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/rbtree.h>
33 #include <linux/slab.h>
34 #include <linux/swap.h>
35 #include <linux/spinlock.h>
37 #include <linux/seq_file.h>
38 #include <linux/vmalloc.h>
39 #include <linux/mm_inline.h>
40 #include <linux/page_cgroup.h>
41 #include <linux/cpu.h>
44 #include <asm/uaccess.h>
46 struct cgroup_subsys mem_cgroup_subsys __read_mostly;
47 #define MEM_CGROUP_RECLAIM_RETRIES 5
48 struct mem_cgroup *root_mem_cgroup __read_mostly;
50 #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP
51 /* Turned on only when memory cgroup is enabled && really_do_swap_account = 1 */
52 int do_swap_account __read_mostly;
53 static int really_do_swap_account __initdata = 1; /* for remember boot option*/
55 #define do_swap_account (0)
58 #define SOFTLIMIT_EVENTS_THRESH (1000)
61 * Statistics for memory cgroup.
63 enum mem_cgroup_stat_index {
65 * For MEM_CONTAINER_TYPE_ALL, usage = pagecache + rss.
67 MEM_CGROUP_STAT_CACHE, /* # of pages charged as cache */
68 MEM_CGROUP_STAT_RSS, /* # of pages charged as anon rss */
69 MEM_CGROUP_STAT_FILE_MAPPED, /* # of pages charged as file rss */
70 MEM_CGROUP_STAT_PGPGIN_COUNT, /* # of pages paged in */
71 MEM_CGROUP_STAT_PGPGOUT_COUNT, /* # of pages paged out */
72 MEM_CGROUP_STAT_EVENTS, /* sum of pagein + pageout for internal use */
73 MEM_CGROUP_STAT_SWAPOUT, /* # of pages, swapped out */
75 MEM_CGROUP_STAT_NSTATS,
78 struct mem_cgroup_stat_cpu {
79 s64 count[MEM_CGROUP_STAT_NSTATS];
80 } ____cacheline_aligned_in_smp;
82 struct mem_cgroup_stat {
83 struct mem_cgroup_stat_cpu cpustat[0];
87 __mem_cgroup_stat_reset_safe(struct mem_cgroup_stat_cpu *stat,
88 enum mem_cgroup_stat_index idx)
94 __mem_cgroup_stat_read_local(struct mem_cgroup_stat_cpu *stat,
95 enum mem_cgroup_stat_index idx)
97 return stat->count[idx];
101 * For accounting under irq disable, no need for increment preempt count.
103 static inline void __mem_cgroup_stat_add_safe(struct mem_cgroup_stat_cpu *stat,
104 enum mem_cgroup_stat_index idx, int val)
106 stat->count[idx] += val;
109 static s64 mem_cgroup_read_stat(struct mem_cgroup_stat *stat,
110 enum mem_cgroup_stat_index idx)
114 for_each_possible_cpu(cpu)
115 ret += stat->cpustat[cpu].count[idx];
119 static s64 mem_cgroup_local_usage(struct mem_cgroup_stat *stat)
123 ret = mem_cgroup_read_stat(stat, MEM_CGROUP_STAT_CACHE);
124 ret += mem_cgroup_read_stat(stat, MEM_CGROUP_STAT_RSS);
129 * per-zone information in memory controller.
131 struct mem_cgroup_per_zone {
133 * spin_lock to protect the per cgroup LRU
135 struct list_head lists[NR_LRU_LISTS];
136 unsigned long count[NR_LRU_LISTS];
138 struct zone_reclaim_stat reclaim_stat;
139 struct rb_node tree_node; /* RB tree node */
140 unsigned long long usage_in_excess;/* Set to the value by which */
141 /* the soft limit is exceeded*/
143 struct mem_cgroup *mem; /* Back pointer, we cannot */
144 /* use container_of */
146 /* Macro for accessing counter */
147 #define MEM_CGROUP_ZSTAT(mz, idx) ((mz)->count[(idx)])
149 struct mem_cgroup_per_node {
150 struct mem_cgroup_per_zone zoneinfo[MAX_NR_ZONES];
153 struct mem_cgroup_lru_info {
154 struct mem_cgroup_per_node *nodeinfo[MAX_NUMNODES];
158 * Cgroups above their limits are maintained in a RB-Tree, independent of
159 * their hierarchy representation
162 struct mem_cgroup_tree_per_zone {
163 struct rb_root rb_root;
167 struct mem_cgroup_tree_per_node {
168 struct mem_cgroup_tree_per_zone rb_tree_per_zone[MAX_NR_ZONES];
171 struct mem_cgroup_tree {
172 struct mem_cgroup_tree_per_node *rb_tree_per_node[MAX_NUMNODES];
175 static struct mem_cgroup_tree soft_limit_tree __read_mostly;
178 * The memory controller data structure. The memory controller controls both
179 * page cache and RSS per cgroup. We would eventually like to provide
180 * statistics based on the statistics developed by Rik Van Riel for clock-pro,
181 * to help the administrator determine what knobs to tune.
183 * TODO: Add a water mark for the memory controller. Reclaim will begin when
184 * we hit the water mark. May be even add a low water mark, such that
185 * no reclaim occurs from a cgroup at it's low water mark, this is
186 * a feature that will be implemented much later in the future.
189 struct cgroup_subsys_state css;
191 * the counter to account for memory usage
193 struct res_counter res;
195 * the counter to account for mem+swap usage.
197 struct res_counter memsw;
199 * Per cgroup active and inactive list, similar to the
200 * per zone LRU lists.
202 struct mem_cgroup_lru_info info;
205 protect against reclaim related member.
207 spinlock_t reclaim_param_lock;
209 int prev_priority; /* for recording reclaim priority */
212 * While reclaiming in a hierarchy, we cache the last child we
215 int last_scanned_child;
217 * Should the accounting and control be hierarchical, per subtree?
220 unsigned long last_oom_jiffies;
223 unsigned int swappiness;
225 /* set when res.limit == memsw.limit */
226 bool memsw_is_minimum;
229 * statistics. This must be placed at the end of memcg.
231 struct mem_cgroup_stat stat;
235 * Maximum loops in mem_cgroup_hierarchical_reclaim(), used for soft
236 * limit reclaim to prevent infinite loops, if they ever occur.
238 #define MEM_CGROUP_MAX_RECLAIM_LOOPS (100)
239 #define MEM_CGROUP_MAX_SOFT_LIMIT_RECLAIM_LOOPS (2)
242 MEM_CGROUP_CHARGE_TYPE_CACHE = 0,
243 MEM_CGROUP_CHARGE_TYPE_MAPPED,
244 MEM_CGROUP_CHARGE_TYPE_SHMEM, /* used by page migration of shmem */
245 MEM_CGROUP_CHARGE_TYPE_FORCE, /* used by force_empty */
246 MEM_CGROUP_CHARGE_TYPE_SWAPOUT, /* for accounting swapcache */
247 MEM_CGROUP_CHARGE_TYPE_DROP, /* a page was unused swap cache */
251 /* only for here (for easy reading.) */
252 #define PCGF_CACHE (1UL << PCG_CACHE)
253 #define PCGF_USED (1UL << PCG_USED)
254 #define PCGF_LOCK (1UL << PCG_LOCK)
255 /* Not used, but added here for completeness */
256 #define PCGF_ACCT (1UL << PCG_ACCT)
258 /* for encoding cft->private value on file */
261 #define MEMFILE_PRIVATE(x, val) (((x) << 16) | (val))
262 #define MEMFILE_TYPE(val) (((val) >> 16) & 0xffff)
263 #define MEMFILE_ATTR(val) ((val) & 0xffff)
266 * Reclaim flags for mem_cgroup_hierarchical_reclaim
268 #define MEM_CGROUP_RECLAIM_NOSWAP_BIT 0x0
269 #define MEM_CGROUP_RECLAIM_NOSWAP (1 << MEM_CGROUP_RECLAIM_NOSWAP_BIT)
270 #define MEM_CGROUP_RECLAIM_SHRINK_BIT 0x1
271 #define MEM_CGROUP_RECLAIM_SHRINK (1 << MEM_CGROUP_RECLAIM_SHRINK_BIT)
272 #define MEM_CGROUP_RECLAIM_SOFT_BIT 0x2
273 #define MEM_CGROUP_RECLAIM_SOFT (1 << MEM_CGROUP_RECLAIM_SOFT_BIT)
275 static void mem_cgroup_get(struct mem_cgroup *mem);
276 static void mem_cgroup_put(struct mem_cgroup *mem);
277 static struct mem_cgroup *parent_mem_cgroup(struct mem_cgroup *mem);
278 static void drain_all_stock_async(void);
280 static struct mem_cgroup_per_zone *
281 mem_cgroup_zoneinfo(struct mem_cgroup *mem, int nid, int zid)
283 return &mem->info.nodeinfo[nid]->zoneinfo[zid];
286 static struct mem_cgroup_per_zone *
287 page_cgroup_zoneinfo(struct page_cgroup *pc)
289 struct mem_cgroup *mem = pc->mem_cgroup;
290 int nid = page_cgroup_nid(pc);
291 int zid = page_cgroup_zid(pc);
296 return mem_cgroup_zoneinfo(mem, nid, zid);
299 static struct mem_cgroup_tree_per_zone *
300 soft_limit_tree_node_zone(int nid, int zid)
302 return &soft_limit_tree.rb_tree_per_node[nid]->rb_tree_per_zone[zid];
305 static struct mem_cgroup_tree_per_zone *
306 soft_limit_tree_from_page(struct page *page)
308 int nid = page_to_nid(page);
309 int zid = page_zonenum(page);
311 return &soft_limit_tree.rb_tree_per_node[nid]->rb_tree_per_zone[zid];
315 __mem_cgroup_insert_exceeded(struct mem_cgroup *mem,
316 struct mem_cgroup_per_zone *mz,
317 struct mem_cgroup_tree_per_zone *mctz,
318 unsigned long long new_usage_in_excess)
320 struct rb_node **p = &mctz->rb_root.rb_node;
321 struct rb_node *parent = NULL;
322 struct mem_cgroup_per_zone *mz_node;
327 mz->usage_in_excess = new_usage_in_excess;
328 if (!mz->usage_in_excess)
332 mz_node = rb_entry(parent, struct mem_cgroup_per_zone,
334 if (mz->usage_in_excess < mz_node->usage_in_excess)
337 * We can't avoid mem cgroups that are over their soft
338 * limit by the same amount
340 else if (mz->usage_in_excess >= mz_node->usage_in_excess)
343 rb_link_node(&mz->tree_node, parent, p);
344 rb_insert_color(&mz->tree_node, &mctz->rb_root);
349 __mem_cgroup_remove_exceeded(struct mem_cgroup *mem,
350 struct mem_cgroup_per_zone *mz,
351 struct mem_cgroup_tree_per_zone *mctz)
355 rb_erase(&mz->tree_node, &mctz->rb_root);
360 mem_cgroup_remove_exceeded(struct mem_cgroup *mem,
361 struct mem_cgroup_per_zone *mz,
362 struct mem_cgroup_tree_per_zone *mctz)
364 spin_lock(&mctz->lock);
365 __mem_cgroup_remove_exceeded(mem, mz, mctz);
366 spin_unlock(&mctz->lock);
369 static bool mem_cgroup_soft_limit_check(struct mem_cgroup *mem)
374 struct mem_cgroup_stat_cpu *cpustat;
377 cpustat = &mem->stat.cpustat[cpu];
378 val = __mem_cgroup_stat_read_local(cpustat, MEM_CGROUP_STAT_EVENTS);
379 if (unlikely(val > SOFTLIMIT_EVENTS_THRESH)) {
380 __mem_cgroup_stat_reset_safe(cpustat, MEM_CGROUP_STAT_EVENTS);
387 static void mem_cgroup_update_tree(struct mem_cgroup *mem, struct page *page)
389 unsigned long long excess;
390 struct mem_cgroup_per_zone *mz;
391 struct mem_cgroup_tree_per_zone *mctz;
392 int nid = page_to_nid(page);
393 int zid = page_zonenum(page);
394 mctz = soft_limit_tree_from_page(page);
397 * Necessary to update all ancestors when hierarchy is used.
398 * because their event counter is not touched.
400 for (; mem; mem = parent_mem_cgroup(mem)) {
401 mz = mem_cgroup_zoneinfo(mem, nid, zid);
402 excess = res_counter_soft_limit_excess(&mem->res);
404 * We have to update the tree if mz is on RB-tree or
405 * mem is over its softlimit.
407 if (excess || mz->on_tree) {
408 spin_lock(&mctz->lock);
409 /* if on-tree, remove it */
411 __mem_cgroup_remove_exceeded(mem, mz, mctz);
413 * Insert again. mz->usage_in_excess will be updated.
414 * If excess is 0, no tree ops.
416 __mem_cgroup_insert_exceeded(mem, mz, mctz, excess);
417 spin_unlock(&mctz->lock);
422 static void mem_cgroup_remove_from_trees(struct mem_cgroup *mem)
425 struct mem_cgroup_per_zone *mz;
426 struct mem_cgroup_tree_per_zone *mctz;
428 for_each_node_state(node, N_POSSIBLE) {
429 for (zone = 0; zone < MAX_NR_ZONES; zone++) {
430 mz = mem_cgroup_zoneinfo(mem, node, zone);
431 mctz = soft_limit_tree_node_zone(node, zone);
432 mem_cgroup_remove_exceeded(mem, mz, mctz);
437 static inline unsigned long mem_cgroup_get_excess(struct mem_cgroup *mem)
439 return res_counter_soft_limit_excess(&mem->res) >> PAGE_SHIFT;
442 static struct mem_cgroup_per_zone *
443 __mem_cgroup_largest_soft_limit_node(struct mem_cgroup_tree_per_zone *mctz)
445 struct rb_node *rightmost = NULL;
446 struct mem_cgroup_per_zone *mz;
450 rightmost = rb_last(&mctz->rb_root);
452 goto done; /* Nothing to reclaim from */
454 mz = rb_entry(rightmost, struct mem_cgroup_per_zone, tree_node);
456 * Remove the node now but someone else can add it back,
457 * we will to add it back at the end of reclaim to its correct
458 * position in the tree.
460 __mem_cgroup_remove_exceeded(mz->mem, mz, mctz);
461 if (!res_counter_soft_limit_excess(&mz->mem->res) ||
462 !css_tryget(&mz->mem->css))
468 static struct mem_cgroup_per_zone *
469 mem_cgroup_largest_soft_limit_node(struct mem_cgroup_tree_per_zone *mctz)
471 struct mem_cgroup_per_zone *mz;
473 spin_lock(&mctz->lock);
474 mz = __mem_cgroup_largest_soft_limit_node(mctz);
475 spin_unlock(&mctz->lock);
479 static void mem_cgroup_swap_statistics(struct mem_cgroup *mem,
482 int val = (charge) ? 1 : -1;
483 struct mem_cgroup_stat *stat = &mem->stat;
484 struct mem_cgroup_stat_cpu *cpustat;
487 cpustat = &stat->cpustat[cpu];
488 __mem_cgroup_stat_add_safe(cpustat, MEM_CGROUP_STAT_SWAPOUT, val);
492 static void mem_cgroup_charge_statistics(struct mem_cgroup *mem,
493 struct page_cgroup *pc,
496 int val = (charge) ? 1 : -1;
497 struct mem_cgroup_stat *stat = &mem->stat;
498 struct mem_cgroup_stat_cpu *cpustat;
501 cpustat = &stat->cpustat[cpu];
502 if (PageCgroupCache(pc))
503 __mem_cgroup_stat_add_safe(cpustat, MEM_CGROUP_STAT_CACHE, val);
505 __mem_cgroup_stat_add_safe(cpustat, MEM_CGROUP_STAT_RSS, val);
508 __mem_cgroup_stat_add_safe(cpustat,
509 MEM_CGROUP_STAT_PGPGIN_COUNT, 1);
511 __mem_cgroup_stat_add_safe(cpustat,
512 MEM_CGROUP_STAT_PGPGOUT_COUNT, 1);
513 __mem_cgroup_stat_add_safe(cpustat, MEM_CGROUP_STAT_EVENTS, 1);
517 static unsigned long mem_cgroup_get_local_zonestat(struct mem_cgroup *mem,
521 struct mem_cgroup_per_zone *mz;
524 for_each_online_node(nid)
525 for (zid = 0; zid < MAX_NR_ZONES; zid++) {
526 mz = mem_cgroup_zoneinfo(mem, nid, zid);
527 total += MEM_CGROUP_ZSTAT(mz, idx);
532 static struct mem_cgroup *mem_cgroup_from_cont(struct cgroup *cont)
534 return container_of(cgroup_subsys_state(cont,
535 mem_cgroup_subsys_id), struct mem_cgroup,
539 struct mem_cgroup *mem_cgroup_from_task(struct task_struct *p)
542 * mm_update_next_owner() may clear mm->owner to NULL
543 * if it races with swapoff, page migration, etc.
544 * So this can be called with p == NULL.
549 return container_of(task_subsys_state(p, mem_cgroup_subsys_id),
550 struct mem_cgroup, css);
553 static struct mem_cgroup *try_get_mem_cgroup_from_mm(struct mm_struct *mm)
555 struct mem_cgroup *mem = NULL;
560 * Because we have no locks, mm->owner's may be being moved to other
561 * cgroup. We use css_tryget() here even if this looks
562 * pessimistic (rather than adding locks here).
566 mem = mem_cgroup_from_task(rcu_dereference(mm->owner));
569 } while (!css_tryget(&mem->css));
575 * Call callback function against all cgroup under hierarchy tree.
577 static int mem_cgroup_walk_tree(struct mem_cgroup *root, void *data,
578 int (*func)(struct mem_cgroup *, void *))
580 int found, ret, nextid;
581 struct cgroup_subsys_state *css;
582 struct mem_cgroup *mem;
584 if (!root->use_hierarchy)
585 return (*func)(root, data);
593 css = css_get_next(&mem_cgroup_subsys, nextid, &root->css,
595 if (css && css_tryget(css))
596 mem = container_of(css, struct mem_cgroup, css);
600 ret = (*func)(mem, data);
604 } while (!ret && css);
609 static inline bool mem_cgroup_is_root(struct mem_cgroup *mem)
611 return (mem == root_mem_cgroup);
615 * Following LRU functions are allowed to be used without PCG_LOCK.
616 * Operations are called by routine of global LRU independently from memcg.
617 * What we have to take care of here is validness of pc->mem_cgroup.
619 * Changes to pc->mem_cgroup happens when
622 * In typical case, "charge" is done before add-to-lru. Exception is SwapCache.
623 * It is added to LRU before charge.
624 * If PCG_USED bit is not set, page_cgroup is not added to this private LRU.
625 * When moving account, the page is not on LRU. It's isolated.
628 void mem_cgroup_del_lru_list(struct page *page, enum lru_list lru)
630 struct page_cgroup *pc;
631 struct mem_cgroup_per_zone *mz;
633 if (mem_cgroup_disabled())
635 pc = lookup_page_cgroup(page);
636 /* can happen while we handle swapcache. */
637 if (!TestClearPageCgroupAcctLRU(pc))
639 VM_BUG_ON(!pc->mem_cgroup);
641 * We don't check PCG_USED bit. It's cleared when the "page" is finally
642 * removed from global LRU.
644 mz = page_cgroup_zoneinfo(pc);
645 MEM_CGROUP_ZSTAT(mz, lru) -= 1;
646 if (mem_cgroup_is_root(pc->mem_cgroup))
648 VM_BUG_ON(list_empty(&pc->lru));
649 list_del_init(&pc->lru);
653 void mem_cgroup_del_lru(struct page *page)
655 mem_cgroup_del_lru_list(page, page_lru(page));
658 void mem_cgroup_rotate_lru_list(struct page *page, enum lru_list lru)
660 struct mem_cgroup_per_zone *mz;
661 struct page_cgroup *pc;
663 if (mem_cgroup_disabled())
666 pc = lookup_page_cgroup(page);
668 * Used bit is set without atomic ops but after smp_wmb().
669 * For making pc->mem_cgroup visible, insert smp_rmb() here.
672 /* unused or root page is not rotated. */
673 if (!PageCgroupUsed(pc) || mem_cgroup_is_root(pc->mem_cgroup))
675 mz = page_cgroup_zoneinfo(pc);
676 list_move(&pc->lru, &mz->lists[lru]);
679 void mem_cgroup_add_lru_list(struct page *page, enum lru_list lru)
681 struct page_cgroup *pc;
682 struct mem_cgroup_per_zone *mz;
684 if (mem_cgroup_disabled())
686 pc = lookup_page_cgroup(page);
687 VM_BUG_ON(PageCgroupAcctLRU(pc));
689 * Used bit is set without atomic ops but after smp_wmb().
690 * For making pc->mem_cgroup visible, insert smp_rmb() here.
693 if (!PageCgroupUsed(pc))
696 mz = page_cgroup_zoneinfo(pc);
697 MEM_CGROUP_ZSTAT(mz, lru) += 1;
698 SetPageCgroupAcctLRU(pc);
699 if (mem_cgroup_is_root(pc->mem_cgroup))
701 list_add(&pc->lru, &mz->lists[lru]);
705 * At handling SwapCache, pc->mem_cgroup may be changed while it's linked to
706 * lru because the page may.be reused after it's fully uncharged (because of
707 * SwapCache behavior).To handle that, unlink page_cgroup from LRU when charge
708 * it again. This function is only used to charge SwapCache. It's done under
709 * lock_page and expected that zone->lru_lock is never held.
711 static void mem_cgroup_lru_del_before_commit_swapcache(struct page *page)
714 struct zone *zone = page_zone(page);
715 struct page_cgroup *pc = lookup_page_cgroup(page);
717 spin_lock_irqsave(&zone->lru_lock, flags);
719 * Forget old LRU when this page_cgroup is *not* used. This Used bit
720 * is guarded by lock_page() because the page is SwapCache.
722 if (!PageCgroupUsed(pc))
723 mem_cgroup_del_lru_list(page, page_lru(page));
724 spin_unlock_irqrestore(&zone->lru_lock, flags);
727 static void mem_cgroup_lru_add_after_commit_swapcache(struct page *page)
730 struct zone *zone = page_zone(page);
731 struct page_cgroup *pc = lookup_page_cgroup(page);
733 spin_lock_irqsave(&zone->lru_lock, flags);
734 /* link when the page is linked to LRU but page_cgroup isn't */
735 if (PageLRU(page) && !PageCgroupAcctLRU(pc))
736 mem_cgroup_add_lru_list(page, page_lru(page));
737 spin_unlock_irqrestore(&zone->lru_lock, flags);
741 void mem_cgroup_move_lists(struct page *page,
742 enum lru_list from, enum lru_list to)
744 if (mem_cgroup_disabled())
746 mem_cgroup_del_lru_list(page, from);
747 mem_cgroup_add_lru_list(page, to);
750 int task_in_mem_cgroup(struct task_struct *task, const struct mem_cgroup *mem)
753 struct mem_cgroup *curr = NULL;
757 curr = try_get_mem_cgroup_from_mm(task->mm);
763 * We should check use_hierarchy of "mem" not "curr". Because checking
764 * use_hierarchy of "curr" here make this function true if hierarchy is
765 * enabled in "curr" and "curr" is a child of "mem" in *cgroup*
766 * hierarchy(even if use_hierarchy is disabled in "mem").
768 if (mem->use_hierarchy)
769 ret = css_is_ancestor(&curr->css, &mem->css);
777 * prev_priority control...this will be used in memory reclaim path.
779 int mem_cgroup_get_reclaim_priority(struct mem_cgroup *mem)
783 spin_lock(&mem->reclaim_param_lock);
784 prev_priority = mem->prev_priority;
785 spin_unlock(&mem->reclaim_param_lock);
787 return prev_priority;
790 void mem_cgroup_note_reclaim_priority(struct mem_cgroup *mem, int priority)
792 spin_lock(&mem->reclaim_param_lock);
793 if (priority < mem->prev_priority)
794 mem->prev_priority = priority;
795 spin_unlock(&mem->reclaim_param_lock);
798 void mem_cgroup_record_reclaim_priority(struct mem_cgroup *mem, int priority)
800 spin_lock(&mem->reclaim_param_lock);
801 mem->prev_priority = priority;
802 spin_unlock(&mem->reclaim_param_lock);
805 static int calc_inactive_ratio(struct mem_cgroup *memcg, unsigned long *present_pages)
807 unsigned long active;
808 unsigned long inactive;
810 unsigned long inactive_ratio;
812 inactive = mem_cgroup_get_local_zonestat(memcg, LRU_INACTIVE_ANON);
813 active = mem_cgroup_get_local_zonestat(memcg, LRU_ACTIVE_ANON);
815 gb = (inactive + active) >> (30 - PAGE_SHIFT);
817 inactive_ratio = int_sqrt(10 * gb);
822 present_pages[0] = inactive;
823 present_pages[1] = active;
826 return inactive_ratio;
829 int mem_cgroup_inactive_anon_is_low(struct mem_cgroup *memcg)
831 unsigned long active;
832 unsigned long inactive;
833 unsigned long present_pages[2];
834 unsigned long inactive_ratio;
836 inactive_ratio = calc_inactive_ratio(memcg, present_pages);
838 inactive = present_pages[0];
839 active = present_pages[1];
841 if (inactive * inactive_ratio < active)
847 int mem_cgroup_inactive_file_is_low(struct mem_cgroup *memcg)
849 unsigned long active;
850 unsigned long inactive;
852 inactive = mem_cgroup_get_local_zonestat(memcg, LRU_INACTIVE_FILE);
853 active = mem_cgroup_get_local_zonestat(memcg, LRU_ACTIVE_FILE);
855 return (active > inactive);
858 unsigned long mem_cgroup_zone_nr_pages(struct mem_cgroup *memcg,
862 int nid = zone->zone_pgdat->node_id;
863 int zid = zone_idx(zone);
864 struct mem_cgroup_per_zone *mz = mem_cgroup_zoneinfo(memcg, nid, zid);
866 return MEM_CGROUP_ZSTAT(mz, lru);
869 struct zone_reclaim_stat *mem_cgroup_get_reclaim_stat(struct mem_cgroup *memcg,
872 int nid = zone->zone_pgdat->node_id;
873 int zid = zone_idx(zone);
874 struct mem_cgroup_per_zone *mz = mem_cgroup_zoneinfo(memcg, nid, zid);
876 return &mz->reclaim_stat;
879 struct zone_reclaim_stat *
880 mem_cgroup_get_reclaim_stat_from_page(struct page *page)
882 struct page_cgroup *pc;
883 struct mem_cgroup_per_zone *mz;
885 if (mem_cgroup_disabled())
888 pc = lookup_page_cgroup(page);
890 * Used bit is set without atomic ops but after smp_wmb().
891 * For making pc->mem_cgroup visible, insert smp_rmb() here.
894 if (!PageCgroupUsed(pc))
897 mz = page_cgroup_zoneinfo(pc);
901 return &mz->reclaim_stat;
904 unsigned long mem_cgroup_isolate_pages(unsigned long nr_to_scan,
905 struct list_head *dst,
906 unsigned long *scanned, int order,
907 int mode, struct zone *z,
908 struct mem_cgroup *mem_cont,
909 int active, int file)
911 unsigned long nr_taken = 0;
915 struct list_head *src;
916 struct page_cgroup *pc, *tmp;
917 int nid = z->zone_pgdat->node_id;
918 int zid = zone_idx(z);
919 struct mem_cgroup_per_zone *mz;
920 int lru = LRU_FILE * file + active;
924 mz = mem_cgroup_zoneinfo(mem_cont, nid, zid);
925 src = &mz->lists[lru];
928 list_for_each_entry_safe_reverse(pc, tmp, src, lru) {
929 if (scan >= nr_to_scan)
933 if (unlikely(!PageCgroupUsed(pc)))
935 if (unlikely(!PageLRU(page)))
939 ret = __isolate_lru_page(page, mode, file);
942 list_move(&page->lru, dst);
943 mem_cgroup_del_lru(page);
947 /* we don't affect global LRU but rotate in our LRU */
948 mem_cgroup_rotate_lru_list(page, page_lru(page));
959 #define mem_cgroup_from_res_counter(counter, member) \
960 container_of(counter, struct mem_cgroup, member)
962 static bool mem_cgroup_check_under_limit(struct mem_cgroup *mem)
964 if (do_swap_account) {
965 if (res_counter_check_under_limit(&mem->res) &&
966 res_counter_check_under_limit(&mem->memsw))
969 if (res_counter_check_under_limit(&mem->res))
974 static unsigned int get_swappiness(struct mem_cgroup *memcg)
976 struct cgroup *cgrp = memcg->css.cgroup;
977 unsigned int swappiness;
980 if (cgrp->parent == NULL)
981 return vm_swappiness;
983 spin_lock(&memcg->reclaim_param_lock);
984 swappiness = memcg->swappiness;
985 spin_unlock(&memcg->reclaim_param_lock);
990 static int mem_cgroup_count_children_cb(struct mem_cgroup *mem, void *data)
998 * mem_cgroup_print_mem_info: Called from OOM with tasklist_lock held in read mode.
999 * @memcg: The memory cgroup that went over limit
1000 * @p: Task that is going to be killed
1002 * NOTE: @memcg and @p's mem_cgroup can be different when hierarchy is
1005 void mem_cgroup_print_oom_info(struct mem_cgroup *memcg, struct task_struct *p)
1007 struct cgroup *task_cgrp;
1008 struct cgroup *mem_cgrp;
1010 * Need a buffer in BSS, can't rely on allocations. The code relies
1011 * on the assumption that OOM is serialized for memory controller.
1012 * If this assumption is broken, revisit this code.
1014 static char memcg_name[PATH_MAX];
1023 mem_cgrp = memcg->css.cgroup;
1024 task_cgrp = task_cgroup(p, mem_cgroup_subsys_id);
1026 ret = cgroup_path(task_cgrp, memcg_name, PATH_MAX);
1029 * Unfortunately, we are unable to convert to a useful name
1030 * But we'll still print out the usage information
1037 printk(KERN_INFO "Task in %s killed", memcg_name);
1040 ret = cgroup_path(mem_cgrp, memcg_name, PATH_MAX);
1048 * Continues from above, so we don't need an KERN_ level
1050 printk(KERN_CONT " as a result of limit of %s\n", memcg_name);
1053 printk(KERN_INFO "memory: usage %llukB, limit %llukB, failcnt %llu\n",
1054 res_counter_read_u64(&memcg->res, RES_USAGE) >> 10,
1055 res_counter_read_u64(&memcg->res, RES_LIMIT) >> 10,
1056 res_counter_read_u64(&memcg->res, RES_FAILCNT));
1057 printk(KERN_INFO "memory+swap: usage %llukB, limit %llukB, "
1059 res_counter_read_u64(&memcg->memsw, RES_USAGE) >> 10,
1060 res_counter_read_u64(&memcg->memsw, RES_LIMIT) >> 10,
1061 res_counter_read_u64(&memcg->memsw, RES_FAILCNT));
1065 * This function returns the number of memcg under hierarchy tree. Returns
1066 * 1(self count) if no children.
1068 static int mem_cgroup_count_children(struct mem_cgroup *mem)
1071 mem_cgroup_walk_tree(mem, &num, mem_cgroup_count_children_cb);
1076 * Visit the first child (need not be the first child as per the ordering
1077 * of the cgroup list, since we track last_scanned_child) of @mem and use
1078 * that to reclaim free pages from.
1080 static struct mem_cgroup *
1081 mem_cgroup_select_victim(struct mem_cgroup *root_mem)
1083 struct mem_cgroup *ret = NULL;
1084 struct cgroup_subsys_state *css;
1087 if (!root_mem->use_hierarchy) {
1088 css_get(&root_mem->css);
1094 nextid = root_mem->last_scanned_child + 1;
1095 css = css_get_next(&mem_cgroup_subsys, nextid, &root_mem->css,
1097 if (css && css_tryget(css))
1098 ret = container_of(css, struct mem_cgroup, css);
1101 /* Updates scanning parameter */
1102 spin_lock(&root_mem->reclaim_param_lock);
1104 /* this means start scan from ID:1 */
1105 root_mem->last_scanned_child = 0;
1107 root_mem->last_scanned_child = found;
1108 spin_unlock(&root_mem->reclaim_param_lock);
1115 * Scan the hierarchy if needed to reclaim memory. We remember the last child
1116 * we reclaimed from, so that we don't end up penalizing one child extensively
1117 * based on its position in the children list.
1119 * root_mem is the original ancestor that we've been reclaim from.
1121 * We give up and return to the caller when we visit root_mem twice.
1122 * (other groups can be removed while we're walking....)
1124 * If shrink==true, for avoiding to free too much, this returns immedieately.
1126 static int mem_cgroup_hierarchical_reclaim(struct mem_cgroup *root_mem,
1129 unsigned long reclaim_options)
1131 struct mem_cgroup *victim;
1134 bool noswap = reclaim_options & MEM_CGROUP_RECLAIM_NOSWAP;
1135 bool shrink = reclaim_options & MEM_CGROUP_RECLAIM_SHRINK;
1136 bool check_soft = reclaim_options & MEM_CGROUP_RECLAIM_SOFT;
1137 unsigned long excess = mem_cgroup_get_excess(root_mem);
1139 /* If memsw_is_minimum==1, swap-out is of-no-use. */
1140 if (root_mem->memsw_is_minimum)
1144 victim = mem_cgroup_select_victim(root_mem);
1145 if (victim == root_mem) {
1148 drain_all_stock_async();
1151 * If we have not been able to reclaim
1152 * anything, it might because there are
1153 * no reclaimable pages under this hierarchy
1155 if (!check_soft || !total) {
1156 css_put(&victim->css);
1160 * We want to do more targetted reclaim.
1161 * excess >> 2 is not to excessive so as to
1162 * reclaim too much, nor too less that we keep
1163 * coming back to reclaim from this cgroup
1165 if (total >= (excess >> 2) ||
1166 (loop > MEM_CGROUP_MAX_RECLAIM_LOOPS)) {
1167 css_put(&victim->css);
1172 if (!mem_cgroup_local_usage(&victim->stat)) {
1173 /* this cgroup's local usage == 0 */
1174 css_put(&victim->css);
1177 /* we use swappiness of local cgroup */
1179 ret = mem_cgroup_shrink_node_zone(victim, gfp_mask,
1180 noswap, get_swappiness(victim), zone,
1181 zone->zone_pgdat->node_id);
1183 ret = try_to_free_mem_cgroup_pages(victim, gfp_mask,
1184 noswap, get_swappiness(victim));
1185 css_put(&victim->css);
1187 * At shrinking usage, we can't check we should stop here or
1188 * reclaim more. It's depends on callers. last_scanned_child
1189 * will work enough for keeping fairness under tree.
1195 if (res_counter_check_under_soft_limit(&root_mem->res))
1197 } else if (mem_cgroup_check_under_limit(root_mem))
1203 bool mem_cgroup_oom_called(struct task_struct *task)
1206 struct mem_cgroup *mem;
1207 struct mm_struct *mm;
1213 mem = mem_cgroup_from_task(rcu_dereference(mm->owner));
1214 if (mem && time_before(jiffies, mem->last_oom_jiffies + HZ/10))
1220 static int record_last_oom_cb(struct mem_cgroup *mem, void *data)
1222 mem->last_oom_jiffies = jiffies;
1226 static void record_last_oom(struct mem_cgroup *mem)
1228 mem_cgroup_walk_tree(mem, NULL, record_last_oom_cb);
1232 * Currently used to update mapped file statistics, but the routine can be
1233 * generalized to update other statistics as well.
1235 void mem_cgroup_update_file_mapped(struct page *page, int val)
1237 struct mem_cgroup *mem;
1238 struct mem_cgroup_stat *stat;
1239 struct mem_cgroup_stat_cpu *cpustat;
1241 struct page_cgroup *pc;
1243 pc = lookup_page_cgroup(page);
1247 lock_page_cgroup(pc);
1248 mem = pc->mem_cgroup;
1252 if (!PageCgroupUsed(pc))
1256 * Preemption is already disabled, we don't need get_cpu()
1258 cpu = smp_processor_id();
1260 cpustat = &stat->cpustat[cpu];
1262 __mem_cgroup_stat_add_safe(cpustat, MEM_CGROUP_STAT_FILE_MAPPED, val);
1264 unlock_page_cgroup(pc);
1268 * size of first charge trial. "32" comes from vmscan.c's magic value.
1269 * TODO: maybe necessary to use big numbers in big irons.
1271 #define CHARGE_SIZE (32 * PAGE_SIZE)
1272 struct memcg_stock_pcp {
1273 struct mem_cgroup *cached; /* this never be root cgroup */
1275 struct work_struct work;
1277 static DEFINE_PER_CPU(struct memcg_stock_pcp, memcg_stock);
1278 static atomic_t memcg_drain_count;
1281 * Try to consume stocked charge on this cpu. If success, PAGE_SIZE is consumed
1282 * from local stock and true is returned. If the stock is 0 or charges from a
1283 * cgroup which is not current target, returns false. This stock will be
1286 static bool consume_stock(struct mem_cgroup *mem)
1288 struct memcg_stock_pcp *stock;
1291 stock = &get_cpu_var(memcg_stock);
1292 if (mem == stock->cached && stock->charge)
1293 stock->charge -= PAGE_SIZE;
1294 else /* need to call res_counter_charge */
1296 put_cpu_var(memcg_stock);
1301 * Returns stocks cached in percpu to res_counter and reset cached information.
1303 static void drain_stock(struct memcg_stock_pcp *stock)
1305 struct mem_cgroup *old = stock->cached;
1307 if (stock->charge) {
1308 res_counter_uncharge(&old->res, stock->charge);
1309 if (do_swap_account)
1310 res_counter_uncharge(&old->memsw, stock->charge);
1312 stock->cached = NULL;
1317 * This must be called under preempt disabled or must be called by
1318 * a thread which is pinned to local cpu.
1320 static void drain_local_stock(struct work_struct *dummy)
1322 struct memcg_stock_pcp *stock = &__get_cpu_var(memcg_stock);
1327 * Cache charges(val) which is from res_counter, to local per_cpu area.
1328 * This will be consumed by consumt_stock() function, later.
1330 static void refill_stock(struct mem_cgroup *mem, int val)
1332 struct memcg_stock_pcp *stock = &get_cpu_var(memcg_stock);
1334 if (stock->cached != mem) { /* reset if necessary */
1336 stock->cached = mem;
1338 stock->charge += val;
1339 put_cpu_var(memcg_stock);
1343 * Tries to drain stocked charges in other cpus. This function is asynchronous
1344 * and just put a work per cpu for draining localy on each cpu. Caller can
1345 * expects some charges will be back to res_counter later but cannot wait for
1348 static void drain_all_stock_async(void)
1351 /* This function is for scheduling "drain" in asynchronous way.
1352 * The result of "drain" is not directly handled by callers. Then,
1353 * if someone is calling drain, we don't have to call drain more.
1354 * Anyway, WORK_STRUCT_PENDING check in queue_work_on() will catch if
1355 * there is a race. We just do loose check here.
1357 if (atomic_read(&memcg_drain_count))
1359 /* Notify other cpus that system-wide "drain" is running */
1360 atomic_inc(&memcg_drain_count);
1362 for_each_online_cpu(cpu) {
1363 struct memcg_stock_pcp *stock = &per_cpu(memcg_stock, cpu);
1364 schedule_work_on(cpu, &stock->work);
1367 atomic_dec(&memcg_drain_count);
1368 /* We don't wait for flush_work */
1371 /* This is a synchronous drain interface. */
1372 static void drain_all_stock_sync(void)
1374 /* called when force_empty is called */
1375 atomic_inc(&memcg_drain_count);
1376 schedule_on_each_cpu(drain_local_stock);
1377 atomic_dec(&memcg_drain_count);
1380 static int __cpuinit memcg_stock_cpu_callback(struct notifier_block *nb,
1381 unsigned long action,
1384 int cpu = (unsigned long)hcpu;
1385 struct memcg_stock_pcp *stock;
1387 if (action != CPU_DEAD)
1389 stock = &per_cpu(memcg_stock, cpu);
1395 * Unlike exported interface, "oom" parameter is added. if oom==true,
1396 * oom-killer can be invoked.
1398 static int __mem_cgroup_try_charge(struct mm_struct *mm,
1399 gfp_t gfp_mask, struct mem_cgroup **memcg,
1400 bool oom, struct page *page)
1402 struct mem_cgroup *mem, *mem_over_limit;
1403 int nr_retries = MEM_CGROUP_RECLAIM_RETRIES;
1404 struct res_counter *fail_res;
1405 int csize = CHARGE_SIZE;
1407 if (unlikely(test_thread_flag(TIF_MEMDIE))) {
1408 /* Don't account this! */
1414 * We always charge the cgroup the mm_struct belongs to.
1415 * The mm_struct's mem_cgroup changes on task migration if the
1416 * thread group leader migrates. It's possible that mm is not
1417 * set, if so charge the init_mm (happens for pagecache usage).
1421 mem = try_get_mem_cgroup_from_mm(mm);
1429 VM_BUG_ON(css_is_removed(&mem->css));
1430 if (mem_cgroup_is_root(mem))
1435 unsigned long flags = 0;
1437 if (consume_stock(mem))
1440 ret = res_counter_charge(&mem->res, csize, &fail_res);
1442 if (!do_swap_account)
1444 ret = res_counter_charge(&mem->memsw, csize, &fail_res);
1447 /* mem+swap counter fails */
1448 res_counter_uncharge(&mem->res, csize);
1449 flags |= MEM_CGROUP_RECLAIM_NOSWAP;
1450 mem_over_limit = mem_cgroup_from_res_counter(fail_res,
1453 /* mem counter fails */
1454 mem_over_limit = mem_cgroup_from_res_counter(fail_res,
1457 /* reduce request size and retry */
1458 if (csize > PAGE_SIZE) {
1462 if (!(gfp_mask & __GFP_WAIT))
1465 ret = mem_cgroup_hierarchical_reclaim(mem_over_limit, NULL,
1471 * try_to_free_mem_cgroup_pages() might not give us a full
1472 * picture of reclaim. Some pages are reclaimed and might be
1473 * moved to swap cache or just unmapped from the cgroup.
1474 * Check the limit again to see if the reclaim reduced the
1475 * current usage of the cgroup before giving up
1478 if (mem_cgroup_check_under_limit(mem_over_limit))
1481 if (!nr_retries--) {
1483 mem_cgroup_out_of_memory(mem_over_limit, gfp_mask);
1484 record_last_oom(mem_over_limit);
1489 if (csize > PAGE_SIZE)
1490 refill_stock(mem, csize - PAGE_SIZE);
1493 * Insert ancestor (and ancestor's ancestors), to softlimit RB-tree.
1494 * if they exceeds softlimit.
1496 if (mem_cgroup_soft_limit_check(mem))
1497 mem_cgroup_update_tree(mem, page);
1506 * Somemtimes we have to undo a charge we got by try_charge().
1507 * This function is for that and do uncharge, put css's refcnt.
1508 * gotten by try_charge().
1510 static void mem_cgroup_cancel_charge(struct mem_cgroup *mem)
1512 if (!mem_cgroup_is_root(mem)) {
1513 res_counter_uncharge(&mem->res, PAGE_SIZE);
1514 if (do_swap_account)
1515 res_counter_uncharge(&mem->memsw, PAGE_SIZE);
1521 * A helper function to get mem_cgroup from ID. must be called under
1522 * rcu_read_lock(). The caller must check css_is_removed() or some if
1523 * it's concern. (dropping refcnt from swap can be called against removed
1526 static struct mem_cgroup *mem_cgroup_lookup(unsigned short id)
1528 struct cgroup_subsys_state *css;
1530 /* ID 0 is unused ID */
1533 css = css_lookup(&mem_cgroup_subsys, id);
1536 return container_of(css, struct mem_cgroup, css);
1539 static struct mem_cgroup *try_get_mem_cgroup_from_swapcache(struct page *page)
1541 struct mem_cgroup *mem;
1542 struct page_cgroup *pc;
1546 VM_BUG_ON(!PageLocked(page));
1548 if (!PageSwapCache(page))
1551 pc = lookup_page_cgroup(page);
1552 lock_page_cgroup(pc);
1553 if (PageCgroupUsed(pc)) {
1554 mem = pc->mem_cgroup;
1555 if (mem && !css_tryget(&mem->css))
1558 ent.val = page_private(page);
1559 id = lookup_swap_cgroup(ent);
1561 mem = mem_cgroup_lookup(id);
1562 if (mem && !css_tryget(&mem->css))
1566 unlock_page_cgroup(pc);
1571 * commit a charge got by __mem_cgroup_try_charge() and makes page_cgroup to be
1572 * USED state. If already USED, uncharge and return.
1575 static void __mem_cgroup_commit_charge(struct mem_cgroup *mem,
1576 struct page_cgroup *pc,
1577 enum charge_type ctype)
1579 /* try_charge() can return NULL to *memcg, taking care of it. */
1583 lock_page_cgroup(pc);
1584 if (unlikely(PageCgroupUsed(pc))) {
1585 unlock_page_cgroup(pc);
1586 mem_cgroup_cancel_charge(mem);
1590 pc->mem_cgroup = mem;
1592 * We access a page_cgroup asynchronously without lock_page_cgroup().
1593 * Especially when a page_cgroup is taken from a page, pc->mem_cgroup
1594 * is accessed after testing USED bit. To make pc->mem_cgroup visible
1595 * before USED bit, we need memory barrier here.
1596 * See mem_cgroup_add_lru_list(), etc.
1600 case MEM_CGROUP_CHARGE_TYPE_CACHE:
1601 case MEM_CGROUP_CHARGE_TYPE_SHMEM:
1602 SetPageCgroupCache(pc);
1603 SetPageCgroupUsed(pc);
1605 case MEM_CGROUP_CHARGE_TYPE_MAPPED:
1606 ClearPageCgroupCache(pc);
1607 SetPageCgroupUsed(pc);
1613 mem_cgroup_charge_statistics(mem, pc, true);
1615 unlock_page_cgroup(pc);
1619 * __mem_cgroup_move_account - move account of the page
1620 * @pc: page_cgroup of the page.
1621 * @from: mem_cgroup which the page is moved from.
1622 * @to: mem_cgroup which the page is moved to. @from != @to.
1624 * The caller must confirm following.
1625 * - page is not on LRU (isolate_page() is useful.)
1626 * - the pc is locked, used, and ->mem_cgroup points to @from.
1628 * This function does "uncharge" from old cgroup but doesn't do "charge" to
1629 * new cgroup. It should be done by a caller.
1632 static void __mem_cgroup_move_account(struct page_cgroup *pc,
1633 struct mem_cgroup *from, struct mem_cgroup *to)
1637 struct mem_cgroup_stat *stat;
1638 struct mem_cgroup_stat_cpu *cpustat;
1640 VM_BUG_ON(from == to);
1641 VM_BUG_ON(PageLRU(pc->page));
1642 VM_BUG_ON(!PageCgroupLocked(pc));
1643 VM_BUG_ON(!PageCgroupUsed(pc));
1644 VM_BUG_ON(pc->mem_cgroup != from);
1646 if (!mem_cgroup_is_root(from))
1647 res_counter_uncharge(&from->res, PAGE_SIZE);
1648 mem_cgroup_charge_statistics(from, pc, false);
1651 if (page_mapped(page) && !PageAnon(page)) {
1652 cpu = smp_processor_id();
1653 /* Update mapped_file data for mem_cgroup "from" */
1655 cpustat = &stat->cpustat[cpu];
1656 __mem_cgroup_stat_add_safe(cpustat, MEM_CGROUP_STAT_FILE_MAPPED,
1659 /* Update mapped_file data for mem_cgroup "to" */
1661 cpustat = &stat->cpustat[cpu];
1662 __mem_cgroup_stat_add_safe(cpustat, MEM_CGROUP_STAT_FILE_MAPPED,
1666 if (do_swap_account && !mem_cgroup_is_root(from))
1667 res_counter_uncharge(&from->memsw, PAGE_SIZE);
1668 css_put(&from->css);
1671 pc->mem_cgroup = to;
1672 mem_cgroup_charge_statistics(to, pc, true);
1674 * We charges against "to" which may not have any tasks. Then, "to"
1675 * can be under rmdir(). But in current implementation, caller of
1676 * this function is just force_empty() and it's garanteed that
1677 * "to" is never removed. So, we don't check rmdir status here.
1682 * check whether the @pc is valid for moving account and call
1683 * __mem_cgroup_move_account()
1685 static int mem_cgroup_move_account(struct page_cgroup *pc,
1686 struct mem_cgroup *from, struct mem_cgroup *to)
1689 lock_page_cgroup(pc);
1690 if (PageCgroupUsed(pc) && pc->mem_cgroup == from) {
1691 __mem_cgroup_move_account(pc, from, to);
1694 unlock_page_cgroup(pc);
1699 * move charges to its parent.
1702 static int mem_cgroup_move_parent(struct page_cgroup *pc,
1703 struct mem_cgroup *child,
1706 struct page *page = pc->page;
1707 struct cgroup *cg = child->css.cgroup;
1708 struct cgroup *pcg = cg->parent;
1709 struct mem_cgroup *parent;
1717 if (!get_page_unless_zero(page))
1719 if (isolate_lru_page(page))
1722 parent = mem_cgroup_from_cont(pcg);
1723 ret = __mem_cgroup_try_charge(NULL, gfp_mask, &parent, false, page);
1727 ret = mem_cgroup_move_account(pc, child, parent);
1729 css_put(&parent->css); /* drop extra refcnt by try_charge() */
1731 mem_cgroup_cancel_charge(parent); /* does css_put */
1733 putback_lru_page(page);
1741 * Charge the memory controller for page usage.
1743 * 0 if the charge was successful
1744 * < 0 if the cgroup is over its limit
1746 static int mem_cgroup_charge_common(struct page *page, struct mm_struct *mm,
1747 gfp_t gfp_mask, enum charge_type ctype,
1748 struct mem_cgroup *memcg)
1750 struct mem_cgroup *mem;
1751 struct page_cgroup *pc;
1754 pc = lookup_page_cgroup(page);
1755 /* can happen at boot */
1761 ret = __mem_cgroup_try_charge(mm, gfp_mask, &mem, true, page);
1765 __mem_cgroup_commit_charge(mem, pc, ctype);
1769 int mem_cgroup_newpage_charge(struct page *page,
1770 struct mm_struct *mm, gfp_t gfp_mask)
1772 if (mem_cgroup_disabled())
1774 if (PageCompound(page))
1777 * If already mapped, we don't have to account.
1778 * If page cache, page->mapping has address_space.
1779 * But page->mapping may have out-of-use anon_vma pointer,
1780 * detecit it by PageAnon() check. newly-mapped-anon's page->mapping
1783 if (page_mapped(page) || (page->mapping && !PageAnon(page)))
1787 return mem_cgroup_charge_common(page, mm, gfp_mask,
1788 MEM_CGROUP_CHARGE_TYPE_MAPPED, NULL);
1792 __mem_cgroup_commit_charge_swapin(struct page *page, struct mem_cgroup *ptr,
1793 enum charge_type ctype);
1795 int mem_cgroup_cache_charge(struct page *page, struct mm_struct *mm,
1798 struct mem_cgroup *mem = NULL;
1801 if (mem_cgroup_disabled())
1803 if (PageCompound(page))
1806 * Corner case handling. This is called from add_to_page_cache()
1807 * in usual. But some FS (shmem) precharges this page before calling it
1808 * and call add_to_page_cache() with GFP_NOWAIT.
1810 * For GFP_NOWAIT case, the page may be pre-charged before calling
1811 * add_to_page_cache(). (See shmem.c) check it here and avoid to call
1812 * charge twice. (It works but has to pay a bit larger cost.)
1813 * And when the page is SwapCache, it should take swap information
1814 * into account. This is under lock_page() now.
1816 if (!(gfp_mask & __GFP_WAIT)) {
1817 struct page_cgroup *pc;
1820 pc = lookup_page_cgroup(page);
1823 lock_page_cgroup(pc);
1824 if (PageCgroupUsed(pc)) {
1825 unlock_page_cgroup(pc);
1828 unlock_page_cgroup(pc);
1831 if (unlikely(!mm && !mem))
1834 if (page_is_file_cache(page))
1835 return mem_cgroup_charge_common(page, mm, gfp_mask,
1836 MEM_CGROUP_CHARGE_TYPE_CACHE, NULL);
1839 if (PageSwapCache(page)) {
1840 ret = mem_cgroup_try_charge_swapin(mm, page, gfp_mask, &mem);
1842 __mem_cgroup_commit_charge_swapin(page, mem,
1843 MEM_CGROUP_CHARGE_TYPE_SHMEM);
1845 ret = mem_cgroup_charge_common(page, mm, gfp_mask,
1846 MEM_CGROUP_CHARGE_TYPE_SHMEM, mem);
1852 * While swap-in, try_charge -> commit or cancel, the page is locked.
1853 * And when try_charge() successfully returns, one refcnt to memcg without
1854 * struct page_cgroup is acquired. This refcnt will be consumed by
1855 * "commit()" or removed by "cancel()"
1857 int mem_cgroup_try_charge_swapin(struct mm_struct *mm,
1859 gfp_t mask, struct mem_cgroup **ptr)
1861 struct mem_cgroup *mem;
1864 if (mem_cgroup_disabled())
1867 if (!do_swap_account)
1870 * A racing thread's fault, or swapoff, may have already updated
1871 * the pte, and even removed page from swap cache: in those cases
1872 * do_swap_page()'s pte_same() test will fail; but there's also a
1873 * KSM case which does need to charge the page.
1875 if (!PageSwapCache(page))
1877 mem = try_get_mem_cgroup_from_swapcache(page);
1881 ret = __mem_cgroup_try_charge(NULL, mask, ptr, true, page);
1882 /* drop extra refcnt from tryget */
1888 return __mem_cgroup_try_charge(mm, mask, ptr, true, page);
1892 __mem_cgroup_commit_charge_swapin(struct page *page, struct mem_cgroup *ptr,
1893 enum charge_type ctype)
1895 struct page_cgroup *pc;
1897 if (mem_cgroup_disabled())
1901 cgroup_exclude_rmdir(&ptr->css);
1902 pc = lookup_page_cgroup(page);
1903 mem_cgroup_lru_del_before_commit_swapcache(page);
1904 __mem_cgroup_commit_charge(ptr, pc, ctype);
1905 mem_cgroup_lru_add_after_commit_swapcache(page);
1907 * Now swap is on-memory. This means this page may be
1908 * counted both as mem and swap....double count.
1909 * Fix it by uncharging from memsw. Basically, this SwapCache is stable
1910 * under lock_page(). But in do_swap_page()::memory.c, reuse_swap_page()
1911 * may call delete_from_swap_cache() before reach here.
1913 if (do_swap_account && PageSwapCache(page)) {
1914 swp_entry_t ent = {.val = page_private(page)};
1916 struct mem_cgroup *memcg;
1918 id = swap_cgroup_record(ent, 0);
1920 memcg = mem_cgroup_lookup(id);
1923 * This recorded memcg can be obsolete one. So, avoid
1924 * calling css_tryget
1926 if (!mem_cgroup_is_root(memcg))
1927 res_counter_uncharge(&memcg->memsw, PAGE_SIZE);
1928 mem_cgroup_swap_statistics(memcg, false);
1929 mem_cgroup_put(memcg);
1934 * At swapin, we may charge account against cgroup which has no tasks.
1935 * So, rmdir()->pre_destroy() can be called while we do this charge.
1936 * In that case, we need to call pre_destroy() again. check it here.
1938 cgroup_release_and_wakeup_rmdir(&ptr->css);
1941 void mem_cgroup_commit_charge_swapin(struct page *page, struct mem_cgroup *ptr)
1943 __mem_cgroup_commit_charge_swapin(page, ptr,
1944 MEM_CGROUP_CHARGE_TYPE_MAPPED);
1947 void mem_cgroup_cancel_charge_swapin(struct mem_cgroup *mem)
1949 if (mem_cgroup_disabled())
1953 mem_cgroup_cancel_charge(mem);
1957 __do_uncharge(struct mem_cgroup *mem, const enum charge_type ctype)
1959 struct memcg_batch_info *batch = NULL;
1960 bool uncharge_memsw = true;
1961 /* If swapout, usage of swap doesn't decrease */
1962 if (!do_swap_account || ctype == MEM_CGROUP_CHARGE_TYPE_SWAPOUT)
1963 uncharge_memsw = false;
1965 * do_batch > 0 when unmapping pages or inode invalidate/truncate.
1966 * In those cases, all pages freed continously can be expected to be in
1967 * the same cgroup and we have chance to coalesce uncharges.
1968 * But we do uncharge one by one if this is killed by OOM(TIF_MEMDIE)
1969 * because we want to do uncharge as soon as possible.
1971 if (!current->memcg_batch.do_batch || test_thread_flag(TIF_MEMDIE))
1972 goto direct_uncharge;
1974 batch = ¤t->memcg_batch;
1976 * In usual, we do css_get() when we remember memcg pointer.
1977 * But in this case, we keep res->usage until end of a series of
1978 * uncharges. Then, it's ok to ignore memcg's refcnt.
1983 * In typical case, batch->memcg == mem. This means we can
1984 * merge a series of uncharges to an uncharge of res_counter.
1985 * If not, we uncharge res_counter ony by one.
1987 if (batch->memcg != mem)
1988 goto direct_uncharge;
1989 /* remember freed charge and uncharge it later */
1990 batch->bytes += PAGE_SIZE;
1992 batch->memsw_bytes += PAGE_SIZE;
1995 res_counter_uncharge(&mem->res, PAGE_SIZE);
1997 res_counter_uncharge(&mem->memsw, PAGE_SIZE);
2002 * uncharge if !page_mapped(page)
2004 static struct mem_cgroup *
2005 __mem_cgroup_uncharge_common(struct page *page, enum charge_type ctype)
2007 struct page_cgroup *pc;
2008 struct mem_cgroup *mem = NULL;
2009 struct mem_cgroup_per_zone *mz;
2011 if (mem_cgroup_disabled())
2014 if (PageSwapCache(page))
2018 * Check if our page_cgroup is valid
2020 pc = lookup_page_cgroup(page);
2021 if (unlikely(!pc || !PageCgroupUsed(pc)))
2024 lock_page_cgroup(pc);
2026 mem = pc->mem_cgroup;
2028 if (!PageCgroupUsed(pc))
2032 case MEM_CGROUP_CHARGE_TYPE_MAPPED:
2033 case MEM_CGROUP_CHARGE_TYPE_DROP:
2034 if (page_mapped(page))
2037 case MEM_CGROUP_CHARGE_TYPE_SWAPOUT:
2038 if (!PageAnon(page)) { /* Shared memory */
2039 if (page->mapping && !page_is_file_cache(page))
2041 } else if (page_mapped(page)) /* Anon */
2048 if (!mem_cgroup_is_root(mem))
2049 __do_uncharge(mem, ctype);
2050 if (ctype == MEM_CGROUP_CHARGE_TYPE_SWAPOUT)
2051 mem_cgroup_swap_statistics(mem, true);
2052 mem_cgroup_charge_statistics(mem, pc, false);
2054 ClearPageCgroupUsed(pc);
2056 * pc->mem_cgroup is not cleared here. It will be accessed when it's
2057 * freed from LRU. This is safe because uncharged page is expected not
2058 * to be reused (freed soon). Exception is SwapCache, it's handled by
2059 * special functions.
2062 mz = page_cgroup_zoneinfo(pc);
2063 unlock_page_cgroup(pc);
2065 if (mem_cgroup_soft_limit_check(mem))
2066 mem_cgroup_update_tree(mem, page);
2067 /* at swapout, this memcg will be accessed to record to swap */
2068 if (ctype != MEM_CGROUP_CHARGE_TYPE_SWAPOUT)
2074 unlock_page_cgroup(pc);
2078 void mem_cgroup_uncharge_page(struct page *page)
2081 if (page_mapped(page))
2083 if (page->mapping && !PageAnon(page))
2085 __mem_cgroup_uncharge_common(page, MEM_CGROUP_CHARGE_TYPE_MAPPED);
2088 void mem_cgroup_uncharge_cache_page(struct page *page)
2090 VM_BUG_ON(page_mapped(page));
2091 VM_BUG_ON(page->mapping);
2092 __mem_cgroup_uncharge_common(page, MEM_CGROUP_CHARGE_TYPE_CACHE);
2096 * Batch_start/batch_end is called in unmap_page_range/invlidate/trucate.
2097 * In that cases, pages are freed continuously and we can expect pages
2098 * are in the same memcg. All these calls itself limits the number of
2099 * pages freed at once, then uncharge_start/end() is called properly.
2100 * This may be called prural(2) times in a context,
2103 void mem_cgroup_uncharge_start(void)
2105 current->memcg_batch.do_batch++;
2106 /* We can do nest. */
2107 if (current->memcg_batch.do_batch == 1) {
2108 current->memcg_batch.memcg = NULL;
2109 current->memcg_batch.bytes = 0;
2110 current->memcg_batch.memsw_bytes = 0;
2114 void mem_cgroup_uncharge_end(void)
2116 struct memcg_batch_info *batch = ¤t->memcg_batch;
2118 if (!batch->do_batch)
2122 if (batch->do_batch) /* If stacked, do nothing. */
2128 * This "batch->memcg" is valid without any css_get/put etc...
2129 * bacause we hide charges behind us.
2132 res_counter_uncharge(&batch->memcg->res, batch->bytes);
2133 if (batch->memsw_bytes)
2134 res_counter_uncharge(&batch->memcg->memsw, batch->memsw_bytes);
2135 /* forget this pointer (for sanity check) */
2136 batch->memcg = NULL;
2141 * called after __delete_from_swap_cache() and drop "page" account.
2142 * memcg information is recorded to swap_cgroup of "ent"
2145 mem_cgroup_uncharge_swapcache(struct page *page, swp_entry_t ent, bool swapout)
2147 struct mem_cgroup *memcg;
2148 int ctype = MEM_CGROUP_CHARGE_TYPE_SWAPOUT;
2150 if (!swapout) /* this was a swap cache but the swap is unused ! */
2151 ctype = MEM_CGROUP_CHARGE_TYPE_DROP;
2153 memcg = __mem_cgroup_uncharge_common(page, ctype);
2155 /* record memcg information */
2156 if (do_swap_account && swapout && memcg) {
2157 swap_cgroup_record(ent, css_id(&memcg->css));
2158 mem_cgroup_get(memcg);
2160 if (swapout && memcg)
2161 css_put(&memcg->css);
2165 #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP
2167 * called from swap_entry_free(). remove record in swap_cgroup and
2168 * uncharge "memsw" account.
2170 void mem_cgroup_uncharge_swap(swp_entry_t ent)
2172 struct mem_cgroup *memcg;
2175 if (!do_swap_account)
2178 id = swap_cgroup_record(ent, 0);
2180 memcg = mem_cgroup_lookup(id);
2183 * We uncharge this because swap is freed.
2184 * This memcg can be obsolete one. We avoid calling css_tryget
2186 if (!mem_cgroup_is_root(memcg))
2187 res_counter_uncharge(&memcg->memsw, PAGE_SIZE);
2188 mem_cgroup_swap_statistics(memcg, false);
2189 mem_cgroup_put(memcg);
2196 * Before starting migration, account PAGE_SIZE to mem_cgroup that the old
2199 int mem_cgroup_prepare_migration(struct page *page, struct mem_cgroup **ptr)
2201 struct page_cgroup *pc;
2202 struct mem_cgroup *mem = NULL;
2205 if (mem_cgroup_disabled())
2208 pc = lookup_page_cgroup(page);
2209 lock_page_cgroup(pc);
2210 if (PageCgroupUsed(pc)) {
2211 mem = pc->mem_cgroup;
2214 unlock_page_cgroup(pc);
2217 ret = __mem_cgroup_try_charge(NULL, GFP_KERNEL, &mem, false,
2225 /* remove redundant charge if migration failed*/
2226 void mem_cgroup_end_migration(struct mem_cgroup *mem,
2227 struct page *oldpage, struct page *newpage)
2229 struct page *target, *unused;
2230 struct page_cgroup *pc;
2231 enum charge_type ctype;
2235 cgroup_exclude_rmdir(&mem->css);
2236 /* at migration success, oldpage->mapping is NULL. */
2237 if (oldpage->mapping) {
2245 if (PageAnon(target))
2246 ctype = MEM_CGROUP_CHARGE_TYPE_MAPPED;
2247 else if (page_is_file_cache(target))
2248 ctype = MEM_CGROUP_CHARGE_TYPE_CACHE;
2250 ctype = MEM_CGROUP_CHARGE_TYPE_SHMEM;
2252 /* unused page is not on radix-tree now. */
2254 __mem_cgroup_uncharge_common(unused, ctype);
2256 pc = lookup_page_cgroup(target);
2258 * __mem_cgroup_commit_charge() check PCG_USED bit of page_cgroup.
2259 * So, double-counting is effectively avoided.
2261 __mem_cgroup_commit_charge(mem, pc, ctype);
2264 * Both of oldpage and newpage are still under lock_page().
2265 * Then, we don't have to care about race in radix-tree.
2266 * But we have to be careful that this page is unmapped or not.
2268 * There is a case for !page_mapped(). At the start of
2269 * migration, oldpage was mapped. But now, it's zapped.
2270 * But we know *target* page is not freed/reused under us.
2271 * mem_cgroup_uncharge_page() does all necessary checks.
2273 if (ctype == MEM_CGROUP_CHARGE_TYPE_MAPPED)
2274 mem_cgroup_uncharge_page(target);
2276 * At migration, we may charge account against cgroup which has no tasks
2277 * So, rmdir()->pre_destroy() can be called while we do this charge.
2278 * In that case, we need to call pre_destroy() again. check it here.
2280 cgroup_release_and_wakeup_rmdir(&mem->css);
2284 * A call to try to shrink memory usage on charge failure at shmem's swapin.
2285 * Calling hierarchical_reclaim is not enough because we should update
2286 * last_oom_jiffies to prevent pagefault_out_of_memory from invoking global OOM.
2287 * Moreover considering hierarchy, we should reclaim from the mem_over_limit,
2288 * not from the memcg which this page would be charged to.
2289 * try_charge_swapin does all of these works properly.
2291 int mem_cgroup_shmem_charge_fallback(struct page *page,
2292 struct mm_struct *mm,
2295 struct mem_cgroup *mem = NULL;
2298 if (mem_cgroup_disabled())
2301 ret = mem_cgroup_try_charge_swapin(mm, page, gfp_mask, &mem);
2303 mem_cgroup_cancel_charge_swapin(mem); /* it does !mem check */
2308 static DEFINE_MUTEX(set_limit_mutex);
2310 static int mem_cgroup_resize_limit(struct mem_cgroup *memcg,
2311 unsigned long long val)
2316 int children = mem_cgroup_count_children(memcg);
2317 u64 curusage, oldusage;
2320 * For keeping hierarchical_reclaim simple, how long we should retry
2321 * is depends on callers. We set our retry-count to be function
2322 * of # of children which we should visit in this loop.
2324 retry_count = MEM_CGROUP_RECLAIM_RETRIES * children;
2326 oldusage = res_counter_read_u64(&memcg->res, RES_USAGE);
2328 while (retry_count) {
2329 if (signal_pending(current)) {
2334 * Rather than hide all in some function, I do this in
2335 * open coded manner. You see what this really does.
2336 * We have to guarantee mem->res.limit < mem->memsw.limit.
2338 mutex_lock(&set_limit_mutex);
2339 memswlimit = res_counter_read_u64(&memcg->memsw, RES_LIMIT);
2340 if (memswlimit < val) {
2342 mutex_unlock(&set_limit_mutex);
2345 ret = res_counter_set_limit(&memcg->res, val);
2347 if (memswlimit == val)
2348 memcg->memsw_is_minimum = true;
2350 memcg->memsw_is_minimum = false;
2352 mutex_unlock(&set_limit_mutex);
2357 mem_cgroup_hierarchical_reclaim(memcg, NULL, GFP_KERNEL,
2358 MEM_CGROUP_RECLAIM_SHRINK);
2359 curusage = res_counter_read_u64(&memcg->res, RES_USAGE);
2360 /* Usage is reduced ? */
2361 if (curusage >= oldusage)
2364 oldusage = curusage;
2370 static int mem_cgroup_resize_memsw_limit(struct mem_cgroup *memcg,
2371 unsigned long long val)
2374 u64 memlimit, oldusage, curusage;
2375 int children = mem_cgroup_count_children(memcg);
2378 /* see mem_cgroup_resize_res_limit */
2379 retry_count = children * MEM_CGROUP_RECLAIM_RETRIES;
2380 oldusage = res_counter_read_u64(&memcg->memsw, RES_USAGE);
2381 while (retry_count) {
2382 if (signal_pending(current)) {
2387 * Rather than hide all in some function, I do this in
2388 * open coded manner. You see what this really does.
2389 * We have to guarantee mem->res.limit < mem->memsw.limit.
2391 mutex_lock(&set_limit_mutex);
2392 memlimit = res_counter_read_u64(&memcg->res, RES_LIMIT);
2393 if (memlimit > val) {
2395 mutex_unlock(&set_limit_mutex);
2398 ret = res_counter_set_limit(&memcg->memsw, val);
2400 if (memlimit == val)
2401 memcg->memsw_is_minimum = true;
2403 memcg->memsw_is_minimum = false;
2405 mutex_unlock(&set_limit_mutex);
2410 mem_cgroup_hierarchical_reclaim(memcg, NULL, GFP_KERNEL,
2411 MEM_CGROUP_RECLAIM_NOSWAP |
2412 MEM_CGROUP_RECLAIM_SHRINK);
2413 curusage = res_counter_read_u64(&memcg->memsw, RES_USAGE);
2414 /* Usage is reduced ? */
2415 if (curusage >= oldusage)
2418 oldusage = curusage;
2423 unsigned long mem_cgroup_soft_limit_reclaim(struct zone *zone, int order,
2424 gfp_t gfp_mask, int nid,
2427 unsigned long nr_reclaimed = 0;
2428 struct mem_cgroup_per_zone *mz, *next_mz = NULL;
2429 unsigned long reclaimed;
2431 struct mem_cgroup_tree_per_zone *mctz;
2432 unsigned long long excess;
2437 mctz = soft_limit_tree_node_zone(nid, zid);
2439 * This loop can run a while, specially if mem_cgroup's continuously
2440 * keep exceeding their soft limit and putting the system under
2447 mz = mem_cgroup_largest_soft_limit_node(mctz);
2451 reclaimed = mem_cgroup_hierarchical_reclaim(mz->mem, zone,
2453 MEM_CGROUP_RECLAIM_SOFT);
2454 nr_reclaimed += reclaimed;
2455 spin_lock(&mctz->lock);
2458 * If we failed to reclaim anything from this memory cgroup
2459 * it is time to move on to the next cgroup
2465 * Loop until we find yet another one.
2467 * By the time we get the soft_limit lock
2468 * again, someone might have aded the
2469 * group back on the RB tree. Iterate to
2470 * make sure we get a different mem.
2471 * mem_cgroup_largest_soft_limit_node returns
2472 * NULL if no other cgroup is present on
2476 __mem_cgroup_largest_soft_limit_node(mctz);
2477 if (next_mz == mz) {
2478 css_put(&next_mz->mem->css);
2480 } else /* next_mz == NULL or other memcg */
2484 __mem_cgroup_remove_exceeded(mz->mem, mz, mctz);
2485 excess = res_counter_soft_limit_excess(&mz->mem->res);
2487 * One school of thought says that we should not add
2488 * back the node to the tree if reclaim returns 0.
2489 * But our reclaim could return 0, simply because due
2490 * to priority we are exposing a smaller subset of
2491 * memory to reclaim from. Consider this as a longer
2494 /* If excess == 0, no tree ops */
2495 __mem_cgroup_insert_exceeded(mz->mem, mz, mctz, excess);
2496 spin_unlock(&mctz->lock);
2497 css_put(&mz->mem->css);
2500 * Could not reclaim anything and there are no more
2501 * mem cgroups to try or we seem to be looping without
2502 * reclaiming anything.
2504 if (!nr_reclaimed &&
2506 loop > MEM_CGROUP_MAX_SOFT_LIMIT_RECLAIM_LOOPS))
2508 } while (!nr_reclaimed);
2510 css_put(&next_mz->mem->css);
2511 return nr_reclaimed;
2515 * This routine traverse page_cgroup in given list and drop them all.
2516 * *And* this routine doesn't reclaim page itself, just removes page_cgroup.
2518 static int mem_cgroup_force_empty_list(struct mem_cgroup *mem,
2519 int node, int zid, enum lru_list lru)
2522 struct mem_cgroup_per_zone *mz;
2523 struct page_cgroup *pc, *busy;
2524 unsigned long flags, loop;
2525 struct list_head *list;
2528 zone = &NODE_DATA(node)->node_zones[zid];
2529 mz = mem_cgroup_zoneinfo(mem, node, zid);
2530 list = &mz->lists[lru];
2532 loop = MEM_CGROUP_ZSTAT(mz, lru);
2533 /* give some margin against EBUSY etc...*/
2538 spin_lock_irqsave(&zone->lru_lock, flags);
2539 if (list_empty(list)) {
2540 spin_unlock_irqrestore(&zone->lru_lock, flags);
2543 pc = list_entry(list->prev, struct page_cgroup, lru);
2545 list_move(&pc->lru, list);
2547 spin_unlock_irqrestore(&zone->lru_lock, flags);
2550 spin_unlock_irqrestore(&zone->lru_lock, flags);
2552 ret = mem_cgroup_move_parent(pc, mem, GFP_KERNEL);
2556 if (ret == -EBUSY || ret == -EINVAL) {
2557 /* found lock contention or "pc" is obsolete. */
2564 if (!ret && !list_empty(list))
2570 * make mem_cgroup's charge to be 0 if there is no task.
2571 * This enables deleting this mem_cgroup.
2573 static int mem_cgroup_force_empty(struct mem_cgroup *mem, bool free_all)
2576 int node, zid, shrink;
2577 int nr_retries = MEM_CGROUP_RECLAIM_RETRIES;
2578 struct cgroup *cgrp = mem->css.cgroup;
2583 /* should free all ? */
2587 while (mem->res.usage > 0) {
2589 if (cgroup_task_count(cgrp) || !list_empty(&cgrp->children))
2592 if (signal_pending(current))
2594 /* This is for making all *used* pages to be on LRU. */
2595 lru_add_drain_all();
2596 drain_all_stock_sync();
2598 for_each_node_state(node, N_HIGH_MEMORY) {
2599 for (zid = 0; !ret && zid < MAX_NR_ZONES; zid++) {
2602 ret = mem_cgroup_force_empty_list(mem,
2611 /* it seems parent cgroup doesn't have enough mem */
2622 /* returns EBUSY if there is a task or if we come here twice. */
2623 if (cgroup_task_count(cgrp) || !list_empty(&cgrp->children) || shrink) {
2627 /* we call try-to-free pages for make this cgroup empty */
2628 lru_add_drain_all();
2629 /* try to free all pages in this cgroup */
2631 while (nr_retries && mem->res.usage > 0) {
2634 if (signal_pending(current)) {
2638 progress = try_to_free_mem_cgroup_pages(mem, GFP_KERNEL,
2639 false, get_swappiness(mem));
2642 /* maybe some writeback is necessary */
2643 congestion_wait(BLK_RW_ASYNC, HZ/10);
2648 /* try move_account...there may be some *locked* pages. */
2655 int mem_cgroup_force_empty_write(struct cgroup *cont, unsigned int event)
2657 return mem_cgroup_force_empty(mem_cgroup_from_cont(cont), true);
2661 static u64 mem_cgroup_hierarchy_read(struct cgroup *cont, struct cftype *cft)
2663 return mem_cgroup_from_cont(cont)->use_hierarchy;
2666 static int mem_cgroup_hierarchy_write(struct cgroup *cont, struct cftype *cft,
2670 struct mem_cgroup *mem = mem_cgroup_from_cont(cont);
2671 struct cgroup *parent = cont->parent;
2672 struct mem_cgroup *parent_mem = NULL;
2675 parent_mem = mem_cgroup_from_cont(parent);
2679 * If parent's use_hierarchy is set, we can't make any modifications
2680 * in the child subtrees. If it is unset, then the change can
2681 * occur, provided the current cgroup has no children.
2683 * For the root cgroup, parent_mem is NULL, we allow value to be
2684 * set if there are no children.
2686 if ((!parent_mem || !parent_mem->use_hierarchy) &&
2687 (val == 1 || val == 0)) {
2688 if (list_empty(&cont->children))
2689 mem->use_hierarchy = val;
2699 struct mem_cgroup_idx_data {
2701 enum mem_cgroup_stat_index idx;
2705 mem_cgroup_get_idx_stat(struct mem_cgroup *mem, void *data)
2707 struct mem_cgroup_idx_data *d = data;
2708 d->val += mem_cgroup_read_stat(&mem->stat, d->idx);
2713 mem_cgroup_get_recursive_idx_stat(struct mem_cgroup *mem,
2714 enum mem_cgroup_stat_index idx, s64 *val)
2716 struct mem_cgroup_idx_data d;
2719 mem_cgroup_walk_tree(mem, &d, mem_cgroup_get_idx_stat);
2723 static u64 mem_cgroup_read(struct cgroup *cont, struct cftype *cft)
2725 struct mem_cgroup *mem = mem_cgroup_from_cont(cont);
2729 type = MEMFILE_TYPE(cft->private);
2730 name = MEMFILE_ATTR(cft->private);
2733 if (name == RES_USAGE && mem_cgroup_is_root(mem)) {
2734 mem_cgroup_get_recursive_idx_stat(mem,
2735 MEM_CGROUP_STAT_CACHE, &idx_val);
2737 mem_cgroup_get_recursive_idx_stat(mem,
2738 MEM_CGROUP_STAT_RSS, &idx_val);
2742 val = res_counter_read_u64(&mem->res, name);
2745 if (name == RES_USAGE && mem_cgroup_is_root(mem)) {
2746 mem_cgroup_get_recursive_idx_stat(mem,
2747 MEM_CGROUP_STAT_CACHE, &idx_val);
2749 mem_cgroup_get_recursive_idx_stat(mem,
2750 MEM_CGROUP_STAT_RSS, &idx_val);
2752 mem_cgroup_get_recursive_idx_stat(mem,
2753 MEM_CGROUP_STAT_SWAPOUT, &idx_val);
2757 val = res_counter_read_u64(&mem->memsw, name);
2766 * The user of this function is...
2769 static int mem_cgroup_write(struct cgroup *cont, struct cftype *cft,
2772 struct mem_cgroup *memcg = mem_cgroup_from_cont(cont);
2774 unsigned long long val;
2777 type = MEMFILE_TYPE(cft->private);
2778 name = MEMFILE_ATTR(cft->private);
2781 if (mem_cgroup_is_root(memcg)) { /* Can't set limit on root */
2785 /* This function does all necessary parse...reuse it */
2786 ret = res_counter_memparse_write_strategy(buffer, &val);
2790 ret = mem_cgroup_resize_limit(memcg, val);
2792 ret = mem_cgroup_resize_memsw_limit(memcg, val);
2794 case RES_SOFT_LIMIT:
2795 ret = res_counter_memparse_write_strategy(buffer, &val);
2799 * For memsw, soft limits are hard to implement in terms
2800 * of semantics, for now, we support soft limits for
2801 * control without swap
2804 ret = res_counter_set_soft_limit(&memcg->res, val);
2809 ret = -EINVAL; /* should be BUG() ? */
2815 static void memcg_get_hierarchical_limit(struct mem_cgroup *memcg,
2816 unsigned long long *mem_limit, unsigned long long *memsw_limit)
2818 struct cgroup *cgroup;
2819 unsigned long long min_limit, min_memsw_limit, tmp;
2821 min_limit = res_counter_read_u64(&memcg->res, RES_LIMIT);
2822 min_memsw_limit = res_counter_read_u64(&memcg->memsw, RES_LIMIT);
2823 cgroup = memcg->css.cgroup;
2824 if (!memcg->use_hierarchy)
2827 while (cgroup->parent) {
2828 cgroup = cgroup->parent;
2829 memcg = mem_cgroup_from_cont(cgroup);
2830 if (!memcg->use_hierarchy)
2832 tmp = res_counter_read_u64(&memcg->res, RES_LIMIT);
2833 min_limit = min(min_limit, tmp);
2834 tmp = res_counter_read_u64(&memcg->memsw, RES_LIMIT);
2835 min_memsw_limit = min(min_memsw_limit, tmp);
2838 *mem_limit = min_limit;
2839 *memsw_limit = min_memsw_limit;
2843 static int mem_cgroup_reset(struct cgroup *cont, unsigned int event)
2845 struct mem_cgroup *mem;
2848 mem = mem_cgroup_from_cont(cont);
2849 type = MEMFILE_TYPE(event);
2850 name = MEMFILE_ATTR(event);
2854 res_counter_reset_max(&mem->res);
2856 res_counter_reset_max(&mem->memsw);
2860 res_counter_reset_failcnt(&mem->res);
2862 res_counter_reset_failcnt(&mem->memsw);
2870 /* For read statistics */
2886 struct mcs_total_stat {
2887 s64 stat[NR_MCS_STAT];
2893 } memcg_stat_strings[NR_MCS_STAT] = {
2894 {"cache", "total_cache"},
2895 {"rss", "total_rss"},
2896 {"mapped_file", "total_mapped_file"},
2897 {"pgpgin", "total_pgpgin"},
2898 {"pgpgout", "total_pgpgout"},
2899 {"swap", "total_swap"},
2900 {"inactive_anon", "total_inactive_anon"},
2901 {"active_anon", "total_active_anon"},
2902 {"inactive_file", "total_inactive_file"},
2903 {"active_file", "total_active_file"},
2904 {"unevictable", "total_unevictable"}
2908 static int mem_cgroup_get_local_stat(struct mem_cgroup *mem, void *data)
2910 struct mcs_total_stat *s = data;
2914 val = mem_cgroup_read_stat(&mem->stat, MEM_CGROUP_STAT_CACHE);
2915 s->stat[MCS_CACHE] += val * PAGE_SIZE;
2916 val = mem_cgroup_read_stat(&mem->stat, MEM_CGROUP_STAT_RSS);
2917 s->stat[MCS_RSS] += val * PAGE_SIZE;
2918 val = mem_cgroup_read_stat(&mem->stat, MEM_CGROUP_STAT_FILE_MAPPED);
2919 s->stat[MCS_FILE_MAPPED] += val * PAGE_SIZE;
2920 val = mem_cgroup_read_stat(&mem->stat, MEM_CGROUP_STAT_PGPGIN_COUNT);
2921 s->stat[MCS_PGPGIN] += val;
2922 val = mem_cgroup_read_stat(&mem->stat, MEM_CGROUP_STAT_PGPGOUT_COUNT);
2923 s->stat[MCS_PGPGOUT] += val;
2924 if (do_swap_account) {
2925 val = mem_cgroup_read_stat(&mem->stat, MEM_CGROUP_STAT_SWAPOUT);
2926 s->stat[MCS_SWAP] += val * PAGE_SIZE;
2930 val = mem_cgroup_get_local_zonestat(mem, LRU_INACTIVE_ANON);
2931 s->stat[MCS_INACTIVE_ANON] += val * PAGE_SIZE;
2932 val = mem_cgroup_get_local_zonestat(mem, LRU_ACTIVE_ANON);
2933 s->stat[MCS_ACTIVE_ANON] += val * PAGE_SIZE;
2934 val = mem_cgroup_get_local_zonestat(mem, LRU_INACTIVE_FILE);
2935 s->stat[MCS_INACTIVE_FILE] += val * PAGE_SIZE;
2936 val = mem_cgroup_get_local_zonestat(mem, LRU_ACTIVE_FILE);
2937 s->stat[MCS_ACTIVE_FILE] += val * PAGE_SIZE;
2938 val = mem_cgroup_get_local_zonestat(mem, LRU_UNEVICTABLE);
2939 s->stat[MCS_UNEVICTABLE] += val * PAGE_SIZE;
2944 mem_cgroup_get_total_stat(struct mem_cgroup *mem, struct mcs_total_stat *s)
2946 mem_cgroup_walk_tree(mem, s, mem_cgroup_get_local_stat);
2949 static int mem_control_stat_show(struct cgroup *cont, struct cftype *cft,
2950 struct cgroup_map_cb *cb)
2952 struct mem_cgroup *mem_cont = mem_cgroup_from_cont(cont);
2953 struct mcs_total_stat mystat;
2956 memset(&mystat, 0, sizeof(mystat));
2957 mem_cgroup_get_local_stat(mem_cont, &mystat);
2959 for (i = 0; i < NR_MCS_STAT; i++) {
2960 if (i == MCS_SWAP && !do_swap_account)
2962 cb->fill(cb, memcg_stat_strings[i].local_name, mystat.stat[i]);
2965 /* Hierarchical information */
2967 unsigned long long limit, memsw_limit;
2968 memcg_get_hierarchical_limit(mem_cont, &limit, &memsw_limit);
2969 cb->fill(cb, "hierarchical_memory_limit", limit);
2970 if (do_swap_account)
2971 cb->fill(cb, "hierarchical_memsw_limit", memsw_limit);
2974 memset(&mystat, 0, sizeof(mystat));
2975 mem_cgroup_get_total_stat(mem_cont, &mystat);
2976 for (i = 0; i < NR_MCS_STAT; i++) {
2977 if (i == MCS_SWAP && !do_swap_account)
2979 cb->fill(cb, memcg_stat_strings[i].total_name, mystat.stat[i]);
2982 #ifdef CONFIG_DEBUG_VM
2983 cb->fill(cb, "inactive_ratio", calc_inactive_ratio(mem_cont, NULL));
2987 struct mem_cgroup_per_zone *mz;
2988 unsigned long recent_rotated[2] = {0, 0};
2989 unsigned long recent_scanned[2] = {0, 0};
2991 for_each_online_node(nid)
2992 for (zid = 0; zid < MAX_NR_ZONES; zid++) {
2993 mz = mem_cgroup_zoneinfo(mem_cont, nid, zid);
2995 recent_rotated[0] +=
2996 mz->reclaim_stat.recent_rotated[0];
2997 recent_rotated[1] +=
2998 mz->reclaim_stat.recent_rotated[1];
2999 recent_scanned[0] +=
3000 mz->reclaim_stat.recent_scanned[0];
3001 recent_scanned[1] +=
3002 mz->reclaim_stat.recent_scanned[1];
3004 cb->fill(cb, "recent_rotated_anon", recent_rotated[0]);
3005 cb->fill(cb, "recent_rotated_file", recent_rotated[1]);
3006 cb->fill(cb, "recent_scanned_anon", recent_scanned[0]);
3007 cb->fill(cb, "recent_scanned_file", recent_scanned[1]);
3014 static u64 mem_cgroup_swappiness_read(struct cgroup *cgrp, struct cftype *cft)
3016 struct mem_cgroup *memcg = mem_cgroup_from_cont(cgrp);
3018 return get_swappiness(memcg);
3021 static int mem_cgroup_swappiness_write(struct cgroup *cgrp, struct cftype *cft,
3024 struct mem_cgroup *memcg = mem_cgroup_from_cont(cgrp);
3025 struct mem_cgroup *parent;
3030 if (cgrp->parent == NULL)
3033 parent = mem_cgroup_from_cont(cgrp->parent);
3037 /* If under hierarchy, only empty-root can set this value */
3038 if ((parent->use_hierarchy) ||
3039 (memcg->use_hierarchy && !list_empty(&cgrp->children))) {
3044 spin_lock(&memcg->reclaim_param_lock);
3045 memcg->swappiness = val;
3046 spin_unlock(&memcg->reclaim_param_lock);
3054 static struct cftype mem_cgroup_files[] = {
3056 .name = "usage_in_bytes",
3057 .private = MEMFILE_PRIVATE(_MEM, RES_USAGE),
3058 .read_u64 = mem_cgroup_read,
3061 .name = "max_usage_in_bytes",
3062 .private = MEMFILE_PRIVATE(_MEM, RES_MAX_USAGE),
3063 .trigger = mem_cgroup_reset,
3064 .read_u64 = mem_cgroup_read,
3067 .name = "limit_in_bytes",
3068 .private = MEMFILE_PRIVATE(_MEM, RES_LIMIT),
3069 .write_string = mem_cgroup_write,
3070 .read_u64 = mem_cgroup_read,
3073 .name = "soft_limit_in_bytes",
3074 .private = MEMFILE_PRIVATE(_MEM, RES_SOFT_LIMIT),
3075 .write_string = mem_cgroup_write,
3076 .read_u64 = mem_cgroup_read,
3080 .private = MEMFILE_PRIVATE(_MEM, RES_FAILCNT),
3081 .trigger = mem_cgroup_reset,
3082 .read_u64 = mem_cgroup_read,
3086 .read_map = mem_control_stat_show,
3089 .name = "force_empty",
3090 .trigger = mem_cgroup_force_empty_write,
3093 .name = "use_hierarchy",
3094 .write_u64 = mem_cgroup_hierarchy_write,
3095 .read_u64 = mem_cgroup_hierarchy_read,
3098 .name = "swappiness",
3099 .read_u64 = mem_cgroup_swappiness_read,
3100 .write_u64 = mem_cgroup_swappiness_write,
3104 #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP
3105 static struct cftype memsw_cgroup_files[] = {
3107 .name = "memsw.usage_in_bytes",
3108 .private = MEMFILE_PRIVATE(_MEMSWAP, RES_USAGE),
3109 .read_u64 = mem_cgroup_read,
3112 .name = "memsw.max_usage_in_bytes",
3113 .private = MEMFILE_PRIVATE(_MEMSWAP, RES_MAX_USAGE),
3114 .trigger = mem_cgroup_reset,
3115 .read_u64 = mem_cgroup_read,
3118 .name = "memsw.limit_in_bytes",
3119 .private = MEMFILE_PRIVATE(_MEMSWAP, RES_LIMIT),
3120 .write_string = mem_cgroup_write,
3121 .read_u64 = mem_cgroup_read,
3124 .name = "memsw.failcnt",
3125 .private = MEMFILE_PRIVATE(_MEMSWAP, RES_FAILCNT),
3126 .trigger = mem_cgroup_reset,
3127 .read_u64 = mem_cgroup_read,
3131 static int register_memsw_files(struct cgroup *cont, struct cgroup_subsys *ss)
3133 if (!do_swap_account)
3135 return cgroup_add_files(cont, ss, memsw_cgroup_files,
3136 ARRAY_SIZE(memsw_cgroup_files));
3139 static int register_memsw_files(struct cgroup *cont, struct cgroup_subsys *ss)
3145 static int alloc_mem_cgroup_per_zone_info(struct mem_cgroup *mem, int node)
3147 struct mem_cgroup_per_node *pn;
3148 struct mem_cgroup_per_zone *mz;
3150 int zone, tmp = node;
3152 * This routine is called against possible nodes.
3153 * But it's BUG to call kmalloc() against offline node.
3155 * TODO: this routine can waste much memory for nodes which will
3156 * never be onlined. It's better to use memory hotplug callback
3159 if (!node_state(node, N_NORMAL_MEMORY))
3161 pn = kmalloc_node(sizeof(*pn), GFP_KERNEL, tmp);
3165 mem->info.nodeinfo[node] = pn;
3166 memset(pn, 0, sizeof(*pn));
3168 for (zone = 0; zone < MAX_NR_ZONES; zone++) {
3169 mz = &pn->zoneinfo[zone];
3171 INIT_LIST_HEAD(&mz->lists[l]);
3172 mz->usage_in_excess = 0;
3173 mz->on_tree = false;
3179 static void free_mem_cgroup_per_zone_info(struct mem_cgroup *mem, int node)
3181 kfree(mem->info.nodeinfo[node]);
3184 static int mem_cgroup_size(void)
3186 int cpustat_size = nr_cpu_ids * sizeof(struct mem_cgroup_stat_cpu);
3187 return sizeof(struct mem_cgroup) + cpustat_size;
3190 static struct mem_cgroup *mem_cgroup_alloc(void)
3192 struct mem_cgroup *mem;
3193 int size = mem_cgroup_size();
3195 if (size < PAGE_SIZE)
3196 mem = kmalloc(size, GFP_KERNEL);
3198 mem = vmalloc(size);
3201 memset(mem, 0, size);
3206 * At destroying mem_cgroup, references from swap_cgroup can remain.
3207 * (scanning all at force_empty is too costly...)
3209 * Instead of clearing all references at force_empty, we remember
3210 * the number of reference from swap_cgroup and free mem_cgroup when
3211 * it goes down to 0.
3213 * Removal of cgroup itself succeeds regardless of refs from swap.
3216 static void __mem_cgroup_free(struct mem_cgroup *mem)
3220 mem_cgroup_remove_from_trees(mem);
3221 free_css_id(&mem_cgroup_subsys, &mem->css);
3223 for_each_node_state(node, N_POSSIBLE)
3224 free_mem_cgroup_per_zone_info(mem, node);
3226 if (mem_cgroup_size() < PAGE_SIZE)
3232 static void mem_cgroup_get(struct mem_cgroup *mem)
3234 atomic_inc(&mem->refcnt);
3237 static void mem_cgroup_put(struct mem_cgroup *mem)
3239 if (atomic_dec_and_test(&mem->refcnt)) {
3240 struct mem_cgroup *parent = parent_mem_cgroup(mem);
3241 __mem_cgroup_free(mem);
3243 mem_cgroup_put(parent);
3248 * Returns the parent mem_cgroup in memcgroup hierarchy with hierarchy enabled.
3250 static struct mem_cgroup *parent_mem_cgroup(struct mem_cgroup *mem)
3252 if (!mem->res.parent)
3254 return mem_cgroup_from_res_counter(mem->res.parent, res);
3257 #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP
3258 static void __init enable_swap_cgroup(void)
3260 if (!mem_cgroup_disabled() && really_do_swap_account)
3261 do_swap_account = 1;
3264 static void __init enable_swap_cgroup(void)
3269 static int mem_cgroup_soft_limit_tree_init(void)
3271 struct mem_cgroup_tree_per_node *rtpn;
3272 struct mem_cgroup_tree_per_zone *rtpz;
3273 int tmp, node, zone;
3275 for_each_node_state(node, N_POSSIBLE) {
3277 if (!node_state(node, N_NORMAL_MEMORY))
3279 rtpn = kzalloc_node(sizeof(*rtpn), GFP_KERNEL, tmp);
3283 soft_limit_tree.rb_tree_per_node[node] = rtpn;
3285 for (zone = 0; zone < MAX_NR_ZONES; zone++) {
3286 rtpz = &rtpn->rb_tree_per_zone[zone];
3287 rtpz->rb_root = RB_ROOT;
3288 spin_lock_init(&rtpz->lock);
3294 static struct cgroup_subsys_state * __ref
3295 mem_cgroup_create(struct cgroup_subsys *ss, struct cgroup *cont)
3297 struct mem_cgroup *mem, *parent;
3298 long error = -ENOMEM;
3301 mem = mem_cgroup_alloc();
3303 return ERR_PTR(error);
3305 for_each_node_state(node, N_POSSIBLE)
3306 if (alloc_mem_cgroup_per_zone_info(mem, node))
3310 if (cont->parent == NULL) {
3312 enable_swap_cgroup();
3314 root_mem_cgroup = mem;
3315 if (mem_cgroup_soft_limit_tree_init())
3317 for_each_possible_cpu(cpu) {
3318 struct memcg_stock_pcp *stock =
3319 &per_cpu(memcg_stock, cpu);
3320 INIT_WORK(&stock->work, drain_local_stock);
3322 hotcpu_notifier(memcg_stock_cpu_callback, 0);
3325 parent = mem_cgroup_from_cont(cont->parent);
3326 mem->use_hierarchy = parent->use_hierarchy;
3329 if (parent && parent->use_hierarchy) {
3330 res_counter_init(&mem->res, &parent->res);
3331 res_counter_init(&mem->memsw, &parent->memsw);
3333 * We increment refcnt of the parent to ensure that we can
3334 * safely access it on res_counter_charge/uncharge.
3335 * This refcnt will be decremented when freeing this
3336 * mem_cgroup(see mem_cgroup_put).
3338 mem_cgroup_get(parent);
3340 res_counter_init(&mem->res, NULL);
3341 res_counter_init(&mem->memsw, NULL);
3343 mem->last_scanned_child = 0;
3344 spin_lock_init(&mem->reclaim_param_lock);
3347 mem->swappiness = get_swappiness(parent);
3348 atomic_set(&mem->refcnt, 1);
3351 __mem_cgroup_free(mem);
3352 root_mem_cgroup = NULL;
3353 return ERR_PTR(error);
3356 static int mem_cgroup_pre_destroy(struct cgroup_subsys *ss,
3357 struct cgroup *cont)
3359 struct mem_cgroup *mem = mem_cgroup_from_cont(cont);
3361 return mem_cgroup_force_empty(mem, false);
3364 static void mem_cgroup_destroy(struct cgroup_subsys *ss,
3365 struct cgroup *cont)
3367 struct mem_cgroup *mem = mem_cgroup_from_cont(cont);
3369 mem_cgroup_put(mem);
3372 static int mem_cgroup_populate(struct cgroup_subsys *ss,
3373 struct cgroup *cont)
3377 ret = cgroup_add_files(cont, ss, mem_cgroup_files,
3378 ARRAY_SIZE(mem_cgroup_files));
3381 ret = register_memsw_files(cont, ss);
3385 static void mem_cgroup_move_task(struct cgroup_subsys *ss,
3386 struct cgroup *cont,
3387 struct cgroup *old_cont,
3388 struct task_struct *p,
3392 * FIXME: It's better to move charges of this process from old
3393 * memcg to new memcg. But it's just on TODO-List now.
3397 struct cgroup_subsys mem_cgroup_subsys = {
3399 .subsys_id = mem_cgroup_subsys_id,
3400 .create = mem_cgroup_create,
3401 .pre_destroy = mem_cgroup_pre_destroy,
3402 .destroy = mem_cgroup_destroy,
3403 .populate = mem_cgroup_populate,
3404 .attach = mem_cgroup_move_task,
3409 #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP
3411 static int __init disable_swap_account(char *s)
3413 really_do_swap_account = 0;
3416 __setup("noswapaccount", disable_swap_account);