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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 | 53 | #include <net/sock.h> |
4bd2c1ee | 54 | #include <net/ip.h> |
d1a4c0b3 | 55 | #include <net/tcp_memcontrol.h> |
8cdea7c0 | 56 | |
8697d331 BS |
57 | #include <asm/uaccess.h> |
58 | ||
cc8e970c KM |
59 | #include <trace/events/vmscan.h> |
60 | ||
a181b0e8 | 61 | struct cgroup_subsys mem_cgroup_subsys __read_mostly; |
a181b0e8 | 62 | #define MEM_CGROUP_RECLAIM_RETRIES 5 |
6bbda35c | 63 | static struct mem_cgroup *root_mem_cgroup __read_mostly; |
8cdea7c0 | 64 | |
c255a458 | 65 | #ifdef CONFIG_MEMCG_SWAP |
338c8431 | 66 | /* Turned on only when memory cgroup is enabled && really_do_swap_account = 1 */ |
c077719b | 67 | int do_swap_account __read_mostly; |
a42c390c MH |
68 | |
69 | /* for remember boot option*/ | |
c255a458 | 70 | #ifdef CONFIG_MEMCG_SWAP_ENABLED |
a42c390c MH |
71 | static int really_do_swap_account __initdata = 1; |
72 | #else | |
73 | static int really_do_swap_account __initdata = 0; | |
74 | #endif | |
75 | ||
c077719b | 76 | #else |
a0db00fc | 77 | #define do_swap_account 0 |
c077719b KH |
78 | #endif |
79 | ||
80 | ||
d52aa412 KH |
81 | /* |
82 | * Statistics for memory cgroup. | |
83 | */ | |
84 | enum mem_cgroup_stat_index { | |
85 | /* | |
86 | * For MEM_CONTAINER_TYPE_ALL, usage = pagecache + rss. | |
87 | */ | |
88 | MEM_CGROUP_STAT_CACHE, /* # of pages charged as cache */ | |
d69b042f | 89 | MEM_CGROUP_STAT_RSS, /* # of pages charged as anon rss */ |
d8046582 | 90 | MEM_CGROUP_STAT_FILE_MAPPED, /* # of pages charged as file rss */ |
bff6bb83 | 91 | MEM_CGROUP_STAT_SWAP, /* # of pages, swapped out */ |
d52aa412 KH |
92 | MEM_CGROUP_STAT_NSTATS, |
93 | }; | |
94 | ||
af7c4b0e JW |
95 | static const char * const mem_cgroup_stat_names[] = { |
96 | "cache", | |
97 | "rss", | |
98 | "mapped_file", | |
99 | "swap", | |
100 | }; | |
101 | ||
e9f8974f JW |
102 | enum mem_cgroup_events_index { |
103 | MEM_CGROUP_EVENTS_PGPGIN, /* # of pages paged in */ | |
104 | MEM_CGROUP_EVENTS_PGPGOUT, /* # of pages paged out */ | |
456f998e YH |
105 | MEM_CGROUP_EVENTS_PGFAULT, /* # of page-faults */ |
106 | MEM_CGROUP_EVENTS_PGMAJFAULT, /* # of major page-faults */ | |
e9f8974f JW |
107 | MEM_CGROUP_EVENTS_NSTATS, |
108 | }; | |
af7c4b0e JW |
109 | |
110 | static const char * const mem_cgroup_events_names[] = { | |
111 | "pgpgin", | |
112 | "pgpgout", | |
113 | "pgfault", | |
114 | "pgmajfault", | |
115 | }; | |
116 | ||
7a159cc9 JW |
117 | /* |
118 | * Per memcg event counter is incremented at every pagein/pageout. With THP, | |
119 | * it will be incremated by the number of pages. This counter is used for | |
120 | * for trigger some periodic events. This is straightforward and better | |
121 | * than using jiffies etc. to handle periodic memcg event. | |
122 | */ | |
123 | enum mem_cgroup_events_target { | |
124 | MEM_CGROUP_TARGET_THRESH, | |
125 | MEM_CGROUP_TARGET_SOFTLIMIT, | |
453a9bf3 | 126 | MEM_CGROUP_TARGET_NUMAINFO, |
7a159cc9 JW |
127 | MEM_CGROUP_NTARGETS, |
128 | }; | |
a0db00fc KS |
129 | #define THRESHOLDS_EVENTS_TARGET 128 |
130 | #define SOFTLIMIT_EVENTS_TARGET 1024 | |
131 | #define NUMAINFO_EVENTS_TARGET 1024 | |
e9f8974f | 132 | |
d52aa412 | 133 | struct mem_cgroup_stat_cpu { |
7a159cc9 | 134 | long count[MEM_CGROUP_STAT_NSTATS]; |
e9f8974f | 135 | unsigned long events[MEM_CGROUP_EVENTS_NSTATS]; |
13114716 | 136 | unsigned long nr_page_events; |
7a159cc9 | 137 | unsigned long targets[MEM_CGROUP_NTARGETS]; |
d52aa412 KH |
138 | }; |
139 | ||
527a5ec9 JW |
140 | struct mem_cgroup_reclaim_iter { |
141 | /* css_id of the last scanned hierarchy member */ | |
142 | int position; | |
143 | /* scan generation, increased every round-trip */ | |
144 | unsigned int generation; | |
145 | }; | |
146 | ||
6d12e2d8 KH |
147 | /* |
148 | * per-zone information in memory controller. | |
149 | */ | |
6d12e2d8 | 150 | struct mem_cgroup_per_zone { |
6290df54 | 151 | struct lruvec lruvec; |
1eb49272 | 152 | unsigned long lru_size[NR_LRU_LISTS]; |
3e2f41f1 | 153 | |
527a5ec9 JW |
154 | struct mem_cgroup_reclaim_iter reclaim_iter[DEF_PRIORITY + 1]; |
155 | ||
f64c3f54 BS |
156 | struct rb_node tree_node; /* RB tree node */ |
157 | unsigned long long usage_in_excess;/* Set to the value by which */ | |
158 | /* the soft limit is exceeded*/ | |
159 | bool on_tree; | |
d79154bb | 160 | struct mem_cgroup *memcg; /* Back pointer, we cannot */ |
4e416953 | 161 | /* use container_of */ |
6d12e2d8 | 162 | }; |
6d12e2d8 KH |
163 | |
164 | struct mem_cgroup_per_node { | |
165 | struct mem_cgroup_per_zone zoneinfo[MAX_NR_ZONES]; | |
166 | }; | |
167 | ||
168 | struct mem_cgroup_lru_info { | |
169 | struct mem_cgroup_per_node *nodeinfo[MAX_NUMNODES]; | |
170 | }; | |
171 | ||
f64c3f54 BS |
172 | /* |
173 | * Cgroups above their limits are maintained in a RB-Tree, independent of | |
174 | * their hierarchy representation | |
175 | */ | |
176 | ||
177 | struct mem_cgroup_tree_per_zone { | |
178 | struct rb_root rb_root; | |
179 | spinlock_t lock; | |
180 | }; | |
181 | ||
182 | struct mem_cgroup_tree_per_node { | |
183 | struct mem_cgroup_tree_per_zone rb_tree_per_zone[MAX_NR_ZONES]; | |
184 | }; | |
185 | ||
186 | struct mem_cgroup_tree { | |
187 | struct mem_cgroup_tree_per_node *rb_tree_per_node[MAX_NUMNODES]; | |
188 | }; | |
189 | ||
190 | static struct mem_cgroup_tree soft_limit_tree __read_mostly; | |
191 | ||
2e72b634 KS |
192 | struct mem_cgroup_threshold { |
193 | struct eventfd_ctx *eventfd; | |
194 | u64 threshold; | |
195 | }; | |
196 | ||
9490ff27 | 197 | /* For threshold */ |
2e72b634 | 198 | struct mem_cgroup_threshold_ary { |
748dad36 | 199 | /* An array index points to threshold just below or equal to usage. */ |
5407a562 | 200 | int current_threshold; |
2e72b634 KS |
201 | /* Size of entries[] */ |
202 | unsigned int size; | |
203 | /* Array of thresholds */ | |
204 | struct mem_cgroup_threshold entries[0]; | |
205 | }; | |
2c488db2 KS |
206 | |
207 | struct mem_cgroup_thresholds { | |
208 | /* Primary thresholds array */ | |
209 | struct mem_cgroup_threshold_ary *primary; | |
210 | /* | |
211 | * Spare threshold array. | |
212 | * This is needed to make mem_cgroup_unregister_event() "never fail". | |
213 | * It must be able to store at least primary->size - 1 entries. | |
214 | */ | |
215 | struct mem_cgroup_threshold_ary *spare; | |
216 | }; | |
217 | ||
9490ff27 KH |
218 | /* for OOM */ |
219 | struct mem_cgroup_eventfd_list { | |
220 | struct list_head list; | |
221 | struct eventfd_ctx *eventfd; | |
222 | }; | |
2e72b634 | 223 | |
c0ff4b85 R |
224 | static void mem_cgroup_threshold(struct mem_cgroup *memcg); |
225 | static void mem_cgroup_oom_notify(struct mem_cgroup *memcg); | |
2e72b634 | 226 | |
8cdea7c0 BS |
227 | /* |
228 | * The memory controller data structure. The memory controller controls both | |
229 | * page cache and RSS per cgroup. We would eventually like to provide | |
230 | * statistics based on the statistics developed by Rik Van Riel for clock-pro, | |
231 | * to help the administrator determine what knobs to tune. | |
232 | * | |
233 | * TODO: Add a water mark for the memory controller. Reclaim will begin when | |
8a9f3ccd BS |
234 | * we hit the water mark. May be even add a low water mark, such that |
235 | * no reclaim occurs from a cgroup at it's low water mark, this is | |
236 | * a feature that will be implemented much later in the future. | |
8cdea7c0 BS |
237 | */ |
238 | struct mem_cgroup { | |
239 | struct cgroup_subsys_state css; | |
240 | /* | |
241 | * the counter to account for memory usage | |
242 | */ | |
243 | struct res_counter res; | |
59927fb9 HD |
244 | |
245 | union { | |
246 | /* | |
247 | * the counter to account for mem+swap usage. | |
248 | */ | |
249 | struct res_counter memsw; | |
250 | ||
251 | /* | |
252 | * rcu_freeing is used only when freeing struct mem_cgroup, | |
253 | * so put it into a union to avoid wasting more memory. | |
254 | * It must be disjoint from the css field. It could be | |
255 | * in a union with the res field, but res plays a much | |
256 | * larger part in mem_cgroup life than memsw, and might | |
257 | * be of interest, even at time of free, when debugging. | |
258 | * So share rcu_head with the less interesting memsw. | |
259 | */ | |
260 | struct rcu_head rcu_freeing; | |
261 | /* | |
3afe36b1 GC |
262 | * We also need some space for a worker in deferred freeing. |
263 | * By the time we call it, rcu_freeing is no longer in use. | |
59927fb9 HD |
264 | */ |
265 | struct work_struct work_freeing; | |
266 | }; | |
267 | ||
78fb7466 PE |
268 | /* |
269 | * Per cgroup active and inactive list, similar to the | |
270 | * per zone LRU lists. | |
78fb7466 | 271 | */ |
6d12e2d8 | 272 | struct mem_cgroup_lru_info info; |
889976db YH |
273 | int last_scanned_node; |
274 | #if MAX_NUMNODES > 1 | |
275 | nodemask_t scan_nodes; | |
453a9bf3 KH |
276 | atomic_t numainfo_events; |
277 | atomic_t numainfo_updating; | |
889976db | 278 | #endif |
18f59ea7 BS |
279 | /* |
280 | * Should the accounting and control be hierarchical, per subtree? | |
281 | */ | |
282 | bool use_hierarchy; | |
79dfdacc MH |
283 | |
284 | bool oom_lock; | |
285 | atomic_t under_oom; | |
286 | ||
8c7c6e34 | 287 | atomic_t refcnt; |
14797e23 | 288 | |
1f4c025b | 289 | int swappiness; |
3c11ecf4 KH |
290 | /* OOM-Killer disable */ |
291 | int oom_kill_disable; | |
a7885eb8 | 292 | |
22a668d7 KH |
293 | /* set when res.limit == memsw.limit */ |
294 | bool memsw_is_minimum; | |
295 | ||
2e72b634 KS |
296 | /* protect arrays of thresholds */ |
297 | struct mutex thresholds_lock; | |
298 | ||
299 | /* thresholds for memory usage. RCU-protected */ | |
2c488db2 | 300 | struct mem_cgroup_thresholds thresholds; |
907860ed | 301 | |
2e72b634 | 302 | /* thresholds for mem+swap usage. RCU-protected */ |
2c488db2 | 303 | struct mem_cgroup_thresholds memsw_thresholds; |
907860ed | 304 | |
9490ff27 KH |
305 | /* For oom notifier event fd */ |
306 | struct list_head oom_notify; | |
185efc0f | 307 | |
7dc74be0 DN |
308 | /* |
309 | * Should we move charges of a task when a task is moved into this | |
310 | * mem_cgroup ? And what type of charges should we move ? | |
311 | */ | |
312 | unsigned long move_charge_at_immigrate; | |
619d094b KH |
313 | /* |
314 | * set > 0 if pages under this cgroup are moving to other cgroup. | |
315 | */ | |
316 | atomic_t moving_account; | |
312734c0 KH |
317 | /* taken only while moving_account > 0 */ |
318 | spinlock_t move_lock; | |
d52aa412 | 319 | /* |
c62b1a3b | 320 | * percpu counter. |
d52aa412 | 321 | */ |
3a7951b4 | 322 | struct mem_cgroup_stat_cpu __percpu *stat; |
711d3d2c KH |
323 | /* |
324 | * used when a cpu is offlined or other synchronizations | |
325 | * See mem_cgroup_read_stat(). | |
326 | */ | |
327 | struct mem_cgroup_stat_cpu nocpu_base; | |
328 | spinlock_t pcp_counter_lock; | |
d1a4c0b3 | 329 | |
4bd2c1ee | 330 | #if defined(CONFIG_MEMCG_KMEM) && defined(CONFIG_INET) |
d1a4c0b3 GC |
331 | struct tcp_memcontrol tcp_mem; |
332 | #endif | |
8cdea7c0 BS |
333 | }; |
334 | ||
7dc74be0 DN |
335 | /* Stuffs for move charges at task migration. */ |
336 | /* | |
337 | * Types of charges to be moved. "move_charge_at_immitgrate" is treated as a | |
338 | * left-shifted bitmap of these types. | |
339 | */ | |
340 | enum move_type { | |
4ffef5fe | 341 | MOVE_CHARGE_TYPE_ANON, /* private anonymous page and swap of it */ |
87946a72 | 342 | MOVE_CHARGE_TYPE_FILE, /* file page(including tmpfs) and swap of it */ |
7dc74be0 DN |
343 | NR_MOVE_TYPE, |
344 | }; | |
345 | ||
4ffef5fe DN |
346 | /* "mc" and its members are protected by cgroup_mutex */ |
347 | static struct move_charge_struct { | |
b1dd693e | 348 | spinlock_t lock; /* for from, to */ |
4ffef5fe DN |
349 | struct mem_cgroup *from; |
350 | struct mem_cgroup *to; | |
351 | unsigned long precharge; | |
854ffa8d | 352 | unsigned long moved_charge; |
483c30b5 | 353 | unsigned long moved_swap; |
8033b97c DN |
354 | struct task_struct *moving_task; /* a task moving charges */ |
355 | wait_queue_head_t waitq; /* a waitq for other context */ | |
356 | } mc = { | |
2bd9bb20 | 357 | .lock = __SPIN_LOCK_UNLOCKED(mc.lock), |
8033b97c DN |
358 | .waitq = __WAIT_QUEUE_HEAD_INITIALIZER(mc.waitq), |
359 | }; | |
4ffef5fe | 360 | |
90254a65 DN |
361 | static bool move_anon(void) |
362 | { | |
363 | return test_bit(MOVE_CHARGE_TYPE_ANON, | |
364 | &mc.to->move_charge_at_immigrate); | |
365 | } | |
366 | ||
87946a72 DN |
367 | static bool move_file(void) |
368 | { | |
369 | return test_bit(MOVE_CHARGE_TYPE_FILE, | |
370 | &mc.to->move_charge_at_immigrate); | |
371 | } | |
372 | ||
4e416953 BS |
373 | /* |
374 | * Maximum loops in mem_cgroup_hierarchical_reclaim(), used for soft | |
375 | * limit reclaim to prevent infinite loops, if they ever occur. | |
376 | */ | |
a0db00fc KS |
377 | #define MEM_CGROUP_MAX_RECLAIM_LOOPS 100 |
378 | #define MEM_CGROUP_MAX_SOFT_LIMIT_RECLAIM_LOOPS 2 | |
4e416953 | 379 | |
217bc319 KH |
380 | enum charge_type { |
381 | MEM_CGROUP_CHARGE_TYPE_CACHE = 0, | |
41326c17 | 382 | MEM_CGROUP_CHARGE_TYPE_ANON, |
d13d1443 | 383 | MEM_CGROUP_CHARGE_TYPE_SWAPOUT, /* for accounting swapcache */ |
8a9478ca | 384 | MEM_CGROUP_CHARGE_TYPE_DROP, /* a page was unused swap cache */ |
c05555b5 KH |
385 | NR_CHARGE_TYPE, |
386 | }; | |
387 | ||
8c7c6e34 | 388 | /* for encoding cft->private value on file */ |
65c64ce8 GC |
389 | #define _MEM (0) |
390 | #define _MEMSWAP (1) | |
391 | #define _OOM_TYPE (2) | |
a0db00fc KS |
392 | #define MEMFILE_PRIVATE(x, val) ((x) << 16 | (val)) |
393 | #define MEMFILE_TYPE(val) ((val) >> 16 & 0xffff) | |
8c7c6e34 | 394 | #define MEMFILE_ATTR(val) ((val) & 0xffff) |
9490ff27 KH |
395 | /* Used for OOM nofiier */ |
396 | #define OOM_CONTROL (0) | |
8c7c6e34 | 397 | |
75822b44 BS |
398 | /* |
399 | * Reclaim flags for mem_cgroup_hierarchical_reclaim | |
400 | */ | |
401 | #define MEM_CGROUP_RECLAIM_NOSWAP_BIT 0x0 | |
402 | #define MEM_CGROUP_RECLAIM_NOSWAP (1 << MEM_CGROUP_RECLAIM_NOSWAP_BIT) | |
403 | #define MEM_CGROUP_RECLAIM_SHRINK_BIT 0x1 | |
404 | #define MEM_CGROUP_RECLAIM_SHRINK (1 << MEM_CGROUP_RECLAIM_SHRINK_BIT) | |
405 | ||
c0ff4b85 R |
406 | static void mem_cgroup_get(struct mem_cgroup *memcg); |
407 | static void mem_cgroup_put(struct mem_cgroup *memcg); | |
e1aab161 | 408 | |
b2145145 WL |
409 | static inline |
410 | struct mem_cgroup *mem_cgroup_from_css(struct cgroup_subsys_state *s) | |
411 | { | |
412 | return container_of(s, struct mem_cgroup, css); | |
413 | } | |
414 | ||
7ffc0edc MH |
415 | static inline bool mem_cgroup_is_root(struct mem_cgroup *memcg) |
416 | { | |
417 | return (memcg == root_mem_cgroup); | |
418 | } | |
419 | ||
e1aab161 | 420 | /* Writing them here to avoid exposing memcg's inner layout */ |
4bd2c1ee | 421 | #if defined(CONFIG_INET) && defined(CONFIG_MEMCG_KMEM) |
e1aab161 | 422 | |
e1aab161 GC |
423 | void sock_update_memcg(struct sock *sk) |
424 | { | |
376be5ff | 425 | if (mem_cgroup_sockets_enabled) { |
e1aab161 | 426 | struct mem_cgroup *memcg; |
3f134619 | 427 | struct cg_proto *cg_proto; |
e1aab161 GC |
428 | |
429 | BUG_ON(!sk->sk_prot->proto_cgroup); | |
430 | ||
f3f511e1 GC |
431 | /* Socket cloning can throw us here with sk_cgrp already |
432 | * filled. It won't however, necessarily happen from | |
433 | * process context. So the test for root memcg given | |
434 | * the current task's memcg won't help us in this case. | |
435 | * | |
436 | * Respecting the original socket's memcg is a better | |
437 | * decision in this case. | |
438 | */ | |
439 | if (sk->sk_cgrp) { | |
440 | BUG_ON(mem_cgroup_is_root(sk->sk_cgrp->memcg)); | |
441 | mem_cgroup_get(sk->sk_cgrp->memcg); | |
442 | return; | |
443 | } | |
444 | ||
e1aab161 GC |
445 | rcu_read_lock(); |
446 | memcg = mem_cgroup_from_task(current); | |
3f134619 GC |
447 | cg_proto = sk->sk_prot->proto_cgroup(memcg); |
448 | if (!mem_cgroup_is_root(memcg) && memcg_proto_active(cg_proto)) { | |
e1aab161 | 449 | mem_cgroup_get(memcg); |
3f134619 | 450 | sk->sk_cgrp = cg_proto; |
e1aab161 GC |
451 | } |
452 | rcu_read_unlock(); | |
453 | } | |
454 | } | |
455 | EXPORT_SYMBOL(sock_update_memcg); | |
456 | ||
457 | void sock_release_memcg(struct sock *sk) | |
458 | { | |
376be5ff | 459 | if (mem_cgroup_sockets_enabled && sk->sk_cgrp) { |
e1aab161 GC |
460 | struct mem_cgroup *memcg; |
461 | WARN_ON(!sk->sk_cgrp->memcg); | |
462 | memcg = sk->sk_cgrp->memcg; | |
463 | mem_cgroup_put(memcg); | |
464 | } | |
465 | } | |
d1a4c0b3 GC |
466 | |
467 | struct cg_proto *tcp_proto_cgroup(struct mem_cgroup *memcg) | |
468 | { | |
469 | if (!memcg || mem_cgroup_is_root(memcg)) | |
470 | return NULL; | |
471 | ||
472 | return &memcg->tcp_mem.cg_proto; | |
473 | } | |
474 | EXPORT_SYMBOL(tcp_proto_cgroup); | |
e1aab161 | 475 | |
3f134619 GC |
476 | static void disarm_sock_keys(struct mem_cgroup *memcg) |
477 | { | |
478 | if (!memcg_proto_activated(&memcg->tcp_mem.cg_proto)) | |
479 | return; | |
480 | static_key_slow_dec(&memcg_socket_limit_enabled); | |
481 | } | |
482 | #else | |
483 | static void disarm_sock_keys(struct mem_cgroup *memcg) | |
484 | { | |
485 | } | |
486 | #endif | |
487 | ||
c0ff4b85 | 488 | static void drain_all_stock_async(struct mem_cgroup *memcg); |
8c7c6e34 | 489 | |
f64c3f54 | 490 | static struct mem_cgroup_per_zone * |
c0ff4b85 | 491 | mem_cgroup_zoneinfo(struct mem_cgroup *memcg, int nid, int zid) |
f64c3f54 | 492 | { |
c0ff4b85 | 493 | return &memcg->info.nodeinfo[nid]->zoneinfo[zid]; |
f64c3f54 BS |
494 | } |
495 | ||
c0ff4b85 | 496 | struct cgroup_subsys_state *mem_cgroup_css(struct mem_cgroup *memcg) |
d324236b | 497 | { |
c0ff4b85 | 498 | return &memcg->css; |
d324236b WF |
499 | } |
500 | ||
f64c3f54 | 501 | static struct mem_cgroup_per_zone * |
c0ff4b85 | 502 | page_cgroup_zoneinfo(struct mem_cgroup *memcg, struct page *page) |
f64c3f54 | 503 | { |
97a6c37b JW |
504 | int nid = page_to_nid(page); |
505 | int zid = page_zonenum(page); | |
f64c3f54 | 506 | |
c0ff4b85 | 507 | return mem_cgroup_zoneinfo(memcg, nid, zid); |
f64c3f54 BS |
508 | } |
509 | ||
510 | static struct mem_cgroup_tree_per_zone * | |
511 | soft_limit_tree_node_zone(int nid, int zid) | |
512 | { | |
513 | return &soft_limit_tree.rb_tree_per_node[nid]->rb_tree_per_zone[zid]; | |
514 | } | |
515 | ||
516 | static struct mem_cgroup_tree_per_zone * | |
517 | soft_limit_tree_from_page(struct page *page) | |
518 | { | |
519 | int nid = page_to_nid(page); | |
520 | int zid = page_zonenum(page); | |
521 | ||
522 | return &soft_limit_tree.rb_tree_per_node[nid]->rb_tree_per_zone[zid]; | |
523 | } | |
524 | ||
525 | static void | |
c0ff4b85 | 526 | __mem_cgroup_insert_exceeded(struct mem_cgroup *memcg, |
f64c3f54 | 527 | struct mem_cgroup_per_zone *mz, |
ef8745c1 KH |
528 | struct mem_cgroup_tree_per_zone *mctz, |
529 | unsigned long long new_usage_in_excess) | |
f64c3f54 BS |
530 | { |
531 | struct rb_node **p = &mctz->rb_root.rb_node; | |
532 | struct rb_node *parent = NULL; | |
533 | struct mem_cgroup_per_zone *mz_node; | |
534 | ||
535 | if (mz->on_tree) | |
536 | return; | |
537 | ||
ef8745c1 KH |
538 | mz->usage_in_excess = new_usage_in_excess; |
539 | if (!mz->usage_in_excess) | |
540 | return; | |
f64c3f54 BS |
541 | while (*p) { |
542 | parent = *p; | |
543 | mz_node = rb_entry(parent, struct mem_cgroup_per_zone, | |
544 | tree_node); | |
545 | if (mz->usage_in_excess < mz_node->usage_in_excess) | |
546 | p = &(*p)->rb_left; | |
547 | /* | |
548 | * We can't avoid mem cgroups that are over their soft | |
549 | * limit by the same amount | |
550 | */ | |
551 | else if (mz->usage_in_excess >= mz_node->usage_in_excess) | |
552 | p = &(*p)->rb_right; | |
553 | } | |
554 | rb_link_node(&mz->tree_node, parent, p); | |
555 | rb_insert_color(&mz->tree_node, &mctz->rb_root); | |
556 | mz->on_tree = true; | |
4e416953 BS |
557 | } |
558 | ||
559 | static void | |
c0ff4b85 | 560 | __mem_cgroup_remove_exceeded(struct mem_cgroup *memcg, |
4e416953 BS |
561 | struct mem_cgroup_per_zone *mz, |
562 | struct mem_cgroup_tree_per_zone *mctz) | |
563 | { | |
564 | if (!mz->on_tree) | |
565 | return; | |
566 | rb_erase(&mz->tree_node, &mctz->rb_root); | |
567 | mz->on_tree = false; | |
568 | } | |
569 | ||
f64c3f54 | 570 | static void |
c0ff4b85 | 571 | mem_cgroup_remove_exceeded(struct mem_cgroup *memcg, |
f64c3f54 BS |
572 | struct mem_cgroup_per_zone *mz, |
573 | struct mem_cgroup_tree_per_zone *mctz) | |
574 | { | |
575 | spin_lock(&mctz->lock); | |
c0ff4b85 | 576 | __mem_cgroup_remove_exceeded(memcg, mz, mctz); |
f64c3f54 BS |
577 | spin_unlock(&mctz->lock); |
578 | } | |
579 | ||
f64c3f54 | 580 | |
c0ff4b85 | 581 | static void mem_cgroup_update_tree(struct mem_cgroup *memcg, struct page *page) |
f64c3f54 | 582 | { |
ef8745c1 | 583 | unsigned long long excess; |
f64c3f54 BS |
584 | struct mem_cgroup_per_zone *mz; |
585 | struct mem_cgroup_tree_per_zone *mctz; | |
4e649152 KH |
586 | int nid = page_to_nid(page); |
587 | int zid = page_zonenum(page); | |
f64c3f54 BS |
588 | mctz = soft_limit_tree_from_page(page); |
589 | ||
590 | /* | |
4e649152 KH |
591 | * Necessary to update all ancestors when hierarchy is used. |
592 | * because their event counter is not touched. | |
f64c3f54 | 593 | */ |
c0ff4b85 R |
594 | for (; memcg; memcg = parent_mem_cgroup(memcg)) { |
595 | mz = mem_cgroup_zoneinfo(memcg, nid, zid); | |
596 | excess = res_counter_soft_limit_excess(&memcg->res); | |
4e649152 KH |
597 | /* |
598 | * We have to update the tree if mz is on RB-tree or | |
599 | * mem is over its softlimit. | |
600 | */ | |
ef8745c1 | 601 | if (excess || mz->on_tree) { |
4e649152 KH |
602 | spin_lock(&mctz->lock); |
603 | /* if on-tree, remove it */ | |
604 | if (mz->on_tree) | |
c0ff4b85 | 605 | __mem_cgroup_remove_exceeded(memcg, mz, mctz); |
4e649152 | 606 | /* |
ef8745c1 KH |
607 | * Insert again. mz->usage_in_excess will be updated. |
608 | * If excess is 0, no tree ops. | |
4e649152 | 609 | */ |
c0ff4b85 | 610 | __mem_cgroup_insert_exceeded(memcg, mz, mctz, excess); |
4e649152 KH |
611 | spin_unlock(&mctz->lock); |
612 | } | |
f64c3f54 BS |
613 | } |
614 | } | |
615 | ||
c0ff4b85 | 616 | static void mem_cgroup_remove_from_trees(struct mem_cgroup *memcg) |
f64c3f54 BS |
617 | { |
618 | int node, zone; | |
619 | struct mem_cgroup_per_zone *mz; | |
620 | struct mem_cgroup_tree_per_zone *mctz; | |
621 | ||
3ed28fa1 | 622 | for_each_node(node) { |
f64c3f54 | 623 | for (zone = 0; zone < MAX_NR_ZONES; zone++) { |
c0ff4b85 | 624 | mz = mem_cgroup_zoneinfo(memcg, node, zone); |
f64c3f54 | 625 | mctz = soft_limit_tree_node_zone(node, zone); |
c0ff4b85 | 626 | mem_cgroup_remove_exceeded(memcg, mz, mctz); |
f64c3f54 BS |
627 | } |
628 | } | |
629 | } | |
630 | ||
4e416953 BS |
631 | static struct mem_cgroup_per_zone * |
632 | __mem_cgroup_largest_soft_limit_node(struct mem_cgroup_tree_per_zone *mctz) | |
633 | { | |
634 | struct rb_node *rightmost = NULL; | |
26251eaf | 635 | struct mem_cgroup_per_zone *mz; |
4e416953 BS |
636 | |
637 | retry: | |
26251eaf | 638 | mz = NULL; |
4e416953 BS |
639 | rightmost = rb_last(&mctz->rb_root); |
640 | if (!rightmost) | |
641 | goto done; /* Nothing to reclaim from */ | |
642 | ||
643 | mz = rb_entry(rightmost, struct mem_cgroup_per_zone, tree_node); | |
644 | /* | |
645 | * Remove the node now but someone else can add it back, | |
646 | * we will to add it back at the end of reclaim to its correct | |
647 | * position in the tree. | |
648 | */ | |
d79154bb HD |
649 | __mem_cgroup_remove_exceeded(mz->memcg, mz, mctz); |
650 | if (!res_counter_soft_limit_excess(&mz->memcg->res) || | |
651 | !css_tryget(&mz->memcg->css)) | |
4e416953 BS |
652 | goto retry; |
653 | done: | |
654 | return mz; | |
655 | } | |
656 | ||
657 | static struct mem_cgroup_per_zone * | |
658 | mem_cgroup_largest_soft_limit_node(struct mem_cgroup_tree_per_zone *mctz) | |
659 | { | |
660 | struct mem_cgroup_per_zone *mz; | |
661 | ||
662 | spin_lock(&mctz->lock); | |
663 | mz = __mem_cgroup_largest_soft_limit_node(mctz); | |
664 | spin_unlock(&mctz->lock); | |
665 | return mz; | |
666 | } | |
667 | ||
711d3d2c KH |
668 | /* |
669 | * Implementation Note: reading percpu statistics for memcg. | |
670 | * | |
671 | * Both of vmstat[] and percpu_counter has threshold and do periodic | |
672 | * synchronization to implement "quick" read. There are trade-off between | |
673 | * reading cost and precision of value. Then, we may have a chance to implement | |
674 | * a periodic synchronizion of counter in memcg's counter. | |
675 | * | |
676 | * But this _read() function is used for user interface now. The user accounts | |
677 | * memory usage by memory cgroup and he _always_ requires exact value because | |
678 | * he accounts memory. Even if we provide quick-and-fuzzy read, we always | |
679 | * have to visit all online cpus and make sum. So, for now, unnecessary | |
680 | * synchronization is not implemented. (just implemented for cpu hotplug) | |
681 | * | |
682 | * If there are kernel internal actions which can make use of some not-exact | |
683 | * value, and reading all cpu value can be performance bottleneck in some | |
684 | * common workload, threashold and synchonization as vmstat[] should be | |
685 | * implemented. | |
686 | */ | |
c0ff4b85 | 687 | static long mem_cgroup_read_stat(struct mem_cgroup *memcg, |
7a159cc9 | 688 | enum mem_cgroup_stat_index idx) |
c62b1a3b | 689 | { |
7a159cc9 | 690 | long val = 0; |
c62b1a3b | 691 | int cpu; |
c62b1a3b | 692 | |
711d3d2c KH |
693 | get_online_cpus(); |
694 | for_each_online_cpu(cpu) | |
c0ff4b85 | 695 | val += per_cpu(memcg->stat->count[idx], cpu); |
711d3d2c | 696 | #ifdef CONFIG_HOTPLUG_CPU |
c0ff4b85 R |
697 | spin_lock(&memcg->pcp_counter_lock); |
698 | val += memcg->nocpu_base.count[idx]; | |
699 | spin_unlock(&memcg->pcp_counter_lock); | |
711d3d2c KH |
700 | #endif |
701 | put_online_cpus(); | |
c62b1a3b KH |
702 | return val; |
703 | } | |
704 | ||
c0ff4b85 | 705 | static void mem_cgroup_swap_statistics(struct mem_cgroup *memcg, |
0c3e73e8 BS |
706 | bool charge) |
707 | { | |
708 | int val = (charge) ? 1 : -1; | |
bff6bb83 | 709 | this_cpu_add(memcg->stat->count[MEM_CGROUP_STAT_SWAP], val); |
0c3e73e8 BS |
710 | } |
711 | ||
c0ff4b85 | 712 | static unsigned long mem_cgroup_read_events(struct mem_cgroup *memcg, |
e9f8974f JW |
713 | enum mem_cgroup_events_index idx) |
714 | { | |
715 | unsigned long val = 0; | |
716 | int cpu; | |
717 | ||
718 | for_each_online_cpu(cpu) | |
c0ff4b85 | 719 | val += per_cpu(memcg->stat->events[idx], cpu); |
e9f8974f | 720 | #ifdef CONFIG_HOTPLUG_CPU |
c0ff4b85 R |
721 | spin_lock(&memcg->pcp_counter_lock); |
722 | val += memcg->nocpu_base.events[idx]; | |
723 | spin_unlock(&memcg->pcp_counter_lock); | |
e9f8974f JW |
724 | #endif |
725 | return val; | |
726 | } | |
727 | ||
c0ff4b85 | 728 | static void mem_cgroup_charge_statistics(struct mem_cgroup *memcg, |
b2402857 | 729 | bool anon, int nr_pages) |
d52aa412 | 730 | { |
c62b1a3b KH |
731 | preempt_disable(); |
732 | ||
b2402857 KH |
733 | /* |
734 | * Here, RSS means 'mapped anon' and anon's SwapCache. Shmem/tmpfs is | |
735 | * counted as CACHE even if it's on ANON LRU. | |
736 | */ | |
737 | if (anon) | |
738 | __this_cpu_add(memcg->stat->count[MEM_CGROUP_STAT_RSS], | |
c0ff4b85 | 739 | nr_pages); |
d52aa412 | 740 | else |
b2402857 | 741 | __this_cpu_add(memcg->stat->count[MEM_CGROUP_STAT_CACHE], |
c0ff4b85 | 742 | nr_pages); |
55e462b0 | 743 | |
e401f176 KH |
744 | /* pagein of a big page is an event. So, ignore page size */ |
745 | if (nr_pages > 0) | |
c0ff4b85 | 746 | __this_cpu_inc(memcg->stat->events[MEM_CGROUP_EVENTS_PGPGIN]); |
3751d604 | 747 | else { |
c0ff4b85 | 748 | __this_cpu_inc(memcg->stat->events[MEM_CGROUP_EVENTS_PGPGOUT]); |
3751d604 KH |
749 | nr_pages = -nr_pages; /* for event */ |
750 | } | |
e401f176 | 751 | |
13114716 | 752 | __this_cpu_add(memcg->stat->nr_page_events, nr_pages); |
2e72b634 | 753 | |
c62b1a3b | 754 | preempt_enable(); |
6d12e2d8 KH |
755 | } |
756 | ||
bb2a0de9 | 757 | unsigned long |
4d7dcca2 | 758 | mem_cgroup_get_lru_size(struct lruvec *lruvec, enum lru_list lru) |
074291fe KK |
759 | { |
760 | struct mem_cgroup_per_zone *mz; | |
761 | ||
762 | mz = container_of(lruvec, struct mem_cgroup_per_zone, lruvec); | |
763 | return mz->lru_size[lru]; | |
764 | } | |
765 | ||
766 | static unsigned long | |
c0ff4b85 | 767 | mem_cgroup_zone_nr_lru_pages(struct mem_cgroup *memcg, int nid, int zid, |
bb2a0de9 | 768 | unsigned int lru_mask) |
889976db YH |
769 | { |
770 | struct mem_cgroup_per_zone *mz; | |
f156ab93 | 771 | enum lru_list lru; |
bb2a0de9 KH |
772 | unsigned long ret = 0; |
773 | ||
c0ff4b85 | 774 | mz = mem_cgroup_zoneinfo(memcg, nid, zid); |
bb2a0de9 | 775 | |
f156ab93 HD |
776 | for_each_lru(lru) { |
777 | if (BIT(lru) & lru_mask) | |
778 | ret += mz->lru_size[lru]; | |
bb2a0de9 KH |
779 | } |
780 | return ret; | |
781 | } | |
782 | ||
783 | static unsigned long | |
c0ff4b85 | 784 | mem_cgroup_node_nr_lru_pages(struct mem_cgroup *memcg, |
bb2a0de9 KH |
785 | int nid, unsigned int lru_mask) |
786 | { | |
889976db YH |
787 | u64 total = 0; |
788 | int zid; | |
789 | ||
bb2a0de9 | 790 | for (zid = 0; zid < MAX_NR_ZONES; zid++) |
c0ff4b85 R |
791 | total += mem_cgroup_zone_nr_lru_pages(memcg, |
792 | nid, zid, lru_mask); | |
bb2a0de9 | 793 | |
889976db YH |
794 | return total; |
795 | } | |
bb2a0de9 | 796 | |
c0ff4b85 | 797 | static unsigned long mem_cgroup_nr_lru_pages(struct mem_cgroup *memcg, |
bb2a0de9 | 798 | unsigned int lru_mask) |
6d12e2d8 | 799 | { |
889976db | 800 | int nid; |
6d12e2d8 KH |
801 | u64 total = 0; |
802 | ||
bb2a0de9 | 803 | for_each_node_state(nid, N_HIGH_MEMORY) |
c0ff4b85 | 804 | total += mem_cgroup_node_nr_lru_pages(memcg, nid, lru_mask); |
6d12e2d8 | 805 | return total; |
d52aa412 KH |
806 | } |
807 | ||
f53d7ce3 JW |
808 | static bool mem_cgroup_event_ratelimit(struct mem_cgroup *memcg, |
809 | enum mem_cgroup_events_target target) | |
7a159cc9 JW |
810 | { |
811 | unsigned long val, next; | |
812 | ||
13114716 | 813 | val = __this_cpu_read(memcg->stat->nr_page_events); |
4799401f | 814 | next = __this_cpu_read(memcg->stat->targets[target]); |
7a159cc9 | 815 | /* from time_after() in jiffies.h */ |
f53d7ce3 JW |
816 | if ((long)next - (long)val < 0) { |
817 | switch (target) { | |
818 | case MEM_CGROUP_TARGET_THRESH: | |
819 | next = val + THRESHOLDS_EVENTS_TARGET; | |
820 | break; | |
821 | case MEM_CGROUP_TARGET_SOFTLIMIT: | |
822 | next = val + SOFTLIMIT_EVENTS_TARGET; | |
823 | break; | |
824 | case MEM_CGROUP_TARGET_NUMAINFO: | |
825 | next = val + NUMAINFO_EVENTS_TARGET; | |
826 | break; | |
827 | default: | |
828 | break; | |
829 | } | |
830 | __this_cpu_write(memcg->stat->targets[target], next); | |
831 | return true; | |
7a159cc9 | 832 | } |
f53d7ce3 | 833 | return false; |
d2265e6f KH |
834 | } |
835 | ||
836 | /* | |
837 | * Check events in order. | |
838 | * | |
839 | */ | |
c0ff4b85 | 840 | static void memcg_check_events(struct mem_cgroup *memcg, struct page *page) |
d2265e6f | 841 | { |
4799401f | 842 | preempt_disable(); |
d2265e6f | 843 | /* threshold event is triggered in finer grain than soft limit */ |
f53d7ce3 JW |
844 | if (unlikely(mem_cgroup_event_ratelimit(memcg, |
845 | MEM_CGROUP_TARGET_THRESH))) { | |
82b3f2a7 AM |
846 | bool do_softlimit; |
847 | bool do_numainfo __maybe_unused; | |
f53d7ce3 JW |
848 | |
849 | do_softlimit = mem_cgroup_event_ratelimit(memcg, | |
850 | MEM_CGROUP_TARGET_SOFTLIMIT); | |
851 | #if MAX_NUMNODES > 1 | |
852 | do_numainfo = mem_cgroup_event_ratelimit(memcg, | |
853 | MEM_CGROUP_TARGET_NUMAINFO); | |
854 | #endif | |
855 | preempt_enable(); | |
856 | ||
c0ff4b85 | 857 | mem_cgroup_threshold(memcg); |
f53d7ce3 | 858 | if (unlikely(do_softlimit)) |
c0ff4b85 | 859 | mem_cgroup_update_tree(memcg, page); |
453a9bf3 | 860 | #if MAX_NUMNODES > 1 |
f53d7ce3 | 861 | if (unlikely(do_numainfo)) |
c0ff4b85 | 862 | atomic_inc(&memcg->numainfo_events); |
453a9bf3 | 863 | #endif |
f53d7ce3 JW |
864 | } else |
865 | preempt_enable(); | |
d2265e6f KH |
866 | } |
867 | ||
d1a4c0b3 | 868 | struct mem_cgroup *mem_cgroup_from_cont(struct cgroup *cont) |
8cdea7c0 | 869 | { |
b2145145 WL |
870 | return mem_cgroup_from_css( |
871 | cgroup_subsys_state(cont, mem_cgroup_subsys_id)); | |
8cdea7c0 BS |
872 | } |
873 | ||
cf475ad2 | 874 | struct mem_cgroup *mem_cgroup_from_task(struct task_struct *p) |
78fb7466 | 875 | { |
31a78f23 BS |
876 | /* |
877 | * mm_update_next_owner() may clear mm->owner to NULL | |
878 | * if it races with swapoff, page migration, etc. | |
879 | * So this can be called with p == NULL. | |
880 | */ | |
881 | if (unlikely(!p)) | |
882 | return NULL; | |
883 | ||
b2145145 | 884 | return mem_cgroup_from_css(task_subsys_state(p, mem_cgroup_subsys_id)); |
78fb7466 PE |
885 | } |
886 | ||
a433658c | 887 | struct mem_cgroup *try_get_mem_cgroup_from_mm(struct mm_struct *mm) |
54595fe2 | 888 | { |
c0ff4b85 | 889 | struct mem_cgroup *memcg = NULL; |
0b7f569e KH |
890 | |
891 | if (!mm) | |
892 | return NULL; | |
54595fe2 KH |
893 | /* |
894 | * Because we have no locks, mm->owner's may be being moved to other | |
895 | * cgroup. We use css_tryget() here even if this looks | |
896 | * pessimistic (rather than adding locks here). | |
897 | */ | |
898 | rcu_read_lock(); | |
899 | do { | |
c0ff4b85 R |
900 | memcg = mem_cgroup_from_task(rcu_dereference(mm->owner)); |
901 | if (unlikely(!memcg)) | |
54595fe2 | 902 | break; |
c0ff4b85 | 903 | } while (!css_tryget(&memcg->css)); |
54595fe2 | 904 | rcu_read_unlock(); |
c0ff4b85 | 905 | return memcg; |
54595fe2 KH |
906 | } |
907 | ||
5660048c JW |
908 | /** |
909 | * mem_cgroup_iter - iterate over memory cgroup hierarchy | |
910 | * @root: hierarchy root | |
911 | * @prev: previously returned memcg, NULL on first invocation | |
912 | * @reclaim: cookie for shared reclaim walks, NULL for full walks | |
913 | * | |
914 | * Returns references to children of the hierarchy below @root, or | |
915 | * @root itself, or %NULL after a full round-trip. | |
916 | * | |
917 | * Caller must pass the return value in @prev on subsequent | |
918 | * invocations for reference counting, or use mem_cgroup_iter_break() | |
919 | * to cancel a hierarchy walk before the round-trip is complete. | |
920 | * | |
921 | * Reclaimers can specify a zone and a priority level in @reclaim to | |
922 | * divide up the memcgs in the hierarchy among all concurrent | |
923 | * reclaimers operating on the same zone and priority. | |
924 | */ | |
925 | struct mem_cgroup *mem_cgroup_iter(struct mem_cgroup *root, | |
926 | struct mem_cgroup *prev, | |
927 | struct mem_cgroup_reclaim_cookie *reclaim) | |
14067bb3 | 928 | { |
9f3a0d09 JW |
929 | struct mem_cgroup *memcg = NULL; |
930 | int id = 0; | |
711d3d2c | 931 | |
5660048c JW |
932 | if (mem_cgroup_disabled()) |
933 | return NULL; | |
934 | ||
9f3a0d09 JW |
935 | if (!root) |
936 | root = root_mem_cgroup; | |
7d74b06f | 937 | |
9f3a0d09 JW |
938 | if (prev && !reclaim) |
939 | id = css_id(&prev->css); | |
14067bb3 | 940 | |
9f3a0d09 JW |
941 | if (prev && prev != root) |
942 | css_put(&prev->css); | |
14067bb3 | 943 | |
9f3a0d09 JW |
944 | if (!root->use_hierarchy && root != root_mem_cgroup) { |
945 | if (prev) | |
946 | return NULL; | |
947 | return root; | |
948 | } | |
14067bb3 | 949 | |
9f3a0d09 | 950 | while (!memcg) { |
527a5ec9 | 951 | struct mem_cgroup_reclaim_iter *uninitialized_var(iter); |
9f3a0d09 | 952 | struct cgroup_subsys_state *css; |
711d3d2c | 953 | |
527a5ec9 JW |
954 | if (reclaim) { |
955 | int nid = zone_to_nid(reclaim->zone); | |
956 | int zid = zone_idx(reclaim->zone); | |
957 | struct mem_cgroup_per_zone *mz; | |
958 | ||
959 | mz = mem_cgroup_zoneinfo(root, nid, zid); | |
960 | iter = &mz->reclaim_iter[reclaim->priority]; | |
961 | if (prev && reclaim->generation != iter->generation) | |
962 | return NULL; | |
963 | id = iter->position; | |
964 | } | |
7d74b06f | 965 | |
9f3a0d09 JW |
966 | rcu_read_lock(); |
967 | css = css_get_next(&mem_cgroup_subsys, id + 1, &root->css, &id); | |
968 | if (css) { | |
969 | if (css == &root->css || css_tryget(css)) | |
b2145145 | 970 | memcg = mem_cgroup_from_css(css); |
9f3a0d09 JW |
971 | } else |
972 | id = 0; | |
14067bb3 | 973 | rcu_read_unlock(); |
14067bb3 | 974 | |
527a5ec9 JW |
975 | if (reclaim) { |
976 | iter->position = id; | |
977 | if (!css) | |
978 | iter->generation++; | |
979 | else if (!prev && memcg) | |
980 | reclaim->generation = iter->generation; | |
981 | } | |
9f3a0d09 JW |
982 | |
983 | if (prev && !css) | |
984 | return NULL; | |
985 | } | |
986 | return memcg; | |
14067bb3 | 987 | } |
7d74b06f | 988 | |
5660048c JW |
989 | /** |
990 | * mem_cgroup_iter_break - abort a hierarchy walk prematurely | |
991 | * @root: hierarchy root | |
992 | * @prev: last visited hierarchy member as returned by mem_cgroup_iter() | |
993 | */ | |
994 | void mem_cgroup_iter_break(struct mem_cgroup *root, | |
995 | struct mem_cgroup *prev) | |
9f3a0d09 JW |
996 | { |
997 | if (!root) | |
998 | root = root_mem_cgroup; | |
999 | if (prev && prev != root) | |
1000 | css_put(&prev->css); | |
1001 | } | |
7d74b06f | 1002 | |
9f3a0d09 JW |
1003 | /* |
1004 | * Iteration constructs for visiting all cgroups (under a tree). If | |
1005 | * loops are exited prematurely (break), mem_cgroup_iter_break() must | |
1006 | * be used for reference counting. | |
1007 | */ | |
1008 | #define for_each_mem_cgroup_tree(iter, root) \ | |
527a5ec9 | 1009 | for (iter = mem_cgroup_iter(root, NULL, NULL); \ |
9f3a0d09 | 1010 | iter != NULL; \ |
527a5ec9 | 1011 | iter = mem_cgroup_iter(root, iter, NULL)) |
711d3d2c | 1012 | |
9f3a0d09 | 1013 | #define for_each_mem_cgroup(iter) \ |
527a5ec9 | 1014 | for (iter = mem_cgroup_iter(NULL, NULL, NULL); \ |
9f3a0d09 | 1015 | iter != NULL; \ |
527a5ec9 | 1016 | iter = mem_cgroup_iter(NULL, iter, NULL)) |
14067bb3 | 1017 | |
456f998e YH |
1018 | void mem_cgroup_count_vm_event(struct mm_struct *mm, enum vm_event_item idx) |
1019 | { | |
c0ff4b85 | 1020 | struct mem_cgroup *memcg; |
456f998e YH |
1021 | |
1022 | if (!mm) | |
1023 | return; | |
1024 | ||
1025 | rcu_read_lock(); | |
c0ff4b85 R |
1026 | memcg = mem_cgroup_from_task(rcu_dereference(mm->owner)); |
1027 | if (unlikely(!memcg)) | |
456f998e YH |
1028 | goto out; |
1029 | ||
1030 | switch (idx) { | |
456f998e | 1031 | case PGFAULT: |
0e574a93 JW |
1032 | this_cpu_inc(memcg->stat->events[MEM_CGROUP_EVENTS_PGFAULT]); |
1033 | break; | |
1034 | case PGMAJFAULT: | |
1035 | this_cpu_inc(memcg->stat->events[MEM_CGROUP_EVENTS_PGMAJFAULT]); | |
456f998e YH |
1036 | break; |
1037 | default: | |
1038 | BUG(); | |
1039 | } | |
1040 | out: | |
1041 | rcu_read_unlock(); | |
1042 | } | |
1043 | EXPORT_SYMBOL(mem_cgroup_count_vm_event); | |
1044 | ||
925b7673 JW |
1045 | /** |
1046 | * mem_cgroup_zone_lruvec - get the lru list vector for a zone and memcg | |
1047 | * @zone: zone of the wanted lruvec | |
fa9add64 | 1048 | * @memcg: memcg of the wanted lruvec |
925b7673 JW |
1049 | * |
1050 | * Returns the lru list vector holding pages for the given @zone and | |
1051 | * @mem. This can be the global zone lruvec, if the memory controller | |
1052 | * is disabled. | |
1053 | */ | |
1054 | struct lruvec *mem_cgroup_zone_lruvec(struct zone *zone, | |
1055 | struct mem_cgroup *memcg) | |
1056 | { | |
1057 | struct mem_cgroup_per_zone *mz; | |
bea8c150 | 1058 | struct lruvec *lruvec; |
925b7673 | 1059 | |
bea8c150 HD |
1060 | if (mem_cgroup_disabled()) { |
1061 | lruvec = &zone->lruvec; | |
1062 | goto out; | |
1063 | } | |
925b7673 JW |
1064 | |
1065 | mz = mem_cgroup_zoneinfo(memcg, zone_to_nid(zone), zone_idx(zone)); | |
bea8c150 HD |
1066 | lruvec = &mz->lruvec; |
1067 | out: | |
1068 | /* | |
1069 | * Since a node can be onlined after the mem_cgroup was created, | |
1070 | * we have to be prepared to initialize lruvec->zone here; | |
1071 | * and if offlined then reonlined, we need to reinitialize it. | |
1072 | */ | |
1073 | if (unlikely(lruvec->zone != zone)) | |
1074 | lruvec->zone = zone; | |
1075 | return lruvec; | |
925b7673 JW |
1076 | } |
1077 | ||
08e552c6 KH |
1078 | /* |
1079 | * Following LRU functions are allowed to be used without PCG_LOCK. | |
1080 | * Operations are called by routine of global LRU independently from memcg. | |
1081 | * What we have to take care of here is validness of pc->mem_cgroup. | |
1082 | * | |
1083 | * Changes to pc->mem_cgroup happens when | |
1084 | * 1. charge | |
1085 | * 2. moving account | |
1086 | * In typical case, "charge" is done before add-to-lru. Exception is SwapCache. | |
1087 | * It is added to LRU before charge. | |
1088 | * If PCG_USED bit is not set, page_cgroup is not added to this private LRU. | |
1089 | * When moving account, the page is not on LRU. It's isolated. | |
1090 | */ | |
4f98a2fe | 1091 | |
925b7673 | 1092 | /** |
fa9add64 | 1093 | * mem_cgroup_page_lruvec - return lruvec for adding an lru page |
925b7673 | 1094 | * @page: the page |
fa9add64 | 1095 | * @zone: zone of the page |
925b7673 | 1096 | */ |
fa9add64 | 1097 | struct lruvec *mem_cgroup_page_lruvec(struct page *page, struct zone *zone) |
08e552c6 | 1098 | { |
08e552c6 | 1099 | struct mem_cgroup_per_zone *mz; |
925b7673 JW |
1100 | struct mem_cgroup *memcg; |
1101 | struct page_cgroup *pc; | |
bea8c150 | 1102 | struct lruvec *lruvec; |
6d12e2d8 | 1103 | |
bea8c150 HD |
1104 | if (mem_cgroup_disabled()) { |
1105 | lruvec = &zone->lruvec; | |
1106 | goto out; | |
1107 | } | |
925b7673 | 1108 | |
08e552c6 | 1109 | pc = lookup_page_cgroup(page); |
38c5d72f | 1110 | memcg = pc->mem_cgroup; |
7512102c HD |
1111 | |
1112 | /* | |
fa9add64 | 1113 | * Surreptitiously switch any uncharged offlist page to root: |
7512102c HD |
1114 | * an uncharged page off lru does nothing to secure |
1115 | * its former mem_cgroup from sudden removal. | |
1116 | * | |
1117 | * Our caller holds lru_lock, and PageCgroupUsed is updated | |
1118 | * under page_cgroup lock: between them, they make all uses | |
1119 | * of pc->mem_cgroup safe. | |
1120 | */ | |
fa9add64 | 1121 | if (!PageLRU(page) && !PageCgroupUsed(pc) && memcg != root_mem_cgroup) |
7512102c HD |
1122 | pc->mem_cgroup = memcg = root_mem_cgroup; |
1123 | ||
925b7673 | 1124 | mz = page_cgroup_zoneinfo(memcg, page); |
bea8c150 HD |
1125 | lruvec = &mz->lruvec; |
1126 | out: | |
1127 | /* | |
1128 | * Since a node can be onlined after the mem_cgroup was created, | |
1129 | * we have to be prepared to initialize lruvec->zone here; | |
1130 | * and if offlined then reonlined, we need to reinitialize it. | |
1131 | */ | |
1132 | if (unlikely(lruvec->zone != zone)) | |
1133 | lruvec->zone = zone; | |
1134 | return lruvec; | |
08e552c6 | 1135 | } |
b69408e8 | 1136 | |
925b7673 | 1137 | /** |
fa9add64 HD |
1138 | * mem_cgroup_update_lru_size - account for adding or removing an lru page |
1139 | * @lruvec: mem_cgroup per zone lru vector | |
1140 | * @lru: index of lru list the page is sitting on | |
1141 | * @nr_pages: positive when adding or negative when removing | |
925b7673 | 1142 | * |
fa9add64 HD |
1143 | * This function must be called when a page is added to or removed from an |
1144 | * lru list. | |
3f58a829 | 1145 | */ |
fa9add64 HD |
1146 | void mem_cgroup_update_lru_size(struct lruvec *lruvec, enum lru_list lru, |
1147 | int nr_pages) | |
3f58a829 MK |
1148 | { |
1149 | struct mem_cgroup_per_zone *mz; | |
fa9add64 | 1150 | unsigned long *lru_size; |
3f58a829 MK |
1151 | |
1152 | if (mem_cgroup_disabled()) | |
1153 | return; | |
1154 | ||
fa9add64 HD |
1155 | mz = container_of(lruvec, struct mem_cgroup_per_zone, lruvec); |
1156 | lru_size = mz->lru_size + lru; | |
1157 | *lru_size += nr_pages; | |
1158 | VM_BUG_ON((long)(*lru_size) < 0); | |
08e552c6 | 1159 | } |
544122e5 | 1160 | |
3e92041d | 1161 | /* |
c0ff4b85 | 1162 | * Checks whether given mem is same or in the root_mem_cgroup's |
3e92041d MH |
1163 | * hierarchy subtree |
1164 | */ | |
c3ac9a8a JW |
1165 | bool __mem_cgroup_same_or_subtree(const struct mem_cgroup *root_memcg, |
1166 | struct mem_cgroup *memcg) | |
3e92041d | 1167 | { |
91c63734 JW |
1168 | if (root_memcg == memcg) |
1169 | return true; | |
3a981f48 | 1170 | if (!root_memcg->use_hierarchy || !memcg) |
91c63734 | 1171 | return false; |
c3ac9a8a JW |
1172 | return css_is_ancestor(&memcg->css, &root_memcg->css); |
1173 | } | |
1174 | ||
1175 | static bool mem_cgroup_same_or_subtree(const struct mem_cgroup *root_memcg, | |
1176 | struct mem_cgroup *memcg) | |
1177 | { | |
1178 | bool ret; | |
1179 | ||
91c63734 | 1180 | rcu_read_lock(); |
c3ac9a8a | 1181 | ret = __mem_cgroup_same_or_subtree(root_memcg, memcg); |
91c63734 JW |
1182 | rcu_read_unlock(); |
1183 | return ret; | |
3e92041d MH |
1184 | } |
1185 | ||
c0ff4b85 | 1186 | int task_in_mem_cgroup(struct task_struct *task, const struct mem_cgroup *memcg) |
4c4a2214 DR |
1187 | { |
1188 | int ret; | |
0b7f569e | 1189 | struct mem_cgroup *curr = NULL; |
158e0a2d | 1190 | struct task_struct *p; |
4c4a2214 | 1191 | |
158e0a2d | 1192 | p = find_lock_task_mm(task); |
de077d22 DR |
1193 | if (p) { |
1194 | curr = try_get_mem_cgroup_from_mm(p->mm); | |
1195 | task_unlock(p); | |
1196 | } else { | |
1197 | /* | |
1198 | * All threads may have already detached their mm's, but the oom | |
1199 | * killer still needs to detect if they have already been oom | |
1200 | * killed to prevent needlessly killing additional tasks. | |
1201 | */ | |
1202 | task_lock(task); | |
1203 | curr = mem_cgroup_from_task(task); | |
1204 | if (curr) | |
1205 | css_get(&curr->css); | |
1206 | task_unlock(task); | |
1207 | } | |
0b7f569e KH |
1208 | if (!curr) |
1209 | return 0; | |
d31f56db | 1210 | /* |
c0ff4b85 | 1211 | * We should check use_hierarchy of "memcg" not "curr". Because checking |
d31f56db | 1212 | * use_hierarchy of "curr" here make this function true if hierarchy is |
c0ff4b85 R |
1213 | * enabled in "curr" and "curr" is a child of "memcg" in *cgroup* |
1214 | * hierarchy(even if use_hierarchy is disabled in "memcg"). | |
d31f56db | 1215 | */ |
c0ff4b85 | 1216 | ret = mem_cgroup_same_or_subtree(memcg, curr); |
0b7f569e | 1217 | css_put(&curr->css); |
4c4a2214 DR |
1218 | return ret; |
1219 | } | |
1220 | ||
c56d5c7d | 1221 | int mem_cgroup_inactive_anon_is_low(struct lruvec *lruvec) |
14797e23 | 1222 | { |
9b272977 | 1223 | unsigned long inactive_ratio; |
14797e23 | 1224 | unsigned long inactive; |
9b272977 | 1225 | unsigned long active; |
c772be93 | 1226 | unsigned long gb; |
14797e23 | 1227 | |
4d7dcca2 HD |
1228 | inactive = mem_cgroup_get_lru_size(lruvec, LRU_INACTIVE_ANON); |
1229 | active = mem_cgroup_get_lru_size(lruvec, LRU_ACTIVE_ANON); | |
14797e23 | 1230 | |
c772be93 KM |
1231 | gb = (inactive + active) >> (30 - PAGE_SHIFT); |
1232 | if (gb) | |
1233 | inactive_ratio = int_sqrt(10 * gb); | |
1234 | else | |
1235 | inactive_ratio = 1; | |
1236 | ||
9b272977 | 1237 | return inactive * inactive_ratio < active; |
14797e23 KM |
1238 | } |
1239 | ||
c56d5c7d | 1240 | int mem_cgroup_inactive_file_is_low(struct lruvec *lruvec) |
56e49d21 RR |
1241 | { |
1242 | unsigned long active; | |
1243 | unsigned long inactive; | |
1244 | ||
4d7dcca2 HD |
1245 | inactive = mem_cgroup_get_lru_size(lruvec, LRU_INACTIVE_FILE); |
1246 | active = mem_cgroup_get_lru_size(lruvec, LRU_ACTIVE_FILE); | |
56e49d21 RR |
1247 | |
1248 | return (active > inactive); | |
1249 | } | |
1250 | ||
6d61ef40 BS |
1251 | #define mem_cgroup_from_res_counter(counter, member) \ |
1252 | container_of(counter, struct mem_cgroup, member) | |
1253 | ||
19942822 | 1254 | /** |
9d11ea9f | 1255 | * mem_cgroup_margin - calculate chargeable space of a memory cgroup |
dad7557e | 1256 | * @memcg: the memory cgroup |
19942822 | 1257 | * |
9d11ea9f | 1258 | * Returns the maximum amount of memory @mem can be charged with, in |
7ec99d62 | 1259 | * pages. |
19942822 | 1260 | */ |
c0ff4b85 | 1261 | static unsigned long mem_cgroup_margin(struct mem_cgroup *memcg) |
19942822 | 1262 | { |
9d11ea9f JW |
1263 | unsigned long long margin; |
1264 | ||
c0ff4b85 | 1265 | margin = res_counter_margin(&memcg->res); |
9d11ea9f | 1266 | if (do_swap_account) |
c0ff4b85 | 1267 | margin = min(margin, res_counter_margin(&memcg->memsw)); |
7ec99d62 | 1268 | return margin >> PAGE_SHIFT; |
19942822 JW |
1269 | } |
1270 | ||
1f4c025b | 1271 | int mem_cgroup_swappiness(struct mem_cgroup *memcg) |
a7885eb8 KM |
1272 | { |
1273 | struct cgroup *cgrp = memcg->css.cgroup; | |
a7885eb8 KM |
1274 | |
1275 | /* root ? */ | |
1276 | if (cgrp->parent == NULL) | |
1277 | return vm_swappiness; | |
1278 | ||
bf1ff263 | 1279 | return memcg->swappiness; |
a7885eb8 KM |
1280 | } |
1281 | ||
619d094b KH |
1282 | /* |
1283 | * memcg->moving_account is used for checking possibility that some thread is | |
1284 | * calling move_account(). When a thread on CPU-A starts moving pages under | |
1285 | * a memcg, other threads should check memcg->moving_account under | |
1286 | * rcu_read_lock(), like this: | |
1287 | * | |
1288 | * CPU-A CPU-B | |
1289 | * rcu_read_lock() | |
1290 | * memcg->moving_account+1 if (memcg->mocing_account) | |
1291 | * take heavy locks. | |
1292 | * synchronize_rcu() update something. | |
1293 | * rcu_read_unlock() | |
1294 | * start move here. | |
1295 | */ | |
4331f7d3 KH |
1296 | |
1297 | /* for quick checking without looking up memcg */ | |
1298 | atomic_t memcg_moving __read_mostly; | |
1299 | ||
c0ff4b85 | 1300 | static void mem_cgroup_start_move(struct mem_cgroup *memcg) |
32047e2a | 1301 | { |
4331f7d3 | 1302 | atomic_inc(&memcg_moving); |
619d094b | 1303 | atomic_inc(&memcg->moving_account); |
32047e2a KH |
1304 | synchronize_rcu(); |
1305 | } | |
1306 | ||
c0ff4b85 | 1307 | static void mem_cgroup_end_move(struct mem_cgroup *memcg) |
32047e2a | 1308 | { |
619d094b KH |
1309 | /* |
1310 | * Now, mem_cgroup_clear_mc() may call this function with NULL. | |
1311 | * We check NULL in callee rather than caller. | |
1312 | */ | |
4331f7d3 KH |
1313 | if (memcg) { |
1314 | atomic_dec(&memcg_moving); | |
619d094b | 1315 | atomic_dec(&memcg->moving_account); |
4331f7d3 | 1316 | } |
32047e2a | 1317 | } |
619d094b | 1318 | |
32047e2a KH |
1319 | /* |
1320 | * 2 routines for checking "mem" is under move_account() or not. | |
1321 | * | |
13fd1dd9 AM |
1322 | * mem_cgroup_stolen() - checking whether a cgroup is mc.from or not. This |
1323 | * is used for avoiding races in accounting. If true, | |
32047e2a KH |
1324 | * pc->mem_cgroup may be overwritten. |
1325 | * | |
1326 | * mem_cgroup_under_move() - checking a cgroup is mc.from or mc.to or | |
1327 | * under hierarchy of moving cgroups. This is for | |
1328 | * waiting at hith-memory prressure caused by "move". | |
1329 | */ | |
1330 | ||
13fd1dd9 | 1331 | static bool mem_cgroup_stolen(struct mem_cgroup *memcg) |
32047e2a KH |
1332 | { |
1333 | VM_BUG_ON(!rcu_read_lock_held()); | |
619d094b | 1334 | return atomic_read(&memcg->moving_account) > 0; |
32047e2a | 1335 | } |
4b534334 | 1336 | |
c0ff4b85 | 1337 | static bool mem_cgroup_under_move(struct mem_cgroup *memcg) |
4b534334 | 1338 | { |
2bd9bb20 KH |
1339 | struct mem_cgroup *from; |
1340 | struct mem_cgroup *to; | |
4b534334 | 1341 | bool ret = false; |
2bd9bb20 KH |
1342 | /* |
1343 | * Unlike task_move routines, we access mc.to, mc.from not under | |
1344 | * mutual exclusion by cgroup_mutex. Here, we take spinlock instead. | |
1345 | */ | |
1346 | spin_lock(&mc.lock); | |
1347 | from = mc.from; | |
1348 | to = mc.to; | |
1349 | if (!from) | |
1350 | goto unlock; | |
3e92041d | 1351 | |
c0ff4b85 R |
1352 | ret = mem_cgroup_same_or_subtree(memcg, from) |
1353 | || mem_cgroup_same_or_subtree(memcg, to); | |
2bd9bb20 KH |
1354 | unlock: |
1355 | spin_unlock(&mc.lock); | |
4b534334 KH |
1356 | return ret; |
1357 | } | |
1358 | ||
c0ff4b85 | 1359 | static bool mem_cgroup_wait_acct_move(struct mem_cgroup *memcg) |
4b534334 KH |
1360 | { |
1361 | if (mc.moving_task && current != mc.moving_task) { | |
c0ff4b85 | 1362 | if (mem_cgroup_under_move(memcg)) { |
4b534334 KH |
1363 | DEFINE_WAIT(wait); |
1364 | prepare_to_wait(&mc.waitq, &wait, TASK_INTERRUPTIBLE); | |
1365 | /* moving charge context might have finished. */ | |
1366 | if (mc.moving_task) | |
1367 | schedule(); | |
1368 | finish_wait(&mc.waitq, &wait); | |
1369 | return true; | |
1370 | } | |
1371 | } | |
1372 | return false; | |
1373 | } | |
1374 | ||
312734c0 KH |
1375 | /* |
1376 | * Take this lock when | |
1377 | * - a code tries to modify page's memcg while it's USED. | |
1378 | * - a code tries to modify page state accounting in a memcg. | |
13fd1dd9 | 1379 | * see mem_cgroup_stolen(), too. |
312734c0 KH |
1380 | */ |
1381 | static void move_lock_mem_cgroup(struct mem_cgroup *memcg, | |
1382 | unsigned long *flags) | |
1383 | { | |
1384 | spin_lock_irqsave(&memcg->move_lock, *flags); | |
1385 | } | |
1386 | ||
1387 | static void move_unlock_mem_cgroup(struct mem_cgroup *memcg, | |
1388 | unsigned long *flags) | |
1389 | { | |
1390 | spin_unlock_irqrestore(&memcg->move_lock, *flags); | |
1391 | } | |
1392 | ||
e222432b | 1393 | /** |
6a6135b6 | 1394 | * mem_cgroup_print_oom_info: Called from OOM with tasklist_lock held in read mode. |
e222432b BS |
1395 | * @memcg: The memory cgroup that went over limit |
1396 | * @p: Task that is going to be killed | |
1397 | * | |
1398 | * NOTE: @memcg and @p's mem_cgroup can be different when hierarchy is | |
1399 | * enabled | |
1400 | */ | |
1401 | void mem_cgroup_print_oom_info(struct mem_cgroup *memcg, struct task_struct *p) | |
1402 | { | |
1403 | struct cgroup *task_cgrp; | |
1404 | struct cgroup *mem_cgrp; | |
1405 | /* | |
1406 | * Need a buffer in BSS, can't rely on allocations. The code relies | |
1407 | * on the assumption that OOM is serialized for memory controller. | |
1408 | * If this assumption is broken, revisit this code. | |
1409 | */ | |
1410 | static char memcg_name[PATH_MAX]; | |
1411 | int ret; | |
1412 | ||
d31f56db | 1413 | if (!memcg || !p) |
e222432b BS |
1414 | return; |
1415 | ||
e222432b BS |
1416 | rcu_read_lock(); |
1417 | ||
1418 | mem_cgrp = memcg->css.cgroup; | |
1419 | task_cgrp = task_cgroup(p, mem_cgroup_subsys_id); | |
1420 | ||
1421 | ret = cgroup_path(task_cgrp, memcg_name, PATH_MAX); | |
1422 | if (ret < 0) { | |
1423 | /* | |
1424 | * Unfortunately, we are unable to convert to a useful name | |
1425 | * But we'll still print out the usage information | |
1426 | */ | |
1427 | rcu_read_unlock(); | |
1428 | goto done; | |
1429 | } | |
1430 | rcu_read_unlock(); | |
1431 | ||
1432 | printk(KERN_INFO "Task in %s killed", memcg_name); | |
1433 | ||
1434 | rcu_read_lock(); | |
1435 | ret = cgroup_path(mem_cgrp, memcg_name, PATH_MAX); | |
1436 | if (ret < 0) { | |
1437 | rcu_read_unlock(); | |
1438 | goto done; | |
1439 | } | |
1440 | rcu_read_unlock(); | |
1441 | ||
1442 | /* | |
1443 | * Continues from above, so we don't need an KERN_ level | |
1444 | */ | |
1445 | printk(KERN_CONT " as a result of limit of %s\n", memcg_name); | |
1446 | done: | |
1447 | ||
1448 | printk(KERN_INFO "memory: usage %llukB, limit %llukB, failcnt %llu\n", | |
1449 | res_counter_read_u64(&memcg->res, RES_USAGE) >> 10, | |
1450 | res_counter_read_u64(&memcg->res, RES_LIMIT) >> 10, | |
1451 | res_counter_read_u64(&memcg->res, RES_FAILCNT)); | |
1452 | printk(KERN_INFO "memory+swap: usage %llukB, limit %llukB, " | |
1453 | "failcnt %llu\n", | |
1454 | res_counter_read_u64(&memcg->memsw, RES_USAGE) >> 10, | |
1455 | res_counter_read_u64(&memcg->memsw, RES_LIMIT) >> 10, | |
1456 | res_counter_read_u64(&memcg->memsw, RES_FAILCNT)); | |
1457 | } | |
1458 | ||
81d39c20 KH |
1459 | /* |
1460 | * This function returns the number of memcg under hierarchy tree. Returns | |
1461 | * 1(self count) if no children. | |
1462 | */ | |
c0ff4b85 | 1463 | static int mem_cgroup_count_children(struct mem_cgroup *memcg) |
81d39c20 KH |
1464 | { |
1465 | int num = 0; | |
7d74b06f KH |
1466 | struct mem_cgroup *iter; |
1467 | ||
c0ff4b85 | 1468 | for_each_mem_cgroup_tree(iter, memcg) |
7d74b06f | 1469 | num++; |
81d39c20 KH |
1470 | return num; |
1471 | } | |
1472 | ||
a63d83f4 DR |
1473 | /* |
1474 | * Return the memory (and swap, if configured) limit for a memcg. | |
1475 | */ | |
9cbb78bb | 1476 | static u64 mem_cgroup_get_limit(struct mem_cgroup *memcg) |
a63d83f4 DR |
1477 | { |
1478 | u64 limit; | |
a63d83f4 | 1479 | |
f3e8eb70 | 1480 | limit = res_counter_read_u64(&memcg->res, RES_LIMIT); |
f3e8eb70 | 1481 | |
a63d83f4 | 1482 | /* |
9a5a8f19 | 1483 | * Do not consider swap space if we cannot swap due to swappiness |
a63d83f4 | 1484 | */ |
9a5a8f19 MH |
1485 | if (mem_cgroup_swappiness(memcg)) { |
1486 | u64 memsw; | |
1487 | ||
1488 | limit += total_swap_pages << PAGE_SHIFT; | |
1489 | memsw = res_counter_read_u64(&memcg->memsw, RES_LIMIT); | |
1490 | ||
1491 | /* | |
1492 | * If memsw is finite and limits the amount of swap space | |
1493 | * available to this memcg, return that limit. | |
1494 | */ | |
1495 | limit = min(limit, memsw); | |
1496 | } | |
1497 | ||
1498 | return limit; | |
a63d83f4 DR |
1499 | } |
1500 | ||
19965460 DR |
1501 | static void mem_cgroup_out_of_memory(struct mem_cgroup *memcg, gfp_t gfp_mask, |
1502 | int order) | |
9cbb78bb DR |
1503 | { |
1504 | struct mem_cgroup *iter; | |
1505 | unsigned long chosen_points = 0; | |
1506 | unsigned long totalpages; | |
1507 | unsigned int points = 0; | |
1508 | struct task_struct *chosen = NULL; | |
1509 | ||
876aafbf DR |
1510 | /* |
1511 | * If current has a pending SIGKILL, then automatically select it. The | |
1512 | * goal is to allow it to allocate so that it may quickly exit and free | |
1513 | * its memory. | |
1514 | */ | |
1515 | if (fatal_signal_pending(current)) { | |
1516 | set_thread_flag(TIF_MEMDIE); | |
1517 | return; | |
1518 | } | |
1519 | ||
1520 | check_panic_on_oom(CONSTRAINT_MEMCG, gfp_mask, order, NULL); | |
9cbb78bb DR |
1521 | totalpages = mem_cgroup_get_limit(memcg) >> PAGE_SHIFT ? : 1; |
1522 | for_each_mem_cgroup_tree(iter, memcg) { | |
1523 | struct cgroup *cgroup = iter->css.cgroup; | |
1524 | struct cgroup_iter it; | |
1525 | struct task_struct *task; | |
1526 | ||
1527 | cgroup_iter_start(cgroup, &it); | |
1528 | while ((task = cgroup_iter_next(cgroup, &it))) { | |
1529 | switch (oom_scan_process_thread(task, totalpages, NULL, | |
1530 | false)) { | |
1531 | case OOM_SCAN_SELECT: | |
1532 | if (chosen) | |
1533 | put_task_struct(chosen); | |
1534 | chosen = task; | |
1535 | chosen_points = ULONG_MAX; | |
1536 | get_task_struct(chosen); | |
1537 | /* fall through */ | |
1538 | case OOM_SCAN_CONTINUE: | |
1539 | continue; | |
1540 | case OOM_SCAN_ABORT: | |
1541 | cgroup_iter_end(cgroup, &it); | |
1542 | mem_cgroup_iter_break(memcg, iter); | |
1543 | if (chosen) | |
1544 | put_task_struct(chosen); | |
1545 | return; | |
1546 | case OOM_SCAN_OK: | |
1547 | break; | |
1548 | }; | |
1549 | points = oom_badness(task, memcg, NULL, totalpages); | |
1550 | if (points > chosen_points) { | |
1551 | if (chosen) | |
1552 | put_task_struct(chosen); | |
1553 | chosen = task; | |
1554 | chosen_points = points; | |
1555 | get_task_struct(chosen); | |
1556 | } | |
1557 | } | |
1558 | cgroup_iter_end(cgroup, &it); | |
1559 | } | |
1560 | ||
1561 | if (!chosen) | |
1562 | return; | |
1563 | points = chosen_points * 1000 / totalpages; | |
9cbb78bb DR |
1564 | oom_kill_process(chosen, gfp_mask, order, points, totalpages, memcg, |
1565 | NULL, "Memory cgroup out of memory"); | |
9cbb78bb DR |
1566 | } |
1567 | ||
5660048c JW |
1568 | static unsigned long mem_cgroup_reclaim(struct mem_cgroup *memcg, |
1569 | gfp_t gfp_mask, | |
1570 | unsigned long flags) | |
1571 | { | |
1572 | unsigned long total = 0; | |
1573 | bool noswap = false; | |
1574 | int loop; | |
1575 | ||
1576 | if (flags & MEM_CGROUP_RECLAIM_NOSWAP) | |
1577 | noswap = true; | |
1578 | if (!(flags & MEM_CGROUP_RECLAIM_SHRINK) && memcg->memsw_is_minimum) | |
1579 | noswap = true; | |
1580 | ||
1581 | for (loop = 0; loop < MEM_CGROUP_MAX_RECLAIM_LOOPS; loop++) { | |
1582 | if (loop) | |
1583 | drain_all_stock_async(memcg); | |
1584 | total += try_to_free_mem_cgroup_pages(memcg, gfp_mask, noswap); | |
1585 | /* | |
1586 | * Allow limit shrinkers, which are triggered directly | |
1587 | * by userspace, to catch signals and stop reclaim | |
1588 | * after minimal progress, regardless of the margin. | |
1589 | */ | |
1590 | if (total && (flags & MEM_CGROUP_RECLAIM_SHRINK)) | |
1591 | break; | |
1592 | if (mem_cgroup_margin(memcg)) | |
1593 | break; | |
1594 | /* | |
1595 | * If nothing was reclaimed after two attempts, there | |
1596 | * may be no reclaimable pages in this hierarchy. | |
1597 | */ | |
1598 | if (loop && !total) | |
1599 | break; | |
1600 | } | |
1601 | return total; | |
1602 | } | |
1603 | ||
4d0c066d KH |
1604 | /** |
1605 | * test_mem_cgroup_node_reclaimable | |
dad7557e | 1606 | * @memcg: the target memcg |
4d0c066d KH |
1607 | * @nid: the node ID to be checked. |
1608 | * @noswap : specify true here if the user wants flle only information. | |
1609 | * | |
1610 | * This function returns whether the specified memcg contains any | |
1611 | * reclaimable pages on a node. Returns true if there are any reclaimable | |
1612 | * pages in the node. | |
1613 | */ | |
c0ff4b85 | 1614 | static bool test_mem_cgroup_node_reclaimable(struct mem_cgroup *memcg, |
4d0c066d KH |
1615 | int nid, bool noswap) |
1616 | { | |
c0ff4b85 | 1617 | if (mem_cgroup_node_nr_lru_pages(memcg, nid, LRU_ALL_FILE)) |
4d0c066d KH |
1618 | return true; |
1619 | if (noswap || !total_swap_pages) | |
1620 | return false; | |
c0ff4b85 | 1621 | if (mem_cgroup_node_nr_lru_pages(memcg, nid, LRU_ALL_ANON)) |
4d0c066d KH |
1622 | return true; |
1623 | return false; | |
1624 | ||
1625 | } | |
889976db YH |
1626 | #if MAX_NUMNODES > 1 |
1627 | ||
1628 | /* | |
1629 | * Always updating the nodemask is not very good - even if we have an empty | |
1630 | * list or the wrong list here, we can start from some node and traverse all | |
1631 | * nodes based on the zonelist. So update the list loosely once per 10 secs. | |
1632 | * | |
1633 | */ | |
c0ff4b85 | 1634 | static void mem_cgroup_may_update_nodemask(struct mem_cgroup *memcg) |
889976db YH |
1635 | { |
1636 | int nid; | |
453a9bf3 KH |
1637 | /* |
1638 | * numainfo_events > 0 means there was at least NUMAINFO_EVENTS_TARGET | |
1639 | * pagein/pageout changes since the last update. | |
1640 | */ | |
c0ff4b85 | 1641 | if (!atomic_read(&memcg->numainfo_events)) |
453a9bf3 | 1642 | return; |
c0ff4b85 | 1643 | if (atomic_inc_return(&memcg->numainfo_updating) > 1) |
889976db YH |
1644 | return; |
1645 | ||
889976db | 1646 | /* make a nodemask where this memcg uses memory from */ |
c0ff4b85 | 1647 | memcg->scan_nodes = node_states[N_HIGH_MEMORY]; |
889976db YH |
1648 | |
1649 | for_each_node_mask(nid, node_states[N_HIGH_MEMORY]) { | |
1650 | ||
c0ff4b85 R |
1651 | if (!test_mem_cgroup_node_reclaimable(memcg, nid, false)) |
1652 | node_clear(nid, memcg->scan_nodes); | |
889976db | 1653 | } |
453a9bf3 | 1654 | |
c0ff4b85 R |
1655 | atomic_set(&memcg->numainfo_events, 0); |
1656 | atomic_set(&memcg->numainfo_updating, 0); | |
889976db YH |
1657 | } |
1658 | ||
1659 | /* | |
1660 | * Selecting a node where we start reclaim from. Because what we need is just | |
1661 | * reducing usage counter, start from anywhere is O,K. Considering | |
1662 | * memory reclaim from current node, there are pros. and cons. | |
1663 | * | |
1664 | * Freeing memory from current node means freeing memory from a node which | |
1665 | * we'll use or we've used. So, it may make LRU bad. And if several threads | |
1666 | * hit limits, it will see a contention on a node. But freeing from remote | |
1667 | * node means more costs for memory reclaim because of memory latency. | |
1668 | * | |
1669 | * Now, we use round-robin. Better algorithm is welcomed. | |
1670 | */ | |
c0ff4b85 | 1671 | int mem_cgroup_select_victim_node(struct mem_cgroup *memcg) |
889976db YH |
1672 | { |
1673 | int node; | |
1674 | ||
c0ff4b85 R |
1675 | mem_cgroup_may_update_nodemask(memcg); |
1676 | node = memcg->last_scanned_node; | |
889976db | 1677 | |
c0ff4b85 | 1678 | node = next_node(node, memcg->scan_nodes); |
889976db | 1679 | if (node == MAX_NUMNODES) |
c0ff4b85 | 1680 | node = first_node(memcg->scan_nodes); |
889976db YH |
1681 | /* |
1682 | * We call this when we hit limit, not when pages are added to LRU. | |
1683 | * No LRU may hold pages because all pages are UNEVICTABLE or | |
1684 | * memcg is too small and all pages are not on LRU. In that case, | |
1685 | * we use curret node. | |
1686 | */ | |
1687 | if (unlikely(node == MAX_NUMNODES)) | |
1688 | node = numa_node_id(); | |
1689 | ||
c0ff4b85 | 1690 | memcg->last_scanned_node = node; |
889976db YH |
1691 | return node; |
1692 | } | |
1693 | ||
4d0c066d KH |
1694 | /* |
1695 | * Check all nodes whether it contains reclaimable pages or not. | |
1696 | * For quick scan, we make use of scan_nodes. This will allow us to skip | |
1697 | * unused nodes. But scan_nodes is lazily updated and may not cotain | |
1698 | * enough new information. We need to do double check. | |
1699 | */ | |
6bbda35c | 1700 | static bool mem_cgroup_reclaimable(struct mem_cgroup *memcg, bool noswap) |
4d0c066d KH |
1701 | { |
1702 | int nid; | |
1703 | ||
1704 | /* | |
1705 | * quick check...making use of scan_node. | |
1706 | * We can skip unused nodes. | |
1707 | */ | |
c0ff4b85 R |
1708 | if (!nodes_empty(memcg->scan_nodes)) { |
1709 | for (nid = first_node(memcg->scan_nodes); | |
4d0c066d | 1710 | nid < MAX_NUMNODES; |
c0ff4b85 | 1711 | nid = next_node(nid, memcg->scan_nodes)) { |
4d0c066d | 1712 | |
c0ff4b85 | 1713 | if (test_mem_cgroup_node_reclaimable(memcg, nid, noswap)) |
4d0c066d KH |
1714 | return true; |
1715 | } | |
1716 | } | |
1717 | /* | |
1718 | * Check rest of nodes. | |
1719 | */ | |
1720 | for_each_node_state(nid, N_HIGH_MEMORY) { | |
c0ff4b85 | 1721 | if (node_isset(nid, memcg->scan_nodes)) |
4d0c066d | 1722 | continue; |
c0ff4b85 | 1723 | if (test_mem_cgroup_node_reclaimable(memcg, nid, noswap)) |
4d0c066d KH |
1724 | return true; |
1725 | } | |
1726 | return false; | |
1727 | } | |
1728 | ||
889976db | 1729 | #else |
c0ff4b85 | 1730 | int mem_cgroup_select_victim_node(struct mem_cgroup *memcg) |
889976db YH |
1731 | { |
1732 | return 0; | |
1733 | } | |
4d0c066d | 1734 | |
6bbda35c | 1735 | static bool mem_cgroup_reclaimable(struct mem_cgroup *memcg, bool noswap) |
4d0c066d | 1736 | { |
c0ff4b85 | 1737 | return test_mem_cgroup_node_reclaimable(memcg, 0, noswap); |
4d0c066d | 1738 | } |
889976db YH |
1739 | #endif |
1740 | ||
5660048c JW |
1741 | static int mem_cgroup_soft_reclaim(struct mem_cgroup *root_memcg, |
1742 | struct zone *zone, | |
1743 | gfp_t gfp_mask, | |
1744 | unsigned long *total_scanned) | |
6d61ef40 | 1745 | { |
9f3a0d09 | 1746 | struct mem_cgroup *victim = NULL; |
5660048c | 1747 | int total = 0; |
04046e1a | 1748 | int loop = 0; |
9d11ea9f | 1749 | unsigned long excess; |
185efc0f | 1750 | unsigned long nr_scanned; |
527a5ec9 JW |
1751 | struct mem_cgroup_reclaim_cookie reclaim = { |
1752 | .zone = zone, | |
1753 | .priority = 0, | |
1754 | }; | |
9d11ea9f | 1755 | |
c0ff4b85 | 1756 | excess = res_counter_soft_limit_excess(&root_memcg->res) >> PAGE_SHIFT; |
04046e1a | 1757 | |
4e416953 | 1758 | while (1) { |
527a5ec9 | 1759 | victim = mem_cgroup_iter(root_memcg, victim, &reclaim); |
9f3a0d09 | 1760 | if (!victim) { |
04046e1a | 1761 | loop++; |
4e416953 BS |
1762 | if (loop >= 2) { |
1763 | /* | |
1764 | * If we have not been able to reclaim | |
1765 | * anything, it might because there are | |
1766 | * no reclaimable pages under this hierarchy | |
1767 | */ | |
5660048c | 1768 | if (!total) |
4e416953 | 1769 | break; |
4e416953 | 1770 | /* |
25985edc | 1771 | * We want to do more targeted reclaim. |
4e416953 BS |
1772 | * excess >> 2 is not to excessive so as to |
1773 | * reclaim too much, nor too less that we keep | |
1774 | * coming back to reclaim from this cgroup | |
1775 | */ | |
1776 | if (total >= (excess >> 2) || | |
9f3a0d09 | 1777 | (loop > MEM_CGROUP_MAX_RECLAIM_LOOPS)) |
4e416953 | 1778 | break; |
4e416953 | 1779 | } |
9f3a0d09 | 1780 | continue; |
4e416953 | 1781 | } |
5660048c | 1782 | if (!mem_cgroup_reclaimable(victim, false)) |
6d61ef40 | 1783 | continue; |
5660048c JW |
1784 | total += mem_cgroup_shrink_node_zone(victim, gfp_mask, false, |
1785 | zone, &nr_scanned); | |
1786 | *total_scanned += nr_scanned; | |
1787 | if (!res_counter_soft_limit_excess(&root_memcg->res)) | |
9f3a0d09 | 1788 | break; |
6d61ef40 | 1789 | } |
9f3a0d09 | 1790 | mem_cgroup_iter_break(root_memcg, victim); |
04046e1a | 1791 | return total; |
6d61ef40 BS |
1792 | } |
1793 | ||
867578cb KH |
1794 | /* |
1795 | * Check OOM-Killer is already running under our hierarchy. | |
1796 | * If someone is running, return false. | |
1af8efe9 | 1797 | * Has to be called with memcg_oom_lock |
867578cb | 1798 | */ |
c0ff4b85 | 1799 | static bool mem_cgroup_oom_lock(struct mem_cgroup *memcg) |
867578cb | 1800 | { |
79dfdacc | 1801 | struct mem_cgroup *iter, *failed = NULL; |
a636b327 | 1802 | |
9f3a0d09 | 1803 | for_each_mem_cgroup_tree(iter, memcg) { |
23751be0 | 1804 | if (iter->oom_lock) { |
79dfdacc MH |
1805 | /* |
1806 | * this subtree of our hierarchy is already locked | |
1807 | * so we cannot give a lock. | |
1808 | */ | |
79dfdacc | 1809 | failed = iter; |
9f3a0d09 JW |
1810 | mem_cgroup_iter_break(memcg, iter); |
1811 | break; | |
23751be0 JW |
1812 | } else |
1813 | iter->oom_lock = true; | |
7d74b06f | 1814 | } |
867578cb | 1815 | |
79dfdacc | 1816 | if (!failed) |
23751be0 | 1817 | return true; |
79dfdacc MH |
1818 | |
1819 | /* | |
1820 | * OK, we failed to lock the whole subtree so we have to clean up | |
1821 | * what we set up to the failing subtree | |
1822 | */ | |
9f3a0d09 | 1823 | for_each_mem_cgroup_tree(iter, memcg) { |
79dfdacc | 1824 | if (iter == failed) { |
9f3a0d09 JW |
1825 | mem_cgroup_iter_break(memcg, iter); |
1826 | break; | |
79dfdacc MH |
1827 | } |
1828 | iter->oom_lock = false; | |
1829 | } | |
23751be0 | 1830 | return false; |
a636b327 | 1831 | } |
0b7f569e | 1832 | |
79dfdacc | 1833 | /* |
1af8efe9 | 1834 | * Has to be called with memcg_oom_lock |
79dfdacc | 1835 | */ |
c0ff4b85 | 1836 | static int mem_cgroup_oom_unlock(struct mem_cgroup *memcg) |
0b7f569e | 1837 | { |
7d74b06f KH |
1838 | struct mem_cgroup *iter; |
1839 | ||
c0ff4b85 | 1840 | for_each_mem_cgroup_tree(iter, memcg) |
79dfdacc MH |
1841 | iter->oom_lock = false; |
1842 | return 0; | |
1843 | } | |
1844 | ||
c0ff4b85 | 1845 | static void mem_cgroup_mark_under_oom(struct mem_cgroup *memcg) |
79dfdacc MH |
1846 | { |
1847 | struct mem_cgroup *iter; | |
1848 | ||
c0ff4b85 | 1849 | for_each_mem_cgroup_tree(iter, memcg) |
79dfdacc MH |
1850 | atomic_inc(&iter->under_oom); |
1851 | } | |
1852 | ||
c0ff4b85 | 1853 | static void mem_cgroup_unmark_under_oom(struct mem_cgroup *memcg) |
79dfdacc MH |
1854 | { |
1855 | struct mem_cgroup *iter; | |
1856 | ||
867578cb KH |
1857 | /* |
1858 | * When a new child is created while the hierarchy is under oom, | |
1859 | * mem_cgroup_oom_lock() may not be called. We have to use | |
1860 | * atomic_add_unless() here. | |
1861 | */ | |
c0ff4b85 | 1862 | for_each_mem_cgroup_tree(iter, memcg) |
79dfdacc | 1863 | atomic_add_unless(&iter->under_oom, -1, 0); |
0b7f569e KH |
1864 | } |
1865 | ||
1af8efe9 | 1866 | static DEFINE_SPINLOCK(memcg_oom_lock); |
867578cb KH |
1867 | static DECLARE_WAIT_QUEUE_HEAD(memcg_oom_waitq); |
1868 | ||
dc98df5a | 1869 | struct oom_wait_info { |
d79154bb | 1870 | struct mem_cgroup *memcg; |
dc98df5a KH |
1871 | wait_queue_t wait; |
1872 | }; | |
1873 | ||
1874 | static int memcg_oom_wake_function(wait_queue_t *wait, | |
1875 | unsigned mode, int sync, void *arg) | |
1876 | { | |
d79154bb HD |
1877 | struct mem_cgroup *wake_memcg = (struct mem_cgroup *)arg; |
1878 | struct mem_cgroup *oom_wait_memcg; | |
dc98df5a KH |
1879 | struct oom_wait_info *oom_wait_info; |
1880 | ||
1881 | oom_wait_info = container_of(wait, struct oom_wait_info, wait); | |
d79154bb | 1882 | oom_wait_memcg = oom_wait_info->memcg; |
dc98df5a | 1883 | |
dc98df5a | 1884 | /* |
d79154bb | 1885 | * Both of oom_wait_info->memcg and wake_memcg are stable under us. |
dc98df5a KH |
1886 | * Then we can use css_is_ancestor without taking care of RCU. |
1887 | */ | |
c0ff4b85 R |
1888 | if (!mem_cgroup_same_or_subtree(oom_wait_memcg, wake_memcg) |
1889 | && !mem_cgroup_same_or_subtree(wake_memcg, oom_wait_memcg)) | |
dc98df5a | 1890 | return 0; |
dc98df5a KH |
1891 | return autoremove_wake_function(wait, mode, sync, arg); |
1892 | } | |
1893 | ||
c0ff4b85 | 1894 | static void memcg_wakeup_oom(struct mem_cgroup *memcg) |
dc98df5a | 1895 | { |
c0ff4b85 R |
1896 | /* for filtering, pass "memcg" as argument. */ |
1897 | __wake_up(&memcg_oom_waitq, TASK_NORMAL, 0, memcg); | |
dc98df5a KH |
1898 | } |
1899 | ||
c0ff4b85 | 1900 | static void memcg_oom_recover(struct mem_cgroup *memcg) |
3c11ecf4 | 1901 | { |
c0ff4b85 R |
1902 | if (memcg && atomic_read(&memcg->under_oom)) |
1903 | memcg_wakeup_oom(memcg); | |
3c11ecf4 KH |
1904 | } |
1905 | ||
867578cb KH |
1906 | /* |
1907 | * try to call OOM killer. returns false if we should exit memory-reclaim loop. | |
1908 | */ | |
6bbda35c KS |
1909 | static bool mem_cgroup_handle_oom(struct mem_cgroup *memcg, gfp_t mask, |
1910 | int order) | |
0b7f569e | 1911 | { |
dc98df5a | 1912 | struct oom_wait_info owait; |
3c11ecf4 | 1913 | bool locked, need_to_kill; |
867578cb | 1914 | |
d79154bb | 1915 | owait.memcg = memcg; |
dc98df5a KH |
1916 | owait.wait.flags = 0; |
1917 | owait.wait.func = memcg_oom_wake_function; | |
1918 | owait.wait.private = current; | |
1919 | INIT_LIST_HEAD(&owait.wait.task_list); | |
3c11ecf4 | 1920 | need_to_kill = true; |
c0ff4b85 | 1921 | mem_cgroup_mark_under_oom(memcg); |
79dfdacc | 1922 | |
c0ff4b85 | 1923 | /* At first, try to OOM lock hierarchy under memcg.*/ |
1af8efe9 | 1924 | spin_lock(&memcg_oom_lock); |
c0ff4b85 | 1925 | locked = mem_cgroup_oom_lock(memcg); |
867578cb KH |
1926 | /* |
1927 | * Even if signal_pending(), we can't quit charge() loop without | |
1928 | * accounting. So, UNINTERRUPTIBLE is appropriate. But SIGKILL | |
1929 | * under OOM is always welcomed, use TASK_KILLABLE here. | |
1930 | */ | |
3c11ecf4 | 1931 | prepare_to_wait(&memcg_oom_waitq, &owait.wait, TASK_KILLABLE); |
c0ff4b85 | 1932 | if (!locked || memcg->oom_kill_disable) |
3c11ecf4 KH |
1933 | need_to_kill = false; |
1934 | if (locked) | |
c0ff4b85 | 1935 | mem_cgroup_oom_notify(memcg); |
1af8efe9 | 1936 | spin_unlock(&memcg_oom_lock); |
867578cb | 1937 | |
3c11ecf4 KH |
1938 | if (need_to_kill) { |
1939 | finish_wait(&memcg_oom_waitq, &owait.wait); | |
e845e199 | 1940 | mem_cgroup_out_of_memory(memcg, mask, order); |
3c11ecf4 | 1941 | } else { |
867578cb | 1942 | schedule(); |
dc98df5a | 1943 | finish_wait(&memcg_oom_waitq, &owait.wait); |
867578cb | 1944 | } |
1af8efe9 | 1945 | spin_lock(&memcg_oom_lock); |
79dfdacc | 1946 | if (locked) |
c0ff4b85 R |
1947 | mem_cgroup_oom_unlock(memcg); |
1948 | memcg_wakeup_oom(memcg); | |
1af8efe9 | 1949 | spin_unlock(&memcg_oom_lock); |
867578cb | 1950 | |
c0ff4b85 | 1951 | mem_cgroup_unmark_under_oom(memcg); |
79dfdacc | 1952 | |
867578cb KH |
1953 | if (test_thread_flag(TIF_MEMDIE) || fatal_signal_pending(current)) |
1954 | return false; | |
1955 | /* Give chance to dying process */ | |
715a5ee8 | 1956 | schedule_timeout_uninterruptible(1); |
867578cb | 1957 | return true; |
0b7f569e KH |
1958 | } |
1959 | ||
d69b042f BS |
1960 | /* |
1961 | * Currently used to update mapped file statistics, but the routine can be | |
1962 | * generalized to update other statistics as well. | |
32047e2a KH |
1963 | * |
1964 | * Notes: Race condition | |
1965 | * | |
1966 | * We usually use page_cgroup_lock() for accessing page_cgroup member but | |
1967 | * it tends to be costly. But considering some conditions, we doesn't need | |
1968 | * to do so _always_. | |
1969 | * | |
1970 | * Considering "charge", lock_page_cgroup() is not required because all | |
1971 | * file-stat operations happen after a page is attached to radix-tree. There | |
1972 | * are no race with "charge". | |
1973 | * | |
1974 | * Considering "uncharge", we know that memcg doesn't clear pc->mem_cgroup | |
1975 | * at "uncharge" intentionally. So, we always see valid pc->mem_cgroup even | |
1976 | * if there are race with "uncharge". Statistics itself is properly handled | |
1977 | * by flags. | |
1978 | * | |
1979 | * Considering "move", this is an only case we see a race. To make the race | |
619d094b KH |
1980 | * small, we check mm->moving_account and detect there are possibility of race |
1981 | * If there is, we take a lock. | |
d69b042f | 1982 | */ |
26174efd | 1983 | |
89c06bd5 KH |
1984 | void __mem_cgroup_begin_update_page_stat(struct page *page, |
1985 | bool *locked, unsigned long *flags) | |
1986 | { | |
1987 | struct mem_cgroup *memcg; | |
1988 | struct page_cgroup *pc; | |
1989 | ||
1990 | pc = lookup_page_cgroup(page); | |
1991 | again: | |
1992 | memcg = pc->mem_cgroup; | |
1993 | if (unlikely(!memcg || !PageCgroupUsed(pc))) | |
1994 | return; | |
1995 | /* | |
1996 | * If this memory cgroup is not under account moving, we don't | |
da92c47d | 1997 | * need to take move_lock_mem_cgroup(). Because we already hold |
89c06bd5 | 1998 | * rcu_read_lock(), any calls to move_account will be delayed until |
13fd1dd9 | 1999 | * rcu_read_unlock() if mem_cgroup_stolen() == true. |
89c06bd5 | 2000 | */ |
13fd1dd9 | 2001 | if (!mem_cgroup_stolen(memcg)) |
89c06bd5 KH |
2002 | return; |
2003 | ||
2004 | move_lock_mem_cgroup(memcg, flags); | |
2005 | if (memcg != pc->mem_cgroup || !PageCgroupUsed(pc)) { | |
2006 | move_unlock_mem_cgroup(memcg, flags); | |
2007 | goto again; | |
2008 | } | |
2009 | *locked = true; | |
2010 | } | |
2011 | ||
2012 | void __mem_cgroup_end_update_page_stat(struct page *page, unsigned long *flags) | |
2013 | { | |
2014 | struct page_cgroup *pc = lookup_page_cgroup(page); | |
2015 | ||
2016 | /* | |
2017 | * It's guaranteed that pc->mem_cgroup never changes while | |
2018 | * lock is held because a routine modifies pc->mem_cgroup | |
da92c47d | 2019 | * should take move_lock_mem_cgroup(). |
89c06bd5 KH |
2020 | */ |
2021 | move_unlock_mem_cgroup(pc->mem_cgroup, flags); | |
2022 | } | |
2023 | ||
2a7106f2 GT |
2024 | void mem_cgroup_update_page_stat(struct page *page, |
2025 | enum mem_cgroup_page_stat_item idx, int val) | |
d69b042f | 2026 | { |
c0ff4b85 | 2027 | struct mem_cgroup *memcg; |
32047e2a | 2028 | struct page_cgroup *pc = lookup_page_cgroup(page); |
dbd4ea78 | 2029 | unsigned long uninitialized_var(flags); |
d69b042f | 2030 | |
cfa44946 | 2031 | if (mem_cgroup_disabled()) |
d69b042f | 2032 | return; |
89c06bd5 | 2033 | |
c0ff4b85 R |
2034 | memcg = pc->mem_cgroup; |
2035 | if (unlikely(!memcg || !PageCgroupUsed(pc))) | |
89c06bd5 | 2036 | return; |
26174efd | 2037 | |
26174efd | 2038 | switch (idx) { |
2a7106f2 | 2039 | case MEMCG_NR_FILE_MAPPED: |
2a7106f2 | 2040 | idx = MEM_CGROUP_STAT_FILE_MAPPED; |
26174efd KH |
2041 | break; |
2042 | default: | |
2043 | BUG(); | |
8725d541 | 2044 | } |
d69b042f | 2045 | |
c0ff4b85 | 2046 | this_cpu_add(memcg->stat->count[idx], val); |
d69b042f | 2047 | } |
26174efd | 2048 | |
cdec2e42 KH |
2049 | /* |
2050 | * size of first charge trial. "32" comes from vmscan.c's magic value. | |
2051 | * TODO: maybe necessary to use big numbers in big irons. | |
2052 | */ | |
7ec99d62 | 2053 | #define CHARGE_BATCH 32U |
cdec2e42 KH |
2054 | struct memcg_stock_pcp { |
2055 | struct mem_cgroup *cached; /* this never be root cgroup */ | |
11c9ea4e | 2056 | unsigned int nr_pages; |
cdec2e42 | 2057 | struct work_struct work; |
26fe6168 | 2058 | unsigned long flags; |
a0db00fc | 2059 | #define FLUSHING_CACHED_CHARGE 0 |
cdec2e42 KH |
2060 | }; |
2061 | static DEFINE_PER_CPU(struct memcg_stock_pcp, memcg_stock); | |
9f50fad6 | 2062 | static DEFINE_MUTEX(percpu_charge_mutex); |
cdec2e42 KH |
2063 | |
2064 | /* | |
11c9ea4e | 2065 | * Try to consume stocked charge on this cpu. If success, one page is consumed |
cdec2e42 KH |
2066 | * from local stock and true is returned. If the stock is 0 or charges from a |
2067 | * cgroup which is not current target, returns false. This stock will be | |
2068 | * refilled. | |
2069 | */ | |
c0ff4b85 | 2070 | static bool consume_stock(struct mem_cgroup *memcg) |
cdec2e42 KH |
2071 | { |
2072 | struct memcg_stock_pcp *stock; | |
2073 | bool ret = true; | |
2074 | ||
2075 | stock = &get_cpu_var(memcg_stock); | |
c0ff4b85 | 2076 | if (memcg == stock->cached && stock->nr_pages) |
11c9ea4e | 2077 | stock->nr_pages--; |
cdec2e42 KH |
2078 | else /* need to call res_counter_charge */ |
2079 | ret = false; | |
2080 | put_cpu_var(memcg_stock); | |
2081 | return ret; | |
2082 | } | |
2083 | ||
2084 | /* | |
2085 | * Returns stocks cached in percpu to res_counter and reset cached information. | |
2086 | */ | |
2087 | static void drain_stock(struct memcg_stock_pcp *stock) | |
2088 | { | |
2089 | struct mem_cgroup *old = stock->cached; | |
2090 | ||
11c9ea4e JW |
2091 | if (stock->nr_pages) { |
2092 | unsigned long bytes = stock->nr_pages * PAGE_SIZE; | |
2093 | ||
2094 | res_counter_uncharge(&old->res, bytes); | |
cdec2e42 | 2095 | if (do_swap_account) |
11c9ea4e JW |
2096 | res_counter_uncharge(&old->memsw, bytes); |
2097 | stock->nr_pages = 0; | |
cdec2e42 KH |
2098 | } |
2099 | stock->cached = NULL; | |
cdec2e42 KH |
2100 | } |
2101 | ||
2102 | /* | |
2103 | * This must be called under preempt disabled or must be called by | |
2104 | * a thread which is pinned to local cpu. | |
2105 | */ | |
2106 | static void drain_local_stock(struct work_struct *dummy) | |
2107 | { | |
2108 | struct memcg_stock_pcp *stock = &__get_cpu_var(memcg_stock); | |
2109 | drain_stock(stock); | |
26fe6168 | 2110 | clear_bit(FLUSHING_CACHED_CHARGE, &stock->flags); |
cdec2e42 KH |
2111 | } |
2112 | ||
2113 | /* | |
2114 | * Cache charges(val) which is from res_counter, to local per_cpu area. | |
320cc51d | 2115 | * This will be consumed by consume_stock() function, later. |
cdec2e42 | 2116 | */ |
c0ff4b85 | 2117 | static void refill_stock(struct mem_cgroup *memcg, unsigned int nr_pages) |
cdec2e42 KH |
2118 | { |
2119 | struct memcg_stock_pcp *stock = &get_cpu_var(memcg_stock); | |
2120 | ||
c0ff4b85 | 2121 | if (stock->cached != memcg) { /* reset if necessary */ |
cdec2e42 | 2122 | drain_stock(stock); |
c0ff4b85 | 2123 | stock->cached = memcg; |
cdec2e42 | 2124 | } |
11c9ea4e | 2125 | stock->nr_pages += nr_pages; |
cdec2e42 KH |
2126 | put_cpu_var(memcg_stock); |
2127 | } | |
2128 | ||
2129 | /* | |
c0ff4b85 | 2130 | * Drains all per-CPU charge caches for given root_memcg resp. subtree |
d38144b7 MH |
2131 | * of the hierarchy under it. sync flag says whether we should block |
2132 | * until the work is done. | |
cdec2e42 | 2133 | */ |
c0ff4b85 | 2134 | static void drain_all_stock(struct mem_cgroup *root_memcg, bool sync) |
cdec2e42 | 2135 | { |
26fe6168 | 2136 | int cpu, curcpu; |
d38144b7 | 2137 | |
cdec2e42 | 2138 | /* Notify other cpus that system-wide "drain" is running */ |
cdec2e42 | 2139 | get_online_cpus(); |
5af12d0e | 2140 | curcpu = get_cpu(); |
cdec2e42 KH |
2141 | for_each_online_cpu(cpu) { |
2142 | struct memcg_stock_pcp *stock = &per_cpu(memcg_stock, cpu); | |
c0ff4b85 | 2143 | struct mem_cgroup *memcg; |
26fe6168 | 2144 | |
c0ff4b85 R |
2145 | memcg = stock->cached; |
2146 | if (!memcg || !stock->nr_pages) | |
26fe6168 | 2147 | continue; |
c0ff4b85 | 2148 | if (!mem_cgroup_same_or_subtree(root_memcg, memcg)) |
3e92041d | 2149 | continue; |
d1a05b69 MH |
2150 | if (!test_and_set_bit(FLUSHING_CACHED_CHARGE, &stock->flags)) { |
2151 | if (cpu == curcpu) | |
2152 | drain_local_stock(&stock->work); | |
2153 | else | |
2154 | schedule_work_on(cpu, &stock->work); | |
2155 | } | |
cdec2e42 | 2156 | } |
5af12d0e | 2157 | put_cpu(); |
d38144b7 MH |
2158 | |
2159 | if (!sync) | |
2160 | goto out; | |
2161 | ||
2162 | for_each_online_cpu(cpu) { | |
2163 | struct memcg_stock_pcp *stock = &per_cpu(memcg_stock, cpu); | |
9f50fad6 | 2164 | if (test_bit(FLUSHING_CACHED_CHARGE, &stock->flags)) |
d38144b7 MH |
2165 | flush_work(&stock->work); |
2166 | } | |
2167 | out: | |
cdec2e42 | 2168 | put_online_cpus(); |
d38144b7 MH |
2169 | } |
2170 | ||
2171 | /* | |
2172 | * Tries to drain stocked charges in other cpus. This function is asynchronous | |
2173 | * and just put a work per cpu for draining localy on each cpu. Caller can | |
2174 | * expects some charges will be back to res_counter later but cannot wait for | |
2175 | * it. | |
2176 | */ | |
c0ff4b85 | 2177 | static void drain_all_stock_async(struct mem_cgroup *root_memcg) |
d38144b7 | 2178 | { |
9f50fad6 MH |
2179 | /* |
2180 | * If someone calls draining, avoid adding more kworker runs. | |
2181 | */ | |
2182 | if (!mutex_trylock(&percpu_charge_mutex)) | |
2183 | return; | |
c0ff4b85 | 2184 | drain_all_stock(root_memcg, false); |
9f50fad6 | 2185 | mutex_unlock(&percpu_charge_mutex); |
cdec2e42 KH |
2186 | } |
2187 | ||
2188 | /* This is a synchronous drain interface. */ | |
c0ff4b85 | 2189 | static void drain_all_stock_sync(struct mem_cgroup *root_memcg) |
cdec2e42 KH |
2190 | { |
2191 | /* called when force_empty is called */ | |
9f50fad6 | 2192 | mutex_lock(&percpu_charge_mutex); |
c0ff4b85 | 2193 | drain_all_stock(root_memcg, true); |
9f50fad6 | 2194 | mutex_unlock(&percpu_charge_mutex); |
cdec2e42 KH |
2195 | } |
2196 | ||
711d3d2c KH |
2197 | /* |
2198 | * This function drains percpu counter value from DEAD cpu and | |
2199 | * move it to local cpu. Note that this function can be preempted. | |
2200 | */ | |
c0ff4b85 | 2201 | static void mem_cgroup_drain_pcp_counter(struct mem_cgroup *memcg, int cpu) |
711d3d2c KH |
2202 | { |
2203 | int i; | |
2204 | ||
c0ff4b85 | 2205 | spin_lock(&memcg->pcp_counter_lock); |
6104621d | 2206 | for (i = 0; i < MEM_CGROUP_STAT_NSTATS; i++) { |
c0ff4b85 | 2207 | long x = per_cpu(memcg->stat->count[i], cpu); |
711d3d2c | 2208 | |
c0ff4b85 R |
2209 | per_cpu(memcg->stat->count[i], cpu) = 0; |
2210 | memcg->nocpu_base.count[i] += x; | |
711d3d2c | 2211 | } |
e9f8974f | 2212 | for (i = 0; i < MEM_CGROUP_EVENTS_NSTATS; i++) { |
c0ff4b85 | 2213 | unsigned long x = per_cpu(memcg->stat->events[i], cpu); |
e9f8974f | 2214 | |
c0ff4b85 R |
2215 | per_cpu(memcg->stat->events[i], cpu) = 0; |
2216 | memcg->nocpu_base.events[i] += x; | |
e9f8974f | 2217 | } |
c0ff4b85 | 2218 | spin_unlock(&memcg->pcp_counter_lock); |
711d3d2c KH |
2219 | } |
2220 | ||
2221 | static int __cpuinit memcg_cpu_hotplug_callback(struct notifier_block *nb, | |
cdec2e42 KH |
2222 | unsigned long action, |
2223 | void *hcpu) | |
2224 | { | |
2225 | int cpu = (unsigned long)hcpu; | |
2226 | struct memcg_stock_pcp *stock; | |
711d3d2c | 2227 | struct mem_cgroup *iter; |
cdec2e42 | 2228 | |
619d094b | 2229 | if (action == CPU_ONLINE) |
1489ebad | 2230 | return NOTIFY_OK; |
1489ebad | 2231 | |
d833049b | 2232 | if (action != CPU_DEAD && action != CPU_DEAD_FROZEN) |
cdec2e42 | 2233 | return NOTIFY_OK; |
711d3d2c | 2234 | |
9f3a0d09 | 2235 | for_each_mem_cgroup(iter) |
711d3d2c KH |
2236 | mem_cgroup_drain_pcp_counter(iter, cpu); |
2237 | ||
cdec2e42 KH |
2238 | stock = &per_cpu(memcg_stock, cpu); |
2239 | drain_stock(stock); | |
2240 | return NOTIFY_OK; | |
2241 | } | |
2242 | ||
4b534334 KH |
2243 | |
2244 | /* See __mem_cgroup_try_charge() for details */ | |
2245 | enum { | |
2246 | CHARGE_OK, /* success */ | |
2247 | CHARGE_RETRY, /* need to retry but retry is not bad */ | |
2248 | CHARGE_NOMEM, /* we can't do more. return -ENOMEM */ | |
2249 | CHARGE_WOULDBLOCK, /* GFP_WAIT wasn't set and no enough res. */ | |
2250 | CHARGE_OOM_DIE, /* the current is killed because of OOM */ | |
2251 | }; | |
2252 | ||
c0ff4b85 | 2253 | static int mem_cgroup_do_charge(struct mem_cgroup *memcg, gfp_t gfp_mask, |
7ec99d62 | 2254 | unsigned int nr_pages, bool oom_check) |
4b534334 | 2255 | { |
7ec99d62 | 2256 | unsigned long csize = nr_pages * PAGE_SIZE; |
4b534334 KH |
2257 | struct mem_cgroup *mem_over_limit; |
2258 | struct res_counter *fail_res; | |
2259 | unsigned long flags = 0; | |
2260 | int ret; | |
2261 | ||
c0ff4b85 | 2262 | ret = res_counter_charge(&memcg->res, csize, &fail_res); |
4b534334 KH |
2263 | |
2264 | if (likely(!ret)) { | |
2265 | if (!do_swap_account) | |
2266 | return CHARGE_OK; | |
c0ff4b85 | 2267 | ret = res_counter_charge(&memcg->memsw, csize, &fail_res); |
4b534334 KH |
2268 | if (likely(!ret)) |
2269 | return CHARGE_OK; | |
2270 | ||
c0ff4b85 | 2271 | res_counter_uncharge(&memcg->res, csize); |
4b534334 KH |
2272 | mem_over_limit = mem_cgroup_from_res_counter(fail_res, memsw); |
2273 | flags |= MEM_CGROUP_RECLAIM_NOSWAP; | |
2274 | } else | |
2275 | mem_over_limit = mem_cgroup_from_res_counter(fail_res, res); | |
9221edb7 | 2276 | /* |
7ec99d62 JW |
2277 | * nr_pages can be either a huge page (HPAGE_PMD_NR), a batch |
2278 | * of regular pages (CHARGE_BATCH), or a single regular page (1). | |
9221edb7 JW |
2279 | * |
2280 | * Never reclaim on behalf of optional batching, retry with a | |
2281 | * single page instead. | |
2282 | */ | |
7ec99d62 | 2283 | if (nr_pages == CHARGE_BATCH) |
4b534334 KH |
2284 | return CHARGE_RETRY; |
2285 | ||
2286 | if (!(gfp_mask & __GFP_WAIT)) | |
2287 | return CHARGE_WOULDBLOCK; | |
2288 | ||
5660048c | 2289 | ret = mem_cgroup_reclaim(mem_over_limit, gfp_mask, flags); |
7ec99d62 | 2290 | if (mem_cgroup_margin(mem_over_limit) >= nr_pages) |
19942822 | 2291 | return CHARGE_RETRY; |
4b534334 | 2292 | /* |
19942822 JW |
2293 | * Even though the limit is exceeded at this point, reclaim |
2294 | * may have been able to free some pages. Retry the charge | |
2295 | * before killing the task. | |
2296 | * | |
2297 | * Only for regular pages, though: huge pages are rather | |
2298 | * unlikely to succeed so close to the limit, and we fall back | |
2299 | * to regular pages anyway in case of failure. | |
4b534334 | 2300 | */ |
7ec99d62 | 2301 | if (nr_pages == 1 && ret) |
4b534334 KH |
2302 | return CHARGE_RETRY; |
2303 | ||
2304 | /* | |
2305 | * At task move, charge accounts can be doubly counted. So, it's | |
2306 | * better to wait until the end of task_move if something is going on. | |
2307 | */ | |
2308 | if (mem_cgroup_wait_acct_move(mem_over_limit)) | |
2309 | return CHARGE_RETRY; | |
2310 | ||
2311 | /* If we don't need to call oom-killer at el, return immediately */ | |
2312 | if (!oom_check) | |
2313 | return CHARGE_NOMEM; | |
2314 | /* check OOM */ | |
e845e199 | 2315 | if (!mem_cgroup_handle_oom(mem_over_limit, gfp_mask, get_order(csize))) |
4b534334 KH |
2316 | return CHARGE_OOM_DIE; |
2317 | ||
2318 | return CHARGE_RETRY; | |
2319 | } | |
2320 | ||
f817ed48 | 2321 | /* |
38c5d72f KH |
2322 | * __mem_cgroup_try_charge() does |
2323 | * 1. detect memcg to be charged against from passed *mm and *ptr, | |
2324 | * 2. update res_counter | |
2325 | * 3. call memory reclaim if necessary. | |
2326 | * | |
2327 | * In some special case, if the task is fatal, fatal_signal_pending() or | |
2328 | * has TIF_MEMDIE, this function returns -EINTR while writing root_mem_cgroup | |
2329 | * to *ptr. There are two reasons for this. 1: fatal threads should quit as soon | |
2330 | * as possible without any hazards. 2: all pages should have a valid | |
2331 | * pc->mem_cgroup. If mm is NULL and the caller doesn't pass a valid memcg | |
2332 | * pointer, that is treated as a charge to root_mem_cgroup. | |
2333 | * | |
2334 | * So __mem_cgroup_try_charge() will return | |
2335 | * 0 ... on success, filling *ptr with a valid memcg pointer. | |
2336 | * -ENOMEM ... charge failure because of resource limits. | |
2337 | * -EINTR ... if thread is fatal. *ptr is filled with root_mem_cgroup. | |
2338 | * | |
2339 | * Unlike the exported interface, an "oom" parameter is added. if oom==true, | |
2340 | * the oom-killer can be invoked. | |
8a9f3ccd | 2341 | */ |
f817ed48 | 2342 | static int __mem_cgroup_try_charge(struct mm_struct *mm, |
ec168510 | 2343 | gfp_t gfp_mask, |
7ec99d62 | 2344 | unsigned int nr_pages, |
c0ff4b85 | 2345 | struct mem_cgroup **ptr, |
7ec99d62 | 2346 | bool oom) |
8a9f3ccd | 2347 | { |
7ec99d62 | 2348 | unsigned int batch = max(CHARGE_BATCH, nr_pages); |
4b534334 | 2349 | int nr_oom_retries = MEM_CGROUP_RECLAIM_RETRIES; |
c0ff4b85 | 2350 | struct mem_cgroup *memcg = NULL; |
4b534334 | 2351 | int ret; |
a636b327 | 2352 | |
867578cb KH |
2353 | /* |
2354 | * Unlike gloval-vm's OOM-kill, we're not in memory shortage | |
2355 | * in system level. So, allow to go ahead dying process in addition to | |
2356 | * MEMDIE process. | |
2357 | */ | |
2358 | if (unlikely(test_thread_flag(TIF_MEMDIE) | |
2359 | || fatal_signal_pending(current))) | |
2360 | goto bypass; | |
a636b327 | 2361 | |
8a9f3ccd | 2362 | /* |
3be91277 HD |
2363 | * We always charge the cgroup the mm_struct belongs to. |
2364 | * The mm_struct's mem_cgroup changes on task migration if the | |
8a9f3ccd | 2365 | * thread group leader migrates. It's possible that mm is not |
24467cac | 2366 | * set, if so charge the root memcg (happens for pagecache usage). |
8a9f3ccd | 2367 | */ |
c0ff4b85 | 2368 | if (!*ptr && !mm) |
38c5d72f | 2369 | *ptr = root_mem_cgroup; |
f75ca962 | 2370 | again: |
c0ff4b85 R |
2371 | if (*ptr) { /* css should be a valid one */ |
2372 | memcg = *ptr; | |
2373 | VM_BUG_ON(css_is_removed(&memcg->css)); | |
2374 | if (mem_cgroup_is_root(memcg)) | |
f75ca962 | 2375 | goto done; |
c0ff4b85 | 2376 | if (nr_pages == 1 && consume_stock(memcg)) |
f75ca962 | 2377 | goto done; |
c0ff4b85 | 2378 | css_get(&memcg->css); |
4b534334 | 2379 | } else { |
f75ca962 | 2380 | struct task_struct *p; |
54595fe2 | 2381 | |
f75ca962 KH |
2382 | rcu_read_lock(); |
2383 | p = rcu_dereference(mm->owner); | |
f75ca962 | 2384 | /* |
ebb76ce1 | 2385 | * Because we don't have task_lock(), "p" can exit. |
c0ff4b85 | 2386 | * In that case, "memcg" can point to root or p can be NULL with |
ebb76ce1 KH |
2387 | * race with swapoff. Then, we have small risk of mis-accouning. |
2388 | * But such kind of mis-account by race always happens because | |
2389 | * we don't have cgroup_mutex(). It's overkill and we allo that | |
2390 | * small race, here. | |
2391 | * (*) swapoff at el will charge against mm-struct not against | |
2392 | * task-struct. So, mm->owner can be NULL. | |
f75ca962 | 2393 | */ |
c0ff4b85 | 2394 | memcg = mem_cgroup_from_task(p); |
38c5d72f KH |
2395 | if (!memcg) |
2396 | memcg = root_mem_cgroup; | |
2397 | if (mem_cgroup_is_root(memcg)) { | |
f75ca962 KH |
2398 | rcu_read_unlock(); |
2399 | goto done; | |
2400 | } | |
c0ff4b85 | 2401 | if (nr_pages == 1 && consume_stock(memcg)) { |
f75ca962 KH |
2402 | /* |
2403 | * It seems dagerous to access memcg without css_get(). | |
2404 | * But considering how consume_stok works, it's not | |
2405 | * necessary. If consume_stock success, some charges | |
2406 | * from this memcg are cached on this cpu. So, we | |
2407 | * don't need to call css_get()/css_tryget() before | |
2408 | * calling consume_stock(). | |
2409 | */ | |
2410 | rcu_read_unlock(); | |
2411 | goto done; | |
2412 | } | |
2413 | /* after here, we may be blocked. we need to get refcnt */ | |
c0ff4b85 | 2414 | if (!css_tryget(&memcg->css)) { |
f75ca962 KH |
2415 | rcu_read_unlock(); |
2416 | goto again; | |
2417 | } | |
2418 | rcu_read_unlock(); | |
2419 | } | |
8a9f3ccd | 2420 | |
4b534334 KH |
2421 | do { |
2422 | bool oom_check; | |
7a81b88c | 2423 | |
4b534334 | 2424 | /* If killed, bypass charge */ |
f75ca962 | 2425 | if (fatal_signal_pending(current)) { |
c0ff4b85 | 2426 | css_put(&memcg->css); |
4b534334 | 2427 | goto bypass; |
f75ca962 | 2428 | } |
6d61ef40 | 2429 | |
4b534334 KH |
2430 | oom_check = false; |
2431 | if (oom && !nr_oom_retries) { | |
2432 | oom_check = true; | |
2433 | nr_oom_retries = MEM_CGROUP_RECLAIM_RETRIES; | |
cdec2e42 | 2434 | } |
66e1707b | 2435 | |
c0ff4b85 | 2436 | ret = mem_cgroup_do_charge(memcg, gfp_mask, batch, oom_check); |
4b534334 KH |
2437 | switch (ret) { |
2438 | case CHARGE_OK: | |
2439 | break; | |
2440 | case CHARGE_RETRY: /* not in OOM situation but retry */ | |
7ec99d62 | 2441 | batch = nr_pages; |
c0ff4b85 R |
2442 | css_put(&memcg->css); |
2443 | memcg = NULL; | |
f75ca962 | 2444 | goto again; |
4b534334 | 2445 | case CHARGE_WOULDBLOCK: /* !__GFP_WAIT */ |
c0ff4b85 | 2446 | css_put(&memcg->css); |
4b534334 KH |
2447 | goto nomem; |
2448 | case CHARGE_NOMEM: /* OOM routine works */ | |
f75ca962 | 2449 | if (!oom) { |
c0ff4b85 | 2450 | css_put(&memcg->css); |
867578cb | 2451 | goto nomem; |
f75ca962 | 2452 | } |
4b534334 KH |
2453 | /* If oom, we never return -ENOMEM */ |
2454 | nr_oom_retries--; | |
2455 | break; | |
2456 | case CHARGE_OOM_DIE: /* Killed by OOM Killer */ | |
c0ff4b85 | 2457 | css_put(&memcg->css); |
867578cb | 2458 | goto bypass; |
66e1707b | 2459 | } |
4b534334 KH |
2460 | } while (ret != CHARGE_OK); |
2461 | ||
7ec99d62 | 2462 | if (batch > nr_pages) |
c0ff4b85 R |
2463 | refill_stock(memcg, batch - nr_pages); |
2464 | css_put(&memcg->css); | |
0c3e73e8 | 2465 | done: |
c0ff4b85 | 2466 | *ptr = memcg; |
7a81b88c KH |
2467 | return 0; |
2468 | nomem: | |
c0ff4b85 | 2469 | *ptr = NULL; |
7a81b88c | 2470 | return -ENOMEM; |
867578cb | 2471 | bypass: |
38c5d72f KH |
2472 | *ptr = root_mem_cgroup; |
2473 | return -EINTR; | |
7a81b88c | 2474 | } |
8a9f3ccd | 2475 | |
a3032a2c DN |
2476 | /* |
2477 | * Somemtimes we have to undo a charge we got by try_charge(). | |
2478 | * This function is for that and do uncharge, put css's refcnt. | |
2479 | * gotten by try_charge(). | |
2480 | */ | |
c0ff4b85 | 2481 | static void __mem_cgroup_cancel_charge(struct mem_cgroup *memcg, |
e7018b8d | 2482 | unsigned int nr_pages) |
a3032a2c | 2483 | { |
c0ff4b85 | 2484 | if (!mem_cgroup_is_root(memcg)) { |
e7018b8d JW |
2485 | unsigned long bytes = nr_pages * PAGE_SIZE; |
2486 | ||
c0ff4b85 | 2487 | res_counter_uncharge(&memcg->res, bytes); |
a3032a2c | 2488 | if (do_swap_account) |
c0ff4b85 | 2489 | res_counter_uncharge(&memcg->memsw, bytes); |
a3032a2c | 2490 | } |
854ffa8d DN |
2491 | } |
2492 | ||
d01dd17f KH |
2493 | /* |
2494 | * Cancel chrages in this cgroup....doesn't propagate to parent cgroup. | |
2495 | * This is useful when moving usage to parent cgroup. | |
2496 | */ | |
2497 | static void __mem_cgroup_cancel_local_charge(struct mem_cgroup *memcg, | |
2498 | unsigned int nr_pages) | |
2499 | { | |
2500 | unsigned long bytes = nr_pages * PAGE_SIZE; | |
2501 | ||
2502 | if (mem_cgroup_is_root(memcg)) | |
2503 | return; | |
2504 | ||
2505 | res_counter_uncharge_until(&memcg->res, memcg->res.parent, bytes); | |
2506 | if (do_swap_account) | |
2507 | res_counter_uncharge_until(&memcg->memsw, | |
2508 | memcg->memsw.parent, bytes); | |
2509 | } | |
2510 | ||
a3b2d692 KH |
2511 | /* |
2512 | * A helper function to get mem_cgroup from ID. must be called under | |
2513 | * rcu_read_lock(). The caller must check css_is_removed() or some if | |
2514 | * it's concern. (dropping refcnt from swap can be called against removed | |
2515 | * memcg.) | |
2516 | */ | |
2517 | static struct mem_cgroup *mem_cgroup_lookup(unsigned short id) | |
2518 | { | |
2519 | struct cgroup_subsys_state *css; | |
2520 | ||
2521 | /* ID 0 is unused ID */ | |
2522 | if (!id) | |
2523 | return NULL; | |
2524 | css = css_lookup(&mem_cgroup_subsys, id); | |
2525 | if (!css) | |
2526 | return NULL; | |
b2145145 | 2527 | return mem_cgroup_from_css(css); |
a3b2d692 KH |
2528 | } |
2529 | ||
e42d9d5d | 2530 | struct mem_cgroup *try_get_mem_cgroup_from_page(struct page *page) |
b5a84319 | 2531 | { |
c0ff4b85 | 2532 | struct mem_cgroup *memcg = NULL; |
3c776e64 | 2533 | struct page_cgroup *pc; |
a3b2d692 | 2534 | unsigned short id; |
b5a84319 KH |
2535 | swp_entry_t ent; |
2536 | ||
3c776e64 DN |
2537 | VM_BUG_ON(!PageLocked(page)); |
2538 | ||
3c776e64 | 2539 | pc = lookup_page_cgroup(page); |
c0bd3f63 | 2540 | lock_page_cgroup(pc); |
a3b2d692 | 2541 | if (PageCgroupUsed(pc)) { |
c0ff4b85 R |
2542 | memcg = pc->mem_cgroup; |
2543 | if (memcg && !css_tryget(&memcg->css)) | |
2544 | memcg = NULL; | |
e42d9d5d | 2545 | } else if (PageSwapCache(page)) { |
3c776e64 | 2546 | ent.val = page_private(page); |
9fb4b7cc | 2547 | id = lookup_swap_cgroup_id(ent); |
a3b2d692 | 2548 | rcu_read_lock(); |
c0ff4b85 R |
2549 | memcg = mem_cgroup_lookup(id); |
2550 | if (memcg && !css_tryget(&memcg->css)) | |
2551 | memcg = NULL; | |
a3b2d692 | 2552 | rcu_read_unlock(); |
3c776e64 | 2553 | } |
c0bd3f63 | 2554 | unlock_page_cgroup(pc); |
c0ff4b85 | 2555 | return memcg; |
b5a84319 KH |
2556 | } |
2557 | ||
c0ff4b85 | 2558 | static void __mem_cgroup_commit_charge(struct mem_cgroup *memcg, |
5564e88b | 2559 | struct page *page, |
7ec99d62 | 2560 | unsigned int nr_pages, |
9ce70c02 HD |
2561 | enum charge_type ctype, |
2562 | bool lrucare) | |
7a81b88c | 2563 | { |
ce587e65 | 2564 | struct page_cgroup *pc = lookup_page_cgroup(page); |
9ce70c02 | 2565 | struct zone *uninitialized_var(zone); |
fa9add64 | 2566 | struct lruvec *lruvec; |
9ce70c02 | 2567 | bool was_on_lru = false; |
b2402857 | 2568 | bool anon; |
9ce70c02 | 2569 | |
ca3e0214 | 2570 | lock_page_cgroup(pc); |
90deb788 | 2571 | VM_BUG_ON(PageCgroupUsed(pc)); |
ca3e0214 KH |
2572 | /* |
2573 | * we don't need page_cgroup_lock about tail pages, becase they are not | |
2574 | * accessed by any other context at this point. | |
2575 | */ | |
9ce70c02 HD |
2576 | |
2577 | /* | |
2578 | * In some cases, SwapCache and FUSE(splice_buf->radixtree), the page | |
2579 | * may already be on some other mem_cgroup's LRU. Take care of it. | |
2580 | */ | |
2581 | if (lrucare) { | |
2582 | zone = page_zone(page); | |
2583 | spin_lock_irq(&zone->lru_lock); | |
2584 | if (PageLRU(page)) { | |
fa9add64 | 2585 | lruvec = mem_cgroup_zone_lruvec(zone, pc->mem_cgroup); |
9ce70c02 | 2586 | ClearPageLRU(page); |
fa9add64 | 2587 | del_page_from_lru_list(page, lruvec, page_lru(page)); |
9ce70c02 HD |
2588 | was_on_lru = true; |
2589 | } | |
2590 | } | |
2591 | ||
c0ff4b85 | 2592 | pc->mem_cgroup = memcg; |
261fb61a KH |
2593 | /* |
2594 | * We access a page_cgroup asynchronously without lock_page_cgroup(). | |
2595 | * Especially when a page_cgroup is taken from a page, pc->mem_cgroup | |
2596 | * is accessed after testing USED bit. To make pc->mem_cgroup visible | |
2597 | * before USED bit, we need memory barrier here. | |
2598 | * See mem_cgroup_add_lru_list(), etc. | |
2599 | */ | |
08e552c6 | 2600 | smp_wmb(); |
b2402857 | 2601 | SetPageCgroupUsed(pc); |
3be91277 | 2602 | |
9ce70c02 HD |
2603 | if (lrucare) { |
2604 | if (was_on_lru) { | |
fa9add64 | 2605 | lruvec = mem_cgroup_zone_lruvec(zone, pc->mem_cgroup); |
9ce70c02 HD |
2606 | VM_BUG_ON(PageLRU(page)); |
2607 | SetPageLRU(page); | |
fa9add64 | 2608 | add_page_to_lru_list(page, lruvec, page_lru(page)); |
9ce70c02 HD |
2609 | } |
2610 | spin_unlock_irq(&zone->lru_lock); | |
2611 | } | |
2612 | ||
41326c17 | 2613 | if (ctype == MEM_CGROUP_CHARGE_TYPE_ANON) |
b2402857 KH |
2614 | anon = true; |
2615 | else | |
2616 | anon = false; | |
2617 | ||
2618 | mem_cgroup_charge_statistics(memcg, anon, nr_pages); | |
52d4b9ac | 2619 | unlock_page_cgroup(pc); |
9ce70c02 | 2620 | |
430e4863 KH |
2621 | /* |
2622 | * "charge_statistics" updated event counter. Then, check it. | |
2623 | * Insert ancestor (and ancestor's ancestors), to softlimit RB-tree. | |
2624 | * if they exceeds softlimit. | |
2625 | */ | |
c0ff4b85 | 2626 | memcg_check_events(memcg, page); |
7a81b88c | 2627 | } |
66e1707b | 2628 | |
ca3e0214 KH |
2629 | #ifdef CONFIG_TRANSPARENT_HUGEPAGE |
2630 | ||
a0db00fc | 2631 | #define PCGF_NOCOPY_AT_SPLIT (1 << PCG_LOCK | 1 << PCG_MIGRATION) |
ca3e0214 KH |
2632 | /* |
2633 | * Because tail pages are not marked as "used", set it. We're under | |
e94c8a9c KH |
2634 | * zone->lru_lock, 'splitting on pmd' and compound_lock. |
2635 | * charge/uncharge will be never happen and move_account() is done under | |
2636 | * compound_lock(), so we don't have to take care of races. | |
ca3e0214 | 2637 | */ |
e94c8a9c | 2638 | void mem_cgroup_split_huge_fixup(struct page *head) |
ca3e0214 KH |
2639 | { |
2640 | struct page_cgroup *head_pc = lookup_page_cgroup(head); | |
e94c8a9c KH |
2641 | struct page_cgroup *pc; |
2642 | int i; | |
ca3e0214 | 2643 | |
3d37c4a9 KH |
2644 | if (mem_cgroup_disabled()) |
2645 | return; | |
e94c8a9c KH |
2646 | for (i = 1; i < HPAGE_PMD_NR; i++) { |
2647 | pc = head_pc + i; | |
2648 | pc->mem_cgroup = head_pc->mem_cgroup; | |
2649 | smp_wmb();/* see __commit_charge() */ | |
e94c8a9c KH |
2650 | pc->flags = head_pc->flags & ~PCGF_NOCOPY_AT_SPLIT; |
2651 | } | |
ca3e0214 | 2652 | } |
12d27107 | 2653 | #endif /* CONFIG_TRANSPARENT_HUGEPAGE */ |
ca3e0214 | 2654 | |
f817ed48 | 2655 | /** |
de3638d9 | 2656 | * mem_cgroup_move_account - move account of the page |
5564e88b | 2657 | * @page: the page |
7ec99d62 | 2658 | * @nr_pages: number of regular pages (>1 for huge pages) |
f817ed48 KH |
2659 | * @pc: page_cgroup of the page. |
2660 | * @from: mem_cgroup which the page is moved from. | |
2661 | * @to: mem_cgroup which the page is moved to. @from != @to. | |
2662 | * | |
2663 | * The caller must confirm following. | |
08e552c6 | 2664 | * - page is not on LRU (isolate_page() is useful.) |
7ec99d62 | 2665 | * - compound_lock is held when nr_pages > 1 |
f817ed48 | 2666 | * |
2f3479b1 KH |
2667 | * This function doesn't do "charge" to new cgroup and doesn't do "uncharge" |
2668 | * from old cgroup. | |
f817ed48 | 2669 | */ |
7ec99d62 JW |
2670 | static int mem_cgroup_move_account(struct page *page, |
2671 | unsigned int nr_pages, | |
2672 | struct page_cgroup *pc, | |
2673 | struct mem_cgroup *from, | |
2f3479b1 | 2674 | struct mem_cgroup *to) |
f817ed48 | 2675 | { |
de3638d9 JW |
2676 | unsigned long flags; |
2677 | int ret; | |
b2402857 | 2678 | bool anon = PageAnon(page); |
987eba66 | 2679 | |
f817ed48 | 2680 | VM_BUG_ON(from == to); |
5564e88b | 2681 | VM_BUG_ON(PageLRU(page)); |
de3638d9 JW |
2682 | /* |
2683 | * The page is isolated from LRU. So, collapse function | |
2684 | * will not handle this page. But page splitting can happen. | |
2685 | * Do this check under compound_page_lock(). The caller should | |
2686 | * hold it. | |
2687 | */ | |
2688 | ret = -EBUSY; | |
7ec99d62 | 2689 | if (nr_pages > 1 && !PageTransHuge(page)) |
de3638d9 JW |
2690 | goto out; |
2691 | ||
2692 | lock_page_cgroup(pc); | |
2693 | ||
2694 | ret = -EINVAL; | |
2695 | if (!PageCgroupUsed(pc) || pc->mem_cgroup != from) | |
2696 | goto unlock; | |
2697 | ||
312734c0 | 2698 | move_lock_mem_cgroup(from, &flags); |
f817ed48 | 2699 | |
2ff76f11 | 2700 | if (!anon && page_mapped(page)) { |
c62b1a3b KH |
2701 | /* Update mapped_file data for mem_cgroup */ |
2702 | preempt_disable(); | |
2703 | __this_cpu_dec(from->stat->count[MEM_CGROUP_STAT_FILE_MAPPED]); | |
2704 | __this_cpu_inc(to->stat->count[MEM_CGROUP_STAT_FILE_MAPPED]); | |
2705 | preempt_enable(); | |
d69b042f | 2706 | } |
b2402857 | 2707 | mem_cgroup_charge_statistics(from, anon, -nr_pages); |
d69b042f | 2708 | |
854ffa8d | 2709 | /* caller should have done css_get */ |
08e552c6 | 2710 | pc->mem_cgroup = to; |
b2402857 | 2711 | mem_cgroup_charge_statistics(to, anon, nr_pages); |
88703267 KH |
2712 | /* |
2713 | * We charges against "to" which may not have any tasks. Then, "to" | |
2714 | * can be under rmdir(). But in current implementation, caller of | |
4ffef5fe | 2715 | * this function is just force_empty() and move charge, so it's |
25985edc | 2716 | * guaranteed that "to" is never removed. So, we don't check rmdir |
4ffef5fe | 2717 | * status here. |
88703267 | 2718 | */ |
312734c0 | 2719 | move_unlock_mem_cgroup(from, &flags); |
de3638d9 JW |
2720 | ret = 0; |
2721 | unlock: | |
57f9fd7d | 2722 | unlock_page_cgroup(pc); |
d2265e6f KH |
2723 | /* |
2724 | * check events | |
2725 | */ | |
5564e88b JW |
2726 | memcg_check_events(to, page); |
2727 | memcg_check_events(from, page); | |
de3638d9 | 2728 | out: |
f817ed48 KH |
2729 | return ret; |
2730 | } | |
2731 | ||
2732 | /* | |
2733 | * move charges to its parent. | |
2734 | */ | |
2735 | ||
5564e88b JW |
2736 | static int mem_cgroup_move_parent(struct page *page, |
2737 | struct page_cgroup *pc, | |
6068bf01 | 2738 | struct mem_cgroup *child) |
f817ed48 | 2739 | { |
f817ed48 | 2740 | struct mem_cgroup *parent; |
7ec99d62 | 2741 | unsigned int nr_pages; |
4be4489f | 2742 | unsigned long uninitialized_var(flags); |
f817ed48 KH |
2743 | int ret; |
2744 | ||
2745 | /* Is ROOT ? */ | |
cc926f78 | 2746 | if (mem_cgroup_is_root(child)) |
f817ed48 KH |
2747 | return -EINVAL; |
2748 | ||
57f9fd7d DN |
2749 | ret = -EBUSY; |
2750 | if (!get_page_unless_zero(page)) | |
2751 | goto out; | |
2752 | if (isolate_lru_page(page)) | |
2753 | goto put; | |
52dbb905 | 2754 | |
7ec99d62 | 2755 | nr_pages = hpage_nr_pages(page); |
08e552c6 | 2756 | |
cc926f78 KH |
2757 | parent = parent_mem_cgroup(child); |
2758 | /* | |
2759 | * If no parent, move charges to root cgroup. | |
2760 | */ | |
2761 | if (!parent) | |
2762 | parent = root_mem_cgroup; | |
f817ed48 | 2763 | |
7ec99d62 | 2764 | if (nr_pages > 1) |
987eba66 KH |
2765 | flags = compound_lock_irqsave(page); |
2766 | ||
cc926f78 | 2767 | ret = mem_cgroup_move_account(page, nr_pages, |
2f3479b1 | 2768 | pc, child, parent); |
cc926f78 KH |
2769 | if (!ret) |
2770 | __mem_cgroup_cancel_local_charge(child, nr_pages); | |
8dba474f | 2771 | |
7ec99d62 | 2772 | if (nr_pages > 1) |
987eba66 | 2773 | compound_unlock_irqrestore(page, flags); |
08e552c6 | 2774 | putback_lru_page(page); |
57f9fd7d | 2775 | put: |
40d58138 | 2776 | put_page(page); |
57f9fd7d | 2777 | out: |
f817ed48 KH |
2778 | return ret; |
2779 | } | |
2780 | ||
7a81b88c KH |
2781 | /* |
2782 | * Charge the memory controller for page usage. | |
2783 | * Return | |
2784 | * 0 if the charge was successful | |
2785 | * < 0 if the cgroup is over its limit | |
2786 | */ | |
2787 | static int mem_cgroup_charge_common(struct page *page, struct mm_struct *mm, | |
73045c47 | 2788 | gfp_t gfp_mask, enum charge_type ctype) |
7a81b88c | 2789 | { |
c0ff4b85 | 2790 | struct mem_cgroup *memcg = NULL; |
7ec99d62 | 2791 | unsigned int nr_pages = 1; |
8493ae43 | 2792 | bool oom = true; |
7a81b88c | 2793 | int ret; |
ec168510 | 2794 | |
37c2ac78 | 2795 | if (PageTransHuge(page)) { |
7ec99d62 | 2796 | nr_pages <<= compound_order(page); |
37c2ac78 | 2797 | VM_BUG_ON(!PageTransHuge(page)); |
8493ae43 JW |
2798 | /* |
2799 | * Never OOM-kill a process for a huge page. The | |
2800 | * fault handler will fall back to regular pages. | |
2801 | */ | |
2802 | oom = false; | |
37c2ac78 | 2803 | } |
7a81b88c | 2804 | |
c0ff4b85 | 2805 | ret = __mem_cgroup_try_charge(mm, gfp_mask, nr_pages, &memcg, oom); |
38c5d72f | 2806 | if (ret == -ENOMEM) |
7a81b88c | 2807 | return ret; |
ce587e65 | 2808 | __mem_cgroup_commit_charge(memcg, page, nr_pages, ctype, false); |
8a9f3ccd | 2809 | return 0; |
8a9f3ccd BS |
2810 | } |
2811 | ||
7a81b88c KH |
2812 | int mem_cgroup_newpage_charge(struct page *page, |
2813 | struct mm_struct *mm, gfp_t gfp_mask) | |
217bc319 | 2814 | { |
f8d66542 | 2815 | if (mem_cgroup_disabled()) |
cede86ac | 2816 | return 0; |
7a0524cf JW |
2817 | VM_BUG_ON(page_mapped(page)); |
2818 | VM_BUG_ON(page->mapping && !PageAnon(page)); | |
2819 | VM_BUG_ON(!mm); | |
217bc319 | 2820 | return mem_cgroup_charge_common(page, mm, gfp_mask, |
41326c17 | 2821 | MEM_CGROUP_CHARGE_TYPE_ANON); |
217bc319 KH |
2822 | } |
2823 | ||
54595fe2 KH |
2824 | /* |
2825 | * While swap-in, try_charge -> commit or cancel, the page is locked. | |
2826 | * And when try_charge() successfully returns, one refcnt to memcg without | |
21ae2956 | 2827 | * struct page_cgroup is acquired. This refcnt will be consumed by |
54595fe2 KH |
2828 | * "commit()" or removed by "cancel()" |
2829 | */ | |
0435a2fd JW |
2830 | static int __mem_cgroup_try_charge_swapin(struct mm_struct *mm, |
2831 | struct page *page, | |
2832 | gfp_t mask, | |
2833 | struct mem_cgroup **memcgp) | |
8c7c6e34 | 2834 | { |
c0ff4b85 | 2835 | struct mem_cgroup *memcg; |
90deb788 | 2836 | struct page_cgroup *pc; |
54595fe2 | 2837 | int ret; |
8c7c6e34 | 2838 | |
90deb788 JW |
2839 | pc = lookup_page_cgroup(page); |
2840 | /* | |
2841 | * Every swap fault against a single page tries to charge the | |
2842 | * page, bail as early as possible. shmem_unuse() encounters | |
2843 | * already charged pages, too. The USED bit is protected by | |
2844 | * the page lock, which serializes swap cache removal, which | |
2845 | * in turn serializes uncharging. | |
2846 | */ | |
2847 | if (PageCgroupUsed(pc)) | |
2848 | return 0; | |
8c7c6e34 KH |
2849 | if (!do_swap_account) |
2850 | goto charge_cur_mm; | |
c0ff4b85 R |
2851 | memcg = try_get_mem_cgroup_from_page(page); |
2852 | if (!memcg) | |
54595fe2 | 2853 | goto charge_cur_mm; |
72835c86 JW |
2854 | *memcgp = memcg; |
2855 | ret = __mem_cgroup_try_charge(NULL, mask, 1, memcgp, true); | |
c0ff4b85 | 2856 | css_put(&memcg->css); |
38c5d72f KH |
2857 | if (ret == -EINTR) |
2858 | ret = 0; | |
54595fe2 | 2859 | return ret; |
8c7c6e34 | 2860 | charge_cur_mm: |
38c5d72f KH |
2861 | ret = __mem_cgroup_try_charge(mm, mask, 1, memcgp, true); |
2862 | if (ret == -EINTR) | |
2863 | ret = 0; | |
2864 | return ret; | |
8c7c6e34 KH |
2865 | } |
2866 | ||
0435a2fd JW |
2867 | int mem_cgroup_try_charge_swapin(struct mm_struct *mm, struct page *page, |
2868 | gfp_t gfp_mask, struct mem_cgroup **memcgp) | |
2869 | { | |
2870 | *memcgp = NULL; | |
2871 | if (mem_cgroup_disabled()) | |
2872 | return 0; | |
bdf4f4d2 JW |
2873 | /* |
2874 | * A racing thread's fault, or swapoff, may have already | |
2875 | * updated the pte, and even removed page from swap cache: in | |
2876 | * those cases unuse_pte()'s pte_same() test will fail; but | |
2877 | * there's also a KSM case which does need to charge the page. | |
2878 | */ | |
2879 | if (!PageSwapCache(page)) { | |
2880 | int ret; | |
2881 | ||
2882 | ret = __mem_cgroup_try_charge(mm, gfp_mask, 1, memcgp, true); | |
2883 | if (ret == -EINTR) | |
2884 | ret = 0; | |
2885 | return ret; | |
2886 | } | |
0435a2fd JW |
2887 | return __mem_cgroup_try_charge_swapin(mm, page, gfp_mask, memcgp); |
2888 | } | |
2889 | ||
827a03d2 JW |
2890 | void mem_cgroup_cancel_charge_swapin(struct mem_cgroup *memcg) |
2891 | { | |
2892 | if (mem_cgroup_disabled()) | |
2893 | return; | |
2894 | if (!memcg) | |
2895 | return; | |
2896 | __mem_cgroup_cancel_charge(memcg, 1); | |
2897 | } | |
2898 | ||
83aae4c7 | 2899 | static void |
72835c86 | 2900 | __mem_cgroup_commit_charge_swapin(struct page *page, struct mem_cgroup *memcg, |
83aae4c7 | 2901 | enum charge_type ctype) |
7a81b88c | 2902 | { |
f8d66542 | 2903 | if (mem_cgroup_disabled()) |
7a81b88c | 2904 | return; |
72835c86 | 2905 | if (!memcg) |
7a81b88c | 2906 | return; |
72835c86 | 2907 | cgroup_exclude_rmdir(&memcg->css); |
5a6475a4 | 2908 | |
ce587e65 | 2909 | __mem_cgroup_commit_charge(memcg, page, 1, ctype, true); |
8c7c6e34 KH |
2910 | /* |
2911 | * Now swap is on-memory. This means this page may be | |
2912 | * counted both as mem and swap....double count. | |
03f3c433 KH |
2913 | * Fix it by uncharging from memsw. Basically, this SwapCache is stable |
2914 | * under lock_page(). But in do_swap_page()::memory.c, reuse_swap_page() | |
2915 | * may call delete_from_swap_cache() before reach here. | |
8c7c6e34 | 2916 | */ |
03f3c433 | 2917 | if (do_swap_account && PageSwapCache(page)) { |
8c7c6e34 | 2918 | swp_entry_t ent = {.val = page_private(page)}; |
86493009 | 2919 | mem_cgroup_uncharge_swap(ent); |
8c7c6e34 | 2920 | } |
88703267 KH |
2921 | /* |
2922 | * At swapin, we may charge account against cgroup which has no tasks. | |
2923 | * So, rmdir()->pre_destroy() can be called while we do this charge. | |
2924 | * In that case, we need to call pre_destroy() again. check it here. | |
2925 | */ | |
72835c86 | 2926 | cgroup_release_and_wakeup_rmdir(&memcg->css); |
7a81b88c KH |
2927 | } |
2928 | ||
72835c86 JW |
2929 | void mem_cgroup_commit_charge_swapin(struct page *page, |
2930 | struct mem_cgroup *memcg) | |
83aae4c7 | 2931 | { |
72835c86 | 2932 | __mem_cgroup_commit_charge_swapin(page, memcg, |
41326c17 | 2933 | MEM_CGROUP_CHARGE_TYPE_ANON); |
83aae4c7 DN |
2934 | } |
2935 | ||
827a03d2 JW |
2936 | int mem_cgroup_cache_charge(struct page *page, struct mm_struct *mm, |
2937 | gfp_t gfp_mask) | |
7a81b88c | 2938 | { |
827a03d2 JW |
2939 | struct mem_cgroup *memcg = NULL; |
2940 | enum charge_type type = MEM_CGROUP_CHARGE_TYPE_CACHE; | |
2941 | int ret; | |
2942 | ||
f8d66542 | 2943 | if (mem_cgroup_disabled()) |
827a03d2 JW |
2944 | return 0; |
2945 | if (PageCompound(page)) | |
2946 | return 0; | |
2947 | ||
827a03d2 JW |
2948 | if (!PageSwapCache(page)) |
2949 | ret = mem_cgroup_charge_common(page, mm, gfp_mask, type); | |
2950 | else { /* page is swapcache/shmem */ | |
0435a2fd JW |
2951 | ret = __mem_cgroup_try_charge_swapin(mm, page, |
2952 | gfp_mask, &memcg); | |
827a03d2 JW |
2953 | if (!ret) |
2954 | __mem_cgroup_commit_charge_swapin(page, memcg, type); | |
2955 | } | |
2956 | return ret; | |
7a81b88c KH |
2957 | } |
2958 | ||
c0ff4b85 | 2959 | static void mem_cgroup_do_uncharge(struct mem_cgroup *memcg, |
7ec99d62 JW |
2960 | unsigned int nr_pages, |
2961 | const enum charge_type ctype) | |
569b846d KH |
2962 | { |
2963 | struct memcg_batch_info *batch = NULL; | |
2964 | bool uncharge_memsw = true; | |
7ec99d62 | 2965 | |
569b846d KH |
2966 | /* If swapout, usage of swap doesn't decrease */ |
2967 | if (!do_swap_account || ctype == MEM_CGROUP_CHARGE_TYPE_SWAPOUT) | |
2968 | uncharge_memsw = false; | |
569b846d KH |
2969 | |
2970 | batch = ¤t->memcg_batch; | |
2971 | /* | |
2972 | * In usual, we do css_get() when we remember memcg pointer. | |
2973 | * But in this case, we keep res->usage until end of a series of | |
2974 | * uncharges. Then, it's ok to ignore memcg's refcnt. | |
2975 | */ | |
2976 | if (!batch->memcg) | |
c0ff4b85 | 2977 | batch->memcg = memcg; |
3c11ecf4 KH |
2978 | /* |
2979 | * do_batch > 0 when unmapping pages or inode invalidate/truncate. | |
25985edc | 2980 | * In those cases, all pages freed continuously can be expected to be in |
3c11ecf4 KH |
2981 | * the same cgroup and we have chance to coalesce uncharges. |
2982 | * But we do uncharge one by one if this is killed by OOM(TIF_MEMDIE) | |
2983 | * because we want to do uncharge as soon as possible. | |
2984 | */ | |
2985 | ||
2986 | if (!batch->do_batch || test_thread_flag(TIF_MEMDIE)) | |
2987 | goto direct_uncharge; | |
2988 | ||
7ec99d62 | 2989 | if (nr_pages > 1) |
ec168510 AA |
2990 | goto direct_uncharge; |
2991 | ||
569b846d KH |
2992 | /* |
2993 | * In typical case, batch->memcg == mem. This means we can | |
2994 | * merge a series of uncharges to an uncharge of res_counter. | |
2995 | * If not, we uncharge res_counter ony by one. | |
2996 | */ | |
c0ff4b85 | 2997 | if (batch->memcg != memcg) |
569b846d KH |
2998 | goto direct_uncharge; |
2999 | /* remember freed charge and uncharge it later */ | |
7ffd4ca7 | 3000 | batch->nr_pages++; |
569b846d | 3001 | if (uncharge_memsw) |
7ffd4ca7 | 3002 | batch->memsw_nr_pages++; |
569b846d KH |
3003 | return; |
3004 | direct_uncharge: | |
c0ff4b85 | 3005 | res_counter_uncharge(&memcg->res, nr_pages * PAGE_SIZE); |
569b846d | 3006 | if (uncharge_memsw) |
c0ff4b85 R |
3007 | res_counter_uncharge(&memcg->memsw, nr_pages * PAGE_SIZE); |
3008 | if (unlikely(batch->memcg != memcg)) | |
3009 | memcg_oom_recover(memcg); | |
569b846d | 3010 | } |
7a81b88c | 3011 | |
8a9f3ccd | 3012 | /* |
69029cd5 | 3013 | * uncharge if !page_mapped(page) |
8a9f3ccd | 3014 | */ |
8c7c6e34 | 3015 | static struct mem_cgroup * |
0030f535 JW |
3016 | __mem_cgroup_uncharge_common(struct page *page, enum charge_type ctype, |
3017 | bool end_migration) | |
8a9f3ccd | 3018 | { |
c0ff4b85 | 3019 | struct mem_cgroup *memcg = NULL; |
7ec99d62 JW |
3020 | unsigned int nr_pages = 1; |
3021 | struct page_cgroup *pc; | |
b2402857 | 3022 | bool anon; |
8a9f3ccd | 3023 | |
f8d66542 | 3024 | if (mem_cgroup_disabled()) |
8c7c6e34 | 3025 | return NULL; |
4077960e | 3026 | |
0c59b89c | 3027 | VM_BUG_ON(PageSwapCache(page)); |
d13d1443 | 3028 | |
37c2ac78 | 3029 | if (PageTransHuge(page)) { |
7ec99d62 | 3030 | nr_pages <<= compound_order(page); |
37c2ac78 AA |
3031 | VM_BUG_ON(!PageTransHuge(page)); |
3032 | } | |
8697d331 | 3033 | /* |
3c541e14 | 3034 | * Check if our page_cgroup is valid |
8697d331 | 3035 | */ |
52d4b9ac | 3036 | pc = lookup_page_cgroup(page); |
cfa44946 | 3037 | if (unlikely(!PageCgroupUsed(pc))) |
8c7c6e34 | 3038 | return NULL; |
b9c565d5 | 3039 | |
52d4b9ac | 3040 | lock_page_cgroup(pc); |
d13d1443 | 3041 | |
c0ff4b85 | 3042 | memcg = pc->mem_cgroup; |
8c7c6e34 | 3043 | |
d13d1443 KH |
3044 | if (!PageCgroupUsed(pc)) |
3045 | goto unlock_out; | |
3046 | ||
b2402857 KH |
3047 | anon = PageAnon(page); |
3048 | ||
d13d1443 | 3049 | switch (ctype) { |
41326c17 | 3050 | case MEM_CGROUP_CHARGE_TYPE_ANON: |
2ff76f11 KH |
3051 | /* |
3052 | * Generally PageAnon tells if it's the anon statistics to be | |
3053 | * updated; but sometimes e.g. mem_cgroup_uncharge_page() is | |
3054 | * used before page reached the stage of being marked PageAnon. | |
3055 | */ | |
b2402857 KH |
3056 | anon = true; |
3057 | /* fallthrough */ | |
8a9478ca | 3058 | case MEM_CGROUP_CHARGE_TYPE_DROP: |
ac39cf8c | 3059 | /* See mem_cgroup_prepare_migration() */ |
0030f535 JW |
3060 | if (page_mapped(page)) |
3061 | goto unlock_out; | |
3062 | /* | |
3063 | * Pages under migration may not be uncharged. But | |
3064 | * end_migration() /must/ be the one uncharging the | |
3065 | * unused post-migration page and so it has to call | |
3066 | * here with the migration bit still set. See the | |
3067 | * res_counter handling below. | |
3068 | */ | |
3069 | if (!end_migration && PageCgroupMigration(pc)) | |
d13d1443 KH |
3070 | goto unlock_out; |
3071 | break; | |
3072 | case MEM_CGROUP_CHARGE_TYPE_SWAPOUT: | |
3073 | if (!PageAnon(page)) { /* Shared memory */ | |
3074 | if (page->mapping && !page_is_file_cache(page)) | |
3075 | goto unlock_out; | |
3076 | } else if (page_mapped(page)) /* Anon */ | |
3077 | goto unlock_out; | |
3078 | break; | |
3079 | default: | |
3080 | break; | |
52d4b9ac | 3081 | } |
d13d1443 | 3082 | |
b2402857 | 3083 | mem_cgroup_charge_statistics(memcg, anon, -nr_pages); |
04046e1a | 3084 | |
52d4b9ac | 3085 | ClearPageCgroupUsed(pc); |
544122e5 KH |
3086 | /* |
3087 | * pc->mem_cgroup is not cleared here. It will be accessed when it's | |
3088 | * freed from LRU. This is safe because uncharged page is expected not | |
3089 | * to be reused (freed soon). Exception is SwapCache, it's handled by | |
3090 | * special functions. | |
3091 | */ | |
b9c565d5 | 3092 | |
52d4b9ac | 3093 | unlock_page_cgroup(pc); |
f75ca962 | 3094 | /* |
c0ff4b85 | 3095 | * even after unlock, we have memcg->res.usage here and this memcg |
f75ca962 KH |
3096 | * will never be freed. |
3097 | */ | |
c0ff4b85 | 3098 | memcg_check_events(memcg, page); |
f75ca962 | 3099 | if (do_swap_account && ctype == MEM_CGROUP_CHARGE_TYPE_SWAPOUT) { |
c0ff4b85 R |
3100 | mem_cgroup_swap_statistics(memcg, true); |
3101 | mem_cgroup_get(memcg); | |
f75ca962 | 3102 | } |
0030f535 JW |
3103 | /* |
3104 | * Migration does not charge the res_counter for the | |
3105 | * replacement page, so leave it alone when phasing out the | |
3106 | * page that is unused after the migration. | |
3107 | */ | |
3108 | if (!end_migration && !mem_cgroup_is_root(memcg)) | |
c0ff4b85 | 3109 | mem_cgroup_do_uncharge(memcg, nr_pages, ctype); |
6d12e2d8 | 3110 | |
c0ff4b85 | 3111 | return memcg; |
d13d1443 KH |
3112 | |
3113 | unlock_out: | |
3114 | unlock_page_cgroup(pc); | |
8c7c6e34 | 3115 | return NULL; |
3c541e14 BS |
3116 | } |
3117 | ||
69029cd5 KH |
3118 | void mem_cgroup_uncharge_page(struct page *page) |
3119 | { | |
52d4b9ac KH |
3120 | /* early check. */ |
3121 | if (page_mapped(page)) | |
3122 | return; | |
40f23a21 | 3123 | VM_BUG_ON(page->mapping && !PageAnon(page)); |
0c59b89c JW |
3124 | if (PageSwapCache(page)) |
3125 | return; | |
0030f535 | 3126 | __mem_cgroup_uncharge_common(page, MEM_CGROUP_CHARGE_TYPE_ANON, false); |
69029cd5 KH |
3127 | } |
3128 | ||
3129 | void mem_cgroup_uncharge_cache_page(struct page *page) | |
3130 | { | |
3131 | VM_BUG_ON(page_mapped(page)); | |
b7abea96 | 3132 | VM_BUG_ON(page->mapping); |
0030f535 | 3133 | __mem_cgroup_uncharge_common(page, MEM_CGROUP_CHARGE_TYPE_CACHE, false); |
69029cd5 KH |
3134 | } |
3135 | ||
569b846d KH |
3136 | /* |
3137 | * Batch_start/batch_end is called in unmap_page_range/invlidate/trucate. | |
3138 | * In that cases, pages are freed continuously and we can expect pages | |
3139 | * are in the same memcg. All these calls itself limits the number of | |
3140 | * pages freed at once, then uncharge_start/end() is called properly. | |
3141 | * This may be called prural(2) times in a context, | |
3142 | */ | |
3143 | ||
3144 | void mem_cgroup_uncharge_start(void) | |
3145 | { | |
3146 | current->memcg_batch.do_batch++; | |
3147 | /* We can do nest. */ | |
3148 | if (current->memcg_batch.do_batch == 1) { | |
3149 | current->memcg_batch.memcg = NULL; | |
7ffd4ca7 JW |
3150 | current->memcg_batch.nr_pages = 0; |
3151 | current->memcg_batch.memsw_nr_pages = 0; | |
569b846d KH |
3152 | } |
3153 | } | |
3154 | ||
3155 | void mem_cgroup_uncharge_end(void) | |
3156 | { | |
3157 | struct memcg_batch_info *batch = ¤t->memcg_batch; | |
3158 | ||
3159 | if (!batch->do_batch) | |
3160 | return; | |
3161 | ||
3162 | batch->do_batch--; | |
3163 | if (batch->do_batch) /* If stacked, do nothing. */ | |
3164 | return; | |
3165 | ||
3166 | if (!batch->memcg) | |
3167 | return; | |
3168 | /* | |
3169 | * This "batch->memcg" is valid without any css_get/put etc... | |
3170 | * bacause we hide charges behind us. | |
3171 | */ | |
7ffd4ca7 JW |
3172 | if (batch->nr_pages) |
3173 | res_counter_uncharge(&batch->memcg->res, | |
3174 | batch->nr_pages * PAGE_SIZE); | |
3175 | if (batch->memsw_nr_pages) | |
3176 | res_counter_uncharge(&batch->memcg->memsw, | |
3177 | batch->memsw_nr_pages * PAGE_SIZE); | |
3c11ecf4 | 3178 | memcg_oom_recover(batch->memcg); |
569b846d KH |
3179 | /* forget this pointer (for sanity check) */ |
3180 | batch->memcg = NULL; | |
3181 | } | |
3182 | ||
e767e056 | 3183 | #ifdef CONFIG_SWAP |
8c7c6e34 | 3184 | /* |
e767e056 | 3185 | * called after __delete_from_swap_cache() and drop "page" account. |
8c7c6e34 KH |
3186 | * memcg information is recorded to swap_cgroup of "ent" |
3187 | */ | |
8a9478ca KH |
3188 | void |
3189 | mem_cgroup_uncharge_swapcache(struct page *page, swp_entry_t ent, bool swapout) | |
8c7c6e34 KH |
3190 | { |
3191 | struct mem_cgroup *memcg; | |
8a9478ca KH |
3192 | int ctype = MEM_CGROUP_CHARGE_TYPE_SWAPOUT; |
3193 | ||
3194 | if (!swapout) /* this was a swap cache but the swap is unused ! */ | |
3195 | ctype = MEM_CGROUP_CHARGE_TYPE_DROP; | |
3196 | ||
0030f535 | 3197 | memcg = __mem_cgroup_uncharge_common(page, ctype, false); |
8c7c6e34 | 3198 | |
f75ca962 KH |
3199 | /* |
3200 | * record memcg information, if swapout && memcg != NULL, | |
3201 | * mem_cgroup_get() was called in uncharge(). | |
3202 | */ | |
3203 | if (do_swap_account && swapout && memcg) | |
a3b2d692 | 3204 | swap_cgroup_record(ent, css_id(&memcg->css)); |
8c7c6e34 | 3205 | } |
e767e056 | 3206 | #endif |
8c7c6e34 | 3207 | |
c255a458 | 3208 | #ifdef CONFIG_MEMCG_SWAP |
8c7c6e34 KH |
3209 | /* |
3210 | * called from swap_entry_free(). remove record in swap_cgroup and | |
3211 | * uncharge "memsw" account. | |
3212 | */ | |
3213 | void mem_cgroup_uncharge_swap(swp_entry_t ent) | |
d13d1443 | 3214 | { |
8c7c6e34 | 3215 | struct mem_cgroup *memcg; |
a3b2d692 | 3216 | unsigned short id; |
8c7c6e34 KH |
3217 | |
3218 | if (!do_swap_account) | |
3219 | return; | |
3220 | ||
a3b2d692 KH |
3221 | id = swap_cgroup_record(ent, 0); |
3222 | rcu_read_lock(); | |
3223 | memcg = mem_cgroup_lookup(id); | |
8c7c6e34 | 3224 | if (memcg) { |
a3b2d692 KH |
3225 | /* |
3226 | * We uncharge this because swap is freed. | |
3227 | * This memcg can be obsolete one. We avoid calling css_tryget | |
3228 | */ | |
0c3e73e8 | 3229 | if (!mem_cgroup_is_root(memcg)) |
4e649152 | 3230 | res_counter_uncharge(&memcg->memsw, PAGE_SIZE); |
0c3e73e8 | 3231 | mem_cgroup_swap_statistics(memcg, false); |
8c7c6e34 KH |
3232 | mem_cgroup_put(memcg); |
3233 | } | |
a3b2d692 | 3234 | rcu_read_unlock(); |
d13d1443 | 3235 | } |
02491447 DN |
3236 | |
3237 | /** | |
3238 | * mem_cgroup_move_swap_account - move swap charge and swap_cgroup's record. | |
3239 | * @entry: swap entry to be moved | |
3240 | * @from: mem_cgroup which the entry is moved from | |
3241 | * @to: mem_cgroup which the entry is moved to | |
3242 | * | |
3243 | * It succeeds only when the swap_cgroup's record for this entry is the same | |
3244 | * as the mem_cgroup's id of @from. | |
3245 | * | |
3246 | * Returns 0 on success, -EINVAL on failure. | |
3247 | * | |
3248 | * The caller must have charged to @to, IOW, called res_counter_charge() about | |
3249 | * both res and memsw, and called css_get(). | |
3250 | */ | |
3251 | static int mem_cgroup_move_swap_account(swp_entry_t entry, | |
e91cbb42 | 3252 | struct mem_cgroup *from, struct mem_cgroup *to) |
02491447 DN |
3253 | { |
3254 | unsigned short old_id, new_id; | |
3255 | ||
3256 | old_id = css_id(&from->css); | |
3257 | new_id = css_id(&to->css); | |
3258 | ||
3259 | if (swap_cgroup_cmpxchg(entry, old_id, new_id) == old_id) { | |
02491447 | 3260 | mem_cgroup_swap_statistics(from, false); |
483c30b5 | 3261 | mem_cgroup_swap_statistics(to, true); |
02491447 | 3262 | /* |
483c30b5 DN |
3263 | * This function is only called from task migration context now. |
3264 | * It postpones res_counter and refcount handling till the end | |
3265 | * of task migration(mem_cgroup_clear_mc()) for performance | |
3266 | * improvement. But we cannot postpone mem_cgroup_get(to) | |
3267 | * because if the process that has been moved to @to does | |
3268 | * swap-in, the refcount of @to might be decreased to 0. | |
02491447 | 3269 | */ |
02491447 | 3270 | mem_cgroup_get(to); |
02491447 DN |
3271 | return 0; |
3272 | } | |
3273 | return -EINVAL; | |
3274 | } | |
3275 | #else | |
3276 | static inline int mem_cgroup_move_swap_account(swp_entry_t entry, | |
e91cbb42 | 3277 | struct mem_cgroup *from, struct mem_cgroup *to) |
02491447 DN |
3278 | { |
3279 | return -EINVAL; | |
3280 | } | |
8c7c6e34 | 3281 | #endif |
d13d1443 | 3282 | |
ae41be37 | 3283 | /* |
01b1ae63 KH |
3284 | * Before starting migration, account PAGE_SIZE to mem_cgroup that the old |
3285 | * page belongs to. | |
ae41be37 | 3286 | */ |
0030f535 JW |
3287 | void mem_cgroup_prepare_migration(struct page *page, struct page *newpage, |
3288 | struct mem_cgroup **memcgp) | |
ae41be37 | 3289 | { |
c0ff4b85 | 3290 | struct mem_cgroup *memcg = NULL; |
7ec99d62 | 3291 | struct page_cgroup *pc; |
ac39cf8c | 3292 | enum charge_type ctype; |
8869b8f6 | 3293 | |
72835c86 | 3294 | *memcgp = NULL; |
56039efa | 3295 | |
ec168510 | 3296 | VM_BUG_ON(PageTransHuge(page)); |
f8d66542 | 3297 | if (mem_cgroup_disabled()) |
0030f535 | 3298 | return; |
4077960e | 3299 | |
52d4b9ac KH |
3300 | pc = lookup_page_cgroup(page); |
3301 | lock_page_cgroup(pc); | |
3302 | if (PageCgroupUsed(pc)) { | |
c0ff4b85 R |
3303 | memcg = pc->mem_cgroup; |
3304 | css_get(&memcg->css); | |
ac39cf8c AM |
3305 | /* |
3306 | * At migrating an anonymous page, its mapcount goes down | |
3307 | * to 0 and uncharge() will be called. But, even if it's fully | |
3308 | * unmapped, migration may fail and this page has to be | |
3309 | * charged again. We set MIGRATION flag here and delay uncharge | |
3310 | * until end_migration() is called | |
3311 | * | |
3312 | * Corner Case Thinking | |
3313 | * A) | |
3314 | * When the old page was mapped as Anon and it's unmap-and-freed | |
3315 | * while migration was ongoing. | |
3316 | * If unmap finds the old page, uncharge() of it will be delayed | |
3317 | * until end_migration(). If unmap finds a new page, it's | |
3318 | * uncharged when it make mapcount to be 1->0. If unmap code | |
3319 | * finds swap_migration_entry, the new page will not be mapped | |
3320 | * and end_migration() will find it(mapcount==0). | |
3321 | * | |
3322 | * B) | |
3323 | * When the old page was mapped but migraion fails, the kernel | |
3324 | * remaps it. A charge for it is kept by MIGRATION flag even | |
3325 | * if mapcount goes down to 0. We can do remap successfully | |
3326 | * without charging it again. | |
3327 | * | |
3328 | * C) | |
3329 | * The "old" page is under lock_page() until the end of | |
3330 | * migration, so, the old page itself will not be swapped-out. | |
3331 | * If the new page is swapped out before end_migraton, our | |
3332 | * hook to usual swap-out path will catch the event. | |
3333 | */ | |
3334 | if (PageAnon(page)) | |
3335 | SetPageCgroupMigration(pc); | |
e8589cc1 | 3336 | } |
52d4b9ac | 3337 | unlock_page_cgroup(pc); |
ac39cf8c AM |
3338 | /* |
3339 | * If the page is not charged at this point, | |
3340 | * we return here. | |
3341 | */ | |
c0ff4b85 | 3342 | if (!memcg) |
0030f535 | 3343 | return; |
01b1ae63 | 3344 | |
72835c86 | 3345 | *memcgp = memcg; |
ac39cf8c AM |
3346 | /* |
3347 | * We charge new page before it's used/mapped. So, even if unlock_page() | |
3348 | * is called before end_migration, we can catch all events on this new | |
3349 | * page. In the case new page is migrated but not remapped, new page's | |
3350 | * mapcount will be finally 0 and we call uncharge in end_migration(). | |
3351 | */ | |
ac39cf8c | 3352 | if (PageAnon(page)) |
41326c17 | 3353 | ctype = MEM_CGROUP_CHARGE_TYPE_ANON; |
ac39cf8c | 3354 | else |
62ba7442 | 3355 | ctype = MEM_CGROUP_CHARGE_TYPE_CACHE; |
0030f535 JW |
3356 | /* |
3357 | * The page is committed to the memcg, but it's not actually | |
3358 | * charged to the res_counter since we plan on replacing the | |
3359 | * old one and only one page is going to be left afterwards. | |
3360 | */ | |
ce587e65 | 3361 | __mem_cgroup_commit_charge(memcg, newpage, 1, ctype, false); |
ae41be37 | 3362 | } |
8869b8f6 | 3363 | |
69029cd5 | 3364 | /* remove redundant charge if migration failed*/ |
c0ff4b85 | 3365 | void mem_cgroup_end_migration(struct mem_cgroup *memcg, |
50de1dd9 | 3366 | struct page *oldpage, struct page *newpage, bool migration_ok) |
ae41be37 | 3367 | { |
ac39cf8c | 3368 | struct page *used, *unused; |
01b1ae63 | 3369 | struct page_cgroup *pc; |
b2402857 | 3370 | bool anon; |
01b1ae63 | 3371 | |
c0ff4b85 | 3372 | if (!memcg) |
01b1ae63 | 3373 | return; |
ac39cf8c | 3374 | /* blocks rmdir() */ |
c0ff4b85 | 3375 | cgroup_exclude_rmdir(&memcg->css); |
50de1dd9 | 3376 | if (!migration_ok) { |
ac39cf8c AM |
3377 | used = oldpage; |
3378 | unused = newpage; | |
01b1ae63 | 3379 | } else { |
ac39cf8c | 3380 | used = newpage; |
01b1ae63 KH |
3381 | unused = oldpage; |
3382 | } | |
0030f535 | 3383 | anon = PageAnon(used); |
7d188958 JW |
3384 | __mem_cgroup_uncharge_common(unused, |
3385 | anon ? MEM_CGROUP_CHARGE_TYPE_ANON | |
3386 | : MEM_CGROUP_CHARGE_TYPE_CACHE, | |
3387 | true); | |
0030f535 | 3388 | css_put(&memcg->css); |
69029cd5 | 3389 | /* |
ac39cf8c AM |
3390 | * We disallowed uncharge of pages under migration because mapcount |
3391 | * of the page goes down to zero, temporarly. | |
3392 | * Clear the flag and check the page should be charged. | |
01b1ae63 | 3393 | */ |
ac39cf8c AM |
3394 | pc = lookup_page_cgroup(oldpage); |
3395 | lock_page_cgroup(pc); | |
3396 | ClearPageCgroupMigration(pc); | |
3397 | unlock_page_cgroup(pc); | |
ac39cf8c | 3398 | |
01b1ae63 | 3399 | /* |
ac39cf8c AM |
3400 | * If a page is a file cache, radix-tree replacement is very atomic |
3401 | * and we can skip this check. When it was an Anon page, its mapcount | |
3402 | * goes down to 0. But because we added MIGRATION flage, it's not | |
3403 | * uncharged yet. There are several case but page->mapcount check | |
3404 | * and USED bit check in mem_cgroup_uncharge_page() will do enough | |
3405 | * check. (see prepare_charge() also) | |
69029cd5 | 3406 | */ |
b2402857 | 3407 | if (anon) |
ac39cf8c | 3408 | mem_cgroup_uncharge_page(used); |
88703267 | 3409 | /* |
ac39cf8c AM |
3410 | * At migration, we may charge account against cgroup which has no |
3411 | * tasks. | |
88703267 KH |
3412 | * So, rmdir()->pre_destroy() can be called while we do this charge. |
3413 | * In that case, we need to call pre_destroy() again. check it here. | |
3414 | */ | |
c0ff4b85 | 3415 | cgroup_release_and_wakeup_rmdir(&memcg->css); |
ae41be37 | 3416 | } |
78fb7466 | 3417 | |
ab936cbc KH |
3418 | /* |
3419 | * At replace page cache, newpage is not under any memcg but it's on | |
3420 | * LRU. So, this function doesn't touch res_counter but handles LRU | |
3421 | * in correct way. Both pages are locked so we cannot race with uncharge. | |
3422 | */ | |
3423 | void mem_cgroup_replace_page_cache(struct page *oldpage, | |
3424 | struct page *newpage) | |
3425 | { | |
bde05d1c | 3426 | struct mem_cgroup *memcg = NULL; |
ab936cbc | 3427 | struct page_cgroup *pc; |
ab936cbc | 3428 | enum charge_type type = MEM_CGROUP_CHARGE_TYPE_CACHE; |
ab936cbc KH |
3429 | |
3430 | if (mem_cgroup_disabled()) | |
3431 | return; | |
3432 | ||
3433 | pc = lookup_page_cgroup(oldpage); | |
3434 | /* fix accounting on old pages */ | |
3435 | lock_page_cgroup(pc); | |
bde05d1c HD |
3436 | if (PageCgroupUsed(pc)) { |
3437 | memcg = pc->mem_cgroup; | |
3438 | mem_cgroup_charge_statistics(memcg, false, -1); | |
3439 | ClearPageCgroupUsed(pc); | |
3440 | } | |
ab936cbc KH |
3441 | unlock_page_cgroup(pc); |
3442 | ||
bde05d1c HD |
3443 | /* |
3444 | * When called from shmem_replace_page(), in some cases the | |
3445 | * oldpage has already been charged, and in some cases not. | |
3446 | */ | |
3447 | if (!memcg) | |
3448 | return; | |
ab936cbc KH |
3449 | /* |
3450 | * Even if newpage->mapping was NULL before starting replacement, | |
3451 | * the newpage may be on LRU(or pagevec for LRU) already. We lock | |
3452 | * LRU while we overwrite pc->mem_cgroup. | |
3453 | */ | |
ce587e65 | 3454 | __mem_cgroup_commit_charge(memcg, newpage, 1, type, true); |
ab936cbc KH |
3455 | } |
3456 | ||
f212ad7c DN |
3457 | #ifdef CONFIG_DEBUG_VM |
3458 | static struct page_cgroup *lookup_page_cgroup_used(struct page *page) | |
3459 | { | |
3460 | struct page_cgroup *pc; | |
3461 | ||
3462 | pc = lookup_page_cgroup(page); | |
cfa44946 JW |
3463 | /* |
3464 | * Can be NULL while feeding pages into the page allocator for | |
3465 | * the first time, i.e. during boot or memory hotplug; | |
3466 | * or when mem_cgroup_disabled(). | |
3467 | */ | |
f212ad7c DN |
3468 | if (likely(pc) && PageCgroupUsed(pc)) |
3469 | return pc; | |
3470 | return NULL; | |
3471 | } | |
3472 | ||
3473 | bool mem_cgroup_bad_page_check(struct page *page) | |
3474 | { | |
3475 | if (mem_cgroup_disabled()) | |
3476 | return false; | |
3477 | ||
3478 | return lookup_page_cgroup_used(page) != NULL; | |
3479 | } | |
3480 | ||
3481 | void mem_cgroup_print_bad_page(struct page *page) | |
3482 | { | |
3483 | struct page_cgroup *pc; | |
3484 | ||
3485 | pc = lookup_page_cgroup_used(page); | |
3486 | if (pc) { | |
90b3feae | 3487 | printk(KERN_ALERT "pc:%p pc->flags:%lx pc->mem_cgroup:%p\n", |
f212ad7c | 3488 | pc, pc->flags, pc->mem_cgroup); |
f212ad7c DN |
3489 | } |
3490 | } | |
3491 | #endif | |
3492 | ||
8c7c6e34 KH |
3493 | static DEFINE_MUTEX(set_limit_mutex); |
3494 | ||
d38d2a75 | 3495 | static int mem_cgroup_resize_limit(struct mem_cgroup *memcg, |
8c7c6e34 | 3496 | unsigned long long val) |
628f4235 | 3497 | { |
81d39c20 | 3498 | int retry_count; |
3c11ecf4 | 3499 | u64 memswlimit, memlimit; |
628f4235 | 3500 | int ret = 0; |
81d39c20 KH |
3501 | int children = mem_cgroup_count_children(memcg); |
3502 | u64 curusage, oldusage; | |
3c11ecf4 | 3503 | int enlarge; |
81d39c20 KH |
3504 | |
3505 | /* | |
3506 | * For keeping hierarchical_reclaim simple, how long we should retry | |
3507 | * is depends on callers. We set our retry-count to be function | |
3508 | * of # of children which we should visit in this loop. | |
3509 | */ | |
3510 | retry_count = MEM_CGROUP_RECLAIM_RETRIES * children; | |
3511 | ||
3512 | oldusage = res_counter_read_u64(&memcg->res, RES_USAGE); | |
628f4235 | 3513 | |
3c11ecf4 | 3514 | enlarge = 0; |
8c7c6e34 | 3515 | while (retry_count) { |
628f4235 KH |
3516 | if (signal_pending(current)) { |
3517 | ret = -EINTR; | |
3518 | break; | |
3519 | } | |
8c7c6e34 KH |
3520 | /* |
3521 | * Rather than hide all in some function, I do this in | |
3522 | * open coded manner. You see what this really does. | |
aaad153e | 3523 | * We have to guarantee memcg->res.limit <= memcg->memsw.limit. |
8c7c6e34 KH |
3524 | */ |
3525 | mutex_lock(&set_limit_mutex); | |
3526 | memswlimit = res_counter_read_u64(&memcg->memsw, RES_LIMIT); | |
3527 | if (memswlimit < val) { | |
3528 | ret = -EINVAL; | |
3529 | mutex_unlock(&set_limit_mutex); | |
628f4235 KH |
3530 | break; |
3531 | } | |
3c11ecf4 KH |
3532 | |
3533 | memlimit = res_counter_read_u64(&memcg->res, RES_LIMIT); | |
3534 | if (memlimit < val) | |
3535 | enlarge = 1; | |
3536 | ||
8c7c6e34 | 3537 | ret = res_counter_set_limit(&memcg->res, val); |
22a668d7 KH |
3538 | if (!ret) { |
3539 | if (memswlimit == val) | |
3540 | memcg->memsw_is_minimum = true; | |
3541 | else | |
3542 | memcg->memsw_is_minimum = false; | |
3543 | } | |
8c7c6e34 KH |
3544 | mutex_unlock(&set_limit_mutex); |
3545 | ||
3546 | if (!ret) | |
3547 | break; | |
3548 | ||
5660048c JW |
3549 | mem_cgroup_reclaim(memcg, GFP_KERNEL, |
3550 | MEM_CGROUP_RECLAIM_SHRINK); | |
81d39c20 KH |
3551 | curusage = res_counter_read_u64(&memcg->res, RES_USAGE); |
3552 | /* Usage is reduced ? */ | |
3553 | if (curusage >= oldusage) | |
3554 | retry_count--; | |
3555 | else | |
3556 | oldusage = curusage; | |
8c7c6e34 | 3557 | } |
3c11ecf4 KH |
3558 | if (!ret && enlarge) |
3559 | memcg_oom_recover(memcg); | |
14797e23 | 3560 | |
8c7c6e34 KH |
3561 | return ret; |
3562 | } | |
3563 | ||
338c8431 LZ |
3564 | static int mem_cgroup_resize_memsw_limit(struct mem_cgroup *memcg, |
3565 | unsigned long long val) | |
8c7c6e34 | 3566 | { |
81d39c20 | 3567 | int retry_count; |
3c11ecf4 | 3568 | u64 memlimit, memswlimit, oldusage, curusage; |
81d39c20 KH |
3569 | int children = mem_cgroup_count_children(memcg); |
3570 | int ret = -EBUSY; | |
3c11ecf4 | 3571 | int enlarge = 0; |
8c7c6e34 | 3572 | |
81d39c20 KH |
3573 | /* see mem_cgroup_resize_res_limit */ |
3574 | retry_count = children * MEM_CGROUP_RECLAIM_RETRIES; | |
3575 | oldusage = res_counter_read_u64(&memcg->memsw, RES_USAGE); | |
8c7c6e34 KH |
3576 | while (retry_count) { |
3577 | if (signal_pending(current)) { | |
3578 | ret = -EINTR; | |
3579 | break; | |
3580 | } | |
3581 | /* | |
3582 | * Rather than hide all in some function, I do this in | |
3583 | * open coded manner. You see what this really does. | |
aaad153e | 3584 | * We have to guarantee memcg->res.limit <= memcg->memsw.limit. |
8c7c6e34 KH |
3585 | */ |
3586 | mutex_lock(&set_limit_mutex); | |
3587 | memlimit = res_counter_read_u64(&memcg->res, RES_LIMIT); | |
3588 | if (memlimit > val) { | |
3589 | ret = -EINVAL; | |
3590 | mutex_unlock(&set_limit_mutex); | |
3591 | break; | |
3592 | } | |
3c11ecf4 KH |
3593 | memswlimit = res_counter_read_u64(&memcg->memsw, RES_LIMIT); |
3594 | if (memswlimit < val) | |
3595 | enlarge = 1; | |
8c7c6e34 | 3596 | ret = res_counter_set_limit(&memcg->memsw, val); |
22a668d7 KH |
3597 | if (!ret) { |
3598 | if (memlimit == val) | |
3599 | memcg->memsw_is_minimum = true; | |
3600 | else | |
3601 | memcg->memsw_is_minimum = false; | |
3602 | } | |
8c7c6e34 KH |
3603 | mutex_unlock(&set_limit_mutex); |
3604 | ||
3605 | if (!ret) | |
3606 | break; | |
3607 | ||
5660048c JW |
3608 | mem_cgroup_reclaim(memcg, GFP_KERNEL, |
3609 | MEM_CGROUP_RECLAIM_NOSWAP | | |
3610 | MEM_CGROUP_RECLAIM_SHRINK); | |
8c7c6e34 | 3611 | curusage = res_counter_read_u64(&memcg->memsw, RES_USAGE); |
81d39c20 | 3612 | /* Usage is reduced ? */ |
8c7c6e34 | 3613 | if (curusage >= oldusage) |
628f4235 | 3614 | retry_count--; |
81d39c20 KH |
3615 | else |
3616 | oldusage = curusage; | |
628f4235 | 3617 | } |
3c11ecf4 KH |
3618 | if (!ret && enlarge) |
3619 | memcg_oom_recover(memcg); | |
628f4235 KH |
3620 | return ret; |
3621 | } | |
3622 | ||
4e416953 | 3623 | unsigned long mem_cgroup_soft_limit_reclaim(struct zone *zone, int order, |
0ae5e89c YH |
3624 | gfp_t gfp_mask, |
3625 | unsigned long *total_scanned) | |
4e416953 BS |
3626 | { |
3627 | unsigned long nr_reclaimed = 0; | |
3628 | struct mem_cgroup_per_zone *mz, *next_mz = NULL; | |
3629 | unsigned long reclaimed; | |
3630 | int loop = 0; | |
3631 | struct mem_cgroup_tree_per_zone *mctz; | |
ef8745c1 | 3632 | unsigned long long excess; |
0ae5e89c | 3633 | unsigned long nr_scanned; |
4e416953 BS |
3634 | |
3635 | if (order > 0) | |
3636 | return 0; | |
3637 | ||
00918b6a | 3638 | mctz = soft_limit_tree_node_zone(zone_to_nid(zone), zone_idx(zone)); |
4e416953 BS |
3639 | /* |
3640 | * This loop can run a while, specially if mem_cgroup's continuously | |
3641 | * keep exceeding their soft limit and putting the system under | |
3642 | * pressure | |
3643 | */ | |
3644 | do { | |
3645 | if (next_mz) | |
3646 | mz = next_mz; | |
3647 | else | |
3648 | mz = mem_cgroup_largest_soft_limit_node(mctz); | |
3649 | if (!mz) | |
3650 | break; | |
3651 | ||
0ae5e89c | 3652 | nr_scanned = 0; |
d79154bb | 3653 | reclaimed = mem_cgroup_soft_reclaim(mz->memcg, zone, |
5660048c | 3654 | gfp_mask, &nr_scanned); |
4e416953 | 3655 | nr_reclaimed += reclaimed; |
0ae5e89c | 3656 | *total_scanned += nr_scanned; |
4e416953 BS |
3657 | spin_lock(&mctz->lock); |
3658 | ||
3659 | /* | |
3660 | * If we failed to reclaim anything from this memory cgroup | |
3661 | * it is time to move on to the next cgroup | |
3662 | */ | |
3663 | next_mz = NULL; | |
3664 | if (!reclaimed) { | |
3665 | do { | |
3666 | /* | |
3667 | * Loop until we find yet another one. | |
3668 | * | |
3669 | * By the time we get the soft_limit lock | |
3670 | * again, someone might have aded the | |
3671 | * group back on the RB tree. Iterate to | |
3672 | * make sure we get a different mem. | |
3673 | * mem_cgroup_largest_soft_limit_node returns | |
3674 | * NULL if no other cgroup is present on | |
3675 | * the tree | |
3676 | */ | |
3677 | next_mz = | |
3678 | __mem_cgroup_largest_soft_limit_node(mctz); | |
39cc98f1 | 3679 | if (next_mz == mz) |
d79154bb | 3680 | css_put(&next_mz->memcg->css); |
39cc98f1 | 3681 | else /* next_mz == NULL or other memcg */ |
4e416953 BS |
3682 | break; |
3683 | } while (1); | |
3684 | } | |
d79154bb HD |
3685 | __mem_cgroup_remove_exceeded(mz->memcg, mz, mctz); |
3686 | excess = res_counter_soft_limit_excess(&mz->memcg->res); | |
4e416953 BS |
3687 | /* |
3688 | * One school of thought says that we should not add | |
3689 | * back the node to the tree if reclaim returns 0. | |
3690 | * But our reclaim could return 0, simply because due | |
3691 | * to priority we are exposing a smaller subset of | |
3692 | * memory to reclaim from. Consider this as a longer | |
3693 | * term TODO. | |
3694 | */ | |
ef8745c1 | 3695 | /* If excess == 0, no tree ops */ |
d79154bb | 3696 | __mem_cgroup_insert_exceeded(mz->memcg, mz, mctz, excess); |
4e416953 | 3697 | spin_unlock(&mctz->lock); |
d79154bb | 3698 | css_put(&mz->memcg->css); |
4e416953 BS |
3699 | loop++; |
3700 | /* | |
3701 | * Could not reclaim anything and there are no more | |
3702 | * mem cgroups to try or we seem to be looping without | |
3703 | * reclaiming anything. | |
3704 | */ | |
3705 | if (!nr_reclaimed && | |
3706 | (next_mz == NULL || | |
3707 | loop > MEM_CGROUP_MAX_SOFT_LIMIT_RECLAIM_LOOPS)) | |
3708 | break; | |
3709 | } while (!nr_reclaimed); | |
3710 | if (next_mz) | |
d79154bb | 3711 | css_put(&next_mz->memcg->css); |
4e416953 BS |
3712 | return nr_reclaimed; |
3713 | } | |
3714 | ||
cc847582 | 3715 | /* |
3c935d18 KH |
3716 | * Traverse a specified page_cgroup list and try to drop them all. This doesn't |
3717 | * reclaim the pages page themselves - it just removes the page_cgroups. | |
3718 | * Returns true if some page_cgroups were not freed, indicating that the caller | |
3719 | * must retry this operation. | |
cc847582 | 3720 | */ |
3c935d18 | 3721 | static bool mem_cgroup_force_empty_list(struct mem_cgroup *memcg, |
08e552c6 | 3722 | int node, int zid, enum lru_list lru) |
cc847582 | 3723 | { |
bea8c150 | 3724 | struct lruvec *lruvec; |
08e552c6 | 3725 | unsigned long flags, loop; |
072c56c1 | 3726 | struct list_head *list; |
925b7673 JW |
3727 | struct page *busy; |
3728 | struct zone *zone; | |
072c56c1 | 3729 | |
08e552c6 | 3730 | zone = &NODE_DATA(node)->node_zones[zid]; |
bea8c150 HD |
3731 | lruvec = mem_cgroup_zone_lruvec(zone, memcg); |
3732 | list = &lruvec->lists[lru]; | |
cc847582 | 3733 | |
bea8c150 | 3734 | loop = mem_cgroup_get_lru_size(lruvec, lru); |
f817ed48 KH |
3735 | /* give some margin against EBUSY etc...*/ |
3736 | loop += 256; | |
3737 | busy = NULL; | |
3738 | while (loop--) { | |
925b7673 | 3739 | struct page_cgroup *pc; |
5564e88b JW |
3740 | struct page *page; |
3741 | ||
08e552c6 | 3742 | spin_lock_irqsave(&zone->lru_lock, flags); |
f817ed48 | 3743 | if (list_empty(list)) { |
08e552c6 | 3744 | spin_unlock_irqrestore(&zone->lru_lock, flags); |
52d4b9ac | 3745 | break; |
f817ed48 | 3746 | } |
925b7673 JW |
3747 | page = list_entry(list->prev, struct page, lru); |
3748 | if (busy == page) { | |
3749 | list_move(&page->lru, list); | |
648bcc77 | 3750 | busy = NULL; |
08e552c6 | 3751 | spin_unlock_irqrestore(&zone->lru_lock, flags); |
f817ed48 KH |
3752 | continue; |
3753 | } | |
08e552c6 | 3754 | spin_unlock_irqrestore(&zone->lru_lock, flags); |
f817ed48 | 3755 | |
925b7673 | 3756 | pc = lookup_page_cgroup(page); |
5564e88b | 3757 | |
3c935d18 | 3758 | if (mem_cgroup_move_parent(page, pc, memcg)) { |
f817ed48 | 3759 | /* found lock contention or "pc" is obsolete. */ |
925b7673 | 3760 | busy = page; |
f817ed48 KH |
3761 | cond_resched(); |
3762 | } else | |
3763 | busy = NULL; | |
cc847582 | 3764 | } |
3c935d18 | 3765 | return !list_empty(list); |
cc847582 KH |
3766 | } |
3767 | ||
3768 | /* | |
3769 | * make mem_cgroup's charge to be 0 if there is no task. | |
3770 | * This enables deleting this mem_cgroup. | |
3771 | */ | |
c0ff4b85 | 3772 | static int mem_cgroup_force_empty(struct mem_cgroup *memcg, bool free_all) |
cc847582 | 3773 | { |
f817ed48 KH |
3774 | int ret; |
3775 | int node, zid, shrink; | |
3776 | int nr_retries = MEM_CGROUP_RECLAIM_RETRIES; | |
c0ff4b85 | 3777 | struct cgroup *cgrp = memcg->css.cgroup; |
8869b8f6 | 3778 | |
c0ff4b85 | 3779 | css_get(&memcg->css); |
f817ed48 KH |
3780 | |
3781 | shrink = 0; | |
c1e862c1 KH |
3782 | /* should free all ? */ |
3783 | if (free_all) | |
3784 | goto try_to_free; | |
f817ed48 | 3785 | move_account: |
fce66477 | 3786 | do { |
f817ed48 | 3787 | ret = -EBUSY; |
c1e862c1 KH |
3788 | if (cgroup_task_count(cgrp) || !list_empty(&cgrp->children)) |
3789 | goto out; | |
52d4b9ac KH |
3790 | /* This is for making all *used* pages to be on LRU. */ |
3791 | lru_add_drain_all(); | |
c0ff4b85 | 3792 | drain_all_stock_sync(memcg); |
f817ed48 | 3793 | ret = 0; |
c0ff4b85 | 3794 | mem_cgroup_start_move(memcg); |
299b4eaa | 3795 | for_each_node_state(node, N_HIGH_MEMORY) { |
f817ed48 | 3796 | for (zid = 0; !ret && zid < MAX_NR_ZONES; zid++) { |
f156ab93 HD |
3797 | enum lru_list lru; |
3798 | for_each_lru(lru) { | |
c0ff4b85 | 3799 | ret = mem_cgroup_force_empty_list(memcg, |
f156ab93 | 3800 | node, zid, lru); |
f817ed48 KH |
3801 | if (ret) |
3802 | break; | |
3803 | } | |
1ecaab2b | 3804 | } |
f817ed48 KH |
3805 | if (ret) |
3806 | break; | |
3807 | } | |
c0ff4b85 R |
3808 | mem_cgroup_end_move(memcg); |
3809 | memcg_oom_recover(memcg); | |
52d4b9ac | 3810 | cond_resched(); |
fce66477 | 3811 | /* "ret" should also be checked to ensure all lists are empty. */ |
569530fb | 3812 | } while (res_counter_read_u64(&memcg->res, RES_USAGE) > 0 || ret); |
cc847582 | 3813 | out: |
c0ff4b85 | 3814 | css_put(&memcg->css); |
cc847582 | 3815 | return ret; |
f817ed48 KH |
3816 | |
3817 | try_to_free: | |
c1e862c1 KH |
3818 | /* returns EBUSY if there is a task or if we come here twice. */ |
3819 | if (cgroup_task_count(cgrp) || !list_empty(&cgrp->children) || shrink) { | |
f817ed48 KH |
3820 | ret = -EBUSY; |
3821 | goto out; | |
3822 | } | |
c1e862c1 KH |
3823 | /* we call try-to-free pages for make this cgroup empty */ |
3824 | lru_add_drain_all(); | |
f817ed48 KH |
3825 | /* try to free all pages in this cgroup */ |
3826 | shrink = 1; | |
569530fb | 3827 | while (nr_retries && res_counter_read_u64(&memcg->res, RES_USAGE) > 0) { |
f817ed48 | 3828 | int progress; |
c1e862c1 KH |
3829 | |
3830 | if (signal_pending(current)) { | |
3831 | ret = -EINTR; | |
3832 | goto out; | |
3833 | } | |
c0ff4b85 | 3834 | progress = try_to_free_mem_cgroup_pages(memcg, GFP_KERNEL, |
185efc0f | 3835 | false); |
c1e862c1 | 3836 | if (!progress) { |
f817ed48 | 3837 | nr_retries--; |
c1e862c1 | 3838 | /* maybe some writeback is necessary */ |
8aa7e847 | 3839 | congestion_wait(BLK_RW_ASYNC, HZ/10); |
c1e862c1 | 3840 | } |
f817ed48 KH |
3841 | |
3842 | } | |
08e552c6 | 3843 | lru_add_drain(); |
f817ed48 | 3844 | /* try move_account...there may be some *locked* pages. */ |
fce66477 | 3845 | goto move_account; |
cc847582 KH |
3846 | } |
3847 | ||
6bbda35c | 3848 | static int mem_cgroup_force_empty_write(struct cgroup *cont, unsigned int event) |
c1e862c1 KH |
3849 | { |
3850 | return mem_cgroup_force_empty(mem_cgroup_from_cont(cont), true); | |
3851 | } | |
3852 | ||
3853 | ||
18f59ea7 BS |
3854 | static u64 mem_cgroup_hierarchy_read(struct cgroup *cont, struct cftype *cft) |
3855 | { | |
3856 | return mem_cgroup_from_cont(cont)->use_hierarchy; | |
3857 | } | |
3858 | ||
3859 | static int mem_cgroup_hierarchy_write(struct cgroup *cont, struct cftype *cft, | |
3860 | u64 val) | |
3861 | { | |
3862 | int retval = 0; | |
c0ff4b85 | 3863 | struct mem_cgroup *memcg = mem_cgroup_from_cont(cont); |
18f59ea7 | 3864 | struct cgroup *parent = cont->parent; |
c0ff4b85 | 3865 | struct mem_cgroup *parent_memcg = NULL; |
18f59ea7 BS |
3866 | |
3867 | if (parent) | |
c0ff4b85 | 3868 | parent_memcg = mem_cgroup_from_cont(parent); |
18f59ea7 BS |
3869 | |
3870 | cgroup_lock(); | |
567fb435 GC |
3871 | |
3872 | if (memcg->use_hierarchy == val) | |
3873 | goto out; | |
3874 | ||
18f59ea7 | 3875 | /* |
af901ca1 | 3876 | * If parent's use_hierarchy is set, we can't make any modifications |
18f59ea7 BS |
3877 | * in the child subtrees. If it is unset, then the change can |
3878 | * occur, provided the current cgroup has no children. | |
3879 | * | |
3880 | * For the root cgroup, parent_mem is NULL, we allow value to be | |
3881 | * set if there are no children. | |
3882 | */ | |
c0ff4b85 | 3883 | if ((!parent_memcg || !parent_memcg->use_hierarchy) && |
18f59ea7 BS |
3884 | (val == 1 || val == 0)) { |
3885 | if (list_empty(&cont->children)) | |
c0ff4b85 | 3886 | memcg->use_hierarchy = val; |
18f59ea7 BS |
3887 | else |
3888 | retval = -EBUSY; | |
3889 | } else | |
3890 | retval = -EINVAL; | |
567fb435 GC |
3891 | |
3892 | out: | |
18f59ea7 BS |
3893 | cgroup_unlock(); |
3894 | ||
3895 | return retval; | |
3896 | } | |
3897 | ||
0c3e73e8 | 3898 | |
c0ff4b85 | 3899 | static unsigned long mem_cgroup_recursive_stat(struct mem_cgroup *memcg, |
7a159cc9 | 3900 | enum mem_cgroup_stat_index idx) |
0c3e73e8 | 3901 | { |
7d74b06f | 3902 | struct mem_cgroup *iter; |
7a159cc9 | 3903 | long val = 0; |
0c3e73e8 | 3904 | |
7a159cc9 | 3905 | /* Per-cpu values can be negative, use a signed accumulator */ |
c0ff4b85 | 3906 | for_each_mem_cgroup_tree(iter, memcg) |
7d74b06f KH |
3907 | val += mem_cgroup_read_stat(iter, idx); |
3908 | ||
3909 | if (val < 0) /* race ? */ | |
3910 | val = 0; | |
3911 | return val; | |
0c3e73e8 BS |
3912 | } |
3913 | ||
c0ff4b85 | 3914 | static inline u64 mem_cgroup_usage(struct mem_cgroup *memcg, bool swap) |
104f3928 | 3915 | { |
7d74b06f | 3916 | u64 val; |
104f3928 | 3917 | |
c0ff4b85 | 3918 | if (!mem_cgroup_is_root(memcg)) { |
104f3928 | 3919 | if (!swap) |
65c64ce8 | 3920 | return res_counter_read_u64(&memcg->res, RES_USAGE); |
104f3928 | 3921 | else |
65c64ce8 | 3922 | return res_counter_read_u64(&memcg->memsw, RES_USAGE); |
104f3928 KS |
3923 | } |
3924 | ||
c0ff4b85 R |
3925 | val = mem_cgroup_recursive_stat(memcg, MEM_CGROUP_STAT_CACHE); |
3926 | val += mem_cgroup_recursive_stat(memcg, MEM_CGROUP_STAT_RSS); | |
104f3928 | 3927 | |
7d74b06f | 3928 | if (swap) |
bff6bb83 | 3929 | val += mem_cgroup_recursive_stat(memcg, MEM_CGROUP_STAT_SWAP); |
104f3928 KS |
3930 | |
3931 | return val << PAGE_SHIFT; | |
3932 | } | |
3933 | ||
af36f906 TH |
3934 | static ssize_t mem_cgroup_read(struct cgroup *cont, struct cftype *cft, |
3935 | struct file *file, char __user *buf, | |
3936 | size_t nbytes, loff_t *ppos) | |
8cdea7c0 | 3937 | { |
c0ff4b85 | 3938 | struct mem_cgroup *memcg = mem_cgroup_from_cont(cont); |
af36f906 | 3939 | char str[64]; |
104f3928 | 3940 | u64 val; |
af36f906 | 3941 | int type, name, len; |
8c7c6e34 KH |
3942 | |
3943 | type = MEMFILE_TYPE(cft->private); | |
3944 | name = MEMFILE_ATTR(cft->private); | |
af36f906 TH |
3945 | |
3946 | if (!do_swap_account && type == _MEMSWAP) | |
3947 | return -EOPNOTSUPP; | |
3948 | ||
8c7c6e34 KH |
3949 | switch (type) { |
3950 | case _MEM: | |
104f3928 | 3951 | if (name == RES_USAGE) |
c0ff4b85 | 3952 | val = mem_cgroup_usage(memcg, false); |
104f3928 | 3953 | else |
c0ff4b85 | 3954 | val = res_counter_read_u64(&memcg->res, name); |
8c7c6e34 KH |
3955 | break; |
3956 | case _MEMSWAP: | |
104f3928 | 3957 | if (name == RES_USAGE) |
c0ff4b85 | 3958 | val = mem_cgroup_usage(memcg, true); |
104f3928 | 3959 | else |
c0ff4b85 | 3960 | val = res_counter_read_u64(&memcg->memsw, name); |
8c7c6e34 KH |
3961 | break; |
3962 | default: | |
3963 | BUG(); | |
8c7c6e34 | 3964 | } |
af36f906 TH |
3965 | |
3966 | len = scnprintf(str, sizeof(str), "%llu\n", (unsigned long long)val); | |
3967 | return simple_read_from_buffer(buf, nbytes, ppos, str, len); | |
8cdea7c0 | 3968 | } |
628f4235 KH |
3969 | /* |
3970 | * The user of this function is... | |
3971 | * RES_LIMIT. | |
3972 | */ | |
856c13aa PM |
3973 | static int mem_cgroup_write(struct cgroup *cont, struct cftype *cft, |
3974 | const char *buffer) | |
8cdea7c0 | 3975 | { |
628f4235 | 3976 | struct mem_cgroup *memcg = mem_cgroup_from_cont(cont); |
8c7c6e34 | 3977 | int type, name; |
628f4235 KH |
3978 | unsigned long long val; |
3979 | int ret; | |
3980 | ||
8c7c6e34 KH |
3981 | type = MEMFILE_TYPE(cft->private); |
3982 | name = MEMFILE_ATTR(cft->private); | |
af36f906 TH |
3983 | |
3984 | if (!do_swap_account && type == _MEMSWAP) | |
3985 | return -EOPNOTSUPP; | |
3986 | ||
8c7c6e34 | 3987 | switch (name) { |
628f4235 | 3988 | case RES_LIMIT: |
4b3bde4c BS |
3989 | if (mem_cgroup_is_root(memcg)) { /* Can't set limit on root */ |
3990 | ret = -EINVAL; | |
3991 | break; | |
3992 | } | |
628f4235 KH |
3993 | /* This function does all necessary parse...reuse it */ |
3994 | ret = res_counter_memparse_write_strategy(buffer, &val); | |
8c7c6e34 KH |
3995 | if (ret) |
3996 | break; | |
3997 | if (type == _MEM) | |
628f4235 | 3998 | ret = mem_cgroup_resize_limit(memcg, val); |
8c7c6e34 KH |
3999 | else |
4000 | ret = mem_cgroup_resize_memsw_limit(memcg, val); | |
628f4235 | 4001 | break; |
296c81d8 BS |
4002 | case RES_SOFT_LIMIT: |
4003 | ret = res_counter_memparse_write_strategy(buffer, &val); | |
4004 | if (ret) | |
4005 | break; | |
4006 | /* | |
4007 | * For memsw, soft limits are hard to implement in terms | |
4008 | * of semantics, for now, we support soft limits for | |
4009 | * control without swap | |
4010 | */ | |
4011 | if (type == _MEM) | |
4012 | ret = res_counter_set_soft_limit(&memcg->res, val); | |
4013 | else | |
4014 | ret = -EINVAL; | |
4015 | break; | |
628f4235 KH |
4016 | default: |
4017 | ret = -EINVAL; /* should be BUG() ? */ | |
4018 | break; | |
4019 | } | |
4020 | return ret; | |
8cdea7c0 BS |
4021 | } |
4022 | ||
fee7b548 KH |
4023 | static void memcg_get_hierarchical_limit(struct mem_cgroup *memcg, |
4024 | unsigned long long *mem_limit, unsigned long long *memsw_limit) | |
4025 | { | |
4026 | struct cgroup *cgroup; | |
4027 | unsigned long long min_limit, min_memsw_limit, tmp; | |
4028 | ||
4029 | min_limit = res_counter_read_u64(&memcg->res, RES_LIMIT); | |
4030 | min_memsw_limit = res_counter_read_u64(&memcg->memsw, RES_LIMIT); | |
4031 | cgroup = memcg->css.cgroup; | |
4032 | if (!memcg->use_hierarchy) | |
4033 | goto out; | |
4034 | ||
4035 | while (cgroup->parent) { | |
4036 | cgroup = cgroup->parent; | |
4037 | memcg = mem_cgroup_from_cont(cgroup); | |
4038 | if (!memcg->use_hierarchy) | |
4039 | break; | |
4040 | tmp = res_counter_read_u64(&memcg->res, RES_LIMIT); | |
4041 | min_limit = min(min_limit, tmp); | |
4042 | tmp = res_counter_read_u64(&memcg->memsw, RES_LIMIT); | |
4043 | min_memsw_limit = min(min_memsw_limit, tmp); | |
4044 | } | |
4045 | out: | |
4046 | *mem_limit = min_limit; | |
4047 | *memsw_limit = min_memsw_limit; | |
fee7b548 KH |
4048 | } |
4049 | ||
29f2a4da | 4050 | static int mem_cgroup_reset(struct cgroup *cont, unsigned int event) |
c84872e1 | 4051 | { |
af36f906 | 4052 | struct mem_cgroup *memcg = mem_cgroup_from_cont(cont); |
8c7c6e34 | 4053 | int type, name; |
c84872e1 | 4054 | |
8c7c6e34 KH |
4055 | type = MEMFILE_TYPE(event); |
4056 | name = MEMFILE_ATTR(event); | |
af36f906 TH |
4057 | |
4058 | if (!do_swap_account && type == _MEMSWAP) | |
4059 | return -EOPNOTSUPP; | |
4060 | ||
8c7c6e34 | 4061 | switch (name) { |
29f2a4da | 4062 | case RES_MAX_USAGE: |
8c7c6e34 | 4063 | if (type == _MEM) |
c0ff4b85 | 4064 | res_counter_reset_max(&memcg->res); |
8c7c6e34 | 4065 | else |
c0ff4b85 | 4066 | res_counter_reset_max(&memcg->memsw); |
29f2a4da PE |
4067 | break; |
4068 | case RES_FAILCNT: | |
8c7c6e34 | 4069 | if (type == _MEM) |
c0ff4b85 | 4070 | res_counter_reset_failcnt(&memcg->res); |
8c7c6e34 | 4071 | else |
c0ff4b85 | 4072 | res_counter_reset_failcnt(&memcg->memsw); |
29f2a4da PE |
4073 | break; |
4074 | } | |
f64c3f54 | 4075 | |
85cc59db | 4076 | return 0; |
c84872e1 PE |
4077 | } |
4078 | ||
7dc74be0 DN |
4079 | static u64 mem_cgroup_move_charge_read(struct cgroup *cgrp, |
4080 | struct cftype *cft) | |
4081 | { | |
4082 | return mem_cgroup_from_cont(cgrp)->move_charge_at_immigrate; | |
4083 | } | |
4084 | ||
02491447 | 4085 | #ifdef CONFIG_MMU |
7dc74be0 DN |
4086 | static int mem_cgroup_move_charge_write(struct cgroup *cgrp, |
4087 | struct cftype *cft, u64 val) | |
4088 | { | |
c0ff4b85 | 4089 | struct mem_cgroup *memcg = mem_cgroup_from_cont(cgrp); |
7dc74be0 DN |
4090 | |
4091 | if (val >= (1 << NR_MOVE_TYPE)) | |
4092 | return -EINVAL; | |
4093 | /* | |
4094 | * We check this value several times in both in can_attach() and | |
4095 | * attach(), so we need cgroup lock to prevent this value from being | |
4096 | * inconsistent. | |
4097 | */ | |
4098 | cgroup_lock(); | |
c0ff4b85 | 4099 | memcg->move_charge_at_immigrate = val; |
7dc74be0 DN |
4100 | cgroup_unlock(); |
4101 | ||
4102 | return 0; | |
4103 | } | |
02491447 DN |
4104 | #else |
4105 | static int mem_cgroup_move_charge_write(struct cgroup *cgrp, | |
4106 | struct cftype *cft, u64 val) | |
4107 | { | |
4108 | return -ENOSYS; | |
4109 | } | |
4110 | #endif | |
7dc74be0 | 4111 | |
406eb0c9 | 4112 | #ifdef CONFIG_NUMA |
ab215884 | 4113 | static int memcg_numa_stat_show(struct cgroup *cont, struct cftype *cft, |
fada52ca | 4114 | struct seq_file *m) |
406eb0c9 YH |
4115 | { |
4116 | int nid; | |
4117 | unsigned long total_nr, file_nr, anon_nr, unevictable_nr; | |
4118 | unsigned long node_nr; | |
d79154bb | 4119 | struct mem_cgroup *memcg = mem_cgroup_from_cont(cont); |
406eb0c9 | 4120 | |
d79154bb | 4121 | total_nr = mem_cgroup_nr_lru_pages(memcg, LRU_ALL); |
406eb0c9 YH |
4122 | seq_printf(m, "total=%lu", total_nr); |
4123 | for_each_node_state(nid, N_HIGH_MEMORY) { | |
d79154bb | 4124 | node_nr = mem_cgroup_node_nr_lru_pages(memcg, nid, LRU_ALL); |
406eb0c9 YH |
4125 | seq_printf(m, " N%d=%lu", nid, node_nr); |
4126 | } | |
4127 | seq_putc(m, '\n'); | |
4128 | ||
d79154bb | 4129 | file_nr = mem_cgroup_nr_lru_pages(memcg, LRU_ALL_FILE); |
406eb0c9 YH |
4130 | seq_printf(m, "file=%lu", file_nr); |
4131 | for_each_node_state(nid, N_HIGH_MEMORY) { | |
d79154bb | 4132 | node_nr = mem_cgroup_node_nr_lru_pages(memcg, nid, |
bb2a0de9 | 4133 | LRU_ALL_FILE); |
406eb0c9 YH |
4134 | seq_printf(m, " N%d=%lu", nid, node_nr); |
4135 | } | |
4136 | seq_putc(m, '\n'); | |
4137 | ||
d79154bb | 4138 | anon_nr = mem_cgroup_nr_lru_pages(memcg, LRU_ALL_ANON); |
406eb0c9 YH |
4139 | seq_printf(m, "anon=%lu", anon_nr); |
4140 | for_each_node_state(nid, N_HIGH_MEMORY) { | |
d79154bb | 4141 | node_nr = mem_cgroup_node_nr_lru_pages(memcg, nid, |
bb2a0de9 | 4142 | LRU_ALL_ANON); |
406eb0c9 YH |
4143 | seq_printf(m, " N%d=%lu", nid, node_nr); |
4144 | } | |
4145 | seq_putc(m, '\n'); | |
4146 | ||
d79154bb | 4147 | unevictable_nr = mem_cgroup_nr_lru_pages(memcg, BIT(LRU_UNEVICTABLE)); |
406eb0c9 YH |
4148 | seq_printf(m, "unevictable=%lu", unevictable_nr); |
4149 | for_each_node_state(nid, N_HIGH_MEMORY) { | |
d79154bb | 4150 | node_nr = mem_cgroup_node_nr_lru_pages(memcg, nid, |
bb2a0de9 | 4151 | BIT(LRU_UNEVICTABLE)); |
406eb0c9 YH |
4152 | seq_printf(m, " N%d=%lu", nid, node_nr); |
4153 | } | |
4154 | seq_putc(m, '\n'); | |
4155 | return 0; | |
4156 | } | |
4157 | #endif /* CONFIG_NUMA */ | |
4158 | ||
af7c4b0e JW |
4159 | static const char * const mem_cgroup_lru_names[] = { |
4160 | "inactive_anon", | |
4161 | "active_anon", | |
4162 | "inactive_file", | |
4163 | "active_file", | |
4164 | "unevictable", | |
4165 | }; | |
4166 | ||
4167 | static inline void mem_cgroup_lru_names_not_uptodate(void) | |
4168 | { | |
4169 | BUILD_BUG_ON(ARRAY_SIZE(mem_cgroup_lru_names) != NR_LRU_LISTS); | |
4170 | } | |
4171 | ||
ab215884 | 4172 | static int memcg_stat_show(struct cgroup *cont, struct cftype *cft, |
78ccf5b5 | 4173 | struct seq_file *m) |
d2ceb9b7 | 4174 | { |
d79154bb | 4175 | struct mem_cgroup *memcg = mem_cgroup_from_cont(cont); |
af7c4b0e JW |
4176 | struct mem_cgroup *mi; |
4177 | unsigned int i; | |
406eb0c9 | 4178 | |
af7c4b0e | 4179 | for (i = 0; i < MEM_CGROUP_STAT_NSTATS; i++) { |
bff6bb83 | 4180 | if (i == MEM_CGROUP_STAT_SWAP && !do_swap_account) |
1dd3a273 | 4181 | continue; |
af7c4b0e JW |
4182 | seq_printf(m, "%s %ld\n", mem_cgroup_stat_names[i], |
4183 | mem_cgroup_read_stat(memcg, i) * PAGE_SIZE); | |
1dd3a273 | 4184 | } |
7b854121 | 4185 | |
af7c4b0e JW |
4186 | for (i = 0; i < MEM_CGROUP_EVENTS_NSTATS; i++) |
4187 | seq_printf(m, "%s %lu\n", mem_cgroup_events_names[i], | |
4188 | mem_cgroup_read_events(memcg, i)); | |
4189 | ||
4190 | for (i = 0; i < NR_LRU_LISTS; i++) | |
4191 | seq_printf(m, "%s %lu\n", mem_cgroup_lru_names[i], | |
4192 | mem_cgroup_nr_lru_pages(memcg, BIT(i)) * PAGE_SIZE); | |
4193 | ||
14067bb3 | 4194 | /* Hierarchical information */ |
fee7b548 KH |
4195 | { |
4196 | unsigned long long limit, memsw_limit; | |
d79154bb | 4197 | memcg_get_hierarchical_limit(memcg, &limit, &memsw_limit); |
78ccf5b5 | 4198 | seq_printf(m, "hierarchical_memory_limit %llu\n", limit); |
fee7b548 | 4199 | if (do_swap_account) |
78ccf5b5 JW |
4200 | seq_printf(m, "hierarchical_memsw_limit %llu\n", |
4201 | memsw_limit); | |
fee7b548 | 4202 | } |
7f016ee8 | 4203 | |
af7c4b0e JW |
4204 | for (i = 0; i < MEM_CGROUP_STAT_NSTATS; i++) { |
4205 | long long val = 0; | |
4206 | ||
bff6bb83 | 4207 | if (i == MEM_CGROUP_STAT_SWAP && !do_swap_account) |
1dd3a273 | 4208 | continue; |
af7c4b0e JW |
4209 | for_each_mem_cgroup_tree(mi, memcg) |
4210 | val += mem_cgroup_read_stat(mi, i) * PAGE_SIZE; | |
4211 | seq_printf(m, "total_%s %lld\n", mem_cgroup_stat_names[i], val); | |
4212 | } | |
4213 | ||
4214 | for (i = 0; i < MEM_CGROUP_EVENTS_NSTATS; i++) { | |
4215 | unsigned long long val = 0; | |
4216 | ||
4217 | for_each_mem_cgroup_tree(mi, memcg) | |
4218 | val += mem_cgroup_read_events(mi, i); | |
4219 | seq_printf(m, "total_%s %llu\n", | |
4220 | mem_cgroup_events_names[i], val); | |
4221 | } | |
4222 | ||
4223 | for (i = 0; i < NR_LRU_LISTS; i++) { | |
4224 | unsigned long long val = 0; | |
4225 | ||
4226 | for_each_mem_cgroup_tree(mi, memcg) | |
4227 | val += mem_cgroup_nr_lru_pages(mi, BIT(i)) * PAGE_SIZE; | |
4228 | seq_printf(m, "total_%s %llu\n", mem_cgroup_lru_names[i], val); | |
1dd3a273 | 4229 | } |
14067bb3 | 4230 | |
7f016ee8 | 4231 | #ifdef CONFIG_DEBUG_VM |
7f016ee8 KM |
4232 | { |
4233 | int nid, zid; | |
4234 | struct mem_cgroup_per_zone *mz; | |
89abfab1 | 4235 | struct zone_reclaim_stat *rstat; |
7f016ee8 KM |
4236 | unsigned long recent_rotated[2] = {0, 0}; |
4237 | unsigned long recent_scanned[2] = {0, 0}; | |
4238 | ||
4239 | for_each_online_node(nid) | |
4240 | for (zid = 0; zid < MAX_NR_ZONES; zid++) { | |
d79154bb | 4241 | mz = mem_cgroup_zoneinfo(memcg, nid, zid); |
89abfab1 | 4242 | rstat = &mz->lruvec.reclaim_stat; |
7f016ee8 | 4243 | |
89abfab1 HD |
4244 | recent_rotated[0] += rstat->recent_rotated[0]; |
4245 | recent_rotated[1] += rstat->recent_rotated[1]; | |
4246 | recent_scanned[0] += rstat->recent_scanned[0]; | |
4247 | recent_scanned[1] += rstat->recent_scanned[1]; | |
7f016ee8 | 4248 | } |
78ccf5b5 JW |
4249 | seq_printf(m, "recent_rotated_anon %lu\n", recent_rotated[0]); |
4250 | seq_printf(m, "recent_rotated_file %lu\n", recent_rotated[1]); | |
4251 | seq_printf(m, "recent_scanned_anon %lu\n", recent_scanned[0]); | |
4252 | seq_printf(m, "recent_scanned_file %lu\n", recent_scanned[1]); | |
7f016ee8 KM |
4253 | } |
4254 | #endif | |
4255 | ||
d2ceb9b7 KH |
4256 | return 0; |
4257 | } | |
4258 | ||
a7885eb8 KM |
4259 | static u64 mem_cgroup_swappiness_read(struct cgroup *cgrp, struct cftype *cft) |
4260 | { | |
4261 | struct mem_cgroup *memcg = mem_cgroup_from_cont(cgrp); | |
4262 | ||
1f4c025b | 4263 | return mem_cgroup_swappiness(memcg); |
a7885eb8 KM |
4264 | } |
4265 | ||
4266 | static int mem_cgroup_swappiness_write(struct cgroup *cgrp, struct cftype *cft, | |
4267 | u64 val) | |
4268 | { | |
4269 | struct mem_cgroup *memcg = mem_cgroup_from_cont(cgrp); | |
4270 | struct mem_cgroup *parent; | |
068b38c1 | 4271 | |
a7885eb8 KM |
4272 | if (val > 100) |
4273 | return -EINVAL; | |
4274 | ||
4275 | if (cgrp->parent == NULL) | |
4276 | return -EINVAL; | |
4277 | ||
4278 | parent = mem_cgroup_from_cont(cgrp->parent); | |
068b38c1 LZ |
4279 | |
4280 | cgroup_lock(); | |
4281 | ||
a7885eb8 KM |
4282 | /* If under hierarchy, only empty-root can set this value */ |
4283 | if ((parent->use_hierarchy) || | |
068b38c1 LZ |
4284 | (memcg->use_hierarchy && !list_empty(&cgrp->children))) { |
4285 | cgroup_unlock(); | |
a7885eb8 | 4286 | return -EINVAL; |
068b38c1 | 4287 | } |
a7885eb8 | 4288 | |
a7885eb8 | 4289 | memcg->swappiness = val; |
a7885eb8 | 4290 | |
068b38c1 LZ |
4291 | cgroup_unlock(); |
4292 | ||
a7885eb8 KM |
4293 | return 0; |
4294 | } | |
4295 | ||
2e72b634 KS |
4296 | static void __mem_cgroup_threshold(struct mem_cgroup *memcg, bool swap) |
4297 | { | |
4298 | struct mem_cgroup_threshold_ary *t; | |
4299 | u64 usage; | |
4300 | int i; | |
4301 | ||
4302 | rcu_read_lock(); | |
4303 | if (!swap) | |
2c488db2 | 4304 | t = rcu_dereference(memcg->thresholds.primary); |
2e72b634 | 4305 | else |
2c488db2 | 4306 | t = rcu_dereference(memcg->memsw_thresholds.primary); |
2e72b634 KS |
4307 | |
4308 | if (!t) | |
4309 | goto unlock; | |
4310 | ||
4311 | usage = mem_cgroup_usage(memcg, swap); | |
4312 | ||
4313 | /* | |
748dad36 | 4314 | * current_threshold points to threshold just below or equal to usage. |
2e72b634 KS |
4315 | * If it's not true, a threshold was crossed after last |
4316 | * call of __mem_cgroup_threshold(). | |
4317 | */ | |
5407a562 | 4318 | i = t->current_threshold; |
2e72b634 KS |
4319 | |
4320 | /* | |
4321 | * Iterate backward over array of thresholds starting from | |
4322 | * current_threshold and check if a threshold is crossed. | |
4323 | * If none of thresholds below usage is crossed, we read | |
4324 | * only one element of the array here. | |
4325 | */ | |
4326 | for (; i >= 0 && unlikely(t->entries[i].threshold > usage); i--) | |
4327 | eventfd_signal(t->entries[i].eventfd, 1); | |
4328 | ||
4329 | /* i = current_threshold + 1 */ | |
4330 | i++; | |
4331 | ||
4332 | /* | |
4333 | * Iterate forward over array of thresholds starting from | |
4334 | * current_threshold+1 and check if a threshold is crossed. | |
4335 | * If none of thresholds above usage is crossed, we read | |
4336 | * only one element of the array here. | |
4337 | */ | |
4338 | for (; i < t->size && unlikely(t->entries[i].threshold <= usage); i++) | |
4339 | eventfd_signal(t->entries[i].eventfd, 1); | |
4340 | ||
4341 | /* Update current_threshold */ | |
5407a562 | 4342 | t->current_threshold = i - 1; |
2e72b634 KS |
4343 | unlock: |
4344 | rcu_read_unlock(); | |
4345 | } | |
4346 | ||
4347 | static void mem_cgroup_threshold(struct mem_cgroup *memcg) | |
4348 | { | |
ad4ca5f4 KS |
4349 | while (memcg) { |
4350 | __mem_cgroup_threshold(memcg, false); | |
4351 | if (do_swap_account) | |
4352 | __mem_cgroup_threshold(memcg, true); | |
4353 | ||
4354 | memcg = parent_mem_cgroup(memcg); | |
4355 | } | |
2e72b634 KS |
4356 | } |
4357 | ||
4358 | static int compare_thresholds(const void *a, const void *b) | |
4359 | { | |
4360 | const struct mem_cgroup_threshold *_a = a; | |
4361 | const struct mem_cgroup_threshold *_b = b; | |
4362 | ||
4363 | return _a->threshold - _b->threshold; | |
4364 | } | |
4365 | ||
c0ff4b85 | 4366 | static int mem_cgroup_oom_notify_cb(struct mem_cgroup *memcg) |
9490ff27 KH |
4367 | { |
4368 | struct mem_cgroup_eventfd_list *ev; | |
4369 | ||
c0ff4b85 | 4370 | list_for_each_entry(ev, &memcg->oom_notify, list) |
9490ff27 KH |
4371 | eventfd_signal(ev->eventfd, 1); |
4372 | return 0; | |
4373 | } | |
4374 | ||
c0ff4b85 | 4375 | static void mem_cgroup_oom_notify(struct mem_cgroup *memcg) |
9490ff27 | 4376 | { |
7d74b06f KH |
4377 | struct mem_cgroup *iter; |
4378 | ||
c0ff4b85 | 4379 | for_each_mem_cgroup_tree(iter, memcg) |
7d74b06f | 4380 | mem_cgroup_oom_notify_cb(iter); |
9490ff27 KH |
4381 | } |
4382 | ||
4383 | static int mem_cgroup_usage_register_event(struct cgroup *cgrp, | |
4384 | struct cftype *cft, struct eventfd_ctx *eventfd, const char *args) | |
2e72b634 KS |
4385 | { |
4386 | struct mem_cgroup *memcg = mem_cgroup_from_cont(cgrp); | |
2c488db2 KS |
4387 | struct mem_cgroup_thresholds *thresholds; |
4388 | struct mem_cgroup_threshold_ary *new; | |
2e72b634 KS |
4389 | int type = MEMFILE_TYPE(cft->private); |
4390 | u64 threshold, usage; | |
2c488db2 | 4391 | int i, size, ret; |
2e72b634 KS |
4392 | |
4393 | ret = res_counter_memparse_write_strategy(args, &threshold); | |
4394 | if (ret) | |
4395 | return ret; | |
4396 | ||
4397 | mutex_lock(&memcg->thresholds_lock); | |
2c488db2 | 4398 | |
2e72b634 | 4399 | if (type == _MEM) |
2c488db2 | 4400 | thresholds = &memcg->thresholds; |
2e72b634 | 4401 | else if (type == _MEMSWAP) |
2c488db2 | 4402 | thresholds = &memcg->memsw_thresholds; |
2e72b634 KS |
4403 | else |
4404 | BUG(); | |
4405 | ||
4406 | usage = mem_cgroup_usage(memcg, type == _MEMSWAP); | |
4407 | ||
4408 | /* Check if a threshold crossed before adding a new one */ | |
2c488db2 | 4409 | if (thresholds->primary) |
2e72b634 KS |
4410 | __mem_cgroup_threshold(memcg, type == _MEMSWAP); |
4411 | ||
2c488db2 | 4412 | size = thresholds->primary ? thresholds->primary->size + 1 : 1; |
2e72b634 KS |
4413 | |
4414 | /* Allocate memory for new array of thresholds */ | |
2c488db2 | 4415 | new = kmalloc(sizeof(*new) + size * sizeof(struct mem_cgroup_threshold), |
2e72b634 | 4416 | GFP_KERNEL); |
2c488db2 | 4417 | if (!new) { |
2e72b634 KS |
4418 | ret = -ENOMEM; |
4419 | goto unlock; | |
4420 | } | |
2c488db2 | 4421 | new->size = size; |
2e72b634 KS |
4422 | |
4423 | /* Copy thresholds (if any) to new array */ | |
2c488db2 KS |
4424 | if (thresholds->primary) { |
4425 | memcpy(new->entries, thresholds->primary->entries, (size - 1) * | |
2e72b634 | 4426 | sizeof(struct mem_cgroup_threshold)); |
2c488db2 KS |
4427 | } |
4428 | ||
2e72b634 | 4429 | /* Add new threshold */ |
2c488db2 KS |
4430 | new->entries[size - 1].eventfd = eventfd; |
4431 | new->entries[size - 1].threshold = threshold; | |
2e72b634 KS |
4432 | |
4433 | /* Sort thresholds. Registering of new threshold isn't time-critical */ | |
2c488db2 | 4434 | sort(new->entries, size, sizeof(struct mem_cgroup_threshold), |
2e72b634 KS |
4435 | compare_thresholds, NULL); |
4436 | ||
4437 | /* Find current threshold */ | |
2c488db2 | 4438 | new->current_threshold = -1; |
2e72b634 | 4439 | for (i = 0; i < size; i++) { |
748dad36 | 4440 | if (new->entries[i].threshold <= usage) { |
2e72b634 | 4441 | /* |
2c488db2 KS |
4442 | * new->current_threshold will not be used until |
4443 | * rcu_assign_pointer(), so it's safe to increment | |
2e72b634 KS |
4444 | * it here. |
4445 | */ | |
2c488db2 | 4446 | ++new->current_threshold; |
748dad36 SZ |
4447 | } else |
4448 | break; | |
2e72b634 KS |
4449 | } |
4450 | ||
2c488db2 KS |
4451 | /* Free old spare buffer and save old primary buffer as spare */ |
4452 | kfree(thresholds->spare); | |
4453 | thresholds->spare = thresholds->primary; | |
4454 | ||
4455 | rcu_assign_pointer(thresholds->primary, new); | |
2e72b634 | 4456 | |
907860ed | 4457 | /* To be sure that nobody uses thresholds */ |
2e72b634 KS |
4458 | synchronize_rcu(); |
4459 | ||
2e72b634 KS |
4460 | unlock: |
4461 | mutex_unlock(&memcg->thresholds_lock); | |
4462 | ||
4463 | return ret; | |
4464 | } | |
4465 | ||
907860ed | 4466 | static void mem_cgroup_usage_unregister_event(struct cgroup *cgrp, |
9490ff27 | 4467 | struct cftype *cft, struct eventfd_ctx *eventfd) |
2e72b634 KS |
4468 | { |
4469 | struct mem_cgroup *memcg = mem_cgroup_from_cont(cgrp); | |
2c488db2 KS |
4470 | struct mem_cgroup_thresholds *thresholds; |
4471 | struct mem_cgroup_threshold_ary *new; | |
2e72b634 KS |
4472 | int type = MEMFILE_TYPE(cft->private); |
4473 | u64 usage; | |
2c488db2 | 4474 | int i, j, size; |
2e72b634 KS |
4475 | |
4476 | mutex_lock(&memcg->thresholds_lock); | |
4477 | if (type == _MEM) | |
2c488db2 | 4478 | thresholds = &memcg->thresholds; |
2e72b634 | 4479 | else if (type == _MEMSWAP) |
2c488db2 | 4480 | thresholds = &memcg->memsw_thresholds; |
2e72b634 KS |
4481 | else |
4482 | BUG(); | |
4483 | ||
371528ca AV |
4484 | if (!thresholds->primary) |
4485 | goto unlock; | |
4486 | ||
2e72b634 KS |
4487 | usage = mem_cgroup_usage(memcg, type == _MEMSWAP); |
4488 | ||
4489 | /* Check if a threshold crossed before removing */ | |
4490 | __mem_cgroup_threshold(memcg, type == _MEMSWAP); | |
4491 | ||
4492 | /* Calculate new number of threshold */ | |
2c488db2 KS |
4493 | size = 0; |
4494 | for (i = 0; i < thresholds->primary->size; i++) { | |
4495 | if (thresholds->primary->entries[i].eventfd != eventfd) | |
2e72b634 KS |
4496 | size++; |
4497 | } | |
4498 | ||
2c488db2 | 4499 | new = thresholds->spare; |
907860ed | 4500 | |
2e72b634 KS |
4501 | /* Set thresholds array to NULL if we don't have thresholds */ |
4502 | if (!size) { | |
2c488db2 KS |
4503 | kfree(new); |
4504 | new = NULL; | |
907860ed | 4505 | goto swap_buffers; |
2e72b634 KS |
4506 | } |
4507 | ||
2c488db2 | 4508 | new->size = size; |
2e72b634 KS |
4509 | |
4510 | /* Copy thresholds and find current threshold */ | |
2c488db2 KS |
4511 | new->current_threshold = -1; |
4512 | for (i = 0, j = 0; i < thresholds->primary->size; i++) { | |
4513 | if (thresholds->primary->entries[i].eventfd == eventfd) | |
2e72b634 KS |
4514 | continue; |
4515 | ||
2c488db2 | 4516 | new->entries[j] = thresholds->primary->entries[i]; |
748dad36 | 4517 | if (new->entries[j].threshold <= usage) { |
2e72b634 | 4518 | /* |
2c488db2 | 4519 | * new->current_threshold will not be used |
2e72b634 KS |
4520 | * until rcu_assign_pointer(), so it's safe to increment |
4521 | * it here. | |
4522 | */ | |
2c488db2 | 4523 | ++new->current_threshold; |
2e72b634 KS |
4524 | } |
4525 | j++; | |
4526 | } | |
4527 | ||
907860ed | 4528 | swap_buffers: |
2c488db2 KS |
4529 | /* Swap primary and spare array */ |
4530 | thresholds->spare = thresholds->primary; | |
8c757763 SZ |
4531 | /* If all events are unregistered, free the spare array */ |
4532 | if (!new) { | |
4533 | kfree(thresholds->spare); | |
4534 | thresholds->spare = NULL; | |
4535 | } | |
4536 | ||
2c488db2 | 4537 | rcu_assign_pointer(thresholds->primary, new); |
2e72b634 | 4538 | |
907860ed | 4539 | /* To be sure that nobody uses thresholds */ |
2e72b634 | 4540 | synchronize_rcu(); |
371528ca | 4541 | unlock: |
2e72b634 | 4542 | mutex_unlock(&memcg->thresholds_lock); |
2e72b634 | 4543 | } |
c1e862c1 | 4544 | |
9490ff27 KH |
4545 | static int mem_cgroup_oom_register_event(struct cgroup *cgrp, |
4546 | struct cftype *cft, struct eventfd_ctx *eventfd, const char *args) | |
4547 | { | |
4548 | struct mem_cgroup *memcg = mem_cgroup_from_cont(cgrp); | |
4549 | struct mem_cgroup_eventfd_list *event; | |
4550 | int type = MEMFILE_TYPE(cft->private); | |
4551 | ||
4552 | BUG_ON(type != _OOM_TYPE); | |
4553 | event = kmalloc(sizeof(*event), GFP_KERNEL); | |
4554 | if (!event) | |
4555 | return -ENOMEM; | |
4556 | ||
1af8efe9 | 4557 | spin_lock(&memcg_oom_lock); |
9490ff27 KH |
4558 | |
4559 | event->eventfd = eventfd; | |
4560 | list_add(&event->list, &memcg->oom_notify); | |
4561 | ||
4562 | /* already in OOM ? */ | |
79dfdacc | 4563 | if (atomic_read(&memcg->under_oom)) |
9490ff27 | 4564 | eventfd_signal(eventfd, 1); |
1af8efe9 | 4565 | spin_unlock(&memcg_oom_lock); |
9490ff27 KH |
4566 | |
4567 | return 0; | |
4568 | } | |
4569 | ||
907860ed | 4570 | static void mem_cgroup_oom_unregister_event(struct cgroup *cgrp, |
9490ff27 KH |
4571 | struct cftype *cft, struct eventfd_ctx *eventfd) |
4572 | { | |
c0ff4b85 | 4573 | struct mem_cgroup *memcg = mem_cgroup_from_cont(cgrp); |
9490ff27 KH |
4574 | struct mem_cgroup_eventfd_list *ev, *tmp; |
4575 | int type = MEMFILE_TYPE(cft->private); | |
4576 | ||
4577 | BUG_ON(type != _OOM_TYPE); | |
4578 | ||
1af8efe9 | 4579 | spin_lock(&memcg_oom_lock); |
9490ff27 | 4580 | |
c0ff4b85 | 4581 | list_for_each_entry_safe(ev, tmp, &memcg->oom_notify, list) { |
9490ff27 KH |
4582 | if (ev->eventfd == eventfd) { |
4583 | list_del(&ev->list); | |
4584 | kfree(ev); | |
4585 | } | |
4586 | } | |
4587 | ||
1af8efe9 | 4588 | spin_unlock(&memcg_oom_lock); |
9490ff27 KH |
4589 | } |
4590 | ||
3c11ecf4 KH |
4591 | static int mem_cgroup_oom_control_read(struct cgroup *cgrp, |
4592 | struct cftype *cft, struct cgroup_map_cb *cb) | |
4593 | { | |
c0ff4b85 | 4594 | struct mem_cgroup *memcg = mem_cgroup_from_cont(cgrp); |
3c11ecf4 | 4595 | |
c0ff4b85 | 4596 | cb->fill(cb, "oom_kill_disable", memcg->oom_kill_disable); |
3c11ecf4 | 4597 | |
c0ff4b85 | 4598 | if (atomic_read(&memcg->under_oom)) |
3c11ecf4 KH |
4599 | cb->fill(cb, "under_oom", 1); |
4600 | else | |
4601 | cb->fill(cb, "under_oom", 0); | |
4602 | return 0; | |
4603 | } | |
4604 | ||
3c11ecf4 KH |
4605 | static int mem_cgroup_oom_control_write(struct cgroup *cgrp, |
4606 | struct cftype *cft, u64 val) | |
4607 | { | |
c0ff4b85 | 4608 | struct mem_cgroup *memcg = mem_cgroup_from_cont(cgrp); |
3c11ecf4 KH |
4609 | struct mem_cgroup *parent; |
4610 | ||
4611 | /* cannot set to root cgroup and only 0 and 1 are allowed */ | |
4612 | if (!cgrp->parent || !((val == 0) || (val == 1))) | |
4613 | return -EINVAL; | |
4614 | ||
4615 | parent = mem_cgroup_from_cont(cgrp->parent); | |
4616 | ||
4617 | cgroup_lock(); | |
4618 | /* oom-kill-disable is a flag for subhierarchy. */ | |
4619 | if ((parent->use_hierarchy) || | |
c0ff4b85 | 4620 | (memcg->use_hierarchy && !list_empty(&cgrp->children))) { |
3c11ecf4 KH |
4621 | cgroup_unlock(); |
4622 | return -EINVAL; | |
4623 | } | |
c0ff4b85 | 4624 | memcg->oom_kill_disable = val; |
4d845ebf | 4625 | if (!val) |
c0ff4b85 | 4626 | memcg_oom_recover(memcg); |
3c11ecf4 KH |
4627 | cgroup_unlock(); |
4628 | return 0; | |
4629 | } | |
4630 | ||
c255a458 | 4631 | #ifdef CONFIG_MEMCG_KMEM |
cbe128e3 | 4632 | static int memcg_init_kmem(struct mem_cgroup *memcg, struct cgroup_subsys *ss) |
e5671dfa | 4633 | { |
1d62e436 | 4634 | return mem_cgroup_sockets_init(memcg, ss); |
e5671dfa GC |
4635 | }; |
4636 | ||
1d62e436 | 4637 | static void kmem_cgroup_destroy(struct mem_cgroup *memcg) |
d1a4c0b3 | 4638 | { |
1d62e436 | 4639 | mem_cgroup_sockets_destroy(memcg); |
d1a4c0b3 | 4640 | } |
e5671dfa | 4641 | #else |
cbe128e3 | 4642 | static int memcg_init_kmem(struct mem_cgroup *memcg, struct cgroup_subsys *ss) |
e5671dfa GC |
4643 | { |
4644 | return 0; | |
4645 | } | |
d1a4c0b3 | 4646 | |
1d62e436 | 4647 | static void kmem_cgroup_destroy(struct mem_cgroup *memcg) |
d1a4c0b3 GC |
4648 | { |
4649 | } | |
e5671dfa GC |
4650 | #endif |
4651 | ||
8cdea7c0 BS |
4652 | static struct cftype mem_cgroup_files[] = { |
4653 | { | |
0eea1030 | 4654 | .name = "usage_in_bytes", |
8c7c6e34 | 4655 | .private = MEMFILE_PRIVATE(_MEM, RES_USAGE), |
af36f906 | 4656 | .read = mem_cgroup_read, |
9490ff27 KH |
4657 | .register_event = mem_cgroup_usage_register_event, |
4658 | .unregister_event = mem_cgroup_usage_unregister_event, | |
8cdea7c0 | 4659 | }, |
c84872e1 PE |
4660 | { |
4661 | .name = "max_usage_in_bytes", | |
8c7c6e34 | 4662 | .private = MEMFILE_PRIVATE(_MEM, RES_MAX_USAGE), |
29f2a4da | 4663 | .trigger = mem_cgroup_reset, |
af36f906 | 4664 | .read = mem_cgroup_read, |
c84872e1 | 4665 | }, |
8cdea7c0 | 4666 | { |
0eea1030 | 4667 | .name = "limit_in_bytes", |
8c7c6e34 | 4668 | .private = MEMFILE_PRIVATE(_MEM, RES_LIMIT), |
856c13aa | 4669 | .write_string = mem_cgroup_write, |
af36f906 | 4670 | .read = mem_cgroup_read, |
8cdea7c0 | 4671 | }, |
296c81d8 BS |
4672 | { |
4673 | .name = "soft_limit_in_bytes", | |
4674 | .private = MEMFILE_PRIVATE(_MEM, RES_SOFT_LIMIT), | |
4675 | .write_string = mem_cgroup_write, | |
af36f906 | 4676 | .read = mem_cgroup_read, |
296c81d8 | 4677 | }, |
8cdea7c0 BS |
4678 | { |
4679 | .name = "failcnt", | |
8c7c6e34 | 4680 | .private = MEMFILE_PRIVATE(_MEM, RES_FAILCNT), |
29f2a4da | 4681 | .trigger = mem_cgroup_reset, |
af36f906 | 4682 | .read = mem_cgroup_read, |
8cdea7c0 | 4683 | }, |
d2ceb9b7 KH |
4684 | { |
4685 | .name = "stat", | |
ab215884 | 4686 | .read_seq_string = memcg_stat_show, |
d2ceb9b7 | 4687 | }, |
c1e862c1 KH |
4688 | { |
4689 | .name = "force_empty", | |
4690 | .trigger = mem_cgroup_force_empty_write, | |
4691 | }, | |
18f59ea7 BS |
4692 | { |
4693 | .name = "use_hierarchy", | |
4694 | .write_u64 = mem_cgroup_hierarchy_write, | |
4695 | .read_u64 = mem_cgroup_hierarchy_read, | |
4696 | }, | |
a7885eb8 KM |
4697 | { |
4698 | .name = "swappiness", | |
4699 | .read_u64 = mem_cgroup_swappiness_read, | |
4700 | .write_u64 = mem_cgroup_swappiness_write, | |
4701 | }, | |
7dc74be0 DN |
4702 | { |
4703 | .name = "move_charge_at_immigrate", | |
4704 | .read_u64 = mem_cgroup_move_charge_read, | |
4705 | .write_u64 = mem_cgroup_move_charge_write, | |
4706 | }, | |
9490ff27 KH |
4707 | { |
4708 | .name = "oom_control", | |
3c11ecf4 KH |
4709 | .read_map = mem_cgroup_oom_control_read, |
4710 | .write_u64 = mem_cgroup_oom_control_write, | |
9490ff27 KH |
4711 | .register_event = mem_cgroup_oom_register_event, |
4712 | .unregister_event = mem_cgroup_oom_unregister_event, | |
4713 | .private = MEMFILE_PRIVATE(_OOM_TYPE, OOM_CONTROL), | |
4714 | }, | |
406eb0c9 YH |
4715 | #ifdef CONFIG_NUMA |
4716 | { | |
4717 | .name = "numa_stat", | |
ab215884 | 4718 | .read_seq_string = memcg_numa_stat_show, |
406eb0c9 YH |
4719 | }, |
4720 | #endif | |
c255a458 | 4721 | #ifdef CONFIG_MEMCG_SWAP |
8c7c6e34 KH |
4722 | { |
4723 | .name = "memsw.usage_in_bytes", | |
4724 | .private = MEMFILE_PRIVATE(_MEMSWAP, RES_USAGE), | |
af36f906 | 4725 | .read = mem_cgroup_read, |
9490ff27 KH |
4726 | .register_event = mem_cgroup_usage_register_event, |
4727 | .unregister_event = mem_cgroup_usage_unregister_event, | |
8c7c6e34 KH |
4728 | }, |
4729 | { | |
4730 | .name = "memsw.max_usage_in_bytes", | |
4731 | .private = MEMFILE_PRIVATE(_MEMSWAP, RES_MAX_USAGE), | |
4732 | .trigger = mem_cgroup_reset, | |
af36f906 | 4733 | .read = mem_cgroup_read, |
8c7c6e34 KH |
4734 | }, |
4735 | { | |
4736 | .name = "memsw.limit_in_bytes", | |
4737 | .private = MEMFILE_PRIVATE(_MEMSWAP, RES_LIMIT), | |
4738 | .write_string = mem_cgroup_write, | |
af36f906 | 4739 | .read = mem_cgroup_read, |
8c7c6e34 KH |
4740 | }, |
4741 | { | |
4742 | .name = "memsw.failcnt", | |
4743 | .private = MEMFILE_PRIVATE(_MEMSWAP, RES_FAILCNT), | |
4744 | .trigger = mem_cgroup_reset, | |
af36f906 | 4745 | .read = mem_cgroup_read, |
8c7c6e34 | 4746 | }, |
8c7c6e34 | 4747 | #endif |
6bc10349 | 4748 | { }, /* terminate */ |
af36f906 | 4749 | }; |
8c7c6e34 | 4750 | |
c0ff4b85 | 4751 | static int alloc_mem_cgroup_per_zone_info(struct mem_cgroup *memcg, int node) |
6d12e2d8 KH |
4752 | { |
4753 | struct mem_cgroup_per_node *pn; | |
1ecaab2b | 4754 | struct mem_cgroup_per_zone *mz; |
41e3355d | 4755 | int zone, tmp = node; |
1ecaab2b KH |
4756 | /* |
4757 | * This routine is called against possible nodes. | |
4758 | * But it's BUG to call kmalloc() against offline node. | |
4759 | * | |
4760 | * TODO: this routine can waste much memory for nodes which will | |
4761 | * never be onlined. It's better to use memory hotplug callback | |
4762 | * function. | |
4763 | */ | |
41e3355d KH |
4764 | if (!node_state(node, N_NORMAL_MEMORY)) |
4765 | tmp = -1; | |
17295c88 | 4766 | pn = kzalloc_node(sizeof(*pn), GFP_KERNEL, tmp); |
6d12e2d8 KH |
4767 | if (!pn) |
4768 | return 1; | |
1ecaab2b | 4769 | |
1ecaab2b KH |
4770 | for (zone = 0; zone < MAX_NR_ZONES; zone++) { |
4771 | mz = &pn->zoneinfo[zone]; | |
bea8c150 | 4772 | lruvec_init(&mz->lruvec); |
f64c3f54 | 4773 | mz->usage_in_excess = 0; |
4e416953 | 4774 | mz->on_tree = false; |
d79154bb | 4775 | mz->memcg = memcg; |
1ecaab2b | 4776 | } |
0a619e58 | 4777 | memcg->info.nodeinfo[node] = pn; |
6d12e2d8 KH |
4778 | return 0; |
4779 | } | |
4780 | ||
c0ff4b85 | 4781 | static void free_mem_cgroup_per_zone_info(struct mem_cgroup *memcg, int node) |
1ecaab2b | 4782 | { |
c0ff4b85 | 4783 | kfree(memcg->info.nodeinfo[node]); |
1ecaab2b KH |
4784 | } |
4785 | ||
33327948 KH |
4786 | static struct mem_cgroup *mem_cgroup_alloc(void) |
4787 | { | |
d79154bb | 4788 | struct mem_cgroup *memcg; |
c62b1a3b | 4789 | int size = sizeof(struct mem_cgroup); |
33327948 | 4790 | |
c62b1a3b | 4791 | /* Can be very big if MAX_NUMNODES is very big */ |
c8dad2bb | 4792 | if (size < PAGE_SIZE) |
d79154bb | 4793 | memcg = kzalloc(size, GFP_KERNEL); |
33327948 | 4794 | else |
d79154bb | 4795 | memcg = vzalloc(size); |
33327948 | 4796 | |
d79154bb | 4797 | if (!memcg) |
e7bbcdf3 DC |
4798 | return NULL; |
4799 | ||
d79154bb HD |
4800 | memcg->stat = alloc_percpu(struct mem_cgroup_stat_cpu); |
4801 | if (!memcg->stat) | |
d2e61b8d | 4802 | goto out_free; |
d79154bb HD |
4803 | spin_lock_init(&memcg->pcp_counter_lock); |
4804 | return memcg; | |
d2e61b8d DC |
4805 | |
4806 | out_free: | |
4807 | if (size < PAGE_SIZE) | |
d79154bb | 4808 | kfree(memcg); |
d2e61b8d | 4809 | else |
d79154bb | 4810 | vfree(memcg); |
d2e61b8d | 4811 | return NULL; |
33327948 KH |
4812 | } |
4813 | ||
59927fb9 | 4814 | /* |
3afe36b1 | 4815 | * Helpers for freeing a kmalloc()ed/vzalloc()ed mem_cgroup by RCU, |
59927fb9 HD |
4816 | * but in process context. The work_freeing structure is overlaid |
4817 | * on the rcu_freeing structure, which itself is overlaid on memsw. | |
4818 | */ | |
3afe36b1 | 4819 | static void free_work(struct work_struct *work) |
59927fb9 HD |
4820 | { |
4821 | struct mem_cgroup *memcg; | |
3afe36b1 | 4822 | int size = sizeof(struct mem_cgroup); |
59927fb9 HD |
4823 | |
4824 | memcg = container_of(work, struct mem_cgroup, work_freeing); | |
3f134619 GC |
4825 | /* |
4826 | * We need to make sure that (at least for now), the jump label | |
4827 | * destruction code runs outside of the cgroup lock. This is because | |
4828 | * get_online_cpus(), which is called from the static_branch update, | |
4829 | * can't be called inside the cgroup_lock. cpusets are the ones | |
4830 | * enforcing this dependency, so if they ever change, we might as well. | |
4831 | * | |
4832 | * schedule_work() will guarantee this happens. Be careful if you need | |
4833 | * to move this code around, and make sure it is outside | |
4834 | * the cgroup_lock. | |
4835 | */ | |
4836 | disarm_sock_keys(memcg); | |
3afe36b1 GC |
4837 | if (size < PAGE_SIZE) |
4838 | kfree(memcg); | |
4839 | else | |
4840 | vfree(memcg); | |
59927fb9 | 4841 | } |
3afe36b1 GC |
4842 | |
4843 | static void free_rcu(struct rcu_head *rcu_head) | |
59927fb9 HD |
4844 | { |
4845 | struct mem_cgroup *memcg; | |
4846 | ||
4847 | memcg = container_of(rcu_head, struct mem_cgroup, rcu_freeing); | |
3afe36b1 | 4848 | INIT_WORK(&memcg->work_freeing, free_work); |
59927fb9 HD |
4849 | schedule_work(&memcg->work_freeing); |
4850 | } | |
4851 | ||
8c7c6e34 KH |
4852 | /* |
4853 | * At destroying mem_cgroup, references from swap_cgroup can remain. | |
4854 | * (scanning all at force_empty is too costly...) | |
4855 | * | |
4856 | * Instead of clearing all references at force_empty, we remember | |
4857 | * the number of reference from swap_cgroup and free mem_cgroup when | |
4858 | * it goes down to 0. | |
4859 | * | |
8c7c6e34 KH |
4860 | * Removal of cgroup itself succeeds regardless of refs from swap. |
4861 | */ | |
4862 | ||
c0ff4b85 | 4863 | static void __mem_cgroup_free(struct mem_cgroup *memcg) |
33327948 | 4864 | { |
08e552c6 KH |
4865 | int node; |
4866 | ||
c0ff4b85 R |
4867 | mem_cgroup_remove_from_trees(memcg); |
4868 | free_css_id(&mem_cgroup_subsys, &memcg->css); | |
04046e1a | 4869 | |
3ed28fa1 | 4870 | for_each_node(node) |
c0ff4b85 | 4871 | free_mem_cgroup_per_zone_info(memcg, node); |
08e552c6 | 4872 | |
c0ff4b85 | 4873 | free_percpu(memcg->stat); |
3afe36b1 | 4874 | call_rcu(&memcg->rcu_freeing, free_rcu); |
33327948 KH |
4875 | } |
4876 | ||
c0ff4b85 | 4877 | static void mem_cgroup_get(struct mem_cgroup *memcg) |
8c7c6e34 | 4878 | { |
c0ff4b85 | 4879 | atomic_inc(&memcg->refcnt); |
8c7c6e34 KH |
4880 | } |
4881 | ||
c0ff4b85 | 4882 | static void __mem_cgroup_put(struct mem_cgroup *memcg, int count) |
8c7c6e34 | 4883 | { |
c0ff4b85 R |
4884 | if (atomic_sub_and_test(count, &memcg->refcnt)) { |
4885 | struct mem_cgroup *parent = parent_mem_cgroup(memcg); | |
4886 | __mem_cgroup_free(memcg); | |
7bcc1bb1 DN |
4887 | if (parent) |
4888 | mem_cgroup_put(parent); | |
4889 | } | |
8c7c6e34 KH |
4890 | } |
4891 | ||
c0ff4b85 | 4892 | static void mem_cgroup_put(struct mem_cgroup *memcg) |
483c30b5 | 4893 | { |
c0ff4b85 | 4894 | __mem_cgroup_put(memcg, 1); |
483c30b5 DN |
4895 | } |
4896 | ||
7bcc1bb1 DN |
4897 | /* |
4898 | * Returns the parent mem_cgroup in memcgroup hierarchy with hierarchy enabled. | |
4899 | */ | |
e1aab161 | 4900 | struct mem_cgroup *parent_mem_cgroup(struct mem_cgroup *memcg) |
7bcc1bb1 | 4901 | { |
c0ff4b85 | 4902 | if (!memcg->res.parent) |
7bcc1bb1 | 4903 | return NULL; |
c0ff4b85 | 4904 | return mem_cgroup_from_res_counter(memcg->res.parent, res); |
7bcc1bb1 | 4905 | } |
e1aab161 | 4906 | EXPORT_SYMBOL(parent_mem_cgroup); |
33327948 | 4907 | |
c255a458 | 4908 | #ifdef CONFIG_MEMCG_SWAP |
c077719b KH |
4909 | static void __init enable_swap_cgroup(void) |
4910 | { | |
f8d66542 | 4911 | if (!mem_cgroup_disabled() && really_do_swap_account) |
c077719b KH |
4912 | do_swap_account = 1; |
4913 | } | |
4914 | #else | |
4915 | static void __init enable_swap_cgroup(void) | |
4916 | { | |
4917 | } | |
4918 | #endif | |
4919 | ||
f64c3f54 BS |
4920 | static int mem_cgroup_soft_limit_tree_init(void) |
4921 | { | |
4922 | struct mem_cgroup_tree_per_node *rtpn; | |
4923 | struct mem_cgroup_tree_per_zone *rtpz; | |
4924 | int tmp, node, zone; | |
4925 | ||
3ed28fa1 | 4926 | for_each_node(node) { |
f64c3f54 BS |
4927 | tmp = node; |
4928 | if (!node_state(node, N_NORMAL_MEMORY)) | |
4929 | tmp = -1; | |
4930 | rtpn = kzalloc_node(sizeof(*rtpn), GFP_KERNEL, tmp); | |
4931 | if (!rtpn) | |
c3cecc68 | 4932 | goto err_cleanup; |
f64c3f54 BS |
4933 | |
4934 | soft_limit_tree.rb_tree_per_node[node] = rtpn; | |
4935 | ||
4936 | for (zone = 0; zone < MAX_NR_ZONES; zone++) { | |
4937 | rtpz = &rtpn->rb_tree_per_zone[zone]; | |
4938 | rtpz->rb_root = RB_ROOT; | |
4939 | spin_lock_init(&rtpz->lock); | |
4940 | } | |
4941 | } | |
4942 | return 0; | |
c3cecc68 MH |
4943 | |
4944 | err_cleanup: | |
3ed28fa1 | 4945 | for_each_node(node) { |
c3cecc68 MH |
4946 | if (!soft_limit_tree.rb_tree_per_node[node]) |
4947 | break; | |
4948 | kfree(soft_limit_tree.rb_tree_per_node[node]); | |
4949 | soft_limit_tree.rb_tree_per_node[node] = NULL; | |
4950 | } | |
4951 | return 1; | |
4952 | ||
f64c3f54 BS |
4953 | } |
4954 | ||
0eb253e2 | 4955 | static struct cgroup_subsys_state * __ref |
761b3ef5 | 4956 | mem_cgroup_create(struct cgroup *cont) |
8cdea7c0 | 4957 | { |
c0ff4b85 | 4958 | struct mem_cgroup *memcg, *parent; |
04046e1a | 4959 | long error = -ENOMEM; |
6d12e2d8 | 4960 | int node; |
8cdea7c0 | 4961 | |
c0ff4b85 R |
4962 | memcg = mem_cgroup_alloc(); |
4963 | if (!memcg) | |
04046e1a | 4964 | return ERR_PTR(error); |
78fb7466 | 4965 | |
3ed28fa1 | 4966 | for_each_node(node) |
c0ff4b85 | 4967 | if (alloc_mem_cgroup_per_zone_info(memcg, node)) |
6d12e2d8 | 4968 | goto free_out; |
f64c3f54 | 4969 | |
c077719b | 4970 | /* root ? */ |
28dbc4b6 | 4971 | if (cont->parent == NULL) { |
cdec2e42 | 4972 | int cpu; |
c077719b | 4973 | enable_swap_cgroup(); |
28dbc4b6 | 4974 | parent = NULL; |
f64c3f54 BS |
4975 | if (mem_cgroup_soft_limit_tree_init()) |
4976 | goto free_out; | |
a41c58a6 | 4977 | root_mem_cgroup = memcg; |
cdec2e42 KH |
4978 | for_each_possible_cpu(cpu) { |
4979 | struct memcg_stock_pcp *stock = | |
4980 | &per_cpu(memcg_stock, cpu); | |
4981 | INIT_WORK(&stock->work, drain_local_stock); | |
4982 | } | |
711d3d2c | 4983 | hotcpu_notifier(memcg_cpu_hotplug_callback, 0); |
18f59ea7 | 4984 | } else { |
28dbc4b6 | 4985 | parent = mem_cgroup_from_cont(cont->parent); |
c0ff4b85 R |
4986 | memcg->use_hierarchy = parent->use_hierarchy; |
4987 | memcg->oom_kill_disable = parent->oom_kill_disable; | |
18f59ea7 | 4988 | } |
28dbc4b6 | 4989 | |
18f59ea7 | 4990 | if (parent && parent->use_hierarchy) { |
c0ff4b85 R |
4991 | res_counter_init(&memcg->res, &parent->res); |
4992 | res_counter_init(&memcg->memsw, &parent->memsw); | |
7bcc1bb1 DN |
4993 | /* |
4994 | * We increment refcnt of the parent to ensure that we can | |
4995 | * safely access it on res_counter_charge/uncharge. | |
4996 | * This refcnt will be decremented when freeing this | |
4997 | * mem_cgroup(see mem_cgroup_put). | |
4998 | */ | |
4999 | mem_cgroup_get(parent); | |
18f59ea7 | 5000 | } else { |
c0ff4b85 R |
5001 | res_counter_init(&memcg->res, NULL); |
5002 | res_counter_init(&memcg->memsw, NULL); | |
8c7f6edb TH |
5003 | /* |
5004 | * Deeper hierachy with use_hierarchy == false doesn't make | |
5005 | * much sense so let cgroup subsystem know about this | |
5006 | * unfortunate state in our controller. | |
5007 | */ | |
5008 | if (parent && parent != root_mem_cgroup) | |
5009 | mem_cgroup_subsys.broken_hierarchy = true; | |
18f59ea7 | 5010 | } |
c0ff4b85 R |
5011 | memcg->last_scanned_node = MAX_NUMNODES; |
5012 | INIT_LIST_HEAD(&memcg->oom_notify); | |
6d61ef40 | 5013 | |
a7885eb8 | 5014 | if (parent) |
c0ff4b85 R |
5015 | memcg->swappiness = mem_cgroup_swappiness(parent); |
5016 | atomic_set(&memcg->refcnt, 1); | |
5017 | memcg->move_charge_at_immigrate = 0; | |
5018 | mutex_init(&memcg->thresholds_lock); | |
312734c0 | 5019 | spin_lock_init(&memcg->move_lock); |
cbe128e3 GC |
5020 | |
5021 | error = memcg_init_kmem(memcg, &mem_cgroup_subsys); | |
5022 | if (error) { | |
5023 | /* | |
5024 | * We call put now because our (and parent's) refcnts | |
5025 | * are already in place. mem_cgroup_put() will internally | |
5026 | * call __mem_cgroup_free, so return directly | |
5027 | */ | |
5028 | mem_cgroup_put(memcg); | |
5029 | return ERR_PTR(error); | |
5030 | } | |
c0ff4b85 | 5031 | return &memcg->css; |
6d12e2d8 | 5032 | free_out: |
c0ff4b85 | 5033 | __mem_cgroup_free(memcg); |
04046e1a | 5034 | return ERR_PTR(error); |
8cdea7c0 BS |
5035 | } |
5036 | ||
761b3ef5 | 5037 | static int mem_cgroup_pre_destroy(struct cgroup *cont) |
df878fb0 | 5038 | { |
c0ff4b85 | 5039 | struct mem_cgroup *memcg = mem_cgroup_from_cont(cont); |
ec64f515 | 5040 | |
c0ff4b85 | 5041 | return mem_cgroup_force_empty(memcg, false); |
df878fb0 KH |
5042 | } |
5043 | ||
761b3ef5 | 5044 | static void mem_cgroup_destroy(struct cgroup *cont) |
8cdea7c0 | 5045 | { |
c0ff4b85 | 5046 | struct mem_cgroup *memcg = mem_cgroup_from_cont(cont); |
c268e994 | 5047 | |
1d62e436 | 5048 | kmem_cgroup_destroy(memcg); |
d1a4c0b3 | 5049 | |
c0ff4b85 | 5050 | mem_cgroup_put(memcg); |
8cdea7c0 BS |
5051 | } |
5052 | ||
02491447 | 5053 | #ifdef CONFIG_MMU |
7dc74be0 | 5054 | /* Handlers for move charge at task migration. */ |
854ffa8d DN |
5055 | #define PRECHARGE_COUNT_AT_ONCE 256 |
5056 | static int mem_cgroup_do_precharge(unsigned long count) | |
7dc74be0 | 5057 | { |
854ffa8d DN |
5058 | int ret = 0; |
5059 | int batch_count = PRECHARGE_COUNT_AT_ONCE; | |
c0ff4b85 | 5060 | struct mem_cgroup *memcg = mc.to; |
4ffef5fe | 5061 | |
c0ff4b85 | 5062 | if (mem_cgroup_is_root(memcg)) { |
854ffa8d DN |
5063 | mc.precharge += count; |
5064 | /* we don't need css_get for root */ | |
5065 | return ret; | |
5066 | } | |
5067 | /* try to charge at once */ | |
5068 | if (count > 1) { | |
5069 | struct res_counter *dummy; | |
5070 | /* | |
c0ff4b85 | 5071 | * "memcg" cannot be under rmdir() because we've already checked |
854ffa8d DN |
5072 | * by cgroup_lock_live_cgroup() that it is not removed and we |
5073 | * are still under the same cgroup_mutex. So we can postpone | |
5074 | * css_get(). | |
5075 | */ | |
c0ff4b85 | 5076 | if (res_counter_charge(&memcg->res, PAGE_SIZE * count, &dummy)) |
854ffa8d | 5077 | goto one_by_one; |
c0ff4b85 | 5078 | if (do_swap_account && res_counter_charge(&memcg->memsw, |
854ffa8d | 5079 | PAGE_SIZE * count, &dummy)) { |
c0ff4b85 | 5080 | res_counter_uncharge(&memcg->res, PAGE_SIZE * count); |
854ffa8d DN |
5081 | goto one_by_one; |
5082 | } | |
5083 | mc.precharge += count; | |
854ffa8d DN |
5084 | return ret; |
5085 | } | |
5086 | one_by_one: | |
5087 | /* fall back to one by one charge */ | |
5088 | while (count--) { | |
5089 | if (signal_pending(current)) { | |
5090 | ret = -EINTR; | |
5091 | break; | |
5092 | } | |
5093 | if (!batch_count--) { | |
5094 | batch_count = PRECHARGE_COUNT_AT_ONCE; | |
5095 | cond_resched(); | |
5096 | } | |
c0ff4b85 R |
5097 | ret = __mem_cgroup_try_charge(NULL, |
5098 | GFP_KERNEL, 1, &memcg, false); | |
38c5d72f | 5099 | if (ret) |
854ffa8d | 5100 | /* mem_cgroup_clear_mc() will do uncharge later */ |
38c5d72f | 5101 | return ret; |
854ffa8d DN |
5102 | mc.precharge++; |
5103 | } | |
4ffef5fe DN |
5104 | return ret; |
5105 | } | |
5106 | ||
5107 | /** | |
8d32ff84 | 5108 | * get_mctgt_type - get target type of moving charge |
4ffef5fe DN |
5109 | * @vma: the vma the pte to be checked belongs |
5110 | * @addr: the address corresponding to the pte to be checked | |
5111 | * @ptent: the pte to be checked | |
02491447 | 5112 | * @target: the pointer the target page or swap ent will be stored(can be NULL) |
4ffef5fe DN |
5113 | * |
5114 | * Returns | |
5115 | * 0(MC_TARGET_NONE): if the pte is not a target for move charge. | |
5116 | * 1(MC_TARGET_PAGE): if the page corresponding to this pte is a target for | |
5117 | * move charge. if @target is not NULL, the page is stored in target->page | |
5118 | * with extra refcnt got(Callers should handle it). | |
02491447 DN |
5119 | * 2(MC_TARGET_SWAP): if the swap entry corresponding to this pte is a |
5120 | * target for charge migration. if @target is not NULL, the entry is stored | |
5121 | * in target->ent. | |
4ffef5fe DN |
5122 | * |
5123 | * Called with pte lock held. | |
5124 | */ | |
4ffef5fe DN |
5125 | union mc_target { |
5126 | struct page *page; | |
02491447 | 5127 | swp_entry_t ent; |
4ffef5fe DN |
5128 | }; |
5129 | ||
4ffef5fe | 5130 | enum mc_target_type { |
8d32ff84 | 5131 | MC_TARGET_NONE = 0, |
4ffef5fe | 5132 | MC_TARGET_PAGE, |
02491447 | 5133 | MC_TARGET_SWAP, |
4ffef5fe DN |
5134 | }; |
5135 | ||
90254a65 DN |
5136 | static struct page *mc_handle_present_pte(struct vm_area_struct *vma, |
5137 | unsigned long addr, pte_t ptent) | |
4ffef5fe | 5138 | { |
90254a65 | 5139 | struct page *page = vm_normal_page(vma, addr, ptent); |
4ffef5fe | 5140 | |
90254a65 DN |
5141 | if (!page || !page_mapped(page)) |
5142 | return NULL; | |
5143 | if (PageAnon(page)) { | |
5144 | /* we don't move shared anon */ | |
4b91355e | 5145 | if (!move_anon()) |
90254a65 | 5146 | return NULL; |
87946a72 DN |
5147 | } else if (!move_file()) |
5148 | /* we ignore mapcount for file pages */ | |
90254a65 DN |
5149 | return NULL; |
5150 | if (!get_page_unless_zero(page)) | |
5151 | return NULL; | |
5152 | ||
5153 | return page; | |
5154 | } | |
5155 | ||
4b91355e | 5156 | #ifdef CONFIG_SWAP |
90254a65 DN |
5157 | static struct page *mc_handle_swap_pte(struct vm_area_struct *vma, |
5158 | unsigned long addr, pte_t ptent, swp_entry_t *entry) | |
5159 | { | |
90254a65 DN |
5160 | struct page *page = NULL; |
5161 | swp_entry_t ent = pte_to_swp_entry(ptent); | |
5162 | ||
5163 | if (!move_anon() || non_swap_entry(ent)) | |
5164 | return NULL; | |
4b91355e KH |
5165 | /* |
5166 | * Because lookup_swap_cache() updates some statistics counter, | |
5167 | * we call find_get_page() with swapper_space directly. | |
5168 | */ | |
5169 | page = find_get_page(&swapper_space, ent.val); | |
90254a65 DN |
5170 | if (do_swap_account) |
5171 | entry->val = ent.val; | |
5172 | ||
5173 | return page; | |
5174 | } | |
4b91355e KH |
5175 | #else |
5176 | static struct page *mc_handle_swap_pte(struct vm_area_struct *vma, | |
5177 | unsigned long addr, pte_t ptent, swp_entry_t *entry) | |
5178 | { | |
5179 | return NULL; | |
5180 | } | |
5181 | #endif | |
90254a65 | 5182 | |
87946a72 DN |
5183 | static struct page *mc_handle_file_pte(struct vm_area_struct *vma, |
5184 | unsigned long addr, pte_t ptent, swp_entry_t *entry) | |
5185 | { | |
5186 | struct page *page = NULL; | |
87946a72 DN |
5187 | struct address_space *mapping; |
5188 | pgoff_t pgoff; | |
5189 | ||
5190 | if (!vma->vm_file) /* anonymous vma */ | |
5191 | return NULL; | |
5192 | if (!move_file()) | |
5193 | return NULL; | |
5194 | ||
87946a72 DN |
5195 | mapping = vma->vm_file->f_mapping; |
5196 | if (pte_none(ptent)) | |
5197 | pgoff = linear_page_index(vma, addr); | |
5198 | else /* pte_file(ptent) is true */ | |
5199 | pgoff = pte_to_pgoff(ptent); | |
5200 | ||
5201 | /* page is moved even if it's not RSS of this task(page-faulted). */ | |
aa3b1895 HD |
5202 | page = find_get_page(mapping, pgoff); |
5203 | ||
5204 | #ifdef CONFIG_SWAP | |
5205 | /* shmem/tmpfs may report page out on swap: account for that too. */ | |
5206 | if (radix_tree_exceptional_entry(page)) { | |
5207 | swp_entry_t swap = radix_to_swp_entry(page); | |
87946a72 | 5208 | if (do_swap_account) |
aa3b1895 HD |
5209 | *entry = swap; |
5210 | page = find_get_page(&swapper_space, swap.val); | |
87946a72 | 5211 | } |
aa3b1895 | 5212 | #endif |
87946a72 DN |
5213 | return page; |
5214 | } | |
5215 | ||
8d32ff84 | 5216 | static enum mc_target_type get_mctgt_type(struct vm_area_struct *vma, |
90254a65 DN |
5217 | unsigned long addr, pte_t ptent, union mc_target *target) |
5218 | { | |
5219 | struct page *page = NULL; | |
5220 | struct page_cgroup *pc; | |
8d32ff84 | 5221 | enum mc_target_type ret = MC_TARGET_NONE; |
90254a65 DN |
5222 | swp_entry_t ent = { .val = 0 }; |
5223 | ||
5224 | if (pte_present(ptent)) | |
5225 | page = mc_handle_present_pte(vma, addr, ptent); | |
5226 | else if (is_swap_pte(ptent)) | |
5227 | page = mc_handle_swap_pte(vma, addr, ptent, &ent); | |
87946a72 DN |
5228 | else if (pte_none(ptent) || pte_file(ptent)) |
5229 | page = mc_handle_file_pte(vma, addr, ptent, &ent); | |
90254a65 DN |
5230 | |
5231 | if (!page && !ent.val) | |
8d32ff84 | 5232 | return ret; |
02491447 DN |
5233 | if (page) { |
5234 | pc = lookup_page_cgroup(page); | |
5235 | /* | |
5236 | * Do only loose check w/o page_cgroup lock. | |
5237 | * mem_cgroup_move_account() checks the pc is valid or not under | |
5238 | * the lock. | |
5239 | */ | |
5240 | if (PageCgroupUsed(pc) && pc->mem_cgroup == mc.from) { | |
5241 | ret = MC_TARGET_PAGE; | |
5242 | if (target) | |
5243 | target->page = page; | |
5244 | } | |
5245 | if (!ret || !target) | |
5246 | put_page(page); | |
5247 | } | |
90254a65 DN |
5248 | /* There is a swap entry and a page doesn't exist or isn't charged */ |
5249 | if (ent.val && !ret && | |
9fb4b7cc | 5250 | css_id(&mc.from->css) == lookup_swap_cgroup_id(ent)) { |
7f0f1546 KH |
5251 | ret = MC_TARGET_SWAP; |
5252 | if (target) | |
5253 | target->ent = ent; | |
4ffef5fe | 5254 | } |
4ffef5fe DN |
5255 | return ret; |
5256 | } | |
5257 | ||
12724850 NH |
5258 | #ifdef CONFIG_TRANSPARENT_HUGEPAGE |
5259 | /* | |
5260 | * We don't consider swapping or file mapped pages because THP does not | |
5261 | * support them for now. | |
5262 | * Caller should make sure that pmd_trans_huge(pmd) is true. | |
5263 | */ | |
5264 | static enum mc_target_type get_mctgt_type_thp(struct vm_area_struct *vma, | |
5265 | unsigned long addr, pmd_t pmd, union mc_target *target) | |
5266 | { | |
5267 | struct page *page = NULL; | |
5268 | struct page_cgroup *pc; | |
5269 | enum mc_target_type ret = MC_TARGET_NONE; | |
5270 | ||
5271 | page = pmd_page(pmd); | |
5272 | VM_BUG_ON(!page || !PageHead(page)); | |
5273 | if (!move_anon()) | |
5274 | return ret; | |
5275 | pc = lookup_page_cgroup(page); | |
5276 | if (PageCgroupUsed(pc) && pc->mem_cgroup == mc.from) { | |
5277 | ret = MC_TARGET_PAGE; | |
5278 | if (target) { | |
5279 | get_page(page); | |
5280 | target->page = page; | |
5281 | } | |
5282 | } | |
5283 | return ret; | |
5284 | } | |
5285 | #else | |
5286 | static inline enum mc_target_type get_mctgt_type_thp(struct vm_area_struct *vma, | |
5287 | unsigned long addr, pmd_t pmd, union mc_target *target) | |
5288 | { | |
5289 | return MC_TARGET_NONE; | |
5290 | } | |
5291 | #endif | |
5292 | ||
4ffef5fe DN |
5293 | static int mem_cgroup_count_precharge_pte_range(pmd_t *pmd, |
5294 | unsigned long addr, unsigned long end, | |
5295 | struct mm_walk *walk) | |
5296 | { | |
5297 | struct vm_area_struct *vma = walk->private; | |
5298 | pte_t *pte; | |
5299 | spinlock_t *ptl; | |
5300 | ||
12724850 NH |
5301 | if (pmd_trans_huge_lock(pmd, vma) == 1) { |
5302 | if (get_mctgt_type_thp(vma, addr, *pmd, NULL) == MC_TARGET_PAGE) | |
5303 | mc.precharge += HPAGE_PMD_NR; | |
5304 | spin_unlock(&vma->vm_mm->page_table_lock); | |
1a5a9906 | 5305 | return 0; |
12724850 | 5306 | } |
03319327 | 5307 | |
45f83cef AA |
5308 | if (pmd_trans_unstable(pmd)) |
5309 | return 0; | |
4ffef5fe DN |
5310 | pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl); |
5311 | for (; addr != end; pte++, addr += PAGE_SIZE) | |
8d32ff84 | 5312 | if (get_mctgt_type(vma, addr, *pte, NULL)) |
4ffef5fe DN |
5313 | mc.precharge++; /* increment precharge temporarily */ |
5314 | pte_unmap_unlock(pte - 1, ptl); | |
5315 | cond_resched(); | |
5316 | ||
7dc74be0 DN |
5317 | return 0; |
5318 | } | |
5319 | ||
4ffef5fe DN |
5320 | static unsigned long mem_cgroup_count_precharge(struct mm_struct *mm) |
5321 | { | |
5322 | unsigned long precharge; | |
5323 | struct vm_area_struct *vma; | |
5324 | ||
dfe076b0 | 5325 | down_read(&mm->mmap_sem); |
4ffef5fe DN |
5326 | for (vma = mm->mmap; vma; vma = vma->vm_next) { |
5327 | struct mm_walk mem_cgroup_count_precharge_walk = { | |
5328 | .pmd_entry = mem_cgroup_count_precharge_pte_range, | |
5329 | .mm = mm, | |
5330 | .private = vma, | |
5331 | }; | |
5332 | if (is_vm_hugetlb_page(vma)) | |
5333 | continue; | |
4ffef5fe DN |
5334 | walk_page_range(vma->vm_start, vma->vm_end, |
5335 | &mem_cgroup_count_precharge_walk); | |
5336 | } | |
dfe076b0 | 5337 | up_read(&mm->mmap_sem); |
4ffef5fe DN |
5338 | |
5339 | precharge = mc.precharge; | |
5340 | mc.precharge = 0; | |
5341 | ||
5342 | return precharge; | |
5343 | } | |
5344 | ||
4ffef5fe DN |
5345 | static int mem_cgroup_precharge_mc(struct mm_struct *mm) |
5346 | { | |
dfe076b0 DN |
5347 | unsigned long precharge = mem_cgroup_count_precharge(mm); |
5348 | ||
5349 | VM_BUG_ON(mc.moving_task); | |
5350 | mc.moving_task = current; | |
5351 | return mem_cgroup_do_precharge(precharge); | |
4ffef5fe DN |
5352 | } |
5353 | ||
dfe076b0 DN |
5354 | /* cancels all extra charges on mc.from and mc.to, and wakes up all waiters. */ |
5355 | static void __mem_cgroup_clear_mc(void) | |
4ffef5fe | 5356 | { |
2bd9bb20 KH |
5357 | struct mem_cgroup *from = mc.from; |
5358 | struct mem_cgroup *to = mc.to; | |
5359 | ||
4ffef5fe | 5360 | /* we must uncharge all the leftover precharges from mc.to */ |
854ffa8d DN |
5361 | if (mc.precharge) { |
5362 | __mem_cgroup_cancel_charge(mc.to, mc.precharge); | |
5363 | mc.precharge = 0; | |
5364 | } | |
5365 | /* | |
5366 | * we didn't uncharge from mc.from at mem_cgroup_move_account(), so | |
5367 | * we must uncharge here. | |
5368 | */ | |
5369 | if (mc.moved_charge) { | |
5370 | __mem_cgroup_cancel_charge(mc.from, mc.moved_charge); | |
5371 | mc.moved_charge = 0; | |
4ffef5fe | 5372 | } |
483c30b5 DN |
5373 | /* we must fixup refcnts and charges */ |
5374 | if (mc.moved_swap) { | |
483c30b5 DN |
5375 | /* uncharge swap account from the old cgroup */ |
5376 | if (!mem_cgroup_is_root(mc.from)) | |
5377 | res_counter_uncharge(&mc.from->memsw, | |
5378 | PAGE_SIZE * mc.moved_swap); | |
5379 | __mem_cgroup_put(mc.from, mc.moved_swap); | |
5380 | ||
5381 | if (!mem_cgroup_is_root(mc.to)) { | |
5382 | /* | |
5383 | * we charged both to->res and to->memsw, so we should | |
5384 | * uncharge to->res. | |
5385 | */ | |
5386 | res_counter_uncharge(&mc.to->res, | |
5387 | PAGE_SIZE * mc.moved_swap); | |
483c30b5 DN |
5388 | } |
5389 | /* we've already done mem_cgroup_get(mc.to) */ | |
483c30b5 DN |
5390 | mc.moved_swap = 0; |
5391 | } | |
dfe076b0 DN |
5392 | memcg_oom_recover(from); |
5393 | memcg_oom_recover(to); | |
5394 | wake_up_all(&mc.waitq); | |
5395 | } | |
5396 | ||
5397 | static void mem_cgroup_clear_mc(void) | |
5398 | { | |
5399 | struct mem_cgroup *from = mc.from; | |
5400 | ||
5401 | /* | |
5402 | * we must clear moving_task before waking up waiters at the end of | |
5403 | * task migration. | |
5404 | */ | |
5405 | mc.moving_task = NULL; | |
5406 | __mem_cgroup_clear_mc(); | |
2bd9bb20 | 5407 | spin_lock(&mc.lock); |
4ffef5fe DN |
5408 | mc.from = NULL; |
5409 | mc.to = NULL; | |
2bd9bb20 | 5410 | spin_unlock(&mc.lock); |
32047e2a | 5411 | mem_cgroup_end_move(from); |
4ffef5fe DN |
5412 | } |
5413 | ||
761b3ef5 LZ |
5414 | static int mem_cgroup_can_attach(struct cgroup *cgroup, |
5415 | struct cgroup_taskset *tset) | |
7dc74be0 | 5416 | { |
2f7ee569 | 5417 | struct task_struct *p = cgroup_taskset_first(tset); |
7dc74be0 | 5418 | int ret = 0; |
c0ff4b85 | 5419 | struct mem_cgroup *memcg = mem_cgroup_from_cont(cgroup); |
7dc74be0 | 5420 | |
c0ff4b85 | 5421 | if (memcg->move_charge_at_immigrate) { |
7dc74be0 DN |
5422 | struct mm_struct *mm; |
5423 | struct mem_cgroup *from = mem_cgroup_from_task(p); | |
5424 | ||
c0ff4b85 | 5425 | VM_BUG_ON(from == memcg); |
7dc74be0 DN |
5426 | |
5427 | mm = get_task_mm(p); | |
5428 | if (!mm) | |
5429 | return 0; | |
7dc74be0 | 5430 | /* We move charges only when we move a owner of the mm */ |
4ffef5fe DN |
5431 | if (mm->owner == p) { |
5432 | VM_BUG_ON(mc.from); | |
5433 | VM_BUG_ON(mc.to); | |
5434 | VM_BUG_ON(mc.precharge); | |
854ffa8d | 5435 | VM_BUG_ON(mc.moved_charge); |
483c30b5 | 5436 | VM_BUG_ON(mc.moved_swap); |
32047e2a | 5437 | mem_cgroup_start_move(from); |
2bd9bb20 | 5438 | spin_lock(&mc.lock); |
4ffef5fe | 5439 | mc.from = from; |
c0ff4b85 | 5440 | mc.to = memcg; |
2bd9bb20 | 5441 | spin_unlock(&mc.lock); |
dfe076b0 | 5442 | /* We set mc.moving_task later */ |
4ffef5fe DN |
5443 | |
5444 | ret = mem_cgroup_precharge_mc(mm); | |
5445 | if (ret) | |
5446 | mem_cgroup_clear_mc(); | |
dfe076b0 DN |
5447 | } |
5448 | mmput(mm); | |
7dc74be0 DN |
5449 | } |
5450 | return ret; | |
5451 | } | |
5452 | ||
761b3ef5 LZ |
5453 | static void mem_cgroup_cancel_attach(struct cgroup *cgroup, |
5454 | struct cgroup_taskset *tset) | |
7dc74be0 | 5455 | { |
4ffef5fe | 5456 | mem_cgroup_clear_mc(); |
7dc74be0 DN |
5457 | } |
5458 | ||
4ffef5fe DN |
5459 | static int mem_cgroup_move_charge_pte_range(pmd_t *pmd, |
5460 | unsigned long addr, unsigned long end, | |
5461 | struct mm_walk *walk) | |
7dc74be0 | 5462 | { |
4ffef5fe DN |
5463 | int ret = 0; |
5464 | struct vm_area_struct *vma = walk->private; | |
5465 | pte_t *pte; | |
5466 | spinlock_t *ptl; | |
12724850 NH |
5467 | enum mc_target_type target_type; |
5468 | union mc_target target; | |
5469 | struct page *page; | |
5470 | struct page_cgroup *pc; | |
4ffef5fe | 5471 | |
12724850 NH |
5472 | /* |
5473 | * We don't take compound_lock() here but no race with splitting thp | |
5474 | * happens because: | |
5475 | * - if pmd_trans_huge_lock() returns 1, the relevant thp is not | |
5476 | * under splitting, which means there's no concurrent thp split, | |
5477 | * - if another thread runs into split_huge_page() just after we | |
5478 | * entered this if-block, the thread must wait for page table lock | |
5479 | * to be unlocked in __split_huge_page_splitting(), where the main | |
5480 | * part of thp split is not executed yet. | |
5481 | */ | |
5482 | if (pmd_trans_huge_lock(pmd, vma) == 1) { | |
62ade86a | 5483 | if (mc.precharge < HPAGE_PMD_NR) { |
12724850 NH |
5484 | spin_unlock(&vma->vm_mm->page_table_lock); |
5485 | return 0; | |
5486 | } | |
5487 | target_type = get_mctgt_type_thp(vma, addr, *pmd, &target); | |
5488 | if (target_type == MC_TARGET_PAGE) { | |
5489 | page = target.page; | |
5490 | if (!isolate_lru_page(page)) { | |
5491 | pc = lookup_page_cgroup(page); | |
5492 | if (!mem_cgroup_move_account(page, HPAGE_PMD_NR, | |
2f3479b1 | 5493 | pc, mc.from, mc.to)) { |
12724850 NH |
5494 | mc.precharge -= HPAGE_PMD_NR; |
5495 | mc.moved_charge += HPAGE_PMD_NR; | |
5496 | } | |
5497 | putback_lru_page(page); | |
5498 | } | |
5499 | put_page(page); | |
5500 | } | |
5501 | spin_unlock(&vma->vm_mm->page_table_lock); | |
1a5a9906 | 5502 | return 0; |
12724850 NH |
5503 | } |
5504 | ||
45f83cef AA |
5505 | if (pmd_trans_unstable(pmd)) |
5506 | return 0; | |
4ffef5fe DN |
5507 | retry: |
5508 | pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl); | |
5509 | for (; addr != end; addr += PAGE_SIZE) { | |
5510 | pte_t ptent = *(pte++); | |
02491447 | 5511 | swp_entry_t ent; |
4ffef5fe DN |
5512 | |
5513 | if (!mc.precharge) | |
5514 | break; | |
5515 | ||
8d32ff84 | 5516 | switch (get_mctgt_type(vma, addr, ptent, &target)) { |
4ffef5fe DN |
5517 | case MC_TARGET_PAGE: |
5518 | page = target.page; | |
5519 | if (isolate_lru_page(page)) | |
5520 | goto put; | |
5521 | pc = lookup_page_cgroup(page); | |
7ec99d62 | 5522 | if (!mem_cgroup_move_account(page, 1, pc, |
2f3479b1 | 5523 | mc.from, mc.to)) { |
4ffef5fe | 5524 | mc.precharge--; |
854ffa8d DN |
5525 | /* we uncharge from mc.from later. */ |
5526 | mc.moved_charge++; | |
4ffef5fe DN |
5527 | } |
5528 | putback_lru_page(page); | |
8d32ff84 | 5529 | put: /* get_mctgt_type() gets the page */ |
4ffef5fe DN |
5530 | put_page(page); |
5531 | break; | |
02491447 DN |
5532 | case MC_TARGET_SWAP: |
5533 | ent = target.ent; | |
e91cbb42 | 5534 | if (!mem_cgroup_move_swap_account(ent, mc.from, mc.to)) { |
02491447 | 5535 | mc.precharge--; |
483c30b5 DN |
5536 | /* we fixup refcnts and charges later. */ |
5537 | mc.moved_swap++; | |
5538 | } | |
02491447 | 5539 | break; |
4ffef5fe DN |
5540 | default: |
5541 | break; | |
5542 | } | |
5543 | } | |
5544 | pte_unmap_unlock(pte - 1, ptl); | |
5545 | cond_resched(); | |
5546 | ||
5547 | if (addr != end) { | |
5548 | /* | |
5549 | * We have consumed all precharges we got in can_attach(). | |
5550 | * We try charge one by one, but don't do any additional | |
5551 | * charges to mc.to if we have failed in charge once in attach() | |
5552 | * phase. | |
5553 | */ | |
854ffa8d | 5554 | ret = mem_cgroup_do_precharge(1); |
4ffef5fe DN |
5555 | if (!ret) |
5556 | goto retry; | |
5557 | } | |
5558 | ||
5559 | return ret; | |
5560 | } | |
5561 | ||
5562 | static void mem_cgroup_move_charge(struct mm_struct *mm) | |
5563 | { | |
5564 | struct vm_area_struct *vma; | |
5565 | ||
5566 | lru_add_drain_all(); | |
dfe076b0 DN |
5567 | retry: |
5568 | if (unlikely(!down_read_trylock(&mm->mmap_sem))) { | |
5569 | /* | |
5570 | * Someone who are holding the mmap_sem might be waiting in | |
5571 | * waitq. So we cancel all extra charges, wake up all waiters, | |
5572 | * and retry. Because we cancel precharges, we might not be able | |
5573 | * to move enough charges, but moving charge is a best-effort | |
5574 | * feature anyway, so it wouldn't be a big problem. | |
5575 | */ | |
5576 | __mem_cgroup_clear_mc(); | |
5577 | cond_resched(); | |
5578 | goto retry; | |
5579 | } | |
4ffef5fe DN |
5580 | for (vma = mm->mmap; vma; vma = vma->vm_next) { |
5581 | int ret; | |
5582 | struct mm_walk mem_cgroup_move_charge_walk = { | |
5583 | .pmd_entry = mem_cgroup_move_charge_pte_range, | |
5584 | .mm = mm, | |
5585 | .private = vma, | |
5586 | }; | |
5587 | if (is_vm_hugetlb_page(vma)) | |
5588 | continue; | |
4ffef5fe DN |
5589 | ret = walk_page_range(vma->vm_start, vma->vm_end, |
5590 | &mem_cgroup_move_charge_walk); | |
5591 | if (ret) | |
5592 | /* | |
5593 | * means we have consumed all precharges and failed in | |
5594 | * doing additional charge. Just abandon here. | |
5595 | */ | |
5596 | break; | |
5597 | } | |
dfe076b0 | 5598 | up_read(&mm->mmap_sem); |
7dc74be0 DN |
5599 | } |
5600 | ||
761b3ef5 LZ |
5601 | static void mem_cgroup_move_task(struct cgroup *cont, |
5602 | struct cgroup_taskset *tset) | |
67e465a7 | 5603 | { |
2f7ee569 | 5604 | struct task_struct *p = cgroup_taskset_first(tset); |
a433658c | 5605 | struct mm_struct *mm = get_task_mm(p); |
dfe076b0 | 5606 | |
dfe076b0 | 5607 | if (mm) { |
a433658c KM |
5608 | if (mc.to) |
5609 | mem_cgroup_move_charge(mm); | |
dfe076b0 DN |
5610 | mmput(mm); |
5611 | } | |
a433658c KM |
5612 | if (mc.to) |
5613 | mem_cgroup_clear_mc(); | |
67e465a7 | 5614 | } |
5cfb80a7 | 5615 | #else /* !CONFIG_MMU */ |
761b3ef5 LZ |
5616 | static int mem_cgroup_can_attach(struct cgroup *cgroup, |
5617 | struct cgroup_taskset *tset) | |
5cfb80a7 DN |
5618 | { |
5619 | return 0; | |
5620 | } | |
761b3ef5 LZ |
5621 | static void mem_cgroup_cancel_attach(struct cgroup *cgroup, |
5622 | struct cgroup_taskset *tset) | |
5cfb80a7 DN |
5623 | { |
5624 | } | |
761b3ef5 LZ |
5625 | static void mem_cgroup_move_task(struct cgroup *cont, |
5626 | struct cgroup_taskset *tset) | |
5cfb80a7 DN |
5627 | { |
5628 | } | |
5629 | #endif | |
67e465a7 | 5630 | |
8cdea7c0 BS |
5631 | struct cgroup_subsys mem_cgroup_subsys = { |
5632 | .name = "memory", | |
5633 | .subsys_id = mem_cgroup_subsys_id, | |
5634 | .create = mem_cgroup_create, | |
df878fb0 | 5635 | .pre_destroy = mem_cgroup_pre_destroy, |
8cdea7c0 | 5636 | .destroy = mem_cgroup_destroy, |
7dc74be0 DN |
5637 | .can_attach = mem_cgroup_can_attach, |
5638 | .cancel_attach = mem_cgroup_cancel_attach, | |
67e465a7 | 5639 | .attach = mem_cgroup_move_task, |
6bc10349 | 5640 | .base_cftypes = mem_cgroup_files, |
6d12e2d8 | 5641 | .early_init = 0, |
04046e1a | 5642 | .use_id = 1, |
48ddbe19 | 5643 | .__DEPRECATED_clear_css_refs = true, |
8cdea7c0 | 5644 | }; |
c077719b | 5645 | |
c255a458 | 5646 | #ifdef CONFIG_MEMCG_SWAP |
a42c390c MH |
5647 | static int __init enable_swap_account(char *s) |
5648 | { | |
5649 | /* consider enabled if no parameter or 1 is given */ | |
a2c8990a | 5650 | if (!strcmp(s, "1")) |
a42c390c | 5651 | really_do_swap_account = 1; |
a2c8990a | 5652 | else if (!strcmp(s, "0")) |
a42c390c MH |
5653 | really_do_swap_account = 0; |
5654 | return 1; | |
5655 | } | |
a2c8990a | 5656 | __setup("swapaccount=", enable_swap_account); |
c077719b | 5657 | |
c077719b | 5658 | #endif |