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>
10 * Copyright (C) 2009 Nokia Corporation
11 * Author: Kirill A. Shutemov
13 * This program is free software; you can redistribute it and/or modify
14 * it under the terms of the GNU General Public License as published by
15 * the Free Software Foundation; either version 2 of the License, or
16 * (at your option) any later version.
18 * This program is distributed in the hope that it will be useful,
19 * but WITHOUT ANY WARRANTY; without even the implied warranty of
20 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
21 * GNU General Public License for more details.
24 #include <linux/res_counter.h>
25 #include <linux/memcontrol.h>
26 #include <linux/cgroup.h>
28 #include <linux/hugetlb.h>
29 #include <linux/pagemap.h>
30 #include <linux/smp.h>
31 #include <linux/page-flags.h>
32 #include <linux/backing-dev.h>
33 #include <linux/bit_spinlock.h>
34 #include <linux/rcupdate.h>
35 #include <linux/limits.h>
36 #include <linux/mutex.h>
37 #include <linux/rbtree.h>
38 #include <linux/slab.h>
39 #include <linux/swap.h>
40 #include <linux/swapops.h>
41 #include <linux/spinlock.h>
42 #include <linux/eventfd.h>
43 #include <linux/sort.h>
45 #include <linux/seq_file.h>
46 #include <linux/vmalloc.h>
47 #include <linux/mm_inline.h>
48 #include <linux/page_cgroup.h>
49 #include <linux/cpu.h>
50 #include <linux/oom.h>
53 #include <asm/uaccess.h>
55 #include <trace/events/vmscan.h>
57 struct cgroup_subsys mem_cgroup_subsys __read_mostly;
58 #define MEM_CGROUP_RECLAIM_RETRIES 5
59 struct mem_cgroup *root_mem_cgroup __read_mostly;
61 #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP
62 /* Turned on only when memory cgroup is enabled && really_do_swap_account = 1 */
63 int do_swap_account __read_mostly;
65 /* for remember boot option*/
66 #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP_ENABLED
67 static int really_do_swap_account __initdata = 1;
69 static int really_do_swap_account __initdata = 0;
73 #define do_swap_account (0)
77 * Per memcg event counter is incremented at every pagein/pageout. This counter
78 * is used for trigger some periodic events. This is straightforward and better
79 * than using jiffies etc. to handle periodic memcg event.
81 * These values will be used as !((event) & ((1 <<(thresh)) - 1))
83 #define THRESHOLDS_EVENTS_THRESH (7) /* once in 128 */
84 #define SOFTLIMIT_EVENTS_THRESH (10) /* once in 1024 */
87 * Statistics for memory cgroup.
89 enum mem_cgroup_stat_index {
91 * For MEM_CONTAINER_TYPE_ALL, usage = pagecache + rss.
93 MEM_CGROUP_STAT_CACHE, /* # of pages charged as cache */
94 MEM_CGROUP_STAT_RSS, /* # of pages charged as anon rss */
95 MEM_CGROUP_STAT_FILE_MAPPED, /* # of pages charged as file rss */
96 MEM_CGROUP_STAT_PGPGIN_COUNT, /* # of pages paged in */
97 MEM_CGROUP_STAT_PGPGOUT_COUNT, /* # of pages paged out */
98 MEM_CGROUP_STAT_SWAPOUT, /* # of pages, swapped out */
99 MEM_CGROUP_STAT_DATA, /* end of data requires synchronization */
100 /* incremented at every pagein/pageout */
101 MEM_CGROUP_EVENTS = MEM_CGROUP_STAT_DATA,
102 MEM_CGROUP_ON_MOVE, /* someone is moving account between groups */
104 MEM_CGROUP_STAT_NSTATS,
107 struct mem_cgroup_stat_cpu {
108 s64 count[MEM_CGROUP_STAT_NSTATS];
112 * per-zone information in memory controller.
114 struct mem_cgroup_per_zone {
116 * spin_lock to protect the per cgroup LRU
118 struct list_head lists[NR_LRU_LISTS];
119 unsigned long count[NR_LRU_LISTS];
121 struct zone_reclaim_stat reclaim_stat;
122 struct rb_node tree_node; /* RB tree node */
123 unsigned long long usage_in_excess;/* Set to the value by which */
124 /* the soft limit is exceeded*/
126 struct mem_cgroup *mem; /* Back pointer, we cannot */
127 /* use container_of */
129 /* Macro for accessing counter */
130 #define MEM_CGROUP_ZSTAT(mz, idx) ((mz)->count[(idx)])
132 struct mem_cgroup_per_node {
133 struct mem_cgroup_per_zone zoneinfo[MAX_NR_ZONES];
136 struct mem_cgroup_lru_info {
137 struct mem_cgroup_per_node *nodeinfo[MAX_NUMNODES];
141 * Cgroups above their limits are maintained in a RB-Tree, independent of
142 * their hierarchy representation
145 struct mem_cgroup_tree_per_zone {
146 struct rb_root rb_root;
150 struct mem_cgroup_tree_per_node {
151 struct mem_cgroup_tree_per_zone rb_tree_per_zone[MAX_NR_ZONES];
154 struct mem_cgroup_tree {
155 struct mem_cgroup_tree_per_node *rb_tree_per_node[MAX_NUMNODES];
158 static struct mem_cgroup_tree soft_limit_tree __read_mostly;
160 struct mem_cgroup_threshold {
161 struct eventfd_ctx *eventfd;
166 struct mem_cgroup_threshold_ary {
167 /* An array index points to threshold just below usage. */
168 int current_threshold;
169 /* Size of entries[] */
171 /* Array of thresholds */
172 struct mem_cgroup_threshold entries[0];
175 struct mem_cgroup_thresholds {
176 /* Primary thresholds array */
177 struct mem_cgroup_threshold_ary *primary;
179 * Spare threshold array.
180 * This is needed to make mem_cgroup_unregister_event() "never fail".
181 * It must be able to store at least primary->size - 1 entries.
183 struct mem_cgroup_threshold_ary *spare;
187 struct mem_cgroup_eventfd_list {
188 struct list_head list;
189 struct eventfd_ctx *eventfd;
192 static void mem_cgroup_threshold(struct mem_cgroup *mem);
193 static void mem_cgroup_oom_notify(struct mem_cgroup *mem);
196 * The memory controller data structure. The memory controller controls both
197 * page cache and RSS per cgroup. We would eventually like to provide
198 * statistics based on the statistics developed by Rik Van Riel for clock-pro,
199 * to help the administrator determine what knobs to tune.
201 * TODO: Add a water mark for the memory controller. Reclaim will begin when
202 * we hit the water mark. May be even add a low water mark, such that
203 * no reclaim occurs from a cgroup at it's low water mark, this is
204 * a feature that will be implemented much later in the future.
207 struct cgroup_subsys_state css;
209 * the counter to account for memory usage
211 struct res_counter res;
213 * the counter to account for mem+swap usage.
215 struct res_counter memsw;
217 * Per cgroup active and inactive list, similar to the
218 * per zone LRU lists.
220 struct mem_cgroup_lru_info info;
223 protect against reclaim related member.
225 spinlock_t reclaim_param_lock;
228 * While reclaiming in a hierarchy, we cache the last child we
231 int last_scanned_child;
233 * Should the accounting and control be hierarchical, per subtree?
239 unsigned int swappiness;
240 /* OOM-Killer disable */
241 int oom_kill_disable;
243 /* set when res.limit == memsw.limit */
244 bool memsw_is_minimum;
246 /* protect arrays of thresholds */
247 struct mutex thresholds_lock;
249 /* thresholds for memory usage. RCU-protected */
250 struct mem_cgroup_thresholds thresholds;
252 /* thresholds for mem+swap usage. RCU-protected */
253 struct mem_cgroup_thresholds memsw_thresholds;
255 /* For oom notifier event fd */
256 struct list_head oom_notify;
259 * Should we move charges of a task when a task is moved into this
260 * mem_cgroup ? And what type of charges should we move ?
262 unsigned long move_charge_at_immigrate;
266 struct mem_cgroup_stat_cpu *stat;
268 * used when a cpu is offlined or other synchronizations
269 * See mem_cgroup_read_stat().
271 struct mem_cgroup_stat_cpu nocpu_base;
272 spinlock_t pcp_counter_lock;
275 /* Stuffs for move charges at task migration. */
277 * Types of charges to be moved. "move_charge_at_immitgrate" is treated as a
278 * left-shifted bitmap of these types.
281 MOVE_CHARGE_TYPE_ANON, /* private anonymous page and swap of it */
282 MOVE_CHARGE_TYPE_FILE, /* file page(including tmpfs) and swap of it */
286 /* "mc" and its members are protected by cgroup_mutex */
287 static struct move_charge_struct {
288 spinlock_t lock; /* for from, to */
289 struct mem_cgroup *from;
290 struct mem_cgroup *to;
291 unsigned long precharge;
292 unsigned long moved_charge;
293 unsigned long moved_swap;
294 struct task_struct *moving_task; /* a task moving charges */
295 wait_queue_head_t waitq; /* a waitq for other context */
297 .lock = __SPIN_LOCK_UNLOCKED(mc.lock),
298 .waitq = __WAIT_QUEUE_HEAD_INITIALIZER(mc.waitq),
301 static bool move_anon(void)
303 return test_bit(MOVE_CHARGE_TYPE_ANON,
304 &mc.to->move_charge_at_immigrate);
307 static bool move_file(void)
309 return test_bit(MOVE_CHARGE_TYPE_FILE,
310 &mc.to->move_charge_at_immigrate);
314 * Maximum loops in mem_cgroup_hierarchical_reclaim(), used for soft
315 * limit reclaim to prevent infinite loops, if they ever occur.
317 #define MEM_CGROUP_MAX_RECLAIM_LOOPS (100)
318 #define MEM_CGROUP_MAX_SOFT_LIMIT_RECLAIM_LOOPS (2)
321 MEM_CGROUP_CHARGE_TYPE_CACHE = 0,
322 MEM_CGROUP_CHARGE_TYPE_MAPPED,
323 MEM_CGROUP_CHARGE_TYPE_SHMEM, /* used by page migration of shmem */
324 MEM_CGROUP_CHARGE_TYPE_FORCE, /* used by force_empty */
325 MEM_CGROUP_CHARGE_TYPE_SWAPOUT, /* for accounting swapcache */
326 MEM_CGROUP_CHARGE_TYPE_DROP, /* a page was unused swap cache */
330 /* only for here (for easy reading.) */
331 #define PCGF_CACHE (1UL << PCG_CACHE)
332 #define PCGF_USED (1UL << PCG_USED)
333 #define PCGF_LOCK (1UL << PCG_LOCK)
334 /* Not used, but added here for completeness */
335 #define PCGF_ACCT (1UL << PCG_ACCT)
337 /* for encoding cft->private value on file */
340 #define _OOM_TYPE (2)
341 #define MEMFILE_PRIVATE(x, val) (((x) << 16) | (val))
342 #define MEMFILE_TYPE(val) (((val) >> 16) & 0xffff)
343 #define MEMFILE_ATTR(val) ((val) & 0xffff)
344 /* Used for OOM nofiier */
345 #define OOM_CONTROL (0)
348 * Reclaim flags for mem_cgroup_hierarchical_reclaim
350 #define MEM_CGROUP_RECLAIM_NOSWAP_BIT 0x0
351 #define MEM_CGROUP_RECLAIM_NOSWAP (1 << MEM_CGROUP_RECLAIM_NOSWAP_BIT)
352 #define MEM_CGROUP_RECLAIM_SHRINK_BIT 0x1
353 #define MEM_CGROUP_RECLAIM_SHRINK (1 << MEM_CGROUP_RECLAIM_SHRINK_BIT)
354 #define MEM_CGROUP_RECLAIM_SOFT_BIT 0x2
355 #define MEM_CGROUP_RECLAIM_SOFT (1 << MEM_CGROUP_RECLAIM_SOFT_BIT)
357 static void mem_cgroup_get(struct mem_cgroup *mem);
358 static void mem_cgroup_put(struct mem_cgroup *mem);
359 static struct mem_cgroup *parent_mem_cgroup(struct mem_cgroup *mem);
360 static void drain_all_stock_async(void);
362 static struct mem_cgroup_per_zone *
363 mem_cgroup_zoneinfo(struct mem_cgroup *mem, int nid, int zid)
365 return &mem->info.nodeinfo[nid]->zoneinfo[zid];
368 struct cgroup_subsys_state *mem_cgroup_css(struct mem_cgroup *mem)
373 static struct mem_cgroup_per_zone *
374 page_cgroup_zoneinfo(struct page_cgroup *pc)
376 struct mem_cgroup *mem = pc->mem_cgroup;
377 int nid = page_cgroup_nid(pc);
378 int zid = page_cgroup_zid(pc);
383 return mem_cgroup_zoneinfo(mem, nid, zid);
386 static struct mem_cgroup_tree_per_zone *
387 soft_limit_tree_node_zone(int nid, int zid)
389 return &soft_limit_tree.rb_tree_per_node[nid]->rb_tree_per_zone[zid];
392 static struct mem_cgroup_tree_per_zone *
393 soft_limit_tree_from_page(struct page *page)
395 int nid = page_to_nid(page);
396 int zid = page_zonenum(page);
398 return &soft_limit_tree.rb_tree_per_node[nid]->rb_tree_per_zone[zid];
402 __mem_cgroup_insert_exceeded(struct mem_cgroup *mem,
403 struct mem_cgroup_per_zone *mz,
404 struct mem_cgroup_tree_per_zone *mctz,
405 unsigned long long new_usage_in_excess)
407 struct rb_node **p = &mctz->rb_root.rb_node;
408 struct rb_node *parent = NULL;
409 struct mem_cgroup_per_zone *mz_node;
414 mz->usage_in_excess = new_usage_in_excess;
415 if (!mz->usage_in_excess)
419 mz_node = rb_entry(parent, struct mem_cgroup_per_zone,
421 if (mz->usage_in_excess < mz_node->usage_in_excess)
424 * We can't avoid mem cgroups that are over their soft
425 * limit by the same amount
427 else if (mz->usage_in_excess >= mz_node->usage_in_excess)
430 rb_link_node(&mz->tree_node, parent, p);
431 rb_insert_color(&mz->tree_node, &mctz->rb_root);
436 __mem_cgroup_remove_exceeded(struct mem_cgroup *mem,
437 struct mem_cgroup_per_zone *mz,
438 struct mem_cgroup_tree_per_zone *mctz)
442 rb_erase(&mz->tree_node, &mctz->rb_root);
447 mem_cgroup_remove_exceeded(struct mem_cgroup *mem,
448 struct mem_cgroup_per_zone *mz,
449 struct mem_cgroup_tree_per_zone *mctz)
451 spin_lock(&mctz->lock);
452 __mem_cgroup_remove_exceeded(mem, mz, mctz);
453 spin_unlock(&mctz->lock);
457 static void mem_cgroup_update_tree(struct mem_cgroup *mem, struct page *page)
459 unsigned long long excess;
460 struct mem_cgroup_per_zone *mz;
461 struct mem_cgroup_tree_per_zone *mctz;
462 int nid = page_to_nid(page);
463 int zid = page_zonenum(page);
464 mctz = soft_limit_tree_from_page(page);
467 * Necessary to update all ancestors when hierarchy is used.
468 * because their event counter is not touched.
470 for (; mem; mem = parent_mem_cgroup(mem)) {
471 mz = mem_cgroup_zoneinfo(mem, nid, zid);
472 excess = res_counter_soft_limit_excess(&mem->res);
474 * We have to update the tree if mz is on RB-tree or
475 * mem is over its softlimit.
477 if (excess || mz->on_tree) {
478 spin_lock(&mctz->lock);
479 /* if on-tree, remove it */
481 __mem_cgroup_remove_exceeded(mem, mz, mctz);
483 * Insert again. mz->usage_in_excess will be updated.
484 * If excess is 0, no tree ops.
486 __mem_cgroup_insert_exceeded(mem, mz, mctz, excess);
487 spin_unlock(&mctz->lock);
492 static void mem_cgroup_remove_from_trees(struct mem_cgroup *mem)
495 struct mem_cgroup_per_zone *mz;
496 struct mem_cgroup_tree_per_zone *mctz;
498 for_each_node_state(node, N_POSSIBLE) {
499 for (zone = 0; zone < MAX_NR_ZONES; zone++) {
500 mz = mem_cgroup_zoneinfo(mem, node, zone);
501 mctz = soft_limit_tree_node_zone(node, zone);
502 mem_cgroup_remove_exceeded(mem, mz, mctz);
507 static inline unsigned long mem_cgroup_get_excess(struct mem_cgroup *mem)
509 return res_counter_soft_limit_excess(&mem->res) >> PAGE_SHIFT;
512 static struct mem_cgroup_per_zone *
513 __mem_cgroup_largest_soft_limit_node(struct mem_cgroup_tree_per_zone *mctz)
515 struct rb_node *rightmost = NULL;
516 struct mem_cgroup_per_zone *mz;
520 rightmost = rb_last(&mctz->rb_root);
522 goto done; /* Nothing to reclaim from */
524 mz = rb_entry(rightmost, struct mem_cgroup_per_zone, tree_node);
526 * Remove the node now but someone else can add it back,
527 * we will to add it back at the end of reclaim to its correct
528 * position in the tree.
530 __mem_cgroup_remove_exceeded(mz->mem, mz, mctz);
531 if (!res_counter_soft_limit_excess(&mz->mem->res) ||
532 !css_tryget(&mz->mem->css))
538 static struct mem_cgroup_per_zone *
539 mem_cgroup_largest_soft_limit_node(struct mem_cgroup_tree_per_zone *mctz)
541 struct mem_cgroup_per_zone *mz;
543 spin_lock(&mctz->lock);
544 mz = __mem_cgroup_largest_soft_limit_node(mctz);
545 spin_unlock(&mctz->lock);
550 * Implementation Note: reading percpu statistics for memcg.
552 * Both of vmstat[] and percpu_counter has threshold and do periodic
553 * synchronization to implement "quick" read. There are trade-off between
554 * reading cost and precision of value. Then, we may have a chance to implement
555 * a periodic synchronizion of counter in memcg's counter.
557 * But this _read() function is used for user interface now. The user accounts
558 * memory usage by memory cgroup and he _always_ requires exact value because
559 * he accounts memory. Even if we provide quick-and-fuzzy read, we always
560 * have to visit all online cpus and make sum. So, for now, unnecessary
561 * synchronization is not implemented. (just implemented for cpu hotplug)
563 * If there are kernel internal actions which can make use of some not-exact
564 * value, and reading all cpu value can be performance bottleneck in some
565 * common workload, threashold and synchonization as vmstat[] should be
568 static s64 mem_cgroup_read_stat(struct mem_cgroup *mem,
569 enum mem_cgroup_stat_index idx)
575 for_each_online_cpu(cpu)
576 val += per_cpu(mem->stat->count[idx], cpu);
577 #ifdef CONFIG_HOTPLUG_CPU
578 spin_lock(&mem->pcp_counter_lock);
579 val += mem->nocpu_base.count[idx];
580 spin_unlock(&mem->pcp_counter_lock);
586 static s64 mem_cgroup_local_usage(struct mem_cgroup *mem)
590 ret = mem_cgroup_read_stat(mem, MEM_CGROUP_STAT_RSS);
591 ret += mem_cgroup_read_stat(mem, MEM_CGROUP_STAT_CACHE);
595 static void mem_cgroup_swap_statistics(struct mem_cgroup *mem,
598 int val = (charge) ? 1 : -1;
599 this_cpu_add(mem->stat->count[MEM_CGROUP_STAT_SWAPOUT], val);
602 static void mem_cgroup_charge_statistics(struct mem_cgroup *mem,
603 bool file, int nr_pages)
608 __this_cpu_add(mem->stat->count[MEM_CGROUP_STAT_CACHE], nr_pages);
610 __this_cpu_add(mem->stat->count[MEM_CGROUP_STAT_RSS], nr_pages);
612 /* pagein of a big page is an event. So, ignore page size */
614 __this_cpu_inc(mem->stat->count[MEM_CGROUP_STAT_PGPGIN_COUNT]);
616 __this_cpu_inc(mem->stat->count[MEM_CGROUP_STAT_PGPGOUT_COUNT]);
618 __this_cpu_add(mem->stat->count[MEM_CGROUP_EVENTS], nr_pages);
623 static unsigned long mem_cgroup_get_local_zonestat(struct mem_cgroup *mem,
627 struct mem_cgroup_per_zone *mz;
630 for_each_online_node(nid)
631 for (zid = 0; zid < MAX_NR_ZONES; zid++) {
632 mz = mem_cgroup_zoneinfo(mem, nid, zid);
633 total += MEM_CGROUP_ZSTAT(mz, idx);
638 static bool __memcg_event_check(struct mem_cgroup *mem, int event_mask_shift)
642 val = this_cpu_read(mem->stat->count[MEM_CGROUP_EVENTS]);
644 return !(val & ((1 << event_mask_shift) - 1));
648 * Check events in order.
651 static void memcg_check_events(struct mem_cgroup *mem, struct page *page)
653 /* threshold event is triggered in finer grain than soft limit */
654 if (unlikely(__memcg_event_check(mem, THRESHOLDS_EVENTS_THRESH))) {
655 mem_cgroup_threshold(mem);
656 if (unlikely(__memcg_event_check(mem, SOFTLIMIT_EVENTS_THRESH)))
657 mem_cgroup_update_tree(mem, page);
661 static struct mem_cgroup *mem_cgroup_from_cont(struct cgroup *cont)
663 return container_of(cgroup_subsys_state(cont,
664 mem_cgroup_subsys_id), struct mem_cgroup,
668 struct mem_cgroup *mem_cgroup_from_task(struct task_struct *p)
671 * mm_update_next_owner() may clear mm->owner to NULL
672 * if it races with swapoff, page migration, etc.
673 * So this can be called with p == NULL.
678 return container_of(task_subsys_state(p, mem_cgroup_subsys_id),
679 struct mem_cgroup, css);
682 static struct mem_cgroup *try_get_mem_cgroup_from_mm(struct mm_struct *mm)
684 struct mem_cgroup *mem = NULL;
689 * Because we have no locks, mm->owner's may be being moved to other
690 * cgroup. We use css_tryget() here even if this looks
691 * pessimistic (rather than adding locks here).
695 mem = mem_cgroup_from_task(rcu_dereference(mm->owner));
698 } while (!css_tryget(&mem->css));
703 /* The caller has to guarantee "mem" exists before calling this */
704 static struct mem_cgroup *mem_cgroup_start_loop(struct mem_cgroup *mem)
706 struct cgroup_subsys_state *css;
709 if (!mem) /* ROOT cgroup has the smallest ID */
710 return root_mem_cgroup; /*css_put/get against root is ignored*/
711 if (!mem->use_hierarchy) {
712 if (css_tryget(&mem->css))
718 * searching a memory cgroup which has the smallest ID under given
719 * ROOT cgroup. (ID >= 1)
721 css = css_get_next(&mem_cgroup_subsys, 1, &mem->css, &found);
722 if (css && css_tryget(css))
723 mem = container_of(css, struct mem_cgroup, css);
730 static struct mem_cgroup *mem_cgroup_get_next(struct mem_cgroup *iter,
731 struct mem_cgroup *root,
734 int nextid = css_id(&iter->css) + 1;
737 struct cgroup_subsys_state *css;
739 hierarchy_used = iter->use_hierarchy;
742 /* If no ROOT, walk all, ignore hierarchy */
743 if (!cond || (root && !hierarchy_used))
747 root = root_mem_cgroup;
753 css = css_get_next(&mem_cgroup_subsys, nextid,
755 if (css && css_tryget(css))
756 iter = container_of(css, struct mem_cgroup, css);
758 /* If css is NULL, no more cgroups will be found */
760 } while (css && !iter);
765 * for_eacn_mem_cgroup_tree() for visiting all cgroup under tree. Please
766 * be careful that "break" loop is not allowed. We have reference count.
767 * Instead of that modify "cond" to be false and "continue" to exit the loop.
769 #define for_each_mem_cgroup_tree_cond(iter, root, cond) \
770 for (iter = mem_cgroup_start_loop(root);\
772 iter = mem_cgroup_get_next(iter, root, cond))
774 #define for_each_mem_cgroup_tree(iter, root) \
775 for_each_mem_cgroup_tree_cond(iter, root, true)
777 #define for_each_mem_cgroup_all(iter) \
778 for_each_mem_cgroup_tree_cond(iter, NULL, true)
781 static inline bool mem_cgroup_is_root(struct mem_cgroup *mem)
783 return (mem == root_mem_cgroup);
787 * Following LRU functions are allowed to be used without PCG_LOCK.
788 * Operations are called by routine of global LRU independently from memcg.
789 * What we have to take care of here is validness of pc->mem_cgroup.
791 * Changes to pc->mem_cgroup happens when
794 * In typical case, "charge" is done before add-to-lru. Exception is SwapCache.
795 * It is added to LRU before charge.
796 * If PCG_USED bit is not set, page_cgroup is not added to this private LRU.
797 * When moving account, the page is not on LRU. It's isolated.
800 void mem_cgroup_del_lru_list(struct page *page, enum lru_list lru)
802 struct page_cgroup *pc;
803 struct mem_cgroup_per_zone *mz;
805 if (mem_cgroup_disabled())
807 pc = lookup_page_cgroup(page);
808 /* can happen while we handle swapcache. */
809 if (!TestClearPageCgroupAcctLRU(pc))
811 VM_BUG_ON(!pc->mem_cgroup);
813 * We don't check PCG_USED bit. It's cleared when the "page" is finally
814 * removed from global LRU.
816 mz = page_cgroup_zoneinfo(pc);
817 /* huge page split is done under lru_lock. so, we have no races. */
818 MEM_CGROUP_ZSTAT(mz, lru) -= 1 << compound_order(page);
819 if (mem_cgroup_is_root(pc->mem_cgroup))
821 VM_BUG_ON(list_empty(&pc->lru));
822 list_del_init(&pc->lru);
825 void mem_cgroup_del_lru(struct page *page)
827 mem_cgroup_del_lru_list(page, page_lru(page));
830 void mem_cgroup_rotate_lru_list(struct page *page, enum lru_list lru)
832 struct mem_cgroup_per_zone *mz;
833 struct page_cgroup *pc;
835 if (mem_cgroup_disabled())
838 pc = lookup_page_cgroup(page);
839 /* unused or root page is not rotated. */
840 if (!PageCgroupUsed(pc))
842 /* Ensure pc->mem_cgroup is visible after reading PCG_USED. */
844 if (mem_cgroup_is_root(pc->mem_cgroup))
846 mz = page_cgroup_zoneinfo(pc);
847 list_move(&pc->lru, &mz->lists[lru]);
850 void mem_cgroup_add_lru_list(struct page *page, enum lru_list lru)
852 struct page_cgroup *pc;
853 struct mem_cgroup_per_zone *mz;
855 if (mem_cgroup_disabled())
857 pc = lookup_page_cgroup(page);
858 VM_BUG_ON(PageCgroupAcctLRU(pc));
859 if (!PageCgroupUsed(pc))
861 /* Ensure pc->mem_cgroup is visible after reading PCG_USED. */
863 mz = page_cgroup_zoneinfo(pc);
864 /* huge page split is done under lru_lock. so, we have no races. */
865 MEM_CGROUP_ZSTAT(mz, lru) += 1 << compound_order(page);
866 SetPageCgroupAcctLRU(pc);
867 if (mem_cgroup_is_root(pc->mem_cgroup))
869 list_add(&pc->lru, &mz->lists[lru]);
873 * At handling SwapCache, pc->mem_cgroup may be changed while it's linked to
874 * lru because the page may.be reused after it's fully uncharged (because of
875 * SwapCache behavior).To handle that, unlink page_cgroup from LRU when charge
876 * it again. This function is only used to charge SwapCache. It's done under
877 * lock_page and expected that zone->lru_lock is never held.
879 static void mem_cgroup_lru_del_before_commit_swapcache(struct page *page)
882 struct zone *zone = page_zone(page);
883 struct page_cgroup *pc = lookup_page_cgroup(page);
885 spin_lock_irqsave(&zone->lru_lock, flags);
887 * Forget old LRU when this page_cgroup is *not* used. This Used bit
888 * is guarded by lock_page() because the page is SwapCache.
890 if (!PageCgroupUsed(pc))
891 mem_cgroup_del_lru_list(page, page_lru(page));
892 spin_unlock_irqrestore(&zone->lru_lock, flags);
895 static void mem_cgroup_lru_add_after_commit_swapcache(struct page *page)
898 struct zone *zone = page_zone(page);
899 struct page_cgroup *pc = lookup_page_cgroup(page);
901 spin_lock_irqsave(&zone->lru_lock, flags);
902 /* link when the page is linked to LRU but page_cgroup isn't */
903 if (PageLRU(page) && !PageCgroupAcctLRU(pc))
904 mem_cgroup_add_lru_list(page, page_lru(page));
905 spin_unlock_irqrestore(&zone->lru_lock, flags);
909 void mem_cgroup_move_lists(struct page *page,
910 enum lru_list from, enum lru_list to)
912 if (mem_cgroup_disabled())
914 mem_cgroup_del_lru_list(page, from);
915 mem_cgroup_add_lru_list(page, to);
918 int task_in_mem_cgroup(struct task_struct *task, const struct mem_cgroup *mem)
921 struct mem_cgroup *curr = NULL;
922 struct task_struct *p;
924 p = find_lock_task_mm(task);
927 curr = try_get_mem_cgroup_from_mm(p->mm);
932 * We should check use_hierarchy of "mem" not "curr". Because checking
933 * use_hierarchy of "curr" here make this function true if hierarchy is
934 * enabled in "curr" and "curr" is a child of "mem" in *cgroup*
935 * hierarchy(even if use_hierarchy is disabled in "mem").
937 if (mem->use_hierarchy)
938 ret = css_is_ancestor(&curr->css, &mem->css);
945 static int calc_inactive_ratio(struct mem_cgroup *memcg, unsigned long *present_pages)
947 unsigned long active;
948 unsigned long inactive;
950 unsigned long inactive_ratio;
952 inactive = mem_cgroup_get_local_zonestat(memcg, LRU_INACTIVE_ANON);
953 active = mem_cgroup_get_local_zonestat(memcg, LRU_ACTIVE_ANON);
955 gb = (inactive + active) >> (30 - PAGE_SHIFT);
957 inactive_ratio = int_sqrt(10 * gb);
962 present_pages[0] = inactive;
963 present_pages[1] = active;
966 return inactive_ratio;
969 int mem_cgroup_inactive_anon_is_low(struct mem_cgroup *memcg)
971 unsigned long active;
972 unsigned long inactive;
973 unsigned long present_pages[2];
974 unsigned long inactive_ratio;
976 inactive_ratio = calc_inactive_ratio(memcg, present_pages);
978 inactive = present_pages[0];
979 active = present_pages[1];
981 if (inactive * inactive_ratio < active)
987 int mem_cgroup_inactive_file_is_low(struct mem_cgroup *memcg)
989 unsigned long active;
990 unsigned long inactive;
992 inactive = mem_cgroup_get_local_zonestat(memcg, LRU_INACTIVE_FILE);
993 active = mem_cgroup_get_local_zonestat(memcg, LRU_ACTIVE_FILE);
995 return (active > inactive);
998 unsigned long mem_cgroup_zone_nr_pages(struct mem_cgroup *memcg,
1002 int nid = zone_to_nid(zone);
1003 int zid = zone_idx(zone);
1004 struct mem_cgroup_per_zone *mz = mem_cgroup_zoneinfo(memcg, nid, zid);
1006 return MEM_CGROUP_ZSTAT(mz, lru);
1009 struct zone_reclaim_stat *mem_cgroup_get_reclaim_stat(struct mem_cgroup *memcg,
1012 int nid = zone_to_nid(zone);
1013 int zid = zone_idx(zone);
1014 struct mem_cgroup_per_zone *mz = mem_cgroup_zoneinfo(memcg, nid, zid);
1016 return &mz->reclaim_stat;
1019 struct zone_reclaim_stat *
1020 mem_cgroup_get_reclaim_stat_from_page(struct page *page)
1022 struct page_cgroup *pc;
1023 struct mem_cgroup_per_zone *mz;
1025 if (mem_cgroup_disabled())
1028 pc = lookup_page_cgroup(page);
1029 if (!PageCgroupUsed(pc))
1031 /* Ensure pc->mem_cgroup is visible after reading PCG_USED. */
1033 mz = page_cgroup_zoneinfo(pc);
1037 return &mz->reclaim_stat;
1040 unsigned long mem_cgroup_isolate_pages(unsigned long nr_to_scan,
1041 struct list_head *dst,
1042 unsigned long *scanned, int order,
1043 int mode, struct zone *z,
1044 struct mem_cgroup *mem_cont,
1045 int active, int file)
1047 unsigned long nr_taken = 0;
1051 struct list_head *src;
1052 struct page_cgroup *pc, *tmp;
1053 int nid = zone_to_nid(z);
1054 int zid = zone_idx(z);
1055 struct mem_cgroup_per_zone *mz;
1056 int lru = LRU_FILE * file + active;
1060 mz = mem_cgroup_zoneinfo(mem_cont, nid, zid);
1061 src = &mz->lists[lru];
1064 list_for_each_entry_safe_reverse(pc, tmp, src, lru) {
1065 if (scan >= nr_to_scan)
1069 if (unlikely(!PageCgroupUsed(pc)))
1071 if (unlikely(!PageLRU(page)))
1075 ret = __isolate_lru_page(page, mode, file);
1078 list_move(&page->lru, dst);
1079 mem_cgroup_del_lru(page);
1080 nr_taken += hpage_nr_pages(page);
1083 /* we don't affect global LRU but rotate in our LRU */
1084 mem_cgroup_rotate_lru_list(page, page_lru(page));
1093 trace_mm_vmscan_memcg_isolate(0, nr_to_scan, scan, nr_taken,
1099 #define mem_cgroup_from_res_counter(counter, member) \
1100 container_of(counter, struct mem_cgroup, member)
1102 static bool mem_cgroup_check_under_limit(struct mem_cgroup *mem)
1104 if (do_swap_account) {
1105 if (res_counter_check_under_limit(&mem->res) &&
1106 res_counter_check_under_limit(&mem->memsw))
1109 if (res_counter_check_under_limit(&mem->res))
1114 static unsigned int get_swappiness(struct mem_cgroup *memcg)
1116 struct cgroup *cgrp = memcg->css.cgroup;
1117 unsigned int swappiness;
1120 if (cgrp->parent == NULL)
1121 return vm_swappiness;
1123 spin_lock(&memcg->reclaim_param_lock);
1124 swappiness = memcg->swappiness;
1125 spin_unlock(&memcg->reclaim_param_lock);
1130 static void mem_cgroup_start_move(struct mem_cgroup *mem)
1135 spin_lock(&mem->pcp_counter_lock);
1136 for_each_online_cpu(cpu)
1137 per_cpu(mem->stat->count[MEM_CGROUP_ON_MOVE], cpu) += 1;
1138 mem->nocpu_base.count[MEM_CGROUP_ON_MOVE] += 1;
1139 spin_unlock(&mem->pcp_counter_lock);
1145 static void mem_cgroup_end_move(struct mem_cgroup *mem)
1152 spin_lock(&mem->pcp_counter_lock);
1153 for_each_online_cpu(cpu)
1154 per_cpu(mem->stat->count[MEM_CGROUP_ON_MOVE], cpu) -= 1;
1155 mem->nocpu_base.count[MEM_CGROUP_ON_MOVE] -= 1;
1156 spin_unlock(&mem->pcp_counter_lock);
1160 * 2 routines for checking "mem" is under move_account() or not.
1162 * mem_cgroup_stealed() - checking a cgroup is mc.from or not. This is used
1163 * for avoiding race in accounting. If true,
1164 * pc->mem_cgroup may be overwritten.
1166 * mem_cgroup_under_move() - checking a cgroup is mc.from or mc.to or
1167 * under hierarchy of moving cgroups. This is for
1168 * waiting at hith-memory prressure caused by "move".
1171 static bool mem_cgroup_stealed(struct mem_cgroup *mem)
1173 VM_BUG_ON(!rcu_read_lock_held());
1174 return this_cpu_read(mem->stat->count[MEM_CGROUP_ON_MOVE]) > 0;
1177 static bool mem_cgroup_under_move(struct mem_cgroup *mem)
1179 struct mem_cgroup *from;
1180 struct mem_cgroup *to;
1183 * Unlike task_move routines, we access mc.to, mc.from not under
1184 * mutual exclusion by cgroup_mutex. Here, we take spinlock instead.
1186 spin_lock(&mc.lock);
1191 if (from == mem || to == mem
1192 || (mem->use_hierarchy && css_is_ancestor(&from->css, &mem->css))
1193 || (mem->use_hierarchy && css_is_ancestor(&to->css, &mem->css)))
1196 spin_unlock(&mc.lock);
1200 static bool mem_cgroup_wait_acct_move(struct mem_cgroup *mem)
1202 if (mc.moving_task && current != mc.moving_task) {
1203 if (mem_cgroup_under_move(mem)) {
1205 prepare_to_wait(&mc.waitq, &wait, TASK_INTERRUPTIBLE);
1206 /* moving charge context might have finished. */
1209 finish_wait(&mc.waitq, &wait);
1217 * mem_cgroup_print_oom_info: Called from OOM with tasklist_lock held in read mode.
1218 * @memcg: The memory cgroup that went over limit
1219 * @p: Task that is going to be killed
1221 * NOTE: @memcg and @p's mem_cgroup can be different when hierarchy is
1224 void mem_cgroup_print_oom_info(struct mem_cgroup *memcg, struct task_struct *p)
1226 struct cgroup *task_cgrp;
1227 struct cgroup *mem_cgrp;
1229 * Need a buffer in BSS, can't rely on allocations. The code relies
1230 * on the assumption that OOM is serialized for memory controller.
1231 * If this assumption is broken, revisit this code.
1233 static char memcg_name[PATH_MAX];
1242 mem_cgrp = memcg->css.cgroup;
1243 task_cgrp = task_cgroup(p, mem_cgroup_subsys_id);
1245 ret = cgroup_path(task_cgrp, memcg_name, PATH_MAX);
1248 * Unfortunately, we are unable to convert to a useful name
1249 * But we'll still print out the usage information
1256 printk(KERN_INFO "Task in %s killed", memcg_name);
1259 ret = cgroup_path(mem_cgrp, memcg_name, PATH_MAX);
1267 * Continues from above, so we don't need an KERN_ level
1269 printk(KERN_CONT " as a result of limit of %s\n", memcg_name);
1272 printk(KERN_INFO "memory: usage %llukB, limit %llukB, failcnt %llu\n",
1273 res_counter_read_u64(&memcg->res, RES_USAGE) >> 10,
1274 res_counter_read_u64(&memcg->res, RES_LIMIT) >> 10,
1275 res_counter_read_u64(&memcg->res, RES_FAILCNT));
1276 printk(KERN_INFO "memory+swap: usage %llukB, limit %llukB, "
1278 res_counter_read_u64(&memcg->memsw, RES_USAGE) >> 10,
1279 res_counter_read_u64(&memcg->memsw, RES_LIMIT) >> 10,
1280 res_counter_read_u64(&memcg->memsw, RES_FAILCNT));
1284 * This function returns the number of memcg under hierarchy tree. Returns
1285 * 1(self count) if no children.
1287 static int mem_cgroup_count_children(struct mem_cgroup *mem)
1290 struct mem_cgroup *iter;
1292 for_each_mem_cgroup_tree(iter, mem)
1298 * Return the memory (and swap, if configured) limit for a memcg.
1300 u64 mem_cgroup_get_limit(struct mem_cgroup *memcg)
1305 limit = res_counter_read_u64(&memcg->res, RES_LIMIT);
1306 limit += total_swap_pages << PAGE_SHIFT;
1308 memsw = res_counter_read_u64(&memcg->memsw, RES_LIMIT);
1310 * If memsw is finite and limits the amount of swap space available
1311 * to this memcg, return that limit.
1313 return min(limit, memsw);
1317 * Visit the first child (need not be the first child as per the ordering
1318 * of the cgroup list, since we track last_scanned_child) of @mem and use
1319 * that to reclaim free pages from.
1321 static struct mem_cgroup *
1322 mem_cgroup_select_victim(struct mem_cgroup *root_mem)
1324 struct mem_cgroup *ret = NULL;
1325 struct cgroup_subsys_state *css;
1328 if (!root_mem->use_hierarchy) {
1329 css_get(&root_mem->css);
1335 nextid = root_mem->last_scanned_child + 1;
1336 css = css_get_next(&mem_cgroup_subsys, nextid, &root_mem->css,
1338 if (css && css_tryget(css))
1339 ret = container_of(css, struct mem_cgroup, css);
1342 /* Updates scanning parameter */
1343 spin_lock(&root_mem->reclaim_param_lock);
1345 /* this means start scan from ID:1 */
1346 root_mem->last_scanned_child = 0;
1348 root_mem->last_scanned_child = found;
1349 spin_unlock(&root_mem->reclaim_param_lock);
1356 * Scan the hierarchy if needed to reclaim memory. We remember the last child
1357 * we reclaimed from, so that we don't end up penalizing one child extensively
1358 * based on its position in the children list.
1360 * root_mem is the original ancestor that we've been reclaim from.
1362 * We give up and return to the caller when we visit root_mem twice.
1363 * (other groups can be removed while we're walking....)
1365 * If shrink==true, for avoiding to free too much, this returns immedieately.
1367 static int mem_cgroup_hierarchical_reclaim(struct mem_cgroup *root_mem,
1370 unsigned long reclaim_options)
1372 struct mem_cgroup *victim;
1375 bool noswap = reclaim_options & MEM_CGROUP_RECLAIM_NOSWAP;
1376 bool shrink = reclaim_options & MEM_CGROUP_RECLAIM_SHRINK;
1377 bool check_soft = reclaim_options & MEM_CGROUP_RECLAIM_SOFT;
1378 unsigned long excess = mem_cgroup_get_excess(root_mem);
1380 /* If memsw_is_minimum==1, swap-out is of-no-use. */
1381 if (root_mem->memsw_is_minimum)
1385 victim = mem_cgroup_select_victim(root_mem);
1386 if (victim == root_mem) {
1389 drain_all_stock_async();
1392 * If we have not been able to reclaim
1393 * anything, it might because there are
1394 * no reclaimable pages under this hierarchy
1396 if (!check_soft || !total) {
1397 css_put(&victim->css);
1401 * We want to do more targetted reclaim.
1402 * excess >> 2 is not to excessive so as to
1403 * reclaim too much, nor too less that we keep
1404 * coming back to reclaim from this cgroup
1406 if (total >= (excess >> 2) ||
1407 (loop > MEM_CGROUP_MAX_RECLAIM_LOOPS)) {
1408 css_put(&victim->css);
1413 if (!mem_cgroup_local_usage(victim)) {
1414 /* this cgroup's local usage == 0 */
1415 css_put(&victim->css);
1418 /* we use swappiness of local cgroup */
1420 ret = mem_cgroup_shrink_node_zone(victim, gfp_mask,
1421 noswap, get_swappiness(victim), zone);
1423 ret = try_to_free_mem_cgroup_pages(victim, gfp_mask,
1424 noswap, get_swappiness(victim));
1425 css_put(&victim->css);
1427 * At shrinking usage, we can't check we should stop here or
1428 * reclaim more. It's depends on callers. last_scanned_child
1429 * will work enough for keeping fairness under tree.
1435 if (res_counter_check_under_soft_limit(&root_mem->res))
1437 } else if (mem_cgroup_check_under_limit(root_mem))
1444 * Check OOM-Killer is already running under our hierarchy.
1445 * If someone is running, return false.
1447 static bool mem_cgroup_oom_lock(struct mem_cgroup *mem)
1449 int x, lock_count = 0;
1450 struct mem_cgroup *iter;
1452 for_each_mem_cgroup_tree(iter, mem) {
1453 x = atomic_inc_return(&iter->oom_lock);
1454 lock_count = max(x, lock_count);
1457 if (lock_count == 1)
1462 static int mem_cgroup_oom_unlock(struct mem_cgroup *mem)
1464 struct mem_cgroup *iter;
1467 * When a new child is created while the hierarchy is under oom,
1468 * mem_cgroup_oom_lock() may not be called. We have to use
1469 * atomic_add_unless() here.
1471 for_each_mem_cgroup_tree(iter, mem)
1472 atomic_add_unless(&iter->oom_lock, -1, 0);
1477 static DEFINE_MUTEX(memcg_oom_mutex);
1478 static DECLARE_WAIT_QUEUE_HEAD(memcg_oom_waitq);
1480 struct oom_wait_info {
1481 struct mem_cgroup *mem;
1485 static int memcg_oom_wake_function(wait_queue_t *wait,
1486 unsigned mode, int sync, void *arg)
1488 struct mem_cgroup *wake_mem = (struct mem_cgroup *)arg;
1489 struct oom_wait_info *oom_wait_info;
1491 oom_wait_info = container_of(wait, struct oom_wait_info, wait);
1493 if (oom_wait_info->mem == wake_mem)
1495 /* if no hierarchy, no match */
1496 if (!oom_wait_info->mem->use_hierarchy || !wake_mem->use_hierarchy)
1499 * Both of oom_wait_info->mem and wake_mem are stable under us.
1500 * Then we can use css_is_ancestor without taking care of RCU.
1502 if (!css_is_ancestor(&oom_wait_info->mem->css, &wake_mem->css) &&
1503 !css_is_ancestor(&wake_mem->css, &oom_wait_info->mem->css))
1507 return autoremove_wake_function(wait, mode, sync, arg);
1510 static void memcg_wakeup_oom(struct mem_cgroup *mem)
1512 /* for filtering, pass "mem" as argument. */
1513 __wake_up(&memcg_oom_waitq, TASK_NORMAL, 0, mem);
1516 static void memcg_oom_recover(struct mem_cgroup *mem)
1518 if (mem && atomic_read(&mem->oom_lock))
1519 memcg_wakeup_oom(mem);
1523 * try to call OOM killer. returns false if we should exit memory-reclaim loop.
1525 bool mem_cgroup_handle_oom(struct mem_cgroup *mem, gfp_t mask)
1527 struct oom_wait_info owait;
1528 bool locked, need_to_kill;
1531 owait.wait.flags = 0;
1532 owait.wait.func = memcg_oom_wake_function;
1533 owait.wait.private = current;
1534 INIT_LIST_HEAD(&owait.wait.task_list);
1535 need_to_kill = true;
1536 /* At first, try to OOM lock hierarchy under mem.*/
1537 mutex_lock(&memcg_oom_mutex);
1538 locked = mem_cgroup_oom_lock(mem);
1540 * Even if signal_pending(), we can't quit charge() loop without
1541 * accounting. So, UNINTERRUPTIBLE is appropriate. But SIGKILL
1542 * under OOM is always welcomed, use TASK_KILLABLE here.
1544 prepare_to_wait(&memcg_oom_waitq, &owait.wait, TASK_KILLABLE);
1545 if (!locked || mem->oom_kill_disable)
1546 need_to_kill = false;
1548 mem_cgroup_oom_notify(mem);
1549 mutex_unlock(&memcg_oom_mutex);
1552 finish_wait(&memcg_oom_waitq, &owait.wait);
1553 mem_cgroup_out_of_memory(mem, mask);
1556 finish_wait(&memcg_oom_waitq, &owait.wait);
1558 mutex_lock(&memcg_oom_mutex);
1559 mem_cgroup_oom_unlock(mem);
1560 memcg_wakeup_oom(mem);
1561 mutex_unlock(&memcg_oom_mutex);
1563 if (test_thread_flag(TIF_MEMDIE) || fatal_signal_pending(current))
1565 /* Give chance to dying process */
1566 schedule_timeout(1);
1571 * Currently used to update mapped file statistics, but the routine can be
1572 * generalized to update other statistics as well.
1574 * Notes: Race condition
1576 * We usually use page_cgroup_lock() for accessing page_cgroup member but
1577 * it tends to be costly. But considering some conditions, we doesn't need
1578 * to do so _always_.
1580 * Considering "charge", lock_page_cgroup() is not required because all
1581 * file-stat operations happen after a page is attached to radix-tree. There
1582 * are no race with "charge".
1584 * Considering "uncharge", we know that memcg doesn't clear pc->mem_cgroup
1585 * at "uncharge" intentionally. So, we always see valid pc->mem_cgroup even
1586 * if there are race with "uncharge". Statistics itself is properly handled
1589 * Considering "move", this is an only case we see a race. To make the race
1590 * small, we check MEM_CGROUP_ON_MOVE percpu value and detect there are
1591 * possibility of race condition. If there is, we take a lock.
1594 void mem_cgroup_update_page_stat(struct page *page,
1595 enum mem_cgroup_page_stat_item idx, int val)
1597 struct mem_cgroup *mem;
1598 struct page_cgroup *pc = lookup_page_cgroup(page);
1599 bool need_unlock = false;
1600 unsigned long uninitialized_var(flags);
1606 mem = pc->mem_cgroup;
1607 if (unlikely(!mem || !PageCgroupUsed(pc)))
1609 /* pc->mem_cgroup is unstable ? */
1610 if (unlikely(mem_cgroup_stealed(mem)) || PageTransHuge(page)) {
1611 /* take a lock against to access pc->mem_cgroup */
1612 move_lock_page_cgroup(pc, &flags);
1614 mem = pc->mem_cgroup;
1615 if (!mem || !PageCgroupUsed(pc))
1620 case MEMCG_NR_FILE_MAPPED:
1622 SetPageCgroupFileMapped(pc);
1623 else if (!page_mapped(page))
1624 ClearPageCgroupFileMapped(pc);
1625 idx = MEM_CGROUP_STAT_FILE_MAPPED;
1631 this_cpu_add(mem->stat->count[idx], val);
1634 if (unlikely(need_unlock))
1635 move_unlock_page_cgroup(pc, &flags);
1639 EXPORT_SYMBOL(mem_cgroup_update_page_stat);
1642 * size of first charge trial. "32" comes from vmscan.c's magic value.
1643 * TODO: maybe necessary to use big numbers in big irons.
1645 #define CHARGE_SIZE (32 * PAGE_SIZE)
1646 struct memcg_stock_pcp {
1647 struct mem_cgroup *cached; /* this never be root cgroup */
1649 struct work_struct work;
1651 static DEFINE_PER_CPU(struct memcg_stock_pcp, memcg_stock);
1652 static atomic_t memcg_drain_count;
1655 * Try to consume stocked charge on this cpu. If success, PAGE_SIZE is consumed
1656 * from local stock and true is returned. If the stock is 0 or charges from a
1657 * cgroup which is not current target, returns false. This stock will be
1660 static bool consume_stock(struct mem_cgroup *mem)
1662 struct memcg_stock_pcp *stock;
1665 stock = &get_cpu_var(memcg_stock);
1666 if (mem == stock->cached && stock->charge)
1667 stock->charge -= PAGE_SIZE;
1668 else /* need to call res_counter_charge */
1670 put_cpu_var(memcg_stock);
1675 * Returns stocks cached in percpu to res_counter and reset cached information.
1677 static void drain_stock(struct memcg_stock_pcp *stock)
1679 struct mem_cgroup *old = stock->cached;
1681 if (stock->charge) {
1682 res_counter_uncharge(&old->res, stock->charge);
1683 if (do_swap_account)
1684 res_counter_uncharge(&old->memsw, stock->charge);
1686 stock->cached = NULL;
1691 * This must be called under preempt disabled or must be called by
1692 * a thread which is pinned to local cpu.
1694 static void drain_local_stock(struct work_struct *dummy)
1696 struct memcg_stock_pcp *stock = &__get_cpu_var(memcg_stock);
1701 * Cache charges(val) which is from res_counter, to local per_cpu area.
1702 * This will be consumed by consume_stock() function, later.
1704 static void refill_stock(struct mem_cgroup *mem, int val)
1706 struct memcg_stock_pcp *stock = &get_cpu_var(memcg_stock);
1708 if (stock->cached != mem) { /* reset if necessary */
1710 stock->cached = mem;
1712 stock->charge += val;
1713 put_cpu_var(memcg_stock);
1717 * Tries to drain stocked charges in other cpus. This function is asynchronous
1718 * and just put a work per cpu for draining localy on each cpu. Caller can
1719 * expects some charges will be back to res_counter later but cannot wait for
1722 static void drain_all_stock_async(void)
1725 /* This function is for scheduling "drain" in asynchronous way.
1726 * The result of "drain" is not directly handled by callers. Then,
1727 * if someone is calling drain, we don't have to call drain more.
1728 * Anyway, WORK_STRUCT_PENDING check in queue_work_on() will catch if
1729 * there is a race. We just do loose check here.
1731 if (atomic_read(&memcg_drain_count))
1733 /* Notify other cpus that system-wide "drain" is running */
1734 atomic_inc(&memcg_drain_count);
1736 for_each_online_cpu(cpu) {
1737 struct memcg_stock_pcp *stock = &per_cpu(memcg_stock, cpu);
1738 schedule_work_on(cpu, &stock->work);
1741 atomic_dec(&memcg_drain_count);
1742 /* We don't wait for flush_work */
1745 /* This is a synchronous drain interface. */
1746 static void drain_all_stock_sync(void)
1748 /* called when force_empty is called */
1749 atomic_inc(&memcg_drain_count);
1750 schedule_on_each_cpu(drain_local_stock);
1751 atomic_dec(&memcg_drain_count);
1755 * This function drains percpu counter value from DEAD cpu and
1756 * move it to local cpu. Note that this function can be preempted.
1758 static void mem_cgroup_drain_pcp_counter(struct mem_cgroup *mem, int cpu)
1762 spin_lock(&mem->pcp_counter_lock);
1763 for (i = 0; i < MEM_CGROUP_STAT_DATA; i++) {
1764 s64 x = per_cpu(mem->stat->count[i], cpu);
1766 per_cpu(mem->stat->count[i], cpu) = 0;
1767 mem->nocpu_base.count[i] += x;
1769 /* need to clear ON_MOVE value, works as a kind of lock. */
1770 per_cpu(mem->stat->count[MEM_CGROUP_ON_MOVE], cpu) = 0;
1771 spin_unlock(&mem->pcp_counter_lock);
1774 static void synchronize_mem_cgroup_on_move(struct mem_cgroup *mem, int cpu)
1776 int idx = MEM_CGROUP_ON_MOVE;
1778 spin_lock(&mem->pcp_counter_lock);
1779 per_cpu(mem->stat->count[idx], cpu) = mem->nocpu_base.count[idx];
1780 spin_unlock(&mem->pcp_counter_lock);
1783 static int __cpuinit memcg_cpu_hotplug_callback(struct notifier_block *nb,
1784 unsigned long action,
1787 int cpu = (unsigned long)hcpu;
1788 struct memcg_stock_pcp *stock;
1789 struct mem_cgroup *iter;
1791 if ((action == CPU_ONLINE)) {
1792 for_each_mem_cgroup_all(iter)
1793 synchronize_mem_cgroup_on_move(iter, cpu);
1797 if ((action != CPU_DEAD) || action != CPU_DEAD_FROZEN)
1800 for_each_mem_cgroup_all(iter)
1801 mem_cgroup_drain_pcp_counter(iter, cpu);
1803 stock = &per_cpu(memcg_stock, cpu);
1809 /* See __mem_cgroup_try_charge() for details */
1811 CHARGE_OK, /* success */
1812 CHARGE_RETRY, /* need to retry but retry is not bad */
1813 CHARGE_NOMEM, /* we can't do more. return -ENOMEM */
1814 CHARGE_WOULDBLOCK, /* GFP_WAIT wasn't set and no enough res. */
1815 CHARGE_OOM_DIE, /* the current is killed because of OOM */
1818 static int __mem_cgroup_do_charge(struct mem_cgroup *mem, gfp_t gfp_mask,
1819 int csize, bool oom_check)
1821 struct mem_cgroup *mem_over_limit;
1822 struct res_counter *fail_res;
1823 unsigned long flags = 0;
1826 ret = res_counter_charge(&mem->res, csize, &fail_res);
1829 if (!do_swap_account)
1831 ret = res_counter_charge(&mem->memsw, csize, &fail_res);
1835 mem_over_limit = mem_cgroup_from_res_counter(fail_res, memsw);
1836 flags |= MEM_CGROUP_RECLAIM_NOSWAP;
1838 mem_over_limit = mem_cgroup_from_res_counter(fail_res, res);
1840 if (csize > PAGE_SIZE) /* change csize and retry */
1841 return CHARGE_RETRY;
1843 if (!(gfp_mask & __GFP_WAIT))
1844 return CHARGE_WOULDBLOCK;
1846 ret = mem_cgroup_hierarchical_reclaim(mem_over_limit, NULL,
1849 * try_to_free_mem_cgroup_pages() might not give us a full
1850 * picture of reclaim. Some pages are reclaimed and might be
1851 * moved to swap cache or just unmapped from the cgroup.
1852 * Check the limit again to see if the reclaim reduced the
1853 * current usage of the cgroup before giving up
1855 if (ret || mem_cgroup_check_under_limit(mem_over_limit))
1856 return CHARGE_RETRY;
1859 * At task move, charge accounts can be doubly counted. So, it's
1860 * better to wait until the end of task_move if something is going on.
1862 if (mem_cgroup_wait_acct_move(mem_over_limit))
1863 return CHARGE_RETRY;
1865 /* If we don't need to call oom-killer at el, return immediately */
1867 return CHARGE_NOMEM;
1869 if (!mem_cgroup_handle_oom(mem_over_limit, gfp_mask))
1870 return CHARGE_OOM_DIE;
1872 return CHARGE_RETRY;
1876 * Unlike exported interface, "oom" parameter is added. if oom==true,
1877 * oom-killer can be invoked.
1879 static int __mem_cgroup_try_charge(struct mm_struct *mm,
1881 struct mem_cgroup **memcg, bool oom,
1884 int nr_oom_retries = MEM_CGROUP_RECLAIM_RETRIES;
1885 struct mem_cgroup *mem = NULL;
1887 int csize = max(CHARGE_SIZE, (unsigned long) page_size);
1890 * Unlike gloval-vm's OOM-kill, we're not in memory shortage
1891 * in system level. So, allow to go ahead dying process in addition to
1894 if (unlikely(test_thread_flag(TIF_MEMDIE)
1895 || fatal_signal_pending(current)))
1899 * We always charge the cgroup the mm_struct belongs to.
1900 * The mm_struct's mem_cgroup changes on task migration if the
1901 * thread group leader migrates. It's possible that mm is not
1902 * set, if so charge the init_mm (happens for pagecache usage).
1907 if (*memcg) { /* css should be a valid one */
1909 VM_BUG_ON(css_is_removed(&mem->css));
1910 if (mem_cgroup_is_root(mem))
1912 if (page_size == PAGE_SIZE && consume_stock(mem))
1916 struct task_struct *p;
1919 p = rcu_dereference(mm->owner);
1921 * Because we don't have task_lock(), "p" can exit.
1922 * In that case, "mem" can point to root or p can be NULL with
1923 * race with swapoff. Then, we have small risk of mis-accouning.
1924 * But such kind of mis-account by race always happens because
1925 * we don't have cgroup_mutex(). It's overkill and we allo that
1927 * (*) swapoff at el will charge against mm-struct not against
1928 * task-struct. So, mm->owner can be NULL.
1930 mem = mem_cgroup_from_task(p);
1931 if (!mem || mem_cgroup_is_root(mem)) {
1935 if (page_size == PAGE_SIZE && consume_stock(mem)) {
1937 * It seems dagerous to access memcg without css_get().
1938 * But considering how consume_stok works, it's not
1939 * necessary. If consume_stock success, some charges
1940 * from this memcg are cached on this cpu. So, we
1941 * don't need to call css_get()/css_tryget() before
1942 * calling consume_stock().
1947 /* after here, we may be blocked. we need to get refcnt */
1948 if (!css_tryget(&mem->css)) {
1958 /* If killed, bypass charge */
1959 if (fatal_signal_pending(current)) {
1965 if (oom && !nr_oom_retries) {
1967 nr_oom_retries = MEM_CGROUP_RECLAIM_RETRIES;
1970 ret = __mem_cgroup_do_charge(mem, gfp_mask, csize, oom_check);
1975 case CHARGE_RETRY: /* not in OOM situation but retry */
1980 case CHARGE_WOULDBLOCK: /* !__GFP_WAIT */
1983 case CHARGE_NOMEM: /* OOM routine works */
1988 /* If oom, we never return -ENOMEM */
1991 case CHARGE_OOM_DIE: /* Killed by OOM Killer */
1995 } while (ret != CHARGE_OK);
1997 if (csize > page_size)
1998 refill_stock(mem, csize - page_size);
2012 * Somemtimes we have to undo a charge we got by try_charge().
2013 * This function is for that and do uncharge, put css's refcnt.
2014 * gotten by try_charge().
2016 static void __mem_cgroup_cancel_charge(struct mem_cgroup *mem,
2017 unsigned long count)
2019 if (!mem_cgroup_is_root(mem)) {
2020 res_counter_uncharge(&mem->res, PAGE_SIZE * count);
2021 if (do_swap_account)
2022 res_counter_uncharge(&mem->memsw, PAGE_SIZE * count);
2026 static void mem_cgroup_cancel_charge(struct mem_cgroup *mem,
2029 __mem_cgroup_cancel_charge(mem, page_size >> PAGE_SHIFT);
2033 * A helper function to get mem_cgroup from ID. must be called under
2034 * rcu_read_lock(). The caller must check css_is_removed() or some if
2035 * it's concern. (dropping refcnt from swap can be called against removed
2038 static struct mem_cgroup *mem_cgroup_lookup(unsigned short id)
2040 struct cgroup_subsys_state *css;
2042 /* ID 0 is unused ID */
2045 css = css_lookup(&mem_cgroup_subsys, id);
2048 return container_of(css, struct mem_cgroup, css);
2051 struct mem_cgroup *try_get_mem_cgroup_from_page(struct page *page)
2053 struct mem_cgroup *mem = NULL;
2054 struct page_cgroup *pc;
2058 VM_BUG_ON(!PageLocked(page));
2060 pc = lookup_page_cgroup(page);
2061 lock_page_cgroup(pc);
2062 if (PageCgroupUsed(pc)) {
2063 mem = pc->mem_cgroup;
2064 if (mem && !css_tryget(&mem->css))
2066 } else if (PageSwapCache(page)) {
2067 ent.val = page_private(page);
2068 id = lookup_swap_cgroup(ent);
2070 mem = mem_cgroup_lookup(id);
2071 if (mem && !css_tryget(&mem->css))
2075 unlock_page_cgroup(pc);
2079 static void __mem_cgroup_commit_charge(struct mem_cgroup *mem,
2080 struct page_cgroup *pc,
2081 enum charge_type ctype,
2084 int nr_pages = page_size >> PAGE_SHIFT;
2086 /* try_charge() can return NULL to *memcg, taking care of it. */
2090 lock_page_cgroup(pc);
2091 if (unlikely(PageCgroupUsed(pc))) {
2092 unlock_page_cgroup(pc);
2093 mem_cgroup_cancel_charge(mem, page_size);
2097 * we don't need page_cgroup_lock about tail pages, becase they are not
2098 * accessed by any other context at this point.
2100 pc->mem_cgroup = mem;
2102 * We access a page_cgroup asynchronously without lock_page_cgroup().
2103 * Especially when a page_cgroup is taken from a page, pc->mem_cgroup
2104 * is accessed after testing USED bit. To make pc->mem_cgroup visible
2105 * before USED bit, we need memory barrier here.
2106 * See mem_cgroup_add_lru_list(), etc.
2110 case MEM_CGROUP_CHARGE_TYPE_CACHE:
2111 case MEM_CGROUP_CHARGE_TYPE_SHMEM:
2112 SetPageCgroupCache(pc);
2113 SetPageCgroupUsed(pc);
2115 case MEM_CGROUP_CHARGE_TYPE_MAPPED:
2116 ClearPageCgroupCache(pc);
2117 SetPageCgroupUsed(pc);
2123 mem_cgroup_charge_statistics(mem, PageCgroupCache(pc), nr_pages);
2124 unlock_page_cgroup(pc);
2126 * "charge_statistics" updated event counter. Then, check it.
2127 * Insert ancestor (and ancestor's ancestors), to softlimit RB-tree.
2128 * if they exceeds softlimit.
2130 memcg_check_events(mem, pc->page);
2133 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
2135 #define PCGF_NOCOPY_AT_SPLIT ((1 << PCG_LOCK) | (1 << PCG_MOVE_LOCK) |\
2136 (1 << PCG_ACCT_LRU) | (1 << PCG_MIGRATION))
2138 * Because tail pages are not marked as "used", set it. We're under
2139 * zone->lru_lock, 'splitting on pmd' and compund_lock.
2141 void mem_cgroup_split_huge_fixup(struct page *head, struct page *tail)
2143 struct page_cgroup *head_pc = lookup_page_cgroup(head);
2144 struct page_cgroup *tail_pc = lookup_page_cgroup(tail);
2145 unsigned long flags;
2148 * We have no races with charge/uncharge but will have races with
2149 * page state accounting.
2151 move_lock_page_cgroup(head_pc, &flags);
2153 tail_pc->mem_cgroup = head_pc->mem_cgroup;
2154 smp_wmb(); /* see __commit_charge() */
2155 if (PageCgroupAcctLRU(head_pc)) {
2157 struct mem_cgroup_per_zone *mz;
2160 * LRU flags cannot be copied because we need to add tail
2161 *.page to LRU by generic call and our hook will be called.
2162 * We hold lru_lock, then, reduce counter directly.
2164 lru = page_lru(head);
2165 mz = page_cgroup_zoneinfo(head_pc);
2166 MEM_CGROUP_ZSTAT(mz, lru) -= 1;
2168 tail_pc->flags = head_pc->flags & ~PCGF_NOCOPY_AT_SPLIT;
2169 move_unlock_page_cgroup(head_pc, &flags);
2174 * __mem_cgroup_move_account - move account of the page
2175 * @pc: page_cgroup of the page.
2176 * @from: mem_cgroup which the page is moved from.
2177 * @to: mem_cgroup which the page is moved to. @from != @to.
2178 * @uncharge: whether we should call uncharge and css_put against @from.
2180 * The caller must confirm following.
2181 * - page is not on LRU (isolate_page() is useful.)
2182 * - the pc is locked, used, and ->mem_cgroup points to @from.
2184 * This function doesn't do "charge" nor css_get to new cgroup. It should be
2185 * done by a caller(__mem_cgroup_try_charge would be usefull). If @uncharge is
2186 * true, this function does "uncharge" from old cgroup, but it doesn't if
2187 * @uncharge is false, so a caller should do "uncharge".
2190 static void __mem_cgroup_move_account(struct page_cgroup *pc,
2191 struct mem_cgroup *from, struct mem_cgroup *to, bool uncharge,
2194 int nr_pages = charge_size >> PAGE_SHIFT;
2196 VM_BUG_ON(from == to);
2197 VM_BUG_ON(PageLRU(pc->page));
2198 VM_BUG_ON(!page_is_cgroup_locked(pc));
2199 VM_BUG_ON(!PageCgroupUsed(pc));
2200 VM_BUG_ON(pc->mem_cgroup != from);
2202 if (PageCgroupFileMapped(pc)) {
2203 /* Update mapped_file data for mem_cgroup */
2205 __this_cpu_dec(from->stat->count[MEM_CGROUP_STAT_FILE_MAPPED]);
2206 __this_cpu_inc(to->stat->count[MEM_CGROUP_STAT_FILE_MAPPED]);
2209 mem_cgroup_charge_statistics(from, PageCgroupCache(pc), -nr_pages);
2211 /* This is not "cancel", but cancel_charge does all we need. */
2212 mem_cgroup_cancel_charge(from, charge_size);
2214 /* caller should have done css_get */
2215 pc->mem_cgroup = to;
2216 mem_cgroup_charge_statistics(to, PageCgroupCache(pc), nr_pages);
2218 * We charges against "to" which may not have any tasks. Then, "to"
2219 * can be under rmdir(). But in current implementation, caller of
2220 * this function is just force_empty() and move charge, so it's
2221 * garanteed that "to" is never removed. So, we don't check rmdir
2227 * check whether the @pc is valid for moving account and call
2228 * __mem_cgroup_move_account()
2230 static int mem_cgroup_move_account(struct page_cgroup *pc,
2231 struct mem_cgroup *from, struct mem_cgroup *to,
2232 bool uncharge, int charge_size)
2235 unsigned long flags;
2237 if ((charge_size > PAGE_SIZE) && !PageTransHuge(pc->page))
2240 lock_page_cgroup(pc);
2241 if (PageCgroupUsed(pc) && pc->mem_cgroup == from) {
2242 move_lock_page_cgroup(pc, &flags);
2243 __mem_cgroup_move_account(pc, from, to, uncharge, charge_size);
2244 move_unlock_page_cgroup(pc, &flags);
2247 unlock_page_cgroup(pc);
2251 memcg_check_events(to, pc->page);
2252 memcg_check_events(from, pc->page);
2257 * move charges to its parent.
2260 static int mem_cgroup_move_parent(struct page_cgroup *pc,
2261 struct mem_cgroup *child,
2264 struct page *page = pc->page;
2265 struct cgroup *cg = child->css.cgroup;
2266 struct cgroup *pcg = cg->parent;
2267 struct mem_cgroup *parent;
2268 int charge = PAGE_SIZE;
2269 unsigned long flags;
2277 if (!get_page_unless_zero(page))
2279 if (isolate_lru_page(page))
2281 /* The page is isolated from LRU and we have no race with splitting */
2282 charge = PAGE_SIZE << compound_order(page);
2284 parent = mem_cgroup_from_cont(pcg);
2285 ret = __mem_cgroup_try_charge(NULL, gfp_mask, &parent, false, charge);
2289 if (charge > PAGE_SIZE)
2290 flags = compound_lock_irqsave(page);
2292 ret = mem_cgroup_move_account(pc, child, parent, true, charge);
2294 mem_cgroup_cancel_charge(parent, charge);
2296 if (charge > PAGE_SIZE)
2297 compound_unlock_irqrestore(page, flags);
2298 putback_lru_page(page);
2306 * Charge the memory controller for page usage.
2308 * 0 if the charge was successful
2309 * < 0 if the cgroup is over its limit
2311 static int mem_cgroup_charge_common(struct page *page, struct mm_struct *mm,
2312 gfp_t gfp_mask, enum charge_type ctype)
2314 struct mem_cgroup *mem = NULL;
2315 struct page_cgroup *pc;
2317 int page_size = PAGE_SIZE;
2319 if (PageTransHuge(page)) {
2320 page_size <<= compound_order(page);
2321 VM_BUG_ON(!PageTransHuge(page));
2324 pc = lookup_page_cgroup(page);
2325 /* can happen at boot */
2330 ret = __mem_cgroup_try_charge(mm, gfp_mask, &mem, true, page_size);
2334 __mem_cgroup_commit_charge(mem, pc, ctype, page_size);
2338 int mem_cgroup_newpage_charge(struct page *page,
2339 struct mm_struct *mm, gfp_t gfp_mask)
2341 if (mem_cgroup_disabled())
2344 * If already mapped, we don't have to account.
2345 * If page cache, page->mapping has address_space.
2346 * But page->mapping may have out-of-use anon_vma pointer,
2347 * detecit it by PageAnon() check. newly-mapped-anon's page->mapping
2350 if (page_mapped(page) || (page->mapping && !PageAnon(page)))
2354 return mem_cgroup_charge_common(page, mm, gfp_mask,
2355 MEM_CGROUP_CHARGE_TYPE_MAPPED);
2359 __mem_cgroup_commit_charge_swapin(struct page *page, struct mem_cgroup *ptr,
2360 enum charge_type ctype);
2362 int mem_cgroup_cache_charge(struct page *page, struct mm_struct *mm,
2367 if (mem_cgroup_disabled())
2369 if (PageCompound(page))
2372 * Corner case handling. This is called from add_to_page_cache()
2373 * in usual. But some FS (shmem) precharges this page before calling it
2374 * and call add_to_page_cache() with GFP_NOWAIT.
2376 * For GFP_NOWAIT case, the page may be pre-charged before calling
2377 * add_to_page_cache(). (See shmem.c) check it here and avoid to call
2378 * charge twice. (It works but has to pay a bit larger cost.)
2379 * And when the page is SwapCache, it should take swap information
2380 * into account. This is under lock_page() now.
2382 if (!(gfp_mask & __GFP_WAIT)) {
2383 struct page_cgroup *pc;
2385 pc = lookup_page_cgroup(page);
2388 lock_page_cgroup(pc);
2389 if (PageCgroupUsed(pc)) {
2390 unlock_page_cgroup(pc);
2393 unlock_page_cgroup(pc);
2399 if (page_is_file_cache(page))
2400 return mem_cgroup_charge_common(page, mm, gfp_mask,
2401 MEM_CGROUP_CHARGE_TYPE_CACHE);
2404 if (PageSwapCache(page)) {
2405 struct mem_cgroup *mem = NULL;
2407 ret = mem_cgroup_try_charge_swapin(mm, page, gfp_mask, &mem);
2409 __mem_cgroup_commit_charge_swapin(page, mem,
2410 MEM_CGROUP_CHARGE_TYPE_SHMEM);
2412 ret = mem_cgroup_charge_common(page, mm, gfp_mask,
2413 MEM_CGROUP_CHARGE_TYPE_SHMEM);
2419 * While swap-in, try_charge -> commit or cancel, the page is locked.
2420 * And when try_charge() successfully returns, one refcnt to memcg without
2421 * struct page_cgroup is acquired. This refcnt will be consumed by
2422 * "commit()" or removed by "cancel()"
2424 int mem_cgroup_try_charge_swapin(struct mm_struct *mm,
2426 gfp_t mask, struct mem_cgroup **ptr)
2428 struct mem_cgroup *mem;
2431 if (mem_cgroup_disabled())
2434 if (!do_swap_account)
2437 * A racing thread's fault, or swapoff, may have already updated
2438 * the pte, and even removed page from swap cache: in those cases
2439 * do_swap_page()'s pte_same() test will fail; but there's also a
2440 * KSM case which does need to charge the page.
2442 if (!PageSwapCache(page))
2444 mem = try_get_mem_cgroup_from_page(page);
2448 ret = __mem_cgroup_try_charge(NULL, mask, ptr, true, PAGE_SIZE);
2454 return __mem_cgroup_try_charge(mm, mask, ptr, true, PAGE_SIZE);
2458 __mem_cgroup_commit_charge_swapin(struct page *page, struct mem_cgroup *ptr,
2459 enum charge_type ctype)
2461 struct page_cgroup *pc;
2463 if (mem_cgroup_disabled())
2467 cgroup_exclude_rmdir(&ptr->css);
2468 pc = lookup_page_cgroup(page);
2469 mem_cgroup_lru_del_before_commit_swapcache(page);
2470 __mem_cgroup_commit_charge(ptr, pc, ctype, PAGE_SIZE);
2471 mem_cgroup_lru_add_after_commit_swapcache(page);
2473 * Now swap is on-memory. This means this page may be
2474 * counted both as mem and swap....double count.
2475 * Fix it by uncharging from memsw. Basically, this SwapCache is stable
2476 * under lock_page(). But in do_swap_page()::memory.c, reuse_swap_page()
2477 * may call delete_from_swap_cache() before reach here.
2479 if (do_swap_account && PageSwapCache(page)) {
2480 swp_entry_t ent = {.val = page_private(page)};
2482 struct mem_cgroup *memcg;
2484 id = swap_cgroup_record(ent, 0);
2486 memcg = mem_cgroup_lookup(id);
2489 * This recorded memcg can be obsolete one. So, avoid
2490 * calling css_tryget
2492 if (!mem_cgroup_is_root(memcg))
2493 res_counter_uncharge(&memcg->memsw, PAGE_SIZE);
2494 mem_cgroup_swap_statistics(memcg, false);
2495 mem_cgroup_put(memcg);
2500 * At swapin, we may charge account against cgroup which has no tasks.
2501 * So, rmdir()->pre_destroy() can be called while we do this charge.
2502 * In that case, we need to call pre_destroy() again. check it here.
2504 cgroup_release_and_wakeup_rmdir(&ptr->css);
2507 void mem_cgroup_commit_charge_swapin(struct page *page, struct mem_cgroup *ptr)
2509 __mem_cgroup_commit_charge_swapin(page, ptr,
2510 MEM_CGROUP_CHARGE_TYPE_MAPPED);
2513 void mem_cgroup_cancel_charge_swapin(struct mem_cgroup *mem)
2515 if (mem_cgroup_disabled())
2519 mem_cgroup_cancel_charge(mem, PAGE_SIZE);
2523 __do_uncharge(struct mem_cgroup *mem, const enum charge_type ctype,
2526 struct memcg_batch_info *batch = NULL;
2527 bool uncharge_memsw = true;
2528 /* If swapout, usage of swap doesn't decrease */
2529 if (!do_swap_account || ctype == MEM_CGROUP_CHARGE_TYPE_SWAPOUT)
2530 uncharge_memsw = false;
2532 batch = ¤t->memcg_batch;
2534 * In usual, we do css_get() when we remember memcg pointer.
2535 * But in this case, we keep res->usage until end of a series of
2536 * uncharges. Then, it's ok to ignore memcg's refcnt.
2541 * do_batch > 0 when unmapping pages or inode invalidate/truncate.
2542 * In those cases, all pages freed continously can be expected to be in
2543 * the same cgroup and we have chance to coalesce uncharges.
2544 * But we do uncharge one by one if this is killed by OOM(TIF_MEMDIE)
2545 * because we want to do uncharge as soon as possible.
2548 if (!batch->do_batch || test_thread_flag(TIF_MEMDIE))
2549 goto direct_uncharge;
2551 if (page_size != PAGE_SIZE)
2552 goto direct_uncharge;
2555 * In typical case, batch->memcg == mem. This means we can
2556 * merge a series of uncharges to an uncharge of res_counter.
2557 * If not, we uncharge res_counter ony by one.
2559 if (batch->memcg != mem)
2560 goto direct_uncharge;
2561 /* remember freed charge and uncharge it later */
2562 batch->bytes += PAGE_SIZE;
2564 batch->memsw_bytes += PAGE_SIZE;
2567 res_counter_uncharge(&mem->res, page_size);
2569 res_counter_uncharge(&mem->memsw, page_size);
2570 if (unlikely(batch->memcg != mem))
2571 memcg_oom_recover(mem);
2576 * uncharge if !page_mapped(page)
2578 static struct mem_cgroup *
2579 __mem_cgroup_uncharge_common(struct page *page, enum charge_type ctype)
2582 struct page_cgroup *pc;
2583 struct mem_cgroup *mem = NULL;
2584 int page_size = PAGE_SIZE;
2586 if (mem_cgroup_disabled())
2589 if (PageSwapCache(page))
2592 if (PageTransHuge(page)) {
2593 page_size <<= compound_order(page);
2594 VM_BUG_ON(!PageTransHuge(page));
2597 count = page_size >> PAGE_SHIFT;
2599 * Check if our page_cgroup is valid
2601 pc = lookup_page_cgroup(page);
2602 if (unlikely(!pc || !PageCgroupUsed(pc)))
2605 lock_page_cgroup(pc);
2607 mem = pc->mem_cgroup;
2609 if (!PageCgroupUsed(pc))
2613 case MEM_CGROUP_CHARGE_TYPE_MAPPED:
2614 case MEM_CGROUP_CHARGE_TYPE_DROP:
2615 /* See mem_cgroup_prepare_migration() */
2616 if (page_mapped(page) || PageCgroupMigration(pc))
2619 case MEM_CGROUP_CHARGE_TYPE_SWAPOUT:
2620 if (!PageAnon(page)) { /* Shared memory */
2621 if (page->mapping && !page_is_file_cache(page))
2623 } else if (page_mapped(page)) /* Anon */
2630 mem_cgroup_charge_statistics(mem, PageCgroupCache(pc), -count);
2632 ClearPageCgroupUsed(pc);
2634 * pc->mem_cgroup is not cleared here. It will be accessed when it's
2635 * freed from LRU. This is safe because uncharged page is expected not
2636 * to be reused (freed soon). Exception is SwapCache, it's handled by
2637 * special functions.
2640 unlock_page_cgroup(pc);
2642 * even after unlock, we have mem->res.usage here and this memcg
2643 * will never be freed.
2645 memcg_check_events(mem, page);
2646 if (do_swap_account && ctype == MEM_CGROUP_CHARGE_TYPE_SWAPOUT) {
2647 mem_cgroup_swap_statistics(mem, true);
2648 mem_cgroup_get(mem);
2650 if (!mem_cgroup_is_root(mem))
2651 __do_uncharge(mem, ctype, page_size);
2656 unlock_page_cgroup(pc);
2660 void mem_cgroup_uncharge_page(struct page *page)
2663 if (page_mapped(page))
2665 if (page->mapping && !PageAnon(page))
2667 __mem_cgroup_uncharge_common(page, MEM_CGROUP_CHARGE_TYPE_MAPPED);
2670 void mem_cgroup_uncharge_cache_page(struct page *page)
2672 VM_BUG_ON(page_mapped(page));
2673 VM_BUG_ON(page->mapping);
2674 __mem_cgroup_uncharge_common(page, MEM_CGROUP_CHARGE_TYPE_CACHE);
2678 * Batch_start/batch_end is called in unmap_page_range/invlidate/trucate.
2679 * In that cases, pages are freed continuously and we can expect pages
2680 * are in the same memcg. All these calls itself limits the number of
2681 * pages freed at once, then uncharge_start/end() is called properly.
2682 * This may be called prural(2) times in a context,
2685 void mem_cgroup_uncharge_start(void)
2687 current->memcg_batch.do_batch++;
2688 /* We can do nest. */
2689 if (current->memcg_batch.do_batch == 1) {
2690 current->memcg_batch.memcg = NULL;
2691 current->memcg_batch.bytes = 0;
2692 current->memcg_batch.memsw_bytes = 0;
2696 void mem_cgroup_uncharge_end(void)
2698 struct memcg_batch_info *batch = ¤t->memcg_batch;
2700 if (!batch->do_batch)
2704 if (batch->do_batch) /* If stacked, do nothing. */
2710 * This "batch->memcg" is valid without any css_get/put etc...
2711 * bacause we hide charges behind us.
2714 res_counter_uncharge(&batch->memcg->res, batch->bytes);
2715 if (batch->memsw_bytes)
2716 res_counter_uncharge(&batch->memcg->memsw, batch->memsw_bytes);
2717 memcg_oom_recover(batch->memcg);
2718 /* forget this pointer (for sanity check) */
2719 batch->memcg = NULL;
2724 * called after __delete_from_swap_cache() and drop "page" account.
2725 * memcg information is recorded to swap_cgroup of "ent"
2728 mem_cgroup_uncharge_swapcache(struct page *page, swp_entry_t ent, bool swapout)
2730 struct mem_cgroup *memcg;
2731 int ctype = MEM_CGROUP_CHARGE_TYPE_SWAPOUT;
2733 if (!swapout) /* this was a swap cache but the swap is unused ! */
2734 ctype = MEM_CGROUP_CHARGE_TYPE_DROP;
2736 memcg = __mem_cgroup_uncharge_common(page, ctype);
2739 * record memcg information, if swapout && memcg != NULL,
2740 * mem_cgroup_get() was called in uncharge().
2742 if (do_swap_account && swapout && memcg)
2743 swap_cgroup_record(ent, css_id(&memcg->css));
2747 #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP
2749 * called from swap_entry_free(). remove record in swap_cgroup and
2750 * uncharge "memsw" account.
2752 void mem_cgroup_uncharge_swap(swp_entry_t ent)
2754 struct mem_cgroup *memcg;
2757 if (!do_swap_account)
2760 id = swap_cgroup_record(ent, 0);
2762 memcg = mem_cgroup_lookup(id);
2765 * We uncharge this because swap is freed.
2766 * This memcg can be obsolete one. We avoid calling css_tryget
2768 if (!mem_cgroup_is_root(memcg))
2769 res_counter_uncharge(&memcg->memsw, PAGE_SIZE);
2770 mem_cgroup_swap_statistics(memcg, false);
2771 mem_cgroup_put(memcg);
2777 * mem_cgroup_move_swap_account - move swap charge and swap_cgroup's record.
2778 * @entry: swap entry to be moved
2779 * @from: mem_cgroup which the entry is moved from
2780 * @to: mem_cgroup which the entry is moved to
2781 * @need_fixup: whether we should fixup res_counters and refcounts.
2783 * It succeeds only when the swap_cgroup's record for this entry is the same
2784 * as the mem_cgroup's id of @from.
2786 * Returns 0 on success, -EINVAL on failure.
2788 * The caller must have charged to @to, IOW, called res_counter_charge() about
2789 * both res and memsw, and called css_get().
2791 static int mem_cgroup_move_swap_account(swp_entry_t entry,
2792 struct mem_cgroup *from, struct mem_cgroup *to, bool need_fixup)
2794 unsigned short old_id, new_id;
2796 old_id = css_id(&from->css);
2797 new_id = css_id(&to->css);
2799 if (swap_cgroup_cmpxchg(entry, old_id, new_id) == old_id) {
2800 mem_cgroup_swap_statistics(from, false);
2801 mem_cgroup_swap_statistics(to, true);
2803 * This function is only called from task migration context now.
2804 * It postpones res_counter and refcount handling till the end
2805 * of task migration(mem_cgroup_clear_mc()) for performance
2806 * improvement. But we cannot postpone mem_cgroup_get(to)
2807 * because if the process that has been moved to @to does
2808 * swap-in, the refcount of @to might be decreased to 0.
2812 if (!mem_cgroup_is_root(from))
2813 res_counter_uncharge(&from->memsw, PAGE_SIZE);
2814 mem_cgroup_put(from);
2816 * we charged both to->res and to->memsw, so we should
2819 if (!mem_cgroup_is_root(to))
2820 res_counter_uncharge(&to->res, PAGE_SIZE);
2827 static inline int mem_cgroup_move_swap_account(swp_entry_t entry,
2828 struct mem_cgroup *from, struct mem_cgroup *to, bool need_fixup)
2835 * Before starting migration, account PAGE_SIZE to mem_cgroup that the old
2838 int mem_cgroup_prepare_migration(struct page *page,
2839 struct page *newpage, struct mem_cgroup **ptr)
2841 struct page_cgroup *pc;
2842 struct mem_cgroup *mem = NULL;
2843 enum charge_type ctype;
2846 VM_BUG_ON(PageTransHuge(page));
2847 if (mem_cgroup_disabled())
2850 pc = lookup_page_cgroup(page);
2851 lock_page_cgroup(pc);
2852 if (PageCgroupUsed(pc)) {
2853 mem = pc->mem_cgroup;
2856 * At migrating an anonymous page, its mapcount goes down
2857 * to 0 and uncharge() will be called. But, even if it's fully
2858 * unmapped, migration may fail and this page has to be
2859 * charged again. We set MIGRATION flag here and delay uncharge
2860 * until end_migration() is called
2862 * Corner Case Thinking
2864 * When the old page was mapped as Anon and it's unmap-and-freed
2865 * while migration was ongoing.
2866 * If unmap finds the old page, uncharge() of it will be delayed
2867 * until end_migration(). If unmap finds a new page, it's
2868 * uncharged when it make mapcount to be 1->0. If unmap code
2869 * finds swap_migration_entry, the new page will not be mapped
2870 * and end_migration() will find it(mapcount==0).
2873 * When the old page was mapped but migraion fails, the kernel
2874 * remaps it. A charge for it is kept by MIGRATION flag even
2875 * if mapcount goes down to 0. We can do remap successfully
2876 * without charging it again.
2879 * The "old" page is under lock_page() until the end of
2880 * migration, so, the old page itself will not be swapped-out.
2881 * If the new page is swapped out before end_migraton, our
2882 * hook to usual swap-out path will catch the event.
2885 SetPageCgroupMigration(pc);
2887 unlock_page_cgroup(pc);
2889 * If the page is not charged at this point,
2896 ret = __mem_cgroup_try_charge(NULL, GFP_KERNEL, ptr, false, PAGE_SIZE);
2897 css_put(&mem->css);/* drop extra refcnt */
2898 if (ret || *ptr == NULL) {
2899 if (PageAnon(page)) {
2900 lock_page_cgroup(pc);
2901 ClearPageCgroupMigration(pc);
2902 unlock_page_cgroup(pc);
2904 * The old page may be fully unmapped while we kept it.
2906 mem_cgroup_uncharge_page(page);
2911 * We charge new page before it's used/mapped. So, even if unlock_page()
2912 * is called before end_migration, we can catch all events on this new
2913 * page. In the case new page is migrated but not remapped, new page's
2914 * mapcount will be finally 0 and we call uncharge in end_migration().
2916 pc = lookup_page_cgroup(newpage);
2918 ctype = MEM_CGROUP_CHARGE_TYPE_MAPPED;
2919 else if (page_is_file_cache(page))
2920 ctype = MEM_CGROUP_CHARGE_TYPE_CACHE;
2922 ctype = MEM_CGROUP_CHARGE_TYPE_SHMEM;
2923 __mem_cgroup_commit_charge(mem, pc, ctype, PAGE_SIZE);
2927 /* remove redundant charge if migration failed*/
2928 void mem_cgroup_end_migration(struct mem_cgroup *mem,
2929 struct page *oldpage, struct page *newpage, bool migration_ok)
2931 struct page *used, *unused;
2932 struct page_cgroup *pc;
2936 /* blocks rmdir() */
2937 cgroup_exclude_rmdir(&mem->css);
2938 if (!migration_ok) {
2946 * We disallowed uncharge of pages under migration because mapcount
2947 * of the page goes down to zero, temporarly.
2948 * Clear the flag and check the page should be charged.
2950 pc = lookup_page_cgroup(oldpage);
2951 lock_page_cgroup(pc);
2952 ClearPageCgroupMigration(pc);
2953 unlock_page_cgroup(pc);
2955 __mem_cgroup_uncharge_common(unused, MEM_CGROUP_CHARGE_TYPE_FORCE);
2958 * If a page is a file cache, radix-tree replacement is very atomic
2959 * and we can skip this check. When it was an Anon page, its mapcount
2960 * goes down to 0. But because we added MIGRATION flage, it's not
2961 * uncharged yet. There are several case but page->mapcount check
2962 * and USED bit check in mem_cgroup_uncharge_page() will do enough
2963 * check. (see prepare_charge() also)
2966 mem_cgroup_uncharge_page(used);
2968 * At migration, we may charge account against cgroup which has no
2970 * So, rmdir()->pre_destroy() can be called while we do this charge.
2971 * In that case, we need to call pre_destroy() again. check it here.
2973 cgroup_release_and_wakeup_rmdir(&mem->css);
2977 * A call to try to shrink memory usage on charge failure at shmem's swapin.
2978 * Calling hierarchical_reclaim is not enough because we should update
2979 * last_oom_jiffies to prevent pagefault_out_of_memory from invoking global OOM.
2980 * Moreover considering hierarchy, we should reclaim from the mem_over_limit,
2981 * not from the memcg which this page would be charged to.
2982 * try_charge_swapin does all of these works properly.
2984 int mem_cgroup_shmem_charge_fallback(struct page *page,
2985 struct mm_struct *mm,
2988 struct mem_cgroup *mem = NULL;
2991 if (mem_cgroup_disabled())
2994 ret = mem_cgroup_try_charge_swapin(mm, page, gfp_mask, &mem);
2996 mem_cgroup_cancel_charge_swapin(mem); /* it does !mem check */
3001 static DEFINE_MUTEX(set_limit_mutex);
3003 static int mem_cgroup_resize_limit(struct mem_cgroup *memcg,
3004 unsigned long long val)
3007 u64 memswlimit, memlimit;
3009 int children = mem_cgroup_count_children(memcg);
3010 u64 curusage, oldusage;
3014 * For keeping hierarchical_reclaim simple, how long we should retry
3015 * is depends on callers. We set our retry-count to be function
3016 * of # of children which we should visit in this loop.
3018 retry_count = MEM_CGROUP_RECLAIM_RETRIES * children;
3020 oldusage = res_counter_read_u64(&memcg->res, RES_USAGE);
3023 while (retry_count) {
3024 if (signal_pending(current)) {
3029 * Rather than hide all in some function, I do this in
3030 * open coded manner. You see what this really does.
3031 * We have to guarantee mem->res.limit < mem->memsw.limit.
3033 mutex_lock(&set_limit_mutex);
3034 memswlimit = res_counter_read_u64(&memcg->memsw, RES_LIMIT);
3035 if (memswlimit < val) {
3037 mutex_unlock(&set_limit_mutex);
3041 memlimit = res_counter_read_u64(&memcg->res, RES_LIMIT);
3045 ret = res_counter_set_limit(&memcg->res, val);
3047 if (memswlimit == val)
3048 memcg->memsw_is_minimum = true;
3050 memcg->memsw_is_minimum = false;
3052 mutex_unlock(&set_limit_mutex);
3057 mem_cgroup_hierarchical_reclaim(memcg, NULL, GFP_KERNEL,
3058 MEM_CGROUP_RECLAIM_SHRINK);
3059 curusage = res_counter_read_u64(&memcg->res, RES_USAGE);
3060 /* Usage is reduced ? */
3061 if (curusage >= oldusage)
3064 oldusage = curusage;
3066 if (!ret && enlarge)
3067 memcg_oom_recover(memcg);
3072 static int mem_cgroup_resize_memsw_limit(struct mem_cgroup *memcg,
3073 unsigned long long val)
3076 u64 memlimit, memswlimit, oldusage, curusage;
3077 int children = mem_cgroup_count_children(memcg);
3081 /* see mem_cgroup_resize_res_limit */
3082 retry_count = children * MEM_CGROUP_RECLAIM_RETRIES;
3083 oldusage = res_counter_read_u64(&memcg->memsw, RES_USAGE);
3084 while (retry_count) {
3085 if (signal_pending(current)) {
3090 * Rather than hide all in some function, I do this in
3091 * open coded manner. You see what this really does.
3092 * We have to guarantee mem->res.limit < mem->memsw.limit.
3094 mutex_lock(&set_limit_mutex);
3095 memlimit = res_counter_read_u64(&memcg->res, RES_LIMIT);
3096 if (memlimit > val) {
3098 mutex_unlock(&set_limit_mutex);
3101 memswlimit = res_counter_read_u64(&memcg->memsw, RES_LIMIT);
3102 if (memswlimit < val)
3104 ret = res_counter_set_limit(&memcg->memsw, val);
3106 if (memlimit == val)
3107 memcg->memsw_is_minimum = true;
3109 memcg->memsw_is_minimum = false;
3111 mutex_unlock(&set_limit_mutex);
3116 mem_cgroup_hierarchical_reclaim(memcg, NULL, GFP_KERNEL,
3117 MEM_CGROUP_RECLAIM_NOSWAP |
3118 MEM_CGROUP_RECLAIM_SHRINK);
3119 curusage = res_counter_read_u64(&memcg->memsw, RES_USAGE);
3120 /* Usage is reduced ? */
3121 if (curusage >= oldusage)
3124 oldusage = curusage;
3126 if (!ret && enlarge)
3127 memcg_oom_recover(memcg);
3131 unsigned long mem_cgroup_soft_limit_reclaim(struct zone *zone, int order,
3134 unsigned long nr_reclaimed = 0;
3135 struct mem_cgroup_per_zone *mz, *next_mz = NULL;
3136 unsigned long reclaimed;
3138 struct mem_cgroup_tree_per_zone *mctz;
3139 unsigned long long excess;
3144 mctz = soft_limit_tree_node_zone(zone_to_nid(zone), zone_idx(zone));
3146 * This loop can run a while, specially if mem_cgroup's continuously
3147 * keep exceeding their soft limit and putting the system under
3154 mz = mem_cgroup_largest_soft_limit_node(mctz);
3158 reclaimed = mem_cgroup_hierarchical_reclaim(mz->mem, zone,
3160 MEM_CGROUP_RECLAIM_SOFT);
3161 nr_reclaimed += reclaimed;
3162 spin_lock(&mctz->lock);
3165 * If we failed to reclaim anything from this memory cgroup
3166 * it is time to move on to the next cgroup
3172 * Loop until we find yet another one.
3174 * By the time we get the soft_limit lock
3175 * again, someone might have aded the
3176 * group back on the RB tree. Iterate to
3177 * make sure we get a different mem.
3178 * mem_cgroup_largest_soft_limit_node returns
3179 * NULL if no other cgroup is present on
3183 __mem_cgroup_largest_soft_limit_node(mctz);
3184 if (next_mz == mz) {
3185 css_put(&next_mz->mem->css);
3187 } else /* next_mz == NULL or other memcg */
3191 __mem_cgroup_remove_exceeded(mz->mem, mz, mctz);
3192 excess = res_counter_soft_limit_excess(&mz->mem->res);
3194 * One school of thought says that we should not add
3195 * back the node to the tree if reclaim returns 0.
3196 * But our reclaim could return 0, simply because due
3197 * to priority we are exposing a smaller subset of
3198 * memory to reclaim from. Consider this as a longer
3201 /* If excess == 0, no tree ops */
3202 __mem_cgroup_insert_exceeded(mz->mem, mz, mctz, excess);
3203 spin_unlock(&mctz->lock);
3204 css_put(&mz->mem->css);
3207 * Could not reclaim anything and there are no more
3208 * mem cgroups to try or we seem to be looping without
3209 * reclaiming anything.
3211 if (!nr_reclaimed &&
3213 loop > MEM_CGROUP_MAX_SOFT_LIMIT_RECLAIM_LOOPS))
3215 } while (!nr_reclaimed);
3217 css_put(&next_mz->mem->css);
3218 return nr_reclaimed;
3222 * This routine traverse page_cgroup in given list and drop them all.
3223 * *And* this routine doesn't reclaim page itself, just removes page_cgroup.
3225 static int mem_cgroup_force_empty_list(struct mem_cgroup *mem,
3226 int node, int zid, enum lru_list lru)
3229 struct mem_cgroup_per_zone *mz;
3230 struct page_cgroup *pc, *busy;
3231 unsigned long flags, loop;
3232 struct list_head *list;
3235 zone = &NODE_DATA(node)->node_zones[zid];
3236 mz = mem_cgroup_zoneinfo(mem, node, zid);
3237 list = &mz->lists[lru];
3239 loop = MEM_CGROUP_ZSTAT(mz, lru);
3240 /* give some margin against EBUSY etc...*/
3245 spin_lock_irqsave(&zone->lru_lock, flags);
3246 if (list_empty(list)) {
3247 spin_unlock_irqrestore(&zone->lru_lock, flags);
3250 pc = list_entry(list->prev, struct page_cgroup, lru);
3252 list_move(&pc->lru, list);
3254 spin_unlock_irqrestore(&zone->lru_lock, flags);
3257 spin_unlock_irqrestore(&zone->lru_lock, flags);
3259 ret = mem_cgroup_move_parent(pc, mem, GFP_KERNEL);
3263 if (ret == -EBUSY || ret == -EINVAL) {
3264 /* found lock contention or "pc" is obsolete. */
3271 if (!ret && !list_empty(list))
3277 * make mem_cgroup's charge to be 0 if there is no task.
3278 * This enables deleting this mem_cgroup.
3280 static int mem_cgroup_force_empty(struct mem_cgroup *mem, bool free_all)
3283 int node, zid, shrink;
3284 int nr_retries = MEM_CGROUP_RECLAIM_RETRIES;
3285 struct cgroup *cgrp = mem->css.cgroup;
3290 /* should free all ? */
3296 if (cgroup_task_count(cgrp) || !list_empty(&cgrp->children))
3299 if (signal_pending(current))
3301 /* This is for making all *used* pages to be on LRU. */
3302 lru_add_drain_all();
3303 drain_all_stock_sync();
3305 mem_cgroup_start_move(mem);
3306 for_each_node_state(node, N_HIGH_MEMORY) {
3307 for (zid = 0; !ret && zid < MAX_NR_ZONES; zid++) {
3310 ret = mem_cgroup_force_empty_list(mem,
3319 mem_cgroup_end_move(mem);
3320 memcg_oom_recover(mem);
3321 /* it seems parent cgroup doesn't have enough mem */
3325 /* "ret" should also be checked to ensure all lists are empty. */
3326 } while (mem->res.usage > 0 || ret);
3332 /* returns EBUSY if there is a task or if we come here twice. */
3333 if (cgroup_task_count(cgrp) || !list_empty(&cgrp->children) || shrink) {
3337 /* we call try-to-free pages for make this cgroup empty */
3338 lru_add_drain_all();
3339 /* try to free all pages in this cgroup */
3341 while (nr_retries && mem->res.usage > 0) {
3344 if (signal_pending(current)) {
3348 progress = try_to_free_mem_cgroup_pages(mem, GFP_KERNEL,
3349 false, get_swappiness(mem));
3352 /* maybe some writeback is necessary */
3353 congestion_wait(BLK_RW_ASYNC, HZ/10);
3358 /* try move_account...there may be some *locked* pages. */
3362 int mem_cgroup_force_empty_write(struct cgroup *cont, unsigned int event)
3364 return mem_cgroup_force_empty(mem_cgroup_from_cont(cont), true);
3368 static u64 mem_cgroup_hierarchy_read(struct cgroup *cont, struct cftype *cft)
3370 return mem_cgroup_from_cont(cont)->use_hierarchy;
3373 static int mem_cgroup_hierarchy_write(struct cgroup *cont, struct cftype *cft,
3377 struct mem_cgroup *mem = mem_cgroup_from_cont(cont);
3378 struct cgroup *parent = cont->parent;
3379 struct mem_cgroup *parent_mem = NULL;
3382 parent_mem = mem_cgroup_from_cont(parent);
3386 * If parent's use_hierarchy is set, we can't make any modifications
3387 * in the child subtrees. If it is unset, then the change can
3388 * occur, provided the current cgroup has no children.
3390 * For the root cgroup, parent_mem is NULL, we allow value to be
3391 * set if there are no children.
3393 if ((!parent_mem || !parent_mem->use_hierarchy) &&
3394 (val == 1 || val == 0)) {
3395 if (list_empty(&cont->children))
3396 mem->use_hierarchy = val;
3407 static u64 mem_cgroup_get_recursive_idx_stat(struct mem_cgroup *mem,
3408 enum mem_cgroup_stat_index idx)
3410 struct mem_cgroup *iter;
3413 /* each per cpu's value can be minus.Then, use s64 */
3414 for_each_mem_cgroup_tree(iter, mem)
3415 val += mem_cgroup_read_stat(iter, idx);
3417 if (val < 0) /* race ? */
3422 static inline u64 mem_cgroup_usage(struct mem_cgroup *mem, bool swap)
3426 if (!mem_cgroup_is_root(mem)) {
3428 return res_counter_read_u64(&mem->res, RES_USAGE);
3430 return res_counter_read_u64(&mem->memsw, RES_USAGE);
3433 val = mem_cgroup_get_recursive_idx_stat(mem, MEM_CGROUP_STAT_CACHE);
3434 val += mem_cgroup_get_recursive_idx_stat(mem, MEM_CGROUP_STAT_RSS);
3437 val += mem_cgroup_get_recursive_idx_stat(mem,
3438 MEM_CGROUP_STAT_SWAPOUT);
3440 return val << PAGE_SHIFT;
3443 static u64 mem_cgroup_read(struct cgroup *cont, struct cftype *cft)
3445 struct mem_cgroup *mem = mem_cgroup_from_cont(cont);
3449 type = MEMFILE_TYPE(cft->private);
3450 name = MEMFILE_ATTR(cft->private);
3453 if (name == RES_USAGE)
3454 val = mem_cgroup_usage(mem, false);
3456 val = res_counter_read_u64(&mem->res, name);
3459 if (name == RES_USAGE)
3460 val = mem_cgroup_usage(mem, true);
3462 val = res_counter_read_u64(&mem->memsw, name);
3471 * The user of this function is...
3474 static int mem_cgroup_write(struct cgroup *cont, struct cftype *cft,
3477 struct mem_cgroup *memcg = mem_cgroup_from_cont(cont);
3479 unsigned long long val;
3482 type = MEMFILE_TYPE(cft->private);
3483 name = MEMFILE_ATTR(cft->private);
3486 if (mem_cgroup_is_root(memcg)) { /* Can't set limit on root */
3490 /* This function does all necessary parse...reuse it */
3491 ret = res_counter_memparse_write_strategy(buffer, &val);
3495 ret = mem_cgroup_resize_limit(memcg, val);
3497 ret = mem_cgroup_resize_memsw_limit(memcg, val);
3499 case RES_SOFT_LIMIT:
3500 ret = res_counter_memparse_write_strategy(buffer, &val);
3504 * For memsw, soft limits are hard to implement in terms
3505 * of semantics, for now, we support soft limits for
3506 * control without swap
3509 ret = res_counter_set_soft_limit(&memcg->res, val);
3514 ret = -EINVAL; /* should be BUG() ? */
3520 static void memcg_get_hierarchical_limit(struct mem_cgroup *memcg,
3521 unsigned long long *mem_limit, unsigned long long *memsw_limit)
3523 struct cgroup *cgroup;
3524 unsigned long long min_limit, min_memsw_limit, tmp;
3526 min_limit = res_counter_read_u64(&memcg->res, RES_LIMIT);
3527 min_memsw_limit = res_counter_read_u64(&memcg->memsw, RES_LIMIT);
3528 cgroup = memcg->css.cgroup;
3529 if (!memcg->use_hierarchy)
3532 while (cgroup->parent) {
3533 cgroup = cgroup->parent;
3534 memcg = mem_cgroup_from_cont(cgroup);
3535 if (!memcg->use_hierarchy)
3537 tmp = res_counter_read_u64(&memcg->res, RES_LIMIT);
3538 min_limit = min(min_limit, tmp);
3539 tmp = res_counter_read_u64(&memcg->memsw, RES_LIMIT);
3540 min_memsw_limit = min(min_memsw_limit, tmp);
3543 *mem_limit = min_limit;
3544 *memsw_limit = min_memsw_limit;
3548 static int mem_cgroup_reset(struct cgroup *cont, unsigned int event)
3550 struct mem_cgroup *mem;
3553 mem = mem_cgroup_from_cont(cont);
3554 type = MEMFILE_TYPE(event);
3555 name = MEMFILE_ATTR(event);
3559 res_counter_reset_max(&mem->res);
3561 res_counter_reset_max(&mem->memsw);
3565 res_counter_reset_failcnt(&mem->res);
3567 res_counter_reset_failcnt(&mem->memsw);
3574 static u64 mem_cgroup_move_charge_read(struct cgroup *cgrp,
3577 return mem_cgroup_from_cont(cgrp)->move_charge_at_immigrate;
3581 static int mem_cgroup_move_charge_write(struct cgroup *cgrp,
3582 struct cftype *cft, u64 val)
3584 struct mem_cgroup *mem = mem_cgroup_from_cont(cgrp);
3586 if (val >= (1 << NR_MOVE_TYPE))
3589 * We check this value several times in both in can_attach() and
3590 * attach(), so we need cgroup lock to prevent this value from being
3594 mem->move_charge_at_immigrate = val;
3600 static int mem_cgroup_move_charge_write(struct cgroup *cgrp,
3601 struct cftype *cft, u64 val)
3608 /* For read statistics */
3624 struct mcs_total_stat {
3625 s64 stat[NR_MCS_STAT];
3631 } memcg_stat_strings[NR_MCS_STAT] = {
3632 {"cache", "total_cache"},
3633 {"rss", "total_rss"},
3634 {"mapped_file", "total_mapped_file"},
3635 {"pgpgin", "total_pgpgin"},
3636 {"pgpgout", "total_pgpgout"},
3637 {"swap", "total_swap"},
3638 {"inactive_anon", "total_inactive_anon"},
3639 {"active_anon", "total_active_anon"},
3640 {"inactive_file", "total_inactive_file"},
3641 {"active_file", "total_active_file"},
3642 {"unevictable", "total_unevictable"}
3647 mem_cgroup_get_local_stat(struct mem_cgroup *mem, struct mcs_total_stat *s)
3652 val = mem_cgroup_read_stat(mem, MEM_CGROUP_STAT_CACHE);
3653 s->stat[MCS_CACHE] += val * PAGE_SIZE;
3654 val = mem_cgroup_read_stat(mem, MEM_CGROUP_STAT_RSS);
3655 s->stat[MCS_RSS] += val * PAGE_SIZE;
3656 val = mem_cgroup_read_stat(mem, MEM_CGROUP_STAT_FILE_MAPPED);
3657 s->stat[MCS_FILE_MAPPED] += val * PAGE_SIZE;
3658 val = mem_cgroup_read_stat(mem, MEM_CGROUP_STAT_PGPGIN_COUNT);
3659 s->stat[MCS_PGPGIN] += val;
3660 val = mem_cgroup_read_stat(mem, MEM_CGROUP_STAT_PGPGOUT_COUNT);
3661 s->stat[MCS_PGPGOUT] += val;
3662 if (do_swap_account) {
3663 val = mem_cgroup_read_stat(mem, MEM_CGROUP_STAT_SWAPOUT);
3664 s->stat[MCS_SWAP] += val * PAGE_SIZE;
3668 val = mem_cgroup_get_local_zonestat(mem, LRU_INACTIVE_ANON);
3669 s->stat[MCS_INACTIVE_ANON] += val * PAGE_SIZE;
3670 val = mem_cgroup_get_local_zonestat(mem, LRU_ACTIVE_ANON);
3671 s->stat[MCS_ACTIVE_ANON] += val * PAGE_SIZE;
3672 val = mem_cgroup_get_local_zonestat(mem, LRU_INACTIVE_FILE);
3673 s->stat[MCS_INACTIVE_FILE] += val * PAGE_SIZE;
3674 val = mem_cgroup_get_local_zonestat(mem, LRU_ACTIVE_FILE);
3675 s->stat[MCS_ACTIVE_FILE] += val * PAGE_SIZE;
3676 val = mem_cgroup_get_local_zonestat(mem, LRU_UNEVICTABLE);
3677 s->stat[MCS_UNEVICTABLE] += val * PAGE_SIZE;
3681 mem_cgroup_get_total_stat(struct mem_cgroup *mem, struct mcs_total_stat *s)
3683 struct mem_cgroup *iter;
3685 for_each_mem_cgroup_tree(iter, mem)
3686 mem_cgroup_get_local_stat(iter, s);
3689 static int mem_control_stat_show(struct cgroup *cont, struct cftype *cft,
3690 struct cgroup_map_cb *cb)
3692 struct mem_cgroup *mem_cont = mem_cgroup_from_cont(cont);
3693 struct mcs_total_stat mystat;
3696 memset(&mystat, 0, sizeof(mystat));
3697 mem_cgroup_get_local_stat(mem_cont, &mystat);
3699 for (i = 0; i < NR_MCS_STAT; i++) {
3700 if (i == MCS_SWAP && !do_swap_account)
3702 cb->fill(cb, memcg_stat_strings[i].local_name, mystat.stat[i]);
3705 /* Hierarchical information */
3707 unsigned long long limit, memsw_limit;
3708 memcg_get_hierarchical_limit(mem_cont, &limit, &memsw_limit);
3709 cb->fill(cb, "hierarchical_memory_limit", limit);
3710 if (do_swap_account)
3711 cb->fill(cb, "hierarchical_memsw_limit", memsw_limit);
3714 memset(&mystat, 0, sizeof(mystat));
3715 mem_cgroup_get_total_stat(mem_cont, &mystat);
3716 for (i = 0; i < NR_MCS_STAT; i++) {
3717 if (i == MCS_SWAP && !do_swap_account)
3719 cb->fill(cb, memcg_stat_strings[i].total_name, mystat.stat[i]);
3722 #ifdef CONFIG_DEBUG_VM
3723 cb->fill(cb, "inactive_ratio", calc_inactive_ratio(mem_cont, NULL));
3727 struct mem_cgroup_per_zone *mz;
3728 unsigned long recent_rotated[2] = {0, 0};
3729 unsigned long recent_scanned[2] = {0, 0};
3731 for_each_online_node(nid)
3732 for (zid = 0; zid < MAX_NR_ZONES; zid++) {
3733 mz = mem_cgroup_zoneinfo(mem_cont, nid, zid);
3735 recent_rotated[0] +=
3736 mz->reclaim_stat.recent_rotated[0];
3737 recent_rotated[1] +=
3738 mz->reclaim_stat.recent_rotated[1];
3739 recent_scanned[0] +=
3740 mz->reclaim_stat.recent_scanned[0];
3741 recent_scanned[1] +=
3742 mz->reclaim_stat.recent_scanned[1];
3744 cb->fill(cb, "recent_rotated_anon", recent_rotated[0]);
3745 cb->fill(cb, "recent_rotated_file", recent_rotated[1]);
3746 cb->fill(cb, "recent_scanned_anon", recent_scanned[0]);
3747 cb->fill(cb, "recent_scanned_file", recent_scanned[1]);
3754 static u64 mem_cgroup_swappiness_read(struct cgroup *cgrp, struct cftype *cft)
3756 struct mem_cgroup *memcg = mem_cgroup_from_cont(cgrp);
3758 return get_swappiness(memcg);
3761 static int mem_cgroup_swappiness_write(struct cgroup *cgrp, struct cftype *cft,
3764 struct mem_cgroup *memcg = mem_cgroup_from_cont(cgrp);
3765 struct mem_cgroup *parent;
3770 if (cgrp->parent == NULL)
3773 parent = mem_cgroup_from_cont(cgrp->parent);
3777 /* If under hierarchy, only empty-root can set this value */
3778 if ((parent->use_hierarchy) ||
3779 (memcg->use_hierarchy && !list_empty(&cgrp->children))) {
3784 spin_lock(&memcg->reclaim_param_lock);
3785 memcg->swappiness = val;
3786 spin_unlock(&memcg->reclaim_param_lock);
3793 static void __mem_cgroup_threshold(struct mem_cgroup *memcg, bool swap)
3795 struct mem_cgroup_threshold_ary *t;
3801 t = rcu_dereference(memcg->thresholds.primary);
3803 t = rcu_dereference(memcg->memsw_thresholds.primary);
3808 usage = mem_cgroup_usage(memcg, swap);
3811 * current_threshold points to threshold just below usage.
3812 * If it's not true, a threshold was crossed after last
3813 * call of __mem_cgroup_threshold().
3815 i = t->current_threshold;
3818 * Iterate backward over array of thresholds starting from
3819 * current_threshold and check if a threshold is crossed.
3820 * If none of thresholds below usage is crossed, we read
3821 * only one element of the array here.
3823 for (; i >= 0 && unlikely(t->entries[i].threshold > usage); i--)
3824 eventfd_signal(t->entries[i].eventfd, 1);
3826 /* i = current_threshold + 1 */
3830 * Iterate forward over array of thresholds starting from
3831 * current_threshold+1 and check if a threshold is crossed.
3832 * If none of thresholds above usage is crossed, we read
3833 * only one element of the array here.
3835 for (; i < t->size && unlikely(t->entries[i].threshold <= usage); i++)
3836 eventfd_signal(t->entries[i].eventfd, 1);
3838 /* Update current_threshold */
3839 t->current_threshold = i - 1;
3844 static void mem_cgroup_threshold(struct mem_cgroup *memcg)
3847 __mem_cgroup_threshold(memcg, false);
3848 if (do_swap_account)
3849 __mem_cgroup_threshold(memcg, true);
3851 memcg = parent_mem_cgroup(memcg);
3855 static int compare_thresholds(const void *a, const void *b)
3857 const struct mem_cgroup_threshold *_a = a;
3858 const struct mem_cgroup_threshold *_b = b;
3860 return _a->threshold - _b->threshold;
3863 static int mem_cgroup_oom_notify_cb(struct mem_cgroup *mem)
3865 struct mem_cgroup_eventfd_list *ev;
3867 list_for_each_entry(ev, &mem->oom_notify, list)
3868 eventfd_signal(ev->eventfd, 1);
3872 static void mem_cgroup_oom_notify(struct mem_cgroup *mem)
3874 struct mem_cgroup *iter;
3876 for_each_mem_cgroup_tree(iter, mem)
3877 mem_cgroup_oom_notify_cb(iter);
3880 static int mem_cgroup_usage_register_event(struct cgroup *cgrp,
3881 struct cftype *cft, struct eventfd_ctx *eventfd, const char *args)
3883 struct mem_cgroup *memcg = mem_cgroup_from_cont(cgrp);
3884 struct mem_cgroup_thresholds *thresholds;
3885 struct mem_cgroup_threshold_ary *new;
3886 int type = MEMFILE_TYPE(cft->private);
3887 u64 threshold, usage;
3890 ret = res_counter_memparse_write_strategy(args, &threshold);
3894 mutex_lock(&memcg->thresholds_lock);
3897 thresholds = &memcg->thresholds;
3898 else if (type == _MEMSWAP)
3899 thresholds = &memcg->memsw_thresholds;
3903 usage = mem_cgroup_usage(memcg, type == _MEMSWAP);
3905 /* Check if a threshold crossed before adding a new one */
3906 if (thresholds->primary)
3907 __mem_cgroup_threshold(memcg, type == _MEMSWAP);
3909 size = thresholds->primary ? thresholds->primary->size + 1 : 1;
3911 /* Allocate memory for new array of thresholds */
3912 new = kmalloc(sizeof(*new) + size * sizeof(struct mem_cgroup_threshold),
3920 /* Copy thresholds (if any) to new array */
3921 if (thresholds->primary) {
3922 memcpy(new->entries, thresholds->primary->entries, (size - 1) *
3923 sizeof(struct mem_cgroup_threshold));
3926 /* Add new threshold */
3927 new->entries[size - 1].eventfd = eventfd;
3928 new->entries[size - 1].threshold = threshold;
3930 /* Sort thresholds. Registering of new threshold isn't time-critical */
3931 sort(new->entries, size, sizeof(struct mem_cgroup_threshold),
3932 compare_thresholds, NULL);
3934 /* Find current threshold */
3935 new->current_threshold = -1;
3936 for (i = 0; i < size; i++) {
3937 if (new->entries[i].threshold < usage) {
3939 * new->current_threshold will not be used until
3940 * rcu_assign_pointer(), so it's safe to increment
3943 ++new->current_threshold;
3947 /* Free old spare buffer and save old primary buffer as spare */
3948 kfree(thresholds->spare);
3949 thresholds->spare = thresholds->primary;
3951 rcu_assign_pointer(thresholds->primary, new);
3953 /* To be sure that nobody uses thresholds */
3957 mutex_unlock(&memcg->thresholds_lock);
3962 static void mem_cgroup_usage_unregister_event(struct cgroup *cgrp,
3963 struct cftype *cft, struct eventfd_ctx *eventfd)
3965 struct mem_cgroup *memcg = mem_cgroup_from_cont(cgrp);
3966 struct mem_cgroup_thresholds *thresholds;
3967 struct mem_cgroup_threshold_ary *new;
3968 int type = MEMFILE_TYPE(cft->private);
3972 mutex_lock(&memcg->thresholds_lock);
3974 thresholds = &memcg->thresholds;
3975 else if (type == _MEMSWAP)
3976 thresholds = &memcg->memsw_thresholds;
3981 * Something went wrong if we trying to unregister a threshold
3982 * if we don't have thresholds
3984 BUG_ON(!thresholds);
3986 usage = mem_cgroup_usage(memcg, type == _MEMSWAP);
3988 /* Check if a threshold crossed before removing */
3989 __mem_cgroup_threshold(memcg, type == _MEMSWAP);
3991 /* Calculate new number of threshold */
3993 for (i = 0; i < thresholds->primary->size; i++) {
3994 if (thresholds->primary->entries[i].eventfd != eventfd)
3998 new = thresholds->spare;
4000 /* Set thresholds array to NULL if we don't have thresholds */
4009 /* Copy thresholds and find current threshold */
4010 new->current_threshold = -1;
4011 for (i = 0, j = 0; i < thresholds->primary->size; i++) {
4012 if (thresholds->primary->entries[i].eventfd == eventfd)
4015 new->entries[j] = thresholds->primary->entries[i];
4016 if (new->entries[j].threshold < usage) {
4018 * new->current_threshold will not be used
4019 * until rcu_assign_pointer(), so it's safe to increment
4022 ++new->current_threshold;
4028 /* Swap primary and spare array */
4029 thresholds->spare = thresholds->primary;
4030 rcu_assign_pointer(thresholds->primary, new);
4032 /* To be sure that nobody uses thresholds */
4035 mutex_unlock(&memcg->thresholds_lock);
4038 static int mem_cgroup_oom_register_event(struct cgroup *cgrp,
4039 struct cftype *cft, struct eventfd_ctx *eventfd, const char *args)
4041 struct mem_cgroup *memcg = mem_cgroup_from_cont(cgrp);
4042 struct mem_cgroup_eventfd_list *event;
4043 int type = MEMFILE_TYPE(cft->private);
4045 BUG_ON(type != _OOM_TYPE);
4046 event = kmalloc(sizeof(*event), GFP_KERNEL);
4050 mutex_lock(&memcg_oom_mutex);
4052 event->eventfd = eventfd;
4053 list_add(&event->list, &memcg->oom_notify);
4055 /* already in OOM ? */
4056 if (atomic_read(&memcg->oom_lock))
4057 eventfd_signal(eventfd, 1);
4058 mutex_unlock(&memcg_oom_mutex);
4063 static void mem_cgroup_oom_unregister_event(struct cgroup *cgrp,
4064 struct cftype *cft, struct eventfd_ctx *eventfd)
4066 struct mem_cgroup *mem = mem_cgroup_from_cont(cgrp);
4067 struct mem_cgroup_eventfd_list *ev, *tmp;
4068 int type = MEMFILE_TYPE(cft->private);
4070 BUG_ON(type != _OOM_TYPE);
4072 mutex_lock(&memcg_oom_mutex);
4074 list_for_each_entry_safe(ev, tmp, &mem->oom_notify, list) {
4075 if (ev->eventfd == eventfd) {
4076 list_del(&ev->list);
4081 mutex_unlock(&memcg_oom_mutex);
4084 static int mem_cgroup_oom_control_read(struct cgroup *cgrp,
4085 struct cftype *cft, struct cgroup_map_cb *cb)
4087 struct mem_cgroup *mem = mem_cgroup_from_cont(cgrp);
4089 cb->fill(cb, "oom_kill_disable", mem->oom_kill_disable);
4091 if (atomic_read(&mem->oom_lock))
4092 cb->fill(cb, "under_oom", 1);
4094 cb->fill(cb, "under_oom", 0);
4098 static int mem_cgroup_oom_control_write(struct cgroup *cgrp,
4099 struct cftype *cft, u64 val)
4101 struct mem_cgroup *mem = mem_cgroup_from_cont(cgrp);
4102 struct mem_cgroup *parent;
4104 /* cannot set to root cgroup and only 0 and 1 are allowed */
4105 if (!cgrp->parent || !((val == 0) || (val == 1)))
4108 parent = mem_cgroup_from_cont(cgrp->parent);
4111 /* oom-kill-disable is a flag for subhierarchy. */
4112 if ((parent->use_hierarchy) ||
4113 (mem->use_hierarchy && !list_empty(&cgrp->children))) {
4117 mem->oom_kill_disable = val;
4119 memcg_oom_recover(mem);
4124 static struct cftype mem_cgroup_files[] = {
4126 .name = "usage_in_bytes",
4127 .private = MEMFILE_PRIVATE(_MEM, RES_USAGE),
4128 .read_u64 = mem_cgroup_read,
4129 .register_event = mem_cgroup_usage_register_event,
4130 .unregister_event = mem_cgroup_usage_unregister_event,
4133 .name = "max_usage_in_bytes",
4134 .private = MEMFILE_PRIVATE(_MEM, RES_MAX_USAGE),
4135 .trigger = mem_cgroup_reset,
4136 .read_u64 = mem_cgroup_read,
4139 .name = "limit_in_bytes",
4140 .private = MEMFILE_PRIVATE(_MEM, RES_LIMIT),
4141 .write_string = mem_cgroup_write,
4142 .read_u64 = mem_cgroup_read,
4145 .name = "soft_limit_in_bytes",
4146 .private = MEMFILE_PRIVATE(_MEM, RES_SOFT_LIMIT),
4147 .write_string = mem_cgroup_write,
4148 .read_u64 = mem_cgroup_read,
4152 .private = MEMFILE_PRIVATE(_MEM, RES_FAILCNT),
4153 .trigger = mem_cgroup_reset,
4154 .read_u64 = mem_cgroup_read,
4158 .read_map = mem_control_stat_show,
4161 .name = "force_empty",
4162 .trigger = mem_cgroup_force_empty_write,
4165 .name = "use_hierarchy",
4166 .write_u64 = mem_cgroup_hierarchy_write,
4167 .read_u64 = mem_cgroup_hierarchy_read,
4170 .name = "swappiness",
4171 .read_u64 = mem_cgroup_swappiness_read,
4172 .write_u64 = mem_cgroup_swappiness_write,
4175 .name = "move_charge_at_immigrate",
4176 .read_u64 = mem_cgroup_move_charge_read,
4177 .write_u64 = mem_cgroup_move_charge_write,
4180 .name = "oom_control",
4181 .read_map = mem_cgroup_oom_control_read,
4182 .write_u64 = mem_cgroup_oom_control_write,
4183 .register_event = mem_cgroup_oom_register_event,
4184 .unregister_event = mem_cgroup_oom_unregister_event,
4185 .private = MEMFILE_PRIVATE(_OOM_TYPE, OOM_CONTROL),
4189 #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP
4190 static struct cftype memsw_cgroup_files[] = {
4192 .name = "memsw.usage_in_bytes",
4193 .private = MEMFILE_PRIVATE(_MEMSWAP, RES_USAGE),
4194 .read_u64 = mem_cgroup_read,
4195 .register_event = mem_cgroup_usage_register_event,
4196 .unregister_event = mem_cgroup_usage_unregister_event,
4199 .name = "memsw.max_usage_in_bytes",
4200 .private = MEMFILE_PRIVATE(_MEMSWAP, RES_MAX_USAGE),
4201 .trigger = mem_cgroup_reset,
4202 .read_u64 = mem_cgroup_read,
4205 .name = "memsw.limit_in_bytes",
4206 .private = MEMFILE_PRIVATE(_MEMSWAP, RES_LIMIT),
4207 .write_string = mem_cgroup_write,
4208 .read_u64 = mem_cgroup_read,
4211 .name = "memsw.failcnt",
4212 .private = MEMFILE_PRIVATE(_MEMSWAP, RES_FAILCNT),
4213 .trigger = mem_cgroup_reset,
4214 .read_u64 = mem_cgroup_read,
4218 static int register_memsw_files(struct cgroup *cont, struct cgroup_subsys *ss)
4220 if (!do_swap_account)
4222 return cgroup_add_files(cont, ss, memsw_cgroup_files,
4223 ARRAY_SIZE(memsw_cgroup_files));
4226 static int register_memsw_files(struct cgroup *cont, struct cgroup_subsys *ss)
4232 static int alloc_mem_cgroup_per_zone_info(struct mem_cgroup *mem, int node)
4234 struct mem_cgroup_per_node *pn;
4235 struct mem_cgroup_per_zone *mz;
4237 int zone, tmp = node;
4239 * This routine is called against possible nodes.
4240 * But it's BUG to call kmalloc() against offline node.
4242 * TODO: this routine can waste much memory for nodes which will
4243 * never be onlined. It's better to use memory hotplug callback
4246 if (!node_state(node, N_NORMAL_MEMORY))
4248 pn = kzalloc_node(sizeof(*pn), GFP_KERNEL, tmp);
4252 mem->info.nodeinfo[node] = pn;
4253 for (zone = 0; zone < MAX_NR_ZONES; zone++) {
4254 mz = &pn->zoneinfo[zone];
4256 INIT_LIST_HEAD(&mz->lists[l]);
4257 mz->usage_in_excess = 0;
4258 mz->on_tree = false;
4264 static void free_mem_cgroup_per_zone_info(struct mem_cgroup *mem, int node)
4266 kfree(mem->info.nodeinfo[node]);
4269 static struct mem_cgroup *mem_cgroup_alloc(void)
4271 struct mem_cgroup *mem;
4272 int size = sizeof(struct mem_cgroup);
4274 /* Can be very big if MAX_NUMNODES is very big */
4275 if (size < PAGE_SIZE)
4276 mem = kzalloc(size, GFP_KERNEL);
4278 mem = vzalloc(size);
4283 mem->stat = alloc_percpu(struct mem_cgroup_stat_cpu);
4286 spin_lock_init(&mem->pcp_counter_lock);
4290 if (size < PAGE_SIZE)
4298 * At destroying mem_cgroup, references from swap_cgroup can remain.
4299 * (scanning all at force_empty is too costly...)
4301 * Instead of clearing all references at force_empty, we remember
4302 * the number of reference from swap_cgroup and free mem_cgroup when
4303 * it goes down to 0.
4305 * Removal of cgroup itself succeeds regardless of refs from swap.
4308 static void __mem_cgroup_free(struct mem_cgroup *mem)
4312 mem_cgroup_remove_from_trees(mem);
4313 free_css_id(&mem_cgroup_subsys, &mem->css);
4315 for_each_node_state(node, N_POSSIBLE)
4316 free_mem_cgroup_per_zone_info(mem, node);
4318 free_percpu(mem->stat);
4319 if (sizeof(struct mem_cgroup) < PAGE_SIZE)
4325 static void mem_cgroup_get(struct mem_cgroup *mem)
4327 atomic_inc(&mem->refcnt);
4330 static void __mem_cgroup_put(struct mem_cgroup *mem, int count)
4332 if (atomic_sub_and_test(count, &mem->refcnt)) {
4333 struct mem_cgroup *parent = parent_mem_cgroup(mem);
4334 __mem_cgroup_free(mem);
4336 mem_cgroup_put(parent);
4340 static void mem_cgroup_put(struct mem_cgroup *mem)
4342 __mem_cgroup_put(mem, 1);
4346 * Returns the parent mem_cgroup in memcgroup hierarchy with hierarchy enabled.
4348 static struct mem_cgroup *parent_mem_cgroup(struct mem_cgroup *mem)
4350 if (!mem->res.parent)
4352 return mem_cgroup_from_res_counter(mem->res.parent, res);
4355 #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP
4356 static void __init enable_swap_cgroup(void)
4358 if (!mem_cgroup_disabled() && really_do_swap_account)
4359 do_swap_account = 1;
4362 static void __init enable_swap_cgroup(void)
4367 static int mem_cgroup_soft_limit_tree_init(void)
4369 struct mem_cgroup_tree_per_node *rtpn;
4370 struct mem_cgroup_tree_per_zone *rtpz;
4371 int tmp, node, zone;
4373 for_each_node_state(node, N_POSSIBLE) {
4375 if (!node_state(node, N_NORMAL_MEMORY))
4377 rtpn = kzalloc_node(sizeof(*rtpn), GFP_KERNEL, tmp);
4381 soft_limit_tree.rb_tree_per_node[node] = rtpn;
4383 for (zone = 0; zone < MAX_NR_ZONES; zone++) {
4384 rtpz = &rtpn->rb_tree_per_zone[zone];
4385 rtpz->rb_root = RB_ROOT;
4386 spin_lock_init(&rtpz->lock);
4392 static struct cgroup_subsys_state * __ref
4393 mem_cgroup_create(struct cgroup_subsys *ss, struct cgroup *cont)
4395 struct mem_cgroup *mem, *parent;
4396 long error = -ENOMEM;
4399 mem = mem_cgroup_alloc();
4401 return ERR_PTR(error);
4403 for_each_node_state(node, N_POSSIBLE)
4404 if (alloc_mem_cgroup_per_zone_info(mem, node))
4408 if (cont->parent == NULL) {
4410 enable_swap_cgroup();
4412 root_mem_cgroup = mem;
4413 if (mem_cgroup_soft_limit_tree_init())
4415 for_each_possible_cpu(cpu) {
4416 struct memcg_stock_pcp *stock =
4417 &per_cpu(memcg_stock, cpu);
4418 INIT_WORK(&stock->work, drain_local_stock);
4420 hotcpu_notifier(memcg_cpu_hotplug_callback, 0);
4422 parent = mem_cgroup_from_cont(cont->parent);
4423 mem->use_hierarchy = parent->use_hierarchy;
4424 mem->oom_kill_disable = parent->oom_kill_disable;
4427 if (parent && parent->use_hierarchy) {
4428 res_counter_init(&mem->res, &parent->res);
4429 res_counter_init(&mem->memsw, &parent->memsw);
4431 * We increment refcnt of the parent to ensure that we can
4432 * safely access it on res_counter_charge/uncharge.
4433 * This refcnt will be decremented when freeing this
4434 * mem_cgroup(see mem_cgroup_put).
4436 mem_cgroup_get(parent);
4438 res_counter_init(&mem->res, NULL);
4439 res_counter_init(&mem->memsw, NULL);
4441 mem->last_scanned_child = 0;
4442 spin_lock_init(&mem->reclaim_param_lock);
4443 INIT_LIST_HEAD(&mem->oom_notify);
4446 mem->swappiness = get_swappiness(parent);
4447 atomic_set(&mem->refcnt, 1);
4448 mem->move_charge_at_immigrate = 0;
4449 mutex_init(&mem->thresholds_lock);
4452 __mem_cgroup_free(mem);
4453 root_mem_cgroup = NULL;
4454 return ERR_PTR(error);
4457 static int mem_cgroup_pre_destroy(struct cgroup_subsys *ss,
4458 struct cgroup *cont)
4460 struct mem_cgroup *mem = mem_cgroup_from_cont(cont);
4462 return mem_cgroup_force_empty(mem, false);
4465 static void mem_cgroup_destroy(struct cgroup_subsys *ss,
4466 struct cgroup *cont)
4468 struct mem_cgroup *mem = mem_cgroup_from_cont(cont);
4470 mem_cgroup_put(mem);
4473 static int mem_cgroup_populate(struct cgroup_subsys *ss,
4474 struct cgroup *cont)
4478 ret = cgroup_add_files(cont, ss, mem_cgroup_files,
4479 ARRAY_SIZE(mem_cgroup_files));
4482 ret = register_memsw_files(cont, ss);
4487 /* Handlers for move charge at task migration. */
4488 #define PRECHARGE_COUNT_AT_ONCE 256
4489 static int mem_cgroup_do_precharge(unsigned long count)
4492 int batch_count = PRECHARGE_COUNT_AT_ONCE;
4493 struct mem_cgroup *mem = mc.to;
4495 if (mem_cgroup_is_root(mem)) {
4496 mc.precharge += count;
4497 /* we don't need css_get for root */
4500 /* try to charge at once */
4502 struct res_counter *dummy;
4504 * "mem" cannot be under rmdir() because we've already checked
4505 * by cgroup_lock_live_cgroup() that it is not removed and we
4506 * are still under the same cgroup_mutex. So we can postpone
4509 if (res_counter_charge(&mem->res, PAGE_SIZE * count, &dummy))
4511 if (do_swap_account && res_counter_charge(&mem->memsw,
4512 PAGE_SIZE * count, &dummy)) {
4513 res_counter_uncharge(&mem->res, PAGE_SIZE * count);
4516 mc.precharge += count;
4520 /* fall back to one by one charge */
4522 if (signal_pending(current)) {
4526 if (!batch_count--) {
4527 batch_count = PRECHARGE_COUNT_AT_ONCE;
4530 ret = __mem_cgroup_try_charge(NULL, GFP_KERNEL, &mem, false,
4533 /* mem_cgroup_clear_mc() will do uncharge later */
4541 * is_target_pte_for_mc - check a pte whether it is valid for move charge
4542 * @vma: the vma the pte to be checked belongs
4543 * @addr: the address corresponding to the pte to be checked
4544 * @ptent: the pte to be checked
4545 * @target: the pointer the target page or swap ent will be stored(can be NULL)
4548 * 0(MC_TARGET_NONE): if the pte is not a target for move charge.
4549 * 1(MC_TARGET_PAGE): if the page corresponding to this pte is a target for
4550 * move charge. if @target is not NULL, the page is stored in target->page
4551 * with extra refcnt got(Callers should handle it).
4552 * 2(MC_TARGET_SWAP): if the swap entry corresponding to this pte is a
4553 * target for charge migration. if @target is not NULL, the entry is stored
4556 * Called with pte lock held.
4563 enum mc_target_type {
4564 MC_TARGET_NONE, /* not used */
4569 static struct page *mc_handle_present_pte(struct vm_area_struct *vma,
4570 unsigned long addr, pte_t ptent)
4572 struct page *page = vm_normal_page(vma, addr, ptent);
4574 if (!page || !page_mapped(page))
4576 if (PageAnon(page)) {
4577 /* we don't move shared anon */
4578 if (!move_anon() || page_mapcount(page) > 2)
4580 } else if (!move_file())
4581 /* we ignore mapcount for file pages */
4583 if (!get_page_unless_zero(page))
4589 static struct page *mc_handle_swap_pte(struct vm_area_struct *vma,
4590 unsigned long addr, pte_t ptent, swp_entry_t *entry)
4593 struct page *page = NULL;
4594 swp_entry_t ent = pte_to_swp_entry(ptent);
4596 if (!move_anon() || non_swap_entry(ent))
4598 usage_count = mem_cgroup_count_swap_user(ent, &page);
4599 if (usage_count > 1) { /* we don't move shared anon */
4604 if (do_swap_account)
4605 entry->val = ent.val;
4610 static struct page *mc_handle_file_pte(struct vm_area_struct *vma,
4611 unsigned long addr, pte_t ptent, swp_entry_t *entry)
4613 struct page *page = NULL;
4614 struct inode *inode;
4615 struct address_space *mapping;
4618 if (!vma->vm_file) /* anonymous vma */
4623 inode = vma->vm_file->f_path.dentry->d_inode;
4624 mapping = vma->vm_file->f_mapping;
4625 if (pte_none(ptent))
4626 pgoff = linear_page_index(vma, addr);
4627 else /* pte_file(ptent) is true */
4628 pgoff = pte_to_pgoff(ptent);
4630 /* page is moved even if it's not RSS of this task(page-faulted). */
4631 if (!mapping_cap_swap_backed(mapping)) { /* normal file */
4632 page = find_get_page(mapping, pgoff);
4633 } else { /* shmem/tmpfs file. we should take account of swap too. */
4635 mem_cgroup_get_shmem_target(inode, pgoff, &page, &ent);
4636 if (do_swap_account)
4637 entry->val = ent.val;
4643 static int is_target_pte_for_mc(struct vm_area_struct *vma,
4644 unsigned long addr, pte_t ptent, union mc_target *target)
4646 struct page *page = NULL;
4647 struct page_cgroup *pc;
4649 swp_entry_t ent = { .val = 0 };
4651 if (pte_present(ptent))
4652 page = mc_handle_present_pte(vma, addr, ptent);
4653 else if (is_swap_pte(ptent))
4654 page = mc_handle_swap_pte(vma, addr, ptent, &ent);
4655 else if (pte_none(ptent) || pte_file(ptent))
4656 page = mc_handle_file_pte(vma, addr, ptent, &ent);
4658 if (!page && !ent.val)
4661 pc = lookup_page_cgroup(page);
4663 * Do only loose check w/o page_cgroup lock.
4664 * mem_cgroup_move_account() checks the pc is valid or not under
4667 if (PageCgroupUsed(pc) && pc->mem_cgroup == mc.from) {
4668 ret = MC_TARGET_PAGE;
4670 target->page = page;
4672 if (!ret || !target)
4675 /* There is a swap entry and a page doesn't exist or isn't charged */
4676 if (ent.val && !ret &&
4677 css_id(&mc.from->css) == lookup_swap_cgroup(ent)) {
4678 ret = MC_TARGET_SWAP;
4685 static int mem_cgroup_count_precharge_pte_range(pmd_t *pmd,
4686 unsigned long addr, unsigned long end,
4687 struct mm_walk *walk)
4689 struct vm_area_struct *vma = walk->private;
4693 VM_BUG_ON(pmd_trans_huge(*pmd));
4694 pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl);
4695 for (; addr != end; pte++, addr += PAGE_SIZE)
4696 if (is_target_pte_for_mc(vma, addr, *pte, NULL))
4697 mc.precharge++; /* increment precharge temporarily */
4698 pte_unmap_unlock(pte - 1, ptl);
4704 static unsigned long mem_cgroup_count_precharge(struct mm_struct *mm)
4706 unsigned long precharge;
4707 struct vm_area_struct *vma;
4709 down_read(&mm->mmap_sem);
4710 for (vma = mm->mmap; vma; vma = vma->vm_next) {
4711 struct mm_walk mem_cgroup_count_precharge_walk = {
4712 .pmd_entry = mem_cgroup_count_precharge_pte_range,
4716 if (is_vm_hugetlb_page(vma))
4718 walk_page_range(vma->vm_start, vma->vm_end,
4719 &mem_cgroup_count_precharge_walk);
4721 up_read(&mm->mmap_sem);
4723 precharge = mc.precharge;
4729 static int mem_cgroup_precharge_mc(struct mm_struct *mm)
4731 unsigned long precharge = mem_cgroup_count_precharge(mm);
4733 VM_BUG_ON(mc.moving_task);
4734 mc.moving_task = current;
4735 return mem_cgroup_do_precharge(precharge);
4738 /* cancels all extra charges on mc.from and mc.to, and wakes up all waiters. */
4739 static void __mem_cgroup_clear_mc(void)
4741 struct mem_cgroup *from = mc.from;
4742 struct mem_cgroup *to = mc.to;
4744 /* we must uncharge all the leftover precharges from mc.to */
4746 __mem_cgroup_cancel_charge(mc.to, mc.precharge);
4750 * we didn't uncharge from mc.from at mem_cgroup_move_account(), so
4751 * we must uncharge here.
4753 if (mc.moved_charge) {
4754 __mem_cgroup_cancel_charge(mc.from, mc.moved_charge);
4755 mc.moved_charge = 0;
4757 /* we must fixup refcnts and charges */
4758 if (mc.moved_swap) {
4759 /* uncharge swap account from the old cgroup */
4760 if (!mem_cgroup_is_root(mc.from))
4761 res_counter_uncharge(&mc.from->memsw,
4762 PAGE_SIZE * mc.moved_swap);
4763 __mem_cgroup_put(mc.from, mc.moved_swap);
4765 if (!mem_cgroup_is_root(mc.to)) {
4767 * we charged both to->res and to->memsw, so we should
4770 res_counter_uncharge(&mc.to->res,
4771 PAGE_SIZE * mc.moved_swap);
4773 /* we've already done mem_cgroup_get(mc.to) */
4776 memcg_oom_recover(from);
4777 memcg_oom_recover(to);
4778 wake_up_all(&mc.waitq);
4781 static void mem_cgroup_clear_mc(void)
4783 struct mem_cgroup *from = mc.from;
4786 * we must clear moving_task before waking up waiters at the end of
4789 mc.moving_task = NULL;
4790 __mem_cgroup_clear_mc();
4791 spin_lock(&mc.lock);
4794 spin_unlock(&mc.lock);
4795 mem_cgroup_end_move(from);
4798 static int mem_cgroup_can_attach(struct cgroup_subsys *ss,
4799 struct cgroup *cgroup,
4800 struct task_struct *p,
4804 struct mem_cgroup *mem = mem_cgroup_from_cont(cgroup);
4806 if (mem->move_charge_at_immigrate) {
4807 struct mm_struct *mm;
4808 struct mem_cgroup *from = mem_cgroup_from_task(p);
4810 VM_BUG_ON(from == mem);
4812 mm = get_task_mm(p);
4815 /* We move charges only when we move a owner of the mm */
4816 if (mm->owner == p) {
4819 VM_BUG_ON(mc.precharge);
4820 VM_BUG_ON(mc.moved_charge);
4821 VM_BUG_ON(mc.moved_swap);
4822 mem_cgroup_start_move(from);
4823 spin_lock(&mc.lock);
4826 spin_unlock(&mc.lock);
4827 /* We set mc.moving_task later */
4829 ret = mem_cgroup_precharge_mc(mm);
4831 mem_cgroup_clear_mc();
4838 static void mem_cgroup_cancel_attach(struct cgroup_subsys *ss,
4839 struct cgroup *cgroup,
4840 struct task_struct *p,
4843 mem_cgroup_clear_mc();
4846 static int mem_cgroup_move_charge_pte_range(pmd_t *pmd,
4847 unsigned long addr, unsigned long end,
4848 struct mm_walk *walk)
4851 struct vm_area_struct *vma = walk->private;
4856 VM_BUG_ON(pmd_trans_huge(*pmd));
4857 pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl);
4858 for (; addr != end; addr += PAGE_SIZE) {
4859 pte_t ptent = *(pte++);
4860 union mc_target target;
4863 struct page_cgroup *pc;
4869 type = is_target_pte_for_mc(vma, addr, ptent, &target);
4871 case MC_TARGET_PAGE:
4873 if (isolate_lru_page(page))
4875 pc = lookup_page_cgroup(page);
4876 if (!mem_cgroup_move_account(pc,
4877 mc.from, mc.to, false, PAGE_SIZE)) {
4879 /* we uncharge from mc.from later. */
4882 putback_lru_page(page);
4883 put: /* is_target_pte_for_mc() gets the page */
4886 case MC_TARGET_SWAP:
4888 if (!mem_cgroup_move_swap_account(ent,
4889 mc.from, mc.to, false)) {
4891 /* we fixup refcnts and charges later. */
4899 pte_unmap_unlock(pte - 1, ptl);
4904 * We have consumed all precharges we got in can_attach().
4905 * We try charge one by one, but don't do any additional
4906 * charges to mc.to if we have failed in charge once in attach()
4909 ret = mem_cgroup_do_precharge(1);
4917 static void mem_cgroup_move_charge(struct mm_struct *mm)
4919 struct vm_area_struct *vma;
4921 lru_add_drain_all();
4923 if (unlikely(!down_read_trylock(&mm->mmap_sem))) {
4925 * Someone who are holding the mmap_sem might be waiting in
4926 * waitq. So we cancel all extra charges, wake up all waiters,
4927 * and retry. Because we cancel precharges, we might not be able
4928 * to move enough charges, but moving charge is a best-effort
4929 * feature anyway, so it wouldn't be a big problem.
4931 __mem_cgroup_clear_mc();
4935 for (vma = mm->mmap; vma; vma = vma->vm_next) {
4937 struct mm_walk mem_cgroup_move_charge_walk = {
4938 .pmd_entry = mem_cgroup_move_charge_pte_range,
4942 if (is_vm_hugetlb_page(vma))
4944 ret = walk_page_range(vma->vm_start, vma->vm_end,
4945 &mem_cgroup_move_charge_walk);
4948 * means we have consumed all precharges and failed in
4949 * doing additional charge. Just abandon here.
4953 up_read(&mm->mmap_sem);
4956 static void mem_cgroup_move_task(struct cgroup_subsys *ss,
4957 struct cgroup *cont,
4958 struct cgroup *old_cont,
4959 struct task_struct *p,
4962 struct mm_struct *mm;
4965 /* no need to move charge */
4968 mm = get_task_mm(p);
4970 mem_cgroup_move_charge(mm);
4973 mem_cgroup_clear_mc();
4975 #else /* !CONFIG_MMU */
4976 static int mem_cgroup_can_attach(struct cgroup_subsys *ss,
4977 struct cgroup *cgroup,
4978 struct task_struct *p,
4983 static void mem_cgroup_cancel_attach(struct cgroup_subsys *ss,
4984 struct cgroup *cgroup,
4985 struct task_struct *p,
4989 static void mem_cgroup_move_task(struct cgroup_subsys *ss,
4990 struct cgroup *cont,
4991 struct cgroup *old_cont,
4992 struct task_struct *p,
4998 struct cgroup_subsys mem_cgroup_subsys = {
5000 .subsys_id = mem_cgroup_subsys_id,
5001 .create = mem_cgroup_create,
5002 .pre_destroy = mem_cgroup_pre_destroy,
5003 .destroy = mem_cgroup_destroy,
5004 .populate = mem_cgroup_populate,
5005 .can_attach = mem_cgroup_can_attach,
5006 .cancel_attach = mem_cgroup_cancel_attach,
5007 .attach = mem_cgroup_move_task,
5012 #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP
5013 static int __init enable_swap_account(char *s)
5015 /* consider enabled if no parameter or 1 is given */
5016 if (!s || !strcmp(s, "1"))
5017 really_do_swap_account = 1;
5018 else if (!strcmp(s, "0"))
5019 really_do_swap_account = 0;
5022 __setup("swapaccount", enable_swap_account);
5024 static int __init disable_swap_account(char *s)
5026 enable_swap_account("0");
5029 __setup("noswapaccount", disable_swap_account);