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;
575 * Dance down the hierarchy if needed to reclaim memory. We remember the
576 * last child we reclaimed from, so that we don't end up penalizing
577 * one child extensively based on its position in the children list.
579 * root_mem is the original ancestor that we've been reclaim from.
581 static int mem_cgroup_hierarchical_reclaim(struct mem_cgroup *root_mem,
582 gfp_t gfp_mask, bool noswap)
584 struct mem_cgroup *next_mem;
588 * Reclaim unconditionally and don't check for return value.
589 * We need to reclaim in the current group and down the tree.
590 * One might think about checking for children before reclaiming,
591 * but there might be left over accounting, even after children
594 ret = try_to_free_mem_cgroup_pages(root_mem, gfp_mask, noswap);
595 if (res_counter_check_under_limit(&root_mem->res))
598 next_mem = mem_cgroup_get_first_node(root_mem);
600 while (next_mem != root_mem) {
601 if (next_mem->obsolete) {
602 mem_cgroup_put(next_mem);
604 next_mem = mem_cgroup_get_first_node(root_mem);
608 ret = try_to_free_mem_cgroup_pages(next_mem, gfp_mask, noswap);
609 if (res_counter_check_under_limit(&root_mem->res))
612 next_mem = mem_cgroup_get_next_node(next_mem, root_mem);
618 bool mem_cgroup_oom_called(struct task_struct *task)
621 struct mem_cgroup *mem;
622 struct mm_struct *mm;
628 mem = mem_cgroup_from_task(rcu_dereference(mm->owner));
629 if (mem && time_before(jiffies, mem->last_oom_jiffies + HZ/10))
635 * Unlike exported interface, "oom" parameter is added. if oom==true,
636 * oom-killer can be invoked.
638 static int __mem_cgroup_try_charge(struct mm_struct *mm,
639 gfp_t gfp_mask, struct mem_cgroup **memcg,
642 struct mem_cgroup *mem, *mem_over_limit;
643 int nr_retries = MEM_CGROUP_RECLAIM_RETRIES;
644 struct res_counter *fail_res;
646 if (unlikely(test_thread_flag(TIF_MEMDIE))) {
647 /* Don't account this! */
653 * We always charge the cgroup the mm_struct belongs to.
654 * The mm_struct's mem_cgroup changes on task migration if the
655 * thread group leader migrates. It's possible that mm is not
656 * set, if so charge the init_mm (happens for pagecache usage).
658 if (likely(!*memcg)) {
660 mem = mem_cgroup_from_task(rcu_dereference(mm->owner));
661 if (unlikely(!mem)) {
666 * For every charge from the cgroup, increment reference count
680 ret = res_counter_charge(&mem->res, PAGE_SIZE, &fail_res);
682 if (!do_swap_account)
684 ret = res_counter_charge(&mem->memsw, PAGE_SIZE,
688 /* mem+swap counter fails */
689 res_counter_uncharge(&mem->res, PAGE_SIZE);
691 mem_over_limit = mem_cgroup_from_res_counter(fail_res,
694 /* mem counter fails */
695 mem_over_limit = mem_cgroup_from_res_counter(fail_res,
698 if (!(gfp_mask & __GFP_WAIT))
701 ret = mem_cgroup_hierarchical_reclaim(mem_over_limit, gfp_mask,
705 * try_to_free_mem_cgroup_pages() might not give us a full
706 * picture of reclaim. Some pages are reclaimed and might be
707 * moved to swap cache or just unmapped from the cgroup.
708 * Check the limit again to see if the reclaim reduced the
709 * current usage of the cgroup before giving up
712 if (do_swap_account) {
713 if (res_counter_check_under_limit(&mem_over_limit->res) &&
714 res_counter_check_under_limit(&mem_over_limit->memsw))
716 } else if (res_counter_check_under_limit(&mem_over_limit->res))
721 mem_cgroup_out_of_memory(mem_over_limit, gfp_mask);
722 mem_over_limit->last_oom_jiffies = jiffies;
734 * mem_cgroup_try_charge - get charge of PAGE_SIZE.
735 * @mm: an mm_struct which is charged against. (when *memcg is NULL)
736 * @gfp_mask: gfp_mask for reclaim.
737 * @memcg: a pointer to memory cgroup which is charged against.
739 * charge against memory cgroup pointed by *memcg. if *memcg == NULL, estimated
740 * memory cgroup from @mm is got and stored in *memcg.
742 * Returns 0 if success. -ENOMEM at failure.
743 * This call can invoke OOM-Killer.
746 int mem_cgroup_try_charge(struct mm_struct *mm,
747 gfp_t mask, struct mem_cgroup **memcg)
749 return __mem_cgroup_try_charge(mm, mask, memcg, true);
753 * commit a charge got by mem_cgroup_try_charge() and makes page_cgroup to be
754 * USED state. If already USED, uncharge and return.
757 static void __mem_cgroup_commit_charge(struct mem_cgroup *mem,
758 struct page_cgroup *pc,
759 enum charge_type ctype)
761 /* try_charge() can return NULL to *memcg, taking care of it. */
765 lock_page_cgroup(pc);
766 if (unlikely(PageCgroupUsed(pc))) {
767 unlock_page_cgroup(pc);
768 res_counter_uncharge(&mem->res, PAGE_SIZE);
770 res_counter_uncharge(&mem->memsw, PAGE_SIZE);
774 pc->mem_cgroup = mem;
776 pc->flags = pcg_default_flags[ctype];
778 mem_cgroup_charge_statistics(mem, pc, true);
780 unlock_page_cgroup(pc);
784 * mem_cgroup_move_account - move account of the page
785 * @pc: page_cgroup of the page.
786 * @from: mem_cgroup which the page is moved from.
787 * @to: mem_cgroup which the page is moved to. @from != @to.
789 * The caller must confirm following.
790 * - page is not on LRU (isolate_page() is useful.)
792 * returns 0 at success,
793 * returns -EBUSY when lock is busy or "pc" is unstable.
795 * This function does "uncharge" from old cgroup but doesn't do "charge" to
796 * new cgroup. It should be done by a caller.
799 static int mem_cgroup_move_account(struct page_cgroup *pc,
800 struct mem_cgroup *from, struct mem_cgroup *to)
802 struct mem_cgroup_per_zone *from_mz, *to_mz;
806 VM_BUG_ON(from == to);
807 VM_BUG_ON(PageLRU(pc->page));
809 nid = page_cgroup_nid(pc);
810 zid = page_cgroup_zid(pc);
811 from_mz = mem_cgroup_zoneinfo(from, nid, zid);
812 to_mz = mem_cgroup_zoneinfo(to, nid, zid);
814 if (!trylock_page_cgroup(pc))
817 if (!PageCgroupUsed(pc))
820 if (pc->mem_cgroup != from)
824 res_counter_uncharge(&from->res, PAGE_SIZE);
825 mem_cgroup_charge_statistics(from, pc, false);
827 res_counter_uncharge(&from->memsw, PAGE_SIZE);
829 mem_cgroup_charge_statistics(to, pc, true);
833 unlock_page_cgroup(pc);
838 * move charges to its parent.
841 static int mem_cgroup_move_parent(struct page_cgroup *pc,
842 struct mem_cgroup *child,
845 struct page *page = pc->page;
846 struct cgroup *cg = child->css.cgroup;
847 struct cgroup *pcg = cg->parent;
848 struct mem_cgroup *parent;
856 parent = mem_cgroup_from_cont(pcg);
859 ret = __mem_cgroup_try_charge(NULL, gfp_mask, &parent, false);
863 if (!get_page_unless_zero(page))
866 ret = isolate_lru_page(page);
871 ret = mem_cgroup_move_account(pc, child, parent);
873 /* drop extra refcnt by try_charge() (move_account increment one) */
874 css_put(&parent->css);
875 putback_lru_page(page);
880 /* uncharge if move fails */
882 res_counter_uncharge(&parent->res, PAGE_SIZE);
884 res_counter_uncharge(&parent->memsw, PAGE_SIZE);
890 * Charge the memory controller for page usage.
892 * 0 if the charge was successful
893 * < 0 if the cgroup is over its limit
895 static int mem_cgroup_charge_common(struct page *page, struct mm_struct *mm,
896 gfp_t gfp_mask, enum charge_type ctype,
897 struct mem_cgroup *memcg)
899 struct mem_cgroup *mem;
900 struct page_cgroup *pc;
903 pc = lookup_page_cgroup(page);
904 /* can happen at boot */
910 ret = __mem_cgroup_try_charge(mm, gfp_mask, &mem, true);
914 __mem_cgroup_commit_charge(mem, pc, ctype);
918 int mem_cgroup_newpage_charge(struct page *page,
919 struct mm_struct *mm, gfp_t gfp_mask)
921 if (mem_cgroup_disabled())
923 if (PageCompound(page))
926 * If already mapped, we don't have to account.
927 * If page cache, page->mapping has address_space.
928 * But page->mapping may have out-of-use anon_vma pointer,
929 * detecit it by PageAnon() check. newly-mapped-anon's page->mapping
932 if (page_mapped(page) || (page->mapping && !PageAnon(page)))
936 return mem_cgroup_charge_common(page, mm, gfp_mask,
937 MEM_CGROUP_CHARGE_TYPE_MAPPED, NULL);
940 int mem_cgroup_cache_charge(struct page *page, struct mm_struct *mm,
943 if (mem_cgroup_disabled())
945 if (PageCompound(page))
948 * Corner case handling. This is called from add_to_page_cache()
949 * in usual. But some FS (shmem) precharges this page before calling it
950 * and call add_to_page_cache() with GFP_NOWAIT.
952 * For GFP_NOWAIT case, the page may be pre-charged before calling
953 * add_to_page_cache(). (See shmem.c) check it here and avoid to call
954 * charge twice. (It works but has to pay a bit larger cost.)
956 if (!(gfp_mask & __GFP_WAIT)) {
957 struct page_cgroup *pc;
960 pc = lookup_page_cgroup(page);
963 lock_page_cgroup(pc);
964 if (PageCgroupUsed(pc)) {
965 unlock_page_cgroup(pc);
968 unlock_page_cgroup(pc);
974 if (page_is_file_cache(page))
975 return mem_cgroup_charge_common(page, mm, gfp_mask,
976 MEM_CGROUP_CHARGE_TYPE_CACHE, NULL);
978 return mem_cgroup_charge_common(page, mm, gfp_mask,
979 MEM_CGROUP_CHARGE_TYPE_SHMEM, NULL);
982 int mem_cgroup_try_charge_swapin(struct mm_struct *mm,
984 gfp_t mask, struct mem_cgroup **ptr)
986 struct mem_cgroup *mem;
989 if (mem_cgroup_disabled())
992 if (!do_swap_account)
996 * A racing thread's fault, or swapoff, may have already updated
997 * the pte, and even removed page from swap cache: return success
998 * to go on to do_swap_page()'s pte_same() test, which should fail.
1000 if (!PageSwapCache(page))
1003 ent.val = page_private(page);
1005 mem = lookup_swap_cgroup(ent);
1006 if (!mem || mem->obsolete)
1009 return __mem_cgroup_try_charge(NULL, mask, ptr, true);
1013 return __mem_cgroup_try_charge(mm, mask, ptr, true);
1018 int mem_cgroup_cache_charge_swapin(struct page *page,
1019 struct mm_struct *mm, gfp_t mask, bool locked)
1023 if (mem_cgroup_disabled())
1030 * If not locked, the page can be dropped from SwapCache until
1033 if (PageSwapCache(page)) {
1034 struct mem_cgroup *mem = NULL;
1037 ent.val = page_private(page);
1038 if (do_swap_account) {
1039 mem = lookup_swap_cgroup(ent);
1040 if (mem && mem->obsolete)
1045 ret = mem_cgroup_charge_common(page, mm, mask,
1046 MEM_CGROUP_CHARGE_TYPE_SHMEM, mem);
1048 if (!ret && do_swap_account) {
1049 /* avoid double counting */
1050 mem = swap_cgroup_record(ent, NULL);
1052 res_counter_uncharge(&mem->memsw, PAGE_SIZE);
1053 mem_cgroup_put(mem);
1059 /* add this page(page_cgroup) to the LRU we want. */
1060 mem_cgroup_lru_fixup(page);
1066 void mem_cgroup_commit_charge_swapin(struct page *page, struct mem_cgroup *ptr)
1068 struct page_cgroup *pc;
1070 if (mem_cgroup_disabled())
1074 pc = lookup_page_cgroup(page);
1075 __mem_cgroup_commit_charge(ptr, pc, MEM_CGROUP_CHARGE_TYPE_MAPPED);
1077 * Now swap is on-memory. This means this page may be
1078 * counted both as mem and swap....double count.
1079 * Fix it by uncharging from memsw. This SwapCache is stable
1080 * because we're still under lock_page().
1082 if (do_swap_account) {
1083 swp_entry_t ent = {.val = page_private(page)};
1084 struct mem_cgroup *memcg;
1085 memcg = swap_cgroup_record(ent, NULL);
1087 /* If memcg is obsolete, memcg can be != ptr */
1088 res_counter_uncharge(&memcg->memsw, PAGE_SIZE);
1089 mem_cgroup_put(memcg);
1093 /* add this page(page_cgroup) to the LRU we want. */
1094 mem_cgroup_lru_fixup(page);
1097 void mem_cgroup_cancel_charge_swapin(struct mem_cgroup *mem)
1099 if (mem_cgroup_disabled())
1103 res_counter_uncharge(&mem->res, PAGE_SIZE);
1104 if (do_swap_account)
1105 res_counter_uncharge(&mem->memsw, PAGE_SIZE);
1111 * uncharge if !page_mapped(page)
1113 static struct mem_cgroup *
1114 __mem_cgroup_uncharge_common(struct page *page, enum charge_type ctype)
1116 struct page_cgroup *pc;
1117 struct mem_cgroup *mem = NULL;
1118 struct mem_cgroup_per_zone *mz;
1120 if (mem_cgroup_disabled())
1123 if (PageSwapCache(page))
1127 * Check if our page_cgroup is valid
1129 pc = lookup_page_cgroup(page);
1130 if (unlikely(!pc || !PageCgroupUsed(pc)))
1133 lock_page_cgroup(pc);
1135 mem = pc->mem_cgroup;
1137 if (!PageCgroupUsed(pc))
1141 case MEM_CGROUP_CHARGE_TYPE_MAPPED:
1142 if (page_mapped(page))
1145 case MEM_CGROUP_CHARGE_TYPE_SWAPOUT:
1146 if (!PageAnon(page)) { /* Shared memory */
1147 if (page->mapping && !page_is_file_cache(page))
1149 } else if (page_mapped(page)) /* Anon */
1156 res_counter_uncharge(&mem->res, PAGE_SIZE);
1157 if (do_swap_account && (ctype != MEM_CGROUP_CHARGE_TYPE_SWAPOUT))
1158 res_counter_uncharge(&mem->memsw, PAGE_SIZE);
1160 mem_cgroup_charge_statistics(mem, pc, false);
1161 ClearPageCgroupUsed(pc);
1163 mz = page_cgroup_zoneinfo(pc);
1164 unlock_page_cgroup(pc);
1171 unlock_page_cgroup(pc);
1175 void mem_cgroup_uncharge_page(struct page *page)
1178 if (page_mapped(page))
1180 if (page->mapping && !PageAnon(page))
1182 __mem_cgroup_uncharge_common(page, MEM_CGROUP_CHARGE_TYPE_MAPPED);
1185 void mem_cgroup_uncharge_cache_page(struct page *page)
1187 VM_BUG_ON(page_mapped(page));
1188 VM_BUG_ON(page->mapping);
1189 __mem_cgroup_uncharge_common(page, MEM_CGROUP_CHARGE_TYPE_CACHE);
1193 * called from __delete_from_swap_cache() and drop "page" account.
1194 * memcg information is recorded to swap_cgroup of "ent"
1196 void mem_cgroup_uncharge_swapcache(struct page *page, swp_entry_t ent)
1198 struct mem_cgroup *memcg;
1200 memcg = __mem_cgroup_uncharge_common(page,
1201 MEM_CGROUP_CHARGE_TYPE_SWAPOUT);
1202 /* record memcg information */
1203 if (do_swap_account && memcg) {
1204 swap_cgroup_record(ent, memcg);
1205 mem_cgroup_get(memcg);
1209 #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP
1211 * called from swap_entry_free(). remove record in swap_cgroup and
1212 * uncharge "memsw" account.
1214 void mem_cgroup_uncharge_swap(swp_entry_t ent)
1216 struct mem_cgroup *memcg;
1218 if (!do_swap_account)
1221 memcg = swap_cgroup_record(ent, NULL);
1223 res_counter_uncharge(&memcg->memsw, PAGE_SIZE);
1224 mem_cgroup_put(memcg);
1230 * Before starting migration, account PAGE_SIZE to mem_cgroup that the old
1233 int mem_cgroup_prepare_migration(struct page *page, struct mem_cgroup **ptr)
1235 struct page_cgroup *pc;
1236 struct mem_cgroup *mem = NULL;
1239 if (mem_cgroup_disabled())
1242 pc = lookup_page_cgroup(page);
1243 lock_page_cgroup(pc);
1244 if (PageCgroupUsed(pc)) {
1245 mem = pc->mem_cgroup;
1248 unlock_page_cgroup(pc);
1251 ret = mem_cgroup_try_charge(NULL, GFP_KERNEL, &mem);
1258 /* remove redundant charge if migration failed*/
1259 void mem_cgroup_end_migration(struct mem_cgroup *mem,
1260 struct page *oldpage, struct page *newpage)
1262 struct page *target, *unused;
1263 struct page_cgroup *pc;
1264 enum charge_type ctype;
1269 /* at migration success, oldpage->mapping is NULL. */
1270 if (oldpage->mapping) {
1278 if (PageAnon(target))
1279 ctype = MEM_CGROUP_CHARGE_TYPE_MAPPED;
1280 else if (page_is_file_cache(target))
1281 ctype = MEM_CGROUP_CHARGE_TYPE_CACHE;
1283 ctype = MEM_CGROUP_CHARGE_TYPE_SHMEM;
1285 /* unused page is not on radix-tree now. */
1287 __mem_cgroup_uncharge_common(unused, ctype);
1289 pc = lookup_page_cgroup(target);
1291 * __mem_cgroup_commit_charge() check PCG_USED bit of page_cgroup.
1292 * So, double-counting is effectively avoided.
1294 __mem_cgroup_commit_charge(mem, pc, ctype);
1297 * Both of oldpage and newpage are still under lock_page().
1298 * Then, we don't have to care about race in radix-tree.
1299 * But we have to be careful that this page is unmapped or not.
1301 * There is a case for !page_mapped(). At the start of
1302 * migration, oldpage was mapped. But now, it's zapped.
1303 * But we know *target* page is not freed/reused under us.
1304 * mem_cgroup_uncharge_page() does all necessary checks.
1306 if (ctype == MEM_CGROUP_CHARGE_TYPE_MAPPED)
1307 mem_cgroup_uncharge_page(target);
1311 * A call to try to shrink memory usage under specified resource controller.
1312 * This is typically used for page reclaiming for shmem for reducing side
1313 * effect of page allocation from shmem, which is used by some mem_cgroup.
1315 int mem_cgroup_shrink_usage(struct mm_struct *mm, gfp_t gfp_mask)
1317 struct mem_cgroup *mem;
1319 int retry = MEM_CGROUP_RECLAIM_RETRIES;
1321 if (mem_cgroup_disabled())
1327 mem = mem_cgroup_from_task(rcu_dereference(mm->owner));
1328 if (unlikely(!mem)) {
1336 progress = try_to_free_mem_cgroup_pages(mem, gfp_mask, true);
1337 progress += res_counter_check_under_limit(&mem->res);
1338 } while (!progress && --retry);
1346 static DEFINE_MUTEX(set_limit_mutex);
1348 static int mem_cgroup_resize_limit(struct mem_cgroup *memcg,
1349 unsigned long long val)
1352 int retry_count = MEM_CGROUP_RECLAIM_RETRIES;
1357 while (retry_count) {
1358 if (signal_pending(current)) {
1363 * Rather than hide all in some function, I do this in
1364 * open coded manner. You see what this really does.
1365 * We have to guarantee mem->res.limit < mem->memsw.limit.
1367 mutex_lock(&set_limit_mutex);
1368 memswlimit = res_counter_read_u64(&memcg->memsw, RES_LIMIT);
1369 if (memswlimit < val) {
1371 mutex_unlock(&set_limit_mutex);
1374 ret = res_counter_set_limit(&memcg->res, val);
1375 mutex_unlock(&set_limit_mutex);
1380 progress = try_to_free_mem_cgroup_pages(memcg,
1382 if (!progress) retry_count--;
1387 int mem_cgroup_resize_memsw_limit(struct mem_cgroup *memcg,
1388 unsigned long long val)
1390 int retry_count = MEM_CGROUP_RECLAIM_RETRIES;
1391 u64 memlimit, oldusage, curusage;
1394 if (!do_swap_account)
1397 while (retry_count) {
1398 if (signal_pending(current)) {
1403 * Rather than hide all in some function, I do this in
1404 * open coded manner. You see what this really does.
1405 * We have to guarantee mem->res.limit < mem->memsw.limit.
1407 mutex_lock(&set_limit_mutex);
1408 memlimit = res_counter_read_u64(&memcg->res, RES_LIMIT);
1409 if (memlimit > val) {
1411 mutex_unlock(&set_limit_mutex);
1414 ret = res_counter_set_limit(&memcg->memsw, val);
1415 mutex_unlock(&set_limit_mutex);
1420 oldusage = res_counter_read_u64(&memcg->memsw, RES_USAGE);
1421 try_to_free_mem_cgroup_pages(memcg, GFP_KERNEL, true);
1422 curusage = res_counter_read_u64(&memcg->memsw, RES_USAGE);
1423 if (curusage >= oldusage)
1430 * This routine traverse page_cgroup in given list and drop them all.
1431 * *And* this routine doesn't reclaim page itself, just removes page_cgroup.
1433 static int mem_cgroup_force_empty_list(struct mem_cgroup *mem,
1434 int node, int zid, enum lru_list lru)
1437 struct mem_cgroup_per_zone *mz;
1438 struct page_cgroup *pc, *busy;
1439 unsigned long flags, loop;
1440 struct list_head *list;
1443 zone = &NODE_DATA(node)->node_zones[zid];
1444 mz = mem_cgroup_zoneinfo(mem, node, zid);
1445 list = &mz->lists[lru];
1447 loop = MEM_CGROUP_ZSTAT(mz, lru);
1448 /* give some margin against EBUSY etc...*/
1453 spin_lock_irqsave(&zone->lru_lock, flags);
1454 if (list_empty(list)) {
1455 spin_unlock_irqrestore(&zone->lru_lock, flags);
1458 pc = list_entry(list->prev, struct page_cgroup, lru);
1460 list_move(&pc->lru, list);
1462 spin_unlock_irqrestore(&zone->lru_lock, flags);
1465 spin_unlock_irqrestore(&zone->lru_lock, flags);
1467 ret = mem_cgroup_move_parent(pc, mem, GFP_KERNEL);
1471 if (ret == -EBUSY || ret == -EINVAL) {
1472 /* found lock contention or "pc" is obsolete. */
1479 if (!ret && !list_empty(list))
1485 * make mem_cgroup's charge to be 0 if there is no task.
1486 * This enables deleting this mem_cgroup.
1488 static int mem_cgroup_force_empty(struct mem_cgroup *mem, bool free_all)
1491 int node, zid, shrink;
1492 int nr_retries = MEM_CGROUP_RECLAIM_RETRIES;
1493 struct cgroup *cgrp = mem->css.cgroup;
1498 /* should free all ? */
1502 while (mem->res.usage > 0) {
1504 if (cgroup_task_count(cgrp) || !list_empty(&cgrp->children))
1507 if (signal_pending(current))
1509 /* This is for making all *used* pages to be on LRU. */
1510 lru_add_drain_all();
1512 for_each_node_state(node, N_POSSIBLE) {
1513 for (zid = 0; !ret && zid < MAX_NR_ZONES; zid++) {
1516 ret = mem_cgroup_force_empty_list(mem,
1525 /* it seems parent cgroup doesn't have enough mem */
1536 /* returns EBUSY if there is a task or if we come here twice. */
1537 if (cgroup_task_count(cgrp) || !list_empty(&cgrp->children) || shrink) {
1541 /* we call try-to-free pages for make this cgroup empty */
1542 lru_add_drain_all();
1543 /* try to free all pages in this cgroup */
1545 while (nr_retries && mem->res.usage > 0) {
1548 if (signal_pending(current)) {
1552 progress = try_to_free_mem_cgroup_pages(mem,
1556 /* maybe some writeback is necessary */
1557 congestion_wait(WRITE, HZ/10);
1562 /* try move_account...there may be some *locked* pages. */
1569 int mem_cgroup_force_empty_write(struct cgroup *cont, unsigned int event)
1571 return mem_cgroup_force_empty(mem_cgroup_from_cont(cont), true);
1575 static u64 mem_cgroup_hierarchy_read(struct cgroup *cont, struct cftype *cft)
1577 return mem_cgroup_from_cont(cont)->use_hierarchy;
1580 static int mem_cgroup_hierarchy_write(struct cgroup *cont, struct cftype *cft,
1584 struct mem_cgroup *mem = mem_cgroup_from_cont(cont);
1585 struct cgroup *parent = cont->parent;
1586 struct mem_cgroup *parent_mem = NULL;
1589 parent_mem = mem_cgroup_from_cont(parent);
1593 * If parent's use_hiearchy is set, we can't make any modifications
1594 * in the child subtrees. If it is unset, then the change can
1595 * occur, provided the current cgroup has no children.
1597 * For the root cgroup, parent_mem is NULL, we allow value to be
1598 * set if there are no children.
1600 if ((!parent_mem || !parent_mem->use_hierarchy) &&
1601 (val == 1 || val == 0)) {
1602 if (list_empty(&cont->children))
1603 mem->use_hierarchy = val;
1613 static u64 mem_cgroup_read(struct cgroup *cont, struct cftype *cft)
1615 struct mem_cgroup *mem = mem_cgroup_from_cont(cont);
1619 type = MEMFILE_TYPE(cft->private);
1620 name = MEMFILE_ATTR(cft->private);
1623 val = res_counter_read_u64(&mem->res, name);
1626 if (do_swap_account)
1627 val = res_counter_read_u64(&mem->memsw, name);
1636 * The user of this function is...
1639 static int mem_cgroup_write(struct cgroup *cont, struct cftype *cft,
1642 struct mem_cgroup *memcg = mem_cgroup_from_cont(cont);
1644 unsigned long long val;
1647 type = MEMFILE_TYPE(cft->private);
1648 name = MEMFILE_ATTR(cft->private);
1651 /* This function does all necessary parse...reuse it */
1652 ret = res_counter_memparse_write_strategy(buffer, &val);
1656 ret = mem_cgroup_resize_limit(memcg, val);
1658 ret = mem_cgroup_resize_memsw_limit(memcg, val);
1661 ret = -EINVAL; /* should be BUG() ? */
1667 static int mem_cgroup_reset(struct cgroup *cont, unsigned int event)
1669 struct mem_cgroup *mem;
1672 mem = mem_cgroup_from_cont(cont);
1673 type = MEMFILE_TYPE(event);
1674 name = MEMFILE_ATTR(event);
1678 res_counter_reset_max(&mem->res);
1680 res_counter_reset_max(&mem->memsw);
1684 res_counter_reset_failcnt(&mem->res);
1686 res_counter_reset_failcnt(&mem->memsw);
1692 static const struct mem_cgroup_stat_desc {
1695 } mem_cgroup_stat_desc[] = {
1696 [MEM_CGROUP_STAT_CACHE] = { "cache", PAGE_SIZE, },
1697 [MEM_CGROUP_STAT_RSS] = { "rss", PAGE_SIZE, },
1698 [MEM_CGROUP_STAT_PGPGIN_COUNT] = {"pgpgin", 1, },
1699 [MEM_CGROUP_STAT_PGPGOUT_COUNT] = {"pgpgout", 1, },
1702 static int mem_control_stat_show(struct cgroup *cont, struct cftype *cft,
1703 struct cgroup_map_cb *cb)
1705 struct mem_cgroup *mem_cont = mem_cgroup_from_cont(cont);
1706 struct mem_cgroup_stat *stat = &mem_cont->stat;
1709 for (i = 0; i < ARRAY_SIZE(stat->cpustat[0].count); i++) {
1712 val = mem_cgroup_read_stat(stat, i);
1713 val *= mem_cgroup_stat_desc[i].unit;
1714 cb->fill(cb, mem_cgroup_stat_desc[i].msg, val);
1716 /* showing # of active pages */
1718 unsigned long active_anon, inactive_anon;
1719 unsigned long active_file, inactive_file;
1720 unsigned long unevictable;
1722 inactive_anon = mem_cgroup_get_all_zonestat(mem_cont,
1724 active_anon = mem_cgroup_get_all_zonestat(mem_cont,
1726 inactive_file = mem_cgroup_get_all_zonestat(mem_cont,
1728 active_file = mem_cgroup_get_all_zonestat(mem_cont,
1730 unevictable = mem_cgroup_get_all_zonestat(mem_cont,
1733 cb->fill(cb, "active_anon", (active_anon) * PAGE_SIZE);
1734 cb->fill(cb, "inactive_anon", (inactive_anon) * PAGE_SIZE);
1735 cb->fill(cb, "active_file", (active_file) * PAGE_SIZE);
1736 cb->fill(cb, "inactive_file", (inactive_file) * PAGE_SIZE);
1737 cb->fill(cb, "unevictable", unevictable * PAGE_SIZE);
1744 static struct cftype mem_cgroup_files[] = {
1746 .name = "usage_in_bytes",
1747 .private = MEMFILE_PRIVATE(_MEM, RES_USAGE),
1748 .read_u64 = mem_cgroup_read,
1751 .name = "max_usage_in_bytes",
1752 .private = MEMFILE_PRIVATE(_MEM, RES_MAX_USAGE),
1753 .trigger = mem_cgroup_reset,
1754 .read_u64 = mem_cgroup_read,
1757 .name = "limit_in_bytes",
1758 .private = MEMFILE_PRIVATE(_MEM, RES_LIMIT),
1759 .write_string = mem_cgroup_write,
1760 .read_u64 = mem_cgroup_read,
1764 .private = MEMFILE_PRIVATE(_MEM, RES_FAILCNT),
1765 .trigger = mem_cgroup_reset,
1766 .read_u64 = mem_cgroup_read,
1770 .read_map = mem_control_stat_show,
1773 .name = "force_empty",
1774 .trigger = mem_cgroup_force_empty_write,
1777 .name = "use_hierarchy",
1778 .write_u64 = mem_cgroup_hierarchy_write,
1779 .read_u64 = mem_cgroup_hierarchy_read,
1783 #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP
1784 static struct cftype memsw_cgroup_files[] = {
1786 .name = "memsw.usage_in_bytes",
1787 .private = MEMFILE_PRIVATE(_MEMSWAP, RES_USAGE),
1788 .read_u64 = mem_cgroup_read,
1791 .name = "memsw.max_usage_in_bytes",
1792 .private = MEMFILE_PRIVATE(_MEMSWAP, RES_MAX_USAGE),
1793 .trigger = mem_cgroup_reset,
1794 .read_u64 = mem_cgroup_read,
1797 .name = "memsw.limit_in_bytes",
1798 .private = MEMFILE_PRIVATE(_MEMSWAP, RES_LIMIT),
1799 .write_string = mem_cgroup_write,
1800 .read_u64 = mem_cgroup_read,
1803 .name = "memsw.failcnt",
1804 .private = MEMFILE_PRIVATE(_MEMSWAP, RES_FAILCNT),
1805 .trigger = mem_cgroup_reset,
1806 .read_u64 = mem_cgroup_read,
1810 static int register_memsw_files(struct cgroup *cont, struct cgroup_subsys *ss)
1812 if (!do_swap_account)
1814 return cgroup_add_files(cont, ss, memsw_cgroup_files,
1815 ARRAY_SIZE(memsw_cgroup_files));
1818 static int register_memsw_files(struct cgroup *cont, struct cgroup_subsys *ss)
1824 static int alloc_mem_cgroup_per_zone_info(struct mem_cgroup *mem, int node)
1826 struct mem_cgroup_per_node *pn;
1827 struct mem_cgroup_per_zone *mz;
1829 int zone, tmp = node;
1831 * This routine is called against possible nodes.
1832 * But it's BUG to call kmalloc() against offline node.
1834 * TODO: this routine can waste much memory for nodes which will
1835 * never be onlined. It's better to use memory hotplug callback
1838 if (!node_state(node, N_NORMAL_MEMORY))
1840 pn = kmalloc_node(sizeof(*pn), GFP_KERNEL, tmp);
1844 mem->info.nodeinfo[node] = pn;
1845 memset(pn, 0, sizeof(*pn));
1847 for (zone = 0; zone < MAX_NR_ZONES; zone++) {
1848 mz = &pn->zoneinfo[zone];
1850 INIT_LIST_HEAD(&mz->lists[l]);
1855 static void free_mem_cgroup_per_zone_info(struct mem_cgroup *mem, int node)
1857 kfree(mem->info.nodeinfo[node]);
1860 static int mem_cgroup_size(void)
1862 int cpustat_size = nr_cpu_ids * sizeof(struct mem_cgroup_stat_cpu);
1863 return sizeof(struct mem_cgroup) + cpustat_size;
1866 static struct mem_cgroup *mem_cgroup_alloc(void)
1868 struct mem_cgroup *mem;
1869 int size = mem_cgroup_size();
1871 if (size < PAGE_SIZE)
1872 mem = kmalloc(size, GFP_KERNEL);
1874 mem = vmalloc(size);
1877 memset(mem, 0, size);
1882 * At destroying mem_cgroup, references from swap_cgroup can remain.
1883 * (scanning all at force_empty is too costly...)
1885 * Instead of clearing all references at force_empty, we remember
1886 * the number of reference from swap_cgroup and free mem_cgroup when
1887 * it goes down to 0.
1889 * When mem_cgroup is destroyed, mem->obsolete will be set to 0 and
1890 * entry which points to this memcg will be ignore at swapin.
1892 * Removal of cgroup itself succeeds regardless of refs from swap.
1895 static void mem_cgroup_free(struct mem_cgroup *mem)
1899 if (atomic_read(&mem->refcnt) > 0)
1903 for_each_node_state(node, N_POSSIBLE)
1904 free_mem_cgroup_per_zone_info(mem, node);
1906 if (mem_cgroup_size() < PAGE_SIZE)
1912 static void mem_cgroup_get(struct mem_cgroup *mem)
1914 atomic_inc(&mem->refcnt);
1917 static void mem_cgroup_put(struct mem_cgroup *mem)
1919 if (atomic_dec_and_test(&mem->refcnt)) {
1922 mem_cgroup_free(mem);
1927 #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP
1928 static void __init enable_swap_cgroup(void)
1930 if (!mem_cgroup_disabled() && really_do_swap_account)
1931 do_swap_account = 1;
1934 static void __init enable_swap_cgroup(void)
1939 static struct cgroup_subsys_state *
1940 mem_cgroup_create(struct cgroup_subsys *ss, struct cgroup *cont)
1942 struct mem_cgroup *mem, *parent;
1945 mem = mem_cgroup_alloc();
1947 return ERR_PTR(-ENOMEM);
1949 for_each_node_state(node, N_POSSIBLE)
1950 if (alloc_mem_cgroup_per_zone_info(mem, node))
1953 if (cont->parent == NULL) {
1954 enable_swap_cgroup();
1957 parent = mem_cgroup_from_cont(cont->parent);
1958 mem->use_hierarchy = parent->use_hierarchy;
1961 if (parent && parent->use_hierarchy) {
1962 res_counter_init(&mem->res, &parent->res);
1963 res_counter_init(&mem->memsw, &parent->memsw);
1965 res_counter_init(&mem->res, NULL);
1966 res_counter_init(&mem->memsw, NULL);
1969 mem->last_scanned_child = NULL;
1973 for_each_node_state(node, N_POSSIBLE)
1974 free_mem_cgroup_per_zone_info(mem, node);
1975 mem_cgroup_free(mem);
1976 return ERR_PTR(-ENOMEM);
1979 static void mem_cgroup_pre_destroy(struct cgroup_subsys *ss,
1980 struct cgroup *cont)
1982 struct mem_cgroup *mem = mem_cgroup_from_cont(cont);
1984 mem_cgroup_force_empty(mem, false);
1987 static void mem_cgroup_destroy(struct cgroup_subsys *ss,
1988 struct cgroup *cont)
1990 mem_cgroup_free(mem_cgroup_from_cont(cont));
1993 static int mem_cgroup_populate(struct cgroup_subsys *ss,
1994 struct cgroup *cont)
1998 ret = cgroup_add_files(cont, ss, mem_cgroup_files,
1999 ARRAY_SIZE(mem_cgroup_files));
2002 ret = register_memsw_files(cont, ss);
2006 static void mem_cgroup_move_task(struct cgroup_subsys *ss,
2007 struct cgroup *cont,
2008 struct cgroup *old_cont,
2009 struct task_struct *p)
2011 struct mm_struct *mm;
2012 struct mem_cgroup *mem, *old_mem;
2014 mm = get_task_mm(p);
2018 mem = mem_cgroup_from_cont(cont);
2019 old_mem = mem_cgroup_from_cont(old_cont);
2022 * Only thread group leaders are allowed to migrate, the mm_struct is
2023 * in effect owned by the leader
2025 if (!thread_group_leader(p))
2032 struct cgroup_subsys mem_cgroup_subsys = {
2034 .subsys_id = mem_cgroup_subsys_id,
2035 .create = mem_cgroup_create,
2036 .pre_destroy = mem_cgroup_pre_destroy,
2037 .destroy = mem_cgroup_destroy,
2038 .populate = mem_cgroup_populate,
2039 .attach = mem_cgroup_move_task,
2043 #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP
2045 static int __init disable_swap_account(char *s)
2047 really_do_swap_account = 0;
2050 __setup("noswapaccount", disable_swap_account);