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)
54 static DEFINE_MUTEX(memcg_tasklist); /* can be hold under cgroup_mutex */
57 * Statistics for memory cgroup.
59 enum mem_cgroup_stat_index {
61 * For MEM_CONTAINER_TYPE_ALL, usage = pagecache + rss.
63 MEM_CGROUP_STAT_CACHE, /* # of pages charged as cache */
64 MEM_CGROUP_STAT_RSS, /* # of pages charged as rss */
65 MEM_CGROUP_STAT_PGPGIN_COUNT, /* # of pages paged in */
66 MEM_CGROUP_STAT_PGPGOUT_COUNT, /* # of pages paged out */
68 MEM_CGROUP_STAT_NSTATS,
71 struct mem_cgroup_stat_cpu {
72 s64 count[MEM_CGROUP_STAT_NSTATS];
73 } ____cacheline_aligned_in_smp;
75 struct mem_cgroup_stat {
76 struct mem_cgroup_stat_cpu cpustat[0];
80 * For accounting under irq disable, no need for increment preempt count.
82 static inline void __mem_cgroup_stat_add_safe(struct mem_cgroup_stat_cpu *stat,
83 enum mem_cgroup_stat_index idx, int val)
85 stat->count[idx] += val;
88 static s64 mem_cgroup_read_stat(struct mem_cgroup_stat *stat,
89 enum mem_cgroup_stat_index idx)
93 for_each_possible_cpu(cpu)
94 ret += stat->cpustat[cpu].count[idx];
99 * per-zone information in memory controller.
101 struct mem_cgroup_per_zone {
103 * spin_lock to protect the per cgroup LRU
105 struct list_head lists[NR_LRU_LISTS];
106 unsigned long count[NR_LRU_LISTS];
108 struct zone_reclaim_stat reclaim_stat;
110 /* Macro for accessing counter */
111 #define MEM_CGROUP_ZSTAT(mz, idx) ((mz)->count[(idx)])
113 struct mem_cgroup_per_node {
114 struct mem_cgroup_per_zone zoneinfo[MAX_NR_ZONES];
117 struct mem_cgroup_lru_info {
118 struct mem_cgroup_per_node *nodeinfo[MAX_NUMNODES];
122 * The memory controller data structure. The memory controller controls both
123 * page cache and RSS per cgroup. We would eventually like to provide
124 * statistics based on the statistics developed by Rik Van Riel for clock-pro,
125 * to help the administrator determine what knobs to tune.
127 * TODO: Add a water mark for the memory controller. Reclaim will begin when
128 * we hit the water mark. May be even add a low water mark, such that
129 * no reclaim occurs from a cgroup at it's low water mark, this is
130 * a feature that will be implemented much later in the future.
133 struct cgroup_subsys_state css;
135 * the counter to account for memory usage
137 struct res_counter res;
139 * the counter to account for mem+swap usage.
141 struct res_counter memsw;
143 * Per cgroup active and inactive list, similar to the
144 * per zone LRU lists.
146 struct mem_cgroup_lru_info info;
149 protect against reclaim related member.
151 spinlock_t reclaim_param_lock;
153 int prev_priority; /* for recording reclaim priority */
156 * While reclaiming in a hiearchy, we cache the last child we
157 * reclaimed from. Protected by hierarchy_mutex
159 struct mem_cgroup *last_scanned_child;
161 * Should the accounting and control be hierarchical, per subtree?
164 unsigned long last_oom_jiffies;
167 unsigned int swappiness;
170 * statistics. This must be placed at the end of memcg.
172 struct mem_cgroup_stat stat;
176 MEM_CGROUP_CHARGE_TYPE_CACHE = 0,
177 MEM_CGROUP_CHARGE_TYPE_MAPPED,
178 MEM_CGROUP_CHARGE_TYPE_SHMEM, /* used by page migration of shmem */
179 MEM_CGROUP_CHARGE_TYPE_FORCE, /* used by force_empty */
180 MEM_CGROUP_CHARGE_TYPE_SWAPOUT, /* for accounting swapcache */
184 /* only for here (for easy reading.) */
185 #define PCGF_CACHE (1UL << PCG_CACHE)
186 #define PCGF_USED (1UL << PCG_USED)
187 #define PCGF_LOCK (1UL << PCG_LOCK)
188 static const unsigned long
189 pcg_default_flags[NR_CHARGE_TYPE] = {
190 PCGF_CACHE | PCGF_USED | PCGF_LOCK, /* File Cache */
191 PCGF_USED | PCGF_LOCK, /* Anon */
192 PCGF_CACHE | PCGF_USED | PCGF_LOCK, /* Shmem */
196 /* for encoding cft->private value on file */
199 #define MEMFILE_PRIVATE(x, val) (((x) << 16) | (val))
200 #define MEMFILE_TYPE(val) (((val) >> 16) & 0xffff)
201 #define MEMFILE_ATTR(val) ((val) & 0xffff)
203 static void mem_cgroup_get(struct mem_cgroup *mem);
204 static void mem_cgroup_put(struct mem_cgroup *mem);
206 static void mem_cgroup_charge_statistics(struct mem_cgroup *mem,
207 struct page_cgroup *pc,
210 int val = (charge)? 1 : -1;
211 struct mem_cgroup_stat *stat = &mem->stat;
212 struct mem_cgroup_stat_cpu *cpustat;
215 cpustat = &stat->cpustat[cpu];
216 if (PageCgroupCache(pc))
217 __mem_cgroup_stat_add_safe(cpustat, MEM_CGROUP_STAT_CACHE, val);
219 __mem_cgroup_stat_add_safe(cpustat, MEM_CGROUP_STAT_RSS, val);
222 __mem_cgroup_stat_add_safe(cpustat,
223 MEM_CGROUP_STAT_PGPGIN_COUNT, 1);
225 __mem_cgroup_stat_add_safe(cpustat,
226 MEM_CGROUP_STAT_PGPGOUT_COUNT, 1);
230 static struct mem_cgroup_per_zone *
231 mem_cgroup_zoneinfo(struct mem_cgroup *mem, int nid, int zid)
233 return &mem->info.nodeinfo[nid]->zoneinfo[zid];
236 static struct mem_cgroup_per_zone *
237 page_cgroup_zoneinfo(struct page_cgroup *pc)
239 struct mem_cgroup *mem = pc->mem_cgroup;
240 int nid = page_cgroup_nid(pc);
241 int zid = page_cgroup_zid(pc);
246 return mem_cgroup_zoneinfo(mem, nid, zid);
249 static unsigned long mem_cgroup_get_all_zonestat(struct mem_cgroup *mem,
253 struct mem_cgroup_per_zone *mz;
256 for_each_online_node(nid)
257 for (zid = 0; zid < MAX_NR_ZONES; zid++) {
258 mz = mem_cgroup_zoneinfo(mem, nid, zid);
259 total += MEM_CGROUP_ZSTAT(mz, idx);
264 static struct mem_cgroup *mem_cgroup_from_cont(struct cgroup *cont)
266 return container_of(cgroup_subsys_state(cont,
267 mem_cgroup_subsys_id), struct mem_cgroup,
271 struct mem_cgroup *mem_cgroup_from_task(struct task_struct *p)
274 * mm_update_next_owner() may clear mm->owner to NULL
275 * if it races with swapoff, page migration, etc.
276 * So this can be called with p == NULL.
281 return container_of(task_subsys_state(p, mem_cgroup_subsys_id),
282 struct mem_cgroup, css);
285 static struct mem_cgroup *try_get_mem_cgroup_from_mm(struct mm_struct *mm)
287 struct mem_cgroup *mem = NULL;
289 * Because we have no locks, mm->owner's may be being moved to other
290 * cgroup. We use css_tryget() here even if this looks
291 * pessimistic (rather than adding locks here).
295 mem = mem_cgroup_from_task(rcu_dereference(mm->owner));
298 } while (!css_tryget(&mem->css));
303 static bool mem_cgroup_is_obsolete(struct mem_cgroup *mem)
307 return css_is_removed(&mem->css);
311 * Following LRU functions are allowed to be used without PCG_LOCK.
312 * Operations are called by routine of global LRU independently from memcg.
313 * What we have to take care of here is validness of pc->mem_cgroup.
315 * Changes to pc->mem_cgroup happens when
318 * In typical case, "charge" is done before add-to-lru. Exception is SwapCache.
319 * It is added to LRU before charge.
320 * If PCG_USED bit is not set, page_cgroup is not added to this private LRU.
321 * When moving account, the page is not on LRU. It's isolated.
324 void mem_cgroup_del_lru_list(struct page *page, enum lru_list lru)
326 struct page_cgroup *pc;
327 struct mem_cgroup *mem;
328 struct mem_cgroup_per_zone *mz;
330 if (mem_cgroup_disabled())
332 pc = lookup_page_cgroup(page);
333 /* can happen while we handle swapcache. */
334 if (list_empty(&pc->lru) || !pc->mem_cgroup)
337 * We don't check PCG_USED bit. It's cleared when the "page" is finally
338 * removed from global LRU.
340 mz = page_cgroup_zoneinfo(pc);
341 mem = pc->mem_cgroup;
342 MEM_CGROUP_ZSTAT(mz, lru) -= 1;
343 list_del_init(&pc->lru);
347 void mem_cgroup_del_lru(struct page *page)
349 mem_cgroup_del_lru_list(page, page_lru(page));
352 void mem_cgroup_rotate_lru_list(struct page *page, enum lru_list lru)
354 struct mem_cgroup_per_zone *mz;
355 struct page_cgroup *pc;
357 if (mem_cgroup_disabled())
360 pc = lookup_page_cgroup(page);
362 * Used bit is set without atomic ops but after smp_wmb().
363 * For making pc->mem_cgroup visible, insert smp_rmb() here.
366 /* unused page is not rotated. */
367 if (!PageCgroupUsed(pc))
369 mz = page_cgroup_zoneinfo(pc);
370 list_move(&pc->lru, &mz->lists[lru]);
373 void mem_cgroup_add_lru_list(struct page *page, enum lru_list lru)
375 struct page_cgroup *pc;
376 struct mem_cgroup_per_zone *mz;
378 if (mem_cgroup_disabled())
380 pc = lookup_page_cgroup(page);
382 * Used bit is set without atomic ops but after smp_wmb().
383 * For making pc->mem_cgroup visible, insert smp_rmb() here.
386 if (!PageCgroupUsed(pc))
389 mz = page_cgroup_zoneinfo(pc);
390 MEM_CGROUP_ZSTAT(mz, lru) += 1;
391 list_add(&pc->lru, &mz->lists[lru]);
395 * At handling SwapCache, pc->mem_cgroup may be changed while it's linked to
396 * lru because the page may.be reused after it's fully uncharged (because of
397 * SwapCache behavior).To handle that, unlink page_cgroup from LRU when charge
398 * it again. This function is only used to charge SwapCache. It's done under
399 * lock_page and expected that zone->lru_lock is never held.
401 static void mem_cgroup_lru_del_before_commit_swapcache(struct page *page)
404 struct zone *zone = page_zone(page);
405 struct page_cgroup *pc = lookup_page_cgroup(page);
407 spin_lock_irqsave(&zone->lru_lock, flags);
409 * Forget old LRU when this page_cgroup is *not* used. This Used bit
410 * is guarded by lock_page() because the page is SwapCache.
412 if (!PageCgroupUsed(pc))
413 mem_cgroup_del_lru_list(page, page_lru(page));
414 spin_unlock_irqrestore(&zone->lru_lock, flags);
417 static void mem_cgroup_lru_add_after_commit_swapcache(struct page *page)
420 struct zone *zone = page_zone(page);
421 struct page_cgroup *pc = lookup_page_cgroup(page);
423 spin_lock_irqsave(&zone->lru_lock, flags);
424 /* link when the page is linked to LRU but page_cgroup isn't */
425 if (PageLRU(page) && list_empty(&pc->lru))
426 mem_cgroup_add_lru_list(page, page_lru(page));
427 spin_unlock_irqrestore(&zone->lru_lock, flags);
431 void mem_cgroup_move_lists(struct page *page,
432 enum lru_list from, enum lru_list to)
434 if (mem_cgroup_disabled())
436 mem_cgroup_del_lru_list(page, from);
437 mem_cgroup_add_lru_list(page, to);
440 int task_in_mem_cgroup(struct task_struct *task, const struct mem_cgroup *mem)
445 ret = task->mm && mm_match_cgroup(task->mm, mem);
451 * Calculate mapped_ratio under memory controller. This will be used in
452 * vmscan.c for deteremining we have to reclaim mapped pages.
454 int mem_cgroup_calc_mapped_ratio(struct mem_cgroup *mem)
459 * usage is recorded in bytes. But, here, we assume the number of
460 * physical pages can be represented by "long" on any arch.
462 total = (long) (mem->res.usage >> PAGE_SHIFT) + 1L;
463 rss = (long)mem_cgroup_read_stat(&mem->stat, MEM_CGROUP_STAT_RSS);
464 return (int)((rss * 100L) / total);
468 * prev_priority control...this will be used in memory reclaim path.
470 int mem_cgroup_get_reclaim_priority(struct mem_cgroup *mem)
474 spin_lock(&mem->reclaim_param_lock);
475 prev_priority = mem->prev_priority;
476 spin_unlock(&mem->reclaim_param_lock);
478 return prev_priority;
481 void mem_cgroup_note_reclaim_priority(struct mem_cgroup *mem, int priority)
483 spin_lock(&mem->reclaim_param_lock);
484 if (priority < mem->prev_priority)
485 mem->prev_priority = priority;
486 spin_unlock(&mem->reclaim_param_lock);
489 void mem_cgroup_record_reclaim_priority(struct mem_cgroup *mem, int priority)
491 spin_lock(&mem->reclaim_param_lock);
492 mem->prev_priority = priority;
493 spin_unlock(&mem->reclaim_param_lock);
496 static int calc_inactive_ratio(struct mem_cgroup *memcg, unsigned long *present_pages)
498 unsigned long active;
499 unsigned long inactive;
501 unsigned long inactive_ratio;
503 inactive = mem_cgroup_get_all_zonestat(memcg, LRU_INACTIVE_ANON);
504 active = mem_cgroup_get_all_zonestat(memcg, LRU_ACTIVE_ANON);
506 gb = (inactive + active) >> (30 - PAGE_SHIFT);
508 inactive_ratio = int_sqrt(10 * gb);
513 present_pages[0] = inactive;
514 present_pages[1] = active;
517 return inactive_ratio;
520 int mem_cgroup_inactive_anon_is_low(struct mem_cgroup *memcg)
522 unsigned long active;
523 unsigned long inactive;
524 unsigned long present_pages[2];
525 unsigned long inactive_ratio;
527 inactive_ratio = calc_inactive_ratio(memcg, present_pages);
529 inactive = present_pages[0];
530 active = present_pages[1];
532 if (inactive * inactive_ratio < active)
538 unsigned long mem_cgroup_zone_nr_pages(struct mem_cgroup *memcg,
542 int nid = zone->zone_pgdat->node_id;
543 int zid = zone_idx(zone);
544 struct mem_cgroup_per_zone *mz = mem_cgroup_zoneinfo(memcg, nid, zid);
546 return MEM_CGROUP_ZSTAT(mz, lru);
549 struct zone_reclaim_stat *mem_cgroup_get_reclaim_stat(struct mem_cgroup *memcg,
552 int nid = zone->zone_pgdat->node_id;
553 int zid = zone_idx(zone);
554 struct mem_cgroup_per_zone *mz = mem_cgroup_zoneinfo(memcg, nid, zid);
556 return &mz->reclaim_stat;
559 struct zone_reclaim_stat *
560 mem_cgroup_get_reclaim_stat_from_page(struct page *page)
562 struct page_cgroup *pc;
563 struct mem_cgroup_per_zone *mz;
565 if (mem_cgroup_disabled())
568 pc = lookup_page_cgroup(page);
570 * Used bit is set without atomic ops but after smp_wmb().
571 * For making pc->mem_cgroup visible, insert smp_rmb() here.
574 if (!PageCgroupUsed(pc))
577 mz = page_cgroup_zoneinfo(pc);
581 return &mz->reclaim_stat;
584 unsigned long mem_cgroup_isolate_pages(unsigned long nr_to_scan,
585 struct list_head *dst,
586 unsigned long *scanned, int order,
587 int mode, struct zone *z,
588 struct mem_cgroup *mem_cont,
589 int active, int file)
591 unsigned long nr_taken = 0;
595 struct list_head *src;
596 struct page_cgroup *pc, *tmp;
597 int nid = z->zone_pgdat->node_id;
598 int zid = zone_idx(z);
599 struct mem_cgroup_per_zone *mz;
600 int lru = LRU_FILE * !!file + !!active;
603 mz = mem_cgroup_zoneinfo(mem_cont, nid, zid);
604 src = &mz->lists[lru];
607 list_for_each_entry_safe_reverse(pc, tmp, src, lru) {
608 if (scan >= nr_to_scan)
612 if (unlikely(!PageCgroupUsed(pc)))
614 if (unlikely(!PageLRU(page)))
618 if (__isolate_lru_page(page, mode, file) == 0) {
619 list_move(&page->lru, dst);
628 #define mem_cgroup_from_res_counter(counter, member) \
629 container_of(counter, struct mem_cgroup, member)
632 * This routine finds the DFS walk successor. This routine should be
633 * called with hierarchy_mutex held
635 static struct mem_cgroup *
636 mem_cgroup_get_next_node(struct mem_cgroup *curr, struct mem_cgroup *root_mem)
638 struct cgroup *cgroup, *curr_cgroup, *root_cgroup;
640 curr_cgroup = curr->css.cgroup;
641 root_cgroup = root_mem->css.cgroup;
643 if (!list_empty(&curr_cgroup->children)) {
645 * Walk down to children
647 mem_cgroup_put(curr);
648 cgroup = list_entry(curr_cgroup->children.next,
649 struct cgroup, sibling);
650 curr = mem_cgroup_from_cont(cgroup);
651 mem_cgroup_get(curr);
656 if (curr_cgroup == root_cgroup) {
657 mem_cgroup_put(curr);
659 mem_cgroup_get(curr);
666 if (curr_cgroup->sibling.next != &curr_cgroup->parent->children) {
667 mem_cgroup_put(curr);
668 cgroup = list_entry(curr_cgroup->sibling.next, struct cgroup,
670 curr = mem_cgroup_from_cont(cgroup);
671 mem_cgroup_get(curr);
676 * Go up to next parent and next parent's sibling if need be
678 curr_cgroup = curr_cgroup->parent;
682 root_mem->last_scanned_child = curr;
687 * Visit the first child (need not be the first child as per the ordering
688 * of the cgroup list, since we track last_scanned_child) of @mem and use
689 * that to reclaim free pages from.
691 static struct mem_cgroup *
692 mem_cgroup_get_first_node(struct mem_cgroup *root_mem)
694 struct cgroup *cgroup;
695 struct mem_cgroup *ret;
698 obsolete = mem_cgroup_is_obsolete(root_mem->last_scanned_child);
701 * Scan all children under the mem_cgroup mem
703 mutex_lock(&mem_cgroup_subsys.hierarchy_mutex);
704 if (list_empty(&root_mem->css.cgroup->children)) {
709 if (!root_mem->last_scanned_child || obsolete) {
711 if (obsolete && root_mem->last_scanned_child)
712 mem_cgroup_put(root_mem->last_scanned_child);
714 cgroup = list_first_entry(&root_mem->css.cgroup->children,
715 struct cgroup, sibling);
716 ret = mem_cgroup_from_cont(cgroup);
719 ret = mem_cgroup_get_next_node(root_mem->last_scanned_child,
723 root_mem->last_scanned_child = ret;
724 mutex_unlock(&mem_cgroup_subsys.hierarchy_mutex);
728 static bool mem_cgroup_check_under_limit(struct mem_cgroup *mem)
730 if (do_swap_account) {
731 if (res_counter_check_under_limit(&mem->res) &&
732 res_counter_check_under_limit(&mem->memsw))
735 if (res_counter_check_under_limit(&mem->res))
740 static unsigned int get_swappiness(struct mem_cgroup *memcg)
742 struct cgroup *cgrp = memcg->css.cgroup;
743 unsigned int swappiness;
746 if (cgrp->parent == NULL)
747 return vm_swappiness;
749 spin_lock(&memcg->reclaim_param_lock);
750 swappiness = memcg->swappiness;
751 spin_unlock(&memcg->reclaim_param_lock);
757 * Dance down the hierarchy if needed to reclaim memory. We remember the
758 * last child we reclaimed from, so that we don't end up penalizing
759 * one child extensively based on its position in the children list.
761 * root_mem is the original ancestor that we've been reclaim from.
763 static int mem_cgroup_hierarchical_reclaim(struct mem_cgroup *root_mem,
764 gfp_t gfp_mask, bool noswap)
766 struct mem_cgroup *next_mem;
770 * Reclaim unconditionally and don't check for return value.
771 * We need to reclaim in the current group and down the tree.
772 * One might think about checking for children before reclaiming,
773 * but there might be left over accounting, even after children
776 ret = try_to_free_mem_cgroup_pages(root_mem, gfp_mask, noswap,
777 get_swappiness(root_mem));
778 if (mem_cgroup_check_under_limit(root_mem))
780 if (!root_mem->use_hierarchy)
783 next_mem = mem_cgroup_get_first_node(root_mem);
785 while (next_mem != root_mem) {
786 if (mem_cgroup_is_obsolete(next_mem)) {
787 mem_cgroup_put(next_mem);
788 next_mem = mem_cgroup_get_first_node(root_mem);
791 ret = try_to_free_mem_cgroup_pages(next_mem, gfp_mask, noswap,
792 get_swappiness(next_mem));
793 if (mem_cgroup_check_under_limit(root_mem))
795 mutex_lock(&mem_cgroup_subsys.hierarchy_mutex);
796 next_mem = mem_cgroup_get_next_node(next_mem, root_mem);
797 mutex_unlock(&mem_cgroup_subsys.hierarchy_mutex);
802 bool mem_cgroup_oom_called(struct task_struct *task)
805 struct mem_cgroup *mem;
806 struct mm_struct *mm;
812 mem = mem_cgroup_from_task(rcu_dereference(mm->owner));
813 if (mem && time_before(jiffies, mem->last_oom_jiffies + HZ/10))
819 * Unlike exported interface, "oom" parameter is added. if oom==true,
820 * oom-killer can be invoked.
822 static int __mem_cgroup_try_charge(struct mm_struct *mm,
823 gfp_t gfp_mask, struct mem_cgroup **memcg,
826 struct mem_cgroup *mem, *mem_over_limit;
827 int nr_retries = MEM_CGROUP_RECLAIM_RETRIES;
828 struct res_counter *fail_res;
830 if (unlikely(test_thread_flag(TIF_MEMDIE))) {
831 /* Don't account this! */
837 * We always charge the cgroup the mm_struct belongs to.
838 * The mm_struct's mem_cgroup changes on task migration if the
839 * thread group leader migrates. It's possible that mm is not
840 * set, if so charge the init_mm (happens for pagecache usage).
844 mem = try_get_mem_cgroup_from_mm(mm);
852 VM_BUG_ON(mem_cgroup_is_obsolete(mem));
858 ret = res_counter_charge(&mem->res, PAGE_SIZE, &fail_res);
860 if (!do_swap_account)
862 ret = res_counter_charge(&mem->memsw, PAGE_SIZE,
866 /* mem+swap counter fails */
867 res_counter_uncharge(&mem->res, PAGE_SIZE);
869 mem_over_limit = mem_cgroup_from_res_counter(fail_res,
872 /* mem counter fails */
873 mem_over_limit = mem_cgroup_from_res_counter(fail_res,
876 if (!(gfp_mask & __GFP_WAIT))
879 ret = mem_cgroup_hierarchical_reclaim(mem_over_limit, gfp_mask,
883 * try_to_free_mem_cgroup_pages() might not give us a full
884 * picture of reclaim. Some pages are reclaimed and might be
885 * moved to swap cache or just unmapped from the cgroup.
886 * Check the limit again to see if the reclaim reduced the
887 * current usage of the cgroup before giving up
890 if (mem_cgroup_check_under_limit(mem_over_limit))
895 mutex_lock(&memcg_tasklist);
896 mem_cgroup_out_of_memory(mem_over_limit, gfp_mask);
897 mutex_unlock(&memcg_tasklist);
898 mem_over_limit->last_oom_jiffies = jiffies;
909 static struct mem_cgroup *try_get_mem_cgroup_from_swapcache(struct page *page)
911 struct mem_cgroup *mem;
914 if (!PageSwapCache(page))
917 ent.val = page_private(page);
918 mem = lookup_swap_cgroup(ent);
921 if (!css_tryget(&mem->css))
927 * commit a charge got by __mem_cgroup_try_charge() and makes page_cgroup to be
928 * USED state. If already USED, uncharge and return.
931 static void __mem_cgroup_commit_charge(struct mem_cgroup *mem,
932 struct page_cgroup *pc,
933 enum charge_type ctype)
935 /* try_charge() can return NULL to *memcg, taking care of it. */
939 lock_page_cgroup(pc);
940 if (unlikely(PageCgroupUsed(pc))) {
941 unlock_page_cgroup(pc);
942 res_counter_uncharge(&mem->res, PAGE_SIZE);
944 res_counter_uncharge(&mem->memsw, PAGE_SIZE);
948 pc->mem_cgroup = mem;
950 pc->flags = pcg_default_flags[ctype];
952 mem_cgroup_charge_statistics(mem, pc, true);
954 unlock_page_cgroup(pc);
958 * mem_cgroup_move_account - move account of the page
959 * @pc: page_cgroup of the page.
960 * @from: mem_cgroup which the page is moved from.
961 * @to: mem_cgroup which the page is moved to. @from != @to.
963 * The caller must confirm following.
964 * - page is not on LRU (isolate_page() is useful.)
966 * returns 0 at success,
967 * returns -EBUSY when lock is busy or "pc" is unstable.
969 * This function does "uncharge" from old cgroup but doesn't do "charge" to
970 * new cgroup. It should be done by a caller.
973 static int mem_cgroup_move_account(struct page_cgroup *pc,
974 struct mem_cgroup *from, struct mem_cgroup *to)
976 struct mem_cgroup_per_zone *from_mz, *to_mz;
980 VM_BUG_ON(from == to);
981 VM_BUG_ON(PageLRU(pc->page));
983 nid = page_cgroup_nid(pc);
984 zid = page_cgroup_zid(pc);
985 from_mz = mem_cgroup_zoneinfo(from, nid, zid);
986 to_mz = mem_cgroup_zoneinfo(to, nid, zid);
988 if (!trylock_page_cgroup(pc))
991 if (!PageCgroupUsed(pc))
994 if (pc->mem_cgroup != from)
998 res_counter_uncharge(&from->res, PAGE_SIZE);
999 mem_cgroup_charge_statistics(from, pc, false);
1000 if (do_swap_account)
1001 res_counter_uncharge(&from->memsw, PAGE_SIZE);
1002 pc->mem_cgroup = to;
1003 mem_cgroup_charge_statistics(to, pc, true);
1007 unlock_page_cgroup(pc);
1012 * move charges to its parent.
1015 static int mem_cgroup_move_parent(struct page_cgroup *pc,
1016 struct mem_cgroup *child,
1019 struct page *page = pc->page;
1020 struct cgroup *cg = child->css.cgroup;
1021 struct cgroup *pcg = cg->parent;
1022 struct mem_cgroup *parent;
1030 parent = mem_cgroup_from_cont(pcg);
1033 ret = __mem_cgroup_try_charge(NULL, gfp_mask, &parent, false);
1037 if (!get_page_unless_zero(page))
1040 ret = isolate_lru_page(page);
1045 ret = mem_cgroup_move_account(pc, child, parent);
1047 /* drop extra refcnt by try_charge() (move_account increment one) */
1048 css_put(&parent->css);
1049 putback_lru_page(page);
1054 /* uncharge if move fails */
1056 res_counter_uncharge(&parent->res, PAGE_SIZE);
1057 if (do_swap_account)
1058 res_counter_uncharge(&parent->memsw, PAGE_SIZE);
1064 * Charge the memory controller for page usage.
1066 * 0 if the charge was successful
1067 * < 0 if the cgroup is over its limit
1069 static int mem_cgroup_charge_common(struct page *page, struct mm_struct *mm,
1070 gfp_t gfp_mask, enum charge_type ctype,
1071 struct mem_cgroup *memcg)
1073 struct mem_cgroup *mem;
1074 struct page_cgroup *pc;
1077 pc = lookup_page_cgroup(page);
1078 /* can happen at boot */
1084 ret = __mem_cgroup_try_charge(mm, gfp_mask, &mem, true);
1088 __mem_cgroup_commit_charge(mem, pc, ctype);
1092 int mem_cgroup_newpage_charge(struct page *page,
1093 struct mm_struct *mm, gfp_t gfp_mask)
1095 if (mem_cgroup_disabled())
1097 if (PageCompound(page))
1100 * If already mapped, we don't have to account.
1101 * If page cache, page->mapping has address_space.
1102 * But page->mapping may have out-of-use anon_vma pointer,
1103 * detecit it by PageAnon() check. newly-mapped-anon's page->mapping
1106 if (page_mapped(page) || (page->mapping && !PageAnon(page)))
1110 return mem_cgroup_charge_common(page, mm, gfp_mask,
1111 MEM_CGROUP_CHARGE_TYPE_MAPPED, NULL);
1114 int mem_cgroup_cache_charge(struct page *page, struct mm_struct *mm,
1117 struct mem_cgroup *mem = NULL;
1120 if (mem_cgroup_disabled())
1122 if (PageCompound(page))
1125 * Corner case handling. This is called from add_to_page_cache()
1126 * in usual. But some FS (shmem) precharges this page before calling it
1127 * and call add_to_page_cache() with GFP_NOWAIT.
1129 * For GFP_NOWAIT case, the page may be pre-charged before calling
1130 * add_to_page_cache(). (See shmem.c) check it here and avoid to call
1131 * charge twice. (It works but has to pay a bit larger cost.)
1132 * And when the page is SwapCache, it should take swap information
1133 * into account. This is under lock_page() now.
1135 if (!(gfp_mask & __GFP_WAIT)) {
1136 struct page_cgroup *pc;
1139 pc = lookup_page_cgroup(page);
1142 lock_page_cgroup(pc);
1143 if (PageCgroupUsed(pc)) {
1144 unlock_page_cgroup(pc);
1147 unlock_page_cgroup(pc);
1150 if (do_swap_account && PageSwapCache(page)) {
1151 mem = try_get_mem_cgroup_from_swapcache(page);
1156 /* SwapCache may be still linked to LRU now. */
1157 mem_cgroup_lru_del_before_commit_swapcache(page);
1160 if (unlikely(!mm && !mem))
1163 if (page_is_file_cache(page))
1164 return mem_cgroup_charge_common(page, mm, gfp_mask,
1165 MEM_CGROUP_CHARGE_TYPE_CACHE, NULL);
1167 ret = mem_cgroup_charge_common(page, mm, gfp_mask,
1168 MEM_CGROUP_CHARGE_TYPE_SHMEM, mem);
1171 if (PageSwapCache(page))
1172 mem_cgroup_lru_add_after_commit_swapcache(page);
1174 if (do_swap_account && !ret && PageSwapCache(page)) {
1175 swp_entry_t ent = {.val = page_private(page)};
1176 /* avoid double counting */
1177 mem = swap_cgroup_record(ent, NULL);
1179 res_counter_uncharge(&mem->memsw, PAGE_SIZE);
1180 mem_cgroup_put(mem);
1187 * While swap-in, try_charge -> commit or cancel, the page is locked.
1188 * And when try_charge() successfully returns, one refcnt to memcg without
1189 * struct page_cgroup is aquired. This refcnt will be cumsumed by
1190 * "commit()" or removed by "cancel()"
1192 int mem_cgroup_try_charge_swapin(struct mm_struct *mm,
1194 gfp_t mask, struct mem_cgroup **ptr)
1196 struct mem_cgroup *mem;
1199 if (mem_cgroup_disabled())
1202 if (!do_swap_account)
1205 * A racing thread's fault, or swapoff, may have already updated
1206 * the pte, and even removed page from swap cache: return success
1207 * to go on to do_swap_page()'s pte_same() test, which should fail.
1209 if (!PageSwapCache(page))
1211 mem = try_get_mem_cgroup_from_swapcache(page);
1215 ret = __mem_cgroup_try_charge(NULL, mask, ptr, true);
1216 /* drop extra refcnt from tryget */
1222 return __mem_cgroup_try_charge(mm, mask, ptr, true);
1225 void mem_cgroup_commit_charge_swapin(struct page *page, struct mem_cgroup *ptr)
1227 struct page_cgroup *pc;
1229 if (mem_cgroup_disabled())
1233 pc = lookup_page_cgroup(page);
1234 mem_cgroup_lru_del_before_commit_swapcache(page);
1235 __mem_cgroup_commit_charge(ptr, pc, MEM_CGROUP_CHARGE_TYPE_MAPPED);
1236 mem_cgroup_lru_add_after_commit_swapcache(page);
1238 * Now swap is on-memory. This means this page may be
1239 * counted both as mem and swap....double count.
1240 * Fix it by uncharging from memsw. Basically, this SwapCache is stable
1241 * under lock_page(). But in do_swap_page()::memory.c, reuse_swap_page()
1242 * may call delete_from_swap_cache() before reach here.
1244 if (do_swap_account && PageSwapCache(page)) {
1245 swp_entry_t ent = {.val = page_private(page)};
1246 struct mem_cgroup *memcg;
1247 memcg = swap_cgroup_record(ent, NULL);
1249 res_counter_uncharge(&memcg->memsw, PAGE_SIZE);
1250 mem_cgroup_put(memcg);
1254 /* add this page(page_cgroup) to the LRU we want. */
1258 void mem_cgroup_cancel_charge_swapin(struct mem_cgroup *mem)
1260 if (mem_cgroup_disabled())
1264 res_counter_uncharge(&mem->res, PAGE_SIZE);
1265 if (do_swap_account)
1266 res_counter_uncharge(&mem->memsw, PAGE_SIZE);
1272 * uncharge if !page_mapped(page)
1274 static struct mem_cgroup *
1275 __mem_cgroup_uncharge_common(struct page *page, enum charge_type ctype)
1277 struct page_cgroup *pc;
1278 struct mem_cgroup *mem = NULL;
1279 struct mem_cgroup_per_zone *mz;
1281 if (mem_cgroup_disabled())
1284 if (PageSwapCache(page))
1288 * Check if our page_cgroup is valid
1290 pc = lookup_page_cgroup(page);
1291 if (unlikely(!pc || !PageCgroupUsed(pc)))
1294 lock_page_cgroup(pc);
1296 mem = pc->mem_cgroup;
1298 if (!PageCgroupUsed(pc))
1302 case MEM_CGROUP_CHARGE_TYPE_MAPPED:
1303 if (page_mapped(page))
1306 case MEM_CGROUP_CHARGE_TYPE_SWAPOUT:
1307 if (!PageAnon(page)) { /* Shared memory */
1308 if (page->mapping && !page_is_file_cache(page))
1310 } else if (page_mapped(page)) /* Anon */
1317 res_counter_uncharge(&mem->res, PAGE_SIZE);
1318 if (do_swap_account && (ctype != MEM_CGROUP_CHARGE_TYPE_SWAPOUT))
1319 res_counter_uncharge(&mem->memsw, PAGE_SIZE);
1321 mem_cgroup_charge_statistics(mem, pc, false);
1322 ClearPageCgroupUsed(pc);
1324 * pc->mem_cgroup is not cleared here. It will be accessed when it's
1325 * freed from LRU. This is safe because uncharged page is expected not
1326 * to be reused (freed soon). Exception is SwapCache, it's handled by
1327 * special functions.
1330 mz = page_cgroup_zoneinfo(pc);
1331 unlock_page_cgroup(pc);
1333 /* at swapout, this memcg will be accessed to record to swap */
1334 if (ctype != MEM_CGROUP_CHARGE_TYPE_SWAPOUT)
1340 unlock_page_cgroup(pc);
1344 void mem_cgroup_uncharge_page(struct page *page)
1347 if (page_mapped(page))
1349 if (page->mapping && !PageAnon(page))
1351 __mem_cgroup_uncharge_common(page, MEM_CGROUP_CHARGE_TYPE_MAPPED);
1354 void mem_cgroup_uncharge_cache_page(struct page *page)
1356 VM_BUG_ON(page_mapped(page));
1357 VM_BUG_ON(page->mapping);
1358 __mem_cgroup_uncharge_common(page, MEM_CGROUP_CHARGE_TYPE_CACHE);
1362 * called from __delete_from_swap_cache() and drop "page" account.
1363 * memcg information is recorded to swap_cgroup of "ent"
1365 void mem_cgroup_uncharge_swapcache(struct page *page, swp_entry_t ent)
1367 struct mem_cgroup *memcg;
1369 memcg = __mem_cgroup_uncharge_common(page,
1370 MEM_CGROUP_CHARGE_TYPE_SWAPOUT);
1371 /* record memcg information */
1372 if (do_swap_account && memcg) {
1373 swap_cgroup_record(ent, memcg);
1374 mem_cgroup_get(memcg);
1377 css_put(&memcg->css);
1380 #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP
1382 * called from swap_entry_free(). remove record in swap_cgroup and
1383 * uncharge "memsw" account.
1385 void mem_cgroup_uncharge_swap(swp_entry_t ent)
1387 struct mem_cgroup *memcg;
1389 if (!do_swap_account)
1392 memcg = swap_cgroup_record(ent, NULL);
1394 res_counter_uncharge(&memcg->memsw, PAGE_SIZE);
1395 mem_cgroup_put(memcg);
1401 * Before starting migration, account PAGE_SIZE to mem_cgroup that the old
1404 int mem_cgroup_prepare_migration(struct page *page, struct mem_cgroup **ptr)
1406 struct page_cgroup *pc;
1407 struct mem_cgroup *mem = NULL;
1410 if (mem_cgroup_disabled())
1413 pc = lookup_page_cgroup(page);
1414 lock_page_cgroup(pc);
1415 if (PageCgroupUsed(pc)) {
1416 mem = pc->mem_cgroup;
1419 unlock_page_cgroup(pc);
1422 ret = __mem_cgroup_try_charge(NULL, GFP_KERNEL, &mem, false);
1429 /* remove redundant charge if migration failed*/
1430 void mem_cgroup_end_migration(struct mem_cgroup *mem,
1431 struct page *oldpage, struct page *newpage)
1433 struct page *target, *unused;
1434 struct page_cgroup *pc;
1435 enum charge_type ctype;
1440 /* at migration success, oldpage->mapping is NULL. */
1441 if (oldpage->mapping) {
1449 if (PageAnon(target))
1450 ctype = MEM_CGROUP_CHARGE_TYPE_MAPPED;
1451 else if (page_is_file_cache(target))
1452 ctype = MEM_CGROUP_CHARGE_TYPE_CACHE;
1454 ctype = MEM_CGROUP_CHARGE_TYPE_SHMEM;
1456 /* unused page is not on radix-tree now. */
1458 __mem_cgroup_uncharge_common(unused, ctype);
1460 pc = lookup_page_cgroup(target);
1462 * __mem_cgroup_commit_charge() check PCG_USED bit of page_cgroup.
1463 * So, double-counting is effectively avoided.
1465 __mem_cgroup_commit_charge(mem, pc, ctype);
1468 * Both of oldpage and newpage are still under lock_page().
1469 * Then, we don't have to care about race in radix-tree.
1470 * But we have to be careful that this page is unmapped or not.
1472 * There is a case for !page_mapped(). At the start of
1473 * migration, oldpage was mapped. But now, it's zapped.
1474 * But we know *target* page is not freed/reused under us.
1475 * mem_cgroup_uncharge_page() does all necessary checks.
1477 if (ctype == MEM_CGROUP_CHARGE_TYPE_MAPPED)
1478 mem_cgroup_uncharge_page(target);
1482 * A call to try to shrink memory usage under specified resource controller.
1483 * This is typically used for page reclaiming for shmem for reducing side
1484 * effect of page allocation from shmem, which is used by some mem_cgroup.
1486 int mem_cgroup_shrink_usage(struct page *page,
1487 struct mm_struct *mm,
1490 struct mem_cgroup *mem = NULL;
1492 int retry = MEM_CGROUP_RECLAIM_RETRIES;
1494 if (mem_cgroup_disabled())
1497 mem = try_get_mem_cgroup_from_swapcache(page);
1499 mem = try_get_mem_cgroup_from_mm(mm);
1504 progress = mem_cgroup_hierarchical_reclaim(mem, gfp_mask, true);
1505 progress += mem_cgroup_check_under_limit(mem);
1506 } while (!progress && --retry);
1514 static DEFINE_MUTEX(set_limit_mutex);
1516 static int mem_cgroup_resize_limit(struct mem_cgroup *memcg,
1517 unsigned long long val)
1520 int retry_count = MEM_CGROUP_RECLAIM_RETRIES;
1525 while (retry_count) {
1526 if (signal_pending(current)) {
1531 * Rather than hide all in some function, I do this in
1532 * open coded manner. You see what this really does.
1533 * We have to guarantee mem->res.limit < mem->memsw.limit.
1535 mutex_lock(&set_limit_mutex);
1536 memswlimit = res_counter_read_u64(&memcg->memsw, RES_LIMIT);
1537 if (memswlimit < val) {
1539 mutex_unlock(&set_limit_mutex);
1542 ret = res_counter_set_limit(&memcg->res, val);
1543 mutex_unlock(&set_limit_mutex);
1548 progress = mem_cgroup_hierarchical_reclaim(memcg, GFP_KERNEL,
1550 if (!progress) retry_count--;
1556 int mem_cgroup_resize_memsw_limit(struct mem_cgroup *memcg,
1557 unsigned long long val)
1559 int retry_count = MEM_CGROUP_RECLAIM_RETRIES;
1560 u64 memlimit, oldusage, curusage;
1563 if (!do_swap_account)
1566 while (retry_count) {
1567 if (signal_pending(current)) {
1572 * Rather than hide all in some function, I do this in
1573 * open coded manner. You see what this really does.
1574 * We have to guarantee mem->res.limit < mem->memsw.limit.
1576 mutex_lock(&set_limit_mutex);
1577 memlimit = res_counter_read_u64(&memcg->res, RES_LIMIT);
1578 if (memlimit > val) {
1580 mutex_unlock(&set_limit_mutex);
1583 ret = res_counter_set_limit(&memcg->memsw, val);
1584 mutex_unlock(&set_limit_mutex);
1589 oldusage = res_counter_read_u64(&memcg->memsw, RES_USAGE);
1590 mem_cgroup_hierarchical_reclaim(memcg, GFP_KERNEL, true);
1591 curusage = res_counter_read_u64(&memcg->memsw, RES_USAGE);
1592 if (curusage >= oldusage)
1599 * This routine traverse page_cgroup in given list and drop them all.
1600 * *And* this routine doesn't reclaim page itself, just removes page_cgroup.
1602 static int mem_cgroup_force_empty_list(struct mem_cgroup *mem,
1603 int node, int zid, enum lru_list lru)
1606 struct mem_cgroup_per_zone *mz;
1607 struct page_cgroup *pc, *busy;
1608 unsigned long flags, loop;
1609 struct list_head *list;
1612 zone = &NODE_DATA(node)->node_zones[zid];
1613 mz = mem_cgroup_zoneinfo(mem, node, zid);
1614 list = &mz->lists[lru];
1616 loop = MEM_CGROUP_ZSTAT(mz, lru);
1617 /* give some margin against EBUSY etc...*/
1622 spin_lock_irqsave(&zone->lru_lock, flags);
1623 if (list_empty(list)) {
1624 spin_unlock_irqrestore(&zone->lru_lock, flags);
1627 pc = list_entry(list->prev, struct page_cgroup, lru);
1629 list_move(&pc->lru, list);
1631 spin_unlock_irqrestore(&zone->lru_lock, flags);
1634 spin_unlock_irqrestore(&zone->lru_lock, flags);
1636 ret = mem_cgroup_move_parent(pc, mem, GFP_KERNEL);
1640 if (ret == -EBUSY || ret == -EINVAL) {
1641 /* found lock contention or "pc" is obsolete. */
1648 if (!ret && !list_empty(list))
1654 * make mem_cgroup's charge to be 0 if there is no task.
1655 * This enables deleting this mem_cgroup.
1657 static int mem_cgroup_force_empty(struct mem_cgroup *mem, bool free_all)
1660 int node, zid, shrink;
1661 int nr_retries = MEM_CGROUP_RECLAIM_RETRIES;
1662 struct cgroup *cgrp = mem->css.cgroup;
1667 /* should free all ? */
1671 while (mem->res.usage > 0) {
1673 if (cgroup_task_count(cgrp) || !list_empty(&cgrp->children))
1676 if (signal_pending(current))
1678 /* This is for making all *used* pages to be on LRU. */
1679 lru_add_drain_all();
1681 for_each_node_state(node, N_POSSIBLE) {
1682 for (zid = 0; !ret && zid < MAX_NR_ZONES; zid++) {
1685 ret = mem_cgroup_force_empty_list(mem,
1694 /* it seems parent cgroup doesn't have enough mem */
1705 /* returns EBUSY if there is a task or if we come here twice. */
1706 if (cgroup_task_count(cgrp) || !list_empty(&cgrp->children) || shrink) {
1710 /* we call try-to-free pages for make this cgroup empty */
1711 lru_add_drain_all();
1712 /* try to free all pages in this cgroup */
1714 while (nr_retries && mem->res.usage > 0) {
1717 if (signal_pending(current)) {
1721 progress = try_to_free_mem_cgroup_pages(mem, GFP_KERNEL,
1722 false, get_swappiness(mem));
1725 /* maybe some writeback is necessary */
1726 congestion_wait(WRITE, HZ/10);
1731 /* try move_account...there may be some *locked* pages. */
1738 int mem_cgroup_force_empty_write(struct cgroup *cont, unsigned int event)
1740 return mem_cgroup_force_empty(mem_cgroup_from_cont(cont), true);
1744 static u64 mem_cgroup_hierarchy_read(struct cgroup *cont, struct cftype *cft)
1746 return mem_cgroup_from_cont(cont)->use_hierarchy;
1749 static int mem_cgroup_hierarchy_write(struct cgroup *cont, struct cftype *cft,
1753 struct mem_cgroup *mem = mem_cgroup_from_cont(cont);
1754 struct cgroup *parent = cont->parent;
1755 struct mem_cgroup *parent_mem = NULL;
1758 parent_mem = mem_cgroup_from_cont(parent);
1762 * If parent's use_hiearchy is set, we can't make any modifications
1763 * in the child subtrees. If it is unset, then the change can
1764 * occur, provided the current cgroup has no children.
1766 * For the root cgroup, parent_mem is NULL, we allow value to be
1767 * set if there are no children.
1769 if ((!parent_mem || !parent_mem->use_hierarchy) &&
1770 (val == 1 || val == 0)) {
1771 if (list_empty(&cont->children))
1772 mem->use_hierarchy = val;
1782 static u64 mem_cgroup_read(struct cgroup *cont, struct cftype *cft)
1784 struct mem_cgroup *mem = mem_cgroup_from_cont(cont);
1788 type = MEMFILE_TYPE(cft->private);
1789 name = MEMFILE_ATTR(cft->private);
1792 val = res_counter_read_u64(&mem->res, name);
1795 if (do_swap_account)
1796 val = res_counter_read_u64(&mem->memsw, name);
1805 * The user of this function is...
1808 static int mem_cgroup_write(struct cgroup *cont, struct cftype *cft,
1811 struct mem_cgroup *memcg = mem_cgroup_from_cont(cont);
1813 unsigned long long val;
1816 type = MEMFILE_TYPE(cft->private);
1817 name = MEMFILE_ATTR(cft->private);
1820 /* This function does all necessary parse...reuse it */
1821 ret = res_counter_memparse_write_strategy(buffer, &val);
1825 ret = mem_cgroup_resize_limit(memcg, val);
1827 ret = mem_cgroup_resize_memsw_limit(memcg, val);
1830 ret = -EINVAL; /* should be BUG() ? */
1836 static void memcg_get_hierarchical_limit(struct mem_cgroup *memcg,
1837 unsigned long long *mem_limit, unsigned long long *memsw_limit)
1839 struct cgroup *cgroup;
1840 unsigned long long min_limit, min_memsw_limit, tmp;
1842 min_limit = res_counter_read_u64(&memcg->res, RES_LIMIT);
1843 min_memsw_limit = res_counter_read_u64(&memcg->memsw, RES_LIMIT);
1844 cgroup = memcg->css.cgroup;
1845 if (!memcg->use_hierarchy)
1848 while (cgroup->parent) {
1849 cgroup = cgroup->parent;
1850 memcg = mem_cgroup_from_cont(cgroup);
1851 if (!memcg->use_hierarchy)
1853 tmp = res_counter_read_u64(&memcg->res, RES_LIMIT);
1854 min_limit = min(min_limit, tmp);
1855 tmp = res_counter_read_u64(&memcg->memsw, RES_LIMIT);
1856 min_memsw_limit = min(min_memsw_limit, tmp);
1859 *mem_limit = min_limit;
1860 *memsw_limit = min_memsw_limit;
1864 static int mem_cgroup_reset(struct cgroup *cont, unsigned int event)
1866 struct mem_cgroup *mem;
1869 mem = mem_cgroup_from_cont(cont);
1870 type = MEMFILE_TYPE(event);
1871 name = MEMFILE_ATTR(event);
1875 res_counter_reset_max(&mem->res);
1877 res_counter_reset_max(&mem->memsw);
1881 res_counter_reset_failcnt(&mem->res);
1883 res_counter_reset_failcnt(&mem->memsw);
1889 static const struct mem_cgroup_stat_desc {
1892 } mem_cgroup_stat_desc[] = {
1893 [MEM_CGROUP_STAT_CACHE] = { "cache", PAGE_SIZE, },
1894 [MEM_CGROUP_STAT_RSS] = { "rss", PAGE_SIZE, },
1895 [MEM_CGROUP_STAT_PGPGIN_COUNT] = {"pgpgin", 1, },
1896 [MEM_CGROUP_STAT_PGPGOUT_COUNT] = {"pgpgout", 1, },
1899 static int mem_control_stat_show(struct cgroup *cont, struct cftype *cft,
1900 struct cgroup_map_cb *cb)
1902 struct mem_cgroup *mem_cont = mem_cgroup_from_cont(cont);
1903 struct mem_cgroup_stat *stat = &mem_cont->stat;
1906 for (i = 0; i < ARRAY_SIZE(stat->cpustat[0].count); i++) {
1909 val = mem_cgroup_read_stat(stat, i);
1910 val *= mem_cgroup_stat_desc[i].unit;
1911 cb->fill(cb, mem_cgroup_stat_desc[i].msg, val);
1913 /* showing # of active pages */
1915 unsigned long active_anon, inactive_anon;
1916 unsigned long active_file, inactive_file;
1917 unsigned long unevictable;
1919 inactive_anon = mem_cgroup_get_all_zonestat(mem_cont,
1921 active_anon = mem_cgroup_get_all_zonestat(mem_cont,
1923 inactive_file = mem_cgroup_get_all_zonestat(mem_cont,
1925 active_file = mem_cgroup_get_all_zonestat(mem_cont,
1927 unevictable = mem_cgroup_get_all_zonestat(mem_cont,
1930 cb->fill(cb, "active_anon", (active_anon) * PAGE_SIZE);
1931 cb->fill(cb, "inactive_anon", (inactive_anon) * PAGE_SIZE);
1932 cb->fill(cb, "active_file", (active_file) * PAGE_SIZE);
1933 cb->fill(cb, "inactive_file", (inactive_file) * PAGE_SIZE);
1934 cb->fill(cb, "unevictable", unevictable * PAGE_SIZE);
1938 unsigned long long limit, memsw_limit;
1939 memcg_get_hierarchical_limit(mem_cont, &limit, &memsw_limit);
1940 cb->fill(cb, "hierarchical_memory_limit", limit);
1941 if (do_swap_account)
1942 cb->fill(cb, "hierarchical_memsw_limit", memsw_limit);
1945 #ifdef CONFIG_DEBUG_VM
1946 cb->fill(cb, "inactive_ratio", calc_inactive_ratio(mem_cont, NULL));
1950 struct mem_cgroup_per_zone *mz;
1951 unsigned long recent_rotated[2] = {0, 0};
1952 unsigned long recent_scanned[2] = {0, 0};
1954 for_each_online_node(nid)
1955 for (zid = 0; zid < MAX_NR_ZONES; zid++) {
1956 mz = mem_cgroup_zoneinfo(mem_cont, nid, zid);
1958 recent_rotated[0] +=
1959 mz->reclaim_stat.recent_rotated[0];
1960 recent_rotated[1] +=
1961 mz->reclaim_stat.recent_rotated[1];
1962 recent_scanned[0] +=
1963 mz->reclaim_stat.recent_scanned[0];
1964 recent_scanned[1] +=
1965 mz->reclaim_stat.recent_scanned[1];
1967 cb->fill(cb, "recent_rotated_anon", recent_rotated[0]);
1968 cb->fill(cb, "recent_rotated_file", recent_rotated[1]);
1969 cb->fill(cb, "recent_scanned_anon", recent_scanned[0]);
1970 cb->fill(cb, "recent_scanned_file", recent_scanned[1]);
1977 static u64 mem_cgroup_swappiness_read(struct cgroup *cgrp, struct cftype *cft)
1979 struct mem_cgroup *memcg = mem_cgroup_from_cont(cgrp);
1981 return get_swappiness(memcg);
1984 static int mem_cgroup_swappiness_write(struct cgroup *cgrp, struct cftype *cft,
1987 struct mem_cgroup *memcg = mem_cgroup_from_cont(cgrp);
1988 struct mem_cgroup *parent;
1992 if (cgrp->parent == NULL)
1995 parent = mem_cgroup_from_cont(cgrp->parent);
1996 /* If under hierarchy, only empty-root can set this value */
1997 if ((parent->use_hierarchy) ||
1998 (memcg->use_hierarchy && !list_empty(&cgrp->children)))
2001 spin_lock(&memcg->reclaim_param_lock);
2002 memcg->swappiness = val;
2003 spin_unlock(&memcg->reclaim_param_lock);
2009 static struct cftype mem_cgroup_files[] = {
2011 .name = "usage_in_bytes",
2012 .private = MEMFILE_PRIVATE(_MEM, RES_USAGE),
2013 .read_u64 = mem_cgroup_read,
2016 .name = "max_usage_in_bytes",
2017 .private = MEMFILE_PRIVATE(_MEM, RES_MAX_USAGE),
2018 .trigger = mem_cgroup_reset,
2019 .read_u64 = mem_cgroup_read,
2022 .name = "limit_in_bytes",
2023 .private = MEMFILE_PRIVATE(_MEM, RES_LIMIT),
2024 .write_string = mem_cgroup_write,
2025 .read_u64 = mem_cgroup_read,
2029 .private = MEMFILE_PRIVATE(_MEM, RES_FAILCNT),
2030 .trigger = mem_cgroup_reset,
2031 .read_u64 = mem_cgroup_read,
2035 .read_map = mem_control_stat_show,
2038 .name = "force_empty",
2039 .trigger = mem_cgroup_force_empty_write,
2042 .name = "use_hierarchy",
2043 .write_u64 = mem_cgroup_hierarchy_write,
2044 .read_u64 = mem_cgroup_hierarchy_read,
2047 .name = "swappiness",
2048 .read_u64 = mem_cgroup_swappiness_read,
2049 .write_u64 = mem_cgroup_swappiness_write,
2053 #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP
2054 static struct cftype memsw_cgroup_files[] = {
2056 .name = "memsw.usage_in_bytes",
2057 .private = MEMFILE_PRIVATE(_MEMSWAP, RES_USAGE),
2058 .read_u64 = mem_cgroup_read,
2061 .name = "memsw.max_usage_in_bytes",
2062 .private = MEMFILE_PRIVATE(_MEMSWAP, RES_MAX_USAGE),
2063 .trigger = mem_cgroup_reset,
2064 .read_u64 = mem_cgroup_read,
2067 .name = "memsw.limit_in_bytes",
2068 .private = MEMFILE_PRIVATE(_MEMSWAP, RES_LIMIT),
2069 .write_string = mem_cgroup_write,
2070 .read_u64 = mem_cgroup_read,
2073 .name = "memsw.failcnt",
2074 .private = MEMFILE_PRIVATE(_MEMSWAP, RES_FAILCNT),
2075 .trigger = mem_cgroup_reset,
2076 .read_u64 = mem_cgroup_read,
2080 static int register_memsw_files(struct cgroup *cont, struct cgroup_subsys *ss)
2082 if (!do_swap_account)
2084 return cgroup_add_files(cont, ss, memsw_cgroup_files,
2085 ARRAY_SIZE(memsw_cgroup_files));
2088 static int register_memsw_files(struct cgroup *cont, struct cgroup_subsys *ss)
2094 static int alloc_mem_cgroup_per_zone_info(struct mem_cgroup *mem, int node)
2096 struct mem_cgroup_per_node *pn;
2097 struct mem_cgroup_per_zone *mz;
2099 int zone, tmp = node;
2101 * This routine is called against possible nodes.
2102 * But it's BUG to call kmalloc() against offline node.
2104 * TODO: this routine can waste much memory for nodes which will
2105 * never be onlined. It's better to use memory hotplug callback
2108 if (!node_state(node, N_NORMAL_MEMORY))
2110 pn = kmalloc_node(sizeof(*pn), GFP_KERNEL, tmp);
2114 mem->info.nodeinfo[node] = pn;
2115 memset(pn, 0, sizeof(*pn));
2117 for (zone = 0; zone < MAX_NR_ZONES; zone++) {
2118 mz = &pn->zoneinfo[zone];
2120 INIT_LIST_HEAD(&mz->lists[l]);
2125 static void free_mem_cgroup_per_zone_info(struct mem_cgroup *mem, int node)
2127 kfree(mem->info.nodeinfo[node]);
2130 static int mem_cgroup_size(void)
2132 int cpustat_size = nr_cpu_ids * sizeof(struct mem_cgroup_stat_cpu);
2133 return sizeof(struct mem_cgroup) + cpustat_size;
2136 static struct mem_cgroup *mem_cgroup_alloc(void)
2138 struct mem_cgroup *mem;
2139 int size = mem_cgroup_size();
2141 if (size < PAGE_SIZE)
2142 mem = kmalloc(size, GFP_KERNEL);
2144 mem = vmalloc(size);
2147 memset(mem, 0, size);
2152 * At destroying mem_cgroup, references from swap_cgroup can remain.
2153 * (scanning all at force_empty is too costly...)
2155 * Instead of clearing all references at force_empty, we remember
2156 * the number of reference from swap_cgroup and free mem_cgroup when
2157 * it goes down to 0.
2159 * Removal of cgroup itself succeeds regardless of refs from swap.
2162 static void __mem_cgroup_free(struct mem_cgroup *mem)
2166 for_each_node_state(node, N_POSSIBLE)
2167 free_mem_cgroup_per_zone_info(mem, node);
2169 if (mem_cgroup_size() < PAGE_SIZE)
2175 static void mem_cgroup_get(struct mem_cgroup *mem)
2177 atomic_inc(&mem->refcnt);
2180 static void mem_cgroup_put(struct mem_cgroup *mem)
2182 if (atomic_dec_and_test(&mem->refcnt))
2183 __mem_cgroup_free(mem);
2187 #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP
2188 static void __init enable_swap_cgroup(void)
2190 if (!mem_cgroup_disabled() && really_do_swap_account)
2191 do_swap_account = 1;
2194 static void __init enable_swap_cgroup(void)
2199 static struct cgroup_subsys_state *
2200 mem_cgroup_create(struct cgroup_subsys *ss, struct cgroup *cont)
2202 struct mem_cgroup *mem, *parent;
2205 mem = mem_cgroup_alloc();
2207 return ERR_PTR(-ENOMEM);
2209 for_each_node_state(node, N_POSSIBLE)
2210 if (alloc_mem_cgroup_per_zone_info(mem, node))
2213 if (cont->parent == NULL) {
2214 enable_swap_cgroup();
2217 parent = mem_cgroup_from_cont(cont->parent);
2218 mem->use_hierarchy = parent->use_hierarchy;
2221 if (parent && parent->use_hierarchy) {
2222 res_counter_init(&mem->res, &parent->res);
2223 res_counter_init(&mem->memsw, &parent->memsw);
2225 res_counter_init(&mem->res, NULL);
2226 res_counter_init(&mem->memsw, NULL);
2228 mem->last_scanned_child = NULL;
2229 spin_lock_init(&mem->reclaim_param_lock);
2232 mem->swappiness = get_swappiness(parent);
2233 atomic_set(&mem->refcnt, 1);
2236 __mem_cgroup_free(mem);
2237 return ERR_PTR(-ENOMEM);
2240 static void mem_cgroup_pre_destroy(struct cgroup_subsys *ss,
2241 struct cgroup *cont)
2243 struct mem_cgroup *mem = mem_cgroup_from_cont(cont);
2244 mem_cgroup_force_empty(mem, false);
2247 static void mem_cgroup_destroy(struct cgroup_subsys *ss,
2248 struct cgroup *cont)
2250 mem_cgroup_put(mem_cgroup_from_cont(cont));
2253 static int mem_cgroup_populate(struct cgroup_subsys *ss,
2254 struct cgroup *cont)
2258 ret = cgroup_add_files(cont, ss, mem_cgroup_files,
2259 ARRAY_SIZE(mem_cgroup_files));
2262 ret = register_memsw_files(cont, ss);
2266 static void mem_cgroup_move_task(struct cgroup_subsys *ss,
2267 struct cgroup *cont,
2268 struct cgroup *old_cont,
2269 struct task_struct *p)
2271 mutex_lock(&memcg_tasklist);
2273 * FIXME: It's better to move charges of this process from old
2274 * memcg to new memcg. But it's just on TODO-List now.
2276 mutex_unlock(&memcg_tasklist);
2279 struct cgroup_subsys mem_cgroup_subsys = {
2281 .subsys_id = mem_cgroup_subsys_id,
2282 .create = mem_cgroup_create,
2283 .pre_destroy = mem_cgroup_pre_destroy,
2284 .destroy = mem_cgroup_destroy,
2285 .populate = mem_cgroup_populate,
2286 .attach = mem_cgroup_move_task,
2290 #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP
2292 static int __init disable_swap_account(char *s)
2294 really_do_swap_account = 0;
2297 __setup("noswapaccount", disable_swap_account);