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/mutex.h>
31 #include <linux/slab.h>
32 #include <linux/swap.h>
33 #include <linux/spinlock.h>
35 #include <linux/seq_file.h>
36 #include <linux/vmalloc.h>
37 #include <linux/mm_inline.h>
38 #include <linux/page_cgroup.h>
41 #include <asm/uaccess.h>
43 struct cgroup_subsys mem_cgroup_subsys __read_mostly;
44 #define MEM_CGROUP_RECLAIM_RETRIES 5
46 #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP
47 /* Turned on only when memory cgroup is enabled && really_do_swap_account = 0 */
48 int do_swap_account __read_mostly;
49 static int really_do_swap_account __initdata = 1; /* for remember boot option*/
51 #define do_swap_account (0)
56 * Statistics for memory cgroup.
58 enum mem_cgroup_stat_index {
60 * For MEM_CONTAINER_TYPE_ALL, usage = pagecache + rss.
62 MEM_CGROUP_STAT_CACHE, /* # of pages charged as cache */
63 MEM_CGROUP_STAT_RSS, /* # of pages charged as rss */
64 MEM_CGROUP_STAT_PGPGIN_COUNT, /* # of pages paged in */
65 MEM_CGROUP_STAT_PGPGOUT_COUNT, /* # of pages paged out */
67 MEM_CGROUP_STAT_NSTATS,
70 struct mem_cgroup_stat_cpu {
71 s64 count[MEM_CGROUP_STAT_NSTATS];
72 } ____cacheline_aligned_in_smp;
74 struct mem_cgroup_stat {
75 struct mem_cgroup_stat_cpu cpustat[0];
79 * For accounting under irq disable, no need for increment preempt count.
81 static inline void __mem_cgroup_stat_add_safe(struct mem_cgroup_stat_cpu *stat,
82 enum mem_cgroup_stat_index idx, int val)
84 stat->count[idx] += val;
87 static s64 mem_cgroup_read_stat(struct mem_cgroup_stat *stat,
88 enum mem_cgroup_stat_index idx)
92 for_each_possible_cpu(cpu)
93 ret += stat->cpustat[cpu].count[idx];
98 * per-zone information in memory controller.
100 struct mem_cgroup_per_zone {
102 * spin_lock to protect the per cgroup LRU
104 struct list_head lists[NR_LRU_LISTS];
105 unsigned long count[NR_LRU_LISTS];
107 /* Macro for accessing counter */
108 #define MEM_CGROUP_ZSTAT(mz, idx) ((mz)->count[(idx)])
110 struct mem_cgroup_per_node {
111 struct mem_cgroup_per_zone zoneinfo[MAX_NR_ZONES];
114 struct mem_cgroup_lru_info {
115 struct mem_cgroup_per_node *nodeinfo[MAX_NUMNODES];
119 * The memory controller data structure. The memory controller controls both
120 * page cache and RSS per cgroup. We would eventually like to provide
121 * statistics based on the statistics developed by Rik Van Riel for clock-pro,
122 * to help the administrator determine what knobs to tune.
124 * TODO: Add a water mark for the memory controller. Reclaim will begin when
125 * we hit the water mark. May be even add a low water mark, such that
126 * no reclaim occurs from a cgroup at it's low water mark, this is
127 * a feature that will be implemented much later in the future.
130 struct cgroup_subsys_state css;
132 * the counter to account for memory usage
134 struct res_counter res;
136 * the counter to account for mem+swap usage.
138 struct res_counter memsw;
140 * Per cgroup active and inactive list, similar to the
141 * per zone LRU lists.
143 struct mem_cgroup_lru_info info;
145 int prev_priority; /* for recording reclaim priority */
148 * While reclaiming in a hiearchy, we cache the last child we
149 * reclaimed from. Protected by cgroup_lock()
151 struct mem_cgroup *last_scanned_child;
153 * Should the accounting and control be hierarchical, per subtree?
156 unsigned long last_oom_jiffies;
160 * statistics. This must be placed at the end of memcg.
162 struct mem_cgroup_stat stat;
166 MEM_CGROUP_CHARGE_TYPE_CACHE = 0,
167 MEM_CGROUP_CHARGE_TYPE_MAPPED,
168 MEM_CGROUP_CHARGE_TYPE_SHMEM, /* used by page migration of shmem */
169 MEM_CGROUP_CHARGE_TYPE_FORCE, /* used by force_empty */
170 MEM_CGROUP_CHARGE_TYPE_SWAPOUT, /* for accounting swapcache */
174 /* only for here (for easy reading.) */
175 #define PCGF_CACHE (1UL << PCG_CACHE)
176 #define PCGF_USED (1UL << PCG_USED)
177 #define PCGF_LOCK (1UL << PCG_LOCK)
178 static const unsigned long
179 pcg_default_flags[NR_CHARGE_TYPE] = {
180 PCGF_CACHE | PCGF_USED | PCGF_LOCK, /* File Cache */
181 PCGF_USED | PCGF_LOCK, /* Anon */
182 PCGF_CACHE | PCGF_USED | PCGF_LOCK, /* Shmem */
187 /* for encoding cft->private value on file */
190 #define MEMFILE_PRIVATE(x, val) (((x) << 16) | (val))
191 #define MEMFILE_TYPE(val) (((val) >> 16) & 0xffff)
192 #define MEMFILE_ATTR(val) ((val) & 0xffff)
194 static void mem_cgroup_get(struct mem_cgroup *mem);
195 static void mem_cgroup_put(struct mem_cgroup *mem);
197 static void mem_cgroup_charge_statistics(struct mem_cgroup *mem,
198 struct page_cgroup *pc,
201 int val = (charge)? 1 : -1;
202 struct mem_cgroup_stat *stat = &mem->stat;
203 struct mem_cgroup_stat_cpu *cpustat;
206 cpustat = &stat->cpustat[cpu];
207 if (PageCgroupCache(pc))
208 __mem_cgroup_stat_add_safe(cpustat, MEM_CGROUP_STAT_CACHE, val);
210 __mem_cgroup_stat_add_safe(cpustat, MEM_CGROUP_STAT_RSS, val);
213 __mem_cgroup_stat_add_safe(cpustat,
214 MEM_CGROUP_STAT_PGPGIN_COUNT, 1);
216 __mem_cgroup_stat_add_safe(cpustat,
217 MEM_CGROUP_STAT_PGPGOUT_COUNT, 1);
221 static struct mem_cgroup_per_zone *
222 mem_cgroup_zoneinfo(struct mem_cgroup *mem, int nid, int zid)
224 return &mem->info.nodeinfo[nid]->zoneinfo[zid];
227 static struct mem_cgroup_per_zone *
228 page_cgroup_zoneinfo(struct page_cgroup *pc)
230 struct mem_cgroup *mem = pc->mem_cgroup;
231 int nid = page_cgroup_nid(pc);
232 int zid = page_cgroup_zid(pc);
234 return mem_cgroup_zoneinfo(mem, nid, zid);
237 static unsigned long mem_cgroup_get_all_zonestat(struct mem_cgroup *mem,
241 struct mem_cgroup_per_zone *mz;
244 for_each_online_node(nid)
245 for (zid = 0; zid < MAX_NR_ZONES; zid++) {
246 mz = mem_cgroup_zoneinfo(mem, nid, zid);
247 total += MEM_CGROUP_ZSTAT(mz, idx);
252 static struct mem_cgroup *mem_cgroup_from_cont(struct cgroup *cont)
254 return container_of(cgroup_subsys_state(cont,
255 mem_cgroup_subsys_id), struct mem_cgroup,
259 struct mem_cgroup *mem_cgroup_from_task(struct task_struct *p)
262 * mm_update_next_owner() may clear mm->owner to NULL
263 * if it races with swapoff, page migration, etc.
264 * So this can be called with p == NULL.
269 return container_of(task_subsys_state(p, mem_cgroup_subsys_id),
270 struct mem_cgroup, css);
274 * Following LRU functions are allowed to be used without PCG_LOCK.
275 * Operations are called by routine of global LRU independently from memcg.
276 * What we have to take care of here is validness of pc->mem_cgroup.
278 * Changes to pc->mem_cgroup happens when
281 * In typical case, "charge" is done before add-to-lru. Exception is SwapCache.
282 * It is added to LRU before charge.
283 * If PCG_USED bit is not set, page_cgroup is not added to this private LRU.
284 * When moving account, the page is not on LRU. It's isolated.
287 void mem_cgroup_del_lru_list(struct page *page, enum lru_list lru)
289 struct page_cgroup *pc;
290 struct mem_cgroup *mem;
291 struct mem_cgroup_per_zone *mz;
293 if (mem_cgroup_disabled())
295 pc = lookup_page_cgroup(page);
296 /* can happen while we handle swapcache. */
297 if (list_empty(&pc->lru))
299 mz = page_cgroup_zoneinfo(pc);
300 mem = pc->mem_cgroup;
301 MEM_CGROUP_ZSTAT(mz, lru) -= 1;
302 list_del_init(&pc->lru);
306 void mem_cgroup_del_lru(struct page *page)
308 mem_cgroup_del_lru_list(page, page_lru(page));
311 void mem_cgroup_rotate_lru_list(struct page *page, enum lru_list lru)
313 struct mem_cgroup_per_zone *mz;
314 struct page_cgroup *pc;
316 if (mem_cgroup_disabled())
319 pc = lookup_page_cgroup(page);
321 /* unused page is not rotated. */
322 if (!PageCgroupUsed(pc))
324 mz = page_cgroup_zoneinfo(pc);
325 list_move(&pc->lru, &mz->lists[lru]);
328 void mem_cgroup_add_lru_list(struct page *page, enum lru_list lru)
330 struct page_cgroup *pc;
331 struct mem_cgroup_per_zone *mz;
333 if (mem_cgroup_disabled())
335 pc = lookup_page_cgroup(page);
336 /* barrier to sync with "charge" */
338 if (!PageCgroupUsed(pc))
341 mz = page_cgroup_zoneinfo(pc);
342 MEM_CGROUP_ZSTAT(mz, lru) += 1;
343 list_add(&pc->lru, &mz->lists[lru]);
346 * To add swapcache into LRU. Be careful to all this function.
347 * zone->lru_lock shouldn't be held and irq must not be disabled.
349 static void mem_cgroup_lru_fixup(struct page *page)
351 if (!isolate_lru_page(page))
352 putback_lru_page(page);
355 void mem_cgroup_move_lists(struct page *page,
356 enum lru_list from, enum lru_list to)
358 if (mem_cgroup_disabled())
360 mem_cgroup_del_lru_list(page, from);
361 mem_cgroup_add_lru_list(page, to);
364 int task_in_mem_cgroup(struct task_struct *task, const struct mem_cgroup *mem)
369 ret = task->mm && mm_match_cgroup(task->mm, mem);
375 * Calculate mapped_ratio under memory controller. This will be used in
376 * vmscan.c for deteremining we have to reclaim mapped pages.
378 int mem_cgroup_calc_mapped_ratio(struct mem_cgroup *mem)
383 * usage is recorded in bytes. But, here, we assume the number of
384 * physical pages can be represented by "long" on any arch.
386 total = (long) (mem->res.usage >> PAGE_SHIFT) + 1L;
387 rss = (long)mem_cgroup_read_stat(&mem->stat, MEM_CGROUP_STAT_RSS);
388 return (int)((rss * 100L) / total);
392 * prev_priority control...this will be used in memory reclaim path.
394 int mem_cgroup_get_reclaim_priority(struct mem_cgroup *mem)
396 return mem->prev_priority;
399 void mem_cgroup_note_reclaim_priority(struct mem_cgroup *mem, int priority)
401 if (priority < mem->prev_priority)
402 mem->prev_priority = priority;
405 void mem_cgroup_record_reclaim_priority(struct mem_cgroup *mem, int priority)
407 mem->prev_priority = priority;
411 * Calculate # of pages to be scanned in this priority/zone.
414 * priority starts from "DEF_PRIORITY" and decremented in each loop.
415 * (see include/linux/mmzone.h)
418 long mem_cgroup_calc_reclaim(struct mem_cgroup *mem, struct zone *zone,
419 int priority, enum lru_list lru)
422 int nid = zone->zone_pgdat->node_id;
423 int zid = zone_idx(zone);
424 struct mem_cgroup_per_zone *mz = mem_cgroup_zoneinfo(mem, nid, zid);
426 nr_pages = MEM_CGROUP_ZSTAT(mz, lru);
428 return (nr_pages >> priority);
431 unsigned long mem_cgroup_isolate_pages(unsigned long nr_to_scan,
432 struct list_head *dst,
433 unsigned long *scanned, int order,
434 int mode, struct zone *z,
435 struct mem_cgroup *mem_cont,
436 int active, int file)
438 unsigned long nr_taken = 0;
442 struct list_head *src;
443 struct page_cgroup *pc, *tmp;
444 int nid = z->zone_pgdat->node_id;
445 int zid = zone_idx(z);
446 struct mem_cgroup_per_zone *mz;
447 int lru = LRU_FILE * !!file + !!active;
450 mz = mem_cgroup_zoneinfo(mem_cont, nid, zid);
451 src = &mz->lists[lru];
454 list_for_each_entry_safe_reverse(pc, tmp, src, lru) {
455 if (scan >= nr_to_scan)
459 if (unlikely(!PageCgroupUsed(pc)))
461 if (unlikely(!PageLRU(page)))
465 if (__isolate_lru_page(page, mode, file) == 0) {
466 list_move(&page->lru, dst);
475 #define mem_cgroup_from_res_counter(counter, member) \
476 container_of(counter, struct mem_cgroup, member)
479 * This routine finds the DFS walk successor. This routine should be
480 * called with cgroup_mutex held
482 static struct mem_cgroup *
483 mem_cgroup_get_next_node(struct mem_cgroup *curr, struct mem_cgroup *root_mem)
485 struct cgroup *cgroup, *curr_cgroup, *root_cgroup;
487 curr_cgroup = curr->css.cgroup;
488 root_cgroup = root_mem->css.cgroup;
490 if (!list_empty(&curr_cgroup->children)) {
492 * Walk down to children
494 mem_cgroup_put(curr);
495 cgroup = list_entry(curr_cgroup->children.next,
496 struct cgroup, sibling);
497 curr = mem_cgroup_from_cont(cgroup);
498 mem_cgroup_get(curr);
503 if (curr_cgroup == root_cgroup) {
504 mem_cgroup_put(curr);
506 mem_cgroup_get(curr);
513 if (curr_cgroup->sibling.next != &curr_cgroup->parent->children) {
514 mem_cgroup_put(curr);
515 cgroup = list_entry(curr_cgroup->sibling.next, struct cgroup,
517 curr = mem_cgroup_from_cont(cgroup);
518 mem_cgroup_get(curr);
523 * Go up to next parent and next parent's sibling if need be
525 curr_cgroup = curr_cgroup->parent;
529 root_mem->last_scanned_child = curr;
534 * Visit the first child (need not be the first child as per the ordering
535 * of the cgroup list, since we track last_scanned_child) of @mem and use
536 * that to reclaim free pages from.
538 static struct mem_cgroup *
539 mem_cgroup_get_first_node(struct mem_cgroup *root_mem)
541 struct cgroup *cgroup;
542 struct mem_cgroup *ret;
543 bool obsolete = (root_mem->last_scanned_child &&
544 root_mem->last_scanned_child->obsolete);
547 * Scan all children under the mem_cgroup mem
550 if (list_empty(&root_mem->css.cgroup->children)) {
555 if (!root_mem->last_scanned_child || obsolete) {
558 mem_cgroup_put(root_mem->last_scanned_child);
560 cgroup = list_first_entry(&root_mem->css.cgroup->children,
561 struct cgroup, sibling);
562 ret = mem_cgroup_from_cont(cgroup);
565 ret = mem_cgroup_get_next_node(root_mem->last_scanned_child,
569 root_mem->last_scanned_child = ret;
574 static bool mem_cgroup_check_under_limit(struct mem_cgroup *mem)
576 if (do_swap_account) {
577 if (res_counter_check_under_limit(&mem->res) &&
578 res_counter_check_under_limit(&mem->memsw))
581 if (res_counter_check_under_limit(&mem->res))
587 * Dance down the hierarchy if needed to reclaim memory. We remember the
588 * last child we reclaimed from, so that we don't end up penalizing
589 * one child extensively based on its position in the children list.
591 * root_mem is the original ancestor that we've been reclaim from.
593 static int mem_cgroup_hierarchical_reclaim(struct mem_cgroup *root_mem,
594 gfp_t gfp_mask, bool noswap)
596 struct mem_cgroup *next_mem;
600 * Reclaim unconditionally and don't check for return value.
601 * We need to reclaim in the current group and down the tree.
602 * One might think about checking for children before reclaiming,
603 * but there might be left over accounting, even after children
606 ret = try_to_free_mem_cgroup_pages(root_mem, gfp_mask, noswap);
607 if (mem_cgroup_check_under_limit(root_mem))
610 next_mem = mem_cgroup_get_first_node(root_mem);
612 while (next_mem != root_mem) {
613 if (next_mem->obsolete) {
614 mem_cgroup_put(next_mem);
616 next_mem = mem_cgroup_get_first_node(root_mem);
620 ret = try_to_free_mem_cgroup_pages(next_mem, gfp_mask, noswap);
621 if (mem_cgroup_check_under_limit(root_mem))
624 next_mem = mem_cgroup_get_next_node(next_mem, root_mem);
630 bool mem_cgroup_oom_called(struct task_struct *task)
633 struct mem_cgroup *mem;
634 struct mm_struct *mm;
640 mem = mem_cgroup_from_task(rcu_dereference(mm->owner));
641 if (mem && time_before(jiffies, mem->last_oom_jiffies + HZ/10))
647 * Unlike exported interface, "oom" parameter is added. if oom==true,
648 * oom-killer can be invoked.
650 static int __mem_cgroup_try_charge(struct mm_struct *mm,
651 gfp_t gfp_mask, struct mem_cgroup **memcg,
654 struct mem_cgroup *mem, *mem_over_limit;
655 int nr_retries = MEM_CGROUP_RECLAIM_RETRIES;
656 struct res_counter *fail_res;
658 if (unlikely(test_thread_flag(TIF_MEMDIE))) {
659 /* Don't account this! */
665 * We always charge the cgroup the mm_struct belongs to.
666 * The mm_struct's mem_cgroup changes on task migration if the
667 * thread group leader migrates. It's possible that mm is not
668 * set, if so charge the init_mm (happens for pagecache usage).
670 if (likely(!*memcg)) {
672 mem = mem_cgroup_from_task(rcu_dereference(mm->owner));
673 if (unlikely(!mem)) {
678 * For every charge from the cgroup, increment reference count
692 ret = res_counter_charge(&mem->res, PAGE_SIZE, &fail_res);
694 if (!do_swap_account)
696 ret = res_counter_charge(&mem->memsw, PAGE_SIZE,
700 /* mem+swap counter fails */
701 res_counter_uncharge(&mem->res, PAGE_SIZE);
703 mem_over_limit = mem_cgroup_from_res_counter(fail_res,
706 /* mem counter fails */
707 mem_over_limit = mem_cgroup_from_res_counter(fail_res,
710 if (!(gfp_mask & __GFP_WAIT))
713 ret = mem_cgroup_hierarchical_reclaim(mem_over_limit, gfp_mask,
717 * try_to_free_mem_cgroup_pages() might not give us a full
718 * picture of reclaim. Some pages are reclaimed and might be
719 * moved to swap cache or just unmapped from the cgroup.
720 * Check the limit again to see if the reclaim reduced the
721 * current usage of the cgroup before giving up
724 if (mem_cgroup_check_under_limit(mem_over_limit))
729 mem_cgroup_out_of_memory(mem_over_limit, gfp_mask);
730 mem_over_limit->last_oom_jiffies = jiffies;
742 * mem_cgroup_try_charge - get charge of PAGE_SIZE.
743 * @mm: an mm_struct which is charged against. (when *memcg is NULL)
744 * @gfp_mask: gfp_mask for reclaim.
745 * @memcg: a pointer to memory cgroup which is charged against.
747 * charge against memory cgroup pointed by *memcg. if *memcg == NULL, estimated
748 * memory cgroup from @mm is got and stored in *memcg.
750 * Returns 0 if success. -ENOMEM at failure.
751 * This call can invoke OOM-Killer.
754 int mem_cgroup_try_charge(struct mm_struct *mm,
755 gfp_t mask, struct mem_cgroup **memcg)
757 return __mem_cgroup_try_charge(mm, mask, memcg, true);
761 * commit a charge got by mem_cgroup_try_charge() and makes page_cgroup to be
762 * USED state. If already USED, uncharge and return.
765 static void __mem_cgroup_commit_charge(struct mem_cgroup *mem,
766 struct page_cgroup *pc,
767 enum charge_type ctype)
769 /* try_charge() can return NULL to *memcg, taking care of it. */
773 lock_page_cgroup(pc);
774 if (unlikely(PageCgroupUsed(pc))) {
775 unlock_page_cgroup(pc);
776 res_counter_uncharge(&mem->res, PAGE_SIZE);
778 res_counter_uncharge(&mem->memsw, PAGE_SIZE);
782 pc->mem_cgroup = mem;
784 pc->flags = pcg_default_flags[ctype];
786 mem_cgroup_charge_statistics(mem, pc, true);
788 unlock_page_cgroup(pc);
792 * mem_cgroup_move_account - move account of the page
793 * @pc: page_cgroup of the page.
794 * @from: mem_cgroup which the page is moved from.
795 * @to: mem_cgroup which the page is moved to. @from != @to.
797 * The caller must confirm following.
798 * - page is not on LRU (isolate_page() is useful.)
800 * returns 0 at success,
801 * returns -EBUSY when lock is busy or "pc" is unstable.
803 * This function does "uncharge" from old cgroup but doesn't do "charge" to
804 * new cgroup. It should be done by a caller.
807 static int mem_cgroup_move_account(struct page_cgroup *pc,
808 struct mem_cgroup *from, struct mem_cgroup *to)
810 struct mem_cgroup_per_zone *from_mz, *to_mz;
814 VM_BUG_ON(from == to);
815 VM_BUG_ON(PageLRU(pc->page));
817 nid = page_cgroup_nid(pc);
818 zid = page_cgroup_zid(pc);
819 from_mz = mem_cgroup_zoneinfo(from, nid, zid);
820 to_mz = mem_cgroup_zoneinfo(to, nid, zid);
822 if (!trylock_page_cgroup(pc))
825 if (!PageCgroupUsed(pc))
828 if (pc->mem_cgroup != from)
832 res_counter_uncharge(&from->res, PAGE_SIZE);
833 mem_cgroup_charge_statistics(from, pc, false);
835 res_counter_uncharge(&from->memsw, PAGE_SIZE);
837 mem_cgroup_charge_statistics(to, pc, true);
841 unlock_page_cgroup(pc);
846 * move charges to its parent.
849 static int mem_cgroup_move_parent(struct page_cgroup *pc,
850 struct mem_cgroup *child,
853 struct page *page = pc->page;
854 struct cgroup *cg = child->css.cgroup;
855 struct cgroup *pcg = cg->parent;
856 struct mem_cgroup *parent;
864 parent = mem_cgroup_from_cont(pcg);
867 ret = __mem_cgroup_try_charge(NULL, gfp_mask, &parent, false);
871 if (!get_page_unless_zero(page))
874 ret = isolate_lru_page(page);
879 ret = mem_cgroup_move_account(pc, child, parent);
881 /* drop extra refcnt by try_charge() (move_account increment one) */
882 css_put(&parent->css);
883 putback_lru_page(page);
888 /* uncharge if move fails */
890 res_counter_uncharge(&parent->res, PAGE_SIZE);
892 res_counter_uncharge(&parent->memsw, PAGE_SIZE);
898 * Charge the memory controller for page usage.
900 * 0 if the charge was successful
901 * < 0 if the cgroup is over its limit
903 static int mem_cgroup_charge_common(struct page *page, struct mm_struct *mm,
904 gfp_t gfp_mask, enum charge_type ctype,
905 struct mem_cgroup *memcg)
907 struct mem_cgroup *mem;
908 struct page_cgroup *pc;
911 pc = lookup_page_cgroup(page);
912 /* can happen at boot */
918 ret = __mem_cgroup_try_charge(mm, gfp_mask, &mem, true);
922 __mem_cgroup_commit_charge(mem, pc, ctype);
926 int mem_cgroup_newpage_charge(struct page *page,
927 struct mm_struct *mm, gfp_t gfp_mask)
929 if (mem_cgroup_disabled())
931 if (PageCompound(page))
934 * If already mapped, we don't have to account.
935 * If page cache, page->mapping has address_space.
936 * But page->mapping may have out-of-use anon_vma pointer,
937 * detecit it by PageAnon() check. newly-mapped-anon's page->mapping
940 if (page_mapped(page) || (page->mapping && !PageAnon(page)))
944 return mem_cgroup_charge_common(page, mm, gfp_mask,
945 MEM_CGROUP_CHARGE_TYPE_MAPPED, NULL);
948 int mem_cgroup_cache_charge(struct page *page, struct mm_struct *mm,
951 if (mem_cgroup_disabled())
953 if (PageCompound(page))
956 * Corner case handling. This is called from add_to_page_cache()
957 * in usual. But some FS (shmem) precharges this page before calling it
958 * and call add_to_page_cache() with GFP_NOWAIT.
960 * For GFP_NOWAIT case, the page may be pre-charged before calling
961 * add_to_page_cache(). (See shmem.c) check it here and avoid to call
962 * charge twice. (It works but has to pay a bit larger cost.)
964 if (!(gfp_mask & __GFP_WAIT)) {
965 struct page_cgroup *pc;
968 pc = lookup_page_cgroup(page);
971 lock_page_cgroup(pc);
972 if (PageCgroupUsed(pc)) {
973 unlock_page_cgroup(pc);
976 unlock_page_cgroup(pc);
982 if (page_is_file_cache(page))
983 return mem_cgroup_charge_common(page, mm, gfp_mask,
984 MEM_CGROUP_CHARGE_TYPE_CACHE, NULL);
986 return mem_cgroup_charge_common(page, mm, gfp_mask,
987 MEM_CGROUP_CHARGE_TYPE_SHMEM, NULL);
990 int mem_cgroup_try_charge_swapin(struct mm_struct *mm,
992 gfp_t mask, struct mem_cgroup **ptr)
994 struct mem_cgroup *mem;
997 if (mem_cgroup_disabled())
1000 if (!do_swap_account)
1004 * A racing thread's fault, or swapoff, may have already updated
1005 * the pte, and even removed page from swap cache: return success
1006 * to go on to do_swap_page()'s pte_same() test, which should fail.
1008 if (!PageSwapCache(page))
1011 ent.val = page_private(page);
1013 mem = lookup_swap_cgroup(ent);
1014 if (!mem || mem->obsolete)
1017 return __mem_cgroup_try_charge(NULL, mask, ptr, true);
1021 return __mem_cgroup_try_charge(mm, mask, ptr, true);
1026 int mem_cgroup_cache_charge_swapin(struct page *page,
1027 struct mm_struct *mm, gfp_t mask, bool locked)
1031 if (mem_cgroup_disabled())
1038 * If not locked, the page can be dropped from SwapCache until
1041 if (PageSwapCache(page)) {
1042 struct mem_cgroup *mem = NULL;
1045 ent.val = page_private(page);
1046 if (do_swap_account) {
1047 mem = lookup_swap_cgroup(ent);
1048 if (mem && mem->obsolete)
1053 ret = mem_cgroup_charge_common(page, mm, mask,
1054 MEM_CGROUP_CHARGE_TYPE_SHMEM, mem);
1056 if (!ret && do_swap_account) {
1057 /* avoid double counting */
1058 mem = swap_cgroup_record(ent, NULL);
1060 res_counter_uncharge(&mem->memsw, PAGE_SIZE);
1061 mem_cgroup_put(mem);
1067 /* add this page(page_cgroup) to the LRU we want. */
1068 mem_cgroup_lru_fixup(page);
1074 void mem_cgroup_commit_charge_swapin(struct page *page, struct mem_cgroup *ptr)
1076 struct page_cgroup *pc;
1078 if (mem_cgroup_disabled())
1082 pc = lookup_page_cgroup(page);
1083 __mem_cgroup_commit_charge(ptr, pc, MEM_CGROUP_CHARGE_TYPE_MAPPED);
1085 * Now swap is on-memory. This means this page may be
1086 * counted both as mem and swap....double count.
1087 * Fix it by uncharging from memsw. This SwapCache is stable
1088 * because we're still under lock_page().
1090 if (do_swap_account) {
1091 swp_entry_t ent = {.val = page_private(page)};
1092 struct mem_cgroup *memcg;
1093 memcg = swap_cgroup_record(ent, NULL);
1095 /* If memcg is obsolete, memcg can be != ptr */
1096 res_counter_uncharge(&memcg->memsw, PAGE_SIZE);
1097 mem_cgroup_put(memcg);
1101 /* add this page(page_cgroup) to the LRU we want. */
1102 mem_cgroup_lru_fixup(page);
1105 void mem_cgroup_cancel_charge_swapin(struct mem_cgroup *mem)
1107 if (mem_cgroup_disabled())
1111 res_counter_uncharge(&mem->res, PAGE_SIZE);
1112 if (do_swap_account)
1113 res_counter_uncharge(&mem->memsw, PAGE_SIZE);
1119 * uncharge if !page_mapped(page)
1121 static struct mem_cgroup *
1122 __mem_cgroup_uncharge_common(struct page *page, enum charge_type ctype)
1124 struct page_cgroup *pc;
1125 struct mem_cgroup *mem = NULL;
1126 struct mem_cgroup_per_zone *mz;
1128 if (mem_cgroup_disabled())
1131 if (PageSwapCache(page))
1135 * Check if our page_cgroup is valid
1137 pc = lookup_page_cgroup(page);
1138 if (unlikely(!pc || !PageCgroupUsed(pc)))
1141 lock_page_cgroup(pc);
1143 mem = pc->mem_cgroup;
1145 if (!PageCgroupUsed(pc))
1149 case MEM_CGROUP_CHARGE_TYPE_MAPPED:
1150 if (page_mapped(page))
1153 case MEM_CGROUP_CHARGE_TYPE_SWAPOUT:
1154 if (!PageAnon(page)) { /* Shared memory */
1155 if (page->mapping && !page_is_file_cache(page))
1157 } else if (page_mapped(page)) /* Anon */
1164 res_counter_uncharge(&mem->res, PAGE_SIZE);
1165 if (do_swap_account && (ctype != MEM_CGROUP_CHARGE_TYPE_SWAPOUT))
1166 res_counter_uncharge(&mem->memsw, PAGE_SIZE);
1168 mem_cgroup_charge_statistics(mem, pc, false);
1169 ClearPageCgroupUsed(pc);
1171 mz = page_cgroup_zoneinfo(pc);
1172 unlock_page_cgroup(pc);
1179 unlock_page_cgroup(pc);
1183 void mem_cgroup_uncharge_page(struct page *page)
1186 if (page_mapped(page))
1188 if (page->mapping && !PageAnon(page))
1190 __mem_cgroup_uncharge_common(page, MEM_CGROUP_CHARGE_TYPE_MAPPED);
1193 void mem_cgroup_uncharge_cache_page(struct page *page)
1195 VM_BUG_ON(page_mapped(page));
1196 VM_BUG_ON(page->mapping);
1197 __mem_cgroup_uncharge_common(page, MEM_CGROUP_CHARGE_TYPE_CACHE);
1201 * called from __delete_from_swap_cache() and drop "page" account.
1202 * memcg information is recorded to swap_cgroup of "ent"
1204 void mem_cgroup_uncharge_swapcache(struct page *page, swp_entry_t ent)
1206 struct mem_cgroup *memcg;
1208 memcg = __mem_cgroup_uncharge_common(page,
1209 MEM_CGROUP_CHARGE_TYPE_SWAPOUT);
1210 /* record memcg information */
1211 if (do_swap_account && memcg) {
1212 swap_cgroup_record(ent, memcg);
1213 mem_cgroup_get(memcg);
1217 #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP
1219 * called from swap_entry_free(). remove record in swap_cgroup and
1220 * uncharge "memsw" account.
1222 void mem_cgroup_uncharge_swap(swp_entry_t ent)
1224 struct mem_cgroup *memcg;
1226 if (!do_swap_account)
1229 memcg = swap_cgroup_record(ent, NULL);
1231 res_counter_uncharge(&memcg->memsw, PAGE_SIZE);
1232 mem_cgroup_put(memcg);
1238 * Before starting migration, account PAGE_SIZE to mem_cgroup that the old
1241 int mem_cgroup_prepare_migration(struct page *page, struct mem_cgroup **ptr)
1243 struct page_cgroup *pc;
1244 struct mem_cgroup *mem = NULL;
1247 if (mem_cgroup_disabled())
1250 pc = lookup_page_cgroup(page);
1251 lock_page_cgroup(pc);
1252 if (PageCgroupUsed(pc)) {
1253 mem = pc->mem_cgroup;
1256 unlock_page_cgroup(pc);
1259 ret = mem_cgroup_try_charge(NULL, GFP_KERNEL, &mem);
1266 /* remove redundant charge if migration failed*/
1267 void mem_cgroup_end_migration(struct mem_cgroup *mem,
1268 struct page *oldpage, struct page *newpage)
1270 struct page *target, *unused;
1271 struct page_cgroup *pc;
1272 enum charge_type ctype;
1277 /* at migration success, oldpage->mapping is NULL. */
1278 if (oldpage->mapping) {
1286 if (PageAnon(target))
1287 ctype = MEM_CGROUP_CHARGE_TYPE_MAPPED;
1288 else if (page_is_file_cache(target))
1289 ctype = MEM_CGROUP_CHARGE_TYPE_CACHE;
1291 ctype = MEM_CGROUP_CHARGE_TYPE_SHMEM;
1293 /* unused page is not on radix-tree now. */
1295 __mem_cgroup_uncharge_common(unused, ctype);
1297 pc = lookup_page_cgroup(target);
1299 * __mem_cgroup_commit_charge() check PCG_USED bit of page_cgroup.
1300 * So, double-counting is effectively avoided.
1302 __mem_cgroup_commit_charge(mem, pc, ctype);
1305 * Both of oldpage and newpage are still under lock_page().
1306 * Then, we don't have to care about race in radix-tree.
1307 * But we have to be careful that this page is unmapped or not.
1309 * There is a case for !page_mapped(). At the start of
1310 * migration, oldpage was mapped. But now, it's zapped.
1311 * But we know *target* page is not freed/reused under us.
1312 * mem_cgroup_uncharge_page() does all necessary checks.
1314 if (ctype == MEM_CGROUP_CHARGE_TYPE_MAPPED)
1315 mem_cgroup_uncharge_page(target);
1319 * A call to try to shrink memory usage under specified resource controller.
1320 * This is typically used for page reclaiming for shmem for reducing side
1321 * effect of page allocation from shmem, which is used by some mem_cgroup.
1323 int mem_cgroup_shrink_usage(struct mm_struct *mm, gfp_t gfp_mask)
1325 struct mem_cgroup *mem;
1327 int retry = MEM_CGROUP_RECLAIM_RETRIES;
1329 if (mem_cgroup_disabled())
1335 mem = mem_cgroup_from_task(rcu_dereference(mm->owner));
1336 if (unlikely(!mem)) {
1344 progress = try_to_free_mem_cgroup_pages(mem, gfp_mask, true);
1345 progress += mem_cgroup_check_under_limit(mem);
1346 } while (!progress && --retry);
1354 static DEFINE_MUTEX(set_limit_mutex);
1356 static int mem_cgroup_resize_limit(struct mem_cgroup *memcg,
1357 unsigned long long val)
1360 int retry_count = MEM_CGROUP_RECLAIM_RETRIES;
1365 while (retry_count) {
1366 if (signal_pending(current)) {
1371 * Rather than hide all in some function, I do this in
1372 * open coded manner. You see what this really does.
1373 * We have to guarantee mem->res.limit < mem->memsw.limit.
1375 mutex_lock(&set_limit_mutex);
1376 memswlimit = res_counter_read_u64(&memcg->memsw, RES_LIMIT);
1377 if (memswlimit < val) {
1379 mutex_unlock(&set_limit_mutex);
1382 ret = res_counter_set_limit(&memcg->res, val);
1383 mutex_unlock(&set_limit_mutex);
1388 progress = try_to_free_mem_cgroup_pages(memcg,
1390 if (!progress) retry_count--;
1395 int mem_cgroup_resize_memsw_limit(struct mem_cgroup *memcg,
1396 unsigned long long val)
1398 int retry_count = MEM_CGROUP_RECLAIM_RETRIES;
1399 u64 memlimit, oldusage, curusage;
1402 if (!do_swap_account)
1405 while (retry_count) {
1406 if (signal_pending(current)) {
1411 * Rather than hide all in some function, I do this in
1412 * open coded manner. You see what this really does.
1413 * We have to guarantee mem->res.limit < mem->memsw.limit.
1415 mutex_lock(&set_limit_mutex);
1416 memlimit = res_counter_read_u64(&memcg->res, RES_LIMIT);
1417 if (memlimit > val) {
1419 mutex_unlock(&set_limit_mutex);
1422 ret = res_counter_set_limit(&memcg->memsw, val);
1423 mutex_unlock(&set_limit_mutex);
1428 oldusage = res_counter_read_u64(&memcg->memsw, RES_USAGE);
1429 try_to_free_mem_cgroup_pages(memcg, GFP_KERNEL, true);
1430 curusage = res_counter_read_u64(&memcg->memsw, RES_USAGE);
1431 if (curusage >= oldusage)
1438 * This routine traverse page_cgroup in given list and drop them all.
1439 * *And* this routine doesn't reclaim page itself, just removes page_cgroup.
1441 static int mem_cgroup_force_empty_list(struct mem_cgroup *mem,
1442 int node, int zid, enum lru_list lru)
1445 struct mem_cgroup_per_zone *mz;
1446 struct page_cgroup *pc, *busy;
1447 unsigned long flags, loop;
1448 struct list_head *list;
1451 zone = &NODE_DATA(node)->node_zones[zid];
1452 mz = mem_cgroup_zoneinfo(mem, node, zid);
1453 list = &mz->lists[lru];
1455 loop = MEM_CGROUP_ZSTAT(mz, lru);
1456 /* give some margin against EBUSY etc...*/
1461 spin_lock_irqsave(&zone->lru_lock, flags);
1462 if (list_empty(list)) {
1463 spin_unlock_irqrestore(&zone->lru_lock, flags);
1466 pc = list_entry(list->prev, struct page_cgroup, lru);
1468 list_move(&pc->lru, list);
1470 spin_unlock_irqrestore(&zone->lru_lock, flags);
1473 spin_unlock_irqrestore(&zone->lru_lock, flags);
1475 ret = mem_cgroup_move_parent(pc, mem, GFP_KERNEL);
1479 if (ret == -EBUSY || ret == -EINVAL) {
1480 /* found lock contention or "pc" is obsolete. */
1487 if (!ret && !list_empty(list))
1493 * make mem_cgroup's charge to be 0 if there is no task.
1494 * This enables deleting this mem_cgroup.
1496 static int mem_cgroup_force_empty(struct mem_cgroup *mem, bool free_all)
1499 int node, zid, shrink;
1500 int nr_retries = MEM_CGROUP_RECLAIM_RETRIES;
1501 struct cgroup *cgrp = mem->css.cgroup;
1506 /* should free all ? */
1510 while (mem->res.usage > 0) {
1512 if (cgroup_task_count(cgrp) || !list_empty(&cgrp->children))
1515 if (signal_pending(current))
1517 /* This is for making all *used* pages to be on LRU. */
1518 lru_add_drain_all();
1520 for_each_node_state(node, N_POSSIBLE) {
1521 for (zid = 0; !ret && zid < MAX_NR_ZONES; zid++) {
1524 ret = mem_cgroup_force_empty_list(mem,
1533 /* it seems parent cgroup doesn't have enough mem */
1544 /* returns EBUSY if there is a task or if we come here twice. */
1545 if (cgroup_task_count(cgrp) || !list_empty(&cgrp->children) || shrink) {
1549 /* we call try-to-free pages for make this cgroup empty */
1550 lru_add_drain_all();
1551 /* try to free all pages in this cgroup */
1553 while (nr_retries && mem->res.usage > 0) {
1556 if (signal_pending(current)) {
1560 progress = try_to_free_mem_cgroup_pages(mem,
1564 /* maybe some writeback is necessary */
1565 congestion_wait(WRITE, HZ/10);
1570 /* try move_account...there may be some *locked* pages. */
1577 int mem_cgroup_force_empty_write(struct cgroup *cont, unsigned int event)
1579 return mem_cgroup_force_empty(mem_cgroup_from_cont(cont), true);
1583 static u64 mem_cgroup_hierarchy_read(struct cgroup *cont, struct cftype *cft)
1585 return mem_cgroup_from_cont(cont)->use_hierarchy;
1588 static int mem_cgroup_hierarchy_write(struct cgroup *cont, struct cftype *cft,
1592 struct mem_cgroup *mem = mem_cgroup_from_cont(cont);
1593 struct cgroup *parent = cont->parent;
1594 struct mem_cgroup *parent_mem = NULL;
1597 parent_mem = mem_cgroup_from_cont(parent);
1601 * If parent's use_hiearchy is set, we can't make any modifications
1602 * in the child subtrees. If it is unset, then the change can
1603 * occur, provided the current cgroup has no children.
1605 * For the root cgroup, parent_mem is NULL, we allow value to be
1606 * set if there are no children.
1608 if ((!parent_mem || !parent_mem->use_hierarchy) &&
1609 (val == 1 || val == 0)) {
1610 if (list_empty(&cont->children))
1611 mem->use_hierarchy = val;
1621 static u64 mem_cgroup_read(struct cgroup *cont, struct cftype *cft)
1623 struct mem_cgroup *mem = mem_cgroup_from_cont(cont);
1627 type = MEMFILE_TYPE(cft->private);
1628 name = MEMFILE_ATTR(cft->private);
1631 val = res_counter_read_u64(&mem->res, name);
1634 if (do_swap_account)
1635 val = res_counter_read_u64(&mem->memsw, name);
1644 * The user of this function is...
1647 static int mem_cgroup_write(struct cgroup *cont, struct cftype *cft,
1650 struct mem_cgroup *memcg = mem_cgroup_from_cont(cont);
1652 unsigned long long val;
1655 type = MEMFILE_TYPE(cft->private);
1656 name = MEMFILE_ATTR(cft->private);
1659 /* This function does all necessary parse...reuse it */
1660 ret = res_counter_memparse_write_strategy(buffer, &val);
1664 ret = mem_cgroup_resize_limit(memcg, val);
1666 ret = mem_cgroup_resize_memsw_limit(memcg, val);
1669 ret = -EINVAL; /* should be BUG() ? */
1675 static int mem_cgroup_reset(struct cgroup *cont, unsigned int event)
1677 struct mem_cgroup *mem;
1680 mem = mem_cgroup_from_cont(cont);
1681 type = MEMFILE_TYPE(event);
1682 name = MEMFILE_ATTR(event);
1686 res_counter_reset_max(&mem->res);
1688 res_counter_reset_max(&mem->memsw);
1692 res_counter_reset_failcnt(&mem->res);
1694 res_counter_reset_failcnt(&mem->memsw);
1700 static const struct mem_cgroup_stat_desc {
1703 } mem_cgroup_stat_desc[] = {
1704 [MEM_CGROUP_STAT_CACHE] = { "cache", PAGE_SIZE, },
1705 [MEM_CGROUP_STAT_RSS] = { "rss", PAGE_SIZE, },
1706 [MEM_CGROUP_STAT_PGPGIN_COUNT] = {"pgpgin", 1, },
1707 [MEM_CGROUP_STAT_PGPGOUT_COUNT] = {"pgpgout", 1, },
1710 static int mem_control_stat_show(struct cgroup *cont, struct cftype *cft,
1711 struct cgroup_map_cb *cb)
1713 struct mem_cgroup *mem_cont = mem_cgroup_from_cont(cont);
1714 struct mem_cgroup_stat *stat = &mem_cont->stat;
1717 for (i = 0; i < ARRAY_SIZE(stat->cpustat[0].count); i++) {
1720 val = mem_cgroup_read_stat(stat, i);
1721 val *= mem_cgroup_stat_desc[i].unit;
1722 cb->fill(cb, mem_cgroup_stat_desc[i].msg, val);
1724 /* showing # of active pages */
1726 unsigned long active_anon, inactive_anon;
1727 unsigned long active_file, inactive_file;
1728 unsigned long unevictable;
1730 inactive_anon = mem_cgroup_get_all_zonestat(mem_cont,
1732 active_anon = mem_cgroup_get_all_zonestat(mem_cont,
1734 inactive_file = mem_cgroup_get_all_zonestat(mem_cont,
1736 active_file = mem_cgroup_get_all_zonestat(mem_cont,
1738 unevictable = mem_cgroup_get_all_zonestat(mem_cont,
1741 cb->fill(cb, "active_anon", (active_anon) * PAGE_SIZE);
1742 cb->fill(cb, "inactive_anon", (inactive_anon) * PAGE_SIZE);
1743 cb->fill(cb, "active_file", (active_file) * PAGE_SIZE);
1744 cb->fill(cb, "inactive_file", (inactive_file) * PAGE_SIZE);
1745 cb->fill(cb, "unevictable", unevictable * PAGE_SIZE);
1752 static struct cftype mem_cgroup_files[] = {
1754 .name = "usage_in_bytes",
1755 .private = MEMFILE_PRIVATE(_MEM, RES_USAGE),
1756 .read_u64 = mem_cgroup_read,
1759 .name = "max_usage_in_bytes",
1760 .private = MEMFILE_PRIVATE(_MEM, RES_MAX_USAGE),
1761 .trigger = mem_cgroup_reset,
1762 .read_u64 = mem_cgroup_read,
1765 .name = "limit_in_bytes",
1766 .private = MEMFILE_PRIVATE(_MEM, RES_LIMIT),
1767 .write_string = mem_cgroup_write,
1768 .read_u64 = mem_cgroup_read,
1772 .private = MEMFILE_PRIVATE(_MEM, RES_FAILCNT),
1773 .trigger = mem_cgroup_reset,
1774 .read_u64 = mem_cgroup_read,
1778 .read_map = mem_control_stat_show,
1781 .name = "force_empty",
1782 .trigger = mem_cgroup_force_empty_write,
1785 .name = "use_hierarchy",
1786 .write_u64 = mem_cgroup_hierarchy_write,
1787 .read_u64 = mem_cgroup_hierarchy_read,
1791 #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP
1792 static struct cftype memsw_cgroup_files[] = {
1794 .name = "memsw.usage_in_bytes",
1795 .private = MEMFILE_PRIVATE(_MEMSWAP, RES_USAGE),
1796 .read_u64 = mem_cgroup_read,
1799 .name = "memsw.max_usage_in_bytes",
1800 .private = MEMFILE_PRIVATE(_MEMSWAP, RES_MAX_USAGE),
1801 .trigger = mem_cgroup_reset,
1802 .read_u64 = mem_cgroup_read,
1805 .name = "memsw.limit_in_bytes",
1806 .private = MEMFILE_PRIVATE(_MEMSWAP, RES_LIMIT),
1807 .write_string = mem_cgroup_write,
1808 .read_u64 = mem_cgroup_read,
1811 .name = "memsw.failcnt",
1812 .private = MEMFILE_PRIVATE(_MEMSWAP, RES_FAILCNT),
1813 .trigger = mem_cgroup_reset,
1814 .read_u64 = mem_cgroup_read,
1818 static int register_memsw_files(struct cgroup *cont, struct cgroup_subsys *ss)
1820 if (!do_swap_account)
1822 return cgroup_add_files(cont, ss, memsw_cgroup_files,
1823 ARRAY_SIZE(memsw_cgroup_files));
1826 static int register_memsw_files(struct cgroup *cont, struct cgroup_subsys *ss)
1832 static int alloc_mem_cgroup_per_zone_info(struct mem_cgroup *mem, int node)
1834 struct mem_cgroup_per_node *pn;
1835 struct mem_cgroup_per_zone *mz;
1837 int zone, tmp = node;
1839 * This routine is called against possible nodes.
1840 * But it's BUG to call kmalloc() against offline node.
1842 * TODO: this routine can waste much memory for nodes which will
1843 * never be onlined. It's better to use memory hotplug callback
1846 if (!node_state(node, N_NORMAL_MEMORY))
1848 pn = kmalloc_node(sizeof(*pn), GFP_KERNEL, tmp);
1852 mem->info.nodeinfo[node] = pn;
1853 memset(pn, 0, sizeof(*pn));
1855 for (zone = 0; zone < MAX_NR_ZONES; zone++) {
1856 mz = &pn->zoneinfo[zone];
1858 INIT_LIST_HEAD(&mz->lists[l]);
1863 static void free_mem_cgroup_per_zone_info(struct mem_cgroup *mem, int node)
1865 kfree(mem->info.nodeinfo[node]);
1868 static int mem_cgroup_size(void)
1870 int cpustat_size = nr_cpu_ids * sizeof(struct mem_cgroup_stat_cpu);
1871 return sizeof(struct mem_cgroup) + cpustat_size;
1874 static struct mem_cgroup *mem_cgroup_alloc(void)
1876 struct mem_cgroup *mem;
1877 int size = mem_cgroup_size();
1879 if (size < PAGE_SIZE)
1880 mem = kmalloc(size, GFP_KERNEL);
1882 mem = vmalloc(size);
1885 memset(mem, 0, size);
1890 * At destroying mem_cgroup, references from swap_cgroup can remain.
1891 * (scanning all at force_empty is too costly...)
1893 * Instead of clearing all references at force_empty, we remember
1894 * the number of reference from swap_cgroup and free mem_cgroup when
1895 * it goes down to 0.
1897 * When mem_cgroup is destroyed, mem->obsolete will be set to 0 and
1898 * entry which points to this memcg will be ignore at swapin.
1900 * Removal of cgroup itself succeeds regardless of refs from swap.
1903 static void mem_cgroup_free(struct mem_cgroup *mem)
1907 if (atomic_read(&mem->refcnt) > 0)
1911 for_each_node_state(node, N_POSSIBLE)
1912 free_mem_cgroup_per_zone_info(mem, node);
1914 if (mem_cgroup_size() < PAGE_SIZE)
1920 static void mem_cgroup_get(struct mem_cgroup *mem)
1922 atomic_inc(&mem->refcnt);
1925 static void mem_cgroup_put(struct mem_cgroup *mem)
1927 if (atomic_dec_and_test(&mem->refcnt)) {
1930 mem_cgroup_free(mem);
1935 #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP
1936 static void __init enable_swap_cgroup(void)
1938 if (!mem_cgroup_disabled() && really_do_swap_account)
1939 do_swap_account = 1;
1942 static void __init enable_swap_cgroup(void)
1947 static struct cgroup_subsys_state *
1948 mem_cgroup_create(struct cgroup_subsys *ss, struct cgroup *cont)
1950 struct mem_cgroup *mem, *parent;
1953 mem = mem_cgroup_alloc();
1955 return ERR_PTR(-ENOMEM);
1957 for_each_node_state(node, N_POSSIBLE)
1958 if (alloc_mem_cgroup_per_zone_info(mem, node))
1961 if (cont->parent == NULL) {
1962 enable_swap_cgroup();
1965 parent = mem_cgroup_from_cont(cont->parent);
1966 mem->use_hierarchy = parent->use_hierarchy;
1969 if (parent && parent->use_hierarchy) {
1970 res_counter_init(&mem->res, &parent->res);
1971 res_counter_init(&mem->memsw, &parent->memsw);
1973 res_counter_init(&mem->res, NULL);
1974 res_counter_init(&mem->memsw, NULL);
1977 mem->last_scanned_child = NULL;
1981 for_each_node_state(node, N_POSSIBLE)
1982 free_mem_cgroup_per_zone_info(mem, node);
1983 mem_cgroup_free(mem);
1984 return ERR_PTR(-ENOMEM);
1987 static void mem_cgroup_pre_destroy(struct cgroup_subsys *ss,
1988 struct cgroup *cont)
1990 struct mem_cgroup *mem = mem_cgroup_from_cont(cont);
1992 mem_cgroup_force_empty(mem, false);
1995 static void mem_cgroup_destroy(struct cgroup_subsys *ss,
1996 struct cgroup *cont)
1998 mem_cgroup_free(mem_cgroup_from_cont(cont));
2001 static int mem_cgroup_populate(struct cgroup_subsys *ss,
2002 struct cgroup *cont)
2006 ret = cgroup_add_files(cont, ss, mem_cgroup_files,
2007 ARRAY_SIZE(mem_cgroup_files));
2010 ret = register_memsw_files(cont, ss);
2014 static void mem_cgroup_move_task(struct cgroup_subsys *ss,
2015 struct cgroup *cont,
2016 struct cgroup *old_cont,
2017 struct task_struct *p)
2020 * FIXME: It's better to move charges of this process from old
2021 * memcg to new memcg. But it's just on TODO-List now.
2025 struct cgroup_subsys mem_cgroup_subsys = {
2027 .subsys_id = mem_cgroup_subsys_id,
2028 .create = mem_cgroup_create,
2029 .pre_destroy = mem_cgroup_pre_destroy,
2030 .destroy = mem_cgroup_destroy,
2031 .populate = mem_cgroup_populate,
2032 .attach = mem_cgroup_move_task,
2036 #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP
2038 static int __init disable_swap_account(char *s)
2040 really_do_swap_account = 0;
2043 __setup("noswapaccount", disable_swap_account);