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 struct mm_struct *mm;
296 wait_queue_head_t waitq; /* a waitq for other context */
298 .lock = __SPIN_LOCK_UNLOCKED(mc.lock),
299 .waitq = __WAIT_QUEUE_HEAD_INITIALIZER(mc.waitq),
302 static bool move_anon(void)
304 return test_bit(MOVE_CHARGE_TYPE_ANON,
305 &mc.to->move_charge_at_immigrate);
308 static bool move_file(void)
310 return test_bit(MOVE_CHARGE_TYPE_FILE,
311 &mc.to->move_charge_at_immigrate);
315 * Maximum loops in mem_cgroup_hierarchical_reclaim(), used for soft
316 * limit reclaim to prevent infinite loops, if they ever occur.
318 #define MEM_CGROUP_MAX_RECLAIM_LOOPS (100)
319 #define MEM_CGROUP_MAX_SOFT_LIMIT_RECLAIM_LOOPS (2)
322 MEM_CGROUP_CHARGE_TYPE_CACHE = 0,
323 MEM_CGROUP_CHARGE_TYPE_MAPPED,
324 MEM_CGROUP_CHARGE_TYPE_SHMEM, /* used by page migration of shmem */
325 MEM_CGROUP_CHARGE_TYPE_FORCE, /* used by force_empty */
326 MEM_CGROUP_CHARGE_TYPE_SWAPOUT, /* for accounting swapcache */
327 MEM_CGROUP_CHARGE_TYPE_DROP, /* a page was unused swap cache */
331 /* only for here (for easy reading.) */
332 #define PCGF_CACHE (1UL << PCG_CACHE)
333 #define PCGF_USED (1UL << PCG_USED)
334 #define PCGF_LOCK (1UL << PCG_LOCK)
335 /* Not used, but added here for completeness */
336 #define PCGF_ACCT (1UL << PCG_ACCT)
338 /* for encoding cft->private value on file */
341 #define _OOM_TYPE (2)
342 #define MEMFILE_PRIVATE(x, val) (((x) << 16) | (val))
343 #define MEMFILE_TYPE(val) (((val) >> 16) & 0xffff)
344 #define MEMFILE_ATTR(val) ((val) & 0xffff)
345 /* Used for OOM nofiier */
346 #define OOM_CONTROL (0)
349 * Reclaim flags for mem_cgroup_hierarchical_reclaim
351 #define MEM_CGROUP_RECLAIM_NOSWAP_BIT 0x0
352 #define MEM_CGROUP_RECLAIM_NOSWAP (1 << MEM_CGROUP_RECLAIM_NOSWAP_BIT)
353 #define MEM_CGROUP_RECLAIM_SHRINK_BIT 0x1
354 #define MEM_CGROUP_RECLAIM_SHRINK (1 << MEM_CGROUP_RECLAIM_SHRINK_BIT)
355 #define MEM_CGROUP_RECLAIM_SOFT_BIT 0x2
356 #define MEM_CGROUP_RECLAIM_SOFT (1 << MEM_CGROUP_RECLAIM_SOFT_BIT)
358 static void mem_cgroup_get(struct mem_cgroup *mem);
359 static void mem_cgroup_put(struct mem_cgroup *mem);
360 static struct mem_cgroup *parent_mem_cgroup(struct mem_cgroup *mem);
361 static void drain_all_stock_async(void);
363 static struct mem_cgroup_per_zone *
364 mem_cgroup_zoneinfo(struct mem_cgroup *mem, int nid, int zid)
366 return &mem->info.nodeinfo[nid]->zoneinfo[zid];
369 struct cgroup_subsys_state *mem_cgroup_css(struct mem_cgroup *mem)
374 static struct mem_cgroup_per_zone *
375 page_cgroup_zoneinfo(struct page_cgroup *pc)
377 struct mem_cgroup *mem = pc->mem_cgroup;
378 int nid = page_cgroup_nid(pc);
379 int zid = page_cgroup_zid(pc);
384 return mem_cgroup_zoneinfo(mem, nid, zid);
387 static struct mem_cgroup_tree_per_zone *
388 soft_limit_tree_node_zone(int nid, int zid)
390 return &soft_limit_tree.rb_tree_per_node[nid]->rb_tree_per_zone[zid];
393 static struct mem_cgroup_tree_per_zone *
394 soft_limit_tree_from_page(struct page *page)
396 int nid = page_to_nid(page);
397 int zid = page_zonenum(page);
399 return &soft_limit_tree.rb_tree_per_node[nid]->rb_tree_per_zone[zid];
403 __mem_cgroup_insert_exceeded(struct mem_cgroup *mem,
404 struct mem_cgroup_per_zone *mz,
405 struct mem_cgroup_tree_per_zone *mctz,
406 unsigned long long new_usage_in_excess)
408 struct rb_node **p = &mctz->rb_root.rb_node;
409 struct rb_node *parent = NULL;
410 struct mem_cgroup_per_zone *mz_node;
415 mz->usage_in_excess = new_usage_in_excess;
416 if (!mz->usage_in_excess)
420 mz_node = rb_entry(parent, struct mem_cgroup_per_zone,
422 if (mz->usage_in_excess < mz_node->usage_in_excess)
425 * We can't avoid mem cgroups that are over their soft
426 * limit by the same amount
428 else if (mz->usage_in_excess >= mz_node->usage_in_excess)
431 rb_link_node(&mz->tree_node, parent, p);
432 rb_insert_color(&mz->tree_node, &mctz->rb_root);
437 __mem_cgroup_remove_exceeded(struct mem_cgroup *mem,
438 struct mem_cgroup_per_zone *mz,
439 struct mem_cgroup_tree_per_zone *mctz)
443 rb_erase(&mz->tree_node, &mctz->rb_root);
448 mem_cgroup_remove_exceeded(struct mem_cgroup *mem,
449 struct mem_cgroup_per_zone *mz,
450 struct mem_cgroup_tree_per_zone *mctz)
452 spin_lock(&mctz->lock);
453 __mem_cgroup_remove_exceeded(mem, mz, mctz);
454 spin_unlock(&mctz->lock);
458 static void mem_cgroup_update_tree(struct mem_cgroup *mem, struct page *page)
460 unsigned long long excess;
461 struct mem_cgroup_per_zone *mz;
462 struct mem_cgroup_tree_per_zone *mctz;
463 int nid = page_to_nid(page);
464 int zid = page_zonenum(page);
465 mctz = soft_limit_tree_from_page(page);
468 * Necessary to update all ancestors when hierarchy is used.
469 * because their event counter is not touched.
471 for (; mem; mem = parent_mem_cgroup(mem)) {
472 mz = mem_cgroup_zoneinfo(mem, nid, zid);
473 excess = res_counter_soft_limit_excess(&mem->res);
475 * We have to update the tree if mz is on RB-tree or
476 * mem is over its softlimit.
478 if (excess || mz->on_tree) {
479 spin_lock(&mctz->lock);
480 /* if on-tree, remove it */
482 __mem_cgroup_remove_exceeded(mem, mz, mctz);
484 * Insert again. mz->usage_in_excess will be updated.
485 * If excess is 0, no tree ops.
487 __mem_cgroup_insert_exceeded(mem, mz, mctz, excess);
488 spin_unlock(&mctz->lock);
493 static void mem_cgroup_remove_from_trees(struct mem_cgroup *mem)
496 struct mem_cgroup_per_zone *mz;
497 struct mem_cgroup_tree_per_zone *mctz;
499 for_each_node_state(node, N_POSSIBLE) {
500 for (zone = 0; zone < MAX_NR_ZONES; zone++) {
501 mz = mem_cgroup_zoneinfo(mem, node, zone);
502 mctz = soft_limit_tree_node_zone(node, zone);
503 mem_cgroup_remove_exceeded(mem, mz, mctz);
508 static inline unsigned long mem_cgroup_get_excess(struct mem_cgroup *mem)
510 return res_counter_soft_limit_excess(&mem->res) >> PAGE_SHIFT;
513 static struct mem_cgroup_per_zone *
514 __mem_cgroup_largest_soft_limit_node(struct mem_cgroup_tree_per_zone *mctz)
516 struct rb_node *rightmost = NULL;
517 struct mem_cgroup_per_zone *mz;
521 rightmost = rb_last(&mctz->rb_root);
523 goto done; /* Nothing to reclaim from */
525 mz = rb_entry(rightmost, struct mem_cgroup_per_zone, tree_node);
527 * Remove the node now but someone else can add it back,
528 * we will to add it back at the end of reclaim to its correct
529 * position in the tree.
531 __mem_cgroup_remove_exceeded(mz->mem, mz, mctz);
532 if (!res_counter_soft_limit_excess(&mz->mem->res) ||
533 !css_tryget(&mz->mem->css))
539 static struct mem_cgroup_per_zone *
540 mem_cgroup_largest_soft_limit_node(struct mem_cgroup_tree_per_zone *mctz)
542 struct mem_cgroup_per_zone *mz;
544 spin_lock(&mctz->lock);
545 mz = __mem_cgroup_largest_soft_limit_node(mctz);
546 spin_unlock(&mctz->lock);
551 * Implementation Note: reading percpu statistics for memcg.
553 * Both of vmstat[] and percpu_counter has threshold and do periodic
554 * synchronization to implement "quick" read. There are trade-off between
555 * reading cost and precision of value. Then, we may have a chance to implement
556 * a periodic synchronizion of counter in memcg's counter.
558 * But this _read() function is used for user interface now. The user accounts
559 * memory usage by memory cgroup and he _always_ requires exact value because
560 * he accounts memory. Even if we provide quick-and-fuzzy read, we always
561 * have to visit all online cpus and make sum. So, for now, unnecessary
562 * synchronization is not implemented. (just implemented for cpu hotplug)
564 * If there are kernel internal actions which can make use of some not-exact
565 * value, and reading all cpu value can be performance bottleneck in some
566 * common workload, threashold and synchonization as vmstat[] should be
569 static s64 mem_cgroup_read_stat(struct mem_cgroup *mem,
570 enum mem_cgroup_stat_index idx)
576 for_each_online_cpu(cpu)
577 val += per_cpu(mem->stat->count[idx], cpu);
578 #ifdef CONFIG_HOTPLUG_CPU
579 spin_lock(&mem->pcp_counter_lock);
580 val += mem->nocpu_base.count[idx];
581 spin_unlock(&mem->pcp_counter_lock);
587 static s64 mem_cgroup_local_usage(struct mem_cgroup *mem)
591 ret = mem_cgroup_read_stat(mem, MEM_CGROUP_STAT_RSS);
592 ret += mem_cgroup_read_stat(mem, MEM_CGROUP_STAT_CACHE);
596 static void mem_cgroup_swap_statistics(struct mem_cgroup *mem,
599 int val = (charge) ? 1 : -1;
600 this_cpu_add(mem->stat->count[MEM_CGROUP_STAT_SWAPOUT], val);
603 static void mem_cgroup_charge_statistics(struct mem_cgroup *mem,
604 struct page_cgroup *pc,
607 int val = (charge) ? 1 : -1;
611 if (PageCgroupCache(pc))
612 __this_cpu_add(mem->stat->count[MEM_CGROUP_STAT_CACHE], val);
614 __this_cpu_add(mem->stat->count[MEM_CGROUP_STAT_RSS], val);
617 __this_cpu_inc(mem->stat->count[MEM_CGROUP_STAT_PGPGIN_COUNT]);
619 __this_cpu_inc(mem->stat->count[MEM_CGROUP_STAT_PGPGOUT_COUNT]);
620 __this_cpu_inc(mem->stat->count[MEM_CGROUP_EVENTS]);
625 static unsigned long mem_cgroup_get_local_zonestat(struct mem_cgroup *mem,
629 struct mem_cgroup_per_zone *mz;
632 for_each_online_node(nid)
633 for (zid = 0; zid < MAX_NR_ZONES; zid++) {
634 mz = mem_cgroup_zoneinfo(mem, nid, zid);
635 total += MEM_CGROUP_ZSTAT(mz, idx);
640 static bool __memcg_event_check(struct mem_cgroup *mem, int event_mask_shift)
644 val = this_cpu_read(mem->stat->count[MEM_CGROUP_EVENTS]);
646 return !(val & ((1 << event_mask_shift) - 1));
650 * Check events in order.
653 static void memcg_check_events(struct mem_cgroup *mem, struct page *page)
655 /* threshold event is triggered in finer grain than soft limit */
656 if (unlikely(__memcg_event_check(mem, THRESHOLDS_EVENTS_THRESH))) {
657 mem_cgroup_threshold(mem);
658 if (unlikely(__memcg_event_check(mem, SOFTLIMIT_EVENTS_THRESH)))
659 mem_cgroup_update_tree(mem, page);
663 static struct mem_cgroup *mem_cgroup_from_cont(struct cgroup *cont)
665 return container_of(cgroup_subsys_state(cont,
666 mem_cgroup_subsys_id), struct mem_cgroup,
670 struct mem_cgroup *mem_cgroup_from_task(struct task_struct *p)
673 * mm_update_next_owner() may clear mm->owner to NULL
674 * if it races with swapoff, page migration, etc.
675 * So this can be called with p == NULL.
680 return container_of(task_subsys_state(p, mem_cgroup_subsys_id),
681 struct mem_cgroup, css);
684 static struct mem_cgroup *try_get_mem_cgroup_from_mm(struct mm_struct *mm)
686 struct mem_cgroup *mem = NULL;
691 * Because we have no locks, mm->owner's may be being moved to other
692 * cgroup. We use css_tryget() here even if this looks
693 * pessimistic (rather than adding locks here).
697 mem = mem_cgroup_from_task(rcu_dereference(mm->owner));
700 } while (!css_tryget(&mem->css));
705 /* The caller has to guarantee "mem" exists before calling this */
706 static struct mem_cgroup *mem_cgroup_start_loop(struct mem_cgroup *mem)
708 struct cgroup_subsys_state *css;
711 if (!mem) /* ROOT cgroup has the smallest ID */
712 return root_mem_cgroup; /*css_put/get against root is ignored*/
713 if (!mem->use_hierarchy) {
714 if (css_tryget(&mem->css))
720 * searching a memory cgroup which has the smallest ID under given
721 * ROOT cgroup. (ID >= 1)
723 css = css_get_next(&mem_cgroup_subsys, 1, &mem->css, &found);
724 if (css && css_tryget(css))
725 mem = container_of(css, struct mem_cgroup, css);
732 static struct mem_cgroup *mem_cgroup_get_next(struct mem_cgroup *iter,
733 struct mem_cgroup *root,
736 int nextid = css_id(&iter->css) + 1;
739 struct cgroup_subsys_state *css;
741 hierarchy_used = iter->use_hierarchy;
744 /* If no ROOT, walk all, ignore hierarchy */
745 if (!cond || (root && !hierarchy_used))
749 root = root_mem_cgroup;
755 css = css_get_next(&mem_cgroup_subsys, nextid,
757 if (css && css_tryget(css))
758 iter = container_of(css, struct mem_cgroup, css);
760 /* If css is NULL, no more cgroups will be found */
762 } while (css && !iter);
767 * for_eacn_mem_cgroup_tree() for visiting all cgroup under tree. Please
768 * be careful that "break" loop is not allowed. We have reference count.
769 * Instead of that modify "cond" to be false and "continue" to exit the loop.
771 #define for_each_mem_cgroup_tree_cond(iter, root, cond) \
772 for (iter = mem_cgroup_start_loop(root);\
774 iter = mem_cgroup_get_next(iter, root, cond))
776 #define for_each_mem_cgroup_tree(iter, root) \
777 for_each_mem_cgroup_tree_cond(iter, root, true)
779 #define for_each_mem_cgroup_all(iter) \
780 for_each_mem_cgroup_tree_cond(iter, NULL, true)
783 static inline bool mem_cgroup_is_root(struct mem_cgroup *mem)
785 return (mem == root_mem_cgroup);
789 * Following LRU functions are allowed to be used without PCG_LOCK.
790 * Operations are called by routine of global LRU independently from memcg.
791 * What we have to take care of here is validness of pc->mem_cgroup.
793 * Changes to pc->mem_cgroup happens when
796 * In typical case, "charge" is done before add-to-lru. Exception is SwapCache.
797 * It is added to LRU before charge.
798 * If PCG_USED bit is not set, page_cgroup is not added to this private LRU.
799 * When moving account, the page is not on LRU. It's isolated.
802 void mem_cgroup_del_lru_list(struct page *page, enum lru_list lru)
804 struct page_cgroup *pc;
805 struct mem_cgroup_per_zone *mz;
807 if (mem_cgroup_disabled())
809 pc = lookup_page_cgroup(page);
810 /* can happen while we handle swapcache. */
811 if (!TestClearPageCgroupAcctLRU(pc))
813 VM_BUG_ON(!pc->mem_cgroup);
815 * We don't check PCG_USED bit. It's cleared when the "page" is finally
816 * removed from global LRU.
818 mz = page_cgroup_zoneinfo(pc);
819 MEM_CGROUP_ZSTAT(mz, lru) -= 1;
820 if (mem_cgroup_is_root(pc->mem_cgroup))
822 VM_BUG_ON(list_empty(&pc->lru));
823 list_del_init(&pc->lru);
827 void mem_cgroup_del_lru(struct page *page)
829 mem_cgroup_del_lru_list(page, page_lru(page));
832 void mem_cgroup_rotate_lru_list(struct page *page, enum lru_list lru)
834 struct mem_cgroup_per_zone *mz;
835 struct page_cgroup *pc;
837 if (mem_cgroup_disabled())
840 pc = lookup_page_cgroup(page);
842 * Used bit is set without atomic ops but after smp_wmb().
843 * For making pc->mem_cgroup visible, insert smp_rmb() here.
846 /* unused or root page is not rotated. */
847 if (!PageCgroupUsed(pc) || mem_cgroup_is_root(pc->mem_cgroup))
849 mz = page_cgroup_zoneinfo(pc);
850 list_move(&pc->lru, &mz->lists[lru]);
853 void mem_cgroup_add_lru_list(struct page *page, enum lru_list lru)
855 struct page_cgroup *pc;
856 struct mem_cgroup_per_zone *mz;
858 if (mem_cgroup_disabled())
860 pc = lookup_page_cgroup(page);
861 VM_BUG_ON(PageCgroupAcctLRU(pc));
863 * Used bit is set without atomic ops but after smp_wmb().
864 * For making pc->mem_cgroup visible, insert smp_rmb() here.
867 if (!PageCgroupUsed(pc))
870 mz = page_cgroup_zoneinfo(pc);
871 MEM_CGROUP_ZSTAT(mz, lru) += 1;
872 SetPageCgroupAcctLRU(pc);
873 if (mem_cgroup_is_root(pc->mem_cgroup))
875 list_add(&pc->lru, &mz->lists[lru]);
879 * At handling SwapCache, pc->mem_cgroup may be changed while it's linked to
880 * lru because the page may.be reused after it's fully uncharged (because of
881 * SwapCache behavior).To handle that, unlink page_cgroup from LRU when charge
882 * it again. This function is only used to charge SwapCache. It's done under
883 * lock_page and expected that zone->lru_lock is never held.
885 static void mem_cgroup_lru_del_before_commit_swapcache(struct page *page)
888 struct zone *zone = page_zone(page);
889 struct page_cgroup *pc = lookup_page_cgroup(page);
891 spin_lock_irqsave(&zone->lru_lock, flags);
893 * Forget old LRU when this page_cgroup is *not* used. This Used bit
894 * is guarded by lock_page() because the page is SwapCache.
896 if (!PageCgroupUsed(pc))
897 mem_cgroup_del_lru_list(page, page_lru(page));
898 spin_unlock_irqrestore(&zone->lru_lock, flags);
901 static void mem_cgroup_lru_add_after_commit_swapcache(struct page *page)
904 struct zone *zone = page_zone(page);
905 struct page_cgroup *pc = lookup_page_cgroup(page);
907 spin_lock_irqsave(&zone->lru_lock, flags);
908 /* link when the page is linked to LRU but page_cgroup isn't */
909 if (PageLRU(page) && !PageCgroupAcctLRU(pc))
910 mem_cgroup_add_lru_list(page, page_lru(page));
911 spin_unlock_irqrestore(&zone->lru_lock, flags);
915 void mem_cgroup_move_lists(struct page *page,
916 enum lru_list from, enum lru_list to)
918 if (mem_cgroup_disabled())
920 mem_cgroup_del_lru_list(page, from);
921 mem_cgroup_add_lru_list(page, to);
924 int task_in_mem_cgroup(struct task_struct *task, const struct mem_cgroup *mem)
927 struct mem_cgroup *curr = NULL;
928 struct task_struct *p;
930 p = find_lock_task_mm(task);
933 curr = try_get_mem_cgroup_from_mm(p->mm);
938 * We should check use_hierarchy of "mem" not "curr". Because checking
939 * use_hierarchy of "curr" here make this function true if hierarchy is
940 * enabled in "curr" and "curr" is a child of "mem" in *cgroup*
941 * hierarchy(even if use_hierarchy is disabled in "mem").
943 if (mem->use_hierarchy)
944 ret = css_is_ancestor(&curr->css, &mem->css);
951 static int calc_inactive_ratio(struct mem_cgroup *memcg, unsigned long *present_pages)
953 unsigned long active;
954 unsigned long inactive;
956 unsigned long inactive_ratio;
958 inactive = mem_cgroup_get_local_zonestat(memcg, LRU_INACTIVE_ANON);
959 active = mem_cgroup_get_local_zonestat(memcg, LRU_ACTIVE_ANON);
961 gb = (inactive + active) >> (30 - PAGE_SHIFT);
963 inactive_ratio = int_sqrt(10 * gb);
968 present_pages[0] = inactive;
969 present_pages[1] = active;
972 return inactive_ratio;
975 int mem_cgroup_inactive_anon_is_low(struct mem_cgroup *memcg)
977 unsigned long active;
978 unsigned long inactive;
979 unsigned long present_pages[2];
980 unsigned long inactive_ratio;
982 inactive_ratio = calc_inactive_ratio(memcg, present_pages);
984 inactive = present_pages[0];
985 active = present_pages[1];
987 if (inactive * inactive_ratio < active)
993 int mem_cgroup_inactive_file_is_low(struct mem_cgroup *memcg)
995 unsigned long active;
996 unsigned long inactive;
998 inactive = mem_cgroup_get_local_zonestat(memcg, LRU_INACTIVE_FILE);
999 active = mem_cgroup_get_local_zonestat(memcg, LRU_ACTIVE_FILE);
1001 return (active > inactive);
1004 unsigned long mem_cgroup_zone_nr_pages(struct mem_cgroup *memcg,
1008 int nid = zone_to_nid(zone);
1009 int zid = zone_idx(zone);
1010 struct mem_cgroup_per_zone *mz = mem_cgroup_zoneinfo(memcg, nid, zid);
1012 return MEM_CGROUP_ZSTAT(mz, lru);
1015 struct zone_reclaim_stat *mem_cgroup_get_reclaim_stat(struct mem_cgroup *memcg,
1018 int nid = zone_to_nid(zone);
1019 int zid = zone_idx(zone);
1020 struct mem_cgroup_per_zone *mz = mem_cgroup_zoneinfo(memcg, nid, zid);
1022 return &mz->reclaim_stat;
1025 struct zone_reclaim_stat *
1026 mem_cgroup_get_reclaim_stat_from_page(struct page *page)
1028 struct page_cgroup *pc;
1029 struct mem_cgroup_per_zone *mz;
1030 int page_size = PAGE_SIZE;
1032 if (PageTransHuge(page))
1033 page_size <<= compound_order(page);
1035 if (mem_cgroup_disabled())
1038 pc = lookup_page_cgroup(page);
1040 * Used bit is set without atomic ops but after smp_wmb().
1041 * For making pc->mem_cgroup visible, insert smp_rmb() here.
1044 if (!PageCgroupUsed(pc))
1047 mz = page_cgroup_zoneinfo(pc);
1051 return &mz->reclaim_stat;
1054 unsigned long mem_cgroup_isolate_pages(unsigned long nr_to_scan,
1055 struct list_head *dst,
1056 unsigned long *scanned, int order,
1057 int mode, struct zone *z,
1058 struct mem_cgroup *mem_cont,
1059 int active, int file)
1061 unsigned long nr_taken = 0;
1065 struct list_head *src;
1066 struct page_cgroup *pc, *tmp;
1067 int nid = zone_to_nid(z);
1068 int zid = zone_idx(z);
1069 struct mem_cgroup_per_zone *mz;
1070 int lru = LRU_FILE * file + active;
1074 mz = mem_cgroup_zoneinfo(mem_cont, nid, zid);
1075 src = &mz->lists[lru];
1078 list_for_each_entry_safe_reverse(pc, tmp, src, lru) {
1079 if (scan >= nr_to_scan)
1083 if (unlikely(!PageCgroupUsed(pc)))
1085 if (unlikely(!PageLRU(page)))
1089 ret = __isolate_lru_page(page, mode, file);
1092 list_move(&page->lru, dst);
1093 mem_cgroup_del_lru(page);
1094 nr_taken += hpage_nr_pages(page);
1097 /* we don't affect global LRU but rotate in our LRU */
1098 mem_cgroup_rotate_lru_list(page, page_lru(page));
1107 trace_mm_vmscan_memcg_isolate(0, nr_to_scan, scan, nr_taken,
1113 #define mem_cgroup_from_res_counter(counter, member) \
1114 container_of(counter, struct mem_cgroup, member)
1116 static bool mem_cgroup_check_under_limit(struct mem_cgroup *mem)
1118 if (do_swap_account) {
1119 if (res_counter_check_under_limit(&mem->res) &&
1120 res_counter_check_under_limit(&mem->memsw))
1123 if (res_counter_check_under_limit(&mem->res))
1128 static unsigned int get_swappiness(struct mem_cgroup *memcg)
1130 struct cgroup *cgrp = memcg->css.cgroup;
1131 unsigned int swappiness;
1134 if (cgrp->parent == NULL)
1135 return vm_swappiness;
1137 spin_lock(&memcg->reclaim_param_lock);
1138 swappiness = memcg->swappiness;
1139 spin_unlock(&memcg->reclaim_param_lock);
1144 static void mem_cgroup_start_move(struct mem_cgroup *mem)
1149 spin_lock(&mem->pcp_counter_lock);
1150 for_each_online_cpu(cpu)
1151 per_cpu(mem->stat->count[MEM_CGROUP_ON_MOVE], cpu) += 1;
1152 mem->nocpu_base.count[MEM_CGROUP_ON_MOVE] += 1;
1153 spin_unlock(&mem->pcp_counter_lock);
1159 static void mem_cgroup_end_move(struct mem_cgroup *mem)
1166 spin_lock(&mem->pcp_counter_lock);
1167 for_each_online_cpu(cpu)
1168 per_cpu(mem->stat->count[MEM_CGROUP_ON_MOVE], cpu) -= 1;
1169 mem->nocpu_base.count[MEM_CGROUP_ON_MOVE] -= 1;
1170 spin_unlock(&mem->pcp_counter_lock);
1174 * 2 routines for checking "mem" is under move_account() or not.
1176 * mem_cgroup_stealed() - checking a cgroup is mc.from or not. This is used
1177 * for avoiding race in accounting. If true,
1178 * pc->mem_cgroup may be overwritten.
1180 * mem_cgroup_under_move() - checking a cgroup is mc.from or mc.to or
1181 * under hierarchy of moving cgroups. This is for
1182 * waiting at hith-memory prressure caused by "move".
1185 static bool mem_cgroup_stealed(struct mem_cgroup *mem)
1187 VM_BUG_ON(!rcu_read_lock_held());
1188 return this_cpu_read(mem->stat->count[MEM_CGROUP_ON_MOVE]) > 0;
1191 static bool mem_cgroup_under_move(struct mem_cgroup *mem)
1193 struct mem_cgroup *from;
1194 struct mem_cgroup *to;
1197 * Unlike task_move routines, we access mc.to, mc.from not under
1198 * mutual exclusion by cgroup_mutex. Here, we take spinlock instead.
1200 spin_lock(&mc.lock);
1205 if (from == mem || to == mem
1206 || (mem->use_hierarchy && css_is_ancestor(&from->css, &mem->css))
1207 || (mem->use_hierarchy && css_is_ancestor(&to->css, &mem->css)))
1210 spin_unlock(&mc.lock);
1214 static bool mem_cgroup_wait_acct_move(struct mem_cgroup *mem)
1216 if (mc.moving_task && current != mc.moving_task) {
1217 if (mem_cgroup_under_move(mem)) {
1219 prepare_to_wait(&mc.waitq, &wait, TASK_INTERRUPTIBLE);
1220 /* moving charge context might have finished. */
1223 finish_wait(&mc.waitq, &wait);
1231 * mem_cgroup_print_oom_info: Called from OOM with tasklist_lock held in read mode.
1232 * @memcg: The memory cgroup that went over limit
1233 * @p: Task that is going to be killed
1235 * NOTE: @memcg and @p's mem_cgroup can be different when hierarchy is
1238 void mem_cgroup_print_oom_info(struct mem_cgroup *memcg, struct task_struct *p)
1240 struct cgroup *task_cgrp;
1241 struct cgroup *mem_cgrp;
1243 * Need a buffer in BSS, can't rely on allocations. The code relies
1244 * on the assumption that OOM is serialized for memory controller.
1245 * If this assumption is broken, revisit this code.
1247 static char memcg_name[PATH_MAX];
1256 mem_cgrp = memcg->css.cgroup;
1257 task_cgrp = task_cgroup(p, mem_cgroup_subsys_id);
1259 ret = cgroup_path(task_cgrp, memcg_name, PATH_MAX);
1262 * Unfortunately, we are unable to convert to a useful name
1263 * But we'll still print out the usage information
1270 printk(KERN_INFO "Task in %s killed", memcg_name);
1273 ret = cgroup_path(mem_cgrp, memcg_name, PATH_MAX);
1281 * Continues from above, so we don't need an KERN_ level
1283 printk(KERN_CONT " as a result of limit of %s\n", memcg_name);
1286 printk(KERN_INFO "memory: usage %llukB, limit %llukB, failcnt %llu\n",
1287 res_counter_read_u64(&memcg->res, RES_USAGE) >> 10,
1288 res_counter_read_u64(&memcg->res, RES_LIMIT) >> 10,
1289 res_counter_read_u64(&memcg->res, RES_FAILCNT));
1290 printk(KERN_INFO "memory+swap: usage %llukB, limit %llukB, "
1292 res_counter_read_u64(&memcg->memsw, RES_USAGE) >> 10,
1293 res_counter_read_u64(&memcg->memsw, RES_LIMIT) >> 10,
1294 res_counter_read_u64(&memcg->memsw, RES_FAILCNT));
1298 * This function returns the number of memcg under hierarchy tree. Returns
1299 * 1(self count) if no children.
1301 static int mem_cgroup_count_children(struct mem_cgroup *mem)
1304 struct mem_cgroup *iter;
1306 for_each_mem_cgroup_tree(iter, mem)
1312 * Return the memory (and swap, if configured) limit for a memcg.
1314 u64 mem_cgroup_get_limit(struct mem_cgroup *memcg)
1319 limit = res_counter_read_u64(&memcg->res, RES_LIMIT) +
1321 memsw = res_counter_read_u64(&memcg->memsw, RES_LIMIT);
1323 * If memsw is finite and limits the amount of swap space available
1324 * to this memcg, return that limit.
1326 return min(limit, memsw);
1330 * Visit the first child (need not be the first child as per the ordering
1331 * of the cgroup list, since we track last_scanned_child) of @mem and use
1332 * that to reclaim free pages from.
1334 static struct mem_cgroup *
1335 mem_cgroup_select_victim(struct mem_cgroup *root_mem)
1337 struct mem_cgroup *ret = NULL;
1338 struct cgroup_subsys_state *css;
1341 if (!root_mem->use_hierarchy) {
1342 css_get(&root_mem->css);
1348 nextid = root_mem->last_scanned_child + 1;
1349 css = css_get_next(&mem_cgroup_subsys, nextid, &root_mem->css,
1351 if (css && css_tryget(css))
1352 ret = container_of(css, struct mem_cgroup, css);
1355 /* Updates scanning parameter */
1356 spin_lock(&root_mem->reclaim_param_lock);
1358 /* this means start scan from ID:1 */
1359 root_mem->last_scanned_child = 0;
1361 root_mem->last_scanned_child = found;
1362 spin_unlock(&root_mem->reclaim_param_lock);
1369 * Scan the hierarchy if needed to reclaim memory. We remember the last child
1370 * we reclaimed from, so that we don't end up penalizing one child extensively
1371 * based on its position in the children list.
1373 * root_mem is the original ancestor that we've been reclaim from.
1375 * We give up and return to the caller when we visit root_mem twice.
1376 * (other groups can be removed while we're walking....)
1378 * If shrink==true, for avoiding to free too much, this returns immedieately.
1380 static int mem_cgroup_hierarchical_reclaim(struct mem_cgroup *root_mem,
1383 unsigned long reclaim_options)
1385 struct mem_cgroup *victim;
1388 bool noswap = reclaim_options & MEM_CGROUP_RECLAIM_NOSWAP;
1389 bool shrink = reclaim_options & MEM_CGROUP_RECLAIM_SHRINK;
1390 bool check_soft = reclaim_options & MEM_CGROUP_RECLAIM_SOFT;
1391 unsigned long excess = mem_cgroup_get_excess(root_mem);
1393 /* If memsw_is_minimum==1, swap-out is of-no-use. */
1394 if (root_mem->memsw_is_minimum)
1398 victim = mem_cgroup_select_victim(root_mem);
1399 if (victim == root_mem) {
1402 drain_all_stock_async();
1405 * If we have not been able to reclaim
1406 * anything, it might because there are
1407 * no reclaimable pages under this hierarchy
1409 if (!check_soft || !total) {
1410 css_put(&victim->css);
1414 * We want to do more targetted reclaim.
1415 * excess >> 2 is not to excessive so as to
1416 * reclaim too much, nor too less that we keep
1417 * coming back to reclaim from this cgroup
1419 if (total >= (excess >> 2) ||
1420 (loop > MEM_CGROUP_MAX_RECLAIM_LOOPS)) {
1421 css_put(&victim->css);
1426 if (!mem_cgroup_local_usage(victim)) {
1427 /* this cgroup's local usage == 0 */
1428 css_put(&victim->css);
1431 /* we use swappiness of local cgroup */
1433 ret = mem_cgroup_shrink_node_zone(victim, gfp_mask,
1434 noswap, get_swappiness(victim), zone);
1436 ret = try_to_free_mem_cgroup_pages(victim, gfp_mask,
1437 noswap, get_swappiness(victim));
1438 css_put(&victim->css);
1440 * At shrinking usage, we can't check we should stop here or
1441 * reclaim more. It's depends on callers. last_scanned_child
1442 * will work enough for keeping fairness under tree.
1448 if (res_counter_check_under_soft_limit(&root_mem->res))
1450 } else if (mem_cgroup_check_under_limit(root_mem))
1457 * Check OOM-Killer is already running under our hierarchy.
1458 * If someone is running, return false.
1460 static bool mem_cgroup_oom_lock(struct mem_cgroup *mem)
1462 int x, lock_count = 0;
1463 struct mem_cgroup *iter;
1465 for_each_mem_cgroup_tree(iter, mem) {
1466 x = atomic_inc_return(&iter->oom_lock);
1467 lock_count = max(x, lock_count);
1470 if (lock_count == 1)
1475 static int mem_cgroup_oom_unlock(struct mem_cgroup *mem)
1477 struct mem_cgroup *iter;
1480 * When a new child is created while the hierarchy is under oom,
1481 * mem_cgroup_oom_lock() may not be called. We have to use
1482 * atomic_add_unless() here.
1484 for_each_mem_cgroup_tree(iter, mem)
1485 atomic_add_unless(&iter->oom_lock, -1, 0);
1490 static DEFINE_MUTEX(memcg_oom_mutex);
1491 static DECLARE_WAIT_QUEUE_HEAD(memcg_oom_waitq);
1493 struct oom_wait_info {
1494 struct mem_cgroup *mem;
1498 static int memcg_oom_wake_function(wait_queue_t *wait,
1499 unsigned mode, int sync, void *arg)
1501 struct mem_cgroup *wake_mem = (struct mem_cgroup *)arg;
1502 struct oom_wait_info *oom_wait_info;
1504 oom_wait_info = container_of(wait, struct oom_wait_info, wait);
1506 if (oom_wait_info->mem == wake_mem)
1508 /* if no hierarchy, no match */
1509 if (!oom_wait_info->mem->use_hierarchy || !wake_mem->use_hierarchy)
1512 * Both of oom_wait_info->mem and wake_mem are stable under us.
1513 * Then we can use css_is_ancestor without taking care of RCU.
1515 if (!css_is_ancestor(&oom_wait_info->mem->css, &wake_mem->css) &&
1516 !css_is_ancestor(&wake_mem->css, &oom_wait_info->mem->css))
1520 return autoremove_wake_function(wait, mode, sync, arg);
1523 static void memcg_wakeup_oom(struct mem_cgroup *mem)
1525 /* for filtering, pass "mem" as argument. */
1526 __wake_up(&memcg_oom_waitq, TASK_NORMAL, 0, mem);
1529 static void memcg_oom_recover(struct mem_cgroup *mem)
1531 if (mem && atomic_read(&mem->oom_lock))
1532 memcg_wakeup_oom(mem);
1536 * try to call OOM killer. returns false if we should exit memory-reclaim loop.
1538 bool mem_cgroup_handle_oom(struct mem_cgroup *mem, gfp_t mask)
1540 struct oom_wait_info owait;
1541 bool locked, need_to_kill;
1544 owait.wait.flags = 0;
1545 owait.wait.func = memcg_oom_wake_function;
1546 owait.wait.private = current;
1547 INIT_LIST_HEAD(&owait.wait.task_list);
1548 need_to_kill = true;
1549 /* At first, try to OOM lock hierarchy under mem.*/
1550 mutex_lock(&memcg_oom_mutex);
1551 locked = mem_cgroup_oom_lock(mem);
1553 * Even if signal_pending(), we can't quit charge() loop without
1554 * accounting. So, UNINTERRUPTIBLE is appropriate. But SIGKILL
1555 * under OOM is always welcomed, use TASK_KILLABLE here.
1557 prepare_to_wait(&memcg_oom_waitq, &owait.wait, TASK_KILLABLE);
1558 if (!locked || mem->oom_kill_disable)
1559 need_to_kill = false;
1561 mem_cgroup_oom_notify(mem);
1562 mutex_unlock(&memcg_oom_mutex);
1565 finish_wait(&memcg_oom_waitq, &owait.wait);
1566 mem_cgroup_out_of_memory(mem, mask);
1569 finish_wait(&memcg_oom_waitq, &owait.wait);
1571 mutex_lock(&memcg_oom_mutex);
1572 mem_cgroup_oom_unlock(mem);
1573 memcg_wakeup_oom(mem);
1574 mutex_unlock(&memcg_oom_mutex);
1576 if (test_thread_flag(TIF_MEMDIE) || fatal_signal_pending(current))
1578 /* Give chance to dying process */
1579 schedule_timeout(1);
1584 * Currently used to update mapped file statistics, but the routine can be
1585 * generalized to update other statistics as well.
1587 * Notes: Race condition
1589 * We usually use page_cgroup_lock() for accessing page_cgroup member but
1590 * it tends to be costly. But considering some conditions, we doesn't need
1591 * to do so _always_.
1593 * Considering "charge", lock_page_cgroup() is not required because all
1594 * file-stat operations happen after a page is attached to radix-tree. There
1595 * are no race with "charge".
1597 * Considering "uncharge", we know that memcg doesn't clear pc->mem_cgroup
1598 * at "uncharge" intentionally. So, we always see valid pc->mem_cgroup even
1599 * if there are race with "uncharge". Statistics itself is properly handled
1602 * Considering "move", this is an only case we see a race. To make the race
1603 * small, we check MEM_CGROUP_ON_MOVE percpu value and detect there are
1604 * possibility of race condition. If there is, we take a lock.
1607 static void mem_cgroup_update_file_stat(struct page *page, int idx, int val)
1609 struct mem_cgroup *mem;
1610 struct page_cgroup *pc = lookup_page_cgroup(page);
1611 bool need_unlock = false;
1617 mem = pc->mem_cgroup;
1618 if (unlikely(!mem || !PageCgroupUsed(pc)))
1620 /* pc->mem_cgroup is unstable ? */
1621 if (unlikely(mem_cgroup_stealed(mem))) {
1622 /* take a lock against to access pc->mem_cgroup */
1623 lock_page_cgroup(pc);
1625 mem = pc->mem_cgroup;
1626 if (!mem || !PageCgroupUsed(pc))
1630 this_cpu_add(mem->stat->count[idx], val);
1633 case MEM_CGROUP_STAT_FILE_MAPPED:
1635 SetPageCgroupFileMapped(pc);
1636 else if (!page_mapped(page))
1637 ClearPageCgroupFileMapped(pc);
1644 if (unlikely(need_unlock))
1645 unlock_page_cgroup(pc);
1650 void mem_cgroup_update_file_mapped(struct page *page, int val)
1652 mem_cgroup_update_file_stat(page, MEM_CGROUP_STAT_FILE_MAPPED, val);
1656 * size of first charge trial. "32" comes from vmscan.c's magic value.
1657 * TODO: maybe necessary to use big numbers in big irons.
1659 #define CHARGE_SIZE (32 * PAGE_SIZE)
1660 struct memcg_stock_pcp {
1661 struct mem_cgroup *cached; /* this never be root cgroup */
1663 struct work_struct work;
1665 static DEFINE_PER_CPU(struct memcg_stock_pcp, memcg_stock);
1666 static atomic_t memcg_drain_count;
1669 * Try to consume stocked charge on this cpu. If success, PAGE_SIZE is consumed
1670 * from local stock and true is returned. If the stock is 0 or charges from a
1671 * cgroup which is not current target, returns false. This stock will be
1674 static bool consume_stock(struct mem_cgroup *mem)
1676 struct memcg_stock_pcp *stock;
1679 stock = &get_cpu_var(memcg_stock);
1680 if (mem == stock->cached && stock->charge)
1681 stock->charge -= PAGE_SIZE;
1682 else /* need to call res_counter_charge */
1684 put_cpu_var(memcg_stock);
1689 * Returns stocks cached in percpu to res_counter and reset cached information.
1691 static void drain_stock(struct memcg_stock_pcp *stock)
1693 struct mem_cgroup *old = stock->cached;
1695 if (stock->charge) {
1696 res_counter_uncharge(&old->res, stock->charge);
1697 if (do_swap_account)
1698 res_counter_uncharge(&old->memsw, stock->charge);
1700 stock->cached = NULL;
1705 * This must be called under preempt disabled or must be called by
1706 * a thread which is pinned to local cpu.
1708 static void drain_local_stock(struct work_struct *dummy)
1710 struct memcg_stock_pcp *stock = &__get_cpu_var(memcg_stock);
1715 * Cache charges(val) which is from res_counter, to local per_cpu area.
1716 * This will be consumed by consume_stock() function, later.
1718 static void refill_stock(struct mem_cgroup *mem, int val)
1720 struct memcg_stock_pcp *stock = &get_cpu_var(memcg_stock);
1722 if (stock->cached != mem) { /* reset if necessary */
1724 stock->cached = mem;
1726 stock->charge += val;
1727 put_cpu_var(memcg_stock);
1731 * Tries to drain stocked charges in other cpus. This function is asynchronous
1732 * and just put a work per cpu for draining localy on each cpu. Caller can
1733 * expects some charges will be back to res_counter later but cannot wait for
1736 static void drain_all_stock_async(void)
1739 /* This function is for scheduling "drain" in asynchronous way.
1740 * The result of "drain" is not directly handled by callers. Then,
1741 * if someone is calling drain, we don't have to call drain more.
1742 * Anyway, WORK_STRUCT_PENDING check in queue_work_on() will catch if
1743 * there is a race. We just do loose check here.
1745 if (atomic_read(&memcg_drain_count))
1747 /* Notify other cpus that system-wide "drain" is running */
1748 atomic_inc(&memcg_drain_count);
1750 for_each_online_cpu(cpu) {
1751 struct memcg_stock_pcp *stock = &per_cpu(memcg_stock, cpu);
1752 schedule_work_on(cpu, &stock->work);
1755 atomic_dec(&memcg_drain_count);
1756 /* We don't wait for flush_work */
1759 /* This is a synchronous drain interface. */
1760 static void drain_all_stock_sync(void)
1762 /* called when force_empty is called */
1763 atomic_inc(&memcg_drain_count);
1764 schedule_on_each_cpu(drain_local_stock);
1765 atomic_dec(&memcg_drain_count);
1769 * This function drains percpu counter value from DEAD cpu and
1770 * move it to local cpu. Note that this function can be preempted.
1772 static void mem_cgroup_drain_pcp_counter(struct mem_cgroup *mem, int cpu)
1776 spin_lock(&mem->pcp_counter_lock);
1777 for (i = 0; i < MEM_CGROUP_STAT_DATA; i++) {
1778 s64 x = per_cpu(mem->stat->count[i], cpu);
1780 per_cpu(mem->stat->count[i], cpu) = 0;
1781 mem->nocpu_base.count[i] += x;
1783 /* need to clear ON_MOVE value, works as a kind of lock. */
1784 per_cpu(mem->stat->count[MEM_CGROUP_ON_MOVE], cpu) = 0;
1785 spin_unlock(&mem->pcp_counter_lock);
1788 static void synchronize_mem_cgroup_on_move(struct mem_cgroup *mem, int cpu)
1790 int idx = MEM_CGROUP_ON_MOVE;
1792 spin_lock(&mem->pcp_counter_lock);
1793 per_cpu(mem->stat->count[idx], cpu) = mem->nocpu_base.count[idx];
1794 spin_unlock(&mem->pcp_counter_lock);
1797 static int __cpuinit memcg_cpu_hotplug_callback(struct notifier_block *nb,
1798 unsigned long action,
1801 int cpu = (unsigned long)hcpu;
1802 struct memcg_stock_pcp *stock;
1803 struct mem_cgroup *iter;
1805 if ((action == CPU_ONLINE)) {
1806 for_each_mem_cgroup_all(iter)
1807 synchronize_mem_cgroup_on_move(iter, cpu);
1811 if ((action != CPU_DEAD) || action != CPU_DEAD_FROZEN)
1814 for_each_mem_cgroup_all(iter)
1815 mem_cgroup_drain_pcp_counter(iter, cpu);
1817 stock = &per_cpu(memcg_stock, cpu);
1823 /* See __mem_cgroup_try_charge() for details */
1825 CHARGE_OK, /* success */
1826 CHARGE_RETRY, /* need to retry but retry is not bad */
1827 CHARGE_NOMEM, /* we can't do more. return -ENOMEM */
1828 CHARGE_WOULDBLOCK, /* GFP_WAIT wasn't set and no enough res. */
1829 CHARGE_OOM_DIE, /* the current is killed because of OOM */
1832 static int __mem_cgroup_do_charge(struct mem_cgroup *mem, gfp_t gfp_mask,
1833 int csize, bool oom_check)
1835 struct mem_cgroup *mem_over_limit;
1836 struct res_counter *fail_res;
1837 unsigned long flags = 0;
1840 ret = res_counter_charge(&mem->res, csize, &fail_res);
1843 if (!do_swap_account)
1845 ret = res_counter_charge(&mem->memsw, csize, &fail_res);
1849 mem_over_limit = mem_cgroup_from_res_counter(fail_res, memsw);
1850 flags |= MEM_CGROUP_RECLAIM_NOSWAP;
1852 mem_over_limit = mem_cgroup_from_res_counter(fail_res, res);
1854 if (csize > PAGE_SIZE) /* change csize and retry */
1855 return CHARGE_RETRY;
1857 if (!(gfp_mask & __GFP_WAIT))
1858 return CHARGE_WOULDBLOCK;
1860 ret = mem_cgroup_hierarchical_reclaim(mem_over_limit, NULL,
1863 * try_to_free_mem_cgroup_pages() might not give us a full
1864 * picture of reclaim. Some pages are reclaimed and might be
1865 * moved to swap cache or just unmapped from the cgroup.
1866 * Check the limit again to see if the reclaim reduced the
1867 * current usage of the cgroup before giving up
1869 if (ret || mem_cgroup_check_under_limit(mem_over_limit))
1870 return CHARGE_RETRY;
1873 * At task move, charge accounts can be doubly counted. So, it's
1874 * better to wait until the end of task_move if something is going on.
1876 if (mem_cgroup_wait_acct_move(mem_over_limit))
1877 return CHARGE_RETRY;
1879 /* If we don't need to call oom-killer at el, return immediately */
1881 return CHARGE_NOMEM;
1883 if (!mem_cgroup_handle_oom(mem_over_limit, gfp_mask))
1884 return CHARGE_OOM_DIE;
1886 return CHARGE_RETRY;
1890 * Unlike exported interface, "oom" parameter is added. if oom==true,
1891 * oom-killer can be invoked.
1893 static int __mem_cgroup_try_charge(struct mm_struct *mm,
1895 struct mem_cgroup **memcg, bool oom,
1898 int nr_oom_retries = MEM_CGROUP_RECLAIM_RETRIES;
1899 struct mem_cgroup *mem = NULL;
1901 int csize = max(CHARGE_SIZE, (unsigned long) page_size);
1904 * Unlike gloval-vm's OOM-kill, we're not in memory shortage
1905 * in system level. So, allow to go ahead dying process in addition to
1908 if (unlikely(test_thread_flag(TIF_MEMDIE)
1909 || fatal_signal_pending(current)))
1913 * We always charge the cgroup the mm_struct belongs to.
1914 * The mm_struct's mem_cgroup changes on task migration if the
1915 * thread group leader migrates. It's possible that mm is not
1916 * set, if so charge the init_mm (happens for pagecache usage).
1921 if (*memcg) { /* css should be a valid one */
1923 VM_BUG_ON(css_is_removed(&mem->css));
1924 if (mem_cgroup_is_root(mem))
1926 if (page_size == PAGE_SIZE && consume_stock(mem))
1930 struct task_struct *p;
1933 p = rcu_dereference(mm->owner);
1935 * Because we don't have task_lock(), "p" can exit.
1936 * In that case, "mem" can point to root or p can be NULL with
1937 * race with swapoff. Then, we have small risk of mis-accouning.
1938 * But such kind of mis-account by race always happens because
1939 * we don't have cgroup_mutex(). It's overkill and we allo that
1941 * (*) swapoff at el will charge against mm-struct not against
1942 * task-struct. So, mm->owner can be NULL.
1944 mem = mem_cgroup_from_task(p);
1945 if (!mem || mem_cgroup_is_root(mem)) {
1949 if (page_size == PAGE_SIZE && consume_stock(mem)) {
1951 * It seems dagerous to access memcg without css_get().
1952 * But considering how consume_stok works, it's not
1953 * necessary. If consume_stock success, some charges
1954 * from this memcg are cached on this cpu. So, we
1955 * don't need to call css_get()/css_tryget() before
1956 * calling consume_stock().
1961 /* after here, we may be blocked. we need to get refcnt */
1962 if (!css_tryget(&mem->css)) {
1972 /* If killed, bypass charge */
1973 if (fatal_signal_pending(current)) {
1979 if (oom && !nr_oom_retries) {
1981 nr_oom_retries = MEM_CGROUP_RECLAIM_RETRIES;
1984 ret = __mem_cgroup_do_charge(mem, gfp_mask, csize, oom_check);
1989 case CHARGE_RETRY: /* not in OOM situation but retry */
1994 case CHARGE_WOULDBLOCK: /* !__GFP_WAIT */
1997 case CHARGE_NOMEM: /* OOM routine works */
2002 /* If oom, we never return -ENOMEM */
2005 case CHARGE_OOM_DIE: /* Killed by OOM Killer */
2009 } while (ret != CHARGE_OK);
2011 if (csize > page_size)
2012 refill_stock(mem, csize - page_size);
2026 * Somemtimes we have to undo a charge we got by try_charge().
2027 * This function is for that and do uncharge, put css's refcnt.
2028 * gotten by try_charge().
2030 static void __mem_cgroup_cancel_charge(struct mem_cgroup *mem,
2031 unsigned long count)
2033 if (!mem_cgroup_is_root(mem)) {
2034 res_counter_uncharge(&mem->res, PAGE_SIZE * count);
2035 if (do_swap_account)
2036 res_counter_uncharge(&mem->memsw, PAGE_SIZE * count);
2040 static void mem_cgroup_cancel_charge(struct mem_cgroup *mem,
2043 __mem_cgroup_cancel_charge(mem, page_size >> PAGE_SHIFT);
2047 * A helper function to get mem_cgroup from ID. must be called under
2048 * rcu_read_lock(). The caller must check css_is_removed() or some if
2049 * it's concern. (dropping refcnt from swap can be called against removed
2052 static struct mem_cgroup *mem_cgroup_lookup(unsigned short id)
2054 struct cgroup_subsys_state *css;
2056 /* ID 0 is unused ID */
2059 css = css_lookup(&mem_cgroup_subsys, id);
2062 return container_of(css, struct mem_cgroup, css);
2065 struct mem_cgroup *try_get_mem_cgroup_from_page(struct page *page)
2067 struct mem_cgroup *mem = NULL;
2068 struct page_cgroup *pc;
2072 VM_BUG_ON(!PageLocked(page));
2074 pc = lookup_page_cgroup(page);
2075 lock_page_cgroup(pc);
2076 if (PageCgroupUsed(pc)) {
2077 mem = pc->mem_cgroup;
2078 if (mem && !css_tryget(&mem->css))
2080 } else if (PageSwapCache(page)) {
2081 ent.val = page_private(page);
2082 id = lookup_swap_cgroup(ent);
2084 mem = mem_cgroup_lookup(id);
2085 if (mem && !css_tryget(&mem->css))
2089 unlock_page_cgroup(pc);
2094 * commit a charge got by __mem_cgroup_try_charge() and makes page_cgroup to be
2095 * USED state. If already USED, uncharge and return.
2097 static void ____mem_cgroup_commit_charge(struct mem_cgroup *mem,
2098 struct page_cgroup *pc,
2099 enum charge_type ctype)
2101 pc->mem_cgroup = mem;
2103 * We access a page_cgroup asynchronously without lock_page_cgroup().
2104 * Especially when a page_cgroup is taken from a page, pc->mem_cgroup
2105 * is accessed after testing USED bit. To make pc->mem_cgroup visible
2106 * before USED bit, we need memory barrier here.
2107 * See mem_cgroup_add_lru_list(), etc.
2111 case MEM_CGROUP_CHARGE_TYPE_CACHE:
2112 case MEM_CGROUP_CHARGE_TYPE_SHMEM:
2113 SetPageCgroupCache(pc);
2114 SetPageCgroupUsed(pc);
2116 case MEM_CGROUP_CHARGE_TYPE_MAPPED:
2117 ClearPageCgroupCache(pc);
2118 SetPageCgroupUsed(pc);
2124 mem_cgroup_charge_statistics(mem, pc, true);
2127 static void __mem_cgroup_commit_charge(struct mem_cgroup *mem,
2128 struct page_cgroup *pc,
2129 enum charge_type ctype,
2133 int count = page_size >> PAGE_SHIFT;
2135 /* try_charge() can return NULL to *memcg, taking care of it. */
2139 lock_page_cgroup(pc);
2140 if (unlikely(PageCgroupUsed(pc))) {
2141 unlock_page_cgroup(pc);
2142 mem_cgroup_cancel_charge(mem, page_size);
2147 * we don't need page_cgroup_lock about tail pages, becase they are not
2148 * accessed by any other context at this point.
2150 for (i = 0; i < count; i++)
2151 ____mem_cgroup_commit_charge(mem, pc + i, ctype);
2153 unlock_page_cgroup(pc);
2155 * "charge_statistics" updated event counter. Then, check it.
2156 * Insert ancestor (and ancestor's ancestors), to softlimit RB-tree.
2157 * if they exceeds softlimit.
2159 memcg_check_events(mem, pc->page);
2163 * __mem_cgroup_move_account - move account of the page
2164 * @pc: page_cgroup of the page.
2165 * @from: mem_cgroup which the page is moved from.
2166 * @to: mem_cgroup which the page is moved to. @from != @to.
2167 * @uncharge: whether we should call uncharge and css_put against @from.
2169 * The caller must confirm following.
2170 * - page is not on LRU (isolate_page() is useful.)
2171 * - the pc is locked, used, and ->mem_cgroup points to @from.
2173 * This function doesn't do "charge" nor css_get to new cgroup. It should be
2174 * done by a caller(__mem_cgroup_try_charge would be usefull). If @uncharge is
2175 * true, this function does "uncharge" from old cgroup, but it doesn't if
2176 * @uncharge is false, so a caller should do "uncharge".
2179 static void __mem_cgroup_move_account(struct page_cgroup *pc,
2180 struct mem_cgroup *from, struct mem_cgroup *to, bool uncharge)
2182 VM_BUG_ON(from == to);
2183 VM_BUG_ON(PageLRU(pc->page));
2184 VM_BUG_ON(!page_is_cgroup_locked(pc));
2185 VM_BUG_ON(!PageCgroupUsed(pc));
2186 VM_BUG_ON(pc->mem_cgroup != from);
2188 if (PageCgroupFileMapped(pc)) {
2189 /* Update mapped_file data for mem_cgroup */
2191 __this_cpu_dec(from->stat->count[MEM_CGROUP_STAT_FILE_MAPPED]);
2192 __this_cpu_inc(to->stat->count[MEM_CGROUP_STAT_FILE_MAPPED]);
2195 mem_cgroup_charge_statistics(from, pc, false);
2197 /* This is not "cancel", but cancel_charge does all we need. */
2198 mem_cgroup_cancel_charge(from, PAGE_SIZE);
2200 /* caller should have done css_get */
2201 pc->mem_cgroup = to;
2202 mem_cgroup_charge_statistics(to, pc, true);
2204 * We charges against "to" which may not have any tasks. Then, "to"
2205 * can be under rmdir(). But in current implementation, caller of
2206 * this function is just force_empty() and move charge, so it's
2207 * garanteed that "to" is never removed. So, we don't check rmdir
2213 * check whether the @pc is valid for moving account and call
2214 * __mem_cgroup_move_account()
2216 static int mem_cgroup_move_account(struct page_cgroup *pc,
2217 struct mem_cgroup *from, struct mem_cgroup *to, bool uncharge)
2220 lock_page_cgroup(pc);
2221 if (PageCgroupUsed(pc) && pc->mem_cgroup == from) {
2222 __mem_cgroup_move_account(pc, from, to, uncharge);
2225 unlock_page_cgroup(pc);
2229 memcg_check_events(to, pc->page);
2230 memcg_check_events(from, pc->page);
2235 * move charges to its parent.
2238 static int mem_cgroup_move_parent(struct page_cgroup *pc,
2239 struct mem_cgroup *child,
2242 struct page *page = pc->page;
2243 struct cgroup *cg = child->css.cgroup;
2244 struct cgroup *pcg = cg->parent;
2245 struct mem_cgroup *parent;
2253 if (!get_page_unless_zero(page))
2255 if (isolate_lru_page(page))
2258 parent = mem_cgroup_from_cont(pcg);
2259 ret = __mem_cgroup_try_charge(NULL, gfp_mask, &parent, false,
2264 ret = mem_cgroup_move_account(pc, child, parent, true);
2266 mem_cgroup_cancel_charge(parent, PAGE_SIZE);
2268 putback_lru_page(page);
2276 * Charge the memory controller for page usage.
2278 * 0 if the charge was successful
2279 * < 0 if the cgroup is over its limit
2281 static int mem_cgroup_charge_common(struct page *page, struct mm_struct *mm,
2282 gfp_t gfp_mask, enum charge_type ctype)
2284 struct mem_cgroup *mem = NULL;
2285 struct page_cgroup *pc;
2287 int page_size = PAGE_SIZE;
2289 if (PageTransHuge(page))
2290 page_size <<= compound_order(page);
2292 pc = lookup_page_cgroup(page);
2293 /* can happen at boot */
2298 ret = __mem_cgroup_try_charge(mm, gfp_mask, &mem, true, page_size);
2302 __mem_cgroup_commit_charge(mem, pc, ctype, page_size);
2306 int mem_cgroup_newpage_charge(struct page *page,
2307 struct mm_struct *mm, gfp_t gfp_mask)
2309 if (mem_cgroup_disabled())
2312 * If already mapped, we don't have to account.
2313 * If page cache, page->mapping has address_space.
2314 * But page->mapping may have out-of-use anon_vma pointer,
2315 * detecit it by PageAnon() check. newly-mapped-anon's page->mapping
2318 if (page_mapped(page) || (page->mapping && !PageAnon(page)))
2322 return mem_cgroup_charge_common(page, mm, gfp_mask,
2323 MEM_CGROUP_CHARGE_TYPE_MAPPED);
2327 __mem_cgroup_commit_charge_swapin(struct page *page, struct mem_cgroup *ptr,
2328 enum charge_type ctype);
2330 int mem_cgroup_cache_charge(struct page *page, struct mm_struct *mm,
2335 if (mem_cgroup_disabled())
2337 if (PageCompound(page))
2340 * Corner case handling. This is called from add_to_page_cache()
2341 * in usual. But some FS (shmem) precharges this page before calling it
2342 * and call add_to_page_cache() with GFP_NOWAIT.
2344 * For GFP_NOWAIT case, the page may be pre-charged before calling
2345 * add_to_page_cache(). (See shmem.c) check it here and avoid to call
2346 * charge twice. (It works but has to pay a bit larger cost.)
2347 * And when the page is SwapCache, it should take swap information
2348 * into account. This is under lock_page() now.
2350 if (!(gfp_mask & __GFP_WAIT)) {
2351 struct page_cgroup *pc;
2353 pc = lookup_page_cgroup(page);
2356 lock_page_cgroup(pc);
2357 if (PageCgroupUsed(pc)) {
2358 unlock_page_cgroup(pc);
2361 unlock_page_cgroup(pc);
2367 if (page_is_file_cache(page))
2368 return mem_cgroup_charge_common(page, mm, gfp_mask,
2369 MEM_CGROUP_CHARGE_TYPE_CACHE);
2372 if (PageSwapCache(page)) {
2373 struct mem_cgroup *mem = NULL;
2375 ret = mem_cgroup_try_charge_swapin(mm, page, gfp_mask, &mem);
2377 __mem_cgroup_commit_charge_swapin(page, mem,
2378 MEM_CGROUP_CHARGE_TYPE_SHMEM);
2380 ret = mem_cgroup_charge_common(page, mm, gfp_mask,
2381 MEM_CGROUP_CHARGE_TYPE_SHMEM);
2387 * While swap-in, try_charge -> commit or cancel, the page is locked.
2388 * And when try_charge() successfully returns, one refcnt to memcg without
2389 * struct page_cgroup is acquired. This refcnt will be consumed by
2390 * "commit()" or removed by "cancel()"
2392 int mem_cgroup_try_charge_swapin(struct mm_struct *mm,
2394 gfp_t mask, struct mem_cgroup **ptr)
2396 struct mem_cgroup *mem;
2399 if (mem_cgroup_disabled())
2402 if (!do_swap_account)
2405 * A racing thread's fault, or swapoff, may have already updated
2406 * the pte, and even removed page from swap cache: in those cases
2407 * do_swap_page()'s pte_same() test will fail; but there's also a
2408 * KSM case which does need to charge the page.
2410 if (!PageSwapCache(page))
2412 mem = try_get_mem_cgroup_from_page(page);
2416 ret = __mem_cgroup_try_charge(NULL, mask, ptr, true, PAGE_SIZE);
2422 return __mem_cgroup_try_charge(mm, mask, ptr, true, PAGE_SIZE);
2426 __mem_cgroup_commit_charge_swapin(struct page *page, struct mem_cgroup *ptr,
2427 enum charge_type ctype)
2429 struct page_cgroup *pc;
2431 if (mem_cgroup_disabled())
2435 cgroup_exclude_rmdir(&ptr->css);
2436 pc = lookup_page_cgroup(page);
2437 mem_cgroup_lru_del_before_commit_swapcache(page);
2438 __mem_cgroup_commit_charge(ptr, pc, ctype, PAGE_SIZE);
2439 mem_cgroup_lru_add_after_commit_swapcache(page);
2441 * Now swap is on-memory. This means this page may be
2442 * counted both as mem and swap....double count.
2443 * Fix it by uncharging from memsw. Basically, this SwapCache is stable
2444 * under lock_page(). But in do_swap_page()::memory.c, reuse_swap_page()
2445 * may call delete_from_swap_cache() before reach here.
2447 if (do_swap_account && PageSwapCache(page)) {
2448 swp_entry_t ent = {.val = page_private(page)};
2450 struct mem_cgroup *memcg;
2452 id = swap_cgroup_record(ent, 0);
2454 memcg = mem_cgroup_lookup(id);
2457 * This recorded memcg can be obsolete one. So, avoid
2458 * calling css_tryget
2460 if (!mem_cgroup_is_root(memcg))
2461 res_counter_uncharge(&memcg->memsw, PAGE_SIZE);
2462 mem_cgroup_swap_statistics(memcg, false);
2463 mem_cgroup_put(memcg);
2468 * At swapin, we may charge account against cgroup which has no tasks.
2469 * So, rmdir()->pre_destroy() can be called while we do this charge.
2470 * In that case, we need to call pre_destroy() again. check it here.
2472 cgroup_release_and_wakeup_rmdir(&ptr->css);
2475 void mem_cgroup_commit_charge_swapin(struct page *page, struct mem_cgroup *ptr)
2477 __mem_cgroup_commit_charge_swapin(page, ptr,
2478 MEM_CGROUP_CHARGE_TYPE_MAPPED);
2481 void mem_cgroup_cancel_charge_swapin(struct mem_cgroup *mem)
2483 if (mem_cgroup_disabled())
2487 mem_cgroup_cancel_charge(mem, PAGE_SIZE);
2491 __do_uncharge(struct mem_cgroup *mem, const enum charge_type ctype,
2494 struct memcg_batch_info *batch = NULL;
2495 bool uncharge_memsw = true;
2496 /* If swapout, usage of swap doesn't decrease */
2497 if (!do_swap_account || ctype == MEM_CGROUP_CHARGE_TYPE_SWAPOUT)
2498 uncharge_memsw = false;
2500 batch = ¤t->memcg_batch;
2502 * In usual, we do css_get() when we remember memcg pointer.
2503 * But in this case, we keep res->usage until end of a series of
2504 * uncharges. Then, it's ok to ignore memcg's refcnt.
2509 * do_batch > 0 when unmapping pages or inode invalidate/truncate.
2510 * In those cases, all pages freed continously can be expected to be in
2511 * the same cgroup and we have chance to coalesce uncharges.
2512 * But we do uncharge one by one if this is killed by OOM(TIF_MEMDIE)
2513 * because we want to do uncharge as soon as possible.
2516 if (!batch->do_batch || test_thread_flag(TIF_MEMDIE))
2517 goto direct_uncharge;
2519 if (page_size != PAGE_SIZE)
2520 goto direct_uncharge;
2523 * In typical case, batch->memcg == mem. This means we can
2524 * merge a series of uncharges to an uncharge of res_counter.
2525 * If not, we uncharge res_counter ony by one.
2527 if (batch->memcg != mem)
2528 goto direct_uncharge;
2529 /* remember freed charge and uncharge it later */
2530 batch->bytes += PAGE_SIZE;
2532 batch->memsw_bytes += PAGE_SIZE;
2535 res_counter_uncharge(&mem->res, page_size);
2537 res_counter_uncharge(&mem->memsw, page_size);
2538 if (unlikely(batch->memcg != mem))
2539 memcg_oom_recover(mem);
2544 * uncharge if !page_mapped(page)
2546 static struct mem_cgroup *
2547 __mem_cgroup_uncharge_common(struct page *page, enum charge_type ctype)
2551 struct page_cgroup *pc;
2552 struct mem_cgroup *mem = NULL;
2553 int page_size = PAGE_SIZE;
2555 if (mem_cgroup_disabled())
2558 if (PageSwapCache(page))
2561 if (PageTransHuge(page))
2562 page_size <<= compound_order(page);
2564 count = page_size >> PAGE_SHIFT;
2566 * Check if our page_cgroup is valid
2568 pc = lookup_page_cgroup(page);
2569 if (unlikely(!pc || !PageCgroupUsed(pc)))
2572 lock_page_cgroup(pc);
2574 mem = pc->mem_cgroup;
2576 if (!PageCgroupUsed(pc))
2580 case MEM_CGROUP_CHARGE_TYPE_MAPPED:
2581 case MEM_CGROUP_CHARGE_TYPE_DROP:
2582 /* See mem_cgroup_prepare_migration() */
2583 if (page_mapped(page) || PageCgroupMigration(pc))
2586 case MEM_CGROUP_CHARGE_TYPE_SWAPOUT:
2587 if (!PageAnon(page)) { /* Shared memory */
2588 if (page->mapping && !page_is_file_cache(page))
2590 } else if (page_mapped(page)) /* Anon */
2597 for (i = 0; i < count; i++)
2598 mem_cgroup_charge_statistics(mem, pc + i, false);
2600 ClearPageCgroupUsed(pc);
2602 * pc->mem_cgroup is not cleared here. It will be accessed when it's
2603 * freed from LRU. This is safe because uncharged page is expected not
2604 * to be reused (freed soon). Exception is SwapCache, it's handled by
2605 * special functions.
2608 unlock_page_cgroup(pc);
2610 * even after unlock, we have mem->res.usage here and this memcg
2611 * will never be freed.
2613 memcg_check_events(mem, page);
2614 if (do_swap_account && ctype == MEM_CGROUP_CHARGE_TYPE_SWAPOUT) {
2615 mem_cgroup_swap_statistics(mem, true);
2616 mem_cgroup_get(mem);
2618 if (!mem_cgroup_is_root(mem))
2619 __do_uncharge(mem, ctype, page_size);
2624 unlock_page_cgroup(pc);
2628 void mem_cgroup_uncharge_page(struct page *page)
2631 if (page_mapped(page))
2633 if (page->mapping && !PageAnon(page))
2635 __mem_cgroup_uncharge_common(page, MEM_CGROUP_CHARGE_TYPE_MAPPED);
2638 void mem_cgroup_uncharge_cache_page(struct page *page)
2640 VM_BUG_ON(page_mapped(page));
2641 VM_BUG_ON(page->mapping);
2642 __mem_cgroup_uncharge_common(page, MEM_CGROUP_CHARGE_TYPE_CACHE);
2646 * Batch_start/batch_end is called in unmap_page_range/invlidate/trucate.
2647 * In that cases, pages are freed continuously and we can expect pages
2648 * are in the same memcg. All these calls itself limits the number of
2649 * pages freed at once, then uncharge_start/end() is called properly.
2650 * This may be called prural(2) times in a context,
2653 void mem_cgroup_uncharge_start(void)
2655 current->memcg_batch.do_batch++;
2656 /* We can do nest. */
2657 if (current->memcg_batch.do_batch == 1) {
2658 current->memcg_batch.memcg = NULL;
2659 current->memcg_batch.bytes = 0;
2660 current->memcg_batch.memsw_bytes = 0;
2664 void mem_cgroup_uncharge_end(void)
2666 struct memcg_batch_info *batch = ¤t->memcg_batch;
2668 if (!batch->do_batch)
2672 if (batch->do_batch) /* If stacked, do nothing. */
2678 * This "batch->memcg" is valid without any css_get/put etc...
2679 * bacause we hide charges behind us.
2682 res_counter_uncharge(&batch->memcg->res, batch->bytes);
2683 if (batch->memsw_bytes)
2684 res_counter_uncharge(&batch->memcg->memsw, batch->memsw_bytes);
2685 memcg_oom_recover(batch->memcg);
2686 /* forget this pointer (for sanity check) */
2687 batch->memcg = NULL;
2692 * called after __delete_from_swap_cache() and drop "page" account.
2693 * memcg information is recorded to swap_cgroup of "ent"
2696 mem_cgroup_uncharge_swapcache(struct page *page, swp_entry_t ent, bool swapout)
2698 struct mem_cgroup *memcg;
2699 int ctype = MEM_CGROUP_CHARGE_TYPE_SWAPOUT;
2701 if (!swapout) /* this was a swap cache but the swap is unused ! */
2702 ctype = MEM_CGROUP_CHARGE_TYPE_DROP;
2704 memcg = __mem_cgroup_uncharge_common(page, ctype);
2707 * record memcg information, if swapout && memcg != NULL,
2708 * mem_cgroup_get() was called in uncharge().
2710 if (do_swap_account && swapout && memcg)
2711 swap_cgroup_record(ent, css_id(&memcg->css));
2715 #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP
2717 * called from swap_entry_free(). remove record in swap_cgroup and
2718 * uncharge "memsw" account.
2720 void mem_cgroup_uncharge_swap(swp_entry_t ent)
2722 struct mem_cgroup *memcg;
2725 if (!do_swap_account)
2728 id = swap_cgroup_record(ent, 0);
2730 memcg = mem_cgroup_lookup(id);
2733 * We uncharge this because swap is freed.
2734 * This memcg can be obsolete one. We avoid calling css_tryget
2736 if (!mem_cgroup_is_root(memcg))
2737 res_counter_uncharge(&memcg->memsw, PAGE_SIZE);
2738 mem_cgroup_swap_statistics(memcg, false);
2739 mem_cgroup_put(memcg);
2745 * mem_cgroup_move_swap_account - move swap charge and swap_cgroup's record.
2746 * @entry: swap entry to be moved
2747 * @from: mem_cgroup which the entry is moved from
2748 * @to: mem_cgroup which the entry is moved to
2749 * @need_fixup: whether we should fixup res_counters and refcounts.
2751 * It succeeds only when the swap_cgroup's record for this entry is the same
2752 * as the mem_cgroup's id of @from.
2754 * Returns 0 on success, -EINVAL on failure.
2756 * The caller must have charged to @to, IOW, called res_counter_charge() about
2757 * both res and memsw, and called css_get().
2759 static int mem_cgroup_move_swap_account(swp_entry_t entry,
2760 struct mem_cgroup *from, struct mem_cgroup *to, bool need_fixup)
2762 unsigned short old_id, new_id;
2764 old_id = css_id(&from->css);
2765 new_id = css_id(&to->css);
2767 if (swap_cgroup_cmpxchg(entry, old_id, new_id) == old_id) {
2768 mem_cgroup_swap_statistics(from, false);
2769 mem_cgroup_swap_statistics(to, true);
2771 * This function is only called from task migration context now.
2772 * It postpones res_counter and refcount handling till the end
2773 * of task migration(mem_cgroup_clear_mc()) for performance
2774 * improvement. But we cannot postpone mem_cgroup_get(to)
2775 * because if the process that has been moved to @to does
2776 * swap-in, the refcount of @to might be decreased to 0.
2780 if (!mem_cgroup_is_root(from))
2781 res_counter_uncharge(&from->memsw, PAGE_SIZE);
2782 mem_cgroup_put(from);
2784 * we charged both to->res and to->memsw, so we should
2787 if (!mem_cgroup_is_root(to))
2788 res_counter_uncharge(&to->res, PAGE_SIZE);
2795 static inline int mem_cgroup_move_swap_account(swp_entry_t entry,
2796 struct mem_cgroup *from, struct mem_cgroup *to, bool need_fixup)
2803 * Before starting migration, account PAGE_SIZE to mem_cgroup that the old
2806 int mem_cgroup_prepare_migration(struct page *page,
2807 struct page *newpage, struct mem_cgroup **ptr)
2809 struct page_cgroup *pc;
2810 struct mem_cgroup *mem = NULL;
2811 enum charge_type ctype;
2814 VM_BUG_ON(PageTransHuge(page));
2815 if (mem_cgroup_disabled())
2818 pc = lookup_page_cgroup(page);
2819 lock_page_cgroup(pc);
2820 if (PageCgroupUsed(pc)) {
2821 mem = pc->mem_cgroup;
2824 * At migrating an anonymous page, its mapcount goes down
2825 * to 0 and uncharge() will be called. But, even if it's fully
2826 * unmapped, migration may fail and this page has to be
2827 * charged again. We set MIGRATION flag here and delay uncharge
2828 * until end_migration() is called
2830 * Corner Case Thinking
2832 * When the old page was mapped as Anon and it's unmap-and-freed
2833 * while migration was ongoing.
2834 * If unmap finds the old page, uncharge() of it will be delayed
2835 * until end_migration(). If unmap finds a new page, it's
2836 * uncharged when it make mapcount to be 1->0. If unmap code
2837 * finds swap_migration_entry, the new page will not be mapped
2838 * and end_migration() will find it(mapcount==0).
2841 * When the old page was mapped but migraion fails, the kernel
2842 * remaps it. A charge for it is kept by MIGRATION flag even
2843 * if mapcount goes down to 0. We can do remap successfully
2844 * without charging it again.
2847 * The "old" page is under lock_page() until the end of
2848 * migration, so, the old page itself will not be swapped-out.
2849 * If the new page is swapped out before end_migraton, our
2850 * hook to usual swap-out path will catch the event.
2853 SetPageCgroupMigration(pc);
2855 unlock_page_cgroup(pc);
2857 * If the page is not charged at this point,
2864 ret = __mem_cgroup_try_charge(NULL, GFP_KERNEL, ptr, false, PAGE_SIZE);
2865 css_put(&mem->css);/* drop extra refcnt */
2866 if (ret || *ptr == NULL) {
2867 if (PageAnon(page)) {
2868 lock_page_cgroup(pc);
2869 ClearPageCgroupMigration(pc);
2870 unlock_page_cgroup(pc);
2872 * The old page may be fully unmapped while we kept it.
2874 mem_cgroup_uncharge_page(page);
2879 * We charge new page before it's used/mapped. So, even if unlock_page()
2880 * is called before end_migration, we can catch all events on this new
2881 * page. In the case new page is migrated but not remapped, new page's
2882 * mapcount will be finally 0 and we call uncharge in end_migration().
2884 pc = lookup_page_cgroup(newpage);
2886 ctype = MEM_CGROUP_CHARGE_TYPE_MAPPED;
2887 else if (page_is_file_cache(page))
2888 ctype = MEM_CGROUP_CHARGE_TYPE_CACHE;
2890 ctype = MEM_CGROUP_CHARGE_TYPE_SHMEM;
2891 __mem_cgroup_commit_charge(mem, pc, ctype, PAGE_SIZE);
2895 /* remove redundant charge if migration failed*/
2896 void mem_cgroup_end_migration(struct mem_cgroup *mem,
2897 struct page *oldpage, struct page *newpage)
2899 struct page *used, *unused;
2900 struct page_cgroup *pc;
2904 /* blocks rmdir() */
2905 cgroup_exclude_rmdir(&mem->css);
2906 /* at migration success, oldpage->mapping is NULL. */
2907 if (oldpage->mapping) {
2915 * We disallowed uncharge of pages under migration because mapcount
2916 * of the page goes down to zero, temporarly.
2917 * Clear the flag and check the page should be charged.
2919 pc = lookup_page_cgroup(oldpage);
2920 lock_page_cgroup(pc);
2921 ClearPageCgroupMigration(pc);
2922 unlock_page_cgroup(pc);
2924 __mem_cgroup_uncharge_common(unused, MEM_CGROUP_CHARGE_TYPE_FORCE);
2927 * If a page is a file cache, radix-tree replacement is very atomic
2928 * and we can skip this check. When it was an Anon page, its mapcount
2929 * goes down to 0. But because we added MIGRATION flage, it's not
2930 * uncharged yet. There are several case but page->mapcount check
2931 * and USED bit check in mem_cgroup_uncharge_page() will do enough
2932 * check. (see prepare_charge() also)
2935 mem_cgroup_uncharge_page(used);
2937 * At migration, we may charge account against cgroup which has no
2939 * So, rmdir()->pre_destroy() can be called while we do this charge.
2940 * In that case, we need to call pre_destroy() again. check it here.
2942 cgroup_release_and_wakeup_rmdir(&mem->css);
2946 * A call to try to shrink memory usage on charge failure at shmem's swapin.
2947 * Calling hierarchical_reclaim is not enough because we should update
2948 * last_oom_jiffies to prevent pagefault_out_of_memory from invoking global OOM.
2949 * Moreover considering hierarchy, we should reclaim from the mem_over_limit,
2950 * not from the memcg which this page would be charged to.
2951 * try_charge_swapin does all of these works properly.
2953 int mem_cgroup_shmem_charge_fallback(struct page *page,
2954 struct mm_struct *mm,
2957 struct mem_cgroup *mem = NULL;
2960 if (mem_cgroup_disabled())
2963 ret = mem_cgroup_try_charge_swapin(mm, page, gfp_mask, &mem);
2965 mem_cgroup_cancel_charge_swapin(mem); /* it does !mem check */
2970 static DEFINE_MUTEX(set_limit_mutex);
2972 static int mem_cgroup_resize_limit(struct mem_cgroup *memcg,
2973 unsigned long long val)
2976 u64 memswlimit, memlimit;
2978 int children = mem_cgroup_count_children(memcg);
2979 u64 curusage, oldusage;
2983 * For keeping hierarchical_reclaim simple, how long we should retry
2984 * is depends on callers. We set our retry-count to be function
2985 * of # of children which we should visit in this loop.
2987 retry_count = MEM_CGROUP_RECLAIM_RETRIES * children;
2989 oldusage = res_counter_read_u64(&memcg->res, RES_USAGE);
2992 while (retry_count) {
2993 if (signal_pending(current)) {
2998 * Rather than hide all in some function, I do this in
2999 * open coded manner. You see what this really does.
3000 * We have to guarantee mem->res.limit < mem->memsw.limit.
3002 mutex_lock(&set_limit_mutex);
3003 memswlimit = res_counter_read_u64(&memcg->memsw, RES_LIMIT);
3004 if (memswlimit < val) {
3006 mutex_unlock(&set_limit_mutex);
3010 memlimit = res_counter_read_u64(&memcg->res, RES_LIMIT);
3014 ret = res_counter_set_limit(&memcg->res, val);
3016 if (memswlimit == val)
3017 memcg->memsw_is_minimum = true;
3019 memcg->memsw_is_minimum = false;
3021 mutex_unlock(&set_limit_mutex);
3026 mem_cgroup_hierarchical_reclaim(memcg, NULL, GFP_KERNEL,
3027 MEM_CGROUP_RECLAIM_SHRINK);
3028 curusage = res_counter_read_u64(&memcg->res, RES_USAGE);
3029 /* Usage is reduced ? */
3030 if (curusage >= oldusage)
3033 oldusage = curusage;
3035 if (!ret && enlarge)
3036 memcg_oom_recover(memcg);
3041 static int mem_cgroup_resize_memsw_limit(struct mem_cgroup *memcg,
3042 unsigned long long val)
3045 u64 memlimit, memswlimit, oldusage, curusage;
3046 int children = mem_cgroup_count_children(memcg);
3050 /* see mem_cgroup_resize_res_limit */
3051 retry_count = children * MEM_CGROUP_RECLAIM_RETRIES;
3052 oldusage = res_counter_read_u64(&memcg->memsw, RES_USAGE);
3053 while (retry_count) {
3054 if (signal_pending(current)) {
3059 * Rather than hide all in some function, I do this in
3060 * open coded manner. You see what this really does.
3061 * We have to guarantee mem->res.limit < mem->memsw.limit.
3063 mutex_lock(&set_limit_mutex);
3064 memlimit = res_counter_read_u64(&memcg->res, RES_LIMIT);
3065 if (memlimit > val) {
3067 mutex_unlock(&set_limit_mutex);
3070 memswlimit = res_counter_read_u64(&memcg->memsw, RES_LIMIT);
3071 if (memswlimit < val)
3073 ret = res_counter_set_limit(&memcg->memsw, val);
3075 if (memlimit == val)
3076 memcg->memsw_is_minimum = true;
3078 memcg->memsw_is_minimum = false;
3080 mutex_unlock(&set_limit_mutex);
3085 mem_cgroup_hierarchical_reclaim(memcg, NULL, GFP_KERNEL,
3086 MEM_CGROUP_RECLAIM_NOSWAP |
3087 MEM_CGROUP_RECLAIM_SHRINK);
3088 curusage = res_counter_read_u64(&memcg->memsw, RES_USAGE);
3089 /* Usage is reduced ? */
3090 if (curusage >= oldusage)
3093 oldusage = curusage;
3095 if (!ret && enlarge)
3096 memcg_oom_recover(memcg);
3100 unsigned long mem_cgroup_soft_limit_reclaim(struct zone *zone, int order,
3103 unsigned long nr_reclaimed = 0;
3104 struct mem_cgroup_per_zone *mz, *next_mz = NULL;
3105 unsigned long reclaimed;
3107 struct mem_cgroup_tree_per_zone *mctz;
3108 unsigned long long excess;
3113 mctz = soft_limit_tree_node_zone(zone_to_nid(zone), zone_idx(zone));
3115 * This loop can run a while, specially if mem_cgroup's continuously
3116 * keep exceeding their soft limit and putting the system under
3123 mz = mem_cgroup_largest_soft_limit_node(mctz);
3127 reclaimed = mem_cgroup_hierarchical_reclaim(mz->mem, zone,
3129 MEM_CGROUP_RECLAIM_SOFT);
3130 nr_reclaimed += reclaimed;
3131 spin_lock(&mctz->lock);
3134 * If we failed to reclaim anything from this memory cgroup
3135 * it is time to move on to the next cgroup
3141 * Loop until we find yet another one.
3143 * By the time we get the soft_limit lock
3144 * again, someone might have aded the
3145 * group back on the RB tree. Iterate to
3146 * make sure we get a different mem.
3147 * mem_cgroup_largest_soft_limit_node returns
3148 * NULL if no other cgroup is present on
3152 __mem_cgroup_largest_soft_limit_node(mctz);
3153 if (next_mz == mz) {
3154 css_put(&next_mz->mem->css);
3156 } else /* next_mz == NULL or other memcg */
3160 __mem_cgroup_remove_exceeded(mz->mem, mz, mctz);
3161 excess = res_counter_soft_limit_excess(&mz->mem->res);
3163 * One school of thought says that we should not add
3164 * back the node to the tree if reclaim returns 0.
3165 * But our reclaim could return 0, simply because due
3166 * to priority we are exposing a smaller subset of
3167 * memory to reclaim from. Consider this as a longer
3170 /* If excess == 0, no tree ops */
3171 __mem_cgroup_insert_exceeded(mz->mem, mz, mctz, excess);
3172 spin_unlock(&mctz->lock);
3173 css_put(&mz->mem->css);
3176 * Could not reclaim anything and there are no more
3177 * mem cgroups to try or we seem to be looping without
3178 * reclaiming anything.
3180 if (!nr_reclaimed &&
3182 loop > MEM_CGROUP_MAX_SOFT_LIMIT_RECLAIM_LOOPS))
3184 } while (!nr_reclaimed);
3186 css_put(&next_mz->mem->css);
3187 return nr_reclaimed;
3191 * This routine traverse page_cgroup in given list and drop them all.
3192 * *And* this routine doesn't reclaim page itself, just removes page_cgroup.
3194 static int mem_cgroup_force_empty_list(struct mem_cgroup *mem,
3195 int node, int zid, enum lru_list lru)
3198 struct mem_cgroup_per_zone *mz;
3199 struct page_cgroup *pc, *busy;
3200 unsigned long flags, loop;
3201 struct list_head *list;
3204 zone = &NODE_DATA(node)->node_zones[zid];
3205 mz = mem_cgroup_zoneinfo(mem, node, zid);
3206 list = &mz->lists[lru];
3208 loop = MEM_CGROUP_ZSTAT(mz, lru);
3209 /* give some margin against EBUSY etc...*/
3214 spin_lock_irqsave(&zone->lru_lock, flags);
3215 if (list_empty(list)) {
3216 spin_unlock_irqrestore(&zone->lru_lock, flags);
3219 pc = list_entry(list->prev, struct page_cgroup, lru);
3221 list_move(&pc->lru, list);
3223 spin_unlock_irqrestore(&zone->lru_lock, flags);
3226 spin_unlock_irqrestore(&zone->lru_lock, flags);
3228 ret = mem_cgroup_move_parent(pc, mem, GFP_KERNEL);
3232 if (ret == -EBUSY || ret == -EINVAL) {
3233 /* found lock contention or "pc" is obsolete. */
3240 if (!ret && !list_empty(list))
3246 * make mem_cgroup's charge to be 0 if there is no task.
3247 * This enables deleting this mem_cgroup.
3249 static int mem_cgroup_force_empty(struct mem_cgroup *mem, bool free_all)
3252 int node, zid, shrink;
3253 int nr_retries = MEM_CGROUP_RECLAIM_RETRIES;
3254 struct cgroup *cgrp = mem->css.cgroup;
3259 /* should free all ? */
3265 if (cgroup_task_count(cgrp) || !list_empty(&cgrp->children))
3268 if (signal_pending(current))
3270 /* This is for making all *used* pages to be on LRU. */
3271 lru_add_drain_all();
3272 drain_all_stock_sync();
3274 mem_cgroup_start_move(mem);
3275 for_each_node_state(node, N_HIGH_MEMORY) {
3276 for (zid = 0; !ret && zid < MAX_NR_ZONES; zid++) {
3279 ret = mem_cgroup_force_empty_list(mem,
3288 mem_cgroup_end_move(mem);
3289 memcg_oom_recover(mem);
3290 /* it seems parent cgroup doesn't have enough mem */
3294 /* "ret" should also be checked to ensure all lists are empty. */
3295 } while (mem->res.usage > 0 || ret);
3301 /* returns EBUSY if there is a task or if we come here twice. */
3302 if (cgroup_task_count(cgrp) || !list_empty(&cgrp->children) || shrink) {
3306 /* we call try-to-free pages for make this cgroup empty */
3307 lru_add_drain_all();
3308 /* try to free all pages in this cgroup */
3310 while (nr_retries && mem->res.usage > 0) {
3313 if (signal_pending(current)) {
3317 progress = try_to_free_mem_cgroup_pages(mem, GFP_KERNEL,
3318 false, get_swappiness(mem));
3321 /* maybe some writeback is necessary */
3322 congestion_wait(BLK_RW_ASYNC, HZ/10);
3327 /* try move_account...there may be some *locked* pages. */
3331 int mem_cgroup_force_empty_write(struct cgroup *cont, unsigned int event)
3333 return mem_cgroup_force_empty(mem_cgroup_from_cont(cont), true);
3337 static u64 mem_cgroup_hierarchy_read(struct cgroup *cont, struct cftype *cft)
3339 return mem_cgroup_from_cont(cont)->use_hierarchy;
3342 static int mem_cgroup_hierarchy_write(struct cgroup *cont, struct cftype *cft,
3346 struct mem_cgroup *mem = mem_cgroup_from_cont(cont);
3347 struct cgroup *parent = cont->parent;
3348 struct mem_cgroup *parent_mem = NULL;
3351 parent_mem = mem_cgroup_from_cont(parent);
3355 * If parent's use_hierarchy is set, we can't make any modifications
3356 * in the child subtrees. If it is unset, then the change can
3357 * occur, provided the current cgroup has no children.
3359 * For the root cgroup, parent_mem is NULL, we allow value to be
3360 * set if there are no children.
3362 if ((!parent_mem || !parent_mem->use_hierarchy) &&
3363 (val == 1 || val == 0)) {
3364 if (list_empty(&cont->children))
3365 mem->use_hierarchy = val;
3376 static u64 mem_cgroup_get_recursive_idx_stat(struct mem_cgroup *mem,
3377 enum mem_cgroup_stat_index idx)
3379 struct mem_cgroup *iter;
3382 /* each per cpu's value can be minus.Then, use s64 */
3383 for_each_mem_cgroup_tree(iter, mem)
3384 val += mem_cgroup_read_stat(iter, idx);
3386 if (val < 0) /* race ? */
3391 static inline u64 mem_cgroup_usage(struct mem_cgroup *mem, bool swap)
3395 if (!mem_cgroup_is_root(mem)) {
3397 return res_counter_read_u64(&mem->res, RES_USAGE);
3399 return res_counter_read_u64(&mem->memsw, RES_USAGE);
3402 val = mem_cgroup_get_recursive_idx_stat(mem, MEM_CGROUP_STAT_CACHE);
3403 val += mem_cgroup_get_recursive_idx_stat(mem, MEM_CGROUP_STAT_RSS);
3406 val += mem_cgroup_get_recursive_idx_stat(mem,
3407 MEM_CGROUP_STAT_SWAPOUT);
3409 return val << PAGE_SHIFT;
3412 static u64 mem_cgroup_read(struct cgroup *cont, struct cftype *cft)
3414 struct mem_cgroup *mem = mem_cgroup_from_cont(cont);
3418 type = MEMFILE_TYPE(cft->private);
3419 name = MEMFILE_ATTR(cft->private);
3422 if (name == RES_USAGE)
3423 val = mem_cgroup_usage(mem, false);
3425 val = res_counter_read_u64(&mem->res, name);
3428 if (name == RES_USAGE)
3429 val = mem_cgroup_usage(mem, true);
3431 val = res_counter_read_u64(&mem->memsw, name);
3440 * The user of this function is...
3443 static int mem_cgroup_write(struct cgroup *cont, struct cftype *cft,
3446 struct mem_cgroup *memcg = mem_cgroup_from_cont(cont);
3448 unsigned long long val;
3451 type = MEMFILE_TYPE(cft->private);
3452 name = MEMFILE_ATTR(cft->private);
3455 if (mem_cgroup_is_root(memcg)) { /* Can't set limit on root */
3459 /* This function does all necessary parse...reuse it */
3460 ret = res_counter_memparse_write_strategy(buffer, &val);
3464 ret = mem_cgroup_resize_limit(memcg, val);
3466 ret = mem_cgroup_resize_memsw_limit(memcg, val);
3468 case RES_SOFT_LIMIT:
3469 ret = res_counter_memparse_write_strategy(buffer, &val);
3473 * For memsw, soft limits are hard to implement in terms
3474 * of semantics, for now, we support soft limits for
3475 * control without swap
3478 ret = res_counter_set_soft_limit(&memcg->res, val);
3483 ret = -EINVAL; /* should be BUG() ? */
3489 static void memcg_get_hierarchical_limit(struct mem_cgroup *memcg,
3490 unsigned long long *mem_limit, unsigned long long *memsw_limit)
3492 struct cgroup *cgroup;
3493 unsigned long long min_limit, min_memsw_limit, tmp;
3495 min_limit = res_counter_read_u64(&memcg->res, RES_LIMIT);
3496 min_memsw_limit = res_counter_read_u64(&memcg->memsw, RES_LIMIT);
3497 cgroup = memcg->css.cgroup;
3498 if (!memcg->use_hierarchy)
3501 while (cgroup->parent) {
3502 cgroup = cgroup->parent;
3503 memcg = mem_cgroup_from_cont(cgroup);
3504 if (!memcg->use_hierarchy)
3506 tmp = res_counter_read_u64(&memcg->res, RES_LIMIT);
3507 min_limit = min(min_limit, tmp);
3508 tmp = res_counter_read_u64(&memcg->memsw, RES_LIMIT);
3509 min_memsw_limit = min(min_memsw_limit, tmp);
3512 *mem_limit = min_limit;
3513 *memsw_limit = min_memsw_limit;
3517 static int mem_cgroup_reset(struct cgroup *cont, unsigned int event)
3519 struct mem_cgroup *mem;
3522 mem = mem_cgroup_from_cont(cont);
3523 type = MEMFILE_TYPE(event);
3524 name = MEMFILE_ATTR(event);
3528 res_counter_reset_max(&mem->res);
3530 res_counter_reset_max(&mem->memsw);
3534 res_counter_reset_failcnt(&mem->res);
3536 res_counter_reset_failcnt(&mem->memsw);
3543 static u64 mem_cgroup_move_charge_read(struct cgroup *cgrp,
3546 return mem_cgroup_from_cont(cgrp)->move_charge_at_immigrate;
3550 static int mem_cgroup_move_charge_write(struct cgroup *cgrp,
3551 struct cftype *cft, u64 val)
3553 struct mem_cgroup *mem = mem_cgroup_from_cont(cgrp);
3555 if (val >= (1 << NR_MOVE_TYPE))
3558 * We check this value several times in both in can_attach() and
3559 * attach(), so we need cgroup lock to prevent this value from being
3563 mem->move_charge_at_immigrate = val;
3569 static int mem_cgroup_move_charge_write(struct cgroup *cgrp,
3570 struct cftype *cft, u64 val)
3577 /* For read statistics */
3593 struct mcs_total_stat {
3594 s64 stat[NR_MCS_STAT];
3600 } memcg_stat_strings[NR_MCS_STAT] = {
3601 {"cache", "total_cache"},
3602 {"rss", "total_rss"},
3603 {"mapped_file", "total_mapped_file"},
3604 {"pgpgin", "total_pgpgin"},
3605 {"pgpgout", "total_pgpgout"},
3606 {"swap", "total_swap"},
3607 {"inactive_anon", "total_inactive_anon"},
3608 {"active_anon", "total_active_anon"},
3609 {"inactive_file", "total_inactive_file"},
3610 {"active_file", "total_active_file"},
3611 {"unevictable", "total_unevictable"}
3616 mem_cgroup_get_local_stat(struct mem_cgroup *mem, struct mcs_total_stat *s)
3621 val = mem_cgroup_read_stat(mem, MEM_CGROUP_STAT_CACHE);
3622 s->stat[MCS_CACHE] += val * PAGE_SIZE;
3623 val = mem_cgroup_read_stat(mem, MEM_CGROUP_STAT_RSS);
3624 s->stat[MCS_RSS] += val * PAGE_SIZE;
3625 val = mem_cgroup_read_stat(mem, MEM_CGROUP_STAT_FILE_MAPPED);
3626 s->stat[MCS_FILE_MAPPED] += val * PAGE_SIZE;
3627 val = mem_cgroup_read_stat(mem, MEM_CGROUP_STAT_PGPGIN_COUNT);
3628 s->stat[MCS_PGPGIN] += val;
3629 val = mem_cgroup_read_stat(mem, MEM_CGROUP_STAT_PGPGOUT_COUNT);
3630 s->stat[MCS_PGPGOUT] += val;
3631 if (do_swap_account) {
3632 val = mem_cgroup_read_stat(mem, MEM_CGROUP_STAT_SWAPOUT);
3633 s->stat[MCS_SWAP] += val * PAGE_SIZE;
3637 val = mem_cgroup_get_local_zonestat(mem, LRU_INACTIVE_ANON);
3638 s->stat[MCS_INACTIVE_ANON] += val * PAGE_SIZE;
3639 val = mem_cgroup_get_local_zonestat(mem, LRU_ACTIVE_ANON);
3640 s->stat[MCS_ACTIVE_ANON] += val * PAGE_SIZE;
3641 val = mem_cgroup_get_local_zonestat(mem, LRU_INACTIVE_FILE);
3642 s->stat[MCS_INACTIVE_FILE] += val * PAGE_SIZE;
3643 val = mem_cgroup_get_local_zonestat(mem, LRU_ACTIVE_FILE);
3644 s->stat[MCS_ACTIVE_FILE] += val * PAGE_SIZE;
3645 val = mem_cgroup_get_local_zonestat(mem, LRU_UNEVICTABLE);
3646 s->stat[MCS_UNEVICTABLE] += val * PAGE_SIZE;
3650 mem_cgroup_get_total_stat(struct mem_cgroup *mem, struct mcs_total_stat *s)
3652 struct mem_cgroup *iter;
3654 for_each_mem_cgroup_tree(iter, mem)
3655 mem_cgroup_get_local_stat(iter, s);
3658 static int mem_control_stat_show(struct cgroup *cont, struct cftype *cft,
3659 struct cgroup_map_cb *cb)
3661 struct mem_cgroup *mem_cont = mem_cgroup_from_cont(cont);
3662 struct mcs_total_stat mystat;
3665 memset(&mystat, 0, sizeof(mystat));
3666 mem_cgroup_get_local_stat(mem_cont, &mystat);
3668 for (i = 0; i < NR_MCS_STAT; i++) {
3669 if (i == MCS_SWAP && !do_swap_account)
3671 cb->fill(cb, memcg_stat_strings[i].local_name, mystat.stat[i]);
3674 /* Hierarchical information */
3676 unsigned long long limit, memsw_limit;
3677 memcg_get_hierarchical_limit(mem_cont, &limit, &memsw_limit);
3678 cb->fill(cb, "hierarchical_memory_limit", limit);
3679 if (do_swap_account)
3680 cb->fill(cb, "hierarchical_memsw_limit", memsw_limit);
3683 memset(&mystat, 0, sizeof(mystat));
3684 mem_cgroup_get_total_stat(mem_cont, &mystat);
3685 for (i = 0; i < NR_MCS_STAT; i++) {
3686 if (i == MCS_SWAP && !do_swap_account)
3688 cb->fill(cb, memcg_stat_strings[i].total_name, mystat.stat[i]);
3691 #ifdef CONFIG_DEBUG_VM
3692 cb->fill(cb, "inactive_ratio", calc_inactive_ratio(mem_cont, NULL));
3696 struct mem_cgroup_per_zone *mz;
3697 unsigned long recent_rotated[2] = {0, 0};
3698 unsigned long recent_scanned[2] = {0, 0};
3700 for_each_online_node(nid)
3701 for (zid = 0; zid < MAX_NR_ZONES; zid++) {
3702 mz = mem_cgroup_zoneinfo(mem_cont, nid, zid);
3704 recent_rotated[0] +=
3705 mz->reclaim_stat.recent_rotated[0];
3706 recent_rotated[1] +=
3707 mz->reclaim_stat.recent_rotated[1];
3708 recent_scanned[0] +=
3709 mz->reclaim_stat.recent_scanned[0];
3710 recent_scanned[1] +=
3711 mz->reclaim_stat.recent_scanned[1];
3713 cb->fill(cb, "recent_rotated_anon", recent_rotated[0]);
3714 cb->fill(cb, "recent_rotated_file", recent_rotated[1]);
3715 cb->fill(cb, "recent_scanned_anon", recent_scanned[0]);
3716 cb->fill(cb, "recent_scanned_file", recent_scanned[1]);
3723 static u64 mem_cgroup_swappiness_read(struct cgroup *cgrp, struct cftype *cft)
3725 struct mem_cgroup *memcg = mem_cgroup_from_cont(cgrp);
3727 return get_swappiness(memcg);
3730 static int mem_cgroup_swappiness_write(struct cgroup *cgrp, struct cftype *cft,
3733 struct mem_cgroup *memcg = mem_cgroup_from_cont(cgrp);
3734 struct mem_cgroup *parent;
3739 if (cgrp->parent == NULL)
3742 parent = mem_cgroup_from_cont(cgrp->parent);
3746 /* If under hierarchy, only empty-root can set this value */
3747 if ((parent->use_hierarchy) ||
3748 (memcg->use_hierarchy && !list_empty(&cgrp->children))) {
3753 spin_lock(&memcg->reclaim_param_lock);
3754 memcg->swappiness = val;
3755 spin_unlock(&memcg->reclaim_param_lock);
3762 static void __mem_cgroup_threshold(struct mem_cgroup *memcg, bool swap)
3764 struct mem_cgroup_threshold_ary *t;
3770 t = rcu_dereference(memcg->thresholds.primary);
3772 t = rcu_dereference(memcg->memsw_thresholds.primary);
3777 usage = mem_cgroup_usage(memcg, swap);
3780 * current_threshold points to threshold just below usage.
3781 * If it's not true, a threshold was crossed after last
3782 * call of __mem_cgroup_threshold().
3784 i = t->current_threshold;
3787 * Iterate backward over array of thresholds starting from
3788 * current_threshold and check if a threshold is crossed.
3789 * If none of thresholds below usage is crossed, we read
3790 * only one element of the array here.
3792 for (; i >= 0 && unlikely(t->entries[i].threshold > usage); i--)
3793 eventfd_signal(t->entries[i].eventfd, 1);
3795 /* i = current_threshold + 1 */
3799 * Iterate forward over array of thresholds starting from
3800 * current_threshold+1 and check if a threshold is crossed.
3801 * If none of thresholds above usage is crossed, we read
3802 * only one element of the array here.
3804 for (; i < t->size && unlikely(t->entries[i].threshold <= usage); i++)
3805 eventfd_signal(t->entries[i].eventfd, 1);
3807 /* Update current_threshold */
3808 t->current_threshold = i - 1;
3813 static void mem_cgroup_threshold(struct mem_cgroup *memcg)
3816 __mem_cgroup_threshold(memcg, false);
3817 if (do_swap_account)
3818 __mem_cgroup_threshold(memcg, true);
3820 memcg = parent_mem_cgroup(memcg);
3824 static int compare_thresholds(const void *a, const void *b)
3826 const struct mem_cgroup_threshold *_a = a;
3827 const struct mem_cgroup_threshold *_b = b;
3829 return _a->threshold - _b->threshold;
3832 static int mem_cgroup_oom_notify_cb(struct mem_cgroup *mem)
3834 struct mem_cgroup_eventfd_list *ev;
3836 list_for_each_entry(ev, &mem->oom_notify, list)
3837 eventfd_signal(ev->eventfd, 1);
3841 static void mem_cgroup_oom_notify(struct mem_cgroup *mem)
3843 struct mem_cgroup *iter;
3845 for_each_mem_cgroup_tree(iter, mem)
3846 mem_cgroup_oom_notify_cb(iter);
3849 static int mem_cgroup_usage_register_event(struct cgroup *cgrp,
3850 struct cftype *cft, struct eventfd_ctx *eventfd, const char *args)
3852 struct mem_cgroup *memcg = mem_cgroup_from_cont(cgrp);
3853 struct mem_cgroup_thresholds *thresholds;
3854 struct mem_cgroup_threshold_ary *new;
3855 int type = MEMFILE_TYPE(cft->private);
3856 u64 threshold, usage;
3859 ret = res_counter_memparse_write_strategy(args, &threshold);
3863 mutex_lock(&memcg->thresholds_lock);
3866 thresholds = &memcg->thresholds;
3867 else if (type == _MEMSWAP)
3868 thresholds = &memcg->memsw_thresholds;
3872 usage = mem_cgroup_usage(memcg, type == _MEMSWAP);
3874 /* Check if a threshold crossed before adding a new one */
3875 if (thresholds->primary)
3876 __mem_cgroup_threshold(memcg, type == _MEMSWAP);
3878 size = thresholds->primary ? thresholds->primary->size + 1 : 1;
3880 /* Allocate memory for new array of thresholds */
3881 new = kmalloc(sizeof(*new) + size * sizeof(struct mem_cgroup_threshold),
3889 /* Copy thresholds (if any) to new array */
3890 if (thresholds->primary) {
3891 memcpy(new->entries, thresholds->primary->entries, (size - 1) *
3892 sizeof(struct mem_cgroup_threshold));
3895 /* Add new threshold */
3896 new->entries[size - 1].eventfd = eventfd;
3897 new->entries[size - 1].threshold = threshold;
3899 /* Sort thresholds. Registering of new threshold isn't time-critical */
3900 sort(new->entries, size, sizeof(struct mem_cgroup_threshold),
3901 compare_thresholds, NULL);
3903 /* Find current threshold */
3904 new->current_threshold = -1;
3905 for (i = 0; i < size; i++) {
3906 if (new->entries[i].threshold < usage) {
3908 * new->current_threshold will not be used until
3909 * rcu_assign_pointer(), so it's safe to increment
3912 ++new->current_threshold;
3916 /* Free old spare buffer and save old primary buffer as spare */
3917 kfree(thresholds->spare);
3918 thresholds->spare = thresholds->primary;
3920 rcu_assign_pointer(thresholds->primary, new);
3922 /* To be sure that nobody uses thresholds */
3926 mutex_unlock(&memcg->thresholds_lock);
3931 static void mem_cgroup_usage_unregister_event(struct cgroup *cgrp,
3932 struct cftype *cft, struct eventfd_ctx *eventfd)
3934 struct mem_cgroup *memcg = mem_cgroup_from_cont(cgrp);
3935 struct mem_cgroup_thresholds *thresholds;
3936 struct mem_cgroup_threshold_ary *new;
3937 int type = MEMFILE_TYPE(cft->private);
3941 mutex_lock(&memcg->thresholds_lock);
3943 thresholds = &memcg->thresholds;
3944 else if (type == _MEMSWAP)
3945 thresholds = &memcg->memsw_thresholds;
3950 * Something went wrong if we trying to unregister a threshold
3951 * if we don't have thresholds
3953 BUG_ON(!thresholds);
3955 usage = mem_cgroup_usage(memcg, type == _MEMSWAP);
3957 /* Check if a threshold crossed before removing */
3958 __mem_cgroup_threshold(memcg, type == _MEMSWAP);
3960 /* Calculate new number of threshold */
3962 for (i = 0; i < thresholds->primary->size; i++) {
3963 if (thresholds->primary->entries[i].eventfd != eventfd)
3967 new = thresholds->spare;
3969 /* Set thresholds array to NULL if we don't have thresholds */
3978 /* Copy thresholds and find current threshold */
3979 new->current_threshold = -1;
3980 for (i = 0, j = 0; i < thresholds->primary->size; i++) {
3981 if (thresholds->primary->entries[i].eventfd == eventfd)
3984 new->entries[j] = thresholds->primary->entries[i];
3985 if (new->entries[j].threshold < usage) {
3987 * new->current_threshold will not be used
3988 * until rcu_assign_pointer(), so it's safe to increment
3991 ++new->current_threshold;
3997 /* Swap primary and spare array */
3998 thresholds->spare = thresholds->primary;
3999 rcu_assign_pointer(thresholds->primary, new);
4001 /* To be sure that nobody uses thresholds */
4004 mutex_unlock(&memcg->thresholds_lock);
4007 static int mem_cgroup_oom_register_event(struct cgroup *cgrp,
4008 struct cftype *cft, struct eventfd_ctx *eventfd, const char *args)
4010 struct mem_cgroup *memcg = mem_cgroup_from_cont(cgrp);
4011 struct mem_cgroup_eventfd_list *event;
4012 int type = MEMFILE_TYPE(cft->private);
4014 BUG_ON(type != _OOM_TYPE);
4015 event = kmalloc(sizeof(*event), GFP_KERNEL);
4019 mutex_lock(&memcg_oom_mutex);
4021 event->eventfd = eventfd;
4022 list_add(&event->list, &memcg->oom_notify);
4024 /* already in OOM ? */
4025 if (atomic_read(&memcg->oom_lock))
4026 eventfd_signal(eventfd, 1);
4027 mutex_unlock(&memcg_oom_mutex);
4032 static void mem_cgroup_oom_unregister_event(struct cgroup *cgrp,
4033 struct cftype *cft, struct eventfd_ctx *eventfd)
4035 struct mem_cgroup *mem = mem_cgroup_from_cont(cgrp);
4036 struct mem_cgroup_eventfd_list *ev, *tmp;
4037 int type = MEMFILE_TYPE(cft->private);
4039 BUG_ON(type != _OOM_TYPE);
4041 mutex_lock(&memcg_oom_mutex);
4043 list_for_each_entry_safe(ev, tmp, &mem->oom_notify, list) {
4044 if (ev->eventfd == eventfd) {
4045 list_del(&ev->list);
4050 mutex_unlock(&memcg_oom_mutex);
4053 static int mem_cgroup_oom_control_read(struct cgroup *cgrp,
4054 struct cftype *cft, struct cgroup_map_cb *cb)
4056 struct mem_cgroup *mem = mem_cgroup_from_cont(cgrp);
4058 cb->fill(cb, "oom_kill_disable", mem->oom_kill_disable);
4060 if (atomic_read(&mem->oom_lock))
4061 cb->fill(cb, "under_oom", 1);
4063 cb->fill(cb, "under_oom", 0);
4067 static int mem_cgroup_oom_control_write(struct cgroup *cgrp,
4068 struct cftype *cft, u64 val)
4070 struct mem_cgroup *mem = mem_cgroup_from_cont(cgrp);
4071 struct mem_cgroup *parent;
4073 /* cannot set to root cgroup and only 0 and 1 are allowed */
4074 if (!cgrp->parent || !((val == 0) || (val == 1)))
4077 parent = mem_cgroup_from_cont(cgrp->parent);
4080 /* oom-kill-disable is a flag for subhierarchy. */
4081 if ((parent->use_hierarchy) ||
4082 (mem->use_hierarchy && !list_empty(&cgrp->children))) {
4086 mem->oom_kill_disable = val;
4088 memcg_oom_recover(mem);
4093 static struct cftype mem_cgroup_files[] = {
4095 .name = "usage_in_bytes",
4096 .private = MEMFILE_PRIVATE(_MEM, RES_USAGE),
4097 .read_u64 = mem_cgroup_read,
4098 .register_event = mem_cgroup_usage_register_event,
4099 .unregister_event = mem_cgroup_usage_unregister_event,
4102 .name = "max_usage_in_bytes",
4103 .private = MEMFILE_PRIVATE(_MEM, RES_MAX_USAGE),
4104 .trigger = mem_cgroup_reset,
4105 .read_u64 = mem_cgroup_read,
4108 .name = "limit_in_bytes",
4109 .private = MEMFILE_PRIVATE(_MEM, RES_LIMIT),
4110 .write_string = mem_cgroup_write,
4111 .read_u64 = mem_cgroup_read,
4114 .name = "soft_limit_in_bytes",
4115 .private = MEMFILE_PRIVATE(_MEM, RES_SOFT_LIMIT),
4116 .write_string = mem_cgroup_write,
4117 .read_u64 = mem_cgroup_read,
4121 .private = MEMFILE_PRIVATE(_MEM, RES_FAILCNT),
4122 .trigger = mem_cgroup_reset,
4123 .read_u64 = mem_cgroup_read,
4127 .read_map = mem_control_stat_show,
4130 .name = "force_empty",
4131 .trigger = mem_cgroup_force_empty_write,
4134 .name = "use_hierarchy",
4135 .write_u64 = mem_cgroup_hierarchy_write,
4136 .read_u64 = mem_cgroup_hierarchy_read,
4139 .name = "swappiness",
4140 .read_u64 = mem_cgroup_swappiness_read,
4141 .write_u64 = mem_cgroup_swappiness_write,
4144 .name = "move_charge_at_immigrate",
4145 .read_u64 = mem_cgroup_move_charge_read,
4146 .write_u64 = mem_cgroup_move_charge_write,
4149 .name = "oom_control",
4150 .read_map = mem_cgroup_oom_control_read,
4151 .write_u64 = mem_cgroup_oom_control_write,
4152 .register_event = mem_cgroup_oom_register_event,
4153 .unregister_event = mem_cgroup_oom_unregister_event,
4154 .private = MEMFILE_PRIVATE(_OOM_TYPE, OOM_CONTROL),
4158 #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP
4159 static struct cftype memsw_cgroup_files[] = {
4161 .name = "memsw.usage_in_bytes",
4162 .private = MEMFILE_PRIVATE(_MEMSWAP, RES_USAGE),
4163 .read_u64 = mem_cgroup_read,
4164 .register_event = mem_cgroup_usage_register_event,
4165 .unregister_event = mem_cgroup_usage_unregister_event,
4168 .name = "memsw.max_usage_in_bytes",
4169 .private = MEMFILE_PRIVATE(_MEMSWAP, RES_MAX_USAGE),
4170 .trigger = mem_cgroup_reset,
4171 .read_u64 = mem_cgroup_read,
4174 .name = "memsw.limit_in_bytes",
4175 .private = MEMFILE_PRIVATE(_MEMSWAP, RES_LIMIT),
4176 .write_string = mem_cgroup_write,
4177 .read_u64 = mem_cgroup_read,
4180 .name = "memsw.failcnt",
4181 .private = MEMFILE_PRIVATE(_MEMSWAP, RES_FAILCNT),
4182 .trigger = mem_cgroup_reset,
4183 .read_u64 = mem_cgroup_read,
4187 static int register_memsw_files(struct cgroup *cont, struct cgroup_subsys *ss)
4189 if (!do_swap_account)
4191 return cgroup_add_files(cont, ss, memsw_cgroup_files,
4192 ARRAY_SIZE(memsw_cgroup_files));
4195 static int register_memsw_files(struct cgroup *cont, struct cgroup_subsys *ss)
4201 static int alloc_mem_cgroup_per_zone_info(struct mem_cgroup *mem, int node)
4203 struct mem_cgroup_per_node *pn;
4204 struct mem_cgroup_per_zone *mz;
4206 int zone, tmp = node;
4208 * This routine is called against possible nodes.
4209 * But it's BUG to call kmalloc() against offline node.
4211 * TODO: this routine can waste much memory for nodes which will
4212 * never be onlined. It's better to use memory hotplug callback
4215 if (!node_state(node, N_NORMAL_MEMORY))
4217 pn = kmalloc_node(sizeof(*pn), GFP_KERNEL, tmp);
4221 mem->info.nodeinfo[node] = pn;
4222 memset(pn, 0, sizeof(*pn));
4224 for (zone = 0; zone < MAX_NR_ZONES; zone++) {
4225 mz = &pn->zoneinfo[zone];
4227 INIT_LIST_HEAD(&mz->lists[l]);
4228 mz->usage_in_excess = 0;
4229 mz->on_tree = false;
4235 static void free_mem_cgroup_per_zone_info(struct mem_cgroup *mem, int node)
4237 kfree(mem->info.nodeinfo[node]);
4240 static struct mem_cgroup *mem_cgroup_alloc(void)
4242 struct mem_cgroup *mem;
4243 int size = sizeof(struct mem_cgroup);
4245 /* Can be very big if MAX_NUMNODES is very big */
4246 if (size < PAGE_SIZE)
4247 mem = kmalloc(size, GFP_KERNEL);
4249 mem = vmalloc(size);
4254 memset(mem, 0, size);
4255 mem->stat = alloc_percpu(struct mem_cgroup_stat_cpu);
4258 spin_lock_init(&mem->pcp_counter_lock);
4262 if (size < PAGE_SIZE)
4270 * At destroying mem_cgroup, references from swap_cgroup can remain.
4271 * (scanning all at force_empty is too costly...)
4273 * Instead of clearing all references at force_empty, we remember
4274 * the number of reference from swap_cgroup and free mem_cgroup when
4275 * it goes down to 0.
4277 * Removal of cgroup itself succeeds regardless of refs from swap.
4280 static void __mem_cgroup_free(struct mem_cgroup *mem)
4284 mem_cgroup_remove_from_trees(mem);
4285 free_css_id(&mem_cgroup_subsys, &mem->css);
4287 for_each_node_state(node, N_POSSIBLE)
4288 free_mem_cgroup_per_zone_info(mem, node);
4290 free_percpu(mem->stat);
4291 if (sizeof(struct mem_cgroup) < PAGE_SIZE)
4297 static void mem_cgroup_get(struct mem_cgroup *mem)
4299 atomic_inc(&mem->refcnt);
4302 static void __mem_cgroup_put(struct mem_cgroup *mem, int count)
4304 if (atomic_sub_and_test(count, &mem->refcnt)) {
4305 struct mem_cgroup *parent = parent_mem_cgroup(mem);
4306 __mem_cgroup_free(mem);
4308 mem_cgroup_put(parent);
4312 static void mem_cgroup_put(struct mem_cgroup *mem)
4314 __mem_cgroup_put(mem, 1);
4318 * Returns the parent mem_cgroup in memcgroup hierarchy with hierarchy enabled.
4320 static struct mem_cgroup *parent_mem_cgroup(struct mem_cgroup *mem)
4322 if (!mem->res.parent)
4324 return mem_cgroup_from_res_counter(mem->res.parent, res);
4327 #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP
4328 static void __init enable_swap_cgroup(void)
4330 if (!mem_cgroup_disabled() && really_do_swap_account)
4331 do_swap_account = 1;
4334 static void __init enable_swap_cgroup(void)
4339 static int mem_cgroup_soft_limit_tree_init(void)
4341 struct mem_cgroup_tree_per_node *rtpn;
4342 struct mem_cgroup_tree_per_zone *rtpz;
4343 int tmp, node, zone;
4345 for_each_node_state(node, N_POSSIBLE) {
4347 if (!node_state(node, N_NORMAL_MEMORY))
4349 rtpn = kzalloc_node(sizeof(*rtpn), GFP_KERNEL, tmp);
4353 soft_limit_tree.rb_tree_per_node[node] = rtpn;
4355 for (zone = 0; zone < MAX_NR_ZONES; zone++) {
4356 rtpz = &rtpn->rb_tree_per_zone[zone];
4357 rtpz->rb_root = RB_ROOT;
4358 spin_lock_init(&rtpz->lock);
4364 static struct cgroup_subsys_state * __ref
4365 mem_cgroup_create(struct cgroup_subsys *ss, struct cgroup *cont)
4367 struct mem_cgroup *mem, *parent;
4368 long error = -ENOMEM;
4371 mem = mem_cgroup_alloc();
4373 return ERR_PTR(error);
4375 for_each_node_state(node, N_POSSIBLE)
4376 if (alloc_mem_cgroup_per_zone_info(mem, node))
4380 if (cont->parent == NULL) {
4382 enable_swap_cgroup();
4384 root_mem_cgroup = mem;
4385 if (mem_cgroup_soft_limit_tree_init())
4387 for_each_possible_cpu(cpu) {
4388 struct memcg_stock_pcp *stock =
4389 &per_cpu(memcg_stock, cpu);
4390 INIT_WORK(&stock->work, drain_local_stock);
4392 hotcpu_notifier(memcg_cpu_hotplug_callback, 0);
4394 parent = mem_cgroup_from_cont(cont->parent);
4395 mem->use_hierarchy = parent->use_hierarchy;
4396 mem->oom_kill_disable = parent->oom_kill_disable;
4399 if (parent && parent->use_hierarchy) {
4400 res_counter_init(&mem->res, &parent->res);
4401 res_counter_init(&mem->memsw, &parent->memsw);
4403 * We increment refcnt of the parent to ensure that we can
4404 * safely access it on res_counter_charge/uncharge.
4405 * This refcnt will be decremented when freeing this
4406 * mem_cgroup(see mem_cgroup_put).
4408 mem_cgroup_get(parent);
4410 res_counter_init(&mem->res, NULL);
4411 res_counter_init(&mem->memsw, NULL);
4413 mem->last_scanned_child = 0;
4414 spin_lock_init(&mem->reclaim_param_lock);
4415 INIT_LIST_HEAD(&mem->oom_notify);
4418 mem->swappiness = get_swappiness(parent);
4419 atomic_set(&mem->refcnt, 1);
4420 mem->move_charge_at_immigrate = 0;
4421 mutex_init(&mem->thresholds_lock);
4424 __mem_cgroup_free(mem);
4425 root_mem_cgroup = NULL;
4426 return ERR_PTR(error);
4429 static int mem_cgroup_pre_destroy(struct cgroup_subsys *ss,
4430 struct cgroup *cont)
4432 struct mem_cgroup *mem = mem_cgroup_from_cont(cont);
4434 return mem_cgroup_force_empty(mem, false);
4437 static void mem_cgroup_destroy(struct cgroup_subsys *ss,
4438 struct cgroup *cont)
4440 struct mem_cgroup *mem = mem_cgroup_from_cont(cont);
4442 mem_cgroup_put(mem);
4445 static int mem_cgroup_populate(struct cgroup_subsys *ss,
4446 struct cgroup *cont)
4450 ret = cgroup_add_files(cont, ss, mem_cgroup_files,
4451 ARRAY_SIZE(mem_cgroup_files));
4454 ret = register_memsw_files(cont, ss);
4459 /* Handlers for move charge at task migration. */
4460 #define PRECHARGE_COUNT_AT_ONCE 256
4461 static int mem_cgroup_do_precharge(unsigned long count)
4464 int batch_count = PRECHARGE_COUNT_AT_ONCE;
4465 struct mem_cgroup *mem = mc.to;
4467 if (mem_cgroup_is_root(mem)) {
4468 mc.precharge += count;
4469 /* we don't need css_get for root */
4472 /* try to charge at once */
4474 struct res_counter *dummy;
4476 * "mem" cannot be under rmdir() because we've already checked
4477 * by cgroup_lock_live_cgroup() that it is not removed and we
4478 * are still under the same cgroup_mutex. So we can postpone
4481 if (res_counter_charge(&mem->res, PAGE_SIZE * count, &dummy))
4483 if (do_swap_account && res_counter_charge(&mem->memsw,
4484 PAGE_SIZE * count, &dummy)) {
4485 res_counter_uncharge(&mem->res, PAGE_SIZE * count);
4488 mc.precharge += count;
4492 /* fall back to one by one charge */
4494 if (signal_pending(current)) {
4498 if (!batch_count--) {
4499 batch_count = PRECHARGE_COUNT_AT_ONCE;
4502 ret = __mem_cgroup_try_charge(NULL, GFP_KERNEL, &mem, false,
4505 /* mem_cgroup_clear_mc() will do uncharge later */
4513 * is_target_pte_for_mc - check a pte whether it is valid for move charge
4514 * @vma: the vma the pte to be checked belongs
4515 * @addr: the address corresponding to the pte to be checked
4516 * @ptent: the pte to be checked
4517 * @target: the pointer the target page or swap ent will be stored(can be NULL)
4520 * 0(MC_TARGET_NONE): if the pte is not a target for move charge.
4521 * 1(MC_TARGET_PAGE): if the page corresponding to this pte is a target for
4522 * move charge. if @target is not NULL, the page is stored in target->page
4523 * with extra refcnt got(Callers should handle it).
4524 * 2(MC_TARGET_SWAP): if the swap entry corresponding to this pte is a
4525 * target for charge migration. if @target is not NULL, the entry is stored
4528 * Called with pte lock held.
4535 enum mc_target_type {
4536 MC_TARGET_NONE, /* not used */
4541 static struct page *mc_handle_present_pte(struct vm_area_struct *vma,
4542 unsigned long addr, pte_t ptent)
4544 struct page *page = vm_normal_page(vma, addr, ptent);
4546 if (!page || !page_mapped(page))
4548 if (PageAnon(page)) {
4549 /* we don't move shared anon */
4550 if (!move_anon() || page_mapcount(page) > 2)
4552 } else if (!move_file())
4553 /* we ignore mapcount for file pages */
4555 if (!get_page_unless_zero(page))
4561 static struct page *mc_handle_swap_pte(struct vm_area_struct *vma,
4562 unsigned long addr, pte_t ptent, swp_entry_t *entry)
4565 struct page *page = NULL;
4566 swp_entry_t ent = pte_to_swp_entry(ptent);
4568 if (!move_anon() || non_swap_entry(ent))
4570 usage_count = mem_cgroup_count_swap_user(ent, &page);
4571 if (usage_count > 1) { /* we don't move shared anon */
4576 if (do_swap_account)
4577 entry->val = ent.val;
4582 static struct page *mc_handle_file_pte(struct vm_area_struct *vma,
4583 unsigned long addr, pte_t ptent, swp_entry_t *entry)
4585 struct page *page = NULL;
4586 struct inode *inode;
4587 struct address_space *mapping;
4590 if (!vma->vm_file) /* anonymous vma */
4595 inode = vma->vm_file->f_path.dentry->d_inode;
4596 mapping = vma->vm_file->f_mapping;
4597 if (pte_none(ptent))
4598 pgoff = linear_page_index(vma, addr);
4599 else /* pte_file(ptent) is true */
4600 pgoff = pte_to_pgoff(ptent);
4602 /* page is moved even if it's not RSS of this task(page-faulted). */
4603 if (!mapping_cap_swap_backed(mapping)) { /* normal file */
4604 page = find_get_page(mapping, pgoff);
4605 } else { /* shmem/tmpfs file. we should take account of swap too. */
4607 mem_cgroup_get_shmem_target(inode, pgoff, &page, &ent);
4608 if (do_swap_account)
4609 entry->val = ent.val;
4615 static int is_target_pte_for_mc(struct vm_area_struct *vma,
4616 unsigned long addr, pte_t ptent, union mc_target *target)
4618 struct page *page = NULL;
4619 struct page_cgroup *pc;
4621 swp_entry_t ent = { .val = 0 };
4623 if (pte_present(ptent))
4624 page = mc_handle_present_pte(vma, addr, ptent);
4625 else if (is_swap_pte(ptent))
4626 page = mc_handle_swap_pte(vma, addr, ptent, &ent);
4627 else if (pte_none(ptent) || pte_file(ptent))
4628 page = mc_handle_file_pte(vma, addr, ptent, &ent);
4630 if (!page && !ent.val)
4633 pc = lookup_page_cgroup(page);
4635 * Do only loose check w/o page_cgroup lock.
4636 * mem_cgroup_move_account() checks the pc is valid or not under
4639 if (PageCgroupUsed(pc) && pc->mem_cgroup == mc.from) {
4640 ret = MC_TARGET_PAGE;
4642 target->page = page;
4644 if (!ret || !target)
4647 /* There is a swap entry and a page doesn't exist or isn't charged */
4648 if (ent.val && !ret &&
4649 css_id(&mc.from->css) == lookup_swap_cgroup(ent)) {
4650 ret = MC_TARGET_SWAP;
4657 static int mem_cgroup_count_precharge_pte_range(pmd_t *pmd,
4658 unsigned long addr, unsigned long end,
4659 struct mm_walk *walk)
4661 struct vm_area_struct *vma = walk->private;
4665 VM_BUG_ON(pmd_trans_huge(*pmd));
4666 pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl);
4667 for (; addr != end; pte++, addr += PAGE_SIZE)
4668 if (is_target_pte_for_mc(vma, addr, *pte, NULL))
4669 mc.precharge++; /* increment precharge temporarily */
4670 pte_unmap_unlock(pte - 1, ptl);
4676 static unsigned long mem_cgroup_count_precharge(struct mm_struct *mm)
4678 unsigned long precharge;
4679 struct vm_area_struct *vma;
4681 /* We've already held the mmap_sem */
4682 for (vma = mm->mmap; vma; vma = vma->vm_next) {
4683 struct mm_walk mem_cgroup_count_precharge_walk = {
4684 .pmd_entry = mem_cgroup_count_precharge_pte_range,
4688 if (is_vm_hugetlb_page(vma))
4690 walk_page_range(vma->vm_start, vma->vm_end,
4691 &mem_cgroup_count_precharge_walk);
4694 precharge = mc.precharge;
4700 static int mem_cgroup_precharge_mc(struct mm_struct *mm)
4702 return mem_cgroup_do_precharge(mem_cgroup_count_precharge(mm));
4705 static void mem_cgroup_clear_mc(void)
4707 struct mem_cgroup *from = mc.from;
4708 struct mem_cgroup *to = mc.to;
4710 /* we must uncharge all the leftover precharges from mc.to */
4712 __mem_cgroup_cancel_charge(mc.to, mc.precharge);
4716 * we didn't uncharge from mc.from at mem_cgroup_move_account(), so
4717 * we must uncharge here.
4719 if (mc.moved_charge) {
4720 __mem_cgroup_cancel_charge(mc.from, mc.moved_charge);
4721 mc.moved_charge = 0;
4723 /* we must fixup refcnts and charges */
4724 if (mc.moved_swap) {
4725 /* uncharge swap account from the old cgroup */
4726 if (!mem_cgroup_is_root(mc.from))
4727 res_counter_uncharge(&mc.from->memsw,
4728 PAGE_SIZE * mc.moved_swap);
4729 __mem_cgroup_put(mc.from, mc.moved_swap);
4731 if (!mem_cgroup_is_root(mc.to)) {
4733 * we charged both to->res and to->memsw, so we should
4736 res_counter_uncharge(&mc.to->res,
4737 PAGE_SIZE * mc.moved_swap);
4739 /* we've already done mem_cgroup_get(mc.to) */
4744 up_read(&mc.mm->mmap_sem);
4747 spin_lock(&mc.lock);
4750 spin_unlock(&mc.lock);
4751 mc.moving_task = NULL;
4753 mem_cgroup_end_move(from);
4754 memcg_oom_recover(from);
4755 memcg_oom_recover(to);
4756 wake_up_all(&mc.waitq);
4759 static int mem_cgroup_can_attach(struct cgroup_subsys *ss,
4760 struct cgroup *cgroup,
4761 struct task_struct *p,
4765 struct mem_cgroup *mem = mem_cgroup_from_cont(cgroup);
4767 if (mem->move_charge_at_immigrate) {
4768 struct mm_struct *mm;
4769 struct mem_cgroup *from = mem_cgroup_from_task(p);
4771 VM_BUG_ON(from == mem);
4773 mm = get_task_mm(p);
4776 /* We move charges only when we move a owner of the mm */
4777 if (mm->owner == p) {
4779 * We do all the move charge works under one mmap_sem to
4780 * avoid deadlock with down_write(&mmap_sem)
4781 * -> try_charge() -> if (mc.moving_task) -> sleep.
4783 down_read(&mm->mmap_sem);
4787 VM_BUG_ON(mc.precharge);
4788 VM_BUG_ON(mc.moved_charge);
4789 VM_BUG_ON(mc.moved_swap);
4790 VM_BUG_ON(mc.moving_task);
4793 mem_cgroup_start_move(from);
4794 spin_lock(&mc.lock);
4798 mc.moved_charge = 0;
4800 spin_unlock(&mc.lock);
4801 mc.moving_task = current;
4804 ret = mem_cgroup_precharge_mc(mm);
4806 mem_cgroup_clear_mc();
4807 /* We call up_read() and mmput() in clear_mc(). */
4814 static void mem_cgroup_cancel_attach(struct cgroup_subsys *ss,
4815 struct cgroup *cgroup,
4816 struct task_struct *p,
4819 mem_cgroup_clear_mc();
4822 static int mem_cgroup_move_charge_pte_range(pmd_t *pmd,
4823 unsigned long addr, unsigned long end,
4824 struct mm_walk *walk)
4827 struct vm_area_struct *vma = walk->private;
4832 VM_BUG_ON(pmd_trans_huge(*pmd));
4833 pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl);
4834 for (; addr != end; addr += PAGE_SIZE) {
4835 pte_t ptent = *(pte++);
4836 union mc_target target;
4839 struct page_cgroup *pc;
4845 type = is_target_pte_for_mc(vma, addr, ptent, &target);
4847 case MC_TARGET_PAGE:
4849 if (isolate_lru_page(page))
4851 pc = lookup_page_cgroup(page);
4852 if (!mem_cgroup_move_account(pc,
4853 mc.from, mc.to, false)) {
4855 /* we uncharge from mc.from later. */
4858 putback_lru_page(page);
4859 put: /* is_target_pte_for_mc() gets the page */
4862 case MC_TARGET_SWAP:
4864 if (!mem_cgroup_move_swap_account(ent,
4865 mc.from, mc.to, false)) {
4867 /* we fixup refcnts and charges later. */
4875 pte_unmap_unlock(pte - 1, ptl);
4880 * We have consumed all precharges we got in can_attach().
4881 * We try charge one by one, but don't do any additional
4882 * charges to mc.to if we have failed in charge once in attach()
4885 ret = mem_cgroup_do_precharge(1);
4893 static void mem_cgroup_move_charge(struct mm_struct *mm)
4895 struct vm_area_struct *vma;
4897 lru_add_drain_all();
4898 /* We've already held the mmap_sem */
4899 for (vma = mm->mmap; vma; vma = vma->vm_next) {
4901 struct mm_walk mem_cgroup_move_charge_walk = {
4902 .pmd_entry = mem_cgroup_move_charge_pte_range,
4906 if (is_vm_hugetlb_page(vma))
4908 ret = walk_page_range(vma->vm_start, vma->vm_end,
4909 &mem_cgroup_move_charge_walk);
4912 * means we have consumed all precharges and failed in
4913 * doing additional charge. Just abandon here.
4919 static void mem_cgroup_move_task(struct cgroup_subsys *ss,
4920 struct cgroup *cont,
4921 struct cgroup *old_cont,
4922 struct task_struct *p,
4926 /* no need to move charge */
4929 mem_cgroup_move_charge(mc.mm);
4930 mem_cgroup_clear_mc();
4932 #else /* !CONFIG_MMU */
4933 static int mem_cgroup_can_attach(struct cgroup_subsys *ss,
4934 struct cgroup *cgroup,
4935 struct task_struct *p,
4940 static void mem_cgroup_cancel_attach(struct cgroup_subsys *ss,
4941 struct cgroup *cgroup,
4942 struct task_struct *p,
4946 static void mem_cgroup_move_task(struct cgroup_subsys *ss,
4947 struct cgroup *cont,
4948 struct cgroup *old_cont,
4949 struct task_struct *p,
4955 struct cgroup_subsys mem_cgroup_subsys = {
4957 .subsys_id = mem_cgroup_subsys_id,
4958 .create = mem_cgroup_create,
4959 .pre_destroy = mem_cgroup_pre_destroy,
4960 .destroy = mem_cgroup_destroy,
4961 .populate = mem_cgroup_populate,
4962 .can_attach = mem_cgroup_can_attach,
4963 .cancel_attach = mem_cgroup_cancel_attach,
4964 .attach = mem_cgroup_move_task,
4969 #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP
4970 static int __init enable_swap_account(char *s)
4972 /* consider enabled if no parameter or 1 is given */
4973 if (!s || !strcmp(s, "1"))
4974 really_do_swap_account = 1;
4975 else if (!strcmp(s, "0"))
4976 really_do_swap_account = 0;
4979 __setup("swapaccount", enable_swap_account);
4981 static int __init disable_swap_account(char *s)
4983 enable_swap_account("0");
4986 __setup("noswapaccount", disable_swap_account);