memsw: handle swapaccount kernel parameter correctly
[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / mm / memcontrol.c
blob44f9f9c89f0c7c8b706fd87118932b512977e9a3
1 /* memcontrol.c - Memory Controller
3 * Copyright IBM Corporation, 2007
4 * Author Balbir Singh <balbir@linux.vnet.ibm.com>
6 * Copyright 2007 OpenVZ SWsoft Inc
7 * Author: Pavel Emelianov <xemul@openvz.org>
9 * Memory thresholds
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>
27 #include <linux/mm.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>
44 #include <linux/fs.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>
51 #include "internal.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;
68 #else
69 static int really_do_swap_account __initdata = 0;
70 #endif
72 #else
73 #define do_swap_account (0)
74 #endif
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*/
125 bool on_tree;
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;
147 spinlock_t lock;
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;
162 u64 threshold;
165 /* For threshold */
166 struct mem_cgroup_threshold_ary {
167 /* An array index points to threshold just below usage. */
168 int current_threshold;
169 /* Size of entries[] */
170 unsigned int size;
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;
186 /* for OOM */
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.
206 struct mem_cgroup {
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
229 * reclaimed from.
231 int last_scanned_child;
233 * Should the accounting and control be hierarchical, per subtree?
235 bool use_hierarchy;
236 atomic_t oom_lock;
237 atomic_t refcnt;
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;
264 * percpu counter.
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.
280 enum move_type {
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 */
283 NR_MOVE_TYPE,
286 /* "mc" and its members are protected by cgroup_mutex */
287 static struct move_charge_struct {
288 spinlock_t lock; /* for from, to */
289 struct mem_cgroup *from;
290 struct mem_cgroup *to;
291 unsigned long precharge;
292 unsigned long moved_charge;
293 unsigned long moved_swap;
294 struct task_struct *moving_task; /* a task moving charges */
295 wait_queue_head_t waitq; /* a waitq for other context */
296 } mc = {
297 .lock = __SPIN_LOCK_UNLOCKED(mc.lock),
298 .waitq = __WAIT_QUEUE_HEAD_INITIALIZER(mc.waitq),
301 static bool move_anon(void)
303 return test_bit(MOVE_CHARGE_TYPE_ANON,
304 &mc.to->move_charge_at_immigrate);
307 static bool move_file(void)
309 return test_bit(MOVE_CHARGE_TYPE_FILE,
310 &mc.to->move_charge_at_immigrate);
314 * Maximum loops in mem_cgroup_hierarchical_reclaim(), used for soft
315 * limit reclaim to prevent infinite loops, if they ever occur.
317 #define MEM_CGROUP_MAX_RECLAIM_LOOPS (100)
318 #define MEM_CGROUP_MAX_SOFT_LIMIT_RECLAIM_LOOPS (2)
320 enum charge_type {
321 MEM_CGROUP_CHARGE_TYPE_CACHE = 0,
322 MEM_CGROUP_CHARGE_TYPE_MAPPED,
323 MEM_CGROUP_CHARGE_TYPE_SHMEM, /* used by page migration of shmem */
324 MEM_CGROUP_CHARGE_TYPE_FORCE, /* used by force_empty */
325 MEM_CGROUP_CHARGE_TYPE_SWAPOUT, /* for accounting swapcache */
326 MEM_CGROUP_CHARGE_TYPE_DROP, /* a page was unused swap cache */
327 NR_CHARGE_TYPE,
330 /* only for here (for easy reading.) */
331 #define PCGF_CACHE (1UL << PCG_CACHE)
332 #define PCGF_USED (1UL << PCG_USED)
333 #define PCGF_LOCK (1UL << PCG_LOCK)
334 /* Not used, but added here for completeness */
335 #define PCGF_ACCT (1UL << PCG_ACCT)
337 /* for encoding cft->private value on file */
338 #define _MEM (0)
339 #define _MEMSWAP (1)
340 #define _OOM_TYPE (2)
341 #define MEMFILE_PRIVATE(x, val) (((x) << 16) | (val))
342 #define MEMFILE_TYPE(val) (((val) >> 16) & 0xffff)
343 #define MEMFILE_ATTR(val) ((val) & 0xffff)
344 /* Used for OOM nofiier */
345 #define OOM_CONTROL (0)
348 * Reclaim flags for mem_cgroup_hierarchical_reclaim
350 #define MEM_CGROUP_RECLAIM_NOSWAP_BIT 0x0
351 #define MEM_CGROUP_RECLAIM_NOSWAP (1 << MEM_CGROUP_RECLAIM_NOSWAP_BIT)
352 #define MEM_CGROUP_RECLAIM_SHRINK_BIT 0x1
353 #define MEM_CGROUP_RECLAIM_SHRINK (1 << MEM_CGROUP_RECLAIM_SHRINK_BIT)
354 #define MEM_CGROUP_RECLAIM_SOFT_BIT 0x2
355 #define MEM_CGROUP_RECLAIM_SOFT (1 << MEM_CGROUP_RECLAIM_SOFT_BIT)
357 static void mem_cgroup_get(struct mem_cgroup *mem);
358 static void mem_cgroup_put(struct mem_cgroup *mem);
359 static struct mem_cgroup *parent_mem_cgroup(struct mem_cgroup *mem);
360 static void drain_all_stock_async(void);
362 static struct mem_cgroup_per_zone *
363 mem_cgroup_zoneinfo(struct mem_cgroup *mem, int nid, int zid)
365 return &mem->info.nodeinfo[nid]->zoneinfo[zid];
368 struct cgroup_subsys_state *mem_cgroup_css(struct mem_cgroup *mem)
370 return &mem->css;
373 static struct mem_cgroup_per_zone *
374 page_cgroup_zoneinfo(struct page_cgroup *pc)
376 struct mem_cgroup *mem = pc->mem_cgroup;
377 int nid = page_cgroup_nid(pc);
378 int zid = page_cgroup_zid(pc);
380 if (!mem)
381 return NULL;
383 return mem_cgroup_zoneinfo(mem, nid, zid);
386 static struct mem_cgroup_tree_per_zone *
387 soft_limit_tree_node_zone(int nid, int zid)
389 return &soft_limit_tree.rb_tree_per_node[nid]->rb_tree_per_zone[zid];
392 static struct mem_cgroup_tree_per_zone *
393 soft_limit_tree_from_page(struct page *page)
395 int nid = page_to_nid(page);
396 int zid = page_zonenum(page);
398 return &soft_limit_tree.rb_tree_per_node[nid]->rb_tree_per_zone[zid];
401 static void
402 __mem_cgroup_insert_exceeded(struct mem_cgroup *mem,
403 struct mem_cgroup_per_zone *mz,
404 struct mem_cgroup_tree_per_zone *mctz,
405 unsigned long long new_usage_in_excess)
407 struct rb_node **p = &mctz->rb_root.rb_node;
408 struct rb_node *parent = NULL;
409 struct mem_cgroup_per_zone *mz_node;
411 if (mz->on_tree)
412 return;
414 mz->usage_in_excess = new_usage_in_excess;
415 if (!mz->usage_in_excess)
416 return;
417 while (*p) {
418 parent = *p;
419 mz_node = rb_entry(parent, struct mem_cgroup_per_zone,
420 tree_node);
421 if (mz->usage_in_excess < mz_node->usage_in_excess)
422 p = &(*p)->rb_left;
424 * We can't avoid mem cgroups that are over their soft
425 * limit by the same amount
427 else if (mz->usage_in_excess >= mz_node->usage_in_excess)
428 p = &(*p)->rb_right;
430 rb_link_node(&mz->tree_node, parent, p);
431 rb_insert_color(&mz->tree_node, &mctz->rb_root);
432 mz->on_tree = true;
435 static void
436 __mem_cgroup_remove_exceeded(struct mem_cgroup *mem,
437 struct mem_cgroup_per_zone *mz,
438 struct mem_cgroup_tree_per_zone *mctz)
440 if (!mz->on_tree)
441 return;
442 rb_erase(&mz->tree_node, &mctz->rb_root);
443 mz->on_tree = false;
446 static void
447 mem_cgroup_remove_exceeded(struct mem_cgroup *mem,
448 struct mem_cgroup_per_zone *mz,
449 struct mem_cgroup_tree_per_zone *mctz)
451 spin_lock(&mctz->lock);
452 __mem_cgroup_remove_exceeded(mem, mz, mctz);
453 spin_unlock(&mctz->lock);
457 static void mem_cgroup_update_tree(struct mem_cgroup *mem, struct page *page)
459 unsigned long long excess;
460 struct mem_cgroup_per_zone *mz;
461 struct mem_cgroup_tree_per_zone *mctz;
462 int nid = page_to_nid(page);
463 int zid = page_zonenum(page);
464 mctz = soft_limit_tree_from_page(page);
467 * Necessary to update all ancestors when hierarchy is used.
468 * because their event counter is not touched.
470 for (; mem; mem = parent_mem_cgroup(mem)) {
471 mz = mem_cgroup_zoneinfo(mem, nid, zid);
472 excess = res_counter_soft_limit_excess(&mem->res);
474 * We have to update the tree if mz is on RB-tree or
475 * mem is over its softlimit.
477 if (excess || mz->on_tree) {
478 spin_lock(&mctz->lock);
479 /* if on-tree, remove it */
480 if (mz->on_tree)
481 __mem_cgroup_remove_exceeded(mem, mz, mctz);
483 * Insert again. mz->usage_in_excess will be updated.
484 * If excess is 0, no tree ops.
486 __mem_cgroup_insert_exceeded(mem, mz, mctz, excess);
487 spin_unlock(&mctz->lock);
492 static void mem_cgroup_remove_from_trees(struct mem_cgroup *mem)
494 int node, zone;
495 struct mem_cgroup_per_zone *mz;
496 struct mem_cgroup_tree_per_zone *mctz;
498 for_each_node_state(node, N_POSSIBLE) {
499 for (zone = 0; zone < MAX_NR_ZONES; zone++) {
500 mz = mem_cgroup_zoneinfo(mem, node, zone);
501 mctz = soft_limit_tree_node_zone(node, zone);
502 mem_cgroup_remove_exceeded(mem, mz, mctz);
507 static inline unsigned long mem_cgroup_get_excess(struct mem_cgroup *mem)
509 return res_counter_soft_limit_excess(&mem->res) >> PAGE_SHIFT;
512 static struct mem_cgroup_per_zone *
513 __mem_cgroup_largest_soft_limit_node(struct mem_cgroup_tree_per_zone *mctz)
515 struct rb_node *rightmost = NULL;
516 struct mem_cgroup_per_zone *mz;
518 retry:
519 mz = NULL;
520 rightmost = rb_last(&mctz->rb_root);
521 if (!rightmost)
522 goto done; /* Nothing to reclaim from */
524 mz = rb_entry(rightmost, struct mem_cgroup_per_zone, tree_node);
526 * Remove the node now but someone else can add it back,
527 * we will to add it back at the end of reclaim to its correct
528 * position in the tree.
530 __mem_cgroup_remove_exceeded(mz->mem, mz, mctz);
531 if (!res_counter_soft_limit_excess(&mz->mem->res) ||
532 !css_tryget(&mz->mem->css))
533 goto retry;
534 done:
535 return mz;
538 static struct mem_cgroup_per_zone *
539 mem_cgroup_largest_soft_limit_node(struct mem_cgroup_tree_per_zone *mctz)
541 struct mem_cgroup_per_zone *mz;
543 spin_lock(&mctz->lock);
544 mz = __mem_cgroup_largest_soft_limit_node(mctz);
545 spin_unlock(&mctz->lock);
546 return mz;
550 * Implementation Note: reading percpu statistics for memcg.
552 * Both of vmstat[] and percpu_counter has threshold and do periodic
553 * synchronization to implement "quick" read. There are trade-off between
554 * reading cost and precision of value. Then, we may have a chance to implement
555 * a periodic synchronizion of counter in memcg's counter.
557 * But this _read() function is used for user interface now. The user accounts
558 * memory usage by memory cgroup and he _always_ requires exact value because
559 * he accounts memory. Even if we provide quick-and-fuzzy read, we always
560 * have to visit all online cpus and make sum. So, for now, unnecessary
561 * synchronization is not implemented. (just implemented for cpu hotplug)
563 * If there are kernel internal actions which can make use of some not-exact
564 * value, and reading all cpu value can be performance bottleneck in some
565 * common workload, threashold and synchonization as vmstat[] should be
566 * implemented.
568 static s64 mem_cgroup_read_stat(struct mem_cgroup *mem,
569 enum mem_cgroup_stat_index idx)
571 int cpu;
572 s64 val = 0;
574 get_online_cpus();
575 for_each_online_cpu(cpu)
576 val += per_cpu(mem->stat->count[idx], cpu);
577 #ifdef CONFIG_HOTPLUG_CPU
578 spin_lock(&mem->pcp_counter_lock);
579 val += mem->nocpu_base.count[idx];
580 spin_unlock(&mem->pcp_counter_lock);
581 #endif
582 put_online_cpus();
583 return val;
586 static s64 mem_cgroup_local_usage(struct mem_cgroup *mem)
588 s64 ret;
590 ret = mem_cgroup_read_stat(mem, MEM_CGROUP_STAT_RSS);
591 ret += mem_cgroup_read_stat(mem, MEM_CGROUP_STAT_CACHE);
592 return ret;
595 static void mem_cgroup_swap_statistics(struct mem_cgroup *mem,
596 bool charge)
598 int val = (charge) ? 1 : -1;
599 this_cpu_add(mem->stat->count[MEM_CGROUP_STAT_SWAPOUT], val);
602 static void mem_cgroup_charge_statistics(struct mem_cgroup *mem,
603 bool file, int nr_pages)
605 preempt_disable();
607 if (file)
608 __this_cpu_add(mem->stat->count[MEM_CGROUP_STAT_CACHE], nr_pages);
609 else
610 __this_cpu_add(mem->stat->count[MEM_CGROUP_STAT_RSS], nr_pages);
612 /* pagein of a big page is an event. So, ignore page size */
613 if (nr_pages > 0)
614 __this_cpu_inc(mem->stat->count[MEM_CGROUP_STAT_PGPGIN_COUNT]);
615 else
616 __this_cpu_inc(mem->stat->count[MEM_CGROUP_STAT_PGPGOUT_COUNT]);
618 __this_cpu_add(mem->stat->count[MEM_CGROUP_EVENTS], nr_pages);
620 preempt_enable();
623 static unsigned long mem_cgroup_get_local_zonestat(struct mem_cgroup *mem,
624 enum lru_list idx)
626 int nid, zid;
627 struct mem_cgroup_per_zone *mz;
628 u64 total = 0;
630 for_each_online_node(nid)
631 for (zid = 0; zid < MAX_NR_ZONES; zid++) {
632 mz = mem_cgroup_zoneinfo(mem, nid, zid);
633 total += MEM_CGROUP_ZSTAT(mz, idx);
635 return total;
638 static bool __memcg_event_check(struct mem_cgroup *mem, int event_mask_shift)
640 s64 val;
642 val = this_cpu_read(mem->stat->count[MEM_CGROUP_EVENTS]);
644 return !(val & ((1 << event_mask_shift) - 1));
648 * Check events in order.
651 static void memcg_check_events(struct mem_cgroup *mem, struct page *page)
653 /* threshold event is triggered in finer grain than soft limit */
654 if (unlikely(__memcg_event_check(mem, THRESHOLDS_EVENTS_THRESH))) {
655 mem_cgroup_threshold(mem);
656 if (unlikely(__memcg_event_check(mem, SOFTLIMIT_EVENTS_THRESH)))
657 mem_cgroup_update_tree(mem, page);
661 static struct mem_cgroup *mem_cgroup_from_cont(struct cgroup *cont)
663 return container_of(cgroup_subsys_state(cont,
664 mem_cgroup_subsys_id), struct mem_cgroup,
665 css);
668 struct mem_cgroup *mem_cgroup_from_task(struct task_struct *p)
671 * mm_update_next_owner() may clear mm->owner to NULL
672 * if it races with swapoff, page migration, etc.
673 * So this can be called with p == NULL.
675 if (unlikely(!p))
676 return NULL;
678 return container_of(task_subsys_state(p, mem_cgroup_subsys_id),
679 struct mem_cgroup, css);
682 static struct mem_cgroup *try_get_mem_cgroup_from_mm(struct mm_struct *mm)
684 struct mem_cgroup *mem = NULL;
686 if (!mm)
687 return NULL;
689 * Because we have no locks, mm->owner's may be being moved to other
690 * cgroup. We use css_tryget() here even if this looks
691 * pessimistic (rather than adding locks here).
693 rcu_read_lock();
694 do {
695 mem = mem_cgroup_from_task(rcu_dereference(mm->owner));
696 if (unlikely(!mem))
697 break;
698 } while (!css_tryget(&mem->css));
699 rcu_read_unlock();
700 return mem;
703 /* The caller has to guarantee "mem" exists before calling this */
704 static struct mem_cgroup *mem_cgroup_start_loop(struct mem_cgroup *mem)
706 struct cgroup_subsys_state *css;
707 int found;
709 if (!mem) /* ROOT cgroup has the smallest ID */
710 return root_mem_cgroup; /*css_put/get against root is ignored*/
711 if (!mem->use_hierarchy) {
712 if (css_tryget(&mem->css))
713 return mem;
714 return NULL;
716 rcu_read_lock();
718 * searching a memory cgroup which has the smallest ID under given
719 * ROOT cgroup. (ID >= 1)
721 css = css_get_next(&mem_cgroup_subsys, 1, &mem->css, &found);
722 if (css && css_tryget(css))
723 mem = container_of(css, struct mem_cgroup, css);
724 else
725 mem = NULL;
726 rcu_read_unlock();
727 return mem;
730 static struct mem_cgroup *mem_cgroup_get_next(struct mem_cgroup *iter,
731 struct mem_cgroup *root,
732 bool cond)
734 int nextid = css_id(&iter->css) + 1;
735 int found;
736 int hierarchy_used;
737 struct cgroup_subsys_state *css;
739 hierarchy_used = iter->use_hierarchy;
741 css_put(&iter->css);
742 /* If no ROOT, walk all, ignore hierarchy */
743 if (!cond || (root && !hierarchy_used))
744 return NULL;
746 if (!root)
747 root = root_mem_cgroup;
749 do {
750 iter = NULL;
751 rcu_read_lock();
753 css = css_get_next(&mem_cgroup_subsys, nextid,
754 &root->css, &found);
755 if (css && css_tryget(css))
756 iter = container_of(css, struct mem_cgroup, css);
757 rcu_read_unlock();
758 /* If css is NULL, no more cgroups will be found */
759 nextid = found + 1;
760 } while (css && !iter);
762 return iter;
765 * for_eacn_mem_cgroup_tree() for visiting all cgroup under tree. Please
766 * be careful that "break" loop is not allowed. We have reference count.
767 * Instead of that modify "cond" to be false and "continue" to exit the loop.
769 #define for_each_mem_cgroup_tree_cond(iter, root, cond) \
770 for (iter = mem_cgroup_start_loop(root);\
771 iter != NULL;\
772 iter = mem_cgroup_get_next(iter, root, cond))
774 #define for_each_mem_cgroup_tree(iter, root) \
775 for_each_mem_cgroup_tree_cond(iter, root, true)
777 #define for_each_mem_cgroup_all(iter) \
778 for_each_mem_cgroup_tree_cond(iter, NULL, true)
781 static inline bool mem_cgroup_is_root(struct mem_cgroup *mem)
783 return (mem == root_mem_cgroup);
787 * Following LRU functions are allowed to be used without PCG_LOCK.
788 * Operations are called by routine of global LRU independently from memcg.
789 * What we have to take care of here is validness of pc->mem_cgroup.
791 * Changes to pc->mem_cgroup happens when
792 * 1. charge
793 * 2. moving account
794 * In typical case, "charge" is done before add-to-lru. Exception is SwapCache.
795 * It is added to LRU before charge.
796 * If PCG_USED bit is not set, page_cgroup is not added to this private LRU.
797 * When moving account, the page is not on LRU. It's isolated.
800 void mem_cgroup_del_lru_list(struct page *page, enum lru_list lru)
802 struct page_cgroup *pc;
803 struct mem_cgroup_per_zone *mz;
805 if (mem_cgroup_disabled())
806 return;
807 pc = lookup_page_cgroup(page);
808 /* can happen while we handle swapcache. */
809 if (!TestClearPageCgroupAcctLRU(pc))
810 return;
811 VM_BUG_ON(!pc->mem_cgroup);
813 * We don't check PCG_USED bit. It's cleared when the "page" is finally
814 * removed from global LRU.
816 mz = page_cgroup_zoneinfo(pc);
817 /* huge page split is done under lru_lock. so, we have no races. */
818 MEM_CGROUP_ZSTAT(mz, lru) -= 1 << compound_order(page);
819 if (mem_cgroup_is_root(pc->mem_cgroup))
820 return;
821 VM_BUG_ON(list_empty(&pc->lru));
822 list_del_init(&pc->lru);
825 void mem_cgroup_del_lru(struct page *page)
827 mem_cgroup_del_lru_list(page, page_lru(page));
830 void mem_cgroup_rotate_lru_list(struct page *page, enum lru_list lru)
832 struct mem_cgroup_per_zone *mz;
833 struct page_cgroup *pc;
835 if (mem_cgroup_disabled())
836 return;
838 pc = lookup_page_cgroup(page);
839 /* unused or root page is not rotated. */
840 if (!PageCgroupUsed(pc))
841 return;
842 /* Ensure pc->mem_cgroup is visible after reading PCG_USED. */
843 smp_rmb();
844 if (mem_cgroup_is_root(pc->mem_cgroup))
845 return;
846 mz = page_cgroup_zoneinfo(pc);
847 list_move(&pc->lru, &mz->lists[lru]);
850 void mem_cgroup_add_lru_list(struct page *page, enum lru_list lru)
852 struct page_cgroup *pc;
853 struct mem_cgroup_per_zone *mz;
855 if (mem_cgroup_disabled())
856 return;
857 pc = lookup_page_cgroup(page);
858 VM_BUG_ON(PageCgroupAcctLRU(pc));
859 if (!PageCgroupUsed(pc))
860 return;
861 /* Ensure pc->mem_cgroup is visible after reading PCG_USED. */
862 smp_rmb();
863 mz = page_cgroup_zoneinfo(pc);
864 /* huge page split is done under lru_lock. so, we have no races. */
865 MEM_CGROUP_ZSTAT(mz, lru) += 1 << compound_order(page);
866 SetPageCgroupAcctLRU(pc);
867 if (mem_cgroup_is_root(pc->mem_cgroup))
868 return;
869 list_add(&pc->lru, &mz->lists[lru]);
873 * At handling SwapCache, pc->mem_cgroup may be changed while it's linked to
874 * lru because the page may.be reused after it's fully uncharged (because of
875 * SwapCache behavior).To handle that, unlink page_cgroup from LRU when charge
876 * it again. This function is only used to charge SwapCache. It's done under
877 * lock_page and expected that zone->lru_lock is never held.
879 static void mem_cgroup_lru_del_before_commit_swapcache(struct page *page)
881 unsigned long flags;
882 struct zone *zone = page_zone(page);
883 struct page_cgroup *pc = lookup_page_cgroup(page);
885 spin_lock_irqsave(&zone->lru_lock, flags);
887 * Forget old LRU when this page_cgroup is *not* used. This Used bit
888 * is guarded by lock_page() because the page is SwapCache.
890 if (!PageCgroupUsed(pc))
891 mem_cgroup_del_lru_list(page, page_lru(page));
892 spin_unlock_irqrestore(&zone->lru_lock, flags);
895 static void mem_cgroup_lru_add_after_commit_swapcache(struct page *page)
897 unsigned long flags;
898 struct zone *zone = page_zone(page);
899 struct page_cgroup *pc = lookup_page_cgroup(page);
901 spin_lock_irqsave(&zone->lru_lock, flags);
902 /* link when the page is linked to LRU but page_cgroup isn't */
903 if (PageLRU(page) && !PageCgroupAcctLRU(pc))
904 mem_cgroup_add_lru_list(page, page_lru(page));
905 spin_unlock_irqrestore(&zone->lru_lock, flags);
909 void mem_cgroup_move_lists(struct page *page,
910 enum lru_list from, enum lru_list to)
912 if (mem_cgroup_disabled())
913 return;
914 mem_cgroup_del_lru_list(page, from);
915 mem_cgroup_add_lru_list(page, to);
918 int task_in_mem_cgroup(struct task_struct *task, const struct mem_cgroup *mem)
920 int ret;
921 struct mem_cgroup *curr = NULL;
922 struct task_struct *p;
924 p = find_lock_task_mm(task);
925 if (!p)
926 return 0;
927 curr = try_get_mem_cgroup_from_mm(p->mm);
928 task_unlock(p);
929 if (!curr)
930 return 0;
932 * We should check use_hierarchy of "mem" not "curr". Because checking
933 * use_hierarchy of "curr" here make this function true if hierarchy is
934 * enabled in "curr" and "curr" is a child of "mem" in *cgroup*
935 * hierarchy(even if use_hierarchy is disabled in "mem").
937 if (mem->use_hierarchy)
938 ret = css_is_ancestor(&curr->css, &mem->css);
939 else
940 ret = (curr == mem);
941 css_put(&curr->css);
942 return ret;
945 static int calc_inactive_ratio(struct mem_cgroup *memcg, unsigned long *present_pages)
947 unsigned long active;
948 unsigned long inactive;
949 unsigned long gb;
950 unsigned long inactive_ratio;
952 inactive = mem_cgroup_get_local_zonestat(memcg, LRU_INACTIVE_ANON);
953 active = mem_cgroup_get_local_zonestat(memcg, LRU_ACTIVE_ANON);
955 gb = (inactive + active) >> (30 - PAGE_SHIFT);
956 if (gb)
957 inactive_ratio = int_sqrt(10 * gb);
958 else
959 inactive_ratio = 1;
961 if (present_pages) {
962 present_pages[0] = inactive;
963 present_pages[1] = active;
966 return inactive_ratio;
969 int mem_cgroup_inactive_anon_is_low(struct mem_cgroup *memcg)
971 unsigned long active;
972 unsigned long inactive;
973 unsigned long present_pages[2];
974 unsigned long inactive_ratio;
976 inactive_ratio = calc_inactive_ratio(memcg, present_pages);
978 inactive = present_pages[0];
979 active = present_pages[1];
981 if (inactive * inactive_ratio < active)
982 return 1;
984 return 0;
987 int mem_cgroup_inactive_file_is_low(struct mem_cgroup *memcg)
989 unsigned long active;
990 unsigned long inactive;
992 inactive = mem_cgroup_get_local_zonestat(memcg, LRU_INACTIVE_FILE);
993 active = mem_cgroup_get_local_zonestat(memcg, LRU_ACTIVE_FILE);
995 return (active > inactive);
998 unsigned long mem_cgroup_zone_nr_pages(struct mem_cgroup *memcg,
999 struct zone *zone,
1000 enum lru_list lru)
1002 int nid = zone_to_nid(zone);
1003 int zid = zone_idx(zone);
1004 struct mem_cgroup_per_zone *mz = mem_cgroup_zoneinfo(memcg, nid, zid);
1006 return MEM_CGROUP_ZSTAT(mz, lru);
1009 struct zone_reclaim_stat *mem_cgroup_get_reclaim_stat(struct mem_cgroup *memcg,
1010 struct zone *zone)
1012 int nid = zone_to_nid(zone);
1013 int zid = zone_idx(zone);
1014 struct mem_cgroup_per_zone *mz = mem_cgroup_zoneinfo(memcg, nid, zid);
1016 return &mz->reclaim_stat;
1019 struct zone_reclaim_stat *
1020 mem_cgroup_get_reclaim_stat_from_page(struct page *page)
1022 struct page_cgroup *pc;
1023 struct mem_cgroup_per_zone *mz;
1025 if (mem_cgroup_disabled())
1026 return NULL;
1028 pc = lookup_page_cgroup(page);
1029 if (!PageCgroupUsed(pc))
1030 return NULL;
1031 /* Ensure pc->mem_cgroup is visible after reading PCG_USED. */
1032 smp_rmb();
1033 mz = page_cgroup_zoneinfo(pc);
1034 if (!mz)
1035 return NULL;
1037 return &mz->reclaim_stat;
1040 unsigned long mem_cgroup_isolate_pages(unsigned long nr_to_scan,
1041 struct list_head *dst,
1042 unsigned long *scanned, int order,
1043 int mode, struct zone *z,
1044 struct mem_cgroup *mem_cont,
1045 int active, int file)
1047 unsigned long nr_taken = 0;
1048 struct page *page;
1049 unsigned long scan;
1050 LIST_HEAD(pc_list);
1051 struct list_head *src;
1052 struct page_cgroup *pc, *tmp;
1053 int nid = zone_to_nid(z);
1054 int zid = zone_idx(z);
1055 struct mem_cgroup_per_zone *mz;
1056 int lru = LRU_FILE * file + active;
1057 int ret;
1059 BUG_ON(!mem_cont);
1060 mz = mem_cgroup_zoneinfo(mem_cont, nid, zid);
1061 src = &mz->lists[lru];
1063 scan = 0;
1064 list_for_each_entry_safe_reverse(pc, tmp, src, lru) {
1065 if (scan >= nr_to_scan)
1066 break;
1068 page = pc->page;
1069 if (unlikely(!PageCgroupUsed(pc)))
1070 continue;
1071 if (unlikely(!PageLRU(page)))
1072 continue;
1074 scan++;
1075 ret = __isolate_lru_page(page, mode, file);
1076 switch (ret) {
1077 case 0:
1078 list_move(&page->lru, dst);
1079 mem_cgroup_del_lru(page);
1080 nr_taken += hpage_nr_pages(page);
1081 break;
1082 case -EBUSY:
1083 /* we don't affect global LRU but rotate in our LRU */
1084 mem_cgroup_rotate_lru_list(page, page_lru(page));
1085 break;
1086 default:
1087 break;
1091 *scanned = scan;
1093 trace_mm_vmscan_memcg_isolate(0, nr_to_scan, scan, nr_taken,
1094 0, 0, 0, mode);
1096 return nr_taken;
1099 #define mem_cgroup_from_res_counter(counter, member) \
1100 container_of(counter, struct mem_cgroup, member)
1102 static bool mem_cgroup_check_under_limit(struct mem_cgroup *mem)
1104 if (do_swap_account) {
1105 if (res_counter_check_under_limit(&mem->res) &&
1106 res_counter_check_under_limit(&mem->memsw))
1107 return true;
1108 } else
1109 if (res_counter_check_under_limit(&mem->res))
1110 return true;
1111 return false;
1114 static unsigned int get_swappiness(struct mem_cgroup *memcg)
1116 struct cgroup *cgrp = memcg->css.cgroup;
1117 unsigned int swappiness;
1119 /* root ? */
1120 if (cgrp->parent == NULL)
1121 return vm_swappiness;
1123 spin_lock(&memcg->reclaim_param_lock);
1124 swappiness = memcg->swappiness;
1125 spin_unlock(&memcg->reclaim_param_lock);
1127 return swappiness;
1130 static void mem_cgroup_start_move(struct mem_cgroup *mem)
1132 int cpu;
1134 get_online_cpus();
1135 spin_lock(&mem->pcp_counter_lock);
1136 for_each_online_cpu(cpu)
1137 per_cpu(mem->stat->count[MEM_CGROUP_ON_MOVE], cpu) += 1;
1138 mem->nocpu_base.count[MEM_CGROUP_ON_MOVE] += 1;
1139 spin_unlock(&mem->pcp_counter_lock);
1140 put_online_cpus();
1142 synchronize_rcu();
1145 static void mem_cgroup_end_move(struct mem_cgroup *mem)
1147 int cpu;
1149 if (!mem)
1150 return;
1151 get_online_cpus();
1152 spin_lock(&mem->pcp_counter_lock);
1153 for_each_online_cpu(cpu)
1154 per_cpu(mem->stat->count[MEM_CGROUP_ON_MOVE], cpu) -= 1;
1155 mem->nocpu_base.count[MEM_CGROUP_ON_MOVE] -= 1;
1156 spin_unlock(&mem->pcp_counter_lock);
1157 put_online_cpus();
1160 * 2 routines for checking "mem" is under move_account() or not.
1162 * mem_cgroup_stealed() - checking a cgroup is mc.from or not. This is used
1163 * for avoiding race in accounting. If true,
1164 * pc->mem_cgroup may be overwritten.
1166 * mem_cgroup_under_move() - checking a cgroup is mc.from or mc.to or
1167 * under hierarchy of moving cgroups. This is for
1168 * waiting at hith-memory prressure caused by "move".
1171 static bool mem_cgroup_stealed(struct mem_cgroup *mem)
1173 VM_BUG_ON(!rcu_read_lock_held());
1174 return this_cpu_read(mem->stat->count[MEM_CGROUP_ON_MOVE]) > 0;
1177 static bool mem_cgroup_under_move(struct mem_cgroup *mem)
1179 struct mem_cgroup *from;
1180 struct mem_cgroup *to;
1181 bool ret = false;
1183 * Unlike task_move routines, we access mc.to, mc.from not under
1184 * mutual exclusion by cgroup_mutex. Here, we take spinlock instead.
1186 spin_lock(&mc.lock);
1187 from = mc.from;
1188 to = mc.to;
1189 if (!from)
1190 goto unlock;
1191 if (from == mem || to == mem
1192 || (mem->use_hierarchy && css_is_ancestor(&from->css, &mem->css))
1193 || (mem->use_hierarchy && css_is_ancestor(&to->css, &mem->css)))
1194 ret = true;
1195 unlock:
1196 spin_unlock(&mc.lock);
1197 return ret;
1200 static bool mem_cgroup_wait_acct_move(struct mem_cgroup *mem)
1202 if (mc.moving_task && current != mc.moving_task) {
1203 if (mem_cgroup_under_move(mem)) {
1204 DEFINE_WAIT(wait);
1205 prepare_to_wait(&mc.waitq, &wait, TASK_INTERRUPTIBLE);
1206 /* moving charge context might have finished. */
1207 if (mc.moving_task)
1208 schedule();
1209 finish_wait(&mc.waitq, &wait);
1210 return true;
1213 return false;
1217 * mem_cgroup_print_oom_info: Called from OOM with tasklist_lock held in read mode.
1218 * @memcg: The memory cgroup that went over limit
1219 * @p: Task that is going to be killed
1221 * NOTE: @memcg and @p's mem_cgroup can be different when hierarchy is
1222 * enabled
1224 void mem_cgroup_print_oom_info(struct mem_cgroup *memcg, struct task_struct *p)
1226 struct cgroup *task_cgrp;
1227 struct cgroup *mem_cgrp;
1229 * Need a buffer in BSS, can't rely on allocations. The code relies
1230 * on the assumption that OOM is serialized for memory controller.
1231 * If this assumption is broken, revisit this code.
1233 static char memcg_name[PATH_MAX];
1234 int ret;
1236 if (!memcg || !p)
1237 return;
1240 rcu_read_lock();
1242 mem_cgrp = memcg->css.cgroup;
1243 task_cgrp = task_cgroup(p, mem_cgroup_subsys_id);
1245 ret = cgroup_path(task_cgrp, memcg_name, PATH_MAX);
1246 if (ret < 0) {
1248 * Unfortunately, we are unable to convert to a useful name
1249 * But we'll still print out the usage information
1251 rcu_read_unlock();
1252 goto done;
1254 rcu_read_unlock();
1256 printk(KERN_INFO "Task in %s killed", memcg_name);
1258 rcu_read_lock();
1259 ret = cgroup_path(mem_cgrp, memcg_name, PATH_MAX);
1260 if (ret < 0) {
1261 rcu_read_unlock();
1262 goto done;
1264 rcu_read_unlock();
1267 * Continues from above, so we don't need an KERN_ level
1269 printk(KERN_CONT " as a result of limit of %s\n", memcg_name);
1270 done:
1272 printk(KERN_INFO "memory: usage %llukB, limit %llukB, failcnt %llu\n",
1273 res_counter_read_u64(&memcg->res, RES_USAGE) >> 10,
1274 res_counter_read_u64(&memcg->res, RES_LIMIT) >> 10,
1275 res_counter_read_u64(&memcg->res, RES_FAILCNT));
1276 printk(KERN_INFO "memory+swap: usage %llukB, limit %llukB, "
1277 "failcnt %llu\n",
1278 res_counter_read_u64(&memcg->memsw, RES_USAGE) >> 10,
1279 res_counter_read_u64(&memcg->memsw, RES_LIMIT) >> 10,
1280 res_counter_read_u64(&memcg->memsw, RES_FAILCNT));
1284 * This function returns the number of memcg under hierarchy tree. Returns
1285 * 1(self count) if no children.
1287 static int mem_cgroup_count_children(struct mem_cgroup *mem)
1289 int num = 0;
1290 struct mem_cgroup *iter;
1292 for_each_mem_cgroup_tree(iter, mem)
1293 num++;
1294 return num;
1298 * Return the memory (and swap, if configured) limit for a memcg.
1300 u64 mem_cgroup_get_limit(struct mem_cgroup *memcg)
1302 u64 limit;
1303 u64 memsw;
1305 limit = res_counter_read_u64(&memcg->res, RES_LIMIT);
1306 limit += total_swap_pages << PAGE_SHIFT;
1308 memsw = res_counter_read_u64(&memcg->memsw, RES_LIMIT);
1310 * If memsw is finite and limits the amount of swap space available
1311 * to this memcg, return that limit.
1313 return min(limit, memsw);
1317 * Visit the first child (need not be the first child as per the ordering
1318 * of the cgroup list, since we track last_scanned_child) of @mem and use
1319 * that to reclaim free pages from.
1321 static struct mem_cgroup *
1322 mem_cgroup_select_victim(struct mem_cgroup *root_mem)
1324 struct mem_cgroup *ret = NULL;
1325 struct cgroup_subsys_state *css;
1326 int nextid, found;
1328 if (!root_mem->use_hierarchy) {
1329 css_get(&root_mem->css);
1330 ret = root_mem;
1333 while (!ret) {
1334 rcu_read_lock();
1335 nextid = root_mem->last_scanned_child + 1;
1336 css = css_get_next(&mem_cgroup_subsys, nextid, &root_mem->css,
1337 &found);
1338 if (css && css_tryget(css))
1339 ret = container_of(css, struct mem_cgroup, css);
1341 rcu_read_unlock();
1342 /* Updates scanning parameter */
1343 spin_lock(&root_mem->reclaim_param_lock);
1344 if (!css) {
1345 /* this means start scan from ID:1 */
1346 root_mem->last_scanned_child = 0;
1347 } else
1348 root_mem->last_scanned_child = found;
1349 spin_unlock(&root_mem->reclaim_param_lock);
1352 return ret;
1356 * Scan the hierarchy if needed to reclaim memory. We remember the last child
1357 * we reclaimed from, so that we don't end up penalizing one child extensively
1358 * based on its position in the children list.
1360 * root_mem is the original ancestor that we've been reclaim from.
1362 * We give up and return to the caller when we visit root_mem twice.
1363 * (other groups can be removed while we're walking....)
1365 * If shrink==true, for avoiding to free too much, this returns immedieately.
1367 static int mem_cgroup_hierarchical_reclaim(struct mem_cgroup *root_mem,
1368 struct zone *zone,
1369 gfp_t gfp_mask,
1370 unsigned long reclaim_options)
1372 struct mem_cgroup *victim;
1373 int ret, total = 0;
1374 int loop = 0;
1375 bool noswap = reclaim_options & MEM_CGROUP_RECLAIM_NOSWAP;
1376 bool shrink = reclaim_options & MEM_CGROUP_RECLAIM_SHRINK;
1377 bool check_soft = reclaim_options & MEM_CGROUP_RECLAIM_SOFT;
1378 unsigned long excess = mem_cgroup_get_excess(root_mem);
1380 /* If memsw_is_minimum==1, swap-out is of-no-use. */
1381 if (root_mem->memsw_is_minimum)
1382 noswap = true;
1384 while (1) {
1385 victim = mem_cgroup_select_victim(root_mem);
1386 if (victim == root_mem) {
1387 loop++;
1388 if (loop >= 1)
1389 drain_all_stock_async();
1390 if (loop >= 2) {
1392 * If we have not been able to reclaim
1393 * anything, it might because there are
1394 * no reclaimable pages under this hierarchy
1396 if (!check_soft || !total) {
1397 css_put(&victim->css);
1398 break;
1401 * We want to do more targetted reclaim.
1402 * excess >> 2 is not to excessive so as to
1403 * reclaim too much, nor too less that we keep
1404 * coming back to reclaim from this cgroup
1406 if (total >= (excess >> 2) ||
1407 (loop > MEM_CGROUP_MAX_RECLAIM_LOOPS)) {
1408 css_put(&victim->css);
1409 break;
1413 if (!mem_cgroup_local_usage(victim)) {
1414 /* this cgroup's local usage == 0 */
1415 css_put(&victim->css);
1416 continue;
1418 /* we use swappiness of local cgroup */
1419 if (check_soft)
1420 ret = mem_cgroup_shrink_node_zone(victim, gfp_mask,
1421 noswap, get_swappiness(victim), zone);
1422 else
1423 ret = try_to_free_mem_cgroup_pages(victim, gfp_mask,
1424 noswap, get_swappiness(victim));
1425 css_put(&victim->css);
1427 * At shrinking usage, we can't check we should stop here or
1428 * reclaim more. It's depends on callers. last_scanned_child
1429 * will work enough for keeping fairness under tree.
1431 if (shrink)
1432 return ret;
1433 total += ret;
1434 if (check_soft) {
1435 if (res_counter_check_under_soft_limit(&root_mem->res))
1436 return total;
1437 } else if (mem_cgroup_check_under_limit(root_mem))
1438 return 1 + total;
1440 return total;
1444 * Check OOM-Killer is already running under our hierarchy.
1445 * If someone is running, return false.
1447 static bool mem_cgroup_oom_lock(struct mem_cgroup *mem)
1449 int x, lock_count = 0;
1450 struct mem_cgroup *iter;
1452 for_each_mem_cgroup_tree(iter, mem) {
1453 x = atomic_inc_return(&iter->oom_lock);
1454 lock_count = max(x, lock_count);
1457 if (lock_count == 1)
1458 return true;
1459 return false;
1462 static int mem_cgroup_oom_unlock(struct mem_cgroup *mem)
1464 struct mem_cgroup *iter;
1467 * When a new child is created while the hierarchy is under oom,
1468 * mem_cgroup_oom_lock() may not be called. We have to use
1469 * atomic_add_unless() here.
1471 for_each_mem_cgroup_tree(iter, mem)
1472 atomic_add_unless(&iter->oom_lock, -1, 0);
1473 return 0;
1477 static DEFINE_MUTEX(memcg_oom_mutex);
1478 static DECLARE_WAIT_QUEUE_HEAD(memcg_oom_waitq);
1480 struct oom_wait_info {
1481 struct mem_cgroup *mem;
1482 wait_queue_t wait;
1485 static int memcg_oom_wake_function(wait_queue_t *wait,
1486 unsigned mode, int sync, void *arg)
1488 struct mem_cgroup *wake_mem = (struct mem_cgroup *)arg;
1489 struct oom_wait_info *oom_wait_info;
1491 oom_wait_info = container_of(wait, struct oom_wait_info, wait);
1493 if (oom_wait_info->mem == wake_mem)
1494 goto wakeup;
1495 /* if no hierarchy, no match */
1496 if (!oom_wait_info->mem->use_hierarchy || !wake_mem->use_hierarchy)
1497 return 0;
1499 * Both of oom_wait_info->mem and wake_mem are stable under us.
1500 * Then we can use css_is_ancestor without taking care of RCU.
1502 if (!css_is_ancestor(&oom_wait_info->mem->css, &wake_mem->css) &&
1503 !css_is_ancestor(&wake_mem->css, &oom_wait_info->mem->css))
1504 return 0;
1506 wakeup:
1507 return autoremove_wake_function(wait, mode, sync, arg);
1510 static void memcg_wakeup_oom(struct mem_cgroup *mem)
1512 /* for filtering, pass "mem" as argument. */
1513 __wake_up(&memcg_oom_waitq, TASK_NORMAL, 0, mem);
1516 static void memcg_oom_recover(struct mem_cgroup *mem)
1518 if (mem && atomic_read(&mem->oom_lock))
1519 memcg_wakeup_oom(mem);
1523 * try to call OOM killer. returns false if we should exit memory-reclaim loop.
1525 bool mem_cgroup_handle_oom(struct mem_cgroup *mem, gfp_t mask)
1527 struct oom_wait_info owait;
1528 bool locked, need_to_kill;
1530 owait.mem = mem;
1531 owait.wait.flags = 0;
1532 owait.wait.func = memcg_oom_wake_function;
1533 owait.wait.private = current;
1534 INIT_LIST_HEAD(&owait.wait.task_list);
1535 need_to_kill = true;
1536 /* At first, try to OOM lock hierarchy under mem.*/
1537 mutex_lock(&memcg_oom_mutex);
1538 locked = mem_cgroup_oom_lock(mem);
1540 * Even if signal_pending(), we can't quit charge() loop without
1541 * accounting. So, UNINTERRUPTIBLE is appropriate. But SIGKILL
1542 * under OOM is always welcomed, use TASK_KILLABLE here.
1544 prepare_to_wait(&memcg_oom_waitq, &owait.wait, TASK_KILLABLE);
1545 if (!locked || mem->oom_kill_disable)
1546 need_to_kill = false;
1547 if (locked)
1548 mem_cgroup_oom_notify(mem);
1549 mutex_unlock(&memcg_oom_mutex);
1551 if (need_to_kill) {
1552 finish_wait(&memcg_oom_waitq, &owait.wait);
1553 mem_cgroup_out_of_memory(mem, mask);
1554 } else {
1555 schedule();
1556 finish_wait(&memcg_oom_waitq, &owait.wait);
1558 mutex_lock(&memcg_oom_mutex);
1559 mem_cgroup_oom_unlock(mem);
1560 memcg_wakeup_oom(mem);
1561 mutex_unlock(&memcg_oom_mutex);
1563 if (test_thread_flag(TIF_MEMDIE) || fatal_signal_pending(current))
1564 return false;
1565 /* Give chance to dying process */
1566 schedule_timeout(1);
1567 return true;
1571 * Currently used to update mapped file statistics, but the routine can be
1572 * generalized to update other statistics as well.
1574 * Notes: Race condition
1576 * We usually use page_cgroup_lock() for accessing page_cgroup member but
1577 * it tends to be costly. But considering some conditions, we doesn't need
1578 * to do so _always_.
1580 * Considering "charge", lock_page_cgroup() is not required because all
1581 * file-stat operations happen after a page is attached to radix-tree. There
1582 * are no race with "charge".
1584 * Considering "uncharge", we know that memcg doesn't clear pc->mem_cgroup
1585 * at "uncharge" intentionally. So, we always see valid pc->mem_cgroup even
1586 * if there are race with "uncharge". Statistics itself is properly handled
1587 * by flags.
1589 * Considering "move", this is an only case we see a race. To make the race
1590 * small, we check MEM_CGROUP_ON_MOVE percpu value and detect there are
1591 * possibility of race condition. If there is, we take a lock.
1594 void mem_cgroup_update_page_stat(struct page *page,
1595 enum mem_cgroup_page_stat_item idx, int val)
1597 struct mem_cgroup *mem;
1598 struct page_cgroup *pc = lookup_page_cgroup(page);
1599 bool need_unlock = false;
1600 unsigned long uninitialized_var(flags);
1602 if (unlikely(!pc))
1603 return;
1605 rcu_read_lock();
1606 mem = pc->mem_cgroup;
1607 if (unlikely(!mem || !PageCgroupUsed(pc)))
1608 goto out;
1609 /* pc->mem_cgroup is unstable ? */
1610 if (unlikely(mem_cgroup_stealed(mem)) || PageTransHuge(page)) {
1611 /* take a lock against to access pc->mem_cgroup */
1612 move_lock_page_cgroup(pc, &flags);
1613 need_unlock = true;
1614 mem = pc->mem_cgroup;
1615 if (!mem || !PageCgroupUsed(pc))
1616 goto out;
1619 switch (idx) {
1620 case MEMCG_NR_FILE_MAPPED:
1621 if (val > 0)
1622 SetPageCgroupFileMapped(pc);
1623 else if (!page_mapped(page))
1624 ClearPageCgroupFileMapped(pc);
1625 idx = MEM_CGROUP_STAT_FILE_MAPPED;
1626 break;
1627 default:
1628 BUG();
1631 this_cpu_add(mem->stat->count[idx], val);
1633 out:
1634 if (unlikely(need_unlock))
1635 move_unlock_page_cgroup(pc, &flags);
1636 rcu_read_unlock();
1637 return;
1639 EXPORT_SYMBOL(mem_cgroup_update_page_stat);
1642 * size of first charge trial. "32" comes from vmscan.c's magic value.
1643 * TODO: maybe necessary to use big numbers in big irons.
1645 #define CHARGE_SIZE (32 * PAGE_SIZE)
1646 struct memcg_stock_pcp {
1647 struct mem_cgroup *cached; /* this never be root cgroup */
1648 int charge;
1649 struct work_struct work;
1651 static DEFINE_PER_CPU(struct memcg_stock_pcp, memcg_stock);
1652 static atomic_t memcg_drain_count;
1655 * Try to consume stocked charge on this cpu. If success, PAGE_SIZE is consumed
1656 * from local stock and true is returned. If the stock is 0 or charges from a
1657 * cgroup which is not current target, returns false. This stock will be
1658 * refilled.
1660 static bool consume_stock(struct mem_cgroup *mem)
1662 struct memcg_stock_pcp *stock;
1663 bool ret = true;
1665 stock = &get_cpu_var(memcg_stock);
1666 if (mem == stock->cached && stock->charge)
1667 stock->charge -= PAGE_SIZE;
1668 else /* need to call res_counter_charge */
1669 ret = false;
1670 put_cpu_var(memcg_stock);
1671 return ret;
1675 * Returns stocks cached in percpu to res_counter and reset cached information.
1677 static void drain_stock(struct memcg_stock_pcp *stock)
1679 struct mem_cgroup *old = stock->cached;
1681 if (stock->charge) {
1682 res_counter_uncharge(&old->res, stock->charge);
1683 if (do_swap_account)
1684 res_counter_uncharge(&old->memsw, stock->charge);
1686 stock->cached = NULL;
1687 stock->charge = 0;
1691 * This must be called under preempt disabled or must be called by
1692 * a thread which is pinned to local cpu.
1694 static void drain_local_stock(struct work_struct *dummy)
1696 struct memcg_stock_pcp *stock = &__get_cpu_var(memcg_stock);
1697 drain_stock(stock);
1701 * Cache charges(val) which is from res_counter, to local per_cpu area.
1702 * This will be consumed by consume_stock() function, later.
1704 static void refill_stock(struct mem_cgroup *mem, int val)
1706 struct memcg_stock_pcp *stock = &get_cpu_var(memcg_stock);
1708 if (stock->cached != mem) { /* reset if necessary */
1709 drain_stock(stock);
1710 stock->cached = mem;
1712 stock->charge += val;
1713 put_cpu_var(memcg_stock);
1717 * Tries to drain stocked charges in other cpus. This function is asynchronous
1718 * and just put a work per cpu for draining localy on each cpu. Caller can
1719 * expects some charges will be back to res_counter later but cannot wait for
1720 * it.
1722 static void drain_all_stock_async(void)
1724 int cpu;
1725 /* This function is for scheduling "drain" in asynchronous way.
1726 * The result of "drain" is not directly handled by callers. Then,
1727 * if someone is calling drain, we don't have to call drain more.
1728 * Anyway, WORK_STRUCT_PENDING check in queue_work_on() will catch if
1729 * there is a race. We just do loose check here.
1731 if (atomic_read(&memcg_drain_count))
1732 return;
1733 /* Notify other cpus that system-wide "drain" is running */
1734 atomic_inc(&memcg_drain_count);
1735 get_online_cpus();
1736 for_each_online_cpu(cpu) {
1737 struct memcg_stock_pcp *stock = &per_cpu(memcg_stock, cpu);
1738 schedule_work_on(cpu, &stock->work);
1740 put_online_cpus();
1741 atomic_dec(&memcg_drain_count);
1742 /* We don't wait for flush_work */
1745 /* This is a synchronous drain interface. */
1746 static void drain_all_stock_sync(void)
1748 /* called when force_empty is called */
1749 atomic_inc(&memcg_drain_count);
1750 schedule_on_each_cpu(drain_local_stock);
1751 atomic_dec(&memcg_drain_count);
1755 * This function drains percpu counter value from DEAD cpu and
1756 * move it to local cpu. Note that this function can be preempted.
1758 static void mem_cgroup_drain_pcp_counter(struct mem_cgroup *mem, int cpu)
1760 int i;
1762 spin_lock(&mem->pcp_counter_lock);
1763 for (i = 0; i < MEM_CGROUP_STAT_DATA; i++) {
1764 s64 x = per_cpu(mem->stat->count[i], cpu);
1766 per_cpu(mem->stat->count[i], cpu) = 0;
1767 mem->nocpu_base.count[i] += x;
1769 /* need to clear ON_MOVE value, works as a kind of lock. */
1770 per_cpu(mem->stat->count[MEM_CGROUP_ON_MOVE], cpu) = 0;
1771 spin_unlock(&mem->pcp_counter_lock);
1774 static void synchronize_mem_cgroup_on_move(struct mem_cgroup *mem, int cpu)
1776 int idx = MEM_CGROUP_ON_MOVE;
1778 spin_lock(&mem->pcp_counter_lock);
1779 per_cpu(mem->stat->count[idx], cpu) = mem->nocpu_base.count[idx];
1780 spin_unlock(&mem->pcp_counter_lock);
1783 static int __cpuinit memcg_cpu_hotplug_callback(struct notifier_block *nb,
1784 unsigned long action,
1785 void *hcpu)
1787 int cpu = (unsigned long)hcpu;
1788 struct memcg_stock_pcp *stock;
1789 struct mem_cgroup *iter;
1791 if ((action == CPU_ONLINE)) {
1792 for_each_mem_cgroup_all(iter)
1793 synchronize_mem_cgroup_on_move(iter, cpu);
1794 return NOTIFY_OK;
1797 if ((action != CPU_DEAD) || action != CPU_DEAD_FROZEN)
1798 return NOTIFY_OK;
1800 for_each_mem_cgroup_all(iter)
1801 mem_cgroup_drain_pcp_counter(iter, cpu);
1803 stock = &per_cpu(memcg_stock, cpu);
1804 drain_stock(stock);
1805 return NOTIFY_OK;
1809 /* See __mem_cgroup_try_charge() for details */
1810 enum {
1811 CHARGE_OK, /* success */
1812 CHARGE_RETRY, /* need to retry but retry is not bad */
1813 CHARGE_NOMEM, /* we can't do more. return -ENOMEM */
1814 CHARGE_WOULDBLOCK, /* GFP_WAIT wasn't set and no enough res. */
1815 CHARGE_OOM_DIE, /* the current is killed because of OOM */
1818 static int __mem_cgroup_do_charge(struct mem_cgroup *mem, gfp_t gfp_mask,
1819 int csize, bool oom_check)
1821 struct mem_cgroup *mem_over_limit;
1822 struct res_counter *fail_res;
1823 unsigned long flags = 0;
1824 int ret;
1826 ret = res_counter_charge(&mem->res, csize, &fail_res);
1828 if (likely(!ret)) {
1829 if (!do_swap_account)
1830 return CHARGE_OK;
1831 ret = res_counter_charge(&mem->memsw, csize, &fail_res);
1832 if (likely(!ret))
1833 return CHARGE_OK;
1835 res_counter_uncharge(&mem->res, csize);
1836 mem_over_limit = mem_cgroup_from_res_counter(fail_res, memsw);
1837 flags |= MEM_CGROUP_RECLAIM_NOSWAP;
1838 } else
1839 mem_over_limit = mem_cgroup_from_res_counter(fail_res, res);
1841 if (csize > PAGE_SIZE) /* change csize and retry */
1842 return CHARGE_RETRY;
1844 if (!(gfp_mask & __GFP_WAIT))
1845 return CHARGE_WOULDBLOCK;
1847 ret = mem_cgroup_hierarchical_reclaim(mem_over_limit, NULL,
1848 gfp_mask, flags);
1850 * try_to_free_mem_cgroup_pages() might not give us a full
1851 * picture of reclaim. Some pages are reclaimed and might be
1852 * moved to swap cache or just unmapped from the cgroup.
1853 * Check the limit again to see if the reclaim reduced the
1854 * current usage of the cgroup before giving up
1856 if (ret || mem_cgroup_check_under_limit(mem_over_limit))
1857 return CHARGE_RETRY;
1860 * At task move, charge accounts can be doubly counted. So, it's
1861 * better to wait until the end of task_move if something is going on.
1863 if (mem_cgroup_wait_acct_move(mem_over_limit))
1864 return CHARGE_RETRY;
1866 /* If we don't need to call oom-killer at el, return immediately */
1867 if (!oom_check)
1868 return CHARGE_NOMEM;
1869 /* check OOM */
1870 if (!mem_cgroup_handle_oom(mem_over_limit, gfp_mask))
1871 return CHARGE_OOM_DIE;
1873 return CHARGE_RETRY;
1877 * Unlike exported interface, "oom" parameter is added. if oom==true,
1878 * oom-killer can be invoked.
1880 static int __mem_cgroup_try_charge(struct mm_struct *mm,
1881 gfp_t gfp_mask,
1882 struct mem_cgroup **memcg, bool oom,
1883 int page_size)
1885 int nr_oom_retries = MEM_CGROUP_RECLAIM_RETRIES;
1886 struct mem_cgroup *mem = NULL;
1887 int ret;
1888 int csize = max(CHARGE_SIZE, (unsigned long) page_size);
1891 * Unlike gloval-vm's OOM-kill, we're not in memory shortage
1892 * in system level. So, allow to go ahead dying process in addition to
1893 * MEMDIE process.
1895 if (unlikely(test_thread_flag(TIF_MEMDIE)
1896 || fatal_signal_pending(current)))
1897 goto bypass;
1900 * We always charge the cgroup the mm_struct belongs to.
1901 * The mm_struct's mem_cgroup changes on task migration if the
1902 * thread group leader migrates. It's possible that mm is not
1903 * set, if so charge the init_mm (happens for pagecache usage).
1905 if (!*memcg && !mm)
1906 goto bypass;
1907 again:
1908 if (*memcg) { /* css should be a valid one */
1909 mem = *memcg;
1910 VM_BUG_ON(css_is_removed(&mem->css));
1911 if (mem_cgroup_is_root(mem))
1912 goto done;
1913 if (page_size == PAGE_SIZE && consume_stock(mem))
1914 goto done;
1915 css_get(&mem->css);
1916 } else {
1917 struct task_struct *p;
1919 rcu_read_lock();
1920 p = rcu_dereference(mm->owner);
1922 * Because we don't have task_lock(), "p" can exit.
1923 * In that case, "mem" can point to root or p can be NULL with
1924 * race with swapoff. Then, we have small risk of mis-accouning.
1925 * But such kind of mis-account by race always happens because
1926 * we don't have cgroup_mutex(). It's overkill and we allo that
1927 * small race, here.
1928 * (*) swapoff at el will charge against mm-struct not against
1929 * task-struct. So, mm->owner can be NULL.
1931 mem = mem_cgroup_from_task(p);
1932 if (!mem || mem_cgroup_is_root(mem)) {
1933 rcu_read_unlock();
1934 goto done;
1936 if (page_size == PAGE_SIZE && consume_stock(mem)) {
1938 * It seems dagerous to access memcg without css_get().
1939 * But considering how consume_stok works, it's not
1940 * necessary. If consume_stock success, some charges
1941 * from this memcg are cached on this cpu. So, we
1942 * don't need to call css_get()/css_tryget() before
1943 * calling consume_stock().
1945 rcu_read_unlock();
1946 goto done;
1948 /* after here, we may be blocked. we need to get refcnt */
1949 if (!css_tryget(&mem->css)) {
1950 rcu_read_unlock();
1951 goto again;
1953 rcu_read_unlock();
1956 do {
1957 bool oom_check;
1959 /* If killed, bypass charge */
1960 if (fatal_signal_pending(current)) {
1961 css_put(&mem->css);
1962 goto bypass;
1965 oom_check = false;
1966 if (oom && !nr_oom_retries) {
1967 oom_check = true;
1968 nr_oom_retries = MEM_CGROUP_RECLAIM_RETRIES;
1971 ret = __mem_cgroup_do_charge(mem, gfp_mask, csize, oom_check);
1973 switch (ret) {
1974 case CHARGE_OK:
1975 break;
1976 case CHARGE_RETRY: /* not in OOM situation but retry */
1977 csize = page_size;
1978 css_put(&mem->css);
1979 mem = NULL;
1980 goto again;
1981 case CHARGE_WOULDBLOCK: /* !__GFP_WAIT */
1982 css_put(&mem->css);
1983 goto nomem;
1984 case CHARGE_NOMEM: /* OOM routine works */
1985 if (!oom) {
1986 css_put(&mem->css);
1987 goto nomem;
1989 /* If oom, we never return -ENOMEM */
1990 nr_oom_retries--;
1991 break;
1992 case CHARGE_OOM_DIE: /* Killed by OOM Killer */
1993 css_put(&mem->css);
1994 goto bypass;
1996 } while (ret != CHARGE_OK);
1998 if (csize > page_size)
1999 refill_stock(mem, csize - page_size);
2000 css_put(&mem->css);
2001 done:
2002 *memcg = mem;
2003 return 0;
2004 nomem:
2005 *memcg = NULL;
2006 return -ENOMEM;
2007 bypass:
2008 *memcg = NULL;
2009 return 0;
2013 * Somemtimes we have to undo a charge we got by try_charge().
2014 * This function is for that and do uncharge, put css's refcnt.
2015 * gotten by try_charge().
2017 static void __mem_cgroup_cancel_charge(struct mem_cgroup *mem,
2018 unsigned long count)
2020 if (!mem_cgroup_is_root(mem)) {
2021 res_counter_uncharge(&mem->res, PAGE_SIZE * count);
2022 if (do_swap_account)
2023 res_counter_uncharge(&mem->memsw, PAGE_SIZE * count);
2027 static void mem_cgroup_cancel_charge(struct mem_cgroup *mem,
2028 int page_size)
2030 __mem_cgroup_cancel_charge(mem, page_size >> PAGE_SHIFT);
2034 * A helper function to get mem_cgroup from ID. must be called under
2035 * rcu_read_lock(). The caller must check css_is_removed() or some if
2036 * it's concern. (dropping refcnt from swap can be called against removed
2037 * memcg.)
2039 static struct mem_cgroup *mem_cgroup_lookup(unsigned short id)
2041 struct cgroup_subsys_state *css;
2043 /* ID 0 is unused ID */
2044 if (!id)
2045 return NULL;
2046 css = css_lookup(&mem_cgroup_subsys, id);
2047 if (!css)
2048 return NULL;
2049 return container_of(css, struct mem_cgroup, css);
2052 struct mem_cgroup *try_get_mem_cgroup_from_page(struct page *page)
2054 struct mem_cgroup *mem = NULL;
2055 struct page_cgroup *pc;
2056 unsigned short id;
2057 swp_entry_t ent;
2059 VM_BUG_ON(!PageLocked(page));
2061 pc = lookup_page_cgroup(page);
2062 lock_page_cgroup(pc);
2063 if (PageCgroupUsed(pc)) {
2064 mem = pc->mem_cgroup;
2065 if (mem && !css_tryget(&mem->css))
2066 mem = NULL;
2067 } else if (PageSwapCache(page)) {
2068 ent.val = page_private(page);
2069 id = lookup_swap_cgroup(ent);
2070 rcu_read_lock();
2071 mem = mem_cgroup_lookup(id);
2072 if (mem && !css_tryget(&mem->css))
2073 mem = NULL;
2074 rcu_read_unlock();
2076 unlock_page_cgroup(pc);
2077 return mem;
2080 static void __mem_cgroup_commit_charge(struct mem_cgroup *mem,
2081 struct page_cgroup *pc,
2082 enum charge_type ctype,
2083 int page_size)
2085 int nr_pages = page_size >> PAGE_SHIFT;
2087 /* try_charge() can return NULL to *memcg, taking care of it. */
2088 if (!mem)
2089 return;
2091 lock_page_cgroup(pc);
2092 if (unlikely(PageCgroupUsed(pc))) {
2093 unlock_page_cgroup(pc);
2094 mem_cgroup_cancel_charge(mem, page_size);
2095 return;
2098 * we don't need page_cgroup_lock about tail pages, becase they are not
2099 * accessed by any other context at this point.
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.
2109 smp_wmb();
2110 switch (ctype) {
2111 case MEM_CGROUP_CHARGE_TYPE_CACHE:
2112 case MEM_CGROUP_CHARGE_TYPE_SHMEM:
2113 SetPageCgroupCache(pc);
2114 SetPageCgroupUsed(pc);
2115 break;
2116 case MEM_CGROUP_CHARGE_TYPE_MAPPED:
2117 ClearPageCgroupCache(pc);
2118 SetPageCgroupUsed(pc);
2119 break;
2120 default:
2121 break;
2124 mem_cgroup_charge_statistics(mem, PageCgroupCache(pc), nr_pages);
2125 unlock_page_cgroup(pc);
2127 * "charge_statistics" updated event counter. Then, check it.
2128 * Insert ancestor (and ancestor's ancestors), to softlimit RB-tree.
2129 * if they exceeds softlimit.
2131 memcg_check_events(mem, pc->page);
2134 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
2136 #define PCGF_NOCOPY_AT_SPLIT ((1 << PCG_LOCK) | (1 << PCG_MOVE_LOCK) |\
2137 (1 << PCG_ACCT_LRU) | (1 << PCG_MIGRATION))
2139 * Because tail pages are not marked as "used", set it. We're under
2140 * zone->lru_lock, 'splitting on pmd' and compund_lock.
2142 void mem_cgroup_split_huge_fixup(struct page *head, struct page *tail)
2144 struct page_cgroup *head_pc = lookup_page_cgroup(head);
2145 struct page_cgroup *tail_pc = lookup_page_cgroup(tail);
2146 unsigned long flags;
2148 if (mem_cgroup_disabled())
2149 return;
2151 * We have no races with charge/uncharge but will have races with
2152 * page state accounting.
2154 move_lock_page_cgroup(head_pc, &flags);
2156 tail_pc->mem_cgroup = head_pc->mem_cgroup;
2157 smp_wmb(); /* see __commit_charge() */
2158 if (PageCgroupAcctLRU(head_pc)) {
2159 enum lru_list lru;
2160 struct mem_cgroup_per_zone *mz;
2163 * LRU flags cannot be copied because we need to add tail
2164 *.page to LRU by generic call and our hook will be called.
2165 * We hold lru_lock, then, reduce counter directly.
2167 lru = page_lru(head);
2168 mz = page_cgroup_zoneinfo(head_pc);
2169 MEM_CGROUP_ZSTAT(mz, lru) -= 1;
2171 tail_pc->flags = head_pc->flags & ~PCGF_NOCOPY_AT_SPLIT;
2172 move_unlock_page_cgroup(head_pc, &flags);
2174 #endif
2177 * __mem_cgroup_move_account - move account of the page
2178 * @pc: page_cgroup of the page.
2179 * @from: mem_cgroup which the page is moved from.
2180 * @to: mem_cgroup which the page is moved to. @from != @to.
2181 * @uncharge: whether we should call uncharge and css_put against @from.
2183 * The caller must confirm following.
2184 * - page is not on LRU (isolate_page() is useful.)
2185 * - the pc is locked, used, and ->mem_cgroup points to @from.
2187 * This function doesn't do "charge" nor css_get to new cgroup. It should be
2188 * done by a caller(__mem_cgroup_try_charge would be usefull). If @uncharge is
2189 * true, this function does "uncharge" from old cgroup, but it doesn't if
2190 * @uncharge is false, so a caller should do "uncharge".
2193 static void __mem_cgroup_move_account(struct page_cgroup *pc,
2194 struct mem_cgroup *from, struct mem_cgroup *to, bool uncharge,
2195 int charge_size)
2197 int nr_pages = charge_size >> PAGE_SHIFT;
2199 VM_BUG_ON(from == to);
2200 VM_BUG_ON(PageLRU(pc->page));
2201 VM_BUG_ON(!page_is_cgroup_locked(pc));
2202 VM_BUG_ON(!PageCgroupUsed(pc));
2203 VM_BUG_ON(pc->mem_cgroup != from);
2205 if (PageCgroupFileMapped(pc)) {
2206 /* Update mapped_file data for mem_cgroup */
2207 preempt_disable();
2208 __this_cpu_dec(from->stat->count[MEM_CGROUP_STAT_FILE_MAPPED]);
2209 __this_cpu_inc(to->stat->count[MEM_CGROUP_STAT_FILE_MAPPED]);
2210 preempt_enable();
2212 mem_cgroup_charge_statistics(from, PageCgroupCache(pc), -nr_pages);
2213 if (uncharge)
2214 /* This is not "cancel", but cancel_charge does all we need. */
2215 mem_cgroup_cancel_charge(from, charge_size);
2217 /* caller should have done css_get */
2218 pc->mem_cgroup = to;
2219 mem_cgroup_charge_statistics(to, PageCgroupCache(pc), nr_pages);
2221 * We charges against "to" which may not have any tasks. Then, "to"
2222 * can be under rmdir(). But in current implementation, caller of
2223 * this function is just force_empty() and move charge, so it's
2224 * garanteed that "to" is never removed. So, we don't check rmdir
2225 * status here.
2230 * check whether the @pc is valid for moving account and call
2231 * __mem_cgroup_move_account()
2233 static int mem_cgroup_move_account(struct page_cgroup *pc,
2234 struct mem_cgroup *from, struct mem_cgroup *to,
2235 bool uncharge, int charge_size)
2237 int ret = -EINVAL;
2238 unsigned long flags;
2240 * The page is isolated from LRU. So, collapse function
2241 * will not handle this page. But page splitting can happen.
2242 * Do this check under compound_page_lock(). The caller should
2243 * hold it.
2245 if ((charge_size > PAGE_SIZE) && !PageTransHuge(pc->page))
2246 return -EBUSY;
2248 lock_page_cgroup(pc);
2249 if (PageCgroupUsed(pc) && pc->mem_cgroup == from) {
2250 move_lock_page_cgroup(pc, &flags);
2251 __mem_cgroup_move_account(pc, from, to, uncharge, charge_size);
2252 move_unlock_page_cgroup(pc, &flags);
2253 ret = 0;
2255 unlock_page_cgroup(pc);
2257 * check events
2259 memcg_check_events(to, pc->page);
2260 memcg_check_events(from, pc->page);
2261 return ret;
2265 * move charges to its parent.
2268 static int mem_cgroup_move_parent(struct page_cgroup *pc,
2269 struct mem_cgroup *child,
2270 gfp_t gfp_mask)
2272 struct page *page = pc->page;
2273 struct cgroup *cg = child->css.cgroup;
2274 struct cgroup *pcg = cg->parent;
2275 struct mem_cgroup *parent;
2276 int page_size = PAGE_SIZE;
2277 unsigned long flags;
2278 int ret;
2280 /* Is ROOT ? */
2281 if (!pcg)
2282 return -EINVAL;
2284 ret = -EBUSY;
2285 if (!get_page_unless_zero(page))
2286 goto out;
2287 if (isolate_lru_page(page))
2288 goto put;
2290 if (PageTransHuge(page))
2291 page_size = HPAGE_SIZE;
2293 parent = mem_cgroup_from_cont(pcg);
2294 ret = __mem_cgroup_try_charge(NULL, gfp_mask,
2295 &parent, false, page_size);
2296 if (ret || !parent)
2297 goto put_back;
2299 if (page_size > PAGE_SIZE)
2300 flags = compound_lock_irqsave(page);
2302 ret = mem_cgroup_move_account(pc, child, parent, true, page_size);
2303 if (ret)
2304 mem_cgroup_cancel_charge(parent, page_size);
2306 if (page_size > PAGE_SIZE)
2307 compound_unlock_irqrestore(page, flags);
2308 put_back:
2309 putback_lru_page(page);
2310 put:
2311 put_page(page);
2312 out:
2313 return ret;
2317 * Charge the memory controller for page usage.
2318 * Return
2319 * 0 if the charge was successful
2320 * < 0 if the cgroup is over its limit
2322 static int mem_cgroup_charge_common(struct page *page, struct mm_struct *mm,
2323 gfp_t gfp_mask, enum charge_type ctype)
2325 struct mem_cgroup *mem = NULL;
2326 struct page_cgroup *pc;
2327 int ret;
2328 int page_size = PAGE_SIZE;
2330 if (PageTransHuge(page)) {
2331 page_size <<= compound_order(page);
2332 VM_BUG_ON(!PageTransHuge(page));
2335 pc = lookup_page_cgroup(page);
2336 /* can happen at boot */
2337 if (unlikely(!pc))
2338 return 0;
2339 prefetchw(pc);
2341 ret = __mem_cgroup_try_charge(mm, gfp_mask, &mem, true, page_size);
2342 if (ret || !mem)
2343 return ret;
2345 __mem_cgroup_commit_charge(mem, pc, ctype, page_size);
2346 return 0;
2349 int mem_cgroup_newpage_charge(struct page *page,
2350 struct mm_struct *mm, gfp_t gfp_mask)
2352 if (mem_cgroup_disabled())
2353 return 0;
2355 * If already mapped, we don't have to account.
2356 * If page cache, page->mapping has address_space.
2357 * But page->mapping may have out-of-use anon_vma pointer,
2358 * detecit it by PageAnon() check. newly-mapped-anon's page->mapping
2359 * is NULL.
2361 if (page_mapped(page) || (page->mapping && !PageAnon(page)))
2362 return 0;
2363 if (unlikely(!mm))
2364 mm = &init_mm;
2365 return mem_cgroup_charge_common(page, mm, gfp_mask,
2366 MEM_CGROUP_CHARGE_TYPE_MAPPED);
2369 static void
2370 __mem_cgroup_commit_charge_swapin(struct page *page, struct mem_cgroup *ptr,
2371 enum charge_type ctype);
2373 int mem_cgroup_cache_charge(struct page *page, struct mm_struct *mm,
2374 gfp_t gfp_mask)
2376 int ret;
2378 if (mem_cgroup_disabled())
2379 return 0;
2380 if (PageCompound(page))
2381 return 0;
2383 * Corner case handling. This is called from add_to_page_cache()
2384 * in usual. But some FS (shmem) precharges this page before calling it
2385 * and call add_to_page_cache() with GFP_NOWAIT.
2387 * For GFP_NOWAIT case, the page may be pre-charged before calling
2388 * add_to_page_cache(). (See shmem.c) check it here and avoid to call
2389 * charge twice. (It works but has to pay a bit larger cost.)
2390 * And when the page is SwapCache, it should take swap information
2391 * into account. This is under lock_page() now.
2393 if (!(gfp_mask & __GFP_WAIT)) {
2394 struct page_cgroup *pc;
2396 pc = lookup_page_cgroup(page);
2397 if (!pc)
2398 return 0;
2399 lock_page_cgroup(pc);
2400 if (PageCgroupUsed(pc)) {
2401 unlock_page_cgroup(pc);
2402 return 0;
2404 unlock_page_cgroup(pc);
2407 if (unlikely(!mm))
2408 mm = &init_mm;
2410 if (page_is_file_cache(page))
2411 return mem_cgroup_charge_common(page, mm, gfp_mask,
2412 MEM_CGROUP_CHARGE_TYPE_CACHE);
2414 /* shmem */
2415 if (PageSwapCache(page)) {
2416 struct mem_cgroup *mem = NULL;
2418 ret = mem_cgroup_try_charge_swapin(mm, page, gfp_mask, &mem);
2419 if (!ret)
2420 __mem_cgroup_commit_charge_swapin(page, mem,
2421 MEM_CGROUP_CHARGE_TYPE_SHMEM);
2422 } else
2423 ret = mem_cgroup_charge_common(page, mm, gfp_mask,
2424 MEM_CGROUP_CHARGE_TYPE_SHMEM);
2426 return ret;
2430 * While swap-in, try_charge -> commit or cancel, the page is locked.
2431 * And when try_charge() successfully returns, one refcnt to memcg without
2432 * struct page_cgroup is acquired. This refcnt will be consumed by
2433 * "commit()" or removed by "cancel()"
2435 int mem_cgroup_try_charge_swapin(struct mm_struct *mm,
2436 struct page *page,
2437 gfp_t mask, struct mem_cgroup **ptr)
2439 struct mem_cgroup *mem;
2440 int ret;
2442 if (mem_cgroup_disabled())
2443 return 0;
2445 if (!do_swap_account)
2446 goto charge_cur_mm;
2448 * A racing thread's fault, or swapoff, may have already updated
2449 * the pte, and even removed page from swap cache: in those cases
2450 * do_swap_page()'s pte_same() test will fail; but there's also a
2451 * KSM case which does need to charge the page.
2453 if (!PageSwapCache(page))
2454 goto charge_cur_mm;
2455 mem = try_get_mem_cgroup_from_page(page);
2456 if (!mem)
2457 goto charge_cur_mm;
2458 *ptr = mem;
2459 ret = __mem_cgroup_try_charge(NULL, mask, ptr, true, PAGE_SIZE);
2460 css_put(&mem->css);
2461 return ret;
2462 charge_cur_mm:
2463 if (unlikely(!mm))
2464 mm = &init_mm;
2465 return __mem_cgroup_try_charge(mm, mask, ptr, true, PAGE_SIZE);
2468 static void
2469 __mem_cgroup_commit_charge_swapin(struct page *page, struct mem_cgroup *ptr,
2470 enum charge_type ctype)
2472 struct page_cgroup *pc;
2474 if (mem_cgroup_disabled())
2475 return;
2476 if (!ptr)
2477 return;
2478 cgroup_exclude_rmdir(&ptr->css);
2479 pc = lookup_page_cgroup(page);
2480 mem_cgroup_lru_del_before_commit_swapcache(page);
2481 __mem_cgroup_commit_charge(ptr, pc, ctype, PAGE_SIZE);
2482 mem_cgroup_lru_add_after_commit_swapcache(page);
2484 * Now swap is on-memory. This means this page may be
2485 * counted both as mem and swap....double count.
2486 * Fix it by uncharging from memsw. Basically, this SwapCache is stable
2487 * under lock_page(). But in do_swap_page()::memory.c, reuse_swap_page()
2488 * may call delete_from_swap_cache() before reach here.
2490 if (do_swap_account && PageSwapCache(page)) {
2491 swp_entry_t ent = {.val = page_private(page)};
2492 unsigned short id;
2493 struct mem_cgroup *memcg;
2495 id = swap_cgroup_record(ent, 0);
2496 rcu_read_lock();
2497 memcg = mem_cgroup_lookup(id);
2498 if (memcg) {
2500 * This recorded memcg can be obsolete one. So, avoid
2501 * calling css_tryget
2503 if (!mem_cgroup_is_root(memcg))
2504 res_counter_uncharge(&memcg->memsw, PAGE_SIZE);
2505 mem_cgroup_swap_statistics(memcg, false);
2506 mem_cgroup_put(memcg);
2508 rcu_read_unlock();
2511 * At swapin, we may charge account against cgroup which has no tasks.
2512 * So, rmdir()->pre_destroy() can be called while we do this charge.
2513 * In that case, we need to call pre_destroy() again. check it here.
2515 cgroup_release_and_wakeup_rmdir(&ptr->css);
2518 void mem_cgroup_commit_charge_swapin(struct page *page, struct mem_cgroup *ptr)
2520 __mem_cgroup_commit_charge_swapin(page, ptr,
2521 MEM_CGROUP_CHARGE_TYPE_MAPPED);
2524 void mem_cgroup_cancel_charge_swapin(struct mem_cgroup *mem)
2526 if (mem_cgroup_disabled())
2527 return;
2528 if (!mem)
2529 return;
2530 mem_cgroup_cancel_charge(mem, PAGE_SIZE);
2533 static void
2534 __do_uncharge(struct mem_cgroup *mem, const enum charge_type ctype,
2535 int page_size)
2537 struct memcg_batch_info *batch = NULL;
2538 bool uncharge_memsw = true;
2539 /* If swapout, usage of swap doesn't decrease */
2540 if (!do_swap_account || ctype == MEM_CGROUP_CHARGE_TYPE_SWAPOUT)
2541 uncharge_memsw = false;
2543 batch = &current->memcg_batch;
2545 * In usual, we do css_get() when we remember memcg pointer.
2546 * But in this case, we keep res->usage until end of a series of
2547 * uncharges. Then, it's ok to ignore memcg's refcnt.
2549 if (!batch->memcg)
2550 batch->memcg = mem;
2552 * do_batch > 0 when unmapping pages or inode invalidate/truncate.
2553 * In those cases, all pages freed continously can be expected to be in
2554 * the same cgroup and we have chance to coalesce uncharges.
2555 * But we do uncharge one by one if this is killed by OOM(TIF_MEMDIE)
2556 * because we want to do uncharge as soon as possible.
2559 if (!batch->do_batch || test_thread_flag(TIF_MEMDIE))
2560 goto direct_uncharge;
2562 if (page_size != PAGE_SIZE)
2563 goto direct_uncharge;
2566 * In typical case, batch->memcg == mem. This means we can
2567 * merge a series of uncharges to an uncharge of res_counter.
2568 * If not, we uncharge res_counter ony by one.
2570 if (batch->memcg != mem)
2571 goto direct_uncharge;
2572 /* remember freed charge and uncharge it later */
2573 batch->bytes += PAGE_SIZE;
2574 if (uncharge_memsw)
2575 batch->memsw_bytes += PAGE_SIZE;
2576 return;
2577 direct_uncharge:
2578 res_counter_uncharge(&mem->res, page_size);
2579 if (uncharge_memsw)
2580 res_counter_uncharge(&mem->memsw, page_size);
2581 if (unlikely(batch->memcg != mem))
2582 memcg_oom_recover(mem);
2583 return;
2587 * uncharge if !page_mapped(page)
2589 static struct mem_cgroup *
2590 __mem_cgroup_uncharge_common(struct page *page, enum charge_type ctype)
2592 int count;
2593 struct page_cgroup *pc;
2594 struct mem_cgroup *mem = NULL;
2595 int page_size = PAGE_SIZE;
2597 if (mem_cgroup_disabled())
2598 return NULL;
2600 if (PageSwapCache(page))
2601 return NULL;
2603 if (PageTransHuge(page)) {
2604 page_size <<= compound_order(page);
2605 VM_BUG_ON(!PageTransHuge(page));
2608 count = page_size >> PAGE_SHIFT;
2610 * Check if our page_cgroup is valid
2612 pc = lookup_page_cgroup(page);
2613 if (unlikely(!pc || !PageCgroupUsed(pc)))
2614 return NULL;
2616 lock_page_cgroup(pc);
2618 mem = pc->mem_cgroup;
2620 if (!PageCgroupUsed(pc))
2621 goto unlock_out;
2623 switch (ctype) {
2624 case MEM_CGROUP_CHARGE_TYPE_MAPPED:
2625 case MEM_CGROUP_CHARGE_TYPE_DROP:
2626 /* See mem_cgroup_prepare_migration() */
2627 if (page_mapped(page) || PageCgroupMigration(pc))
2628 goto unlock_out;
2629 break;
2630 case MEM_CGROUP_CHARGE_TYPE_SWAPOUT:
2631 if (!PageAnon(page)) { /* Shared memory */
2632 if (page->mapping && !page_is_file_cache(page))
2633 goto unlock_out;
2634 } else if (page_mapped(page)) /* Anon */
2635 goto unlock_out;
2636 break;
2637 default:
2638 break;
2641 mem_cgroup_charge_statistics(mem, PageCgroupCache(pc), -count);
2643 ClearPageCgroupUsed(pc);
2645 * pc->mem_cgroup is not cleared here. It will be accessed when it's
2646 * freed from LRU. This is safe because uncharged page is expected not
2647 * to be reused (freed soon). Exception is SwapCache, it's handled by
2648 * special functions.
2651 unlock_page_cgroup(pc);
2653 * even after unlock, we have mem->res.usage here and this memcg
2654 * will never be freed.
2656 memcg_check_events(mem, page);
2657 if (do_swap_account && ctype == MEM_CGROUP_CHARGE_TYPE_SWAPOUT) {
2658 mem_cgroup_swap_statistics(mem, true);
2659 mem_cgroup_get(mem);
2661 if (!mem_cgroup_is_root(mem))
2662 __do_uncharge(mem, ctype, page_size);
2664 return mem;
2666 unlock_out:
2667 unlock_page_cgroup(pc);
2668 return NULL;
2671 void mem_cgroup_uncharge_page(struct page *page)
2673 /* early check. */
2674 if (page_mapped(page))
2675 return;
2676 if (page->mapping && !PageAnon(page))
2677 return;
2678 __mem_cgroup_uncharge_common(page, MEM_CGROUP_CHARGE_TYPE_MAPPED);
2681 void mem_cgroup_uncharge_cache_page(struct page *page)
2683 VM_BUG_ON(page_mapped(page));
2684 VM_BUG_ON(page->mapping);
2685 __mem_cgroup_uncharge_common(page, MEM_CGROUP_CHARGE_TYPE_CACHE);
2689 * Batch_start/batch_end is called in unmap_page_range/invlidate/trucate.
2690 * In that cases, pages are freed continuously and we can expect pages
2691 * are in the same memcg. All these calls itself limits the number of
2692 * pages freed at once, then uncharge_start/end() is called properly.
2693 * This may be called prural(2) times in a context,
2696 void mem_cgroup_uncharge_start(void)
2698 current->memcg_batch.do_batch++;
2699 /* We can do nest. */
2700 if (current->memcg_batch.do_batch == 1) {
2701 current->memcg_batch.memcg = NULL;
2702 current->memcg_batch.bytes = 0;
2703 current->memcg_batch.memsw_bytes = 0;
2707 void mem_cgroup_uncharge_end(void)
2709 struct memcg_batch_info *batch = &current->memcg_batch;
2711 if (!batch->do_batch)
2712 return;
2714 batch->do_batch--;
2715 if (batch->do_batch) /* If stacked, do nothing. */
2716 return;
2718 if (!batch->memcg)
2719 return;
2721 * This "batch->memcg" is valid without any css_get/put etc...
2722 * bacause we hide charges behind us.
2724 if (batch->bytes)
2725 res_counter_uncharge(&batch->memcg->res, batch->bytes);
2726 if (batch->memsw_bytes)
2727 res_counter_uncharge(&batch->memcg->memsw, batch->memsw_bytes);
2728 memcg_oom_recover(batch->memcg);
2729 /* forget this pointer (for sanity check) */
2730 batch->memcg = NULL;
2733 #ifdef CONFIG_SWAP
2735 * called after __delete_from_swap_cache() and drop "page" account.
2736 * memcg information is recorded to swap_cgroup of "ent"
2738 void
2739 mem_cgroup_uncharge_swapcache(struct page *page, swp_entry_t ent, bool swapout)
2741 struct mem_cgroup *memcg;
2742 int ctype = MEM_CGROUP_CHARGE_TYPE_SWAPOUT;
2744 if (!swapout) /* this was a swap cache but the swap is unused ! */
2745 ctype = MEM_CGROUP_CHARGE_TYPE_DROP;
2747 memcg = __mem_cgroup_uncharge_common(page, ctype);
2750 * record memcg information, if swapout && memcg != NULL,
2751 * mem_cgroup_get() was called in uncharge().
2753 if (do_swap_account && swapout && memcg)
2754 swap_cgroup_record(ent, css_id(&memcg->css));
2756 #endif
2758 #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP
2760 * called from swap_entry_free(). remove record in swap_cgroup and
2761 * uncharge "memsw" account.
2763 void mem_cgroup_uncharge_swap(swp_entry_t ent)
2765 struct mem_cgroup *memcg;
2766 unsigned short id;
2768 if (!do_swap_account)
2769 return;
2771 id = swap_cgroup_record(ent, 0);
2772 rcu_read_lock();
2773 memcg = mem_cgroup_lookup(id);
2774 if (memcg) {
2776 * We uncharge this because swap is freed.
2777 * This memcg can be obsolete one. We avoid calling css_tryget
2779 if (!mem_cgroup_is_root(memcg))
2780 res_counter_uncharge(&memcg->memsw, PAGE_SIZE);
2781 mem_cgroup_swap_statistics(memcg, false);
2782 mem_cgroup_put(memcg);
2784 rcu_read_unlock();
2788 * mem_cgroup_move_swap_account - move swap charge and swap_cgroup's record.
2789 * @entry: swap entry to be moved
2790 * @from: mem_cgroup which the entry is moved from
2791 * @to: mem_cgroup which the entry is moved to
2792 * @need_fixup: whether we should fixup res_counters and refcounts.
2794 * It succeeds only when the swap_cgroup's record for this entry is the same
2795 * as the mem_cgroup's id of @from.
2797 * Returns 0 on success, -EINVAL on failure.
2799 * The caller must have charged to @to, IOW, called res_counter_charge() about
2800 * both res and memsw, and called css_get().
2802 static int mem_cgroup_move_swap_account(swp_entry_t entry,
2803 struct mem_cgroup *from, struct mem_cgroup *to, bool need_fixup)
2805 unsigned short old_id, new_id;
2807 old_id = css_id(&from->css);
2808 new_id = css_id(&to->css);
2810 if (swap_cgroup_cmpxchg(entry, old_id, new_id) == old_id) {
2811 mem_cgroup_swap_statistics(from, false);
2812 mem_cgroup_swap_statistics(to, true);
2814 * This function is only called from task migration context now.
2815 * It postpones res_counter and refcount handling till the end
2816 * of task migration(mem_cgroup_clear_mc()) for performance
2817 * improvement. But we cannot postpone mem_cgroup_get(to)
2818 * because if the process that has been moved to @to does
2819 * swap-in, the refcount of @to might be decreased to 0.
2821 mem_cgroup_get(to);
2822 if (need_fixup) {
2823 if (!mem_cgroup_is_root(from))
2824 res_counter_uncharge(&from->memsw, PAGE_SIZE);
2825 mem_cgroup_put(from);
2827 * we charged both to->res and to->memsw, so we should
2828 * uncharge to->res.
2830 if (!mem_cgroup_is_root(to))
2831 res_counter_uncharge(&to->res, PAGE_SIZE);
2833 return 0;
2835 return -EINVAL;
2837 #else
2838 static inline int mem_cgroup_move_swap_account(swp_entry_t entry,
2839 struct mem_cgroup *from, struct mem_cgroup *to, bool need_fixup)
2841 return -EINVAL;
2843 #endif
2846 * Before starting migration, account PAGE_SIZE to mem_cgroup that the old
2847 * page belongs to.
2849 int mem_cgroup_prepare_migration(struct page *page,
2850 struct page *newpage, struct mem_cgroup **ptr)
2852 struct page_cgroup *pc;
2853 struct mem_cgroup *mem = NULL;
2854 enum charge_type ctype;
2855 int ret = 0;
2857 VM_BUG_ON(PageTransHuge(page));
2858 if (mem_cgroup_disabled())
2859 return 0;
2861 pc = lookup_page_cgroup(page);
2862 lock_page_cgroup(pc);
2863 if (PageCgroupUsed(pc)) {
2864 mem = pc->mem_cgroup;
2865 css_get(&mem->css);
2867 * At migrating an anonymous page, its mapcount goes down
2868 * to 0 and uncharge() will be called. But, even if it's fully
2869 * unmapped, migration may fail and this page has to be
2870 * charged again. We set MIGRATION flag here and delay uncharge
2871 * until end_migration() is called
2873 * Corner Case Thinking
2874 * A)
2875 * When the old page was mapped as Anon and it's unmap-and-freed
2876 * while migration was ongoing.
2877 * If unmap finds the old page, uncharge() of it will be delayed
2878 * until end_migration(). If unmap finds a new page, it's
2879 * uncharged when it make mapcount to be 1->0. If unmap code
2880 * finds swap_migration_entry, the new page will not be mapped
2881 * and end_migration() will find it(mapcount==0).
2883 * B)
2884 * When the old page was mapped but migraion fails, the kernel
2885 * remaps it. A charge for it is kept by MIGRATION flag even
2886 * if mapcount goes down to 0. We can do remap successfully
2887 * without charging it again.
2889 * C)
2890 * The "old" page is under lock_page() until the end of
2891 * migration, so, the old page itself will not be swapped-out.
2892 * If the new page is swapped out before end_migraton, our
2893 * hook to usual swap-out path will catch the event.
2895 if (PageAnon(page))
2896 SetPageCgroupMigration(pc);
2898 unlock_page_cgroup(pc);
2900 * If the page is not charged at this point,
2901 * we return here.
2903 if (!mem)
2904 return 0;
2906 *ptr = mem;
2907 ret = __mem_cgroup_try_charge(NULL, GFP_KERNEL, ptr, false, PAGE_SIZE);
2908 css_put(&mem->css);/* drop extra refcnt */
2909 if (ret || *ptr == NULL) {
2910 if (PageAnon(page)) {
2911 lock_page_cgroup(pc);
2912 ClearPageCgroupMigration(pc);
2913 unlock_page_cgroup(pc);
2915 * The old page may be fully unmapped while we kept it.
2917 mem_cgroup_uncharge_page(page);
2919 return -ENOMEM;
2922 * We charge new page before it's used/mapped. So, even if unlock_page()
2923 * is called before end_migration, we can catch all events on this new
2924 * page. In the case new page is migrated but not remapped, new page's
2925 * mapcount will be finally 0 and we call uncharge in end_migration().
2927 pc = lookup_page_cgroup(newpage);
2928 if (PageAnon(page))
2929 ctype = MEM_CGROUP_CHARGE_TYPE_MAPPED;
2930 else if (page_is_file_cache(page))
2931 ctype = MEM_CGROUP_CHARGE_TYPE_CACHE;
2932 else
2933 ctype = MEM_CGROUP_CHARGE_TYPE_SHMEM;
2934 __mem_cgroup_commit_charge(mem, pc, ctype, PAGE_SIZE);
2935 return ret;
2938 /* remove redundant charge if migration failed*/
2939 void mem_cgroup_end_migration(struct mem_cgroup *mem,
2940 struct page *oldpage, struct page *newpage, bool migration_ok)
2942 struct page *used, *unused;
2943 struct page_cgroup *pc;
2945 if (!mem)
2946 return;
2947 /* blocks rmdir() */
2948 cgroup_exclude_rmdir(&mem->css);
2949 if (!migration_ok) {
2950 used = oldpage;
2951 unused = newpage;
2952 } else {
2953 used = newpage;
2954 unused = oldpage;
2957 * We disallowed uncharge of pages under migration because mapcount
2958 * of the page goes down to zero, temporarly.
2959 * Clear the flag and check the page should be charged.
2961 pc = lookup_page_cgroup(oldpage);
2962 lock_page_cgroup(pc);
2963 ClearPageCgroupMigration(pc);
2964 unlock_page_cgroup(pc);
2966 __mem_cgroup_uncharge_common(unused, MEM_CGROUP_CHARGE_TYPE_FORCE);
2969 * If a page is a file cache, radix-tree replacement is very atomic
2970 * and we can skip this check. When it was an Anon page, its mapcount
2971 * goes down to 0. But because we added MIGRATION flage, it's not
2972 * uncharged yet. There are several case but page->mapcount check
2973 * and USED bit check in mem_cgroup_uncharge_page() will do enough
2974 * check. (see prepare_charge() also)
2976 if (PageAnon(used))
2977 mem_cgroup_uncharge_page(used);
2979 * At migration, we may charge account against cgroup which has no
2980 * tasks.
2981 * So, rmdir()->pre_destroy() can be called while we do this charge.
2982 * In that case, we need to call pre_destroy() again. check it here.
2984 cgroup_release_and_wakeup_rmdir(&mem->css);
2988 * A call to try to shrink memory usage on charge failure at shmem's swapin.
2989 * Calling hierarchical_reclaim is not enough because we should update
2990 * last_oom_jiffies to prevent pagefault_out_of_memory from invoking global OOM.
2991 * Moreover considering hierarchy, we should reclaim from the mem_over_limit,
2992 * not from the memcg which this page would be charged to.
2993 * try_charge_swapin does all of these works properly.
2995 int mem_cgroup_shmem_charge_fallback(struct page *page,
2996 struct mm_struct *mm,
2997 gfp_t gfp_mask)
2999 struct mem_cgroup *mem = NULL;
3000 int ret;
3002 if (mem_cgroup_disabled())
3003 return 0;
3005 ret = mem_cgroup_try_charge_swapin(mm, page, gfp_mask, &mem);
3006 if (!ret)
3007 mem_cgroup_cancel_charge_swapin(mem); /* it does !mem check */
3009 return ret;
3012 static DEFINE_MUTEX(set_limit_mutex);
3014 static int mem_cgroup_resize_limit(struct mem_cgroup *memcg,
3015 unsigned long long val)
3017 int retry_count;
3018 u64 memswlimit, memlimit;
3019 int ret = 0;
3020 int children = mem_cgroup_count_children(memcg);
3021 u64 curusage, oldusage;
3022 int enlarge;
3025 * For keeping hierarchical_reclaim simple, how long we should retry
3026 * is depends on callers. We set our retry-count to be function
3027 * of # of children which we should visit in this loop.
3029 retry_count = MEM_CGROUP_RECLAIM_RETRIES * children;
3031 oldusage = res_counter_read_u64(&memcg->res, RES_USAGE);
3033 enlarge = 0;
3034 while (retry_count) {
3035 if (signal_pending(current)) {
3036 ret = -EINTR;
3037 break;
3040 * Rather than hide all in some function, I do this in
3041 * open coded manner. You see what this really does.
3042 * We have to guarantee mem->res.limit < mem->memsw.limit.
3044 mutex_lock(&set_limit_mutex);
3045 memswlimit = res_counter_read_u64(&memcg->memsw, RES_LIMIT);
3046 if (memswlimit < val) {
3047 ret = -EINVAL;
3048 mutex_unlock(&set_limit_mutex);
3049 break;
3052 memlimit = res_counter_read_u64(&memcg->res, RES_LIMIT);
3053 if (memlimit < val)
3054 enlarge = 1;
3056 ret = res_counter_set_limit(&memcg->res, val);
3057 if (!ret) {
3058 if (memswlimit == val)
3059 memcg->memsw_is_minimum = true;
3060 else
3061 memcg->memsw_is_minimum = false;
3063 mutex_unlock(&set_limit_mutex);
3065 if (!ret)
3066 break;
3068 mem_cgroup_hierarchical_reclaim(memcg, NULL, GFP_KERNEL,
3069 MEM_CGROUP_RECLAIM_SHRINK);
3070 curusage = res_counter_read_u64(&memcg->res, RES_USAGE);
3071 /* Usage is reduced ? */
3072 if (curusage >= oldusage)
3073 retry_count--;
3074 else
3075 oldusage = curusage;
3077 if (!ret && enlarge)
3078 memcg_oom_recover(memcg);
3080 return ret;
3083 static int mem_cgroup_resize_memsw_limit(struct mem_cgroup *memcg,
3084 unsigned long long val)
3086 int retry_count;
3087 u64 memlimit, memswlimit, oldusage, curusage;
3088 int children = mem_cgroup_count_children(memcg);
3089 int ret = -EBUSY;
3090 int enlarge = 0;
3092 /* see mem_cgroup_resize_res_limit */
3093 retry_count = children * MEM_CGROUP_RECLAIM_RETRIES;
3094 oldusage = res_counter_read_u64(&memcg->memsw, RES_USAGE);
3095 while (retry_count) {
3096 if (signal_pending(current)) {
3097 ret = -EINTR;
3098 break;
3101 * Rather than hide all in some function, I do this in
3102 * open coded manner. You see what this really does.
3103 * We have to guarantee mem->res.limit < mem->memsw.limit.
3105 mutex_lock(&set_limit_mutex);
3106 memlimit = res_counter_read_u64(&memcg->res, RES_LIMIT);
3107 if (memlimit > val) {
3108 ret = -EINVAL;
3109 mutex_unlock(&set_limit_mutex);
3110 break;
3112 memswlimit = res_counter_read_u64(&memcg->memsw, RES_LIMIT);
3113 if (memswlimit < val)
3114 enlarge = 1;
3115 ret = res_counter_set_limit(&memcg->memsw, val);
3116 if (!ret) {
3117 if (memlimit == val)
3118 memcg->memsw_is_minimum = true;
3119 else
3120 memcg->memsw_is_minimum = false;
3122 mutex_unlock(&set_limit_mutex);
3124 if (!ret)
3125 break;
3127 mem_cgroup_hierarchical_reclaim(memcg, NULL, GFP_KERNEL,
3128 MEM_CGROUP_RECLAIM_NOSWAP |
3129 MEM_CGROUP_RECLAIM_SHRINK);
3130 curusage = res_counter_read_u64(&memcg->memsw, RES_USAGE);
3131 /* Usage is reduced ? */
3132 if (curusage >= oldusage)
3133 retry_count--;
3134 else
3135 oldusage = curusage;
3137 if (!ret && enlarge)
3138 memcg_oom_recover(memcg);
3139 return ret;
3142 unsigned long mem_cgroup_soft_limit_reclaim(struct zone *zone, int order,
3143 gfp_t gfp_mask)
3145 unsigned long nr_reclaimed = 0;
3146 struct mem_cgroup_per_zone *mz, *next_mz = NULL;
3147 unsigned long reclaimed;
3148 int loop = 0;
3149 struct mem_cgroup_tree_per_zone *mctz;
3150 unsigned long long excess;
3152 if (order > 0)
3153 return 0;
3155 mctz = soft_limit_tree_node_zone(zone_to_nid(zone), zone_idx(zone));
3157 * This loop can run a while, specially if mem_cgroup's continuously
3158 * keep exceeding their soft limit and putting the system under
3159 * pressure
3161 do {
3162 if (next_mz)
3163 mz = next_mz;
3164 else
3165 mz = mem_cgroup_largest_soft_limit_node(mctz);
3166 if (!mz)
3167 break;
3169 reclaimed = mem_cgroup_hierarchical_reclaim(mz->mem, zone,
3170 gfp_mask,
3171 MEM_CGROUP_RECLAIM_SOFT);
3172 nr_reclaimed += reclaimed;
3173 spin_lock(&mctz->lock);
3176 * If we failed to reclaim anything from this memory cgroup
3177 * it is time to move on to the next cgroup
3179 next_mz = NULL;
3180 if (!reclaimed) {
3181 do {
3183 * Loop until we find yet another one.
3185 * By the time we get the soft_limit lock
3186 * again, someone might have aded the
3187 * group back on the RB tree. Iterate to
3188 * make sure we get a different mem.
3189 * mem_cgroup_largest_soft_limit_node returns
3190 * NULL if no other cgroup is present on
3191 * the tree
3193 next_mz =
3194 __mem_cgroup_largest_soft_limit_node(mctz);
3195 if (next_mz == mz) {
3196 css_put(&next_mz->mem->css);
3197 next_mz = NULL;
3198 } else /* next_mz == NULL or other memcg */
3199 break;
3200 } while (1);
3202 __mem_cgroup_remove_exceeded(mz->mem, mz, mctz);
3203 excess = res_counter_soft_limit_excess(&mz->mem->res);
3205 * One school of thought says that we should not add
3206 * back the node to the tree if reclaim returns 0.
3207 * But our reclaim could return 0, simply because due
3208 * to priority we are exposing a smaller subset of
3209 * memory to reclaim from. Consider this as a longer
3210 * term TODO.
3212 /* If excess == 0, no tree ops */
3213 __mem_cgroup_insert_exceeded(mz->mem, mz, mctz, excess);
3214 spin_unlock(&mctz->lock);
3215 css_put(&mz->mem->css);
3216 loop++;
3218 * Could not reclaim anything and there are no more
3219 * mem cgroups to try or we seem to be looping without
3220 * reclaiming anything.
3222 if (!nr_reclaimed &&
3223 (next_mz == NULL ||
3224 loop > MEM_CGROUP_MAX_SOFT_LIMIT_RECLAIM_LOOPS))
3225 break;
3226 } while (!nr_reclaimed);
3227 if (next_mz)
3228 css_put(&next_mz->mem->css);
3229 return nr_reclaimed;
3233 * This routine traverse page_cgroup in given list and drop them all.
3234 * *And* this routine doesn't reclaim page itself, just removes page_cgroup.
3236 static int mem_cgroup_force_empty_list(struct mem_cgroup *mem,
3237 int node, int zid, enum lru_list lru)
3239 struct zone *zone;
3240 struct mem_cgroup_per_zone *mz;
3241 struct page_cgroup *pc, *busy;
3242 unsigned long flags, loop;
3243 struct list_head *list;
3244 int ret = 0;
3246 zone = &NODE_DATA(node)->node_zones[zid];
3247 mz = mem_cgroup_zoneinfo(mem, node, zid);
3248 list = &mz->lists[lru];
3250 loop = MEM_CGROUP_ZSTAT(mz, lru);
3251 /* give some margin against EBUSY etc...*/
3252 loop += 256;
3253 busy = NULL;
3254 while (loop--) {
3255 ret = 0;
3256 spin_lock_irqsave(&zone->lru_lock, flags);
3257 if (list_empty(list)) {
3258 spin_unlock_irqrestore(&zone->lru_lock, flags);
3259 break;
3261 pc = list_entry(list->prev, struct page_cgroup, lru);
3262 if (busy == pc) {
3263 list_move(&pc->lru, list);
3264 busy = NULL;
3265 spin_unlock_irqrestore(&zone->lru_lock, flags);
3266 continue;
3268 spin_unlock_irqrestore(&zone->lru_lock, flags);
3270 ret = mem_cgroup_move_parent(pc, mem, GFP_KERNEL);
3271 if (ret == -ENOMEM)
3272 break;
3274 if (ret == -EBUSY || ret == -EINVAL) {
3275 /* found lock contention or "pc" is obsolete. */
3276 busy = pc;
3277 cond_resched();
3278 } else
3279 busy = NULL;
3282 if (!ret && !list_empty(list))
3283 return -EBUSY;
3284 return ret;
3288 * make mem_cgroup's charge to be 0 if there is no task.
3289 * This enables deleting this mem_cgroup.
3291 static int mem_cgroup_force_empty(struct mem_cgroup *mem, bool free_all)
3293 int ret;
3294 int node, zid, shrink;
3295 int nr_retries = MEM_CGROUP_RECLAIM_RETRIES;
3296 struct cgroup *cgrp = mem->css.cgroup;
3298 css_get(&mem->css);
3300 shrink = 0;
3301 /* should free all ? */
3302 if (free_all)
3303 goto try_to_free;
3304 move_account:
3305 do {
3306 ret = -EBUSY;
3307 if (cgroup_task_count(cgrp) || !list_empty(&cgrp->children))
3308 goto out;
3309 ret = -EINTR;
3310 if (signal_pending(current))
3311 goto out;
3312 /* This is for making all *used* pages to be on LRU. */
3313 lru_add_drain_all();
3314 drain_all_stock_sync();
3315 ret = 0;
3316 mem_cgroup_start_move(mem);
3317 for_each_node_state(node, N_HIGH_MEMORY) {
3318 for (zid = 0; !ret && zid < MAX_NR_ZONES; zid++) {
3319 enum lru_list l;
3320 for_each_lru(l) {
3321 ret = mem_cgroup_force_empty_list(mem,
3322 node, zid, l);
3323 if (ret)
3324 break;
3327 if (ret)
3328 break;
3330 mem_cgroup_end_move(mem);
3331 memcg_oom_recover(mem);
3332 /* it seems parent cgroup doesn't have enough mem */
3333 if (ret == -ENOMEM)
3334 goto try_to_free;
3335 cond_resched();
3336 /* "ret" should also be checked to ensure all lists are empty. */
3337 } while (mem->res.usage > 0 || ret);
3338 out:
3339 css_put(&mem->css);
3340 return ret;
3342 try_to_free:
3343 /* returns EBUSY if there is a task or if we come here twice. */
3344 if (cgroup_task_count(cgrp) || !list_empty(&cgrp->children) || shrink) {
3345 ret = -EBUSY;
3346 goto out;
3348 /* we call try-to-free pages for make this cgroup empty */
3349 lru_add_drain_all();
3350 /* try to free all pages in this cgroup */
3351 shrink = 1;
3352 while (nr_retries && mem->res.usage > 0) {
3353 int progress;
3355 if (signal_pending(current)) {
3356 ret = -EINTR;
3357 goto out;
3359 progress = try_to_free_mem_cgroup_pages(mem, GFP_KERNEL,
3360 false, get_swappiness(mem));
3361 if (!progress) {
3362 nr_retries--;
3363 /* maybe some writeback is necessary */
3364 congestion_wait(BLK_RW_ASYNC, HZ/10);
3368 lru_add_drain();
3369 /* try move_account...there may be some *locked* pages. */
3370 goto move_account;
3373 int mem_cgroup_force_empty_write(struct cgroup *cont, unsigned int event)
3375 return mem_cgroup_force_empty(mem_cgroup_from_cont(cont), true);
3379 static u64 mem_cgroup_hierarchy_read(struct cgroup *cont, struct cftype *cft)
3381 return mem_cgroup_from_cont(cont)->use_hierarchy;
3384 static int mem_cgroup_hierarchy_write(struct cgroup *cont, struct cftype *cft,
3385 u64 val)
3387 int retval = 0;
3388 struct mem_cgroup *mem = mem_cgroup_from_cont(cont);
3389 struct cgroup *parent = cont->parent;
3390 struct mem_cgroup *parent_mem = NULL;
3392 if (parent)
3393 parent_mem = mem_cgroup_from_cont(parent);
3395 cgroup_lock();
3397 * If parent's use_hierarchy is set, we can't make any modifications
3398 * in the child subtrees. If it is unset, then the change can
3399 * occur, provided the current cgroup has no children.
3401 * For the root cgroup, parent_mem is NULL, we allow value to be
3402 * set if there are no children.
3404 if ((!parent_mem || !parent_mem->use_hierarchy) &&
3405 (val == 1 || val == 0)) {
3406 if (list_empty(&cont->children))
3407 mem->use_hierarchy = val;
3408 else
3409 retval = -EBUSY;
3410 } else
3411 retval = -EINVAL;
3412 cgroup_unlock();
3414 return retval;
3418 static u64 mem_cgroup_get_recursive_idx_stat(struct mem_cgroup *mem,
3419 enum mem_cgroup_stat_index idx)
3421 struct mem_cgroup *iter;
3422 s64 val = 0;
3424 /* each per cpu's value can be minus.Then, use s64 */
3425 for_each_mem_cgroup_tree(iter, mem)
3426 val += mem_cgroup_read_stat(iter, idx);
3428 if (val < 0) /* race ? */
3429 val = 0;
3430 return val;
3433 static inline u64 mem_cgroup_usage(struct mem_cgroup *mem, bool swap)
3435 u64 val;
3437 if (!mem_cgroup_is_root(mem)) {
3438 if (!swap)
3439 return res_counter_read_u64(&mem->res, RES_USAGE);
3440 else
3441 return res_counter_read_u64(&mem->memsw, RES_USAGE);
3444 val = mem_cgroup_get_recursive_idx_stat(mem, MEM_CGROUP_STAT_CACHE);
3445 val += mem_cgroup_get_recursive_idx_stat(mem, MEM_CGROUP_STAT_RSS);
3447 if (swap)
3448 val += mem_cgroup_get_recursive_idx_stat(mem,
3449 MEM_CGROUP_STAT_SWAPOUT);
3451 return val << PAGE_SHIFT;
3454 static u64 mem_cgroup_read(struct cgroup *cont, struct cftype *cft)
3456 struct mem_cgroup *mem = mem_cgroup_from_cont(cont);
3457 u64 val;
3458 int type, name;
3460 type = MEMFILE_TYPE(cft->private);
3461 name = MEMFILE_ATTR(cft->private);
3462 switch (type) {
3463 case _MEM:
3464 if (name == RES_USAGE)
3465 val = mem_cgroup_usage(mem, false);
3466 else
3467 val = res_counter_read_u64(&mem->res, name);
3468 break;
3469 case _MEMSWAP:
3470 if (name == RES_USAGE)
3471 val = mem_cgroup_usage(mem, true);
3472 else
3473 val = res_counter_read_u64(&mem->memsw, name);
3474 break;
3475 default:
3476 BUG();
3477 break;
3479 return val;
3482 * The user of this function is...
3483 * RES_LIMIT.
3485 static int mem_cgroup_write(struct cgroup *cont, struct cftype *cft,
3486 const char *buffer)
3488 struct mem_cgroup *memcg = mem_cgroup_from_cont(cont);
3489 int type, name;
3490 unsigned long long val;
3491 int ret;
3493 type = MEMFILE_TYPE(cft->private);
3494 name = MEMFILE_ATTR(cft->private);
3495 switch (name) {
3496 case RES_LIMIT:
3497 if (mem_cgroup_is_root(memcg)) { /* Can't set limit on root */
3498 ret = -EINVAL;
3499 break;
3501 /* This function does all necessary parse...reuse it */
3502 ret = res_counter_memparse_write_strategy(buffer, &val);
3503 if (ret)
3504 break;
3505 if (type == _MEM)
3506 ret = mem_cgroup_resize_limit(memcg, val);
3507 else
3508 ret = mem_cgroup_resize_memsw_limit(memcg, val);
3509 break;
3510 case RES_SOFT_LIMIT:
3511 ret = res_counter_memparse_write_strategy(buffer, &val);
3512 if (ret)
3513 break;
3515 * For memsw, soft limits are hard to implement in terms
3516 * of semantics, for now, we support soft limits for
3517 * control without swap
3519 if (type == _MEM)
3520 ret = res_counter_set_soft_limit(&memcg->res, val);
3521 else
3522 ret = -EINVAL;
3523 break;
3524 default:
3525 ret = -EINVAL; /* should be BUG() ? */
3526 break;
3528 return ret;
3531 static void memcg_get_hierarchical_limit(struct mem_cgroup *memcg,
3532 unsigned long long *mem_limit, unsigned long long *memsw_limit)
3534 struct cgroup *cgroup;
3535 unsigned long long min_limit, min_memsw_limit, tmp;
3537 min_limit = res_counter_read_u64(&memcg->res, RES_LIMIT);
3538 min_memsw_limit = res_counter_read_u64(&memcg->memsw, RES_LIMIT);
3539 cgroup = memcg->css.cgroup;
3540 if (!memcg->use_hierarchy)
3541 goto out;
3543 while (cgroup->parent) {
3544 cgroup = cgroup->parent;
3545 memcg = mem_cgroup_from_cont(cgroup);
3546 if (!memcg->use_hierarchy)
3547 break;
3548 tmp = res_counter_read_u64(&memcg->res, RES_LIMIT);
3549 min_limit = min(min_limit, tmp);
3550 tmp = res_counter_read_u64(&memcg->memsw, RES_LIMIT);
3551 min_memsw_limit = min(min_memsw_limit, tmp);
3553 out:
3554 *mem_limit = min_limit;
3555 *memsw_limit = min_memsw_limit;
3556 return;
3559 static int mem_cgroup_reset(struct cgroup *cont, unsigned int event)
3561 struct mem_cgroup *mem;
3562 int type, name;
3564 mem = mem_cgroup_from_cont(cont);
3565 type = MEMFILE_TYPE(event);
3566 name = MEMFILE_ATTR(event);
3567 switch (name) {
3568 case RES_MAX_USAGE:
3569 if (type == _MEM)
3570 res_counter_reset_max(&mem->res);
3571 else
3572 res_counter_reset_max(&mem->memsw);
3573 break;
3574 case RES_FAILCNT:
3575 if (type == _MEM)
3576 res_counter_reset_failcnt(&mem->res);
3577 else
3578 res_counter_reset_failcnt(&mem->memsw);
3579 break;
3582 return 0;
3585 static u64 mem_cgroup_move_charge_read(struct cgroup *cgrp,
3586 struct cftype *cft)
3588 return mem_cgroup_from_cont(cgrp)->move_charge_at_immigrate;
3591 #ifdef CONFIG_MMU
3592 static int mem_cgroup_move_charge_write(struct cgroup *cgrp,
3593 struct cftype *cft, u64 val)
3595 struct mem_cgroup *mem = mem_cgroup_from_cont(cgrp);
3597 if (val >= (1 << NR_MOVE_TYPE))
3598 return -EINVAL;
3600 * We check this value several times in both in can_attach() and
3601 * attach(), so we need cgroup lock to prevent this value from being
3602 * inconsistent.
3604 cgroup_lock();
3605 mem->move_charge_at_immigrate = val;
3606 cgroup_unlock();
3608 return 0;
3610 #else
3611 static int mem_cgroup_move_charge_write(struct cgroup *cgrp,
3612 struct cftype *cft, u64 val)
3614 return -ENOSYS;
3616 #endif
3619 /* For read statistics */
3620 enum {
3621 MCS_CACHE,
3622 MCS_RSS,
3623 MCS_FILE_MAPPED,
3624 MCS_PGPGIN,
3625 MCS_PGPGOUT,
3626 MCS_SWAP,
3627 MCS_INACTIVE_ANON,
3628 MCS_ACTIVE_ANON,
3629 MCS_INACTIVE_FILE,
3630 MCS_ACTIVE_FILE,
3631 MCS_UNEVICTABLE,
3632 NR_MCS_STAT,
3635 struct mcs_total_stat {
3636 s64 stat[NR_MCS_STAT];
3639 struct {
3640 char *local_name;
3641 char *total_name;
3642 } memcg_stat_strings[NR_MCS_STAT] = {
3643 {"cache", "total_cache"},
3644 {"rss", "total_rss"},
3645 {"mapped_file", "total_mapped_file"},
3646 {"pgpgin", "total_pgpgin"},
3647 {"pgpgout", "total_pgpgout"},
3648 {"swap", "total_swap"},
3649 {"inactive_anon", "total_inactive_anon"},
3650 {"active_anon", "total_active_anon"},
3651 {"inactive_file", "total_inactive_file"},
3652 {"active_file", "total_active_file"},
3653 {"unevictable", "total_unevictable"}
3657 static void
3658 mem_cgroup_get_local_stat(struct mem_cgroup *mem, struct mcs_total_stat *s)
3660 s64 val;
3662 /* per cpu stat */
3663 val = mem_cgroup_read_stat(mem, MEM_CGROUP_STAT_CACHE);
3664 s->stat[MCS_CACHE] += val * PAGE_SIZE;
3665 val = mem_cgroup_read_stat(mem, MEM_CGROUP_STAT_RSS);
3666 s->stat[MCS_RSS] += val * PAGE_SIZE;
3667 val = mem_cgroup_read_stat(mem, MEM_CGROUP_STAT_FILE_MAPPED);
3668 s->stat[MCS_FILE_MAPPED] += val * PAGE_SIZE;
3669 val = mem_cgroup_read_stat(mem, MEM_CGROUP_STAT_PGPGIN_COUNT);
3670 s->stat[MCS_PGPGIN] += val;
3671 val = mem_cgroup_read_stat(mem, MEM_CGROUP_STAT_PGPGOUT_COUNT);
3672 s->stat[MCS_PGPGOUT] += val;
3673 if (do_swap_account) {
3674 val = mem_cgroup_read_stat(mem, MEM_CGROUP_STAT_SWAPOUT);
3675 s->stat[MCS_SWAP] += val * PAGE_SIZE;
3678 /* per zone stat */
3679 val = mem_cgroup_get_local_zonestat(mem, LRU_INACTIVE_ANON);
3680 s->stat[MCS_INACTIVE_ANON] += val * PAGE_SIZE;
3681 val = mem_cgroup_get_local_zonestat(mem, LRU_ACTIVE_ANON);
3682 s->stat[MCS_ACTIVE_ANON] += val * PAGE_SIZE;
3683 val = mem_cgroup_get_local_zonestat(mem, LRU_INACTIVE_FILE);
3684 s->stat[MCS_INACTIVE_FILE] += val * PAGE_SIZE;
3685 val = mem_cgroup_get_local_zonestat(mem, LRU_ACTIVE_FILE);
3686 s->stat[MCS_ACTIVE_FILE] += val * PAGE_SIZE;
3687 val = mem_cgroup_get_local_zonestat(mem, LRU_UNEVICTABLE);
3688 s->stat[MCS_UNEVICTABLE] += val * PAGE_SIZE;
3691 static void
3692 mem_cgroup_get_total_stat(struct mem_cgroup *mem, struct mcs_total_stat *s)
3694 struct mem_cgroup *iter;
3696 for_each_mem_cgroup_tree(iter, mem)
3697 mem_cgroup_get_local_stat(iter, s);
3700 static int mem_control_stat_show(struct cgroup *cont, struct cftype *cft,
3701 struct cgroup_map_cb *cb)
3703 struct mem_cgroup *mem_cont = mem_cgroup_from_cont(cont);
3704 struct mcs_total_stat mystat;
3705 int i;
3707 memset(&mystat, 0, sizeof(mystat));
3708 mem_cgroup_get_local_stat(mem_cont, &mystat);
3710 for (i = 0; i < NR_MCS_STAT; i++) {
3711 if (i == MCS_SWAP && !do_swap_account)
3712 continue;
3713 cb->fill(cb, memcg_stat_strings[i].local_name, mystat.stat[i]);
3716 /* Hierarchical information */
3718 unsigned long long limit, memsw_limit;
3719 memcg_get_hierarchical_limit(mem_cont, &limit, &memsw_limit);
3720 cb->fill(cb, "hierarchical_memory_limit", limit);
3721 if (do_swap_account)
3722 cb->fill(cb, "hierarchical_memsw_limit", memsw_limit);
3725 memset(&mystat, 0, sizeof(mystat));
3726 mem_cgroup_get_total_stat(mem_cont, &mystat);
3727 for (i = 0; i < NR_MCS_STAT; i++) {
3728 if (i == MCS_SWAP && !do_swap_account)
3729 continue;
3730 cb->fill(cb, memcg_stat_strings[i].total_name, mystat.stat[i]);
3733 #ifdef CONFIG_DEBUG_VM
3734 cb->fill(cb, "inactive_ratio", calc_inactive_ratio(mem_cont, NULL));
3737 int nid, zid;
3738 struct mem_cgroup_per_zone *mz;
3739 unsigned long recent_rotated[2] = {0, 0};
3740 unsigned long recent_scanned[2] = {0, 0};
3742 for_each_online_node(nid)
3743 for (zid = 0; zid < MAX_NR_ZONES; zid++) {
3744 mz = mem_cgroup_zoneinfo(mem_cont, nid, zid);
3746 recent_rotated[0] +=
3747 mz->reclaim_stat.recent_rotated[0];
3748 recent_rotated[1] +=
3749 mz->reclaim_stat.recent_rotated[1];
3750 recent_scanned[0] +=
3751 mz->reclaim_stat.recent_scanned[0];
3752 recent_scanned[1] +=
3753 mz->reclaim_stat.recent_scanned[1];
3755 cb->fill(cb, "recent_rotated_anon", recent_rotated[0]);
3756 cb->fill(cb, "recent_rotated_file", recent_rotated[1]);
3757 cb->fill(cb, "recent_scanned_anon", recent_scanned[0]);
3758 cb->fill(cb, "recent_scanned_file", recent_scanned[1]);
3760 #endif
3762 return 0;
3765 static u64 mem_cgroup_swappiness_read(struct cgroup *cgrp, struct cftype *cft)
3767 struct mem_cgroup *memcg = mem_cgroup_from_cont(cgrp);
3769 return get_swappiness(memcg);
3772 static int mem_cgroup_swappiness_write(struct cgroup *cgrp, struct cftype *cft,
3773 u64 val)
3775 struct mem_cgroup *memcg = mem_cgroup_from_cont(cgrp);
3776 struct mem_cgroup *parent;
3778 if (val > 100)
3779 return -EINVAL;
3781 if (cgrp->parent == NULL)
3782 return -EINVAL;
3784 parent = mem_cgroup_from_cont(cgrp->parent);
3786 cgroup_lock();
3788 /* If under hierarchy, only empty-root can set this value */
3789 if ((parent->use_hierarchy) ||
3790 (memcg->use_hierarchy && !list_empty(&cgrp->children))) {
3791 cgroup_unlock();
3792 return -EINVAL;
3795 spin_lock(&memcg->reclaim_param_lock);
3796 memcg->swappiness = val;
3797 spin_unlock(&memcg->reclaim_param_lock);
3799 cgroup_unlock();
3801 return 0;
3804 static void __mem_cgroup_threshold(struct mem_cgroup *memcg, bool swap)
3806 struct mem_cgroup_threshold_ary *t;
3807 u64 usage;
3808 int i;
3810 rcu_read_lock();
3811 if (!swap)
3812 t = rcu_dereference(memcg->thresholds.primary);
3813 else
3814 t = rcu_dereference(memcg->memsw_thresholds.primary);
3816 if (!t)
3817 goto unlock;
3819 usage = mem_cgroup_usage(memcg, swap);
3822 * current_threshold points to threshold just below usage.
3823 * If it's not true, a threshold was crossed after last
3824 * call of __mem_cgroup_threshold().
3826 i = t->current_threshold;
3829 * Iterate backward over array of thresholds starting from
3830 * current_threshold and check if a threshold is crossed.
3831 * If none of thresholds below usage is crossed, we read
3832 * only one element of the array here.
3834 for (; i >= 0 && unlikely(t->entries[i].threshold > usage); i--)
3835 eventfd_signal(t->entries[i].eventfd, 1);
3837 /* i = current_threshold + 1 */
3838 i++;
3841 * Iterate forward over array of thresholds starting from
3842 * current_threshold+1 and check if a threshold is crossed.
3843 * If none of thresholds above usage is crossed, we read
3844 * only one element of the array here.
3846 for (; i < t->size && unlikely(t->entries[i].threshold <= usage); i++)
3847 eventfd_signal(t->entries[i].eventfd, 1);
3849 /* Update current_threshold */
3850 t->current_threshold = i - 1;
3851 unlock:
3852 rcu_read_unlock();
3855 static void mem_cgroup_threshold(struct mem_cgroup *memcg)
3857 while (memcg) {
3858 __mem_cgroup_threshold(memcg, false);
3859 if (do_swap_account)
3860 __mem_cgroup_threshold(memcg, true);
3862 memcg = parent_mem_cgroup(memcg);
3866 static int compare_thresholds(const void *a, const void *b)
3868 const struct mem_cgroup_threshold *_a = a;
3869 const struct mem_cgroup_threshold *_b = b;
3871 return _a->threshold - _b->threshold;
3874 static int mem_cgroup_oom_notify_cb(struct mem_cgroup *mem)
3876 struct mem_cgroup_eventfd_list *ev;
3878 list_for_each_entry(ev, &mem->oom_notify, list)
3879 eventfd_signal(ev->eventfd, 1);
3880 return 0;
3883 static void mem_cgroup_oom_notify(struct mem_cgroup *mem)
3885 struct mem_cgroup *iter;
3887 for_each_mem_cgroup_tree(iter, mem)
3888 mem_cgroup_oom_notify_cb(iter);
3891 static int mem_cgroup_usage_register_event(struct cgroup *cgrp,
3892 struct cftype *cft, struct eventfd_ctx *eventfd, const char *args)
3894 struct mem_cgroup *memcg = mem_cgroup_from_cont(cgrp);
3895 struct mem_cgroup_thresholds *thresholds;
3896 struct mem_cgroup_threshold_ary *new;
3897 int type = MEMFILE_TYPE(cft->private);
3898 u64 threshold, usage;
3899 int i, size, ret;
3901 ret = res_counter_memparse_write_strategy(args, &threshold);
3902 if (ret)
3903 return ret;
3905 mutex_lock(&memcg->thresholds_lock);
3907 if (type == _MEM)
3908 thresholds = &memcg->thresholds;
3909 else if (type == _MEMSWAP)
3910 thresholds = &memcg->memsw_thresholds;
3911 else
3912 BUG();
3914 usage = mem_cgroup_usage(memcg, type == _MEMSWAP);
3916 /* Check if a threshold crossed before adding a new one */
3917 if (thresholds->primary)
3918 __mem_cgroup_threshold(memcg, type == _MEMSWAP);
3920 size = thresholds->primary ? thresholds->primary->size + 1 : 1;
3922 /* Allocate memory for new array of thresholds */
3923 new = kmalloc(sizeof(*new) + size * sizeof(struct mem_cgroup_threshold),
3924 GFP_KERNEL);
3925 if (!new) {
3926 ret = -ENOMEM;
3927 goto unlock;
3929 new->size = size;
3931 /* Copy thresholds (if any) to new array */
3932 if (thresholds->primary) {
3933 memcpy(new->entries, thresholds->primary->entries, (size - 1) *
3934 sizeof(struct mem_cgroup_threshold));
3937 /* Add new threshold */
3938 new->entries[size - 1].eventfd = eventfd;
3939 new->entries[size - 1].threshold = threshold;
3941 /* Sort thresholds. Registering of new threshold isn't time-critical */
3942 sort(new->entries, size, sizeof(struct mem_cgroup_threshold),
3943 compare_thresholds, NULL);
3945 /* Find current threshold */
3946 new->current_threshold = -1;
3947 for (i = 0; i < size; i++) {
3948 if (new->entries[i].threshold < usage) {
3950 * new->current_threshold will not be used until
3951 * rcu_assign_pointer(), so it's safe to increment
3952 * it here.
3954 ++new->current_threshold;
3958 /* Free old spare buffer and save old primary buffer as spare */
3959 kfree(thresholds->spare);
3960 thresholds->spare = thresholds->primary;
3962 rcu_assign_pointer(thresholds->primary, new);
3964 /* To be sure that nobody uses thresholds */
3965 synchronize_rcu();
3967 unlock:
3968 mutex_unlock(&memcg->thresholds_lock);
3970 return ret;
3973 static void mem_cgroup_usage_unregister_event(struct cgroup *cgrp,
3974 struct cftype *cft, struct eventfd_ctx *eventfd)
3976 struct mem_cgroup *memcg = mem_cgroup_from_cont(cgrp);
3977 struct mem_cgroup_thresholds *thresholds;
3978 struct mem_cgroup_threshold_ary *new;
3979 int type = MEMFILE_TYPE(cft->private);
3980 u64 usage;
3981 int i, j, size;
3983 mutex_lock(&memcg->thresholds_lock);
3984 if (type == _MEM)
3985 thresholds = &memcg->thresholds;
3986 else if (type == _MEMSWAP)
3987 thresholds = &memcg->memsw_thresholds;
3988 else
3989 BUG();
3992 * Something went wrong if we trying to unregister a threshold
3993 * if we don't have thresholds
3995 BUG_ON(!thresholds);
3997 usage = mem_cgroup_usage(memcg, type == _MEMSWAP);
3999 /* Check if a threshold crossed before removing */
4000 __mem_cgroup_threshold(memcg, type == _MEMSWAP);
4002 /* Calculate new number of threshold */
4003 size = 0;
4004 for (i = 0; i < thresholds->primary->size; i++) {
4005 if (thresholds->primary->entries[i].eventfd != eventfd)
4006 size++;
4009 new = thresholds->spare;
4011 /* Set thresholds array to NULL if we don't have thresholds */
4012 if (!size) {
4013 kfree(new);
4014 new = NULL;
4015 goto swap_buffers;
4018 new->size = size;
4020 /* Copy thresholds and find current threshold */
4021 new->current_threshold = -1;
4022 for (i = 0, j = 0; i < thresholds->primary->size; i++) {
4023 if (thresholds->primary->entries[i].eventfd == eventfd)
4024 continue;
4026 new->entries[j] = thresholds->primary->entries[i];
4027 if (new->entries[j].threshold < usage) {
4029 * new->current_threshold will not be used
4030 * until rcu_assign_pointer(), so it's safe to increment
4031 * it here.
4033 ++new->current_threshold;
4035 j++;
4038 swap_buffers:
4039 /* Swap primary and spare array */
4040 thresholds->spare = thresholds->primary;
4041 rcu_assign_pointer(thresholds->primary, new);
4043 /* To be sure that nobody uses thresholds */
4044 synchronize_rcu();
4046 mutex_unlock(&memcg->thresholds_lock);
4049 static int mem_cgroup_oom_register_event(struct cgroup *cgrp,
4050 struct cftype *cft, struct eventfd_ctx *eventfd, const char *args)
4052 struct mem_cgroup *memcg = mem_cgroup_from_cont(cgrp);
4053 struct mem_cgroup_eventfd_list *event;
4054 int type = MEMFILE_TYPE(cft->private);
4056 BUG_ON(type != _OOM_TYPE);
4057 event = kmalloc(sizeof(*event), GFP_KERNEL);
4058 if (!event)
4059 return -ENOMEM;
4061 mutex_lock(&memcg_oom_mutex);
4063 event->eventfd = eventfd;
4064 list_add(&event->list, &memcg->oom_notify);
4066 /* already in OOM ? */
4067 if (atomic_read(&memcg->oom_lock))
4068 eventfd_signal(eventfd, 1);
4069 mutex_unlock(&memcg_oom_mutex);
4071 return 0;
4074 static void mem_cgroup_oom_unregister_event(struct cgroup *cgrp,
4075 struct cftype *cft, struct eventfd_ctx *eventfd)
4077 struct mem_cgroup *mem = mem_cgroup_from_cont(cgrp);
4078 struct mem_cgroup_eventfd_list *ev, *tmp;
4079 int type = MEMFILE_TYPE(cft->private);
4081 BUG_ON(type != _OOM_TYPE);
4083 mutex_lock(&memcg_oom_mutex);
4085 list_for_each_entry_safe(ev, tmp, &mem->oom_notify, list) {
4086 if (ev->eventfd == eventfd) {
4087 list_del(&ev->list);
4088 kfree(ev);
4092 mutex_unlock(&memcg_oom_mutex);
4095 static int mem_cgroup_oom_control_read(struct cgroup *cgrp,
4096 struct cftype *cft, struct cgroup_map_cb *cb)
4098 struct mem_cgroup *mem = mem_cgroup_from_cont(cgrp);
4100 cb->fill(cb, "oom_kill_disable", mem->oom_kill_disable);
4102 if (atomic_read(&mem->oom_lock))
4103 cb->fill(cb, "under_oom", 1);
4104 else
4105 cb->fill(cb, "under_oom", 0);
4106 return 0;
4109 static int mem_cgroup_oom_control_write(struct cgroup *cgrp,
4110 struct cftype *cft, u64 val)
4112 struct mem_cgroup *mem = mem_cgroup_from_cont(cgrp);
4113 struct mem_cgroup *parent;
4115 /* cannot set to root cgroup and only 0 and 1 are allowed */
4116 if (!cgrp->parent || !((val == 0) || (val == 1)))
4117 return -EINVAL;
4119 parent = mem_cgroup_from_cont(cgrp->parent);
4121 cgroup_lock();
4122 /* oom-kill-disable is a flag for subhierarchy. */
4123 if ((parent->use_hierarchy) ||
4124 (mem->use_hierarchy && !list_empty(&cgrp->children))) {
4125 cgroup_unlock();
4126 return -EINVAL;
4128 mem->oom_kill_disable = val;
4129 if (!val)
4130 memcg_oom_recover(mem);
4131 cgroup_unlock();
4132 return 0;
4135 static struct cftype mem_cgroup_files[] = {
4137 .name = "usage_in_bytes",
4138 .private = MEMFILE_PRIVATE(_MEM, RES_USAGE),
4139 .read_u64 = mem_cgroup_read,
4140 .register_event = mem_cgroup_usage_register_event,
4141 .unregister_event = mem_cgroup_usage_unregister_event,
4144 .name = "max_usage_in_bytes",
4145 .private = MEMFILE_PRIVATE(_MEM, RES_MAX_USAGE),
4146 .trigger = mem_cgroup_reset,
4147 .read_u64 = mem_cgroup_read,
4150 .name = "limit_in_bytes",
4151 .private = MEMFILE_PRIVATE(_MEM, RES_LIMIT),
4152 .write_string = mem_cgroup_write,
4153 .read_u64 = mem_cgroup_read,
4156 .name = "soft_limit_in_bytes",
4157 .private = MEMFILE_PRIVATE(_MEM, RES_SOFT_LIMIT),
4158 .write_string = mem_cgroup_write,
4159 .read_u64 = mem_cgroup_read,
4162 .name = "failcnt",
4163 .private = MEMFILE_PRIVATE(_MEM, RES_FAILCNT),
4164 .trigger = mem_cgroup_reset,
4165 .read_u64 = mem_cgroup_read,
4168 .name = "stat",
4169 .read_map = mem_control_stat_show,
4172 .name = "force_empty",
4173 .trigger = mem_cgroup_force_empty_write,
4176 .name = "use_hierarchy",
4177 .write_u64 = mem_cgroup_hierarchy_write,
4178 .read_u64 = mem_cgroup_hierarchy_read,
4181 .name = "swappiness",
4182 .read_u64 = mem_cgroup_swappiness_read,
4183 .write_u64 = mem_cgroup_swappiness_write,
4186 .name = "move_charge_at_immigrate",
4187 .read_u64 = mem_cgroup_move_charge_read,
4188 .write_u64 = mem_cgroup_move_charge_write,
4191 .name = "oom_control",
4192 .read_map = mem_cgroup_oom_control_read,
4193 .write_u64 = mem_cgroup_oom_control_write,
4194 .register_event = mem_cgroup_oom_register_event,
4195 .unregister_event = mem_cgroup_oom_unregister_event,
4196 .private = MEMFILE_PRIVATE(_OOM_TYPE, OOM_CONTROL),
4200 #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP
4201 static struct cftype memsw_cgroup_files[] = {
4203 .name = "memsw.usage_in_bytes",
4204 .private = MEMFILE_PRIVATE(_MEMSWAP, RES_USAGE),
4205 .read_u64 = mem_cgroup_read,
4206 .register_event = mem_cgroup_usage_register_event,
4207 .unregister_event = mem_cgroup_usage_unregister_event,
4210 .name = "memsw.max_usage_in_bytes",
4211 .private = MEMFILE_PRIVATE(_MEMSWAP, RES_MAX_USAGE),
4212 .trigger = mem_cgroup_reset,
4213 .read_u64 = mem_cgroup_read,
4216 .name = "memsw.limit_in_bytes",
4217 .private = MEMFILE_PRIVATE(_MEMSWAP, RES_LIMIT),
4218 .write_string = mem_cgroup_write,
4219 .read_u64 = mem_cgroup_read,
4222 .name = "memsw.failcnt",
4223 .private = MEMFILE_PRIVATE(_MEMSWAP, RES_FAILCNT),
4224 .trigger = mem_cgroup_reset,
4225 .read_u64 = mem_cgroup_read,
4229 static int register_memsw_files(struct cgroup *cont, struct cgroup_subsys *ss)
4231 if (!do_swap_account)
4232 return 0;
4233 return cgroup_add_files(cont, ss, memsw_cgroup_files,
4234 ARRAY_SIZE(memsw_cgroup_files));
4236 #else
4237 static int register_memsw_files(struct cgroup *cont, struct cgroup_subsys *ss)
4239 return 0;
4241 #endif
4243 static int alloc_mem_cgroup_per_zone_info(struct mem_cgroup *mem, int node)
4245 struct mem_cgroup_per_node *pn;
4246 struct mem_cgroup_per_zone *mz;
4247 enum lru_list l;
4248 int zone, tmp = node;
4250 * This routine is called against possible nodes.
4251 * But it's BUG to call kmalloc() against offline node.
4253 * TODO: this routine can waste much memory for nodes which will
4254 * never be onlined. It's better to use memory hotplug callback
4255 * function.
4257 if (!node_state(node, N_NORMAL_MEMORY))
4258 tmp = -1;
4259 pn = kzalloc_node(sizeof(*pn), GFP_KERNEL, tmp);
4260 if (!pn)
4261 return 1;
4263 mem->info.nodeinfo[node] = pn;
4264 for (zone = 0; zone < MAX_NR_ZONES; zone++) {
4265 mz = &pn->zoneinfo[zone];
4266 for_each_lru(l)
4267 INIT_LIST_HEAD(&mz->lists[l]);
4268 mz->usage_in_excess = 0;
4269 mz->on_tree = false;
4270 mz->mem = mem;
4272 return 0;
4275 static void free_mem_cgroup_per_zone_info(struct mem_cgroup *mem, int node)
4277 kfree(mem->info.nodeinfo[node]);
4280 static struct mem_cgroup *mem_cgroup_alloc(void)
4282 struct mem_cgroup *mem;
4283 int size = sizeof(struct mem_cgroup);
4285 /* Can be very big if MAX_NUMNODES is very big */
4286 if (size < PAGE_SIZE)
4287 mem = kzalloc(size, GFP_KERNEL);
4288 else
4289 mem = vzalloc(size);
4291 if (!mem)
4292 return NULL;
4294 mem->stat = alloc_percpu(struct mem_cgroup_stat_cpu);
4295 if (!mem->stat)
4296 goto out_free;
4297 spin_lock_init(&mem->pcp_counter_lock);
4298 return mem;
4300 out_free:
4301 if (size < PAGE_SIZE)
4302 kfree(mem);
4303 else
4304 vfree(mem);
4305 return NULL;
4309 * At destroying mem_cgroup, references from swap_cgroup can remain.
4310 * (scanning all at force_empty is too costly...)
4312 * Instead of clearing all references at force_empty, we remember
4313 * the number of reference from swap_cgroup and free mem_cgroup when
4314 * it goes down to 0.
4316 * Removal of cgroup itself succeeds regardless of refs from swap.
4319 static void __mem_cgroup_free(struct mem_cgroup *mem)
4321 int node;
4323 mem_cgroup_remove_from_trees(mem);
4324 free_css_id(&mem_cgroup_subsys, &mem->css);
4326 for_each_node_state(node, N_POSSIBLE)
4327 free_mem_cgroup_per_zone_info(mem, node);
4329 free_percpu(mem->stat);
4330 if (sizeof(struct mem_cgroup) < PAGE_SIZE)
4331 kfree(mem);
4332 else
4333 vfree(mem);
4336 static void mem_cgroup_get(struct mem_cgroup *mem)
4338 atomic_inc(&mem->refcnt);
4341 static void __mem_cgroup_put(struct mem_cgroup *mem, int count)
4343 if (atomic_sub_and_test(count, &mem->refcnt)) {
4344 struct mem_cgroup *parent = parent_mem_cgroup(mem);
4345 __mem_cgroup_free(mem);
4346 if (parent)
4347 mem_cgroup_put(parent);
4351 static void mem_cgroup_put(struct mem_cgroup *mem)
4353 __mem_cgroup_put(mem, 1);
4357 * Returns the parent mem_cgroup in memcgroup hierarchy with hierarchy enabled.
4359 static struct mem_cgroup *parent_mem_cgroup(struct mem_cgroup *mem)
4361 if (!mem->res.parent)
4362 return NULL;
4363 return mem_cgroup_from_res_counter(mem->res.parent, res);
4366 #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP
4367 static void __init enable_swap_cgroup(void)
4369 if (!mem_cgroup_disabled() && really_do_swap_account)
4370 do_swap_account = 1;
4372 #else
4373 static void __init enable_swap_cgroup(void)
4376 #endif
4378 static int mem_cgroup_soft_limit_tree_init(void)
4380 struct mem_cgroup_tree_per_node *rtpn;
4381 struct mem_cgroup_tree_per_zone *rtpz;
4382 int tmp, node, zone;
4384 for_each_node_state(node, N_POSSIBLE) {
4385 tmp = node;
4386 if (!node_state(node, N_NORMAL_MEMORY))
4387 tmp = -1;
4388 rtpn = kzalloc_node(sizeof(*rtpn), GFP_KERNEL, tmp);
4389 if (!rtpn)
4390 return 1;
4392 soft_limit_tree.rb_tree_per_node[node] = rtpn;
4394 for (zone = 0; zone < MAX_NR_ZONES; zone++) {
4395 rtpz = &rtpn->rb_tree_per_zone[zone];
4396 rtpz->rb_root = RB_ROOT;
4397 spin_lock_init(&rtpz->lock);
4400 return 0;
4403 static struct cgroup_subsys_state * __ref
4404 mem_cgroup_create(struct cgroup_subsys *ss, struct cgroup *cont)
4406 struct mem_cgroup *mem, *parent;
4407 long error = -ENOMEM;
4408 int node;
4410 mem = mem_cgroup_alloc();
4411 if (!mem)
4412 return ERR_PTR(error);
4414 for_each_node_state(node, N_POSSIBLE)
4415 if (alloc_mem_cgroup_per_zone_info(mem, node))
4416 goto free_out;
4418 /* root ? */
4419 if (cont->parent == NULL) {
4420 int cpu;
4421 enable_swap_cgroup();
4422 parent = NULL;
4423 root_mem_cgroup = mem;
4424 if (mem_cgroup_soft_limit_tree_init())
4425 goto free_out;
4426 for_each_possible_cpu(cpu) {
4427 struct memcg_stock_pcp *stock =
4428 &per_cpu(memcg_stock, cpu);
4429 INIT_WORK(&stock->work, drain_local_stock);
4431 hotcpu_notifier(memcg_cpu_hotplug_callback, 0);
4432 } else {
4433 parent = mem_cgroup_from_cont(cont->parent);
4434 mem->use_hierarchy = parent->use_hierarchy;
4435 mem->oom_kill_disable = parent->oom_kill_disable;
4438 if (parent && parent->use_hierarchy) {
4439 res_counter_init(&mem->res, &parent->res);
4440 res_counter_init(&mem->memsw, &parent->memsw);
4442 * We increment refcnt of the parent to ensure that we can
4443 * safely access it on res_counter_charge/uncharge.
4444 * This refcnt will be decremented when freeing this
4445 * mem_cgroup(see mem_cgroup_put).
4447 mem_cgroup_get(parent);
4448 } else {
4449 res_counter_init(&mem->res, NULL);
4450 res_counter_init(&mem->memsw, NULL);
4452 mem->last_scanned_child = 0;
4453 spin_lock_init(&mem->reclaim_param_lock);
4454 INIT_LIST_HEAD(&mem->oom_notify);
4456 if (parent)
4457 mem->swappiness = get_swappiness(parent);
4458 atomic_set(&mem->refcnt, 1);
4459 mem->move_charge_at_immigrate = 0;
4460 mutex_init(&mem->thresholds_lock);
4461 return &mem->css;
4462 free_out:
4463 __mem_cgroup_free(mem);
4464 root_mem_cgroup = NULL;
4465 return ERR_PTR(error);
4468 static int mem_cgroup_pre_destroy(struct cgroup_subsys *ss,
4469 struct cgroup *cont)
4471 struct mem_cgroup *mem = mem_cgroup_from_cont(cont);
4473 return mem_cgroup_force_empty(mem, false);
4476 static void mem_cgroup_destroy(struct cgroup_subsys *ss,
4477 struct cgroup *cont)
4479 struct mem_cgroup *mem = mem_cgroup_from_cont(cont);
4481 mem_cgroup_put(mem);
4484 static int mem_cgroup_populate(struct cgroup_subsys *ss,
4485 struct cgroup *cont)
4487 int ret;
4489 ret = cgroup_add_files(cont, ss, mem_cgroup_files,
4490 ARRAY_SIZE(mem_cgroup_files));
4492 if (!ret)
4493 ret = register_memsw_files(cont, ss);
4494 return ret;
4497 #ifdef CONFIG_MMU
4498 /* Handlers for move charge at task migration. */
4499 #define PRECHARGE_COUNT_AT_ONCE 256
4500 static int mem_cgroup_do_precharge(unsigned long count)
4502 int ret = 0;
4503 int batch_count = PRECHARGE_COUNT_AT_ONCE;
4504 struct mem_cgroup *mem = mc.to;
4506 if (mem_cgroup_is_root(mem)) {
4507 mc.precharge += count;
4508 /* we don't need css_get for root */
4509 return ret;
4511 /* try to charge at once */
4512 if (count > 1) {
4513 struct res_counter *dummy;
4515 * "mem" cannot be under rmdir() because we've already checked
4516 * by cgroup_lock_live_cgroup() that it is not removed and we
4517 * are still under the same cgroup_mutex. So we can postpone
4518 * css_get().
4520 if (res_counter_charge(&mem->res, PAGE_SIZE * count, &dummy))
4521 goto one_by_one;
4522 if (do_swap_account && res_counter_charge(&mem->memsw,
4523 PAGE_SIZE * count, &dummy)) {
4524 res_counter_uncharge(&mem->res, PAGE_SIZE * count);
4525 goto one_by_one;
4527 mc.precharge += count;
4528 return ret;
4530 one_by_one:
4531 /* fall back to one by one charge */
4532 while (count--) {
4533 if (signal_pending(current)) {
4534 ret = -EINTR;
4535 break;
4537 if (!batch_count--) {
4538 batch_count = PRECHARGE_COUNT_AT_ONCE;
4539 cond_resched();
4541 ret = __mem_cgroup_try_charge(NULL, GFP_KERNEL, &mem, false,
4542 PAGE_SIZE);
4543 if (ret || !mem)
4544 /* mem_cgroup_clear_mc() will do uncharge later */
4545 return -ENOMEM;
4546 mc.precharge++;
4548 return ret;
4552 * is_target_pte_for_mc - check a pte whether it is valid for move charge
4553 * @vma: the vma the pte to be checked belongs
4554 * @addr: the address corresponding to the pte to be checked
4555 * @ptent: the pte to be checked
4556 * @target: the pointer the target page or swap ent will be stored(can be NULL)
4558 * Returns
4559 * 0(MC_TARGET_NONE): if the pte is not a target for move charge.
4560 * 1(MC_TARGET_PAGE): if the page corresponding to this pte is a target for
4561 * move charge. if @target is not NULL, the page is stored in target->page
4562 * with extra refcnt got(Callers should handle it).
4563 * 2(MC_TARGET_SWAP): if the swap entry corresponding to this pte is a
4564 * target for charge migration. if @target is not NULL, the entry is stored
4565 * in target->ent.
4567 * Called with pte lock held.
4569 union mc_target {
4570 struct page *page;
4571 swp_entry_t ent;
4574 enum mc_target_type {
4575 MC_TARGET_NONE, /* not used */
4576 MC_TARGET_PAGE,
4577 MC_TARGET_SWAP,
4580 static struct page *mc_handle_present_pte(struct vm_area_struct *vma,
4581 unsigned long addr, pte_t ptent)
4583 struct page *page = vm_normal_page(vma, addr, ptent);
4585 if (!page || !page_mapped(page))
4586 return NULL;
4587 if (PageAnon(page)) {
4588 /* we don't move shared anon */
4589 if (!move_anon() || page_mapcount(page) > 2)
4590 return NULL;
4591 } else if (!move_file())
4592 /* we ignore mapcount for file pages */
4593 return NULL;
4594 if (!get_page_unless_zero(page))
4595 return NULL;
4597 return page;
4600 static struct page *mc_handle_swap_pte(struct vm_area_struct *vma,
4601 unsigned long addr, pte_t ptent, swp_entry_t *entry)
4603 int usage_count;
4604 struct page *page = NULL;
4605 swp_entry_t ent = pte_to_swp_entry(ptent);
4607 if (!move_anon() || non_swap_entry(ent))
4608 return NULL;
4609 usage_count = mem_cgroup_count_swap_user(ent, &page);
4610 if (usage_count > 1) { /* we don't move shared anon */
4611 if (page)
4612 put_page(page);
4613 return NULL;
4615 if (do_swap_account)
4616 entry->val = ent.val;
4618 return page;
4621 static struct page *mc_handle_file_pte(struct vm_area_struct *vma,
4622 unsigned long addr, pte_t ptent, swp_entry_t *entry)
4624 struct page *page = NULL;
4625 struct inode *inode;
4626 struct address_space *mapping;
4627 pgoff_t pgoff;
4629 if (!vma->vm_file) /* anonymous vma */
4630 return NULL;
4631 if (!move_file())
4632 return NULL;
4634 inode = vma->vm_file->f_path.dentry->d_inode;
4635 mapping = vma->vm_file->f_mapping;
4636 if (pte_none(ptent))
4637 pgoff = linear_page_index(vma, addr);
4638 else /* pte_file(ptent) is true */
4639 pgoff = pte_to_pgoff(ptent);
4641 /* page is moved even if it's not RSS of this task(page-faulted). */
4642 if (!mapping_cap_swap_backed(mapping)) { /* normal file */
4643 page = find_get_page(mapping, pgoff);
4644 } else { /* shmem/tmpfs file. we should take account of swap too. */
4645 swp_entry_t ent;
4646 mem_cgroup_get_shmem_target(inode, pgoff, &page, &ent);
4647 if (do_swap_account)
4648 entry->val = ent.val;
4651 return page;
4654 static int is_target_pte_for_mc(struct vm_area_struct *vma,
4655 unsigned long addr, pte_t ptent, union mc_target *target)
4657 struct page *page = NULL;
4658 struct page_cgroup *pc;
4659 int ret = 0;
4660 swp_entry_t ent = { .val = 0 };
4662 if (pte_present(ptent))
4663 page = mc_handle_present_pte(vma, addr, ptent);
4664 else if (is_swap_pte(ptent))
4665 page = mc_handle_swap_pte(vma, addr, ptent, &ent);
4666 else if (pte_none(ptent) || pte_file(ptent))
4667 page = mc_handle_file_pte(vma, addr, ptent, &ent);
4669 if (!page && !ent.val)
4670 return 0;
4671 if (page) {
4672 pc = lookup_page_cgroup(page);
4674 * Do only loose check w/o page_cgroup lock.
4675 * mem_cgroup_move_account() checks the pc is valid or not under
4676 * the lock.
4678 if (PageCgroupUsed(pc) && pc->mem_cgroup == mc.from) {
4679 ret = MC_TARGET_PAGE;
4680 if (target)
4681 target->page = page;
4683 if (!ret || !target)
4684 put_page(page);
4686 /* There is a swap entry and a page doesn't exist or isn't charged */
4687 if (ent.val && !ret &&
4688 css_id(&mc.from->css) == lookup_swap_cgroup(ent)) {
4689 ret = MC_TARGET_SWAP;
4690 if (target)
4691 target->ent = ent;
4693 return ret;
4696 static int mem_cgroup_count_precharge_pte_range(pmd_t *pmd,
4697 unsigned long addr, unsigned long end,
4698 struct mm_walk *walk)
4700 struct vm_area_struct *vma = walk->private;
4701 pte_t *pte;
4702 spinlock_t *ptl;
4704 VM_BUG_ON(pmd_trans_huge(*pmd));
4705 pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl);
4706 for (; addr != end; pte++, addr += PAGE_SIZE)
4707 if (is_target_pte_for_mc(vma, addr, *pte, NULL))
4708 mc.precharge++; /* increment precharge temporarily */
4709 pte_unmap_unlock(pte - 1, ptl);
4710 cond_resched();
4712 return 0;
4715 static unsigned long mem_cgroup_count_precharge(struct mm_struct *mm)
4717 unsigned long precharge;
4718 struct vm_area_struct *vma;
4720 down_read(&mm->mmap_sem);
4721 for (vma = mm->mmap; vma; vma = vma->vm_next) {
4722 struct mm_walk mem_cgroup_count_precharge_walk = {
4723 .pmd_entry = mem_cgroup_count_precharge_pte_range,
4724 .mm = mm,
4725 .private = vma,
4727 if (is_vm_hugetlb_page(vma))
4728 continue;
4729 walk_page_range(vma->vm_start, vma->vm_end,
4730 &mem_cgroup_count_precharge_walk);
4732 up_read(&mm->mmap_sem);
4734 precharge = mc.precharge;
4735 mc.precharge = 0;
4737 return precharge;
4740 static int mem_cgroup_precharge_mc(struct mm_struct *mm)
4742 unsigned long precharge = mem_cgroup_count_precharge(mm);
4744 VM_BUG_ON(mc.moving_task);
4745 mc.moving_task = current;
4746 return mem_cgroup_do_precharge(precharge);
4749 /* cancels all extra charges on mc.from and mc.to, and wakes up all waiters. */
4750 static void __mem_cgroup_clear_mc(void)
4752 struct mem_cgroup *from = mc.from;
4753 struct mem_cgroup *to = mc.to;
4755 /* we must uncharge all the leftover precharges from mc.to */
4756 if (mc.precharge) {
4757 __mem_cgroup_cancel_charge(mc.to, mc.precharge);
4758 mc.precharge = 0;
4761 * we didn't uncharge from mc.from at mem_cgroup_move_account(), so
4762 * we must uncharge here.
4764 if (mc.moved_charge) {
4765 __mem_cgroup_cancel_charge(mc.from, mc.moved_charge);
4766 mc.moved_charge = 0;
4768 /* we must fixup refcnts and charges */
4769 if (mc.moved_swap) {
4770 /* uncharge swap account from the old cgroup */
4771 if (!mem_cgroup_is_root(mc.from))
4772 res_counter_uncharge(&mc.from->memsw,
4773 PAGE_SIZE * mc.moved_swap);
4774 __mem_cgroup_put(mc.from, mc.moved_swap);
4776 if (!mem_cgroup_is_root(mc.to)) {
4778 * we charged both to->res and to->memsw, so we should
4779 * uncharge to->res.
4781 res_counter_uncharge(&mc.to->res,
4782 PAGE_SIZE * mc.moved_swap);
4784 /* we've already done mem_cgroup_get(mc.to) */
4785 mc.moved_swap = 0;
4787 memcg_oom_recover(from);
4788 memcg_oom_recover(to);
4789 wake_up_all(&mc.waitq);
4792 static void mem_cgroup_clear_mc(void)
4794 struct mem_cgroup *from = mc.from;
4797 * we must clear moving_task before waking up waiters at the end of
4798 * task migration.
4800 mc.moving_task = NULL;
4801 __mem_cgroup_clear_mc();
4802 spin_lock(&mc.lock);
4803 mc.from = NULL;
4804 mc.to = NULL;
4805 spin_unlock(&mc.lock);
4806 mem_cgroup_end_move(from);
4809 static int mem_cgroup_can_attach(struct cgroup_subsys *ss,
4810 struct cgroup *cgroup,
4811 struct task_struct *p,
4812 bool threadgroup)
4814 int ret = 0;
4815 struct mem_cgroup *mem = mem_cgroup_from_cont(cgroup);
4817 if (mem->move_charge_at_immigrate) {
4818 struct mm_struct *mm;
4819 struct mem_cgroup *from = mem_cgroup_from_task(p);
4821 VM_BUG_ON(from == mem);
4823 mm = get_task_mm(p);
4824 if (!mm)
4825 return 0;
4826 /* We move charges only when we move a owner of the mm */
4827 if (mm->owner == p) {
4828 VM_BUG_ON(mc.from);
4829 VM_BUG_ON(mc.to);
4830 VM_BUG_ON(mc.precharge);
4831 VM_BUG_ON(mc.moved_charge);
4832 VM_BUG_ON(mc.moved_swap);
4833 mem_cgroup_start_move(from);
4834 spin_lock(&mc.lock);
4835 mc.from = from;
4836 mc.to = mem;
4837 spin_unlock(&mc.lock);
4838 /* We set mc.moving_task later */
4840 ret = mem_cgroup_precharge_mc(mm);
4841 if (ret)
4842 mem_cgroup_clear_mc();
4844 mmput(mm);
4846 return ret;
4849 static void mem_cgroup_cancel_attach(struct cgroup_subsys *ss,
4850 struct cgroup *cgroup,
4851 struct task_struct *p,
4852 bool threadgroup)
4854 mem_cgroup_clear_mc();
4857 static int mem_cgroup_move_charge_pte_range(pmd_t *pmd,
4858 unsigned long addr, unsigned long end,
4859 struct mm_walk *walk)
4861 int ret = 0;
4862 struct vm_area_struct *vma = walk->private;
4863 pte_t *pte;
4864 spinlock_t *ptl;
4866 retry:
4867 VM_BUG_ON(pmd_trans_huge(*pmd));
4868 pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl);
4869 for (; addr != end; addr += PAGE_SIZE) {
4870 pte_t ptent = *(pte++);
4871 union mc_target target;
4872 int type;
4873 struct page *page;
4874 struct page_cgroup *pc;
4875 swp_entry_t ent;
4877 if (!mc.precharge)
4878 break;
4880 type = is_target_pte_for_mc(vma, addr, ptent, &target);
4881 switch (type) {
4882 case MC_TARGET_PAGE:
4883 page = target.page;
4884 if (isolate_lru_page(page))
4885 goto put;
4886 pc = lookup_page_cgroup(page);
4887 if (!mem_cgroup_move_account(pc,
4888 mc.from, mc.to, false, PAGE_SIZE)) {
4889 mc.precharge--;
4890 /* we uncharge from mc.from later. */
4891 mc.moved_charge++;
4893 putback_lru_page(page);
4894 put: /* is_target_pte_for_mc() gets the page */
4895 put_page(page);
4896 break;
4897 case MC_TARGET_SWAP:
4898 ent = target.ent;
4899 if (!mem_cgroup_move_swap_account(ent,
4900 mc.from, mc.to, false)) {
4901 mc.precharge--;
4902 /* we fixup refcnts and charges later. */
4903 mc.moved_swap++;
4905 break;
4906 default:
4907 break;
4910 pte_unmap_unlock(pte - 1, ptl);
4911 cond_resched();
4913 if (addr != end) {
4915 * We have consumed all precharges we got in can_attach().
4916 * We try charge one by one, but don't do any additional
4917 * charges to mc.to if we have failed in charge once in attach()
4918 * phase.
4920 ret = mem_cgroup_do_precharge(1);
4921 if (!ret)
4922 goto retry;
4925 return ret;
4928 static void mem_cgroup_move_charge(struct mm_struct *mm)
4930 struct vm_area_struct *vma;
4932 lru_add_drain_all();
4933 retry:
4934 if (unlikely(!down_read_trylock(&mm->mmap_sem))) {
4936 * Someone who are holding the mmap_sem might be waiting in
4937 * waitq. So we cancel all extra charges, wake up all waiters,
4938 * and retry. Because we cancel precharges, we might not be able
4939 * to move enough charges, but moving charge is a best-effort
4940 * feature anyway, so it wouldn't be a big problem.
4942 __mem_cgroup_clear_mc();
4943 cond_resched();
4944 goto retry;
4946 for (vma = mm->mmap; vma; vma = vma->vm_next) {
4947 int ret;
4948 struct mm_walk mem_cgroup_move_charge_walk = {
4949 .pmd_entry = mem_cgroup_move_charge_pte_range,
4950 .mm = mm,
4951 .private = vma,
4953 if (is_vm_hugetlb_page(vma))
4954 continue;
4955 ret = walk_page_range(vma->vm_start, vma->vm_end,
4956 &mem_cgroup_move_charge_walk);
4957 if (ret)
4959 * means we have consumed all precharges and failed in
4960 * doing additional charge. Just abandon here.
4962 break;
4964 up_read(&mm->mmap_sem);
4967 static void mem_cgroup_move_task(struct cgroup_subsys *ss,
4968 struct cgroup *cont,
4969 struct cgroup *old_cont,
4970 struct task_struct *p,
4971 bool threadgroup)
4973 struct mm_struct *mm;
4975 if (!mc.to)
4976 /* no need to move charge */
4977 return;
4979 mm = get_task_mm(p);
4980 if (mm) {
4981 mem_cgroup_move_charge(mm);
4982 mmput(mm);
4984 mem_cgroup_clear_mc();
4986 #else /* !CONFIG_MMU */
4987 static int mem_cgroup_can_attach(struct cgroup_subsys *ss,
4988 struct cgroup *cgroup,
4989 struct task_struct *p,
4990 bool threadgroup)
4992 return 0;
4994 static void mem_cgroup_cancel_attach(struct cgroup_subsys *ss,
4995 struct cgroup *cgroup,
4996 struct task_struct *p,
4997 bool threadgroup)
5000 static void mem_cgroup_move_task(struct cgroup_subsys *ss,
5001 struct cgroup *cont,
5002 struct cgroup *old_cont,
5003 struct task_struct *p,
5004 bool threadgroup)
5007 #endif
5009 struct cgroup_subsys mem_cgroup_subsys = {
5010 .name = "memory",
5011 .subsys_id = mem_cgroup_subsys_id,
5012 .create = mem_cgroup_create,
5013 .pre_destroy = mem_cgroup_pre_destroy,
5014 .destroy = mem_cgroup_destroy,
5015 .populate = mem_cgroup_populate,
5016 .can_attach = mem_cgroup_can_attach,
5017 .cancel_attach = mem_cgroup_cancel_attach,
5018 .attach = mem_cgroup_move_task,
5019 .early_init = 0,
5020 .use_id = 1,
5023 #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP
5024 static int __init enable_swap_account(char *s)
5026 /* consider enabled if no parameter or 1 is given */
5027 if (!(*s) || !strcmp(s, "=1"))
5028 really_do_swap_account = 1;
5029 else if (!strcmp(s, "=0"))
5030 really_do_swap_account = 0;
5031 return 1;
5033 __setup("swapaccount", enable_swap_account);
5035 static int __init disable_swap_account(char *s)
5037 enable_swap_account("=0");
5038 return 1;
5040 __setup("noswapaccount", disable_swap_account);
5041 #endif