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 cgroup_lock()
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 /* unused page is not rotated. */
363 if (!PageCgroupUsed(pc))
365 mz = page_cgroup_zoneinfo(pc);
366 list_move(&pc->lru, &mz->lists[lru]);
369 void mem_cgroup_add_lru_list(struct page *page, enum lru_list lru)
371 struct page_cgroup *pc;
372 struct mem_cgroup_per_zone *mz;
374 if (mem_cgroup_disabled())
376 pc = lookup_page_cgroup(page);
377 /* barrier to sync with "charge" */
379 if (!PageCgroupUsed(pc))
382 mz = page_cgroup_zoneinfo(pc);
383 MEM_CGROUP_ZSTAT(mz, lru) += 1;
384 list_add(&pc->lru, &mz->lists[lru]);
388 * At handling SwapCache, pc->mem_cgroup may be changed while it's linked to
389 * lru because the page may.be reused after it's fully uncharged (because of
390 * SwapCache behavior).To handle that, unlink page_cgroup from LRU when charge
391 * it again. This function is only used to charge SwapCache. It's done under
392 * lock_page and expected that zone->lru_lock is never held.
394 static void mem_cgroup_lru_del_before_commit_swapcache(struct page *page)
397 struct zone *zone = page_zone(page);
398 struct page_cgroup *pc = lookup_page_cgroup(page);
400 spin_lock_irqsave(&zone->lru_lock, flags);
402 * Forget old LRU when this page_cgroup is *not* used. This Used bit
403 * is guarded by lock_page() because the page is SwapCache.
405 if (!PageCgroupUsed(pc))
406 mem_cgroup_del_lru_list(page, page_lru(page));
407 spin_unlock_irqrestore(&zone->lru_lock, flags);
410 static void mem_cgroup_lru_add_after_commit_swapcache(struct page *page)
413 struct zone *zone = page_zone(page);
414 struct page_cgroup *pc = lookup_page_cgroup(page);
416 spin_lock_irqsave(&zone->lru_lock, flags);
417 /* link when the page is linked to LRU but page_cgroup isn't */
418 if (PageLRU(page) && list_empty(&pc->lru))
419 mem_cgroup_add_lru_list(page, page_lru(page));
420 spin_unlock_irqrestore(&zone->lru_lock, flags);
424 void mem_cgroup_move_lists(struct page *page,
425 enum lru_list from, enum lru_list to)
427 if (mem_cgroup_disabled())
429 mem_cgroup_del_lru_list(page, from);
430 mem_cgroup_add_lru_list(page, to);
433 int task_in_mem_cgroup(struct task_struct *task, const struct mem_cgroup *mem)
438 ret = task->mm && mm_match_cgroup(task->mm, mem);
444 * Calculate mapped_ratio under memory controller. This will be used in
445 * vmscan.c for deteremining we have to reclaim mapped pages.
447 int mem_cgroup_calc_mapped_ratio(struct mem_cgroup *mem)
452 * usage is recorded in bytes. But, here, we assume the number of
453 * physical pages can be represented by "long" on any arch.
455 total = (long) (mem->res.usage >> PAGE_SHIFT) + 1L;
456 rss = (long)mem_cgroup_read_stat(&mem->stat, MEM_CGROUP_STAT_RSS);
457 return (int)((rss * 100L) / total);
461 * prev_priority control...this will be used in memory reclaim path.
463 int mem_cgroup_get_reclaim_priority(struct mem_cgroup *mem)
467 spin_lock(&mem->reclaim_param_lock);
468 prev_priority = mem->prev_priority;
469 spin_unlock(&mem->reclaim_param_lock);
471 return prev_priority;
474 void mem_cgroup_note_reclaim_priority(struct mem_cgroup *mem, int priority)
476 spin_lock(&mem->reclaim_param_lock);
477 if (priority < mem->prev_priority)
478 mem->prev_priority = priority;
479 spin_unlock(&mem->reclaim_param_lock);
482 void mem_cgroup_record_reclaim_priority(struct mem_cgroup *mem, int priority)
484 spin_lock(&mem->reclaim_param_lock);
485 mem->prev_priority = priority;
486 spin_unlock(&mem->reclaim_param_lock);
489 static int calc_inactive_ratio(struct mem_cgroup *memcg, unsigned long *present_pages)
491 unsigned long active;
492 unsigned long inactive;
494 unsigned long inactive_ratio;
496 inactive = mem_cgroup_get_all_zonestat(memcg, LRU_INACTIVE_ANON);
497 active = mem_cgroup_get_all_zonestat(memcg, LRU_ACTIVE_ANON);
499 gb = (inactive + active) >> (30 - PAGE_SHIFT);
501 inactive_ratio = int_sqrt(10 * gb);
506 present_pages[0] = inactive;
507 present_pages[1] = active;
510 return inactive_ratio;
513 int mem_cgroup_inactive_anon_is_low(struct mem_cgroup *memcg)
515 unsigned long active;
516 unsigned long inactive;
517 unsigned long present_pages[2];
518 unsigned long inactive_ratio;
520 inactive_ratio = calc_inactive_ratio(memcg, present_pages);
522 inactive = present_pages[0];
523 active = present_pages[1];
525 if (inactive * inactive_ratio < active)
531 unsigned long mem_cgroup_zone_nr_pages(struct mem_cgroup *memcg,
535 int nid = zone->zone_pgdat->node_id;
536 int zid = zone_idx(zone);
537 struct mem_cgroup_per_zone *mz = mem_cgroup_zoneinfo(memcg, nid, zid);
539 return MEM_CGROUP_ZSTAT(mz, lru);
542 struct zone_reclaim_stat *mem_cgroup_get_reclaim_stat(struct mem_cgroup *memcg,
545 int nid = zone->zone_pgdat->node_id;
546 int zid = zone_idx(zone);
547 struct mem_cgroup_per_zone *mz = mem_cgroup_zoneinfo(memcg, nid, zid);
549 return &mz->reclaim_stat;
552 struct zone_reclaim_stat *
553 mem_cgroup_get_reclaim_stat_from_page(struct page *page)
555 struct page_cgroup *pc;
556 struct mem_cgroup_per_zone *mz;
558 if (mem_cgroup_disabled())
561 pc = lookup_page_cgroup(page);
562 mz = page_cgroup_zoneinfo(pc);
566 return &mz->reclaim_stat;
569 unsigned long mem_cgroup_isolate_pages(unsigned long nr_to_scan,
570 struct list_head *dst,
571 unsigned long *scanned, int order,
572 int mode, struct zone *z,
573 struct mem_cgroup *mem_cont,
574 int active, int file)
576 unsigned long nr_taken = 0;
580 struct list_head *src;
581 struct page_cgroup *pc, *tmp;
582 int nid = z->zone_pgdat->node_id;
583 int zid = zone_idx(z);
584 struct mem_cgroup_per_zone *mz;
585 int lru = LRU_FILE * !!file + !!active;
588 mz = mem_cgroup_zoneinfo(mem_cont, nid, zid);
589 src = &mz->lists[lru];
592 list_for_each_entry_safe_reverse(pc, tmp, src, lru) {
593 if (scan >= nr_to_scan)
597 if (unlikely(!PageCgroupUsed(pc)))
599 if (unlikely(!PageLRU(page)))
603 if (__isolate_lru_page(page, mode, file) == 0) {
604 list_move(&page->lru, dst);
613 #define mem_cgroup_from_res_counter(counter, member) \
614 container_of(counter, struct mem_cgroup, member)
617 * This routine finds the DFS walk successor. This routine should be
618 * called with cgroup_mutex held
620 static struct mem_cgroup *
621 mem_cgroup_get_next_node(struct mem_cgroup *curr, struct mem_cgroup *root_mem)
623 struct cgroup *cgroup, *curr_cgroup, *root_cgroup;
625 curr_cgroup = curr->css.cgroup;
626 root_cgroup = root_mem->css.cgroup;
628 if (!list_empty(&curr_cgroup->children)) {
630 * Walk down to children
632 mem_cgroup_put(curr);
633 cgroup = list_entry(curr_cgroup->children.next,
634 struct cgroup, sibling);
635 curr = mem_cgroup_from_cont(cgroup);
636 mem_cgroup_get(curr);
641 if (curr_cgroup == root_cgroup) {
642 mem_cgroup_put(curr);
644 mem_cgroup_get(curr);
651 if (curr_cgroup->sibling.next != &curr_cgroup->parent->children) {
652 mem_cgroup_put(curr);
653 cgroup = list_entry(curr_cgroup->sibling.next, struct cgroup,
655 curr = mem_cgroup_from_cont(cgroup);
656 mem_cgroup_get(curr);
661 * Go up to next parent and next parent's sibling if need be
663 curr_cgroup = curr_cgroup->parent;
667 root_mem->last_scanned_child = curr;
672 * Visit the first child (need not be the first child as per the ordering
673 * of the cgroup list, since we track last_scanned_child) of @mem and use
674 * that to reclaim free pages from.
676 static struct mem_cgroup *
677 mem_cgroup_get_first_node(struct mem_cgroup *root_mem)
679 struct cgroup *cgroup;
680 struct mem_cgroup *ret;
683 obsolete = mem_cgroup_is_obsolete(root_mem->last_scanned_child);
686 * Scan all children under the mem_cgroup mem
689 if (list_empty(&root_mem->css.cgroup->children)) {
694 if (!root_mem->last_scanned_child || obsolete) {
696 if (obsolete && root_mem->last_scanned_child)
697 mem_cgroup_put(root_mem->last_scanned_child);
699 cgroup = list_first_entry(&root_mem->css.cgroup->children,
700 struct cgroup, sibling);
701 ret = mem_cgroup_from_cont(cgroup);
704 ret = mem_cgroup_get_next_node(root_mem->last_scanned_child,
708 root_mem->last_scanned_child = ret;
713 static bool mem_cgroup_check_under_limit(struct mem_cgroup *mem)
715 if (do_swap_account) {
716 if (res_counter_check_under_limit(&mem->res) &&
717 res_counter_check_under_limit(&mem->memsw))
720 if (res_counter_check_under_limit(&mem->res))
725 static unsigned int get_swappiness(struct mem_cgroup *memcg)
727 struct cgroup *cgrp = memcg->css.cgroup;
728 unsigned int swappiness;
731 if (cgrp->parent == NULL)
732 return vm_swappiness;
734 spin_lock(&memcg->reclaim_param_lock);
735 swappiness = memcg->swappiness;
736 spin_unlock(&memcg->reclaim_param_lock);
742 * Dance down the hierarchy if needed to reclaim memory. We remember the
743 * last child we reclaimed from, so that we don't end up penalizing
744 * one child extensively based on its position in the children list.
746 * root_mem is the original ancestor that we've been reclaim from.
748 static int mem_cgroup_hierarchical_reclaim(struct mem_cgroup *root_mem,
749 gfp_t gfp_mask, bool noswap)
751 struct mem_cgroup *next_mem;
755 * Reclaim unconditionally and don't check for return value.
756 * We need to reclaim in the current group and down the tree.
757 * One might think about checking for children before reclaiming,
758 * but there might be left over accounting, even after children
761 ret = try_to_free_mem_cgroup_pages(root_mem, gfp_mask, noswap,
762 get_swappiness(root_mem));
763 if (mem_cgroup_check_under_limit(root_mem))
765 if (!root_mem->use_hierarchy)
768 next_mem = mem_cgroup_get_first_node(root_mem);
770 while (next_mem != root_mem) {
771 if (mem_cgroup_is_obsolete(next_mem)) {
772 mem_cgroup_put(next_mem);
774 next_mem = mem_cgroup_get_first_node(root_mem);
778 ret = try_to_free_mem_cgroup_pages(next_mem, gfp_mask, noswap,
779 get_swappiness(next_mem));
780 if (mem_cgroup_check_under_limit(root_mem))
783 next_mem = mem_cgroup_get_next_node(next_mem, root_mem);
789 bool mem_cgroup_oom_called(struct task_struct *task)
792 struct mem_cgroup *mem;
793 struct mm_struct *mm;
799 mem = mem_cgroup_from_task(rcu_dereference(mm->owner));
800 if (mem && time_before(jiffies, mem->last_oom_jiffies + HZ/10))
806 * Unlike exported interface, "oom" parameter is added. if oom==true,
807 * oom-killer can be invoked.
809 static int __mem_cgroup_try_charge(struct mm_struct *mm,
810 gfp_t gfp_mask, struct mem_cgroup **memcg,
813 struct mem_cgroup *mem, *mem_over_limit;
814 int nr_retries = MEM_CGROUP_RECLAIM_RETRIES;
815 struct res_counter *fail_res;
817 if (unlikely(test_thread_flag(TIF_MEMDIE))) {
818 /* Don't account this! */
824 * We always charge the cgroup the mm_struct belongs to.
825 * The mm_struct's mem_cgroup changes on task migration if the
826 * thread group leader migrates. It's possible that mm is not
827 * set, if so charge the init_mm (happens for pagecache usage).
831 mem = try_get_mem_cgroup_from_mm(mm);
839 VM_BUG_ON(mem_cgroup_is_obsolete(mem));
845 ret = res_counter_charge(&mem->res, PAGE_SIZE, &fail_res);
847 if (!do_swap_account)
849 ret = res_counter_charge(&mem->memsw, PAGE_SIZE,
853 /* mem+swap counter fails */
854 res_counter_uncharge(&mem->res, PAGE_SIZE);
856 mem_over_limit = mem_cgroup_from_res_counter(fail_res,
859 /* mem counter fails */
860 mem_over_limit = mem_cgroup_from_res_counter(fail_res,
863 if (!(gfp_mask & __GFP_WAIT))
866 ret = mem_cgroup_hierarchical_reclaim(mem_over_limit, gfp_mask,
870 * try_to_free_mem_cgroup_pages() might not give us a full
871 * picture of reclaim. Some pages are reclaimed and might be
872 * moved to swap cache or just unmapped from the cgroup.
873 * Check the limit again to see if the reclaim reduced the
874 * current usage of the cgroup before giving up
877 if (mem_cgroup_check_under_limit(mem_over_limit))
882 mutex_lock(&memcg_tasklist);
883 mem_cgroup_out_of_memory(mem_over_limit, gfp_mask);
884 mutex_unlock(&memcg_tasklist);
885 mem_over_limit->last_oom_jiffies = jiffies;
896 static struct mem_cgroup *try_get_mem_cgroup_from_swapcache(struct page *page)
898 struct mem_cgroup *mem;
901 if (!PageSwapCache(page))
904 ent.val = page_private(page);
905 mem = lookup_swap_cgroup(ent);
908 if (!css_tryget(&mem->css))
914 * commit a charge got by __mem_cgroup_try_charge() and makes page_cgroup to be
915 * USED state. If already USED, uncharge and return.
918 static void __mem_cgroup_commit_charge(struct mem_cgroup *mem,
919 struct page_cgroup *pc,
920 enum charge_type ctype)
922 /* try_charge() can return NULL to *memcg, taking care of it. */
926 lock_page_cgroup(pc);
927 if (unlikely(PageCgroupUsed(pc))) {
928 unlock_page_cgroup(pc);
929 res_counter_uncharge(&mem->res, PAGE_SIZE);
931 res_counter_uncharge(&mem->memsw, PAGE_SIZE);
935 pc->mem_cgroup = mem;
937 pc->flags = pcg_default_flags[ctype];
939 mem_cgroup_charge_statistics(mem, pc, true);
941 unlock_page_cgroup(pc);
945 * mem_cgroup_move_account - move account of the page
946 * @pc: page_cgroup of the page.
947 * @from: mem_cgroup which the page is moved from.
948 * @to: mem_cgroup which the page is moved to. @from != @to.
950 * The caller must confirm following.
951 * - page is not on LRU (isolate_page() is useful.)
953 * returns 0 at success,
954 * returns -EBUSY when lock is busy or "pc" is unstable.
956 * This function does "uncharge" from old cgroup but doesn't do "charge" to
957 * new cgroup. It should be done by a caller.
960 static int mem_cgroup_move_account(struct page_cgroup *pc,
961 struct mem_cgroup *from, struct mem_cgroup *to)
963 struct mem_cgroup_per_zone *from_mz, *to_mz;
967 VM_BUG_ON(from == to);
968 VM_BUG_ON(PageLRU(pc->page));
970 nid = page_cgroup_nid(pc);
971 zid = page_cgroup_zid(pc);
972 from_mz = mem_cgroup_zoneinfo(from, nid, zid);
973 to_mz = mem_cgroup_zoneinfo(to, nid, zid);
975 if (!trylock_page_cgroup(pc))
978 if (!PageCgroupUsed(pc))
981 if (pc->mem_cgroup != from)
985 res_counter_uncharge(&from->res, PAGE_SIZE);
986 mem_cgroup_charge_statistics(from, pc, false);
988 res_counter_uncharge(&from->memsw, PAGE_SIZE);
990 mem_cgroup_charge_statistics(to, pc, true);
994 unlock_page_cgroup(pc);
999 * move charges to its parent.
1002 static int mem_cgroup_move_parent(struct page_cgroup *pc,
1003 struct mem_cgroup *child,
1006 struct page *page = pc->page;
1007 struct cgroup *cg = child->css.cgroup;
1008 struct cgroup *pcg = cg->parent;
1009 struct mem_cgroup *parent;
1017 parent = mem_cgroup_from_cont(pcg);
1020 ret = __mem_cgroup_try_charge(NULL, gfp_mask, &parent, false);
1024 if (!get_page_unless_zero(page))
1027 ret = isolate_lru_page(page);
1032 ret = mem_cgroup_move_account(pc, child, parent);
1034 /* drop extra refcnt by try_charge() (move_account increment one) */
1035 css_put(&parent->css);
1036 putback_lru_page(page);
1041 /* uncharge if move fails */
1043 res_counter_uncharge(&parent->res, PAGE_SIZE);
1044 if (do_swap_account)
1045 res_counter_uncharge(&parent->memsw, PAGE_SIZE);
1051 * Charge the memory controller for page usage.
1053 * 0 if the charge was successful
1054 * < 0 if the cgroup is over its limit
1056 static int mem_cgroup_charge_common(struct page *page, struct mm_struct *mm,
1057 gfp_t gfp_mask, enum charge_type ctype,
1058 struct mem_cgroup *memcg)
1060 struct mem_cgroup *mem;
1061 struct page_cgroup *pc;
1064 pc = lookup_page_cgroup(page);
1065 /* can happen at boot */
1071 ret = __mem_cgroup_try_charge(mm, gfp_mask, &mem, true);
1075 __mem_cgroup_commit_charge(mem, pc, ctype);
1079 int mem_cgroup_newpage_charge(struct page *page,
1080 struct mm_struct *mm, gfp_t gfp_mask)
1082 if (mem_cgroup_disabled())
1084 if (PageCompound(page))
1087 * If already mapped, we don't have to account.
1088 * If page cache, page->mapping has address_space.
1089 * But page->mapping may have out-of-use anon_vma pointer,
1090 * detecit it by PageAnon() check. newly-mapped-anon's page->mapping
1093 if (page_mapped(page) || (page->mapping && !PageAnon(page)))
1097 return mem_cgroup_charge_common(page, mm, gfp_mask,
1098 MEM_CGROUP_CHARGE_TYPE_MAPPED, NULL);
1101 int mem_cgroup_cache_charge(struct page *page, struct mm_struct *mm,
1104 struct mem_cgroup *mem = NULL;
1107 if (mem_cgroup_disabled())
1109 if (PageCompound(page))
1112 * Corner case handling. This is called from add_to_page_cache()
1113 * in usual. But some FS (shmem) precharges this page before calling it
1114 * and call add_to_page_cache() with GFP_NOWAIT.
1116 * For GFP_NOWAIT case, the page may be pre-charged before calling
1117 * add_to_page_cache(). (See shmem.c) check it here and avoid to call
1118 * charge twice. (It works but has to pay a bit larger cost.)
1119 * And when the page is SwapCache, it should take swap information
1120 * into account. This is under lock_page() now.
1122 if (!(gfp_mask & __GFP_WAIT)) {
1123 struct page_cgroup *pc;
1126 pc = lookup_page_cgroup(page);
1129 lock_page_cgroup(pc);
1130 if (PageCgroupUsed(pc)) {
1131 unlock_page_cgroup(pc);
1134 unlock_page_cgroup(pc);
1137 if (do_swap_account && PageSwapCache(page)) {
1138 mem = try_get_mem_cgroup_from_swapcache(page);
1143 /* SwapCache may be still linked to LRU now. */
1144 mem_cgroup_lru_del_before_commit_swapcache(page);
1147 if (unlikely(!mm && !mem))
1150 if (page_is_file_cache(page))
1151 return mem_cgroup_charge_common(page, mm, gfp_mask,
1152 MEM_CGROUP_CHARGE_TYPE_CACHE, NULL);
1154 ret = mem_cgroup_charge_common(page, mm, gfp_mask,
1155 MEM_CGROUP_CHARGE_TYPE_SHMEM, mem);
1158 if (PageSwapCache(page))
1159 mem_cgroup_lru_add_after_commit_swapcache(page);
1161 if (do_swap_account && !ret && PageSwapCache(page)) {
1162 swp_entry_t ent = {.val = page_private(page)};
1163 /* avoid double counting */
1164 mem = swap_cgroup_record(ent, NULL);
1166 res_counter_uncharge(&mem->memsw, PAGE_SIZE);
1167 mem_cgroup_put(mem);
1174 * While swap-in, try_charge -> commit or cancel, the page is locked.
1175 * And when try_charge() successfully returns, one refcnt to memcg without
1176 * struct page_cgroup is aquired. This refcnt will be cumsumed by
1177 * "commit()" or removed by "cancel()"
1179 int mem_cgroup_try_charge_swapin(struct mm_struct *mm,
1181 gfp_t mask, struct mem_cgroup **ptr)
1183 struct mem_cgroup *mem;
1186 if (mem_cgroup_disabled())
1189 if (!do_swap_account)
1192 * A racing thread's fault, or swapoff, may have already updated
1193 * the pte, and even removed page from swap cache: return success
1194 * to go on to do_swap_page()'s pte_same() test, which should fail.
1196 if (!PageSwapCache(page))
1198 mem = try_get_mem_cgroup_from_swapcache(page);
1202 ret = __mem_cgroup_try_charge(NULL, mask, ptr, true);
1203 /* drop extra refcnt from tryget */
1209 return __mem_cgroup_try_charge(mm, mask, ptr, true);
1212 void mem_cgroup_commit_charge_swapin(struct page *page, struct mem_cgroup *ptr)
1214 struct page_cgroup *pc;
1216 if (mem_cgroup_disabled())
1220 pc = lookup_page_cgroup(page);
1221 mem_cgroup_lru_del_before_commit_swapcache(page);
1222 __mem_cgroup_commit_charge(ptr, pc, MEM_CGROUP_CHARGE_TYPE_MAPPED);
1223 mem_cgroup_lru_add_after_commit_swapcache(page);
1225 * Now swap is on-memory. This means this page may be
1226 * counted both as mem and swap....double count.
1227 * Fix it by uncharging from memsw. Basically, this SwapCache is stable
1228 * under lock_page(). But in do_swap_page()::memory.c, reuse_swap_page()
1229 * may call delete_from_swap_cache() before reach here.
1231 if (do_swap_account && PageSwapCache(page)) {
1232 swp_entry_t ent = {.val = page_private(page)};
1233 struct mem_cgroup *memcg;
1234 memcg = swap_cgroup_record(ent, NULL);
1236 res_counter_uncharge(&memcg->memsw, PAGE_SIZE);
1237 mem_cgroup_put(memcg);
1241 /* add this page(page_cgroup) to the LRU we want. */
1245 void mem_cgroup_cancel_charge_swapin(struct mem_cgroup *mem)
1247 if (mem_cgroup_disabled())
1251 res_counter_uncharge(&mem->res, PAGE_SIZE);
1252 if (do_swap_account)
1253 res_counter_uncharge(&mem->memsw, PAGE_SIZE);
1259 * uncharge if !page_mapped(page)
1261 static struct mem_cgroup *
1262 __mem_cgroup_uncharge_common(struct page *page, enum charge_type ctype)
1264 struct page_cgroup *pc;
1265 struct mem_cgroup *mem = NULL;
1266 struct mem_cgroup_per_zone *mz;
1268 if (mem_cgroup_disabled())
1271 if (PageSwapCache(page))
1275 * Check if our page_cgroup is valid
1277 pc = lookup_page_cgroup(page);
1278 if (unlikely(!pc || !PageCgroupUsed(pc)))
1281 lock_page_cgroup(pc);
1283 mem = pc->mem_cgroup;
1285 if (!PageCgroupUsed(pc))
1289 case MEM_CGROUP_CHARGE_TYPE_MAPPED:
1290 if (page_mapped(page))
1293 case MEM_CGROUP_CHARGE_TYPE_SWAPOUT:
1294 if (!PageAnon(page)) { /* Shared memory */
1295 if (page->mapping && !page_is_file_cache(page))
1297 } else if (page_mapped(page)) /* Anon */
1304 res_counter_uncharge(&mem->res, PAGE_SIZE);
1305 if (do_swap_account && (ctype != MEM_CGROUP_CHARGE_TYPE_SWAPOUT))
1306 res_counter_uncharge(&mem->memsw, PAGE_SIZE);
1308 mem_cgroup_charge_statistics(mem, pc, false);
1309 ClearPageCgroupUsed(pc);
1311 * pc->mem_cgroup is not cleared here. It will be accessed when it's
1312 * freed from LRU. This is safe because uncharged page is expected not
1313 * to be reused (freed soon). Exception is SwapCache, it's handled by
1314 * special functions.
1317 mz = page_cgroup_zoneinfo(pc);
1318 unlock_page_cgroup(pc);
1320 /* at swapout, this memcg will be accessed to record to swap */
1321 if (ctype != MEM_CGROUP_CHARGE_TYPE_SWAPOUT)
1327 unlock_page_cgroup(pc);
1331 void mem_cgroup_uncharge_page(struct page *page)
1334 if (page_mapped(page))
1336 if (page->mapping && !PageAnon(page))
1338 __mem_cgroup_uncharge_common(page, MEM_CGROUP_CHARGE_TYPE_MAPPED);
1341 void mem_cgroup_uncharge_cache_page(struct page *page)
1343 VM_BUG_ON(page_mapped(page));
1344 VM_BUG_ON(page->mapping);
1345 __mem_cgroup_uncharge_common(page, MEM_CGROUP_CHARGE_TYPE_CACHE);
1349 * called from __delete_from_swap_cache() and drop "page" account.
1350 * memcg information is recorded to swap_cgroup of "ent"
1352 void mem_cgroup_uncharge_swapcache(struct page *page, swp_entry_t ent)
1354 struct mem_cgroup *memcg;
1356 memcg = __mem_cgroup_uncharge_common(page,
1357 MEM_CGROUP_CHARGE_TYPE_SWAPOUT);
1358 /* record memcg information */
1359 if (do_swap_account && memcg) {
1360 swap_cgroup_record(ent, memcg);
1361 mem_cgroup_get(memcg);
1364 css_put(&memcg->css);
1367 #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP
1369 * called from swap_entry_free(). remove record in swap_cgroup and
1370 * uncharge "memsw" account.
1372 void mem_cgroup_uncharge_swap(swp_entry_t ent)
1374 struct mem_cgroup *memcg;
1376 if (!do_swap_account)
1379 memcg = swap_cgroup_record(ent, NULL);
1381 res_counter_uncharge(&memcg->memsw, PAGE_SIZE);
1382 mem_cgroup_put(memcg);
1388 * Before starting migration, account PAGE_SIZE to mem_cgroup that the old
1391 int mem_cgroup_prepare_migration(struct page *page, struct mem_cgroup **ptr)
1393 struct page_cgroup *pc;
1394 struct mem_cgroup *mem = NULL;
1397 if (mem_cgroup_disabled())
1400 pc = lookup_page_cgroup(page);
1401 lock_page_cgroup(pc);
1402 if (PageCgroupUsed(pc)) {
1403 mem = pc->mem_cgroup;
1406 unlock_page_cgroup(pc);
1409 ret = __mem_cgroup_try_charge(NULL, GFP_KERNEL, &mem, false);
1416 /* remove redundant charge if migration failed*/
1417 void mem_cgroup_end_migration(struct mem_cgroup *mem,
1418 struct page *oldpage, struct page *newpage)
1420 struct page *target, *unused;
1421 struct page_cgroup *pc;
1422 enum charge_type ctype;
1427 /* at migration success, oldpage->mapping is NULL. */
1428 if (oldpage->mapping) {
1436 if (PageAnon(target))
1437 ctype = MEM_CGROUP_CHARGE_TYPE_MAPPED;
1438 else if (page_is_file_cache(target))
1439 ctype = MEM_CGROUP_CHARGE_TYPE_CACHE;
1441 ctype = MEM_CGROUP_CHARGE_TYPE_SHMEM;
1443 /* unused page is not on radix-tree now. */
1445 __mem_cgroup_uncharge_common(unused, ctype);
1447 pc = lookup_page_cgroup(target);
1449 * __mem_cgroup_commit_charge() check PCG_USED bit of page_cgroup.
1450 * So, double-counting is effectively avoided.
1452 __mem_cgroup_commit_charge(mem, pc, ctype);
1455 * Both of oldpage and newpage are still under lock_page().
1456 * Then, we don't have to care about race in radix-tree.
1457 * But we have to be careful that this page is unmapped or not.
1459 * There is a case for !page_mapped(). At the start of
1460 * migration, oldpage was mapped. But now, it's zapped.
1461 * But we know *target* page is not freed/reused under us.
1462 * mem_cgroup_uncharge_page() does all necessary checks.
1464 if (ctype == MEM_CGROUP_CHARGE_TYPE_MAPPED)
1465 mem_cgroup_uncharge_page(target);
1469 * A call to try to shrink memory usage under specified resource controller.
1470 * This is typically used for page reclaiming for shmem for reducing side
1471 * effect of page allocation from shmem, which is used by some mem_cgroup.
1473 int mem_cgroup_shrink_usage(struct page *page,
1474 struct mm_struct *mm,
1477 struct mem_cgroup *mem = NULL;
1479 int retry = MEM_CGROUP_RECLAIM_RETRIES;
1481 if (mem_cgroup_disabled())
1484 mem = try_get_mem_cgroup_from_swapcache(page);
1486 mem = try_get_mem_cgroup_from_mm(mm);
1491 progress = mem_cgroup_hierarchical_reclaim(mem, gfp_mask, true);
1492 progress += mem_cgroup_check_under_limit(mem);
1493 } while (!progress && --retry);
1501 static DEFINE_MUTEX(set_limit_mutex);
1503 static int mem_cgroup_resize_limit(struct mem_cgroup *memcg,
1504 unsigned long long val)
1507 int retry_count = MEM_CGROUP_RECLAIM_RETRIES;
1512 while (retry_count) {
1513 if (signal_pending(current)) {
1518 * Rather than hide all in some function, I do this in
1519 * open coded manner. You see what this really does.
1520 * We have to guarantee mem->res.limit < mem->memsw.limit.
1522 mutex_lock(&set_limit_mutex);
1523 memswlimit = res_counter_read_u64(&memcg->memsw, RES_LIMIT);
1524 if (memswlimit < val) {
1526 mutex_unlock(&set_limit_mutex);
1529 ret = res_counter_set_limit(&memcg->res, val);
1530 mutex_unlock(&set_limit_mutex);
1535 progress = mem_cgroup_hierarchical_reclaim(memcg, GFP_KERNEL,
1537 if (!progress) retry_count--;
1543 int mem_cgroup_resize_memsw_limit(struct mem_cgroup *memcg,
1544 unsigned long long val)
1546 int retry_count = MEM_CGROUP_RECLAIM_RETRIES;
1547 u64 memlimit, oldusage, curusage;
1550 if (!do_swap_account)
1553 while (retry_count) {
1554 if (signal_pending(current)) {
1559 * Rather than hide all in some function, I do this in
1560 * open coded manner. You see what this really does.
1561 * We have to guarantee mem->res.limit < mem->memsw.limit.
1563 mutex_lock(&set_limit_mutex);
1564 memlimit = res_counter_read_u64(&memcg->res, RES_LIMIT);
1565 if (memlimit > val) {
1567 mutex_unlock(&set_limit_mutex);
1570 ret = res_counter_set_limit(&memcg->memsw, val);
1571 mutex_unlock(&set_limit_mutex);
1576 oldusage = res_counter_read_u64(&memcg->memsw, RES_USAGE);
1577 mem_cgroup_hierarchical_reclaim(memcg, GFP_KERNEL, true);
1578 curusage = res_counter_read_u64(&memcg->memsw, RES_USAGE);
1579 if (curusage >= oldusage)
1586 * This routine traverse page_cgroup in given list and drop them all.
1587 * *And* this routine doesn't reclaim page itself, just removes page_cgroup.
1589 static int mem_cgroup_force_empty_list(struct mem_cgroup *mem,
1590 int node, int zid, enum lru_list lru)
1593 struct mem_cgroup_per_zone *mz;
1594 struct page_cgroup *pc, *busy;
1595 unsigned long flags, loop;
1596 struct list_head *list;
1599 zone = &NODE_DATA(node)->node_zones[zid];
1600 mz = mem_cgroup_zoneinfo(mem, node, zid);
1601 list = &mz->lists[lru];
1603 loop = MEM_CGROUP_ZSTAT(mz, lru);
1604 /* give some margin against EBUSY etc...*/
1609 spin_lock_irqsave(&zone->lru_lock, flags);
1610 if (list_empty(list)) {
1611 spin_unlock_irqrestore(&zone->lru_lock, flags);
1614 pc = list_entry(list->prev, struct page_cgroup, lru);
1616 list_move(&pc->lru, list);
1618 spin_unlock_irqrestore(&zone->lru_lock, flags);
1621 spin_unlock_irqrestore(&zone->lru_lock, flags);
1623 ret = mem_cgroup_move_parent(pc, mem, GFP_KERNEL);
1627 if (ret == -EBUSY || ret == -EINVAL) {
1628 /* found lock contention or "pc" is obsolete. */
1635 if (!ret && !list_empty(list))
1641 * make mem_cgroup's charge to be 0 if there is no task.
1642 * This enables deleting this mem_cgroup.
1644 static int mem_cgroup_force_empty(struct mem_cgroup *mem, bool free_all)
1647 int node, zid, shrink;
1648 int nr_retries = MEM_CGROUP_RECLAIM_RETRIES;
1649 struct cgroup *cgrp = mem->css.cgroup;
1654 /* should free all ? */
1658 while (mem->res.usage > 0) {
1660 if (cgroup_task_count(cgrp) || !list_empty(&cgrp->children))
1663 if (signal_pending(current))
1665 /* This is for making all *used* pages to be on LRU. */
1666 lru_add_drain_all();
1668 for_each_node_state(node, N_POSSIBLE) {
1669 for (zid = 0; !ret && zid < MAX_NR_ZONES; zid++) {
1672 ret = mem_cgroup_force_empty_list(mem,
1681 /* it seems parent cgroup doesn't have enough mem */
1692 /* returns EBUSY if there is a task or if we come here twice. */
1693 if (cgroup_task_count(cgrp) || !list_empty(&cgrp->children) || shrink) {
1697 /* we call try-to-free pages for make this cgroup empty */
1698 lru_add_drain_all();
1699 /* try to free all pages in this cgroup */
1701 while (nr_retries && mem->res.usage > 0) {
1704 if (signal_pending(current)) {
1708 progress = try_to_free_mem_cgroup_pages(mem, GFP_KERNEL,
1709 false, get_swappiness(mem));
1712 /* maybe some writeback is necessary */
1713 congestion_wait(WRITE, HZ/10);
1718 /* try move_account...there may be some *locked* pages. */
1725 int mem_cgroup_force_empty_write(struct cgroup *cont, unsigned int event)
1727 return mem_cgroup_force_empty(mem_cgroup_from_cont(cont), true);
1731 static u64 mem_cgroup_hierarchy_read(struct cgroup *cont, struct cftype *cft)
1733 return mem_cgroup_from_cont(cont)->use_hierarchy;
1736 static int mem_cgroup_hierarchy_write(struct cgroup *cont, struct cftype *cft,
1740 struct mem_cgroup *mem = mem_cgroup_from_cont(cont);
1741 struct cgroup *parent = cont->parent;
1742 struct mem_cgroup *parent_mem = NULL;
1745 parent_mem = mem_cgroup_from_cont(parent);
1749 * If parent's use_hiearchy is set, we can't make any modifications
1750 * in the child subtrees. If it is unset, then the change can
1751 * occur, provided the current cgroup has no children.
1753 * For the root cgroup, parent_mem is NULL, we allow value to be
1754 * set if there are no children.
1756 if ((!parent_mem || !parent_mem->use_hierarchy) &&
1757 (val == 1 || val == 0)) {
1758 if (list_empty(&cont->children))
1759 mem->use_hierarchy = val;
1769 static u64 mem_cgroup_read(struct cgroup *cont, struct cftype *cft)
1771 struct mem_cgroup *mem = mem_cgroup_from_cont(cont);
1775 type = MEMFILE_TYPE(cft->private);
1776 name = MEMFILE_ATTR(cft->private);
1779 val = res_counter_read_u64(&mem->res, name);
1782 if (do_swap_account)
1783 val = res_counter_read_u64(&mem->memsw, name);
1792 * The user of this function is...
1795 static int mem_cgroup_write(struct cgroup *cont, struct cftype *cft,
1798 struct mem_cgroup *memcg = mem_cgroup_from_cont(cont);
1800 unsigned long long val;
1803 type = MEMFILE_TYPE(cft->private);
1804 name = MEMFILE_ATTR(cft->private);
1807 /* This function does all necessary parse...reuse it */
1808 ret = res_counter_memparse_write_strategy(buffer, &val);
1812 ret = mem_cgroup_resize_limit(memcg, val);
1814 ret = mem_cgroup_resize_memsw_limit(memcg, val);
1817 ret = -EINVAL; /* should be BUG() ? */
1823 static void memcg_get_hierarchical_limit(struct mem_cgroup *memcg,
1824 unsigned long long *mem_limit, unsigned long long *memsw_limit)
1826 struct cgroup *cgroup;
1827 unsigned long long min_limit, min_memsw_limit, tmp;
1829 min_limit = res_counter_read_u64(&memcg->res, RES_LIMIT);
1830 min_memsw_limit = res_counter_read_u64(&memcg->memsw, RES_LIMIT);
1831 cgroup = memcg->css.cgroup;
1832 if (!memcg->use_hierarchy)
1835 while (cgroup->parent) {
1836 cgroup = cgroup->parent;
1837 memcg = mem_cgroup_from_cont(cgroup);
1838 if (!memcg->use_hierarchy)
1840 tmp = res_counter_read_u64(&memcg->res, RES_LIMIT);
1841 min_limit = min(min_limit, tmp);
1842 tmp = res_counter_read_u64(&memcg->memsw, RES_LIMIT);
1843 min_memsw_limit = min(min_memsw_limit, tmp);
1846 *mem_limit = min_limit;
1847 *memsw_limit = min_memsw_limit;
1851 static int mem_cgroup_reset(struct cgroup *cont, unsigned int event)
1853 struct mem_cgroup *mem;
1856 mem = mem_cgroup_from_cont(cont);
1857 type = MEMFILE_TYPE(event);
1858 name = MEMFILE_ATTR(event);
1862 res_counter_reset_max(&mem->res);
1864 res_counter_reset_max(&mem->memsw);
1868 res_counter_reset_failcnt(&mem->res);
1870 res_counter_reset_failcnt(&mem->memsw);
1876 static const struct mem_cgroup_stat_desc {
1879 } mem_cgroup_stat_desc[] = {
1880 [MEM_CGROUP_STAT_CACHE] = { "cache", PAGE_SIZE, },
1881 [MEM_CGROUP_STAT_RSS] = { "rss", PAGE_SIZE, },
1882 [MEM_CGROUP_STAT_PGPGIN_COUNT] = {"pgpgin", 1, },
1883 [MEM_CGROUP_STAT_PGPGOUT_COUNT] = {"pgpgout", 1, },
1886 static int mem_control_stat_show(struct cgroup *cont, struct cftype *cft,
1887 struct cgroup_map_cb *cb)
1889 struct mem_cgroup *mem_cont = mem_cgroup_from_cont(cont);
1890 struct mem_cgroup_stat *stat = &mem_cont->stat;
1893 for (i = 0; i < ARRAY_SIZE(stat->cpustat[0].count); i++) {
1896 val = mem_cgroup_read_stat(stat, i);
1897 val *= mem_cgroup_stat_desc[i].unit;
1898 cb->fill(cb, mem_cgroup_stat_desc[i].msg, val);
1900 /* showing # of active pages */
1902 unsigned long active_anon, inactive_anon;
1903 unsigned long active_file, inactive_file;
1904 unsigned long unevictable;
1906 inactive_anon = mem_cgroup_get_all_zonestat(mem_cont,
1908 active_anon = mem_cgroup_get_all_zonestat(mem_cont,
1910 inactive_file = mem_cgroup_get_all_zonestat(mem_cont,
1912 active_file = mem_cgroup_get_all_zonestat(mem_cont,
1914 unevictable = mem_cgroup_get_all_zonestat(mem_cont,
1917 cb->fill(cb, "active_anon", (active_anon) * PAGE_SIZE);
1918 cb->fill(cb, "inactive_anon", (inactive_anon) * PAGE_SIZE);
1919 cb->fill(cb, "active_file", (active_file) * PAGE_SIZE);
1920 cb->fill(cb, "inactive_file", (inactive_file) * PAGE_SIZE);
1921 cb->fill(cb, "unevictable", unevictable * PAGE_SIZE);
1925 unsigned long long limit, memsw_limit;
1926 memcg_get_hierarchical_limit(mem_cont, &limit, &memsw_limit);
1927 cb->fill(cb, "hierarchical_memory_limit", limit);
1928 if (do_swap_account)
1929 cb->fill(cb, "hierarchical_memsw_limit", memsw_limit);
1932 #ifdef CONFIG_DEBUG_VM
1933 cb->fill(cb, "inactive_ratio", calc_inactive_ratio(mem_cont, NULL));
1937 struct mem_cgroup_per_zone *mz;
1938 unsigned long recent_rotated[2] = {0, 0};
1939 unsigned long recent_scanned[2] = {0, 0};
1941 for_each_online_node(nid)
1942 for (zid = 0; zid < MAX_NR_ZONES; zid++) {
1943 mz = mem_cgroup_zoneinfo(mem_cont, nid, zid);
1945 recent_rotated[0] +=
1946 mz->reclaim_stat.recent_rotated[0];
1947 recent_rotated[1] +=
1948 mz->reclaim_stat.recent_rotated[1];
1949 recent_scanned[0] +=
1950 mz->reclaim_stat.recent_scanned[0];
1951 recent_scanned[1] +=
1952 mz->reclaim_stat.recent_scanned[1];
1954 cb->fill(cb, "recent_rotated_anon", recent_rotated[0]);
1955 cb->fill(cb, "recent_rotated_file", recent_rotated[1]);
1956 cb->fill(cb, "recent_scanned_anon", recent_scanned[0]);
1957 cb->fill(cb, "recent_scanned_file", recent_scanned[1]);
1964 static u64 mem_cgroup_swappiness_read(struct cgroup *cgrp, struct cftype *cft)
1966 struct mem_cgroup *memcg = mem_cgroup_from_cont(cgrp);
1968 return get_swappiness(memcg);
1971 static int mem_cgroup_swappiness_write(struct cgroup *cgrp, struct cftype *cft,
1974 struct mem_cgroup *memcg = mem_cgroup_from_cont(cgrp);
1975 struct mem_cgroup *parent;
1979 if (cgrp->parent == NULL)
1982 parent = mem_cgroup_from_cont(cgrp->parent);
1983 /* If under hierarchy, only empty-root can set this value */
1984 if ((parent->use_hierarchy) ||
1985 (memcg->use_hierarchy && !list_empty(&cgrp->children)))
1988 spin_lock(&memcg->reclaim_param_lock);
1989 memcg->swappiness = val;
1990 spin_unlock(&memcg->reclaim_param_lock);
1996 static struct cftype mem_cgroup_files[] = {
1998 .name = "usage_in_bytes",
1999 .private = MEMFILE_PRIVATE(_MEM, RES_USAGE),
2000 .read_u64 = mem_cgroup_read,
2003 .name = "max_usage_in_bytes",
2004 .private = MEMFILE_PRIVATE(_MEM, RES_MAX_USAGE),
2005 .trigger = mem_cgroup_reset,
2006 .read_u64 = mem_cgroup_read,
2009 .name = "limit_in_bytes",
2010 .private = MEMFILE_PRIVATE(_MEM, RES_LIMIT),
2011 .write_string = mem_cgroup_write,
2012 .read_u64 = mem_cgroup_read,
2016 .private = MEMFILE_PRIVATE(_MEM, RES_FAILCNT),
2017 .trigger = mem_cgroup_reset,
2018 .read_u64 = mem_cgroup_read,
2022 .read_map = mem_control_stat_show,
2025 .name = "force_empty",
2026 .trigger = mem_cgroup_force_empty_write,
2029 .name = "use_hierarchy",
2030 .write_u64 = mem_cgroup_hierarchy_write,
2031 .read_u64 = mem_cgroup_hierarchy_read,
2034 .name = "swappiness",
2035 .read_u64 = mem_cgroup_swappiness_read,
2036 .write_u64 = mem_cgroup_swappiness_write,
2040 #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP
2041 static struct cftype memsw_cgroup_files[] = {
2043 .name = "memsw.usage_in_bytes",
2044 .private = MEMFILE_PRIVATE(_MEMSWAP, RES_USAGE),
2045 .read_u64 = mem_cgroup_read,
2048 .name = "memsw.max_usage_in_bytes",
2049 .private = MEMFILE_PRIVATE(_MEMSWAP, RES_MAX_USAGE),
2050 .trigger = mem_cgroup_reset,
2051 .read_u64 = mem_cgroup_read,
2054 .name = "memsw.limit_in_bytes",
2055 .private = MEMFILE_PRIVATE(_MEMSWAP, RES_LIMIT),
2056 .write_string = mem_cgroup_write,
2057 .read_u64 = mem_cgroup_read,
2060 .name = "memsw.failcnt",
2061 .private = MEMFILE_PRIVATE(_MEMSWAP, RES_FAILCNT),
2062 .trigger = mem_cgroup_reset,
2063 .read_u64 = mem_cgroup_read,
2067 static int register_memsw_files(struct cgroup *cont, struct cgroup_subsys *ss)
2069 if (!do_swap_account)
2071 return cgroup_add_files(cont, ss, memsw_cgroup_files,
2072 ARRAY_SIZE(memsw_cgroup_files));
2075 static int register_memsw_files(struct cgroup *cont, struct cgroup_subsys *ss)
2081 static int alloc_mem_cgroup_per_zone_info(struct mem_cgroup *mem, int node)
2083 struct mem_cgroup_per_node *pn;
2084 struct mem_cgroup_per_zone *mz;
2086 int zone, tmp = node;
2088 * This routine is called against possible nodes.
2089 * But it's BUG to call kmalloc() against offline node.
2091 * TODO: this routine can waste much memory for nodes which will
2092 * never be onlined. It's better to use memory hotplug callback
2095 if (!node_state(node, N_NORMAL_MEMORY))
2097 pn = kmalloc_node(sizeof(*pn), GFP_KERNEL, tmp);
2101 mem->info.nodeinfo[node] = pn;
2102 memset(pn, 0, sizeof(*pn));
2104 for (zone = 0; zone < MAX_NR_ZONES; zone++) {
2105 mz = &pn->zoneinfo[zone];
2107 INIT_LIST_HEAD(&mz->lists[l]);
2112 static void free_mem_cgroup_per_zone_info(struct mem_cgroup *mem, int node)
2114 kfree(mem->info.nodeinfo[node]);
2117 static int mem_cgroup_size(void)
2119 int cpustat_size = nr_cpu_ids * sizeof(struct mem_cgroup_stat_cpu);
2120 return sizeof(struct mem_cgroup) + cpustat_size;
2123 static struct mem_cgroup *mem_cgroup_alloc(void)
2125 struct mem_cgroup *mem;
2126 int size = mem_cgroup_size();
2128 if (size < PAGE_SIZE)
2129 mem = kmalloc(size, GFP_KERNEL);
2131 mem = vmalloc(size);
2134 memset(mem, 0, size);
2139 * At destroying mem_cgroup, references from swap_cgroup can remain.
2140 * (scanning all at force_empty is too costly...)
2142 * Instead of clearing all references at force_empty, we remember
2143 * the number of reference from swap_cgroup and free mem_cgroup when
2144 * it goes down to 0.
2146 * Removal of cgroup itself succeeds regardless of refs from swap.
2149 static void __mem_cgroup_free(struct mem_cgroup *mem)
2153 for_each_node_state(node, N_POSSIBLE)
2154 free_mem_cgroup_per_zone_info(mem, node);
2156 if (mem_cgroup_size() < PAGE_SIZE)
2162 static void mem_cgroup_get(struct mem_cgroup *mem)
2164 atomic_inc(&mem->refcnt);
2167 static void mem_cgroup_put(struct mem_cgroup *mem)
2169 if (atomic_dec_and_test(&mem->refcnt))
2170 __mem_cgroup_free(mem);
2174 #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP
2175 static void __init enable_swap_cgroup(void)
2177 if (!mem_cgroup_disabled() && really_do_swap_account)
2178 do_swap_account = 1;
2181 static void __init enable_swap_cgroup(void)
2186 static struct cgroup_subsys_state *
2187 mem_cgroup_create(struct cgroup_subsys *ss, struct cgroup *cont)
2189 struct mem_cgroup *mem, *parent;
2192 mem = mem_cgroup_alloc();
2194 return ERR_PTR(-ENOMEM);
2196 for_each_node_state(node, N_POSSIBLE)
2197 if (alloc_mem_cgroup_per_zone_info(mem, node))
2200 if (cont->parent == NULL) {
2201 enable_swap_cgroup();
2204 parent = mem_cgroup_from_cont(cont->parent);
2205 mem->use_hierarchy = parent->use_hierarchy;
2208 if (parent && parent->use_hierarchy) {
2209 res_counter_init(&mem->res, &parent->res);
2210 res_counter_init(&mem->memsw, &parent->memsw);
2212 res_counter_init(&mem->res, NULL);
2213 res_counter_init(&mem->memsw, NULL);
2215 mem->last_scanned_child = NULL;
2216 spin_lock_init(&mem->reclaim_param_lock);
2219 mem->swappiness = get_swappiness(parent);
2220 atomic_set(&mem->refcnt, 1);
2223 __mem_cgroup_free(mem);
2224 return ERR_PTR(-ENOMEM);
2227 static void mem_cgroup_pre_destroy(struct cgroup_subsys *ss,
2228 struct cgroup *cont)
2230 struct mem_cgroup *mem = mem_cgroup_from_cont(cont);
2231 mem_cgroup_force_empty(mem, false);
2234 static void mem_cgroup_destroy(struct cgroup_subsys *ss,
2235 struct cgroup *cont)
2237 mem_cgroup_put(mem_cgroup_from_cont(cont));
2240 static int mem_cgroup_populate(struct cgroup_subsys *ss,
2241 struct cgroup *cont)
2245 ret = cgroup_add_files(cont, ss, mem_cgroup_files,
2246 ARRAY_SIZE(mem_cgroup_files));
2249 ret = register_memsw_files(cont, ss);
2253 static void mem_cgroup_move_task(struct cgroup_subsys *ss,
2254 struct cgroup *cont,
2255 struct cgroup *old_cont,
2256 struct task_struct *p)
2258 mutex_lock(&memcg_tasklist);
2260 * FIXME: It's better to move charges of this process from old
2261 * memcg to new memcg. But it's just on TODO-List now.
2263 mutex_unlock(&memcg_tasklist);
2266 struct cgroup_subsys mem_cgroup_subsys = {
2268 .subsys_id = mem_cgroup_subsys_id,
2269 .create = mem_cgroup_create,
2270 .pre_destroy = mem_cgroup_pre_destroy,
2271 .destroy = mem_cgroup_destroy,
2272 .populate = mem_cgroup_populate,
2273 .attach = mem_cgroup_move_task,
2277 #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP
2279 static int __init disable_swap_account(char *s)
2281 really_do_swap_account = 0;
2284 __setup("noswapaccount", disable_swap_account);