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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 | * | |
7ae1e1d0 GC |
13 | * Kernel Memory Controller |
14 | * Copyright (C) 2012 Parallels Inc. and Google Inc. | |
15 | * Authors: Glauber Costa and Suleiman Souhlal | |
16 | * | |
8cdea7c0 BS |
17 | * This program is free software; you can redistribute it and/or modify |
18 | * it under the terms of the GNU General Public License as published by | |
19 | * the Free Software Foundation; either version 2 of the License, or | |
20 | * (at your option) any later version. | |
21 | * | |
22 | * This program is distributed in the hope that it will be useful, | |
23 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
24 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
25 | * GNU General Public License for more details. | |
26 | */ | |
27 | ||
28 | #include <linux/res_counter.h> | |
29 | #include <linux/memcontrol.h> | |
30 | #include <linux/cgroup.h> | |
78fb7466 | 31 | #include <linux/mm.h> |
4ffef5fe | 32 | #include <linux/hugetlb.h> |
d13d1443 | 33 | #include <linux/pagemap.h> |
d52aa412 | 34 | #include <linux/smp.h> |
8a9f3ccd | 35 | #include <linux/page-flags.h> |
66e1707b | 36 | #include <linux/backing-dev.h> |
8a9f3ccd BS |
37 | #include <linux/bit_spinlock.h> |
38 | #include <linux/rcupdate.h> | |
e222432b | 39 | #include <linux/limits.h> |
b9e15baf | 40 | #include <linux/export.h> |
8c7c6e34 | 41 | #include <linux/mutex.h> |
f64c3f54 | 42 | #include <linux/rbtree.h> |
b6ac57d5 | 43 | #include <linux/slab.h> |
66e1707b | 44 | #include <linux/swap.h> |
02491447 | 45 | #include <linux/swapops.h> |
66e1707b | 46 | #include <linux/spinlock.h> |
2e72b634 KS |
47 | #include <linux/eventfd.h> |
48 | #include <linux/sort.h> | |
66e1707b | 49 | #include <linux/fs.h> |
d2ceb9b7 | 50 | #include <linux/seq_file.h> |
33327948 | 51 | #include <linux/vmalloc.h> |
70ddf637 | 52 | #include <linux/vmpressure.h> |
b69408e8 | 53 | #include <linux/mm_inline.h> |
52d4b9ac | 54 | #include <linux/page_cgroup.h> |
cdec2e42 | 55 | #include <linux/cpu.h> |
158e0a2d | 56 | #include <linux/oom.h> |
08e552c6 | 57 | #include "internal.h" |
d1a4c0b3 | 58 | #include <net/sock.h> |
4bd2c1ee | 59 | #include <net/ip.h> |
d1a4c0b3 | 60 | #include <net/tcp_memcontrol.h> |
8cdea7c0 | 61 | |
8697d331 BS |
62 | #include <asm/uaccess.h> |
63 | ||
cc8e970c KM |
64 | #include <trace/events/vmscan.h> |
65 | ||
a181b0e8 | 66 | struct cgroup_subsys mem_cgroup_subsys __read_mostly; |
68ae564b DR |
67 | EXPORT_SYMBOL(mem_cgroup_subsys); |
68 | ||
a181b0e8 | 69 | #define MEM_CGROUP_RECLAIM_RETRIES 5 |
6bbda35c | 70 | static struct mem_cgroup *root_mem_cgroup __read_mostly; |
8cdea7c0 | 71 | |
c255a458 | 72 | #ifdef CONFIG_MEMCG_SWAP |
338c8431 | 73 | /* Turned on only when memory cgroup is enabled && really_do_swap_account = 1 */ |
c077719b | 74 | int do_swap_account __read_mostly; |
a42c390c MH |
75 | |
76 | /* for remember boot option*/ | |
c255a458 | 77 | #ifdef CONFIG_MEMCG_SWAP_ENABLED |
a42c390c MH |
78 | static int really_do_swap_account __initdata = 1; |
79 | #else | |
80 | static int really_do_swap_account __initdata = 0; | |
81 | #endif | |
82 | ||
c077719b | 83 | #else |
a0db00fc | 84 | #define do_swap_account 0 |
c077719b KH |
85 | #endif |
86 | ||
87 | ||
d52aa412 KH |
88 | /* |
89 | * Statistics for memory cgroup. | |
90 | */ | |
91 | enum mem_cgroup_stat_index { | |
92 | /* | |
93 | * For MEM_CONTAINER_TYPE_ALL, usage = pagecache + rss. | |
94 | */ | |
b070e65c DR |
95 | MEM_CGROUP_STAT_CACHE, /* # of pages charged as cache */ |
96 | MEM_CGROUP_STAT_RSS, /* # of pages charged as anon rss */ | |
97 | MEM_CGROUP_STAT_RSS_HUGE, /* # of pages charged as anon huge */ | |
98 | MEM_CGROUP_STAT_FILE_MAPPED, /* # of pages charged as file rss */ | |
99 | MEM_CGROUP_STAT_SWAP, /* # of pages, swapped out */ | |
d52aa412 KH |
100 | MEM_CGROUP_STAT_NSTATS, |
101 | }; | |
102 | ||
af7c4b0e JW |
103 | static const char * const mem_cgroup_stat_names[] = { |
104 | "cache", | |
105 | "rss", | |
b070e65c | 106 | "rss_huge", |
af7c4b0e JW |
107 | "mapped_file", |
108 | "swap", | |
109 | }; | |
110 | ||
e9f8974f JW |
111 | enum mem_cgroup_events_index { |
112 | MEM_CGROUP_EVENTS_PGPGIN, /* # of pages paged in */ | |
113 | MEM_CGROUP_EVENTS_PGPGOUT, /* # of pages paged out */ | |
456f998e YH |
114 | MEM_CGROUP_EVENTS_PGFAULT, /* # of page-faults */ |
115 | MEM_CGROUP_EVENTS_PGMAJFAULT, /* # of major page-faults */ | |
e9f8974f JW |
116 | MEM_CGROUP_EVENTS_NSTATS, |
117 | }; | |
af7c4b0e JW |
118 | |
119 | static const char * const mem_cgroup_events_names[] = { | |
120 | "pgpgin", | |
121 | "pgpgout", | |
122 | "pgfault", | |
123 | "pgmajfault", | |
124 | }; | |
125 | ||
58cf188e SZ |
126 | static const char * const mem_cgroup_lru_names[] = { |
127 | "inactive_anon", | |
128 | "active_anon", | |
129 | "inactive_file", | |
130 | "active_file", | |
131 | "unevictable", | |
132 | }; | |
133 | ||
7a159cc9 JW |
134 | /* |
135 | * Per memcg event counter is incremented at every pagein/pageout. With THP, | |
136 | * it will be incremated by the number of pages. This counter is used for | |
137 | * for trigger some periodic events. This is straightforward and better | |
138 | * than using jiffies etc. to handle periodic memcg event. | |
139 | */ | |
140 | enum mem_cgroup_events_target { | |
141 | MEM_CGROUP_TARGET_THRESH, | |
142 | MEM_CGROUP_TARGET_SOFTLIMIT, | |
453a9bf3 | 143 | MEM_CGROUP_TARGET_NUMAINFO, |
7a159cc9 JW |
144 | MEM_CGROUP_NTARGETS, |
145 | }; | |
a0db00fc KS |
146 | #define THRESHOLDS_EVENTS_TARGET 128 |
147 | #define SOFTLIMIT_EVENTS_TARGET 1024 | |
148 | #define NUMAINFO_EVENTS_TARGET 1024 | |
e9f8974f | 149 | |
d52aa412 | 150 | struct mem_cgroup_stat_cpu { |
7a159cc9 | 151 | long count[MEM_CGROUP_STAT_NSTATS]; |
e9f8974f | 152 | unsigned long events[MEM_CGROUP_EVENTS_NSTATS]; |
13114716 | 153 | unsigned long nr_page_events; |
7a159cc9 | 154 | unsigned long targets[MEM_CGROUP_NTARGETS]; |
d52aa412 KH |
155 | }; |
156 | ||
527a5ec9 | 157 | struct mem_cgroup_reclaim_iter { |
5f578161 MH |
158 | /* |
159 | * last scanned hierarchy member. Valid only if last_dead_count | |
160 | * matches memcg->dead_count of the hierarchy root group. | |
161 | */ | |
542f85f9 | 162 | struct mem_cgroup *last_visited; |
5f578161 MH |
163 | unsigned long last_dead_count; |
164 | ||
527a5ec9 JW |
165 | /* scan generation, increased every round-trip */ |
166 | unsigned int generation; | |
167 | }; | |
168 | ||
6d12e2d8 KH |
169 | /* |
170 | * per-zone information in memory controller. | |
171 | */ | |
6d12e2d8 | 172 | struct mem_cgroup_per_zone { |
6290df54 | 173 | struct lruvec lruvec; |
1eb49272 | 174 | unsigned long lru_size[NR_LRU_LISTS]; |
3e2f41f1 | 175 | |
527a5ec9 JW |
176 | struct mem_cgroup_reclaim_iter reclaim_iter[DEF_PRIORITY + 1]; |
177 | ||
f64c3f54 BS |
178 | struct rb_node tree_node; /* RB tree node */ |
179 | unsigned long long usage_in_excess;/* Set to the value by which */ | |
180 | /* the soft limit is exceeded*/ | |
181 | bool on_tree; | |
d79154bb | 182 | struct mem_cgroup *memcg; /* Back pointer, we cannot */ |
4e416953 | 183 | /* use container_of */ |
6d12e2d8 | 184 | }; |
6d12e2d8 KH |
185 | |
186 | struct mem_cgroup_per_node { | |
187 | struct mem_cgroup_per_zone zoneinfo[MAX_NR_ZONES]; | |
188 | }; | |
189 | ||
190 | struct mem_cgroup_lru_info { | |
45cf7ebd | 191 | struct mem_cgroup_per_node *nodeinfo[0]; |
6d12e2d8 KH |
192 | }; |
193 | ||
f64c3f54 BS |
194 | /* |
195 | * Cgroups above their limits are maintained in a RB-Tree, independent of | |
196 | * their hierarchy representation | |
197 | */ | |
198 | ||
199 | struct mem_cgroup_tree_per_zone { | |
200 | struct rb_root rb_root; | |
201 | spinlock_t lock; | |
202 | }; | |
203 | ||
204 | struct mem_cgroup_tree_per_node { | |
205 | struct mem_cgroup_tree_per_zone rb_tree_per_zone[MAX_NR_ZONES]; | |
206 | }; | |
207 | ||
208 | struct mem_cgroup_tree { | |
209 | struct mem_cgroup_tree_per_node *rb_tree_per_node[MAX_NUMNODES]; | |
210 | }; | |
211 | ||
212 | static struct mem_cgroup_tree soft_limit_tree __read_mostly; | |
213 | ||
2e72b634 KS |
214 | struct mem_cgroup_threshold { |
215 | struct eventfd_ctx *eventfd; | |
216 | u64 threshold; | |
217 | }; | |
218 | ||
9490ff27 | 219 | /* For threshold */ |
2e72b634 | 220 | struct mem_cgroup_threshold_ary { |
748dad36 | 221 | /* An array index points to threshold just below or equal to usage. */ |
5407a562 | 222 | int current_threshold; |
2e72b634 KS |
223 | /* Size of entries[] */ |
224 | unsigned int size; | |
225 | /* Array of thresholds */ | |
226 | struct mem_cgroup_threshold entries[0]; | |
227 | }; | |
2c488db2 KS |
228 | |
229 | struct mem_cgroup_thresholds { | |
230 | /* Primary thresholds array */ | |
231 | struct mem_cgroup_threshold_ary *primary; | |
232 | /* | |
233 | * Spare threshold array. | |
234 | * This is needed to make mem_cgroup_unregister_event() "never fail". | |
235 | * It must be able to store at least primary->size - 1 entries. | |
236 | */ | |
237 | struct mem_cgroup_threshold_ary *spare; | |
238 | }; | |
239 | ||
9490ff27 KH |
240 | /* for OOM */ |
241 | struct mem_cgroup_eventfd_list { | |
242 | struct list_head list; | |
243 | struct eventfd_ctx *eventfd; | |
244 | }; | |
2e72b634 | 245 | |
c0ff4b85 R |
246 | static void mem_cgroup_threshold(struct mem_cgroup *memcg); |
247 | static void mem_cgroup_oom_notify(struct mem_cgroup *memcg); | |
2e72b634 | 248 | |
8cdea7c0 BS |
249 | /* |
250 | * The memory controller data structure. The memory controller controls both | |
251 | * page cache and RSS per cgroup. We would eventually like to provide | |
252 | * statistics based on the statistics developed by Rik Van Riel for clock-pro, | |
253 | * to help the administrator determine what knobs to tune. | |
254 | * | |
255 | * TODO: Add a water mark for the memory controller. Reclaim will begin when | |
8a9f3ccd BS |
256 | * we hit the water mark. May be even add a low water mark, such that |
257 | * no reclaim occurs from a cgroup at it's low water mark, this is | |
258 | * a feature that will be implemented much later in the future. | |
8cdea7c0 BS |
259 | */ |
260 | struct mem_cgroup { | |
261 | struct cgroup_subsys_state css; | |
262 | /* | |
263 | * the counter to account for memory usage | |
264 | */ | |
265 | struct res_counter res; | |
59927fb9 | 266 | |
70ddf637 AV |
267 | /* vmpressure notifications */ |
268 | struct vmpressure vmpressure; | |
269 | ||
59927fb9 HD |
270 | union { |
271 | /* | |
272 | * the counter to account for mem+swap usage. | |
273 | */ | |
274 | struct res_counter memsw; | |
275 | ||
276 | /* | |
277 | * rcu_freeing is used only when freeing struct mem_cgroup, | |
278 | * so put it into a union to avoid wasting more memory. | |
279 | * It must be disjoint from the css field. It could be | |
280 | * in a union with the res field, but res plays a much | |
281 | * larger part in mem_cgroup life than memsw, and might | |
282 | * be of interest, even at time of free, when debugging. | |
283 | * So share rcu_head with the less interesting memsw. | |
284 | */ | |
285 | struct rcu_head rcu_freeing; | |
286 | /* | |
3afe36b1 GC |
287 | * We also need some space for a worker in deferred freeing. |
288 | * By the time we call it, rcu_freeing is no longer in use. | |
59927fb9 HD |
289 | */ |
290 | struct work_struct work_freeing; | |
291 | }; | |
292 | ||
510fc4e1 GC |
293 | /* |
294 | * the counter to account for kernel memory usage. | |
295 | */ | |
296 | struct res_counter kmem; | |
18f59ea7 BS |
297 | /* |
298 | * Should the accounting and control be hierarchical, per subtree? | |
299 | */ | |
300 | bool use_hierarchy; | |
510fc4e1 | 301 | unsigned long kmem_account_flags; /* See KMEM_ACCOUNTED_*, below */ |
79dfdacc MH |
302 | |
303 | bool oom_lock; | |
304 | atomic_t under_oom; | |
f79d6a46 | 305 | atomic_t oom_wakeups; |
79dfdacc | 306 | |
8c7c6e34 | 307 | atomic_t refcnt; |
14797e23 | 308 | |
1f4c025b | 309 | int swappiness; |
3c11ecf4 KH |
310 | /* OOM-Killer disable */ |
311 | int oom_kill_disable; | |
a7885eb8 | 312 | |
22a668d7 KH |
313 | /* set when res.limit == memsw.limit */ |
314 | bool memsw_is_minimum; | |
315 | ||
2e72b634 KS |
316 | /* protect arrays of thresholds */ |
317 | struct mutex thresholds_lock; | |
318 | ||
319 | /* thresholds for memory usage. RCU-protected */ | |
2c488db2 | 320 | struct mem_cgroup_thresholds thresholds; |
907860ed | 321 | |
2e72b634 | 322 | /* thresholds for mem+swap usage. RCU-protected */ |
2c488db2 | 323 | struct mem_cgroup_thresholds memsw_thresholds; |
907860ed | 324 | |
9490ff27 KH |
325 | /* For oom notifier event fd */ |
326 | struct list_head oom_notify; | |
185efc0f | 327 | |
7dc74be0 DN |
328 | /* |
329 | * Should we move charges of a task when a task is moved into this | |
330 | * mem_cgroup ? And what type of charges should we move ? | |
331 | */ | |
332 | unsigned long move_charge_at_immigrate; | |
619d094b KH |
333 | /* |
334 | * set > 0 if pages under this cgroup are moving to other cgroup. | |
335 | */ | |
336 | atomic_t moving_account; | |
312734c0 KH |
337 | /* taken only while moving_account > 0 */ |
338 | spinlock_t move_lock; | |
d52aa412 | 339 | /* |
c62b1a3b | 340 | * percpu counter. |
d52aa412 | 341 | */ |
3a7951b4 | 342 | struct mem_cgroup_stat_cpu __percpu *stat; |
711d3d2c KH |
343 | /* |
344 | * used when a cpu is offlined or other synchronizations | |
345 | * See mem_cgroup_read_stat(). | |
346 | */ | |
347 | struct mem_cgroup_stat_cpu nocpu_base; | |
348 | spinlock_t pcp_counter_lock; | |
d1a4c0b3 | 349 | |
5f578161 | 350 | atomic_t dead_count; |
4bd2c1ee | 351 | #if defined(CONFIG_MEMCG_KMEM) && defined(CONFIG_INET) |
d1a4c0b3 GC |
352 | struct tcp_memcontrol tcp_mem; |
353 | #endif | |
2633d7a0 GC |
354 | #if defined(CONFIG_MEMCG_KMEM) |
355 | /* analogous to slab_common's slab_caches list. per-memcg */ | |
356 | struct list_head memcg_slab_caches; | |
357 | /* Not a spinlock, we can take a lot of time walking the list */ | |
358 | struct mutex slab_caches_mutex; | |
359 | /* Index in the kmem_cache->memcg_params->memcg_caches array */ | |
360 | int kmemcg_id; | |
361 | #endif | |
45cf7ebd GC |
362 | |
363 | int last_scanned_node; | |
364 | #if MAX_NUMNODES > 1 | |
365 | nodemask_t scan_nodes; | |
366 | atomic_t numainfo_events; | |
367 | atomic_t numainfo_updating; | |
368 | #endif | |
70ddf637 | 369 | |
45cf7ebd GC |
370 | /* |
371 | * Per cgroup active and inactive list, similar to the | |
372 | * per zone LRU lists. | |
373 | * | |
374 | * WARNING: This has to be the last element of the struct. Don't | |
375 | * add new fields after this point. | |
376 | */ | |
377 | struct mem_cgroup_lru_info info; | |
8cdea7c0 BS |
378 | }; |
379 | ||
45cf7ebd GC |
380 | static size_t memcg_size(void) |
381 | { | |
382 | return sizeof(struct mem_cgroup) + | |
76fca229 | 383 | nr_node_ids * sizeof(struct mem_cgroup_per_node *); |
45cf7ebd GC |
384 | } |
385 | ||
510fc4e1 GC |
386 | /* internal only representation about the status of kmem accounting. */ |
387 | enum { | |
388 | KMEM_ACCOUNTED_ACTIVE = 0, /* accounted by this cgroup itself */ | |
a8964b9b | 389 | KMEM_ACCOUNTED_ACTIVATED, /* static key enabled. */ |
7de37682 | 390 | KMEM_ACCOUNTED_DEAD, /* dead memcg with pending kmem charges */ |
510fc4e1 GC |
391 | }; |
392 | ||
a8964b9b GC |
393 | /* We account when limit is on, but only after call sites are patched */ |
394 | #define KMEM_ACCOUNTED_MASK \ | |
395 | ((1 << KMEM_ACCOUNTED_ACTIVE) | (1 << KMEM_ACCOUNTED_ACTIVATED)) | |
510fc4e1 GC |
396 | |
397 | #ifdef CONFIG_MEMCG_KMEM | |
398 | static inline void memcg_kmem_set_active(struct mem_cgroup *memcg) | |
399 | { | |
400 | set_bit(KMEM_ACCOUNTED_ACTIVE, &memcg->kmem_account_flags); | |
401 | } | |
7de37682 GC |
402 | |
403 | static bool memcg_kmem_is_active(struct mem_cgroup *memcg) | |
404 | { | |
405 | return test_bit(KMEM_ACCOUNTED_ACTIVE, &memcg->kmem_account_flags); | |
406 | } | |
407 | ||
a8964b9b GC |
408 | static void memcg_kmem_set_activated(struct mem_cgroup *memcg) |
409 | { | |
410 | set_bit(KMEM_ACCOUNTED_ACTIVATED, &memcg->kmem_account_flags); | |
411 | } | |
412 | ||
55007d84 GC |
413 | static void memcg_kmem_clear_activated(struct mem_cgroup *memcg) |
414 | { | |
415 | clear_bit(KMEM_ACCOUNTED_ACTIVATED, &memcg->kmem_account_flags); | |
416 | } | |
417 | ||
7de37682 GC |
418 | static void memcg_kmem_mark_dead(struct mem_cgroup *memcg) |
419 | { | |
420 | if (test_bit(KMEM_ACCOUNTED_ACTIVE, &memcg->kmem_account_flags)) | |
421 | set_bit(KMEM_ACCOUNTED_DEAD, &memcg->kmem_account_flags); | |
422 | } | |
423 | ||
424 | static bool memcg_kmem_test_and_clear_dead(struct mem_cgroup *memcg) | |
425 | { | |
426 | return test_and_clear_bit(KMEM_ACCOUNTED_DEAD, | |
427 | &memcg->kmem_account_flags); | |
428 | } | |
510fc4e1 GC |
429 | #endif |
430 | ||
7dc74be0 DN |
431 | /* Stuffs for move charges at task migration. */ |
432 | /* | |
ee5e8472 GC |
433 | * Types of charges to be moved. "move_charge_at_immitgrate" and |
434 | * "immigrate_flags" are treated as a left-shifted bitmap of these types. | |
7dc74be0 DN |
435 | */ |
436 | enum move_type { | |
4ffef5fe | 437 | MOVE_CHARGE_TYPE_ANON, /* private anonymous page and swap of it */ |
87946a72 | 438 | MOVE_CHARGE_TYPE_FILE, /* file page(including tmpfs) and swap of it */ |
7dc74be0 DN |
439 | NR_MOVE_TYPE, |
440 | }; | |
441 | ||
4ffef5fe DN |
442 | /* "mc" and its members are protected by cgroup_mutex */ |
443 | static struct move_charge_struct { | |
b1dd693e | 444 | spinlock_t lock; /* for from, to */ |
4ffef5fe DN |
445 | struct mem_cgroup *from; |
446 | struct mem_cgroup *to; | |
ee5e8472 | 447 | unsigned long immigrate_flags; |
4ffef5fe | 448 | unsigned long precharge; |
854ffa8d | 449 | unsigned long moved_charge; |
483c30b5 | 450 | unsigned long moved_swap; |
8033b97c DN |
451 | struct task_struct *moving_task; /* a task moving charges */ |
452 | wait_queue_head_t waitq; /* a waitq for other context */ | |
453 | } mc = { | |
2bd9bb20 | 454 | .lock = __SPIN_LOCK_UNLOCKED(mc.lock), |
8033b97c DN |
455 | .waitq = __WAIT_QUEUE_HEAD_INITIALIZER(mc.waitq), |
456 | }; | |
4ffef5fe | 457 | |
90254a65 DN |
458 | static bool move_anon(void) |
459 | { | |
ee5e8472 | 460 | return test_bit(MOVE_CHARGE_TYPE_ANON, &mc.immigrate_flags); |
90254a65 DN |
461 | } |
462 | ||
87946a72 DN |
463 | static bool move_file(void) |
464 | { | |
ee5e8472 | 465 | return test_bit(MOVE_CHARGE_TYPE_FILE, &mc.immigrate_flags); |
87946a72 DN |
466 | } |
467 | ||
4e416953 BS |
468 | /* |
469 | * Maximum loops in mem_cgroup_hierarchical_reclaim(), used for soft | |
470 | * limit reclaim to prevent infinite loops, if they ever occur. | |
471 | */ | |
a0db00fc KS |
472 | #define MEM_CGROUP_MAX_RECLAIM_LOOPS 100 |
473 | #define MEM_CGROUP_MAX_SOFT_LIMIT_RECLAIM_LOOPS 2 | |
4e416953 | 474 | |
217bc319 KH |
475 | enum charge_type { |
476 | MEM_CGROUP_CHARGE_TYPE_CACHE = 0, | |
41326c17 | 477 | MEM_CGROUP_CHARGE_TYPE_ANON, |
d13d1443 | 478 | MEM_CGROUP_CHARGE_TYPE_SWAPOUT, /* for accounting swapcache */ |
8a9478ca | 479 | MEM_CGROUP_CHARGE_TYPE_DROP, /* a page was unused swap cache */ |
c05555b5 KH |
480 | NR_CHARGE_TYPE, |
481 | }; | |
482 | ||
8c7c6e34 | 483 | /* for encoding cft->private value on file */ |
86ae53e1 GC |
484 | enum res_type { |
485 | _MEM, | |
486 | _MEMSWAP, | |
487 | _OOM_TYPE, | |
510fc4e1 | 488 | _KMEM, |
86ae53e1 GC |
489 | }; |
490 | ||
a0db00fc KS |
491 | #define MEMFILE_PRIVATE(x, val) ((x) << 16 | (val)) |
492 | #define MEMFILE_TYPE(val) ((val) >> 16 & 0xffff) | |
8c7c6e34 | 493 | #define MEMFILE_ATTR(val) ((val) & 0xffff) |
9490ff27 KH |
494 | /* Used for OOM nofiier */ |
495 | #define OOM_CONTROL (0) | |
8c7c6e34 | 496 | |
75822b44 BS |
497 | /* |
498 | * Reclaim flags for mem_cgroup_hierarchical_reclaim | |
499 | */ | |
500 | #define MEM_CGROUP_RECLAIM_NOSWAP_BIT 0x0 | |
501 | #define MEM_CGROUP_RECLAIM_NOSWAP (1 << MEM_CGROUP_RECLAIM_NOSWAP_BIT) | |
502 | #define MEM_CGROUP_RECLAIM_SHRINK_BIT 0x1 | |
503 | #define MEM_CGROUP_RECLAIM_SHRINK (1 << MEM_CGROUP_RECLAIM_SHRINK_BIT) | |
504 | ||
0999821b GC |
505 | /* |
506 | * The memcg_create_mutex will be held whenever a new cgroup is created. | |
507 | * As a consequence, any change that needs to protect against new child cgroups | |
508 | * appearing has to hold it as well. | |
509 | */ | |
510 | static DEFINE_MUTEX(memcg_create_mutex); | |
511 | ||
c0ff4b85 R |
512 | static void mem_cgroup_get(struct mem_cgroup *memcg); |
513 | static void mem_cgroup_put(struct mem_cgroup *memcg); | |
e1aab161 | 514 | |
b2145145 WL |
515 | static inline |
516 | struct mem_cgroup *mem_cgroup_from_css(struct cgroup_subsys_state *s) | |
517 | { | |
518 | return container_of(s, struct mem_cgroup, css); | |
519 | } | |
520 | ||
70ddf637 AV |
521 | /* Some nice accessors for the vmpressure. */ |
522 | struct vmpressure *memcg_to_vmpressure(struct mem_cgroup *memcg) | |
523 | { | |
524 | if (!memcg) | |
525 | memcg = root_mem_cgroup; | |
526 | return &memcg->vmpressure; | |
527 | } | |
528 | ||
529 | struct cgroup_subsys_state *vmpressure_to_css(struct vmpressure *vmpr) | |
530 | { | |
531 | return &container_of(vmpr, struct mem_cgroup, vmpressure)->css; | |
532 | } | |
533 | ||
534 | struct vmpressure *css_to_vmpressure(struct cgroup_subsys_state *css) | |
535 | { | |
536 | return &mem_cgroup_from_css(css)->vmpressure; | |
537 | } | |
538 | ||
7ffc0edc MH |
539 | static inline bool mem_cgroup_is_root(struct mem_cgroup *memcg) |
540 | { | |
541 | return (memcg == root_mem_cgroup); | |
542 | } | |
543 | ||
e1aab161 | 544 | /* Writing them here to avoid exposing memcg's inner layout */ |
4bd2c1ee | 545 | #if defined(CONFIG_INET) && defined(CONFIG_MEMCG_KMEM) |
e1aab161 | 546 | |
e1aab161 GC |
547 | void sock_update_memcg(struct sock *sk) |
548 | { | |
376be5ff | 549 | if (mem_cgroup_sockets_enabled) { |
e1aab161 | 550 | struct mem_cgroup *memcg; |
3f134619 | 551 | struct cg_proto *cg_proto; |
e1aab161 GC |
552 | |
553 | BUG_ON(!sk->sk_prot->proto_cgroup); | |
554 | ||
f3f511e1 GC |
555 | /* Socket cloning can throw us here with sk_cgrp already |
556 | * filled. It won't however, necessarily happen from | |
557 | * process context. So the test for root memcg given | |
558 | * the current task's memcg won't help us in this case. | |
559 | * | |
560 | * Respecting the original socket's memcg is a better | |
561 | * decision in this case. | |
562 | */ | |
563 | if (sk->sk_cgrp) { | |
564 | BUG_ON(mem_cgroup_is_root(sk->sk_cgrp->memcg)); | |
565 | mem_cgroup_get(sk->sk_cgrp->memcg); | |
566 | return; | |
567 | } | |
568 | ||
e1aab161 GC |
569 | rcu_read_lock(); |
570 | memcg = mem_cgroup_from_task(current); | |
3f134619 GC |
571 | cg_proto = sk->sk_prot->proto_cgroup(memcg); |
572 | if (!mem_cgroup_is_root(memcg) && memcg_proto_active(cg_proto)) { | |
e1aab161 | 573 | mem_cgroup_get(memcg); |
3f134619 | 574 | sk->sk_cgrp = cg_proto; |
e1aab161 GC |
575 | } |
576 | rcu_read_unlock(); | |
577 | } | |
578 | } | |
579 | EXPORT_SYMBOL(sock_update_memcg); | |
580 | ||
581 | void sock_release_memcg(struct sock *sk) | |
582 | { | |
376be5ff | 583 | if (mem_cgroup_sockets_enabled && sk->sk_cgrp) { |
e1aab161 GC |
584 | struct mem_cgroup *memcg; |
585 | WARN_ON(!sk->sk_cgrp->memcg); | |
586 | memcg = sk->sk_cgrp->memcg; | |
587 | mem_cgroup_put(memcg); | |
588 | } | |
589 | } | |
d1a4c0b3 GC |
590 | |
591 | struct cg_proto *tcp_proto_cgroup(struct mem_cgroup *memcg) | |
592 | { | |
593 | if (!memcg || mem_cgroup_is_root(memcg)) | |
594 | return NULL; | |
595 | ||
596 | return &memcg->tcp_mem.cg_proto; | |
597 | } | |
598 | EXPORT_SYMBOL(tcp_proto_cgroup); | |
e1aab161 | 599 | |
3f134619 GC |
600 | static void disarm_sock_keys(struct mem_cgroup *memcg) |
601 | { | |
602 | if (!memcg_proto_activated(&memcg->tcp_mem.cg_proto)) | |
603 | return; | |
604 | static_key_slow_dec(&memcg_socket_limit_enabled); | |
605 | } | |
606 | #else | |
607 | static void disarm_sock_keys(struct mem_cgroup *memcg) | |
608 | { | |
609 | } | |
610 | #endif | |
611 | ||
a8964b9b | 612 | #ifdef CONFIG_MEMCG_KMEM |
55007d84 GC |
613 | /* |
614 | * This will be the memcg's index in each cache's ->memcg_params->memcg_caches. | |
615 | * There are two main reasons for not using the css_id for this: | |
616 | * 1) this works better in sparse environments, where we have a lot of memcgs, | |
617 | * but only a few kmem-limited. Or also, if we have, for instance, 200 | |
618 | * memcgs, and none but the 200th is kmem-limited, we'd have to have a | |
619 | * 200 entry array for that. | |
620 | * | |
621 | * 2) In order not to violate the cgroup API, we would like to do all memory | |
622 | * allocation in ->create(). At that point, we haven't yet allocated the | |
623 | * css_id. Having a separate index prevents us from messing with the cgroup | |
624 | * core for this | |
625 | * | |
626 | * The current size of the caches array is stored in | |
627 | * memcg_limited_groups_array_size. It will double each time we have to | |
628 | * increase it. | |
629 | */ | |
630 | static DEFINE_IDA(kmem_limited_groups); | |
749c5415 GC |
631 | int memcg_limited_groups_array_size; |
632 | ||
55007d84 GC |
633 | /* |
634 | * MIN_SIZE is different than 1, because we would like to avoid going through | |
635 | * the alloc/free process all the time. In a small machine, 4 kmem-limited | |
636 | * cgroups is a reasonable guess. In the future, it could be a parameter or | |
637 | * tunable, but that is strictly not necessary. | |
638 | * | |
639 | * MAX_SIZE should be as large as the number of css_ids. Ideally, we could get | |
640 | * this constant directly from cgroup, but it is understandable that this is | |
641 | * better kept as an internal representation in cgroup.c. In any case, the | |
642 | * css_id space is not getting any smaller, and we don't have to necessarily | |
643 | * increase ours as well if it increases. | |
644 | */ | |
645 | #define MEMCG_CACHES_MIN_SIZE 4 | |
646 | #define MEMCG_CACHES_MAX_SIZE 65535 | |
647 | ||
d7f25f8a GC |
648 | /* |
649 | * A lot of the calls to the cache allocation functions are expected to be | |
650 | * inlined by the compiler. Since the calls to memcg_kmem_get_cache are | |
651 | * conditional to this static branch, we'll have to allow modules that does | |
652 | * kmem_cache_alloc and the such to see this symbol as well | |
653 | */ | |
a8964b9b | 654 | struct static_key memcg_kmem_enabled_key; |
d7f25f8a | 655 | EXPORT_SYMBOL(memcg_kmem_enabled_key); |
a8964b9b GC |
656 | |
657 | static void disarm_kmem_keys(struct mem_cgroup *memcg) | |
658 | { | |
55007d84 | 659 | if (memcg_kmem_is_active(memcg)) { |
a8964b9b | 660 | static_key_slow_dec(&memcg_kmem_enabled_key); |
55007d84 GC |
661 | ida_simple_remove(&kmem_limited_groups, memcg->kmemcg_id); |
662 | } | |
bea207c8 GC |
663 | /* |
664 | * This check can't live in kmem destruction function, | |
665 | * since the charges will outlive the cgroup | |
666 | */ | |
667 | WARN_ON(res_counter_read_u64(&memcg->kmem, RES_USAGE) != 0); | |
a8964b9b GC |
668 | } |
669 | #else | |
670 | static void disarm_kmem_keys(struct mem_cgroup *memcg) | |
671 | { | |
672 | } | |
673 | #endif /* CONFIG_MEMCG_KMEM */ | |
674 | ||
675 | static void disarm_static_keys(struct mem_cgroup *memcg) | |
676 | { | |
677 | disarm_sock_keys(memcg); | |
678 | disarm_kmem_keys(memcg); | |
679 | } | |
680 | ||
c0ff4b85 | 681 | static void drain_all_stock_async(struct mem_cgroup *memcg); |
8c7c6e34 | 682 | |
f64c3f54 | 683 | static struct mem_cgroup_per_zone * |
c0ff4b85 | 684 | mem_cgroup_zoneinfo(struct mem_cgroup *memcg, int nid, int zid) |
f64c3f54 | 685 | { |
45cf7ebd | 686 | VM_BUG_ON((unsigned)nid >= nr_node_ids); |
c0ff4b85 | 687 | return &memcg->info.nodeinfo[nid]->zoneinfo[zid]; |
f64c3f54 BS |
688 | } |
689 | ||
c0ff4b85 | 690 | struct cgroup_subsys_state *mem_cgroup_css(struct mem_cgroup *memcg) |
d324236b | 691 | { |
c0ff4b85 | 692 | return &memcg->css; |
d324236b WF |
693 | } |
694 | ||
f64c3f54 | 695 | static struct mem_cgroup_per_zone * |
c0ff4b85 | 696 | page_cgroup_zoneinfo(struct mem_cgroup *memcg, struct page *page) |
f64c3f54 | 697 | { |
97a6c37b JW |
698 | int nid = page_to_nid(page); |
699 | int zid = page_zonenum(page); | |
f64c3f54 | 700 | |
c0ff4b85 | 701 | return mem_cgroup_zoneinfo(memcg, nid, zid); |
f64c3f54 BS |
702 | } |
703 | ||
704 | static struct mem_cgroup_tree_per_zone * | |
705 | soft_limit_tree_node_zone(int nid, int zid) | |
706 | { | |
707 | return &soft_limit_tree.rb_tree_per_node[nid]->rb_tree_per_zone[zid]; | |
708 | } | |
709 | ||
710 | static struct mem_cgroup_tree_per_zone * | |
711 | soft_limit_tree_from_page(struct page *page) | |
712 | { | |
713 | int nid = page_to_nid(page); | |
714 | int zid = page_zonenum(page); | |
715 | ||
716 | return &soft_limit_tree.rb_tree_per_node[nid]->rb_tree_per_zone[zid]; | |
717 | } | |
718 | ||
719 | static void | |
c0ff4b85 | 720 | __mem_cgroup_insert_exceeded(struct mem_cgroup *memcg, |
f64c3f54 | 721 | struct mem_cgroup_per_zone *mz, |
ef8745c1 KH |
722 | struct mem_cgroup_tree_per_zone *mctz, |
723 | unsigned long long new_usage_in_excess) | |
f64c3f54 BS |
724 | { |
725 | struct rb_node **p = &mctz->rb_root.rb_node; | |
726 | struct rb_node *parent = NULL; | |
727 | struct mem_cgroup_per_zone *mz_node; | |
728 | ||
729 | if (mz->on_tree) | |
730 | return; | |
731 | ||
ef8745c1 KH |
732 | mz->usage_in_excess = new_usage_in_excess; |
733 | if (!mz->usage_in_excess) | |
734 | return; | |
f64c3f54 BS |
735 | while (*p) { |
736 | parent = *p; | |
737 | mz_node = rb_entry(parent, struct mem_cgroup_per_zone, | |
738 | tree_node); | |
739 | if (mz->usage_in_excess < mz_node->usage_in_excess) | |
740 | p = &(*p)->rb_left; | |
741 | /* | |
742 | * We can't avoid mem cgroups that are over their soft | |
743 | * limit by the same amount | |
744 | */ | |
745 | else if (mz->usage_in_excess >= mz_node->usage_in_excess) | |
746 | p = &(*p)->rb_right; | |
747 | } | |
748 | rb_link_node(&mz->tree_node, parent, p); | |
749 | rb_insert_color(&mz->tree_node, &mctz->rb_root); | |
750 | mz->on_tree = true; | |
4e416953 BS |
751 | } |
752 | ||
753 | static void | |
c0ff4b85 | 754 | __mem_cgroup_remove_exceeded(struct mem_cgroup *memcg, |
4e416953 BS |
755 | struct mem_cgroup_per_zone *mz, |
756 | struct mem_cgroup_tree_per_zone *mctz) | |
757 | { | |
758 | if (!mz->on_tree) | |
759 | return; | |
760 | rb_erase(&mz->tree_node, &mctz->rb_root); | |
761 | mz->on_tree = false; | |
762 | } | |
763 | ||
f64c3f54 | 764 | static void |
c0ff4b85 | 765 | mem_cgroup_remove_exceeded(struct mem_cgroup *memcg, |
f64c3f54 BS |
766 | struct mem_cgroup_per_zone *mz, |
767 | struct mem_cgroup_tree_per_zone *mctz) | |
768 | { | |
769 | spin_lock(&mctz->lock); | |
c0ff4b85 | 770 | __mem_cgroup_remove_exceeded(memcg, mz, mctz); |
f64c3f54 BS |
771 | spin_unlock(&mctz->lock); |
772 | } | |
773 | ||
f64c3f54 | 774 | |
c0ff4b85 | 775 | static void mem_cgroup_update_tree(struct mem_cgroup *memcg, struct page *page) |
f64c3f54 | 776 | { |
ef8745c1 | 777 | unsigned long long excess; |
f64c3f54 BS |
778 | struct mem_cgroup_per_zone *mz; |
779 | struct mem_cgroup_tree_per_zone *mctz; | |
4e649152 KH |
780 | int nid = page_to_nid(page); |
781 | int zid = page_zonenum(page); | |
f64c3f54 BS |
782 | mctz = soft_limit_tree_from_page(page); |
783 | ||
784 | /* | |
4e649152 KH |
785 | * Necessary to update all ancestors when hierarchy is used. |
786 | * because their event counter is not touched. | |
f64c3f54 | 787 | */ |
c0ff4b85 R |
788 | for (; memcg; memcg = parent_mem_cgroup(memcg)) { |
789 | mz = mem_cgroup_zoneinfo(memcg, nid, zid); | |
790 | excess = res_counter_soft_limit_excess(&memcg->res); | |
4e649152 KH |
791 | /* |
792 | * We have to update the tree if mz is on RB-tree or | |
793 | * mem is over its softlimit. | |
794 | */ | |
ef8745c1 | 795 | if (excess || mz->on_tree) { |
4e649152 KH |
796 | spin_lock(&mctz->lock); |
797 | /* if on-tree, remove it */ | |
798 | if (mz->on_tree) | |
c0ff4b85 | 799 | __mem_cgroup_remove_exceeded(memcg, mz, mctz); |
4e649152 | 800 | /* |
ef8745c1 KH |
801 | * Insert again. mz->usage_in_excess will be updated. |
802 | * If excess is 0, no tree ops. | |
4e649152 | 803 | */ |
c0ff4b85 | 804 | __mem_cgroup_insert_exceeded(memcg, mz, mctz, excess); |
4e649152 KH |
805 | spin_unlock(&mctz->lock); |
806 | } | |
f64c3f54 BS |
807 | } |
808 | } | |
809 | ||
c0ff4b85 | 810 | static void mem_cgroup_remove_from_trees(struct mem_cgroup *memcg) |
f64c3f54 BS |
811 | { |
812 | int node, zone; | |
813 | struct mem_cgroup_per_zone *mz; | |
814 | struct mem_cgroup_tree_per_zone *mctz; | |
815 | ||
3ed28fa1 | 816 | for_each_node(node) { |
f64c3f54 | 817 | for (zone = 0; zone < MAX_NR_ZONES; zone++) { |
c0ff4b85 | 818 | mz = mem_cgroup_zoneinfo(memcg, node, zone); |
f64c3f54 | 819 | mctz = soft_limit_tree_node_zone(node, zone); |
c0ff4b85 | 820 | mem_cgroup_remove_exceeded(memcg, mz, mctz); |
f64c3f54 BS |
821 | } |
822 | } | |
823 | } | |
824 | ||
4e416953 BS |
825 | static struct mem_cgroup_per_zone * |
826 | __mem_cgroup_largest_soft_limit_node(struct mem_cgroup_tree_per_zone *mctz) | |
827 | { | |
828 | struct rb_node *rightmost = NULL; | |
26251eaf | 829 | struct mem_cgroup_per_zone *mz; |
4e416953 BS |
830 | |
831 | retry: | |
26251eaf | 832 | mz = NULL; |
4e416953 BS |
833 | rightmost = rb_last(&mctz->rb_root); |
834 | if (!rightmost) | |
835 | goto done; /* Nothing to reclaim from */ | |
836 | ||
837 | mz = rb_entry(rightmost, struct mem_cgroup_per_zone, tree_node); | |
838 | /* | |
839 | * Remove the node now but someone else can add it back, | |
840 | * we will to add it back at the end of reclaim to its correct | |
841 | * position in the tree. | |
842 | */ | |
d79154bb HD |
843 | __mem_cgroup_remove_exceeded(mz->memcg, mz, mctz); |
844 | if (!res_counter_soft_limit_excess(&mz->memcg->res) || | |
845 | !css_tryget(&mz->memcg->css)) | |
4e416953 BS |
846 | goto retry; |
847 | done: | |
848 | return mz; | |
849 | } | |
850 | ||
851 | static struct mem_cgroup_per_zone * | |
852 | mem_cgroup_largest_soft_limit_node(struct mem_cgroup_tree_per_zone *mctz) | |
853 | { | |
854 | struct mem_cgroup_per_zone *mz; | |
855 | ||
856 | spin_lock(&mctz->lock); | |
857 | mz = __mem_cgroup_largest_soft_limit_node(mctz); | |
858 | spin_unlock(&mctz->lock); | |
859 | return mz; | |
860 | } | |
861 | ||
711d3d2c KH |
862 | /* |
863 | * Implementation Note: reading percpu statistics for memcg. | |
864 | * | |
865 | * Both of vmstat[] and percpu_counter has threshold and do periodic | |
866 | * synchronization to implement "quick" read. There are trade-off between | |
867 | * reading cost and precision of value. Then, we may have a chance to implement | |
868 | * a periodic synchronizion of counter in memcg's counter. | |
869 | * | |
870 | * But this _read() function is used for user interface now. The user accounts | |
871 | * memory usage by memory cgroup and he _always_ requires exact value because | |
872 | * he accounts memory. Even if we provide quick-and-fuzzy read, we always | |
873 | * have to visit all online cpus and make sum. So, for now, unnecessary | |
874 | * synchronization is not implemented. (just implemented for cpu hotplug) | |
875 | * | |
876 | * If there are kernel internal actions which can make use of some not-exact | |
877 | * value, and reading all cpu value can be performance bottleneck in some | |
878 | * common workload, threashold and synchonization as vmstat[] should be | |
879 | * implemented. | |
880 | */ | |
c0ff4b85 | 881 | static long mem_cgroup_read_stat(struct mem_cgroup *memcg, |
7a159cc9 | 882 | enum mem_cgroup_stat_index idx) |
c62b1a3b | 883 | { |
7a159cc9 | 884 | long val = 0; |
c62b1a3b | 885 | int cpu; |
c62b1a3b | 886 | |
711d3d2c KH |
887 | get_online_cpus(); |
888 | for_each_online_cpu(cpu) | |
c0ff4b85 | 889 | val += per_cpu(memcg->stat->count[idx], cpu); |
711d3d2c | 890 | #ifdef CONFIG_HOTPLUG_CPU |
c0ff4b85 R |
891 | spin_lock(&memcg->pcp_counter_lock); |
892 | val += memcg->nocpu_base.count[idx]; | |
893 | spin_unlock(&memcg->pcp_counter_lock); | |
711d3d2c KH |
894 | #endif |
895 | put_online_cpus(); | |
c62b1a3b KH |
896 | return val; |
897 | } | |
898 | ||
c0ff4b85 | 899 | static void mem_cgroup_swap_statistics(struct mem_cgroup *memcg, |
0c3e73e8 BS |
900 | bool charge) |
901 | { | |
902 | int val = (charge) ? 1 : -1; | |
bff6bb83 | 903 | this_cpu_add(memcg->stat->count[MEM_CGROUP_STAT_SWAP], val); |
0c3e73e8 BS |
904 | } |
905 | ||
c0ff4b85 | 906 | static unsigned long mem_cgroup_read_events(struct mem_cgroup *memcg, |
e9f8974f JW |
907 | enum mem_cgroup_events_index idx) |
908 | { | |
909 | unsigned long val = 0; | |
910 | int cpu; | |
911 | ||
912 | for_each_online_cpu(cpu) | |
c0ff4b85 | 913 | val += per_cpu(memcg->stat->events[idx], cpu); |
e9f8974f | 914 | #ifdef CONFIG_HOTPLUG_CPU |
c0ff4b85 R |
915 | spin_lock(&memcg->pcp_counter_lock); |
916 | val += memcg->nocpu_base.events[idx]; | |
917 | spin_unlock(&memcg->pcp_counter_lock); | |
e9f8974f JW |
918 | #endif |
919 | return val; | |
920 | } | |
921 | ||
c0ff4b85 | 922 | static void mem_cgroup_charge_statistics(struct mem_cgroup *memcg, |
b070e65c | 923 | struct page *page, |
b2402857 | 924 | bool anon, int nr_pages) |
d52aa412 | 925 | { |
c62b1a3b KH |
926 | preempt_disable(); |
927 | ||
b2402857 KH |
928 | /* |
929 | * Here, RSS means 'mapped anon' and anon's SwapCache. Shmem/tmpfs is | |
930 | * counted as CACHE even if it's on ANON LRU. | |
931 | */ | |
932 | if (anon) | |
933 | __this_cpu_add(memcg->stat->count[MEM_CGROUP_STAT_RSS], | |
c0ff4b85 | 934 | nr_pages); |
d52aa412 | 935 | else |
b2402857 | 936 | __this_cpu_add(memcg->stat->count[MEM_CGROUP_STAT_CACHE], |
c0ff4b85 | 937 | nr_pages); |
55e462b0 | 938 | |
b070e65c DR |
939 | if (PageTransHuge(page)) |
940 | __this_cpu_add(memcg->stat->count[MEM_CGROUP_STAT_RSS_HUGE], | |
941 | nr_pages); | |
942 | ||
e401f176 KH |
943 | /* pagein of a big page is an event. So, ignore page size */ |
944 | if (nr_pages > 0) | |
c0ff4b85 | 945 | __this_cpu_inc(memcg->stat->events[MEM_CGROUP_EVENTS_PGPGIN]); |
3751d604 | 946 | else { |
c0ff4b85 | 947 | __this_cpu_inc(memcg->stat->events[MEM_CGROUP_EVENTS_PGPGOUT]); |
3751d604 KH |
948 | nr_pages = -nr_pages; /* for event */ |
949 | } | |
e401f176 | 950 | |
13114716 | 951 | __this_cpu_add(memcg->stat->nr_page_events, nr_pages); |
2e72b634 | 952 | |
c62b1a3b | 953 | preempt_enable(); |
6d12e2d8 KH |
954 | } |
955 | ||
bb2a0de9 | 956 | unsigned long |
4d7dcca2 | 957 | mem_cgroup_get_lru_size(struct lruvec *lruvec, enum lru_list lru) |
074291fe KK |
958 | { |
959 | struct mem_cgroup_per_zone *mz; | |
960 | ||
961 | mz = container_of(lruvec, struct mem_cgroup_per_zone, lruvec); | |
962 | return mz->lru_size[lru]; | |
963 | } | |
964 | ||
965 | static unsigned long | |
c0ff4b85 | 966 | mem_cgroup_zone_nr_lru_pages(struct mem_cgroup *memcg, int nid, int zid, |
bb2a0de9 | 967 | unsigned int lru_mask) |
889976db YH |
968 | { |
969 | struct mem_cgroup_per_zone *mz; | |
f156ab93 | 970 | enum lru_list lru; |
bb2a0de9 KH |
971 | unsigned long ret = 0; |
972 | ||
c0ff4b85 | 973 | mz = mem_cgroup_zoneinfo(memcg, nid, zid); |
bb2a0de9 | 974 | |
f156ab93 HD |
975 | for_each_lru(lru) { |
976 | if (BIT(lru) & lru_mask) | |
977 | ret += mz->lru_size[lru]; | |
bb2a0de9 KH |
978 | } |
979 | return ret; | |
980 | } | |
981 | ||
982 | static unsigned long | |
c0ff4b85 | 983 | mem_cgroup_node_nr_lru_pages(struct mem_cgroup *memcg, |
bb2a0de9 KH |
984 | int nid, unsigned int lru_mask) |
985 | { | |
889976db YH |
986 | u64 total = 0; |
987 | int zid; | |
988 | ||
bb2a0de9 | 989 | for (zid = 0; zid < MAX_NR_ZONES; zid++) |
c0ff4b85 R |
990 | total += mem_cgroup_zone_nr_lru_pages(memcg, |
991 | nid, zid, lru_mask); | |
bb2a0de9 | 992 | |
889976db YH |
993 | return total; |
994 | } | |
bb2a0de9 | 995 | |
c0ff4b85 | 996 | static unsigned long mem_cgroup_nr_lru_pages(struct mem_cgroup *memcg, |
bb2a0de9 | 997 | unsigned int lru_mask) |
6d12e2d8 | 998 | { |
889976db | 999 | int nid; |
6d12e2d8 KH |
1000 | u64 total = 0; |
1001 | ||
31aaea4a | 1002 | for_each_node_state(nid, N_MEMORY) |
c0ff4b85 | 1003 | total += mem_cgroup_node_nr_lru_pages(memcg, nid, lru_mask); |
6d12e2d8 | 1004 | return total; |
d52aa412 KH |
1005 | } |
1006 | ||
f53d7ce3 JW |
1007 | static bool mem_cgroup_event_ratelimit(struct mem_cgroup *memcg, |
1008 | enum mem_cgroup_events_target target) | |
7a159cc9 JW |
1009 | { |
1010 | unsigned long val, next; | |
1011 | ||
13114716 | 1012 | val = __this_cpu_read(memcg->stat->nr_page_events); |
4799401f | 1013 | next = __this_cpu_read(memcg->stat->targets[target]); |
7a159cc9 | 1014 | /* from time_after() in jiffies.h */ |
f53d7ce3 JW |
1015 | if ((long)next - (long)val < 0) { |
1016 | switch (target) { | |
1017 | case MEM_CGROUP_TARGET_THRESH: | |
1018 | next = val + THRESHOLDS_EVENTS_TARGET; | |
1019 | break; | |
1020 | case MEM_CGROUP_TARGET_SOFTLIMIT: | |
1021 | next = val + SOFTLIMIT_EVENTS_TARGET; | |
1022 | break; | |
1023 | case MEM_CGROUP_TARGET_NUMAINFO: | |
1024 | next = val + NUMAINFO_EVENTS_TARGET; | |
1025 | break; | |
1026 | default: | |
1027 | break; | |
1028 | } | |
1029 | __this_cpu_write(memcg->stat->targets[target], next); | |
1030 | return true; | |
7a159cc9 | 1031 | } |
f53d7ce3 | 1032 | return false; |
d2265e6f KH |
1033 | } |
1034 | ||
1035 | /* | |
1036 | * Check events in order. | |
1037 | * | |
1038 | */ | |
c0ff4b85 | 1039 | static void memcg_check_events(struct mem_cgroup *memcg, struct page *page) |
d2265e6f | 1040 | { |
4799401f | 1041 | preempt_disable(); |
d2265e6f | 1042 | /* threshold event is triggered in finer grain than soft limit */ |
f53d7ce3 JW |
1043 | if (unlikely(mem_cgroup_event_ratelimit(memcg, |
1044 | MEM_CGROUP_TARGET_THRESH))) { | |
82b3f2a7 AM |
1045 | bool do_softlimit; |
1046 | bool do_numainfo __maybe_unused; | |
f53d7ce3 JW |
1047 | |
1048 | do_softlimit = mem_cgroup_event_ratelimit(memcg, | |
1049 | MEM_CGROUP_TARGET_SOFTLIMIT); | |
1050 | #if MAX_NUMNODES > 1 | |
1051 | do_numainfo = mem_cgroup_event_ratelimit(memcg, | |
1052 | MEM_CGROUP_TARGET_NUMAINFO); | |
1053 | #endif | |
1054 | preempt_enable(); | |
1055 | ||
c0ff4b85 | 1056 | mem_cgroup_threshold(memcg); |
f53d7ce3 | 1057 | if (unlikely(do_softlimit)) |
c0ff4b85 | 1058 | mem_cgroup_update_tree(memcg, page); |
453a9bf3 | 1059 | #if MAX_NUMNODES > 1 |
f53d7ce3 | 1060 | if (unlikely(do_numainfo)) |
c0ff4b85 | 1061 | atomic_inc(&memcg->numainfo_events); |
453a9bf3 | 1062 | #endif |
f53d7ce3 JW |
1063 | } else |
1064 | preempt_enable(); | |
d2265e6f KH |
1065 | } |
1066 | ||
d1a4c0b3 | 1067 | struct mem_cgroup *mem_cgroup_from_cont(struct cgroup *cont) |
8cdea7c0 | 1068 | { |
b2145145 WL |
1069 | return mem_cgroup_from_css( |
1070 | cgroup_subsys_state(cont, mem_cgroup_subsys_id)); | |
8cdea7c0 BS |
1071 | } |
1072 | ||
cf475ad2 | 1073 | struct mem_cgroup *mem_cgroup_from_task(struct task_struct *p) |
78fb7466 | 1074 | { |
31a78f23 BS |
1075 | /* |
1076 | * mm_update_next_owner() may clear mm->owner to NULL | |
1077 | * if it races with swapoff, page migration, etc. | |
1078 | * So this can be called with p == NULL. | |
1079 | */ | |
1080 | if (unlikely(!p)) | |
1081 | return NULL; | |
1082 | ||
b2145145 | 1083 | return mem_cgroup_from_css(task_subsys_state(p, mem_cgroup_subsys_id)); |
78fb7466 PE |
1084 | } |
1085 | ||
a433658c | 1086 | struct mem_cgroup *try_get_mem_cgroup_from_mm(struct mm_struct *mm) |
54595fe2 | 1087 | { |
c0ff4b85 | 1088 | struct mem_cgroup *memcg = NULL; |
0b7f569e KH |
1089 | |
1090 | if (!mm) | |
1091 | return NULL; | |
54595fe2 KH |
1092 | /* |
1093 | * Because we have no locks, mm->owner's may be being moved to other | |
1094 | * cgroup. We use css_tryget() here even if this looks | |
1095 | * pessimistic (rather than adding locks here). | |
1096 | */ | |
1097 | rcu_read_lock(); | |
1098 | do { | |
c0ff4b85 R |
1099 | memcg = mem_cgroup_from_task(rcu_dereference(mm->owner)); |
1100 | if (unlikely(!memcg)) | |
54595fe2 | 1101 | break; |
c0ff4b85 | 1102 | } while (!css_tryget(&memcg->css)); |
54595fe2 | 1103 | rcu_read_unlock(); |
c0ff4b85 | 1104 | return memcg; |
54595fe2 KH |
1105 | } |
1106 | ||
16248d8f MH |
1107 | /* |
1108 | * Returns a next (in a pre-order walk) alive memcg (with elevated css | |
1109 | * ref. count) or NULL if the whole root's subtree has been visited. | |
1110 | * | |
1111 | * helper function to be used by mem_cgroup_iter | |
1112 | */ | |
1113 | static struct mem_cgroup *__mem_cgroup_iter_next(struct mem_cgroup *root, | |
1114 | struct mem_cgroup *last_visited) | |
1115 | { | |
1116 | struct cgroup *prev_cgroup, *next_cgroup; | |
1117 | ||
1118 | /* | |
1119 | * Root is not visited by cgroup iterators so it needs an | |
1120 | * explicit visit. | |
1121 | */ | |
1122 | if (!last_visited) | |
1123 | return root; | |
1124 | ||
1125 | prev_cgroup = (last_visited == root) ? NULL | |
1126 | : last_visited->css.cgroup; | |
1127 | skip_node: | |
1128 | next_cgroup = cgroup_next_descendant_pre( | |
1129 | prev_cgroup, root->css.cgroup); | |
1130 | ||
1131 | /* | |
1132 | * Even if we found a group we have to make sure it is | |
1133 | * alive. css && !memcg means that the groups should be | |
1134 | * skipped and we should continue the tree walk. | |
1135 | * last_visited css is safe to use because it is | |
1136 | * protected by css_get and the tree walk is rcu safe. | |
1137 | */ | |
1138 | if (next_cgroup) { | |
1139 | struct mem_cgroup *mem = mem_cgroup_from_cont( | |
1140 | next_cgroup); | |
1141 | if (css_tryget(&mem->css)) | |
1142 | return mem; | |
1143 | else { | |
1144 | prev_cgroup = next_cgroup; | |
1145 | goto skip_node; | |
1146 | } | |
1147 | } | |
1148 | ||
1149 | return NULL; | |
1150 | } | |
1151 | ||
5660048c JW |
1152 | /** |
1153 | * mem_cgroup_iter - iterate over memory cgroup hierarchy | |
1154 | * @root: hierarchy root | |
1155 | * @prev: previously returned memcg, NULL on first invocation | |
1156 | * @reclaim: cookie for shared reclaim walks, NULL for full walks | |
1157 | * | |
1158 | * Returns references to children of the hierarchy below @root, or | |
1159 | * @root itself, or %NULL after a full round-trip. | |
1160 | * | |
1161 | * Caller must pass the return value in @prev on subsequent | |
1162 | * invocations for reference counting, or use mem_cgroup_iter_break() | |
1163 | * to cancel a hierarchy walk before the round-trip is complete. | |
1164 | * | |
1165 | * Reclaimers can specify a zone and a priority level in @reclaim to | |
1166 | * divide up the memcgs in the hierarchy among all concurrent | |
1167 | * reclaimers operating on the same zone and priority. | |
1168 | */ | |
1169 | struct mem_cgroup *mem_cgroup_iter(struct mem_cgroup *root, | |
1170 | struct mem_cgroup *prev, | |
1171 | struct mem_cgroup_reclaim_cookie *reclaim) | |
14067bb3 | 1172 | { |
9f3a0d09 | 1173 | struct mem_cgroup *memcg = NULL; |
542f85f9 | 1174 | struct mem_cgroup *last_visited = NULL; |
5f578161 | 1175 | unsigned long uninitialized_var(dead_count); |
711d3d2c | 1176 | |
5660048c JW |
1177 | if (mem_cgroup_disabled()) |
1178 | return NULL; | |
1179 | ||
9f3a0d09 JW |
1180 | if (!root) |
1181 | root = root_mem_cgroup; | |
7d74b06f | 1182 | |
9f3a0d09 | 1183 | if (prev && !reclaim) |
542f85f9 | 1184 | last_visited = prev; |
14067bb3 | 1185 | |
9f3a0d09 JW |
1186 | if (!root->use_hierarchy && root != root_mem_cgroup) { |
1187 | if (prev) | |
c40046f3 | 1188 | goto out_css_put; |
9f3a0d09 JW |
1189 | return root; |
1190 | } | |
14067bb3 | 1191 | |
542f85f9 | 1192 | rcu_read_lock(); |
9f3a0d09 | 1193 | while (!memcg) { |
527a5ec9 | 1194 | struct mem_cgroup_reclaim_iter *uninitialized_var(iter); |
711d3d2c | 1195 | |
527a5ec9 JW |
1196 | if (reclaim) { |
1197 | int nid = zone_to_nid(reclaim->zone); | |
1198 | int zid = zone_idx(reclaim->zone); | |
1199 | struct mem_cgroup_per_zone *mz; | |
1200 | ||
1201 | mz = mem_cgroup_zoneinfo(root, nid, zid); | |
1202 | iter = &mz->reclaim_iter[reclaim->priority]; | |
542f85f9 | 1203 | if (prev && reclaim->generation != iter->generation) { |
5f578161 | 1204 | iter->last_visited = NULL; |
542f85f9 MH |
1205 | goto out_unlock; |
1206 | } | |
5f578161 MH |
1207 | |
1208 | /* | |
1209 | * If the dead_count mismatches, a destruction | |
1210 | * has happened or is happening concurrently. | |
1211 | * If the dead_count matches, a destruction | |
1212 | * might still happen concurrently, but since | |
1213 | * we checked under RCU, that destruction | |
1214 | * won't free the object until we release the | |
1215 | * RCU reader lock. Thus, the dead_count | |
1216 | * check verifies the pointer is still valid, | |
1217 | * css_tryget() verifies the cgroup pointed to | |
1218 | * is alive. | |
1219 | */ | |
1220 | dead_count = atomic_read(&root->dead_count); | |
89dc991f JW |
1221 | if (dead_count == iter->last_dead_count) { |
1222 | smp_rmb(); | |
1223 | last_visited = iter->last_visited; | |
5fb67b91 | 1224 | if (last_visited && last_visited != root && |
89dc991f | 1225 | !css_tryget(&last_visited->css)) |
5f578161 | 1226 | last_visited = NULL; |
5f578161 | 1227 | } |
527a5ec9 | 1228 | } |
7d74b06f | 1229 | |
16248d8f | 1230 | memcg = __mem_cgroup_iter_next(root, last_visited); |
14067bb3 | 1231 | |
527a5ec9 | 1232 | if (reclaim) { |
5fb67b91 | 1233 | if (last_visited && last_visited != root) |
542f85f9 MH |
1234 | css_put(&last_visited->css); |
1235 | ||
19f39402 | 1236 | iter->last_visited = memcg; |
5f578161 MH |
1237 | smp_wmb(); |
1238 | iter->last_dead_count = dead_count; | |
542f85f9 | 1239 | |
19f39402 | 1240 | if (!memcg) |
527a5ec9 JW |
1241 | iter->generation++; |
1242 | else if (!prev && memcg) | |
1243 | reclaim->generation = iter->generation; | |
1244 | } | |
9f3a0d09 | 1245 | |
19f39402 | 1246 | if (prev && !memcg) |
542f85f9 | 1247 | goto out_unlock; |
9f3a0d09 | 1248 | } |
542f85f9 MH |
1249 | out_unlock: |
1250 | rcu_read_unlock(); | |
c40046f3 MH |
1251 | out_css_put: |
1252 | if (prev && prev != root) | |
1253 | css_put(&prev->css); | |
1254 | ||
9f3a0d09 | 1255 | return memcg; |
14067bb3 | 1256 | } |
7d74b06f | 1257 | |
5660048c JW |
1258 | /** |
1259 | * mem_cgroup_iter_break - abort a hierarchy walk prematurely | |
1260 | * @root: hierarchy root | |
1261 | * @prev: last visited hierarchy member as returned by mem_cgroup_iter() | |
1262 | */ | |
1263 | void mem_cgroup_iter_break(struct mem_cgroup *root, | |
1264 | struct mem_cgroup *prev) | |
9f3a0d09 JW |
1265 | { |
1266 | if (!root) | |
1267 | root = root_mem_cgroup; | |
1268 | if (prev && prev != root) | |
1269 | css_put(&prev->css); | |
1270 | } | |
7d74b06f | 1271 | |
9f3a0d09 JW |
1272 | /* |
1273 | * Iteration constructs for visiting all cgroups (under a tree). If | |
1274 | * loops are exited prematurely (break), mem_cgroup_iter_break() must | |
1275 | * be used for reference counting. | |
1276 | */ | |
1277 | #define for_each_mem_cgroup_tree(iter, root) \ | |
527a5ec9 | 1278 | for (iter = mem_cgroup_iter(root, NULL, NULL); \ |
9f3a0d09 | 1279 | iter != NULL; \ |
527a5ec9 | 1280 | iter = mem_cgroup_iter(root, iter, NULL)) |
711d3d2c | 1281 | |
9f3a0d09 | 1282 | #define for_each_mem_cgroup(iter) \ |
527a5ec9 | 1283 | for (iter = mem_cgroup_iter(NULL, NULL, NULL); \ |
9f3a0d09 | 1284 | iter != NULL; \ |
527a5ec9 | 1285 | iter = mem_cgroup_iter(NULL, iter, NULL)) |
14067bb3 | 1286 | |
68ae564b | 1287 | void __mem_cgroup_count_vm_event(struct mm_struct *mm, enum vm_event_item idx) |
456f998e | 1288 | { |
c0ff4b85 | 1289 | struct mem_cgroup *memcg; |
456f998e | 1290 | |
456f998e | 1291 | rcu_read_lock(); |
c0ff4b85 R |
1292 | memcg = mem_cgroup_from_task(rcu_dereference(mm->owner)); |
1293 | if (unlikely(!memcg)) | |
456f998e YH |
1294 | goto out; |
1295 | ||
1296 | switch (idx) { | |
456f998e | 1297 | case PGFAULT: |
0e574a93 JW |
1298 | this_cpu_inc(memcg->stat->events[MEM_CGROUP_EVENTS_PGFAULT]); |
1299 | break; | |
1300 | case PGMAJFAULT: | |
1301 | this_cpu_inc(memcg->stat->events[MEM_CGROUP_EVENTS_PGMAJFAULT]); | |
456f998e YH |
1302 | break; |
1303 | default: | |
1304 | BUG(); | |
1305 | } | |
1306 | out: | |
1307 | rcu_read_unlock(); | |
1308 | } | |
68ae564b | 1309 | EXPORT_SYMBOL(__mem_cgroup_count_vm_event); |
456f998e | 1310 | |
925b7673 JW |
1311 | /** |
1312 | * mem_cgroup_zone_lruvec - get the lru list vector for a zone and memcg | |
1313 | * @zone: zone of the wanted lruvec | |
fa9add64 | 1314 | * @memcg: memcg of the wanted lruvec |
925b7673 JW |
1315 | * |
1316 | * Returns the lru list vector holding pages for the given @zone and | |
1317 | * @mem. This can be the global zone lruvec, if the memory controller | |
1318 | * is disabled. | |
1319 | */ | |
1320 | struct lruvec *mem_cgroup_zone_lruvec(struct zone *zone, | |
1321 | struct mem_cgroup *memcg) | |
1322 | { | |
1323 | struct mem_cgroup_per_zone *mz; | |
bea8c150 | 1324 | struct lruvec *lruvec; |
925b7673 | 1325 | |
bea8c150 HD |
1326 | if (mem_cgroup_disabled()) { |
1327 | lruvec = &zone->lruvec; | |
1328 | goto out; | |
1329 | } | |
925b7673 JW |
1330 | |
1331 | mz = mem_cgroup_zoneinfo(memcg, zone_to_nid(zone), zone_idx(zone)); | |
bea8c150 HD |
1332 | lruvec = &mz->lruvec; |
1333 | out: | |
1334 | /* | |
1335 | * Since a node can be onlined after the mem_cgroup was created, | |
1336 | * we have to be prepared to initialize lruvec->zone here; | |
1337 | * and if offlined then reonlined, we need to reinitialize it. | |
1338 | */ | |
1339 | if (unlikely(lruvec->zone != zone)) | |
1340 | lruvec->zone = zone; | |
1341 | return lruvec; | |
925b7673 JW |
1342 | } |
1343 | ||
08e552c6 KH |
1344 | /* |
1345 | * Following LRU functions are allowed to be used without PCG_LOCK. | |
1346 | * Operations are called by routine of global LRU independently from memcg. | |
1347 | * What we have to take care of here is validness of pc->mem_cgroup. | |
1348 | * | |
1349 | * Changes to pc->mem_cgroup happens when | |
1350 | * 1. charge | |
1351 | * 2. moving account | |
1352 | * In typical case, "charge" is done before add-to-lru. Exception is SwapCache. | |
1353 | * It is added to LRU before charge. | |
1354 | * If PCG_USED bit is not set, page_cgroup is not added to this private LRU. | |
1355 | * When moving account, the page is not on LRU. It's isolated. | |
1356 | */ | |
4f98a2fe | 1357 | |
925b7673 | 1358 | /** |
fa9add64 | 1359 | * mem_cgroup_page_lruvec - return lruvec for adding an lru page |
925b7673 | 1360 | * @page: the page |
fa9add64 | 1361 | * @zone: zone of the page |
925b7673 | 1362 | */ |
fa9add64 | 1363 | struct lruvec *mem_cgroup_page_lruvec(struct page *page, struct zone *zone) |
08e552c6 | 1364 | { |
08e552c6 | 1365 | struct mem_cgroup_per_zone *mz; |
925b7673 JW |
1366 | struct mem_cgroup *memcg; |
1367 | struct page_cgroup *pc; | |
bea8c150 | 1368 | struct lruvec *lruvec; |
6d12e2d8 | 1369 | |
bea8c150 HD |
1370 | if (mem_cgroup_disabled()) { |
1371 | lruvec = &zone->lruvec; | |
1372 | goto out; | |
1373 | } | |
925b7673 | 1374 | |
08e552c6 | 1375 | pc = lookup_page_cgroup(page); |
38c5d72f | 1376 | memcg = pc->mem_cgroup; |
7512102c HD |
1377 | |
1378 | /* | |
fa9add64 | 1379 | * Surreptitiously switch any uncharged offlist page to root: |
7512102c HD |
1380 | * an uncharged page off lru does nothing to secure |
1381 | * its former mem_cgroup from sudden removal. | |
1382 | * | |
1383 | * Our caller holds lru_lock, and PageCgroupUsed is updated | |
1384 | * under page_cgroup lock: between them, they make all uses | |
1385 | * of pc->mem_cgroup safe. | |
1386 | */ | |
fa9add64 | 1387 | if (!PageLRU(page) && !PageCgroupUsed(pc) && memcg != root_mem_cgroup) |
7512102c HD |
1388 | pc->mem_cgroup = memcg = root_mem_cgroup; |
1389 | ||
925b7673 | 1390 | mz = page_cgroup_zoneinfo(memcg, page); |
bea8c150 HD |
1391 | lruvec = &mz->lruvec; |
1392 | out: | |
1393 | /* | |
1394 | * Since a node can be onlined after the mem_cgroup was created, | |
1395 | * we have to be prepared to initialize lruvec->zone here; | |
1396 | * and if offlined then reonlined, we need to reinitialize it. | |
1397 | */ | |
1398 | if (unlikely(lruvec->zone != zone)) | |
1399 | lruvec->zone = zone; | |
1400 | return lruvec; | |
08e552c6 | 1401 | } |
b69408e8 | 1402 | |
925b7673 | 1403 | /** |
fa9add64 HD |
1404 | * mem_cgroup_update_lru_size - account for adding or removing an lru page |
1405 | * @lruvec: mem_cgroup per zone lru vector | |
1406 | * @lru: index of lru list the page is sitting on | |
1407 | * @nr_pages: positive when adding or negative when removing | |
925b7673 | 1408 | * |
fa9add64 HD |
1409 | * This function must be called when a page is added to or removed from an |
1410 | * lru list. | |
3f58a829 | 1411 | */ |
fa9add64 HD |
1412 | void mem_cgroup_update_lru_size(struct lruvec *lruvec, enum lru_list lru, |
1413 | int nr_pages) | |
3f58a829 MK |
1414 | { |
1415 | struct mem_cgroup_per_zone *mz; | |
fa9add64 | 1416 | unsigned long *lru_size; |
3f58a829 MK |
1417 | |
1418 | if (mem_cgroup_disabled()) | |
1419 | return; | |
1420 | ||
fa9add64 HD |
1421 | mz = container_of(lruvec, struct mem_cgroup_per_zone, lruvec); |
1422 | lru_size = mz->lru_size + lru; | |
1423 | *lru_size += nr_pages; | |
1424 | VM_BUG_ON((long)(*lru_size) < 0); | |
08e552c6 | 1425 | } |
544122e5 | 1426 | |
3e92041d | 1427 | /* |
c0ff4b85 | 1428 | * Checks whether given mem is same or in the root_mem_cgroup's |
3e92041d MH |
1429 | * hierarchy subtree |
1430 | */ | |
c3ac9a8a JW |
1431 | bool __mem_cgroup_same_or_subtree(const struct mem_cgroup *root_memcg, |
1432 | struct mem_cgroup *memcg) | |
3e92041d | 1433 | { |
91c63734 JW |
1434 | if (root_memcg == memcg) |
1435 | return true; | |
3a981f48 | 1436 | if (!root_memcg->use_hierarchy || !memcg) |
91c63734 | 1437 | return false; |
c3ac9a8a JW |
1438 | return css_is_ancestor(&memcg->css, &root_memcg->css); |
1439 | } | |
1440 | ||
1441 | static bool mem_cgroup_same_or_subtree(const struct mem_cgroup *root_memcg, | |
1442 | struct mem_cgroup *memcg) | |
1443 | { | |
1444 | bool ret; | |
1445 | ||
91c63734 | 1446 | rcu_read_lock(); |
c3ac9a8a | 1447 | ret = __mem_cgroup_same_or_subtree(root_memcg, memcg); |
91c63734 JW |
1448 | rcu_read_unlock(); |
1449 | return ret; | |
3e92041d MH |
1450 | } |
1451 | ||
c0ff4b85 | 1452 | int task_in_mem_cgroup(struct task_struct *task, const struct mem_cgroup *memcg) |
4c4a2214 DR |
1453 | { |
1454 | int ret; | |
0b7f569e | 1455 | struct mem_cgroup *curr = NULL; |
158e0a2d | 1456 | struct task_struct *p; |
4c4a2214 | 1457 | |
158e0a2d | 1458 | p = find_lock_task_mm(task); |
de077d22 DR |
1459 | if (p) { |
1460 | curr = try_get_mem_cgroup_from_mm(p->mm); | |
1461 | task_unlock(p); | |
1462 | } else { | |
1463 | /* | |
1464 | * All threads may have already detached their mm's, but the oom | |
1465 | * killer still needs to detect if they have already been oom | |
1466 | * killed to prevent needlessly killing additional tasks. | |
1467 | */ | |
1468 | task_lock(task); | |
1469 | curr = mem_cgroup_from_task(task); | |
1470 | if (curr) | |
1471 | css_get(&curr->css); | |
1472 | task_unlock(task); | |
1473 | } | |
0b7f569e KH |
1474 | if (!curr) |
1475 | return 0; | |
d31f56db | 1476 | /* |
c0ff4b85 | 1477 | * We should check use_hierarchy of "memcg" not "curr". Because checking |
d31f56db | 1478 | * use_hierarchy of "curr" here make this function true if hierarchy is |
c0ff4b85 R |
1479 | * enabled in "curr" and "curr" is a child of "memcg" in *cgroup* |
1480 | * hierarchy(even if use_hierarchy is disabled in "memcg"). | |
d31f56db | 1481 | */ |
c0ff4b85 | 1482 | ret = mem_cgroup_same_or_subtree(memcg, curr); |
0b7f569e | 1483 | css_put(&curr->css); |
4c4a2214 DR |
1484 | return ret; |
1485 | } | |
1486 | ||
c56d5c7d | 1487 | int mem_cgroup_inactive_anon_is_low(struct lruvec *lruvec) |
14797e23 | 1488 | { |
9b272977 | 1489 | unsigned long inactive_ratio; |
14797e23 | 1490 | unsigned long inactive; |
9b272977 | 1491 | unsigned long active; |
c772be93 | 1492 | unsigned long gb; |
14797e23 | 1493 | |
4d7dcca2 HD |
1494 | inactive = mem_cgroup_get_lru_size(lruvec, LRU_INACTIVE_ANON); |
1495 | active = mem_cgroup_get_lru_size(lruvec, LRU_ACTIVE_ANON); | |
14797e23 | 1496 | |
c772be93 KM |
1497 | gb = (inactive + active) >> (30 - PAGE_SHIFT); |
1498 | if (gb) | |
1499 | inactive_ratio = int_sqrt(10 * gb); | |
1500 | else | |
1501 | inactive_ratio = 1; | |
1502 | ||
9b272977 | 1503 | return inactive * inactive_ratio < active; |
14797e23 KM |
1504 | } |
1505 | ||
6d61ef40 BS |
1506 | #define mem_cgroup_from_res_counter(counter, member) \ |
1507 | container_of(counter, struct mem_cgroup, member) | |
1508 | ||
19942822 | 1509 | /** |
9d11ea9f | 1510 | * mem_cgroup_margin - calculate chargeable space of a memory cgroup |
dad7557e | 1511 | * @memcg: the memory cgroup |
19942822 | 1512 | * |
9d11ea9f | 1513 | * Returns the maximum amount of memory @mem can be charged with, in |
7ec99d62 | 1514 | * pages. |
19942822 | 1515 | */ |
c0ff4b85 | 1516 | static unsigned long mem_cgroup_margin(struct mem_cgroup *memcg) |
19942822 | 1517 | { |
9d11ea9f JW |
1518 | unsigned long long margin; |
1519 | ||
c0ff4b85 | 1520 | margin = res_counter_margin(&memcg->res); |
9d11ea9f | 1521 | if (do_swap_account) |
c0ff4b85 | 1522 | margin = min(margin, res_counter_margin(&memcg->memsw)); |
7ec99d62 | 1523 | return margin >> PAGE_SHIFT; |
19942822 JW |
1524 | } |
1525 | ||
1f4c025b | 1526 | int mem_cgroup_swappiness(struct mem_cgroup *memcg) |
a7885eb8 KM |
1527 | { |
1528 | struct cgroup *cgrp = memcg->css.cgroup; | |
a7885eb8 KM |
1529 | |
1530 | /* root ? */ | |
1531 | if (cgrp->parent == NULL) | |
1532 | return vm_swappiness; | |
1533 | ||
bf1ff263 | 1534 | return memcg->swappiness; |
a7885eb8 KM |
1535 | } |
1536 | ||
619d094b KH |
1537 | /* |
1538 | * memcg->moving_account is used for checking possibility that some thread is | |
1539 | * calling move_account(). When a thread on CPU-A starts moving pages under | |
1540 | * a memcg, other threads should check memcg->moving_account under | |
1541 | * rcu_read_lock(), like this: | |
1542 | * | |
1543 | * CPU-A CPU-B | |
1544 | * rcu_read_lock() | |
1545 | * memcg->moving_account+1 if (memcg->mocing_account) | |
1546 | * take heavy locks. | |
1547 | * synchronize_rcu() update something. | |
1548 | * rcu_read_unlock() | |
1549 | * start move here. | |
1550 | */ | |
4331f7d3 KH |
1551 | |
1552 | /* for quick checking without looking up memcg */ | |
1553 | atomic_t memcg_moving __read_mostly; | |
1554 | ||
c0ff4b85 | 1555 | static void mem_cgroup_start_move(struct mem_cgroup *memcg) |
32047e2a | 1556 | { |
4331f7d3 | 1557 | atomic_inc(&memcg_moving); |
619d094b | 1558 | atomic_inc(&memcg->moving_account); |
32047e2a KH |
1559 | synchronize_rcu(); |
1560 | } | |
1561 | ||
c0ff4b85 | 1562 | static void mem_cgroup_end_move(struct mem_cgroup *memcg) |
32047e2a | 1563 | { |
619d094b KH |
1564 | /* |
1565 | * Now, mem_cgroup_clear_mc() may call this function with NULL. | |
1566 | * We check NULL in callee rather than caller. | |
1567 | */ | |
4331f7d3 KH |
1568 | if (memcg) { |
1569 | atomic_dec(&memcg_moving); | |
619d094b | 1570 | atomic_dec(&memcg->moving_account); |
4331f7d3 | 1571 | } |
32047e2a | 1572 | } |
619d094b | 1573 | |
32047e2a KH |
1574 | /* |
1575 | * 2 routines for checking "mem" is under move_account() or not. | |
1576 | * | |
13fd1dd9 AM |
1577 | * mem_cgroup_stolen() - checking whether a cgroup is mc.from or not. This |
1578 | * is used for avoiding races in accounting. If true, | |
32047e2a KH |
1579 | * pc->mem_cgroup may be overwritten. |
1580 | * | |
1581 | * mem_cgroup_under_move() - checking a cgroup is mc.from or mc.to or | |
1582 | * under hierarchy of moving cgroups. This is for | |
1583 | * waiting at hith-memory prressure caused by "move". | |
1584 | */ | |
1585 | ||
13fd1dd9 | 1586 | static bool mem_cgroup_stolen(struct mem_cgroup *memcg) |
32047e2a KH |
1587 | { |
1588 | VM_BUG_ON(!rcu_read_lock_held()); | |
619d094b | 1589 | return atomic_read(&memcg->moving_account) > 0; |
32047e2a | 1590 | } |
4b534334 | 1591 | |
c0ff4b85 | 1592 | static bool mem_cgroup_under_move(struct mem_cgroup *memcg) |
4b534334 | 1593 | { |
2bd9bb20 KH |
1594 | struct mem_cgroup *from; |
1595 | struct mem_cgroup *to; | |
4b534334 | 1596 | bool ret = false; |
2bd9bb20 KH |
1597 | /* |
1598 | * Unlike task_move routines, we access mc.to, mc.from not under | |
1599 | * mutual exclusion by cgroup_mutex. Here, we take spinlock instead. | |
1600 | */ | |
1601 | spin_lock(&mc.lock); | |
1602 | from = mc.from; | |
1603 | to = mc.to; | |
1604 | if (!from) | |
1605 | goto unlock; | |
3e92041d | 1606 | |
c0ff4b85 R |
1607 | ret = mem_cgroup_same_or_subtree(memcg, from) |
1608 | || mem_cgroup_same_or_subtree(memcg, to); | |
2bd9bb20 KH |
1609 | unlock: |
1610 | spin_unlock(&mc.lock); | |
4b534334 KH |
1611 | return ret; |
1612 | } | |
1613 | ||
c0ff4b85 | 1614 | static bool mem_cgroup_wait_acct_move(struct mem_cgroup *memcg) |
4b534334 KH |
1615 | { |
1616 | if (mc.moving_task && current != mc.moving_task) { | |
c0ff4b85 | 1617 | if (mem_cgroup_under_move(memcg)) { |
4b534334 KH |
1618 | DEFINE_WAIT(wait); |
1619 | prepare_to_wait(&mc.waitq, &wait, TASK_INTERRUPTIBLE); | |
1620 | /* moving charge context might have finished. */ | |
1621 | if (mc.moving_task) | |
1622 | schedule(); | |
1623 | finish_wait(&mc.waitq, &wait); | |
1624 | return true; | |
1625 | } | |
1626 | } | |
1627 | return false; | |
1628 | } | |
1629 | ||
312734c0 KH |
1630 | /* |
1631 | * Take this lock when | |
1632 | * - a code tries to modify page's memcg while it's USED. | |
1633 | * - a code tries to modify page state accounting in a memcg. | |
13fd1dd9 | 1634 | * see mem_cgroup_stolen(), too. |
312734c0 KH |
1635 | */ |
1636 | static void move_lock_mem_cgroup(struct mem_cgroup *memcg, | |
1637 | unsigned long *flags) | |
1638 | { | |
1639 | spin_lock_irqsave(&memcg->move_lock, *flags); | |
1640 | } | |
1641 | ||
1642 | static void move_unlock_mem_cgroup(struct mem_cgroup *memcg, | |
1643 | unsigned long *flags) | |
1644 | { | |
1645 | spin_unlock_irqrestore(&memcg->move_lock, *flags); | |
1646 | } | |
1647 | ||
58cf188e | 1648 | #define K(x) ((x) << (PAGE_SHIFT-10)) |
e222432b | 1649 | /** |
58cf188e | 1650 | * mem_cgroup_print_oom_info: Print OOM information relevant to memory controller. |
e222432b BS |
1651 | * @memcg: The memory cgroup that went over limit |
1652 | * @p: Task that is going to be killed | |
1653 | * | |
1654 | * NOTE: @memcg and @p's mem_cgroup can be different when hierarchy is | |
1655 | * enabled | |
1656 | */ | |
1657 | void mem_cgroup_print_oom_info(struct mem_cgroup *memcg, struct task_struct *p) | |
1658 | { | |
1659 | struct cgroup *task_cgrp; | |
1660 | struct cgroup *mem_cgrp; | |
1661 | /* | |
1662 | * Need a buffer in BSS, can't rely on allocations. The code relies | |
1663 | * on the assumption that OOM is serialized for memory controller. | |
1664 | * If this assumption is broken, revisit this code. | |
1665 | */ | |
1666 | static char memcg_name[PATH_MAX]; | |
1667 | int ret; | |
58cf188e SZ |
1668 | struct mem_cgroup *iter; |
1669 | unsigned int i; | |
e222432b | 1670 | |
58cf188e | 1671 | if (!p) |
e222432b BS |
1672 | return; |
1673 | ||
e222432b BS |
1674 | rcu_read_lock(); |
1675 | ||
1676 | mem_cgrp = memcg->css.cgroup; | |
1677 | task_cgrp = task_cgroup(p, mem_cgroup_subsys_id); | |
1678 | ||
1679 | ret = cgroup_path(task_cgrp, memcg_name, PATH_MAX); | |
1680 | if (ret < 0) { | |
1681 | /* | |
1682 | * Unfortunately, we are unable to convert to a useful name | |
1683 | * But we'll still print out the usage information | |
1684 | */ | |
1685 | rcu_read_unlock(); | |
1686 | goto done; | |
1687 | } | |
1688 | rcu_read_unlock(); | |
1689 | ||
d045197f | 1690 | pr_info("Task in %s killed", memcg_name); |
e222432b BS |
1691 | |
1692 | rcu_read_lock(); | |
1693 | ret = cgroup_path(mem_cgrp, memcg_name, PATH_MAX); | |
1694 | if (ret < 0) { | |
1695 | rcu_read_unlock(); | |
1696 | goto done; | |
1697 | } | |
1698 | rcu_read_unlock(); | |
1699 | ||
1700 | /* | |
1701 | * Continues from above, so we don't need an KERN_ level | |
1702 | */ | |
d045197f | 1703 | pr_cont(" as a result of limit of %s\n", memcg_name); |
e222432b BS |
1704 | done: |
1705 | ||
d045197f | 1706 | pr_info("memory: usage %llukB, limit %llukB, failcnt %llu\n", |
e222432b BS |
1707 | res_counter_read_u64(&memcg->res, RES_USAGE) >> 10, |
1708 | res_counter_read_u64(&memcg->res, RES_LIMIT) >> 10, | |
1709 | res_counter_read_u64(&memcg->res, RES_FAILCNT)); | |
d045197f | 1710 | pr_info("memory+swap: usage %llukB, limit %llukB, failcnt %llu\n", |
e222432b BS |
1711 | res_counter_read_u64(&memcg->memsw, RES_USAGE) >> 10, |
1712 | res_counter_read_u64(&memcg->memsw, RES_LIMIT) >> 10, | |
1713 | res_counter_read_u64(&memcg->memsw, RES_FAILCNT)); | |
d045197f | 1714 | pr_info("kmem: usage %llukB, limit %llukB, failcnt %llu\n", |
510fc4e1 GC |
1715 | res_counter_read_u64(&memcg->kmem, RES_USAGE) >> 10, |
1716 | res_counter_read_u64(&memcg->kmem, RES_LIMIT) >> 10, | |
1717 | res_counter_read_u64(&memcg->kmem, RES_FAILCNT)); | |
58cf188e SZ |
1718 | |
1719 | for_each_mem_cgroup_tree(iter, memcg) { | |
1720 | pr_info("Memory cgroup stats"); | |
1721 | ||
1722 | rcu_read_lock(); | |
1723 | ret = cgroup_path(iter->css.cgroup, memcg_name, PATH_MAX); | |
1724 | if (!ret) | |
1725 | pr_cont(" for %s", memcg_name); | |
1726 | rcu_read_unlock(); | |
1727 | pr_cont(":"); | |
1728 | ||
1729 | for (i = 0; i < MEM_CGROUP_STAT_NSTATS; i++) { | |
1730 | if (i == MEM_CGROUP_STAT_SWAP && !do_swap_account) | |
1731 | continue; | |
1732 | pr_cont(" %s:%ldKB", mem_cgroup_stat_names[i], | |
1733 | K(mem_cgroup_read_stat(iter, i))); | |
1734 | } | |
1735 | ||
1736 | for (i = 0; i < NR_LRU_LISTS; i++) | |
1737 | pr_cont(" %s:%luKB", mem_cgroup_lru_names[i], | |
1738 | K(mem_cgroup_nr_lru_pages(iter, BIT(i)))); | |
1739 | ||
1740 | pr_cont("\n"); | |
1741 | } | |
e222432b BS |
1742 | } |
1743 | ||
81d39c20 KH |
1744 | /* |
1745 | * This function returns the number of memcg under hierarchy tree. Returns | |
1746 | * 1(self count) if no children. | |
1747 | */ | |
c0ff4b85 | 1748 | static int mem_cgroup_count_children(struct mem_cgroup *memcg) |
81d39c20 KH |
1749 | { |
1750 | int num = 0; | |
7d74b06f KH |
1751 | struct mem_cgroup *iter; |
1752 | ||
c0ff4b85 | 1753 | for_each_mem_cgroup_tree(iter, memcg) |
7d74b06f | 1754 | num++; |
81d39c20 KH |
1755 | return num; |
1756 | } | |
1757 | ||
a63d83f4 DR |
1758 | /* |
1759 | * Return the memory (and swap, if configured) limit for a memcg. | |
1760 | */ | |
9cbb78bb | 1761 | static u64 mem_cgroup_get_limit(struct mem_cgroup *memcg) |
a63d83f4 DR |
1762 | { |
1763 | u64 limit; | |
a63d83f4 | 1764 | |
f3e8eb70 | 1765 | limit = res_counter_read_u64(&memcg->res, RES_LIMIT); |
f3e8eb70 | 1766 | |
a63d83f4 | 1767 | /* |
9a5a8f19 | 1768 | * Do not consider swap space if we cannot swap due to swappiness |
a63d83f4 | 1769 | */ |
9a5a8f19 MH |
1770 | if (mem_cgroup_swappiness(memcg)) { |
1771 | u64 memsw; | |
1772 | ||
1773 | limit += total_swap_pages << PAGE_SHIFT; | |
1774 | memsw = res_counter_read_u64(&memcg->memsw, RES_LIMIT); | |
1775 | ||
1776 | /* | |
1777 | * If memsw is finite and limits the amount of swap space | |
1778 | * available to this memcg, return that limit. | |
1779 | */ | |
1780 | limit = min(limit, memsw); | |
1781 | } | |
1782 | ||
1783 | return limit; | |
a63d83f4 DR |
1784 | } |
1785 | ||
19965460 DR |
1786 | static void mem_cgroup_out_of_memory(struct mem_cgroup *memcg, gfp_t gfp_mask, |
1787 | int order) | |
9cbb78bb DR |
1788 | { |
1789 | struct mem_cgroup *iter; | |
1790 | unsigned long chosen_points = 0; | |
1791 | unsigned long totalpages; | |
1792 | unsigned int points = 0; | |
1793 | struct task_struct *chosen = NULL; | |
1794 | ||
876aafbf | 1795 | /* |
465adcf1 DR |
1796 | * If current has a pending SIGKILL or is exiting, then automatically |
1797 | * select it. The goal is to allow it to allocate so that it may | |
1798 | * quickly exit and free its memory. | |
876aafbf | 1799 | */ |
465adcf1 | 1800 | if (fatal_signal_pending(current) || current->flags & PF_EXITING) { |
876aafbf DR |
1801 | set_thread_flag(TIF_MEMDIE); |
1802 | return; | |
1803 | } | |
1804 | ||
1805 | check_panic_on_oom(CONSTRAINT_MEMCG, gfp_mask, order, NULL); | |
9cbb78bb DR |
1806 | totalpages = mem_cgroup_get_limit(memcg) >> PAGE_SHIFT ? : 1; |
1807 | for_each_mem_cgroup_tree(iter, memcg) { | |
1808 | struct cgroup *cgroup = iter->css.cgroup; | |
1809 | struct cgroup_iter it; | |
1810 | struct task_struct *task; | |
1811 | ||
1812 | cgroup_iter_start(cgroup, &it); | |
1813 | while ((task = cgroup_iter_next(cgroup, &it))) { | |
1814 | switch (oom_scan_process_thread(task, totalpages, NULL, | |
1815 | false)) { | |
1816 | case OOM_SCAN_SELECT: | |
1817 | if (chosen) | |
1818 | put_task_struct(chosen); | |
1819 | chosen = task; | |
1820 | chosen_points = ULONG_MAX; | |
1821 | get_task_struct(chosen); | |
1822 | /* fall through */ | |
1823 | case OOM_SCAN_CONTINUE: | |
1824 | continue; | |
1825 | case OOM_SCAN_ABORT: | |
1826 | cgroup_iter_end(cgroup, &it); | |
1827 | mem_cgroup_iter_break(memcg, iter); | |
1828 | if (chosen) | |
1829 | put_task_struct(chosen); | |
1830 | return; | |
1831 | case OOM_SCAN_OK: | |
1832 | break; | |
1833 | }; | |
1834 | points = oom_badness(task, memcg, NULL, totalpages); | |
1835 | if (points > chosen_points) { | |
1836 | if (chosen) | |
1837 | put_task_struct(chosen); | |
1838 | chosen = task; | |
1839 | chosen_points = points; | |
1840 | get_task_struct(chosen); | |
1841 | } | |
1842 | } | |
1843 | cgroup_iter_end(cgroup, &it); | |
1844 | } | |
1845 | ||
1846 | if (!chosen) | |
1847 | return; | |
1848 | points = chosen_points * 1000 / totalpages; | |
9cbb78bb DR |
1849 | oom_kill_process(chosen, gfp_mask, order, points, totalpages, memcg, |
1850 | NULL, "Memory cgroup out of memory"); | |
9cbb78bb DR |
1851 | } |
1852 | ||
5660048c JW |
1853 | static unsigned long mem_cgroup_reclaim(struct mem_cgroup *memcg, |
1854 | gfp_t gfp_mask, | |
1855 | unsigned long flags) | |
1856 | { | |
1857 | unsigned long total = 0; | |
1858 | bool noswap = false; | |
1859 | int loop; | |
1860 | ||
1861 | if (flags & MEM_CGROUP_RECLAIM_NOSWAP) | |
1862 | noswap = true; | |
1863 | if (!(flags & MEM_CGROUP_RECLAIM_SHRINK) && memcg->memsw_is_minimum) | |
1864 | noswap = true; | |
1865 | ||
1866 | for (loop = 0; loop < MEM_CGROUP_MAX_RECLAIM_LOOPS; loop++) { | |
1867 | if (loop) | |
1868 | drain_all_stock_async(memcg); | |
1869 | total += try_to_free_mem_cgroup_pages(memcg, gfp_mask, noswap); | |
1870 | /* | |
1871 | * Allow limit shrinkers, which are triggered directly | |
1872 | * by userspace, to catch signals and stop reclaim | |
1873 | * after minimal progress, regardless of the margin. | |
1874 | */ | |
1875 | if (total && (flags & MEM_CGROUP_RECLAIM_SHRINK)) | |
1876 | break; | |
1877 | if (mem_cgroup_margin(memcg)) | |
1878 | break; | |
1879 | /* | |
1880 | * If nothing was reclaimed after two attempts, there | |
1881 | * may be no reclaimable pages in this hierarchy. | |
1882 | */ | |
1883 | if (loop && !total) | |
1884 | break; | |
1885 | } | |
1886 | return total; | |
1887 | } | |
1888 | ||
4d0c066d KH |
1889 | /** |
1890 | * test_mem_cgroup_node_reclaimable | |
dad7557e | 1891 | * @memcg: the target memcg |
4d0c066d KH |
1892 | * @nid: the node ID to be checked. |
1893 | * @noswap : specify true here if the user wants flle only information. | |
1894 | * | |
1895 | * This function returns whether the specified memcg contains any | |
1896 | * reclaimable pages on a node. Returns true if there are any reclaimable | |
1897 | * pages in the node. | |
1898 | */ | |
c0ff4b85 | 1899 | static bool test_mem_cgroup_node_reclaimable(struct mem_cgroup *memcg, |
4d0c066d KH |
1900 | int nid, bool noswap) |
1901 | { | |
c0ff4b85 | 1902 | if (mem_cgroup_node_nr_lru_pages(memcg, nid, LRU_ALL_FILE)) |
4d0c066d KH |
1903 | return true; |
1904 | if (noswap || !total_swap_pages) | |
1905 | return false; | |
c0ff4b85 | 1906 | if (mem_cgroup_node_nr_lru_pages(memcg, nid, LRU_ALL_ANON)) |
4d0c066d KH |
1907 | return true; |
1908 | return false; | |
1909 | ||
1910 | } | |
889976db YH |
1911 | #if MAX_NUMNODES > 1 |
1912 | ||
1913 | /* | |
1914 | * Always updating the nodemask is not very good - even if we have an empty | |
1915 | * list or the wrong list here, we can start from some node and traverse all | |
1916 | * nodes based on the zonelist. So update the list loosely once per 10 secs. | |
1917 | * | |
1918 | */ | |
c0ff4b85 | 1919 | static void mem_cgroup_may_update_nodemask(struct mem_cgroup *memcg) |
889976db YH |
1920 | { |
1921 | int nid; | |
453a9bf3 KH |
1922 | /* |
1923 | * numainfo_events > 0 means there was at least NUMAINFO_EVENTS_TARGET | |
1924 | * pagein/pageout changes since the last update. | |
1925 | */ | |
c0ff4b85 | 1926 | if (!atomic_read(&memcg->numainfo_events)) |
453a9bf3 | 1927 | return; |
c0ff4b85 | 1928 | if (atomic_inc_return(&memcg->numainfo_updating) > 1) |
889976db YH |
1929 | return; |
1930 | ||
889976db | 1931 | /* make a nodemask where this memcg uses memory from */ |
31aaea4a | 1932 | memcg->scan_nodes = node_states[N_MEMORY]; |
889976db | 1933 | |
31aaea4a | 1934 | for_each_node_mask(nid, node_states[N_MEMORY]) { |
889976db | 1935 | |
c0ff4b85 R |
1936 | if (!test_mem_cgroup_node_reclaimable(memcg, nid, false)) |
1937 | node_clear(nid, memcg->scan_nodes); | |
889976db | 1938 | } |
453a9bf3 | 1939 | |
c0ff4b85 R |
1940 | atomic_set(&memcg->numainfo_events, 0); |
1941 | atomic_set(&memcg->numainfo_updating, 0); | |
889976db YH |
1942 | } |
1943 | ||
1944 | /* | |
1945 | * Selecting a node where we start reclaim from. Because what we need is just | |
1946 | * reducing usage counter, start from anywhere is O,K. Considering | |
1947 | * memory reclaim from current node, there are pros. and cons. | |
1948 | * | |
1949 | * Freeing memory from current node means freeing memory from a node which | |
1950 | * we'll use or we've used. So, it may make LRU bad. And if several threads | |
1951 | * hit limits, it will see a contention on a node. But freeing from remote | |
1952 | * node means more costs for memory reclaim because of memory latency. | |
1953 | * | |
1954 | * Now, we use round-robin. Better algorithm is welcomed. | |
1955 | */ | |
c0ff4b85 | 1956 | int mem_cgroup_select_victim_node(struct mem_cgroup *memcg) |
889976db YH |
1957 | { |
1958 | int node; | |
1959 | ||
c0ff4b85 R |
1960 | mem_cgroup_may_update_nodemask(memcg); |
1961 | node = memcg->last_scanned_node; | |
889976db | 1962 | |
c0ff4b85 | 1963 | node = next_node(node, memcg->scan_nodes); |
889976db | 1964 | if (node == MAX_NUMNODES) |
c0ff4b85 | 1965 | node = first_node(memcg->scan_nodes); |
889976db YH |
1966 | /* |
1967 | * We call this when we hit limit, not when pages are added to LRU. | |
1968 | * No LRU may hold pages because all pages are UNEVICTABLE or | |
1969 | * memcg is too small and all pages are not on LRU. In that case, | |
1970 | * we use curret node. | |
1971 | */ | |
1972 | if (unlikely(node == MAX_NUMNODES)) | |
1973 | node = numa_node_id(); | |
1974 | ||
c0ff4b85 | 1975 | memcg->last_scanned_node = node; |
889976db YH |
1976 | return node; |
1977 | } | |
1978 | ||
4d0c066d KH |
1979 | /* |
1980 | * Check all nodes whether it contains reclaimable pages or not. | |
1981 | * For quick scan, we make use of scan_nodes. This will allow us to skip | |
1982 | * unused nodes. But scan_nodes is lazily updated and may not cotain | |
1983 | * enough new information. We need to do double check. | |
1984 | */ | |
6bbda35c | 1985 | static bool mem_cgroup_reclaimable(struct mem_cgroup *memcg, bool noswap) |
4d0c066d KH |
1986 | { |
1987 | int nid; | |
1988 | ||
1989 | /* | |
1990 | * quick check...making use of scan_node. | |
1991 | * We can skip unused nodes. | |
1992 | */ | |
c0ff4b85 R |
1993 | if (!nodes_empty(memcg->scan_nodes)) { |
1994 | for (nid = first_node(memcg->scan_nodes); | |
4d0c066d | 1995 | nid < MAX_NUMNODES; |
c0ff4b85 | 1996 | nid = next_node(nid, memcg->scan_nodes)) { |
4d0c066d | 1997 | |
c0ff4b85 | 1998 | if (test_mem_cgroup_node_reclaimable(memcg, nid, noswap)) |
4d0c066d KH |
1999 | return true; |
2000 | } | |
2001 | } | |
2002 | /* | |
2003 | * Check rest of nodes. | |
2004 | */ | |
31aaea4a | 2005 | for_each_node_state(nid, N_MEMORY) { |
c0ff4b85 | 2006 | if (node_isset(nid, memcg->scan_nodes)) |
4d0c066d | 2007 | continue; |
c0ff4b85 | 2008 | if (test_mem_cgroup_node_reclaimable(memcg, nid, noswap)) |
4d0c066d KH |
2009 | return true; |
2010 | } | |
2011 | return false; | |
2012 | } | |
2013 | ||
889976db | 2014 | #else |
c0ff4b85 | 2015 | int mem_cgroup_select_victim_node(struct mem_cgroup *memcg) |
889976db YH |
2016 | { |
2017 | return 0; | |
2018 | } | |
4d0c066d | 2019 | |
6bbda35c | 2020 | static bool mem_cgroup_reclaimable(struct mem_cgroup *memcg, bool noswap) |
4d0c066d | 2021 | { |
c0ff4b85 | 2022 | return test_mem_cgroup_node_reclaimable(memcg, 0, noswap); |
4d0c066d | 2023 | } |
889976db YH |
2024 | #endif |
2025 | ||
5660048c JW |
2026 | static int mem_cgroup_soft_reclaim(struct mem_cgroup *root_memcg, |
2027 | struct zone *zone, | |
2028 | gfp_t gfp_mask, | |
2029 | unsigned long *total_scanned) | |
6d61ef40 | 2030 | { |
9f3a0d09 | 2031 | struct mem_cgroup *victim = NULL; |
5660048c | 2032 | int total = 0; |
04046e1a | 2033 | int loop = 0; |
9d11ea9f | 2034 | unsigned long excess; |
185efc0f | 2035 | unsigned long nr_scanned; |
527a5ec9 JW |
2036 | struct mem_cgroup_reclaim_cookie reclaim = { |
2037 | .zone = zone, | |
2038 | .priority = 0, | |
2039 | }; | |
9d11ea9f | 2040 | |
c0ff4b85 | 2041 | excess = res_counter_soft_limit_excess(&root_memcg->res) >> PAGE_SHIFT; |
04046e1a | 2042 | |
4e416953 | 2043 | while (1) { |
527a5ec9 | 2044 | victim = mem_cgroup_iter(root_memcg, victim, &reclaim); |
9f3a0d09 | 2045 | if (!victim) { |
04046e1a | 2046 | loop++; |
4e416953 BS |
2047 | if (loop >= 2) { |
2048 | /* | |
2049 | * If we have not been able to reclaim | |
2050 | * anything, it might because there are | |
2051 | * no reclaimable pages under this hierarchy | |
2052 | */ | |
5660048c | 2053 | if (!total) |
4e416953 | 2054 | break; |
4e416953 | 2055 | /* |
25985edc | 2056 | * We want to do more targeted reclaim. |
4e416953 BS |
2057 | * excess >> 2 is not to excessive so as to |
2058 | * reclaim too much, nor too less that we keep | |
2059 | * coming back to reclaim from this cgroup | |
2060 | */ | |
2061 | if (total >= (excess >> 2) || | |
9f3a0d09 | 2062 | (loop > MEM_CGROUP_MAX_RECLAIM_LOOPS)) |
4e416953 | 2063 | break; |
4e416953 | 2064 | } |
9f3a0d09 | 2065 | continue; |
4e416953 | 2066 | } |
5660048c | 2067 | if (!mem_cgroup_reclaimable(victim, false)) |
6d61ef40 | 2068 | continue; |
5660048c JW |
2069 | total += mem_cgroup_shrink_node_zone(victim, gfp_mask, false, |
2070 | zone, &nr_scanned); | |
2071 | *total_scanned += nr_scanned; | |
2072 | if (!res_counter_soft_limit_excess(&root_memcg->res)) | |
9f3a0d09 | 2073 | break; |
6d61ef40 | 2074 | } |
9f3a0d09 | 2075 | mem_cgroup_iter_break(root_memcg, victim); |
04046e1a | 2076 | return total; |
6d61ef40 BS |
2077 | } |
2078 | ||
7a147e0c JW |
2079 | static DEFINE_SPINLOCK(memcg_oom_lock); |
2080 | ||
867578cb KH |
2081 | /* |
2082 | * Check OOM-Killer is already running under our hierarchy. | |
2083 | * If someone is running, return false. | |
2084 | */ | |
7a147e0c | 2085 | static bool mem_cgroup_oom_trylock(struct mem_cgroup *memcg) |
867578cb | 2086 | { |
79dfdacc | 2087 | struct mem_cgroup *iter, *failed = NULL; |
a636b327 | 2088 | |
7a147e0c JW |
2089 | spin_lock(&memcg_oom_lock); |
2090 | ||
9f3a0d09 | 2091 | for_each_mem_cgroup_tree(iter, memcg) { |
23751be0 | 2092 | if (iter->oom_lock) { |
79dfdacc MH |
2093 | /* |
2094 | * this subtree of our hierarchy is already locked | |
2095 | * so we cannot give a lock. | |
2096 | */ | |
79dfdacc | 2097 | failed = iter; |
9f3a0d09 JW |
2098 | mem_cgroup_iter_break(memcg, iter); |
2099 | break; | |
23751be0 JW |
2100 | } else |
2101 | iter->oom_lock = true; | |
7d74b06f | 2102 | } |
867578cb | 2103 | |
7a147e0c JW |
2104 | if (failed) { |
2105 | /* | |
2106 | * OK, we failed to lock the whole subtree so we have | |
2107 | * to clean up what we set up to the failing subtree | |
2108 | */ | |
2109 | for_each_mem_cgroup_tree(iter, memcg) { | |
2110 | if (iter == failed) { | |
2111 | mem_cgroup_iter_break(memcg, iter); | |
2112 | break; | |
2113 | } | |
2114 | iter->oom_lock = false; | |
79dfdacc | 2115 | } |
79dfdacc | 2116 | } |
7a147e0c JW |
2117 | |
2118 | spin_unlock(&memcg_oom_lock); | |
2119 | ||
2120 | return !failed; | |
a636b327 | 2121 | } |
0b7f569e | 2122 | |
7a147e0c | 2123 | static void mem_cgroup_oom_unlock(struct mem_cgroup *memcg) |
0b7f569e | 2124 | { |
7d74b06f KH |
2125 | struct mem_cgroup *iter; |
2126 | ||
7a147e0c | 2127 | spin_lock(&memcg_oom_lock); |
c0ff4b85 | 2128 | for_each_mem_cgroup_tree(iter, memcg) |
79dfdacc | 2129 | iter->oom_lock = false; |
7a147e0c | 2130 | spin_unlock(&memcg_oom_lock); |
79dfdacc MH |
2131 | } |
2132 | ||
c0ff4b85 | 2133 | static void mem_cgroup_mark_under_oom(struct mem_cgroup *memcg) |
79dfdacc MH |
2134 | { |
2135 | struct mem_cgroup *iter; | |
2136 | ||
c0ff4b85 | 2137 | for_each_mem_cgroup_tree(iter, memcg) |
79dfdacc MH |
2138 | atomic_inc(&iter->under_oom); |
2139 | } | |
2140 | ||
c0ff4b85 | 2141 | static void mem_cgroup_unmark_under_oom(struct mem_cgroup *memcg) |
79dfdacc MH |
2142 | { |
2143 | struct mem_cgroup *iter; | |
2144 | ||
867578cb KH |
2145 | /* |
2146 | * When a new child is created while the hierarchy is under oom, | |
2147 | * mem_cgroup_oom_lock() may not be called. We have to use | |
2148 | * atomic_add_unless() here. | |
2149 | */ | |
c0ff4b85 | 2150 | for_each_mem_cgroup_tree(iter, memcg) |
79dfdacc | 2151 | atomic_add_unless(&iter->under_oom, -1, 0); |
0b7f569e KH |
2152 | } |
2153 | ||
867578cb KH |
2154 | static DECLARE_WAIT_QUEUE_HEAD(memcg_oom_waitq); |
2155 | ||
dc98df5a | 2156 | struct oom_wait_info { |
d79154bb | 2157 | struct mem_cgroup *memcg; |
dc98df5a KH |
2158 | wait_queue_t wait; |
2159 | }; | |
2160 | ||
2161 | static int memcg_oom_wake_function(wait_queue_t *wait, | |
2162 | unsigned mode, int sync, void *arg) | |
2163 | { | |
d79154bb HD |
2164 | struct mem_cgroup *wake_memcg = (struct mem_cgroup *)arg; |
2165 | struct mem_cgroup *oom_wait_memcg; | |
dc98df5a KH |
2166 | struct oom_wait_info *oom_wait_info; |
2167 | ||
2168 | oom_wait_info = container_of(wait, struct oom_wait_info, wait); | |
d79154bb | 2169 | oom_wait_memcg = oom_wait_info->memcg; |
dc98df5a | 2170 | |
dc98df5a | 2171 | /* |
d79154bb | 2172 | * Both of oom_wait_info->memcg and wake_memcg are stable under us. |
dc98df5a KH |
2173 | * Then we can use css_is_ancestor without taking care of RCU. |
2174 | */ | |
c0ff4b85 R |
2175 | if (!mem_cgroup_same_or_subtree(oom_wait_memcg, wake_memcg) |
2176 | && !mem_cgroup_same_or_subtree(wake_memcg, oom_wait_memcg)) | |
dc98df5a | 2177 | return 0; |
dc98df5a KH |
2178 | return autoremove_wake_function(wait, mode, sync, arg); |
2179 | } | |
2180 | ||
c0ff4b85 | 2181 | static void memcg_wakeup_oom(struct mem_cgroup *memcg) |
dc98df5a | 2182 | { |
f79d6a46 | 2183 | atomic_inc(&memcg->oom_wakeups); |
c0ff4b85 R |
2184 | /* for filtering, pass "memcg" as argument. */ |
2185 | __wake_up(&memcg_oom_waitq, TASK_NORMAL, 0, memcg); | |
dc98df5a KH |
2186 | } |
2187 | ||
c0ff4b85 | 2188 | static void memcg_oom_recover(struct mem_cgroup *memcg) |
3c11ecf4 | 2189 | { |
c0ff4b85 R |
2190 | if (memcg && atomic_read(&memcg->under_oom)) |
2191 | memcg_wakeup_oom(memcg); | |
3c11ecf4 KH |
2192 | } |
2193 | ||
f79d6a46 | 2194 | static void mem_cgroup_oom(struct mem_cgroup *memcg, gfp_t mask, int order) |
0b7f569e | 2195 | { |
f79d6a46 JW |
2196 | if (!current->memcg_oom.may_oom) |
2197 | return; | |
867578cb | 2198 | /* |
f8a51179 JW |
2199 | * We are in the middle of the charge context here, so we |
2200 | * don't want to block when potentially sitting on a callstack | |
2201 | * that holds all kinds of filesystem and mm locks. | |
2202 | * | |
2203 | * Also, the caller may handle a failed allocation gracefully | |
2204 | * (like optional page cache readahead) and so an OOM killer | |
2205 | * invocation might not even be necessary. | |
2206 | * | |
2207 | * That's why we don't do anything here except remember the | |
2208 | * OOM context and then deal with it at the end of the page | |
2209 | * fault when the stack is unwound, the locks are released, | |
2210 | * and when we know whether the fault was overall successful. | |
867578cb | 2211 | */ |
f8a51179 JW |
2212 | css_get(&memcg->css); |
2213 | current->memcg_oom.memcg = memcg; | |
2214 | current->memcg_oom.gfp_mask = mask; | |
2215 | current->memcg_oom.order = order; | |
f79d6a46 JW |
2216 | } |
2217 | ||
2218 | /** | |
2219 | * mem_cgroup_oom_synchronize - complete memcg OOM handling | |
f8a51179 | 2220 | * @handle: actually kill/wait or just clean up the OOM state |
f79d6a46 | 2221 | * |
f8a51179 JW |
2222 | * This has to be called at the end of a page fault if the memcg OOM |
2223 | * handler was enabled. | |
f79d6a46 | 2224 | * |
f8a51179 | 2225 | * Memcg supports userspace OOM handling where failed allocations must |
f79d6a46 JW |
2226 | * sleep on a waitqueue until the userspace task resolves the |
2227 | * situation. Sleeping directly in the charge context with all kinds | |
2228 | * of locks held is not a good idea, instead we remember an OOM state | |
2229 | * in the task and mem_cgroup_oom_synchronize() has to be called at | |
f8a51179 | 2230 | * the end of the page fault to complete the OOM handling. |
f79d6a46 JW |
2231 | * |
2232 | * Returns %true if an ongoing memcg OOM situation was detected and | |
f8a51179 | 2233 | * completed, %false otherwise. |
f79d6a46 | 2234 | */ |
f8a51179 | 2235 | bool mem_cgroup_oom_synchronize(bool handle) |
f79d6a46 | 2236 | { |
f8a51179 | 2237 | struct mem_cgroup *memcg = current->memcg_oom.memcg; |
f79d6a46 | 2238 | struct oom_wait_info owait; |
f8a51179 | 2239 | bool locked; |
f79d6a46 JW |
2240 | |
2241 | /* OOM is global, do not handle */ | |
f79d6a46 | 2242 | if (!memcg) |
f8a51179 | 2243 | return false; |
f79d6a46 | 2244 | |
f8a51179 JW |
2245 | if (!handle) |
2246 | goto cleanup; | |
f79d6a46 JW |
2247 | |
2248 | owait.memcg = memcg; | |
2249 | owait.wait.flags = 0; | |
2250 | owait.wait.func = memcg_oom_wake_function; | |
2251 | owait.wait.private = current; | |
2252 | INIT_LIST_HEAD(&owait.wait.task_list); | |
867578cb | 2253 | |
f79d6a46 | 2254 | prepare_to_wait(&memcg_oom_waitq, &owait.wait, TASK_KILLABLE); |
f8a51179 JW |
2255 | mem_cgroup_mark_under_oom(memcg); |
2256 | ||
2257 | locked = mem_cgroup_oom_trylock(memcg); | |
2258 | ||
2259 | if (locked) | |
2260 | mem_cgroup_oom_notify(memcg); | |
2261 | ||
2262 | if (locked && !memcg->oom_kill_disable) { | |
2263 | mem_cgroup_unmark_under_oom(memcg); | |
2264 | finish_wait(&memcg_oom_waitq, &owait.wait); | |
2265 | mem_cgroup_out_of_memory(memcg, current->memcg_oom.gfp_mask, | |
2266 | current->memcg_oom.order); | |
2267 | } else { | |
f79d6a46 | 2268 | schedule(); |
f8a51179 JW |
2269 | mem_cgroup_unmark_under_oom(memcg); |
2270 | finish_wait(&memcg_oom_waitq, &owait.wait); | |
2271 | } | |
2272 | ||
2273 | if (locked) { | |
7a147e0c JW |
2274 | mem_cgroup_oom_unlock(memcg); |
2275 | /* | |
2276 | * There is no guarantee that an OOM-lock contender | |
2277 | * sees the wakeups triggered by the OOM kill | |
2278 | * uncharges. Wake any sleepers explicitely. | |
2279 | */ | |
2280 | memcg_oom_recover(memcg); | |
2281 | } | |
f8a51179 JW |
2282 | cleanup: |
2283 | current->memcg_oom.memcg = NULL; | |
f79d6a46 | 2284 | css_put(&memcg->css); |
867578cb | 2285 | return true; |
0b7f569e KH |
2286 | } |
2287 | ||
d69b042f BS |
2288 | /* |
2289 | * Currently used to update mapped file statistics, but the routine can be | |
2290 | * generalized to update other statistics as well. | |
32047e2a KH |
2291 | * |
2292 | * Notes: Race condition | |
2293 | * | |
2294 | * We usually use page_cgroup_lock() for accessing page_cgroup member but | |
2295 | * it tends to be costly. But considering some conditions, we doesn't need | |
2296 | * to do so _always_. | |
2297 | * | |
2298 | * Considering "charge", lock_page_cgroup() is not required because all | |
2299 | * file-stat operations happen after a page is attached to radix-tree. There | |
2300 | * are no race with "charge". | |
2301 | * | |
2302 | * Considering "uncharge", we know that memcg doesn't clear pc->mem_cgroup | |
2303 | * at "uncharge" intentionally. So, we always see valid pc->mem_cgroup even | |
2304 | * if there are race with "uncharge". Statistics itself is properly handled | |
2305 | * by flags. | |
2306 | * | |
2307 | * Considering "move", this is an only case we see a race. To make the race | |
619d094b KH |
2308 | * small, we check mm->moving_account and detect there are possibility of race |
2309 | * If there is, we take a lock. | |
d69b042f | 2310 | */ |
26174efd | 2311 | |
89c06bd5 KH |
2312 | void __mem_cgroup_begin_update_page_stat(struct page *page, |
2313 | bool *locked, unsigned long *flags) | |
2314 | { | |
2315 | struct mem_cgroup *memcg; | |
2316 | struct page_cgroup *pc; | |
2317 | ||
2318 | pc = lookup_page_cgroup(page); | |
2319 | again: | |
2320 | memcg = pc->mem_cgroup; | |
2321 | if (unlikely(!memcg || !PageCgroupUsed(pc))) | |
2322 | return; | |
2323 | /* | |
2324 | * If this memory cgroup is not under account moving, we don't | |
da92c47d | 2325 | * need to take move_lock_mem_cgroup(). Because we already hold |
89c06bd5 | 2326 | * rcu_read_lock(), any calls to move_account will be delayed until |
13fd1dd9 | 2327 | * rcu_read_unlock() if mem_cgroup_stolen() == true. |
89c06bd5 | 2328 | */ |
13fd1dd9 | 2329 | if (!mem_cgroup_stolen(memcg)) |
89c06bd5 KH |
2330 | return; |
2331 | ||
2332 | move_lock_mem_cgroup(memcg, flags); | |
2333 | if (memcg != pc->mem_cgroup || !PageCgroupUsed(pc)) { | |
2334 | move_unlock_mem_cgroup(memcg, flags); | |
2335 | goto again; | |
2336 | } | |
2337 | *locked = true; | |
2338 | } | |
2339 | ||
2340 | void __mem_cgroup_end_update_page_stat(struct page *page, unsigned long *flags) | |
2341 | { | |
2342 | struct page_cgroup *pc = lookup_page_cgroup(page); | |
2343 | ||
2344 | /* | |
2345 | * It's guaranteed that pc->mem_cgroup never changes while | |
2346 | * lock is held because a routine modifies pc->mem_cgroup | |
da92c47d | 2347 | * should take move_lock_mem_cgroup(). |
89c06bd5 KH |
2348 | */ |
2349 | move_unlock_mem_cgroup(pc->mem_cgroup, flags); | |
2350 | } | |
2351 | ||
2a7106f2 GT |
2352 | void mem_cgroup_update_page_stat(struct page *page, |
2353 | enum mem_cgroup_page_stat_item idx, int val) | |
d69b042f | 2354 | { |
c0ff4b85 | 2355 | struct mem_cgroup *memcg; |
32047e2a | 2356 | struct page_cgroup *pc = lookup_page_cgroup(page); |
dbd4ea78 | 2357 | unsigned long uninitialized_var(flags); |
d69b042f | 2358 | |
cfa44946 | 2359 | if (mem_cgroup_disabled()) |
d69b042f | 2360 | return; |
89c06bd5 | 2361 | |
c0ff4b85 R |
2362 | memcg = pc->mem_cgroup; |
2363 | if (unlikely(!memcg || !PageCgroupUsed(pc))) | |
89c06bd5 | 2364 | return; |
26174efd | 2365 | |
26174efd | 2366 | switch (idx) { |
2a7106f2 | 2367 | case MEMCG_NR_FILE_MAPPED: |
2a7106f2 | 2368 | idx = MEM_CGROUP_STAT_FILE_MAPPED; |
26174efd KH |
2369 | break; |
2370 | default: | |
2371 | BUG(); | |
8725d541 | 2372 | } |
d69b042f | 2373 | |
c0ff4b85 | 2374 | this_cpu_add(memcg->stat->count[idx], val); |
d69b042f | 2375 | } |
26174efd | 2376 | |
cdec2e42 KH |
2377 | /* |
2378 | * size of first charge trial. "32" comes from vmscan.c's magic value. | |
2379 | * TODO: maybe necessary to use big numbers in big irons. | |
2380 | */ | |
7ec99d62 | 2381 | #define CHARGE_BATCH 32U |
cdec2e42 KH |
2382 | struct memcg_stock_pcp { |
2383 | struct mem_cgroup *cached; /* this never be root cgroup */ | |
11c9ea4e | 2384 | unsigned int nr_pages; |
cdec2e42 | 2385 | struct work_struct work; |
26fe6168 | 2386 | unsigned long flags; |
a0db00fc | 2387 | #define FLUSHING_CACHED_CHARGE 0 |
cdec2e42 KH |
2388 | }; |
2389 | static DEFINE_PER_CPU(struct memcg_stock_pcp, memcg_stock); | |
9f50fad6 | 2390 | static DEFINE_MUTEX(percpu_charge_mutex); |
cdec2e42 | 2391 | |
a0956d54 SS |
2392 | /** |
2393 | * consume_stock: Try to consume stocked charge on this cpu. | |
2394 | * @memcg: memcg to consume from. | |
2395 | * @nr_pages: how many pages to charge. | |
2396 | * | |
2397 | * The charges will only happen if @memcg matches the current cpu's memcg | |
2398 | * stock, and at least @nr_pages are available in that stock. Failure to | |
2399 | * service an allocation will refill the stock. | |
2400 | * | |
2401 | * returns true if successful, false otherwise. | |
cdec2e42 | 2402 | */ |
a0956d54 | 2403 | static bool consume_stock(struct mem_cgroup *memcg, unsigned int nr_pages) |
cdec2e42 KH |
2404 | { |
2405 | struct memcg_stock_pcp *stock; | |
2406 | bool ret = true; | |
2407 | ||
a0956d54 SS |
2408 | if (nr_pages > CHARGE_BATCH) |
2409 | return false; | |
2410 | ||
cdec2e42 | 2411 | stock = &get_cpu_var(memcg_stock); |
a0956d54 SS |
2412 | if (memcg == stock->cached && stock->nr_pages >= nr_pages) |
2413 | stock->nr_pages -= nr_pages; | |
cdec2e42 KH |
2414 | else /* need to call res_counter_charge */ |
2415 | ret = false; | |
2416 | put_cpu_var(memcg_stock); | |
2417 | return ret; | |
2418 | } | |
2419 | ||
2420 | /* | |
2421 | * Returns stocks cached in percpu to res_counter and reset cached information. | |
2422 | */ | |
2423 | static void drain_stock(struct memcg_stock_pcp *stock) | |
2424 | { | |
2425 | struct mem_cgroup *old = stock->cached; | |
2426 | ||
11c9ea4e JW |
2427 | if (stock->nr_pages) { |
2428 | unsigned long bytes = stock->nr_pages * PAGE_SIZE; | |
2429 | ||
2430 | res_counter_uncharge(&old->res, bytes); | |
cdec2e42 | 2431 | if (do_swap_account) |
11c9ea4e JW |
2432 | res_counter_uncharge(&old->memsw, bytes); |
2433 | stock->nr_pages = 0; | |
cdec2e42 KH |
2434 | } |
2435 | stock->cached = NULL; | |
cdec2e42 KH |
2436 | } |
2437 | ||
2438 | /* | |
2439 | * This must be called under preempt disabled or must be called by | |
2440 | * a thread which is pinned to local cpu. | |
2441 | */ | |
2442 | static void drain_local_stock(struct work_struct *dummy) | |
2443 | { | |
2444 | struct memcg_stock_pcp *stock = &__get_cpu_var(memcg_stock); | |
2445 | drain_stock(stock); | |
26fe6168 | 2446 | clear_bit(FLUSHING_CACHED_CHARGE, &stock->flags); |
cdec2e42 KH |
2447 | } |
2448 | ||
e4777496 MH |
2449 | static void __init memcg_stock_init(void) |
2450 | { | |
2451 | int cpu; | |
2452 | ||
2453 | for_each_possible_cpu(cpu) { | |
2454 | struct memcg_stock_pcp *stock = | |
2455 | &per_cpu(memcg_stock, cpu); | |
2456 | INIT_WORK(&stock->work, drain_local_stock); | |
2457 | } | |
2458 | } | |
2459 | ||
cdec2e42 KH |
2460 | /* |
2461 | * Cache charges(val) which is from res_counter, to local per_cpu area. | |
320cc51d | 2462 | * This will be consumed by consume_stock() function, later. |
cdec2e42 | 2463 | */ |
c0ff4b85 | 2464 | static void refill_stock(struct mem_cgroup *memcg, unsigned int nr_pages) |
cdec2e42 KH |
2465 | { |
2466 | struct memcg_stock_pcp *stock = &get_cpu_var(memcg_stock); | |
2467 | ||
c0ff4b85 | 2468 | if (stock->cached != memcg) { /* reset if necessary */ |
cdec2e42 | 2469 | drain_stock(stock); |
c0ff4b85 | 2470 | stock->cached = memcg; |
cdec2e42 | 2471 | } |
11c9ea4e | 2472 | stock->nr_pages += nr_pages; |
cdec2e42 KH |
2473 | put_cpu_var(memcg_stock); |
2474 | } | |
2475 | ||
2476 | /* | |
c0ff4b85 | 2477 | * Drains all per-CPU charge caches for given root_memcg resp. subtree |
d38144b7 MH |
2478 | * of the hierarchy under it. sync flag says whether we should block |
2479 | * until the work is done. | |
cdec2e42 | 2480 | */ |
c0ff4b85 | 2481 | static void drain_all_stock(struct mem_cgroup *root_memcg, bool sync) |
cdec2e42 | 2482 | { |
26fe6168 | 2483 | int cpu, curcpu; |
d38144b7 | 2484 | |
cdec2e42 | 2485 | /* Notify other cpus that system-wide "drain" is running */ |
cdec2e42 | 2486 | get_online_cpus(); |
5af12d0e | 2487 | curcpu = get_cpu(); |
cdec2e42 KH |
2488 | for_each_online_cpu(cpu) { |
2489 | struct memcg_stock_pcp *stock = &per_cpu(memcg_stock, cpu); | |
c0ff4b85 | 2490 | struct mem_cgroup *memcg; |
26fe6168 | 2491 | |
c0ff4b85 R |
2492 | memcg = stock->cached; |
2493 | if (!memcg || !stock->nr_pages) | |
26fe6168 | 2494 | continue; |
c0ff4b85 | 2495 | if (!mem_cgroup_same_or_subtree(root_memcg, memcg)) |
3e92041d | 2496 | continue; |
d1a05b69 MH |
2497 | if (!test_and_set_bit(FLUSHING_CACHED_CHARGE, &stock->flags)) { |
2498 | if (cpu == curcpu) | |
2499 | drain_local_stock(&stock->work); | |
2500 | else | |
2501 | schedule_work_on(cpu, &stock->work); | |
2502 | } | |
cdec2e42 | 2503 | } |
5af12d0e | 2504 | put_cpu(); |
d38144b7 MH |
2505 | |
2506 | if (!sync) | |
2507 | goto out; | |
2508 | ||
2509 | for_each_online_cpu(cpu) { | |
2510 | struct memcg_stock_pcp *stock = &per_cpu(memcg_stock, cpu); | |
9f50fad6 | 2511 | if (test_bit(FLUSHING_CACHED_CHARGE, &stock->flags)) |
d38144b7 MH |
2512 | flush_work(&stock->work); |
2513 | } | |
2514 | out: | |
cdec2e42 | 2515 | put_online_cpus(); |
d38144b7 MH |
2516 | } |
2517 | ||
2518 | /* | |
2519 | * Tries to drain stocked charges in other cpus. This function is asynchronous | |
2520 | * and just put a work per cpu for draining localy on each cpu. Caller can | |
2521 | * expects some charges will be back to res_counter later but cannot wait for | |
2522 | * it. | |
2523 | */ | |
c0ff4b85 | 2524 | static void drain_all_stock_async(struct mem_cgroup *root_memcg) |
d38144b7 | 2525 | { |
9f50fad6 MH |
2526 | /* |
2527 | * If someone calls draining, avoid adding more kworker runs. | |
2528 | */ | |
2529 | if (!mutex_trylock(&percpu_charge_mutex)) | |
2530 | return; | |
c0ff4b85 | 2531 | drain_all_stock(root_memcg, false); |
9f50fad6 | 2532 | mutex_unlock(&percpu_charge_mutex); |
cdec2e42 KH |
2533 | } |
2534 | ||
2535 | /* This is a synchronous drain interface. */ | |
c0ff4b85 | 2536 | static void drain_all_stock_sync(struct mem_cgroup *root_memcg) |
cdec2e42 KH |
2537 | { |
2538 | /* called when force_empty is called */ | |
9f50fad6 | 2539 | mutex_lock(&percpu_charge_mutex); |
c0ff4b85 | 2540 | drain_all_stock(root_memcg, true); |
9f50fad6 | 2541 | mutex_unlock(&percpu_charge_mutex); |
cdec2e42 KH |
2542 | } |
2543 | ||
711d3d2c KH |
2544 | /* |
2545 | * This function drains percpu counter value from DEAD cpu and | |
2546 | * move it to local cpu. Note that this function can be preempted. | |
2547 | */ | |
c0ff4b85 | 2548 | static void mem_cgroup_drain_pcp_counter(struct mem_cgroup *memcg, int cpu) |
711d3d2c KH |
2549 | { |
2550 | int i; | |
2551 | ||
c0ff4b85 | 2552 | spin_lock(&memcg->pcp_counter_lock); |
6104621d | 2553 | for (i = 0; i < MEM_CGROUP_STAT_NSTATS; i++) { |
c0ff4b85 | 2554 | long x = per_cpu(memcg->stat->count[i], cpu); |
711d3d2c | 2555 | |
c0ff4b85 R |
2556 | per_cpu(memcg->stat->count[i], cpu) = 0; |
2557 | memcg->nocpu_base.count[i] += x; | |
711d3d2c | 2558 | } |
e9f8974f | 2559 | for (i = 0; i < MEM_CGROUP_EVENTS_NSTATS; i++) { |
c0ff4b85 | 2560 | unsigned long x = per_cpu(memcg->stat->events[i], cpu); |
e9f8974f | 2561 | |
c0ff4b85 R |
2562 | per_cpu(memcg->stat->events[i], cpu) = 0; |
2563 | memcg->nocpu_base.events[i] += x; | |
e9f8974f | 2564 | } |
c0ff4b85 | 2565 | spin_unlock(&memcg->pcp_counter_lock); |
711d3d2c KH |
2566 | } |
2567 | ||
2568 | static int __cpuinit memcg_cpu_hotplug_callback(struct notifier_block *nb, | |
cdec2e42 KH |
2569 | unsigned long action, |
2570 | void *hcpu) | |
2571 | { | |
2572 | int cpu = (unsigned long)hcpu; | |
2573 | struct memcg_stock_pcp *stock; | |
711d3d2c | 2574 | struct mem_cgroup *iter; |
cdec2e42 | 2575 | |
619d094b | 2576 | if (action == CPU_ONLINE) |
1489ebad | 2577 | return NOTIFY_OK; |
1489ebad | 2578 | |
d833049b | 2579 | if (action != CPU_DEAD && action != CPU_DEAD_FROZEN) |
cdec2e42 | 2580 | return NOTIFY_OK; |
711d3d2c | 2581 | |
9f3a0d09 | 2582 | for_each_mem_cgroup(iter) |
711d3d2c KH |
2583 | mem_cgroup_drain_pcp_counter(iter, cpu); |
2584 | ||
cdec2e42 KH |
2585 | stock = &per_cpu(memcg_stock, cpu); |
2586 | drain_stock(stock); | |
2587 | return NOTIFY_OK; | |
2588 | } | |
2589 | ||
4b534334 KH |
2590 | |
2591 | /* See __mem_cgroup_try_charge() for details */ | |
2592 | enum { | |
2593 | CHARGE_OK, /* success */ | |
2594 | CHARGE_RETRY, /* need to retry but retry is not bad */ | |
2595 | CHARGE_NOMEM, /* we can't do more. return -ENOMEM */ | |
2596 | CHARGE_WOULDBLOCK, /* GFP_WAIT wasn't set and no enough res. */ | |
4b534334 KH |
2597 | }; |
2598 | ||
c0ff4b85 | 2599 | static int mem_cgroup_do_charge(struct mem_cgroup *memcg, gfp_t gfp_mask, |
4c9c5359 | 2600 | unsigned int nr_pages, unsigned int min_pages, |
f79d6a46 | 2601 | bool invoke_oom) |
4b534334 | 2602 | { |
7ec99d62 | 2603 | unsigned long csize = nr_pages * PAGE_SIZE; |
4b534334 KH |
2604 | struct mem_cgroup *mem_over_limit; |
2605 | struct res_counter *fail_res; | |
2606 | unsigned long flags = 0; | |
2607 | int ret; | |
2608 | ||
c0ff4b85 | 2609 | ret = res_counter_charge(&memcg->res, csize, &fail_res); |
4b534334 KH |
2610 | |
2611 | if (likely(!ret)) { | |
2612 | if (!do_swap_account) | |
2613 | return CHARGE_OK; | |
c0ff4b85 | 2614 | ret = res_counter_charge(&memcg->memsw, csize, &fail_res); |
4b534334 KH |
2615 | if (likely(!ret)) |
2616 | return CHARGE_OK; | |
2617 | ||
c0ff4b85 | 2618 | res_counter_uncharge(&memcg->res, csize); |
4b534334 KH |
2619 | mem_over_limit = mem_cgroup_from_res_counter(fail_res, memsw); |
2620 | flags |= MEM_CGROUP_RECLAIM_NOSWAP; | |
2621 | } else | |
2622 | mem_over_limit = mem_cgroup_from_res_counter(fail_res, res); | |
9221edb7 | 2623 | /* |
9221edb7 JW |
2624 | * Never reclaim on behalf of optional batching, retry with a |
2625 | * single page instead. | |
2626 | */ | |
4c9c5359 | 2627 | if (nr_pages > min_pages) |
4b534334 KH |
2628 | return CHARGE_RETRY; |
2629 | ||
2630 | if (!(gfp_mask & __GFP_WAIT)) | |
2631 | return CHARGE_WOULDBLOCK; | |
2632 | ||
4c9c5359 SS |
2633 | if (gfp_mask & __GFP_NORETRY) |
2634 | return CHARGE_NOMEM; | |
2635 | ||
5660048c | 2636 | ret = mem_cgroup_reclaim(mem_over_limit, gfp_mask, flags); |
7ec99d62 | 2637 | if (mem_cgroup_margin(mem_over_limit) >= nr_pages) |
19942822 | 2638 | return CHARGE_RETRY; |
4b534334 | 2639 | /* |
19942822 JW |
2640 | * Even though the limit is exceeded at this point, reclaim |
2641 | * may have been able to free some pages. Retry the charge | |
2642 | * before killing the task. | |
2643 | * | |
2644 | * Only for regular pages, though: huge pages are rather | |
2645 | * unlikely to succeed so close to the limit, and we fall back | |
2646 | * to regular pages anyway in case of failure. | |
4b534334 | 2647 | */ |
4c9c5359 | 2648 | if (nr_pages <= (1 << PAGE_ALLOC_COSTLY_ORDER) && ret) |
4b534334 KH |
2649 | return CHARGE_RETRY; |
2650 | ||
2651 | /* | |
2652 | * At task move, charge accounts can be doubly counted. So, it's | |
2653 | * better to wait until the end of task_move if something is going on. | |
2654 | */ | |
2655 | if (mem_cgroup_wait_acct_move(mem_over_limit)) | |
2656 | return CHARGE_RETRY; | |
2657 | ||
f79d6a46 JW |
2658 | if (invoke_oom) |
2659 | mem_cgroup_oom(mem_over_limit, gfp_mask, get_order(csize)); | |
4b534334 | 2660 | |
f79d6a46 | 2661 | return CHARGE_NOMEM; |
4b534334 KH |
2662 | } |
2663 | ||
f817ed48 | 2664 | /* |
38c5d72f KH |
2665 | * __mem_cgroup_try_charge() does |
2666 | * 1. detect memcg to be charged against from passed *mm and *ptr, | |
2667 | * 2. update res_counter | |
2668 | * 3. call memory reclaim if necessary. | |
2669 | * | |
2670 | * In some special case, if the task is fatal, fatal_signal_pending() or | |
2671 | * has TIF_MEMDIE, this function returns -EINTR while writing root_mem_cgroup | |
2672 | * to *ptr. There are two reasons for this. 1: fatal threads should quit as soon | |
2673 | * as possible without any hazards. 2: all pages should have a valid | |
2674 | * pc->mem_cgroup. If mm is NULL and the caller doesn't pass a valid memcg | |
2675 | * pointer, that is treated as a charge to root_mem_cgroup. | |
2676 | * | |
2677 | * So __mem_cgroup_try_charge() will return | |
2678 | * 0 ... on success, filling *ptr with a valid memcg pointer. | |
2679 | * -ENOMEM ... charge failure because of resource limits. | |
2680 | * -EINTR ... if thread is fatal. *ptr is filled with root_mem_cgroup. | |
2681 | * | |
2682 | * Unlike the exported interface, an "oom" parameter is added. if oom==true, | |
2683 | * the oom-killer can be invoked. | |
8a9f3ccd | 2684 | */ |
f817ed48 | 2685 | static int __mem_cgroup_try_charge(struct mm_struct *mm, |
ec168510 | 2686 | gfp_t gfp_mask, |
7ec99d62 | 2687 | unsigned int nr_pages, |
c0ff4b85 | 2688 | struct mem_cgroup **ptr, |
7ec99d62 | 2689 | bool oom) |
8a9f3ccd | 2690 | { |
7ec99d62 | 2691 | unsigned int batch = max(CHARGE_BATCH, nr_pages); |
4b534334 | 2692 | int nr_oom_retries = MEM_CGROUP_RECLAIM_RETRIES; |
c0ff4b85 | 2693 | struct mem_cgroup *memcg = NULL; |
4b534334 | 2694 | int ret; |
a636b327 | 2695 | |
867578cb KH |
2696 | /* |
2697 | * Unlike gloval-vm's OOM-kill, we're not in memory shortage | |
2698 | * in system level. So, allow to go ahead dying process in addition to | |
2699 | * MEMDIE process. | |
2700 | */ | |
2701 | if (unlikely(test_thread_flag(TIF_MEMDIE) | |
2702 | || fatal_signal_pending(current))) | |
2703 | goto bypass; | |
a636b327 | 2704 | |
f8a51179 JW |
2705 | if (unlikely(task_in_memcg_oom(current))) |
2706 | goto bypass; | |
2707 | ||
8a9f3ccd | 2708 | /* |
3be91277 HD |
2709 | * We always charge the cgroup the mm_struct belongs to. |
2710 | * The mm_struct's mem_cgroup changes on task migration if the | |
8a9f3ccd | 2711 | * thread group leader migrates. It's possible that mm is not |
24467cac | 2712 | * set, if so charge the root memcg (happens for pagecache usage). |
8a9f3ccd | 2713 | */ |
c0ff4b85 | 2714 | if (!*ptr && !mm) |
38c5d72f | 2715 | *ptr = root_mem_cgroup; |
f75ca962 | 2716 | again: |
c0ff4b85 R |
2717 | if (*ptr) { /* css should be a valid one */ |
2718 | memcg = *ptr; | |
c0ff4b85 | 2719 | if (mem_cgroup_is_root(memcg)) |
f75ca962 | 2720 | goto done; |
a0956d54 | 2721 | if (consume_stock(memcg, nr_pages)) |
f75ca962 | 2722 | goto done; |
c0ff4b85 | 2723 | css_get(&memcg->css); |
4b534334 | 2724 | } else { |
f75ca962 | 2725 | struct task_struct *p; |
54595fe2 | 2726 | |
f75ca962 KH |
2727 | rcu_read_lock(); |
2728 | p = rcu_dereference(mm->owner); | |
f75ca962 | 2729 | /* |
ebb76ce1 | 2730 | * Because we don't have task_lock(), "p" can exit. |
c0ff4b85 | 2731 | * In that case, "memcg" can point to root or p can be NULL with |
ebb76ce1 KH |
2732 | * race with swapoff. Then, we have small risk of mis-accouning. |
2733 | * But such kind of mis-account by race always happens because | |
2734 | * we don't have cgroup_mutex(). It's overkill and we allo that | |
2735 | * small race, here. | |
2736 | * (*) swapoff at el will charge against mm-struct not against | |
2737 | * task-struct. So, mm->owner can be NULL. | |
f75ca962 | 2738 | */ |
c0ff4b85 | 2739 | memcg = mem_cgroup_from_task(p); |
38c5d72f KH |
2740 | if (!memcg) |
2741 | memcg = root_mem_cgroup; | |
2742 | if (mem_cgroup_is_root(memcg)) { | |
f75ca962 KH |
2743 | rcu_read_unlock(); |
2744 | goto done; | |
2745 | } | |
a0956d54 | 2746 | if (consume_stock(memcg, nr_pages)) { |
f75ca962 KH |
2747 | /* |
2748 | * It seems dagerous to access memcg without css_get(). | |
2749 | * But considering how consume_stok works, it's not | |
2750 | * necessary. If consume_stock success, some charges | |
2751 | * from this memcg are cached on this cpu. So, we | |
2752 | * don't need to call css_get()/css_tryget() before | |
2753 | * calling consume_stock(). | |
2754 | */ | |
2755 | rcu_read_unlock(); | |
2756 | goto done; | |
2757 | } | |
2758 | /* after here, we may be blocked. we need to get refcnt */ | |
c0ff4b85 | 2759 | if (!css_tryget(&memcg->css)) { |
f75ca962 KH |
2760 | rcu_read_unlock(); |
2761 | goto again; | |
2762 | } | |
2763 | rcu_read_unlock(); | |
2764 | } | |
8a9f3ccd | 2765 | |
4b534334 | 2766 | do { |
f79d6a46 | 2767 | bool invoke_oom = oom && !nr_oom_retries; |
7a81b88c | 2768 | |
4b534334 | 2769 | /* If killed, bypass charge */ |
f75ca962 | 2770 | if (fatal_signal_pending(current)) { |
c0ff4b85 | 2771 | css_put(&memcg->css); |
4b534334 | 2772 | goto bypass; |
f75ca962 | 2773 | } |
6d61ef40 | 2774 | |
f79d6a46 JW |
2775 | ret = mem_cgroup_do_charge(memcg, gfp_mask, batch, |
2776 | nr_pages, invoke_oom); | |
4b534334 KH |
2777 | switch (ret) { |
2778 | case CHARGE_OK: | |
2779 | break; | |
2780 | case CHARGE_RETRY: /* not in OOM situation but retry */ | |
7ec99d62 | 2781 | batch = nr_pages; |
c0ff4b85 R |
2782 | css_put(&memcg->css); |
2783 | memcg = NULL; | |
f75ca962 | 2784 | goto again; |
4b534334 | 2785 | case CHARGE_WOULDBLOCK: /* !__GFP_WAIT */ |
c0ff4b85 | 2786 | css_put(&memcg->css); |
4b534334 KH |
2787 | goto nomem; |
2788 | case CHARGE_NOMEM: /* OOM routine works */ | |
f79d6a46 | 2789 | if (!oom || invoke_oom) { |
c0ff4b85 | 2790 | css_put(&memcg->css); |
867578cb | 2791 | goto nomem; |
f75ca962 | 2792 | } |
4b534334 KH |
2793 | nr_oom_retries--; |
2794 | break; | |
66e1707b | 2795 | } |
4b534334 KH |
2796 | } while (ret != CHARGE_OK); |
2797 | ||
7ec99d62 | 2798 | if (batch > nr_pages) |
c0ff4b85 R |
2799 | refill_stock(memcg, batch - nr_pages); |
2800 | css_put(&memcg->css); | |
0c3e73e8 | 2801 | done: |
c0ff4b85 | 2802 | *ptr = memcg; |
7a81b88c KH |
2803 | return 0; |
2804 | nomem: | |
c0ff4b85 | 2805 | *ptr = NULL; |
7a81b88c | 2806 | return -ENOMEM; |
867578cb | 2807 | bypass: |
38c5d72f KH |
2808 | *ptr = root_mem_cgroup; |
2809 | return -EINTR; | |
7a81b88c | 2810 | } |
8a9f3ccd | 2811 | |
a3032a2c DN |
2812 | /* |
2813 | * Somemtimes we have to undo a charge we got by try_charge(). | |
2814 | * This function is for that and do uncharge, put css's refcnt. | |
2815 | * gotten by try_charge(). | |
2816 | */ | |
c0ff4b85 | 2817 | static void __mem_cgroup_cancel_charge(struct mem_cgroup *memcg, |
e7018b8d | 2818 | unsigned int nr_pages) |
a3032a2c | 2819 | { |
c0ff4b85 | 2820 | if (!mem_cgroup_is_root(memcg)) { |
e7018b8d JW |
2821 | unsigned long bytes = nr_pages * PAGE_SIZE; |
2822 | ||
c0ff4b85 | 2823 | res_counter_uncharge(&memcg->res, bytes); |
a3032a2c | 2824 | if (do_swap_account) |
c0ff4b85 | 2825 | res_counter_uncharge(&memcg->memsw, bytes); |
a3032a2c | 2826 | } |
854ffa8d DN |
2827 | } |
2828 | ||
d01dd17f KH |
2829 | /* |
2830 | * Cancel chrages in this cgroup....doesn't propagate to parent cgroup. | |
2831 | * This is useful when moving usage to parent cgroup. | |
2832 | */ | |
2833 | static void __mem_cgroup_cancel_local_charge(struct mem_cgroup *memcg, | |
2834 | unsigned int nr_pages) | |
2835 | { | |
2836 | unsigned long bytes = nr_pages * PAGE_SIZE; | |
2837 | ||
2838 | if (mem_cgroup_is_root(memcg)) | |
2839 | return; | |
2840 | ||
2841 | res_counter_uncharge_until(&memcg->res, memcg->res.parent, bytes); | |
2842 | if (do_swap_account) | |
2843 | res_counter_uncharge_until(&memcg->memsw, | |
2844 | memcg->memsw.parent, bytes); | |
2845 | } | |
2846 | ||
a3b2d692 KH |
2847 | /* |
2848 | * A helper function to get mem_cgroup from ID. must be called under | |
e9316080 TH |
2849 | * rcu_read_lock(). The caller is responsible for calling css_tryget if |
2850 | * the mem_cgroup is used for charging. (dropping refcnt from swap can be | |
2851 | * called against removed memcg.) | |
a3b2d692 KH |
2852 | */ |
2853 | static struct mem_cgroup *mem_cgroup_lookup(unsigned short id) | |
2854 | { | |
2855 | struct cgroup_subsys_state *css; | |
2856 | ||
2857 | /* ID 0 is unused ID */ | |
2858 | if (!id) | |
2859 | return NULL; | |
2860 | css = css_lookup(&mem_cgroup_subsys, id); | |
2861 | if (!css) | |
2862 | return NULL; | |
b2145145 | 2863 | return mem_cgroup_from_css(css); |
a3b2d692 KH |
2864 | } |
2865 | ||
e42d9d5d | 2866 | struct mem_cgroup *try_get_mem_cgroup_from_page(struct page *page) |
b5a84319 | 2867 | { |
c0ff4b85 | 2868 | struct mem_cgroup *memcg = NULL; |
3c776e64 | 2869 | struct page_cgroup *pc; |
a3b2d692 | 2870 | unsigned short id; |
b5a84319 KH |
2871 | swp_entry_t ent; |
2872 | ||
3c776e64 DN |
2873 | VM_BUG_ON(!PageLocked(page)); |
2874 | ||
3c776e64 | 2875 | pc = lookup_page_cgroup(page); |
c0bd3f63 | 2876 | lock_page_cgroup(pc); |
a3b2d692 | 2877 | if (PageCgroupUsed(pc)) { |
c0ff4b85 R |
2878 | memcg = pc->mem_cgroup; |
2879 | if (memcg && !css_tryget(&memcg->css)) | |
2880 | memcg = NULL; | |
e42d9d5d | 2881 | } else if (PageSwapCache(page)) { |
3c776e64 | 2882 | ent.val = page_private(page); |
9fb4b7cc | 2883 | id = lookup_swap_cgroup_id(ent); |
a3b2d692 | 2884 | rcu_read_lock(); |
c0ff4b85 R |
2885 | memcg = mem_cgroup_lookup(id); |
2886 | if (memcg && !css_tryget(&memcg->css)) | |
2887 | memcg = NULL; | |
a3b2d692 | 2888 | rcu_read_unlock(); |
3c776e64 | 2889 | } |
c0bd3f63 | 2890 | unlock_page_cgroup(pc); |
c0ff4b85 | 2891 | return memcg; |
b5a84319 KH |
2892 | } |
2893 | ||
c0ff4b85 | 2894 | static void __mem_cgroup_commit_charge(struct mem_cgroup *memcg, |
5564e88b | 2895 | struct page *page, |
7ec99d62 | 2896 | unsigned int nr_pages, |
9ce70c02 HD |
2897 | enum charge_type ctype, |
2898 | bool lrucare) | |
7a81b88c | 2899 | { |
ce587e65 | 2900 | struct page_cgroup *pc = lookup_page_cgroup(page); |
9ce70c02 | 2901 | struct zone *uninitialized_var(zone); |
fa9add64 | 2902 | struct lruvec *lruvec; |
9ce70c02 | 2903 | bool was_on_lru = false; |
b2402857 | 2904 | bool anon; |
9ce70c02 | 2905 | |
ca3e0214 | 2906 | lock_page_cgroup(pc); |
90deb788 | 2907 | VM_BUG_ON(PageCgroupUsed(pc)); |
ca3e0214 KH |
2908 | /* |
2909 | * we don't need page_cgroup_lock about tail pages, becase they are not | |
2910 | * accessed by any other context at this point. | |
2911 | */ | |
9ce70c02 HD |
2912 | |
2913 | /* | |
2914 | * In some cases, SwapCache and FUSE(splice_buf->radixtree), the page | |
2915 | * may already be on some other mem_cgroup's LRU. Take care of it. | |
2916 | */ | |
2917 | if (lrucare) { | |
2918 | zone = page_zone(page); | |
2919 | spin_lock_irq(&zone->lru_lock); | |
2920 | if (PageLRU(page)) { | |
fa9add64 | 2921 | lruvec = mem_cgroup_zone_lruvec(zone, pc->mem_cgroup); |
9ce70c02 | 2922 | ClearPageLRU(page); |
fa9add64 | 2923 | del_page_from_lru_list(page, lruvec, page_lru(page)); |
9ce70c02 HD |
2924 | was_on_lru = true; |
2925 | } | |
2926 | } | |
2927 | ||
c0ff4b85 | 2928 | pc->mem_cgroup = memcg; |
261fb61a KH |
2929 | /* |
2930 | * We access a page_cgroup asynchronously without lock_page_cgroup(). | |
2931 | * Especially when a page_cgroup is taken from a page, pc->mem_cgroup | |
2932 | * is accessed after testing USED bit. To make pc->mem_cgroup visible | |
2933 | * before USED bit, we need memory barrier here. | |
2934 | * See mem_cgroup_add_lru_list(), etc. | |
2935 | */ | |
08e552c6 | 2936 | smp_wmb(); |
b2402857 | 2937 | SetPageCgroupUsed(pc); |
3be91277 | 2938 | |
9ce70c02 HD |
2939 | if (lrucare) { |
2940 | if (was_on_lru) { | |
fa9add64 | 2941 | lruvec = mem_cgroup_zone_lruvec(zone, pc->mem_cgroup); |
9ce70c02 HD |
2942 | VM_BUG_ON(PageLRU(page)); |
2943 | SetPageLRU(page); | |
fa9add64 | 2944 | add_page_to_lru_list(page, lruvec, page_lru(page)); |
9ce70c02 HD |
2945 | } |
2946 | spin_unlock_irq(&zone->lru_lock); | |
2947 | } | |
2948 | ||
41326c17 | 2949 | if (ctype == MEM_CGROUP_CHARGE_TYPE_ANON) |
b2402857 KH |
2950 | anon = true; |
2951 | else | |
2952 | anon = false; | |
2953 | ||
b070e65c | 2954 | mem_cgroup_charge_statistics(memcg, page, anon, nr_pages); |
52d4b9ac | 2955 | unlock_page_cgroup(pc); |
9ce70c02 | 2956 | |
430e4863 KH |
2957 | /* |
2958 | * "charge_statistics" updated event counter. Then, check it. | |
2959 | * Insert ancestor (and ancestor's ancestors), to softlimit RB-tree. | |
2960 | * if they exceeds softlimit. | |
2961 | */ | |
c0ff4b85 | 2962 | memcg_check_events(memcg, page); |
7a81b88c | 2963 | } |
66e1707b | 2964 | |
7cf27982 GC |
2965 | static DEFINE_MUTEX(set_limit_mutex); |
2966 | ||
7ae1e1d0 GC |
2967 | #ifdef CONFIG_MEMCG_KMEM |
2968 | static inline bool memcg_can_account_kmem(struct mem_cgroup *memcg) | |
2969 | { | |
2970 | return !mem_cgroup_disabled() && !mem_cgroup_is_root(memcg) && | |
2971 | (memcg->kmem_account_flags & KMEM_ACCOUNTED_MASK); | |
2972 | } | |
2973 | ||
1f458cbf GC |
2974 | /* |
2975 | * This is a bit cumbersome, but it is rarely used and avoids a backpointer | |
2976 | * in the memcg_cache_params struct. | |
2977 | */ | |
2978 | static struct kmem_cache *memcg_params_to_cache(struct memcg_cache_params *p) | |
2979 | { | |
2980 | struct kmem_cache *cachep; | |
2981 | ||
2982 | VM_BUG_ON(p->is_root_cache); | |
2983 | cachep = p->root_cache; | |
2984 | return cachep->memcg_params->memcg_caches[memcg_cache_id(p->memcg)]; | |
2985 | } | |
2986 | ||
749c5415 GC |
2987 | #ifdef CONFIG_SLABINFO |
2988 | static int mem_cgroup_slabinfo_read(struct cgroup *cont, struct cftype *cft, | |
2989 | struct seq_file *m) | |
2990 | { | |
2991 | struct mem_cgroup *memcg = mem_cgroup_from_cont(cont); | |
2992 | struct memcg_cache_params *params; | |
2993 | ||
2994 | if (!memcg_can_account_kmem(memcg)) | |
2995 | return -EIO; | |
2996 | ||
2997 | print_slabinfo_header(m); | |
2998 | ||
2999 | mutex_lock(&memcg->slab_caches_mutex); | |
3000 | list_for_each_entry(params, &memcg->memcg_slab_caches, list) | |
3001 | cache_show(memcg_params_to_cache(params), m); | |
3002 | mutex_unlock(&memcg->slab_caches_mutex); | |
3003 | ||
3004 | return 0; | |
3005 | } | |
3006 | #endif | |
3007 | ||
7ae1e1d0 GC |
3008 | static int memcg_charge_kmem(struct mem_cgroup *memcg, gfp_t gfp, u64 size) |
3009 | { | |
3010 | struct res_counter *fail_res; | |
3011 | struct mem_cgroup *_memcg; | |
3012 | int ret = 0; | |
3013 | bool may_oom; | |
3014 | ||
3015 | ret = res_counter_charge(&memcg->kmem, size, &fail_res); | |
3016 | if (ret) | |
3017 | return ret; | |
3018 | ||
3019 | /* | |
3020 | * Conditions under which we can wait for the oom_killer. Those are | |
3021 | * the same conditions tested by the core page allocator | |
3022 | */ | |
3023 | may_oom = (gfp & __GFP_FS) && !(gfp & __GFP_NORETRY); | |
3024 | ||
3025 | _memcg = memcg; | |
3026 | ret = __mem_cgroup_try_charge(NULL, gfp, size >> PAGE_SHIFT, | |
3027 | &_memcg, may_oom); | |
3028 | ||
3029 | if (ret == -EINTR) { | |
3030 | /* | |
3031 | * __mem_cgroup_try_charge() chosed to bypass to root due to | |
3032 | * OOM kill or fatal signal. Since our only options are to | |
3033 | * either fail the allocation or charge it to this cgroup, do | |
3034 | * it as a temporary condition. But we can't fail. From a | |
3035 | * kmem/slab perspective, the cache has already been selected, | |
3036 | * by mem_cgroup_kmem_get_cache(), so it is too late to change | |
3037 | * our minds. | |
3038 | * | |
3039 | * This condition will only trigger if the task entered | |
3040 | * memcg_charge_kmem in a sane state, but was OOM-killed during | |
3041 | * __mem_cgroup_try_charge() above. Tasks that were already | |
3042 | * dying when the allocation triggers should have been already | |
3043 | * directed to the root cgroup in memcontrol.h | |
3044 | */ | |
3045 | res_counter_charge_nofail(&memcg->res, size, &fail_res); | |
3046 | if (do_swap_account) | |
3047 | res_counter_charge_nofail(&memcg->memsw, size, | |
3048 | &fail_res); | |
3049 | ret = 0; | |
3050 | } else if (ret) | |
3051 | res_counter_uncharge(&memcg->kmem, size); | |
3052 | ||
3053 | return ret; | |
3054 | } | |
3055 | ||
3056 | static void memcg_uncharge_kmem(struct mem_cgroup *memcg, u64 size) | |
3057 | { | |
7ae1e1d0 GC |
3058 | res_counter_uncharge(&memcg->res, size); |
3059 | if (do_swap_account) | |
3060 | res_counter_uncharge(&memcg->memsw, size); | |
7de37682 GC |
3061 | |
3062 | /* Not down to 0 */ | |
3063 | if (res_counter_uncharge(&memcg->kmem, size)) | |
3064 | return; | |
3065 | ||
3066 | if (memcg_kmem_test_and_clear_dead(memcg)) | |
3067 | mem_cgroup_put(memcg); | |
7ae1e1d0 GC |
3068 | } |
3069 | ||
2633d7a0 GC |
3070 | void memcg_cache_list_add(struct mem_cgroup *memcg, struct kmem_cache *cachep) |
3071 | { | |
3072 | if (!memcg) | |
3073 | return; | |
3074 | ||
3075 | mutex_lock(&memcg->slab_caches_mutex); | |
3076 | list_add(&cachep->memcg_params->list, &memcg->memcg_slab_caches); | |
3077 | mutex_unlock(&memcg->slab_caches_mutex); | |
3078 | } | |
3079 | ||
3080 | /* | |
3081 | * helper for acessing a memcg's index. It will be used as an index in the | |
3082 | * child cache array in kmem_cache, and also to derive its name. This function | |
3083 | * will return -1 when this is not a kmem-limited memcg. | |
3084 | */ | |
3085 | int memcg_cache_id(struct mem_cgroup *memcg) | |
3086 | { | |
3087 | return memcg ? memcg->kmemcg_id : -1; | |
3088 | } | |
3089 | ||
55007d84 GC |
3090 | /* |
3091 | * This ends up being protected by the set_limit mutex, during normal | |
3092 | * operation, because that is its main call site. | |
3093 | * | |
3094 | * But when we create a new cache, we can call this as well if its parent | |
3095 | * is kmem-limited. That will have to hold set_limit_mutex as well. | |
3096 | */ | |
3097 | int memcg_update_cache_sizes(struct mem_cgroup *memcg) | |
3098 | { | |
3099 | int num, ret; | |
3100 | ||
3101 | num = ida_simple_get(&kmem_limited_groups, | |
3102 | 0, MEMCG_CACHES_MAX_SIZE, GFP_KERNEL); | |
3103 | if (num < 0) | |
3104 | return num; | |
3105 | /* | |
3106 | * After this point, kmem_accounted (that we test atomically in | |
3107 | * the beginning of this conditional), is no longer 0. This | |
3108 | * guarantees only one process will set the following boolean | |
3109 | * to true. We don't need test_and_set because we're protected | |
3110 | * by the set_limit_mutex anyway. | |
3111 | */ | |
3112 | memcg_kmem_set_activated(memcg); | |
3113 | ||
3114 | ret = memcg_update_all_caches(num+1); | |
3115 | if (ret) { | |
3116 | ida_simple_remove(&kmem_limited_groups, num); | |
3117 | memcg_kmem_clear_activated(memcg); | |
3118 | return ret; | |
3119 | } | |
3120 | ||
3121 | memcg->kmemcg_id = num; | |
3122 | INIT_LIST_HEAD(&memcg->memcg_slab_caches); | |
3123 | mutex_init(&memcg->slab_caches_mutex); | |
3124 | return 0; | |
3125 | } | |
3126 | ||
3127 | static size_t memcg_caches_array_size(int num_groups) | |
3128 | { | |
3129 | ssize_t size; | |
3130 | if (num_groups <= 0) | |
3131 | return 0; | |
3132 | ||
3133 | size = 2 * num_groups; | |
3134 | if (size < MEMCG_CACHES_MIN_SIZE) | |
3135 | size = MEMCG_CACHES_MIN_SIZE; | |
3136 | else if (size > MEMCG_CACHES_MAX_SIZE) | |
3137 | size = MEMCG_CACHES_MAX_SIZE; | |
3138 | ||
3139 | return size; | |
3140 | } | |
3141 | ||
3142 | /* | |
3143 | * We should update the current array size iff all caches updates succeed. This | |
3144 | * can only be done from the slab side. The slab mutex needs to be held when | |
3145 | * calling this. | |
3146 | */ | |
3147 | void memcg_update_array_size(int num) | |
3148 | { | |
3149 | if (num > memcg_limited_groups_array_size) | |
3150 | memcg_limited_groups_array_size = memcg_caches_array_size(num); | |
3151 | } | |
3152 | ||
15cf17d2 KK |
3153 | static void kmem_cache_destroy_work_func(struct work_struct *w); |
3154 | ||
55007d84 GC |
3155 | int memcg_update_cache_size(struct kmem_cache *s, int num_groups) |
3156 | { | |
3157 | struct memcg_cache_params *cur_params = s->memcg_params; | |
3158 | ||
3159 | VM_BUG_ON(s->memcg_params && !s->memcg_params->is_root_cache); | |
3160 | ||
3161 | if (num_groups > memcg_limited_groups_array_size) { | |
3162 | int i; | |
3163 | ssize_t size = memcg_caches_array_size(num_groups); | |
3164 | ||
3165 | size *= sizeof(void *); | |
3166 | size += sizeof(struct memcg_cache_params); | |
3167 | ||
3168 | s->memcg_params = kzalloc(size, GFP_KERNEL); | |
3169 | if (!s->memcg_params) { | |
3170 | s->memcg_params = cur_params; | |
3171 | return -ENOMEM; | |
3172 | } | |
3173 | ||
3174 | s->memcg_params->is_root_cache = true; | |
3175 | ||
3176 | /* | |
3177 | * There is the chance it will be bigger than | |
3178 | * memcg_limited_groups_array_size, if we failed an allocation | |
3179 | * in a cache, in which case all caches updated before it, will | |
3180 | * have a bigger array. | |
3181 | * | |
3182 | * But if that is the case, the data after | |
3183 | * memcg_limited_groups_array_size is certainly unused | |
3184 | */ | |
3185 | for (i = 0; i < memcg_limited_groups_array_size; i++) { | |
3186 | if (!cur_params->memcg_caches[i]) | |
3187 | continue; | |
3188 | s->memcg_params->memcg_caches[i] = | |
3189 | cur_params->memcg_caches[i]; | |
3190 | } | |
3191 | ||
3192 | /* | |
3193 | * Ideally, we would wait until all caches succeed, and only | |
3194 | * then free the old one. But this is not worth the extra | |
3195 | * pointer per-cache we'd have to have for this. | |
3196 | * | |
3197 | * It is not a big deal if some caches are left with a size | |
3198 | * bigger than the others. And all updates will reset this | |
3199 | * anyway. | |
3200 | */ | |
3201 | kfree(cur_params); | |
3202 | } | |
3203 | return 0; | |
3204 | } | |
3205 | ||
943a451a GC |
3206 | int memcg_register_cache(struct mem_cgroup *memcg, struct kmem_cache *s, |
3207 | struct kmem_cache *root_cache) | |
2633d7a0 GC |
3208 | { |
3209 | size_t size = sizeof(struct memcg_cache_params); | |
3210 | ||
3211 | if (!memcg_kmem_enabled()) | |
3212 | return 0; | |
3213 | ||
55007d84 GC |
3214 | if (!memcg) |
3215 | size += memcg_limited_groups_array_size * sizeof(void *); | |
3216 | ||
2633d7a0 GC |
3217 | s->memcg_params = kzalloc(size, GFP_KERNEL); |
3218 | if (!s->memcg_params) | |
3219 | return -ENOMEM; | |
3220 | ||
943a451a | 3221 | if (memcg) { |
2633d7a0 | 3222 | s->memcg_params->memcg = memcg; |
943a451a | 3223 | s->memcg_params->root_cache = root_cache; |
0dcf19b4 AV |
3224 | INIT_WORK(&s->memcg_params->destroy, |
3225 | kmem_cache_destroy_work_func); | |
4ba902b5 GC |
3226 | } else |
3227 | s->memcg_params->is_root_cache = true; | |
3228 | ||
2633d7a0 GC |
3229 | return 0; |
3230 | } | |
3231 | ||
3232 | void memcg_release_cache(struct kmem_cache *s) | |
3233 | { | |
d7f25f8a GC |
3234 | struct kmem_cache *root; |
3235 | struct mem_cgroup *memcg; | |
3236 | int id; | |
3237 | ||
3238 | /* | |
3239 | * This happens, for instance, when a root cache goes away before we | |
3240 | * add any memcg. | |
3241 | */ | |
3242 | if (!s->memcg_params) | |
3243 | return; | |
3244 | ||
3245 | if (s->memcg_params->is_root_cache) | |
3246 | goto out; | |
3247 | ||
3248 | memcg = s->memcg_params->memcg; | |
3249 | id = memcg_cache_id(memcg); | |
3250 | ||
3251 | root = s->memcg_params->root_cache; | |
3252 | root->memcg_params->memcg_caches[id] = NULL; | |
d7f25f8a GC |
3253 | |
3254 | mutex_lock(&memcg->slab_caches_mutex); | |
3255 | list_del(&s->memcg_params->list); | |
3256 | mutex_unlock(&memcg->slab_caches_mutex); | |
3257 | ||
fd0ccaf2 | 3258 | mem_cgroup_put(memcg); |
d7f25f8a | 3259 | out: |
2633d7a0 GC |
3260 | kfree(s->memcg_params); |
3261 | } | |
3262 | ||
0e9d92f2 GC |
3263 | /* |
3264 | * During the creation a new cache, we need to disable our accounting mechanism | |
3265 | * altogether. This is true even if we are not creating, but rather just | |
3266 | * enqueing new caches to be created. | |
3267 | * | |
3268 | * This is because that process will trigger allocations; some visible, like | |
3269 | * explicit kmallocs to auxiliary data structures, name strings and internal | |
3270 | * cache structures; some well concealed, like INIT_WORK() that can allocate | |
3271 | * objects during debug. | |
3272 | * | |
3273 | * If any allocation happens during memcg_kmem_get_cache, we will recurse back | |
3274 | * to it. This may not be a bounded recursion: since the first cache creation | |
3275 | * failed to complete (waiting on the allocation), we'll just try to create the | |
3276 | * cache again, failing at the same point. | |
3277 | * | |
3278 | * memcg_kmem_get_cache is prepared to abort after seeing a positive count of | |
3279 | * memcg_kmem_skip_account. So we enclose anything that might allocate memory | |
3280 | * inside the following two functions. | |
3281 | */ | |
3282 | static inline void memcg_stop_kmem_account(void) | |
3283 | { | |
3284 | VM_BUG_ON(!current->mm); | |
3285 | current->memcg_kmem_skip_account++; | |
3286 | } | |
3287 | ||
3288 | static inline void memcg_resume_kmem_account(void) | |
3289 | { | |
3290 | VM_BUG_ON(!current->mm); | |
3291 | current->memcg_kmem_skip_account--; | |
3292 | } | |
3293 | ||
1f458cbf GC |
3294 | static void kmem_cache_destroy_work_func(struct work_struct *w) |
3295 | { | |
3296 | struct kmem_cache *cachep; | |
3297 | struct memcg_cache_params *p; | |
3298 | ||
3299 | p = container_of(w, struct memcg_cache_params, destroy); | |
3300 | ||
3301 | cachep = memcg_params_to_cache(p); | |
3302 | ||
22933152 GC |
3303 | /* |
3304 | * If we get down to 0 after shrink, we could delete right away. | |
3305 | * However, memcg_release_pages() already puts us back in the workqueue | |
3306 | * in that case. If we proceed deleting, we'll get a dangling | |
3307 | * reference, and removing the object from the workqueue in that case | |
3308 | * is unnecessary complication. We are not a fast path. | |
3309 | * | |
3310 | * Note that this case is fundamentally different from racing with | |
3311 | * shrink_slab(): if memcg_cgroup_destroy_cache() is called in | |
3312 | * kmem_cache_shrink, not only we would be reinserting a dead cache | |
3313 | * into the queue, but doing so from inside the worker racing to | |
3314 | * destroy it. | |
3315 | * | |
3316 | * So if we aren't down to zero, we'll just schedule a worker and try | |
3317 | * again | |
3318 | */ | |
3319 | if (atomic_read(&cachep->memcg_params->nr_pages) != 0) { | |
3320 | kmem_cache_shrink(cachep); | |
3321 | if (atomic_read(&cachep->memcg_params->nr_pages) == 0) | |
3322 | return; | |
3323 | } else | |
1f458cbf GC |
3324 | kmem_cache_destroy(cachep); |
3325 | } | |
3326 | ||
3327 | void mem_cgroup_destroy_cache(struct kmem_cache *cachep) | |
3328 | { | |
3329 | if (!cachep->memcg_params->dead) | |
3330 | return; | |
3331 | ||
22933152 GC |
3332 | /* |
3333 | * There are many ways in which we can get here. | |
3334 | * | |
3335 | * We can get to a memory-pressure situation while the delayed work is | |
3336 | * still pending to run. The vmscan shrinkers can then release all | |
3337 | * cache memory and get us to destruction. If this is the case, we'll | |
3338 | * be executed twice, which is a bug (the second time will execute over | |
3339 | * bogus data). In this case, cancelling the work should be fine. | |
3340 | * | |
3341 | * But we can also get here from the worker itself, if | |
3342 | * kmem_cache_shrink is enough to shake all the remaining objects and | |
3343 | * get the page count to 0. In this case, we'll deadlock if we try to | |
3344 | * cancel the work (the worker runs with an internal lock held, which | |
3345 | * is the same lock we would hold for cancel_work_sync().) | |
3346 | * | |
3347 | * Since we can't possibly know who got us here, just refrain from | |
3348 | * running if there is already work pending | |
3349 | */ | |
3350 | if (work_pending(&cachep->memcg_params->destroy)) | |
3351 | return; | |
1f458cbf GC |
3352 | /* |
3353 | * We have to defer the actual destroying to a workqueue, because | |
3354 | * we might currently be in a context that cannot sleep. | |
3355 | */ | |
3356 | schedule_work(&cachep->memcg_params->destroy); | |
3357 | } | |
3358 | ||
d9c10ddd MH |
3359 | /* |
3360 | * This lock protects updaters, not readers. We want readers to be as fast as | |
3361 | * they can, and they will either see NULL or a valid cache value. Our model | |
3362 | * allow them to see NULL, in which case the root memcg will be selected. | |
3363 | * | |
3364 | * We need this lock because multiple allocations to the same cache from a non | |
3365 | * will span more than one worker. Only one of them can create the cache. | |
3366 | */ | |
3367 | static DEFINE_MUTEX(memcg_cache_mutex); | |
d7f25f8a | 3368 | |
d9c10ddd MH |
3369 | /* |
3370 | * Called with memcg_cache_mutex held | |
3371 | */ | |
d7f25f8a GC |
3372 | static struct kmem_cache *kmem_cache_dup(struct mem_cgroup *memcg, |
3373 | struct kmem_cache *s) | |
3374 | { | |
d7f25f8a | 3375 | struct kmem_cache *new; |
d9c10ddd | 3376 | static char *tmp_name = NULL; |
d7f25f8a | 3377 | |
d9c10ddd MH |
3378 | lockdep_assert_held(&memcg_cache_mutex); |
3379 | ||
3380 | /* | |
3381 | * kmem_cache_create_memcg duplicates the given name and | |
3382 | * cgroup_name for this name requires RCU context. | |
3383 | * This static temporary buffer is used to prevent from | |
3384 | * pointless shortliving allocation. | |
3385 | */ | |
3386 | if (!tmp_name) { | |
3387 | tmp_name = kmalloc(PATH_MAX, GFP_KERNEL); | |
3388 | if (!tmp_name) | |
3389 | return NULL; | |
3390 | } | |
3391 | ||
3392 | rcu_read_lock(); | |
3393 | snprintf(tmp_name, PATH_MAX, "%s(%d:%s)", s->name, | |
3394 | memcg_cache_id(memcg), cgroup_name(memcg->css.cgroup)); | |
3395 | rcu_read_unlock(); | |
d7f25f8a | 3396 | |
d9c10ddd | 3397 | new = kmem_cache_create_memcg(memcg, tmp_name, s->object_size, s->align, |
943a451a | 3398 | (s->flags & ~SLAB_PANIC), s->ctor, s); |
d7f25f8a | 3399 | |
d79923fa GC |
3400 | if (new) |
3401 | new->allocflags |= __GFP_KMEMCG; | |
3402 | ||
d7f25f8a GC |
3403 | return new; |
3404 | } | |
3405 | ||
d7f25f8a GC |
3406 | static struct kmem_cache *memcg_create_kmem_cache(struct mem_cgroup *memcg, |
3407 | struct kmem_cache *cachep) | |
3408 | { | |
3409 | struct kmem_cache *new_cachep; | |
3410 | int idx; | |
3411 | ||
3412 | BUG_ON(!memcg_can_account_kmem(memcg)); | |
3413 | ||
3414 | idx = memcg_cache_id(memcg); | |
3415 | ||
3416 | mutex_lock(&memcg_cache_mutex); | |
3417 | new_cachep = cachep->memcg_params->memcg_caches[idx]; | |
3418 | if (new_cachep) | |
3419 | goto out; | |
3420 | ||
3421 | new_cachep = kmem_cache_dup(memcg, cachep); | |
d7f25f8a GC |
3422 | if (new_cachep == NULL) { |
3423 | new_cachep = cachep; | |
3424 | goto out; | |
3425 | } | |
3426 | ||
3427 | mem_cgroup_get(memcg); | |
1f458cbf | 3428 | atomic_set(&new_cachep->memcg_params->nr_pages , 0); |
d7f25f8a GC |
3429 | |
3430 | cachep->memcg_params->memcg_caches[idx] = new_cachep; | |
3431 | /* | |
3432 | * the readers won't lock, make sure everybody sees the updated value, | |
3433 | * so they won't put stuff in the queue again for no reason | |
3434 | */ | |
3435 | wmb(); | |
3436 | out: | |
3437 | mutex_unlock(&memcg_cache_mutex); | |
3438 | return new_cachep; | |
3439 | } | |
3440 | ||
7cf27982 GC |
3441 | void kmem_cache_destroy_memcg_children(struct kmem_cache *s) |
3442 | { | |
3443 | struct kmem_cache *c; | |
3444 | int i; | |
3445 | ||
3446 | if (!s->memcg_params) | |
3447 | return; | |
3448 | if (!s->memcg_params->is_root_cache) | |
3449 | return; | |
3450 | ||
3451 | /* | |
3452 | * If the cache is being destroyed, we trust that there is no one else | |
3453 | * requesting objects from it. Even if there are, the sanity checks in | |
3454 | * kmem_cache_destroy should caught this ill-case. | |
3455 | * | |
3456 | * Still, we don't want anyone else freeing memcg_caches under our | |
3457 | * noses, which can happen if a new memcg comes to life. As usual, | |
3458 | * we'll take the set_limit_mutex to protect ourselves against this. | |
3459 | */ | |
3460 | mutex_lock(&set_limit_mutex); | |
3461 | for (i = 0; i < memcg_limited_groups_array_size; i++) { | |
3462 | c = s->memcg_params->memcg_caches[i]; | |
3463 | if (!c) | |
3464 | continue; | |
3465 | ||
3466 | /* | |
3467 | * We will now manually delete the caches, so to avoid races | |
3468 | * we need to cancel all pending destruction workers and | |
3469 | * proceed with destruction ourselves. | |
3470 | * | |
3471 | * kmem_cache_destroy() will call kmem_cache_shrink internally, | |
3472 | * and that could spawn the workers again: it is likely that | |
3473 | * the cache still have active pages until this very moment. | |
3474 | * This would lead us back to mem_cgroup_destroy_cache. | |
3475 | * | |
3476 | * But that will not execute at all if the "dead" flag is not | |
3477 | * set, so flip it down to guarantee we are in control. | |
3478 | */ | |
3479 | c->memcg_params->dead = false; | |
22933152 | 3480 | cancel_work_sync(&c->memcg_params->destroy); |
7cf27982 GC |
3481 | kmem_cache_destroy(c); |
3482 | } | |
3483 | mutex_unlock(&set_limit_mutex); | |
3484 | } | |
3485 | ||
d7f25f8a GC |
3486 | struct create_work { |
3487 | struct mem_cgroup *memcg; | |
3488 | struct kmem_cache *cachep; | |
3489 | struct work_struct work; | |
3490 | }; | |
3491 | ||
1f458cbf GC |
3492 | static void mem_cgroup_destroy_all_caches(struct mem_cgroup *memcg) |
3493 | { | |
3494 | struct kmem_cache *cachep; | |
3495 | struct memcg_cache_params *params; | |
3496 | ||
3497 | if (!memcg_kmem_is_active(memcg)) | |
3498 | return; | |
3499 | ||
3500 | mutex_lock(&memcg->slab_caches_mutex); | |
3501 | list_for_each_entry(params, &memcg->memcg_slab_caches, list) { | |
3502 | cachep = memcg_params_to_cache(params); | |
3503 | cachep->memcg_params->dead = true; | |
1f458cbf GC |
3504 | schedule_work(&cachep->memcg_params->destroy); |
3505 | } | |
3506 | mutex_unlock(&memcg->slab_caches_mutex); | |
3507 | } | |
3508 | ||
d7f25f8a GC |
3509 | static void memcg_create_cache_work_func(struct work_struct *w) |
3510 | { | |
3511 | struct create_work *cw; | |
3512 | ||
3513 | cw = container_of(w, struct create_work, work); | |
3514 | memcg_create_kmem_cache(cw->memcg, cw->cachep); | |
3515 | /* Drop the reference gotten when we enqueued. */ | |
3516 | css_put(&cw->memcg->css); | |
3517 | kfree(cw); | |
3518 | } | |
3519 | ||
3520 | /* | |
3521 | * Enqueue the creation of a per-memcg kmem_cache. | |
d7f25f8a | 3522 | */ |
0e9d92f2 GC |
3523 | static void __memcg_create_cache_enqueue(struct mem_cgroup *memcg, |
3524 | struct kmem_cache *cachep) | |
d7f25f8a GC |
3525 | { |
3526 | struct create_work *cw; | |
3527 | ||
3528 | cw = kmalloc(sizeof(struct create_work), GFP_NOWAIT); | |
ca0dde97 LZ |
3529 | if (cw == NULL) { |
3530 | css_put(&memcg->css); | |
d7f25f8a GC |
3531 | return; |
3532 | } | |
3533 | ||
3534 | cw->memcg = memcg; | |
3535 | cw->cachep = cachep; | |
3536 | ||
3537 | INIT_WORK(&cw->work, memcg_create_cache_work_func); | |
3538 | schedule_work(&cw->work); | |
3539 | } | |
3540 | ||
0e9d92f2 GC |
3541 | static void memcg_create_cache_enqueue(struct mem_cgroup *memcg, |
3542 | struct kmem_cache *cachep) | |
3543 | { | |
3544 | /* | |
3545 | * We need to stop accounting when we kmalloc, because if the | |
3546 | * corresponding kmalloc cache is not yet created, the first allocation | |
3547 | * in __memcg_create_cache_enqueue will recurse. | |
3548 | * | |
3549 | * However, it is better to enclose the whole function. Depending on | |
3550 | * the debugging options enabled, INIT_WORK(), for instance, can | |
3551 | * trigger an allocation. This too, will make us recurse. Because at | |
3552 | * this point we can't allow ourselves back into memcg_kmem_get_cache, | |
3553 | * the safest choice is to do it like this, wrapping the whole function. | |
3554 | */ | |
3555 | memcg_stop_kmem_account(); | |
3556 | __memcg_create_cache_enqueue(memcg, cachep); | |
3557 | memcg_resume_kmem_account(); | |
3558 | } | |
d7f25f8a GC |
3559 | /* |
3560 | * Return the kmem_cache we're supposed to use for a slab allocation. | |
3561 | * We try to use the current memcg's version of the cache. | |
3562 | * | |
3563 | * If the cache does not exist yet, if we are the first user of it, | |
3564 | * we either create it immediately, if possible, or create it asynchronously | |
3565 | * in a workqueue. | |
3566 | * In the latter case, we will let the current allocation go through with | |
3567 | * the original cache. | |
3568 | * | |
3569 | * Can't be called in interrupt context or from kernel threads. | |
3570 | * This function needs to be called with rcu_read_lock() held. | |
3571 | */ | |
3572 | struct kmem_cache *__memcg_kmem_get_cache(struct kmem_cache *cachep, | |
3573 | gfp_t gfp) | |
3574 | { | |
3575 | struct mem_cgroup *memcg; | |
3576 | int idx; | |
3577 | ||
3578 | VM_BUG_ON(!cachep->memcg_params); | |
3579 | VM_BUG_ON(!cachep->memcg_params->is_root_cache); | |
3580 | ||
0e9d92f2 GC |
3581 | if (!current->mm || current->memcg_kmem_skip_account) |
3582 | return cachep; | |
3583 | ||
d7f25f8a GC |
3584 | rcu_read_lock(); |
3585 | memcg = mem_cgroup_from_task(rcu_dereference(current->mm->owner)); | |
d7f25f8a GC |
3586 | |
3587 | if (!memcg_can_account_kmem(memcg)) | |
ca0dde97 | 3588 | goto out; |
d7f25f8a GC |
3589 | |
3590 | idx = memcg_cache_id(memcg); | |
3591 | ||
3592 | /* | |
3593 | * barrier to mare sure we're always seeing the up to date value. The | |
3594 | * code updating memcg_caches will issue a write barrier to match this. | |
3595 | */ | |
3596 | read_barrier_depends(); | |
ca0dde97 LZ |
3597 | if (likely(cachep->memcg_params->memcg_caches[idx])) { |
3598 | cachep = cachep->memcg_params->memcg_caches[idx]; | |
3599 | goto out; | |
d7f25f8a GC |
3600 | } |
3601 | ||
ca0dde97 LZ |
3602 | /* The corresponding put will be done in the workqueue. */ |
3603 | if (!css_tryget(&memcg->css)) | |
3604 | goto out; | |
3605 | rcu_read_unlock(); | |
3606 | ||
3607 | /* | |
3608 | * If we are in a safe context (can wait, and not in interrupt | |
3609 | * context), we could be be predictable and return right away. | |
3610 | * This would guarantee that the allocation being performed | |
3611 | * already belongs in the new cache. | |
3612 | * | |
3613 | * However, there are some clashes that can arrive from locking. | |
3614 | * For instance, because we acquire the slab_mutex while doing | |
3615 | * kmem_cache_dup, this means no further allocation could happen | |
3616 | * with the slab_mutex held. | |
3617 | * | |
3618 | * Also, because cache creation issue get_online_cpus(), this | |
3619 | * creates a lock chain: memcg_slab_mutex -> cpu_hotplug_mutex, | |
3620 | * that ends up reversed during cpu hotplug. (cpuset allocates | |
3621 | * a bunch of GFP_KERNEL memory during cpuup). Due to all that, | |
3622 | * better to defer everything. | |
3623 | */ | |
3624 | memcg_create_cache_enqueue(memcg, cachep); | |
3625 | return cachep; | |
3626 | out: | |
3627 | rcu_read_unlock(); | |
3628 | return cachep; | |
d7f25f8a GC |
3629 | } |
3630 | EXPORT_SYMBOL(__memcg_kmem_get_cache); | |
3631 | ||
7ae1e1d0 GC |
3632 | /* |
3633 | * We need to verify if the allocation against current->mm->owner's memcg is | |
3634 | * possible for the given order. But the page is not allocated yet, so we'll | |
3635 | * need a further commit step to do the final arrangements. | |
3636 | * | |
3637 | * It is possible for the task to switch cgroups in this mean time, so at | |
3638 | * commit time, we can't rely on task conversion any longer. We'll then use | |
3639 | * the handle argument to return to the caller which cgroup we should commit | |
3640 | * against. We could also return the memcg directly and avoid the pointer | |
3641 | * passing, but a boolean return value gives better semantics considering | |
3642 | * the compiled-out case as well. | |
3643 | * | |
3644 | * Returning true means the allocation is possible. | |
3645 | */ | |
3646 | bool | |
3647 | __memcg_kmem_newpage_charge(gfp_t gfp, struct mem_cgroup **_memcg, int order) | |
3648 | { | |
3649 | struct mem_cgroup *memcg; | |
3650 | int ret; | |
3651 | ||
3652 | *_memcg = NULL; | |
3653 | memcg = try_get_mem_cgroup_from_mm(current->mm); | |
3654 | ||
3655 | /* | |
3656 | * very rare case described in mem_cgroup_from_task. Unfortunately there | |
3657 | * isn't much we can do without complicating this too much, and it would | |
3658 | * be gfp-dependent anyway. Just let it go | |
3659 | */ | |
3660 | if (unlikely(!memcg)) | |
3661 | return true; | |
3662 | ||
3663 | if (!memcg_can_account_kmem(memcg)) { | |
3664 | css_put(&memcg->css); | |
3665 | return true; | |
3666 | } | |
3667 | ||
7ae1e1d0 GC |
3668 | ret = memcg_charge_kmem(memcg, gfp, PAGE_SIZE << order); |
3669 | if (!ret) | |
3670 | *_memcg = memcg; | |
7ae1e1d0 GC |
3671 | |
3672 | css_put(&memcg->css); | |
3673 | return (ret == 0); | |
3674 | } | |
3675 | ||
3676 | void __memcg_kmem_commit_charge(struct page *page, struct mem_cgroup *memcg, | |
3677 | int order) | |
3678 | { | |
3679 | struct page_cgroup *pc; | |
3680 | ||
3681 | VM_BUG_ON(mem_cgroup_is_root(memcg)); | |
3682 | ||
3683 | /* The page allocation failed. Revert */ | |
3684 | if (!page) { | |
3685 | memcg_uncharge_kmem(memcg, PAGE_SIZE << order); | |
7ae1e1d0 GC |
3686 | return; |
3687 | } | |
3688 | ||
3689 | pc = lookup_page_cgroup(page); | |
3690 | lock_page_cgroup(pc); | |
3691 | pc->mem_cgroup = memcg; | |
3692 | SetPageCgroupUsed(pc); | |
3693 | unlock_page_cgroup(pc); | |
3694 | } | |
3695 | ||
3696 | void __memcg_kmem_uncharge_pages(struct page *page, int order) | |
3697 | { | |
3698 | struct mem_cgroup *memcg = NULL; | |
3699 | struct page_cgroup *pc; | |
3700 | ||
3701 | ||
3702 | pc = lookup_page_cgroup(page); | |
3703 | /* | |
3704 | * Fast unlocked return. Theoretically might have changed, have to | |
3705 | * check again after locking. | |
3706 | */ | |
3707 | if (!PageCgroupUsed(pc)) | |
3708 | return; | |
3709 | ||
3710 | lock_page_cgroup(pc); | |
3711 | if (PageCgroupUsed(pc)) { | |
3712 | memcg = pc->mem_cgroup; | |
3713 | ClearPageCgroupUsed(pc); | |
3714 | } | |
3715 | unlock_page_cgroup(pc); | |
3716 | ||
3717 | /* | |
3718 | * We trust that only if there is a memcg associated with the page, it | |
3719 | * is a valid allocation | |
3720 | */ | |
3721 | if (!memcg) | |
3722 | return; | |
3723 | ||
3724 | VM_BUG_ON(mem_cgroup_is_root(memcg)); | |
3725 | memcg_uncharge_kmem(memcg, PAGE_SIZE << order); | |
7ae1e1d0 | 3726 | } |
1f458cbf GC |
3727 | #else |
3728 | static inline void mem_cgroup_destroy_all_caches(struct mem_cgroup *memcg) | |
3729 | { | |
3730 | } | |
7ae1e1d0 GC |
3731 | #endif /* CONFIG_MEMCG_KMEM */ |
3732 | ||
ca3e0214 KH |
3733 | #ifdef CONFIG_TRANSPARENT_HUGEPAGE |
3734 | ||
a0db00fc | 3735 | #define PCGF_NOCOPY_AT_SPLIT (1 << PCG_LOCK | 1 << PCG_MIGRATION) |
ca3e0214 KH |
3736 | /* |
3737 | * Because tail pages are not marked as "used", set it. We're under | |
e94c8a9c KH |
3738 | * zone->lru_lock, 'splitting on pmd' and compound_lock. |
3739 | * charge/uncharge will be never happen and move_account() is done under | |
3740 | * compound_lock(), so we don't have to take care of races. | |
ca3e0214 | 3741 | */ |
e94c8a9c | 3742 | void mem_cgroup_split_huge_fixup(struct page *head) |
ca3e0214 KH |
3743 | { |
3744 | struct page_cgroup *head_pc = lookup_page_cgroup(head); | |
e94c8a9c | 3745 | struct page_cgroup *pc; |
b070e65c | 3746 | struct mem_cgroup *memcg; |
e94c8a9c | 3747 | int i; |
ca3e0214 | 3748 | |
3d37c4a9 KH |
3749 | if (mem_cgroup_disabled()) |
3750 | return; | |
b070e65c DR |
3751 | |
3752 | memcg = head_pc->mem_cgroup; | |
e94c8a9c KH |
3753 | for (i = 1; i < HPAGE_PMD_NR; i++) { |
3754 | pc = head_pc + i; | |
b070e65c | 3755 | pc->mem_cgroup = memcg; |
e94c8a9c | 3756 | smp_wmb();/* see __commit_charge() */ |
e94c8a9c KH |
3757 | pc->flags = head_pc->flags & ~PCGF_NOCOPY_AT_SPLIT; |
3758 | } | |
b070e65c DR |
3759 | __this_cpu_sub(memcg->stat->count[MEM_CGROUP_STAT_RSS_HUGE], |
3760 | HPAGE_PMD_NR); | |
ca3e0214 | 3761 | } |
12d27107 | 3762 | #endif /* CONFIG_TRANSPARENT_HUGEPAGE */ |
ca3e0214 | 3763 | |
f817ed48 | 3764 | /** |
de3638d9 | 3765 | * mem_cgroup_move_account - move account of the page |
5564e88b | 3766 | * @page: the page |
7ec99d62 | 3767 | * @nr_pages: number of regular pages (>1 for huge pages) |
f817ed48 KH |
3768 | * @pc: page_cgroup of the page. |
3769 | * @from: mem_cgroup which the page is moved from. | |
3770 | * @to: mem_cgroup which the page is moved to. @from != @to. | |
3771 | * | |
3772 | * The caller must confirm following. | |
08e552c6 | 3773 | * - page is not on LRU (isolate_page() is useful.) |
7ec99d62 | 3774 | * - compound_lock is held when nr_pages > 1 |
f817ed48 | 3775 | * |
2f3479b1 KH |
3776 | * This function doesn't do "charge" to new cgroup and doesn't do "uncharge" |
3777 | * from old cgroup. | |
f817ed48 | 3778 | */ |
7ec99d62 JW |
3779 | static int mem_cgroup_move_account(struct page *page, |
3780 | unsigned int nr_pages, | |
3781 | struct page_cgroup *pc, | |
3782 | struct mem_cgroup *from, | |
2f3479b1 | 3783 | struct mem_cgroup *to) |
f817ed48 | 3784 | { |
de3638d9 JW |
3785 | unsigned long flags; |
3786 | int ret; | |
b2402857 | 3787 | bool anon = PageAnon(page); |
987eba66 | 3788 | |
f817ed48 | 3789 | VM_BUG_ON(from == to); |
5564e88b | 3790 | VM_BUG_ON(PageLRU(page)); |
de3638d9 JW |
3791 | /* |
3792 | * The page is isolated from LRU. So, collapse function | |
3793 | * will not handle this page. But page splitting can happen. | |
3794 | * Do this check under compound_page_lock(). The caller should | |
3795 | * hold it. | |
3796 | */ | |
3797 | ret = -EBUSY; | |
7ec99d62 | 3798 | if (nr_pages > 1 && !PageTransHuge(page)) |
de3638d9 JW |
3799 | goto out; |
3800 | ||
3801 | lock_page_cgroup(pc); | |
3802 | ||
3803 | ret = -EINVAL; | |
3804 | if (!PageCgroupUsed(pc) || pc->mem_cgroup != from) | |
3805 | goto unlock; | |
3806 | ||
312734c0 | 3807 | move_lock_mem_cgroup(from, &flags); |
f817ed48 | 3808 | |
2ff76f11 | 3809 | if (!anon && page_mapped(page)) { |
c62b1a3b KH |
3810 | /* Update mapped_file data for mem_cgroup */ |
3811 | preempt_disable(); | |
3812 | __this_cpu_dec(from->stat->count[MEM_CGROUP_STAT_FILE_MAPPED]); | |
3813 | __this_cpu_inc(to->stat->count[MEM_CGROUP_STAT_FILE_MAPPED]); | |
3814 | preempt_enable(); | |
d69b042f | 3815 | } |
b070e65c | 3816 | mem_cgroup_charge_statistics(from, page, anon, -nr_pages); |
d69b042f | 3817 | |
854ffa8d | 3818 | /* caller should have done css_get */ |
08e552c6 | 3819 | pc->mem_cgroup = to; |
b070e65c | 3820 | mem_cgroup_charge_statistics(to, page, anon, nr_pages); |
312734c0 | 3821 | move_unlock_mem_cgroup(from, &flags); |
de3638d9 JW |
3822 | ret = 0; |
3823 | unlock: | |
57f9fd7d | 3824 | unlock_page_cgroup(pc); |
d2265e6f KH |
3825 | /* |
3826 | * check events | |
3827 | */ | |
5564e88b JW |
3828 | memcg_check_events(to, page); |
3829 | memcg_check_events(from, page); | |
de3638d9 | 3830 | out: |
f817ed48 KH |
3831 | return ret; |
3832 | } | |
3833 | ||
2ef37d3f MH |
3834 | /** |
3835 | * mem_cgroup_move_parent - moves page to the parent group | |
3836 | * @page: the page to move | |
3837 | * @pc: page_cgroup of the page | |
3838 | * @child: page's cgroup | |
3839 | * | |
3840 | * move charges to its parent or the root cgroup if the group has no | |
3841 | * parent (aka use_hierarchy==0). | |
3842 | * Although this might fail (get_page_unless_zero, isolate_lru_page or | |
3843 | * mem_cgroup_move_account fails) the failure is always temporary and | |
3844 | * it signals a race with a page removal/uncharge or migration. In the | |
3845 | * first case the page is on the way out and it will vanish from the LRU | |
3846 | * on the next attempt and the call should be retried later. | |
3847 | * Isolation from the LRU fails only if page has been isolated from | |
3848 | * the LRU since we looked at it and that usually means either global | |
3849 | * reclaim or migration going on. The page will either get back to the | |
3850 | * LRU or vanish. | |
3851 | * Finaly mem_cgroup_move_account fails only if the page got uncharged | |
3852 | * (!PageCgroupUsed) or moved to a different group. The page will | |
3853 | * disappear in the next attempt. | |
f817ed48 | 3854 | */ |
5564e88b JW |
3855 | static int mem_cgroup_move_parent(struct page *page, |
3856 | struct page_cgroup *pc, | |
6068bf01 | 3857 | struct mem_cgroup *child) |
f817ed48 | 3858 | { |
f817ed48 | 3859 | struct mem_cgroup *parent; |
7ec99d62 | 3860 | unsigned int nr_pages; |
4be4489f | 3861 | unsigned long uninitialized_var(flags); |
f817ed48 KH |
3862 | int ret; |
3863 | ||
d8423011 | 3864 | VM_BUG_ON(mem_cgroup_is_root(child)); |
f817ed48 | 3865 | |
57f9fd7d DN |
3866 | ret = -EBUSY; |
3867 | if (!get_page_unless_zero(page)) | |
3868 | goto out; | |
3869 | if (isolate_lru_page(page)) | |
3870 | goto put; | |
52dbb905 | 3871 | |
7ec99d62 | 3872 | nr_pages = hpage_nr_pages(page); |
08e552c6 | 3873 | |
cc926f78 KH |
3874 | parent = parent_mem_cgroup(child); |
3875 | /* | |
3876 | * If no parent, move charges to root cgroup. | |
3877 | */ | |
3878 | if (!parent) | |
3879 | parent = root_mem_cgroup; | |
f817ed48 | 3880 | |
2ef37d3f MH |
3881 | if (nr_pages > 1) { |
3882 | VM_BUG_ON(!PageTransHuge(page)); | |
987eba66 | 3883 | flags = compound_lock_irqsave(page); |
2ef37d3f | 3884 | } |
987eba66 | 3885 | |
cc926f78 | 3886 | ret = mem_cgroup_move_account(page, nr_pages, |
2f3479b1 | 3887 | pc, child, parent); |
cc926f78 KH |
3888 | if (!ret) |
3889 | __mem_cgroup_cancel_local_charge(child, nr_pages); | |
8dba474f | 3890 | |
7ec99d62 | 3891 | if (nr_pages > 1) |
987eba66 | 3892 | compound_unlock_irqrestore(page, flags); |
08e552c6 | 3893 | putback_lru_page(page); |
57f9fd7d | 3894 | put: |
40d58138 | 3895 | put_page(page); |
57f9fd7d | 3896 | out: |
f817ed48 KH |
3897 | return ret; |
3898 | } | |
3899 | ||
7a81b88c KH |
3900 | /* |
3901 | * Charge the memory controller for page usage. | |
3902 | * Return | |
3903 | * 0 if the charge was successful | |
3904 | * < 0 if the cgroup is over its limit | |
3905 | */ | |
3906 | static int mem_cgroup_charge_common(struct page *page, struct mm_struct *mm, | |
73045c47 | 3907 | gfp_t gfp_mask, enum charge_type ctype) |
7a81b88c | 3908 | { |
c0ff4b85 | 3909 | struct mem_cgroup *memcg = NULL; |
7ec99d62 | 3910 | unsigned int nr_pages = 1; |
8493ae43 | 3911 | bool oom = true; |
7a81b88c | 3912 | int ret; |
ec168510 | 3913 | |
37c2ac78 | 3914 | if (PageTransHuge(page)) { |
7ec99d62 | 3915 | nr_pages <<= compound_order(page); |
37c2ac78 | 3916 | VM_BUG_ON(!PageTransHuge(page)); |
8493ae43 JW |
3917 | /* |
3918 | * Never OOM-kill a process for a huge page. The | |
3919 | * fault handler will fall back to regular pages. | |
3920 | */ | |
3921 | oom = false; | |
37c2ac78 | 3922 | } |
7a81b88c | 3923 | |
c0ff4b85 | 3924 | ret = __mem_cgroup_try_charge(mm, gfp_mask, nr_pages, &memcg, oom); |
38c5d72f | 3925 | if (ret == -ENOMEM) |
7a81b88c | 3926 | return ret; |
ce587e65 | 3927 | __mem_cgroup_commit_charge(memcg, page, nr_pages, ctype, false); |
8a9f3ccd | 3928 | return 0; |
8a9f3ccd BS |
3929 | } |
3930 | ||
7a81b88c KH |
3931 | int mem_cgroup_newpage_charge(struct page *page, |
3932 | struct mm_struct *mm, gfp_t gfp_mask) | |
217bc319 | 3933 | { |
f8d66542 | 3934 | if (mem_cgroup_disabled()) |
cede86ac | 3935 | return 0; |
7a0524cf JW |
3936 | VM_BUG_ON(page_mapped(page)); |
3937 | VM_BUG_ON(page->mapping && !PageAnon(page)); | |
3938 | VM_BUG_ON(!mm); | |
217bc319 | 3939 | return mem_cgroup_charge_common(page, mm, gfp_mask, |
41326c17 | 3940 | MEM_CGROUP_CHARGE_TYPE_ANON); |
217bc319 KH |
3941 | } |
3942 | ||
54595fe2 KH |
3943 | /* |
3944 | * While swap-in, try_charge -> commit or cancel, the page is locked. | |
3945 | * And when try_charge() successfully returns, one refcnt to memcg without | |
21ae2956 | 3946 | * struct page_cgroup is acquired. This refcnt will be consumed by |
54595fe2 KH |
3947 | * "commit()" or removed by "cancel()" |
3948 | */ | |
0435a2fd JW |
3949 | static int __mem_cgroup_try_charge_swapin(struct mm_struct *mm, |
3950 | struct page *page, | |
3951 | gfp_t mask, | |
3952 | struct mem_cgroup **memcgp) | |
8c7c6e34 | 3953 | { |
c0ff4b85 | 3954 | struct mem_cgroup *memcg; |
90deb788 | 3955 | struct page_cgroup *pc; |
54595fe2 | 3956 | int ret; |
8c7c6e34 | 3957 | |
90deb788 JW |
3958 | pc = lookup_page_cgroup(page); |
3959 | /* | |
3960 | * Every swap fault against a single page tries to charge the | |
3961 | * page, bail as early as possible. shmem_unuse() encounters | |
3962 | * already charged pages, too. The USED bit is protected by | |
3963 | * the page lock, which serializes swap cache removal, which | |
3964 | * in turn serializes uncharging. | |
3965 | */ | |
3966 | if (PageCgroupUsed(pc)) | |
3967 | return 0; | |
8c7c6e34 KH |
3968 | if (!do_swap_account) |
3969 | goto charge_cur_mm; | |
c0ff4b85 R |
3970 | memcg = try_get_mem_cgroup_from_page(page); |
3971 | if (!memcg) | |
54595fe2 | 3972 | goto charge_cur_mm; |
72835c86 JW |
3973 | *memcgp = memcg; |
3974 | ret = __mem_cgroup_try_charge(NULL, mask, 1, memcgp, true); | |
c0ff4b85 | 3975 | css_put(&memcg->css); |
38c5d72f KH |
3976 | if (ret == -EINTR) |
3977 | ret = 0; | |
54595fe2 | 3978 | return ret; |
8c7c6e34 | 3979 | charge_cur_mm: |
38c5d72f KH |
3980 | ret = __mem_cgroup_try_charge(mm, mask, 1, memcgp, true); |
3981 | if (ret == -EINTR) | |
3982 | ret = 0; | |
3983 | return ret; | |
8c7c6e34 KH |
3984 | } |
3985 | ||
0435a2fd JW |
3986 | int mem_cgroup_try_charge_swapin(struct mm_struct *mm, struct page *page, |
3987 | gfp_t gfp_mask, struct mem_cgroup **memcgp) | |
3988 | { | |
3989 | *memcgp = NULL; | |
3990 | if (mem_cgroup_disabled()) | |
3991 | return 0; | |
bdf4f4d2 JW |
3992 | /* |
3993 | * A racing thread's fault, or swapoff, may have already | |
3994 | * updated the pte, and even removed page from swap cache: in | |
3995 | * those cases unuse_pte()'s pte_same() test will fail; but | |
3996 | * there's also a KSM case which does need to charge the page. | |
3997 | */ | |
3998 | if (!PageSwapCache(page)) { | |
3999 | int ret; | |
4000 | ||
4001 | ret = __mem_cgroup_try_charge(mm, gfp_mask, 1, memcgp, true); | |
4002 | if (ret == -EINTR) | |
4003 | ret = 0; | |
4004 | return ret; | |
4005 | } | |
0435a2fd JW |
4006 | return __mem_cgroup_try_charge_swapin(mm, page, gfp_mask, memcgp); |
4007 | } | |
4008 | ||
827a03d2 JW |
4009 | void mem_cgroup_cancel_charge_swapin(struct mem_cgroup *memcg) |
4010 | { | |
4011 | if (mem_cgroup_disabled()) | |
4012 | return; | |
4013 | if (!memcg) | |
4014 | return; | |
4015 | __mem_cgroup_cancel_charge(memcg, 1); | |
4016 | } | |
4017 | ||
83aae4c7 | 4018 | static void |
72835c86 | 4019 | __mem_cgroup_commit_charge_swapin(struct page *page, struct mem_cgroup *memcg, |
83aae4c7 | 4020 | enum charge_type ctype) |
7a81b88c | 4021 | { |
f8d66542 | 4022 | if (mem_cgroup_disabled()) |
7a81b88c | 4023 | return; |
72835c86 | 4024 | if (!memcg) |
7a81b88c | 4025 | return; |
5a6475a4 | 4026 | |
ce587e65 | 4027 | __mem_cgroup_commit_charge(memcg, page, 1, ctype, true); |
8c7c6e34 KH |
4028 | /* |
4029 | * Now swap is on-memory. This means this page may be | |
4030 | * counted both as mem and swap....double count. | |
03f3c433 KH |
4031 | * Fix it by uncharging from memsw. Basically, this SwapCache is stable |
4032 | * under lock_page(). But in do_swap_page()::memory.c, reuse_swap_page() | |
4033 | * may call delete_from_swap_cache() before reach here. | |
8c7c6e34 | 4034 | */ |
03f3c433 | 4035 | if (do_swap_account && PageSwapCache(page)) { |
8c7c6e34 | 4036 | swp_entry_t ent = {.val = page_private(page)}; |
86493009 | 4037 | mem_cgroup_uncharge_swap(ent); |
8c7c6e34 | 4038 | } |
7a81b88c KH |
4039 | } |
4040 | ||
72835c86 JW |
4041 | void mem_cgroup_commit_charge_swapin(struct page *page, |
4042 | struct mem_cgroup *memcg) | |
83aae4c7 | 4043 | { |
72835c86 | 4044 | __mem_cgroup_commit_charge_swapin(page, memcg, |
41326c17 | 4045 | MEM_CGROUP_CHARGE_TYPE_ANON); |
83aae4c7 DN |
4046 | } |
4047 | ||
827a03d2 JW |
4048 | int mem_cgroup_cache_charge(struct page *page, struct mm_struct *mm, |
4049 | gfp_t gfp_mask) | |
7a81b88c | 4050 | { |
827a03d2 JW |
4051 | struct mem_cgroup *memcg = NULL; |
4052 | enum charge_type type = MEM_CGROUP_CHARGE_TYPE_CACHE; | |
4053 | int ret; | |
4054 | ||
f8d66542 | 4055 | if (mem_cgroup_disabled()) |
827a03d2 JW |
4056 | return 0; |
4057 | if (PageCompound(page)) | |
4058 | return 0; | |
4059 | ||
827a03d2 JW |
4060 | if (!PageSwapCache(page)) |
4061 | ret = mem_cgroup_charge_common(page, mm, gfp_mask, type); | |
4062 | else { /* page is swapcache/shmem */ | |
0435a2fd JW |
4063 | ret = __mem_cgroup_try_charge_swapin(mm, page, |
4064 | gfp_mask, &memcg); | |
827a03d2 JW |
4065 | if (!ret) |
4066 | __mem_cgroup_commit_charge_swapin(page, memcg, type); | |
4067 | } | |
4068 | return ret; | |
7a81b88c KH |
4069 | } |
4070 | ||
c0ff4b85 | 4071 | static void mem_cgroup_do_uncharge(struct mem_cgroup *memcg, |
7ec99d62 JW |
4072 | unsigned int nr_pages, |
4073 | const enum charge_type ctype) | |
569b846d KH |
4074 | { |
4075 | struct memcg_batch_info *batch = NULL; | |
4076 | bool uncharge_memsw = true; | |
7ec99d62 | 4077 | |
569b846d KH |
4078 | /* If swapout, usage of swap doesn't decrease */ |
4079 | if (!do_swap_account || ctype == MEM_CGROUP_CHARGE_TYPE_SWAPOUT) | |
4080 | uncharge_memsw = false; | |
569b846d KH |
4081 | |
4082 | batch = ¤t->memcg_batch; | |
4083 | /* | |
4084 | * In usual, we do css_get() when we remember memcg pointer. | |
4085 | * But in this case, we keep res->usage until end of a series of | |
4086 | * uncharges. Then, it's ok to ignore memcg's refcnt. | |
4087 | */ | |
4088 | if (!batch->memcg) | |
c0ff4b85 | 4089 | batch->memcg = memcg; |
3c11ecf4 KH |
4090 | /* |
4091 | * do_batch > 0 when unmapping pages or inode invalidate/truncate. | |
25985edc | 4092 | * In those cases, all pages freed continuously can be expected to be in |
3c11ecf4 KH |
4093 | * the same cgroup and we have chance to coalesce uncharges. |
4094 | * But we do uncharge one by one if this is killed by OOM(TIF_MEMDIE) | |
4095 | * because we want to do uncharge as soon as possible. | |
4096 | */ | |
4097 | ||
4098 | if (!batch->do_batch || test_thread_flag(TIF_MEMDIE)) | |
4099 | goto direct_uncharge; | |
4100 | ||
7ec99d62 | 4101 | if (nr_pages > 1) |
ec168510 AA |
4102 | goto direct_uncharge; |
4103 | ||
569b846d KH |
4104 | /* |
4105 | * In typical case, batch->memcg == mem. This means we can | |
4106 | * merge a series of uncharges to an uncharge of res_counter. | |
4107 | * If not, we uncharge res_counter ony by one. | |
4108 | */ | |
c0ff4b85 | 4109 | if (batch->memcg != memcg) |
569b846d KH |
4110 | goto direct_uncharge; |
4111 | /* remember freed charge and uncharge it later */ | |
7ffd4ca7 | 4112 | batch->nr_pages++; |
569b846d | 4113 | if (uncharge_memsw) |
7ffd4ca7 | 4114 | batch->memsw_nr_pages++; |
569b846d KH |
4115 | return; |
4116 | direct_uncharge: | |
c0ff4b85 | 4117 | res_counter_uncharge(&memcg->res, nr_pages * PAGE_SIZE); |
569b846d | 4118 | if (uncharge_memsw) |
c0ff4b85 R |
4119 | res_counter_uncharge(&memcg->memsw, nr_pages * PAGE_SIZE); |
4120 | if (unlikely(batch->memcg != memcg)) | |
4121 | memcg_oom_recover(memcg); | |
569b846d | 4122 | } |
7a81b88c | 4123 | |
8a9f3ccd | 4124 | /* |
69029cd5 | 4125 | * uncharge if !page_mapped(page) |
8a9f3ccd | 4126 | */ |
8c7c6e34 | 4127 | static struct mem_cgroup * |
0030f535 JW |
4128 | __mem_cgroup_uncharge_common(struct page *page, enum charge_type ctype, |
4129 | bool end_migration) | |
8a9f3ccd | 4130 | { |
c0ff4b85 | 4131 | struct mem_cgroup *memcg = NULL; |
7ec99d62 JW |
4132 | unsigned int nr_pages = 1; |
4133 | struct page_cgroup *pc; | |
b2402857 | 4134 | bool anon; |
8a9f3ccd | 4135 | |
f8d66542 | 4136 | if (mem_cgroup_disabled()) |
8c7c6e34 | 4137 | return NULL; |
4077960e | 4138 | |
37c2ac78 | 4139 | if (PageTransHuge(page)) { |
7ec99d62 | 4140 | nr_pages <<= compound_order(page); |
37c2ac78 AA |
4141 | VM_BUG_ON(!PageTransHuge(page)); |
4142 | } | |
8697d331 | 4143 | /* |
3c541e14 | 4144 | * Check if our page_cgroup is valid |
8697d331 | 4145 | */ |
52d4b9ac | 4146 | pc = lookup_page_cgroup(page); |
cfa44946 | 4147 | if (unlikely(!PageCgroupUsed(pc))) |
8c7c6e34 | 4148 | return NULL; |
b9c565d5 | 4149 | |
52d4b9ac | 4150 | lock_page_cgroup(pc); |
d13d1443 | 4151 | |
c0ff4b85 | 4152 | memcg = pc->mem_cgroup; |
8c7c6e34 | 4153 | |
d13d1443 KH |
4154 | if (!PageCgroupUsed(pc)) |
4155 | goto unlock_out; | |
4156 | ||
b2402857 KH |
4157 | anon = PageAnon(page); |
4158 | ||
d13d1443 | 4159 | switch (ctype) { |
41326c17 | 4160 | case MEM_CGROUP_CHARGE_TYPE_ANON: |
2ff76f11 KH |
4161 | /* |
4162 | * Generally PageAnon tells if it's the anon statistics to be | |
4163 | * updated; but sometimes e.g. mem_cgroup_uncharge_page() is | |
4164 | * used before page reached the stage of being marked PageAnon. | |
4165 | */ | |
b2402857 KH |
4166 | anon = true; |
4167 | /* fallthrough */ | |
8a9478ca | 4168 | case MEM_CGROUP_CHARGE_TYPE_DROP: |
ac39cf8c | 4169 | /* See mem_cgroup_prepare_migration() */ |
0030f535 JW |
4170 | if (page_mapped(page)) |
4171 | goto unlock_out; | |
4172 | /* | |
4173 | * Pages under migration may not be uncharged. But | |
4174 | * end_migration() /must/ be the one uncharging the | |
4175 | * unused post-migration page and so it has to call | |
4176 | * here with the migration bit still set. See the | |
4177 | * res_counter handling below. | |
4178 | */ | |
4179 | if (!end_migration && PageCgroupMigration(pc)) | |
d13d1443 KH |
4180 | goto unlock_out; |
4181 | break; | |
4182 | case MEM_CGROUP_CHARGE_TYPE_SWAPOUT: | |
4183 | if (!PageAnon(page)) { /* Shared memory */ | |
4184 | if (page->mapping && !page_is_file_cache(page)) | |
4185 | goto unlock_out; | |
4186 | } else if (page_mapped(page)) /* Anon */ | |
4187 | goto unlock_out; | |
4188 | break; | |
4189 | default: | |
4190 | break; | |
52d4b9ac | 4191 | } |
d13d1443 | 4192 | |
b070e65c | 4193 | mem_cgroup_charge_statistics(memcg, page, anon, -nr_pages); |
04046e1a | 4194 | |
52d4b9ac | 4195 | ClearPageCgroupUsed(pc); |
544122e5 KH |
4196 | /* |
4197 | * pc->mem_cgroup is not cleared here. It will be accessed when it's | |
4198 | * freed from LRU. This is safe because uncharged page is expected not | |
4199 | * to be reused (freed soon). Exception is SwapCache, it's handled by | |
4200 | * special functions. | |
4201 | */ | |
b9c565d5 | 4202 | |
52d4b9ac | 4203 | unlock_page_cgroup(pc); |
f75ca962 | 4204 | /* |
c0ff4b85 | 4205 | * even after unlock, we have memcg->res.usage here and this memcg |
f75ca962 KH |
4206 | * will never be freed. |
4207 | */ | |
c0ff4b85 | 4208 | memcg_check_events(memcg, page); |
f75ca962 | 4209 | if (do_swap_account && ctype == MEM_CGROUP_CHARGE_TYPE_SWAPOUT) { |
c0ff4b85 R |
4210 | mem_cgroup_swap_statistics(memcg, true); |
4211 | mem_cgroup_get(memcg); | |
f75ca962 | 4212 | } |
0030f535 JW |
4213 | /* |
4214 | * Migration does not charge the res_counter for the | |
4215 | * replacement page, so leave it alone when phasing out the | |
4216 | * page that is unused after the migration. | |
4217 | */ | |
4218 | if (!end_migration && !mem_cgroup_is_root(memcg)) | |
c0ff4b85 | 4219 | mem_cgroup_do_uncharge(memcg, nr_pages, ctype); |
6d12e2d8 | 4220 | |
c0ff4b85 | 4221 | return memcg; |
d13d1443 KH |
4222 | |
4223 | unlock_out: | |
4224 | unlock_page_cgroup(pc); | |
8c7c6e34 | 4225 | return NULL; |
3c541e14 BS |
4226 | } |
4227 | ||
69029cd5 KH |
4228 | void mem_cgroup_uncharge_page(struct page *page) |
4229 | { | |
52d4b9ac KH |
4230 | /* early check. */ |
4231 | if (page_mapped(page)) | |
4232 | return; | |
40f23a21 | 4233 | VM_BUG_ON(page->mapping && !PageAnon(page)); |
28ccddf7 JW |
4234 | /* |
4235 | * If the page is in swap cache, uncharge should be deferred | |
4236 | * to the swap path, which also properly accounts swap usage | |
4237 | * and handles memcg lifetime. | |
4238 | * | |
4239 | * Note that this check is not stable and reclaim may add the | |
4240 | * page to swap cache at any time after this. However, if the | |
4241 | * page is not in swap cache by the time page->mapcount hits | |
4242 | * 0, there won't be any page table references to the swap | |
4243 | * slot, and reclaim will free it and not actually write the | |
4244 | * page to disk. | |
4245 | */ | |
0c59b89c JW |
4246 | if (PageSwapCache(page)) |
4247 | return; | |
0030f535 | 4248 | __mem_cgroup_uncharge_common(page, MEM_CGROUP_CHARGE_TYPE_ANON, false); |
69029cd5 KH |
4249 | } |
4250 | ||
4251 | void mem_cgroup_uncharge_cache_page(struct page *page) | |
4252 | { | |
4253 | VM_BUG_ON(page_mapped(page)); | |
b7abea96 | 4254 | VM_BUG_ON(page->mapping); |
0030f535 | 4255 | __mem_cgroup_uncharge_common(page, MEM_CGROUP_CHARGE_TYPE_CACHE, false); |
69029cd5 KH |
4256 | } |
4257 | ||
569b846d KH |
4258 | /* |
4259 | * Batch_start/batch_end is called in unmap_page_range/invlidate/trucate. | |
4260 | * In that cases, pages are freed continuously and we can expect pages | |
4261 | * are in the same memcg. All these calls itself limits the number of | |
4262 | * pages freed at once, then uncharge_start/end() is called properly. | |
4263 | * This may be called prural(2) times in a context, | |
4264 | */ | |
4265 | ||
4266 | void mem_cgroup_uncharge_start(void) | |
4267 | { | |
4268 | current->memcg_batch.do_batch++; | |
4269 | /* We can do nest. */ | |
4270 | if (current->memcg_batch.do_batch == 1) { | |
4271 | current->memcg_batch.memcg = NULL; | |
7ffd4ca7 JW |
4272 | current->memcg_batch.nr_pages = 0; |
4273 | current->memcg_batch.memsw_nr_pages = 0; | |
569b846d KH |
4274 | } |
4275 | } | |
4276 | ||
4277 | void mem_cgroup_uncharge_end(void) | |
4278 | { | |
4279 | struct memcg_batch_info *batch = ¤t->memcg_batch; | |
4280 | ||
4281 | if (!batch->do_batch) | |
4282 | return; | |
4283 | ||
4284 | batch->do_batch--; | |
4285 | if (batch->do_batch) /* If stacked, do nothing. */ | |
4286 | return; | |
4287 | ||
4288 | if (!batch->memcg) | |
4289 | return; | |
4290 | /* | |
4291 | * This "batch->memcg" is valid without any css_get/put etc... | |
4292 | * bacause we hide charges behind us. | |
4293 | */ | |
7ffd4ca7 JW |
4294 | if (batch->nr_pages) |
4295 | res_counter_uncharge(&batch->memcg->res, | |
4296 | batch->nr_pages * PAGE_SIZE); | |
4297 | if (batch->memsw_nr_pages) | |
4298 | res_counter_uncharge(&batch->memcg->memsw, | |
4299 | batch->memsw_nr_pages * PAGE_SIZE); | |
3c11ecf4 | 4300 | memcg_oom_recover(batch->memcg); |
569b846d KH |
4301 | /* forget this pointer (for sanity check) */ |
4302 | batch->memcg = NULL; | |
4303 | } | |
4304 | ||
e767e056 | 4305 | #ifdef CONFIG_SWAP |
8c7c6e34 | 4306 | /* |
e767e056 | 4307 | * called after __delete_from_swap_cache() and drop "page" account. |
8c7c6e34 KH |
4308 | * memcg information is recorded to swap_cgroup of "ent" |
4309 | */ | |
8a9478ca KH |
4310 | void |
4311 | mem_cgroup_uncharge_swapcache(struct page *page, swp_entry_t ent, bool swapout) | |
8c7c6e34 KH |
4312 | { |
4313 | struct mem_cgroup *memcg; | |
8a9478ca KH |
4314 | int ctype = MEM_CGROUP_CHARGE_TYPE_SWAPOUT; |
4315 | ||
4316 | if (!swapout) /* this was a swap cache but the swap is unused ! */ | |
4317 | ctype = MEM_CGROUP_CHARGE_TYPE_DROP; | |
4318 | ||
0030f535 | 4319 | memcg = __mem_cgroup_uncharge_common(page, ctype, false); |
8c7c6e34 | 4320 | |
f75ca962 KH |
4321 | /* |
4322 | * record memcg information, if swapout && memcg != NULL, | |
4323 | * mem_cgroup_get() was called in uncharge(). | |
4324 | */ | |
4325 | if (do_swap_account && swapout && memcg) | |
a3b2d692 | 4326 | swap_cgroup_record(ent, css_id(&memcg->css)); |
8c7c6e34 | 4327 | } |
e767e056 | 4328 | #endif |
8c7c6e34 | 4329 | |
c255a458 | 4330 | #ifdef CONFIG_MEMCG_SWAP |
8c7c6e34 KH |
4331 | /* |
4332 | * called from swap_entry_free(). remove record in swap_cgroup and | |
4333 | * uncharge "memsw" account. | |
4334 | */ | |
4335 | void mem_cgroup_uncharge_swap(swp_entry_t ent) | |
d13d1443 | 4336 | { |
8c7c6e34 | 4337 | struct mem_cgroup *memcg; |
a3b2d692 | 4338 | unsigned short id; |
8c7c6e34 KH |
4339 | |
4340 | if (!do_swap_account) | |
4341 | return; | |
4342 | ||
a3b2d692 KH |
4343 | id = swap_cgroup_record(ent, 0); |
4344 | rcu_read_lock(); | |
4345 | memcg = mem_cgroup_lookup(id); | |
8c7c6e34 | 4346 | if (memcg) { |
a3b2d692 KH |
4347 | /* |
4348 | * We uncharge this because swap is freed. | |
4349 | * This memcg can be obsolete one. We avoid calling css_tryget | |
4350 | */ | |
0c3e73e8 | 4351 | if (!mem_cgroup_is_root(memcg)) |
4e649152 | 4352 | res_counter_uncharge(&memcg->memsw, PAGE_SIZE); |
0c3e73e8 | 4353 | mem_cgroup_swap_statistics(memcg, false); |
8c7c6e34 KH |
4354 | mem_cgroup_put(memcg); |
4355 | } | |
a3b2d692 | 4356 | rcu_read_unlock(); |
d13d1443 | 4357 | } |
02491447 DN |
4358 | |
4359 | /** | |
4360 | * mem_cgroup_move_swap_account - move swap charge and swap_cgroup's record. | |
4361 | * @entry: swap entry to be moved | |
4362 | * @from: mem_cgroup which the entry is moved from | |
4363 | * @to: mem_cgroup which the entry is moved to | |
4364 | * | |
4365 | * It succeeds only when the swap_cgroup's record for this entry is the same | |
4366 | * as the mem_cgroup's id of @from. | |
4367 | * | |
4368 | * Returns 0 on success, -EINVAL on failure. | |
4369 | * | |
4370 | * The caller must have charged to @to, IOW, called res_counter_charge() about | |
4371 | * both res and memsw, and called css_get(). | |
4372 | */ | |
4373 | static int mem_cgroup_move_swap_account(swp_entry_t entry, | |
e91cbb42 | 4374 | struct mem_cgroup *from, struct mem_cgroup *to) |
02491447 DN |
4375 | { |
4376 | unsigned short old_id, new_id; | |
4377 | ||
4378 | old_id = css_id(&from->css); | |
4379 | new_id = css_id(&to->css); | |
4380 | ||
4381 | if (swap_cgroup_cmpxchg(entry, old_id, new_id) == old_id) { | |
02491447 | 4382 | mem_cgroup_swap_statistics(from, false); |
483c30b5 | 4383 | mem_cgroup_swap_statistics(to, true); |
02491447 | 4384 | /* |
483c30b5 DN |
4385 | * This function is only called from task migration context now. |
4386 | * It postpones res_counter and refcount handling till the end | |
4387 | * of task migration(mem_cgroup_clear_mc()) for performance | |
4388 | * improvement. But we cannot postpone mem_cgroup_get(to) | |
4389 | * because if the process that has been moved to @to does | |
4390 | * swap-in, the refcount of @to might be decreased to 0. | |
02491447 | 4391 | */ |
02491447 | 4392 | mem_cgroup_get(to); |
02491447 DN |
4393 | return 0; |
4394 | } | |
4395 | return -EINVAL; | |
4396 | } | |
4397 | #else | |
4398 | static inline int mem_cgroup_move_swap_account(swp_entry_t entry, | |
e91cbb42 | 4399 | struct mem_cgroup *from, struct mem_cgroup *to) |
02491447 DN |
4400 | { |
4401 | return -EINVAL; | |
4402 | } | |
8c7c6e34 | 4403 | #endif |
d13d1443 | 4404 | |
ae41be37 | 4405 | /* |
01b1ae63 KH |
4406 | * Before starting migration, account PAGE_SIZE to mem_cgroup that the old |
4407 | * page belongs to. | |
ae41be37 | 4408 | */ |
0030f535 JW |
4409 | void mem_cgroup_prepare_migration(struct page *page, struct page *newpage, |
4410 | struct mem_cgroup **memcgp) | |
ae41be37 | 4411 | { |
c0ff4b85 | 4412 | struct mem_cgroup *memcg = NULL; |
b32967ff | 4413 | unsigned int nr_pages = 1; |
7ec99d62 | 4414 | struct page_cgroup *pc; |
ac39cf8c | 4415 | enum charge_type ctype; |
8869b8f6 | 4416 | |
72835c86 | 4417 | *memcgp = NULL; |
56039efa | 4418 | |
f8d66542 | 4419 | if (mem_cgroup_disabled()) |
0030f535 | 4420 | return; |
4077960e | 4421 | |
b32967ff MG |
4422 | if (PageTransHuge(page)) |
4423 | nr_pages <<= compound_order(page); | |
4424 | ||
52d4b9ac KH |
4425 | pc = lookup_page_cgroup(page); |
4426 | lock_page_cgroup(pc); | |
4427 | if (PageCgroupUsed(pc)) { | |
c0ff4b85 R |
4428 | memcg = pc->mem_cgroup; |
4429 | css_get(&memcg->css); | |
ac39cf8c | 4430 | /* |
4431 | * At migrating an anonymous page, its mapcount goes down | |
4432 | * to 0 and uncharge() will be called. But, even if it's fully | |
4433 | * unmapped, migration may fail and this page has to be | |
4434 | * charged again. We set MIGRATION flag here and delay uncharge | |
4435 | * until end_migration() is called | |
4436 | * | |
4437 | * Corner Case Thinking | |
4438 | * A) | |
4439 | * When the old page was mapped as Anon and it's unmap-and-freed | |
4440 | * while migration was ongoing. | |
4441 | * If unmap finds the old page, uncharge() of it will be delayed | |
4442 | * until end_migration(). If unmap finds a new page, it's | |
4443 | * uncharged when it make mapcount to be 1->0. If unmap code | |
4444 | * finds swap_migration_entry, the new page will not be mapped | |
4445 | * and end_migration() will find it(mapcount==0). | |
4446 | * | |
4447 | * B) | |
4448 | * When the old page was mapped but migraion fails, the kernel | |
4449 | * remaps it. A charge for it is kept by MIGRATION flag even | |
4450 | * if mapcount goes down to 0. We can do remap successfully | |
4451 | * without charging it again. | |
4452 | * | |
4453 | * C) | |
4454 | * The "old" page is under lock_page() until the end of | |
4455 | * migration, so, the old page itself will not be swapped-out. | |
4456 | * If the new page is swapped out before end_migraton, our | |
4457 | * hook to usual swap-out path will catch the event. | |
4458 | */ | |
4459 | if (PageAnon(page)) | |
4460 | SetPageCgroupMigration(pc); | |
e8589cc1 | 4461 | } |
52d4b9ac | 4462 | unlock_page_cgroup(pc); |
ac39cf8c | 4463 | /* |
4464 | * If the page is not charged at this point, | |
4465 | * we return here. | |
4466 | */ | |
c0ff4b85 | 4467 | if (!memcg) |
0030f535 | 4468 | return; |
01b1ae63 | 4469 | |
72835c86 | 4470 | *memcgp = memcg; |
ac39cf8c | 4471 | /* |
4472 | * We charge new page before it's used/mapped. So, even if unlock_page() | |
4473 | * is called before end_migration, we can catch all events on this new | |
4474 | * page. In the case new page is migrated but not remapped, new page's | |
4475 | * mapcount will be finally 0 and we call uncharge in end_migration(). | |
4476 | */ | |
ac39cf8c | 4477 | if (PageAnon(page)) |
41326c17 | 4478 | ctype = MEM_CGROUP_CHARGE_TYPE_ANON; |
ac39cf8c | 4479 | else |
62ba7442 | 4480 | ctype = MEM_CGROUP_CHARGE_TYPE_CACHE; |
0030f535 JW |
4481 | /* |
4482 | * The page is committed to the memcg, but it's not actually | |
4483 | * charged to the res_counter since we plan on replacing the | |
4484 | * old one and only one page is going to be left afterwards. | |
4485 | */ | |
b32967ff | 4486 | __mem_cgroup_commit_charge(memcg, newpage, nr_pages, ctype, false); |
ae41be37 | 4487 | } |
8869b8f6 | 4488 | |
69029cd5 | 4489 | /* remove redundant charge if migration failed*/ |
c0ff4b85 | 4490 | void mem_cgroup_end_migration(struct mem_cgroup *memcg, |
50de1dd9 | 4491 | struct page *oldpage, struct page *newpage, bool migration_ok) |
ae41be37 | 4492 | { |
ac39cf8c | 4493 | struct page *used, *unused; |
01b1ae63 | 4494 | struct page_cgroup *pc; |
b2402857 | 4495 | bool anon; |
01b1ae63 | 4496 | |
c0ff4b85 | 4497 | if (!memcg) |
01b1ae63 | 4498 | return; |
b25ed609 | 4499 | |
50de1dd9 | 4500 | if (!migration_ok) { |
ac39cf8c | 4501 | used = oldpage; |
4502 | unused = newpage; | |
01b1ae63 | 4503 | } else { |
ac39cf8c | 4504 | used = newpage; |
01b1ae63 KH |
4505 | unused = oldpage; |
4506 | } | |
0030f535 | 4507 | anon = PageAnon(used); |
7d188958 JW |
4508 | __mem_cgroup_uncharge_common(unused, |
4509 | anon ? MEM_CGROUP_CHARGE_TYPE_ANON | |
4510 | : MEM_CGROUP_CHARGE_TYPE_CACHE, | |
4511 | true); | |
0030f535 | 4512 | css_put(&memcg->css); |
69029cd5 | 4513 | /* |
ac39cf8c | 4514 | * We disallowed uncharge of pages under migration because mapcount |
4515 | * of the page goes down to zero, temporarly. | |
4516 | * Clear the flag and check the page should be charged. | |
01b1ae63 | 4517 | */ |
ac39cf8c | 4518 | pc = lookup_page_cgroup(oldpage); |
4519 | lock_page_cgroup(pc); | |
4520 | ClearPageCgroupMigration(pc); | |
4521 | unlock_page_cgroup(pc); | |
ac39cf8c | 4522 | |
01b1ae63 | 4523 | /* |
ac39cf8c | 4524 | * If a page is a file cache, radix-tree replacement is very atomic |
4525 | * and we can skip this check. When it was an Anon page, its mapcount | |
4526 | * goes down to 0. But because we added MIGRATION flage, it's not | |
4527 | * uncharged yet. There are several case but page->mapcount check | |
4528 | * and USED bit check in mem_cgroup_uncharge_page() will do enough | |
4529 | * check. (see prepare_charge() also) | |
69029cd5 | 4530 | */ |
b2402857 | 4531 | if (anon) |
ac39cf8c | 4532 | mem_cgroup_uncharge_page(used); |
ae41be37 | 4533 | } |
78fb7466 | 4534 | |
ab936cbc KH |
4535 | /* |
4536 | * At replace page cache, newpage is not under any memcg but it's on | |
4537 | * LRU. So, this function doesn't touch res_counter but handles LRU | |
4538 | * in correct way. Both pages are locked so we cannot race with uncharge. | |
4539 | */ | |
4540 | void mem_cgroup_replace_page_cache(struct page *oldpage, | |
4541 | struct page *newpage) | |
4542 | { | |
bde05d1c | 4543 | struct mem_cgroup *memcg = NULL; |
ab936cbc | 4544 | struct page_cgroup *pc; |
ab936cbc | 4545 | enum charge_type type = MEM_CGROUP_CHARGE_TYPE_CACHE; |
ab936cbc KH |
4546 | |
4547 | if (mem_cgroup_disabled()) | |
4548 | return; | |
4549 | ||
4550 | pc = lookup_page_cgroup(oldpage); | |
4551 | /* fix accounting on old pages */ | |
4552 | lock_page_cgroup(pc); | |
bde05d1c HD |
4553 | if (PageCgroupUsed(pc)) { |
4554 | memcg = pc->mem_cgroup; | |
b070e65c | 4555 | mem_cgroup_charge_statistics(memcg, oldpage, false, -1); |
bde05d1c HD |
4556 | ClearPageCgroupUsed(pc); |
4557 | } | |
ab936cbc KH |
4558 | unlock_page_cgroup(pc); |
4559 | ||
bde05d1c HD |
4560 | /* |
4561 | * When called from shmem_replace_page(), in some cases the | |
4562 | * oldpage has already been charged, and in some cases not. | |
4563 | */ | |
4564 | if (!memcg) | |
4565 | return; | |
ab936cbc KH |
4566 | /* |
4567 | * Even if newpage->mapping was NULL before starting replacement, | |
4568 | * the newpage may be on LRU(or pagevec for LRU) already. We lock | |
4569 | * LRU while we overwrite pc->mem_cgroup. | |
4570 | */ | |
ce587e65 | 4571 | __mem_cgroup_commit_charge(memcg, newpage, 1, type, true); |
ab936cbc KH |
4572 | } |
4573 | ||
f212ad7c DN |
4574 | #ifdef CONFIG_DEBUG_VM |
4575 | static struct page_cgroup *lookup_page_cgroup_used(struct page *page) | |
4576 | { | |
4577 | struct page_cgroup *pc; | |
4578 | ||
4579 | pc = lookup_page_cgroup(page); | |
cfa44946 JW |
4580 | /* |
4581 | * Can be NULL while feeding pages into the page allocator for | |
4582 | * the first time, i.e. during boot or memory hotplug; | |
4583 | * or when mem_cgroup_disabled(). | |
4584 | */ | |
f212ad7c DN |
4585 | if (likely(pc) && PageCgroupUsed(pc)) |
4586 | return pc; | |
4587 | return NULL; | |
4588 | } | |
4589 | ||
4590 | bool mem_cgroup_bad_page_check(struct page *page) | |
4591 | { | |
4592 | if (mem_cgroup_disabled()) | |
4593 | return false; | |
4594 | ||
4595 | return lookup_page_cgroup_used(page) != NULL; | |
4596 | } | |
4597 | ||
4598 | void mem_cgroup_print_bad_page(struct page *page) | |
4599 | { | |
4600 | struct page_cgroup *pc; | |
4601 | ||
4602 | pc = lookup_page_cgroup_used(page); | |
4603 | if (pc) { | |
d045197f AM |
4604 | pr_alert("pc:%p pc->flags:%lx pc->mem_cgroup:%p\n", |
4605 | pc, pc->flags, pc->mem_cgroup); | |
f212ad7c DN |
4606 | } |
4607 | } | |
4608 | #endif | |
4609 | ||
d38d2a75 | 4610 | static int mem_cgroup_resize_limit(struct mem_cgroup *memcg, |
8c7c6e34 | 4611 | unsigned long long val) |
628f4235 | 4612 | { |
81d39c20 | 4613 | int retry_count; |
3c11ecf4 | 4614 | u64 memswlimit, memlimit; |
628f4235 | 4615 | int ret = 0; |
81d39c20 KH |
4616 | int children = mem_cgroup_count_children(memcg); |
4617 | u64 curusage, oldusage; | |
3c11ecf4 | 4618 | int enlarge; |
81d39c20 KH |
4619 | |
4620 | /* | |
4621 | * For keeping hierarchical_reclaim simple, how long we should retry | |
4622 | * is depends on callers. We set our retry-count to be function | |
4623 | * of # of children which we should visit in this loop. | |
4624 | */ | |
4625 | retry_count = MEM_CGROUP_RECLAIM_RETRIES * children; | |
4626 | ||
4627 | oldusage = res_counter_read_u64(&memcg->res, RES_USAGE); | |
628f4235 | 4628 | |
3c11ecf4 | 4629 | enlarge = 0; |
8c7c6e34 | 4630 | while (retry_count) { |
628f4235 KH |
4631 | if (signal_pending(current)) { |
4632 | ret = -EINTR; | |
4633 | break; | |
4634 | } | |
8c7c6e34 KH |
4635 | /* |
4636 | * Rather than hide all in some function, I do this in | |
4637 | * open coded manner. You see what this really does. | |
aaad153e | 4638 | * We have to guarantee memcg->res.limit <= memcg->memsw.limit. |
8c7c6e34 KH |
4639 | */ |
4640 | mutex_lock(&set_limit_mutex); | |
4641 | memswlimit = res_counter_read_u64(&memcg->memsw, RES_LIMIT); | |
4642 | if (memswlimit < val) { | |
4643 | ret = -EINVAL; | |
4644 | mutex_unlock(&set_limit_mutex); | |
628f4235 KH |
4645 | break; |
4646 | } | |
3c11ecf4 KH |
4647 | |
4648 | memlimit = res_counter_read_u64(&memcg->res, RES_LIMIT); | |
4649 | if (memlimit < val) | |
4650 | enlarge = 1; | |
4651 | ||
8c7c6e34 | 4652 | ret = res_counter_set_limit(&memcg->res, val); |
22a668d7 KH |
4653 | if (!ret) { |
4654 | if (memswlimit == val) | |
4655 | memcg->memsw_is_minimum = true; | |
4656 | else | |
4657 | memcg->memsw_is_minimum = false; | |
4658 | } | |
8c7c6e34 KH |
4659 | mutex_unlock(&set_limit_mutex); |
4660 | ||
4661 | if (!ret) | |
4662 | break; | |
4663 | ||
5660048c JW |
4664 | mem_cgroup_reclaim(memcg, GFP_KERNEL, |
4665 | MEM_CGROUP_RECLAIM_SHRINK); | |
81d39c20 KH |
4666 | curusage = res_counter_read_u64(&memcg->res, RES_USAGE); |
4667 | /* Usage is reduced ? */ | |
4668 | if (curusage >= oldusage) | |
4669 | retry_count--; | |
4670 | else | |
4671 | oldusage = curusage; | |
8c7c6e34 | 4672 | } |
3c11ecf4 KH |
4673 | if (!ret && enlarge) |
4674 | memcg_oom_recover(memcg); | |
14797e23 | 4675 | |
8c7c6e34 KH |
4676 | return ret; |
4677 | } | |
4678 | ||
338c8431 LZ |
4679 | static int mem_cgroup_resize_memsw_limit(struct mem_cgroup *memcg, |
4680 | unsigned long long val) | |
8c7c6e34 | 4681 | { |
81d39c20 | 4682 | int retry_count; |
3c11ecf4 | 4683 | u64 memlimit, memswlimit, oldusage, curusage; |
81d39c20 KH |
4684 | int children = mem_cgroup_count_children(memcg); |
4685 | int ret = -EBUSY; | |
3c11ecf4 | 4686 | int enlarge = 0; |
8c7c6e34 | 4687 | |
81d39c20 KH |
4688 | /* see mem_cgroup_resize_res_limit */ |
4689 | retry_count = children * MEM_CGROUP_RECLAIM_RETRIES; | |
4690 | oldusage = res_counter_read_u64(&memcg->memsw, RES_USAGE); | |
8c7c6e34 KH |
4691 | while (retry_count) { |
4692 | if (signal_pending(current)) { | |
4693 | ret = -EINTR; | |
4694 | break; | |
4695 | } | |
4696 | /* | |
4697 | * Rather than hide all in some function, I do this in | |
4698 | * open coded manner. You see what this really does. | |
aaad153e | 4699 | * We have to guarantee memcg->res.limit <= memcg->memsw.limit. |
8c7c6e34 KH |
4700 | */ |
4701 | mutex_lock(&set_limit_mutex); | |
4702 | memlimit = res_counter_read_u64(&memcg->res, RES_LIMIT); | |
4703 | if (memlimit > val) { | |
4704 | ret = -EINVAL; | |
4705 | mutex_unlock(&set_limit_mutex); | |
4706 | break; | |
4707 | } | |
3c11ecf4 KH |
4708 | memswlimit = res_counter_read_u64(&memcg->memsw, RES_LIMIT); |
4709 | if (memswlimit < val) | |
4710 | enlarge = 1; | |
8c7c6e34 | 4711 | ret = res_counter_set_limit(&memcg->memsw, val); |
22a668d7 KH |
4712 | if (!ret) { |
4713 | if (memlimit == val) | |
4714 | memcg->memsw_is_minimum = true; | |
4715 | else | |
4716 | memcg->memsw_is_minimum = false; | |
4717 | } | |
8c7c6e34 KH |
4718 | mutex_unlock(&set_limit_mutex); |
4719 | ||
4720 | if (!ret) | |
4721 | break; | |
4722 | ||
5660048c JW |
4723 | mem_cgroup_reclaim(memcg, GFP_KERNEL, |
4724 | MEM_CGROUP_RECLAIM_NOSWAP | | |
4725 | MEM_CGROUP_RECLAIM_SHRINK); | |
8c7c6e34 | 4726 | curusage = res_counter_read_u64(&memcg->memsw, RES_USAGE); |
81d39c20 | 4727 | /* Usage is reduced ? */ |
8c7c6e34 | 4728 | if (curusage >= oldusage) |
628f4235 | 4729 | retry_count--; |
81d39c20 KH |
4730 | else |
4731 | oldusage = curusage; | |
628f4235 | 4732 | } |
3c11ecf4 KH |
4733 | if (!ret && enlarge) |
4734 | memcg_oom_recover(memcg); | |
628f4235 KH |
4735 | return ret; |
4736 | } | |
4737 | ||
4e416953 | 4738 | unsigned long mem_cgroup_soft_limit_reclaim(struct zone *zone, int order, |
0ae5e89c YH |
4739 | gfp_t gfp_mask, |
4740 | unsigned long *total_scanned) | |
4e416953 BS |
4741 | { |
4742 | unsigned long nr_reclaimed = 0; | |
4743 | struct mem_cgroup_per_zone *mz, *next_mz = NULL; | |
4744 | unsigned long reclaimed; | |
4745 | int loop = 0; | |
4746 | struct mem_cgroup_tree_per_zone *mctz; | |
ef8745c1 | 4747 | unsigned long long excess; |
0ae5e89c | 4748 | unsigned long nr_scanned; |
4e416953 BS |
4749 | |
4750 | if (order > 0) | |
4751 | return 0; | |
4752 | ||
00918b6a | 4753 | mctz = soft_limit_tree_node_zone(zone_to_nid(zone), zone_idx(zone)); |
4e416953 BS |
4754 | /* |
4755 | * This loop can run a while, specially if mem_cgroup's continuously | |
4756 | * keep exceeding their soft limit and putting the system under | |
4757 | * pressure | |
4758 | */ | |
4759 | do { | |
4760 | if (next_mz) | |
4761 | mz = next_mz; | |
4762 | else | |
4763 | mz = mem_cgroup_largest_soft_limit_node(mctz); | |
4764 | if (!mz) | |
4765 | break; | |
4766 | ||
0ae5e89c | 4767 | nr_scanned = 0; |
d79154bb | 4768 | reclaimed = mem_cgroup_soft_reclaim(mz->memcg, zone, |
5660048c | 4769 | gfp_mask, &nr_scanned); |
4e416953 | 4770 | nr_reclaimed += reclaimed; |
0ae5e89c | 4771 | *total_scanned += nr_scanned; |
4e416953 BS |
4772 | spin_lock(&mctz->lock); |
4773 | ||
4774 | /* | |
4775 | * If we failed to reclaim anything from this memory cgroup | |
4776 | * it is time to move on to the next cgroup | |
4777 | */ | |
4778 | next_mz = NULL; | |
4779 | if (!reclaimed) { | |
4780 | do { | |
4781 | /* | |
4782 | * Loop until we find yet another one. | |
4783 | * | |
4784 | * By the time we get the soft_limit lock | |
4785 | * again, someone might have aded the | |
4786 | * group back on the RB tree. Iterate to | |
4787 | * make sure we get a different mem. | |
4788 | * mem_cgroup_largest_soft_limit_node returns | |
4789 | * NULL if no other cgroup is present on | |
4790 | * the tree | |
4791 | */ | |
4792 | next_mz = | |
4793 | __mem_cgroup_largest_soft_limit_node(mctz); | |
39cc98f1 | 4794 | if (next_mz == mz) |
d79154bb | 4795 | css_put(&next_mz->memcg->css); |
39cc98f1 | 4796 | else /* next_mz == NULL or other memcg */ |
4e416953 BS |
4797 | break; |
4798 | } while (1); | |
4799 | } | |
d79154bb HD |
4800 | __mem_cgroup_remove_exceeded(mz->memcg, mz, mctz); |
4801 | excess = res_counter_soft_limit_excess(&mz->memcg->res); | |
4e416953 BS |
4802 | /* |
4803 | * One school of thought says that we should not add | |
4804 | * back the node to the tree if reclaim returns 0. | |
4805 | * But our reclaim could return 0, simply because due | |
4806 | * to priority we are exposing a smaller subset of | |
4807 | * memory to reclaim from. Consider this as a longer | |
4808 | * term TODO. | |
4809 | */ | |
ef8745c1 | 4810 | /* If excess == 0, no tree ops */ |
d79154bb | 4811 | __mem_cgroup_insert_exceeded(mz->memcg, mz, mctz, excess); |
4e416953 | 4812 | spin_unlock(&mctz->lock); |
d79154bb | 4813 | css_put(&mz->memcg->css); |
4e416953 BS |
4814 | loop++; |
4815 | /* | |
4816 | * Could not reclaim anything and there are no more | |
4817 | * mem cgroups to try or we seem to be looping without | |
4818 | * reclaiming anything. | |
4819 | */ | |
4820 | if (!nr_reclaimed && | |
4821 | (next_mz == NULL || | |
4822 | loop > MEM_CGROUP_MAX_SOFT_LIMIT_RECLAIM_LOOPS)) | |
4823 | break; | |
4824 | } while (!nr_reclaimed); | |
4825 | if (next_mz) | |
d79154bb | 4826 | css_put(&next_mz->memcg->css); |
4e416953 BS |
4827 | return nr_reclaimed; |
4828 | } | |
4829 | ||
2ef37d3f MH |
4830 | /** |
4831 | * mem_cgroup_force_empty_list - clears LRU of a group | |
4832 | * @memcg: group to clear | |
4833 | * @node: NUMA node | |
4834 | * @zid: zone id | |
4835 | * @lru: lru to to clear | |
4836 | * | |
3c935d18 | 4837 | * Traverse a specified page_cgroup list and try to drop them all. This doesn't |
2ef37d3f MH |
4838 | * reclaim the pages page themselves - pages are moved to the parent (or root) |
4839 | * group. | |
cc847582 | 4840 | */ |
2ef37d3f | 4841 | static void mem_cgroup_force_empty_list(struct mem_cgroup *memcg, |
08e552c6 | 4842 | int node, int zid, enum lru_list lru) |
cc847582 | 4843 | { |
bea8c150 | 4844 | struct lruvec *lruvec; |
2ef37d3f | 4845 | unsigned long flags; |
072c56c1 | 4846 | struct list_head *list; |
925b7673 JW |
4847 | struct page *busy; |
4848 | struct zone *zone; | |
072c56c1 | 4849 | |
08e552c6 | 4850 | zone = &NODE_DATA(node)->node_zones[zid]; |
bea8c150 HD |
4851 | lruvec = mem_cgroup_zone_lruvec(zone, memcg); |
4852 | list = &lruvec->lists[lru]; | |
cc847582 | 4853 | |
f817ed48 | 4854 | busy = NULL; |
2ef37d3f | 4855 | do { |
925b7673 | 4856 | struct page_cgroup *pc; |
5564e88b JW |
4857 | struct page *page; |
4858 | ||
08e552c6 | 4859 | spin_lock_irqsave(&zone->lru_lock, flags); |
f817ed48 | 4860 | if (list_empty(list)) { |
08e552c6 | 4861 | spin_unlock_irqrestore(&zone->lru_lock, flags); |
52d4b9ac | 4862 | break; |
f817ed48 | 4863 | } |
925b7673 JW |
4864 | page = list_entry(list->prev, struct page, lru); |
4865 | if (busy == page) { | |
4866 | list_move(&page->lru, list); | |
648bcc77 | 4867 | busy = NULL; |
08e552c6 | 4868 | spin_unlock_irqrestore(&zone->lru_lock, flags); |
f817ed48 KH |
4869 | continue; |
4870 | } | |
08e552c6 | 4871 | spin_unlock_irqrestore(&zone->lru_lock, flags); |
f817ed48 | 4872 | |
925b7673 | 4873 | pc = lookup_page_cgroup(page); |
5564e88b | 4874 | |
3c935d18 | 4875 | if (mem_cgroup_move_parent(page, pc, memcg)) { |
f817ed48 | 4876 | /* found lock contention or "pc" is obsolete. */ |
925b7673 | 4877 | busy = page; |
f817ed48 KH |
4878 | cond_resched(); |
4879 | } else | |
4880 | busy = NULL; | |
2ef37d3f | 4881 | } while (!list_empty(list)); |
cc847582 KH |
4882 | } |
4883 | ||
4884 | /* | |
c26251f9 MH |
4885 | * make mem_cgroup's charge to be 0 if there is no task by moving |
4886 | * all the charges and pages to the parent. | |
cc847582 | 4887 | * This enables deleting this mem_cgroup. |
c26251f9 MH |
4888 | * |
4889 | * Caller is responsible for holding css reference on the memcg. | |
cc847582 | 4890 | */ |
ab5196c2 | 4891 | static void mem_cgroup_reparent_charges(struct mem_cgroup *memcg) |
cc847582 | 4892 | { |
c26251f9 | 4893 | int node, zid; |
bea207c8 | 4894 | u64 usage; |
f817ed48 | 4895 | |
fce66477 | 4896 | do { |
52d4b9ac KH |
4897 | /* This is for making all *used* pages to be on LRU. */ |
4898 | lru_add_drain_all(); | |
c0ff4b85 | 4899 | drain_all_stock_sync(memcg); |
c0ff4b85 | 4900 | mem_cgroup_start_move(memcg); |
31aaea4a | 4901 | for_each_node_state(node, N_MEMORY) { |
2ef37d3f | 4902 | for (zid = 0; zid < MAX_NR_ZONES; zid++) { |
f156ab93 HD |
4903 | enum lru_list lru; |
4904 | for_each_lru(lru) { | |
2ef37d3f | 4905 | mem_cgroup_force_empty_list(memcg, |
f156ab93 | 4906 | node, zid, lru); |
f817ed48 | 4907 | } |
1ecaab2b | 4908 | } |
f817ed48 | 4909 | } |
c0ff4b85 R |
4910 | mem_cgroup_end_move(memcg); |
4911 | memcg_oom_recover(memcg); | |
52d4b9ac | 4912 | cond_resched(); |
f817ed48 | 4913 | |
2ef37d3f | 4914 | /* |
bea207c8 GC |
4915 | * Kernel memory may not necessarily be trackable to a specific |
4916 | * process. So they are not migrated, and therefore we can't | |
4917 | * expect their value to drop to 0 here. | |
4918 | * Having res filled up with kmem only is enough. | |
4919 | * | |
2ef37d3f MH |
4920 | * This is a safety check because mem_cgroup_force_empty_list |
4921 | * could have raced with mem_cgroup_replace_page_cache callers | |
4922 | * so the lru seemed empty but the page could have been added | |
4923 | * right after the check. RES_USAGE should be safe as we always | |
4924 | * charge before adding to the LRU. | |
4925 | */ | |
bea207c8 GC |
4926 | usage = res_counter_read_u64(&memcg->res, RES_USAGE) - |
4927 | res_counter_read_u64(&memcg->kmem, RES_USAGE); | |
4928 | } while (usage > 0); | |
c26251f9 MH |
4929 | } |
4930 | ||
b5f99b53 GC |
4931 | /* |
4932 | * This mainly exists for tests during the setting of set of use_hierarchy. | |
4933 | * Since this is the very setting we are changing, the current hierarchy value | |
4934 | * is meaningless | |
4935 | */ | |
4936 | static inline bool __memcg_has_children(struct mem_cgroup *memcg) | |
4937 | { | |
4938 | struct cgroup *pos; | |
4939 | ||
4940 | /* bounce at first found */ | |
4941 | cgroup_for_each_child(pos, memcg->css.cgroup) | |
4942 | return true; | |
4943 | return false; | |
4944 | } | |
4945 | ||
4946 | /* | |
0999821b GC |
4947 | * Must be called with memcg_create_mutex held, unless the cgroup is guaranteed |
4948 | * to be already dead (as in mem_cgroup_force_empty, for instance). This is | |
b5f99b53 GC |
4949 | * from mem_cgroup_count_children(), in the sense that we don't really care how |
4950 | * many children we have; we only need to know if we have any. It also counts | |
4951 | * any memcg without hierarchy as infertile. | |
4952 | */ | |
4953 | static inline bool memcg_has_children(struct mem_cgroup *memcg) | |
4954 | { | |
4955 | return memcg->use_hierarchy && __memcg_has_children(memcg); | |
4956 | } | |
4957 | ||
c26251f9 MH |
4958 | /* |
4959 | * Reclaims as many pages from the given memcg as possible and moves | |
4960 | * the rest to the parent. | |
4961 | * | |
4962 | * Caller is responsible for holding css reference for memcg. | |
4963 | */ | |
4964 | static int mem_cgroup_force_empty(struct mem_cgroup *memcg) | |
4965 | { | |
4966 | int nr_retries = MEM_CGROUP_RECLAIM_RETRIES; | |
4967 | struct cgroup *cgrp = memcg->css.cgroup; | |
f817ed48 | 4968 | |
c1e862c1 | 4969 | /* returns EBUSY if there is a task or if we come here twice. */ |
c26251f9 MH |
4970 | if (cgroup_task_count(cgrp) || !list_empty(&cgrp->children)) |
4971 | return -EBUSY; | |
4972 | ||
c1e862c1 KH |
4973 | /* we call try-to-free pages for make this cgroup empty */ |
4974 | lru_add_drain_all(); | |
f817ed48 | 4975 | /* try to free all pages in this cgroup */ |
569530fb | 4976 | while (nr_retries && res_counter_read_u64(&memcg->res, RES_USAGE) > 0) { |
f817ed48 | 4977 | int progress; |
c1e862c1 | 4978 | |
c26251f9 MH |
4979 | if (signal_pending(current)) |
4980 | return -EINTR; | |
4981 | ||
c0ff4b85 | 4982 | progress = try_to_free_mem_cgroup_pages(memcg, GFP_KERNEL, |
185efc0f | 4983 | false); |
c1e862c1 | 4984 | if (!progress) { |
f817ed48 | 4985 | nr_retries--; |
c1e862c1 | 4986 | /* maybe some writeback is necessary */ |
8aa7e847 | 4987 | congestion_wait(BLK_RW_ASYNC, HZ/10); |
c1e862c1 | 4988 | } |
f817ed48 KH |
4989 | |
4990 | } | |
08e552c6 | 4991 | lru_add_drain(); |
ab5196c2 MH |
4992 | mem_cgroup_reparent_charges(memcg); |
4993 | ||
4994 | return 0; | |
cc847582 KH |
4995 | } |
4996 | ||
6bbda35c | 4997 | static int mem_cgroup_force_empty_write(struct cgroup *cont, unsigned int event) |
c1e862c1 | 4998 | { |
c26251f9 MH |
4999 | struct mem_cgroup *memcg = mem_cgroup_from_cont(cont); |
5000 | int ret; | |
5001 | ||
d8423011 MH |
5002 | if (mem_cgroup_is_root(memcg)) |
5003 | return -EINVAL; | |
c26251f9 MH |
5004 | css_get(&memcg->css); |
5005 | ret = mem_cgroup_force_empty(memcg); | |
5006 | css_put(&memcg->css); | |
5007 | ||
5008 | return ret; | |
c1e862c1 KH |
5009 | } |
5010 | ||
5011 | ||
18f59ea7 BS |
5012 | static u64 mem_cgroup_hierarchy_read(struct cgroup *cont, struct cftype *cft) |
5013 | { | |
5014 | return mem_cgroup_from_cont(cont)->use_hierarchy; | |
5015 | } | |
5016 | ||
5017 | static int mem_cgroup_hierarchy_write(struct cgroup *cont, struct cftype *cft, | |
5018 | u64 val) | |
5019 | { | |
5020 | int retval = 0; | |
c0ff4b85 | 5021 | struct mem_cgroup *memcg = mem_cgroup_from_cont(cont); |
18f59ea7 | 5022 | struct cgroup *parent = cont->parent; |
c0ff4b85 | 5023 | struct mem_cgroup *parent_memcg = NULL; |
18f59ea7 BS |
5024 | |
5025 | if (parent) | |
c0ff4b85 | 5026 | parent_memcg = mem_cgroup_from_cont(parent); |
18f59ea7 | 5027 | |
0999821b | 5028 | mutex_lock(&memcg_create_mutex); |
567fb435 GC |
5029 | |
5030 | if (memcg->use_hierarchy == val) | |
5031 | goto out; | |
5032 | ||
18f59ea7 | 5033 | /* |
af901ca1 | 5034 | * If parent's use_hierarchy is set, we can't make any modifications |
18f59ea7 BS |
5035 | * in the child subtrees. If it is unset, then the change can |
5036 | * occur, provided the current cgroup has no children. | |
5037 | * | |
5038 | * For the root cgroup, parent_mem is NULL, we allow value to be | |
5039 | * set if there are no children. | |
5040 | */ | |
c0ff4b85 | 5041 | if ((!parent_memcg || !parent_memcg->use_hierarchy) && |
18f59ea7 | 5042 | (val == 1 || val == 0)) { |
b5f99b53 | 5043 | if (!__memcg_has_children(memcg)) |
c0ff4b85 | 5044 | memcg->use_hierarchy = val; |
18f59ea7 BS |
5045 | else |
5046 | retval = -EBUSY; | |
5047 | } else | |
5048 | retval = -EINVAL; | |
567fb435 GC |
5049 | |
5050 | out: | |
0999821b | 5051 | mutex_unlock(&memcg_create_mutex); |
18f59ea7 BS |
5052 | |
5053 | return retval; | |
5054 | } | |
5055 | ||
0c3e73e8 | 5056 | |
c0ff4b85 | 5057 | static unsigned long mem_cgroup_recursive_stat(struct mem_cgroup *memcg, |
7a159cc9 | 5058 | enum mem_cgroup_stat_index idx) |
0c3e73e8 | 5059 | { |
7d74b06f | 5060 | struct mem_cgroup *iter; |
7a159cc9 | 5061 | long val = 0; |
0c3e73e8 | 5062 | |
7a159cc9 | 5063 | /* Per-cpu values can be negative, use a signed accumulator */ |
c0ff4b85 | 5064 | for_each_mem_cgroup_tree(iter, memcg) |
7d74b06f KH |
5065 | val += mem_cgroup_read_stat(iter, idx); |
5066 | ||
5067 | if (val < 0) /* race ? */ | |
5068 | val = 0; | |
5069 | return val; | |
0c3e73e8 BS |
5070 | } |
5071 | ||
c0ff4b85 | 5072 | static inline u64 mem_cgroup_usage(struct mem_cgroup *memcg, bool swap) |
104f3928 | 5073 | { |
7d74b06f | 5074 | u64 val; |
104f3928 | 5075 | |
c0ff4b85 | 5076 | if (!mem_cgroup_is_root(memcg)) { |
104f3928 | 5077 | if (!swap) |
65c64ce8 | 5078 | return res_counter_read_u64(&memcg->res, RES_USAGE); |
104f3928 | 5079 | else |
65c64ce8 | 5080 | return res_counter_read_u64(&memcg->memsw, RES_USAGE); |
104f3928 KS |
5081 | } |
5082 | ||
b070e65c DR |
5083 | /* |
5084 | * Transparent hugepages are still accounted for in MEM_CGROUP_STAT_RSS | |
5085 | * as well as in MEM_CGROUP_STAT_RSS_HUGE. | |
5086 | */ | |
c0ff4b85 R |
5087 | val = mem_cgroup_recursive_stat(memcg, MEM_CGROUP_STAT_CACHE); |
5088 | val += mem_cgroup_recursive_stat(memcg, MEM_CGROUP_STAT_RSS); | |
104f3928 | 5089 | |
7d74b06f | 5090 | if (swap) |
bff6bb83 | 5091 | val += mem_cgroup_recursive_stat(memcg, MEM_CGROUP_STAT_SWAP); |
104f3928 KS |
5092 | |
5093 | return val << PAGE_SHIFT; | |
5094 | } | |
5095 | ||
af36f906 TH |
5096 | static ssize_t mem_cgroup_read(struct cgroup *cont, struct cftype *cft, |
5097 | struct file *file, char __user *buf, | |
5098 | size_t nbytes, loff_t *ppos) | |
8cdea7c0 | 5099 | { |
c0ff4b85 | 5100 | struct mem_cgroup *memcg = mem_cgroup_from_cont(cont); |
af36f906 | 5101 | char str[64]; |
104f3928 | 5102 | u64 val; |
86ae53e1 GC |
5103 | int name, len; |
5104 | enum res_type type; | |
8c7c6e34 KH |
5105 | |
5106 | type = MEMFILE_TYPE(cft->private); | |
5107 | name = MEMFILE_ATTR(cft->private); | |
af36f906 | 5108 | |
8c7c6e34 KH |
5109 | switch (type) { |
5110 | case _MEM: | |
104f3928 | 5111 | if (name == RES_USAGE) |
c0ff4b85 | 5112 | val = mem_cgroup_usage(memcg, false); |
104f3928 | 5113 | else |
c0ff4b85 | 5114 | val = res_counter_read_u64(&memcg->res, name); |
8c7c6e34 KH |
5115 | break; |
5116 | case _MEMSWAP: | |
104f3928 | 5117 | if (name == RES_USAGE) |
c0ff4b85 | 5118 | val = mem_cgroup_usage(memcg, true); |
104f3928 | 5119 | else |
c0ff4b85 | 5120 | val = res_counter_read_u64(&memcg->memsw, name); |
8c7c6e34 | 5121 | break; |
510fc4e1 GC |
5122 | case _KMEM: |
5123 | val = res_counter_read_u64(&memcg->kmem, name); | |
5124 | break; | |
8c7c6e34 KH |
5125 | default: |
5126 | BUG(); | |
8c7c6e34 | 5127 | } |
af36f906 TH |
5128 | |
5129 | len = scnprintf(str, sizeof(str), "%llu\n", (unsigned long long)val); | |
5130 | return simple_read_from_buffer(buf, nbytes, ppos, str, len); | |
8cdea7c0 | 5131 | } |
510fc4e1 GC |
5132 | |
5133 | static int memcg_update_kmem_limit(struct cgroup *cont, u64 val) | |
5134 | { | |
5135 | int ret = -EINVAL; | |
5136 | #ifdef CONFIG_MEMCG_KMEM | |
5137 | struct mem_cgroup *memcg = mem_cgroup_from_cont(cont); | |
5138 | /* | |
5139 | * For simplicity, we won't allow this to be disabled. It also can't | |
5140 | * be changed if the cgroup has children already, or if tasks had | |
5141 | * already joined. | |
5142 | * | |
5143 | * If tasks join before we set the limit, a person looking at | |
5144 | * kmem.usage_in_bytes will have no way to determine when it took | |
5145 | * place, which makes the value quite meaningless. | |
5146 | * | |
5147 | * After it first became limited, changes in the value of the limit are | |
5148 | * of course permitted. | |
510fc4e1 | 5149 | */ |
0999821b | 5150 | mutex_lock(&memcg_create_mutex); |
510fc4e1 GC |
5151 | mutex_lock(&set_limit_mutex); |
5152 | if (!memcg->kmem_account_flags && val != RESOURCE_MAX) { | |
b5f99b53 | 5153 | if (cgroup_task_count(cont) || memcg_has_children(memcg)) { |
510fc4e1 GC |
5154 | ret = -EBUSY; |
5155 | goto out; | |
5156 | } | |
5157 | ret = res_counter_set_limit(&memcg->kmem, val); | |
5158 | VM_BUG_ON(ret); | |
5159 | ||
55007d84 GC |
5160 | ret = memcg_update_cache_sizes(memcg); |
5161 | if (ret) { | |
5162 | res_counter_set_limit(&memcg->kmem, RESOURCE_MAX); | |
5163 | goto out; | |
5164 | } | |
692e89ab GC |
5165 | static_key_slow_inc(&memcg_kmem_enabled_key); |
5166 | /* | |
5167 | * setting the active bit after the inc will guarantee no one | |
5168 | * starts accounting before all call sites are patched | |
5169 | */ | |
5170 | memcg_kmem_set_active(memcg); | |
5171 | ||
7de37682 GC |
5172 | /* |
5173 | * kmem charges can outlive the cgroup. In the case of slab | |
5174 | * pages, for instance, a page contain objects from various | |
5175 | * processes, so it is unfeasible to migrate them away. We | |
5176 | * need to reference count the memcg because of that. | |
5177 | */ | |
5178 | mem_cgroup_get(memcg); | |
510fc4e1 GC |
5179 | } else |
5180 | ret = res_counter_set_limit(&memcg->kmem, val); | |
5181 | out: | |
5182 | mutex_unlock(&set_limit_mutex); | |
0999821b | 5183 | mutex_unlock(&memcg_create_mutex); |
510fc4e1 GC |
5184 | #endif |
5185 | return ret; | |
5186 | } | |
5187 | ||
6d043990 | 5188 | #ifdef CONFIG_MEMCG_KMEM |
55007d84 | 5189 | static int memcg_propagate_kmem(struct mem_cgroup *memcg) |
510fc4e1 | 5190 | { |
55007d84 | 5191 | int ret = 0; |
510fc4e1 GC |
5192 | struct mem_cgroup *parent = parent_mem_cgroup(memcg); |
5193 | if (!parent) | |
55007d84 GC |
5194 | goto out; |
5195 | ||
510fc4e1 | 5196 | memcg->kmem_account_flags = parent->kmem_account_flags; |
a8964b9b GC |
5197 | /* |
5198 | * When that happen, we need to disable the static branch only on those | |
5199 | * memcgs that enabled it. To achieve this, we would be forced to | |
5200 | * complicate the code by keeping track of which memcgs were the ones | |
5201 | * that actually enabled limits, and which ones got it from its | |
5202 | * parents. | |
5203 | * | |
5204 | * It is a lot simpler just to do static_key_slow_inc() on every child | |
5205 | * that is accounted. | |
5206 | */ | |
55007d84 GC |
5207 | if (!memcg_kmem_is_active(memcg)) |
5208 | goto out; | |
5209 | ||
5210 | /* | |
5211 | * destroy(), called if we fail, will issue static_key_slow_inc() and | |
5212 | * mem_cgroup_put() if kmem is enabled. We have to either call them | |
5213 | * unconditionally, or clear the KMEM_ACTIVE flag. I personally find | |
5214 | * this more consistent, since it always leads to the same destroy path | |
5215 | */ | |
5216 | mem_cgroup_get(memcg); | |
5217 | static_key_slow_inc(&memcg_kmem_enabled_key); | |
5218 | ||
5219 | mutex_lock(&set_limit_mutex); | |
5220 | ret = memcg_update_cache_sizes(memcg); | |
5221 | mutex_unlock(&set_limit_mutex); | |
55007d84 GC |
5222 | out: |
5223 | return ret; | |
510fc4e1 | 5224 | } |
6d043990 | 5225 | #endif /* CONFIG_MEMCG_KMEM */ |
510fc4e1 | 5226 | |
628f4235 KH |
5227 | /* |
5228 | * The user of this function is... | |
5229 | * RES_LIMIT. | |
5230 | */ | |
856c13aa PM |
5231 | static int mem_cgroup_write(struct cgroup *cont, struct cftype *cft, |
5232 | const char *buffer) | |
8cdea7c0 | 5233 | { |
628f4235 | 5234 | struct mem_cgroup *memcg = mem_cgroup_from_cont(cont); |
86ae53e1 GC |
5235 | enum res_type type; |
5236 | int name; | |
628f4235 KH |
5237 | unsigned long long val; |
5238 | int ret; | |
5239 | ||
8c7c6e34 KH |
5240 | type = MEMFILE_TYPE(cft->private); |
5241 | name = MEMFILE_ATTR(cft->private); | |
af36f906 | 5242 | |
8c7c6e34 | 5243 | switch (name) { |
628f4235 | 5244 | case RES_LIMIT: |
4b3bde4c BS |
5245 | if (mem_cgroup_is_root(memcg)) { /* Can't set limit on root */ |
5246 | ret = -EINVAL; | |
5247 | break; | |
5248 | } | |
628f4235 KH |
5249 | /* This function does all necessary parse...reuse it */ |
5250 | ret = res_counter_memparse_write_strategy(buffer, &val); | |
8c7c6e34 KH |
5251 | if (ret) |
5252 | break; | |
5253 | if (type == _MEM) | |
628f4235 | 5254 | ret = mem_cgroup_resize_limit(memcg, val); |
510fc4e1 | 5255 | else if (type == _MEMSWAP) |
8c7c6e34 | 5256 | ret = mem_cgroup_resize_memsw_limit(memcg, val); |
510fc4e1 GC |
5257 | else if (type == _KMEM) |
5258 | ret = memcg_update_kmem_limit(cont, val); | |
5259 | else | |
5260 | return -EINVAL; | |
628f4235 | 5261 | break; |
296c81d8 BS |
5262 | case RES_SOFT_LIMIT: |
5263 | ret = res_counter_memparse_write_strategy(buffer, &val); | |
5264 | if (ret) | |
5265 | break; | |
5266 | /* | |
5267 | * For memsw, soft limits are hard to implement in terms | |
5268 | * of semantics, for now, we support soft limits for | |
5269 | * control without swap | |
5270 | */ | |
5271 | if (type == _MEM) | |
5272 | ret = res_counter_set_soft_limit(&memcg->res, val); | |
5273 | else | |
5274 | ret = -EINVAL; | |
5275 | break; | |
628f4235 KH |
5276 | default: |
5277 | ret = -EINVAL; /* should be BUG() ? */ | |
5278 | break; | |
5279 | } | |
5280 | return ret; | |
8cdea7c0 BS |
5281 | } |
5282 | ||
fee7b548 KH |
5283 | static void memcg_get_hierarchical_limit(struct mem_cgroup *memcg, |
5284 | unsigned long long *mem_limit, unsigned long long *memsw_limit) | |
5285 | { | |
5286 | struct cgroup *cgroup; | |
5287 | unsigned long long min_limit, min_memsw_limit, tmp; | |
5288 | ||
5289 | min_limit = res_counter_read_u64(&memcg->res, RES_LIMIT); | |
5290 | min_memsw_limit = res_counter_read_u64(&memcg->memsw, RES_LIMIT); | |
5291 | cgroup = memcg->css.cgroup; | |
5292 | if (!memcg->use_hierarchy) | |
5293 | goto out; | |
5294 | ||
5295 | while (cgroup->parent) { | |
5296 | cgroup = cgroup->parent; | |
5297 | memcg = mem_cgroup_from_cont(cgroup); | |
5298 | if (!memcg->use_hierarchy) | |
5299 | break; | |
5300 | tmp = res_counter_read_u64(&memcg->res, RES_LIMIT); | |
5301 | min_limit = min(min_limit, tmp); | |
5302 | tmp = res_counter_read_u64(&memcg->memsw, RES_LIMIT); | |
5303 | min_memsw_limit = min(min_memsw_limit, tmp); | |
5304 | } | |
5305 | out: | |
5306 | *mem_limit = min_limit; | |
5307 | *memsw_limit = min_memsw_limit; | |
fee7b548 KH |
5308 | } |
5309 | ||
29f2a4da | 5310 | static int mem_cgroup_reset(struct cgroup *cont, unsigned int event) |
c84872e1 | 5311 | { |
af36f906 | 5312 | struct mem_cgroup *memcg = mem_cgroup_from_cont(cont); |
86ae53e1 GC |
5313 | int name; |
5314 | enum res_type type; | |
c84872e1 | 5315 | |
8c7c6e34 KH |
5316 | type = MEMFILE_TYPE(event); |
5317 | name = MEMFILE_ATTR(event); | |
af36f906 | 5318 | |
8c7c6e34 | 5319 | switch (name) { |
29f2a4da | 5320 | case RES_MAX_USAGE: |
8c7c6e34 | 5321 | if (type == _MEM) |
c0ff4b85 | 5322 | res_counter_reset_max(&memcg->res); |
510fc4e1 | 5323 | else if (type == _MEMSWAP) |
c0ff4b85 | 5324 | res_counter_reset_max(&memcg->memsw); |
510fc4e1 GC |
5325 | else if (type == _KMEM) |
5326 | res_counter_reset_max(&memcg->kmem); | |
5327 | else | |
5328 | return -EINVAL; | |
29f2a4da PE |
5329 | break; |
5330 | case RES_FAILCNT: | |
8c7c6e34 | 5331 | if (type == _MEM) |
c0ff4b85 | 5332 | res_counter_reset_failcnt(&memcg->res); |
510fc4e1 | 5333 | else if (type == _MEMSWAP) |
c0ff4b85 | 5334 | res_counter_reset_failcnt(&memcg->memsw); |
510fc4e1 GC |
5335 | else if (type == _KMEM) |
5336 | res_counter_reset_failcnt(&memcg->kmem); | |
5337 | else | |
5338 | return -EINVAL; | |
29f2a4da PE |
5339 | break; |
5340 | } | |
f64c3f54 | 5341 | |
85cc59db | 5342 | return 0; |
c84872e1 PE |
5343 | } |
5344 | ||
7dc74be0 DN |
5345 | static u64 mem_cgroup_move_charge_read(struct cgroup *cgrp, |
5346 | struct cftype *cft) | |
5347 | { | |
5348 | return mem_cgroup_from_cont(cgrp)->move_charge_at_immigrate; | |
5349 | } | |
5350 | ||
02491447 | 5351 | #ifdef CONFIG_MMU |
7dc74be0 DN |
5352 | static int mem_cgroup_move_charge_write(struct cgroup *cgrp, |
5353 | struct cftype *cft, u64 val) | |
5354 | { | |
c0ff4b85 | 5355 | struct mem_cgroup *memcg = mem_cgroup_from_cont(cgrp); |
7dc74be0 DN |
5356 | |
5357 | if (val >= (1 << NR_MOVE_TYPE)) | |
5358 | return -EINVAL; | |
ee5e8472 | 5359 | |
7dc74be0 | 5360 | /* |
ee5e8472 GC |
5361 | * No kind of locking is needed in here, because ->can_attach() will |
5362 | * check this value once in the beginning of the process, and then carry | |
5363 | * on with stale data. This means that changes to this value will only | |
5364 | * affect task migrations starting after the change. | |
7dc74be0 | 5365 | */ |
c0ff4b85 | 5366 | memcg->move_charge_at_immigrate = val; |
7dc74be0 DN |
5367 | return 0; |
5368 | } | |
02491447 DN |
5369 | #else |
5370 | static int mem_cgroup_move_charge_write(struct cgroup *cgrp, | |
5371 | struct cftype *cft, u64 val) | |
5372 | { | |
5373 | return -ENOSYS; | |
5374 | } | |
5375 | #endif | |
7dc74be0 | 5376 | |
406eb0c9 | 5377 | #ifdef CONFIG_NUMA |
ab215884 | 5378 | static int memcg_numa_stat_show(struct cgroup *cont, struct cftype *cft, |
fada52ca | 5379 | struct seq_file *m) |
406eb0c9 YH |
5380 | { |
5381 | int nid; | |
5382 | unsigned long total_nr, file_nr, anon_nr, unevictable_nr; | |
5383 | unsigned long node_nr; | |
d79154bb | 5384 | struct mem_cgroup *memcg = mem_cgroup_from_cont(cont); |
406eb0c9 | 5385 | |
d79154bb | 5386 | total_nr = mem_cgroup_nr_lru_pages(memcg, LRU_ALL); |
406eb0c9 | 5387 | seq_printf(m, "total=%lu", total_nr); |
31aaea4a | 5388 | for_each_node_state(nid, N_MEMORY) { |
d79154bb | 5389 | node_nr = mem_cgroup_node_nr_lru_pages(memcg, nid, LRU_ALL); |
406eb0c9 YH |
5390 | seq_printf(m, " N%d=%lu", nid, node_nr); |
5391 | } | |
5392 | seq_putc(m, '\n'); | |
5393 | ||
d79154bb | 5394 | file_nr = mem_cgroup_nr_lru_pages(memcg, LRU_ALL_FILE); |
406eb0c9 | 5395 | seq_printf(m, "file=%lu", file_nr); |
31aaea4a | 5396 | for_each_node_state(nid, N_MEMORY) { |
d79154bb | 5397 | node_nr = mem_cgroup_node_nr_lru_pages(memcg, nid, |
bb2a0de9 | 5398 | LRU_ALL_FILE); |
406eb0c9 YH |
5399 | seq_printf(m, " N%d=%lu", nid, node_nr); |
5400 | } | |
5401 | seq_putc(m, '\n'); | |
5402 | ||
d79154bb | 5403 | anon_nr = mem_cgroup_nr_lru_pages(memcg, LRU_ALL_ANON); |
406eb0c9 | 5404 | seq_printf(m, "anon=%lu", anon_nr); |
31aaea4a | 5405 | for_each_node_state(nid, N_MEMORY) { |
d79154bb | 5406 | node_nr = mem_cgroup_node_nr_lru_pages(memcg, nid, |
bb2a0de9 | 5407 | LRU_ALL_ANON); |
406eb0c9 YH |
5408 | seq_printf(m, " N%d=%lu", nid, node_nr); |
5409 | } | |
5410 | seq_putc(m, '\n'); | |
5411 | ||
d79154bb | 5412 | unevictable_nr = mem_cgroup_nr_lru_pages(memcg, BIT(LRU_UNEVICTABLE)); |
406eb0c9 | 5413 | seq_printf(m, "unevictable=%lu", unevictable_nr); |
31aaea4a | 5414 | for_each_node_state(nid, N_MEMORY) { |
d79154bb | 5415 | node_nr = mem_cgroup_node_nr_lru_pages(memcg, nid, |
bb2a0de9 | 5416 | BIT(LRU_UNEVICTABLE)); |
406eb0c9 YH |
5417 | seq_printf(m, " N%d=%lu", nid, node_nr); |
5418 | } | |
5419 | seq_putc(m, '\n'); | |
5420 | return 0; | |
5421 | } | |
5422 | #endif /* CONFIG_NUMA */ | |
5423 | ||
af7c4b0e JW |
5424 | static inline void mem_cgroup_lru_names_not_uptodate(void) |
5425 | { | |
5426 | BUILD_BUG_ON(ARRAY_SIZE(mem_cgroup_lru_names) != NR_LRU_LISTS); | |
5427 | } | |
5428 | ||
ab215884 | 5429 | static int memcg_stat_show(struct cgroup *cont, struct cftype *cft, |
78ccf5b5 | 5430 | struct seq_file *m) |
d2ceb9b7 | 5431 | { |
d79154bb | 5432 | struct mem_cgroup *memcg = mem_cgroup_from_cont(cont); |
af7c4b0e JW |
5433 | struct mem_cgroup *mi; |
5434 | unsigned int i; | |
406eb0c9 | 5435 | |
af7c4b0e | 5436 | for (i = 0; i < MEM_CGROUP_STAT_NSTATS; i++) { |
bff6bb83 | 5437 | if (i == MEM_CGROUP_STAT_SWAP && !do_swap_account) |
1dd3a273 | 5438 | continue; |
af7c4b0e JW |
5439 | seq_printf(m, "%s %ld\n", mem_cgroup_stat_names[i], |
5440 | mem_cgroup_read_stat(memcg, i) * PAGE_SIZE); | |
1dd3a273 | 5441 | } |
7b854121 | 5442 | |
af7c4b0e JW |
5443 | for (i = 0; i < MEM_CGROUP_EVENTS_NSTATS; i++) |
5444 | seq_printf(m, "%s %lu\n", mem_cgroup_events_names[i], | |
5445 | mem_cgroup_read_events(memcg, i)); | |
5446 | ||
5447 | for (i = 0; i < NR_LRU_LISTS; i++) | |
5448 | seq_printf(m, "%s %lu\n", mem_cgroup_lru_names[i], | |
5449 | mem_cgroup_nr_lru_pages(memcg, BIT(i)) * PAGE_SIZE); | |
5450 | ||
14067bb3 | 5451 | /* Hierarchical information */ |
fee7b548 KH |
5452 | { |
5453 | unsigned long long limit, memsw_limit; | |
d79154bb | 5454 | memcg_get_hierarchical_limit(memcg, &limit, &memsw_limit); |
78ccf5b5 | 5455 | seq_printf(m, "hierarchical_memory_limit %llu\n", limit); |
fee7b548 | 5456 | if (do_swap_account) |
78ccf5b5 JW |
5457 | seq_printf(m, "hierarchical_memsw_limit %llu\n", |
5458 | memsw_limit); | |
fee7b548 | 5459 | } |
7f016ee8 | 5460 | |
af7c4b0e JW |
5461 | for (i = 0; i < MEM_CGROUP_STAT_NSTATS; i++) { |
5462 | long long val = 0; | |
5463 | ||
bff6bb83 | 5464 | if (i == MEM_CGROUP_STAT_SWAP && !do_swap_account) |
1dd3a273 | 5465 | continue; |
af7c4b0e JW |
5466 | for_each_mem_cgroup_tree(mi, memcg) |
5467 | val += mem_cgroup_read_stat(mi, i) * PAGE_SIZE; | |
5468 | seq_printf(m, "total_%s %lld\n", mem_cgroup_stat_names[i], val); | |
5469 | } | |
5470 | ||
5471 | for (i = 0; i < MEM_CGROUP_EVENTS_NSTATS; i++) { | |
5472 | unsigned long long val = 0; | |
5473 | ||
5474 | for_each_mem_cgroup_tree(mi, memcg) | |
5475 | val += mem_cgroup_read_events(mi, i); | |
5476 | seq_printf(m, "total_%s %llu\n", | |
5477 | mem_cgroup_events_names[i], val); | |
5478 | } | |
5479 | ||
5480 | for (i = 0; i < NR_LRU_LISTS; i++) { | |
5481 | unsigned long long val = 0; | |
5482 | ||
5483 | for_each_mem_cgroup_tree(mi, memcg) | |
5484 | val += mem_cgroup_nr_lru_pages(mi, BIT(i)) * PAGE_SIZE; | |
5485 | seq_printf(m, "total_%s %llu\n", mem_cgroup_lru_names[i], val); | |
1dd3a273 | 5486 | } |
14067bb3 | 5487 | |
7f016ee8 | 5488 | #ifdef CONFIG_DEBUG_VM |
7f016ee8 KM |
5489 | { |
5490 | int nid, zid; | |
5491 | struct mem_cgroup_per_zone *mz; | |
89abfab1 | 5492 | struct zone_reclaim_stat *rstat; |
7f016ee8 KM |
5493 | unsigned long recent_rotated[2] = {0, 0}; |
5494 | unsigned long recent_scanned[2] = {0, 0}; | |
5495 | ||
5496 | for_each_online_node(nid) | |
5497 | for (zid = 0; zid < MAX_NR_ZONES; zid++) { | |
d79154bb | 5498 | mz = mem_cgroup_zoneinfo(memcg, nid, zid); |
89abfab1 | 5499 | rstat = &mz->lruvec.reclaim_stat; |
7f016ee8 | 5500 | |
89abfab1 HD |
5501 | recent_rotated[0] += rstat->recent_rotated[0]; |
5502 | recent_rotated[1] += rstat->recent_rotated[1]; | |
5503 | recent_scanned[0] += rstat->recent_scanned[0]; | |
5504 | recent_scanned[1] += rstat->recent_scanned[1]; | |
7f016ee8 | 5505 | } |
78ccf5b5 JW |
5506 | seq_printf(m, "recent_rotated_anon %lu\n", recent_rotated[0]); |
5507 | seq_printf(m, "recent_rotated_file %lu\n", recent_rotated[1]); | |
5508 | seq_printf(m, "recent_scanned_anon %lu\n", recent_scanned[0]); | |
5509 | seq_printf(m, "recent_scanned_file %lu\n", recent_scanned[1]); | |
7f016ee8 KM |
5510 | } |
5511 | #endif | |
5512 | ||
d2ceb9b7 KH |
5513 | return 0; |
5514 | } | |
5515 | ||
a7885eb8 KM |
5516 | static u64 mem_cgroup_swappiness_read(struct cgroup *cgrp, struct cftype *cft) |
5517 | { | |
5518 | struct mem_cgroup *memcg = mem_cgroup_from_cont(cgrp); | |
5519 | ||
1f4c025b | 5520 | return mem_cgroup_swappiness(memcg); |
a7885eb8 KM |
5521 | } |
5522 | ||
5523 | static int mem_cgroup_swappiness_write(struct cgroup *cgrp, struct cftype *cft, | |
5524 | u64 val) | |
5525 | { | |
5526 | struct mem_cgroup *memcg = mem_cgroup_from_cont(cgrp); | |
5527 | struct mem_cgroup *parent; | |
068b38c1 | 5528 | |
a7885eb8 KM |
5529 | if (val > 100) |
5530 | return -EINVAL; | |
5531 | ||
5532 | if (cgrp->parent == NULL) | |
5533 | return -EINVAL; | |
5534 | ||
5535 | parent = mem_cgroup_from_cont(cgrp->parent); | |
068b38c1 | 5536 | |
0999821b | 5537 | mutex_lock(&memcg_create_mutex); |
068b38c1 | 5538 | |
a7885eb8 | 5539 | /* If under hierarchy, only empty-root can set this value */ |
b5f99b53 | 5540 | if ((parent->use_hierarchy) || memcg_has_children(memcg)) { |
0999821b | 5541 | mutex_unlock(&memcg_create_mutex); |
a7885eb8 | 5542 | return -EINVAL; |
068b38c1 | 5543 | } |
a7885eb8 | 5544 | |
a7885eb8 | 5545 | memcg->swappiness = val; |
a7885eb8 | 5546 | |
0999821b | 5547 | mutex_unlock(&memcg_create_mutex); |
068b38c1 | 5548 | |
a7885eb8 KM |
5549 | return 0; |
5550 | } | |
5551 | ||
2e72b634 KS |
5552 | static void __mem_cgroup_threshold(struct mem_cgroup *memcg, bool swap) |
5553 | { | |
5554 | struct mem_cgroup_threshold_ary *t; | |
5555 | u64 usage; | |
5556 | int i; | |
5557 | ||
5558 | rcu_read_lock(); | |
5559 | if (!swap) | |
2c488db2 | 5560 | t = rcu_dereference(memcg->thresholds.primary); |
2e72b634 | 5561 | else |
2c488db2 | 5562 | t = rcu_dereference(memcg->memsw_thresholds.primary); |
2e72b634 KS |
5563 | |
5564 | if (!t) | |
5565 | goto unlock; | |
5566 | ||
5567 | usage = mem_cgroup_usage(memcg, swap); | |
5568 | ||
5569 | /* | |
748dad36 | 5570 | * current_threshold points to threshold just below or equal to usage. |
2e72b634 KS |
5571 | * If it's not true, a threshold was crossed after last |
5572 | * call of __mem_cgroup_threshold(). | |
5573 | */ | |
5407a562 | 5574 | i = t->current_threshold; |
2e72b634 KS |
5575 | |
5576 | /* | |
5577 | * Iterate backward over array of thresholds starting from | |
5578 | * current_threshold and check if a threshold is crossed. | |
5579 | * If none of thresholds below usage is crossed, we read | |
5580 | * only one element of the array here. | |
5581 | */ | |
5582 | for (; i >= 0 && unlikely(t->entries[i].threshold > usage); i--) | |
5583 | eventfd_signal(t->entries[i].eventfd, 1); | |
5584 | ||
5585 | /* i = current_threshold + 1 */ | |
5586 | i++; | |
5587 | ||
5588 | /* | |
5589 | * Iterate forward over array of thresholds starting from | |
5590 | * current_threshold+1 and check if a threshold is crossed. | |
5591 | * If none of thresholds above usage is crossed, we read | |
5592 | * only one element of the array here. | |
5593 | */ | |
5594 | for (; i < t->size && unlikely(t->entries[i].threshold <= usage); i++) | |
5595 | eventfd_signal(t->entries[i].eventfd, 1); | |
5596 | ||
5597 | /* Update current_threshold */ | |
5407a562 | 5598 | t->current_threshold = i - 1; |
2e72b634 KS |
5599 | unlock: |
5600 | rcu_read_unlock(); | |
5601 | } | |
5602 | ||
5603 | static void mem_cgroup_threshold(struct mem_cgroup *memcg) | |
5604 | { | |
ad4ca5f4 KS |
5605 | while (memcg) { |
5606 | __mem_cgroup_threshold(memcg, false); | |
5607 | if (do_swap_account) | |
5608 | __mem_cgroup_threshold(memcg, true); | |
5609 | ||
5610 | memcg = parent_mem_cgroup(memcg); | |
5611 | } | |
2e72b634 KS |
5612 | } |
5613 | ||
5614 | static int compare_thresholds(const void *a, const void *b) | |
5615 | { | |
5616 | const struct mem_cgroup_threshold *_a = a; | |
5617 | const struct mem_cgroup_threshold *_b = b; | |
5618 | ||
d96fa179 GT |
5619 | if (_a->threshold > _b->threshold) |
5620 | return 1; | |
5621 | ||
5622 | if (_a->threshold < _b->threshold) | |
5623 | return -1; | |
5624 | ||
5625 | return 0; | |
2e72b634 KS |
5626 | } |
5627 | ||
c0ff4b85 | 5628 | static int mem_cgroup_oom_notify_cb(struct mem_cgroup *memcg) |
9490ff27 KH |
5629 | { |
5630 | struct mem_cgroup_eventfd_list *ev; | |
5631 | ||
c0ff4b85 | 5632 | list_for_each_entry(ev, &memcg->oom_notify, list) |
9490ff27 KH |
5633 | eventfd_signal(ev->eventfd, 1); |
5634 | return 0; | |
5635 | } | |
5636 | ||
c0ff4b85 | 5637 | static void mem_cgroup_oom_notify(struct mem_cgroup *memcg) |
9490ff27 | 5638 | { |
7d74b06f KH |
5639 | struct mem_cgroup *iter; |
5640 | ||
c0ff4b85 | 5641 | for_each_mem_cgroup_tree(iter, memcg) |
7d74b06f | 5642 | mem_cgroup_oom_notify_cb(iter); |
9490ff27 KH |
5643 | } |
5644 | ||
5645 | static int mem_cgroup_usage_register_event(struct cgroup *cgrp, | |
5646 | struct cftype *cft, struct eventfd_ctx *eventfd, const char *args) | |
2e72b634 KS |
5647 | { |
5648 | struct mem_cgroup *memcg = mem_cgroup_from_cont(cgrp); | |
2c488db2 KS |
5649 | struct mem_cgroup_thresholds *thresholds; |
5650 | struct mem_cgroup_threshold_ary *new; | |
86ae53e1 | 5651 | enum res_type type = MEMFILE_TYPE(cft->private); |
2e72b634 | 5652 | u64 threshold, usage; |
2c488db2 | 5653 | int i, size, ret; |
2e72b634 KS |
5654 | |
5655 | ret = res_counter_memparse_write_strategy(args, &threshold); | |
5656 | if (ret) | |
5657 | return ret; | |
5658 | ||
5659 | mutex_lock(&memcg->thresholds_lock); | |
2c488db2 | 5660 | |
2e72b634 | 5661 | if (type == _MEM) |
2c488db2 | 5662 | thresholds = &memcg->thresholds; |
2e72b634 | 5663 | else if (type == _MEMSWAP) |
2c488db2 | 5664 | thresholds = &memcg->memsw_thresholds; |
2e72b634 KS |
5665 | else |
5666 | BUG(); | |
5667 | ||
5668 | usage = mem_cgroup_usage(memcg, type == _MEMSWAP); | |
5669 | ||
5670 | /* Check if a threshold crossed before adding a new one */ | |
2c488db2 | 5671 | if (thresholds->primary) |
2e72b634 KS |
5672 | __mem_cgroup_threshold(memcg, type == _MEMSWAP); |
5673 | ||
2c488db2 | 5674 | size = thresholds->primary ? thresholds->primary->size + 1 : 1; |
2e72b634 KS |
5675 | |
5676 | /* Allocate memory for new array of thresholds */ | |
2c488db2 | 5677 | new = kmalloc(sizeof(*new) + size * sizeof(struct mem_cgroup_threshold), |
2e72b634 | 5678 | GFP_KERNEL); |
2c488db2 | 5679 | if (!new) { |
2e72b634 KS |
5680 | ret = -ENOMEM; |
5681 | goto unlock; | |
5682 | } | |
2c488db2 | 5683 | new->size = size; |
2e72b634 KS |
5684 | |
5685 | /* Copy thresholds (if any) to new array */ | |
2c488db2 KS |
5686 | if (thresholds->primary) { |
5687 | memcpy(new->entries, thresholds->primary->entries, (size - 1) * | |
2e72b634 | 5688 | sizeof(struct mem_cgroup_threshold)); |
2c488db2 KS |
5689 | } |
5690 | ||
2e72b634 | 5691 | /* Add new threshold */ |
2c488db2 KS |
5692 | new->entries[size - 1].eventfd = eventfd; |
5693 | new->entries[size - 1].threshold = threshold; | |
2e72b634 KS |
5694 | |
5695 | /* Sort thresholds. Registering of new threshold isn't time-critical */ | |
2c488db2 | 5696 | sort(new->entries, size, sizeof(struct mem_cgroup_threshold), |
2e72b634 KS |
5697 | compare_thresholds, NULL); |
5698 | ||
5699 | /* Find current threshold */ | |
2c488db2 | 5700 | new->current_threshold = -1; |
2e72b634 | 5701 | for (i = 0; i < size; i++) { |
748dad36 | 5702 | if (new->entries[i].threshold <= usage) { |
2e72b634 | 5703 | /* |
2c488db2 KS |
5704 | * new->current_threshold will not be used until |
5705 | * rcu_assign_pointer(), so it's safe to increment | |
2e72b634 KS |
5706 | * it here. |
5707 | */ | |
2c488db2 | 5708 | ++new->current_threshold; |
748dad36 SZ |
5709 | } else |
5710 | break; | |
2e72b634 KS |
5711 | } |
5712 | ||
2c488db2 KS |
5713 | /* Free old spare buffer and save old primary buffer as spare */ |
5714 | kfree(thresholds->spare); | |
5715 | thresholds->spare = thresholds->primary; | |
5716 | ||
5717 | rcu_assign_pointer(thresholds->primary, new); | |
2e72b634 | 5718 | |
907860ed | 5719 | /* To be sure that nobody uses thresholds */ |
2e72b634 KS |
5720 | synchronize_rcu(); |
5721 | ||
2e72b634 KS |
5722 | unlock: |
5723 | mutex_unlock(&memcg->thresholds_lock); | |
5724 | ||
5725 | return ret; | |
5726 | } | |
5727 | ||
907860ed | 5728 | static void mem_cgroup_usage_unregister_event(struct cgroup *cgrp, |
9490ff27 | 5729 | struct cftype *cft, struct eventfd_ctx *eventfd) |
2e72b634 KS |
5730 | { |
5731 | struct mem_cgroup *memcg = mem_cgroup_from_cont(cgrp); | |
2c488db2 KS |
5732 | struct mem_cgroup_thresholds *thresholds; |
5733 | struct mem_cgroup_threshold_ary *new; | |
86ae53e1 | 5734 | enum res_type type = MEMFILE_TYPE(cft->private); |
2e72b634 | 5735 | u64 usage; |
2c488db2 | 5736 | int i, j, size; |
2e72b634 KS |
5737 | |
5738 | mutex_lock(&memcg->thresholds_lock); | |
5739 | if (type == _MEM) | |
2c488db2 | 5740 | thresholds = &memcg->thresholds; |
2e72b634 | 5741 | else if (type == _MEMSWAP) |
2c488db2 | 5742 | thresholds = &memcg->memsw_thresholds; |
2e72b634 KS |
5743 | else |
5744 | BUG(); | |
5745 | ||
371528ca AV |
5746 | if (!thresholds->primary) |
5747 | goto unlock; | |
5748 | ||
2e72b634 KS |
5749 | usage = mem_cgroup_usage(memcg, type == _MEMSWAP); |
5750 | ||
5751 | /* Check if a threshold crossed before removing */ | |
5752 | __mem_cgroup_threshold(memcg, type == _MEMSWAP); | |
5753 | ||
5754 | /* Calculate new number of threshold */ | |
2c488db2 KS |
5755 | size = 0; |
5756 | for (i = 0; i < thresholds->primary->size; i++) { | |
5757 | if (thresholds->primary->entries[i].eventfd != eventfd) | |
2e72b634 KS |
5758 | size++; |
5759 | } | |
5760 | ||
2c488db2 | 5761 | new = thresholds->spare; |
907860ed | 5762 | |
2e72b634 KS |
5763 | /* Set thresholds array to NULL if we don't have thresholds */ |
5764 | if (!size) { | |
2c488db2 KS |
5765 | kfree(new); |
5766 | new = NULL; | |
907860ed | 5767 | goto swap_buffers; |
2e72b634 KS |
5768 | } |
5769 | ||
2c488db2 | 5770 | new->size = size; |
2e72b634 KS |
5771 | |
5772 | /* Copy thresholds and find current threshold */ | |
2c488db2 KS |
5773 | new->current_threshold = -1; |
5774 | for (i = 0, j = 0; i < thresholds->primary->size; i++) { | |
5775 | if (thresholds->primary->entries[i].eventfd == eventfd) | |
2e72b634 KS |
5776 | continue; |
5777 | ||
2c488db2 | 5778 | new->entries[j] = thresholds->primary->entries[i]; |
748dad36 | 5779 | if (new->entries[j].threshold <= usage) { |
2e72b634 | 5780 | /* |
2c488db2 | 5781 | * new->current_threshold will not be used |
2e72b634 KS |
5782 | * until rcu_assign_pointer(), so it's safe to increment |
5783 | * it here. | |
5784 | */ | |
2c488db2 | 5785 | ++new->current_threshold; |
2e72b634 KS |
5786 | } |
5787 | j++; | |
5788 | } | |
5789 | ||
907860ed | 5790 | swap_buffers: |
2c488db2 KS |
5791 | /* Swap primary and spare array */ |
5792 | thresholds->spare = thresholds->primary; | |
8c757763 | 5793 | |
2c488db2 | 5794 | rcu_assign_pointer(thresholds->primary, new); |
2e72b634 | 5795 | |
907860ed | 5796 | /* To be sure that nobody uses thresholds */ |
2e72b634 | 5797 | synchronize_rcu(); |
a28c4bb3 MC |
5798 | |
5799 | /* If all events are unregistered, free the spare array */ | |
5800 | if (!new) { | |
5801 | kfree(thresholds->spare); | |
5802 | thresholds->spare = NULL; | |
5803 | } | |
371528ca | 5804 | unlock: |
2e72b634 | 5805 | mutex_unlock(&memcg->thresholds_lock); |
2e72b634 | 5806 | } |
c1e862c1 | 5807 | |
9490ff27 KH |
5808 | static int mem_cgroup_oom_register_event(struct cgroup *cgrp, |
5809 | struct cftype *cft, struct eventfd_ctx *eventfd, const char *args) | |
5810 | { | |
5811 | struct mem_cgroup *memcg = mem_cgroup_from_cont(cgrp); | |
5812 | struct mem_cgroup_eventfd_list *event; | |
86ae53e1 | 5813 | enum res_type type = MEMFILE_TYPE(cft->private); |
9490ff27 KH |
5814 | |
5815 | BUG_ON(type != _OOM_TYPE); | |
5816 | event = kmalloc(sizeof(*event), GFP_KERNEL); | |
5817 | if (!event) | |
5818 | return -ENOMEM; | |
5819 | ||
1af8efe9 | 5820 | spin_lock(&memcg_oom_lock); |
9490ff27 KH |
5821 | |
5822 | event->eventfd = eventfd; | |
5823 | list_add(&event->list, &memcg->oom_notify); | |
5824 | ||
5825 | /* already in OOM ? */ | |
79dfdacc | 5826 | if (atomic_read(&memcg->under_oom)) |
9490ff27 | 5827 | eventfd_signal(eventfd, 1); |
1af8efe9 | 5828 | spin_unlock(&memcg_oom_lock); |
9490ff27 KH |
5829 | |
5830 | return 0; | |
5831 | } | |
5832 | ||
907860ed | 5833 | static void mem_cgroup_oom_unregister_event(struct cgroup *cgrp, |
9490ff27 KH |
5834 | struct cftype *cft, struct eventfd_ctx *eventfd) |
5835 | { | |
c0ff4b85 | 5836 | struct mem_cgroup *memcg = mem_cgroup_from_cont(cgrp); |
9490ff27 | 5837 | struct mem_cgroup_eventfd_list *ev, *tmp; |
86ae53e1 | 5838 | enum res_type type = MEMFILE_TYPE(cft->private); |
9490ff27 KH |
5839 | |
5840 | BUG_ON(type != _OOM_TYPE); | |
5841 | ||
1af8efe9 | 5842 | spin_lock(&memcg_oom_lock); |
9490ff27 | 5843 | |
c0ff4b85 | 5844 | list_for_each_entry_safe(ev, tmp, &memcg->oom_notify, list) { |
9490ff27 KH |
5845 | if (ev->eventfd == eventfd) { |
5846 | list_del(&ev->list); | |
5847 | kfree(ev); | |
5848 | } | |
5849 | } | |
5850 | ||
1af8efe9 | 5851 | spin_unlock(&memcg_oom_lock); |
9490ff27 KH |
5852 | } |
5853 | ||
3c11ecf4 KH |
5854 | static int mem_cgroup_oom_control_read(struct cgroup *cgrp, |
5855 | struct cftype *cft, struct cgroup_map_cb *cb) | |
5856 | { | |
c0ff4b85 | 5857 | struct mem_cgroup *memcg = mem_cgroup_from_cont(cgrp); |
3c11ecf4 | 5858 | |
c0ff4b85 | 5859 | cb->fill(cb, "oom_kill_disable", memcg->oom_kill_disable); |
3c11ecf4 | 5860 | |
c0ff4b85 | 5861 | if (atomic_read(&memcg->under_oom)) |
3c11ecf4 KH |
5862 | cb->fill(cb, "under_oom", 1); |
5863 | else | |
5864 | cb->fill(cb, "under_oom", 0); | |
5865 | return 0; | |
5866 | } | |
5867 | ||
3c11ecf4 KH |
5868 | static int mem_cgroup_oom_control_write(struct cgroup *cgrp, |
5869 | struct cftype *cft, u64 val) | |
5870 | { | |
c0ff4b85 | 5871 | struct mem_cgroup *memcg = mem_cgroup_from_cont(cgrp); |
3c11ecf4 KH |
5872 | struct mem_cgroup *parent; |
5873 | ||
5874 | /* cannot set to root cgroup and only 0 and 1 are allowed */ | |
5875 | if (!cgrp->parent || !((val == 0) || (val == 1))) | |
5876 | return -EINVAL; | |
5877 | ||
5878 | parent = mem_cgroup_from_cont(cgrp->parent); | |
5879 | ||
0999821b | 5880 | mutex_lock(&memcg_create_mutex); |
3c11ecf4 | 5881 | /* oom-kill-disable is a flag for subhierarchy. */ |
b5f99b53 | 5882 | if ((parent->use_hierarchy) || memcg_has_children(memcg)) { |
0999821b | 5883 | mutex_unlock(&memcg_create_mutex); |
3c11ecf4 KH |
5884 | return -EINVAL; |
5885 | } | |
c0ff4b85 | 5886 | memcg->oom_kill_disable = val; |
4d845ebf | 5887 | if (!val) |
c0ff4b85 | 5888 | memcg_oom_recover(memcg); |
0999821b | 5889 | mutex_unlock(&memcg_create_mutex); |
3c11ecf4 KH |
5890 | return 0; |
5891 | } | |
5892 | ||
c255a458 | 5893 | #ifdef CONFIG_MEMCG_KMEM |
cbe128e3 | 5894 | static int memcg_init_kmem(struct mem_cgroup *memcg, struct cgroup_subsys *ss) |
e5671dfa | 5895 | { |
55007d84 GC |
5896 | int ret; |
5897 | ||
2633d7a0 | 5898 | memcg->kmemcg_id = -1; |
55007d84 GC |
5899 | ret = memcg_propagate_kmem(memcg); |
5900 | if (ret) | |
5901 | return ret; | |
2633d7a0 | 5902 | |
1d62e436 | 5903 | return mem_cgroup_sockets_init(memcg, ss); |
573b400d | 5904 | } |
e5671dfa | 5905 | |
1d62e436 | 5906 | static void kmem_cgroup_destroy(struct mem_cgroup *memcg) |
d1a4c0b3 | 5907 | { |
1d62e436 | 5908 | mem_cgroup_sockets_destroy(memcg); |
7de37682 GC |
5909 | |
5910 | memcg_kmem_mark_dead(memcg); | |
5911 | ||
5912 | if (res_counter_read_u64(&memcg->kmem, RES_USAGE) != 0) | |
5913 | return; | |
5914 | ||
5915 | /* | |
5916 | * Charges already down to 0, undo mem_cgroup_get() done in the charge | |
5917 | * path here, being careful not to race with memcg_uncharge_kmem: it is | |
5918 | * possible that the charges went down to 0 between mark_dead and the | |
5919 | * res_counter read, so in that case, we don't need the put | |
5920 | */ | |
5921 | if (memcg_kmem_test_and_clear_dead(memcg)) | |
5922 | mem_cgroup_put(memcg); | |
d1a4c0b3 | 5923 | } |
e5671dfa | 5924 | #else |
cbe128e3 | 5925 | static int memcg_init_kmem(struct mem_cgroup *memcg, struct cgroup_subsys *ss) |
e5671dfa GC |
5926 | { |
5927 | return 0; | |
5928 | } | |
d1a4c0b3 | 5929 | |
1d62e436 | 5930 | static void kmem_cgroup_destroy(struct mem_cgroup *memcg) |
d1a4c0b3 GC |
5931 | { |
5932 | } | |
e5671dfa GC |
5933 | #endif |
5934 | ||
8cdea7c0 BS |
5935 | static struct cftype mem_cgroup_files[] = { |
5936 | { | |
0eea1030 | 5937 | .name = "usage_in_bytes", |
8c7c6e34 | 5938 | .private = MEMFILE_PRIVATE(_MEM, RES_USAGE), |
af36f906 | 5939 | .read = mem_cgroup_read, |
9490ff27 KH |
5940 | .register_event = mem_cgroup_usage_register_event, |
5941 | .unregister_event = mem_cgroup_usage_unregister_event, | |
8cdea7c0 | 5942 | }, |
c84872e1 PE |
5943 | { |
5944 | .name = "max_usage_in_bytes", | |
8c7c6e34 | 5945 | .private = MEMFILE_PRIVATE(_MEM, RES_MAX_USAGE), |
29f2a4da | 5946 | .trigger = mem_cgroup_reset, |
af36f906 | 5947 | .read = mem_cgroup_read, |
c84872e1 | 5948 | }, |
8cdea7c0 | 5949 | { |
0eea1030 | 5950 | .name = "limit_in_bytes", |
8c7c6e34 | 5951 | .private = MEMFILE_PRIVATE(_MEM, RES_LIMIT), |
856c13aa | 5952 | .write_string = mem_cgroup_write, |
af36f906 | 5953 | .read = mem_cgroup_read, |
8cdea7c0 | 5954 | }, |
296c81d8 BS |
5955 | { |
5956 | .name = "soft_limit_in_bytes", | |
5957 | .private = MEMFILE_PRIVATE(_MEM, RES_SOFT_LIMIT), | |
5958 | .write_string = mem_cgroup_write, | |
af36f906 | 5959 | .read = mem_cgroup_read, |
296c81d8 | 5960 | }, |
8cdea7c0 BS |
5961 | { |
5962 | .name = "failcnt", | |
8c7c6e34 | 5963 | .private = MEMFILE_PRIVATE(_MEM, RES_FAILCNT), |
29f2a4da | 5964 | .trigger = mem_cgroup_reset, |
af36f906 | 5965 | .read = mem_cgroup_read, |
8cdea7c0 | 5966 | }, |
d2ceb9b7 KH |
5967 | { |
5968 | .name = "stat", | |
ab215884 | 5969 | .read_seq_string = memcg_stat_show, |
d2ceb9b7 | 5970 | }, |
c1e862c1 KH |
5971 | { |
5972 | .name = "force_empty", | |
5973 | .trigger = mem_cgroup_force_empty_write, | |
5974 | }, | |
18f59ea7 BS |
5975 | { |
5976 | .name = "use_hierarchy", | |
f00baae7 | 5977 | .flags = CFTYPE_INSANE, |
18f59ea7 BS |
5978 | .write_u64 = mem_cgroup_hierarchy_write, |
5979 | .read_u64 = mem_cgroup_hierarchy_read, | |
5980 | }, | |
a7885eb8 KM |
5981 | { |
5982 | .name = "swappiness", | |
5983 | .read_u64 = mem_cgroup_swappiness_read, | |
5984 | .write_u64 = mem_cgroup_swappiness_write, | |
5985 | }, | |
7dc74be0 DN |
5986 | { |
5987 | .name = "move_charge_at_immigrate", | |
5988 | .read_u64 = mem_cgroup_move_charge_read, | |
5989 | .write_u64 = mem_cgroup_move_charge_write, | |
5990 | }, | |
9490ff27 KH |
5991 | { |
5992 | .name = "oom_control", | |
3c11ecf4 KH |
5993 | .read_map = mem_cgroup_oom_control_read, |
5994 | .write_u64 = mem_cgroup_oom_control_write, | |
9490ff27 KH |
5995 | .register_event = mem_cgroup_oom_register_event, |
5996 | .unregister_event = mem_cgroup_oom_unregister_event, | |
5997 | .private = MEMFILE_PRIVATE(_OOM_TYPE, OOM_CONTROL), | |
5998 | }, | |
70ddf637 AV |
5999 | { |
6000 | .name = "pressure_level", | |
6001 | .register_event = vmpressure_register_event, | |
6002 | .unregister_event = vmpressure_unregister_event, | |
6003 | }, | |
406eb0c9 YH |
6004 | #ifdef CONFIG_NUMA |
6005 | { | |
6006 | .name = "numa_stat", | |
ab215884 | 6007 | .read_seq_string = memcg_numa_stat_show, |
406eb0c9 YH |
6008 | }, |
6009 | #endif | |
510fc4e1 GC |
6010 | #ifdef CONFIG_MEMCG_KMEM |
6011 | { | |
6012 | .name = "kmem.limit_in_bytes", | |
6013 | .private = MEMFILE_PRIVATE(_KMEM, RES_LIMIT), | |
6014 | .write_string = mem_cgroup_write, | |
6015 | .read = mem_cgroup_read, | |
6016 | }, | |
6017 | { | |
6018 | .name = "kmem.usage_in_bytes", | |
6019 | .private = MEMFILE_PRIVATE(_KMEM, RES_USAGE), | |
6020 | .read = mem_cgroup_read, | |
6021 | }, | |
6022 | { | |
6023 | .name = "kmem.failcnt", | |
6024 | .private = MEMFILE_PRIVATE(_KMEM, RES_FAILCNT), | |
6025 | .trigger = mem_cgroup_reset, | |
6026 | .read = mem_cgroup_read, | |
6027 | }, | |
6028 | { | |
6029 | .name = "kmem.max_usage_in_bytes", | |
6030 | .private = MEMFILE_PRIVATE(_KMEM, RES_MAX_USAGE), | |
6031 | .trigger = mem_cgroup_reset, | |
6032 | .read = mem_cgroup_read, | |
6033 | }, | |
749c5415 GC |
6034 | #ifdef CONFIG_SLABINFO |
6035 | { | |
6036 | .name = "kmem.slabinfo", | |
6037 | .read_seq_string = mem_cgroup_slabinfo_read, | |
6038 | }, | |
6039 | #endif | |
8c7c6e34 | 6040 | #endif |
6bc10349 | 6041 | { }, /* terminate */ |
af36f906 | 6042 | }; |
8c7c6e34 | 6043 | |
2d11085e MH |
6044 | #ifdef CONFIG_MEMCG_SWAP |
6045 | static struct cftype memsw_cgroup_files[] = { | |
6046 | { | |
6047 | .name = "memsw.usage_in_bytes", | |
6048 | .private = MEMFILE_PRIVATE(_MEMSWAP, RES_USAGE), | |
6049 | .read = mem_cgroup_read, | |
6050 | .register_event = mem_cgroup_usage_register_event, | |
6051 | .unregister_event = mem_cgroup_usage_unregister_event, | |
6052 | }, | |
6053 | { | |
6054 | .name = "memsw.max_usage_in_bytes", | |
6055 | .private = MEMFILE_PRIVATE(_MEMSWAP, RES_MAX_USAGE), | |
6056 | .trigger = mem_cgroup_reset, | |
6057 | .read = mem_cgroup_read, | |
6058 | }, | |
6059 | { | |
6060 | .name = "memsw.limit_in_bytes", | |
6061 | .private = MEMFILE_PRIVATE(_MEMSWAP, RES_LIMIT), | |
6062 | .write_string = mem_cgroup_write, | |
6063 | .read = mem_cgroup_read, | |
6064 | }, | |
6065 | { | |
6066 | .name = "memsw.failcnt", | |
6067 | .private = MEMFILE_PRIVATE(_MEMSWAP, RES_FAILCNT), | |
6068 | .trigger = mem_cgroup_reset, | |
6069 | .read = mem_cgroup_read, | |
6070 | }, | |
6071 | { }, /* terminate */ | |
6072 | }; | |
6073 | #endif | |
c0ff4b85 | 6074 | static int alloc_mem_cgroup_per_zone_info(struct mem_cgroup *memcg, int node) |
6d12e2d8 KH |
6075 | { |
6076 | struct mem_cgroup_per_node *pn; | |
1ecaab2b | 6077 | struct mem_cgroup_per_zone *mz; |
41e3355d | 6078 | int zone, tmp = node; |
1ecaab2b KH |
6079 | /* |
6080 | * This routine is called against possible nodes. | |
6081 | * But it's BUG to call kmalloc() against offline node. | |
6082 | * | |
6083 | * TODO: this routine can waste much memory for nodes which will | |
6084 | * never be onlined. It's better to use memory hotplug callback | |
6085 | * function. | |
6086 | */ | |
41e3355d KH |
6087 | if (!node_state(node, N_NORMAL_MEMORY)) |
6088 | tmp = -1; | |
17295c88 | 6089 | pn = kzalloc_node(sizeof(*pn), GFP_KERNEL, tmp); |
6d12e2d8 KH |
6090 | if (!pn) |
6091 | return 1; | |
1ecaab2b | 6092 | |
1ecaab2b KH |
6093 | for (zone = 0; zone < MAX_NR_ZONES; zone++) { |
6094 | mz = &pn->zoneinfo[zone]; | |
bea8c150 | 6095 | lruvec_init(&mz->lruvec); |
f64c3f54 | 6096 | mz->usage_in_excess = 0; |
4e416953 | 6097 | mz->on_tree = false; |
d79154bb | 6098 | mz->memcg = memcg; |
1ecaab2b | 6099 | } |
0a619e58 | 6100 | memcg->info.nodeinfo[node] = pn; |
6d12e2d8 KH |
6101 | return 0; |
6102 | } | |
6103 | ||
c0ff4b85 | 6104 | static void free_mem_cgroup_per_zone_info(struct mem_cgroup *memcg, int node) |
1ecaab2b | 6105 | { |
c0ff4b85 | 6106 | kfree(memcg->info.nodeinfo[node]); |
1ecaab2b KH |
6107 | } |
6108 | ||
33327948 KH |
6109 | static struct mem_cgroup *mem_cgroup_alloc(void) |
6110 | { | |
d79154bb | 6111 | struct mem_cgroup *memcg; |
45cf7ebd | 6112 | size_t size = memcg_size(); |
33327948 | 6113 | |
45cf7ebd | 6114 | /* Can be very big if nr_node_ids is very big */ |
c8dad2bb | 6115 | if (size < PAGE_SIZE) |
d79154bb | 6116 | memcg = kzalloc(size, GFP_KERNEL); |
33327948 | 6117 | else |
d79154bb | 6118 | memcg = vzalloc(size); |
33327948 | 6119 | |
d79154bb | 6120 | if (!memcg) |
e7bbcdf3 DC |
6121 | return NULL; |
6122 | ||
d79154bb HD |
6123 | memcg->stat = alloc_percpu(struct mem_cgroup_stat_cpu); |
6124 | if (!memcg->stat) | |
d2e61b8d | 6125 | goto out_free; |
d79154bb HD |
6126 | spin_lock_init(&memcg->pcp_counter_lock); |
6127 | return memcg; | |
d2e61b8d DC |
6128 | |
6129 | out_free: | |
6130 | if (size < PAGE_SIZE) | |
d79154bb | 6131 | kfree(memcg); |
d2e61b8d | 6132 | else |
d79154bb | 6133 | vfree(memcg); |
d2e61b8d | 6134 | return NULL; |
33327948 KH |
6135 | } |
6136 | ||
59927fb9 | 6137 | /* |
c8b2a36f GC |
6138 | * At destroying mem_cgroup, references from swap_cgroup can remain. |
6139 | * (scanning all at force_empty is too costly...) | |
6140 | * | |
6141 | * Instead of clearing all references at force_empty, we remember | |
6142 | * the number of reference from swap_cgroup and free mem_cgroup when | |
6143 | * it goes down to 0. | |
6144 | * | |
6145 | * Removal of cgroup itself succeeds regardless of refs from swap. | |
59927fb9 | 6146 | */ |
c8b2a36f GC |
6147 | |
6148 | static void __mem_cgroup_free(struct mem_cgroup *memcg) | |
59927fb9 | 6149 | { |
c8b2a36f | 6150 | int node; |
45cf7ebd | 6151 | size_t size = memcg_size(); |
59927fb9 | 6152 | |
c8b2a36f GC |
6153 | mem_cgroup_remove_from_trees(memcg); |
6154 | free_css_id(&mem_cgroup_subsys, &memcg->css); | |
6155 | ||
6156 | for_each_node(node) | |
6157 | free_mem_cgroup_per_zone_info(memcg, node); | |
6158 | ||
6159 | free_percpu(memcg->stat); | |
6160 | ||
3f134619 GC |
6161 | /* |
6162 | * We need to make sure that (at least for now), the jump label | |
6163 | * destruction code runs outside of the cgroup lock. This is because | |
6164 | * get_online_cpus(), which is called from the static_branch update, | |
6165 | * can't be called inside the cgroup_lock. cpusets are the ones | |
6166 | * enforcing this dependency, so if they ever change, we might as well. | |
6167 | * | |
6168 | * schedule_work() will guarantee this happens. Be careful if you need | |
6169 | * to move this code around, and make sure it is outside | |
6170 | * the cgroup_lock. | |
6171 | */ | |
a8964b9b | 6172 | disarm_static_keys(memcg); |
3afe36b1 GC |
6173 | if (size < PAGE_SIZE) |
6174 | kfree(memcg); | |
6175 | else | |
6176 | vfree(memcg); | |
59927fb9 | 6177 | } |
3afe36b1 | 6178 | |
59927fb9 | 6179 | |
8c7c6e34 | 6180 | /* |
c8b2a36f GC |
6181 | * Helpers for freeing a kmalloc()ed/vzalloc()ed mem_cgroup by RCU, |
6182 | * but in process context. The work_freeing structure is overlaid | |
6183 | * on the rcu_freeing structure, which itself is overlaid on memsw. | |
8c7c6e34 | 6184 | */ |
c8b2a36f | 6185 | static void free_work(struct work_struct *work) |
33327948 | 6186 | { |
c8b2a36f | 6187 | struct mem_cgroup *memcg; |
08e552c6 | 6188 | |
c8b2a36f GC |
6189 | memcg = container_of(work, struct mem_cgroup, work_freeing); |
6190 | __mem_cgroup_free(memcg); | |
6191 | } | |
04046e1a | 6192 | |
c8b2a36f GC |
6193 | static void free_rcu(struct rcu_head *rcu_head) |
6194 | { | |
6195 | struct mem_cgroup *memcg; | |
08e552c6 | 6196 | |
c8b2a36f GC |
6197 | memcg = container_of(rcu_head, struct mem_cgroup, rcu_freeing); |
6198 | INIT_WORK(&memcg->work_freeing, free_work); | |
6199 | schedule_work(&memcg->work_freeing); | |
33327948 KH |
6200 | } |
6201 | ||
c0ff4b85 | 6202 | static void mem_cgroup_get(struct mem_cgroup *memcg) |
8c7c6e34 | 6203 | { |
c0ff4b85 | 6204 | atomic_inc(&memcg->refcnt); |
8c7c6e34 KH |
6205 | } |
6206 | ||
c0ff4b85 | 6207 | static void __mem_cgroup_put(struct mem_cgroup *memcg, int count) |
8c7c6e34 | 6208 | { |
c0ff4b85 R |
6209 | if (atomic_sub_and_test(count, &memcg->refcnt)) { |
6210 | struct mem_cgroup *parent = parent_mem_cgroup(memcg); | |
c8b2a36f | 6211 | call_rcu(&memcg->rcu_freeing, free_rcu); |
7bcc1bb1 DN |
6212 | if (parent) |
6213 | mem_cgroup_put(parent); | |
6214 | } | |
8c7c6e34 KH |
6215 | } |
6216 | ||
c0ff4b85 | 6217 | static void mem_cgroup_put(struct mem_cgroup *memcg) |
483c30b5 | 6218 | { |
c0ff4b85 | 6219 | __mem_cgroup_put(memcg, 1); |
483c30b5 DN |
6220 | } |
6221 | ||
7bcc1bb1 DN |
6222 | /* |
6223 | * Returns the parent mem_cgroup in memcgroup hierarchy with hierarchy enabled. | |
6224 | */ | |
e1aab161 | 6225 | struct mem_cgroup *parent_mem_cgroup(struct mem_cgroup *memcg) |
7bcc1bb1 | 6226 | { |
c0ff4b85 | 6227 | if (!memcg->res.parent) |
7bcc1bb1 | 6228 | return NULL; |
c0ff4b85 | 6229 | return mem_cgroup_from_res_counter(memcg->res.parent, res); |
7bcc1bb1 | 6230 | } |
e1aab161 | 6231 | EXPORT_SYMBOL(parent_mem_cgroup); |
33327948 | 6232 | |
8787a1df | 6233 | static void __init mem_cgroup_soft_limit_tree_init(void) |
f64c3f54 BS |
6234 | { |
6235 | struct mem_cgroup_tree_per_node *rtpn; | |
6236 | struct mem_cgroup_tree_per_zone *rtpz; | |
6237 | int tmp, node, zone; | |
6238 | ||
3ed28fa1 | 6239 | for_each_node(node) { |
f64c3f54 BS |
6240 | tmp = node; |
6241 | if (!node_state(node, N_NORMAL_MEMORY)) | |
6242 | tmp = -1; | |
6243 | rtpn = kzalloc_node(sizeof(*rtpn), GFP_KERNEL, tmp); | |
8787a1df | 6244 | BUG_ON(!rtpn); |
f64c3f54 BS |
6245 | |
6246 | soft_limit_tree.rb_tree_per_node[node] = rtpn; | |
6247 | ||
6248 | for (zone = 0; zone < MAX_NR_ZONES; zone++) { | |
6249 | rtpz = &rtpn->rb_tree_per_zone[zone]; | |
6250 | rtpz->rb_root = RB_ROOT; | |
6251 | spin_lock_init(&rtpz->lock); | |
6252 | } | |
6253 | } | |
f64c3f54 BS |
6254 | } |
6255 | ||
0eb253e2 | 6256 | static struct cgroup_subsys_state * __ref |
92fb9748 | 6257 | mem_cgroup_css_alloc(struct cgroup *cont) |
8cdea7c0 | 6258 | { |
d142e3e6 | 6259 | struct mem_cgroup *memcg; |
04046e1a | 6260 | long error = -ENOMEM; |
6d12e2d8 | 6261 | int node; |
8cdea7c0 | 6262 | |
c0ff4b85 R |
6263 | memcg = mem_cgroup_alloc(); |
6264 | if (!memcg) | |
04046e1a | 6265 | return ERR_PTR(error); |
78fb7466 | 6266 | |
3ed28fa1 | 6267 | for_each_node(node) |
c0ff4b85 | 6268 | if (alloc_mem_cgroup_per_zone_info(memcg, node)) |
6d12e2d8 | 6269 | goto free_out; |
f64c3f54 | 6270 | |
c077719b | 6271 | /* root ? */ |
28dbc4b6 | 6272 | if (cont->parent == NULL) { |
a41c58a6 | 6273 | root_mem_cgroup = memcg; |
d142e3e6 GC |
6274 | res_counter_init(&memcg->res, NULL); |
6275 | res_counter_init(&memcg->memsw, NULL); | |
6276 | res_counter_init(&memcg->kmem, NULL); | |
18f59ea7 | 6277 | } |
28dbc4b6 | 6278 | |
d142e3e6 GC |
6279 | memcg->last_scanned_node = MAX_NUMNODES; |
6280 | INIT_LIST_HEAD(&memcg->oom_notify); | |
6281 | atomic_set(&memcg->refcnt, 1); | |
6282 | memcg->move_charge_at_immigrate = 0; | |
6283 | mutex_init(&memcg->thresholds_lock); | |
6284 | spin_lock_init(&memcg->move_lock); | |
70ddf637 | 6285 | vmpressure_init(&memcg->vmpressure); |
d142e3e6 GC |
6286 | |
6287 | return &memcg->css; | |
6288 | ||
6289 | free_out: | |
6290 | __mem_cgroup_free(memcg); | |
6291 | return ERR_PTR(error); | |
6292 | } | |
6293 | ||
6294 | static int | |
6295 | mem_cgroup_css_online(struct cgroup *cont) | |
6296 | { | |
6297 | struct mem_cgroup *memcg, *parent; | |
6298 | int error = 0; | |
6299 | ||
6300 | if (!cont->parent) | |
6301 | return 0; | |
6302 | ||
0999821b | 6303 | mutex_lock(&memcg_create_mutex); |
d142e3e6 GC |
6304 | memcg = mem_cgroup_from_cont(cont); |
6305 | parent = mem_cgroup_from_cont(cont->parent); | |
6306 | ||
6307 | memcg->use_hierarchy = parent->use_hierarchy; | |
6308 | memcg->oom_kill_disable = parent->oom_kill_disable; | |
6309 | memcg->swappiness = mem_cgroup_swappiness(parent); | |
6310 | ||
6311 | if (parent->use_hierarchy) { | |
c0ff4b85 R |
6312 | res_counter_init(&memcg->res, &parent->res); |
6313 | res_counter_init(&memcg->memsw, &parent->memsw); | |
510fc4e1 | 6314 | res_counter_init(&memcg->kmem, &parent->kmem); |
55007d84 | 6315 | |
7bcc1bb1 DN |
6316 | /* |
6317 | * We increment refcnt of the parent to ensure that we can | |
6318 | * safely access it on res_counter_charge/uncharge. | |
6319 | * This refcnt will be decremented when freeing this | |
6320 | * mem_cgroup(see mem_cgroup_put). | |
6321 | */ | |
6322 | mem_cgroup_get(parent); | |
18f59ea7 | 6323 | } else { |
c0ff4b85 R |
6324 | res_counter_init(&memcg->res, NULL); |
6325 | res_counter_init(&memcg->memsw, NULL); | |
510fc4e1 | 6326 | res_counter_init(&memcg->kmem, NULL); |
8c7f6edb TH |
6327 | /* |
6328 | * Deeper hierachy with use_hierarchy == false doesn't make | |
6329 | * much sense so let cgroup subsystem know about this | |
6330 | * unfortunate state in our controller. | |
6331 | */ | |
d142e3e6 | 6332 | if (parent != root_mem_cgroup) |
8c7f6edb | 6333 | mem_cgroup_subsys.broken_hierarchy = true; |
18f59ea7 | 6334 | } |
cbe128e3 GC |
6335 | |
6336 | error = memcg_init_kmem(memcg, &mem_cgroup_subsys); | |
0999821b | 6337 | mutex_unlock(&memcg_create_mutex); |
d142e3e6 | 6338 | return error; |
8cdea7c0 BS |
6339 | } |
6340 | ||
5f578161 MH |
6341 | /* |
6342 | * Announce all parents that a group from their hierarchy is gone. | |
6343 | */ | |
6344 | static void mem_cgroup_invalidate_reclaim_iterators(struct mem_cgroup *memcg) | |
6345 | { | |
6346 | struct mem_cgroup *parent = memcg; | |
6347 | ||
6348 | while ((parent = parent_mem_cgroup(parent))) | |
6349 | atomic_inc(&parent->dead_count); | |
6350 | ||
6351 | /* | |
6352 | * if the root memcg is not hierarchical we have to check it | |
6353 | * explicitely. | |
6354 | */ | |
6355 | if (!root_mem_cgroup->use_hierarchy) | |
6356 | atomic_inc(&root_mem_cgroup->dead_count); | |
6357 | } | |
6358 | ||
92fb9748 | 6359 | static void mem_cgroup_css_offline(struct cgroup *cont) |
df878fb0 | 6360 | { |
c0ff4b85 | 6361 | struct mem_cgroup *memcg = mem_cgroup_from_cont(cont); |
ba9a7297 | 6362 | struct cgroup *iter; |
ec64f515 | 6363 | |
5f578161 | 6364 | mem_cgroup_invalidate_reclaim_iterators(memcg); |
ba9a7297 FB |
6365 | |
6366 | /* | |
6367 | * This requires that offlining is serialized. Right now that is | |
6368 | * guaranteed because css_killed_work_fn() holds the cgroup_mutex. | |
6369 | */ | |
6370 | rcu_read_lock(); | |
6371 | cgroup_for_each_descendant_post(iter, cont) { | |
6372 | rcu_read_unlock(); | |
6373 | mem_cgroup_reparent_charges(mem_cgroup_from_cont(iter)); | |
6374 | rcu_read_lock(); | |
6375 | } | |
6376 | rcu_read_unlock(); | |
ab5196c2 | 6377 | mem_cgroup_reparent_charges(memcg); |
ba9a7297 | 6378 | |
1f458cbf | 6379 | mem_cgroup_destroy_all_caches(memcg); |
df878fb0 KH |
6380 | } |
6381 | ||
92fb9748 | 6382 | static void mem_cgroup_css_free(struct cgroup *cont) |
8cdea7c0 | 6383 | { |
c0ff4b85 | 6384 | struct mem_cgroup *memcg = mem_cgroup_from_cont(cont); |
c268e994 | 6385 | |
1d62e436 | 6386 | kmem_cgroup_destroy(memcg); |
d1a4c0b3 | 6387 | |
c0ff4b85 | 6388 | mem_cgroup_put(memcg); |
8cdea7c0 BS |
6389 | } |
6390 | ||
02491447 | 6391 | #ifdef CONFIG_MMU |
7dc74be0 | 6392 | /* Handlers for move charge at task migration. */ |
854ffa8d DN |
6393 | #define PRECHARGE_COUNT_AT_ONCE 256 |
6394 | static int mem_cgroup_do_precharge(unsigned long count) | |
7dc74be0 | 6395 | { |
854ffa8d DN |
6396 | int ret = 0; |
6397 | int batch_count = PRECHARGE_COUNT_AT_ONCE; | |
c0ff4b85 | 6398 | struct mem_cgroup *memcg = mc.to; |
4ffef5fe | 6399 | |
c0ff4b85 | 6400 | if (mem_cgroup_is_root(memcg)) { |
854ffa8d DN |
6401 | mc.precharge += count; |
6402 | /* we don't need css_get for root */ | |
6403 | return ret; | |
6404 | } | |
6405 | /* try to charge at once */ | |
6406 | if (count > 1) { | |
6407 | struct res_counter *dummy; | |
6408 | /* | |
c0ff4b85 | 6409 | * "memcg" cannot be under rmdir() because we've already checked |
854ffa8d DN |
6410 | * by cgroup_lock_live_cgroup() that it is not removed and we |
6411 | * are still under the same cgroup_mutex. So we can postpone | |
6412 | * css_get(). | |
6413 | */ | |
c0ff4b85 | 6414 | if (res_counter_charge(&memcg->res, PAGE_SIZE * count, &dummy)) |
854ffa8d | 6415 | goto one_by_one; |
c0ff4b85 | 6416 | if (do_swap_account && res_counter_charge(&memcg->memsw, |
854ffa8d | 6417 | PAGE_SIZE * count, &dummy)) { |
c0ff4b85 | 6418 | res_counter_uncharge(&memcg->res, PAGE_SIZE * count); |
854ffa8d DN |
6419 | goto one_by_one; |
6420 | } | |
6421 | mc.precharge += count; | |
854ffa8d DN |
6422 | return ret; |
6423 | } | |
6424 | one_by_one: | |
6425 | /* fall back to one by one charge */ | |
6426 | while (count--) { | |
6427 | if (signal_pending(current)) { | |
6428 | ret = -EINTR; | |
6429 | break; | |
6430 | } | |
6431 | if (!batch_count--) { | |
6432 | batch_count = PRECHARGE_COUNT_AT_ONCE; | |
6433 | cond_resched(); | |
6434 | } | |
c0ff4b85 R |
6435 | ret = __mem_cgroup_try_charge(NULL, |
6436 | GFP_KERNEL, 1, &memcg, false); | |
38c5d72f | 6437 | if (ret) |
854ffa8d | 6438 | /* mem_cgroup_clear_mc() will do uncharge later */ |
38c5d72f | 6439 | return ret; |
854ffa8d DN |
6440 | mc.precharge++; |
6441 | } | |
4ffef5fe DN |
6442 | return ret; |
6443 | } | |
6444 | ||
6445 | /** | |
8d32ff84 | 6446 | * get_mctgt_type - get target type of moving charge |
4ffef5fe DN |
6447 | * @vma: the vma the pte to be checked belongs |
6448 | * @addr: the address corresponding to the pte to be checked | |
6449 | * @ptent: the pte to be checked | |
02491447 | 6450 | * @target: the pointer the target page or swap ent will be stored(can be NULL) |
4ffef5fe DN |
6451 | * |
6452 | * Returns | |
6453 | * 0(MC_TARGET_NONE): if the pte is not a target for move charge. | |
6454 | * 1(MC_TARGET_PAGE): if the page corresponding to this pte is a target for | |
6455 | * move charge. if @target is not NULL, the page is stored in target->page | |
6456 | * with extra refcnt got(Callers should handle it). | |
02491447 DN |
6457 | * 2(MC_TARGET_SWAP): if the swap entry corresponding to this pte is a |
6458 | * target for charge migration. if @target is not NULL, the entry is stored | |
6459 | * in target->ent. | |
4ffef5fe DN |
6460 | * |
6461 | * Called with pte lock held. | |
6462 | */ | |
4ffef5fe DN |
6463 | union mc_target { |
6464 | struct page *page; | |
02491447 | 6465 | swp_entry_t ent; |
4ffef5fe DN |
6466 | }; |
6467 | ||
4ffef5fe | 6468 | enum mc_target_type { |
8d32ff84 | 6469 | MC_TARGET_NONE = 0, |
4ffef5fe | 6470 | MC_TARGET_PAGE, |
02491447 | 6471 | MC_TARGET_SWAP, |
4ffef5fe DN |
6472 | }; |
6473 | ||
90254a65 DN |
6474 | static struct page *mc_handle_present_pte(struct vm_area_struct *vma, |
6475 | unsigned long addr, pte_t ptent) | |
4ffef5fe | 6476 | { |
90254a65 | 6477 | struct page *page = vm_normal_page(vma, addr, ptent); |
4ffef5fe | 6478 | |
90254a65 DN |
6479 | if (!page || !page_mapped(page)) |
6480 | return NULL; | |
6481 | if (PageAnon(page)) { | |
6482 | /* we don't move shared anon */ | |
4b91355e | 6483 | if (!move_anon()) |
90254a65 | 6484 | return NULL; |
87946a72 DN |
6485 | } else if (!move_file()) |
6486 | /* we ignore mapcount for file pages */ | |
90254a65 DN |
6487 | return NULL; |
6488 | if (!get_page_unless_zero(page)) | |
6489 | return NULL; | |
6490 | ||
6491 | return page; | |
6492 | } | |
6493 | ||
4b91355e | 6494 | #ifdef CONFIG_SWAP |
90254a65 DN |
6495 | static struct page *mc_handle_swap_pte(struct vm_area_struct *vma, |
6496 | unsigned long addr, pte_t ptent, swp_entry_t *entry) | |
6497 | { | |
90254a65 DN |
6498 | struct page *page = NULL; |
6499 | swp_entry_t ent = pte_to_swp_entry(ptent); | |
6500 | ||
6501 | if (!move_anon() || non_swap_entry(ent)) | |
6502 | return NULL; | |
4b91355e KH |
6503 | /* |
6504 | * Because lookup_swap_cache() updates some statistics counter, | |
6505 | * we call find_get_page() with swapper_space directly. | |
6506 | */ | |
33806f06 | 6507 | page = find_get_page(swap_address_space(ent), ent.val); |
90254a65 DN |
6508 | if (do_swap_account) |
6509 | entry->val = ent.val; | |
6510 | ||
6511 | return page; | |
6512 | } | |
4b91355e KH |
6513 | #else |
6514 | static struct page *mc_handle_swap_pte(struct vm_area_struct *vma, | |
6515 | unsigned long addr, pte_t ptent, swp_entry_t *entry) | |
6516 | { | |
6517 | return NULL; | |
6518 | } | |
6519 | #endif | |
90254a65 | 6520 | |
87946a72 DN |
6521 | static struct page *mc_handle_file_pte(struct vm_area_struct *vma, |
6522 | unsigned long addr, pte_t ptent, swp_entry_t *entry) | |
6523 | { | |
6524 | struct page *page = NULL; | |
87946a72 DN |
6525 | struct address_space *mapping; |
6526 | pgoff_t pgoff; | |
6527 | ||
6528 | if (!vma->vm_file) /* anonymous vma */ | |
6529 | return NULL; | |
6530 | if (!move_file()) | |
6531 | return NULL; | |
6532 | ||
87946a72 DN |
6533 | mapping = vma->vm_file->f_mapping; |
6534 | if (pte_none(ptent)) | |
6535 | pgoff = linear_page_index(vma, addr); | |
6536 | else /* pte_file(ptent) is true */ | |
6537 | pgoff = pte_to_pgoff(ptent); | |
6538 | ||
6539 | /* page is moved even if it's not RSS of this task(page-faulted). */ | |
aa3b1895 HD |
6540 | page = find_get_page(mapping, pgoff); |
6541 | ||
6542 | #ifdef CONFIG_SWAP | |
6543 | /* shmem/tmpfs may report page out on swap: account for that too. */ | |
6544 | if (radix_tree_exceptional_entry(page)) { | |
6545 | swp_entry_t swap = radix_to_swp_entry(page); | |
87946a72 | 6546 | if (do_swap_account) |
aa3b1895 | 6547 | *entry = swap; |
33806f06 | 6548 | page = find_get_page(swap_address_space(swap), swap.val); |
87946a72 | 6549 | } |
aa3b1895 | 6550 | #endif |
87946a72 DN |
6551 | return page; |
6552 | } | |
6553 | ||
8d32ff84 | 6554 | static enum mc_target_type get_mctgt_type(struct vm_area_struct *vma, |
90254a65 DN |
6555 | unsigned long addr, pte_t ptent, union mc_target *target) |
6556 | { | |
6557 | struct page *page = NULL; | |
6558 | struct page_cgroup *pc; | |
8d32ff84 | 6559 | enum mc_target_type ret = MC_TARGET_NONE; |
90254a65 DN |
6560 | swp_entry_t ent = { .val = 0 }; |
6561 | ||
6562 | if (pte_present(ptent)) | |
6563 | page = mc_handle_present_pte(vma, addr, ptent); | |
6564 | else if (is_swap_pte(ptent)) | |
6565 | page = mc_handle_swap_pte(vma, addr, ptent, &ent); | |
87946a72 DN |
6566 | else if (pte_none(ptent) || pte_file(ptent)) |
6567 | page = mc_handle_file_pte(vma, addr, ptent, &ent); | |
90254a65 DN |
6568 | |
6569 | if (!page && !ent.val) | |
8d32ff84 | 6570 | return ret; |
02491447 DN |
6571 | if (page) { |
6572 | pc = lookup_page_cgroup(page); | |
6573 | /* | |
6574 | * Do only loose check w/o page_cgroup lock. | |
6575 | * mem_cgroup_move_account() checks the pc is valid or not under | |
6576 | * the lock. | |
6577 | */ | |
6578 | if (PageCgroupUsed(pc) && pc->mem_cgroup == mc.from) { | |
6579 | ret = MC_TARGET_PAGE; | |
6580 | if (target) | |
6581 | target->page = page; | |
6582 | } | |
6583 | if (!ret || !target) | |
6584 | put_page(page); | |
6585 | } | |
90254a65 DN |
6586 | /* There is a swap entry and a page doesn't exist or isn't charged */ |
6587 | if (ent.val && !ret && | |
9fb4b7cc | 6588 | css_id(&mc.from->css) == lookup_swap_cgroup_id(ent)) { |
7f0f1546 KH |
6589 | ret = MC_TARGET_SWAP; |
6590 | if (target) | |
6591 | target->ent = ent; | |
4ffef5fe | 6592 | } |
4ffef5fe DN |
6593 | return ret; |
6594 | } | |
6595 | ||
12724850 NH |
6596 | #ifdef CONFIG_TRANSPARENT_HUGEPAGE |
6597 | /* | |
6598 | * We don't consider swapping or file mapped pages because THP does not | |
6599 | * support them for now. | |
6600 | * Caller should make sure that pmd_trans_huge(pmd) is true. | |
6601 | */ | |
6602 | static enum mc_target_type get_mctgt_type_thp(struct vm_area_struct *vma, | |
6603 | unsigned long addr, pmd_t pmd, union mc_target *target) | |
6604 | { | |
6605 | struct page *page = NULL; | |
6606 | struct page_cgroup *pc; | |
6607 | enum mc_target_type ret = MC_TARGET_NONE; | |
6608 | ||
6609 | page = pmd_page(pmd); | |
6610 | VM_BUG_ON(!page || !PageHead(page)); | |
6611 | if (!move_anon()) | |
6612 | return ret; | |
6613 | pc = lookup_page_cgroup(page); | |
6614 | if (PageCgroupUsed(pc) && pc->mem_cgroup == mc.from) { | |
6615 | ret = MC_TARGET_PAGE; | |
6616 | if (target) { | |
6617 | get_page(page); | |
6618 | target->page = page; | |
6619 | } | |
6620 | } | |
6621 | return ret; | |
6622 | } | |
6623 | #else | |
6624 | static inline enum mc_target_type get_mctgt_type_thp(struct vm_area_struct *vma, | |
6625 | unsigned long addr, pmd_t pmd, union mc_target *target) | |
6626 | { | |
6627 | return MC_TARGET_NONE; | |
6628 | } | |
6629 | #endif | |
6630 | ||
4ffef5fe DN |
6631 | static int mem_cgroup_count_precharge_pte_range(pmd_t *pmd, |
6632 | unsigned long addr, unsigned long end, | |
6633 | struct mm_walk *walk) | |
6634 | { | |
6635 | struct vm_area_struct *vma = walk->private; | |
6636 | pte_t *pte; | |
6637 | spinlock_t *ptl; | |
6638 | ||
12724850 NH |
6639 | if (pmd_trans_huge_lock(pmd, vma) == 1) { |
6640 | if (get_mctgt_type_thp(vma, addr, *pmd, NULL) == MC_TARGET_PAGE) | |
6641 | mc.precharge += HPAGE_PMD_NR; | |
6642 | spin_unlock(&vma->vm_mm->page_table_lock); | |
1a5a9906 | 6643 | return 0; |
12724850 | 6644 | } |
03319327 | 6645 | |
45f83cef AA |
6646 | if (pmd_trans_unstable(pmd)) |
6647 | return 0; | |
4ffef5fe DN |
6648 | pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl); |
6649 | for (; addr != end; pte++, addr += PAGE_SIZE) | |
8d32ff84 | 6650 | if (get_mctgt_type(vma, addr, *pte, NULL)) |
4ffef5fe DN |
6651 | mc.precharge++; /* increment precharge temporarily */ |
6652 | pte_unmap_unlock(pte - 1, ptl); | |
6653 | cond_resched(); | |
6654 | ||
7dc74be0 DN |
6655 | return 0; |
6656 | } | |
6657 | ||
4ffef5fe DN |
6658 | static unsigned long mem_cgroup_count_precharge(struct mm_struct *mm) |
6659 | { | |
6660 | unsigned long precharge; | |
6661 | struct vm_area_struct *vma; | |
6662 | ||
dfe076b0 | 6663 | down_read(&mm->mmap_sem); |
4ffef5fe DN |
6664 | for (vma = mm->mmap; vma; vma = vma->vm_next) { |
6665 | struct mm_walk mem_cgroup_count_precharge_walk = { | |
6666 | .pmd_entry = mem_cgroup_count_precharge_pte_range, | |
6667 | .mm = mm, | |
6668 | .private = vma, | |
6669 | }; | |
6670 | if (is_vm_hugetlb_page(vma)) | |
6671 | continue; | |
4ffef5fe DN |
6672 | walk_page_range(vma->vm_start, vma->vm_end, |
6673 | &mem_cgroup_count_precharge_walk); | |
6674 | } | |
dfe076b0 | 6675 | up_read(&mm->mmap_sem); |
4ffef5fe DN |
6676 | |
6677 | precharge = mc.precharge; | |
6678 | mc.precharge = 0; | |
6679 | ||
6680 | return precharge; | |
6681 | } | |
6682 | ||
4ffef5fe DN |
6683 | static int mem_cgroup_precharge_mc(struct mm_struct *mm) |
6684 | { | |
dfe076b0 DN |
6685 | unsigned long precharge = mem_cgroup_count_precharge(mm); |
6686 | ||
6687 | VM_BUG_ON(mc.moving_task); | |
6688 | mc.moving_task = current; | |
6689 | return mem_cgroup_do_precharge(precharge); | |
4ffef5fe DN |
6690 | } |
6691 | ||
dfe076b0 DN |
6692 | /* cancels all extra charges on mc.from and mc.to, and wakes up all waiters. */ |
6693 | static void __mem_cgroup_clear_mc(void) | |
4ffef5fe | 6694 | { |
2bd9bb20 KH |
6695 | struct mem_cgroup *from = mc.from; |
6696 | struct mem_cgroup *to = mc.to; | |
6697 | ||
4ffef5fe | 6698 | /* we must uncharge all the leftover precharges from mc.to */ |
854ffa8d DN |
6699 | if (mc.precharge) { |
6700 | __mem_cgroup_cancel_charge(mc.to, mc.precharge); | |
6701 | mc.precharge = 0; | |
6702 | } | |
6703 | /* | |
6704 | * we didn't uncharge from mc.from at mem_cgroup_move_account(), so | |
6705 | * we must uncharge here. | |
6706 | */ | |
6707 | if (mc.moved_charge) { | |
6708 | __mem_cgroup_cancel_charge(mc.from, mc.moved_charge); | |
6709 | mc.moved_charge = 0; | |
4ffef5fe | 6710 | } |
483c30b5 DN |
6711 | /* we must fixup refcnts and charges */ |
6712 | if (mc.moved_swap) { | |
483c30b5 DN |
6713 | /* uncharge swap account from the old cgroup */ |
6714 | if (!mem_cgroup_is_root(mc.from)) | |
6715 | res_counter_uncharge(&mc.from->memsw, | |
6716 | PAGE_SIZE * mc.moved_swap); | |
6717 | __mem_cgroup_put(mc.from, mc.moved_swap); | |
6718 | ||
6719 | if (!mem_cgroup_is_root(mc.to)) { | |
6720 | /* | |
6721 | * we charged both to->res and to->memsw, so we should | |
6722 | * uncharge to->res. | |
6723 | */ | |
6724 | res_counter_uncharge(&mc.to->res, | |
6725 | PAGE_SIZE * mc.moved_swap); | |
483c30b5 DN |
6726 | } |
6727 | /* we've already done mem_cgroup_get(mc.to) */ | |
483c30b5 DN |
6728 | mc.moved_swap = 0; |
6729 | } | |
dfe076b0 DN |
6730 | memcg_oom_recover(from); |
6731 | memcg_oom_recover(to); | |
6732 | wake_up_all(&mc.waitq); | |
6733 | } | |
6734 | ||
6735 | static void mem_cgroup_clear_mc(void) | |
6736 | { | |
6737 | struct mem_cgroup *from = mc.from; | |
6738 | ||
6739 | /* | |
6740 | * we must clear moving_task before waking up waiters at the end of | |
6741 | * task migration. | |
6742 | */ | |
6743 | mc.moving_task = NULL; | |
6744 | __mem_cgroup_clear_mc(); | |
2bd9bb20 | 6745 | spin_lock(&mc.lock); |
4ffef5fe DN |
6746 | mc.from = NULL; |
6747 | mc.to = NULL; | |
2bd9bb20 | 6748 | spin_unlock(&mc.lock); |
32047e2a | 6749 | mem_cgroup_end_move(from); |
4ffef5fe DN |
6750 | } |
6751 | ||
761b3ef5 LZ |
6752 | static int mem_cgroup_can_attach(struct cgroup *cgroup, |
6753 | struct cgroup_taskset *tset) | |
7dc74be0 | 6754 | { |
2f7ee569 | 6755 | struct task_struct *p = cgroup_taskset_first(tset); |
7dc74be0 | 6756 | int ret = 0; |
c0ff4b85 | 6757 | struct mem_cgroup *memcg = mem_cgroup_from_cont(cgroup); |
ee5e8472 | 6758 | unsigned long move_charge_at_immigrate; |
7dc74be0 | 6759 | |
ee5e8472 GC |
6760 | /* |
6761 | * We are now commited to this value whatever it is. Changes in this | |
6762 | * tunable will only affect upcoming migrations, not the current one. | |
6763 | * So we need to save it, and keep it going. | |
6764 | */ | |
6765 | move_charge_at_immigrate = memcg->move_charge_at_immigrate; | |
6766 | if (move_charge_at_immigrate) { | |
7dc74be0 DN |
6767 | struct mm_struct *mm; |
6768 | struct mem_cgroup *from = mem_cgroup_from_task(p); | |
6769 | ||
c0ff4b85 | 6770 | VM_BUG_ON(from == memcg); |
7dc74be0 DN |
6771 | |
6772 | mm = get_task_mm(p); | |
6773 | if (!mm) | |
6774 | return 0; | |
7dc74be0 | 6775 | /* We move charges only when we move a owner of the mm */ |
4ffef5fe DN |
6776 | if (mm->owner == p) { |
6777 | VM_BUG_ON(mc.from); | |
6778 | VM_BUG_ON(mc.to); | |
6779 | VM_BUG_ON(mc.precharge); | |
854ffa8d | 6780 | VM_BUG_ON(mc.moved_charge); |
483c30b5 | 6781 | VM_BUG_ON(mc.moved_swap); |
32047e2a | 6782 | mem_cgroup_start_move(from); |
2bd9bb20 | 6783 | spin_lock(&mc.lock); |
4ffef5fe | 6784 | mc.from = from; |
c0ff4b85 | 6785 | mc.to = memcg; |
ee5e8472 | 6786 | mc.immigrate_flags = move_charge_at_immigrate; |
2bd9bb20 | 6787 | spin_unlock(&mc.lock); |
dfe076b0 | 6788 | /* We set mc.moving_task later */ |
4ffef5fe DN |
6789 | |
6790 | ret = mem_cgroup_precharge_mc(mm); | |
6791 | if (ret) | |
6792 | mem_cgroup_clear_mc(); | |
dfe076b0 DN |
6793 | } |
6794 | mmput(mm); | |
7dc74be0 DN |
6795 | } |
6796 | return ret; | |
6797 | } | |
6798 | ||
761b3ef5 LZ |
6799 | static void mem_cgroup_cancel_attach(struct cgroup *cgroup, |
6800 | struct cgroup_taskset *tset) | |
7dc74be0 | 6801 | { |
4ffef5fe | 6802 | mem_cgroup_clear_mc(); |
7dc74be0 DN |
6803 | } |
6804 | ||
4ffef5fe DN |
6805 | static int mem_cgroup_move_charge_pte_range(pmd_t *pmd, |
6806 | unsigned long addr, unsigned long end, | |
6807 | struct mm_walk *walk) | |
7dc74be0 | 6808 | { |
4ffef5fe DN |
6809 | int ret = 0; |
6810 | struct vm_area_struct *vma = walk->private; | |
6811 | pte_t *pte; | |
6812 | spinlock_t *ptl; | |
12724850 NH |
6813 | enum mc_target_type target_type; |
6814 | union mc_target target; | |
6815 | struct page *page; | |
6816 | struct page_cgroup *pc; | |
4ffef5fe | 6817 | |
12724850 NH |
6818 | /* |
6819 | * We don't take compound_lock() here but no race with splitting thp | |
6820 | * happens because: | |
6821 | * - if pmd_trans_huge_lock() returns 1, the relevant thp is not | |
6822 | * under splitting, which means there's no concurrent thp split, | |
6823 | * - if another thread runs into split_huge_page() just after we | |
6824 | * entered this if-block, the thread must wait for page table lock | |
6825 | * to be unlocked in __split_huge_page_splitting(), where the main | |
6826 | * part of thp split is not executed yet. | |
6827 | */ | |
6828 | if (pmd_trans_huge_lock(pmd, vma) == 1) { | |
62ade86a | 6829 | if (mc.precharge < HPAGE_PMD_NR) { |
12724850 NH |
6830 | spin_unlock(&vma->vm_mm->page_table_lock); |
6831 | return 0; | |
6832 | } | |
6833 | target_type = get_mctgt_type_thp(vma, addr, *pmd, &target); | |
6834 | if (target_type == MC_TARGET_PAGE) { | |
6835 | page = target.page; | |
6836 | if (!isolate_lru_page(page)) { | |
6837 | pc = lookup_page_cgroup(page); | |
6838 | if (!mem_cgroup_move_account(page, HPAGE_PMD_NR, | |
2f3479b1 | 6839 | pc, mc.from, mc.to)) { |
12724850 NH |
6840 | mc.precharge -= HPAGE_PMD_NR; |
6841 | mc.moved_charge += HPAGE_PMD_NR; | |
6842 | } | |
6843 | putback_lru_page(page); | |
6844 | } | |
6845 | put_page(page); | |
6846 | } | |
6847 | spin_unlock(&vma->vm_mm->page_table_lock); | |
1a5a9906 | 6848 | return 0; |
12724850 NH |
6849 | } |
6850 | ||
45f83cef AA |
6851 | if (pmd_trans_unstable(pmd)) |
6852 | return 0; | |
4ffef5fe DN |
6853 | retry: |
6854 | pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl); | |
6855 | for (; addr != end; addr += PAGE_SIZE) { | |
6856 | pte_t ptent = *(pte++); | |
02491447 | 6857 | swp_entry_t ent; |
4ffef5fe DN |
6858 | |
6859 | if (!mc.precharge) | |
6860 | break; | |
6861 | ||
8d32ff84 | 6862 | switch (get_mctgt_type(vma, addr, ptent, &target)) { |
4ffef5fe DN |
6863 | case MC_TARGET_PAGE: |
6864 | page = target.page; | |
6865 | if (isolate_lru_page(page)) | |
6866 | goto put; | |
6867 | pc = lookup_page_cgroup(page); | |
7ec99d62 | 6868 | if (!mem_cgroup_move_account(page, 1, pc, |
2f3479b1 | 6869 | mc.from, mc.to)) { |
4ffef5fe | 6870 | mc.precharge--; |
854ffa8d DN |
6871 | /* we uncharge from mc.from later. */ |
6872 | mc.moved_charge++; | |
4ffef5fe DN |
6873 | } |
6874 | putback_lru_page(page); | |
8d32ff84 | 6875 | put: /* get_mctgt_type() gets the page */ |
4ffef5fe DN |
6876 | put_page(page); |
6877 | break; | |
02491447 DN |
6878 | case MC_TARGET_SWAP: |
6879 | ent = target.ent; | |
e91cbb42 | 6880 | if (!mem_cgroup_move_swap_account(ent, mc.from, mc.to)) { |
02491447 | 6881 | mc.precharge--; |
483c30b5 DN |
6882 | /* we fixup refcnts and charges later. */ |
6883 | mc.moved_swap++; | |
6884 | } | |
02491447 | 6885 | break; |
4ffef5fe DN |
6886 | default: |
6887 | break; | |
6888 | } | |
6889 | } | |
6890 | pte_unmap_unlock(pte - 1, ptl); | |
6891 | cond_resched(); | |
6892 | ||
6893 | if (addr != end) { | |
6894 | /* | |
6895 | * We have consumed all precharges we got in can_attach(). | |
6896 | * We try charge one by one, but don't do any additional | |
6897 | * charges to mc.to if we have failed in charge once in attach() | |
6898 | * phase. | |
6899 | */ | |
854ffa8d | 6900 | ret = mem_cgroup_do_precharge(1); |
4ffef5fe DN |
6901 | if (!ret) |
6902 | goto retry; | |
6903 | } | |
6904 | ||
6905 | return ret; | |
6906 | } | |
6907 | ||
6908 | static void mem_cgroup_move_charge(struct mm_struct *mm) | |
6909 | { | |
6910 | struct vm_area_struct *vma; | |
6911 | ||
6912 | lru_add_drain_all(); | |
dfe076b0 DN |
6913 | retry: |
6914 | if (unlikely(!down_read_trylock(&mm->mmap_sem))) { | |
6915 | /* | |
6916 | * Someone who are holding the mmap_sem might be waiting in | |
6917 | * waitq. So we cancel all extra charges, wake up all waiters, | |
6918 | * and retry. Because we cancel precharges, we might not be able | |
6919 | * to move enough charges, but moving charge is a best-effort | |
6920 | * feature anyway, so it wouldn't be a big problem. | |
6921 | */ | |
6922 | __mem_cgroup_clear_mc(); | |
6923 | cond_resched(); | |
6924 | goto retry; | |
6925 | } | |
4ffef5fe DN |
6926 | for (vma = mm->mmap; vma; vma = vma->vm_next) { |
6927 | int ret; | |
6928 | struct mm_walk mem_cgroup_move_charge_walk = { | |
6929 | .pmd_entry = mem_cgroup_move_charge_pte_range, | |
6930 | .mm = mm, | |
6931 | .private = vma, | |
6932 | }; | |
6933 | if (is_vm_hugetlb_page(vma)) | |
6934 | continue; | |
4ffef5fe DN |
6935 | ret = walk_page_range(vma->vm_start, vma->vm_end, |
6936 | &mem_cgroup_move_charge_walk); | |
6937 | if (ret) | |
6938 | /* | |
6939 | * means we have consumed all precharges and failed in | |
6940 | * doing additional charge. Just abandon here. | |
6941 | */ | |
6942 | break; | |
6943 | } | |
dfe076b0 | 6944 | up_read(&mm->mmap_sem); |
7dc74be0 DN |
6945 | } |
6946 | ||
761b3ef5 LZ |
6947 | static void mem_cgroup_move_task(struct cgroup *cont, |
6948 | struct cgroup_taskset *tset) | |
67e465a7 | 6949 | { |
2f7ee569 | 6950 | struct task_struct *p = cgroup_taskset_first(tset); |
a433658c | 6951 | struct mm_struct *mm = get_task_mm(p); |
dfe076b0 | 6952 | |
dfe076b0 | 6953 | if (mm) { |
a433658c KM |
6954 | if (mc.to) |
6955 | mem_cgroup_move_charge(mm); | |
dfe076b0 DN |
6956 | mmput(mm); |
6957 | } | |
a433658c KM |
6958 | if (mc.to) |
6959 | mem_cgroup_clear_mc(); | |
67e465a7 | 6960 | } |
5cfb80a7 | 6961 | #else /* !CONFIG_MMU */ |
761b3ef5 LZ |
6962 | static int mem_cgroup_can_attach(struct cgroup *cgroup, |
6963 | struct cgroup_taskset *tset) | |
5cfb80a7 DN |
6964 | { |
6965 | return 0; | |
6966 | } | |
761b3ef5 LZ |
6967 | static void mem_cgroup_cancel_attach(struct cgroup *cgroup, |
6968 | struct cgroup_taskset *tset) | |
5cfb80a7 DN |
6969 | { |
6970 | } | |
761b3ef5 LZ |
6971 | static void mem_cgroup_move_task(struct cgroup *cont, |
6972 | struct cgroup_taskset *tset) | |
5cfb80a7 DN |
6973 | { |
6974 | } | |
6975 | #endif | |
67e465a7 | 6976 | |
f00baae7 TH |
6977 | /* |
6978 | * Cgroup retains root cgroups across [un]mount cycles making it necessary | |
6979 | * to verify sane_behavior flag on each mount attempt. | |
6980 | */ | |
6981 | static void mem_cgroup_bind(struct cgroup *root) | |
6982 | { | |
6983 | /* | |
6984 | * use_hierarchy is forced with sane_behavior. cgroup core | |
6985 | * guarantees that @root doesn't have any children, so turning it | |
6986 | * on for the root memcg is enough. | |
6987 | */ | |
6988 | if (cgroup_sane_behavior(root)) | |
6989 | mem_cgroup_from_cont(root)->use_hierarchy = true; | |
6990 | } | |
6991 | ||
8cdea7c0 BS |
6992 | struct cgroup_subsys mem_cgroup_subsys = { |
6993 | .name = "memory", | |
6994 | .subsys_id = mem_cgroup_subsys_id, | |
92fb9748 | 6995 | .css_alloc = mem_cgroup_css_alloc, |
d142e3e6 | 6996 | .css_online = mem_cgroup_css_online, |
92fb9748 TH |
6997 | .css_offline = mem_cgroup_css_offline, |
6998 | .css_free = mem_cgroup_css_free, | |
7dc74be0 DN |
6999 | .can_attach = mem_cgroup_can_attach, |
7000 | .cancel_attach = mem_cgroup_cancel_attach, | |
67e465a7 | 7001 | .attach = mem_cgroup_move_task, |
f00baae7 | 7002 | .bind = mem_cgroup_bind, |
6bc10349 | 7003 | .base_cftypes = mem_cgroup_files, |
6d12e2d8 | 7004 | .early_init = 0, |
04046e1a | 7005 | .use_id = 1, |
8cdea7c0 | 7006 | }; |
c077719b | 7007 | |
c255a458 | 7008 | #ifdef CONFIG_MEMCG_SWAP |
a42c390c MH |
7009 | static int __init enable_swap_account(char *s) |
7010 | { | |
7011 | /* consider enabled if no parameter or 1 is given */ | |
a2c8990a | 7012 | if (!strcmp(s, "1")) |
a42c390c | 7013 | really_do_swap_account = 1; |
a2c8990a | 7014 | else if (!strcmp(s, "0")) |
a42c390c MH |
7015 | really_do_swap_account = 0; |
7016 | return 1; | |
7017 | } | |
a2c8990a | 7018 | __setup("swapaccount=", enable_swap_account); |
c077719b | 7019 | |
2d11085e MH |
7020 | static void __init memsw_file_init(void) |
7021 | { | |
6acc8b02 MH |
7022 | WARN_ON(cgroup_add_cftypes(&mem_cgroup_subsys, memsw_cgroup_files)); |
7023 | } | |
7024 | ||
7025 | static void __init enable_swap_cgroup(void) | |
7026 | { | |
7027 | if (!mem_cgroup_disabled() && really_do_swap_account) { | |
7028 | do_swap_account = 1; | |
7029 | memsw_file_init(); | |
7030 | } | |
2d11085e | 7031 | } |
6acc8b02 | 7032 | |
2d11085e | 7033 | #else |
6acc8b02 | 7034 | static void __init enable_swap_cgroup(void) |
2d11085e MH |
7035 | { |
7036 | } | |
c077719b | 7037 | #endif |
2d11085e MH |
7038 | |
7039 | /* | |
1081312f MH |
7040 | * subsys_initcall() for memory controller. |
7041 | * | |
7042 | * Some parts like hotcpu_notifier() have to be initialized from this context | |
7043 | * because of lock dependencies (cgroup_lock -> cpu hotplug) but basically | |
7044 | * everything that doesn't depend on a specific mem_cgroup structure should | |
7045 | * be initialized from here. | |
2d11085e MH |
7046 | */ |
7047 | static int __init mem_cgroup_init(void) | |
7048 | { | |
7049 | hotcpu_notifier(memcg_cpu_hotplug_callback, 0); | |
6acc8b02 | 7050 | enable_swap_cgroup(); |
8787a1df | 7051 | mem_cgroup_soft_limit_tree_init(); |
e4777496 | 7052 | memcg_stock_init(); |
2d11085e MH |
7053 | return 0; |
7054 | } | |
7055 | subsys_initcall(mem_cgroup_init); |