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/mutex.h>
31 #include <linux/slab.h>
32 #include <linux/swap.h>
33 #include <linux/spinlock.h>
35 #include <linux/seq_file.h>
36 #include <linux/vmalloc.h>
37 #include <linux/mm_inline.h>
38 #include <linux/page_cgroup.h>
41 #include <asm/uaccess.h>
43 struct cgroup_subsys mem_cgroup_subsys __read_mostly
;
44 #define MEM_CGROUP_RECLAIM_RETRIES 5
46 #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP
47 /* Turned on only when memory cgroup is enabled && really_do_swap_account = 0 */
48 int do_swap_account __read_mostly
;
49 static int really_do_swap_account __initdata
= 1; /* for remember boot option*/
51 #define do_swap_account (0)
54 static DEFINE_MUTEX(memcg_tasklist
); /* can be hold under cgroup_mutex */
57 * Statistics for memory cgroup.
59 enum mem_cgroup_stat_index
{
61 * For MEM_CONTAINER_TYPE_ALL, usage = pagecache + rss.
63 MEM_CGROUP_STAT_CACHE
, /* # of pages charged as cache */
64 MEM_CGROUP_STAT_RSS
, /* # of pages charged as rss */
65 MEM_CGROUP_STAT_PGPGIN_COUNT
, /* # of pages paged in */
66 MEM_CGROUP_STAT_PGPGOUT_COUNT
, /* # of pages paged out */
68 MEM_CGROUP_STAT_NSTATS
,
71 struct mem_cgroup_stat_cpu
{
72 s64 count
[MEM_CGROUP_STAT_NSTATS
];
73 } ____cacheline_aligned_in_smp
;
75 struct mem_cgroup_stat
{
76 struct mem_cgroup_stat_cpu cpustat
[0];
80 * For accounting under irq disable, no need for increment preempt count.
82 static inline void __mem_cgroup_stat_add_safe(struct mem_cgroup_stat_cpu
*stat
,
83 enum mem_cgroup_stat_index idx
, int val
)
85 stat
->count
[idx
] += val
;
88 static s64
mem_cgroup_read_stat(struct mem_cgroup_stat
*stat
,
89 enum mem_cgroup_stat_index idx
)
93 for_each_possible_cpu(cpu
)
94 ret
+= stat
->cpustat
[cpu
].count
[idx
];
98 static s64
mem_cgroup_local_usage(struct mem_cgroup_stat
*stat
)
102 ret
= mem_cgroup_read_stat(stat
, MEM_CGROUP_STAT_CACHE
);
103 ret
+= mem_cgroup_read_stat(stat
, MEM_CGROUP_STAT_RSS
);
108 * per-zone information in memory controller.
110 struct mem_cgroup_per_zone
{
112 * spin_lock to protect the per cgroup LRU
114 struct list_head lists
[NR_LRU_LISTS
];
115 unsigned long count
[NR_LRU_LISTS
];
117 struct zone_reclaim_stat reclaim_stat
;
119 /* Macro for accessing counter */
120 #define MEM_CGROUP_ZSTAT(mz, idx) ((mz)->count[(idx)])
122 struct mem_cgroup_per_node
{
123 struct mem_cgroup_per_zone zoneinfo
[MAX_NR_ZONES
];
126 struct mem_cgroup_lru_info
{
127 struct mem_cgroup_per_node
*nodeinfo
[MAX_NUMNODES
];
131 * The memory controller data structure. The memory controller controls both
132 * page cache and RSS per cgroup. We would eventually like to provide
133 * statistics based on the statistics developed by Rik Van Riel for clock-pro,
134 * to help the administrator determine what knobs to tune.
136 * TODO: Add a water mark for the memory controller. Reclaim will begin when
137 * we hit the water mark. May be even add a low water mark, such that
138 * no reclaim occurs from a cgroup at it's low water mark, this is
139 * a feature that will be implemented much later in the future.
142 struct cgroup_subsys_state css
;
144 * the counter to account for memory usage
146 struct res_counter res
;
148 * the counter to account for mem+swap usage.
150 struct res_counter memsw
;
152 * Per cgroup active and inactive list, similar to the
153 * per zone LRU lists.
155 struct mem_cgroup_lru_info info
;
158 protect against reclaim related member.
160 spinlock_t reclaim_param_lock
;
162 int prev_priority
; /* for recording reclaim priority */
165 * While reclaiming in a hiearchy, we cache the last child we
168 int last_scanned_child
;
170 * Should the accounting and control be hierarchical, per subtree?
173 unsigned long last_oom_jiffies
;
176 unsigned int swappiness
;
179 * statistics. This must be placed at the end of memcg.
181 struct mem_cgroup_stat stat
;
185 MEM_CGROUP_CHARGE_TYPE_CACHE
= 0,
186 MEM_CGROUP_CHARGE_TYPE_MAPPED
,
187 MEM_CGROUP_CHARGE_TYPE_SHMEM
, /* used by page migration of shmem */
188 MEM_CGROUP_CHARGE_TYPE_FORCE
, /* used by force_empty */
189 MEM_CGROUP_CHARGE_TYPE_SWAPOUT
, /* for accounting swapcache */
193 /* only for here (for easy reading.) */
194 #define PCGF_CACHE (1UL << PCG_CACHE)
195 #define PCGF_USED (1UL << PCG_USED)
196 #define PCGF_LOCK (1UL << PCG_LOCK)
197 static const unsigned long
198 pcg_default_flags
[NR_CHARGE_TYPE
] = {
199 PCGF_CACHE
| PCGF_USED
| PCGF_LOCK
, /* File Cache */
200 PCGF_USED
| PCGF_LOCK
, /* Anon */
201 PCGF_CACHE
| PCGF_USED
| PCGF_LOCK
, /* Shmem */
205 /* for encoding cft->private value on file */
208 #define MEMFILE_PRIVATE(x, val) (((x) << 16) | (val))
209 #define MEMFILE_TYPE(val) (((val) >> 16) & 0xffff)
210 #define MEMFILE_ATTR(val) ((val) & 0xffff)
212 static void mem_cgroup_get(struct mem_cgroup
*mem
);
213 static void mem_cgroup_put(struct mem_cgroup
*mem
);
214 static struct mem_cgroup
*parent_mem_cgroup(struct mem_cgroup
*mem
);
216 static void mem_cgroup_charge_statistics(struct mem_cgroup
*mem
,
217 struct page_cgroup
*pc
,
220 int val
= (charge
)? 1 : -1;
221 struct mem_cgroup_stat
*stat
= &mem
->stat
;
222 struct mem_cgroup_stat_cpu
*cpustat
;
225 cpustat
= &stat
->cpustat
[cpu
];
226 if (PageCgroupCache(pc
))
227 __mem_cgroup_stat_add_safe(cpustat
, MEM_CGROUP_STAT_CACHE
, val
);
229 __mem_cgroup_stat_add_safe(cpustat
, MEM_CGROUP_STAT_RSS
, val
);
232 __mem_cgroup_stat_add_safe(cpustat
,
233 MEM_CGROUP_STAT_PGPGIN_COUNT
, 1);
235 __mem_cgroup_stat_add_safe(cpustat
,
236 MEM_CGROUP_STAT_PGPGOUT_COUNT
, 1);
240 static struct mem_cgroup_per_zone
*
241 mem_cgroup_zoneinfo(struct mem_cgroup
*mem
, int nid
, int zid
)
243 return &mem
->info
.nodeinfo
[nid
]->zoneinfo
[zid
];
246 static struct mem_cgroup_per_zone
*
247 page_cgroup_zoneinfo(struct page_cgroup
*pc
)
249 struct mem_cgroup
*mem
= pc
->mem_cgroup
;
250 int nid
= page_cgroup_nid(pc
);
251 int zid
= page_cgroup_zid(pc
);
256 return mem_cgroup_zoneinfo(mem
, nid
, zid
);
259 static unsigned long mem_cgroup_get_all_zonestat(struct mem_cgroup
*mem
,
263 struct mem_cgroup_per_zone
*mz
;
266 for_each_online_node(nid
)
267 for (zid
= 0; zid
< MAX_NR_ZONES
; zid
++) {
268 mz
= mem_cgroup_zoneinfo(mem
, nid
, zid
);
269 total
+= MEM_CGROUP_ZSTAT(mz
, idx
);
274 static struct mem_cgroup
*mem_cgroup_from_cont(struct cgroup
*cont
)
276 return container_of(cgroup_subsys_state(cont
,
277 mem_cgroup_subsys_id
), struct mem_cgroup
,
281 struct mem_cgroup
*mem_cgroup_from_task(struct task_struct
*p
)
284 * mm_update_next_owner() may clear mm->owner to NULL
285 * if it races with swapoff, page migration, etc.
286 * So this can be called with p == NULL.
291 return container_of(task_subsys_state(p
, mem_cgroup_subsys_id
),
292 struct mem_cgroup
, css
);
295 static struct mem_cgroup
*try_get_mem_cgroup_from_mm(struct mm_struct
*mm
)
297 struct mem_cgroup
*mem
= NULL
;
299 * Because we have no locks, mm->owner's may be being moved to other
300 * cgroup. We use css_tryget() here even if this looks
301 * pessimistic (rather than adding locks here).
305 mem
= mem_cgroup_from_task(rcu_dereference(mm
->owner
));
308 } while (!css_tryget(&mem
->css
));
313 static bool mem_cgroup_is_obsolete(struct mem_cgroup
*mem
)
317 return css_is_removed(&mem
->css
);
321 * Following LRU functions are allowed to be used without PCG_LOCK.
322 * Operations are called by routine of global LRU independently from memcg.
323 * What we have to take care of here is validness of pc->mem_cgroup.
325 * Changes to pc->mem_cgroup happens when
328 * In typical case, "charge" is done before add-to-lru. Exception is SwapCache.
329 * It is added to LRU before charge.
330 * If PCG_USED bit is not set, page_cgroup is not added to this private LRU.
331 * When moving account, the page is not on LRU. It's isolated.
334 void mem_cgroup_del_lru_list(struct page
*page
, enum lru_list lru
)
336 struct page_cgroup
*pc
;
337 struct mem_cgroup
*mem
;
338 struct mem_cgroup_per_zone
*mz
;
340 if (mem_cgroup_disabled())
342 pc
= lookup_page_cgroup(page
);
343 /* can happen while we handle swapcache. */
344 if (list_empty(&pc
->lru
) || !pc
->mem_cgroup
)
347 * We don't check PCG_USED bit. It's cleared when the "page" is finally
348 * removed from global LRU.
350 mz
= page_cgroup_zoneinfo(pc
);
351 mem
= pc
->mem_cgroup
;
352 MEM_CGROUP_ZSTAT(mz
, lru
) -= 1;
353 list_del_init(&pc
->lru
);
357 void mem_cgroup_del_lru(struct page
*page
)
359 mem_cgroup_del_lru_list(page
, page_lru(page
));
362 void mem_cgroup_rotate_lru_list(struct page
*page
, enum lru_list lru
)
364 struct mem_cgroup_per_zone
*mz
;
365 struct page_cgroup
*pc
;
367 if (mem_cgroup_disabled())
370 pc
= lookup_page_cgroup(page
);
372 * Used bit is set without atomic ops but after smp_wmb().
373 * For making pc->mem_cgroup visible, insert smp_rmb() here.
376 /* unused page is not rotated. */
377 if (!PageCgroupUsed(pc
))
379 mz
= page_cgroup_zoneinfo(pc
);
380 list_move(&pc
->lru
, &mz
->lists
[lru
]);
383 void mem_cgroup_add_lru_list(struct page
*page
, enum lru_list lru
)
385 struct page_cgroup
*pc
;
386 struct mem_cgroup_per_zone
*mz
;
388 if (mem_cgroup_disabled())
390 pc
= lookup_page_cgroup(page
);
392 * Used bit is set without atomic ops but after smp_wmb().
393 * For making pc->mem_cgroup visible, insert smp_rmb() here.
396 if (!PageCgroupUsed(pc
))
399 mz
= page_cgroup_zoneinfo(pc
);
400 MEM_CGROUP_ZSTAT(mz
, lru
) += 1;
401 list_add(&pc
->lru
, &mz
->lists
[lru
]);
405 * At handling SwapCache, pc->mem_cgroup may be changed while it's linked to
406 * lru because the page may.be reused after it's fully uncharged (because of
407 * SwapCache behavior).To handle that, unlink page_cgroup from LRU when charge
408 * it again. This function is only used to charge SwapCache. It's done under
409 * lock_page and expected that zone->lru_lock is never held.
411 static void mem_cgroup_lru_del_before_commit_swapcache(struct page
*page
)
414 struct zone
*zone
= page_zone(page
);
415 struct page_cgroup
*pc
= lookup_page_cgroup(page
);
417 spin_lock_irqsave(&zone
->lru_lock
, flags
);
419 * Forget old LRU when this page_cgroup is *not* used. This Used bit
420 * is guarded by lock_page() because the page is SwapCache.
422 if (!PageCgroupUsed(pc
))
423 mem_cgroup_del_lru_list(page
, page_lru(page
));
424 spin_unlock_irqrestore(&zone
->lru_lock
, flags
);
427 static void mem_cgroup_lru_add_after_commit_swapcache(struct page
*page
)
430 struct zone
*zone
= page_zone(page
);
431 struct page_cgroup
*pc
= lookup_page_cgroup(page
);
433 spin_lock_irqsave(&zone
->lru_lock
, flags
);
434 /* link when the page is linked to LRU but page_cgroup isn't */
435 if (PageLRU(page
) && list_empty(&pc
->lru
))
436 mem_cgroup_add_lru_list(page
, page_lru(page
));
437 spin_unlock_irqrestore(&zone
->lru_lock
, flags
);
441 void mem_cgroup_move_lists(struct page
*page
,
442 enum lru_list from
, enum lru_list to
)
444 if (mem_cgroup_disabled())
446 mem_cgroup_del_lru_list(page
, from
);
447 mem_cgroup_add_lru_list(page
, to
);
450 int task_in_mem_cgroup(struct task_struct
*task
, const struct mem_cgroup
*mem
)
455 ret
= task
->mm
&& mm_match_cgroup(task
->mm
, mem
);
461 * Calculate mapped_ratio under memory controller. This will be used in
462 * vmscan.c for deteremining we have to reclaim mapped pages.
464 int mem_cgroup_calc_mapped_ratio(struct mem_cgroup
*mem
)
469 * usage is recorded in bytes. But, here, we assume the number of
470 * physical pages can be represented by "long" on any arch.
472 total
= (long) (mem
->res
.usage
>> PAGE_SHIFT
) + 1L;
473 rss
= (long)mem_cgroup_read_stat(&mem
->stat
, MEM_CGROUP_STAT_RSS
);
474 return (int)((rss
* 100L) / total
);
478 * prev_priority control...this will be used in memory reclaim path.
480 int mem_cgroup_get_reclaim_priority(struct mem_cgroup
*mem
)
484 spin_lock(&mem
->reclaim_param_lock
);
485 prev_priority
= mem
->prev_priority
;
486 spin_unlock(&mem
->reclaim_param_lock
);
488 return prev_priority
;
491 void mem_cgroup_note_reclaim_priority(struct mem_cgroup
*mem
, int priority
)
493 spin_lock(&mem
->reclaim_param_lock
);
494 if (priority
< mem
->prev_priority
)
495 mem
->prev_priority
= priority
;
496 spin_unlock(&mem
->reclaim_param_lock
);
499 void mem_cgroup_record_reclaim_priority(struct mem_cgroup
*mem
, int priority
)
501 spin_lock(&mem
->reclaim_param_lock
);
502 mem
->prev_priority
= priority
;
503 spin_unlock(&mem
->reclaim_param_lock
);
506 static int calc_inactive_ratio(struct mem_cgroup
*memcg
, unsigned long *present_pages
)
508 unsigned long active
;
509 unsigned long inactive
;
511 unsigned long inactive_ratio
;
513 inactive
= mem_cgroup_get_all_zonestat(memcg
, LRU_INACTIVE_ANON
);
514 active
= mem_cgroup_get_all_zonestat(memcg
, LRU_ACTIVE_ANON
);
516 gb
= (inactive
+ active
) >> (30 - PAGE_SHIFT
);
518 inactive_ratio
= int_sqrt(10 * gb
);
523 present_pages
[0] = inactive
;
524 present_pages
[1] = active
;
527 return inactive_ratio
;
530 int mem_cgroup_inactive_anon_is_low(struct mem_cgroup
*memcg
)
532 unsigned long active
;
533 unsigned long inactive
;
534 unsigned long present_pages
[2];
535 unsigned long inactive_ratio
;
537 inactive_ratio
= calc_inactive_ratio(memcg
, present_pages
);
539 inactive
= present_pages
[0];
540 active
= present_pages
[1];
542 if (inactive
* inactive_ratio
< active
)
548 unsigned long mem_cgroup_zone_nr_pages(struct mem_cgroup
*memcg
,
552 int nid
= zone
->zone_pgdat
->node_id
;
553 int zid
= zone_idx(zone
);
554 struct mem_cgroup_per_zone
*mz
= mem_cgroup_zoneinfo(memcg
, nid
, zid
);
556 return MEM_CGROUP_ZSTAT(mz
, lru
);
559 struct zone_reclaim_stat
*mem_cgroup_get_reclaim_stat(struct mem_cgroup
*memcg
,
562 int nid
= zone
->zone_pgdat
->node_id
;
563 int zid
= zone_idx(zone
);
564 struct mem_cgroup_per_zone
*mz
= mem_cgroup_zoneinfo(memcg
, nid
, zid
);
566 return &mz
->reclaim_stat
;
569 struct zone_reclaim_stat
*
570 mem_cgroup_get_reclaim_stat_from_page(struct page
*page
)
572 struct page_cgroup
*pc
;
573 struct mem_cgroup_per_zone
*mz
;
575 if (mem_cgroup_disabled())
578 pc
= lookup_page_cgroup(page
);
580 * Used bit is set without atomic ops but after smp_wmb().
581 * For making pc->mem_cgroup visible, insert smp_rmb() here.
584 if (!PageCgroupUsed(pc
))
587 mz
= page_cgroup_zoneinfo(pc
);
591 return &mz
->reclaim_stat
;
594 unsigned long mem_cgroup_isolate_pages(unsigned long nr_to_scan
,
595 struct list_head
*dst
,
596 unsigned long *scanned
, int order
,
597 int mode
, struct zone
*z
,
598 struct mem_cgroup
*mem_cont
,
599 int active
, int file
)
601 unsigned long nr_taken
= 0;
605 struct list_head
*src
;
606 struct page_cgroup
*pc
, *tmp
;
607 int nid
= z
->zone_pgdat
->node_id
;
608 int zid
= zone_idx(z
);
609 struct mem_cgroup_per_zone
*mz
;
610 int lru
= LRU_FILE
* !!file
+ !!active
;
613 mz
= mem_cgroup_zoneinfo(mem_cont
, nid
, zid
);
614 src
= &mz
->lists
[lru
];
617 list_for_each_entry_safe_reverse(pc
, tmp
, src
, lru
) {
618 if (scan
>= nr_to_scan
)
622 if (unlikely(!PageCgroupUsed(pc
)))
624 if (unlikely(!PageLRU(page
)))
628 if (__isolate_lru_page(page
, mode
, file
) == 0) {
629 list_move(&page
->lru
, dst
);
638 #define mem_cgroup_from_res_counter(counter, member) \
639 container_of(counter, struct mem_cgroup, member)
641 static bool mem_cgroup_check_under_limit(struct mem_cgroup
*mem
)
643 if (do_swap_account
) {
644 if (res_counter_check_under_limit(&mem
->res
) &&
645 res_counter_check_under_limit(&mem
->memsw
))
648 if (res_counter_check_under_limit(&mem
->res
))
653 static unsigned int get_swappiness(struct mem_cgroup
*memcg
)
655 struct cgroup
*cgrp
= memcg
->css
.cgroup
;
656 unsigned int swappiness
;
659 if (cgrp
->parent
== NULL
)
660 return vm_swappiness
;
662 spin_lock(&memcg
->reclaim_param_lock
);
663 swappiness
= memcg
->swappiness
;
664 spin_unlock(&memcg
->reclaim_param_lock
);
670 * Visit the first child (need not be the first child as per the ordering
671 * of the cgroup list, since we track last_scanned_child) of @mem and use
672 * that to reclaim free pages from.
674 static struct mem_cgroup
*
675 mem_cgroup_select_victim(struct mem_cgroup
*root_mem
)
677 struct mem_cgroup
*ret
= NULL
;
678 struct cgroup_subsys_state
*css
;
681 if (!root_mem
->use_hierarchy
) {
682 css_get(&root_mem
->css
);
688 nextid
= root_mem
->last_scanned_child
+ 1;
689 css
= css_get_next(&mem_cgroup_subsys
, nextid
, &root_mem
->css
,
691 if (css
&& css_tryget(css
))
692 ret
= container_of(css
, struct mem_cgroup
, css
);
695 /* Updates scanning parameter */
696 spin_lock(&root_mem
->reclaim_param_lock
);
698 /* this means start scan from ID:1 */
699 root_mem
->last_scanned_child
= 0;
701 root_mem
->last_scanned_child
= found
;
702 spin_unlock(&root_mem
->reclaim_param_lock
);
709 * Scan the hierarchy if needed to reclaim memory. We remember the last child
710 * we reclaimed from, so that we don't end up penalizing one child extensively
711 * based on its position in the children list.
713 * root_mem is the original ancestor that we've been reclaim from.
715 * We give up and return to the caller when we visit root_mem twice.
716 * (other groups can be removed while we're walking....)
718 static int mem_cgroup_hierarchical_reclaim(struct mem_cgroup
*root_mem
,
719 gfp_t gfp_mask
, bool noswap
)
721 struct mem_cgroup
*victim
;
726 victim
= mem_cgroup_select_victim(root_mem
);
727 if (victim
== root_mem
)
729 if (!mem_cgroup_local_usage(&victim
->stat
)) {
730 /* this cgroup's local usage == 0 */
731 css_put(&victim
->css
);
734 /* we use swappiness of local cgroup */
735 ret
= try_to_free_mem_cgroup_pages(victim
, gfp_mask
, noswap
,
736 get_swappiness(victim
));
737 css_put(&victim
->css
);
739 if (mem_cgroup_check_under_limit(root_mem
))
745 bool mem_cgroup_oom_called(struct task_struct
*task
)
748 struct mem_cgroup
*mem
;
749 struct mm_struct
*mm
;
755 mem
= mem_cgroup_from_task(rcu_dereference(mm
->owner
));
756 if (mem
&& time_before(jiffies
, mem
->last_oom_jiffies
+ HZ
/10))
762 * Unlike exported interface, "oom" parameter is added. if oom==true,
763 * oom-killer can be invoked.
765 static int __mem_cgroup_try_charge(struct mm_struct
*mm
,
766 gfp_t gfp_mask
, struct mem_cgroup
**memcg
,
769 struct mem_cgroup
*mem
, *mem_over_limit
;
770 int nr_retries
= MEM_CGROUP_RECLAIM_RETRIES
;
771 struct res_counter
*fail_res
;
773 if (unlikely(test_thread_flag(TIF_MEMDIE
))) {
774 /* Don't account this! */
780 * We always charge the cgroup the mm_struct belongs to.
781 * The mm_struct's mem_cgroup changes on task migration if the
782 * thread group leader migrates. It's possible that mm is not
783 * set, if so charge the init_mm (happens for pagecache usage).
787 mem
= try_get_mem_cgroup_from_mm(mm
);
795 VM_BUG_ON(mem_cgroup_is_obsolete(mem
));
801 ret
= res_counter_charge(&mem
->res
, PAGE_SIZE
, &fail_res
);
803 if (!do_swap_account
)
805 ret
= res_counter_charge(&mem
->memsw
, PAGE_SIZE
,
809 /* mem+swap counter fails */
810 res_counter_uncharge(&mem
->res
, PAGE_SIZE
);
812 mem_over_limit
= mem_cgroup_from_res_counter(fail_res
,
815 /* mem counter fails */
816 mem_over_limit
= mem_cgroup_from_res_counter(fail_res
,
819 if (!(gfp_mask
& __GFP_WAIT
))
822 ret
= mem_cgroup_hierarchical_reclaim(mem_over_limit
, gfp_mask
,
828 * try_to_free_mem_cgroup_pages() might not give us a full
829 * picture of reclaim. Some pages are reclaimed and might be
830 * moved to swap cache or just unmapped from the cgroup.
831 * Check the limit again to see if the reclaim reduced the
832 * current usage of the cgroup before giving up
835 if (mem_cgroup_check_under_limit(mem_over_limit
))
840 mutex_lock(&memcg_tasklist
);
841 mem_cgroup_out_of_memory(mem_over_limit
, gfp_mask
);
842 mutex_unlock(&memcg_tasklist
);
843 mem_over_limit
->last_oom_jiffies
= jiffies
;
854 static struct mem_cgroup
*try_get_mem_cgroup_from_swapcache(struct page
*page
)
856 struct mem_cgroup
*mem
;
859 if (!PageSwapCache(page
))
862 ent
.val
= page_private(page
);
863 mem
= lookup_swap_cgroup(ent
);
866 if (!css_tryget(&mem
->css
))
872 * commit a charge got by __mem_cgroup_try_charge() and makes page_cgroup to be
873 * USED state. If already USED, uncharge and return.
876 static void __mem_cgroup_commit_charge(struct mem_cgroup
*mem
,
877 struct page_cgroup
*pc
,
878 enum charge_type ctype
)
880 /* try_charge() can return NULL to *memcg, taking care of it. */
884 lock_page_cgroup(pc
);
885 if (unlikely(PageCgroupUsed(pc
))) {
886 unlock_page_cgroup(pc
);
887 res_counter_uncharge(&mem
->res
, PAGE_SIZE
);
889 res_counter_uncharge(&mem
->memsw
, PAGE_SIZE
);
893 pc
->mem_cgroup
= mem
;
895 pc
->flags
= pcg_default_flags
[ctype
];
897 mem_cgroup_charge_statistics(mem
, pc
, true);
899 unlock_page_cgroup(pc
);
903 * mem_cgroup_move_account - move account of the page
904 * @pc: page_cgroup of the page.
905 * @from: mem_cgroup which the page is moved from.
906 * @to: mem_cgroup which the page is moved to. @from != @to.
908 * The caller must confirm following.
909 * - page is not on LRU (isolate_page() is useful.)
911 * returns 0 at success,
912 * returns -EBUSY when lock is busy or "pc" is unstable.
914 * This function does "uncharge" from old cgroup but doesn't do "charge" to
915 * new cgroup. It should be done by a caller.
918 static int mem_cgroup_move_account(struct page_cgroup
*pc
,
919 struct mem_cgroup
*from
, struct mem_cgroup
*to
)
921 struct mem_cgroup_per_zone
*from_mz
, *to_mz
;
925 VM_BUG_ON(from
== to
);
926 VM_BUG_ON(PageLRU(pc
->page
));
928 nid
= page_cgroup_nid(pc
);
929 zid
= page_cgroup_zid(pc
);
930 from_mz
= mem_cgroup_zoneinfo(from
, nid
, zid
);
931 to_mz
= mem_cgroup_zoneinfo(to
, nid
, zid
);
933 if (!trylock_page_cgroup(pc
))
936 if (!PageCgroupUsed(pc
))
939 if (pc
->mem_cgroup
!= from
)
942 res_counter_uncharge(&from
->res
, PAGE_SIZE
);
943 mem_cgroup_charge_statistics(from
, pc
, false);
945 res_counter_uncharge(&from
->memsw
, PAGE_SIZE
);
950 mem_cgroup_charge_statistics(to
, pc
, true);
953 unlock_page_cgroup(pc
);
958 * move charges to its parent.
961 static int mem_cgroup_move_parent(struct page_cgroup
*pc
,
962 struct mem_cgroup
*child
,
965 struct page
*page
= pc
->page
;
966 struct cgroup
*cg
= child
->css
.cgroup
;
967 struct cgroup
*pcg
= cg
->parent
;
968 struct mem_cgroup
*parent
;
976 parent
= mem_cgroup_from_cont(pcg
);
979 ret
= __mem_cgroup_try_charge(NULL
, gfp_mask
, &parent
, false);
983 if (!get_page_unless_zero(page
)) {
988 ret
= isolate_lru_page(page
);
993 ret
= mem_cgroup_move_account(pc
, child
, parent
);
995 putback_lru_page(page
);
998 /* drop extra refcnt by try_charge() */
999 css_put(&parent
->css
);
1006 /* drop extra refcnt by try_charge() */
1007 css_put(&parent
->css
);
1008 /* uncharge if move fails */
1009 res_counter_uncharge(&parent
->res
, PAGE_SIZE
);
1010 if (do_swap_account
)
1011 res_counter_uncharge(&parent
->memsw
, PAGE_SIZE
);
1016 * Charge the memory controller for page usage.
1018 * 0 if the charge was successful
1019 * < 0 if the cgroup is over its limit
1021 static int mem_cgroup_charge_common(struct page
*page
, struct mm_struct
*mm
,
1022 gfp_t gfp_mask
, enum charge_type ctype
,
1023 struct mem_cgroup
*memcg
)
1025 struct mem_cgroup
*mem
;
1026 struct page_cgroup
*pc
;
1029 pc
= lookup_page_cgroup(page
);
1030 /* can happen at boot */
1036 ret
= __mem_cgroup_try_charge(mm
, gfp_mask
, &mem
, true);
1040 __mem_cgroup_commit_charge(mem
, pc
, ctype
);
1044 int mem_cgroup_newpage_charge(struct page
*page
,
1045 struct mm_struct
*mm
, gfp_t gfp_mask
)
1047 if (mem_cgroup_disabled())
1049 if (PageCompound(page
))
1052 * If already mapped, we don't have to account.
1053 * If page cache, page->mapping has address_space.
1054 * But page->mapping may have out-of-use anon_vma pointer,
1055 * detecit it by PageAnon() check. newly-mapped-anon's page->mapping
1058 if (page_mapped(page
) || (page
->mapping
&& !PageAnon(page
)))
1062 return mem_cgroup_charge_common(page
, mm
, gfp_mask
,
1063 MEM_CGROUP_CHARGE_TYPE_MAPPED
, NULL
);
1066 int mem_cgroup_cache_charge(struct page
*page
, struct mm_struct
*mm
,
1069 struct mem_cgroup
*mem
= NULL
;
1072 if (mem_cgroup_disabled())
1074 if (PageCompound(page
))
1077 * Corner case handling. This is called from add_to_page_cache()
1078 * in usual. But some FS (shmem) precharges this page before calling it
1079 * and call add_to_page_cache() with GFP_NOWAIT.
1081 * For GFP_NOWAIT case, the page may be pre-charged before calling
1082 * add_to_page_cache(). (See shmem.c) check it here and avoid to call
1083 * charge twice. (It works but has to pay a bit larger cost.)
1084 * And when the page is SwapCache, it should take swap information
1085 * into account. This is under lock_page() now.
1087 if (!(gfp_mask
& __GFP_WAIT
)) {
1088 struct page_cgroup
*pc
;
1091 pc
= lookup_page_cgroup(page
);
1094 lock_page_cgroup(pc
);
1095 if (PageCgroupUsed(pc
)) {
1096 unlock_page_cgroup(pc
);
1099 unlock_page_cgroup(pc
);
1102 if (do_swap_account
&& PageSwapCache(page
)) {
1103 mem
= try_get_mem_cgroup_from_swapcache(page
);
1108 /* SwapCache may be still linked to LRU now. */
1109 mem_cgroup_lru_del_before_commit_swapcache(page
);
1112 if (unlikely(!mm
&& !mem
))
1115 if (page_is_file_cache(page
))
1116 return mem_cgroup_charge_common(page
, mm
, gfp_mask
,
1117 MEM_CGROUP_CHARGE_TYPE_CACHE
, NULL
);
1119 ret
= mem_cgroup_charge_common(page
, mm
, gfp_mask
,
1120 MEM_CGROUP_CHARGE_TYPE_SHMEM
, mem
);
1123 if (PageSwapCache(page
))
1124 mem_cgroup_lru_add_after_commit_swapcache(page
);
1126 if (do_swap_account
&& !ret
&& PageSwapCache(page
)) {
1127 swp_entry_t ent
= {.val
= page_private(page
)};
1128 /* avoid double counting */
1129 mem
= swap_cgroup_record(ent
, NULL
);
1131 res_counter_uncharge(&mem
->memsw
, PAGE_SIZE
);
1132 mem_cgroup_put(mem
);
1139 * While swap-in, try_charge -> commit or cancel, the page is locked.
1140 * And when try_charge() successfully returns, one refcnt to memcg without
1141 * struct page_cgroup is aquired. This refcnt will be cumsumed by
1142 * "commit()" or removed by "cancel()"
1144 int mem_cgroup_try_charge_swapin(struct mm_struct
*mm
,
1146 gfp_t mask
, struct mem_cgroup
**ptr
)
1148 struct mem_cgroup
*mem
;
1151 if (mem_cgroup_disabled())
1154 if (!do_swap_account
)
1157 * A racing thread's fault, or swapoff, may have already updated
1158 * the pte, and even removed page from swap cache: return success
1159 * to go on to do_swap_page()'s pte_same() test, which should fail.
1161 if (!PageSwapCache(page
))
1163 mem
= try_get_mem_cgroup_from_swapcache(page
);
1167 ret
= __mem_cgroup_try_charge(NULL
, mask
, ptr
, true);
1168 /* drop extra refcnt from tryget */
1174 return __mem_cgroup_try_charge(mm
, mask
, ptr
, true);
1177 void mem_cgroup_commit_charge_swapin(struct page
*page
, struct mem_cgroup
*ptr
)
1179 struct page_cgroup
*pc
;
1181 if (mem_cgroup_disabled())
1185 pc
= lookup_page_cgroup(page
);
1186 mem_cgroup_lru_del_before_commit_swapcache(page
);
1187 __mem_cgroup_commit_charge(ptr
, pc
, MEM_CGROUP_CHARGE_TYPE_MAPPED
);
1188 mem_cgroup_lru_add_after_commit_swapcache(page
);
1190 * Now swap is on-memory. This means this page may be
1191 * counted both as mem and swap....double count.
1192 * Fix it by uncharging from memsw. Basically, this SwapCache is stable
1193 * under lock_page(). But in do_swap_page()::memory.c, reuse_swap_page()
1194 * may call delete_from_swap_cache() before reach here.
1196 if (do_swap_account
&& PageSwapCache(page
)) {
1197 swp_entry_t ent
= {.val
= page_private(page
)};
1198 struct mem_cgroup
*memcg
;
1199 memcg
= swap_cgroup_record(ent
, NULL
);
1201 res_counter_uncharge(&memcg
->memsw
, PAGE_SIZE
);
1202 mem_cgroup_put(memcg
);
1206 /* add this page(page_cgroup) to the LRU we want. */
1210 void mem_cgroup_cancel_charge_swapin(struct mem_cgroup
*mem
)
1212 if (mem_cgroup_disabled())
1216 res_counter_uncharge(&mem
->res
, PAGE_SIZE
);
1217 if (do_swap_account
)
1218 res_counter_uncharge(&mem
->memsw
, PAGE_SIZE
);
1224 * uncharge if !page_mapped(page)
1226 static struct mem_cgroup
*
1227 __mem_cgroup_uncharge_common(struct page
*page
, enum charge_type ctype
)
1229 struct page_cgroup
*pc
;
1230 struct mem_cgroup
*mem
= NULL
;
1231 struct mem_cgroup_per_zone
*mz
;
1233 if (mem_cgroup_disabled())
1236 if (PageSwapCache(page
))
1240 * Check if our page_cgroup is valid
1242 pc
= lookup_page_cgroup(page
);
1243 if (unlikely(!pc
|| !PageCgroupUsed(pc
)))
1246 lock_page_cgroup(pc
);
1248 mem
= pc
->mem_cgroup
;
1250 if (!PageCgroupUsed(pc
))
1254 case MEM_CGROUP_CHARGE_TYPE_MAPPED
:
1255 if (page_mapped(page
))
1258 case MEM_CGROUP_CHARGE_TYPE_SWAPOUT
:
1259 if (!PageAnon(page
)) { /* Shared memory */
1260 if (page
->mapping
&& !page_is_file_cache(page
))
1262 } else if (page_mapped(page
)) /* Anon */
1269 res_counter_uncharge(&mem
->res
, PAGE_SIZE
);
1270 if (do_swap_account
&& (ctype
!= MEM_CGROUP_CHARGE_TYPE_SWAPOUT
))
1271 res_counter_uncharge(&mem
->memsw
, PAGE_SIZE
);
1272 mem_cgroup_charge_statistics(mem
, pc
, false);
1274 ClearPageCgroupUsed(pc
);
1276 * pc->mem_cgroup is not cleared here. It will be accessed when it's
1277 * freed from LRU. This is safe because uncharged page is expected not
1278 * to be reused (freed soon). Exception is SwapCache, it's handled by
1279 * special functions.
1282 mz
= page_cgroup_zoneinfo(pc
);
1283 unlock_page_cgroup(pc
);
1285 /* at swapout, this memcg will be accessed to record to swap */
1286 if (ctype
!= MEM_CGROUP_CHARGE_TYPE_SWAPOUT
)
1292 unlock_page_cgroup(pc
);
1296 void mem_cgroup_uncharge_page(struct page
*page
)
1299 if (page_mapped(page
))
1301 if (page
->mapping
&& !PageAnon(page
))
1303 __mem_cgroup_uncharge_common(page
, MEM_CGROUP_CHARGE_TYPE_MAPPED
);
1306 void mem_cgroup_uncharge_cache_page(struct page
*page
)
1308 VM_BUG_ON(page_mapped(page
));
1309 VM_BUG_ON(page
->mapping
);
1310 __mem_cgroup_uncharge_common(page
, MEM_CGROUP_CHARGE_TYPE_CACHE
);
1314 * called from __delete_from_swap_cache() and drop "page" account.
1315 * memcg information is recorded to swap_cgroup of "ent"
1317 void mem_cgroup_uncharge_swapcache(struct page
*page
, swp_entry_t ent
)
1319 struct mem_cgroup
*memcg
;
1321 memcg
= __mem_cgroup_uncharge_common(page
,
1322 MEM_CGROUP_CHARGE_TYPE_SWAPOUT
);
1323 /* record memcg information */
1324 if (do_swap_account
&& memcg
) {
1325 swap_cgroup_record(ent
, memcg
);
1326 mem_cgroup_get(memcg
);
1329 css_put(&memcg
->css
);
1332 #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP
1334 * called from swap_entry_free(). remove record in swap_cgroup and
1335 * uncharge "memsw" account.
1337 void mem_cgroup_uncharge_swap(swp_entry_t ent
)
1339 struct mem_cgroup
*memcg
;
1341 if (!do_swap_account
)
1344 memcg
= swap_cgroup_record(ent
, NULL
);
1346 res_counter_uncharge(&memcg
->memsw
, PAGE_SIZE
);
1347 mem_cgroup_put(memcg
);
1353 * Before starting migration, account PAGE_SIZE to mem_cgroup that the old
1356 int mem_cgroup_prepare_migration(struct page
*page
, struct mem_cgroup
**ptr
)
1358 struct page_cgroup
*pc
;
1359 struct mem_cgroup
*mem
= NULL
;
1362 if (mem_cgroup_disabled())
1365 pc
= lookup_page_cgroup(page
);
1366 lock_page_cgroup(pc
);
1367 if (PageCgroupUsed(pc
)) {
1368 mem
= pc
->mem_cgroup
;
1371 unlock_page_cgroup(pc
);
1374 ret
= __mem_cgroup_try_charge(NULL
, GFP_KERNEL
, &mem
, false);
1381 /* remove redundant charge if migration failed*/
1382 void mem_cgroup_end_migration(struct mem_cgroup
*mem
,
1383 struct page
*oldpage
, struct page
*newpage
)
1385 struct page
*target
, *unused
;
1386 struct page_cgroup
*pc
;
1387 enum charge_type ctype
;
1392 /* at migration success, oldpage->mapping is NULL. */
1393 if (oldpage
->mapping
) {
1401 if (PageAnon(target
))
1402 ctype
= MEM_CGROUP_CHARGE_TYPE_MAPPED
;
1403 else if (page_is_file_cache(target
))
1404 ctype
= MEM_CGROUP_CHARGE_TYPE_CACHE
;
1406 ctype
= MEM_CGROUP_CHARGE_TYPE_SHMEM
;
1408 /* unused page is not on radix-tree now. */
1410 __mem_cgroup_uncharge_common(unused
, ctype
);
1412 pc
= lookup_page_cgroup(target
);
1414 * __mem_cgroup_commit_charge() check PCG_USED bit of page_cgroup.
1415 * So, double-counting is effectively avoided.
1417 __mem_cgroup_commit_charge(mem
, pc
, ctype
);
1420 * Both of oldpage and newpage are still under lock_page().
1421 * Then, we don't have to care about race in radix-tree.
1422 * But we have to be careful that this page is unmapped or not.
1424 * There is a case for !page_mapped(). At the start of
1425 * migration, oldpage was mapped. But now, it's zapped.
1426 * But we know *target* page is not freed/reused under us.
1427 * mem_cgroup_uncharge_page() does all necessary checks.
1429 if (ctype
== MEM_CGROUP_CHARGE_TYPE_MAPPED
)
1430 mem_cgroup_uncharge_page(target
);
1434 * A call to try to shrink memory usage under specified resource controller.
1435 * This is typically used for page reclaiming for shmem for reducing side
1436 * effect of page allocation from shmem, which is used by some mem_cgroup.
1438 int mem_cgroup_shrink_usage(struct page
*page
,
1439 struct mm_struct
*mm
,
1442 struct mem_cgroup
*mem
= NULL
;
1444 int retry
= MEM_CGROUP_RECLAIM_RETRIES
;
1446 if (mem_cgroup_disabled())
1449 mem
= try_get_mem_cgroup_from_swapcache(page
);
1451 mem
= try_get_mem_cgroup_from_mm(mm
);
1456 progress
= mem_cgroup_hierarchical_reclaim(mem
, gfp_mask
, true);
1457 progress
+= mem_cgroup_check_under_limit(mem
);
1458 } while (!progress
&& --retry
);
1466 static DEFINE_MUTEX(set_limit_mutex
);
1468 static int mem_cgroup_resize_limit(struct mem_cgroup
*memcg
,
1469 unsigned long long val
)
1472 int retry_count
= MEM_CGROUP_RECLAIM_RETRIES
;
1477 while (retry_count
) {
1478 if (signal_pending(current
)) {
1483 * Rather than hide all in some function, I do this in
1484 * open coded manner. You see what this really does.
1485 * We have to guarantee mem->res.limit < mem->memsw.limit.
1487 mutex_lock(&set_limit_mutex
);
1488 memswlimit
= res_counter_read_u64(&memcg
->memsw
, RES_LIMIT
);
1489 if (memswlimit
< val
) {
1491 mutex_unlock(&set_limit_mutex
);
1494 ret
= res_counter_set_limit(&memcg
->res
, val
);
1495 mutex_unlock(&set_limit_mutex
);
1500 progress
= mem_cgroup_hierarchical_reclaim(memcg
, GFP_KERNEL
,
1502 if (!progress
) retry_count
--;
1508 int mem_cgroup_resize_memsw_limit(struct mem_cgroup
*memcg
,
1509 unsigned long long val
)
1511 int retry_count
= MEM_CGROUP_RECLAIM_RETRIES
;
1512 u64 memlimit
, oldusage
, curusage
;
1515 if (!do_swap_account
)
1518 while (retry_count
) {
1519 if (signal_pending(current
)) {
1524 * Rather than hide all in some function, I do this in
1525 * open coded manner. You see what this really does.
1526 * We have to guarantee mem->res.limit < mem->memsw.limit.
1528 mutex_lock(&set_limit_mutex
);
1529 memlimit
= res_counter_read_u64(&memcg
->res
, RES_LIMIT
);
1530 if (memlimit
> val
) {
1532 mutex_unlock(&set_limit_mutex
);
1535 ret
= res_counter_set_limit(&memcg
->memsw
, val
);
1536 mutex_unlock(&set_limit_mutex
);
1541 oldusage
= res_counter_read_u64(&memcg
->memsw
, RES_USAGE
);
1542 mem_cgroup_hierarchical_reclaim(memcg
, GFP_KERNEL
, true);
1543 curusage
= res_counter_read_u64(&memcg
->memsw
, RES_USAGE
);
1544 if (curusage
>= oldusage
)
1551 * This routine traverse page_cgroup in given list and drop them all.
1552 * *And* this routine doesn't reclaim page itself, just removes page_cgroup.
1554 static int mem_cgroup_force_empty_list(struct mem_cgroup
*mem
,
1555 int node
, int zid
, enum lru_list lru
)
1558 struct mem_cgroup_per_zone
*mz
;
1559 struct page_cgroup
*pc
, *busy
;
1560 unsigned long flags
, loop
;
1561 struct list_head
*list
;
1564 zone
= &NODE_DATA(node
)->node_zones
[zid
];
1565 mz
= mem_cgroup_zoneinfo(mem
, node
, zid
);
1566 list
= &mz
->lists
[lru
];
1568 loop
= MEM_CGROUP_ZSTAT(mz
, lru
);
1569 /* give some margin against EBUSY etc...*/
1574 spin_lock_irqsave(&zone
->lru_lock
, flags
);
1575 if (list_empty(list
)) {
1576 spin_unlock_irqrestore(&zone
->lru_lock
, flags
);
1579 pc
= list_entry(list
->prev
, struct page_cgroup
, lru
);
1581 list_move(&pc
->lru
, list
);
1583 spin_unlock_irqrestore(&zone
->lru_lock
, flags
);
1586 spin_unlock_irqrestore(&zone
->lru_lock
, flags
);
1588 ret
= mem_cgroup_move_parent(pc
, mem
, GFP_KERNEL
);
1592 if (ret
== -EBUSY
|| ret
== -EINVAL
) {
1593 /* found lock contention or "pc" is obsolete. */
1600 if (!ret
&& !list_empty(list
))
1606 * make mem_cgroup's charge to be 0 if there is no task.
1607 * This enables deleting this mem_cgroup.
1609 static int mem_cgroup_force_empty(struct mem_cgroup
*mem
, bool free_all
)
1612 int node
, zid
, shrink
;
1613 int nr_retries
= MEM_CGROUP_RECLAIM_RETRIES
;
1614 struct cgroup
*cgrp
= mem
->css
.cgroup
;
1619 /* should free all ? */
1623 while (mem
->res
.usage
> 0) {
1625 if (cgroup_task_count(cgrp
) || !list_empty(&cgrp
->children
))
1628 if (signal_pending(current
))
1630 /* This is for making all *used* pages to be on LRU. */
1631 lru_add_drain_all();
1633 for_each_node_state(node
, N_HIGH_MEMORY
) {
1634 for (zid
= 0; !ret
&& zid
< MAX_NR_ZONES
; zid
++) {
1637 ret
= mem_cgroup_force_empty_list(mem
,
1646 /* it seems parent cgroup doesn't have enough mem */
1657 /* returns EBUSY if there is a task or if we come here twice. */
1658 if (cgroup_task_count(cgrp
) || !list_empty(&cgrp
->children
) || shrink
) {
1662 /* we call try-to-free pages for make this cgroup empty */
1663 lru_add_drain_all();
1664 /* try to free all pages in this cgroup */
1666 while (nr_retries
&& mem
->res
.usage
> 0) {
1669 if (signal_pending(current
)) {
1673 progress
= try_to_free_mem_cgroup_pages(mem
, GFP_KERNEL
,
1674 false, get_swappiness(mem
));
1677 /* maybe some writeback is necessary */
1678 congestion_wait(WRITE
, HZ
/10);
1683 /* try move_account...there may be some *locked* pages. */
1690 int mem_cgroup_force_empty_write(struct cgroup
*cont
, unsigned int event
)
1692 return mem_cgroup_force_empty(mem_cgroup_from_cont(cont
), true);
1696 static u64
mem_cgroup_hierarchy_read(struct cgroup
*cont
, struct cftype
*cft
)
1698 return mem_cgroup_from_cont(cont
)->use_hierarchy
;
1701 static int mem_cgroup_hierarchy_write(struct cgroup
*cont
, struct cftype
*cft
,
1705 struct mem_cgroup
*mem
= mem_cgroup_from_cont(cont
);
1706 struct cgroup
*parent
= cont
->parent
;
1707 struct mem_cgroup
*parent_mem
= NULL
;
1710 parent_mem
= mem_cgroup_from_cont(parent
);
1714 * If parent's use_hiearchy is set, we can't make any modifications
1715 * in the child subtrees. If it is unset, then the change can
1716 * occur, provided the current cgroup has no children.
1718 * For the root cgroup, parent_mem is NULL, we allow value to be
1719 * set if there are no children.
1721 if ((!parent_mem
|| !parent_mem
->use_hierarchy
) &&
1722 (val
== 1 || val
== 0)) {
1723 if (list_empty(&cont
->children
))
1724 mem
->use_hierarchy
= val
;
1734 static u64
mem_cgroup_read(struct cgroup
*cont
, struct cftype
*cft
)
1736 struct mem_cgroup
*mem
= mem_cgroup_from_cont(cont
);
1740 type
= MEMFILE_TYPE(cft
->private);
1741 name
= MEMFILE_ATTR(cft
->private);
1744 val
= res_counter_read_u64(&mem
->res
, name
);
1747 if (do_swap_account
)
1748 val
= res_counter_read_u64(&mem
->memsw
, name
);
1757 * The user of this function is...
1760 static int mem_cgroup_write(struct cgroup
*cont
, struct cftype
*cft
,
1763 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cont
);
1765 unsigned long long val
;
1768 type
= MEMFILE_TYPE(cft
->private);
1769 name
= MEMFILE_ATTR(cft
->private);
1772 /* This function does all necessary parse...reuse it */
1773 ret
= res_counter_memparse_write_strategy(buffer
, &val
);
1777 ret
= mem_cgroup_resize_limit(memcg
, val
);
1779 ret
= mem_cgroup_resize_memsw_limit(memcg
, val
);
1782 ret
= -EINVAL
; /* should be BUG() ? */
1788 static void memcg_get_hierarchical_limit(struct mem_cgroup
*memcg
,
1789 unsigned long long *mem_limit
, unsigned long long *memsw_limit
)
1791 struct cgroup
*cgroup
;
1792 unsigned long long min_limit
, min_memsw_limit
, tmp
;
1794 min_limit
= res_counter_read_u64(&memcg
->res
, RES_LIMIT
);
1795 min_memsw_limit
= res_counter_read_u64(&memcg
->memsw
, RES_LIMIT
);
1796 cgroup
= memcg
->css
.cgroup
;
1797 if (!memcg
->use_hierarchy
)
1800 while (cgroup
->parent
) {
1801 cgroup
= cgroup
->parent
;
1802 memcg
= mem_cgroup_from_cont(cgroup
);
1803 if (!memcg
->use_hierarchy
)
1805 tmp
= res_counter_read_u64(&memcg
->res
, RES_LIMIT
);
1806 min_limit
= min(min_limit
, tmp
);
1807 tmp
= res_counter_read_u64(&memcg
->memsw
, RES_LIMIT
);
1808 min_memsw_limit
= min(min_memsw_limit
, tmp
);
1811 *mem_limit
= min_limit
;
1812 *memsw_limit
= min_memsw_limit
;
1816 static int mem_cgroup_reset(struct cgroup
*cont
, unsigned int event
)
1818 struct mem_cgroup
*mem
;
1821 mem
= mem_cgroup_from_cont(cont
);
1822 type
= MEMFILE_TYPE(event
);
1823 name
= MEMFILE_ATTR(event
);
1827 res_counter_reset_max(&mem
->res
);
1829 res_counter_reset_max(&mem
->memsw
);
1833 res_counter_reset_failcnt(&mem
->res
);
1835 res_counter_reset_failcnt(&mem
->memsw
);
1841 static const struct mem_cgroup_stat_desc
{
1844 } mem_cgroup_stat_desc
[] = {
1845 [MEM_CGROUP_STAT_CACHE
] = { "cache", PAGE_SIZE
, },
1846 [MEM_CGROUP_STAT_RSS
] = { "rss", PAGE_SIZE
, },
1847 [MEM_CGROUP_STAT_PGPGIN_COUNT
] = {"pgpgin", 1, },
1848 [MEM_CGROUP_STAT_PGPGOUT_COUNT
] = {"pgpgout", 1, },
1851 static int mem_control_stat_show(struct cgroup
*cont
, struct cftype
*cft
,
1852 struct cgroup_map_cb
*cb
)
1854 struct mem_cgroup
*mem_cont
= mem_cgroup_from_cont(cont
);
1855 struct mem_cgroup_stat
*stat
= &mem_cont
->stat
;
1858 for (i
= 0; i
< ARRAY_SIZE(stat
->cpustat
[0].count
); i
++) {
1861 val
= mem_cgroup_read_stat(stat
, i
);
1862 val
*= mem_cgroup_stat_desc
[i
].unit
;
1863 cb
->fill(cb
, mem_cgroup_stat_desc
[i
].msg
, val
);
1865 /* showing # of active pages */
1867 unsigned long active_anon
, inactive_anon
;
1868 unsigned long active_file
, inactive_file
;
1869 unsigned long unevictable
;
1871 inactive_anon
= mem_cgroup_get_all_zonestat(mem_cont
,
1873 active_anon
= mem_cgroup_get_all_zonestat(mem_cont
,
1875 inactive_file
= mem_cgroup_get_all_zonestat(mem_cont
,
1877 active_file
= mem_cgroup_get_all_zonestat(mem_cont
,
1879 unevictable
= mem_cgroup_get_all_zonestat(mem_cont
,
1882 cb
->fill(cb
, "active_anon", (active_anon
) * PAGE_SIZE
);
1883 cb
->fill(cb
, "inactive_anon", (inactive_anon
) * PAGE_SIZE
);
1884 cb
->fill(cb
, "active_file", (active_file
) * PAGE_SIZE
);
1885 cb
->fill(cb
, "inactive_file", (inactive_file
) * PAGE_SIZE
);
1886 cb
->fill(cb
, "unevictable", unevictable
* PAGE_SIZE
);
1890 unsigned long long limit
, memsw_limit
;
1891 memcg_get_hierarchical_limit(mem_cont
, &limit
, &memsw_limit
);
1892 cb
->fill(cb
, "hierarchical_memory_limit", limit
);
1893 if (do_swap_account
)
1894 cb
->fill(cb
, "hierarchical_memsw_limit", memsw_limit
);
1897 #ifdef CONFIG_DEBUG_VM
1898 cb
->fill(cb
, "inactive_ratio", calc_inactive_ratio(mem_cont
, NULL
));
1902 struct mem_cgroup_per_zone
*mz
;
1903 unsigned long recent_rotated
[2] = {0, 0};
1904 unsigned long recent_scanned
[2] = {0, 0};
1906 for_each_online_node(nid
)
1907 for (zid
= 0; zid
< MAX_NR_ZONES
; zid
++) {
1908 mz
= mem_cgroup_zoneinfo(mem_cont
, nid
, zid
);
1910 recent_rotated
[0] +=
1911 mz
->reclaim_stat
.recent_rotated
[0];
1912 recent_rotated
[1] +=
1913 mz
->reclaim_stat
.recent_rotated
[1];
1914 recent_scanned
[0] +=
1915 mz
->reclaim_stat
.recent_scanned
[0];
1916 recent_scanned
[1] +=
1917 mz
->reclaim_stat
.recent_scanned
[1];
1919 cb
->fill(cb
, "recent_rotated_anon", recent_rotated
[0]);
1920 cb
->fill(cb
, "recent_rotated_file", recent_rotated
[1]);
1921 cb
->fill(cb
, "recent_scanned_anon", recent_scanned
[0]);
1922 cb
->fill(cb
, "recent_scanned_file", recent_scanned
[1]);
1929 static u64
mem_cgroup_swappiness_read(struct cgroup
*cgrp
, struct cftype
*cft
)
1931 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cgrp
);
1933 return get_swappiness(memcg
);
1936 static int mem_cgroup_swappiness_write(struct cgroup
*cgrp
, struct cftype
*cft
,
1939 struct mem_cgroup
*memcg
= mem_cgroup_from_cont(cgrp
);
1940 struct mem_cgroup
*parent
;
1945 if (cgrp
->parent
== NULL
)
1948 parent
= mem_cgroup_from_cont(cgrp
->parent
);
1952 /* If under hierarchy, only empty-root can set this value */
1953 if ((parent
->use_hierarchy
) ||
1954 (memcg
->use_hierarchy
&& !list_empty(&cgrp
->children
))) {
1959 spin_lock(&memcg
->reclaim_param_lock
);
1960 memcg
->swappiness
= val
;
1961 spin_unlock(&memcg
->reclaim_param_lock
);
1969 static struct cftype mem_cgroup_files
[] = {
1971 .name
= "usage_in_bytes",
1972 .private = MEMFILE_PRIVATE(_MEM
, RES_USAGE
),
1973 .read_u64
= mem_cgroup_read
,
1976 .name
= "max_usage_in_bytes",
1977 .private = MEMFILE_PRIVATE(_MEM
, RES_MAX_USAGE
),
1978 .trigger
= mem_cgroup_reset
,
1979 .read_u64
= mem_cgroup_read
,
1982 .name
= "limit_in_bytes",
1983 .private = MEMFILE_PRIVATE(_MEM
, RES_LIMIT
),
1984 .write_string
= mem_cgroup_write
,
1985 .read_u64
= mem_cgroup_read
,
1989 .private = MEMFILE_PRIVATE(_MEM
, RES_FAILCNT
),
1990 .trigger
= mem_cgroup_reset
,
1991 .read_u64
= mem_cgroup_read
,
1995 .read_map
= mem_control_stat_show
,
1998 .name
= "force_empty",
1999 .trigger
= mem_cgroup_force_empty_write
,
2002 .name
= "use_hierarchy",
2003 .write_u64
= mem_cgroup_hierarchy_write
,
2004 .read_u64
= mem_cgroup_hierarchy_read
,
2007 .name
= "swappiness",
2008 .read_u64
= mem_cgroup_swappiness_read
,
2009 .write_u64
= mem_cgroup_swappiness_write
,
2013 #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP
2014 static struct cftype memsw_cgroup_files
[] = {
2016 .name
= "memsw.usage_in_bytes",
2017 .private = MEMFILE_PRIVATE(_MEMSWAP
, RES_USAGE
),
2018 .read_u64
= mem_cgroup_read
,
2021 .name
= "memsw.max_usage_in_bytes",
2022 .private = MEMFILE_PRIVATE(_MEMSWAP
, RES_MAX_USAGE
),
2023 .trigger
= mem_cgroup_reset
,
2024 .read_u64
= mem_cgroup_read
,
2027 .name
= "memsw.limit_in_bytes",
2028 .private = MEMFILE_PRIVATE(_MEMSWAP
, RES_LIMIT
),
2029 .write_string
= mem_cgroup_write
,
2030 .read_u64
= mem_cgroup_read
,
2033 .name
= "memsw.failcnt",
2034 .private = MEMFILE_PRIVATE(_MEMSWAP
, RES_FAILCNT
),
2035 .trigger
= mem_cgroup_reset
,
2036 .read_u64
= mem_cgroup_read
,
2040 static int register_memsw_files(struct cgroup
*cont
, struct cgroup_subsys
*ss
)
2042 if (!do_swap_account
)
2044 return cgroup_add_files(cont
, ss
, memsw_cgroup_files
,
2045 ARRAY_SIZE(memsw_cgroup_files
));
2048 static int register_memsw_files(struct cgroup
*cont
, struct cgroup_subsys
*ss
)
2054 static int alloc_mem_cgroup_per_zone_info(struct mem_cgroup
*mem
, int node
)
2056 struct mem_cgroup_per_node
*pn
;
2057 struct mem_cgroup_per_zone
*mz
;
2059 int zone
, tmp
= node
;
2061 * This routine is called against possible nodes.
2062 * But it's BUG to call kmalloc() against offline node.
2064 * TODO: this routine can waste much memory for nodes which will
2065 * never be onlined. It's better to use memory hotplug callback
2068 if (!node_state(node
, N_NORMAL_MEMORY
))
2070 pn
= kmalloc_node(sizeof(*pn
), GFP_KERNEL
, tmp
);
2074 mem
->info
.nodeinfo
[node
] = pn
;
2075 memset(pn
, 0, sizeof(*pn
));
2077 for (zone
= 0; zone
< MAX_NR_ZONES
; zone
++) {
2078 mz
= &pn
->zoneinfo
[zone
];
2080 INIT_LIST_HEAD(&mz
->lists
[l
]);
2085 static void free_mem_cgroup_per_zone_info(struct mem_cgroup
*mem
, int node
)
2087 kfree(mem
->info
.nodeinfo
[node
]);
2090 static int mem_cgroup_size(void)
2092 int cpustat_size
= nr_cpu_ids
* sizeof(struct mem_cgroup_stat_cpu
);
2093 return sizeof(struct mem_cgroup
) + cpustat_size
;
2096 static struct mem_cgroup
*mem_cgroup_alloc(void)
2098 struct mem_cgroup
*mem
;
2099 int size
= mem_cgroup_size();
2101 if (size
< PAGE_SIZE
)
2102 mem
= kmalloc(size
, GFP_KERNEL
);
2104 mem
= vmalloc(size
);
2107 memset(mem
, 0, size
);
2112 * At destroying mem_cgroup, references from swap_cgroup can remain.
2113 * (scanning all at force_empty is too costly...)
2115 * Instead of clearing all references at force_empty, we remember
2116 * the number of reference from swap_cgroup and free mem_cgroup when
2117 * it goes down to 0.
2119 * Removal of cgroup itself succeeds regardless of refs from swap.
2122 static void __mem_cgroup_free(struct mem_cgroup
*mem
)
2126 free_css_id(&mem_cgroup_subsys
, &mem
->css
);
2128 for_each_node_state(node
, N_POSSIBLE
)
2129 free_mem_cgroup_per_zone_info(mem
, node
);
2131 if (mem_cgroup_size() < PAGE_SIZE
)
2137 static void mem_cgroup_get(struct mem_cgroup
*mem
)
2139 atomic_inc(&mem
->refcnt
);
2142 static void mem_cgroup_put(struct mem_cgroup
*mem
)
2144 if (atomic_dec_and_test(&mem
->refcnt
)) {
2145 struct mem_cgroup
*parent
= parent_mem_cgroup(mem
);
2146 __mem_cgroup_free(mem
);
2148 mem_cgroup_put(parent
);
2153 * Returns the parent mem_cgroup in memcgroup hierarchy with hierarchy enabled.
2155 static struct mem_cgroup
*parent_mem_cgroup(struct mem_cgroup
*mem
)
2157 if (!mem
->res
.parent
)
2159 return mem_cgroup_from_res_counter(mem
->res
.parent
, res
);
2162 #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP
2163 static void __init
enable_swap_cgroup(void)
2165 if (!mem_cgroup_disabled() && really_do_swap_account
)
2166 do_swap_account
= 1;
2169 static void __init
enable_swap_cgroup(void)
2174 static struct cgroup_subsys_state
* __ref
2175 mem_cgroup_create(struct cgroup_subsys
*ss
, struct cgroup
*cont
)
2177 struct mem_cgroup
*mem
, *parent
;
2178 long error
= -ENOMEM
;
2181 mem
= mem_cgroup_alloc();
2183 return ERR_PTR(error
);
2185 for_each_node_state(node
, N_POSSIBLE
)
2186 if (alloc_mem_cgroup_per_zone_info(mem
, node
))
2189 if (cont
->parent
== NULL
) {
2190 enable_swap_cgroup();
2193 parent
= mem_cgroup_from_cont(cont
->parent
);
2194 mem
->use_hierarchy
= parent
->use_hierarchy
;
2197 if (parent
&& parent
->use_hierarchy
) {
2198 res_counter_init(&mem
->res
, &parent
->res
);
2199 res_counter_init(&mem
->memsw
, &parent
->memsw
);
2201 * We increment refcnt of the parent to ensure that we can
2202 * safely access it on res_counter_charge/uncharge.
2203 * This refcnt will be decremented when freeing this
2204 * mem_cgroup(see mem_cgroup_put).
2206 mem_cgroup_get(parent
);
2208 res_counter_init(&mem
->res
, NULL
);
2209 res_counter_init(&mem
->memsw
, NULL
);
2211 mem
->last_scanned_child
= 0;
2212 spin_lock_init(&mem
->reclaim_param_lock
);
2215 mem
->swappiness
= get_swappiness(parent
);
2216 atomic_set(&mem
->refcnt
, 1);
2219 __mem_cgroup_free(mem
);
2220 return ERR_PTR(error
);
2223 static int mem_cgroup_pre_destroy(struct cgroup_subsys
*ss
,
2224 struct cgroup
*cont
)
2226 struct mem_cgroup
*mem
= mem_cgroup_from_cont(cont
);
2228 return mem_cgroup_force_empty(mem
, false);
2231 static void mem_cgroup_destroy(struct cgroup_subsys
*ss
,
2232 struct cgroup
*cont
)
2234 struct mem_cgroup
*mem
= mem_cgroup_from_cont(cont
);
2236 mem_cgroup_put(mem
);
2239 static int mem_cgroup_populate(struct cgroup_subsys
*ss
,
2240 struct cgroup
*cont
)
2244 ret
= cgroup_add_files(cont
, ss
, mem_cgroup_files
,
2245 ARRAY_SIZE(mem_cgroup_files
));
2248 ret
= register_memsw_files(cont
, ss
);
2252 static void mem_cgroup_move_task(struct cgroup_subsys
*ss
,
2253 struct cgroup
*cont
,
2254 struct cgroup
*old_cont
,
2255 struct task_struct
*p
)
2257 mutex_lock(&memcg_tasklist
);
2259 * FIXME: It's better to move charges of this process from old
2260 * memcg to new memcg. But it's just on TODO-List now.
2262 mutex_unlock(&memcg_tasklist
);
2265 struct cgroup_subsys mem_cgroup_subsys
= {
2267 .subsys_id
= mem_cgroup_subsys_id
,
2268 .create
= mem_cgroup_create
,
2269 .pre_destroy
= mem_cgroup_pre_destroy
,
2270 .destroy
= mem_cgroup_destroy
,
2271 .populate
= mem_cgroup_populate
,
2272 .attach
= mem_cgroup_move_task
,
2277 #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP
2279 static int __init
disable_swap_account(char *s
)
2281 really_do_swap_account
= 0;
2284 __setup("noswapaccount", disable_swap_account
);