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/swap.h>
30 #include <linux/spinlock.h>
32 #include <linux/seq_file.h>
34 #include <asm/uaccess.h>
36 struct cgroup_subsys mem_cgroup_subsys
;
37 static const int MEM_CGROUP_RECLAIM_RETRIES
= 5;
40 * Statistics for memory cgroup.
42 enum mem_cgroup_stat_index
{
44 * For MEM_CONTAINER_TYPE_ALL, usage = pagecache + rss.
46 MEM_CGROUP_STAT_CACHE
, /* # of pages charged as cache */
47 MEM_CGROUP_STAT_RSS
, /* # of pages charged as rss */
49 MEM_CGROUP_STAT_NSTATS
,
52 struct mem_cgroup_stat_cpu
{
53 s64 count
[MEM_CGROUP_STAT_NSTATS
];
54 } ____cacheline_aligned_in_smp
;
56 struct mem_cgroup_stat
{
57 struct mem_cgroup_stat_cpu cpustat
[NR_CPUS
];
61 * For accounting under irq disable, no need for increment preempt count.
63 static void __mem_cgroup_stat_add_safe(struct mem_cgroup_stat
*stat
,
64 enum mem_cgroup_stat_index idx
, int val
)
66 int cpu
= smp_processor_id();
67 stat
->cpustat
[cpu
].count
[idx
] += val
;
70 static s64
mem_cgroup_read_stat(struct mem_cgroup_stat
*stat
,
71 enum mem_cgroup_stat_index idx
)
75 for_each_possible_cpu(cpu
)
76 ret
+= stat
->cpustat
[cpu
].count
[idx
];
81 * per-zone information in memory controller.
84 enum mem_cgroup_zstat_index
{
85 MEM_CGROUP_ZSTAT_ACTIVE
,
86 MEM_CGROUP_ZSTAT_INACTIVE
,
91 struct mem_cgroup_per_zone
{
92 unsigned long count
[NR_MEM_CGROUP_ZSTAT
];
94 /* Macro for accessing counter */
95 #define MEM_CGROUP_ZSTAT(mz, idx) ((mz)->count[(idx)])
97 struct mem_cgroup_per_node
{
98 struct mem_cgroup_per_zone zoneinfo
[MAX_NR_ZONES
];
101 struct mem_cgroup_lru_info
{
102 struct mem_cgroup_per_node
*nodeinfo
[MAX_NUMNODES
];
106 * The memory controller data structure. The memory controller controls both
107 * page cache and RSS per cgroup. We would eventually like to provide
108 * statistics based on the statistics developed by Rik Van Riel for clock-pro,
109 * to help the administrator determine what knobs to tune.
111 * TODO: Add a water mark for the memory controller. Reclaim will begin when
112 * we hit the water mark. May be even add a low water mark, such that
113 * no reclaim occurs from a cgroup at it's low water mark, this is
114 * a feature that will be implemented much later in the future.
117 struct cgroup_subsys_state css
;
119 * the counter to account for memory usage
121 struct res_counter res
;
123 * Per cgroup active and inactive list, similar to the
124 * per zone LRU lists.
125 * TODO: Consider making these lists per zone
127 struct list_head active_list
;
128 struct list_head inactive_list
;
129 struct mem_cgroup_lru_info info
;
131 * spin_lock to protect the per cgroup LRU
134 unsigned long control_type
; /* control RSS or RSS+Pagecache */
135 int prev_priority
; /* for recording reclaim priority */
139 struct mem_cgroup_stat stat
;
143 * We use the lower bit of the page->page_cgroup pointer as a bit spin
144 * lock. We need to ensure that page->page_cgroup is atleast two
145 * byte aligned (based on comments from Nick Piggin)
147 #define PAGE_CGROUP_LOCK_BIT 0x0
148 #define PAGE_CGROUP_LOCK (1 << PAGE_CGROUP_LOCK_BIT)
151 * A page_cgroup page is associated with every page descriptor. The
152 * page_cgroup helps us identify information about the cgroup
155 struct list_head lru
; /* per cgroup LRU list */
157 struct mem_cgroup
*mem_cgroup
;
158 atomic_t ref_cnt
; /* Helpful when pages move b/w */
159 /* mapped and cached states */
162 #define PAGE_CGROUP_FLAG_CACHE (0x1) /* charged as cache */
163 #define PAGE_CGROUP_FLAG_ACTIVE (0x2) /* page is active in this cgroup */
165 static inline int page_cgroup_nid(struct page_cgroup
*pc
)
167 return page_to_nid(pc
->page
);
170 static inline enum zone_type
page_cgroup_zid(struct page_cgroup
*pc
)
172 return page_zonenum(pc
->page
);
176 MEM_CGROUP_TYPE_UNSPEC
= 0,
177 MEM_CGROUP_TYPE_MAPPED
,
178 MEM_CGROUP_TYPE_CACHED
,
184 MEM_CGROUP_CHARGE_TYPE_CACHE
= 0,
185 MEM_CGROUP_CHARGE_TYPE_MAPPED
,
190 * Always modified under lru lock. Then, not necessary to preempt_disable()
192 static void mem_cgroup_charge_statistics(struct mem_cgroup
*mem
, int flags
,
195 int val
= (charge
)? 1 : -1;
196 struct mem_cgroup_stat
*stat
= &mem
->stat
;
197 VM_BUG_ON(!irqs_disabled());
199 if (flags
& PAGE_CGROUP_FLAG_CACHE
)
200 __mem_cgroup_stat_add_safe(stat
,
201 MEM_CGROUP_STAT_CACHE
, val
);
203 __mem_cgroup_stat_add_safe(stat
, MEM_CGROUP_STAT_RSS
, val
);
206 static inline struct mem_cgroup_per_zone
*
207 mem_cgroup_zoneinfo(struct mem_cgroup
*mem
, int nid
, int zid
)
209 BUG_ON(!mem
->info
.nodeinfo
[nid
]);
210 return &mem
->info
.nodeinfo
[nid
]->zoneinfo
[zid
];
213 static inline struct mem_cgroup_per_zone
*
214 page_cgroup_zoneinfo(struct page_cgroup
*pc
)
216 struct mem_cgroup
*mem
= pc
->mem_cgroup
;
217 int nid
= page_cgroup_nid(pc
);
218 int zid
= page_cgroup_zid(pc
);
220 return mem_cgroup_zoneinfo(mem
, nid
, zid
);
223 static unsigned long mem_cgroup_get_all_zonestat(struct mem_cgroup
*mem
,
224 enum mem_cgroup_zstat_index idx
)
227 struct mem_cgroup_per_zone
*mz
;
230 for_each_online_node(nid
)
231 for (zid
= 0; zid
< MAX_NR_ZONES
; zid
++) {
232 mz
= mem_cgroup_zoneinfo(mem
, nid
, zid
);
233 total
+= MEM_CGROUP_ZSTAT(mz
, idx
);
238 static struct mem_cgroup init_mem_cgroup
;
241 struct mem_cgroup
*mem_cgroup_from_cont(struct cgroup
*cont
)
243 return container_of(cgroup_subsys_state(cont
,
244 mem_cgroup_subsys_id
), struct mem_cgroup
,
249 struct mem_cgroup
*mem_cgroup_from_task(struct task_struct
*p
)
251 return container_of(task_subsys_state(p
, mem_cgroup_subsys_id
),
252 struct mem_cgroup
, css
);
255 void mm_init_cgroup(struct mm_struct
*mm
, struct task_struct
*p
)
257 struct mem_cgroup
*mem
;
259 mem
= mem_cgroup_from_task(p
);
261 mm
->mem_cgroup
= mem
;
264 void mm_free_cgroup(struct mm_struct
*mm
)
266 css_put(&mm
->mem_cgroup
->css
);
269 static inline int page_cgroup_locked(struct page
*page
)
271 return bit_spin_is_locked(PAGE_CGROUP_LOCK_BIT
,
275 void page_assign_page_cgroup(struct page
*page
, struct page_cgroup
*pc
)
280 * While resetting the page_cgroup we might not hold the
281 * page_cgroup lock. free_hot_cold_page() is an example
285 VM_BUG_ON(!page_cgroup_locked(page
));
286 locked
= (page
->page_cgroup
& PAGE_CGROUP_LOCK
);
287 page
->page_cgroup
= ((unsigned long)pc
| locked
);
290 struct page_cgroup
*page_get_page_cgroup(struct page
*page
)
292 return (struct page_cgroup
*)
293 (page
->page_cgroup
& ~PAGE_CGROUP_LOCK
);
296 static void __always_inline
lock_page_cgroup(struct page
*page
)
298 bit_spin_lock(PAGE_CGROUP_LOCK_BIT
, &page
->page_cgroup
);
299 VM_BUG_ON(!page_cgroup_locked(page
));
302 static void __always_inline
unlock_page_cgroup(struct page
*page
)
304 bit_spin_unlock(PAGE_CGROUP_LOCK_BIT
, &page
->page_cgroup
);
308 * Tie new page_cgroup to struct page under lock_page_cgroup()
309 * This can fail if the page has been tied to a page_cgroup.
310 * If success, returns 0.
312 static int page_cgroup_assign_new_page_cgroup(struct page
*page
,
313 struct page_cgroup
*pc
)
317 lock_page_cgroup(page
);
318 if (!page_get_page_cgroup(page
))
319 page_assign_page_cgroup(page
, pc
);
320 else /* A page is tied to other pc. */
322 unlock_page_cgroup(page
);
327 * Clear page->page_cgroup member under lock_page_cgroup().
328 * If given "pc" value is different from one page->page_cgroup,
329 * page->cgroup is not cleared.
330 * Returns a value of page->page_cgroup at lock taken.
331 * A can can detect failure of clearing by following
332 * clear_page_cgroup(page, pc) == pc
335 static struct page_cgroup
*clear_page_cgroup(struct page
*page
,
336 struct page_cgroup
*pc
)
338 struct page_cgroup
*ret
;
340 lock_page_cgroup(page
);
341 ret
= page_get_page_cgroup(page
);
342 if (likely(ret
== pc
))
343 page_assign_page_cgroup(page
, NULL
);
344 unlock_page_cgroup(page
);
348 static void __mem_cgroup_remove_list(struct page_cgroup
*pc
)
350 int from
= pc
->flags
& PAGE_CGROUP_FLAG_ACTIVE
;
351 struct mem_cgroup_per_zone
*mz
= page_cgroup_zoneinfo(pc
);
354 MEM_CGROUP_ZSTAT(mz
, MEM_CGROUP_ZSTAT_ACTIVE
) -= 1;
356 MEM_CGROUP_ZSTAT(mz
, MEM_CGROUP_ZSTAT_INACTIVE
) -= 1;
358 mem_cgroup_charge_statistics(pc
->mem_cgroup
, pc
->flags
, false);
359 list_del_init(&pc
->lru
);
362 static void __mem_cgroup_add_list(struct page_cgroup
*pc
)
364 int to
= pc
->flags
& PAGE_CGROUP_FLAG_ACTIVE
;
365 struct mem_cgroup_per_zone
*mz
= page_cgroup_zoneinfo(pc
);
368 MEM_CGROUP_ZSTAT(mz
, MEM_CGROUP_ZSTAT_INACTIVE
) += 1;
369 list_add(&pc
->lru
, &pc
->mem_cgroup
->inactive_list
);
371 MEM_CGROUP_ZSTAT(mz
, MEM_CGROUP_ZSTAT_ACTIVE
) += 1;
372 list_add(&pc
->lru
, &pc
->mem_cgroup
->active_list
);
374 mem_cgroup_charge_statistics(pc
->mem_cgroup
, pc
->flags
, true);
377 static void __mem_cgroup_move_lists(struct page_cgroup
*pc
, bool active
)
379 int from
= pc
->flags
& PAGE_CGROUP_FLAG_ACTIVE
;
380 struct mem_cgroup_per_zone
*mz
= page_cgroup_zoneinfo(pc
);
383 MEM_CGROUP_ZSTAT(mz
, MEM_CGROUP_ZSTAT_ACTIVE
) -= 1;
385 MEM_CGROUP_ZSTAT(mz
, MEM_CGROUP_ZSTAT_INACTIVE
) -= 1;
388 MEM_CGROUP_ZSTAT(mz
, MEM_CGROUP_ZSTAT_ACTIVE
) += 1;
389 pc
->flags
|= PAGE_CGROUP_FLAG_ACTIVE
;
390 list_move(&pc
->lru
, &pc
->mem_cgroup
->active_list
);
392 MEM_CGROUP_ZSTAT(mz
, MEM_CGROUP_ZSTAT_INACTIVE
) += 1;
393 pc
->flags
&= ~PAGE_CGROUP_FLAG_ACTIVE
;
394 list_move(&pc
->lru
, &pc
->mem_cgroup
->inactive_list
);
398 int task_in_mem_cgroup(struct task_struct
*task
, const struct mem_cgroup
*mem
)
403 ret
= task
->mm
&& mm_cgroup(task
->mm
) == mem
;
409 * This routine assumes that the appropriate zone's lru lock is already held
411 void mem_cgroup_move_lists(struct page_cgroup
*pc
, bool active
)
413 struct mem_cgroup
*mem
;
417 mem
= pc
->mem_cgroup
;
419 spin_lock(&mem
->lru_lock
);
420 __mem_cgroup_move_lists(pc
, active
);
421 spin_unlock(&mem
->lru_lock
);
425 * Calculate mapped_ratio under memory controller. This will be used in
426 * vmscan.c for deteremining we have to reclaim mapped pages.
428 int mem_cgroup_calc_mapped_ratio(struct mem_cgroup
*mem
)
433 * usage is recorded in bytes. But, here, we assume the number of
434 * physical pages can be represented by "long" on any arch.
436 total
= (long) (mem
->res
.usage
>> PAGE_SHIFT
) + 1L;
437 rss
= (long)mem_cgroup_read_stat(&mem
->stat
, MEM_CGROUP_STAT_RSS
);
438 return (int)((rss
* 100L) / total
);
441 * This function is called from vmscan.c. In page reclaiming loop. balance
442 * between active and inactive list is calculated. For memory controller
443 * page reclaiming, we should use using mem_cgroup's imbalance rather than
444 * zone's global lru imbalance.
446 long mem_cgroup_reclaim_imbalance(struct mem_cgroup
*mem
)
448 unsigned long active
, inactive
;
449 /* active and inactive are the number of pages. 'long' is ok.*/
450 active
= mem_cgroup_get_all_zonestat(mem
, MEM_CGROUP_ZSTAT_ACTIVE
);
451 inactive
= mem_cgroup_get_all_zonestat(mem
, MEM_CGROUP_ZSTAT_INACTIVE
);
452 return (long) (active
/ (inactive
+ 1));
456 * prev_priority control...this will be used in memory reclaim path.
458 int mem_cgroup_get_reclaim_priority(struct mem_cgroup
*mem
)
460 return mem
->prev_priority
;
463 void mem_cgroup_note_reclaim_priority(struct mem_cgroup
*mem
, int priority
)
465 if (priority
< mem
->prev_priority
)
466 mem
->prev_priority
= priority
;
469 void mem_cgroup_record_reclaim_priority(struct mem_cgroup
*mem
, int priority
)
471 mem
->prev_priority
= priority
;
474 unsigned long mem_cgroup_isolate_pages(unsigned long nr_to_scan
,
475 struct list_head
*dst
,
476 unsigned long *scanned
, int order
,
477 int mode
, struct zone
*z
,
478 struct mem_cgroup
*mem_cont
,
481 unsigned long nr_taken
= 0;
485 struct list_head
*src
;
486 struct page_cgroup
*pc
, *tmp
;
489 src
= &mem_cont
->active_list
;
491 src
= &mem_cont
->inactive_list
;
493 spin_lock(&mem_cont
->lru_lock
);
495 list_for_each_entry_safe_reverse(pc
, tmp
, src
, lru
) {
496 if (scan
>= nr_to_scan
)
501 if (unlikely(!PageLRU(page
)))
504 if (PageActive(page
) && !active
) {
505 __mem_cgroup_move_lists(pc
, true);
508 if (!PageActive(page
) && active
) {
509 __mem_cgroup_move_lists(pc
, false);
515 * TODO: make the active/inactive lists per zone
517 if (page_zone(page
) != z
)
521 list_move(&pc
->lru
, &pc_list
);
523 if (__isolate_lru_page(page
, mode
) == 0) {
524 list_move(&page
->lru
, dst
);
529 list_splice(&pc_list
, src
);
530 spin_unlock(&mem_cont
->lru_lock
);
537 * Charge the memory controller for page usage.
539 * 0 if the charge was successful
540 * < 0 if the cgroup is over its limit
542 static int mem_cgroup_charge_common(struct page
*page
, struct mm_struct
*mm
,
543 gfp_t gfp_mask
, enum charge_type ctype
)
545 struct mem_cgroup
*mem
;
546 struct page_cgroup
*pc
;
548 unsigned long nr_retries
= MEM_CGROUP_RECLAIM_RETRIES
;
551 * Should page_cgroup's go to their own slab?
552 * One could optimize the performance of the charging routine
553 * by saving a bit in the page_flags and using it as a lock
554 * to see if the cgroup page already has a page_cgroup associated
559 lock_page_cgroup(page
);
560 pc
= page_get_page_cgroup(page
);
562 * The page_cgroup exists and
563 * the page has already been accounted.
566 if (unlikely(!atomic_inc_not_zero(&pc
->ref_cnt
))) {
567 /* this page is under being uncharged ? */
568 unlock_page_cgroup(page
);
572 unlock_page_cgroup(page
);
576 unlock_page_cgroup(page
);
579 pc
= kzalloc(sizeof(struct page_cgroup
), gfp_mask
);
584 * We always charge the cgroup the mm_struct belongs to.
585 * The mm_struct's mem_cgroup changes on task migration if the
586 * thread group leader migrates. It's possible that mm is not
587 * set, if so charge the init_mm (happens for pagecache usage).
593 mem
= rcu_dereference(mm
->mem_cgroup
);
595 * For every charge from the cgroup, increment reference
602 * If we created the page_cgroup, we should free it on exceeding
605 while (res_counter_charge(&mem
->res
, PAGE_SIZE
)) {
606 if (!(gfp_mask
& __GFP_WAIT
))
609 if (try_to_free_mem_cgroup_pages(mem
, gfp_mask
))
613 * try_to_free_mem_cgroup_pages() might not give us a full
614 * picture of reclaim. Some pages are reclaimed and might be
615 * moved to swap cache or just unmapped from the cgroup.
616 * Check the limit again to see if the reclaim reduced the
617 * current usage of the cgroup before giving up
619 if (res_counter_check_under_limit(&mem
->res
))
623 mem_cgroup_out_of_memory(mem
, gfp_mask
);
626 congestion_wait(WRITE
, HZ
/10);
629 atomic_set(&pc
->ref_cnt
, 1);
630 pc
->mem_cgroup
= mem
;
632 pc
->flags
= PAGE_CGROUP_FLAG_ACTIVE
;
633 if (ctype
== MEM_CGROUP_CHARGE_TYPE_CACHE
)
634 pc
->flags
|= PAGE_CGROUP_FLAG_CACHE
;
636 if (!page
|| page_cgroup_assign_new_page_cgroup(page
, pc
)) {
638 * Another charge has been added to this page already.
639 * We take lock_page_cgroup(page) again and read
640 * page->cgroup, increment refcnt.... just retry is OK.
642 res_counter_uncharge(&mem
->res
, PAGE_SIZE
);
650 spin_lock_irqsave(&mem
->lru_lock
, flags
);
651 /* Update statistics vector */
652 __mem_cgroup_add_list(pc
);
653 spin_unlock_irqrestore(&mem
->lru_lock
, flags
);
664 int mem_cgroup_charge(struct page
*page
, struct mm_struct
*mm
,
667 return mem_cgroup_charge_common(page
, mm
, gfp_mask
,
668 MEM_CGROUP_CHARGE_TYPE_MAPPED
);
672 * See if the cached pages should be charged at all?
674 int mem_cgroup_cache_charge(struct page
*page
, struct mm_struct
*mm
,
678 struct mem_cgroup
*mem
;
683 mem
= rcu_dereference(mm
->mem_cgroup
);
686 if (mem
->control_type
== MEM_CGROUP_TYPE_ALL
)
687 ret
= mem_cgroup_charge_common(page
, mm
, gfp_mask
,
688 MEM_CGROUP_CHARGE_TYPE_CACHE
);
694 * Uncharging is always a welcome operation, we never complain, simply
697 void mem_cgroup_uncharge(struct page_cgroup
*pc
)
699 struct mem_cgroup
*mem
;
704 * This can handle cases when a page is not charged at all and we
705 * are switching between handling the control_type.
710 if (atomic_dec_and_test(&pc
->ref_cnt
)) {
713 * get page->cgroup and clear it under lock.
714 * force_empty can drop page->cgroup without checking refcnt.
716 if (clear_page_cgroup(page
, pc
) == pc
) {
717 mem
= pc
->mem_cgroup
;
719 res_counter_uncharge(&mem
->res
, PAGE_SIZE
);
720 spin_lock_irqsave(&mem
->lru_lock
, flags
);
721 __mem_cgroup_remove_list(pc
);
722 spin_unlock_irqrestore(&mem
->lru_lock
, flags
);
729 * Returns non-zero if a page (under migration) has valid page_cgroup member.
730 * Refcnt of page_cgroup is incremented.
733 int mem_cgroup_prepare_migration(struct page
*page
)
735 struct page_cgroup
*pc
;
737 lock_page_cgroup(page
);
738 pc
= page_get_page_cgroup(page
);
739 if (pc
&& atomic_inc_not_zero(&pc
->ref_cnt
))
741 unlock_page_cgroup(page
);
745 void mem_cgroup_end_migration(struct page
*page
)
747 struct page_cgroup
*pc
= page_get_page_cgroup(page
);
748 mem_cgroup_uncharge(pc
);
751 * We know both *page* and *newpage* are now not-on-LRU and Pg_locked.
752 * And no race with uncharge() routines because page_cgroup for *page*
753 * has extra one reference by mem_cgroup_prepare_migration.
756 void mem_cgroup_page_migration(struct page
*page
, struct page
*newpage
)
758 struct page_cgroup
*pc
;
759 struct mem_cgroup
*mem
;
762 pc
= page_get_page_cgroup(page
);
765 mem
= pc
->mem_cgroup
;
766 if (clear_page_cgroup(page
, pc
) != pc
)
769 spin_lock_irqsave(&mem
->lru_lock
, flags
);
771 __mem_cgroup_remove_list(pc
);
773 lock_page_cgroup(newpage
);
774 page_assign_page_cgroup(newpage
, pc
);
775 unlock_page_cgroup(newpage
);
776 __mem_cgroup_add_list(pc
);
778 spin_unlock_irqrestore(&mem
->lru_lock
, flags
);
783 * This routine traverse page_cgroup in given list and drop them all.
784 * This routine ignores page_cgroup->ref_cnt.
785 * *And* this routine doesn't reclaim page itself, just removes page_cgroup.
787 #define FORCE_UNCHARGE_BATCH (128)
789 mem_cgroup_force_empty_list(struct mem_cgroup
*mem
, struct list_head
*list
)
791 struct page_cgroup
*pc
;
797 count
= FORCE_UNCHARGE_BATCH
;
798 spin_lock_irqsave(&mem
->lru_lock
, flags
);
800 while (--count
&& !list_empty(list
)) {
801 pc
= list_entry(list
->prev
, struct page_cgroup
, lru
);
803 /* Avoid race with charge */
804 atomic_set(&pc
->ref_cnt
, 0);
805 if (clear_page_cgroup(page
, pc
) == pc
) {
807 res_counter_uncharge(&mem
->res
, PAGE_SIZE
);
808 __mem_cgroup_remove_list(pc
);
810 } else /* being uncharged ? ...do relax */
813 spin_unlock_irqrestore(&mem
->lru_lock
, flags
);
814 if (!list_empty(list
)) {
822 * make mem_cgroup's charge to be 0 if there is no task.
823 * This enables deleting this mem_cgroup.
826 int mem_cgroup_force_empty(struct mem_cgroup
*mem
)
831 * page reclaim code (kswapd etc..) will move pages between
832 ` * active_list <-> inactive_list while we don't take a lock.
833 * So, we have to do loop here until all lists are empty.
835 while (!(list_empty(&mem
->active_list
) &&
836 list_empty(&mem
->inactive_list
))) {
837 if (atomic_read(&mem
->css
.cgroup
->count
) > 0)
839 /* drop all page_cgroup in active_list */
840 mem_cgroup_force_empty_list(mem
, &mem
->active_list
);
841 /* drop all page_cgroup in inactive_list */
842 mem_cgroup_force_empty_list(mem
, &mem
->inactive_list
);
852 int mem_cgroup_write_strategy(char *buf
, unsigned long long *tmp
)
854 *tmp
= memparse(buf
, &buf
);
859 * Round up the value to the closest page size
861 *tmp
= ((*tmp
+ PAGE_SIZE
- 1) >> PAGE_SHIFT
) << PAGE_SHIFT
;
865 static ssize_t
mem_cgroup_read(struct cgroup
*cont
,
866 struct cftype
*cft
, struct file
*file
,
867 char __user
*userbuf
, size_t nbytes
, loff_t
*ppos
)
869 return res_counter_read(&mem_cgroup_from_cont(cont
)->res
,
870 cft
->private, userbuf
, nbytes
, ppos
,
874 static ssize_t
mem_cgroup_write(struct cgroup
*cont
, struct cftype
*cft
,
875 struct file
*file
, const char __user
*userbuf
,
876 size_t nbytes
, loff_t
*ppos
)
878 return res_counter_write(&mem_cgroup_from_cont(cont
)->res
,
879 cft
->private, userbuf
, nbytes
, ppos
,
880 mem_cgroup_write_strategy
);
883 static ssize_t
mem_control_type_write(struct cgroup
*cont
,
884 struct cftype
*cft
, struct file
*file
,
885 const char __user
*userbuf
,
886 size_t nbytes
, loff_t
*pos
)
891 struct mem_cgroup
*mem
;
893 mem
= mem_cgroup_from_cont(cont
);
894 buf
= kmalloc(nbytes
+ 1, GFP_KERNEL
);
901 if (copy_from_user(buf
, userbuf
, nbytes
))
905 tmp
= simple_strtoul(buf
, &end
, 10);
909 if (tmp
<= MEM_CGROUP_TYPE_UNSPEC
|| tmp
>= MEM_CGROUP_TYPE_MAX
)
912 mem
->control_type
= tmp
;
920 static ssize_t
mem_control_type_read(struct cgroup
*cont
,
922 struct file
*file
, char __user
*userbuf
,
923 size_t nbytes
, loff_t
*ppos
)
927 struct mem_cgroup
*mem
;
929 mem
= mem_cgroup_from_cont(cont
);
931 val
= mem
->control_type
;
932 s
+= sprintf(s
, "%lu\n", val
);
933 return simple_read_from_buffer((void __user
*)userbuf
, nbytes
,
938 static ssize_t
mem_force_empty_write(struct cgroup
*cont
,
939 struct cftype
*cft
, struct file
*file
,
940 const char __user
*userbuf
,
941 size_t nbytes
, loff_t
*ppos
)
943 struct mem_cgroup
*mem
= mem_cgroup_from_cont(cont
);
945 ret
= mem_cgroup_force_empty(mem
);
952 * Note: This should be removed if cgroup supports write-only file.
955 static ssize_t
mem_force_empty_read(struct cgroup
*cont
,
957 struct file
*file
, char __user
*userbuf
,
958 size_t nbytes
, loff_t
*ppos
)
964 static const struct mem_cgroup_stat_desc
{
967 } mem_cgroup_stat_desc
[] = {
968 [MEM_CGROUP_STAT_CACHE
] = { "cache", PAGE_SIZE
, },
969 [MEM_CGROUP_STAT_RSS
] = { "rss", PAGE_SIZE
, },
972 static int mem_control_stat_show(struct seq_file
*m
, void *arg
)
974 struct cgroup
*cont
= m
->private;
975 struct mem_cgroup
*mem_cont
= mem_cgroup_from_cont(cont
);
976 struct mem_cgroup_stat
*stat
= &mem_cont
->stat
;
979 for (i
= 0; i
< ARRAY_SIZE(stat
->cpustat
[0].count
); i
++) {
982 val
= mem_cgroup_read_stat(stat
, i
);
983 val
*= mem_cgroup_stat_desc
[i
].unit
;
984 seq_printf(m
, "%s %lld\n", mem_cgroup_stat_desc
[i
].msg
,
987 /* showing # of active pages */
989 unsigned long active
, inactive
;
991 inactive
= mem_cgroup_get_all_zonestat(mem_cont
,
992 MEM_CGROUP_ZSTAT_INACTIVE
);
993 active
= mem_cgroup_get_all_zonestat(mem_cont
,
994 MEM_CGROUP_ZSTAT_ACTIVE
);
995 seq_printf(m
, "active %ld\n", (active
) * PAGE_SIZE
);
996 seq_printf(m
, "inactive %ld\n", (inactive
) * PAGE_SIZE
);
1001 static const struct file_operations mem_control_stat_file_operations
= {
1003 .llseek
= seq_lseek
,
1004 .release
= single_release
,
1007 static int mem_control_stat_open(struct inode
*unused
, struct file
*file
)
1010 struct cgroup
*cont
= file
->f_dentry
->d_parent
->d_fsdata
;
1012 file
->f_op
= &mem_control_stat_file_operations
;
1013 return single_open(file
, mem_control_stat_show
, cont
);
1018 static struct cftype mem_cgroup_files
[] = {
1020 .name
= "usage_in_bytes",
1021 .private = RES_USAGE
,
1022 .read
= mem_cgroup_read
,
1025 .name
= "limit_in_bytes",
1026 .private = RES_LIMIT
,
1027 .write
= mem_cgroup_write
,
1028 .read
= mem_cgroup_read
,
1032 .private = RES_FAILCNT
,
1033 .read
= mem_cgroup_read
,
1036 .name
= "control_type",
1037 .write
= mem_control_type_write
,
1038 .read
= mem_control_type_read
,
1041 .name
= "force_empty",
1042 .write
= mem_force_empty_write
,
1043 .read
= mem_force_empty_read
,
1047 .open
= mem_control_stat_open
,
1051 static int alloc_mem_cgroup_per_zone_info(struct mem_cgroup
*mem
, int node
)
1053 struct mem_cgroup_per_node
*pn
;
1055 pn
= kmalloc_node(sizeof(*pn
), GFP_KERNEL
, node
);
1058 mem
->info
.nodeinfo
[node
] = pn
;
1059 memset(pn
, 0, sizeof(*pn
));
1063 static struct mem_cgroup init_mem_cgroup
;
1065 static struct cgroup_subsys_state
*
1066 mem_cgroup_create(struct cgroup_subsys
*ss
, struct cgroup
*cont
)
1068 struct mem_cgroup
*mem
;
1071 if (unlikely((cont
->parent
) == NULL
)) {
1072 mem
= &init_mem_cgroup
;
1073 init_mm
.mem_cgroup
= mem
;
1075 mem
= kzalloc(sizeof(struct mem_cgroup
), GFP_KERNEL
);
1080 res_counter_init(&mem
->res
);
1081 INIT_LIST_HEAD(&mem
->active_list
);
1082 INIT_LIST_HEAD(&mem
->inactive_list
);
1083 spin_lock_init(&mem
->lru_lock
);
1084 mem
->control_type
= MEM_CGROUP_TYPE_ALL
;
1085 memset(&mem
->info
, 0, sizeof(mem
->info
));
1087 for_each_node_state(node
, N_POSSIBLE
)
1088 if (alloc_mem_cgroup_per_zone_info(mem
, node
))
1093 for_each_node_state(node
, N_POSSIBLE
)
1094 kfree(mem
->info
.nodeinfo
[node
]);
1095 if (cont
->parent
!= NULL
)
1100 static void mem_cgroup_pre_destroy(struct cgroup_subsys
*ss
,
1101 struct cgroup
*cont
)
1103 struct mem_cgroup
*mem
= mem_cgroup_from_cont(cont
);
1104 mem_cgroup_force_empty(mem
);
1107 static void mem_cgroup_destroy(struct cgroup_subsys
*ss
,
1108 struct cgroup
*cont
)
1111 struct mem_cgroup
*mem
= mem_cgroup_from_cont(cont
);
1113 for_each_node_state(node
, N_POSSIBLE
)
1114 kfree(mem
->info
.nodeinfo
[node
]);
1116 kfree(mem_cgroup_from_cont(cont
));
1119 static int mem_cgroup_populate(struct cgroup_subsys
*ss
,
1120 struct cgroup
*cont
)
1122 return cgroup_add_files(cont
, ss
, mem_cgroup_files
,
1123 ARRAY_SIZE(mem_cgroup_files
));
1126 static void mem_cgroup_move_task(struct cgroup_subsys
*ss
,
1127 struct cgroup
*cont
,
1128 struct cgroup
*old_cont
,
1129 struct task_struct
*p
)
1131 struct mm_struct
*mm
;
1132 struct mem_cgroup
*mem
, *old_mem
;
1134 mm
= get_task_mm(p
);
1138 mem
= mem_cgroup_from_cont(cont
);
1139 old_mem
= mem_cgroup_from_cont(old_cont
);
1145 * Only thread group leaders are allowed to migrate, the mm_struct is
1146 * in effect owned by the leader
1148 if (p
->tgid
!= p
->pid
)
1152 rcu_assign_pointer(mm
->mem_cgroup
, mem
);
1153 css_put(&old_mem
->css
);
1160 struct cgroup_subsys mem_cgroup_subsys
= {
1162 .subsys_id
= mem_cgroup_subsys_id
,
1163 .create
= mem_cgroup_create
,
1164 .pre_destroy
= mem_cgroup_pre_destroy
,
1165 .destroy
= mem_cgroup_destroy
,
1166 .populate
= mem_cgroup_populate
,
1167 .attach
= mem_cgroup_move_task
,