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Balbir Singh8cdea7c2008-02-07 00:13:50 -08001/* memcontrol.c - Memory Controller
2 *
3 * Copyright IBM Corporation, 2007
4 * Author Balbir Singh <balbir@linux.vnet.ibm.com>
5 *
Pavel Emelianov78fb7462008-02-07 00:13:51 -08006 * Copyright 2007 OpenVZ SWsoft Inc
7 * Author: Pavel Emelianov <xemul@openvz.org>
8 *
Kirill A. Shutemov2e72b632010-03-10 15:22:24 -08009 * Memory thresholds
10 * Copyright (C) 2009 Nokia Corporation
11 * Author: Kirill A. Shutemov
12 *
Balbir Singh8cdea7c2008-02-07 00:13:50 -080013 * This program is free software; you can redistribute it and/or modify
14 * it under the terms of the GNU General Public License as published by
15 * the Free Software Foundation; either version 2 of the License, or
16 * (at your option) any later version.
17 *
18 * This program is distributed in the hope that it will be useful,
19 * but WITHOUT ANY WARRANTY; without even the implied warranty of
20 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
21 * GNU General Public License for more details.
22 */
23
24#include <linux/res_counter.h>
25#include <linux/memcontrol.h>
26#include <linux/cgroup.h>
Pavel Emelianov78fb7462008-02-07 00:13:51 -080027#include <linux/mm.h>
Daisuke Nishimura4ffef5f2010-03-10 15:22:14 -080028#include <linux/hugetlb.h>
KAMEZAWA Hiroyukid13d1442009-01-07 18:07:56 -080029#include <linux/pagemap.h>
KAMEZAWA Hiroyukid52aa412008-02-07 00:14:24 -080030#include <linux/smp.h>
Balbir Singh8a9f3cc2008-02-07 00:13:53 -080031#include <linux/page-flags.h>
Balbir Singh66e17072008-02-07 00:13:56 -080032#include <linux/backing-dev.h>
Balbir Singh8a9f3cc2008-02-07 00:13:53 -080033#include <linux/bit_spinlock.h>
34#include <linux/rcupdate.h>
Balbir Singhe2224322009-04-02 16:57:39 -070035#include <linux/limits.h>
KAMEZAWA Hiroyuki8c7c6e342009-01-07 18:08:00 -080036#include <linux/mutex.h>
Balbir Singhf64c3f52009-09-23 15:56:37 -070037#include <linux/rbtree.h>
Balbir Singhb6ac57d2008-04-29 01:00:19 -070038#include <linux/slab.h>
Balbir Singh66e17072008-02-07 00:13:56 -080039#include <linux/swap.h>
Daisuke Nishimura02491442010-03-10 15:22:17 -080040#include <linux/swapops.h>
Balbir Singh66e17072008-02-07 00:13:56 -080041#include <linux/spinlock.h>
Kirill A. Shutemov2e72b632010-03-10 15:22:24 -080042#include <linux/eventfd.h>
43#include <linux/sort.h>
Balbir Singh66e17072008-02-07 00:13:56 -080044#include <linux/fs.h>
KAMEZAWA Hiroyukid2ceb9b2008-02-07 00:14:25 -080045#include <linux/seq_file.h>
KAMEZAWA Hiroyuki33327942008-04-29 01:00:24 -070046#include <linux/vmalloc.h>
Christoph Lameterb69408e2008-10-18 20:26:14 -070047#include <linux/mm_inline.h>
KAMEZAWA Hiroyuki52d4b9a2008-10-18 20:28:16 -070048#include <linux/page_cgroup.h>
KAMEZAWA Hiroyukicdec2e42009-12-15 16:47:08 -080049#include <linux/cpu.h>
KAMEZAWA Hiroyuki158e0a22010-08-10 18:03:00 -070050#include <linux/oom.h>
KAMEZAWA Hiroyuki08e552c2009-01-07 18:08:01 -080051#include "internal.h"
Balbir Singh8cdea7c2008-02-07 00:13:50 -080052
Balbir Singh8697d332008-02-07 00:13:59 -080053#include <asm/uaccess.h>
54
KOSAKI Motohirocc8e9702010-08-09 17:19:57 -070055#include <trace/events/vmscan.h>
56
KAMEZAWA Hiroyukia181b0e2008-07-25 01:47:08 -070057struct cgroup_subsys mem_cgroup_subsys __read_mostly;
KAMEZAWA Hiroyukia181b0e2008-07-25 01:47:08 -070058#define MEM_CGROUP_RECLAIM_RETRIES 5
Balbir Singh4b3bde42009-09-23 15:56:32 -070059struct mem_cgroup *root_mem_cgroup __read_mostly;
Balbir Singh8cdea7c2008-02-07 00:13:50 -080060
KAMEZAWA Hiroyukic0777192009-01-07 18:07:57 -080061#ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP
Li Zefan338c8432009-06-17 16:27:15 -070062/* Turned on only when memory cgroup is enabled && really_do_swap_account = 1 */
KAMEZAWA Hiroyukic0777192009-01-07 18:07:57 -080063int do_swap_account __read_mostly;
64static int really_do_swap_account __initdata = 1; /* for remember boot option*/
65#else
66#define do_swap_account (0)
67#endif
68
KAMEZAWA Hiroyukid2265e62010-03-10 15:22:31 -080069/*
70 * Per memcg event counter is incremented at every pagein/pageout. This counter
71 * is used for trigger some periodic events. This is straightforward and better
72 * than using jiffies etc. to handle periodic memcg event.
73 *
74 * These values will be used as !((event) & ((1 <<(thresh)) - 1))
75 */
76#define THRESHOLDS_EVENTS_THRESH (7) /* once in 128 */
77#define SOFTLIMIT_EVENTS_THRESH (10) /* once in 1024 */
KAMEZAWA Hiroyukic0777192009-01-07 18:07:57 -080078
Balbir Singh8cdea7c2008-02-07 00:13:50 -080079/*
KAMEZAWA Hiroyukid52aa412008-02-07 00:14:24 -080080 * Statistics for memory cgroup.
81 */
82enum mem_cgroup_stat_index {
83 /*
84 * For MEM_CONTAINER_TYPE_ALL, usage = pagecache + rss.
85 */
86 MEM_CGROUP_STAT_CACHE, /* # of pages charged as cache */
Balbir Singhd69b0422009-06-17 16:26:34 -070087 MEM_CGROUP_STAT_RSS, /* # of pages charged as anon rss */
KAMEZAWA Hiroyukid8046582009-12-15 16:47:09 -080088 MEM_CGROUP_STAT_FILE_MAPPED, /* # of pages charged as file rss */
Balaji Rao55e462b2008-05-01 04:35:12 -070089 MEM_CGROUP_STAT_PGPGIN_COUNT, /* # of pages paged in */
90 MEM_CGROUP_STAT_PGPGOUT_COUNT, /* # of pages paged out */
Balbir Singh0c3e73e2009-09-23 15:56:42 -070091 MEM_CGROUP_STAT_SWAPOUT, /* # of pages, swapped out */
KAMEZAWA Hiroyuki711d3d22010-10-27 15:33:42 -070092 MEM_CGROUP_STAT_DATA, /* end of data requires synchronization */
93 /* incremented at every pagein/pageout */
94 MEM_CGROUP_EVENTS = MEM_CGROUP_STAT_DATA,
KAMEZAWA Hiroyuki32047e22010-10-27 15:33:40 -070095 MEM_CGROUP_ON_MOVE, /* someone is moving account between groups */
KAMEZAWA Hiroyukid52aa412008-02-07 00:14:24 -080096
97 MEM_CGROUP_STAT_NSTATS,
98};
99
100struct mem_cgroup_stat_cpu {
101 s64 count[MEM_CGROUP_STAT_NSTATS];
KAMEZAWA Hiroyukid52aa412008-02-07 00:14:24 -0800102};
103
KAMEZAWA Hiroyukid52aa412008-02-07 00:14:24 -0800104/*
KAMEZAWA Hiroyuki6d12e2d2008-02-07 00:14:31 -0800105 * per-zone information in memory controller.
106 */
KAMEZAWA Hiroyuki6d12e2d2008-02-07 00:14:31 -0800107struct mem_cgroup_per_zone {
KAMEZAWA Hiroyuki072c56c12008-02-07 00:14:39 -0800108 /*
109 * spin_lock to protect the per cgroup LRU
110 */
Christoph Lameterb69408e2008-10-18 20:26:14 -0700111 struct list_head lists[NR_LRU_LISTS];
112 unsigned long count[NR_LRU_LISTS];
KOSAKI Motohiro3e2f41f2009-01-07 18:08:20 -0800113
114 struct zone_reclaim_stat reclaim_stat;
Balbir Singhf64c3f52009-09-23 15:56:37 -0700115 struct rb_node tree_node; /* RB tree node */
116 unsigned long long usage_in_excess;/* Set to the value by which */
117 /* the soft limit is exceeded*/
118 bool on_tree;
Balbir Singh4e416952009-09-23 15:56:39 -0700119 struct mem_cgroup *mem; /* Back pointer, we cannot */
120 /* use container_of */
KAMEZAWA Hiroyuki6d12e2d2008-02-07 00:14:31 -0800121};
122/* Macro for accessing counter */
123#define MEM_CGROUP_ZSTAT(mz, idx) ((mz)->count[(idx)])
124
125struct mem_cgroup_per_node {
126 struct mem_cgroup_per_zone zoneinfo[MAX_NR_ZONES];
127};
128
129struct mem_cgroup_lru_info {
130 struct mem_cgroup_per_node *nodeinfo[MAX_NUMNODES];
131};
132
133/*
Balbir Singhf64c3f52009-09-23 15:56:37 -0700134 * Cgroups above their limits are maintained in a RB-Tree, independent of
135 * their hierarchy representation
136 */
137
138struct mem_cgroup_tree_per_zone {
139 struct rb_root rb_root;
140 spinlock_t lock;
141};
142
143struct mem_cgroup_tree_per_node {
144 struct mem_cgroup_tree_per_zone rb_tree_per_zone[MAX_NR_ZONES];
145};
146
147struct mem_cgroup_tree {
148 struct mem_cgroup_tree_per_node *rb_tree_per_node[MAX_NUMNODES];
149};
150
151static struct mem_cgroup_tree soft_limit_tree __read_mostly;
152
Kirill A. Shutemov2e72b632010-03-10 15:22:24 -0800153struct mem_cgroup_threshold {
154 struct eventfd_ctx *eventfd;
155 u64 threshold;
156};
157
KAMEZAWA Hiroyuki9490ff22010-05-26 14:42:36 -0700158/* For threshold */
Kirill A. Shutemov2e72b632010-03-10 15:22:24 -0800159struct mem_cgroup_threshold_ary {
160 /* An array index points to threshold just below usage. */
Phil Carmody5407a562010-05-26 14:42:42 -0700161 int current_threshold;
Kirill A. Shutemov2e72b632010-03-10 15:22:24 -0800162 /* Size of entries[] */
163 unsigned int size;
164 /* Array of thresholds */
165 struct mem_cgroup_threshold entries[0];
166};
Kirill A. Shutemov2c488db2010-05-26 14:42:47 -0700167
168struct mem_cgroup_thresholds {
169 /* Primary thresholds array */
170 struct mem_cgroup_threshold_ary *primary;
171 /*
172 * Spare threshold array.
173 * This is needed to make mem_cgroup_unregister_event() "never fail".
174 * It must be able to store at least primary->size - 1 entries.
175 */
176 struct mem_cgroup_threshold_ary *spare;
177};
178
KAMEZAWA Hiroyuki9490ff22010-05-26 14:42:36 -0700179/* for OOM */
180struct mem_cgroup_eventfd_list {
181 struct list_head list;
182 struct eventfd_ctx *eventfd;
183};
Kirill A. Shutemov2e72b632010-03-10 15:22:24 -0800184
Kirill A. Shutemov2e72b632010-03-10 15:22:24 -0800185static void mem_cgroup_threshold(struct mem_cgroup *mem);
KAMEZAWA Hiroyuki9490ff22010-05-26 14:42:36 -0700186static void mem_cgroup_oom_notify(struct mem_cgroup *mem);
Kirill A. Shutemov2e72b632010-03-10 15:22:24 -0800187
Balbir Singhf64c3f52009-09-23 15:56:37 -0700188/*
Balbir Singh8cdea7c2008-02-07 00:13:50 -0800189 * The memory controller data structure. The memory controller controls both
190 * page cache and RSS per cgroup. We would eventually like to provide
191 * statistics based on the statistics developed by Rik Van Riel for clock-pro,
192 * to help the administrator determine what knobs to tune.
193 *
194 * TODO: Add a water mark for the memory controller. Reclaim will begin when
Balbir Singh8a9f3cc2008-02-07 00:13:53 -0800195 * we hit the water mark. May be even add a low water mark, such that
196 * no reclaim occurs from a cgroup at it's low water mark, this is
197 * a feature that will be implemented much later in the future.
Balbir Singh8cdea7c2008-02-07 00:13:50 -0800198 */
199struct mem_cgroup {
200 struct cgroup_subsys_state css;
201 /*
202 * the counter to account for memory usage
203 */
204 struct res_counter res;
Pavel Emelianov78fb7462008-02-07 00:13:51 -0800205 /*
KAMEZAWA Hiroyuki8c7c6e342009-01-07 18:08:00 -0800206 * the counter to account for mem+swap usage.
207 */
208 struct res_counter memsw;
209 /*
Pavel Emelianov78fb7462008-02-07 00:13:51 -0800210 * Per cgroup active and inactive list, similar to the
211 * per zone LRU lists.
Pavel Emelianov78fb7462008-02-07 00:13:51 -0800212 */
KAMEZAWA Hiroyuki6d12e2d2008-02-07 00:14:31 -0800213 struct mem_cgroup_lru_info info;
KAMEZAWA Hiroyuki072c56c12008-02-07 00:14:39 -0800214
KOSAKI Motohiro2733c062009-01-07 18:08:23 -0800215 /*
216 protect against reclaim related member.
217 */
218 spinlock_t reclaim_param_lock;
219
Balbir Singh6d61ef42009-01-07 18:08:06 -0800220 /*
André Goddard Rosaaf901ca2009-11-14 13:09:05 -0200221 * While reclaiming in a hierarchy, we cache the last child we
KAMEZAWA Hiroyuki04046e12009-04-02 16:57:33 -0700222 * reclaimed from.
Balbir Singh6d61ef42009-01-07 18:08:06 -0800223 */
KAMEZAWA Hiroyuki04046e12009-04-02 16:57:33 -0700224 int last_scanned_child;
Balbir Singh18f59ea2009-01-07 18:08:07 -0800225 /*
226 * Should the accounting and control be hierarchical, per subtree?
227 */
228 bool use_hierarchy;
KAMEZAWA Hiroyuki867578c2010-03-10 15:22:39 -0800229 atomic_t oom_lock;
KAMEZAWA Hiroyuki8c7c6e342009-01-07 18:08:00 -0800230 atomic_t refcnt;
KOSAKI Motohiro14797e22009-01-07 18:08:18 -0800231
KOSAKI Motohiroa7885eb2009-01-07 18:08:24 -0800232 unsigned int swappiness;
KAMEZAWA Hiroyuki3c11ecf2010-05-26 14:42:37 -0700233 /* OOM-Killer disable */
234 int oom_kill_disable;
KOSAKI Motohiroa7885eb2009-01-07 18:08:24 -0800235
KAMEZAWA Hiroyuki22a668d2009-06-17 16:27:19 -0700236 /* set when res.limit == memsw.limit */
237 bool memsw_is_minimum;
238
Kirill A. Shutemov2e72b632010-03-10 15:22:24 -0800239 /* protect arrays of thresholds */
240 struct mutex thresholds_lock;
241
242 /* thresholds for memory usage. RCU-protected */
Kirill A. Shutemov2c488db2010-05-26 14:42:47 -0700243 struct mem_cgroup_thresholds thresholds;
Kirill A. Shutemov907860e2010-05-26 14:42:46 -0700244
Kirill A. Shutemov2e72b632010-03-10 15:22:24 -0800245 /* thresholds for mem+swap usage. RCU-protected */
Kirill A. Shutemov2c488db2010-05-26 14:42:47 -0700246 struct mem_cgroup_thresholds memsw_thresholds;
Kirill A. Shutemov907860e2010-05-26 14:42:46 -0700247
KAMEZAWA Hiroyuki9490ff22010-05-26 14:42:36 -0700248 /* For oom notifier event fd */
249 struct list_head oom_notify;
250
KAMEZAWA Hiroyukid52aa412008-02-07 00:14:24 -0800251 /*
Daisuke Nishimura7dc74be2010-03-10 15:22:13 -0800252 * Should we move charges of a task when a task is moved into this
253 * mem_cgroup ? And what type of charges should we move ?
254 */
255 unsigned long move_charge_at_immigrate;
Daisuke Nishimura7dc74be2010-03-10 15:22:13 -0800256 /*
KAMEZAWA Hiroyukic62b1a32010-03-10 15:22:29 -0800257 * percpu counter.
KAMEZAWA Hiroyukid52aa412008-02-07 00:14:24 -0800258 */
KAMEZAWA Hiroyukic62b1a32010-03-10 15:22:29 -0800259 struct mem_cgroup_stat_cpu *stat;
KAMEZAWA Hiroyuki711d3d22010-10-27 15:33:42 -0700260 /*
261 * used when a cpu is offlined or other synchronizations
262 * See mem_cgroup_read_stat().
263 */
264 struct mem_cgroup_stat_cpu nocpu_base;
265 spinlock_t pcp_counter_lock;
Balbir Singh8cdea7c2008-02-07 00:13:50 -0800266};
267
Daisuke Nishimura7dc74be2010-03-10 15:22:13 -0800268/* Stuffs for move charges at task migration. */
269/*
270 * Types of charges to be moved. "move_charge_at_immitgrate" is treated as a
271 * left-shifted bitmap of these types.
272 */
273enum move_type {
Daisuke Nishimura4ffef5f2010-03-10 15:22:14 -0800274 MOVE_CHARGE_TYPE_ANON, /* private anonymous page and swap of it */
Daisuke Nishimura87946a72010-05-26 14:42:39 -0700275 MOVE_CHARGE_TYPE_FILE, /* file page(including tmpfs) and swap of it */
Daisuke Nishimura7dc74be2010-03-10 15:22:13 -0800276 NR_MOVE_TYPE,
277};
278
Daisuke Nishimura4ffef5f2010-03-10 15:22:14 -0800279/* "mc" and its members are protected by cgroup_mutex */
280static struct move_charge_struct {
KAMEZAWA Hiroyuki2bd9bb22010-08-10 18:02:58 -0700281 spinlock_t lock; /* for from, to, moving_task */
Daisuke Nishimura4ffef5f2010-03-10 15:22:14 -0800282 struct mem_cgroup *from;
283 struct mem_cgroup *to;
284 unsigned long precharge;
Daisuke Nishimura854ffa82010-03-10 15:22:15 -0800285 unsigned long moved_charge;
Daisuke Nishimura483c30b2010-03-10 15:22:18 -0800286 unsigned long moved_swap;
Daisuke Nishimura8033b972010-03-10 15:22:16 -0800287 struct task_struct *moving_task; /* a task moving charges */
288 wait_queue_head_t waitq; /* a waitq for other context */
289} mc = {
KAMEZAWA Hiroyuki2bd9bb22010-08-10 18:02:58 -0700290 .lock = __SPIN_LOCK_UNLOCKED(mc.lock),
Daisuke Nishimura8033b972010-03-10 15:22:16 -0800291 .waitq = __WAIT_QUEUE_HEAD_INITIALIZER(mc.waitq),
292};
Daisuke Nishimura4ffef5f2010-03-10 15:22:14 -0800293
Daisuke Nishimura90254a62010-05-26 14:42:38 -0700294static bool move_anon(void)
295{
296 return test_bit(MOVE_CHARGE_TYPE_ANON,
297 &mc.to->move_charge_at_immigrate);
298}
299
Daisuke Nishimura87946a72010-05-26 14:42:39 -0700300static bool move_file(void)
301{
302 return test_bit(MOVE_CHARGE_TYPE_FILE,
303 &mc.to->move_charge_at_immigrate);
304}
305
Balbir Singh4e416952009-09-23 15:56:39 -0700306/*
307 * Maximum loops in mem_cgroup_hierarchical_reclaim(), used for soft
308 * limit reclaim to prevent infinite loops, if they ever occur.
309 */
310#define MEM_CGROUP_MAX_RECLAIM_LOOPS (100)
311#define MEM_CGROUP_MAX_SOFT_LIMIT_RECLAIM_LOOPS (2)
312
KAMEZAWA Hiroyuki217bc312008-02-07 00:14:17 -0800313enum charge_type {
314 MEM_CGROUP_CHARGE_TYPE_CACHE = 0,
315 MEM_CGROUP_CHARGE_TYPE_MAPPED,
Rik van Riel4f98a2f2008-10-18 20:26:32 -0700316 MEM_CGROUP_CHARGE_TYPE_SHMEM, /* used by page migration of shmem */
KAMEZAWA Hiroyukic05555b2008-10-18 20:28:11 -0700317 MEM_CGROUP_CHARGE_TYPE_FORCE, /* used by force_empty */
KAMEZAWA Hiroyukid13d1442009-01-07 18:07:56 -0800318 MEM_CGROUP_CHARGE_TYPE_SWAPOUT, /* for accounting swapcache */
KAMEZAWA Hiroyuki8a9478c2009-06-17 16:27:17 -0700319 MEM_CGROUP_CHARGE_TYPE_DROP, /* a page was unused swap cache */
KAMEZAWA Hiroyukic05555b2008-10-18 20:28:11 -0700320 NR_CHARGE_TYPE,
321};
322
KAMEZAWA Hiroyuki52d4b9a2008-10-18 20:28:16 -0700323/* only for here (for easy reading.) */
324#define PCGF_CACHE (1UL << PCG_CACHE)
325#define PCGF_USED (1UL << PCG_USED)
KAMEZAWA Hiroyuki52d4b9a2008-10-18 20:28:16 -0700326#define PCGF_LOCK (1UL << PCG_LOCK)
Balbir Singh4b3bde42009-09-23 15:56:32 -0700327/* Not used, but added here for completeness */
328#define PCGF_ACCT (1UL << PCG_ACCT)
KAMEZAWA Hiroyuki217bc312008-02-07 00:14:17 -0800329
KAMEZAWA Hiroyuki8c7c6e342009-01-07 18:08:00 -0800330/* for encoding cft->private value on file */
331#define _MEM (0)
332#define _MEMSWAP (1)
KAMEZAWA Hiroyuki9490ff22010-05-26 14:42:36 -0700333#define _OOM_TYPE (2)
KAMEZAWA Hiroyuki8c7c6e342009-01-07 18:08:00 -0800334#define MEMFILE_PRIVATE(x, val) (((x) << 16) | (val))
335#define MEMFILE_TYPE(val) (((val) >> 16) & 0xffff)
336#define MEMFILE_ATTR(val) ((val) & 0xffff)
KAMEZAWA Hiroyuki9490ff22010-05-26 14:42:36 -0700337/* Used for OOM nofiier */
338#define OOM_CONTROL (0)
KAMEZAWA Hiroyuki8c7c6e342009-01-07 18:08:00 -0800339
Balbir Singh75822b42009-09-23 15:56:38 -0700340/*
341 * Reclaim flags for mem_cgroup_hierarchical_reclaim
342 */
343#define MEM_CGROUP_RECLAIM_NOSWAP_BIT 0x0
344#define MEM_CGROUP_RECLAIM_NOSWAP (1 << MEM_CGROUP_RECLAIM_NOSWAP_BIT)
345#define MEM_CGROUP_RECLAIM_SHRINK_BIT 0x1
346#define MEM_CGROUP_RECLAIM_SHRINK (1 << MEM_CGROUP_RECLAIM_SHRINK_BIT)
Balbir Singh4e416952009-09-23 15:56:39 -0700347#define MEM_CGROUP_RECLAIM_SOFT_BIT 0x2
348#define MEM_CGROUP_RECLAIM_SOFT (1 << MEM_CGROUP_RECLAIM_SOFT_BIT)
Balbir Singh75822b42009-09-23 15:56:38 -0700349
KAMEZAWA Hiroyuki8c7c6e342009-01-07 18:08:00 -0800350static void mem_cgroup_get(struct mem_cgroup *mem);
351static void mem_cgroup_put(struct mem_cgroup *mem);
Daisuke Nishimura7bcc1bb2009-01-29 14:25:11 -0800352static struct mem_cgroup *parent_mem_cgroup(struct mem_cgroup *mem);
KAMEZAWA Hiroyukicdec2e42009-12-15 16:47:08 -0800353static void drain_all_stock_async(void);
KAMEZAWA Hiroyuki8c7c6e342009-01-07 18:08:00 -0800354
Balbir Singhf64c3f52009-09-23 15:56:37 -0700355static struct mem_cgroup_per_zone *
356mem_cgroup_zoneinfo(struct mem_cgroup *mem, int nid, int zid)
357{
358 return &mem->info.nodeinfo[nid]->zoneinfo[zid];
359}
360
Wu Fengguangd3242362009-12-16 12:19:59 +0100361struct cgroup_subsys_state *mem_cgroup_css(struct mem_cgroup *mem)
362{
363 return &mem->css;
364}
365
Balbir Singhf64c3f52009-09-23 15:56:37 -0700366static struct mem_cgroup_per_zone *
367page_cgroup_zoneinfo(struct page_cgroup *pc)
368{
369 struct mem_cgroup *mem = pc->mem_cgroup;
370 int nid = page_cgroup_nid(pc);
371 int zid = page_cgroup_zid(pc);
372
373 if (!mem)
374 return NULL;
375
376 return mem_cgroup_zoneinfo(mem, nid, zid);
377}
378
379static struct mem_cgroup_tree_per_zone *
380soft_limit_tree_node_zone(int nid, int zid)
381{
382 return &soft_limit_tree.rb_tree_per_node[nid]->rb_tree_per_zone[zid];
383}
384
385static struct mem_cgroup_tree_per_zone *
386soft_limit_tree_from_page(struct page *page)
387{
388 int nid = page_to_nid(page);
389 int zid = page_zonenum(page);
390
391 return &soft_limit_tree.rb_tree_per_node[nid]->rb_tree_per_zone[zid];
392}
393
394static void
Balbir Singh4e416952009-09-23 15:56:39 -0700395__mem_cgroup_insert_exceeded(struct mem_cgroup *mem,
Balbir Singhf64c3f52009-09-23 15:56:37 -0700396 struct mem_cgroup_per_zone *mz,
KAMEZAWA Hiroyukief8745c2009-10-01 15:44:12 -0700397 struct mem_cgroup_tree_per_zone *mctz,
398 unsigned long long new_usage_in_excess)
Balbir Singhf64c3f52009-09-23 15:56:37 -0700399{
400 struct rb_node **p = &mctz->rb_root.rb_node;
401 struct rb_node *parent = NULL;
402 struct mem_cgroup_per_zone *mz_node;
403
404 if (mz->on_tree)
405 return;
406
KAMEZAWA Hiroyukief8745c2009-10-01 15:44:12 -0700407 mz->usage_in_excess = new_usage_in_excess;
408 if (!mz->usage_in_excess)
409 return;
Balbir Singhf64c3f52009-09-23 15:56:37 -0700410 while (*p) {
411 parent = *p;
412 mz_node = rb_entry(parent, struct mem_cgroup_per_zone,
413 tree_node);
414 if (mz->usage_in_excess < mz_node->usage_in_excess)
415 p = &(*p)->rb_left;
416 /*
417 * We can't avoid mem cgroups that are over their soft
418 * limit by the same amount
419 */
420 else if (mz->usage_in_excess >= mz_node->usage_in_excess)
421 p = &(*p)->rb_right;
422 }
423 rb_link_node(&mz->tree_node, parent, p);
424 rb_insert_color(&mz->tree_node, &mctz->rb_root);
425 mz->on_tree = true;
Balbir Singh4e416952009-09-23 15:56:39 -0700426}
427
428static void
429__mem_cgroup_remove_exceeded(struct mem_cgroup *mem,
430 struct mem_cgroup_per_zone *mz,
431 struct mem_cgroup_tree_per_zone *mctz)
432{
433 if (!mz->on_tree)
434 return;
435 rb_erase(&mz->tree_node, &mctz->rb_root);
436 mz->on_tree = false;
437}
438
439static void
Balbir Singhf64c3f52009-09-23 15:56:37 -0700440mem_cgroup_remove_exceeded(struct mem_cgroup *mem,
441 struct mem_cgroup_per_zone *mz,
442 struct mem_cgroup_tree_per_zone *mctz)
443{
444 spin_lock(&mctz->lock);
Balbir Singh4e416952009-09-23 15:56:39 -0700445 __mem_cgroup_remove_exceeded(mem, mz, mctz);
Balbir Singhf64c3f52009-09-23 15:56:37 -0700446 spin_unlock(&mctz->lock);
447}
448
Balbir Singhf64c3f52009-09-23 15:56:37 -0700449
450static void mem_cgroup_update_tree(struct mem_cgroup *mem, struct page *page)
451{
KAMEZAWA Hiroyukief8745c2009-10-01 15:44:12 -0700452 unsigned long long excess;
Balbir Singhf64c3f52009-09-23 15:56:37 -0700453 struct mem_cgroup_per_zone *mz;
454 struct mem_cgroup_tree_per_zone *mctz;
KAMEZAWA Hiroyuki4e649152009-10-01 15:44:11 -0700455 int nid = page_to_nid(page);
456 int zid = page_zonenum(page);
Balbir Singhf64c3f52009-09-23 15:56:37 -0700457 mctz = soft_limit_tree_from_page(page);
458
459 /*
KAMEZAWA Hiroyuki4e649152009-10-01 15:44:11 -0700460 * Necessary to update all ancestors when hierarchy is used.
461 * because their event counter is not touched.
Balbir Singhf64c3f52009-09-23 15:56:37 -0700462 */
KAMEZAWA Hiroyuki4e649152009-10-01 15:44:11 -0700463 for (; mem; mem = parent_mem_cgroup(mem)) {
464 mz = mem_cgroup_zoneinfo(mem, nid, zid);
KAMEZAWA Hiroyukief8745c2009-10-01 15:44:12 -0700465 excess = res_counter_soft_limit_excess(&mem->res);
KAMEZAWA Hiroyuki4e649152009-10-01 15:44:11 -0700466 /*
467 * We have to update the tree if mz is on RB-tree or
468 * mem is over its softlimit.
469 */
KAMEZAWA Hiroyukief8745c2009-10-01 15:44:12 -0700470 if (excess || mz->on_tree) {
KAMEZAWA Hiroyuki4e649152009-10-01 15:44:11 -0700471 spin_lock(&mctz->lock);
472 /* if on-tree, remove it */
473 if (mz->on_tree)
474 __mem_cgroup_remove_exceeded(mem, mz, mctz);
475 /*
KAMEZAWA Hiroyukief8745c2009-10-01 15:44:12 -0700476 * Insert again. mz->usage_in_excess will be updated.
477 * If excess is 0, no tree ops.
KAMEZAWA Hiroyuki4e649152009-10-01 15:44:11 -0700478 */
KAMEZAWA Hiroyukief8745c2009-10-01 15:44:12 -0700479 __mem_cgroup_insert_exceeded(mem, mz, mctz, excess);
KAMEZAWA Hiroyuki4e649152009-10-01 15:44:11 -0700480 spin_unlock(&mctz->lock);
481 }
Balbir Singhf64c3f52009-09-23 15:56:37 -0700482 }
483}
484
485static void mem_cgroup_remove_from_trees(struct mem_cgroup *mem)
486{
487 int node, zone;
488 struct mem_cgroup_per_zone *mz;
489 struct mem_cgroup_tree_per_zone *mctz;
490
491 for_each_node_state(node, N_POSSIBLE) {
492 for (zone = 0; zone < MAX_NR_ZONES; zone++) {
493 mz = mem_cgroup_zoneinfo(mem, node, zone);
494 mctz = soft_limit_tree_node_zone(node, zone);
495 mem_cgroup_remove_exceeded(mem, mz, mctz);
496 }
497 }
498}
499
Balbir Singh4e416952009-09-23 15:56:39 -0700500static inline unsigned long mem_cgroup_get_excess(struct mem_cgroup *mem)
501{
502 return res_counter_soft_limit_excess(&mem->res) >> PAGE_SHIFT;
503}
504
505static struct mem_cgroup_per_zone *
506__mem_cgroup_largest_soft_limit_node(struct mem_cgroup_tree_per_zone *mctz)
507{
508 struct rb_node *rightmost = NULL;
KAMEZAWA Hiroyuki26251ea2009-10-01 15:44:08 -0700509 struct mem_cgroup_per_zone *mz;
Balbir Singh4e416952009-09-23 15:56:39 -0700510
511retry:
KAMEZAWA Hiroyuki26251ea2009-10-01 15:44:08 -0700512 mz = NULL;
Balbir Singh4e416952009-09-23 15:56:39 -0700513 rightmost = rb_last(&mctz->rb_root);
514 if (!rightmost)
515 goto done; /* Nothing to reclaim from */
516
517 mz = rb_entry(rightmost, struct mem_cgroup_per_zone, tree_node);
518 /*
519 * Remove the node now but someone else can add it back,
520 * we will to add it back at the end of reclaim to its correct
521 * position in the tree.
522 */
523 __mem_cgroup_remove_exceeded(mz->mem, mz, mctz);
524 if (!res_counter_soft_limit_excess(&mz->mem->res) ||
525 !css_tryget(&mz->mem->css))
526 goto retry;
527done:
528 return mz;
529}
530
531static struct mem_cgroup_per_zone *
532mem_cgroup_largest_soft_limit_node(struct mem_cgroup_tree_per_zone *mctz)
533{
534 struct mem_cgroup_per_zone *mz;
535
536 spin_lock(&mctz->lock);
537 mz = __mem_cgroup_largest_soft_limit_node(mctz);
538 spin_unlock(&mctz->lock);
539 return mz;
540}
541
KAMEZAWA Hiroyuki711d3d22010-10-27 15:33:42 -0700542/*
543 * Implementation Note: reading percpu statistics for memcg.
544 *
545 * Both of vmstat[] and percpu_counter has threshold and do periodic
546 * synchronization to implement "quick" read. There are trade-off between
547 * reading cost and precision of value. Then, we may have a chance to implement
548 * a periodic synchronizion of counter in memcg's counter.
549 *
550 * But this _read() function is used for user interface now. The user accounts
551 * memory usage by memory cgroup and he _always_ requires exact value because
552 * he accounts memory. Even if we provide quick-and-fuzzy read, we always
553 * have to visit all online cpus and make sum. So, for now, unnecessary
554 * synchronization is not implemented. (just implemented for cpu hotplug)
555 *
556 * If there are kernel internal actions which can make use of some not-exact
557 * value, and reading all cpu value can be performance bottleneck in some
558 * common workload, threashold and synchonization as vmstat[] should be
559 * implemented.
560 */
KAMEZAWA Hiroyukic62b1a32010-03-10 15:22:29 -0800561static s64 mem_cgroup_read_stat(struct mem_cgroup *mem,
562 enum mem_cgroup_stat_index idx)
563{
564 int cpu;
565 s64 val = 0;
566
KAMEZAWA Hiroyuki711d3d22010-10-27 15:33:42 -0700567 get_online_cpus();
568 for_each_online_cpu(cpu)
KAMEZAWA Hiroyukic62b1a32010-03-10 15:22:29 -0800569 val += per_cpu(mem->stat->count[idx], cpu);
KAMEZAWA Hiroyuki711d3d22010-10-27 15:33:42 -0700570#ifdef CONFIG_HOTPLUG_CPU
571 spin_lock(&mem->pcp_counter_lock);
572 val += mem->nocpu_base.count[idx];
573 spin_unlock(&mem->pcp_counter_lock);
574#endif
575 put_online_cpus();
KAMEZAWA Hiroyukic62b1a32010-03-10 15:22:29 -0800576 return val;
577}
578
579static s64 mem_cgroup_local_usage(struct mem_cgroup *mem)
580{
581 s64 ret;
582
583 ret = mem_cgroup_read_stat(mem, MEM_CGROUP_STAT_RSS);
584 ret += mem_cgroup_read_stat(mem, MEM_CGROUP_STAT_CACHE);
585 return ret;
586}
587
Balbir Singh0c3e73e2009-09-23 15:56:42 -0700588static void mem_cgroup_swap_statistics(struct mem_cgroup *mem,
589 bool charge)
590{
591 int val = (charge) ? 1 : -1;
KAMEZAWA Hiroyukic62b1a32010-03-10 15:22:29 -0800592 this_cpu_add(mem->stat->count[MEM_CGROUP_STAT_SWAPOUT], val);
Balbir Singh0c3e73e2009-09-23 15:56:42 -0700593}
594
KAMEZAWA Hiroyukic05555b2008-10-18 20:28:11 -0700595static void mem_cgroup_charge_statistics(struct mem_cgroup *mem,
596 struct page_cgroup *pc,
597 bool charge)
KAMEZAWA Hiroyukid52aa412008-02-07 00:14:24 -0800598{
Balbir Singh0c3e73e2009-09-23 15:56:42 -0700599 int val = (charge) ? 1 : -1;
KAMEZAWA Hiroyukid52aa412008-02-07 00:14:24 -0800600
KAMEZAWA Hiroyukic62b1a32010-03-10 15:22:29 -0800601 preempt_disable();
602
KAMEZAWA Hiroyukic05555b2008-10-18 20:28:11 -0700603 if (PageCgroupCache(pc))
KAMEZAWA Hiroyukic62b1a32010-03-10 15:22:29 -0800604 __this_cpu_add(mem->stat->count[MEM_CGROUP_STAT_CACHE], val);
KAMEZAWA Hiroyukid52aa412008-02-07 00:14:24 -0800605 else
KAMEZAWA Hiroyukic62b1a32010-03-10 15:22:29 -0800606 __this_cpu_add(mem->stat->count[MEM_CGROUP_STAT_RSS], val);
Balaji Rao55e462b2008-05-01 04:35:12 -0700607
608 if (charge)
KAMEZAWA Hiroyukic62b1a32010-03-10 15:22:29 -0800609 __this_cpu_inc(mem->stat->count[MEM_CGROUP_STAT_PGPGIN_COUNT]);
Balaji Rao55e462b2008-05-01 04:35:12 -0700610 else
KAMEZAWA Hiroyukic62b1a32010-03-10 15:22:29 -0800611 __this_cpu_inc(mem->stat->count[MEM_CGROUP_STAT_PGPGOUT_COUNT]);
KAMEZAWA Hiroyukid2265e62010-03-10 15:22:31 -0800612 __this_cpu_inc(mem->stat->count[MEM_CGROUP_EVENTS]);
Kirill A. Shutemov2e72b632010-03-10 15:22:24 -0800613
KAMEZAWA Hiroyukic62b1a32010-03-10 15:22:29 -0800614 preempt_enable();
KAMEZAWA Hiroyuki6d12e2d2008-02-07 00:14:31 -0800615}
KAMEZAWA Hiroyukid52aa412008-02-07 00:14:24 -0800616
KAMEZAWA Hiroyuki14067bb2009-04-02 16:57:35 -0700617static unsigned long mem_cgroup_get_local_zonestat(struct mem_cgroup *mem,
Christoph Lameterb69408e2008-10-18 20:26:14 -0700618 enum lru_list idx)
KAMEZAWA Hiroyuki6d12e2d2008-02-07 00:14:31 -0800619{
620 int nid, zid;
621 struct mem_cgroup_per_zone *mz;
622 u64 total = 0;
623
624 for_each_online_node(nid)
625 for (zid = 0; zid < MAX_NR_ZONES; zid++) {
626 mz = mem_cgroup_zoneinfo(mem, nid, zid);
627 total += MEM_CGROUP_ZSTAT(mz, idx);
628 }
629 return total;
KAMEZAWA Hiroyukid52aa412008-02-07 00:14:24 -0800630}
631
KAMEZAWA Hiroyukid2265e62010-03-10 15:22:31 -0800632static bool __memcg_event_check(struct mem_cgroup *mem, int event_mask_shift)
633{
634 s64 val;
635
636 val = this_cpu_read(mem->stat->count[MEM_CGROUP_EVENTS]);
637
638 return !(val & ((1 << event_mask_shift) - 1));
639}
640
641/*
642 * Check events in order.
643 *
644 */
645static void memcg_check_events(struct mem_cgroup *mem, struct page *page)
646{
647 /* threshold event is triggered in finer grain than soft limit */
648 if (unlikely(__memcg_event_check(mem, THRESHOLDS_EVENTS_THRESH))) {
649 mem_cgroup_threshold(mem);
650 if (unlikely(__memcg_event_check(mem, SOFTLIMIT_EVENTS_THRESH)))
651 mem_cgroup_update_tree(mem, page);
652 }
653}
654
Hugh Dickinsd5b69e32008-03-04 14:29:10 -0800655static struct mem_cgroup *mem_cgroup_from_cont(struct cgroup *cont)
Balbir Singh8cdea7c2008-02-07 00:13:50 -0800656{
657 return container_of(cgroup_subsys_state(cont,
658 mem_cgroup_subsys_id), struct mem_cgroup,
659 css);
660}
661
Balbir Singhcf475ad2008-04-29 01:00:16 -0700662struct mem_cgroup *mem_cgroup_from_task(struct task_struct *p)
Pavel Emelianov78fb7462008-02-07 00:13:51 -0800663{
Balbir Singh31a78f22008-09-28 23:09:31 +0100664 /*
665 * mm_update_next_owner() may clear mm->owner to NULL
666 * if it races with swapoff, page migration, etc.
667 * So this can be called with p == NULL.
668 */
669 if (unlikely(!p))
670 return NULL;
671
Pavel Emelianov78fb7462008-02-07 00:13:51 -0800672 return container_of(task_subsys_state(p, mem_cgroup_subsys_id),
673 struct mem_cgroup, css);
674}
675
KAMEZAWA Hiroyuki54595fe2009-01-07 18:08:33 -0800676static struct mem_cgroup *try_get_mem_cgroup_from_mm(struct mm_struct *mm)
677{
678 struct mem_cgroup *mem = NULL;
KAMEZAWA Hiroyuki0b7f5692009-04-02 16:57:38 -0700679
680 if (!mm)
681 return NULL;
KAMEZAWA Hiroyuki54595fe2009-01-07 18:08:33 -0800682 /*
683 * Because we have no locks, mm->owner's may be being moved to other
684 * cgroup. We use css_tryget() here even if this looks
685 * pessimistic (rather than adding locks here).
686 */
687 rcu_read_lock();
688 do {
689 mem = mem_cgroup_from_task(rcu_dereference(mm->owner));
690 if (unlikely(!mem))
691 break;
692 } while (!css_tryget(&mem->css));
693 rcu_read_unlock();
694 return mem;
695}
696
KAMEZAWA Hiroyuki7d74b062010-10-27 15:33:41 -0700697/* The caller has to guarantee "mem" exists before calling this */
698static struct mem_cgroup *mem_cgroup_start_loop(struct mem_cgroup *mem)
KAMEZAWA Hiroyuki14067bb2009-04-02 16:57:35 -0700699{
KAMEZAWA Hiroyuki711d3d22010-10-27 15:33:42 -0700700 struct cgroup_subsys_state *css;
701 int found;
702
703 if (!mem) /* ROOT cgroup has the smallest ID */
704 return root_mem_cgroup; /*css_put/get against root is ignored*/
705 if (!mem->use_hierarchy) {
706 if (css_tryget(&mem->css))
707 return mem;
708 return NULL;
709 }
710 rcu_read_lock();
711 /*
712 * searching a memory cgroup which has the smallest ID under given
713 * ROOT cgroup. (ID >= 1)
714 */
715 css = css_get_next(&mem_cgroup_subsys, 1, &mem->css, &found);
716 if (css && css_tryget(css))
717 mem = container_of(css, struct mem_cgroup, css);
718 else
719 mem = NULL;
720 rcu_read_unlock();
721 return mem;
KAMEZAWA Hiroyuki14067bb2009-04-02 16:57:35 -0700722}
723
KAMEZAWA Hiroyuki7d74b062010-10-27 15:33:41 -0700724static struct mem_cgroup *mem_cgroup_get_next(struct mem_cgroup *iter,
725 struct mem_cgroup *root,
726 bool cond)
727{
728 int nextid = css_id(&iter->css) + 1;
729 int found;
730 int hierarchy_used;
731 struct cgroup_subsys_state *css;
732
733 hierarchy_used = iter->use_hierarchy;
734
735 css_put(&iter->css);
KAMEZAWA Hiroyuki711d3d22010-10-27 15:33:42 -0700736 /* If no ROOT, walk all, ignore hierarchy */
737 if (!cond || (root && !hierarchy_used))
KAMEZAWA Hiroyuki7d74b062010-10-27 15:33:41 -0700738 return NULL;
739
KAMEZAWA Hiroyuki711d3d22010-10-27 15:33:42 -0700740 if (!root)
741 root = root_mem_cgroup;
742
KAMEZAWA Hiroyuki7d74b062010-10-27 15:33:41 -0700743 do {
744 iter = NULL;
745 rcu_read_lock();
746
747 css = css_get_next(&mem_cgroup_subsys, nextid,
748 &root->css, &found);
749 if (css && css_tryget(css))
750 iter = container_of(css, struct mem_cgroup, css);
751 rcu_read_unlock();
752 /* If css is NULL, no more cgroups will be found */
753 nextid = found + 1;
754 } while (css && !iter);
755
756 return iter;
757}
758/*
759 * for_eacn_mem_cgroup_tree() for visiting all cgroup under tree. Please
760 * be careful that "break" loop is not allowed. We have reference count.
761 * Instead of that modify "cond" to be false and "continue" to exit the loop.
762 */
763#define for_each_mem_cgroup_tree_cond(iter, root, cond) \
764 for (iter = mem_cgroup_start_loop(root);\
765 iter != NULL;\
766 iter = mem_cgroup_get_next(iter, root, cond))
767
768#define for_each_mem_cgroup_tree(iter, root) \
769 for_each_mem_cgroup_tree_cond(iter, root, true)
770
KAMEZAWA Hiroyuki711d3d22010-10-27 15:33:42 -0700771#define for_each_mem_cgroup_all(iter) \
772 for_each_mem_cgroup_tree_cond(iter, NULL, true)
773
KAMEZAWA Hiroyuki7d74b062010-10-27 15:33:41 -0700774
Balbir Singh4b3bde42009-09-23 15:56:32 -0700775static inline bool mem_cgroup_is_root(struct mem_cgroup *mem)
776{
777 return (mem == root_mem_cgroup);
778}
779
KAMEZAWA Hiroyuki08e552c2009-01-07 18:08:01 -0800780/*
781 * Following LRU functions are allowed to be used without PCG_LOCK.
782 * Operations are called by routine of global LRU independently from memcg.
783 * What we have to take care of here is validness of pc->mem_cgroup.
784 *
785 * Changes to pc->mem_cgroup happens when
786 * 1. charge
787 * 2. moving account
788 * In typical case, "charge" is done before add-to-lru. Exception is SwapCache.
789 * It is added to LRU before charge.
790 * If PCG_USED bit is not set, page_cgroup is not added to this private LRU.
791 * When moving account, the page is not on LRU. It's isolated.
792 */
793
794void mem_cgroup_del_lru_list(struct page *page, enum lru_list lru)
KAMEZAWA Hiroyuki6d12e2d2008-02-07 00:14:31 -0800795{
KAMEZAWA Hiroyuki08e552c2009-01-07 18:08:01 -0800796 struct page_cgroup *pc;
KAMEZAWA Hiroyuki08e552c2009-01-07 18:08:01 -0800797 struct mem_cgroup_per_zone *mz;
Rik van Riel4f98a2f2008-10-18 20:26:32 -0700798
Hirokazu Takahashif8d665422009-01-07 18:08:02 -0800799 if (mem_cgroup_disabled())
KAMEZAWA Hiroyuki08e552c2009-01-07 18:08:01 -0800800 return;
801 pc = lookup_page_cgroup(page);
802 /* can happen while we handle swapcache. */
Balbir Singh4b3bde42009-09-23 15:56:32 -0700803 if (!TestClearPageCgroupAcctLRU(pc))
KAMEZAWA Hiroyuki08e552c2009-01-07 18:08:01 -0800804 return;
Balbir Singh4b3bde42009-09-23 15:56:32 -0700805 VM_BUG_ON(!pc->mem_cgroup);
KAMEZAWA Hiroyuki544122e2009-01-07 18:08:34 -0800806 /*
807 * We don't check PCG_USED bit. It's cleared when the "page" is finally
808 * removed from global LRU.
809 */
KAMEZAWA Hiroyuki08e552c2009-01-07 18:08:01 -0800810 mz = page_cgroup_zoneinfo(pc);
Christoph Lameterb69408e2008-10-18 20:26:14 -0700811 MEM_CGROUP_ZSTAT(mz, lru) -= 1;
Balbir Singh4b3bde42009-09-23 15:56:32 -0700812 if (mem_cgroup_is_root(pc->mem_cgroup))
813 return;
814 VM_BUG_ON(list_empty(&pc->lru));
KAMEZAWA Hiroyuki08e552c2009-01-07 18:08:01 -0800815 list_del_init(&pc->lru);
816 return;
KAMEZAWA Hiroyuki6d12e2d2008-02-07 00:14:31 -0800817}
818
KAMEZAWA Hiroyuki08e552c2009-01-07 18:08:01 -0800819void mem_cgroup_del_lru(struct page *page)
KAMEZAWA Hiroyuki6d12e2d2008-02-07 00:14:31 -0800820{
KAMEZAWA Hiroyuki08e552c2009-01-07 18:08:01 -0800821 mem_cgroup_del_lru_list(page, page_lru(page));
KAMEZAWA Hiroyuki6d12e2d2008-02-07 00:14:31 -0800822}
823
KAMEZAWA Hiroyuki08e552c2009-01-07 18:08:01 -0800824void mem_cgroup_rotate_lru_list(struct page *page, enum lru_list lru)
Balbir Singh66e17072008-02-07 00:13:56 -0800825{
KAMEZAWA Hiroyuki08e552c2009-01-07 18:08:01 -0800826 struct mem_cgroup_per_zone *mz;
827 struct page_cgroup *pc;
KAMEZAWA Hiroyuki6d12e2d2008-02-07 00:14:31 -0800828
Hirokazu Takahashif8d665422009-01-07 18:08:02 -0800829 if (mem_cgroup_disabled())
Lee Schermerhorn894bc312008-10-18 20:26:39 -0700830 return;
Christoph Lameterb69408e2008-10-18 20:26:14 -0700831
KAMEZAWA Hiroyuki08e552c2009-01-07 18:08:01 -0800832 pc = lookup_page_cgroup(page);
Daisuke Nishimurabd112db2009-01-15 13:51:11 -0800833 /*
834 * Used bit is set without atomic ops but after smp_wmb().
835 * For making pc->mem_cgroup visible, insert smp_rmb() here.
836 */
KAMEZAWA Hiroyuki08e552c2009-01-07 18:08:01 -0800837 smp_rmb();
Balbir Singh4b3bde42009-09-23 15:56:32 -0700838 /* unused or root page is not rotated. */
839 if (!PageCgroupUsed(pc) || mem_cgroup_is_root(pc->mem_cgroup))
KAMEZAWA Hiroyuki08e552c2009-01-07 18:08:01 -0800840 return;
841 mz = page_cgroup_zoneinfo(pc);
Christoph Lameterb69408e2008-10-18 20:26:14 -0700842 list_move(&pc->lru, &mz->lists[lru]);
Balbir Singh66e17072008-02-07 00:13:56 -0800843}
844
KAMEZAWA Hiroyuki08e552c2009-01-07 18:08:01 -0800845void mem_cgroup_add_lru_list(struct page *page, enum lru_list lru)
846{
847 struct page_cgroup *pc;
848 struct mem_cgroup_per_zone *mz;
849
Hirokazu Takahashif8d665422009-01-07 18:08:02 -0800850 if (mem_cgroup_disabled())
KAMEZAWA Hiroyuki08e552c2009-01-07 18:08:01 -0800851 return;
852 pc = lookup_page_cgroup(page);
Balbir Singh4b3bde42009-09-23 15:56:32 -0700853 VM_BUG_ON(PageCgroupAcctLRU(pc));
Daisuke Nishimurabd112db2009-01-15 13:51:11 -0800854 /*
855 * Used bit is set without atomic ops but after smp_wmb().
856 * For making pc->mem_cgroup visible, insert smp_rmb() here.
857 */
KAMEZAWA Hiroyuki08e552c2009-01-07 18:08:01 -0800858 smp_rmb();
859 if (!PageCgroupUsed(pc))
860 return;
861
862 mz = page_cgroup_zoneinfo(pc);
863 MEM_CGROUP_ZSTAT(mz, lru) += 1;
Balbir Singh4b3bde42009-09-23 15:56:32 -0700864 SetPageCgroupAcctLRU(pc);
865 if (mem_cgroup_is_root(pc->mem_cgroup))
866 return;
KAMEZAWA Hiroyuki08e552c2009-01-07 18:08:01 -0800867 list_add(&pc->lru, &mz->lists[lru]);
868}
KAMEZAWA Hiroyuki544122e2009-01-07 18:08:34 -0800869
KAMEZAWA Hiroyuki08e552c2009-01-07 18:08:01 -0800870/*
KAMEZAWA Hiroyuki544122e2009-01-07 18:08:34 -0800871 * At handling SwapCache, pc->mem_cgroup may be changed while it's linked to
872 * lru because the page may.be reused after it's fully uncharged (because of
873 * SwapCache behavior).To handle that, unlink page_cgroup from LRU when charge
874 * it again. This function is only used to charge SwapCache. It's done under
875 * lock_page and expected that zone->lru_lock is never held.
KAMEZAWA Hiroyuki08e552c2009-01-07 18:08:01 -0800876 */
KAMEZAWA Hiroyuki544122e2009-01-07 18:08:34 -0800877static void mem_cgroup_lru_del_before_commit_swapcache(struct page *page)
KAMEZAWA Hiroyuki08e552c2009-01-07 18:08:01 -0800878{
KAMEZAWA Hiroyuki544122e2009-01-07 18:08:34 -0800879 unsigned long flags;
880 struct zone *zone = page_zone(page);
881 struct page_cgroup *pc = lookup_page_cgroup(page);
882
883 spin_lock_irqsave(&zone->lru_lock, flags);
884 /*
885 * Forget old LRU when this page_cgroup is *not* used. This Used bit
886 * is guarded by lock_page() because the page is SwapCache.
887 */
888 if (!PageCgroupUsed(pc))
889 mem_cgroup_del_lru_list(page, page_lru(page));
890 spin_unlock_irqrestore(&zone->lru_lock, flags);
KAMEZAWA Hiroyuki08e552c2009-01-07 18:08:01 -0800891}
892
KAMEZAWA Hiroyuki544122e2009-01-07 18:08:34 -0800893static void mem_cgroup_lru_add_after_commit_swapcache(struct page *page)
894{
895 unsigned long flags;
896 struct zone *zone = page_zone(page);
897 struct page_cgroup *pc = lookup_page_cgroup(page);
898
899 spin_lock_irqsave(&zone->lru_lock, flags);
900 /* link when the page is linked to LRU but page_cgroup isn't */
Balbir Singh4b3bde42009-09-23 15:56:32 -0700901 if (PageLRU(page) && !PageCgroupAcctLRU(pc))
KAMEZAWA Hiroyuki544122e2009-01-07 18:08:34 -0800902 mem_cgroup_add_lru_list(page, page_lru(page));
903 spin_unlock_irqrestore(&zone->lru_lock, flags);
904}
905
906
KAMEZAWA Hiroyuki08e552c2009-01-07 18:08:01 -0800907void mem_cgroup_move_lists(struct page *page,
908 enum lru_list from, enum lru_list to)
909{
Hirokazu Takahashif8d665422009-01-07 18:08:02 -0800910 if (mem_cgroup_disabled())
KAMEZAWA Hiroyuki08e552c2009-01-07 18:08:01 -0800911 return;
912 mem_cgroup_del_lru_list(page, from);
913 mem_cgroup_add_lru_list(page, to);
914}
915
David Rientjes4c4a2212008-02-07 00:14:06 -0800916int task_in_mem_cgroup(struct task_struct *task, const struct mem_cgroup *mem)
917{
918 int ret;
KAMEZAWA Hiroyuki0b7f5692009-04-02 16:57:38 -0700919 struct mem_cgroup *curr = NULL;
KAMEZAWA Hiroyuki158e0a22010-08-10 18:03:00 -0700920 struct task_struct *p;
David Rientjes4c4a2212008-02-07 00:14:06 -0800921
KAMEZAWA Hiroyuki158e0a22010-08-10 18:03:00 -0700922 p = find_lock_task_mm(task);
923 if (!p)
924 return 0;
925 curr = try_get_mem_cgroup_from_mm(p->mm);
926 task_unlock(p);
KAMEZAWA Hiroyuki0b7f5692009-04-02 16:57:38 -0700927 if (!curr)
928 return 0;
Daisuke Nishimurad31f56d2009-12-15 16:47:12 -0800929 /*
930 * We should check use_hierarchy of "mem" not "curr". Because checking
931 * use_hierarchy of "curr" here make this function true if hierarchy is
932 * enabled in "curr" and "curr" is a child of "mem" in *cgroup*
933 * hierarchy(even if use_hierarchy is disabled in "mem").
934 */
935 if (mem->use_hierarchy)
KAMEZAWA Hiroyuki0b7f5692009-04-02 16:57:38 -0700936 ret = css_is_ancestor(&curr->css, &mem->css);
937 else
938 ret = (curr == mem);
939 css_put(&curr->css);
David Rientjes4c4a2212008-02-07 00:14:06 -0800940 return ret;
941}
942
KOSAKI Motohiroc772be92009-01-07 18:08:25 -0800943static int calc_inactive_ratio(struct mem_cgroup *memcg, unsigned long *present_pages)
KOSAKI Motohiro14797e22009-01-07 18:08:18 -0800944{
945 unsigned long active;
946 unsigned long inactive;
KOSAKI Motohiroc772be92009-01-07 18:08:25 -0800947 unsigned long gb;
948 unsigned long inactive_ratio;
KOSAKI Motohiro14797e22009-01-07 18:08:18 -0800949
KAMEZAWA Hiroyuki14067bb2009-04-02 16:57:35 -0700950 inactive = mem_cgroup_get_local_zonestat(memcg, LRU_INACTIVE_ANON);
951 active = mem_cgroup_get_local_zonestat(memcg, LRU_ACTIVE_ANON);
KOSAKI Motohiro14797e22009-01-07 18:08:18 -0800952
KOSAKI Motohiroc772be92009-01-07 18:08:25 -0800953 gb = (inactive + active) >> (30 - PAGE_SHIFT);
954 if (gb)
955 inactive_ratio = int_sqrt(10 * gb);
956 else
957 inactive_ratio = 1;
958
959 if (present_pages) {
960 present_pages[0] = inactive;
961 present_pages[1] = active;
962 }
963
964 return inactive_ratio;
965}
966
967int mem_cgroup_inactive_anon_is_low(struct mem_cgroup *memcg)
968{
969 unsigned long active;
970 unsigned long inactive;
971 unsigned long present_pages[2];
972 unsigned long inactive_ratio;
973
974 inactive_ratio = calc_inactive_ratio(memcg, present_pages);
975
976 inactive = present_pages[0];
977 active = present_pages[1];
978
979 if (inactive * inactive_ratio < active)
KOSAKI Motohiro14797e22009-01-07 18:08:18 -0800980 return 1;
981
982 return 0;
983}
984
Rik van Riel56e49d22009-06-16 15:32:28 -0700985int mem_cgroup_inactive_file_is_low(struct mem_cgroup *memcg)
986{
987 unsigned long active;
988 unsigned long inactive;
989
990 inactive = mem_cgroup_get_local_zonestat(memcg, LRU_INACTIVE_FILE);
991 active = mem_cgroup_get_local_zonestat(memcg, LRU_ACTIVE_FILE);
992
993 return (active > inactive);
994}
995
KOSAKI Motohiroa3d8e052009-01-07 18:08:19 -0800996unsigned long mem_cgroup_zone_nr_pages(struct mem_cgroup *memcg,
997 struct zone *zone,
998 enum lru_list lru)
999{
KOSAKI Motohiro13d7e3a2010-08-10 18:03:06 -07001000 int nid = zone_to_nid(zone);
KOSAKI Motohiroa3d8e052009-01-07 18:08:19 -08001001 int zid = zone_idx(zone);
1002 struct mem_cgroup_per_zone *mz = mem_cgroup_zoneinfo(memcg, nid, zid);
1003
1004 return MEM_CGROUP_ZSTAT(mz, lru);
1005}
1006
KOSAKI Motohiro3e2f41f2009-01-07 18:08:20 -08001007struct zone_reclaim_stat *mem_cgroup_get_reclaim_stat(struct mem_cgroup *memcg,
1008 struct zone *zone)
1009{
KOSAKI Motohiro13d7e3a2010-08-10 18:03:06 -07001010 int nid = zone_to_nid(zone);
KOSAKI Motohiro3e2f41f2009-01-07 18:08:20 -08001011 int zid = zone_idx(zone);
1012 struct mem_cgroup_per_zone *mz = mem_cgroup_zoneinfo(memcg, nid, zid);
1013
1014 return &mz->reclaim_stat;
1015}
1016
1017struct zone_reclaim_stat *
1018mem_cgroup_get_reclaim_stat_from_page(struct page *page)
1019{
1020 struct page_cgroup *pc;
1021 struct mem_cgroup_per_zone *mz;
1022
1023 if (mem_cgroup_disabled())
1024 return NULL;
1025
1026 pc = lookup_page_cgroup(page);
Daisuke Nishimurabd112db2009-01-15 13:51:11 -08001027 /*
1028 * Used bit is set without atomic ops but after smp_wmb().
1029 * For making pc->mem_cgroup visible, insert smp_rmb() here.
1030 */
1031 smp_rmb();
1032 if (!PageCgroupUsed(pc))
1033 return NULL;
1034
KOSAKI Motohiro3e2f41f2009-01-07 18:08:20 -08001035 mz = page_cgroup_zoneinfo(pc);
1036 if (!mz)
1037 return NULL;
1038
1039 return &mz->reclaim_stat;
1040}
1041
Balbir Singh66e17072008-02-07 00:13:56 -08001042unsigned long mem_cgroup_isolate_pages(unsigned long nr_to_scan,
1043 struct list_head *dst,
1044 unsigned long *scanned, int order,
1045 int mode, struct zone *z,
1046 struct mem_cgroup *mem_cont,
Rik van Riel4f98a2f2008-10-18 20:26:32 -07001047 int active, int file)
Balbir Singh66e17072008-02-07 00:13:56 -08001048{
1049 unsigned long nr_taken = 0;
1050 struct page *page;
1051 unsigned long scan;
1052 LIST_HEAD(pc_list);
1053 struct list_head *src;
KAMEZAWA Hiroyukiff7283f2008-02-07 00:14:11 -08001054 struct page_cgroup *pc, *tmp;
KOSAKI Motohiro13d7e3a2010-08-10 18:03:06 -07001055 int nid = zone_to_nid(z);
KAMEZAWA Hiroyuki1ecaab22008-02-07 00:14:38 -08001056 int zid = zone_idx(z);
1057 struct mem_cgroup_per_zone *mz;
Johannes Weinerb7c46d12009-09-21 17:02:56 -07001058 int lru = LRU_FILE * file + active;
KAMEZAWA Hiroyuki2ffebca2009-06-17 16:27:21 -07001059 int ret;
Balbir Singh66e17072008-02-07 00:13:56 -08001060
Balbir Singhcf475ad2008-04-29 01:00:16 -07001061 BUG_ON(!mem_cont);
KAMEZAWA Hiroyuki1ecaab22008-02-07 00:14:38 -08001062 mz = mem_cgroup_zoneinfo(mem_cont, nid, zid);
Christoph Lameterb69408e2008-10-18 20:26:14 -07001063 src = &mz->lists[lru];
Balbir Singh66e17072008-02-07 00:13:56 -08001064
KAMEZAWA Hiroyukiff7283f2008-02-07 00:14:11 -08001065 scan = 0;
1066 list_for_each_entry_safe_reverse(pc, tmp, src, lru) {
Hugh Dickins436c65412008-02-07 00:14:12 -08001067 if (scan >= nr_to_scan)
KAMEZAWA Hiroyukiff7283f2008-02-07 00:14:11 -08001068 break;
KAMEZAWA Hiroyuki08e552c2009-01-07 18:08:01 -08001069
1070 page = pc->page;
KAMEZAWA Hiroyuki52d4b9a2008-10-18 20:28:16 -07001071 if (unlikely(!PageCgroupUsed(pc)))
1072 continue;
Hugh Dickins436c65412008-02-07 00:14:12 -08001073 if (unlikely(!PageLRU(page)))
KAMEZAWA Hiroyukiff7283f2008-02-07 00:14:11 -08001074 continue;
KAMEZAWA Hiroyukiff7283f2008-02-07 00:14:11 -08001075
Hugh Dickins436c65412008-02-07 00:14:12 -08001076 scan++;
KAMEZAWA Hiroyuki2ffebca2009-06-17 16:27:21 -07001077 ret = __isolate_lru_page(page, mode, file);
1078 switch (ret) {
1079 case 0:
Balbir Singh66e17072008-02-07 00:13:56 -08001080 list_move(&page->lru, dst);
KAMEZAWA Hiroyuki2ffebca2009-06-17 16:27:21 -07001081 mem_cgroup_del_lru(page);
Balbir Singh66e17072008-02-07 00:13:56 -08001082 nr_taken++;
KAMEZAWA Hiroyuki2ffebca2009-06-17 16:27:21 -07001083 break;
1084 case -EBUSY:
1085 /* we don't affect global LRU but rotate in our LRU */
1086 mem_cgroup_rotate_lru_list(page, page_lru(page));
1087 break;
1088 default:
1089 break;
Balbir Singh66e17072008-02-07 00:13:56 -08001090 }
1091 }
1092
Balbir Singh66e17072008-02-07 00:13:56 -08001093 *scanned = scan;
KOSAKI Motohirocc8e9702010-08-09 17:19:57 -07001094
1095 trace_mm_vmscan_memcg_isolate(0, nr_to_scan, scan, nr_taken,
1096 0, 0, 0, mode);
1097
Balbir Singh66e17072008-02-07 00:13:56 -08001098 return nr_taken;
1099}
1100
Balbir Singh6d61ef42009-01-07 18:08:06 -08001101#define mem_cgroup_from_res_counter(counter, member) \
1102 container_of(counter, struct mem_cgroup, member)
1103
Daisuke Nishimurab85a96c2009-01-07 18:08:12 -08001104static bool mem_cgroup_check_under_limit(struct mem_cgroup *mem)
1105{
1106 if (do_swap_account) {
1107 if (res_counter_check_under_limit(&mem->res) &&
1108 res_counter_check_under_limit(&mem->memsw))
1109 return true;
1110 } else
1111 if (res_counter_check_under_limit(&mem->res))
1112 return true;
1113 return false;
1114}
1115
KOSAKI Motohiroa7885eb2009-01-07 18:08:24 -08001116static unsigned int get_swappiness(struct mem_cgroup *memcg)
1117{
1118 struct cgroup *cgrp = memcg->css.cgroup;
1119 unsigned int swappiness;
1120
1121 /* root ? */
1122 if (cgrp->parent == NULL)
1123 return vm_swappiness;
1124
1125 spin_lock(&memcg->reclaim_param_lock);
1126 swappiness = memcg->swappiness;
1127 spin_unlock(&memcg->reclaim_param_lock);
1128
1129 return swappiness;
1130}
1131
KAMEZAWA Hiroyuki32047e22010-10-27 15:33:40 -07001132static void mem_cgroup_start_move(struct mem_cgroup *mem)
1133{
1134 int cpu;
KAMEZAWA Hiroyuki1489eba2010-10-27 15:33:42 -07001135
1136 get_online_cpus();
1137 spin_lock(&mem->pcp_counter_lock);
1138 for_each_online_cpu(cpu)
KAMEZAWA Hiroyuki32047e22010-10-27 15:33:40 -07001139 per_cpu(mem->stat->count[MEM_CGROUP_ON_MOVE], cpu) += 1;
KAMEZAWA Hiroyuki1489eba2010-10-27 15:33:42 -07001140 mem->nocpu_base.count[MEM_CGROUP_ON_MOVE] += 1;
1141 spin_unlock(&mem->pcp_counter_lock);
1142 put_online_cpus();
KAMEZAWA Hiroyuki32047e22010-10-27 15:33:40 -07001143
1144 synchronize_rcu();
1145}
1146
1147static void mem_cgroup_end_move(struct mem_cgroup *mem)
1148{
1149 int cpu;
1150
1151 if (!mem)
1152 return;
KAMEZAWA Hiroyuki1489eba2010-10-27 15:33:42 -07001153 get_online_cpus();
1154 spin_lock(&mem->pcp_counter_lock);
1155 for_each_online_cpu(cpu)
KAMEZAWA Hiroyuki32047e22010-10-27 15:33:40 -07001156 per_cpu(mem->stat->count[MEM_CGROUP_ON_MOVE], cpu) -= 1;
KAMEZAWA Hiroyuki1489eba2010-10-27 15:33:42 -07001157 mem->nocpu_base.count[MEM_CGROUP_ON_MOVE] -= 1;
1158 spin_unlock(&mem->pcp_counter_lock);
1159 put_online_cpus();
KAMEZAWA Hiroyuki32047e22010-10-27 15:33:40 -07001160}
1161/*
1162 * 2 routines for checking "mem" is under move_account() or not.
1163 *
1164 * mem_cgroup_stealed() - checking a cgroup is mc.from or not. This is used
1165 * for avoiding race in accounting. If true,
1166 * pc->mem_cgroup may be overwritten.
1167 *
1168 * mem_cgroup_under_move() - checking a cgroup is mc.from or mc.to or
1169 * under hierarchy of moving cgroups. This is for
1170 * waiting at hith-memory prressure caused by "move".
1171 */
1172
1173static bool mem_cgroup_stealed(struct mem_cgroup *mem)
1174{
1175 VM_BUG_ON(!rcu_read_lock_held());
1176 return this_cpu_read(mem->stat->count[MEM_CGROUP_ON_MOVE]) > 0;
1177}
KAMEZAWA Hiroyuki4b534332010-08-10 18:02:57 -07001178
1179static bool mem_cgroup_under_move(struct mem_cgroup *mem)
1180{
KAMEZAWA Hiroyuki2bd9bb22010-08-10 18:02:58 -07001181 struct mem_cgroup *from;
1182 struct mem_cgroup *to;
KAMEZAWA Hiroyuki4b534332010-08-10 18:02:57 -07001183 bool ret = false;
KAMEZAWA Hiroyuki2bd9bb22010-08-10 18:02:58 -07001184 /*
1185 * Unlike task_move routines, we access mc.to, mc.from not under
1186 * mutual exclusion by cgroup_mutex. Here, we take spinlock instead.
1187 */
1188 spin_lock(&mc.lock);
1189 from = mc.from;
1190 to = mc.to;
1191 if (!from)
1192 goto unlock;
1193 if (from == mem || to == mem
1194 || (mem->use_hierarchy && css_is_ancestor(&from->css, &mem->css))
1195 || (mem->use_hierarchy && css_is_ancestor(&to->css, &mem->css)))
1196 ret = true;
1197unlock:
1198 spin_unlock(&mc.lock);
KAMEZAWA Hiroyuki4b534332010-08-10 18:02:57 -07001199 return ret;
1200}
1201
1202static bool mem_cgroup_wait_acct_move(struct mem_cgroup *mem)
1203{
1204 if (mc.moving_task && current != mc.moving_task) {
1205 if (mem_cgroup_under_move(mem)) {
1206 DEFINE_WAIT(wait);
1207 prepare_to_wait(&mc.waitq, &wait, TASK_INTERRUPTIBLE);
1208 /* moving charge context might have finished. */
1209 if (mc.moving_task)
1210 schedule();
1211 finish_wait(&mc.waitq, &wait);
1212 return true;
1213 }
1214 }
1215 return false;
1216}
1217
Balbir Singhe2224322009-04-02 16:57:39 -07001218/**
Kirill A. Shutemov6a6135b2010-03-10 15:22:25 -08001219 * mem_cgroup_print_oom_info: Called from OOM with tasklist_lock held in read mode.
Balbir Singhe2224322009-04-02 16:57:39 -07001220 * @memcg: The memory cgroup that went over limit
1221 * @p: Task that is going to be killed
1222 *
1223 * NOTE: @memcg and @p's mem_cgroup can be different when hierarchy is
1224 * enabled
1225 */
1226void mem_cgroup_print_oom_info(struct mem_cgroup *memcg, struct task_struct *p)
1227{
1228 struct cgroup *task_cgrp;
1229 struct cgroup *mem_cgrp;
1230 /*
1231 * Need a buffer in BSS, can't rely on allocations. The code relies
1232 * on the assumption that OOM is serialized for memory controller.
1233 * If this assumption is broken, revisit this code.
1234 */
1235 static char memcg_name[PATH_MAX];
1236 int ret;
1237
Daisuke Nishimurad31f56d2009-12-15 16:47:12 -08001238 if (!memcg || !p)
Balbir Singhe2224322009-04-02 16:57:39 -07001239 return;
1240
1241
1242 rcu_read_lock();
1243
1244 mem_cgrp = memcg->css.cgroup;
1245 task_cgrp = task_cgroup(p, mem_cgroup_subsys_id);
1246
1247 ret = cgroup_path(task_cgrp, memcg_name, PATH_MAX);
1248 if (ret < 0) {
1249 /*
1250 * Unfortunately, we are unable to convert to a useful name
1251 * But we'll still print out the usage information
1252 */
1253 rcu_read_unlock();
1254 goto done;
1255 }
1256 rcu_read_unlock();
1257
1258 printk(KERN_INFO "Task in %s killed", memcg_name);
1259
1260 rcu_read_lock();
1261 ret = cgroup_path(mem_cgrp, memcg_name, PATH_MAX);
1262 if (ret < 0) {
1263 rcu_read_unlock();
1264 goto done;
1265 }
1266 rcu_read_unlock();
1267
1268 /*
1269 * Continues from above, so we don't need an KERN_ level
1270 */
1271 printk(KERN_CONT " as a result of limit of %s\n", memcg_name);
1272done:
1273
1274 printk(KERN_INFO "memory: usage %llukB, limit %llukB, failcnt %llu\n",
1275 res_counter_read_u64(&memcg->res, RES_USAGE) >> 10,
1276 res_counter_read_u64(&memcg->res, RES_LIMIT) >> 10,
1277 res_counter_read_u64(&memcg->res, RES_FAILCNT));
1278 printk(KERN_INFO "memory+swap: usage %llukB, limit %llukB, "
1279 "failcnt %llu\n",
1280 res_counter_read_u64(&memcg->memsw, RES_USAGE) >> 10,
1281 res_counter_read_u64(&memcg->memsw, RES_LIMIT) >> 10,
1282 res_counter_read_u64(&memcg->memsw, RES_FAILCNT));
1283}
1284
KAMEZAWA Hiroyuki81d39c22009-04-02 16:57:36 -07001285/*
1286 * This function returns the number of memcg under hierarchy tree. Returns
1287 * 1(self count) if no children.
1288 */
1289static int mem_cgroup_count_children(struct mem_cgroup *mem)
1290{
1291 int num = 0;
KAMEZAWA Hiroyuki7d74b062010-10-27 15:33:41 -07001292 struct mem_cgroup *iter;
1293
1294 for_each_mem_cgroup_tree(iter, mem)
1295 num++;
KAMEZAWA Hiroyuki81d39c22009-04-02 16:57:36 -07001296 return num;
1297}
1298
Balbir Singh6d61ef42009-01-07 18:08:06 -08001299/*
David Rientjesa63d83f2010-08-09 17:19:46 -07001300 * Return the memory (and swap, if configured) limit for a memcg.
1301 */
1302u64 mem_cgroup_get_limit(struct mem_cgroup *memcg)
1303{
1304 u64 limit;
1305 u64 memsw;
1306
1307 limit = res_counter_read_u64(&memcg->res, RES_LIMIT) +
1308 total_swap_pages;
1309 memsw = res_counter_read_u64(&memcg->memsw, RES_LIMIT);
1310 /*
1311 * If memsw is finite and limits the amount of swap space available
1312 * to this memcg, return that limit.
1313 */
1314 return min(limit, memsw);
1315}
1316
1317/*
KAMEZAWA Hiroyuki04046e12009-04-02 16:57:33 -07001318 * Visit the first child (need not be the first child as per the ordering
1319 * of the cgroup list, since we track last_scanned_child) of @mem and use
1320 * that to reclaim free pages from.
1321 */
1322static struct mem_cgroup *
1323mem_cgroup_select_victim(struct mem_cgroup *root_mem)
1324{
1325 struct mem_cgroup *ret = NULL;
1326 struct cgroup_subsys_state *css;
1327 int nextid, found;
1328
1329 if (!root_mem->use_hierarchy) {
1330 css_get(&root_mem->css);
1331 ret = root_mem;
1332 }
1333
1334 while (!ret) {
1335 rcu_read_lock();
1336 nextid = root_mem->last_scanned_child + 1;
1337 css = css_get_next(&mem_cgroup_subsys, nextid, &root_mem->css,
1338 &found);
1339 if (css && css_tryget(css))
1340 ret = container_of(css, struct mem_cgroup, css);
1341
1342 rcu_read_unlock();
1343 /* Updates scanning parameter */
1344 spin_lock(&root_mem->reclaim_param_lock);
1345 if (!css) {
1346 /* this means start scan from ID:1 */
1347 root_mem->last_scanned_child = 0;
1348 } else
1349 root_mem->last_scanned_child = found;
1350 spin_unlock(&root_mem->reclaim_param_lock);
1351 }
1352
1353 return ret;
1354}
1355
1356/*
1357 * Scan the hierarchy if needed to reclaim memory. We remember the last child
1358 * we reclaimed from, so that we don't end up penalizing one child extensively
1359 * based on its position in the children list.
Balbir Singh6d61ef42009-01-07 18:08:06 -08001360 *
1361 * root_mem is the original ancestor that we've been reclaim from.
KAMEZAWA Hiroyuki04046e12009-04-02 16:57:33 -07001362 *
1363 * We give up and return to the caller when we visit root_mem twice.
1364 * (other groups can be removed while we're walking....)
KAMEZAWA Hiroyuki81d39c22009-04-02 16:57:36 -07001365 *
1366 * If shrink==true, for avoiding to free too much, this returns immedieately.
Balbir Singh6d61ef42009-01-07 18:08:06 -08001367 */
1368static int mem_cgroup_hierarchical_reclaim(struct mem_cgroup *root_mem,
Balbir Singh4e416952009-09-23 15:56:39 -07001369 struct zone *zone,
Balbir Singh75822b42009-09-23 15:56:38 -07001370 gfp_t gfp_mask,
1371 unsigned long reclaim_options)
Balbir Singh6d61ef42009-01-07 18:08:06 -08001372{
KAMEZAWA Hiroyuki04046e12009-04-02 16:57:33 -07001373 struct mem_cgroup *victim;
1374 int ret, total = 0;
1375 int loop = 0;
Balbir Singh75822b42009-09-23 15:56:38 -07001376 bool noswap = reclaim_options & MEM_CGROUP_RECLAIM_NOSWAP;
1377 bool shrink = reclaim_options & MEM_CGROUP_RECLAIM_SHRINK;
Balbir Singh4e416952009-09-23 15:56:39 -07001378 bool check_soft = reclaim_options & MEM_CGROUP_RECLAIM_SOFT;
1379 unsigned long excess = mem_cgroup_get_excess(root_mem);
Balbir Singh6d61ef42009-01-07 18:08:06 -08001380
KAMEZAWA Hiroyuki22a668d2009-06-17 16:27:19 -07001381 /* If memsw_is_minimum==1, swap-out is of-no-use. */
1382 if (root_mem->memsw_is_minimum)
1383 noswap = true;
1384
Balbir Singh4e416952009-09-23 15:56:39 -07001385 while (1) {
KAMEZAWA Hiroyuki04046e12009-04-02 16:57:33 -07001386 victim = mem_cgroup_select_victim(root_mem);
Balbir Singh4e416952009-09-23 15:56:39 -07001387 if (victim == root_mem) {
KAMEZAWA Hiroyuki04046e12009-04-02 16:57:33 -07001388 loop++;
KAMEZAWA Hiroyukicdec2e42009-12-15 16:47:08 -08001389 if (loop >= 1)
1390 drain_all_stock_async();
Balbir Singh4e416952009-09-23 15:56:39 -07001391 if (loop >= 2) {
1392 /*
1393 * If we have not been able to reclaim
1394 * anything, it might because there are
1395 * no reclaimable pages under this hierarchy
1396 */
1397 if (!check_soft || !total) {
1398 css_put(&victim->css);
1399 break;
1400 }
1401 /*
1402 * We want to do more targetted reclaim.
1403 * excess >> 2 is not to excessive so as to
1404 * reclaim too much, nor too less that we keep
1405 * coming back to reclaim from this cgroup
1406 */
1407 if (total >= (excess >> 2) ||
1408 (loop > MEM_CGROUP_MAX_RECLAIM_LOOPS)) {
1409 css_put(&victim->css);
1410 break;
1411 }
1412 }
1413 }
KAMEZAWA Hiroyukic62b1a32010-03-10 15:22:29 -08001414 if (!mem_cgroup_local_usage(victim)) {
KAMEZAWA Hiroyuki04046e12009-04-02 16:57:33 -07001415 /* this cgroup's local usage == 0 */
1416 css_put(&victim->css);
Balbir Singh6d61ef42009-01-07 18:08:06 -08001417 continue;
1418 }
KAMEZAWA Hiroyuki04046e12009-04-02 16:57:33 -07001419 /* we use swappiness of local cgroup */
Balbir Singh4e416952009-09-23 15:56:39 -07001420 if (check_soft)
1421 ret = mem_cgroup_shrink_node_zone(victim, gfp_mask,
KOSAKI Motohiro14fec792010-08-10 18:03:05 -07001422 noswap, get_swappiness(victim), zone);
Balbir Singh4e416952009-09-23 15:56:39 -07001423 else
1424 ret = try_to_free_mem_cgroup_pages(victim, gfp_mask,
1425 noswap, get_swappiness(victim));
KAMEZAWA Hiroyuki04046e12009-04-02 16:57:33 -07001426 css_put(&victim->css);
KAMEZAWA Hiroyuki81d39c22009-04-02 16:57:36 -07001427 /*
1428 * At shrinking usage, we can't check we should stop here or
1429 * reclaim more. It's depends on callers. last_scanned_child
1430 * will work enough for keeping fairness under tree.
1431 */
1432 if (shrink)
1433 return ret;
KAMEZAWA Hiroyuki04046e12009-04-02 16:57:33 -07001434 total += ret;
Balbir Singh4e416952009-09-23 15:56:39 -07001435 if (check_soft) {
1436 if (res_counter_check_under_soft_limit(&root_mem->res))
1437 return total;
1438 } else if (mem_cgroup_check_under_limit(root_mem))
KAMEZAWA Hiroyuki04046e12009-04-02 16:57:33 -07001439 return 1 + total;
Balbir Singh6d61ef42009-01-07 18:08:06 -08001440 }
KAMEZAWA Hiroyuki04046e12009-04-02 16:57:33 -07001441 return total;
Balbir Singh6d61ef42009-01-07 18:08:06 -08001442}
1443
KAMEZAWA Hiroyuki867578c2010-03-10 15:22:39 -08001444/*
1445 * Check OOM-Killer is already running under our hierarchy.
1446 * If someone is running, return false.
1447 */
1448static bool mem_cgroup_oom_lock(struct mem_cgroup *mem)
1449{
KAMEZAWA Hiroyuki7d74b062010-10-27 15:33:41 -07001450 int x, lock_count = 0;
1451 struct mem_cgroup *iter;
KAMEZAWA Hiroyukia636b322009-01-07 18:08:08 -08001452
KAMEZAWA Hiroyuki7d74b062010-10-27 15:33:41 -07001453 for_each_mem_cgroup_tree(iter, mem) {
1454 x = atomic_inc_return(&iter->oom_lock);
1455 lock_count = max(x, lock_count);
1456 }
KAMEZAWA Hiroyuki867578c2010-03-10 15:22:39 -08001457
1458 if (lock_count == 1)
1459 return true;
1460 return false;
KAMEZAWA Hiroyukia636b322009-01-07 18:08:08 -08001461}
KAMEZAWA Hiroyuki0b7f5692009-04-02 16:57:38 -07001462
KAMEZAWA Hiroyuki7d74b062010-10-27 15:33:41 -07001463static int mem_cgroup_oom_unlock(struct mem_cgroup *mem)
KAMEZAWA Hiroyuki0b7f5692009-04-02 16:57:38 -07001464{
KAMEZAWA Hiroyuki7d74b062010-10-27 15:33:41 -07001465 struct mem_cgroup *iter;
1466
KAMEZAWA Hiroyuki867578c2010-03-10 15:22:39 -08001467 /*
1468 * When a new child is created while the hierarchy is under oom,
1469 * mem_cgroup_oom_lock() may not be called. We have to use
1470 * atomic_add_unless() here.
1471 */
KAMEZAWA Hiroyuki7d74b062010-10-27 15:33:41 -07001472 for_each_mem_cgroup_tree(iter, mem)
1473 atomic_add_unless(&iter->oom_lock, -1, 0);
KAMEZAWA Hiroyuki0b7f5692009-04-02 16:57:38 -07001474 return 0;
1475}
1476
KAMEZAWA Hiroyuki867578c2010-03-10 15:22:39 -08001477
1478static DEFINE_MUTEX(memcg_oom_mutex);
1479static DECLARE_WAIT_QUEUE_HEAD(memcg_oom_waitq);
1480
KAMEZAWA Hiroyukidc98df52010-05-26 14:42:36 -07001481struct oom_wait_info {
1482 struct mem_cgroup *mem;
1483 wait_queue_t wait;
1484};
1485
1486static int memcg_oom_wake_function(wait_queue_t *wait,
1487 unsigned mode, int sync, void *arg)
1488{
1489 struct mem_cgroup *wake_mem = (struct mem_cgroup *)arg;
1490 struct oom_wait_info *oom_wait_info;
1491
1492 oom_wait_info = container_of(wait, struct oom_wait_info, wait);
1493
1494 if (oom_wait_info->mem == wake_mem)
1495 goto wakeup;
1496 /* if no hierarchy, no match */
1497 if (!oom_wait_info->mem->use_hierarchy || !wake_mem->use_hierarchy)
1498 return 0;
1499 /*
1500 * Both of oom_wait_info->mem and wake_mem are stable under us.
1501 * Then we can use css_is_ancestor without taking care of RCU.
1502 */
1503 if (!css_is_ancestor(&oom_wait_info->mem->css, &wake_mem->css) &&
1504 !css_is_ancestor(&wake_mem->css, &oom_wait_info->mem->css))
1505 return 0;
1506
1507wakeup:
1508 return autoremove_wake_function(wait, mode, sync, arg);
1509}
1510
1511static void memcg_wakeup_oom(struct mem_cgroup *mem)
1512{
1513 /* for filtering, pass "mem" as argument. */
1514 __wake_up(&memcg_oom_waitq, TASK_NORMAL, 0, mem);
1515}
1516
KAMEZAWA Hiroyuki3c11ecf2010-05-26 14:42:37 -07001517static void memcg_oom_recover(struct mem_cgroup *mem)
1518{
KAMEZAWA Hiroyuki2bd9bb22010-08-10 18:02:58 -07001519 if (mem && atomic_read(&mem->oom_lock))
KAMEZAWA Hiroyuki3c11ecf2010-05-26 14:42:37 -07001520 memcg_wakeup_oom(mem);
1521}
1522
KAMEZAWA Hiroyuki867578c2010-03-10 15:22:39 -08001523/*
1524 * try to call OOM killer. returns false if we should exit memory-reclaim loop.
1525 */
1526bool mem_cgroup_handle_oom(struct mem_cgroup *mem, gfp_t mask)
1527{
KAMEZAWA Hiroyukidc98df52010-05-26 14:42:36 -07001528 struct oom_wait_info owait;
KAMEZAWA Hiroyuki3c11ecf2010-05-26 14:42:37 -07001529 bool locked, need_to_kill;
KAMEZAWA Hiroyuki867578c2010-03-10 15:22:39 -08001530
KAMEZAWA Hiroyukidc98df52010-05-26 14:42:36 -07001531 owait.mem = mem;
1532 owait.wait.flags = 0;
1533 owait.wait.func = memcg_oom_wake_function;
1534 owait.wait.private = current;
1535 INIT_LIST_HEAD(&owait.wait.task_list);
KAMEZAWA Hiroyuki3c11ecf2010-05-26 14:42:37 -07001536 need_to_kill = true;
KAMEZAWA Hiroyuki867578c2010-03-10 15:22:39 -08001537 /* At first, try to OOM lock hierarchy under mem.*/
1538 mutex_lock(&memcg_oom_mutex);
1539 locked = mem_cgroup_oom_lock(mem);
1540 /*
1541 * Even if signal_pending(), we can't quit charge() loop without
1542 * accounting. So, UNINTERRUPTIBLE is appropriate. But SIGKILL
1543 * under OOM is always welcomed, use TASK_KILLABLE here.
1544 */
KAMEZAWA Hiroyuki3c11ecf2010-05-26 14:42:37 -07001545 prepare_to_wait(&memcg_oom_waitq, &owait.wait, TASK_KILLABLE);
1546 if (!locked || mem->oom_kill_disable)
1547 need_to_kill = false;
1548 if (locked)
KAMEZAWA Hiroyuki9490ff22010-05-26 14:42:36 -07001549 mem_cgroup_oom_notify(mem);
KAMEZAWA Hiroyuki867578c2010-03-10 15:22:39 -08001550 mutex_unlock(&memcg_oom_mutex);
1551
KAMEZAWA Hiroyuki3c11ecf2010-05-26 14:42:37 -07001552 if (need_to_kill) {
1553 finish_wait(&memcg_oom_waitq, &owait.wait);
KAMEZAWA Hiroyuki867578c2010-03-10 15:22:39 -08001554 mem_cgroup_out_of_memory(mem, mask);
KAMEZAWA Hiroyuki3c11ecf2010-05-26 14:42:37 -07001555 } else {
KAMEZAWA Hiroyuki867578c2010-03-10 15:22:39 -08001556 schedule();
KAMEZAWA Hiroyukidc98df52010-05-26 14:42:36 -07001557 finish_wait(&memcg_oom_waitq, &owait.wait);
KAMEZAWA Hiroyuki867578c2010-03-10 15:22:39 -08001558 }
1559 mutex_lock(&memcg_oom_mutex);
1560 mem_cgroup_oom_unlock(mem);
KAMEZAWA Hiroyukidc98df52010-05-26 14:42:36 -07001561 memcg_wakeup_oom(mem);
KAMEZAWA Hiroyuki867578c2010-03-10 15:22:39 -08001562 mutex_unlock(&memcg_oom_mutex);
1563
1564 if (test_thread_flag(TIF_MEMDIE) || fatal_signal_pending(current))
1565 return false;
1566 /* Give chance to dying process */
1567 schedule_timeout(1);
1568 return true;
KAMEZAWA Hiroyuki0b7f5692009-04-02 16:57:38 -07001569}
1570
Balbir Singhd69b0422009-06-17 16:26:34 -07001571/*
1572 * Currently used to update mapped file statistics, but the routine can be
1573 * generalized to update other statistics as well.
KAMEZAWA Hiroyuki32047e22010-10-27 15:33:40 -07001574 *
1575 * Notes: Race condition
1576 *
1577 * We usually use page_cgroup_lock() for accessing page_cgroup member but
1578 * it tends to be costly. But considering some conditions, we doesn't need
1579 * to do so _always_.
1580 *
1581 * Considering "charge", lock_page_cgroup() is not required because all
1582 * file-stat operations happen after a page is attached to radix-tree. There
1583 * are no race with "charge".
1584 *
1585 * Considering "uncharge", we know that memcg doesn't clear pc->mem_cgroup
1586 * at "uncharge" intentionally. So, we always see valid pc->mem_cgroup even
1587 * if there are race with "uncharge". Statistics itself is properly handled
1588 * by flags.
1589 *
1590 * Considering "move", this is an only case we see a race. To make the race
1591 * small, we check MEM_CGROUP_ON_MOVE percpu value and detect there are
1592 * possibility of race condition. If there is, we take a lock.
Balbir Singhd69b0422009-06-17 16:26:34 -07001593 */
KAMEZAWA Hiroyuki26174ef2010-10-27 15:33:43 -07001594
1595static void mem_cgroup_update_file_stat(struct page *page, int idx, int val)
Balbir Singhd69b0422009-06-17 16:26:34 -07001596{
1597 struct mem_cgroup *mem;
KAMEZAWA Hiroyuki32047e22010-10-27 15:33:40 -07001598 struct page_cgroup *pc = lookup_page_cgroup(page);
1599 bool need_unlock = false;
Balbir Singhd69b0422009-06-17 16:26:34 -07001600
Balbir Singhd69b0422009-06-17 16:26:34 -07001601 if (unlikely(!pc))
1602 return;
1603
KAMEZAWA Hiroyuki32047e22010-10-27 15:33:40 -07001604 rcu_read_lock();
Balbir Singhd69b0422009-06-17 16:26:34 -07001605 mem = pc->mem_cgroup;
KAMEZAWA Hiroyuki32047e22010-10-27 15:33:40 -07001606 if (unlikely(!mem || !PageCgroupUsed(pc)))
1607 goto out;
1608 /* pc->mem_cgroup is unstable ? */
1609 if (unlikely(mem_cgroup_stealed(mem))) {
1610 /* take a lock against to access pc->mem_cgroup */
1611 lock_page_cgroup(pc);
1612 need_unlock = true;
1613 mem = pc->mem_cgroup;
1614 if (!mem || !PageCgroupUsed(pc))
1615 goto out;
1616 }
KAMEZAWA Hiroyuki26174ef2010-10-27 15:33:43 -07001617
1618 this_cpu_add(mem->stat->count[idx], val);
1619
1620 switch (idx) {
1621 case MEM_CGROUP_STAT_FILE_MAPPED:
1622 if (val > 0)
1623 SetPageCgroupFileMapped(pc);
1624 else if (!page_mapped(page))
KAMEZAWA Hiroyuki0c270f82010-10-27 15:33:39 -07001625 ClearPageCgroupFileMapped(pc);
KAMEZAWA Hiroyuki26174ef2010-10-27 15:33:43 -07001626 break;
1627 default:
1628 BUG();
KAMEZAWA Hiroyuki8725d542010-04-06 14:35:05 -07001629 }
Balbir Singhd69b0422009-06-17 16:26:34 -07001630
KAMEZAWA Hiroyuki32047e22010-10-27 15:33:40 -07001631out:
1632 if (unlikely(need_unlock))
1633 unlock_page_cgroup(pc);
1634 rcu_read_unlock();
1635 return;
Balbir Singhd69b0422009-06-17 16:26:34 -07001636}
KAMEZAWA Hiroyuki0b7f5692009-04-02 16:57:38 -07001637
KAMEZAWA Hiroyuki26174ef2010-10-27 15:33:43 -07001638void mem_cgroup_update_file_mapped(struct page *page, int val)
1639{
1640 mem_cgroup_update_file_stat(page, MEM_CGROUP_STAT_FILE_MAPPED, val);
1641}
1642
KAMEZAWA Hiroyukif817ed42009-01-07 18:07:53 -08001643/*
KAMEZAWA Hiroyukicdec2e42009-12-15 16:47:08 -08001644 * size of first charge trial. "32" comes from vmscan.c's magic value.
1645 * TODO: maybe necessary to use big numbers in big irons.
1646 */
1647#define CHARGE_SIZE (32 * PAGE_SIZE)
1648struct memcg_stock_pcp {
1649 struct mem_cgroup *cached; /* this never be root cgroup */
1650 int charge;
1651 struct work_struct work;
1652};
1653static DEFINE_PER_CPU(struct memcg_stock_pcp, memcg_stock);
1654static atomic_t memcg_drain_count;
1655
1656/*
1657 * Try to consume stocked charge on this cpu. If success, PAGE_SIZE is consumed
1658 * from local stock and true is returned. If the stock is 0 or charges from a
1659 * cgroup which is not current target, returns false. This stock will be
1660 * refilled.
1661 */
1662static bool consume_stock(struct mem_cgroup *mem)
1663{
1664 struct memcg_stock_pcp *stock;
1665 bool ret = true;
1666
1667 stock = &get_cpu_var(memcg_stock);
1668 if (mem == stock->cached && stock->charge)
1669 stock->charge -= PAGE_SIZE;
1670 else /* need to call res_counter_charge */
1671 ret = false;
1672 put_cpu_var(memcg_stock);
1673 return ret;
1674}
1675
1676/*
1677 * Returns stocks cached in percpu to res_counter and reset cached information.
1678 */
1679static void drain_stock(struct memcg_stock_pcp *stock)
1680{
1681 struct mem_cgroup *old = stock->cached;
1682
1683 if (stock->charge) {
1684 res_counter_uncharge(&old->res, stock->charge);
1685 if (do_swap_account)
1686 res_counter_uncharge(&old->memsw, stock->charge);
1687 }
1688 stock->cached = NULL;
1689 stock->charge = 0;
1690}
1691
1692/*
1693 * This must be called under preempt disabled or must be called by
1694 * a thread which is pinned to local cpu.
1695 */
1696static void drain_local_stock(struct work_struct *dummy)
1697{
1698 struct memcg_stock_pcp *stock = &__get_cpu_var(memcg_stock);
1699 drain_stock(stock);
1700}
1701
1702/*
1703 * Cache charges(val) which is from res_counter, to local per_cpu area.
Greg Thelen320cc512010-03-15 15:27:28 +01001704 * This will be consumed by consume_stock() function, later.
KAMEZAWA Hiroyukicdec2e42009-12-15 16:47:08 -08001705 */
1706static void refill_stock(struct mem_cgroup *mem, int val)
1707{
1708 struct memcg_stock_pcp *stock = &get_cpu_var(memcg_stock);
1709
1710 if (stock->cached != mem) { /* reset if necessary */
1711 drain_stock(stock);
1712 stock->cached = mem;
1713 }
1714 stock->charge += val;
1715 put_cpu_var(memcg_stock);
1716}
1717
1718/*
1719 * Tries to drain stocked charges in other cpus. This function is asynchronous
1720 * and just put a work per cpu for draining localy on each cpu. Caller can
1721 * expects some charges will be back to res_counter later but cannot wait for
1722 * it.
1723 */
1724static void drain_all_stock_async(void)
1725{
1726 int cpu;
1727 /* This function is for scheduling "drain" in asynchronous way.
1728 * The result of "drain" is not directly handled by callers. Then,
1729 * if someone is calling drain, we don't have to call drain more.
1730 * Anyway, WORK_STRUCT_PENDING check in queue_work_on() will catch if
1731 * there is a race. We just do loose check here.
1732 */
1733 if (atomic_read(&memcg_drain_count))
1734 return;
1735 /* Notify other cpus that system-wide "drain" is running */
1736 atomic_inc(&memcg_drain_count);
1737 get_online_cpus();
1738 for_each_online_cpu(cpu) {
1739 struct memcg_stock_pcp *stock = &per_cpu(memcg_stock, cpu);
1740 schedule_work_on(cpu, &stock->work);
1741 }
1742 put_online_cpus();
1743 atomic_dec(&memcg_drain_count);
1744 /* We don't wait for flush_work */
1745}
1746
1747/* This is a synchronous drain interface. */
1748static void drain_all_stock_sync(void)
1749{
1750 /* called when force_empty is called */
1751 atomic_inc(&memcg_drain_count);
1752 schedule_on_each_cpu(drain_local_stock);
1753 atomic_dec(&memcg_drain_count);
1754}
1755
KAMEZAWA Hiroyuki711d3d22010-10-27 15:33:42 -07001756/*
1757 * This function drains percpu counter value from DEAD cpu and
1758 * move it to local cpu. Note that this function can be preempted.
1759 */
1760static void mem_cgroup_drain_pcp_counter(struct mem_cgroup *mem, int cpu)
1761{
1762 int i;
1763
1764 spin_lock(&mem->pcp_counter_lock);
1765 for (i = 0; i < MEM_CGROUP_STAT_DATA; i++) {
1766 s64 x = per_cpu(mem->stat->count[i], cpu);
1767
1768 per_cpu(mem->stat->count[i], cpu) = 0;
1769 mem->nocpu_base.count[i] += x;
1770 }
KAMEZAWA Hiroyuki1489eba2010-10-27 15:33:42 -07001771 /* need to clear ON_MOVE value, works as a kind of lock. */
1772 per_cpu(mem->stat->count[MEM_CGROUP_ON_MOVE], cpu) = 0;
1773 spin_unlock(&mem->pcp_counter_lock);
1774}
1775
1776static void synchronize_mem_cgroup_on_move(struct mem_cgroup *mem, int cpu)
1777{
1778 int idx = MEM_CGROUP_ON_MOVE;
1779
1780 spin_lock(&mem->pcp_counter_lock);
1781 per_cpu(mem->stat->count[idx], cpu) = mem->nocpu_base.count[idx];
KAMEZAWA Hiroyuki711d3d22010-10-27 15:33:42 -07001782 spin_unlock(&mem->pcp_counter_lock);
1783}
1784
1785static int __cpuinit memcg_cpu_hotplug_callback(struct notifier_block *nb,
KAMEZAWA Hiroyukicdec2e42009-12-15 16:47:08 -08001786 unsigned long action,
1787 void *hcpu)
1788{
1789 int cpu = (unsigned long)hcpu;
1790 struct memcg_stock_pcp *stock;
KAMEZAWA Hiroyuki711d3d22010-10-27 15:33:42 -07001791 struct mem_cgroup *iter;
KAMEZAWA Hiroyukicdec2e42009-12-15 16:47:08 -08001792
KAMEZAWA Hiroyuki1489eba2010-10-27 15:33:42 -07001793 if ((action == CPU_ONLINE)) {
1794 for_each_mem_cgroup_all(iter)
1795 synchronize_mem_cgroup_on_move(iter, cpu);
1796 return NOTIFY_OK;
1797 }
1798
KAMEZAWA Hiroyuki711d3d22010-10-27 15:33:42 -07001799 if ((action != CPU_DEAD) || action != CPU_DEAD_FROZEN)
KAMEZAWA Hiroyukicdec2e42009-12-15 16:47:08 -08001800 return NOTIFY_OK;
KAMEZAWA Hiroyuki711d3d22010-10-27 15:33:42 -07001801
1802 for_each_mem_cgroup_all(iter)
1803 mem_cgroup_drain_pcp_counter(iter, cpu);
1804
KAMEZAWA Hiroyukicdec2e42009-12-15 16:47:08 -08001805 stock = &per_cpu(memcg_stock, cpu);
1806 drain_stock(stock);
1807 return NOTIFY_OK;
1808}
1809
KAMEZAWA Hiroyuki4b534332010-08-10 18:02:57 -07001810
1811/* See __mem_cgroup_try_charge() for details */
1812enum {
1813 CHARGE_OK, /* success */
1814 CHARGE_RETRY, /* need to retry but retry is not bad */
1815 CHARGE_NOMEM, /* we can't do more. return -ENOMEM */
1816 CHARGE_WOULDBLOCK, /* GFP_WAIT wasn't set and no enough res. */
1817 CHARGE_OOM_DIE, /* the current is killed because of OOM */
1818};
1819
1820static int __mem_cgroup_do_charge(struct mem_cgroup *mem, gfp_t gfp_mask,
1821 int csize, bool oom_check)
1822{
1823 struct mem_cgroup *mem_over_limit;
1824 struct res_counter *fail_res;
1825 unsigned long flags = 0;
1826 int ret;
1827
1828 ret = res_counter_charge(&mem->res, csize, &fail_res);
1829
1830 if (likely(!ret)) {
1831 if (!do_swap_account)
1832 return CHARGE_OK;
1833 ret = res_counter_charge(&mem->memsw, csize, &fail_res);
1834 if (likely(!ret))
1835 return CHARGE_OK;
1836
1837 mem_over_limit = mem_cgroup_from_res_counter(fail_res, memsw);
1838 flags |= MEM_CGROUP_RECLAIM_NOSWAP;
1839 } else
1840 mem_over_limit = mem_cgroup_from_res_counter(fail_res, res);
1841
1842 if (csize > PAGE_SIZE) /* change csize and retry */
1843 return CHARGE_RETRY;
1844
1845 if (!(gfp_mask & __GFP_WAIT))
1846 return CHARGE_WOULDBLOCK;
1847
1848 ret = mem_cgroup_hierarchical_reclaim(mem_over_limit, NULL,
1849 gfp_mask, flags);
1850 /*
1851 * try_to_free_mem_cgroup_pages() might not give us a full
1852 * picture of reclaim. Some pages are reclaimed and might be
1853 * moved to swap cache or just unmapped from the cgroup.
1854 * Check the limit again to see if the reclaim reduced the
1855 * current usage of the cgroup before giving up
1856 */
1857 if (ret || mem_cgroup_check_under_limit(mem_over_limit))
1858 return CHARGE_RETRY;
1859
1860 /*
1861 * At task move, charge accounts can be doubly counted. So, it's
1862 * better to wait until the end of task_move if something is going on.
1863 */
1864 if (mem_cgroup_wait_acct_move(mem_over_limit))
1865 return CHARGE_RETRY;
1866
1867 /* If we don't need to call oom-killer at el, return immediately */
1868 if (!oom_check)
1869 return CHARGE_NOMEM;
1870 /* check OOM */
1871 if (!mem_cgroup_handle_oom(mem_over_limit, gfp_mask))
1872 return CHARGE_OOM_DIE;
1873
1874 return CHARGE_RETRY;
1875}
1876
KAMEZAWA Hiroyukicdec2e42009-12-15 16:47:08 -08001877/*
KAMEZAWA Hiroyukif817ed42009-01-07 18:07:53 -08001878 * Unlike exported interface, "oom" parameter is added. if oom==true,
1879 * oom-killer can be invoked.
Balbir Singh8a9f3cc2008-02-07 00:13:53 -08001880 */
KAMEZAWA Hiroyukif817ed42009-01-07 18:07:53 -08001881static int __mem_cgroup_try_charge(struct mm_struct *mm,
KAMEZAWA Hiroyuki4b534332010-08-10 18:02:57 -07001882 gfp_t gfp_mask, struct mem_cgroup **memcg, bool oom)
Balbir Singh8a9f3cc2008-02-07 00:13:53 -08001883{
KAMEZAWA Hiroyuki4b534332010-08-10 18:02:57 -07001884 int nr_oom_retries = MEM_CGROUP_RECLAIM_RETRIES;
1885 struct mem_cgroup *mem = NULL;
1886 int ret;
KAMEZAWA Hiroyukicdec2e42009-12-15 16:47:08 -08001887 int csize = CHARGE_SIZE;
KAMEZAWA Hiroyukia636b322009-01-07 18:08:08 -08001888
KAMEZAWA Hiroyuki867578c2010-03-10 15:22:39 -08001889 /*
1890 * Unlike gloval-vm's OOM-kill, we're not in memory shortage
1891 * in system level. So, allow to go ahead dying process in addition to
1892 * MEMDIE process.
1893 */
1894 if (unlikely(test_thread_flag(TIF_MEMDIE)
1895 || fatal_signal_pending(current)))
1896 goto bypass;
KAMEZAWA Hiroyukia636b322009-01-07 18:08:08 -08001897
Balbir Singh8a9f3cc2008-02-07 00:13:53 -08001898 /*
Hugh Dickins3be91272008-02-07 00:14:19 -08001899 * We always charge the cgroup the mm_struct belongs to.
1900 * The mm_struct's mem_cgroup changes on task migration if the
Balbir Singh8a9f3cc2008-02-07 00:13:53 -08001901 * thread group leader migrates. It's possible that mm is not
1902 * set, if so charge the init_mm (happens for pagecache usage).
1903 */
KAMEZAWA Hiroyukif75ca962010-08-10 18:03:02 -07001904 if (!*memcg && !mm)
1905 goto bypass;
1906again:
1907 if (*memcg) { /* css should be a valid one */
KAMEZAWA Hiroyuki4b534332010-08-10 18:02:57 -07001908 mem = *memcg;
KAMEZAWA Hiroyukif75ca962010-08-10 18:03:02 -07001909 VM_BUG_ON(css_is_removed(&mem->css));
1910 if (mem_cgroup_is_root(mem))
1911 goto done;
1912 if (consume_stock(mem))
1913 goto done;
KAMEZAWA Hiroyuki7a81b882009-01-07 18:07:48 -08001914 css_get(&mem->css);
KAMEZAWA Hiroyuki4b534332010-08-10 18:02:57 -07001915 } else {
KAMEZAWA Hiroyukif75ca962010-08-10 18:03:02 -07001916 struct task_struct *p;
KAMEZAWA Hiroyuki54595fe2009-01-07 18:08:33 -08001917
KAMEZAWA Hiroyukif75ca962010-08-10 18:03:02 -07001918 rcu_read_lock();
1919 p = rcu_dereference(mm->owner);
1920 VM_BUG_ON(!p);
1921 /*
1922 * because we don't have task_lock(), "p" can exit while
1923 * we're here. In that case, "mem" can point to root
1924 * cgroup but never be NULL. (and task_struct itself is freed
1925 * by RCU, cgroup itself is RCU safe.) Then, we have small
1926 * risk here to get wrong cgroup. But such kind of mis-account
1927 * by race always happens because we don't have cgroup_mutex().
1928 * It's overkill and we allow that small race, here.
1929 */
1930 mem = mem_cgroup_from_task(p);
1931 VM_BUG_ON(!mem);
1932 if (mem_cgroup_is_root(mem)) {
1933 rcu_read_unlock();
1934 goto done;
1935 }
1936 if (consume_stock(mem)) {
1937 /*
1938 * It seems dagerous to access memcg without css_get().
1939 * But considering how consume_stok works, it's not
1940 * necessary. If consume_stock success, some charges
1941 * from this memcg are cached on this cpu. So, we
1942 * don't need to call css_get()/css_tryget() before
1943 * calling consume_stock().
1944 */
1945 rcu_read_unlock();
1946 goto done;
1947 }
1948 /* after here, we may be blocked. we need to get refcnt */
1949 if (!css_tryget(&mem->css)) {
1950 rcu_read_unlock();
1951 goto again;
1952 }
1953 rcu_read_unlock();
1954 }
Balbir Singh8a9f3cc2008-02-07 00:13:53 -08001955
KAMEZAWA Hiroyuki4b534332010-08-10 18:02:57 -07001956 do {
1957 bool oom_check;
KAMEZAWA Hiroyuki7a81b882009-01-07 18:07:48 -08001958
KAMEZAWA Hiroyuki4b534332010-08-10 18:02:57 -07001959 /* If killed, bypass charge */
KAMEZAWA Hiroyukif75ca962010-08-10 18:03:02 -07001960 if (fatal_signal_pending(current)) {
1961 css_put(&mem->css);
KAMEZAWA Hiroyuki4b534332010-08-10 18:02:57 -07001962 goto bypass;
KAMEZAWA Hiroyukif75ca962010-08-10 18:03:02 -07001963 }
KAMEZAWA Hiroyukicdec2e42009-12-15 16:47:08 -08001964
KAMEZAWA Hiroyuki4b534332010-08-10 18:02:57 -07001965 oom_check = false;
1966 if (oom && !nr_oom_retries) {
1967 oom_check = true;
1968 nr_oom_retries = MEM_CGROUP_RECLAIM_RETRIES;
1969 }
Balbir Singh6d61ef42009-01-07 18:08:06 -08001970
KAMEZAWA Hiroyuki4b534332010-08-10 18:02:57 -07001971 ret = __mem_cgroup_do_charge(mem, gfp_mask, csize, oom_check);
1972
1973 switch (ret) {
1974 case CHARGE_OK:
1975 break;
1976 case CHARGE_RETRY: /* not in OOM situation but retry */
KAMEZAWA Hiroyukicdec2e42009-12-15 16:47:08 -08001977 csize = PAGE_SIZE;
KAMEZAWA Hiroyukif75ca962010-08-10 18:03:02 -07001978 css_put(&mem->css);
1979 mem = NULL;
1980 goto again;
KAMEZAWA Hiroyuki4b534332010-08-10 18:02:57 -07001981 case CHARGE_WOULDBLOCK: /* !__GFP_WAIT */
KAMEZAWA Hiroyukif75ca962010-08-10 18:03:02 -07001982 css_put(&mem->css);
KAMEZAWA Hiroyuki7a81b882009-01-07 18:07:48 -08001983 goto nomem;
KAMEZAWA Hiroyuki4b534332010-08-10 18:02:57 -07001984 case CHARGE_NOMEM: /* OOM routine works */
KAMEZAWA Hiroyukif75ca962010-08-10 18:03:02 -07001985 if (!oom) {
1986 css_put(&mem->css);
KAMEZAWA Hiroyuki867578c2010-03-10 15:22:39 -08001987 goto nomem;
KAMEZAWA Hiroyukif75ca962010-08-10 18:03:02 -07001988 }
KAMEZAWA Hiroyuki4b534332010-08-10 18:02:57 -07001989 /* If oom, we never return -ENOMEM */
1990 nr_oom_retries--;
1991 break;
1992 case CHARGE_OOM_DIE: /* Killed by OOM Killer */
KAMEZAWA Hiroyukif75ca962010-08-10 18:03:02 -07001993 css_put(&mem->css);
KAMEZAWA Hiroyuki867578c2010-03-10 15:22:39 -08001994 goto bypass;
Balbir Singh66e17072008-02-07 00:13:56 -08001995 }
KAMEZAWA Hiroyuki4b534332010-08-10 18:02:57 -07001996 } while (ret != CHARGE_OK);
1997
KAMEZAWA Hiroyukicdec2e42009-12-15 16:47:08 -08001998 if (csize > PAGE_SIZE)
1999 refill_stock(mem, csize - PAGE_SIZE);
KAMEZAWA Hiroyukif75ca962010-08-10 18:03:02 -07002000 css_put(&mem->css);
Balbir Singh0c3e73e2009-09-23 15:56:42 -07002001done:
KAMEZAWA Hiroyukif75ca962010-08-10 18:03:02 -07002002 *memcg = mem;
KAMEZAWA Hiroyuki7a81b882009-01-07 18:07:48 -08002003 return 0;
2004nomem:
KAMEZAWA Hiroyukif75ca962010-08-10 18:03:02 -07002005 *memcg = NULL;
KAMEZAWA Hiroyuki7a81b882009-01-07 18:07:48 -08002006 return -ENOMEM;
KAMEZAWA Hiroyuki867578c2010-03-10 15:22:39 -08002007bypass:
2008 *memcg = NULL;
2009 return 0;
KAMEZAWA Hiroyuki7a81b882009-01-07 18:07:48 -08002010}
Balbir Singh8a9f3cc2008-02-07 00:13:53 -08002011
KAMEZAWA Hiroyukia3b2d692009-04-02 16:57:45 -07002012/*
Daisuke Nishimuraa3032a22009-12-15 16:47:10 -08002013 * Somemtimes we have to undo a charge we got by try_charge().
2014 * This function is for that and do uncharge, put css's refcnt.
2015 * gotten by try_charge().
2016 */
Daisuke Nishimura854ffa82010-03-10 15:22:15 -08002017static void __mem_cgroup_cancel_charge(struct mem_cgroup *mem,
2018 unsigned long count)
Daisuke Nishimuraa3032a22009-12-15 16:47:10 -08002019{
2020 if (!mem_cgroup_is_root(mem)) {
Daisuke Nishimura854ffa82010-03-10 15:22:15 -08002021 res_counter_uncharge(&mem->res, PAGE_SIZE * count);
Daisuke Nishimuraa3032a22009-12-15 16:47:10 -08002022 if (do_swap_account)
Daisuke Nishimura854ffa82010-03-10 15:22:15 -08002023 res_counter_uncharge(&mem->memsw, PAGE_SIZE * count);
Daisuke Nishimuraa3032a22009-12-15 16:47:10 -08002024 }
Daisuke Nishimura854ffa82010-03-10 15:22:15 -08002025}
2026
2027static void mem_cgroup_cancel_charge(struct mem_cgroup *mem)
2028{
2029 __mem_cgroup_cancel_charge(mem, 1);
Daisuke Nishimuraa3032a22009-12-15 16:47:10 -08002030}
2031
2032/*
KAMEZAWA Hiroyukia3b2d692009-04-02 16:57:45 -07002033 * A helper function to get mem_cgroup from ID. must be called under
2034 * rcu_read_lock(). The caller must check css_is_removed() or some if
2035 * it's concern. (dropping refcnt from swap can be called against removed
2036 * memcg.)
2037 */
2038static struct mem_cgroup *mem_cgroup_lookup(unsigned short id)
2039{
2040 struct cgroup_subsys_state *css;
2041
2042 /* ID 0 is unused ID */
2043 if (!id)
2044 return NULL;
2045 css = css_lookup(&mem_cgroup_subsys, id);
2046 if (!css)
2047 return NULL;
2048 return container_of(css, struct mem_cgroup, css);
2049}
2050
Wu Fengguange42d9d52009-12-16 12:19:59 +01002051struct mem_cgroup *try_get_mem_cgroup_from_page(struct page *page)
KAMEZAWA Hiroyukib5a84312009-01-07 18:08:35 -08002052{
Wu Fengguange42d9d52009-12-16 12:19:59 +01002053 struct mem_cgroup *mem = NULL;
Daisuke Nishimura3c776e62009-04-02 16:57:43 -07002054 struct page_cgroup *pc;
KAMEZAWA Hiroyukia3b2d692009-04-02 16:57:45 -07002055 unsigned short id;
KAMEZAWA Hiroyukib5a84312009-01-07 18:08:35 -08002056 swp_entry_t ent;
2057
Daisuke Nishimura3c776e62009-04-02 16:57:43 -07002058 VM_BUG_ON(!PageLocked(page));
2059
Daisuke Nishimura3c776e62009-04-02 16:57:43 -07002060 pc = lookup_page_cgroup(page);
Daisuke Nishimurac0bd3f62009-04-30 15:08:11 -07002061 lock_page_cgroup(pc);
KAMEZAWA Hiroyukia3b2d692009-04-02 16:57:45 -07002062 if (PageCgroupUsed(pc)) {
Daisuke Nishimura3c776e62009-04-02 16:57:43 -07002063 mem = pc->mem_cgroup;
KAMEZAWA Hiroyukia3b2d692009-04-02 16:57:45 -07002064 if (mem && !css_tryget(&mem->css))
2065 mem = NULL;
Wu Fengguange42d9d52009-12-16 12:19:59 +01002066 } else if (PageSwapCache(page)) {
Daisuke Nishimura3c776e62009-04-02 16:57:43 -07002067 ent.val = page_private(page);
KAMEZAWA Hiroyukia3b2d692009-04-02 16:57:45 -07002068 id = lookup_swap_cgroup(ent);
2069 rcu_read_lock();
2070 mem = mem_cgroup_lookup(id);
2071 if (mem && !css_tryget(&mem->css))
2072 mem = NULL;
2073 rcu_read_unlock();
Daisuke Nishimura3c776e62009-04-02 16:57:43 -07002074 }
Daisuke Nishimurac0bd3f62009-04-30 15:08:11 -07002075 unlock_page_cgroup(pc);
KAMEZAWA Hiroyukib5a84312009-01-07 18:08:35 -08002076 return mem;
2077}
2078
KAMEZAWA Hiroyuki7a81b882009-01-07 18:07:48 -08002079/*
Daisuke Nishimuraa5e924f2009-01-07 18:08:28 -08002080 * commit a charge got by __mem_cgroup_try_charge() and makes page_cgroup to be
KAMEZAWA Hiroyuki7a81b882009-01-07 18:07:48 -08002081 * USED state. If already USED, uncharge and return.
2082 */
2083
2084static void __mem_cgroup_commit_charge(struct mem_cgroup *mem,
2085 struct page_cgroup *pc,
2086 enum charge_type ctype)
2087{
KAMEZAWA Hiroyuki7a81b882009-01-07 18:07:48 -08002088 /* try_charge() can return NULL to *memcg, taking care of it. */
2089 if (!mem)
2090 return;
KAMEZAWA Hiroyuki52d4b9a2008-10-18 20:28:16 -07002091
2092 lock_page_cgroup(pc);
2093 if (unlikely(PageCgroupUsed(pc))) {
2094 unlock_page_cgroup(pc);
Daisuke Nishimuraa3032a22009-12-15 16:47:10 -08002095 mem_cgroup_cancel_charge(mem);
KAMEZAWA Hiroyuki7a81b882009-01-07 18:07:48 -08002096 return;
KAMEZAWA Hiroyuki52d4b9a2008-10-18 20:28:16 -07002097 }
Balbir Singh4b3bde42009-09-23 15:56:32 -07002098
Balbir Singh8a9f3cc2008-02-07 00:13:53 -08002099 pc->mem_cgroup = mem;
KAMEZAWA Hiroyuki261fb612009-09-23 15:56:33 -07002100 /*
2101 * We access a page_cgroup asynchronously without lock_page_cgroup().
2102 * Especially when a page_cgroup is taken from a page, pc->mem_cgroup
2103 * is accessed after testing USED bit. To make pc->mem_cgroup visible
2104 * before USED bit, we need memory barrier here.
2105 * See mem_cgroup_add_lru_list(), etc.
2106 */
KAMEZAWA Hiroyuki08e552c2009-01-07 18:08:01 -08002107 smp_wmb();
Balbir Singh4b3bde42009-09-23 15:56:32 -07002108 switch (ctype) {
2109 case MEM_CGROUP_CHARGE_TYPE_CACHE:
2110 case MEM_CGROUP_CHARGE_TYPE_SHMEM:
2111 SetPageCgroupCache(pc);
2112 SetPageCgroupUsed(pc);
2113 break;
2114 case MEM_CGROUP_CHARGE_TYPE_MAPPED:
2115 ClearPageCgroupCache(pc);
2116 SetPageCgroupUsed(pc);
2117 break;
2118 default:
2119 break;
2120 }
Hugh Dickins3be91272008-02-07 00:14:19 -08002121
KAMEZAWA Hiroyuki08e552c2009-01-07 18:08:01 -08002122 mem_cgroup_charge_statistics(mem, pc, true);
KAMEZAWA Hiroyuki52d4b9a2008-10-18 20:28:16 -07002123
KAMEZAWA Hiroyuki52d4b9a2008-10-18 20:28:16 -07002124 unlock_page_cgroup(pc);
KAMEZAWA Hiroyuki430e48632010-03-10 15:22:30 -08002125 /*
2126 * "charge_statistics" updated event counter. Then, check it.
2127 * Insert ancestor (and ancestor's ancestors), to softlimit RB-tree.
2128 * if they exceeds softlimit.
2129 */
KAMEZAWA Hiroyukid2265e62010-03-10 15:22:31 -08002130 memcg_check_events(mem, pc->page);
Balbir Singh8a9f3cc2008-02-07 00:13:53 -08002131}
2132
KAMEZAWA Hiroyukif817ed42009-01-07 18:07:53 -08002133/**
Daisuke Nishimura57f9fd7d2009-12-15 16:47:11 -08002134 * __mem_cgroup_move_account - move account of the page
KAMEZAWA Hiroyukif817ed42009-01-07 18:07:53 -08002135 * @pc: page_cgroup of the page.
2136 * @from: mem_cgroup which the page is moved from.
2137 * @to: mem_cgroup which the page is moved to. @from != @to.
Daisuke Nishimura854ffa82010-03-10 15:22:15 -08002138 * @uncharge: whether we should call uncharge and css_put against @from.
KAMEZAWA Hiroyukif817ed42009-01-07 18:07:53 -08002139 *
2140 * The caller must confirm following.
KAMEZAWA Hiroyuki08e552c2009-01-07 18:08:01 -08002141 * - page is not on LRU (isolate_page() is useful.)
Daisuke Nishimura57f9fd7d2009-12-15 16:47:11 -08002142 * - the pc is locked, used, and ->mem_cgroup points to @from.
KAMEZAWA Hiroyukif817ed42009-01-07 18:07:53 -08002143 *
Daisuke Nishimura854ffa82010-03-10 15:22:15 -08002144 * This function doesn't do "charge" nor css_get to new cgroup. It should be
2145 * done by a caller(__mem_cgroup_try_charge would be usefull). If @uncharge is
2146 * true, this function does "uncharge" from old cgroup, but it doesn't if
2147 * @uncharge is false, so a caller should do "uncharge".
KAMEZAWA Hiroyukif817ed42009-01-07 18:07:53 -08002148 */
2149
Daisuke Nishimura57f9fd7d2009-12-15 16:47:11 -08002150static void __mem_cgroup_move_account(struct page_cgroup *pc,
Daisuke Nishimura854ffa82010-03-10 15:22:15 -08002151 struct mem_cgroup *from, struct mem_cgroup *to, bool uncharge)
KAMEZAWA Hiroyukif817ed42009-01-07 18:07:53 -08002152{
KAMEZAWA Hiroyukif817ed42009-01-07 18:07:53 -08002153 VM_BUG_ON(from == to);
KAMEZAWA Hiroyuki08e552c2009-01-07 18:08:01 -08002154 VM_BUG_ON(PageLRU(pc->page));
Daisuke Nishimura57f9fd7d2009-12-15 16:47:11 -08002155 VM_BUG_ON(!PageCgroupLocked(pc));
2156 VM_BUG_ON(!PageCgroupUsed(pc));
2157 VM_BUG_ON(pc->mem_cgroup != from);
KAMEZAWA Hiroyukif817ed42009-01-07 18:07:53 -08002158
KAMEZAWA Hiroyuki8725d542010-04-06 14:35:05 -07002159 if (PageCgroupFileMapped(pc)) {
KAMEZAWA Hiroyukic62b1a32010-03-10 15:22:29 -08002160 /* Update mapped_file data for mem_cgroup */
2161 preempt_disable();
2162 __this_cpu_dec(from->stat->count[MEM_CGROUP_STAT_FILE_MAPPED]);
2163 __this_cpu_inc(to->stat->count[MEM_CGROUP_STAT_FILE_MAPPED]);
2164 preempt_enable();
Balbir Singhd69b0422009-06-17 16:26:34 -07002165 }
Daisuke Nishimura854ffa82010-03-10 15:22:15 -08002166 mem_cgroup_charge_statistics(from, pc, false);
2167 if (uncharge)
2168 /* This is not "cancel", but cancel_charge does all we need. */
2169 mem_cgroup_cancel_charge(from);
Balbir Singhd69b0422009-06-17 16:26:34 -07002170
Daisuke Nishimura854ffa82010-03-10 15:22:15 -08002171 /* caller should have done css_get */
KAMEZAWA Hiroyuki08e552c2009-01-07 18:08:01 -08002172 pc->mem_cgroup = to;
2173 mem_cgroup_charge_statistics(to, pc, true);
KAMEZAWA Hiroyuki88703262009-07-29 15:04:06 -07002174 /*
2175 * We charges against "to" which may not have any tasks. Then, "to"
2176 * can be under rmdir(). But in current implementation, caller of
Daisuke Nishimura4ffef5f2010-03-10 15:22:14 -08002177 * this function is just force_empty() and move charge, so it's
2178 * garanteed that "to" is never removed. So, we don't check rmdir
2179 * status here.
KAMEZAWA Hiroyuki88703262009-07-29 15:04:06 -07002180 */
Daisuke Nishimura57f9fd7d2009-12-15 16:47:11 -08002181}
2182
2183/*
2184 * check whether the @pc is valid for moving account and call
2185 * __mem_cgroup_move_account()
2186 */
2187static int mem_cgroup_move_account(struct page_cgroup *pc,
Daisuke Nishimura854ffa82010-03-10 15:22:15 -08002188 struct mem_cgroup *from, struct mem_cgroup *to, bool uncharge)
Daisuke Nishimura57f9fd7d2009-12-15 16:47:11 -08002189{
2190 int ret = -EINVAL;
2191 lock_page_cgroup(pc);
2192 if (PageCgroupUsed(pc) && pc->mem_cgroup == from) {
Daisuke Nishimura854ffa82010-03-10 15:22:15 -08002193 __mem_cgroup_move_account(pc, from, to, uncharge);
Daisuke Nishimura57f9fd7d2009-12-15 16:47:11 -08002194 ret = 0;
2195 }
2196 unlock_page_cgroup(pc);
KAMEZAWA Hiroyukid2265e62010-03-10 15:22:31 -08002197 /*
2198 * check events
2199 */
2200 memcg_check_events(to, pc->page);
2201 memcg_check_events(from, pc->page);
KAMEZAWA Hiroyukif817ed42009-01-07 18:07:53 -08002202 return ret;
2203}
2204
2205/*
2206 * move charges to its parent.
2207 */
2208
2209static int mem_cgroup_move_parent(struct page_cgroup *pc,
2210 struct mem_cgroup *child,
2211 gfp_t gfp_mask)
2212{
KAMEZAWA Hiroyuki08e552c2009-01-07 18:08:01 -08002213 struct page *page = pc->page;
KAMEZAWA Hiroyukif817ed42009-01-07 18:07:53 -08002214 struct cgroup *cg = child->css.cgroup;
2215 struct cgroup *pcg = cg->parent;
2216 struct mem_cgroup *parent;
KAMEZAWA Hiroyukif817ed42009-01-07 18:07:53 -08002217 int ret;
2218
2219 /* Is ROOT ? */
2220 if (!pcg)
2221 return -EINVAL;
2222
Daisuke Nishimura57f9fd7d2009-12-15 16:47:11 -08002223 ret = -EBUSY;
2224 if (!get_page_unless_zero(page))
2225 goto out;
2226 if (isolate_lru_page(page))
2227 goto put;
KAMEZAWA Hiroyuki08e552c2009-01-07 18:08:01 -08002228
KAMEZAWA Hiroyukif817ed42009-01-07 18:07:53 -08002229 parent = mem_cgroup_from_cont(pcg);
KAMEZAWA Hiroyuki430e48632010-03-10 15:22:30 -08002230 ret = __mem_cgroup_try_charge(NULL, gfp_mask, &parent, false);
KAMEZAWA Hiroyukia636b322009-01-07 18:08:08 -08002231 if (ret || !parent)
Daisuke Nishimura57f9fd7d2009-12-15 16:47:11 -08002232 goto put_back;
KAMEZAWA Hiroyuki08e552c2009-01-07 18:08:01 -08002233
Daisuke Nishimura854ffa82010-03-10 15:22:15 -08002234 ret = mem_cgroup_move_account(pc, child, parent, true);
2235 if (ret)
2236 mem_cgroup_cancel_charge(parent);
Daisuke Nishimura57f9fd7d2009-12-15 16:47:11 -08002237put_back:
KAMEZAWA Hiroyuki08e552c2009-01-07 18:08:01 -08002238 putback_lru_page(page);
Daisuke Nishimura57f9fd7d2009-12-15 16:47:11 -08002239put:
Daisuke Nishimura40d58132009-01-15 13:51:12 -08002240 put_page(page);
Daisuke Nishimura57f9fd7d2009-12-15 16:47:11 -08002241out:
KAMEZAWA Hiroyukif817ed42009-01-07 18:07:53 -08002242 return ret;
2243}
2244
KAMEZAWA Hiroyuki7a81b882009-01-07 18:07:48 -08002245/*
2246 * Charge the memory controller for page usage.
2247 * Return
2248 * 0 if the charge was successful
2249 * < 0 if the cgroup is over its limit
2250 */
2251static int mem_cgroup_charge_common(struct page *page, struct mm_struct *mm,
Daisuke Nishimura73045c42010-08-10 18:02:59 -07002252 gfp_t gfp_mask, enum charge_type ctype)
KAMEZAWA Hiroyuki7a81b882009-01-07 18:07:48 -08002253{
Daisuke Nishimura73045c42010-08-10 18:02:59 -07002254 struct mem_cgroup *mem = NULL;
KAMEZAWA Hiroyuki7a81b882009-01-07 18:07:48 -08002255 struct page_cgroup *pc;
2256 int ret;
2257
2258 pc = lookup_page_cgroup(page);
2259 /* can happen at boot */
2260 if (unlikely(!pc))
2261 return 0;
2262 prefetchw(pc);
2263
KAMEZAWA Hiroyuki430e48632010-03-10 15:22:30 -08002264 ret = __mem_cgroup_try_charge(mm, gfp_mask, &mem, true);
KAMEZAWA Hiroyukia636b322009-01-07 18:08:08 -08002265 if (ret || !mem)
KAMEZAWA Hiroyuki7a81b882009-01-07 18:07:48 -08002266 return ret;
2267
2268 __mem_cgroup_commit_charge(mem, pc, ctype);
2269 return 0;
2270}
2271
2272int mem_cgroup_newpage_charge(struct page *page,
2273 struct mm_struct *mm, gfp_t gfp_mask)
KAMEZAWA Hiroyuki217bc312008-02-07 00:14:17 -08002274{
Hirokazu Takahashif8d665422009-01-07 18:08:02 -08002275 if (mem_cgroup_disabled())
Li Zefancede86a2008-07-25 01:47:18 -07002276 return 0;
KAMEZAWA Hiroyuki52d4b9a2008-10-18 20:28:16 -07002277 if (PageCompound(page))
2278 return 0;
KAMEZAWA Hiroyuki69029cd2008-07-25 01:47:14 -07002279 /*
2280 * If already mapped, we don't have to account.
2281 * If page cache, page->mapping has address_space.
2282 * But page->mapping may have out-of-use anon_vma pointer,
2283 * detecit it by PageAnon() check. newly-mapped-anon's page->mapping
2284 * is NULL.
2285 */
2286 if (page_mapped(page) || (page->mapping && !PageAnon(page)))
2287 return 0;
2288 if (unlikely(!mm))
2289 mm = &init_mm;
KAMEZAWA Hiroyuki217bc312008-02-07 00:14:17 -08002290 return mem_cgroup_charge_common(page, mm, gfp_mask,
Daisuke Nishimura73045c42010-08-10 18:02:59 -07002291 MEM_CGROUP_CHARGE_TYPE_MAPPED);
KAMEZAWA Hiroyuki217bc312008-02-07 00:14:17 -08002292}
2293
Daisuke Nishimura83aae4c2009-04-02 16:57:48 -07002294static void
2295__mem_cgroup_commit_charge_swapin(struct page *page, struct mem_cgroup *ptr,
2296 enum charge_type ctype);
2297
Balbir Singhe1a1cd52008-02-07 00:14:02 -08002298int mem_cgroup_cache_charge(struct page *page, struct mm_struct *mm,
2299 gfp_t gfp_mask)
Balbir Singh8697d332008-02-07 00:13:59 -08002300{
KAMEZAWA Hiroyukib5a84312009-01-07 18:08:35 -08002301 int ret;
2302
Hirokazu Takahashif8d665422009-01-07 18:08:02 -08002303 if (mem_cgroup_disabled())
Li Zefancede86a2008-07-25 01:47:18 -07002304 return 0;
KAMEZAWA Hiroyuki52d4b9a2008-10-18 20:28:16 -07002305 if (PageCompound(page))
2306 return 0;
KAMEZAWA Hiroyukiaccf1632008-07-25 01:47:17 -07002307 /*
2308 * Corner case handling. This is called from add_to_page_cache()
2309 * in usual. But some FS (shmem) precharges this page before calling it
2310 * and call add_to_page_cache() with GFP_NOWAIT.
2311 *
2312 * For GFP_NOWAIT case, the page may be pre-charged before calling
2313 * add_to_page_cache(). (See shmem.c) check it here and avoid to call
2314 * charge twice. (It works but has to pay a bit larger cost.)
KAMEZAWA Hiroyukib5a84312009-01-07 18:08:35 -08002315 * And when the page is SwapCache, it should take swap information
2316 * into account. This is under lock_page() now.
KAMEZAWA Hiroyukiaccf1632008-07-25 01:47:17 -07002317 */
2318 if (!(gfp_mask & __GFP_WAIT)) {
2319 struct page_cgroup *pc;
2320
KAMEZAWA Hiroyuki52d4b9a2008-10-18 20:28:16 -07002321 pc = lookup_page_cgroup(page);
2322 if (!pc)
2323 return 0;
2324 lock_page_cgroup(pc);
2325 if (PageCgroupUsed(pc)) {
2326 unlock_page_cgroup(pc);
KAMEZAWA Hiroyukiaccf1632008-07-25 01:47:17 -07002327 return 0;
2328 }
KAMEZAWA Hiroyuki52d4b9a2008-10-18 20:28:16 -07002329 unlock_page_cgroup(pc);
KAMEZAWA Hiroyukiaccf1632008-07-25 01:47:17 -07002330 }
2331
Daisuke Nishimura73045c42010-08-10 18:02:59 -07002332 if (unlikely(!mm))
Balbir Singh8697d332008-02-07 00:13:59 -08002333 mm = &init_mm;
KAMEZAWA Hiroyukiaccf1632008-07-25 01:47:17 -07002334
KAMEZAWA Hiroyukic05555b2008-10-18 20:28:11 -07002335 if (page_is_file_cache(page))
2336 return mem_cgroup_charge_common(page, mm, gfp_mask,
Daisuke Nishimura73045c42010-08-10 18:02:59 -07002337 MEM_CGROUP_CHARGE_TYPE_CACHE);
KAMEZAWA Hiroyukib5a84312009-01-07 18:08:35 -08002338
Daisuke Nishimura83aae4c2009-04-02 16:57:48 -07002339 /* shmem */
2340 if (PageSwapCache(page)) {
Daisuke Nishimura73045c42010-08-10 18:02:59 -07002341 struct mem_cgroup *mem = NULL;
2342
Daisuke Nishimura83aae4c2009-04-02 16:57:48 -07002343 ret = mem_cgroup_try_charge_swapin(mm, page, gfp_mask, &mem);
2344 if (!ret)
2345 __mem_cgroup_commit_charge_swapin(page, mem,
2346 MEM_CGROUP_CHARGE_TYPE_SHMEM);
2347 } else
2348 ret = mem_cgroup_charge_common(page, mm, gfp_mask,
Daisuke Nishimura73045c42010-08-10 18:02:59 -07002349 MEM_CGROUP_CHARGE_TYPE_SHMEM);
KAMEZAWA Hiroyukib5a84312009-01-07 18:08:35 -08002350
KAMEZAWA Hiroyukib5a84312009-01-07 18:08:35 -08002351 return ret;
KAMEZAWA Hiroyukie8589cc2008-07-25 01:47:10 -07002352}
2353
KAMEZAWA Hiroyuki54595fe2009-01-07 18:08:33 -08002354/*
2355 * While swap-in, try_charge -> commit or cancel, the page is locked.
2356 * And when try_charge() successfully returns, one refcnt to memcg without
Uwe Kleine-König21ae2952009-10-07 15:21:09 +02002357 * struct page_cgroup is acquired. This refcnt will be consumed by
KAMEZAWA Hiroyuki54595fe2009-01-07 18:08:33 -08002358 * "commit()" or removed by "cancel()"
2359 */
KAMEZAWA Hiroyuki8c7c6e342009-01-07 18:08:00 -08002360int mem_cgroup_try_charge_swapin(struct mm_struct *mm,
2361 struct page *page,
2362 gfp_t mask, struct mem_cgroup **ptr)
2363{
2364 struct mem_cgroup *mem;
KAMEZAWA Hiroyuki54595fe2009-01-07 18:08:33 -08002365 int ret;
KAMEZAWA Hiroyuki8c7c6e342009-01-07 18:08:00 -08002366
Hirokazu Takahashif8d665422009-01-07 18:08:02 -08002367 if (mem_cgroup_disabled())
KAMEZAWA Hiroyuki8c7c6e342009-01-07 18:08:00 -08002368 return 0;
2369
2370 if (!do_swap_account)
2371 goto charge_cur_mm;
KAMEZAWA Hiroyuki8c7c6e342009-01-07 18:08:00 -08002372 /*
2373 * A racing thread's fault, or swapoff, may have already updated
Hugh Dickins407f9c82009-12-14 17:59:30 -08002374 * the pte, and even removed page from swap cache: in those cases
2375 * do_swap_page()'s pte_same() test will fail; but there's also a
2376 * KSM case which does need to charge the page.
KAMEZAWA Hiroyuki8c7c6e342009-01-07 18:08:00 -08002377 */
2378 if (!PageSwapCache(page))
Hugh Dickins407f9c82009-12-14 17:59:30 -08002379 goto charge_cur_mm;
Wu Fengguange42d9d52009-12-16 12:19:59 +01002380 mem = try_get_mem_cgroup_from_page(page);
KAMEZAWA Hiroyuki54595fe2009-01-07 18:08:33 -08002381 if (!mem)
2382 goto charge_cur_mm;
KAMEZAWA Hiroyuki8c7c6e342009-01-07 18:08:00 -08002383 *ptr = mem;
KAMEZAWA Hiroyuki430e48632010-03-10 15:22:30 -08002384 ret = __mem_cgroup_try_charge(NULL, mask, ptr, true);
KAMEZAWA Hiroyuki54595fe2009-01-07 18:08:33 -08002385 css_put(&mem->css);
2386 return ret;
KAMEZAWA Hiroyuki8c7c6e342009-01-07 18:08:00 -08002387charge_cur_mm:
2388 if (unlikely(!mm))
2389 mm = &init_mm;
KAMEZAWA Hiroyuki430e48632010-03-10 15:22:30 -08002390 return __mem_cgroup_try_charge(mm, mask, ptr, true);
KAMEZAWA Hiroyuki8c7c6e342009-01-07 18:08:00 -08002391}
2392
Daisuke Nishimura83aae4c2009-04-02 16:57:48 -07002393static void
2394__mem_cgroup_commit_charge_swapin(struct page *page, struct mem_cgroup *ptr,
2395 enum charge_type ctype)
KAMEZAWA Hiroyuki7a81b882009-01-07 18:07:48 -08002396{
2397 struct page_cgroup *pc;
2398
Hirokazu Takahashif8d665422009-01-07 18:08:02 -08002399 if (mem_cgroup_disabled())
KAMEZAWA Hiroyuki7a81b882009-01-07 18:07:48 -08002400 return;
2401 if (!ptr)
2402 return;
KAMEZAWA Hiroyuki88703262009-07-29 15:04:06 -07002403 cgroup_exclude_rmdir(&ptr->css);
KAMEZAWA Hiroyuki7a81b882009-01-07 18:07:48 -08002404 pc = lookup_page_cgroup(page);
KAMEZAWA Hiroyuki544122e2009-01-07 18:08:34 -08002405 mem_cgroup_lru_del_before_commit_swapcache(page);
Daisuke Nishimura83aae4c2009-04-02 16:57:48 -07002406 __mem_cgroup_commit_charge(ptr, pc, ctype);
KAMEZAWA Hiroyuki544122e2009-01-07 18:08:34 -08002407 mem_cgroup_lru_add_after_commit_swapcache(page);
KAMEZAWA Hiroyuki8c7c6e342009-01-07 18:08:00 -08002408 /*
2409 * Now swap is on-memory. This means this page may be
2410 * counted both as mem and swap....double count.
KAMEZAWA Hiroyuki03f3c432009-01-07 18:08:31 -08002411 * Fix it by uncharging from memsw. Basically, this SwapCache is stable
2412 * under lock_page(). But in do_swap_page()::memory.c, reuse_swap_page()
2413 * may call delete_from_swap_cache() before reach here.
KAMEZAWA Hiroyuki8c7c6e342009-01-07 18:08:00 -08002414 */
KAMEZAWA Hiroyuki03f3c432009-01-07 18:08:31 -08002415 if (do_swap_account && PageSwapCache(page)) {
KAMEZAWA Hiroyuki8c7c6e342009-01-07 18:08:00 -08002416 swp_entry_t ent = {.val = page_private(page)};
KAMEZAWA Hiroyukia3b2d692009-04-02 16:57:45 -07002417 unsigned short id;
KAMEZAWA Hiroyuki8c7c6e342009-01-07 18:08:00 -08002418 struct mem_cgroup *memcg;
KAMEZAWA Hiroyukia3b2d692009-04-02 16:57:45 -07002419
2420 id = swap_cgroup_record(ent, 0);
2421 rcu_read_lock();
2422 memcg = mem_cgroup_lookup(id);
KAMEZAWA Hiroyuki8c7c6e342009-01-07 18:08:00 -08002423 if (memcg) {
KAMEZAWA Hiroyukia3b2d692009-04-02 16:57:45 -07002424 /*
2425 * This recorded memcg can be obsolete one. So, avoid
2426 * calling css_tryget
2427 */
Balbir Singh0c3e73e2009-09-23 15:56:42 -07002428 if (!mem_cgroup_is_root(memcg))
KAMEZAWA Hiroyuki4e649152009-10-01 15:44:11 -07002429 res_counter_uncharge(&memcg->memsw, PAGE_SIZE);
Balbir Singh0c3e73e2009-09-23 15:56:42 -07002430 mem_cgroup_swap_statistics(memcg, false);
KAMEZAWA Hiroyuki8c7c6e342009-01-07 18:08:00 -08002431 mem_cgroup_put(memcg);
2432 }
KAMEZAWA Hiroyukia3b2d692009-04-02 16:57:45 -07002433 rcu_read_unlock();
KAMEZAWA Hiroyuki8c7c6e342009-01-07 18:08:00 -08002434 }
KAMEZAWA Hiroyuki88703262009-07-29 15:04:06 -07002435 /*
2436 * At swapin, we may charge account against cgroup which has no tasks.
2437 * So, rmdir()->pre_destroy() can be called while we do this charge.
2438 * In that case, we need to call pre_destroy() again. check it here.
2439 */
2440 cgroup_release_and_wakeup_rmdir(&ptr->css);
KAMEZAWA Hiroyuki7a81b882009-01-07 18:07:48 -08002441}
2442
Daisuke Nishimura83aae4c2009-04-02 16:57:48 -07002443void mem_cgroup_commit_charge_swapin(struct page *page, struct mem_cgroup *ptr)
2444{
2445 __mem_cgroup_commit_charge_swapin(page, ptr,
2446 MEM_CGROUP_CHARGE_TYPE_MAPPED);
2447}
2448
KAMEZAWA Hiroyuki7a81b882009-01-07 18:07:48 -08002449void mem_cgroup_cancel_charge_swapin(struct mem_cgroup *mem)
2450{
Hirokazu Takahashif8d665422009-01-07 18:08:02 -08002451 if (mem_cgroup_disabled())
KAMEZAWA Hiroyuki7a81b882009-01-07 18:07:48 -08002452 return;
2453 if (!mem)
2454 return;
Daisuke Nishimuraa3032a22009-12-15 16:47:10 -08002455 mem_cgroup_cancel_charge(mem);
KAMEZAWA Hiroyuki7a81b882009-01-07 18:07:48 -08002456}
2457
KAMEZAWA Hiroyuki569b8462009-12-15 16:47:03 -08002458static void
2459__do_uncharge(struct mem_cgroup *mem, const enum charge_type ctype)
2460{
2461 struct memcg_batch_info *batch = NULL;
2462 bool uncharge_memsw = true;
2463 /* If swapout, usage of swap doesn't decrease */
2464 if (!do_swap_account || ctype == MEM_CGROUP_CHARGE_TYPE_SWAPOUT)
2465 uncharge_memsw = false;
KAMEZAWA Hiroyuki569b8462009-12-15 16:47:03 -08002466
2467 batch = &current->memcg_batch;
2468 /*
2469 * In usual, we do css_get() when we remember memcg pointer.
2470 * But in this case, we keep res->usage until end of a series of
2471 * uncharges. Then, it's ok to ignore memcg's refcnt.
2472 */
2473 if (!batch->memcg)
2474 batch->memcg = mem;
2475 /*
KAMEZAWA Hiroyuki3c11ecf2010-05-26 14:42:37 -07002476 * do_batch > 0 when unmapping pages or inode invalidate/truncate.
2477 * In those cases, all pages freed continously can be expected to be in
2478 * the same cgroup and we have chance to coalesce uncharges.
2479 * But we do uncharge one by one if this is killed by OOM(TIF_MEMDIE)
2480 * because we want to do uncharge as soon as possible.
2481 */
2482
2483 if (!batch->do_batch || test_thread_flag(TIF_MEMDIE))
2484 goto direct_uncharge;
2485
2486 /*
KAMEZAWA Hiroyuki569b8462009-12-15 16:47:03 -08002487 * In typical case, batch->memcg == mem. This means we can
2488 * merge a series of uncharges to an uncharge of res_counter.
2489 * If not, we uncharge res_counter ony by one.
2490 */
2491 if (batch->memcg != mem)
2492 goto direct_uncharge;
2493 /* remember freed charge and uncharge it later */
2494 batch->bytes += PAGE_SIZE;
2495 if (uncharge_memsw)
2496 batch->memsw_bytes += PAGE_SIZE;
2497 return;
2498direct_uncharge:
2499 res_counter_uncharge(&mem->res, PAGE_SIZE);
2500 if (uncharge_memsw)
2501 res_counter_uncharge(&mem->memsw, PAGE_SIZE);
KAMEZAWA Hiroyuki3c11ecf2010-05-26 14:42:37 -07002502 if (unlikely(batch->memcg != mem))
2503 memcg_oom_recover(mem);
KAMEZAWA Hiroyuki569b8462009-12-15 16:47:03 -08002504 return;
2505}
KAMEZAWA Hiroyuki7a81b882009-01-07 18:07:48 -08002506
Balbir Singh8697d332008-02-07 00:13:59 -08002507/*
KAMEZAWA Hiroyuki69029cd2008-07-25 01:47:14 -07002508 * uncharge if !page_mapped(page)
Balbir Singh8a9f3cc2008-02-07 00:13:53 -08002509 */
KAMEZAWA Hiroyuki8c7c6e342009-01-07 18:08:00 -08002510static struct mem_cgroup *
KAMEZAWA Hiroyuki69029cd2008-07-25 01:47:14 -07002511__mem_cgroup_uncharge_common(struct page *page, enum charge_type ctype)
Balbir Singh8a9f3cc2008-02-07 00:13:53 -08002512{
Hugh Dickins82895462008-03-04 14:29:08 -08002513 struct page_cgroup *pc;
KAMEZAWA Hiroyuki8c7c6e342009-01-07 18:08:00 -08002514 struct mem_cgroup *mem = NULL;
Balbir Singh8a9f3cc2008-02-07 00:13:53 -08002515
Hirokazu Takahashif8d665422009-01-07 18:08:02 -08002516 if (mem_cgroup_disabled())
KAMEZAWA Hiroyuki8c7c6e342009-01-07 18:08:00 -08002517 return NULL;
Balbir Singh40779602008-04-04 14:29:59 -07002518
KAMEZAWA Hiroyukid13d1442009-01-07 18:07:56 -08002519 if (PageSwapCache(page))
KAMEZAWA Hiroyuki8c7c6e342009-01-07 18:08:00 -08002520 return NULL;
KAMEZAWA Hiroyukid13d1442009-01-07 18:07:56 -08002521
Balbir Singh8697d332008-02-07 00:13:59 -08002522 /*
Balbir Singh3c541e12008-02-07 00:14:41 -08002523 * Check if our page_cgroup is valid
Balbir Singh8697d332008-02-07 00:13:59 -08002524 */
KAMEZAWA Hiroyuki52d4b9a2008-10-18 20:28:16 -07002525 pc = lookup_page_cgroup(page);
2526 if (unlikely(!pc || !PageCgroupUsed(pc)))
KAMEZAWA Hiroyuki8c7c6e342009-01-07 18:08:00 -08002527 return NULL;
Balbir Singh8a9f3cc2008-02-07 00:13:53 -08002528
KAMEZAWA Hiroyuki52d4b9a2008-10-18 20:28:16 -07002529 lock_page_cgroup(pc);
KAMEZAWA Hiroyukid13d1442009-01-07 18:07:56 -08002530
KAMEZAWA Hiroyuki8c7c6e342009-01-07 18:08:00 -08002531 mem = pc->mem_cgroup;
2532
KAMEZAWA Hiroyukid13d1442009-01-07 18:07:56 -08002533 if (!PageCgroupUsed(pc))
2534 goto unlock_out;
2535
2536 switch (ctype) {
2537 case MEM_CGROUP_CHARGE_TYPE_MAPPED:
KAMEZAWA Hiroyuki8a9478c2009-06-17 16:27:17 -07002538 case MEM_CGROUP_CHARGE_TYPE_DROP:
akpm@linux-foundation.orgac39cf82010-05-26 14:42:46 -07002539 /* See mem_cgroup_prepare_migration() */
2540 if (page_mapped(page) || PageCgroupMigration(pc))
KAMEZAWA Hiroyukid13d1442009-01-07 18:07:56 -08002541 goto unlock_out;
2542 break;
2543 case MEM_CGROUP_CHARGE_TYPE_SWAPOUT:
2544 if (!PageAnon(page)) { /* Shared memory */
2545 if (page->mapping && !page_is_file_cache(page))
2546 goto unlock_out;
2547 } else if (page_mapped(page)) /* Anon */
2548 goto unlock_out;
2549 break;
2550 default:
2551 break;
KAMEZAWA Hiroyuki52d4b9a2008-10-18 20:28:16 -07002552 }
KAMEZAWA Hiroyukid13d1442009-01-07 18:07:56 -08002553
KAMEZAWA Hiroyuki08e552c2009-01-07 18:08:01 -08002554 mem_cgroup_charge_statistics(mem, pc, false);
KAMEZAWA Hiroyuki04046e12009-04-02 16:57:33 -07002555
KAMEZAWA Hiroyuki52d4b9a2008-10-18 20:28:16 -07002556 ClearPageCgroupUsed(pc);
KAMEZAWA Hiroyuki544122e2009-01-07 18:08:34 -08002557 /*
2558 * pc->mem_cgroup is not cleared here. It will be accessed when it's
2559 * freed from LRU. This is safe because uncharged page is expected not
2560 * to be reused (freed soon). Exception is SwapCache, it's handled by
2561 * special functions.
2562 */
Hugh Dickinsb9c565d2008-03-04 14:29:11 -08002563
KAMEZAWA Hiroyuki52d4b9a2008-10-18 20:28:16 -07002564 unlock_page_cgroup(pc);
KAMEZAWA Hiroyukif75ca962010-08-10 18:03:02 -07002565 /*
2566 * even after unlock, we have mem->res.usage here and this memcg
2567 * will never be freed.
2568 */
KAMEZAWA Hiroyukid2265e62010-03-10 15:22:31 -08002569 memcg_check_events(mem, page);
KAMEZAWA Hiroyukif75ca962010-08-10 18:03:02 -07002570 if (do_swap_account && ctype == MEM_CGROUP_CHARGE_TYPE_SWAPOUT) {
2571 mem_cgroup_swap_statistics(mem, true);
2572 mem_cgroup_get(mem);
2573 }
2574 if (!mem_cgroup_is_root(mem))
2575 __do_uncharge(mem, ctype);
KAMEZAWA Hiroyuki6d12e2d2008-02-07 00:14:31 -08002576
KAMEZAWA Hiroyuki8c7c6e342009-01-07 18:08:00 -08002577 return mem;
KAMEZAWA Hiroyukid13d1442009-01-07 18:07:56 -08002578
2579unlock_out:
2580 unlock_page_cgroup(pc);
KAMEZAWA Hiroyuki8c7c6e342009-01-07 18:08:00 -08002581 return NULL;
Balbir Singh3c541e12008-02-07 00:14:41 -08002582}
2583
KAMEZAWA Hiroyuki69029cd2008-07-25 01:47:14 -07002584void mem_cgroup_uncharge_page(struct page *page)
2585{
KAMEZAWA Hiroyuki52d4b9a2008-10-18 20:28:16 -07002586 /* early check. */
2587 if (page_mapped(page))
2588 return;
2589 if (page->mapping && !PageAnon(page))
2590 return;
KAMEZAWA Hiroyuki69029cd2008-07-25 01:47:14 -07002591 __mem_cgroup_uncharge_common(page, MEM_CGROUP_CHARGE_TYPE_MAPPED);
2592}
2593
2594void mem_cgroup_uncharge_cache_page(struct page *page)
2595{
2596 VM_BUG_ON(page_mapped(page));
KAMEZAWA Hiroyukib7abea92008-10-18 20:28:09 -07002597 VM_BUG_ON(page->mapping);
KAMEZAWA Hiroyuki69029cd2008-07-25 01:47:14 -07002598 __mem_cgroup_uncharge_common(page, MEM_CGROUP_CHARGE_TYPE_CACHE);
2599}
2600
KAMEZAWA Hiroyuki569b8462009-12-15 16:47:03 -08002601/*
2602 * Batch_start/batch_end is called in unmap_page_range/invlidate/trucate.
2603 * In that cases, pages are freed continuously and we can expect pages
2604 * are in the same memcg. All these calls itself limits the number of
2605 * pages freed at once, then uncharge_start/end() is called properly.
2606 * This may be called prural(2) times in a context,
2607 */
2608
2609void mem_cgroup_uncharge_start(void)
2610{
2611 current->memcg_batch.do_batch++;
2612 /* We can do nest. */
2613 if (current->memcg_batch.do_batch == 1) {
2614 current->memcg_batch.memcg = NULL;
2615 current->memcg_batch.bytes = 0;
2616 current->memcg_batch.memsw_bytes = 0;
2617 }
2618}
2619
2620void mem_cgroup_uncharge_end(void)
2621{
2622 struct memcg_batch_info *batch = &current->memcg_batch;
2623
2624 if (!batch->do_batch)
2625 return;
2626
2627 batch->do_batch--;
2628 if (batch->do_batch) /* If stacked, do nothing. */
2629 return;
2630
2631 if (!batch->memcg)
2632 return;
2633 /*
2634 * This "batch->memcg" is valid without any css_get/put etc...
2635 * bacause we hide charges behind us.
2636 */
2637 if (batch->bytes)
2638 res_counter_uncharge(&batch->memcg->res, batch->bytes);
2639 if (batch->memsw_bytes)
2640 res_counter_uncharge(&batch->memcg->memsw, batch->memsw_bytes);
KAMEZAWA Hiroyuki3c11ecf2010-05-26 14:42:37 -07002641 memcg_oom_recover(batch->memcg);
KAMEZAWA Hiroyuki569b8462009-12-15 16:47:03 -08002642 /* forget this pointer (for sanity check) */
2643 batch->memcg = NULL;
2644}
2645
Daisuke Nishimurae767e052009-05-28 14:34:28 -07002646#ifdef CONFIG_SWAP
KAMEZAWA Hiroyuki8c7c6e342009-01-07 18:08:00 -08002647/*
Daisuke Nishimurae767e052009-05-28 14:34:28 -07002648 * called after __delete_from_swap_cache() and drop "page" account.
KAMEZAWA Hiroyuki8c7c6e342009-01-07 18:08:00 -08002649 * memcg information is recorded to swap_cgroup of "ent"
2650 */
KAMEZAWA Hiroyuki8a9478c2009-06-17 16:27:17 -07002651void
2652mem_cgroup_uncharge_swapcache(struct page *page, swp_entry_t ent, bool swapout)
KAMEZAWA Hiroyukid13d1442009-01-07 18:07:56 -08002653{
KAMEZAWA Hiroyuki8c7c6e342009-01-07 18:08:00 -08002654 struct mem_cgroup *memcg;
KAMEZAWA Hiroyuki8a9478c2009-06-17 16:27:17 -07002655 int ctype = MEM_CGROUP_CHARGE_TYPE_SWAPOUT;
KAMEZAWA Hiroyuki8c7c6e342009-01-07 18:08:00 -08002656
KAMEZAWA Hiroyuki8a9478c2009-06-17 16:27:17 -07002657 if (!swapout) /* this was a swap cache but the swap is unused ! */
2658 ctype = MEM_CGROUP_CHARGE_TYPE_DROP;
2659
2660 memcg = __mem_cgroup_uncharge_common(page, ctype);
2661
KAMEZAWA Hiroyukif75ca962010-08-10 18:03:02 -07002662 /*
2663 * record memcg information, if swapout && memcg != NULL,
2664 * mem_cgroup_get() was called in uncharge().
2665 */
2666 if (do_swap_account && swapout && memcg)
KAMEZAWA Hiroyukia3b2d692009-04-02 16:57:45 -07002667 swap_cgroup_record(ent, css_id(&memcg->css));
KAMEZAWA Hiroyukid13d1442009-01-07 18:07:56 -08002668}
Daisuke Nishimurae767e052009-05-28 14:34:28 -07002669#endif
KAMEZAWA Hiroyukid13d1442009-01-07 18:07:56 -08002670
KAMEZAWA Hiroyuki8c7c6e342009-01-07 18:08:00 -08002671#ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP
2672/*
2673 * called from swap_entry_free(). remove record in swap_cgroup and
2674 * uncharge "memsw" account.
2675 */
2676void mem_cgroup_uncharge_swap(swp_entry_t ent)
2677{
2678 struct mem_cgroup *memcg;
KAMEZAWA Hiroyukia3b2d692009-04-02 16:57:45 -07002679 unsigned short id;
KAMEZAWA Hiroyuki8c7c6e342009-01-07 18:08:00 -08002680
2681 if (!do_swap_account)
2682 return;
2683
KAMEZAWA Hiroyukia3b2d692009-04-02 16:57:45 -07002684 id = swap_cgroup_record(ent, 0);
2685 rcu_read_lock();
2686 memcg = mem_cgroup_lookup(id);
KAMEZAWA Hiroyuki8c7c6e342009-01-07 18:08:00 -08002687 if (memcg) {
KAMEZAWA Hiroyukia3b2d692009-04-02 16:57:45 -07002688 /*
2689 * We uncharge this because swap is freed.
2690 * This memcg can be obsolete one. We avoid calling css_tryget
2691 */
Balbir Singh0c3e73e2009-09-23 15:56:42 -07002692 if (!mem_cgroup_is_root(memcg))
KAMEZAWA Hiroyuki4e649152009-10-01 15:44:11 -07002693 res_counter_uncharge(&memcg->memsw, PAGE_SIZE);
Balbir Singh0c3e73e2009-09-23 15:56:42 -07002694 mem_cgroup_swap_statistics(memcg, false);
KAMEZAWA Hiroyuki8c7c6e342009-01-07 18:08:00 -08002695 mem_cgroup_put(memcg);
2696 }
KAMEZAWA Hiroyukia3b2d692009-04-02 16:57:45 -07002697 rcu_read_unlock();
KAMEZAWA Hiroyuki8c7c6e342009-01-07 18:08:00 -08002698}
Daisuke Nishimura02491442010-03-10 15:22:17 -08002699
2700/**
2701 * mem_cgroup_move_swap_account - move swap charge and swap_cgroup's record.
2702 * @entry: swap entry to be moved
2703 * @from: mem_cgroup which the entry is moved from
2704 * @to: mem_cgroup which the entry is moved to
Daisuke Nishimura483c30b2010-03-10 15:22:18 -08002705 * @need_fixup: whether we should fixup res_counters and refcounts.
Daisuke Nishimura02491442010-03-10 15:22:17 -08002706 *
2707 * It succeeds only when the swap_cgroup's record for this entry is the same
2708 * as the mem_cgroup's id of @from.
2709 *
2710 * Returns 0 on success, -EINVAL on failure.
2711 *
2712 * The caller must have charged to @to, IOW, called res_counter_charge() about
2713 * both res and memsw, and called css_get().
2714 */
2715static int mem_cgroup_move_swap_account(swp_entry_t entry,
Daisuke Nishimura483c30b2010-03-10 15:22:18 -08002716 struct mem_cgroup *from, struct mem_cgroup *to, bool need_fixup)
Daisuke Nishimura02491442010-03-10 15:22:17 -08002717{
2718 unsigned short old_id, new_id;
2719
2720 old_id = css_id(&from->css);
2721 new_id = css_id(&to->css);
2722
2723 if (swap_cgroup_cmpxchg(entry, old_id, new_id) == old_id) {
Daisuke Nishimura02491442010-03-10 15:22:17 -08002724 mem_cgroup_swap_statistics(from, false);
Daisuke Nishimura02491442010-03-10 15:22:17 -08002725 mem_cgroup_swap_statistics(to, true);
Daisuke Nishimura483c30b2010-03-10 15:22:18 -08002726 /*
2727 * This function is only called from task migration context now.
2728 * It postpones res_counter and refcount handling till the end
2729 * of task migration(mem_cgroup_clear_mc()) for performance
2730 * improvement. But we cannot postpone mem_cgroup_get(to)
2731 * because if the process that has been moved to @to does
2732 * swap-in, the refcount of @to might be decreased to 0.
2733 */
Daisuke Nishimura02491442010-03-10 15:22:17 -08002734 mem_cgroup_get(to);
Daisuke Nishimura483c30b2010-03-10 15:22:18 -08002735 if (need_fixup) {
2736 if (!mem_cgroup_is_root(from))
2737 res_counter_uncharge(&from->memsw, PAGE_SIZE);
2738 mem_cgroup_put(from);
2739 /*
2740 * we charged both to->res and to->memsw, so we should
2741 * uncharge to->res.
2742 */
2743 if (!mem_cgroup_is_root(to))
2744 res_counter_uncharge(&to->res, PAGE_SIZE);
Daisuke Nishimura483c30b2010-03-10 15:22:18 -08002745 }
Daisuke Nishimura02491442010-03-10 15:22:17 -08002746 return 0;
2747 }
2748 return -EINVAL;
2749}
2750#else
2751static inline int mem_cgroup_move_swap_account(swp_entry_t entry,
Daisuke Nishimura483c30b2010-03-10 15:22:18 -08002752 struct mem_cgroup *from, struct mem_cgroup *to, bool need_fixup)
Daisuke Nishimura02491442010-03-10 15:22:17 -08002753{
2754 return -EINVAL;
2755}
KAMEZAWA Hiroyuki8c7c6e342009-01-07 18:08:00 -08002756#endif
2757
KAMEZAWA Hiroyukiae41be32008-02-07 00:14:10 -08002758/*
KAMEZAWA Hiroyuki01b1ae62009-01-07 18:07:50 -08002759 * Before starting migration, account PAGE_SIZE to mem_cgroup that the old
2760 * page belongs to.
KAMEZAWA Hiroyukiae41be32008-02-07 00:14:10 -08002761 */
akpm@linux-foundation.orgac39cf82010-05-26 14:42:46 -07002762int mem_cgroup_prepare_migration(struct page *page,
2763 struct page *newpage, struct mem_cgroup **ptr)
KAMEZAWA Hiroyukiae41be32008-02-07 00:14:10 -08002764{
2765 struct page_cgroup *pc;
KAMEZAWA Hiroyukie8589cc2008-07-25 01:47:10 -07002766 struct mem_cgroup *mem = NULL;
akpm@linux-foundation.orgac39cf82010-05-26 14:42:46 -07002767 enum charge_type ctype;
KAMEZAWA Hiroyukie8589cc2008-07-25 01:47:10 -07002768 int ret = 0;
Hugh Dickins8869b8f2008-03-04 14:29:09 -08002769
Hirokazu Takahashif8d665422009-01-07 18:08:02 -08002770 if (mem_cgroup_disabled())
Balbir Singh40779602008-04-04 14:29:59 -07002771 return 0;
2772
KAMEZAWA Hiroyuki52d4b9a2008-10-18 20:28:16 -07002773 pc = lookup_page_cgroup(page);
2774 lock_page_cgroup(pc);
2775 if (PageCgroupUsed(pc)) {
KAMEZAWA Hiroyukie8589cc2008-07-25 01:47:10 -07002776 mem = pc->mem_cgroup;
2777 css_get(&mem->css);
akpm@linux-foundation.orgac39cf82010-05-26 14:42:46 -07002778 /*
2779 * At migrating an anonymous page, its mapcount goes down
2780 * to 0 and uncharge() will be called. But, even if it's fully
2781 * unmapped, migration may fail and this page has to be
2782 * charged again. We set MIGRATION flag here and delay uncharge
2783 * until end_migration() is called
2784 *
2785 * Corner Case Thinking
2786 * A)
2787 * When the old page was mapped as Anon and it's unmap-and-freed
2788 * while migration was ongoing.
2789 * If unmap finds the old page, uncharge() of it will be delayed
2790 * until end_migration(). If unmap finds a new page, it's
2791 * uncharged when it make mapcount to be 1->0. If unmap code
2792 * finds swap_migration_entry, the new page will not be mapped
2793 * and end_migration() will find it(mapcount==0).
2794 *
2795 * B)
2796 * When the old page was mapped but migraion fails, the kernel
2797 * remaps it. A charge for it is kept by MIGRATION flag even
2798 * if mapcount goes down to 0. We can do remap successfully
2799 * without charging it again.
2800 *
2801 * C)
2802 * The "old" page is under lock_page() until the end of
2803 * migration, so, the old page itself will not be swapped-out.
2804 * If the new page is swapped out before end_migraton, our
2805 * hook to usual swap-out path will catch the event.
2806 */
2807 if (PageAnon(page))
2808 SetPageCgroupMigration(pc);
Hugh Dickinsb9c565d2008-03-04 14:29:11 -08002809 }
KAMEZAWA Hiroyuki52d4b9a2008-10-18 20:28:16 -07002810 unlock_page_cgroup(pc);
akpm@linux-foundation.orgac39cf82010-05-26 14:42:46 -07002811 /*
2812 * If the page is not charged at this point,
2813 * we return here.
2814 */
2815 if (!mem)
2816 return 0;
KAMEZAWA Hiroyuki01b1ae62009-01-07 18:07:50 -08002817
Andrea Arcangeli93d5c9b2010-04-23 13:17:39 -04002818 *ptr = mem;
akpm@linux-foundation.orgac39cf82010-05-26 14:42:46 -07002819 ret = __mem_cgroup_try_charge(NULL, GFP_KERNEL, ptr, false);
2820 css_put(&mem->css);/* drop extra refcnt */
2821 if (ret || *ptr == NULL) {
2822 if (PageAnon(page)) {
2823 lock_page_cgroup(pc);
2824 ClearPageCgroupMigration(pc);
2825 unlock_page_cgroup(pc);
2826 /*
2827 * The old page may be fully unmapped while we kept it.
2828 */
2829 mem_cgroup_uncharge_page(page);
2830 }
2831 return -ENOMEM;
KAMEZAWA Hiroyukie8589cc2008-07-25 01:47:10 -07002832 }
akpm@linux-foundation.orgac39cf82010-05-26 14:42:46 -07002833 /*
2834 * We charge new page before it's used/mapped. So, even if unlock_page()
2835 * is called before end_migration, we can catch all events on this new
2836 * page. In the case new page is migrated but not remapped, new page's
2837 * mapcount will be finally 0 and we call uncharge in end_migration().
2838 */
2839 pc = lookup_page_cgroup(newpage);
2840 if (PageAnon(page))
2841 ctype = MEM_CGROUP_CHARGE_TYPE_MAPPED;
2842 else if (page_is_file_cache(page))
2843 ctype = MEM_CGROUP_CHARGE_TYPE_CACHE;
2844 else
2845 ctype = MEM_CGROUP_CHARGE_TYPE_SHMEM;
2846 __mem_cgroup_commit_charge(mem, pc, ctype);
KAMEZAWA Hiroyukie8589cc2008-07-25 01:47:10 -07002847 return ret;
2848}
Hugh Dickinsfb59e9f2008-03-04 14:29:16 -08002849
KAMEZAWA Hiroyuki69029cd2008-07-25 01:47:14 -07002850/* remove redundant charge if migration failed*/
KAMEZAWA Hiroyuki01b1ae62009-01-07 18:07:50 -08002851void mem_cgroup_end_migration(struct mem_cgroup *mem,
akpm@linux-foundation.orgac39cf82010-05-26 14:42:46 -07002852 struct page *oldpage, struct page *newpage)
KAMEZAWA Hiroyukie8589cc2008-07-25 01:47:10 -07002853{
akpm@linux-foundation.orgac39cf82010-05-26 14:42:46 -07002854 struct page *used, *unused;
KAMEZAWA Hiroyuki01b1ae62009-01-07 18:07:50 -08002855 struct page_cgroup *pc;
KAMEZAWA Hiroyuki01b1ae62009-01-07 18:07:50 -08002856
2857 if (!mem)
2858 return;
akpm@linux-foundation.orgac39cf82010-05-26 14:42:46 -07002859 /* blocks rmdir() */
KAMEZAWA Hiroyuki88703262009-07-29 15:04:06 -07002860 cgroup_exclude_rmdir(&mem->css);
KAMEZAWA Hiroyuki01b1ae62009-01-07 18:07:50 -08002861 /* at migration success, oldpage->mapping is NULL. */
2862 if (oldpage->mapping) {
akpm@linux-foundation.orgac39cf82010-05-26 14:42:46 -07002863 used = oldpage;
2864 unused = newpage;
KAMEZAWA Hiroyuki01b1ae62009-01-07 18:07:50 -08002865 } else {
akpm@linux-foundation.orgac39cf82010-05-26 14:42:46 -07002866 used = newpage;
KAMEZAWA Hiroyuki01b1ae62009-01-07 18:07:50 -08002867 unused = oldpage;
2868 }
KAMEZAWA Hiroyuki69029cd2008-07-25 01:47:14 -07002869 /*
akpm@linux-foundation.orgac39cf82010-05-26 14:42:46 -07002870 * We disallowed uncharge of pages under migration because mapcount
2871 * of the page goes down to zero, temporarly.
2872 * Clear the flag and check the page should be charged.
KAMEZAWA Hiroyuki69029cd2008-07-25 01:47:14 -07002873 */
akpm@linux-foundation.orgac39cf82010-05-26 14:42:46 -07002874 pc = lookup_page_cgroup(oldpage);
2875 lock_page_cgroup(pc);
2876 ClearPageCgroupMigration(pc);
2877 unlock_page_cgroup(pc);
KAMEZAWA Hiroyuki01b1ae62009-01-07 18:07:50 -08002878
akpm@linux-foundation.orgac39cf82010-05-26 14:42:46 -07002879 __mem_cgroup_uncharge_common(unused, MEM_CGROUP_CHARGE_TYPE_FORCE);
2880
KAMEZAWA Hiroyuki01b1ae62009-01-07 18:07:50 -08002881 /*
akpm@linux-foundation.orgac39cf82010-05-26 14:42:46 -07002882 * If a page is a file cache, radix-tree replacement is very atomic
2883 * and we can skip this check. When it was an Anon page, its mapcount
2884 * goes down to 0. But because we added MIGRATION flage, it's not
2885 * uncharged yet. There are several case but page->mapcount check
2886 * and USED bit check in mem_cgroup_uncharge_page() will do enough
2887 * check. (see prepare_charge() also)
KAMEZAWA Hiroyuki01b1ae62009-01-07 18:07:50 -08002888 */
akpm@linux-foundation.orgac39cf82010-05-26 14:42:46 -07002889 if (PageAnon(used))
2890 mem_cgroup_uncharge_page(used);
KAMEZAWA Hiroyuki88703262009-07-29 15:04:06 -07002891 /*
akpm@linux-foundation.orgac39cf82010-05-26 14:42:46 -07002892 * At migration, we may charge account against cgroup which has no
2893 * tasks.
KAMEZAWA Hiroyuki88703262009-07-29 15:04:06 -07002894 * So, rmdir()->pre_destroy() can be called while we do this charge.
2895 * In that case, we need to call pre_destroy() again. check it here.
2896 */
2897 cgroup_release_and_wakeup_rmdir(&mem->css);
KAMEZAWA Hiroyukiae41be32008-02-07 00:14:10 -08002898}
Pavel Emelianov78fb7462008-02-07 00:13:51 -08002899
KAMEZAWA Hiroyukicc847582008-02-07 00:14:16 -08002900/*
Daisuke Nishimuraae3abae2009-04-30 15:08:19 -07002901 * A call to try to shrink memory usage on charge failure at shmem's swapin.
2902 * Calling hierarchical_reclaim is not enough because we should update
2903 * last_oom_jiffies to prevent pagefault_out_of_memory from invoking global OOM.
2904 * Moreover considering hierarchy, we should reclaim from the mem_over_limit,
2905 * not from the memcg which this page would be charged to.
2906 * try_charge_swapin does all of these works properly.
KAMEZAWA Hiroyukic9b0ed52008-07-25 01:47:15 -07002907 */
Daisuke Nishimuraae3abae2009-04-30 15:08:19 -07002908int mem_cgroup_shmem_charge_fallback(struct page *page,
KAMEZAWA Hiroyukib5a84312009-01-07 18:08:35 -08002909 struct mm_struct *mm,
2910 gfp_t gfp_mask)
KAMEZAWA Hiroyukic9b0ed52008-07-25 01:47:15 -07002911{
KAMEZAWA Hiroyukib5a84312009-01-07 18:08:35 -08002912 struct mem_cgroup *mem = NULL;
Daisuke Nishimuraae3abae2009-04-30 15:08:19 -07002913 int ret;
KAMEZAWA Hiroyukic9b0ed52008-07-25 01:47:15 -07002914
Hirokazu Takahashif8d665422009-01-07 18:08:02 -08002915 if (mem_cgroup_disabled())
Li Zefancede86a2008-07-25 01:47:18 -07002916 return 0;
KAMEZAWA Hiroyukic9b0ed52008-07-25 01:47:15 -07002917
Daisuke Nishimuraae3abae2009-04-30 15:08:19 -07002918 ret = mem_cgroup_try_charge_swapin(mm, page, gfp_mask, &mem);
2919 if (!ret)
2920 mem_cgroup_cancel_charge_swapin(mem); /* it does !mem check */
KAMEZAWA Hiroyukic9b0ed52008-07-25 01:47:15 -07002921
Daisuke Nishimuraae3abae2009-04-30 15:08:19 -07002922 return ret;
KAMEZAWA Hiroyukic9b0ed52008-07-25 01:47:15 -07002923}
2924
KAMEZAWA Hiroyuki8c7c6e342009-01-07 18:08:00 -08002925static DEFINE_MUTEX(set_limit_mutex);
2926
KOSAKI Motohirod38d2a72009-01-06 14:39:44 -08002927static int mem_cgroup_resize_limit(struct mem_cgroup *memcg,
KAMEZAWA Hiroyuki8c7c6e342009-01-07 18:08:00 -08002928 unsigned long long val)
KAMEZAWA Hiroyuki628f4232008-07-25 01:47:20 -07002929{
KAMEZAWA Hiroyuki81d39c22009-04-02 16:57:36 -07002930 int retry_count;
KAMEZAWA Hiroyuki3c11ecf2010-05-26 14:42:37 -07002931 u64 memswlimit, memlimit;
KAMEZAWA Hiroyuki628f4232008-07-25 01:47:20 -07002932 int ret = 0;
KAMEZAWA Hiroyuki81d39c22009-04-02 16:57:36 -07002933 int children = mem_cgroup_count_children(memcg);
2934 u64 curusage, oldusage;
KAMEZAWA Hiroyuki3c11ecf2010-05-26 14:42:37 -07002935 int enlarge;
KAMEZAWA Hiroyuki81d39c22009-04-02 16:57:36 -07002936
2937 /*
2938 * For keeping hierarchical_reclaim simple, how long we should retry
2939 * is depends on callers. We set our retry-count to be function
2940 * of # of children which we should visit in this loop.
2941 */
2942 retry_count = MEM_CGROUP_RECLAIM_RETRIES * children;
2943
2944 oldusage = res_counter_read_u64(&memcg->res, RES_USAGE);
KAMEZAWA Hiroyuki628f4232008-07-25 01:47:20 -07002945
KAMEZAWA Hiroyuki3c11ecf2010-05-26 14:42:37 -07002946 enlarge = 0;
KAMEZAWA Hiroyuki8c7c6e342009-01-07 18:08:00 -08002947 while (retry_count) {
KAMEZAWA Hiroyuki628f4232008-07-25 01:47:20 -07002948 if (signal_pending(current)) {
2949 ret = -EINTR;
2950 break;
2951 }
KAMEZAWA Hiroyuki8c7c6e342009-01-07 18:08:00 -08002952 /*
2953 * Rather than hide all in some function, I do this in
2954 * open coded manner. You see what this really does.
2955 * We have to guarantee mem->res.limit < mem->memsw.limit.
2956 */
2957 mutex_lock(&set_limit_mutex);
2958 memswlimit = res_counter_read_u64(&memcg->memsw, RES_LIMIT);
2959 if (memswlimit < val) {
2960 ret = -EINVAL;
2961 mutex_unlock(&set_limit_mutex);
KAMEZAWA Hiroyuki628f4232008-07-25 01:47:20 -07002962 break;
2963 }
KAMEZAWA Hiroyuki3c11ecf2010-05-26 14:42:37 -07002964
2965 memlimit = res_counter_read_u64(&memcg->res, RES_LIMIT);
2966 if (memlimit < val)
2967 enlarge = 1;
2968
KAMEZAWA Hiroyuki8c7c6e342009-01-07 18:08:00 -08002969 ret = res_counter_set_limit(&memcg->res, val);
KAMEZAWA Hiroyuki22a668d2009-06-17 16:27:19 -07002970 if (!ret) {
2971 if (memswlimit == val)
2972 memcg->memsw_is_minimum = true;
2973 else
2974 memcg->memsw_is_minimum = false;
2975 }
KAMEZAWA Hiroyuki8c7c6e342009-01-07 18:08:00 -08002976 mutex_unlock(&set_limit_mutex);
2977
2978 if (!ret)
2979 break;
2980
Bob Liuaa20d482009-12-15 16:47:14 -08002981 mem_cgroup_hierarchical_reclaim(memcg, NULL, GFP_KERNEL,
Balbir Singh4e416952009-09-23 15:56:39 -07002982 MEM_CGROUP_RECLAIM_SHRINK);
KAMEZAWA Hiroyuki81d39c22009-04-02 16:57:36 -07002983 curusage = res_counter_read_u64(&memcg->res, RES_USAGE);
2984 /* Usage is reduced ? */
2985 if (curusage >= oldusage)
2986 retry_count--;
2987 else
2988 oldusage = curusage;
KAMEZAWA Hiroyuki8c7c6e342009-01-07 18:08:00 -08002989 }
KAMEZAWA Hiroyuki3c11ecf2010-05-26 14:42:37 -07002990 if (!ret && enlarge)
2991 memcg_oom_recover(memcg);
KOSAKI Motohiro14797e22009-01-07 18:08:18 -08002992
KAMEZAWA Hiroyuki8c7c6e342009-01-07 18:08:00 -08002993 return ret;
2994}
2995
Li Zefan338c8432009-06-17 16:27:15 -07002996static int mem_cgroup_resize_memsw_limit(struct mem_cgroup *memcg,
2997 unsigned long long val)
KAMEZAWA Hiroyuki8c7c6e342009-01-07 18:08:00 -08002998{
KAMEZAWA Hiroyuki81d39c22009-04-02 16:57:36 -07002999 int retry_count;
KAMEZAWA Hiroyuki3c11ecf2010-05-26 14:42:37 -07003000 u64 memlimit, memswlimit, oldusage, curusage;
KAMEZAWA Hiroyuki81d39c22009-04-02 16:57:36 -07003001 int children = mem_cgroup_count_children(memcg);
3002 int ret = -EBUSY;
KAMEZAWA Hiroyuki3c11ecf2010-05-26 14:42:37 -07003003 int enlarge = 0;
KAMEZAWA Hiroyuki8c7c6e342009-01-07 18:08:00 -08003004
KAMEZAWA Hiroyuki81d39c22009-04-02 16:57:36 -07003005 /* see mem_cgroup_resize_res_limit */
3006 retry_count = children * MEM_CGROUP_RECLAIM_RETRIES;
3007 oldusage = res_counter_read_u64(&memcg->memsw, RES_USAGE);
KAMEZAWA Hiroyuki8c7c6e342009-01-07 18:08:00 -08003008 while (retry_count) {
3009 if (signal_pending(current)) {
3010 ret = -EINTR;
3011 break;
3012 }
3013 /*
3014 * Rather than hide all in some function, I do this in
3015 * open coded manner. You see what this really does.
3016 * We have to guarantee mem->res.limit < mem->memsw.limit.
3017 */
3018 mutex_lock(&set_limit_mutex);
3019 memlimit = res_counter_read_u64(&memcg->res, RES_LIMIT);
3020 if (memlimit > val) {
3021 ret = -EINVAL;
3022 mutex_unlock(&set_limit_mutex);
3023 break;
3024 }
KAMEZAWA Hiroyuki3c11ecf2010-05-26 14:42:37 -07003025 memswlimit = res_counter_read_u64(&memcg->memsw, RES_LIMIT);
3026 if (memswlimit < val)
3027 enlarge = 1;
KAMEZAWA Hiroyuki8c7c6e342009-01-07 18:08:00 -08003028 ret = res_counter_set_limit(&memcg->memsw, val);
KAMEZAWA Hiroyuki22a668d2009-06-17 16:27:19 -07003029 if (!ret) {
3030 if (memlimit == val)
3031 memcg->memsw_is_minimum = true;
3032 else
3033 memcg->memsw_is_minimum = false;
3034 }
KAMEZAWA Hiroyuki8c7c6e342009-01-07 18:08:00 -08003035 mutex_unlock(&set_limit_mutex);
3036
3037 if (!ret)
3038 break;
3039
Balbir Singh4e416952009-09-23 15:56:39 -07003040 mem_cgroup_hierarchical_reclaim(memcg, NULL, GFP_KERNEL,
Balbir Singh75822b42009-09-23 15:56:38 -07003041 MEM_CGROUP_RECLAIM_NOSWAP |
3042 MEM_CGROUP_RECLAIM_SHRINK);
KAMEZAWA Hiroyuki8c7c6e342009-01-07 18:08:00 -08003043 curusage = res_counter_read_u64(&memcg->memsw, RES_USAGE);
KAMEZAWA Hiroyuki81d39c22009-04-02 16:57:36 -07003044 /* Usage is reduced ? */
KAMEZAWA Hiroyuki8c7c6e342009-01-07 18:08:00 -08003045 if (curusage >= oldusage)
KAMEZAWA Hiroyuki628f4232008-07-25 01:47:20 -07003046 retry_count--;
KAMEZAWA Hiroyuki81d39c22009-04-02 16:57:36 -07003047 else
3048 oldusage = curusage;
KAMEZAWA Hiroyuki628f4232008-07-25 01:47:20 -07003049 }
KAMEZAWA Hiroyuki3c11ecf2010-05-26 14:42:37 -07003050 if (!ret && enlarge)
3051 memcg_oom_recover(memcg);
KAMEZAWA Hiroyuki628f4232008-07-25 01:47:20 -07003052 return ret;
3053}
3054
Balbir Singh4e416952009-09-23 15:56:39 -07003055unsigned long mem_cgroup_soft_limit_reclaim(struct zone *zone, int order,
KOSAKI Motohiro00918b62010-08-10 18:03:05 -07003056 gfp_t gfp_mask)
Balbir Singh4e416952009-09-23 15:56:39 -07003057{
3058 unsigned long nr_reclaimed = 0;
3059 struct mem_cgroup_per_zone *mz, *next_mz = NULL;
3060 unsigned long reclaimed;
3061 int loop = 0;
3062 struct mem_cgroup_tree_per_zone *mctz;
KAMEZAWA Hiroyukief8745c2009-10-01 15:44:12 -07003063 unsigned long long excess;
Balbir Singh4e416952009-09-23 15:56:39 -07003064
3065 if (order > 0)
3066 return 0;
3067
KOSAKI Motohiro00918b62010-08-10 18:03:05 -07003068 mctz = soft_limit_tree_node_zone(zone_to_nid(zone), zone_idx(zone));
Balbir Singh4e416952009-09-23 15:56:39 -07003069 /*
3070 * This loop can run a while, specially if mem_cgroup's continuously
3071 * keep exceeding their soft limit and putting the system under
3072 * pressure
3073 */
3074 do {
3075 if (next_mz)
3076 mz = next_mz;
3077 else
3078 mz = mem_cgroup_largest_soft_limit_node(mctz);
3079 if (!mz)
3080 break;
3081
3082 reclaimed = mem_cgroup_hierarchical_reclaim(mz->mem, zone,
3083 gfp_mask,
3084 MEM_CGROUP_RECLAIM_SOFT);
3085 nr_reclaimed += reclaimed;
3086 spin_lock(&mctz->lock);
3087
3088 /*
3089 * If we failed to reclaim anything from this memory cgroup
3090 * it is time to move on to the next cgroup
3091 */
3092 next_mz = NULL;
3093 if (!reclaimed) {
3094 do {
3095 /*
3096 * Loop until we find yet another one.
3097 *
3098 * By the time we get the soft_limit lock
3099 * again, someone might have aded the
3100 * group back on the RB tree. Iterate to
3101 * make sure we get a different mem.
3102 * mem_cgroup_largest_soft_limit_node returns
3103 * NULL if no other cgroup is present on
3104 * the tree
3105 */
3106 next_mz =
3107 __mem_cgroup_largest_soft_limit_node(mctz);
3108 if (next_mz == mz) {
3109 css_put(&next_mz->mem->css);
3110 next_mz = NULL;
3111 } else /* next_mz == NULL or other memcg */
3112 break;
3113 } while (1);
3114 }
Balbir Singh4e416952009-09-23 15:56:39 -07003115 __mem_cgroup_remove_exceeded(mz->mem, mz, mctz);
KAMEZAWA Hiroyukief8745c2009-10-01 15:44:12 -07003116 excess = res_counter_soft_limit_excess(&mz->mem->res);
Balbir Singh4e416952009-09-23 15:56:39 -07003117 /*
3118 * One school of thought says that we should not add
3119 * back the node to the tree if reclaim returns 0.
3120 * But our reclaim could return 0, simply because due
3121 * to priority we are exposing a smaller subset of
3122 * memory to reclaim from. Consider this as a longer
3123 * term TODO.
3124 */
KAMEZAWA Hiroyukief8745c2009-10-01 15:44:12 -07003125 /* If excess == 0, no tree ops */
3126 __mem_cgroup_insert_exceeded(mz->mem, mz, mctz, excess);
Balbir Singh4e416952009-09-23 15:56:39 -07003127 spin_unlock(&mctz->lock);
3128 css_put(&mz->mem->css);
3129 loop++;
3130 /*
3131 * Could not reclaim anything and there are no more
3132 * mem cgroups to try or we seem to be looping without
3133 * reclaiming anything.
3134 */
3135 if (!nr_reclaimed &&
3136 (next_mz == NULL ||
3137 loop > MEM_CGROUP_MAX_SOFT_LIMIT_RECLAIM_LOOPS))
3138 break;
3139 } while (!nr_reclaimed);
3140 if (next_mz)
3141 css_put(&next_mz->mem->css);
3142 return nr_reclaimed;
3143}
3144
KAMEZAWA Hiroyukic9b0ed52008-07-25 01:47:15 -07003145/*
KAMEZAWA Hiroyukicc847582008-02-07 00:14:16 -08003146 * This routine traverse page_cgroup in given list and drop them all.
KAMEZAWA Hiroyukicc847582008-02-07 00:14:16 -08003147 * *And* this routine doesn't reclaim page itself, just removes page_cgroup.
3148 */
KAMEZAWA Hiroyukif817ed42009-01-07 18:07:53 -08003149static int mem_cgroup_force_empty_list(struct mem_cgroup *mem,
KAMEZAWA Hiroyuki08e552c2009-01-07 18:08:01 -08003150 int node, int zid, enum lru_list lru)
KAMEZAWA Hiroyukicc847582008-02-07 00:14:16 -08003151{
KAMEZAWA Hiroyuki08e552c2009-01-07 18:08:01 -08003152 struct zone *zone;
3153 struct mem_cgroup_per_zone *mz;
KAMEZAWA Hiroyukif817ed42009-01-07 18:07:53 -08003154 struct page_cgroup *pc, *busy;
KAMEZAWA Hiroyuki08e552c2009-01-07 18:08:01 -08003155 unsigned long flags, loop;
KAMEZAWA Hiroyuki072c56c12008-02-07 00:14:39 -08003156 struct list_head *list;
KAMEZAWA Hiroyukif817ed42009-01-07 18:07:53 -08003157 int ret = 0;
KAMEZAWA Hiroyuki072c56c12008-02-07 00:14:39 -08003158
KAMEZAWA Hiroyuki08e552c2009-01-07 18:08:01 -08003159 zone = &NODE_DATA(node)->node_zones[zid];
3160 mz = mem_cgroup_zoneinfo(mem, node, zid);
Christoph Lameterb69408e2008-10-18 20:26:14 -07003161 list = &mz->lists[lru];
KAMEZAWA Hiroyukicc847582008-02-07 00:14:16 -08003162
KAMEZAWA Hiroyukif817ed42009-01-07 18:07:53 -08003163 loop = MEM_CGROUP_ZSTAT(mz, lru);
3164 /* give some margin against EBUSY etc...*/
3165 loop += 256;
3166 busy = NULL;
3167 while (loop--) {
3168 ret = 0;
KAMEZAWA Hiroyuki08e552c2009-01-07 18:08:01 -08003169 spin_lock_irqsave(&zone->lru_lock, flags);
KAMEZAWA Hiroyukif817ed42009-01-07 18:07:53 -08003170 if (list_empty(list)) {
KAMEZAWA Hiroyuki08e552c2009-01-07 18:08:01 -08003171 spin_unlock_irqrestore(&zone->lru_lock, flags);
KAMEZAWA Hiroyuki52d4b9a2008-10-18 20:28:16 -07003172 break;
3173 }
KAMEZAWA Hiroyukif817ed42009-01-07 18:07:53 -08003174 pc = list_entry(list->prev, struct page_cgroup, lru);
3175 if (busy == pc) {
3176 list_move(&pc->lru, list);
Thiago Farina648bcc72010-03-05 13:42:04 -08003177 busy = NULL;
KAMEZAWA Hiroyuki08e552c2009-01-07 18:08:01 -08003178 spin_unlock_irqrestore(&zone->lru_lock, flags);
KAMEZAWA Hiroyukif817ed42009-01-07 18:07:53 -08003179 continue;
3180 }
KAMEZAWA Hiroyuki08e552c2009-01-07 18:08:01 -08003181 spin_unlock_irqrestore(&zone->lru_lock, flags);
KAMEZAWA Hiroyukif817ed42009-01-07 18:07:53 -08003182
KAMEZAWA Hiroyuki2c26fdd2009-01-07 18:08:10 -08003183 ret = mem_cgroup_move_parent(pc, mem, GFP_KERNEL);
KAMEZAWA Hiroyukif817ed42009-01-07 18:07:53 -08003184 if (ret == -ENOMEM)
3185 break;
3186
3187 if (ret == -EBUSY || ret == -EINVAL) {
3188 /* found lock contention or "pc" is obsolete. */
3189 busy = pc;
3190 cond_resched();
3191 } else
3192 busy = NULL;
KAMEZAWA Hiroyukicc847582008-02-07 00:14:16 -08003193 }
KAMEZAWA Hiroyuki08e552c2009-01-07 18:08:01 -08003194
KAMEZAWA Hiroyukif817ed42009-01-07 18:07:53 -08003195 if (!ret && !list_empty(list))
3196 return -EBUSY;
3197 return ret;
KAMEZAWA Hiroyukicc847582008-02-07 00:14:16 -08003198}
3199
3200/*
3201 * make mem_cgroup's charge to be 0 if there is no task.
3202 * This enables deleting this mem_cgroup.
3203 */
KAMEZAWA Hiroyukic1e862c2009-01-07 18:07:55 -08003204static int mem_cgroup_force_empty(struct mem_cgroup *mem, bool free_all)
KAMEZAWA Hiroyukicc847582008-02-07 00:14:16 -08003205{
KAMEZAWA Hiroyukif817ed42009-01-07 18:07:53 -08003206 int ret;
3207 int node, zid, shrink;
3208 int nr_retries = MEM_CGROUP_RECLAIM_RETRIES;
KAMEZAWA Hiroyukic1e862c2009-01-07 18:07:55 -08003209 struct cgroup *cgrp = mem->css.cgroup;
Hugh Dickins8869b8f2008-03-04 14:29:09 -08003210
KAMEZAWA Hiroyukicc847582008-02-07 00:14:16 -08003211 css_get(&mem->css);
KAMEZAWA Hiroyukif817ed42009-01-07 18:07:53 -08003212
3213 shrink = 0;
KAMEZAWA Hiroyukic1e862c2009-01-07 18:07:55 -08003214 /* should free all ? */
3215 if (free_all)
3216 goto try_to_free;
KAMEZAWA Hiroyukif817ed42009-01-07 18:07:53 -08003217move_account:
Daisuke Nishimurafce66472010-01-15 17:01:30 -08003218 do {
KAMEZAWA Hiroyukif817ed42009-01-07 18:07:53 -08003219 ret = -EBUSY;
KAMEZAWA Hiroyukic1e862c2009-01-07 18:07:55 -08003220 if (cgroup_task_count(cgrp) || !list_empty(&cgrp->children))
KAMEZAWA Hiroyukicc847582008-02-07 00:14:16 -08003221 goto out;
KAMEZAWA Hiroyukic1e862c2009-01-07 18:07:55 -08003222 ret = -EINTR;
3223 if (signal_pending(current))
3224 goto out;
KAMEZAWA Hiroyuki52d4b9a2008-10-18 20:28:16 -07003225 /* This is for making all *used* pages to be on LRU. */
3226 lru_add_drain_all();
KAMEZAWA Hiroyukicdec2e42009-12-15 16:47:08 -08003227 drain_all_stock_sync();
KAMEZAWA Hiroyukif817ed42009-01-07 18:07:53 -08003228 ret = 0;
KAMEZAWA Hiroyuki32047e22010-10-27 15:33:40 -07003229 mem_cgroup_start_move(mem);
KAMEZAWA Hiroyuki299b4ea2009-01-29 14:25:17 -08003230 for_each_node_state(node, N_HIGH_MEMORY) {
KAMEZAWA Hiroyukif817ed42009-01-07 18:07:53 -08003231 for (zid = 0; !ret && zid < MAX_NR_ZONES; zid++) {
Christoph Lameterb69408e2008-10-18 20:26:14 -07003232 enum lru_list l;
KAMEZAWA Hiroyukif817ed42009-01-07 18:07:53 -08003233 for_each_lru(l) {
3234 ret = mem_cgroup_force_empty_list(mem,
KAMEZAWA Hiroyuki08e552c2009-01-07 18:08:01 -08003235 node, zid, l);
KAMEZAWA Hiroyukif817ed42009-01-07 18:07:53 -08003236 if (ret)
3237 break;
3238 }
KAMEZAWA Hiroyuki1ecaab22008-02-07 00:14:38 -08003239 }
KAMEZAWA Hiroyukif817ed42009-01-07 18:07:53 -08003240 if (ret)
3241 break;
3242 }
KAMEZAWA Hiroyuki32047e22010-10-27 15:33:40 -07003243 mem_cgroup_end_move(mem);
KAMEZAWA Hiroyuki3c11ecf2010-05-26 14:42:37 -07003244 memcg_oom_recover(mem);
KAMEZAWA Hiroyukif817ed42009-01-07 18:07:53 -08003245 /* it seems parent cgroup doesn't have enough mem */
3246 if (ret == -ENOMEM)
3247 goto try_to_free;
KAMEZAWA Hiroyuki52d4b9a2008-10-18 20:28:16 -07003248 cond_resched();
Daisuke Nishimurafce66472010-01-15 17:01:30 -08003249 /* "ret" should also be checked to ensure all lists are empty. */
3250 } while (mem->res.usage > 0 || ret);
KAMEZAWA Hiroyukicc847582008-02-07 00:14:16 -08003251out:
3252 css_put(&mem->css);
3253 return ret;
KAMEZAWA Hiroyukif817ed42009-01-07 18:07:53 -08003254
3255try_to_free:
KAMEZAWA Hiroyukic1e862c2009-01-07 18:07:55 -08003256 /* returns EBUSY if there is a task or if we come here twice. */
3257 if (cgroup_task_count(cgrp) || !list_empty(&cgrp->children) || shrink) {
KAMEZAWA Hiroyukif817ed42009-01-07 18:07:53 -08003258 ret = -EBUSY;
3259 goto out;
3260 }
KAMEZAWA Hiroyukic1e862c2009-01-07 18:07:55 -08003261 /* we call try-to-free pages for make this cgroup empty */
3262 lru_add_drain_all();
KAMEZAWA Hiroyukif817ed42009-01-07 18:07:53 -08003263 /* try to free all pages in this cgroup */
3264 shrink = 1;
3265 while (nr_retries && mem->res.usage > 0) {
3266 int progress;
KAMEZAWA Hiroyukic1e862c2009-01-07 18:07:55 -08003267
3268 if (signal_pending(current)) {
3269 ret = -EINTR;
3270 goto out;
3271 }
KOSAKI Motohiroa7885eb2009-01-07 18:08:24 -08003272 progress = try_to_free_mem_cgroup_pages(mem, GFP_KERNEL,
3273 false, get_swappiness(mem));
KAMEZAWA Hiroyukic1e862c2009-01-07 18:07:55 -08003274 if (!progress) {
KAMEZAWA Hiroyukif817ed42009-01-07 18:07:53 -08003275 nr_retries--;
KAMEZAWA Hiroyukic1e862c2009-01-07 18:07:55 -08003276 /* maybe some writeback is necessary */
Jens Axboe8aa7e842009-07-09 14:52:32 +02003277 congestion_wait(BLK_RW_ASYNC, HZ/10);
KAMEZAWA Hiroyukic1e862c2009-01-07 18:07:55 -08003278 }
KAMEZAWA Hiroyukif817ed42009-01-07 18:07:53 -08003279
3280 }
KAMEZAWA Hiroyuki08e552c2009-01-07 18:08:01 -08003281 lru_add_drain();
KAMEZAWA Hiroyukif817ed42009-01-07 18:07:53 -08003282 /* try move_account...there may be some *locked* pages. */
Daisuke Nishimurafce66472010-01-15 17:01:30 -08003283 goto move_account;
KAMEZAWA Hiroyukicc847582008-02-07 00:14:16 -08003284}
3285
KAMEZAWA Hiroyukic1e862c2009-01-07 18:07:55 -08003286int mem_cgroup_force_empty_write(struct cgroup *cont, unsigned int event)
3287{
3288 return mem_cgroup_force_empty(mem_cgroup_from_cont(cont), true);
3289}
3290
3291
Balbir Singh18f59ea2009-01-07 18:08:07 -08003292static u64 mem_cgroup_hierarchy_read(struct cgroup *cont, struct cftype *cft)
3293{
3294 return mem_cgroup_from_cont(cont)->use_hierarchy;
3295}
3296
3297static int mem_cgroup_hierarchy_write(struct cgroup *cont, struct cftype *cft,
3298 u64 val)
3299{
3300 int retval = 0;
3301 struct mem_cgroup *mem = mem_cgroup_from_cont(cont);
3302 struct cgroup *parent = cont->parent;
3303 struct mem_cgroup *parent_mem = NULL;
3304
3305 if (parent)
3306 parent_mem = mem_cgroup_from_cont(parent);
3307
3308 cgroup_lock();
3309 /*
André Goddard Rosaaf901ca2009-11-14 13:09:05 -02003310 * If parent's use_hierarchy is set, we can't make any modifications
Balbir Singh18f59ea2009-01-07 18:08:07 -08003311 * in the child subtrees. If it is unset, then the change can
3312 * occur, provided the current cgroup has no children.
3313 *
3314 * For the root cgroup, parent_mem is NULL, we allow value to be
3315 * set if there are no children.
3316 */
3317 if ((!parent_mem || !parent_mem->use_hierarchy) &&
3318 (val == 1 || val == 0)) {
3319 if (list_empty(&cont->children))
3320 mem->use_hierarchy = val;
3321 else
3322 retval = -EBUSY;
3323 } else
3324 retval = -EINVAL;
3325 cgroup_unlock();
3326
3327 return retval;
3328}
3329
Balbir Singh0c3e73e2009-09-23 15:56:42 -07003330
KAMEZAWA Hiroyuki7d74b062010-10-27 15:33:41 -07003331static u64 mem_cgroup_get_recursive_idx_stat(struct mem_cgroup *mem,
3332 enum mem_cgroup_stat_index idx)
Balbir Singh0c3e73e2009-09-23 15:56:42 -07003333{
KAMEZAWA Hiroyuki7d74b062010-10-27 15:33:41 -07003334 struct mem_cgroup *iter;
3335 s64 val = 0;
Balbir Singh0c3e73e2009-09-23 15:56:42 -07003336
KAMEZAWA Hiroyuki7d74b062010-10-27 15:33:41 -07003337 /* each per cpu's value can be minus.Then, use s64 */
3338 for_each_mem_cgroup_tree(iter, mem)
3339 val += mem_cgroup_read_stat(iter, idx);
3340
3341 if (val < 0) /* race ? */
3342 val = 0;
3343 return val;
Balbir Singh0c3e73e2009-09-23 15:56:42 -07003344}
3345
Kirill A. Shutemov104f3922010-03-10 15:22:21 -08003346static inline u64 mem_cgroup_usage(struct mem_cgroup *mem, bool swap)
3347{
KAMEZAWA Hiroyuki7d74b062010-10-27 15:33:41 -07003348 u64 val;
Kirill A. Shutemov104f3922010-03-10 15:22:21 -08003349
3350 if (!mem_cgroup_is_root(mem)) {
3351 if (!swap)
3352 return res_counter_read_u64(&mem->res, RES_USAGE);
3353 else
3354 return res_counter_read_u64(&mem->memsw, RES_USAGE);
3355 }
3356
KAMEZAWA Hiroyuki7d74b062010-10-27 15:33:41 -07003357 val = mem_cgroup_get_recursive_idx_stat(mem, MEM_CGROUP_STAT_CACHE);
3358 val += mem_cgroup_get_recursive_idx_stat(mem, MEM_CGROUP_STAT_RSS);
Kirill A. Shutemov104f3922010-03-10 15:22:21 -08003359
KAMEZAWA Hiroyuki7d74b062010-10-27 15:33:41 -07003360 if (swap)
3361 val += mem_cgroup_get_recursive_idx_stat(mem,
3362 MEM_CGROUP_STAT_SWAPOUT);
Kirill A. Shutemov104f3922010-03-10 15:22:21 -08003363
3364 return val << PAGE_SHIFT;
3365}
3366
Paul Menage2c3daa72008-04-29 00:59:58 -07003367static u64 mem_cgroup_read(struct cgroup *cont, struct cftype *cft)
Balbir Singh8cdea7c2008-02-07 00:13:50 -08003368{
KAMEZAWA Hiroyuki8c7c6e342009-01-07 18:08:00 -08003369 struct mem_cgroup *mem = mem_cgroup_from_cont(cont);
Kirill A. Shutemov104f3922010-03-10 15:22:21 -08003370 u64 val;
KAMEZAWA Hiroyuki8c7c6e342009-01-07 18:08:00 -08003371 int type, name;
3372
3373 type = MEMFILE_TYPE(cft->private);
3374 name = MEMFILE_ATTR(cft->private);
3375 switch (type) {
3376 case _MEM:
Kirill A. Shutemov104f3922010-03-10 15:22:21 -08003377 if (name == RES_USAGE)
3378 val = mem_cgroup_usage(mem, false);
3379 else
Balbir Singh0c3e73e2009-09-23 15:56:42 -07003380 val = res_counter_read_u64(&mem->res, name);
KAMEZAWA Hiroyuki8c7c6e342009-01-07 18:08:00 -08003381 break;
3382 case _MEMSWAP:
Kirill A. Shutemov104f3922010-03-10 15:22:21 -08003383 if (name == RES_USAGE)
3384 val = mem_cgroup_usage(mem, true);
3385 else
Balbir Singh0c3e73e2009-09-23 15:56:42 -07003386 val = res_counter_read_u64(&mem->memsw, name);
KAMEZAWA Hiroyuki8c7c6e342009-01-07 18:08:00 -08003387 break;
3388 default:
3389 BUG();
3390 break;
3391 }
3392 return val;
Balbir Singh8cdea7c2008-02-07 00:13:50 -08003393}
KAMEZAWA Hiroyuki628f4232008-07-25 01:47:20 -07003394/*
3395 * The user of this function is...
3396 * RES_LIMIT.
3397 */
Paul Menage856c13a2008-07-25 01:47:04 -07003398static int mem_cgroup_write(struct cgroup *cont, struct cftype *cft,
3399 const char *buffer)
Balbir Singh8cdea7c2008-02-07 00:13:50 -08003400{
KAMEZAWA Hiroyuki628f4232008-07-25 01:47:20 -07003401 struct mem_cgroup *memcg = mem_cgroup_from_cont(cont);
KAMEZAWA Hiroyuki8c7c6e342009-01-07 18:08:00 -08003402 int type, name;
KAMEZAWA Hiroyuki628f4232008-07-25 01:47:20 -07003403 unsigned long long val;
3404 int ret;
3405
KAMEZAWA Hiroyuki8c7c6e342009-01-07 18:08:00 -08003406 type = MEMFILE_TYPE(cft->private);
3407 name = MEMFILE_ATTR(cft->private);
3408 switch (name) {
KAMEZAWA Hiroyuki628f4232008-07-25 01:47:20 -07003409 case RES_LIMIT:
Balbir Singh4b3bde42009-09-23 15:56:32 -07003410 if (mem_cgroup_is_root(memcg)) { /* Can't set limit on root */
3411 ret = -EINVAL;
3412 break;
3413 }
KAMEZAWA Hiroyuki628f4232008-07-25 01:47:20 -07003414 /* This function does all necessary parse...reuse it */
3415 ret = res_counter_memparse_write_strategy(buffer, &val);
KAMEZAWA Hiroyuki8c7c6e342009-01-07 18:08:00 -08003416 if (ret)
3417 break;
3418 if (type == _MEM)
KAMEZAWA Hiroyuki628f4232008-07-25 01:47:20 -07003419 ret = mem_cgroup_resize_limit(memcg, val);
KAMEZAWA Hiroyuki8c7c6e342009-01-07 18:08:00 -08003420 else
3421 ret = mem_cgroup_resize_memsw_limit(memcg, val);
KAMEZAWA Hiroyuki628f4232008-07-25 01:47:20 -07003422 break;
Balbir Singh296c81d2009-09-23 15:56:36 -07003423 case RES_SOFT_LIMIT:
3424 ret = res_counter_memparse_write_strategy(buffer, &val);
3425 if (ret)
3426 break;
3427 /*
3428 * For memsw, soft limits are hard to implement in terms
3429 * of semantics, for now, we support soft limits for
3430 * control without swap
3431 */
3432 if (type == _MEM)
3433 ret = res_counter_set_soft_limit(&memcg->res, val);
3434 else
3435 ret = -EINVAL;
3436 break;
KAMEZAWA Hiroyuki628f4232008-07-25 01:47:20 -07003437 default:
3438 ret = -EINVAL; /* should be BUG() ? */
3439 break;
3440 }
3441 return ret;
Balbir Singh8cdea7c2008-02-07 00:13:50 -08003442}
3443
KAMEZAWA Hiroyukifee7b542009-01-07 18:08:26 -08003444static void memcg_get_hierarchical_limit(struct mem_cgroup *memcg,
3445 unsigned long long *mem_limit, unsigned long long *memsw_limit)
3446{
3447 struct cgroup *cgroup;
3448 unsigned long long min_limit, min_memsw_limit, tmp;
3449
3450 min_limit = res_counter_read_u64(&memcg->res, RES_LIMIT);
3451 min_memsw_limit = res_counter_read_u64(&memcg->memsw, RES_LIMIT);
3452 cgroup = memcg->css.cgroup;
3453 if (!memcg->use_hierarchy)
3454 goto out;
3455
3456 while (cgroup->parent) {
3457 cgroup = cgroup->parent;
3458 memcg = mem_cgroup_from_cont(cgroup);
3459 if (!memcg->use_hierarchy)
3460 break;
3461 tmp = res_counter_read_u64(&memcg->res, RES_LIMIT);
3462 min_limit = min(min_limit, tmp);
3463 tmp = res_counter_read_u64(&memcg->memsw, RES_LIMIT);
3464 min_memsw_limit = min(min_memsw_limit, tmp);
3465 }
3466out:
3467 *mem_limit = min_limit;
3468 *memsw_limit = min_memsw_limit;
3469 return;
3470}
3471
Pavel Emelyanov29f2a4d2008-04-29 01:00:21 -07003472static int mem_cgroup_reset(struct cgroup *cont, unsigned int event)
Pavel Emelyanovc84872e2008-04-29 01:00:17 -07003473{
3474 struct mem_cgroup *mem;
KAMEZAWA Hiroyuki8c7c6e342009-01-07 18:08:00 -08003475 int type, name;
Pavel Emelyanovc84872e2008-04-29 01:00:17 -07003476
3477 mem = mem_cgroup_from_cont(cont);
KAMEZAWA Hiroyuki8c7c6e342009-01-07 18:08:00 -08003478 type = MEMFILE_TYPE(event);
3479 name = MEMFILE_ATTR(event);
3480 switch (name) {
Pavel Emelyanov29f2a4d2008-04-29 01:00:21 -07003481 case RES_MAX_USAGE:
KAMEZAWA Hiroyuki8c7c6e342009-01-07 18:08:00 -08003482 if (type == _MEM)
3483 res_counter_reset_max(&mem->res);
3484 else
3485 res_counter_reset_max(&mem->memsw);
Pavel Emelyanov29f2a4d2008-04-29 01:00:21 -07003486 break;
3487 case RES_FAILCNT:
KAMEZAWA Hiroyuki8c7c6e342009-01-07 18:08:00 -08003488 if (type == _MEM)
3489 res_counter_reset_failcnt(&mem->res);
3490 else
3491 res_counter_reset_failcnt(&mem->memsw);
Pavel Emelyanov29f2a4d2008-04-29 01:00:21 -07003492 break;
3493 }
Balbir Singhf64c3f52009-09-23 15:56:37 -07003494
Pavel Emelyanov85cc59d2008-04-29 01:00:20 -07003495 return 0;
Pavel Emelyanovc84872e2008-04-29 01:00:17 -07003496}
3497
Daisuke Nishimura7dc74be2010-03-10 15:22:13 -08003498static u64 mem_cgroup_move_charge_read(struct cgroup *cgrp,
3499 struct cftype *cft)
3500{
3501 return mem_cgroup_from_cont(cgrp)->move_charge_at_immigrate;
3502}
3503
Daisuke Nishimura02491442010-03-10 15:22:17 -08003504#ifdef CONFIG_MMU
Daisuke Nishimura7dc74be2010-03-10 15:22:13 -08003505static int mem_cgroup_move_charge_write(struct cgroup *cgrp,
3506 struct cftype *cft, u64 val)
3507{
3508 struct mem_cgroup *mem = mem_cgroup_from_cont(cgrp);
3509
3510 if (val >= (1 << NR_MOVE_TYPE))
3511 return -EINVAL;
3512 /*
3513 * We check this value several times in both in can_attach() and
3514 * attach(), so we need cgroup lock to prevent this value from being
3515 * inconsistent.
3516 */
3517 cgroup_lock();
3518 mem->move_charge_at_immigrate = val;
3519 cgroup_unlock();
3520
3521 return 0;
3522}
Daisuke Nishimura02491442010-03-10 15:22:17 -08003523#else
3524static int mem_cgroup_move_charge_write(struct cgroup *cgrp,
3525 struct cftype *cft, u64 val)
3526{
3527 return -ENOSYS;
3528}
3529#endif
Daisuke Nishimura7dc74be2010-03-10 15:22:13 -08003530
KAMEZAWA Hiroyuki14067bb2009-04-02 16:57:35 -07003531
3532/* For read statistics */
3533enum {
3534 MCS_CACHE,
3535 MCS_RSS,
KAMEZAWA Hiroyukid8046582009-12-15 16:47:09 -08003536 MCS_FILE_MAPPED,
KAMEZAWA Hiroyuki14067bb2009-04-02 16:57:35 -07003537 MCS_PGPGIN,
3538 MCS_PGPGOUT,
Daisuke Nishimura1dd3a272009-09-23 15:56:43 -07003539 MCS_SWAP,
KAMEZAWA Hiroyuki14067bb2009-04-02 16:57:35 -07003540 MCS_INACTIVE_ANON,
3541 MCS_ACTIVE_ANON,
3542 MCS_INACTIVE_FILE,
3543 MCS_ACTIVE_FILE,
3544 MCS_UNEVICTABLE,
3545 NR_MCS_STAT,
KAMEZAWA Hiroyukid2ceb9b2008-02-07 00:14:25 -08003546};
3547
KAMEZAWA Hiroyuki14067bb2009-04-02 16:57:35 -07003548struct mcs_total_stat {
3549 s64 stat[NR_MCS_STAT];
3550};
3551
3552struct {
3553 char *local_name;
3554 char *total_name;
3555} memcg_stat_strings[NR_MCS_STAT] = {
3556 {"cache", "total_cache"},
3557 {"rss", "total_rss"},
Balbir Singhd69b0422009-06-17 16:26:34 -07003558 {"mapped_file", "total_mapped_file"},
KAMEZAWA Hiroyuki14067bb2009-04-02 16:57:35 -07003559 {"pgpgin", "total_pgpgin"},
3560 {"pgpgout", "total_pgpgout"},
Daisuke Nishimura1dd3a272009-09-23 15:56:43 -07003561 {"swap", "total_swap"},
KAMEZAWA Hiroyuki14067bb2009-04-02 16:57:35 -07003562 {"inactive_anon", "total_inactive_anon"},
3563 {"active_anon", "total_active_anon"},
3564 {"inactive_file", "total_inactive_file"},
3565 {"active_file", "total_active_file"},
3566 {"unevictable", "total_unevictable"}
3567};
3568
3569
KAMEZAWA Hiroyuki7d74b062010-10-27 15:33:41 -07003570static void
3571mem_cgroup_get_local_stat(struct mem_cgroup *mem, struct mcs_total_stat *s)
KAMEZAWA Hiroyuki14067bb2009-04-02 16:57:35 -07003572{
KAMEZAWA Hiroyuki14067bb2009-04-02 16:57:35 -07003573 s64 val;
3574
3575 /* per cpu stat */
KAMEZAWA Hiroyukic62b1a32010-03-10 15:22:29 -08003576 val = mem_cgroup_read_stat(mem, MEM_CGROUP_STAT_CACHE);
KAMEZAWA Hiroyuki14067bb2009-04-02 16:57:35 -07003577 s->stat[MCS_CACHE] += val * PAGE_SIZE;
KAMEZAWA Hiroyukic62b1a32010-03-10 15:22:29 -08003578 val = mem_cgroup_read_stat(mem, MEM_CGROUP_STAT_RSS);
KAMEZAWA Hiroyuki14067bb2009-04-02 16:57:35 -07003579 s->stat[MCS_RSS] += val * PAGE_SIZE;
KAMEZAWA Hiroyukic62b1a32010-03-10 15:22:29 -08003580 val = mem_cgroup_read_stat(mem, MEM_CGROUP_STAT_FILE_MAPPED);
KAMEZAWA Hiroyukid8046582009-12-15 16:47:09 -08003581 s->stat[MCS_FILE_MAPPED] += val * PAGE_SIZE;
KAMEZAWA Hiroyukic62b1a32010-03-10 15:22:29 -08003582 val = mem_cgroup_read_stat(mem, MEM_CGROUP_STAT_PGPGIN_COUNT);
KAMEZAWA Hiroyuki14067bb2009-04-02 16:57:35 -07003583 s->stat[MCS_PGPGIN] += val;
KAMEZAWA Hiroyukic62b1a32010-03-10 15:22:29 -08003584 val = mem_cgroup_read_stat(mem, MEM_CGROUP_STAT_PGPGOUT_COUNT);
KAMEZAWA Hiroyuki14067bb2009-04-02 16:57:35 -07003585 s->stat[MCS_PGPGOUT] += val;
Daisuke Nishimura1dd3a272009-09-23 15:56:43 -07003586 if (do_swap_account) {
KAMEZAWA Hiroyukic62b1a32010-03-10 15:22:29 -08003587 val = mem_cgroup_read_stat(mem, MEM_CGROUP_STAT_SWAPOUT);
Daisuke Nishimura1dd3a272009-09-23 15:56:43 -07003588 s->stat[MCS_SWAP] += val * PAGE_SIZE;
3589 }
KAMEZAWA Hiroyuki14067bb2009-04-02 16:57:35 -07003590
3591 /* per zone stat */
3592 val = mem_cgroup_get_local_zonestat(mem, LRU_INACTIVE_ANON);
3593 s->stat[MCS_INACTIVE_ANON] += val * PAGE_SIZE;
3594 val = mem_cgroup_get_local_zonestat(mem, LRU_ACTIVE_ANON);
3595 s->stat[MCS_ACTIVE_ANON] += val * PAGE_SIZE;
3596 val = mem_cgroup_get_local_zonestat(mem, LRU_INACTIVE_FILE);
3597 s->stat[MCS_INACTIVE_FILE] += val * PAGE_SIZE;
3598 val = mem_cgroup_get_local_zonestat(mem, LRU_ACTIVE_FILE);
3599 s->stat[MCS_ACTIVE_FILE] += val * PAGE_SIZE;
3600 val = mem_cgroup_get_local_zonestat(mem, LRU_UNEVICTABLE);
3601 s->stat[MCS_UNEVICTABLE] += val * PAGE_SIZE;
KAMEZAWA Hiroyuki14067bb2009-04-02 16:57:35 -07003602}
3603
3604static void
3605mem_cgroup_get_total_stat(struct mem_cgroup *mem, struct mcs_total_stat *s)
3606{
KAMEZAWA Hiroyuki7d74b062010-10-27 15:33:41 -07003607 struct mem_cgroup *iter;
3608
3609 for_each_mem_cgroup_tree(iter, mem)
3610 mem_cgroup_get_local_stat(iter, s);
KAMEZAWA Hiroyuki14067bb2009-04-02 16:57:35 -07003611}
3612
Paul Menagec64745c2008-04-29 01:00:02 -07003613static int mem_control_stat_show(struct cgroup *cont, struct cftype *cft,
3614 struct cgroup_map_cb *cb)
KAMEZAWA Hiroyukid2ceb9b2008-02-07 00:14:25 -08003615{
KAMEZAWA Hiroyukid2ceb9b2008-02-07 00:14:25 -08003616 struct mem_cgroup *mem_cont = mem_cgroup_from_cont(cont);
KAMEZAWA Hiroyuki14067bb2009-04-02 16:57:35 -07003617 struct mcs_total_stat mystat;
KAMEZAWA Hiroyukid2ceb9b2008-02-07 00:14:25 -08003618 int i;
3619
KAMEZAWA Hiroyuki14067bb2009-04-02 16:57:35 -07003620 memset(&mystat, 0, sizeof(mystat));
3621 mem_cgroup_get_local_stat(mem_cont, &mystat);
KAMEZAWA Hiroyukid2ceb9b2008-02-07 00:14:25 -08003622
Daisuke Nishimura1dd3a272009-09-23 15:56:43 -07003623 for (i = 0; i < NR_MCS_STAT; i++) {
3624 if (i == MCS_SWAP && !do_swap_account)
3625 continue;
KAMEZAWA Hiroyuki14067bb2009-04-02 16:57:35 -07003626 cb->fill(cb, memcg_stat_strings[i].local_name, mystat.stat[i]);
Daisuke Nishimura1dd3a272009-09-23 15:56:43 -07003627 }
KAMEZAWA Hiroyuki6d12e2d2008-02-07 00:14:31 -08003628
KAMEZAWA Hiroyuki14067bb2009-04-02 16:57:35 -07003629 /* Hierarchical information */
KAMEZAWA Hiroyukifee7b542009-01-07 18:08:26 -08003630 {
3631 unsigned long long limit, memsw_limit;
3632 memcg_get_hierarchical_limit(mem_cont, &limit, &memsw_limit);
3633 cb->fill(cb, "hierarchical_memory_limit", limit);
3634 if (do_swap_account)
3635 cb->fill(cb, "hierarchical_memsw_limit", memsw_limit);
3636 }
KOSAKI Motohiro7f016ee2009-01-07 18:08:22 -08003637
KAMEZAWA Hiroyuki14067bb2009-04-02 16:57:35 -07003638 memset(&mystat, 0, sizeof(mystat));
3639 mem_cgroup_get_total_stat(mem_cont, &mystat);
Daisuke Nishimura1dd3a272009-09-23 15:56:43 -07003640 for (i = 0; i < NR_MCS_STAT; i++) {
3641 if (i == MCS_SWAP && !do_swap_account)
3642 continue;
KAMEZAWA Hiroyuki14067bb2009-04-02 16:57:35 -07003643 cb->fill(cb, memcg_stat_strings[i].total_name, mystat.stat[i]);
Daisuke Nishimura1dd3a272009-09-23 15:56:43 -07003644 }
KAMEZAWA Hiroyuki14067bb2009-04-02 16:57:35 -07003645
KOSAKI Motohiro7f016ee2009-01-07 18:08:22 -08003646#ifdef CONFIG_DEBUG_VM
KOSAKI Motohiroc772be92009-01-07 18:08:25 -08003647 cb->fill(cb, "inactive_ratio", calc_inactive_ratio(mem_cont, NULL));
KOSAKI Motohiro7f016ee2009-01-07 18:08:22 -08003648
3649 {
3650 int nid, zid;
3651 struct mem_cgroup_per_zone *mz;
3652 unsigned long recent_rotated[2] = {0, 0};
3653 unsigned long recent_scanned[2] = {0, 0};
3654
3655 for_each_online_node(nid)
3656 for (zid = 0; zid < MAX_NR_ZONES; zid++) {
3657 mz = mem_cgroup_zoneinfo(mem_cont, nid, zid);
3658
3659 recent_rotated[0] +=
3660 mz->reclaim_stat.recent_rotated[0];
3661 recent_rotated[1] +=
3662 mz->reclaim_stat.recent_rotated[1];
3663 recent_scanned[0] +=
3664 mz->reclaim_stat.recent_scanned[0];
3665 recent_scanned[1] +=
3666 mz->reclaim_stat.recent_scanned[1];
3667 }
3668 cb->fill(cb, "recent_rotated_anon", recent_rotated[0]);
3669 cb->fill(cb, "recent_rotated_file", recent_rotated[1]);
3670 cb->fill(cb, "recent_scanned_anon", recent_scanned[0]);
3671 cb->fill(cb, "recent_scanned_file", recent_scanned[1]);
3672 }
3673#endif
3674
KAMEZAWA Hiroyukid2ceb9b2008-02-07 00:14:25 -08003675 return 0;
3676}
3677
KOSAKI Motohiroa7885eb2009-01-07 18:08:24 -08003678static u64 mem_cgroup_swappiness_read(struct cgroup *cgrp, struct cftype *cft)
3679{
3680 struct mem_cgroup *memcg = mem_cgroup_from_cont(cgrp);
3681
3682 return get_swappiness(memcg);
3683}
3684
3685static int mem_cgroup_swappiness_write(struct cgroup *cgrp, struct cftype *cft,
3686 u64 val)
3687{
3688 struct mem_cgroup *memcg = mem_cgroup_from_cont(cgrp);
3689 struct mem_cgroup *parent;
Li Zefan068b38c2009-01-15 13:51:26 -08003690
KOSAKI Motohiroa7885eb2009-01-07 18:08:24 -08003691 if (val > 100)
3692 return -EINVAL;
3693
3694 if (cgrp->parent == NULL)
3695 return -EINVAL;
3696
3697 parent = mem_cgroup_from_cont(cgrp->parent);
Li Zefan068b38c2009-01-15 13:51:26 -08003698
3699 cgroup_lock();
3700
KOSAKI Motohiroa7885eb2009-01-07 18:08:24 -08003701 /* If under hierarchy, only empty-root can set this value */
3702 if ((parent->use_hierarchy) ||
Li Zefan068b38c2009-01-15 13:51:26 -08003703 (memcg->use_hierarchy && !list_empty(&cgrp->children))) {
3704 cgroup_unlock();
KOSAKI Motohiroa7885eb2009-01-07 18:08:24 -08003705 return -EINVAL;
Li Zefan068b38c2009-01-15 13:51:26 -08003706 }
KOSAKI Motohiroa7885eb2009-01-07 18:08:24 -08003707
3708 spin_lock(&memcg->reclaim_param_lock);
3709 memcg->swappiness = val;
3710 spin_unlock(&memcg->reclaim_param_lock);
3711
Li Zefan068b38c2009-01-15 13:51:26 -08003712 cgroup_unlock();
3713
KOSAKI Motohiroa7885eb2009-01-07 18:08:24 -08003714 return 0;
3715}
3716
Kirill A. Shutemov2e72b632010-03-10 15:22:24 -08003717static void __mem_cgroup_threshold(struct mem_cgroup *memcg, bool swap)
3718{
3719 struct mem_cgroup_threshold_ary *t;
3720 u64 usage;
3721 int i;
3722
3723 rcu_read_lock();
3724 if (!swap)
Kirill A. Shutemov2c488db2010-05-26 14:42:47 -07003725 t = rcu_dereference(memcg->thresholds.primary);
Kirill A. Shutemov2e72b632010-03-10 15:22:24 -08003726 else
Kirill A. Shutemov2c488db2010-05-26 14:42:47 -07003727 t = rcu_dereference(memcg->memsw_thresholds.primary);
Kirill A. Shutemov2e72b632010-03-10 15:22:24 -08003728
3729 if (!t)
3730 goto unlock;
3731
3732 usage = mem_cgroup_usage(memcg, swap);
3733
3734 /*
3735 * current_threshold points to threshold just below usage.
3736 * If it's not true, a threshold was crossed after last
3737 * call of __mem_cgroup_threshold().
3738 */
Phil Carmody5407a562010-05-26 14:42:42 -07003739 i = t->current_threshold;
Kirill A. Shutemov2e72b632010-03-10 15:22:24 -08003740
3741 /*
3742 * Iterate backward over array of thresholds starting from
3743 * current_threshold and check if a threshold is crossed.
3744 * If none of thresholds below usage is crossed, we read
3745 * only one element of the array here.
3746 */
3747 for (; i >= 0 && unlikely(t->entries[i].threshold > usage); i--)
3748 eventfd_signal(t->entries[i].eventfd, 1);
3749
3750 /* i = current_threshold + 1 */
3751 i++;
3752
3753 /*
3754 * Iterate forward over array of thresholds starting from
3755 * current_threshold+1 and check if a threshold is crossed.
3756 * If none of thresholds above usage is crossed, we read
3757 * only one element of the array here.
3758 */
3759 for (; i < t->size && unlikely(t->entries[i].threshold <= usage); i++)
3760 eventfd_signal(t->entries[i].eventfd, 1);
3761
3762 /* Update current_threshold */
Phil Carmody5407a562010-05-26 14:42:42 -07003763 t->current_threshold = i - 1;
Kirill A. Shutemov2e72b632010-03-10 15:22:24 -08003764unlock:
3765 rcu_read_unlock();
3766}
3767
3768static void mem_cgroup_threshold(struct mem_cgroup *memcg)
3769{
Kirill A. Shutemovad4ca5f2010-10-07 12:59:27 -07003770 while (memcg) {
3771 __mem_cgroup_threshold(memcg, false);
3772 if (do_swap_account)
3773 __mem_cgroup_threshold(memcg, true);
3774
3775 memcg = parent_mem_cgroup(memcg);
3776 }
Kirill A. Shutemov2e72b632010-03-10 15:22:24 -08003777}
3778
3779static int compare_thresholds(const void *a, const void *b)
3780{
3781 const struct mem_cgroup_threshold *_a = a;
3782 const struct mem_cgroup_threshold *_b = b;
3783
3784 return _a->threshold - _b->threshold;
3785}
3786
KAMEZAWA Hiroyuki7d74b062010-10-27 15:33:41 -07003787static int mem_cgroup_oom_notify_cb(struct mem_cgroup *mem)
KAMEZAWA Hiroyuki9490ff22010-05-26 14:42:36 -07003788{
3789 struct mem_cgroup_eventfd_list *ev;
3790
3791 list_for_each_entry(ev, &mem->oom_notify, list)
3792 eventfd_signal(ev->eventfd, 1);
3793 return 0;
3794}
3795
3796static void mem_cgroup_oom_notify(struct mem_cgroup *mem)
3797{
KAMEZAWA Hiroyuki7d74b062010-10-27 15:33:41 -07003798 struct mem_cgroup *iter;
3799
3800 for_each_mem_cgroup_tree(iter, mem)
3801 mem_cgroup_oom_notify_cb(iter);
KAMEZAWA Hiroyuki9490ff22010-05-26 14:42:36 -07003802}
3803
3804static int mem_cgroup_usage_register_event(struct cgroup *cgrp,
3805 struct cftype *cft, struct eventfd_ctx *eventfd, const char *args)
Kirill A. Shutemov2e72b632010-03-10 15:22:24 -08003806{
3807 struct mem_cgroup *memcg = mem_cgroup_from_cont(cgrp);
Kirill A. Shutemov2c488db2010-05-26 14:42:47 -07003808 struct mem_cgroup_thresholds *thresholds;
3809 struct mem_cgroup_threshold_ary *new;
Kirill A. Shutemov2e72b632010-03-10 15:22:24 -08003810 int type = MEMFILE_TYPE(cft->private);
3811 u64 threshold, usage;
Kirill A. Shutemov2c488db2010-05-26 14:42:47 -07003812 int i, size, ret;
Kirill A. Shutemov2e72b632010-03-10 15:22:24 -08003813
3814 ret = res_counter_memparse_write_strategy(args, &threshold);
3815 if (ret)
3816 return ret;
3817
3818 mutex_lock(&memcg->thresholds_lock);
Kirill A. Shutemov2c488db2010-05-26 14:42:47 -07003819
Kirill A. Shutemov2e72b632010-03-10 15:22:24 -08003820 if (type == _MEM)
Kirill A. Shutemov2c488db2010-05-26 14:42:47 -07003821 thresholds = &memcg->thresholds;
Kirill A. Shutemov2e72b632010-03-10 15:22:24 -08003822 else if (type == _MEMSWAP)
Kirill A. Shutemov2c488db2010-05-26 14:42:47 -07003823 thresholds = &memcg->memsw_thresholds;
Kirill A. Shutemov2e72b632010-03-10 15:22:24 -08003824 else
3825 BUG();
3826
3827 usage = mem_cgroup_usage(memcg, type == _MEMSWAP);
3828
3829 /* Check if a threshold crossed before adding a new one */
Kirill A. Shutemov2c488db2010-05-26 14:42:47 -07003830 if (thresholds->primary)
Kirill A. Shutemov2e72b632010-03-10 15:22:24 -08003831 __mem_cgroup_threshold(memcg, type == _MEMSWAP);
3832
Kirill A. Shutemov2c488db2010-05-26 14:42:47 -07003833 size = thresholds->primary ? thresholds->primary->size + 1 : 1;
Kirill A. Shutemov2e72b632010-03-10 15:22:24 -08003834
3835 /* Allocate memory for new array of thresholds */
Kirill A. Shutemov2c488db2010-05-26 14:42:47 -07003836 new = kmalloc(sizeof(*new) + size * sizeof(struct mem_cgroup_threshold),
Kirill A. Shutemov2e72b632010-03-10 15:22:24 -08003837 GFP_KERNEL);
Kirill A. Shutemov2c488db2010-05-26 14:42:47 -07003838 if (!new) {
Kirill A. Shutemov2e72b632010-03-10 15:22:24 -08003839 ret = -ENOMEM;
3840 goto unlock;
3841 }
Kirill A. Shutemov2c488db2010-05-26 14:42:47 -07003842 new->size = size;
Kirill A. Shutemov2e72b632010-03-10 15:22:24 -08003843
3844 /* Copy thresholds (if any) to new array */
Kirill A. Shutemov2c488db2010-05-26 14:42:47 -07003845 if (thresholds->primary) {
3846 memcpy(new->entries, thresholds->primary->entries, (size - 1) *
Kirill A. Shutemov2e72b632010-03-10 15:22:24 -08003847 sizeof(struct mem_cgroup_threshold));
Kirill A. Shutemov2c488db2010-05-26 14:42:47 -07003848 }
3849
Kirill A. Shutemov2e72b632010-03-10 15:22:24 -08003850 /* Add new threshold */
Kirill A. Shutemov2c488db2010-05-26 14:42:47 -07003851 new->entries[size - 1].eventfd = eventfd;
3852 new->entries[size - 1].threshold = threshold;
Kirill A. Shutemov2e72b632010-03-10 15:22:24 -08003853
3854 /* Sort thresholds. Registering of new threshold isn't time-critical */
Kirill A. Shutemov2c488db2010-05-26 14:42:47 -07003855 sort(new->entries, size, sizeof(struct mem_cgroup_threshold),
Kirill A. Shutemov2e72b632010-03-10 15:22:24 -08003856 compare_thresholds, NULL);
3857
3858 /* Find current threshold */
Kirill A. Shutemov2c488db2010-05-26 14:42:47 -07003859 new->current_threshold = -1;
Kirill A. Shutemov2e72b632010-03-10 15:22:24 -08003860 for (i = 0; i < size; i++) {
Kirill A. Shutemov2c488db2010-05-26 14:42:47 -07003861 if (new->entries[i].threshold < usage) {
Kirill A. Shutemov2e72b632010-03-10 15:22:24 -08003862 /*
Kirill A. Shutemov2c488db2010-05-26 14:42:47 -07003863 * new->current_threshold will not be used until
3864 * rcu_assign_pointer(), so it's safe to increment
Kirill A. Shutemov2e72b632010-03-10 15:22:24 -08003865 * it here.
3866 */
Kirill A. Shutemov2c488db2010-05-26 14:42:47 -07003867 ++new->current_threshold;
Kirill A. Shutemov2e72b632010-03-10 15:22:24 -08003868 }
3869 }
3870
Kirill A. Shutemov2c488db2010-05-26 14:42:47 -07003871 /* Free old spare buffer and save old primary buffer as spare */
3872 kfree(thresholds->spare);
3873 thresholds->spare = thresholds->primary;
3874
3875 rcu_assign_pointer(thresholds->primary, new);
Kirill A. Shutemov2e72b632010-03-10 15:22:24 -08003876
Kirill A. Shutemov907860e2010-05-26 14:42:46 -07003877 /* To be sure that nobody uses thresholds */
Kirill A. Shutemov2e72b632010-03-10 15:22:24 -08003878 synchronize_rcu();
3879
Kirill A. Shutemov2e72b632010-03-10 15:22:24 -08003880unlock:
3881 mutex_unlock(&memcg->thresholds_lock);
3882
3883 return ret;
3884}
3885
Kirill A. Shutemov907860e2010-05-26 14:42:46 -07003886static void mem_cgroup_usage_unregister_event(struct cgroup *cgrp,
KAMEZAWA Hiroyuki9490ff22010-05-26 14:42:36 -07003887 struct cftype *cft, struct eventfd_ctx *eventfd)
Kirill A. Shutemov2e72b632010-03-10 15:22:24 -08003888{
3889 struct mem_cgroup *memcg = mem_cgroup_from_cont(cgrp);
Kirill A. Shutemov2c488db2010-05-26 14:42:47 -07003890 struct mem_cgroup_thresholds *thresholds;
3891 struct mem_cgroup_threshold_ary *new;
Kirill A. Shutemov2e72b632010-03-10 15:22:24 -08003892 int type = MEMFILE_TYPE(cft->private);
3893 u64 usage;
Kirill A. Shutemov2c488db2010-05-26 14:42:47 -07003894 int i, j, size;
Kirill A. Shutemov2e72b632010-03-10 15:22:24 -08003895
3896 mutex_lock(&memcg->thresholds_lock);
3897 if (type == _MEM)
Kirill A. Shutemov2c488db2010-05-26 14:42:47 -07003898 thresholds = &memcg->thresholds;
Kirill A. Shutemov2e72b632010-03-10 15:22:24 -08003899 else if (type == _MEMSWAP)
Kirill A. Shutemov2c488db2010-05-26 14:42:47 -07003900 thresholds = &memcg->memsw_thresholds;
Kirill A. Shutemov2e72b632010-03-10 15:22:24 -08003901 else
3902 BUG();
3903
3904 /*
3905 * Something went wrong if we trying to unregister a threshold
3906 * if we don't have thresholds
3907 */
3908 BUG_ON(!thresholds);
3909
3910 usage = mem_cgroup_usage(memcg, type == _MEMSWAP);
3911
3912 /* Check if a threshold crossed before removing */
3913 __mem_cgroup_threshold(memcg, type == _MEMSWAP);
3914
3915 /* Calculate new number of threshold */
Kirill A. Shutemov2c488db2010-05-26 14:42:47 -07003916 size = 0;
3917 for (i = 0; i < thresholds->primary->size; i++) {
3918 if (thresholds->primary->entries[i].eventfd != eventfd)
Kirill A. Shutemov2e72b632010-03-10 15:22:24 -08003919 size++;
3920 }
3921
Kirill A. Shutemov2c488db2010-05-26 14:42:47 -07003922 new = thresholds->spare;
Kirill A. Shutemov907860e2010-05-26 14:42:46 -07003923
Kirill A. Shutemov2e72b632010-03-10 15:22:24 -08003924 /* Set thresholds array to NULL if we don't have thresholds */
3925 if (!size) {
Kirill A. Shutemov2c488db2010-05-26 14:42:47 -07003926 kfree(new);
3927 new = NULL;
Kirill A. Shutemov907860e2010-05-26 14:42:46 -07003928 goto swap_buffers;
Kirill A. Shutemov2e72b632010-03-10 15:22:24 -08003929 }
3930
Kirill A. Shutemov2c488db2010-05-26 14:42:47 -07003931 new->size = size;
Kirill A. Shutemov2e72b632010-03-10 15:22:24 -08003932
3933 /* Copy thresholds and find current threshold */
Kirill A. Shutemov2c488db2010-05-26 14:42:47 -07003934 new->current_threshold = -1;
3935 for (i = 0, j = 0; i < thresholds->primary->size; i++) {
3936 if (thresholds->primary->entries[i].eventfd == eventfd)
Kirill A. Shutemov2e72b632010-03-10 15:22:24 -08003937 continue;
3938
Kirill A. Shutemov2c488db2010-05-26 14:42:47 -07003939 new->entries[j] = thresholds->primary->entries[i];
3940 if (new->entries[j].threshold < usage) {
Kirill A. Shutemov2e72b632010-03-10 15:22:24 -08003941 /*
Kirill A. Shutemov2c488db2010-05-26 14:42:47 -07003942 * new->current_threshold will not be used
Kirill A. Shutemov2e72b632010-03-10 15:22:24 -08003943 * until rcu_assign_pointer(), so it's safe to increment
3944 * it here.
3945 */
Kirill A. Shutemov2c488db2010-05-26 14:42:47 -07003946 ++new->current_threshold;
Kirill A. Shutemov2e72b632010-03-10 15:22:24 -08003947 }
3948 j++;
3949 }
3950
Kirill A. Shutemov907860e2010-05-26 14:42:46 -07003951swap_buffers:
Kirill A. Shutemov2c488db2010-05-26 14:42:47 -07003952 /* Swap primary and spare array */
3953 thresholds->spare = thresholds->primary;
3954 rcu_assign_pointer(thresholds->primary, new);
Kirill A. Shutemov2e72b632010-03-10 15:22:24 -08003955
Kirill A. Shutemov907860e2010-05-26 14:42:46 -07003956 /* To be sure that nobody uses thresholds */
Kirill A. Shutemov2e72b632010-03-10 15:22:24 -08003957 synchronize_rcu();
3958
Kirill A. Shutemov2e72b632010-03-10 15:22:24 -08003959 mutex_unlock(&memcg->thresholds_lock);
Kirill A. Shutemov2e72b632010-03-10 15:22:24 -08003960}
KAMEZAWA Hiroyukic1e862c2009-01-07 18:07:55 -08003961
KAMEZAWA Hiroyuki9490ff22010-05-26 14:42:36 -07003962static int mem_cgroup_oom_register_event(struct cgroup *cgrp,
3963 struct cftype *cft, struct eventfd_ctx *eventfd, const char *args)
3964{
3965 struct mem_cgroup *memcg = mem_cgroup_from_cont(cgrp);
3966 struct mem_cgroup_eventfd_list *event;
3967 int type = MEMFILE_TYPE(cft->private);
3968
3969 BUG_ON(type != _OOM_TYPE);
3970 event = kmalloc(sizeof(*event), GFP_KERNEL);
3971 if (!event)
3972 return -ENOMEM;
3973
3974 mutex_lock(&memcg_oom_mutex);
3975
3976 event->eventfd = eventfd;
3977 list_add(&event->list, &memcg->oom_notify);
3978
3979 /* already in OOM ? */
3980 if (atomic_read(&memcg->oom_lock))
3981 eventfd_signal(eventfd, 1);
3982 mutex_unlock(&memcg_oom_mutex);
3983
3984 return 0;
3985}
3986
Kirill A. Shutemov907860e2010-05-26 14:42:46 -07003987static void mem_cgroup_oom_unregister_event(struct cgroup *cgrp,
KAMEZAWA Hiroyuki9490ff22010-05-26 14:42:36 -07003988 struct cftype *cft, struct eventfd_ctx *eventfd)
3989{
3990 struct mem_cgroup *mem = mem_cgroup_from_cont(cgrp);
3991 struct mem_cgroup_eventfd_list *ev, *tmp;
3992 int type = MEMFILE_TYPE(cft->private);
3993
3994 BUG_ON(type != _OOM_TYPE);
3995
3996 mutex_lock(&memcg_oom_mutex);
3997
3998 list_for_each_entry_safe(ev, tmp, &mem->oom_notify, list) {
3999 if (ev->eventfd == eventfd) {
4000 list_del(&ev->list);
4001 kfree(ev);
4002 }
4003 }
4004
4005 mutex_unlock(&memcg_oom_mutex);
KAMEZAWA Hiroyuki9490ff22010-05-26 14:42:36 -07004006}
4007
KAMEZAWA Hiroyuki3c11ecf2010-05-26 14:42:37 -07004008static int mem_cgroup_oom_control_read(struct cgroup *cgrp,
4009 struct cftype *cft, struct cgroup_map_cb *cb)
4010{
4011 struct mem_cgroup *mem = mem_cgroup_from_cont(cgrp);
4012
4013 cb->fill(cb, "oom_kill_disable", mem->oom_kill_disable);
4014
4015 if (atomic_read(&mem->oom_lock))
4016 cb->fill(cb, "under_oom", 1);
4017 else
4018 cb->fill(cb, "under_oom", 0);
4019 return 0;
4020}
4021
KAMEZAWA Hiroyuki3c11ecf2010-05-26 14:42:37 -07004022static int mem_cgroup_oom_control_write(struct cgroup *cgrp,
4023 struct cftype *cft, u64 val)
4024{
4025 struct mem_cgroup *mem = mem_cgroup_from_cont(cgrp);
4026 struct mem_cgroup *parent;
4027
4028 /* cannot set to root cgroup and only 0 and 1 are allowed */
4029 if (!cgrp->parent || !((val == 0) || (val == 1)))
4030 return -EINVAL;
4031
4032 parent = mem_cgroup_from_cont(cgrp->parent);
4033
4034 cgroup_lock();
4035 /* oom-kill-disable is a flag for subhierarchy. */
4036 if ((parent->use_hierarchy) ||
4037 (mem->use_hierarchy && !list_empty(&cgrp->children))) {
4038 cgroup_unlock();
4039 return -EINVAL;
4040 }
4041 mem->oom_kill_disable = val;
KAMEZAWA Hiroyuki4d845eb2010-06-29 15:05:18 -07004042 if (!val)
4043 memcg_oom_recover(mem);
KAMEZAWA Hiroyuki3c11ecf2010-05-26 14:42:37 -07004044 cgroup_unlock();
4045 return 0;
4046}
4047
Balbir Singh8cdea7c2008-02-07 00:13:50 -08004048static struct cftype mem_cgroup_files[] = {
4049 {
Balbir Singh0eea1032008-02-07 00:13:57 -08004050 .name = "usage_in_bytes",
KAMEZAWA Hiroyuki8c7c6e342009-01-07 18:08:00 -08004051 .private = MEMFILE_PRIVATE(_MEM, RES_USAGE),
Paul Menage2c3daa72008-04-29 00:59:58 -07004052 .read_u64 = mem_cgroup_read,
KAMEZAWA Hiroyuki9490ff22010-05-26 14:42:36 -07004053 .register_event = mem_cgroup_usage_register_event,
4054 .unregister_event = mem_cgroup_usage_unregister_event,
Balbir Singh8cdea7c2008-02-07 00:13:50 -08004055 },
4056 {
Pavel Emelyanovc84872e2008-04-29 01:00:17 -07004057 .name = "max_usage_in_bytes",
KAMEZAWA Hiroyuki8c7c6e342009-01-07 18:08:00 -08004058 .private = MEMFILE_PRIVATE(_MEM, RES_MAX_USAGE),
Pavel Emelyanov29f2a4d2008-04-29 01:00:21 -07004059 .trigger = mem_cgroup_reset,
Pavel Emelyanovc84872e2008-04-29 01:00:17 -07004060 .read_u64 = mem_cgroup_read,
4061 },
4062 {
Balbir Singh0eea1032008-02-07 00:13:57 -08004063 .name = "limit_in_bytes",
KAMEZAWA Hiroyuki8c7c6e342009-01-07 18:08:00 -08004064 .private = MEMFILE_PRIVATE(_MEM, RES_LIMIT),
Paul Menage856c13a2008-07-25 01:47:04 -07004065 .write_string = mem_cgroup_write,
Paul Menage2c3daa72008-04-29 00:59:58 -07004066 .read_u64 = mem_cgroup_read,
Balbir Singh8cdea7c2008-02-07 00:13:50 -08004067 },
4068 {
Balbir Singh296c81d2009-09-23 15:56:36 -07004069 .name = "soft_limit_in_bytes",
4070 .private = MEMFILE_PRIVATE(_MEM, RES_SOFT_LIMIT),
4071 .write_string = mem_cgroup_write,
4072 .read_u64 = mem_cgroup_read,
4073 },
4074 {
Balbir Singh8cdea7c2008-02-07 00:13:50 -08004075 .name = "failcnt",
KAMEZAWA Hiroyuki8c7c6e342009-01-07 18:08:00 -08004076 .private = MEMFILE_PRIVATE(_MEM, RES_FAILCNT),
Pavel Emelyanov29f2a4d2008-04-29 01:00:21 -07004077 .trigger = mem_cgroup_reset,
Paul Menage2c3daa72008-04-29 00:59:58 -07004078 .read_u64 = mem_cgroup_read,
Balbir Singh8cdea7c2008-02-07 00:13:50 -08004079 },
Balbir Singh8697d332008-02-07 00:13:59 -08004080 {
KAMEZAWA Hiroyukid2ceb9b2008-02-07 00:14:25 -08004081 .name = "stat",
Paul Menagec64745c2008-04-29 01:00:02 -07004082 .read_map = mem_control_stat_show,
KAMEZAWA Hiroyukid2ceb9b2008-02-07 00:14:25 -08004083 },
KAMEZAWA Hiroyukic1e862c2009-01-07 18:07:55 -08004084 {
4085 .name = "force_empty",
4086 .trigger = mem_cgroup_force_empty_write,
4087 },
Balbir Singh18f59ea2009-01-07 18:08:07 -08004088 {
4089 .name = "use_hierarchy",
4090 .write_u64 = mem_cgroup_hierarchy_write,
4091 .read_u64 = mem_cgroup_hierarchy_read,
4092 },
KOSAKI Motohiroa7885eb2009-01-07 18:08:24 -08004093 {
4094 .name = "swappiness",
4095 .read_u64 = mem_cgroup_swappiness_read,
4096 .write_u64 = mem_cgroup_swappiness_write,
4097 },
Daisuke Nishimura7dc74be2010-03-10 15:22:13 -08004098 {
4099 .name = "move_charge_at_immigrate",
4100 .read_u64 = mem_cgroup_move_charge_read,
4101 .write_u64 = mem_cgroup_move_charge_write,
4102 },
KAMEZAWA Hiroyuki9490ff22010-05-26 14:42:36 -07004103 {
4104 .name = "oom_control",
KAMEZAWA Hiroyuki3c11ecf2010-05-26 14:42:37 -07004105 .read_map = mem_cgroup_oom_control_read,
4106 .write_u64 = mem_cgroup_oom_control_write,
KAMEZAWA Hiroyuki9490ff22010-05-26 14:42:36 -07004107 .register_event = mem_cgroup_oom_register_event,
4108 .unregister_event = mem_cgroup_oom_unregister_event,
4109 .private = MEMFILE_PRIVATE(_OOM_TYPE, OOM_CONTROL),
4110 },
Balbir Singh8cdea7c2008-02-07 00:13:50 -08004111};
4112
KAMEZAWA Hiroyuki8c7c6e342009-01-07 18:08:00 -08004113#ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP
4114static struct cftype memsw_cgroup_files[] = {
4115 {
4116 .name = "memsw.usage_in_bytes",
4117 .private = MEMFILE_PRIVATE(_MEMSWAP, RES_USAGE),
4118 .read_u64 = mem_cgroup_read,
KAMEZAWA Hiroyuki9490ff22010-05-26 14:42:36 -07004119 .register_event = mem_cgroup_usage_register_event,
4120 .unregister_event = mem_cgroup_usage_unregister_event,
KAMEZAWA Hiroyuki8c7c6e342009-01-07 18:08:00 -08004121 },
4122 {
4123 .name = "memsw.max_usage_in_bytes",
4124 .private = MEMFILE_PRIVATE(_MEMSWAP, RES_MAX_USAGE),
4125 .trigger = mem_cgroup_reset,
4126 .read_u64 = mem_cgroup_read,
4127 },
4128 {
4129 .name = "memsw.limit_in_bytes",
4130 .private = MEMFILE_PRIVATE(_MEMSWAP, RES_LIMIT),
4131 .write_string = mem_cgroup_write,
4132 .read_u64 = mem_cgroup_read,
4133 },
4134 {
4135 .name = "memsw.failcnt",
4136 .private = MEMFILE_PRIVATE(_MEMSWAP, RES_FAILCNT),
4137 .trigger = mem_cgroup_reset,
4138 .read_u64 = mem_cgroup_read,
4139 },
4140};
4141
4142static int register_memsw_files(struct cgroup *cont, struct cgroup_subsys *ss)
4143{
4144 if (!do_swap_account)
4145 return 0;
4146 return cgroup_add_files(cont, ss, memsw_cgroup_files,
4147 ARRAY_SIZE(memsw_cgroup_files));
4148};
4149#else
4150static int register_memsw_files(struct cgroup *cont, struct cgroup_subsys *ss)
4151{
4152 return 0;
4153}
4154#endif
4155
KAMEZAWA Hiroyuki6d12e2d2008-02-07 00:14:31 -08004156static int alloc_mem_cgroup_per_zone_info(struct mem_cgroup *mem, int node)
4157{
4158 struct mem_cgroup_per_node *pn;
KAMEZAWA Hiroyuki1ecaab22008-02-07 00:14:38 -08004159 struct mem_cgroup_per_zone *mz;
Christoph Lameterb69408e2008-10-18 20:26:14 -07004160 enum lru_list l;
KAMEZAWA Hiroyuki41e33552008-04-08 17:41:54 -07004161 int zone, tmp = node;
KAMEZAWA Hiroyuki1ecaab22008-02-07 00:14:38 -08004162 /*
4163 * This routine is called against possible nodes.
4164 * But it's BUG to call kmalloc() against offline node.
4165 *
4166 * TODO: this routine can waste much memory for nodes which will
4167 * never be onlined. It's better to use memory hotplug callback
4168 * function.
4169 */
KAMEZAWA Hiroyuki41e33552008-04-08 17:41:54 -07004170 if (!node_state(node, N_NORMAL_MEMORY))
4171 tmp = -1;
4172 pn = kmalloc_node(sizeof(*pn), GFP_KERNEL, tmp);
KAMEZAWA Hiroyuki6d12e2d2008-02-07 00:14:31 -08004173 if (!pn)
4174 return 1;
KAMEZAWA Hiroyuki1ecaab22008-02-07 00:14:38 -08004175
KAMEZAWA Hiroyuki6d12e2d2008-02-07 00:14:31 -08004176 mem->info.nodeinfo[node] = pn;
4177 memset(pn, 0, sizeof(*pn));
KAMEZAWA Hiroyuki1ecaab22008-02-07 00:14:38 -08004178
4179 for (zone = 0; zone < MAX_NR_ZONES; zone++) {
4180 mz = &pn->zoneinfo[zone];
Christoph Lameterb69408e2008-10-18 20:26:14 -07004181 for_each_lru(l)
4182 INIT_LIST_HEAD(&mz->lists[l]);
Balbir Singhf64c3f52009-09-23 15:56:37 -07004183 mz->usage_in_excess = 0;
Balbir Singh4e416952009-09-23 15:56:39 -07004184 mz->on_tree = false;
4185 mz->mem = mem;
KAMEZAWA Hiroyuki1ecaab22008-02-07 00:14:38 -08004186 }
KAMEZAWA Hiroyuki6d12e2d2008-02-07 00:14:31 -08004187 return 0;
4188}
4189
KAMEZAWA Hiroyuki1ecaab22008-02-07 00:14:38 -08004190static void free_mem_cgroup_per_zone_info(struct mem_cgroup *mem, int node)
4191{
4192 kfree(mem->info.nodeinfo[node]);
4193}
4194
KAMEZAWA Hiroyuki33327942008-04-29 01:00:24 -07004195static struct mem_cgroup *mem_cgroup_alloc(void)
4196{
4197 struct mem_cgroup *mem;
KAMEZAWA Hiroyukic62b1a32010-03-10 15:22:29 -08004198 int size = sizeof(struct mem_cgroup);
KAMEZAWA Hiroyuki33327942008-04-29 01:00:24 -07004199
KAMEZAWA Hiroyukic62b1a32010-03-10 15:22:29 -08004200 /* Can be very big if MAX_NUMNODES is very big */
Jan Blunckc8dad2b2009-01-07 18:07:53 -08004201 if (size < PAGE_SIZE)
4202 mem = kmalloc(size, GFP_KERNEL);
KAMEZAWA Hiroyuki33327942008-04-29 01:00:24 -07004203 else
Jan Blunckc8dad2b2009-01-07 18:07:53 -08004204 mem = vmalloc(size);
KAMEZAWA Hiroyuki33327942008-04-29 01:00:24 -07004205
Dan Carpentere7bbcdf2010-03-23 13:35:12 -07004206 if (!mem)
4207 return NULL;
4208
4209 memset(mem, 0, size);
KAMEZAWA Hiroyukic62b1a32010-03-10 15:22:29 -08004210 mem->stat = alloc_percpu(struct mem_cgroup_stat_cpu);
Dan Carpenterd2e61b82010-11-11 14:05:12 -08004211 if (!mem->stat)
4212 goto out_free;
KAMEZAWA Hiroyuki711d3d22010-10-27 15:33:42 -07004213 spin_lock_init(&mem->pcp_counter_lock);
KAMEZAWA Hiroyuki33327942008-04-29 01:00:24 -07004214 return mem;
Dan Carpenterd2e61b82010-11-11 14:05:12 -08004215
4216out_free:
4217 if (size < PAGE_SIZE)
4218 kfree(mem);
4219 else
4220 vfree(mem);
4221 return NULL;
KAMEZAWA Hiroyuki33327942008-04-29 01:00:24 -07004222}
4223
KAMEZAWA Hiroyuki8c7c6e342009-01-07 18:08:00 -08004224/*
4225 * At destroying mem_cgroup, references from swap_cgroup can remain.
4226 * (scanning all at force_empty is too costly...)
4227 *
4228 * Instead of clearing all references at force_empty, we remember
4229 * the number of reference from swap_cgroup and free mem_cgroup when
4230 * it goes down to 0.
4231 *
KAMEZAWA Hiroyuki8c7c6e342009-01-07 18:08:00 -08004232 * Removal of cgroup itself succeeds regardless of refs from swap.
4233 */
4234
KAMEZAWA Hiroyukia7ba0ee2009-01-07 18:08:32 -08004235static void __mem_cgroup_free(struct mem_cgroup *mem)
KAMEZAWA Hiroyuki33327942008-04-29 01:00:24 -07004236{
KAMEZAWA Hiroyuki08e552c2009-01-07 18:08:01 -08004237 int node;
4238
Balbir Singhf64c3f52009-09-23 15:56:37 -07004239 mem_cgroup_remove_from_trees(mem);
KAMEZAWA Hiroyuki04046e12009-04-02 16:57:33 -07004240 free_css_id(&mem_cgroup_subsys, &mem->css);
4241
KAMEZAWA Hiroyuki08e552c2009-01-07 18:08:01 -08004242 for_each_node_state(node, N_POSSIBLE)
4243 free_mem_cgroup_per_zone_info(mem, node);
4244
KAMEZAWA Hiroyukic62b1a32010-03-10 15:22:29 -08004245 free_percpu(mem->stat);
4246 if (sizeof(struct mem_cgroup) < PAGE_SIZE)
KAMEZAWA Hiroyuki33327942008-04-29 01:00:24 -07004247 kfree(mem);
4248 else
4249 vfree(mem);
4250}
4251
KAMEZAWA Hiroyuki8c7c6e342009-01-07 18:08:00 -08004252static void mem_cgroup_get(struct mem_cgroup *mem)
4253{
4254 atomic_inc(&mem->refcnt);
4255}
4256
Daisuke Nishimura483c30b2010-03-10 15:22:18 -08004257static void __mem_cgroup_put(struct mem_cgroup *mem, int count)
KAMEZAWA Hiroyuki8c7c6e342009-01-07 18:08:00 -08004258{
Daisuke Nishimura483c30b2010-03-10 15:22:18 -08004259 if (atomic_sub_and_test(count, &mem->refcnt)) {
Daisuke Nishimura7bcc1bb2009-01-29 14:25:11 -08004260 struct mem_cgroup *parent = parent_mem_cgroup(mem);
KAMEZAWA Hiroyukia7ba0ee2009-01-07 18:08:32 -08004261 __mem_cgroup_free(mem);
Daisuke Nishimura7bcc1bb2009-01-29 14:25:11 -08004262 if (parent)
4263 mem_cgroup_put(parent);
4264 }
KAMEZAWA Hiroyuki8c7c6e342009-01-07 18:08:00 -08004265}
4266
Daisuke Nishimura483c30b2010-03-10 15:22:18 -08004267static void mem_cgroup_put(struct mem_cgroup *mem)
4268{
4269 __mem_cgroup_put(mem, 1);
4270}
4271
Daisuke Nishimura7bcc1bb2009-01-29 14:25:11 -08004272/*
4273 * Returns the parent mem_cgroup in memcgroup hierarchy with hierarchy enabled.
4274 */
4275static struct mem_cgroup *parent_mem_cgroup(struct mem_cgroup *mem)
4276{
4277 if (!mem->res.parent)
4278 return NULL;
4279 return mem_cgroup_from_res_counter(mem->res.parent, res);
4280}
KAMEZAWA Hiroyuki33327942008-04-29 01:00:24 -07004281
KAMEZAWA Hiroyukic0777192009-01-07 18:07:57 -08004282#ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP
4283static void __init enable_swap_cgroup(void)
4284{
Hirokazu Takahashif8d665422009-01-07 18:08:02 -08004285 if (!mem_cgroup_disabled() && really_do_swap_account)
KAMEZAWA Hiroyukic0777192009-01-07 18:07:57 -08004286 do_swap_account = 1;
4287}
4288#else
4289static void __init enable_swap_cgroup(void)
4290{
4291}
4292#endif
4293
Balbir Singhf64c3f52009-09-23 15:56:37 -07004294static int mem_cgroup_soft_limit_tree_init(void)
4295{
4296 struct mem_cgroup_tree_per_node *rtpn;
4297 struct mem_cgroup_tree_per_zone *rtpz;
4298 int tmp, node, zone;
4299
4300 for_each_node_state(node, N_POSSIBLE) {
4301 tmp = node;
4302 if (!node_state(node, N_NORMAL_MEMORY))
4303 tmp = -1;
4304 rtpn = kzalloc_node(sizeof(*rtpn), GFP_KERNEL, tmp);
4305 if (!rtpn)
4306 return 1;
4307
4308 soft_limit_tree.rb_tree_per_node[node] = rtpn;
4309
4310 for (zone = 0; zone < MAX_NR_ZONES; zone++) {
4311 rtpz = &rtpn->rb_tree_per_zone[zone];
4312 rtpz->rb_root = RB_ROOT;
4313 spin_lock_init(&rtpz->lock);
4314 }
4315 }
4316 return 0;
4317}
4318
Li Zefan0eb253e2009-01-15 13:51:25 -08004319static struct cgroup_subsys_state * __ref
Balbir Singh8cdea7c2008-02-07 00:13:50 -08004320mem_cgroup_create(struct cgroup_subsys *ss, struct cgroup *cont)
4321{
Balbir Singh28dbc4b2009-01-07 18:08:05 -08004322 struct mem_cgroup *mem, *parent;
KAMEZAWA Hiroyuki04046e12009-04-02 16:57:33 -07004323 long error = -ENOMEM;
KAMEZAWA Hiroyuki6d12e2d2008-02-07 00:14:31 -08004324 int node;
Balbir Singh8cdea7c2008-02-07 00:13:50 -08004325
Jan Blunckc8dad2b2009-01-07 18:07:53 -08004326 mem = mem_cgroup_alloc();
4327 if (!mem)
KAMEZAWA Hiroyuki04046e12009-04-02 16:57:33 -07004328 return ERR_PTR(error);
Pavel Emelianov78fb7462008-02-07 00:13:51 -08004329
KAMEZAWA Hiroyuki6d12e2d2008-02-07 00:14:31 -08004330 for_each_node_state(node, N_POSSIBLE)
4331 if (alloc_mem_cgroup_per_zone_info(mem, node))
4332 goto free_out;
Balbir Singhf64c3f52009-09-23 15:56:37 -07004333
KAMEZAWA Hiroyukic0777192009-01-07 18:07:57 -08004334 /* root ? */
Balbir Singh28dbc4b2009-01-07 18:08:05 -08004335 if (cont->parent == NULL) {
KAMEZAWA Hiroyukicdec2e42009-12-15 16:47:08 -08004336 int cpu;
KAMEZAWA Hiroyukic0777192009-01-07 18:07:57 -08004337 enable_swap_cgroup();
Balbir Singh28dbc4b2009-01-07 18:08:05 -08004338 parent = NULL;
Balbir Singh4b3bde42009-09-23 15:56:32 -07004339 root_mem_cgroup = mem;
Balbir Singhf64c3f52009-09-23 15:56:37 -07004340 if (mem_cgroup_soft_limit_tree_init())
4341 goto free_out;
KAMEZAWA Hiroyukicdec2e42009-12-15 16:47:08 -08004342 for_each_possible_cpu(cpu) {
4343 struct memcg_stock_pcp *stock =
4344 &per_cpu(memcg_stock, cpu);
4345 INIT_WORK(&stock->work, drain_local_stock);
4346 }
KAMEZAWA Hiroyuki711d3d22010-10-27 15:33:42 -07004347 hotcpu_notifier(memcg_cpu_hotplug_callback, 0);
Balbir Singh18f59ea2009-01-07 18:08:07 -08004348 } else {
Balbir Singh28dbc4b2009-01-07 18:08:05 -08004349 parent = mem_cgroup_from_cont(cont->parent);
Balbir Singh18f59ea2009-01-07 18:08:07 -08004350 mem->use_hierarchy = parent->use_hierarchy;
KAMEZAWA Hiroyuki3c11ecf2010-05-26 14:42:37 -07004351 mem->oom_kill_disable = parent->oom_kill_disable;
Balbir Singh18f59ea2009-01-07 18:08:07 -08004352 }
Balbir Singh28dbc4b2009-01-07 18:08:05 -08004353
Balbir Singh18f59ea2009-01-07 18:08:07 -08004354 if (parent && parent->use_hierarchy) {
4355 res_counter_init(&mem->res, &parent->res);
4356 res_counter_init(&mem->memsw, &parent->memsw);
Daisuke Nishimura7bcc1bb2009-01-29 14:25:11 -08004357 /*
4358 * We increment refcnt of the parent to ensure that we can
4359 * safely access it on res_counter_charge/uncharge.
4360 * This refcnt will be decremented when freeing this
4361 * mem_cgroup(see mem_cgroup_put).
4362 */
4363 mem_cgroup_get(parent);
Balbir Singh18f59ea2009-01-07 18:08:07 -08004364 } else {
4365 res_counter_init(&mem->res, NULL);
4366 res_counter_init(&mem->memsw, NULL);
4367 }
KAMEZAWA Hiroyuki04046e12009-04-02 16:57:33 -07004368 mem->last_scanned_child = 0;
KOSAKI Motohiro2733c062009-01-07 18:08:23 -08004369 spin_lock_init(&mem->reclaim_param_lock);
KAMEZAWA Hiroyuki9490ff22010-05-26 14:42:36 -07004370 INIT_LIST_HEAD(&mem->oom_notify);
Balbir Singh6d61ef42009-01-07 18:08:06 -08004371
KOSAKI Motohiroa7885eb2009-01-07 18:08:24 -08004372 if (parent)
4373 mem->swappiness = get_swappiness(parent);
KAMEZAWA Hiroyukia7ba0ee2009-01-07 18:08:32 -08004374 atomic_set(&mem->refcnt, 1);
Daisuke Nishimura7dc74be2010-03-10 15:22:13 -08004375 mem->move_charge_at_immigrate = 0;
Kirill A. Shutemov2e72b632010-03-10 15:22:24 -08004376 mutex_init(&mem->thresholds_lock);
Balbir Singh8cdea7c2008-02-07 00:13:50 -08004377 return &mem->css;
KAMEZAWA Hiroyuki6d12e2d2008-02-07 00:14:31 -08004378free_out:
KAMEZAWA Hiroyukia7ba0ee2009-01-07 18:08:32 -08004379 __mem_cgroup_free(mem);
Balbir Singh4b3bde42009-09-23 15:56:32 -07004380 root_mem_cgroup = NULL;
KAMEZAWA Hiroyuki04046e12009-04-02 16:57:33 -07004381 return ERR_PTR(error);
Balbir Singh8cdea7c2008-02-07 00:13:50 -08004382}
4383
KAMEZAWA Hiroyukiec64f512009-04-02 16:57:26 -07004384static int mem_cgroup_pre_destroy(struct cgroup_subsys *ss,
KAMEZAWA Hiroyukidf878fb2008-02-07 00:14:28 -08004385 struct cgroup *cont)
4386{
4387 struct mem_cgroup *mem = mem_cgroup_from_cont(cont);
KAMEZAWA Hiroyukiec64f512009-04-02 16:57:26 -07004388
4389 return mem_cgroup_force_empty(mem, false);
KAMEZAWA Hiroyukidf878fb2008-02-07 00:14:28 -08004390}
4391
Balbir Singh8cdea7c2008-02-07 00:13:50 -08004392static void mem_cgroup_destroy(struct cgroup_subsys *ss,
4393 struct cgroup *cont)
4394{
Daisuke Nishimurac268e992009-01-15 13:51:13 -08004395 struct mem_cgroup *mem = mem_cgroup_from_cont(cont);
Daisuke Nishimurac268e992009-01-15 13:51:13 -08004396
Daisuke Nishimurac268e992009-01-15 13:51:13 -08004397 mem_cgroup_put(mem);
Balbir Singh8cdea7c2008-02-07 00:13:50 -08004398}
4399
4400static int mem_cgroup_populate(struct cgroup_subsys *ss,
4401 struct cgroup *cont)
4402{
KAMEZAWA Hiroyuki8c7c6e342009-01-07 18:08:00 -08004403 int ret;
4404
4405 ret = cgroup_add_files(cont, ss, mem_cgroup_files,
4406 ARRAY_SIZE(mem_cgroup_files));
4407
4408 if (!ret)
4409 ret = register_memsw_files(cont, ss);
4410 return ret;
Balbir Singh8cdea7c2008-02-07 00:13:50 -08004411}
4412
Daisuke Nishimura02491442010-03-10 15:22:17 -08004413#ifdef CONFIG_MMU
Daisuke Nishimura7dc74be2010-03-10 15:22:13 -08004414/* Handlers for move charge at task migration. */
Daisuke Nishimura854ffa82010-03-10 15:22:15 -08004415#define PRECHARGE_COUNT_AT_ONCE 256
4416static int mem_cgroup_do_precharge(unsigned long count)
Daisuke Nishimura7dc74be2010-03-10 15:22:13 -08004417{
Daisuke Nishimura854ffa82010-03-10 15:22:15 -08004418 int ret = 0;
4419 int batch_count = PRECHARGE_COUNT_AT_ONCE;
Daisuke Nishimura4ffef5f2010-03-10 15:22:14 -08004420 struct mem_cgroup *mem = mc.to;
4421
Daisuke Nishimura854ffa82010-03-10 15:22:15 -08004422 if (mem_cgroup_is_root(mem)) {
4423 mc.precharge += count;
4424 /* we don't need css_get for root */
4425 return ret;
4426 }
4427 /* try to charge at once */
4428 if (count > 1) {
4429 struct res_counter *dummy;
4430 /*
4431 * "mem" cannot be under rmdir() because we've already checked
4432 * by cgroup_lock_live_cgroup() that it is not removed and we
4433 * are still under the same cgroup_mutex. So we can postpone
4434 * css_get().
4435 */
4436 if (res_counter_charge(&mem->res, PAGE_SIZE * count, &dummy))
4437 goto one_by_one;
4438 if (do_swap_account && res_counter_charge(&mem->memsw,
4439 PAGE_SIZE * count, &dummy)) {
4440 res_counter_uncharge(&mem->res, PAGE_SIZE * count);
4441 goto one_by_one;
4442 }
4443 mc.precharge += count;
Daisuke Nishimura854ffa82010-03-10 15:22:15 -08004444 return ret;
4445 }
4446one_by_one:
4447 /* fall back to one by one charge */
4448 while (count--) {
4449 if (signal_pending(current)) {
4450 ret = -EINTR;
4451 break;
4452 }
4453 if (!batch_count--) {
4454 batch_count = PRECHARGE_COUNT_AT_ONCE;
4455 cond_resched();
4456 }
KAMEZAWA Hiroyuki430e48632010-03-10 15:22:30 -08004457 ret = __mem_cgroup_try_charge(NULL, GFP_KERNEL, &mem, false);
Daisuke Nishimura854ffa82010-03-10 15:22:15 -08004458 if (ret || !mem)
4459 /* mem_cgroup_clear_mc() will do uncharge later */
4460 return -ENOMEM;
4461 mc.precharge++;
4462 }
Daisuke Nishimura4ffef5f2010-03-10 15:22:14 -08004463 return ret;
4464}
4465
4466/**
4467 * is_target_pte_for_mc - check a pte whether it is valid for move charge
4468 * @vma: the vma the pte to be checked belongs
4469 * @addr: the address corresponding to the pte to be checked
4470 * @ptent: the pte to be checked
Daisuke Nishimura02491442010-03-10 15:22:17 -08004471 * @target: the pointer the target page or swap ent will be stored(can be NULL)
Daisuke Nishimura4ffef5f2010-03-10 15:22:14 -08004472 *
4473 * Returns
4474 * 0(MC_TARGET_NONE): if the pte is not a target for move charge.
4475 * 1(MC_TARGET_PAGE): if the page corresponding to this pte is a target for
4476 * move charge. if @target is not NULL, the page is stored in target->page
4477 * with extra refcnt got(Callers should handle it).
Daisuke Nishimura02491442010-03-10 15:22:17 -08004478 * 2(MC_TARGET_SWAP): if the swap entry corresponding to this pte is a
4479 * target for charge migration. if @target is not NULL, the entry is stored
4480 * in target->ent.
Daisuke Nishimura4ffef5f2010-03-10 15:22:14 -08004481 *
4482 * Called with pte lock held.
4483 */
Daisuke Nishimura4ffef5f2010-03-10 15:22:14 -08004484union mc_target {
4485 struct page *page;
Daisuke Nishimura02491442010-03-10 15:22:17 -08004486 swp_entry_t ent;
Daisuke Nishimura4ffef5f2010-03-10 15:22:14 -08004487};
4488
Daisuke Nishimura4ffef5f2010-03-10 15:22:14 -08004489enum mc_target_type {
4490 MC_TARGET_NONE, /* not used */
4491 MC_TARGET_PAGE,
Daisuke Nishimura02491442010-03-10 15:22:17 -08004492 MC_TARGET_SWAP,
Daisuke Nishimura4ffef5f2010-03-10 15:22:14 -08004493};
4494
Daisuke Nishimura90254a62010-05-26 14:42:38 -07004495static struct page *mc_handle_present_pte(struct vm_area_struct *vma,
4496 unsigned long addr, pte_t ptent)
4497{
4498 struct page *page = vm_normal_page(vma, addr, ptent);
4499
4500 if (!page || !page_mapped(page))
4501 return NULL;
4502 if (PageAnon(page)) {
4503 /* we don't move shared anon */
4504 if (!move_anon() || page_mapcount(page) > 2)
4505 return NULL;
Daisuke Nishimura87946a72010-05-26 14:42:39 -07004506 } else if (!move_file())
4507 /* we ignore mapcount for file pages */
Daisuke Nishimura90254a62010-05-26 14:42:38 -07004508 return NULL;
4509 if (!get_page_unless_zero(page))
4510 return NULL;
4511
4512 return page;
4513}
4514
4515static struct page *mc_handle_swap_pte(struct vm_area_struct *vma,
4516 unsigned long addr, pte_t ptent, swp_entry_t *entry)
4517{
4518 int usage_count;
4519 struct page *page = NULL;
4520 swp_entry_t ent = pte_to_swp_entry(ptent);
4521
4522 if (!move_anon() || non_swap_entry(ent))
4523 return NULL;
4524 usage_count = mem_cgroup_count_swap_user(ent, &page);
4525 if (usage_count > 1) { /* we don't move shared anon */
4526 if (page)
4527 put_page(page);
4528 return NULL;
4529 }
4530 if (do_swap_account)
4531 entry->val = ent.val;
4532
4533 return page;
4534}
4535
Daisuke Nishimura87946a72010-05-26 14:42:39 -07004536static struct page *mc_handle_file_pte(struct vm_area_struct *vma,
4537 unsigned long addr, pte_t ptent, swp_entry_t *entry)
4538{
4539 struct page *page = NULL;
4540 struct inode *inode;
4541 struct address_space *mapping;
4542 pgoff_t pgoff;
4543
4544 if (!vma->vm_file) /* anonymous vma */
4545 return NULL;
4546 if (!move_file())
4547 return NULL;
4548
4549 inode = vma->vm_file->f_path.dentry->d_inode;
4550 mapping = vma->vm_file->f_mapping;
4551 if (pte_none(ptent))
4552 pgoff = linear_page_index(vma, addr);
4553 else /* pte_file(ptent) is true */
4554 pgoff = pte_to_pgoff(ptent);
4555
4556 /* page is moved even if it's not RSS of this task(page-faulted). */
4557 if (!mapping_cap_swap_backed(mapping)) { /* normal file */
4558 page = find_get_page(mapping, pgoff);
4559 } else { /* shmem/tmpfs file. we should take account of swap too. */
4560 swp_entry_t ent;
4561 mem_cgroup_get_shmem_target(inode, pgoff, &page, &ent);
4562 if (do_swap_account)
4563 entry->val = ent.val;
4564 }
4565
4566 return page;
4567}
4568
Daisuke Nishimura4ffef5f2010-03-10 15:22:14 -08004569static int is_target_pte_for_mc(struct vm_area_struct *vma,
4570 unsigned long addr, pte_t ptent, union mc_target *target)
4571{
Daisuke Nishimura02491442010-03-10 15:22:17 -08004572 struct page *page = NULL;
Daisuke Nishimura4ffef5f2010-03-10 15:22:14 -08004573 struct page_cgroup *pc;
4574 int ret = 0;
Daisuke Nishimura02491442010-03-10 15:22:17 -08004575 swp_entry_t ent = { .val = 0 };
Daisuke Nishimura4ffef5f2010-03-10 15:22:14 -08004576
Daisuke Nishimura90254a62010-05-26 14:42:38 -07004577 if (pte_present(ptent))
4578 page = mc_handle_present_pte(vma, addr, ptent);
4579 else if (is_swap_pte(ptent))
4580 page = mc_handle_swap_pte(vma, addr, ptent, &ent);
Daisuke Nishimura87946a72010-05-26 14:42:39 -07004581 else if (pte_none(ptent) || pte_file(ptent))
4582 page = mc_handle_file_pte(vma, addr, ptent, &ent);
Daisuke Nishimura90254a62010-05-26 14:42:38 -07004583
4584 if (!page && !ent.val)
Daisuke Nishimura02491442010-03-10 15:22:17 -08004585 return 0;
Daisuke Nishimura02491442010-03-10 15:22:17 -08004586 if (page) {
4587 pc = lookup_page_cgroup(page);
4588 /*
4589 * Do only loose check w/o page_cgroup lock.
4590 * mem_cgroup_move_account() checks the pc is valid or not under
4591 * the lock.
4592 */
4593 if (PageCgroupUsed(pc) && pc->mem_cgroup == mc.from) {
4594 ret = MC_TARGET_PAGE;
4595 if (target)
4596 target->page = page;
4597 }
4598 if (!ret || !target)
4599 put_page(page);
4600 }
Daisuke Nishimura90254a62010-05-26 14:42:38 -07004601 /* There is a swap entry and a page doesn't exist or isn't charged */
4602 if (ent.val && !ret &&
KAMEZAWA Hiroyuki7f0f1542010-05-11 14:06:58 -07004603 css_id(&mc.from->css) == lookup_swap_cgroup(ent)) {
4604 ret = MC_TARGET_SWAP;
4605 if (target)
4606 target->ent = ent;
Daisuke Nishimura02491442010-03-10 15:22:17 -08004607 }
Daisuke Nishimura4ffef5f2010-03-10 15:22:14 -08004608 return ret;
4609}
4610
4611static int mem_cgroup_count_precharge_pte_range(pmd_t *pmd,
4612 unsigned long addr, unsigned long end,
4613 struct mm_walk *walk)
4614{
4615 struct vm_area_struct *vma = walk->private;
4616 pte_t *pte;
4617 spinlock_t *ptl;
4618
4619 pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl);
4620 for (; addr != end; pte++, addr += PAGE_SIZE)
4621 if (is_target_pte_for_mc(vma, addr, *pte, NULL))
4622 mc.precharge++; /* increment precharge temporarily */
4623 pte_unmap_unlock(pte - 1, ptl);
4624 cond_resched();
4625
Daisuke Nishimura7dc74be2010-03-10 15:22:13 -08004626 return 0;
4627}
4628
Daisuke Nishimura4ffef5f2010-03-10 15:22:14 -08004629static unsigned long mem_cgroup_count_precharge(struct mm_struct *mm)
4630{
4631 unsigned long precharge;
4632 struct vm_area_struct *vma;
4633
4634 down_read(&mm->mmap_sem);
4635 for (vma = mm->mmap; vma; vma = vma->vm_next) {
4636 struct mm_walk mem_cgroup_count_precharge_walk = {
4637 .pmd_entry = mem_cgroup_count_precharge_pte_range,
4638 .mm = mm,
4639 .private = vma,
4640 };
4641 if (is_vm_hugetlb_page(vma))
4642 continue;
Daisuke Nishimura4ffef5f2010-03-10 15:22:14 -08004643 walk_page_range(vma->vm_start, vma->vm_end,
4644 &mem_cgroup_count_precharge_walk);
4645 }
4646 up_read(&mm->mmap_sem);
4647
4648 precharge = mc.precharge;
4649 mc.precharge = 0;
4650
4651 return precharge;
4652}
4653
Daisuke Nishimura4ffef5f2010-03-10 15:22:14 -08004654static int mem_cgroup_precharge_mc(struct mm_struct *mm)
4655{
Daisuke Nishimura854ffa82010-03-10 15:22:15 -08004656 return mem_cgroup_do_precharge(mem_cgroup_count_precharge(mm));
Daisuke Nishimura4ffef5f2010-03-10 15:22:14 -08004657}
4658
4659static void mem_cgroup_clear_mc(void)
4660{
KAMEZAWA Hiroyuki2bd9bb22010-08-10 18:02:58 -07004661 struct mem_cgroup *from = mc.from;
4662 struct mem_cgroup *to = mc.to;
4663
Daisuke Nishimura4ffef5f2010-03-10 15:22:14 -08004664 /* we must uncharge all the leftover precharges from mc.to */
Daisuke Nishimura854ffa82010-03-10 15:22:15 -08004665 if (mc.precharge) {
4666 __mem_cgroup_cancel_charge(mc.to, mc.precharge);
4667 mc.precharge = 0;
4668 }
4669 /*
4670 * we didn't uncharge from mc.from at mem_cgroup_move_account(), so
4671 * we must uncharge here.
4672 */
4673 if (mc.moved_charge) {
4674 __mem_cgroup_cancel_charge(mc.from, mc.moved_charge);
4675 mc.moved_charge = 0;
Daisuke Nishimura4ffef5f2010-03-10 15:22:14 -08004676 }
Daisuke Nishimura483c30b2010-03-10 15:22:18 -08004677 /* we must fixup refcnts and charges */
4678 if (mc.moved_swap) {
Daisuke Nishimura483c30b2010-03-10 15:22:18 -08004679 /* uncharge swap account from the old cgroup */
4680 if (!mem_cgroup_is_root(mc.from))
4681 res_counter_uncharge(&mc.from->memsw,
4682 PAGE_SIZE * mc.moved_swap);
4683 __mem_cgroup_put(mc.from, mc.moved_swap);
4684
4685 if (!mem_cgroup_is_root(mc.to)) {
4686 /*
4687 * we charged both to->res and to->memsw, so we should
4688 * uncharge to->res.
4689 */
4690 res_counter_uncharge(&mc.to->res,
4691 PAGE_SIZE * mc.moved_swap);
Daisuke Nishimura483c30b2010-03-10 15:22:18 -08004692 }
4693 /* we've already done mem_cgroup_get(mc.to) */
4694
4695 mc.moved_swap = 0;
4696 }
KAMEZAWA Hiroyuki2bd9bb22010-08-10 18:02:58 -07004697 spin_lock(&mc.lock);
Daisuke Nishimura4ffef5f2010-03-10 15:22:14 -08004698 mc.from = NULL;
4699 mc.to = NULL;
Daisuke Nishimura8033b972010-03-10 15:22:16 -08004700 mc.moving_task = NULL;
KAMEZAWA Hiroyuki2bd9bb22010-08-10 18:02:58 -07004701 spin_unlock(&mc.lock);
KAMEZAWA Hiroyuki32047e22010-10-27 15:33:40 -07004702 mem_cgroup_end_move(from);
KAMEZAWA Hiroyuki2bd9bb22010-08-10 18:02:58 -07004703 memcg_oom_recover(from);
4704 memcg_oom_recover(to);
Daisuke Nishimura8033b972010-03-10 15:22:16 -08004705 wake_up_all(&mc.waitq);
Daisuke Nishimura4ffef5f2010-03-10 15:22:14 -08004706}
4707
Daisuke Nishimura7dc74be2010-03-10 15:22:13 -08004708static int mem_cgroup_can_attach(struct cgroup_subsys *ss,
4709 struct cgroup *cgroup,
4710 struct task_struct *p,
4711 bool threadgroup)
4712{
4713 int ret = 0;
4714 struct mem_cgroup *mem = mem_cgroup_from_cont(cgroup);
4715
4716 if (mem->move_charge_at_immigrate) {
4717 struct mm_struct *mm;
4718 struct mem_cgroup *from = mem_cgroup_from_task(p);
4719
4720 VM_BUG_ON(from == mem);
4721
4722 mm = get_task_mm(p);
4723 if (!mm)
4724 return 0;
Daisuke Nishimura7dc74be2010-03-10 15:22:13 -08004725 /* We move charges only when we move a owner of the mm */
Daisuke Nishimura4ffef5f2010-03-10 15:22:14 -08004726 if (mm->owner == p) {
4727 VM_BUG_ON(mc.from);
4728 VM_BUG_ON(mc.to);
4729 VM_BUG_ON(mc.precharge);
Daisuke Nishimura854ffa82010-03-10 15:22:15 -08004730 VM_BUG_ON(mc.moved_charge);
Daisuke Nishimura483c30b2010-03-10 15:22:18 -08004731 VM_BUG_ON(mc.moved_swap);
Daisuke Nishimura8033b972010-03-10 15:22:16 -08004732 VM_BUG_ON(mc.moving_task);
KAMEZAWA Hiroyuki32047e22010-10-27 15:33:40 -07004733 mem_cgroup_start_move(from);
KAMEZAWA Hiroyuki2bd9bb22010-08-10 18:02:58 -07004734 spin_lock(&mc.lock);
Daisuke Nishimura4ffef5f2010-03-10 15:22:14 -08004735 mc.from = from;
4736 mc.to = mem;
4737 mc.precharge = 0;
Daisuke Nishimura854ffa82010-03-10 15:22:15 -08004738 mc.moved_charge = 0;
Daisuke Nishimura483c30b2010-03-10 15:22:18 -08004739 mc.moved_swap = 0;
Daisuke Nishimura8033b972010-03-10 15:22:16 -08004740 mc.moving_task = current;
KAMEZAWA Hiroyuki2bd9bb22010-08-10 18:02:58 -07004741 spin_unlock(&mc.lock);
Daisuke Nishimura7dc74be2010-03-10 15:22:13 -08004742
Daisuke Nishimura4ffef5f2010-03-10 15:22:14 -08004743 ret = mem_cgroup_precharge_mc(mm);
4744 if (ret)
4745 mem_cgroup_clear_mc();
4746 }
Daisuke Nishimura7dc74be2010-03-10 15:22:13 -08004747 mmput(mm);
4748 }
4749 return ret;
4750}
4751
4752static void mem_cgroup_cancel_attach(struct cgroup_subsys *ss,
4753 struct cgroup *cgroup,
4754 struct task_struct *p,
4755 bool threadgroup)
4756{
Daisuke Nishimura4ffef5f2010-03-10 15:22:14 -08004757 mem_cgroup_clear_mc();
Daisuke Nishimura7dc74be2010-03-10 15:22:13 -08004758}
4759
Daisuke Nishimura4ffef5f2010-03-10 15:22:14 -08004760static int mem_cgroup_move_charge_pte_range(pmd_t *pmd,
4761 unsigned long addr, unsigned long end,
4762 struct mm_walk *walk)
Daisuke Nishimura7dc74be2010-03-10 15:22:13 -08004763{
Daisuke Nishimura4ffef5f2010-03-10 15:22:14 -08004764 int ret = 0;
4765 struct vm_area_struct *vma = walk->private;
4766 pte_t *pte;
4767 spinlock_t *ptl;
4768
4769retry:
4770 pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl);
4771 for (; addr != end; addr += PAGE_SIZE) {
4772 pte_t ptent = *(pte++);
4773 union mc_target target;
4774 int type;
4775 struct page *page;
4776 struct page_cgroup *pc;
Daisuke Nishimura02491442010-03-10 15:22:17 -08004777 swp_entry_t ent;
Daisuke Nishimura4ffef5f2010-03-10 15:22:14 -08004778
4779 if (!mc.precharge)
4780 break;
4781
4782 type = is_target_pte_for_mc(vma, addr, ptent, &target);
4783 switch (type) {
4784 case MC_TARGET_PAGE:
4785 page = target.page;
4786 if (isolate_lru_page(page))
4787 goto put;
4788 pc = lookup_page_cgroup(page);
Daisuke Nishimura854ffa82010-03-10 15:22:15 -08004789 if (!mem_cgroup_move_account(pc,
4790 mc.from, mc.to, false)) {
Daisuke Nishimura4ffef5f2010-03-10 15:22:14 -08004791 mc.precharge--;
Daisuke Nishimura854ffa82010-03-10 15:22:15 -08004792 /* we uncharge from mc.from later. */
4793 mc.moved_charge++;
Daisuke Nishimura4ffef5f2010-03-10 15:22:14 -08004794 }
4795 putback_lru_page(page);
4796put: /* is_target_pte_for_mc() gets the page */
4797 put_page(page);
4798 break;
Daisuke Nishimura02491442010-03-10 15:22:17 -08004799 case MC_TARGET_SWAP:
4800 ent = target.ent;
Daisuke Nishimura483c30b2010-03-10 15:22:18 -08004801 if (!mem_cgroup_move_swap_account(ent,
4802 mc.from, mc.to, false)) {
Daisuke Nishimura02491442010-03-10 15:22:17 -08004803 mc.precharge--;
Daisuke Nishimura483c30b2010-03-10 15:22:18 -08004804 /* we fixup refcnts and charges later. */
4805 mc.moved_swap++;
4806 }
Daisuke Nishimura02491442010-03-10 15:22:17 -08004807 break;
Daisuke Nishimura4ffef5f2010-03-10 15:22:14 -08004808 default:
4809 break;
4810 }
4811 }
4812 pte_unmap_unlock(pte - 1, ptl);
4813 cond_resched();
4814
4815 if (addr != end) {
4816 /*
4817 * We have consumed all precharges we got in can_attach().
4818 * We try charge one by one, but don't do any additional
4819 * charges to mc.to if we have failed in charge once in attach()
4820 * phase.
4821 */
Daisuke Nishimura854ffa82010-03-10 15:22:15 -08004822 ret = mem_cgroup_do_precharge(1);
Daisuke Nishimura4ffef5f2010-03-10 15:22:14 -08004823 if (!ret)
4824 goto retry;
4825 }
4826
4827 return ret;
4828}
4829
4830static void mem_cgroup_move_charge(struct mm_struct *mm)
4831{
4832 struct vm_area_struct *vma;
4833
4834 lru_add_drain_all();
4835 down_read(&mm->mmap_sem);
4836 for (vma = mm->mmap; vma; vma = vma->vm_next) {
4837 int ret;
4838 struct mm_walk mem_cgroup_move_charge_walk = {
4839 .pmd_entry = mem_cgroup_move_charge_pte_range,
4840 .mm = mm,
4841 .private = vma,
4842 };
4843 if (is_vm_hugetlb_page(vma))
4844 continue;
Daisuke Nishimura4ffef5f2010-03-10 15:22:14 -08004845 ret = walk_page_range(vma->vm_start, vma->vm_end,
4846 &mem_cgroup_move_charge_walk);
4847 if (ret)
4848 /*
4849 * means we have consumed all precharges and failed in
4850 * doing additional charge. Just abandon here.
4851 */
4852 break;
4853 }
4854 up_read(&mm->mmap_sem);
Daisuke Nishimura7dc74be2010-03-10 15:22:13 -08004855}
4856
Balbir Singh67e465a2008-02-07 00:13:54 -08004857static void mem_cgroup_move_task(struct cgroup_subsys *ss,
4858 struct cgroup *cont,
4859 struct cgroup *old_cont,
Ben Blumbe367d02009-09-23 15:56:31 -07004860 struct task_struct *p,
4861 bool threadgroup)
Balbir Singh67e465a2008-02-07 00:13:54 -08004862{
Daisuke Nishimura4ffef5f2010-03-10 15:22:14 -08004863 struct mm_struct *mm;
4864
4865 if (!mc.to)
4866 /* no need to move charge */
4867 return;
4868
4869 mm = get_task_mm(p);
4870 if (mm) {
4871 mem_cgroup_move_charge(mm);
4872 mmput(mm);
4873 }
4874 mem_cgroup_clear_mc();
Balbir Singh67e465a2008-02-07 00:13:54 -08004875}
Daisuke Nishimura5cfb80a2010-03-23 13:35:11 -07004876#else /* !CONFIG_MMU */
4877static int mem_cgroup_can_attach(struct cgroup_subsys *ss,
4878 struct cgroup *cgroup,
4879 struct task_struct *p,
4880 bool threadgroup)
4881{
4882 return 0;
4883}
4884static void mem_cgroup_cancel_attach(struct cgroup_subsys *ss,
4885 struct cgroup *cgroup,
4886 struct task_struct *p,
4887 bool threadgroup)
4888{
4889}
4890static void mem_cgroup_move_task(struct cgroup_subsys *ss,
4891 struct cgroup *cont,
4892 struct cgroup *old_cont,
4893 struct task_struct *p,
4894 bool threadgroup)
4895{
4896}
4897#endif
Balbir Singh67e465a2008-02-07 00:13:54 -08004898
Balbir Singh8cdea7c2008-02-07 00:13:50 -08004899struct cgroup_subsys mem_cgroup_subsys = {
4900 .name = "memory",
4901 .subsys_id = mem_cgroup_subsys_id,
4902 .create = mem_cgroup_create,
KAMEZAWA Hiroyukidf878fb2008-02-07 00:14:28 -08004903 .pre_destroy = mem_cgroup_pre_destroy,
Balbir Singh8cdea7c2008-02-07 00:13:50 -08004904 .destroy = mem_cgroup_destroy,
4905 .populate = mem_cgroup_populate,
Daisuke Nishimura7dc74be2010-03-10 15:22:13 -08004906 .can_attach = mem_cgroup_can_attach,
4907 .cancel_attach = mem_cgroup_cancel_attach,
Balbir Singh67e465a2008-02-07 00:13:54 -08004908 .attach = mem_cgroup_move_task,
KAMEZAWA Hiroyuki6d12e2d2008-02-07 00:14:31 -08004909 .early_init = 0,
KAMEZAWA Hiroyuki04046e12009-04-02 16:57:33 -07004910 .use_id = 1,
Balbir Singh8cdea7c2008-02-07 00:13:50 -08004911};
KAMEZAWA Hiroyukic0777192009-01-07 18:07:57 -08004912
4913#ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP
4914
4915static int __init disable_swap_account(char *s)
4916{
4917 really_do_swap_account = 0;
4918 return 1;
4919}
4920__setup("noswapaccount", disable_swap_account);
4921#endif