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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 Hiroyuki8c7c6e32009-01-07 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
KAMEZAWA Hiroyukid2265e62010-03-10 15:22:31 -080076/*
77 * Per memcg event counter is incremented at every pagein/pageout. This counter
78 * is used for trigger some periodic events. This is straightforward and better
79 * than using jiffies etc. to handle periodic memcg event.
80 *
81 * These values will be used as !((event) & ((1 <<(thresh)) - 1))
82 */
83#define THRESHOLDS_EVENTS_THRESH (7) /* once in 128 */
84#define SOFTLIMIT_EVENTS_THRESH (10) /* once in 1024 */
KAMEZAWA Hiroyukic0777192009-01-07 18:07:57 -080085
Balbir Singh8cdea7c2008-02-07 00:13:50 -080086/*
KAMEZAWA Hiroyukid52aa412008-02-07 00:14:24 -080087 * Statistics for memory cgroup.
88 */
89enum mem_cgroup_stat_index {
90 /*
91 * For MEM_CONTAINER_TYPE_ALL, usage = pagecache + rss.
92 */
93 MEM_CGROUP_STAT_CACHE, /* # of pages charged as cache */
Balbir Singhd69b0422009-06-17 16:26:34 -070094 MEM_CGROUP_STAT_RSS, /* # of pages charged as anon rss */
KAMEZAWA Hiroyukid8046582009-12-15 16:47:09 -080095 MEM_CGROUP_STAT_FILE_MAPPED, /* # of pages charged as file rss */
Balaji Rao55e462b2008-05-01 04:35:12 -070096 MEM_CGROUP_STAT_PGPGIN_COUNT, /* # of pages paged in */
97 MEM_CGROUP_STAT_PGPGOUT_COUNT, /* # of pages paged out */
Balbir Singh0c3e73e2009-09-23 15:56:42 -070098 MEM_CGROUP_STAT_SWAPOUT, /* # of pages, swapped out */
KAMEZAWA Hiroyuki711d3d22010-10-27 15:33:42 -070099 MEM_CGROUP_STAT_DATA, /* end of data requires synchronization */
100 /* incremented at every pagein/pageout */
101 MEM_CGROUP_EVENTS = MEM_CGROUP_STAT_DATA,
KAMEZAWA Hiroyuki32047e22010-10-27 15:33:40 -0700102 MEM_CGROUP_ON_MOVE, /* someone is moving account between groups */
KAMEZAWA Hiroyukid52aa412008-02-07 00:14:24 -0800103
104 MEM_CGROUP_STAT_NSTATS,
105};
106
107struct mem_cgroup_stat_cpu {
108 s64 count[MEM_CGROUP_STAT_NSTATS];
KAMEZAWA Hiroyukid52aa412008-02-07 00:14:24 -0800109};
110
KAMEZAWA Hiroyukid52aa412008-02-07 00:14:24 -0800111/*
KAMEZAWA Hiroyuki6d12e2d2008-02-07 00:14:31 -0800112 * per-zone information in memory controller.
113 */
KAMEZAWA Hiroyuki6d12e2d2008-02-07 00:14:31 -0800114struct mem_cgroup_per_zone {
KAMEZAWA Hiroyuki072c56c2008-02-07 00:14:39 -0800115 /*
116 * spin_lock to protect the per cgroup LRU
117 */
Christoph Lameterb69408e2008-10-18 20:26:14 -0700118 struct list_head lists[NR_LRU_LISTS];
119 unsigned long count[NR_LRU_LISTS];
KOSAKI Motohiro3e2f41f2009-01-07 18:08:20 -0800120
121 struct zone_reclaim_stat reclaim_stat;
Balbir Singhf64c3f52009-09-23 15:56:37 -0700122 struct rb_node tree_node; /* RB tree node */
123 unsigned long long usage_in_excess;/* Set to the value by which */
124 /* the soft limit is exceeded*/
125 bool on_tree;
Balbir Singh4e416952009-09-23 15:56:39 -0700126 struct mem_cgroup *mem; /* Back pointer, we cannot */
127 /* use container_of */
KAMEZAWA Hiroyuki6d12e2d2008-02-07 00:14:31 -0800128};
129/* Macro for accessing counter */
130#define MEM_CGROUP_ZSTAT(mz, idx) ((mz)->count[(idx)])
131
132struct mem_cgroup_per_node {
133 struct mem_cgroup_per_zone zoneinfo[MAX_NR_ZONES];
134};
135
136struct mem_cgroup_lru_info {
137 struct mem_cgroup_per_node *nodeinfo[MAX_NUMNODES];
138};
139
140/*
Balbir Singhf64c3f52009-09-23 15:56:37 -0700141 * Cgroups above their limits are maintained in a RB-Tree, independent of
142 * their hierarchy representation
143 */
144
145struct mem_cgroup_tree_per_zone {
146 struct rb_root rb_root;
147 spinlock_t lock;
148};
149
150struct mem_cgroup_tree_per_node {
151 struct mem_cgroup_tree_per_zone rb_tree_per_zone[MAX_NR_ZONES];
152};
153
154struct mem_cgroup_tree {
155 struct mem_cgroup_tree_per_node *rb_tree_per_node[MAX_NUMNODES];
156};
157
158static struct mem_cgroup_tree soft_limit_tree __read_mostly;
159
Kirill A. Shutemov2e72b632010-03-10 15:22:24 -0800160struct mem_cgroup_threshold {
161 struct eventfd_ctx *eventfd;
162 u64 threshold;
163};
164
KAMEZAWA Hiroyuki9490ff22010-05-26 14:42:36 -0700165/* For threshold */
Kirill A. Shutemov2e72b632010-03-10 15:22:24 -0800166struct mem_cgroup_threshold_ary {
167 /* An array index points to threshold just below usage. */
Phil Carmody5407a562010-05-26 14:42:42 -0700168 int current_threshold;
Kirill A. Shutemov2e72b632010-03-10 15:22:24 -0800169 /* Size of entries[] */
170 unsigned int size;
171 /* Array of thresholds */
172 struct mem_cgroup_threshold entries[0];
173};
Kirill A. Shutemov2c488db2010-05-26 14:42:47 -0700174
175struct mem_cgroup_thresholds {
176 /* Primary thresholds array */
177 struct mem_cgroup_threshold_ary *primary;
178 /*
179 * Spare threshold array.
180 * This is needed to make mem_cgroup_unregister_event() "never fail".
181 * It must be able to store at least primary->size - 1 entries.
182 */
183 struct mem_cgroup_threshold_ary *spare;
184};
185
KAMEZAWA Hiroyuki9490ff22010-05-26 14:42:36 -0700186/* for OOM */
187struct mem_cgroup_eventfd_list {
188 struct list_head list;
189 struct eventfd_ctx *eventfd;
190};
Kirill A. Shutemov2e72b632010-03-10 15:22:24 -0800191
Kirill A. Shutemov2e72b632010-03-10 15:22:24 -0800192static void mem_cgroup_threshold(struct mem_cgroup *mem);
KAMEZAWA Hiroyuki9490ff22010-05-26 14:42:36 -0700193static void mem_cgroup_oom_notify(struct mem_cgroup *mem);
Kirill A. Shutemov2e72b632010-03-10 15:22:24 -0800194
Balbir Singhf64c3f52009-09-23 15:56:37 -0700195/*
Balbir Singh8cdea7c2008-02-07 00:13:50 -0800196 * The memory controller data structure. The memory controller controls both
197 * page cache and RSS per cgroup. We would eventually like to provide
198 * statistics based on the statistics developed by Rik Van Riel for clock-pro,
199 * to help the administrator determine what knobs to tune.
200 *
201 * TODO: Add a water mark for the memory controller. Reclaim will begin when
Balbir Singh8a9f3cc2008-02-07 00:13:53 -0800202 * we hit the water mark. May be even add a low water mark, such that
203 * no reclaim occurs from a cgroup at it's low water mark, this is
204 * a feature that will be implemented much later in the future.
Balbir Singh8cdea7c2008-02-07 00:13:50 -0800205 */
206struct mem_cgroup {
207 struct cgroup_subsys_state css;
208 /*
209 * the counter to account for memory usage
210 */
211 struct res_counter res;
Pavel Emelianov78fb7462008-02-07 00:13:51 -0800212 /*
KAMEZAWA Hiroyuki8c7c6e32009-01-07 18:08:00 -0800213 * the counter to account for mem+swap usage.
214 */
215 struct res_counter memsw;
216 /*
Pavel Emelianov78fb7462008-02-07 00:13:51 -0800217 * Per cgroup active and inactive list, similar to the
218 * per zone LRU lists.
Pavel Emelianov78fb7462008-02-07 00:13:51 -0800219 */
KAMEZAWA Hiroyuki6d12e2d2008-02-07 00:14:31 -0800220 struct mem_cgroup_lru_info info;
KAMEZAWA Hiroyuki072c56c2008-02-07 00:14:39 -0800221
KOSAKI Motohiro2733c062009-01-07 18:08:23 -0800222 /*
223 protect against reclaim related member.
224 */
225 spinlock_t reclaim_param_lock;
226
Balbir Singh6d61ef42009-01-07 18:08:06 -0800227 /*
André Goddard Rosaaf901ca2009-11-14 13:09:05 -0200228 * While reclaiming in a hierarchy, we cache the last child we
KAMEZAWA Hiroyuki04046e12009-04-02 16:57:33 -0700229 * reclaimed from.
Balbir Singh6d61ef42009-01-07 18:08:06 -0800230 */
KAMEZAWA Hiroyuki04046e12009-04-02 16:57:33 -0700231 int last_scanned_child;
Balbir Singh18f59ea2009-01-07 18:08:07 -0800232 /*
233 * Should the accounting and control be hierarchical, per subtree?
234 */
235 bool use_hierarchy;
KAMEZAWA Hiroyuki867578c2010-03-10 15:22:39 -0800236 atomic_t oom_lock;
KAMEZAWA Hiroyuki8c7c6e32009-01-07 18:08:00 -0800237 atomic_t refcnt;
KOSAKI Motohiro14797e22009-01-07 18:08:18 -0800238
KOSAKI Motohiroa7885eb2009-01-07 18:08:24 -0800239 unsigned int swappiness;
KAMEZAWA Hiroyuki3c11ecf2010-05-26 14:42:37 -0700240 /* OOM-Killer disable */
241 int oom_kill_disable;
KOSAKI Motohiroa7885eb2009-01-07 18:08:24 -0800242
KAMEZAWA Hiroyuki22a668d2009-06-17 16:27:19 -0700243 /* set when res.limit == memsw.limit */
244 bool memsw_is_minimum;
245
Kirill A. Shutemov2e72b632010-03-10 15:22:24 -0800246 /* protect arrays of thresholds */
247 struct mutex thresholds_lock;
248
249 /* thresholds for memory usage. RCU-protected */
Kirill A. Shutemov2c488db2010-05-26 14:42:47 -0700250 struct mem_cgroup_thresholds thresholds;
Kirill A. Shutemov907860e2010-05-26 14:42:46 -0700251
Kirill A. Shutemov2e72b632010-03-10 15:22:24 -0800252 /* thresholds for mem+swap usage. RCU-protected */
Kirill A. Shutemov2c488db2010-05-26 14:42:47 -0700253 struct mem_cgroup_thresholds memsw_thresholds;
Kirill A. Shutemov907860e2010-05-26 14:42:46 -0700254
KAMEZAWA Hiroyuki9490ff22010-05-26 14:42:36 -0700255 /* For oom notifier event fd */
256 struct list_head oom_notify;
257
KAMEZAWA Hiroyukid52aa412008-02-07 00:14:24 -0800258 /*
Daisuke Nishimura7dc74be2010-03-10 15:22:13 -0800259 * Should we move charges of a task when a task is moved into this
260 * mem_cgroup ? And what type of charges should we move ?
261 */
262 unsigned long move_charge_at_immigrate;
Daisuke Nishimura7dc74be2010-03-10 15:22:13 -0800263 /*
KAMEZAWA Hiroyukic62b1a32010-03-10 15:22:29 -0800264 * percpu counter.
KAMEZAWA Hiroyukid52aa412008-02-07 00:14:24 -0800265 */
KAMEZAWA Hiroyukic62b1a32010-03-10 15:22:29 -0800266 struct mem_cgroup_stat_cpu *stat;
KAMEZAWA Hiroyuki711d3d22010-10-27 15:33:42 -0700267 /*
268 * used when a cpu is offlined or other synchronizations
269 * See mem_cgroup_read_stat().
270 */
271 struct mem_cgroup_stat_cpu nocpu_base;
272 spinlock_t pcp_counter_lock;
Balbir Singh8cdea7c2008-02-07 00:13:50 -0800273};
274
Daisuke Nishimura7dc74be2010-03-10 15:22:13 -0800275/* Stuffs for move charges at task migration. */
276/*
277 * Types of charges to be moved. "move_charge_at_immitgrate" is treated as a
278 * left-shifted bitmap of these types.
279 */
280enum move_type {
Daisuke Nishimura4ffef5f2010-03-10 15:22:14 -0800281 MOVE_CHARGE_TYPE_ANON, /* private anonymous page and swap of it */
Daisuke Nishimura87946a72010-05-26 14:42:39 -0700282 MOVE_CHARGE_TYPE_FILE, /* file page(including tmpfs) and swap of it */
Daisuke Nishimura7dc74be2010-03-10 15:22:13 -0800283 NR_MOVE_TYPE,
284};
285
Daisuke Nishimura4ffef5f2010-03-10 15:22:14 -0800286/* "mc" and its members are protected by cgroup_mutex */
287static struct move_charge_struct {
Daisuke Nishimurab1dd6932010-11-24 12:57:06 -0800288 spinlock_t lock; /* for from, to */
Daisuke Nishimura4ffef5f2010-03-10 15:22:14 -0800289 struct mem_cgroup *from;
290 struct mem_cgroup *to;
291 unsigned long precharge;
Daisuke Nishimura854ffa82010-03-10 15:22:15 -0800292 unsigned long moved_charge;
Daisuke Nishimura483c30b2010-03-10 15:22:18 -0800293 unsigned long moved_swap;
Daisuke Nishimura8033b972010-03-10 15:22:16 -0800294 struct task_struct *moving_task; /* a task moving charges */
295 wait_queue_head_t waitq; /* a waitq for other context */
296} mc = {
KAMEZAWA Hiroyuki2bd9bb22010-08-10 18:02:58 -0700297 .lock = __SPIN_LOCK_UNLOCKED(mc.lock),
Daisuke Nishimura8033b972010-03-10 15:22:16 -0800298 .waitq = __WAIT_QUEUE_HEAD_INITIALIZER(mc.waitq),
299};
Daisuke Nishimura4ffef5f2010-03-10 15:22:14 -0800300
Daisuke Nishimura90254a62010-05-26 14:42:38 -0700301static bool move_anon(void)
302{
303 return test_bit(MOVE_CHARGE_TYPE_ANON,
304 &mc.to->move_charge_at_immigrate);
305}
306
Daisuke Nishimura87946a72010-05-26 14:42:39 -0700307static bool move_file(void)
308{
309 return test_bit(MOVE_CHARGE_TYPE_FILE,
310 &mc.to->move_charge_at_immigrate);
311}
312
Balbir Singh4e416952009-09-23 15:56:39 -0700313/*
314 * Maximum loops in mem_cgroup_hierarchical_reclaim(), used for soft
315 * limit reclaim to prevent infinite loops, if they ever occur.
316 */
317#define MEM_CGROUP_MAX_RECLAIM_LOOPS (100)
318#define MEM_CGROUP_MAX_SOFT_LIMIT_RECLAIM_LOOPS (2)
319
KAMEZAWA Hiroyuki217bc312008-02-07 00:14:17 -0800320enum charge_type {
321 MEM_CGROUP_CHARGE_TYPE_CACHE = 0,
322 MEM_CGROUP_CHARGE_TYPE_MAPPED,
Rik van Riel4f98a2f2008-10-18 20:26:32 -0700323 MEM_CGROUP_CHARGE_TYPE_SHMEM, /* used by page migration of shmem */
KAMEZAWA Hiroyukic05555b2008-10-18 20:28:11 -0700324 MEM_CGROUP_CHARGE_TYPE_FORCE, /* used by force_empty */
KAMEZAWA Hiroyukid13d1442009-01-07 18:07:56 -0800325 MEM_CGROUP_CHARGE_TYPE_SWAPOUT, /* for accounting swapcache */
KAMEZAWA Hiroyuki8a9478c2009-06-17 16:27:17 -0700326 MEM_CGROUP_CHARGE_TYPE_DROP, /* a page was unused swap cache */
KAMEZAWA Hiroyukic05555b2008-10-18 20:28:11 -0700327 NR_CHARGE_TYPE,
328};
329
KAMEZAWA Hiroyuki52d4b9a2008-10-18 20:28:16 -0700330/* only for here (for easy reading.) */
331#define PCGF_CACHE (1UL << PCG_CACHE)
332#define PCGF_USED (1UL << PCG_USED)
KAMEZAWA Hiroyuki52d4b9a2008-10-18 20:28:16 -0700333#define PCGF_LOCK (1UL << PCG_LOCK)
Balbir Singh4b3bde42009-09-23 15:56:32 -0700334/* Not used, but added here for completeness */
335#define PCGF_ACCT (1UL << PCG_ACCT)
KAMEZAWA Hiroyuki217bc312008-02-07 00:14:17 -0800336
KAMEZAWA Hiroyuki8c7c6e32009-01-07 18:08:00 -0800337/* for encoding cft->private value on file */
338#define _MEM (0)
339#define _MEMSWAP (1)
KAMEZAWA Hiroyuki9490ff22010-05-26 14:42:36 -0700340#define _OOM_TYPE (2)
KAMEZAWA Hiroyuki8c7c6e32009-01-07 18:08:00 -0800341#define MEMFILE_PRIVATE(x, val) (((x) << 16) | (val))
342#define MEMFILE_TYPE(val) (((val) >> 16) & 0xffff)
343#define MEMFILE_ATTR(val) ((val) & 0xffff)
KAMEZAWA Hiroyuki9490ff22010-05-26 14:42:36 -0700344/* Used for OOM nofiier */
345#define OOM_CONTROL (0)
KAMEZAWA Hiroyuki8c7c6e32009-01-07 18:08:00 -0800346
Balbir Singh75822b42009-09-23 15:56:38 -0700347/*
348 * Reclaim flags for mem_cgroup_hierarchical_reclaim
349 */
350#define MEM_CGROUP_RECLAIM_NOSWAP_BIT 0x0
351#define MEM_CGROUP_RECLAIM_NOSWAP (1 << MEM_CGROUP_RECLAIM_NOSWAP_BIT)
352#define MEM_CGROUP_RECLAIM_SHRINK_BIT 0x1
353#define MEM_CGROUP_RECLAIM_SHRINK (1 << MEM_CGROUP_RECLAIM_SHRINK_BIT)
Balbir Singh4e416952009-09-23 15:56:39 -0700354#define MEM_CGROUP_RECLAIM_SOFT_BIT 0x2
355#define MEM_CGROUP_RECLAIM_SOFT (1 << MEM_CGROUP_RECLAIM_SOFT_BIT)
Balbir Singh75822b42009-09-23 15:56:38 -0700356
KAMEZAWA Hiroyuki8c7c6e32009-01-07 18:08:00 -0800357static void mem_cgroup_get(struct mem_cgroup *mem);
358static void mem_cgroup_put(struct mem_cgroup *mem);
Daisuke Nishimura7bcc1bb2009-01-29 14:25:11 -0800359static struct mem_cgroup *parent_mem_cgroup(struct mem_cgroup *mem);
KAMEZAWA Hiroyukicdec2e42009-12-15 16:47:08 -0800360static void drain_all_stock_async(void);
KAMEZAWA Hiroyuki8c7c6e32009-01-07 18:08:00 -0800361
Balbir Singhf64c3f52009-09-23 15:56:37 -0700362static struct mem_cgroup_per_zone *
363mem_cgroup_zoneinfo(struct mem_cgroup *mem, int nid, int zid)
364{
365 return &mem->info.nodeinfo[nid]->zoneinfo[zid];
366}
367
Wu Fengguangd3242362009-12-16 12:19:59 +0100368struct cgroup_subsys_state *mem_cgroup_css(struct mem_cgroup *mem)
369{
370 return &mem->css;
371}
372
Balbir Singhf64c3f52009-09-23 15:56:37 -0700373static struct mem_cgroup_per_zone *
374page_cgroup_zoneinfo(struct page_cgroup *pc)
375{
376 struct mem_cgroup *mem = pc->mem_cgroup;
377 int nid = page_cgroup_nid(pc);
378 int zid = page_cgroup_zid(pc);
379
380 if (!mem)
381 return NULL;
382
383 return mem_cgroup_zoneinfo(mem, nid, zid);
384}
385
386static struct mem_cgroup_tree_per_zone *
387soft_limit_tree_node_zone(int nid, int zid)
388{
389 return &soft_limit_tree.rb_tree_per_node[nid]->rb_tree_per_zone[zid];
390}
391
392static struct mem_cgroup_tree_per_zone *
393soft_limit_tree_from_page(struct page *page)
394{
395 int nid = page_to_nid(page);
396 int zid = page_zonenum(page);
397
398 return &soft_limit_tree.rb_tree_per_node[nid]->rb_tree_per_zone[zid];
399}
400
401static void
Balbir Singh4e416952009-09-23 15:56:39 -0700402__mem_cgroup_insert_exceeded(struct mem_cgroup *mem,
Balbir Singhf64c3f52009-09-23 15:56:37 -0700403 struct mem_cgroup_per_zone *mz,
KAMEZAWA Hiroyukief8745c2009-10-01 15:44:12 -0700404 struct mem_cgroup_tree_per_zone *mctz,
405 unsigned long long new_usage_in_excess)
Balbir Singhf64c3f52009-09-23 15:56:37 -0700406{
407 struct rb_node **p = &mctz->rb_root.rb_node;
408 struct rb_node *parent = NULL;
409 struct mem_cgroup_per_zone *mz_node;
410
411 if (mz->on_tree)
412 return;
413
KAMEZAWA Hiroyukief8745c2009-10-01 15:44:12 -0700414 mz->usage_in_excess = new_usage_in_excess;
415 if (!mz->usage_in_excess)
416 return;
Balbir Singhf64c3f52009-09-23 15:56:37 -0700417 while (*p) {
418 parent = *p;
419 mz_node = rb_entry(parent, struct mem_cgroup_per_zone,
420 tree_node);
421 if (mz->usage_in_excess < mz_node->usage_in_excess)
422 p = &(*p)->rb_left;
423 /*
424 * We can't avoid mem cgroups that are over their soft
425 * limit by the same amount
426 */
427 else if (mz->usage_in_excess >= mz_node->usage_in_excess)
428 p = &(*p)->rb_right;
429 }
430 rb_link_node(&mz->tree_node, parent, p);
431 rb_insert_color(&mz->tree_node, &mctz->rb_root);
432 mz->on_tree = true;
Balbir Singh4e416952009-09-23 15:56:39 -0700433}
434
435static void
436__mem_cgroup_remove_exceeded(struct mem_cgroup *mem,
437 struct mem_cgroup_per_zone *mz,
438 struct mem_cgroup_tree_per_zone *mctz)
439{
440 if (!mz->on_tree)
441 return;
442 rb_erase(&mz->tree_node, &mctz->rb_root);
443 mz->on_tree = false;
444}
445
446static void
Balbir Singhf64c3f52009-09-23 15:56:37 -0700447mem_cgroup_remove_exceeded(struct mem_cgroup *mem,
448 struct mem_cgroup_per_zone *mz,
449 struct mem_cgroup_tree_per_zone *mctz)
450{
451 spin_lock(&mctz->lock);
Balbir Singh4e416952009-09-23 15:56:39 -0700452 __mem_cgroup_remove_exceeded(mem, mz, mctz);
Balbir Singhf64c3f52009-09-23 15:56:37 -0700453 spin_unlock(&mctz->lock);
454}
455
Balbir Singhf64c3f52009-09-23 15:56:37 -0700456
457static void mem_cgroup_update_tree(struct mem_cgroup *mem, struct page *page)
458{
KAMEZAWA Hiroyukief8745c2009-10-01 15:44:12 -0700459 unsigned long long excess;
Balbir Singhf64c3f52009-09-23 15:56:37 -0700460 struct mem_cgroup_per_zone *mz;
461 struct mem_cgroup_tree_per_zone *mctz;
KAMEZAWA Hiroyuki4e649152009-10-01 15:44:11 -0700462 int nid = page_to_nid(page);
463 int zid = page_zonenum(page);
Balbir Singhf64c3f52009-09-23 15:56:37 -0700464 mctz = soft_limit_tree_from_page(page);
465
466 /*
KAMEZAWA Hiroyuki4e649152009-10-01 15:44:11 -0700467 * Necessary to update all ancestors when hierarchy is used.
468 * because their event counter is not touched.
Balbir Singhf64c3f52009-09-23 15:56:37 -0700469 */
KAMEZAWA Hiroyuki4e649152009-10-01 15:44:11 -0700470 for (; mem; mem = parent_mem_cgroup(mem)) {
471 mz = mem_cgroup_zoneinfo(mem, nid, zid);
KAMEZAWA Hiroyukief8745c2009-10-01 15:44:12 -0700472 excess = res_counter_soft_limit_excess(&mem->res);
KAMEZAWA Hiroyuki4e649152009-10-01 15:44:11 -0700473 /*
474 * We have to update the tree if mz is on RB-tree or
475 * mem is over its softlimit.
476 */
KAMEZAWA Hiroyukief8745c2009-10-01 15:44:12 -0700477 if (excess || mz->on_tree) {
KAMEZAWA Hiroyuki4e649152009-10-01 15:44:11 -0700478 spin_lock(&mctz->lock);
479 /* if on-tree, remove it */
480 if (mz->on_tree)
481 __mem_cgroup_remove_exceeded(mem, mz, mctz);
482 /*
KAMEZAWA Hiroyukief8745c2009-10-01 15:44:12 -0700483 * Insert again. mz->usage_in_excess will be updated.
484 * If excess is 0, no tree ops.
KAMEZAWA Hiroyuki4e649152009-10-01 15:44:11 -0700485 */
KAMEZAWA Hiroyukief8745c2009-10-01 15:44:12 -0700486 __mem_cgroup_insert_exceeded(mem, mz, mctz, excess);
KAMEZAWA Hiroyuki4e649152009-10-01 15:44:11 -0700487 spin_unlock(&mctz->lock);
488 }
Balbir Singhf64c3f52009-09-23 15:56:37 -0700489 }
490}
491
492static void mem_cgroup_remove_from_trees(struct mem_cgroup *mem)
493{
494 int node, zone;
495 struct mem_cgroup_per_zone *mz;
496 struct mem_cgroup_tree_per_zone *mctz;
497
498 for_each_node_state(node, N_POSSIBLE) {
499 for (zone = 0; zone < MAX_NR_ZONES; zone++) {
500 mz = mem_cgroup_zoneinfo(mem, node, zone);
501 mctz = soft_limit_tree_node_zone(node, zone);
502 mem_cgroup_remove_exceeded(mem, mz, mctz);
503 }
504 }
505}
506
Balbir Singh4e416952009-09-23 15:56:39 -0700507static inline unsigned long mem_cgroup_get_excess(struct mem_cgroup *mem)
508{
509 return res_counter_soft_limit_excess(&mem->res) >> PAGE_SHIFT;
510}
511
512static struct mem_cgroup_per_zone *
513__mem_cgroup_largest_soft_limit_node(struct mem_cgroup_tree_per_zone *mctz)
514{
515 struct rb_node *rightmost = NULL;
KAMEZAWA Hiroyuki26251ea2009-10-01 15:44:08 -0700516 struct mem_cgroup_per_zone *mz;
Balbir Singh4e416952009-09-23 15:56:39 -0700517
518retry:
KAMEZAWA Hiroyuki26251ea2009-10-01 15:44:08 -0700519 mz = NULL;
Balbir Singh4e416952009-09-23 15:56:39 -0700520 rightmost = rb_last(&mctz->rb_root);
521 if (!rightmost)
522 goto done; /* Nothing to reclaim from */
523
524 mz = rb_entry(rightmost, struct mem_cgroup_per_zone, tree_node);
525 /*
526 * Remove the node now but someone else can add it back,
527 * we will to add it back at the end of reclaim to its correct
528 * position in the tree.
529 */
530 __mem_cgroup_remove_exceeded(mz->mem, mz, mctz);
531 if (!res_counter_soft_limit_excess(&mz->mem->res) ||
532 !css_tryget(&mz->mem->css))
533 goto retry;
534done:
535 return mz;
536}
537
538static struct mem_cgroup_per_zone *
539mem_cgroup_largest_soft_limit_node(struct mem_cgroup_tree_per_zone *mctz)
540{
541 struct mem_cgroup_per_zone *mz;
542
543 spin_lock(&mctz->lock);
544 mz = __mem_cgroup_largest_soft_limit_node(mctz);
545 spin_unlock(&mctz->lock);
546 return mz;
547}
548
KAMEZAWA Hiroyuki711d3d22010-10-27 15:33:42 -0700549/*
550 * Implementation Note: reading percpu statistics for memcg.
551 *
552 * Both of vmstat[] and percpu_counter has threshold and do periodic
553 * synchronization to implement "quick" read. There are trade-off between
554 * reading cost and precision of value. Then, we may have a chance to implement
555 * a periodic synchronizion of counter in memcg's counter.
556 *
557 * But this _read() function is used for user interface now. The user accounts
558 * memory usage by memory cgroup and he _always_ requires exact value because
559 * he accounts memory. Even if we provide quick-and-fuzzy read, we always
560 * have to visit all online cpus and make sum. So, for now, unnecessary
561 * synchronization is not implemented. (just implemented for cpu hotplug)
562 *
563 * If there are kernel internal actions which can make use of some not-exact
564 * value, and reading all cpu value can be performance bottleneck in some
565 * common workload, threashold and synchonization as vmstat[] should be
566 * implemented.
567 */
KAMEZAWA Hiroyukic62b1a32010-03-10 15:22:29 -0800568static s64 mem_cgroup_read_stat(struct mem_cgroup *mem,
569 enum mem_cgroup_stat_index idx)
570{
571 int cpu;
572 s64 val = 0;
573
KAMEZAWA Hiroyuki711d3d22010-10-27 15:33:42 -0700574 get_online_cpus();
575 for_each_online_cpu(cpu)
KAMEZAWA Hiroyukic62b1a32010-03-10 15:22:29 -0800576 val += per_cpu(mem->stat->count[idx], cpu);
KAMEZAWA Hiroyuki711d3d22010-10-27 15:33:42 -0700577#ifdef CONFIG_HOTPLUG_CPU
578 spin_lock(&mem->pcp_counter_lock);
579 val += mem->nocpu_base.count[idx];
580 spin_unlock(&mem->pcp_counter_lock);
581#endif
582 put_online_cpus();
KAMEZAWA Hiroyukic62b1a32010-03-10 15:22:29 -0800583 return val;
584}
585
586static s64 mem_cgroup_local_usage(struct mem_cgroup *mem)
587{
588 s64 ret;
589
590 ret = mem_cgroup_read_stat(mem, MEM_CGROUP_STAT_RSS);
591 ret += mem_cgroup_read_stat(mem, MEM_CGROUP_STAT_CACHE);
592 return ret;
593}
594
Balbir Singh0c3e73e2009-09-23 15:56:42 -0700595static void mem_cgroup_swap_statistics(struct mem_cgroup *mem,
596 bool charge)
597{
598 int val = (charge) ? 1 : -1;
KAMEZAWA Hiroyukic62b1a32010-03-10 15:22:29 -0800599 this_cpu_add(mem->stat->count[MEM_CGROUP_STAT_SWAPOUT], val);
Balbir Singh0c3e73e2009-09-23 15:56:42 -0700600}
601
KAMEZAWA Hiroyukic05555b2008-10-18 20:28:11 -0700602static void mem_cgroup_charge_statistics(struct mem_cgroup *mem,
KAMEZAWA Hiroyukie401f172011-01-20 14:44:23 -0800603 bool file, int nr_pages)
KAMEZAWA Hiroyukid52aa412008-02-07 00:14:24 -0800604{
KAMEZAWA Hiroyukic62b1a32010-03-10 15:22:29 -0800605 preempt_disable();
606
KAMEZAWA Hiroyukie401f172011-01-20 14:44:23 -0800607 if (file)
608 __this_cpu_add(mem->stat->count[MEM_CGROUP_STAT_CACHE], nr_pages);
KAMEZAWA Hiroyukid52aa412008-02-07 00:14:24 -0800609 else
KAMEZAWA Hiroyukie401f172011-01-20 14:44:23 -0800610 __this_cpu_add(mem->stat->count[MEM_CGROUP_STAT_RSS], nr_pages);
Balaji Rao55e462b2008-05-01 04:35:12 -0700611
KAMEZAWA Hiroyukie401f172011-01-20 14:44:23 -0800612 /* pagein of a big page is an event. So, ignore page size */
613 if (nr_pages > 0)
KAMEZAWA Hiroyukic62b1a32010-03-10 15:22:29 -0800614 __this_cpu_inc(mem->stat->count[MEM_CGROUP_STAT_PGPGIN_COUNT]);
Balaji Rao55e462b2008-05-01 04:35:12 -0700615 else
KAMEZAWA Hiroyukic62b1a32010-03-10 15:22:29 -0800616 __this_cpu_inc(mem->stat->count[MEM_CGROUP_STAT_PGPGOUT_COUNT]);
KAMEZAWA Hiroyukie401f172011-01-20 14:44:23 -0800617
618 __this_cpu_add(mem->stat->count[MEM_CGROUP_EVENTS], nr_pages);
Kirill A. Shutemov2e72b632010-03-10 15:22:24 -0800619
KAMEZAWA Hiroyukic62b1a32010-03-10 15:22:29 -0800620 preempt_enable();
KAMEZAWA Hiroyuki6d12e2d2008-02-07 00:14:31 -0800621}
KAMEZAWA Hiroyukid52aa412008-02-07 00:14:24 -0800622
KAMEZAWA Hiroyuki14067bb2009-04-02 16:57:35 -0700623static unsigned long mem_cgroup_get_local_zonestat(struct mem_cgroup *mem,
Christoph Lameterb69408e2008-10-18 20:26:14 -0700624 enum lru_list idx)
KAMEZAWA Hiroyuki6d12e2d2008-02-07 00:14:31 -0800625{
626 int nid, zid;
627 struct mem_cgroup_per_zone *mz;
628 u64 total = 0;
629
630 for_each_online_node(nid)
631 for (zid = 0; zid < MAX_NR_ZONES; zid++) {
632 mz = mem_cgroup_zoneinfo(mem, nid, zid);
633 total += MEM_CGROUP_ZSTAT(mz, idx);
634 }
635 return total;
KAMEZAWA Hiroyukid52aa412008-02-07 00:14:24 -0800636}
637
KAMEZAWA Hiroyukid2265e62010-03-10 15:22:31 -0800638static bool __memcg_event_check(struct mem_cgroup *mem, int event_mask_shift)
639{
640 s64 val;
641
642 val = this_cpu_read(mem->stat->count[MEM_CGROUP_EVENTS]);
643
644 return !(val & ((1 << event_mask_shift) - 1));
645}
646
647/*
648 * Check events in order.
649 *
650 */
651static void memcg_check_events(struct mem_cgroup *mem, struct page *page)
652{
653 /* threshold event is triggered in finer grain than soft limit */
654 if (unlikely(__memcg_event_check(mem, THRESHOLDS_EVENTS_THRESH))) {
655 mem_cgroup_threshold(mem);
656 if (unlikely(__memcg_event_check(mem, SOFTLIMIT_EVENTS_THRESH)))
657 mem_cgroup_update_tree(mem, page);
658 }
659}
660
Hugh Dickinsd5b69e32008-03-04 14:29:10 -0800661static struct mem_cgroup *mem_cgroup_from_cont(struct cgroup *cont)
Balbir Singh8cdea7c2008-02-07 00:13:50 -0800662{
663 return container_of(cgroup_subsys_state(cont,
664 mem_cgroup_subsys_id), struct mem_cgroup,
665 css);
666}
667
Balbir Singhcf475ad2008-04-29 01:00:16 -0700668struct mem_cgroup *mem_cgroup_from_task(struct task_struct *p)
Pavel Emelianov78fb7462008-02-07 00:13:51 -0800669{
Balbir Singh31a78f22008-09-28 23:09:31 +0100670 /*
671 * mm_update_next_owner() may clear mm->owner to NULL
672 * if it races with swapoff, page migration, etc.
673 * So this can be called with p == NULL.
674 */
675 if (unlikely(!p))
676 return NULL;
677
Pavel Emelianov78fb7462008-02-07 00:13:51 -0800678 return container_of(task_subsys_state(p, mem_cgroup_subsys_id),
679 struct mem_cgroup, css);
680}
681
KAMEZAWA Hiroyuki54595fe2009-01-07 18:08:33 -0800682static struct mem_cgroup *try_get_mem_cgroup_from_mm(struct mm_struct *mm)
683{
684 struct mem_cgroup *mem = NULL;
KAMEZAWA Hiroyuki0b7f5692009-04-02 16:57:38 -0700685
686 if (!mm)
687 return NULL;
KAMEZAWA Hiroyuki54595fe2009-01-07 18:08:33 -0800688 /*
689 * Because we have no locks, mm->owner's may be being moved to other
690 * cgroup. We use css_tryget() here even if this looks
691 * pessimistic (rather than adding locks here).
692 */
693 rcu_read_lock();
694 do {
695 mem = mem_cgroup_from_task(rcu_dereference(mm->owner));
696 if (unlikely(!mem))
697 break;
698 } while (!css_tryget(&mem->css));
699 rcu_read_unlock();
700 return mem;
701}
702
KAMEZAWA Hiroyuki7d74b062010-10-27 15:33:41 -0700703/* The caller has to guarantee "mem" exists before calling this */
704static struct mem_cgroup *mem_cgroup_start_loop(struct mem_cgroup *mem)
KAMEZAWA Hiroyuki14067bb2009-04-02 16:57:35 -0700705{
KAMEZAWA Hiroyuki711d3d22010-10-27 15:33:42 -0700706 struct cgroup_subsys_state *css;
707 int found;
708
709 if (!mem) /* ROOT cgroup has the smallest ID */
710 return root_mem_cgroup; /*css_put/get against root is ignored*/
711 if (!mem->use_hierarchy) {
712 if (css_tryget(&mem->css))
713 return mem;
714 return NULL;
715 }
716 rcu_read_lock();
717 /*
718 * searching a memory cgroup which has the smallest ID under given
719 * ROOT cgroup. (ID >= 1)
720 */
721 css = css_get_next(&mem_cgroup_subsys, 1, &mem->css, &found);
722 if (css && css_tryget(css))
723 mem = container_of(css, struct mem_cgroup, css);
724 else
725 mem = NULL;
726 rcu_read_unlock();
727 return mem;
KAMEZAWA Hiroyuki14067bb2009-04-02 16:57:35 -0700728}
729
KAMEZAWA Hiroyuki7d74b062010-10-27 15:33:41 -0700730static struct mem_cgroup *mem_cgroup_get_next(struct mem_cgroup *iter,
731 struct mem_cgroup *root,
732 bool cond)
733{
734 int nextid = css_id(&iter->css) + 1;
735 int found;
736 int hierarchy_used;
737 struct cgroup_subsys_state *css;
738
739 hierarchy_used = iter->use_hierarchy;
740
741 css_put(&iter->css);
KAMEZAWA Hiroyuki711d3d22010-10-27 15:33:42 -0700742 /* If no ROOT, walk all, ignore hierarchy */
743 if (!cond || (root && !hierarchy_used))
KAMEZAWA Hiroyuki7d74b062010-10-27 15:33:41 -0700744 return NULL;
745
KAMEZAWA Hiroyuki711d3d22010-10-27 15:33:42 -0700746 if (!root)
747 root = root_mem_cgroup;
748
KAMEZAWA Hiroyuki7d74b062010-10-27 15:33:41 -0700749 do {
750 iter = NULL;
751 rcu_read_lock();
752
753 css = css_get_next(&mem_cgroup_subsys, nextid,
754 &root->css, &found);
755 if (css && css_tryget(css))
756 iter = container_of(css, struct mem_cgroup, css);
757 rcu_read_unlock();
758 /* If css is NULL, no more cgroups will be found */
759 nextid = found + 1;
760 } while (css && !iter);
761
762 return iter;
763}
764/*
765 * for_eacn_mem_cgroup_tree() for visiting all cgroup under tree. Please
766 * be careful that "break" loop is not allowed. We have reference count.
767 * Instead of that modify "cond" to be false and "continue" to exit the loop.
768 */
769#define for_each_mem_cgroup_tree_cond(iter, root, cond) \
770 for (iter = mem_cgroup_start_loop(root);\
771 iter != NULL;\
772 iter = mem_cgroup_get_next(iter, root, cond))
773
774#define for_each_mem_cgroup_tree(iter, root) \
775 for_each_mem_cgroup_tree_cond(iter, root, true)
776
KAMEZAWA Hiroyuki711d3d22010-10-27 15:33:42 -0700777#define for_each_mem_cgroup_all(iter) \
778 for_each_mem_cgroup_tree_cond(iter, NULL, true)
779
KAMEZAWA Hiroyuki7d74b062010-10-27 15:33:41 -0700780
Balbir Singh4b3bde42009-09-23 15:56:32 -0700781static inline bool mem_cgroup_is_root(struct mem_cgroup *mem)
782{
783 return (mem == root_mem_cgroup);
784}
785
KAMEZAWA Hiroyuki08e552c2009-01-07 18:08:01 -0800786/*
787 * Following LRU functions are allowed to be used without PCG_LOCK.
788 * Operations are called by routine of global LRU independently from memcg.
789 * What we have to take care of here is validness of pc->mem_cgroup.
790 *
791 * Changes to pc->mem_cgroup happens when
792 * 1. charge
793 * 2. moving account
794 * In typical case, "charge" is done before add-to-lru. Exception is SwapCache.
795 * It is added to LRU before charge.
796 * If PCG_USED bit is not set, page_cgroup is not added to this private LRU.
797 * When moving account, the page is not on LRU. It's isolated.
798 */
799
800void mem_cgroup_del_lru_list(struct page *page, enum lru_list lru)
KAMEZAWA Hiroyuki6d12e2d2008-02-07 00:14:31 -0800801{
KAMEZAWA Hiroyuki08e552c2009-01-07 18:08:01 -0800802 struct page_cgroup *pc;
KAMEZAWA Hiroyuki08e552c2009-01-07 18:08:01 -0800803 struct mem_cgroup_per_zone *mz;
Rik van Riel4f98a2f2008-10-18 20:26:32 -0700804
Hirokazu Takahashif8d66542009-01-07 18:08:02 -0800805 if (mem_cgroup_disabled())
KAMEZAWA Hiroyuki08e552c2009-01-07 18:08:01 -0800806 return;
807 pc = lookup_page_cgroup(page);
808 /* can happen while we handle swapcache. */
Balbir Singh4b3bde42009-09-23 15:56:32 -0700809 if (!TestClearPageCgroupAcctLRU(pc))
KAMEZAWA Hiroyuki08e552c2009-01-07 18:08:01 -0800810 return;
Balbir Singh4b3bde42009-09-23 15:56:32 -0700811 VM_BUG_ON(!pc->mem_cgroup);
KAMEZAWA Hiroyuki544122e2009-01-07 18:08:34 -0800812 /*
813 * We don't check PCG_USED bit. It's cleared when the "page" is finally
814 * removed from global LRU.
815 */
KAMEZAWA Hiroyuki08e552c2009-01-07 18:08:01 -0800816 mz = page_cgroup_zoneinfo(pc);
KAMEZAWA Hiroyukiece35ca2011-01-20 14:44:24 -0800817 /* huge page split is done under lru_lock. so, we have no races. */
818 MEM_CGROUP_ZSTAT(mz, lru) -= 1 << compound_order(page);
Balbir Singh4b3bde42009-09-23 15:56:32 -0700819 if (mem_cgroup_is_root(pc->mem_cgroup))
820 return;
821 VM_BUG_ON(list_empty(&pc->lru));
KAMEZAWA Hiroyuki08e552c2009-01-07 18:08:01 -0800822 list_del_init(&pc->lru);
KAMEZAWA Hiroyuki6d12e2d2008-02-07 00:14:31 -0800823}
824
KAMEZAWA Hiroyuki08e552c2009-01-07 18:08:01 -0800825void mem_cgroup_del_lru(struct page *page)
KAMEZAWA Hiroyuki6d12e2d2008-02-07 00:14:31 -0800826{
KAMEZAWA Hiroyuki08e552c2009-01-07 18:08:01 -0800827 mem_cgroup_del_lru_list(page, page_lru(page));
KAMEZAWA Hiroyuki6d12e2d2008-02-07 00:14:31 -0800828}
829
KAMEZAWA Hiroyuki08e552c2009-01-07 18:08:01 -0800830void mem_cgroup_rotate_lru_list(struct page *page, enum lru_list lru)
Balbir Singh66e17072008-02-07 00:13:56 -0800831{
KAMEZAWA Hiroyuki08e552c2009-01-07 18:08:01 -0800832 struct mem_cgroup_per_zone *mz;
833 struct page_cgroup *pc;
KAMEZAWA Hiroyuki6d12e2d2008-02-07 00:14:31 -0800834
Hirokazu Takahashif8d66542009-01-07 18:08:02 -0800835 if (mem_cgroup_disabled())
Lee Schermerhorn894bc312008-10-18 20:26:39 -0700836 return;
Christoph Lameterb69408e2008-10-18 20:26:14 -0700837
KAMEZAWA Hiroyuki08e552c2009-01-07 18:08:01 -0800838 pc = lookup_page_cgroup(page);
Balbir Singh4b3bde42009-09-23 15:56:32 -0700839 /* unused or root page is not rotated. */
Johannes Weiner713735b2011-01-20 14:44:31 -0800840 if (!PageCgroupUsed(pc))
841 return;
842 /* Ensure pc->mem_cgroup is visible after reading PCG_USED. */
843 smp_rmb();
844 if (mem_cgroup_is_root(pc->mem_cgroup))
KAMEZAWA Hiroyuki08e552c2009-01-07 18:08:01 -0800845 return;
846 mz = page_cgroup_zoneinfo(pc);
Christoph Lameterb69408e2008-10-18 20:26:14 -0700847 list_move(&pc->lru, &mz->lists[lru]);
Balbir Singh66e17072008-02-07 00:13:56 -0800848}
849
KAMEZAWA Hiroyuki08e552c2009-01-07 18:08:01 -0800850void mem_cgroup_add_lru_list(struct page *page, enum lru_list lru)
851{
852 struct page_cgroup *pc;
853 struct mem_cgroup_per_zone *mz;
854
Hirokazu Takahashif8d66542009-01-07 18:08:02 -0800855 if (mem_cgroup_disabled())
KAMEZAWA Hiroyuki08e552c2009-01-07 18:08:01 -0800856 return;
857 pc = lookup_page_cgroup(page);
Balbir Singh4b3bde42009-09-23 15:56:32 -0700858 VM_BUG_ON(PageCgroupAcctLRU(pc));
KAMEZAWA Hiroyuki08e552c2009-01-07 18:08:01 -0800859 if (!PageCgroupUsed(pc))
860 return;
Johannes Weiner713735b2011-01-20 14:44:31 -0800861 /* Ensure pc->mem_cgroup is visible after reading PCG_USED. */
862 smp_rmb();
KAMEZAWA Hiroyuki08e552c2009-01-07 18:08:01 -0800863 mz = page_cgroup_zoneinfo(pc);
KAMEZAWA Hiroyukiece35ca2011-01-20 14:44:24 -0800864 /* huge page split is done under lru_lock. so, we have no races. */
865 MEM_CGROUP_ZSTAT(mz, lru) += 1 << compound_order(page);
Balbir Singh4b3bde42009-09-23 15:56:32 -0700866 SetPageCgroupAcctLRU(pc);
867 if (mem_cgroup_is_root(pc->mem_cgroup))
868 return;
KAMEZAWA Hiroyuki08e552c2009-01-07 18:08:01 -0800869 list_add(&pc->lru, &mz->lists[lru]);
870}
KAMEZAWA Hiroyuki544122e2009-01-07 18:08:34 -0800871
KAMEZAWA Hiroyuki08e552c2009-01-07 18:08:01 -0800872/*
KAMEZAWA Hiroyuki544122e2009-01-07 18:08:34 -0800873 * At handling SwapCache, pc->mem_cgroup may be changed while it's linked to
874 * lru because the page may.be reused after it's fully uncharged (because of
875 * SwapCache behavior).To handle that, unlink page_cgroup from LRU when charge
876 * it again. This function is only used to charge SwapCache. It's done under
877 * lock_page and expected that zone->lru_lock is never held.
KAMEZAWA Hiroyuki08e552c2009-01-07 18:08:01 -0800878 */
KAMEZAWA Hiroyuki544122e2009-01-07 18:08:34 -0800879static void mem_cgroup_lru_del_before_commit_swapcache(struct page *page)
KAMEZAWA Hiroyuki08e552c2009-01-07 18:08:01 -0800880{
KAMEZAWA Hiroyuki544122e2009-01-07 18:08:34 -0800881 unsigned long flags;
882 struct zone *zone = page_zone(page);
883 struct page_cgroup *pc = lookup_page_cgroup(page);
884
885 spin_lock_irqsave(&zone->lru_lock, flags);
886 /*
887 * Forget old LRU when this page_cgroup is *not* used. This Used bit
888 * is guarded by lock_page() because the page is SwapCache.
889 */
890 if (!PageCgroupUsed(pc))
891 mem_cgroup_del_lru_list(page, page_lru(page));
892 spin_unlock_irqrestore(&zone->lru_lock, flags);
KAMEZAWA Hiroyuki08e552c2009-01-07 18:08:01 -0800893}
894
KAMEZAWA Hiroyuki544122e2009-01-07 18:08:34 -0800895static void mem_cgroup_lru_add_after_commit_swapcache(struct page *page)
896{
897 unsigned long flags;
898 struct zone *zone = page_zone(page);
899 struct page_cgroup *pc = lookup_page_cgroup(page);
900
901 spin_lock_irqsave(&zone->lru_lock, flags);
902 /* link when the page is linked to LRU but page_cgroup isn't */
Balbir Singh4b3bde42009-09-23 15:56:32 -0700903 if (PageLRU(page) && !PageCgroupAcctLRU(pc))
KAMEZAWA Hiroyuki544122e2009-01-07 18:08:34 -0800904 mem_cgroup_add_lru_list(page, page_lru(page));
905 spin_unlock_irqrestore(&zone->lru_lock, flags);
906}
907
908
KAMEZAWA Hiroyuki08e552c2009-01-07 18:08:01 -0800909void mem_cgroup_move_lists(struct page *page,
910 enum lru_list from, enum lru_list to)
911{
Hirokazu Takahashif8d66542009-01-07 18:08:02 -0800912 if (mem_cgroup_disabled())
KAMEZAWA Hiroyuki08e552c2009-01-07 18:08:01 -0800913 return;
914 mem_cgroup_del_lru_list(page, from);
915 mem_cgroup_add_lru_list(page, to);
916}
917
David Rientjes4c4a2212008-02-07 00:14:06 -0800918int task_in_mem_cgroup(struct task_struct *task, const struct mem_cgroup *mem)
919{
920 int ret;
KAMEZAWA Hiroyuki0b7f5692009-04-02 16:57:38 -0700921 struct mem_cgroup *curr = NULL;
KAMEZAWA Hiroyuki158e0a22010-08-10 18:03:00 -0700922 struct task_struct *p;
David Rientjes4c4a2212008-02-07 00:14:06 -0800923
KAMEZAWA Hiroyuki158e0a22010-08-10 18:03:00 -0700924 p = find_lock_task_mm(task);
925 if (!p)
926 return 0;
927 curr = try_get_mem_cgroup_from_mm(p->mm);
928 task_unlock(p);
KAMEZAWA Hiroyuki0b7f5692009-04-02 16:57:38 -0700929 if (!curr)
930 return 0;
Daisuke Nishimurad31f56d2009-12-15 16:47:12 -0800931 /*
932 * We should check use_hierarchy of "mem" not "curr". Because checking
933 * use_hierarchy of "curr" here make this function true if hierarchy is
934 * enabled in "curr" and "curr" is a child of "mem" in *cgroup*
935 * hierarchy(even if use_hierarchy is disabled in "mem").
936 */
937 if (mem->use_hierarchy)
KAMEZAWA Hiroyuki0b7f5692009-04-02 16:57:38 -0700938 ret = css_is_ancestor(&curr->css, &mem->css);
939 else
940 ret = (curr == mem);
941 css_put(&curr->css);
David Rientjes4c4a2212008-02-07 00:14:06 -0800942 return ret;
943}
944
KOSAKI Motohiroc772be92009-01-07 18:08:25 -0800945static int calc_inactive_ratio(struct mem_cgroup *memcg, unsigned long *present_pages)
KOSAKI Motohiro14797e22009-01-07 18:08:18 -0800946{
947 unsigned long active;
948 unsigned long inactive;
KOSAKI Motohiroc772be92009-01-07 18:08:25 -0800949 unsigned long gb;
950 unsigned long inactive_ratio;
KOSAKI Motohiro14797e22009-01-07 18:08:18 -0800951
KAMEZAWA Hiroyuki14067bb2009-04-02 16:57:35 -0700952 inactive = mem_cgroup_get_local_zonestat(memcg, LRU_INACTIVE_ANON);
953 active = mem_cgroup_get_local_zonestat(memcg, LRU_ACTIVE_ANON);
KOSAKI Motohiro14797e22009-01-07 18:08:18 -0800954
KOSAKI Motohiroc772be92009-01-07 18:08:25 -0800955 gb = (inactive + active) >> (30 - PAGE_SHIFT);
956 if (gb)
957 inactive_ratio = int_sqrt(10 * gb);
958 else
959 inactive_ratio = 1;
960
961 if (present_pages) {
962 present_pages[0] = inactive;
963 present_pages[1] = active;
964 }
965
966 return inactive_ratio;
967}
968
969int mem_cgroup_inactive_anon_is_low(struct mem_cgroup *memcg)
970{
971 unsigned long active;
972 unsigned long inactive;
973 unsigned long present_pages[2];
974 unsigned long inactive_ratio;
975
976 inactive_ratio = calc_inactive_ratio(memcg, present_pages);
977
978 inactive = present_pages[0];
979 active = present_pages[1];
980
981 if (inactive * inactive_ratio < active)
KOSAKI Motohiro14797e22009-01-07 18:08:18 -0800982 return 1;
983
984 return 0;
985}
986
Rik van Riel56e49d22009-06-16 15:32:28 -0700987int mem_cgroup_inactive_file_is_low(struct mem_cgroup *memcg)
988{
989 unsigned long active;
990 unsigned long inactive;
991
992 inactive = mem_cgroup_get_local_zonestat(memcg, LRU_INACTIVE_FILE);
993 active = mem_cgroup_get_local_zonestat(memcg, LRU_ACTIVE_FILE);
994
995 return (active > inactive);
996}
997
KOSAKI Motohiroa3d8e052009-01-07 18:08:19 -0800998unsigned long mem_cgroup_zone_nr_pages(struct mem_cgroup *memcg,
999 struct zone *zone,
1000 enum lru_list lru)
1001{
KOSAKI Motohiro13d7e3a2010-08-10 18:03:06 -07001002 int nid = zone_to_nid(zone);
KOSAKI Motohiroa3d8e052009-01-07 18:08:19 -08001003 int zid = zone_idx(zone);
1004 struct mem_cgroup_per_zone *mz = mem_cgroup_zoneinfo(memcg, nid, zid);
1005
1006 return MEM_CGROUP_ZSTAT(mz, lru);
1007}
1008
KOSAKI Motohiro3e2f41f2009-01-07 18:08:20 -08001009struct zone_reclaim_stat *mem_cgroup_get_reclaim_stat(struct mem_cgroup *memcg,
1010 struct zone *zone)
1011{
KOSAKI Motohiro13d7e3a2010-08-10 18:03:06 -07001012 int nid = zone_to_nid(zone);
KOSAKI Motohiro3e2f41f2009-01-07 18:08:20 -08001013 int zid = zone_idx(zone);
1014 struct mem_cgroup_per_zone *mz = mem_cgroup_zoneinfo(memcg, nid, zid);
1015
1016 return &mz->reclaim_stat;
1017}
1018
1019struct zone_reclaim_stat *
1020mem_cgroup_get_reclaim_stat_from_page(struct page *page)
1021{
1022 struct page_cgroup *pc;
1023 struct mem_cgroup_per_zone *mz;
1024
1025 if (mem_cgroup_disabled())
1026 return NULL;
1027
1028 pc = lookup_page_cgroup(page);
Daisuke Nishimurabd112db2009-01-15 13:51:11 -08001029 if (!PageCgroupUsed(pc))
1030 return NULL;
Johannes Weiner713735b2011-01-20 14:44:31 -08001031 /* Ensure pc->mem_cgroup is visible after reading PCG_USED. */
1032 smp_rmb();
KOSAKI Motohiro3e2f41f2009-01-07 18:08:20 -08001033 mz = page_cgroup_zoneinfo(pc);
1034 if (!mz)
1035 return NULL;
1036
1037 return &mz->reclaim_stat;
1038}
1039
Balbir Singh66e17072008-02-07 00:13:56 -08001040unsigned long mem_cgroup_isolate_pages(unsigned long nr_to_scan,
1041 struct list_head *dst,
1042 unsigned long *scanned, int order,
1043 int mode, struct zone *z,
1044 struct mem_cgroup *mem_cont,
Rik van Riel4f98a2f2008-10-18 20:26:32 -07001045 int active, int file)
Balbir Singh66e17072008-02-07 00:13:56 -08001046{
1047 unsigned long nr_taken = 0;
1048 struct page *page;
1049 unsigned long scan;
1050 LIST_HEAD(pc_list);
1051 struct list_head *src;
KAMEZAWA Hiroyukiff7283f2008-02-07 00:14:11 -08001052 struct page_cgroup *pc, *tmp;
KOSAKI Motohiro13d7e3a2010-08-10 18:03:06 -07001053 int nid = zone_to_nid(z);
KAMEZAWA Hiroyuki1ecaab22008-02-07 00:14:38 -08001054 int zid = zone_idx(z);
1055 struct mem_cgroup_per_zone *mz;
Johannes Weinerb7c46d12009-09-21 17:02:56 -07001056 int lru = LRU_FILE * file + active;
KAMEZAWA Hiroyuki2ffebca2009-06-17 16:27:21 -07001057 int ret;
Balbir Singh66e17072008-02-07 00:13:56 -08001058
Balbir Singhcf475ad2008-04-29 01:00:16 -07001059 BUG_ON(!mem_cont);
KAMEZAWA Hiroyuki1ecaab22008-02-07 00:14:38 -08001060 mz = mem_cgroup_zoneinfo(mem_cont, nid, zid);
Christoph Lameterb69408e2008-10-18 20:26:14 -07001061 src = &mz->lists[lru];
Balbir Singh66e17072008-02-07 00:13:56 -08001062
KAMEZAWA Hiroyukiff7283f2008-02-07 00:14:11 -08001063 scan = 0;
1064 list_for_each_entry_safe_reverse(pc, tmp, src, lru) {
Hugh Dickins436c65412008-02-07 00:14:12 -08001065 if (scan >= nr_to_scan)
KAMEZAWA Hiroyukiff7283f2008-02-07 00:14:11 -08001066 break;
KAMEZAWA Hiroyuki08e552c2009-01-07 18:08:01 -08001067
1068 page = pc->page;
KAMEZAWA Hiroyuki52d4b9a2008-10-18 20:28:16 -07001069 if (unlikely(!PageCgroupUsed(pc)))
1070 continue;
Hugh Dickins436c65412008-02-07 00:14:12 -08001071 if (unlikely(!PageLRU(page)))
KAMEZAWA Hiroyukiff7283f2008-02-07 00:14:11 -08001072 continue;
KAMEZAWA Hiroyukiff7283f2008-02-07 00:14:11 -08001073
Hugh Dickins436c65412008-02-07 00:14:12 -08001074 scan++;
KAMEZAWA Hiroyuki2ffebca2009-06-17 16:27:21 -07001075 ret = __isolate_lru_page(page, mode, file);
1076 switch (ret) {
1077 case 0:
Balbir Singh66e17072008-02-07 00:13:56 -08001078 list_move(&page->lru, dst);
KAMEZAWA Hiroyuki2ffebca2009-06-17 16:27:21 -07001079 mem_cgroup_del_lru(page);
Rik van Riel2c888cf2011-01-13 15:47:13 -08001080 nr_taken += hpage_nr_pages(page);
KAMEZAWA Hiroyuki2ffebca2009-06-17 16:27:21 -07001081 break;
1082 case -EBUSY:
1083 /* we don't affect global LRU but rotate in our LRU */
1084 mem_cgroup_rotate_lru_list(page, page_lru(page));
1085 break;
1086 default:
1087 break;
Balbir Singh66e17072008-02-07 00:13:56 -08001088 }
1089 }
1090
Balbir Singh66e17072008-02-07 00:13:56 -08001091 *scanned = scan;
KOSAKI Motohirocc8e9702010-08-09 17:19:57 -07001092
1093 trace_mm_vmscan_memcg_isolate(0, nr_to_scan, scan, nr_taken,
1094 0, 0, 0, mode);
1095
Balbir Singh66e17072008-02-07 00:13:56 -08001096 return nr_taken;
1097}
1098
Balbir Singh6d61ef42009-01-07 18:08:06 -08001099#define mem_cgroup_from_res_counter(counter, member) \
1100 container_of(counter, struct mem_cgroup, member)
1101
Daisuke Nishimurab85a96c2009-01-07 18:08:12 -08001102static bool mem_cgroup_check_under_limit(struct mem_cgroup *mem)
1103{
1104 if (do_swap_account) {
1105 if (res_counter_check_under_limit(&mem->res) &&
1106 res_counter_check_under_limit(&mem->memsw))
1107 return true;
1108 } else
1109 if (res_counter_check_under_limit(&mem->res))
1110 return true;
1111 return false;
1112}
1113
KOSAKI Motohiroa7885eb2009-01-07 18:08:24 -08001114static unsigned int get_swappiness(struct mem_cgroup *memcg)
1115{
1116 struct cgroup *cgrp = memcg->css.cgroup;
1117 unsigned int swappiness;
1118
1119 /* root ? */
1120 if (cgrp->parent == NULL)
1121 return vm_swappiness;
1122
1123 spin_lock(&memcg->reclaim_param_lock);
1124 swappiness = memcg->swappiness;
1125 spin_unlock(&memcg->reclaim_param_lock);
1126
1127 return swappiness;
1128}
1129
KAMEZAWA Hiroyuki32047e22010-10-27 15:33:40 -07001130static void mem_cgroup_start_move(struct mem_cgroup *mem)
1131{
1132 int cpu;
KAMEZAWA Hiroyuki1489eba2010-10-27 15:33:42 -07001133
1134 get_online_cpus();
1135 spin_lock(&mem->pcp_counter_lock);
1136 for_each_online_cpu(cpu)
KAMEZAWA Hiroyuki32047e22010-10-27 15:33:40 -07001137 per_cpu(mem->stat->count[MEM_CGROUP_ON_MOVE], cpu) += 1;
KAMEZAWA Hiroyuki1489eba2010-10-27 15:33:42 -07001138 mem->nocpu_base.count[MEM_CGROUP_ON_MOVE] += 1;
1139 spin_unlock(&mem->pcp_counter_lock);
1140 put_online_cpus();
KAMEZAWA Hiroyuki32047e22010-10-27 15:33:40 -07001141
1142 synchronize_rcu();
1143}
1144
1145static void mem_cgroup_end_move(struct mem_cgroup *mem)
1146{
1147 int cpu;
1148
1149 if (!mem)
1150 return;
KAMEZAWA Hiroyuki1489eba2010-10-27 15:33:42 -07001151 get_online_cpus();
1152 spin_lock(&mem->pcp_counter_lock);
1153 for_each_online_cpu(cpu)
KAMEZAWA Hiroyuki32047e22010-10-27 15:33:40 -07001154 per_cpu(mem->stat->count[MEM_CGROUP_ON_MOVE], cpu) -= 1;
KAMEZAWA Hiroyuki1489eba2010-10-27 15:33:42 -07001155 mem->nocpu_base.count[MEM_CGROUP_ON_MOVE] -= 1;
1156 spin_unlock(&mem->pcp_counter_lock);
1157 put_online_cpus();
KAMEZAWA Hiroyuki32047e22010-10-27 15:33:40 -07001158}
1159/*
1160 * 2 routines for checking "mem" is under move_account() or not.
1161 *
1162 * mem_cgroup_stealed() - checking a cgroup is mc.from or not. This is used
1163 * for avoiding race in accounting. If true,
1164 * pc->mem_cgroup may be overwritten.
1165 *
1166 * mem_cgroup_under_move() - checking a cgroup is mc.from or mc.to or
1167 * under hierarchy of moving cgroups. This is for
1168 * waiting at hith-memory prressure caused by "move".
1169 */
1170
1171static bool mem_cgroup_stealed(struct mem_cgroup *mem)
1172{
1173 VM_BUG_ON(!rcu_read_lock_held());
1174 return this_cpu_read(mem->stat->count[MEM_CGROUP_ON_MOVE]) > 0;
1175}
KAMEZAWA Hiroyuki4b534332010-08-10 18:02:57 -07001176
1177static bool mem_cgroup_under_move(struct mem_cgroup *mem)
1178{
KAMEZAWA Hiroyuki2bd9bb22010-08-10 18:02:58 -07001179 struct mem_cgroup *from;
1180 struct mem_cgroup *to;
KAMEZAWA Hiroyuki4b534332010-08-10 18:02:57 -07001181 bool ret = false;
KAMEZAWA Hiroyuki2bd9bb22010-08-10 18:02:58 -07001182 /*
1183 * Unlike task_move routines, we access mc.to, mc.from not under
1184 * mutual exclusion by cgroup_mutex. Here, we take spinlock instead.
1185 */
1186 spin_lock(&mc.lock);
1187 from = mc.from;
1188 to = mc.to;
1189 if (!from)
1190 goto unlock;
1191 if (from == mem || to == mem
1192 || (mem->use_hierarchy && css_is_ancestor(&from->css, &mem->css))
1193 || (mem->use_hierarchy && css_is_ancestor(&to->css, &mem->css)))
1194 ret = true;
1195unlock:
1196 spin_unlock(&mc.lock);
KAMEZAWA Hiroyuki4b534332010-08-10 18:02:57 -07001197 return ret;
1198}
1199
1200static bool mem_cgroup_wait_acct_move(struct mem_cgroup *mem)
1201{
1202 if (mc.moving_task && current != mc.moving_task) {
1203 if (mem_cgroup_under_move(mem)) {
1204 DEFINE_WAIT(wait);
1205 prepare_to_wait(&mc.waitq, &wait, TASK_INTERRUPTIBLE);
1206 /* moving charge context might have finished. */
1207 if (mc.moving_task)
1208 schedule();
1209 finish_wait(&mc.waitq, &wait);
1210 return true;
1211 }
1212 }
1213 return false;
1214}
1215
Balbir Singhe2224322009-04-02 16:57:39 -07001216/**
Kirill A. Shutemov6a6135b2010-03-10 15:22:25 -08001217 * mem_cgroup_print_oom_info: Called from OOM with tasklist_lock held in read mode.
Balbir Singhe2224322009-04-02 16:57:39 -07001218 * @memcg: The memory cgroup that went over limit
1219 * @p: Task that is going to be killed
1220 *
1221 * NOTE: @memcg and @p's mem_cgroup can be different when hierarchy is
1222 * enabled
1223 */
1224void mem_cgroup_print_oom_info(struct mem_cgroup *memcg, struct task_struct *p)
1225{
1226 struct cgroup *task_cgrp;
1227 struct cgroup *mem_cgrp;
1228 /*
1229 * Need a buffer in BSS, can't rely on allocations. The code relies
1230 * on the assumption that OOM is serialized for memory controller.
1231 * If this assumption is broken, revisit this code.
1232 */
1233 static char memcg_name[PATH_MAX];
1234 int ret;
1235
Daisuke Nishimurad31f56d2009-12-15 16:47:12 -08001236 if (!memcg || !p)
Balbir Singhe2224322009-04-02 16:57:39 -07001237 return;
1238
1239
1240 rcu_read_lock();
1241
1242 mem_cgrp = memcg->css.cgroup;
1243 task_cgrp = task_cgroup(p, mem_cgroup_subsys_id);
1244
1245 ret = cgroup_path(task_cgrp, memcg_name, PATH_MAX);
1246 if (ret < 0) {
1247 /*
1248 * Unfortunately, we are unable to convert to a useful name
1249 * But we'll still print out the usage information
1250 */
1251 rcu_read_unlock();
1252 goto done;
1253 }
1254 rcu_read_unlock();
1255
1256 printk(KERN_INFO "Task in %s killed", memcg_name);
1257
1258 rcu_read_lock();
1259 ret = cgroup_path(mem_cgrp, memcg_name, PATH_MAX);
1260 if (ret < 0) {
1261 rcu_read_unlock();
1262 goto done;
1263 }
1264 rcu_read_unlock();
1265
1266 /*
1267 * Continues from above, so we don't need an KERN_ level
1268 */
1269 printk(KERN_CONT " as a result of limit of %s\n", memcg_name);
1270done:
1271
1272 printk(KERN_INFO "memory: usage %llukB, limit %llukB, failcnt %llu\n",
1273 res_counter_read_u64(&memcg->res, RES_USAGE) >> 10,
1274 res_counter_read_u64(&memcg->res, RES_LIMIT) >> 10,
1275 res_counter_read_u64(&memcg->res, RES_FAILCNT));
1276 printk(KERN_INFO "memory+swap: usage %llukB, limit %llukB, "
1277 "failcnt %llu\n",
1278 res_counter_read_u64(&memcg->memsw, RES_USAGE) >> 10,
1279 res_counter_read_u64(&memcg->memsw, RES_LIMIT) >> 10,
1280 res_counter_read_u64(&memcg->memsw, RES_FAILCNT));
1281}
1282
KAMEZAWA Hiroyuki81d39c22009-04-02 16:57:36 -07001283/*
1284 * This function returns the number of memcg under hierarchy tree. Returns
1285 * 1(self count) if no children.
1286 */
1287static int mem_cgroup_count_children(struct mem_cgroup *mem)
1288{
1289 int num = 0;
KAMEZAWA Hiroyuki7d74b062010-10-27 15:33:41 -07001290 struct mem_cgroup *iter;
1291
1292 for_each_mem_cgroup_tree(iter, mem)
1293 num++;
KAMEZAWA Hiroyuki81d39c22009-04-02 16:57:36 -07001294 return num;
1295}
1296
Balbir Singh6d61ef42009-01-07 18:08:06 -08001297/*
David Rientjesa63d83f2010-08-09 17:19:46 -07001298 * Return the memory (and swap, if configured) limit for a memcg.
1299 */
1300u64 mem_cgroup_get_limit(struct mem_cgroup *memcg)
1301{
1302 u64 limit;
1303 u64 memsw;
1304
Johannes Weinerf3e8eb72011-01-13 15:47:39 -08001305 limit = res_counter_read_u64(&memcg->res, RES_LIMIT);
1306 limit += total_swap_pages << PAGE_SHIFT;
1307
David Rientjesa63d83f2010-08-09 17:19:46 -07001308 memsw = res_counter_read_u64(&memcg->memsw, RES_LIMIT);
1309 /*
1310 * If memsw is finite and limits the amount of swap space available
1311 * to this memcg, return that limit.
1312 */
1313 return min(limit, memsw);
1314}
1315
1316/*
KAMEZAWA Hiroyuki04046e12009-04-02 16:57:33 -07001317 * Visit the first child (need not be the first child as per the ordering
1318 * of the cgroup list, since we track last_scanned_child) of @mem and use
1319 * that to reclaim free pages from.
1320 */
1321static struct mem_cgroup *
1322mem_cgroup_select_victim(struct mem_cgroup *root_mem)
1323{
1324 struct mem_cgroup *ret = NULL;
1325 struct cgroup_subsys_state *css;
1326 int nextid, found;
1327
1328 if (!root_mem->use_hierarchy) {
1329 css_get(&root_mem->css);
1330 ret = root_mem;
1331 }
1332
1333 while (!ret) {
1334 rcu_read_lock();
1335 nextid = root_mem->last_scanned_child + 1;
1336 css = css_get_next(&mem_cgroup_subsys, nextid, &root_mem->css,
1337 &found);
1338 if (css && css_tryget(css))
1339 ret = container_of(css, struct mem_cgroup, css);
1340
1341 rcu_read_unlock();
1342 /* Updates scanning parameter */
1343 spin_lock(&root_mem->reclaim_param_lock);
1344 if (!css) {
1345 /* this means start scan from ID:1 */
1346 root_mem->last_scanned_child = 0;
1347 } else
1348 root_mem->last_scanned_child = found;
1349 spin_unlock(&root_mem->reclaim_param_lock);
1350 }
1351
1352 return ret;
1353}
1354
1355/*
1356 * Scan the hierarchy if needed to reclaim memory. We remember the last child
1357 * we reclaimed from, so that we don't end up penalizing one child extensively
1358 * based on its position in the children list.
Balbir Singh6d61ef42009-01-07 18:08:06 -08001359 *
1360 * root_mem is the original ancestor that we've been reclaim from.
KAMEZAWA Hiroyuki04046e12009-04-02 16:57:33 -07001361 *
1362 * We give up and return to the caller when we visit root_mem twice.
1363 * (other groups can be removed while we're walking....)
KAMEZAWA Hiroyuki81d39c22009-04-02 16:57:36 -07001364 *
1365 * If shrink==true, for avoiding to free too much, this returns immedieately.
Balbir Singh6d61ef42009-01-07 18:08:06 -08001366 */
1367static int mem_cgroup_hierarchical_reclaim(struct mem_cgroup *root_mem,
Balbir Singh4e416952009-09-23 15:56:39 -07001368 struct zone *zone,
Balbir Singh75822b42009-09-23 15:56:38 -07001369 gfp_t gfp_mask,
1370 unsigned long reclaim_options)
Balbir Singh6d61ef42009-01-07 18:08:06 -08001371{
KAMEZAWA Hiroyuki04046e12009-04-02 16:57:33 -07001372 struct mem_cgroup *victim;
1373 int ret, total = 0;
1374 int loop = 0;
Balbir Singh75822b42009-09-23 15:56:38 -07001375 bool noswap = reclaim_options & MEM_CGROUP_RECLAIM_NOSWAP;
1376 bool shrink = reclaim_options & MEM_CGROUP_RECLAIM_SHRINK;
Balbir Singh4e416952009-09-23 15:56:39 -07001377 bool check_soft = reclaim_options & MEM_CGROUP_RECLAIM_SOFT;
1378 unsigned long excess = mem_cgroup_get_excess(root_mem);
Balbir Singh6d61ef42009-01-07 18:08:06 -08001379
KAMEZAWA Hiroyuki22a668d2009-06-17 16:27:19 -07001380 /* If memsw_is_minimum==1, swap-out is of-no-use. */
1381 if (root_mem->memsw_is_minimum)
1382 noswap = true;
1383
Balbir Singh4e416952009-09-23 15:56:39 -07001384 while (1) {
KAMEZAWA Hiroyuki04046e12009-04-02 16:57:33 -07001385 victim = mem_cgroup_select_victim(root_mem);
Balbir Singh4e416952009-09-23 15:56:39 -07001386 if (victim == root_mem) {
KAMEZAWA Hiroyuki04046e12009-04-02 16:57:33 -07001387 loop++;
KAMEZAWA Hiroyukicdec2e42009-12-15 16:47:08 -08001388 if (loop >= 1)
1389 drain_all_stock_async();
Balbir Singh4e416952009-09-23 15:56:39 -07001390 if (loop >= 2) {
1391 /*
1392 * If we have not been able to reclaim
1393 * anything, it might because there are
1394 * no reclaimable pages under this hierarchy
1395 */
1396 if (!check_soft || !total) {
1397 css_put(&victim->css);
1398 break;
1399 }
1400 /*
1401 * We want to do more targetted reclaim.
1402 * excess >> 2 is not to excessive so as to
1403 * reclaim too much, nor too less that we keep
1404 * coming back to reclaim from this cgroup
1405 */
1406 if (total >= (excess >> 2) ||
1407 (loop > MEM_CGROUP_MAX_RECLAIM_LOOPS)) {
1408 css_put(&victim->css);
1409 break;
1410 }
1411 }
1412 }
KAMEZAWA Hiroyukic62b1a32010-03-10 15:22:29 -08001413 if (!mem_cgroup_local_usage(victim)) {
KAMEZAWA Hiroyuki04046e12009-04-02 16:57:33 -07001414 /* this cgroup's local usage == 0 */
1415 css_put(&victim->css);
Balbir Singh6d61ef42009-01-07 18:08:06 -08001416 continue;
1417 }
KAMEZAWA Hiroyuki04046e12009-04-02 16:57:33 -07001418 /* we use swappiness of local cgroup */
Balbir Singh4e416952009-09-23 15:56:39 -07001419 if (check_soft)
1420 ret = mem_cgroup_shrink_node_zone(victim, gfp_mask,
KOSAKI Motohiro14fec792010-08-10 18:03:05 -07001421 noswap, get_swappiness(victim), zone);
Balbir Singh4e416952009-09-23 15:56:39 -07001422 else
1423 ret = try_to_free_mem_cgroup_pages(victim, gfp_mask,
1424 noswap, get_swappiness(victim));
KAMEZAWA Hiroyuki04046e12009-04-02 16:57:33 -07001425 css_put(&victim->css);
KAMEZAWA Hiroyuki81d39c22009-04-02 16:57:36 -07001426 /*
1427 * At shrinking usage, we can't check we should stop here or
1428 * reclaim more. It's depends on callers. last_scanned_child
1429 * will work enough for keeping fairness under tree.
1430 */
1431 if (shrink)
1432 return ret;
KAMEZAWA Hiroyuki04046e12009-04-02 16:57:33 -07001433 total += ret;
Balbir Singh4e416952009-09-23 15:56:39 -07001434 if (check_soft) {
1435 if (res_counter_check_under_soft_limit(&root_mem->res))
1436 return total;
1437 } else if (mem_cgroup_check_under_limit(root_mem))
KAMEZAWA Hiroyuki04046e12009-04-02 16:57:33 -07001438 return 1 + total;
Balbir Singh6d61ef42009-01-07 18:08:06 -08001439 }
KAMEZAWA Hiroyuki04046e12009-04-02 16:57:33 -07001440 return total;
Balbir Singh6d61ef42009-01-07 18:08:06 -08001441}
1442
KAMEZAWA Hiroyuki867578c2010-03-10 15:22:39 -08001443/*
1444 * Check OOM-Killer is already running under our hierarchy.
1445 * If someone is running, return false.
1446 */
1447static bool mem_cgroup_oom_lock(struct mem_cgroup *mem)
1448{
KAMEZAWA Hiroyuki7d74b062010-10-27 15:33:41 -07001449 int x, lock_count = 0;
1450 struct mem_cgroup *iter;
KAMEZAWA Hiroyukia636b322009-01-07 18:08:08 -08001451
KAMEZAWA Hiroyuki7d74b062010-10-27 15:33:41 -07001452 for_each_mem_cgroup_tree(iter, mem) {
1453 x = atomic_inc_return(&iter->oom_lock);
1454 lock_count = max(x, lock_count);
1455 }
KAMEZAWA Hiroyuki867578c2010-03-10 15:22:39 -08001456
1457 if (lock_count == 1)
1458 return true;
1459 return false;
KAMEZAWA Hiroyukia636b322009-01-07 18:08:08 -08001460}
KAMEZAWA Hiroyuki0b7f5692009-04-02 16:57:38 -07001461
KAMEZAWA Hiroyuki7d74b062010-10-27 15:33:41 -07001462static int mem_cgroup_oom_unlock(struct mem_cgroup *mem)
KAMEZAWA Hiroyuki0b7f5692009-04-02 16:57:38 -07001463{
KAMEZAWA Hiroyuki7d74b062010-10-27 15:33:41 -07001464 struct mem_cgroup *iter;
1465
KAMEZAWA Hiroyuki867578c2010-03-10 15:22:39 -08001466 /*
1467 * When a new child is created while the hierarchy is under oom,
1468 * mem_cgroup_oom_lock() may not be called. We have to use
1469 * atomic_add_unless() here.
1470 */
KAMEZAWA Hiroyuki7d74b062010-10-27 15:33:41 -07001471 for_each_mem_cgroup_tree(iter, mem)
1472 atomic_add_unless(&iter->oom_lock, -1, 0);
KAMEZAWA Hiroyuki0b7f5692009-04-02 16:57:38 -07001473 return 0;
1474}
1475
KAMEZAWA Hiroyuki867578c2010-03-10 15:22:39 -08001476
1477static DEFINE_MUTEX(memcg_oom_mutex);
1478static DECLARE_WAIT_QUEUE_HEAD(memcg_oom_waitq);
1479
KAMEZAWA Hiroyukidc98df52010-05-26 14:42:36 -07001480struct oom_wait_info {
1481 struct mem_cgroup *mem;
1482 wait_queue_t wait;
1483};
1484
1485static int memcg_oom_wake_function(wait_queue_t *wait,
1486 unsigned mode, int sync, void *arg)
1487{
1488 struct mem_cgroup *wake_mem = (struct mem_cgroup *)arg;
1489 struct oom_wait_info *oom_wait_info;
1490
1491 oom_wait_info = container_of(wait, struct oom_wait_info, wait);
1492
1493 if (oom_wait_info->mem == wake_mem)
1494 goto wakeup;
1495 /* if no hierarchy, no match */
1496 if (!oom_wait_info->mem->use_hierarchy || !wake_mem->use_hierarchy)
1497 return 0;
1498 /*
1499 * Both of oom_wait_info->mem and wake_mem are stable under us.
1500 * Then we can use css_is_ancestor without taking care of RCU.
1501 */
1502 if (!css_is_ancestor(&oom_wait_info->mem->css, &wake_mem->css) &&
1503 !css_is_ancestor(&wake_mem->css, &oom_wait_info->mem->css))
1504 return 0;
1505
1506wakeup:
1507 return autoremove_wake_function(wait, mode, sync, arg);
1508}
1509
1510static void memcg_wakeup_oom(struct mem_cgroup *mem)
1511{
1512 /* for filtering, pass "mem" as argument. */
1513 __wake_up(&memcg_oom_waitq, TASK_NORMAL, 0, mem);
1514}
1515
KAMEZAWA Hiroyuki3c11ecf2010-05-26 14:42:37 -07001516static void memcg_oom_recover(struct mem_cgroup *mem)
1517{
KAMEZAWA Hiroyuki2bd9bb22010-08-10 18:02:58 -07001518 if (mem && atomic_read(&mem->oom_lock))
KAMEZAWA Hiroyuki3c11ecf2010-05-26 14:42:37 -07001519 memcg_wakeup_oom(mem);
1520}
1521
KAMEZAWA Hiroyuki867578c2010-03-10 15:22:39 -08001522/*
1523 * try to call OOM killer. returns false if we should exit memory-reclaim loop.
1524 */
1525bool mem_cgroup_handle_oom(struct mem_cgroup *mem, gfp_t mask)
1526{
KAMEZAWA Hiroyukidc98df52010-05-26 14:42:36 -07001527 struct oom_wait_info owait;
KAMEZAWA Hiroyuki3c11ecf2010-05-26 14:42:37 -07001528 bool locked, need_to_kill;
KAMEZAWA Hiroyuki867578c2010-03-10 15:22:39 -08001529
KAMEZAWA Hiroyukidc98df52010-05-26 14:42:36 -07001530 owait.mem = mem;
1531 owait.wait.flags = 0;
1532 owait.wait.func = memcg_oom_wake_function;
1533 owait.wait.private = current;
1534 INIT_LIST_HEAD(&owait.wait.task_list);
KAMEZAWA Hiroyuki3c11ecf2010-05-26 14:42:37 -07001535 need_to_kill = true;
KAMEZAWA Hiroyuki867578c2010-03-10 15:22:39 -08001536 /* At first, try to OOM lock hierarchy under mem.*/
1537 mutex_lock(&memcg_oom_mutex);
1538 locked = mem_cgroup_oom_lock(mem);
1539 /*
1540 * Even if signal_pending(), we can't quit charge() loop without
1541 * accounting. So, UNINTERRUPTIBLE is appropriate. But SIGKILL
1542 * under OOM is always welcomed, use TASK_KILLABLE here.
1543 */
KAMEZAWA Hiroyuki3c11ecf2010-05-26 14:42:37 -07001544 prepare_to_wait(&memcg_oom_waitq, &owait.wait, TASK_KILLABLE);
1545 if (!locked || mem->oom_kill_disable)
1546 need_to_kill = false;
1547 if (locked)
KAMEZAWA Hiroyuki9490ff22010-05-26 14:42:36 -07001548 mem_cgroup_oom_notify(mem);
KAMEZAWA Hiroyuki867578c2010-03-10 15:22:39 -08001549 mutex_unlock(&memcg_oom_mutex);
1550
KAMEZAWA Hiroyuki3c11ecf2010-05-26 14:42:37 -07001551 if (need_to_kill) {
1552 finish_wait(&memcg_oom_waitq, &owait.wait);
KAMEZAWA Hiroyuki867578c2010-03-10 15:22:39 -08001553 mem_cgroup_out_of_memory(mem, mask);
KAMEZAWA Hiroyuki3c11ecf2010-05-26 14:42:37 -07001554 } else {
KAMEZAWA Hiroyuki867578c2010-03-10 15:22:39 -08001555 schedule();
KAMEZAWA Hiroyukidc98df52010-05-26 14:42:36 -07001556 finish_wait(&memcg_oom_waitq, &owait.wait);
KAMEZAWA Hiroyuki867578c2010-03-10 15:22:39 -08001557 }
1558 mutex_lock(&memcg_oom_mutex);
1559 mem_cgroup_oom_unlock(mem);
KAMEZAWA Hiroyukidc98df52010-05-26 14:42:36 -07001560 memcg_wakeup_oom(mem);
KAMEZAWA Hiroyuki867578c2010-03-10 15:22:39 -08001561 mutex_unlock(&memcg_oom_mutex);
1562
1563 if (test_thread_flag(TIF_MEMDIE) || fatal_signal_pending(current))
1564 return false;
1565 /* Give chance to dying process */
1566 schedule_timeout(1);
1567 return true;
KAMEZAWA Hiroyuki0b7f5692009-04-02 16:57:38 -07001568}
1569
Balbir Singhd69b0422009-06-17 16:26:34 -07001570/*
1571 * Currently used to update mapped file statistics, but the routine can be
1572 * generalized to update other statistics as well.
KAMEZAWA Hiroyuki32047e22010-10-27 15:33:40 -07001573 *
1574 * Notes: Race condition
1575 *
1576 * We usually use page_cgroup_lock() for accessing page_cgroup member but
1577 * it tends to be costly. But considering some conditions, we doesn't need
1578 * to do so _always_.
1579 *
1580 * Considering "charge", lock_page_cgroup() is not required because all
1581 * file-stat operations happen after a page is attached to radix-tree. There
1582 * are no race with "charge".
1583 *
1584 * Considering "uncharge", we know that memcg doesn't clear pc->mem_cgroup
1585 * at "uncharge" intentionally. So, we always see valid pc->mem_cgroup even
1586 * if there are race with "uncharge". Statistics itself is properly handled
1587 * by flags.
1588 *
1589 * Considering "move", this is an only case we see a race. To make the race
1590 * small, we check MEM_CGROUP_ON_MOVE percpu value and detect there are
1591 * possibility of race condition. If there is, we take a lock.
Balbir Singhd69b0422009-06-17 16:26:34 -07001592 */
KAMEZAWA Hiroyuki26174ef2010-10-27 15:33:43 -07001593
Greg Thelen2a7106f2011-01-13 15:47:37 -08001594void mem_cgroup_update_page_stat(struct page *page,
1595 enum mem_cgroup_page_stat_item idx, int val)
Balbir Singhd69b0422009-06-17 16:26:34 -07001596{
1597 struct mem_cgroup *mem;
KAMEZAWA Hiroyuki32047e22010-10-27 15:33:40 -07001598 struct page_cgroup *pc = lookup_page_cgroup(page);
1599 bool need_unlock = false;
KAMEZAWA Hiroyukidbd4ea72011-01-13 15:47:38 -08001600 unsigned long uninitialized_var(flags);
Balbir Singhd69b0422009-06-17 16:26:34 -07001601
Balbir Singhd69b0422009-06-17 16:26:34 -07001602 if (unlikely(!pc))
1603 return;
1604
KAMEZAWA Hiroyuki32047e22010-10-27 15:33:40 -07001605 rcu_read_lock();
Balbir Singhd69b0422009-06-17 16:26:34 -07001606 mem = pc->mem_cgroup;
KAMEZAWA Hiroyuki32047e22010-10-27 15:33:40 -07001607 if (unlikely(!mem || !PageCgroupUsed(pc)))
1608 goto out;
1609 /* pc->mem_cgroup is unstable ? */
KAMEZAWA Hiroyukica3e0212011-01-20 14:44:24 -08001610 if (unlikely(mem_cgroup_stealed(mem)) || PageTransHuge(page)) {
KAMEZAWA Hiroyuki32047e22010-10-27 15:33:40 -07001611 /* take a lock against to access pc->mem_cgroup */
KAMEZAWA Hiroyukidbd4ea72011-01-13 15:47:38 -08001612 move_lock_page_cgroup(pc, &flags);
KAMEZAWA Hiroyuki32047e22010-10-27 15:33:40 -07001613 need_unlock = true;
1614 mem = pc->mem_cgroup;
1615 if (!mem || !PageCgroupUsed(pc))
1616 goto out;
1617 }
KAMEZAWA Hiroyuki26174ef2010-10-27 15:33:43 -07001618
KAMEZAWA Hiroyuki26174ef2010-10-27 15:33:43 -07001619 switch (idx) {
Greg Thelen2a7106f2011-01-13 15:47:37 -08001620 case MEMCG_NR_FILE_MAPPED:
KAMEZAWA Hiroyuki26174ef2010-10-27 15:33:43 -07001621 if (val > 0)
1622 SetPageCgroupFileMapped(pc);
1623 else if (!page_mapped(page))
KAMEZAWA Hiroyuki0c270f82010-10-27 15:33:39 -07001624 ClearPageCgroupFileMapped(pc);
Greg Thelen2a7106f2011-01-13 15:47:37 -08001625 idx = MEM_CGROUP_STAT_FILE_MAPPED;
KAMEZAWA Hiroyuki26174ef2010-10-27 15:33:43 -07001626 break;
1627 default:
1628 BUG();
KAMEZAWA Hiroyuki8725d542010-04-06 14:35:05 -07001629 }
Balbir Singhd69b0422009-06-17 16:26:34 -07001630
Greg Thelen2a7106f2011-01-13 15:47:37 -08001631 this_cpu_add(mem->stat->count[idx], val);
1632
KAMEZAWA Hiroyuki32047e22010-10-27 15:33:40 -07001633out:
1634 if (unlikely(need_unlock))
KAMEZAWA Hiroyukidbd4ea72011-01-13 15:47:38 -08001635 move_unlock_page_cgroup(pc, &flags);
KAMEZAWA Hiroyuki32047e22010-10-27 15:33:40 -07001636 rcu_read_unlock();
1637 return;
Balbir Singhd69b0422009-06-17 16:26:34 -07001638}
Greg Thelen2a7106f2011-01-13 15:47:37 -08001639EXPORT_SYMBOL(mem_cgroup_update_page_stat);
KAMEZAWA Hiroyuki26174ef2010-10-27 15:33:43 -07001640
KAMEZAWA Hiroyukif817ed42009-01-07 18:07:53 -08001641/*
KAMEZAWA Hiroyukicdec2e42009-12-15 16:47:08 -08001642 * size of first charge trial. "32" comes from vmscan.c's magic value.
1643 * TODO: maybe necessary to use big numbers in big irons.
1644 */
1645#define CHARGE_SIZE (32 * PAGE_SIZE)
1646struct memcg_stock_pcp {
1647 struct mem_cgroup *cached; /* this never be root cgroup */
1648 int charge;
1649 struct work_struct work;
1650};
1651static DEFINE_PER_CPU(struct memcg_stock_pcp, memcg_stock);
1652static atomic_t memcg_drain_count;
1653
1654/*
1655 * Try to consume stocked charge on this cpu. If success, PAGE_SIZE is consumed
1656 * from local stock and true is returned. If the stock is 0 or charges from a
1657 * cgroup which is not current target, returns false. This stock will be
1658 * refilled.
1659 */
1660static bool consume_stock(struct mem_cgroup *mem)
1661{
1662 struct memcg_stock_pcp *stock;
1663 bool ret = true;
1664
1665 stock = &get_cpu_var(memcg_stock);
1666 if (mem == stock->cached && stock->charge)
1667 stock->charge -= PAGE_SIZE;
1668 else /* need to call res_counter_charge */
1669 ret = false;
1670 put_cpu_var(memcg_stock);
1671 return ret;
1672}
1673
1674/*
1675 * Returns stocks cached in percpu to res_counter and reset cached information.
1676 */
1677static void drain_stock(struct memcg_stock_pcp *stock)
1678{
1679 struct mem_cgroup *old = stock->cached;
1680
1681 if (stock->charge) {
1682 res_counter_uncharge(&old->res, stock->charge);
1683 if (do_swap_account)
1684 res_counter_uncharge(&old->memsw, stock->charge);
1685 }
1686 stock->cached = NULL;
1687 stock->charge = 0;
1688}
1689
1690/*
1691 * This must be called under preempt disabled or must be called by
1692 * a thread which is pinned to local cpu.
1693 */
1694static void drain_local_stock(struct work_struct *dummy)
1695{
1696 struct memcg_stock_pcp *stock = &__get_cpu_var(memcg_stock);
1697 drain_stock(stock);
1698}
1699
1700/*
1701 * Cache charges(val) which is from res_counter, to local per_cpu area.
Greg Thelen320cc512010-03-15 15:27:28 +01001702 * This will be consumed by consume_stock() function, later.
KAMEZAWA Hiroyukicdec2e42009-12-15 16:47:08 -08001703 */
1704static void refill_stock(struct mem_cgroup *mem, int val)
1705{
1706 struct memcg_stock_pcp *stock = &get_cpu_var(memcg_stock);
1707
1708 if (stock->cached != mem) { /* reset if necessary */
1709 drain_stock(stock);
1710 stock->cached = mem;
1711 }
1712 stock->charge += val;
1713 put_cpu_var(memcg_stock);
1714}
1715
1716/*
1717 * Tries to drain stocked charges in other cpus. This function is asynchronous
1718 * and just put a work per cpu for draining localy on each cpu. Caller can
1719 * expects some charges will be back to res_counter later but cannot wait for
1720 * it.
1721 */
1722static void drain_all_stock_async(void)
1723{
1724 int cpu;
1725 /* This function is for scheduling "drain" in asynchronous way.
1726 * The result of "drain" is not directly handled by callers. Then,
1727 * if someone is calling drain, we don't have to call drain more.
1728 * Anyway, WORK_STRUCT_PENDING check in queue_work_on() will catch if
1729 * there is a race. We just do loose check here.
1730 */
1731 if (atomic_read(&memcg_drain_count))
1732 return;
1733 /* Notify other cpus that system-wide "drain" is running */
1734 atomic_inc(&memcg_drain_count);
1735 get_online_cpus();
1736 for_each_online_cpu(cpu) {
1737 struct memcg_stock_pcp *stock = &per_cpu(memcg_stock, cpu);
1738 schedule_work_on(cpu, &stock->work);
1739 }
1740 put_online_cpus();
1741 atomic_dec(&memcg_drain_count);
1742 /* We don't wait for flush_work */
1743}
1744
1745/* This is a synchronous drain interface. */
1746static void drain_all_stock_sync(void)
1747{
1748 /* called when force_empty is called */
1749 atomic_inc(&memcg_drain_count);
1750 schedule_on_each_cpu(drain_local_stock);
1751 atomic_dec(&memcg_drain_count);
1752}
1753
KAMEZAWA Hiroyuki711d3d22010-10-27 15:33:42 -07001754/*
1755 * This function drains percpu counter value from DEAD cpu and
1756 * move it to local cpu. Note that this function can be preempted.
1757 */
1758static void mem_cgroup_drain_pcp_counter(struct mem_cgroup *mem, int cpu)
1759{
1760 int i;
1761
1762 spin_lock(&mem->pcp_counter_lock);
1763 for (i = 0; i < MEM_CGROUP_STAT_DATA; i++) {
1764 s64 x = per_cpu(mem->stat->count[i], cpu);
1765
1766 per_cpu(mem->stat->count[i], cpu) = 0;
1767 mem->nocpu_base.count[i] += x;
1768 }
KAMEZAWA Hiroyuki1489eba2010-10-27 15:33:42 -07001769 /* need to clear ON_MOVE value, works as a kind of lock. */
1770 per_cpu(mem->stat->count[MEM_CGROUP_ON_MOVE], cpu) = 0;
1771 spin_unlock(&mem->pcp_counter_lock);
1772}
1773
1774static void synchronize_mem_cgroup_on_move(struct mem_cgroup *mem, int cpu)
1775{
1776 int idx = MEM_CGROUP_ON_MOVE;
1777
1778 spin_lock(&mem->pcp_counter_lock);
1779 per_cpu(mem->stat->count[idx], cpu) = mem->nocpu_base.count[idx];
KAMEZAWA Hiroyuki711d3d22010-10-27 15:33:42 -07001780 spin_unlock(&mem->pcp_counter_lock);
1781}
1782
1783static int __cpuinit memcg_cpu_hotplug_callback(struct notifier_block *nb,
KAMEZAWA Hiroyukicdec2e42009-12-15 16:47:08 -08001784 unsigned long action,
1785 void *hcpu)
1786{
1787 int cpu = (unsigned long)hcpu;
1788 struct memcg_stock_pcp *stock;
KAMEZAWA Hiroyuki711d3d22010-10-27 15:33:42 -07001789 struct mem_cgroup *iter;
KAMEZAWA Hiroyukicdec2e42009-12-15 16:47:08 -08001790
KAMEZAWA Hiroyuki1489eba2010-10-27 15:33:42 -07001791 if ((action == CPU_ONLINE)) {
1792 for_each_mem_cgroup_all(iter)
1793 synchronize_mem_cgroup_on_move(iter, cpu);
1794 return NOTIFY_OK;
1795 }
1796
KAMEZAWA Hiroyuki711d3d22010-10-27 15:33:42 -07001797 if ((action != CPU_DEAD) || action != CPU_DEAD_FROZEN)
KAMEZAWA Hiroyukicdec2e42009-12-15 16:47:08 -08001798 return NOTIFY_OK;
KAMEZAWA Hiroyuki711d3d22010-10-27 15:33:42 -07001799
1800 for_each_mem_cgroup_all(iter)
1801 mem_cgroup_drain_pcp_counter(iter, cpu);
1802
KAMEZAWA Hiroyukicdec2e42009-12-15 16:47:08 -08001803 stock = &per_cpu(memcg_stock, cpu);
1804 drain_stock(stock);
1805 return NOTIFY_OK;
1806}
1807
KAMEZAWA Hiroyuki4b534332010-08-10 18:02:57 -07001808
1809/* See __mem_cgroup_try_charge() for details */
1810enum {
1811 CHARGE_OK, /* success */
1812 CHARGE_RETRY, /* need to retry but retry is not bad */
1813 CHARGE_NOMEM, /* we can't do more. return -ENOMEM */
1814 CHARGE_WOULDBLOCK, /* GFP_WAIT wasn't set and no enough res. */
1815 CHARGE_OOM_DIE, /* the current is killed because of OOM */
1816};
1817
1818static int __mem_cgroup_do_charge(struct mem_cgroup *mem, gfp_t gfp_mask,
1819 int csize, bool oom_check)
1820{
1821 struct mem_cgroup *mem_over_limit;
1822 struct res_counter *fail_res;
1823 unsigned long flags = 0;
1824 int ret;
1825
1826 ret = res_counter_charge(&mem->res, csize, &fail_res);
1827
1828 if (likely(!ret)) {
1829 if (!do_swap_account)
1830 return CHARGE_OK;
1831 ret = res_counter_charge(&mem->memsw, csize, &fail_res);
1832 if (likely(!ret))
1833 return CHARGE_OK;
1834
1835 mem_over_limit = mem_cgroup_from_res_counter(fail_res, memsw);
1836 flags |= MEM_CGROUP_RECLAIM_NOSWAP;
1837 } else
1838 mem_over_limit = mem_cgroup_from_res_counter(fail_res, res);
1839
1840 if (csize > PAGE_SIZE) /* change csize and retry */
1841 return CHARGE_RETRY;
1842
1843 if (!(gfp_mask & __GFP_WAIT))
1844 return CHARGE_WOULDBLOCK;
1845
1846 ret = mem_cgroup_hierarchical_reclaim(mem_over_limit, NULL,
1847 gfp_mask, flags);
1848 /*
1849 * try_to_free_mem_cgroup_pages() might not give us a full
1850 * picture of reclaim. Some pages are reclaimed and might be
1851 * moved to swap cache or just unmapped from the cgroup.
1852 * Check the limit again to see if the reclaim reduced the
1853 * current usage of the cgroup before giving up
1854 */
1855 if (ret || mem_cgroup_check_under_limit(mem_over_limit))
1856 return CHARGE_RETRY;
1857
1858 /*
1859 * At task move, charge accounts can be doubly counted. So, it's
1860 * better to wait until the end of task_move if something is going on.
1861 */
1862 if (mem_cgroup_wait_acct_move(mem_over_limit))
1863 return CHARGE_RETRY;
1864
1865 /* If we don't need to call oom-killer at el, return immediately */
1866 if (!oom_check)
1867 return CHARGE_NOMEM;
1868 /* check OOM */
1869 if (!mem_cgroup_handle_oom(mem_over_limit, gfp_mask))
1870 return CHARGE_OOM_DIE;
1871
1872 return CHARGE_RETRY;
1873}
1874
KAMEZAWA Hiroyukicdec2e42009-12-15 16:47:08 -08001875/*
KAMEZAWA Hiroyukif817ed42009-01-07 18:07:53 -08001876 * Unlike exported interface, "oom" parameter is added. if oom==true,
1877 * oom-killer can be invoked.
Balbir Singh8a9f3cc2008-02-07 00:13:53 -08001878 */
KAMEZAWA Hiroyukif817ed42009-01-07 18:07:53 -08001879static int __mem_cgroup_try_charge(struct mm_struct *mm,
Andrea Arcangeliec168512011-01-13 15:46:56 -08001880 gfp_t gfp_mask,
1881 struct mem_cgroup **memcg, bool oom,
1882 int page_size)
Balbir Singh8a9f3cc2008-02-07 00:13:53 -08001883{
KAMEZAWA Hiroyuki4b534332010-08-10 18:02:57 -07001884 int nr_oom_retries = MEM_CGROUP_RECLAIM_RETRIES;
1885 struct mem_cgroup *mem = NULL;
1886 int ret;
Andrea Arcangeliec168512011-01-13 15:46:56 -08001887 int csize = max(CHARGE_SIZE, (unsigned long) page_size);
KAMEZAWA Hiroyukia636b322009-01-07 18:08:08 -08001888
KAMEZAWA Hiroyuki867578c2010-03-10 15:22:39 -08001889 /*
1890 * Unlike gloval-vm's OOM-kill, we're not in memory shortage
1891 * in system level. So, allow to go ahead dying process in addition to
1892 * MEMDIE process.
1893 */
1894 if (unlikely(test_thread_flag(TIF_MEMDIE)
1895 || fatal_signal_pending(current)))
1896 goto bypass;
KAMEZAWA Hiroyukia636b322009-01-07 18:08:08 -08001897
Balbir Singh8a9f3cc2008-02-07 00:13:53 -08001898 /*
Hugh Dickins3be91272008-02-07 00:14:19 -08001899 * We always charge the cgroup the mm_struct belongs to.
1900 * The mm_struct's mem_cgroup changes on task migration if the
Balbir Singh8a9f3cc2008-02-07 00:13:53 -08001901 * thread group leader migrates. It's possible that mm is not
1902 * set, if so charge the init_mm (happens for pagecache usage).
1903 */
KAMEZAWA Hiroyukif75ca962010-08-10 18:03:02 -07001904 if (!*memcg && !mm)
1905 goto bypass;
1906again:
1907 if (*memcg) { /* css should be a valid one */
KAMEZAWA Hiroyuki4b534332010-08-10 18:02:57 -07001908 mem = *memcg;
KAMEZAWA Hiroyukif75ca962010-08-10 18:03:02 -07001909 VM_BUG_ON(css_is_removed(&mem->css));
1910 if (mem_cgroup_is_root(mem))
1911 goto done;
Andrea Arcangeliec168512011-01-13 15:46:56 -08001912 if (page_size == PAGE_SIZE && consume_stock(mem))
KAMEZAWA Hiroyukif75ca962010-08-10 18:03:02 -07001913 goto done;
KAMEZAWA Hiroyuki7a81b882009-01-07 18:07:48 -08001914 css_get(&mem->css);
KAMEZAWA Hiroyuki4b534332010-08-10 18:02:57 -07001915 } else {
KAMEZAWA Hiroyukif75ca962010-08-10 18:03:02 -07001916 struct task_struct *p;
KAMEZAWA Hiroyuki54595fe2009-01-07 18:08:33 -08001917
KAMEZAWA Hiroyukif75ca962010-08-10 18:03:02 -07001918 rcu_read_lock();
1919 p = rcu_dereference(mm->owner);
KAMEZAWA Hiroyukif75ca962010-08-10 18:03:02 -07001920 /*
KAMEZAWA Hiroyukiebb76ce2010-12-29 14:07:11 -08001921 * Because we don't have task_lock(), "p" can exit.
1922 * In that case, "mem" can point to root or p can be NULL with
1923 * race with swapoff. Then, we have small risk of mis-accouning.
1924 * But such kind of mis-account by race always happens because
1925 * we don't have cgroup_mutex(). It's overkill and we allo that
1926 * small race, here.
1927 * (*) swapoff at el will charge against mm-struct not against
1928 * task-struct. So, mm->owner can be NULL.
KAMEZAWA Hiroyukif75ca962010-08-10 18:03:02 -07001929 */
1930 mem = mem_cgroup_from_task(p);
KAMEZAWA Hiroyukiebb76ce2010-12-29 14:07:11 -08001931 if (!mem || mem_cgroup_is_root(mem)) {
KAMEZAWA Hiroyukif75ca962010-08-10 18:03:02 -07001932 rcu_read_unlock();
1933 goto done;
1934 }
Andrea Arcangeliec168512011-01-13 15:46:56 -08001935 if (page_size == PAGE_SIZE && consume_stock(mem)) {
KAMEZAWA Hiroyukif75ca962010-08-10 18:03:02 -07001936 /*
1937 * It seems dagerous to access memcg without css_get().
1938 * But considering how consume_stok works, it's not
1939 * necessary. If consume_stock success, some charges
1940 * from this memcg are cached on this cpu. So, we
1941 * don't need to call css_get()/css_tryget() before
1942 * calling consume_stock().
1943 */
1944 rcu_read_unlock();
1945 goto done;
1946 }
1947 /* after here, we may be blocked. we need to get refcnt */
1948 if (!css_tryget(&mem->css)) {
1949 rcu_read_unlock();
1950 goto again;
1951 }
1952 rcu_read_unlock();
1953 }
Balbir Singh8a9f3cc2008-02-07 00:13:53 -08001954
KAMEZAWA Hiroyuki4b534332010-08-10 18:02:57 -07001955 do {
1956 bool oom_check;
KAMEZAWA Hiroyuki7a81b882009-01-07 18:07:48 -08001957
KAMEZAWA Hiroyuki4b534332010-08-10 18:02:57 -07001958 /* If killed, bypass charge */
KAMEZAWA Hiroyukif75ca962010-08-10 18:03:02 -07001959 if (fatal_signal_pending(current)) {
1960 css_put(&mem->css);
KAMEZAWA Hiroyuki4b534332010-08-10 18:02:57 -07001961 goto bypass;
KAMEZAWA Hiroyukif75ca962010-08-10 18:03:02 -07001962 }
KAMEZAWA Hiroyukicdec2e42009-12-15 16:47:08 -08001963
KAMEZAWA Hiroyuki4b534332010-08-10 18:02:57 -07001964 oom_check = false;
1965 if (oom && !nr_oom_retries) {
1966 oom_check = true;
1967 nr_oom_retries = MEM_CGROUP_RECLAIM_RETRIES;
1968 }
Balbir Singh6d61ef42009-01-07 18:08:06 -08001969
KAMEZAWA Hiroyuki4b534332010-08-10 18:02:57 -07001970 ret = __mem_cgroup_do_charge(mem, gfp_mask, csize, oom_check);
1971
1972 switch (ret) {
1973 case CHARGE_OK:
1974 break;
1975 case CHARGE_RETRY: /* not in OOM situation but retry */
Andrea Arcangeliec168512011-01-13 15:46:56 -08001976 csize = page_size;
KAMEZAWA Hiroyukif75ca962010-08-10 18:03:02 -07001977 css_put(&mem->css);
1978 mem = NULL;
1979 goto again;
KAMEZAWA Hiroyuki4b534332010-08-10 18:02:57 -07001980 case CHARGE_WOULDBLOCK: /* !__GFP_WAIT */
KAMEZAWA Hiroyukif75ca962010-08-10 18:03:02 -07001981 css_put(&mem->css);
KAMEZAWA Hiroyuki7a81b882009-01-07 18:07:48 -08001982 goto nomem;
KAMEZAWA Hiroyuki4b534332010-08-10 18:02:57 -07001983 case CHARGE_NOMEM: /* OOM routine works */
KAMEZAWA Hiroyukif75ca962010-08-10 18:03:02 -07001984 if (!oom) {
1985 css_put(&mem->css);
KAMEZAWA Hiroyuki867578c2010-03-10 15:22:39 -08001986 goto nomem;
KAMEZAWA Hiroyukif75ca962010-08-10 18:03:02 -07001987 }
KAMEZAWA Hiroyuki4b534332010-08-10 18:02:57 -07001988 /* If oom, we never return -ENOMEM */
1989 nr_oom_retries--;
1990 break;
1991 case CHARGE_OOM_DIE: /* Killed by OOM Killer */
KAMEZAWA Hiroyukif75ca962010-08-10 18:03:02 -07001992 css_put(&mem->css);
KAMEZAWA Hiroyuki867578c2010-03-10 15:22:39 -08001993 goto bypass;
Balbir Singh66e17072008-02-07 00:13:56 -08001994 }
KAMEZAWA Hiroyuki4b534332010-08-10 18:02:57 -07001995 } while (ret != CHARGE_OK);
1996
Andrea Arcangeliec168512011-01-13 15:46:56 -08001997 if (csize > page_size)
1998 refill_stock(mem, csize - page_size);
KAMEZAWA Hiroyukif75ca962010-08-10 18:03:02 -07001999 css_put(&mem->css);
Balbir Singh0c3e73e2009-09-23 15:56:42 -07002000done:
KAMEZAWA Hiroyukif75ca962010-08-10 18:03:02 -07002001 *memcg = mem;
KAMEZAWA Hiroyuki7a81b882009-01-07 18:07:48 -08002002 return 0;
2003nomem:
KAMEZAWA Hiroyukif75ca962010-08-10 18:03:02 -07002004 *memcg = NULL;
KAMEZAWA Hiroyuki7a81b882009-01-07 18:07:48 -08002005 return -ENOMEM;
KAMEZAWA Hiroyuki867578c2010-03-10 15:22:39 -08002006bypass:
2007 *memcg = NULL;
2008 return 0;
KAMEZAWA Hiroyuki7a81b882009-01-07 18:07:48 -08002009}
Balbir Singh8a9f3cc2008-02-07 00:13:53 -08002010
KAMEZAWA Hiroyukia3b2d692009-04-02 16:57:45 -07002011/*
Daisuke Nishimuraa3032a22009-12-15 16:47:10 -08002012 * Somemtimes we have to undo a charge we got by try_charge().
2013 * This function is for that and do uncharge, put css's refcnt.
2014 * gotten by try_charge().
2015 */
Daisuke Nishimura854ffa82010-03-10 15:22:15 -08002016static void __mem_cgroup_cancel_charge(struct mem_cgroup *mem,
2017 unsigned long count)
Daisuke Nishimuraa3032a22009-12-15 16:47:10 -08002018{
2019 if (!mem_cgroup_is_root(mem)) {
Daisuke Nishimura854ffa82010-03-10 15:22:15 -08002020 res_counter_uncharge(&mem->res, PAGE_SIZE * count);
Daisuke Nishimuraa3032a22009-12-15 16:47:10 -08002021 if (do_swap_account)
Daisuke Nishimura854ffa82010-03-10 15:22:15 -08002022 res_counter_uncharge(&mem->memsw, PAGE_SIZE * count);
Daisuke Nishimuraa3032a22009-12-15 16:47:10 -08002023 }
Daisuke Nishimura854ffa82010-03-10 15:22:15 -08002024}
2025
Andrea Arcangeliec168512011-01-13 15:46:56 -08002026static void mem_cgroup_cancel_charge(struct mem_cgroup *mem,
2027 int page_size)
Daisuke Nishimura854ffa82010-03-10 15:22:15 -08002028{
Andrea Arcangeliec168512011-01-13 15:46:56 -08002029 __mem_cgroup_cancel_charge(mem, page_size >> PAGE_SHIFT);
Daisuke Nishimuraa3032a22009-12-15 16:47:10 -08002030}
2031
2032/*
KAMEZAWA Hiroyukia3b2d692009-04-02 16:57:45 -07002033 * A helper function to get mem_cgroup from ID. must be called under
2034 * rcu_read_lock(). The caller must check css_is_removed() or some if
2035 * it's concern. (dropping refcnt from swap can be called against removed
2036 * memcg.)
2037 */
2038static struct mem_cgroup *mem_cgroup_lookup(unsigned short id)
2039{
2040 struct cgroup_subsys_state *css;
2041
2042 /* ID 0 is unused ID */
2043 if (!id)
2044 return NULL;
2045 css = css_lookup(&mem_cgroup_subsys, id);
2046 if (!css)
2047 return NULL;
2048 return container_of(css, struct mem_cgroup, css);
2049}
2050
Wu Fengguange42d9d52009-12-16 12:19:59 +01002051struct mem_cgroup *try_get_mem_cgroup_from_page(struct page *page)
KAMEZAWA Hiroyukib5a84312009-01-07 18:08:35 -08002052{
Wu Fengguange42d9d52009-12-16 12:19:59 +01002053 struct mem_cgroup *mem = NULL;
Daisuke Nishimura3c776e62009-04-02 16:57:43 -07002054 struct page_cgroup *pc;
KAMEZAWA Hiroyukia3b2d692009-04-02 16:57:45 -07002055 unsigned short id;
KAMEZAWA Hiroyukib5a84312009-01-07 18:08:35 -08002056 swp_entry_t ent;
2057
Daisuke Nishimura3c776e62009-04-02 16:57:43 -07002058 VM_BUG_ON(!PageLocked(page));
2059
Daisuke Nishimura3c776e62009-04-02 16:57:43 -07002060 pc = lookup_page_cgroup(page);
Daisuke Nishimurac0bd3f62009-04-30 15:08:11 -07002061 lock_page_cgroup(pc);
KAMEZAWA Hiroyukia3b2d692009-04-02 16:57:45 -07002062 if (PageCgroupUsed(pc)) {
Daisuke Nishimura3c776e62009-04-02 16:57:43 -07002063 mem = pc->mem_cgroup;
KAMEZAWA Hiroyukia3b2d692009-04-02 16:57:45 -07002064 if (mem && !css_tryget(&mem->css))
2065 mem = NULL;
Wu Fengguange42d9d52009-12-16 12:19:59 +01002066 } else if (PageSwapCache(page)) {
Daisuke Nishimura3c776e62009-04-02 16:57:43 -07002067 ent.val = page_private(page);
KAMEZAWA Hiroyukia3b2d692009-04-02 16:57:45 -07002068 id = lookup_swap_cgroup(ent);
2069 rcu_read_lock();
2070 mem = mem_cgroup_lookup(id);
2071 if (mem && !css_tryget(&mem->css))
2072 mem = NULL;
2073 rcu_read_unlock();
Daisuke Nishimura3c776e62009-04-02 16:57:43 -07002074 }
Daisuke Nishimurac0bd3f62009-04-30 15:08:11 -07002075 unlock_page_cgroup(pc);
KAMEZAWA Hiroyukib5a84312009-01-07 18:08:35 -08002076 return mem;
2077}
2078
KAMEZAWA Hiroyukica3e0212011-01-20 14:44:24 -08002079static void __mem_cgroup_commit_charge(struct mem_cgroup *mem,
2080 struct page_cgroup *pc,
2081 enum charge_type ctype,
2082 int page_size)
KAMEZAWA Hiroyuki7a81b882009-01-07 18:07:48 -08002083{
KAMEZAWA Hiroyukica3e0212011-01-20 14:44:24 -08002084 int nr_pages = page_size >> PAGE_SHIFT;
2085
2086 /* try_charge() can return NULL to *memcg, taking care of it. */
2087 if (!mem)
2088 return;
2089
2090 lock_page_cgroup(pc);
2091 if (unlikely(PageCgroupUsed(pc))) {
2092 unlock_page_cgroup(pc);
2093 mem_cgroup_cancel_charge(mem, page_size);
2094 return;
2095 }
2096 /*
2097 * we don't need page_cgroup_lock about tail pages, becase they are not
2098 * accessed by any other context at this point.
2099 */
Balbir Singh8a9f3cc2008-02-07 00:13:53 -08002100 pc->mem_cgroup = mem;
KAMEZAWA Hiroyuki261fb612009-09-23 15:56:33 -07002101 /*
2102 * We access a page_cgroup asynchronously without lock_page_cgroup().
2103 * Especially when a page_cgroup is taken from a page, pc->mem_cgroup
2104 * is accessed after testing USED bit. To make pc->mem_cgroup visible
2105 * before USED bit, we need memory barrier here.
2106 * See mem_cgroup_add_lru_list(), etc.
2107 */
KAMEZAWA Hiroyuki08e552c2009-01-07 18:08:01 -08002108 smp_wmb();
Balbir Singh4b3bde42009-09-23 15:56:32 -07002109 switch (ctype) {
2110 case MEM_CGROUP_CHARGE_TYPE_CACHE:
2111 case MEM_CGROUP_CHARGE_TYPE_SHMEM:
2112 SetPageCgroupCache(pc);
2113 SetPageCgroupUsed(pc);
2114 break;
2115 case MEM_CGROUP_CHARGE_TYPE_MAPPED:
2116 ClearPageCgroupCache(pc);
2117 SetPageCgroupUsed(pc);
2118 break;
2119 default:
2120 break;
2121 }
Hugh Dickins3be91272008-02-07 00:14:19 -08002122
KAMEZAWA Hiroyukica3e0212011-01-20 14:44:24 -08002123 mem_cgroup_charge_statistics(mem, PageCgroupCache(pc), nr_pages);
KAMEZAWA Hiroyuki52d4b9a2008-10-18 20:28:16 -07002124 unlock_page_cgroup(pc);
KAMEZAWA Hiroyuki430e48632010-03-10 15:22:30 -08002125 /*
2126 * "charge_statistics" updated event counter. Then, check it.
2127 * Insert ancestor (and ancestor's ancestors), to softlimit RB-tree.
2128 * if they exceeds softlimit.
2129 */
KAMEZAWA Hiroyukid2265e62010-03-10 15:22:31 -08002130 memcg_check_events(mem, pc->page);
Balbir Singh8a9f3cc2008-02-07 00:13:53 -08002131}
2132
KAMEZAWA Hiroyukica3e0212011-01-20 14:44:24 -08002133#ifdef CONFIG_TRANSPARENT_HUGEPAGE
2134
2135#define PCGF_NOCOPY_AT_SPLIT ((1 << PCG_LOCK) | (1 << PCG_MOVE_LOCK) |\
2136 (1 << PCG_ACCT_LRU) | (1 << PCG_MIGRATION))
2137/*
2138 * Because tail pages are not marked as "used", set it. We're under
2139 * zone->lru_lock, 'splitting on pmd' and compund_lock.
2140 */
2141void mem_cgroup_split_huge_fixup(struct page *head, struct page *tail)
2142{
2143 struct page_cgroup *head_pc = lookup_page_cgroup(head);
2144 struct page_cgroup *tail_pc = lookup_page_cgroup(tail);
2145 unsigned long flags;
2146
2147 /*
KAMEZAWA Hiroyukiece35ca2011-01-20 14:44:24 -08002148 * We have no races with charge/uncharge but will have races with
KAMEZAWA Hiroyukica3e0212011-01-20 14:44:24 -08002149 * page state accounting.
2150 */
2151 move_lock_page_cgroup(head_pc, &flags);
2152
2153 tail_pc->mem_cgroup = head_pc->mem_cgroup;
2154 smp_wmb(); /* see __commit_charge() */
KAMEZAWA Hiroyukiece35ca2011-01-20 14:44:24 -08002155 if (PageCgroupAcctLRU(head_pc)) {
2156 enum lru_list lru;
2157 struct mem_cgroup_per_zone *mz;
2158
2159 /*
2160 * LRU flags cannot be copied because we need to add tail
2161 *.page to LRU by generic call and our hook will be called.
2162 * We hold lru_lock, then, reduce counter directly.
2163 */
2164 lru = page_lru(head);
2165 mz = page_cgroup_zoneinfo(head_pc);
2166 MEM_CGROUP_ZSTAT(mz, lru) -= 1;
2167 }
KAMEZAWA Hiroyukica3e0212011-01-20 14:44:24 -08002168 tail_pc->flags = head_pc->flags & ~PCGF_NOCOPY_AT_SPLIT;
2169 move_unlock_page_cgroup(head_pc, &flags);
2170}
2171#endif
2172
KAMEZAWA Hiroyukif817ed42009-01-07 18:07:53 -08002173/**
Daisuke Nishimura57f9fd72009-12-15 16:47:11 -08002174 * __mem_cgroup_move_account - move account of the page
KAMEZAWA Hiroyukif817ed42009-01-07 18:07:53 -08002175 * @pc: page_cgroup of the page.
2176 * @from: mem_cgroup which the page is moved from.
2177 * @to: mem_cgroup which the page is moved to. @from != @to.
Daisuke Nishimura854ffa82010-03-10 15:22:15 -08002178 * @uncharge: whether we should call uncharge and css_put against @from.
KAMEZAWA Hiroyukif817ed42009-01-07 18:07:53 -08002179 *
2180 * The caller must confirm following.
KAMEZAWA Hiroyuki08e552c2009-01-07 18:08:01 -08002181 * - page is not on LRU (isolate_page() is useful.)
Daisuke Nishimura57f9fd72009-12-15 16:47:11 -08002182 * - the pc is locked, used, and ->mem_cgroup points to @from.
KAMEZAWA Hiroyukif817ed42009-01-07 18:07:53 -08002183 *
Daisuke Nishimura854ffa82010-03-10 15:22:15 -08002184 * This function doesn't do "charge" nor css_get to new cgroup. It should be
2185 * done by a caller(__mem_cgroup_try_charge would be usefull). If @uncharge is
2186 * true, this function does "uncharge" from old cgroup, but it doesn't if
2187 * @uncharge is false, so a caller should do "uncharge".
KAMEZAWA Hiroyukif817ed42009-01-07 18:07:53 -08002188 */
2189
Daisuke Nishimura57f9fd72009-12-15 16:47:11 -08002190static void __mem_cgroup_move_account(struct page_cgroup *pc,
KAMEZAWA Hiroyuki987eba62011-01-20 14:44:25 -08002191 struct mem_cgroup *from, struct mem_cgroup *to, bool uncharge,
2192 int charge_size)
KAMEZAWA Hiroyukif817ed42009-01-07 18:07:53 -08002193{
KAMEZAWA Hiroyuki987eba62011-01-20 14:44:25 -08002194 int nr_pages = charge_size >> PAGE_SHIFT;
2195
KAMEZAWA Hiroyukif817ed42009-01-07 18:07:53 -08002196 VM_BUG_ON(from == to);
KAMEZAWA Hiroyuki08e552c2009-01-07 18:08:01 -08002197 VM_BUG_ON(PageLRU(pc->page));
Kirill A. Shutemov112bc2e2010-11-24 12:56:58 -08002198 VM_BUG_ON(!page_is_cgroup_locked(pc));
Daisuke Nishimura57f9fd72009-12-15 16:47:11 -08002199 VM_BUG_ON(!PageCgroupUsed(pc));
2200 VM_BUG_ON(pc->mem_cgroup != from);
KAMEZAWA Hiroyukif817ed42009-01-07 18:07:53 -08002201
KAMEZAWA Hiroyuki8725d542010-04-06 14:35:05 -07002202 if (PageCgroupFileMapped(pc)) {
KAMEZAWA Hiroyukic62b1a32010-03-10 15:22:29 -08002203 /* Update mapped_file data for mem_cgroup */
2204 preempt_disable();
2205 __this_cpu_dec(from->stat->count[MEM_CGROUP_STAT_FILE_MAPPED]);
2206 __this_cpu_inc(to->stat->count[MEM_CGROUP_STAT_FILE_MAPPED]);
2207 preempt_enable();
Balbir Singhd69b0422009-06-17 16:26:34 -07002208 }
KAMEZAWA Hiroyuki987eba62011-01-20 14:44:25 -08002209 mem_cgroup_charge_statistics(from, PageCgroupCache(pc), -nr_pages);
Daisuke Nishimura854ffa82010-03-10 15:22:15 -08002210 if (uncharge)
2211 /* This is not "cancel", but cancel_charge does all we need. */
KAMEZAWA Hiroyuki987eba62011-01-20 14:44:25 -08002212 mem_cgroup_cancel_charge(from, charge_size);
Balbir Singhd69b0422009-06-17 16:26:34 -07002213
Daisuke Nishimura854ffa82010-03-10 15:22:15 -08002214 /* caller should have done css_get */
KAMEZAWA Hiroyuki08e552c2009-01-07 18:08:01 -08002215 pc->mem_cgroup = to;
KAMEZAWA Hiroyuki987eba62011-01-20 14:44:25 -08002216 mem_cgroup_charge_statistics(to, PageCgroupCache(pc), nr_pages);
KAMEZAWA Hiroyuki88703262009-07-29 15:04:06 -07002217 /*
2218 * We charges against "to" which may not have any tasks. Then, "to"
2219 * can be under rmdir(). But in current implementation, caller of
Daisuke Nishimura4ffef5f2010-03-10 15:22:14 -08002220 * this function is just force_empty() and move charge, so it's
2221 * garanteed that "to" is never removed. So, we don't check rmdir
2222 * status here.
KAMEZAWA Hiroyuki88703262009-07-29 15:04:06 -07002223 */
Daisuke Nishimura57f9fd72009-12-15 16:47:11 -08002224}
2225
2226/*
2227 * check whether the @pc is valid for moving account and call
2228 * __mem_cgroup_move_account()
2229 */
2230static int mem_cgroup_move_account(struct page_cgroup *pc,
KAMEZAWA Hiroyuki987eba62011-01-20 14:44:25 -08002231 struct mem_cgroup *from, struct mem_cgroup *to,
2232 bool uncharge, int charge_size)
Daisuke Nishimura57f9fd72009-12-15 16:47:11 -08002233{
2234 int ret = -EINVAL;
KAMEZAWA Hiroyukidbd4ea72011-01-13 15:47:38 -08002235 unsigned long flags;
2236
KAMEZAWA Hiroyuki987eba62011-01-20 14:44:25 -08002237 if ((charge_size > PAGE_SIZE) && !PageTransHuge(pc->page))
2238 return -EBUSY;
2239
Daisuke Nishimura57f9fd72009-12-15 16:47:11 -08002240 lock_page_cgroup(pc);
2241 if (PageCgroupUsed(pc) && pc->mem_cgroup == from) {
KAMEZAWA Hiroyukidbd4ea72011-01-13 15:47:38 -08002242 move_lock_page_cgroup(pc, &flags);
KAMEZAWA Hiroyuki987eba62011-01-20 14:44:25 -08002243 __mem_cgroup_move_account(pc, from, to, uncharge, charge_size);
KAMEZAWA Hiroyukidbd4ea72011-01-13 15:47:38 -08002244 move_unlock_page_cgroup(pc, &flags);
Daisuke Nishimura57f9fd72009-12-15 16:47:11 -08002245 ret = 0;
2246 }
2247 unlock_page_cgroup(pc);
KAMEZAWA Hiroyukid2265e62010-03-10 15:22:31 -08002248 /*
2249 * check events
2250 */
2251 memcg_check_events(to, pc->page);
2252 memcg_check_events(from, pc->page);
KAMEZAWA Hiroyukif817ed42009-01-07 18:07:53 -08002253 return ret;
2254}
2255
2256/*
2257 * move charges to its parent.
2258 */
2259
2260static int mem_cgroup_move_parent(struct page_cgroup *pc,
2261 struct mem_cgroup *child,
2262 gfp_t gfp_mask)
2263{
KAMEZAWA Hiroyuki08e552c2009-01-07 18:08:01 -08002264 struct page *page = pc->page;
KAMEZAWA Hiroyukif817ed42009-01-07 18:07:53 -08002265 struct cgroup *cg = child->css.cgroup;
2266 struct cgroup *pcg = cg->parent;
2267 struct mem_cgroup *parent;
KAMEZAWA Hiroyuki987eba62011-01-20 14:44:25 -08002268 int charge = PAGE_SIZE;
2269 unsigned long flags;
KAMEZAWA Hiroyukif817ed42009-01-07 18:07:53 -08002270 int ret;
2271
2272 /* Is ROOT ? */
2273 if (!pcg)
2274 return -EINVAL;
2275
Daisuke Nishimura57f9fd72009-12-15 16:47:11 -08002276 ret = -EBUSY;
2277 if (!get_page_unless_zero(page))
2278 goto out;
2279 if (isolate_lru_page(page))
2280 goto put;
KAMEZAWA Hiroyuki987eba62011-01-20 14:44:25 -08002281 /* The page is isolated from LRU and we have no race with splitting */
2282 charge = PAGE_SIZE << compound_order(page);
KAMEZAWA Hiroyuki08e552c2009-01-07 18:08:01 -08002283
KAMEZAWA Hiroyukif817ed42009-01-07 18:07:53 -08002284 parent = mem_cgroup_from_cont(pcg);
KAMEZAWA Hiroyuki987eba62011-01-20 14:44:25 -08002285 ret = __mem_cgroup_try_charge(NULL, gfp_mask, &parent, false, charge);
KAMEZAWA Hiroyukia636b322009-01-07 18:08:08 -08002286 if (ret || !parent)
Daisuke Nishimura57f9fd72009-12-15 16:47:11 -08002287 goto put_back;
KAMEZAWA Hiroyuki08e552c2009-01-07 18:08:01 -08002288
KAMEZAWA Hiroyuki987eba62011-01-20 14:44:25 -08002289 if (charge > PAGE_SIZE)
2290 flags = compound_lock_irqsave(page);
2291
2292 ret = mem_cgroup_move_account(pc, child, parent, true, charge);
Daisuke Nishimura854ffa82010-03-10 15:22:15 -08002293 if (ret)
KAMEZAWA Hiroyuki987eba62011-01-20 14:44:25 -08002294 mem_cgroup_cancel_charge(parent, charge);
Daisuke Nishimura57f9fd72009-12-15 16:47:11 -08002295put_back:
KAMEZAWA Hiroyuki987eba62011-01-20 14:44:25 -08002296 if (charge > PAGE_SIZE)
2297 compound_unlock_irqrestore(page, flags);
KAMEZAWA Hiroyuki08e552c2009-01-07 18:08:01 -08002298 putback_lru_page(page);
Daisuke Nishimura57f9fd72009-12-15 16:47:11 -08002299put:
Daisuke Nishimura40d58132009-01-15 13:51:12 -08002300 put_page(page);
Daisuke Nishimura57f9fd72009-12-15 16:47:11 -08002301out:
KAMEZAWA Hiroyukif817ed42009-01-07 18:07:53 -08002302 return ret;
2303}
2304
KAMEZAWA Hiroyuki7a81b882009-01-07 18:07:48 -08002305/*
2306 * Charge the memory controller for page usage.
2307 * Return
2308 * 0 if the charge was successful
2309 * < 0 if the cgroup is over its limit
2310 */
2311static int mem_cgroup_charge_common(struct page *page, struct mm_struct *mm,
Daisuke Nishimura73045c42010-08-10 18:02:59 -07002312 gfp_t gfp_mask, enum charge_type ctype)
KAMEZAWA Hiroyuki7a81b882009-01-07 18:07:48 -08002313{
Daisuke Nishimura73045c42010-08-10 18:02:59 -07002314 struct mem_cgroup *mem = NULL;
KAMEZAWA Hiroyuki7a81b882009-01-07 18:07:48 -08002315 struct page_cgroup *pc;
2316 int ret;
Andrea Arcangeliec168512011-01-13 15:46:56 -08002317 int page_size = PAGE_SIZE;
2318
Andrea Arcangeli37c2ac72011-01-13 15:47:16 -08002319 if (PageTransHuge(page)) {
Andrea Arcangeliec168512011-01-13 15:46:56 -08002320 page_size <<= compound_order(page);
Andrea Arcangeli37c2ac72011-01-13 15:47:16 -08002321 VM_BUG_ON(!PageTransHuge(page));
2322 }
KAMEZAWA Hiroyuki7a81b882009-01-07 18:07:48 -08002323
2324 pc = lookup_page_cgroup(page);
2325 /* can happen at boot */
2326 if (unlikely(!pc))
2327 return 0;
2328 prefetchw(pc);
2329
Andrea Arcangeliec168512011-01-13 15:46:56 -08002330 ret = __mem_cgroup_try_charge(mm, gfp_mask, &mem, true, page_size);
KAMEZAWA Hiroyukia636b322009-01-07 18:08:08 -08002331 if (ret || !mem)
KAMEZAWA Hiroyuki7a81b882009-01-07 18:07:48 -08002332 return ret;
2333
Andrea Arcangeliec168512011-01-13 15:46:56 -08002334 __mem_cgroup_commit_charge(mem, pc, ctype, page_size);
KAMEZAWA Hiroyuki7a81b882009-01-07 18:07:48 -08002335 return 0;
2336}
2337
2338int mem_cgroup_newpage_charge(struct page *page,
2339 struct mm_struct *mm, gfp_t gfp_mask)
KAMEZAWA Hiroyuki217bc312008-02-07 00:14:17 -08002340{
Hirokazu Takahashif8d66542009-01-07 18:08:02 -08002341 if (mem_cgroup_disabled())
Li Zefancede86a2008-07-25 01:47:18 -07002342 return 0;
KAMEZAWA Hiroyuki69029cd2008-07-25 01:47:14 -07002343 /*
2344 * If already mapped, we don't have to account.
2345 * If page cache, page->mapping has address_space.
2346 * But page->mapping may have out-of-use anon_vma pointer,
2347 * detecit it by PageAnon() check. newly-mapped-anon's page->mapping
2348 * is NULL.
2349 */
2350 if (page_mapped(page) || (page->mapping && !PageAnon(page)))
2351 return 0;
2352 if (unlikely(!mm))
2353 mm = &init_mm;
KAMEZAWA Hiroyuki217bc312008-02-07 00:14:17 -08002354 return mem_cgroup_charge_common(page, mm, gfp_mask,
Daisuke Nishimura73045c42010-08-10 18:02:59 -07002355 MEM_CGROUP_CHARGE_TYPE_MAPPED);
KAMEZAWA Hiroyuki217bc312008-02-07 00:14:17 -08002356}
2357
Daisuke Nishimura83aae4c2009-04-02 16:57:48 -07002358static void
2359__mem_cgroup_commit_charge_swapin(struct page *page, struct mem_cgroup *ptr,
2360 enum charge_type ctype);
2361
Balbir Singhe1a1cd52008-02-07 00:14:02 -08002362int mem_cgroup_cache_charge(struct page *page, struct mm_struct *mm,
2363 gfp_t gfp_mask)
Balbir Singh8697d332008-02-07 00:13:59 -08002364{
KAMEZAWA Hiroyukib5a84312009-01-07 18:08:35 -08002365 int ret;
2366
Hirokazu Takahashif8d66542009-01-07 18:08:02 -08002367 if (mem_cgroup_disabled())
Li Zefancede86a2008-07-25 01:47:18 -07002368 return 0;
KAMEZAWA Hiroyuki52d4b9a2008-10-18 20:28:16 -07002369 if (PageCompound(page))
2370 return 0;
KAMEZAWA Hiroyukiaccf1632008-07-25 01:47:17 -07002371 /*
2372 * Corner case handling. This is called from add_to_page_cache()
2373 * in usual. But some FS (shmem) precharges this page before calling it
2374 * and call add_to_page_cache() with GFP_NOWAIT.
2375 *
2376 * For GFP_NOWAIT case, the page may be pre-charged before calling
2377 * add_to_page_cache(). (See shmem.c) check it here and avoid to call
2378 * charge twice. (It works but has to pay a bit larger cost.)
KAMEZAWA Hiroyukib5a84312009-01-07 18:08:35 -08002379 * And when the page is SwapCache, it should take swap information
2380 * into account. This is under lock_page() now.
KAMEZAWA Hiroyukiaccf1632008-07-25 01:47:17 -07002381 */
2382 if (!(gfp_mask & __GFP_WAIT)) {
2383 struct page_cgroup *pc;
2384
KAMEZAWA Hiroyuki52d4b9a2008-10-18 20:28:16 -07002385 pc = lookup_page_cgroup(page);
2386 if (!pc)
2387 return 0;
2388 lock_page_cgroup(pc);
2389 if (PageCgroupUsed(pc)) {
2390 unlock_page_cgroup(pc);
KAMEZAWA Hiroyukiaccf1632008-07-25 01:47:17 -07002391 return 0;
2392 }
KAMEZAWA Hiroyuki52d4b9a2008-10-18 20:28:16 -07002393 unlock_page_cgroup(pc);
KAMEZAWA Hiroyukiaccf1632008-07-25 01:47:17 -07002394 }
2395
Daisuke Nishimura73045c42010-08-10 18:02:59 -07002396 if (unlikely(!mm))
Balbir Singh8697d332008-02-07 00:13:59 -08002397 mm = &init_mm;
KAMEZAWA Hiroyukiaccf1632008-07-25 01:47:17 -07002398
KAMEZAWA Hiroyukic05555b2008-10-18 20:28:11 -07002399 if (page_is_file_cache(page))
2400 return mem_cgroup_charge_common(page, mm, gfp_mask,
Daisuke Nishimura73045c42010-08-10 18:02:59 -07002401 MEM_CGROUP_CHARGE_TYPE_CACHE);
KAMEZAWA Hiroyukib5a84312009-01-07 18:08:35 -08002402
Daisuke Nishimura83aae4c2009-04-02 16:57:48 -07002403 /* shmem */
2404 if (PageSwapCache(page)) {
Daisuke Nishimura73045c42010-08-10 18:02:59 -07002405 struct mem_cgroup *mem = NULL;
2406
Daisuke Nishimura83aae4c2009-04-02 16:57:48 -07002407 ret = mem_cgroup_try_charge_swapin(mm, page, gfp_mask, &mem);
2408 if (!ret)
2409 __mem_cgroup_commit_charge_swapin(page, mem,
2410 MEM_CGROUP_CHARGE_TYPE_SHMEM);
2411 } else
2412 ret = mem_cgroup_charge_common(page, mm, gfp_mask,
Daisuke Nishimura73045c42010-08-10 18:02:59 -07002413 MEM_CGROUP_CHARGE_TYPE_SHMEM);
KAMEZAWA Hiroyukib5a84312009-01-07 18:08:35 -08002414
KAMEZAWA Hiroyukib5a84312009-01-07 18:08:35 -08002415 return ret;
KAMEZAWA Hiroyukie8589cc2008-07-25 01:47:10 -07002416}
2417
KAMEZAWA Hiroyuki54595fe2009-01-07 18:08:33 -08002418/*
2419 * While swap-in, try_charge -> commit or cancel, the page is locked.
2420 * And when try_charge() successfully returns, one refcnt to memcg without
Uwe Kleine-König21ae2952009-10-07 15:21:09 +02002421 * struct page_cgroup is acquired. This refcnt will be consumed by
KAMEZAWA Hiroyuki54595fe2009-01-07 18:08:33 -08002422 * "commit()" or removed by "cancel()"
2423 */
KAMEZAWA Hiroyuki8c7c6e32009-01-07 18:08:00 -08002424int mem_cgroup_try_charge_swapin(struct mm_struct *mm,
2425 struct page *page,
2426 gfp_t mask, struct mem_cgroup **ptr)
2427{
2428 struct mem_cgroup *mem;
KAMEZAWA Hiroyuki54595fe2009-01-07 18:08:33 -08002429 int ret;
KAMEZAWA Hiroyuki8c7c6e32009-01-07 18:08:00 -08002430
Hirokazu Takahashif8d66542009-01-07 18:08:02 -08002431 if (mem_cgroup_disabled())
KAMEZAWA Hiroyuki8c7c6e32009-01-07 18:08:00 -08002432 return 0;
2433
2434 if (!do_swap_account)
2435 goto charge_cur_mm;
KAMEZAWA Hiroyuki8c7c6e32009-01-07 18:08:00 -08002436 /*
2437 * A racing thread's fault, or swapoff, may have already updated
Hugh Dickins407f9c82009-12-14 17:59:30 -08002438 * the pte, and even removed page from swap cache: in those cases
2439 * do_swap_page()'s pte_same() test will fail; but there's also a
2440 * KSM case which does need to charge the page.
KAMEZAWA Hiroyuki8c7c6e32009-01-07 18:08:00 -08002441 */
2442 if (!PageSwapCache(page))
Hugh Dickins407f9c82009-12-14 17:59:30 -08002443 goto charge_cur_mm;
Wu Fengguange42d9d52009-12-16 12:19:59 +01002444 mem = try_get_mem_cgroup_from_page(page);
KAMEZAWA Hiroyuki54595fe2009-01-07 18:08:33 -08002445 if (!mem)
2446 goto charge_cur_mm;
KAMEZAWA Hiroyuki8c7c6e32009-01-07 18:08:00 -08002447 *ptr = mem;
Andrea Arcangeliec168512011-01-13 15:46:56 -08002448 ret = __mem_cgroup_try_charge(NULL, mask, ptr, true, PAGE_SIZE);
KAMEZAWA Hiroyuki54595fe2009-01-07 18:08:33 -08002449 css_put(&mem->css);
2450 return ret;
KAMEZAWA Hiroyuki8c7c6e32009-01-07 18:08:00 -08002451charge_cur_mm:
2452 if (unlikely(!mm))
2453 mm = &init_mm;
Andrea Arcangeliec168512011-01-13 15:46:56 -08002454 return __mem_cgroup_try_charge(mm, mask, ptr, true, PAGE_SIZE);
KAMEZAWA Hiroyuki8c7c6e32009-01-07 18:08:00 -08002455}
2456
Daisuke Nishimura83aae4c2009-04-02 16:57:48 -07002457static void
2458__mem_cgroup_commit_charge_swapin(struct page *page, struct mem_cgroup *ptr,
2459 enum charge_type ctype)
KAMEZAWA Hiroyuki7a81b882009-01-07 18:07:48 -08002460{
2461 struct page_cgroup *pc;
2462
Hirokazu Takahashif8d66542009-01-07 18:08:02 -08002463 if (mem_cgroup_disabled())
KAMEZAWA Hiroyuki7a81b882009-01-07 18:07:48 -08002464 return;
2465 if (!ptr)
2466 return;
KAMEZAWA Hiroyuki88703262009-07-29 15:04:06 -07002467 cgroup_exclude_rmdir(&ptr->css);
KAMEZAWA Hiroyuki7a81b882009-01-07 18:07:48 -08002468 pc = lookup_page_cgroup(page);
KAMEZAWA Hiroyuki544122e2009-01-07 18:08:34 -08002469 mem_cgroup_lru_del_before_commit_swapcache(page);
Andrea Arcangeliec168512011-01-13 15:46:56 -08002470 __mem_cgroup_commit_charge(ptr, pc, ctype, PAGE_SIZE);
KAMEZAWA Hiroyuki544122e2009-01-07 18:08:34 -08002471 mem_cgroup_lru_add_after_commit_swapcache(page);
KAMEZAWA Hiroyuki8c7c6e32009-01-07 18:08:00 -08002472 /*
2473 * Now swap is on-memory. This means this page may be
2474 * counted both as mem and swap....double count.
KAMEZAWA Hiroyuki03f3c432009-01-07 18:08:31 -08002475 * Fix it by uncharging from memsw. Basically, this SwapCache is stable
2476 * under lock_page(). But in do_swap_page()::memory.c, reuse_swap_page()
2477 * may call delete_from_swap_cache() before reach here.
KAMEZAWA Hiroyuki8c7c6e32009-01-07 18:08:00 -08002478 */
KAMEZAWA Hiroyuki03f3c432009-01-07 18:08:31 -08002479 if (do_swap_account && PageSwapCache(page)) {
KAMEZAWA Hiroyuki8c7c6e32009-01-07 18:08:00 -08002480 swp_entry_t ent = {.val = page_private(page)};
KAMEZAWA Hiroyukia3b2d692009-04-02 16:57:45 -07002481 unsigned short id;
KAMEZAWA Hiroyuki8c7c6e32009-01-07 18:08:00 -08002482 struct mem_cgroup *memcg;
KAMEZAWA Hiroyukia3b2d692009-04-02 16:57:45 -07002483
2484 id = swap_cgroup_record(ent, 0);
2485 rcu_read_lock();
2486 memcg = mem_cgroup_lookup(id);
KAMEZAWA Hiroyuki8c7c6e32009-01-07 18:08:00 -08002487 if (memcg) {
KAMEZAWA Hiroyukia3b2d692009-04-02 16:57:45 -07002488 /*
2489 * This recorded memcg can be obsolete one. So, avoid
2490 * calling css_tryget
2491 */
Balbir Singh0c3e73e2009-09-23 15:56:42 -07002492 if (!mem_cgroup_is_root(memcg))
KAMEZAWA Hiroyuki4e649152009-10-01 15:44:11 -07002493 res_counter_uncharge(&memcg->memsw, PAGE_SIZE);
Balbir Singh0c3e73e2009-09-23 15:56:42 -07002494 mem_cgroup_swap_statistics(memcg, false);
KAMEZAWA Hiroyuki8c7c6e32009-01-07 18:08:00 -08002495 mem_cgroup_put(memcg);
2496 }
KAMEZAWA Hiroyukia3b2d692009-04-02 16:57:45 -07002497 rcu_read_unlock();
KAMEZAWA Hiroyuki8c7c6e32009-01-07 18:08:00 -08002498 }
KAMEZAWA Hiroyuki88703262009-07-29 15:04:06 -07002499 /*
2500 * At swapin, we may charge account against cgroup which has no tasks.
2501 * So, rmdir()->pre_destroy() can be called while we do this charge.
2502 * In that case, we need to call pre_destroy() again. check it here.
2503 */
2504 cgroup_release_and_wakeup_rmdir(&ptr->css);
KAMEZAWA Hiroyuki7a81b882009-01-07 18:07:48 -08002505}
2506
Daisuke Nishimura83aae4c2009-04-02 16:57:48 -07002507void mem_cgroup_commit_charge_swapin(struct page *page, struct mem_cgroup *ptr)
2508{
2509 __mem_cgroup_commit_charge_swapin(page, ptr,
2510 MEM_CGROUP_CHARGE_TYPE_MAPPED);
2511}
2512
KAMEZAWA Hiroyuki7a81b882009-01-07 18:07:48 -08002513void mem_cgroup_cancel_charge_swapin(struct mem_cgroup *mem)
2514{
Hirokazu Takahashif8d66542009-01-07 18:08:02 -08002515 if (mem_cgroup_disabled())
KAMEZAWA Hiroyuki7a81b882009-01-07 18:07:48 -08002516 return;
2517 if (!mem)
2518 return;
Andrea Arcangeliec168512011-01-13 15:46:56 -08002519 mem_cgroup_cancel_charge(mem, PAGE_SIZE);
KAMEZAWA Hiroyuki7a81b882009-01-07 18:07:48 -08002520}
2521
KAMEZAWA Hiroyuki569b8462009-12-15 16:47:03 -08002522static void
Andrea Arcangeliec168512011-01-13 15:46:56 -08002523__do_uncharge(struct mem_cgroup *mem, const enum charge_type ctype,
2524 int page_size)
KAMEZAWA Hiroyuki569b8462009-12-15 16:47:03 -08002525{
2526 struct memcg_batch_info *batch = NULL;
2527 bool uncharge_memsw = true;
2528 /* If swapout, usage of swap doesn't decrease */
2529 if (!do_swap_account || ctype == MEM_CGROUP_CHARGE_TYPE_SWAPOUT)
2530 uncharge_memsw = false;
KAMEZAWA Hiroyuki569b8462009-12-15 16:47:03 -08002531
2532 batch = &current->memcg_batch;
2533 /*
2534 * In usual, we do css_get() when we remember memcg pointer.
2535 * But in this case, we keep res->usage until end of a series of
2536 * uncharges. Then, it's ok to ignore memcg's refcnt.
2537 */
2538 if (!batch->memcg)
2539 batch->memcg = mem;
2540 /*
KAMEZAWA Hiroyuki3c11ecf2010-05-26 14:42:37 -07002541 * do_batch > 0 when unmapping pages or inode invalidate/truncate.
2542 * In those cases, all pages freed continously can be expected to be in
2543 * the same cgroup and we have chance to coalesce uncharges.
2544 * But we do uncharge one by one if this is killed by OOM(TIF_MEMDIE)
2545 * because we want to do uncharge as soon as possible.
2546 */
2547
2548 if (!batch->do_batch || test_thread_flag(TIF_MEMDIE))
2549 goto direct_uncharge;
2550
Andrea Arcangeliec168512011-01-13 15:46:56 -08002551 if (page_size != PAGE_SIZE)
2552 goto direct_uncharge;
2553
KAMEZAWA Hiroyuki3c11ecf2010-05-26 14:42:37 -07002554 /*
KAMEZAWA Hiroyuki569b8462009-12-15 16:47:03 -08002555 * In typical case, batch->memcg == mem. This means we can
2556 * merge a series of uncharges to an uncharge of res_counter.
2557 * If not, we uncharge res_counter ony by one.
2558 */
2559 if (batch->memcg != mem)
2560 goto direct_uncharge;
2561 /* remember freed charge and uncharge it later */
2562 batch->bytes += PAGE_SIZE;
2563 if (uncharge_memsw)
2564 batch->memsw_bytes += PAGE_SIZE;
2565 return;
2566direct_uncharge:
Andrea Arcangeliec168512011-01-13 15:46:56 -08002567 res_counter_uncharge(&mem->res, page_size);
KAMEZAWA Hiroyuki569b8462009-12-15 16:47:03 -08002568 if (uncharge_memsw)
Andrea Arcangeliec168512011-01-13 15:46:56 -08002569 res_counter_uncharge(&mem->memsw, page_size);
KAMEZAWA Hiroyuki3c11ecf2010-05-26 14:42:37 -07002570 if (unlikely(batch->memcg != mem))
2571 memcg_oom_recover(mem);
KAMEZAWA Hiroyuki569b8462009-12-15 16:47:03 -08002572 return;
2573}
KAMEZAWA Hiroyuki7a81b882009-01-07 18:07:48 -08002574
Balbir Singh8697d332008-02-07 00:13:59 -08002575/*
KAMEZAWA Hiroyuki69029cd2008-07-25 01:47:14 -07002576 * uncharge if !page_mapped(page)
Balbir Singh8a9f3cc2008-02-07 00:13:53 -08002577 */
KAMEZAWA Hiroyuki8c7c6e32009-01-07 18:08:00 -08002578static struct mem_cgroup *
KAMEZAWA Hiroyuki69029cd2008-07-25 01:47:14 -07002579__mem_cgroup_uncharge_common(struct page *page, enum charge_type ctype)
Balbir Singh8a9f3cc2008-02-07 00:13:53 -08002580{
Daisuke Nishimura152c9cc2011-01-13 15:46:56 -08002581 int count;
Hugh Dickins82895462008-03-04 14:29:08 -08002582 struct page_cgroup *pc;
KAMEZAWA Hiroyuki8c7c6e32009-01-07 18:08:00 -08002583 struct mem_cgroup *mem = NULL;
Andrea Arcangeliec168512011-01-13 15:46:56 -08002584 int page_size = PAGE_SIZE;
Balbir Singh8a9f3cc2008-02-07 00:13:53 -08002585
Hirokazu Takahashif8d66542009-01-07 18:08:02 -08002586 if (mem_cgroup_disabled())
KAMEZAWA Hiroyuki8c7c6e32009-01-07 18:08:00 -08002587 return NULL;
Balbir Singh40779602008-04-04 14:29:59 -07002588
KAMEZAWA Hiroyukid13d1442009-01-07 18:07:56 -08002589 if (PageSwapCache(page))
KAMEZAWA Hiroyuki8c7c6e32009-01-07 18:08:00 -08002590 return NULL;
KAMEZAWA Hiroyukid13d1442009-01-07 18:07:56 -08002591
Andrea Arcangeli37c2ac72011-01-13 15:47:16 -08002592 if (PageTransHuge(page)) {
Andrea Arcangeliec168512011-01-13 15:46:56 -08002593 page_size <<= compound_order(page);
Andrea Arcangeli37c2ac72011-01-13 15:47:16 -08002594 VM_BUG_ON(!PageTransHuge(page));
2595 }
Andrea Arcangeliec168512011-01-13 15:46:56 -08002596
Daisuke Nishimura152c9cc2011-01-13 15:46:56 -08002597 count = page_size >> PAGE_SHIFT;
Balbir Singh8697d332008-02-07 00:13:59 -08002598 /*
Balbir Singh3c541e12008-02-07 00:14:41 -08002599 * Check if our page_cgroup is valid
Balbir Singh8697d332008-02-07 00:13:59 -08002600 */
KAMEZAWA Hiroyuki52d4b9a2008-10-18 20:28:16 -07002601 pc = lookup_page_cgroup(page);
2602 if (unlikely(!pc || !PageCgroupUsed(pc)))
KAMEZAWA Hiroyuki8c7c6e32009-01-07 18:08:00 -08002603 return NULL;
Balbir Singh8a9f3cc2008-02-07 00:13:53 -08002604
KAMEZAWA Hiroyuki52d4b9a2008-10-18 20:28:16 -07002605 lock_page_cgroup(pc);
KAMEZAWA Hiroyukid13d1442009-01-07 18:07:56 -08002606
KAMEZAWA Hiroyuki8c7c6e32009-01-07 18:08:00 -08002607 mem = pc->mem_cgroup;
2608
KAMEZAWA Hiroyukid13d1442009-01-07 18:07:56 -08002609 if (!PageCgroupUsed(pc))
2610 goto unlock_out;
2611
2612 switch (ctype) {
2613 case MEM_CGROUP_CHARGE_TYPE_MAPPED:
KAMEZAWA Hiroyuki8a9478c2009-06-17 16:27:17 -07002614 case MEM_CGROUP_CHARGE_TYPE_DROP:
akpm@linux-foundation.orgac39cf82010-05-26 14:42:46 -07002615 /* See mem_cgroup_prepare_migration() */
2616 if (page_mapped(page) || PageCgroupMigration(pc))
KAMEZAWA Hiroyukid13d1442009-01-07 18:07:56 -08002617 goto unlock_out;
2618 break;
2619 case MEM_CGROUP_CHARGE_TYPE_SWAPOUT:
2620 if (!PageAnon(page)) { /* Shared memory */
2621 if (page->mapping && !page_is_file_cache(page))
2622 goto unlock_out;
2623 } else if (page_mapped(page)) /* Anon */
2624 goto unlock_out;
2625 break;
2626 default:
2627 break;
KAMEZAWA Hiroyuki52d4b9a2008-10-18 20:28:16 -07002628 }
KAMEZAWA Hiroyukid13d1442009-01-07 18:07:56 -08002629
KAMEZAWA Hiroyukica3e0212011-01-20 14:44:24 -08002630 mem_cgroup_charge_statistics(mem, PageCgroupCache(pc), -count);
KAMEZAWA Hiroyuki04046e12009-04-02 16:57:33 -07002631
KAMEZAWA Hiroyuki52d4b9a2008-10-18 20:28:16 -07002632 ClearPageCgroupUsed(pc);
KAMEZAWA Hiroyuki544122e2009-01-07 18:08:34 -08002633 /*
2634 * pc->mem_cgroup is not cleared here. It will be accessed when it's
2635 * freed from LRU. This is safe because uncharged page is expected not
2636 * to be reused (freed soon). Exception is SwapCache, it's handled by
2637 * special functions.
2638 */
Hugh Dickinsb9c565d2008-03-04 14:29:11 -08002639
KAMEZAWA Hiroyuki52d4b9a2008-10-18 20:28:16 -07002640 unlock_page_cgroup(pc);
KAMEZAWA Hiroyukif75ca962010-08-10 18:03:02 -07002641 /*
2642 * even after unlock, we have mem->res.usage here and this memcg
2643 * will never be freed.
2644 */
KAMEZAWA Hiroyukid2265e62010-03-10 15:22:31 -08002645 memcg_check_events(mem, page);
KAMEZAWA Hiroyukif75ca962010-08-10 18:03:02 -07002646 if (do_swap_account && ctype == MEM_CGROUP_CHARGE_TYPE_SWAPOUT) {
2647 mem_cgroup_swap_statistics(mem, true);
2648 mem_cgroup_get(mem);
2649 }
2650 if (!mem_cgroup_is_root(mem))
Andrea Arcangeliec168512011-01-13 15:46:56 -08002651 __do_uncharge(mem, ctype, page_size);
KAMEZAWA Hiroyuki6d12e2d2008-02-07 00:14:31 -08002652
KAMEZAWA Hiroyuki8c7c6e32009-01-07 18:08:00 -08002653 return mem;
KAMEZAWA Hiroyukid13d1442009-01-07 18:07:56 -08002654
2655unlock_out:
2656 unlock_page_cgroup(pc);
KAMEZAWA Hiroyuki8c7c6e32009-01-07 18:08:00 -08002657 return NULL;
Balbir Singh3c541e12008-02-07 00:14:41 -08002658}
2659
KAMEZAWA Hiroyuki69029cd2008-07-25 01:47:14 -07002660void mem_cgroup_uncharge_page(struct page *page)
2661{
KAMEZAWA Hiroyuki52d4b9a2008-10-18 20:28:16 -07002662 /* early check. */
2663 if (page_mapped(page))
2664 return;
2665 if (page->mapping && !PageAnon(page))
2666 return;
KAMEZAWA Hiroyuki69029cd2008-07-25 01:47:14 -07002667 __mem_cgroup_uncharge_common(page, MEM_CGROUP_CHARGE_TYPE_MAPPED);
2668}
2669
2670void mem_cgroup_uncharge_cache_page(struct page *page)
2671{
2672 VM_BUG_ON(page_mapped(page));
KAMEZAWA Hiroyukib7abea92008-10-18 20:28:09 -07002673 VM_BUG_ON(page->mapping);
KAMEZAWA Hiroyuki69029cd2008-07-25 01:47:14 -07002674 __mem_cgroup_uncharge_common(page, MEM_CGROUP_CHARGE_TYPE_CACHE);
2675}
2676
KAMEZAWA Hiroyuki569b8462009-12-15 16:47:03 -08002677/*
2678 * Batch_start/batch_end is called in unmap_page_range/invlidate/trucate.
2679 * In that cases, pages are freed continuously and we can expect pages
2680 * are in the same memcg. All these calls itself limits the number of
2681 * pages freed at once, then uncharge_start/end() is called properly.
2682 * This may be called prural(2) times in a context,
2683 */
2684
2685void mem_cgroup_uncharge_start(void)
2686{
2687 current->memcg_batch.do_batch++;
2688 /* We can do nest. */
2689 if (current->memcg_batch.do_batch == 1) {
2690 current->memcg_batch.memcg = NULL;
2691 current->memcg_batch.bytes = 0;
2692 current->memcg_batch.memsw_bytes = 0;
2693 }
2694}
2695
2696void mem_cgroup_uncharge_end(void)
2697{
2698 struct memcg_batch_info *batch = &current->memcg_batch;
2699
2700 if (!batch->do_batch)
2701 return;
2702
2703 batch->do_batch--;
2704 if (batch->do_batch) /* If stacked, do nothing. */
2705 return;
2706
2707 if (!batch->memcg)
2708 return;
2709 /*
2710 * This "batch->memcg" is valid without any css_get/put etc...
2711 * bacause we hide charges behind us.
2712 */
2713 if (batch->bytes)
2714 res_counter_uncharge(&batch->memcg->res, batch->bytes);
2715 if (batch->memsw_bytes)
2716 res_counter_uncharge(&batch->memcg->memsw, batch->memsw_bytes);
KAMEZAWA Hiroyuki3c11ecf2010-05-26 14:42:37 -07002717 memcg_oom_recover(batch->memcg);
KAMEZAWA Hiroyuki569b8462009-12-15 16:47:03 -08002718 /* forget this pointer (for sanity check) */
2719 batch->memcg = NULL;
2720}
2721
Daisuke Nishimurae767e052009-05-28 14:34:28 -07002722#ifdef CONFIG_SWAP
KAMEZAWA Hiroyuki8c7c6e32009-01-07 18:08:00 -08002723/*
Daisuke Nishimurae767e052009-05-28 14:34:28 -07002724 * called after __delete_from_swap_cache() and drop "page" account.
KAMEZAWA Hiroyuki8c7c6e32009-01-07 18:08:00 -08002725 * memcg information is recorded to swap_cgroup of "ent"
2726 */
KAMEZAWA Hiroyuki8a9478c2009-06-17 16:27:17 -07002727void
2728mem_cgroup_uncharge_swapcache(struct page *page, swp_entry_t ent, bool swapout)
KAMEZAWA Hiroyukid13d1442009-01-07 18:07:56 -08002729{
KAMEZAWA Hiroyuki8c7c6e32009-01-07 18:08:00 -08002730 struct mem_cgroup *memcg;
KAMEZAWA Hiroyuki8a9478c2009-06-17 16:27:17 -07002731 int ctype = MEM_CGROUP_CHARGE_TYPE_SWAPOUT;
KAMEZAWA Hiroyuki8c7c6e32009-01-07 18:08:00 -08002732
KAMEZAWA Hiroyuki8a9478c2009-06-17 16:27:17 -07002733 if (!swapout) /* this was a swap cache but the swap is unused ! */
2734 ctype = MEM_CGROUP_CHARGE_TYPE_DROP;
2735
2736 memcg = __mem_cgroup_uncharge_common(page, ctype);
2737
KAMEZAWA Hiroyukif75ca962010-08-10 18:03:02 -07002738 /*
2739 * record memcg information, if swapout && memcg != NULL,
2740 * mem_cgroup_get() was called in uncharge().
2741 */
2742 if (do_swap_account && swapout && memcg)
KAMEZAWA Hiroyukia3b2d692009-04-02 16:57:45 -07002743 swap_cgroup_record(ent, css_id(&memcg->css));
KAMEZAWA Hiroyukid13d1442009-01-07 18:07:56 -08002744}
Daisuke Nishimurae767e052009-05-28 14:34:28 -07002745#endif
KAMEZAWA Hiroyukid13d1442009-01-07 18:07:56 -08002746
KAMEZAWA Hiroyuki8c7c6e32009-01-07 18:08:00 -08002747#ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP
2748/*
2749 * called from swap_entry_free(). remove record in swap_cgroup and
2750 * uncharge "memsw" account.
2751 */
2752void mem_cgroup_uncharge_swap(swp_entry_t ent)
2753{
2754 struct mem_cgroup *memcg;
KAMEZAWA Hiroyukia3b2d692009-04-02 16:57:45 -07002755 unsigned short id;
KAMEZAWA Hiroyuki8c7c6e32009-01-07 18:08:00 -08002756
2757 if (!do_swap_account)
2758 return;
2759
KAMEZAWA Hiroyukia3b2d692009-04-02 16:57:45 -07002760 id = swap_cgroup_record(ent, 0);
2761 rcu_read_lock();
2762 memcg = mem_cgroup_lookup(id);
KAMEZAWA Hiroyuki8c7c6e32009-01-07 18:08:00 -08002763 if (memcg) {
KAMEZAWA Hiroyukia3b2d692009-04-02 16:57:45 -07002764 /*
2765 * We uncharge this because swap is freed.
2766 * This memcg can be obsolete one. We avoid calling css_tryget
2767 */
Balbir Singh0c3e73e2009-09-23 15:56:42 -07002768 if (!mem_cgroup_is_root(memcg))
KAMEZAWA Hiroyuki4e649152009-10-01 15:44:11 -07002769 res_counter_uncharge(&memcg->memsw, PAGE_SIZE);
Balbir Singh0c3e73e2009-09-23 15:56:42 -07002770 mem_cgroup_swap_statistics(memcg, false);
KAMEZAWA Hiroyuki8c7c6e32009-01-07 18:08:00 -08002771 mem_cgroup_put(memcg);
2772 }
KAMEZAWA Hiroyukia3b2d692009-04-02 16:57:45 -07002773 rcu_read_unlock();
KAMEZAWA Hiroyuki8c7c6e32009-01-07 18:08:00 -08002774}
Daisuke Nishimura02491442010-03-10 15:22:17 -08002775
2776/**
2777 * mem_cgroup_move_swap_account - move swap charge and swap_cgroup's record.
2778 * @entry: swap entry to be moved
2779 * @from: mem_cgroup which the entry is moved from
2780 * @to: mem_cgroup which the entry is moved to
Daisuke Nishimura483c30b2010-03-10 15:22:18 -08002781 * @need_fixup: whether we should fixup res_counters and refcounts.
Daisuke Nishimura02491442010-03-10 15:22:17 -08002782 *
2783 * It succeeds only when the swap_cgroup's record for this entry is the same
2784 * as the mem_cgroup's id of @from.
2785 *
2786 * Returns 0 on success, -EINVAL on failure.
2787 *
2788 * The caller must have charged to @to, IOW, called res_counter_charge() about
2789 * both res and memsw, and called css_get().
2790 */
2791static int mem_cgroup_move_swap_account(swp_entry_t entry,
Daisuke Nishimura483c30b2010-03-10 15:22:18 -08002792 struct mem_cgroup *from, struct mem_cgroup *to, bool need_fixup)
Daisuke Nishimura02491442010-03-10 15:22:17 -08002793{
2794 unsigned short old_id, new_id;
2795
2796 old_id = css_id(&from->css);
2797 new_id = css_id(&to->css);
2798
2799 if (swap_cgroup_cmpxchg(entry, old_id, new_id) == old_id) {
Daisuke Nishimura02491442010-03-10 15:22:17 -08002800 mem_cgroup_swap_statistics(from, false);
Daisuke Nishimura02491442010-03-10 15:22:17 -08002801 mem_cgroup_swap_statistics(to, true);
Daisuke Nishimura483c30b2010-03-10 15:22:18 -08002802 /*
2803 * This function is only called from task migration context now.
2804 * It postpones res_counter and refcount handling till the end
2805 * of task migration(mem_cgroup_clear_mc()) for performance
2806 * improvement. But we cannot postpone mem_cgroup_get(to)
2807 * because if the process that has been moved to @to does
2808 * swap-in, the refcount of @to might be decreased to 0.
2809 */
Daisuke Nishimura02491442010-03-10 15:22:17 -08002810 mem_cgroup_get(to);
Daisuke Nishimura483c30b2010-03-10 15:22:18 -08002811 if (need_fixup) {
2812 if (!mem_cgroup_is_root(from))
2813 res_counter_uncharge(&from->memsw, PAGE_SIZE);
2814 mem_cgroup_put(from);
2815 /*
2816 * we charged both to->res and to->memsw, so we should
2817 * uncharge to->res.
2818 */
2819 if (!mem_cgroup_is_root(to))
2820 res_counter_uncharge(&to->res, PAGE_SIZE);
Daisuke Nishimura483c30b2010-03-10 15:22:18 -08002821 }
Daisuke Nishimura02491442010-03-10 15:22:17 -08002822 return 0;
2823 }
2824 return -EINVAL;
2825}
2826#else
2827static inline int mem_cgroup_move_swap_account(swp_entry_t entry,
Daisuke Nishimura483c30b2010-03-10 15:22:18 -08002828 struct mem_cgroup *from, struct mem_cgroup *to, bool need_fixup)
Daisuke Nishimura02491442010-03-10 15:22:17 -08002829{
2830 return -EINVAL;
2831}
KAMEZAWA Hiroyuki8c7c6e32009-01-07 18:08:00 -08002832#endif
2833
KAMEZAWA Hiroyukiae41be32008-02-07 00:14:10 -08002834/*
KAMEZAWA Hiroyuki01b1ae62009-01-07 18:07:50 -08002835 * Before starting migration, account PAGE_SIZE to mem_cgroup that the old
2836 * page belongs to.
KAMEZAWA Hiroyukiae41be32008-02-07 00:14:10 -08002837 */
akpm@linux-foundation.orgac39cf82010-05-26 14:42:46 -07002838int mem_cgroup_prepare_migration(struct page *page,
2839 struct page *newpage, struct mem_cgroup **ptr)
KAMEZAWA Hiroyukiae41be32008-02-07 00:14:10 -08002840{
2841 struct page_cgroup *pc;
KAMEZAWA Hiroyukie8589cc2008-07-25 01:47:10 -07002842 struct mem_cgroup *mem = NULL;
akpm@linux-foundation.orgac39cf82010-05-26 14:42:46 -07002843 enum charge_type ctype;
KAMEZAWA Hiroyukie8589cc2008-07-25 01:47:10 -07002844 int ret = 0;
Hugh Dickins8869b8f2008-03-04 14:29:09 -08002845
Andrea Arcangeliec168512011-01-13 15:46:56 -08002846 VM_BUG_ON(PageTransHuge(page));
Hirokazu Takahashif8d66542009-01-07 18:08:02 -08002847 if (mem_cgroup_disabled())
Balbir Singh40779602008-04-04 14:29:59 -07002848 return 0;
2849
KAMEZAWA Hiroyuki52d4b9a2008-10-18 20:28:16 -07002850 pc = lookup_page_cgroup(page);
2851 lock_page_cgroup(pc);
2852 if (PageCgroupUsed(pc)) {
KAMEZAWA Hiroyukie8589cc2008-07-25 01:47:10 -07002853 mem = pc->mem_cgroup;
2854 css_get(&mem->css);
akpm@linux-foundation.orgac39cf82010-05-26 14:42:46 -07002855 /*
2856 * At migrating an anonymous page, its mapcount goes down
2857 * to 0 and uncharge() will be called. But, even if it's fully
2858 * unmapped, migration may fail and this page has to be
2859 * charged again. We set MIGRATION flag here and delay uncharge
2860 * until end_migration() is called
2861 *
2862 * Corner Case Thinking
2863 * A)
2864 * When the old page was mapped as Anon and it's unmap-and-freed
2865 * while migration was ongoing.
2866 * If unmap finds the old page, uncharge() of it will be delayed
2867 * until end_migration(). If unmap finds a new page, it's
2868 * uncharged when it make mapcount to be 1->0. If unmap code
2869 * finds swap_migration_entry, the new page will not be mapped
2870 * and end_migration() will find it(mapcount==0).
2871 *
2872 * B)
2873 * When the old page was mapped but migraion fails, the kernel
2874 * remaps it. A charge for it is kept by MIGRATION flag even
2875 * if mapcount goes down to 0. We can do remap successfully
2876 * without charging it again.
2877 *
2878 * C)
2879 * The "old" page is under lock_page() until the end of
2880 * migration, so, the old page itself will not be swapped-out.
2881 * If the new page is swapped out before end_migraton, our
2882 * hook to usual swap-out path will catch the event.
2883 */
2884 if (PageAnon(page))
2885 SetPageCgroupMigration(pc);
Hugh Dickinsb9c565d2008-03-04 14:29:11 -08002886 }
KAMEZAWA Hiroyuki52d4b9a2008-10-18 20:28:16 -07002887 unlock_page_cgroup(pc);
akpm@linux-foundation.orgac39cf82010-05-26 14:42:46 -07002888 /*
2889 * If the page is not charged at this point,
2890 * we return here.
2891 */
2892 if (!mem)
2893 return 0;
KAMEZAWA Hiroyuki01b1ae62009-01-07 18:07:50 -08002894
Andrea Arcangeli93d5c9b2010-04-23 13:17:39 -04002895 *ptr = mem;
Andrea Arcangeliec168512011-01-13 15:46:56 -08002896 ret = __mem_cgroup_try_charge(NULL, GFP_KERNEL, ptr, false, PAGE_SIZE);
akpm@linux-foundation.orgac39cf82010-05-26 14:42:46 -07002897 css_put(&mem->css);/* drop extra refcnt */
2898 if (ret || *ptr == NULL) {
2899 if (PageAnon(page)) {
2900 lock_page_cgroup(pc);
2901 ClearPageCgroupMigration(pc);
2902 unlock_page_cgroup(pc);
2903 /*
2904 * The old page may be fully unmapped while we kept it.
2905 */
2906 mem_cgroup_uncharge_page(page);
2907 }
2908 return -ENOMEM;
KAMEZAWA Hiroyukie8589cc2008-07-25 01:47:10 -07002909 }
akpm@linux-foundation.orgac39cf82010-05-26 14:42:46 -07002910 /*
2911 * We charge new page before it's used/mapped. So, even if unlock_page()
2912 * is called before end_migration, we can catch all events on this new
2913 * page. In the case new page is migrated but not remapped, new page's
2914 * mapcount will be finally 0 and we call uncharge in end_migration().
2915 */
2916 pc = lookup_page_cgroup(newpage);
2917 if (PageAnon(page))
2918 ctype = MEM_CGROUP_CHARGE_TYPE_MAPPED;
2919 else if (page_is_file_cache(page))
2920 ctype = MEM_CGROUP_CHARGE_TYPE_CACHE;
2921 else
2922 ctype = MEM_CGROUP_CHARGE_TYPE_SHMEM;
Andrea Arcangeliec168512011-01-13 15:46:56 -08002923 __mem_cgroup_commit_charge(mem, pc, ctype, PAGE_SIZE);
KAMEZAWA Hiroyukie8589cc2008-07-25 01:47:10 -07002924 return ret;
2925}
Hugh Dickinsfb59e9f2008-03-04 14:29:16 -08002926
KAMEZAWA Hiroyuki69029cd2008-07-25 01:47:14 -07002927/* remove redundant charge if migration failed*/
KAMEZAWA Hiroyuki01b1ae62009-01-07 18:07:50 -08002928void mem_cgroup_end_migration(struct mem_cgroup *mem,
Daisuke Nishimura50de1dd2011-01-13 15:47:43 -08002929 struct page *oldpage, struct page *newpage, bool migration_ok)
KAMEZAWA Hiroyukie8589cc2008-07-25 01:47:10 -07002930{
akpm@linux-foundation.orgac39cf82010-05-26 14:42:46 -07002931 struct page *used, *unused;
KAMEZAWA Hiroyuki01b1ae62009-01-07 18:07:50 -08002932 struct page_cgroup *pc;
KAMEZAWA Hiroyuki01b1ae62009-01-07 18:07:50 -08002933
2934 if (!mem)
2935 return;
akpm@linux-foundation.orgac39cf82010-05-26 14:42:46 -07002936 /* blocks rmdir() */
KAMEZAWA Hiroyuki88703262009-07-29 15:04:06 -07002937 cgroup_exclude_rmdir(&mem->css);
Daisuke Nishimura50de1dd2011-01-13 15:47:43 -08002938 if (!migration_ok) {
akpm@linux-foundation.orgac39cf82010-05-26 14:42:46 -07002939 used = oldpage;
2940 unused = newpage;
KAMEZAWA Hiroyuki01b1ae62009-01-07 18:07:50 -08002941 } else {
akpm@linux-foundation.orgac39cf82010-05-26 14:42:46 -07002942 used = newpage;
KAMEZAWA Hiroyuki01b1ae62009-01-07 18:07:50 -08002943 unused = oldpage;
2944 }
KAMEZAWA Hiroyuki69029cd2008-07-25 01:47:14 -07002945 /*
akpm@linux-foundation.orgac39cf82010-05-26 14:42:46 -07002946 * We disallowed uncharge of pages under migration because mapcount
2947 * of the page goes down to zero, temporarly.
2948 * Clear the flag and check the page should be charged.
KAMEZAWA Hiroyuki69029cd2008-07-25 01:47:14 -07002949 */
akpm@linux-foundation.orgac39cf82010-05-26 14:42:46 -07002950 pc = lookup_page_cgroup(oldpage);
2951 lock_page_cgroup(pc);
2952 ClearPageCgroupMigration(pc);
2953 unlock_page_cgroup(pc);
KAMEZAWA Hiroyuki01b1ae62009-01-07 18:07:50 -08002954
akpm@linux-foundation.orgac39cf82010-05-26 14:42:46 -07002955 __mem_cgroup_uncharge_common(unused, MEM_CGROUP_CHARGE_TYPE_FORCE);
2956
KAMEZAWA Hiroyuki01b1ae62009-01-07 18:07:50 -08002957 /*
akpm@linux-foundation.orgac39cf82010-05-26 14:42:46 -07002958 * If a page is a file cache, radix-tree replacement is very atomic
2959 * and we can skip this check. When it was an Anon page, its mapcount
2960 * goes down to 0. But because we added MIGRATION flage, it's not
2961 * uncharged yet. There are several case but page->mapcount check
2962 * and USED bit check in mem_cgroup_uncharge_page() will do enough
2963 * check. (see prepare_charge() also)
KAMEZAWA Hiroyuki01b1ae62009-01-07 18:07:50 -08002964 */
akpm@linux-foundation.orgac39cf82010-05-26 14:42:46 -07002965 if (PageAnon(used))
2966 mem_cgroup_uncharge_page(used);
KAMEZAWA Hiroyuki88703262009-07-29 15:04:06 -07002967 /*
akpm@linux-foundation.orgac39cf82010-05-26 14:42:46 -07002968 * At migration, we may charge account against cgroup which has no
2969 * tasks.
KAMEZAWA Hiroyuki88703262009-07-29 15:04:06 -07002970 * So, rmdir()->pre_destroy() can be called while we do this charge.
2971 * In that case, we need to call pre_destroy() again. check it here.
2972 */
2973 cgroup_release_and_wakeup_rmdir(&mem->css);
KAMEZAWA Hiroyukiae41be32008-02-07 00:14:10 -08002974}
Pavel Emelianov78fb7462008-02-07 00:13:51 -08002975
KAMEZAWA Hiroyukicc847582008-02-07 00:14:16 -08002976/*
Daisuke Nishimuraae3abae2009-04-30 15:08:19 -07002977 * A call to try to shrink memory usage on charge failure at shmem's swapin.
2978 * Calling hierarchical_reclaim is not enough because we should update
2979 * last_oom_jiffies to prevent pagefault_out_of_memory from invoking global OOM.
2980 * Moreover considering hierarchy, we should reclaim from the mem_over_limit,
2981 * not from the memcg which this page would be charged to.
2982 * try_charge_swapin does all of these works properly.
KAMEZAWA Hiroyukic9b0ed52008-07-25 01:47:15 -07002983 */
Daisuke Nishimuraae3abae2009-04-30 15:08:19 -07002984int mem_cgroup_shmem_charge_fallback(struct page *page,
KAMEZAWA Hiroyukib5a84312009-01-07 18:08:35 -08002985 struct mm_struct *mm,
2986 gfp_t gfp_mask)
KAMEZAWA Hiroyukic9b0ed52008-07-25 01:47:15 -07002987{
KAMEZAWA Hiroyukib5a84312009-01-07 18:08:35 -08002988 struct mem_cgroup *mem = NULL;
Daisuke Nishimuraae3abae2009-04-30 15:08:19 -07002989 int ret;
KAMEZAWA Hiroyukic9b0ed52008-07-25 01:47:15 -07002990
Hirokazu Takahashif8d66542009-01-07 18:08:02 -08002991 if (mem_cgroup_disabled())
Li Zefancede86a2008-07-25 01:47:18 -07002992 return 0;
KAMEZAWA Hiroyukic9b0ed52008-07-25 01:47:15 -07002993
Daisuke Nishimuraae3abae2009-04-30 15:08:19 -07002994 ret = mem_cgroup_try_charge_swapin(mm, page, gfp_mask, &mem);
2995 if (!ret)
2996 mem_cgroup_cancel_charge_swapin(mem); /* it does !mem check */
KAMEZAWA Hiroyukic9b0ed52008-07-25 01:47:15 -07002997
Daisuke Nishimuraae3abae2009-04-30 15:08:19 -07002998 return ret;
KAMEZAWA Hiroyukic9b0ed52008-07-25 01:47:15 -07002999}
3000
KAMEZAWA Hiroyuki8c7c6e32009-01-07 18:08:00 -08003001static DEFINE_MUTEX(set_limit_mutex);
3002
KOSAKI Motohirod38d2a72009-01-06 14:39:44 -08003003static int mem_cgroup_resize_limit(struct mem_cgroup *memcg,
KAMEZAWA Hiroyuki8c7c6e32009-01-07 18:08:00 -08003004 unsigned long long val)
KAMEZAWA Hiroyuki628f4232008-07-25 01:47:20 -07003005{
KAMEZAWA Hiroyuki81d39c22009-04-02 16:57:36 -07003006 int retry_count;
KAMEZAWA Hiroyuki3c11ecf2010-05-26 14:42:37 -07003007 u64 memswlimit, memlimit;
KAMEZAWA Hiroyuki628f4232008-07-25 01:47:20 -07003008 int ret = 0;
KAMEZAWA Hiroyuki81d39c22009-04-02 16:57:36 -07003009 int children = mem_cgroup_count_children(memcg);
3010 u64 curusage, oldusage;
KAMEZAWA Hiroyuki3c11ecf2010-05-26 14:42:37 -07003011 int enlarge;
KAMEZAWA Hiroyuki81d39c22009-04-02 16:57:36 -07003012
3013 /*
3014 * For keeping hierarchical_reclaim simple, how long we should retry
3015 * is depends on callers. We set our retry-count to be function
3016 * of # of children which we should visit in this loop.
3017 */
3018 retry_count = MEM_CGROUP_RECLAIM_RETRIES * children;
3019
3020 oldusage = res_counter_read_u64(&memcg->res, RES_USAGE);
KAMEZAWA Hiroyuki628f4232008-07-25 01:47:20 -07003021
KAMEZAWA Hiroyuki3c11ecf2010-05-26 14:42:37 -07003022 enlarge = 0;
KAMEZAWA Hiroyuki8c7c6e32009-01-07 18:08:00 -08003023 while (retry_count) {
KAMEZAWA Hiroyuki628f4232008-07-25 01:47:20 -07003024 if (signal_pending(current)) {
3025 ret = -EINTR;
3026 break;
3027 }
KAMEZAWA Hiroyuki8c7c6e32009-01-07 18:08:00 -08003028 /*
3029 * Rather than hide all in some function, I do this in
3030 * open coded manner. You see what this really does.
3031 * We have to guarantee mem->res.limit < mem->memsw.limit.
3032 */
3033 mutex_lock(&set_limit_mutex);
3034 memswlimit = res_counter_read_u64(&memcg->memsw, RES_LIMIT);
3035 if (memswlimit < val) {
3036 ret = -EINVAL;
3037 mutex_unlock(&set_limit_mutex);
KAMEZAWA Hiroyuki628f4232008-07-25 01:47:20 -07003038 break;
3039 }
KAMEZAWA Hiroyuki3c11ecf2010-05-26 14:42:37 -07003040
3041 memlimit = res_counter_read_u64(&memcg->res, RES_LIMIT);
3042 if (memlimit < val)
3043 enlarge = 1;
3044
KAMEZAWA Hiroyuki8c7c6e32009-01-07 18:08:00 -08003045 ret = res_counter_set_limit(&memcg->res, val);
KAMEZAWA Hiroyuki22a668d2009-06-17 16:27:19 -07003046 if (!ret) {
3047 if (memswlimit == val)
3048 memcg->memsw_is_minimum = true;
3049 else
3050 memcg->memsw_is_minimum = false;
3051 }
KAMEZAWA Hiroyuki8c7c6e32009-01-07 18:08:00 -08003052 mutex_unlock(&set_limit_mutex);
3053
3054 if (!ret)
3055 break;
3056
Bob Liuaa20d482009-12-15 16:47:14 -08003057 mem_cgroup_hierarchical_reclaim(memcg, NULL, GFP_KERNEL,
Balbir Singh4e416952009-09-23 15:56:39 -07003058 MEM_CGROUP_RECLAIM_SHRINK);
KAMEZAWA Hiroyuki81d39c22009-04-02 16:57:36 -07003059 curusage = res_counter_read_u64(&memcg->res, RES_USAGE);
3060 /* Usage is reduced ? */
3061 if (curusage >= oldusage)
3062 retry_count--;
3063 else
3064 oldusage = curusage;
KAMEZAWA Hiroyuki8c7c6e32009-01-07 18:08:00 -08003065 }
KAMEZAWA Hiroyuki3c11ecf2010-05-26 14:42:37 -07003066 if (!ret && enlarge)
3067 memcg_oom_recover(memcg);
KOSAKI Motohiro14797e22009-01-07 18:08:18 -08003068
KAMEZAWA Hiroyuki8c7c6e32009-01-07 18:08:00 -08003069 return ret;
3070}
3071
Li Zefan338c8432009-06-17 16:27:15 -07003072static int mem_cgroup_resize_memsw_limit(struct mem_cgroup *memcg,
3073 unsigned long long val)
KAMEZAWA Hiroyuki8c7c6e32009-01-07 18:08:00 -08003074{
KAMEZAWA Hiroyuki81d39c22009-04-02 16:57:36 -07003075 int retry_count;
KAMEZAWA Hiroyuki3c11ecf2010-05-26 14:42:37 -07003076 u64 memlimit, memswlimit, oldusage, curusage;
KAMEZAWA Hiroyuki81d39c22009-04-02 16:57:36 -07003077 int children = mem_cgroup_count_children(memcg);
3078 int ret = -EBUSY;
KAMEZAWA Hiroyuki3c11ecf2010-05-26 14:42:37 -07003079 int enlarge = 0;
KAMEZAWA Hiroyuki8c7c6e32009-01-07 18:08:00 -08003080
KAMEZAWA Hiroyuki81d39c22009-04-02 16:57:36 -07003081 /* see mem_cgroup_resize_res_limit */
3082 retry_count = children * MEM_CGROUP_RECLAIM_RETRIES;
3083 oldusage = res_counter_read_u64(&memcg->memsw, RES_USAGE);
KAMEZAWA Hiroyuki8c7c6e32009-01-07 18:08:00 -08003084 while (retry_count) {
3085 if (signal_pending(current)) {
3086 ret = -EINTR;
3087 break;
3088 }
3089 /*
3090 * Rather than hide all in some function, I do this in
3091 * open coded manner. You see what this really does.
3092 * We have to guarantee mem->res.limit < mem->memsw.limit.
3093 */
3094 mutex_lock(&set_limit_mutex);
3095 memlimit = res_counter_read_u64(&memcg->res, RES_LIMIT);
3096 if (memlimit > val) {
3097 ret = -EINVAL;
3098 mutex_unlock(&set_limit_mutex);
3099 break;
3100 }
KAMEZAWA Hiroyuki3c11ecf2010-05-26 14:42:37 -07003101 memswlimit = res_counter_read_u64(&memcg->memsw, RES_LIMIT);
3102 if (memswlimit < val)
3103 enlarge = 1;
KAMEZAWA Hiroyuki8c7c6e32009-01-07 18:08:00 -08003104 ret = res_counter_set_limit(&memcg->memsw, val);
KAMEZAWA Hiroyuki22a668d2009-06-17 16:27:19 -07003105 if (!ret) {
3106 if (memlimit == val)
3107 memcg->memsw_is_minimum = true;
3108 else
3109 memcg->memsw_is_minimum = false;
3110 }
KAMEZAWA Hiroyuki8c7c6e32009-01-07 18:08:00 -08003111 mutex_unlock(&set_limit_mutex);
3112
3113 if (!ret)
3114 break;
3115
Balbir Singh4e416952009-09-23 15:56:39 -07003116 mem_cgroup_hierarchical_reclaim(memcg, NULL, GFP_KERNEL,
Balbir Singh75822b42009-09-23 15:56:38 -07003117 MEM_CGROUP_RECLAIM_NOSWAP |
3118 MEM_CGROUP_RECLAIM_SHRINK);
KAMEZAWA Hiroyuki8c7c6e32009-01-07 18:08:00 -08003119 curusage = res_counter_read_u64(&memcg->memsw, RES_USAGE);
KAMEZAWA Hiroyuki81d39c22009-04-02 16:57:36 -07003120 /* Usage is reduced ? */
KAMEZAWA Hiroyuki8c7c6e32009-01-07 18:08:00 -08003121 if (curusage >= oldusage)
KAMEZAWA Hiroyuki628f4232008-07-25 01:47:20 -07003122 retry_count--;
KAMEZAWA Hiroyuki81d39c22009-04-02 16:57:36 -07003123 else
3124 oldusage = curusage;
KAMEZAWA Hiroyuki628f4232008-07-25 01:47:20 -07003125 }
KAMEZAWA Hiroyuki3c11ecf2010-05-26 14:42:37 -07003126 if (!ret && enlarge)
3127 memcg_oom_recover(memcg);
KAMEZAWA Hiroyuki628f4232008-07-25 01:47:20 -07003128 return ret;
3129}
3130
Balbir Singh4e416952009-09-23 15:56:39 -07003131unsigned long mem_cgroup_soft_limit_reclaim(struct zone *zone, int order,
KOSAKI Motohiro00918b62010-08-10 18:03:05 -07003132 gfp_t gfp_mask)
Balbir Singh4e416952009-09-23 15:56:39 -07003133{
3134 unsigned long nr_reclaimed = 0;
3135 struct mem_cgroup_per_zone *mz, *next_mz = NULL;
3136 unsigned long reclaimed;
3137 int loop = 0;
3138 struct mem_cgroup_tree_per_zone *mctz;
KAMEZAWA Hiroyukief8745c2009-10-01 15:44:12 -07003139 unsigned long long excess;
Balbir Singh4e416952009-09-23 15:56:39 -07003140
3141 if (order > 0)
3142 return 0;
3143
KOSAKI Motohiro00918b62010-08-10 18:03:05 -07003144 mctz = soft_limit_tree_node_zone(zone_to_nid(zone), zone_idx(zone));
Balbir Singh4e416952009-09-23 15:56:39 -07003145 /*
3146 * This loop can run a while, specially if mem_cgroup's continuously
3147 * keep exceeding their soft limit and putting the system under
3148 * pressure
3149 */
3150 do {
3151 if (next_mz)
3152 mz = next_mz;
3153 else
3154 mz = mem_cgroup_largest_soft_limit_node(mctz);
3155 if (!mz)
3156 break;
3157
3158 reclaimed = mem_cgroup_hierarchical_reclaim(mz->mem, zone,
3159 gfp_mask,
3160 MEM_CGROUP_RECLAIM_SOFT);
3161 nr_reclaimed += reclaimed;
3162 spin_lock(&mctz->lock);
3163
3164 /*
3165 * If we failed to reclaim anything from this memory cgroup
3166 * it is time to move on to the next cgroup
3167 */
3168 next_mz = NULL;
3169 if (!reclaimed) {
3170 do {
3171 /*
3172 * Loop until we find yet another one.
3173 *
3174 * By the time we get the soft_limit lock
3175 * again, someone might have aded the
3176 * group back on the RB tree. Iterate to
3177 * make sure we get a different mem.
3178 * mem_cgroup_largest_soft_limit_node returns
3179 * NULL if no other cgroup is present on
3180 * the tree
3181 */
3182 next_mz =
3183 __mem_cgroup_largest_soft_limit_node(mctz);
3184 if (next_mz == mz) {
3185 css_put(&next_mz->mem->css);
3186 next_mz = NULL;
3187 } else /* next_mz == NULL or other memcg */
3188 break;
3189 } while (1);
3190 }
Balbir Singh4e416952009-09-23 15:56:39 -07003191 __mem_cgroup_remove_exceeded(mz->mem, mz, mctz);
KAMEZAWA Hiroyukief8745c2009-10-01 15:44:12 -07003192 excess = res_counter_soft_limit_excess(&mz->mem->res);
Balbir Singh4e416952009-09-23 15:56:39 -07003193 /*
3194 * One school of thought says that we should not add
3195 * back the node to the tree if reclaim returns 0.
3196 * But our reclaim could return 0, simply because due
3197 * to priority we are exposing a smaller subset of
3198 * memory to reclaim from. Consider this as a longer
3199 * term TODO.
3200 */
KAMEZAWA Hiroyukief8745c2009-10-01 15:44:12 -07003201 /* If excess == 0, no tree ops */
3202 __mem_cgroup_insert_exceeded(mz->mem, mz, mctz, excess);
Balbir Singh4e416952009-09-23 15:56:39 -07003203 spin_unlock(&mctz->lock);
3204 css_put(&mz->mem->css);
3205 loop++;
3206 /*
3207 * Could not reclaim anything and there are no more
3208 * mem cgroups to try or we seem to be looping without
3209 * reclaiming anything.
3210 */
3211 if (!nr_reclaimed &&
3212 (next_mz == NULL ||
3213 loop > MEM_CGROUP_MAX_SOFT_LIMIT_RECLAIM_LOOPS))
3214 break;
3215 } while (!nr_reclaimed);
3216 if (next_mz)
3217 css_put(&next_mz->mem->css);
3218 return nr_reclaimed;
3219}
3220
KAMEZAWA Hiroyukic9b0ed52008-07-25 01:47:15 -07003221/*
KAMEZAWA Hiroyukicc847582008-02-07 00:14:16 -08003222 * This routine traverse page_cgroup in given list and drop them all.
KAMEZAWA Hiroyukicc847582008-02-07 00:14:16 -08003223 * *And* this routine doesn't reclaim page itself, just removes page_cgroup.
3224 */
KAMEZAWA Hiroyukif817ed42009-01-07 18:07:53 -08003225static int mem_cgroup_force_empty_list(struct mem_cgroup *mem,
KAMEZAWA Hiroyuki08e552c2009-01-07 18:08:01 -08003226 int node, int zid, enum lru_list lru)
KAMEZAWA Hiroyukicc847582008-02-07 00:14:16 -08003227{
KAMEZAWA Hiroyuki08e552c2009-01-07 18:08:01 -08003228 struct zone *zone;
3229 struct mem_cgroup_per_zone *mz;
KAMEZAWA Hiroyukif817ed42009-01-07 18:07:53 -08003230 struct page_cgroup *pc, *busy;
KAMEZAWA Hiroyuki08e552c2009-01-07 18:08:01 -08003231 unsigned long flags, loop;
KAMEZAWA Hiroyuki072c56c2008-02-07 00:14:39 -08003232 struct list_head *list;
KAMEZAWA Hiroyukif817ed42009-01-07 18:07:53 -08003233 int ret = 0;
KAMEZAWA Hiroyuki072c56c2008-02-07 00:14:39 -08003234
KAMEZAWA Hiroyuki08e552c2009-01-07 18:08:01 -08003235 zone = &NODE_DATA(node)->node_zones[zid];
3236 mz = mem_cgroup_zoneinfo(mem, node, zid);
Christoph Lameterb69408e2008-10-18 20:26:14 -07003237 list = &mz->lists[lru];
KAMEZAWA Hiroyukicc847582008-02-07 00:14:16 -08003238
KAMEZAWA Hiroyukif817ed42009-01-07 18:07:53 -08003239 loop = MEM_CGROUP_ZSTAT(mz, lru);
3240 /* give some margin against EBUSY etc...*/
3241 loop += 256;
3242 busy = NULL;
3243 while (loop--) {
3244 ret = 0;
KAMEZAWA Hiroyuki08e552c2009-01-07 18:08:01 -08003245 spin_lock_irqsave(&zone->lru_lock, flags);
KAMEZAWA Hiroyukif817ed42009-01-07 18:07:53 -08003246 if (list_empty(list)) {
KAMEZAWA Hiroyuki08e552c2009-01-07 18:08:01 -08003247 spin_unlock_irqrestore(&zone->lru_lock, flags);
KAMEZAWA Hiroyuki52d4b9a2008-10-18 20:28:16 -07003248 break;
3249 }
KAMEZAWA Hiroyukif817ed42009-01-07 18:07:53 -08003250 pc = list_entry(list->prev, struct page_cgroup, lru);
3251 if (busy == pc) {
3252 list_move(&pc->lru, list);
Thiago Farina648bcc72010-03-05 13:42:04 -08003253 busy = NULL;
KAMEZAWA Hiroyuki08e552c2009-01-07 18:08:01 -08003254 spin_unlock_irqrestore(&zone->lru_lock, flags);
KAMEZAWA Hiroyukif817ed42009-01-07 18:07:53 -08003255 continue;
3256 }
KAMEZAWA Hiroyuki08e552c2009-01-07 18:08:01 -08003257 spin_unlock_irqrestore(&zone->lru_lock, flags);
KAMEZAWA Hiroyukif817ed42009-01-07 18:07:53 -08003258
KAMEZAWA Hiroyuki2c26fdd2009-01-07 18:08:10 -08003259 ret = mem_cgroup_move_parent(pc, mem, GFP_KERNEL);
KAMEZAWA Hiroyukif817ed42009-01-07 18:07:53 -08003260 if (ret == -ENOMEM)
3261 break;
3262
3263 if (ret == -EBUSY || ret == -EINVAL) {
3264 /* found lock contention or "pc" is obsolete. */
3265 busy = pc;
3266 cond_resched();
3267 } else
3268 busy = NULL;
KAMEZAWA Hiroyukicc847582008-02-07 00:14:16 -08003269 }
KAMEZAWA Hiroyuki08e552c2009-01-07 18:08:01 -08003270
KAMEZAWA Hiroyukif817ed42009-01-07 18:07:53 -08003271 if (!ret && !list_empty(list))
3272 return -EBUSY;
3273 return ret;
KAMEZAWA Hiroyukicc847582008-02-07 00:14:16 -08003274}
3275
3276/*
3277 * make mem_cgroup's charge to be 0 if there is no task.
3278 * This enables deleting this mem_cgroup.
3279 */
KAMEZAWA Hiroyukic1e862c2009-01-07 18:07:55 -08003280static int mem_cgroup_force_empty(struct mem_cgroup *mem, bool free_all)
KAMEZAWA Hiroyukicc847582008-02-07 00:14:16 -08003281{
KAMEZAWA Hiroyukif817ed42009-01-07 18:07:53 -08003282 int ret;
3283 int node, zid, shrink;
3284 int nr_retries = MEM_CGROUP_RECLAIM_RETRIES;
KAMEZAWA Hiroyukic1e862c2009-01-07 18:07:55 -08003285 struct cgroup *cgrp = mem->css.cgroup;
Hugh Dickins8869b8f2008-03-04 14:29:09 -08003286
KAMEZAWA Hiroyukicc847582008-02-07 00:14:16 -08003287 css_get(&mem->css);
KAMEZAWA Hiroyukif817ed42009-01-07 18:07:53 -08003288
3289 shrink = 0;
KAMEZAWA Hiroyukic1e862c2009-01-07 18:07:55 -08003290 /* should free all ? */
3291 if (free_all)
3292 goto try_to_free;
KAMEZAWA Hiroyukif817ed42009-01-07 18:07:53 -08003293move_account:
Daisuke Nishimurafce66472010-01-15 17:01:30 -08003294 do {
KAMEZAWA Hiroyukif817ed42009-01-07 18:07:53 -08003295 ret = -EBUSY;
KAMEZAWA Hiroyukic1e862c2009-01-07 18:07:55 -08003296 if (cgroup_task_count(cgrp) || !list_empty(&cgrp->children))
KAMEZAWA Hiroyukicc847582008-02-07 00:14:16 -08003297 goto out;
KAMEZAWA Hiroyukic1e862c2009-01-07 18:07:55 -08003298 ret = -EINTR;
3299 if (signal_pending(current))
3300 goto out;
KAMEZAWA Hiroyuki52d4b9a2008-10-18 20:28:16 -07003301 /* This is for making all *used* pages to be on LRU. */
3302 lru_add_drain_all();
KAMEZAWA Hiroyukicdec2e42009-12-15 16:47:08 -08003303 drain_all_stock_sync();
KAMEZAWA Hiroyukif817ed42009-01-07 18:07:53 -08003304 ret = 0;
KAMEZAWA Hiroyuki32047e22010-10-27 15:33:40 -07003305 mem_cgroup_start_move(mem);
KAMEZAWA Hiroyuki299b4ea2009-01-29 14:25:17 -08003306 for_each_node_state(node, N_HIGH_MEMORY) {
KAMEZAWA Hiroyukif817ed42009-01-07 18:07:53 -08003307 for (zid = 0; !ret && zid < MAX_NR_ZONES; zid++) {
Christoph Lameterb69408e2008-10-18 20:26:14 -07003308 enum lru_list l;
KAMEZAWA Hiroyukif817ed42009-01-07 18:07:53 -08003309 for_each_lru(l) {
3310 ret = mem_cgroup_force_empty_list(mem,
KAMEZAWA Hiroyuki08e552c2009-01-07 18:08:01 -08003311 node, zid, l);
KAMEZAWA Hiroyukif817ed42009-01-07 18:07:53 -08003312 if (ret)
3313 break;
3314 }
KAMEZAWA Hiroyuki1ecaab22008-02-07 00:14:38 -08003315 }
KAMEZAWA Hiroyukif817ed42009-01-07 18:07:53 -08003316 if (ret)
3317 break;
3318 }
KAMEZAWA Hiroyuki32047e22010-10-27 15:33:40 -07003319 mem_cgroup_end_move(mem);
KAMEZAWA Hiroyuki3c11ecf2010-05-26 14:42:37 -07003320 memcg_oom_recover(mem);
KAMEZAWA Hiroyukif817ed42009-01-07 18:07:53 -08003321 /* it seems parent cgroup doesn't have enough mem */
3322 if (ret == -ENOMEM)
3323 goto try_to_free;
KAMEZAWA Hiroyuki52d4b9a2008-10-18 20:28:16 -07003324 cond_resched();
Daisuke Nishimurafce66472010-01-15 17:01:30 -08003325 /* "ret" should also be checked to ensure all lists are empty. */
3326 } while (mem->res.usage > 0 || ret);
KAMEZAWA Hiroyukicc847582008-02-07 00:14:16 -08003327out:
3328 css_put(&mem->css);
3329 return ret;
KAMEZAWA Hiroyukif817ed42009-01-07 18:07:53 -08003330
3331try_to_free:
KAMEZAWA Hiroyukic1e862c2009-01-07 18:07:55 -08003332 /* returns EBUSY if there is a task or if we come here twice. */
3333 if (cgroup_task_count(cgrp) || !list_empty(&cgrp->children) || shrink) {
KAMEZAWA Hiroyukif817ed42009-01-07 18:07:53 -08003334 ret = -EBUSY;
3335 goto out;
3336 }
KAMEZAWA Hiroyukic1e862c2009-01-07 18:07:55 -08003337 /* we call try-to-free pages for make this cgroup empty */
3338 lru_add_drain_all();
KAMEZAWA Hiroyukif817ed42009-01-07 18:07:53 -08003339 /* try to free all pages in this cgroup */
3340 shrink = 1;
3341 while (nr_retries && mem->res.usage > 0) {
3342 int progress;
KAMEZAWA Hiroyukic1e862c2009-01-07 18:07:55 -08003343
3344 if (signal_pending(current)) {
3345 ret = -EINTR;
3346 goto out;
3347 }
KOSAKI Motohiroa7885eb2009-01-07 18:08:24 -08003348 progress = try_to_free_mem_cgroup_pages(mem, GFP_KERNEL,
3349 false, get_swappiness(mem));
KAMEZAWA Hiroyukic1e862c2009-01-07 18:07:55 -08003350 if (!progress) {
KAMEZAWA Hiroyukif817ed42009-01-07 18:07:53 -08003351 nr_retries--;
KAMEZAWA Hiroyukic1e862c2009-01-07 18:07:55 -08003352 /* maybe some writeback is necessary */
Jens Axboe8aa7e842009-07-09 14:52:32 +02003353 congestion_wait(BLK_RW_ASYNC, HZ/10);
KAMEZAWA Hiroyukic1e862c2009-01-07 18:07:55 -08003354 }
KAMEZAWA Hiroyukif817ed42009-01-07 18:07:53 -08003355
3356 }
KAMEZAWA Hiroyuki08e552c2009-01-07 18:08:01 -08003357 lru_add_drain();
KAMEZAWA Hiroyukif817ed42009-01-07 18:07:53 -08003358 /* try move_account...there may be some *locked* pages. */
Daisuke Nishimurafce66472010-01-15 17:01:30 -08003359 goto move_account;
KAMEZAWA Hiroyukicc847582008-02-07 00:14:16 -08003360}
3361
KAMEZAWA Hiroyukic1e862c2009-01-07 18:07:55 -08003362int mem_cgroup_force_empty_write(struct cgroup *cont, unsigned int event)
3363{
3364 return mem_cgroup_force_empty(mem_cgroup_from_cont(cont), true);
3365}
3366
3367
Balbir Singh18f59ea2009-01-07 18:08:07 -08003368static u64 mem_cgroup_hierarchy_read(struct cgroup *cont, struct cftype *cft)
3369{
3370 return mem_cgroup_from_cont(cont)->use_hierarchy;
3371}
3372
3373static int mem_cgroup_hierarchy_write(struct cgroup *cont, struct cftype *cft,
3374 u64 val)
3375{
3376 int retval = 0;
3377 struct mem_cgroup *mem = mem_cgroup_from_cont(cont);
3378 struct cgroup *parent = cont->parent;
3379 struct mem_cgroup *parent_mem = NULL;
3380
3381 if (parent)
3382 parent_mem = mem_cgroup_from_cont(parent);
3383
3384 cgroup_lock();
3385 /*
André Goddard Rosaaf901ca2009-11-14 13:09:05 -02003386 * If parent's use_hierarchy is set, we can't make any modifications
Balbir Singh18f59ea2009-01-07 18:08:07 -08003387 * in the child subtrees. If it is unset, then the change can
3388 * occur, provided the current cgroup has no children.
3389 *
3390 * For the root cgroup, parent_mem is NULL, we allow value to be
3391 * set if there are no children.
3392 */
3393 if ((!parent_mem || !parent_mem->use_hierarchy) &&
3394 (val == 1 || val == 0)) {
3395 if (list_empty(&cont->children))
3396 mem->use_hierarchy = val;
3397 else
3398 retval = -EBUSY;
3399 } else
3400 retval = -EINVAL;
3401 cgroup_unlock();
3402
3403 return retval;
3404}
3405
Balbir Singh0c3e73e2009-09-23 15:56:42 -07003406
KAMEZAWA Hiroyuki7d74b062010-10-27 15:33:41 -07003407static u64 mem_cgroup_get_recursive_idx_stat(struct mem_cgroup *mem,
3408 enum mem_cgroup_stat_index idx)
Balbir Singh0c3e73e2009-09-23 15:56:42 -07003409{
KAMEZAWA Hiroyuki7d74b062010-10-27 15:33:41 -07003410 struct mem_cgroup *iter;
3411 s64 val = 0;
Balbir Singh0c3e73e2009-09-23 15:56:42 -07003412
KAMEZAWA Hiroyuki7d74b062010-10-27 15:33:41 -07003413 /* each per cpu's value can be minus.Then, use s64 */
3414 for_each_mem_cgroup_tree(iter, mem)
3415 val += mem_cgroup_read_stat(iter, idx);
3416
3417 if (val < 0) /* race ? */
3418 val = 0;
3419 return val;
Balbir Singh0c3e73e2009-09-23 15:56:42 -07003420}
3421
Kirill A. Shutemov104f3922010-03-10 15:22:21 -08003422static inline u64 mem_cgroup_usage(struct mem_cgroup *mem, bool swap)
3423{
KAMEZAWA Hiroyuki7d74b062010-10-27 15:33:41 -07003424 u64 val;
Kirill A. Shutemov104f3922010-03-10 15:22:21 -08003425
3426 if (!mem_cgroup_is_root(mem)) {
3427 if (!swap)
3428 return res_counter_read_u64(&mem->res, RES_USAGE);
3429 else
3430 return res_counter_read_u64(&mem->memsw, RES_USAGE);
3431 }
3432
KAMEZAWA Hiroyuki7d74b062010-10-27 15:33:41 -07003433 val = mem_cgroup_get_recursive_idx_stat(mem, MEM_CGROUP_STAT_CACHE);
3434 val += mem_cgroup_get_recursive_idx_stat(mem, MEM_CGROUP_STAT_RSS);
Kirill A. Shutemov104f3922010-03-10 15:22:21 -08003435
KAMEZAWA Hiroyuki7d74b062010-10-27 15:33:41 -07003436 if (swap)
3437 val += mem_cgroup_get_recursive_idx_stat(mem,
3438 MEM_CGROUP_STAT_SWAPOUT);
Kirill A. Shutemov104f3922010-03-10 15:22:21 -08003439
3440 return val << PAGE_SHIFT;
3441}
3442
Paul Menage2c3daa72008-04-29 00:59:58 -07003443static u64 mem_cgroup_read(struct cgroup *cont, struct cftype *cft)
Balbir Singh8cdea7c2008-02-07 00:13:50 -08003444{
KAMEZAWA Hiroyuki8c7c6e32009-01-07 18:08:00 -08003445 struct mem_cgroup *mem = mem_cgroup_from_cont(cont);
Kirill A. Shutemov104f3922010-03-10 15:22:21 -08003446 u64 val;
KAMEZAWA Hiroyuki8c7c6e32009-01-07 18:08:00 -08003447 int type, name;
3448
3449 type = MEMFILE_TYPE(cft->private);
3450 name = MEMFILE_ATTR(cft->private);
3451 switch (type) {
3452 case _MEM:
Kirill A. Shutemov104f3922010-03-10 15:22:21 -08003453 if (name == RES_USAGE)
3454 val = mem_cgroup_usage(mem, false);
3455 else
Balbir Singh0c3e73e2009-09-23 15:56:42 -07003456 val = res_counter_read_u64(&mem->res, name);
KAMEZAWA Hiroyuki8c7c6e32009-01-07 18:08:00 -08003457 break;
3458 case _MEMSWAP:
Kirill A. Shutemov104f3922010-03-10 15:22:21 -08003459 if (name == RES_USAGE)
3460 val = mem_cgroup_usage(mem, true);
3461 else
Balbir Singh0c3e73e2009-09-23 15:56:42 -07003462 val = res_counter_read_u64(&mem->memsw, name);
KAMEZAWA Hiroyuki8c7c6e32009-01-07 18:08:00 -08003463 break;
3464 default:
3465 BUG();
3466 break;
3467 }
3468 return val;
Balbir Singh8cdea7c2008-02-07 00:13:50 -08003469}
KAMEZAWA Hiroyuki628f4232008-07-25 01:47:20 -07003470/*
3471 * The user of this function is...
3472 * RES_LIMIT.
3473 */
Paul Menage856c13a2008-07-25 01:47:04 -07003474static int mem_cgroup_write(struct cgroup *cont, struct cftype *cft,
3475 const char *buffer)
Balbir Singh8cdea7c2008-02-07 00:13:50 -08003476{
KAMEZAWA Hiroyuki628f4232008-07-25 01:47:20 -07003477 struct mem_cgroup *memcg = mem_cgroup_from_cont(cont);
KAMEZAWA Hiroyuki8c7c6e32009-01-07 18:08:00 -08003478 int type, name;
KAMEZAWA Hiroyuki628f4232008-07-25 01:47:20 -07003479 unsigned long long val;
3480 int ret;
3481
KAMEZAWA Hiroyuki8c7c6e32009-01-07 18:08:00 -08003482 type = MEMFILE_TYPE(cft->private);
3483 name = MEMFILE_ATTR(cft->private);
3484 switch (name) {
KAMEZAWA Hiroyuki628f4232008-07-25 01:47:20 -07003485 case RES_LIMIT:
Balbir Singh4b3bde42009-09-23 15:56:32 -07003486 if (mem_cgroup_is_root(memcg)) { /* Can't set limit on root */
3487 ret = -EINVAL;
3488 break;
3489 }
KAMEZAWA Hiroyuki628f4232008-07-25 01:47:20 -07003490 /* This function does all necessary parse...reuse it */
3491 ret = res_counter_memparse_write_strategy(buffer, &val);
KAMEZAWA Hiroyuki8c7c6e32009-01-07 18:08:00 -08003492 if (ret)
3493 break;
3494 if (type == _MEM)
KAMEZAWA Hiroyuki628f4232008-07-25 01:47:20 -07003495 ret = mem_cgroup_resize_limit(memcg, val);
KAMEZAWA Hiroyuki8c7c6e32009-01-07 18:08:00 -08003496 else
3497 ret = mem_cgroup_resize_memsw_limit(memcg, val);
KAMEZAWA Hiroyuki628f4232008-07-25 01:47:20 -07003498 break;
Balbir Singh296c81d2009-09-23 15:56:36 -07003499 case RES_SOFT_LIMIT:
3500 ret = res_counter_memparse_write_strategy(buffer, &val);
3501 if (ret)
3502 break;
3503 /*
3504 * For memsw, soft limits are hard to implement in terms
3505 * of semantics, for now, we support soft limits for
3506 * control without swap
3507 */
3508 if (type == _MEM)
3509 ret = res_counter_set_soft_limit(&memcg->res, val);
3510 else
3511 ret = -EINVAL;
3512 break;
KAMEZAWA Hiroyuki628f4232008-07-25 01:47:20 -07003513 default:
3514 ret = -EINVAL; /* should be BUG() ? */
3515 break;
3516 }
3517 return ret;
Balbir Singh8cdea7c2008-02-07 00:13:50 -08003518}
3519
KAMEZAWA Hiroyukifee7b542009-01-07 18:08:26 -08003520static void memcg_get_hierarchical_limit(struct mem_cgroup *memcg,
3521 unsigned long long *mem_limit, unsigned long long *memsw_limit)
3522{
3523 struct cgroup *cgroup;
3524 unsigned long long min_limit, min_memsw_limit, tmp;
3525
3526 min_limit = res_counter_read_u64(&memcg->res, RES_LIMIT);
3527 min_memsw_limit = res_counter_read_u64(&memcg->memsw, RES_LIMIT);
3528 cgroup = memcg->css.cgroup;
3529 if (!memcg->use_hierarchy)
3530 goto out;
3531
3532 while (cgroup->parent) {
3533 cgroup = cgroup->parent;
3534 memcg = mem_cgroup_from_cont(cgroup);
3535 if (!memcg->use_hierarchy)
3536 break;
3537 tmp = res_counter_read_u64(&memcg->res, RES_LIMIT);
3538 min_limit = min(min_limit, tmp);
3539 tmp = res_counter_read_u64(&memcg->memsw, RES_LIMIT);
3540 min_memsw_limit = min(min_memsw_limit, tmp);
3541 }
3542out:
3543 *mem_limit = min_limit;
3544 *memsw_limit = min_memsw_limit;
3545 return;
3546}
3547
Pavel Emelyanov29f2a4d2008-04-29 01:00:21 -07003548static int mem_cgroup_reset(struct cgroup *cont, unsigned int event)
Pavel Emelyanovc84872e2008-04-29 01:00:17 -07003549{
3550 struct mem_cgroup *mem;
KAMEZAWA Hiroyuki8c7c6e32009-01-07 18:08:00 -08003551 int type, name;
Pavel Emelyanovc84872e2008-04-29 01:00:17 -07003552
3553 mem = mem_cgroup_from_cont(cont);
KAMEZAWA Hiroyuki8c7c6e32009-01-07 18:08:00 -08003554 type = MEMFILE_TYPE(event);
3555 name = MEMFILE_ATTR(event);
3556 switch (name) {
Pavel Emelyanov29f2a4d2008-04-29 01:00:21 -07003557 case RES_MAX_USAGE:
KAMEZAWA Hiroyuki8c7c6e32009-01-07 18:08:00 -08003558 if (type == _MEM)
3559 res_counter_reset_max(&mem->res);
3560 else
3561 res_counter_reset_max(&mem->memsw);
Pavel Emelyanov29f2a4d2008-04-29 01:00:21 -07003562 break;
3563 case RES_FAILCNT:
KAMEZAWA Hiroyuki8c7c6e32009-01-07 18:08:00 -08003564 if (type == _MEM)
3565 res_counter_reset_failcnt(&mem->res);
3566 else
3567 res_counter_reset_failcnt(&mem->memsw);
Pavel Emelyanov29f2a4d2008-04-29 01:00:21 -07003568 break;
3569 }
Balbir Singhf64c3f52009-09-23 15:56:37 -07003570
Pavel Emelyanov85cc59d2008-04-29 01:00:20 -07003571 return 0;
Pavel Emelyanovc84872e2008-04-29 01:00:17 -07003572}
3573
Daisuke Nishimura7dc74be2010-03-10 15:22:13 -08003574static u64 mem_cgroup_move_charge_read(struct cgroup *cgrp,
3575 struct cftype *cft)
3576{
3577 return mem_cgroup_from_cont(cgrp)->move_charge_at_immigrate;
3578}
3579
Daisuke Nishimura02491442010-03-10 15:22:17 -08003580#ifdef CONFIG_MMU
Daisuke Nishimura7dc74be2010-03-10 15:22:13 -08003581static int mem_cgroup_move_charge_write(struct cgroup *cgrp,
3582 struct cftype *cft, u64 val)
3583{
3584 struct mem_cgroup *mem = mem_cgroup_from_cont(cgrp);
3585
3586 if (val >= (1 << NR_MOVE_TYPE))
3587 return -EINVAL;
3588 /*
3589 * We check this value several times in both in can_attach() and
3590 * attach(), so we need cgroup lock to prevent this value from being
3591 * inconsistent.
3592 */
3593 cgroup_lock();
3594 mem->move_charge_at_immigrate = val;
3595 cgroup_unlock();
3596
3597 return 0;
3598}
Daisuke Nishimura02491442010-03-10 15:22:17 -08003599#else
3600static int mem_cgroup_move_charge_write(struct cgroup *cgrp,
3601 struct cftype *cft, u64 val)
3602{
3603 return -ENOSYS;
3604}
3605#endif
Daisuke Nishimura7dc74be2010-03-10 15:22:13 -08003606
KAMEZAWA Hiroyuki14067bb2009-04-02 16:57:35 -07003607
3608/* For read statistics */
3609enum {
3610 MCS_CACHE,
3611 MCS_RSS,
KAMEZAWA Hiroyukid8046582009-12-15 16:47:09 -08003612 MCS_FILE_MAPPED,
KAMEZAWA Hiroyuki14067bb2009-04-02 16:57:35 -07003613 MCS_PGPGIN,
3614 MCS_PGPGOUT,
Daisuke Nishimura1dd3a272009-09-23 15:56:43 -07003615 MCS_SWAP,
KAMEZAWA Hiroyuki14067bb2009-04-02 16:57:35 -07003616 MCS_INACTIVE_ANON,
3617 MCS_ACTIVE_ANON,
3618 MCS_INACTIVE_FILE,
3619 MCS_ACTIVE_FILE,
3620 MCS_UNEVICTABLE,
3621 NR_MCS_STAT,
KAMEZAWA Hiroyukid2ceb9b2008-02-07 00:14:25 -08003622};
3623
KAMEZAWA Hiroyuki14067bb2009-04-02 16:57:35 -07003624struct mcs_total_stat {
3625 s64 stat[NR_MCS_STAT];
3626};
3627
3628struct {
3629 char *local_name;
3630 char *total_name;
3631} memcg_stat_strings[NR_MCS_STAT] = {
3632 {"cache", "total_cache"},
3633 {"rss", "total_rss"},
Balbir Singhd69b0422009-06-17 16:26:34 -07003634 {"mapped_file", "total_mapped_file"},
KAMEZAWA Hiroyuki14067bb2009-04-02 16:57:35 -07003635 {"pgpgin", "total_pgpgin"},
3636 {"pgpgout", "total_pgpgout"},
Daisuke Nishimura1dd3a272009-09-23 15:56:43 -07003637 {"swap", "total_swap"},
KAMEZAWA Hiroyuki14067bb2009-04-02 16:57:35 -07003638 {"inactive_anon", "total_inactive_anon"},
3639 {"active_anon", "total_active_anon"},
3640 {"inactive_file", "total_inactive_file"},
3641 {"active_file", "total_active_file"},
3642 {"unevictable", "total_unevictable"}
3643};
3644
3645
KAMEZAWA Hiroyuki7d74b062010-10-27 15:33:41 -07003646static void
3647mem_cgroup_get_local_stat(struct mem_cgroup *mem, struct mcs_total_stat *s)
KAMEZAWA Hiroyuki14067bb2009-04-02 16:57:35 -07003648{
KAMEZAWA Hiroyuki14067bb2009-04-02 16:57:35 -07003649 s64 val;
3650
3651 /* per cpu stat */
KAMEZAWA Hiroyukic62b1a32010-03-10 15:22:29 -08003652 val = mem_cgroup_read_stat(mem, MEM_CGROUP_STAT_CACHE);
KAMEZAWA Hiroyuki14067bb2009-04-02 16:57:35 -07003653 s->stat[MCS_CACHE] += val * PAGE_SIZE;
KAMEZAWA Hiroyukic62b1a32010-03-10 15:22:29 -08003654 val = mem_cgroup_read_stat(mem, MEM_CGROUP_STAT_RSS);
KAMEZAWA Hiroyuki14067bb2009-04-02 16:57:35 -07003655 s->stat[MCS_RSS] += val * PAGE_SIZE;
KAMEZAWA Hiroyukic62b1a32010-03-10 15:22:29 -08003656 val = mem_cgroup_read_stat(mem, MEM_CGROUP_STAT_FILE_MAPPED);
KAMEZAWA Hiroyukid8046582009-12-15 16:47:09 -08003657 s->stat[MCS_FILE_MAPPED] += val * PAGE_SIZE;
KAMEZAWA Hiroyukic62b1a32010-03-10 15:22:29 -08003658 val = mem_cgroup_read_stat(mem, MEM_CGROUP_STAT_PGPGIN_COUNT);
KAMEZAWA Hiroyuki14067bb2009-04-02 16:57:35 -07003659 s->stat[MCS_PGPGIN] += val;
KAMEZAWA Hiroyukic62b1a32010-03-10 15:22:29 -08003660 val = mem_cgroup_read_stat(mem, MEM_CGROUP_STAT_PGPGOUT_COUNT);
KAMEZAWA Hiroyuki14067bb2009-04-02 16:57:35 -07003661 s->stat[MCS_PGPGOUT] += val;
Daisuke Nishimura1dd3a272009-09-23 15:56:43 -07003662 if (do_swap_account) {
KAMEZAWA Hiroyukic62b1a32010-03-10 15:22:29 -08003663 val = mem_cgroup_read_stat(mem, MEM_CGROUP_STAT_SWAPOUT);
Daisuke Nishimura1dd3a272009-09-23 15:56:43 -07003664 s->stat[MCS_SWAP] += val * PAGE_SIZE;
3665 }
KAMEZAWA Hiroyuki14067bb2009-04-02 16:57:35 -07003666
3667 /* per zone stat */
3668 val = mem_cgroup_get_local_zonestat(mem, LRU_INACTIVE_ANON);
3669 s->stat[MCS_INACTIVE_ANON] += val * PAGE_SIZE;
3670 val = mem_cgroup_get_local_zonestat(mem, LRU_ACTIVE_ANON);
3671 s->stat[MCS_ACTIVE_ANON] += val * PAGE_SIZE;
3672 val = mem_cgroup_get_local_zonestat(mem, LRU_INACTIVE_FILE);
3673 s->stat[MCS_INACTIVE_FILE] += val * PAGE_SIZE;
3674 val = mem_cgroup_get_local_zonestat(mem, LRU_ACTIVE_FILE);
3675 s->stat[MCS_ACTIVE_FILE] += val * PAGE_SIZE;
3676 val = mem_cgroup_get_local_zonestat(mem, LRU_UNEVICTABLE);
3677 s->stat[MCS_UNEVICTABLE] += val * PAGE_SIZE;
KAMEZAWA Hiroyuki14067bb2009-04-02 16:57:35 -07003678}
3679
3680static void
3681mem_cgroup_get_total_stat(struct mem_cgroup *mem, struct mcs_total_stat *s)
3682{
KAMEZAWA Hiroyuki7d74b062010-10-27 15:33:41 -07003683 struct mem_cgroup *iter;
3684
3685 for_each_mem_cgroup_tree(iter, mem)
3686 mem_cgroup_get_local_stat(iter, s);
KAMEZAWA Hiroyuki14067bb2009-04-02 16:57:35 -07003687}
3688
Paul Menagec64745c2008-04-29 01:00:02 -07003689static int mem_control_stat_show(struct cgroup *cont, struct cftype *cft,
3690 struct cgroup_map_cb *cb)
KAMEZAWA Hiroyukid2ceb9b2008-02-07 00:14:25 -08003691{
KAMEZAWA Hiroyukid2ceb9b2008-02-07 00:14:25 -08003692 struct mem_cgroup *mem_cont = mem_cgroup_from_cont(cont);
KAMEZAWA Hiroyuki14067bb2009-04-02 16:57:35 -07003693 struct mcs_total_stat mystat;
KAMEZAWA Hiroyukid2ceb9b2008-02-07 00:14:25 -08003694 int i;
3695
KAMEZAWA Hiroyuki14067bb2009-04-02 16:57:35 -07003696 memset(&mystat, 0, sizeof(mystat));
3697 mem_cgroup_get_local_stat(mem_cont, &mystat);
KAMEZAWA Hiroyukid2ceb9b2008-02-07 00:14:25 -08003698
Daisuke Nishimura1dd3a272009-09-23 15:56:43 -07003699 for (i = 0; i < NR_MCS_STAT; i++) {
3700 if (i == MCS_SWAP && !do_swap_account)
3701 continue;
KAMEZAWA Hiroyuki14067bb2009-04-02 16:57:35 -07003702 cb->fill(cb, memcg_stat_strings[i].local_name, mystat.stat[i]);
Daisuke Nishimura1dd3a272009-09-23 15:56:43 -07003703 }
KAMEZAWA Hiroyuki6d12e2d2008-02-07 00:14:31 -08003704
KAMEZAWA Hiroyuki14067bb2009-04-02 16:57:35 -07003705 /* Hierarchical information */
KAMEZAWA Hiroyukifee7b542009-01-07 18:08:26 -08003706 {
3707 unsigned long long limit, memsw_limit;
3708 memcg_get_hierarchical_limit(mem_cont, &limit, &memsw_limit);
3709 cb->fill(cb, "hierarchical_memory_limit", limit);
3710 if (do_swap_account)
3711 cb->fill(cb, "hierarchical_memsw_limit", memsw_limit);
3712 }
KOSAKI Motohiro7f016ee2009-01-07 18:08:22 -08003713
KAMEZAWA Hiroyuki14067bb2009-04-02 16:57:35 -07003714 memset(&mystat, 0, sizeof(mystat));
3715 mem_cgroup_get_total_stat(mem_cont, &mystat);
Daisuke Nishimura1dd3a272009-09-23 15:56:43 -07003716 for (i = 0; i < NR_MCS_STAT; i++) {
3717 if (i == MCS_SWAP && !do_swap_account)
3718 continue;
KAMEZAWA Hiroyuki14067bb2009-04-02 16:57:35 -07003719 cb->fill(cb, memcg_stat_strings[i].total_name, mystat.stat[i]);
Daisuke Nishimura1dd3a272009-09-23 15:56:43 -07003720 }
KAMEZAWA Hiroyuki14067bb2009-04-02 16:57:35 -07003721
KOSAKI Motohiro7f016ee2009-01-07 18:08:22 -08003722#ifdef CONFIG_DEBUG_VM
KOSAKI Motohiroc772be92009-01-07 18:08:25 -08003723 cb->fill(cb, "inactive_ratio", calc_inactive_ratio(mem_cont, NULL));
KOSAKI Motohiro7f016ee2009-01-07 18:08:22 -08003724
3725 {
3726 int nid, zid;
3727 struct mem_cgroup_per_zone *mz;
3728 unsigned long recent_rotated[2] = {0, 0};
3729 unsigned long recent_scanned[2] = {0, 0};
3730
3731 for_each_online_node(nid)
3732 for (zid = 0; zid < MAX_NR_ZONES; zid++) {
3733 mz = mem_cgroup_zoneinfo(mem_cont, nid, zid);
3734
3735 recent_rotated[0] +=
3736 mz->reclaim_stat.recent_rotated[0];
3737 recent_rotated[1] +=
3738 mz->reclaim_stat.recent_rotated[1];
3739 recent_scanned[0] +=
3740 mz->reclaim_stat.recent_scanned[0];
3741 recent_scanned[1] +=
3742 mz->reclaim_stat.recent_scanned[1];
3743 }
3744 cb->fill(cb, "recent_rotated_anon", recent_rotated[0]);
3745 cb->fill(cb, "recent_rotated_file", recent_rotated[1]);
3746 cb->fill(cb, "recent_scanned_anon", recent_scanned[0]);
3747 cb->fill(cb, "recent_scanned_file", recent_scanned[1]);
3748 }
3749#endif
3750
KAMEZAWA Hiroyukid2ceb9b2008-02-07 00:14:25 -08003751 return 0;
3752}
3753
KOSAKI Motohiroa7885eb2009-01-07 18:08:24 -08003754static u64 mem_cgroup_swappiness_read(struct cgroup *cgrp, struct cftype *cft)
3755{
3756 struct mem_cgroup *memcg = mem_cgroup_from_cont(cgrp);
3757
3758 return get_swappiness(memcg);
3759}
3760
3761static int mem_cgroup_swappiness_write(struct cgroup *cgrp, struct cftype *cft,
3762 u64 val)
3763{
3764 struct mem_cgroup *memcg = mem_cgroup_from_cont(cgrp);
3765 struct mem_cgroup *parent;
Li Zefan068b38c2009-01-15 13:51:26 -08003766
KOSAKI Motohiroa7885eb2009-01-07 18:08:24 -08003767 if (val > 100)
3768 return -EINVAL;
3769
3770 if (cgrp->parent == NULL)
3771 return -EINVAL;
3772
3773 parent = mem_cgroup_from_cont(cgrp->parent);
Li Zefan068b38c2009-01-15 13:51:26 -08003774
3775 cgroup_lock();
3776
KOSAKI Motohiroa7885eb2009-01-07 18:08:24 -08003777 /* If under hierarchy, only empty-root can set this value */
3778 if ((parent->use_hierarchy) ||
Li Zefan068b38c2009-01-15 13:51:26 -08003779 (memcg->use_hierarchy && !list_empty(&cgrp->children))) {
3780 cgroup_unlock();
KOSAKI Motohiroa7885eb2009-01-07 18:08:24 -08003781 return -EINVAL;
Li Zefan068b38c2009-01-15 13:51:26 -08003782 }
KOSAKI Motohiroa7885eb2009-01-07 18:08:24 -08003783
3784 spin_lock(&memcg->reclaim_param_lock);
3785 memcg->swappiness = val;
3786 spin_unlock(&memcg->reclaim_param_lock);
3787
Li Zefan068b38c2009-01-15 13:51:26 -08003788 cgroup_unlock();
3789
KOSAKI Motohiroa7885eb2009-01-07 18:08:24 -08003790 return 0;
3791}
3792
Kirill A. Shutemov2e72b632010-03-10 15:22:24 -08003793static void __mem_cgroup_threshold(struct mem_cgroup *memcg, bool swap)
3794{
3795 struct mem_cgroup_threshold_ary *t;
3796 u64 usage;
3797 int i;
3798
3799 rcu_read_lock();
3800 if (!swap)
Kirill A. Shutemov2c488db2010-05-26 14:42:47 -07003801 t = rcu_dereference(memcg->thresholds.primary);
Kirill A. Shutemov2e72b632010-03-10 15:22:24 -08003802 else
Kirill A. Shutemov2c488db2010-05-26 14:42:47 -07003803 t = rcu_dereference(memcg->memsw_thresholds.primary);
Kirill A. Shutemov2e72b632010-03-10 15:22:24 -08003804
3805 if (!t)
3806 goto unlock;
3807
3808 usage = mem_cgroup_usage(memcg, swap);
3809
3810 /*
3811 * current_threshold points to threshold just below usage.
3812 * If it's not true, a threshold was crossed after last
3813 * call of __mem_cgroup_threshold().
3814 */
Phil Carmody5407a562010-05-26 14:42:42 -07003815 i = t->current_threshold;
Kirill A. Shutemov2e72b632010-03-10 15:22:24 -08003816
3817 /*
3818 * Iterate backward over array of thresholds starting from
3819 * current_threshold and check if a threshold is crossed.
3820 * If none of thresholds below usage is crossed, we read
3821 * only one element of the array here.
3822 */
3823 for (; i >= 0 && unlikely(t->entries[i].threshold > usage); i--)
3824 eventfd_signal(t->entries[i].eventfd, 1);
3825
3826 /* i = current_threshold + 1 */
3827 i++;
3828
3829 /*
3830 * Iterate forward over array of thresholds starting from
3831 * current_threshold+1 and check if a threshold is crossed.
3832 * If none of thresholds above usage is crossed, we read
3833 * only one element of the array here.
3834 */
3835 for (; i < t->size && unlikely(t->entries[i].threshold <= usage); i++)
3836 eventfd_signal(t->entries[i].eventfd, 1);
3837
3838 /* Update current_threshold */
Phil Carmody5407a562010-05-26 14:42:42 -07003839 t->current_threshold = i - 1;
Kirill A. Shutemov2e72b632010-03-10 15:22:24 -08003840unlock:
3841 rcu_read_unlock();
3842}
3843
3844static void mem_cgroup_threshold(struct mem_cgroup *memcg)
3845{
Kirill A. Shutemovad4ca5f2010-10-07 12:59:27 -07003846 while (memcg) {
3847 __mem_cgroup_threshold(memcg, false);
3848 if (do_swap_account)
3849 __mem_cgroup_threshold(memcg, true);
3850
3851 memcg = parent_mem_cgroup(memcg);
3852 }
Kirill A. Shutemov2e72b632010-03-10 15:22:24 -08003853}
3854
3855static int compare_thresholds(const void *a, const void *b)
3856{
3857 const struct mem_cgroup_threshold *_a = a;
3858 const struct mem_cgroup_threshold *_b = b;
3859
3860 return _a->threshold - _b->threshold;
3861}
3862
KAMEZAWA Hiroyuki7d74b062010-10-27 15:33:41 -07003863static int mem_cgroup_oom_notify_cb(struct mem_cgroup *mem)
KAMEZAWA Hiroyuki9490ff22010-05-26 14:42:36 -07003864{
3865 struct mem_cgroup_eventfd_list *ev;
3866
3867 list_for_each_entry(ev, &mem->oom_notify, list)
3868 eventfd_signal(ev->eventfd, 1);
3869 return 0;
3870}
3871
3872static void mem_cgroup_oom_notify(struct mem_cgroup *mem)
3873{
KAMEZAWA Hiroyuki7d74b062010-10-27 15:33:41 -07003874 struct mem_cgroup *iter;
3875
3876 for_each_mem_cgroup_tree(iter, mem)
3877 mem_cgroup_oom_notify_cb(iter);
KAMEZAWA Hiroyuki9490ff22010-05-26 14:42:36 -07003878}
3879
3880static int mem_cgroup_usage_register_event(struct cgroup *cgrp,
3881 struct cftype *cft, struct eventfd_ctx *eventfd, const char *args)
Kirill A. Shutemov2e72b632010-03-10 15:22:24 -08003882{
3883 struct mem_cgroup *memcg = mem_cgroup_from_cont(cgrp);
Kirill A. Shutemov2c488db2010-05-26 14:42:47 -07003884 struct mem_cgroup_thresholds *thresholds;
3885 struct mem_cgroup_threshold_ary *new;
Kirill A. Shutemov2e72b632010-03-10 15:22:24 -08003886 int type = MEMFILE_TYPE(cft->private);
3887 u64 threshold, usage;
Kirill A. Shutemov2c488db2010-05-26 14:42:47 -07003888 int i, size, ret;
Kirill A. Shutemov2e72b632010-03-10 15:22:24 -08003889
3890 ret = res_counter_memparse_write_strategy(args, &threshold);
3891 if (ret)
3892 return ret;
3893
3894 mutex_lock(&memcg->thresholds_lock);
Kirill A. Shutemov2c488db2010-05-26 14:42:47 -07003895
Kirill A. Shutemov2e72b632010-03-10 15:22:24 -08003896 if (type == _MEM)
Kirill A. Shutemov2c488db2010-05-26 14:42:47 -07003897 thresholds = &memcg->thresholds;
Kirill A. Shutemov2e72b632010-03-10 15:22:24 -08003898 else if (type == _MEMSWAP)
Kirill A. Shutemov2c488db2010-05-26 14:42:47 -07003899 thresholds = &memcg->memsw_thresholds;
Kirill A. Shutemov2e72b632010-03-10 15:22:24 -08003900 else
3901 BUG();
3902
3903 usage = mem_cgroup_usage(memcg, type == _MEMSWAP);
3904
3905 /* Check if a threshold crossed before adding a new one */
Kirill A. Shutemov2c488db2010-05-26 14:42:47 -07003906 if (thresholds->primary)
Kirill A. Shutemov2e72b632010-03-10 15:22:24 -08003907 __mem_cgroup_threshold(memcg, type == _MEMSWAP);
3908
Kirill A. Shutemov2c488db2010-05-26 14:42:47 -07003909 size = thresholds->primary ? thresholds->primary->size + 1 : 1;
Kirill A. Shutemov2e72b632010-03-10 15:22:24 -08003910
3911 /* Allocate memory for new array of thresholds */
Kirill A. Shutemov2c488db2010-05-26 14:42:47 -07003912 new = kmalloc(sizeof(*new) + size * sizeof(struct mem_cgroup_threshold),
Kirill A. Shutemov2e72b632010-03-10 15:22:24 -08003913 GFP_KERNEL);
Kirill A. Shutemov2c488db2010-05-26 14:42:47 -07003914 if (!new) {
Kirill A. Shutemov2e72b632010-03-10 15:22:24 -08003915 ret = -ENOMEM;
3916 goto unlock;
3917 }
Kirill A. Shutemov2c488db2010-05-26 14:42:47 -07003918 new->size = size;
Kirill A. Shutemov2e72b632010-03-10 15:22:24 -08003919
3920 /* Copy thresholds (if any) to new array */
Kirill A. Shutemov2c488db2010-05-26 14:42:47 -07003921 if (thresholds->primary) {
3922 memcpy(new->entries, thresholds->primary->entries, (size - 1) *
Kirill A. Shutemov2e72b632010-03-10 15:22:24 -08003923 sizeof(struct mem_cgroup_threshold));
Kirill A. Shutemov2c488db2010-05-26 14:42:47 -07003924 }
3925
Kirill A. Shutemov2e72b632010-03-10 15:22:24 -08003926 /* Add new threshold */
Kirill A. Shutemov2c488db2010-05-26 14:42:47 -07003927 new->entries[size - 1].eventfd = eventfd;
3928 new->entries[size - 1].threshold = threshold;
Kirill A. Shutemov2e72b632010-03-10 15:22:24 -08003929
3930 /* Sort thresholds. Registering of new threshold isn't time-critical */
Kirill A. Shutemov2c488db2010-05-26 14:42:47 -07003931 sort(new->entries, size, sizeof(struct mem_cgroup_threshold),
Kirill A. Shutemov2e72b632010-03-10 15:22:24 -08003932 compare_thresholds, NULL);
3933
3934 /* Find current threshold */
Kirill A. Shutemov2c488db2010-05-26 14:42:47 -07003935 new->current_threshold = -1;
Kirill A. Shutemov2e72b632010-03-10 15:22:24 -08003936 for (i = 0; i < size; i++) {
Kirill A. Shutemov2c488db2010-05-26 14:42:47 -07003937 if (new->entries[i].threshold < usage) {
Kirill A. Shutemov2e72b632010-03-10 15:22:24 -08003938 /*
Kirill A. Shutemov2c488db2010-05-26 14:42:47 -07003939 * new->current_threshold will not be used until
3940 * rcu_assign_pointer(), so it's safe to increment
Kirill A. Shutemov2e72b632010-03-10 15:22:24 -08003941 * it here.
3942 */
Kirill A. Shutemov2c488db2010-05-26 14:42:47 -07003943 ++new->current_threshold;
Kirill A. Shutemov2e72b632010-03-10 15:22:24 -08003944 }
3945 }
3946
Kirill A. Shutemov2c488db2010-05-26 14:42:47 -07003947 /* Free old spare buffer and save old primary buffer as spare */
3948 kfree(thresholds->spare);
3949 thresholds->spare = thresholds->primary;
3950
3951 rcu_assign_pointer(thresholds->primary, new);
Kirill A. Shutemov2e72b632010-03-10 15:22:24 -08003952
Kirill A. Shutemov907860e2010-05-26 14:42:46 -07003953 /* To be sure that nobody uses thresholds */
Kirill A. Shutemov2e72b632010-03-10 15:22:24 -08003954 synchronize_rcu();
3955
Kirill A. Shutemov2e72b632010-03-10 15:22:24 -08003956unlock:
3957 mutex_unlock(&memcg->thresholds_lock);
3958
3959 return ret;
3960}
3961
Kirill A. Shutemov907860e2010-05-26 14:42:46 -07003962static void mem_cgroup_usage_unregister_event(struct cgroup *cgrp,
KAMEZAWA Hiroyuki9490ff22010-05-26 14:42:36 -07003963 struct cftype *cft, struct eventfd_ctx *eventfd)
Kirill A. Shutemov2e72b632010-03-10 15:22:24 -08003964{
3965 struct mem_cgroup *memcg = mem_cgroup_from_cont(cgrp);
Kirill A. Shutemov2c488db2010-05-26 14:42:47 -07003966 struct mem_cgroup_thresholds *thresholds;
3967 struct mem_cgroup_threshold_ary *new;
Kirill A. Shutemov2e72b632010-03-10 15:22:24 -08003968 int type = MEMFILE_TYPE(cft->private);
3969 u64 usage;
Kirill A. Shutemov2c488db2010-05-26 14:42:47 -07003970 int i, j, size;
Kirill A. Shutemov2e72b632010-03-10 15:22:24 -08003971
3972 mutex_lock(&memcg->thresholds_lock);
3973 if (type == _MEM)
Kirill A. Shutemov2c488db2010-05-26 14:42:47 -07003974 thresholds = &memcg->thresholds;
Kirill A. Shutemov2e72b632010-03-10 15:22:24 -08003975 else if (type == _MEMSWAP)
Kirill A. Shutemov2c488db2010-05-26 14:42:47 -07003976 thresholds = &memcg->memsw_thresholds;
Kirill A. Shutemov2e72b632010-03-10 15:22:24 -08003977 else
3978 BUG();
3979
3980 /*
3981 * Something went wrong if we trying to unregister a threshold
3982 * if we don't have thresholds
3983 */
3984 BUG_ON(!thresholds);
3985
3986 usage = mem_cgroup_usage(memcg, type == _MEMSWAP);
3987
3988 /* Check if a threshold crossed before removing */
3989 __mem_cgroup_threshold(memcg, type == _MEMSWAP);
3990
3991 /* Calculate new number of threshold */
Kirill A. Shutemov2c488db2010-05-26 14:42:47 -07003992 size = 0;
3993 for (i = 0; i < thresholds->primary->size; i++) {
3994 if (thresholds->primary->entries[i].eventfd != eventfd)
Kirill A. Shutemov2e72b632010-03-10 15:22:24 -08003995 size++;
3996 }
3997
Kirill A. Shutemov2c488db2010-05-26 14:42:47 -07003998 new = thresholds->spare;
Kirill A. Shutemov907860e2010-05-26 14:42:46 -07003999
Kirill A. Shutemov2e72b632010-03-10 15:22:24 -08004000 /* Set thresholds array to NULL if we don't have thresholds */
4001 if (!size) {
Kirill A. Shutemov2c488db2010-05-26 14:42:47 -07004002 kfree(new);
4003 new = NULL;
Kirill A. Shutemov907860e2010-05-26 14:42:46 -07004004 goto swap_buffers;
Kirill A. Shutemov2e72b632010-03-10 15:22:24 -08004005 }
4006
Kirill A. Shutemov2c488db2010-05-26 14:42:47 -07004007 new->size = size;
Kirill A. Shutemov2e72b632010-03-10 15:22:24 -08004008
4009 /* Copy thresholds and find current threshold */
Kirill A. Shutemov2c488db2010-05-26 14:42:47 -07004010 new->current_threshold = -1;
4011 for (i = 0, j = 0; i < thresholds->primary->size; i++) {
4012 if (thresholds->primary->entries[i].eventfd == eventfd)
Kirill A. Shutemov2e72b632010-03-10 15:22:24 -08004013 continue;
4014
Kirill A. Shutemov2c488db2010-05-26 14:42:47 -07004015 new->entries[j] = thresholds->primary->entries[i];
4016 if (new->entries[j].threshold < usage) {
Kirill A. Shutemov2e72b632010-03-10 15:22:24 -08004017 /*
Kirill A. Shutemov2c488db2010-05-26 14:42:47 -07004018 * new->current_threshold will not be used
Kirill A. Shutemov2e72b632010-03-10 15:22:24 -08004019 * until rcu_assign_pointer(), so it's safe to increment
4020 * it here.
4021 */
Kirill A. Shutemov2c488db2010-05-26 14:42:47 -07004022 ++new->current_threshold;
Kirill A. Shutemov2e72b632010-03-10 15:22:24 -08004023 }
4024 j++;
4025 }
4026
Kirill A. Shutemov907860e2010-05-26 14:42:46 -07004027swap_buffers:
Kirill A. Shutemov2c488db2010-05-26 14:42:47 -07004028 /* Swap primary and spare array */
4029 thresholds->spare = thresholds->primary;
4030 rcu_assign_pointer(thresholds->primary, new);
Kirill A. Shutemov2e72b632010-03-10 15:22:24 -08004031
Kirill A. Shutemov907860e2010-05-26 14:42:46 -07004032 /* To be sure that nobody uses thresholds */
Kirill A. Shutemov2e72b632010-03-10 15:22:24 -08004033 synchronize_rcu();
4034
Kirill A. Shutemov2e72b632010-03-10 15:22:24 -08004035 mutex_unlock(&memcg->thresholds_lock);
Kirill A. Shutemov2e72b632010-03-10 15:22:24 -08004036}
KAMEZAWA Hiroyukic1e862c2009-01-07 18:07:55 -08004037
KAMEZAWA Hiroyuki9490ff22010-05-26 14:42:36 -07004038static int mem_cgroup_oom_register_event(struct cgroup *cgrp,
4039 struct cftype *cft, struct eventfd_ctx *eventfd, const char *args)
4040{
4041 struct mem_cgroup *memcg = mem_cgroup_from_cont(cgrp);
4042 struct mem_cgroup_eventfd_list *event;
4043 int type = MEMFILE_TYPE(cft->private);
4044
4045 BUG_ON(type != _OOM_TYPE);
4046 event = kmalloc(sizeof(*event), GFP_KERNEL);
4047 if (!event)
4048 return -ENOMEM;
4049
4050 mutex_lock(&memcg_oom_mutex);
4051
4052 event->eventfd = eventfd;
4053 list_add(&event->list, &memcg->oom_notify);
4054
4055 /* already in OOM ? */
4056 if (atomic_read(&memcg->oom_lock))
4057 eventfd_signal(eventfd, 1);
4058 mutex_unlock(&memcg_oom_mutex);
4059
4060 return 0;
4061}
4062
Kirill A. Shutemov907860e2010-05-26 14:42:46 -07004063static void mem_cgroup_oom_unregister_event(struct cgroup *cgrp,
KAMEZAWA Hiroyuki9490ff22010-05-26 14:42:36 -07004064 struct cftype *cft, struct eventfd_ctx *eventfd)
4065{
4066 struct mem_cgroup *mem = mem_cgroup_from_cont(cgrp);
4067 struct mem_cgroup_eventfd_list *ev, *tmp;
4068 int type = MEMFILE_TYPE(cft->private);
4069
4070 BUG_ON(type != _OOM_TYPE);
4071
4072 mutex_lock(&memcg_oom_mutex);
4073
4074 list_for_each_entry_safe(ev, tmp, &mem->oom_notify, list) {
4075 if (ev->eventfd == eventfd) {
4076 list_del(&ev->list);
4077 kfree(ev);
4078 }
4079 }
4080
4081 mutex_unlock(&memcg_oom_mutex);
KAMEZAWA Hiroyuki9490ff22010-05-26 14:42:36 -07004082}
4083
KAMEZAWA Hiroyuki3c11ecf2010-05-26 14:42:37 -07004084static int mem_cgroup_oom_control_read(struct cgroup *cgrp,
4085 struct cftype *cft, struct cgroup_map_cb *cb)
4086{
4087 struct mem_cgroup *mem = mem_cgroup_from_cont(cgrp);
4088
4089 cb->fill(cb, "oom_kill_disable", mem->oom_kill_disable);
4090
4091 if (atomic_read(&mem->oom_lock))
4092 cb->fill(cb, "under_oom", 1);
4093 else
4094 cb->fill(cb, "under_oom", 0);
4095 return 0;
4096}
4097
KAMEZAWA Hiroyuki3c11ecf2010-05-26 14:42:37 -07004098static int mem_cgroup_oom_control_write(struct cgroup *cgrp,
4099 struct cftype *cft, u64 val)
4100{
4101 struct mem_cgroup *mem = mem_cgroup_from_cont(cgrp);
4102 struct mem_cgroup *parent;
4103
4104 /* cannot set to root cgroup and only 0 and 1 are allowed */
4105 if (!cgrp->parent || !((val == 0) || (val == 1)))
4106 return -EINVAL;
4107
4108 parent = mem_cgroup_from_cont(cgrp->parent);
4109
4110 cgroup_lock();
4111 /* oom-kill-disable is a flag for subhierarchy. */
4112 if ((parent->use_hierarchy) ||
4113 (mem->use_hierarchy && !list_empty(&cgrp->children))) {
4114 cgroup_unlock();
4115 return -EINVAL;
4116 }
4117 mem->oom_kill_disable = val;
KAMEZAWA Hiroyuki4d845eb2010-06-29 15:05:18 -07004118 if (!val)
4119 memcg_oom_recover(mem);
KAMEZAWA Hiroyuki3c11ecf2010-05-26 14:42:37 -07004120 cgroup_unlock();
4121 return 0;
4122}
4123
Balbir Singh8cdea7c2008-02-07 00:13:50 -08004124static struct cftype mem_cgroup_files[] = {
4125 {
Balbir Singh0eea1032008-02-07 00:13:57 -08004126 .name = "usage_in_bytes",
KAMEZAWA Hiroyuki8c7c6e32009-01-07 18:08:00 -08004127 .private = MEMFILE_PRIVATE(_MEM, RES_USAGE),
Paul Menage2c3daa72008-04-29 00:59:58 -07004128 .read_u64 = mem_cgroup_read,
KAMEZAWA Hiroyuki9490ff22010-05-26 14:42:36 -07004129 .register_event = mem_cgroup_usage_register_event,
4130 .unregister_event = mem_cgroup_usage_unregister_event,
Balbir Singh8cdea7c2008-02-07 00:13:50 -08004131 },
4132 {
Pavel Emelyanovc84872e2008-04-29 01:00:17 -07004133 .name = "max_usage_in_bytes",
KAMEZAWA Hiroyuki8c7c6e32009-01-07 18:08:00 -08004134 .private = MEMFILE_PRIVATE(_MEM, RES_MAX_USAGE),
Pavel Emelyanov29f2a4d2008-04-29 01:00:21 -07004135 .trigger = mem_cgroup_reset,
Pavel Emelyanovc84872e2008-04-29 01:00:17 -07004136 .read_u64 = mem_cgroup_read,
4137 },
4138 {
Balbir Singh0eea1032008-02-07 00:13:57 -08004139 .name = "limit_in_bytes",
KAMEZAWA Hiroyuki8c7c6e32009-01-07 18:08:00 -08004140 .private = MEMFILE_PRIVATE(_MEM, RES_LIMIT),
Paul Menage856c13a2008-07-25 01:47:04 -07004141 .write_string = mem_cgroup_write,
Paul Menage2c3daa72008-04-29 00:59:58 -07004142 .read_u64 = mem_cgroup_read,
Balbir Singh8cdea7c2008-02-07 00:13:50 -08004143 },
4144 {
Balbir Singh296c81d2009-09-23 15:56:36 -07004145 .name = "soft_limit_in_bytes",
4146 .private = MEMFILE_PRIVATE(_MEM, RES_SOFT_LIMIT),
4147 .write_string = mem_cgroup_write,
4148 .read_u64 = mem_cgroup_read,
4149 },
4150 {
Balbir Singh8cdea7c2008-02-07 00:13:50 -08004151 .name = "failcnt",
KAMEZAWA Hiroyuki8c7c6e32009-01-07 18:08:00 -08004152 .private = MEMFILE_PRIVATE(_MEM, RES_FAILCNT),
Pavel Emelyanov29f2a4d2008-04-29 01:00:21 -07004153 .trigger = mem_cgroup_reset,
Paul Menage2c3daa72008-04-29 00:59:58 -07004154 .read_u64 = mem_cgroup_read,
Balbir Singh8cdea7c2008-02-07 00:13:50 -08004155 },
Balbir Singh8697d332008-02-07 00:13:59 -08004156 {
KAMEZAWA Hiroyukid2ceb9b2008-02-07 00:14:25 -08004157 .name = "stat",
Paul Menagec64745c2008-04-29 01:00:02 -07004158 .read_map = mem_control_stat_show,
KAMEZAWA Hiroyukid2ceb9b2008-02-07 00:14:25 -08004159 },
KAMEZAWA Hiroyukic1e862c2009-01-07 18:07:55 -08004160 {
4161 .name = "force_empty",
4162 .trigger = mem_cgroup_force_empty_write,
4163 },
Balbir Singh18f59ea2009-01-07 18:08:07 -08004164 {
4165 .name = "use_hierarchy",
4166 .write_u64 = mem_cgroup_hierarchy_write,
4167 .read_u64 = mem_cgroup_hierarchy_read,
4168 },
KOSAKI Motohiroa7885eb2009-01-07 18:08:24 -08004169 {
4170 .name = "swappiness",
4171 .read_u64 = mem_cgroup_swappiness_read,
4172 .write_u64 = mem_cgroup_swappiness_write,
4173 },
Daisuke Nishimura7dc74be2010-03-10 15:22:13 -08004174 {
4175 .name = "move_charge_at_immigrate",
4176 .read_u64 = mem_cgroup_move_charge_read,
4177 .write_u64 = mem_cgroup_move_charge_write,
4178 },
KAMEZAWA Hiroyuki9490ff22010-05-26 14:42:36 -07004179 {
4180 .name = "oom_control",
KAMEZAWA Hiroyuki3c11ecf2010-05-26 14:42:37 -07004181 .read_map = mem_cgroup_oom_control_read,
4182 .write_u64 = mem_cgroup_oom_control_write,
KAMEZAWA Hiroyuki9490ff22010-05-26 14:42:36 -07004183 .register_event = mem_cgroup_oom_register_event,
4184 .unregister_event = mem_cgroup_oom_unregister_event,
4185 .private = MEMFILE_PRIVATE(_OOM_TYPE, OOM_CONTROL),
4186 },
Balbir Singh8cdea7c2008-02-07 00:13:50 -08004187};
4188
KAMEZAWA Hiroyuki8c7c6e32009-01-07 18:08:00 -08004189#ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP
4190static struct cftype memsw_cgroup_files[] = {
4191 {
4192 .name = "memsw.usage_in_bytes",
4193 .private = MEMFILE_PRIVATE(_MEMSWAP, RES_USAGE),
4194 .read_u64 = mem_cgroup_read,
KAMEZAWA Hiroyuki9490ff22010-05-26 14:42:36 -07004195 .register_event = mem_cgroup_usage_register_event,
4196 .unregister_event = mem_cgroup_usage_unregister_event,
KAMEZAWA Hiroyuki8c7c6e32009-01-07 18:08:00 -08004197 },
4198 {
4199 .name = "memsw.max_usage_in_bytes",
4200 .private = MEMFILE_PRIVATE(_MEMSWAP, RES_MAX_USAGE),
4201 .trigger = mem_cgroup_reset,
4202 .read_u64 = mem_cgroup_read,
4203 },
4204 {
4205 .name = "memsw.limit_in_bytes",
4206 .private = MEMFILE_PRIVATE(_MEMSWAP, RES_LIMIT),
4207 .write_string = mem_cgroup_write,
4208 .read_u64 = mem_cgroup_read,
4209 },
4210 {
4211 .name = "memsw.failcnt",
4212 .private = MEMFILE_PRIVATE(_MEMSWAP, RES_FAILCNT),
4213 .trigger = mem_cgroup_reset,
4214 .read_u64 = mem_cgroup_read,
4215 },
4216};
4217
4218static int register_memsw_files(struct cgroup *cont, struct cgroup_subsys *ss)
4219{
4220 if (!do_swap_account)
4221 return 0;
4222 return cgroup_add_files(cont, ss, memsw_cgroup_files,
4223 ARRAY_SIZE(memsw_cgroup_files));
4224};
4225#else
4226static int register_memsw_files(struct cgroup *cont, struct cgroup_subsys *ss)
4227{
4228 return 0;
4229}
4230#endif
4231
KAMEZAWA Hiroyuki6d12e2d2008-02-07 00:14:31 -08004232static int alloc_mem_cgroup_per_zone_info(struct mem_cgroup *mem, int node)
4233{
4234 struct mem_cgroup_per_node *pn;
KAMEZAWA Hiroyuki1ecaab22008-02-07 00:14:38 -08004235 struct mem_cgroup_per_zone *mz;
Christoph Lameterb69408e2008-10-18 20:26:14 -07004236 enum lru_list l;
KAMEZAWA Hiroyuki41e33552008-04-08 17:41:54 -07004237 int zone, tmp = node;
KAMEZAWA Hiroyuki1ecaab22008-02-07 00:14:38 -08004238 /*
4239 * This routine is called against possible nodes.
4240 * But it's BUG to call kmalloc() against offline node.
4241 *
4242 * TODO: this routine can waste much memory for nodes which will
4243 * never be onlined. It's better to use memory hotplug callback
4244 * function.
4245 */
KAMEZAWA Hiroyuki41e33552008-04-08 17:41:54 -07004246 if (!node_state(node, N_NORMAL_MEMORY))
4247 tmp = -1;
Jesper Juhl17295c82011-01-13 15:47:42 -08004248 pn = kzalloc_node(sizeof(*pn), GFP_KERNEL, tmp);
KAMEZAWA Hiroyuki6d12e2d2008-02-07 00:14:31 -08004249 if (!pn)
4250 return 1;
KAMEZAWA Hiroyuki1ecaab22008-02-07 00:14:38 -08004251
KAMEZAWA Hiroyuki6d12e2d2008-02-07 00:14:31 -08004252 mem->info.nodeinfo[node] = pn;
KAMEZAWA Hiroyuki1ecaab22008-02-07 00:14:38 -08004253 for (zone = 0; zone < MAX_NR_ZONES; zone++) {
4254 mz = &pn->zoneinfo[zone];
Christoph Lameterb69408e2008-10-18 20:26:14 -07004255 for_each_lru(l)
4256 INIT_LIST_HEAD(&mz->lists[l]);
Balbir Singhf64c3f52009-09-23 15:56:37 -07004257 mz->usage_in_excess = 0;
Balbir Singh4e416952009-09-23 15:56:39 -07004258 mz->on_tree = false;
4259 mz->mem = mem;
KAMEZAWA Hiroyuki1ecaab22008-02-07 00:14:38 -08004260 }
KAMEZAWA Hiroyuki6d12e2d2008-02-07 00:14:31 -08004261 return 0;
4262}
4263
KAMEZAWA Hiroyuki1ecaab22008-02-07 00:14:38 -08004264static void free_mem_cgroup_per_zone_info(struct mem_cgroup *mem, int node)
4265{
4266 kfree(mem->info.nodeinfo[node]);
4267}
4268
KAMEZAWA Hiroyuki33327942008-04-29 01:00:24 -07004269static struct mem_cgroup *mem_cgroup_alloc(void)
4270{
4271 struct mem_cgroup *mem;
KAMEZAWA Hiroyukic62b1a32010-03-10 15:22:29 -08004272 int size = sizeof(struct mem_cgroup);
KAMEZAWA Hiroyuki33327942008-04-29 01:00:24 -07004273
KAMEZAWA Hiroyukic62b1a32010-03-10 15:22:29 -08004274 /* Can be very big if MAX_NUMNODES is very big */
Jan Blunckc8dad2b2009-01-07 18:07:53 -08004275 if (size < PAGE_SIZE)
Jesper Juhl17295c82011-01-13 15:47:42 -08004276 mem = kzalloc(size, GFP_KERNEL);
KAMEZAWA Hiroyuki33327942008-04-29 01:00:24 -07004277 else
Jesper Juhl17295c82011-01-13 15:47:42 -08004278 mem = vzalloc(size);
KAMEZAWA Hiroyuki33327942008-04-29 01:00:24 -07004279
Dan Carpentere7bbcdf2010-03-23 13:35:12 -07004280 if (!mem)
4281 return NULL;
4282
KAMEZAWA Hiroyukic62b1a32010-03-10 15:22:29 -08004283 mem->stat = alloc_percpu(struct mem_cgroup_stat_cpu);
Dan Carpenterd2e61b82010-11-11 14:05:12 -08004284 if (!mem->stat)
4285 goto out_free;
KAMEZAWA Hiroyuki711d3d22010-10-27 15:33:42 -07004286 spin_lock_init(&mem->pcp_counter_lock);
KAMEZAWA Hiroyuki33327942008-04-29 01:00:24 -07004287 return mem;
Dan Carpenterd2e61b82010-11-11 14:05:12 -08004288
4289out_free:
4290 if (size < PAGE_SIZE)
4291 kfree(mem);
4292 else
4293 vfree(mem);
4294 return NULL;
KAMEZAWA Hiroyuki33327942008-04-29 01:00:24 -07004295}
4296
KAMEZAWA Hiroyuki8c7c6e32009-01-07 18:08:00 -08004297/*
4298 * At destroying mem_cgroup, references from swap_cgroup can remain.
4299 * (scanning all at force_empty is too costly...)
4300 *
4301 * Instead of clearing all references at force_empty, we remember
4302 * the number of reference from swap_cgroup and free mem_cgroup when
4303 * it goes down to 0.
4304 *
KAMEZAWA Hiroyuki8c7c6e32009-01-07 18:08:00 -08004305 * Removal of cgroup itself succeeds regardless of refs from swap.
4306 */
4307
KAMEZAWA Hiroyukia7ba0ee2009-01-07 18:08:32 -08004308static void __mem_cgroup_free(struct mem_cgroup *mem)
KAMEZAWA Hiroyuki33327942008-04-29 01:00:24 -07004309{
KAMEZAWA Hiroyuki08e552c2009-01-07 18:08:01 -08004310 int node;
4311
Balbir Singhf64c3f52009-09-23 15:56:37 -07004312 mem_cgroup_remove_from_trees(mem);
KAMEZAWA Hiroyuki04046e12009-04-02 16:57:33 -07004313 free_css_id(&mem_cgroup_subsys, &mem->css);
4314
KAMEZAWA Hiroyuki08e552c2009-01-07 18:08:01 -08004315 for_each_node_state(node, N_POSSIBLE)
4316 free_mem_cgroup_per_zone_info(mem, node);
4317
KAMEZAWA Hiroyukic62b1a32010-03-10 15:22:29 -08004318 free_percpu(mem->stat);
4319 if (sizeof(struct mem_cgroup) < PAGE_SIZE)
KAMEZAWA Hiroyuki33327942008-04-29 01:00:24 -07004320 kfree(mem);
4321 else
4322 vfree(mem);
4323}
4324
KAMEZAWA Hiroyuki8c7c6e32009-01-07 18:08:00 -08004325static void mem_cgroup_get(struct mem_cgroup *mem)
4326{
4327 atomic_inc(&mem->refcnt);
4328}
4329
Daisuke Nishimura483c30b2010-03-10 15:22:18 -08004330static void __mem_cgroup_put(struct mem_cgroup *mem, int count)
KAMEZAWA Hiroyuki8c7c6e32009-01-07 18:08:00 -08004331{
Daisuke Nishimura483c30b2010-03-10 15:22:18 -08004332 if (atomic_sub_and_test(count, &mem->refcnt)) {
Daisuke Nishimura7bcc1bb2009-01-29 14:25:11 -08004333 struct mem_cgroup *parent = parent_mem_cgroup(mem);
KAMEZAWA Hiroyukia7ba0ee2009-01-07 18:08:32 -08004334 __mem_cgroup_free(mem);
Daisuke Nishimura7bcc1bb2009-01-29 14:25:11 -08004335 if (parent)
4336 mem_cgroup_put(parent);
4337 }
KAMEZAWA Hiroyuki8c7c6e32009-01-07 18:08:00 -08004338}
4339
Daisuke Nishimura483c30b2010-03-10 15:22:18 -08004340static void mem_cgroup_put(struct mem_cgroup *mem)
4341{
4342 __mem_cgroup_put(mem, 1);
4343}
4344
Daisuke Nishimura7bcc1bb2009-01-29 14:25:11 -08004345/*
4346 * Returns the parent mem_cgroup in memcgroup hierarchy with hierarchy enabled.
4347 */
4348static struct mem_cgroup *parent_mem_cgroup(struct mem_cgroup *mem)
4349{
4350 if (!mem->res.parent)
4351 return NULL;
4352 return mem_cgroup_from_res_counter(mem->res.parent, res);
4353}
KAMEZAWA Hiroyuki33327942008-04-29 01:00:24 -07004354
KAMEZAWA Hiroyukic0777192009-01-07 18:07:57 -08004355#ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP
4356static void __init enable_swap_cgroup(void)
4357{
Hirokazu Takahashif8d66542009-01-07 18:08:02 -08004358 if (!mem_cgroup_disabled() && really_do_swap_account)
KAMEZAWA Hiroyukic0777192009-01-07 18:07:57 -08004359 do_swap_account = 1;
4360}
4361#else
4362static void __init enable_swap_cgroup(void)
4363{
4364}
4365#endif
4366
Balbir Singhf64c3f52009-09-23 15:56:37 -07004367static int mem_cgroup_soft_limit_tree_init(void)
4368{
4369 struct mem_cgroup_tree_per_node *rtpn;
4370 struct mem_cgroup_tree_per_zone *rtpz;
4371 int tmp, node, zone;
4372
4373 for_each_node_state(node, N_POSSIBLE) {
4374 tmp = node;
4375 if (!node_state(node, N_NORMAL_MEMORY))
4376 tmp = -1;
4377 rtpn = kzalloc_node(sizeof(*rtpn), GFP_KERNEL, tmp);
4378 if (!rtpn)
4379 return 1;
4380
4381 soft_limit_tree.rb_tree_per_node[node] = rtpn;
4382
4383 for (zone = 0; zone < MAX_NR_ZONES; zone++) {
4384 rtpz = &rtpn->rb_tree_per_zone[zone];
4385 rtpz->rb_root = RB_ROOT;
4386 spin_lock_init(&rtpz->lock);
4387 }
4388 }
4389 return 0;
4390}
4391
Li Zefan0eb253e2009-01-15 13:51:25 -08004392static struct cgroup_subsys_state * __ref
Balbir Singh8cdea7c2008-02-07 00:13:50 -08004393mem_cgroup_create(struct cgroup_subsys *ss, struct cgroup *cont)
4394{
Balbir Singh28dbc4b2009-01-07 18:08:05 -08004395 struct mem_cgroup *mem, *parent;
KAMEZAWA Hiroyuki04046e12009-04-02 16:57:33 -07004396 long error = -ENOMEM;
KAMEZAWA Hiroyuki6d12e2d2008-02-07 00:14:31 -08004397 int node;
Balbir Singh8cdea7c2008-02-07 00:13:50 -08004398
Jan Blunckc8dad2b2009-01-07 18:07:53 -08004399 mem = mem_cgroup_alloc();
4400 if (!mem)
KAMEZAWA Hiroyuki04046e12009-04-02 16:57:33 -07004401 return ERR_PTR(error);
Pavel Emelianov78fb7462008-02-07 00:13:51 -08004402
KAMEZAWA Hiroyuki6d12e2d2008-02-07 00:14:31 -08004403 for_each_node_state(node, N_POSSIBLE)
4404 if (alloc_mem_cgroup_per_zone_info(mem, node))
4405 goto free_out;
Balbir Singhf64c3f52009-09-23 15:56:37 -07004406
KAMEZAWA Hiroyukic0777192009-01-07 18:07:57 -08004407 /* root ? */
Balbir Singh28dbc4b2009-01-07 18:08:05 -08004408 if (cont->parent == NULL) {
KAMEZAWA Hiroyukicdec2e42009-12-15 16:47:08 -08004409 int cpu;
KAMEZAWA Hiroyukic0777192009-01-07 18:07:57 -08004410 enable_swap_cgroup();
Balbir Singh28dbc4b2009-01-07 18:08:05 -08004411 parent = NULL;
Balbir Singh4b3bde42009-09-23 15:56:32 -07004412 root_mem_cgroup = mem;
Balbir Singhf64c3f52009-09-23 15:56:37 -07004413 if (mem_cgroup_soft_limit_tree_init())
4414 goto free_out;
KAMEZAWA Hiroyukicdec2e42009-12-15 16:47:08 -08004415 for_each_possible_cpu(cpu) {
4416 struct memcg_stock_pcp *stock =
4417 &per_cpu(memcg_stock, cpu);
4418 INIT_WORK(&stock->work, drain_local_stock);
4419 }
KAMEZAWA Hiroyuki711d3d22010-10-27 15:33:42 -07004420 hotcpu_notifier(memcg_cpu_hotplug_callback, 0);
Balbir Singh18f59ea2009-01-07 18:08:07 -08004421 } else {
Balbir Singh28dbc4b2009-01-07 18:08:05 -08004422 parent = mem_cgroup_from_cont(cont->parent);
Balbir Singh18f59ea2009-01-07 18:08:07 -08004423 mem->use_hierarchy = parent->use_hierarchy;
KAMEZAWA Hiroyuki3c11ecf2010-05-26 14:42:37 -07004424 mem->oom_kill_disable = parent->oom_kill_disable;
Balbir Singh18f59ea2009-01-07 18:08:07 -08004425 }
Balbir Singh28dbc4b2009-01-07 18:08:05 -08004426
Balbir Singh18f59ea2009-01-07 18:08:07 -08004427 if (parent && parent->use_hierarchy) {
4428 res_counter_init(&mem->res, &parent->res);
4429 res_counter_init(&mem->memsw, &parent->memsw);
Daisuke Nishimura7bcc1bb2009-01-29 14:25:11 -08004430 /*
4431 * We increment refcnt of the parent to ensure that we can
4432 * safely access it on res_counter_charge/uncharge.
4433 * This refcnt will be decremented when freeing this
4434 * mem_cgroup(see mem_cgroup_put).
4435 */
4436 mem_cgroup_get(parent);
Balbir Singh18f59ea2009-01-07 18:08:07 -08004437 } else {
4438 res_counter_init(&mem->res, NULL);
4439 res_counter_init(&mem->memsw, NULL);
4440 }
KAMEZAWA Hiroyuki04046e12009-04-02 16:57:33 -07004441 mem->last_scanned_child = 0;
KOSAKI Motohiro2733c062009-01-07 18:08:23 -08004442 spin_lock_init(&mem->reclaim_param_lock);
KAMEZAWA Hiroyuki9490ff22010-05-26 14:42:36 -07004443 INIT_LIST_HEAD(&mem->oom_notify);
Balbir Singh6d61ef42009-01-07 18:08:06 -08004444
KOSAKI Motohiroa7885eb2009-01-07 18:08:24 -08004445 if (parent)
4446 mem->swappiness = get_swappiness(parent);
KAMEZAWA Hiroyukia7ba0ee2009-01-07 18:08:32 -08004447 atomic_set(&mem->refcnt, 1);
Daisuke Nishimura7dc74be2010-03-10 15:22:13 -08004448 mem->move_charge_at_immigrate = 0;
Kirill A. Shutemov2e72b632010-03-10 15:22:24 -08004449 mutex_init(&mem->thresholds_lock);
Balbir Singh8cdea7c2008-02-07 00:13:50 -08004450 return &mem->css;
KAMEZAWA Hiroyuki6d12e2d2008-02-07 00:14:31 -08004451free_out:
KAMEZAWA Hiroyukia7ba0ee2009-01-07 18:08:32 -08004452 __mem_cgroup_free(mem);
Balbir Singh4b3bde42009-09-23 15:56:32 -07004453 root_mem_cgroup = NULL;
KAMEZAWA Hiroyuki04046e12009-04-02 16:57:33 -07004454 return ERR_PTR(error);
Balbir Singh8cdea7c2008-02-07 00:13:50 -08004455}
4456
KAMEZAWA Hiroyukiec64f512009-04-02 16:57:26 -07004457static int mem_cgroup_pre_destroy(struct cgroup_subsys *ss,
KAMEZAWA Hiroyukidf878fb2008-02-07 00:14:28 -08004458 struct cgroup *cont)
4459{
4460 struct mem_cgroup *mem = mem_cgroup_from_cont(cont);
KAMEZAWA Hiroyukiec64f512009-04-02 16:57:26 -07004461
4462 return mem_cgroup_force_empty(mem, false);
KAMEZAWA Hiroyukidf878fb2008-02-07 00:14:28 -08004463}
4464
Balbir Singh8cdea7c2008-02-07 00:13:50 -08004465static void mem_cgroup_destroy(struct cgroup_subsys *ss,
4466 struct cgroup *cont)
4467{
Daisuke Nishimurac268e992009-01-15 13:51:13 -08004468 struct mem_cgroup *mem = mem_cgroup_from_cont(cont);
Daisuke Nishimurac268e992009-01-15 13:51:13 -08004469
Daisuke Nishimurac268e992009-01-15 13:51:13 -08004470 mem_cgroup_put(mem);
Balbir Singh8cdea7c2008-02-07 00:13:50 -08004471}
4472
4473static int mem_cgroup_populate(struct cgroup_subsys *ss,
4474 struct cgroup *cont)
4475{
KAMEZAWA Hiroyuki8c7c6e32009-01-07 18:08:00 -08004476 int ret;
4477
4478 ret = cgroup_add_files(cont, ss, mem_cgroup_files,
4479 ARRAY_SIZE(mem_cgroup_files));
4480
4481 if (!ret)
4482 ret = register_memsw_files(cont, ss);
4483 return ret;
Balbir Singh8cdea7c2008-02-07 00:13:50 -08004484}
4485
Daisuke Nishimura02491442010-03-10 15:22:17 -08004486#ifdef CONFIG_MMU
Daisuke Nishimura7dc74be2010-03-10 15:22:13 -08004487/* Handlers for move charge at task migration. */
Daisuke Nishimura854ffa82010-03-10 15:22:15 -08004488#define PRECHARGE_COUNT_AT_ONCE 256
4489static int mem_cgroup_do_precharge(unsigned long count)
Daisuke Nishimura7dc74be2010-03-10 15:22:13 -08004490{
Daisuke Nishimura854ffa82010-03-10 15:22:15 -08004491 int ret = 0;
4492 int batch_count = PRECHARGE_COUNT_AT_ONCE;
Daisuke Nishimura4ffef5f2010-03-10 15:22:14 -08004493 struct mem_cgroup *mem = mc.to;
4494
Daisuke Nishimura854ffa82010-03-10 15:22:15 -08004495 if (mem_cgroup_is_root(mem)) {
4496 mc.precharge += count;
4497 /* we don't need css_get for root */
4498 return ret;
4499 }
4500 /* try to charge at once */
4501 if (count > 1) {
4502 struct res_counter *dummy;
4503 /*
4504 * "mem" cannot be under rmdir() because we've already checked
4505 * by cgroup_lock_live_cgroup() that it is not removed and we
4506 * are still under the same cgroup_mutex. So we can postpone
4507 * css_get().
4508 */
4509 if (res_counter_charge(&mem->res, PAGE_SIZE * count, &dummy))
4510 goto one_by_one;
4511 if (do_swap_account && res_counter_charge(&mem->memsw,
4512 PAGE_SIZE * count, &dummy)) {
4513 res_counter_uncharge(&mem->res, PAGE_SIZE * count);
4514 goto one_by_one;
4515 }
4516 mc.precharge += count;
Daisuke Nishimura854ffa82010-03-10 15:22:15 -08004517 return ret;
4518 }
4519one_by_one:
4520 /* fall back to one by one charge */
4521 while (count--) {
4522 if (signal_pending(current)) {
4523 ret = -EINTR;
4524 break;
4525 }
4526 if (!batch_count--) {
4527 batch_count = PRECHARGE_COUNT_AT_ONCE;
4528 cond_resched();
4529 }
Andrea Arcangeliec168512011-01-13 15:46:56 -08004530 ret = __mem_cgroup_try_charge(NULL, GFP_KERNEL, &mem, false,
4531 PAGE_SIZE);
Daisuke Nishimura854ffa82010-03-10 15:22:15 -08004532 if (ret || !mem)
4533 /* mem_cgroup_clear_mc() will do uncharge later */
4534 return -ENOMEM;
4535 mc.precharge++;
4536 }
Daisuke Nishimura4ffef5f2010-03-10 15:22:14 -08004537 return ret;
4538}
4539
4540/**
4541 * is_target_pte_for_mc - check a pte whether it is valid for move charge
4542 * @vma: the vma the pte to be checked belongs
4543 * @addr: the address corresponding to the pte to be checked
4544 * @ptent: the pte to be checked
Daisuke Nishimura02491442010-03-10 15:22:17 -08004545 * @target: the pointer the target page or swap ent will be stored(can be NULL)
Daisuke Nishimura4ffef5f2010-03-10 15:22:14 -08004546 *
4547 * Returns
4548 * 0(MC_TARGET_NONE): if the pte is not a target for move charge.
4549 * 1(MC_TARGET_PAGE): if the page corresponding to this pte is a target for
4550 * move charge. if @target is not NULL, the page is stored in target->page
4551 * with extra refcnt got(Callers should handle it).
Daisuke Nishimura02491442010-03-10 15:22:17 -08004552 * 2(MC_TARGET_SWAP): if the swap entry corresponding to this pte is a
4553 * target for charge migration. if @target is not NULL, the entry is stored
4554 * in target->ent.
Daisuke Nishimura4ffef5f2010-03-10 15:22:14 -08004555 *
4556 * Called with pte lock held.
4557 */
Daisuke Nishimura4ffef5f2010-03-10 15:22:14 -08004558union mc_target {
4559 struct page *page;
Daisuke Nishimura02491442010-03-10 15:22:17 -08004560 swp_entry_t ent;
Daisuke Nishimura4ffef5f2010-03-10 15:22:14 -08004561};
4562
Daisuke Nishimura4ffef5f2010-03-10 15:22:14 -08004563enum mc_target_type {
4564 MC_TARGET_NONE, /* not used */
4565 MC_TARGET_PAGE,
Daisuke Nishimura02491442010-03-10 15:22:17 -08004566 MC_TARGET_SWAP,
Daisuke Nishimura4ffef5f2010-03-10 15:22:14 -08004567};
4568
Daisuke Nishimura90254a62010-05-26 14:42:38 -07004569static struct page *mc_handle_present_pte(struct vm_area_struct *vma,
4570 unsigned long addr, pte_t ptent)
4571{
4572 struct page *page = vm_normal_page(vma, addr, ptent);
4573
4574 if (!page || !page_mapped(page))
4575 return NULL;
4576 if (PageAnon(page)) {
4577 /* we don't move shared anon */
4578 if (!move_anon() || page_mapcount(page) > 2)
4579 return NULL;
Daisuke Nishimura87946a72010-05-26 14:42:39 -07004580 } else if (!move_file())
4581 /* we ignore mapcount for file pages */
Daisuke Nishimura90254a62010-05-26 14:42:38 -07004582 return NULL;
4583 if (!get_page_unless_zero(page))
4584 return NULL;
4585
4586 return page;
4587}
4588
4589static struct page *mc_handle_swap_pte(struct vm_area_struct *vma,
4590 unsigned long addr, pte_t ptent, swp_entry_t *entry)
4591{
4592 int usage_count;
4593 struct page *page = NULL;
4594 swp_entry_t ent = pte_to_swp_entry(ptent);
4595
4596 if (!move_anon() || non_swap_entry(ent))
4597 return NULL;
4598 usage_count = mem_cgroup_count_swap_user(ent, &page);
4599 if (usage_count > 1) { /* we don't move shared anon */
4600 if (page)
4601 put_page(page);
4602 return NULL;
4603 }
4604 if (do_swap_account)
4605 entry->val = ent.val;
4606
4607 return page;
4608}
4609
Daisuke Nishimura87946a72010-05-26 14:42:39 -07004610static struct page *mc_handle_file_pte(struct vm_area_struct *vma,
4611 unsigned long addr, pte_t ptent, swp_entry_t *entry)
4612{
4613 struct page *page = NULL;
4614 struct inode *inode;
4615 struct address_space *mapping;
4616 pgoff_t pgoff;
4617
4618 if (!vma->vm_file) /* anonymous vma */
4619 return NULL;
4620 if (!move_file())
4621 return NULL;
4622
4623 inode = vma->vm_file->f_path.dentry->d_inode;
4624 mapping = vma->vm_file->f_mapping;
4625 if (pte_none(ptent))
4626 pgoff = linear_page_index(vma, addr);
4627 else /* pte_file(ptent) is true */
4628 pgoff = pte_to_pgoff(ptent);
4629
4630 /* page is moved even if it's not RSS of this task(page-faulted). */
4631 if (!mapping_cap_swap_backed(mapping)) { /* normal file */
4632 page = find_get_page(mapping, pgoff);
4633 } else { /* shmem/tmpfs file. we should take account of swap too. */
4634 swp_entry_t ent;
4635 mem_cgroup_get_shmem_target(inode, pgoff, &page, &ent);
4636 if (do_swap_account)
4637 entry->val = ent.val;
4638 }
4639
4640 return page;
4641}
4642
Daisuke Nishimura4ffef5f2010-03-10 15:22:14 -08004643static int is_target_pte_for_mc(struct vm_area_struct *vma,
4644 unsigned long addr, pte_t ptent, union mc_target *target)
4645{
Daisuke Nishimura02491442010-03-10 15:22:17 -08004646 struct page *page = NULL;
Daisuke Nishimura4ffef5f2010-03-10 15:22:14 -08004647 struct page_cgroup *pc;
4648 int ret = 0;
Daisuke Nishimura02491442010-03-10 15:22:17 -08004649 swp_entry_t ent = { .val = 0 };
Daisuke Nishimura4ffef5f2010-03-10 15:22:14 -08004650
Daisuke Nishimura90254a62010-05-26 14:42:38 -07004651 if (pte_present(ptent))
4652 page = mc_handle_present_pte(vma, addr, ptent);
4653 else if (is_swap_pte(ptent))
4654 page = mc_handle_swap_pte(vma, addr, ptent, &ent);
Daisuke Nishimura87946a72010-05-26 14:42:39 -07004655 else if (pte_none(ptent) || pte_file(ptent))
4656 page = mc_handle_file_pte(vma, addr, ptent, &ent);
Daisuke Nishimura90254a62010-05-26 14:42:38 -07004657
4658 if (!page && !ent.val)
Daisuke Nishimura02491442010-03-10 15:22:17 -08004659 return 0;
Daisuke Nishimura02491442010-03-10 15:22:17 -08004660 if (page) {
4661 pc = lookup_page_cgroup(page);
4662 /*
4663 * Do only loose check w/o page_cgroup lock.
4664 * mem_cgroup_move_account() checks the pc is valid or not under
4665 * the lock.
4666 */
4667 if (PageCgroupUsed(pc) && pc->mem_cgroup == mc.from) {
4668 ret = MC_TARGET_PAGE;
4669 if (target)
4670 target->page = page;
4671 }
4672 if (!ret || !target)
4673 put_page(page);
4674 }
Daisuke Nishimura90254a62010-05-26 14:42:38 -07004675 /* There is a swap entry and a page doesn't exist or isn't charged */
4676 if (ent.val && !ret &&
KAMEZAWA Hiroyuki7f0f1542010-05-11 14:06:58 -07004677 css_id(&mc.from->css) == lookup_swap_cgroup(ent)) {
4678 ret = MC_TARGET_SWAP;
4679 if (target)
4680 target->ent = ent;
Daisuke Nishimura02491442010-03-10 15:22:17 -08004681 }
Daisuke Nishimura4ffef5f2010-03-10 15:22:14 -08004682 return ret;
4683}
4684
4685static int mem_cgroup_count_precharge_pte_range(pmd_t *pmd,
4686 unsigned long addr, unsigned long end,
4687 struct mm_walk *walk)
4688{
4689 struct vm_area_struct *vma = walk->private;
4690 pte_t *pte;
4691 spinlock_t *ptl;
4692
Andrea Arcangeliec168512011-01-13 15:46:56 -08004693 VM_BUG_ON(pmd_trans_huge(*pmd));
Daisuke Nishimura4ffef5f2010-03-10 15:22:14 -08004694 pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl);
4695 for (; addr != end; pte++, addr += PAGE_SIZE)
4696 if (is_target_pte_for_mc(vma, addr, *pte, NULL))
4697 mc.precharge++; /* increment precharge temporarily */
4698 pte_unmap_unlock(pte - 1, ptl);
4699 cond_resched();
4700
Daisuke Nishimura7dc74be2010-03-10 15:22:13 -08004701 return 0;
4702}
4703
Daisuke Nishimura4ffef5f2010-03-10 15:22:14 -08004704static unsigned long mem_cgroup_count_precharge(struct mm_struct *mm)
4705{
4706 unsigned long precharge;
4707 struct vm_area_struct *vma;
4708
Daisuke Nishimuradfe076b2011-01-13 15:47:41 -08004709 down_read(&mm->mmap_sem);
Daisuke Nishimura4ffef5f2010-03-10 15:22:14 -08004710 for (vma = mm->mmap; vma; vma = vma->vm_next) {
4711 struct mm_walk mem_cgroup_count_precharge_walk = {
4712 .pmd_entry = mem_cgroup_count_precharge_pte_range,
4713 .mm = mm,
4714 .private = vma,
4715 };
4716 if (is_vm_hugetlb_page(vma))
4717 continue;
Daisuke Nishimura4ffef5f2010-03-10 15:22:14 -08004718 walk_page_range(vma->vm_start, vma->vm_end,
4719 &mem_cgroup_count_precharge_walk);
4720 }
Daisuke Nishimuradfe076b2011-01-13 15:47:41 -08004721 up_read(&mm->mmap_sem);
Daisuke Nishimura4ffef5f2010-03-10 15:22:14 -08004722
4723 precharge = mc.precharge;
4724 mc.precharge = 0;
4725
4726 return precharge;
4727}
4728
Daisuke Nishimura4ffef5f2010-03-10 15:22:14 -08004729static int mem_cgroup_precharge_mc(struct mm_struct *mm)
4730{
Daisuke Nishimuradfe076b2011-01-13 15:47:41 -08004731 unsigned long precharge = mem_cgroup_count_precharge(mm);
4732
4733 VM_BUG_ON(mc.moving_task);
4734 mc.moving_task = current;
4735 return mem_cgroup_do_precharge(precharge);
Daisuke Nishimura4ffef5f2010-03-10 15:22:14 -08004736}
4737
Daisuke Nishimuradfe076b2011-01-13 15:47:41 -08004738/* cancels all extra charges on mc.from and mc.to, and wakes up all waiters. */
4739static void __mem_cgroup_clear_mc(void)
Daisuke Nishimura4ffef5f2010-03-10 15:22:14 -08004740{
KAMEZAWA Hiroyuki2bd9bb22010-08-10 18:02:58 -07004741 struct mem_cgroup *from = mc.from;
4742 struct mem_cgroup *to = mc.to;
4743
Daisuke Nishimura4ffef5f2010-03-10 15:22:14 -08004744 /* we must uncharge all the leftover precharges from mc.to */
Daisuke Nishimura854ffa82010-03-10 15:22:15 -08004745 if (mc.precharge) {
4746 __mem_cgroup_cancel_charge(mc.to, mc.precharge);
4747 mc.precharge = 0;
4748 }
4749 /*
4750 * we didn't uncharge from mc.from at mem_cgroup_move_account(), so
4751 * we must uncharge here.
4752 */
4753 if (mc.moved_charge) {
4754 __mem_cgroup_cancel_charge(mc.from, mc.moved_charge);
4755 mc.moved_charge = 0;
Daisuke Nishimura4ffef5f2010-03-10 15:22:14 -08004756 }
Daisuke Nishimura483c30b2010-03-10 15:22:18 -08004757 /* we must fixup refcnts and charges */
4758 if (mc.moved_swap) {
Daisuke Nishimura483c30b2010-03-10 15:22:18 -08004759 /* uncharge swap account from the old cgroup */
4760 if (!mem_cgroup_is_root(mc.from))
4761 res_counter_uncharge(&mc.from->memsw,
4762 PAGE_SIZE * mc.moved_swap);
4763 __mem_cgroup_put(mc.from, mc.moved_swap);
4764
4765 if (!mem_cgroup_is_root(mc.to)) {
4766 /*
4767 * we charged both to->res and to->memsw, so we should
4768 * uncharge to->res.
4769 */
4770 res_counter_uncharge(&mc.to->res,
4771 PAGE_SIZE * mc.moved_swap);
Daisuke Nishimura483c30b2010-03-10 15:22:18 -08004772 }
4773 /* we've already done mem_cgroup_get(mc.to) */
Daisuke Nishimura483c30b2010-03-10 15:22:18 -08004774 mc.moved_swap = 0;
4775 }
Daisuke Nishimuradfe076b2011-01-13 15:47:41 -08004776 memcg_oom_recover(from);
4777 memcg_oom_recover(to);
4778 wake_up_all(&mc.waitq);
4779}
4780
4781static void mem_cgroup_clear_mc(void)
4782{
4783 struct mem_cgroup *from = mc.from;
4784
4785 /*
4786 * we must clear moving_task before waking up waiters at the end of
4787 * task migration.
4788 */
4789 mc.moving_task = NULL;
4790 __mem_cgroup_clear_mc();
KAMEZAWA Hiroyuki2bd9bb22010-08-10 18:02:58 -07004791 spin_lock(&mc.lock);
Daisuke Nishimura4ffef5f2010-03-10 15:22:14 -08004792 mc.from = NULL;
4793 mc.to = NULL;
KAMEZAWA Hiroyuki2bd9bb22010-08-10 18:02:58 -07004794 spin_unlock(&mc.lock);
KAMEZAWA Hiroyuki32047e22010-10-27 15:33:40 -07004795 mem_cgroup_end_move(from);
Daisuke Nishimura4ffef5f2010-03-10 15:22:14 -08004796}
4797
Daisuke Nishimura7dc74be2010-03-10 15:22:13 -08004798static int mem_cgroup_can_attach(struct cgroup_subsys *ss,
4799 struct cgroup *cgroup,
4800 struct task_struct *p,
4801 bool threadgroup)
4802{
4803 int ret = 0;
4804 struct mem_cgroup *mem = mem_cgroup_from_cont(cgroup);
4805
4806 if (mem->move_charge_at_immigrate) {
4807 struct mm_struct *mm;
4808 struct mem_cgroup *from = mem_cgroup_from_task(p);
4809
4810 VM_BUG_ON(from == mem);
4811
4812 mm = get_task_mm(p);
4813 if (!mm)
4814 return 0;
Daisuke Nishimura7dc74be2010-03-10 15:22:13 -08004815 /* We move charges only when we move a owner of the mm */
Daisuke Nishimura4ffef5f2010-03-10 15:22:14 -08004816 if (mm->owner == p) {
4817 VM_BUG_ON(mc.from);
4818 VM_BUG_ON(mc.to);
4819 VM_BUG_ON(mc.precharge);
Daisuke Nishimura854ffa82010-03-10 15:22:15 -08004820 VM_BUG_ON(mc.moved_charge);
Daisuke Nishimura483c30b2010-03-10 15:22:18 -08004821 VM_BUG_ON(mc.moved_swap);
KAMEZAWA Hiroyuki32047e22010-10-27 15:33:40 -07004822 mem_cgroup_start_move(from);
KAMEZAWA Hiroyuki2bd9bb22010-08-10 18:02:58 -07004823 spin_lock(&mc.lock);
Daisuke Nishimura4ffef5f2010-03-10 15:22:14 -08004824 mc.from = from;
4825 mc.to = mem;
KAMEZAWA Hiroyuki2bd9bb22010-08-10 18:02:58 -07004826 spin_unlock(&mc.lock);
Daisuke Nishimuradfe076b2011-01-13 15:47:41 -08004827 /* We set mc.moving_task later */
Daisuke Nishimura7dc74be2010-03-10 15:22:13 -08004828
Daisuke Nishimura4ffef5f2010-03-10 15:22:14 -08004829 ret = mem_cgroup_precharge_mc(mm);
4830 if (ret)
4831 mem_cgroup_clear_mc();
Daisuke Nishimuradfe076b2011-01-13 15:47:41 -08004832 }
4833 mmput(mm);
Daisuke Nishimura7dc74be2010-03-10 15:22:13 -08004834 }
4835 return ret;
4836}
4837
4838static void mem_cgroup_cancel_attach(struct cgroup_subsys *ss,
4839 struct cgroup *cgroup,
4840 struct task_struct *p,
4841 bool threadgroup)
4842{
Daisuke Nishimura4ffef5f2010-03-10 15:22:14 -08004843 mem_cgroup_clear_mc();
Daisuke Nishimura7dc74be2010-03-10 15:22:13 -08004844}
4845
Daisuke Nishimura4ffef5f2010-03-10 15:22:14 -08004846static int mem_cgroup_move_charge_pte_range(pmd_t *pmd,
4847 unsigned long addr, unsigned long end,
4848 struct mm_walk *walk)
Daisuke Nishimura7dc74be2010-03-10 15:22:13 -08004849{
Daisuke Nishimura4ffef5f2010-03-10 15:22:14 -08004850 int ret = 0;
4851 struct vm_area_struct *vma = walk->private;
4852 pte_t *pte;
4853 spinlock_t *ptl;
4854
4855retry:
Andrea Arcangeliec168512011-01-13 15:46:56 -08004856 VM_BUG_ON(pmd_trans_huge(*pmd));
Daisuke Nishimura4ffef5f2010-03-10 15:22:14 -08004857 pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl);
4858 for (; addr != end; addr += PAGE_SIZE) {
4859 pte_t ptent = *(pte++);
4860 union mc_target target;
4861 int type;
4862 struct page *page;
4863 struct page_cgroup *pc;
Daisuke Nishimura02491442010-03-10 15:22:17 -08004864 swp_entry_t ent;
Daisuke Nishimura4ffef5f2010-03-10 15:22:14 -08004865
4866 if (!mc.precharge)
4867 break;
4868
4869 type = is_target_pte_for_mc(vma, addr, ptent, &target);
4870 switch (type) {
4871 case MC_TARGET_PAGE:
4872 page = target.page;
4873 if (isolate_lru_page(page))
4874 goto put;
4875 pc = lookup_page_cgroup(page);
Daisuke Nishimura854ffa82010-03-10 15:22:15 -08004876 if (!mem_cgroup_move_account(pc,
KAMEZAWA Hiroyuki987eba62011-01-20 14:44:25 -08004877 mc.from, mc.to, false, PAGE_SIZE)) {
Daisuke Nishimura4ffef5f2010-03-10 15:22:14 -08004878 mc.precharge--;
Daisuke Nishimura854ffa82010-03-10 15:22:15 -08004879 /* we uncharge from mc.from later. */
4880 mc.moved_charge++;
Daisuke Nishimura4ffef5f2010-03-10 15:22:14 -08004881 }
4882 putback_lru_page(page);
4883put: /* is_target_pte_for_mc() gets the page */
4884 put_page(page);
4885 break;
Daisuke Nishimura02491442010-03-10 15:22:17 -08004886 case MC_TARGET_SWAP:
4887 ent = target.ent;
Daisuke Nishimura483c30b2010-03-10 15:22:18 -08004888 if (!mem_cgroup_move_swap_account(ent,
4889 mc.from, mc.to, false)) {
Daisuke Nishimura02491442010-03-10 15:22:17 -08004890 mc.precharge--;
Daisuke Nishimura483c30b2010-03-10 15:22:18 -08004891 /* we fixup refcnts and charges later. */
4892 mc.moved_swap++;
4893 }
Daisuke Nishimura02491442010-03-10 15:22:17 -08004894 break;
Daisuke Nishimura4ffef5f2010-03-10 15:22:14 -08004895 default:
4896 break;
4897 }
4898 }
4899 pte_unmap_unlock(pte - 1, ptl);
4900 cond_resched();
4901
4902 if (addr != end) {
4903 /*
4904 * We have consumed all precharges we got in can_attach().
4905 * We try charge one by one, but don't do any additional
4906 * charges to mc.to if we have failed in charge once in attach()
4907 * phase.
4908 */
Daisuke Nishimura854ffa82010-03-10 15:22:15 -08004909 ret = mem_cgroup_do_precharge(1);
Daisuke Nishimura4ffef5f2010-03-10 15:22:14 -08004910 if (!ret)
4911 goto retry;
4912 }
4913
4914 return ret;
4915}
4916
4917static void mem_cgroup_move_charge(struct mm_struct *mm)
4918{
4919 struct vm_area_struct *vma;
4920
4921 lru_add_drain_all();
Daisuke Nishimuradfe076b2011-01-13 15:47:41 -08004922retry:
4923 if (unlikely(!down_read_trylock(&mm->mmap_sem))) {
4924 /*
4925 * Someone who are holding the mmap_sem might be waiting in
4926 * waitq. So we cancel all extra charges, wake up all waiters,
4927 * and retry. Because we cancel precharges, we might not be able
4928 * to move enough charges, but moving charge is a best-effort
4929 * feature anyway, so it wouldn't be a big problem.
4930 */
4931 __mem_cgroup_clear_mc();
4932 cond_resched();
4933 goto retry;
4934 }
Daisuke Nishimura4ffef5f2010-03-10 15:22:14 -08004935 for (vma = mm->mmap; vma; vma = vma->vm_next) {
4936 int ret;
4937 struct mm_walk mem_cgroup_move_charge_walk = {
4938 .pmd_entry = mem_cgroup_move_charge_pte_range,
4939 .mm = mm,
4940 .private = vma,
4941 };
4942 if (is_vm_hugetlb_page(vma))
4943 continue;
Daisuke Nishimura4ffef5f2010-03-10 15:22:14 -08004944 ret = walk_page_range(vma->vm_start, vma->vm_end,
4945 &mem_cgroup_move_charge_walk);
4946 if (ret)
4947 /*
4948 * means we have consumed all precharges and failed in
4949 * doing additional charge. Just abandon here.
4950 */
4951 break;
4952 }
Daisuke Nishimuradfe076b2011-01-13 15:47:41 -08004953 up_read(&mm->mmap_sem);
Daisuke Nishimura7dc74be2010-03-10 15:22:13 -08004954}
4955
Balbir Singh67e465a2008-02-07 00:13:54 -08004956static void mem_cgroup_move_task(struct cgroup_subsys *ss,
4957 struct cgroup *cont,
4958 struct cgroup *old_cont,
Ben Blumbe367d02009-09-23 15:56:31 -07004959 struct task_struct *p,
4960 bool threadgroup)
Balbir Singh67e465a2008-02-07 00:13:54 -08004961{
Daisuke Nishimuradfe076b2011-01-13 15:47:41 -08004962 struct mm_struct *mm;
4963
4964 if (!mc.to)
Daisuke Nishimura4ffef5f2010-03-10 15:22:14 -08004965 /* no need to move charge */
4966 return;
4967
Daisuke Nishimuradfe076b2011-01-13 15:47:41 -08004968 mm = get_task_mm(p);
4969 if (mm) {
4970 mem_cgroup_move_charge(mm);
4971 mmput(mm);
4972 }
Daisuke Nishimura4ffef5f2010-03-10 15:22:14 -08004973 mem_cgroup_clear_mc();
Balbir Singh67e465a2008-02-07 00:13:54 -08004974}
Daisuke Nishimura5cfb80a2010-03-23 13:35:11 -07004975#else /* !CONFIG_MMU */
4976static int mem_cgroup_can_attach(struct cgroup_subsys *ss,
4977 struct cgroup *cgroup,
4978 struct task_struct *p,
4979 bool threadgroup)
4980{
4981 return 0;
4982}
4983static void mem_cgroup_cancel_attach(struct cgroup_subsys *ss,
4984 struct cgroup *cgroup,
4985 struct task_struct *p,
4986 bool threadgroup)
4987{
4988}
4989static void mem_cgroup_move_task(struct cgroup_subsys *ss,
4990 struct cgroup *cont,
4991 struct cgroup *old_cont,
4992 struct task_struct *p,
4993 bool threadgroup)
4994{
4995}
4996#endif
Balbir Singh67e465a2008-02-07 00:13:54 -08004997
Balbir Singh8cdea7c2008-02-07 00:13:50 -08004998struct cgroup_subsys mem_cgroup_subsys = {
4999 .name = "memory",
5000 .subsys_id = mem_cgroup_subsys_id,
5001 .create = mem_cgroup_create,
KAMEZAWA Hiroyukidf878fb2008-02-07 00:14:28 -08005002 .pre_destroy = mem_cgroup_pre_destroy,
Balbir Singh8cdea7c2008-02-07 00:13:50 -08005003 .destroy = mem_cgroup_destroy,
5004 .populate = mem_cgroup_populate,
Daisuke Nishimura7dc74be2010-03-10 15:22:13 -08005005 .can_attach = mem_cgroup_can_attach,
5006 .cancel_attach = mem_cgroup_cancel_attach,
Balbir Singh67e465a2008-02-07 00:13:54 -08005007 .attach = mem_cgroup_move_task,
KAMEZAWA Hiroyuki6d12e2d2008-02-07 00:14:31 -08005008 .early_init = 0,
KAMEZAWA Hiroyuki04046e12009-04-02 16:57:33 -07005009 .use_id = 1,
Balbir Singh8cdea7c2008-02-07 00:13:50 -08005010};
KAMEZAWA Hiroyukic0777192009-01-07 18:07:57 -08005011
5012#ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP
Michal Hockoa42c3902010-11-24 12:57:08 -08005013static int __init enable_swap_account(char *s)
5014{
5015 /* consider enabled if no parameter or 1 is given */
5016 if (!s || !strcmp(s, "1"))
5017 really_do_swap_account = 1;
5018 else if (!strcmp(s, "0"))
5019 really_do_swap_account = 0;
5020 return 1;
5021}
5022__setup("swapaccount", enable_swap_account);
KAMEZAWA Hiroyukic0777192009-01-07 18:07:57 -08005023
5024static int __init disable_swap_account(char *s)
5025{
Michal Hockoa42c3902010-11-24 12:57:08 -08005026 enable_swap_account("0");
KAMEZAWA Hiroyukic0777192009-01-07 18:07:57 -08005027 return 1;
5028}
5029__setup("noswapaccount", disable_swap_account);
5030#endif