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/smp.h>
25 #include <linux/page-flags.h>
26 #include <linux/backing-dev.h>
27 #include <linux/bit_spinlock.h>
28 #include <linux/rcupdate.h>
29 #include <linux/swap.h>
30 #include <linux/spinlock.h>
32 #include <linux/seq_file.h>
34 #include <asm/uaccess.h>
36 struct cgroup_subsys mem_cgroup_subsys;
37 static const int MEM_CGROUP_RECLAIM_RETRIES = 5;
40 * Statistics for memory cgroup.
42 enum mem_cgroup_stat_index {
44 * For MEM_CONTAINER_TYPE_ALL, usage = pagecache + rss.
46 MEM_CGROUP_STAT_CACHE, /* # of pages charged as cache */
47 MEM_CGROUP_STAT_RSS, /* # of pages charged as rss */
49 MEM_CGROUP_STAT_NSTATS,
52 struct mem_cgroup_stat_cpu {
53 s64 count[MEM_CGROUP_STAT_NSTATS];
54 } ____cacheline_aligned_in_smp;
56 struct mem_cgroup_stat {
57 struct mem_cgroup_stat_cpu cpustat[NR_CPUS];
61 * For accounting under irq disable, no need for increment preempt count.
63 static void __mem_cgroup_stat_add_safe(struct mem_cgroup_stat *stat,
64 enum mem_cgroup_stat_index idx, int val)
66 int cpu = smp_processor_id();
67 stat->cpustat[cpu].count[idx] += val;
70 static s64 mem_cgroup_read_stat(struct mem_cgroup_stat *stat,
71 enum mem_cgroup_stat_index idx)
75 for_each_possible_cpu(cpu)
76 ret += stat->cpustat[cpu].count[idx];
81 * per-zone information in memory controller.
84 enum mem_cgroup_zstat_index {
85 MEM_CGROUP_ZSTAT_ACTIVE,
86 MEM_CGROUP_ZSTAT_INACTIVE,
91 struct mem_cgroup_per_zone {
93 * spin_lock to protect the per cgroup LRU
96 struct list_head active_list;
97 struct list_head inactive_list;
98 unsigned long count[NR_MEM_CGROUP_ZSTAT];
100 /* Macro for accessing counter */
101 #define MEM_CGROUP_ZSTAT(mz, idx) ((mz)->count[(idx)])
103 struct mem_cgroup_per_node {
104 struct mem_cgroup_per_zone zoneinfo[MAX_NR_ZONES];
107 struct mem_cgroup_lru_info {
108 struct mem_cgroup_per_node *nodeinfo[MAX_NUMNODES];
112 * The memory controller data structure. The memory controller controls both
113 * page cache and RSS per cgroup. We would eventually like to provide
114 * statistics based on the statistics developed by Rik Van Riel for clock-pro,
115 * to help the administrator determine what knobs to tune.
117 * TODO: Add a water mark for the memory controller. Reclaim will begin when
118 * we hit the water mark. May be even add a low water mark, such that
119 * no reclaim occurs from a cgroup at it's low water mark, this is
120 * a feature that will be implemented much later in the future.
123 struct cgroup_subsys_state css;
125 * the counter to account for memory usage
127 struct res_counter res;
129 * Per cgroup active and inactive list, similar to the
130 * per zone LRU lists.
132 struct mem_cgroup_lru_info info;
134 int prev_priority; /* for recording reclaim priority */
138 struct mem_cgroup_stat stat;
140 static struct mem_cgroup init_mem_cgroup;
143 * We use the lower bit of the page->page_cgroup pointer as a bit spin
144 * lock. We need to ensure that page->page_cgroup is at least two
145 * byte aligned (based on comments from Nick Piggin). But since
146 * bit_spin_lock doesn't actually set that lock bit in a non-debug
147 * uniprocessor kernel, we should avoid setting it here too.
149 #define PAGE_CGROUP_LOCK_BIT 0x0
150 #if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK)
151 #define PAGE_CGROUP_LOCK (1 << PAGE_CGROUP_LOCK_BIT)
153 #define PAGE_CGROUP_LOCK 0x0
157 * A page_cgroup page is associated with every page descriptor. The
158 * page_cgroup helps us identify information about the cgroup
161 struct list_head lru; /* per cgroup LRU list */
163 struct mem_cgroup *mem_cgroup;
164 int ref_cnt; /* cached, mapped, migrating */
167 #define PAGE_CGROUP_FLAG_CACHE (0x1) /* charged as cache */
168 #define PAGE_CGROUP_FLAG_ACTIVE (0x2) /* page is active in this cgroup */
170 static int page_cgroup_nid(struct page_cgroup *pc)
172 return page_to_nid(pc->page);
175 static enum zone_type page_cgroup_zid(struct page_cgroup *pc)
177 return page_zonenum(pc->page);
181 MEM_CGROUP_CHARGE_TYPE_CACHE = 0,
182 MEM_CGROUP_CHARGE_TYPE_MAPPED,
186 * Always modified under lru lock. Then, not necessary to preempt_disable()
188 static void mem_cgroup_charge_statistics(struct mem_cgroup *mem, int flags,
191 int val = (charge)? 1 : -1;
192 struct mem_cgroup_stat *stat = &mem->stat;
194 VM_BUG_ON(!irqs_disabled());
195 if (flags & PAGE_CGROUP_FLAG_CACHE)
196 __mem_cgroup_stat_add_safe(stat, MEM_CGROUP_STAT_CACHE, val);
198 __mem_cgroup_stat_add_safe(stat, MEM_CGROUP_STAT_RSS, val);
201 static struct mem_cgroup_per_zone *
202 mem_cgroup_zoneinfo(struct mem_cgroup *mem, int nid, int zid)
204 return &mem->info.nodeinfo[nid]->zoneinfo[zid];
207 static struct mem_cgroup_per_zone *
208 page_cgroup_zoneinfo(struct page_cgroup *pc)
210 struct mem_cgroup *mem = pc->mem_cgroup;
211 int nid = page_cgroup_nid(pc);
212 int zid = page_cgroup_zid(pc);
214 return mem_cgroup_zoneinfo(mem, nid, zid);
217 static unsigned long mem_cgroup_get_all_zonestat(struct mem_cgroup *mem,
218 enum mem_cgroup_zstat_index idx)
221 struct mem_cgroup_per_zone *mz;
224 for_each_online_node(nid)
225 for (zid = 0; zid < MAX_NR_ZONES; zid++) {
226 mz = mem_cgroup_zoneinfo(mem, nid, zid);
227 total += MEM_CGROUP_ZSTAT(mz, idx);
232 static struct mem_cgroup *mem_cgroup_from_cont(struct cgroup *cont)
234 return container_of(cgroup_subsys_state(cont,
235 mem_cgroup_subsys_id), struct mem_cgroup,
239 struct mem_cgroup *mem_cgroup_from_task(struct task_struct *p)
241 return container_of(task_subsys_state(p, mem_cgroup_subsys_id),
242 struct mem_cgroup, css);
245 static inline int page_cgroup_locked(struct page *page)
247 return bit_spin_is_locked(PAGE_CGROUP_LOCK_BIT, &page->page_cgroup);
250 static void page_assign_page_cgroup(struct page *page, struct page_cgroup *pc)
252 VM_BUG_ON(!page_cgroup_locked(page));
253 page->page_cgroup = ((unsigned long)pc | PAGE_CGROUP_LOCK);
256 struct page_cgroup *page_get_page_cgroup(struct page *page)
258 return (struct page_cgroup *) (page->page_cgroup & ~PAGE_CGROUP_LOCK);
261 static void lock_page_cgroup(struct page *page)
263 bit_spin_lock(PAGE_CGROUP_LOCK_BIT, &page->page_cgroup);
266 static int try_lock_page_cgroup(struct page *page)
268 return bit_spin_trylock(PAGE_CGROUP_LOCK_BIT, &page->page_cgroup);
271 static void unlock_page_cgroup(struct page *page)
273 bit_spin_unlock(PAGE_CGROUP_LOCK_BIT, &page->page_cgroup);
276 static void __mem_cgroup_remove_list(struct page_cgroup *pc)
278 int from = pc->flags & PAGE_CGROUP_FLAG_ACTIVE;
279 struct mem_cgroup_per_zone *mz = page_cgroup_zoneinfo(pc);
282 MEM_CGROUP_ZSTAT(mz, MEM_CGROUP_ZSTAT_ACTIVE) -= 1;
284 MEM_CGROUP_ZSTAT(mz, MEM_CGROUP_ZSTAT_INACTIVE) -= 1;
286 mem_cgroup_charge_statistics(pc->mem_cgroup, pc->flags, false);
287 list_del_init(&pc->lru);
290 static void __mem_cgroup_add_list(struct page_cgroup *pc)
292 int to = pc->flags & PAGE_CGROUP_FLAG_ACTIVE;
293 struct mem_cgroup_per_zone *mz = page_cgroup_zoneinfo(pc);
296 MEM_CGROUP_ZSTAT(mz, MEM_CGROUP_ZSTAT_INACTIVE) += 1;
297 list_add(&pc->lru, &mz->inactive_list);
299 MEM_CGROUP_ZSTAT(mz, MEM_CGROUP_ZSTAT_ACTIVE) += 1;
300 list_add(&pc->lru, &mz->active_list);
302 mem_cgroup_charge_statistics(pc->mem_cgroup, pc->flags, true);
305 static void __mem_cgroup_move_lists(struct page_cgroup *pc, bool active)
307 int from = pc->flags & PAGE_CGROUP_FLAG_ACTIVE;
308 struct mem_cgroup_per_zone *mz = page_cgroup_zoneinfo(pc);
311 MEM_CGROUP_ZSTAT(mz, MEM_CGROUP_ZSTAT_ACTIVE) -= 1;
313 MEM_CGROUP_ZSTAT(mz, MEM_CGROUP_ZSTAT_INACTIVE) -= 1;
316 MEM_CGROUP_ZSTAT(mz, MEM_CGROUP_ZSTAT_ACTIVE) += 1;
317 pc->flags |= PAGE_CGROUP_FLAG_ACTIVE;
318 list_move(&pc->lru, &mz->active_list);
320 MEM_CGROUP_ZSTAT(mz, MEM_CGROUP_ZSTAT_INACTIVE) += 1;
321 pc->flags &= ~PAGE_CGROUP_FLAG_ACTIVE;
322 list_move(&pc->lru, &mz->inactive_list);
326 int task_in_mem_cgroup(struct task_struct *task, const struct mem_cgroup *mem)
331 ret = task->mm && mm_match_cgroup(task->mm, mem);
337 * This routine assumes that the appropriate zone's lru lock is already held
339 void mem_cgroup_move_lists(struct page *page, bool active)
341 struct page_cgroup *pc;
342 struct mem_cgroup_per_zone *mz;
346 * We cannot lock_page_cgroup while holding zone's lru_lock,
347 * because other holders of lock_page_cgroup can be interrupted
348 * with an attempt to rotate_reclaimable_page. But we cannot
349 * safely get to page_cgroup without it, so just try_lock it:
350 * mem_cgroup_isolate_pages allows for page left on wrong list.
352 if (!try_lock_page_cgroup(page))
355 pc = page_get_page_cgroup(page);
357 mz = page_cgroup_zoneinfo(pc);
358 spin_lock_irqsave(&mz->lru_lock, flags);
359 __mem_cgroup_move_lists(pc, active);
360 spin_unlock_irqrestore(&mz->lru_lock, flags);
362 unlock_page_cgroup(page);
366 * Calculate mapped_ratio under memory controller. This will be used in
367 * vmscan.c for deteremining we have to reclaim mapped pages.
369 int mem_cgroup_calc_mapped_ratio(struct mem_cgroup *mem)
374 * usage is recorded in bytes. But, here, we assume the number of
375 * physical pages can be represented by "long" on any arch.
377 total = (long) (mem->res.usage >> PAGE_SHIFT) + 1L;
378 rss = (long)mem_cgroup_read_stat(&mem->stat, MEM_CGROUP_STAT_RSS);
379 return (int)((rss * 100L) / total);
383 * This function is called from vmscan.c. In page reclaiming loop. balance
384 * between active and inactive list is calculated. For memory controller
385 * page reclaiming, we should use using mem_cgroup's imbalance rather than
386 * zone's global lru imbalance.
388 long mem_cgroup_reclaim_imbalance(struct mem_cgroup *mem)
390 unsigned long active, inactive;
391 /* active and inactive are the number of pages. 'long' is ok.*/
392 active = mem_cgroup_get_all_zonestat(mem, MEM_CGROUP_ZSTAT_ACTIVE);
393 inactive = mem_cgroup_get_all_zonestat(mem, MEM_CGROUP_ZSTAT_INACTIVE);
394 return (long) (active / (inactive + 1));
398 * prev_priority control...this will be used in memory reclaim path.
400 int mem_cgroup_get_reclaim_priority(struct mem_cgroup *mem)
402 return mem->prev_priority;
405 void mem_cgroup_note_reclaim_priority(struct mem_cgroup *mem, int priority)
407 if (priority < mem->prev_priority)
408 mem->prev_priority = priority;
411 void mem_cgroup_record_reclaim_priority(struct mem_cgroup *mem, int priority)
413 mem->prev_priority = priority;
417 * Calculate # of pages to be scanned in this priority/zone.
420 * priority starts from "DEF_PRIORITY" and decremented in each loop.
421 * (see include/linux/mmzone.h)
424 long mem_cgroup_calc_reclaim_active(struct mem_cgroup *mem,
425 struct zone *zone, int priority)
428 int nid = zone->zone_pgdat->node_id;
429 int zid = zone_idx(zone);
430 struct mem_cgroup_per_zone *mz = mem_cgroup_zoneinfo(mem, nid, zid);
432 nr_active = MEM_CGROUP_ZSTAT(mz, MEM_CGROUP_ZSTAT_ACTIVE);
433 return (nr_active >> priority);
436 long mem_cgroup_calc_reclaim_inactive(struct mem_cgroup *mem,
437 struct zone *zone, int priority)
440 int nid = zone->zone_pgdat->node_id;
441 int zid = zone_idx(zone);
442 struct mem_cgroup_per_zone *mz = mem_cgroup_zoneinfo(mem, nid, zid);
444 nr_inactive = MEM_CGROUP_ZSTAT(mz, MEM_CGROUP_ZSTAT_INACTIVE);
445 return (nr_inactive >> priority);
448 unsigned long mem_cgroup_isolate_pages(unsigned long nr_to_scan,
449 struct list_head *dst,
450 unsigned long *scanned, int order,
451 int mode, struct zone *z,
452 struct mem_cgroup *mem_cont,
455 unsigned long nr_taken = 0;
459 struct list_head *src;
460 struct page_cgroup *pc, *tmp;
461 int nid = z->zone_pgdat->node_id;
462 int zid = zone_idx(z);
463 struct mem_cgroup_per_zone *mz;
466 mz = mem_cgroup_zoneinfo(mem_cont, nid, zid);
468 src = &mz->active_list;
470 src = &mz->inactive_list;
473 spin_lock(&mz->lru_lock);
475 list_for_each_entry_safe_reverse(pc, tmp, src, lru) {
476 if (scan >= nr_to_scan)
480 if (unlikely(!PageLRU(page)))
483 if (PageActive(page) && !active) {
484 __mem_cgroup_move_lists(pc, true);
487 if (!PageActive(page) && active) {
488 __mem_cgroup_move_lists(pc, false);
493 list_move(&pc->lru, &pc_list);
495 if (__isolate_lru_page(page, mode) == 0) {
496 list_move(&page->lru, dst);
501 list_splice(&pc_list, src);
502 spin_unlock(&mz->lru_lock);
509 * Charge the memory controller for page usage.
511 * 0 if the charge was successful
512 * < 0 if the cgroup is over its limit
514 static int mem_cgroup_charge_common(struct page *page, struct mm_struct *mm,
515 gfp_t gfp_mask, enum charge_type ctype)
517 struct mem_cgroup *mem;
518 struct page_cgroup *pc;
520 unsigned long nr_retries = MEM_CGROUP_RECLAIM_RETRIES;
521 struct mem_cgroup_per_zone *mz;
523 if (mem_cgroup_subsys.disabled)
527 * Should page_cgroup's go to their own slab?
528 * One could optimize the performance of the charging routine
529 * by saving a bit in the page_flags and using it as a lock
530 * to see if the cgroup page already has a page_cgroup associated
534 lock_page_cgroup(page);
535 pc = page_get_page_cgroup(page);
537 * The page_cgroup exists and
538 * the page has already been accounted.
541 VM_BUG_ON(pc->page != page);
542 VM_BUG_ON(pc->ref_cnt <= 0);
545 unlock_page_cgroup(page);
548 unlock_page_cgroup(page);
550 pc = kzalloc(sizeof(struct page_cgroup), gfp_mask);
555 * We always charge the cgroup the mm_struct belongs to.
556 * The mm_struct's mem_cgroup changes on task migration if the
557 * thread group leader migrates. It's possible that mm is not
558 * set, if so charge the init_mm (happens for pagecache usage).
564 mem = mem_cgroup_from_task(rcu_dereference(mm->owner));
566 * For every charge from the cgroup, increment reference count
571 while (res_counter_charge(&mem->res, PAGE_SIZE)) {
572 if (!(gfp_mask & __GFP_WAIT))
575 if (try_to_free_mem_cgroup_pages(mem, gfp_mask))
579 * try_to_free_mem_cgroup_pages() might not give us a full
580 * picture of reclaim. Some pages are reclaimed and might be
581 * moved to swap cache or just unmapped from the cgroup.
582 * Check the limit again to see if the reclaim reduced the
583 * current usage of the cgroup before giving up
585 if (res_counter_check_under_limit(&mem->res))
589 mem_cgroup_out_of_memory(mem, gfp_mask);
592 congestion_wait(WRITE, HZ/10);
596 pc->mem_cgroup = mem;
598 pc->flags = PAGE_CGROUP_FLAG_ACTIVE;
599 if (ctype == MEM_CGROUP_CHARGE_TYPE_CACHE)
600 pc->flags |= PAGE_CGROUP_FLAG_CACHE;
602 lock_page_cgroup(page);
603 if (page_get_page_cgroup(page)) {
604 unlock_page_cgroup(page);
606 * Another charge has been added to this page already.
607 * We take lock_page_cgroup(page) again and read
608 * page->cgroup, increment refcnt.... just retry is OK.
610 res_counter_uncharge(&mem->res, PAGE_SIZE);
615 page_assign_page_cgroup(page, pc);
617 mz = page_cgroup_zoneinfo(pc);
618 spin_lock_irqsave(&mz->lru_lock, flags);
619 __mem_cgroup_add_list(pc);
620 spin_unlock_irqrestore(&mz->lru_lock, flags);
622 unlock_page_cgroup(page);
632 int mem_cgroup_charge(struct page *page, struct mm_struct *mm, gfp_t gfp_mask)
634 return mem_cgroup_charge_common(page, mm, gfp_mask,
635 MEM_CGROUP_CHARGE_TYPE_MAPPED);
638 int mem_cgroup_cache_charge(struct page *page, struct mm_struct *mm,
643 return mem_cgroup_charge_common(page, mm, gfp_mask,
644 MEM_CGROUP_CHARGE_TYPE_CACHE);
648 * Uncharging is always a welcome operation, we never complain, simply
651 void mem_cgroup_uncharge_page(struct page *page)
653 struct page_cgroup *pc;
654 struct mem_cgroup *mem;
655 struct mem_cgroup_per_zone *mz;
658 if (mem_cgroup_subsys.disabled)
662 * Check if our page_cgroup is valid
664 lock_page_cgroup(page);
665 pc = page_get_page_cgroup(page);
669 VM_BUG_ON(pc->page != page);
670 VM_BUG_ON(pc->ref_cnt <= 0);
672 if (--(pc->ref_cnt) == 0) {
673 mz = page_cgroup_zoneinfo(pc);
674 spin_lock_irqsave(&mz->lru_lock, flags);
675 __mem_cgroup_remove_list(pc);
676 spin_unlock_irqrestore(&mz->lru_lock, flags);
678 page_assign_page_cgroup(page, NULL);
679 unlock_page_cgroup(page);
681 mem = pc->mem_cgroup;
682 res_counter_uncharge(&mem->res, PAGE_SIZE);
690 unlock_page_cgroup(page);
694 * Returns non-zero if a page (under migration) has valid page_cgroup member.
695 * Refcnt of page_cgroup is incremented.
697 int mem_cgroup_prepare_migration(struct page *page)
699 struct page_cgroup *pc;
701 if (mem_cgroup_subsys.disabled)
704 lock_page_cgroup(page);
705 pc = page_get_page_cgroup(page);
708 unlock_page_cgroup(page);
712 void mem_cgroup_end_migration(struct page *page)
714 mem_cgroup_uncharge_page(page);
718 * We know both *page* and *newpage* are now not-on-LRU and PG_locked.
719 * And no race with uncharge() routines because page_cgroup for *page*
720 * has extra one reference by mem_cgroup_prepare_migration.
722 void mem_cgroup_page_migration(struct page *page, struct page *newpage)
724 struct page_cgroup *pc;
725 struct mem_cgroup_per_zone *mz;
728 lock_page_cgroup(page);
729 pc = page_get_page_cgroup(page);
731 unlock_page_cgroup(page);
735 mz = page_cgroup_zoneinfo(pc);
736 spin_lock_irqsave(&mz->lru_lock, flags);
737 __mem_cgroup_remove_list(pc);
738 spin_unlock_irqrestore(&mz->lru_lock, flags);
740 page_assign_page_cgroup(page, NULL);
741 unlock_page_cgroup(page);
744 lock_page_cgroup(newpage);
745 page_assign_page_cgroup(newpage, pc);
747 mz = page_cgroup_zoneinfo(pc);
748 spin_lock_irqsave(&mz->lru_lock, flags);
749 __mem_cgroup_add_list(pc);
750 spin_unlock_irqrestore(&mz->lru_lock, flags);
752 unlock_page_cgroup(newpage);
756 * This routine traverse page_cgroup in given list and drop them all.
757 * This routine ignores page_cgroup->ref_cnt.
758 * *And* this routine doesn't reclaim page itself, just removes page_cgroup.
760 #define FORCE_UNCHARGE_BATCH (128)
761 static void mem_cgroup_force_empty_list(struct mem_cgroup *mem,
762 struct mem_cgroup_per_zone *mz,
765 struct page_cgroup *pc;
767 int count = FORCE_UNCHARGE_BATCH;
769 struct list_head *list;
772 list = &mz->active_list;
774 list = &mz->inactive_list;
776 spin_lock_irqsave(&mz->lru_lock, flags);
777 while (!list_empty(list)) {
778 pc = list_entry(list->prev, struct page_cgroup, lru);
781 spin_unlock_irqrestore(&mz->lru_lock, flags);
782 mem_cgroup_uncharge_page(page);
785 count = FORCE_UNCHARGE_BATCH;
788 spin_lock_irqsave(&mz->lru_lock, flags);
790 spin_unlock_irqrestore(&mz->lru_lock, flags);
794 * make mem_cgroup's charge to be 0 if there is no task.
795 * This enables deleting this mem_cgroup.
797 static int mem_cgroup_force_empty(struct mem_cgroup *mem)
802 if (mem_cgroup_subsys.disabled)
807 * page reclaim code (kswapd etc..) will move pages between
808 * active_list <-> inactive_list while we don't take a lock.
809 * So, we have to do loop here until all lists are empty.
811 while (mem->res.usage > 0) {
812 if (atomic_read(&mem->css.cgroup->count) > 0)
814 for_each_node_state(node, N_POSSIBLE)
815 for (zid = 0; zid < MAX_NR_ZONES; zid++) {
816 struct mem_cgroup_per_zone *mz;
817 mz = mem_cgroup_zoneinfo(mem, node, zid);
818 /* drop all page_cgroup in active_list */
819 mem_cgroup_force_empty_list(mem, mz, 1);
820 /* drop all page_cgroup in inactive_list */
821 mem_cgroup_force_empty_list(mem, mz, 0);
830 static int mem_cgroup_write_strategy(char *buf, unsigned long long *tmp)
832 *tmp = memparse(buf, &buf);
837 * Round up the value to the closest page size
839 *tmp = ((*tmp + PAGE_SIZE - 1) >> PAGE_SHIFT) << PAGE_SHIFT;
843 static u64 mem_cgroup_read(struct cgroup *cont, struct cftype *cft)
845 return res_counter_read_u64(&mem_cgroup_from_cont(cont)->res,
849 static ssize_t mem_cgroup_write(struct cgroup *cont, struct cftype *cft,
850 struct file *file, const char __user *userbuf,
851 size_t nbytes, loff_t *ppos)
853 return res_counter_write(&mem_cgroup_from_cont(cont)->res,
854 cft->private, userbuf, nbytes, ppos,
855 mem_cgroup_write_strategy);
858 static ssize_t mem_cgroup_max_reset(struct cgroup *cont, struct cftype *cft,
859 struct file *file, const char __user *userbuf,
860 size_t nbytes, loff_t *ppos)
862 struct mem_cgroup *mem;
864 mem = mem_cgroup_from_cont(cont);
865 res_counter_reset_max(&mem->res);
869 static ssize_t mem_force_empty_write(struct cgroup *cont,
870 struct cftype *cft, struct file *file,
871 const char __user *userbuf,
872 size_t nbytes, loff_t *ppos)
874 struct mem_cgroup *mem = mem_cgroup_from_cont(cont);
875 int ret = mem_cgroup_force_empty(mem);
881 static const struct mem_cgroup_stat_desc {
884 } mem_cgroup_stat_desc[] = {
885 [MEM_CGROUP_STAT_CACHE] = { "cache", PAGE_SIZE, },
886 [MEM_CGROUP_STAT_RSS] = { "rss", PAGE_SIZE, },
889 static int mem_control_stat_show(struct cgroup *cont, struct cftype *cft,
890 struct cgroup_map_cb *cb)
892 struct mem_cgroup *mem_cont = mem_cgroup_from_cont(cont);
893 struct mem_cgroup_stat *stat = &mem_cont->stat;
896 for (i = 0; i < ARRAY_SIZE(stat->cpustat[0].count); i++) {
899 val = mem_cgroup_read_stat(stat, i);
900 val *= mem_cgroup_stat_desc[i].unit;
901 cb->fill(cb, mem_cgroup_stat_desc[i].msg, val);
903 /* showing # of active pages */
905 unsigned long active, inactive;
907 inactive = mem_cgroup_get_all_zonestat(mem_cont,
908 MEM_CGROUP_ZSTAT_INACTIVE);
909 active = mem_cgroup_get_all_zonestat(mem_cont,
910 MEM_CGROUP_ZSTAT_ACTIVE);
911 cb->fill(cb, "active", (active) * PAGE_SIZE);
912 cb->fill(cb, "inactive", (inactive) * PAGE_SIZE);
917 static struct cftype mem_cgroup_files[] = {
919 .name = "usage_in_bytes",
920 .private = RES_USAGE,
921 .read_u64 = mem_cgroup_read,
924 .name = "max_usage_in_bytes",
925 .private = RES_MAX_USAGE,
926 .write = mem_cgroup_max_reset,
927 .read_u64 = mem_cgroup_read,
930 .name = "limit_in_bytes",
931 .private = RES_LIMIT,
932 .write = mem_cgroup_write,
933 .read_u64 = mem_cgroup_read,
937 .private = RES_FAILCNT,
938 .read_u64 = mem_cgroup_read,
941 .name = "force_empty",
942 .write = mem_force_empty_write,
946 .read_map = mem_control_stat_show,
950 static int alloc_mem_cgroup_per_zone_info(struct mem_cgroup *mem, int node)
952 struct mem_cgroup_per_node *pn;
953 struct mem_cgroup_per_zone *mz;
954 int zone, tmp = node;
956 * This routine is called against possible nodes.
957 * But it's BUG to call kmalloc() against offline node.
959 * TODO: this routine can waste much memory for nodes which will
960 * never be onlined. It's better to use memory hotplug callback
963 if (!node_state(node, N_NORMAL_MEMORY))
965 pn = kmalloc_node(sizeof(*pn), GFP_KERNEL, tmp);
969 mem->info.nodeinfo[node] = pn;
970 memset(pn, 0, sizeof(*pn));
972 for (zone = 0; zone < MAX_NR_ZONES; zone++) {
973 mz = &pn->zoneinfo[zone];
974 INIT_LIST_HEAD(&mz->active_list);
975 INIT_LIST_HEAD(&mz->inactive_list);
976 spin_lock_init(&mz->lru_lock);
981 static void free_mem_cgroup_per_zone_info(struct mem_cgroup *mem, int node)
983 kfree(mem->info.nodeinfo[node]);
986 static struct cgroup_subsys_state *
987 mem_cgroup_create(struct cgroup_subsys *ss, struct cgroup *cont)
989 struct mem_cgroup *mem;
992 if (unlikely((cont->parent) == NULL))
993 mem = &init_mem_cgroup;
995 mem = kzalloc(sizeof(struct mem_cgroup), GFP_KERNEL);
998 return ERR_PTR(-ENOMEM);
1000 res_counter_init(&mem->res);
1002 memset(&mem->info, 0, sizeof(mem->info));
1004 for_each_node_state(node, N_POSSIBLE)
1005 if (alloc_mem_cgroup_per_zone_info(mem, node))
1010 for_each_node_state(node, N_POSSIBLE)
1011 free_mem_cgroup_per_zone_info(mem, node);
1012 if (cont->parent != NULL)
1014 return ERR_PTR(-ENOMEM);
1017 static void mem_cgroup_pre_destroy(struct cgroup_subsys *ss,
1018 struct cgroup *cont)
1020 struct mem_cgroup *mem = mem_cgroup_from_cont(cont);
1021 mem_cgroup_force_empty(mem);
1024 static void mem_cgroup_destroy(struct cgroup_subsys *ss,
1025 struct cgroup *cont)
1028 struct mem_cgroup *mem = mem_cgroup_from_cont(cont);
1030 for_each_node_state(node, N_POSSIBLE)
1031 free_mem_cgroup_per_zone_info(mem, node);
1033 kfree(mem_cgroup_from_cont(cont));
1036 static int mem_cgroup_populate(struct cgroup_subsys *ss,
1037 struct cgroup *cont)
1039 if (mem_cgroup_subsys.disabled)
1041 return cgroup_add_files(cont, ss, mem_cgroup_files,
1042 ARRAY_SIZE(mem_cgroup_files));
1045 static void mem_cgroup_move_task(struct cgroup_subsys *ss,
1046 struct cgroup *cont,
1047 struct cgroup *old_cont,
1048 struct task_struct *p)
1050 struct mm_struct *mm;
1051 struct mem_cgroup *mem, *old_mem;
1053 if (mem_cgroup_subsys.disabled)
1056 mm = get_task_mm(p);
1060 mem = mem_cgroup_from_cont(cont);
1061 old_mem = mem_cgroup_from_cont(old_cont);
1067 * Only thread group leaders are allowed to migrate, the mm_struct is
1068 * in effect owned by the leader
1070 if (!thread_group_leader(p))
1077 struct cgroup_subsys mem_cgroup_subsys = {
1079 .subsys_id = mem_cgroup_subsys_id,
1080 .create = mem_cgroup_create,
1081 .pre_destroy = mem_cgroup_pre_destroy,
1082 .destroy = mem_cgroup_destroy,
1083 .populate = mem_cgroup_populate,
1084 .attach = mem_cgroup_move_task,