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8cdea7c0 BS |
1 | /* memcontrol.c - Memory Controller |
2 | * | |
3 | * Copyright IBM Corporation, 2007 | |
4 | * Author Balbir Singh <balbir@linux.vnet.ibm.com> | |
5 | * | |
78fb7466 PE |
6 | * Copyright 2007 OpenVZ SWsoft Inc |
7 | * Author: Pavel Emelianov <xemul@openvz.org> | |
8 | * | |
2e72b634 KS |
9 | * Memory thresholds |
10 | * Copyright (C) 2009 Nokia Corporation | |
11 | * Author: Kirill A. Shutemov | |
12 | * | |
8cdea7c0 BS |
13 | * 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> | |
78fb7466 | 27 | #include <linux/mm.h> |
4ffef5fe | 28 | #include <linux/hugetlb.h> |
d13d1443 | 29 | #include <linux/pagemap.h> |
d52aa412 | 30 | #include <linux/smp.h> |
8a9f3ccd | 31 | #include <linux/page-flags.h> |
66e1707b | 32 | #include <linux/backing-dev.h> |
8a9f3ccd BS |
33 | #include <linux/bit_spinlock.h> |
34 | #include <linux/rcupdate.h> | |
e222432b | 35 | #include <linux/limits.h> |
b9e15baf | 36 | #include <linux/export.h> |
8c7c6e34 | 37 | #include <linux/mutex.h> |
f64c3f54 | 38 | #include <linux/rbtree.h> |
b6ac57d5 | 39 | #include <linux/slab.h> |
66e1707b | 40 | #include <linux/swap.h> |
02491447 | 41 | #include <linux/swapops.h> |
66e1707b | 42 | #include <linux/spinlock.h> |
2e72b634 KS |
43 | #include <linux/eventfd.h> |
44 | #include <linux/sort.h> | |
66e1707b | 45 | #include <linux/fs.h> |
d2ceb9b7 | 46 | #include <linux/seq_file.h> |
33327948 | 47 | #include <linux/vmalloc.h> |
b69408e8 | 48 | #include <linux/mm_inline.h> |
52d4b9ac | 49 | #include <linux/page_cgroup.h> |
cdec2e42 | 50 | #include <linux/cpu.h> |
158e0a2d | 51 | #include <linux/oom.h> |
08e552c6 | 52 | #include "internal.h" |
d1a4c0b3 GC |
53 | #include <net/sock.h> |
54 | #include <net/tcp_memcontrol.h> | |
8cdea7c0 | 55 | |
8697d331 BS |
56 | #include <asm/uaccess.h> |
57 | ||
cc8e970c KM |
58 | #include <trace/events/vmscan.h> |
59 | ||
a181b0e8 | 60 | struct cgroup_subsys mem_cgroup_subsys __read_mostly; |
a181b0e8 | 61 | #define MEM_CGROUP_RECLAIM_RETRIES 5 |
6bbda35c | 62 | static struct mem_cgroup *root_mem_cgroup __read_mostly; |
8cdea7c0 | 63 | |
c077719b | 64 | #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP |
338c8431 | 65 | /* Turned on only when memory cgroup is enabled && really_do_swap_account = 1 */ |
c077719b | 66 | int do_swap_account __read_mostly; |
a42c390c MH |
67 | |
68 | /* for remember boot option*/ | |
69 | #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP_ENABLED | |
70 | static int really_do_swap_account __initdata = 1; | |
71 | #else | |
72 | static int really_do_swap_account __initdata = 0; | |
73 | #endif | |
74 | ||
c077719b | 75 | #else |
a0db00fc | 76 | #define do_swap_account 0 |
c077719b KH |
77 | #endif |
78 | ||
79 | ||
d52aa412 KH |
80 | /* |
81 | * Statistics for memory cgroup. | |
82 | */ | |
83 | enum mem_cgroup_stat_index { | |
84 | /* | |
85 | * For MEM_CONTAINER_TYPE_ALL, usage = pagecache + rss. | |
86 | */ | |
87 | MEM_CGROUP_STAT_CACHE, /* # of pages charged as cache */ | |
d69b042f | 88 | MEM_CGROUP_STAT_RSS, /* # of pages charged as anon rss */ |
d8046582 | 89 | MEM_CGROUP_STAT_FILE_MAPPED, /* # of pages charged as file rss */ |
0c3e73e8 | 90 | MEM_CGROUP_STAT_SWAPOUT, /* # of pages, swapped out */ |
d52aa412 KH |
91 | MEM_CGROUP_STAT_NSTATS, |
92 | }; | |
93 | ||
af7c4b0e JW |
94 | static const char * const mem_cgroup_stat_names[] = { |
95 | "cache", | |
96 | "rss", | |
97 | "mapped_file", | |
98 | "swap", | |
99 | }; | |
100 | ||
e9f8974f JW |
101 | enum mem_cgroup_events_index { |
102 | MEM_CGROUP_EVENTS_PGPGIN, /* # of pages paged in */ | |
103 | MEM_CGROUP_EVENTS_PGPGOUT, /* # of pages paged out */ | |
456f998e YH |
104 | MEM_CGROUP_EVENTS_PGFAULT, /* # of page-faults */ |
105 | MEM_CGROUP_EVENTS_PGMAJFAULT, /* # of major page-faults */ | |
e9f8974f JW |
106 | MEM_CGROUP_EVENTS_NSTATS, |
107 | }; | |
af7c4b0e JW |
108 | |
109 | static const char * const mem_cgroup_events_names[] = { | |
110 | "pgpgin", | |
111 | "pgpgout", | |
112 | "pgfault", | |
113 | "pgmajfault", | |
114 | }; | |
115 | ||
7a159cc9 JW |
116 | /* |
117 | * Per memcg event counter is incremented at every pagein/pageout. With THP, | |
118 | * it will be incremated by the number of pages. This counter is used for | |
119 | * for trigger some periodic events. This is straightforward and better | |
120 | * than using jiffies etc. to handle periodic memcg event. | |
121 | */ | |
122 | enum mem_cgroup_events_target { | |
123 | MEM_CGROUP_TARGET_THRESH, | |
124 | MEM_CGROUP_TARGET_SOFTLIMIT, | |
453a9bf3 | 125 | MEM_CGROUP_TARGET_NUMAINFO, |
7a159cc9 JW |
126 | MEM_CGROUP_NTARGETS, |
127 | }; | |
a0db00fc KS |
128 | #define THRESHOLDS_EVENTS_TARGET 128 |
129 | #define SOFTLIMIT_EVENTS_TARGET 1024 | |
130 | #define NUMAINFO_EVENTS_TARGET 1024 | |
e9f8974f | 131 | |
d52aa412 | 132 | struct mem_cgroup_stat_cpu { |
7a159cc9 | 133 | long count[MEM_CGROUP_STAT_NSTATS]; |
e9f8974f | 134 | unsigned long events[MEM_CGROUP_EVENTS_NSTATS]; |
13114716 | 135 | unsigned long nr_page_events; |
7a159cc9 | 136 | unsigned long targets[MEM_CGROUP_NTARGETS]; |
d52aa412 KH |
137 | }; |
138 | ||
527a5ec9 JW |
139 | struct mem_cgroup_reclaim_iter { |
140 | /* css_id of the last scanned hierarchy member */ | |
141 | int position; | |
142 | /* scan generation, increased every round-trip */ | |
143 | unsigned int generation; | |
144 | }; | |
145 | ||
6d12e2d8 KH |
146 | /* |
147 | * per-zone information in memory controller. | |
148 | */ | |
6d12e2d8 | 149 | struct mem_cgroup_per_zone { |
6290df54 | 150 | struct lruvec lruvec; |
1eb49272 | 151 | unsigned long lru_size[NR_LRU_LISTS]; |
3e2f41f1 | 152 | |
527a5ec9 JW |
153 | struct mem_cgroup_reclaim_iter reclaim_iter[DEF_PRIORITY + 1]; |
154 | ||
f64c3f54 BS |
155 | struct rb_node tree_node; /* RB tree node */ |
156 | unsigned long long usage_in_excess;/* Set to the value by which */ | |
157 | /* the soft limit is exceeded*/ | |
158 | bool on_tree; | |
d79154bb | 159 | struct mem_cgroup *memcg; /* Back pointer, we cannot */ |
4e416953 | 160 | /* use container_of */ |
6d12e2d8 | 161 | }; |
6d12e2d8 KH |
162 | |
163 | struct mem_cgroup_per_node { | |
164 | struct mem_cgroup_per_zone zoneinfo[MAX_NR_ZONES]; | |
165 | }; | |
166 | ||
167 | struct mem_cgroup_lru_info { | |
168 | struct mem_cgroup_per_node *nodeinfo[MAX_NUMNODES]; | |
169 | }; | |
170 | ||
f64c3f54 BS |
171 | /* |
172 | * Cgroups above their limits are maintained in a RB-Tree, independent of | |
173 | * their hierarchy representation | |
174 | */ | |
175 | ||
176 | struct mem_cgroup_tree_per_zone { | |
177 | struct rb_root rb_root; | |
178 | spinlock_t lock; | |
179 | }; | |
180 | ||
181 | struct mem_cgroup_tree_per_node { | |
182 | struct mem_cgroup_tree_per_zone rb_tree_per_zone[MAX_NR_ZONES]; | |
183 | }; | |
184 | ||
185 | struct mem_cgroup_tree { | |
186 | struct mem_cgroup_tree_per_node *rb_tree_per_node[MAX_NUMNODES]; | |
187 | }; | |
188 | ||
189 | static struct mem_cgroup_tree soft_limit_tree __read_mostly; | |
190 | ||
2e72b634 KS |
191 | struct mem_cgroup_threshold { |
192 | struct eventfd_ctx *eventfd; | |
193 | u64 threshold; | |
194 | }; | |
195 | ||
9490ff27 | 196 | /* For threshold */ |
2e72b634 | 197 | struct mem_cgroup_threshold_ary { |
748dad36 | 198 | /* An array index points to threshold just below or equal to usage. */ |
5407a562 | 199 | int current_threshold; |
2e72b634 KS |
200 | /* Size of entries[] */ |
201 | unsigned int size; | |
202 | /* Array of thresholds */ | |
203 | struct mem_cgroup_threshold entries[0]; | |
204 | }; | |
2c488db2 KS |
205 | |
206 | struct mem_cgroup_thresholds { | |
207 | /* Primary thresholds array */ | |
208 | struct mem_cgroup_threshold_ary *primary; | |
209 | /* | |
210 | * Spare threshold array. | |
211 | * This is needed to make mem_cgroup_unregister_event() "never fail". | |
212 | * It must be able to store at least primary->size - 1 entries. | |
213 | */ | |
214 | struct mem_cgroup_threshold_ary *spare; | |
215 | }; | |
216 | ||
9490ff27 KH |
217 | /* for OOM */ |
218 | struct mem_cgroup_eventfd_list { | |
219 | struct list_head list; | |
220 | struct eventfd_ctx *eventfd; | |
221 | }; | |
2e72b634 | 222 | |
c0ff4b85 R |
223 | static void mem_cgroup_threshold(struct mem_cgroup *memcg); |
224 | static void mem_cgroup_oom_notify(struct mem_cgroup *memcg); | |
2e72b634 | 225 | |
8cdea7c0 BS |
226 | /* |
227 | * The memory controller data structure. The memory controller controls both | |
228 | * page cache and RSS per cgroup. We would eventually like to provide | |
229 | * statistics based on the statistics developed by Rik Van Riel for clock-pro, | |
230 | * to help the administrator determine what knobs to tune. | |
231 | * | |
232 | * TODO: Add a water mark for the memory controller. Reclaim will begin when | |
8a9f3ccd BS |
233 | * we hit the water mark. May be even add a low water mark, such that |
234 | * no reclaim occurs from a cgroup at it's low water mark, this is | |
235 | * a feature that will be implemented much later in the future. | |
8cdea7c0 BS |
236 | */ |
237 | struct mem_cgroup { | |
238 | struct cgroup_subsys_state css; | |
239 | /* | |
240 | * the counter to account for memory usage | |
241 | */ | |
242 | struct res_counter res; | |
59927fb9 HD |
243 | |
244 | union { | |
245 | /* | |
246 | * the counter to account for mem+swap usage. | |
247 | */ | |
248 | struct res_counter memsw; | |
249 | ||
250 | /* | |
251 | * rcu_freeing is used only when freeing struct mem_cgroup, | |
252 | * so put it into a union to avoid wasting more memory. | |
253 | * It must be disjoint from the css field. It could be | |
254 | * in a union with the res field, but res plays a much | |
255 | * larger part in mem_cgroup life than memsw, and might | |
256 | * be of interest, even at time of free, when debugging. | |
257 | * So share rcu_head with the less interesting memsw. | |
258 | */ | |
259 | struct rcu_head rcu_freeing; | |
260 | /* | |
3afe36b1 GC |
261 | * We also need some space for a worker in deferred freeing. |
262 | * By the time we call it, rcu_freeing is no longer in use. | |
59927fb9 HD |
263 | */ |
264 | struct work_struct work_freeing; | |
265 | }; | |
266 | ||
78fb7466 PE |
267 | /* |
268 | * Per cgroup active and inactive list, similar to the | |
269 | * per zone LRU lists. | |
78fb7466 | 270 | */ |
6d12e2d8 | 271 | struct mem_cgroup_lru_info info; |
889976db YH |
272 | int last_scanned_node; |
273 | #if MAX_NUMNODES > 1 | |
274 | nodemask_t scan_nodes; | |
453a9bf3 KH |
275 | atomic_t numainfo_events; |
276 | atomic_t numainfo_updating; | |
889976db | 277 | #endif |
18f59ea7 BS |
278 | /* |
279 | * Should the accounting and control be hierarchical, per subtree? | |
280 | */ | |
281 | bool use_hierarchy; | |
79dfdacc MH |
282 | |
283 | bool oom_lock; | |
284 | atomic_t under_oom; | |
285 | ||
8c7c6e34 | 286 | atomic_t refcnt; |
14797e23 | 287 | |
1f4c025b | 288 | int swappiness; |
3c11ecf4 KH |
289 | /* OOM-Killer disable */ |
290 | int oom_kill_disable; | |
a7885eb8 | 291 | |
22a668d7 KH |
292 | /* set when res.limit == memsw.limit */ |
293 | bool memsw_is_minimum; | |
294 | ||
2e72b634 KS |
295 | /* protect arrays of thresholds */ |
296 | struct mutex thresholds_lock; | |
297 | ||
298 | /* thresholds for memory usage. RCU-protected */ | |
2c488db2 | 299 | struct mem_cgroup_thresholds thresholds; |
907860ed | 300 | |
2e72b634 | 301 | /* thresholds for mem+swap usage. RCU-protected */ |
2c488db2 | 302 | struct mem_cgroup_thresholds memsw_thresholds; |
907860ed | 303 | |
9490ff27 KH |
304 | /* For oom notifier event fd */ |
305 | struct list_head oom_notify; | |
185efc0f | 306 | |
7dc74be0 DN |
307 | /* |
308 | * Should we move charges of a task when a task is moved into this | |
309 | * mem_cgroup ? And what type of charges should we move ? | |
310 | */ | |
311 | unsigned long move_charge_at_immigrate; | |
619d094b KH |
312 | /* |
313 | * set > 0 if pages under this cgroup are moving to other cgroup. | |
314 | */ | |
315 | atomic_t moving_account; | |
312734c0 KH |
316 | /* taken only while moving_account > 0 */ |
317 | spinlock_t move_lock; | |
d52aa412 | 318 | /* |
c62b1a3b | 319 | * percpu counter. |
d52aa412 | 320 | */ |
3a7951b4 | 321 | struct mem_cgroup_stat_cpu __percpu *stat; |
711d3d2c KH |
322 | /* |
323 | * used when a cpu is offlined or other synchronizations | |
324 | * See mem_cgroup_read_stat(). | |
325 | */ | |
326 | struct mem_cgroup_stat_cpu nocpu_base; | |
327 | spinlock_t pcp_counter_lock; | |
d1a4c0b3 GC |
328 | |
329 | #ifdef CONFIG_INET | |
330 | struct tcp_memcontrol tcp_mem; | |
331 | #endif | |
8cdea7c0 BS |
332 | }; |
333 | ||
7dc74be0 DN |
334 | /* Stuffs for move charges at task migration. */ |
335 | /* | |
336 | * Types of charges to be moved. "move_charge_at_immitgrate" is treated as a | |
337 | * left-shifted bitmap of these types. | |
338 | */ | |
339 | enum move_type { | |
4ffef5fe | 340 | MOVE_CHARGE_TYPE_ANON, /* private anonymous page and swap of it */ |
87946a72 | 341 | MOVE_CHARGE_TYPE_FILE, /* file page(including tmpfs) and swap of it */ |
7dc74be0 DN |
342 | NR_MOVE_TYPE, |
343 | }; | |
344 | ||
4ffef5fe DN |
345 | /* "mc" and its members are protected by cgroup_mutex */ |
346 | static struct move_charge_struct { | |
b1dd693e | 347 | spinlock_t lock; /* for from, to */ |
4ffef5fe DN |
348 | struct mem_cgroup *from; |
349 | struct mem_cgroup *to; | |
350 | unsigned long precharge; | |
854ffa8d | 351 | unsigned long moved_charge; |
483c30b5 | 352 | unsigned long moved_swap; |
8033b97c DN |
353 | struct task_struct *moving_task; /* a task moving charges */ |
354 | wait_queue_head_t waitq; /* a waitq for other context */ | |
355 | } mc = { | |
2bd9bb20 | 356 | .lock = __SPIN_LOCK_UNLOCKED(mc.lock), |
8033b97c DN |
357 | .waitq = __WAIT_QUEUE_HEAD_INITIALIZER(mc.waitq), |
358 | }; | |
4ffef5fe | 359 | |
90254a65 DN |
360 | static bool move_anon(void) |
361 | { | |
362 | return test_bit(MOVE_CHARGE_TYPE_ANON, | |
363 | &mc.to->move_charge_at_immigrate); | |
364 | } | |
365 | ||
87946a72 DN |
366 | static bool move_file(void) |
367 | { | |
368 | return test_bit(MOVE_CHARGE_TYPE_FILE, | |
369 | &mc.to->move_charge_at_immigrate); | |
370 | } | |
371 | ||
4e416953 BS |
372 | /* |
373 | * Maximum loops in mem_cgroup_hierarchical_reclaim(), used for soft | |
374 | * limit reclaim to prevent infinite loops, if they ever occur. | |
375 | */ | |
a0db00fc KS |
376 | #define MEM_CGROUP_MAX_RECLAIM_LOOPS 100 |
377 | #define MEM_CGROUP_MAX_SOFT_LIMIT_RECLAIM_LOOPS 2 | |
4e416953 | 378 | |
217bc319 KH |
379 | enum charge_type { |
380 | MEM_CGROUP_CHARGE_TYPE_CACHE = 0, | |
381 | MEM_CGROUP_CHARGE_TYPE_MAPPED, | |
4f98a2fe | 382 | MEM_CGROUP_CHARGE_TYPE_SHMEM, /* used by page migration of shmem */ |
c05555b5 | 383 | MEM_CGROUP_CHARGE_TYPE_FORCE, /* used by force_empty */ |
d13d1443 | 384 | MEM_CGROUP_CHARGE_TYPE_SWAPOUT, /* for accounting swapcache */ |
8a9478ca | 385 | MEM_CGROUP_CHARGE_TYPE_DROP, /* a page was unused swap cache */ |
c05555b5 KH |
386 | NR_CHARGE_TYPE, |
387 | }; | |
388 | ||
8c7c6e34 | 389 | /* for encoding cft->private value on file */ |
65c64ce8 GC |
390 | #define _MEM (0) |
391 | #define _MEMSWAP (1) | |
392 | #define _OOM_TYPE (2) | |
a0db00fc KS |
393 | #define MEMFILE_PRIVATE(x, val) ((x) << 16 | (val)) |
394 | #define MEMFILE_TYPE(val) ((val) >> 16 & 0xffff) | |
8c7c6e34 | 395 | #define MEMFILE_ATTR(val) ((val) & 0xffff) |
9490ff27 KH |
396 | /* Used for OOM nofiier */ |
397 | #define OOM_CONTROL (0) | |
8c7c6e34 | 398 | |
75822b44 BS |
399 | /* |
400 | * Reclaim flags for mem_cgroup_hierarchical_reclaim | |
401 | */ | |
402 | #define MEM_CGROUP_RECLAIM_NOSWAP_BIT 0x0 | |
403 | #define MEM_CGROUP_RECLAIM_NOSWAP (1 << MEM_CGROUP_RECLAIM_NOSWAP_BIT) | |
404 | #define MEM_CGROUP_RECLAIM_SHRINK_BIT 0x1 | |
405 | #define MEM_CGROUP_RECLAIM_SHRINK (1 << MEM_CGROUP_RECLAIM_SHRINK_BIT) | |
406 | ||
c0ff4b85 R |
407 | static void mem_cgroup_get(struct mem_cgroup *memcg); |
408 | static void mem_cgroup_put(struct mem_cgroup *memcg); | |
e1aab161 GC |
409 | |
410 | /* Writing them here to avoid exposing memcg's inner layout */ | |
411 | #ifdef CONFIG_CGROUP_MEM_RES_CTLR_KMEM | |
e1aab161 | 412 | #include <net/sock.h> |
d1a4c0b3 | 413 | #include <net/ip.h> |
e1aab161 GC |
414 | |
415 | static bool mem_cgroup_is_root(struct mem_cgroup *memcg); | |
416 | void sock_update_memcg(struct sock *sk) | |
417 | { | |
376be5ff | 418 | if (mem_cgroup_sockets_enabled) { |
e1aab161 GC |
419 | struct mem_cgroup *memcg; |
420 | ||
421 | BUG_ON(!sk->sk_prot->proto_cgroup); | |
422 | ||
f3f511e1 GC |
423 | /* Socket cloning can throw us here with sk_cgrp already |
424 | * filled. It won't however, necessarily happen from | |
425 | * process context. So the test for root memcg given | |
426 | * the current task's memcg won't help us in this case. | |
427 | * | |
428 | * Respecting the original socket's memcg is a better | |
429 | * decision in this case. | |
430 | */ | |
431 | if (sk->sk_cgrp) { | |
432 | BUG_ON(mem_cgroup_is_root(sk->sk_cgrp->memcg)); | |
433 | mem_cgroup_get(sk->sk_cgrp->memcg); | |
434 | return; | |
435 | } | |
436 | ||
e1aab161 GC |
437 | rcu_read_lock(); |
438 | memcg = mem_cgroup_from_task(current); | |
439 | if (!mem_cgroup_is_root(memcg)) { | |
440 | mem_cgroup_get(memcg); | |
441 | sk->sk_cgrp = sk->sk_prot->proto_cgroup(memcg); | |
442 | } | |
443 | rcu_read_unlock(); | |
444 | } | |
445 | } | |
446 | EXPORT_SYMBOL(sock_update_memcg); | |
447 | ||
448 | void sock_release_memcg(struct sock *sk) | |
449 | { | |
376be5ff | 450 | if (mem_cgroup_sockets_enabled && sk->sk_cgrp) { |
e1aab161 GC |
451 | struct mem_cgroup *memcg; |
452 | WARN_ON(!sk->sk_cgrp->memcg); | |
453 | memcg = sk->sk_cgrp->memcg; | |
454 | mem_cgroup_put(memcg); | |
455 | } | |
456 | } | |
d1a4c0b3 | 457 | |
319d3b9c | 458 | #ifdef CONFIG_INET |
d1a4c0b3 GC |
459 | struct cg_proto *tcp_proto_cgroup(struct mem_cgroup *memcg) |
460 | { | |
461 | if (!memcg || mem_cgroup_is_root(memcg)) | |
462 | return NULL; | |
463 | ||
464 | return &memcg->tcp_mem.cg_proto; | |
465 | } | |
466 | EXPORT_SYMBOL(tcp_proto_cgroup); | |
e1aab161 GC |
467 | #endif /* CONFIG_INET */ |
468 | #endif /* CONFIG_CGROUP_MEM_RES_CTLR_KMEM */ | |
469 | ||
c0ff4b85 | 470 | static void drain_all_stock_async(struct mem_cgroup *memcg); |
8c7c6e34 | 471 | |
f64c3f54 | 472 | static struct mem_cgroup_per_zone * |
c0ff4b85 | 473 | mem_cgroup_zoneinfo(struct mem_cgroup *memcg, int nid, int zid) |
f64c3f54 | 474 | { |
c0ff4b85 | 475 | return &memcg->info.nodeinfo[nid]->zoneinfo[zid]; |
f64c3f54 BS |
476 | } |
477 | ||
c0ff4b85 | 478 | struct cgroup_subsys_state *mem_cgroup_css(struct mem_cgroup *memcg) |
d324236b | 479 | { |
c0ff4b85 | 480 | return &memcg->css; |
d324236b WF |
481 | } |
482 | ||
f64c3f54 | 483 | static struct mem_cgroup_per_zone * |
c0ff4b85 | 484 | page_cgroup_zoneinfo(struct mem_cgroup *memcg, struct page *page) |
f64c3f54 | 485 | { |
97a6c37b JW |
486 | int nid = page_to_nid(page); |
487 | int zid = page_zonenum(page); | |
f64c3f54 | 488 | |
c0ff4b85 | 489 | return mem_cgroup_zoneinfo(memcg, nid, zid); |
f64c3f54 BS |
490 | } |
491 | ||
492 | static struct mem_cgroup_tree_per_zone * | |
493 | soft_limit_tree_node_zone(int nid, int zid) | |
494 | { | |
495 | return &soft_limit_tree.rb_tree_per_node[nid]->rb_tree_per_zone[zid]; | |
496 | } | |
497 | ||
498 | static struct mem_cgroup_tree_per_zone * | |
499 | soft_limit_tree_from_page(struct page *page) | |
500 | { | |
501 | int nid = page_to_nid(page); | |
502 | int zid = page_zonenum(page); | |
503 | ||
504 | return &soft_limit_tree.rb_tree_per_node[nid]->rb_tree_per_zone[zid]; | |
505 | } | |
506 | ||
507 | static void | |
c0ff4b85 | 508 | __mem_cgroup_insert_exceeded(struct mem_cgroup *memcg, |
f64c3f54 | 509 | struct mem_cgroup_per_zone *mz, |
ef8745c1 KH |
510 | struct mem_cgroup_tree_per_zone *mctz, |
511 | unsigned long long new_usage_in_excess) | |
f64c3f54 BS |
512 | { |
513 | struct rb_node **p = &mctz->rb_root.rb_node; | |
514 | struct rb_node *parent = NULL; | |
515 | struct mem_cgroup_per_zone *mz_node; | |
516 | ||
517 | if (mz->on_tree) | |
518 | return; | |
519 | ||
ef8745c1 KH |
520 | mz->usage_in_excess = new_usage_in_excess; |
521 | if (!mz->usage_in_excess) | |
522 | return; | |
f64c3f54 BS |
523 | while (*p) { |
524 | parent = *p; | |
525 | mz_node = rb_entry(parent, struct mem_cgroup_per_zone, | |
526 | tree_node); | |
527 | if (mz->usage_in_excess < mz_node->usage_in_excess) | |
528 | p = &(*p)->rb_left; | |
529 | /* | |
530 | * We can't avoid mem cgroups that are over their soft | |
531 | * limit by the same amount | |
532 | */ | |
533 | else if (mz->usage_in_excess >= mz_node->usage_in_excess) | |
534 | p = &(*p)->rb_right; | |
535 | } | |
536 | rb_link_node(&mz->tree_node, parent, p); | |
537 | rb_insert_color(&mz->tree_node, &mctz->rb_root); | |
538 | mz->on_tree = true; | |
4e416953 BS |
539 | } |
540 | ||
541 | static void | |
c0ff4b85 | 542 | __mem_cgroup_remove_exceeded(struct mem_cgroup *memcg, |
4e416953 BS |
543 | struct mem_cgroup_per_zone *mz, |
544 | struct mem_cgroup_tree_per_zone *mctz) | |
545 | { | |
546 | if (!mz->on_tree) | |
547 | return; | |
548 | rb_erase(&mz->tree_node, &mctz->rb_root); | |
549 | mz->on_tree = false; | |
550 | } | |
551 | ||
f64c3f54 | 552 | static void |
c0ff4b85 | 553 | mem_cgroup_remove_exceeded(struct mem_cgroup *memcg, |
f64c3f54 BS |
554 | struct mem_cgroup_per_zone *mz, |
555 | struct mem_cgroup_tree_per_zone *mctz) | |
556 | { | |
557 | spin_lock(&mctz->lock); | |
c0ff4b85 | 558 | __mem_cgroup_remove_exceeded(memcg, mz, mctz); |
f64c3f54 BS |
559 | spin_unlock(&mctz->lock); |
560 | } | |
561 | ||
f64c3f54 | 562 | |
c0ff4b85 | 563 | static void mem_cgroup_update_tree(struct mem_cgroup *memcg, struct page *page) |
f64c3f54 | 564 | { |
ef8745c1 | 565 | unsigned long long excess; |
f64c3f54 BS |
566 | struct mem_cgroup_per_zone *mz; |
567 | struct mem_cgroup_tree_per_zone *mctz; | |
4e649152 KH |
568 | int nid = page_to_nid(page); |
569 | int zid = page_zonenum(page); | |
f64c3f54 BS |
570 | mctz = soft_limit_tree_from_page(page); |
571 | ||
572 | /* | |
4e649152 KH |
573 | * Necessary to update all ancestors when hierarchy is used. |
574 | * because their event counter is not touched. | |
f64c3f54 | 575 | */ |
c0ff4b85 R |
576 | for (; memcg; memcg = parent_mem_cgroup(memcg)) { |
577 | mz = mem_cgroup_zoneinfo(memcg, nid, zid); | |
578 | excess = res_counter_soft_limit_excess(&memcg->res); | |
4e649152 KH |
579 | /* |
580 | * We have to update the tree if mz is on RB-tree or | |
581 | * mem is over its softlimit. | |
582 | */ | |
ef8745c1 | 583 | if (excess || mz->on_tree) { |
4e649152 KH |
584 | spin_lock(&mctz->lock); |
585 | /* if on-tree, remove it */ | |
586 | if (mz->on_tree) | |
c0ff4b85 | 587 | __mem_cgroup_remove_exceeded(memcg, mz, mctz); |
4e649152 | 588 | /* |
ef8745c1 KH |
589 | * Insert again. mz->usage_in_excess will be updated. |
590 | * If excess is 0, no tree ops. | |
4e649152 | 591 | */ |
c0ff4b85 | 592 | __mem_cgroup_insert_exceeded(memcg, mz, mctz, excess); |
4e649152 KH |
593 | spin_unlock(&mctz->lock); |
594 | } | |
f64c3f54 BS |
595 | } |
596 | } | |
597 | ||
c0ff4b85 | 598 | static void mem_cgroup_remove_from_trees(struct mem_cgroup *memcg) |
f64c3f54 BS |
599 | { |
600 | int node, zone; | |
601 | struct mem_cgroup_per_zone *mz; | |
602 | struct mem_cgroup_tree_per_zone *mctz; | |
603 | ||
3ed28fa1 | 604 | for_each_node(node) { |
f64c3f54 | 605 | for (zone = 0; zone < MAX_NR_ZONES; zone++) { |
c0ff4b85 | 606 | mz = mem_cgroup_zoneinfo(memcg, node, zone); |
f64c3f54 | 607 | mctz = soft_limit_tree_node_zone(node, zone); |
c0ff4b85 | 608 | mem_cgroup_remove_exceeded(memcg, mz, mctz); |
f64c3f54 BS |
609 | } |
610 | } | |
611 | } | |
612 | ||
4e416953 BS |
613 | static struct mem_cgroup_per_zone * |
614 | __mem_cgroup_largest_soft_limit_node(struct mem_cgroup_tree_per_zone *mctz) | |
615 | { | |
616 | struct rb_node *rightmost = NULL; | |
26251eaf | 617 | struct mem_cgroup_per_zone *mz; |
4e416953 BS |
618 | |
619 | retry: | |
26251eaf | 620 | mz = NULL; |
4e416953 BS |
621 | rightmost = rb_last(&mctz->rb_root); |
622 | if (!rightmost) | |
623 | goto done; /* Nothing to reclaim from */ | |
624 | ||
625 | mz = rb_entry(rightmost, struct mem_cgroup_per_zone, tree_node); | |
626 | /* | |
627 | * Remove the node now but someone else can add it back, | |
628 | * we will to add it back at the end of reclaim to its correct | |
629 | * position in the tree. | |
630 | */ | |
d79154bb HD |
631 | __mem_cgroup_remove_exceeded(mz->memcg, mz, mctz); |
632 | if (!res_counter_soft_limit_excess(&mz->memcg->res) || | |
633 | !css_tryget(&mz->memcg->css)) | |
4e416953 BS |
634 | goto retry; |
635 | done: | |
636 | return mz; | |
637 | } | |
638 | ||
639 | static struct mem_cgroup_per_zone * | |
640 | mem_cgroup_largest_soft_limit_node(struct mem_cgroup_tree_per_zone *mctz) | |
641 | { | |
642 | struct mem_cgroup_per_zone *mz; | |
643 | ||
644 | spin_lock(&mctz->lock); | |
645 | mz = __mem_cgroup_largest_soft_limit_node(mctz); | |
646 | spin_unlock(&mctz->lock); | |
647 | return mz; | |
648 | } | |
649 | ||
711d3d2c KH |
650 | /* |
651 | * Implementation Note: reading percpu statistics for memcg. | |
652 | * | |
653 | * Both of vmstat[] and percpu_counter has threshold and do periodic | |
654 | * synchronization to implement "quick" read. There are trade-off between | |
655 | * reading cost and precision of value. Then, we may have a chance to implement | |
656 | * a periodic synchronizion of counter in memcg's counter. | |
657 | * | |
658 | * But this _read() function is used for user interface now. The user accounts | |
659 | * memory usage by memory cgroup and he _always_ requires exact value because | |
660 | * he accounts memory. Even if we provide quick-and-fuzzy read, we always | |
661 | * have to visit all online cpus and make sum. So, for now, unnecessary | |
662 | * synchronization is not implemented. (just implemented for cpu hotplug) | |
663 | * | |
664 | * If there are kernel internal actions which can make use of some not-exact | |
665 | * value, and reading all cpu value can be performance bottleneck in some | |
666 | * common workload, threashold and synchonization as vmstat[] should be | |
667 | * implemented. | |
668 | */ | |
c0ff4b85 | 669 | static long mem_cgroup_read_stat(struct mem_cgroup *memcg, |
7a159cc9 | 670 | enum mem_cgroup_stat_index idx) |
c62b1a3b | 671 | { |
7a159cc9 | 672 | long val = 0; |
c62b1a3b | 673 | int cpu; |
c62b1a3b | 674 | |
711d3d2c KH |
675 | get_online_cpus(); |
676 | for_each_online_cpu(cpu) | |
c0ff4b85 | 677 | val += per_cpu(memcg->stat->count[idx], cpu); |
711d3d2c | 678 | #ifdef CONFIG_HOTPLUG_CPU |
c0ff4b85 R |
679 | spin_lock(&memcg->pcp_counter_lock); |
680 | val += memcg->nocpu_base.count[idx]; | |
681 | spin_unlock(&memcg->pcp_counter_lock); | |
711d3d2c KH |
682 | #endif |
683 | put_online_cpus(); | |
c62b1a3b KH |
684 | return val; |
685 | } | |
686 | ||
c0ff4b85 | 687 | static void mem_cgroup_swap_statistics(struct mem_cgroup *memcg, |
0c3e73e8 BS |
688 | bool charge) |
689 | { | |
690 | int val = (charge) ? 1 : -1; | |
c0ff4b85 | 691 | this_cpu_add(memcg->stat->count[MEM_CGROUP_STAT_SWAPOUT], val); |
0c3e73e8 BS |
692 | } |
693 | ||
c0ff4b85 | 694 | static unsigned long mem_cgroup_read_events(struct mem_cgroup *memcg, |
e9f8974f JW |
695 | enum mem_cgroup_events_index idx) |
696 | { | |
697 | unsigned long val = 0; | |
698 | int cpu; | |
699 | ||
700 | for_each_online_cpu(cpu) | |
c0ff4b85 | 701 | val += per_cpu(memcg->stat->events[idx], cpu); |
e9f8974f | 702 | #ifdef CONFIG_HOTPLUG_CPU |
c0ff4b85 R |
703 | spin_lock(&memcg->pcp_counter_lock); |
704 | val += memcg->nocpu_base.events[idx]; | |
705 | spin_unlock(&memcg->pcp_counter_lock); | |
e9f8974f JW |
706 | #endif |
707 | return val; | |
708 | } | |
709 | ||
c0ff4b85 | 710 | static void mem_cgroup_charge_statistics(struct mem_cgroup *memcg, |
b2402857 | 711 | bool anon, int nr_pages) |
d52aa412 | 712 | { |
c62b1a3b KH |
713 | preempt_disable(); |
714 | ||
b2402857 KH |
715 | /* |
716 | * Here, RSS means 'mapped anon' and anon's SwapCache. Shmem/tmpfs is | |
717 | * counted as CACHE even if it's on ANON LRU. | |
718 | */ | |
719 | if (anon) | |
720 | __this_cpu_add(memcg->stat->count[MEM_CGROUP_STAT_RSS], | |
c0ff4b85 | 721 | nr_pages); |
d52aa412 | 722 | else |
b2402857 | 723 | __this_cpu_add(memcg->stat->count[MEM_CGROUP_STAT_CACHE], |
c0ff4b85 | 724 | nr_pages); |
55e462b0 | 725 | |
e401f176 KH |
726 | /* pagein of a big page is an event. So, ignore page size */ |
727 | if (nr_pages > 0) | |
c0ff4b85 | 728 | __this_cpu_inc(memcg->stat->events[MEM_CGROUP_EVENTS_PGPGIN]); |
3751d604 | 729 | else { |
c0ff4b85 | 730 | __this_cpu_inc(memcg->stat->events[MEM_CGROUP_EVENTS_PGPGOUT]); |
3751d604 KH |
731 | nr_pages = -nr_pages; /* for event */ |
732 | } | |
e401f176 | 733 | |
13114716 | 734 | __this_cpu_add(memcg->stat->nr_page_events, nr_pages); |
2e72b634 | 735 | |
c62b1a3b | 736 | preempt_enable(); |
6d12e2d8 KH |
737 | } |
738 | ||
bb2a0de9 | 739 | unsigned long |
4d7dcca2 | 740 | mem_cgroup_get_lru_size(struct lruvec *lruvec, enum lru_list lru) |
074291fe KK |
741 | { |
742 | struct mem_cgroup_per_zone *mz; | |
743 | ||
744 | mz = container_of(lruvec, struct mem_cgroup_per_zone, lruvec); | |
745 | return mz->lru_size[lru]; | |
746 | } | |
747 | ||
748 | static unsigned long | |
c0ff4b85 | 749 | mem_cgroup_zone_nr_lru_pages(struct mem_cgroup *memcg, int nid, int zid, |
bb2a0de9 | 750 | unsigned int lru_mask) |
889976db YH |
751 | { |
752 | struct mem_cgroup_per_zone *mz; | |
f156ab93 | 753 | enum lru_list lru; |
bb2a0de9 KH |
754 | unsigned long ret = 0; |
755 | ||
c0ff4b85 | 756 | mz = mem_cgroup_zoneinfo(memcg, nid, zid); |
bb2a0de9 | 757 | |
f156ab93 HD |
758 | for_each_lru(lru) { |
759 | if (BIT(lru) & lru_mask) | |
760 | ret += mz->lru_size[lru]; | |
bb2a0de9 KH |
761 | } |
762 | return ret; | |
763 | } | |
764 | ||
765 | static unsigned long | |
c0ff4b85 | 766 | mem_cgroup_node_nr_lru_pages(struct mem_cgroup *memcg, |
bb2a0de9 KH |
767 | int nid, unsigned int lru_mask) |
768 | { | |
889976db YH |
769 | u64 total = 0; |
770 | int zid; | |
771 | ||
bb2a0de9 | 772 | for (zid = 0; zid < MAX_NR_ZONES; zid++) |
c0ff4b85 R |
773 | total += mem_cgroup_zone_nr_lru_pages(memcg, |
774 | nid, zid, lru_mask); | |
bb2a0de9 | 775 | |
889976db YH |
776 | return total; |
777 | } | |
bb2a0de9 | 778 | |
c0ff4b85 | 779 | static unsigned long mem_cgroup_nr_lru_pages(struct mem_cgroup *memcg, |
bb2a0de9 | 780 | unsigned int lru_mask) |
6d12e2d8 | 781 | { |
889976db | 782 | int nid; |
6d12e2d8 KH |
783 | u64 total = 0; |
784 | ||
bb2a0de9 | 785 | for_each_node_state(nid, N_HIGH_MEMORY) |
c0ff4b85 | 786 | total += mem_cgroup_node_nr_lru_pages(memcg, nid, lru_mask); |
6d12e2d8 | 787 | return total; |
d52aa412 KH |
788 | } |
789 | ||
f53d7ce3 JW |
790 | static bool mem_cgroup_event_ratelimit(struct mem_cgroup *memcg, |
791 | enum mem_cgroup_events_target target) | |
7a159cc9 JW |
792 | { |
793 | unsigned long val, next; | |
794 | ||
13114716 | 795 | val = __this_cpu_read(memcg->stat->nr_page_events); |
4799401f | 796 | next = __this_cpu_read(memcg->stat->targets[target]); |
7a159cc9 | 797 | /* from time_after() in jiffies.h */ |
f53d7ce3 JW |
798 | if ((long)next - (long)val < 0) { |
799 | switch (target) { | |
800 | case MEM_CGROUP_TARGET_THRESH: | |
801 | next = val + THRESHOLDS_EVENTS_TARGET; | |
802 | break; | |
803 | case MEM_CGROUP_TARGET_SOFTLIMIT: | |
804 | next = val + SOFTLIMIT_EVENTS_TARGET; | |
805 | break; | |
806 | case MEM_CGROUP_TARGET_NUMAINFO: | |
807 | next = val + NUMAINFO_EVENTS_TARGET; | |
808 | break; | |
809 | default: | |
810 | break; | |
811 | } | |
812 | __this_cpu_write(memcg->stat->targets[target], next); | |
813 | return true; | |
7a159cc9 | 814 | } |
f53d7ce3 | 815 | return false; |
d2265e6f KH |
816 | } |
817 | ||
818 | /* | |
819 | * Check events in order. | |
820 | * | |
821 | */ | |
c0ff4b85 | 822 | static void memcg_check_events(struct mem_cgroup *memcg, struct page *page) |
d2265e6f | 823 | { |
4799401f | 824 | preempt_disable(); |
d2265e6f | 825 | /* threshold event is triggered in finer grain than soft limit */ |
f53d7ce3 JW |
826 | if (unlikely(mem_cgroup_event_ratelimit(memcg, |
827 | MEM_CGROUP_TARGET_THRESH))) { | |
82b3f2a7 AM |
828 | bool do_softlimit; |
829 | bool do_numainfo __maybe_unused; | |
f53d7ce3 JW |
830 | |
831 | do_softlimit = mem_cgroup_event_ratelimit(memcg, | |
832 | MEM_CGROUP_TARGET_SOFTLIMIT); | |
833 | #if MAX_NUMNODES > 1 | |
834 | do_numainfo = mem_cgroup_event_ratelimit(memcg, | |
835 | MEM_CGROUP_TARGET_NUMAINFO); | |
836 | #endif | |
837 | preempt_enable(); | |
838 | ||
c0ff4b85 | 839 | mem_cgroup_threshold(memcg); |
f53d7ce3 | 840 | if (unlikely(do_softlimit)) |
c0ff4b85 | 841 | mem_cgroup_update_tree(memcg, page); |
453a9bf3 | 842 | #if MAX_NUMNODES > 1 |
f53d7ce3 | 843 | if (unlikely(do_numainfo)) |
c0ff4b85 | 844 | atomic_inc(&memcg->numainfo_events); |
453a9bf3 | 845 | #endif |
f53d7ce3 JW |
846 | } else |
847 | preempt_enable(); | |
d2265e6f KH |
848 | } |
849 | ||
d1a4c0b3 | 850 | struct mem_cgroup *mem_cgroup_from_cont(struct cgroup *cont) |
8cdea7c0 BS |
851 | { |
852 | return container_of(cgroup_subsys_state(cont, | |
853 | mem_cgroup_subsys_id), struct mem_cgroup, | |
854 | css); | |
855 | } | |
856 | ||
cf475ad2 | 857 | struct mem_cgroup *mem_cgroup_from_task(struct task_struct *p) |
78fb7466 | 858 | { |
31a78f23 BS |
859 | /* |
860 | * mm_update_next_owner() may clear mm->owner to NULL | |
861 | * if it races with swapoff, page migration, etc. | |
862 | * So this can be called with p == NULL. | |
863 | */ | |
864 | if (unlikely(!p)) | |
865 | return NULL; | |
866 | ||
78fb7466 PE |
867 | return container_of(task_subsys_state(p, mem_cgroup_subsys_id), |
868 | struct mem_cgroup, css); | |
869 | } | |
870 | ||
a433658c | 871 | struct mem_cgroup *try_get_mem_cgroup_from_mm(struct mm_struct *mm) |
54595fe2 | 872 | { |
c0ff4b85 | 873 | struct mem_cgroup *memcg = NULL; |
0b7f569e KH |
874 | |
875 | if (!mm) | |
876 | return NULL; | |
54595fe2 KH |
877 | /* |
878 | * Because we have no locks, mm->owner's may be being moved to other | |
879 | * cgroup. We use css_tryget() here even if this looks | |
880 | * pessimistic (rather than adding locks here). | |
881 | */ | |
882 | rcu_read_lock(); | |
883 | do { | |
c0ff4b85 R |
884 | memcg = mem_cgroup_from_task(rcu_dereference(mm->owner)); |
885 | if (unlikely(!memcg)) | |
54595fe2 | 886 | break; |
c0ff4b85 | 887 | } while (!css_tryget(&memcg->css)); |
54595fe2 | 888 | rcu_read_unlock(); |
c0ff4b85 | 889 | return memcg; |
54595fe2 KH |
890 | } |
891 | ||
5660048c JW |
892 | /** |
893 | * mem_cgroup_iter - iterate over memory cgroup hierarchy | |
894 | * @root: hierarchy root | |
895 | * @prev: previously returned memcg, NULL on first invocation | |
896 | * @reclaim: cookie for shared reclaim walks, NULL for full walks | |
897 | * | |
898 | * Returns references to children of the hierarchy below @root, or | |
899 | * @root itself, or %NULL after a full round-trip. | |
900 | * | |
901 | * Caller must pass the return value in @prev on subsequent | |
902 | * invocations for reference counting, or use mem_cgroup_iter_break() | |
903 | * to cancel a hierarchy walk before the round-trip is complete. | |
904 | * | |
905 | * Reclaimers can specify a zone and a priority level in @reclaim to | |
906 | * divide up the memcgs in the hierarchy among all concurrent | |
907 | * reclaimers operating on the same zone and priority. | |
908 | */ | |
909 | struct mem_cgroup *mem_cgroup_iter(struct mem_cgroup *root, | |
910 | struct mem_cgroup *prev, | |
911 | struct mem_cgroup_reclaim_cookie *reclaim) | |
14067bb3 | 912 | { |
9f3a0d09 JW |
913 | struct mem_cgroup *memcg = NULL; |
914 | int id = 0; | |
711d3d2c | 915 | |
5660048c JW |
916 | if (mem_cgroup_disabled()) |
917 | return NULL; | |
918 | ||
9f3a0d09 JW |
919 | if (!root) |
920 | root = root_mem_cgroup; | |
7d74b06f | 921 | |
9f3a0d09 JW |
922 | if (prev && !reclaim) |
923 | id = css_id(&prev->css); | |
14067bb3 | 924 | |
9f3a0d09 JW |
925 | if (prev && prev != root) |
926 | css_put(&prev->css); | |
14067bb3 | 927 | |
9f3a0d09 JW |
928 | if (!root->use_hierarchy && root != root_mem_cgroup) { |
929 | if (prev) | |
930 | return NULL; | |
931 | return root; | |
932 | } | |
14067bb3 | 933 | |
9f3a0d09 | 934 | while (!memcg) { |
527a5ec9 | 935 | struct mem_cgroup_reclaim_iter *uninitialized_var(iter); |
9f3a0d09 | 936 | struct cgroup_subsys_state *css; |
711d3d2c | 937 | |
527a5ec9 JW |
938 | if (reclaim) { |
939 | int nid = zone_to_nid(reclaim->zone); | |
940 | int zid = zone_idx(reclaim->zone); | |
941 | struct mem_cgroup_per_zone *mz; | |
942 | ||
943 | mz = mem_cgroup_zoneinfo(root, nid, zid); | |
944 | iter = &mz->reclaim_iter[reclaim->priority]; | |
945 | if (prev && reclaim->generation != iter->generation) | |
946 | return NULL; | |
947 | id = iter->position; | |
948 | } | |
7d74b06f | 949 | |
9f3a0d09 JW |
950 | rcu_read_lock(); |
951 | css = css_get_next(&mem_cgroup_subsys, id + 1, &root->css, &id); | |
952 | if (css) { | |
953 | if (css == &root->css || css_tryget(css)) | |
954 | memcg = container_of(css, | |
955 | struct mem_cgroup, css); | |
956 | } else | |
957 | id = 0; | |
14067bb3 | 958 | rcu_read_unlock(); |
14067bb3 | 959 | |
527a5ec9 JW |
960 | if (reclaim) { |
961 | iter->position = id; | |
962 | if (!css) | |
963 | iter->generation++; | |
964 | else if (!prev && memcg) | |
965 | reclaim->generation = iter->generation; | |
966 | } | |
9f3a0d09 JW |
967 | |
968 | if (prev && !css) | |
969 | return NULL; | |
970 | } | |
971 | return memcg; | |
14067bb3 | 972 | } |
7d74b06f | 973 | |
5660048c JW |
974 | /** |
975 | * mem_cgroup_iter_break - abort a hierarchy walk prematurely | |
976 | * @root: hierarchy root | |
977 | * @prev: last visited hierarchy member as returned by mem_cgroup_iter() | |
978 | */ | |
979 | void mem_cgroup_iter_break(struct mem_cgroup *root, | |
980 | struct mem_cgroup *prev) | |
9f3a0d09 JW |
981 | { |
982 | if (!root) | |
983 | root = root_mem_cgroup; | |
984 | if (prev && prev != root) | |
985 | css_put(&prev->css); | |
986 | } | |
7d74b06f | 987 | |
9f3a0d09 JW |
988 | /* |
989 | * Iteration constructs for visiting all cgroups (under a tree). If | |
990 | * loops are exited prematurely (break), mem_cgroup_iter_break() must | |
991 | * be used for reference counting. | |
992 | */ | |
993 | #define for_each_mem_cgroup_tree(iter, root) \ | |
527a5ec9 | 994 | for (iter = mem_cgroup_iter(root, NULL, NULL); \ |
9f3a0d09 | 995 | iter != NULL; \ |
527a5ec9 | 996 | iter = mem_cgroup_iter(root, iter, NULL)) |
711d3d2c | 997 | |
9f3a0d09 | 998 | #define for_each_mem_cgroup(iter) \ |
527a5ec9 | 999 | for (iter = mem_cgroup_iter(NULL, NULL, NULL); \ |
9f3a0d09 | 1000 | iter != NULL; \ |
527a5ec9 | 1001 | iter = mem_cgroup_iter(NULL, iter, NULL)) |
14067bb3 | 1002 | |
c0ff4b85 | 1003 | static inline bool mem_cgroup_is_root(struct mem_cgroup *memcg) |
4b3bde4c | 1004 | { |
c0ff4b85 | 1005 | return (memcg == root_mem_cgroup); |
4b3bde4c BS |
1006 | } |
1007 | ||
456f998e YH |
1008 | void mem_cgroup_count_vm_event(struct mm_struct *mm, enum vm_event_item idx) |
1009 | { | |
c0ff4b85 | 1010 | struct mem_cgroup *memcg; |
456f998e YH |
1011 | |
1012 | if (!mm) | |
1013 | return; | |
1014 | ||
1015 | rcu_read_lock(); | |
c0ff4b85 R |
1016 | memcg = mem_cgroup_from_task(rcu_dereference(mm->owner)); |
1017 | if (unlikely(!memcg)) | |
456f998e YH |
1018 | goto out; |
1019 | ||
1020 | switch (idx) { | |
456f998e | 1021 | case PGFAULT: |
0e574a93 JW |
1022 | this_cpu_inc(memcg->stat->events[MEM_CGROUP_EVENTS_PGFAULT]); |
1023 | break; | |
1024 | case PGMAJFAULT: | |
1025 | this_cpu_inc(memcg->stat->events[MEM_CGROUP_EVENTS_PGMAJFAULT]); | |
456f998e YH |
1026 | break; |
1027 | default: | |
1028 | BUG(); | |
1029 | } | |
1030 | out: | |
1031 | rcu_read_unlock(); | |
1032 | } | |
1033 | EXPORT_SYMBOL(mem_cgroup_count_vm_event); | |
1034 | ||
925b7673 JW |
1035 | /** |
1036 | * mem_cgroup_zone_lruvec - get the lru list vector for a zone and memcg | |
1037 | * @zone: zone of the wanted lruvec | |
fa9add64 | 1038 | * @memcg: memcg of the wanted lruvec |
925b7673 JW |
1039 | * |
1040 | * Returns the lru list vector holding pages for the given @zone and | |
1041 | * @mem. This can be the global zone lruvec, if the memory controller | |
1042 | * is disabled. | |
1043 | */ | |
1044 | struct lruvec *mem_cgroup_zone_lruvec(struct zone *zone, | |
1045 | struct mem_cgroup *memcg) | |
1046 | { | |
1047 | struct mem_cgroup_per_zone *mz; | |
1048 | ||
1049 | if (mem_cgroup_disabled()) | |
1050 | return &zone->lruvec; | |
1051 | ||
1052 | mz = mem_cgroup_zoneinfo(memcg, zone_to_nid(zone), zone_idx(zone)); | |
1053 | return &mz->lruvec; | |
1054 | } | |
1055 | ||
08e552c6 KH |
1056 | /* |
1057 | * Following LRU functions are allowed to be used without PCG_LOCK. | |
1058 | * Operations are called by routine of global LRU independently from memcg. | |
1059 | * What we have to take care of here is validness of pc->mem_cgroup. | |
1060 | * | |
1061 | * Changes to pc->mem_cgroup happens when | |
1062 | * 1. charge | |
1063 | * 2. moving account | |
1064 | * In typical case, "charge" is done before add-to-lru. Exception is SwapCache. | |
1065 | * It is added to LRU before charge. | |
1066 | * If PCG_USED bit is not set, page_cgroup is not added to this private LRU. | |
1067 | * When moving account, the page is not on LRU. It's isolated. | |
1068 | */ | |
4f98a2fe | 1069 | |
925b7673 | 1070 | /** |
fa9add64 | 1071 | * mem_cgroup_page_lruvec - return lruvec for adding an lru page |
925b7673 | 1072 | * @page: the page |
fa9add64 | 1073 | * @zone: zone of the page |
925b7673 | 1074 | */ |
fa9add64 | 1075 | struct lruvec *mem_cgroup_page_lruvec(struct page *page, struct zone *zone) |
08e552c6 | 1076 | { |
08e552c6 | 1077 | struct mem_cgroup_per_zone *mz; |
925b7673 JW |
1078 | struct mem_cgroup *memcg; |
1079 | struct page_cgroup *pc; | |
6d12e2d8 | 1080 | |
f8d66542 | 1081 | if (mem_cgroup_disabled()) |
925b7673 JW |
1082 | return &zone->lruvec; |
1083 | ||
08e552c6 | 1084 | pc = lookup_page_cgroup(page); |
38c5d72f | 1085 | memcg = pc->mem_cgroup; |
7512102c HD |
1086 | |
1087 | /* | |
fa9add64 | 1088 | * Surreptitiously switch any uncharged offlist page to root: |
7512102c HD |
1089 | * an uncharged page off lru does nothing to secure |
1090 | * its former mem_cgroup from sudden removal. | |
1091 | * | |
1092 | * Our caller holds lru_lock, and PageCgroupUsed is updated | |
1093 | * under page_cgroup lock: between them, they make all uses | |
1094 | * of pc->mem_cgroup safe. | |
1095 | */ | |
fa9add64 | 1096 | if (!PageLRU(page) && !PageCgroupUsed(pc) && memcg != root_mem_cgroup) |
7512102c HD |
1097 | pc->mem_cgroup = memcg = root_mem_cgroup; |
1098 | ||
925b7673 | 1099 | mz = page_cgroup_zoneinfo(memcg, page); |
925b7673 | 1100 | return &mz->lruvec; |
08e552c6 | 1101 | } |
b69408e8 | 1102 | |
925b7673 | 1103 | /** |
fa9add64 HD |
1104 | * mem_cgroup_update_lru_size - account for adding or removing an lru page |
1105 | * @lruvec: mem_cgroup per zone lru vector | |
1106 | * @lru: index of lru list the page is sitting on | |
1107 | * @nr_pages: positive when adding or negative when removing | |
925b7673 | 1108 | * |
fa9add64 HD |
1109 | * This function must be called when a page is added to or removed from an |
1110 | * lru list. | |
3f58a829 | 1111 | */ |
fa9add64 HD |
1112 | void mem_cgroup_update_lru_size(struct lruvec *lruvec, enum lru_list lru, |
1113 | int nr_pages) | |
3f58a829 MK |
1114 | { |
1115 | struct mem_cgroup_per_zone *mz; | |
fa9add64 | 1116 | unsigned long *lru_size; |
3f58a829 MK |
1117 | |
1118 | if (mem_cgroup_disabled()) | |
1119 | return; | |
1120 | ||
fa9add64 HD |
1121 | mz = container_of(lruvec, struct mem_cgroup_per_zone, lruvec); |
1122 | lru_size = mz->lru_size + lru; | |
1123 | *lru_size += nr_pages; | |
1124 | VM_BUG_ON((long)(*lru_size) < 0); | |
08e552c6 | 1125 | } |
544122e5 | 1126 | |
3e92041d | 1127 | /* |
c0ff4b85 | 1128 | * Checks whether given mem is same or in the root_mem_cgroup's |
3e92041d MH |
1129 | * hierarchy subtree |
1130 | */ | |
c3ac9a8a JW |
1131 | bool __mem_cgroup_same_or_subtree(const struct mem_cgroup *root_memcg, |
1132 | struct mem_cgroup *memcg) | |
3e92041d | 1133 | { |
91c63734 JW |
1134 | if (root_memcg == memcg) |
1135 | return true; | |
1136 | if (!root_memcg->use_hierarchy) | |
1137 | return false; | |
c3ac9a8a JW |
1138 | return css_is_ancestor(&memcg->css, &root_memcg->css); |
1139 | } | |
1140 | ||
1141 | static bool mem_cgroup_same_or_subtree(const struct mem_cgroup *root_memcg, | |
1142 | struct mem_cgroup *memcg) | |
1143 | { | |
1144 | bool ret; | |
1145 | ||
91c63734 | 1146 | rcu_read_lock(); |
c3ac9a8a | 1147 | ret = __mem_cgroup_same_or_subtree(root_memcg, memcg); |
91c63734 JW |
1148 | rcu_read_unlock(); |
1149 | return ret; | |
3e92041d MH |
1150 | } |
1151 | ||
c0ff4b85 | 1152 | int task_in_mem_cgroup(struct task_struct *task, const struct mem_cgroup *memcg) |
4c4a2214 DR |
1153 | { |
1154 | int ret; | |
0b7f569e | 1155 | struct mem_cgroup *curr = NULL; |
158e0a2d | 1156 | struct task_struct *p; |
4c4a2214 | 1157 | |
158e0a2d | 1158 | p = find_lock_task_mm(task); |
de077d22 DR |
1159 | if (p) { |
1160 | curr = try_get_mem_cgroup_from_mm(p->mm); | |
1161 | task_unlock(p); | |
1162 | } else { | |
1163 | /* | |
1164 | * All threads may have already detached their mm's, but the oom | |
1165 | * killer still needs to detect if they have already been oom | |
1166 | * killed to prevent needlessly killing additional tasks. | |
1167 | */ | |
1168 | task_lock(task); | |
1169 | curr = mem_cgroup_from_task(task); | |
1170 | if (curr) | |
1171 | css_get(&curr->css); | |
1172 | task_unlock(task); | |
1173 | } | |
0b7f569e KH |
1174 | if (!curr) |
1175 | return 0; | |
d31f56db | 1176 | /* |
c0ff4b85 | 1177 | * We should check use_hierarchy of "memcg" not "curr". Because checking |
d31f56db | 1178 | * use_hierarchy of "curr" here make this function true if hierarchy is |
c0ff4b85 R |
1179 | * enabled in "curr" and "curr" is a child of "memcg" in *cgroup* |
1180 | * hierarchy(even if use_hierarchy is disabled in "memcg"). | |
d31f56db | 1181 | */ |
c0ff4b85 | 1182 | ret = mem_cgroup_same_or_subtree(memcg, curr); |
0b7f569e | 1183 | css_put(&curr->css); |
4c4a2214 DR |
1184 | return ret; |
1185 | } | |
1186 | ||
c56d5c7d | 1187 | int mem_cgroup_inactive_anon_is_low(struct lruvec *lruvec) |
14797e23 | 1188 | { |
9b272977 | 1189 | unsigned long inactive_ratio; |
14797e23 | 1190 | unsigned long inactive; |
9b272977 | 1191 | unsigned long active; |
c772be93 | 1192 | unsigned long gb; |
14797e23 | 1193 | |
4d7dcca2 HD |
1194 | inactive = mem_cgroup_get_lru_size(lruvec, LRU_INACTIVE_ANON); |
1195 | active = mem_cgroup_get_lru_size(lruvec, LRU_ACTIVE_ANON); | |
14797e23 | 1196 | |
c772be93 KM |
1197 | gb = (inactive + active) >> (30 - PAGE_SHIFT); |
1198 | if (gb) | |
1199 | inactive_ratio = int_sqrt(10 * gb); | |
1200 | else | |
1201 | inactive_ratio = 1; | |
1202 | ||
9b272977 | 1203 | return inactive * inactive_ratio < active; |
14797e23 KM |
1204 | } |
1205 | ||
c56d5c7d | 1206 | int mem_cgroup_inactive_file_is_low(struct lruvec *lruvec) |
56e49d21 RR |
1207 | { |
1208 | unsigned long active; | |
1209 | unsigned long inactive; | |
1210 | ||
4d7dcca2 HD |
1211 | inactive = mem_cgroup_get_lru_size(lruvec, LRU_INACTIVE_FILE); |
1212 | active = mem_cgroup_get_lru_size(lruvec, LRU_ACTIVE_FILE); | |
56e49d21 RR |
1213 | |
1214 | return (active > inactive); | |
1215 | } | |
1216 | ||
6d61ef40 BS |
1217 | #define mem_cgroup_from_res_counter(counter, member) \ |
1218 | container_of(counter, struct mem_cgroup, member) | |
1219 | ||
19942822 | 1220 | /** |
9d11ea9f JW |
1221 | * mem_cgroup_margin - calculate chargeable space of a memory cgroup |
1222 | * @mem: the memory cgroup | |
19942822 | 1223 | * |
9d11ea9f | 1224 | * Returns the maximum amount of memory @mem can be charged with, in |
7ec99d62 | 1225 | * pages. |
19942822 | 1226 | */ |
c0ff4b85 | 1227 | static unsigned long mem_cgroup_margin(struct mem_cgroup *memcg) |
19942822 | 1228 | { |
9d11ea9f JW |
1229 | unsigned long long margin; |
1230 | ||
c0ff4b85 | 1231 | margin = res_counter_margin(&memcg->res); |
9d11ea9f | 1232 | if (do_swap_account) |
c0ff4b85 | 1233 | margin = min(margin, res_counter_margin(&memcg->memsw)); |
7ec99d62 | 1234 | return margin >> PAGE_SHIFT; |
19942822 JW |
1235 | } |
1236 | ||
1f4c025b | 1237 | int mem_cgroup_swappiness(struct mem_cgroup *memcg) |
a7885eb8 KM |
1238 | { |
1239 | struct cgroup *cgrp = memcg->css.cgroup; | |
a7885eb8 KM |
1240 | |
1241 | /* root ? */ | |
1242 | if (cgrp->parent == NULL) | |
1243 | return vm_swappiness; | |
1244 | ||
bf1ff263 | 1245 | return memcg->swappiness; |
a7885eb8 KM |
1246 | } |
1247 | ||
619d094b KH |
1248 | /* |
1249 | * memcg->moving_account is used for checking possibility that some thread is | |
1250 | * calling move_account(). When a thread on CPU-A starts moving pages under | |
1251 | * a memcg, other threads should check memcg->moving_account under | |
1252 | * rcu_read_lock(), like this: | |
1253 | * | |
1254 | * CPU-A CPU-B | |
1255 | * rcu_read_lock() | |
1256 | * memcg->moving_account+1 if (memcg->mocing_account) | |
1257 | * take heavy locks. | |
1258 | * synchronize_rcu() update something. | |
1259 | * rcu_read_unlock() | |
1260 | * start move here. | |
1261 | */ | |
4331f7d3 KH |
1262 | |
1263 | /* for quick checking without looking up memcg */ | |
1264 | atomic_t memcg_moving __read_mostly; | |
1265 | ||
c0ff4b85 | 1266 | static void mem_cgroup_start_move(struct mem_cgroup *memcg) |
32047e2a | 1267 | { |
4331f7d3 | 1268 | atomic_inc(&memcg_moving); |
619d094b | 1269 | atomic_inc(&memcg->moving_account); |
32047e2a KH |
1270 | synchronize_rcu(); |
1271 | } | |
1272 | ||
c0ff4b85 | 1273 | static void mem_cgroup_end_move(struct mem_cgroup *memcg) |
32047e2a | 1274 | { |
619d094b KH |
1275 | /* |
1276 | * Now, mem_cgroup_clear_mc() may call this function with NULL. | |
1277 | * We check NULL in callee rather than caller. | |
1278 | */ | |
4331f7d3 KH |
1279 | if (memcg) { |
1280 | atomic_dec(&memcg_moving); | |
619d094b | 1281 | atomic_dec(&memcg->moving_account); |
4331f7d3 | 1282 | } |
32047e2a | 1283 | } |
619d094b | 1284 | |
32047e2a KH |
1285 | /* |
1286 | * 2 routines for checking "mem" is under move_account() or not. | |
1287 | * | |
13fd1dd9 AM |
1288 | * mem_cgroup_stolen() - checking whether a cgroup is mc.from or not. This |
1289 | * is used for avoiding races in accounting. If true, | |
32047e2a KH |
1290 | * pc->mem_cgroup may be overwritten. |
1291 | * | |
1292 | * mem_cgroup_under_move() - checking a cgroup is mc.from or mc.to or | |
1293 | * under hierarchy of moving cgroups. This is for | |
1294 | * waiting at hith-memory prressure caused by "move". | |
1295 | */ | |
1296 | ||
13fd1dd9 | 1297 | static bool mem_cgroup_stolen(struct mem_cgroup *memcg) |
32047e2a KH |
1298 | { |
1299 | VM_BUG_ON(!rcu_read_lock_held()); | |
619d094b | 1300 | return atomic_read(&memcg->moving_account) > 0; |
32047e2a | 1301 | } |
4b534334 | 1302 | |
c0ff4b85 | 1303 | static bool mem_cgroup_under_move(struct mem_cgroup *memcg) |
4b534334 | 1304 | { |
2bd9bb20 KH |
1305 | struct mem_cgroup *from; |
1306 | struct mem_cgroup *to; | |
4b534334 | 1307 | bool ret = false; |
2bd9bb20 KH |
1308 | /* |
1309 | * Unlike task_move routines, we access mc.to, mc.from not under | |
1310 | * mutual exclusion by cgroup_mutex. Here, we take spinlock instead. | |
1311 | */ | |
1312 | spin_lock(&mc.lock); | |
1313 | from = mc.from; | |
1314 | to = mc.to; | |
1315 | if (!from) | |
1316 | goto unlock; | |
3e92041d | 1317 | |
c0ff4b85 R |
1318 | ret = mem_cgroup_same_or_subtree(memcg, from) |
1319 | || mem_cgroup_same_or_subtree(memcg, to); | |
2bd9bb20 KH |
1320 | unlock: |
1321 | spin_unlock(&mc.lock); | |
4b534334 KH |
1322 | return ret; |
1323 | } | |
1324 | ||
c0ff4b85 | 1325 | static bool mem_cgroup_wait_acct_move(struct mem_cgroup *memcg) |
4b534334 KH |
1326 | { |
1327 | if (mc.moving_task && current != mc.moving_task) { | |
c0ff4b85 | 1328 | if (mem_cgroup_under_move(memcg)) { |
4b534334 KH |
1329 | DEFINE_WAIT(wait); |
1330 | prepare_to_wait(&mc.waitq, &wait, TASK_INTERRUPTIBLE); | |
1331 | /* moving charge context might have finished. */ | |
1332 | if (mc.moving_task) | |
1333 | schedule(); | |
1334 | finish_wait(&mc.waitq, &wait); | |
1335 | return true; | |
1336 | } | |
1337 | } | |
1338 | return false; | |
1339 | } | |
1340 | ||
312734c0 KH |
1341 | /* |
1342 | * Take this lock when | |
1343 | * - a code tries to modify page's memcg while it's USED. | |
1344 | * - a code tries to modify page state accounting in a memcg. | |
13fd1dd9 | 1345 | * see mem_cgroup_stolen(), too. |
312734c0 KH |
1346 | */ |
1347 | static void move_lock_mem_cgroup(struct mem_cgroup *memcg, | |
1348 | unsigned long *flags) | |
1349 | { | |
1350 | spin_lock_irqsave(&memcg->move_lock, *flags); | |
1351 | } | |
1352 | ||
1353 | static void move_unlock_mem_cgroup(struct mem_cgroup *memcg, | |
1354 | unsigned long *flags) | |
1355 | { | |
1356 | spin_unlock_irqrestore(&memcg->move_lock, *flags); | |
1357 | } | |
1358 | ||
e222432b | 1359 | /** |
6a6135b6 | 1360 | * mem_cgroup_print_oom_info: Called from OOM with tasklist_lock held in read mode. |
e222432b BS |
1361 | * @memcg: The memory cgroup that went over limit |
1362 | * @p: Task that is going to be killed | |
1363 | * | |
1364 | * NOTE: @memcg and @p's mem_cgroup can be different when hierarchy is | |
1365 | * enabled | |
1366 | */ | |
1367 | void mem_cgroup_print_oom_info(struct mem_cgroup *memcg, struct task_struct *p) | |
1368 | { | |
1369 | struct cgroup *task_cgrp; | |
1370 | struct cgroup *mem_cgrp; | |
1371 | /* | |
1372 | * Need a buffer in BSS, can't rely on allocations. The code relies | |
1373 | * on the assumption that OOM is serialized for memory controller. | |
1374 | * If this assumption is broken, revisit this code. | |
1375 | */ | |
1376 | static char memcg_name[PATH_MAX]; | |
1377 | int ret; | |
1378 | ||
d31f56db | 1379 | if (!memcg || !p) |
e222432b BS |
1380 | return; |
1381 | ||
e222432b BS |
1382 | rcu_read_lock(); |
1383 | ||
1384 | mem_cgrp = memcg->css.cgroup; | |
1385 | task_cgrp = task_cgroup(p, mem_cgroup_subsys_id); | |
1386 | ||
1387 | ret = cgroup_path(task_cgrp, memcg_name, PATH_MAX); | |
1388 | if (ret < 0) { | |
1389 | /* | |
1390 | * Unfortunately, we are unable to convert to a useful name | |
1391 | * But we'll still print out the usage information | |
1392 | */ | |
1393 | rcu_read_unlock(); | |
1394 | goto done; | |
1395 | } | |
1396 | rcu_read_unlock(); | |
1397 | ||
1398 | printk(KERN_INFO "Task in %s killed", memcg_name); | |
1399 | ||
1400 | rcu_read_lock(); | |
1401 | ret = cgroup_path(mem_cgrp, memcg_name, PATH_MAX); | |
1402 | if (ret < 0) { | |
1403 | rcu_read_unlock(); | |
1404 | goto done; | |
1405 | } | |
1406 | rcu_read_unlock(); | |
1407 | ||
1408 | /* | |
1409 | * Continues from above, so we don't need an KERN_ level | |
1410 | */ | |
1411 | printk(KERN_CONT " as a result of limit of %s\n", memcg_name); | |
1412 | done: | |
1413 | ||
1414 | printk(KERN_INFO "memory: usage %llukB, limit %llukB, failcnt %llu\n", | |
1415 | res_counter_read_u64(&memcg->res, RES_USAGE) >> 10, | |
1416 | res_counter_read_u64(&memcg->res, RES_LIMIT) >> 10, | |
1417 | res_counter_read_u64(&memcg->res, RES_FAILCNT)); | |
1418 | printk(KERN_INFO "memory+swap: usage %llukB, limit %llukB, " | |
1419 | "failcnt %llu\n", | |
1420 | res_counter_read_u64(&memcg->memsw, RES_USAGE) >> 10, | |
1421 | res_counter_read_u64(&memcg->memsw, RES_LIMIT) >> 10, | |
1422 | res_counter_read_u64(&memcg->memsw, RES_FAILCNT)); | |
1423 | } | |
1424 | ||
81d39c20 KH |
1425 | /* |
1426 | * This function returns the number of memcg under hierarchy tree. Returns | |
1427 | * 1(self count) if no children. | |
1428 | */ | |
c0ff4b85 | 1429 | static int mem_cgroup_count_children(struct mem_cgroup *memcg) |
81d39c20 KH |
1430 | { |
1431 | int num = 0; | |
7d74b06f KH |
1432 | struct mem_cgroup *iter; |
1433 | ||
c0ff4b85 | 1434 | for_each_mem_cgroup_tree(iter, memcg) |
7d74b06f | 1435 | num++; |
81d39c20 KH |
1436 | return num; |
1437 | } | |
1438 | ||
a63d83f4 DR |
1439 | /* |
1440 | * Return the memory (and swap, if configured) limit for a memcg. | |
1441 | */ | |
1442 | u64 mem_cgroup_get_limit(struct mem_cgroup *memcg) | |
1443 | { | |
1444 | u64 limit; | |
1445 | u64 memsw; | |
1446 | ||
f3e8eb70 JW |
1447 | limit = res_counter_read_u64(&memcg->res, RES_LIMIT); |
1448 | limit += total_swap_pages << PAGE_SHIFT; | |
1449 | ||
a63d83f4 DR |
1450 | memsw = res_counter_read_u64(&memcg->memsw, RES_LIMIT); |
1451 | /* | |
1452 | * If memsw is finite and limits the amount of swap space available | |
1453 | * to this memcg, return that limit. | |
1454 | */ | |
1455 | return min(limit, memsw); | |
1456 | } | |
1457 | ||
5660048c JW |
1458 | static unsigned long mem_cgroup_reclaim(struct mem_cgroup *memcg, |
1459 | gfp_t gfp_mask, | |
1460 | unsigned long flags) | |
1461 | { | |
1462 | unsigned long total = 0; | |
1463 | bool noswap = false; | |
1464 | int loop; | |
1465 | ||
1466 | if (flags & MEM_CGROUP_RECLAIM_NOSWAP) | |
1467 | noswap = true; | |
1468 | if (!(flags & MEM_CGROUP_RECLAIM_SHRINK) && memcg->memsw_is_minimum) | |
1469 | noswap = true; | |
1470 | ||
1471 | for (loop = 0; loop < MEM_CGROUP_MAX_RECLAIM_LOOPS; loop++) { | |
1472 | if (loop) | |
1473 | drain_all_stock_async(memcg); | |
1474 | total += try_to_free_mem_cgroup_pages(memcg, gfp_mask, noswap); | |
1475 | /* | |
1476 | * Allow limit shrinkers, which are triggered directly | |
1477 | * by userspace, to catch signals and stop reclaim | |
1478 | * after minimal progress, regardless of the margin. | |
1479 | */ | |
1480 | if (total && (flags & MEM_CGROUP_RECLAIM_SHRINK)) | |
1481 | break; | |
1482 | if (mem_cgroup_margin(memcg)) | |
1483 | break; | |
1484 | /* | |
1485 | * If nothing was reclaimed after two attempts, there | |
1486 | * may be no reclaimable pages in this hierarchy. | |
1487 | */ | |
1488 | if (loop && !total) | |
1489 | break; | |
1490 | } | |
1491 | return total; | |
1492 | } | |
1493 | ||
4d0c066d KH |
1494 | /** |
1495 | * test_mem_cgroup_node_reclaimable | |
1496 | * @mem: the target memcg | |
1497 | * @nid: the node ID to be checked. | |
1498 | * @noswap : specify true here if the user wants flle only information. | |
1499 | * | |
1500 | * This function returns whether the specified memcg contains any | |
1501 | * reclaimable pages on a node. Returns true if there are any reclaimable | |
1502 | * pages in the node. | |
1503 | */ | |
c0ff4b85 | 1504 | static bool test_mem_cgroup_node_reclaimable(struct mem_cgroup *memcg, |
4d0c066d KH |
1505 | int nid, bool noswap) |
1506 | { | |
c0ff4b85 | 1507 | if (mem_cgroup_node_nr_lru_pages(memcg, nid, LRU_ALL_FILE)) |
4d0c066d KH |
1508 | return true; |
1509 | if (noswap || !total_swap_pages) | |
1510 | return false; | |
c0ff4b85 | 1511 | if (mem_cgroup_node_nr_lru_pages(memcg, nid, LRU_ALL_ANON)) |
4d0c066d KH |
1512 | return true; |
1513 | return false; | |
1514 | ||
1515 | } | |
889976db YH |
1516 | #if MAX_NUMNODES > 1 |
1517 | ||
1518 | /* | |
1519 | * Always updating the nodemask is not very good - even if we have an empty | |
1520 | * list or the wrong list here, we can start from some node and traverse all | |
1521 | * nodes based on the zonelist. So update the list loosely once per 10 secs. | |
1522 | * | |
1523 | */ | |
c0ff4b85 | 1524 | static void mem_cgroup_may_update_nodemask(struct mem_cgroup *memcg) |
889976db YH |
1525 | { |
1526 | int nid; | |
453a9bf3 KH |
1527 | /* |
1528 | * numainfo_events > 0 means there was at least NUMAINFO_EVENTS_TARGET | |
1529 | * pagein/pageout changes since the last update. | |
1530 | */ | |
c0ff4b85 | 1531 | if (!atomic_read(&memcg->numainfo_events)) |
453a9bf3 | 1532 | return; |
c0ff4b85 | 1533 | if (atomic_inc_return(&memcg->numainfo_updating) > 1) |
889976db YH |
1534 | return; |
1535 | ||
889976db | 1536 | /* make a nodemask where this memcg uses memory from */ |
c0ff4b85 | 1537 | memcg->scan_nodes = node_states[N_HIGH_MEMORY]; |
889976db YH |
1538 | |
1539 | for_each_node_mask(nid, node_states[N_HIGH_MEMORY]) { | |
1540 | ||
c0ff4b85 R |
1541 | if (!test_mem_cgroup_node_reclaimable(memcg, nid, false)) |
1542 | node_clear(nid, memcg->scan_nodes); | |
889976db | 1543 | } |
453a9bf3 | 1544 | |
c0ff4b85 R |
1545 | atomic_set(&memcg->numainfo_events, 0); |
1546 | atomic_set(&memcg->numainfo_updating, 0); | |
889976db YH |
1547 | } |
1548 | ||
1549 | /* | |
1550 | * Selecting a node where we start reclaim from. Because what we need is just | |
1551 | * reducing usage counter, start from anywhere is O,K. Considering | |
1552 | * memory reclaim from current node, there are pros. and cons. | |
1553 | * | |
1554 | * Freeing memory from current node means freeing memory from a node which | |
1555 | * we'll use or we've used. So, it may make LRU bad. And if several threads | |
1556 | * hit limits, it will see a contention on a node. But freeing from remote | |
1557 | * node means more costs for memory reclaim because of memory latency. | |
1558 | * | |
1559 | * Now, we use round-robin. Better algorithm is welcomed. | |
1560 | */ | |
c0ff4b85 | 1561 | int mem_cgroup_select_victim_node(struct mem_cgroup *memcg) |
889976db YH |
1562 | { |
1563 | int node; | |
1564 | ||
c0ff4b85 R |
1565 | mem_cgroup_may_update_nodemask(memcg); |
1566 | node = memcg->last_scanned_node; | |
889976db | 1567 | |
c0ff4b85 | 1568 | node = next_node(node, memcg->scan_nodes); |
889976db | 1569 | if (node == MAX_NUMNODES) |
c0ff4b85 | 1570 | node = first_node(memcg->scan_nodes); |
889976db YH |
1571 | /* |
1572 | * We call this when we hit limit, not when pages are added to LRU. | |
1573 | * No LRU may hold pages because all pages are UNEVICTABLE or | |
1574 | * memcg is too small and all pages are not on LRU. In that case, | |
1575 | * we use curret node. | |
1576 | */ | |
1577 | if (unlikely(node == MAX_NUMNODES)) | |
1578 | node = numa_node_id(); | |
1579 | ||
c0ff4b85 | 1580 | memcg->last_scanned_node = node; |
889976db YH |
1581 | return node; |
1582 | } | |
1583 | ||
4d0c066d KH |
1584 | /* |
1585 | * Check all nodes whether it contains reclaimable pages or not. | |
1586 | * For quick scan, we make use of scan_nodes. This will allow us to skip | |
1587 | * unused nodes. But scan_nodes is lazily updated and may not cotain | |
1588 | * enough new information. We need to do double check. | |
1589 | */ | |
6bbda35c | 1590 | static bool mem_cgroup_reclaimable(struct mem_cgroup *memcg, bool noswap) |
4d0c066d KH |
1591 | { |
1592 | int nid; | |
1593 | ||
1594 | /* | |
1595 | * quick check...making use of scan_node. | |
1596 | * We can skip unused nodes. | |
1597 | */ | |
c0ff4b85 R |
1598 | if (!nodes_empty(memcg->scan_nodes)) { |
1599 | for (nid = first_node(memcg->scan_nodes); | |
4d0c066d | 1600 | nid < MAX_NUMNODES; |
c0ff4b85 | 1601 | nid = next_node(nid, memcg->scan_nodes)) { |
4d0c066d | 1602 | |
c0ff4b85 | 1603 | if (test_mem_cgroup_node_reclaimable(memcg, nid, noswap)) |
4d0c066d KH |
1604 | return true; |
1605 | } | |
1606 | } | |
1607 | /* | |
1608 | * Check rest of nodes. | |
1609 | */ | |
1610 | for_each_node_state(nid, N_HIGH_MEMORY) { | |
c0ff4b85 | 1611 | if (node_isset(nid, memcg->scan_nodes)) |
4d0c066d | 1612 | continue; |
c0ff4b85 | 1613 | if (test_mem_cgroup_node_reclaimable(memcg, nid, noswap)) |
4d0c066d KH |
1614 | return true; |
1615 | } | |
1616 | return false; | |
1617 | } | |
1618 | ||
889976db | 1619 | #else |
c0ff4b85 | 1620 | int mem_cgroup_select_victim_node(struct mem_cgroup *memcg) |
889976db YH |
1621 | { |
1622 | return 0; | |
1623 | } | |
4d0c066d | 1624 | |
6bbda35c | 1625 | static bool mem_cgroup_reclaimable(struct mem_cgroup *memcg, bool noswap) |
4d0c066d | 1626 | { |
c0ff4b85 | 1627 | return test_mem_cgroup_node_reclaimable(memcg, 0, noswap); |
4d0c066d | 1628 | } |
889976db YH |
1629 | #endif |
1630 | ||
5660048c JW |
1631 | static int mem_cgroup_soft_reclaim(struct mem_cgroup *root_memcg, |
1632 | struct zone *zone, | |
1633 | gfp_t gfp_mask, | |
1634 | unsigned long *total_scanned) | |
6d61ef40 | 1635 | { |
9f3a0d09 | 1636 | struct mem_cgroup *victim = NULL; |
5660048c | 1637 | int total = 0; |
04046e1a | 1638 | int loop = 0; |
9d11ea9f | 1639 | unsigned long excess; |
185efc0f | 1640 | unsigned long nr_scanned; |
527a5ec9 JW |
1641 | struct mem_cgroup_reclaim_cookie reclaim = { |
1642 | .zone = zone, | |
1643 | .priority = 0, | |
1644 | }; | |
9d11ea9f | 1645 | |
c0ff4b85 | 1646 | excess = res_counter_soft_limit_excess(&root_memcg->res) >> PAGE_SHIFT; |
04046e1a | 1647 | |
4e416953 | 1648 | while (1) { |
527a5ec9 | 1649 | victim = mem_cgroup_iter(root_memcg, victim, &reclaim); |
9f3a0d09 | 1650 | if (!victim) { |
04046e1a | 1651 | loop++; |
4e416953 BS |
1652 | if (loop >= 2) { |
1653 | /* | |
1654 | * If we have not been able to reclaim | |
1655 | * anything, it might because there are | |
1656 | * no reclaimable pages under this hierarchy | |
1657 | */ | |
5660048c | 1658 | if (!total) |
4e416953 | 1659 | break; |
4e416953 | 1660 | /* |
25985edc | 1661 | * We want to do more targeted reclaim. |
4e416953 BS |
1662 | * excess >> 2 is not to excessive so as to |
1663 | * reclaim too much, nor too less that we keep | |
1664 | * coming back to reclaim from this cgroup | |
1665 | */ | |
1666 | if (total >= (excess >> 2) || | |
9f3a0d09 | 1667 | (loop > MEM_CGROUP_MAX_RECLAIM_LOOPS)) |
4e416953 | 1668 | break; |
4e416953 | 1669 | } |
9f3a0d09 | 1670 | continue; |
4e416953 | 1671 | } |
5660048c | 1672 | if (!mem_cgroup_reclaimable(victim, false)) |
6d61ef40 | 1673 | continue; |
5660048c JW |
1674 | total += mem_cgroup_shrink_node_zone(victim, gfp_mask, false, |
1675 | zone, &nr_scanned); | |
1676 | *total_scanned += nr_scanned; | |
1677 | if (!res_counter_soft_limit_excess(&root_memcg->res)) | |
9f3a0d09 | 1678 | break; |
6d61ef40 | 1679 | } |
9f3a0d09 | 1680 | mem_cgroup_iter_break(root_memcg, victim); |
04046e1a | 1681 | return total; |
6d61ef40 BS |
1682 | } |
1683 | ||
867578cb KH |
1684 | /* |
1685 | * Check OOM-Killer is already running under our hierarchy. | |
1686 | * If someone is running, return false. | |
1af8efe9 | 1687 | * Has to be called with memcg_oom_lock |
867578cb | 1688 | */ |
c0ff4b85 | 1689 | static bool mem_cgroup_oom_lock(struct mem_cgroup *memcg) |
867578cb | 1690 | { |
79dfdacc | 1691 | struct mem_cgroup *iter, *failed = NULL; |
a636b327 | 1692 | |
9f3a0d09 | 1693 | for_each_mem_cgroup_tree(iter, memcg) { |
23751be0 | 1694 | if (iter->oom_lock) { |
79dfdacc MH |
1695 | /* |
1696 | * this subtree of our hierarchy is already locked | |
1697 | * so we cannot give a lock. | |
1698 | */ | |
79dfdacc | 1699 | failed = iter; |
9f3a0d09 JW |
1700 | mem_cgroup_iter_break(memcg, iter); |
1701 | break; | |
23751be0 JW |
1702 | } else |
1703 | iter->oom_lock = true; | |
7d74b06f | 1704 | } |
867578cb | 1705 | |
79dfdacc | 1706 | if (!failed) |
23751be0 | 1707 | return true; |
79dfdacc MH |
1708 | |
1709 | /* | |
1710 | * OK, we failed to lock the whole subtree so we have to clean up | |
1711 | * what we set up to the failing subtree | |
1712 | */ | |
9f3a0d09 | 1713 | for_each_mem_cgroup_tree(iter, memcg) { |
79dfdacc | 1714 | if (iter == failed) { |
9f3a0d09 JW |
1715 | mem_cgroup_iter_break(memcg, iter); |
1716 | break; | |
79dfdacc MH |
1717 | } |
1718 | iter->oom_lock = false; | |
1719 | } | |
23751be0 | 1720 | return false; |
a636b327 | 1721 | } |
0b7f569e | 1722 | |
79dfdacc | 1723 | /* |
1af8efe9 | 1724 | * Has to be called with memcg_oom_lock |
79dfdacc | 1725 | */ |
c0ff4b85 | 1726 | static int mem_cgroup_oom_unlock(struct mem_cgroup *memcg) |
0b7f569e | 1727 | { |
7d74b06f KH |
1728 | struct mem_cgroup *iter; |
1729 | ||
c0ff4b85 | 1730 | for_each_mem_cgroup_tree(iter, memcg) |
79dfdacc MH |
1731 | iter->oom_lock = false; |
1732 | return 0; | |
1733 | } | |
1734 | ||
c0ff4b85 | 1735 | static void mem_cgroup_mark_under_oom(struct mem_cgroup *memcg) |
79dfdacc MH |
1736 | { |
1737 | struct mem_cgroup *iter; | |
1738 | ||
c0ff4b85 | 1739 | for_each_mem_cgroup_tree(iter, memcg) |
79dfdacc MH |
1740 | atomic_inc(&iter->under_oom); |
1741 | } | |
1742 | ||
c0ff4b85 | 1743 | static void mem_cgroup_unmark_under_oom(struct mem_cgroup *memcg) |
79dfdacc MH |
1744 | { |
1745 | struct mem_cgroup *iter; | |
1746 | ||
867578cb KH |
1747 | /* |
1748 | * When a new child is created while the hierarchy is under oom, | |
1749 | * mem_cgroup_oom_lock() may not be called. We have to use | |
1750 | * atomic_add_unless() here. | |
1751 | */ | |
c0ff4b85 | 1752 | for_each_mem_cgroup_tree(iter, memcg) |
79dfdacc | 1753 | atomic_add_unless(&iter->under_oom, -1, 0); |
0b7f569e KH |
1754 | } |
1755 | ||
1af8efe9 | 1756 | static DEFINE_SPINLOCK(memcg_oom_lock); |
867578cb KH |
1757 | static DECLARE_WAIT_QUEUE_HEAD(memcg_oom_waitq); |
1758 | ||
dc98df5a | 1759 | struct oom_wait_info { |
d79154bb | 1760 | struct mem_cgroup *memcg; |
dc98df5a KH |
1761 | wait_queue_t wait; |
1762 | }; | |
1763 | ||
1764 | static int memcg_oom_wake_function(wait_queue_t *wait, | |
1765 | unsigned mode, int sync, void *arg) | |
1766 | { | |
d79154bb HD |
1767 | struct mem_cgroup *wake_memcg = (struct mem_cgroup *)arg; |
1768 | struct mem_cgroup *oom_wait_memcg; | |
dc98df5a KH |
1769 | struct oom_wait_info *oom_wait_info; |
1770 | ||
1771 | oom_wait_info = container_of(wait, struct oom_wait_info, wait); | |
d79154bb | 1772 | oom_wait_memcg = oom_wait_info->memcg; |
dc98df5a | 1773 | |
dc98df5a | 1774 | /* |
d79154bb | 1775 | * Both of oom_wait_info->memcg and wake_memcg are stable under us. |
dc98df5a KH |
1776 | * Then we can use css_is_ancestor without taking care of RCU. |
1777 | */ | |
c0ff4b85 R |
1778 | if (!mem_cgroup_same_or_subtree(oom_wait_memcg, wake_memcg) |
1779 | && !mem_cgroup_same_or_subtree(wake_memcg, oom_wait_memcg)) | |
dc98df5a | 1780 | return 0; |
dc98df5a KH |
1781 | return autoremove_wake_function(wait, mode, sync, arg); |
1782 | } | |
1783 | ||
c0ff4b85 | 1784 | static void memcg_wakeup_oom(struct mem_cgroup *memcg) |
dc98df5a | 1785 | { |
c0ff4b85 R |
1786 | /* for filtering, pass "memcg" as argument. */ |
1787 | __wake_up(&memcg_oom_waitq, TASK_NORMAL, 0, memcg); | |
dc98df5a KH |
1788 | } |
1789 | ||
c0ff4b85 | 1790 | static void memcg_oom_recover(struct mem_cgroup *memcg) |
3c11ecf4 | 1791 | { |
c0ff4b85 R |
1792 | if (memcg && atomic_read(&memcg->under_oom)) |
1793 | memcg_wakeup_oom(memcg); | |
3c11ecf4 KH |
1794 | } |
1795 | ||
867578cb KH |
1796 | /* |
1797 | * try to call OOM killer. returns false if we should exit memory-reclaim loop. | |
1798 | */ | |
6bbda35c KS |
1799 | static bool mem_cgroup_handle_oom(struct mem_cgroup *memcg, gfp_t mask, |
1800 | int order) | |
0b7f569e | 1801 | { |
dc98df5a | 1802 | struct oom_wait_info owait; |
3c11ecf4 | 1803 | bool locked, need_to_kill; |
867578cb | 1804 | |
d79154bb | 1805 | owait.memcg = memcg; |
dc98df5a KH |
1806 | owait.wait.flags = 0; |
1807 | owait.wait.func = memcg_oom_wake_function; | |
1808 | owait.wait.private = current; | |
1809 | INIT_LIST_HEAD(&owait.wait.task_list); | |
3c11ecf4 | 1810 | need_to_kill = true; |
c0ff4b85 | 1811 | mem_cgroup_mark_under_oom(memcg); |
79dfdacc | 1812 | |
c0ff4b85 | 1813 | /* At first, try to OOM lock hierarchy under memcg.*/ |
1af8efe9 | 1814 | spin_lock(&memcg_oom_lock); |
c0ff4b85 | 1815 | locked = mem_cgroup_oom_lock(memcg); |
867578cb KH |
1816 | /* |
1817 | * Even if signal_pending(), we can't quit charge() loop without | |
1818 | * accounting. So, UNINTERRUPTIBLE is appropriate. But SIGKILL | |
1819 | * under OOM is always welcomed, use TASK_KILLABLE here. | |
1820 | */ | |
3c11ecf4 | 1821 | prepare_to_wait(&memcg_oom_waitq, &owait.wait, TASK_KILLABLE); |
c0ff4b85 | 1822 | if (!locked || memcg->oom_kill_disable) |
3c11ecf4 KH |
1823 | need_to_kill = false; |
1824 | if (locked) | |
c0ff4b85 | 1825 | mem_cgroup_oom_notify(memcg); |
1af8efe9 | 1826 | spin_unlock(&memcg_oom_lock); |
867578cb | 1827 | |
3c11ecf4 KH |
1828 | if (need_to_kill) { |
1829 | finish_wait(&memcg_oom_waitq, &owait.wait); | |
e845e199 | 1830 | mem_cgroup_out_of_memory(memcg, mask, order); |
3c11ecf4 | 1831 | } else { |
867578cb | 1832 | schedule(); |
dc98df5a | 1833 | finish_wait(&memcg_oom_waitq, &owait.wait); |
867578cb | 1834 | } |
1af8efe9 | 1835 | spin_lock(&memcg_oom_lock); |
79dfdacc | 1836 | if (locked) |
c0ff4b85 R |
1837 | mem_cgroup_oom_unlock(memcg); |
1838 | memcg_wakeup_oom(memcg); | |
1af8efe9 | 1839 | spin_unlock(&memcg_oom_lock); |
867578cb | 1840 | |
c0ff4b85 | 1841 | mem_cgroup_unmark_under_oom(memcg); |
79dfdacc | 1842 | |
867578cb KH |
1843 | if (test_thread_flag(TIF_MEMDIE) || fatal_signal_pending(current)) |
1844 | return false; | |
1845 | /* Give chance to dying process */ | |
715a5ee8 | 1846 | schedule_timeout_uninterruptible(1); |
867578cb | 1847 | return true; |
0b7f569e KH |
1848 | } |
1849 | ||
d69b042f BS |
1850 | /* |
1851 | * Currently used to update mapped file statistics, but the routine can be | |
1852 | * generalized to update other statistics as well. | |
32047e2a KH |
1853 | * |
1854 | * Notes: Race condition | |
1855 | * | |
1856 | * We usually use page_cgroup_lock() for accessing page_cgroup member but | |
1857 | * it tends to be costly. But considering some conditions, we doesn't need | |
1858 | * to do so _always_. | |
1859 | * | |
1860 | * Considering "charge", lock_page_cgroup() is not required because all | |
1861 | * file-stat operations happen after a page is attached to radix-tree. There | |
1862 | * are no race with "charge". | |
1863 | * | |
1864 | * Considering "uncharge", we know that memcg doesn't clear pc->mem_cgroup | |
1865 | * at "uncharge" intentionally. So, we always see valid pc->mem_cgroup even | |
1866 | * if there are race with "uncharge". Statistics itself is properly handled | |
1867 | * by flags. | |
1868 | * | |
1869 | * Considering "move", this is an only case we see a race. To make the race | |
619d094b KH |
1870 | * small, we check mm->moving_account and detect there are possibility of race |
1871 | * If there is, we take a lock. | |
d69b042f | 1872 | */ |
26174efd | 1873 | |
89c06bd5 KH |
1874 | void __mem_cgroup_begin_update_page_stat(struct page *page, |
1875 | bool *locked, unsigned long *flags) | |
1876 | { | |
1877 | struct mem_cgroup *memcg; | |
1878 | struct page_cgroup *pc; | |
1879 | ||
1880 | pc = lookup_page_cgroup(page); | |
1881 | again: | |
1882 | memcg = pc->mem_cgroup; | |
1883 | if (unlikely(!memcg || !PageCgroupUsed(pc))) | |
1884 | return; | |
1885 | /* | |
1886 | * If this memory cgroup is not under account moving, we don't | |
1887 | * need to take move_lock_page_cgroup(). Because we already hold | |
1888 | * rcu_read_lock(), any calls to move_account will be delayed until | |
13fd1dd9 | 1889 | * rcu_read_unlock() if mem_cgroup_stolen() == true. |
89c06bd5 | 1890 | */ |
13fd1dd9 | 1891 | if (!mem_cgroup_stolen(memcg)) |
89c06bd5 KH |
1892 | return; |
1893 | ||
1894 | move_lock_mem_cgroup(memcg, flags); | |
1895 | if (memcg != pc->mem_cgroup || !PageCgroupUsed(pc)) { | |
1896 | move_unlock_mem_cgroup(memcg, flags); | |
1897 | goto again; | |
1898 | } | |
1899 | *locked = true; | |
1900 | } | |
1901 | ||
1902 | void __mem_cgroup_end_update_page_stat(struct page *page, unsigned long *flags) | |
1903 | { | |
1904 | struct page_cgroup *pc = lookup_page_cgroup(page); | |
1905 | ||
1906 | /* | |
1907 | * It's guaranteed that pc->mem_cgroup never changes while | |
1908 | * lock is held because a routine modifies pc->mem_cgroup | |
1909 | * should take move_lock_page_cgroup(). | |
1910 | */ | |
1911 | move_unlock_mem_cgroup(pc->mem_cgroup, flags); | |
1912 | } | |
1913 | ||
2a7106f2 GT |
1914 | void mem_cgroup_update_page_stat(struct page *page, |
1915 | enum mem_cgroup_page_stat_item idx, int val) | |
d69b042f | 1916 | { |
c0ff4b85 | 1917 | struct mem_cgroup *memcg; |
32047e2a | 1918 | struct page_cgroup *pc = lookup_page_cgroup(page); |
dbd4ea78 | 1919 | unsigned long uninitialized_var(flags); |
d69b042f | 1920 | |
cfa44946 | 1921 | if (mem_cgroup_disabled()) |
d69b042f | 1922 | return; |
89c06bd5 | 1923 | |
c0ff4b85 R |
1924 | memcg = pc->mem_cgroup; |
1925 | if (unlikely(!memcg || !PageCgroupUsed(pc))) | |
89c06bd5 | 1926 | return; |
26174efd | 1927 | |
26174efd | 1928 | switch (idx) { |
2a7106f2 | 1929 | case MEMCG_NR_FILE_MAPPED: |
2a7106f2 | 1930 | idx = MEM_CGROUP_STAT_FILE_MAPPED; |
26174efd KH |
1931 | break; |
1932 | default: | |
1933 | BUG(); | |
8725d541 | 1934 | } |
d69b042f | 1935 | |
c0ff4b85 | 1936 | this_cpu_add(memcg->stat->count[idx], val); |
d69b042f | 1937 | } |
26174efd | 1938 | |
cdec2e42 KH |
1939 | /* |
1940 | * size of first charge trial. "32" comes from vmscan.c's magic value. | |
1941 | * TODO: maybe necessary to use big numbers in big irons. | |
1942 | */ | |
7ec99d62 | 1943 | #define CHARGE_BATCH 32U |
cdec2e42 KH |
1944 | struct memcg_stock_pcp { |
1945 | struct mem_cgroup *cached; /* this never be root cgroup */ | |
11c9ea4e | 1946 | unsigned int nr_pages; |
cdec2e42 | 1947 | struct work_struct work; |
26fe6168 | 1948 | unsigned long flags; |
a0db00fc | 1949 | #define FLUSHING_CACHED_CHARGE 0 |
cdec2e42 KH |
1950 | }; |
1951 | static DEFINE_PER_CPU(struct memcg_stock_pcp, memcg_stock); | |
9f50fad6 | 1952 | static DEFINE_MUTEX(percpu_charge_mutex); |
cdec2e42 KH |
1953 | |
1954 | /* | |
11c9ea4e | 1955 | * Try to consume stocked charge on this cpu. If success, one page is consumed |
cdec2e42 KH |
1956 | * from local stock and true is returned. If the stock is 0 or charges from a |
1957 | * cgroup which is not current target, returns false. This stock will be | |
1958 | * refilled. | |
1959 | */ | |
c0ff4b85 | 1960 | static bool consume_stock(struct mem_cgroup *memcg) |
cdec2e42 KH |
1961 | { |
1962 | struct memcg_stock_pcp *stock; | |
1963 | bool ret = true; | |
1964 | ||
1965 | stock = &get_cpu_var(memcg_stock); | |
c0ff4b85 | 1966 | if (memcg == stock->cached && stock->nr_pages) |
11c9ea4e | 1967 | stock->nr_pages--; |
cdec2e42 KH |
1968 | else /* need to call res_counter_charge */ |
1969 | ret = false; | |
1970 | put_cpu_var(memcg_stock); | |
1971 | return ret; | |
1972 | } | |
1973 | ||
1974 | /* | |
1975 | * Returns stocks cached in percpu to res_counter and reset cached information. | |
1976 | */ | |
1977 | static void drain_stock(struct memcg_stock_pcp *stock) | |
1978 | { | |
1979 | struct mem_cgroup *old = stock->cached; | |
1980 | ||
11c9ea4e JW |
1981 | if (stock->nr_pages) { |
1982 | unsigned long bytes = stock->nr_pages * PAGE_SIZE; | |
1983 | ||
1984 | res_counter_uncharge(&old->res, bytes); | |
cdec2e42 | 1985 | if (do_swap_account) |
11c9ea4e JW |
1986 | res_counter_uncharge(&old->memsw, bytes); |
1987 | stock->nr_pages = 0; | |
cdec2e42 KH |
1988 | } |
1989 | stock->cached = NULL; | |
cdec2e42 KH |
1990 | } |
1991 | ||
1992 | /* | |
1993 | * This must be called under preempt disabled or must be called by | |
1994 | * a thread which is pinned to local cpu. | |
1995 | */ | |
1996 | static void drain_local_stock(struct work_struct *dummy) | |
1997 | { | |
1998 | struct memcg_stock_pcp *stock = &__get_cpu_var(memcg_stock); | |
1999 | drain_stock(stock); | |
26fe6168 | 2000 | clear_bit(FLUSHING_CACHED_CHARGE, &stock->flags); |
cdec2e42 KH |
2001 | } |
2002 | ||
2003 | /* | |
2004 | * Cache charges(val) which is from res_counter, to local per_cpu area. | |
320cc51d | 2005 | * This will be consumed by consume_stock() function, later. |
cdec2e42 | 2006 | */ |
c0ff4b85 | 2007 | static void refill_stock(struct mem_cgroup *memcg, unsigned int nr_pages) |
cdec2e42 KH |
2008 | { |
2009 | struct memcg_stock_pcp *stock = &get_cpu_var(memcg_stock); | |
2010 | ||
c0ff4b85 | 2011 | if (stock->cached != memcg) { /* reset if necessary */ |
cdec2e42 | 2012 | drain_stock(stock); |
c0ff4b85 | 2013 | stock->cached = memcg; |
cdec2e42 | 2014 | } |
11c9ea4e | 2015 | stock->nr_pages += nr_pages; |
cdec2e42 KH |
2016 | put_cpu_var(memcg_stock); |
2017 | } | |
2018 | ||
2019 | /* | |
c0ff4b85 | 2020 | * Drains all per-CPU charge caches for given root_memcg resp. subtree |
d38144b7 MH |
2021 | * of the hierarchy under it. sync flag says whether we should block |
2022 | * until the work is done. | |
cdec2e42 | 2023 | */ |
c0ff4b85 | 2024 | static void drain_all_stock(struct mem_cgroup *root_memcg, bool sync) |
cdec2e42 | 2025 | { |
26fe6168 | 2026 | int cpu, curcpu; |
d38144b7 | 2027 | |
cdec2e42 | 2028 | /* Notify other cpus that system-wide "drain" is running */ |
cdec2e42 | 2029 | get_online_cpus(); |
5af12d0e | 2030 | curcpu = get_cpu(); |
cdec2e42 KH |
2031 | for_each_online_cpu(cpu) { |
2032 | struct memcg_stock_pcp *stock = &per_cpu(memcg_stock, cpu); | |
c0ff4b85 | 2033 | struct mem_cgroup *memcg; |
26fe6168 | 2034 | |
c0ff4b85 R |
2035 | memcg = stock->cached; |
2036 | if (!memcg || !stock->nr_pages) | |
26fe6168 | 2037 | continue; |
c0ff4b85 | 2038 | if (!mem_cgroup_same_or_subtree(root_memcg, memcg)) |
3e92041d | 2039 | continue; |
d1a05b69 MH |
2040 | if (!test_and_set_bit(FLUSHING_CACHED_CHARGE, &stock->flags)) { |
2041 | if (cpu == curcpu) | |
2042 | drain_local_stock(&stock->work); | |
2043 | else | |
2044 | schedule_work_on(cpu, &stock->work); | |
2045 | } | |
cdec2e42 | 2046 | } |
5af12d0e | 2047 | put_cpu(); |
d38144b7 MH |
2048 | |
2049 | if (!sync) | |
2050 | goto out; | |
2051 | ||
2052 | for_each_online_cpu(cpu) { | |
2053 | struct memcg_stock_pcp *stock = &per_cpu(memcg_stock, cpu); | |
9f50fad6 | 2054 | if (test_bit(FLUSHING_CACHED_CHARGE, &stock->flags)) |
d38144b7 MH |
2055 | flush_work(&stock->work); |
2056 | } | |
2057 | out: | |
cdec2e42 | 2058 | put_online_cpus(); |
d38144b7 MH |
2059 | } |
2060 | ||
2061 | /* | |
2062 | * Tries to drain stocked charges in other cpus. This function is asynchronous | |
2063 | * and just put a work per cpu for draining localy on each cpu. Caller can | |
2064 | * expects some charges will be back to res_counter later but cannot wait for | |
2065 | * it. | |
2066 | */ | |
c0ff4b85 | 2067 | static void drain_all_stock_async(struct mem_cgroup *root_memcg) |
d38144b7 | 2068 | { |
9f50fad6 MH |
2069 | /* |
2070 | * If someone calls draining, avoid adding more kworker runs. | |
2071 | */ | |
2072 | if (!mutex_trylock(&percpu_charge_mutex)) | |
2073 | return; | |
c0ff4b85 | 2074 | drain_all_stock(root_memcg, false); |
9f50fad6 | 2075 | mutex_unlock(&percpu_charge_mutex); |
cdec2e42 KH |
2076 | } |
2077 | ||
2078 | /* This is a synchronous drain interface. */ | |
c0ff4b85 | 2079 | static void drain_all_stock_sync(struct mem_cgroup *root_memcg) |
cdec2e42 KH |
2080 | { |
2081 | /* called when force_empty is called */ | |
9f50fad6 | 2082 | mutex_lock(&percpu_charge_mutex); |
c0ff4b85 | 2083 | drain_all_stock(root_memcg, true); |
9f50fad6 | 2084 | mutex_unlock(&percpu_charge_mutex); |
cdec2e42 KH |
2085 | } |
2086 | ||
711d3d2c KH |
2087 | /* |
2088 | * This function drains percpu counter value from DEAD cpu and | |
2089 | * move it to local cpu. Note that this function can be preempted. | |
2090 | */ | |
c0ff4b85 | 2091 | static void mem_cgroup_drain_pcp_counter(struct mem_cgroup *memcg, int cpu) |
711d3d2c KH |
2092 | { |
2093 | int i; | |
2094 | ||
c0ff4b85 | 2095 | spin_lock(&memcg->pcp_counter_lock); |
6104621d | 2096 | for (i = 0; i < MEM_CGROUP_STAT_NSTATS; i++) { |
c0ff4b85 | 2097 | long x = per_cpu(memcg->stat->count[i], cpu); |
711d3d2c | 2098 | |
c0ff4b85 R |
2099 | per_cpu(memcg->stat->count[i], cpu) = 0; |
2100 | memcg->nocpu_base.count[i] += x; | |
711d3d2c | 2101 | } |
e9f8974f | 2102 | for (i = 0; i < MEM_CGROUP_EVENTS_NSTATS; i++) { |
c0ff4b85 | 2103 | unsigned long x = per_cpu(memcg->stat->events[i], cpu); |
e9f8974f | 2104 | |
c0ff4b85 R |
2105 | per_cpu(memcg->stat->events[i], cpu) = 0; |
2106 | memcg->nocpu_base.events[i] += x; | |
e9f8974f | 2107 | } |
c0ff4b85 | 2108 | spin_unlock(&memcg->pcp_counter_lock); |
711d3d2c KH |
2109 | } |
2110 | ||
2111 | static int __cpuinit memcg_cpu_hotplug_callback(struct notifier_block *nb, | |
cdec2e42 KH |
2112 | unsigned long action, |
2113 | void *hcpu) | |
2114 | { | |
2115 | int cpu = (unsigned long)hcpu; | |
2116 | struct memcg_stock_pcp *stock; | |
711d3d2c | 2117 | struct mem_cgroup *iter; |
cdec2e42 | 2118 | |
619d094b | 2119 | if (action == CPU_ONLINE) |
1489ebad | 2120 | return NOTIFY_OK; |
1489ebad | 2121 | |
d833049b | 2122 | if (action != CPU_DEAD && action != CPU_DEAD_FROZEN) |
cdec2e42 | 2123 | return NOTIFY_OK; |
711d3d2c | 2124 | |
9f3a0d09 | 2125 | for_each_mem_cgroup(iter) |
711d3d2c KH |
2126 | mem_cgroup_drain_pcp_counter(iter, cpu); |
2127 | ||
cdec2e42 KH |
2128 | stock = &per_cpu(memcg_stock, cpu); |
2129 | drain_stock(stock); | |
2130 | return NOTIFY_OK; | |
2131 | } | |
2132 | ||
4b534334 KH |
2133 | |
2134 | /* See __mem_cgroup_try_charge() for details */ | |
2135 | enum { | |
2136 | CHARGE_OK, /* success */ | |
2137 | CHARGE_RETRY, /* need to retry but retry is not bad */ | |
2138 | CHARGE_NOMEM, /* we can't do more. return -ENOMEM */ | |
2139 | CHARGE_WOULDBLOCK, /* GFP_WAIT wasn't set and no enough res. */ | |
2140 | CHARGE_OOM_DIE, /* the current is killed because of OOM */ | |
2141 | }; | |
2142 | ||
c0ff4b85 | 2143 | static int mem_cgroup_do_charge(struct mem_cgroup *memcg, gfp_t gfp_mask, |
7ec99d62 | 2144 | unsigned int nr_pages, bool oom_check) |
4b534334 | 2145 | { |
7ec99d62 | 2146 | unsigned long csize = nr_pages * PAGE_SIZE; |
4b534334 KH |
2147 | struct mem_cgroup *mem_over_limit; |
2148 | struct res_counter *fail_res; | |
2149 | unsigned long flags = 0; | |
2150 | int ret; | |
2151 | ||
c0ff4b85 | 2152 | ret = res_counter_charge(&memcg->res, csize, &fail_res); |
4b534334 KH |
2153 | |
2154 | if (likely(!ret)) { | |
2155 | if (!do_swap_account) | |
2156 | return CHARGE_OK; | |
c0ff4b85 | 2157 | ret = res_counter_charge(&memcg->memsw, csize, &fail_res); |
4b534334 KH |
2158 | if (likely(!ret)) |
2159 | return CHARGE_OK; | |
2160 | ||
c0ff4b85 | 2161 | res_counter_uncharge(&memcg->res, csize); |
4b534334 KH |
2162 | mem_over_limit = mem_cgroup_from_res_counter(fail_res, memsw); |
2163 | flags |= MEM_CGROUP_RECLAIM_NOSWAP; | |
2164 | } else | |
2165 | mem_over_limit = mem_cgroup_from_res_counter(fail_res, res); | |
9221edb7 | 2166 | /* |
7ec99d62 JW |
2167 | * nr_pages can be either a huge page (HPAGE_PMD_NR), a batch |
2168 | * of regular pages (CHARGE_BATCH), or a single regular page (1). | |
9221edb7 JW |
2169 | * |
2170 | * Never reclaim on behalf of optional batching, retry with a | |
2171 | * single page instead. | |
2172 | */ | |
7ec99d62 | 2173 | if (nr_pages == CHARGE_BATCH) |
4b534334 KH |
2174 | return CHARGE_RETRY; |
2175 | ||
2176 | if (!(gfp_mask & __GFP_WAIT)) | |
2177 | return CHARGE_WOULDBLOCK; | |
2178 | ||
5660048c | 2179 | ret = mem_cgroup_reclaim(mem_over_limit, gfp_mask, flags); |
7ec99d62 | 2180 | if (mem_cgroup_margin(mem_over_limit) >= nr_pages) |
19942822 | 2181 | return CHARGE_RETRY; |
4b534334 | 2182 | /* |
19942822 JW |
2183 | * Even though the limit is exceeded at this point, reclaim |
2184 | * may have been able to free some pages. Retry the charge | |
2185 | * before killing the task. | |
2186 | * | |
2187 | * Only for regular pages, though: huge pages are rather | |
2188 | * unlikely to succeed so close to the limit, and we fall back | |
2189 | * to regular pages anyway in case of failure. | |
4b534334 | 2190 | */ |
7ec99d62 | 2191 | if (nr_pages == 1 && ret) |
4b534334 KH |
2192 | return CHARGE_RETRY; |
2193 | ||
2194 | /* | |
2195 | * At task move, charge accounts can be doubly counted. So, it's | |
2196 | * better to wait until the end of task_move if something is going on. | |
2197 | */ | |
2198 | if (mem_cgroup_wait_acct_move(mem_over_limit)) | |
2199 | return CHARGE_RETRY; | |
2200 | ||
2201 | /* If we don't need to call oom-killer at el, return immediately */ | |
2202 | if (!oom_check) | |
2203 | return CHARGE_NOMEM; | |
2204 | /* check OOM */ | |
e845e199 | 2205 | if (!mem_cgroup_handle_oom(mem_over_limit, gfp_mask, get_order(csize))) |
4b534334 KH |
2206 | return CHARGE_OOM_DIE; |
2207 | ||
2208 | return CHARGE_RETRY; | |
2209 | } | |
2210 | ||
f817ed48 | 2211 | /* |
38c5d72f KH |
2212 | * __mem_cgroup_try_charge() does |
2213 | * 1. detect memcg to be charged against from passed *mm and *ptr, | |
2214 | * 2. update res_counter | |
2215 | * 3. call memory reclaim if necessary. | |
2216 | * | |
2217 | * In some special case, if the task is fatal, fatal_signal_pending() or | |
2218 | * has TIF_MEMDIE, this function returns -EINTR while writing root_mem_cgroup | |
2219 | * to *ptr. There are two reasons for this. 1: fatal threads should quit as soon | |
2220 | * as possible without any hazards. 2: all pages should have a valid | |
2221 | * pc->mem_cgroup. If mm is NULL and the caller doesn't pass a valid memcg | |
2222 | * pointer, that is treated as a charge to root_mem_cgroup. | |
2223 | * | |
2224 | * So __mem_cgroup_try_charge() will return | |
2225 | * 0 ... on success, filling *ptr with a valid memcg pointer. | |
2226 | * -ENOMEM ... charge failure because of resource limits. | |
2227 | * -EINTR ... if thread is fatal. *ptr is filled with root_mem_cgroup. | |
2228 | * | |
2229 | * Unlike the exported interface, an "oom" parameter is added. if oom==true, | |
2230 | * the oom-killer can be invoked. | |
8a9f3ccd | 2231 | */ |
f817ed48 | 2232 | static int __mem_cgroup_try_charge(struct mm_struct *mm, |
ec168510 | 2233 | gfp_t gfp_mask, |
7ec99d62 | 2234 | unsigned int nr_pages, |
c0ff4b85 | 2235 | struct mem_cgroup **ptr, |
7ec99d62 | 2236 | bool oom) |
8a9f3ccd | 2237 | { |
7ec99d62 | 2238 | unsigned int batch = max(CHARGE_BATCH, nr_pages); |
4b534334 | 2239 | int nr_oom_retries = MEM_CGROUP_RECLAIM_RETRIES; |
c0ff4b85 | 2240 | struct mem_cgroup *memcg = NULL; |
4b534334 | 2241 | int ret; |
a636b327 | 2242 | |
867578cb KH |
2243 | /* |
2244 | * Unlike gloval-vm's OOM-kill, we're not in memory shortage | |
2245 | * in system level. So, allow to go ahead dying process in addition to | |
2246 | * MEMDIE process. | |
2247 | */ | |
2248 | if (unlikely(test_thread_flag(TIF_MEMDIE) | |
2249 | || fatal_signal_pending(current))) | |
2250 | goto bypass; | |
a636b327 | 2251 | |
8a9f3ccd | 2252 | /* |
3be91277 HD |
2253 | * We always charge the cgroup the mm_struct belongs to. |
2254 | * The mm_struct's mem_cgroup changes on task migration if the | |
8a9f3ccd BS |
2255 | * thread group leader migrates. It's possible that mm is not |
2256 | * set, if so charge the init_mm (happens for pagecache usage). | |
2257 | */ | |
c0ff4b85 | 2258 | if (!*ptr && !mm) |
38c5d72f | 2259 | *ptr = root_mem_cgroup; |
f75ca962 | 2260 | again: |
c0ff4b85 R |
2261 | if (*ptr) { /* css should be a valid one */ |
2262 | memcg = *ptr; | |
2263 | VM_BUG_ON(css_is_removed(&memcg->css)); | |
2264 | if (mem_cgroup_is_root(memcg)) | |
f75ca962 | 2265 | goto done; |
c0ff4b85 | 2266 | if (nr_pages == 1 && consume_stock(memcg)) |
f75ca962 | 2267 | goto done; |
c0ff4b85 | 2268 | css_get(&memcg->css); |
4b534334 | 2269 | } else { |
f75ca962 | 2270 | struct task_struct *p; |
54595fe2 | 2271 | |
f75ca962 KH |
2272 | rcu_read_lock(); |
2273 | p = rcu_dereference(mm->owner); | |
f75ca962 | 2274 | /* |
ebb76ce1 | 2275 | * Because we don't have task_lock(), "p" can exit. |
c0ff4b85 | 2276 | * In that case, "memcg" can point to root or p can be NULL with |
ebb76ce1 KH |
2277 | * race with swapoff. Then, we have small risk of mis-accouning. |
2278 | * But such kind of mis-account by race always happens because | |
2279 | * we don't have cgroup_mutex(). It's overkill and we allo that | |
2280 | * small race, here. | |
2281 | * (*) swapoff at el will charge against mm-struct not against | |
2282 | * task-struct. So, mm->owner can be NULL. | |
f75ca962 | 2283 | */ |
c0ff4b85 | 2284 | memcg = mem_cgroup_from_task(p); |
38c5d72f KH |
2285 | if (!memcg) |
2286 | memcg = root_mem_cgroup; | |
2287 | if (mem_cgroup_is_root(memcg)) { | |
f75ca962 KH |
2288 | rcu_read_unlock(); |
2289 | goto done; | |
2290 | } | |
c0ff4b85 | 2291 | if (nr_pages == 1 && consume_stock(memcg)) { |
f75ca962 KH |
2292 | /* |
2293 | * It seems dagerous to access memcg without css_get(). | |
2294 | * But considering how consume_stok works, it's not | |
2295 | * necessary. If consume_stock success, some charges | |
2296 | * from this memcg are cached on this cpu. So, we | |
2297 | * don't need to call css_get()/css_tryget() before | |
2298 | * calling consume_stock(). | |
2299 | */ | |
2300 | rcu_read_unlock(); | |
2301 | goto done; | |
2302 | } | |
2303 | /* after here, we may be blocked. we need to get refcnt */ | |
c0ff4b85 | 2304 | if (!css_tryget(&memcg->css)) { |
f75ca962 KH |
2305 | rcu_read_unlock(); |
2306 | goto again; | |
2307 | } | |
2308 | rcu_read_unlock(); | |
2309 | } | |
8a9f3ccd | 2310 | |
4b534334 KH |
2311 | do { |
2312 | bool oom_check; | |
7a81b88c | 2313 | |
4b534334 | 2314 | /* If killed, bypass charge */ |
f75ca962 | 2315 | if (fatal_signal_pending(current)) { |
c0ff4b85 | 2316 | css_put(&memcg->css); |
4b534334 | 2317 | goto bypass; |
f75ca962 | 2318 | } |
6d61ef40 | 2319 | |
4b534334 KH |
2320 | oom_check = false; |
2321 | if (oom && !nr_oom_retries) { | |
2322 | oom_check = true; | |
2323 | nr_oom_retries = MEM_CGROUP_RECLAIM_RETRIES; | |
cdec2e42 | 2324 | } |
66e1707b | 2325 | |
c0ff4b85 | 2326 | ret = mem_cgroup_do_charge(memcg, gfp_mask, batch, oom_check); |
4b534334 KH |
2327 | switch (ret) { |
2328 | case CHARGE_OK: | |
2329 | break; | |
2330 | case CHARGE_RETRY: /* not in OOM situation but retry */ | |
7ec99d62 | 2331 | batch = nr_pages; |
c0ff4b85 R |
2332 | css_put(&memcg->css); |
2333 | memcg = NULL; | |
f75ca962 | 2334 | goto again; |
4b534334 | 2335 | case CHARGE_WOULDBLOCK: /* !__GFP_WAIT */ |
c0ff4b85 | 2336 | css_put(&memcg->css); |
4b534334 KH |
2337 | goto nomem; |
2338 | case CHARGE_NOMEM: /* OOM routine works */ | |
f75ca962 | 2339 | if (!oom) { |
c0ff4b85 | 2340 | css_put(&memcg->css); |
867578cb | 2341 | goto nomem; |
f75ca962 | 2342 | } |
4b534334 KH |
2343 | /* If oom, we never return -ENOMEM */ |
2344 | nr_oom_retries--; | |
2345 | break; | |
2346 | case CHARGE_OOM_DIE: /* Killed by OOM Killer */ | |
c0ff4b85 | 2347 | css_put(&memcg->css); |
867578cb | 2348 | goto bypass; |
66e1707b | 2349 | } |
4b534334 KH |
2350 | } while (ret != CHARGE_OK); |
2351 | ||
7ec99d62 | 2352 | if (batch > nr_pages) |
c0ff4b85 R |
2353 | refill_stock(memcg, batch - nr_pages); |
2354 | css_put(&memcg->css); | |
0c3e73e8 | 2355 | done: |
c0ff4b85 | 2356 | *ptr = memcg; |
7a81b88c KH |
2357 | return 0; |
2358 | nomem: | |
c0ff4b85 | 2359 | *ptr = NULL; |
7a81b88c | 2360 | return -ENOMEM; |
867578cb | 2361 | bypass: |
38c5d72f KH |
2362 | *ptr = root_mem_cgroup; |
2363 | return -EINTR; | |
7a81b88c | 2364 | } |
8a9f3ccd | 2365 | |
a3032a2c DN |
2366 | /* |
2367 | * Somemtimes we have to undo a charge we got by try_charge(). | |
2368 | * This function is for that and do uncharge, put css's refcnt. | |
2369 | * gotten by try_charge(). | |
2370 | */ | |
c0ff4b85 | 2371 | static void __mem_cgroup_cancel_charge(struct mem_cgroup *memcg, |
e7018b8d | 2372 | unsigned int nr_pages) |
a3032a2c | 2373 | { |
c0ff4b85 | 2374 | if (!mem_cgroup_is_root(memcg)) { |
e7018b8d JW |
2375 | unsigned long bytes = nr_pages * PAGE_SIZE; |
2376 | ||
c0ff4b85 | 2377 | res_counter_uncharge(&memcg->res, bytes); |
a3032a2c | 2378 | if (do_swap_account) |
c0ff4b85 | 2379 | res_counter_uncharge(&memcg->memsw, bytes); |
a3032a2c | 2380 | } |
854ffa8d DN |
2381 | } |
2382 | ||
d01dd17f KH |
2383 | /* |
2384 | * Cancel chrages in this cgroup....doesn't propagate to parent cgroup. | |
2385 | * This is useful when moving usage to parent cgroup. | |
2386 | */ | |
2387 | static void __mem_cgroup_cancel_local_charge(struct mem_cgroup *memcg, | |
2388 | unsigned int nr_pages) | |
2389 | { | |
2390 | unsigned long bytes = nr_pages * PAGE_SIZE; | |
2391 | ||
2392 | if (mem_cgroup_is_root(memcg)) | |
2393 | return; | |
2394 | ||
2395 | res_counter_uncharge_until(&memcg->res, memcg->res.parent, bytes); | |
2396 | if (do_swap_account) | |
2397 | res_counter_uncharge_until(&memcg->memsw, | |
2398 | memcg->memsw.parent, bytes); | |
2399 | } | |
2400 | ||
a3b2d692 KH |
2401 | /* |
2402 | * A helper function to get mem_cgroup from ID. must be called under | |
2403 | * rcu_read_lock(). The caller must check css_is_removed() or some if | |
2404 | * it's concern. (dropping refcnt from swap can be called against removed | |
2405 | * memcg.) | |
2406 | */ | |
2407 | static struct mem_cgroup *mem_cgroup_lookup(unsigned short id) | |
2408 | { | |
2409 | struct cgroup_subsys_state *css; | |
2410 | ||
2411 | /* ID 0 is unused ID */ | |
2412 | if (!id) | |
2413 | return NULL; | |
2414 | css = css_lookup(&mem_cgroup_subsys, id); | |
2415 | if (!css) | |
2416 | return NULL; | |
2417 | return container_of(css, struct mem_cgroup, css); | |
2418 | } | |
2419 | ||
e42d9d5d | 2420 | struct mem_cgroup *try_get_mem_cgroup_from_page(struct page *page) |
b5a84319 | 2421 | { |
c0ff4b85 | 2422 | struct mem_cgroup *memcg = NULL; |
3c776e64 | 2423 | struct page_cgroup *pc; |
a3b2d692 | 2424 | unsigned short id; |
b5a84319 KH |
2425 | swp_entry_t ent; |
2426 | ||
3c776e64 DN |
2427 | VM_BUG_ON(!PageLocked(page)); |
2428 | ||
3c776e64 | 2429 | pc = lookup_page_cgroup(page); |
c0bd3f63 | 2430 | lock_page_cgroup(pc); |
a3b2d692 | 2431 | if (PageCgroupUsed(pc)) { |
c0ff4b85 R |
2432 | memcg = pc->mem_cgroup; |
2433 | if (memcg && !css_tryget(&memcg->css)) | |
2434 | memcg = NULL; | |
e42d9d5d | 2435 | } else if (PageSwapCache(page)) { |
3c776e64 | 2436 | ent.val = page_private(page); |
9fb4b7cc | 2437 | id = lookup_swap_cgroup_id(ent); |
a3b2d692 | 2438 | rcu_read_lock(); |
c0ff4b85 R |
2439 | memcg = mem_cgroup_lookup(id); |
2440 | if (memcg && !css_tryget(&memcg->css)) | |
2441 | memcg = NULL; | |
a3b2d692 | 2442 | rcu_read_unlock(); |
3c776e64 | 2443 | } |
c0bd3f63 | 2444 | unlock_page_cgroup(pc); |
c0ff4b85 | 2445 | return memcg; |
b5a84319 KH |
2446 | } |
2447 | ||
c0ff4b85 | 2448 | static void __mem_cgroup_commit_charge(struct mem_cgroup *memcg, |
5564e88b | 2449 | struct page *page, |
7ec99d62 | 2450 | unsigned int nr_pages, |
9ce70c02 HD |
2451 | enum charge_type ctype, |
2452 | bool lrucare) | |
7a81b88c | 2453 | { |
ce587e65 | 2454 | struct page_cgroup *pc = lookup_page_cgroup(page); |
9ce70c02 | 2455 | struct zone *uninitialized_var(zone); |
fa9add64 | 2456 | struct lruvec *lruvec; |
9ce70c02 | 2457 | bool was_on_lru = false; |
b2402857 | 2458 | bool anon; |
9ce70c02 | 2459 | |
ca3e0214 KH |
2460 | lock_page_cgroup(pc); |
2461 | if (unlikely(PageCgroupUsed(pc))) { | |
2462 | unlock_page_cgroup(pc); | |
c0ff4b85 | 2463 | __mem_cgroup_cancel_charge(memcg, nr_pages); |
ca3e0214 KH |
2464 | return; |
2465 | } | |
2466 | /* | |
2467 | * we don't need page_cgroup_lock about tail pages, becase they are not | |
2468 | * accessed by any other context at this point. | |
2469 | */ | |
9ce70c02 HD |
2470 | |
2471 | /* | |
2472 | * In some cases, SwapCache and FUSE(splice_buf->radixtree), the page | |
2473 | * may already be on some other mem_cgroup's LRU. Take care of it. | |
2474 | */ | |
2475 | if (lrucare) { | |
2476 | zone = page_zone(page); | |
2477 | spin_lock_irq(&zone->lru_lock); | |
2478 | if (PageLRU(page)) { | |
fa9add64 | 2479 | lruvec = mem_cgroup_zone_lruvec(zone, pc->mem_cgroup); |
9ce70c02 | 2480 | ClearPageLRU(page); |
fa9add64 | 2481 | del_page_from_lru_list(page, lruvec, page_lru(page)); |
9ce70c02 HD |
2482 | was_on_lru = true; |
2483 | } | |
2484 | } | |
2485 | ||
c0ff4b85 | 2486 | pc->mem_cgroup = memcg; |
261fb61a KH |
2487 | /* |
2488 | * We access a page_cgroup asynchronously without lock_page_cgroup(). | |
2489 | * Especially when a page_cgroup is taken from a page, pc->mem_cgroup | |
2490 | * is accessed after testing USED bit. To make pc->mem_cgroup visible | |
2491 | * before USED bit, we need memory barrier here. | |
2492 | * See mem_cgroup_add_lru_list(), etc. | |
2493 | */ | |
08e552c6 | 2494 | smp_wmb(); |
b2402857 | 2495 | SetPageCgroupUsed(pc); |
3be91277 | 2496 | |
9ce70c02 HD |
2497 | if (lrucare) { |
2498 | if (was_on_lru) { | |
fa9add64 | 2499 | lruvec = mem_cgroup_zone_lruvec(zone, pc->mem_cgroup); |
9ce70c02 HD |
2500 | VM_BUG_ON(PageLRU(page)); |
2501 | SetPageLRU(page); | |
fa9add64 | 2502 | add_page_to_lru_list(page, lruvec, page_lru(page)); |
9ce70c02 HD |
2503 | } |
2504 | spin_unlock_irq(&zone->lru_lock); | |
2505 | } | |
2506 | ||
b2402857 KH |
2507 | if (ctype == MEM_CGROUP_CHARGE_TYPE_MAPPED) |
2508 | anon = true; | |
2509 | else | |
2510 | anon = false; | |
2511 | ||
2512 | mem_cgroup_charge_statistics(memcg, anon, nr_pages); | |
52d4b9ac | 2513 | unlock_page_cgroup(pc); |
9ce70c02 | 2514 | |
430e4863 KH |
2515 | /* |
2516 | * "charge_statistics" updated event counter. Then, check it. | |
2517 | * Insert ancestor (and ancestor's ancestors), to softlimit RB-tree. | |
2518 | * if they exceeds softlimit. | |
2519 | */ | |
c0ff4b85 | 2520 | memcg_check_events(memcg, page); |
7a81b88c | 2521 | } |
66e1707b | 2522 | |
ca3e0214 KH |
2523 | #ifdef CONFIG_TRANSPARENT_HUGEPAGE |
2524 | ||
a0db00fc | 2525 | #define PCGF_NOCOPY_AT_SPLIT (1 << PCG_LOCK | 1 << PCG_MIGRATION) |
ca3e0214 KH |
2526 | /* |
2527 | * Because tail pages are not marked as "used", set it. We're under | |
e94c8a9c KH |
2528 | * zone->lru_lock, 'splitting on pmd' and compound_lock. |
2529 | * charge/uncharge will be never happen and move_account() is done under | |
2530 | * compound_lock(), so we don't have to take care of races. | |
ca3e0214 | 2531 | */ |
e94c8a9c | 2532 | void mem_cgroup_split_huge_fixup(struct page *head) |
ca3e0214 KH |
2533 | { |
2534 | struct page_cgroup *head_pc = lookup_page_cgroup(head); | |
e94c8a9c KH |
2535 | struct page_cgroup *pc; |
2536 | int i; | |
ca3e0214 | 2537 | |
3d37c4a9 KH |
2538 | if (mem_cgroup_disabled()) |
2539 | return; | |
e94c8a9c KH |
2540 | for (i = 1; i < HPAGE_PMD_NR; i++) { |
2541 | pc = head_pc + i; | |
2542 | pc->mem_cgroup = head_pc->mem_cgroup; | |
2543 | smp_wmb();/* see __commit_charge() */ | |
e94c8a9c KH |
2544 | pc->flags = head_pc->flags & ~PCGF_NOCOPY_AT_SPLIT; |
2545 | } | |
ca3e0214 | 2546 | } |
12d27107 | 2547 | #endif /* CONFIG_TRANSPARENT_HUGEPAGE */ |
ca3e0214 | 2548 | |
f817ed48 | 2549 | /** |
de3638d9 | 2550 | * mem_cgroup_move_account - move account of the page |
5564e88b | 2551 | * @page: the page |
7ec99d62 | 2552 | * @nr_pages: number of regular pages (>1 for huge pages) |
f817ed48 KH |
2553 | * @pc: page_cgroup of the page. |
2554 | * @from: mem_cgroup which the page is moved from. | |
2555 | * @to: mem_cgroup which the page is moved to. @from != @to. | |
2556 | * | |
2557 | * The caller must confirm following. | |
08e552c6 | 2558 | * - page is not on LRU (isolate_page() is useful.) |
7ec99d62 | 2559 | * - compound_lock is held when nr_pages > 1 |
f817ed48 | 2560 | * |
2f3479b1 KH |
2561 | * This function doesn't do "charge" to new cgroup and doesn't do "uncharge" |
2562 | * from old cgroup. | |
f817ed48 | 2563 | */ |
7ec99d62 JW |
2564 | static int mem_cgroup_move_account(struct page *page, |
2565 | unsigned int nr_pages, | |
2566 | struct page_cgroup *pc, | |
2567 | struct mem_cgroup *from, | |
2f3479b1 | 2568 | struct mem_cgroup *to) |
f817ed48 | 2569 | { |
de3638d9 JW |
2570 | unsigned long flags; |
2571 | int ret; | |
b2402857 | 2572 | bool anon = PageAnon(page); |
987eba66 | 2573 | |
f817ed48 | 2574 | VM_BUG_ON(from == to); |
5564e88b | 2575 | VM_BUG_ON(PageLRU(page)); |
de3638d9 JW |
2576 | /* |
2577 | * The page is isolated from LRU. So, collapse function | |
2578 | * will not handle this page. But page splitting can happen. | |
2579 | * Do this check under compound_page_lock(). The caller should | |
2580 | * hold it. | |
2581 | */ | |
2582 | ret = -EBUSY; | |
7ec99d62 | 2583 | if (nr_pages > 1 && !PageTransHuge(page)) |
de3638d9 JW |
2584 | goto out; |
2585 | ||
2586 | lock_page_cgroup(pc); | |
2587 | ||
2588 | ret = -EINVAL; | |
2589 | if (!PageCgroupUsed(pc) || pc->mem_cgroup != from) | |
2590 | goto unlock; | |
2591 | ||
312734c0 | 2592 | move_lock_mem_cgroup(from, &flags); |
f817ed48 | 2593 | |
2ff76f11 | 2594 | if (!anon && page_mapped(page)) { |
c62b1a3b KH |
2595 | /* Update mapped_file data for mem_cgroup */ |
2596 | preempt_disable(); | |
2597 | __this_cpu_dec(from->stat->count[MEM_CGROUP_STAT_FILE_MAPPED]); | |
2598 | __this_cpu_inc(to->stat->count[MEM_CGROUP_STAT_FILE_MAPPED]); | |
2599 | preempt_enable(); | |
d69b042f | 2600 | } |
b2402857 | 2601 | mem_cgroup_charge_statistics(from, anon, -nr_pages); |
d69b042f | 2602 | |
854ffa8d | 2603 | /* caller should have done css_get */ |
08e552c6 | 2604 | pc->mem_cgroup = to; |
b2402857 | 2605 | mem_cgroup_charge_statistics(to, anon, nr_pages); |
88703267 KH |
2606 | /* |
2607 | * We charges against "to" which may not have any tasks. Then, "to" | |
2608 | * can be under rmdir(). But in current implementation, caller of | |
4ffef5fe | 2609 | * this function is just force_empty() and move charge, so it's |
25985edc | 2610 | * guaranteed that "to" is never removed. So, we don't check rmdir |
4ffef5fe | 2611 | * status here. |
88703267 | 2612 | */ |
312734c0 | 2613 | move_unlock_mem_cgroup(from, &flags); |
de3638d9 JW |
2614 | ret = 0; |
2615 | unlock: | |
57f9fd7d | 2616 | unlock_page_cgroup(pc); |
d2265e6f KH |
2617 | /* |
2618 | * check events | |
2619 | */ | |
5564e88b JW |
2620 | memcg_check_events(to, page); |
2621 | memcg_check_events(from, page); | |
de3638d9 | 2622 | out: |
f817ed48 KH |
2623 | return ret; |
2624 | } | |
2625 | ||
2626 | /* | |
2627 | * move charges to its parent. | |
2628 | */ | |
2629 | ||
5564e88b JW |
2630 | static int mem_cgroup_move_parent(struct page *page, |
2631 | struct page_cgroup *pc, | |
f817ed48 KH |
2632 | struct mem_cgroup *child, |
2633 | gfp_t gfp_mask) | |
2634 | { | |
f817ed48 | 2635 | struct mem_cgroup *parent; |
7ec99d62 | 2636 | unsigned int nr_pages; |
4be4489f | 2637 | unsigned long uninitialized_var(flags); |
f817ed48 KH |
2638 | int ret; |
2639 | ||
2640 | /* Is ROOT ? */ | |
cc926f78 | 2641 | if (mem_cgroup_is_root(child)) |
f817ed48 KH |
2642 | return -EINVAL; |
2643 | ||
57f9fd7d DN |
2644 | ret = -EBUSY; |
2645 | if (!get_page_unless_zero(page)) | |
2646 | goto out; | |
2647 | if (isolate_lru_page(page)) | |
2648 | goto put; | |
52dbb905 | 2649 | |
7ec99d62 | 2650 | nr_pages = hpage_nr_pages(page); |
08e552c6 | 2651 | |
cc926f78 KH |
2652 | parent = parent_mem_cgroup(child); |
2653 | /* | |
2654 | * If no parent, move charges to root cgroup. | |
2655 | */ | |
2656 | if (!parent) | |
2657 | parent = root_mem_cgroup; | |
f817ed48 | 2658 | |
7ec99d62 | 2659 | if (nr_pages > 1) |
987eba66 KH |
2660 | flags = compound_lock_irqsave(page); |
2661 | ||
cc926f78 | 2662 | ret = mem_cgroup_move_account(page, nr_pages, |
2f3479b1 | 2663 | pc, child, parent); |
cc926f78 KH |
2664 | if (!ret) |
2665 | __mem_cgroup_cancel_local_charge(child, nr_pages); | |
8dba474f | 2666 | |
7ec99d62 | 2667 | if (nr_pages > 1) |
987eba66 | 2668 | compound_unlock_irqrestore(page, flags); |
08e552c6 | 2669 | putback_lru_page(page); |
57f9fd7d | 2670 | put: |
40d58138 | 2671 | put_page(page); |
57f9fd7d | 2672 | out: |
f817ed48 KH |
2673 | return ret; |
2674 | } | |
2675 | ||
7a81b88c KH |
2676 | /* |
2677 | * Charge the memory controller for page usage. | |
2678 | * Return | |
2679 | * 0 if the charge was successful | |
2680 | * < 0 if the cgroup is over its limit | |
2681 | */ | |
2682 | static int mem_cgroup_charge_common(struct page *page, struct mm_struct *mm, | |
73045c47 | 2683 | gfp_t gfp_mask, enum charge_type ctype) |
7a81b88c | 2684 | { |
c0ff4b85 | 2685 | struct mem_cgroup *memcg = NULL; |
7ec99d62 | 2686 | unsigned int nr_pages = 1; |
8493ae43 | 2687 | bool oom = true; |
7a81b88c | 2688 | int ret; |
ec168510 | 2689 | |
37c2ac78 | 2690 | if (PageTransHuge(page)) { |
7ec99d62 | 2691 | nr_pages <<= compound_order(page); |
37c2ac78 | 2692 | VM_BUG_ON(!PageTransHuge(page)); |
8493ae43 JW |
2693 | /* |
2694 | * Never OOM-kill a process for a huge page. The | |
2695 | * fault handler will fall back to regular pages. | |
2696 | */ | |
2697 | oom = false; | |
37c2ac78 | 2698 | } |
7a81b88c | 2699 | |
c0ff4b85 | 2700 | ret = __mem_cgroup_try_charge(mm, gfp_mask, nr_pages, &memcg, oom); |
38c5d72f | 2701 | if (ret == -ENOMEM) |
7a81b88c | 2702 | return ret; |
ce587e65 | 2703 | __mem_cgroup_commit_charge(memcg, page, nr_pages, ctype, false); |
8a9f3ccd | 2704 | return 0; |
8a9f3ccd BS |
2705 | } |
2706 | ||
7a81b88c KH |
2707 | int mem_cgroup_newpage_charge(struct page *page, |
2708 | struct mm_struct *mm, gfp_t gfp_mask) | |
217bc319 | 2709 | { |
f8d66542 | 2710 | if (mem_cgroup_disabled()) |
cede86ac | 2711 | return 0; |
7a0524cf JW |
2712 | VM_BUG_ON(page_mapped(page)); |
2713 | VM_BUG_ON(page->mapping && !PageAnon(page)); | |
2714 | VM_BUG_ON(!mm); | |
217bc319 | 2715 | return mem_cgroup_charge_common(page, mm, gfp_mask, |
7a0524cf | 2716 | MEM_CGROUP_CHARGE_TYPE_MAPPED); |
217bc319 KH |
2717 | } |
2718 | ||
83aae4c7 DN |
2719 | static void |
2720 | __mem_cgroup_commit_charge_swapin(struct page *page, struct mem_cgroup *ptr, | |
2721 | enum charge_type ctype); | |
2722 | ||
e1a1cd59 BS |
2723 | int mem_cgroup_cache_charge(struct page *page, struct mm_struct *mm, |
2724 | gfp_t gfp_mask) | |
8697d331 | 2725 | { |
c0ff4b85 | 2726 | struct mem_cgroup *memcg = NULL; |
dc67d504 | 2727 | enum charge_type type = MEM_CGROUP_CHARGE_TYPE_CACHE; |
b5a84319 KH |
2728 | int ret; |
2729 | ||
f8d66542 | 2730 | if (mem_cgroup_disabled()) |
cede86ac | 2731 | return 0; |
52d4b9ac KH |
2732 | if (PageCompound(page)) |
2733 | return 0; | |
accf163e | 2734 | |
73045c47 | 2735 | if (unlikely(!mm)) |
8697d331 | 2736 | mm = &init_mm; |
dc67d504 KH |
2737 | if (!page_is_file_cache(page)) |
2738 | type = MEM_CGROUP_CHARGE_TYPE_SHMEM; | |
accf163e | 2739 | |
38c5d72f | 2740 | if (!PageSwapCache(page)) |
dc67d504 | 2741 | ret = mem_cgroup_charge_common(page, mm, gfp_mask, type); |
38c5d72f | 2742 | else { /* page is swapcache/shmem */ |
c0ff4b85 | 2743 | ret = mem_cgroup_try_charge_swapin(mm, page, gfp_mask, &memcg); |
83aae4c7 | 2744 | if (!ret) |
dc67d504 KH |
2745 | __mem_cgroup_commit_charge_swapin(page, memcg, type); |
2746 | } | |
b5a84319 | 2747 | return ret; |
e8589cc1 KH |
2748 | } |
2749 | ||
54595fe2 KH |
2750 | /* |
2751 | * While swap-in, try_charge -> commit or cancel, the page is locked. | |
2752 | * And when try_charge() successfully returns, one refcnt to memcg without | |
21ae2956 | 2753 | * struct page_cgroup is acquired. This refcnt will be consumed by |
54595fe2 KH |
2754 | * "commit()" or removed by "cancel()" |
2755 | */ | |
8c7c6e34 KH |
2756 | int mem_cgroup_try_charge_swapin(struct mm_struct *mm, |
2757 | struct page *page, | |
72835c86 | 2758 | gfp_t mask, struct mem_cgroup **memcgp) |
8c7c6e34 | 2759 | { |
c0ff4b85 | 2760 | struct mem_cgroup *memcg; |
54595fe2 | 2761 | int ret; |
8c7c6e34 | 2762 | |
72835c86 | 2763 | *memcgp = NULL; |
56039efa | 2764 | |
f8d66542 | 2765 | if (mem_cgroup_disabled()) |
8c7c6e34 KH |
2766 | return 0; |
2767 | ||
2768 | if (!do_swap_account) | |
2769 | goto charge_cur_mm; | |
8c7c6e34 KH |
2770 | /* |
2771 | * A racing thread's fault, or swapoff, may have already updated | |
407f9c8b HD |
2772 | * the pte, and even removed page from swap cache: in those cases |
2773 | * do_swap_page()'s pte_same() test will fail; but there's also a | |
2774 | * KSM case which does need to charge the page. | |
8c7c6e34 KH |
2775 | */ |
2776 | if (!PageSwapCache(page)) | |
407f9c8b | 2777 | goto charge_cur_mm; |
c0ff4b85 R |
2778 | memcg = try_get_mem_cgroup_from_page(page); |
2779 | if (!memcg) | |
54595fe2 | 2780 | goto charge_cur_mm; |
72835c86 JW |
2781 | *memcgp = memcg; |
2782 | ret = __mem_cgroup_try_charge(NULL, mask, 1, memcgp, true); | |
c0ff4b85 | 2783 | css_put(&memcg->css); |
38c5d72f KH |
2784 | if (ret == -EINTR) |
2785 | ret = 0; | |
54595fe2 | 2786 | return ret; |
8c7c6e34 KH |
2787 | charge_cur_mm: |
2788 | if (unlikely(!mm)) | |
2789 | mm = &init_mm; | |
38c5d72f KH |
2790 | ret = __mem_cgroup_try_charge(mm, mask, 1, memcgp, true); |
2791 | if (ret == -EINTR) | |
2792 | ret = 0; | |
2793 | return ret; | |
8c7c6e34 KH |
2794 | } |
2795 | ||
83aae4c7 | 2796 | static void |
72835c86 | 2797 | __mem_cgroup_commit_charge_swapin(struct page *page, struct mem_cgroup *memcg, |
83aae4c7 | 2798 | enum charge_type ctype) |
7a81b88c | 2799 | { |
f8d66542 | 2800 | if (mem_cgroup_disabled()) |
7a81b88c | 2801 | return; |
72835c86 | 2802 | if (!memcg) |
7a81b88c | 2803 | return; |
72835c86 | 2804 | cgroup_exclude_rmdir(&memcg->css); |
5a6475a4 | 2805 | |
ce587e65 | 2806 | __mem_cgroup_commit_charge(memcg, page, 1, ctype, true); |
8c7c6e34 KH |
2807 | /* |
2808 | * Now swap is on-memory. This means this page may be | |
2809 | * counted both as mem and swap....double count. | |
03f3c433 KH |
2810 | * Fix it by uncharging from memsw. Basically, this SwapCache is stable |
2811 | * under lock_page(). But in do_swap_page()::memory.c, reuse_swap_page() | |
2812 | * may call delete_from_swap_cache() before reach here. | |
8c7c6e34 | 2813 | */ |
03f3c433 | 2814 | if (do_swap_account && PageSwapCache(page)) { |
8c7c6e34 | 2815 | swp_entry_t ent = {.val = page_private(page)}; |
86493009 | 2816 | mem_cgroup_uncharge_swap(ent); |
8c7c6e34 | 2817 | } |
88703267 KH |
2818 | /* |
2819 | * At swapin, we may charge account against cgroup which has no tasks. | |
2820 | * So, rmdir()->pre_destroy() can be called while we do this charge. | |
2821 | * In that case, we need to call pre_destroy() again. check it here. | |
2822 | */ | |
72835c86 | 2823 | cgroup_release_and_wakeup_rmdir(&memcg->css); |
7a81b88c KH |
2824 | } |
2825 | ||
72835c86 JW |
2826 | void mem_cgroup_commit_charge_swapin(struct page *page, |
2827 | struct mem_cgroup *memcg) | |
83aae4c7 | 2828 | { |
72835c86 JW |
2829 | __mem_cgroup_commit_charge_swapin(page, memcg, |
2830 | MEM_CGROUP_CHARGE_TYPE_MAPPED); | |
83aae4c7 DN |
2831 | } |
2832 | ||
c0ff4b85 | 2833 | void mem_cgroup_cancel_charge_swapin(struct mem_cgroup *memcg) |
7a81b88c | 2834 | { |
f8d66542 | 2835 | if (mem_cgroup_disabled()) |
7a81b88c | 2836 | return; |
c0ff4b85 | 2837 | if (!memcg) |
7a81b88c | 2838 | return; |
c0ff4b85 | 2839 | __mem_cgroup_cancel_charge(memcg, 1); |
7a81b88c KH |
2840 | } |
2841 | ||
c0ff4b85 | 2842 | static void mem_cgroup_do_uncharge(struct mem_cgroup *memcg, |
7ec99d62 JW |
2843 | unsigned int nr_pages, |
2844 | const enum charge_type ctype) | |
569b846d KH |
2845 | { |
2846 | struct memcg_batch_info *batch = NULL; | |
2847 | bool uncharge_memsw = true; | |
7ec99d62 | 2848 | |
569b846d KH |
2849 | /* If swapout, usage of swap doesn't decrease */ |
2850 | if (!do_swap_account || ctype == MEM_CGROUP_CHARGE_TYPE_SWAPOUT) | |
2851 | uncharge_memsw = false; | |
569b846d KH |
2852 | |
2853 | batch = ¤t->memcg_batch; | |
2854 | /* | |
2855 | * In usual, we do css_get() when we remember memcg pointer. | |
2856 | * But in this case, we keep res->usage until end of a series of | |
2857 | * uncharges. Then, it's ok to ignore memcg's refcnt. | |
2858 | */ | |
2859 | if (!batch->memcg) | |
c0ff4b85 | 2860 | batch->memcg = memcg; |
3c11ecf4 KH |
2861 | /* |
2862 | * do_batch > 0 when unmapping pages or inode invalidate/truncate. | |
25985edc | 2863 | * In those cases, all pages freed continuously can be expected to be in |
3c11ecf4 KH |
2864 | * the same cgroup and we have chance to coalesce uncharges. |
2865 | * But we do uncharge one by one if this is killed by OOM(TIF_MEMDIE) | |
2866 | * because we want to do uncharge as soon as possible. | |
2867 | */ | |
2868 | ||
2869 | if (!batch->do_batch || test_thread_flag(TIF_MEMDIE)) | |
2870 | goto direct_uncharge; | |
2871 | ||
7ec99d62 | 2872 | if (nr_pages > 1) |
ec168510 AA |
2873 | goto direct_uncharge; |
2874 | ||
569b846d KH |
2875 | /* |
2876 | * In typical case, batch->memcg == mem. This means we can | |
2877 | * merge a series of uncharges to an uncharge of res_counter. | |
2878 | * If not, we uncharge res_counter ony by one. | |
2879 | */ | |
c0ff4b85 | 2880 | if (batch->memcg != memcg) |
569b846d KH |
2881 | goto direct_uncharge; |
2882 | /* remember freed charge and uncharge it later */ | |
7ffd4ca7 | 2883 | batch->nr_pages++; |
569b846d | 2884 | if (uncharge_memsw) |
7ffd4ca7 | 2885 | batch->memsw_nr_pages++; |
569b846d KH |
2886 | return; |
2887 | direct_uncharge: | |
c0ff4b85 | 2888 | res_counter_uncharge(&memcg->res, nr_pages * PAGE_SIZE); |
569b846d | 2889 | if (uncharge_memsw) |
c0ff4b85 R |
2890 | res_counter_uncharge(&memcg->memsw, nr_pages * PAGE_SIZE); |
2891 | if (unlikely(batch->memcg != memcg)) | |
2892 | memcg_oom_recover(memcg); | |
569b846d | 2893 | } |
7a81b88c | 2894 | |
8a9f3ccd | 2895 | /* |
69029cd5 | 2896 | * uncharge if !page_mapped(page) |
8a9f3ccd | 2897 | */ |
8c7c6e34 | 2898 | static struct mem_cgroup * |
69029cd5 | 2899 | __mem_cgroup_uncharge_common(struct page *page, enum charge_type ctype) |
8a9f3ccd | 2900 | { |
c0ff4b85 | 2901 | struct mem_cgroup *memcg = NULL; |
7ec99d62 JW |
2902 | unsigned int nr_pages = 1; |
2903 | struct page_cgroup *pc; | |
b2402857 | 2904 | bool anon; |
8a9f3ccd | 2905 | |
f8d66542 | 2906 | if (mem_cgroup_disabled()) |
8c7c6e34 | 2907 | return NULL; |
4077960e | 2908 | |
d13d1443 | 2909 | if (PageSwapCache(page)) |
8c7c6e34 | 2910 | return NULL; |
d13d1443 | 2911 | |
37c2ac78 | 2912 | if (PageTransHuge(page)) { |
7ec99d62 | 2913 | nr_pages <<= compound_order(page); |
37c2ac78 AA |
2914 | VM_BUG_ON(!PageTransHuge(page)); |
2915 | } | |
8697d331 | 2916 | /* |
3c541e14 | 2917 | * Check if our page_cgroup is valid |
8697d331 | 2918 | */ |
52d4b9ac | 2919 | pc = lookup_page_cgroup(page); |
cfa44946 | 2920 | if (unlikely(!PageCgroupUsed(pc))) |
8c7c6e34 | 2921 | return NULL; |
b9c565d5 | 2922 | |
52d4b9ac | 2923 | lock_page_cgroup(pc); |
d13d1443 | 2924 | |
c0ff4b85 | 2925 | memcg = pc->mem_cgroup; |
8c7c6e34 | 2926 | |
d13d1443 KH |
2927 | if (!PageCgroupUsed(pc)) |
2928 | goto unlock_out; | |
2929 | ||
b2402857 KH |
2930 | anon = PageAnon(page); |
2931 | ||
d13d1443 KH |
2932 | switch (ctype) { |
2933 | case MEM_CGROUP_CHARGE_TYPE_MAPPED: | |
2ff76f11 KH |
2934 | /* |
2935 | * Generally PageAnon tells if it's the anon statistics to be | |
2936 | * updated; but sometimes e.g. mem_cgroup_uncharge_page() is | |
2937 | * used before page reached the stage of being marked PageAnon. | |
2938 | */ | |
b2402857 KH |
2939 | anon = true; |
2940 | /* fallthrough */ | |
8a9478ca | 2941 | case MEM_CGROUP_CHARGE_TYPE_DROP: |
ac39cf8c AM |
2942 | /* See mem_cgroup_prepare_migration() */ |
2943 | if (page_mapped(page) || PageCgroupMigration(pc)) | |
d13d1443 KH |
2944 | goto unlock_out; |
2945 | break; | |
2946 | case MEM_CGROUP_CHARGE_TYPE_SWAPOUT: | |
2947 | if (!PageAnon(page)) { /* Shared memory */ | |
2948 | if (page->mapping && !page_is_file_cache(page)) | |
2949 | goto unlock_out; | |
2950 | } else if (page_mapped(page)) /* Anon */ | |
2951 | goto unlock_out; | |
2952 | break; | |
2953 | default: | |
2954 | break; | |
52d4b9ac | 2955 | } |
d13d1443 | 2956 | |
b2402857 | 2957 | mem_cgroup_charge_statistics(memcg, anon, -nr_pages); |
04046e1a | 2958 | |
52d4b9ac | 2959 | ClearPageCgroupUsed(pc); |
544122e5 KH |
2960 | /* |
2961 | * pc->mem_cgroup is not cleared here. It will be accessed when it's | |
2962 | * freed from LRU. This is safe because uncharged page is expected not | |
2963 | * to be reused (freed soon). Exception is SwapCache, it's handled by | |
2964 | * special functions. | |
2965 | */ | |
b9c565d5 | 2966 | |
52d4b9ac | 2967 | unlock_page_cgroup(pc); |
f75ca962 | 2968 | /* |
c0ff4b85 | 2969 | * even after unlock, we have memcg->res.usage here and this memcg |
f75ca962 KH |
2970 | * will never be freed. |
2971 | */ | |
c0ff4b85 | 2972 | memcg_check_events(memcg, page); |
f75ca962 | 2973 | if (do_swap_account && ctype == MEM_CGROUP_CHARGE_TYPE_SWAPOUT) { |
c0ff4b85 R |
2974 | mem_cgroup_swap_statistics(memcg, true); |
2975 | mem_cgroup_get(memcg); | |
f75ca962 | 2976 | } |
c0ff4b85 R |
2977 | if (!mem_cgroup_is_root(memcg)) |
2978 | mem_cgroup_do_uncharge(memcg, nr_pages, ctype); | |
6d12e2d8 | 2979 | |
c0ff4b85 | 2980 | return memcg; |
d13d1443 KH |
2981 | |
2982 | unlock_out: | |
2983 | unlock_page_cgroup(pc); | |
8c7c6e34 | 2984 | return NULL; |
3c541e14 BS |
2985 | } |
2986 | ||
69029cd5 KH |
2987 | void mem_cgroup_uncharge_page(struct page *page) |
2988 | { | |
52d4b9ac KH |
2989 | /* early check. */ |
2990 | if (page_mapped(page)) | |
2991 | return; | |
40f23a21 | 2992 | VM_BUG_ON(page->mapping && !PageAnon(page)); |
69029cd5 KH |
2993 | __mem_cgroup_uncharge_common(page, MEM_CGROUP_CHARGE_TYPE_MAPPED); |
2994 | } | |
2995 | ||
2996 | void mem_cgroup_uncharge_cache_page(struct page *page) | |
2997 | { | |
2998 | VM_BUG_ON(page_mapped(page)); | |
b7abea96 | 2999 | VM_BUG_ON(page->mapping); |
69029cd5 KH |
3000 | __mem_cgroup_uncharge_common(page, MEM_CGROUP_CHARGE_TYPE_CACHE); |
3001 | } | |
3002 | ||
569b846d KH |
3003 | /* |
3004 | * Batch_start/batch_end is called in unmap_page_range/invlidate/trucate. | |
3005 | * In that cases, pages are freed continuously and we can expect pages | |
3006 | * are in the same memcg. All these calls itself limits the number of | |
3007 | * pages freed at once, then uncharge_start/end() is called properly. | |
3008 | * This may be called prural(2) times in a context, | |
3009 | */ | |
3010 | ||
3011 | void mem_cgroup_uncharge_start(void) | |
3012 | { | |
3013 | current->memcg_batch.do_batch++; | |
3014 | /* We can do nest. */ | |
3015 | if (current->memcg_batch.do_batch == 1) { | |
3016 | current->memcg_batch.memcg = NULL; | |
7ffd4ca7 JW |
3017 | current->memcg_batch.nr_pages = 0; |
3018 | current->memcg_batch.memsw_nr_pages = 0; | |
569b846d KH |
3019 | } |
3020 | } | |
3021 | ||
3022 | void mem_cgroup_uncharge_end(void) | |
3023 | { | |
3024 | struct memcg_batch_info *batch = ¤t->memcg_batch; | |
3025 | ||
3026 | if (!batch->do_batch) | |
3027 | return; | |
3028 | ||
3029 | batch->do_batch--; | |
3030 | if (batch->do_batch) /* If stacked, do nothing. */ | |
3031 | return; | |
3032 | ||
3033 | if (!batch->memcg) | |
3034 | return; | |
3035 | /* | |
3036 | * This "batch->memcg" is valid without any css_get/put etc... | |
3037 | * bacause we hide charges behind us. | |
3038 | */ | |
7ffd4ca7 JW |
3039 | if (batch->nr_pages) |
3040 | res_counter_uncharge(&batch->memcg->res, | |
3041 | batch->nr_pages * PAGE_SIZE); | |
3042 | if (batch->memsw_nr_pages) | |
3043 | res_counter_uncharge(&batch->memcg->memsw, | |
3044 | batch->memsw_nr_pages * PAGE_SIZE); | |
3c11ecf4 | 3045 | memcg_oom_recover(batch->memcg); |
569b846d KH |
3046 | /* forget this pointer (for sanity check) */ |
3047 | batch->memcg = NULL; | |
3048 | } | |
3049 | ||
e767e056 | 3050 | #ifdef CONFIG_SWAP |
8c7c6e34 | 3051 | /* |
e767e056 | 3052 | * called after __delete_from_swap_cache() and drop "page" account. |
8c7c6e34 KH |
3053 | * memcg information is recorded to swap_cgroup of "ent" |
3054 | */ | |
8a9478ca KH |
3055 | void |
3056 | mem_cgroup_uncharge_swapcache(struct page *page, swp_entry_t ent, bool swapout) | |
8c7c6e34 KH |
3057 | { |
3058 | struct mem_cgroup *memcg; | |
8a9478ca KH |
3059 | int ctype = MEM_CGROUP_CHARGE_TYPE_SWAPOUT; |
3060 | ||
3061 | if (!swapout) /* this was a swap cache but the swap is unused ! */ | |
3062 | ctype = MEM_CGROUP_CHARGE_TYPE_DROP; | |
3063 | ||
3064 | memcg = __mem_cgroup_uncharge_common(page, ctype); | |
8c7c6e34 | 3065 | |
f75ca962 KH |
3066 | /* |
3067 | * record memcg information, if swapout && memcg != NULL, | |
3068 | * mem_cgroup_get() was called in uncharge(). | |
3069 | */ | |
3070 | if (do_swap_account && swapout && memcg) | |
a3b2d692 | 3071 | swap_cgroup_record(ent, css_id(&memcg->css)); |
8c7c6e34 | 3072 | } |
e767e056 | 3073 | #endif |
8c7c6e34 KH |
3074 | |
3075 | #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP | |
3076 | /* | |
3077 | * called from swap_entry_free(). remove record in swap_cgroup and | |
3078 | * uncharge "memsw" account. | |
3079 | */ | |
3080 | void mem_cgroup_uncharge_swap(swp_entry_t ent) | |
d13d1443 | 3081 | { |
8c7c6e34 | 3082 | struct mem_cgroup *memcg; |
a3b2d692 | 3083 | unsigned short id; |
8c7c6e34 KH |
3084 | |
3085 | if (!do_swap_account) | |
3086 | return; | |
3087 | ||
a3b2d692 KH |
3088 | id = swap_cgroup_record(ent, 0); |
3089 | rcu_read_lock(); | |
3090 | memcg = mem_cgroup_lookup(id); | |
8c7c6e34 | 3091 | if (memcg) { |
a3b2d692 KH |
3092 | /* |
3093 | * We uncharge this because swap is freed. | |
3094 | * This memcg can be obsolete one. We avoid calling css_tryget | |
3095 | */ | |
0c3e73e8 | 3096 | if (!mem_cgroup_is_root(memcg)) |
4e649152 | 3097 | res_counter_uncharge(&memcg->memsw, PAGE_SIZE); |
0c3e73e8 | 3098 | mem_cgroup_swap_statistics(memcg, false); |
8c7c6e34 KH |
3099 | mem_cgroup_put(memcg); |
3100 | } | |
a3b2d692 | 3101 | rcu_read_unlock(); |
d13d1443 | 3102 | } |
02491447 DN |
3103 | |
3104 | /** | |
3105 | * mem_cgroup_move_swap_account - move swap charge and swap_cgroup's record. | |
3106 | * @entry: swap entry to be moved | |
3107 | * @from: mem_cgroup which the entry is moved from | |
3108 | * @to: mem_cgroup which the entry is moved to | |
3109 | * | |
3110 | * It succeeds only when the swap_cgroup's record for this entry is the same | |
3111 | * as the mem_cgroup's id of @from. | |
3112 | * | |
3113 | * Returns 0 on success, -EINVAL on failure. | |
3114 | * | |
3115 | * The caller must have charged to @to, IOW, called res_counter_charge() about | |
3116 | * both res and memsw, and called css_get(). | |
3117 | */ | |
3118 | static int mem_cgroup_move_swap_account(swp_entry_t entry, | |
e91cbb42 | 3119 | struct mem_cgroup *from, struct mem_cgroup *to) |
02491447 DN |
3120 | { |
3121 | unsigned short old_id, new_id; | |
3122 | ||
3123 | old_id = css_id(&from->css); | |
3124 | new_id = css_id(&to->css); | |
3125 | ||
3126 | if (swap_cgroup_cmpxchg(entry, old_id, new_id) == old_id) { | |
02491447 | 3127 | mem_cgroup_swap_statistics(from, false); |
483c30b5 | 3128 | mem_cgroup_swap_statistics(to, true); |
02491447 | 3129 | /* |
483c30b5 DN |
3130 | * This function is only called from task migration context now. |
3131 | * It postpones res_counter and refcount handling till the end | |
3132 | * of task migration(mem_cgroup_clear_mc()) for performance | |
3133 | * improvement. But we cannot postpone mem_cgroup_get(to) | |
3134 | * because if the process that has been moved to @to does | |
3135 | * swap-in, the refcount of @to might be decreased to 0. | |
02491447 | 3136 | */ |
02491447 | 3137 | mem_cgroup_get(to); |
02491447 DN |
3138 | return 0; |
3139 | } | |
3140 | return -EINVAL; | |
3141 | } | |
3142 | #else | |
3143 | static inline int mem_cgroup_move_swap_account(swp_entry_t entry, | |
e91cbb42 | 3144 | struct mem_cgroup *from, struct mem_cgroup *to) |
02491447 DN |
3145 | { |
3146 | return -EINVAL; | |
3147 | } | |
8c7c6e34 | 3148 | #endif |
d13d1443 | 3149 | |
ae41be37 | 3150 | /* |
01b1ae63 KH |
3151 | * Before starting migration, account PAGE_SIZE to mem_cgroup that the old |
3152 | * page belongs to. | |
ae41be37 | 3153 | */ |
ac39cf8c | 3154 | int mem_cgroup_prepare_migration(struct page *page, |
72835c86 | 3155 | struct page *newpage, struct mem_cgroup **memcgp, gfp_t gfp_mask) |
ae41be37 | 3156 | { |
c0ff4b85 | 3157 | struct mem_cgroup *memcg = NULL; |
7ec99d62 | 3158 | struct page_cgroup *pc; |
ac39cf8c | 3159 | enum charge_type ctype; |
e8589cc1 | 3160 | int ret = 0; |
8869b8f6 | 3161 | |
72835c86 | 3162 | *memcgp = NULL; |
56039efa | 3163 | |
ec168510 | 3164 | VM_BUG_ON(PageTransHuge(page)); |
f8d66542 | 3165 | if (mem_cgroup_disabled()) |
4077960e BS |
3166 | return 0; |
3167 | ||
52d4b9ac KH |
3168 | pc = lookup_page_cgroup(page); |
3169 | lock_page_cgroup(pc); | |
3170 | if (PageCgroupUsed(pc)) { | |
c0ff4b85 R |
3171 | memcg = pc->mem_cgroup; |
3172 | css_get(&memcg->css); | |
ac39cf8c AM |
3173 | /* |
3174 | * At migrating an anonymous page, its mapcount goes down | |
3175 | * to 0 and uncharge() will be called. But, even if it's fully | |
3176 | * unmapped, migration may fail and this page has to be | |
3177 | * charged again. We set MIGRATION flag here and delay uncharge | |
3178 | * until end_migration() is called | |
3179 | * | |
3180 | * Corner Case Thinking | |
3181 | * A) | |
3182 | * When the old page was mapped as Anon and it's unmap-and-freed | |
3183 | * while migration was ongoing. | |
3184 | * If unmap finds the old page, uncharge() of it will be delayed | |
3185 | * until end_migration(). If unmap finds a new page, it's | |
3186 | * uncharged when it make mapcount to be 1->0. If unmap code | |
3187 | * finds swap_migration_entry, the new page will not be mapped | |
3188 | * and end_migration() will find it(mapcount==0). | |
3189 | * | |
3190 | * B) | |
3191 | * When the old page was mapped but migraion fails, the kernel | |
3192 | * remaps it. A charge for it is kept by MIGRATION flag even | |
3193 | * if mapcount goes down to 0. We can do remap successfully | |
3194 | * without charging it again. | |
3195 | * | |
3196 | * C) | |
3197 | * The "old" page is under lock_page() until the end of | |
3198 | * migration, so, the old page itself will not be swapped-out. | |
3199 | * If the new page is swapped out before end_migraton, our | |
3200 | * hook to usual swap-out path will catch the event. | |
3201 | */ | |
3202 | if (PageAnon(page)) | |
3203 | SetPageCgroupMigration(pc); | |
e8589cc1 | 3204 | } |
52d4b9ac | 3205 | unlock_page_cgroup(pc); |
ac39cf8c AM |
3206 | /* |
3207 | * If the page is not charged at this point, | |
3208 | * we return here. | |
3209 | */ | |
c0ff4b85 | 3210 | if (!memcg) |
ac39cf8c | 3211 | return 0; |
01b1ae63 | 3212 | |
72835c86 JW |
3213 | *memcgp = memcg; |
3214 | ret = __mem_cgroup_try_charge(NULL, gfp_mask, 1, memcgp, false); | |
c0ff4b85 | 3215 | css_put(&memcg->css);/* drop extra refcnt */ |
38c5d72f | 3216 | if (ret) { |
ac39cf8c AM |
3217 | if (PageAnon(page)) { |
3218 | lock_page_cgroup(pc); | |
3219 | ClearPageCgroupMigration(pc); | |
3220 | unlock_page_cgroup(pc); | |
3221 | /* | |
3222 | * The old page may be fully unmapped while we kept it. | |
3223 | */ | |
3224 | mem_cgroup_uncharge_page(page); | |
3225 | } | |
38c5d72f | 3226 | /* we'll need to revisit this error code (we have -EINTR) */ |
ac39cf8c | 3227 | return -ENOMEM; |
e8589cc1 | 3228 | } |
ac39cf8c AM |
3229 | /* |
3230 | * We charge new page before it's used/mapped. So, even if unlock_page() | |
3231 | * is called before end_migration, we can catch all events on this new | |
3232 | * page. In the case new page is migrated but not remapped, new page's | |
3233 | * mapcount will be finally 0 and we call uncharge in end_migration(). | |
3234 | */ | |
ac39cf8c AM |
3235 | if (PageAnon(page)) |
3236 | ctype = MEM_CGROUP_CHARGE_TYPE_MAPPED; | |
3237 | else if (page_is_file_cache(page)) | |
3238 | ctype = MEM_CGROUP_CHARGE_TYPE_CACHE; | |
3239 | else | |
3240 | ctype = MEM_CGROUP_CHARGE_TYPE_SHMEM; | |
ce587e65 | 3241 | __mem_cgroup_commit_charge(memcg, newpage, 1, ctype, false); |
e8589cc1 | 3242 | return ret; |
ae41be37 | 3243 | } |
8869b8f6 | 3244 | |
69029cd5 | 3245 | /* remove redundant charge if migration failed*/ |
c0ff4b85 | 3246 | void mem_cgroup_end_migration(struct mem_cgroup *memcg, |
50de1dd9 | 3247 | struct page *oldpage, struct page *newpage, bool migration_ok) |
ae41be37 | 3248 | { |
ac39cf8c | 3249 | struct page *used, *unused; |
01b1ae63 | 3250 | struct page_cgroup *pc; |
b2402857 | 3251 | bool anon; |
01b1ae63 | 3252 | |
c0ff4b85 | 3253 | if (!memcg) |
01b1ae63 | 3254 | return; |
ac39cf8c | 3255 | /* blocks rmdir() */ |
c0ff4b85 | 3256 | cgroup_exclude_rmdir(&memcg->css); |
50de1dd9 | 3257 | if (!migration_ok) { |
ac39cf8c AM |
3258 | used = oldpage; |
3259 | unused = newpage; | |
01b1ae63 | 3260 | } else { |
ac39cf8c | 3261 | used = newpage; |
01b1ae63 KH |
3262 | unused = oldpage; |
3263 | } | |
69029cd5 | 3264 | /* |
ac39cf8c AM |
3265 | * We disallowed uncharge of pages under migration because mapcount |
3266 | * of the page goes down to zero, temporarly. | |
3267 | * Clear the flag and check the page should be charged. | |
01b1ae63 | 3268 | */ |
ac39cf8c AM |
3269 | pc = lookup_page_cgroup(oldpage); |
3270 | lock_page_cgroup(pc); | |
3271 | ClearPageCgroupMigration(pc); | |
3272 | unlock_page_cgroup(pc); | |
b2402857 KH |
3273 | anon = PageAnon(used); |
3274 | __mem_cgroup_uncharge_common(unused, | |
3275 | anon ? MEM_CGROUP_CHARGE_TYPE_MAPPED | |
3276 | : MEM_CGROUP_CHARGE_TYPE_CACHE); | |
ac39cf8c | 3277 | |
01b1ae63 | 3278 | /* |
ac39cf8c AM |
3279 | * If a page is a file cache, radix-tree replacement is very atomic |
3280 | * and we can skip this check. When it was an Anon page, its mapcount | |
3281 | * goes down to 0. But because we added MIGRATION flage, it's not | |
3282 | * uncharged yet. There are several case but page->mapcount check | |
3283 | * and USED bit check in mem_cgroup_uncharge_page() will do enough | |
3284 | * check. (see prepare_charge() also) | |
69029cd5 | 3285 | */ |
b2402857 | 3286 | if (anon) |
ac39cf8c | 3287 | mem_cgroup_uncharge_page(used); |
88703267 | 3288 | /* |
ac39cf8c AM |
3289 | * At migration, we may charge account against cgroup which has no |
3290 | * tasks. | |
88703267 KH |
3291 | * So, rmdir()->pre_destroy() can be called while we do this charge. |
3292 | * In that case, we need to call pre_destroy() again. check it here. | |
3293 | */ | |
c0ff4b85 | 3294 | cgroup_release_and_wakeup_rmdir(&memcg->css); |
ae41be37 | 3295 | } |
78fb7466 | 3296 | |
ab936cbc KH |
3297 | /* |
3298 | * At replace page cache, newpage is not under any memcg but it's on | |
3299 | * LRU. So, this function doesn't touch res_counter but handles LRU | |
3300 | * in correct way. Both pages are locked so we cannot race with uncharge. | |
3301 | */ | |
3302 | void mem_cgroup_replace_page_cache(struct page *oldpage, | |
3303 | struct page *newpage) | |
3304 | { | |
bde05d1c | 3305 | struct mem_cgroup *memcg = NULL; |
ab936cbc | 3306 | struct page_cgroup *pc; |
ab936cbc | 3307 | enum charge_type type = MEM_CGROUP_CHARGE_TYPE_CACHE; |
ab936cbc KH |
3308 | |
3309 | if (mem_cgroup_disabled()) | |
3310 | return; | |
3311 | ||
3312 | pc = lookup_page_cgroup(oldpage); | |
3313 | /* fix accounting on old pages */ | |
3314 | lock_page_cgroup(pc); | |
bde05d1c HD |
3315 | if (PageCgroupUsed(pc)) { |
3316 | memcg = pc->mem_cgroup; | |
3317 | mem_cgroup_charge_statistics(memcg, false, -1); | |
3318 | ClearPageCgroupUsed(pc); | |
3319 | } | |
ab936cbc KH |
3320 | unlock_page_cgroup(pc); |
3321 | ||
bde05d1c HD |
3322 | /* |
3323 | * When called from shmem_replace_page(), in some cases the | |
3324 | * oldpage has already been charged, and in some cases not. | |
3325 | */ | |
3326 | if (!memcg) | |
3327 | return; | |
3328 | ||
ab936cbc KH |
3329 | if (PageSwapBacked(oldpage)) |
3330 | type = MEM_CGROUP_CHARGE_TYPE_SHMEM; | |
3331 | ||
ab936cbc KH |
3332 | /* |
3333 | * Even if newpage->mapping was NULL before starting replacement, | |
3334 | * the newpage may be on LRU(or pagevec for LRU) already. We lock | |
3335 | * LRU while we overwrite pc->mem_cgroup. | |
3336 | */ | |
ce587e65 | 3337 | __mem_cgroup_commit_charge(memcg, newpage, 1, type, true); |
ab936cbc KH |
3338 | } |
3339 | ||
f212ad7c DN |
3340 | #ifdef CONFIG_DEBUG_VM |
3341 | static struct page_cgroup *lookup_page_cgroup_used(struct page *page) | |
3342 | { | |
3343 | struct page_cgroup *pc; | |
3344 | ||
3345 | pc = lookup_page_cgroup(page); | |
cfa44946 JW |
3346 | /* |
3347 | * Can be NULL while feeding pages into the page allocator for | |
3348 | * the first time, i.e. during boot or memory hotplug; | |
3349 | * or when mem_cgroup_disabled(). | |
3350 | */ | |
f212ad7c DN |
3351 | if (likely(pc) && PageCgroupUsed(pc)) |
3352 | return pc; | |
3353 | return NULL; | |
3354 | } | |
3355 | ||
3356 | bool mem_cgroup_bad_page_check(struct page *page) | |
3357 | { | |
3358 | if (mem_cgroup_disabled()) | |
3359 | return false; | |
3360 | ||
3361 | return lookup_page_cgroup_used(page) != NULL; | |
3362 | } | |
3363 | ||
3364 | void mem_cgroup_print_bad_page(struct page *page) | |
3365 | { | |
3366 | struct page_cgroup *pc; | |
3367 | ||
3368 | pc = lookup_page_cgroup_used(page); | |
3369 | if (pc) { | |
90b3feae | 3370 | printk(KERN_ALERT "pc:%p pc->flags:%lx pc->mem_cgroup:%p\n", |
f212ad7c | 3371 | pc, pc->flags, pc->mem_cgroup); |
f212ad7c DN |
3372 | } |
3373 | } | |
3374 | #endif | |
3375 | ||
8c7c6e34 KH |
3376 | static DEFINE_MUTEX(set_limit_mutex); |
3377 | ||
d38d2a75 | 3378 | static int mem_cgroup_resize_limit(struct mem_cgroup *memcg, |
8c7c6e34 | 3379 | unsigned long long val) |
628f4235 | 3380 | { |
81d39c20 | 3381 | int retry_count; |
3c11ecf4 | 3382 | u64 memswlimit, memlimit; |
628f4235 | 3383 | int ret = 0; |
81d39c20 KH |
3384 | int children = mem_cgroup_count_children(memcg); |
3385 | u64 curusage, oldusage; | |
3c11ecf4 | 3386 | int enlarge; |
81d39c20 KH |
3387 | |
3388 | /* | |
3389 | * For keeping hierarchical_reclaim simple, how long we should retry | |
3390 | * is depends on callers. We set our retry-count to be function | |
3391 | * of # of children which we should visit in this loop. | |
3392 | */ | |
3393 | retry_count = MEM_CGROUP_RECLAIM_RETRIES * children; | |
3394 | ||
3395 | oldusage = res_counter_read_u64(&memcg->res, RES_USAGE); | |
628f4235 | 3396 | |
3c11ecf4 | 3397 | enlarge = 0; |
8c7c6e34 | 3398 | while (retry_count) { |
628f4235 KH |
3399 | if (signal_pending(current)) { |
3400 | ret = -EINTR; | |
3401 | break; | |
3402 | } | |
8c7c6e34 KH |
3403 | /* |
3404 | * Rather than hide all in some function, I do this in | |
3405 | * open coded manner. You see what this really does. | |
c0ff4b85 | 3406 | * We have to guarantee memcg->res.limit < memcg->memsw.limit. |
8c7c6e34 KH |
3407 | */ |
3408 | mutex_lock(&set_limit_mutex); | |
3409 | memswlimit = res_counter_read_u64(&memcg->memsw, RES_LIMIT); | |
3410 | if (memswlimit < val) { | |
3411 | ret = -EINVAL; | |
3412 | mutex_unlock(&set_limit_mutex); | |
628f4235 KH |
3413 | break; |
3414 | } | |
3c11ecf4 KH |
3415 | |
3416 | memlimit = res_counter_read_u64(&memcg->res, RES_LIMIT); | |
3417 | if (memlimit < val) | |
3418 | enlarge = 1; | |
3419 | ||
8c7c6e34 | 3420 | ret = res_counter_set_limit(&memcg->res, val); |
22a668d7 KH |
3421 | if (!ret) { |
3422 | if (memswlimit == val) | |
3423 | memcg->memsw_is_minimum = true; | |
3424 | else | |
3425 | memcg->memsw_is_minimum = false; | |
3426 | } | |
8c7c6e34 KH |
3427 | mutex_unlock(&set_limit_mutex); |
3428 | ||
3429 | if (!ret) | |
3430 | break; | |
3431 | ||
5660048c JW |
3432 | mem_cgroup_reclaim(memcg, GFP_KERNEL, |
3433 | MEM_CGROUP_RECLAIM_SHRINK); | |
81d39c20 KH |
3434 | curusage = res_counter_read_u64(&memcg->res, RES_USAGE); |
3435 | /* Usage is reduced ? */ | |
3436 | if (curusage >= oldusage) | |
3437 | retry_count--; | |
3438 | else | |
3439 | oldusage = curusage; | |
8c7c6e34 | 3440 | } |
3c11ecf4 KH |
3441 | if (!ret && enlarge) |
3442 | memcg_oom_recover(memcg); | |
14797e23 | 3443 | |
8c7c6e34 KH |
3444 | return ret; |
3445 | } | |
3446 | ||
338c8431 LZ |
3447 | static int mem_cgroup_resize_memsw_limit(struct mem_cgroup *memcg, |
3448 | unsigned long long val) | |
8c7c6e34 | 3449 | { |
81d39c20 | 3450 | int retry_count; |
3c11ecf4 | 3451 | u64 memlimit, memswlimit, oldusage, curusage; |
81d39c20 KH |
3452 | int children = mem_cgroup_count_children(memcg); |
3453 | int ret = -EBUSY; | |
3c11ecf4 | 3454 | int enlarge = 0; |
8c7c6e34 | 3455 | |
81d39c20 KH |
3456 | /* see mem_cgroup_resize_res_limit */ |
3457 | retry_count = children * MEM_CGROUP_RECLAIM_RETRIES; | |
3458 | oldusage = res_counter_read_u64(&memcg->memsw, RES_USAGE); | |
8c7c6e34 KH |
3459 | while (retry_count) { |
3460 | if (signal_pending(current)) { | |
3461 | ret = -EINTR; | |
3462 | break; | |
3463 | } | |
3464 | /* | |
3465 | * Rather than hide all in some function, I do this in | |
3466 | * open coded manner. You see what this really does. | |
c0ff4b85 | 3467 | * We have to guarantee memcg->res.limit < memcg->memsw.limit. |
8c7c6e34 KH |
3468 | */ |
3469 | mutex_lock(&set_limit_mutex); | |
3470 | memlimit = res_counter_read_u64(&memcg->res, RES_LIMIT); | |
3471 | if (memlimit > val) { | |
3472 | ret = -EINVAL; | |
3473 | mutex_unlock(&set_limit_mutex); | |
3474 | break; | |
3475 | } | |
3c11ecf4 KH |
3476 | memswlimit = res_counter_read_u64(&memcg->memsw, RES_LIMIT); |
3477 | if (memswlimit < val) | |
3478 | enlarge = 1; | |
8c7c6e34 | 3479 | ret = res_counter_set_limit(&memcg->memsw, val); |
22a668d7 KH |
3480 | if (!ret) { |
3481 | if (memlimit == val) | |
3482 | memcg->memsw_is_minimum = true; | |
3483 | else | |
3484 | memcg->memsw_is_minimum = false; | |
3485 | } | |
8c7c6e34 KH |
3486 | mutex_unlock(&set_limit_mutex); |
3487 | ||
3488 | if (!ret) | |
3489 | break; | |
3490 | ||
5660048c JW |
3491 | mem_cgroup_reclaim(memcg, GFP_KERNEL, |
3492 | MEM_CGROUP_RECLAIM_NOSWAP | | |
3493 | MEM_CGROUP_RECLAIM_SHRINK); | |
8c7c6e34 | 3494 | curusage = res_counter_read_u64(&memcg->memsw, RES_USAGE); |
81d39c20 | 3495 | /* Usage is reduced ? */ |
8c7c6e34 | 3496 | if (curusage >= oldusage) |
628f4235 | 3497 | retry_count--; |
81d39c20 KH |
3498 | else |
3499 | oldusage = curusage; | |
628f4235 | 3500 | } |
3c11ecf4 KH |
3501 | if (!ret && enlarge) |
3502 | memcg_oom_recover(memcg); | |
628f4235 KH |
3503 | return ret; |
3504 | } | |
3505 | ||
4e416953 | 3506 | unsigned long mem_cgroup_soft_limit_reclaim(struct zone *zone, int order, |
0ae5e89c YH |
3507 | gfp_t gfp_mask, |
3508 | unsigned long *total_scanned) | |
4e416953 BS |
3509 | { |
3510 | unsigned long nr_reclaimed = 0; | |
3511 | struct mem_cgroup_per_zone *mz, *next_mz = NULL; | |
3512 | unsigned long reclaimed; | |
3513 | int loop = 0; | |
3514 | struct mem_cgroup_tree_per_zone *mctz; | |
ef8745c1 | 3515 | unsigned long long excess; |
0ae5e89c | 3516 | unsigned long nr_scanned; |
4e416953 BS |
3517 | |
3518 | if (order > 0) | |
3519 | return 0; | |
3520 | ||
00918b6a | 3521 | mctz = soft_limit_tree_node_zone(zone_to_nid(zone), zone_idx(zone)); |
4e416953 BS |
3522 | /* |
3523 | * This loop can run a while, specially if mem_cgroup's continuously | |
3524 | * keep exceeding their soft limit and putting the system under | |
3525 | * pressure | |
3526 | */ | |
3527 | do { | |
3528 | if (next_mz) | |
3529 | mz = next_mz; | |
3530 | else | |
3531 | mz = mem_cgroup_largest_soft_limit_node(mctz); | |
3532 | if (!mz) | |
3533 | break; | |
3534 | ||
0ae5e89c | 3535 | nr_scanned = 0; |
d79154bb | 3536 | reclaimed = mem_cgroup_soft_reclaim(mz->memcg, zone, |
5660048c | 3537 | gfp_mask, &nr_scanned); |
4e416953 | 3538 | nr_reclaimed += reclaimed; |
0ae5e89c | 3539 | *total_scanned += nr_scanned; |
4e416953 BS |
3540 | spin_lock(&mctz->lock); |
3541 | ||
3542 | /* | |
3543 | * If we failed to reclaim anything from this memory cgroup | |
3544 | * it is time to move on to the next cgroup | |
3545 | */ | |
3546 | next_mz = NULL; | |
3547 | if (!reclaimed) { | |
3548 | do { | |
3549 | /* | |
3550 | * Loop until we find yet another one. | |
3551 | * | |
3552 | * By the time we get the soft_limit lock | |
3553 | * again, someone might have aded the | |
3554 | * group back on the RB tree. Iterate to | |
3555 | * make sure we get a different mem. | |
3556 | * mem_cgroup_largest_soft_limit_node returns | |
3557 | * NULL if no other cgroup is present on | |
3558 | * the tree | |
3559 | */ | |
3560 | next_mz = | |
3561 | __mem_cgroup_largest_soft_limit_node(mctz); | |
39cc98f1 | 3562 | if (next_mz == mz) |
d79154bb | 3563 | css_put(&next_mz->memcg->css); |
39cc98f1 | 3564 | else /* next_mz == NULL or other memcg */ |
4e416953 BS |
3565 | break; |
3566 | } while (1); | |
3567 | } | |
d79154bb HD |
3568 | __mem_cgroup_remove_exceeded(mz->memcg, mz, mctz); |
3569 | excess = res_counter_soft_limit_excess(&mz->memcg->res); | |
4e416953 BS |
3570 | /* |
3571 | * One school of thought says that we should not add | |
3572 | * back the node to the tree if reclaim returns 0. | |
3573 | * But our reclaim could return 0, simply because due | |
3574 | * to priority we are exposing a smaller subset of | |
3575 | * memory to reclaim from. Consider this as a longer | |
3576 | * term TODO. | |
3577 | */ | |
ef8745c1 | 3578 | /* If excess == 0, no tree ops */ |
d79154bb | 3579 | __mem_cgroup_insert_exceeded(mz->memcg, mz, mctz, excess); |
4e416953 | 3580 | spin_unlock(&mctz->lock); |
d79154bb | 3581 | css_put(&mz->memcg->css); |
4e416953 BS |
3582 | loop++; |
3583 | /* | |
3584 | * Could not reclaim anything and there are no more | |
3585 | * mem cgroups to try or we seem to be looping without | |
3586 | * reclaiming anything. | |
3587 | */ | |
3588 | if (!nr_reclaimed && | |
3589 | (next_mz == NULL || | |
3590 | loop > MEM_CGROUP_MAX_SOFT_LIMIT_RECLAIM_LOOPS)) | |
3591 | break; | |
3592 | } while (!nr_reclaimed); | |
3593 | if (next_mz) | |
d79154bb | 3594 | css_put(&next_mz->memcg->css); |
4e416953 BS |
3595 | return nr_reclaimed; |
3596 | } | |
3597 | ||
cc847582 KH |
3598 | /* |
3599 | * This routine traverse page_cgroup in given list and drop them all. | |
cc847582 KH |
3600 | * *And* this routine doesn't reclaim page itself, just removes page_cgroup. |
3601 | */ | |
c0ff4b85 | 3602 | static int mem_cgroup_force_empty_list(struct mem_cgroup *memcg, |
08e552c6 | 3603 | int node, int zid, enum lru_list lru) |
cc847582 | 3604 | { |
08e552c6 | 3605 | struct mem_cgroup_per_zone *mz; |
08e552c6 | 3606 | unsigned long flags, loop; |
072c56c1 | 3607 | struct list_head *list; |
925b7673 JW |
3608 | struct page *busy; |
3609 | struct zone *zone; | |
f817ed48 | 3610 | int ret = 0; |
072c56c1 | 3611 | |
08e552c6 | 3612 | zone = &NODE_DATA(node)->node_zones[zid]; |
c0ff4b85 | 3613 | mz = mem_cgroup_zoneinfo(memcg, node, zid); |
6290df54 | 3614 | list = &mz->lruvec.lists[lru]; |
cc847582 | 3615 | |
1eb49272 | 3616 | loop = mz->lru_size[lru]; |
f817ed48 KH |
3617 | /* give some margin against EBUSY etc...*/ |
3618 | loop += 256; | |
3619 | busy = NULL; | |
3620 | while (loop--) { | |
925b7673 | 3621 | struct page_cgroup *pc; |
5564e88b JW |
3622 | struct page *page; |
3623 | ||
f817ed48 | 3624 | ret = 0; |
08e552c6 | 3625 | spin_lock_irqsave(&zone->lru_lock, flags); |
f817ed48 | 3626 | if (list_empty(list)) { |
08e552c6 | 3627 | spin_unlock_irqrestore(&zone->lru_lock, flags); |
52d4b9ac | 3628 | break; |
f817ed48 | 3629 | } |
925b7673 JW |
3630 | page = list_entry(list->prev, struct page, lru); |
3631 | if (busy == page) { | |
3632 | list_move(&page->lru, list); | |
648bcc77 | 3633 | busy = NULL; |
08e552c6 | 3634 | spin_unlock_irqrestore(&zone->lru_lock, flags); |
f817ed48 KH |
3635 | continue; |
3636 | } | |
08e552c6 | 3637 | spin_unlock_irqrestore(&zone->lru_lock, flags); |
f817ed48 | 3638 | |
925b7673 | 3639 | pc = lookup_page_cgroup(page); |
5564e88b | 3640 | |
c0ff4b85 | 3641 | ret = mem_cgroup_move_parent(page, pc, memcg, GFP_KERNEL); |
38c5d72f | 3642 | if (ret == -ENOMEM || ret == -EINTR) |
52d4b9ac | 3643 | break; |
f817ed48 KH |
3644 | |
3645 | if (ret == -EBUSY || ret == -EINVAL) { | |
3646 | /* found lock contention or "pc" is obsolete. */ | |
925b7673 | 3647 | busy = page; |
f817ed48 KH |
3648 | cond_resched(); |
3649 | } else | |
3650 | busy = NULL; | |
cc847582 | 3651 | } |
08e552c6 | 3652 | |
f817ed48 KH |
3653 | if (!ret && !list_empty(list)) |
3654 | return -EBUSY; | |
3655 | return ret; | |
cc847582 KH |
3656 | } |
3657 | ||
3658 | /* | |
3659 | * make mem_cgroup's charge to be 0 if there is no task. | |
3660 | * This enables deleting this mem_cgroup. | |
3661 | */ | |
c0ff4b85 | 3662 | static int mem_cgroup_force_empty(struct mem_cgroup *memcg, bool free_all) |
cc847582 | 3663 | { |
f817ed48 KH |
3664 | int ret; |
3665 | int node, zid, shrink; | |
3666 | int nr_retries = MEM_CGROUP_RECLAIM_RETRIES; | |
c0ff4b85 | 3667 | struct cgroup *cgrp = memcg->css.cgroup; |
8869b8f6 | 3668 | |
c0ff4b85 | 3669 | css_get(&memcg->css); |
f817ed48 KH |
3670 | |
3671 | shrink = 0; | |
c1e862c1 KH |
3672 | /* should free all ? */ |
3673 | if (free_all) | |
3674 | goto try_to_free; | |
f817ed48 | 3675 | move_account: |
fce66477 | 3676 | do { |
f817ed48 | 3677 | ret = -EBUSY; |
c1e862c1 KH |
3678 | if (cgroup_task_count(cgrp) || !list_empty(&cgrp->children)) |
3679 | goto out; | |
3680 | ret = -EINTR; | |
3681 | if (signal_pending(current)) | |
cc847582 | 3682 | goto out; |
52d4b9ac KH |
3683 | /* This is for making all *used* pages to be on LRU. */ |
3684 | lru_add_drain_all(); | |
c0ff4b85 | 3685 | drain_all_stock_sync(memcg); |
f817ed48 | 3686 | ret = 0; |
c0ff4b85 | 3687 | mem_cgroup_start_move(memcg); |
299b4eaa | 3688 | for_each_node_state(node, N_HIGH_MEMORY) { |
f817ed48 | 3689 | for (zid = 0; !ret && zid < MAX_NR_ZONES; zid++) { |
f156ab93 HD |
3690 | enum lru_list lru; |
3691 | for_each_lru(lru) { | |
c0ff4b85 | 3692 | ret = mem_cgroup_force_empty_list(memcg, |
f156ab93 | 3693 | node, zid, lru); |
f817ed48 KH |
3694 | if (ret) |
3695 | break; | |
3696 | } | |
1ecaab2b | 3697 | } |
f817ed48 KH |
3698 | if (ret) |
3699 | break; | |
3700 | } | |
c0ff4b85 R |
3701 | mem_cgroup_end_move(memcg); |
3702 | memcg_oom_recover(memcg); | |
f817ed48 KH |
3703 | /* it seems parent cgroup doesn't have enough mem */ |
3704 | if (ret == -ENOMEM) | |
3705 | goto try_to_free; | |
52d4b9ac | 3706 | cond_resched(); |
fce66477 | 3707 | /* "ret" should also be checked to ensure all lists are empty. */ |
569530fb | 3708 | } while (res_counter_read_u64(&memcg->res, RES_USAGE) > 0 || ret); |
cc847582 | 3709 | out: |
c0ff4b85 | 3710 | css_put(&memcg->css); |
cc847582 | 3711 | return ret; |
f817ed48 KH |
3712 | |
3713 | try_to_free: | |
c1e862c1 KH |
3714 | /* returns EBUSY if there is a task or if we come here twice. */ |
3715 | if (cgroup_task_count(cgrp) || !list_empty(&cgrp->children) || shrink) { | |
f817ed48 KH |
3716 | ret = -EBUSY; |
3717 | goto out; | |
3718 | } | |
c1e862c1 KH |
3719 | /* we call try-to-free pages for make this cgroup empty */ |
3720 | lru_add_drain_all(); | |
f817ed48 KH |
3721 | /* try to free all pages in this cgroup */ |
3722 | shrink = 1; | |
569530fb | 3723 | while (nr_retries && res_counter_read_u64(&memcg->res, RES_USAGE) > 0) { |
f817ed48 | 3724 | int progress; |
c1e862c1 KH |
3725 | |
3726 | if (signal_pending(current)) { | |
3727 | ret = -EINTR; | |
3728 | goto out; | |
3729 | } | |
c0ff4b85 | 3730 | progress = try_to_free_mem_cgroup_pages(memcg, GFP_KERNEL, |
185efc0f | 3731 | false); |
c1e862c1 | 3732 | if (!progress) { |
f817ed48 | 3733 | nr_retries--; |
c1e862c1 | 3734 | /* maybe some writeback is necessary */ |
8aa7e847 | 3735 | congestion_wait(BLK_RW_ASYNC, HZ/10); |
c1e862c1 | 3736 | } |
f817ed48 KH |
3737 | |
3738 | } | |
08e552c6 | 3739 | lru_add_drain(); |
f817ed48 | 3740 | /* try move_account...there may be some *locked* pages. */ |
fce66477 | 3741 | goto move_account; |
cc847582 KH |
3742 | } |
3743 | ||
6bbda35c | 3744 | static int mem_cgroup_force_empty_write(struct cgroup *cont, unsigned int event) |
c1e862c1 KH |
3745 | { |
3746 | return mem_cgroup_force_empty(mem_cgroup_from_cont(cont), true); | |
3747 | } | |
3748 | ||
3749 | ||
18f59ea7 BS |
3750 | static u64 mem_cgroup_hierarchy_read(struct cgroup *cont, struct cftype *cft) |
3751 | { | |
3752 | return mem_cgroup_from_cont(cont)->use_hierarchy; | |
3753 | } | |
3754 | ||
3755 | static int mem_cgroup_hierarchy_write(struct cgroup *cont, struct cftype *cft, | |
3756 | u64 val) | |
3757 | { | |
3758 | int retval = 0; | |
c0ff4b85 | 3759 | struct mem_cgroup *memcg = mem_cgroup_from_cont(cont); |
18f59ea7 | 3760 | struct cgroup *parent = cont->parent; |
c0ff4b85 | 3761 | struct mem_cgroup *parent_memcg = NULL; |
18f59ea7 BS |
3762 | |
3763 | if (parent) | |
c0ff4b85 | 3764 | parent_memcg = mem_cgroup_from_cont(parent); |
18f59ea7 BS |
3765 | |
3766 | cgroup_lock(); | |
3767 | /* | |
af901ca1 | 3768 | * If parent's use_hierarchy is set, we can't make any modifications |
18f59ea7 BS |
3769 | * in the child subtrees. If it is unset, then the change can |
3770 | * occur, provided the current cgroup has no children. | |
3771 | * | |
3772 | * For the root cgroup, parent_mem is NULL, we allow value to be | |
3773 | * set if there are no children. | |
3774 | */ | |
c0ff4b85 | 3775 | if ((!parent_memcg || !parent_memcg->use_hierarchy) && |
18f59ea7 BS |
3776 | (val == 1 || val == 0)) { |
3777 | if (list_empty(&cont->children)) | |
c0ff4b85 | 3778 | memcg->use_hierarchy = val; |
18f59ea7 BS |
3779 | else |
3780 | retval = -EBUSY; | |
3781 | } else | |
3782 | retval = -EINVAL; | |
3783 | cgroup_unlock(); | |
3784 | ||
3785 | return retval; | |
3786 | } | |
3787 | ||
0c3e73e8 | 3788 | |
c0ff4b85 | 3789 | static unsigned long mem_cgroup_recursive_stat(struct mem_cgroup *memcg, |
7a159cc9 | 3790 | enum mem_cgroup_stat_index idx) |
0c3e73e8 | 3791 | { |
7d74b06f | 3792 | struct mem_cgroup *iter; |
7a159cc9 | 3793 | long val = 0; |
0c3e73e8 | 3794 | |
7a159cc9 | 3795 | /* Per-cpu values can be negative, use a signed accumulator */ |
c0ff4b85 | 3796 | for_each_mem_cgroup_tree(iter, memcg) |
7d74b06f KH |
3797 | val += mem_cgroup_read_stat(iter, idx); |
3798 | ||
3799 | if (val < 0) /* race ? */ | |
3800 | val = 0; | |
3801 | return val; | |
0c3e73e8 BS |
3802 | } |
3803 | ||
c0ff4b85 | 3804 | static inline u64 mem_cgroup_usage(struct mem_cgroup *memcg, bool swap) |
104f3928 | 3805 | { |
7d74b06f | 3806 | u64 val; |
104f3928 | 3807 | |
c0ff4b85 | 3808 | if (!mem_cgroup_is_root(memcg)) { |
104f3928 | 3809 | if (!swap) |
65c64ce8 | 3810 | return res_counter_read_u64(&memcg->res, RES_USAGE); |
104f3928 | 3811 | else |
65c64ce8 | 3812 | return res_counter_read_u64(&memcg->memsw, RES_USAGE); |
104f3928 KS |
3813 | } |
3814 | ||
c0ff4b85 R |
3815 | val = mem_cgroup_recursive_stat(memcg, MEM_CGROUP_STAT_CACHE); |
3816 | val += mem_cgroup_recursive_stat(memcg, MEM_CGROUP_STAT_RSS); | |
104f3928 | 3817 | |
7d74b06f | 3818 | if (swap) |
c0ff4b85 | 3819 | val += mem_cgroup_recursive_stat(memcg, MEM_CGROUP_STAT_SWAPOUT); |
104f3928 KS |
3820 | |
3821 | return val << PAGE_SHIFT; | |
3822 | } | |
3823 | ||
af36f906 TH |
3824 | static ssize_t mem_cgroup_read(struct cgroup *cont, struct cftype *cft, |
3825 | struct file *file, char __user *buf, | |
3826 | size_t nbytes, loff_t *ppos) | |
8cdea7c0 | 3827 | { |
c0ff4b85 | 3828 | struct mem_cgroup *memcg = mem_cgroup_from_cont(cont); |
af36f906 | 3829 | char str[64]; |
104f3928 | 3830 | u64 val; |
af36f906 | 3831 | int type, name, len; |
8c7c6e34 KH |
3832 | |
3833 | type = MEMFILE_TYPE(cft->private); | |
3834 | name = MEMFILE_ATTR(cft->private); | |
af36f906 TH |
3835 | |
3836 | if (!do_swap_account && type == _MEMSWAP) | |
3837 | return -EOPNOTSUPP; | |
3838 | ||
8c7c6e34 KH |
3839 | switch (type) { |
3840 | case _MEM: | |
104f3928 | 3841 | if (name == RES_USAGE) |
c0ff4b85 | 3842 | val = mem_cgroup_usage(memcg, false); |
104f3928 | 3843 | else |
c0ff4b85 | 3844 | val = res_counter_read_u64(&memcg->res, name); |
8c7c6e34 KH |
3845 | break; |
3846 | case _MEMSWAP: | |
104f3928 | 3847 | if (name == RES_USAGE) |
c0ff4b85 | 3848 | val = mem_cgroup_usage(memcg, true); |
104f3928 | 3849 | else |
c0ff4b85 | 3850 | val = res_counter_read_u64(&memcg->memsw, name); |
8c7c6e34 KH |
3851 | break; |
3852 | default: | |
3853 | BUG(); | |
8c7c6e34 | 3854 | } |
af36f906 TH |
3855 | |
3856 | len = scnprintf(str, sizeof(str), "%llu\n", (unsigned long long)val); | |
3857 | return simple_read_from_buffer(buf, nbytes, ppos, str, len); | |
8cdea7c0 | 3858 | } |
628f4235 KH |
3859 | /* |
3860 | * The user of this function is... | |
3861 | * RES_LIMIT. | |
3862 | */ | |
856c13aa PM |
3863 | static int mem_cgroup_write(struct cgroup *cont, struct cftype *cft, |
3864 | const char *buffer) | |
8cdea7c0 | 3865 | { |
628f4235 | 3866 | struct mem_cgroup *memcg = mem_cgroup_from_cont(cont); |
8c7c6e34 | 3867 | int type, name; |
628f4235 KH |
3868 | unsigned long long val; |
3869 | int ret; | |
3870 | ||
8c7c6e34 KH |
3871 | type = MEMFILE_TYPE(cft->private); |
3872 | name = MEMFILE_ATTR(cft->private); | |
af36f906 TH |
3873 | |
3874 | if (!do_swap_account && type == _MEMSWAP) | |
3875 | return -EOPNOTSUPP; | |
3876 | ||
8c7c6e34 | 3877 | switch (name) { |
628f4235 | 3878 | case RES_LIMIT: |
4b3bde4c BS |
3879 | if (mem_cgroup_is_root(memcg)) { /* Can't set limit on root */ |
3880 | ret = -EINVAL; | |
3881 | break; | |
3882 | } | |
628f4235 KH |
3883 | /* This function does all necessary parse...reuse it */ |
3884 | ret = res_counter_memparse_write_strategy(buffer, &val); | |
8c7c6e34 KH |
3885 | if (ret) |
3886 | break; | |
3887 | if (type == _MEM) | |
628f4235 | 3888 | ret = mem_cgroup_resize_limit(memcg, val); |
8c7c6e34 KH |
3889 | else |
3890 | ret = mem_cgroup_resize_memsw_limit(memcg, val); | |
628f4235 | 3891 | break; |
296c81d8 BS |
3892 | case RES_SOFT_LIMIT: |
3893 | ret = res_counter_memparse_write_strategy(buffer, &val); | |
3894 | if (ret) | |
3895 | break; | |
3896 | /* | |
3897 | * For memsw, soft limits are hard to implement in terms | |
3898 | * of semantics, for now, we support soft limits for | |
3899 | * control without swap | |
3900 | */ | |
3901 | if (type == _MEM) | |
3902 | ret = res_counter_set_soft_limit(&memcg->res, val); | |
3903 | else | |
3904 | ret = -EINVAL; | |
3905 | break; | |
628f4235 KH |
3906 | default: |
3907 | ret = -EINVAL; /* should be BUG() ? */ | |
3908 | break; | |
3909 | } | |
3910 | return ret; | |
8cdea7c0 BS |
3911 | } |
3912 | ||
fee7b548 KH |
3913 | static void memcg_get_hierarchical_limit(struct mem_cgroup *memcg, |
3914 | unsigned long long *mem_limit, unsigned long long *memsw_limit) | |
3915 | { | |
3916 | struct cgroup *cgroup; | |
3917 | unsigned long long min_limit, min_memsw_limit, tmp; | |
3918 | ||
3919 | min_limit = res_counter_read_u64(&memcg->res, RES_LIMIT); | |
3920 | min_memsw_limit = res_counter_read_u64(&memcg->memsw, RES_LIMIT); | |
3921 | cgroup = memcg->css.cgroup; | |
3922 | if (!memcg->use_hierarchy) | |
3923 | goto out; | |
3924 | ||
3925 | while (cgroup->parent) { | |
3926 | cgroup = cgroup->parent; | |
3927 | memcg = mem_cgroup_from_cont(cgroup); | |
3928 | if (!memcg->use_hierarchy) | |
3929 | break; | |
3930 | tmp = res_counter_read_u64(&memcg->res, RES_LIMIT); | |
3931 | min_limit = min(min_limit, tmp); | |
3932 | tmp = res_counter_read_u64(&memcg->memsw, RES_LIMIT); | |
3933 | min_memsw_limit = min(min_memsw_limit, tmp); | |
3934 | } | |
3935 | out: | |
3936 | *mem_limit = min_limit; | |
3937 | *memsw_limit = min_memsw_limit; | |
fee7b548 KH |
3938 | } |
3939 | ||
29f2a4da | 3940 | static int mem_cgroup_reset(struct cgroup *cont, unsigned int event) |
c84872e1 | 3941 | { |
af36f906 | 3942 | struct mem_cgroup *memcg = mem_cgroup_from_cont(cont); |
8c7c6e34 | 3943 | int type, name; |
c84872e1 | 3944 | |
8c7c6e34 KH |
3945 | type = MEMFILE_TYPE(event); |
3946 | name = MEMFILE_ATTR(event); | |
af36f906 TH |
3947 | |
3948 | if (!do_swap_account && type == _MEMSWAP) | |
3949 | return -EOPNOTSUPP; | |
3950 | ||
8c7c6e34 | 3951 | switch (name) { |
29f2a4da | 3952 | case RES_MAX_USAGE: |
8c7c6e34 | 3953 | if (type == _MEM) |
c0ff4b85 | 3954 | res_counter_reset_max(&memcg->res); |
8c7c6e34 | 3955 | else |
c0ff4b85 | 3956 | res_counter_reset_max(&memcg->memsw); |
29f2a4da PE |
3957 | break; |
3958 | case RES_FAILCNT: | |
8c7c6e34 | 3959 | if (type == _MEM) |
c0ff4b85 | 3960 | res_counter_reset_failcnt(&memcg->res); |
8c7c6e34 | 3961 | else |
c0ff4b85 | 3962 | res_counter_reset_failcnt(&memcg->memsw); |
29f2a4da PE |
3963 | break; |
3964 | } | |
f64c3f54 | 3965 | |
85cc59db | 3966 | return 0; |
c84872e1 PE |
3967 | } |
3968 | ||
7dc74be0 DN |
3969 | static u64 mem_cgroup_move_charge_read(struct cgroup *cgrp, |
3970 | struct cftype *cft) | |
3971 | { | |
3972 | return mem_cgroup_from_cont(cgrp)->move_charge_at_immigrate; | |
3973 | } | |
3974 | ||
02491447 | 3975 | #ifdef CONFIG_MMU |
7dc74be0 DN |
3976 | static int mem_cgroup_move_charge_write(struct cgroup *cgrp, |
3977 | struct cftype *cft, u64 val) | |
3978 | { | |
c0ff4b85 | 3979 | struct mem_cgroup *memcg = mem_cgroup_from_cont(cgrp); |
7dc74be0 DN |
3980 | |
3981 | if (val >= (1 << NR_MOVE_TYPE)) | |
3982 | return -EINVAL; | |
3983 | /* | |
3984 | * We check this value several times in both in can_attach() and | |
3985 | * attach(), so we need cgroup lock to prevent this value from being | |
3986 | * inconsistent. | |
3987 | */ | |
3988 | cgroup_lock(); | |
c0ff4b85 | 3989 | memcg->move_charge_at_immigrate = val; |
7dc74be0 DN |
3990 | cgroup_unlock(); |
3991 | ||
3992 | return 0; | |
3993 | } | |
02491447 DN |
3994 | #else |
3995 | static int mem_cgroup_move_charge_write(struct cgroup *cgrp, | |
3996 | struct cftype *cft, u64 val) | |
3997 | { | |
3998 | return -ENOSYS; | |
3999 | } | |
4000 | #endif | |
7dc74be0 | 4001 | |
406eb0c9 | 4002 | #ifdef CONFIG_NUMA |
fada52ca JW |
4003 | static int mem_control_numa_stat_show(struct cgroup *cont, struct cftype *cft, |
4004 | struct seq_file *m) | |
406eb0c9 YH |
4005 | { |
4006 | int nid; | |
4007 | unsigned long total_nr, file_nr, anon_nr, unevictable_nr; | |
4008 | unsigned long node_nr; | |
d79154bb | 4009 | struct mem_cgroup *memcg = mem_cgroup_from_cont(cont); |
406eb0c9 | 4010 | |
d79154bb | 4011 | total_nr = mem_cgroup_nr_lru_pages(memcg, LRU_ALL); |
406eb0c9 YH |
4012 | seq_printf(m, "total=%lu", total_nr); |
4013 | for_each_node_state(nid, N_HIGH_MEMORY) { | |
d79154bb | 4014 | node_nr = mem_cgroup_node_nr_lru_pages(memcg, nid, LRU_ALL); |
406eb0c9 YH |
4015 | seq_printf(m, " N%d=%lu", nid, node_nr); |
4016 | } | |
4017 | seq_putc(m, '\n'); | |
4018 | ||
d79154bb | 4019 | file_nr = mem_cgroup_nr_lru_pages(memcg, LRU_ALL_FILE); |
406eb0c9 YH |
4020 | seq_printf(m, "file=%lu", file_nr); |
4021 | for_each_node_state(nid, N_HIGH_MEMORY) { | |
d79154bb | 4022 | node_nr = mem_cgroup_node_nr_lru_pages(memcg, nid, |
bb2a0de9 | 4023 | LRU_ALL_FILE); |
406eb0c9 YH |
4024 | seq_printf(m, " N%d=%lu", nid, node_nr); |
4025 | } | |
4026 | seq_putc(m, '\n'); | |
4027 | ||
d79154bb | 4028 | anon_nr = mem_cgroup_nr_lru_pages(memcg, LRU_ALL_ANON); |
406eb0c9 YH |
4029 | seq_printf(m, "anon=%lu", anon_nr); |
4030 | for_each_node_state(nid, N_HIGH_MEMORY) { | |
d79154bb | 4031 | node_nr = mem_cgroup_node_nr_lru_pages(memcg, nid, |
bb2a0de9 | 4032 | LRU_ALL_ANON); |
406eb0c9 YH |
4033 | seq_printf(m, " N%d=%lu", nid, node_nr); |
4034 | } | |
4035 | seq_putc(m, '\n'); | |
4036 | ||
d79154bb | 4037 | unevictable_nr = mem_cgroup_nr_lru_pages(memcg, BIT(LRU_UNEVICTABLE)); |
406eb0c9 YH |
4038 | seq_printf(m, "unevictable=%lu", unevictable_nr); |
4039 | for_each_node_state(nid, N_HIGH_MEMORY) { | |
d79154bb | 4040 | node_nr = mem_cgroup_node_nr_lru_pages(memcg, nid, |
bb2a0de9 | 4041 | BIT(LRU_UNEVICTABLE)); |
406eb0c9 YH |
4042 | seq_printf(m, " N%d=%lu", nid, node_nr); |
4043 | } | |
4044 | seq_putc(m, '\n'); | |
4045 | return 0; | |
4046 | } | |
4047 | #endif /* CONFIG_NUMA */ | |
4048 | ||
af7c4b0e JW |
4049 | static const char * const mem_cgroup_lru_names[] = { |
4050 | "inactive_anon", | |
4051 | "active_anon", | |
4052 | "inactive_file", | |
4053 | "active_file", | |
4054 | "unevictable", | |
4055 | }; | |
4056 | ||
4057 | static inline void mem_cgroup_lru_names_not_uptodate(void) | |
4058 | { | |
4059 | BUILD_BUG_ON(ARRAY_SIZE(mem_cgroup_lru_names) != NR_LRU_LISTS); | |
4060 | } | |
4061 | ||
c64745cf | 4062 | static int mem_control_stat_show(struct cgroup *cont, struct cftype *cft, |
78ccf5b5 | 4063 | struct seq_file *m) |
d2ceb9b7 | 4064 | { |
d79154bb | 4065 | struct mem_cgroup *memcg = mem_cgroup_from_cont(cont); |
af7c4b0e JW |
4066 | struct mem_cgroup *mi; |
4067 | unsigned int i; | |
406eb0c9 | 4068 | |
af7c4b0e JW |
4069 | for (i = 0; i < MEM_CGROUP_STAT_NSTATS; i++) { |
4070 | if (i == MEM_CGROUP_STAT_SWAPOUT && !do_swap_account) | |
1dd3a273 | 4071 | continue; |
af7c4b0e JW |
4072 | seq_printf(m, "%s %ld\n", mem_cgroup_stat_names[i], |
4073 | mem_cgroup_read_stat(memcg, i) * PAGE_SIZE); | |
1dd3a273 | 4074 | } |
7b854121 | 4075 | |
af7c4b0e JW |
4076 | for (i = 0; i < MEM_CGROUP_EVENTS_NSTATS; i++) |
4077 | seq_printf(m, "%s %lu\n", mem_cgroup_events_names[i], | |
4078 | mem_cgroup_read_events(memcg, i)); | |
4079 | ||
4080 | for (i = 0; i < NR_LRU_LISTS; i++) | |
4081 | seq_printf(m, "%s %lu\n", mem_cgroup_lru_names[i], | |
4082 | mem_cgroup_nr_lru_pages(memcg, BIT(i)) * PAGE_SIZE); | |
4083 | ||
14067bb3 | 4084 | /* Hierarchical information */ |
fee7b548 KH |
4085 | { |
4086 | unsigned long long limit, memsw_limit; | |
d79154bb | 4087 | memcg_get_hierarchical_limit(memcg, &limit, &memsw_limit); |
78ccf5b5 | 4088 | seq_printf(m, "hierarchical_memory_limit %llu\n", limit); |
fee7b548 | 4089 | if (do_swap_account) |
78ccf5b5 JW |
4090 | seq_printf(m, "hierarchical_memsw_limit %llu\n", |
4091 | memsw_limit); | |
fee7b548 | 4092 | } |
7f016ee8 | 4093 | |
af7c4b0e JW |
4094 | for (i = 0; i < MEM_CGROUP_STAT_NSTATS; i++) { |
4095 | long long val = 0; | |
4096 | ||
4097 | if (i == MEM_CGROUP_STAT_SWAPOUT && !do_swap_account) | |
1dd3a273 | 4098 | continue; |
af7c4b0e JW |
4099 | for_each_mem_cgroup_tree(mi, memcg) |
4100 | val += mem_cgroup_read_stat(mi, i) * PAGE_SIZE; | |
4101 | seq_printf(m, "total_%s %lld\n", mem_cgroup_stat_names[i], val); | |
4102 | } | |
4103 | ||
4104 | for (i = 0; i < MEM_CGROUP_EVENTS_NSTATS; i++) { | |
4105 | unsigned long long val = 0; | |
4106 | ||
4107 | for_each_mem_cgroup_tree(mi, memcg) | |
4108 | val += mem_cgroup_read_events(mi, i); | |
4109 | seq_printf(m, "total_%s %llu\n", | |
4110 | mem_cgroup_events_names[i], val); | |
4111 | } | |
4112 | ||
4113 | for (i = 0; i < NR_LRU_LISTS; i++) { | |
4114 | unsigned long long val = 0; | |
4115 | ||
4116 | for_each_mem_cgroup_tree(mi, memcg) | |
4117 | val += mem_cgroup_nr_lru_pages(mi, BIT(i)) * PAGE_SIZE; | |
4118 | seq_printf(m, "total_%s %llu\n", mem_cgroup_lru_names[i], val); | |
1dd3a273 | 4119 | } |
14067bb3 | 4120 | |
7f016ee8 | 4121 | #ifdef CONFIG_DEBUG_VM |
7f016ee8 KM |
4122 | { |
4123 | int nid, zid; | |
4124 | struct mem_cgroup_per_zone *mz; | |
89abfab1 | 4125 | struct zone_reclaim_stat *rstat; |
7f016ee8 KM |
4126 | unsigned long recent_rotated[2] = {0, 0}; |
4127 | unsigned long recent_scanned[2] = {0, 0}; | |
4128 | ||
4129 | for_each_online_node(nid) | |
4130 | for (zid = 0; zid < MAX_NR_ZONES; zid++) { | |
d79154bb | 4131 | mz = mem_cgroup_zoneinfo(memcg, nid, zid); |
89abfab1 | 4132 | rstat = &mz->lruvec.reclaim_stat; |
7f016ee8 | 4133 | |
89abfab1 HD |
4134 | recent_rotated[0] += rstat->recent_rotated[0]; |
4135 | recent_rotated[1] += rstat->recent_rotated[1]; | |
4136 | recent_scanned[0] += rstat->recent_scanned[0]; | |
4137 | recent_scanned[1] += rstat->recent_scanned[1]; | |
7f016ee8 | 4138 | } |
78ccf5b5 JW |
4139 | seq_printf(m, "recent_rotated_anon %lu\n", recent_rotated[0]); |
4140 | seq_printf(m, "recent_rotated_file %lu\n", recent_rotated[1]); | |
4141 | seq_printf(m, "recent_scanned_anon %lu\n", recent_scanned[0]); | |
4142 | seq_printf(m, "recent_scanned_file %lu\n", recent_scanned[1]); | |
7f016ee8 KM |
4143 | } |
4144 | #endif | |
4145 | ||
d2ceb9b7 KH |
4146 | return 0; |
4147 | } | |
4148 | ||
a7885eb8 KM |
4149 | static u64 mem_cgroup_swappiness_read(struct cgroup *cgrp, struct cftype *cft) |
4150 | { | |
4151 | struct mem_cgroup *memcg = mem_cgroup_from_cont(cgrp); | |
4152 | ||
1f4c025b | 4153 | return mem_cgroup_swappiness(memcg); |
a7885eb8 KM |
4154 | } |
4155 | ||
4156 | static int mem_cgroup_swappiness_write(struct cgroup *cgrp, struct cftype *cft, | |
4157 | u64 val) | |
4158 | { | |
4159 | struct mem_cgroup *memcg = mem_cgroup_from_cont(cgrp); | |
4160 | struct mem_cgroup *parent; | |
068b38c1 | 4161 | |
a7885eb8 KM |
4162 | if (val > 100) |
4163 | return -EINVAL; | |
4164 | ||
4165 | if (cgrp->parent == NULL) | |
4166 | return -EINVAL; | |
4167 | ||
4168 | parent = mem_cgroup_from_cont(cgrp->parent); | |
068b38c1 LZ |
4169 | |
4170 | cgroup_lock(); | |
4171 | ||
a7885eb8 KM |
4172 | /* If under hierarchy, only empty-root can set this value */ |
4173 | if ((parent->use_hierarchy) || | |
068b38c1 LZ |
4174 | (memcg->use_hierarchy && !list_empty(&cgrp->children))) { |
4175 | cgroup_unlock(); | |
a7885eb8 | 4176 | return -EINVAL; |
068b38c1 | 4177 | } |
a7885eb8 | 4178 | |
a7885eb8 | 4179 | memcg->swappiness = val; |
a7885eb8 | 4180 | |
068b38c1 LZ |
4181 | cgroup_unlock(); |
4182 | ||
a7885eb8 KM |
4183 | return 0; |
4184 | } | |
4185 | ||
2e72b634 KS |
4186 | static void __mem_cgroup_threshold(struct mem_cgroup *memcg, bool swap) |
4187 | { | |
4188 | struct mem_cgroup_threshold_ary *t; | |
4189 | u64 usage; | |
4190 | int i; | |
4191 | ||
4192 | rcu_read_lock(); | |
4193 | if (!swap) | |
2c488db2 | 4194 | t = rcu_dereference(memcg->thresholds.primary); |
2e72b634 | 4195 | else |
2c488db2 | 4196 | t = rcu_dereference(memcg->memsw_thresholds.primary); |
2e72b634 KS |
4197 | |
4198 | if (!t) | |
4199 | goto unlock; | |
4200 | ||
4201 | usage = mem_cgroup_usage(memcg, swap); | |
4202 | ||
4203 | /* | |
748dad36 | 4204 | * current_threshold points to threshold just below or equal to usage. |
2e72b634 KS |
4205 | * If it's not true, a threshold was crossed after last |
4206 | * call of __mem_cgroup_threshold(). | |
4207 | */ | |
5407a562 | 4208 | i = t->current_threshold; |
2e72b634 KS |
4209 | |
4210 | /* | |
4211 | * Iterate backward over array of thresholds starting from | |
4212 | * current_threshold and check if a threshold is crossed. | |
4213 | * If none of thresholds below usage is crossed, we read | |
4214 | * only one element of the array here. | |
4215 | */ | |
4216 | for (; i >= 0 && unlikely(t->entries[i].threshold > usage); i--) | |
4217 | eventfd_signal(t->entries[i].eventfd, 1); | |
4218 | ||
4219 | /* i = current_threshold + 1 */ | |
4220 | i++; | |
4221 | ||
4222 | /* | |
4223 | * Iterate forward over array of thresholds starting from | |
4224 | * current_threshold+1 and check if a threshold is crossed. | |
4225 | * If none of thresholds above usage is crossed, we read | |
4226 | * only one element of the array here. | |
4227 | */ | |
4228 | for (; i < t->size && unlikely(t->entries[i].threshold <= usage); i++) | |
4229 | eventfd_signal(t->entries[i].eventfd, 1); | |
4230 | ||
4231 | /* Update current_threshold */ | |
5407a562 | 4232 | t->current_threshold = i - 1; |
2e72b634 KS |
4233 | unlock: |
4234 | rcu_read_unlock(); | |
4235 | } | |
4236 | ||
4237 | static void mem_cgroup_threshold(struct mem_cgroup *memcg) | |
4238 | { | |
ad4ca5f4 KS |
4239 | while (memcg) { |
4240 | __mem_cgroup_threshold(memcg, false); | |
4241 | if (do_swap_account) | |
4242 | __mem_cgroup_threshold(memcg, true); | |
4243 | ||
4244 | memcg = parent_mem_cgroup(memcg); | |
4245 | } | |
2e72b634 KS |
4246 | } |
4247 | ||
4248 | static int compare_thresholds(const void *a, const void *b) | |
4249 | { | |
4250 | const struct mem_cgroup_threshold *_a = a; | |
4251 | const struct mem_cgroup_threshold *_b = b; | |
4252 | ||
4253 | return _a->threshold - _b->threshold; | |
4254 | } | |
4255 | ||
c0ff4b85 | 4256 | static int mem_cgroup_oom_notify_cb(struct mem_cgroup *memcg) |
9490ff27 KH |
4257 | { |
4258 | struct mem_cgroup_eventfd_list *ev; | |
4259 | ||
c0ff4b85 | 4260 | list_for_each_entry(ev, &memcg->oom_notify, list) |
9490ff27 KH |
4261 | eventfd_signal(ev->eventfd, 1); |
4262 | return 0; | |
4263 | } | |
4264 | ||
c0ff4b85 | 4265 | static void mem_cgroup_oom_notify(struct mem_cgroup *memcg) |
9490ff27 | 4266 | { |
7d74b06f KH |
4267 | struct mem_cgroup *iter; |
4268 | ||
c0ff4b85 | 4269 | for_each_mem_cgroup_tree(iter, memcg) |
7d74b06f | 4270 | mem_cgroup_oom_notify_cb(iter); |
9490ff27 KH |
4271 | } |
4272 | ||
4273 | static int mem_cgroup_usage_register_event(struct cgroup *cgrp, | |
4274 | struct cftype *cft, struct eventfd_ctx *eventfd, const char *args) | |
2e72b634 KS |
4275 | { |
4276 | struct mem_cgroup *memcg = mem_cgroup_from_cont(cgrp); | |
2c488db2 KS |
4277 | struct mem_cgroup_thresholds *thresholds; |
4278 | struct mem_cgroup_threshold_ary *new; | |
2e72b634 KS |
4279 | int type = MEMFILE_TYPE(cft->private); |
4280 | u64 threshold, usage; | |
2c488db2 | 4281 | int i, size, ret; |
2e72b634 KS |
4282 | |
4283 | ret = res_counter_memparse_write_strategy(args, &threshold); | |
4284 | if (ret) | |
4285 | return ret; | |
4286 | ||
4287 | mutex_lock(&memcg->thresholds_lock); | |
2c488db2 | 4288 | |
2e72b634 | 4289 | if (type == _MEM) |
2c488db2 | 4290 | thresholds = &memcg->thresholds; |
2e72b634 | 4291 | else if (type == _MEMSWAP) |
2c488db2 | 4292 | thresholds = &memcg->memsw_thresholds; |
2e72b634 KS |
4293 | else |
4294 | BUG(); | |
4295 | ||
4296 | usage = mem_cgroup_usage(memcg, type == _MEMSWAP); | |
4297 | ||
4298 | /* Check if a threshold crossed before adding a new one */ | |
2c488db2 | 4299 | if (thresholds->primary) |
2e72b634 KS |
4300 | __mem_cgroup_threshold(memcg, type == _MEMSWAP); |
4301 | ||
2c488db2 | 4302 | size = thresholds->primary ? thresholds->primary->size + 1 : 1; |
2e72b634 KS |
4303 | |
4304 | /* Allocate memory for new array of thresholds */ | |
2c488db2 | 4305 | new = kmalloc(sizeof(*new) + size * sizeof(struct mem_cgroup_threshold), |
2e72b634 | 4306 | GFP_KERNEL); |
2c488db2 | 4307 | if (!new) { |
2e72b634 KS |
4308 | ret = -ENOMEM; |
4309 | goto unlock; | |
4310 | } | |
2c488db2 | 4311 | new->size = size; |
2e72b634 KS |
4312 | |
4313 | /* Copy thresholds (if any) to new array */ | |
2c488db2 KS |
4314 | if (thresholds->primary) { |
4315 | memcpy(new->entries, thresholds->primary->entries, (size - 1) * | |
2e72b634 | 4316 | sizeof(struct mem_cgroup_threshold)); |
2c488db2 KS |
4317 | } |
4318 | ||
2e72b634 | 4319 | /* Add new threshold */ |
2c488db2 KS |
4320 | new->entries[size - 1].eventfd = eventfd; |
4321 | new->entries[size - 1].threshold = threshold; | |
2e72b634 KS |
4322 | |
4323 | /* Sort thresholds. Registering of new threshold isn't time-critical */ | |
2c488db2 | 4324 | sort(new->entries, size, sizeof(struct mem_cgroup_threshold), |
2e72b634 KS |
4325 | compare_thresholds, NULL); |
4326 | ||
4327 | /* Find current threshold */ | |
2c488db2 | 4328 | new->current_threshold = -1; |
2e72b634 | 4329 | for (i = 0; i < size; i++) { |
748dad36 | 4330 | if (new->entries[i].threshold <= usage) { |
2e72b634 | 4331 | /* |
2c488db2 KS |
4332 | * new->current_threshold will not be used until |
4333 | * rcu_assign_pointer(), so it's safe to increment | |
2e72b634 KS |
4334 | * it here. |
4335 | */ | |
2c488db2 | 4336 | ++new->current_threshold; |
748dad36 SZ |
4337 | } else |
4338 | break; | |
2e72b634 KS |
4339 | } |
4340 | ||
2c488db2 KS |
4341 | /* Free old spare buffer and save old primary buffer as spare */ |
4342 | kfree(thresholds->spare); | |
4343 | thresholds->spare = thresholds->primary; | |
4344 | ||
4345 | rcu_assign_pointer(thresholds->primary, new); | |
2e72b634 | 4346 | |
907860ed | 4347 | /* To be sure that nobody uses thresholds */ |
2e72b634 KS |
4348 | synchronize_rcu(); |
4349 | ||
2e72b634 KS |
4350 | unlock: |
4351 | mutex_unlock(&memcg->thresholds_lock); | |
4352 | ||
4353 | return ret; | |
4354 | } | |
4355 | ||
907860ed | 4356 | static void mem_cgroup_usage_unregister_event(struct cgroup *cgrp, |
9490ff27 | 4357 | struct cftype *cft, struct eventfd_ctx *eventfd) |
2e72b634 KS |
4358 | { |
4359 | struct mem_cgroup *memcg = mem_cgroup_from_cont(cgrp); | |
2c488db2 KS |
4360 | struct mem_cgroup_thresholds *thresholds; |
4361 | struct mem_cgroup_threshold_ary *new; | |
2e72b634 KS |
4362 | int type = MEMFILE_TYPE(cft->private); |
4363 | u64 usage; | |
2c488db2 | 4364 | int i, j, size; |
2e72b634 KS |
4365 | |
4366 | mutex_lock(&memcg->thresholds_lock); | |
4367 | if (type == _MEM) | |
2c488db2 | 4368 | thresholds = &memcg->thresholds; |
2e72b634 | 4369 | else if (type == _MEMSWAP) |
2c488db2 | 4370 | thresholds = &memcg->memsw_thresholds; |
2e72b634 KS |
4371 | else |
4372 | BUG(); | |
4373 | ||
371528ca AV |
4374 | if (!thresholds->primary) |
4375 | goto unlock; | |
4376 | ||
2e72b634 KS |
4377 | usage = mem_cgroup_usage(memcg, type == _MEMSWAP); |
4378 | ||
4379 | /* Check if a threshold crossed before removing */ | |
4380 | __mem_cgroup_threshold(memcg, type == _MEMSWAP); | |
4381 | ||
4382 | /* Calculate new number of threshold */ | |
2c488db2 KS |
4383 | size = 0; |
4384 | for (i = 0; i < thresholds->primary->size; i++) { | |
4385 | if (thresholds->primary->entries[i].eventfd != eventfd) | |
2e72b634 KS |
4386 | size++; |
4387 | } | |
4388 | ||
2c488db2 | 4389 | new = thresholds->spare; |
907860ed | 4390 | |
2e72b634 KS |
4391 | /* Set thresholds array to NULL if we don't have thresholds */ |
4392 | if (!size) { | |
2c488db2 KS |
4393 | kfree(new); |
4394 | new = NULL; | |
907860ed | 4395 | goto swap_buffers; |
2e72b634 KS |
4396 | } |
4397 | ||
2c488db2 | 4398 | new->size = size; |
2e72b634 KS |
4399 | |
4400 | /* Copy thresholds and find current threshold */ | |
2c488db2 KS |
4401 | new->current_threshold = -1; |
4402 | for (i = 0, j = 0; i < thresholds->primary->size; i++) { | |
4403 | if (thresholds->primary->entries[i].eventfd == eventfd) | |
2e72b634 KS |
4404 | continue; |
4405 | ||
2c488db2 | 4406 | new->entries[j] = thresholds->primary->entries[i]; |
748dad36 | 4407 | if (new->entries[j].threshold <= usage) { |
2e72b634 | 4408 | /* |
2c488db2 | 4409 | * new->current_threshold will not be used |
2e72b634 KS |
4410 | * until rcu_assign_pointer(), so it's safe to increment |
4411 | * it here. | |
4412 | */ | |
2c488db2 | 4413 | ++new->current_threshold; |
2e72b634 KS |
4414 | } |
4415 | j++; | |
4416 | } | |
4417 | ||
907860ed | 4418 | swap_buffers: |
2c488db2 KS |
4419 | /* Swap primary and spare array */ |
4420 | thresholds->spare = thresholds->primary; | |
8c757763 SZ |
4421 | /* If all events are unregistered, free the spare array */ |
4422 | if (!new) { | |
4423 | kfree(thresholds->spare); | |
4424 | thresholds->spare = NULL; | |
4425 | } | |
4426 | ||
2c488db2 | 4427 | rcu_assign_pointer(thresholds->primary, new); |
2e72b634 | 4428 | |
907860ed | 4429 | /* To be sure that nobody uses thresholds */ |
2e72b634 | 4430 | synchronize_rcu(); |
371528ca | 4431 | unlock: |
2e72b634 | 4432 | mutex_unlock(&memcg->thresholds_lock); |
2e72b634 | 4433 | } |
c1e862c1 | 4434 | |
9490ff27 KH |
4435 | static int mem_cgroup_oom_register_event(struct cgroup *cgrp, |
4436 | struct cftype *cft, struct eventfd_ctx *eventfd, const char *args) | |
4437 | { | |
4438 | struct mem_cgroup *memcg = mem_cgroup_from_cont(cgrp); | |
4439 | struct mem_cgroup_eventfd_list *event; | |
4440 | int type = MEMFILE_TYPE(cft->private); | |
4441 | ||
4442 | BUG_ON(type != _OOM_TYPE); | |
4443 | event = kmalloc(sizeof(*event), GFP_KERNEL); | |
4444 | if (!event) | |
4445 | return -ENOMEM; | |
4446 | ||
1af8efe9 | 4447 | spin_lock(&memcg_oom_lock); |
9490ff27 KH |
4448 | |
4449 | event->eventfd = eventfd; | |
4450 | list_add(&event->list, &memcg->oom_notify); | |
4451 | ||
4452 | /* already in OOM ? */ | |
79dfdacc | 4453 | if (atomic_read(&memcg->under_oom)) |
9490ff27 | 4454 | eventfd_signal(eventfd, 1); |
1af8efe9 | 4455 | spin_unlock(&memcg_oom_lock); |
9490ff27 KH |
4456 | |
4457 | return 0; | |
4458 | } | |
4459 | ||
907860ed | 4460 | static void mem_cgroup_oom_unregister_event(struct cgroup *cgrp, |
9490ff27 KH |
4461 | struct cftype *cft, struct eventfd_ctx *eventfd) |
4462 | { | |
c0ff4b85 | 4463 | struct mem_cgroup *memcg = mem_cgroup_from_cont(cgrp); |
9490ff27 KH |
4464 | struct mem_cgroup_eventfd_list *ev, *tmp; |
4465 | int type = MEMFILE_TYPE(cft->private); | |
4466 | ||
4467 | BUG_ON(type != _OOM_TYPE); | |
4468 | ||
1af8efe9 | 4469 | spin_lock(&memcg_oom_lock); |
9490ff27 | 4470 | |
c0ff4b85 | 4471 | list_for_each_entry_safe(ev, tmp, &memcg->oom_notify, list) { |
9490ff27 KH |
4472 | if (ev->eventfd == eventfd) { |
4473 | list_del(&ev->list); | |
4474 | kfree(ev); | |
4475 | } | |
4476 | } | |
4477 | ||
1af8efe9 | 4478 | spin_unlock(&memcg_oom_lock); |
9490ff27 KH |
4479 | } |
4480 | ||
3c11ecf4 KH |
4481 | static int mem_cgroup_oom_control_read(struct cgroup *cgrp, |
4482 | struct cftype *cft, struct cgroup_map_cb *cb) | |
4483 | { | |
c0ff4b85 | 4484 | struct mem_cgroup *memcg = mem_cgroup_from_cont(cgrp); |
3c11ecf4 | 4485 | |
c0ff4b85 | 4486 | cb->fill(cb, "oom_kill_disable", memcg->oom_kill_disable); |
3c11ecf4 | 4487 | |
c0ff4b85 | 4488 | if (atomic_read(&memcg->under_oom)) |
3c11ecf4 KH |
4489 | cb->fill(cb, "under_oom", 1); |
4490 | else | |
4491 | cb->fill(cb, "under_oom", 0); | |
4492 | return 0; | |
4493 | } | |
4494 | ||
3c11ecf4 KH |
4495 | static int mem_cgroup_oom_control_write(struct cgroup *cgrp, |
4496 | struct cftype *cft, u64 val) | |
4497 | { | |
c0ff4b85 | 4498 | struct mem_cgroup *memcg = mem_cgroup_from_cont(cgrp); |
3c11ecf4 KH |
4499 | struct mem_cgroup *parent; |
4500 | ||
4501 | /* cannot set to root cgroup and only 0 and 1 are allowed */ | |
4502 | if (!cgrp->parent || !((val == 0) || (val == 1))) | |
4503 | return -EINVAL; | |
4504 | ||
4505 | parent = mem_cgroup_from_cont(cgrp->parent); | |
4506 | ||
4507 | cgroup_lock(); | |
4508 | /* oom-kill-disable is a flag for subhierarchy. */ | |
4509 | if ((parent->use_hierarchy) || | |
c0ff4b85 | 4510 | (memcg->use_hierarchy && !list_empty(&cgrp->children))) { |
3c11ecf4 KH |
4511 | cgroup_unlock(); |
4512 | return -EINVAL; | |
4513 | } | |
c0ff4b85 | 4514 | memcg->oom_kill_disable = val; |
4d845ebf | 4515 | if (!val) |
c0ff4b85 | 4516 | memcg_oom_recover(memcg); |
3c11ecf4 KH |
4517 | cgroup_unlock(); |
4518 | return 0; | |
4519 | } | |
4520 | ||
e5671dfa | 4521 | #ifdef CONFIG_CGROUP_MEM_RES_CTLR_KMEM |
cbe128e3 | 4522 | static int memcg_init_kmem(struct mem_cgroup *memcg, struct cgroup_subsys *ss) |
e5671dfa | 4523 | { |
1d62e436 | 4524 | return mem_cgroup_sockets_init(memcg, ss); |
e5671dfa GC |
4525 | }; |
4526 | ||
1d62e436 | 4527 | static void kmem_cgroup_destroy(struct mem_cgroup *memcg) |
d1a4c0b3 | 4528 | { |
1d62e436 | 4529 | mem_cgroup_sockets_destroy(memcg); |
d1a4c0b3 | 4530 | } |
e5671dfa | 4531 | #else |
cbe128e3 | 4532 | static int memcg_init_kmem(struct mem_cgroup *memcg, struct cgroup_subsys *ss) |
e5671dfa GC |
4533 | { |
4534 | return 0; | |
4535 | } | |
d1a4c0b3 | 4536 | |
1d62e436 | 4537 | static void kmem_cgroup_destroy(struct mem_cgroup *memcg) |
d1a4c0b3 GC |
4538 | { |
4539 | } | |
e5671dfa GC |
4540 | #endif |
4541 | ||
8cdea7c0 BS |
4542 | static struct cftype mem_cgroup_files[] = { |
4543 | { | |
0eea1030 | 4544 | .name = "usage_in_bytes", |
8c7c6e34 | 4545 | .private = MEMFILE_PRIVATE(_MEM, RES_USAGE), |
af36f906 | 4546 | .read = mem_cgroup_read, |
9490ff27 KH |
4547 | .register_event = mem_cgroup_usage_register_event, |
4548 | .unregister_event = mem_cgroup_usage_unregister_event, | |
8cdea7c0 | 4549 | }, |
c84872e1 PE |
4550 | { |
4551 | .name = "max_usage_in_bytes", | |
8c7c6e34 | 4552 | .private = MEMFILE_PRIVATE(_MEM, RES_MAX_USAGE), |
29f2a4da | 4553 | .trigger = mem_cgroup_reset, |
af36f906 | 4554 | .read = mem_cgroup_read, |
c84872e1 | 4555 | }, |
8cdea7c0 | 4556 | { |
0eea1030 | 4557 | .name = "limit_in_bytes", |
8c7c6e34 | 4558 | .private = MEMFILE_PRIVATE(_MEM, RES_LIMIT), |
856c13aa | 4559 | .write_string = mem_cgroup_write, |
af36f906 | 4560 | .read = mem_cgroup_read, |
8cdea7c0 | 4561 | }, |
296c81d8 BS |
4562 | { |
4563 | .name = "soft_limit_in_bytes", | |
4564 | .private = MEMFILE_PRIVATE(_MEM, RES_SOFT_LIMIT), | |
4565 | .write_string = mem_cgroup_write, | |
af36f906 | 4566 | .read = mem_cgroup_read, |
296c81d8 | 4567 | }, |
8cdea7c0 BS |
4568 | { |
4569 | .name = "failcnt", | |
8c7c6e34 | 4570 | .private = MEMFILE_PRIVATE(_MEM, RES_FAILCNT), |
29f2a4da | 4571 | .trigger = mem_cgroup_reset, |
af36f906 | 4572 | .read = mem_cgroup_read, |
8cdea7c0 | 4573 | }, |
d2ceb9b7 KH |
4574 | { |
4575 | .name = "stat", | |
78ccf5b5 | 4576 | .read_seq_string = mem_control_stat_show, |
d2ceb9b7 | 4577 | }, |
c1e862c1 KH |
4578 | { |
4579 | .name = "force_empty", | |
4580 | .trigger = mem_cgroup_force_empty_write, | |
4581 | }, | |
18f59ea7 BS |
4582 | { |
4583 | .name = "use_hierarchy", | |
4584 | .write_u64 = mem_cgroup_hierarchy_write, | |
4585 | .read_u64 = mem_cgroup_hierarchy_read, | |
4586 | }, | |
a7885eb8 KM |
4587 | { |
4588 | .name = "swappiness", | |
4589 | .read_u64 = mem_cgroup_swappiness_read, | |
4590 | .write_u64 = mem_cgroup_swappiness_write, | |
4591 | }, | |
7dc74be0 DN |
4592 | { |
4593 | .name = "move_charge_at_immigrate", | |
4594 | .read_u64 = mem_cgroup_move_charge_read, | |
4595 | .write_u64 = mem_cgroup_move_charge_write, | |
4596 | }, | |
9490ff27 KH |
4597 | { |
4598 | .name = "oom_control", | |
3c11ecf4 KH |
4599 | .read_map = mem_cgroup_oom_control_read, |
4600 | .write_u64 = mem_cgroup_oom_control_write, | |
9490ff27 KH |
4601 | .register_event = mem_cgroup_oom_register_event, |
4602 | .unregister_event = mem_cgroup_oom_unregister_event, | |
4603 | .private = MEMFILE_PRIVATE(_OOM_TYPE, OOM_CONTROL), | |
4604 | }, | |
406eb0c9 YH |
4605 | #ifdef CONFIG_NUMA |
4606 | { | |
4607 | .name = "numa_stat", | |
fada52ca | 4608 | .read_seq_string = mem_control_numa_stat_show, |
406eb0c9 YH |
4609 | }, |
4610 | #endif | |
8c7c6e34 | 4611 | #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP |
8c7c6e34 KH |
4612 | { |
4613 | .name = "memsw.usage_in_bytes", | |
4614 | .private = MEMFILE_PRIVATE(_MEMSWAP, RES_USAGE), | |
af36f906 | 4615 | .read = mem_cgroup_read, |
9490ff27 KH |
4616 | .register_event = mem_cgroup_usage_register_event, |
4617 | .unregister_event = mem_cgroup_usage_unregister_event, | |
8c7c6e34 KH |
4618 | }, |
4619 | { | |
4620 | .name = "memsw.max_usage_in_bytes", | |
4621 | .private = MEMFILE_PRIVATE(_MEMSWAP, RES_MAX_USAGE), | |
4622 | .trigger = mem_cgroup_reset, | |
af36f906 | 4623 | .read = mem_cgroup_read, |
8c7c6e34 KH |
4624 | }, |
4625 | { | |
4626 | .name = "memsw.limit_in_bytes", | |
4627 | .private = MEMFILE_PRIVATE(_MEMSWAP, RES_LIMIT), | |
4628 | .write_string = mem_cgroup_write, | |
af36f906 | 4629 | .read = mem_cgroup_read, |
8c7c6e34 KH |
4630 | }, |
4631 | { | |
4632 | .name = "memsw.failcnt", | |
4633 | .private = MEMFILE_PRIVATE(_MEMSWAP, RES_FAILCNT), | |
4634 | .trigger = mem_cgroup_reset, | |
af36f906 | 4635 | .read = mem_cgroup_read, |
8c7c6e34 | 4636 | }, |
8c7c6e34 | 4637 | #endif |
6bc10349 | 4638 | { }, /* terminate */ |
af36f906 | 4639 | }; |
8c7c6e34 | 4640 | |
c0ff4b85 | 4641 | static int alloc_mem_cgroup_per_zone_info(struct mem_cgroup *memcg, int node) |
6d12e2d8 KH |
4642 | { |
4643 | struct mem_cgroup_per_node *pn; | |
1ecaab2b | 4644 | struct mem_cgroup_per_zone *mz; |
41e3355d | 4645 | int zone, tmp = node; |
1ecaab2b KH |
4646 | /* |
4647 | * This routine is called against possible nodes. | |
4648 | * But it's BUG to call kmalloc() against offline node. | |
4649 | * | |
4650 | * TODO: this routine can waste much memory for nodes which will | |
4651 | * never be onlined. It's better to use memory hotplug callback | |
4652 | * function. | |
4653 | */ | |
41e3355d KH |
4654 | if (!node_state(node, N_NORMAL_MEMORY)) |
4655 | tmp = -1; | |
17295c88 | 4656 | pn = kzalloc_node(sizeof(*pn), GFP_KERNEL, tmp); |
6d12e2d8 KH |
4657 | if (!pn) |
4658 | return 1; | |
1ecaab2b | 4659 | |
1ecaab2b KH |
4660 | for (zone = 0; zone < MAX_NR_ZONES; zone++) { |
4661 | mz = &pn->zoneinfo[zone]; | |
7f5e86c2 | 4662 | lruvec_init(&mz->lruvec, &NODE_DATA(node)->node_zones[zone]); |
f64c3f54 | 4663 | mz->usage_in_excess = 0; |
4e416953 | 4664 | mz->on_tree = false; |
d79154bb | 4665 | mz->memcg = memcg; |
1ecaab2b | 4666 | } |
0a619e58 | 4667 | memcg->info.nodeinfo[node] = pn; |
6d12e2d8 KH |
4668 | return 0; |
4669 | } | |
4670 | ||
c0ff4b85 | 4671 | static void free_mem_cgroup_per_zone_info(struct mem_cgroup *memcg, int node) |
1ecaab2b | 4672 | { |
c0ff4b85 | 4673 | kfree(memcg->info.nodeinfo[node]); |
1ecaab2b KH |
4674 | } |
4675 | ||
33327948 KH |
4676 | static struct mem_cgroup *mem_cgroup_alloc(void) |
4677 | { | |
d79154bb | 4678 | struct mem_cgroup *memcg; |
c62b1a3b | 4679 | int size = sizeof(struct mem_cgroup); |
33327948 | 4680 | |
c62b1a3b | 4681 | /* Can be very big if MAX_NUMNODES is very big */ |
c8dad2bb | 4682 | if (size < PAGE_SIZE) |
d79154bb | 4683 | memcg = kzalloc(size, GFP_KERNEL); |
33327948 | 4684 | else |
d79154bb | 4685 | memcg = vzalloc(size); |
33327948 | 4686 | |
d79154bb | 4687 | if (!memcg) |
e7bbcdf3 DC |
4688 | return NULL; |
4689 | ||
d79154bb HD |
4690 | memcg->stat = alloc_percpu(struct mem_cgroup_stat_cpu); |
4691 | if (!memcg->stat) | |
d2e61b8d | 4692 | goto out_free; |
d79154bb HD |
4693 | spin_lock_init(&memcg->pcp_counter_lock); |
4694 | return memcg; | |
d2e61b8d DC |
4695 | |
4696 | out_free: | |
4697 | if (size < PAGE_SIZE) | |
d79154bb | 4698 | kfree(memcg); |
d2e61b8d | 4699 | else |
d79154bb | 4700 | vfree(memcg); |
d2e61b8d | 4701 | return NULL; |
33327948 KH |
4702 | } |
4703 | ||
59927fb9 | 4704 | /* |
3afe36b1 | 4705 | * Helpers for freeing a kmalloc()ed/vzalloc()ed mem_cgroup by RCU, |
59927fb9 HD |
4706 | * but in process context. The work_freeing structure is overlaid |
4707 | * on the rcu_freeing structure, which itself is overlaid on memsw. | |
4708 | */ | |
3afe36b1 | 4709 | static void free_work(struct work_struct *work) |
59927fb9 HD |
4710 | { |
4711 | struct mem_cgroup *memcg; | |
3afe36b1 | 4712 | int size = sizeof(struct mem_cgroup); |
59927fb9 HD |
4713 | |
4714 | memcg = container_of(work, struct mem_cgroup, work_freeing); | |
3afe36b1 GC |
4715 | if (size < PAGE_SIZE) |
4716 | kfree(memcg); | |
4717 | else | |
4718 | vfree(memcg); | |
59927fb9 | 4719 | } |
3afe36b1 GC |
4720 | |
4721 | static void free_rcu(struct rcu_head *rcu_head) | |
59927fb9 HD |
4722 | { |
4723 | struct mem_cgroup *memcg; | |
4724 | ||
4725 | memcg = container_of(rcu_head, struct mem_cgroup, rcu_freeing); | |
3afe36b1 | 4726 | INIT_WORK(&memcg->work_freeing, free_work); |
59927fb9 HD |
4727 | schedule_work(&memcg->work_freeing); |
4728 | } | |
4729 | ||
8c7c6e34 KH |
4730 | /* |
4731 | * At destroying mem_cgroup, references from swap_cgroup can remain. | |
4732 | * (scanning all at force_empty is too costly...) | |
4733 | * | |
4734 | * Instead of clearing all references at force_empty, we remember | |
4735 | * the number of reference from swap_cgroup and free mem_cgroup when | |
4736 | * it goes down to 0. | |
4737 | * | |
8c7c6e34 KH |
4738 | * Removal of cgroup itself succeeds regardless of refs from swap. |
4739 | */ | |
4740 | ||
c0ff4b85 | 4741 | static void __mem_cgroup_free(struct mem_cgroup *memcg) |
33327948 | 4742 | { |
08e552c6 KH |
4743 | int node; |
4744 | ||
c0ff4b85 R |
4745 | mem_cgroup_remove_from_trees(memcg); |
4746 | free_css_id(&mem_cgroup_subsys, &memcg->css); | |
04046e1a | 4747 | |
3ed28fa1 | 4748 | for_each_node(node) |
c0ff4b85 | 4749 | free_mem_cgroup_per_zone_info(memcg, node); |
08e552c6 | 4750 | |
c0ff4b85 | 4751 | free_percpu(memcg->stat); |
3afe36b1 | 4752 | call_rcu(&memcg->rcu_freeing, free_rcu); |
33327948 KH |
4753 | } |
4754 | ||
c0ff4b85 | 4755 | static void mem_cgroup_get(struct mem_cgroup *memcg) |
8c7c6e34 | 4756 | { |
c0ff4b85 | 4757 | atomic_inc(&memcg->refcnt); |
8c7c6e34 KH |
4758 | } |
4759 | ||
c0ff4b85 | 4760 | static void __mem_cgroup_put(struct mem_cgroup *memcg, int count) |
8c7c6e34 | 4761 | { |
c0ff4b85 R |
4762 | if (atomic_sub_and_test(count, &memcg->refcnt)) { |
4763 | struct mem_cgroup *parent = parent_mem_cgroup(memcg); | |
4764 | __mem_cgroup_free(memcg); | |
7bcc1bb1 DN |
4765 | if (parent) |
4766 | mem_cgroup_put(parent); | |
4767 | } | |
8c7c6e34 KH |
4768 | } |
4769 | ||
c0ff4b85 | 4770 | static void mem_cgroup_put(struct mem_cgroup *memcg) |
483c30b5 | 4771 | { |
c0ff4b85 | 4772 | __mem_cgroup_put(memcg, 1); |
483c30b5 DN |
4773 | } |
4774 | ||
7bcc1bb1 DN |
4775 | /* |
4776 | * Returns the parent mem_cgroup in memcgroup hierarchy with hierarchy enabled. | |
4777 | */ | |
e1aab161 | 4778 | struct mem_cgroup *parent_mem_cgroup(struct mem_cgroup *memcg) |
7bcc1bb1 | 4779 | { |
c0ff4b85 | 4780 | if (!memcg->res.parent) |
7bcc1bb1 | 4781 | return NULL; |
c0ff4b85 | 4782 | return mem_cgroup_from_res_counter(memcg->res.parent, res); |
7bcc1bb1 | 4783 | } |
e1aab161 | 4784 | EXPORT_SYMBOL(parent_mem_cgroup); |
33327948 | 4785 | |
c077719b KH |
4786 | #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP |
4787 | static void __init enable_swap_cgroup(void) | |
4788 | { | |
f8d66542 | 4789 | if (!mem_cgroup_disabled() && really_do_swap_account) |
c077719b KH |
4790 | do_swap_account = 1; |
4791 | } | |
4792 | #else | |
4793 | static void __init enable_swap_cgroup(void) | |
4794 | { | |
4795 | } | |
4796 | #endif | |
4797 | ||
f64c3f54 BS |
4798 | static int mem_cgroup_soft_limit_tree_init(void) |
4799 | { | |
4800 | struct mem_cgroup_tree_per_node *rtpn; | |
4801 | struct mem_cgroup_tree_per_zone *rtpz; | |
4802 | int tmp, node, zone; | |
4803 | ||
3ed28fa1 | 4804 | for_each_node(node) { |
f64c3f54 BS |
4805 | tmp = node; |
4806 | if (!node_state(node, N_NORMAL_MEMORY)) | |
4807 | tmp = -1; | |
4808 | rtpn = kzalloc_node(sizeof(*rtpn), GFP_KERNEL, tmp); | |
4809 | if (!rtpn) | |
c3cecc68 | 4810 | goto err_cleanup; |
f64c3f54 BS |
4811 | |
4812 | soft_limit_tree.rb_tree_per_node[node] = rtpn; | |
4813 | ||
4814 | for (zone = 0; zone < MAX_NR_ZONES; zone++) { | |
4815 | rtpz = &rtpn->rb_tree_per_zone[zone]; | |
4816 | rtpz->rb_root = RB_ROOT; | |
4817 | spin_lock_init(&rtpz->lock); | |
4818 | } | |
4819 | } | |
4820 | return 0; | |
c3cecc68 MH |
4821 | |
4822 | err_cleanup: | |
3ed28fa1 | 4823 | for_each_node(node) { |
c3cecc68 MH |
4824 | if (!soft_limit_tree.rb_tree_per_node[node]) |
4825 | break; | |
4826 | kfree(soft_limit_tree.rb_tree_per_node[node]); | |
4827 | soft_limit_tree.rb_tree_per_node[node] = NULL; | |
4828 | } | |
4829 | return 1; | |
4830 | ||
f64c3f54 BS |
4831 | } |
4832 | ||
0eb253e2 | 4833 | static struct cgroup_subsys_state * __ref |
761b3ef5 | 4834 | mem_cgroup_create(struct cgroup *cont) |
8cdea7c0 | 4835 | { |
c0ff4b85 | 4836 | struct mem_cgroup *memcg, *parent; |
04046e1a | 4837 | long error = -ENOMEM; |
6d12e2d8 | 4838 | int node; |
8cdea7c0 | 4839 | |
c0ff4b85 R |
4840 | memcg = mem_cgroup_alloc(); |
4841 | if (!memcg) | |
04046e1a | 4842 | return ERR_PTR(error); |
78fb7466 | 4843 | |
3ed28fa1 | 4844 | for_each_node(node) |
c0ff4b85 | 4845 | if (alloc_mem_cgroup_per_zone_info(memcg, node)) |
6d12e2d8 | 4846 | goto free_out; |
f64c3f54 | 4847 | |
c077719b | 4848 | /* root ? */ |
28dbc4b6 | 4849 | if (cont->parent == NULL) { |
cdec2e42 | 4850 | int cpu; |
c077719b | 4851 | enable_swap_cgroup(); |
28dbc4b6 | 4852 | parent = NULL; |
f64c3f54 BS |
4853 | if (mem_cgroup_soft_limit_tree_init()) |
4854 | goto free_out; | |
a41c58a6 | 4855 | root_mem_cgroup = memcg; |
cdec2e42 KH |
4856 | for_each_possible_cpu(cpu) { |
4857 | struct memcg_stock_pcp *stock = | |
4858 | &per_cpu(memcg_stock, cpu); | |
4859 | INIT_WORK(&stock->work, drain_local_stock); | |
4860 | } | |
711d3d2c | 4861 | hotcpu_notifier(memcg_cpu_hotplug_callback, 0); |
18f59ea7 | 4862 | } else { |
28dbc4b6 | 4863 | parent = mem_cgroup_from_cont(cont->parent); |
c0ff4b85 R |
4864 | memcg->use_hierarchy = parent->use_hierarchy; |
4865 | memcg->oom_kill_disable = parent->oom_kill_disable; | |
18f59ea7 | 4866 | } |
28dbc4b6 | 4867 | |
18f59ea7 | 4868 | if (parent && parent->use_hierarchy) { |
c0ff4b85 R |
4869 | res_counter_init(&memcg->res, &parent->res); |
4870 | res_counter_init(&memcg->memsw, &parent->memsw); | |
7bcc1bb1 DN |
4871 | /* |
4872 | * We increment refcnt of the parent to ensure that we can | |
4873 | * safely access it on res_counter_charge/uncharge. | |
4874 | * This refcnt will be decremented when freeing this | |
4875 | * mem_cgroup(see mem_cgroup_put). | |
4876 | */ | |
4877 | mem_cgroup_get(parent); | |
18f59ea7 | 4878 | } else { |
c0ff4b85 R |
4879 | res_counter_init(&memcg->res, NULL); |
4880 | res_counter_init(&memcg->memsw, NULL); | |
18f59ea7 | 4881 | } |
c0ff4b85 R |
4882 | memcg->last_scanned_node = MAX_NUMNODES; |
4883 | INIT_LIST_HEAD(&memcg->oom_notify); | |
6d61ef40 | 4884 | |
a7885eb8 | 4885 | if (parent) |
c0ff4b85 R |
4886 | memcg->swappiness = mem_cgroup_swappiness(parent); |
4887 | atomic_set(&memcg->refcnt, 1); | |
4888 | memcg->move_charge_at_immigrate = 0; | |
4889 | mutex_init(&memcg->thresholds_lock); | |
312734c0 | 4890 | spin_lock_init(&memcg->move_lock); |
cbe128e3 GC |
4891 | |
4892 | error = memcg_init_kmem(memcg, &mem_cgroup_subsys); | |
4893 | if (error) { | |
4894 | /* | |
4895 | * We call put now because our (and parent's) refcnts | |
4896 | * are already in place. mem_cgroup_put() will internally | |
4897 | * call __mem_cgroup_free, so return directly | |
4898 | */ | |
4899 | mem_cgroup_put(memcg); | |
4900 | return ERR_PTR(error); | |
4901 | } | |
c0ff4b85 | 4902 | return &memcg->css; |
6d12e2d8 | 4903 | free_out: |
c0ff4b85 | 4904 | __mem_cgroup_free(memcg); |
04046e1a | 4905 | return ERR_PTR(error); |
8cdea7c0 BS |
4906 | } |
4907 | ||
761b3ef5 | 4908 | static int mem_cgroup_pre_destroy(struct cgroup *cont) |
df878fb0 | 4909 | { |
c0ff4b85 | 4910 | struct mem_cgroup *memcg = mem_cgroup_from_cont(cont); |
ec64f515 | 4911 | |
c0ff4b85 | 4912 | return mem_cgroup_force_empty(memcg, false); |
df878fb0 KH |
4913 | } |
4914 | ||
761b3ef5 | 4915 | static void mem_cgroup_destroy(struct cgroup *cont) |
8cdea7c0 | 4916 | { |
c0ff4b85 | 4917 | struct mem_cgroup *memcg = mem_cgroup_from_cont(cont); |
c268e994 | 4918 | |
1d62e436 | 4919 | kmem_cgroup_destroy(memcg); |
d1a4c0b3 | 4920 | |
c0ff4b85 | 4921 | mem_cgroup_put(memcg); |
8cdea7c0 BS |
4922 | } |
4923 | ||
02491447 | 4924 | #ifdef CONFIG_MMU |
7dc74be0 | 4925 | /* Handlers for move charge at task migration. */ |
854ffa8d DN |
4926 | #define PRECHARGE_COUNT_AT_ONCE 256 |
4927 | static int mem_cgroup_do_precharge(unsigned long count) | |
7dc74be0 | 4928 | { |
854ffa8d DN |
4929 | int ret = 0; |
4930 | int batch_count = PRECHARGE_COUNT_AT_ONCE; | |
c0ff4b85 | 4931 | struct mem_cgroup *memcg = mc.to; |
4ffef5fe | 4932 | |
c0ff4b85 | 4933 | if (mem_cgroup_is_root(memcg)) { |
854ffa8d DN |
4934 | mc.precharge += count; |
4935 | /* we don't need css_get for root */ | |
4936 | return ret; | |
4937 | } | |
4938 | /* try to charge at once */ | |
4939 | if (count > 1) { | |
4940 | struct res_counter *dummy; | |
4941 | /* | |
c0ff4b85 | 4942 | * "memcg" cannot be under rmdir() because we've already checked |
854ffa8d DN |
4943 | * by cgroup_lock_live_cgroup() that it is not removed and we |
4944 | * are still under the same cgroup_mutex. So we can postpone | |
4945 | * css_get(). | |
4946 | */ | |
c0ff4b85 | 4947 | if (res_counter_charge(&memcg->res, PAGE_SIZE * count, &dummy)) |
854ffa8d | 4948 | goto one_by_one; |
c0ff4b85 | 4949 | if (do_swap_account && res_counter_charge(&memcg->memsw, |
854ffa8d | 4950 | PAGE_SIZE * count, &dummy)) { |
c0ff4b85 | 4951 | res_counter_uncharge(&memcg->res, PAGE_SIZE * count); |
854ffa8d DN |
4952 | goto one_by_one; |
4953 | } | |
4954 | mc.precharge += count; | |
854ffa8d DN |
4955 | return ret; |
4956 | } | |
4957 | one_by_one: | |
4958 | /* fall back to one by one charge */ | |
4959 | while (count--) { | |
4960 | if (signal_pending(current)) { | |
4961 | ret = -EINTR; | |
4962 | break; | |
4963 | } | |
4964 | if (!batch_count--) { | |
4965 | batch_count = PRECHARGE_COUNT_AT_ONCE; | |
4966 | cond_resched(); | |
4967 | } | |
c0ff4b85 R |
4968 | ret = __mem_cgroup_try_charge(NULL, |
4969 | GFP_KERNEL, 1, &memcg, false); | |
38c5d72f | 4970 | if (ret) |
854ffa8d | 4971 | /* mem_cgroup_clear_mc() will do uncharge later */ |
38c5d72f | 4972 | return ret; |
854ffa8d DN |
4973 | mc.precharge++; |
4974 | } | |
4ffef5fe DN |
4975 | return ret; |
4976 | } | |
4977 | ||
4978 | /** | |
8d32ff84 | 4979 | * get_mctgt_type - get target type of moving charge |
4ffef5fe DN |
4980 | * @vma: the vma the pte to be checked belongs |
4981 | * @addr: the address corresponding to the pte to be checked | |
4982 | * @ptent: the pte to be checked | |
02491447 | 4983 | * @target: the pointer the target page or swap ent will be stored(can be NULL) |
4ffef5fe DN |
4984 | * |
4985 | * Returns | |
4986 | * 0(MC_TARGET_NONE): if the pte is not a target for move charge. | |
4987 | * 1(MC_TARGET_PAGE): if the page corresponding to this pte is a target for | |
4988 | * move charge. if @target is not NULL, the page is stored in target->page | |
4989 | * with extra refcnt got(Callers should handle it). | |
02491447 DN |
4990 | * 2(MC_TARGET_SWAP): if the swap entry corresponding to this pte is a |
4991 | * target for charge migration. if @target is not NULL, the entry is stored | |
4992 | * in target->ent. | |
4ffef5fe DN |
4993 | * |
4994 | * Called with pte lock held. | |
4995 | */ | |
4ffef5fe DN |
4996 | union mc_target { |
4997 | struct page *page; | |
02491447 | 4998 | swp_entry_t ent; |
4ffef5fe DN |
4999 | }; |
5000 | ||
4ffef5fe | 5001 | enum mc_target_type { |
8d32ff84 | 5002 | MC_TARGET_NONE = 0, |
4ffef5fe | 5003 | MC_TARGET_PAGE, |
02491447 | 5004 | MC_TARGET_SWAP, |
4ffef5fe DN |
5005 | }; |
5006 | ||
90254a65 DN |
5007 | static struct page *mc_handle_present_pte(struct vm_area_struct *vma, |
5008 | unsigned long addr, pte_t ptent) | |
4ffef5fe | 5009 | { |
90254a65 | 5010 | struct page *page = vm_normal_page(vma, addr, ptent); |
4ffef5fe | 5011 | |
90254a65 DN |
5012 | if (!page || !page_mapped(page)) |
5013 | return NULL; | |
5014 | if (PageAnon(page)) { | |
5015 | /* we don't move shared anon */ | |
4b91355e | 5016 | if (!move_anon()) |
90254a65 | 5017 | return NULL; |
87946a72 DN |
5018 | } else if (!move_file()) |
5019 | /* we ignore mapcount for file pages */ | |
90254a65 DN |
5020 | return NULL; |
5021 | if (!get_page_unless_zero(page)) | |
5022 | return NULL; | |
5023 | ||
5024 | return page; | |
5025 | } | |
5026 | ||
4b91355e | 5027 | #ifdef CONFIG_SWAP |
90254a65 DN |
5028 | static struct page *mc_handle_swap_pte(struct vm_area_struct *vma, |
5029 | unsigned long addr, pte_t ptent, swp_entry_t *entry) | |
5030 | { | |
90254a65 DN |
5031 | struct page *page = NULL; |
5032 | swp_entry_t ent = pte_to_swp_entry(ptent); | |
5033 | ||
5034 | if (!move_anon() || non_swap_entry(ent)) | |
5035 | return NULL; | |
4b91355e KH |
5036 | /* |
5037 | * Because lookup_swap_cache() updates some statistics counter, | |
5038 | * we call find_get_page() with swapper_space directly. | |
5039 | */ | |
5040 | page = find_get_page(&swapper_space, ent.val); | |
90254a65 DN |
5041 | if (do_swap_account) |
5042 | entry->val = ent.val; | |
5043 | ||
5044 | return page; | |
5045 | } | |
4b91355e KH |
5046 | #else |
5047 | static struct page *mc_handle_swap_pte(struct vm_area_struct *vma, | |
5048 | unsigned long addr, pte_t ptent, swp_entry_t *entry) | |
5049 | { | |
5050 | return NULL; | |
5051 | } | |
5052 | #endif | |
90254a65 | 5053 | |
87946a72 DN |
5054 | static struct page *mc_handle_file_pte(struct vm_area_struct *vma, |
5055 | unsigned long addr, pte_t ptent, swp_entry_t *entry) | |
5056 | { | |
5057 | struct page *page = NULL; | |
87946a72 DN |
5058 | struct address_space *mapping; |
5059 | pgoff_t pgoff; | |
5060 | ||
5061 | if (!vma->vm_file) /* anonymous vma */ | |
5062 | return NULL; | |
5063 | if (!move_file()) | |
5064 | return NULL; | |
5065 | ||
87946a72 DN |
5066 | mapping = vma->vm_file->f_mapping; |
5067 | if (pte_none(ptent)) | |
5068 | pgoff = linear_page_index(vma, addr); | |
5069 | else /* pte_file(ptent) is true */ | |
5070 | pgoff = pte_to_pgoff(ptent); | |
5071 | ||
5072 | /* page is moved even if it's not RSS of this task(page-faulted). */ | |
aa3b1895 HD |
5073 | page = find_get_page(mapping, pgoff); |
5074 | ||
5075 | #ifdef CONFIG_SWAP | |
5076 | /* shmem/tmpfs may report page out on swap: account for that too. */ | |
5077 | if (radix_tree_exceptional_entry(page)) { | |
5078 | swp_entry_t swap = radix_to_swp_entry(page); | |
87946a72 | 5079 | if (do_swap_account) |
aa3b1895 HD |
5080 | *entry = swap; |
5081 | page = find_get_page(&swapper_space, swap.val); | |
87946a72 | 5082 | } |
aa3b1895 | 5083 | #endif |
87946a72 DN |
5084 | return page; |
5085 | } | |
5086 | ||
8d32ff84 | 5087 | static enum mc_target_type get_mctgt_type(struct vm_area_struct *vma, |
90254a65 DN |
5088 | unsigned long addr, pte_t ptent, union mc_target *target) |
5089 | { | |
5090 | struct page *page = NULL; | |
5091 | struct page_cgroup *pc; | |
8d32ff84 | 5092 | enum mc_target_type ret = MC_TARGET_NONE; |
90254a65 DN |
5093 | swp_entry_t ent = { .val = 0 }; |
5094 | ||
5095 | if (pte_present(ptent)) | |
5096 | page = mc_handle_present_pte(vma, addr, ptent); | |
5097 | else if (is_swap_pte(ptent)) | |
5098 | page = mc_handle_swap_pte(vma, addr, ptent, &ent); | |
87946a72 DN |
5099 | else if (pte_none(ptent) || pte_file(ptent)) |
5100 | page = mc_handle_file_pte(vma, addr, ptent, &ent); | |
90254a65 DN |
5101 | |
5102 | if (!page && !ent.val) | |
8d32ff84 | 5103 | return ret; |
02491447 DN |
5104 | if (page) { |
5105 | pc = lookup_page_cgroup(page); | |
5106 | /* | |
5107 | * Do only loose check w/o page_cgroup lock. | |
5108 | * mem_cgroup_move_account() checks the pc is valid or not under | |
5109 | * the lock. | |
5110 | */ | |
5111 | if (PageCgroupUsed(pc) && pc->mem_cgroup == mc.from) { | |
5112 | ret = MC_TARGET_PAGE; | |
5113 | if (target) | |
5114 | target->page = page; | |
5115 | } | |
5116 | if (!ret || !target) | |
5117 | put_page(page); | |
5118 | } | |
90254a65 DN |
5119 | /* There is a swap entry and a page doesn't exist or isn't charged */ |
5120 | if (ent.val && !ret && | |
9fb4b7cc | 5121 | css_id(&mc.from->css) == lookup_swap_cgroup_id(ent)) { |
7f0f1546 KH |
5122 | ret = MC_TARGET_SWAP; |
5123 | if (target) | |
5124 | target->ent = ent; | |
4ffef5fe | 5125 | } |
4ffef5fe DN |
5126 | return ret; |
5127 | } | |
5128 | ||
12724850 NH |
5129 | #ifdef CONFIG_TRANSPARENT_HUGEPAGE |
5130 | /* | |
5131 | * We don't consider swapping or file mapped pages because THP does not | |
5132 | * support them for now. | |
5133 | * Caller should make sure that pmd_trans_huge(pmd) is true. | |
5134 | */ | |
5135 | static enum mc_target_type get_mctgt_type_thp(struct vm_area_struct *vma, | |
5136 | unsigned long addr, pmd_t pmd, union mc_target *target) | |
5137 | { | |
5138 | struct page *page = NULL; | |
5139 | struct page_cgroup *pc; | |
5140 | enum mc_target_type ret = MC_TARGET_NONE; | |
5141 | ||
5142 | page = pmd_page(pmd); | |
5143 | VM_BUG_ON(!page || !PageHead(page)); | |
5144 | if (!move_anon()) | |
5145 | return ret; | |
5146 | pc = lookup_page_cgroup(page); | |
5147 | if (PageCgroupUsed(pc) && pc->mem_cgroup == mc.from) { | |
5148 | ret = MC_TARGET_PAGE; | |
5149 | if (target) { | |
5150 | get_page(page); | |
5151 | target->page = page; | |
5152 | } | |
5153 | } | |
5154 | return ret; | |
5155 | } | |
5156 | #else | |
5157 | static inline enum mc_target_type get_mctgt_type_thp(struct vm_area_struct *vma, | |
5158 | unsigned long addr, pmd_t pmd, union mc_target *target) | |
5159 | { | |
5160 | return MC_TARGET_NONE; | |
5161 | } | |
5162 | #endif | |
5163 | ||
4ffef5fe DN |
5164 | static int mem_cgroup_count_precharge_pte_range(pmd_t *pmd, |
5165 | unsigned long addr, unsigned long end, | |
5166 | struct mm_walk *walk) | |
5167 | { | |
5168 | struct vm_area_struct *vma = walk->private; | |
5169 | pte_t *pte; | |
5170 | spinlock_t *ptl; | |
5171 | ||
12724850 NH |
5172 | if (pmd_trans_huge_lock(pmd, vma) == 1) { |
5173 | if (get_mctgt_type_thp(vma, addr, *pmd, NULL) == MC_TARGET_PAGE) | |
5174 | mc.precharge += HPAGE_PMD_NR; | |
5175 | spin_unlock(&vma->vm_mm->page_table_lock); | |
1a5a9906 | 5176 | return 0; |
12724850 | 5177 | } |
03319327 | 5178 | |
45f83cef AA |
5179 | if (pmd_trans_unstable(pmd)) |
5180 | return 0; | |
4ffef5fe DN |
5181 | pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl); |
5182 | for (; addr != end; pte++, addr += PAGE_SIZE) | |
8d32ff84 | 5183 | if (get_mctgt_type(vma, addr, *pte, NULL)) |
4ffef5fe DN |
5184 | mc.precharge++; /* increment precharge temporarily */ |
5185 | pte_unmap_unlock(pte - 1, ptl); | |
5186 | cond_resched(); | |
5187 | ||
7dc74be0 DN |
5188 | return 0; |
5189 | } | |
5190 | ||
4ffef5fe DN |
5191 | static unsigned long mem_cgroup_count_precharge(struct mm_struct *mm) |
5192 | { | |
5193 | unsigned long precharge; | |
5194 | struct vm_area_struct *vma; | |
5195 | ||
dfe076b0 | 5196 | down_read(&mm->mmap_sem); |
4ffef5fe DN |
5197 | for (vma = mm->mmap; vma; vma = vma->vm_next) { |
5198 | struct mm_walk mem_cgroup_count_precharge_walk = { | |
5199 | .pmd_entry = mem_cgroup_count_precharge_pte_range, | |
5200 | .mm = mm, | |
5201 | .private = vma, | |
5202 | }; | |
5203 | if (is_vm_hugetlb_page(vma)) | |
5204 | continue; | |
4ffef5fe DN |
5205 | walk_page_range(vma->vm_start, vma->vm_end, |
5206 | &mem_cgroup_count_precharge_walk); | |
5207 | } | |
dfe076b0 | 5208 | up_read(&mm->mmap_sem); |
4ffef5fe DN |
5209 | |
5210 | precharge = mc.precharge; | |
5211 | mc.precharge = 0; | |
5212 | ||
5213 | return precharge; | |
5214 | } | |
5215 | ||
4ffef5fe DN |
5216 | static int mem_cgroup_precharge_mc(struct mm_struct *mm) |
5217 | { | |
dfe076b0 DN |
5218 | unsigned long precharge = mem_cgroup_count_precharge(mm); |
5219 | ||
5220 | VM_BUG_ON(mc.moving_task); | |
5221 | mc.moving_task = current; | |
5222 | return mem_cgroup_do_precharge(precharge); | |
4ffef5fe DN |
5223 | } |
5224 | ||
dfe076b0 DN |
5225 | /* cancels all extra charges on mc.from and mc.to, and wakes up all waiters. */ |
5226 | static void __mem_cgroup_clear_mc(void) | |
4ffef5fe | 5227 | { |
2bd9bb20 KH |
5228 | struct mem_cgroup *from = mc.from; |
5229 | struct mem_cgroup *to = mc.to; | |
5230 | ||
4ffef5fe | 5231 | /* we must uncharge all the leftover precharges from mc.to */ |
854ffa8d DN |
5232 | if (mc.precharge) { |
5233 | __mem_cgroup_cancel_charge(mc.to, mc.precharge); | |
5234 | mc.precharge = 0; | |
5235 | } | |
5236 | /* | |
5237 | * we didn't uncharge from mc.from at mem_cgroup_move_account(), so | |
5238 | * we must uncharge here. | |
5239 | */ | |
5240 | if (mc.moved_charge) { | |
5241 | __mem_cgroup_cancel_charge(mc.from, mc.moved_charge); | |
5242 | mc.moved_charge = 0; | |
4ffef5fe | 5243 | } |
483c30b5 DN |
5244 | /* we must fixup refcnts and charges */ |
5245 | if (mc.moved_swap) { | |
483c30b5 DN |
5246 | /* uncharge swap account from the old cgroup */ |
5247 | if (!mem_cgroup_is_root(mc.from)) | |
5248 | res_counter_uncharge(&mc.from->memsw, | |
5249 | PAGE_SIZE * mc.moved_swap); | |
5250 | __mem_cgroup_put(mc.from, mc.moved_swap); | |
5251 | ||
5252 | if (!mem_cgroup_is_root(mc.to)) { | |
5253 | /* | |
5254 | * we charged both to->res and to->memsw, so we should | |
5255 | * uncharge to->res. | |
5256 | */ | |
5257 | res_counter_uncharge(&mc.to->res, | |
5258 | PAGE_SIZE * mc.moved_swap); | |
483c30b5 DN |
5259 | } |
5260 | /* we've already done mem_cgroup_get(mc.to) */ | |
483c30b5 DN |
5261 | mc.moved_swap = 0; |
5262 | } | |
dfe076b0 DN |
5263 | memcg_oom_recover(from); |
5264 | memcg_oom_recover(to); | |
5265 | wake_up_all(&mc.waitq); | |
5266 | } | |
5267 | ||
5268 | static void mem_cgroup_clear_mc(void) | |
5269 | { | |
5270 | struct mem_cgroup *from = mc.from; | |
5271 | ||
5272 | /* | |
5273 | * we must clear moving_task before waking up waiters at the end of | |
5274 | * task migration. | |
5275 | */ | |
5276 | mc.moving_task = NULL; | |
5277 | __mem_cgroup_clear_mc(); | |
2bd9bb20 | 5278 | spin_lock(&mc.lock); |
4ffef5fe DN |
5279 | mc.from = NULL; |
5280 | mc.to = NULL; | |
2bd9bb20 | 5281 | spin_unlock(&mc.lock); |
32047e2a | 5282 | mem_cgroup_end_move(from); |
4ffef5fe DN |
5283 | } |
5284 | ||
761b3ef5 LZ |
5285 | static int mem_cgroup_can_attach(struct cgroup *cgroup, |
5286 | struct cgroup_taskset *tset) | |
7dc74be0 | 5287 | { |
2f7ee569 | 5288 | struct task_struct *p = cgroup_taskset_first(tset); |
7dc74be0 | 5289 | int ret = 0; |
c0ff4b85 | 5290 | struct mem_cgroup *memcg = mem_cgroup_from_cont(cgroup); |
7dc74be0 | 5291 | |
c0ff4b85 | 5292 | if (memcg->move_charge_at_immigrate) { |
7dc74be0 DN |
5293 | struct mm_struct *mm; |
5294 | struct mem_cgroup *from = mem_cgroup_from_task(p); | |
5295 | ||
c0ff4b85 | 5296 | VM_BUG_ON(from == memcg); |
7dc74be0 DN |
5297 | |
5298 | mm = get_task_mm(p); | |
5299 | if (!mm) | |
5300 | return 0; | |
7dc74be0 | 5301 | /* We move charges only when we move a owner of the mm */ |
4ffef5fe DN |
5302 | if (mm->owner == p) { |
5303 | VM_BUG_ON(mc.from); | |
5304 | VM_BUG_ON(mc.to); | |
5305 | VM_BUG_ON(mc.precharge); | |
854ffa8d | 5306 | VM_BUG_ON(mc.moved_charge); |
483c30b5 | 5307 | VM_BUG_ON(mc.moved_swap); |
32047e2a | 5308 | mem_cgroup_start_move(from); |
2bd9bb20 | 5309 | spin_lock(&mc.lock); |
4ffef5fe | 5310 | mc.from = from; |
c0ff4b85 | 5311 | mc.to = memcg; |
2bd9bb20 | 5312 | spin_unlock(&mc.lock); |
dfe076b0 | 5313 | /* We set mc.moving_task later */ |
4ffef5fe DN |
5314 | |
5315 | ret = mem_cgroup_precharge_mc(mm); | |
5316 | if (ret) | |
5317 | mem_cgroup_clear_mc(); | |
dfe076b0 DN |
5318 | } |
5319 | mmput(mm); | |
7dc74be0 DN |
5320 | } |
5321 | return ret; | |
5322 | } | |
5323 | ||
761b3ef5 LZ |
5324 | static void mem_cgroup_cancel_attach(struct cgroup *cgroup, |
5325 | struct cgroup_taskset *tset) | |
7dc74be0 | 5326 | { |
4ffef5fe | 5327 | mem_cgroup_clear_mc(); |
7dc74be0 DN |
5328 | } |
5329 | ||
4ffef5fe DN |
5330 | static int mem_cgroup_move_charge_pte_range(pmd_t *pmd, |
5331 | unsigned long addr, unsigned long end, | |
5332 | struct mm_walk *walk) | |
7dc74be0 | 5333 | { |
4ffef5fe DN |
5334 | int ret = 0; |
5335 | struct vm_area_struct *vma = walk->private; | |
5336 | pte_t *pte; | |
5337 | spinlock_t *ptl; | |
12724850 NH |
5338 | enum mc_target_type target_type; |
5339 | union mc_target target; | |
5340 | struct page *page; | |
5341 | struct page_cgroup *pc; | |
4ffef5fe | 5342 | |
12724850 NH |
5343 | /* |
5344 | * We don't take compound_lock() here but no race with splitting thp | |
5345 | * happens because: | |
5346 | * - if pmd_trans_huge_lock() returns 1, the relevant thp is not | |
5347 | * under splitting, which means there's no concurrent thp split, | |
5348 | * - if another thread runs into split_huge_page() just after we | |
5349 | * entered this if-block, the thread must wait for page table lock | |
5350 | * to be unlocked in __split_huge_page_splitting(), where the main | |
5351 | * part of thp split is not executed yet. | |
5352 | */ | |
5353 | if (pmd_trans_huge_lock(pmd, vma) == 1) { | |
62ade86a | 5354 | if (mc.precharge < HPAGE_PMD_NR) { |
12724850 NH |
5355 | spin_unlock(&vma->vm_mm->page_table_lock); |
5356 | return 0; | |
5357 | } | |
5358 | target_type = get_mctgt_type_thp(vma, addr, *pmd, &target); | |
5359 | if (target_type == MC_TARGET_PAGE) { | |
5360 | page = target.page; | |
5361 | if (!isolate_lru_page(page)) { | |
5362 | pc = lookup_page_cgroup(page); | |
5363 | if (!mem_cgroup_move_account(page, HPAGE_PMD_NR, | |
2f3479b1 | 5364 | pc, mc.from, mc.to)) { |
12724850 NH |
5365 | mc.precharge -= HPAGE_PMD_NR; |
5366 | mc.moved_charge += HPAGE_PMD_NR; | |
5367 | } | |
5368 | putback_lru_page(page); | |
5369 | } | |
5370 | put_page(page); | |
5371 | } | |
5372 | spin_unlock(&vma->vm_mm->page_table_lock); | |
1a5a9906 | 5373 | return 0; |
12724850 NH |
5374 | } |
5375 | ||
45f83cef AA |
5376 | if (pmd_trans_unstable(pmd)) |
5377 | return 0; | |
4ffef5fe DN |
5378 | retry: |
5379 | pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl); | |
5380 | for (; addr != end; addr += PAGE_SIZE) { | |
5381 | pte_t ptent = *(pte++); | |
02491447 | 5382 | swp_entry_t ent; |
4ffef5fe DN |
5383 | |
5384 | if (!mc.precharge) | |
5385 | break; | |
5386 | ||
8d32ff84 | 5387 | switch (get_mctgt_type(vma, addr, ptent, &target)) { |
4ffef5fe DN |
5388 | case MC_TARGET_PAGE: |
5389 | page = target.page; | |
5390 | if (isolate_lru_page(page)) | |
5391 | goto put; | |
5392 | pc = lookup_page_cgroup(page); | |
7ec99d62 | 5393 | if (!mem_cgroup_move_account(page, 1, pc, |
2f3479b1 | 5394 | mc.from, mc.to)) { |
4ffef5fe | 5395 | mc.precharge--; |
854ffa8d DN |
5396 | /* we uncharge from mc.from later. */ |
5397 | mc.moved_charge++; | |
4ffef5fe DN |
5398 | } |
5399 | putback_lru_page(page); | |
8d32ff84 | 5400 | put: /* get_mctgt_type() gets the page */ |
4ffef5fe DN |
5401 | put_page(page); |
5402 | break; | |
02491447 DN |
5403 | case MC_TARGET_SWAP: |
5404 | ent = target.ent; | |
e91cbb42 | 5405 | if (!mem_cgroup_move_swap_account(ent, mc.from, mc.to)) { |
02491447 | 5406 | mc.precharge--; |
483c30b5 DN |
5407 | /* we fixup refcnts and charges later. */ |
5408 | mc.moved_swap++; | |
5409 | } | |
02491447 | 5410 | break; |
4ffef5fe DN |
5411 | default: |
5412 | break; | |
5413 | } | |
5414 | } | |
5415 | pte_unmap_unlock(pte - 1, ptl); | |
5416 | cond_resched(); | |
5417 | ||
5418 | if (addr != end) { | |
5419 | /* | |
5420 | * We have consumed all precharges we got in can_attach(). | |
5421 | * We try charge one by one, but don't do any additional | |
5422 | * charges to mc.to if we have failed in charge once in attach() | |
5423 | * phase. | |
5424 | */ | |
854ffa8d | 5425 | ret = mem_cgroup_do_precharge(1); |
4ffef5fe DN |
5426 | if (!ret) |
5427 | goto retry; | |
5428 | } | |
5429 | ||
5430 | return ret; | |
5431 | } | |
5432 | ||
5433 | static void mem_cgroup_move_charge(struct mm_struct *mm) | |
5434 | { | |
5435 | struct vm_area_struct *vma; | |
5436 | ||
5437 | lru_add_drain_all(); | |
dfe076b0 DN |
5438 | retry: |
5439 | if (unlikely(!down_read_trylock(&mm->mmap_sem))) { | |
5440 | /* | |
5441 | * Someone who are holding the mmap_sem might be waiting in | |
5442 | * waitq. So we cancel all extra charges, wake up all waiters, | |
5443 | * and retry. Because we cancel precharges, we might not be able | |
5444 | * to move enough charges, but moving charge is a best-effort | |
5445 | * feature anyway, so it wouldn't be a big problem. | |
5446 | */ | |
5447 | __mem_cgroup_clear_mc(); | |
5448 | cond_resched(); | |
5449 | goto retry; | |
5450 | } | |
4ffef5fe DN |
5451 | for (vma = mm->mmap; vma; vma = vma->vm_next) { |
5452 | int ret; | |
5453 | struct mm_walk mem_cgroup_move_charge_walk = { | |
5454 | .pmd_entry = mem_cgroup_move_charge_pte_range, | |
5455 | .mm = mm, | |
5456 | .private = vma, | |
5457 | }; | |
5458 | if (is_vm_hugetlb_page(vma)) | |
5459 | continue; | |
4ffef5fe DN |
5460 | ret = walk_page_range(vma->vm_start, vma->vm_end, |
5461 | &mem_cgroup_move_charge_walk); | |
5462 | if (ret) | |
5463 | /* | |
5464 | * means we have consumed all precharges and failed in | |
5465 | * doing additional charge. Just abandon here. | |
5466 | */ | |
5467 | break; | |
5468 | } | |
dfe076b0 | 5469 | up_read(&mm->mmap_sem); |
7dc74be0 DN |
5470 | } |
5471 | ||
761b3ef5 LZ |
5472 | static void mem_cgroup_move_task(struct cgroup *cont, |
5473 | struct cgroup_taskset *tset) | |
67e465a7 | 5474 | { |
2f7ee569 | 5475 | struct task_struct *p = cgroup_taskset_first(tset); |
a433658c | 5476 | struct mm_struct *mm = get_task_mm(p); |
dfe076b0 | 5477 | |
dfe076b0 | 5478 | if (mm) { |
a433658c KM |
5479 | if (mc.to) |
5480 | mem_cgroup_move_charge(mm); | |
dfe076b0 DN |
5481 | mmput(mm); |
5482 | } | |
a433658c KM |
5483 | if (mc.to) |
5484 | mem_cgroup_clear_mc(); | |
67e465a7 | 5485 | } |
5cfb80a7 | 5486 | #else /* !CONFIG_MMU */ |
761b3ef5 LZ |
5487 | static int mem_cgroup_can_attach(struct cgroup *cgroup, |
5488 | struct cgroup_taskset *tset) | |
5cfb80a7 DN |
5489 | { |
5490 | return 0; | |
5491 | } | |
761b3ef5 LZ |
5492 | static void mem_cgroup_cancel_attach(struct cgroup *cgroup, |
5493 | struct cgroup_taskset *tset) | |
5cfb80a7 DN |
5494 | { |
5495 | } | |
761b3ef5 LZ |
5496 | static void mem_cgroup_move_task(struct cgroup *cont, |
5497 | struct cgroup_taskset *tset) | |
5cfb80a7 DN |
5498 | { |
5499 | } | |
5500 | #endif | |
67e465a7 | 5501 | |
8cdea7c0 BS |
5502 | struct cgroup_subsys mem_cgroup_subsys = { |
5503 | .name = "memory", | |
5504 | .subsys_id = mem_cgroup_subsys_id, | |
5505 | .create = mem_cgroup_create, | |
df878fb0 | 5506 | .pre_destroy = mem_cgroup_pre_destroy, |
8cdea7c0 | 5507 | .destroy = mem_cgroup_destroy, |
7dc74be0 DN |
5508 | .can_attach = mem_cgroup_can_attach, |
5509 | .cancel_attach = mem_cgroup_cancel_attach, | |
67e465a7 | 5510 | .attach = mem_cgroup_move_task, |
6bc10349 | 5511 | .base_cftypes = mem_cgroup_files, |
6d12e2d8 | 5512 | .early_init = 0, |
04046e1a | 5513 | .use_id = 1, |
48ddbe19 | 5514 | .__DEPRECATED_clear_css_refs = true, |
8cdea7c0 | 5515 | }; |
c077719b KH |
5516 | |
5517 | #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP | |
a42c390c MH |
5518 | static int __init enable_swap_account(char *s) |
5519 | { | |
5520 | /* consider enabled if no parameter or 1 is given */ | |
a2c8990a | 5521 | if (!strcmp(s, "1")) |
a42c390c | 5522 | really_do_swap_account = 1; |
a2c8990a | 5523 | else if (!strcmp(s, "0")) |
a42c390c MH |
5524 | really_do_swap_account = 0; |
5525 | return 1; | |
5526 | } | |
a2c8990a | 5527 | __setup("swapaccount=", enable_swap_account); |
c077719b | 5528 | |
c077719b | 5529 | #endif |