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 static 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 void mm_init_cgroup(struct mm_struct *mm, struct task_struct *p)
247 struct mem_cgroup *mem;
249 mem = mem_cgroup_from_task(p);
251 mm->mem_cgroup = mem;
254 void mm_free_cgroup(struct mm_struct *mm)
256 css_put(&mm->mem_cgroup->css);
259 static inline int page_cgroup_locked(struct page *page)
261 return bit_spin_is_locked(PAGE_CGROUP_LOCK_BIT, &page->page_cgroup);
264 static void page_assign_page_cgroup(struct page *page, struct page_cgroup *pc)
266 VM_BUG_ON(!page_cgroup_locked(page));
267 page->page_cgroup = ((unsigned long)pc | PAGE_CGROUP_LOCK);
270 struct page_cgroup *page_get_page_cgroup(struct page *page)
272 return (struct page_cgroup *) (page->page_cgroup & ~PAGE_CGROUP_LOCK);
275 static void lock_page_cgroup(struct page *page)
277 bit_spin_lock(PAGE_CGROUP_LOCK_BIT, &page->page_cgroup);
280 static int try_lock_page_cgroup(struct page *page)
282 return bit_spin_trylock(PAGE_CGROUP_LOCK_BIT, &page->page_cgroup);
285 static void unlock_page_cgroup(struct page *page)
287 bit_spin_unlock(PAGE_CGROUP_LOCK_BIT, &page->page_cgroup);
290 static void __mem_cgroup_remove_list(struct page_cgroup *pc)
292 int from = 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_ACTIVE) -= 1;
298 MEM_CGROUP_ZSTAT(mz, MEM_CGROUP_ZSTAT_INACTIVE) -= 1;
300 mem_cgroup_charge_statistics(pc->mem_cgroup, pc->flags, false);
301 list_del_init(&pc->lru);
304 static void __mem_cgroup_add_list(struct page_cgroup *pc)
306 int to = pc->flags & PAGE_CGROUP_FLAG_ACTIVE;
307 struct mem_cgroup_per_zone *mz = page_cgroup_zoneinfo(pc);
310 MEM_CGROUP_ZSTAT(mz, MEM_CGROUP_ZSTAT_INACTIVE) += 1;
311 list_add(&pc->lru, &mz->inactive_list);
313 MEM_CGROUP_ZSTAT(mz, MEM_CGROUP_ZSTAT_ACTIVE) += 1;
314 list_add(&pc->lru, &mz->active_list);
316 mem_cgroup_charge_statistics(pc->mem_cgroup, pc->flags, true);
319 static void __mem_cgroup_move_lists(struct page_cgroup *pc, bool active)
321 int from = pc->flags & PAGE_CGROUP_FLAG_ACTIVE;
322 struct mem_cgroup_per_zone *mz = page_cgroup_zoneinfo(pc);
325 MEM_CGROUP_ZSTAT(mz, MEM_CGROUP_ZSTAT_ACTIVE) -= 1;
327 MEM_CGROUP_ZSTAT(mz, MEM_CGROUP_ZSTAT_INACTIVE) -= 1;
330 MEM_CGROUP_ZSTAT(mz, MEM_CGROUP_ZSTAT_ACTIVE) += 1;
331 pc->flags |= PAGE_CGROUP_FLAG_ACTIVE;
332 list_move(&pc->lru, &mz->active_list);
334 MEM_CGROUP_ZSTAT(mz, MEM_CGROUP_ZSTAT_INACTIVE) += 1;
335 pc->flags &= ~PAGE_CGROUP_FLAG_ACTIVE;
336 list_move(&pc->lru, &mz->inactive_list);
340 int task_in_mem_cgroup(struct task_struct *task, const struct mem_cgroup *mem)
345 ret = task->mm && mm_match_cgroup(task->mm, mem);
351 * This routine assumes that the appropriate zone's lru lock is already held
353 void mem_cgroup_move_lists(struct page *page, bool active)
355 struct page_cgroup *pc;
356 struct mem_cgroup_per_zone *mz;
360 * We cannot lock_page_cgroup while holding zone's lru_lock,
361 * because other holders of lock_page_cgroup can be interrupted
362 * with an attempt to rotate_reclaimable_page. But we cannot
363 * safely get to page_cgroup without it, so just try_lock it:
364 * mem_cgroup_isolate_pages allows for page left on wrong list.
366 if (!try_lock_page_cgroup(page))
369 pc = page_get_page_cgroup(page);
371 mz = page_cgroup_zoneinfo(pc);
372 spin_lock_irqsave(&mz->lru_lock, flags);
373 __mem_cgroup_move_lists(pc, active);
374 spin_unlock_irqrestore(&mz->lru_lock, flags);
376 unlock_page_cgroup(page);
380 * Calculate mapped_ratio under memory controller. This will be used in
381 * vmscan.c for deteremining we have to reclaim mapped pages.
383 int mem_cgroup_calc_mapped_ratio(struct mem_cgroup *mem)
388 * usage is recorded in bytes. But, here, we assume the number of
389 * physical pages can be represented by "long" on any arch.
391 total = (long) (mem->res.usage >> PAGE_SHIFT) + 1L;
392 rss = (long)mem_cgroup_read_stat(&mem->stat, MEM_CGROUP_STAT_RSS);
393 return (int)((rss * 100L) / total);
397 * This function is called from vmscan.c. In page reclaiming loop. balance
398 * between active and inactive list is calculated. For memory controller
399 * page reclaiming, we should use using mem_cgroup's imbalance rather than
400 * zone's global lru imbalance.
402 long mem_cgroup_reclaim_imbalance(struct mem_cgroup *mem)
404 unsigned long active, inactive;
405 /* active and inactive are the number of pages. 'long' is ok.*/
406 active = mem_cgroup_get_all_zonestat(mem, MEM_CGROUP_ZSTAT_ACTIVE);
407 inactive = mem_cgroup_get_all_zonestat(mem, MEM_CGROUP_ZSTAT_INACTIVE);
408 return (long) (active / (inactive + 1));
412 * prev_priority control...this will be used in memory reclaim path.
414 int mem_cgroup_get_reclaim_priority(struct mem_cgroup *mem)
416 return mem->prev_priority;
419 void mem_cgroup_note_reclaim_priority(struct mem_cgroup *mem, int priority)
421 if (priority < mem->prev_priority)
422 mem->prev_priority = priority;
425 void mem_cgroup_record_reclaim_priority(struct mem_cgroup *mem, int priority)
427 mem->prev_priority = priority;
431 * Calculate # of pages to be scanned in this priority/zone.
434 * priority starts from "DEF_PRIORITY" and decremented in each loop.
435 * (see include/linux/mmzone.h)
438 long mem_cgroup_calc_reclaim_active(struct mem_cgroup *mem,
439 struct zone *zone, int priority)
442 int nid = zone->zone_pgdat->node_id;
443 int zid = zone_idx(zone);
444 struct mem_cgroup_per_zone *mz = mem_cgroup_zoneinfo(mem, nid, zid);
446 nr_active = MEM_CGROUP_ZSTAT(mz, MEM_CGROUP_ZSTAT_ACTIVE);
447 return (nr_active >> priority);
450 long mem_cgroup_calc_reclaim_inactive(struct mem_cgroup *mem,
451 struct zone *zone, int priority)
454 int nid = zone->zone_pgdat->node_id;
455 int zid = zone_idx(zone);
456 struct mem_cgroup_per_zone *mz = mem_cgroup_zoneinfo(mem, nid, zid);
458 nr_inactive = MEM_CGROUP_ZSTAT(mz, MEM_CGROUP_ZSTAT_INACTIVE);
459 return (nr_inactive >> priority);
462 unsigned long mem_cgroup_isolate_pages(unsigned long nr_to_scan,
463 struct list_head *dst,
464 unsigned long *scanned, int order,
465 int mode, struct zone *z,
466 struct mem_cgroup *mem_cont,
469 unsigned long nr_taken = 0;
473 struct list_head *src;
474 struct page_cgroup *pc, *tmp;
475 int nid = z->zone_pgdat->node_id;
476 int zid = zone_idx(z);
477 struct mem_cgroup_per_zone *mz;
479 mz = mem_cgroup_zoneinfo(mem_cont, nid, zid);
481 src = &mz->active_list;
483 src = &mz->inactive_list;
486 spin_lock(&mz->lru_lock);
488 list_for_each_entry_safe_reverse(pc, tmp, src, lru) {
489 if (scan >= nr_to_scan)
493 if (unlikely(!PageLRU(page)))
496 if (PageActive(page) && !active) {
497 __mem_cgroup_move_lists(pc, true);
500 if (!PageActive(page) && active) {
501 __mem_cgroup_move_lists(pc, false);
506 list_move(&pc->lru, &pc_list);
508 if (__isolate_lru_page(page, mode) == 0) {
509 list_move(&page->lru, dst);
514 list_splice(&pc_list, src);
515 spin_unlock(&mz->lru_lock);
522 * Charge the memory controller for page usage.
524 * 0 if the charge was successful
525 * < 0 if the cgroup is over its limit
527 static int mem_cgroup_charge_common(struct page *page, struct mm_struct *mm,
528 gfp_t gfp_mask, enum charge_type ctype)
530 struct mem_cgroup *mem;
531 struct page_cgroup *pc;
533 unsigned long nr_retries = MEM_CGROUP_RECLAIM_RETRIES;
534 struct mem_cgroup_per_zone *mz;
537 * Should page_cgroup's go to their own slab?
538 * One could optimize the performance of the charging routine
539 * by saving a bit in the page_flags and using it as a lock
540 * to see if the cgroup page already has a page_cgroup associated
544 lock_page_cgroup(page);
545 pc = page_get_page_cgroup(page);
547 * The page_cgroup exists and
548 * the page has already been accounted.
551 VM_BUG_ON(pc->page != page);
552 VM_BUG_ON(pc->ref_cnt <= 0);
555 unlock_page_cgroup(page);
558 unlock_page_cgroup(page);
560 pc = kzalloc(sizeof(struct page_cgroup), gfp_mask);
565 * We always charge the cgroup the mm_struct belongs to.
566 * The mm_struct's mem_cgroup changes on task migration if the
567 * thread group leader migrates. It's possible that mm is not
568 * set, if so charge the init_mm (happens for pagecache usage).
574 mem = rcu_dereference(mm->mem_cgroup);
576 * For every charge from the cgroup, increment reference count
581 while (res_counter_charge(&mem->res, PAGE_SIZE)) {
582 if (!(gfp_mask & __GFP_WAIT))
585 if (try_to_free_mem_cgroup_pages(mem, gfp_mask))
589 * try_to_free_mem_cgroup_pages() might not give us a full
590 * picture of reclaim. Some pages are reclaimed and might be
591 * moved to swap cache or just unmapped from the cgroup.
592 * Check the limit again to see if the reclaim reduced the
593 * current usage of the cgroup before giving up
595 if (res_counter_check_under_limit(&mem->res))
599 mem_cgroup_out_of_memory(mem, gfp_mask);
602 congestion_wait(WRITE, HZ/10);
606 pc->mem_cgroup = mem;
608 pc->flags = PAGE_CGROUP_FLAG_ACTIVE;
609 if (ctype == MEM_CGROUP_CHARGE_TYPE_CACHE)
610 pc->flags |= PAGE_CGROUP_FLAG_CACHE;
612 lock_page_cgroup(page);
613 if (page_get_page_cgroup(page)) {
614 unlock_page_cgroup(page);
616 * Another charge has been added to this page already.
617 * We take lock_page_cgroup(page) again and read
618 * page->cgroup, increment refcnt.... just retry is OK.
620 res_counter_uncharge(&mem->res, PAGE_SIZE);
625 page_assign_page_cgroup(page, pc);
626 unlock_page_cgroup(page);
628 mz = page_cgroup_zoneinfo(pc);
629 spin_lock_irqsave(&mz->lru_lock, flags);
630 __mem_cgroup_add_list(pc);
631 spin_unlock_irqrestore(&mz->lru_lock, flags);
642 int mem_cgroup_charge(struct page *page, struct mm_struct *mm, gfp_t gfp_mask)
644 return mem_cgroup_charge_common(page, mm, gfp_mask,
645 MEM_CGROUP_CHARGE_TYPE_MAPPED);
648 int mem_cgroup_cache_charge(struct page *page, struct mm_struct *mm,
653 return mem_cgroup_charge_common(page, mm, gfp_mask,
654 MEM_CGROUP_CHARGE_TYPE_CACHE);
658 * Uncharging is always a welcome operation, we never complain, simply
661 void mem_cgroup_uncharge_page(struct page *page)
663 struct page_cgroup *pc;
664 struct mem_cgroup *mem;
665 struct mem_cgroup_per_zone *mz;
669 * Check if our page_cgroup is valid
671 lock_page_cgroup(page);
672 pc = page_get_page_cgroup(page);
676 VM_BUG_ON(pc->page != page);
677 VM_BUG_ON(pc->ref_cnt <= 0);
679 if (--(pc->ref_cnt) == 0) {
680 page_assign_page_cgroup(page, NULL);
681 unlock_page_cgroup(page);
683 mz = page_cgroup_zoneinfo(pc);
684 spin_lock_irqsave(&mz->lru_lock, flags);
685 __mem_cgroup_remove_list(pc);
686 spin_unlock_irqrestore(&mz->lru_lock, flags);
688 mem = pc->mem_cgroup;
689 res_counter_uncharge(&mem->res, PAGE_SIZE);
697 unlock_page_cgroup(page);
701 * Returns non-zero if a page (under migration) has valid page_cgroup member.
702 * Refcnt of page_cgroup is incremented.
704 int mem_cgroup_prepare_migration(struct page *page)
706 struct page_cgroup *pc;
708 lock_page_cgroup(page);
709 pc = page_get_page_cgroup(page);
712 unlock_page_cgroup(page);
716 void mem_cgroup_end_migration(struct page *page)
718 mem_cgroup_uncharge_page(page);
722 * We know both *page* and *newpage* are now not-on-LRU and PG_locked.
723 * And no race with uncharge() routines because page_cgroup for *page*
724 * has extra one reference by mem_cgroup_prepare_migration.
726 void mem_cgroup_page_migration(struct page *page, struct page *newpage)
728 struct page_cgroup *pc;
729 struct mem_cgroup_per_zone *mz;
732 lock_page_cgroup(page);
733 pc = page_get_page_cgroup(page);
735 unlock_page_cgroup(page);
739 page_assign_page_cgroup(page, NULL);
740 unlock_page_cgroup(page);
742 mz = page_cgroup_zoneinfo(pc);
743 spin_lock_irqsave(&mz->lru_lock, flags);
744 __mem_cgroup_remove_list(pc);
745 spin_unlock_irqrestore(&mz->lru_lock, flags);
748 lock_page_cgroup(newpage);
749 page_assign_page_cgroup(newpage, pc);
750 unlock_page_cgroup(newpage);
752 mz = page_cgroup_zoneinfo(pc);
753 spin_lock_irqsave(&mz->lru_lock, flags);
754 __mem_cgroup_add_list(pc);
755 spin_unlock_irqrestore(&mz->lru_lock, flags);
759 * This routine traverse page_cgroup in given list and drop them all.
760 * This routine ignores page_cgroup->ref_cnt.
761 * *And* this routine doesn't reclaim page itself, just removes page_cgroup.
763 #define FORCE_UNCHARGE_BATCH (128)
764 static void mem_cgroup_force_empty_list(struct mem_cgroup *mem,
765 struct mem_cgroup_per_zone *mz,
768 struct page_cgroup *pc;
770 int count = FORCE_UNCHARGE_BATCH;
772 struct list_head *list;
775 list = &mz->active_list;
777 list = &mz->inactive_list;
779 spin_lock_irqsave(&mz->lru_lock, flags);
780 while (!list_empty(list)) {
781 pc = list_entry(list->prev, struct page_cgroup, lru);
784 spin_unlock_irqrestore(&mz->lru_lock, flags);
785 mem_cgroup_uncharge_page(page);
788 count = FORCE_UNCHARGE_BATCH;
791 spin_lock_irqsave(&mz->lru_lock, flags);
793 spin_unlock_irqrestore(&mz->lru_lock, flags);
797 * make mem_cgroup's charge to be 0 if there is no task.
798 * This enables deleting this mem_cgroup.
800 static int mem_cgroup_force_empty(struct mem_cgroup *mem)
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 ssize_t mem_cgroup_read(struct cgroup *cont,
844 struct cftype *cft, struct file *file,
845 char __user *userbuf, size_t nbytes, loff_t *ppos)
847 return res_counter_read(&mem_cgroup_from_cont(cont)->res,
848 cft->private, userbuf, nbytes, ppos,
852 static ssize_t mem_cgroup_write(struct cgroup *cont, struct cftype *cft,
853 struct file *file, const char __user *userbuf,
854 size_t nbytes, loff_t *ppos)
856 return res_counter_write(&mem_cgroup_from_cont(cont)->res,
857 cft->private, userbuf, nbytes, ppos,
858 mem_cgroup_write_strategy);
861 static ssize_t mem_force_empty_write(struct cgroup *cont,
862 struct cftype *cft, struct file *file,
863 const char __user *userbuf,
864 size_t nbytes, loff_t *ppos)
866 struct mem_cgroup *mem = mem_cgroup_from_cont(cont);
867 int ret = mem_cgroup_force_empty(mem);
874 * Note: This should be removed if cgroup supports write-only file.
876 static ssize_t mem_force_empty_read(struct cgroup *cont,
878 struct file *file, char __user *userbuf,
879 size_t nbytes, loff_t *ppos)
884 static const struct mem_cgroup_stat_desc {
887 } mem_cgroup_stat_desc[] = {
888 [MEM_CGROUP_STAT_CACHE] = { "cache", PAGE_SIZE, },
889 [MEM_CGROUP_STAT_RSS] = { "rss", PAGE_SIZE, },
892 static int mem_control_stat_show(struct seq_file *m, void *arg)
894 struct cgroup *cont = m->private;
895 struct mem_cgroup *mem_cont = mem_cgroup_from_cont(cont);
896 struct mem_cgroup_stat *stat = &mem_cont->stat;
899 for (i = 0; i < ARRAY_SIZE(stat->cpustat[0].count); i++) {
902 val = mem_cgroup_read_stat(stat, i);
903 val *= mem_cgroup_stat_desc[i].unit;
904 seq_printf(m, "%s %lld\n", mem_cgroup_stat_desc[i].msg,
907 /* showing # of active pages */
909 unsigned long active, inactive;
911 inactive = mem_cgroup_get_all_zonestat(mem_cont,
912 MEM_CGROUP_ZSTAT_INACTIVE);
913 active = mem_cgroup_get_all_zonestat(mem_cont,
914 MEM_CGROUP_ZSTAT_ACTIVE);
915 seq_printf(m, "active %ld\n", (active) * PAGE_SIZE);
916 seq_printf(m, "inactive %ld\n", (inactive) * PAGE_SIZE);
921 static const struct file_operations mem_control_stat_file_operations = {
924 .release = single_release,
927 static int mem_control_stat_open(struct inode *unused, struct file *file)
930 struct cgroup *cont = file->f_dentry->d_parent->d_fsdata;
932 file->f_op = &mem_control_stat_file_operations;
933 return single_open(file, mem_control_stat_show, cont);
936 static struct cftype mem_cgroup_files[] = {
938 .name = "usage_in_bytes",
939 .private = RES_USAGE,
940 .read = mem_cgroup_read,
943 .name = "limit_in_bytes",
944 .private = RES_LIMIT,
945 .write = mem_cgroup_write,
946 .read = mem_cgroup_read,
950 .private = RES_FAILCNT,
951 .read = mem_cgroup_read,
954 .name = "force_empty",
955 .write = mem_force_empty_write,
956 .read = mem_force_empty_read,
960 .open = mem_control_stat_open,
964 static int alloc_mem_cgroup_per_zone_info(struct mem_cgroup *mem, int node)
966 struct mem_cgroup_per_node *pn;
967 struct mem_cgroup_per_zone *mz;
970 * This routine is called against possible nodes.
971 * But it's BUG to call kmalloc() against offline node.
973 * TODO: this routine can waste much memory for nodes which will
974 * never be onlined. It's better to use memory hotplug callback
977 if (node_state(node, N_HIGH_MEMORY))
978 pn = kmalloc_node(sizeof(*pn), GFP_KERNEL, node);
980 pn = kmalloc(sizeof(*pn), GFP_KERNEL);
984 mem->info.nodeinfo[node] = pn;
985 memset(pn, 0, sizeof(*pn));
987 for (zone = 0; zone < MAX_NR_ZONES; zone++) {
988 mz = &pn->zoneinfo[zone];
989 INIT_LIST_HEAD(&mz->active_list);
990 INIT_LIST_HEAD(&mz->inactive_list);
991 spin_lock_init(&mz->lru_lock);
996 static void free_mem_cgroup_per_zone_info(struct mem_cgroup *mem, int node)
998 kfree(mem->info.nodeinfo[node]);
1001 static struct cgroup_subsys_state *
1002 mem_cgroup_create(struct cgroup_subsys *ss, struct cgroup *cont)
1004 struct mem_cgroup *mem;
1007 if (unlikely((cont->parent) == NULL)) {
1008 mem = &init_mem_cgroup;
1009 init_mm.mem_cgroup = mem;
1011 mem = kzalloc(sizeof(struct mem_cgroup), GFP_KERNEL);
1014 return ERR_PTR(-ENOMEM);
1016 res_counter_init(&mem->res);
1018 memset(&mem->info, 0, sizeof(mem->info));
1020 for_each_node_state(node, N_POSSIBLE)
1021 if (alloc_mem_cgroup_per_zone_info(mem, node))
1026 for_each_node_state(node, N_POSSIBLE)
1027 free_mem_cgroup_per_zone_info(mem, node);
1028 if (cont->parent != NULL)
1030 return ERR_PTR(-ENOMEM);
1033 static void mem_cgroup_pre_destroy(struct cgroup_subsys *ss,
1034 struct cgroup *cont)
1036 struct mem_cgroup *mem = mem_cgroup_from_cont(cont);
1037 mem_cgroup_force_empty(mem);
1040 static void mem_cgroup_destroy(struct cgroup_subsys *ss,
1041 struct cgroup *cont)
1044 struct mem_cgroup *mem = mem_cgroup_from_cont(cont);
1046 for_each_node_state(node, N_POSSIBLE)
1047 free_mem_cgroup_per_zone_info(mem, node);
1049 kfree(mem_cgroup_from_cont(cont));
1052 static int mem_cgroup_populate(struct cgroup_subsys *ss,
1053 struct cgroup *cont)
1055 return cgroup_add_files(cont, ss, mem_cgroup_files,
1056 ARRAY_SIZE(mem_cgroup_files));
1059 static void mem_cgroup_move_task(struct cgroup_subsys *ss,
1060 struct cgroup *cont,
1061 struct cgroup *old_cont,
1062 struct task_struct *p)
1064 struct mm_struct *mm;
1065 struct mem_cgroup *mem, *old_mem;
1067 mm = get_task_mm(p);
1071 mem = mem_cgroup_from_cont(cont);
1072 old_mem = mem_cgroup_from_cont(old_cont);
1078 * Only thread group leaders are allowed to migrate, the mm_struct is
1079 * in effect owned by the leader
1081 if (p->tgid != p->pid)
1085 rcu_assign_pointer(mm->mem_cgroup, mem);
1086 css_put(&old_mem->css);
1092 struct cgroup_subsys mem_cgroup_subsys = {
1094 .subsys_id = mem_cgroup_subsys_id,
1095 .create = mem_cgroup_create,
1096 .pre_destroy = mem_cgroup_pre_destroy,
1097 .destroy = mem_cgroup_destroy,
1098 .populate = mem_cgroup_populate,
1099 .attach = mem_cgroup_move_task,