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/pagemap.h>
25 #include <linux/smp.h>
26 #include <linux/page-flags.h>
27 #include <linux/backing-dev.h>
28 #include <linux/bit_spinlock.h>
29 #include <linux/rcupdate.h>
30 #include <linux/limits.h>
31 #include <linux/mutex.h>
32 #include <linux/slab.h>
33 #include <linux/swap.h>
34 #include <linux/spinlock.h>
36 #include <linux/seq_file.h>
37 #include <linux/vmalloc.h>
38 #include <linux/mm_inline.h>
39 #include <linux/page_cgroup.h>
42 #include <asm/uaccess.h>
44 struct cgroup_subsys mem_cgroup_subsys __read_mostly
;
45 #define MEM_CGROUP_RECLAIM_RETRIES 5
47 #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP
48 /* Turned on only when memory cgroup is enabled && really_do_swap_account = 1 */
49 int do_swap_account __read_mostly
;
50 static int really_do_swap_account __initdata
= 1; /* for remember boot option*/
52 #define do_swap_account (0)
55 static DEFINE_MUTEX(memcg_tasklist
); /* can be hold under cgroup_mutex */
58 * Statistics for memory cgroup.
60 enum mem_cgroup_stat_index
{
62 * For MEM_CONTAINER_TYPE_ALL, usage = pagecache + rss.
64 MEM_CGROUP_STAT_CACHE
, /* # of pages charged as cache */
65 MEM_CGROUP_STAT_RSS
, /* # of pages charged as anon rss */
66 MEM_CGROUP_STAT_MAPPED_FILE
, /* # of pages charged as file rss */
67 MEM_CGROUP_STAT_PGPGIN_COUNT
, /* # of pages paged in */
68 MEM_CGROUP_STAT_PGPGOUT_COUNT
, /* # of pages paged out */
70 MEM_CGROUP_STAT_NSTATS
,
73 struct mem_cgroup_stat_cpu
{
74 s64 count
[MEM_CGROUP_STAT_NSTATS
];
75 } ____cacheline_aligned_in_smp
;
77 struct mem_cgroup_stat
{
78 struct mem_cgroup_stat_cpu cpustat
[0];
82 * For accounting under irq disable, no need for increment preempt count.
84 static inline void __mem_cgroup_stat_add_safe(struct mem_cgroup_stat_cpu
*stat
,
85 enum mem_cgroup_stat_index idx
, int val
)
87 stat
->count
[idx
] += val
;
90 static s64
mem_cgroup_read_stat(struct mem_cgroup_stat
*stat
,
91 enum mem_cgroup_stat_index idx
)
95 for_each_possible_cpu(cpu
)
96 ret
+= stat
->cpustat
[cpu
].count
[idx
];
100 static s64
mem_cgroup_local_usage(struct mem_cgroup_stat
*stat
)
104 ret
= mem_cgroup_read_stat(stat
, MEM_CGROUP_STAT_CACHE
);
105 ret
+= mem_cgroup_read_stat(stat
, MEM_CGROUP_STAT_RSS
);
110 * per-zone information in memory controller.
112 struct mem_cgroup_per_zone
{
114 * spin_lock to protect the per cgroup LRU
116 struct list_head lists
[NR_LRU_LISTS
];
117 unsigned long count
[NR_LRU_LISTS
];
119 struct zone_reclaim_stat reclaim_stat
;
121 /* Macro for accessing counter */
122 #define MEM_CGROUP_ZSTAT(mz, idx) ((mz)->count[(idx)])
124 struct mem_cgroup_per_node
{
125 struct mem_cgroup_per_zone zoneinfo
[MAX_NR_ZONES
];
128 struct mem_cgroup_lru_info
{
129 struct mem_cgroup_per_node
*nodeinfo
[MAX_NUMNODES
];
133 * The memory controller data structure. The memory controller controls both
134 * page cache and RSS per cgroup. We would eventually like to provide
135 * statistics based on the statistics developed by Rik Van Riel for clock-pro,
136 * to help the administrator determine what knobs to tune.
138 * TODO: Add a water mark for the memory controller. Reclaim will begin when
139 * we hit the water mark. May be even add a low water mark, such that
140 * no reclaim occurs from a cgroup at it's low water mark, this is
141 * a feature that will be implemented much later in the future.
144 struct cgroup_subsys_state css
;
146 * the counter to account for memory usage
148 struct res_counter res
;
150 * the counter to account for mem+swap usage.
152 struct res_counter memsw
;
154 * Per cgroup active and inactive list, similar to the
155 * per zone LRU lists.
157 struct mem_cgroup_lru_info info
;
160 protect against reclaim related member.
162 spinlock_t reclaim_param_lock
;
164 int prev_priority
; /* for recording reclaim priority */
167 * While reclaiming in a hiearchy, we cache the last child we
170 int last_scanned_child
;
172 * Should the accounting and control be hierarchical, per subtree?
175 unsigned long last_oom_jiffies
;
178 unsigned int swappiness
;
180 /* set when res.limit == memsw.limit */
181 bool memsw_is_minimum
;
184 * statistics. This must be placed at the end of memcg.
186 struct mem_cgroup_stat stat
;
190 MEM_CGROUP_CHARGE_TYPE_CACHE
= 0,
191 MEM_CGROUP_CHARGE_TYPE_MAPPED
,
192 MEM_CGROUP_CHARGE_TYPE_SHMEM
, /* used by page migration of shmem */
193 MEM_CGROUP_CHARGE_TYPE_FORCE
, /* used by force_empty */
194 MEM_CGROUP_CHARGE_TYPE_SWAPOUT
, /* for accounting swapcache */
195 MEM_CGROUP_CHARGE_TYPE_DROP
, /* a page was unused swap cache */
199 /* only for here (for easy reading.) */
200 #define PCGF_CACHE (1UL << PCG_CACHE)
201 #define PCGF_USED (1UL << PCG_USED)
202 #define PCGF_LOCK (1UL << PCG_LOCK)
203 static const unsigned long
204 pcg_default_flags
[NR_CHARGE_TYPE
] = {
205 PCGF_CACHE
| PCGF_USED
| PCGF_LOCK
, /* File Cache */
206 PCGF_USED
| PCGF_LOCK
, /* Anon */
207 PCGF_CACHE
| PCGF_USED
| PCGF_LOCK
, /* Shmem */
211 /* for encoding cft->private value on file */
214 #define MEMFILE_PRIVATE(x, val) (((x) << 16) | (val))
215 #define MEMFILE_TYPE(val) (((val) >> 16) & 0xffff)
216 #define MEMFILE_ATTR(val) ((val) & 0xffff)
218 static void mem_cgroup_get(struct mem_cgroup
*mem
);
219 static void mem_cgroup_put(struct mem_cgroup
*mem
);
220 static struct mem_cgroup
*parent_mem_cgroup(struct mem_cgroup
*mem
);
222 static void mem_cgroup_charge_statistics(struct mem_cgroup
*mem
,
223 struct page_cgroup
*pc
,
226 int val
= (charge
)? 1 : -1;
227 struct mem_cgroup_stat
*stat
= &mem
->stat
;
228 struct mem_cgroup_stat_cpu
*cpustat
;
231 cpustat
= &stat
->cpustat
[cpu
];
232 if (PageCgroupCache(pc
))
233 __mem_cgroup_stat_add_safe(cpustat
, MEM_CGROUP_STAT_CACHE
, val
);
235 __mem_cgroup_stat_add_safe(cpustat
, MEM_CGROUP_STAT_RSS
, val
);
238 __mem_cgroup_stat_add_safe(cpustat
,
239 MEM_CGROUP_STAT_PGPGIN_COUNT
, 1);
241 __mem_cgroup_stat_add_safe(cpustat
,
242 MEM_CGROUP_STAT_PGPGOUT_COUNT
, 1);
246 static struct mem_cgroup_per_zone
*
247 mem_cgroup_zoneinfo(struct mem_cgroup
*mem
, int nid
, int zid
)
249 return &mem
->info
.nodeinfo
[nid
]->zoneinfo
[zid
];
252 static struct mem_cgroup_per_zone
*
253 page_cgroup_zoneinfo(struct page_cgroup
*pc
)
255 struct mem_cgroup
*mem
= pc
->mem_cgroup
;
256 int nid
= page_cgroup_nid(pc
);
257 int zid
= page_cgroup_zid(pc
);
262 return mem_cgroup_zoneinfo(mem
, nid
, zid
);
265 static unsigned long mem_cgroup_get_local_zonestat(struct mem_cgroup
*mem
,
269 struct mem_cgroup_per_zone
*mz
;
272 for_each_online_node(nid
)
273 for (zid
= 0; zid
< MAX_NR_ZONES
; zid
++) {
274 mz
= mem_cgroup_zoneinfo(mem
, nid
, zid
);
275 total
+= MEM_CGROUP_ZSTAT(mz
, idx
);
280 static struct mem_cgroup
*mem_cgroup_from_cont(struct cgroup
*cont
)
282 return container_of(cgroup_subsys_state(cont
,
283 mem_cgroup_subsys_id
), struct mem_cgroup
,
287 struct mem_cgroup
*mem_cgroup_from_task(struct task_struct
*p
)
290 * mm_update_next_owner() may clear mm->owner to NULL
291 * if it races with swapoff, page migration, etc.
292 * So this can be called with p == NULL.
297 return container_of(task_subsys_state(p
, mem_cgroup_subsys_id
),
298 struct mem_cgroup
, css
);
301 static struct mem_cgroup
*try_get_mem_cgroup_from_mm(struct mm_struct
*mm
)
303 struct mem_cgroup
*mem
= NULL
;
308 * Because we have no locks, mm->owner's may be being moved to other
309 * cgroup. We use css_tryget() here even if this looks
310 * pessimistic (rather than adding locks here).
314 mem
= mem_cgroup_from_task(rcu_dereference(mm
->owner
));
317 } while (!css_tryget(&mem
->css
));
323 * Call callback function against all cgroup under hierarchy tree.
325 static int mem_cgroup_walk_tree(struct mem_cgroup
*root
, void *data
,
326 int (*func
)(struct mem_cgroup
*, void *))
328 int found
, ret
, nextid
;
329 struct cgroup_subsys_state
*css
;
330 struct mem_cgroup
*mem
;
332 if (!root
->use_hierarchy
)
333 return (*func
)(root
, data
);
341 css
= css_get_next(&mem_cgroup_subsys
, nextid
, &root
->css
,
343 if (css
&& css_tryget(css
))
344 mem
= container_of(css
, struct mem_cgroup
, css
);
348 ret
= (*func
)(mem
, data
);
352 } while (!ret
&& css
);
358 * Following LRU functions are allowed to be used without PCG_LOCK.
359 * Operations are called by routine of global LRU independently from memcg.
360 * What we have to take care of here is validness of pc->mem_cgroup.
362 * Changes to pc->mem_cgroup happens when
365 * In typical case, "charge" is done before add-to-lru. Exception is SwapCache.
366 * It is added to LRU before charge.
367 * If PCG_USED bit is not set, page_cgroup is not added to this private LRU.
368 * When moving account, the page is not on LRU. It's isolated.
371 void mem_cgroup_del_lru_list(struct page
*page
, enum lru_list lru
)
373 struct page_cgroup
*pc
;
374 struct mem_cgroup
*mem
;
375 struct mem_cgroup_per_zone
*mz
;
377 if (mem_cgroup_disabled())
379 pc
= lookup_page_cgroup(page
);
380 /* can happen while we handle swapcache. */
381 if (list_empty(&pc
->lru
) || !pc
->mem_cgroup
)
384 * We don't check PCG_USED bit. It's cleared when the "page" is finally
385 * removed from global LRU.
387 mz
= page_cgroup_zoneinfo(pc
);
388 mem
= pc
->mem_cgroup
;
389 MEM_CGROUP_ZSTAT(mz
, lru
) -= 1;
390 list_del_init(&pc
->lru
);
394 void mem_cgroup_del_lru(struct page
*page
)
396 mem_cgroup_del_lru_list(page
, page_lru(page
));
399 void mem_cgroup_rotate_lru_list(struct page
*page
, enum lru_list lru
)
401 struct mem_cgroup_per_zone
*mz
;
402 struct page_cgroup
*pc
;
404 if (mem_cgroup_disabled())
407 pc
= lookup_page_cgroup(page
);
409 * Used bit is set without atomic ops but after smp_wmb().
410 * For making pc->mem_cgroup visible, insert smp_rmb() here.
413 /* unused page is not rotated. */
414 if (!PageCgroupUsed(pc
))
416 mz
= page_cgroup_zoneinfo(pc
);
417 list_move(&pc
->lru
, &mz
->lists
[lru
]);
420 void mem_cgroup_add_lru_list(struct page
*page
, enum lru_list lru
)
422 struct page_cgroup
*pc
;
423 struct mem_cgroup_per_zone
*mz
;
425 if (mem_cgroup_disabled())
427 pc
= lookup_page_cgroup(page
);
429 * Used bit is set without atomic ops but after smp_wmb().
430 * For making pc->mem_cgroup visible, insert smp_rmb() here.
433 if (!PageCgroupUsed(pc
))
436 mz
= page_cgroup_zoneinfo(pc
);
437 MEM_CGROUP_ZSTAT(mz
, lru
) += 1;
438 list_add(&pc
->lru
, &mz
->lists
[lru
]);
442 * At handling SwapCache, pc->mem_cgroup may be changed while it's linked to
443 * lru because the page may.be reused after it's fully uncharged (because of
444 * SwapCache behavior).To handle that, unlink page_cgroup from LRU when charge
445 * it again. This function is only used to charge SwapCache. It's done under
446 * lock_page and expected that zone->lru_lock is never held.
448 static void mem_cgroup_lru_del_before_commit_swapcache(struct page
*page
)
451 struct zone
*zone
= page_zone(page
);
452 struct page_cgroup
*pc
= lookup_page_cgroup(page
);
454 spin_lock_irqsave(&zone
->lru_lock
, flags
);
456 * Forget old LRU when this page_cgroup is *not* used. This Used bit
457 * is guarded by lock_page() because the page is SwapCache.
459 if (!PageCgroupUsed(pc
))
460 mem_cgroup_del_lru_list(page
, page_lru(page
));
461 spin_unlock_irqrestore(&zone
->lru_lock
, flags
);
464 static void mem_cgroup_lru_add_after_commit_swapcache(struct page
*page
)
467 struct zone
*zone
= page_zone(page
);
468 struct page_cgroup
*pc
= lookup_page_cgroup(page
);
470 spin_lock_irqsave(&zone
->lru_lock
, flags
);
471 /* link when the page is linked to LRU but page_cgroup isn't */
472 if (PageLRU(page
) && list_empty(&pc
->lru
))
473 mem_cgroup_add_lru_list(page
, page_lru(page
));
474 spin_unlock_irqrestore(&zone
->lru_lock
, flags
);
478 void mem_cgroup_move_lists(struct page
*page
,
479 enum lru_list from
, enum lru_list to
)
481 if (mem_cgroup_disabled())
483 mem_cgroup_del_lru_list(page
, from
);
484 mem_cgroup_add_lru_list(page
, to
);
487 int task_in_mem_cgroup(struct task_struct
*task
, const struct mem_cgroup
*mem
)
490 struct mem_cgroup
*curr
= NULL
;
494 curr
= try_get_mem_cgroup_from_mm(task
->mm
);
499 if (curr
->use_hierarchy
)
500 ret
= css_is_ancestor(&curr
->css
, &mem
->css
);
508 * prev_priority control...this will be used in memory reclaim path.
510 int mem_cgroup_get_reclaim_priority(struct mem_cgroup
*mem
)
514 spin_lock(&mem
->reclaim_param_lock
);
515 prev_priority
= mem
->prev_priority
;
516 spin_unlock(&mem
->reclaim_param_lock
);
518 return prev_priority
;
521 void mem_cgroup_note_reclaim_priority(struct mem_cgroup
*mem
, int priority
)
523 spin_lock(&mem
->reclaim_param_lock
);
524 if (priority
< mem
->prev_priority
)
525 mem
->prev_priority
= priority
;
526 spin_unlock(&mem
->reclaim_param_lock
);
529 void mem_cgroup_record_reclaim_priority(struct mem_cgroup
*mem
, int priority
)
531 spin_lock(&mem
->reclaim_param_lock
);
532 mem
->prev_priority
= priority
;
533 spin_unlock(&mem
->reclaim_param_lock
);
536 static int calc_inactive_ratio(struct mem_cgroup
*memcg
, unsigned long *present_pages
)
538 unsigned long active
;
539 unsigned long inactive
;
541 unsigned long inactive_ratio
;
543 inactive
= mem_cgroup_get_local_zonestat(memcg
, LRU_INACTIVE_ANON
);
544 active
= mem_cgroup_get_local_zonestat(memcg
, LRU_ACTIVE_ANON
);
546 gb
= (inactive
+ active
) >> (30 - PAGE_SHIFT
);
548 inactive_ratio
= int_sqrt(10 * gb
);
553 present_pages
[0] = inactive
;
554 present_pages
[1] = active
;
557 return inactive_ratio
;
560 int mem_cgroup_inactive_anon_is_low(struct mem_cgroup
*memcg
)
562 unsigned long active
;
563 unsigned long inactive
;
564 unsigned long present_pages
[2];
565 unsigned long inactive_ratio
;
567 inactive_ratio
= calc_inactive_ratio(memcg
, present_pages
);
569 inactive
= present_pages
[0];
570 active
= present_pages
[1];
572 if (inactive
* inactive_ratio
< active
)
578 int mem_cgroup_inactive_file_is_low(struct mem_cgroup
*memcg
)
580 unsigned long active
;
581 unsigned long inactive
;
583 inactive
= mem_cgroup_get_local_zonestat(memcg
, LRU_INACTIVE_FILE
);
584 active
= mem_cgroup_get_local_zonestat(memcg
, LRU_ACTIVE_FILE
);
586 return (active
> inactive
);
589 unsigned long mem_cgroup_zone_nr_pages(struct mem_cgroup
*memcg
,
593 int nid
= zone
->zone_pgdat
->node_id
;
594 int zid
= zone_idx(zone
);
595 struct mem_cgroup_per_zone
*mz
= mem_cgroup_zoneinfo(memcg
, nid
, zid
);
597 return MEM_CGROUP_ZSTAT(mz
, lru
);
600 struct zone_reclaim_stat
*mem_cgroup_get_reclaim_stat(struct mem_cgroup
*memcg
,
603 int nid
= zone
->zone_pgdat
->node_id
;
604 int zid
= zone_idx(zone
);
605 struct mem_cgroup_per_zone
*mz
= mem_cgroup_zoneinfo(memcg
, nid
, zid
);
607 return &mz
->reclaim_stat
;
610 struct zone_reclaim_stat
*
611 mem_cgroup_get_reclaim_stat_from_page(struct page
*page
)
613 struct page_cgroup
*pc
;
614 struct mem_cgroup_per_zone
*mz
;
616 if (mem_cgroup_disabled())
619 pc
= lookup_page_cgroup(page
);
621 * Used bit is set without atomic ops but after smp_wmb().
622 * For making pc->mem_cgroup visible, insert smp_rmb() here.
625 if (!PageCgroupUsed(pc
))
628 mz
= page_cgroup_zoneinfo(pc
);
632 return &mz
->reclaim_stat
;
635 unsigned long mem_cgroup_isolate_pages(unsigned long nr_to_scan
,
636 struct list_head
*dst
,
637 unsigned long *scanned
, int order
,
638 int mode
, struct zone
*z
,
639 struct mem_cgroup
*mem_cont
,
640 int active
, int file
)
642 unsigned long nr_taken
= 0;
646 struct list_head
*src
;
647 struct page_cgroup
*pc
, *tmp
;
648 int nid
= z
->zone_pgdat
->node_id
;
649 int zid
= zone_idx(z
);
650 struct mem_cgroup_per_zone
*mz
;
651 int lru
= LRU_FILE
* !!file
+ !!active
;
654 mz
= mem_cgroup_zoneinfo(mem_cont
, nid
, zid
);
655 src
= &mz
->lists
[lru
];
658 list_for_each_entry_safe_reverse(pc
, tmp
, src
, lru
) {
659 if (scan
>= nr_to_scan
)
663 if (unlikely(!PageCgroupUsed(pc
)))
665 if (unlikely(!PageLRU(page
)))
669 if (__isolate_lru_page(page
, mode
, file
) == 0) {
670 list_move(&page
->lru
, dst
);
679 #define mem_cgroup_from_res_counter(counter, member) \
680 container_of(counter, struct mem_cgroup, member)
682 static bool mem_cgroup_check_under_limit(struct mem_cgroup
*mem
)
684 if (do_swap_account
) {
685 if (res_counter_check_under_limit(&mem
->res
) &&
686 res_counter_check_under_limit(&mem
->memsw
))
689 if (res_counter_check_under_limit(&mem
->res
))
694 static unsigned int get_swappiness(struct mem_cgroup
*memcg
)
696 struct cgroup
*cgrp
= memcg
->css
.cgroup
;
697 unsigned int swappiness
;
700 if (cgrp
->parent
== NULL
)
701 return vm_swappiness
;
703 spin_lock(&memcg
->reclaim_param_lock
);
704 swappiness
= memcg
->swappiness
;
705 spin_unlock(&memcg
->reclaim_param_lock
);
710 static int mem_cgroup_count_children_cb(struct mem_cgroup
*mem
, void *data
)
718 * mem_cgroup_print_mem_info: Called from OOM with tasklist_lock held in read mode.
719 * @memcg: The memory cgroup that went over limit
720 * @p: Task that is going to be killed
722 * NOTE: @memcg and @p's mem_cgroup can be different when hierarchy is
725 void mem_cgroup_print_oom_info(struct mem_cgroup
*memcg
, struct task_struct
*p
)
727 struct cgroup
*task_cgrp
;
728 struct cgroup
*mem_cgrp
;
730 * Need a buffer in BSS, can't rely on allocations. The code relies
731 * on the assumption that OOM is serialized for memory controller.
732 * If this assumption is broken, revisit this code.
734 static char memcg_name
[PATH_MAX
];
743 mem_cgrp
= memcg
->css
.cgroup
;
744 task_cgrp
= task_cgroup(p
, mem_cgroup_subsys_id
);
746 ret
= cgroup_path(task_cgrp
, memcg_name
, PATH_MAX
);
749 * Unfortunately, we are unable to convert to a useful name
750 * But we'll still print out the usage information
757 printk(KERN_INFO
"Task in %s killed", memcg_name
);
760 ret
= cgroup_path(mem_cgrp
, memcg_name
, PATH_MAX
);
768 * Continues from above, so we don't need an KERN_ level
770 printk(KERN_CONT
" as a result of limit of %s\n", memcg_name
);
773 printk(KERN_INFO
"memory: usage %llukB, limit %llukB, failcnt %llu\n",
774 res_counter_read_u64(&memcg
->res
, RES_USAGE
) >> 10,
775 res_counter_read_u64(&memcg
->res
, RES_LIMIT
) >> 10,
776 res_counter_read_u64(&memcg
->res
, RES_FAILCNT
));
777 printk(KERN_INFO
"memory+swap: usage %llukB, limit %llukB, "
779 res_counter_read_u64(&memcg
->memsw
, RES_USAGE
) >> 10,
780 res_counter_read_u64(&memcg
->memsw
, RES_LIMIT
) >> 10,
781 res_counter_read_u64(&memcg
->memsw
, RES_FAILCNT
));
785 * This function returns the number of memcg under hierarchy tree. Returns
786 * 1(self count) if no children.
788 static int mem_cgroup_count_children(struct mem_cgroup
*mem
)
791 mem_cgroup_walk_tree(mem
, &num
, mem_cgroup_count_children_cb
);
796 * Visit the first child (need not be the first child as per the ordering
797 * of the cgroup list, since we track last_scanned_child) of @mem and use
798 * that to reclaim free pages from.
800 static struct mem_cgroup
*
801 mem_cgroup_select_victim(struct mem_cgroup
*root_mem
)
803 struct mem_cgroup
*ret
= NULL
;
804 struct cgroup_subsys_state
*css
;
807 if (!root_mem
->use_hierarchy
) {
808 css_get(&root_mem
->css
);
814 nextid
= root_mem
->last_scanned_child
+ 1;
815 css
= css_get_next(&mem_cgroup_subsys
, nextid
, &root_mem
->css
,
817 if (css
&& css_tryget(css
))
818 ret
= container_of(css
, struct mem_cgroup
, css
);
821 /* Updates scanning parameter */
822 spin_lock(&root_mem
->reclaim_param_lock
);
824 /* this means start scan from ID:1 */
825 root_mem
->last_scanned_child
= 0;
827 root_mem
->last_scanned_child
= found
;
828 spin_unlock(&root_mem
->reclaim_param_lock
);
835 * Scan the hierarchy if needed to reclaim memory. We remember the last child
836 * we reclaimed from, so that we don't end up penalizing one child extensively
837 * based on its position in the children list.
839 * root_mem is the original ancestor that we've been reclaim from.
841 * We give up and return to the caller when we visit root_mem twice.
842 * (other groups can be removed while we're walking....)
844 * If shrink==true, for avoiding to free too much, this returns immedieately.
846 static int mem_cgroup_hierarchical_reclaim(struct mem_cgroup
*root_mem
,
847 gfp_t gfp_mask
, bool noswap
, bool shrink
)
849 struct mem_cgroup
*victim
;
853 /* If memsw_is_minimum==1, swap-out is of-no-use. */
854 if (root_mem
->memsw_is_minimum
)
858 victim
= mem_cgroup_select_victim(root_mem
);
859 if (victim
== root_mem
)
861 if (!mem_cgroup_local_usage(&victim
->stat
)) {
862 /* this cgroup's local usage == 0 */
863 css_put(&victim
->css
);
866 /* we use swappiness of local cgroup */
867 ret
= try_to_free_mem_cgroup_pages(victim
, gfp_mask
, noswap
,
868 get_swappiness(victim
));
869 css_put(&victim
->css
);
871 * At shrinking usage, we can't check we should stop here or
872 * reclaim more. It's depends on callers. last_scanned_child
873 * will work enough for keeping fairness under tree.
878 if (mem_cgroup_check_under_limit(root_mem
))
884 bool mem_cgroup_oom_called(struct task_struct
*task
)
887 struct mem_cgroup
*mem
;
888 struct mm_struct
*mm
;
894 mem
= mem_cgroup_from_task(rcu_dereference(mm
->owner
));
895 if (mem
&& time_before(jiffies
, mem
->last_oom_jiffies
+ HZ
/10))
901 static int record_last_oom_cb(struct mem_cgroup
*mem
, void *data
)
903 mem
->last_oom_jiffies
= jiffies
;
907 static void record_last_oom(struct mem_cgroup
*mem
)
909 mem_cgroup_walk_tree(mem
, NULL
, record_last_oom_cb
);
913 * Currently used to update mapped file statistics, but the routine can be
914 * generalized to update other statistics as well.
916 void mem_cgroup_update_mapped_file_stat(struct page
*page
, int val
)
918 struct mem_cgroup
*mem
;
919 struct mem_cgroup_stat
*stat
;
920 struct mem_cgroup_stat_cpu
*cpustat
;
922 struct page_cgroup
*pc
;
924 if (!page_is_file_cache(page
))
927 pc
= lookup_page_cgroup(page
);
931 lock_page_cgroup(pc
);
932 mem
= pc
->mem_cgroup
;
936 if (!PageCgroupUsed(pc
))
940 * Preemption is already disabled, we don't need get_cpu()
942 cpu
= smp_processor_id();
944 cpustat
= &stat
->cpustat
[cpu
];
946 __mem_cgroup_stat_add_safe(cpustat
, MEM_CGROUP_STAT_MAPPED_FILE
, val
);
948 unlock_page_cgroup(pc
);
952 * Unlike exported interface, "oom" parameter is added. if oom==true,
953 * oom-killer can be invoked.
955 static int __mem_cgroup_try_charge(struct mm_struct
*mm
,
956 gfp_t gfp_mask
, struct mem_cgroup
**memcg
,
959 struct mem_cgroup
*mem
, *mem_over_limit
;
960 int nr_retries
= MEM_CGROUP_RECLAIM_RETRIES
;
961 struct res_counter
*fail_res
;
963 if (unlikely(test_thread_flag(TIF_MEMDIE
))) {
964 /* Don't account this! */
970 * We always charge the cgroup the mm_struct belongs to.
971 * The mm_struct's mem_cgroup changes on task migration if the
972 * thread group leader migrates. It's possible that mm is not
973 * set, if so charge the init_mm (happens for pagecache usage).
977 mem
= try_get_mem_cgroup_from_mm(mm
);
985 VM_BUG_ON(css_is_removed(&mem
->css
));
991 ret
= res_counter_charge(&mem
->res
, PAGE_SIZE
, &fail_res
);
993 if (!do_swap_account
)
995 ret
= res_counter_charge(&mem
->memsw
, PAGE_SIZE
,
999 /* mem+swap counter fails */
1000 res_counter_uncharge(&mem
->res
, PAGE_SIZE
);
1002 mem_over_limit
= mem_cgroup_from_res_counter(fail_res
,
1005 /* mem counter fails */
1006 mem_over_limit
= mem_cgroup_from_res_counter(fail_res
,
1009 if (!(gfp_mask
& __GFP_WAIT
))
1012 ret
= mem_cgroup_hierarchical_reclaim(mem_over_limit
, gfp_mask
,
1018 * try_to_free_mem_cgroup_pages() might not give us a full
1019 * picture of reclaim. Some pages are reclaimed and might be
1020 * moved to swap cache or just unmapped from the cgroup.
1021 * Check the limit again to see if the reclaim reduced the
1022 * current usage of the cgroup before giving up
1025 if (mem_cgroup_check_under_limit(mem_over_limit
))
1028 if (!nr_retries
--) {
1030 mutex_lock(&memcg_tasklist
);
1031 mem_cgroup_out_of_memory(mem_over_limit
, gfp_mask
);
1032 mutex_unlock(&memcg_tasklist
);
1033 record_last_oom(mem_over_limit
);
1046 * A helper function to get mem_cgroup from ID. must be called under
1047 * rcu_read_lock(). The caller must check css_is_removed() or some if
1048 * it's concern. (dropping refcnt from swap can be called against removed
1051 static struct mem_cgroup
*mem_cgroup_lookup(unsigned short id
)
1053 struct cgroup_subsys_state
*css
;
1055 /* ID 0 is unused ID */
1058 css
= css_lookup(&mem_cgroup_subsys
, id
);
1061 return container_of(css
, struct mem_cgroup
, css
);
1064 static struct mem_cgroup
*try_get_mem_cgroup_from_swapcache(struct page
*page
)
1066 struct mem_cgroup
*mem
;
1067 struct page_cgroup
*pc
;
1071 VM_BUG_ON(!PageLocked(page
));
1073 if (!PageSwapCache(page
))
1076 pc
= lookup_page_cgroup(page
);
1077 lock_page_cgroup(pc
);
1078 if (PageCgroupUsed(pc
)) {
1079 mem
= pc
->mem_cgroup
;
1080 if (mem
&& !css_tryget(&mem
->css
))
1083 ent
.val
= page_private(page
);
1084 id
= lookup_swap_cgroup(ent
);
1086 mem
= mem_cgroup_lookup(id
);
1087 if (mem
&& !css_tryget(&mem
->css
))
1091 unlock_page_cgroup(pc
);
1096 * commit a charge got by __mem_cgroup_try_charge() and makes page_cgroup to be
1097 * USED state. If already USED, uncharge and return.
1100 static void __mem_cgroup_commit_charge(struct mem_cgroup
*mem
,
1101 struct page_cgroup
*pc
,
1102 enum charge_type ctype
)
1104 /* try_charge() can return NULL to *memcg, taking care of it. */
1108 lock_page_cgroup(pc
);
1109 if (unlikely(PageCgroupUsed(pc
))) {
1110 unlock_page_cgroup(pc
);
1111 res_counter_uncharge(&mem
->res
, PAGE_SIZE
);
1112 if (do_swap_account
)
1113 res_counter_uncharge(&mem
->memsw
, PAGE_SIZE
);
1117 pc
->mem_cgroup
= mem
;
1119 pc
->flags
= pcg_default_flags
[ctype
];
1121 mem_cgroup_charge_statistics(mem
, pc
, true);
1123 unlock_page_cgroup(pc
);
1127 * mem_cgroup_move_account - move account of the page
1128 * @pc: page_cgroup of the page.
1129 * @from: mem_cgroup which the page is moved from.
1130 * @to: mem_cgroup which the page is moved to. @from != @to.
1132 * The caller must confirm following.
1133 * - page is not on LRU (isolate_page() is useful.)
1135 * returns 0 at success,
1136 * returns -EBUSY when lock is busy or "pc" is unstable.
1138 * This function does "uncharge" from old cgroup but doesn't do "charge" to
1139 * new cgroup. It should be done by a caller.
1142 static int mem_cgroup_move_account(struct page_cgroup
*pc
,
1143 struct mem_cgroup
*from
, struct mem_cgroup
*to
)
1145 struct mem_cgroup_per_zone
*from_mz
, *to_mz
;
1150 struct mem_cgroup_stat
*stat
;
1151 struct mem_cgroup_stat_cpu
*cpustat
;
1153 VM_BUG_ON(from
== to
);
1154 VM_BUG_ON(PageLRU(pc
->page
));
1156 nid
= page_cgroup_nid(pc
);
1157 zid
= page_cgroup_zid(pc
);
1158 from_mz
= mem_cgroup_zoneinfo(from
, nid
, zid
);
1159 to_mz
= mem_cgroup_zoneinfo(to
, nid
, zid
);
1161 if (!trylock_page_cgroup(pc
))
1164 if (!PageCgroupUsed(pc
))
1167 if (pc
->mem_cgroup
!= from
)
1170 res_counter_uncharge(&from
->res
, PAGE_SIZE
);
1171 mem_cgroup_charge_statistics(from
, pc
, false);
1174 if (page_is_file_cache(page
) && page_mapped(page
)) {
1175 cpu
= smp_processor_id();
1176 /* Update mapped_file data for mem_cgroup "from" */
1178 cpustat
= &stat
->cpustat
[cpu
];
1179 __mem_cgroup_stat_add_safe(cpustat
, MEM_CGROUP_STAT_MAPPED_FILE
,
1182 /* Update mapped_file data for mem_cgroup "to" */
1184 cpustat
= &stat
->cpustat
[cpu
];
1185 __mem_cgroup_stat_add_safe(cpustat
, MEM_CGROUP_STAT_MAPPED_FILE
,
1189 if (do_swap_account
)
1190 res_counter_uncharge(&from
->memsw
, PAGE_SIZE
);
1191 css_put(&from
->css
);
1194 pc
->mem_cgroup
= to
;
1195 mem_cgroup_charge_statistics(to
, pc
, true);
1198 unlock_page_cgroup(pc
);
1203 * move charges to its parent.
1206 static int mem_cgroup_move_parent(struct page_cgroup
*pc
,
1207 struct mem_cgroup
*child
,
1210 struct page
*page
= pc
->page
;
1211 struct cgroup
*cg
= child
->css
.cgroup
;
1212 struct cgroup
*pcg
= cg
->parent
;
1213 struct mem_cgroup
*parent
;
1221 parent
= mem_cgroup_from_cont(pcg
);
1224 ret
= __mem_cgroup_try_charge(NULL
, gfp_mask
, &parent
, false);
1228 if (!get_page_unless_zero(page
)) {
1233 ret
= isolate_lru_page(page
);
1238 ret
= mem_cgroup_move_account(pc
, child
, parent
);
1240 putback_lru_page(page
);
1243 /* drop extra refcnt by try_charge() */
1244 css_put(&parent
->css
);
1251 /* drop extra refcnt by try_charge() */
1252 css_put(&parent
->css
);
1253 /* uncharge if move fails */
1254 res_counter_uncharge(&parent
->res
, PAGE_SIZE
);
1255 if (do_swap_account
)
1256 res_counter_uncharge(&parent
->memsw
, PAGE_SIZE
);
1261 * Charge the memory controller for page usage.
1263 * 0 if the charge was successful
1264 * < 0 if the cgroup is over its limit
1266 static int mem_cgroup_charge_common(struct page
*page
, struct mm_struct
*mm
,
1267 gfp_t gfp_mask
, enum charge_type ctype
,
1268 struct mem_cgroup
*memcg
)
1270 struct mem_cgroup
*mem
;
1271 struct page_cgroup
*pc
;
1274 pc
= lookup_page_cgroup(page
);
1275 /* can happen at boot */
1281 ret
= __mem_cgroup_try_charge(mm
, gfp_mask
, &mem
, true);
1285 __mem_cgroup_commit_charge(mem
, pc
, ctype
);
1289 int mem_cgroup_newpage_charge(struct page
*page
,
1290 struct mm_struct
*mm
, gfp_t gfp_mask
)
1292 if (mem_cgroup_disabled())
1294 if (PageCompound(page
))
1297 * If already mapped, we don't have to account.
1298 * If page cache, page->mapping has address_space.
1299 * But page->mapping may have out-of-use anon_vma pointer,
1300 * detecit it by PageAnon() check. newly-mapped-anon's page->mapping
1303 if (page_mapped(page
) || (page
->mapping
&& !PageAnon(page
)))
1307 return mem_cgroup_charge_common(page
, mm
, gfp_mask
,
1308 MEM_CGROUP_CHARGE_TYPE_MAPPED
, NULL
);
1312 __mem_cgroup_commit_charge_swapin(struct page
*page
, struct mem_cgroup
*ptr
,
1313 enum charge_type ctype
);
1315 int mem_cgroup_cache_charge(struct page
*page
, struct mm_struct
*mm
,
1318 struct mem_cgroup
*mem
= NULL
;
1321 if (mem_cgroup_disabled())
1323 if (PageCompound(page
))
1326 * Corner case handling. This is called from add_to_page_cache()
1327 * in usual. But some FS (shmem) precharges this page before calling it
1328 * and call add_to_page_cache() with GFP_NOWAIT.
1330 * For GFP_NOWAIT case, the page may be pre-charged before calling
1331 * add_to_page_cache(). (See shmem.c) check it here and avoid to call
1332 * charge twice. (It works but has to pay a bit larger cost.)
1333 * And when the page is SwapCache, it should take swap information
1334 * into account. This is under lock_page() now.
1336 if (!(gfp_mask
& __GFP_WAIT
)) {
1337 struct page_cgroup
*pc
;
1340 pc
= lookup_page_cgroup(page
);
1343 lock_page_cgroup(pc
);
1344 if (PageCgroupUsed(pc
)) {
1345 unlock_page_cgroup(pc
);
1348 unlock_page_cgroup(pc
);
1351 if (unlikely(!mm
&& !mem
))
1354 if (page_is_file_cache(page
))
1355 return mem_cgroup_charge_common(page
, mm
, gfp_mask
,
1356 MEM_CGROUP_CHARGE_TYPE_CACHE
, NULL
);
1359 if (PageSwapCache(page
)) {
1360 ret
= mem_cgroup_try_charge_swapin(mm
, page
, gfp_mask
, &mem
);
1362 __mem_cgroup_commit_charge_swapin(page
, mem
,
1363 MEM_CGROUP_CHARGE_TYPE_SHMEM
);
1365 ret
= mem_cgroup_charge_common(page
, mm
, gfp_mask
,
1366 MEM_CGROUP_CHARGE_TYPE_SHMEM
, mem
);
1372 * While swap-in, try_charge -> commit or cancel, the page is locked.
1373 * And when try_charge() successfully returns, one refcnt to memcg without
1374 * struct page_cgroup is aquired. This refcnt will be cumsumed by
1375 * "commit()" or removed by "cancel()"
1377 int mem_cgroup_try_charge_swapin(struct mm_struct
*mm
,
1379 gfp_t mask
, struct mem_cgroup
**ptr
)
1381 struct mem_cgroup
*mem
;
1384 if (mem_cgroup_disabled())
1387 if (!do_swap_account
)
1390 * A racing thread's fault, or swapoff, may have already updated
1391 * the pte, and even removed page from swap cache: return success
1392 * to go on to do_swap_page()'s pte_same() test, which should fail.
1394 if (!PageSwapCache(page
))
1396 mem
= try_get_mem_cgroup_from_swapcache(page
);
1400 ret
= __mem_cgroup_try_charge(NULL
, mask
, ptr
, true);
1401 /* drop extra refcnt from tryget */
1407 return __mem_cgroup_try_charge(mm
, mask
, ptr
, true);
1411 __mem_cgroup_commit_charge_swapin(struct page
*page
, struct mem_cgroup
*ptr
,
1412 enum charge_type ctype
)
1414 struct page_cgroup
*pc
;
1416 if (mem_cgroup_disabled())
1420 pc
= lookup_page_cgroup(page
);
1421 mem_cgroup_lru_del_before_commit_swapcache(page
);
1422 __mem_cgroup_commit_charge(ptr
, pc
, ctype
);
1423 mem_cgroup_lru_add_after_commit_swapcache(page
);
1425 * Now swap is on-memory. This means this page may be
1426 * counted both as mem and swap....double count.
1427 * Fix it by uncharging from memsw. Basically, this SwapCache is stable
1428 * under lock_page(). But in do_swap_page()::memory.c, reuse_swap_page()
1429 * may call delete_from_swap_cache() before reach here.
1431 if (do_swap_account
&& PageSwapCache(page
)) {
1432 swp_entry_t ent
= {.val
= page_private(page
)};
1434 struct mem_cgroup
*memcg
;
1436 id
= swap_cgroup_record(ent
, 0);
1438 memcg
= mem_cgroup_lookup(id
);
1441 * This recorded memcg can be obsolete one. So, avoid
1442 * calling css_tryget
1444 res_counter_uncharge(&memcg
->memsw
, PAGE_SIZE
);
1445 mem_cgroup_put(memcg
);
1449 /* add this page(page_cgroup) to the LRU we want. */
1453 void mem_cgroup_commit_charge_swapin(struct page
*page
, struct mem_cgroup
*ptr
)
1455 __mem_cgroup_commit_charge_swapin(page
, ptr
,
1456 MEM_CGROUP_CHARGE_TYPE_MAPPED
);
1459 void mem_cgroup_cancel_charge_swapin(struct mem_cgroup
*mem
)
1461 if (mem_cgroup_disabled())
1465 res_counter_uncharge(&mem
->res
, PAGE_SIZE
);
1466 if (do_swap_account
)
1467 res_counter_uncharge(&mem
->memsw
, PAGE_SIZE
);
1473 * uncharge if !page_mapped(page)
1475 static struct mem_cgroup
*
1476 __mem_cgroup_uncharge_common(struct page
*page
, enum charge_type ctype
)
1478 struct page_cgroup
*pc
;
1479 struct mem_cgroup
*mem
= NULL
;
1480 struct mem_cgroup_per_zone
*mz
;
1482 if (mem_cgroup_disabled())
1485 if (PageSwapCache(page
))
1489 * Check if our page_cgroup is valid
1491 pc
= lookup_page_cgroup(page
);
1492 if (unlikely(!pc
|| !PageCgroupUsed(pc
)))
1495 lock_page_cgroup(pc
);
1497 mem
= pc
->mem_cgroup
;
1499 if (!PageCgroupUsed(pc
))
1503 case MEM_CGROUP_CHARGE_TYPE_MAPPED
:
1504 case MEM_CGROUP_CHARGE_TYPE_DROP
:
1505 if (page_mapped(page
))
1508 case MEM_CGROUP_CHARGE_TYPE_SWAPOUT
:
1509 if (!PageAnon(page
)) { /* Shared memory */
1510 if (page
->mapping
&& !page_is_file_cache(page
))
1512 } else if (page_mapped(page
)) /* Anon */
1519 res_counter_uncharge(&mem
->res
, PAGE_SIZE
);
1520 if (do_swap_account
&& (ctype
!= MEM_CGROUP_CHARGE_TYPE_SWAPOUT
))
1521 res_counter_uncharge(&mem
->memsw
, PAGE_SIZE
);
1522 mem_cgroup_charge_statistics(mem
, pc
, false);
1524 ClearPageCgroupUsed(pc
);
1526 * pc->mem_cgroup is not cleared here. It will be accessed when it's
1527 * freed from LRU. This is safe because uncharged page is expected not
1528 * to be reused (freed soon). Exception is SwapCache, it's handled by
1529 * special functions.
1532 mz
= page_cgroup_zoneinfo(pc
);
1533 unlock_page_cgroup(pc
);
1535 /* at swapout, this memcg will be accessed to record to swap */
1536 if (ctype
!= MEM_CGROUP_CHARGE_TYPE_SWAPOUT
)
1542 unlock_page_cgroup(pc
);
1546 void mem_cgroup_uncharge_page(struct page
*page
)
1549 if (page_mapped(page
))
1551 if (page
->mapping
&& !PageAnon(page
))
1553 __mem_cgroup_uncharge_common(page
, MEM_CGROUP_CHARGE_TYPE_MAPPED
);
1556 void mem_cgroup_uncharge_cache_page(struct page
*page
)
1558 VM_BUG_ON(page_mapped(page
));
1559 VM_BUG_ON(page
->mapping
);
1560 __mem_cgroup_uncharge_common(page
, MEM_CGROUP_CHARGE_TYPE_CACHE
);
1565 * called after __delete_from_swap_cache() and drop "page" account.
1566 * memcg information is recorded to swap_cgroup of "ent"
1569 mem_cgroup_uncharge_swapcache(struct page
*page
, swp_entry_t ent
, bool swapout
)
1571 struct mem_cgroup
*memcg
;
1572 int ctype
= MEM_CGROUP_CHARGE_TYPE_SWAPOUT
;
1574 if (!swapout
) /* this was a swap cache but the swap is unused ! */
1575 ctype
= MEM_CGROUP_CHARGE_TYPE_DROP
;
1577 memcg
= __mem_cgroup_uncharge_common(page
, ctype
);
1579 /* record memcg information */
1580 if (do_swap_account
&& swapout
&& memcg
) {
1581 swap_cgroup_record(ent
, css_id(&memcg
->css
));
1582 mem_cgroup_get(memcg
);
1584 if (swapout
&& memcg
)
1585 css_put(&memcg
->css
);
1589 #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP
1591 * called from swap_entry_free(). remove record in swap_cgroup and
1592 * uncharge "memsw" account.
1594 void mem_cgroup_uncharge_swap(swp_entry_t ent
)
1596 struct mem_cgroup
*memcg
;
1599 if (!do_swap_account
)
1602 id
= swap_cgroup_record(ent
, 0);
1604 memcg
= mem_cgroup_lookup(id
);
1607 * We uncharge this because swap is freed.
1608 * This memcg can be obsolete one. We avoid calling css_tryget
1610 res_counter_uncharge(&memcg
->memsw
, PAGE_SIZE
);
1611 mem_cgroup_put(memcg
);
1618 * Before starting migration, account PAGE_SIZE to mem_cgroup that the old
1621 int mem_cgroup_prepare_migration(struct page
*page
, struct mem_cgroup
**ptr
)
1623 struct page_cgroup
*pc
;
1624 struct mem_cgroup
*mem
= NULL
;
1627 if (mem_cgroup_disabled())
1630 pc
= lookup_page_cgroup(page
);
1631 lock_page_cgroup(pc
);
1632 if (PageCgroupUsed(pc
)) {
1633 mem
= pc
->mem_cgroup
;
1636 unlock_page_cgroup(pc
);
1639 ret
= __mem_cgroup_try_charge(NULL
, GFP_KERNEL
, &mem
, false);
1646 /* remove redundant charge if migration failed*/
1647 void mem_cgroup_end_migration(struct mem_cgroup
*mem
,
1648 struct page
*oldpage
, struct page
*newpage
)
1650 struct page
*target
, *unused
;
1651 struct page_cgroup
*pc
;
1652 enum charge_type ctype
;
1657 /* at migration success, oldpage->mapping is NULL. */
1658 if (oldpage
->mapping
) {
1666 if (PageAnon(target
))
1667 ctype
= MEM_CGROUP_CHARGE_TYPE_MAPPED
;
1668 else if (page_is_file_cache(target
))
1669 ctype
= MEM_CGROUP_CHARGE_TYPE_CACHE
;
1671 ctype
= MEM_CGROUP_CHARGE_TYPE_SHMEM
;
1673 /* unused page is not on radix-tree now. */
1675 __mem_cgroup_uncharge_common(unused
, ctype
);
1677 pc
= lookup_page_cgroup(target
);
1679 * __mem_cgroup_commit_charge() check PCG_USED bit of page_cgroup.
1680 * So, double-counting is effectively avoided.
1682 __mem_cgroup_commit_charge(mem
, pc
, ctype
);
1685 * Both of oldpage and newpage are still under lock_page().
1686 * Then, we don't have to care about race in radix-tree.
1687 * But we have to be careful that this page is unmapped or not.
1689 * There is a case for !page_mapped(). At the start of
1690 * migration, oldpage was mapped. But now, it's zapped.
1691 * But we know *target* page is not freed/reused under us.
1692 * mem_cgroup_uncharge_page() does all necessary checks.
1694 if (ctype
== MEM_CGROUP_CHARGE_TYPE_MAPPED
)
1695 mem_cgroup_uncharge_page(target
);
1699 * A call to try to shrink memory usage on charge failure at shmem's swapin.
1700 * Calling hierarchical_reclaim is not enough because we should update
1701 * last_oom_jiffies to prevent pagefault_out_of_memory from invoking global OOM.
1702 * Moreover considering hierarchy, we should reclaim from the mem_over_limit,
1703 * not from the memcg which this page would be charged to.
1704 * try_charge_swapin does all of these works properly.
1706 int mem_cgroup_shmem_charge_fallback(struct page
*page
,
1707 struct mm_struct
*mm
,
1710 struct mem_cgroup
*mem
= NULL
;
1713 if (mem_cgroup_disabled())
1716 ret
= mem_cgroup_try_charge_swapin(mm
, page
, gfp_mask
, &mem
);
1718 mem_cgroup_cancel_charge_swapin(mem
); /* it does !mem check */
1723 static DEFINE_MUTEX(set_limit_mutex
);
1725 static int mem_cgroup_resize_limit(struct mem_cgroup
*memcg
,
1726 unsigned long long val
)
1732 int children
= mem_cgroup_count_children(memcg
);
1733 u64 curusage
, oldusage
;
1736 * For keeping hierarchical_reclaim simple, how long we should retry
1737 * is depends on callers. We set our retry-count to be function
1738 * of # of children which we should visit in this loop.
1740 retry_count
= MEM_CGROUP_RECLAIM_RETRIES
* children
;
1742 oldusage
= res_counter_read_u64(&memcg
->res
, RES_USAGE
);
1744 while (retry_count
) {
1745 if (signal_pending(current
)) {
1750 * Rather than hide all in some function, I do this in
1751 * open coded manner. You see what this really does.
1752 * We have to guarantee mem->res.limit < mem->memsw.limit.
1754 mutex_lock(&set_limit_mutex
);
1755 memswlimit
= res_counter_read_u64(&memcg
->memsw
, RES_LIMIT
);
1756 if (memswlimit
< val
) {
1758 mutex_unlock(&set_limit_mutex
);
1761 ret
= res_counter_set_limit(&memcg
->res
, val
);
1763 if (memswlimit
== val
)
1764 memcg
->memsw_is_minimum
= true;
1766 memcg
->memsw_is_minimum
= false;
1768 mutex_unlock(&set_limit_mutex
);
1773 progress
= mem_cgroup_hierarchical_reclaim(memcg
, GFP_KERNEL
,
1775 curusage
= res_counter_read_u64(&memcg
->res
, RES_USAGE
);
1776 /* Usage is reduced ? */
1777 if (curusage
>= oldusage
)
1780 oldusage
= curusage
;
1786 static int mem_cgroup_resize_memsw_limit(struct mem_cgroup
*memcg
,
1787 unsigned long long val
)
1790 u64 memlimit
, oldusage
, curusage
;
1791 int children
= mem_cgroup_count_children(memcg
);
1794 /* see mem_cgroup_resize_res_limit */
1795 retry_count
= children
* MEM_CGROUP_RECLAIM_RETRIES
;
1796 oldusage
= res_counter_read_u64(&memcg
->memsw
, RES_USAGE
);
1797 while (retry_count
) {
1798 if (signal_pending(current
)) {
1803 * Rather than hide all in some function, I do this in
1804 * open coded manner. You see what this really does.
1805 * We have to guarantee mem->res.limit < mem->memsw.limit.
1807 mutex_lock(&set_limit_mutex
);
1808 memlimit
= res_counter_read_u64(&memcg
->res
, RES_LIMIT
);
1809 if (memlimit
> val
) {
1811 mutex_unlock(&set_limit_mutex
);
1814 ret
= res_counter_set_limit(&memcg
->memsw
, val
);
1816 if (memlimit
== val
)
1817 memcg
->memsw_is_minimum
= true;
1819 memcg
->memsw_is_minimum
= false;
1821 mutex_unlock(&set_limit_mutex
);
1826 mem_cgroup_hierarchical_reclaim(memcg
, GFP_KERNEL
, true, true);
1827 curusage
= res_counter_read_u64(&memcg
->memsw
, RES_USAGE
);
1828 /* Usage is reduced ? */
1829 if (curusage
>= oldusage
)
1832 oldusage
= curusage
;
1838 * This routine traverse page_cgroup in given list and drop them all.
1839 * *And* this routine doesn't reclaim page itself, just removes page_cgroup.
1841 static int mem_cgroup_force_empty_list(struct mem_cgroup
*mem
,
1842 int node
, int zid
, enum lru_list lru
)
1845 struct mem_cgroup_per_zone
*mz
;
1846 struct page_cgroup
*pc
, *busy
;
1847 unsigned long flags
, loop
;
1848 struct list_head
*list
;
1851 zone
= &NODE_DATA(node
)->node_zones
[zid
];
1852 mz
= mem_cgroup_zoneinfo(mem
, node
, zid
);
1853 list
= &mz
->lists
[lru
];
1855 loop
= MEM_CGROUP_ZSTAT(mz
, lru
);
1856 /* give some margin against EBUSY etc...*/
1861 spin_lock_irqsave(&zone
->lru_lock
, flags
);
1862 if (list_empty(list
)) {
1863 spin_unlock_irqrestore(&zone
->lru_lock
, flags
);
1866 pc
= list_entry(list
->prev
, struct page_cgroup
, lru
);
1868 list_move(&pc
->lru
, list
);
1870 spin_unlock_irqrestore(&zone
->lru_lock
, flags
);
1873 spin_unlock_irqrestore(&zone
->lru_lock
, flags
);
1875 ret
= mem_cgroup_move_parent(pc
, mem
, GFP_KERNEL
);
1879 if (ret
== -EBUSY
|| ret
== -EINVAL
) {
1880 /* found lock contention or "pc" is obsolete. */
1887 if (!ret
&& !list_empty(list
))
1893 * make mem_cgroup's charge to be 0 if there is no task.
1894 * This enables deleting this mem_cgroup.
1896 static int mem_cgroup_force_empty(struct mem_cgroup
*mem
, bool free_all
)
1899 int node
, zid
, shrink
;
1900 int nr_retries
= MEM_CGROUP_RECLAIM_RETRIES
;
1901 struct cgroup
*cgrp
= mem
->css
.cgroup
;
1906 /* should free all ? */
1910 while (mem
->res
.usage
> 0) {
1912 if (cgroup_task_count(cgrp
) || !list_empty(&cgrp
->children
))
1915 if (signal_pending(current
))
1917 /* This is for making all *used* pages to be on LRU. */
1918 lru_add_drain_all();
1920 for_each_node_state(node
, N_HIGH_MEMORY
) {
1921 for (zid
= 0; !ret
&& zid
< MAX_NR_ZONES
; zid
++) {
1924 ret
= mem_cgroup_force_empty_list(mem
,
1933 /* it seems parent cgroup doesn't have enough mem */
1944 /* returns EBUSY if there is a task or if we come here twice. */
1945 if (cgroup_task_count(cgrp
) || !list_empty(&cgrp
->children
) || shrink
) {
1949 /* we call try-to-free pages for make this cgroup empty */
1950 lru_add_drain_all();
1951 /* try to free all pages in this cgroup */
1953 while (nr_retries
&& mem
->res
.usage
> 0) {
1956 if (signal_pending(current
)) {
1960 progress
= try_to_free_mem_cgroup_pages(mem
, GFP_KERNEL
,
1961 false, get_swappiness(mem
));
1964 /* maybe some writeback is necessary */
1965 congestion_wait(WRITE
, HZ
/10);
1970 /* try move_account...there may be some *locked* pages. */
1977 int mem_cgroup_force_empty_write(struct cgroup
*cont
, unsigned int event
)
1979 return mem_cgroup_force_empty(mem_cgroup_from_cont(cont
), true);
1983 static u64
mem_cgroup_hierarchy_read(struct cgroup
*cont
, struct cftype
*cft
)
1985 return mem_cgroup_from_cont(cont
)->use_hierarchy
;
1988 static int mem_cgroup_hierarchy_write(struct cgroup
*cont
, struct cftype
*cft
,
1992 struct mem_cgroup
*mem
= mem_cgroup_from_cont(cont
);
1993 struct cgroup
*parent
= cont
->parent
;
1994 struct mem_cgroup
*parent_mem
= NULL
;
1997 parent_mem
= mem_cgroup_from_cont(parent
);
2001 * If parent's use_hiearchy is set, we can't make any modifications
2002 * in the child subtrees. If it is unset, then the change can
2003 * occur, provided the current cgroup has no children.
2005 * For the root cgroup, parent_mem is NULL, we allow value to be
2006 * set if there are no children.
2008 if ((!parent_mem
|| !parent_mem
->use_hierarchy
) &&
2009 (val
== 1 || val
== 0)) {
2010 if (list_empty(&cont
->children
))
2011 mem
->use_hierarchy
= val
;
2021 static u64
mem_cgroup_read(struct cgroup
*cont
, struct cftype
*cft
)
2023 struct mem_cgroup
*mem
= mem_cgroup_from_cont(cont
);
2027 type
= MEMFILE_TYPE(cft
->private);
2028 name
= MEMFILE_ATTR(cft
->private);
2031 val
= res_counter_read_u64(&mem
->res
, name
);
2034 val
= res_counter_read_u64(&mem
->memsw
, name
);
2043 * The user of this function is...
2046 static int mem_cgroup_write(struct cgroup
*cont
, struct cftype
*cft
,
2049 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cont
);
2051 unsigned long long val
;
2054 type
= MEMFILE_TYPE(cft
->private);
2055 name
= MEMFILE_ATTR(cft
->private);
2058 /* This function does all necessary parse...reuse it */
2059 ret
= res_counter_memparse_write_strategy(buffer
, &val
);
2063 ret
= mem_cgroup_resize_limit(memcg
, val
);
2065 ret
= mem_cgroup_resize_memsw_limit(memcg
, val
);
2068 ret
= -EINVAL
; /* should be BUG() ? */
2074 static void memcg_get_hierarchical_limit(struct mem_cgroup
*memcg
,
2075 unsigned long long *mem_limit
, unsigned long long *memsw_limit
)
2077 struct cgroup
*cgroup
;
2078 unsigned long long min_limit
, min_memsw_limit
, tmp
;
2080 min_limit
= res_counter_read_u64(&memcg
->res
, RES_LIMIT
);
2081 min_memsw_limit
= res_counter_read_u64(&memcg
->memsw
, RES_LIMIT
);
2082 cgroup
= memcg
->css
.cgroup
;
2083 if (!memcg
->use_hierarchy
)
2086 while (cgroup
->parent
) {
2087 cgroup
= cgroup
->parent
;
2088 memcg
= mem_cgroup_from_cont(cgroup
);
2089 if (!memcg
->use_hierarchy
)
2091 tmp
= res_counter_read_u64(&memcg
->res
, RES_LIMIT
);
2092 min_limit
= min(min_limit
, tmp
);
2093 tmp
= res_counter_read_u64(&memcg
->memsw
, RES_LIMIT
);
2094 min_memsw_limit
= min(min_memsw_limit
, tmp
);
2097 *mem_limit
= min_limit
;
2098 *memsw_limit
= min_memsw_limit
;
2102 static int mem_cgroup_reset(struct cgroup
*cont
, unsigned int event
)
2104 struct mem_cgroup
*mem
;
2107 mem
= mem_cgroup_from_cont(cont
);
2108 type
= MEMFILE_TYPE(event
);
2109 name
= MEMFILE_ATTR(event
);
2113 res_counter_reset_max(&mem
->res
);
2115 res_counter_reset_max(&mem
->memsw
);
2119 res_counter_reset_failcnt(&mem
->res
);
2121 res_counter_reset_failcnt(&mem
->memsw
);
2128 /* For read statistics */
2143 struct mcs_total_stat
{
2144 s64 stat
[NR_MCS_STAT
];
2150 } memcg_stat_strings
[NR_MCS_STAT
] = {
2151 {"cache", "total_cache"},
2152 {"rss", "total_rss"},
2153 {"mapped_file", "total_mapped_file"},
2154 {"pgpgin", "total_pgpgin"},
2155 {"pgpgout", "total_pgpgout"},
2156 {"inactive_anon", "total_inactive_anon"},
2157 {"active_anon", "total_active_anon"},
2158 {"inactive_file", "total_inactive_file"},
2159 {"active_file", "total_active_file"},
2160 {"unevictable", "total_unevictable"}
2164 static int mem_cgroup_get_local_stat(struct mem_cgroup
*mem
, void *data
)
2166 struct mcs_total_stat
*s
= data
;
2170 val
= mem_cgroup_read_stat(&mem
->stat
, MEM_CGROUP_STAT_CACHE
);
2171 s
->stat
[MCS_CACHE
] += val
* PAGE_SIZE
;
2172 val
= mem_cgroup_read_stat(&mem
->stat
, MEM_CGROUP_STAT_RSS
);
2173 s
->stat
[MCS_RSS
] += val
* PAGE_SIZE
;
2174 val
= mem_cgroup_read_stat(&mem
->stat
, MEM_CGROUP_STAT_MAPPED_FILE
);
2175 s
->stat
[MCS_MAPPED_FILE
] += val
* PAGE_SIZE
;
2176 val
= mem_cgroup_read_stat(&mem
->stat
, MEM_CGROUP_STAT_PGPGIN_COUNT
);
2177 s
->stat
[MCS_PGPGIN
] += val
;
2178 val
= mem_cgroup_read_stat(&mem
->stat
, MEM_CGROUP_STAT_PGPGOUT_COUNT
);
2179 s
->stat
[MCS_PGPGOUT
] += val
;
2182 val
= mem_cgroup_get_local_zonestat(mem
, LRU_INACTIVE_ANON
);
2183 s
->stat
[MCS_INACTIVE_ANON
] += val
* PAGE_SIZE
;
2184 val
= mem_cgroup_get_local_zonestat(mem
, LRU_ACTIVE_ANON
);
2185 s
->stat
[MCS_ACTIVE_ANON
] += val
* PAGE_SIZE
;
2186 val
= mem_cgroup_get_local_zonestat(mem
, LRU_INACTIVE_FILE
);
2187 s
->stat
[MCS_INACTIVE_FILE
] += val
* PAGE_SIZE
;
2188 val
= mem_cgroup_get_local_zonestat(mem
, LRU_ACTIVE_FILE
);
2189 s
->stat
[MCS_ACTIVE_FILE
] += val
* PAGE_SIZE
;
2190 val
= mem_cgroup_get_local_zonestat(mem
, LRU_UNEVICTABLE
);
2191 s
->stat
[MCS_UNEVICTABLE
] += val
* PAGE_SIZE
;
2196 mem_cgroup_get_total_stat(struct mem_cgroup
*mem
, struct mcs_total_stat
*s
)
2198 mem_cgroup_walk_tree(mem
, s
, mem_cgroup_get_local_stat
);
2201 static int mem_control_stat_show(struct cgroup
*cont
, struct cftype
*cft
,
2202 struct cgroup_map_cb
*cb
)
2204 struct mem_cgroup
*mem_cont
= mem_cgroup_from_cont(cont
);
2205 struct mcs_total_stat mystat
;
2208 memset(&mystat
, 0, sizeof(mystat
));
2209 mem_cgroup_get_local_stat(mem_cont
, &mystat
);
2211 for (i
= 0; i
< NR_MCS_STAT
; i
++)
2212 cb
->fill(cb
, memcg_stat_strings
[i
].local_name
, mystat
.stat
[i
]);
2214 /* Hierarchical information */
2216 unsigned long long limit
, memsw_limit
;
2217 memcg_get_hierarchical_limit(mem_cont
, &limit
, &memsw_limit
);
2218 cb
->fill(cb
, "hierarchical_memory_limit", limit
);
2219 if (do_swap_account
)
2220 cb
->fill(cb
, "hierarchical_memsw_limit", memsw_limit
);
2223 memset(&mystat
, 0, sizeof(mystat
));
2224 mem_cgroup_get_total_stat(mem_cont
, &mystat
);
2225 for (i
= 0; i
< NR_MCS_STAT
; i
++)
2226 cb
->fill(cb
, memcg_stat_strings
[i
].total_name
, mystat
.stat
[i
]);
2229 #ifdef CONFIG_DEBUG_VM
2230 cb
->fill(cb
, "inactive_ratio", calc_inactive_ratio(mem_cont
, NULL
));
2234 struct mem_cgroup_per_zone
*mz
;
2235 unsigned long recent_rotated
[2] = {0, 0};
2236 unsigned long recent_scanned
[2] = {0, 0};
2238 for_each_online_node(nid
)
2239 for (zid
= 0; zid
< MAX_NR_ZONES
; zid
++) {
2240 mz
= mem_cgroup_zoneinfo(mem_cont
, nid
, zid
);
2242 recent_rotated
[0] +=
2243 mz
->reclaim_stat
.recent_rotated
[0];
2244 recent_rotated
[1] +=
2245 mz
->reclaim_stat
.recent_rotated
[1];
2246 recent_scanned
[0] +=
2247 mz
->reclaim_stat
.recent_scanned
[0];
2248 recent_scanned
[1] +=
2249 mz
->reclaim_stat
.recent_scanned
[1];
2251 cb
->fill(cb
, "recent_rotated_anon", recent_rotated
[0]);
2252 cb
->fill(cb
, "recent_rotated_file", recent_rotated
[1]);
2253 cb
->fill(cb
, "recent_scanned_anon", recent_scanned
[0]);
2254 cb
->fill(cb
, "recent_scanned_file", recent_scanned
[1]);
2261 static u64
mem_cgroup_swappiness_read(struct cgroup
*cgrp
, struct cftype
*cft
)
2263 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cgrp
);
2265 return get_swappiness(memcg
);
2268 static int mem_cgroup_swappiness_write(struct cgroup
*cgrp
, struct cftype
*cft
,
2271 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cgrp
);
2272 struct mem_cgroup
*parent
;
2277 if (cgrp
->parent
== NULL
)
2280 parent
= mem_cgroup_from_cont(cgrp
->parent
);
2284 /* If under hierarchy, only empty-root can set this value */
2285 if ((parent
->use_hierarchy
) ||
2286 (memcg
->use_hierarchy
&& !list_empty(&cgrp
->children
))) {
2291 spin_lock(&memcg
->reclaim_param_lock
);
2292 memcg
->swappiness
= val
;
2293 spin_unlock(&memcg
->reclaim_param_lock
);
2301 static struct cftype mem_cgroup_files
[] = {
2303 .name
= "usage_in_bytes",
2304 .private = MEMFILE_PRIVATE(_MEM
, RES_USAGE
),
2305 .read_u64
= mem_cgroup_read
,
2308 .name
= "max_usage_in_bytes",
2309 .private = MEMFILE_PRIVATE(_MEM
, RES_MAX_USAGE
),
2310 .trigger
= mem_cgroup_reset
,
2311 .read_u64
= mem_cgroup_read
,
2314 .name
= "limit_in_bytes",
2315 .private = MEMFILE_PRIVATE(_MEM
, RES_LIMIT
),
2316 .write_string
= mem_cgroup_write
,
2317 .read_u64
= mem_cgroup_read
,
2321 .private = MEMFILE_PRIVATE(_MEM
, RES_FAILCNT
),
2322 .trigger
= mem_cgroup_reset
,
2323 .read_u64
= mem_cgroup_read
,
2327 .read_map
= mem_control_stat_show
,
2330 .name
= "force_empty",
2331 .trigger
= mem_cgroup_force_empty_write
,
2334 .name
= "use_hierarchy",
2335 .write_u64
= mem_cgroup_hierarchy_write
,
2336 .read_u64
= mem_cgroup_hierarchy_read
,
2339 .name
= "swappiness",
2340 .read_u64
= mem_cgroup_swappiness_read
,
2341 .write_u64
= mem_cgroup_swappiness_write
,
2345 #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP
2346 static struct cftype memsw_cgroup_files
[] = {
2348 .name
= "memsw.usage_in_bytes",
2349 .private = MEMFILE_PRIVATE(_MEMSWAP
, RES_USAGE
),
2350 .read_u64
= mem_cgroup_read
,
2353 .name
= "memsw.max_usage_in_bytes",
2354 .private = MEMFILE_PRIVATE(_MEMSWAP
, RES_MAX_USAGE
),
2355 .trigger
= mem_cgroup_reset
,
2356 .read_u64
= mem_cgroup_read
,
2359 .name
= "memsw.limit_in_bytes",
2360 .private = MEMFILE_PRIVATE(_MEMSWAP
, RES_LIMIT
),
2361 .write_string
= mem_cgroup_write
,
2362 .read_u64
= mem_cgroup_read
,
2365 .name
= "memsw.failcnt",
2366 .private = MEMFILE_PRIVATE(_MEMSWAP
, RES_FAILCNT
),
2367 .trigger
= mem_cgroup_reset
,
2368 .read_u64
= mem_cgroup_read
,
2372 static int register_memsw_files(struct cgroup
*cont
, struct cgroup_subsys
*ss
)
2374 if (!do_swap_account
)
2376 return cgroup_add_files(cont
, ss
, memsw_cgroup_files
,
2377 ARRAY_SIZE(memsw_cgroup_files
));
2380 static int register_memsw_files(struct cgroup
*cont
, struct cgroup_subsys
*ss
)
2386 static int alloc_mem_cgroup_per_zone_info(struct mem_cgroup
*mem
, int node
)
2388 struct mem_cgroup_per_node
*pn
;
2389 struct mem_cgroup_per_zone
*mz
;
2391 int zone
, tmp
= node
;
2393 * This routine is called against possible nodes.
2394 * But it's BUG to call kmalloc() against offline node.
2396 * TODO: this routine can waste much memory for nodes which will
2397 * never be onlined. It's better to use memory hotplug callback
2400 if (!node_state(node
, N_NORMAL_MEMORY
))
2402 pn
= kmalloc_node(sizeof(*pn
), GFP_KERNEL
, tmp
);
2406 mem
->info
.nodeinfo
[node
] = pn
;
2407 memset(pn
, 0, sizeof(*pn
));
2409 for (zone
= 0; zone
< MAX_NR_ZONES
; zone
++) {
2410 mz
= &pn
->zoneinfo
[zone
];
2412 INIT_LIST_HEAD(&mz
->lists
[l
]);
2417 static void free_mem_cgroup_per_zone_info(struct mem_cgroup
*mem
, int node
)
2419 kfree(mem
->info
.nodeinfo
[node
]);
2422 static int mem_cgroup_size(void)
2424 int cpustat_size
= nr_cpu_ids
* sizeof(struct mem_cgroup_stat_cpu
);
2425 return sizeof(struct mem_cgroup
) + cpustat_size
;
2428 static struct mem_cgroup
*mem_cgroup_alloc(void)
2430 struct mem_cgroup
*mem
;
2431 int size
= mem_cgroup_size();
2433 if (size
< PAGE_SIZE
)
2434 mem
= kmalloc(size
, GFP_KERNEL
);
2436 mem
= vmalloc(size
);
2439 memset(mem
, 0, size
);
2444 * At destroying mem_cgroup, references from swap_cgroup can remain.
2445 * (scanning all at force_empty is too costly...)
2447 * Instead of clearing all references at force_empty, we remember
2448 * the number of reference from swap_cgroup and free mem_cgroup when
2449 * it goes down to 0.
2451 * Removal of cgroup itself succeeds regardless of refs from swap.
2454 static void __mem_cgroup_free(struct mem_cgroup
*mem
)
2458 free_css_id(&mem_cgroup_subsys
, &mem
->css
);
2460 for_each_node_state(node
, N_POSSIBLE
)
2461 free_mem_cgroup_per_zone_info(mem
, node
);
2463 if (mem_cgroup_size() < PAGE_SIZE
)
2469 static void mem_cgroup_get(struct mem_cgroup
*mem
)
2471 atomic_inc(&mem
->refcnt
);
2474 static void mem_cgroup_put(struct mem_cgroup
*mem
)
2476 if (atomic_dec_and_test(&mem
->refcnt
)) {
2477 struct mem_cgroup
*parent
= parent_mem_cgroup(mem
);
2478 __mem_cgroup_free(mem
);
2480 mem_cgroup_put(parent
);
2485 * Returns the parent mem_cgroup in memcgroup hierarchy with hierarchy enabled.
2487 static struct mem_cgroup
*parent_mem_cgroup(struct mem_cgroup
*mem
)
2489 if (!mem
->res
.parent
)
2491 return mem_cgroup_from_res_counter(mem
->res
.parent
, res
);
2494 #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP
2495 static void __init
enable_swap_cgroup(void)
2497 if (!mem_cgroup_disabled() && really_do_swap_account
)
2498 do_swap_account
= 1;
2501 static void __init
enable_swap_cgroup(void)
2506 static struct cgroup_subsys_state
* __ref
2507 mem_cgroup_create(struct cgroup_subsys
*ss
, struct cgroup
*cont
)
2509 struct mem_cgroup
*mem
, *parent
;
2510 long error
= -ENOMEM
;
2513 mem
= mem_cgroup_alloc();
2515 return ERR_PTR(error
);
2517 for_each_node_state(node
, N_POSSIBLE
)
2518 if (alloc_mem_cgroup_per_zone_info(mem
, node
))
2521 if (cont
->parent
== NULL
) {
2522 enable_swap_cgroup();
2525 parent
= mem_cgroup_from_cont(cont
->parent
);
2526 mem
->use_hierarchy
= parent
->use_hierarchy
;
2529 if (parent
&& parent
->use_hierarchy
) {
2530 res_counter_init(&mem
->res
, &parent
->res
);
2531 res_counter_init(&mem
->memsw
, &parent
->memsw
);
2533 * We increment refcnt of the parent to ensure that we can
2534 * safely access it on res_counter_charge/uncharge.
2535 * This refcnt will be decremented when freeing this
2536 * mem_cgroup(see mem_cgroup_put).
2538 mem_cgroup_get(parent
);
2540 res_counter_init(&mem
->res
, NULL
);
2541 res_counter_init(&mem
->memsw
, NULL
);
2543 mem
->last_scanned_child
= 0;
2544 spin_lock_init(&mem
->reclaim_param_lock
);
2547 mem
->swappiness
= get_swappiness(parent
);
2548 atomic_set(&mem
->refcnt
, 1);
2551 __mem_cgroup_free(mem
);
2552 return ERR_PTR(error
);
2555 static int mem_cgroup_pre_destroy(struct cgroup_subsys
*ss
,
2556 struct cgroup
*cont
)
2558 struct mem_cgroup
*mem
= mem_cgroup_from_cont(cont
);
2560 return mem_cgroup_force_empty(mem
, false);
2563 static void mem_cgroup_destroy(struct cgroup_subsys
*ss
,
2564 struct cgroup
*cont
)
2566 struct mem_cgroup
*mem
= mem_cgroup_from_cont(cont
);
2568 mem_cgroup_put(mem
);
2571 static int mem_cgroup_populate(struct cgroup_subsys
*ss
,
2572 struct cgroup
*cont
)
2576 ret
= cgroup_add_files(cont
, ss
, mem_cgroup_files
,
2577 ARRAY_SIZE(mem_cgroup_files
));
2580 ret
= register_memsw_files(cont
, ss
);
2584 static void mem_cgroup_move_task(struct cgroup_subsys
*ss
,
2585 struct cgroup
*cont
,
2586 struct cgroup
*old_cont
,
2587 struct task_struct
*p
)
2589 mutex_lock(&memcg_tasklist
);
2591 * FIXME: It's better to move charges of this process from old
2592 * memcg to new memcg. But it's just on TODO-List now.
2594 mutex_unlock(&memcg_tasklist
);
2597 struct cgroup_subsys mem_cgroup_subsys
= {
2599 .subsys_id
= mem_cgroup_subsys_id
,
2600 .create
= mem_cgroup_create
,
2601 .pre_destroy
= mem_cgroup_pre_destroy
,
2602 .destroy
= mem_cgroup_destroy
,
2603 .populate
= mem_cgroup_populate
,
2604 .attach
= mem_cgroup_move_task
,
2609 #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP
2611 static int __init
disable_swap_account(char *s
)
2613 really_do_swap_account
= 0;
2616 __setup("noswapaccount", disable_swap_account
);