1 /* memcontrol.c - Memory Controller
3 * Copyright IBM Corporation, 2007
4 * Author Balbir Singh <balbir@linux.vnet.ibm.com>
6 * Copyright 2007 OpenVZ SWsoft Inc
7 * Author: Pavel Emelianov <xemul@openvz.org>
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License as published by
11 * the Free Software Foundation; either version 2 of the License, or
12 * (at your option) any later version.
14 * This program is distributed in the hope that it will be useful,
15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 * GNU General Public License for more details.
20 #include <linux/res_counter.h>
21 #include <linux/memcontrol.h>
22 #include <linux/cgroup.h>
24 #include <linux/pagemap.h>
25 #include <linux/smp.h>
26 #include <linux/page-flags.h>
27 #include <linux/backing-dev.h>
28 #include <linux/bit_spinlock.h>
29 #include <linux/rcupdate.h>
30 #include <linux/limits.h>
31 #include <linux/mutex.h>
32 #include <linux/rbtree.h>
33 #include <linux/slab.h>
34 #include <linux/swap.h>
35 #include <linux/spinlock.h>
37 #include <linux/seq_file.h>
38 #include <linux/vmalloc.h>
39 #include <linux/mm_inline.h>
40 #include <linux/page_cgroup.h>
43 #include <asm/uaccess.h>
45 struct cgroup_subsys mem_cgroup_subsys __read_mostly;
46 #define MEM_CGROUP_RECLAIM_RETRIES 5
47 struct mem_cgroup *root_mem_cgroup __read_mostly;
49 #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP
50 /* Turned on only when memory cgroup is enabled && really_do_swap_account = 1 */
51 int do_swap_account __read_mostly;
52 static int really_do_swap_account __initdata = 1; /* for remember boot option*/
54 #define do_swap_account (0)
57 static DEFINE_MUTEX(memcg_tasklist); /* can be hold under cgroup_mutex */
58 #define SOFTLIMIT_EVENTS_THRESH (1000)
61 * Statistics for memory cgroup.
63 enum mem_cgroup_stat_index {
65 * For MEM_CONTAINER_TYPE_ALL, usage = pagecache + rss.
67 MEM_CGROUP_STAT_CACHE, /* # of pages charged as cache */
68 MEM_CGROUP_STAT_RSS, /* # of pages charged as anon rss */
69 MEM_CGROUP_STAT_MAPPED_FILE, /* # of pages charged as file rss */
70 MEM_CGROUP_STAT_PGPGIN_COUNT, /* # of pages paged in */
71 MEM_CGROUP_STAT_PGPGOUT_COUNT, /* # of pages paged out */
72 MEM_CGROUP_STAT_EVENTS, /* sum of pagein + pageout for internal use */
73 MEM_CGROUP_STAT_SWAPOUT, /* # of pages, swapped out */
75 MEM_CGROUP_STAT_NSTATS,
78 struct mem_cgroup_stat_cpu {
79 s64 count[MEM_CGROUP_STAT_NSTATS];
80 } ____cacheline_aligned_in_smp;
82 struct mem_cgroup_stat {
83 struct mem_cgroup_stat_cpu cpustat[0];
87 __mem_cgroup_stat_reset_safe(struct mem_cgroup_stat_cpu *stat,
88 enum mem_cgroup_stat_index idx)
94 __mem_cgroup_stat_read_local(struct mem_cgroup_stat_cpu *stat,
95 enum mem_cgroup_stat_index idx)
97 return stat->count[idx];
101 * For accounting under irq disable, no need for increment preempt count.
103 static inline void __mem_cgroup_stat_add_safe(struct mem_cgroup_stat_cpu *stat,
104 enum mem_cgroup_stat_index idx, int val)
106 stat->count[idx] += val;
109 static s64 mem_cgroup_read_stat(struct mem_cgroup_stat *stat,
110 enum mem_cgroup_stat_index idx)
114 for_each_possible_cpu(cpu)
115 ret += stat->cpustat[cpu].count[idx];
119 static s64 mem_cgroup_local_usage(struct mem_cgroup_stat *stat)
123 ret = mem_cgroup_read_stat(stat, MEM_CGROUP_STAT_CACHE);
124 ret += mem_cgroup_read_stat(stat, MEM_CGROUP_STAT_RSS);
129 * per-zone information in memory controller.
131 struct mem_cgroup_per_zone {
133 * spin_lock to protect the per cgroup LRU
135 struct list_head lists[NR_LRU_LISTS];
136 unsigned long count[NR_LRU_LISTS];
138 struct zone_reclaim_stat reclaim_stat;
139 struct rb_node tree_node; /* RB tree node */
140 unsigned long long usage_in_excess;/* Set to the value by which */
141 /* the soft limit is exceeded*/
143 struct mem_cgroup *mem; /* Back pointer, we cannot */
144 /* use container_of */
146 /* Macro for accessing counter */
147 #define MEM_CGROUP_ZSTAT(mz, idx) ((mz)->count[(idx)])
149 struct mem_cgroup_per_node {
150 struct mem_cgroup_per_zone zoneinfo[MAX_NR_ZONES];
153 struct mem_cgroup_lru_info {
154 struct mem_cgroup_per_node *nodeinfo[MAX_NUMNODES];
158 * Cgroups above their limits are maintained in a RB-Tree, independent of
159 * their hierarchy representation
162 struct mem_cgroup_tree_per_zone {
163 struct rb_root rb_root;
167 struct mem_cgroup_tree_per_node {
168 struct mem_cgroup_tree_per_zone rb_tree_per_zone[MAX_NR_ZONES];
171 struct mem_cgroup_tree {
172 struct mem_cgroup_tree_per_node *rb_tree_per_node[MAX_NUMNODES];
175 static struct mem_cgroup_tree soft_limit_tree __read_mostly;
178 * The memory controller data structure. The memory controller controls both
179 * page cache and RSS per cgroup. We would eventually like to provide
180 * statistics based on the statistics developed by Rik Van Riel for clock-pro,
181 * to help the administrator determine what knobs to tune.
183 * TODO: Add a water mark for the memory controller. Reclaim will begin when
184 * we hit the water mark. May be even add a low water mark, such that
185 * no reclaim occurs from a cgroup at it's low water mark, this is
186 * a feature that will be implemented much later in the future.
189 struct cgroup_subsys_state css;
191 * the counter to account for memory usage
193 struct res_counter res;
195 * the counter to account for mem+swap usage.
197 struct res_counter memsw;
199 * Per cgroup active and inactive list, similar to the
200 * per zone LRU lists.
202 struct mem_cgroup_lru_info info;
205 protect against reclaim related member.
207 spinlock_t reclaim_param_lock;
209 int prev_priority; /* for recording reclaim priority */
212 * While reclaiming in a hiearchy, we cache the last child we
215 int last_scanned_child;
217 * Should the accounting and control be hierarchical, per subtree?
220 unsigned long last_oom_jiffies;
223 unsigned int swappiness;
225 /* set when res.limit == memsw.limit */
226 bool memsw_is_minimum;
229 * statistics. This must be placed at the end of memcg.
231 struct mem_cgroup_stat stat;
235 * Maximum loops in mem_cgroup_hierarchical_reclaim(), used for soft
236 * limit reclaim to prevent infinite loops, if they ever occur.
238 #define MEM_CGROUP_MAX_RECLAIM_LOOPS (100)
239 #define MEM_CGROUP_MAX_SOFT_LIMIT_RECLAIM_LOOPS (2)
242 MEM_CGROUP_CHARGE_TYPE_CACHE = 0,
243 MEM_CGROUP_CHARGE_TYPE_MAPPED,
244 MEM_CGROUP_CHARGE_TYPE_SHMEM, /* used by page migration of shmem */
245 MEM_CGROUP_CHARGE_TYPE_FORCE, /* used by force_empty */
246 MEM_CGROUP_CHARGE_TYPE_SWAPOUT, /* for accounting swapcache */
247 MEM_CGROUP_CHARGE_TYPE_DROP, /* a page was unused swap cache */
251 /* only for here (for easy reading.) */
252 #define PCGF_CACHE (1UL << PCG_CACHE)
253 #define PCGF_USED (1UL << PCG_USED)
254 #define PCGF_LOCK (1UL << PCG_LOCK)
255 /* Not used, but added here for completeness */
256 #define PCGF_ACCT (1UL << PCG_ACCT)
258 /* for encoding cft->private value on file */
261 #define MEMFILE_PRIVATE(x, val) (((x) << 16) | (val))
262 #define MEMFILE_TYPE(val) (((val) >> 16) & 0xffff)
263 #define MEMFILE_ATTR(val) ((val) & 0xffff)
266 * Reclaim flags for mem_cgroup_hierarchical_reclaim
268 #define MEM_CGROUP_RECLAIM_NOSWAP_BIT 0x0
269 #define MEM_CGROUP_RECLAIM_NOSWAP (1 << MEM_CGROUP_RECLAIM_NOSWAP_BIT)
270 #define MEM_CGROUP_RECLAIM_SHRINK_BIT 0x1
271 #define MEM_CGROUP_RECLAIM_SHRINK (1 << MEM_CGROUP_RECLAIM_SHRINK_BIT)
272 #define MEM_CGROUP_RECLAIM_SOFT_BIT 0x2
273 #define MEM_CGROUP_RECLAIM_SOFT (1 << MEM_CGROUP_RECLAIM_SOFT_BIT)
275 static void mem_cgroup_get(struct mem_cgroup *mem);
276 static void mem_cgroup_put(struct mem_cgroup *mem);
277 static struct mem_cgroup *parent_mem_cgroup(struct mem_cgroup *mem);
279 static struct mem_cgroup_per_zone *
280 mem_cgroup_zoneinfo(struct mem_cgroup *mem, int nid, int zid)
282 return &mem->info.nodeinfo[nid]->zoneinfo[zid];
285 static struct mem_cgroup_per_zone *
286 page_cgroup_zoneinfo(struct page_cgroup *pc)
288 struct mem_cgroup *mem = pc->mem_cgroup;
289 int nid = page_cgroup_nid(pc);
290 int zid = page_cgroup_zid(pc);
295 return mem_cgroup_zoneinfo(mem, nid, zid);
298 static struct mem_cgroup_tree_per_zone *
299 soft_limit_tree_node_zone(int nid, int zid)
301 return &soft_limit_tree.rb_tree_per_node[nid]->rb_tree_per_zone[zid];
304 static struct mem_cgroup_tree_per_zone *
305 soft_limit_tree_from_page(struct page *page)
307 int nid = page_to_nid(page);
308 int zid = page_zonenum(page);
310 return &soft_limit_tree.rb_tree_per_node[nid]->rb_tree_per_zone[zid];
314 __mem_cgroup_insert_exceeded(struct mem_cgroup *mem,
315 struct mem_cgroup_per_zone *mz,
316 struct mem_cgroup_tree_per_zone *mctz)
318 struct rb_node **p = &mctz->rb_root.rb_node;
319 struct rb_node *parent = NULL;
320 struct mem_cgroup_per_zone *mz_node;
325 mz->usage_in_excess = res_counter_soft_limit_excess(&mem->res);
328 mz_node = rb_entry(parent, struct mem_cgroup_per_zone,
330 if (mz->usage_in_excess < mz_node->usage_in_excess)
333 * We can't avoid mem cgroups that are over their soft
334 * limit by the same amount
336 else if (mz->usage_in_excess >= mz_node->usage_in_excess)
339 rb_link_node(&mz->tree_node, parent, p);
340 rb_insert_color(&mz->tree_node, &mctz->rb_root);
345 __mem_cgroup_remove_exceeded(struct mem_cgroup *mem,
346 struct mem_cgroup_per_zone *mz,
347 struct mem_cgroup_tree_per_zone *mctz)
351 rb_erase(&mz->tree_node, &mctz->rb_root);
356 mem_cgroup_insert_exceeded(struct mem_cgroup *mem,
357 struct mem_cgroup_per_zone *mz,
358 struct mem_cgroup_tree_per_zone *mctz)
360 spin_lock(&mctz->lock);
361 __mem_cgroup_insert_exceeded(mem, mz, mctz);
362 spin_unlock(&mctz->lock);
366 mem_cgroup_remove_exceeded(struct mem_cgroup *mem,
367 struct mem_cgroup_per_zone *mz,
368 struct mem_cgroup_tree_per_zone *mctz)
370 spin_lock(&mctz->lock);
371 __mem_cgroup_remove_exceeded(mem, mz, mctz);
372 spin_unlock(&mctz->lock);
375 static bool mem_cgroup_soft_limit_check(struct mem_cgroup *mem)
380 struct mem_cgroup_stat_cpu *cpustat;
383 cpustat = &mem->stat.cpustat[cpu];
384 val = __mem_cgroup_stat_read_local(cpustat, MEM_CGROUP_STAT_EVENTS);
385 if (unlikely(val > SOFTLIMIT_EVENTS_THRESH)) {
386 __mem_cgroup_stat_reset_safe(cpustat, MEM_CGROUP_STAT_EVENTS);
393 static void mem_cgroup_update_tree(struct mem_cgroup *mem, struct page *page)
395 unsigned long long prev_usage_in_excess, new_usage_in_excess;
396 bool updated_tree = false;
397 struct mem_cgroup_per_zone *mz;
398 struct mem_cgroup_tree_per_zone *mctz;
400 mz = mem_cgroup_zoneinfo(mem, page_to_nid(page), page_zonenum(page));
401 mctz = soft_limit_tree_from_page(page);
404 * We do updates in lazy mode, mem's are removed
405 * lazily from the per-zone, per-node rb tree
407 prev_usage_in_excess = mz->usage_in_excess;
409 new_usage_in_excess = res_counter_soft_limit_excess(&mem->res);
410 if (prev_usage_in_excess) {
411 mem_cgroup_remove_exceeded(mem, mz, mctz);
414 if (!new_usage_in_excess)
416 mem_cgroup_insert_exceeded(mem, mz, mctz);
420 spin_lock(&mctz->lock);
421 mz->usage_in_excess = new_usage_in_excess;
422 spin_unlock(&mctz->lock);
426 static void mem_cgroup_remove_from_trees(struct mem_cgroup *mem)
429 struct mem_cgroup_per_zone *mz;
430 struct mem_cgroup_tree_per_zone *mctz;
432 for_each_node_state(node, N_POSSIBLE) {
433 for (zone = 0; zone < MAX_NR_ZONES; zone++) {
434 mz = mem_cgroup_zoneinfo(mem, node, zone);
435 mctz = soft_limit_tree_node_zone(node, zone);
436 mem_cgroup_remove_exceeded(mem, mz, mctz);
441 static inline unsigned long mem_cgroup_get_excess(struct mem_cgroup *mem)
443 return res_counter_soft_limit_excess(&mem->res) >> PAGE_SHIFT;
446 static struct mem_cgroup_per_zone *
447 __mem_cgroup_largest_soft_limit_node(struct mem_cgroup_tree_per_zone *mctz)
449 struct rb_node *rightmost = NULL;
450 struct mem_cgroup_per_zone *mz;
454 rightmost = rb_last(&mctz->rb_root);
456 goto done; /* Nothing to reclaim from */
458 mz = rb_entry(rightmost, struct mem_cgroup_per_zone, tree_node);
460 * Remove the node now but someone else can add it back,
461 * we will to add it back at the end of reclaim to its correct
462 * position in the tree.
464 __mem_cgroup_remove_exceeded(mz->mem, mz, mctz);
465 if (!res_counter_soft_limit_excess(&mz->mem->res) ||
466 !css_tryget(&mz->mem->css))
472 static struct mem_cgroup_per_zone *
473 mem_cgroup_largest_soft_limit_node(struct mem_cgroup_tree_per_zone *mctz)
475 struct mem_cgroup_per_zone *mz;
477 spin_lock(&mctz->lock);
478 mz = __mem_cgroup_largest_soft_limit_node(mctz);
479 spin_unlock(&mctz->lock);
483 static void mem_cgroup_swap_statistics(struct mem_cgroup *mem,
486 int val = (charge) ? 1 : -1;
487 struct mem_cgroup_stat *stat = &mem->stat;
488 struct mem_cgroup_stat_cpu *cpustat;
491 cpustat = &stat->cpustat[cpu];
492 __mem_cgroup_stat_add_safe(cpustat, MEM_CGROUP_STAT_SWAPOUT, val);
496 static void mem_cgroup_charge_statistics(struct mem_cgroup *mem,
497 struct page_cgroup *pc,
500 int val = (charge) ? 1 : -1;
501 struct mem_cgroup_stat *stat = &mem->stat;
502 struct mem_cgroup_stat_cpu *cpustat;
505 cpustat = &stat->cpustat[cpu];
506 if (PageCgroupCache(pc))
507 __mem_cgroup_stat_add_safe(cpustat, MEM_CGROUP_STAT_CACHE, val);
509 __mem_cgroup_stat_add_safe(cpustat, MEM_CGROUP_STAT_RSS, val);
512 __mem_cgroup_stat_add_safe(cpustat,
513 MEM_CGROUP_STAT_PGPGIN_COUNT, 1);
515 __mem_cgroup_stat_add_safe(cpustat,
516 MEM_CGROUP_STAT_PGPGOUT_COUNT, 1);
517 __mem_cgroup_stat_add_safe(cpustat, MEM_CGROUP_STAT_EVENTS, 1);
521 static unsigned long mem_cgroup_get_local_zonestat(struct mem_cgroup *mem,
525 struct mem_cgroup_per_zone *mz;
528 for_each_online_node(nid)
529 for (zid = 0; zid < MAX_NR_ZONES; zid++) {
530 mz = mem_cgroup_zoneinfo(mem, nid, zid);
531 total += MEM_CGROUP_ZSTAT(mz, idx);
536 static struct mem_cgroup *mem_cgroup_from_cont(struct cgroup *cont)
538 return container_of(cgroup_subsys_state(cont,
539 mem_cgroup_subsys_id), struct mem_cgroup,
543 struct mem_cgroup *mem_cgroup_from_task(struct task_struct *p)
546 * mm_update_next_owner() may clear mm->owner to NULL
547 * if it races with swapoff, page migration, etc.
548 * So this can be called with p == NULL.
553 return container_of(task_subsys_state(p, mem_cgroup_subsys_id),
554 struct mem_cgroup, css);
557 static struct mem_cgroup *try_get_mem_cgroup_from_mm(struct mm_struct *mm)
559 struct mem_cgroup *mem = NULL;
564 * Because we have no locks, mm->owner's may be being moved to other
565 * cgroup. We use css_tryget() here even if this looks
566 * pessimistic (rather than adding locks here).
570 mem = mem_cgroup_from_task(rcu_dereference(mm->owner));
573 } while (!css_tryget(&mem->css));
579 * Call callback function against all cgroup under hierarchy tree.
581 static int mem_cgroup_walk_tree(struct mem_cgroup *root, void *data,
582 int (*func)(struct mem_cgroup *, void *))
584 int found, ret, nextid;
585 struct cgroup_subsys_state *css;
586 struct mem_cgroup *mem;
588 if (!root->use_hierarchy)
589 return (*func)(root, data);
597 css = css_get_next(&mem_cgroup_subsys, nextid, &root->css,
599 if (css && css_tryget(css))
600 mem = container_of(css, struct mem_cgroup, css);
604 ret = (*func)(mem, data);
608 } while (!ret && css);
613 static inline bool mem_cgroup_is_root(struct mem_cgroup *mem)
615 return (mem == root_mem_cgroup);
619 * Following LRU functions are allowed to be used without PCG_LOCK.
620 * Operations are called by routine of global LRU independently from memcg.
621 * What we have to take care of here is validness of pc->mem_cgroup.
623 * Changes to pc->mem_cgroup happens when
626 * In typical case, "charge" is done before add-to-lru. Exception is SwapCache.
627 * It is added to LRU before charge.
628 * If PCG_USED bit is not set, page_cgroup is not added to this private LRU.
629 * When moving account, the page is not on LRU. It's isolated.
632 void mem_cgroup_del_lru_list(struct page *page, enum lru_list lru)
634 struct page_cgroup *pc;
635 struct mem_cgroup_per_zone *mz;
637 if (mem_cgroup_disabled())
639 pc = lookup_page_cgroup(page);
640 /* can happen while we handle swapcache. */
641 if (!TestClearPageCgroupAcctLRU(pc))
643 VM_BUG_ON(!pc->mem_cgroup);
645 * We don't check PCG_USED bit. It's cleared when the "page" is finally
646 * removed from global LRU.
648 mz = page_cgroup_zoneinfo(pc);
649 MEM_CGROUP_ZSTAT(mz, lru) -= 1;
650 if (mem_cgroup_is_root(pc->mem_cgroup))
652 VM_BUG_ON(list_empty(&pc->lru));
653 list_del_init(&pc->lru);
657 void mem_cgroup_del_lru(struct page *page)
659 mem_cgroup_del_lru_list(page, page_lru(page));
662 void mem_cgroup_rotate_lru_list(struct page *page, enum lru_list lru)
664 struct mem_cgroup_per_zone *mz;
665 struct page_cgroup *pc;
667 if (mem_cgroup_disabled())
670 pc = lookup_page_cgroup(page);
672 * Used bit is set without atomic ops but after smp_wmb().
673 * For making pc->mem_cgroup visible, insert smp_rmb() here.
676 /* unused or root page is not rotated. */
677 if (!PageCgroupUsed(pc) || mem_cgroup_is_root(pc->mem_cgroup))
679 mz = page_cgroup_zoneinfo(pc);
680 list_move(&pc->lru, &mz->lists[lru]);
683 void mem_cgroup_add_lru_list(struct page *page, enum lru_list lru)
685 struct page_cgroup *pc;
686 struct mem_cgroup_per_zone *mz;
688 if (mem_cgroup_disabled())
690 pc = lookup_page_cgroup(page);
691 VM_BUG_ON(PageCgroupAcctLRU(pc));
693 * Used bit is set without atomic ops but after smp_wmb().
694 * For making pc->mem_cgroup visible, insert smp_rmb() here.
697 if (!PageCgroupUsed(pc))
700 mz = page_cgroup_zoneinfo(pc);
701 MEM_CGROUP_ZSTAT(mz, lru) += 1;
702 SetPageCgroupAcctLRU(pc);
703 if (mem_cgroup_is_root(pc->mem_cgroup))
705 list_add(&pc->lru, &mz->lists[lru]);
709 * At handling SwapCache, pc->mem_cgroup may be changed while it's linked to
710 * lru because the page may.be reused after it's fully uncharged (because of
711 * SwapCache behavior).To handle that, unlink page_cgroup from LRU when charge
712 * it again. This function is only used to charge SwapCache. It's done under
713 * lock_page and expected that zone->lru_lock is never held.
715 static void mem_cgroup_lru_del_before_commit_swapcache(struct page *page)
718 struct zone *zone = page_zone(page);
719 struct page_cgroup *pc = lookup_page_cgroup(page);
721 spin_lock_irqsave(&zone->lru_lock, flags);
723 * Forget old LRU when this page_cgroup is *not* used. This Used bit
724 * is guarded by lock_page() because the page is SwapCache.
726 if (!PageCgroupUsed(pc))
727 mem_cgroup_del_lru_list(page, page_lru(page));
728 spin_unlock_irqrestore(&zone->lru_lock, flags);
731 static void mem_cgroup_lru_add_after_commit_swapcache(struct page *page)
734 struct zone *zone = page_zone(page);
735 struct page_cgroup *pc = lookup_page_cgroup(page);
737 spin_lock_irqsave(&zone->lru_lock, flags);
738 /* link when the page is linked to LRU but page_cgroup isn't */
739 if (PageLRU(page) && !PageCgroupAcctLRU(pc))
740 mem_cgroup_add_lru_list(page, page_lru(page));
741 spin_unlock_irqrestore(&zone->lru_lock, flags);
745 void mem_cgroup_move_lists(struct page *page,
746 enum lru_list from, enum lru_list to)
748 if (mem_cgroup_disabled())
750 mem_cgroup_del_lru_list(page, from);
751 mem_cgroup_add_lru_list(page, to);
754 int task_in_mem_cgroup(struct task_struct *task, const struct mem_cgroup *mem)
757 struct mem_cgroup *curr = NULL;
761 curr = try_get_mem_cgroup_from_mm(task->mm);
766 if (curr->use_hierarchy)
767 ret = css_is_ancestor(&curr->css, &mem->css);
775 * prev_priority control...this will be used in memory reclaim path.
777 int mem_cgroup_get_reclaim_priority(struct mem_cgroup *mem)
781 spin_lock(&mem->reclaim_param_lock);
782 prev_priority = mem->prev_priority;
783 spin_unlock(&mem->reclaim_param_lock);
785 return prev_priority;
788 void mem_cgroup_note_reclaim_priority(struct mem_cgroup *mem, int priority)
790 spin_lock(&mem->reclaim_param_lock);
791 if (priority < mem->prev_priority)
792 mem->prev_priority = priority;
793 spin_unlock(&mem->reclaim_param_lock);
796 void mem_cgroup_record_reclaim_priority(struct mem_cgroup *mem, int priority)
798 spin_lock(&mem->reclaim_param_lock);
799 mem->prev_priority = priority;
800 spin_unlock(&mem->reclaim_param_lock);
803 static int calc_inactive_ratio(struct mem_cgroup *memcg, unsigned long *present_pages)
805 unsigned long active;
806 unsigned long inactive;
808 unsigned long inactive_ratio;
810 inactive = mem_cgroup_get_local_zonestat(memcg, LRU_INACTIVE_ANON);
811 active = mem_cgroup_get_local_zonestat(memcg, LRU_ACTIVE_ANON);
813 gb = (inactive + active) >> (30 - PAGE_SHIFT);
815 inactive_ratio = int_sqrt(10 * gb);
820 present_pages[0] = inactive;
821 present_pages[1] = active;
824 return inactive_ratio;
827 int mem_cgroup_inactive_anon_is_low(struct mem_cgroup *memcg)
829 unsigned long active;
830 unsigned long inactive;
831 unsigned long present_pages[2];
832 unsigned long inactive_ratio;
834 inactive_ratio = calc_inactive_ratio(memcg, present_pages);
836 inactive = present_pages[0];
837 active = present_pages[1];
839 if (inactive * inactive_ratio < active)
845 int mem_cgroup_inactive_file_is_low(struct mem_cgroup *memcg)
847 unsigned long active;
848 unsigned long inactive;
850 inactive = mem_cgroup_get_local_zonestat(memcg, LRU_INACTIVE_FILE);
851 active = mem_cgroup_get_local_zonestat(memcg, LRU_ACTIVE_FILE);
853 return (active > inactive);
856 unsigned long mem_cgroup_zone_nr_pages(struct mem_cgroup *memcg,
860 int nid = zone->zone_pgdat->node_id;
861 int zid = zone_idx(zone);
862 struct mem_cgroup_per_zone *mz = mem_cgroup_zoneinfo(memcg, nid, zid);
864 return MEM_CGROUP_ZSTAT(mz, lru);
867 struct zone_reclaim_stat *mem_cgroup_get_reclaim_stat(struct mem_cgroup *memcg,
870 int nid = zone->zone_pgdat->node_id;
871 int zid = zone_idx(zone);
872 struct mem_cgroup_per_zone *mz = mem_cgroup_zoneinfo(memcg, nid, zid);
874 return &mz->reclaim_stat;
877 struct zone_reclaim_stat *
878 mem_cgroup_get_reclaim_stat_from_page(struct page *page)
880 struct page_cgroup *pc;
881 struct mem_cgroup_per_zone *mz;
883 if (mem_cgroup_disabled())
886 pc = lookup_page_cgroup(page);
888 * Used bit is set without atomic ops but after smp_wmb().
889 * For making pc->mem_cgroup visible, insert smp_rmb() here.
892 if (!PageCgroupUsed(pc))
895 mz = page_cgroup_zoneinfo(pc);
899 return &mz->reclaim_stat;
902 unsigned long mem_cgroup_isolate_pages(unsigned long nr_to_scan,
903 struct list_head *dst,
904 unsigned long *scanned, int order,
905 int mode, struct zone *z,
906 struct mem_cgroup *mem_cont,
907 int active, int file)
909 unsigned long nr_taken = 0;
913 struct list_head *src;
914 struct page_cgroup *pc, *tmp;
915 int nid = z->zone_pgdat->node_id;
916 int zid = zone_idx(z);
917 struct mem_cgroup_per_zone *mz;
918 int lru = LRU_FILE * file + active;
922 mz = mem_cgroup_zoneinfo(mem_cont, nid, zid);
923 src = &mz->lists[lru];
926 list_for_each_entry_safe_reverse(pc, tmp, src, lru) {
927 if (scan >= nr_to_scan)
931 if (unlikely(!PageCgroupUsed(pc)))
933 if (unlikely(!PageLRU(page)))
937 ret = __isolate_lru_page(page, mode, file);
940 list_move(&page->lru, dst);
941 mem_cgroup_del_lru(page);
945 /* we don't affect global LRU but rotate in our LRU */
946 mem_cgroup_rotate_lru_list(page, page_lru(page));
957 #define mem_cgroup_from_res_counter(counter, member) \
958 container_of(counter, struct mem_cgroup, member)
960 static bool mem_cgroup_check_under_limit(struct mem_cgroup *mem)
962 if (do_swap_account) {
963 if (res_counter_check_under_limit(&mem->res) &&
964 res_counter_check_under_limit(&mem->memsw))
967 if (res_counter_check_under_limit(&mem->res))
972 static unsigned int get_swappiness(struct mem_cgroup *memcg)
974 struct cgroup *cgrp = memcg->css.cgroup;
975 unsigned int swappiness;
978 if (cgrp->parent == NULL)
979 return vm_swappiness;
981 spin_lock(&memcg->reclaim_param_lock);
982 swappiness = memcg->swappiness;
983 spin_unlock(&memcg->reclaim_param_lock);
988 static int mem_cgroup_count_children_cb(struct mem_cgroup *mem, void *data)
996 * mem_cgroup_print_mem_info: Called from OOM with tasklist_lock held in read mode.
997 * @memcg: The memory cgroup that went over limit
998 * @p: Task that is going to be killed
1000 * NOTE: @memcg and @p's mem_cgroup can be different when hierarchy is
1003 void mem_cgroup_print_oom_info(struct mem_cgroup *memcg, struct task_struct *p)
1005 struct cgroup *task_cgrp;
1006 struct cgroup *mem_cgrp;
1008 * Need a buffer in BSS, can't rely on allocations. The code relies
1009 * on the assumption that OOM is serialized for memory controller.
1010 * If this assumption is broken, revisit this code.
1012 static char memcg_name[PATH_MAX];
1021 mem_cgrp = memcg->css.cgroup;
1022 task_cgrp = task_cgroup(p, mem_cgroup_subsys_id);
1024 ret = cgroup_path(task_cgrp, memcg_name, PATH_MAX);
1027 * Unfortunately, we are unable to convert to a useful name
1028 * But we'll still print out the usage information
1035 printk(KERN_INFO "Task in %s killed", memcg_name);
1038 ret = cgroup_path(mem_cgrp, memcg_name, PATH_MAX);
1046 * Continues from above, so we don't need an KERN_ level
1048 printk(KERN_CONT " as a result of limit of %s\n", memcg_name);
1051 printk(KERN_INFO "memory: usage %llukB, limit %llukB, failcnt %llu\n",
1052 res_counter_read_u64(&memcg->res, RES_USAGE) >> 10,
1053 res_counter_read_u64(&memcg->res, RES_LIMIT) >> 10,
1054 res_counter_read_u64(&memcg->res, RES_FAILCNT));
1055 printk(KERN_INFO "memory+swap: usage %llukB, limit %llukB, "
1057 res_counter_read_u64(&memcg->memsw, RES_USAGE) >> 10,
1058 res_counter_read_u64(&memcg->memsw, RES_LIMIT) >> 10,
1059 res_counter_read_u64(&memcg->memsw, RES_FAILCNT));
1063 * This function returns the number of memcg under hierarchy tree. Returns
1064 * 1(self count) if no children.
1066 static int mem_cgroup_count_children(struct mem_cgroup *mem)
1069 mem_cgroup_walk_tree(mem, &num, mem_cgroup_count_children_cb);
1074 * Visit the first child (need not be the first child as per the ordering
1075 * of the cgroup list, since we track last_scanned_child) of @mem and use
1076 * that to reclaim free pages from.
1078 static struct mem_cgroup *
1079 mem_cgroup_select_victim(struct mem_cgroup *root_mem)
1081 struct mem_cgroup *ret = NULL;
1082 struct cgroup_subsys_state *css;
1085 if (!root_mem->use_hierarchy) {
1086 css_get(&root_mem->css);
1092 nextid = root_mem->last_scanned_child + 1;
1093 css = css_get_next(&mem_cgroup_subsys, nextid, &root_mem->css,
1095 if (css && css_tryget(css))
1096 ret = container_of(css, struct mem_cgroup, css);
1099 /* Updates scanning parameter */
1100 spin_lock(&root_mem->reclaim_param_lock);
1102 /* this means start scan from ID:1 */
1103 root_mem->last_scanned_child = 0;
1105 root_mem->last_scanned_child = found;
1106 spin_unlock(&root_mem->reclaim_param_lock);
1113 * Scan the hierarchy if needed to reclaim memory. We remember the last child
1114 * we reclaimed from, so that we don't end up penalizing one child extensively
1115 * based on its position in the children list.
1117 * root_mem is the original ancestor that we've been reclaim from.
1119 * We give up and return to the caller when we visit root_mem twice.
1120 * (other groups can be removed while we're walking....)
1122 * If shrink==true, for avoiding to free too much, this returns immedieately.
1124 static int mem_cgroup_hierarchical_reclaim(struct mem_cgroup *root_mem,
1127 unsigned long reclaim_options)
1129 struct mem_cgroup *victim;
1132 bool noswap = reclaim_options & MEM_CGROUP_RECLAIM_NOSWAP;
1133 bool shrink = reclaim_options & MEM_CGROUP_RECLAIM_SHRINK;
1134 bool check_soft = reclaim_options & MEM_CGROUP_RECLAIM_SOFT;
1135 unsigned long excess = mem_cgroup_get_excess(root_mem);
1137 /* If memsw_is_minimum==1, swap-out is of-no-use. */
1138 if (root_mem->memsw_is_minimum)
1142 victim = mem_cgroup_select_victim(root_mem);
1143 if (victim == root_mem) {
1147 * If we have not been able to reclaim
1148 * anything, it might because there are
1149 * no reclaimable pages under this hierarchy
1151 if (!check_soft || !total) {
1152 css_put(&victim->css);
1156 * We want to do more targetted reclaim.
1157 * excess >> 2 is not to excessive so as to
1158 * reclaim too much, nor too less that we keep
1159 * coming back to reclaim from this cgroup
1161 if (total >= (excess >> 2) ||
1162 (loop > MEM_CGROUP_MAX_RECLAIM_LOOPS)) {
1163 css_put(&victim->css);
1168 if (!mem_cgroup_local_usage(&victim->stat)) {
1169 /* this cgroup's local usage == 0 */
1170 css_put(&victim->css);
1173 /* we use swappiness of local cgroup */
1175 ret = mem_cgroup_shrink_node_zone(victim, gfp_mask,
1176 noswap, get_swappiness(victim), zone,
1177 zone->zone_pgdat->node_id);
1179 ret = try_to_free_mem_cgroup_pages(victim, gfp_mask,
1180 noswap, get_swappiness(victim));
1181 css_put(&victim->css);
1183 * At shrinking usage, we can't check we should stop here or
1184 * reclaim more. It's depends on callers. last_scanned_child
1185 * will work enough for keeping fairness under tree.
1191 if (res_counter_check_under_soft_limit(&root_mem->res))
1193 } else if (mem_cgroup_check_under_limit(root_mem))
1199 bool mem_cgroup_oom_called(struct task_struct *task)
1202 struct mem_cgroup *mem;
1203 struct mm_struct *mm;
1209 mem = mem_cgroup_from_task(rcu_dereference(mm->owner));
1210 if (mem && time_before(jiffies, mem->last_oom_jiffies + HZ/10))
1216 static int record_last_oom_cb(struct mem_cgroup *mem, void *data)
1218 mem->last_oom_jiffies = jiffies;
1222 static void record_last_oom(struct mem_cgroup *mem)
1224 mem_cgroup_walk_tree(mem, NULL, record_last_oom_cb);
1228 * Currently used to update mapped file statistics, but the routine can be
1229 * generalized to update other statistics as well.
1231 void mem_cgroup_update_mapped_file_stat(struct page *page, int val)
1233 struct mem_cgroup *mem;
1234 struct mem_cgroup_stat *stat;
1235 struct mem_cgroup_stat_cpu *cpustat;
1237 struct page_cgroup *pc;
1239 if (!page_is_file_cache(page))
1242 pc = lookup_page_cgroup(page);
1246 lock_page_cgroup(pc);
1247 mem = pc->mem_cgroup;
1251 if (!PageCgroupUsed(pc))
1255 * Preemption is already disabled, we don't need get_cpu()
1257 cpu = smp_processor_id();
1259 cpustat = &stat->cpustat[cpu];
1261 __mem_cgroup_stat_add_safe(cpustat, MEM_CGROUP_STAT_MAPPED_FILE, val);
1263 unlock_page_cgroup(pc);
1267 * Unlike exported interface, "oom" parameter is added. if oom==true,
1268 * oom-killer can be invoked.
1270 static int __mem_cgroup_try_charge(struct mm_struct *mm,
1271 gfp_t gfp_mask, struct mem_cgroup **memcg,
1272 bool oom, struct page *page)
1274 struct mem_cgroup *mem, *mem_over_limit, *mem_over_soft_limit;
1275 int nr_retries = MEM_CGROUP_RECLAIM_RETRIES;
1276 struct res_counter *fail_res, *soft_fail_res = NULL;
1278 if (unlikely(test_thread_flag(TIF_MEMDIE))) {
1279 /* Don't account this! */
1285 * We always charge the cgroup the mm_struct belongs to.
1286 * The mm_struct's mem_cgroup changes on task migration if the
1287 * thread group leader migrates. It's possible that mm is not
1288 * set, if so charge the init_mm (happens for pagecache usage).
1292 mem = try_get_mem_cgroup_from_mm(mm);
1300 VM_BUG_ON(css_is_removed(&mem->css));
1304 unsigned long flags = 0;
1306 if (mem_cgroup_is_root(mem))
1308 ret = res_counter_charge(&mem->res, PAGE_SIZE, &fail_res,
1311 if (!do_swap_account)
1313 ret = res_counter_charge(&mem->memsw, PAGE_SIZE,
1317 /* mem+swap counter fails */
1318 res_counter_uncharge(&mem->res, PAGE_SIZE, NULL);
1319 flags |= MEM_CGROUP_RECLAIM_NOSWAP;
1320 mem_over_limit = mem_cgroup_from_res_counter(fail_res,
1323 /* mem counter fails */
1324 mem_over_limit = mem_cgroup_from_res_counter(fail_res,
1327 if (!(gfp_mask & __GFP_WAIT))
1330 ret = mem_cgroup_hierarchical_reclaim(mem_over_limit, NULL,
1336 * try_to_free_mem_cgroup_pages() might not give us a full
1337 * picture of reclaim. Some pages are reclaimed and might be
1338 * moved to swap cache or just unmapped from the cgroup.
1339 * Check the limit again to see if the reclaim reduced the
1340 * current usage of the cgroup before giving up
1343 if (mem_cgroup_check_under_limit(mem_over_limit))
1346 if (!nr_retries--) {
1348 mutex_lock(&memcg_tasklist);
1349 mem_cgroup_out_of_memory(mem_over_limit, gfp_mask);
1350 mutex_unlock(&memcg_tasklist);
1351 record_last_oom(mem_over_limit);
1357 * Insert just the ancestor, we should trickle down to the correct
1358 * cgroup for reclaim, since the other nodes will be below their
1361 if (soft_fail_res) {
1362 mem_over_soft_limit =
1363 mem_cgroup_from_res_counter(soft_fail_res, res);
1364 if (mem_cgroup_soft_limit_check(mem_over_soft_limit))
1365 mem_cgroup_update_tree(mem_over_soft_limit, page);
1375 * A helper function to get mem_cgroup from ID. must be called under
1376 * rcu_read_lock(). The caller must check css_is_removed() or some if
1377 * it's concern. (dropping refcnt from swap can be called against removed
1380 static struct mem_cgroup *mem_cgroup_lookup(unsigned short id)
1382 struct cgroup_subsys_state *css;
1384 /* ID 0 is unused ID */
1387 css = css_lookup(&mem_cgroup_subsys, id);
1390 return container_of(css, struct mem_cgroup, css);
1393 static struct mem_cgroup *try_get_mem_cgroup_from_swapcache(struct page *page)
1395 struct mem_cgroup *mem;
1396 struct page_cgroup *pc;
1400 VM_BUG_ON(!PageLocked(page));
1402 if (!PageSwapCache(page))
1405 pc = lookup_page_cgroup(page);
1406 lock_page_cgroup(pc);
1407 if (PageCgroupUsed(pc)) {
1408 mem = pc->mem_cgroup;
1409 if (mem && !css_tryget(&mem->css))
1412 ent.val = page_private(page);
1413 id = lookup_swap_cgroup(ent);
1415 mem = mem_cgroup_lookup(id);
1416 if (mem && !css_tryget(&mem->css))
1420 unlock_page_cgroup(pc);
1425 * commit a charge got by __mem_cgroup_try_charge() and makes page_cgroup to be
1426 * USED state. If already USED, uncharge and return.
1429 static void __mem_cgroup_commit_charge(struct mem_cgroup *mem,
1430 struct page_cgroup *pc,
1431 enum charge_type ctype)
1433 /* try_charge() can return NULL to *memcg, taking care of it. */
1437 lock_page_cgroup(pc);
1438 if (unlikely(PageCgroupUsed(pc))) {
1439 unlock_page_cgroup(pc);
1440 if (!mem_cgroup_is_root(mem)) {
1441 res_counter_uncharge(&mem->res, PAGE_SIZE, NULL);
1442 if (do_swap_account)
1443 res_counter_uncharge(&mem->memsw, PAGE_SIZE,
1450 pc->mem_cgroup = mem;
1452 * We access a page_cgroup asynchronously without lock_page_cgroup().
1453 * Especially when a page_cgroup is taken from a page, pc->mem_cgroup
1454 * is accessed after testing USED bit. To make pc->mem_cgroup visible
1455 * before USED bit, we need memory barrier here.
1456 * See mem_cgroup_add_lru_list(), etc.
1460 case MEM_CGROUP_CHARGE_TYPE_CACHE:
1461 case MEM_CGROUP_CHARGE_TYPE_SHMEM:
1462 SetPageCgroupCache(pc);
1463 SetPageCgroupUsed(pc);
1465 case MEM_CGROUP_CHARGE_TYPE_MAPPED:
1466 ClearPageCgroupCache(pc);
1467 SetPageCgroupUsed(pc);
1473 mem_cgroup_charge_statistics(mem, pc, true);
1475 unlock_page_cgroup(pc);
1479 * mem_cgroup_move_account - move account of the page
1480 * @pc: page_cgroup of the page.
1481 * @from: mem_cgroup which the page is moved from.
1482 * @to: mem_cgroup which the page is moved to. @from != @to.
1484 * The caller must confirm following.
1485 * - page is not on LRU (isolate_page() is useful.)
1487 * returns 0 at success,
1488 * returns -EBUSY when lock is busy or "pc" is unstable.
1490 * This function does "uncharge" from old cgroup but doesn't do "charge" to
1491 * new cgroup. It should be done by a caller.
1494 static int mem_cgroup_move_account(struct page_cgroup *pc,
1495 struct mem_cgroup *from, struct mem_cgroup *to)
1497 struct mem_cgroup_per_zone *from_mz, *to_mz;
1502 struct mem_cgroup_stat *stat;
1503 struct mem_cgroup_stat_cpu *cpustat;
1505 VM_BUG_ON(from == to);
1506 VM_BUG_ON(PageLRU(pc->page));
1508 nid = page_cgroup_nid(pc);
1509 zid = page_cgroup_zid(pc);
1510 from_mz = mem_cgroup_zoneinfo(from, nid, zid);
1511 to_mz = mem_cgroup_zoneinfo(to, nid, zid);
1513 if (!trylock_page_cgroup(pc))
1516 if (!PageCgroupUsed(pc))
1519 if (pc->mem_cgroup != from)
1522 if (!mem_cgroup_is_root(from))
1523 res_counter_uncharge(&from->res, PAGE_SIZE, NULL);
1524 mem_cgroup_charge_statistics(from, pc, false);
1527 if (page_is_file_cache(page) && page_mapped(page)) {
1528 cpu = smp_processor_id();
1529 /* Update mapped_file data for mem_cgroup "from" */
1531 cpustat = &stat->cpustat[cpu];
1532 __mem_cgroup_stat_add_safe(cpustat, MEM_CGROUP_STAT_MAPPED_FILE,
1535 /* Update mapped_file data for mem_cgroup "to" */
1537 cpustat = &stat->cpustat[cpu];
1538 __mem_cgroup_stat_add_safe(cpustat, MEM_CGROUP_STAT_MAPPED_FILE,
1542 if (do_swap_account && !mem_cgroup_is_root(from))
1543 res_counter_uncharge(&from->memsw, PAGE_SIZE, NULL);
1544 css_put(&from->css);
1547 pc->mem_cgroup = to;
1548 mem_cgroup_charge_statistics(to, pc, true);
1551 unlock_page_cgroup(pc);
1553 * We charges against "to" which may not have any tasks. Then, "to"
1554 * can be under rmdir(). But in current implementation, caller of
1555 * this function is just force_empty() and it's garanteed that
1556 * "to" is never removed. So, we don't check rmdir status here.
1562 * move charges to its parent.
1565 static int mem_cgroup_move_parent(struct page_cgroup *pc,
1566 struct mem_cgroup *child,
1569 struct page *page = pc->page;
1570 struct cgroup *cg = child->css.cgroup;
1571 struct cgroup *pcg = cg->parent;
1572 struct mem_cgroup *parent;
1580 parent = mem_cgroup_from_cont(pcg);
1583 ret = __mem_cgroup_try_charge(NULL, gfp_mask, &parent, false, page);
1587 if (!get_page_unless_zero(page)) {
1592 ret = isolate_lru_page(page);
1597 ret = mem_cgroup_move_account(pc, child, parent);
1599 putback_lru_page(page);
1602 /* drop extra refcnt by try_charge() */
1603 css_put(&parent->css);
1610 /* drop extra refcnt by try_charge() */
1611 css_put(&parent->css);
1612 /* uncharge if move fails */
1613 if (!mem_cgroup_is_root(parent)) {
1614 res_counter_uncharge(&parent->res, PAGE_SIZE, NULL);
1615 if (do_swap_account)
1616 res_counter_uncharge(&parent->memsw, PAGE_SIZE, NULL);
1622 * Charge the memory controller for page usage.
1624 * 0 if the charge was successful
1625 * < 0 if the cgroup is over its limit
1627 static int mem_cgroup_charge_common(struct page *page, struct mm_struct *mm,
1628 gfp_t gfp_mask, enum charge_type ctype,
1629 struct mem_cgroup *memcg)
1631 struct mem_cgroup *mem;
1632 struct page_cgroup *pc;
1635 pc = lookup_page_cgroup(page);
1636 /* can happen at boot */
1642 ret = __mem_cgroup_try_charge(mm, gfp_mask, &mem, true, page);
1646 __mem_cgroup_commit_charge(mem, pc, ctype);
1650 int mem_cgroup_newpage_charge(struct page *page,
1651 struct mm_struct *mm, gfp_t gfp_mask)
1653 if (mem_cgroup_disabled())
1655 if (PageCompound(page))
1658 * If already mapped, we don't have to account.
1659 * If page cache, page->mapping has address_space.
1660 * But page->mapping may have out-of-use anon_vma pointer,
1661 * detecit it by PageAnon() check. newly-mapped-anon's page->mapping
1664 if (page_mapped(page) || (page->mapping && !PageAnon(page)))
1668 return mem_cgroup_charge_common(page, mm, gfp_mask,
1669 MEM_CGROUP_CHARGE_TYPE_MAPPED, NULL);
1673 __mem_cgroup_commit_charge_swapin(struct page *page, struct mem_cgroup *ptr,
1674 enum charge_type ctype);
1676 int mem_cgroup_cache_charge(struct page *page, struct mm_struct *mm,
1679 struct mem_cgroup *mem = NULL;
1682 if (mem_cgroup_disabled())
1684 if (PageCompound(page))
1687 * Corner case handling. This is called from add_to_page_cache()
1688 * in usual. But some FS (shmem) precharges this page before calling it
1689 * and call add_to_page_cache() with GFP_NOWAIT.
1691 * For GFP_NOWAIT case, the page may be pre-charged before calling
1692 * add_to_page_cache(). (See shmem.c) check it here and avoid to call
1693 * charge twice. (It works but has to pay a bit larger cost.)
1694 * And when the page is SwapCache, it should take swap information
1695 * into account. This is under lock_page() now.
1697 if (!(gfp_mask & __GFP_WAIT)) {
1698 struct page_cgroup *pc;
1701 pc = lookup_page_cgroup(page);
1704 lock_page_cgroup(pc);
1705 if (PageCgroupUsed(pc)) {
1706 unlock_page_cgroup(pc);
1709 unlock_page_cgroup(pc);
1712 if (unlikely(!mm && !mem))
1715 if (page_is_file_cache(page))
1716 return mem_cgroup_charge_common(page, mm, gfp_mask,
1717 MEM_CGROUP_CHARGE_TYPE_CACHE, NULL);
1720 if (PageSwapCache(page)) {
1721 ret = mem_cgroup_try_charge_swapin(mm, page, gfp_mask, &mem);
1723 __mem_cgroup_commit_charge_swapin(page, mem,
1724 MEM_CGROUP_CHARGE_TYPE_SHMEM);
1726 ret = mem_cgroup_charge_common(page, mm, gfp_mask,
1727 MEM_CGROUP_CHARGE_TYPE_SHMEM, mem);
1733 * While swap-in, try_charge -> commit or cancel, the page is locked.
1734 * And when try_charge() successfully returns, one refcnt to memcg without
1735 * struct page_cgroup is aquired. This refcnt will be cumsumed by
1736 * "commit()" or removed by "cancel()"
1738 int mem_cgroup_try_charge_swapin(struct mm_struct *mm,
1740 gfp_t mask, struct mem_cgroup **ptr)
1742 struct mem_cgroup *mem;
1745 if (mem_cgroup_disabled())
1748 if (!do_swap_account)
1751 * A racing thread's fault, or swapoff, may have already updated
1752 * the pte, and even removed page from swap cache: return success
1753 * to go on to do_swap_page()'s pte_same() test, which should fail.
1755 if (!PageSwapCache(page))
1757 mem = try_get_mem_cgroup_from_swapcache(page);
1761 ret = __mem_cgroup_try_charge(NULL, mask, ptr, true, page);
1762 /* drop extra refcnt from tryget */
1768 return __mem_cgroup_try_charge(mm, mask, ptr, true, page);
1772 __mem_cgroup_commit_charge_swapin(struct page *page, struct mem_cgroup *ptr,
1773 enum charge_type ctype)
1775 struct page_cgroup *pc;
1777 if (mem_cgroup_disabled())
1781 cgroup_exclude_rmdir(&ptr->css);
1782 pc = lookup_page_cgroup(page);
1783 mem_cgroup_lru_del_before_commit_swapcache(page);
1784 __mem_cgroup_commit_charge(ptr, pc, ctype);
1785 mem_cgroup_lru_add_after_commit_swapcache(page);
1787 * Now swap is on-memory. This means this page may be
1788 * counted both as mem and swap....double count.
1789 * Fix it by uncharging from memsw. Basically, this SwapCache is stable
1790 * under lock_page(). But in do_swap_page()::memory.c, reuse_swap_page()
1791 * may call delete_from_swap_cache() before reach here.
1793 if (do_swap_account && PageSwapCache(page)) {
1794 swp_entry_t ent = {.val = page_private(page)};
1796 struct mem_cgroup *memcg;
1798 id = swap_cgroup_record(ent, 0);
1800 memcg = mem_cgroup_lookup(id);
1803 * This recorded memcg can be obsolete one. So, avoid
1804 * calling css_tryget
1806 if (!mem_cgroup_is_root(memcg))
1807 res_counter_uncharge(&memcg->memsw, PAGE_SIZE,
1809 mem_cgroup_swap_statistics(memcg, false);
1810 mem_cgroup_put(memcg);
1815 * At swapin, we may charge account against cgroup which has no tasks.
1816 * So, rmdir()->pre_destroy() can be called while we do this charge.
1817 * In that case, we need to call pre_destroy() again. check it here.
1819 cgroup_release_and_wakeup_rmdir(&ptr->css);
1822 void mem_cgroup_commit_charge_swapin(struct page *page, struct mem_cgroup *ptr)
1824 __mem_cgroup_commit_charge_swapin(page, ptr,
1825 MEM_CGROUP_CHARGE_TYPE_MAPPED);
1828 void mem_cgroup_cancel_charge_swapin(struct mem_cgroup *mem)
1830 if (mem_cgroup_disabled())
1834 if (!mem_cgroup_is_root(mem)) {
1835 res_counter_uncharge(&mem->res, PAGE_SIZE, NULL);
1836 if (do_swap_account)
1837 res_counter_uncharge(&mem->memsw, PAGE_SIZE, NULL);
1844 * uncharge if !page_mapped(page)
1846 static struct mem_cgroup *
1847 __mem_cgroup_uncharge_common(struct page *page, enum charge_type ctype)
1849 struct page_cgroup *pc;
1850 struct mem_cgroup *mem = NULL;
1851 struct mem_cgroup_per_zone *mz;
1852 bool soft_limit_excess = false;
1854 if (mem_cgroup_disabled())
1857 if (PageSwapCache(page))
1861 * Check if our page_cgroup is valid
1863 pc = lookup_page_cgroup(page);
1864 if (unlikely(!pc || !PageCgroupUsed(pc)))
1867 lock_page_cgroup(pc);
1869 mem = pc->mem_cgroup;
1871 if (!PageCgroupUsed(pc))
1875 case MEM_CGROUP_CHARGE_TYPE_MAPPED:
1876 case MEM_CGROUP_CHARGE_TYPE_DROP:
1877 if (page_mapped(page))
1880 case MEM_CGROUP_CHARGE_TYPE_SWAPOUT:
1881 if (!PageAnon(page)) { /* Shared memory */
1882 if (page->mapping && !page_is_file_cache(page))
1884 } else if (page_mapped(page)) /* Anon */
1891 if (!mem_cgroup_is_root(mem)) {
1892 res_counter_uncharge(&mem->res, PAGE_SIZE, &soft_limit_excess);
1893 if (do_swap_account &&
1894 (ctype != MEM_CGROUP_CHARGE_TYPE_SWAPOUT))
1895 res_counter_uncharge(&mem->memsw, PAGE_SIZE, NULL);
1897 if (ctype == MEM_CGROUP_CHARGE_TYPE_SWAPOUT)
1898 mem_cgroup_swap_statistics(mem, true);
1899 mem_cgroup_charge_statistics(mem, pc, false);
1901 ClearPageCgroupUsed(pc);
1903 * pc->mem_cgroup is not cleared here. It will be accessed when it's
1904 * freed from LRU. This is safe because uncharged page is expected not
1905 * to be reused (freed soon). Exception is SwapCache, it's handled by
1906 * special functions.
1909 mz = page_cgroup_zoneinfo(pc);
1910 unlock_page_cgroup(pc);
1912 if (soft_limit_excess && mem_cgroup_soft_limit_check(mem))
1913 mem_cgroup_update_tree(mem, page);
1914 /* at swapout, this memcg will be accessed to record to swap */
1915 if (ctype != MEM_CGROUP_CHARGE_TYPE_SWAPOUT)
1921 unlock_page_cgroup(pc);
1925 void mem_cgroup_uncharge_page(struct page *page)
1928 if (page_mapped(page))
1930 if (page->mapping && !PageAnon(page))
1932 __mem_cgroup_uncharge_common(page, MEM_CGROUP_CHARGE_TYPE_MAPPED);
1935 void mem_cgroup_uncharge_cache_page(struct page *page)
1937 VM_BUG_ON(page_mapped(page));
1938 VM_BUG_ON(page->mapping);
1939 __mem_cgroup_uncharge_common(page, MEM_CGROUP_CHARGE_TYPE_CACHE);
1944 * called after __delete_from_swap_cache() and drop "page" account.
1945 * memcg information is recorded to swap_cgroup of "ent"
1948 mem_cgroup_uncharge_swapcache(struct page *page, swp_entry_t ent, bool swapout)
1950 struct mem_cgroup *memcg;
1951 int ctype = MEM_CGROUP_CHARGE_TYPE_SWAPOUT;
1953 if (!swapout) /* this was a swap cache but the swap is unused ! */
1954 ctype = MEM_CGROUP_CHARGE_TYPE_DROP;
1956 memcg = __mem_cgroup_uncharge_common(page, ctype);
1958 /* record memcg information */
1959 if (do_swap_account && swapout && memcg) {
1960 swap_cgroup_record(ent, css_id(&memcg->css));
1961 mem_cgroup_get(memcg);
1963 if (swapout && memcg)
1964 css_put(&memcg->css);
1968 #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP
1970 * called from swap_entry_free(). remove record in swap_cgroup and
1971 * uncharge "memsw" account.
1973 void mem_cgroup_uncharge_swap(swp_entry_t ent)
1975 struct mem_cgroup *memcg;
1978 if (!do_swap_account)
1981 id = swap_cgroup_record(ent, 0);
1983 memcg = mem_cgroup_lookup(id);
1986 * We uncharge this because swap is freed.
1987 * This memcg can be obsolete one. We avoid calling css_tryget
1989 if (!mem_cgroup_is_root(memcg))
1990 res_counter_uncharge(&memcg->memsw, PAGE_SIZE, NULL);
1991 mem_cgroup_swap_statistics(memcg, false);
1992 mem_cgroup_put(memcg);
1999 * Before starting migration, account PAGE_SIZE to mem_cgroup that the old
2002 int mem_cgroup_prepare_migration(struct page *page, struct mem_cgroup **ptr)
2004 struct page_cgroup *pc;
2005 struct mem_cgroup *mem = NULL;
2008 if (mem_cgroup_disabled())
2011 pc = lookup_page_cgroup(page);
2012 lock_page_cgroup(pc);
2013 if (PageCgroupUsed(pc)) {
2014 mem = pc->mem_cgroup;
2017 unlock_page_cgroup(pc);
2020 ret = __mem_cgroup_try_charge(NULL, GFP_KERNEL, &mem, false,
2028 /* remove redundant charge if migration failed*/
2029 void mem_cgroup_end_migration(struct mem_cgroup *mem,
2030 struct page *oldpage, struct page *newpage)
2032 struct page *target, *unused;
2033 struct page_cgroup *pc;
2034 enum charge_type ctype;
2038 cgroup_exclude_rmdir(&mem->css);
2039 /* at migration success, oldpage->mapping is NULL. */
2040 if (oldpage->mapping) {
2048 if (PageAnon(target))
2049 ctype = MEM_CGROUP_CHARGE_TYPE_MAPPED;
2050 else if (page_is_file_cache(target))
2051 ctype = MEM_CGROUP_CHARGE_TYPE_CACHE;
2053 ctype = MEM_CGROUP_CHARGE_TYPE_SHMEM;
2055 /* unused page is not on radix-tree now. */
2057 __mem_cgroup_uncharge_common(unused, ctype);
2059 pc = lookup_page_cgroup(target);
2061 * __mem_cgroup_commit_charge() check PCG_USED bit of page_cgroup.
2062 * So, double-counting is effectively avoided.
2064 __mem_cgroup_commit_charge(mem, pc, ctype);
2067 * Both of oldpage and newpage are still under lock_page().
2068 * Then, we don't have to care about race in radix-tree.
2069 * But we have to be careful that this page is unmapped or not.
2071 * There is a case for !page_mapped(). At the start of
2072 * migration, oldpage was mapped. But now, it's zapped.
2073 * But we know *target* page is not freed/reused under us.
2074 * mem_cgroup_uncharge_page() does all necessary checks.
2076 if (ctype == MEM_CGROUP_CHARGE_TYPE_MAPPED)
2077 mem_cgroup_uncharge_page(target);
2079 * At migration, we may charge account against cgroup which has no tasks
2080 * So, rmdir()->pre_destroy() can be called while we do this charge.
2081 * In that case, we need to call pre_destroy() again. check it here.
2083 cgroup_release_and_wakeup_rmdir(&mem->css);
2087 * A call to try to shrink memory usage on charge failure at shmem's swapin.
2088 * Calling hierarchical_reclaim is not enough because we should update
2089 * last_oom_jiffies to prevent pagefault_out_of_memory from invoking global OOM.
2090 * Moreover considering hierarchy, we should reclaim from the mem_over_limit,
2091 * not from the memcg which this page would be charged to.
2092 * try_charge_swapin does all of these works properly.
2094 int mem_cgroup_shmem_charge_fallback(struct page *page,
2095 struct mm_struct *mm,
2098 struct mem_cgroup *mem = NULL;
2101 if (mem_cgroup_disabled())
2104 ret = mem_cgroup_try_charge_swapin(mm, page, gfp_mask, &mem);
2106 mem_cgroup_cancel_charge_swapin(mem); /* it does !mem check */
2111 static DEFINE_MUTEX(set_limit_mutex);
2113 static int mem_cgroup_resize_limit(struct mem_cgroup *memcg,
2114 unsigned long long val)
2120 int children = mem_cgroup_count_children(memcg);
2121 u64 curusage, oldusage;
2124 * For keeping hierarchical_reclaim simple, how long we should retry
2125 * is depends on callers. We set our retry-count to be function
2126 * of # of children which we should visit in this loop.
2128 retry_count = MEM_CGROUP_RECLAIM_RETRIES * children;
2130 oldusage = res_counter_read_u64(&memcg->res, RES_USAGE);
2132 while (retry_count) {
2133 if (signal_pending(current)) {
2138 * Rather than hide all in some function, I do this in
2139 * open coded manner. You see what this really does.
2140 * We have to guarantee mem->res.limit < mem->memsw.limit.
2142 mutex_lock(&set_limit_mutex);
2143 memswlimit = res_counter_read_u64(&memcg->memsw, RES_LIMIT);
2144 if (memswlimit < val) {
2146 mutex_unlock(&set_limit_mutex);
2149 ret = res_counter_set_limit(&memcg->res, val);
2151 if (memswlimit == val)
2152 memcg->memsw_is_minimum = true;
2154 memcg->memsw_is_minimum = false;
2156 mutex_unlock(&set_limit_mutex);
2161 progress = mem_cgroup_hierarchical_reclaim(memcg, NULL,
2163 MEM_CGROUP_RECLAIM_SHRINK);
2164 curusage = res_counter_read_u64(&memcg->res, RES_USAGE);
2165 /* Usage is reduced ? */
2166 if (curusage >= oldusage)
2169 oldusage = curusage;
2175 static int mem_cgroup_resize_memsw_limit(struct mem_cgroup *memcg,
2176 unsigned long long val)
2179 u64 memlimit, oldusage, curusage;
2180 int children = mem_cgroup_count_children(memcg);
2183 /* see mem_cgroup_resize_res_limit */
2184 retry_count = children * MEM_CGROUP_RECLAIM_RETRIES;
2185 oldusage = res_counter_read_u64(&memcg->memsw, RES_USAGE);
2186 while (retry_count) {
2187 if (signal_pending(current)) {
2192 * Rather than hide all in some function, I do this in
2193 * open coded manner. You see what this really does.
2194 * We have to guarantee mem->res.limit < mem->memsw.limit.
2196 mutex_lock(&set_limit_mutex);
2197 memlimit = res_counter_read_u64(&memcg->res, RES_LIMIT);
2198 if (memlimit > val) {
2200 mutex_unlock(&set_limit_mutex);
2203 ret = res_counter_set_limit(&memcg->memsw, val);
2205 if (memlimit == val)
2206 memcg->memsw_is_minimum = true;
2208 memcg->memsw_is_minimum = false;
2210 mutex_unlock(&set_limit_mutex);
2215 mem_cgroup_hierarchical_reclaim(memcg, NULL, GFP_KERNEL,
2216 MEM_CGROUP_RECLAIM_NOSWAP |
2217 MEM_CGROUP_RECLAIM_SHRINK);
2218 curusage = res_counter_read_u64(&memcg->memsw, RES_USAGE);
2219 /* Usage is reduced ? */
2220 if (curusage >= oldusage)
2223 oldusage = curusage;
2228 unsigned long mem_cgroup_soft_limit_reclaim(struct zone *zone, int order,
2229 gfp_t gfp_mask, int nid,
2232 unsigned long nr_reclaimed = 0;
2233 struct mem_cgroup_per_zone *mz, *next_mz = NULL;
2234 unsigned long reclaimed;
2236 struct mem_cgroup_tree_per_zone *mctz;
2241 mctz = soft_limit_tree_node_zone(nid, zid);
2243 * This loop can run a while, specially if mem_cgroup's continuously
2244 * keep exceeding their soft limit and putting the system under
2251 mz = mem_cgroup_largest_soft_limit_node(mctz);
2255 reclaimed = mem_cgroup_hierarchical_reclaim(mz->mem, zone,
2257 MEM_CGROUP_RECLAIM_SOFT);
2258 nr_reclaimed += reclaimed;
2259 spin_lock(&mctz->lock);
2262 * If we failed to reclaim anything from this memory cgroup
2263 * it is time to move on to the next cgroup
2269 * Loop until we find yet another one.
2271 * By the time we get the soft_limit lock
2272 * again, someone might have aded the
2273 * group back on the RB tree. Iterate to
2274 * make sure we get a different mem.
2275 * mem_cgroup_largest_soft_limit_node returns
2276 * NULL if no other cgroup is present on
2280 __mem_cgroup_largest_soft_limit_node(mctz);
2281 if (next_mz == mz) {
2282 css_put(&next_mz->mem->css);
2284 } else /* next_mz == NULL or other memcg */
2288 mz->usage_in_excess =
2289 res_counter_soft_limit_excess(&mz->mem->res);
2290 __mem_cgroup_remove_exceeded(mz->mem, mz, mctz);
2292 * One school of thought says that we should not add
2293 * back the node to the tree if reclaim returns 0.
2294 * But our reclaim could return 0, simply because due
2295 * to priority we are exposing a smaller subset of
2296 * memory to reclaim from. Consider this as a longer
2299 if (mz->usage_in_excess)
2300 __mem_cgroup_insert_exceeded(mz->mem, mz, mctz);
2301 spin_unlock(&mctz->lock);
2302 css_put(&mz->mem->css);
2305 * Could not reclaim anything and there are no more
2306 * mem cgroups to try or we seem to be looping without
2307 * reclaiming anything.
2309 if (!nr_reclaimed &&
2311 loop > MEM_CGROUP_MAX_SOFT_LIMIT_RECLAIM_LOOPS))
2313 } while (!nr_reclaimed);
2315 css_put(&next_mz->mem->css);
2316 return nr_reclaimed;
2320 * This routine traverse page_cgroup in given list and drop them all.
2321 * *And* this routine doesn't reclaim page itself, just removes page_cgroup.
2323 static int mem_cgroup_force_empty_list(struct mem_cgroup *mem,
2324 int node, int zid, enum lru_list lru)
2327 struct mem_cgroup_per_zone *mz;
2328 struct page_cgroup *pc, *busy;
2329 unsigned long flags, loop;
2330 struct list_head *list;
2333 zone = &NODE_DATA(node)->node_zones[zid];
2334 mz = mem_cgroup_zoneinfo(mem, node, zid);
2335 list = &mz->lists[lru];
2337 loop = MEM_CGROUP_ZSTAT(mz, lru);
2338 /* give some margin against EBUSY etc...*/
2343 spin_lock_irqsave(&zone->lru_lock, flags);
2344 if (list_empty(list)) {
2345 spin_unlock_irqrestore(&zone->lru_lock, flags);
2348 pc = list_entry(list->prev, struct page_cgroup, lru);
2350 list_move(&pc->lru, list);
2352 spin_unlock_irqrestore(&zone->lru_lock, flags);
2355 spin_unlock_irqrestore(&zone->lru_lock, flags);
2357 ret = mem_cgroup_move_parent(pc, mem, GFP_KERNEL);
2361 if (ret == -EBUSY || ret == -EINVAL) {
2362 /* found lock contention or "pc" is obsolete. */
2369 if (!ret && !list_empty(list))
2375 * make mem_cgroup's charge to be 0 if there is no task.
2376 * This enables deleting this mem_cgroup.
2378 static int mem_cgroup_force_empty(struct mem_cgroup *mem, bool free_all)
2381 int node, zid, shrink;
2382 int nr_retries = MEM_CGROUP_RECLAIM_RETRIES;
2383 struct cgroup *cgrp = mem->css.cgroup;
2388 /* should free all ? */
2392 while (mem->res.usage > 0) {
2394 if (cgroup_task_count(cgrp) || !list_empty(&cgrp->children))
2397 if (signal_pending(current))
2399 /* This is for making all *used* pages to be on LRU. */
2400 lru_add_drain_all();
2402 for_each_node_state(node, N_HIGH_MEMORY) {
2403 for (zid = 0; !ret && zid < MAX_NR_ZONES; zid++) {
2406 ret = mem_cgroup_force_empty_list(mem,
2415 /* it seems parent cgroup doesn't have enough mem */
2426 /* returns EBUSY if there is a task or if we come here twice. */
2427 if (cgroup_task_count(cgrp) || !list_empty(&cgrp->children) || shrink) {
2431 /* we call try-to-free pages for make this cgroup empty */
2432 lru_add_drain_all();
2433 /* try to free all pages in this cgroup */
2435 while (nr_retries && mem->res.usage > 0) {
2438 if (signal_pending(current)) {
2442 progress = try_to_free_mem_cgroup_pages(mem, GFP_KERNEL,
2443 false, get_swappiness(mem));
2446 /* maybe some writeback is necessary */
2447 congestion_wait(BLK_RW_ASYNC, HZ/10);
2452 /* try move_account...there may be some *locked* pages. */
2459 int mem_cgroup_force_empty_write(struct cgroup *cont, unsigned int event)
2461 return mem_cgroup_force_empty(mem_cgroup_from_cont(cont), true);
2465 static u64 mem_cgroup_hierarchy_read(struct cgroup *cont, struct cftype *cft)
2467 return mem_cgroup_from_cont(cont)->use_hierarchy;
2470 static int mem_cgroup_hierarchy_write(struct cgroup *cont, struct cftype *cft,
2474 struct mem_cgroup *mem = mem_cgroup_from_cont(cont);
2475 struct cgroup *parent = cont->parent;
2476 struct mem_cgroup *parent_mem = NULL;
2479 parent_mem = mem_cgroup_from_cont(parent);
2483 * If parent's use_hiearchy is set, we can't make any modifications
2484 * in the child subtrees. If it is unset, then the change can
2485 * occur, provided the current cgroup has no children.
2487 * For the root cgroup, parent_mem is NULL, we allow value to be
2488 * set if there are no children.
2490 if ((!parent_mem || !parent_mem->use_hierarchy) &&
2491 (val == 1 || val == 0)) {
2492 if (list_empty(&cont->children))
2493 mem->use_hierarchy = val;
2503 struct mem_cgroup_idx_data {
2505 enum mem_cgroup_stat_index idx;
2509 mem_cgroup_get_idx_stat(struct mem_cgroup *mem, void *data)
2511 struct mem_cgroup_idx_data *d = data;
2512 d->val += mem_cgroup_read_stat(&mem->stat, d->idx);
2517 mem_cgroup_get_recursive_idx_stat(struct mem_cgroup *mem,
2518 enum mem_cgroup_stat_index idx, s64 *val)
2520 struct mem_cgroup_idx_data d;
2523 mem_cgroup_walk_tree(mem, &d, mem_cgroup_get_idx_stat);
2527 static u64 mem_cgroup_read(struct cgroup *cont, struct cftype *cft)
2529 struct mem_cgroup *mem = mem_cgroup_from_cont(cont);
2533 type = MEMFILE_TYPE(cft->private);
2534 name = MEMFILE_ATTR(cft->private);
2537 if (name == RES_USAGE && mem_cgroup_is_root(mem)) {
2538 mem_cgroup_get_recursive_idx_stat(mem,
2539 MEM_CGROUP_STAT_CACHE, &idx_val);
2541 mem_cgroup_get_recursive_idx_stat(mem,
2542 MEM_CGROUP_STAT_RSS, &idx_val);
2546 val = res_counter_read_u64(&mem->res, name);
2549 if (name == RES_USAGE && mem_cgroup_is_root(mem)) {
2550 mem_cgroup_get_recursive_idx_stat(mem,
2551 MEM_CGROUP_STAT_CACHE, &idx_val);
2553 mem_cgroup_get_recursive_idx_stat(mem,
2554 MEM_CGROUP_STAT_RSS, &idx_val);
2556 mem_cgroup_get_recursive_idx_stat(mem,
2557 MEM_CGROUP_STAT_SWAPOUT, &idx_val);
2560 val = res_counter_read_u64(&mem->memsw, name);
2569 * The user of this function is...
2572 static int mem_cgroup_write(struct cgroup *cont, struct cftype *cft,
2575 struct mem_cgroup *memcg = mem_cgroup_from_cont(cont);
2577 unsigned long long val;
2580 type = MEMFILE_TYPE(cft->private);
2581 name = MEMFILE_ATTR(cft->private);
2584 if (mem_cgroup_is_root(memcg)) { /* Can't set limit on root */
2588 /* This function does all necessary parse...reuse it */
2589 ret = res_counter_memparse_write_strategy(buffer, &val);
2593 ret = mem_cgroup_resize_limit(memcg, val);
2595 ret = mem_cgroup_resize_memsw_limit(memcg, val);
2597 case RES_SOFT_LIMIT:
2598 ret = res_counter_memparse_write_strategy(buffer, &val);
2602 * For memsw, soft limits are hard to implement in terms
2603 * of semantics, for now, we support soft limits for
2604 * control without swap
2607 ret = res_counter_set_soft_limit(&memcg->res, val);
2612 ret = -EINVAL; /* should be BUG() ? */
2618 static void memcg_get_hierarchical_limit(struct mem_cgroup *memcg,
2619 unsigned long long *mem_limit, unsigned long long *memsw_limit)
2621 struct cgroup *cgroup;
2622 unsigned long long min_limit, min_memsw_limit, tmp;
2624 min_limit = res_counter_read_u64(&memcg->res, RES_LIMIT);
2625 min_memsw_limit = res_counter_read_u64(&memcg->memsw, RES_LIMIT);
2626 cgroup = memcg->css.cgroup;
2627 if (!memcg->use_hierarchy)
2630 while (cgroup->parent) {
2631 cgroup = cgroup->parent;
2632 memcg = mem_cgroup_from_cont(cgroup);
2633 if (!memcg->use_hierarchy)
2635 tmp = res_counter_read_u64(&memcg->res, RES_LIMIT);
2636 min_limit = min(min_limit, tmp);
2637 tmp = res_counter_read_u64(&memcg->memsw, RES_LIMIT);
2638 min_memsw_limit = min(min_memsw_limit, tmp);
2641 *mem_limit = min_limit;
2642 *memsw_limit = min_memsw_limit;
2646 static int mem_cgroup_reset(struct cgroup *cont, unsigned int event)
2648 struct mem_cgroup *mem;
2651 mem = mem_cgroup_from_cont(cont);
2652 type = MEMFILE_TYPE(event);
2653 name = MEMFILE_ATTR(event);
2657 res_counter_reset_max(&mem->res);
2659 res_counter_reset_max(&mem->memsw);
2663 res_counter_reset_failcnt(&mem->res);
2665 res_counter_reset_failcnt(&mem->memsw);
2673 /* For read statistics */
2689 struct mcs_total_stat {
2690 s64 stat[NR_MCS_STAT];
2696 } memcg_stat_strings[NR_MCS_STAT] = {
2697 {"cache", "total_cache"},
2698 {"rss", "total_rss"},
2699 {"mapped_file", "total_mapped_file"},
2700 {"pgpgin", "total_pgpgin"},
2701 {"pgpgout", "total_pgpgout"},
2702 {"swap", "total_swap"},
2703 {"inactive_anon", "total_inactive_anon"},
2704 {"active_anon", "total_active_anon"},
2705 {"inactive_file", "total_inactive_file"},
2706 {"active_file", "total_active_file"},
2707 {"unevictable", "total_unevictable"}
2711 static int mem_cgroup_get_local_stat(struct mem_cgroup *mem, void *data)
2713 struct mcs_total_stat *s = data;
2717 val = mem_cgroup_read_stat(&mem->stat, MEM_CGROUP_STAT_CACHE);
2718 s->stat[MCS_CACHE] += val * PAGE_SIZE;
2719 val = mem_cgroup_read_stat(&mem->stat, MEM_CGROUP_STAT_RSS);
2720 s->stat[MCS_RSS] += val * PAGE_SIZE;
2721 val = mem_cgroup_read_stat(&mem->stat, MEM_CGROUP_STAT_MAPPED_FILE);
2722 s->stat[MCS_MAPPED_FILE] += val * PAGE_SIZE;
2723 val = mem_cgroup_read_stat(&mem->stat, MEM_CGROUP_STAT_PGPGIN_COUNT);
2724 s->stat[MCS_PGPGIN] += val;
2725 val = mem_cgroup_read_stat(&mem->stat, MEM_CGROUP_STAT_PGPGOUT_COUNT);
2726 s->stat[MCS_PGPGOUT] += val;
2727 if (do_swap_account) {
2728 val = mem_cgroup_read_stat(&mem->stat, MEM_CGROUP_STAT_SWAPOUT);
2729 s->stat[MCS_SWAP] += val * PAGE_SIZE;
2733 val = mem_cgroup_get_local_zonestat(mem, LRU_INACTIVE_ANON);
2734 s->stat[MCS_INACTIVE_ANON] += val * PAGE_SIZE;
2735 val = mem_cgroup_get_local_zonestat(mem, LRU_ACTIVE_ANON);
2736 s->stat[MCS_ACTIVE_ANON] += val * PAGE_SIZE;
2737 val = mem_cgroup_get_local_zonestat(mem, LRU_INACTIVE_FILE);
2738 s->stat[MCS_INACTIVE_FILE] += val * PAGE_SIZE;
2739 val = mem_cgroup_get_local_zonestat(mem, LRU_ACTIVE_FILE);
2740 s->stat[MCS_ACTIVE_FILE] += val * PAGE_SIZE;
2741 val = mem_cgroup_get_local_zonestat(mem, LRU_UNEVICTABLE);
2742 s->stat[MCS_UNEVICTABLE] += val * PAGE_SIZE;
2747 mem_cgroup_get_total_stat(struct mem_cgroup *mem, struct mcs_total_stat *s)
2749 mem_cgroup_walk_tree(mem, s, mem_cgroup_get_local_stat);
2752 static int mem_control_stat_show(struct cgroup *cont, struct cftype *cft,
2753 struct cgroup_map_cb *cb)
2755 struct mem_cgroup *mem_cont = mem_cgroup_from_cont(cont);
2756 struct mcs_total_stat mystat;
2759 memset(&mystat, 0, sizeof(mystat));
2760 mem_cgroup_get_local_stat(mem_cont, &mystat);
2762 for (i = 0; i < NR_MCS_STAT; i++) {
2763 if (i == MCS_SWAP && !do_swap_account)
2765 cb->fill(cb, memcg_stat_strings[i].local_name, mystat.stat[i]);
2768 /* Hierarchical information */
2770 unsigned long long limit, memsw_limit;
2771 memcg_get_hierarchical_limit(mem_cont, &limit, &memsw_limit);
2772 cb->fill(cb, "hierarchical_memory_limit", limit);
2773 if (do_swap_account)
2774 cb->fill(cb, "hierarchical_memsw_limit", memsw_limit);
2777 memset(&mystat, 0, sizeof(mystat));
2778 mem_cgroup_get_total_stat(mem_cont, &mystat);
2779 for (i = 0; i < NR_MCS_STAT; i++) {
2780 if (i == MCS_SWAP && !do_swap_account)
2782 cb->fill(cb, memcg_stat_strings[i].total_name, mystat.stat[i]);
2785 #ifdef CONFIG_DEBUG_VM
2786 cb->fill(cb, "inactive_ratio", calc_inactive_ratio(mem_cont, NULL));
2790 struct mem_cgroup_per_zone *mz;
2791 unsigned long recent_rotated[2] = {0, 0};
2792 unsigned long recent_scanned[2] = {0, 0};
2794 for_each_online_node(nid)
2795 for (zid = 0; zid < MAX_NR_ZONES; zid++) {
2796 mz = mem_cgroup_zoneinfo(mem_cont, nid, zid);
2798 recent_rotated[0] +=
2799 mz->reclaim_stat.recent_rotated[0];
2800 recent_rotated[1] +=
2801 mz->reclaim_stat.recent_rotated[1];
2802 recent_scanned[0] +=
2803 mz->reclaim_stat.recent_scanned[0];
2804 recent_scanned[1] +=
2805 mz->reclaim_stat.recent_scanned[1];
2807 cb->fill(cb, "recent_rotated_anon", recent_rotated[0]);
2808 cb->fill(cb, "recent_rotated_file", recent_rotated[1]);
2809 cb->fill(cb, "recent_scanned_anon", recent_scanned[0]);
2810 cb->fill(cb, "recent_scanned_file", recent_scanned[1]);
2817 static u64 mem_cgroup_swappiness_read(struct cgroup *cgrp, struct cftype *cft)
2819 struct mem_cgroup *memcg = mem_cgroup_from_cont(cgrp);
2821 return get_swappiness(memcg);
2824 static int mem_cgroup_swappiness_write(struct cgroup *cgrp, struct cftype *cft,
2827 struct mem_cgroup *memcg = mem_cgroup_from_cont(cgrp);
2828 struct mem_cgroup *parent;
2833 if (cgrp->parent == NULL)
2836 parent = mem_cgroup_from_cont(cgrp->parent);
2840 /* If under hierarchy, only empty-root can set this value */
2841 if ((parent->use_hierarchy) ||
2842 (memcg->use_hierarchy && !list_empty(&cgrp->children))) {
2847 spin_lock(&memcg->reclaim_param_lock);
2848 memcg->swappiness = val;
2849 spin_unlock(&memcg->reclaim_param_lock);
2857 static struct cftype mem_cgroup_files[] = {
2859 .name = "usage_in_bytes",
2860 .private = MEMFILE_PRIVATE(_MEM, RES_USAGE),
2861 .read_u64 = mem_cgroup_read,
2864 .name = "max_usage_in_bytes",
2865 .private = MEMFILE_PRIVATE(_MEM, RES_MAX_USAGE),
2866 .trigger = mem_cgroup_reset,
2867 .read_u64 = mem_cgroup_read,
2870 .name = "limit_in_bytes",
2871 .private = MEMFILE_PRIVATE(_MEM, RES_LIMIT),
2872 .write_string = mem_cgroup_write,
2873 .read_u64 = mem_cgroup_read,
2876 .name = "soft_limit_in_bytes",
2877 .private = MEMFILE_PRIVATE(_MEM, RES_SOFT_LIMIT),
2878 .write_string = mem_cgroup_write,
2879 .read_u64 = mem_cgroup_read,
2883 .private = MEMFILE_PRIVATE(_MEM, RES_FAILCNT),
2884 .trigger = mem_cgroup_reset,
2885 .read_u64 = mem_cgroup_read,
2889 .read_map = mem_control_stat_show,
2892 .name = "force_empty",
2893 .trigger = mem_cgroup_force_empty_write,
2896 .name = "use_hierarchy",
2897 .write_u64 = mem_cgroup_hierarchy_write,
2898 .read_u64 = mem_cgroup_hierarchy_read,
2901 .name = "swappiness",
2902 .read_u64 = mem_cgroup_swappiness_read,
2903 .write_u64 = mem_cgroup_swappiness_write,
2907 #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP
2908 static struct cftype memsw_cgroup_files[] = {
2910 .name = "memsw.usage_in_bytes",
2911 .private = MEMFILE_PRIVATE(_MEMSWAP, RES_USAGE),
2912 .read_u64 = mem_cgroup_read,
2915 .name = "memsw.max_usage_in_bytes",
2916 .private = MEMFILE_PRIVATE(_MEMSWAP, RES_MAX_USAGE),
2917 .trigger = mem_cgroup_reset,
2918 .read_u64 = mem_cgroup_read,
2921 .name = "memsw.limit_in_bytes",
2922 .private = MEMFILE_PRIVATE(_MEMSWAP, RES_LIMIT),
2923 .write_string = mem_cgroup_write,
2924 .read_u64 = mem_cgroup_read,
2927 .name = "memsw.failcnt",
2928 .private = MEMFILE_PRIVATE(_MEMSWAP, RES_FAILCNT),
2929 .trigger = mem_cgroup_reset,
2930 .read_u64 = mem_cgroup_read,
2934 static int register_memsw_files(struct cgroup *cont, struct cgroup_subsys *ss)
2936 if (!do_swap_account)
2938 return cgroup_add_files(cont, ss, memsw_cgroup_files,
2939 ARRAY_SIZE(memsw_cgroup_files));
2942 static int register_memsw_files(struct cgroup *cont, struct cgroup_subsys *ss)
2948 static int alloc_mem_cgroup_per_zone_info(struct mem_cgroup *mem, int node)
2950 struct mem_cgroup_per_node *pn;
2951 struct mem_cgroup_per_zone *mz;
2953 int zone, tmp = node;
2955 * This routine is called against possible nodes.
2956 * But it's BUG to call kmalloc() against offline node.
2958 * TODO: this routine can waste much memory for nodes which will
2959 * never be onlined. It's better to use memory hotplug callback
2962 if (!node_state(node, N_NORMAL_MEMORY))
2964 pn = kmalloc_node(sizeof(*pn), GFP_KERNEL, tmp);
2968 mem->info.nodeinfo[node] = pn;
2969 memset(pn, 0, sizeof(*pn));
2971 for (zone = 0; zone < MAX_NR_ZONES; zone++) {
2972 mz = &pn->zoneinfo[zone];
2974 INIT_LIST_HEAD(&mz->lists[l]);
2975 mz->usage_in_excess = 0;
2976 mz->on_tree = false;
2982 static void free_mem_cgroup_per_zone_info(struct mem_cgroup *mem, int node)
2984 kfree(mem->info.nodeinfo[node]);
2987 static int mem_cgroup_size(void)
2989 int cpustat_size = nr_cpu_ids * sizeof(struct mem_cgroup_stat_cpu);
2990 return sizeof(struct mem_cgroup) + cpustat_size;
2993 static struct mem_cgroup *mem_cgroup_alloc(void)
2995 struct mem_cgroup *mem;
2996 int size = mem_cgroup_size();
2998 if (size < PAGE_SIZE)
2999 mem = kmalloc(size, GFP_KERNEL);
3001 mem = vmalloc(size);
3004 memset(mem, 0, size);
3009 * At destroying mem_cgroup, references from swap_cgroup can remain.
3010 * (scanning all at force_empty is too costly...)
3012 * Instead of clearing all references at force_empty, we remember
3013 * the number of reference from swap_cgroup and free mem_cgroup when
3014 * it goes down to 0.
3016 * Removal of cgroup itself succeeds regardless of refs from swap.
3019 static void __mem_cgroup_free(struct mem_cgroup *mem)
3023 mem_cgroup_remove_from_trees(mem);
3024 free_css_id(&mem_cgroup_subsys, &mem->css);
3026 for_each_node_state(node, N_POSSIBLE)
3027 free_mem_cgroup_per_zone_info(mem, node);
3029 if (mem_cgroup_size() < PAGE_SIZE)
3035 static void mem_cgroup_get(struct mem_cgroup *mem)
3037 atomic_inc(&mem->refcnt);
3040 static void mem_cgroup_put(struct mem_cgroup *mem)
3042 if (atomic_dec_and_test(&mem->refcnt)) {
3043 struct mem_cgroup *parent = parent_mem_cgroup(mem);
3044 __mem_cgroup_free(mem);
3046 mem_cgroup_put(parent);
3051 * Returns the parent mem_cgroup in memcgroup hierarchy with hierarchy enabled.
3053 static struct mem_cgroup *parent_mem_cgroup(struct mem_cgroup *mem)
3055 if (!mem->res.parent)
3057 return mem_cgroup_from_res_counter(mem->res.parent, res);
3060 #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP
3061 static void __init enable_swap_cgroup(void)
3063 if (!mem_cgroup_disabled() && really_do_swap_account)
3064 do_swap_account = 1;
3067 static void __init enable_swap_cgroup(void)
3072 static int mem_cgroup_soft_limit_tree_init(void)
3074 struct mem_cgroup_tree_per_node *rtpn;
3075 struct mem_cgroup_tree_per_zone *rtpz;
3076 int tmp, node, zone;
3078 for_each_node_state(node, N_POSSIBLE) {
3080 if (!node_state(node, N_NORMAL_MEMORY))
3082 rtpn = kzalloc_node(sizeof(*rtpn), GFP_KERNEL, tmp);
3086 soft_limit_tree.rb_tree_per_node[node] = rtpn;
3088 for (zone = 0; zone < MAX_NR_ZONES; zone++) {
3089 rtpz = &rtpn->rb_tree_per_zone[zone];
3090 rtpz->rb_root = RB_ROOT;
3091 spin_lock_init(&rtpz->lock);
3097 static struct cgroup_subsys_state * __ref
3098 mem_cgroup_create(struct cgroup_subsys *ss, struct cgroup *cont)
3100 struct mem_cgroup *mem, *parent;
3101 long error = -ENOMEM;
3104 mem = mem_cgroup_alloc();
3106 return ERR_PTR(error);
3108 for_each_node_state(node, N_POSSIBLE)
3109 if (alloc_mem_cgroup_per_zone_info(mem, node))
3113 if (cont->parent == NULL) {
3114 enable_swap_cgroup();
3116 root_mem_cgroup = mem;
3117 if (mem_cgroup_soft_limit_tree_init())
3121 parent = mem_cgroup_from_cont(cont->parent);
3122 mem->use_hierarchy = parent->use_hierarchy;
3125 if (parent && parent->use_hierarchy) {
3126 res_counter_init(&mem->res, &parent->res);
3127 res_counter_init(&mem->memsw, &parent->memsw);
3129 * We increment refcnt of the parent to ensure that we can
3130 * safely access it on res_counter_charge/uncharge.
3131 * This refcnt will be decremented when freeing this
3132 * mem_cgroup(see mem_cgroup_put).
3134 mem_cgroup_get(parent);
3136 res_counter_init(&mem->res, NULL);
3137 res_counter_init(&mem->memsw, NULL);
3139 mem->last_scanned_child = 0;
3140 spin_lock_init(&mem->reclaim_param_lock);
3143 mem->swappiness = get_swappiness(parent);
3144 atomic_set(&mem->refcnt, 1);
3147 __mem_cgroup_free(mem);
3148 root_mem_cgroup = NULL;
3149 return ERR_PTR(error);
3152 static int mem_cgroup_pre_destroy(struct cgroup_subsys *ss,
3153 struct cgroup *cont)
3155 struct mem_cgroup *mem = mem_cgroup_from_cont(cont);
3157 return mem_cgroup_force_empty(mem, false);
3160 static void mem_cgroup_destroy(struct cgroup_subsys *ss,
3161 struct cgroup *cont)
3163 struct mem_cgroup *mem = mem_cgroup_from_cont(cont);
3165 mem_cgroup_put(mem);
3168 static int mem_cgroup_populate(struct cgroup_subsys *ss,
3169 struct cgroup *cont)
3173 ret = cgroup_add_files(cont, ss, mem_cgroup_files,
3174 ARRAY_SIZE(mem_cgroup_files));
3177 ret = register_memsw_files(cont, ss);
3181 static void mem_cgroup_move_task(struct cgroup_subsys *ss,
3182 struct cgroup *cont,
3183 struct cgroup *old_cont,
3184 struct task_struct *p,
3187 mutex_lock(&memcg_tasklist);
3189 * FIXME: It's better to move charges of this process from old
3190 * memcg to new memcg. But it's just on TODO-List now.
3192 mutex_unlock(&memcg_tasklist);
3195 struct cgroup_subsys mem_cgroup_subsys = {
3197 .subsys_id = mem_cgroup_subsys_id,
3198 .create = mem_cgroup_create,
3199 .pre_destroy = mem_cgroup_pre_destroy,
3200 .destroy = mem_cgroup_destroy,
3201 .populate = mem_cgroup_populate,
3202 .attach = mem_cgroup_move_task,
3207 #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP
3209 static int __init disable_swap_account(char *s)
3211 really_do_swap_account = 0;
3214 __setup("noswapaccount", disable_swap_account);