ocfs2: Make transaction extend more efficient.
[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / mm / memcontrol.c
blobe2fa20dadf408e2d38e6b5a4a61ed4fb9febd3a1
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>
23 #include <linux/mm.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/limits.h>
31 #include <linux/mutex.h>
32 #include <linux/slab.h>
33 #include <linux/swap.h>
34 #include <linux/spinlock.h>
35 #include <linux/fs.h>
36 #include <linux/seq_file.h>
37 #include <linux/vmalloc.h>
38 #include <linux/mm_inline.h>
39 #include <linux/page_cgroup.h>
40 #include "internal.h"
42 #include <asm/uaccess.h>
44 struct cgroup_subsys mem_cgroup_subsys __read_mostly;
45 #define MEM_CGROUP_RECLAIM_RETRIES 5
47 #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP
48 /* Turned on only when memory cgroup is enabled && really_do_swap_account = 1 */
49 int do_swap_account __read_mostly;
50 static int really_do_swap_account __initdata = 1; /* for remember boot option*/
51 #else
52 #define do_swap_account (0)
53 #endif
55 static DEFINE_MUTEX(memcg_tasklist); /* can be hold under cgroup_mutex */
58 * Statistics for memory cgroup.
60 enum mem_cgroup_stat_index {
62 * For MEM_CONTAINER_TYPE_ALL, usage = pagecache + rss.
64 MEM_CGROUP_STAT_CACHE, /* # of pages charged as cache */
65 MEM_CGROUP_STAT_RSS, /* # of pages charged as anon rss */
66 MEM_CGROUP_STAT_MAPPED_FILE, /* # of pages charged as file rss */
67 MEM_CGROUP_STAT_PGPGIN_COUNT, /* # of pages paged in */
68 MEM_CGROUP_STAT_PGPGOUT_COUNT, /* # of pages paged out */
70 MEM_CGROUP_STAT_NSTATS,
73 struct mem_cgroup_stat_cpu {
74 s64 count[MEM_CGROUP_STAT_NSTATS];
75 } ____cacheline_aligned_in_smp;
77 struct mem_cgroup_stat {
78 struct mem_cgroup_stat_cpu cpustat[0];
82 * For accounting under irq disable, no need for increment preempt count.
84 static inline void __mem_cgroup_stat_add_safe(struct mem_cgroup_stat_cpu *stat,
85 enum mem_cgroup_stat_index idx, int val)
87 stat->count[idx] += val;
90 static s64 mem_cgroup_read_stat(struct mem_cgroup_stat *stat,
91 enum mem_cgroup_stat_index idx)
93 int cpu;
94 s64 ret = 0;
95 for_each_possible_cpu(cpu)
96 ret += stat->cpustat[cpu].count[idx];
97 return ret;
100 static s64 mem_cgroup_local_usage(struct mem_cgroup_stat *stat)
102 s64 ret;
104 ret = mem_cgroup_read_stat(stat, MEM_CGROUP_STAT_CACHE);
105 ret += mem_cgroup_read_stat(stat, MEM_CGROUP_STAT_RSS);
106 return ret;
110 * per-zone information in memory controller.
112 struct mem_cgroup_per_zone {
114 * spin_lock to protect the per cgroup LRU
116 struct list_head lists[NR_LRU_LISTS];
117 unsigned long count[NR_LRU_LISTS];
119 struct zone_reclaim_stat reclaim_stat;
121 /* Macro for accessing counter */
122 #define MEM_CGROUP_ZSTAT(mz, idx) ((mz)->count[(idx)])
124 struct mem_cgroup_per_node {
125 struct mem_cgroup_per_zone zoneinfo[MAX_NR_ZONES];
128 struct mem_cgroup_lru_info {
129 struct mem_cgroup_per_node *nodeinfo[MAX_NUMNODES];
133 * The memory controller data structure. The memory controller controls both
134 * page cache and RSS per cgroup. We would eventually like to provide
135 * statistics based on the statistics developed by Rik Van Riel for clock-pro,
136 * to help the administrator determine what knobs to tune.
138 * TODO: Add a water mark for the memory controller. Reclaim will begin when
139 * we hit the water mark. May be even add a low water mark, such that
140 * no reclaim occurs from a cgroup at it's low water mark, this is
141 * a feature that will be implemented much later in the future.
143 struct mem_cgroup {
144 struct cgroup_subsys_state css;
146 * the counter to account for memory usage
148 struct res_counter res;
150 * the counter to account for mem+swap usage.
152 struct res_counter memsw;
154 * Per cgroup active and inactive list, similar to the
155 * per zone LRU lists.
157 struct mem_cgroup_lru_info info;
160 protect against reclaim related member.
162 spinlock_t reclaim_param_lock;
164 int prev_priority; /* for recording reclaim priority */
167 * While reclaiming in a hiearchy, we cache the last child we
168 * reclaimed from.
170 int last_scanned_child;
172 * Should the accounting and control be hierarchical, per subtree?
174 bool use_hierarchy;
175 unsigned long last_oom_jiffies;
176 atomic_t refcnt;
178 unsigned int swappiness;
180 /* set when res.limit == memsw.limit */
181 bool memsw_is_minimum;
184 * statistics. This must be placed at the end of memcg.
186 struct mem_cgroup_stat stat;
189 enum charge_type {
190 MEM_CGROUP_CHARGE_TYPE_CACHE = 0,
191 MEM_CGROUP_CHARGE_TYPE_MAPPED,
192 MEM_CGROUP_CHARGE_TYPE_SHMEM, /* used by page migration of shmem */
193 MEM_CGROUP_CHARGE_TYPE_FORCE, /* used by force_empty */
194 MEM_CGROUP_CHARGE_TYPE_SWAPOUT, /* for accounting swapcache */
195 MEM_CGROUP_CHARGE_TYPE_DROP, /* a page was unused swap cache */
196 NR_CHARGE_TYPE,
199 /* only for here (for easy reading.) */
200 #define PCGF_CACHE (1UL << PCG_CACHE)
201 #define PCGF_USED (1UL << PCG_USED)
202 #define PCGF_LOCK (1UL << PCG_LOCK)
203 static const unsigned long
204 pcg_default_flags[NR_CHARGE_TYPE] = {
205 PCGF_CACHE | PCGF_USED | PCGF_LOCK, /* File Cache */
206 PCGF_USED | PCGF_LOCK, /* Anon */
207 PCGF_CACHE | PCGF_USED | PCGF_LOCK, /* Shmem */
208 0, /* FORCE */
211 /* for encoding cft->private value on file */
212 #define _MEM (0)
213 #define _MEMSWAP (1)
214 #define MEMFILE_PRIVATE(x, val) (((x) << 16) | (val))
215 #define MEMFILE_TYPE(val) (((val) >> 16) & 0xffff)
216 #define MEMFILE_ATTR(val) ((val) & 0xffff)
218 static void mem_cgroup_get(struct mem_cgroup *mem);
219 static void mem_cgroup_put(struct mem_cgroup *mem);
220 static struct mem_cgroup *parent_mem_cgroup(struct mem_cgroup *mem);
222 static void mem_cgroup_charge_statistics(struct mem_cgroup *mem,
223 struct page_cgroup *pc,
224 bool charge)
226 int val = (charge)? 1 : -1;
227 struct mem_cgroup_stat *stat = &mem->stat;
228 struct mem_cgroup_stat_cpu *cpustat;
229 int cpu = get_cpu();
231 cpustat = &stat->cpustat[cpu];
232 if (PageCgroupCache(pc))
233 __mem_cgroup_stat_add_safe(cpustat, MEM_CGROUP_STAT_CACHE, val);
234 else
235 __mem_cgroup_stat_add_safe(cpustat, MEM_CGROUP_STAT_RSS, val);
237 if (charge)
238 __mem_cgroup_stat_add_safe(cpustat,
239 MEM_CGROUP_STAT_PGPGIN_COUNT, 1);
240 else
241 __mem_cgroup_stat_add_safe(cpustat,
242 MEM_CGROUP_STAT_PGPGOUT_COUNT, 1);
243 put_cpu();
246 static struct mem_cgroup_per_zone *
247 mem_cgroup_zoneinfo(struct mem_cgroup *mem, int nid, int zid)
249 return &mem->info.nodeinfo[nid]->zoneinfo[zid];
252 static struct mem_cgroup_per_zone *
253 page_cgroup_zoneinfo(struct page_cgroup *pc)
255 struct mem_cgroup *mem = pc->mem_cgroup;
256 int nid = page_cgroup_nid(pc);
257 int zid = page_cgroup_zid(pc);
259 if (!mem)
260 return NULL;
262 return mem_cgroup_zoneinfo(mem, nid, zid);
265 static unsigned long mem_cgroup_get_local_zonestat(struct mem_cgroup *mem,
266 enum lru_list idx)
268 int nid, zid;
269 struct mem_cgroup_per_zone *mz;
270 u64 total = 0;
272 for_each_online_node(nid)
273 for (zid = 0; zid < MAX_NR_ZONES; zid++) {
274 mz = mem_cgroup_zoneinfo(mem, nid, zid);
275 total += MEM_CGROUP_ZSTAT(mz, idx);
277 return total;
280 static struct mem_cgroup *mem_cgroup_from_cont(struct cgroup *cont)
282 return container_of(cgroup_subsys_state(cont,
283 mem_cgroup_subsys_id), struct mem_cgroup,
284 css);
287 struct mem_cgroup *mem_cgroup_from_task(struct task_struct *p)
290 * mm_update_next_owner() may clear mm->owner to NULL
291 * if it races with swapoff, page migration, etc.
292 * So this can be called with p == NULL.
294 if (unlikely(!p))
295 return NULL;
297 return container_of(task_subsys_state(p, mem_cgroup_subsys_id),
298 struct mem_cgroup, css);
301 static struct mem_cgroup *try_get_mem_cgroup_from_mm(struct mm_struct *mm)
303 struct mem_cgroup *mem = NULL;
305 if (!mm)
306 return NULL;
308 * Because we have no locks, mm->owner's may be being moved to other
309 * cgroup. We use css_tryget() here even if this looks
310 * pessimistic (rather than adding locks here).
312 rcu_read_lock();
313 do {
314 mem = mem_cgroup_from_task(rcu_dereference(mm->owner));
315 if (unlikely(!mem))
316 break;
317 } while (!css_tryget(&mem->css));
318 rcu_read_unlock();
319 return mem;
323 * Call callback function against all cgroup under hierarchy tree.
325 static int mem_cgroup_walk_tree(struct mem_cgroup *root, void *data,
326 int (*func)(struct mem_cgroup *, void *))
328 int found, ret, nextid;
329 struct cgroup_subsys_state *css;
330 struct mem_cgroup *mem;
332 if (!root->use_hierarchy)
333 return (*func)(root, data);
335 nextid = 1;
336 do {
337 ret = 0;
338 mem = NULL;
340 rcu_read_lock();
341 css = css_get_next(&mem_cgroup_subsys, nextid, &root->css,
342 &found);
343 if (css && css_tryget(css))
344 mem = container_of(css, struct mem_cgroup, css);
345 rcu_read_unlock();
347 if (mem) {
348 ret = (*func)(mem, data);
349 css_put(&mem->css);
351 nextid = found + 1;
352 } while (!ret && css);
354 return ret;
358 * Following LRU functions are allowed to be used without PCG_LOCK.
359 * Operations are called by routine of global LRU independently from memcg.
360 * What we have to take care of here is validness of pc->mem_cgroup.
362 * Changes to pc->mem_cgroup happens when
363 * 1. charge
364 * 2. moving account
365 * In typical case, "charge" is done before add-to-lru. Exception is SwapCache.
366 * It is added to LRU before charge.
367 * If PCG_USED bit is not set, page_cgroup is not added to this private LRU.
368 * When moving account, the page is not on LRU. It's isolated.
371 void mem_cgroup_del_lru_list(struct page *page, enum lru_list lru)
373 struct page_cgroup *pc;
374 struct mem_cgroup *mem;
375 struct mem_cgroup_per_zone *mz;
377 if (mem_cgroup_disabled())
378 return;
379 pc = lookup_page_cgroup(page);
380 /* can happen while we handle swapcache. */
381 if (list_empty(&pc->lru) || !pc->mem_cgroup)
382 return;
384 * We don't check PCG_USED bit. It's cleared when the "page" is finally
385 * removed from global LRU.
387 mz = page_cgroup_zoneinfo(pc);
388 mem = pc->mem_cgroup;
389 MEM_CGROUP_ZSTAT(mz, lru) -= 1;
390 list_del_init(&pc->lru);
391 return;
394 void mem_cgroup_del_lru(struct page *page)
396 mem_cgroup_del_lru_list(page, page_lru(page));
399 void mem_cgroup_rotate_lru_list(struct page *page, enum lru_list lru)
401 struct mem_cgroup_per_zone *mz;
402 struct page_cgroup *pc;
404 if (mem_cgroup_disabled())
405 return;
407 pc = lookup_page_cgroup(page);
409 * Used bit is set without atomic ops but after smp_wmb().
410 * For making pc->mem_cgroup visible, insert smp_rmb() here.
412 smp_rmb();
413 /* unused page is not rotated. */
414 if (!PageCgroupUsed(pc))
415 return;
416 mz = page_cgroup_zoneinfo(pc);
417 list_move(&pc->lru, &mz->lists[lru]);
420 void mem_cgroup_add_lru_list(struct page *page, enum lru_list lru)
422 struct page_cgroup *pc;
423 struct mem_cgroup_per_zone *mz;
425 if (mem_cgroup_disabled())
426 return;
427 pc = lookup_page_cgroup(page);
429 * Used bit is set without atomic ops but after smp_wmb().
430 * For making pc->mem_cgroup visible, insert smp_rmb() here.
432 smp_rmb();
433 if (!PageCgroupUsed(pc))
434 return;
436 mz = page_cgroup_zoneinfo(pc);
437 MEM_CGROUP_ZSTAT(mz, lru) += 1;
438 list_add(&pc->lru, &mz->lists[lru]);
442 * At handling SwapCache, pc->mem_cgroup may be changed while it's linked to
443 * lru because the page may.be reused after it's fully uncharged (because of
444 * SwapCache behavior).To handle that, unlink page_cgroup from LRU when charge
445 * it again. This function is only used to charge SwapCache. It's done under
446 * lock_page and expected that zone->lru_lock is never held.
448 static void mem_cgroup_lru_del_before_commit_swapcache(struct page *page)
450 unsigned long flags;
451 struct zone *zone = page_zone(page);
452 struct page_cgroup *pc = lookup_page_cgroup(page);
454 spin_lock_irqsave(&zone->lru_lock, flags);
456 * Forget old LRU when this page_cgroup is *not* used. This Used bit
457 * is guarded by lock_page() because the page is SwapCache.
459 if (!PageCgroupUsed(pc))
460 mem_cgroup_del_lru_list(page, page_lru(page));
461 spin_unlock_irqrestore(&zone->lru_lock, flags);
464 static void mem_cgroup_lru_add_after_commit_swapcache(struct page *page)
466 unsigned long flags;
467 struct zone *zone = page_zone(page);
468 struct page_cgroup *pc = lookup_page_cgroup(page);
470 spin_lock_irqsave(&zone->lru_lock, flags);
471 /* link when the page is linked to LRU but page_cgroup isn't */
472 if (PageLRU(page) && list_empty(&pc->lru))
473 mem_cgroup_add_lru_list(page, page_lru(page));
474 spin_unlock_irqrestore(&zone->lru_lock, flags);
478 void mem_cgroup_move_lists(struct page *page,
479 enum lru_list from, enum lru_list to)
481 if (mem_cgroup_disabled())
482 return;
483 mem_cgroup_del_lru_list(page, from);
484 mem_cgroup_add_lru_list(page, to);
487 int task_in_mem_cgroup(struct task_struct *task, const struct mem_cgroup *mem)
489 int ret;
490 struct mem_cgroup *curr = NULL;
492 task_lock(task);
493 rcu_read_lock();
494 curr = try_get_mem_cgroup_from_mm(task->mm);
495 rcu_read_unlock();
496 task_unlock(task);
497 if (!curr)
498 return 0;
499 if (curr->use_hierarchy)
500 ret = css_is_ancestor(&curr->css, &mem->css);
501 else
502 ret = (curr == mem);
503 css_put(&curr->css);
504 return ret;
508 * prev_priority control...this will be used in memory reclaim path.
510 int mem_cgroup_get_reclaim_priority(struct mem_cgroup *mem)
512 int prev_priority;
514 spin_lock(&mem->reclaim_param_lock);
515 prev_priority = mem->prev_priority;
516 spin_unlock(&mem->reclaim_param_lock);
518 return prev_priority;
521 void mem_cgroup_note_reclaim_priority(struct mem_cgroup *mem, int priority)
523 spin_lock(&mem->reclaim_param_lock);
524 if (priority < mem->prev_priority)
525 mem->prev_priority = priority;
526 spin_unlock(&mem->reclaim_param_lock);
529 void mem_cgroup_record_reclaim_priority(struct mem_cgroup *mem, int priority)
531 spin_lock(&mem->reclaim_param_lock);
532 mem->prev_priority = priority;
533 spin_unlock(&mem->reclaim_param_lock);
536 static int calc_inactive_ratio(struct mem_cgroup *memcg, unsigned long *present_pages)
538 unsigned long active;
539 unsigned long inactive;
540 unsigned long gb;
541 unsigned long inactive_ratio;
543 inactive = mem_cgroup_get_local_zonestat(memcg, LRU_INACTIVE_ANON);
544 active = mem_cgroup_get_local_zonestat(memcg, LRU_ACTIVE_ANON);
546 gb = (inactive + active) >> (30 - PAGE_SHIFT);
547 if (gb)
548 inactive_ratio = int_sqrt(10 * gb);
549 else
550 inactive_ratio = 1;
552 if (present_pages) {
553 present_pages[0] = inactive;
554 present_pages[1] = active;
557 return inactive_ratio;
560 int mem_cgroup_inactive_anon_is_low(struct mem_cgroup *memcg)
562 unsigned long active;
563 unsigned long inactive;
564 unsigned long present_pages[2];
565 unsigned long inactive_ratio;
567 inactive_ratio = calc_inactive_ratio(memcg, present_pages);
569 inactive = present_pages[0];
570 active = present_pages[1];
572 if (inactive * inactive_ratio < active)
573 return 1;
575 return 0;
578 int mem_cgroup_inactive_file_is_low(struct mem_cgroup *memcg)
580 unsigned long active;
581 unsigned long inactive;
583 inactive = mem_cgroup_get_local_zonestat(memcg, LRU_INACTIVE_FILE);
584 active = mem_cgroup_get_local_zonestat(memcg, LRU_ACTIVE_FILE);
586 return (active > inactive);
589 unsigned long mem_cgroup_zone_nr_pages(struct mem_cgroup *memcg,
590 struct zone *zone,
591 enum lru_list lru)
593 int nid = zone->zone_pgdat->node_id;
594 int zid = zone_idx(zone);
595 struct mem_cgroup_per_zone *mz = mem_cgroup_zoneinfo(memcg, nid, zid);
597 return MEM_CGROUP_ZSTAT(mz, lru);
600 struct zone_reclaim_stat *mem_cgroup_get_reclaim_stat(struct mem_cgroup *memcg,
601 struct zone *zone)
603 int nid = zone->zone_pgdat->node_id;
604 int zid = zone_idx(zone);
605 struct mem_cgroup_per_zone *mz = mem_cgroup_zoneinfo(memcg, nid, zid);
607 return &mz->reclaim_stat;
610 struct zone_reclaim_stat *
611 mem_cgroup_get_reclaim_stat_from_page(struct page *page)
613 struct page_cgroup *pc;
614 struct mem_cgroup_per_zone *mz;
616 if (mem_cgroup_disabled())
617 return NULL;
619 pc = lookup_page_cgroup(page);
621 * Used bit is set without atomic ops but after smp_wmb().
622 * For making pc->mem_cgroup visible, insert smp_rmb() here.
624 smp_rmb();
625 if (!PageCgroupUsed(pc))
626 return NULL;
628 mz = page_cgroup_zoneinfo(pc);
629 if (!mz)
630 return NULL;
632 return &mz->reclaim_stat;
635 unsigned long mem_cgroup_isolate_pages(unsigned long nr_to_scan,
636 struct list_head *dst,
637 unsigned long *scanned, int order,
638 int mode, struct zone *z,
639 struct mem_cgroup *mem_cont,
640 int active, int file)
642 unsigned long nr_taken = 0;
643 struct page *page;
644 unsigned long scan;
645 LIST_HEAD(pc_list);
646 struct list_head *src;
647 struct page_cgroup *pc, *tmp;
648 int nid = z->zone_pgdat->node_id;
649 int zid = zone_idx(z);
650 struct mem_cgroup_per_zone *mz;
651 int lru = LRU_FILE * !!file + !!active;
652 int ret;
654 BUG_ON(!mem_cont);
655 mz = mem_cgroup_zoneinfo(mem_cont, nid, zid);
656 src = &mz->lists[lru];
658 scan = 0;
659 list_for_each_entry_safe_reverse(pc, tmp, src, lru) {
660 if (scan >= nr_to_scan)
661 break;
663 page = pc->page;
664 if (unlikely(!PageCgroupUsed(pc)))
665 continue;
666 if (unlikely(!PageLRU(page)))
667 continue;
669 scan++;
670 ret = __isolate_lru_page(page, mode, file);
671 switch (ret) {
672 case 0:
673 list_move(&page->lru, dst);
674 mem_cgroup_del_lru(page);
675 nr_taken++;
676 break;
677 case -EBUSY:
678 /* we don't affect global LRU but rotate in our LRU */
679 mem_cgroup_rotate_lru_list(page, page_lru(page));
680 break;
681 default:
682 break;
686 *scanned = scan;
687 return nr_taken;
690 #define mem_cgroup_from_res_counter(counter, member) \
691 container_of(counter, struct mem_cgroup, member)
693 static bool mem_cgroup_check_under_limit(struct mem_cgroup *mem)
695 if (do_swap_account) {
696 if (res_counter_check_under_limit(&mem->res) &&
697 res_counter_check_under_limit(&mem->memsw))
698 return true;
699 } else
700 if (res_counter_check_under_limit(&mem->res))
701 return true;
702 return false;
705 static unsigned int get_swappiness(struct mem_cgroup *memcg)
707 struct cgroup *cgrp = memcg->css.cgroup;
708 unsigned int swappiness;
710 /* root ? */
711 if (cgrp->parent == NULL)
712 return vm_swappiness;
714 spin_lock(&memcg->reclaim_param_lock);
715 swappiness = memcg->swappiness;
716 spin_unlock(&memcg->reclaim_param_lock);
718 return swappiness;
721 static int mem_cgroup_count_children_cb(struct mem_cgroup *mem, void *data)
723 int *val = data;
724 (*val)++;
725 return 0;
729 * mem_cgroup_print_mem_info: Called from OOM with tasklist_lock held in read mode.
730 * @memcg: The memory cgroup that went over limit
731 * @p: Task that is going to be killed
733 * NOTE: @memcg and @p's mem_cgroup can be different when hierarchy is
734 * enabled
736 void mem_cgroup_print_oom_info(struct mem_cgroup *memcg, struct task_struct *p)
738 struct cgroup *task_cgrp;
739 struct cgroup *mem_cgrp;
741 * Need a buffer in BSS, can't rely on allocations. The code relies
742 * on the assumption that OOM is serialized for memory controller.
743 * If this assumption is broken, revisit this code.
745 static char memcg_name[PATH_MAX];
746 int ret;
748 if (!memcg)
749 return;
752 rcu_read_lock();
754 mem_cgrp = memcg->css.cgroup;
755 task_cgrp = task_cgroup(p, mem_cgroup_subsys_id);
757 ret = cgroup_path(task_cgrp, memcg_name, PATH_MAX);
758 if (ret < 0) {
760 * Unfortunately, we are unable to convert to a useful name
761 * But we'll still print out the usage information
763 rcu_read_unlock();
764 goto done;
766 rcu_read_unlock();
768 printk(KERN_INFO "Task in %s killed", memcg_name);
770 rcu_read_lock();
771 ret = cgroup_path(mem_cgrp, memcg_name, PATH_MAX);
772 if (ret < 0) {
773 rcu_read_unlock();
774 goto done;
776 rcu_read_unlock();
779 * Continues from above, so we don't need an KERN_ level
781 printk(KERN_CONT " as a result of limit of %s\n", memcg_name);
782 done:
784 printk(KERN_INFO "memory: usage %llukB, limit %llukB, failcnt %llu\n",
785 res_counter_read_u64(&memcg->res, RES_USAGE) >> 10,
786 res_counter_read_u64(&memcg->res, RES_LIMIT) >> 10,
787 res_counter_read_u64(&memcg->res, RES_FAILCNT));
788 printk(KERN_INFO "memory+swap: usage %llukB, limit %llukB, "
789 "failcnt %llu\n",
790 res_counter_read_u64(&memcg->memsw, RES_USAGE) >> 10,
791 res_counter_read_u64(&memcg->memsw, RES_LIMIT) >> 10,
792 res_counter_read_u64(&memcg->memsw, RES_FAILCNT));
796 * This function returns the number of memcg under hierarchy tree. Returns
797 * 1(self count) if no children.
799 static int mem_cgroup_count_children(struct mem_cgroup *mem)
801 int num = 0;
802 mem_cgroup_walk_tree(mem, &num, mem_cgroup_count_children_cb);
803 return num;
807 * Visit the first child (need not be the first child as per the ordering
808 * of the cgroup list, since we track last_scanned_child) of @mem and use
809 * that to reclaim free pages from.
811 static struct mem_cgroup *
812 mem_cgroup_select_victim(struct mem_cgroup *root_mem)
814 struct mem_cgroup *ret = NULL;
815 struct cgroup_subsys_state *css;
816 int nextid, found;
818 if (!root_mem->use_hierarchy) {
819 css_get(&root_mem->css);
820 ret = root_mem;
823 while (!ret) {
824 rcu_read_lock();
825 nextid = root_mem->last_scanned_child + 1;
826 css = css_get_next(&mem_cgroup_subsys, nextid, &root_mem->css,
827 &found);
828 if (css && css_tryget(css))
829 ret = container_of(css, struct mem_cgroup, css);
831 rcu_read_unlock();
832 /* Updates scanning parameter */
833 spin_lock(&root_mem->reclaim_param_lock);
834 if (!css) {
835 /* this means start scan from ID:1 */
836 root_mem->last_scanned_child = 0;
837 } else
838 root_mem->last_scanned_child = found;
839 spin_unlock(&root_mem->reclaim_param_lock);
842 return ret;
846 * Scan the hierarchy if needed to reclaim memory. We remember the last child
847 * we reclaimed from, so that we don't end up penalizing one child extensively
848 * based on its position in the children list.
850 * root_mem is the original ancestor that we've been reclaim from.
852 * We give up and return to the caller when we visit root_mem twice.
853 * (other groups can be removed while we're walking....)
855 * If shrink==true, for avoiding to free too much, this returns immedieately.
857 static int mem_cgroup_hierarchical_reclaim(struct mem_cgroup *root_mem,
858 gfp_t gfp_mask, bool noswap, bool shrink)
860 struct mem_cgroup *victim;
861 int ret, total = 0;
862 int loop = 0;
864 /* If memsw_is_minimum==1, swap-out is of-no-use. */
865 if (root_mem->memsw_is_minimum)
866 noswap = true;
868 while (loop < 2) {
869 victim = mem_cgroup_select_victim(root_mem);
870 if (victim == root_mem)
871 loop++;
872 if (!mem_cgroup_local_usage(&victim->stat)) {
873 /* this cgroup's local usage == 0 */
874 css_put(&victim->css);
875 continue;
877 /* we use swappiness of local cgroup */
878 ret = try_to_free_mem_cgroup_pages(victim, gfp_mask, noswap,
879 get_swappiness(victim));
880 css_put(&victim->css);
882 * At shrinking usage, we can't check we should stop here or
883 * reclaim more. It's depends on callers. last_scanned_child
884 * will work enough for keeping fairness under tree.
886 if (shrink)
887 return ret;
888 total += ret;
889 if (mem_cgroup_check_under_limit(root_mem))
890 return 1 + total;
892 return total;
895 bool mem_cgroup_oom_called(struct task_struct *task)
897 bool ret = false;
898 struct mem_cgroup *mem;
899 struct mm_struct *mm;
901 rcu_read_lock();
902 mm = task->mm;
903 if (!mm)
904 mm = &init_mm;
905 mem = mem_cgroup_from_task(rcu_dereference(mm->owner));
906 if (mem && time_before(jiffies, mem->last_oom_jiffies + HZ/10))
907 ret = true;
908 rcu_read_unlock();
909 return ret;
912 static int record_last_oom_cb(struct mem_cgroup *mem, void *data)
914 mem->last_oom_jiffies = jiffies;
915 return 0;
918 static void record_last_oom(struct mem_cgroup *mem)
920 mem_cgroup_walk_tree(mem, NULL, record_last_oom_cb);
924 * Currently used to update mapped file statistics, but the routine can be
925 * generalized to update other statistics as well.
927 void mem_cgroup_update_mapped_file_stat(struct page *page, int val)
929 struct mem_cgroup *mem;
930 struct mem_cgroup_stat *stat;
931 struct mem_cgroup_stat_cpu *cpustat;
932 int cpu;
933 struct page_cgroup *pc;
935 if (!page_is_file_cache(page))
936 return;
938 pc = lookup_page_cgroup(page);
939 if (unlikely(!pc))
940 return;
942 lock_page_cgroup(pc);
943 mem = pc->mem_cgroup;
944 if (!mem)
945 goto done;
947 if (!PageCgroupUsed(pc))
948 goto done;
951 * Preemption is already disabled, we don't need get_cpu()
953 cpu = smp_processor_id();
954 stat = &mem->stat;
955 cpustat = &stat->cpustat[cpu];
957 __mem_cgroup_stat_add_safe(cpustat, MEM_CGROUP_STAT_MAPPED_FILE, val);
958 done:
959 unlock_page_cgroup(pc);
963 * Unlike exported interface, "oom" parameter is added. if oom==true,
964 * oom-killer can be invoked.
966 static int __mem_cgroup_try_charge(struct mm_struct *mm,
967 gfp_t gfp_mask, struct mem_cgroup **memcg,
968 bool oom)
970 struct mem_cgroup *mem, *mem_over_limit;
971 int nr_retries = MEM_CGROUP_RECLAIM_RETRIES;
972 struct res_counter *fail_res;
974 if (unlikely(test_thread_flag(TIF_MEMDIE))) {
975 /* Don't account this! */
976 *memcg = NULL;
977 return 0;
981 * We always charge the cgroup the mm_struct belongs to.
982 * The mm_struct's mem_cgroup changes on task migration if the
983 * thread group leader migrates. It's possible that mm is not
984 * set, if so charge the init_mm (happens for pagecache usage).
986 mem = *memcg;
987 if (likely(!mem)) {
988 mem = try_get_mem_cgroup_from_mm(mm);
989 *memcg = mem;
990 } else {
991 css_get(&mem->css);
993 if (unlikely(!mem))
994 return 0;
996 VM_BUG_ON(css_is_removed(&mem->css));
998 while (1) {
999 int ret;
1000 bool noswap = false;
1002 ret = res_counter_charge(&mem->res, PAGE_SIZE, &fail_res);
1003 if (likely(!ret)) {
1004 if (!do_swap_account)
1005 break;
1006 ret = res_counter_charge(&mem->memsw, PAGE_SIZE,
1007 &fail_res);
1008 if (likely(!ret))
1009 break;
1010 /* mem+swap counter fails */
1011 res_counter_uncharge(&mem->res, PAGE_SIZE);
1012 noswap = true;
1013 mem_over_limit = mem_cgroup_from_res_counter(fail_res,
1014 memsw);
1015 } else
1016 /* mem counter fails */
1017 mem_over_limit = mem_cgroup_from_res_counter(fail_res,
1018 res);
1020 if (!(gfp_mask & __GFP_WAIT))
1021 goto nomem;
1023 ret = mem_cgroup_hierarchical_reclaim(mem_over_limit, gfp_mask,
1024 noswap, false);
1025 if (ret)
1026 continue;
1029 * try_to_free_mem_cgroup_pages() might not give us a full
1030 * picture of reclaim. Some pages are reclaimed and might be
1031 * moved to swap cache or just unmapped from the cgroup.
1032 * Check the limit again to see if the reclaim reduced the
1033 * current usage of the cgroup before giving up
1036 if (mem_cgroup_check_under_limit(mem_over_limit))
1037 continue;
1039 if (!nr_retries--) {
1040 if (oom) {
1041 mutex_lock(&memcg_tasklist);
1042 mem_cgroup_out_of_memory(mem_over_limit, gfp_mask);
1043 mutex_unlock(&memcg_tasklist);
1044 record_last_oom(mem_over_limit);
1046 goto nomem;
1049 return 0;
1050 nomem:
1051 css_put(&mem->css);
1052 return -ENOMEM;
1057 * A helper function to get mem_cgroup from ID. must be called under
1058 * rcu_read_lock(). The caller must check css_is_removed() or some if
1059 * it's concern. (dropping refcnt from swap can be called against removed
1060 * memcg.)
1062 static struct mem_cgroup *mem_cgroup_lookup(unsigned short id)
1064 struct cgroup_subsys_state *css;
1066 /* ID 0 is unused ID */
1067 if (!id)
1068 return NULL;
1069 css = css_lookup(&mem_cgroup_subsys, id);
1070 if (!css)
1071 return NULL;
1072 return container_of(css, struct mem_cgroup, css);
1075 static struct mem_cgroup *try_get_mem_cgroup_from_swapcache(struct page *page)
1077 struct mem_cgroup *mem;
1078 struct page_cgroup *pc;
1079 unsigned short id;
1080 swp_entry_t ent;
1082 VM_BUG_ON(!PageLocked(page));
1084 if (!PageSwapCache(page))
1085 return NULL;
1087 pc = lookup_page_cgroup(page);
1088 lock_page_cgroup(pc);
1089 if (PageCgroupUsed(pc)) {
1090 mem = pc->mem_cgroup;
1091 if (mem && !css_tryget(&mem->css))
1092 mem = NULL;
1093 } else {
1094 ent.val = page_private(page);
1095 id = lookup_swap_cgroup(ent);
1096 rcu_read_lock();
1097 mem = mem_cgroup_lookup(id);
1098 if (mem && !css_tryget(&mem->css))
1099 mem = NULL;
1100 rcu_read_unlock();
1102 unlock_page_cgroup(pc);
1103 return mem;
1107 * commit a charge got by __mem_cgroup_try_charge() and makes page_cgroup to be
1108 * USED state. If already USED, uncharge and return.
1111 static void __mem_cgroup_commit_charge(struct mem_cgroup *mem,
1112 struct page_cgroup *pc,
1113 enum charge_type ctype)
1115 /* try_charge() can return NULL to *memcg, taking care of it. */
1116 if (!mem)
1117 return;
1119 lock_page_cgroup(pc);
1120 if (unlikely(PageCgroupUsed(pc))) {
1121 unlock_page_cgroup(pc);
1122 res_counter_uncharge(&mem->res, PAGE_SIZE);
1123 if (do_swap_account)
1124 res_counter_uncharge(&mem->memsw, PAGE_SIZE);
1125 css_put(&mem->css);
1126 return;
1128 pc->mem_cgroup = mem;
1129 smp_wmb();
1130 pc->flags = pcg_default_flags[ctype];
1132 mem_cgroup_charge_statistics(mem, pc, true);
1134 unlock_page_cgroup(pc);
1138 * mem_cgroup_move_account - move account of the page
1139 * @pc: page_cgroup of the page.
1140 * @from: mem_cgroup which the page is moved from.
1141 * @to: mem_cgroup which the page is moved to. @from != @to.
1143 * The caller must confirm following.
1144 * - page is not on LRU (isolate_page() is useful.)
1146 * returns 0 at success,
1147 * returns -EBUSY when lock is busy or "pc" is unstable.
1149 * This function does "uncharge" from old cgroup but doesn't do "charge" to
1150 * new cgroup. It should be done by a caller.
1153 static int mem_cgroup_move_account(struct page_cgroup *pc,
1154 struct mem_cgroup *from, struct mem_cgroup *to)
1156 struct mem_cgroup_per_zone *from_mz, *to_mz;
1157 int nid, zid;
1158 int ret = -EBUSY;
1159 struct page *page;
1160 int cpu;
1161 struct mem_cgroup_stat *stat;
1162 struct mem_cgroup_stat_cpu *cpustat;
1164 VM_BUG_ON(from == to);
1165 VM_BUG_ON(PageLRU(pc->page));
1167 nid = page_cgroup_nid(pc);
1168 zid = page_cgroup_zid(pc);
1169 from_mz = mem_cgroup_zoneinfo(from, nid, zid);
1170 to_mz = mem_cgroup_zoneinfo(to, nid, zid);
1172 if (!trylock_page_cgroup(pc))
1173 return ret;
1175 if (!PageCgroupUsed(pc))
1176 goto out;
1178 if (pc->mem_cgroup != from)
1179 goto out;
1181 res_counter_uncharge(&from->res, PAGE_SIZE);
1182 mem_cgroup_charge_statistics(from, pc, false);
1184 page = pc->page;
1185 if (page_is_file_cache(page) && page_mapped(page)) {
1186 cpu = smp_processor_id();
1187 /* Update mapped_file data for mem_cgroup "from" */
1188 stat = &from->stat;
1189 cpustat = &stat->cpustat[cpu];
1190 __mem_cgroup_stat_add_safe(cpustat, MEM_CGROUP_STAT_MAPPED_FILE,
1191 -1);
1193 /* Update mapped_file data for mem_cgroup "to" */
1194 stat = &to->stat;
1195 cpustat = &stat->cpustat[cpu];
1196 __mem_cgroup_stat_add_safe(cpustat, MEM_CGROUP_STAT_MAPPED_FILE,
1200 if (do_swap_account)
1201 res_counter_uncharge(&from->memsw, PAGE_SIZE);
1202 css_put(&from->css);
1204 css_get(&to->css);
1205 pc->mem_cgroup = to;
1206 mem_cgroup_charge_statistics(to, pc, true);
1207 ret = 0;
1208 out:
1209 unlock_page_cgroup(pc);
1210 return ret;
1214 * move charges to its parent.
1217 static int mem_cgroup_move_parent(struct page_cgroup *pc,
1218 struct mem_cgroup *child,
1219 gfp_t gfp_mask)
1221 struct page *page = pc->page;
1222 struct cgroup *cg = child->css.cgroup;
1223 struct cgroup *pcg = cg->parent;
1224 struct mem_cgroup *parent;
1225 int ret;
1227 /* Is ROOT ? */
1228 if (!pcg)
1229 return -EINVAL;
1232 parent = mem_cgroup_from_cont(pcg);
1235 ret = __mem_cgroup_try_charge(NULL, gfp_mask, &parent, false);
1236 if (ret || !parent)
1237 return ret;
1239 if (!get_page_unless_zero(page)) {
1240 ret = -EBUSY;
1241 goto uncharge;
1244 ret = isolate_lru_page(page);
1246 if (ret)
1247 goto cancel;
1249 ret = mem_cgroup_move_account(pc, child, parent);
1251 putback_lru_page(page);
1252 if (!ret) {
1253 put_page(page);
1254 /* drop extra refcnt by try_charge() */
1255 css_put(&parent->css);
1256 return 0;
1259 cancel:
1260 put_page(page);
1261 uncharge:
1262 /* drop extra refcnt by try_charge() */
1263 css_put(&parent->css);
1264 /* uncharge if move fails */
1265 res_counter_uncharge(&parent->res, PAGE_SIZE);
1266 if (do_swap_account)
1267 res_counter_uncharge(&parent->memsw, PAGE_SIZE);
1268 return ret;
1272 * Charge the memory controller for page usage.
1273 * Return
1274 * 0 if the charge was successful
1275 * < 0 if the cgroup is over its limit
1277 static int mem_cgroup_charge_common(struct page *page, struct mm_struct *mm,
1278 gfp_t gfp_mask, enum charge_type ctype,
1279 struct mem_cgroup *memcg)
1281 struct mem_cgroup *mem;
1282 struct page_cgroup *pc;
1283 int ret;
1285 pc = lookup_page_cgroup(page);
1286 /* can happen at boot */
1287 if (unlikely(!pc))
1288 return 0;
1289 prefetchw(pc);
1291 mem = memcg;
1292 ret = __mem_cgroup_try_charge(mm, gfp_mask, &mem, true);
1293 if (ret || !mem)
1294 return ret;
1296 __mem_cgroup_commit_charge(mem, pc, ctype);
1297 return 0;
1300 int mem_cgroup_newpage_charge(struct page *page,
1301 struct mm_struct *mm, gfp_t gfp_mask)
1303 if (mem_cgroup_disabled())
1304 return 0;
1305 if (PageCompound(page))
1306 return 0;
1308 * If already mapped, we don't have to account.
1309 * If page cache, page->mapping has address_space.
1310 * But page->mapping may have out-of-use anon_vma pointer,
1311 * detecit it by PageAnon() check. newly-mapped-anon's page->mapping
1312 * is NULL.
1314 if (page_mapped(page) || (page->mapping && !PageAnon(page)))
1315 return 0;
1316 if (unlikely(!mm))
1317 mm = &init_mm;
1318 return mem_cgroup_charge_common(page, mm, gfp_mask,
1319 MEM_CGROUP_CHARGE_TYPE_MAPPED, NULL);
1322 static void
1323 __mem_cgroup_commit_charge_swapin(struct page *page, struct mem_cgroup *ptr,
1324 enum charge_type ctype);
1326 int mem_cgroup_cache_charge(struct page *page, struct mm_struct *mm,
1327 gfp_t gfp_mask)
1329 struct mem_cgroup *mem = NULL;
1330 int ret;
1332 if (mem_cgroup_disabled())
1333 return 0;
1334 if (PageCompound(page))
1335 return 0;
1337 * Corner case handling. This is called from add_to_page_cache()
1338 * in usual. But some FS (shmem) precharges this page before calling it
1339 * and call add_to_page_cache() with GFP_NOWAIT.
1341 * For GFP_NOWAIT case, the page may be pre-charged before calling
1342 * add_to_page_cache(). (See shmem.c) check it here and avoid to call
1343 * charge twice. (It works but has to pay a bit larger cost.)
1344 * And when the page is SwapCache, it should take swap information
1345 * into account. This is under lock_page() now.
1347 if (!(gfp_mask & __GFP_WAIT)) {
1348 struct page_cgroup *pc;
1351 pc = lookup_page_cgroup(page);
1352 if (!pc)
1353 return 0;
1354 lock_page_cgroup(pc);
1355 if (PageCgroupUsed(pc)) {
1356 unlock_page_cgroup(pc);
1357 return 0;
1359 unlock_page_cgroup(pc);
1362 if (unlikely(!mm && !mem))
1363 mm = &init_mm;
1365 if (page_is_file_cache(page))
1366 return mem_cgroup_charge_common(page, mm, gfp_mask,
1367 MEM_CGROUP_CHARGE_TYPE_CACHE, NULL);
1369 /* shmem */
1370 if (PageSwapCache(page)) {
1371 ret = mem_cgroup_try_charge_swapin(mm, page, gfp_mask, &mem);
1372 if (!ret)
1373 __mem_cgroup_commit_charge_swapin(page, mem,
1374 MEM_CGROUP_CHARGE_TYPE_SHMEM);
1375 } else
1376 ret = mem_cgroup_charge_common(page, mm, gfp_mask,
1377 MEM_CGROUP_CHARGE_TYPE_SHMEM, mem);
1379 return ret;
1383 * While swap-in, try_charge -> commit or cancel, the page is locked.
1384 * And when try_charge() successfully returns, one refcnt to memcg without
1385 * struct page_cgroup is aquired. This refcnt will be cumsumed by
1386 * "commit()" or removed by "cancel()"
1388 int mem_cgroup_try_charge_swapin(struct mm_struct *mm,
1389 struct page *page,
1390 gfp_t mask, struct mem_cgroup **ptr)
1392 struct mem_cgroup *mem;
1393 int ret;
1395 if (mem_cgroup_disabled())
1396 return 0;
1398 if (!do_swap_account)
1399 goto charge_cur_mm;
1401 * A racing thread's fault, or swapoff, may have already updated
1402 * the pte, and even removed page from swap cache: return success
1403 * to go on to do_swap_page()'s pte_same() test, which should fail.
1405 if (!PageSwapCache(page))
1406 return 0;
1407 mem = try_get_mem_cgroup_from_swapcache(page);
1408 if (!mem)
1409 goto charge_cur_mm;
1410 *ptr = mem;
1411 ret = __mem_cgroup_try_charge(NULL, mask, ptr, true);
1412 /* drop extra refcnt from tryget */
1413 css_put(&mem->css);
1414 return ret;
1415 charge_cur_mm:
1416 if (unlikely(!mm))
1417 mm = &init_mm;
1418 return __mem_cgroup_try_charge(mm, mask, ptr, true);
1421 static void
1422 __mem_cgroup_commit_charge_swapin(struct page *page, struct mem_cgroup *ptr,
1423 enum charge_type ctype)
1425 struct page_cgroup *pc;
1427 if (mem_cgroup_disabled())
1428 return;
1429 if (!ptr)
1430 return;
1431 pc = lookup_page_cgroup(page);
1432 mem_cgroup_lru_del_before_commit_swapcache(page);
1433 __mem_cgroup_commit_charge(ptr, pc, ctype);
1434 mem_cgroup_lru_add_after_commit_swapcache(page);
1436 * Now swap is on-memory. This means this page may be
1437 * counted both as mem and swap....double count.
1438 * Fix it by uncharging from memsw. Basically, this SwapCache is stable
1439 * under lock_page(). But in do_swap_page()::memory.c, reuse_swap_page()
1440 * may call delete_from_swap_cache() before reach here.
1442 if (do_swap_account && PageSwapCache(page)) {
1443 swp_entry_t ent = {.val = page_private(page)};
1444 unsigned short id;
1445 struct mem_cgroup *memcg;
1447 id = swap_cgroup_record(ent, 0);
1448 rcu_read_lock();
1449 memcg = mem_cgroup_lookup(id);
1450 if (memcg) {
1452 * This recorded memcg can be obsolete one. So, avoid
1453 * calling css_tryget
1455 res_counter_uncharge(&memcg->memsw, PAGE_SIZE);
1456 mem_cgroup_put(memcg);
1458 rcu_read_unlock();
1460 /* add this page(page_cgroup) to the LRU we want. */
1464 void mem_cgroup_commit_charge_swapin(struct page *page, struct mem_cgroup *ptr)
1466 __mem_cgroup_commit_charge_swapin(page, ptr,
1467 MEM_CGROUP_CHARGE_TYPE_MAPPED);
1470 void mem_cgroup_cancel_charge_swapin(struct mem_cgroup *mem)
1472 if (mem_cgroup_disabled())
1473 return;
1474 if (!mem)
1475 return;
1476 res_counter_uncharge(&mem->res, PAGE_SIZE);
1477 if (do_swap_account)
1478 res_counter_uncharge(&mem->memsw, PAGE_SIZE);
1479 css_put(&mem->css);
1484 * uncharge if !page_mapped(page)
1486 static struct mem_cgroup *
1487 __mem_cgroup_uncharge_common(struct page *page, enum charge_type ctype)
1489 struct page_cgroup *pc;
1490 struct mem_cgroup *mem = NULL;
1491 struct mem_cgroup_per_zone *mz;
1493 if (mem_cgroup_disabled())
1494 return NULL;
1496 if (PageSwapCache(page))
1497 return NULL;
1500 * Check if our page_cgroup is valid
1502 pc = lookup_page_cgroup(page);
1503 if (unlikely(!pc || !PageCgroupUsed(pc)))
1504 return NULL;
1506 lock_page_cgroup(pc);
1508 mem = pc->mem_cgroup;
1510 if (!PageCgroupUsed(pc))
1511 goto unlock_out;
1513 switch (ctype) {
1514 case MEM_CGROUP_CHARGE_TYPE_MAPPED:
1515 case MEM_CGROUP_CHARGE_TYPE_DROP:
1516 if (page_mapped(page))
1517 goto unlock_out;
1518 break;
1519 case MEM_CGROUP_CHARGE_TYPE_SWAPOUT:
1520 if (!PageAnon(page)) { /* Shared memory */
1521 if (page->mapping && !page_is_file_cache(page))
1522 goto unlock_out;
1523 } else if (page_mapped(page)) /* Anon */
1524 goto unlock_out;
1525 break;
1526 default:
1527 break;
1530 res_counter_uncharge(&mem->res, PAGE_SIZE);
1531 if (do_swap_account && (ctype != MEM_CGROUP_CHARGE_TYPE_SWAPOUT))
1532 res_counter_uncharge(&mem->memsw, PAGE_SIZE);
1533 mem_cgroup_charge_statistics(mem, pc, false);
1535 ClearPageCgroupUsed(pc);
1537 * pc->mem_cgroup is not cleared here. It will be accessed when it's
1538 * freed from LRU. This is safe because uncharged page is expected not
1539 * to be reused (freed soon). Exception is SwapCache, it's handled by
1540 * special functions.
1543 mz = page_cgroup_zoneinfo(pc);
1544 unlock_page_cgroup(pc);
1546 /* at swapout, this memcg will be accessed to record to swap */
1547 if (ctype != MEM_CGROUP_CHARGE_TYPE_SWAPOUT)
1548 css_put(&mem->css);
1550 return mem;
1552 unlock_out:
1553 unlock_page_cgroup(pc);
1554 return NULL;
1557 void mem_cgroup_uncharge_page(struct page *page)
1559 /* early check. */
1560 if (page_mapped(page))
1561 return;
1562 if (page->mapping && !PageAnon(page))
1563 return;
1564 __mem_cgroup_uncharge_common(page, MEM_CGROUP_CHARGE_TYPE_MAPPED);
1567 void mem_cgroup_uncharge_cache_page(struct page *page)
1569 VM_BUG_ON(page_mapped(page));
1570 VM_BUG_ON(page->mapping);
1571 __mem_cgroup_uncharge_common(page, MEM_CGROUP_CHARGE_TYPE_CACHE);
1574 #ifdef CONFIG_SWAP
1576 * called after __delete_from_swap_cache() and drop "page" account.
1577 * memcg information is recorded to swap_cgroup of "ent"
1579 void
1580 mem_cgroup_uncharge_swapcache(struct page *page, swp_entry_t ent, bool swapout)
1582 struct mem_cgroup *memcg;
1583 int ctype = MEM_CGROUP_CHARGE_TYPE_SWAPOUT;
1585 if (!swapout) /* this was a swap cache but the swap is unused ! */
1586 ctype = MEM_CGROUP_CHARGE_TYPE_DROP;
1588 memcg = __mem_cgroup_uncharge_common(page, ctype);
1590 /* record memcg information */
1591 if (do_swap_account && swapout && memcg) {
1592 swap_cgroup_record(ent, css_id(&memcg->css));
1593 mem_cgroup_get(memcg);
1595 if (swapout && memcg)
1596 css_put(&memcg->css);
1598 #endif
1600 #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP
1602 * called from swap_entry_free(). remove record in swap_cgroup and
1603 * uncharge "memsw" account.
1605 void mem_cgroup_uncharge_swap(swp_entry_t ent)
1607 struct mem_cgroup *memcg;
1608 unsigned short id;
1610 if (!do_swap_account)
1611 return;
1613 id = swap_cgroup_record(ent, 0);
1614 rcu_read_lock();
1615 memcg = mem_cgroup_lookup(id);
1616 if (memcg) {
1618 * We uncharge this because swap is freed.
1619 * This memcg can be obsolete one. We avoid calling css_tryget
1621 res_counter_uncharge(&memcg->memsw, PAGE_SIZE);
1622 mem_cgroup_put(memcg);
1624 rcu_read_unlock();
1626 #endif
1629 * Before starting migration, account PAGE_SIZE to mem_cgroup that the old
1630 * page belongs to.
1632 int mem_cgroup_prepare_migration(struct page *page, struct mem_cgroup **ptr)
1634 struct page_cgroup *pc;
1635 struct mem_cgroup *mem = NULL;
1636 int ret = 0;
1638 if (mem_cgroup_disabled())
1639 return 0;
1641 pc = lookup_page_cgroup(page);
1642 lock_page_cgroup(pc);
1643 if (PageCgroupUsed(pc)) {
1644 mem = pc->mem_cgroup;
1645 css_get(&mem->css);
1647 unlock_page_cgroup(pc);
1649 if (mem) {
1650 ret = __mem_cgroup_try_charge(NULL, GFP_KERNEL, &mem, false);
1651 css_put(&mem->css);
1653 *ptr = mem;
1654 return ret;
1657 /* remove redundant charge if migration failed*/
1658 void mem_cgroup_end_migration(struct mem_cgroup *mem,
1659 struct page *oldpage, struct page *newpage)
1661 struct page *target, *unused;
1662 struct page_cgroup *pc;
1663 enum charge_type ctype;
1665 if (!mem)
1666 return;
1668 /* at migration success, oldpage->mapping is NULL. */
1669 if (oldpage->mapping) {
1670 target = oldpage;
1671 unused = NULL;
1672 } else {
1673 target = newpage;
1674 unused = oldpage;
1677 if (PageAnon(target))
1678 ctype = MEM_CGROUP_CHARGE_TYPE_MAPPED;
1679 else if (page_is_file_cache(target))
1680 ctype = MEM_CGROUP_CHARGE_TYPE_CACHE;
1681 else
1682 ctype = MEM_CGROUP_CHARGE_TYPE_SHMEM;
1684 /* unused page is not on radix-tree now. */
1685 if (unused)
1686 __mem_cgroup_uncharge_common(unused, ctype);
1688 pc = lookup_page_cgroup(target);
1690 * __mem_cgroup_commit_charge() check PCG_USED bit of page_cgroup.
1691 * So, double-counting is effectively avoided.
1693 __mem_cgroup_commit_charge(mem, pc, ctype);
1696 * Both of oldpage and newpage are still under lock_page().
1697 * Then, we don't have to care about race in radix-tree.
1698 * But we have to be careful that this page is unmapped or not.
1700 * There is a case for !page_mapped(). At the start of
1701 * migration, oldpage was mapped. But now, it's zapped.
1702 * But we know *target* page is not freed/reused under us.
1703 * mem_cgroup_uncharge_page() does all necessary checks.
1705 if (ctype == MEM_CGROUP_CHARGE_TYPE_MAPPED)
1706 mem_cgroup_uncharge_page(target);
1710 * A call to try to shrink memory usage on charge failure at shmem's swapin.
1711 * Calling hierarchical_reclaim is not enough because we should update
1712 * last_oom_jiffies to prevent pagefault_out_of_memory from invoking global OOM.
1713 * Moreover considering hierarchy, we should reclaim from the mem_over_limit,
1714 * not from the memcg which this page would be charged to.
1715 * try_charge_swapin does all of these works properly.
1717 int mem_cgroup_shmem_charge_fallback(struct page *page,
1718 struct mm_struct *mm,
1719 gfp_t gfp_mask)
1721 struct mem_cgroup *mem = NULL;
1722 int ret;
1724 if (mem_cgroup_disabled())
1725 return 0;
1727 ret = mem_cgroup_try_charge_swapin(mm, page, gfp_mask, &mem);
1728 if (!ret)
1729 mem_cgroup_cancel_charge_swapin(mem); /* it does !mem check */
1731 return ret;
1734 static DEFINE_MUTEX(set_limit_mutex);
1736 static int mem_cgroup_resize_limit(struct mem_cgroup *memcg,
1737 unsigned long long val)
1739 int retry_count;
1740 int progress;
1741 u64 memswlimit;
1742 int ret = 0;
1743 int children = mem_cgroup_count_children(memcg);
1744 u64 curusage, oldusage;
1747 * For keeping hierarchical_reclaim simple, how long we should retry
1748 * is depends on callers. We set our retry-count to be function
1749 * of # of children which we should visit in this loop.
1751 retry_count = MEM_CGROUP_RECLAIM_RETRIES * children;
1753 oldusage = res_counter_read_u64(&memcg->res, RES_USAGE);
1755 while (retry_count) {
1756 if (signal_pending(current)) {
1757 ret = -EINTR;
1758 break;
1761 * Rather than hide all in some function, I do this in
1762 * open coded manner. You see what this really does.
1763 * We have to guarantee mem->res.limit < mem->memsw.limit.
1765 mutex_lock(&set_limit_mutex);
1766 memswlimit = res_counter_read_u64(&memcg->memsw, RES_LIMIT);
1767 if (memswlimit < val) {
1768 ret = -EINVAL;
1769 mutex_unlock(&set_limit_mutex);
1770 break;
1772 ret = res_counter_set_limit(&memcg->res, val);
1773 if (!ret) {
1774 if (memswlimit == val)
1775 memcg->memsw_is_minimum = true;
1776 else
1777 memcg->memsw_is_minimum = false;
1779 mutex_unlock(&set_limit_mutex);
1781 if (!ret)
1782 break;
1784 progress = mem_cgroup_hierarchical_reclaim(memcg, GFP_KERNEL,
1785 false, true);
1786 curusage = res_counter_read_u64(&memcg->res, RES_USAGE);
1787 /* Usage is reduced ? */
1788 if (curusage >= oldusage)
1789 retry_count--;
1790 else
1791 oldusage = curusage;
1794 return ret;
1797 static int mem_cgroup_resize_memsw_limit(struct mem_cgroup *memcg,
1798 unsigned long long val)
1800 int retry_count;
1801 u64 memlimit, oldusage, curusage;
1802 int children = mem_cgroup_count_children(memcg);
1803 int ret = -EBUSY;
1805 /* see mem_cgroup_resize_res_limit */
1806 retry_count = children * MEM_CGROUP_RECLAIM_RETRIES;
1807 oldusage = res_counter_read_u64(&memcg->memsw, RES_USAGE);
1808 while (retry_count) {
1809 if (signal_pending(current)) {
1810 ret = -EINTR;
1811 break;
1814 * Rather than hide all in some function, I do this in
1815 * open coded manner. You see what this really does.
1816 * We have to guarantee mem->res.limit < mem->memsw.limit.
1818 mutex_lock(&set_limit_mutex);
1819 memlimit = res_counter_read_u64(&memcg->res, RES_LIMIT);
1820 if (memlimit > val) {
1821 ret = -EINVAL;
1822 mutex_unlock(&set_limit_mutex);
1823 break;
1825 ret = res_counter_set_limit(&memcg->memsw, val);
1826 if (!ret) {
1827 if (memlimit == val)
1828 memcg->memsw_is_minimum = true;
1829 else
1830 memcg->memsw_is_minimum = false;
1832 mutex_unlock(&set_limit_mutex);
1834 if (!ret)
1835 break;
1837 mem_cgroup_hierarchical_reclaim(memcg, GFP_KERNEL, true, true);
1838 curusage = res_counter_read_u64(&memcg->memsw, RES_USAGE);
1839 /* Usage is reduced ? */
1840 if (curusage >= oldusage)
1841 retry_count--;
1842 else
1843 oldusage = curusage;
1845 return ret;
1849 * This routine traverse page_cgroup in given list and drop them all.
1850 * *And* this routine doesn't reclaim page itself, just removes page_cgroup.
1852 static int mem_cgroup_force_empty_list(struct mem_cgroup *mem,
1853 int node, int zid, enum lru_list lru)
1855 struct zone *zone;
1856 struct mem_cgroup_per_zone *mz;
1857 struct page_cgroup *pc, *busy;
1858 unsigned long flags, loop;
1859 struct list_head *list;
1860 int ret = 0;
1862 zone = &NODE_DATA(node)->node_zones[zid];
1863 mz = mem_cgroup_zoneinfo(mem, node, zid);
1864 list = &mz->lists[lru];
1866 loop = MEM_CGROUP_ZSTAT(mz, lru);
1867 /* give some margin against EBUSY etc...*/
1868 loop += 256;
1869 busy = NULL;
1870 while (loop--) {
1871 ret = 0;
1872 spin_lock_irqsave(&zone->lru_lock, flags);
1873 if (list_empty(list)) {
1874 spin_unlock_irqrestore(&zone->lru_lock, flags);
1875 break;
1877 pc = list_entry(list->prev, struct page_cgroup, lru);
1878 if (busy == pc) {
1879 list_move(&pc->lru, list);
1880 busy = 0;
1881 spin_unlock_irqrestore(&zone->lru_lock, flags);
1882 continue;
1884 spin_unlock_irqrestore(&zone->lru_lock, flags);
1886 ret = mem_cgroup_move_parent(pc, mem, GFP_KERNEL);
1887 if (ret == -ENOMEM)
1888 break;
1890 if (ret == -EBUSY || ret == -EINVAL) {
1891 /* found lock contention or "pc" is obsolete. */
1892 busy = pc;
1893 cond_resched();
1894 } else
1895 busy = NULL;
1898 if (!ret && !list_empty(list))
1899 return -EBUSY;
1900 return ret;
1904 * make mem_cgroup's charge to be 0 if there is no task.
1905 * This enables deleting this mem_cgroup.
1907 static int mem_cgroup_force_empty(struct mem_cgroup *mem, bool free_all)
1909 int ret;
1910 int node, zid, shrink;
1911 int nr_retries = MEM_CGROUP_RECLAIM_RETRIES;
1912 struct cgroup *cgrp = mem->css.cgroup;
1914 css_get(&mem->css);
1916 shrink = 0;
1917 /* should free all ? */
1918 if (free_all)
1919 goto try_to_free;
1920 move_account:
1921 while (mem->res.usage > 0) {
1922 ret = -EBUSY;
1923 if (cgroup_task_count(cgrp) || !list_empty(&cgrp->children))
1924 goto out;
1925 ret = -EINTR;
1926 if (signal_pending(current))
1927 goto out;
1928 /* This is for making all *used* pages to be on LRU. */
1929 lru_add_drain_all();
1930 ret = 0;
1931 for_each_node_state(node, N_HIGH_MEMORY) {
1932 for (zid = 0; !ret && zid < MAX_NR_ZONES; zid++) {
1933 enum lru_list l;
1934 for_each_lru(l) {
1935 ret = mem_cgroup_force_empty_list(mem,
1936 node, zid, l);
1937 if (ret)
1938 break;
1941 if (ret)
1942 break;
1944 /* it seems parent cgroup doesn't have enough mem */
1945 if (ret == -ENOMEM)
1946 goto try_to_free;
1947 cond_resched();
1949 ret = 0;
1950 out:
1951 css_put(&mem->css);
1952 return ret;
1954 try_to_free:
1955 /* returns EBUSY if there is a task or if we come here twice. */
1956 if (cgroup_task_count(cgrp) || !list_empty(&cgrp->children) || shrink) {
1957 ret = -EBUSY;
1958 goto out;
1960 /* we call try-to-free pages for make this cgroup empty */
1961 lru_add_drain_all();
1962 /* try to free all pages in this cgroup */
1963 shrink = 1;
1964 while (nr_retries && mem->res.usage > 0) {
1965 int progress;
1967 if (signal_pending(current)) {
1968 ret = -EINTR;
1969 goto out;
1971 progress = try_to_free_mem_cgroup_pages(mem, GFP_KERNEL,
1972 false, get_swappiness(mem));
1973 if (!progress) {
1974 nr_retries--;
1975 /* maybe some writeback is necessary */
1976 congestion_wait(WRITE, HZ/10);
1980 lru_add_drain();
1981 /* try move_account...there may be some *locked* pages. */
1982 if (mem->res.usage)
1983 goto move_account;
1984 ret = 0;
1985 goto out;
1988 int mem_cgroup_force_empty_write(struct cgroup *cont, unsigned int event)
1990 return mem_cgroup_force_empty(mem_cgroup_from_cont(cont), true);
1994 static u64 mem_cgroup_hierarchy_read(struct cgroup *cont, struct cftype *cft)
1996 return mem_cgroup_from_cont(cont)->use_hierarchy;
1999 static int mem_cgroup_hierarchy_write(struct cgroup *cont, struct cftype *cft,
2000 u64 val)
2002 int retval = 0;
2003 struct mem_cgroup *mem = mem_cgroup_from_cont(cont);
2004 struct cgroup *parent = cont->parent;
2005 struct mem_cgroup *parent_mem = NULL;
2007 if (parent)
2008 parent_mem = mem_cgroup_from_cont(parent);
2010 cgroup_lock();
2012 * If parent's use_hiearchy is set, we can't make any modifications
2013 * in the child subtrees. If it is unset, then the change can
2014 * occur, provided the current cgroup has no children.
2016 * For the root cgroup, parent_mem is NULL, we allow value to be
2017 * set if there are no children.
2019 if ((!parent_mem || !parent_mem->use_hierarchy) &&
2020 (val == 1 || val == 0)) {
2021 if (list_empty(&cont->children))
2022 mem->use_hierarchy = val;
2023 else
2024 retval = -EBUSY;
2025 } else
2026 retval = -EINVAL;
2027 cgroup_unlock();
2029 return retval;
2032 static u64 mem_cgroup_read(struct cgroup *cont, struct cftype *cft)
2034 struct mem_cgroup *mem = mem_cgroup_from_cont(cont);
2035 u64 val = 0;
2036 int type, name;
2038 type = MEMFILE_TYPE(cft->private);
2039 name = MEMFILE_ATTR(cft->private);
2040 switch (type) {
2041 case _MEM:
2042 val = res_counter_read_u64(&mem->res, name);
2043 break;
2044 case _MEMSWAP:
2045 val = res_counter_read_u64(&mem->memsw, name);
2046 break;
2047 default:
2048 BUG();
2049 break;
2051 return val;
2054 * The user of this function is...
2055 * RES_LIMIT.
2057 static int mem_cgroup_write(struct cgroup *cont, struct cftype *cft,
2058 const char *buffer)
2060 struct mem_cgroup *memcg = mem_cgroup_from_cont(cont);
2061 int type, name;
2062 unsigned long long val;
2063 int ret;
2065 type = MEMFILE_TYPE(cft->private);
2066 name = MEMFILE_ATTR(cft->private);
2067 switch (name) {
2068 case RES_LIMIT:
2069 /* This function does all necessary parse...reuse it */
2070 ret = res_counter_memparse_write_strategy(buffer, &val);
2071 if (ret)
2072 break;
2073 if (type == _MEM)
2074 ret = mem_cgroup_resize_limit(memcg, val);
2075 else
2076 ret = mem_cgroup_resize_memsw_limit(memcg, val);
2077 break;
2078 default:
2079 ret = -EINVAL; /* should be BUG() ? */
2080 break;
2082 return ret;
2085 static void memcg_get_hierarchical_limit(struct mem_cgroup *memcg,
2086 unsigned long long *mem_limit, unsigned long long *memsw_limit)
2088 struct cgroup *cgroup;
2089 unsigned long long min_limit, min_memsw_limit, tmp;
2091 min_limit = res_counter_read_u64(&memcg->res, RES_LIMIT);
2092 min_memsw_limit = res_counter_read_u64(&memcg->memsw, RES_LIMIT);
2093 cgroup = memcg->css.cgroup;
2094 if (!memcg->use_hierarchy)
2095 goto out;
2097 while (cgroup->parent) {
2098 cgroup = cgroup->parent;
2099 memcg = mem_cgroup_from_cont(cgroup);
2100 if (!memcg->use_hierarchy)
2101 break;
2102 tmp = res_counter_read_u64(&memcg->res, RES_LIMIT);
2103 min_limit = min(min_limit, tmp);
2104 tmp = res_counter_read_u64(&memcg->memsw, RES_LIMIT);
2105 min_memsw_limit = min(min_memsw_limit, tmp);
2107 out:
2108 *mem_limit = min_limit;
2109 *memsw_limit = min_memsw_limit;
2110 return;
2113 static int mem_cgroup_reset(struct cgroup *cont, unsigned int event)
2115 struct mem_cgroup *mem;
2116 int type, name;
2118 mem = mem_cgroup_from_cont(cont);
2119 type = MEMFILE_TYPE(event);
2120 name = MEMFILE_ATTR(event);
2121 switch (name) {
2122 case RES_MAX_USAGE:
2123 if (type == _MEM)
2124 res_counter_reset_max(&mem->res);
2125 else
2126 res_counter_reset_max(&mem->memsw);
2127 break;
2128 case RES_FAILCNT:
2129 if (type == _MEM)
2130 res_counter_reset_failcnt(&mem->res);
2131 else
2132 res_counter_reset_failcnt(&mem->memsw);
2133 break;
2135 return 0;
2139 /* For read statistics */
2140 enum {
2141 MCS_CACHE,
2142 MCS_RSS,
2143 MCS_MAPPED_FILE,
2144 MCS_PGPGIN,
2145 MCS_PGPGOUT,
2146 MCS_INACTIVE_ANON,
2147 MCS_ACTIVE_ANON,
2148 MCS_INACTIVE_FILE,
2149 MCS_ACTIVE_FILE,
2150 MCS_UNEVICTABLE,
2151 NR_MCS_STAT,
2154 struct mcs_total_stat {
2155 s64 stat[NR_MCS_STAT];
2158 struct {
2159 char *local_name;
2160 char *total_name;
2161 } memcg_stat_strings[NR_MCS_STAT] = {
2162 {"cache", "total_cache"},
2163 {"rss", "total_rss"},
2164 {"mapped_file", "total_mapped_file"},
2165 {"pgpgin", "total_pgpgin"},
2166 {"pgpgout", "total_pgpgout"},
2167 {"inactive_anon", "total_inactive_anon"},
2168 {"active_anon", "total_active_anon"},
2169 {"inactive_file", "total_inactive_file"},
2170 {"active_file", "total_active_file"},
2171 {"unevictable", "total_unevictable"}
2175 static int mem_cgroup_get_local_stat(struct mem_cgroup *mem, void *data)
2177 struct mcs_total_stat *s = data;
2178 s64 val;
2180 /* per cpu stat */
2181 val = mem_cgroup_read_stat(&mem->stat, MEM_CGROUP_STAT_CACHE);
2182 s->stat[MCS_CACHE] += val * PAGE_SIZE;
2183 val = mem_cgroup_read_stat(&mem->stat, MEM_CGROUP_STAT_RSS);
2184 s->stat[MCS_RSS] += val * PAGE_SIZE;
2185 val = mem_cgroup_read_stat(&mem->stat, MEM_CGROUP_STAT_MAPPED_FILE);
2186 s->stat[MCS_MAPPED_FILE] += val * PAGE_SIZE;
2187 val = mem_cgroup_read_stat(&mem->stat, MEM_CGROUP_STAT_PGPGIN_COUNT);
2188 s->stat[MCS_PGPGIN] += val;
2189 val = mem_cgroup_read_stat(&mem->stat, MEM_CGROUP_STAT_PGPGOUT_COUNT);
2190 s->stat[MCS_PGPGOUT] += val;
2192 /* per zone stat */
2193 val = mem_cgroup_get_local_zonestat(mem, LRU_INACTIVE_ANON);
2194 s->stat[MCS_INACTIVE_ANON] += val * PAGE_SIZE;
2195 val = mem_cgroup_get_local_zonestat(mem, LRU_ACTIVE_ANON);
2196 s->stat[MCS_ACTIVE_ANON] += val * PAGE_SIZE;
2197 val = mem_cgroup_get_local_zonestat(mem, LRU_INACTIVE_FILE);
2198 s->stat[MCS_INACTIVE_FILE] += val * PAGE_SIZE;
2199 val = mem_cgroup_get_local_zonestat(mem, LRU_ACTIVE_FILE);
2200 s->stat[MCS_ACTIVE_FILE] += val * PAGE_SIZE;
2201 val = mem_cgroup_get_local_zonestat(mem, LRU_UNEVICTABLE);
2202 s->stat[MCS_UNEVICTABLE] += val * PAGE_SIZE;
2203 return 0;
2206 static void
2207 mem_cgroup_get_total_stat(struct mem_cgroup *mem, struct mcs_total_stat *s)
2209 mem_cgroup_walk_tree(mem, s, mem_cgroup_get_local_stat);
2212 static int mem_control_stat_show(struct cgroup *cont, struct cftype *cft,
2213 struct cgroup_map_cb *cb)
2215 struct mem_cgroup *mem_cont = mem_cgroup_from_cont(cont);
2216 struct mcs_total_stat mystat;
2217 int i;
2219 memset(&mystat, 0, sizeof(mystat));
2220 mem_cgroup_get_local_stat(mem_cont, &mystat);
2222 for (i = 0; i < NR_MCS_STAT; i++)
2223 cb->fill(cb, memcg_stat_strings[i].local_name, mystat.stat[i]);
2225 /* Hierarchical information */
2227 unsigned long long limit, memsw_limit;
2228 memcg_get_hierarchical_limit(mem_cont, &limit, &memsw_limit);
2229 cb->fill(cb, "hierarchical_memory_limit", limit);
2230 if (do_swap_account)
2231 cb->fill(cb, "hierarchical_memsw_limit", memsw_limit);
2234 memset(&mystat, 0, sizeof(mystat));
2235 mem_cgroup_get_total_stat(mem_cont, &mystat);
2236 for (i = 0; i < NR_MCS_STAT; i++)
2237 cb->fill(cb, memcg_stat_strings[i].total_name, mystat.stat[i]);
2240 #ifdef CONFIG_DEBUG_VM
2241 cb->fill(cb, "inactive_ratio", calc_inactive_ratio(mem_cont, NULL));
2244 int nid, zid;
2245 struct mem_cgroup_per_zone *mz;
2246 unsigned long recent_rotated[2] = {0, 0};
2247 unsigned long recent_scanned[2] = {0, 0};
2249 for_each_online_node(nid)
2250 for (zid = 0; zid < MAX_NR_ZONES; zid++) {
2251 mz = mem_cgroup_zoneinfo(mem_cont, nid, zid);
2253 recent_rotated[0] +=
2254 mz->reclaim_stat.recent_rotated[0];
2255 recent_rotated[1] +=
2256 mz->reclaim_stat.recent_rotated[1];
2257 recent_scanned[0] +=
2258 mz->reclaim_stat.recent_scanned[0];
2259 recent_scanned[1] +=
2260 mz->reclaim_stat.recent_scanned[1];
2262 cb->fill(cb, "recent_rotated_anon", recent_rotated[0]);
2263 cb->fill(cb, "recent_rotated_file", recent_rotated[1]);
2264 cb->fill(cb, "recent_scanned_anon", recent_scanned[0]);
2265 cb->fill(cb, "recent_scanned_file", recent_scanned[1]);
2267 #endif
2269 return 0;
2272 static u64 mem_cgroup_swappiness_read(struct cgroup *cgrp, struct cftype *cft)
2274 struct mem_cgroup *memcg = mem_cgroup_from_cont(cgrp);
2276 return get_swappiness(memcg);
2279 static int mem_cgroup_swappiness_write(struct cgroup *cgrp, struct cftype *cft,
2280 u64 val)
2282 struct mem_cgroup *memcg = mem_cgroup_from_cont(cgrp);
2283 struct mem_cgroup *parent;
2285 if (val > 100)
2286 return -EINVAL;
2288 if (cgrp->parent == NULL)
2289 return -EINVAL;
2291 parent = mem_cgroup_from_cont(cgrp->parent);
2293 cgroup_lock();
2295 /* If under hierarchy, only empty-root can set this value */
2296 if ((parent->use_hierarchy) ||
2297 (memcg->use_hierarchy && !list_empty(&cgrp->children))) {
2298 cgroup_unlock();
2299 return -EINVAL;
2302 spin_lock(&memcg->reclaim_param_lock);
2303 memcg->swappiness = val;
2304 spin_unlock(&memcg->reclaim_param_lock);
2306 cgroup_unlock();
2308 return 0;
2312 static struct cftype mem_cgroup_files[] = {
2314 .name = "usage_in_bytes",
2315 .private = MEMFILE_PRIVATE(_MEM, RES_USAGE),
2316 .read_u64 = mem_cgroup_read,
2319 .name = "max_usage_in_bytes",
2320 .private = MEMFILE_PRIVATE(_MEM, RES_MAX_USAGE),
2321 .trigger = mem_cgroup_reset,
2322 .read_u64 = mem_cgroup_read,
2325 .name = "limit_in_bytes",
2326 .private = MEMFILE_PRIVATE(_MEM, RES_LIMIT),
2327 .write_string = mem_cgroup_write,
2328 .read_u64 = mem_cgroup_read,
2331 .name = "failcnt",
2332 .private = MEMFILE_PRIVATE(_MEM, RES_FAILCNT),
2333 .trigger = mem_cgroup_reset,
2334 .read_u64 = mem_cgroup_read,
2337 .name = "stat",
2338 .read_map = mem_control_stat_show,
2341 .name = "force_empty",
2342 .trigger = mem_cgroup_force_empty_write,
2345 .name = "use_hierarchy",
2346 .write_u64 = mem_cgroup_hierarchy_write,
2347 .read_u64 = mem_cgroup_hierarchy_read,
2350 .name = "swappiness",
2351 .read_u64 = mem_cgroup_swappiness_read,
2352 .write_u64 = mem_cgroup_swappiness_write,
2356 #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP
2357 static struct cftype memsw_cgroup_files[] = {
2359 .name = "memsw.usage_in_bytes",
2360 .private = MEMFILE_PRIVATE(_MEMSWAP, RES_USAGE),
2361 .read_u64 = mem_cgroup_read,
2364 .name = "memsw.max_usage_in_bytes",
2365 .private = MEMFILE_PRIVATE(_MEMSWAP, RES_MAX_USAGE),
2366 .trigger = mem_cgroup_reset,
2367 .read_u64 = mem_cgroup_read,
2370 .name = "memsw.limit_in_bytes",
2371 .private = MEMFILE_PRIVATE(_MEMSWAP, RES_LIMIT),
2372 .write_string = mem_cgroup_write,
2373 .read_u64 = mem_cgroup_read,
2376 .name = "memsw.failcnt",
2377 .private = MEMFILE_PRIVATE(_MEMSWAP, RES_FAILCNT),
2378 .trigger = mem_cgroup_reset,
2379 .read_u64 = mem_cgroup_read,
2383 static int register_memsw_files(struct cgroup *cont, struct cgroup_subsys *ss)
2385 if (!do_swap_account)
2386 return 0;
2387 return cgroup_add_files(cont, ss, memsw_cgroup_files,
2388 ARRAY_SIZE(memsw_cgroup_files));
2390 #else
2391 static int register_memsw_files(struct cgroup *cont, struct cgroup_subsys *ss)
2393 return 0;
2395 #endif
2397 static int alloc_mem_cgroup_per_zone_info(struct mem_cgroup *mem, int node)
2399 struct mem_cgroup_per_node *pn;
2400 struct mem_cgroup_per_zone *mz;
2401 enum lru_list l;
2402 int zone, tmp = node;
2404 * This routine is called against possible nodes.
2405 * But it's BUG to call kmalloc() against offline node.
2407 * TODO: this routine can waste much memory for nodes which will
2408 * never be onlined. It's better to use memory hotplug callback
2409 * function.
2411 if (!node_state(node, N_NORMAL_MEMORY))
2412 tmp = -1;
2413 pn = kmalloc_node(sizeof(*pn), GFP_KERNEL, tmp);
2414 if (!pn)
2415 return 1;
2417 mem->info.nodeinfo[node] = pn;
2418 memset(pn, 0, sizeof(*pn));
2420 for (zone = 0; zone < MAX_NR_ZONES; zone++) {
2421 mz = &pn->zoneinfo[zone];
2422 for_each_lru(l)
2423 INIT_LIST_HEAD(&mz->lists[l]);
2425 return 0;
2428 static void free_mem_cgroup_per_zone_info(struct mem_cgroup *mem, int node)
2430 kfree(mem->info.nodeinfo[node]);
2433 static int mem_cgroup_size(void)
2435 int cpustat_size = nr_cpu_ids * sizeof(struct mem_cgroup_stat_cpu);
2436 return sizeof(struct mem_cgroup) + cpustat_size;
2439 static struct mem_cgroup *mem_cgroup_alloc(void)
2441 struct mem_cgroup *mem;
2442 int size = mem_cgroup_size();
2444 if (size < PAGE_SIZE)
2445 mem = kmalloc(size, GFP_KERNEL);
2446 else
2447 mem = vmalloc(size);
2449 if (mem)
2450 memset(mem, 0, size);
2451 return mem;
2455 * At destroying mem_cgroup, references from swap_cgroup can remain.
2456 * (scanning all at force_empty is too costly...)
2458 * Instead of clearing all references at force_empty, we remember
2459 * the number of reference from swap_cgroup and free mem_cgroup when
2460 * it goes down to 0.
2462 * Removal of cgroup itself succeeds regardless of refs from swap.
2465 static void __mem_cgroup_free(struct mem_cgroup *mem)
2467 int node;
2469 free_css_id(&mem_cgroup_subsys, &mem->css);
2471 for_each_node_state(node, N_POSSIBLE)
2472 free_mem_cgroup_per_zone_info(mem, node);
2474 if (mem_cgroup_size() < PAGE_SIZE)
2475 kfree(mem);
2476 else
2477 vfree(mem);
2480 static void mem_cgroup_get(struct mem_cgroup *mem)
2482 atomic_inc(&mem->refcnt);
2485 static void mem_cgroup_put(struct mem_cgroup *mem)
2487 if (atomic_dec_and_test(&mem->refcnt)) {
2488 struct mem_cgroup *parent = parent_mem_cgroup(mem);
2489 __mem_cgroup_free(mem);
2490 if (parent)
2491 mem_cgroup_put(parent);
2496 * Returns the parent mem_cgroup in memcgroup hierarchy with hierarchy enabled.
2498 static struct mem_cgroup *parent_mem_cgroup(struct mem_cgroup *mem)
2500 if (!mem->res.parent)
2501 return NULL;
2502 return mem_cgroup_from_res_counter(mem->res.parent, res);
2505 #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP
2506 static void __init enable_swap_cgroup(void)
2508 if (!mem_cgroup_disabled() && really_do_swap_account)
2509 do_swap_account = 1;
2511 #else
2512 static void __init enable_swap_cgroup(void)
2515 #endif
2517 static struct cgroup_subsys_state * __ref
2518 mem_cgroup_create(struct cgroup_subsys *ss, struct cgroup *cont)
2520 struct mem_cgroup *mem, *parent;
2521 long error = -ENOMEM;
2522 int node;
2524 mem = mem_cgroup_alloc();
2525 if (!mem)
2526 return ERR_PTR(error);
2528 for_each_node_state(node, N_POSSIBLE)
2529 if (alloc_mem_cgroup_per_zone_info(mem, node))
2530 goto free_out;
2531 /* root ? */
2532 if (cont->parent == NULL) {
2533 enable_swap_cgroup();
2534 parent = NULL;
2535 } else {
2536 parent = mem_cgroup_from_cont(cont->parent);
2537 mem->use_hierarchy = parent->use_hierarchy;
2540 if (parent && parent->use_hierarchy) {
2541 res_counter_init(&mem->res, &parent->res);
2542 res_counter_init(&mem->memsw, &parent->memsw);
2544 * We increment refcnt of the parent to ensure that we can
2545 * safely access it on res_counter_charge/uncharge.
2546 * This refcnt will be decremented when freeing this
2547 * mem_cgroup(see mem_cgroup_put).
2549 mem_cgroup_get(parent);
2550 } else {
2551 res_counter_init(&mem->res, NULL);
2552 res_counter_init(&mem->memsw, NULL);
2554 mem->last_scanned_child = 0;
2555 spin_lock_init(&mem->reclaim_param_lock);
2557 if (parent)
2558 mem->swappiness = get_swappiness(parent);
2559 atomic_set(&mem->refcnt, 1);
2560 return &mem->css;
2561 free_out:
2562 __mem_cgroup_free(mem);
2563 return ERR_PTR(error);
2566 static int mem_cgroup_pre_destroy(struct cgroup_subsys *ss,
2567 struct cgroup *cont)
2569 struct mem_cgroup *mem = mem_cgroup_from_cont(cont);
2571 return mem_cgroup_force_empty(mem, false);
2574 static void mem_cgroup_destroy(struct cgroup_subsys *ss,
2575 struct cgroup *cont)
2577 struct mem_cgroup *mem = mem_cgroup_from_cont(cont);
2579 mem_cgroup_put(mem);
2582 static int mem_cgroup_populate(struct cgroup_subsys *ss,
2583 struct cgroup *cont)
2585 int ret;
2587 ret = cgroup_add_files(cont, ss, mem_cgroup_files,
2588 ARRAY_SIZE(mem_cgroup_files));
2590 if (!ret)
2591 ret = register_memsw_files(cont, ss);
2592 return ret;
2595 static void mem_cgroup_move_task(struct cgroup_subsys *ss,
2596 struct cgroup *cont,
2597 struct cgroup *old_cont,
2598 struct task_struct *p)
2600 mutex_lock(&memcg_tasklist);
2602 * FIXME: It's better to move charges of this process from old
2603 * memcg to new memcg. But it's just on TODO-List now.
2605 mutex_unlock(&memcg_tasklist);
2608 struct cgroup_subsys mem_cgroup_subsys = {
2609 .name = "memory",
2610 .subsys_id = mem_cgroup_subsys_id,
2611 .create = mem_cgroup_create,
2612 .pre_destroy = mem_cgroup_pre_destroy,
2613 .destroy = mem_cgroup_destroy,
2614 .populate = mem_cgroup_populate,
2615 .attach = mem_cgroup_move_task,
2616 .early_init = 0,
2617 .use_id = 1,
2620 #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP
2622 static int __init disable_swap_account(char *s)
2624 really_do_swap_account = 0;
2625 return 1;
2627 __setup("noswapaccount", disable_swap_account);
2628 #endif