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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;
Michal Hockoa42c3902010-11-24 12:57:08 -080064
65/* for remember boot option*/
66#ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP_ENABLED
67static int really_do_swap_account __initdata = 1;
68#else
69static int really_do_swap_account __initdata = 0;
70#endif
71
KAMEZAWA Hiroyukic0777192009-01-07 18:07:57 -080072#else
73#define do_swap_account (0)
74#endif
75
76
Balbir Singh8cdea7c2008-02-07 00:13:50 -080077/*
KAMEZAWA Hiroyukid52aa412008-02-07 00:14:24 -080078 * Statistics for memory cgroup.
79 */
80enum mem_cgroup_stat_index {
81 /*
82 * For MEM_CONTAINER_TYPE_ALL, usage = pagecache + rss.
83 */
84 MEM_CGROUP_STAT_CACHE, /* # of pages charged as cache */
Balbir Singhd69b0422009-06-17 16:26:34 -070085 MEM_CGROUP_STAT_RSS, /* # of pages charged as anon rss */
KAMEZAWA Hiroyukid8046582009-12-15 16:47:09 -080086 MEM_CGROUP_STAT_FILE_MAPPED, /* # of pages charged as file rss */
Balbir Singh0c3e73e2009-09-23 15:56:42 -070087 MEM_CGROUP_STAT_SWAPOUT, /* # of pages, swapped out */
KAMEZAWA Hiroyuki711d3d22010-10-27 15:33:42 -070088 MEM_CGROUP_STAT_DATA, /* end of data requires synchronization */
KAMEZAWA Hiroyuki32047e22010-10-27 15:33:40 -070089 MEM_CGROUP_ON_MOVE, /* someone is moving account between groups */
KAMEZAWA Hiroyukid52aa412008-02-07 00:14:24 -080090 MEM_CGROUP_STAT_NSTATS,
91};
92
Johannes Weinere9f89742011-03-23 16:42:37 -070093enum mem_cgroup_events_index {
94 MEM_CGROUP_EVENTS_PGPGIN, /* # of pages paged in */
95 MEM_CGROUP_EVENTS_PGPGOUT, /* # of pages paged out */
96 MEM_CGROUP_EVENTS_COUNT, /* # of pages paged in/out */
97 MEM_CGROUP_EVENTS_NSTATS,
98};
Johannes Weiner7a159cc2011-03-23 16:42:38 -070099/*
100 * Per memcg event counter is incremented at every pagein/pageout. With THP,
101 * it will be incremated by the number of pages. This counter is used for
102 * for trigger some periodic events. This is straightforward and better
103 * than using jiffies etc. to handle periodic memcg event.
104 */
105enum mem_cgroup_events_target {
106 MEM_CGROUP_TARGET_THRESH,
107 MEM_CGROUP_TARGET_SOFTLIMIT,
108 MEM_CGROUP_NTARGETS,
109};
110#define THRESHOLDS_EVENTS_TARGET (128)
111#define SOFTLIMIT_EVENTS_TARGET (1024)
Johannes Weinere9f89742011-03-23 16:42:37 -0700112
KAMEZAWA Hiroyukid52aa412008-02-07 00:14:24 -0800113struct mem_cgroup_stat_cpu {
Johannes Weiner7a159cc2011-03-23 16:42:38 -0700114 long count[MEM_CGROUP_STAT_NSTATS];
Johannes Weinere9f89742011-03-23 16:42:37 -0700115 unsigned long events[MEM_CGROUP_EVENTS_NSTATS];
Johannes Weiner7a159cc2011-03-23 16:42:38 -0700116 unsigned long targets[MEM_CGROUP_NTARGETS];
KAMEZAWA Hiroyukid52aa412008-02-07 00:14:24 -0800117};
118
KAMEZAWA Hiroyukid52aa412008-02-07 00:14:24 -0800119/*
KAMEZAWA Hiroyuki6d12e2d2008-02-07 00:14:31 -0800120 * per-zone information in memory controller.
121 */
KAMEZAWA Hiroyuki6d12e2d2008-02-07 00:14:31 -0800122struct mem_cgroup_per_zone {
KAMEZAWA Hiroyuki072c56c12008-02-07 00:14:39 -0800123 /*
124 * spin_lock to protect the per cgroup LRU
125 */
Christoph Lameterb69408e2008-10-18 20:26:14 -0700126 struct list_head lists[NR_LRU_LISTS];
127 unsigned long count[NR_LRU_LISTS];
KOSAKI Motohiro3e2f41f2009-01-07 18:08:20 -0800128
129 struct zone_reclaim_stat reclaim_stat;
Balbir Singhf64c3f52009-09-23 15:56:37 -0700130 struct rb_node tree_node; /* RB tree node */
131 unsigned long long usage_in_excess;/* Set to the value by which */
132 /* the soft limit is exceeded*/
133 bool on_tree;
Balbir Singh4e416952009-09-23 15:56:39 -0700134 struct mem_cgroup *mem; /* Back pointer, we cannot */
135 /* use container_of */
KAMEZAWA Hiroyuki6d12e2d2008-02-07 00:14:31 -0800136};
137/* Macro for accessing counter */
138#define MEM_CGROUP_ZSTAT(mz, idx) ((mz)->count[(idx)])
139
140struct mem_cgroup_per_node {
141 struct mem_cgroup_per_zone zoneinfo[MAX_NR_ZONES];
142};
143
144struct mem_cgroup_lru_info {
145 struct mem_cgroup_per_node *nodeinfo[MAX_NUMNODES];
146};
147
148/*
Balbir Singhf64c3f52009-09-23 15:56:37 -0700149 * Cgroups above their limits are maintained in a RB-Tree, independent of
150 * their hierarchy representation
151 */
152
153struct mem_cgroup_tree_per_zone {
154 struct rb_root rb_root;
155 spinlock_t lock;
156};
157
158struct mem_cgroup_tree_per_node {
159 struct mem_cgroup_tree_per_zone rb_tree_per_zone[MAX_NR_ZONES];
160};
161
162struct mem_cgroup_tree {
163 struct mem_cgroup_tree_per_node *rb_tree_per_node[MAX_NUMNODES];
164};
165
166static struct mem_cgroup_tree soft_limit_tree __read_mostly;
167
Kirill A. Shutemov2e72b632010-03-10 15:22:24 -0800168struct mem_cgroup_threshold {
169 struct eventfd_ctx *eventfd;
170 u64 threshold;
171};
172
KAMEZAWA Hiroyuki9490ff22010-05-26 14:42:36 -0700173/* For threshold */
Kirill A. Shutemov2e72b632010-03-10 15:22:24 -0800174struct mem_cgroup_threshold_ary {
175 /* An array index points to threshold just below usage. */
Phil Carmody5407a562010-05-26 14:42:42 -0700176 int current_threshold;
Kirill A. Shutemov2e72b632010-03-10 15:22:24 -0800177 /* Size of entries[] */
178 unsigned int size;
179 /* Array of thresholds */
180 struct mem_cgroup_threshold entries[0];
181};
Kirill A. Shutemov2c488db2010-05-26 14:42:47 -0700182
183struct mem_cgroup_thresholds {
184 /* Primary thresholds array */
185 struct mem_cgroup_threshold_ary *primary;
186 /*
187 * Spare threshold array.
188 * This is needed to make mem_cgroup_unregister_event() "never fail".
189 * It must be able to store at least primary->size - 1 entries.
190 */
191 struct mem_cgroup_threshold_ary *spare;
192};
193
KAMEZAWA Hiroyuki9490ff22010-05-26 14:42:36 -0700194/* for OOM */
195struct mem_cgroup_eventfd_list {
196 struct list_head list;
197 struct eventfd_ctx *eventfd;
198};
Kirill A. Shutemov2e72b632010-03-10 15:22:24 -0800199
Kirill A. Shutemov2e72b632010-03-10 15:22:24 -0800200static void mem_cgroup_threshold(struct mem_cgroup *mem);
KAMEZAWA Hiroyuki9490ff22010-05-26 14:42:36 -0700201static void mem_cgroup_oom_notify(struct mem_cgroup *mem);
Kirill A. Shutemov2e72b632010-03-10 15:22:24 -0800202
Balbir Singhf64c3f52009-09-23 15:56:37 -0700203/*
Balbir Singh8cdea7c2008-02-07 00:13:50 -0800204 * The memory controller data structure. The memory controller controls both
205 * page cache and RSS per cgroup. We would eventually like to provide
206 * statistics based on the statistics developed by Rik Van Riel for clock-pro,
207 * to help the administrator determine what knobs to tune.
208 *
209 * TODO: Add a water mark for the memory controller. Reclaim will begin when
Balbir Singh8a9f3cc2008-02-07 00:13:53 -0800210 * we hit the water mark. May be even add a low water mark, such that
211 * no reclaim occurs from a cgroup at it's low water mark, this is
212 * a feature that will be implemented much later in the future.
Balbir Singh8cdea7c2008-02-07 00:13:50 -0800213 */
214struct mem_cgroup {
215 struct cgroup_subsys_state css;
216 /*
217 * the counter to account for memory usage
218 */
219 struct res_counter res;
Pavel Emelianov78fb7462008-02-07 00:13:51 -0800220 /*
KAMEZAWA Hiroyuki8c7c6e342009-01-07 18:08:00 -0800221 * the counter to account for mem+swap usage.
222 */
223 struct res_counter memsw;
224 /*
Pavel Emelianov78fb7462008-02-07 00:13:51 -0800225 * Per cgroup active and inactive list, similar to the
226 * per zone LRU lists.
Pavel Emelianov78fb7462008-02-07 00:13:51 -0800227 */
KAMEZAWA Hiroyuki6d12e2d2008-02-07 00:14:31 -0800228 struct mem_cgroup_lru_info info;
Balbir Singh6d61ef42009-01-07 18:08:06 -0800229 /*
André Goddard Rosaaf901ca2009-11-14 13:09:05 -0200230 * While reclaiming in a hierarchy, we cache the last child we
KAMEZAWA Hiroyuki04046e12009-04-02 16:57:33 -0700231 * reclaimed from.
Balbir Singh6d61ef42009-01-07 18:08:06 -0800232 */
KAMEZAWA Hiroyuki04046e12009-04-02 16:57:33 -0700233 int last_scanned_child;
Balbir Singh18f59ea2009-01-07 18:08:07 -0800234 /*
235 * Should the accounting and control be hierarchical, per subtree?
236 */
237 bool use_hierarchy;
KAMEZAWA Hiroyuki867578c2010-03-10 15:22:39 -0800238 atomic_t oom_lock;
KAMEZAWA Hiroyuki8c7c6e342009-01-07 18:08:00 -0800239 atomic_t refcnt;
KOSAKI Motohiro14797e22009-01-07 18:08:18 -0800240
KOSAKI Motohiroa7885eb2009-01-07 18:08:24 -0800241 unsigned int swappiness;
KAMEZAWA Hiroyuki3c11ecf2010-05-26 14:42:37 -0700242 /* OOM-Killer disable */
243 int oom_kill_disable;
KOSAKI Motohiroa7885eb2009-01-07 18:08:24 -0800244
KAMEZAWA Hiroyuki22a668d2009-06-17 16:27:19 -0700245 /* set when res.limit == memsw.limit */
246 bool memsw_is_minimum;
247
Kirill A. Shutemov2e72b632010-03-10 15:22:24 -0800248 /* protect arrays of thresholds */
249 struct mutex thresholds_lock;
250
251 /* thresholds for memory usage. RCU-protected */
Kirill A. Shutemov2c488db2010-05-26 14:42:47 -0700252 struct mem_cgroup_thresholds thresholds;
Kirill A. Shutemov907860e2010-05-26 14:42:46 -0700253
Kirill A. Shutemov2e72b632010-03-10 15:22:24 -0800254 /* thresholds for mem+swap usage. RCU-protected */
Kirill A. Shutemov2c488db2010-05-26 14:42:47 -0700255 struct mem_cgroup_thresholds memsw_thresholds;
Kirill A. Shutemov907860e2010-05-26 14:42:46 -0700256
KAMEZAWA Hiroyuki9490ff22010-05-26 14:42:36 -0700257 /* For oom notifier event fd */
258 struct list_head oom_notify;
259
KAMEZAWA Hiroyukid52aa412008-02-07 00:14:24 -0800260 /*
Daisuke Nishimura7dc74be2010-03-10 15:22:13 -0800261 * Should we move charges of a task when a task is moved into this
262 * mem_cgroup ? And what type of charges should we move ?
263 */
264 unsigned long move_charge_at_immigrate;
Daisuke Nishimura7dc74be2010-03-10 15:22:13 -0800265 /*
KAMEZAWA Hiroyukic62b1a32010-03-10 15:22:29 -0800266 * percpu counter.
KAMEZAWA Hiroyukid52aa412008-02-07 00:14:24 -0800267 */
KAMEZAWA Hiroyukic62b1a32010-03-10 15:22:29 -0800268 struct mem_cgroup_stat_cpu *stat;
KAMEZAWA Hiroyuki711d3d22010-10-27 15:33:42 -0700269 /*
270 * used when a cpu is offlined or other synchronizations
271 * See mem_cgroup_read_stat().
272 */
273 struct mem_cgroup_stat_cpu nocpu_base;
274 spinlock_t pcp_counter_lock;
Balbir Singh8cdea7c2008-02-07 00:13:50 -0800275};
276
Daisuke Nishimura7dc74be2010-03-10 15:22:13 -0800277/* Stuffs for move charges at task migration. */
278/*
279 * Types of charges to be moved. "move_charge_at_immitgrate" is treated as a
280 * left-shifted bitmap of these types.
281 */
282enum move_type {
Daisuke Nishimura4ffef5f2010-03-10 15:22:14 -0800283 MOVE_CHARGE_TYPE_ANON, /* private anonymous page and swap of it */
Daisuke Nishimura87946a72010-05-26 14:42:39 -0700284 MOVE_CHARGE_TYPE_FILE, /* file page(including tmpfs) and swap of it */
Daisuke Nishimura7dc74be2010-03-10 15:22:13 -0800285 NR_MOVE_TYPE,
286};
287
Daisuke Nishimura4ffef5f2010-03-10 15:22:14 -0800288/* "mc" and its members are protected by cgroup_mutex */
289static struct move_charge_struct {
Daisuke Nishimurab1dd6932010-11-24 12:57:06 -0800290 spinlock_t lock; /* for from, to */
Daisuke Nishimura4ffef5f2010-03-10 15:22:14 -0800291 struct mem_cgroup *from;
292 struct mem_cgroup *to;
293 unsigned long precharge;
Daisuke Nishimura854ffa82010-03-10 15:22:15 -0800294 unsigned long moved_charge;
Daisuke Nishimura483c30b2010-03-10 15:22:18 -0800295 unsigned long moved_swap;
Daisuke Nishimura8033b972010-03-10 15:22:16 -0800296 struct task_struct *moving_task; /* a task moving charges */
297 wait_queue_head_t waitq; /* a waitq for other context */
298} mc = {
KAMEZAWA Hiroyuki2bd9bb22010-08-10 18:02:58 -0700299 .lock = __SPIN_LOCK_UNLOCKED(mc.lock),
Daisuke Nishimura8033b972010-03-10 15:22:16 -0800300 .waitq = __WAIT_QUEUE_HEAD_INITIALIZER(mc.waitq),
301};
Daisuke Nishimura4ffef5f2010-03-10 15:22:14 -0800302
Daisuke Nishimura90254a62010-05-26 14:42:38 -0700303static bool move_anon(void)
304{
305 return test_bit(MOVE_CHARGE_TYPE_ANON,
306 &mc.to->move_charge_at_immigrate);
307}
308
Daisuke Nishimura87946a72010-05-26 14:42:39 -0700309static bool move_file(void)
310{
311 return test_bit(MOVE_CHARGE_TYPE_FILE,
312 &mc.to->move_charge_at_immigrate);
313}
314
Balbir Singh4e416952009-09-23 15:56:39 -0700315/*
316 * Maximum loops in mem_cgroup_hierarchical_reclaim(), used for soft
317 * limit reclaim to prevent infinite loops, if they ever occur.
318 */
319#define MEM_CGROUP_MAX_RECLAIM_LOOPS (100)
320#define MEM_CGROUP_MAX_SOFT_LIMIT_RECLAIM_LOOPS (2)
321
KAMEZAWA Hiroyuki217bc312008-02-07 00:14:17 -0800322enum charge_type {
323 MEM_CGROUP_CHARGE_TYPE_CACHE = 0,
324 MEM_CGROUP_CHARGE_TYPE_MAPPED,
Rik van Riel4f98a2f2008-10-18 20:26:32 -0700325 MEM_CGROUP_CHARGE_TYPE_SHMEM, /* used by page migration of shmem */
KAMEZAWA Hiroyukic05555b2008-10-18 20:28:11 -0700326 MEM_CGROUP_CHARGE_TYPE_FORCE, /* used by force_empty */
KAMEZAWA Hiroyukid13d1442009-01-07 18:07:56 -0800327 MEM_CGROUP_CHARGE_TYPE_SWAPOUT, /* for accounting swapcache */
KAMEZAWA Hiroyuki8a9478c2009-06-17 16:27:17 -0700328 MEM_CGROUP_CHARGE_TYPE_DROP, /* a page was unused swap cache */
KAMEZAWA Hiroyukic05555b2008-10-18 20:28:11 -0700329 NR_CHARGE_TYPE,
330};
331
KAMEZAWA Hiroyuki8c7c6e342009-01-07 18:08:00 -0800332/* for encoding cft->private value on file */
333#define _MEM (0)
334#define _MEMSWAP (1)
KAMEZAWA Hiroyuki9490ff22010-05-26 14:42:36 -0700335#define _OOM_TYPE (2)
KAMEZAWA Hiroyuki8c7c6e342009-01-07 18:08:00 -0800336#define MEMFILE_PRIVATE(x, val) (((x) << 16) | (val))
337#define MEMFILE_TYPE(val) (((val) >> 16) & 0xffff)
338#define MEMFILE_ATTR(val) ((val) & 0xffff)
KAMEZAWA Hiroyuki9490ff22010-05-26 14:42:36 -0700339/* Used for OOM nofiier */
340#define OOM_CONTROL (0)
KAMEZAWA Hiroyuki8c7c6e342009-01-07 18:08:00 -0800341
Balbir Singh75822b42009-09-23 15:56:38 -0700342/*
343 * Reclaim flags for mem_cgroup_hierarchical_reclaim
344 */
345#define MEM_CGROUP_RECLAIM_NOSWAP_BIT 0x0
346#define MEM_CGROUP_RECLAIM_NOSWAP (1 << MEM_CGROUP_RECLAIM_NOSWAP_BIT)
347#define MEM_CGROUP_RECLAIM_SHRINK_BIT 0x1
348#define MEM_CGROUP_RECLAIM_SHRINK (1 << MEM_CGROUP_RECLAIM_SHRINK_BIT)
Balbir Singh4e416952009-09-23 15:56:39 -0700349#define MEM_CGROUP_RECLAIM_SOFT_BIT 0x2
350#define MEM_CGROUP_RECLAIM_SOFT (1 << MEM_CGROUP_RECLAIM_SOFT_BIT)
Balbir Singh75822b42009-09-23 15:56:38 -0700351
KAMEZAWA Hiroyuki8c7c6e342009-01-07 18:08:00 -0800352static void mem_cgroup_get(struct mem_cgroup *mem);
353static void mem_cgroup_put(struct mem_cgroup *mem);
Daisuke Nishimura7bcc1bb2009-01-29 14:25:11 -0800354static struct mem_cgroup *parent_mem_cgroup(struct mem_cgroup *mem);
KAMEZAWA Hiroyukicdec2e42009-12-15 16:47:08 -0800355static void drain_all_stock_async(void);
KAMEZAWA Hiroyuki8c7c6e342009-01-07 18:08:00 -0800356
Balbir Singhf64c3f52009-09-23 15:56:37 -0700357static struct mem_cgroup_per_zone *
358mem_cgroup_zoneinfo(struct mem_cgroup *mem, int nid, int zid)
359{
360 return &mem->info.nodeinfo[nid]->zoneinfo[zid];
361}
362
Wu Fengguangd3242362009-12-16 12:19:59 +0100363struct cgroup_subsys_state *mem_cgroup_css(struct mem_cgroup *mem)
364{
365 return &mem->css;
366}
367
Balbir Singhf64c3f52009-09-23 15:56:37 -0700368static struct mem_cgroup_per_zone *
Johannes Weiner97a6c372011-03-23 16:42:27 -0700369page_cgroup_zoneinfo(struct mem_cgroup *mem, struct page *page)
Balbir Singhf64c3f52009-09-23 15:56:37 -0700370{
Johannes Weiner97a6c372011-03-23 16:42:27 -0700371 int nid = page_to_nid(page);
372 int zid = page_zonenum(page);
Balbir Singhf64c3f52009-09-23 15:56:37 -0700373
Balbir Singhf64c3f52009-09-23 15:56:37 -0700374 return mem_cgroup_zoneinfo(mem, nid, zid);
375}
376
377static struct mem_cgroup_tree_per_zone *
378soft_limit_tree_node_zone(int nid, int zid)
379{
380 return &soft_limit_tree.rb_tree_per_node[nid]->rb_tree_per_zone[zid];
381}
382
383static struct mem_cgroup_tree_per_zone *
384soft_limit_tree_from_page(struct page *page)
385{
386 int nid = page_to_nid(page);
387 int zid = page_zonenum(page);
388
389 return &soft_limit_tree.rb_tree_per_node[nid]->rb_tree_per_zone[zid];
390}
391
392static void
Balbir Singh4e416952009-09-23 15:56:39 -0700393__mem_cgroup_insert_exceeded(struct mem_cgroup *mem,
Balbir Singhf64c3f52009-09-23 15:56:37 -0700394 struct mem_cgroup_per_zone *mz,
KAMEZAWA Hiroyukief8745c2009-10-01 15:44:12 -0700395 struct mem_cgroup_tree_per_zone *mctz,
396 unsigned long long new_usage_in_excess)
Balbir Singhf64c3f52009-09-23 15:56:37 -0700397{
398 struct rb_node **p = &mctz->rb_root.rb_node;
399 struct rb_node *parent = NULL;
400 struct mem_cgroup_per_zone *mz_node;
401
402 if (mz->on_tree)
403 return;
404
KAMEZAWA Hiroyukief8745c2009-10-01 15:44:12 -0700405 mz->usage_in_excess = new_usage_in_excess;
406 if (!mz->usage_in_excess)
407 return;
Balbir Singhf64c3f52009-09-23 15:56:37 -0700408 while (*p) {
409 parent = *p;
410 mz_node = rb_entry(parent, struct mem_cgroup_per_zone,
411 tree_node);
412 if (mz->usage_in_excess < mz_node->usage_in_excess)
413 p = &(*p)->rb_left;
414 /*
415 * We can't avoid mem cgroups that are over their soft
416 * limit by the same amount
417 */
418 else if (mz->usage_in_excess >= mz_node->usage_in_excess)
419 p = &(*p)->rb_right;
420 }
421 rb_link_node(&mz->tree_node, parent, p);
422 rb_insert_color(&mz->tree_node, &mctz->rb_root);
423 mz->on_tree = true;
Balbir Singh4e416952009-09-23 15:56:39 -0700424}
425
426static void
427__mem_cgroup_remove_exceeded(struct mem_cgroup *mem,
428 struct mem_cgroup_per_zone *mz,
429 struct mem_cgroup_tree_per_zone *mctz)
430{
431 if (!mz->on_tree)
432 return;
433 rb_erase(&mz->tree_node, &mctz->rb_root);
434 mz->on_tree = false;
435}
436
437static void
Balbir Singhf64c3f52009-09-23 15:56:37 -0700438mem_cgroup_remove_exceeded(struct mem_cgroup *mem,
439 struct mem_cgroup_per_zone *mz,
440 struct mem_cgroup_tree_per_zone *mctz)
441{
442 spin_lock(&mctz->lock);
Balbir Singh4e416952009-09-23 15:56:39 -0700443 __mem_cgroup_remove_exceeded(mem, mz, mctz);
Balbir Singhf64c3f52009-09-23 15:56:37 -0700444 spin_unlock(&mctz->lock);
445}
446
Balbir Singhf64c3f52009-09-23 15:56:37 -0700447
448static void mem_cgroup_update_tree(struct mem_cgroup *mem, struct page *page)
449{
KAMEZAWA Hiroyukief8745c2009-10-01 15:44:12 -0700450 unsigned long long excess;
Balbir Singhf64c3f52009-09-23 15:56:37 -0700451 struct mem_cgroup_per_zone *mz;
452 struct mem_cgroup_tree_per_zone *mctz;
KAMEZAWA Hiroyuki4e649152009-10-01 15:44:11 -0700453 int nid = page_to_nid(page);
454 int zid = page_zonenum(page);
Balbir Singhf64c3f52009-09-23 15:56:37 -0700455 mctz = soft_limit_tree_from_page(page);
456
457 /*
KAMEZAWA Hiroyuki4e649152009-10-01 15:44:11 -0700458 * Necessary to update all ancestors when hierarchy is used.
459 * because their event counter is not touched.
Balbir Singhf64c3f52009-09-23 15:56:37 -0700460 */
KAMEZAWA Hiroyuki4e649152009-10-01 15:44:11 -0700461 for (; mem; mem = parent_mem_cgroup(mem)) {
462 mz = mem_cgroup_zoneinfo(mem, nid, zid);
KAMEZAWA Hiroyukief8745c2009-10-01 15:44:12 -0700463 excess = res_counter_soft_limit_excess(&mem->res);
KAMEZAWA Hiroyuki4e649152009-10-01 15:44:11 -0700464 /*
465 * We have to update the tree if mz is on RB-tree or
466 * mem is over its softlimit.
467 */
KAMEZAWA Hiroyukief8745c2009-10-01 15:44:12 -0700468 if (excess || mz->on_tree) {
KAMEZAWA Hiroyuki4e649152009-10-01 15:44:11 -0700469 spin_lock(&mctz->lock);
470 /* if on-tree, remove it */
471 if (mz->on_tree)
472 __mem_cgroup_remove_exceeded(mem, mz, mctz);
473 /*
KAMEZAWA Hiroyukief8745c2009-10-01 15:44:12 -0700474 * Insert again. mz->usage_in_excess will be updated.
475 * If excess is 0, no tree ops.
KAMEZAWA Hiroyuki4e649152009-10-01 15:44:11 -0700476 */
KAMEZAWA Hiroyukief8745c2009-10-01 15:44:12 -0700477 __mem_cgroup_insert_exceeded(mem, mz, mctz, excess);
KAMEZAWA Hiroyuki4e649152009-10-01 15:44:11 -0700478 spin_unlock(&mctz->lock);
479 }
Balbir Singhf64c3f52009-09-23 15:56:37 -0700480 }
481}
482
483static void mem_cgroup_remove_from_trees(struct mem_cgroup *mem)
484{
485 int node, zone;
486 struct mem_cgroup_per_zone *mz;
487 struct mem_cgroup_tree_per_zone *mctz;
488
489 for_each_node_state(node, N_POSSIBLE) {
490 for (zone = 0; zone < MAX_NR_ZONES; zone++) {
491 mz = mem_cgroup_zoneinfo(mem, node, zone);
492 mctz = soft_limit_tree_node_zone(node, zone);
493 mem_cgroup_remove_exceeded(mem, mz, mctz);
494 }
495 }
496}
497
Balbir Singh4e416952009-09-23 15:56:39 -0700498static struct mem_cgroup_per_zone *
499__mem_cgroup_largest_soft_limit_node(struct mem_cgroup_tree_per_zone *mctz)
500{
501 struct rb_node *rightmost = NULL;
KAMEZAWA Hiroyuki26251ea2009-10-01 15:44:08 -0700502 struct mem_cgroup_per_zone *mz;
Balbir Singh4e416952009-09-23 15:56:39 -0700503
504retry:
KAMEZAWA Hiroyuki26251ea2009-10-01 15:44:08 -0700505 mz = NULL;
Balbir Singh4e416952009-09-23 15:56:39 -0700506 rightmost = rb_last(&mctz->rb_root);
507 if (!rightmost)
508 goto done; /* Nothing to reclaim from */
509
510 mz = rb_entry(rightmost, struct mem_cgroup_per_zone, tree_node);
511 /*
512 * Remove the node now but someone else can add it back,
513 * we will to add it back at the end of reclaim to its correct
514 * position in the tree.
515 */
516 __mem_cgroup_remove_exceeded(mz->mem, mz, mctz);
517 if (!res_counter_soft_limit_excess(&mz->mem->res) ||
518 !css_tryget(&mz->mem->css))
519 goto retry;
520done:
521 return mz;
522}
523
524static struct mem_cgroup_per_zone *
525mem_cgroup_largest_soft_limit_node(struct mem_cgroup_tree_per_zone *mctz)
526{
527 struct mem_cgroup_per_zone *mz;
528
529 spin_lock(&mctz->lock);
530 mz = __mem_cgroup_largest_soft_limit_node(mctz);
531 spin_unlock(&mctz->lock);
532 return mz;
533}
534
KAMEZAWA Hiroyuki711d3d22010-10-27 15:33:42 -0700535/*
536 * Implementation Note: reading percpu statistics for memcg.
537 *
538 * Both of vmstat[] and percpu_counter has threshold and do periodic
539 * synchronization to implement "quick" read. There are trade-off between
540 * reading cost and precision of value. Then, we may have a chance to implement
541 * a periodic synchronizion of counter in memcg's counter.
542 *
543 * But this _read() function is used for user interface now. The user accounts
544 * memory usage by memory cgroup and he _always_ requires exact value because
545 * he accounts memory. Even if we provide quick-and-fuzzy read, we always
546 * have to visit all online cpus and make sum. So, for now, unnecessary
547 * synchronization is not implemented. (just implemented for cpu hotplug)
548 *
549 * If there are kernel internal actions which can make use of some not-exact
550 * value, and reading all cpu value can be performance bottleneck in some
551 * common workload, threashold and synchonization as vmstat[] should be
552 * implemented.
553 */
Johannes Weiner7a159cc2011-03-23 16:42:38 -0700554static long mem_cgroup_read_stat(struct mem_cgroup *mem,
555 enum mem_cgroup_stat_index idx)
KAMEZAWA Hiroyukic62b1a32010-03-10 15:22:29 -0800556{
Johannes Weiner7a159cc2011-03-23 16:42:38 -0700557 long val = 0;
KAMEZAWA Hiroyukic62b1a32010-03-10 15:22:29 -0800558 int cpu;
KAMEZAWA Hiroyukic62b1a32010-03-10 15:22:29 -0800559
KAMEZAWA Hiroyuki711d3d22010-10-27 15:33:42 -0700560 get_online_cpus();
561 for_each_online_cpu(cpu)
KAMEZAWA Hiroyukic62b1a32010-03-10 15:22:29 -0800562 val += per_cpu(mem->stat->count[idx], cpu);
KAMEZAWA Hiroyuki711d3d22010-10-27 15:33:42 -0700563#ifdef CONFIG_HOTPLUG_CPU
564 spin_lock(&mem->pcp_counter_lock);
565 val += mem->nocpu_base.count[idx];
566 spin_unlock(&mem->pcp_counter_lock);
567#endif
568 put_online_cpus();
KAMEZAWA Hiroyukic62b1a32010-03-10 15:22:29 -0800569 return val;
570}
571
Johannes Weiner7a159cc2011-03-23 16:42:38 -0700572static long mem_cgroup_local_usage(struct mem_cgroup *mem)
KAMEZAWA Hiroyukic62b1a32010-03-10 15:22:29 -0800573{
Johannes Weiner7a159cc2011-03-23 16:42:38 -0700574 long ret;
KAMEZAWA Hiroyukic62b1a32010-03-10 15:22:29 -0800575
576 ret = mem_cgroup_read_stat(mem, MEM_CGROUP_STAT_RSS);
577 ret += mem_cgroup_read_stat(mem, MEM_CGROUP_STAT_CACHE);
578 return ret;
579}
580
Balbir Singh0c3e73e2009-09-23 15:56:42 -0700581static void mem_cgroup_swap_statistics(struct mem_cgroup *mem,
582 bool charge)
583{
584 int val = (charge) ? 1 : -1;
KAMEZAWA Hiroyukic62b1a32010-03-10 15:22:29 -0800585 this_cpu_add(mem->stat->count[MEM_CGROUP_STAT_SWAPOUT], val);
Balbir Singh0c3e73e2009-09-23 15:56:42 -0700586}
587
Johannes Weinere9f89742011-03-23 16:42:37 -0700588static unsigned long mem_cgroup_read_events(struct mem_cgroup *mem,
589 enum mem_cgroup_events_index idx)
590{
591 unsigned long val = 0;
592 int cpu;
593
594 for_each_online_cpu(cpu)
595 val += per_cpu(mem->stat->events[idx], cpu);
596#ifdef CONFIG_HOTPLUG_CPU
597 spin_lock(&mem->pcp_counter_lock);
598 val += mem->nocpu_base.events[idx];
599 spin_unlock(&mem->pcp_counter_lock);
600#endif
601 return val;
602}
603
KAMEZAWA Hiroyukic05555b2008-10-18 20:28:11 -0700604static void mem_cgroup_charge_statistics(struct mem_cgroup *mem,
KAMEZAWA Hiroyukie401f172011-01-20 14:44:23 -0800605 bool file, int nr_pages)
KAMEZAWA Hiroyukid52aa412008-02-07 00:14:24 -0800606{
KAMEZAWA Hiroyukic62b1a32010-03-10 15:22:29 -0800607 preempt_disable();
608
KAMEZAWA Hiroyukie401f172011-01-20 14:44:23 -0800609 if (file)
610 __this_cpu_add(mem->stat->count[MEM_CGROUP_STAT_CACHE], nr_pages);
KAMEZAWA Hiroyukid52aa412008-02-07 00:14:24 -0800611 else
KAMEZAWA Hiroyukie401f172011-01-20 14:44:23 -0800612 __this_cpu_add(mem->stat->count[MEM_CGROUP_STAT_RSS], nr_pages);
Balaji Rao55e462b2008-05-01 04:35:12 -0700613
KAMEZAWA Hiroyukie401f172011-01-20 14:44:23 -0800614 /* pagein of a big page is an event. So, ignore page size */
615 if (nr_pages > 0)
Johannes Weinere9f89742011-03-23 16:42:37 -0700616 __this_cpu_inc(mem->stat->events[MEM_CGROUP_EVENTS_PGPGIN]);
KAMEZAWA Hiroyuki3751d602011-02-01 15:52:45 -0800617 else {
Johannes Weinere9f89742011-03-23 16:42:37 -0700618 __this_cpu_inc(mem->stat->events[MEM_CGROUP_EVENTS_PGPGOUT]);
KAMEZAWA Hiroyuki3751d602011-02-01 15:52:45 -0800619 nr_pages = -nr_pages; /* for event */
620 }
KAMEZAWA Hiroyukie401f172011-01-20 14:44:23 -0800621
Johannes Weinere9f89742011-03-23 16:42:37 -0700622 __this_cpu_add(mem->stat->events[MEM_CGROUP_EVENTS_COUNT], nr_pages);
Kirill A. Shutemov2e72b632010-03-10 15:22:24 -0800623
KAMEZAWA Hiroyukic62b1a32010-03-10 15:22:29 -0800624 preempt_enable();
KAMEZAWA Hiroyuki6d12e2d2008-02-07 00:14:31 -0800625}
KAMEZAWA Hiroyukid52aa412008-02-07 00:14:24 -0800626
KAMEZAWA Hiroyuki14067bb2009-04-02 16:57:35 -0700627static unsigned long mem_cgroup_get_local_zonestat(struct mem_cgroup *mem,
Christoph Lameterb69408e2008-10-18 20:26:14 -0700628 enum lru_list idx)
KAMEZAWA Hiroyuki6d12e2d2008-02-07 00:14:31 -0800629{
630 int nid, zid;
631 struct mem_cgroup_per_zone *mz;
632 u64 total = 0;
633
634 for_each_online_node(nid)
635 for (zid = 0; zid < MAX_NR_ZONES; zid++) {
636 mz = mem_cgroup_zoneinfo(mem, nid, zid);
637 total += MEM_CGROUP_ZSTAT(mz, idx);
638 }
639 return total;
KAMEZAWA Hiroyukid52aa412008-02-07 00:14:24 -0800640}
641
Johannes Weiner7a159cc2011-03-23 16:42:38 -0700642static bool __memcg_event_check(struct mem_cgroup *mem, int target)
KAMEZAWA Hiroyukid2265e62010-03-10 15:22:31 -0800643{
Johannes Weiner7a159cc2011-03-23 16:42:38 -0700644 unsigned long val, next;
645
646 val = this_cpu_read(mem->stat->events[MEM_CGROUP_EVENTS_COUNT]);
647 next = this_cpu_read(mem->stat->targets[target]);
648 /* from time_after() in jiffies.h */
649 return ((long)next - (long)val < 0);
650}
651
652static void __mem_cgroup_target_update(struct mem_cgroup *mem, int target)
653{
654 unsigned long val, next;
KAMEZAWA Hiroyukid2265e62010-03-10 15:22:31 -0800655
Johannes Weinere9f89742011-03-23 16:42:37 -0700656 val = this_cpu_read(mem->stat->events[MEM_CGROUP_EVENTS_COUNT]);
KAMEZAWA Hiroyukid2265e62010-03-10 15:22:31 -0800657
Johannes Weiner7a159cc2011-03-23 16:42:38 -0700658 switch (target) {
659 case MEM_CGROUP_TARGET_THRESH:
660 next = val + THRESHOLDS_EVENTS_TARGET;
661 break;
662 case MEM_CGROUP_TARGET_SOFTLIMIT:
663 next = val + SOFTLIMIT_EVENTS_TARGET;
664 break;
665 default:
666 return;
667 }
668
669 this_cpu_write(mem->stat->targets[target], next);
KAMEZAWA Hiroyukid2265e62010-03-10 15:22:31 -0800670}
671
672/*
673 * Check events in order.
674 *
675 */
676static void memcg_check_events(struct mem_cgroup *mem, struct page *page)
677{
678 /* threshold event is triggered in finer grain than soft limit */
Johannes Weiner7a159cc2011-03-23 16:42:38 -0700679 if (unlikely(__memcg_event_check(mem, MEM_CGROUP_TARGET_THRESH))) {
KAMEZAWA Hiroyukid2265e62010-03-10 15:22:31 -0800680 mem_cgroup_threshold(mem);
Johannes Weiner7a159cc2011-03-23 16:42:38 -0700681 __mem_cgroup_target_update(mem, MEM_CGROUP_TARGET_THRESH);
682 if (unlikely(__memcg_event_check(mem,
683 MEM_CGROUP_TARGET_SOFTLIMIT))){
KAMEZAWA Hiroyukid2265e62010-03-10 15:22:31 -0800684 mem_cgroup_update_tree(mem, page);
Johannes Weiner7a159cc2011-03-23 16:42:38 -0700685 __mem_cgroup_target_update(mem,
686 MEM_CGROUP_TARGET_SOFTLIMIT);
687 }
KAMEZAWA Hiroyukid2265e62010-03-10 15:22:31 -0800688 }
689}
690
Hugh Dickinsd5b69e32008-03-04 14:29:10 -0800691static struct mem_cgroup *mem_cgroup_from_cont(struct cgroup *cont)
Balbir Singh8cdea7c2008-02-07 00:13:50 -0800692{
693 return container_of(cgroup_subsys_state(cont,
694 mem_cgroup_subsys_id), struct mem_cgroup,
695 css);
696}
697
Balbir Singhcf475ad2008-04-29 01:00:16 -0700698struct mem_cgroup *mem_cgroup_from_task(struct task_struct *p)
Pavel Emelianov78fb7462008-02-07 00:13:51 -0800699{
Balbir Singh31a78f22008-09-28 23:09:31 +0100700 /*
701 * mm_update_next_owner() may clear mm->owner to NULL
702 * if it races with swapoff, page migration, etc.
703 * So this can be called with p == NULL.
704 */
705 if (unlikely(!p))
706 return NULL;
707
Pavel Emelianov78fb7462008-02-07 00:13:51 -0800708 return container_of(task_subsys_state(p, mem_cgroup_subsys_id),
709 struct mem_cgroup, css);
710}
711
KAMEZAWA Hiroyuki54595fe2009-01-07 18:08:33 -0800712static struct mem_cgroup *try_get_mem_cgroup_from_mm(struct mm_struct *mm)
713{
714 struct mem_cgroup *mem = NULL;
KAMEZAWA Hiroyuki0b7f5692009-04-02 16:57:38 -0700715
716 if (!mm)
717 return NULL;
KAMEZAWA Hiroyuki54595fe2009-01-07 18:08:33 -0800718 /*
719 * Because we have no locks, mm->owner's may be being moved to other
720 * cgroup. We use css_tryget() here even if this looks
721 * pessimistic (rather than adding locks here).
722 */
723 rcu_read_lock();
724 do {
725 mem = mem_cgroup_from_task(rcu_dereference(mm->owner));
726 if (unlikely(!mem))
727 break;
728 } while (!css_tryget(&mem->css));
729 rcu_read_unlock();
730 return mem;
731}
732
KAMEZAWA Hiroyuki7d74b062010-10-27 15:33:41 -0700733/* The caller has to guarantee "mem" exists before calling this */
734static struct mem_cgroup *mem_cgroup_start_loop(struct mem_cgroup *mem)
KAMEZAWA Hiroyuki14067bb2009-04-02 16:57:35 -0700735{
KAMEZAWA Hiroyuki711d3d22010-10-27 15:33:42 -0700736 struct cgroup_subsys_state *css;
737 int found;
738
739 if (!mem) /* ROOT cgroup has the smallest ID */
740 return root_mem_cgroup; /*css_put/get against root is ignored*/
741 if (!mem->use_hierarchy) {
742 if (css_tryget(&mem->css))
743 return mem;
744 return NULL;
745 }
746 rcu_read_lock();
747 /*
748 * searching a memory cgroup which has the smallest ID under given
749 * ROOT cgroup. (ID >= 1)
750 */
751 css = css_get_next(&mem_cgroup_subsys, 1, &mem->css, &found);
752 if (css && css_tryget(css))
753 mem = container_of(css, struct mem_cgroup, css);
754 else
755 mem = NULL;
756 rcu_read_unlock();
757 return mem;
KAMEZAWA Hiroyuki14067bb2009-04-02 16:57:35 -0700758}
759
KAMEZAWA Hiroyuki7d74b062010-10-27 15:33:41 -0700760static struct mem_cgroup *mem_cgroup_get_next(struct mem_cgroup *iter,
761 struct mem_cgroup *root,
762 bool cond)
763{
764 int nextid = css_id(&iter->css) + 1;
765 int found;
766 int hierarchy_used;
767 struct cgroup_subsys_state *css;
768
769 hierarchy_used = iter->use_hierarchy;
770
771 css_put(&iter->css);
KAMEZAWA Hiroyuki711d3d22010-10-27 15:33:42 -0700772 /* If no ROOT, walk all, ignore hierarchy */
773 if (!cond || (root && !hierarchy_used))
KAMEZAWA Hiroyuki7d74b062010-10-27 15:33:41 -0700774 return NULL;
775
KAMEZAWA Hiroyuki711d3d22010-10-27 15:33:42 -0700776 if (!root)
777 root = root_mem_cgroup;
778
KAMEZAWA Hiroyuki7d74b062010-10-27 15:33:41 -0700779 do {
780 iter = NULL;
781 rcu_read_lock();
782
783 css = css_get_next(&mem_cgroup_subsys, nextid,
784 &root->css, &found);
785 if (css && css_tryget(css))
786 iter = container_of(css, struct mem_cgroup, css);
787 rcu_read_unlock();
788 /* If css is NULL, no more cgroups will be found */
789 nextid = found + 1;
790 } while (css && !iter);
791
792 return iter;
793}
794/*
795 * for_eacn_mem_cgroup_tree() for visiting all cgroup under tree. Please
796 * be careful that "break" loop is not allowed. We have reference count.
797 * Instead of that modify "cond" to be false and "continue" to exit the loop.
798 */
799#define for_each_mem_cgroup_tree_cond(iter, root, cond) \
800 for (iter = mem_cgroup_start_loop(root);\
801 iter != NULL;\
802 iter = mem_cgroup_get_next(iter, root, cond))
803
804#define for_each_mem_cgroup_tree(iter, root) \
805 for_each_mem_cgroup_tree_cond(iter, root, true)
806
KAMEZAWA Hiroyuki711d3d22010-10-27 15:33:42 -0700807#define for_each_mem_cgroup_all(iter) \
808 for_each_mem_cgroup_tree_cond(iter, NULL, true)
809
KAMEZAWA Hiroyuki7d74b062010-10-27 15:33:41 -0700810
Balbir Singh4b3bde42009-09-23 15:56:32 -0700811static inline bool mem_cgroup_is_root(struct mem_cgroup *mem)
812{
813 return (mem == root_mem_cgroup);
814}
815
KAMEZAWA Hiroyuki08e552c2009-01-07 18:08:01 -0800816/*
817 * Following LRU functions are allowed to be used without PCG_LOCK.
818 * Operations are called by routine of global LRU independently from memcg.
819 * What we have to take care of here is validness of pc->mem_cgroup.
820 *
821 * Changes to pc->mem_cgroup happens when
822 * 1. charge
823 * 2. moving account
824 * In typical case, "charge" is done before add-to-lru. Exception is SwapCache.
825 * It is added to LRU before charge.
826 * If PCG_USED bit is not set, page_cgroup is not added to this private LRU.
827 * When moving account, the page is not on LRU. It's isolated.
828 */
829
830void mem_cgroup_del_lru_list(struct page *page, enum lru_list lru)
KAMEZAWA Hiroyuki6d12e2d2008-02-07 00:14:31 -0800831{
KAMEZAWA Hiroyuki08e552c2009-01-07 18:08:01 -0800832 struct page_cgroup *pc;
KAMEZAWA Hiroyuki08e552c2009-01-07 18:08:01 -0800833 struct mem_cgroup_per_zone *mz;
Rik van Riel4f98a2f2008-10-18 20:26:32 -0700834
Hirokazu Takahashif8d665422009-01-07 18:08:02 -0800835 if (mem_cgroup_disabled())
KAMEZAWA Hiroyuki08e552c2009-01-07 18:08:01 -0800836 return;
837 pc = lookup_page_cgroup(page);
838 /* can happen while we handle swapcache. */
Balbir Singh4b3bde42009-09-23 15:56:32 -0700839 if (!TestClearPageCgroupAcctLRU(pc))
KAMEZAWA Hiroyuki08e552c2009-01-07 18:08:01 -0800840 return;
Balbir Singh4b3bde42009-09-23 15:56:32 -0700841 VM_BUG_ON(!pc->mem_cgroup);
KAMEZAWA Hiroyuki544122e2009-01-07 18:08:34 -0800842 /*
843 * We don't check PCG_USED bit. It's cleared when the "page" is finally
844 * removed from global LRU.
845 */
Johannes Weiner97a6c372011-03-23 16:42:27 -0700846 mz = page_cgroup_zoneinfo(pc->mem_cgroup, page);
KAMEZAWA Hiroyukiece35ca2011-01-20 14:44:24 -0800847 /* huge page split is done under lru_lock. so, we have no races. */
848 MEM_CGROUP_ZSTAT(mz, lru) -= 1 << compound_order(page);
Balbir Singh4b3bde42009-09-23 15:56:32 -0700849 if (mem_cgroup_is_root(pc->mem_cgroup))
850 return;
851 VM_BUG_ON(list_empty(&pc->lru));
KAMEZAWA Hiroyuki08e552c2009-01-07 18:08:01 -0800852 list_del_init(&pc->lru);
KAMEZAWA Hiroyuki6d12e2d2008-02-07 00:14:31 -0800853}
854
KAMEZAWA Hiroyuki08e552c2009-01-07 18:08:01 -0800855void mem_cgroup_del_lru(struct page *page)
KAMEZAWA Hiroyuki6d12e2d2008-02-07 00:14:31 -0800856{
KAMEZAWA Hiroyuki08e552c2009-01-07 18:08:01 -0800857 mem_cgroup_del_lru_list(page, page_lru(page));
KAMEZAWA Hiroyuki6d12e2d2008-02-07 00:14:31 -0800858}
859
Minchan Kim3f58a822011-03-22 16:32:53 -0700860/*
861 * Writeback is about to end against a page which has been marked for immediate
862 * reclaim. If it still appears to be reclaimable, move it to the tail of the
863 * inactive list.
864 */
865void mem_cgroup_rotate_reclaimable_page(struct page *page)
866{
867 struct mem_cgroup_per_zone *mz;
868 struct page_cgroup *pc;
869 enum lru_list lru = page_lru(page);
870
871 if (mem_cgroup_disabled())
872 return;
873
874 pc = lookup_page_cgroup(page);
875 /* unused or root page is not rotated. */
876 if (!PageCgroupUsed(pc))
877 return;
878 /* Ensure pc->mem_cgroup is visible after reading PCG_USED. */
879 smp_rmb();
880 if (mem_cgroup_is_root(pc->mem_cgroup))
881 return;
Johannes Weiner97a6c372011-03-23 16:42:27 -0700882 mz = page_cgroup_zoneinfo(pc->mem_cgroup, page);
Minchan Kim3f58a822011-03-22 16:32:53 -0700883 list_move_tail(&pc->lru, &mz->lists[lru]);
884}
885
KAMEZAWA Hiroyuki08e552c2009-01-07 18:08:01 -0800886void mem_cgroup_rotate_lru_list(struct page *page, enum lru_list lru)
Balbir Singh66e17072008-02-07 00:13:56 -0800887{
KAMEZAWA Hiroyuki08e552c2009-01-07 18:08:01 -0800888 struct mem_cgroup_per_zone *mz;
889 struct page_cgroup *pc;
KAMEZAWA Hiroyuki6d12e2d2008-02-07 00:14:31 -0800890
Hirokazu Takahashif8d665422009-01-07 18:08:02 -0800891 if (mem_cgroup_disabled())
Lee Schermerhorn894bc312008-10-18 20:26:39 -0700892 return;
Christoph Lameterb69408e2008-10-18 20:26:14 -0700893
KAMEZAWA Hiroyuki08e552c2009-01-07 18:08:01 -0800894 pc = lookup_page_cgroup(page);
Balbir Singh4b3bde42009-09-23 15:56:32 -0700895 /* unused or root page is not rotated. */
Johannes Weiner713735b42011-01-20 14:44:31 -0800896 if (!PageCgroupUsed(pc))
897 return;
898 /* Ensure pc->mem_cgroup is visible after reading PCG_USED. */
899 smp_rmb();
900 if (mem_cgroup_is_root(pc->mem_cgroup))
KAMEZAWA Hiroyuki08e552c2009-01-07 18:08:01 -0800901 return;
Johannes Weiner97a6c372011-03-23 16:42:27 -0700902 mz = page_cgroup_zoneinfo(pc->mem_cgroup, page);
Christoph Lameterb69408e2008-10-18 20:26:14 -0700903 list_move(&pc->lru, &mz->lists[lru]);
Balbir Singh66e17072008-02-07 00:13:56 -0800904}
905
KAMEZAWA Hiroyuki08e552c2009-01-07 18:08:01 -0800906void mem_cgroup_add_lru_list(struct page *page, enum lru_list lru)
907{
908 struct page_cgroup *pc;
909 struct mem_cgroup_per_zone *mz;
910
Hirokazu Takahashif8d665422009-01-07 18:08:02 -0800911 if (mem_cgroup_disabled())
KAMEZAWA Hiroyuki08e552c2009-01-07 18:08:01 -0800912 return;
913 pc = lookup_page_cgroup(page);
Balbir Singh4b3bde42009-09-23 15:56:32 -0700914 VM_BUG_ON(PageCgroupAcctLRU(pc));
KAMEZAWA Hiroyuki08e552c2009-01-07 18:08:01 -0800915 if (!PageCgroupUsed(pc))
916 return;
Johannes Weiner713735b42011-01-20 14:44:31 -0800917 /* Ensure pc->mem_cgroup is visible after reading PCG_USED. */
918 smp_rmb();
Johannes Weiner97a6c372011-03-23 16:42:27 -0700919 mz = page_cgroup_zoneinfo(pc->mem_cgroup, page);
KAMEZAWA Hiroyukiece35ca2011-01-20 14:44:24 -0800920 /* huge page split is done under lru_lock. so, we have no races. */
921 MEM_CGROUP_ZSTAT(mz, lru) += 1 << compound_order(page);
Balbir Singh4b3bde42009-09-23 15:56:32 -0700922 SetPageCgroupAcctLRU(pc);
923 if (mem_cgroup_is_root(pc->mem_cgroup))
924 return;
KAMEZAWA Hiroyuki08e552c2009-01-07 18:08:01 -0800925 list_add(&pc->lru, &mz->lists[lru]);
926}
KAMEZAWA Hiroyuki544122e2009-01-07 18:08:34 -0800927
KAMEZAWA Hiroyuki08e552c2009-01-07 18:08:01 -0800928/*
KAMEZAWA Hiroyuki5a6475a2011-03-23 16:42:42 -0700929 * At handling SwapCache and other FUSE stuff, pc->mem_cgroup may be changed
930 * while it's linked to lru because the page may be reused after it's fully
931 * uncharged. To handle that, unlink page_cgroup from LRU when charge it again.
932 * It's done under lock_page and expected that zone->lru_lock isnever held.
KAMEZAWA Hiroyuki08e552c2009-01-07 18:08:01 -0800933 */
KAMEZAWA Hiroyuki5a6475a2011-03-23 16:42:42 -0700934static void mem_cgroup_lru_del_before_commit(struct page *page)
KAMEZAWA Hiroyuki08e552c2009-01-07 18:08:01 -0800935{
KAMEZAWA Hiroyuki544122e2009-01-07 18:08:34 -0800936 unsigned long flags;
937 struct zone *zone = page_zone(page);
938 struct page_cgroup *pc = lookup_page_cgroup(page);
939
KAMEZAWA Hiroyuki5a6475a2011-03-23 16:42:42 -0700940 /*
941 * Doing this check without taking ->lru_lock seems wrong but this
942 * is safe. Because if page_cgroup's USED bit is unset, the page
943 * will not be added to any memcg's LRU. If page_cgroup's USED bit is
944 * set, the commit after this will fail, anyway.
945 * This all charge/uncharge is done under some mutual execustion.
946 * So, we don't need to taking care of changes in USED bit.
947 */
948 if (likely(!PageLRU(page)))
949 return;
950
KAMEZAWA Hiroyuki544122e2009-01-07 18:08:34 -0800951 spin_lock_irqsave(&zone->lru_lock, flags);
952 /*
953 * Forget old LRU when this page_cgroup is *not* used. This Used bit
954 * is guarded by lock_page() because the page is SwapCache.
955 */
956 if (!PageCgroupUsed(pc))
957 mem_cgroup_del_lru_list(page, page_lru(page));
958 spin_unlock_irqrestore(&zone->lru_lock, flags);
KAMEZAWA Hiroyuki08e552c2009-01-07 18:08:01 -0800959}
960
KAMEZAWA Hiroyuki5a6475a2011-03-23 16:42:42 -0700961static void mem_cgroup_lru_add_after_commit(struct page *page)
KAMEZAWA Hiroyuki544122e2009-01-07 18:08:34 -0800962{
963 unsigned long flags;
964 struct zone *zone = page_zone(page);
965 struct page_cgroup *pc = lookup_page_cgroup(page);
966
KAMEZAWA Hiroyuki5a6475a2011-03-23 16:42:42 -0700967 /* taking care of that the page is added to LRU while we commit it */
968 if (likely(!PageLRU(page)))
969 return;
KAMEZAWA Hiroyuki544122e2009-01-07 18:08:34 -0800970 spin_lock_irqsave(&zone->lru_lock, flags);
971 /* link when the page is linked to LRU but page_cgroup isn't */
Balbir Singh4b3bde42009-09-23 15:56:32 -0700972 if (PageLRU(page) && !PageCgroupAcctLRU(pc))
KAMEZAWA Hiroyuki544122e2009-01-07 18:08:34 -0800973 mem_cgroup_add_lru_list(page, page_lru(page));
974 spin_unlock_irqrestore(&zone->lru_lock, flags);
975}
976
977
KAMEZAWA Hiroyuki08e552c2009-01-07 18:08:01 -0800978void mem_cgroup_move_lists(struct page *page,
979 enum lru_list from, enum lru_list to)
980{
Hirokazu Takahashif8d665422009-01-07 18:08:02 -0800981 if (mem_cgroup_disabled())
KAMEZAWA Hiroyuki08e552c2009-01-07 18:08:01 -0800982 return;
983 mem_cgroup_del_lru_list(page, from);
984 mem_cgroup_add_lru_list(page, to);
985}
986
David Rientjes4c4a2212008-02-07 00:14:06 -0800987int task_in_mem_cgroup(struct task_struct *task, const struct mem_cgroup *mem)
988{
989 int ret;
KAMEZAWA Hiroyuki0b7f5692009-04-02 16:57:38 -0700990 struct mem_cgroup *curr = NULL;
KAMEZAWA Hiroyuki158e0a22010-08-10 18:03:00 -0700991 struct task_struct *p;
David Rientjes4c4a2212008-02-07 00:14:06 -0800992
KAMEZAWA Hiroyuki158e0a22010-08-10 18:03:00 -0700993 p = find_lock_task_mm(task);
994 if (!p)
995 return 0;
996 curr = try_get_mem_cgroup_from_mm(p->mm);
997 task_unlock(p);
KAMEZAWA Hiroyuki0b7f5692009-04-02 16:57:38 -0700998 if (!curr)
999 return 0;
Daisuke Nishimurad31f56d2009-12-15 16:47:12 -08001000 /*
1001 * We should check use_hierarchy of "mem" not "curr". Because checking
1002 * use_hierarchy of "curr" here make this function true if hierarchy is
1003 * enabled in "curr" and "curr" is a child of "mem" in *cgroup*
1004 * hierarchy(even if use_hierarchy is disabled in "mem").
1005 */
1006 if (mem->use_hierarchy)
KAMEZAWA Hiroyuki0b7f5692009-04-02 16:57:38 -07001007 ret = css_is_ancestor(&curr->css, &mem->css);
1008 else
1009 ret = (curr == mem);
1010 css_put(&curr->css);
David Rientjes4c4a2212008-02-07 00:14:06 -08001011 return ret;
1012}
1013
KOSAKI Motohiroc772be92009-01-07 18:08:25 -08001014static int calc_inactive_ratio(struct mem_cgroup *memcg, unsigned long *present_pages)
KOSAKI Motohiro14797e22009-01-07 18:08:18 -08001015{
1016 unsigned long active;
1017 unsigned long inactive;
KOSAKI Motohiroc772be92009-01-07 18:08:25 -08001018 unsigned long gb;
1019 unsigned long inactive_ratio;
KOSAKI Motohiro14797e22009-01-07 18:08:18 -08001020
KAMEZAWA Hiroyuki14067bb2009-04-02 16:57:35 -07001021 inactive = mem_cgroup_get_local_zonestat(memcg, LRU_INACTIVE_ANON);
1022 active = mem_cgroup_get_local_zonestat(memcg, LRU_ACTIVE_ANON);
KOSAKI Motohiro14797e22009-01-07 18:08:18 -08001023
KOSAKI Motohiroc772be92009-01-07 18:08:25 -08001024 gb = (inactive + active) >> (30 - PAGE_SHIFT);
1025 if (gb)
1026 inactive_ratio = int_sqrt(10 * gb);
1027 else
1028 inactive_ratio = 1;
1029
1030 if (present_pages) {
1031 present_pages[0] = inactive;
1032 present_pages[1] = active;
1033 }
1034
1035 return inactive_ratio;
1036}
1037
1038int mem_cgroup_inactive_anon_is_low(struct mem_cgroup *memcg)
1039{
1040 unsigned long active;
1041 unsigned long inactive;
1042 unsigned long present_pages[2];
1043 unsigned long inactive_ratio;
1044
1045 inactive_ratio = calc_inactive_ratio(memcg, present_pages);
1046
1047 inactive = present_pages[0];
1048 active = present_pages[1];
1049
1050 if (inactive * inactive_ratio < active)
KOSAKI Motohiro14797e22009-01-07 18:08:18 -08001051 return 1;
1052
1053 return 0;
1054}
1055
Rik van Riel56e49d22009-06-16 15:32:28 -07001056int mem_cgroup_inactive_file_is_low(struct mem_cgroup *memcg)
1057{
1058 unsigned long active;
1059 unsigned long inactive;
1060
1061 inactive = mem_cgroup_get_local_zonestat(memcg, LRU_INACTIVE_FILE);
1062 active = mem_cgroup_get_local_zonestat(memcg, LRU_ACTIVE_FILE);
1063
1064 return (active > inactive);
1065}
1066
KOSAKI Motohiroa3d8e052009-01-07 18:08:19 -08001067unsigned long mem_cgroup_zone_nr_pages(struct mem_cgroup *memcg,
1068 struct zone *zone,
1069 enum lru_list lru)
1070{
KOSAKI Motohiro13d7e3a2010-08-10 18:03:06 -07001071 int nid = zone_to_nid(zone);
KOSAKI Motohiroa3d8e052009-01-07 18:08:19 -08001072 int zid = zone_idx(zone);
1073 struct mem_cgroup_per_zone *mz = mem_cgroup_zoneinfo(memcg, nid, zid);
1074
1075 return MEM_CGROUP_ZSTAT(mz, lru);
1076}
1077
KOSAKI Motohiro3e2f41f2009-01-07 18:08:20 -08001078struct zone_reclaim_stat *mem_cgroup_get_reclaim_stat(struct mem_cgroup *memcg,
1079 struct zone *zone)
1080{
KOSAKI Motohiro13d7e3a2010-08-10 18:03:06 -07001081 int nid = zone_to_nid(zone);
KOSAKI Motohiro3e2f41f2009-01-07 18:08:20 -08001082 int zid = zone_idx(zone);
1083 struct mem_cgroup_per_zone *mz = mem_cgroup_zoneinfo(memcg, nid, zid);
1084
1085 return &mz->reclaim_stat;
1086}
1087
1088struct zone_reclaim_stat *
1089mem_cgroup_get_reclaim_stat_from_page(struct page *page)
1090{
1091 struct page_cgroup *pc;
1092 struct mem_cgroup_per_zone *mz;
1093
1094 if (mem_cgroup_disabled())
1095 return NULL;
1096
1097 pc = lookup_page_cgroup(page);
Daisuke Nishimurabd112db2009-01-15 13:51:11 -08001098 if (!PageCgroupUsed(pc))
1099 return NULL;
Johannes Weiner713735b42011-01-20 14:44:31 -08001100 /* Ensure pc->mem_cgroup is visible after reading PCG_USED. */
1101 smp_rmb();
Johannes Weiner97a6c372011-03-23 16:42:27 -07001102 mz = page_cgroup_zoneinfo(pc->mem_cgroup, page);
KOSAKI Motohiro3e2f41f2009-01-07 18:08:20 -08001103 return &mz->reclaim_stat;
1104}
1105
Balbir Singh66e17072008-02-07 00:13:56 -08001106unsigned long mem_cgroup_isolate_pages(unsigned long nr_to_scan,
1107 struct list_head *dst,
1108 unsigned long *scanned, int order,
1109 int mode, struct zone *z,
1110 struct mem_cgroup *mem_cont,
Rik van Riel4f98a2f2008-10-18 20:26:32 -07001111 int active, int file)
Balbir Singh66e17072008-02-07 00:13:56 -08001112{
1113 unsigned long nr_taken = 0;
1114 struct page *page;
1115 unsigned long scan;
1116 LIST_HEAD(pc_list);
1117 struct list_head *src;
KAMEZAWA Hiroyukiff7283f2008-02-07 00:14:11 -08001118 struct page_cgroup *pc, *tmp;
KOSAKI Motohiro13d7e3a2010-08-10 18:03:06 -07001119 int nid = zone_to_nid(z);
KAMEZAWA Hiroyuki1ecaab22008-02-07 00:14:38 -08001120 int zid = zone_idx(z);
1121 struct mem_cgroup_per_zone *mz;
Johannes Weinerb7c46d12009-09-21 17:02:56 -07001122 int lru = LRU_FILE * file + active;
KAMEZAWA Hiroyuki2ffebca2009-06-17 16:27:21 -07001123 int ret;
Balbir Singh66e17072008-02-07 00:13:56 -08001124
Balbir Singhcf475ad2008-04-29 01:00:16 -07001125 BUG_ON(!mem_cont);
KAMEZAWA Hiroyuki1ecaab22008-02-07 00:14:38 -08001126 mz = mem_cgroup_zoneinfo(mem_cont, nid, zid);
Christoph Lameterb69408e2008-10-18 20:26:14 -07001127 src = &mz->lists[lru];
Balbir Singh66e17072008-02-07 00:13:56 -08001128
KAMEZAWA Hiroyukiff7283f2008-02-07 00:14:11 -08001129 scan = 0;
1130 list_for_each_entry_safe_reverse(pc, tmp, src, lru) {
Hugh Dickins436c65412008-02-07 00:14:12 -08001131 if (scan >= nr_to_scan)
KAMEZAWA Hiroyukiff7283f2008-02-07 00:14:11 -08001132 break;
KAMEZAWA Hiroyuki08e552c2009-01-07 18:08:01 -08001133
KAMEZAWA Hiroyuki52d4b9a2008-10-18 20:28:16 -07001134 if (unlikely(!PageCgroupUsed(pc)))
1135 continue;
Johannes Weiner5564e882011-03-23 16:42:29 -07001136
Johannes Weiner6b3ae582011-03-23 16:42:30 -07001137 page = lookup_cgroup_page(pc);
Johannes Weiner5564e882011-03-23 16:42:29 -07001138
Hugh Dickins436c65412008-02-07 00:14:12 -08001139 if (unlikely(!PageLRU(page)))
KAMEZAWA Hiroyukiff7283f2008-02-07 00:14:11 -08001140 continue;
KAMEZAWA Hiroyukiff7283f2008-02-07 00:14:11 -08001141
Hugh Dickins436c65412008-02-07 00:14:12 -08001142 scan++;
KAMEZAWA Hiroyuki2ffebca2009-06-17 16:27:21 -07001143 ret = __isolate_lru_page(page, mode, file);
1144 switch (ret) {
1145 case 0:
Balbir Singh66e17072008-02-07 00:13:56 -08001146 list_move(&page->lru, dst);
KAMEZAWA Hiroyuki2ffebca2009-06-17 16:27:21 -07001147 mem_cgroup_del_lru(page);
Rik van Riel2c888cf2011-01-13 15:47:13 -08001148 nr_taken += hpage_nr_pages(page);
KAMEZAWA Hiroyuki2ffebca2009-06-17 16:27:21 -07001149 break;
1150 case -EBUSY:
1151 /* we don't affect global LRU but rotate in our LRU */
1152 mem_cgroup_rotate_lru_list(page, page_lru(page));
1153 break;
1154 default:
1155 break;
Balbir Singh66e17072008-02-07 00:13:56 -08001156 }
1157 }
1158
Balbir Singh66e17072008-02-07 00:13:56 -08001159 *scanned = scan;
KOSAKI Motohirocc8e9702010-08-09 17:19:57 -07001160
1161 trace_mm_vmscan_memcg_isolate(0, nr_to_scan, scan, nr_taken,
1162 0, 0, 0, mode);
1163
Balbir Singh66e17072008-02-07 00:13:56 -08001164 return nr_taken;
1165}
1166
Balbir Singh6d61ef42009-01-07 18:08:06 -08001167#define mem_cgroup_from_res_counter(counter, member) \
1168 container_of(counter, struct mem_cgroup, member)
1169
Johannes Weiner19942822011-02-01 15:52:43 -08001170/**
Johannes Weiner9d11ea92011-03-23 16:42:21 -07001171 * mem_cgroup_margin - calculate chargeable space of a memory cgroup
1172 * @mem: the memory cgroup
Johannes Weiner19942822011-02-01 15:52:43 -08001173 *
Johannes Weiner9d11ea92011-03-23 16:42:21 -07001174 * Returns the maximum amount of memory @mem can be charged with, in
Johannes Weiner7ec99d62011-03-23 16:42:36 -07001175 * pages.
Johannes Weiner19942822011-02-01 15:52:43 -08001176 */
Johannes Weiner7ec99d62011-03-23 16:42:36 -07001177static unsigned long mem_cgroup_margin(struct mem_cgroup *mem)
Johannes Weiner19942822011-02-01 15:52:43 -08001178{
Johannes Weiner9d11ea92011-03-23 16:42:21 -07001179 unsigned long long margin;
1180
1181 margin = res_counter_margin(&mem->res);
1182 if (do_swap_account)
1183 margin = min(margin, res_counter_margin(&mem->memsw));
Johannes Weiner7ec99d62011-03-23 16:42:36 -07001184 return margin >> PAGE_SHIFT;
Johannes Weiner19942822011-02-01 15:52:43 -08001185}
1186
KOSAKI Motohiroa7885eb2009-01-07 18:08:24 -08001187static unsigned int get_swappiness(struct mem_cgroup *memcg)
1188{
1189 struct cgroup *cgrp = memcg->css.cgroup;
KOSAKI Motohiroa7885eb2009-01-07 18:08:24 -08001190
1191 /* root ? */
1192 if (cgrp->parent == NULL)
1193 return vm_swappiness;
1194
Johannes Weinerbf1ff262011-03-23 16:42:32 -07001195 return memcg->swappiness;
KOSAKI Motohiroa7885eb2009-01-07 18:08:24 -08001196}
1197
KAMEZAWA Hiroyuki32047e22010-10-27 15:33:40 -07001198static void mem_cgroup_start_move(struct mem_cgroup *mem)
1199{
1200 int cpu;
KAMEZAWA Hiroyuki1489eba2010-10-27 15:33:42 -07001201
1202 get_online_cpus();
1203 spin_lock(&mem->pcp_counter_lock);
1204 for_each_online_cpu(cpu)
KAMEZAWA Hiroyuki32047e22010-10-27 15:33:40 -07001205 per_cpu(mem->stat->count[MEM_CGROUP_ON_MOVE], cpu) += 1;
KAMEZAWA Hiroyuki1489eba2010-10-27 15:33:42 -07001206 mem->nocpu_base.count[MEM_CGROUP_ON_MOVE] += 1;
1207 spin_unlock(&mem->pcp_counter_lock);
1208 put_online_cpus();
KAMEZAWA Hiroyuki32047e22010-10-27 15:33:40 -07001209
1210 synchronize_rcu();
1211}
1212
1213static void mem_cgroup_end_move(struct mem_cgroup *mem)
1214{
1215 int cpu;
1216
1217 if (!mem)
1218 return;
KAMEZAWA Hiroyuki1489eba2010-10-27 15:33:42 -07001219 get_online_cpus();
1220 spin_lock(&mem->pcp_counter_lock);
1221 for_each_online_cpu(cpu)
KAMEZAWA Hiroyuki32047e22010-10-27 15:33:40 -07001222 per_cpu(mem->stat->count[MEM_CGROUP_ON_MOVE], cpu) -= 1;
KAMEZAWA Hiroyuki1489eba2010-10-27 15:33:42 -07001223 mem->nocpu_base.count[MEM_CGROUP_ON_MOVE] -= 1;
1224 spin_unlock(&mem->pcp_counter_lock);
1225 put_online_cpus();
KAMEZAWA Hiroyuki32047e22010-10-27 15:33:40 -07001226}
1227/*
1228 * 2 routines for checking "mem" is under move_account() or not.
1229 *
1230 * mem_cgroup_stealed() - checking a cgroup is mc.from or not. This is used
1231 * for avoiding race in accounting. If true,
1232 * pc->mem_cgroup may be overwritten.
1233 *
1234 * mem_cgroup_under_move() - checking a cgroup is mc.from or mc.to or
1235 * under hierarchy of moving cgroups. This is for
1236 * waiting at hith-memory prressure caused by "move".
1237 */
1238
1239static bool mem_cgroup_stealed(struct mem_cgroup *mem)
1240{
1241 VM_BUG_ON(!rcu_read_lock_held());
1242 return this_cpu_read(mem->stat->count[MEM_CGROUP_ON_MOVE]) > 0;
1243}
KAMEZAWA Hiroyuki4b534332010-08-10 18:02:57 -07001244
1245static bool mem_cgroup_under_move(struct mem_cgroup *mem)
1246{
KAMEZAWA Hiroyuki2bd9bb22010-08-10 18:02:58 -07001247 struct mem_cgroup *from;
1248 struct mem_cgroup *to;
KAMEZAWA Hiroyuki4b534332010-08-10 18:02:57 -07001249 bool ret = false;
KAMEZAWA Hiroyuki2bd9bb22010-08-10 18:02:58 -07001250 /*
1251 * Unlike task_move routines, we access mc.to, mc.from not under
1252 * mutual exclusion by cgroup_mutex. Here, we take spinlock instead.
1253 */
1254 spin_lock(&mc.lock);
1255 from = mc.from;
1256 to = mc.to;
1257 if (!from)
1258 goto unlock;
1259 if (from == mem || to == mem
1260 || (mem->use_hierarchy && css_is_ancestor(&from->css, &mem->css))
1261 || (mem->use_hierarchy && css_is_ancestor(&to->css, &mem->css)))
1262 ret = true;
1263unlock:
1264 spin_unlock(&mc.lock);
KAMEZAWA Hiroyuki4b534332010-08-10 18:02:57 -07001265 return ret;
1266}
1267
1268static bool mem_cgroup_wait_acct_move(struct mem_cgroup *mem)
1269{
1270 if (mc.moving_task && current != mc.moving_task) {
1271 if (mem_cgroup_under_move(mem)) {
1272 DEFINE_WAIT(wait);
1273 prepare_to_wait(&mc.waitq, &wait, TASK_INTERRUPTIBLE);
1274 /* moving charge context might have finished. */
1275 if (mc.moving_task)
1276 schedule();
1277 finish_wait(&mc.waitq, &wait);
1278 return true;
1279 }
1280 }
1281 return false;
1282}
1283
Balbir Singhe2224322009-04-02 16:57:39 -07001284/**
Kirill A. Shutemov6a6135b2010-03-10 15:22:25 -08001285 * mem_cgroup_print_oom_info: Called from OOM with tasklist_lock held in read mode.
Balbir Singhe2224322009-04-02 16:57:39 -07001286 * @memcg: The memory cgroup that went over limit
1287 * @p: Task that is going to be killed
1288 *
1289 * NOTE: @memcg and @p's mem_cgroup can be different when hierarchy is
1290 * enabled
1291 */
1292void mem_cgroup_print_oom_info(struct mem_cgroup *memcg, struct task_struct *p)
1293{
1294 struct cgroup *task_cgrp;
1295 struct cgroup *mem_cgrp;
1296 /*
1297 * Need a buffer in BSS, can't rely on allocations. The code relies
1298 * on the assumption that OOM is serialized for memory controller.
1299 * If this assumption is broken, revisit this code.
1300 */
1301 static char memcg_name[PATH_MAX];
1302 int ret;
1303
Daisuke Nishimurad31f56d2009-12-15 16:47:12 -08001304 if (!memcg || !p)
Balbir Singhe2224322009-04-02 16:57:39 -07001305 return;
1306
1307
1308 rcu_read_lock();
1309
1310 mem_cgrp = memcg->css.cgroup;
1311 task_cgrp = task_cgroup(p, mem_cgroup_subsys_id);
1312
1313 ret = cgroup_path(task_cgrp, memcg_name, PATH_MAX);
1314 if (ret < 0) {
1315 /*
1316 * Unfortunately, we are unable to convert to a useful name
1317 * But we'll still print out the usage information
1318 */
1319 rcu_read_unlock();
1320 goto done;
1321 }
1322 rcu_read_unlock();
1323
1324 printk(KERN_INFO "Task in %s killed", memcg_name);
1325
1326 rcu_read_lock();
1327 ret = cgroup_path(mem_cgrp, memcg_name, PATH_MAX);
1328 if (ret < 0) {
1329 rcu_read_unlock();
1330 goto done;
1331 }
1332 rcu_read_unlock();
1333
1334 /*
1335 * Continues from above, so we don't need an KERN_ level
1336 */
1337 printk(KERN_CONT " as a result of limit of %s\n", memcg_name);
1338done:
1339
1340 printk(KERN_INFO "memory: usage %llukB, limit %llukB, failcnt %llu\n",
1341 res_counter_read_u64(&memcg->res, RES_USAGE) >> 10,
1342 res_counter_read_u64(&memcg->res, RES_LIMIT) >> 10,
1343 res_counter_read_u64(&memcg->res, RES_FAILCNT));
1344 printk(KERN_INFO "memory+swap: usage %llukB, limit %llukB, "
1345 "failcnt %llu\n",
1346 res_counter_read_u64(&memcg->memsw, RES_USAGE) >> 10,
1347 res_counter_read_u64(&memcg->memsw, RES_LIMIT) >> 10,
1348 res_counter_read_u64(&memcg->memsw, RES_FAILCNT));
1349}
1350
KAMEZAWA Hiroyuki81d39c22009-04-02 16:57:36 -07001351/*
1352 * This function returns the number of memcg under hierarchy tree. Returns
1353 * 1(self count) if no children.
1354 */
1355static int mem_cgroup_count_children(struct mem_cgroup *mem)
1356{
1357 int num = 0;
KAMEZAWA Hiroyuki7d74b062010-10-27 15:33:41 -07001358 struct mem_cgroup *iter;
1359
1360 for_each_mem_cgroup_tree(iter, mem)
1361 num++;
KAMEZAWA Hiroyuki81d39c22009-04-02 16:57:36 -07001362 return num;
1363}
1364
Balbir Singh6d61ef42009-01-07 18:08:06 -08001365/*
David Rientjesa63d83f2010-08-09 17:19:46 -07001366 * Return the memory (and swap, if configured) limit for a memcg.
1367 */
1368u64 mem_cgroup_get_limit(struct mem_cgroup *memcg)
1369{
1370 u64 limit;
1371 u64 memsw;
1372
Johannes Weinerf3e8eb72011-01-13 15:47:39 -08001373 limit = res_counter_read_u64(&memcg->res, RES_LIMIT);
1374 limit += total_swap_pages << PAGE_SHIFT;
1375
David Rientjesa63d83f2010-08-09 17:19:46 -07001376 memsw = res_counter_read_u64(&memcg->memsw, RES_LIMIT);
1377 /*
1378 * If memsw is finite and limits the amount of swap space available
1379 * to this memcg, return that limit.
1380 */
1381 return min(limit, memsw);
1382}
1383
1384/*
KAMEZAWA Hiroyuki04046e12009-04-02 16:57:33 -07001385 * Visit the first child (need not be the first child as per the ordering
1386 * of the cgroup list, since we track last_scanned_child) of @mem and use
1387 * that to reclaim free pages from.
1388 */
1389static struct mem_cgroup *
1390mem_cgroup_select_victim(struct mem_cgroup *root_mem)
1391{
1392 struct mem_cgroup *ret = NULL;
1393 struct cgroup_subsys_state *css;
1394 int nextid, found;
1395
1396 if (!root_mem->use_hierarchy) {
1397 css_get(&root_mem->css);
1398 ret = root_mem;
1399 }
1400
1401 while (!ret) {
1402 rcu_read_lock();
1403 nextid = root_mem->last_scanned_child + 1;
1404 css = css_get_next(&mem_cgroup_subsys, nextid, &root_mem->css,
1405 &found);
1406 if (css && css_tryget(css))
1407 ret = container_of(css, struct mem_cgroup, css);
1408
1409 rcu_read_unlock();
1410 /* Updates scanning parameter */
KAMEZAWA Hiroyuki04046e12009-04-02 16:57:33 -07001411 if (!css) {
1412 /* this means start scan from ID:1 */
1413 root_mem->last_scanned_child = 0;
1414 } else
1415 root_mem->last_scanned_child = found;
KAMEZAWA Hiroyuki04046e12009-04-02 16:57:33 -07001416 }
1417
1418 return ret;
1419}
1420
1421/*
1422 * Scan the hierarchy if needed to reclaim memory. We remember the last child
1423 * we reclaimed from, so that we don't end up penalizing one child extensively
1424 * based on its position in the children list.
Balbir Singh6d61ef42009-01-07 18:08:06 -08001425 *
1426 * root_mem is the original ancestor that we've been reclaim from.
KAMEZAWA Hiroyuki04046e12009-04-02 16:57:33 -07001427 *
1428 * We give up and return to the caller when we visit root_mem twice.
1429 * (other groups can be removed while we're walking....)
KAMEZAWA Hiroyuki81d39c22009-04-02 16:57:36 -07001430 *
1431 * If shrink==true, for avoiding to free too much, this returns immedieately.
Balbir Singh6d61ef42009-01-07 18:08:06 -08001432 */
1433static int mem_cgroup_hierarchical_reclaim(struct mem_cgroup *root_mem,
Balbir Singh4e416952009-09-23 15:56:39 -07001434 struct zone *zone,
Balbir Singh75822b42009-09-23 15:56:38 -07001435 gfp_t gfp_mask,
1436 unsigned long reclaim_options)
Balbir Singh6d61ef42009-01-07 18:08:06 -08001437{
KAMEZAWA Hiroyuki04046e12009-04-02 16:57:33 -07001438 struct mem_cgroup *victim;
1439 int ret, total = 0;
1440 int loop = 0;
Balbir Singh75822b42009-09-23 15:56:38 -07001441 bool noswap = reclaim_options & MEM_CGROUP_RECLAIM_NOSWAP;
1442 bool shrink = reclaim_options & MEM_CGROUP_RECLAIM_SHRINK;
Balbir Singh4e416952009-09-23 15:56:39 -07001443 bool check_soft = reclaim_options & MEM_CGROUP_RECLAIM_SOFT;
Johannes Weiner9d11ea92011-03-23 16:42:21 -07001444 unsigned long excess;
1445
1446 excess = res_counter_soft_limit_excess(&root_mem->res) >> PAGE_SHIFT;
Balbir Singh6d61ef42009-01-07 18:08:06 -08001447
KAMEZAWA Hiroyuki22a668d2009-06-17 16:27:19 -07001448 /* If memsw_is_minimum==1, swap-out is of-no-use. */
1449 if (root_mem->memsw_is_minimum)
1450 noswap = true;
1451
Balbir Singh4e416952009-09-23 15:56:39 -07001452 while (1) {
KAMEZAWA Hiroyuki04046e12009-04-02 16:57:33 -07001453 victim = mem_cgroup_select_victim(root_mem);
Balbir Singh4e416952009-09-23 15:56:39 -07001454 if (victim == root_mem) {
KAMEZAWA Hiroyuki04046e12009-04-02 16:57:33 -07001455 loop++;
KAMEZAWA Hiroyukicdec2e42009-12-15 16:47:08 -08001456 if (loop >= 1)
1457 drain_all_stock_async();
Balbir Singh4e416952009-09-23 15:56:39 -07001458 if (loop >= 2) {
1459 /*
1460 * If we have not been able to reclaim
1461 * anything, it might because there are
1462 * no reclaimable pages under this hierarchy
1463 */
1464 if (!check_soft || !total) {
1465 css_put(&victim->css);
1466 break;
1467 }
1468 /*
Lucas De Marchi25985ed2011-03-30 22:57:33 -03001469 * We want to do more targeted reclaim.
Balbir Singh4e416952009-09-23 15:56:39 -07001470 * excess >> 2 is not to excessive so as to
1471 * reclaim too much, nor too less that we keep
1472 * coming back to reclaim from this cgroup
1473 */
1474 if (total >= (excess >> 2) ||
1475 (loop > MEM_CGROUP_MAX_RECLAIM_LOOPS)) {
1476 css_put(&victim->css);
1477 break;
1478 }
1479 }
1480 }
KAMEZAWA Hiroyukic62b1a32010-03-10 15:22:29 -08001481 if (!mem_cgroup_local_usage(victim)) {
KAMEZAWA Hiroyuki04046e12009-04-02 16:57:33 -07001482 /* this cgroup's local usage == 0 */
1483 css_put(&victim->css);
Balbir Singh6d61ef42009-01-07 18:08:06 -08001484 continue;
1485 }
KAMEZAWA Hiroyuki04046e12009-04-02 16:57:33 -07001486 /* we use swappiness of local cgroup */
Balbir Singh4e416952009-09-23 15:56:39 -07001487 if (check_soft)
1488 ret = mem_cgroup_shrink_node_zone(victim, gfp_mask,
KOSAKI Motohiro14fec792010-08-10 18:03:05 -07001489 noswap, get_swappiness(victim), zone);
Balbir Singh4e416952009-09-23 15:56:39 -07001490 else
1491 ret = try_to_free_mem_cgroup_pages(victim, gfp_mask,
1492 noswap, get_swappiness(victim));
KAMEZAWA Hiroyuki04046e12009-04-02 16:57:33 -07001493 css_put(&victim->css);
KAMEZAWA Hiroyuki81d39c22009-04-02 16:57:36 -07001494 /*
1495 * At shrinking usage, we can't check we should stop here or
1496 * reclaim more. It's depends on callers. last_scanned_child
1497 * will work enough for keeping fairness under tree.
1498 */
1499 if (shrink)
1500 return ret;
KAMEZAWA Hiroyuki04046e12009-04-02 16:57:33 -07001501 total += ret;
Balbir Singh4e416952009-09-23 15:56:39 -07001502 if (check_soft) {
Johannes Weiner9d11ea92011-03-23 16:42:21 -07001503 if (!res_counter_soft_limit_excess(&root_mem->res))
Balbir Singh4e416952009-09-23 15:56:39 -07001504 return total;
Johannes Weiner9d11ea92011-03-23 16:42:21 -07001505 } else if (mem_cgroup_margin(root_mem))
KAMEZAWA Hiroyuki04046e12009-04-02 16:57:33 -07001506 return 1 + total;
Balbir Singh6d61ef42009-01-07 18:08:06 -08001507 }
KAMEZAWA Hiroyuki04046e12009-04-02 16:57:33 -07001508 return total;
Balbir Singh6d61ef42009-01-07 18:08:06 -08001509}
1510
KAMEZAWA Hiroyuki867578c2010-03-10 15:22:39 -08001511/*
1512 * Check OOM-Killer is already running under our hierarchy.
1513 * If someone is running, return false.
1514 */
1515static bool mem_cgroup_oom_lock(struct mem_cgroup *mem)
1516{
KAMEZAWA Hiroyuki7d74b062010-10-27 15:33:41 -07001517 int x, lock_count = 0;
1518 struct mem_cgroup *iter;
KAMEZAWA Hiroyukia636b322009-01-07 18:08:08 -08001519
KAMEZAWA Hiroyuki7d74b062010-10-27 15:33:41 -07001520 for_each_mem_cgroup_tree(iter, mem) {
1521 x = atomic_inc_return(&iter->oom_lock);
1522 lock_count = max(x, lock_count);
1523 }
KAMEZAWA Hiroyuki867578c2010-03-10 15:22:39 -08001524
1525 if (lock_count == 1)
1526 return true;
1527 return false;
KAMEZAWA Hiroyukia636b322009-01-07 18:08:08 -08001528}
KAMEZAWA Hiroyuki0b7f5692009-04-02 16:57:38 -07001529
KAMEZAWA Hiroyuki7d74b062010-10-27 15:33:41 -07001530static int mem_cgroup_oom_unlock(struct mem_cgroup *mem)
KAMEZAWA Hiroyuki0b7f5692009-04-02 16:57:38 -07001531{
KAMEZAWA Hiroyuki7d74b062010-10-27 15:33:41 -07001532 struct mem_cgroup *iter;
1533
KAMEZAWA Hiroyuki867578c2010-03-10 15:22:39 -08001534 /*
1535 * When a new child is created while the hierarchy is under oom,
1536 * mem_cgroup_oom_lock() may not be called. We have to use
1537 * atomic_add_unless() here.
1538 */
KAMEZAWA Hiroyuki7d74b062010-10-27 15:33:41 -07001539 for_each_mem_cgroup_tree(iter, mem)
1540 atomic_add_unless(&iter->oom_lock, -1, 0);
KAMEZAWA Hiroyuki0b7f5692009-04-02 16:57:38 -07001541 return 0;
1542}
1543
KAMEZAWA Hiroyuki867578c2010-03-10 15:22:39 -08001544
1545static DEFINE_MUTEX(memcg_oom_mutex);
1546static DECLARE_WAIT_QUEUE_HEAD(memcg_oom_waitq);
1547
KAMEZAWA Hiroyukidc98df52010-05-26 14:42:36 -07001548struct oom_wait_info {
1549 struct mem_cgroup *mem;
1550 wait_queue_t wait;
1551};
1552
1553static int memcg_oom_wake_function(wait_queue_t *wait,
1554 unsigned mode, int sync, void *arg)
1555{
1556 struct mem_cgroup *wake_mem = (struct mem_cgroup *)arg;
1557 struct oom_wait_info *oom_wait_info;
1558
1559 oom_wait_info = container_of(wait, struct oom_wait_info, wait);
1560
1561 if (oom_wait_info->mem == wake_mem)
1562 goto wakeup;
1563 /* if no hierarchy, no match */
1564 if (!oom_wait_info->mem->use_hierarchy || !wake_mem->use_hierarchy)
1565 return 0;
1566 /*
1567 * Both of oom_wait_info->mem and wake_mem are stable under us.
1568 * Then we can use css_is_ancestor without taking care of RCU.
1569 */
1570 if (!css_is_ancestor(&oom_wait_info->mem->css, &wake_mem->css) &&
1571 !css_is_ancestor(&wake_mem->css, &oom_wait_info->mem->css))
1572 return 0;
1573
1574wakeup:
1575 return autoremove_wake_function(wait, mode, sync, arg);
1576}
1577
1578static void memcg_wakeup_oom(struct mem_cgroup *mem)
1579{
1580 /* for filtering, pass "mem" as argument. */
1581 __wake_up(&memcg_oom_waitq, TASK_NORMAL, 0, mem);
1582}
1583
KAMEZAWA Hiroyuki3c11ecf2010-05-26 14:42:37 -07001584static void memcg_oom_recover(struct mem_cgroup *mem)
1585{
KAMEZAWA Hiroyuki2bd9bb22010-08-10 18:02:58 -07001586 if (mem && atomic_read(&mem->oom_lock))
KAMEZAWA Hiroyuki3c11ecf2010-05-26 14:42:37 -07001587 memcg_wakeup_oom(mem);
1588}
1589
KAMEZAWA Hiroyuki867578c2010-03-10 15:22:39 -08001590/*
1591 * try to call OOM killer. returns false if we should exit memory-reclaim loop.
1592 */
1593bool mem_cgroup_handle_oom(struct mem_cgroup *mem, gfp_t mask)
1594{
KAMEZAWA Hiroyukidc98df52010-05-26 14:42:36 -07001595 struct oom_wait_info owait;
KAMEZAWA Hiroyuki3c11ecf2010-05-26 14:42:37 -07001596 bool locked, need_to_kill;
KAMEZAWA Hiroyuki867578c2010-03-10 15:22:39 -08001597
KAMEZAWA Hiroyukidc98df52010-05-26 14:42:36 -07001598 owait.mem = mem;
1599 owait.wait.flags = 0;
1600 owait.wait.func = memcg_oom_wake_function;
1601 owait.wait.private = current;
1602 INIT_LIST_HEAD(&owait.wait.task_list);
KAMEZAWA Hiroyuki3c11ecf2010-05-26 14:42:37 -07001603 need_to_kill = true;
KAMEZAWA Hiroyuki867578c2010-03-10 15:22:39 -08001604 /* At first, try to OOM lock hierarchy under mem.*/
1605 mutex_lock(&memcg_oom_mutex);
1606 locked = mem_cgroup_oom_lock(mem);
1607 /*
1608 * Even if signal_pending(), we can't quit charge() loop without
1609 * accounting. So, UNINTERRUPTIBLE is appropriate. But SIGKILL
1610 * under OOM is always welcomed, use TASK_KILLABLE here.
1611 */
KAMEZAWA Hiroyuki3c11ecf2010-05-26 14:42:37 -07001612 prepare_to_wait(&memcg_oom_waitq, &owait.wait, TASK_KILLABLE);
1613 if (!locked || mem->oom_kill_disable)
1614 need_to_kill = false;
1615 if (locked)
KAMEZAWA Hiroyuki9490ff22010-05-26 14:42:36 -07001616 mem_cgroup_oom_notify(mem);
KAMEZAWA Hiroyuki867578c2010-03-10 15:22:39 -08001617 mutex_unlock(&memcg_oom_mutex);
1618
KAMEZAWA Hiroyuki3c11ecf2010-05-26 14:42:37 -07001619 if (need_to_kill) {
1620 finish_wait(&memcg_oom_waitq, &owait.wait);
KAMEZAWA Hiroyuki867578c2010-03-10 15:22:39 -08001621 mem_cgroup_out_of_memory(mem, mask);
KAMEZAWA Hiroyuki3c11ecf2010-05-26 14:42:37 -07001622 } else {
KAMEZAWA Hiroyuki867578c2010-03-10 15:22:39 -08001623 schedule();
KAMEZAWA Hiroyukidc98df52010-05-26 14:42:36 -07001624 finish_wait(&memcg_oom_waitq, &owait.wait);
KAMEZAWA Hiroyuki867578c2010-03-10 15:22:39 -08001625 }
1626 mutex_lock(&memcg_oom_mutex);
1627 mem_cgroup_oom_unlock(mem);
KAMEZAWA Hiroyukidc98df52010-05-26 14:42:36 -07001628 memcg_wakeup_oom(mem);
KAMEZAWA Hiroyuki867578c2010-03-10 15:22:39 -08001629 mutex_unlock(&memcg_oom_mutex);
1630
1631 if (test_thread_flag(TIF_MEMDIE) || fatal_signal_pending(current))
1632 return false;
1633 /* Give chance to dying process */
1634 schedule_timeout(1);
1635 return true;
KAMEZAWA Hiroyuki0b7f5692009-04-02 16:57:38 -07001636}
1637
Balbir Singhd69b0422009-06-17 16:26:34 -07001638/*
1639 * Currently used to update mapped file statistics, but the routine can be
1640 * generalized to update other statistics as well.
KAMEZAWA Hiroyuki32047e22010-10-27 15:33:40 -07001641 *
1642 * Notes: Race condition
1643 *
1644 * We usually use page_cgroup_lock() for accessing page_cgroup member but
1645 * it tends to be costly. But considering some conditions, we doesn't need
1646 * to do so _always_.
1647 *
1648 * Considering "charge", lock_page_cgroup() is not required because all
1649 * file-stat operations happen after a page is attached to radix-tree. There
1650 * are no race with "charge".
1651 *
1652 * Considering "uncharge", we know that memcg doesn't clear pc->mem_cgroup
1653 * at "uncharge" intentionally. So, we always see valid pc->mem_cgroup even
1654 * if there are race with "uncharge". Statistics itself is properly handled
1655 * by flags.
1656 *
1657 * Considering "move", this is an only case we see a race. To make the race
1658 * small, we check MEM_CGROUP_ON_MOVE percpu value and detect there are
1659 * possibility of race condition. If there is, we take a lock.
Balbir Singhd69b0422009-06-17 16:26:34 -07001660 */
KAMEZAWA Hiroyuki26174ef2010-10-27 15:33:43 -07001661
Greg Thelen2a7106f2011-01-13 15:47:37 -08001662void mem_cgroup_update_page_stat(struct page *page,
1663 enum mem_cgroup_page_stat_item idx, int val)
Balbir Singhd69b0422009-06-17 16:26:34 -07001664{
1665 struct mem_cgroup *mem;
KAMEZAWA Hiroyuki32047e22010-10-27 15:33:40 -07001666 struct page_cgroup *pc = lookup_page_cgroup(page);
1667 bool need_unlock = false;
KAMEZAWA Hiroyukidbd4ea72011-01-13 15:47:38 -08001668 unsigned long uninitialized_var(flags);
Balbir Singhd69b0422009-06-17 16:26:34 -07001669
Balbir Singhd69b0422009-06-17 16:26:34 -07001670 if (unlikely(!pc))
1671 return;
1672
KAMEZAWA Hiroyuki32047e22010-10-27 15:33:40 -07001673 rcu_read_lock();
Balbir Singhd69b0422009-06-17 16:26:34 -07001674 mem = pc->mem_cgroup;
KAMEZAWA Hiroyuki32047e22010-10-27 15:33:40 -07001675 if (unlikely(!mem || !PageCgroupUsed(pc)))
1676 goto out;
1677 /* pc->mem_cgroup is unstable ? */
KAMEZAWA Hiroyukica3e0212011-01-20 14:44:24 -08001678 if (unlikely(mem_cgroup_stealed(mem)) || PageTransHuge(page)) {
KAMEZAWA Hiroyuki32047e22010-10-27 15:33:40 -07001679 /* take a lock against to access pc->mem_cgroup */
KAMEZAWA Hiroyukidbd4ea72011-01-13 15:47:38 -08001680 move_lock_page_cgroup(pc, &flags);
KAMEZAWA Hiroyuki32047e22010-10-27 15:33:40 -07001681 need_unlock = true;
1682 mem = pc->mem_cgroup;
1683 if (!mem || !PageCgroupUsed(pc))
1684 goto out;
1685 }
KAMEZAWA Hiroyuki26174ef2010-10-27 15:33:43 -07001686
KAMEZAWA Hiroyuki26174ef2010-10-27 15:33:43 -07001687 switch (idx) {
Greg Thelen2a7106f2011-01-13 15:47:37 -08001688 case MEMCG_NR_FILE_MAPPED:
KAMEZAWA Hiroyuki26174ef2010-10-27 15:33:43 -07001689 if (val > 0)
1690 SetPageCgroupFileMapped(pc);
1691 else if (!page_mapped(page))
KAMEZAWA Hiroyuki0c270f82010-10-27 15:33:39 -07001692 ClearPageCgroupFileMapped(pc);
Greg Thelen2a7106f2011-01-13 15:47:37 -08001693 idx = MEM_CGROUP_STAT_FILE_MAPPED;
KAMEZAWA Hiroyuki26174ef2010-10-27 15:33:43 -07001694 break;
1695 default:
1696 BUG();
KAMEZAWA Hiroyuki8725d542010-04-06 14:35:05 -07001697 }
Balbir Singhd69b0422009-06-17 16:26:34 -07001698
Greg Thelen2a7106f2011-01-13 15:47:37 -08001699 this_cpu_add(mem->stat->count[idx], val);
1700
KAMEZAWA Hiroyuki32047e22010-10-27 15:33:40 -07001701out:
1702 if (unlikely(need_unlock))
KAMEZAWA Hiroyukidbd4ea72011-01-13 15:47:38 -08001703 move_unlock_page_cgroup(pc, &flags);
KAMEZAWA Hiroyuki32047e22010-10-27 15:33:40 -07001704 rcu_read_unlock();
1705 return;
Balbir Singhd69b0422009-06-17 16:26:34 -07001706}
Greg Thelen2a7106f2011-01-13 15:47:37 -08001707EXPORT_SYMBOL(mem_cgroup_update_page_stat);
KAMEZAWA Hiroyuki26174ef2010-10-27 15:33:43 -07001708
KAMEZAWA Hiroyukif817ed42009-01-07 18:07:53 -08001709/*
KAMEZAWA Hiroyukicdec2e42009-12-15 16:47:08 -08001710 * size of first charge trial. "32" comes from vmscan.c's magic value.
1711 * TODO: maybe necessary to use big numbers in big irons.
1712 */
Johannes Weiner7ec99d62011-03-23 16:42:36 -07001713#define CHARGE_BATCH 32U
KAMEZAWA Hiroyukicdec2e42009-12-15 16:47:08 -08001714struct memcg_stock_pcp {
1715 struct mem_cgroup *cached; /* this never be root cgroup */
Johannes Weiner11c9ea42011-03-23 16:42:34 -07001716 unsigned int nr_pages;
KAMEZAWA Hiroyukicdec2e42009-12-15 16:47:08 -08001717 struct work_struct work;
1718};
1719static DEFINE_PER_CPU(struct memcg_stock_pcp, memcg_stock);
1720static atomic_t memcg_drain_count;
1721
1722/*
Johannes Weiner11c9ea42011-03-23 16:42:34 -07001723 * Try to consume stocked charge on this cpu. If success, one page is consumed
KAMEZAWA Hiroyukicdec2e42009-12-15 16:47:08 -08001724 * from local stock and true is returned. If the stock is 0 or charges from a
1725 * cgroup which is not current target, returns false. This stock will be
1726 * refilled.
1727 */
1728static bool consume_stock(struct mem_cgroup *mem)
1729{
1730 struct memcg_stock_pcp *stock;
1731 bool ret = true;
1732
1733 stock = &get_cpu_var(memcg_stock);
Johannes Weiner11c9ea42011-03-23 16:42:34 -07001734 if (mem == stock->cached && stock->nr_pages)
1735 stock->nr_pages--;
KAMEZAWA Hiroyukicdec2e42009-12-15 16:47:08 -08001736 else /* need to call res_counter_charge */
1737 ret = false;
1738 put_cpu_var(memcg_stock);
1739 return ret;
1740}
1741
1742/*
1743 * Returns stocks cached in percpu to res_counter and reset cached information.
1744 */
1745static void drain_stock(struct memcg_stock_pcp *stock)
1746{
1747 struct mem_cgroup *old = stock->cached;
1748
Johannes Weiner11c9ea42011-03-23 16:42:34 -07001749 if (stock->nr_pages) {
1750 unsigned long bytes = stock->nr_pages * PAGE_SIZE;
1751
1752 res_counter_uncharge(&old->res, bytes);
KAMEZAWA Hiroyukicdec2e42009-12-15 16:47:08 -08001753 if (do_swap_account)
Johannes Weiner11c9ea42011-03-23 16:42:34 -07001754 res_counter_uncharge(&old->memsw, bytes);
1755 stock->nr_pages = 0;
KAMEZAWA Hiroyukicdec2e42009-12-15 16:47:08 -08001756 }
1757 stock->cached = NULL;
KAMEZAWA Hiroyukicdec2e42009-12-15 16:47:08 -08001758}
1759
1760/*
1761 * This must be called under preempt disabled or must be called by
1762 * a thread which is pinned to local cpu.
1763 */
1764static void drain_local_stock(struct work_struct *dummy)
1765{
1766 struct memcg_stock_pcp *stock = &__get_cpu_var(memcg_stock);
1767 drain_stock(stock);
1768}
1769
1770/*
1771 * Cache charges(val) which is from res_counter, to local per_cpu area.
Greg Thelen320cc512010-03-15 15:27:28 +01001772 * This will be consumed by consume_stock() function, later.
KAMEZAWA Hiroyukicdec2e42009-12-15 16:47:08 -08001773 */
Johannes Weiner11c9ea42011-03-23 16:42:34 -07001774static void refill_stock(struct mem_cgroup *mem, unsigned int nr_pages)
KAMEZAWA Hiroyukicdec2e42009-12-15 16:47:08 -08001775{
1776 struct memcg_stock_pcp *stock = &get_cpu_var(memcg_stock);
1777
1778 if (stock->cached != mem) { /* reset if necessary */
1779 drain_stock(stock);
1780 stock->cached = mem;
1781 }
Johannes Weiner11c9ea42011-03-23 16:42:34 -07001782 stock->nr_pages += nr_pages;
KAMEZAWA Hiroyukicdec2e42009-12-15 16:47:08 -08001783 put_cpu_var(memcg_stock);
1784}
1785
1786/*
1787 * Tries to drain stocked charges in other cpus. This function is asynchronous
1788 * and just put a work per cpu for draining localy on each cpu. Caller can
1789 * expects some charges will be back to res_counter later but cannot wait for
1790 * it.
1791 */
1792static void drain_all_stock_async(void)
1793{
1794 int cpu;
1795 /* This function is for scheduling "drain" in asynchronous way.
1796 * The result of "drain" is not directly handled by callers. Then,
1797 * if someone is calling drain, we don't have to call drain more.
1798 * Anyway, WORK_STRUCT_PENDING check in queue_work_on() will catch if
1799 * there is a race. We just do loose check here.
1800 */
1801 if (atomic_read(&memcg_drain_count))
1802 return;
1803 /* Notify other cpus that system-wide "drain" is running */
1804 atomic_inc(&memcg_drain_count);
1805 get_online_cpus();
1806 for_each_online_cpu(cpu) {
1807 struct memcg_stock_pcp *stock = &per_cpu(memcg_stock, cpu);
1808 schedule_work_on(cpu, &stock->work);
1809 }
1810 put_online_cpus();
1811 atomic_dec(&memcg_drain_count);
1812 /* We don't wait for flush_work */
1813}
1814
1815/* This is a synchronous drain interface. */
1816static void drain_all_stock_sync(void)
1817{
1818 /* called when force_empty is called */
1819 atomic_inc(&memcg_drain_count);
1820 schedule_on_each_cpu(drain_local_stock);
1821 atomic_dec(&memcg_drain_count);
1822}
1823
KAMEZAWA Hiroyuki711d3d22010-10-27 15:33:42 -07001824/*
1825 * This function drains percpu counter value from DEAD cpu and
1826 * move it to local cpu. Note that this function can be preempted.
1827 */
1828static void mem_cgroup_drain_pcp_counter(struct mem_cgroup *mem, int cpu)
1829{
1830 int i;
1831
1832 spin_lock(&mem->pcp_counter_lock);
1833 for (i = 0; i < MEM_CGROUP_STAT_DATA; i++) {
Johannes Weiner7a159cc2011-03-23 16:42:38 -07001834 long x = per_cpu(mem->stat->count[i], cpu);
KAMEZAWA Hiroyuki711d3d22010-10-27 15:33:42 -07001835
1836 per_cpu(mem->stat->count[i], cpu) = 0;
1837 mem->nocpu_base.count[i] += x;
1838 }
Johannes Weinere9f89742011-03-23 16:42:37 -07001839 for (i = 0; i < MEM_CGROUP_EVENTS_NSTATS; i++) {
1840 unsigned long x = per_cpu(mem->stat->events[i], cpu);
1841
1842 per_cpu(mem->stat->events[i], cpu) = 0;
1843 mem->nocpu_base.events[i] += x;
1844 }
KAMEZAWA Hiroyuki1489eba2010-10-27 15:33:42 -07001845 /* need to clear ON_MOVE value, works as a kind of lock. */
1846 per_cpu(mem->stat->count[MEM_CGROUP_ON_MOVE], cpu) = 0;
1847 spin_unlock(&mem->pcp_counter_lock);
1848}
1849
1850static void synchronize_mem_cgroup_on_move(struct mem_cgroup *mem, int cpu)
1851{
1852 int idx = MEM_CGROUP_ON_MOVE;
1853
1854 spin_lock(&mem->pcp_counter_lock);
1855 per_cpu(mem->stat->count[idx], cpu) = mem->nocpu_base.count[idx];
KAMEZAWA Hiroyuki711d3d22010-10-27 15:33:42 -07001856 spin_unlock(&mem->pcp_counter_lock);
1857}
1858
1859static int __cpuinit memcg_cpu_hotplug_callback(struct notifier_block *nb,
KAMEZAWA Hiroyukicdec2e42009-12-15 16:47:08 -08001860 unsigned long action,
1861 void *hcpu)
1862{
1863 int cpu = (unsigned long)hcpu;
1864 struct memcg_stock_pcp *stock;
KAMEZAWA Hiroyuki711d3d22010-10-27 15:33:42 -07001865 struct mem_cgroup *iter;
KAMEZAWA Hiroyukicdec2e42009-12-15 16:47:08 -08001866
KAMEZAWA Hiroyuki1489eba2010-10-27 15:33:42 -07001867 if ((action == CPU_ONLINE)) {
1868 for_each_mem_cgroup_all(iter)
1869 synchronize_mem_cgroup_on_move(iter, cpu);
1870 return NOTIFY_OK;
1871 }
1872
KAMEZAWA Hiroyuki711d3d22010-10-27 15:33:42 -07001873 if ((action != CPU_DEAD) || action != CPU_DEAD_FROZEN)
KAMEZAWA Hiroyukicdec2e42009-12-15 16:47:08 -08001874 return NOTIFY_OK;
KAMEZAWA Hiroyuki711d3d22010-10-27 15:33:42 -07001875
1876 for_each_mem_cgroup_all(iter)
1877 mem_cgroup_drain_pcp_counter(iter, cpu);
1878
KAMEZAWA Hiroyukicdec2e42009-12-15 16:47:08 -08001879 stock = &per_cpu(memcg_stock, cpu);
1880 drain_stock(stock);
1881 return NOTIFY_OK;
1882}
1883
KAMEZAWA Hiroyuki4b534332010-08-10 18:02:57 -07001884
1885/* See __mem_cgroup_try_charge() for details */
1886enum {
1887 CHARGE_OK, /* success */
1888 CHARGE_RETRY, /* need to retry but retry is not bad */
1889 CHARGE_NOMEM, /* we can't do more. return -ENOMEM */
1890 CHARGE_WOULDBLOCK, /* GFP_WAIT wasn't set and no enough res. */
1891 CHARGE_OOM_DIE, /* the current is killed because of OOM */
1892};
1893
Johannes Weiner7ec99d62011-03-23 16:42:36 -07001894static int mem_cgroup_do_charge(struct mem_cgroup *mem, gfp_t gfp_mask,
1895 unsigned int nr_pages, bool oom_check)
KAMEZAWA Hiroyuki4b534332010-08-10 18:02:57 -07001896{
Johannes Weiner7ec99d62011-03-23 16:42:36 -07001897 unsigned long csize = nr_pages * PAGE_SIZE;
KAMEZAWA Hiroyuki4b534332010-08-10 18:02:57 -07001898 struct mem_cgroup *mem_over_limit;
1899 struct res_counter *fail_res;
1900 unsigned long flags = 0;
1901 int ret;
1902
1903 ret = res_counter_charge(&mem->res, csize, &fail_res);
1904
1905 if (likely(!ret)) {
1906 if (!do_swap_account)
1907 return CHARGE_OK;
1908 ret = res_counter_charge(&mem->memsw, csize, &fail_res);
1909 if (likely(!ret))
1910 return CHARGE_OK;
1911
KAMEZAWA Hiroyuki01c88e22011-01-25 15:07:27 -08001912 res_counter_uncharge(&mem->res, csize);
KAMEZAWA Hiroyuki4b534332010-08-10 18:02:57 -07001913 mem_over_limit = mem_cgroup_from_res_counter(fail_res, memsw);
1914 flags |= MEM_CGROUP_RECLAIM_NOSWAP;
1915 } else
1916 mem_over_limit = mem_cgroup_from_res_counter(fail_res, res);
Johannes Weiner9221edb2011-02-01 15:52:42 -08001917 /*
Johannes Weiner7ec99d62011-03-23 16:42:36 -07001918 * nr_pages can be either a huge page (HPAGE_PMD_NR), a batch
1919 * of regular pages (CHARGE_BATCH), or a single regular page (1).
Johannes Weiner9221edb2011-02-01 15:52:42 -08001920 *
1921 * Never reclaim on behalf of optional batching, retry with a
1922 * single page instead.
1923 */
Johannes Weiner7ec99d62011-03-23 16:42:36 -07001924 if (nr_pages == CHARGE_BATCH)
KAMEZAWA Hiroyuki4b534332010-08-10 18:02:57 -07001925 return CHARGE_RETRY;
1926
1927 if (!(gfp_mask & __GFP_WAIT))
1928 return CHARGE_WOULDBLOCK;
1929
1930 ret = mem_cgroup_hierarchical_reclaim(mem_over_limit, NULL,
Johannes Weiner19942822011-02-01 15:52:43 -08001931 gfp_mask, flags);
Johannes Weiner7ec99d62011-03-23 16:42:36 -07001932 if (mem_cgroup_margin(mem_over_limit) >= nr_pages)
Johannes Weiner19942822011-02-01 15:52:43 -08001933 return CHARGE_RETRY;
KAMEZAWA Hiroyuki4b534332010-08-10 18:02:57 -07001934 /*
Johannes Weiner19942822011-02-01 15:52:43 -08001935 * Even though the limit is exceeded at this point, reclaim
1936 * may have been able to free some pages. Retry the charge
1937 * before killing the task.
1938 *
1939 * Only for regular pages, though: huge pages are rather
1940 * unlikely to succeed so close to the limit, and we fall back
1941 * to regular pages anyway in case of failure.
KAMEZAWA Hiroyuki4b534332010-08-10 18:02:57 -07001942 */
Johannes Weiner7ec99d62011-03-23 16:42:36 -07001943 if (nr_pages == 1 && ret)
KAMEZAWA Hiroyuki4b534332010-08-10 18:02:57 -07001944 return CHARGE_RETRY;
1945
1946 /*
1947 * At task move, charge accounts can be doubly counted. So, it's
1948 * better to wait until the end of task_move if something is going on.
1949 */
1950 if (mem_cgroup_wait_acct_move(mem_over_limit))
1951 return CHARGE_RETRY;
1952
1953 /* If we don't need to call oom-killer at el, return immediately */
1954 if (!oom_check)
1955 return CHARGE_NOMEM;
1956 /* check OOM */
1957 if (!mem_cgroup_handle_oom(mem_over_limit, gfp_mask))
1958 return CHARGE_OOM_DIE;
1959
1960 return CHARGE_RETRY;
1961}
1962
KAMEZAWA Hiroyukicdec2e42009-12-15 16:47:08 -08001963/*
KAMEZAWA Hiroyukif817ed42009-01-07 18:07:53 -08001964 * Unlike exported interface, "oom" parameter is added. if oom==true,
1965 * oom-killer can be invoked.
Balbir Singh8a9f3cc2008-02-07 00:13:53 -08001966 */
KAMEZAWA Hiroyukif817ed42009-01-07 18:07:53 -08001967static int __mem_cgroup_try_charge(struct mm_struct *mm,
Andrea Arcangeliec168512011-01-13 15:46:56 -08001968 gfp_t gfp_mask,
Johannes Weiner7ec99d62011-03-23 16:42:36 -07001969 unsigned int nr_pages,
1970 struct mem_cgroup **memcg,
1971 bool oom)
Balbir Singh8a9f3cc2008-02-07 00:13:53 -08001972{
Johannes Weiner7ec99d62011-03-23 16:42:36 -07001973 unsigned int batch = max(CHARGE_BATCH, nr_pages);
KAMEZAWA Hiroyuki4b534332010-08-10 18:02:57 -07001974 int nr_oom_retries = MEM_CGROUP_RECLAIM_RETRIES;
1975 struct mem_cgroup *mem = NULL;
1976 int ret;
KAMEZAWA Hiroyukia636b322009-01-07 18:08:08 -08001977
KAMEZAWA Hiroyuki867578c2010-03-10 15:22:39 -08001978 /*
1979 * Unlike gloval-vm's OOM-kill, we're not in memory shortage
1980 * in system level. So, allow to go ahead dying process in addition to
1981 * MEMDIE process.
1982 */
1983 if (unlikely(test_thread_flag(TIF_MEMDIE)
1984 || fatal_signal_pending(current)))
1985 goto bypass;
KAMEZAWA Hiroyukia636b322009-01-07 18:08:08 -08001986
Balbir Singh8a9f3cc2008-02-07 00:13:53 -08001987 /*
Hugh Dickins3be91272008-02-07 00:14:19 -08001988 * We always charge the cgroup the mm_struct belongs to.
1989 * The mm_struct's mem_cgroup changes on task migration if the
Balbir Singh8a9f3cc2008-02-07 00:13:53 -08001990 * thread group leader migrates. It's possible that mm is not
1991 * set, if so charge the init_mm (happens for pagecache usage).
1992 */
KAMEZAWA Hiroyukif75ca962010-08-10 18:03:02 -07001993 if (!*memcg && !mm)
1994 goto bypass;
1995again:
1996 if (*memcg) { /* css should be a valid one */
KAMEZAWA Hiroyuki4b534332010-08-10 18:02:57 -07001997 mem = *memcg;
KAMEZAWA Hiroyukif75ca962010-08-10 18:03:02 -07001998 VM_BUG_ON(css_is_removed(&mem->css));
1999 if (mem_cgroup_is_root(mem))
2000 goto done;
Johannes Weiner7ec99d62011-03-23 16:42:36 -07002001 if (nr_pages == 1 && consume_stock(mem))
KAMEZAWA Hiroyukif75ca962010-08-10 18:03:02 -07002002 goto done;
KAMEZAWA Hiroyuki7a81b882009-01-07 18:07:48 -08002003 css_get(&mem->css);
KAMEZAWA Hiroyuki4b534332010-08-10 18:02:57 -07002004 } else {
KAMEZAWA Hiroyukif75ca962010-08-10 18:03:02 -07002005 struct task_struct *p;
KAMEZAWA Hiroyuki54595fe2009-01-07 18:08:33 -08002006
KAMEZAWA Hiroyukif75ca962010-08-10 18:03:02 -07002007 rcu_read_lock();
2008 p = rcu_dereference(mm->owner);
KAMEZAWA Hiroyukif75ca962010-08-10 18:03:02 -07002009 /*
KAMEZAWA Hiroyukiebb76ce2010-12-29 14:07:11 -08002010 * Because we don't have task_lock(), "p" can exit.
2011 * In that case, "mem" can point to root or p can be NULL with
2012 * race with swapoff. Then, we have small risk of mis-accouning.
2013 * But such kind of mis-account by race always happens because
2014 * we don't have cgroup_mutex(). It's overkill and we allo that
2015 * small race, here.
2016 * (*) swapoff at el will charge against mm-struct not against
2017 * task-struct. So, mm->owner can be NULL.
KAMEZAWA Hiroyukif75ca962010-08-10 18:03:02 -07002018 */
2019 mem = mem_cgroup_from_task(p);
KAMEZAWA Hiroyukiebb76ce2010-12-29 14:07:11 -08002020 if (!mem || mem_cgroup_is_root(mem)) {
KAMEZAWA Hiroyukif75ca962010-08-10 18:03:02 -07002021 rcu_read_unlock();
2022 goto done;
2023 }
Johannes Weiner7ec99d62011-03-23 16:42:36 -07002024 if (nr_pages == 1 && consume_stock(mem)) {
KAMEZAWA Hiroyukif75ca962010-08-10 18:03:02 -07002025 /*
2026 * It seems dagerous to access memcg without css_get().
2027 * But considering how consume_stok works, it's not
2028 * necessary. If consume_stock success, some charges
2029 * from this memcg are cached on this cpu. So, we
2030 * don't need to call css_get()/css_tryget() before
2031 * calling consume_stock().
2032 */
2033 rcu_read_unlock();
2034 goto done;
2035 }
2036 /* after here, we may be blocked. we need to get refcnt */
2037 if (!css_tryget(&mem->css)) {
2038 rcu_read_unlock();
2039 goto again;
2040 }
2041 rcu_read_unlock();
2042 }
Balbir Singh8a9f3cc2008-02-07 00:13:53 -08002043
KAMEZAWA Hiroyuki4b534332010-08-10 18:02:57 -07002044 do {
2045 bool oom_check;
KAMEZAWA Hiroyuki7a81b882009-01-07 18:07:48 -08002046
KAMEZAWA Hiroyuki4b534332010-08-10 18:02:57 -07002047 /* If killed, bypass charge */
KAMEZAWA Hiroyukif75ca962010-08-10 18:03:02 -07002048 if (fatal_signal_pending(current)) {
2049 css_put(&mem->css);
KAMEZAWA Hiroyuki4b534332010-08-10 18:02:57 -07002050 goto bypass;
KAMEZAWA Hiroyukif75ca962010-08-10 18:03:02 -07002051 }
KAMEZAWA Hiroyukicdec2e42009-12-15 16:47:08 -08002052
KAMEZAWA Hiroyuki4b534332010-08-10 18:02:57 -07002053 oom_check = false;
2054 if (oom && !nr_oom_retries) {
2055 oom_check = true;
2056 nr_oom_retries = MEM_CGROUP_RECLAIM_RETRIES;
2057 }
Balbir Singh6d61ef42009-01-07 18:08:06 -08002058
Johannes Weiner7ec99d62011-03-23 16:42:36 -07002059 ret = mem_cgroup_do_charge(mem, gfp_mask, batch, oom_check);
KAMEZAWA Hiroyuki4b534332010-08-10 18:02:57 -07002060 switch (ret) {
2061 case CHARGE_OK:
2062 break;
2063 case CHARGE_RETRY: /* not in OOM situation but retry */
Johannes Weiner7ec99d62011-03-23 16:42:36 -07002064 batch = nr_pages;
KAMEZAWA Hiroyukif75ca962010-08-10 18:03:02 -07002065 css_put(&mem->css);
2066 mem = NULL;
2067 goto again;
KAMEZAWA Hiroyuki4b534332010-08-10 18:02:57 -07002068 case CHARGE_WOULDBLOCK: /* !__GFP_WAIT */
KAMEZAWA Hiroyukif75ca962010-08-10 18:03:02 -07002069 css_put(&mem->css);
KAMEZAWA Hiroyuki7a81b882009-01-07 18:07:48 -08002070 goto nomem;
KAMEZAWA Hiroyuki4b534332010-08-10 18:02:57 -07002071 case CHARGE_NOMEM: /* OOM routine works */
KAMEZAWA Hiroyukif75ca962010-08-10 18:03:02 -07002072 if (!oom) {
2073 css_put(&mem->css);
KAMEZAWA Hiroyuki867578c2010-03-10 15:22:39 -08002074 goto nomem;
KAMEZAWA Hiroyukif75ca962010-08-10 18:03:02 -07002075 }
KAMEZAWA Hiroyuki4b534332010-08-10 18:02:57 -07002076 /* If oom, we never return -ENOMEM */
2077 nr_oom_retries--;
2078 break;
2079 case CHARGE_OOM_DIE: /* Killed by OOM Killer */
KAMEZAWA Hiroyukif75ca962010-08-10 18:03:02 -07002080 css_put(&mem->css);
KAMEZAWA Hiroyuki867578c2010-03-10 15:22:39 -08002081 goto bypass;
Balbir Singh66e17072008-02-07 00:13:56 -08002082 }
KAMEZAWA Hiroyuki4b534332010-08-10 18:02:57 -07002083 } while (ret != CHARGE_OK);
2084
Johannes Weiner7ec99d62011-03-23 16:42:36 -07002085 if (batch > nr_pages)
2086 refill_stock(mem, batch - nr_pages);
KAMEZAWA Hiroyukif75ca962010-08-10 18:03:02 -07002087 css_put(&mem->css);
Balbir Singh0c3e73e2009-09-23 15:56:42 -07002088done:
KAMEZAWA Hiroyukif75ca962010-08-10 18:03:02 -07002089 *memcg = mem;
KAMEZAWA Hiroyuki7a81b882009-01-07 18:07:48 -08002090 return 0;
2091nomem:
KAMEZAWA Hiroyukif75ca962010-08-10 18:03:02 -07002092 *memcg = NULL;
KAMEZAWA Hiroyuki7a81b882009-01-07 18:07:48 -08002093 return -ENOMEM;
KAMEZAWA Hiroyuki867578c2010-03-10 15:22:39 -08002094bypass:
2095 *memcg = NULL;
2096 return 0;
KAMEZAWA Hiroyuki7a81b882009-01-07 18:07:48 -08002097}
Balbir Singh8a9f3cc2008-02-07 00:13:53 -08002098
KAMEZAWA Hiroyukia3b2d692009-04-02 16:57:45 -07002099/*
Daisuke Nishimuraa3032a22009-12-15 16:47:10 -08002100 * Somemtimes we have to undo a charge we got by try_charge().
2101 * This function is for that and do uncharge, put css's refcnt.
2102 * gotten by try_charge().
2103 */
Daisuke Nishimura854ffa82010-03-10 15:22:15 -08002104static void __mem_cgroup_cancel_charge(struct mem_cgroup *mem,
Johannes Weinere7018b8d2011-03-23 16:42:33 -07002105 unsigned int nr_pages)
Daisuke Nishimuraa3032a22009-12-15 16:47:10 -08002106{
2107 if (!mem_cgroup_is_root(mem)) {
Johannes Weinere7018b8d2011-03-23 16:42:33 -07002108 unsigned long bytes = nr_pages * PAGE_SIZE;
Daisuke Nishimura854ffa82010-03-10 15:22:15 -08002109
Johannes Weinere7018b8d2011-03-23 16:42:33 -07002110 res_counter_uncharge(&mem->res, bytes);
2111 if (do_swap_account)
2112 res_counter_uncharge(&mem->memsw, bytes);
2113 }
Daisuke Nishimuraa3032a22009-12-15 16:47:10 -08002114}
2115
2116/*
KAMEZAWA Hiroyukia3b2d692009-04-02 16:57:45 -07002117 * A helper function to get mem_cgroup from ID. must be called under
2118 * rcu_read_lock(). The caller must check css_is_removed() or some if
2119 * it's concern. (dropping refcnt from swap can be called against removed
2120 * memcg.)
2121 */
2122static struct mem_cgroup *mem_cgroup_lookup(unsigned short id)
2123{
2124 struct cgroup_subsys_state *css;
2125
2126 /* ID 0 is unused ID */
2127 if (!id)
2128 return NULL;
2129 css = css_lookup(&mem_cgroup_subsys, id);
2130 if (!css)
2131 return NULL;
2132 return container_of(css, struct mem_cgroup, css);
2133}
2134
Wu Fengguange42d9d52009-12-16 12:19:59 +01002135struct mem_cgroup *try_get_mem_cgroup_from_page(struct page *page)
KAMEZAWA Hiroyukib5a84312009-01-07 18:08:35 -08002136{
Wu Fengguange42d9d52009-12-16 12:19:59 +01002137 struct mem_cgroup *mem = NULL;
Daisuke Nishimura3c776e62009-04-02 16:57:43 -07002138 struct page_cgroup *pc;
KAMEZAWA Hiroyukia3b2d692009-04-02 16:57:45 -07002139 unsigned short id;
KAMEZAWA Hiroyukib5a84312009-01-07 18:08:35 -08002140 swp_entry_t ent;
2141
Daisuke Nishimura3c776e62009-04-02 16:57:43 -07002142 VM_BUG_ON(!PageLocked(page));
2143
Daisuke Nishimura3c776e62009-04-02 16:57:43 -07002144 pc = lookup_page_cgroup(page);
Daisuke Nishimurac0bd3f62009-04-30 15:08:11 -07002145 lock_page_cgroup(pc);
KAMEZAWA Hiroyukia3b2d692009-04-02 16:57:45 -07002146 if (PageCgroupUsed(pc)) {
Daisuke Nishimura3c776e62009-04-02 16:57:43 -07002147 mem = pc->mem_cgroup;
KAMEZAWA Hiroyukia3b2d692009-04-02 16:57:45 -07002148 if (mem && !css_tryget(&mem->css))
2149 mem = NULL;
Wu Fengguange42d9d52009-12-16 12:19:59 +01002150 } else if (PageSwapCache(page)) {
Daisuke Nishimura3c776e62009-04-02 16:57:43 -07002151 ent.val = page_private(page);
KAMEZAWA Hiroyukia3b2d692009-04-02 16:57:45 -07002152 id = lookup_swap_cgroup(ent);
2153 rcu_read_lock();
2154 mem = mem_cgroup_lookup(id);
2155 if (mem && !css_tryget(&mem->css))
2156 mem = NULL;
2157 rcu_read_unlock();
Daisuke Nishimura3c776e62009-04-02 16:57:43 -07002158 }
Daisuke Nishimurac0bd3f62009-04-30 15:08:11 -07002159 unlock_page_cgroup(pc);
KAMEZAWA Hiroyukib5a84312009-01-07 18:08:35 -08002160 return mem;
2161}
2162
KAMEZAWA Hiroyukica3e0212011-01-20 14:44:24 -08002163static void __mem_cgroup_commit_charge(struct mem_cgroup *mem,
Johannes Weiner5564e882011-03-23 16:42:29 -07002164 struct page *page,
Johannes Weiner7ec99d62011-03-23 16:42:36 -07002165 unsigned int nr_pages,
KAMEZAWA Hiroyukica3e0212011-01-20 14:44:24 -08002166 struct page_cgroup *pc,
Johannes Weiner7ec99d62011-03-23 16:42:36 -07002167 enum charge_type ctype)
KAMEZAWA Hiroyuki7a81b882009-01-07 18:07:48 -08002168{
KAMEZAWA Hiroyukica3e0212011-01-20 14:44:24 -08002169 lock_page_cgroup(pc);
2170 if (unlikely(PageCgroupUsed(pc))) {
2171 unlock_page_cgroup(pc);
Johannes Weinere7018b8d2011-03-23 16:42:33 -07002172 __mem_cgroup_cancel_charge(mem, nr_pages);
KAMEZAWA Hiroyukica3e0212011-01-20 14:44:24 -08002173 return;
2174 }
2175 /*
2176 * we don't need page_cgroup_lock about tail pages, becase they are not
2177 * accessed by any other context at this point.
2178 */
Balbir Singh8a9f3cc2008-02-07 00:13:53 -08002179 pc->mem_cgroup = mem;
KAMEZAWA Hiroyuki261fb612009-09-23 15:56:33 -07002180 /*
2181 * We access a page_cgroup asynchronously without lock_page_cgroup().
2182 * Especially when a page_cgroup is taken from a page, pc->mem_cgroup
2183 * is accessed after testing USED bit. To make pc->mem_cgroup visible
2184 * before USED bit, we need memory barrier here.
2185 * See mem_cgroup_add_lru_list(), etc.
2186 */
KAMEZAWA Hiroyuki08e552c2009-01-07 18:08:01 -08002187 smp_wmb();
Balbir Singh4b3bde42009-09-23 15:56:32 -07002188 switch (ctype) {
2189 case MEM_CGROUP_CHARGE_TYPE_CACHE:
2190 case MEM_CGROUP_CHARGE_TYPE_SHMEM:
2191 SetPageCgroupCache(pc);
2192 SetPageCgroupUsed(pc);
2193 break;
2194 case MEM_CGROUP_CHARGE_TYPE_MAPPED:
2195 ClearPageCgroupCache(pc);
2196 SetPageCgroupUsed(pc);
2197 break;
2198 default:
2199 break;
2200 }
Hugh Dickins3be91272008-02-07 00:14:19 -08002201
KAMEZAWA Hiroyukica3e0212011-01-20 14:44:24 -08002202 mem_cgroup_charge_statistics(mem, PageCgroupCache(pc), nr_pages);
KAMEZAWA Hiroyuki52d4b9a2008-10-18 20:28:16 -07002203 unlock_page_cgroup(pc);
KAMEZAWA Hiroyuki430e48632010-03-10 15:22:30 -08002204 /*
2205 * "charge_statistics" updated event counter. Then, check it.
2206 * Insert ancestor (and ancestor's ancestors), to softlimit RB-tree.
2207 * if they exceeds softlimit.
2208 */
Johannes Weiner5564e882011-03-23 16:42:29 -07002209 memcg_check_events(mem, page);
Balbir Singh8a9f3cc2008-02-07 00:13:53 -08002210}
2211
KAMEZAWA Hiroyukica3e0212011-01-20 14:44:24 -08002212#ifdef CONFIG_TRANSPARENT_HUGEPAGE
2213
2214#define PCGF_NOCOPY_AT_SPLIT ((1 << PCG_LOCK) | (1 << PCG_MOVE_LOCK) |\
2215 (1 << PCG_ACCT_LRU) | (1 << PCG_MIGRATION))
2216/*
2217 * Because tail pages are not marked as "used", set it. We're under
2218 * zone->lru_lock, 'splitting on pmd' and compund_lock.
2219 */
2220void mem_cgroup_split_huge_fixup(struct page *head, struct page *tail)
2221{
2222 struct page_cgroup *head_pc = lookup_page_cgroup(head);
2223 struct page_cgroup *tail_pc = lookup_page_cgroup(tail);
2224 unsigned long flags;
2225
KAMEZAWA Hiroyuki3d37c4a2011-01-25 15:07:28 -08002226 if (mem_cgroup_disabled())
2227 return;
KAMEZAWA Hiroyukica3e0212011-01-20 14:44:24 -08002228 /*
KAMEZAWA Hiroyukiece35ca2011-01-20 14:44:24 -08002229 * We have no races with charge/uncharge but will have races with
KAMEZAWA Hiroyukica3e0212011-01-20 14:44:24 -08002230 * page state accounting.
2231 */
2232 move_lock_page_cgroup(head_pc, &flags);
2233
2234 tail_pc->mem_cgroup = head_pc->mem_cgroup;
2235 smp_wmb(); /* see __commit_charge() */
KAMEZAWA Hiroyukiece35ca2011-01-20 14:44:24 -08002236 if (PageCgroupAcctLRU(head_pc)) {
2237 enum lru_list lru;
2238 struct mem_cgroup_per_zone *mz;
2239
2240 /*
2241 * LRU flags cannot be copied because we need to add tail
2242 *.page to LRU by generic call and our hook will be called.
2243 * We hold lru_lock, then, reduce counter directly.
2244 */
2245 lru = page_lru(head);
Johannes Weiner97a6c372011-03-23 16:42:27 -07002246 mz = page_cgroup_zoneinfo(head_pc->mem_cgroup, head);
KAMEZAWA Hiroyukiece35ca2011-01-20 14:44:24 -08002247 MEM_CGROUP_ZSTAT(mz, lru) -= 1;
2248 }
KAMEZAWA Hiroyukica3e0212011-01-20 14:44:24 -08002249 tail_pc->flags = head_pc->flags & ~PCGF_NOCOPY_AT_SPLIT;
2250 move_unlock_page_cgroup(head_pc, &flags);
2251}
2252#endif
2253
KAMEZAWA Hiroyukif817ed42009-01-07 18:07:53 -08002254/**
Johannes Weinerde3638d2011-03-23 16:42:28 -07002255 * mem_cgroup_move_account - move account of the page
Johannes Weiner5564e882011-03-23 16:42:29 -07002256 * @page: the page
Johannes Weiner7ec99d62011-03-23 16:42:36 -07002257 * @nr_pages: number of regular pages (>1 for huge pages)
KAMEZAWA Hiroyukif817ed42009-01-07 18:07:53 -08002258 * @pc: page_cgroup of the page.
2259 * @from: mem_cgroup which the page is moved from.
2260 * @to: mem_cgroup which the page is moved to. @from != @to.
Daisuke Nishimura854ffa82010-03-10 15:22:15 -08002261 * @uncharge: whether we should call uncharge and css_put against @from.
KAMEZAWA Hiroyukif817ed42009-01-07 18:07:53 -08002262 *
2263 * The caller must confirm following.
KAMEZAWA Hiroyuki08e552c2009-01-07 18:08:01 -08002264 * - page is not on LRU (isolate_page() is useful.)
Johannes Weiner7ec99d62011-03-23 16:42:36 -07002265 * - compound_lock is held when nr_pages > 1
KAMEZAWA Hiroyukif817ed42009-01-07 18:07:53 -08002266 *
Daisuke Nishimura854ffa82010-03-10 15:22:15 -08002267 * This function doesn't do "charge" nor css_get to new cgroup. It should be
Lucas De Marchi25985ed2011-03-30 22:57:33 -03002268 * done by a caller(__mem_cgroup_try_charge would be useful). If @uncharge is
Daisuke Nishimura854ffa82010-03-10 15:22:15 -08002269 * true, this function does "uncharge" from old cgroup, but it doesn't if
2270 * @uncharge is false, so a caller should do "uncharge".
KAMEZAWA Hiroyukif817ed42009-01-07 18:07:53 -08002271 */
Johannes Weiner7ec99d62011-03-23 16:42:36 -07002272static int mem_cgroup_move_account(struct page *page,
2273 unsigned int nr_pages,
2274 struct page_cgroup *pc,
2275 struct mem_cgroup *from,
2276 struct mem_cgroup *to,
2277 bool uncharge)
KAMEZAWA Hiroyukif817ed42009-01-07 18:07:53 -08002278{
Johannes Weinerde3638d2011-03-23 16:42:28 -07002279 unsigned long flags;
2280 int ret;
KAMEZAWA Hiroyuki987eba62011-01-20 14:44:25 -08002281
KAMEZAWA Hiroyukif817ed42009-01-07 18:07:53 -08002282 VM_BUG_ON(from == to);
Johannes Weiner5564e882011-03-23 16:42:29 -07002283 VM_BUG_ON(PageLRU(page));
Johannes Weinerde3638d2011-03-23 16:42:28 -07002284 /*
2285 * The page is isolated from LRU. So, collapse function
2286 * will not handle this page. But page splitting can happen.
2287 * Do this check under compound_page_lock(). The caller should
2288 * hold it.
2289 */
2290 ret = -EBUSY;
Johannes Weiner7ec99d62011-03-23 16:42:36 -07002291 if (nr_pages > 1 && !PageTransHuge(page))
Johannes Weinerde3638d2011-03-23 16:42:28 -07002292 goto out;
2293
2294 lock_page_cgroup(pc);
2295
2296 ret = -EINVAL;
2297 if (!PageCgroupUsed(pc) || pc->mem_cgroup != from)
2298 goto unlock;
2299
2300 move_lock_page_cgroup(pc, &flags);
KAMEZAWA Hiroyukif817ed42009-01-07 18:07:53 -08002301
KAMEZAWA Hiroyuki8725d542010-04-06 14:35:05 -07002302 if (PageCgroupFileMapped(pc)) {
KAMEZAWA Hiroyukic62b1a32010-03-10 15:22:29 -08002303 /* Update mapped_file data for mem_cgroup */
2304 preempt_disable();
2305 __this_cpu_dec(from->stat->count[MEM_CGROUP_STAT_FILE_MAPPED]);
2306 __this_cpu_inc(to->stat->count[MEM_CGROUP_STAT_FILE_MAPPED]);
2307 preempt_enable();
Balbir Singhd69b0422009-06-17 16:26:34 -07002308 }
KAMEZAWA Hiroyuki987eba62011-01-20 14:44:25 -08002309 mem_cgroup_charge_statistics(from, PageCgroupCache(pc), -nr_pages);
Daisuke Nishimura854ffa82010-03-10 15:22:15 -08002310 if (uncharge)
2311 /* This is not "cancel", but cancel_charge does all we need. */
Johannes Weinere7018b8d2011-03-23 16:42:33 -07002312 __mem_cgroup_cancel_charge(from, nr_pages);
Balbir Singhd69b0422009-06-17 16:26:34 -07002313
Daisuke Nishimura854ffa82010-03-10 15:22:15 -08002314 /* caller should have done css_get */
KAMEZAWA Hiroyuki08e552c2009-01-07 18:08:01 -08002315 pc->mem_cgroup = to;
KAMEZAWA Hiroyuki987eba62011-01-20 14:44:25 -08002316 mem_cgroup_charge_statistics(to, PageCgroupCache(pc), nr_pages);
KAMEZAWA Hiroyuki88703262009-07-29 15:04:06 -07002317 /*
2318 * We charges against "to" which may not have any tasks. Then, "to"
2319 * can be under rmdir(). But in current implementation, caller of
Daisuke Nishimura4ffef5f2010-03-10 15:22:14 -08002320 * this function is just force_empty() and move charge, so it's
Lucas De Marchi25985ed2011-03-30 22:57:33 -03002321 * guaranteed that "to" is never removed. So, we don't check rmdir
Daisuke Nishimura4ffef5f2010-03-10 15:22:14 -08002322 * status here.
KAMEZAWA Hiroyuki88703262009-07-29 15:04:06 -07002323 */
Johannes Weinerde3638d2011-03-23 16:42:28 -07002324 move_unlock_page_cgroup(pc, &flags);
2325 ret = 0;
2326unlock:
Daisuke Nishimura57f9fd7d2009-12-15 16:47:11 -08002327 unlock_page_cgroup(pc);
KAMEZAWA Hiroyukid2265e62010-03-10 15:22:31 -08002328 /*
2329 * check events
2330 */
Johannes Weiner5564e882011-03-23 16:42:29 -07002331 memcg_check_events(to, page);
2332 memcg_check_events(from, page);
Johannes Weinerde3638d2011-03-23 16:42:28 -07002333out:
KAMEZAWA Hiroyukif817ed42009-01-07 18:07:53 -08002334 return ret;
2335}
2336
2337/*
2338 * move charges to its parent.
2339 */
2340
Johannes Weiner5564e882011-03-23 16:42:29 -07002341static int mem_cgroup_move_parent(struct page *page,
2342 struct page_cgroup *pc,
KAMEZAWA Hiroyukif817ed42009-01-07 18:07:53 -08002343 struct mem_cgroup *child,
2344 gfp_t gfp_mask)
2345{
2346 struct cgroup *cg = child->css.cgroup;
2347 struct cgroup *pcg = cg->parent;
2348 struct mem_cgroup *parent;
Johannes Weiner7ec99d62011-03-23 16:42:36 -07002349 unsigned int nr_pages;
Andrew Morton4be44892011-03-23 16:42:39 -07002350 unsigned long uninitialized_var(flags);
KAMEZAWA Hiroyukif817ed42009-01-07 18:07:53 -08002351 int ret;
2352
2353 /* Is ROOT ? */
2354 if (!pcg)
2355 return -EINVAL;
2356
Daisuke Nishimura57f9fd7d2009-12-15 16:47:11 -08002357 ret = -EBUSY;
2358 if (!get_page_unless_zero(page))
2359 goto out;
2360 if (isolate_lru_page(page))
2361 goto put;
KAMEZAWA Hiroyuki52dbb902011-01-25 15:07:29 -08002362
Johannes Weiner7ec99d62011-03-23 16:42:36 -07002363 nr_pages = hpage_nr_pages(page);
KAMEZAWA Hiroyuki08e552c2009-01-07 18:08:01 -08002364
KAMEZAWA Hiroyukif817ed42009-01-07 18:07:53 -08002365 parent = mem_cgroup_from_cont(pcg);
Johannes Weiner7ec99d62011-03-23 16:42:36 -07002366 ret = __mem_cgroup_try_charge(NULL, gfp_mask, nr_pages, &parent, false);
KAMEZAWA Hiroyukia636b322009-01-07 18:08:08 -08002367 if (ret || !parent)
Daisuke Nishimura57f9fd7d2009-12-15 16:47:11 -08002368 goto put_back;
KAMEZAWA Hiroyuki08e552c2009-01-07 18:08:01 -08002369
Johannes Weiner7ec99d62011-03-23 16:42:36 -07002370 if (nr_pages > 1)
KAMEZAWA Hiroyuki987eba62011-01-20 14:44:25 -08002371 flags = compound_lock_irqsave(page);
2372
Johannes Weiner7ec99d62011-03-23 16:42:36 -07002373 ret = mem_cgroup_move_account(page, nr_pages, pc, child, parent, true);
Daisuke Nishimura854ffa82010-03-10 15:22:15 -08002374 if (ret)
Johannes Weiner7ec99d62011-03-23 16:42:36 -07002375 __mem_cgroup_cancel_charge(parent, nr_pages);
Jesper Juhl8dba4742011-01-25 15:07:24 -08002376
Johannes Weiner7ec99d62011-03-23 16:42:36 -07002377 if (nr_pages > 1)
KAMEZAWA Hiroyuki987eba62011-01-20 14:44:25 -08002378 compound_unlock_irqrestore(page, flags);
Jesper Juhl8dba4742011-01-25 15:07:24 -08002379put_back:
KAMEZAWA Hiroyuki08e552c2009-01-07 18:08:01 -08002380 putback_lru_page(page);
Daisuke Nishimura57f9fd7d2009-12-15 16:47:11 -08002381put:
Daisuke Nishimura40d58132009-01-15 13:51:12 -08002382 put_page(page);
Daisuke Nishimura57f9fd7d2009-12-15 16:47:11 -08002383out:
KAMEZAWA Hiroyukif817ed42009-01-07 18:07:53 -08002384 return ret;
2385}
2386
KAMEZAWA Hiroyuki7a81b882009-01-07 18:07:48 -08002387/*
2388 * Charge the memory controller for page usage.
2389 * Return
2390 * 0 if the charge was successful
2391 * < 0 if the cgroup is over its limit
2392 */
2393static int mem_cgroup_charge_common(struct page *page, struct mm_struct *mm,
Daisuke Nishimura73045c42010-08-10 18:02:59 -07002394 gfp_t gfp_mask, enum charge_type ctype)
KAMEZAWA Hiroyuki7a81b882009-01-07 18:07:48 -08002395{
Daisuke Nishimura73045c42010-08-10 18:02:59 -07002396 struct mem_cgroup *mem = NULL;
Johannes Weiner7ec99d62011-03-23 16:42:36 -07002397 unsigned int nr_pages = 1;
Johannes Weiner8493ae42011-02-01 15:52:44 -08002398 struct page_cgroup *pc;
2399 bool oom = true;
2400 int ret;
Andrea Arcangeliec168512011-01-13 15:46:56 -08002401
Andrea Arcangeli37c2ac72011-01-13 15:47:16 -08002402 if (PageTransHuge(page)) {
Johannes Weiner7ec99d62011-03-23 16:42:36 -07002403 nr_pages <<= compound_order(page);
Andrea Arcangeli37c2ac72011-01-13 15:47:16 -08002404 VM_BUG_ON(!PageTransHuge(page));
Johannes Weiner8493ae42011-02-01 15:52:44 -08002405 /*
2406 * Never OOM-kill a process for a huge page. The
2407 * fault handler will fall back to regular pages.
2408 */
2409 oom = false;
Andrea Arcangeli37c2ac72011-01-13 15:47:16 -08002410 }
KAMEZAWA Hiroyuki7a81b882009-01-07 18:07:48 -08002411
2412 pc = lookup_page_cgroup(page);
Johannes Weineraf4a6622011-03-23 16:42:24 -07002413 BUG_ON(!pc); /* XXX: remove this and move pc lookup into commit */
KAMEZAWA Hiroyuki7a81b882009-01-07 18:07:48 -08002414
Johannes Weiner7ec99d62011-03-23 16:42:36 -07002415 ret = __mem_cgroup_try_charge(mm, gfp_mask, nr_pages, &mem, oom);
KAMEZAWA Hiroyukia636b322009-01-07 18:08:08 -08002416 if (ret || !mem)
KAMEZAWA Hiroyuki7a81b882009-01-07 18:07:48 -08002417 return ret;
2418
Johannes Weiner7ec99d62011-03-23 16:42:36 -07002419 __mem_cgroup_commit_charge(mem, page, nr_pages, pc, ctype);
KAMEZAWA Hiroyuki7a81b882009-01-07 18:07:48 -08002420 return 0;
2421}
2422
2423int mem_cgroup_newpage_charge(struct page *page,
2424 struct mm_struct *mm, gfp_t gfp_mask)
KAMEZAWA Hiroyuki217bc312008-02-07 00:14:17 -08002425{
Hirokazu Takahashif8d665422009-01-07 18:08:02 -08002426 if (mem_cgroup_disabled())
Li Zefancede86a2008-07-25 01:47:18 -07002427 return 0;
KAMEZAWA Hiroyuki69029cd2008-07-25 01:47:14 -07002428 /*
2429 * If already mapped, we don't have to account.
2430 * If page cache, page->mapping has address_space.
2431 * But page->mapping may have out-of-use anon_vma pointer,
2432 * detecit it by PageAnon() check. newly-mapped-anon's page->mapping
2433 * is NULL.
2434 */
2435 if (page_mapped(page) || (page->mapping && !PageAnon(page)))
2436 return 0;
2437 if (unlikely(!mm))
2438 mm = &init_mm;
KAMEZAWA Hiroyuki217bc312008-02-07 00:14:17 -08002439 return mem_cgroup_charge_common(page, mm, gfp_mask,
Daisuke Nishimura73045c42010-08-10 18:02:59 -07002440 MEM_CGROUP_CHARGE_TYPE_MAPPED);
KAMEZAWA Hiroyuki217bc312008-02-07 00:14:17 -08002441}
2442
Daisuke Nishimura83aae4c2009-04-02 16:57:48 -07002443static void
2444__mem_cgroup_commit_charge_swapin(struct page *page, struct mem_cgroup *ptr,
2445 enum charge_type ctype);
2446
KAMEZAWA Hiroyuki5a6475a2011-03-23 16:42:42 -07002447static void
2448__mem_cgroup_commit_charge_lrucare(struct page *page, struct mem_cgroup *mem,
2449 enum charge_type ctype)
2450{
2451 struct page_cgroup *pc = lookup_page_cgroup(page);
2452 /*
2453 * In some case, SwapCache, FUSE(splice_buf->radixtree), the page
2454 * is already on LRU. It means the page may on some other page_cgroup's
2455 * LRU. Take care of it.
2456 */
2457 mem_cgroup_lru_del_before_commit(page);
2458 __mem_cgroup_commit_charge(mem, page, 1, pc, ctype);
2459 mem_cgroup_lru_add_after_commit(page);
2460 return;
2461}
2462
Balbir Singhe1a1cd52008-02-07 00:14:02 -08002463int mem_cgroup_cache_charge(struct page *page, struct mm_struct *mm,
2464 gfp_t gfp_mask)
Balbir Singh8697d332008-02-07 00:13:59 -08002465{
KAMEZAWA Hiroyuki5a6475a2011-03-23 16:42:42 -07002466 struct mem_cgroup *mem = NULL;
KAMEZAWA Hiroyukib5a84312009-01-07 18:08:35 -08002467 int ret;
2468
Hirokazu Takahashif8d665422009-01-07 18:08:02 -08002469 if (mem_cgroup_disabled())
Li Zefancede86a2008-07-25 01:47:18 -07002470 return 0;
KAMEZAWA Hiroyuki52d4b9a2008-10-18 20:28:16 -07002471 if (PageCompound(page))
2472 return 0;
KAMEZAWA Hiroyukiaccf1632008-07-25 01:47:17 -07002473 /*
2474 * Corner case handling. This is called from add_to_page_cache()
2475 * in usual. But some FS (shmem) precharges this page before calling it
2476 * and call add_to_page_cache() with GFP_NOWAIT.
2477 *
2478 * For GFP_NOWAIT case, the page may be pre-charged before calling
2479 * add_to_page_cache(). (See shmem.c) check it here and avoid to call
2480 * charge twice. (It works but has to pay a bit larger cost.)
KAMEZAWA Hiroyukib5a84312009-01-07 18:08:35 -08002481 * And when the page is SwapCache, it should take swap information
2482 * into account. This is under lock_page() now.
KAMEZAWA Hiroyukiaccf1632008-07-25 01:47:17 -07002483 */
2484 if (!(gfp_mask & __GFP_WAIT)) {
2485 struct page_cgroup *pc;
2486
KAMEZAWA Hiroyuki52d4b9a2008-10-18 20:28:16 -07002487 pc = lookup_page_cgroup(page);
2488 if (!pc)
2489 return 0;
2490 lock_page_cgroup(pc);
2491 if (PageCgroupUsed(pc)) {
2492 unlock_page_cgroup(pc);
KAMEZAWA Hiroyukiaccf1632008-07-25 01:47:17 -07002493 return 0;
2494 }
KAMEZAWA Hiroyuki52d4b9a2008-10-18 20:28:16 -07002495 unlock_page_cgroup(pc);
KAMEZAWA Hiroyukiaccf1632008-07-25 01:47:17 -07002496 }
2497
Daisuke Nishimura73045c42010-08-10 18:02:59 -07002498 if (unlikely(!mm))
Balbir Singh8697d332008-02-07 00:13:59 -08002499 mm = &init_mm;
KAMEZAWA Hiroyukiaccf1632008-07-25 01:47:17 -07002500
KAMEZAWA Hiroyuki5a6475a2011-03-23 16:42:42 -07002501 if (page_is_file_cache(page)) {
2502 ret = __mem_cgroup_try_charge(mm, gfp_mask, 1, &mem, true);
2503 if (ret || !mem)
2504 return ret;
KAMEZAWA Hiroyukib5a84312009-01-07 18:08:35 -08002505
KAMEZAWA Hiroyuki5a6475a2011-03-23 16:42:42 -07002506 /*
2507 * FUSE reuses pages without going through the final
2508 * put that would remove them from the LRU list, make
2509 * sure that they get relinked properly.
2510 */
2511 __mem_cgroup_commit_charge_lrucare(page, mem,
2512 MEM_CGROUP_CHARGE_TYPE_CACHE);
2513 return ret;
2514 }
Daisuke Nishimura83aae4c2009-04-02 16:57:48 -07002515 /* shmem */
2516 if (PageSwapCache(page)) {
2517 ret = mem_cgroup_try_charge_swapin(mm, page, gfp_mask, &mem);
2518 if (!ret)
2519 __mem_cgroup_commit_charge_swapin(page, mem,
2520 MEM_CGROUP_CHARGE_TYPE_SHMEM);
2521 } else
2522 ret = mem_cgroup_charge_common(page, mm, gfp_mask,
Daisuke Nishimura73045c42010-08-10 18:02:59 -07002523 MEM_CGROUP_CHARGE_TYPE_SHMEM);
KAMEZAWA Hiroyukib5a84312009-01-07 18:08:35 -08002524
KAMEZAWA Hiroyukib5a84312009-01-07 18:08:35 -08002525 return ret;
KAMEZAWA Hiroyukie8589cc2008-07-25 01:47:10 -07002526}
2527
KAMEZAWA Hiroyuki54595fe2009-01-07 18:08:33 -08002528/*
2529 * While swap-in, try_charge -> commit or cancel, the page is locked.
2530 * And when try_charge() successfully returns, one refcnt to memcg without
Uwe Kleine-König21ae2952009-10-07 15:21:09 +02002531 * struct page_cgroup is acquired. This refcnt will be consumed by
KAMEZAWA Hiroyuki54595fe2009-01-07 18:08:33 -08002532 * "commit()" or removed by "cancel()"
2533 */
KAMEZAWA Hiroyuki8c7c6e342009-01-07 18:08:00 -08002534int mem_cgroup_try_charge_swapin(struct mm_struct *mm,
2535 struct page *page,
2536 gfp_t mask, struct mem_cgroup **ptr)
2537{
2538 struct mem_cgroup *mem;
KAMEZAWA Hiroyuki54595fe2009-01-07 18:08:33 -08002539 int ret;
KAMEZAWA Hiroyuki8c7c6e342009-01-07 18:08:00 -08002540
KAMEZAWA Hiroyuki56039ef2011-03-23 16:42:19 -07002541 *ptr = NULL;
2542
Hirokazu Takahashif8d665422009-01-07 18:08:02 -08002543 if (mem_cgroup_disabled())
KAMEZAWA Hiroyuki8c7c6e342009-01-07 18:08:00 -08002544 return 0;
2545
2546 if (!do_swap_account)
2547 goto charge_cur_mm;
KAMEZAWA Hiroyuki8c7c6e342009-01-07 18:08:00 -08002548 /*
2549 * A racing thread's fault, or swapoff, may have already updated
Hugh Dickins407f9c82009-12-14 17:59:30 -08002550 * the pte, and even removed page from swap cache: in those cases
2551 * do_swap_page()'s pte_same() test will fail; but there's also a
2552 * KSM case which does need to charge the page.
KAMEZAWA Hiroyuki8c7c6e342009-01-07 18:08:00 -08002553 */
2554 if (!PageSwapCache(page))
Hugh Dickins407f9c82009-12-14 17:59:30 -08002555 goto charge_cur_mm;
Wu Fengguange42d9d52009-12-16 12:19:59 +01002556 mem = try_get_mem_cgroup_from_page(page);
KAMEZAWA Hiroyuki54595fe2009-01-07 18:08:33 -08002557 if (!mem)
2558 goto charge_cur_mm;
KAMEZAWA Hiroyuki8c7c6e342009-01-07 18:08:00 -08002559 *ptr = mem;
Johannes Weiner7ec99d62011-03-23 16:42:36 -07002560 ret = __mem_cgroup_try_charge(NULL, mask, 1, ptr, true);
KAMEZAWA Hiroyuki54595fe2009-01-07 18:08:33 -08002561 css_put(&mem->css);
2562 return ret;
KAMEZAWA Hiroyuki8c7c6e342009-01-07 18:08:00 -08002563charge_cur_mm:
2564 if (unlikely(!mm))
2565 mm = &init_mm;
Johannes Weiner7ec99d62011-03-23 16:42:36 -07002566 return __mem_cgroup_try_charge(mm, mask, 1, ptr, true);
KAMEZAWA Hiroyuki8c7c6e342009-01-07 18:08:00 -08002567}
2568
Daisuke Nishimura83aae4c2009-04-02 16:57:48 -07002569static void
2570__mem_cgroup_commit_charge_swapin(struct page *page, struct mem_cgroup *ptr,
2571 enum charge_type ctype)
KAMEZAWA Hiroyuki7a81b882009-01-07 18:07:48 -08002572{
Hirokazu Takahashif8d665422009-01-07 18:08:02 -08002573 if (mem_cgroup_disabled())
KAMEZAWA Hiroyuki7a81b882009-01-07 18:07:48 -08002574 return;
2575 if (!ptr)
2576 return;
KAMEZAWA Hiroyuki88703262009-07-29 15:04:06 -07002577 cgroup_exclude_rmdir(&ptr->css);
KAMEZAWA Hiroyuki5a6475a2011-03-23 16:42:42 -07002578
2579 __mem_cgroup_commit_charge_lrucare(page, ptr, ctype);
KAMEZAWA Hiroyuki8c7c6e342009-01-07 18:08:00 -08002580 /*
2581 * Now swap is on-memory. This means this page may be
2582 * counted both as mem and swap....double count.
KAMEZAWA Hiroyuki03f3c432009-01-07 18:08:31 -08002583 * Fix it by uncharging from memsw. Basically, this SwapCache is stable
2584 * under lock_page(). But in do_swap_page()::memory.c, reuse_swap_page()
2585 * may call delete_from_swap_cache() before reach here.
KAMEZAWA Hiroyuki8c7c6e342009-01-07 18:08:00 -08002586 */
KAMEZAWA Hiroyuki03f3c432009-01-07 18:08:31 -08002587 if (do_swap_account && PageSwapCache(page)) {
KAMEZAWA Hiroyuki8c7c6e342009-01-07 18:08:00 -08002588 swp_entry_t ent = {.val = page_private(page)};
KAMEZAWA Hiroyukia3b2d692009-04-02 16:57:45 -07002589 unsigned short id;
KAMEZAWA Hiroyuki8c7c6e342009-01-07 18:08:00 -08002590 struct mem_cgroup *memcg;
KAMEZAWA Hiroyukia3b2d692009-04-02 16:57:45 -07002591
2592 id = swap_cgroup_record(ent, 0);
2593 rcu_read_lock();
2594 memcg = mem_cgroup_lookup(id);
KAMEZAWA Hiroyuki8c7c6e342009-01-07 18:08:00 -08002595 if (memcg) {
KAMEZAWA Hiroyukia3b2d692009-04-02 16:57:45 -07002596 /*
2597 * This recorded memcg can be obsolete one. So, avoid
2598 * calling css_tryget
2599 */
Balbir Singh0c3e73e2009-09-23 15:56:42 -07002600 if (!mem_cgroup_is_root(memcg))
KAMEZAWA Hiroyuki4e649152009-10-01 15:44:11 -07002601 res_counter_uncharge(&memcg->memsw, PAGE_SIZE);
Balbir Singh0c3e73e2009-09-23 15:56:42 -07002602 mem_cgroup_swap_statistics(memcg, false);
KAMEZAWA Hiroyuki8c7c6e342009-01-07 18:08:00 -08002603 mem_cgroup_put(memcg);
2604 }
KAMEZAWA Hiroyukia3b2d692009-04-02 16:57:45 -07002605 rcu_read_unlock();
KAMEZAWA Hiroyuki8c7c6e342009-01-07 18:08:00 -08002606 }
KAMEZAWA Hiroyuki88703262009-07-29 15:04:06 -07002607 /*
2608 * At swapin, we may charge account against cgroup which has no tasks.
2609 * So, rmdir()->pre_destroy() can be called while we do this charge.
2610 * In that case, we need to call pre_destroy() again. check it here.
2611 */
2612 cgroup_release_and_wakeup_rmdir(&ptr->css);
KAMEZAWA Hiroyuki7a81b882009-01-07 18:07:48 -08002613}
2614
Daisuke Nishimura83aae4c2009-04-02 16:57:48 -07002615void mem_cgroup_commit_charge_swapin(struct page *page, struct mem_cgroup *ptr)
2616{
2617 __mem_cgroup_commit_charge_swapin(page, ptr,
2618 MEM_CGROUP_CHARGE_TYPE_MAPPED);
2619}
2620
KAMEZAWA Hiroyuki7a81b882009-01-07 18:07:48 -08002621void mem_cgroup_cancel_charge_swapin(struct mem_cgroup *mem)
2622{
Hirokazu Takahashif8d665422009-01-07 18:08:02 -08002623 if (mem_cgroup_disabled())
KAMEZAWA Hiroyuki7a81b882009-01-07 18:07:48 -08002624 return;
2625 if (!mem)
2626 return;
Johannes Weinere7018b8d2011-03-23 16:42:33 -07002627 __mem_cgroup_cancel_charge(mem, 1);
KAMEZAWA Hiroyuki7a81b882009-01-07 18:07:48 -08002628}
2629
Johannes Weiner7ec99d62011-03-23 16:42:36 -07002630static void mem_cgroup_do_uncharge(struct mem_cgroup *mem,
2631 unsigned int nr_pages,
2632 const enum charge_type ctype)
KAMEZAWA Hiroyuki569b8462009-12-15 16:47:03 -08002633{
2634 struct memcg_batch_info *batch = NULL;
2635 bool uncharge_memsw = true;
Johannes Weiner7ec99d62011-03-23 16:42:36 -07002636
KAMEZAWA Hiroyuki569b8462009-12-15 16:47:03 -08002637 /* If swapout, usage of swap doesn't decrease */
2638 if (!do_swap_account || ctype == MEM_CGROUP_CHARGE_TYPE_SWAPOUT)
2639 uncharge_memsw = false;
KAMEZAWA Hiroyuki569b8462009-12-15 16:47:03 -08002640
2641 batch = &current->memcg_batch;
2642 /*
2643 * In usual, we do css_get() when we remember memcg pointer.
2644 * But in this case, we keep res->usage until end of a series of
2645 * uncharges. Then, it's ok to ignore memcg's refcnt.
2646 */
2647 if (!batch->memcg)
2648 batch->memcg = mem;
2649 /*
KAMEZAWA Hiroyuki3c11ecf2010-05-26 14:42:37 -07002650 * do_batch > 0 when unmapping pages or inode invalidate/truncate.
Lucas De Marchi25985ed2011-03-30 22:57:33 -03002651 * In those cases, all pages freed continuously can be expected to be in
KAMEZAWA Hiroyuki3c11ecf2010-05-26 14:42:37 -07002652 * the same cgroup and we have chance to coalesce uncharges.
2653 * But we do uncharge one by one if this is killed by OOM(TIF_MEMDIE)
2654 * because we want to do uncharge as soon as possible.
2655 */
2656
2657 if (!batch->do_batch || test_thread_flag(TIF_MEMDIE))
2658 goto direct_uncharge;
2659
Johannes Weiner7ec99d62011-03-23 16:42:36 -07002660 if (nr_pages > 1)
Andrea Arcangeliec168512011-01-13 15:46:56 -08002661 goto direct_uncharge;
2662
KAMEZAWA Hiroyuki3c11ecf2010-05-26 14:42:37 -07002663 /*
KAMEZAWA Hiroyuki569b8462009-12-15 16:47:03 -08002664 * In typical case, batch->memcg == mem. This means we can
2665 * merge a series of uncharges to an uncharge of res_counter.
2666 * If not, we uncharge res_counter ony by one.
2667 */
2668 if (batch->memcg != mem)
2669 goto direct_uncharge;
2670 /* remember freed charge and uncharge it later */
Johannes Weiner7ffd4ca2011-03-23 16:42:35 -07002671 batch->nr_pages++;
KAMEZAWA Hiroyuki569b8462009-12-15 16:47:03 -08002672 if (uncharge_memsw)
Johannes Weiner7ffd4ca2011-03-23 16:42:35 -07002673 batch->memsw_nr_pages++;
KAMEZAWA Hiroyuki569b8462009-12-15 16:47:03 -08002674 return;
2675direct_uncharge:
Johannes Weiner7ec99d62011-03-23 16:42:36 -07002676 res_counter_uncharge(&mem->res, nr_pages * PAGE_SIZE);
KAMEZAWA Hiroyuki569b8462009-12-15 16:47:03 -08002677 if (uncharge_memsw)
Johannes Weiner7ec99d62011-03-23 16:42:36 -07002678 res_counter_uncharge(&mem->memsw, nr_pages * PAGE_SIZE);
KAMEZAWA Hiroyuki3c11ecf2010-05-26 14:42:37 -07002679 if (unlikely(batch->memcg != mem))
2680 memcg_oom_recover(mem);
KAMEZAWA Hiroyuki569b8462009-12-15 16:47:03 -08002681 return;
2682}
KAMEZAWA Hiroyuki7a81b882009-01-07 18:07:48 -08002683
Balbir Singh8697d332008-02-07 00:13:59 -08002684/*
KAMEZAWA Hiroyuki69029cd2008-07-25 01:47:14 -07002685 * uncharge if !page_mapped(page)
Balbir Singh8a9f3cc2008-02-07 00:13:53 -08002686 */
KAMEZAWA Hiroyuki8c7c6e342009-01-07 18:08:00 -08002687static struct mem_cgroup *
KAMEZAWA Hiroyuki69029cd2008-07-25 01:47:14 -07002688__mem_cgroup_uncharge_common(struct page *page, enum charge_type ctype)
Balbir Singh8a9f3cc2008-02-07 00:13:53 -08002689{
KAMEZAWA Hiroyuki8c7c6e342009-01-07 18:08:00 -08002690 struct mem_cgroup *mem = NULL;
Johannes Weiner7ec99d62011-03-23 16:42:36 -07002691 unsigned int nr_pages = 1;
2692 struct page_cgroup *pc;
Balbir Singh8a9f3cc2008-02-07 00:13:53 -08002693
Hirokazu Takahashif8d665422009-01-07 18:08:02 -08002694 if (mem_cgroup_disabled())
KAMEZAWA Hiroyuki8c7c6e342009-01-07 18:08:00 -08002695 return NULL;
Balbir Singh40779602008-04-04 14:29:59 -07002696
KAMEZAWA Hiroyukid13d1442009-01-07 18:07:56 -08002697 if (PageSwapCache(page))
KAMEZAWA Hiroyuki8c7c6e342009-01-07 18:08:00 -08002698 return NULL;
KAMEZAWA Hiroyukid13d1442009-01-07 18:07:56 -08002699
Andrea Arcangeli37c2ac72011-01-13 15:47:16 -08002700 if (PageTransHuge(page)) {
Johannes Weiner7ec99d62011-03-23 16:42:36 -07002701 nr_pages <<= compound_order(page);
Andrea Arcangeli37c2ac72011-01-13 15:47:16 -08002702 VM_BUG_ON(!PageTransHuge(page));
2703 }
Balbir Singh8697d332008-02-07 00:13:59 -08002704 /*
Balbir Singh3c541e12008-02-07 00:14:41 -08002705 * Check if our page_cgroup is valid
Balbir Singh8697d332008-02-07 00:13:59 -08002706 */
KAMEZAWA Hiroyuki52d4b9a2008-10-18 20:28:16 -07002707 pc = lookup_page_cgroup(page);
2708 if (unlikely(!pc || !PageCgroupUsed(pc)))
KAMEZAWA Hiroyuki8c7c6e342009-01-07 18:08:00 -08002709 return NULL;
Balbir Singh8a9f3cc2008-02-07 00:13:53 -08002710
KAMEZAWA Hiroyuki52d4b9a2008-10-18 20:28:16 -07002711 lock_page_cgroup(pc);
KAMEZAWA Hiroyukid13d1442009-01-07 18:07:56 -08002712
KAMEZAWA Hiroyuki8c7c6e342009-01-07 18:08:00 -08002713 mem = pc->mem_cgroup;
2714
KAMEZAWA Hiroyukid13d1442009-01-07 18:07:56 -08002715 if (!PageCgroupUsed(pc))
2716 goto unlock_out;
2717
2718 switch (ctype) {
2719 case MEM_CGROUP_CHARGE_TYPE_MAPPED:
KAMEZAWA Hiroyuki8a9478c2009-06-17 16:27:17 -07002720 case MEM_CGROUP_CHARGE_TYPE_DROP:
akpm@linux-foundation.orgac39cf82010-05-26 14:42:46 -07002721 /* See mem_cgroup_prepare_migration() */
2722 if (page_mapped(page) || PageCgroupMigration(pc))
KAMEZAWA Hiroyukid13d1442009-01-07 18:07:56 -08002723 goto unlock_out;
2724 break;
2725 case MEM_CGROUP_CHARGE_TYPE_SWAPOUT:
2726 if (!PageAnon(page)) { /* Shared memory */
2727 if (page->mapping && !page_is_file_cache(page))
2728 goto unlock_out;
2729 } else if (page_mapped(page)) /* Anon */
2730 goto unlock_out;
2731 break;
2732 default:
2733 break;
KAMEZAWA Hiroyuki52d4b9a2008-10-18 20:28:16 -07002734 }
KAMEZAWA Hiroyukid13d1442009-01-07 18:07:56 -08002735
Johannes Weiner7ec99d62011-03-23 16:42:36 -07002736 mem_cgroup_charge_statistics(mem, PageCgroupCache(pc), -nr_pages);
KAMEZAWA Hiroyuki04046e12009-04-02 16:57:33 -07002737
KAMEZAWA Hiroyuki52d4b9a2008-10-18 20:28:16 -07002738 ClearPageCgroupUsed(pc);
KAMEZAWA Hiroyuki544122e2009-01-07 18:08:34 -08002739 /*
2740 * pc->mem_cgroup is not cleared here. It will be accessed when it's
2741 * freed from LRU. This is safe because uncharged page is expected not
2742 * to be reused (freed soon). Exception is SwapCache, it's handled by
2743 * special functions.
2744 */
Hugh Dickinsb9c565d2008-03-04 14:29:11 -08002745
KAMEZAWA Hiroyuki52d4b9a2008-10-18 20:28:16 -07002746 unlock_page_cgroup(pc);
KAMEZAWA Hiroyukif75ca962010-08-10 18:03:02 -07002747 /*
2748 * even after unlock, we have mem->res.usage here and this memcg
2749 * will never be freed.
2750 */
KAMEZAWA Hiroyukid2265e62010-03-10 15:22:31 -08002751 memcg_check_events(mem, page);
KAMEZAWA Hiroyukif75ca962010-08-10 18:03:02 -07002752 if (do_swap_account && ctype == MEM_CGROUP_CHARGE_TYPE_SWAPOUT) {
2753 mem_cgroup_swap_statistics(mem, true);
2754 mem_cgroup_get(mem);
2755 }
2756 if (!mem_cgroup_is_root(mem))
Johannes Weiner7ec99d62011-03-23 16:42:36 -07002757 mem_cgroup_do_uncharge(mem, nr_pages, ctype);
KAMEZAWA Hiroyuki6d12e2d2008-02-07 00:14:31 -08002758
KAMEZAWA Hiroyuki8c7c6e342009-01-07 18:08:00 -08002759 return mem;
KAMEZAWA Hiroyukid13d1442009-01-07 18:07:56 -08002760
2761unlock_out:
2762 unlock_page_cgroup(pc);
KAMEZAWA Hiroyuki8c7c6e342009-01-07 18:08:00 -08002763 return NULL;
Balbir Singh3c541e12008-02-07 00:14:41 -08002764}
2765
KAMEZAWA Hiroyuki69029cd2008-07-25 01:47:14 -07002766void mem_cgroup_uncharge_page(struct page *page)
2767{
KAMEZAWA Hiroyuki52d4b9a2008-10-18 20:28:16 -07002768 /* early check. */
2769 if (page_mapped(page))
2770 return;
2771 if (page->mapping && !PageAnon(page))
2772 return;
KAMEZAWA Hiroyuki69029cd2008-07-25 01:47:14 -07002773 __mem_cgroup_uncharge_common(page, MEM_CGROUP_CHARGE_TYPE_MAPPED);
2774}
2775
2776void mem_cgroup_uncharge_cache_page(struct page *page)
2777{
2778 VM_BUG_ON(page_mapped(page));
KAMEZAWA Hiroyukib7abea92008-10-18 20:28:09 -07002779 VM_BUG_ON(page->mapping);
KAMEZAWA Hiroyuki69029cd2008-07-25 01:47:14 -07002780 __mem_cgroup_uncharge_common(page, MEM_CGROUP_CHARGE_TYPE_CACHE);
2781}
2782
KAMEZAWA Hiroyuki569b8462009-12-15 16:47:03 -08002783/*
2784 * Batch_start/batch_end is called in unmap_page_range/invlidate/trucate.
2785 * In that cases, pages are freed continuously and we can expect pages
2786 * are in the same memcg. All these calls itself limits the number of
2787 * pages freed at once, then uncharge_start/end() is called properly.
2788 * This may be called prural(2) times in a context,
2789 */
2790
2791void mem_cgroup_uncharge_start(void)
2792{
2793 current->memcg_batch.do_batch++;
2794 /* We can do nest. */
2795 if (current->memcg_batch.do_batch == 1) {
2796 current->memcg_batch.memcg = NULL;
Johannes Weiner7ffd4ca2011-03-23 16:42:35 -07002797 current->memcg_batch.nr_pages = 0;
2798 current->memcg_batch.memsw_nr_pages = 0;
KAMEZAWA Hiroyuki569b8462009-12-15 16:47:03 -08002799 }
2800}
2801
2802void mem_cgroup_uncharge_end(void)
2803{
2804 struct memcg_batch_info *batch = &current->memcg_batch;
2805
2806 if (!batch->do_batch)
2807 return;
2808
2809 batch->do_batch--;
2810 if (batch->do_batch) /* If stacked, do nothing. */
2811 return;
2812
2813 if (!batch->memcg)
2814 return;
2815 /*
2816 * This "batch->memcg" is valid without any css_get/put etc...
2817 * bacause we hide charges behind us.
2818 */
Johannes Weiner7ffd4ca2011-03-23 16:42:35 -07002819 if (batch->nr_pages)
2820 res_counter_uncharge(&batch->memcg->res,
2821 batch->nr_pages * PAGE_SIZE);
2822 if (batch->memsw_nr_pages)
2823 res_counter_uncharge(&batch->memcg->memsw,
2824 batch->memsw_nr_pages * PAGE_SIZE);
KAMEZAWA Hiroyuki3c11ecf2010-05-26 14:42:37 -07002825 memcg_oom_recover(batch->memcg);
KAMEZAWA Hiroyuki569b8462009-12-15 16:47:03 -08002826 /* forget this pointer (for sanity check) */
2827 batch->memcg = NULL;
2828}
2829
Daisuke Nishimurae767e052009-05-28 14:34:28 -07002830#ifdef CONFIG_SWAP
KAMEZAWA Hiroyuki8c7c6e342009-01-07 18:08:00 -08002831/*
Daisuke Nishimurae767e052009-05-28 14:34:28 -07002832 * called after __delete_from_swap_cache() and drop "page" account.
KAMEZAWA Hiroyuki8c7c6e342009-01-07 18:08:00 -08002833 * memcg information is recorded to swap_cgroup of "ent"
2834 */
KAMEZAWA Hiroyuki8a9478c2009-06-17 16:27:17 -07002835void
2836mem_cgroup_uncharge_swapcache(struct page *page, swp_entry_t ent, bool swapout)
KAMEZAWA Hiroyukid13d1442009-01-07 18:07:56 -08002837{
KAMEZAWA Hiroyuki8c7c6e342009-01-07 18:08:00 -08002838 struct mem_cgroup *memcg;
KAMEZAWA Hiroyuki8a9478c2009-06-17 16:27:17 -07002839 int ctype = MEM_CGROUP_CHARGE_TYPE_SWAPOUT;
KAMEZAWA Hiroyuki8c7c6e342009-01-07 18:08:00 -08002840
KAMEZAWA Hiroyuki8a9478c2009-06-17 16:27:17 -07002841 if (!swapout) /* this was a swap cache but the swap is unused ! */
2842 ctype = MEM_CGROUP_CHARGE_TYPE_DROP;
2843
2844 memcg = __mem_cgroup_uncharge_common(page, ctype);
2845
KAMEZAWA Hiroyukif75ca962010-08-10 18:03:02 -07002846 /*
2847 * record memcg information, if swapout && memcg != NULL,
2848 * mem_cgroup_get() was called in uncharge().
2849 */
2850 if (do_swap_account && swapout && memcg)
KAMEZAWA Hiroyukia3b2d692009-04-02 16:57:45 -07002851 swap_cgroup_record(ent, css_id(&memcg->css));
KAMEZAWA Hiroyukid13d1442009-01-07 18:07:56 -08002852}
Daisuke Nishimurae767e052009-05-28 14:34:28 -07002853#endif
KAMEZAWA Hiroyukid13d1442009-01-07 18:07:56 -08002854
KAMEZAWA Hiroyuki8c7c6e342009-01-07 18:08:00 -08002855#ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP
2856/*
2857 * called from swap_entry_free(). remove record in swap_cgroup and
2858 * uncharge "memsw" account.
2859 */
2860void mem_cgroup_uncharge_swap(swp_entry_t ent)
2861{
2862 struct mem_cgroup *memcg;
KAMEZAWA Hiroyukia3b2d692009-04-02 16:57:45 -07002863 unsigned short id;
KAMEZAWA Hiroyuki8c7c6e342009-01-07 18:08:00 -08002864
2865 if (!do_swap_account)
2866 return;
2867
KAMEZAWA Hiroyukia3b2d692009-04-02 16:57:45 -07002868 id = swap_cgroup_record(ent, 0);
2869 rcu_read_lock();
2870 memcg = mem_cgroup_lookup(id);
KAMEZAWA Hiroyuki8c7c6e342009-01-07 18:08:00 -08002871 if (memcg) {
KAMEZAWA Hiroyukia3b2d692009-04-02 16:57:45 -07002872 /*
2873 * We uncharge this because swap is freed.
2874 * This memcg can be obsolete one. We avoid calling css_tryget
2875 */
Balbir Singh0c3e73e2009-09-23 15:56:42 -07002876 if (!mem_cgroup_is_root(memcg))
KAMEZAWA Hiroyuki4e649152009-10-01 15:44:11 -07002877 res_counter_uncharge(&memcg->memsw, PAGE_SIZE);
Balbir Singh0c3e73e2009-09-23 15:56:42 -07002878 mem_cgroup_swap_statistics(memcg, false);
KAMEZAWA Hiroyuki8c7c6e342009-01-07 18:08:00 -08002879 mem_cgroup_put(memcg);
2880 }
KAMEZAWA Hiroyukia3b2d692009-04-02 16:57:45 -07002881 rcu_read_unlock();
KAMEZAWA Hiroyuki8c7c6e342009-01-07 18:08:00 -08002882}
Daisuke Nishimura02491442010-03-10 15:22:17 -08002883
2884/**
2885 * mem_cgroup_move_swap_account - move swap charge and swap_cgroup's record.
2886 * @entry: swap entry to be moved
2887 * @from: mem_cgroup which the entry is moved from
2888 * @to: mem_cgroup which the entry is moved to
Daisuke Nishimura483c30b2010-03-10 15:22:18 -08002889 * @need_fixup: whether we should fixup res_counters and refcounts.
Daisuke Nishimura02491442010-03-10 15:22:17 -08002890 *
2891 * It succeeds only when the swap_cgroup's record for this entry is the same
2892 * as the mem_cgroup's id of @from.
2893 *
2894 * Returns 0 on success, -EINVAL on failure.
2895 *
2896 * The caller must have charged to @to, IOW, called res_counter_charge() about
2897 * both res and memsw, and called css_get().
2898 */
2899static int mem_cgroup_move_swap_account(swp_entry_t entry,
Daisuke Nishimura483c30b2010-03-10 15:22:18 -08002900 struct mem_cgroup *from, struct mem_cgroup *to, bool need_fixup)
Daisuke Nishimura02491442010-03-10 15:22:17 -08002901{
2902 unsigned short old_id, new_id;
2903
2904 old_id = css_id(&from->css);
2905 new_id = css_id(&to->css);
2906
2907 if (swap_cgroup_cmpxchg(entry, old_id, new_id) == old_id) {
Daisuke Nishimura02491442010-03-10 15:22:17 -08002908 mem_cgroup_swap_statistics(from, false);
Daisuke Nishimura02491442010-03-10 15:22:17 -08002909 mem_cgroup_swap_statistics(to, true);
Daisuke Nishimura483c30b2010-03-10 15:22:18 -08002910 /*
2911 * This function is only called from task migration context now.
2912 * It postpones res_counter and refcount handling till the end
2913 * of task migration(mem_cgroup_clear_mc()) for performance
2914 * improvement. But we cannot postpone mem_cgroup_get(to)
2915 * because if the process that has been moved to @to does
2916 * swap-in, the refcount of @to might be decreased to 0.
2917 */
Daisuke Nishimura02491442010-03-10 15:22:17 -08002918 mem_cgroup_get(to);
Daisuke Nishimura483c30b2010-03-10 15:22:18 -08002919 if (need_fixup) {
2920 if (!mem_cgroup_is_root(from))
2921 res_counter_uncharge(&from->memsw, PAGE_SIZE);
2922 mem_cgroup_put(from);
2923 /*
2924 * we charged both to->res and to->memsw, so we should
2925 * uncharge to->res.
2926 */
2927 if (!mem_cgroup_is_root(to))
2928 res_counter_uncharge(&to->res, PAGE_SIZE);
Daisuke Nishimura483c30b2010-03-10 15:22:18 -08002929 }
Daisuke Nishimura02491442010-03-10 15:22:17 -08002930 return 0;
2931 }
2932 return -EINVAL;
2933}
2934#else
2935static inline int mem_cgroup_move_swap_account(swp_entry_t entry,
Daisuke Nishimura483c30b2010-03-10 15:22:18 -08002936 struct mem_cgroup *from, struct mem_cgroup *to, bool need_fixup)
Daisuke Nishimura02491442010-03-10 15:22:17 -08002937{
2938 return -EINVAL;
2939}
KAMEZAWA Hiroyuki8c7c6e342009-01-07 18:08:00 -08002940#endif
2941
KAMEZAWA Hiroyukiae41be32008-02-07 00:14:10 -08002942/*
KAMEZAWA Hiroyuki01b1ae62009-01-07 18:07:50 -08002943 * Before starting migration, account PAGE_SIZE to mem_cgroup that the old
2944 * page belongs to.
KAMEZAWA Hiroyukiae41be32008-02-07 00:14:10 -08002945 */
akpm@linux-foundation.orgac39cf82010-05-26 14:42:46 -07002946int mem_cgroup_prepare_migration(struct page *page,
Miklos Szeredief6a3c62011-03-22 16:30:52 -07002947 struct page *newpage, struct mem_cgroup **ptr, gfp_t gfp_mask)
KAMEZAWA Hiroyukiae41be32008-02-07 00:14:10 -08002948{
KAMEZAWA Hiroyukie8589cc2008-07-25 01:47:10 -07002949 struct mem_cgroup *mem = NULL;
Johannes Weiner7ec99d62011-03-23 16:42:36 -07002950 struct page_cgroup *pc;
akpm@linux-foundation.orgac39cf82010-05-26 14:42:46 -07002951 enum charge_type ctype;
KAMEZAWA Hiroyukie8589cc2008-07-25 01:47:10 -07002952 int ret = 0;
Hugh Dickins8869b8f2008-03-04 14:29:09 -08002953
KAMEZAWA Hiroyuki56039ef2011-03-23 16:42:19 -07002954 *ptr = NULL;
2955
Andrea Arcangeliec168512011-01-13 15:46:56 -08002956 VM_BUG_ON(PageTransHuge(page));
Hirokazu Takahashif8d665422009-01-07 18:08:02 -08002957 if (mem_cgroup_disabled())
Balbir Singh40779602008-04-04 14:29:59 -07002958 return 0;
2959
KAMEZAWA Hiroyuki52d4b9a2008-10-18 20:28:16 -07002960 pc = lookup_page_cgroup(page);
2961 lock_page_cgroup(pc);
2962 if (PageCgroupUsed(pc)) {
KAMEZAWA Hiroyukie8589cc2008-07-25 01:47:10 -07002963 mem = pc->mem_cgroup;
2964 css_get(&mem->css);
akpm@linux-foundation.orgac39cf82010-05-26 14:42:46 -07002965 /*
2966 * At migrating an anonymous page, its mapcount goes down
2967 * to 0 and uncharge() will be called. But, even if it's fully
2968 * unmapped, migration may fail and this page has to be
2969 * charged again. We set MIGRATION flag here and delay uncharge
2970 * until end_migration() is called
2971 *
2972 * Corner Case Thinking
2973 * A)
2974 * When the old page was mapped as Anon and it's unmap-and-freed
2975 * while migration was ongoing.
2976 * If unmap finds the old page, uncharge() of it will be delayed
2977 * until end_migration(). If unmap finds a new page, it's
2978 * uncharged when it make mapcount to be 1->0. If unmap code
2979 * finds swap_migration_entry, the new page will not be mapped
2980 * and end_migration() will find it(mapcount==0).
2981 *
2982 * B)
2983 * When the old page was mapped but migraion fails, the kernel
2984 * remaps it. A charge for it is kept by MIGRATION flag even
2985 * if mapcount goes down to 0. We can do remap successfully
2986 * without charging it again.
2987 *
2988 * C)
2989 * The "old" page is under lock_page() until the end of
2990 * migration, so, the old page itself will not be swapped-out.
2991 * If the new page is swapped out before end_migraton, our
2992 * hook to usual swap-out path will catch the event.
2993 */
2994 if (PageAnon(page))
2995 SetPageCgroupMigration(pc);
Hugh Dickinsb9c565d2008-03-04 14:29:11 -08002996 }
KAMEZAWA Hiroyuki52d4b9a2008-10-18 20:28:16 -07002997 unlock_page_cgroup(pc);
akpm@linux-foundation.orgac39cf82010-05-26 14:42:46 -07002998 /*
2999 * If the page is not charged at this point,
3000 * we return here.
3001 */
3002 if (!mem)
3003 return 0;
KAMEZAWA Hiroyuki01b1ae62009-01-07 18:07:50 -08003004
Andrea Arcangeli93d5c9b2010-04-23 13:17:39 -04003005 *ptr = mem;
Johannes Weiner7ec99d62011-03-23 16:42:36 -07003006 ret = __mem_cgroup_try_charge(NULL, gfp_mask, 1, ptr, false);
akpm@linux-foundation.orgac39cf82010-05-26 14:42:46 -07003007 css_put(&mem->css);/* drop extra refcnt */
3008 if (ret || *ptr == NULL) {
3009 if (PageAnon(page)) {
3010 lock_page_cgroup(pc);
3011 ClearPageCgroupMigration(pc);
3012 unlock_page_cgroup(pc);
3013 /*
3014 * The old page may be fully unmapped while we kept it.
3015 */
3016 mem_cgroup_uncharge_page(page);
3017 }
3018 return -ENOMEM;
KAMEZAWA Hiroyukie8589cc2008-07-25 01:47:10 -07003019 }
akpm@linux-foundation.orgac39cf82010-05-26 14:42:46 -07003020 /*
3021 * We charge new page before it's used/mapped. So, even if unlock_page()
3022 * is called before end_migration, we can catch all events on this new
3023 * page. In the case new page is migrated but not remapped, new page's
3024 * mapcount will be finally 0 and we call uncharge in end_migration().
3025 */
3026 pc = lookup_page_cgroup(newpage);
3027 if (PageAnon(page))
3028 ctype = MEM_CGROUP_CHARGE_TYPE_MAPPED;
3029 else if (page_is_file_cache(page))
3030 ctype = MEM_CGROUP_CHARGE_TYPE_CACHE;
3031 else
3032 ctype = MEM_CGROUP_CHARGE_TYPE_SHMEM;
Johannes Weiner7ec99d62011-03-23 16:42:36 -07003033 __mem_cgroup_commit_charge(mem, page, 1, pc, ctype);
KAMEZAWA Hiroyukie8589cc2008-07-25 01:47:10 -07003034 return ret;
3035}
Hugh Dickinsfb59e9f2008-03-04 14:29:16 -08003036
KAMEZAWA Hiroyuki69029cd2008-07-25 01:47:14 -07003037/* remove redundant charge if migration failed*/
KAMEZAWA Hiroyuki01b1ae62009-01-07 18:07:50 -08003038void mem_cgroup_end_migration(struct mem_cgroup *mem,
Daisuke Nishimura50de1dd2011-01-13 15:47:43 -08003039 struct page *oldpage, struct page *newpage, bool migration_ok)
KAMEZAWA Hiroyukie8589cc2008-07-25 01:47:10 -07003040{
akpm@linux-foundation.orgac39cf82010-05-26 14:42:46 -07003041 struct page *used, *unused;
KAMEZAWA Hiroyuki01b1ae62009-01-07 18:07:50 -08003042 struct page_cgroup *pc;
KAMEZAWA Hiroyuki01b1ae62009-01-07 18:07:50 -08003043
3044 if (!mem)
3045 return;
akpm@linux-foundation.orgac39cf82010-05-26 14:42:46 -07003046 /* blocks rmdir() */
KAMEZAWA Hiroyuki88703262009-07-29 15:04:06 -07003047 cgroup_exclude_rmdir(&mem->css);
Daisuke Nishimura50de1dd2011-01-13 15:47:43 -08003048 if (!migration_ok) {
akpm@linux-foundation.orgac39cf82010-05-26 14:42:46 -07003049 used = oldpage;
3050 unused = newpage;
KAMEZAWA Hiroyuki01b1ae62009-01-07 18:07:50 -08003051 } else {
akpm@linux-foundation.orgac39cf82010-05-26 14:42:46 -07003052 used = newpage;
KAMEZAWA Hiroyuki01b1ae62009-01-07 18:07:50 -08003053 unused = oldpage;
3054 }
KAMEZAWA Hiroyuki69029cd2008-07-25 01:47:14 -07003055 /*
akpm@linux-foundation.orgac39cf82010-05-26 14:42:46 -07003056 * We disallowed uncharge of pages under migration because mapcount
3057 * of the page goes down to zero, temporarly.
3058 * Clear the flag and check the page should be charged.
KAMEZAWA Hiroyuki69029cd2008-07-25 01:47:14 -07003059 */
akpm@linux-foundation.orgac39cf82010-05-26 14:42:46 -07003060 pc = lookup_page_cgroup(oldpage);
3061 lock_page_cgroup(pc);
3062 ClearPageCgroupMigration(pc);
3063 unlock_page_cgroup(pc);
KAMEZAWA Hiroyuki01b1ae62009-01-07 18:07:50 -08003064
akpm@linux-foundation.orgac39cf82010-05-26 14:42:46 -07003065 __mem_cgroup_uncharge_common(unused, MEM_CGROUP_CHARGE_TYPE_FORCE);
3066
KAMEZAWA Hiroyuki01b1ae62009-01-07 18:07:50 -08003067 /*
akpm@linux-foundation.orgac39cf82010-05-26 14:42:46 -07003068 * If a page is a file cache, radix-tree replacement is very atomic
3069 * and we can skip this check. When it was an Anon page, its mapcount
3070 * goes down to 0. But because we added MIGRATION flage, it's not
3071 * uncharged yet. There are several case but page->mapcount check
3072 * and USED bit check in mem_cgroup_uncharge_page() will do enough
3073 * check. (see prepare_charge() also)
KAMEZAWA Hiroyuki01b1ae62009-01-07 18:07:50 -08003074 */
akpm@linux-foundation.orgac39cf82010-05-26 14:42:46 -07003075 if (PageAnon(used))
3076 mem_cgroup_uncharge_page(used);
KAMEZAWA Hiroyuki88703262009-07-29 15:04:06 -07003077 /*
akpm@linux-foundation.orgac39cf82010-05-26 14:42:46 -07003078 * At migration, we may charge account against cgroup which has no
3079 * tasks.
KAMEZAWA Hiroyuki88703262009-07-29 15:04:06 -07003080 * So, rmdir()->pre_destroy() can be called while we do this charge.
3081 * In that case, we need to call pre_destroy() again. check it here.
3082 */
3083 cgroup_release_and_wakeup_rmdir(&mem->css);
KAMEZAWA Hiroyukiae41be32008-02-07 00:14:10 -08003084}
Pavel Emelianov78fb7462008-02-07 00:13:51 -08003085
KAMEZAWA Hiroyukicc847582008-02-07 00:14:16 -08003086/*
Daisuke Nishimuraae3abae2009-04-30 15:08:19 -07003087 * A call to try to shrink memory usage on charge failure at shmem's swapin.
3088 * Calling hierarchical_reclaim is not enough because we should update
3089 * last_oom_jiffies to prevent pagefault_out_of_memory from invoking global OOM.
3090 * Moreover considering hierarchy, we should reclaim from the mem_over_limit,
3091 * not from the memcg which this page would be charged to.
3092 * try_charge_swapin does all of these works properly.
KAMEZAWA Hiroyukic9b0ed52008-07-25 01:47:15 -07003093 */
Daisuke Nishimuraae3abae2009-04-30 15:08:19 -07003094int mem_cgroup_shmem_charge_fallback(struct page *page,
KAMEZAWA Hiroyukib5a84312009-01-07 18:08:35 -08003095 struct mm_struct *mm,
3096 gfp_t gfp_mask)
KAMEZAWA Hiroyukic9b0ed52008-07-25 01:47:15 -07003097{
KAMEZAWA Hiroyuki56039ef2011-03-23 16:42:19 -07003098 struct mem_cgroup *mem;
Daisuke Nishimuraae3abae2009-04-30 15:08:19 -07003099 int ret;
KAMEZAWA Hiroyukic9b0ed52008-07-25 01:47:15 -07003100
Hirokazu Takahashif8d665422009-01-07 18:08:02 -08003101 if (mem_cgroup_disabled())
Li Zefancede86a2008-07-25 01:47:18 -07003102 return 0;
KAMEZAWA Hiroyukic9b0ed52008-07-25 01:47:15 -07003103
Daisuke Nishimuraae3abae2009-04-30 15:08:19 -07003104 ret = mem_cgroup_try_charge_swapin(mm, page, gfp_mask, &mem);
3105 if (!ret)
3106 mem_cgroup_cancel_charge_swapin(mem); /* it does !mem check */
KAMEZAWA Hiroyukic9b0ed52008-07-25 01:47:15 -07003107
Daisuke Nishimuraae3abae2009-04-30 15:08:19 -07003108 return ret;
KAMEZAWA Hiroyukic9b0ed52008-07-25 01:47:15 -07003109}
3110
Daisuke Nishimuraf212ad72011-03-23 16:42:25 -07003111#ifdef CONFIG_DEBUG_VM
3112static struct page_cgroup *lookup_page_cgroup_used(struct page *page)
3113{
3114 struct page_cgroup *pc;
3115
3116 pc = lookup_page_cgroup(page);
3117 if (likely(pc) && PageCgroupUsed(pc))
3118 return pc;
3119 return NULL;
3120}
3121
3122bool mem_cgroup_bad_page_check(struct page *page)
3123{
3124 if (mem_cgroup_disabled())
3125 return false;
3126
3127 return lookup_page_cgroup_used(page) != NULL;
3128}
3129
3130void mem_cgroup_print_bad_page(struct page *page)
3131{
3132 struct page_cgroup *pc;
3133
3134 pc = lookup_page_cgroup_used(page);
3135 if (pc) {
3136 int ret = -1;
3137 char *path;
3138
3139 printk(KERN_ALERT "pc:%p pc->flags:%lx pc->mem_cgroup:%p",
3140 pc, pc->flags, pc->mem_cgroup);
3141
3142 path = kmalloc(PATH_MAX, GFP_KERNEL);
3143 if (path) {
3144 rcu_read_lock();
3145 ret = cgroup_path(pc->mem_cgroup->css.cgroup,
3146 path, PATH_MAX);
3147 rcu_read_unlock();
3148 }
3149
3150 printk(KERN_CONT "(%s)\n",
3151 (ret < 0) ? "cannot get the path" : path);
3152 kfree(path);
3153 }
3154}
3155#endif
3156
KAMEZAWA Hiroyuki8c7c6e342009-01-07 18:08:00 -08003157static DEFINE_MUTEX(set_limit_mutex);
3158
KOSAKI Motohirod38d2a72009-01-06 14:39:44 -08003159static int mem_cgroup_resize_limit(struct mem_cgroup *memcg,
KAMEZAWA Hiroyuki8c7c6e342009-01-07 18:08:00 -08003160 unsigned long long val)
KAMEZAWA Hiroyuki628f4232008-07-25 01:47:20 -07003161{
KAMEZAWA Hiroyuki81d39c22009-04-02 16:57:36 -07003162 int retry_count;
KAMEZAWA Hiroyuki3c11ecf2010-05-26 14:42:37 -07003163 u64 memswlimit, memlimit;
KAMEZAWA Hiroyuki628f4232008-07-25 01:47:20 -07003164 int ret = 0;
KAMEZAWA Hiroyuki81d39c22009-04-02 16:57:36 -07003165 int children = mem_cgroup_count_children(memcg);
3166 u64 curusage, oldusage;
KAMEZAWA Hiroyuki3c11ecf2010-05-26 14:42:37 -07003167 int enlarge;
KAMEZAWA Hiroyuki81d39c22009-04-02 16:57:36 -07003168
3169 /*
3170 * For keeping hierarchical_reclaim simple, how long we should retry
3171 * is depends on callers. We set our retry-count to be function
3172 * of # of children which we should visit in this loop.
3173 */
3174 retry_count = MEM_CGROUP_RECLAIM_RETRIES * children;
3175
3176 oldusage = res_counter_read_u64(&memcg->res, RES_USAGE);
KAMEZAWA Hiroyuki628f4232008-07-25 01:47:20 -07003177
KAMEZAWA Hiroyuki3c11ecf2010-05-26 14:42:37 -07003178 enlarge = 0;
KAMEZAWA Hiroyuki8c7c6e342009-01-07 18:08:00 -08003179 while (retry_count) {
KAMEZAWA Hiroyuki628f4232008-07-25 01:47:20 -07003180 if (signal_pending(current)) {
3181 ret = -EINTR;
3182 break;
3183 }
KAMEZAWA Hiroyuki8c7c6e342009-01-07 18:08:00 -08003184 /*
3185 * Rather than hide all in some function, I do this in
3186 * open coded manner. You see what this really does.
3187 * We have to guarantee mem->res.limit < mem->memsw.limit.
3188 */
3189 mutex_lock(&set_limit_mutex);
3190 memswlimit = res_counter_read_u64(&memcg->memsw, RES_LIMIT);
3191 if (memswlimit < val) {
3192 ret = -EINVAL;
3193 mutex_unlock(&set_limit_mutex);
KAMEZAWA Hiroyuki628f4232008-07-25 01:47:20 -07003194 break;
3195 }
KAMEZAWA Hiroyuki3c11ecf2010-05-26 14:42:37 -07003196
3197 memlimit = res_counter_read_u64(&memcg->res, RES_LIMIT);
3198 if (memlimit < val)
3199 enlarge = 1;
3200
KAMEZAWA Hiroyuki8c7c6e342009-01-07 18:08:00 -08003201 ret = res_counter_set_limit(&memcg->res, val);
KAMEZAWA Hiroyuki22a668d2009-06-17 16:27:19 -07003202 if (!ret) {
3203 if (memswlimit == val)
3204 memcg->memsw_is_minimum = true;
3205 else
3206 memcg->memsw_is_minimum = false;
3207 }
KAMEZAWA Hiroyuki8c7c6e342009-01-07 18:08:00 -08003208 mutex_unlock(&set_limit_mutex);
3209
3210 if (!ret)
3211 break;
3212
Bob Liuaa20d482009-12-15 16:47:14 -08003213 mem_cgroup_hierarchical_reclaim(memcg, NULL, GFP_KERNEL,
Balbir Singh4e416952009-09-23 15:56:39 -07003214 MEM_CGROUP_RECLAIM_SHRINK);
KAMEZAWA Hiroyuki81d39c22009-04-02 16:57:36 -07003215 curusage = res_counter_read_u64(&memcg->res, RES_USAGE);
3216 /* Usage is reduced ? */
3217 if (curusage >= oldusage)
3218 retry_count--;
3219 else
3220 oldusage = curusage;
KAMEZAWA Hiroyuki8c7c6e342009-01-07 18:08:00 -08003221 }
KAMEZAWA Hiroyuki3c11ecf2010-05-26 14:42:37 -07003222 if (!ret && enlarge)
3223 memcg_oom_recover(memcg);
KOSAKI Motohiro14797e22009-01-07 18:08:18 -08003224
KAMEZAWA Hiroyuki8c7c6e342009-01-07 18:08:00 -08003225 return ret;
3226}
3227
Li Zefan338c8432009-06-17 16:27:15 -07003228static int mem_cgroup_resize_memsw_limit(struct mem_cgroup *memcg,
3229 unsigned long long val)
KAMEZAWA Hiroyuki8c7c6e342009-01-07 18:08:00 -08003230{
KAMEZAWA Hiroyuki81d39c22009-04-02 16:57:36 -07003231 int retry_count;
KAMEZAWA Hiroyuki3c11ecf2010-05-26 14:42:37 -07003232 u64 memlimit, memswlimit, oldusage, curusage;
KAMEZAWA Hiroyuki81d39c22009-04-02 16:57:36 -07003233 int children = mem_cgroup_count_children(memcg);
3234 int ret = -EBUSY;
KAMEZAWA Hiroyuki3c11ecf2010-05-26 14:42:37 -07003235 int enlarge = 0;
KAMEZAWA Hiroyuki8c7c6e342009-01-07 18:08:00 -08003236
KAMEZAWA Hiroyuki81d39c22009-04-02 16:57:36 -07003237 /* see mem_cgroup_resize_res_limit */
3238 retry_count = children * MEM_CGROUP_RECLAIM_RETRIES;
3239 oldusage = res_counter_read_u64(&memcg->memsw, RES_USAGE);
KAMEZAWA Hiroyuki8c7c6e342009-01-07 18:08:00 -08003240 while (retry_count) {
3241 if (signal_pending(current)) {
3242 ret = -EINTR;
3243 break;
3244 }
3245 /*
3246 * Rather than hide all in some function, I do this in
3247 * open coded manner. You see what this really does.
3248 * We have to guarantee mem->res.limit < mem->memsw.limit.
3249 */
3250 mutex_lock(&set_limit_mutex);
3251 memlimit = res_counter_read_u64(&memcg->res, RES_LIMIT);
3252 if (memlimit > val) {
3253 ret = -EINVAL;
3254 mutex_unlock(&set_limit_mutex);
3255 break;
3256 }
KAMEZAWA Hiroyuki3c11ecf2010-05-26 14:42:37 -07003257 memswlimit = res_counter_read_u64(&memcg->memsw, RES_LIMIT);
3258 if (memswlimit < val)
3259 enlarge = 1;
KAMEZAWA Hiroyuki8c7c6e342009-01-07 18:08:00 -08003260 ret = res_counter_set_limit(&memcg->memsw, val);
KAMEZAWA Hiroyuki22a668d2009-06-17 16:27:19 -07003261 if (!ret) {
3262 if (memlimit == val)
3263 memcg->memsw_is_minimum = true;
3264 else
3265 memcg->memsw_is_minimum = false;
3266 }
KAMEZAWA Hiroyuki8c7c6e342009-01-07 18:08:00 -08003267 mutex_unlock(&set_limit_mutex);
3268
3269 if (!ret)
3270 break;
3271
Balbir Singh4e416952009-09-23 15:56:39 -07003272 mem_cgroup_hierarchical_reclaim(memcg, NULL, GFP_KERNEL,
Balbir Singh75822b42009-09-23 15:56:38 -07003273 MEM_CGROUP_RECLAIM_NOSWAP |
3274 MEM_CGROUP_RECLAIM_SHRINK);
KAMEZAWA Hiroyuki8c7c6e342009-01-07 18:08:00 -08003275 curusage = res_counter_read_u64(&memcg->memsw, RES_USAGE);
KAMEZAWA Hiroyuki81d39c22009-04-02 16:57:36 -07003276 /* Usage is reduced ? */
KAMEZAWA Hiroyuki8c7c6e342009-01-07 18:08:00 -08003277 if (curusage >= oldusage)
KAMEZAWA Hiroyuki628f4232008-07-25 01:47:20 -07003278 retry_count--;
KAMEZAWA Hiroyuki81d39c22009-04-02 16:57:36 -07003279 else
3280 oldusage = curusage;
KAMEZAWA Hiroyuki628f4232008-07-25 01:47:20 -07003281 }
KAMEZAWA Hiroyuki3c11ecf2010-05-26 14:42:37 -07003282 if (!ret && enlarge)
3283 memcg_oom_recover(memcg);
KAMEZAWA Hiroyuki628f4232008-07-25 01:47:20 -07003284 return ret;
3285}
3286
Balbir Singh4e416952009-09-23 15:56:39 -07003287unsigned long mem_cgroup_soft_limit_reclaim(struct zone *zone, int order,
KOSAKI Motohiro00918b62010-08-10 18:03:05 -07003288 gfp_t gfp_mask)
Balbir Singh4e416952009-09-23 15:56:39 -07003289{
3290 unsigned long nr_reclaimed = 0;
3291 struct mem_cgroup_per_zone *mz, *next_mz = NULL;
3292 unsigned long reclaimed;
3293 int loop = 0;
3294 struct mem_cgroup_tree_per_zone *mctz;
KAMEZAWA Hiroyukief8745c2009-10-01 15:44:12 -07003295 unsigned long long excess;
Balbir Singh4e416952009-09-23 15:56:39 -07003296
3297 if (order > 0)
3298 return 0;
3299
KOSAKI Motohiro00918b62010-08-10 18:03:05 -07003300 mctz = soft_limit_tree_node_zone(zone_to_nid(zone), zone_idx(zone));
Balbir Singh4e416952009-09-23 15:56:39 -07003301 /*
3302 * This loop can run a while, specially if mem_cgroup's continuously
3303 * keep exceeding their soft limit and putting the system under
3304 * pressure
3305 */
3306 do {
3307 if (next_mz)
3308 mz = next_mz;
3309 else
3310 mz = mem_cgroup_largest_soft_limit_node(mctz);
3311 if (!mz)
3312 break;
3313
3314 reclaimed = mem_cgroup_hierarchical_reclaim(mz->mem, zone,
3315 gfp_mask,
3316 MEM_CGROUP_RECLAIM_SOFT);
3317 nr_reclaimed += reclaimed;
3318 spin_lock(&mctz->lock);
3319
3320 /*
3321 * If we failed to reclaim anything from this memory cgroup
3322 * it is time to move on to the next cgroup
3323 */
3324 next_mz = NULL;
3325 if (!reclaimed) {
3326 do {
3327 /*
3328 * Loop until we find yet another one.
3329 *
3330 * By the time we get the soft_limit lock
3331 * again, someone might have aded the
3332 * group back on the RB tree. Iterate to
3333 * make sure we get a different mem.
3334 * mem_cgroup_largest_soft_limit_node returns
3335 * NULL if no other cgroup is present on
3336 * the tree
3337 */
3338 next_mz =
3339 __mem_cgroup_largest_soft_limit_node(mctz);
3340 if (next_mz == mz) {
3341 css_put(&next_mz->mem->css);
3342 next_mz = NULL;
3343 } else /* next_mz == NULL or other memcg */
3344 break;
3345 } while (1);
3346 }
Balbir Singh4e416952009-09-23 15:56:39 -07003347 __mem_cgroup_remove_exceeded(mz->mem, mz, mctz);
KAMEZAWA Hiroyukief8745c2009-10-01 15:44:12 -07003348 excess = res_counter_soft_limit_excess(&mz->mem->res);
Balbir Singh4e416952009-09-23 15:56:39 -07003349 /*
3350 * One school of thought says that we should not add
3351 * back the node to the tree if reclaim returns 0.
3352 * But our reclaim could return 0, simply because due
3353 * to priority we are exposing a smaller subset of
3354 * memory to reclaim from. Consider this as a longer
3355 * term TODO.
3356 */
KAMEZAWA Hiroyukief8745c2009-10-01 15:44:12 -07003357 /* If excess == 0, no tree ops */
3358 __mem_cgroup_insert_exceeded(mz->mem, mz, mctz, excess);
Balbir Singh4e416952009-09-23 15:56:39 -07003359 spin_unlock(&mctz->lock);
3360 css_put(&mz->mem->css);
3361 loop++;
3362 /*
3363 * Could not reclaim anything and there are no more
3364 * mem cgroups to try or we seem to be looping without
3365 * reclaiming anything.
3366 */
3367 if (!nr_reclaimed &&
3368 (next_mz == NULL ||
3369 loop > MEM_CGROUP_MAX_SOFT_LIMIT_RECLAIM_LOOPS))
3370 break;
3371 } while (!nr_reclaimed);
3372 if (next_mz)
3373 css_put(&next_mz->mem->css);
3374 return nr_reclaimed;
3375}
3376
KAMEZAWA Hiroyukic9b0ed52008-07-25 01:47:15 -07003377/*
KAMEZAWA Hiroyukicc847582008-02-07 00:14:16 -08003378 * This routine traverse page_cgroup in given list and drop them all.
KAMEZAWA Hiroyukicc847582008-02-07 00:14:16 -08003379 * *And* this routine doesn't reclaim page itself, just removes page_cgroup.
3380 */
KAMEZAWA Hiroyukif817ed42009-01-07 18:07:53 -08003381static int mem_cgroup_force_empty_list(struct mem_cgroup *mem,
KAMEZAWA Hiroyuki08e552c2009-01-07 18:08:01 -08003382 int node, int zid, enum lru_list lru)
KAMEZAWA Hiroyukicc847582008-02-07 00:14:16 -08003383{
KAMEZAWA Hiroyuki08e552c2009-01-07 18:08:01 -08003384 struct zone *zone;
3385 struct mem_cgroup_per_zone *mz;
KAMEZAWA Hiroyukif817ed42009-01-07 18:07:53 -08003386 struct page_cgroup *pc, *busy;
KAMEZAWA Hiroyuki08e552c2009-01-07 18:08:01 -08003387 unsigned long flags, loop;
KAMEZAWA Hiroyuki072c56c12008-02-07 00:14:39 -08003388 struct list_head *list;
KAMEZAWA Hiroyukif817ed42009-01-07 18:07:53 -08003389 int ret = 0;
KAMEZAWA Hiroyuki072c56c12008-02-07 00:14:39 -08003390
KAMEZAWA Hiroyuki08e552c2009-01-07 18:08:01 -08003391 zone = &NODE_DATA(node)->node_zones[zid];
3392 mz = mem_cgroup_zoneinfo(mem, node, zid);
Christoph Lameterb69408e2008-10-18 20:26:14 -07003393 list = &mz->lists[lru];
KAMEZAWA Hiroyukicc847582008-02-07 00:14:16 -08003394
KAMEZAWA Hiroyukif817ed42009-01-07 18:07:53 -08003395 loop = MEM_CGROUP_ZSTAT(mz, lru);
3396 /* give some margin against EBUSY etc...*/
3397 loop += 256;
3398 busy = NULL;
3399 while (loop--) {
Johannes Weiner5564e882011-03-23 16:42:29 -07003400 struct page *page;
3401
KAMEZAWA Hiroyukif817ed42009-01-07 18:07:53 -08003402 ret = 0;
KAMEZAWA Hiroyuki08e552c2009-01-07 18:08:01 -08003403 spin_lock_irqsave(&zone->lru_lock, flags);
KAMEZAWA Hiroyukif817ed42009-01-07 18:07:53 -08003404 if (list_empty(list)) {
KAMEZAWA Hiroyuki08e552c2009-01-07 18:08:01 -08003405 spin_unlock_irqrestore(&zone->lru_lock, flags);
KAMEZAWA Hiroyuki52d4b9a2008-10-18 20:28:16 -07003406 break;
3407 }
KAMEZAWA Hiroyukif817ed42009-01-07 18:07:53 -08003408 pc = list_entry(list->prev, struct page_cgroup, lru);
3409 if (busy == pc) {
3410 list_move(&pc->lru, list);
Thiago Farina648bcc72010-03-05 13:42:04 -08003411 busy = NULL;
KAMEZAWA Hiroyuki08e552c2009-01-07 18:08:01 -08003412 spin_unlock_irqrestore(&zone->lru_lock, flags);
KAMEZAWA Hiroyukif817ed42009-01-07 18:07:53 -08003413 continue;
3414 }
KAMEZAWA Hiroyuki08e552c2009-01-07 18:08:01 -08003415 spin_unlock_irqrestore(&zone->lru_lock, flags);
KAMEZAWA Hiroyukif817ed42009-01-07 18:07:53 -08003416
Johannes Weiner6b3ae582011-03-23 16:42:30 -07003417 page = lookup_cgroup_page(pc);
Johannes Weiner5564e882011-03-23 16:42:29 -07003418
3419 ret = mem_cgroup_move_parent(page, pc, mem, GFP_KERNEL);
KAMEZAWA Hiroyukif817ed42009-01-07 18:07:53 -08003420 if (ret == -ENOMEM)
3421 break;
3422
3423 if (ret == -EBUSY || ret == -EINVAL) {
3424 /* found lock contention or "pc" is obsolete. */
3425 busy = pc;
3426 cond_resched();
3427 } else
3428 busy = NULL;
KAMEZAWA Hiroyukicc847582008-02-07 00:14:16 -08003429 }
KAMEZAWA Hiroyuki08e552c2009-01-07 18:08:01 -08003430
KAMEZAWA Hiroyukif817ed42009-01-07 18:07:53 -08003431 if (!ret && !list_empty(list))
3432 return -EBUSY;
3433 return ret;
KAMEZAWA Hiroyukicc847582008-02-07 00:14:16 -08003434}
3435
3436/*
3437 * make mem_cgroup's charge to be 0 if there is no task.
3438 * This enables deleting this mem_cgroup.
3439 */
KAMEZAWA Hiroyukic1e862c2009-01-07 18:07:55 -08003440static int mem_cgroup_force_empty(struct mem_cgroup *mem, bool free_all)
KAMEZAWA Hiroyukicc847582008-02-07 00:14:16 -08003441{
KAMEZAWA Hiroyukif817ed42009-01-07 18:07:53 -08003442 int ret;
3443 int node, zid, shrink;
3444 int nr_retries = MEM_CGROUP_RECLAIM_RETRIES;
KAMEZAWA Hiroyukic1e862c2009-01-07 18:07:55 -08003445 struct cgroup *cgrp = mem->css.cgroup;
Hugh Dickins8869b8f2008-03-04 14:29:09 -08003446
KAMEZAWA Hiroyukicc847582008-02-07 00:14:16 -08003447 css_get(&mem->css);
KAMEZAWA Hiroyukif817ed42009-01-07 18:07:53 -08003448
3449 shrink = 0;
KAMEZAWA Hiroyukic1e862c2009-01-07 18:07:55 -08003450 /* should free all ? */
3451 if (free_all)
3452 goto try_to_free;
KAMEZAWA Hiroyukif817ed42009-01-07 18:07:53 -08003453move_account:
Daisuke Nishimurafce66472010-01-15 17:01:30 -08003454 do {
KAMEZAWA Hiroyukif817ed42009-01-07 18:07:53 -08003455 ret = -EBUSY;
KAMEZAWA Hiroyukic1e862c2009-01-07 18:07:55 -08003456 if (cgroup_task_count(cgrp) || !list_empty(&cgrp->children))
KAMEZAWA Hiroyukicc847582008-02-07 00:14:16 -08003457 goto out;
KAMEZAWA Hiroyukic1e862c2009-01-07 18:07:55 -08003458 ret = -EINTR;
3459 if (signal_pending(current))
3460 goto out;
KAMEZAWA Hiroyuki52d4b9a2008-10-18 20:28:16 -07003461 /* This is for making all *used* pages to be on LRU. */
3462 lru_add_drain_all();
KAMEZAWA Hiroyukicdec2e42009-12-15 16:47:08 -08003463 drain_all_stock_sync();
KAMEZAWA Hiroyukif817ed42009-01-07 18:07:53 -08003464 ret = 0;
KAMEZAWA Hiroyuki32047e22010-10-27 15:33:40 -07003465 mem_cgroup_start_move(mem);
KAMEZAWA Hiroyuki299b4ea2009-01-29 14:25:17 -08003466 for_each_node_state(node, N_HIGH_MEMORY) {
KAMEZAWA Hiroyukif817ed42009-01-07 18:07:53 -08003467 for (zid = 0; !ret && zid < MAX_NR_ZONES; zid++) {
Christoph Lameterb69408e2008-10-18 20:26:14 -07003468 enum lru_list l;
KAMEZAWA Hiroyukif817ed42009-01-07 18:07:53 -08003469 for_each_lru(l) {
3470 ret = mem_cgroup_force_empty_list(mem,
KAMEZAWA Hiroyuki08e552c2009-01-07 18:08:01 -08003471 node, zid, l);
KAMEZAWA Hiroyukif817ed42009-01-07 18:07:53 -08003472 if (ret)
3473 break;
3474 }
KAMEZAWA Hiroyuki1ecaab22008-02-07 00:14:38 -08003475 }
KAMEZAWA Hiroyukif817ed42009-01-07 18:07:53 -08003476 if (ret)
3477 break;
3478 }
KAMEZAWA Hiroyuki32047e22010-10-27 15:33:40 -07003479 mem_cgroup_end_move(mem);
KAMEZAWA Hiroyuki3c11ecf2010-05-26 14:42:37 -07003480 memcg_oom_recover(mem);
KAMEZAWA Hiroyukif817ed42009-01-07 18:07:53 -08003481 /* it seems parent cgroup doesn't have enough mem */
3482 if (ret == -ENOMEM)
3483 goto try_to_free;
KAMEZAWA Hiroyuki52d4b9a2008-10-18 20:28:16 -07003484 cond_resched();
Daisuke Nishimurafce66472010-01-15 17:01:30 -08003485 /* "ret" should also be checked to ensure all lists are empty. */
3486 } while (mem->res.usage > 0 || ret);
KAMEZAWA Hiroyukicc847582008-02-07 00:14:16 -08003487out:
3488 css_put(&mem->css);
3489 return ret;
KAMEZAWA Hiroyukif817ed42009-01-07 18:07:53 -08003490
3491try_to_free:
KAMEZAWA Hiroyukic1e862c2009-01-07 18:07:55 -08003492 /* returns EBUSY if there is a task or if we come here twice. */
3493 if (cgroup_task_count(cgrp) || !list_empty(&cgrp->children) || shrink) {
KAMEZAWA Hiroyukif817ed42009-01-07 18:07:53 -08003494 ret = -EBUSY;
3495 goto out;
3496 }
KAMEZAWA Hiroyukic1e862c2009-01-07 18:07:55 -08003497 /* we call try-to-free pages for make this cgroup empty */
3498 lru_add_drain_all();
KAMEZAWA Hiroyukif817ed42009-01-07 18:07:53 -08003499 /* try to free all pages in this cgroup */
3500 shrink = 1;
3501 while (nr_retries && mem->res.usage > 0) {
3502 int progress;
KAMEZAWA Hiroyukic1e862c2009-01-07 18:07:55 -08003503
3504 if (signal_pending(current)) {
3505 ret = -EINTR;
3506 goto out;
3507 }
KOSAKI Motohiroa7885eb2009-01-07 18:08:24 -08003508 progress = try_to_free_mem_cgroup_pages(mem, GFP_KERNEL,
3509 false, get_swappiness(mem));
KAMEZAWA Hiroyukic1e862c2009-01-07 18:07:55 -08003510 if (!progress) {
KAMEZAWA Hiroyukif817ed42009-01-07 18:07:53 -08003511 nr_retries--;
KAMEZAWA Hiroyukic1e862c2009-01-07 18:07:55 -08003512 /* maybe some writeback is necessary */
Jens Axboe8aa7e842009-07-09 14:52:32 +02003513 congestion_wait(BLK_RW_ASYNC, HZ/10);
KAMEZAWA Hiroyukic1e862c2009-01-07 18:07:55 -08003514 }
KAMEZAWA Hiroyukif817ed42009-01-07 18:07:53 -08003515
3516 }
KAMEZAWA Hiroyuki08e552c2009-01-07 18:08:01 -08003517 lru_add_drain();
KAMEZAWA Hiroyukif817ed42009-01-07 18:07:53 -08003518 /* try move_account...there may be some *locked* pages. */
Daisuke Nishimurafce66472010-01-15 17:01:30 -08003519 goto move_account;
KAMEZAWA Hiroyukicc847582008-02-07 00:14:16 -08003520}
3521
KAMEZAWA Hiroyukic1e862c2009-01-07 18:07:55 -08003522int mem_cgroup_force_empty_write(struct cgroup *cont, unsigned int event)
3523{
3524 return mem_cgroup_force_empty(mem_cgroup_from_cont(cont), true);
3525}
3526
3527
Balbir Singh18f59ea2009-01-07 18:08:07 -08003528static u64 mem_cgroup_hierarchy_read(struct cgroup *cont, struct cftype *cft)
3529{
3530 return mem_cgroup_from_cont(cont)->use_hierarchy;
3531}
3532
3533static int mem_cgroup_hierarchy_write(struct cgroup *cont, struct cftype *cft,
3534 u64 val)
3535{
3536 int retval = 0;
3537 struct mem_cgroup *mem = mem_cgroup_from_cont(cont);
3538 struct cgroup *parent = cont->parent;
3539 struct mem_cgroup *parent_mem = NULL;
3540
3541 if (parent)
3542 parent_mem = mem_cgroup_from_cont(parent);
3543
3544 cgroup_lock();
3545 /*
André Goddard Rosaaf901ca2009-11-14 13:09:05 -02003546 * If parent's use_hierarchy is set, we can't make any modifications
Balbir Singh18f59ea2009-01-07 18:08:07 -08003547 * in the child subtrees. If it is unset, then the change can
3548 * occur, provided the current cgroup has no children.
3549 *
3550 * For the root cgroup, parent_mem is NULL, we allow value to be
3551 * set if there are no children.
3552 */
3553 if ((!parent_mem || !parent_mem->use_hierarchy) &&
3554 (val == 1 || val == 0)) {
3555 if (list_empty(&cont->children))
3556 mem->use_hierarchy = val;
3557 else
3558 retval = -EBUSY;
3559 } else
3560 retval = -EINVAL;
3561 cgroup_unlock();
3562
3563 return retval;
3564}
3565
Balbir Singh0c3e73e2009-09-23 15:56:42 -07003566
Johannes Weiner7a159cc2011-03-23 16:42:38 -07003567static unsigned long mem_cgroup_recursive_stat(struct mem_cgroup *mem,
3568 enum mem_cgroup_stat_index idx)
Balbir Singh0c3e73e2009-09-23 15:56:42 -07003569{
KAMEZAWA Hiroyuki7d74b062010-10-27 15:33:41 -07003570 struct mem_cgroup *iter;
Johannes Weiner7a159cc2011-03-23 16:42:38 -07003571 long val = 0;
Balbir Singh0c3e73e2009-09-23 15:56:42 -07003572
Johannes Weiner7a159cc2011-03-23 16:42:38 -07003573 /* Per-cpu values can be negative, use a signed accumulator */
KAMEZAWA Hiroyuki7d74b062010-10-27 15:33:41 -07003574 for_each_mem_cgroup_tree(iter, mem)
3575 val += mem_cgroup_read_stat(iter, idx);
3576
3577 if (val < 0) /* race ? */
3578 val = 0;
3579 return val;
Balbir Singh0c3e73e2009-09-23 15:56:42 -07003580}
3581
Kirill A. Shutemov104f3922010-03-10 15:22:21 -08003582static inline u64 mem_cgroup_usage(struct mem_cgroup *mem, bool swap)
3583{
KAMEZAWA Hiroyuki7d74b062010-10-27 15:33:41 -07003584 u64 val;
Kirill A. Shutemov104f3922010-03-10 15:22:21 -08003585
3586 if (!mem_cgroup_is_root(mem)) {
3587 if (!swap)
3588 return res_counter_read_u64(&mem->res, RES_USAGE);
3589 else
3590 return res_counter_read_u64(&mem->memsw, RES_USAGE);
3591 }
3592
Johannes Weiner7a159cc2011-03-23 16:42:38 -07003593 val = mem_cgroup_recursive_stat(mem, MEM_CGROUP_STAT_CACHE);
3594 val += mem_cgroup_recursive_stat(mem, MEM_CGROUP_STAT_RSS);
Kirill A. Shutemov104f3922010-03-10 15:22:21 -08003595
KAMEZAWA Hiroyuki7d74b062010-10-27 15:33:41 -07003596 if (swap)
Johannes Weiner7a159cc2011-03-23 16:42:38 -07003597 val += mem_cgroup_recursive_stat(mem, MEM_CGROUP_STAT_SWAPOUT);
Kirill A. Shutemov104f3922010-03-10 15:22:21 -08003598
3599 return val << PAGE_SHIFT;
3600}
3601
Paul Menage2c3daa72008-04-29 00:59:58 -07003602static u64 mem_cgroup_read(struct cgroup *cont, struct cftype *cft)
Balbir Singh8cdea7c2008-02-07 00:13:50 -08003603{
KAMEZAWA Hiroyuki8c7c6e342009-01-07 18:08:00 -08003604 struct mem_cgroup *mem = mem_cgroup_from_cont(cont);
Kirill A. Shutemov104f3922010-03-10 15:22:21 -08003605 u64 val;
KAMEZAWA Hiroyuki8c7c6e342009-01-07 18:08:00 -08003606 int type, name;
3607
3608 type = MEMFILE_TYPE(cft->private);
3609 name = MEMFILE_ATTR(cft->private);
3610 switch (type) {
3611 case _MEM:
Kirill A. Shutemov104f3922010-03-10 15:22:21 -08003612 if (name == RES_USAGE)
3613 val = mem_cgroup_usage(mem, false);
3614 else
Balbir Singh0c3e73e2009-09-23 15:56:42 -07003615 val = res_counter_read_u64(&mem->res, name);
KAMEZAWA Hiroyuki8c7c6e342009-01-07 18:08:00 -08003616 break;
3617 case _MEMSWAP:
Kirill A. Shutemov104f3922010-03-10 15:22:21 -08003618 if (name == RES_USAGE)
3619 val = mem_cgroup_usage(mem, true);
3620 else
Balbir Singh0c3e73e2009-09-23 15:56:42 -07003621 val = res_counter_read_u64(&mem->memsw, name);
KAMEZAWA Hiroyuki8c7c6e342009-01-07 18:08:00 -08003622 break;
3623 default:
3624 BUG();
3625 break;
3626 }
3627 return val;
Balbir Singh8cdea7c2008-02-07 00:13:50 -08003628}
KAMEZAWA Hiroyuki628f4232008-07-25 01:47:20 -07003629/*
3630 * The user of this function is...
3631 * RES_LIMIT.
3632 */
Paul Menage856c13a2008-07-25 01:47:04 -07003633static int mem_cgroup_write(struct cgroup *cont, struct cftype *cft,
3634 const char *buffer)
Balbir Singh8cdea7c2008-02-07 00:13:50 -08003635{
KAMEZAWA Hiroyuki628f4232008-07-25 01:47:20 -07003636 struct mem_cgroup *memcg = mem_cgroup_from_cont(cont);
KAMEZAWA Hiroyuki8c7c6e342009-01-07 18:08:00 -08003637 int type, name;
KAMEZAWA Hiroyuki628f4232008-07-25 01:47:20 -07003638 unsigned long long val;
3639 int ret;
3640
KAMEZAWA Hiroyuki8c7c6e342009-01-07 18:08:00 -08003641 type = MEMFILE_TYPE(cft->private);
3642 name = MEMFILE_ATTR(cft->private);
3643 switch (name) {
KAMEZAWA Hiroyuki628f4232008-07-25 01:47:20 -07003644 case RES_LIMIT:
Balbir Singh4b3bde42009-09-23 15:56:32 -07003645 if (mem_cgroup_is_root(memcg)) { /* Can't set limit on root */
3646 ret = -EINVAL;
3647 break;
3648 }
KAMEZAWA Hiroyuki628f4232008-07-25 01:47:20 -07003649 /* This function does all necessary parse...reuse it */
3650 ret = res_counter_memparse_write_strategy(buffer, &val);
KAMEZAWA Hiroyuki8c7c6e342009-01-07 18:08:00 -08003651 if (ret)
3652 break;
3653 if (type == _MEM)
KAMEZAWA Hiroyuki628f4232008-07-25 01:47:20 -07003654 ret = mem_cgroup_resize_limit(memcg, val);
KAMEZAWA Hiroyuki8c7c6e342009-01-07 18:08:00 -08003655 else
3656 ret = mem_cgroup_resize_memsw_limit(memcg, val);
KAMEZAWA Hiroyuki628f4232008-07-25 01:47:20 -07003657 break;
Balbir Singh296c81d2009-09-23 15:56:36 -07003658 case RES_SOFT_LIMIT:
3659 ret = res_counter_memparse_write_strategy(buffer, &val);
3660 if (ret)
3661 break;
3662 /*
3663 * For memsw, soft limits are hard to implement in terms
3664 * of semantics, for now, we support soft limits for
3665 * control without swap
3666 */
3667 if (type == _MEM)
3668 ret = res_counter_set_soft_limit(&memcg->res, val);
3669 else
3670 ret = -EINVAL;
3671 break;
KAMEZAWA Hiroyuki628f4232008-07-25 01:47:20 -07003672 default:
3673 ret = -EINVAL; /* should be BUG() ? */
3674 break;
3675 }
3676 return ret;
Balbir Singh8cdea7c2008-02-07 00:13:50 -08003677}
3678
KAMEZAWA Hiroyukifee7b542009-01-07 18:08:26 -08003679static void memcg_get_hierarchical_limit(struct mem_cgroup *memcg,
3680 unsigned long long *mem_limit, unsigned long long *memsw_limit)
3681{
3682 struct cgroup *cgroup;
3683 unsigned long long min_limit, min_memsw_limit, tmp;
3684
3685 min_limit = res_counter_read_u64(&memcg->res, RES_LIMIT);
3686 min_memsw_limit = res_counter_read_u64(&memcg->memsw, RES_LIMIT);
3687 cgroup = memcg->css.cgroup;
3688 if (!memcg->use_hierarchy)
3689 goto out;
3690
3691 while (cgroup->parent) {
3692 cgroup = cgroup->parent;
3693 memcg = mem_cgroup_from_cont(cgroup);
3694 if (!memcg->use_hierarchy)
3695 break;
3696 tmp = res_counter_read_u64(&memcg->res, RES_LIMIT);
3697 min_limit = min(min_limit, tmp);
3698 tmp = res_counter_read_u64(&memcg->memsw, RES_LIMIT);
3699 min_memsw_limit = min(min_memsw_limit, tmp);
3700 }
3701out:
3702 *mem_limit = min_limit;
3703 *memsw_limit = min_memsw_limit;
3704 return;
3705}
3706
Pavel Emelyanov29f2a4d2008-04-29 01:00:21 -07003707static int mem_cgroup_reset(struct cgroup *cont, unsigned int event)
Pavel Emelyanovc84872e2008-04-29 01:00:17 -07003708{
3709 struct mem_cgroup *mem;
KAMEZAWA Hiroyuki8c7c6e342009-01-07 18:08:00 -08003710 int type, name;
Pavel Emelyanovc84872e2008-04-29 01:00:17 -07003711
3712 mem = mem_cgroup_from_cont(cont);
KAMEZAWA Hiroyuki8c7c6e342009-01-07 18:08:00 -08003713 type = MEMFILE_TYPE(event);
3714 name = MEMFILE_ATTR(event);
3715 switch (name) {
Pavel Emelyanov29f2a4d2008-04-29 01:00:21 -07003716 case RES_MAX_USAGE:
KAMEZAWA Hiroyuki8c7c6e342009-01-07 18:08:00 -08003717 if (type == _MEM)
3718 res_counter_reset_max(&mem->res);
3719 else
3720 res_counter_reset_max(&mem->memsw);
Pavel Emelyanov29f2a4d2008-04-29 01:00:21 -07003721 break;
3722 case RES_FAILCNT:
KAMEZAWA Hiroyuki8c7c6e342009-01-07 18:08:00 -08003723 if (type == _MEM)
3724 res_counter_reset_failcnt(&mem->res);
3725 else
3726 res_counter_reset_failcnt(&mem->memsw);
Pavel Emelyanov29f2a4d2008-04-29 01:00:21 -07003727 break;
3728 }
Balbir Singhf64c3f52009-09-23 15:56:37 -07003729
Pavel Emelyanov85cc59d2008-04-29 01:00:20 -07003730 return 0;
Pavel Emelyanovc84872e2008-04-29 01:00:17 -07003731}
3732
Daisuke Nishimura7dc74be2010-03-10 15:22:13 -08003733static u64 mem_cgroup_move_charge_read(struct cgroup *cgrp,
3734 struct cftype *cft)
3735{
3736 return mem_cgroup_from_cont(cgrp)->move_charge_at_immigrate;
3737}
3738
Daisuke Nishimura02491442010-03-10 15:22:17 -08003739#ifdef CONFIG_MMU
Daisuke Nishimura7dc74be2010-03-10 15:22:13 -08003740static int mem_cgroup_move_charge_write(struct cgroup *cgrp,
3741 struct cftype *cft, u64 val)
3742{
3743 struct mem_cgroup *mem = mem_cgroup_from_cont(cgrp);
3744
3745 if (val >= (1 << NR_MOVE_TYPE))
3746 return -EINVAL;
3747 /*
3748 * We check this value several times in both in can_attach() and
3749 * attach(), so we need cgroup lock to prevent this value from being
3750 * inconsistent.
3751 */
3752 cgroup_lock();
3753 mem->move_charge_at_immigrate = val;
3754 cgroup_unlock();
3755
3756 return 0;
3757}
Daisuke Nishimura02491442010-03-10 15:22:17 -08003758#else
3759static int mem_cgroup_move_charge_write(struct cgroup *cgrp,
3760 struct cftype *cft, u64 val)
3761{
3762 return -ENOSYS;
3763}
3764#endif
Daisuke Nishimura7dc74be2010-03-10 15:22:13 -08003765
KAMEZAWA Hiroyuki14067bb2009-04-02 16:57:35 -07003766
3767/* For read statistics */
3768enum {
3769 MCS_CACHE,
3770 MCS_RSS,
KAMEZAWA Hiroyukid8046582009-12-15 16:47:09 -08003771 MCS_FILE_MAPPED,
KAMEZAWA Hiroyuki14067bb2009-04-02 16:57:35 -07003772 MCS_PGPGIN,
3773 MCS_PGPGOUT,
Daisuke Nishimura1dd3a272009-09-23 15:56:43 -07003774 MCS_SWAP,
KAMEZAWA Hiroyuki14067bb2009-04-02 16:57:35 -07003775 MCS_INACTIVE_ANON,
3776 MCS_ACTIVE_ANON,
3777 MCS_INACTIVE_FILE,
3778 MCS_ACTIVE_FILE,
3779 MCS_UNEVICTABLE,
3780 NR_MCS_STAT,
KAMEZAWA Hiroyukid2ceb9b2008-02-07 00:14:25 -08003781};
3782
KAMEZAWA Hiroyuki14067bb2009-04-02 16:57:35 -07003783struct mcs_total_stat {
3784 s64 stat[NR_MCS_STAT];
3785};
3786
3787struct {
3788 char *local_name;
3789 char *total_name;
3790} memcg_stat_strings[NR_MCS_STAT] = {
3791 {"cache", "total_cache"},
3792 {"rss", "total_rss"},
Balbir Singhd69b0422009-06-17 16:26:34 -07003793 {"mapped_file", "total_mapped_file"},
KAMEZAWA Hiroyuki14067bb2009-04-02 16:57:35 -07003794 {"pgpgin", "total_pgpgin"},
3795 {"pgpgout", "total_pgpgout"},
Daisuke Nishimura1dd3a272009-09-23 15:56:43 -07003796 {"swap", "total_swap"},
KAMEZAWA Hiroyuki14067bb2009-04-02 16:57:35 -07003797 {"inactive_anon", "total_inactive_anon"},
3798 {"active_anon", "total_active_anon"},
3799 {"inactive_file", "total_inactive_file"},
3800 {"active_file", "total_active_file"},
3801 {"unevictable", "total_unevictable"}
3802};
3803
3804
KAMEZAWA Hiroyuki7d74b062010-10-27 15:33:41 -07003805static void
3806mem_cgroup_get_local_stat(struct mem_cgroup *mem, struct mcs_total_stat *s)
KAMEZAWA Hiroyuki14067bb2009-04-02 16:57:35 -07003807{
KAMEZAWA Hiroyuki14067bb2009-04-02 16:57:35 -07003808 s64 val;
3809
3810 /* per cpu stat */
KAMEZAWA Hiroyukic62b1a32010-03-10 15:22:29 -08003811 val = mem_cgroup_read_stat(mem, MEM_CGROUP_STAT_CACHE);
KAMEZAWA Hiroyuki14067bb2009-04-02 16:57:35 -07003812 s->stat[MCS_CACHE] += val * PAGE_SIZE;
KAMEZAWA Hiroyukic62b1a32010-03-10 15:22:29 -08003813 val = mem_cgroup_read_stat(mem, MEM_CGROUP_STAT_RSS);
KAMEZAWA Hiroyuki14067bb2009-04-02 16:57:35 -07003814 s->stat[MCS_RSS] += val * PAGE_SIZE;
KAMEZAWA Hiroyukic62b1a32010-03-10 15:22:29 -08003815 val = mem_cgroup_read_stat(mem, MEM_CGROUP_STAT_FILE_MAPPED);
KAMEZAWA Hiroyukid8046582009-12-15 16:47:09 -08003816 s->stat[MCS_FILE_MAPPED] += val * PAGE_SIZE;
Johannes Weinere9f89742011-03-23 16:42:37 -07003817 val = mem_cgroup_read_events(mem, MEM_CGROUP_EVENTS_PGPGIN);
KAMEZAWA Hiroyuki14067bb2009-04-02 16:57:35 -07003818 s->stat[MCS_PGPGIN] += val;
Johannes Weinere9f89742011-03-23 16:42:37 -07003819 val = mem_cgroup_read_events(mem, MEM_CGROUP_EVENTS_PGPGOUT);
KAMEZAWA Hiroyuki14067bb2009-04-02 16:57:35 -07003820 s->stat[MCS_PGPGOUT] += val;
Daisuke Nishimura1dd3a272009-09-23 15:56:43 -07003821 if (do_swap_account) {
KAMEZAWA Hiroyukic62b1a32010-03-10 15:22:29 -08003822 val = mem_cgroup_read_stat(mem, MEM_CGROUP_STAT_SWAPOUT);
Daisuke Nishimura1dd3a272009-09-23 15:56:43 -07003823 s->stat[MCS_SWAP] += val * PAGE_SIZE;
3824 }
KAMEZAWA Hiroyuki14067bb2009-04-02 16:57:35 -07003825
3826 /* per zone stat */
3827 val = mem_cgroup_get_local_zonestat(mem, LRU_INACTIVE_ANON);
3828 s->stat[MCS_INACTIVE_ANON] += val * PAGE_SIZE;
3829 val = mem_cgroup_get_local_zonestat(mem, LRU_ACTIVE_ANON);
3830 s->stat[MCS_ACTIVE_ANON] += val * PAGE_SIZE;
3831 val = mem_cgroup_get_local_zonestat(mem, LRU_INACTIVE_FILE);
3832 s->stat[MCS_INACTIVE_FILE] += val * PAGE_SIZE;
3833 val = mem_cgroup_get_local_zonestat(mem, LRU_ACTIVE_FILE);
3834 s->stat[MCS_ACTIVE_FILE] += val * PAGE_SIZE;
3835 val = mem_cgroup_get_local_zonestat(mem, LRU_UNEVICTABLE);
3836 s->stat[MCS_UNEVICTABLE] += val * PAGE_SIZE;
KAMEZAWA Hiroyuki14067bb2009-04-02 16:57:35 -07003837}
3838
3839static void
3840mem_cgroup_get_total_stat(struct mem_cgroup *mem, struct mcs_total_stat *s)
3841{
KAMEZAWA Hiroyuki7d74b062010-10-27 15:33:41 -07003842 struct mem_cgroup *iter;
3843
3844 for_each_mem_cgroup_tree(iter, mem)
3845 mem_cgroup_get_local_stat(iter, s);
KAMEZAWA Hiroyuki14067bb2009-04-02 16:57:35 -07003846}
3847
Paul Menagec64745c2008-04-29 01:00:02 -07003848static int mem_control_stat_show(struct cgroup *cont, struct cftype *cft,
3849 struct cgroup_map_cb *cb)
KAMEZAWA Hiroyukid2ceb9b2008-02-07 00:14:25 -08003850{
KAMEZAWA Hiroyukid2ceb9b2008-02-07 00:14:25 -08003851 struct mem_cgroup *mem_cont = mem_cgroup_from_cont(cont);
KAMEZAWA Hiroyuki14067bb2009-04-02 16:57:35 -07003852 struct mcs_total_stat mystat;
KAMEZAWA Hiroyukid2ceb9b2008-02-07 00:14:25 -08003853 int i;
3854
KAMEZAWA Hiroyuki14067bb2009-04-02 16:57:35 -07003855 memset(&mystat, 0, sizeof(mystat));
3856 mem_cgroup_get_local_stat(mem_cont, &mystat);
KAMEZAWA Hiroyukid2ceb9b2008-02-07 00:14:25 -08003857
Daisuke Nishimura1dd3a272009-09-23 15:56:43 -07003858 for (i = 0; i < NR_MCS_STAT; i++) {
3859 if (i == MCS_SWAP && !do_swap_account)
3860 continue;
KAMEZAWA Hiroyuki14067bb2009-04-02 16:57:35 -07003861 cb->fill(cb, memcg_stat_strings[i].local_name, mystat.stat[i]);
Daisuke Nishimura1dd3a272009-09-23 15:56:43 -07003862 }
KAMEZAWA Hiroyuki6d12e2d2008-02-07 00:14:31 -08003863
KAMEZAWA Hiroyuki14067bb2009-04-02 16:57:35 -07003864 /* Hierarchical information */
KAMEZAWA Hiroyukifee7b542009-01-07 18:08:26 -08003865 {
3866 unsigned long long limit, memsw_limit;
3867 memcg_get_hierarchical_limit(mem_cont, &limit, &memsw_limit);
3868 cb->fill(cb, "hierarchical_memory_limit", limit);
3869 if (do_swap_account)
3870 cb->fill(cb, "hierarchical_memsw_limit", memsw_limit);
3871 }
KOSAKI Motohiro7f016ee2009-01-07 18:08:22 -08003872
KAMEZAWA Hiroyuki14067bb2009-04-02 16:57:35 -07003873 memset(&mystat, 0, sizeof(mystat));
3874 mem_cgroup_get_total_stat(mem_cont, &mystat);
Daisuke Nishimura1dd3a272009-09-23 15:56:43 -07003875 for (i = 0; i < NR_MCS_STAT; i++) {
3876 if (i == MCS_SWAP && !do_swap_account)
3877 continue;
KAMEZAWA Hiroyuki14067bb2009-04-02 16:57:35 -07003878 cb->fill(cb, memcg_stat_strings[i].total_name, mystat.stat[i]);
Daisuke Nishimura1dd3a272009-09-23 15:56:43 -07003879 }
KAMEZAWA Hiroyuki14067bb2009-04-02 16:57:35 -07003880
KOSAKI Motohiro7f016ee2009-01-07 18:08:22 -08003881#ifdef CONFIG_DEBUG_VM
KOSAKI Motohiroc772be92009-01-07 18:08:25 -08003882 cb->fill(cb, "inactive_ratio", calc_inactive_ratio(mem_cont, NULL));
KOSAKI Motohiro7f016ee2009-01-07 18:08:22 -08003883
3884 {
3885 int nid, zid;
3886 struct mem_cgroup_per_zone *mz;
3887 unsigned long recent_rotated[2] = {0, 0};
3888 unsigned long recent_scanned[2] = {0, 0};
3889
3890 for_each_online_node(nid)
3891 for (zid = 0; zid < MAX_NR_ZONES; zid++) {
3892 mz = mem_cgroup_zoneinfo(mem_cont, nid, zid);
3893
3894 recent_rotated[0] +=
3895 mz->reclaim_stat.recent_rotated[0];
3896 recent_rotated[1] +=
3897 mz->reclaim_stat.recent_rotated[1];
3898 recent_scanned[0] +=
3899 mz->reclaim_stat.recent_scanned[0];
3900 recent_scanned[1] +=
3901 mz->reclaim_stat.recent_scanned[1];
3902 }
3903 cb->fill(cb, "recent_rotated_anon", recent_rotated[0]);
3904 cb->fill(cb, "recent_rotated_file", recent_rotated[1]);
3905 cb->fill(cb, "recent_scanned_anon", recent_scanned[0]);
3906 cb->fill(cb, "recent_scanned_file", recent_scanned[1]);
3907 }
3908#endif
3909
KAMEZAWA Hiroyukid2ceb9b2008-02-07 00:14:25 -08003910 return 0;
3911}
3912
KOSAKI Motohiroa7885eb2009-01-07 18:08:24 -08003913static u64 mem_cgroup_swappiness_read(struct cgroup *cgrp, struct cftype *cft)
3914{
3915 struct mem_cgroup *memcg = mem_cgroup_from_cont(cgrp);
3916
3917 return get_swappiness(memcg);
3918}
3919
3920static int mem_cgroup_swappiness_write(struct cgroup *cgrp, struct cftype *cft,
3921 u64 val)
3922{
3923 struct mem_cgroup *memcg = mem_cgroup_from_cont(cgrp);
3924 struct mem_cgroup *parent;
Li Zefan068b38c2009-01-15 13:51:26 -08003925
KOSAKI Motohiroa7885eb2009-01-07 18:08:24 -08003926 if (val > 100)
3927 return -EINVAL;
3928
3929 if (cgrp->parent == NULL)
3930 return -EINVAL;
3931
3932 parent = mem_cgroup_from_cont(cgrp->parent);
Li Zefan068b38c2009-01-15 13:51:26 -08003933
3934 cgroup_lock();
3935
KOSAKI Motohiroa7885eb2009-01-07 18:08:24 -08003936 /* If under hierarchy, only empty-root can set this value */
3937 if ((parent->use_hierarchy) ||
Li Zefan068b38c2009-01-15 13:51:26 -08003938 (memcg->use_hierarchy && !list_empty(&cgrp->children))) {
3939 cgroup_unlock();
KOSAKI Motohiroa7885eb2009-01-07 18:08:24 -08003940 return -EINVAL;
Li Zefan068b38c2009-01-15 13:51:26 -08003941 }
KOSAKI Motohiroa7885eb2009-01-07 18:08:24 -08003942
KOSAKI Motohiroa7885eb2009-01-07 18:08:24 -08003943 memcg->swappiness = val;
KOSAKI Motohiroa7885eb2009-01-07 18:08:24 -08003944
Li Zefan068b38c2009-01-15 13:51:26 -08003945 cgroup_unlock();
3946
KOSAKI Motohiroa7885eb2009-01-07 18:08:24 -08003947 return 0;
3948}
3949
Kirill A. Shutemov2e72b632010-03-10 15:22:24 -08003950static void __mem_cgroup_threshold(struct mem_cgroup *memcg, bool swap)
3951{
3952 struct mem_cgroup_threshold_ary *t;
3953 u64 usage;
3954 int i;
3955
3956 rcu_read_lock();
3957 if (!swap)
Kirill A. Shutemov2c488db2010-05-26 14:42:47 -07003958 t = rcu_dereference(memcg->thresholds.primary);
Kirill A. Shutemov2e72b632010-03-10 15:22:24 -08003959 else
Kirill A. Shutemov2c488db2010-05-26 14:42:47 -07003960 t = rcu_dereference(memcg->memsw_thresholds.primary);
Kirill A. Shutemov2e72b632010-03-10 15:22:24 -08003961
3962 if (!t)
3963 goto unlock;
3964
3965 usage = mem_cgroup_usage(memcg, swap);
3966
3967 /*
3968 * current_threshold points to threshold just below usage.
3969 * If it's not true, a threshold was crossed after last
3970 * call of __mem_cgroup_threshold().
3971 */
Phil Carmody5407a562010-05-26 14:42:42 -07003972 i = t->current_threshold;
Kirill A. Shutemov2e72b632010-03-10 15:22:24 -08003973
3974 /*
3975 * Iterate backward over array of thresholds starting from
3976 * current_threshold and check if a threshold is crossed.
3977 * If none of thresholds below usage is crossed, we read
3978 * only one element of the array here.
3979 */
3980 for (; i >= 0 && unlikely(t->entries[i].threshold > usage); i--)
3981 eventfd_signal(t->entries[i].eventfd, 1);
3982
3983 /* i = current_threshold + 1 */
3984 i++;
3985
3986 /*
3987 * Iterate forward over array of thresholds starting from
3988 * current_threshold+1 and check if a threshold is crossed.
3989 * If none of thresholds above usage is crossed, we read
3990 * only one element of the array here.
3991 */
3992 for (; i < t->size && unlikely(t->entries[i].threshold <= usage); i++)
3993 eventfd_signal(t->entries[i].eventfd, 1);
3994
3995 /* Update current_threshold */
Phil Carmody5407a562010-05-26 14:42:42 -07003996 t->current_threshold = i - 1;
Kirill A. Shutemov2e72b632010-03-10 15:22:24 -08003997unlock:
3998 rcu_read_unlock();
3999}
4000
4001static void mem_cgroup_threshold(struct mem_cgroup *memcg)
4002{
Kirill A. Shutemovad4ca5f2010-10-07 12:59:27 -07004003 while (memcg) {
4004 __mem_cgroup_threshold(memcg, false);
4005 if (do_swap_account)
4006 __mem_cgroup_threshold(memcg, true);
4007
4008 memcg = parent_mem_cgroup(memcg);
4009 }
Kirill A. Shutemov2e72b632010-03-10 15:22:24 -08004010}
4011
4012static int compare_thresholds(const void *a, const void *b)
4013{
4014 const struct mem_cgroup_threshold *_a = a;
4015 const struct mem_cgroup_threshold *_b = b;
4016
4017 return _a->threshold - _b->threshold;
4018}
4019
KAMEZAWA Hiroyuki7d74b062010-10-27 15:33:41 -07004020static int mem_cgroup_oom_notify_cb(struct mem_cgroup *mem)
KAMEZAWA Hiroyuki9490ff22010-05-26 14:42:36 -07004021{
4022 struct mem_cgroup_eventfd_list *ev;
4023
4024 list_for_each_entry(ev, &mem->oom_notify, list)
4025 eventfd_signal(ev->eventfd, 1);
4026 return 0;
4027}
4028
4029static void mem_cgroup_oom_notify(struct mem_cgroup *mem)
4030{
KAMEZAWA Hiroyuki7d74b062010-10-27 15:33:41 -07004031 struct mem_cgroup *iter;
4032
4033 for_each_mem_cgroup_tree(iter, mem)
4034 mem_cgroup_oom_notify_cb(iter);
KAMEZAWA Hiroyuki9490ff22010-05-26 14:42:36 -07004035}
4036
4037static int mem_cgroup_usage_register_event(struct cgroup *cgrp,
4038 struct cftype *cft, struct eventfd_ctx *eventfd, const char *args)
Kirill A. Shutemov2e72b632010-03-10 15:22:24 -08004039{
4040 struct mem_cgroup *memcg = mem_cgroup_from_cont(cgrp);
Kirill A. Shutemov2c488db2010-05-26 14:42:47 -07004041 struct mem_cgroup_thresholds *thresholds;
4042 struct mem_cgroup_threshold_ary *new;
Kirill A. Shutemov2e72b632010-03-10 15:22:24 -08004043 int type = MEMFILE_TYPE(cft->private);
4044 u64 threshold, usage;
Kirill A. Shutemov2c488db2010-05-26 14:42:47 -07004045 int i, size, ret;
Kirill A. Shutemov2e72b632010-03-10 15:22:24 -08004046
4047 ret = res_counter_memparse_write_strategy(args, &threshold);
4048 if (ret)
4049 return ret;
4050
4051 mutex_lock(&memcg->thresholds_lock);
Kirill A. Shutemov2c488db2010-05-26 14:42:47 -07004052
Kirill A. Shutemov2e72b632010-03-10 15:22:24 -08004053 if (type == _MEM)
Kirill A. Shutemov2c488db2010-05-26 14:42:47 -07004054 thresholds = &memcg->thresholds;
Kirill A. Shutemov2e72b632010-03-10 15:22:24 -08004055 else if (type == _MEMSWAP)
Kirill A. Shutemov2c488db2010-05-26 14:42:47 -07004056 thresholds = &memcg->memsw_thresholds;
Kirill A. Shutemov2e72b632010-03-10 15:22:24 -08004057 else
4058 BUG();
4059
4060 usage = mem_cgroup_usage(memcg, type == _MEMSWAP);
4061
4062 /* Check if a threshold crossed before adding a new one */
Kirill A. Shutemov2c488db2010-05-26 14:42:47 -07004063 if (thresholds->primary)
Kirill A. Shutemov2e72b632010-03-10 15:22:24 -08004064 __mem_cgroup_threshold(memcg, type == _MEMSWAP);
4065
Kirill A. Shutemov2c488db2010-05-26 14:42:47 -07004066 size = thresholds->primary ? thresholds->primary->size + 1 : 1;
Kirill A. Shutemov2e72b632010-03-10 15:22:24 -08004067
4068 /* Allocate memory for new array of thresholds */
Kirill A. Shutemov2c488db2010-05-26 14:42:47 -07004069 new = kmalloc(sizeof(*new) + size * sizeof(struct mem_cgroup_threshold),
Kirill A. Shutemov2e72b632010-03-10 15:22:24 -08004070 GFP_KERNEL);
Kirill A. Shutemov2c488db2010-05-26 14:42:47 -07004071 if (!new) {
Kirill A. Shutemov2e72b632010-03-10 15:22:24 -08004072 ret = -ENOMEM;
4073 goto unlock;
4074 }
Kirill A. Shutemov2c488db2010-05-26 14:42:47 -07004075 new->size = size;
Kirill A. Shutemov2e72b632010-03-10 15:22:24 -08004076
4077 /* Copy thresholds (if any) to new array */
Kirill A. Shutemov2c488db2010-05-26 14:42:47 -07004078 if (thresholds->primary) {
4079 memcpy(new->entries, thresholds->primary->entries, (size - 1) *
Kirill A. Shutemov2e72b632010-03-10 15:22:24 -08004080 sizeof(struct mem_cgroup_threshold));
Kirill A. Shutemov2c488db2010-05-26 14:42:47 -07004081 }
4082
Kirill A. Shutemov2e72b632010-03-10 15:22:24 -08004083 /* Add new threshold */
Kirill A. Shutemov2c488db2010-05-26 14:42:47 -07004084 new->entries[size - 1].eventfd = eventfd;
4085 new->entries[size - 1].threshold = threshold;
Kirill A. Shutemov2e72b632010-03-10 15:22:24 -08004086
4087 /* Sort thresholds. Registering of new threshold isn't time-critical */
Kirill A. Shutemov2c488db2010-05-26 14:42:47 -07004088 sort(new->entries, size, sizeof(struct mem_cgroup_threshold),
Kirill A. Shutemov2e72b632010-03-10 15:22:24 -08004089 compare_thresholds, NULL);
4090
4091 /* Find current threshold */
Kirill A. Shutemov2c488db2010-05-26 14:42:47 -07004092 new->current_threshold = -1;
Kirill A. Shutemov2e72b632010-03-10 15:22:24 -08004093 for (i = 0; i < size; i++) {
Kirill A. Shutemov2c488db2010-05-26 14:42:47 -07004094 if (new->entries[i].threshold < usage) {
Kirill A. Shutemov2e72b632010-03-10 15:22:24 -08004095 /*
Kirill A. Shutemov2c488db2010-05-26 14:42:47 -07004096 * new->current_threshold will not be used until
4097 * rcu_assign_pointer(), so it's safe to increment
Kirill A. Shutemov2e72b632010-03-10 15:22:24 -08004098 * it here.
4099 */
Kirill A. Shutemov2c488db2010-05-26 14:42:47 -07004100 ++new->current_threshold;
Kirill A. Shutemov2e72b632010-03-10 15:22:24 -08004101 }
4102 }
4103
Kirill A. Shutemov2c488db2010-05-26 14:42:47 -07004104 /* Free old spare buffer and save old primary buffer as spare */
4105 kfree(thresholds->spare);
4106 thresholds->spare = thresholds->primary;
4107
4108 rcu_assign_pointer(thresholds->primary, new);
Kirill A. Shutemov2e72b632010-03-10 15:22:24 -08004109
Kirill A. Shutemov907860e2010-05-26 14:42:46 -07004110 /* To be sure that nobody uses thresholds */
Kirill A. Shutemov2e72b632010-03-10 15:22:24 -08004111 synchronize_rcu();
4112
Kirill A. Shutemov2e72b632010-03-10 15:22:24 -08004113unlock:
4114 mutex_unlock(&memcg->thresholds_lock);
4115
4116 return ret;
4117}
4118
Kirill A. Shutemov907860e2010-05-26 14:42:46 -07004119static void mem_cgroup_usage_unregister_event(struct cgroup *cgrp,
KAMEZAWA Hiroyuki9490ff22010-05-26 14:42:36 -07004120 struct cftype *cft, struct eventfd_ctx *eventfd)
Kirill A. Shutemov2e72b632010-03-10 15:22:24 -08004121{
4122 struct mem_cgroup *memcg = mem_cgroup_from_cont(cgrp);
Kirill A. Shutemov2c488db2010-05-26 14:42:47 -07004123 struct mem_cgroup_thresholds *thresholds;
4124 struct mem_cgroup_threshold_ary *new;
Kirill A. Shutemov2e72b632010-03-10 15:22:24 -08004125 int type = MEMFILE_TYPE(cft->private);
4126 u64 usage;
Kirill A. Shutemov2c488db2010-05-26 14:42:47 -07004127 int i, j, size;
Kirill A. Shutemov2e72b632010-03-10 15:22:24 -08004128
4129 mutex_lock(&memcg->thresholds_lock);
4130 if (type == _MEM)
Kirill A. Shutemov2c488db2010-05-26 14:42:47 -07004131 thresholds = &memcg->thresholds;
Kirill A. Shutemov2e72b632010-03-10 15:22:24 -08004132 else if (type == _MEMSWAP)
Kirill A. Shutemov2c488db2010-05-26 14:42:47 -07004133 thresholds = &memcg->memsw_thresholds;
Kirill A. Shutemov2e72b632010-03-10 15:22:24 -08004134 else
4135 BUG();
4136
4137 /*
4138 * Something went wrong if we trying to unregister a threshold
4139 * if we don't have thresholds
4140 */
4141 BUG_ON(!thresholds);
4142
4143 usage = mem_cgroup_usage(memcg, type == _MEMSWAP);
4144
4145 /* Check if a threshold crossed before removing */
4146 __mem_cgroup_threshold(memcg, type == _MEMSWAP);
4147
4148 /* Calculate new number of threshold */
Kirill A. Shutemov2c488db2010-05-26 14:42:47 -07004149 size = 0;
4150 for (i = 0; i < thresholds->primary->size; i++) {
4151 if (thresholds->primary->entries[i].eventfd != eventfd)
Kirill A. Shutemov2e72b632010-03-10 15:22:24 -08004152 size++;
4153 }
4154
Kirill A. Shutemov2c488db2010-05-26 14:42:47 -07004155 new = thresholds->spare;
Kirill A. Shutemov907860e2010-05-26 14:42:46 -07004156
Kirill A. Shutemov2e72b632010-03-10 15:22:24 -08004157 /* Set thresholds array to NULL if we don't have thresholds */
4158 if (!size) {
Kirill A. Shutemov2c488db2010-05-26 14:42:47 -07004159 kfree(new);
4160 new = NULL;
Kirill A. Shutemov907860e2010-05-26 14:42:46 -07004161 goto swap_buffers;
Kirill A. Shutemov2e72b632010-03-10 15:22:24 -08004162 }
4163
Kirill A. Shutemov2c488db2010-05-26 14:42:47 -07004164 new->size = size;
Kirill A. Shutemov2e72b632010-03-10 15:22:24 -08004165
4166 /* Copy thresholds and find current threshold */
Kirill A. Shutemov2c488db2010-05-26 14:42:47 -07004167 new->current_threshold = -1;
4168 for (i = 0, j = 0; i < thresholds->primary->size; i++) {
4169 if (thresholds->primary->entries[i].eventfd == eventfd)
Kirill A. Shutemov2e72b632010-03-10 15:22:24 -08004170 continue;
4171
Kirill A. Shutemov2c488db2010-05-26 14:42:47 -07004172 new->entries[j] = thresholds->primary->entries[i];
4173 if (new->entries[j].threshold < usage) {
Kirill A. Shutemov2e72b632010-03-10 15:22:24 -08004174 /*
Kirill A. Shutemov2c488db2010-05-26 14:42:47 -07004175 * new->current_threshold will not be used
Kirill A. Shutemov2e72b632010-03-10 15:22:24 -08004176 * until rcu_assign_pointer(), so it's safe to increment
4177 * it here.
4178 */
Kirill A. Shutemov2c488db2010-05-26 14:42:47 -07004179 ++new->current_threshold;
Kirill A. Shutemov2e72b632010-03-10 15:22:24 -08004180 }
4181 j++;
4182 }
4183
Kirill A. Shutemov907860e2010-05-26 14:42:46 -07004184swap_buffers:
Kirill A. Shutemov2c488db2010-05-26 14:42:47 -07004185 /* Swap primary and spare array */
4186 thresholds->spare = thresholds->primary;
4187 rcu_assign_pointer(thresholds->primary, new);
Kirill A. Shutemov2e72b632010-03-10 15:22:24 -08004188
Kirill A. Shutemov907860e2010-05-26 14:42:46 -07004189 /* To be sure that nobody uses thresholds */
Kirill A. Shutemov2e72b632010-03-10 15:22:24 -08004190 synchronize_rcu();
4191
Kirill A. Shutemov2e72b632010-03-10 15:22:24 -08004192 mutex_unlock(&memcg->thresholds_lock);
Kirill A. Shutemov2e72b632010-03-10 15:22:24 -08004193}
KAMEZAWA Hiroyukic1e862c2009-01-07 18:07:55 -08004194
KAMEZAWA Hiroyuki9490ff22010-05-26 14:42:36 -07004195static int mem_cgroup_oom_register_event(struct cgroup *cgrp,
4196 struct cftype *cft, struct eventfd_ctx *eventfd, const char *args)
4197{
4198 struct mem_cgroup *memcg = mem_cgroup_from_cont(cgrp);
4199 struct mem_cgroup_eventfd_list *event;
4200 int type = MEMFILE_TYPE(cft->private);
4201
4202 BUG_ON(type != _OOM_TYPE);
4203 event = kmalloc(sizeof(*event), GFP_KERNEL);
4204 if (!event)
4205 return -ENOMEM;
4206
4207 mutex_lock(&memcg_oom_mutex);
4208
4209 event->eventfd = eventfd;
4210 list_add(&event->list, &memcg->oom_notify);
4211
4212 /* already in OOM ? */
4213 if (atomic_read(&memcg->oom_lock))
4214 eventfd_signal(eventfd, 1);
4215 mutex_unlock(&memcg_oom_mutex);
4216
4217 return 0;
4218}
4219
Kirill A. Shutemov907860e2010-05-26 14:42:46 -07004220static void mem_cgroup_oom_unregister_event(struct cgroup *cgrp,
KAMEZAWA Hiroyuki9490ff22010-05-26 14:42:36 -07004221 struct cftype *cft, struct eventfd_ctx *eventfd)
4222{
4223 struct mem_cgroup *mem = mem_cgroup_from_cont(cgrp);
4224 struct mem_cgroup_eventfd_list *ev, *tmp;
4225 int type = MEMFILE_TYPE(cft->private);
4226
4227 BUG_ON(type != _OOM_TYPE);
4228
4229 mutex_lock(&memcg_oom_mutex);
4230
4231 list_for_each_entry_safe(ev, tmp, &mem->oom_notify, list) {
4232 if (ev->eventfd == eventfd) {
4233 list_del(&ev->list);
4234 kfree(ev);
4235 }
4236 }
4237
4238 mutex_unlock(&memcg_oom_mutex);
KAMEZAWA Hiroyuki9490ff22010-05-26 14:42:36 -07004239}
4240
KAMEZAWA Hiroyuki3c11ecf2010-05-26 14:42:37 -07004241static int mem_cgroup_oom_control_read(struct cgroup *cgrp,
4242 struct cftype *cft, struct cgroup_map_cb *cb)
4243{
4244 struct mem_cgroup *mem = mem_cgroup_from_cont(cgrp);
4245
4246 cb->fill(cb, "oom_kill_disable", mem->oom_kill_disable);
4247
4248 if (atomic_read(&mem->oom_lock))
4249 cb->fill(cb, "under_oom", 1);
4250 else
4251 cb->fill(cb, "under_oom", 0);
4252 return 0;
4253}
4254
KAMEZAWA Hiroyuki3c11ecf2010-05-26 14:42:37 -07004255static int mem_cgroup_oom_control_write(struct cgroup *cgrp,
4256 struct cftype *cft, u64 val)
4257{
4258 struct mem_cgroup *mem = mem_cgroup_from_cont(cgrp);
4259 struct mem_cgroup *parent;
4260
4261 /* cannot set to root cgroup and only 0 and 1 are allowed */
4262 if (!cgrp->parent || !((val == 0) || (val == 1)))
4263 return -EINVAL;
4264
4265 parent = mem_cgroup_from_cont(cgrp->parent);
4266
4267 cgroup_lock();
4268 /* oom-kill-disable is a flag for subhierarchy. */
4269 if ((parent->use_hierarchy) ||
4270 (mem->use_hierarchy && !list_empty(&cgrp->children))) {
4271 cgroup_unlock();
4272 return -EINVAL;
4273 }
4274 mem->oom_kill_disable = val;
KAMEZAWA Hiroyuki4d845eb2010-06-29 15:05:18 -07004275 if (!val)
4276 memcg_oom_recover(mem);
KAMEZAWA Hiroyuki3c11ecf2010-05-26 14:42:37 -07004277 cgroup_unlock();
4278 return 0;
4279}
4280
Balbir Singh8cdea7c2008-02-07 00:13:50 -08004281static struct cftype mem_cgroup_files[] = {
4282 {
Balbir Singh0eea1032008-02-07 00:13:57 -08004283 .name = "usage_in_bytes",
KAMEZAWA Hiroyuki8c7c6e342009-01-07 18:08:00 -08004284 .private = MEMFILE_PRIVATE(_MEM, RES_USAGE),
Paul Menage2c3daa72008-04-29 00:59:58 -07004285 .read_u64 = mem_cgroup_read,
KAMEZAWA Hiroyuki9490ff22010-05-26 14:42:36 -07004286 .register_event = mem_cgroup_usage_register_event,
4287 .unregister_event = mem_cgroup_usage_unregister_event,
Balbir Singh8cdea7c2008-02-07 00:13:50 -08004288 },
4289 {
Pavel Emelyanovc84872e2008-04-29 01:00:17 -07004290 .name = "max_usage_in_bytes",
KAMEZAWA Hiroyuki8c7c6e342009-01-07 18:08:00 -08004291 .private = MEMFILE_PRIVATE(_MEM, RES_MAX_USAGE),
Pavel Emelyanov29f2a4d2008-04-29 01:00:21 -07004292 .trigger = mem_cgroup_reset,
Pavel Emelyanovc84872e2008-04-29 01:00:17 -07004293 .read_u64 = mem_cgroup_read,
4294 },
4295 {
Balbir Singh0eea1032008-02-07 00:13:57 -08004296 .name = "limit_in_bytes",
KAMEZAWA Hiroyuki8c7c6e342009-01-07 18:08:00 -08004297 .private = MEMFILE_PRIVATE(_MEM, RES_LIMIT),
Paul Menage856c13a2008-07-25 01:47:04 -07004298 .write_string = mem_cgroup_write,
Paul Menage2c3daa72008-04-29 00:59:58 -07004299 .read_u64 = mem_cgroup_read,
Balbir Singh8cdea7c2008-02-07 00:13:50 -08004300 },
4301 {
Balbir Singh296c81d2009-09-23 15:56:36 -07004302 .name = "soft_limit_in_bytes",
4303 .private = MEMFILE_PRIVATE(_MEM, RES_SOFT_LIMIT),
4304 .write_string = mem_cgroup_write,
4305 .read_u64 = mem_cgroup_read,
4306 },
4307 {
Balbir Singh8cdea7c2008-02-07 00:13:50 -08004308 .name = "failcnt",
KAMEZAWA Hiroyuki8c7c6e342009-01-07 18:08:00 -08004309 .private = MEMFILE_PRIVATE(_MEM, RES_FAILCNT),
Pavel Emelyanov29f2a4d2008-04-29 01:00:21 -07004310 .trigger = mem_cgroup_reset,
Paul Menage2c3daa72008-04-29 00:59:58 -07004311 .read_u64 = mem_cgroup_read,
Balbir Singh8cdea7c2008-02-07 00:13:50 -08004312 },
Balbir Singh8697d332008-02-07 00:13:59 -08004313 {
KAMEZAWA Hiroyukid2ceb9b2008-02-07 00:14:25 -08004314 .name = "stat",
Paul Menagec64745c2008-04-29 01:00:02 -07004315 .read_map = mem_control_stat_show,
KAMEZAWA Hiroyukid2ceb9b2008-02-07 00:14:25 -08004316 },
KAMEZAWA Hiroyukic1e862c2009-01-07 18:07:55 -08004317 {
4318 .name = "force_empty",
4319 .trigger = mem_cgroup_force_empty_write,
4320 },
Balbir Singh18f59ea2009-01-07 18:08:07 -08004321 {
4322 .name = "use_hierarchy",
4323 .write_u64 = mem_cgroup_hierarchy_write,
4324 .read_u64 = mem_cgroup_hierarchy_read,
4325 },
KOSAKI Motohiroa7885eb2009-01-07 18:08:24 -08004326 {
4327 .name = "swappiness",
4328 .read_u64 = mem_cgroup_swappiness_read,
4329 .write_u64 = mem_cgroup_swappiness_write,
4330 },
Daisuke Nishimura7dc74be2010-03-10 15:22:13 -08004331 {
4332 .name = "move_charge_at_immigrate",
4333 .read_u64 = mem_cgroup_move_charge_read,
4334 .write_u64 = mem_cgroup_move_charge_write,
4335 },
KAMEZAWA Hiroyuki9490ff22010-05-26 14:42:36 -07004336 {
4337 .name = "oom_control",
KAMEZAWA Hiroyuki3c11ecf2010-05-26 14:42:37 -07004338 .read_map = mem_cgroup_oom_control_read,
4339 .write_u64 = mem_cgroup_oom_control_write,
KAMEZAWA Hiroyuki9490ff22010-05-26 14:42:36 -07004340 .register_event = mem_cgroup_oom_register_event,
4341 .unregister_event = mem_cgroup_oom_unregister_event,
4342 .private = MEMFILE_PRIVATE(_OOM_TYPE, OOM_CONTROL),
4343 },
Balbir Singh8cdea7c2008-02-07 00:13:50 -08004344};
4345
KAMEZAWA Hiroyuki8c7c6e342009-01-07 18:08:00 -08004346#ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP
4347static struct cftype memsw_cgroup_files[] = {
4348 {
4349 .name = "memsw.usage_in_bytes",
4350 .private = MEMFILE_PRIVATE(_MEMSWAP, RES_USAGE),
4351 .read_u64 = mem_cgroup_read,
KAMEZAWA Hiroyuki9490ff22010-05-26 14:42:36 -07004352 .register_event = mem_cgroup_usage_register_event,
4353 .unregister_event = mem_cgroup_usage_unregister_event,
KAMEZAWA Hiroyuki8c7c6e342009-01-07 18:08:00 -08004354 },
4355 {
4356 .name = "memsw.max_usage_in_bytes",
4357 .private = MEMFILE_PRIVATE(_MEMSWAP, RES_MAX_USAGE),
4358 .trigger = mem_cgroup_reset,
4359 .read_u64 = mem_cgroup_read,
4360 },
4361 {
4362 .name = "memsw.limit_in_bytes",
4363 .private = MEMFILE_PRIVATE(_MEMSWAP, RES_LIMIT),
4364 .write_string = mem_cgroup_write,
4365 .read_u64 = mem_cgroup_read,
4366 },
4367 {
4368 .name = "memsw.failcnt",
4369 .private = MEMFILE_PRIVATE(_MEMSWAP, RES_FAILCNT),
4370 .trigger = mem_cgroup_reset,
4371 .read_u64 = mem_cgroup_read,
4372 },
4373};
4374
4375static int register_memsw_files(struct cgroup *cont, struct cgroup_subsys *ss)
4376{
4377 if (!do_swap_account)
4378 return 0;
4379 return cgroup_add_files(cont, ss, memsw_cgroup_files,
4380 ARRAY_SIZE(memsw_cgroup_files));
4381};
4382#else
4383static int register_memsw_files(struct cgroup *cont, struct cgroup_subsys *ss)
4384{
4385 return 0;
4386}
4387#endif
4388
KAMEZAWA Hiroyuki6d12e2d2008-02-07 00:14:31 -08004389static int alloc_mem_cgroup_per_zone_info(struct mem_cgroup *mem, int node)
4390{
4391 struct mem_cgroup_per_node *pn;
KAMEZAWA Hiroyuki1ecaab22008-02-07 00:14:38 -08004392 struct mem_cgroup_per_zone *mz;
Christoph Lameterb69408e2008-10-18 20:26:14 -07004393 enum lru_list l;
KAMEZAWA Hiroyuki41e33552008-04-08 17:41:54 -07004394 int zone, tmp = node;
KAMEZAWA Hiroyuki1ecaab22008-02-07 00:14:38 -08004395 /*
4396 * This routine is called against possible nodes.
4397 * But it's BUG to call kmalloc() against offline node.
4398 *
4399 * TODO: this routine can waste much memory for nodes which will
4400 * never be onlined. It's better to use memory hotplug callback
4401 * function.
4402 */
KAMEZAWA Hiroyuki41e33552008-04-08 17:41:54 -07004403 if (!node_state(node, N_NORMAL_MEMORY))
4404 tmp = -1;
Jesper Juhl17295c82011-01-13 15:47:42 -08004405 pn = kzalloc_node(sizeof(*pn), GFP_KERNEL, tmp);
KAMEZAWA Hiroyuki6d12e2d2008-02-07 00:14:31 -08004406 if (!pn)
4407 return 1;
KAMEZAWA Hiroyuki1ecaab22008-02-07 00:14:38 -08004408
KAMEZAWA Hiroyuki6d12e2d2008-02-07 00:14:31 -08004409 mem->info.nodeinfo[node] = pn;
KAMEZAWA Hiroyuki1ecaab22008-02-07 00:14:38 -08004410 for (zone = 0; zone < MAX_NR_ZONES; zone++) {
4411 mz = &pn->zoneinfo[zone];
Christoph Lameterb69408e2008-10-18 20:26:14 -07004412 for_each_lru(l)
4413 INIT_LIST_HEAD(&mz->lists[l]);
Balbir Singhf64c3f52009-09-23 15:56:37 -07004414 mz->usage_in_excess = 0;
Balbir Singh4e416952009-09-23 15:56:39 -07004415 mz->on_tree = false;
4416 mz->mem = mem;
KAMEZAWA Hiroyuki1ecaab22008-02-07 00:14:38 -08004417 }
KAMEZAWA Hiroyuki6d12e2d2008-02-07 00:14:31 -08004418 return 0;
4419}
4420
KAMEZAWA Hiroyuki1ecaab22008-02-07 00:14:38 -08004421static void free_mem_cgroup_per_zone_info(struct mem_cgroup *mem, int node)
4422{
4423 kfree(mem->info.nodeinfo[node]);
4424}
4425
KAMEZAWA Hiroyuki33327942008-04-29 01:00:24 -07004426static struct mem_cgroup *mem_cgroup_alloc(void)
4427{
4428 struct mem_cgroup *mem;
KAMEZAWA Hiroyukic62b1a32010-03-10 15:22:29 -08004429 int size = sizeof(struct mem_cgroup);
KAMEZAWA Hiroyuki33327942008-04-29 01:00:24 -07004430
KAMEZAWA Hiroyukic62b1a32010-03-10 15:22:29 -08004431 /* Can be very big if MAX_NUMNODES is very big */
Jan Blunckc8dad2b2009-01-07 18:07:53 -08004432 if (size < PAGE_SIZE)
Jesper Juhl17295c82011-01-13 15:47:42 -08004433 mem = kzalloc(size, GFP_KERNEL);
KAMEZAWA Hiroyuki33327942008-04-29 01:00:24 -07004434 else
Jesper Juhl17295c82011-01-13 15:47:42 -08004435 mem = vzalloc(size);
KAMEZAWA Hiroyuki33327942008-04-29 01:00:24 -07004436
Dan Carpentere7bbcdf2010-03-23 13:35:12 -07004437 if (!mem)
4438 return NULL;
4439
KAMEZAWA Hiroyukic62b1a32010-03-10 15:22:29 -08004440 mem->stat = alloc_percpu(struct mem_cgroup_stat_cpu);
Dan Carpenterd2e61b82010-11-11 14:05:12 -08004441 if (!mem->stat)
4442 goto out_free;
KAMEZAWA Hiroyuki711d3d22010-10-27 15:33:42 -07004443 spin_lock_init(&mem->pcp_counter_lock);
KAMEZAWA Hiroyuki33327942008-04-29 01:00:24 -07004444 return mem;
Dan Carpenterd2e61b82010-11-11 14:05:12 -08004445
4446out_free:
4447 if (size < PAGE_SIZE)
4448 kfree(mem);
4449 else
4450 vfree(mem);
4451 return NULL;
KAMEZAWA Hiroyuki33327942008-04-29 01:00:24 -07004452}
4453
KAMEZAWA Hiroyuki8c7c6e342009-01-07 18:08:00 -08004454/*
4455 * At destroying mem_cgroup, references from swap_cgroup can remain.
4456 * (scanning all at force_empty is too costly...)
4457 *
4458 * Instead of clearing all references at force_empty, we remember
4459 * the number of reference from swap_cgroup and free mem_cgroup when
4460 * it goes down to 0.
4461 *
KAMEZAWA Hiroyuki8c7c6e342009-01-07 18:08:00 -08004462 * Removal of cgroup itself succeeds regardless of refs from swap.
4463 */
4464
KAMEZAWA Hiroyukia7ba0ee2009-01-07 18:08:32 -08004465static void __mem_cgroup_free(struct mem_cgroup *mem)
KAMEZAWA Hiroyuki33327942008-04-29 01:00:24 -07004466{
KAMEZAWA Hiroyuki08e552c2009-01-07 18:08:01 -08004467 int node;
4468
Balbir Singhf64c3f52009-09-23 15:56:37 -07004469 mem_cgroup_remove_from_trees(mem);
KAMEZAWA Hiroyuki04046e12009-04-02 16:57:33 -07004470 free_css_id(&mem_cgroup_subsys, &mem->css);
4471
KAMEZAWA Hiroyuki08e552c2009-01-07 18:08:01 -08004472 for_each_node_state(node, N_POSSIBLE)
4473 free_mem_cgroup_per_zone_info(mem, node);
4474
KAMEZAWA Hiroyukic62b1a32010-03-10 15:22:29 -08004475 free_percpu(mem->stat);
4476 if (sizeof(struct mem_cgroup) < PAGE_SIZE)
KAMEZAWA Hiroyuki33327942008-04-29 01:00:24 -07004477 kfree(mem);
4478 else
4479 vfree(mem);
4480}
4481
KAMEZAWA Hiroyuki8c7c6e342009-01-07 18:08:00 -08004482static void mem_cgroup_get(struct mem_cgroup *mem)
4483{
4484 atomic_inc(&mem->refcnt);
4485}
4486
Daisuke Nishimura483c30b2010-03-10 15:22:18 -08004487static void __mem_cgroup_put(struct mem_cgroup *mem, int count)
KAMEZAWA Hiroyuki8c7c6e342009-01-07 18:08:00 -08004488{
Daisuke Nishimura483c30b2010-03-10 15:22:18 -08004489 if (atomic_sub_and_test(count, &mem->refcnt)) {
Daisuke Nishimura7bcc1bb2009-01-29 14:25:11 -08004490 struct mem_cgroup *parent = parent_mem_cgroup(mem);
KAMEZAWA Hiroyukia7ba0ee2009-01-07 18:08:32 -08004491 __mem_cgroup_free(mem);
Daisuke Nishimura7bcc1bb2009-01-29 14:25:11 -08004492 if (parent)
4493 mem_cgroup_put(parent);
4494 }
KAMEZAWA Hiroyuki8c7c6e342009-01-07 18:08:00 -08004495}
4496
Daisuke Nishimura483c30b2010-03-10 15:22:18 -08004497static void mem_cgroup_put(struct mem_cgroup *mem)
4498{
4499 __mem_cgroup_put(mem, 1);
4500}
4501
Daisuke Nishimura7bcc1bb2009-01-29 14:25:11 -08004502/*
4503 * Returns the parent mem_cgroup in memcgroup hierarchy with hierarchy enabled.
4504 */
4505static struct mem_cgroup *parent_mem_cgroup(struct mem_cgroup *mem)
4506{
4507 if (!mem->res.parent)
4508 return NULL;
4509 return mem_cgroup_from_res_counter(mem->res.parent, res);
4510}
KAMEZAWA Hiroyuki33327942008-04-29 01:00:24 -07004511
KAMEZAWA Hiroyukic0777192009-01-07 18:07:57 -08004512#ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP
4513static void __init enable_swap_cgroup(void)
4514{
Hirokazu Takahashif8d665422009-01-07 18:08:02 -08004515 if (!mem_cgroup_disabled() && really_do_swap_account)
KAMEZAWA Hiroyukic0777192009-01-07 18:07:57 -08004516 do_swap_account = 1;
4517}
4518#else
4519static void __init enable_swap_cgroup(void)
4520{
4521}
4522#endif
4523
Balbir Singhf64c3f52009-09-23 15:56:37 -07004524static int mem_cgroup_soft_limit_tree_init(void)
4525{
4526 struct mem_cgroup_tree_per_node *rtpn;
4527 struct mem_cgroup_tree_per_zone *rtpz;
4528 int tmp, node, zone;
4529
4530 for_each_node_state(node, N_POSSIBLE) {
4531 tmp = node;
4532 if (!node_state(node, N_NORMAL_MEMORY))
4533 tmp = -1;
4534 rtpn = kzalloc_node(sizeof(*rtpn), GFP_KERNEL, tmp);
4535 if (!rtpn)
4536 return 1;
4537
4538 soft_limit_tree.rb_tree_per_node[node] = rtpn;
4539
4540 for (zone = 0; zone < MAX_NR_ZONES; zone++) {
4541 rtpz = &rtpn->rb_tree_per_zone[zone];
4542 rtpz->rb_root = RB_ROOT;
4543 spin_lock_init(&rtpz->lock);
4544 }
4545 }
4546 return 0;
4547}
4548
Li Zefan0eb253e2009-01-15 13:51:25 -08004549static struct cgroup_subsys_state * __ref
Balbir Singh8cdea7c2008-02-07 00:13:50 -08004550mem_cgroup_create(struct cgroup_subsys *ss, struct cgroup *cont)
4551{
Balbir Singh28dbc4b2009-01-07 18:08:05 -08004552 struct mem_cgroup *mem, *parent;
KAMEZAWA Hiroyuki04046e12009-04-02 16:57:33 -07004553 long error = -ENOMEM;
KAMEZAWA Hiroyuki6d12e2d2008-02-07 00:14:31 -08004554 int node;
Balbir Singh8cdea7c2008-02-07 00:13:50 -08004555
Jan Blunckc8dad2b2009-01-07 18:07:53 -08004556 mem = mem_cgroup_alloc();
4557 if (!mem)
KAMEZAWA Hiroyuki04046e12009-04-02 16:57:33 -07004558 return ERR_PTR(error);
Pavel Emelianov78fb7462008-02-07 00:13:51 -08004559
KAMEZAWA Hiroyuki6d12e2d2008-02-07 00:14:31 -08004560 for_each_node_state(node, N_POSSIBLE)
4561 if (alloc_mem_cgroup_per_zone_info(mem, node))
4562 goto free_out;
Balbir Singhf64c3f52009-09-23 15:56:37 -07004563
KAMEZAWA Hiroyukic0777192009-01-07 18:07:57 -08004564 /* root ? */
Balbir Singh28dbc4b2009-01-07 18:08:05 -08004565 if (cont->parent == NULL) {
KAMEZAWA Hiroyukicdec2e42009-12-15 16:47:08 -08004566 int cpu;
KAMEZAWA Hiroyukic0777192009-01-07 18:07:57 -08004567 enable_swap_cgroup();
Balbir Singh28dbc4b2009-01-07 18:08:05 -08004568 parent = NULL;
Balbir Singh4b3bde42009-09-23 15:56:32 -07004569 root_mem_cgroup = mem;
Balbir Singhf64c3f52009-09-23 15:56:37 -07004570 if (mem_cgroup_soft_limit_tree_init())
4571 goto free_out;
KAMEZAWA Hiroyukicdec2e42009-12-15 16:47:08 -08004572 for_each_possible_cpu(cpu) {
4573 struct memcg_stock_pcp *stock =
4574 &per_cpu(memcg_stock, cpu);
4575 INIT_WORK(&stock->work, drain_local_stock);
4576 }
KAMEZAWA Hiroyuki711d3d22010-10-27 15:33:42 -07004577 hotcpu_notifier(memcg_cpu_hotplug_callback, 0);
Balbir Singh18f59ea2009-01-07 18:08:07 -08004578 } else {
Balbir Singh28dbc4b2009-01-07 18:08:05 -08004579 parent = mem_cgroup_from_cont(cont->parent);
Balbir Singh18f59ea2009-01-07 18:08:07 -08004580 mem->use_hierarchy = parent->use_hierarchy;
KAMEZAWA Hiroyuki3c11ecf2010-05-26 14:42:37 -07004581 mem->oom_kill_disable = parent->oom_kill_disable;
Balbir Singh18f59ea2009-01-07 18:08:07 -08004582 }
Balbir Singh28dbc4b2009-01-07 18:08:05 -08004583
Balbir Singh18f59ea2009-01-07 18:08:07 -08004584 if (parent && parent->use_hierarchy) {
4585 res_counter_init(&mem->res, &parent->res);
4586 res_counter_init(&mem->memsw, &parent->memsw);
Daisuke Nishimura7bcc1bb2009-01-29 14:25:11 -08004587 /*
4588 * We increment refcnt of the parent to ensure that we can
4589 * safely access it on res_counter_charge/uncharge.
4590 * This refcnt will be decremented when freeing this
4591 * mem_cgroup(see mem_cgroup_put).
4592 */
4593 mem_cgroup_get(parent);
Balbir Singh18f59ea2009-01-07 18:08:07 -08004594 } else {
4595 res_counter_init(&mem->res, NULL);
4596 res_counter_init(&mem->memsw, NULL);
4597 }
KAMEZAWA Hiroyuki04046e12009-04-02 16:57:33 -07004598 mem->last_scanned_child = 0;
KAMEZAWA Hiroyuki9490ff22010-05-26 14:42:36 -07004599 INIT_LIST_HEAD(&mem->oom_notify);
Balbir Singh6d61ef42009-01-07 18:08:06 -08004600
KOSAKI Motohiroa7885eb2009-01-07 18:08:24 -08004601 if (parent)
4602 mem->swappiness = get_swappiness(parent);
KAMEZAWA Hiroyukia7ba0ee2009-01-07 18:08:32 -08004603 atomic_set(&mem->refcnt, 1);
Daisuke Nishimura7dc74be2010-03-10 15:22:13 -08004604 mem->move_charge_at_immigrate = 0;
Kirill A. Shutemov2e72b632010-03-10 15:22:24 -08004605 mutex_init(&mem->thresholds_lock);
Balbir Singh8cdea7c2008-02-07 00:13:50 -08004606 return &mem->css;
KAMEZAWA Hiroyuki6d12e2d2008-02-07 00:14:31 -08004607free_out:
KAMEZAWA Hiroyukia7ba0ee2009-01-07 18:08:32 -08004608 __mem_cgroup_free(mem);
Balbir Singh4b3bde42009-09-23 15:56:32 -07004609 root_mem_cgroup = NULL;
KAMEZAWA Hiroyuki04046e12009-04-02 16:57:33 -07004610 return ERR_PTR(error);
Balbir Singh8cdea7c2008-02-07 00:13:50 -08004611}
4612
KAMEZAWA Hiroyukiec64f512009-04-02 16:57:26 -07004613static int mem_cgroup_pre_destroy(struct cgroup_subsys *ss,
KAMEZAWA Hiroyukidf878fb2008-02-07 00:14:28 -08004614 struct cgroup *cont)
4615{
4616 struct mem_cgroup *mem = mem_cgroup_from_cont(cont);
KAMEZAWA Hiroyukiec64f512009-04-02 16:57:26 -07004617
4618 return mem_cgroup_force_empty(mem, false);
KAMEZAWA Hiroyukidf878fb2008-02-07 00:14:28 -08004619}
4620
Balbir Singh8cdea7c2008-02-07 00:13:50 -08004621static void mem_cgroup_destroy(struct cgroup_subsys *ss,
4622 struct cgroup *cont)
4623{
Daisuke Nishimurac268e992009-01-15 13:51:13 -08004624 struct mem_cgroup *mem = mem_cgroup_from_cont(cont);
Daisuke Nishimurac268e992009-01-15 13:51:13 -08004625
Daisuke Nishimurac268e992009-01-15 13:51:13 -08004626 mem_cgroup_put(mem);
Balbir Singh8cdea7c2008-02-07 00:13:50 -08004627}
4628
4629static int mem_cgroup_populate(struct cgroup_subsys *ss,
4630 struct cgroup *cont)
4631{
KAMEZAWA Hiroyuki8c7c6e342009-01-07 18:08:00 -08004632 int ret;
4633
4634 ret = cgroup_add_files(cont, ss, mem_cgroup_files,
4635 ARRAY_SIZE(mem_cgroup_files));
4636
4637 if (!ret)
4638 ret = register_memsw_files(cont, ss);
4639 return ret;
Balbir Singh8cdea7c2008-02-07 00:13:50 -08004640}
4641
Daisuke Nishimura02491442010-03-10 15:22:17 -08004642#ifdef CONFIG_MMU
Daisuke Nishimura7dc74be2010-03-10 15:22:13 -08004643/* Handlers for move charge at task migration. */
Daisuke Nishimura854ffa82010-03-10 15:22:15 -08004644#define PRECHARGE_COUNT_AT_ONCE 256
4645static int mem_cgroup_do_precharge(unsigned long count)
Daisuke Nishimura7dc74be2010-03-10 15:22:13 -08004646{
Daisuke Nishimura854ffa82010-03-10 15:22:15 -08004647 int ret = 0;
4648 int batch_count = PRECHARGE_COUNT_AT_ONCE;
Daisuke Nishimura4ffef5f2010-03-10 15:22:14 -08004649 struct mem_cgroup *mem = mc.to;
4650
Daisuke Nishimura854ffa82010-03-10 15:22:15 -08004651 if (mem_cgroup_is_root(mem)) {
4652 mc.precharge += count;
4653 /* we don't need css_get for root */
4654 return ret;
4655 }
4656 /* try to charge at once */
4657 if (count > 1) {
4658 struct res_counter *dummy;
4659 /*
4660 * "mem" cannot be under rmdir() because we've already checked
4661 * by cgroup_lock_live_cgroup() that it is not removed and we
4662 * are still under the same cgroup_mutex. So we can postpone
4663 * css_get().
4664 */
4665 if (res_counter_charge(&mem->res, PAGE_SIZE * count, &dummy))
4666 goto one_by_one;
4667 if (do_swap_account && res_counter_charge(&mem->memsw,
4668 PAGE_SIZE * count, &dummy)) {
4669 res_counter_uncharge(&mem->res, PAGE_SIZE * count);
4670 goto one_by_one;
4671 }
4672 mc.precharge += count;
Daisuke Nishimura854ffa82010-03-10 15:22:15 -08004673 return ret;
4674 }
4675one_by_one:
4676 /* fall back to one by one charge */
4677 while (count--) {
4678 if (signal_pending(current)) {
4679 ret = -EINTR;
4680 break;
4681 }
4682 if (!batch_count--) {
4683 batch_count = PRECHARGE_COUNT_AT_ONCE;
4684 cond_resched();
4685 }
Johannes Weiner7ec99d62011-03-23 16:42:36 -07004686 ret = __mem_cgroup_try_charge(NULL, GFP_KERNEL, 1, &mem, false);
Daisuke Nishimura854ffa82010-03-10 15:22:15 -08004687 if (ret || !mem)
4688 /* mem_cgroup_clear_mc() will do uncharge later */
4689 return -ENOMEM;
4690 mc.precharge++;
4691 }
Daisuke Nishimura4ffef5f2010-03-10 15:22:14 -08004692 return ret;
4693}
4694
4695/**
4696 * is_target_pte_for_mc - check a pte whether it is valid for move charge
4697 * @vma: the vma the pte to be checked belongs
4698 * @addr: the address corresponding to the pte to be checked
4699 * @ptent: the pte to be checked
Daisuke Nishimura02491442010-03-10 15:22:17 -08004700 * @target: the pointer the target page or swap ent will be stored(can be NULL)
Daisuke Nishimura4ffef5f2010-03-10 15:22:14 -08004701 *
4702 * Returns
4703 * 0(MC_TARGET_NONE): if the pte is not a target for move charge.
4704 * 1(MC_TARGET_PAGE): if the page corresponding to this pte is a target for
4705 * move charge. if @target is not NULL, the page is stored in target->page
4706 * with extra refcnt got(Callers should handle it).
Daisuke Nishimura02491442010-03-10 15:22:17 -08004707 * 2(MC_TARGET_SWAP): if the swap entry corresponding to this pte is a
4708 * target for charge migration. if @target is not NULL, the entry is stored
4709 * in target->ent.
Daisuke Nishimura4ffef5f2010-03-10 15:22:14 -08004710 *
4711 * Called with pte lock held.
4712 */
Daisuke Nishimura4ffef5f2010-03-10 15:22:14 -08004713union mc_target {
4714 struct page *page;
Daisuke Nishimura02491442010-03-10 15:22:17 -08004715 swp_entry_t ent;
Daisuke Nishimura4ffef5f2010-03-10 15:22:14 -08004716};
4717
Daisuke Nishimura4ffef5f2010-03-10 15:22:14 -08004718enum mc_target_type {
4719 MC_TARGET_NONE, /* not used */
4720 MC_TARGET_PAGE,
Daisuke Nishimura02491442010-03-10 15:22:17 -08004721 MC_TARGET_SWAP,
Daisuke Nishimura4ffef5f2010-03-10 15:22:14 -08004722};
4723
Daisuke Nishimura90254a62010-05-26 14:42:38 -07004724static struct page *mc_handle_present_pte(struct vm_area_struct *vma,
4725 unsigned long addr, pte_t ptent)
4726{
4727 struct page *page = vm_normal_page(vma, addr, ptent);
4728
4729 if (!page || !page_mapped(page))
4730 return NULL;
4731 if (PageAnon(page)) {
4732 /* we don't move shared anon */
4733 if (!move_anon() || page_mapcount(page) > 2)
4734 return NULL;
Daisuke Nishimura87946a72010-05-26 14:42:39 -07004735 } else if (!move_file())
4736 /* we ignore mapcount for file pages */
Daisuke Nishimura90254a62010-05-26 14:42:38 -07004737 return NULL;
4738 if (!get_page_unless_zero(page))
4739 return NULL;
4740
4741 return page;
4742}
4743
4744static struct page *mc_handle_swap_pte(struct vm_area_struct *vma,
4745 unsigned long addr, pte_t ptent, swp_entry_t *entry)
4746{
4747 int usage_count;
4748 struct page *page = NULL;
4749 swp_entry_t ent = pte_to_swp_entry(ptent);
4750
4751 if (!move_anon() || non_swap_entry(ent))
4752 return NULL;
4753 usage_count = mem_cgroup_count_swap_user(ent, &page);
4754 if (usage_count > 1) { /* we don't move shared anon */
4755 if (page)
4756 put_page(page);
4757 return NULL;
4758 }
4759 if (do_swap_account)
4760 entry->val = ent.val;
4761
4762 return page;
4763}
4764
Daisuke Nishimura87946a72010-05-26 14:42:39 -07004765static struct page *mc_handle_file_pte(struct vm_area_struct *vma,
4766 unsigned long addr, pte_t ptent, swp_entry_t *entry)
4767{
4768 struct page *page = NULL;
4769 struct inode *inode;
4770 struct address_space *mapping;
4771 pgoff_t pgoff;
4772
4773 if (!vma->vm_file) /* anonymous vma */
4774 return NULL;
4775 if (!move_file())
4776 return NULL;
4777
4778 inode = vma->vm_file->f_path.dentry->d_inode;
4779 mapping = vma->vm_file->f_mapping;
4780 if (pte_none(ptent))
4781 pgoff = linear_page_index(vma, addr);
4782 else /* pte_file(ptent) is true */
4783 pgoff = pte_to_pgoff(ptent);
4784
4785 /* page is moved even if it's not RSS of this task(page-faulted). */
4786 if (!mapping_cap_swap_backed(mapping)) { /* normal file */
4787 page = find_get_page(mapping, pgoff);
4788 } else { /* shmem/tmpfs file. we should take account of swap too. */
4789 swp_entry_t ent;
4790 mem_cgroup_get_shmem_target(inode, pgoff, &page, &ent);
4791 if (do_swap_account)
4792 entry->val = ent.val;
4793 }
4794
4795 return page;
4796}
4797
Daisuke Nishimura4ffef5f2010-03-10 15:22:14 -08004798static int is_target_pte_for_mc(struct vm_area_struct *vma,
4799 unsigned long addr, pte_t ptent, union mc_target *target)
4800{
Daisuke Nishimura02491442010-03-10 15:22:17 -08004801 struct page *page = NULL;
Daisuke Nishimura4ffef5f2010-03-10 15:22:14 -08004802 struct page_cgroup *pc;
4803 int ret = 0;
Daisuke Nishimura02491442010-03-10 15:22:17 -08004804 swp_entry_t ent = { .val = 0 };
Daisuke Nishimura4ffef5f2010-03-10 15:22:14 -08004805
Daisuke Nishimura90254a62010-05-26 14:42:38 -07004806 if (pte_present(ptent))
4807 page = mc_handle_present_pte(vma, addr, ptent);
4808 else if (is_swap_pte(ptent))
4809 page = mc_handle_swap_pte(vma, addr, ptent, &ent);
Daisuke Nishimura87946a72010-05-26 14:42:39 -07004810 else if (pte_none(ptent) || pte_file(ptent))
4811 page = mc_handle_file_pte(vma, addr, ptent, &ent);
Daisuke Nishimura90254a62010-05-26 14:42:38 -07004812
4813 if (!page && !ent.val)
Daisuke Nishimura02491442010-03-10 15:22:17 -08004814 return 0;
Daisuke Nishimura02491442010-03-10 15:22:17 -08004815 if (page) {
4816 pc = lookup_page_cgroup(page);
4817 /*
4818 * Do only loose check w/o page_cgroup lock.
4819 * mem_cgroup_move_account() checks the pc is valid or not under
4820 * the lock.
4821 */
4822 if (PageCgroupUsed(pc) && pc->mem_cgroup == mc.from) {
4823 ret = MC_TARGET_PAGE;
4824 if (target)
4825 target->page = page;
4826 }
4827 if (!ret || !target)
4828 put_page(page);
4829 }
Daisuke Nishimura90254a62010-05-26 14:42:38 -07004830 /* There is a swap entry and a page doesn't exist or isn't charged */
4831 if (ent.val && !ret &&
KAMEZAWA Hiroyuki7f0f1542010-05-11 14:06:58 -07004832 css_id(&mc.from->css) == lookup_swap_cgroup(ent)) {
4833 ret = MC_TARGET_SWAP;
4834 if (target)
4835 target->ent = ent;
Daisuke Nishimura02491442010-03-10 15:22:17 -08004836 }
Daisuke Nishimura4ffef5f2010-03-10 15:22:14 -08004837 return ret;
4838}
4839
4840static int mem_cgroup_count_precharge_pte_range(pmd_t *pmd,
4841 unsigned long addr, unsigned long end,
4842 struct mm_walk *walk)
4843{
4844 struct vm_area_struct *vma = walk->private;
4845 pte_t *pte;
4846 spinlock_t *ptl;
4847
Dave Hansen03319322011-03-22 16:32:56 -07004848 split_huge_page_pmd(walk->mm, pmd);
4849
Daisuke Nishimura4ffef5f2010-03-10 15:22:14 -08004850 pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl);
4851 for (; addr != end; pte++, addr += PAGE_SIZE)
4852 if (is_target_pte_for_mc(vma, addr, *pte, NULL))
4853 mc.precharge++; /* increment precharge temporarily */
4854 pte_unmap_unlock(pte - 1, ptl);
4855 cond_resched();
4856
Daisuke Nishimura7dc74be2010-03-10 15:22:13 -08004857 return 0;
4858}
4859
Daisuke Nishimura4ffef5f2010-03-10 15:22:14 -08004860static unsigned long mem_cgroup_count_precharge(struct mm_struct *mm)
4861{
4862 unsigned long precharge;
4863 struct vm_area_struct *vma;
4864
Daisuke Nishimuradfe076b2011-01-13 15:47:41 -08004865 down_read(&mm->mmap_sem);
Daisuke Nishimura4ffef5f2010-03-10 15:22:14 -08004866 for (vma = mm->mmap; vma; vma = vma->vm_next) {
4867 struct mm_walk mem_cgroup_count_precharge_walk = {
4868 .pmd_entry = mem_cgroup_count_precharge_pte_range,
4869 .mm = mm,
4870 .private = vma,
4871 };
4872 if (is_vm_hugetlb_page(vma))
4873 continue;
Daisuke Nishimura4ffef5f2010-03-10 15:22:14 -08004874 walk_page_range(vma->vm_start, vma->vm_end,
4875 &mem_cgroup_count_precharge_walk);
4876 }
Daisuke Nishimuradfe076b2011-01-13 15:47:41 -08004877 up_read(&mm->mmap_sem);
Daisuke Nishimura4ffef5f2010-03-10 15:22:14 -08004878
4879 precharge = mc.precharge;
4880 mc.precharge = 0;
4881
4882 return precharge;
4883}
4884
Daisuke Nishimura4ffef5f2010-03-10 15:22:14 -08004885static int mem_cgroup_precharge_mc(struct mm_struct *mm)
4886{
Daisuke Nishimuradfe076b2011-01-13 15:47:41 -08004887 unsigned long precharge = mem_cgroup_count_precharge(mm);
4888
4889 VM_BUG_ON(mc.moving_task);
4890 mc.moving_task = current;
4891 return mem_cgroup_do_precharge(precharge);
Daisuke Nishimura4ffef5f2010-03-10 15:22:14 -08004892}
4893
Daisuke Nishimuradfe076b2011-01-13 15:47:41 -08004894/* cancels all extra charges on mc.from and mc.to, and wakes up all waiters. */
4895static void __mem_cgroup_clear_mc(void)
Daisuke Nishimura4ffef5f2010-03-10 15:22:14 -08004896{
KAMEZAWA Hiroyuki2bd9bb22010-08-10 18:02:58 -07004897 struct mem_cgroup *from = mc.from;
4898 struct mem_cgroup *to = mc.to;
4899
Daisuke Nishimura4ffef5f2010-03-10 15:22:14 -08004900 /* we must uncharge all the leftover precharges from mc.to */
Daisuke Nishimura854ffa82010-03-10 15:22:15 -08004901 if (mc.precharge) {
4902 __mem_cgroup_cancel_charge(mc.to, mc.precharge);
4903 mc.precharge = 0;
4904 }
4905 /*
4906 * we didn't uncharge from mc.from at mem_cgroup_move_account(), so
4907 * we must uncharge here.
4908 */
4909 if (mc.moved_charge) {
4910 __mem_cgroup_cancel_charge(mc.from, mc.moved_charge);
4911 mc.moved_charge = 0;
Daisuke Nishimura4ffef5f2010-03-10 15:22:14 -08004912 }
Daisuke Nishimura483c30b2010-03-10 15:22:18 -08004913 /* we must fixup refcnts and charges */
4914 if (mc.moved_swap) {
Daisuke Nishimura483c30b2010-03-10 15:22:18 -08004915 /* uncharge swap account from the old cgroup */
4916 if (!mem_cgroup_is_root(mc.from))
4917 res_counter_uncharge(&mc.from->memsw,
4918 PAGE_SIZE * mc.moved_swap);
4919 __mem_cgroup_put(mc.from, mc.moved_swap);
4920
4921 if (!mem_cgroup_is_root(mc.to)) {
4922 /*
4923 * we charged both to->res and to->memsw, so we should
4924 * uncharge to->res.
4925 */
4926 res_counter_uncharge(&mc.to->res,
4927 PAGE_SIZE * mc.moved_swap);
Daisuke Nishimura483c30b2010-03-10 15:22:18 -08004928 }
4929 /* we've already done mem_cgroup_get(mc.to) */
Daisuke Nishimura483c30b2010-03-10 15:22:18 -08004930 mc.moved_swap = 0;
4931 }
Daisuke Nishimuradfe076b2011-01-13 15:47:41 -08004932 memcg_oom_recover(from);
4933 memcg_oom_recover(to);
4934 wake_up_all(&mc.waitq);
4935}
4936
4937static void mem_cgroup_clear_mc(void)
4938{
4939 struct mem_cgroup *from = mc.from;
4940
4941 /*
4942 * we must clear moving_task before waking up waiters at the end of
4943 * task migration.
4944 */
4945 mc.moving_task = NULL;
4946 __mem_cgroup_clear_mc();
KAMEZAWA Hiroyuki2bd9bb22010-08-10 18:02:58 -07004947 spin_lock(&mc.lock);
Daisuke Nishimura4ffef5f2010-03-10 15:22:14 -08004948 mc.from = NULL;
4949 mc.to = NULL;
KAMEZAWA Hiroyuki2bd9bb22010-08-10 18:02:58 -07004950 spin_unlock(&mc.lock);
KAMEZAWA Hiroyuki32047e22010-10-27 15:33:40 -07004951 mem_cgroup_end_move(from);
Daisuke Nishimura4ffef5f2010-03-10 15:22:14 -08004952}
4953
Daisuke Nishimura7dc74be2010-03-10 15:22:13 -08004954static int mem_cgroup_can_attach(struct cgroup_subsys *ss,
4955 struct cgroup *cgroup,
4956 struct task_struct *p,
4957 bool threadgroup)
4958{
4959 int ret = 0;
4960 struct mem_cgroup *mem = mem_cgroup_from_cont(cgroup);
4961
4962 if (mem->move_charge_at_immigrate) {
4963 struct mm_struct *mm;
4964 struct mem_cgroup *from = mem_cgroup_from_task(p);
4965
4966 VM_BUG_ON(from == mem);
4967
4968 mm = get_task_mm(p);
4969 if (!mm)
4970 return 0;
Daisuke Nishimura7dc74be2010-03-10 15:22:13 -08004971 /* We move charges only when we move a owner of the mm */
Daisuke Nishimura4ffef5f2010-03-10 15:22:14 -08004972 if (mm->owner == p) {
4973 VM_BUG_ON(mc.from);
4974 VM_BUG_ON(mc.to);
4975 VM_BUG_ON(mc.precharge);
Daisuke Nishimura854ffa82010-03-10 15:22:15 -08004976 VM_BUG_ON(mc.moved_charge);
Daisuke Nishimura483c30b2010-03-10 15:22:18 -08004977 VM_BUG_ON(mc.moved_swap);
KAMEZAWA Hiroyuki32047e22010-10-27 15:33:40 -07004978 mem_cgroup_start_move(from);
KAMEZAWA Hiroyuki2bd9bb22010-08-10 18:02:58 -07004979 spin_lock(&mc.lock);
Daisuke Nishimura4ffef5f2010-03-10 15:22:14 -08004980 mc.from = from;
4981 mc.to = mem;
KAMEZAWA Hiroyuki2bd9bb22010-08-10 18:02:58 -07004982 spin_unlock(&mc.lock);
Daisuke Nishimuradfe076b2011-01-13 15:47:41 -08004983 /* We set mc.moving_task later */
Daisuke Nishimura7dc74be2010-03-10 15:22:13 -08004984
Daisuke Nishimura4ffef5f2010-03-10 15:22:14 -08004985 ret = mem_cgroup_precharge_mc(mm);
4986 if (ret)
4987 mem_cgroup_clear_mc();
Daisuke Nishimuradfe076b2011-01-13 15:47:41 -08004988 }
4989 mmput(mm);
Daisuke Nishimura7dc74be2010-03-10 15:22:13 -08004990 }
4991 return ret;
4992}
4993
4994static void mem_cgroup_cancel_attach(struct cgroup_subsys *ss,
4995 struct cgroup *cgroup,
4996 struct task_struct *p,
4997 bool threadgroup)
4998{
Daisuke Nishimura4ffef5f2010-03-10 15:22:14 -08004999 mem_cgroup_clear_mc();
Daisuke Nishimura7dc74be2010-03-10 15:22:13 -08005000}
5001
Daisuke Nishimura4ffef5f2010-03-10 15:22:14 -08005002static int mem_cgroup_move_charge_pte_range(pmd_t *pmd,
5003 unsigned long addr, unsigned long end,
5004 struct mm_walk *walk)
Daisuke Nishimura7dc74be2010-03-10 15:22:13 -08005005{
Daisuke Nishimura4ffef5f2010-03-10 15:22:14 -08005006 int ret = 0;
5007 struct vm_area_struct *vma = walk->private;
5008 pte_t *pte;
5009 spinlock_t *ptl;
5010
Dave Hansen03319322011-03-22 16:32:56 -07005011 split_huge_page_pmd(walk->mm, pmd);
Daisuke Nishimura4ffef5f2010-03-10 15:22:14 -08005012retry:
5013 pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl);
5014 for (; addr != end; addr += PAGE_SIZE) {
5015 pte_t ptent = *(pte++);
5016 union mc_target target;
5017 int type;
5018 struct page *page;
5019 struct page_cgroup *pc;
Daisuke Nishimura02491442010-03-10 15:22:17 -08005020 swp_entry_t ent;
Daisuke Nishimura4ffef5f2010-03-10 15:22:14 -08005021
5022 if (!mc.precharge)
5023 break;
5024
5025 type = is_target_pte_for_mc(vma, addr, ptent, &target);
5026 switch (type) {
5027 case MC_TARGET_PAGE:
5028 page = target.page;
5029 if (isolate_lru_page(page))
5030 goto put;
5031 pc = lookup_page_cgroup(page);
Johannes Weiner7ec99d62011-03-23 16:42:36 -07005032 if (!mem_cgroup_move_account(page, 1, pc,
5033 mc.from, mc.to, false)) {
Daisuke Nishimura4ffef5f2010-03-10 15:22:14 -08005034 mc.precharge--;
Daisuke Nishimura854ffa82010-03-10 15:22:15 -08005035 /* we uncharge from mc.from later. */
5036 mc.moved_charge++;
Daisuke Nishimura4ffef5f2010-03-10 15:22:14 -08005037 }
5038 putback_lru_page(page);
5039put: /* is_target_pte_for_mc() gets the page */
5040 put_page(page);
5041 break;
Daisuke Nishimura02491442010-03-10 15:22:17 -08005042 case MC_TARGET_SWAP:
5043 ent = target.ent;
Daisuke Nishimura483c30b2010-03-10 15:22:18 -08005044 if (!mem_cgroup_move_swap_account(ent,
5045 mc.from, mc.to, false)) {
Daisuke Nishimura02491442010-03-10 15:22:17 -08005046 mc.precharge--;
Daisuke Nishimura483c30b2010-03-10 15:22:18 -08005047 /* we fixup refcnts and charges later. */
5048 mc.moved_swap++;
5049 }
Daisuke Nishimura02491442010-03-10 15:22:17 -08005050 break;
Daisuke Nishimura4ffef5f2010-03-10 15:22:14 -08005051 default:
5052 break;
5053 }
5054 }
5055 pte_unmap_unlock(pte - 1, ptl);
5056 cond_resched();
5057
5058 if (addr != end) {
5059 /*
5060 * We have consumed all precharges we got in can_attach().
5061 * We try charge one by one, but don't do any additional
5062 * charges to mc.to if we have failed in charge once in attach()
5063 * phase.
5064 */
Daisuke Nishimura854ffa82010-03-10 15:22:15 -08005065 ret = mem_cgroup_do_precharge(1);
Daisuke Nishimura4ffef5f2010-03-10 15:22:14 -08005066 if (!ret)
5067 goto retry;
5068 }
5069
5070 return ret;
5071}
5072
5073static void mem_cgroup_move_charge(struct mm_struct *mm)
5074{
5075 struct vm_area_struct *vma;
5076
5077 lru_add_drain_all();
Daisuke Nishimuradfe076b2011-01-13 15:47:41 -08005078retry:
5079 if (unlikely(!down_read_trylock(&mm->mmap_sem))) {
5080 /*
5081 * Someone who are holding the mmap_sem might be waiting in
5082 * waitq. So we cancel all extra charges, wake up all waiters,
5083 * and retry. Because we cancel precharges, we might not be able
5084 * to move enough charges, but moving charge is a best-effort
5085 * feature anyway, so it wouldn't be a big problem.
5086 */
5087 __mem_cgroup_clear_mc();
5088 cond_resched();
5089 goto retry;
5090 }
Daisuke Nishimura4ffef5f2010-03-10 15:22:14 -08005091 for (vma = mm->mmap; vma; vma = vma->vm_next) {
5092 int ret;
5093 struct mm_walk mem_cgroup_move_charge_walk = {
5094 .pmd_entry = mem_cgroup_move_charge_pte_range,
5095 .mm = mm,
5096 .private = vma,
5097 };
5098 if (is_vm_hugetlb_page(vma))
5099 continue;
Daisuke Nishimura4ffef5f2010-03-10 15:22:14 -08005100 ret = walk_page_range(vma->vm_start, vma->vm_end,
5101 &mem_cgroup_move_charge_walk);
5102 if (ret)
5103 /*
5104 * means we have consumed all precharges and failed in
5105 * doing additional charge. Just abandon here.
5106 */
5107 break;
5108 }
Daisuke Nishimuradfe076b2011-01-13 15:47:41 -08005109 up_read(&mm->mmap_sem);
Daisuke Nishimura7dc74be2010-03-10 15:22:13 -08005110}
5111
Balbir Singh67e465a2008-02-07 00:13:54 -08005112static void mem_cgroup_move_task(struct cgroup_subsys *ss,
5113 struct cgroup *cont,
5114 struct cgroup *old_cont,
Ben Blumbe367d02009-09-23 15:56:31 -07005115 struct task_struct *p,
5116 bool threadgroup)
Balbir Singh67e465a2008-02-07 00:13:54 -08005117{
Daisuke Nishimuradfe076b2011-01-13 15:47:41 -08005118 struct mm_struct *mm;
5119
5120 if (!mc.to)
Daisuke Nishimura4ffef5f2010-03-10 15:22:14 -08005121 /* no need to move charge */
5122 return;
5123
Daisuke Nishimuradfe076b2011-01-13 15:47:41 -08005124 mm = get_task_mm(p);
5125 if (mm) {
5126 mem_cgroup_move_charge(mm);
5127 mmput(mm);
5128 }
Daisuke Nishimura4ffef5f2010-03-10 15:22:14 -08005129 mem_cgroup_clear_mc();
Balbir Singh67e465a2008-02-07 00:13:54 -08005130}
Daisuke Nishimura5cfb80a2010-03-23 13:35:11 -07005131#else /* !CONFIG_MMU */
5132static int mem_cgroup_can_attach(struct cgroup_subsys *ss,
5133 struct cgroup *cgroup,
5134 struct task_struct *p,
5135 bool threadgroup)
5136{
5137 return 0;
5138}
5139static void mem_cgroup_cancel_attach(struct cgroup_subsys *ss,
5140 struct cgroup *cgroup,
5141 struct task_struct *p,
5142 bool threadgroup)
5143{
5144}
5145static void mem_cgroup_move_task(struct cgroup_subsys *ss,
5146 struct cgroup *cont,
5147 struct cgroup *old_cont,
5148 struct task_struct *p,
5149 bool threadgroup)
5150{
5151}
5152#endif
Balbir Singh67e465a2008-02-07 00:13:54 -08005153
Balbir Singh8cdea7c2008-02-07 00:13:50 -08005154struct cgroup_subsys mem_cgroup_subsys = {
5155 .name = "memory",
5156 .subsys_id = mem_cgroup_subsys_id,
5157 .create = mem_cgroup_create,
KAMEZAWA Hiroyukidf878fb2008-02-07 00:14:28 -08005158 .pre_destroy = mem_cgroup_pre_destroy,
Balbir Singh8cdea7c2008-02-07 00:13:50 -08005159 .destroy = mem_cgroup_destroy,
5160 .populate = mem_cgroup_populate,
Daisuke Nishimura7dc74be2010-03-10 15:22:13 -08005161 .can_attach = mem_cgroup_can_attach,
5162 .cancel_attach = mem_cgroup_cancel_attach,
Balbir Singh67e465a2008-02-07 00:13:54 -08005163 .attach = mem_cgroup_move_task,
KAMEZAWA Hiroyuki6d12e2d2008-02-07 00:14:31 -08005164 .early_init = 0,
KAMEZAWA Hiroyuki04046e12009-04-02 16:57:33 -07005165 .use_id = 1,
Balbir Singh8cdea7c2008-02-07 00:13:50 -08005166};
KAMEZAWA Hiroyukic0777192009-01-07 18:07:57 -08005167
5168#ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP
Michal Hockoa42c3902010-11-24 12:57:08 -08005169static int __init enable_swap_account(char *s)
5170{
5171 /* consider enabled if no parameter or 1 is given */
Michal Hockofceda1b2011-02-01 15:52:30 -08005172 if (!(*s) || !strcmp(s, "=1"))
Michal Hockoa42c3902010-11-24 12:57:08 -08005173 really_do_swap_account = 1;
Michal Hockofceda1b2011-02-01 15:52:30 -08005174 else if (!strcmp(s, "=0"))
Michal Hockoa42c3902010-11-24 12:57:08 -08005175 really_do_swap_account = 0;
5176 return 1;
5177}
5178__setup("swapaccount", enable_swap_account);
KAMEZAWA Hiroyukic0777192009-01-07 18:07:57 -08005179
5180static int __init disable_swap_account(char *s)
5181{
Michal Hocko552b3722011-02-01 15:52:31 -08005182 printk_once("noswapaccount is deprecated and will be removed in 2.6.40. Use swapaccount=0 instead\n");
Michal Hockofceda1b2011-02-01 15:52:30 -08005183 enable_swap_account("=0");
KAMEZAWA Hiroyukic0777192009-01-07 18:07:57 -08005184 return 1;
5185}
5186__setup("noswapaccount", disable_swap_account);
5187#endif