem_cgroup_read_stat(&mem
->stat
, MEM_CGROUP_STAT_RSS
);
381 return (int)((rss
* 100L) / total
);
385 * This function is called from vmscan.c. In page reclaiming loop. balance
386 * between active and inactive list is calculated. For memory controller
387 * page reclaiming, we should use using mem_cgroup's imbalance rather than
388 * zone's global lru imbalance.
390 long mem_cgroup_reclaim_imbalance(struct mem_cgroup
*mem
)
392 unsigned long active
, inactive
;
393 /* active and inactive are the number of pages. 'long' is ok.*/
394 active
= mem_cgroup_get_all_zonestat(mem
, MEM_CGROUP_ZSTAT_ACTIVE
);
395 inactive
= mem_cgroup_get_all_zonestat(mem
, MEM_CGROUP_ZSTAT_INACTIVE
);
396 return (long) (active
/ (inactive
+ 1));
400 * prev_priority control...this will be used in memory reclaim path.
402 int mem_cgroup_get_reclaim_priority(struct mem_cgroup
*mem
)
404 return mem
->prev_priority
;
407 void mem_cgroup_note_reclaim_priority(struct mem_cgroup
*mem
, int priority
)
409 if (priority
< mem
->prev_priority
)
410 mem
->prev_priority
= priority
;
413 void mem_cgroup_record_reclaim_priority(struct mem_cgroup
*mem
, int priority
)
415 mem
->prev_priority
= priority
;
419 * Calculate # of pages to be scanned in this priority/zone.
422 * priority starts from "DEF_PRIORITY" and decremented in each loop.
423 * (see include/linux/mmzone.h)
426 long mem_cgroup_calc_reclaim_active(struct mem_cgroup
*mem
,
427 struct zone
*zone
, int priority
)
430 int nid
= zone
->zone_pgdat
->node_id
;
431 int zid
= zone_idx(zone
);
432 struct mem_cgroup_per_zone
*mz
= mem_cgroup_zoneinfo(mem
, nid
, zid
);
434 nr_active
= MEM_CGROUP_ZSTAT(mz
, MEM_CGROUP_ZSTAT_ACTIVE
);
435 return (nr_active
>> priority
);
438 long mem_cgroup_calc_reclaim_inactive(struct mem_cgroup
*mem
,
439 struct zone
*zone
, int priority
)
442 int nid
= zone
->zone_pgdat
->node_id
;
443 int zid
= zone_idx(zone
);
444 struct mem_cgroup_per_zone
*mz
= mem_cgroup_zoneinfo(mem
, nid
, zid
);
446 nr_inactive
= MEM_CGROUP_ZSTAT(mz
, MEM_CGROUP_ZSTAT_INACTIVE
);
447 return (nr_inactive
>> priority
);
450 unsigned long mem_cgroup_isolate_pages(unsigned long nr_to_scan
,
451 struct list_head
*dst
,
452 unsigned long *scanned
, int order
,
453 int mode
, struct zone
*z
,
454 struct mem_cgroup
*mem_cont
,
457 unsigned long nr_taken
= 0;
461 struct list_head
*src
;
462 struct page_cgroup
*pc
, *tmp
;
463 int nid
= z
->zone_pgdat
->node_id
;
464 int zid
= zone_idx(z
);
465 struct mem_cgroup_per_zone
*mz
;
468 mz
= mem_cgroup_zoneinfo(mem_cont
, nid
, zid
);
470 src
= &mz
->active_list
;
472 src
= &mz
->inactive_list
;
475 spin_lock(&mz
->lru_lock
);
477 list_for_each_entry_safe_reverse(pc
, tmp
, src
, lru
) {
478 if (scan
>= nr_to_scan
)
482 if (unlikely(!PageLRU(page
)))
485 if (PageActive(page
) && !active
) {
486 __mem_cgroup_move_lists(pc
, true);
489 if (!PageActive(page
) && active
) {
490 __mem_cgroup_move_lists(pc
, false);
495 list_move(&pc
->lru
, &pc_list
);
497 if (__isolate_lru_page(page
, mode
) == 0) {
498 list_move(&page
->lru
, dst
);
503 list_splice(&pc_list
, src
);
504 spin_unlock(&mz
->lru_lock
);
511 * Charge the memory controller for page usage.
513 * 0 if the charge was successful
514 * < 0 if the cgroup is over its limit
516 static int mem_cgroup_charge_common(struct page
*page
, struct mm_struct
*mm
,
517 gfp_t gfp_mask
, enum charge_type ctype
)
519 struct mem_cgroup
*mem
;
520 struct page_cgroup
*pc
;
522 unsigned long nr_retries
= MEM_CGROUP_RECLAIM_RETRIES
;
523 struct mem_cgroup_per_zone
*mz
;
525 if (mem_cgroup_subsys
.disabled
)
529 * Should page_cgroup's go to their own slab?
530 * One could optimize the performance of the charging routine
531 * by saving a bit in the page_flags and using it as a lock
532 * to see if the cgroup page already has a page_cgroup associated
536 lock_page_cgroup(page
);
537 pc
= page_get_page_cgroup(page
);
539 * The page_cgroup exists and
540 * the page has already been accounted.
543 VM_BUG_ON(pc
->page
!= page
);
544 VM_BUG_ON(pc
->ref_cnt
<= 0);
547 unlock_page_cgroup(page
);
550 unlock_page_cgroup(page
);
552 pc
= kmem_cache_zalloc(page_cgroup_cache
, gfp_mask
);
557 * We always charge the cgroup the mm_struct belongs to.
558 * The mm_struct's mem_cgroup changes on task migration if the
559 * thread group leader migrates. It's possible that mm is not
560 * set, if so charge the init_mm (happens for pagecache usage).
566 mem
= mem_cgroup_from_task(rcu_dereference(mm
->owner
));
568 * For every charge from the cgroup, increment reference count
573 while (res_counter_charge(&mem
->res
, PAGE_SIZE
)) {
574 if (!(gfp_mask
& __GFP_WAIT
))
577 if (try_to_free_mem_cgroup_pages(mem
, gfp_mask
))
581 * try_to_free_mem_cgroup_pages() might not give us a full
582 * picture of reclaim. Some pages are reclaimed and might be
583 * moved to swap cache or just unmapped from the cgroup.
584 * Check the limit again to see if the reclaim reduced the
585 * current usage of the cgroup before giving up
587 if (res_counter_check_under_limit(&mem
->res
))
591 mem_cgroup_out_of_memory(mem
, gfp_mask
);
594 congestion_wait(WRITE
, HZ
/10);
598 pc
->mem_cgroup
= mem
;
600 pc
->flags
= PAGE_CGROUP_FLAG_ACTIVE
;
601 if (ctype
== MEM_CGROUP_CHARGE_TYPE_CACHE
)
602 pc
->flags
|= PAGE_CGROUP_FLAG_CACHE
;
604 lock_page_cgroup(page
);
605 if (page_get_page_cgroup(page
)) {
606 unlock_page_cgroup(page
);
608 * Another charge has been added to this page already.
609 * We take lock_page_cgroup(page) again and read
610 * page->cgroup, increment refcnt.... just retry is OK.
612 res_counter_uncharge(&mem
->res
, PAGE_SIZE
);
614 kmem_cache_free(page_cgroup_cache
, pc
);
617 page_assign_page_cgroup(page
, pc
);
619 mz
= page_cgroup_zoneinfo(pc
);
620 spin_lock_irqsave(&mz
->lru_lock
, flags
);
621 __mem_cgroup_add_list(mz
, pc
);
622 spin_unlock_irqrestore(&mz
->lru_lock
, flags
);
624 unlock_page_cgroup(page
);
629 kmem_cache_free(page_cgroup_cache
, pc
);
634 int mem_cgroup_charge(struct page
*page
, struct mm_struct
*mm
, gfp_t gfp_mask
)
636 return mem_cgroup_charge_common(page
, mm
, gfp_mask
,
637 MEM_CGROUP_CHARGE_TYPE_MAPPED
);
640 int mem_cgroup_cache_charge(struct page
*page
, struct mm_struct
*mm
,
645 return mem_cgroup_charge_common(page
, mm
, gfp_mask
,
646 MEM_CGROUP_CHARGE_TYPE_CACHE
);
650 * Uncharging is always a welcome operation, we never complain, simply
653 void mem_cgroup_uncharge_page(struct page
*page
)
655 struct page_cgroup
*pc
;
656 struct mem_cgroup
*mem
;
657 struct mem_cgroup_per_zone
*mz
;
660 if (mem_cgroup_subsys
.disabled
)
664 * Check if our page_cgroup is valid
666 lock_page_cgroup(page
);
667 pc
= page_get_page_cgroup(page
);
671 VM_BUG_ON(pc
->page
!= page
);
672 VM_BUG_ON(pc
->ref_cnt
<= 0);
674 if (--(pc
->ref_cnt
) == 0) {
675 mz
= page_cgroup_zoneinfo(pc
);
676 spin_lock_irqsave(&mz
->lru_lock
, flags
);
677 __mem_cgroup_remove_list(mz
, pc
);
678 spin_unlock_irqrestore(&mz
->lru_lock
, flags
);
680 page_assign_page_cgroup(page
, NULL
);
681 unlock_page_cgroup(page
);
683 mem
= pc
->mem_cgroup
;
684 res_counter_uncharge(&mem
->res
, PAGE_SIZE
);
687 kmem_cache_free(page_cgroup_cache
, pc
);
692 unlock_page_cgroup(page
);
696 * Returns non-zero if a page (under migration) has valid page_cgroup member.
697 * Refcnt of page_cgroup is incremented.
699 int mem_cgroup_prepare_migration(struct page
*page
)
701 struct page_cgroup
*pc
;
703 if (mem_cgroup_subsys
.disabled
)
706 lock_page_cgroup(page
);
707 pc
= page_get_page_cgroup(page
);
710 unlock_page_cgroup(page
);
714 void mem_cgroup_end_migration(struct page
*page
)
716 mem_cgroup_uncharge_page(page
);
720 * We know both *page* and *newpage* are now not-on-LRU and PG_locked.
721 * And no race with uncharge() routines because page_cgroup for *page*
722 * has extra one reference by mem_cgroup_prepare_migration.
724 void mem_cgroup_page_migration(struct page
*page
, struct page
*newpage
)
726 struct page_cgroup
*pc
;
727 struct mem_cgroup_per_zone
*mz
;
730 lock_page_cgroup(page
);
731 pc
= page_get_page_cgroup(page
);
733 unlock_page_cgroup(page
);
737 mz
= page_cgroup_zoneinfo(pc
);
738 spin_lock_irqsave(&mz
->lru_lock
, flags
);
739 __mem_cgroup_remove_list(mz
, pc
);
740 spin_unlock_irqrestore(&mz
->lru_lock
, flags
);
742 page_assign_page_cgroup(page
, NULL
);
743 unlock_page_cgroup(page
);
746 lock_page_cgroup(newpage
);
747 page_assign_page_cgroup(newpage
, pc
);
749 mz
= page_cgroup_zoneinfo(pc
);
750 spin_lock_irqsave(&mz
->lru_lock
, flags
);
751 __mem_cgroup_add_list(mz
, pc
);
752 spin_unlock_irqrestore(&mz
->lru_lock
, flags
);
754 unlock_page_cgroup(newpage
);
758 * This routine traverse page_cgroup in given list and drop them all.
759 * This routine ignores page_cgroup->ref_cnt.
760 * *And* this routine doesn't reclaim page itself, just removes page_cgroup.
762 #define FORCE_UNCHARGE_BATCH (128)
763 static void mem_cgroup_force_empty_list(struct mem_cgroup
*mem
,
764 struct mem_cgroup_per_zone
*mz
,
767 struct page_cgroup
*pc
;
769 int count
= FORCE_UNCHARGE_BATCH
;
771 struct list_head
*list
;
774 list
= &mz
->active_list
;
776 list
= &mz
->inactive_list
;
778 spin_lock_irqsave(&mz
->lru_lock
, flags
);
779 while (!list_empty(list
)) {
780 pc
= list_entry(list
->prev
, struct page_cgroup
, lru
);
783 spin_unlock_irqrestore(&mz
->lru_lock
, flags
);
784 mem_cgroup_uncharge_page(page
);
787 count
= FORCE_UNCHARGE_BATCH
;
790 spin_lock_irqsave(&mz
->lru_lock
, flags
);
792 spin_unlock_irqrestore(&mz
->lru_lock
, flags
);
796 * make mem_cgroup's charge to be 0 if there is no task.
797 * This enables deleting this mem_cgroup.
799 static int mem_cgroup_force_empty(struct mem_cgroup
*mem
)
804 if (mem_cgroup_subsys
.disabled
)
809 * page reclaim code (kswapd etc..) will move pages between
810 * active_list <-> inactive_list while we don't take a lock.
811 * So, we have to do loop here until all lists are empty.
813 while (mem
->res
.usage
> 0) {
814 if (atomic_read(&mem
->css
.cgroup
->count
) > 0)
816 for_each_node_state(node
, N_POSSIBLE
)
817 for (zid
= 0; zid
< MAX_NR_ZONES
; zid
++) {
818 struct mem_cgroup_per_zone
*mz
;
819 mz
= mem_cgroup_zoneinfo(mem
, node
, zid
);
820 /* drop all page_cgroup in active_list */
821 mem_cgroup_force_empty_list(mem
, mz
, 1);
822 /* drop all page_cgroup in inactive_list */
823 mem_cgroup_force_empty_list(mem
, mz
, 0);
832 static int mem_cgroup_write_strategy(char *buf
, unsigned long long *tmp
)
834 *tmp
= memparse(buf
, &buf
);
839 * Round up the value to the closest page size
841 *tmp
= ((*tmp
+ PAGE_SIZE
- 1) >> PAGE_SHIFT
) << PAGE_SHIFT
;
845 static u64
mem_cgroup_read(struct cgroup
*cont
, struct cftype
*cft
)
847 return res_counter_read_u64(&mem_cgroup_from_cont(cont
)->res
,
851 static ssize_t
mem_cgroup_write(struct cgroup
*cont
, struct cftype
*cft
,
852 struct file
*file
, const char __user
*userbuf
,
853 size_t nbytes
, loff_t
*ppos
)
855 return res_counter_write(&mem_cgroup_from_cont(cont
)->res
,
856 cft
->private, userbuf
, nbytes
, ppos
,
857 mem_cgroup_write_strategy
);
860 static int mem_cgroup_reset(struct cgroup
*cont
, unsigned int event
)
862 struct mem_cgroup
*mem
;
864 mem
= mem_cgroup_from_cont(cont
);
867 res_counter_reset_max(&mem
->res
);
870 res_counter_reset_failcnt(&mem
->res
);
876 static int mem_force_empty_write(struct cgroup
*cont
, unsigned int event
)
878 return mem_cgroup_force_empty(mem_cgroup_from_cont(cont
));
881 static const struct mem_cgroup_stat_desc
{
884 } mem_cgroup_stat_desc
[] = {
885 [MEM_CGROUP_STAT_CACHE
] = { "cache", PAGE_SIZE
, },
886 [MEM_CGROUP_STAT_RSS
] = { "rss", PAGE_SIZE
, },
889 static int mem_control_stat_show(struct cgroup
*cont
, struct cftype
*cft
,
890 struct cgroup_map_cb
*cb
)
892 struct mem_cgroup
*mem_cont
= mem_cgroup_from_cont(cont
);
893 struct mem_cgroup_stat
*stat
= &mem_cont
->stat
;
896 for (i
= 0; i
< ARRAY_SIZE(stat
->cpustat
[0].count
); i
++) {
899 val
= mem_cgroup_read_stat(stat
, i
);
900 val
*= mem_cgroup_stat_desc
[i
].unit
;
901 cb
->fill(cb
, mem_cgroup_stat_desc
[i
].msg
, val
);
903 /* showing # of active pages */
905 unsigned long active
, inactive
;
907 inactive
= mem_cgroup_get_all_zonestat(mem_cont
,
908 MEM_CGROUP_ZSTAT_INACTIVE
);
909 active
= mem_cgroup_get_all_zonestat(mem_cont
,
910 MEM_CGROUP_ZSTAT_ACTIVE
);
911 cb
->fill(cb
, "active", (active
) * PAGE_SIZE
);
912 cb
->fill(cb
, "inactive", (inactive
) * PAGE_SIZE
);
917 static struct cftype mem_cgroup_files
[] = {
919 .name
= "usage_in_bytes",
920 .private = RES_USAGE
,
921 .read_u64
= mem_cgroup_read
,
924 .name
= "max_usage_in_bytes",
925 .private = RES_MAX_USAGE
,
926 .trigger
= mem_cgroup_reset
,
927 .read_u64
= mem_cgroup_read
,
930 .name
= "limit_in_bytes",
931 .private = RES_LIMIT
,
932 .write
= mem_cgroup_write
,
933 .read_u64
= mem_cgroup_read
,
937 .private = RES_FAILCNT
,
938 .trigger
= mem_cgroup_reset
,
939 .read_u64
= mem_cgroup_read
,
942 .name
= "force_empty",
943 .trigger
= mem_force_empty_write
,
947 .read_map
= mem_control_stat_show
,
951 static int alloc_mem_cgroup_per_zone_info(struct mem_cgroup
*mem
, int node
)
953 struct mem_cgroup_per_node
*pn
;
954 struct mem_cgroup_per_zone
*mz
;
955 int zone
, tmp
= node
;
957 * This routine is called against possible nodes.
958 * But it's BUG to call kmalloc() against offline node.
960 * TODO: this routine can waste much memory for nodes which will
961 * never be onlined. It's better to use memory hotplug callback
964 if (!node_state(node
, N_NORMAL_MEMORY
))
966 pn
= kmalloc_node(sizeof(*pn
), GFP_KERNEL
, tmp
);
970 mem
->info
.nodeinfo
[node
] = pn
;
971 memset(pn
, 0, sizeof(*pn
));
973 for (zone
= 0; zone
< MAX_NR_ZONES
; zone
++) {
974 mz
= &pn
->zoneinfo
[zone
];
975 INIT_LIST_HEAD(&mz
->active_list
);
976 INIT_LIST_HEAD(&mz
->inactive_list
);
977 spin_lock_init(&mz
->lru_lock
);
982 static void free_mem_cgroup_per_zone_info(struct mem_cgroup
*mem
, int node
)
984 kfree(mem
->info
.nodeinfo
[node
]);
987 static struct cgroup_subsys_state
*
988 mem_cgroup_create(struct cgroup_subsys
*ss
, struct cgroup
*cont
)
990 struct mem_cgroup
*mem
;
993 if (unlikely((cont
->parent
) == NULL
)) {
994 mem
= &init_mem_cgroup
;
995 page_cgroup_cache
= KMEM_CACHE(page_cgroup
, SLAB_PANIC
);
997 mem
= kzalloc(sizeof(struct mem_cgroup
), GFP_KERNEL
);
1001 return ERR_PTR(-ENOMEM
);
1003 res_counter_init(&mem
->res
);
1005 memset(&mem
->info
, 0, sizeof(mem
->info
));
1007 for_each_node_state(node
, N_POSSIBLE
)
1008 if (alloc_mem_cgroup_per_zone_info(mem
, node
))
1013 for_each_node_state(node
, N_POSSIBLE
)
1014 free_mem_cgroup_per_zone_info(mem
, node
);
1015 if (cont
->parent
!= NULL
)
1017 return ERR_PTR(-ENOMEM
);
1020 static void mem_cgroup_pre_destroy(struct cgroup_subsys
*ss
,
1021 struct cgroup
*cont
)
1023 struct mem_cgroup
*mem
= mem_cgroup_from_cont(cont
);
1024 mem_cgroup_force_empty(mem
);
1027 static void mem_cgroup_destroy(struct cgroup_subsys
*ss
,
1028 struct cgroup
*cont
)
1031 struct mem_cgroup
*mem
= mem_cgroup_from_cont(cont
);
1033 for_each_node_state(node
, N_POSSIBLE
)
1034 free_mem_cgroup_per_zone_info(mem
, node
);
1036 kfree(mem_cgroup_from_cont(cont
));
1039 static int mem_cgroup_populate(struct cgroup_subsys
*ss
,
1040 struct cgroup
*cont
)
1042 if (mem_cgroup_subsys
.disabled
)
1044 return cgroup_add_files(cont
, ss
, mem_cgroup_files
,
1045 ARRAY_SIZE(mem_cgroup_files
));
1048 static void mem_cgroup_move_task(struct cgroup_subsys
*ss
,
1049 struct cgroup
*cont
,
1050 struct cgroup
*old_cont
,
1051 struct task_struct
*p
)
1053 struct mm_struct
*mm
;
1054 struct mem_cgroup
*mem
, *old_mem
;
1056 if (mem_cgroup_subsys
.disabled
)
1059 mm
= get_task_mm(p
);
1063 mem
= mem_cgroup_from_cont(cont
);
1064 old_mem
= mem_cgroup_from_cont(old_cont
);
1070 * Only thread group leaders are allowed to migrate, the mm_struct is
1071 * in effect owned by the leader
1073 if (!thread_group_leader(p
))
1080 struct cgroup_subsys mem_cgroup_subsys
= {
1082 .subsys_id
= mem_cgroup_subsys_id
,
1083 .create
= mem_cgroup_create
,
1084 .pre_destroy
= mem_cgroup_pre_destroy
,
1085 .destroy
= mem_cgroup_destroy
,
1086 .populate
= mem_cgroup_populate
,
1087 .attach
= mem_cgroup_move_task
,