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8cdea7c0 BS |
1 | /* memcontrol.c - Memory Controller |
2 | * | |
3 | * Copyright IBM Corporation, 2007 | |
4 | * Author Balbir Singh <balbir@linux.vnet.ibm.com> | |
5 | * | |
78fb7466 PE |
6 | * Copyright 2007 OpenVZ SWsoft Inc |
7 | * Author: Pavel Emelianov <xemul@openvz.org> | |
8 | * | |
2e72b634 KS |
9 | * Memory thresholds |
10 | * Copyright (C) 2009 Nokia Corporation | |
11 | * Author: Kirill A. Shutemov | |
12 | * | |
8cdea7c0 BS |
13 | * This program is free software; you can redistribute it and/or modify |
14 | * it under the terms of the GNU General Public License as published by | |
15 | * the Free Software Foundation; either version 2 of the License, or | |
16 | * (at your option) any later version. | |
17 | * | |
18 | * This program is distributed in the hope that it will be useful, | |
19 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
20 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
21 | * GNU General Public License for more details. | |
22 | */ | |
23 | ||
24 | #include <linux/res_counter.h> | |
25 | #include <linux/memcontrol.h> | |
26 | #include <linux/cgroup.h> | |
78fb7466 | 27 | #include <linux/mm.h> |
4ffef5fe | 28 | #include <linux/hugetlb.h> |
d13d1443 | 29 | #include <linux/pagemap.h> |
d52aa412 | 30 | #include <linux/smp.h> |
8a9f3ccd | 31 | #include <linux/page-flags.h> |
66e1707b | 32 | #include <linux/backing-dev.h> |
8a9f3ccd BS |
33 | #include <linux/bit_spinlock.h> |
34 | #include <linux/rcupdate.h> | |
e222432b | 35 | #include <linux/limits.h> |
b9e15baf | 36 | #include <linux/export.h> |
8c7c6e34 | 37 | #include <linux/mutex.h> |
f64c3f54 | 38 | #include <linux/rbtree.h> |
b6ac57d5 | 39 | #include <linux/slab.h> |
66e1707b | 40 | #include <linux/swap.h> |
02491447 | 41 | #include <linux/swapops.h> |
66e1707b | 42 | #include <linux/spinlock.h> |
2e72b634 KS |
43 | #include <linux/eventfd.h> |
44 | #include <linux/sort.h> | |
66e1707b | 45 | #include <linux/fs.h> |
d2ceb9b7 | 46 | #include <linux/seq_file.h> |
33327948 | 47 | #include <linux/vmalloc.h> |
b69408e8 | 48 | #include <linux/mm_inline.h> |
52d4b9ac | 49 | #include <linux/page_cgroup.h> |
cdec2e42 | 50 | #include <linux/cpu.h> |
158e0a2d | 51 | #include <linux/oom.h> |
08e552c6 | 52 | #include "internal.h" |
d1a4c0b3 | 53 | #include <net/sock.h> |
4bd2c1ee | 54 | #include <net/ip.h> |
d1a4c0b3 | 55 | #include <net/tcp_memcontrol.h> |
8cdea7c0 | 56 | |
8697d331 BS |
57 | #include <asm/uaccess.h> |
58 | ||
cc8e970c KM |
59 | #include <trace/events/vmscan.h> |
60 | ||
a181b0e8 | 61 | struct cgroup_subsys mem_cgroup_subsys __read_mostly; |
68ae564b DR |
62 | EXPORT_SYMBOL(mem_cgroup_subsys); |
63 | ||
a181b0e8 | 64 | #define MEM_CGROUP_RECLAIM_RETRIES 5 |
6bbda35c | 65 | static struct mem_cgroup *root_mem_cgroup __read_mostly; |
8cdea7c0 | 66 | |
c255a458 | 67 | #ifdef CONFIG_MEMCG_SWAP |
338c8431 | 68 | /* Turned on only when memory cgroup is enabled && really_do_swap_account = 1 */ |
c077719b | 69 | int do_swap_account __read_mostly; |
a42c390c MH |
70 | |
71 | /* for remember boot option*/ | |
c255a458 | 72 | #ifdef CONFIG_MEMCG_SWAP_ENABLED |
a42c390c MH |
73 | static int really_do_swap_account __initdata = 1; |
74 | #else | |
75 | static int really_do_swap_account __initdata = 0; | |
76 | #endif | |
77 | ||
c077719b | 78 | #else |
a0db00fc | 79 | #define do_swap_account 0 |
c077719b KH |
80 | #endif |
81 | ||
82 | ||
d52aa412 KH |
83 | /* |
84 | * Statistics for memory cgroup. | |
85 | */ | |
86 | enum mem_cgroup_stat_index { | |
87 | /* | |
88 | * For MEM_CONTAINER_TYPE_ALL, usage = pagecache + rss. | |
89 | */ | |
90 | MEM_CGROUP_STAT_CACHE, /* # of pages charged as cache */ | |
d69b042f | 91 | MEM_CGROUP_STAT_RSS, /* # of pages charged as anon rss */ |
d8046582 | 92 | MEM_CGROUP_STAT_FILE_MAPPED, /* # of pages charged as file rss */ |
bff6bb83 | 93 | MEM_CGROUP_STAT_SWAP, /* # of pages, swapped out */ |
d52aa412 KH |
94 | MEM_CGROUP_STAT_NSTATS, |
95 | }; | |
96 | ||
af7c4b0e JW |
97 | static const char * const mem_cgroup_stat_names[] = { |
98 | "cache", | |
99 | "rss", | |
100 | "mapped_file", | |
101 | "swap", | |
102 | }; | |
103 | ||
e9f8974f JW |
104 | enum mem_cgroup_events_index { |
105 | MEM_CGROUP_EVENTS_PGPGIN, /* # of pages paged in */ | |
106 | MEM_CGROUP_EVENTS_PGPGOUT, /* # of pages paged out */ | |
456f998e YH |
107 | MEM_CGROUP_EVENTS_PGFAULT, /* # of page-faults */ |
108 | MEM_CGROUP_EVENTS_PGMAJFAULT, /* # of major page-faults */ | |
e9f8974f JW |
109 | MEM_CGROUP_EVENTS_NSTATS, |
110 | }; | |
af7c4b0e JW |
111 | |
112 | static const char * const mem_cgroup_events_names[] = { | |
113 | "pgpgin", | |
114 | "pgpgout", | |
115 | "pgfault", | |
116 | "pgmajfault", | |
117 | }; | |
118 | ||
7a159cc9 JW |
119 | /* |
120 | * Per memcg event counter is incremented at every pagein/pageout. With THP, | |
121 | * it will be incremated by the number of pages. This counter is used for | |
122 | * for trigger some periodic events. This is straightforward and better | |
123 | * than using jiffies etc. to handle periodic memcg event. | |
124 | */ | |
125 | enum mem_cgroup_events_target { | |
126 | MEM_CGROUP_TARGET_THRESH, | |
127 | MEM_CGROUP_TARGET_SOFTLIMIT, | |
453a9bf3 | 128 | MEM_CGROUP_TARGET_NUMAINFO, |
7a159cc9 JW |
129 | MEM_CGROUP_NTARGETS, |
130 | }; | |
a0db00fc KS |
131 | #define THRESHOLDS_EVENTS_TARGET 128 |
132 | #define SOFTLIMIT_EVENTS_TARGET 1024 | |
133 | #define NUMAINFO_EVENTS_TARGET 1024 | |
e9f8974f | 134 | |
d52aa412 | 135 | struct mem_cgroup_stat_cpu { |
7a159cc9 | 136 | long count[MEM_CGROUP_STAT_NSTATS]; |
e9f8974f | 137 | unsigned long events[MEM_CGROUP_EVENTS_NSTATS]; |
13114716 | 138 | unsigned long nr_page_events; |
7a159cc9 | 139 | unsigned long targets[MEM_CGROUP_NTARGETS]; |
d52aa412 KH |
140 | }; |
141 | ||
527a5ec9 JW |
142 | struct mem_cgroup_reclaim_iter { |
143 | /* css_id of the last scanned hierarchy member */ | |
144 | int position; | |
145 | /* scan generation, increased every round-trip */ | |
146 | unsigned int generation; | |
147 | }; | |
148 | ||
6d12e2d8 KH |
149 | /* |
150 | * per-zone information in memory controller. | |
151 | */ | |
6d12e2d8 | 152 | struct mem_cgroup_per_zone { |
6290df54 | 153 | struct lruvec lruvec; |
1eb49272 | 154 | unsigned long lru_size[NR_LRU_LISTS]; |
3e2f41f1 | 155 | |
527a5ec9 JW |
156 | struct mem_cgroup_reclaim_iter reclaim_iter[DEF_PRIORITY + 1]; |
157 | ||
f64c3f54 BS |
158 | struct rb_node tree_node; /* RB tree node */ |
159 | unsigned long long usage_in_excess;/* Set to the value by which */ | |
160 | /* the soft limit is exceeded*/ | |
161 | bool on_tree; | |
d79154bb | 162 | struct mem_cgroup *memcg; /* Back pointer, we cannot */ |
4e416953 | 163 | /* use container_of */ |
6d12e2d8 | 164 | }; |
6d12e2d8 KH |
165 | |
166 | struct mem_cgroup_per_node { | |
167 | struct mem_cgroup_per_zone zoneinfo[MAX_NR_ZONES]; | |
168 | }; | |
169 | ||
170 | struct mem_cgroup_lru_info { | |
171 | struct mem_cgroup_per_node *nodeinfo[MAX_NUMNODES]; | |
172 | }; | |
173 | ||
f64c3f54 BS |
174 | /* |
175 | * Cgroups above their limits are maintained in a RB-Tree, independent of | |
176 | * their hierarchy representation | |
177 | */ | |
178 | ||
179 | struct mem_cgroup_tree_per_zone { | |
180 | struct rb_root rb_root; | |
181 | spinlock_t lock; | |
182 | }; | |
183 | ||
184 | struct mem_cgroup_tree_per_node { | |
185 | struct mem_cgroup_tree_per_zone rb_tree_per_zone[MAX_NR_ZONES]; | |
186 | }; | |
187 | ||
188 | struct mem_cgroup_tree { | |
189 | struct mem_cgroup_tree_per_node *rb_tree_per_node[MAX_NUMNODES]; | |
190 | }; | |
191 | ||
192 | static struct mem_cgroup_tree soft_limit_tree __read_mostly; | |
193 | ||
2e72b634 KS |
194 | struct mem_cgroup_threshold { |
195 | struct eventfd_ctx *eventfd; | |
196 | u64 threshold; | |
197 | }; | |
198 | ||
9490ff27 | 199 | /* For threshold */ |
2e72b634 | 200 | struct mem_cgroup_threshold_ary { |
748dad36 | 201 | /* An array index points to threshold just below or equal to usage. */ |
5407a562 | 202 | int current_threshold; |
2e72b634 KS |
203 | /* Size of entries[] */ |
204 | unsigned int size; | |
205 | /* Array of thresholds */ | |
206 | struct mem_cgroup_threshold entries[0]; | |
207 | }; | |
2c488db2 KS |
208 | |
209 | struct mem_cgroup_thresholds { | |
210 | /* Primary thresholds array */ | |
211 | struct mem_cgroup_threshold_ary *primary; | |
212 | /* | |
213 | * Spare threshold array. | |
214 | * This is needed to make mem_cgroup_unregister_event() "never fail". | |
215 | * It must be able to store at least primary->size - 1 entries. | |
216 | */ | |
217 | struct mem_cgroup_threshold_ary *spare; | |
218 | }; | |
219 | ||
9490ff27 KH |
220 | /* for OOM */ |
221 | struct mem_cgroup_eventfd_list { | |
222 | struct list_head list; | |
223 | struct eventfd_ctx *eventfd; | |
224 | }; | |
2e72b634 | 225 | |
c0ff4b85 R |
226 | static void mem_cgroup_threshold(struct mem_cgroup *memcg); |
227 | static void mem_cgroup_oom_notify(struct mem_cgroup *memcg); | |
2e72b634 | 228 | |
8cdea7c0 BS |
229 | /* |
230 | * The memory controller data structure. The memory controller controls both | |
231 | * page cache and RSS per cgroup. We would eventually like to provide | |
232 | * statistics based on the statistics developed by Rik Van Riel for clock-pro, | |
233 | * to help the administrator determine what knobs to tune. | |
234 | * | |
235 | * TODO: Add a water mark for the memory controller. Reclaim will begin when | |
8a9f3ccd BS |
236 | * we hit the water mark. May be even add a low water mark, such that |
237 | * no reclaim occurs from a cgroup at it's low water mark, this is | |
238 | * a feature that will be implemented much later in the future. | |
8cdea7c0 BS |
239 | */ |
240 | struct mem_cgroup { | |
241 | struct cgroup_subsys_state css; | |
242 | /* | |
243 | * the counter to account for memory usage | |
244 | */ | |
245 | struct res_counter res; | |
59927fb9 HD |
246 | |
247 | union { | |
248 | /* | |
249 | * the counter to account for mem+swap usage. | |
250 | */ | |
251 | struct res_counter memsw; | |
252 | ||
253 | /* | |
254 | * rcu_freeing is used only when freeing struct mem_cgroup, | |
255 | * so put it into a union to avoid wasting more memory. | |
256 | * It must be disjoint from the css field. It could be | |
257 | * in a union with the res field, but res plays a much | |
258 | * larger part in mem_cgroup life than memsw, and might | |
259 | * be of interest, even at time of free, when debugging. | |
260 | * So share rcu_head with the less interesting memsw. | |
261 | */ | |
262 | struct rcu_head rcu_freeing; | |
263 | /* | |
3afe36b1 GC |
264 | * We also need some space for a worker in deferred freeing. |
265 | * By the time we call it, rcu_freeing is no longer in use. | |
59927fb9 HD |
266 | */ |
267 | struct work_struct work_freeing; | |
268 | }; | |
269 | ||
78fb7466 PE |
270 | /* |
271 | * Per cgroup active and inactive list, similar to the | |
272 | * per zone LRU lists. | |
78fb7466 | 273 | */ |
6d12e2d8 | 274 | struct mem_cgroup_lru_info info; |
889976db YH |
275 | int last_scanned_node; |
276 | #if MAX_NUMNODES > 1 | |
277 | nodemask_t scan_nodes; | |
453a9bf3 KH |
278 | atomic_t numainfo_events; |
279 | atomic_t numainfo_updating; | |
889976db | 280 | #endif |
18f59ea7 BS |
281 | /* |
282 | * Should the accounting and control be hierarchical, per subtree? | |
283 | */ | |
284 | bool use_hierarchy; | |
79dfdacc MH |
285 | |
286 | bool oom_lock; | |
287 | atomic_t under_oom; | |
288 | ||
8c7c6e34 | 289 | atomic_t refcnt; |
14797e23 | 290 | |
1f4c025b | 291 | int swappiness; |
3c11ecf4 KH |
292 | /* OOM-Killer disable */ |
293 | int oom_kill_disable; | |
a7885eb8 | 294 | |
22a668d7 KH |
295 | /* set when res.limit == memsw.limit */ |
296 | bool memsw_is_minimum; | |
297 | ||
2e72b634 KS |
298 | /* protect arrays of thresholds */ |
299 | struct mutex thresholds_lock; | |
300 | ||
301 | /* thresholds for memory usage. RCU-protected */ | |
2c488db2 | 302 | struct mem_cgroup_thresholds thresholds; |
907860ed | 303 | |
2e72b634 | 304 | /* thresholds for mem+swap usage. RCU-protected */ |
2c488db2 | 305 | struct mem_cgroup_thresholds memsw_thresholds; |
907860ed | 306 | |
9490ff27 KH |
307 | /* For oom notifier event fd */ |
308 | struct list_head oom_notify; | |
185efc0f | 309 | |
7dc74be0 DN |
310 | /* |
311 | * Should we move charges of a task when a task is moved into this | |
312 | * mem_cgroup ? And what type of charges should we move ? | |
313 | */ | |
314 | unsigned long move_charge_at_immigrate; | |
619d094b KH |
315 | /* |
316 | * set > 0 if pages under this cgroup are moving to other cgroup. | |
317 | */ | |
318 | atomic_t moving_account; | |
312734c0 KH |
319 | /* taken only while moving_account > 0 */ |
320 | spinlock_t move_lock; | |
d52aa412 | 321 | /* |
c62b1a3b | 322 | * percpu counter. |
d52aa412 | 323 | */ |
3a7951b4 | 324 | struct mem_cgroup_stat_cpu __percpu *stat; |
711d3d2c KH |
325 | /* |
326 | * used when a cpu is offlined or other synchronizations | |
327 | * See mem_cgroup_read_stat(). | |
328 | */ | |
329 | struct mem_cgroup_stat_cpu nocpu_base; | |
330 | spinlock_t pcp_counter_lock; | |
d1a4c0b3 | 331 | |
4bd2c1ee | 332 | #if defined(CONFIG_MEMCG_KMEM) && defined(CONFIG_INET) |
d1a4c0b3 GC |
333 | struct tcp_memcontrol tcp_mem; |
334 | #endif | |
8cdea7c0 BS |
335 | }; |
336 | ||
7dc74be0 DN |
337 | /* Stuffs for move charges at task migration. */ |
338 | /* | |
339 | * Types of charges to be moved. "move_charge_at_immitgrate" is treated as a | |
340 | * left-shifted bitmap of these types. | |
341 | */ | |
342 | enum move_type { | |
4ffef5fe | 343 | MOVE_CHARGE_TYPE_ANON, /* private anonymous page and swap of it */ |
87946a72 | 344 | MOVE_CHARGE_TYPE_FILE, /* file page(including tmpfs) and swap of it */ |
7dc74be0 DN |
345 | NR_MOVE_TYPE, |
346 | }; | |
347 | ||
4ffef5fe DN |
348 | /* "mc" and its members are protected by cgroup_mutex */ |
349 | static struct move_charge_struct { | |
b1dd693e | 350 | spinlock_t lock; /* for from, to */ |
4ffef5fe DN |
351 | struct mem_cgroup *from; |
352 | struct mem_cgroup *to; | |
353 | unsigned long precharge; | |
854ffa8d | 354 | unsigned long moved_charge; |
483c30b5 | 355 | unsigned long moved_swap; |
8033b97c DN |
356 | struct task_struct *moving_task; /* a task moving charges */ |
357 | wait_queue_head_t waitq; /* a waitq for other context */ | |
358 | } mc = { | |
2bd9bb20 | 359 | .lock = __SPIN_LOCK_UNLOCKED(mc.lock), |
8033b97c DN |
360 | .waitq = __WAIT_QUEUE_HEAD_INITIALIZER(mc.waitq), |
361 | }; | |
4ffef5fe | 362 | |
90254a65 DN |
363 | static bool move_anon(void) |
364 | { | |
365 | return test_bit(MOVE_CHARGE_TYPE_ANON, | |
366 | &mc.to->move_charge_at_immigrate); | |
367 | } | |
368 | ||
87946a72 DN |
369 | static bool move_file(void) |
370 | { | |
371 | return test_bit(MOVE_CHARGE_TYPE_FILE, | |
372 | &mc.to->move_charge_at_immigrate); | |
373 | } | |
374 | ||
4e416953 BS |
375 | /* |
376 | * Maximum loops in mem_cgroup_hierarchical_reclaim(), used for soft | |
377 | * limit reclaim to prevent infinite loops, if they ever occur. | |
378 | */ | |
a0db00fc KS |
379 | #define MEM_CGROUP_MAX_RECLAIM_LOOPS 100 |
380 | #define MEM_CGROUP_MAX_SOFT_LIMIT_RECLAIM_LOOPS 2 | |
4e416953 | 381 | |
217bc319 KH |
382 | enum charge_type { |
383 | MEM_CGROUP_CHARGE_TYPE_CACHE = 0, | |
41326c17 | 384 | MEM_CGROUP_CHARGE_TYPE_ANON, |
d13d1443 | 385 | MEM_CGROUP_CHARGE_TYPE_SWAPOUT, /* for accounting swapcache */ |
8a9478ca | 386 | MEM_CGROUP_CHARGE_TYPE_DROP, /* a page was unused swap cache */ |
c05555b5 KH |
387 | NR_CHARGE_TYPE, |
388 | }; | |
389 | ||
8c7c6e34 | 390 | /* for encoding cft->private value on file */ |
86ae53e1 GC |
391 | enum res_type { |
392 | _MEM, | |
393 | _MEMSWAP, | |
394 | _OOM_TYPE, | |
395 | }; | |
396 | ||
a0db00fc KS |
397 | #define MEMFILE_PRIVATE(x, val) ((x) << 16 | (val)) |
398 | #define MEMFILE_TYPE(val) ((val) >> 16 & 0xffff) | |
8c7c6e34 | 399 | #define MEMFILE_ATTR(val) ((val) & 0xffff) |
9490ff27 KH |
400 | /* Used for OOM nofiier */ |
401 | #define OOM_CONTROL (0) | |
8c7c6e34 | 402 | |
75822b44 BS |
403 | /* |
404 | * Reclaim flags for mem_cgroup_hierarchical_reclaim | |
405 | */ | |
406 | #define MEM_CGROUP_RECLAIM_NOSWAP_BIT 0x0 | |
407 | #define MEM_CGROUP_RECLAIM_NOSWAP (1 << MEM_CGROUP_RECLAIM_NOSWAP_BIT) | |
408 | #define MEM_CGROUP_RECLAIM_SHRINK_BIT 0x1 | |
409 | #define MEM_CGROUP_RECLAIM_SHRINK (1 << MEM_CGROUP_RECLAIM_SHRINK_BIT) | |
410 | ||
c0ff4b85 R |
411 | static void mem_cgroup_get(struct mem_cgroup *memcg); |
412 | static void mem_cgroup_put(struct mem_cgroup *memcg); | |
e1aab161 | 413 | |
b2145145 WL |
414 | static inline |
415 | struct mem_cgroup *mem_cgroup_from_css(struct cgroup_subsys_state *s) | |
416 | { | |
417 | return container_of(s, struct mem_cgroup, css); | |
418 | } | |
419 | ||
7ffc0edc MH |
420 | static inline bool mem_cgroup_is_root(struct mem_cgroup *memcg) |
421 | { | |
422 | return (memcg == root_mem_cgroup); | |
423 | } | |
424 | ||
e1aab161 | 425 | /* Writing them here to avoid exposing memcg's inner layout */ |
4bd2c1ee | 426 | #if defined(CONFIG_INET) && defined(CONFIG_MEMCG_KMEM) |
e1aab161 | 427 | |
e1aab161 GC |
428 | void sock_update_memcg(struct sock *sk) |
429 | { | |
376be5ff | 430 | if (mem_cgroup_sockets_enabled) { |
e1aab161 | 431 | struct mem_cgroup *memcg; |
3f134619 | 432 | struct cg_proto *cg_proto; |
e1aab161 GC |
433 | |
434 | BUG_ON(!sk->sk_prot->proto_cgroup); | |
435 | ||
f3f511e1 GC |
436 | /* Socket cloning can throw us here with sk_cgrp already |
437 | * filled. It won't however, necessarily happen from | |
438 | * process context. So the test for root memcg given | |
439 | * the current task's memcg won't help us in this case. | |
440 | * | |
441 | * Respecting the original socket's memcg is a better | |
442 | * decision in this case. | |
443 | */ | |
444 | if (sk->sk_cgrp) { | |
445 | BUG_ON(mem_cgroup_is_root(sk->sk_cgrp->memcg)); | |
446 | mem_cgroup_get(sk->sk_cgrp->memcg); | |
447 | return; | |
448 | } | |
449 | ||
e1aab161 GC |
450 | rcu_read_lock(); |
451 | memcg = mem_cgroup_from_task(current); | |
3f134619 GC |
452 | cg_proto = sk->sk_prot->proto_cgroup(memcg); |
453 | if (!mem_cgroup_is_root(memcg) && memcg_proto_active(cg_proto)) { | |
e1aab161 | 454 | mem_cgroup_get(memcg); |
3f134619 | 455 | sk->sk_cgrp = cg_proto; |
e1aab161 GC |
456 | } |
457 | rcu_read_unlock(); | |
458 | } | |
459 | } | |
460 | EXPORT_SYMBOL(sock_update_memcg); | |
461 | ||
462 | void sock_release_memcg(struct sock *sk) | |
463 | { | |
376be5ff | 464 | if (mem_cgroup_sockets_enabled && sk->sk_cgrp) { |
e1aab161 GC |
465 | struct mem_cgroup *memcg; |
466 | WARN_ON(!sk->sk_cgrp->memcg); | |
467 | memcg = sk->sk_cgrp->memcg; | |
468 | mem_cgroup_put(memcg); | |
469 | } | |
470 | } | |
d1a4c0b3 GC |
471 | |
472 | struct cg_proto *tcp_proto_cgroup(struct mem_cgroup *memcg) | |
473 | { | |
474 | if (!memcg || mem_cgroup_is_root(memcg)) | |
475 | return NULL; | |
476 | ||
477 | return &memcg->tcp_mem.cg_proto; | |
478 | } | |
479 | EXPORT_SYMBOL(tcp_proto_cgroup); | |
e1aab161 | 480 | |
3f134619 GC |
481 | static void disarm_sock_keys(struct mem_cgroup *memcg) |
482 | { | |
483 | if (!memcg_proto_activated(&memcg->tcp_mem.cg_proto)) | |
484 | return; | |
485 | static_key_slow_dec(&memcg_socket_limit_enabled); | |
486 | } | |
487 | #else | |
488 | static void disarm_sock_keys(struct mem_cgroup *memcg) | |
489 | { | |
490 | } | |
491 | #endif | |
492 | ||
c0ff4b85 | 493 | static void drain_all_stock_async(struct mem_cgroup *memcg); |
8c7c6e34 | 494 | |
f64c3f54 | 495 | static struct mem_cgroup_per_zone * |
c0ff4b85 | 496 | mem_cgroup_zoneinfo(struct mem_cgroup *memcg, int nid, int zid) |
f64c3f54 | 497 | { |
c0ff4b85 | 498 | return &memcg->info.nodeinfo[nid]->zoneinfo[zid]; |
f64c3f54 BS |
499 | } |
500 | ||
c0ff4b85 | 501 | struct cgroup_subsys_state *mem_cgroup_css(struct mem_cgroup *memcg) |
d324236b | 502 | { |
c0ff4b85 | 503 | return &memcg->css; |
d324236b WF |
504 | } |
505 | ||
f64c3f54 | 506 | static struct mem_cgroup_per_zone * |
c0ff4b85 | 507 | page_cgroup_zoneinfo(struct mem_cgroup *memcg, struct page *page) |
f64c3f54 | 508 | { |
97a6c37b JW |
509 | int nid = page_to_nid(page); |
510 | int zid = page_zonenum(page); | |
f64c3f54 | 511 | |
c0ff4b85 | 512 | return mem_cgroup_zoneinfo(memcg, nid, zid); |
f64c3f54 BS |
513 | } |
514 | ||
515 | static struct mem_cgroup_tree_per_zone * | |
516 | soft_limit_tree_node_zone(int nid, int zid) | |
517 | { | |
518 | return &soft_limit_tree.rb_tree_per_node[nid]->rb_tree_per_zone[zid]; | |
519 | } | |
520 | ||
521 | static struct mem_cgroup_tree_per_zone * | |
522 | soft_limit_tree_from_page(struct page *page) | |
523 | { | |
524 | int nid = page_to_nid(page); | |
525 | int zid = page_zonenum(page); | |
526 | ||
527 | return &soft_limit_tree.rb_tree_per_node[nid]->rb_tree_per_zone[zid]; | |
528 | } | |
529 | ||
530 | static void | |
c0ff4b85 | 531 | __mem_cgroup_insert_exceeded(struct mem_cgroup *memcg, |
f64c3f54 | 532 | struct mem_cgroup_per_zone *mz, |
ef8745c1 KH |
533 | struct mem_cgroup_tree_per_zone *mctz, |
534 | unsigned long long new_usage_in_excess) | |
f64c3f54 BS |
535 | { |
536 | struct rb_node **p = &mctz->rb_root.rb_node; | |
537 | struct rb_node *parent = NULL; | |
538 | struct mem_cgroup_per_zone *mz_node; | |
539 | ||
540 | if (mz->on_tree) | |
541 | return; | |
542 | ||
ef8745c1 KH |
543 | mz->usage_in_excess = new_usage_in_excess; |
544 | if (!mz->usage_in_excess) | |
545 | return; | |
f64c3f54 BS |
546 | while (*p) { |
547 | parent = *p; | |
548 | mz_node = rb_entry(parent, struct mem_cgroup_per_zone, | |
549 | tree_node); | |
550 | if (mz->usage_in_excess < mz_node->usage_in_excess) | |
551 | p = &(*p)->rb_left; | |
552 | /* | |
553 | * We can't avoid mem cgroups that are over their soft | |
554 | * limit by the same amount | |
555 | */ | |
556 | else if (mz->usage_in_excess >= mz_node->usage_in_excess) | |
557 | p = &(*p)->rb_right; | |
558 | } | |
559 | rb_link_node(&mz->tree_node, parent, p); | |
560 | rb_insert_color(&mz->tree_node, &mctz->rb_root); | |
561 | mz->on_tree = true; | |
4e416953 BS |
562 | } |
563 | ||
564 | static void | |
c0ff4b85 | 565 | __mem_cgroup_remove_exceeded(struct mem_cgroup *memcg, |
4e416953 BS |
566 | struct mem_cgroup_per_zone *mz, |
567 | struct mem_cgroup_tree_per_zone *mctz) | |
568 | { | |
569 | if (!mz->on_tree) | |
570 | return; | |
571 | rb_erase(&mz->tree_node, &mctz->rb_root); | |
572 | mz->on_tree = false; | |
573 | } | |
574 | ||
f64c3f54 | 575 | static void |
c0ff4b85 | 576 | mem_cgroup_remove_exceeded(struct mem_cgroup *memcg, |
f64c3f54 BS |
577 | struct mem_cgroup_per_zone *mz, |
578 | struct mem_cgroup_tree_per_zone *mctz) | |
579 | { | |
580 | spin_lock(&mctz->lock); | |
c0ff4b85 | 581 | __mem_cgroup_remove_exceeded(memcg, mz, mctz); |
f64c3f54 BS |
582 | spin_unlock(&mctz->lock); |
583 | } | |
584 | ||
f64c3f54 | 585 | |
c0ff4b85 | 586 | static void mem_cgroup_update_tree(struct mem_cgroup *memcg, struct page *page) |
f64c3f54 | 587 | { |
ef8745c1 | 588 | unsigned long long excess; |
f64c3f54 BS |
589 | struct mem_cgroup_per_zone *mz; |
590 | struct mem_cgroup_tree_per_zone *mctz; | |
4e649152 KH |
591 | int nid = page_to_nid(page); |
592 | int zid = page_zonenum(page); | |
f64c3f54 BS |
593 | mctz = soft_limit_tree_from_page(page); |
594 | ||
595 | /* | |
4e649152 KH |
596 | * Necessary to update all ancestors when hierarchy is used. |
597 | * because their event counter is not touched. | |
f64c3f54 | 598 | */ |
c0ff4b85 R |
599 | for (; memcg; memcg = parent_mem_cgroup(memcg)) { |
600 | mz = mem_cgroup_zoneinfo(memcg, nid, zid); | |
601 | excess = res_counter_soft_limit_excess(&memcg->res); | |
4e649152 KH |
602 | /* |
603 | * We have to update the tree if mz is on RB-tree or | |
604 | * mem is over its softlimit. | |
605 | */ | |
ef8745c1 | 606 | if (excess || mz->on_tree) { |
4e649152 KH |
607 | spin_lock(&mctz->lock); |
608 | /* if on-tree, remove it */ | |
609 | if (mz->on_tree) | |
c0ff4b85 | 610 | __mem_cgroup_remove_exceeded(memcg, mz, mctz); |
4e649152 | 611 | /* |
ef8745c1 KH |
612 | * Insert again. mz->usage_in_excess will be updated. |
613 | * If excess is 0, no tree ops. | |
4e649152 | 614 | */ |
c0ff4b85 | 615 | __mem_cgroup_insert_exceeded(memcg, mz, mctz, excess); |
4e649152 KH |
616 | spin_unlock(&mctz->lock); |
617 | } | |
f64c3f54 BS |
618 | } |
619 | } | |
620 | ||
c0ff4b85 | 621 | static void mem_cgroup_remove_from_trees(struct mem_cgroup *memcg) |
f64c3f54 BS |
622 | { |
623 | int node, zone; | |
624 | struct mem_cgroup_per_zone *mz; | |
625 | struct mem_cgroup_tree_per_zone *mctz; | |
626 | ||
3ed28fa1 | 627 | for_each_node(node) { |
f64c3f54 | 628 | for (zone = 0; zone < MAX_NR_ZONES; zone++) { |
c0ff4b85 | 629 | mz = mem_cgroup_zoneinfo(memcg, node, zone); |
f64c3f54 | 630 | mctz = soft_limit_tree_node_zone(node, zone); |
c0ff4b85 | 631 | mem_cgroup_remove_exceeded(memcg, mz, mctz); |
f64c3f54 BS |
632 | } |
633 | } | |
634 | } | |
635 | ||
4e416953 BS |
636 | static struct mem_cgroup_per_zone * |
637 | __mem_cgroup_largest_soft_limit_node(struct mem_cgroup_tree_per_zone *mctz) | |
638 | { | |
639 | struct rb_node *rightmost = NULL; | |
26251eaf | 640 | struct mem_cgroup_per_zone *mz; |
4e416953 BS |
641 | |
642 | retry: | |
26251eaf | 643 | mz = NULL; |
4e416953 BS |
644 | rightmost = rb_last(&mctz->rb_root); |
645 | if (!rightmost) | |
646 | goto done; /* Nothing to reclaim from */ | |
647 | ||
648 | mz = rb_entry(rightmost, struct mem_cgroup_per_zone, tree_node); | |
649 | /* | |
650 | * Remove the node now but someone else can add it back, | |
651 | * we will to add it back at the end of reclaim to its correct | |
652 | * position in the tree. | |
653 | */ | |
d79154bb HD |
654 | __mem_cgroup_remove_exceeded(mz->memcg, mz, mctz); |
655 | if (!res_counter_soft_limit_excess(&mz->memcg->res) || | |
656 | !css_tryget(&mz->memcg->css)) | |
4e416953 BS |
657 | goto retry; |
658 | done: | |
659 | return mz; | |
660 | } | |
661 | ||
662 | static struct mem_cgroup_per_zone * | |
663 | mem_cgroup_largest_soft_limit_node(struct mem_cgroup_tree_per_zone *mctz) | |
664 | { | |
665 | struct mem_cgroup_per_zone *mz; | |
666 | ||
667 | spin_lock(&mctz->lock); | |
668 | mz = __mem_cgroup_largest_soft_limit_node(mctz); | |
669 | spin_unlock(&mctz->lock); | |
670 | return mz; | |
671 | } | |
672 | ||
711d3d2c KH |
673 | /* |
674 | * Implementation Note: reading percpu statistics for memcg. | |
675 | * | |
676 | * Both of vmstat[] and percpu_counter has threshold and do periodic | |
677 | * synchronization to implement "quick" read. There are trade-off between | |
678 | * reading cost and precision of value. Then, we may have a chance to implement | |
679 | * a periodic synchronizion of counter in memcg's counter. | |
680 | * | |
681 | * But this _read() function is used for user interface now. The user accounts | |
682 | * memory usage by memory cgroup and he _always_ requires exact value because | |
683 | * he accounts memory. Even if we provide quick-and-fuzzy read, we always | |
684 | * have to visit all online cpus and make sum. So, for now, unnecessary | |
685 | * synchronization is not implemented. (just implemented for cpu hotplug) | |
686 | * | |
687 | * If there are kernel internal actions which can make use of some not-exact | |
688 | * value, and reading all cpu value can be performance bottleneck in some | |
689 | * common workload, threashold and synchonization as vmstat[] should be | |
690 | * implemented. | |
691 | */ | |
c0ff4b85 | 692 | static long mem_cgroup_read_stat(struct mem_cgroup *memcg, |
7a159cc9 | 693 | enum mem_cgroup_stat_index idx) |
c62b1a3b | 694 | { |
7a159cc9 | 695 | long val = 0; |
c62b1a3b | 696 | int cpu; |
c62b1a3b | 697 | |
711d3d2c KH |
698 | get_online_cpus(); |
699 | for_each_online_cpu(cpu) | |
c0ff4b85 | 700 | val += per_cpu(memcg->stat->count[idx], cpu); |
711d3d2c | 701 | #ifdef CONFIG_HOTPLUG_CPU |
c0ff4b85 R |
702 | spin_lock(&memcg->pcp_counter_lock); |
703 | val += memcg->nocpu_base.count[idx]; | |
704 | spin_unlock(&memcg->pcp_counter_lock); | |
711d3d2c KH |
705 | #endif |
706 | put_online_cpus(); | |
c62b1a3b KH |
707 | return val; |
708 | } | |
709 | ||
c0ff4b85 | 710 | static void mem_cgroup_swap_statistics(struct mem_cgroup *memcg, |
0c3e73e8 BS |
711 | bool charge) |
712 | { | |
713 | int val = (charge) ? 1 : -1; | |
bff6bb83 | 714 | this_cpu_add(memcg->stat->count[MEM_CGROUP_STAT_SWAP], val); |
0c3e73e8 BS |
715 | } |
716 | ||
c0ff4b85 | 717 | static unsigned long mem_cgroup_read_events(struct mem_cgroup *memcg, |
e9f8974f JW |
718 | enum mem_cgroup_events_index idx) |
719 | { | |
720 | unsigned long val = 0; | |
721 | int cpu; | |
722 | ||
723 | for_each_online_cpu(cpu) | |
c0ff4b85 | 724 | val += per_cpu(memcg->stat->events[idx], cpu); |
e9f8974f | 725 | #ifdef CONFIG_HOTPLUG_CPU |
c0ff4b85 R |
726 | spin_lock(&memcg->pcp_counter_lock); |
727 | val += memcg->nocpu_base.events[idx]; | |
728 | spin_unlock(&memcg->pcp_counter_lock); | |
e9f8974f JW |
729 | #endif |
730 | return val; | |
731 | } | |
732 | ||
c0ff4b85 | 733 | static void mem_cgroup_charge_statistics(struct mem_cgroup *memcg, |
b2402857 | 734 | bool anon, int nr_pages) |
d52aa412 | 735 | { |
c62b1a3b KH |
736 | preempt_disable(); |
737 | ||
b2402857 KH |
738 | /* |
739 | * Here, RSS means 'mapped anon' and anon's SwapCache. Shmem/tmpfs is | |
740 | * counted as CACHE even if it's on ANON LRU. | |
741 | */ | |
742 | if (anon) | |
743 | __this_cpu_add(memcg->stat->count[MEM_CGROUP_STAT_RSS], | |
c0ff4b85 | 744 | nr_pages); |
d52aa412 | 745 | else |
b2402857 | 746 | __this_cpu_add(memcg->stat->count[MEM_CGROUP_STAT_CACHE], |
c0ff4b85 | 747 | nr_pages); |
55e462b0 | 748 | |
e401f176 KH |
749 | /* pagein of a big page is an event. So, ignore page size */ |
750 | if (nr_pages > 0) | |
c0ff4b85 | 751 | __this_cpu_inc(memcg->stat->events[MEM_CGROUP_EVENTS_PGPGIN]); |
3751d604 | 752 | else { |
c0ff4b85 | 753 | __this_cpu_inc(memcg->stat->events[MEM_CGROUP_EVENTS_PGPGOUT]); |
3751d604 KH |
754 | nr_pages = -nr_pages; /* for event */ |
755 | } | |
e401f176 | 756 | |
13114716 | 757 | __this_cpu_add(memcg->stat->nr_page_events, nr_pages); |
2e72b634 | 758 | |
c62b1a3b | 759 | preempt_enable(); |
6d12e2d8 KH |
760 | } |
761 | ||
bb2a0de9 | 762 | unsigned long |
4d7dcca2 | 763 | mem_cgroup_get_lru_size(struct lruvec *lruvec, enum lru_list lru) |
074291fe KK |
764 | { |
765 | struct mem_cgroup_per_zone *mz; | |
766 | ||
767 | mz = container_of(lruvec, struct mem_cgroup_per_zone, lruvec); | |
768 | return mz->lru_size[lru]; | |
769 | } | |
770 | ||
771 | static unsigned long | |
c0ff4b85 | 772 | mem_cgroup_zone_nr_lru_pages(struct mem_cgroup *memcg, int nid, int zid, |
bb2a0de9 | 773 | unsigned int lru_mask) |
889976db YH |
774 | { |
775 | struct mem_cgroup_per_zone *mz; | |
f156ab93 | 776 | enum lru_list lru; |
bb2a0de9 KH |
777 | unsigned long ret = 0; |
778 | ||
c0ff4b85 | 779 | mz = mem_cgroup_zoneinfo(memcg, nid, zid); |
bb2a0de9 | 780 | |
f156ab93 HD |
781 | for_each_lru(lru) { |
782 | if (BIT(lru) & lru_mask) | |
783 | ret += mz->lru_size[lru]; | |
bb2a0de9 KH |
784 | } |
785 | return ret; | |
786 | } | |
787 | ||
788 | static unsigned long | |
c0ff4b85 | 789 | mem_cgroup_node_nr_lru_pages(struct mem_cgroup *memcg, |
bb2a0de9 KH |
790 | int nid, unsigned int lru_mask) |
791 | { | |
889976db YH |
792 | u64 total = 0; |
793 | int zid; | |
794 | ||
bb2a0de9 | 795 | for (zid = 0; zid < MAX_NR_ZONES; zid++) |
c0ff4b85 R |
796 | total += mem_cgroup_zone_nr_lru_pages(memcg, |
797 | nid, zid, lru_mask); | |
bb2a0de9 | 798 | |
889976db YH |
799 | return total; |
800 | } | |
bb2a0de9 | 801 | |
c0ff4b85 | 802 | static unsigned long mem_cgroup_nr_lru_pages(struct mem_cgroup *memcg, |
bb2a0de9 | 803 | unsigned int lru_mask) |
6d12e2d8 | 804 | { |
889976db | 805 | int nid; |
6d12e2d8 KH |
806 | u64 total = 0; |
807 | ||
31aaea4a | 808 | for_each_node_state(nid, N_MEMORY) |
c0ff4b85 | 809 | total += mem_cgroup_node_nr_lru_pages(memcg, nid, lru_mask); |
6d12e2d8 | 810 | return total; |
d52aa412 KH |
811 | } |
812 | ||
f53d7ce3 JW |
813 | static bool mem_cgroup_event_ratelimit(struct mem_cgroup *memcg, |
814 | enum mem_cgroup_events_target target) | |
7a159cc9 JW |
815 | { |
816 | unsigned long val, next; | |
817 | ||
13114716 | 818 | val = __this_cpu_read(memcg->stat->nr_page_events); |
4799401f | 819 | next = __this_cpu_read(memcg->stat->targets[target]); |
7a159cc9 | 820 | /* from time_after() in jiffies.h */ |
f53d7ce3 JW |
821 | if ((long)next - (long)val < 0) { |
822 | switch (target) { | |
823 | case MEM_CGROUP_TARGET_THRESH: | |
824 | next = val + THRESHOLDS_EVENTS_TARGET; | |
825 | break; | |
826 | case MEM_CGROUP_TARGET_SOFTLIMIT: | |
827 | next = val + SOFTLIMIT_EVENTS_TARGET; | |
828 | break; | |
829 | case MEM_CGROUP_TARGET_NUMAINFO: | |
830 | next = val + NUMAINFO_EVENTS_TARGET; | |
831 | break; | |
832 | default: | |
833 | break; | |
834 | } | |
835 | __this_cpu_write(memcg->stat->targets[target], next); | |
836 | return true; | |
7a159cc9 | 837 | } |
f53d7ce3 | 838 | return false; |
d2265e6f KH |
839 | } |
840 | ||
841 | /* | |
842 | * Check events in order. | |
843 | * | |
844 | */ | |
c0ff4b85 | 845 | static void memcg_check_events(struct mem_cgroup *memcg, struct page *page) |
d2265e6f | 846 | { |
4799401f | 847 | preempt_disable(); |
d2265e6f | 848 | /* threshold event is triggered in finer grain than soft limit */ |
f53d7ce3 JW |
849 | if (unlikely(mem_cgroup_event_ratelimit(memcg, |
850 | MEM_CGROUP_TARGET_THRESH))) { | |
82b3f2a7 AM |
851 | bool do_softlimit; |
852 | bool do_numainfo __maybe_unused; | |
f53d7ce3 JW |
853 | |
854 | do_softlimit = mem_cgroup_event_ratelimit(memcg, | |
855 | MEM_CGROUP_TARGET_SOFTLIMIT); | |
856 | #if MAX_NUMNODES > 1 | |
857 | do_numainfo = mem_cgroup_event_ratelimit(memcg, | |
858 | MEM_CGROUP_TARGET_NUMAINFO); | |
859 | #endif | |
860 | preempt_enable(); | |
861 | ||
c0ff4b85 | 862 | mem_cgroup_threshold(memcg); |
f53d7ce3 | 863 | if (unlikely(do_softlimit)) |
c0ff4b85 | 864 | mem_cgroup_update_tree(memcg, page); |
453a9bf3 | 865 | #if MAX_NUMNODES > 1 |
f53d7ce3 | 866 | if (unlikely(do_numainfo)) |
c0ff4b85 | 867 | atomic_inc(&memcg->numainfo_events); |
453a9bf3 | 868 | #endif |
f53d7ce3 JW |
869 | } else |
870 | preempt_enable(); | |
d2265e6f KH |
871 | } |
872 | ||
d1a4c0b3 | 873 | struct mem_cgroup *mem_cgroup_from_cont(struct cgroup *cont) |
8cdea7c0 | 874 | { |
b2145145 WL |
875 | return mem_cgroup_from_css( |
876 | cgroup_subsys_state(cont, mem_cgroup_subsys_id)); | |
8cdea7c0 BS |
877 | } |
878 | ||
cf475ad2 | 879 | struct mem_cgroup *mem_cgroup_from_task(struct task_struct *p) |
78fb7466 | 880 | { |
31a78f23 BS |
881 | /* |
882 | * mm_update_next_owner() may clear mm->owner to NULL | |
883 | * if it races with swapoff, page migration, etc. | |
884 | * So this can be called with p == NULL. | |
885 | */ | |
886 | if (unlikely(!p)) | |
887 | return NULL; | |
888 | ||
b2145145 | 889 | return mem_cgroup_from_css(task_subsys_state(p, mem_cgroup_subsys_id)); |
78fb7466 PE |
890 | } |
891 | ||
a433658c | 892 | struct mem_cgroup *try_get_mem_cgroup_from_mm(struct mm_struct *mm) |
54595fe2 | 893 | { |
c0ff4b85 | 894 | struct mem_cgroup *memcg = NULL; |
0b7f569e KH |
895 | |
896 | if (!mm) | |
897 | return NULL; | |
54595fe2 KH |
898 | /* |
899 | * Because we have no locks, mm->owner's may be being moved to other | |
900 | * cgroup. We use css_tryget() here even if this looks | |
901 | * pessimistic (rather than adding locks here). | |
902 | */ | |
903 | rcu_read_lock(); | |
904 | do { | |
c0ff4b85 R |
905 | memcg = mem_cgroup_from_task(rcu_dereference(mm->owner)); |
906 | if (unlikely(!memcg)) | |
54595fe2 | 907 | break; |
c0ff4b85 | 908 | } while (!css_tryget(&memcg->css)); |
54595fe2 | 909 | rcu_read_unlock(); |
c0ff4b85 | 910 | return memcg; |
54595fe2 KH |
911 | } |
912 | ||
5660048c JW |
913 | /** |
914 | * mem_cgroup_iter - iterate over memory cgroup hierarchy | |
915 | * @root: hierarchy root | |
916 | * @prev: previously returned memcg, NULL on first invocation | |
917 | * @reclaim: cookie for shared reclaim walks, NULL for full walks | |
918 | * | |
919 | * Returns references to children of the hierarchy below @root, or | |
920 | * @root itself, or %NULL after a full round-trip. | |
921 | * | |
922 | * Caller must pass the return value in @prev on subsequent | |
923 | * invocations for reference counting, or use mem_cgroup_iter_break() | |
924 | * to cancel a hierarchy walk before the round-trip is complete. | |
925 | * | |
926 | * Reclaimers can specify a zone and a priority level in @reclaim to | |
927 | * divide up the memcgs in the hierarchy among all concurrent | |
928 | * reclaimers operating on the same zone and priority. | |
929 | */ | |
930 | struct mem_cgroup *mem_cgroup_iter(struct mem_cgroup *root, | |
931 | struct mem_cgroup *prev, | |
932 | struct mem_cgroup_reclaim_cookie *reclaim) | |
14067bb3 | 933 | { |
9f3a0d09 JW |
934 | struct mem_cgroup *memcg = NULL; |
935 | int id = 0; | |
711d3d2c | 936 | |
5660048c JW |
937 | if (mem_cgroup_disabled()) |
938 | return NULL; | |
939 | ||
9f3a0d09 JW |
940 | if (!root) |
941 | root = root_mem_cgroup; | |
7d74b06f | 942 | |
9f3a0d09 JW |
943 | if (prev && !reclaim) |
944 | id = css_id(&prev->css); | |
14067bb3 | 945 | |
9f3a0d09 JW |
946 | if (prev && prev != root) |
947 | css_put(&prev->css); | |
14067bb3 | 948 | |
9f3a0d09 JW |
949 | if (!root->use_hierarchy && root != root_mem_cgroup) { |
950 | if (prev) | |
951 | return NULL; | |
952 | return root; | |
953 | } | |
14067bb3 | 954 | |
9f3a0d09 | 955 | while (!memcg) { |
527a5ec9 | 956 | struct mem_cgroup_reclaim_iter *uninitialized_var(iter); |
9f3a0d09 | 957 | struct cgroup_subsys_state *css; |
711d3d2c | 958 | |
527a5ec9 JW |
959 | if (reclaim) { |
960 | int nid = zone_to_nid(reclaim->zone); | |
961 | int zid = zone_idx(reclaim->zone); | |
962 | struct mem_cgroup_per_zone *mz; | |
963 | ||
964 | mz = mem_cgroup_zoneinfo(root, nid, zid); | |
965 | iter = &mz->reclaim_iter[reclaim->priority]; | |
966 | if (prev && reclaim->generation != iter->generation) | |
967 | return NULL; | |
968 | id = iter->position; | |
969 | } | |
7d74b06f | 970 | |
9f3a0d09 JW |
971 | rcu_read_lock(); |
972 | css = css_get_next(&mem_cgroup_subsys, id + 1, &root->css, &id); | |
973 | if (css) { | |
974 | if (css == &root->css || css_tryget(css)) | |
b2145145 | 975 | memcg = mem_cgroup_from_css(css); |
9f3a0d09 JW |
976 | } else |
977 | id = 0; | |
14067bb3 | 978 | rcu_read_unlock(); |
14067bb3 | 979 | |
527a5ec9 JW |
980 | if (reclaim) { |
981 | iter->position = id; | |
982 | if (!css) | |
983 | iter->generation++; | |
984 | else if (!prev && memcg) | |
985 | reclaim->generation = iter->generation; | |
986 | } | |
9f3a0d09 JW |
987 | |
988 | if (prev && !css) | |
989 | return NULL; | |
990 | } | |
991 | return memcg; | |
14067bb3 | 992 | } |
7d74b06f | 993 | |
5660048c JW |
994 | /** |
995 | * mem_cgroup_iter_break - abort a hierarchy walk prematurely | |
996 | * @root: hierarchy root | |
997 | * @prev: last visited hierarchy member as returned by mem_cgroup_iter() | |
998 | */ | |
999 | void mem_cgroup_iter_break(struct mem_cgroup *root, | |
1000 | struct mem_cgroup *prev) | |
9f3a0d09 JW |
1001 | { |
1002 | if (!root) | |
1003 | root = root_mem_cgroup; | |
1004 | if (prev && prev != root) | |
1005 | css_put(&prev->css); | |
1006 | } | |
7d74b06f | 1007 | |
9f3a0d09 JW |
1008 | /* |
1009 | * Iteration constructs for visiting all cgroups (under a tree). If | |
1010 | * loops are exited prematurely (break), mem_cgroup_iter_break() must | |
1011 | * be used for reference counting. | |
1012 | */ | |
1013 | #define for_each_mem_cgroup_tree(iter, root) \ | |
527a5ec9 | 1014 | for (iter = mem_cgroup_iter(root, NULL, NULL); \ |
9f3a0d09 | 1015 | iter != NULL; \ |
527a5ec9 | 1016 | iter = mem_cgroup_iter(root, iter, NULL)) |
711d3d2c | 1017 | |
9f3a0d09 | 1018 | #define for_each_mem_cgroup(iter) \ |
527a5ec9 | 1019 | for (iter = mem_cgroup_iter(NULL, NULL, NULL); \ |
9f3a0d09 | 1020 | iter != NULL; \ |
527a5ec9 | 1021 | iter = mem_cgroup_iter(NULL, iter, NULL)) |
14067bb3 | 1022 | |
68ae564b | 1023 | void __mem_cgroup_count_vm_event(struct mm_struct *mm, enum vm_event_item idx) |
456f998e | 1024 | { |
c0ff4b85 | 1025 | struct mem_cgroup *memcg; |
456f998e | 1026 | |
456f998e | 1027 | rcu_read_lock(); |
c0ff4b85 R |
1028 | memcg = mem_cgroup_from_task(rcu_dereference(mm->owner)); |
1029 | if (unlikely(!memcg)) | |
456f998e YH |
1030 | goto out; |
1031 | ||
1032 | switch (idx) { | |
456f998e | 1033 | case PGFAULT: |
0e574a93 JW |
1034 | this_cpu_inc(memcg->stat->events[MEM_CGROUP_EVENTS_PGFAULT]); |
1035 | break; | |
1036 | case PGMAJFAULT: | |
1037 | this_cpu_inc(memcg->stat->events[MEM_CGROUP_EVENTS_PGMAJFAULT]); | |
456f998e YH |
1038 | break; |
1039 | default: | |
1040 | BUG(); | |
1041 | } | |
1042 | out: | |
1043 | rcu_read_unlock(); | |
1044 | } | |
68ae564b | 1045 | EXPORT_SYMBOL(__mem_cgroup_count_vm_event); |
456f998e | 1046 | |
925b7673 JW |
1047 | /** |
1048 | * mem_cgroup_zone_lruvec - get the lru list vector for a zone and memcg | |
1049 | * @zone: zone of the wanted lruvec | |
fa9add64 | 1050 | * @memcg: memcg of the wanted lruvec |
925b7673 JW |
1051 | * |
1052 | * Returns the lru list vector holding pages for the given @zone and | |
1053 | * @mem. This can be the global zone lruvec, if the memory controller | |
1054 | * is disabled. | |
1055 | */ | |
1056 | struct lruvec *mem_cgroup_zone_lruvec(struct zone *zone, | |
1057 | struct mem_cgroup *memcg) | |
1058 | { | |
1059 | struct mem_cgroup_per_zone *mz; | |
bea8c150 | 1060 | struct lruvec *lruvec; |
925b7673 | 1061 | |
bea8c150 HD |
1062 | if (mem_cgroup_disabled()) { |
1063 | lruvec = &zone->lruvec; | |
1064 | goto out; | |
1065 | } | |
925b7673 JW |
1066 | |
1067 | mz = mem_cgroup_zoneinfo(memcg, zone_to_nid(zone), zone_idx(zone)); | |
bea8c150 HD |
1068 | lruvec = &mz->lruvec; |
1069 | out: | |
1070 | /* | |
1071 | * Since a node can be onlined after the mem_cgroup was created, | |
1072 | * we have to be prepared to initialize lruvec->zone here; | |
1073 | * and if offlined then reonlined, we need to reinitialize it. | |
1074 | */ | |
1075 | if (unlikely(lruvec->zone != zone)) | |
1076 | lruvec->zone = zone; | |
1077 | return lruvec; | |
925b7673 JW |
1078 | } |
1079 | ||
08e552c6 KH |
1080 | /* |
1081 | * Following LRU functions are allowed to be used without PCG_LOCK. | |
1082 | * Operations are called by routine of global LRU independently from memcg. | |
1083 | * What we have to take care of here is validness of pc->mem_cgroup. | |
1084 | * | |
1085 | * Changes to pc->mem_cgroup happens when | |
1086 | * 1. charge | |
1087 | * 2. moving account | |
1088 | * In typical case, "charge" is done before add-to-lru. Exception is SwapCache. | |
1089 | * It is added to LRU before charge. | |
1090 | * If PCG_USED bit is not set, page_cgroup is not added to this private LRU. | |
1091 | * When moving account, the page is not on LRU. It's isolated. | |
1092 | */ | |
4f98a2fe | 1093 | |
925b7673 | 1094 | /** |
fa9add64 | 1095 | * mem_cgroup_page_lruvec - return lruvec for adding an lru page |
925b7673 | 1096 | * @page: the page |
fa9add64 | 1097 | * @zone: zone of the page |
925b7673 | 1098 | */ |
fa9add64 | 1099 | struct lruvec *mem_cgroup_page_lruvec(struct page *page, struct zone *zone) |
08e552c6 | 1100 | { |
08e552c6 | 1101 | struct mem_cgroup_per_zone *mz; |
925b7673 JW |
1102 | struct mem_cgroup *memcg; |
1103 | struct page_cgroup *pc; | |
bea8c150 | 1104 | struct lruvec *lruvec; |
6d12e2d8 | 1105 | |
bea8c150 HD |
1106 | if (mem_cgroup_disabled()) { |
1107 | lruvec = &zone->lruvec; | |
1108 | goto out; | |
1109 | } | |
925b7673 | 1110 | |
08e552c6 | 1111 | pc = lookup_page_cgroup(page); |
38c5d72f | 1112 | memcg = pc->mem_cgroup; |
7512102c HD |
1113 | |
1114 | /* | |
fa9add64 | 1115 | * Surreptitiously switch any uncharged offlist page to root: |
7512102c HD |
1116 | * an uncharged page off lru does nothing to secure |
1117 | * its former mem_cgroup from sudden removal. | |
1118 | * | |
1119 | * Our caller holds lru_lock, and PageCgroupUsed is updated | |
1120 | * under page_cgroup lock: between them, they make all uses | |
1121 | * of pc->mem_cgroup safe. | |
1122 | */ | |
fa9add64 | 1123 | if (!PageLRU(page) && !PageCgroupUsed(pc) && memcg != root_mem_cgroup) |
7512102c HD |
1124 | pc->mem_cgroup = memcg = root_mem_cgroup; |
1125 | ||
925b7673 | 1126 | mz = page_cgroup_zoneinfo(memcg, page); |
bea8c150 HD |
1127 | lruvec = &mz->lruvec; |
1128 | out: | |
1129 | /* | |
1130 | * Since a node can be onlined after the mem_cgroup was created, | |
1131 | * we have to be prepared to initialize lruvec->zone here; | |
1132 | * and if offlined then reonlined, we need to reinitialize it. | |
1133 | */ | |
1134 | if (unlikely(lruvec->zone != zone)) | |
1135 | lruvec->zone = zone; | |
1136 | return lruvec; | |
08e552c6 | 1137 | } |
b69408e8 | 1138 | |
925b7673 | 1139 | /** |
fa9add64 HD |
1140 | * mem_cgroup_update_lru_size - account for adding or removing an lru page |
1141 | * @lruvec: mem_cgroup per zone lru vector | |
1142 | * @lru: index of lru list the page is sitting on | |
1143 | * @nr_pages: positive when adding or negative when removing | |
925b7673 | 1144 | * |
fa9add64 HD |
1145 | * This function must be called when a page is added to or removed from an |
1146 | * lru list. | |
3f58a829 | 1147 | */ |
fa9add64 HD |
1148 | void mem_cgroup_update_lru_size(struct lruvec *lruvec, enum lru_list lru, |
1149 | int nr_pages) | |
3f58a829 MK |
1150 | { |
1151 | struct mem_cgroup_per_zone *mz; | |
fa9add64 | 1152 | unsigned long *lru_size; |
3f58a829 MK |
1153 | |
1154 | if (mem_cgroup_disabled()) | |
1155 | return; | |
1156 | ||
fa9add64 HD |
1157 | mz = container_of(lruvec, struct mem_cgroup_per_zone, lruvec); |
1158 | lru_size = mz->lru_size + lru; | |
1159 | *lru_size += nr_pages; | |
1160 | VM_BUG_ON((long)(*lru_size) < 0); | |
08e552c6 | 1161 | } |
544122e5 | 1162 | |
3e92041d | 1163 | /* |
c0ff4b85 | 1164 | * Checks whether given mem is same or in the root_mem_cgroup's |
3e92041d MH |
1165 | * hierarchy subtree |
1166 | */ | |
c3ac9a8a JW |
1167 | bool __mem_cgroup_same_or_subtree(const struct mem_cgroup *root_memcg, |
1168 | struct mem_cgroup *memcg) | |
3e92041d | 1169 | { |
91c63734 JW |
1170 | if (root_memcg == memcg) |
1171 | return true; | |
3a981f48 | 1172 | if (!root_memcg->use_hierarchy || !memcg) |
91c63734 | 1173 | return false; |
c3ac9a8a JW |
1174 | return css_is_ancestor(&memcg->css, &root_memcg->css); |
1175 | } | |
1176 | ||
1177 | static bool mem_cgroup_same_or_subtree(const struct mem_cgroup *root_memcg, | |
1178 | struct mem_cgroup *memcg) | |
1179 | { | |
1180 | bool ret; | |
1181 | ||
91c63734 | 1182 | rcu_read_lock(); |
c3ac9a8a | 1183 | ret = __mem_cgroup_same_or_subtree(root_memcg, memcg); |
91c63734 JW |
1184 | rcu_read_unlock(); |
1185 | return ret; | |
3e92041d MH |
1186 | } |
1187 | ||
c0ff4b85 | 1188 | int task_in_mem_cgroup(struct task_struct *task, const struct mem_cgroup *memcg) |
4c4a2214 DR |
1189 | { |
1190 | int ret; | |
0b7f569e | 1191 | struct mem_cgroup *curr = NULL; |
158e0a2d | 1192 | struct task_struct *p; |
4c4a2214 | 1193 | |
158e0a2d | 1194 | p = find_lock_task_mm(task); |
de077d22 DR |
1195 | if (p) { |
1196 | curr = try_get_mem_cgroup_from_mm(p->mm); | |
1197 | task_unlock(p); | |
1198 | } else { | |
1199 | /* | |
1200 | * All threads may have already detached their mm's, but the oom | |
1201 | * killer still needs to detect if they have already been oom | |
1202 | * killed to prevent needlessly killing additional tasks. | |
1203 | */ | |
1204 | task_lock(task); | |
1205 | curr = mem_cgroup_from_task(task); | |
1206 | if (curr) | |
1207 | css_get(&curr->css); | |
1208 | task_unlock(task); | |
1209 | } | |
0b7f569e KH |
1210 | if (!curr) |
1211 | return 0; | |
d31f56db | 1212 | /* |
c0ff4b85 | 1213 | * We should check use_hierarchy of "memcg" not "curr". Because checking |
d31f56db | 1214 | * use_hierarchy of "curr" here make this function true if hierarchy is |
c0ff4b85 R |
1215 | * enabled in "curr" and "curr" is a child of "memcg" in *cgroup* |
1216 | * hierarchy(even if use_hierarchy is disabled in "memcg"). | |
d31f56db | 1217 | */ |
c0ff4b85 | 1218 | ret = mem_cgroup_same_or_subtree(memcg, curr); |
0b7f569e | 1219 | css_put(&curr->css); |
4c4a2214 DR |
1220 | return ret; |
1221 | } | |
1222 | ||
c56d5c7d | 1223 | int mem_cgroup_inactive_anon_is_low(struct lruvec *lruvec) |
14797e23 | 1224 | { |
9b272977 | 1225 | unsigned long inactive_ratio; |
14797e23 | 1226 | unsigned long inactive; |
9b272977 | 1227 | unsigned long active; |
c772be93 | 1228 | unsigned long gb; |
14797e23 | 1229 | |
4d7dcca2 HD |
1230 | inactive = mem_cgroup_get_lru_size(lruvec, LRU_INACTIVE_ANON); |
1231 | active = mem_cgroup_get_lru_size(lruvec, LRU_ACTIVE_ANON); | |
14797e23 | 1232 | |
c772be93 KM |
1233 | gb = (inactive + active) >> (30 - PAGE_SHIFT); |
1234 | if (gb) | |
1235 | inactive_ratio = int_sqrt(10 * gb); | |
1236 | else | |
1237 | inactive_ratio = 1; | |
1238 | ||
9b272977 | 1239 | return inactive * inactive_ratio < active; |
14797e23 KM |
1240 | } |
1241 | ||
c56d5c7d | 1242 | int mem_cgroup_inactive_file_is_low(struct lruvec *lruvec) |
56e49d21 RR |
1243 | { |
1244 | unsigned long active; | |
1245 | unsigned long inactive; | |
1246 | ||
4d7dcca2 HD |
1247 | inactive = mem_cgroup_get_lru_size(lruvec, LRU_INACTIVE_FILE); |
1248 | active = mem_cgroup_get_lru_size(lruvec, LRU_ACTIVE_FILE); | |
56e49d21 RR |
1249 | |
1250 | return (active > inactive); | |
1251 | } | |
1252 | ||
6d61ef40 BS |
1253 | #define mem_cgroup_from_res_counter(counter, member) \ |
1254 | container_of(counter, struct mem_cgroup, member) | |
1255 | ||
19942822 | 1256 | /** |
9d11ea9f | 1257 | * mem_cgroup_margin - calculate chargeable space of a memory cgroup |
dad7557e | 1258 | * @memcg: the memory cgroup |
19942822 | 1259 | * |
9d11ea9f | 1260 | * Returns the maximum amount of memory @mem can be charged with, in |
7ec99d62 | 1261 | * pages. |
19942822 | 1262 | */ |
c0ff4b85 | 1263 | static unsigned long mem_cgroup_margin(struct mem_cgroup *memcg) |
19942822 | 1264 | { |
9d11ea9f JW |
1265 | unsigned long long margin; |
1266 | ||
c0ff4b85 | 1267 | margin = res_counter_margin(&memcg->res); |
9d11ea9f | 1268 | if (do_swap_account) |
c0ff4b85 | 1269 | margin = min(margin, res_counter_margin(&memcg->memsw)); |
7ec99d62 | 1270 | return margin >> PAGE_SHIFT; |
19942822 JW |
1271 | } |
1272 | ||
1f4c025b | 1273 | int mem_cgroup_swappiness(struct mem_cgroup *memcg) |
a7885eb8 KM |
1274 | { |
1275 | struct cgroup *cgrp = memcg->css.cgroup; | |
a7885eb8 KM |
1276 | |
1277 | /* root ? */ | |
1278 | if (cgrp->parent == NULL) | |
1279 | return vm_swappiness; | |
1280 | ||
bf1ff263 | 1281 | return memcg->swappiness; |
a7885eb8 KM |
1282 | } |
1283 | ||
619d094b KH |
1284 | /* |
1285 | * memcg->moving_account is used for checking possibility that some thread is | |
1286 | * calling move_account(). When a thread on CPU-A starts moving pages under | |
1287 | * a memcg, other threads should check memcg->moving_account under | |
1288 | * rcu_read_lock(), like this: | |
1289 | * | |
1290 | * CPU-A CPU-B | |
1291 | * rcu_read_lock() | |
1292 | * memcg->moving_account+1 if (memcg->mocing_account) | |
1293 | * take heavy locks. | |
1294 | * synchronize_rcu() update something. | |
1295 | * rcu_read_unlock() | |
1296 | * start move here. | |
1297 | */ | |
4331f7d3 KH |
1298 | |
1299 | /* for quick checking without looking up memcg */ | |
1300 | atomic_t memcg_moving __read_mostly; | |
1301 | ||
c0ff4b85 | 1302 | static void mem_cgroup_start_move(struct mem_cgroup *memcg) |
32047e2a | 1303 | { |
4331f7d3 | 1304 | atomic_inc(&memcg_moving); |
619d094b | 1305 | atomic_inc(&memcg->moving_account); |
32047e2a KH |
1306 | synchronize_rcu(); |
1307 | } | |
1308 | ||
c0ff4b85 | 1309 | static void mem_cgroup_end_move(struct mem_cgroup *memcg) |
32047e2a | 1310 | { |
619d094b KH |
1311 | /* |
1312 | * Now, mem_cgroup_clear_mc() may call this function with NULL. | |
1313 | * We check NULL in callee rather than caller. | |
1314 | */ | |
4331f7d3 KH |
1315 | if (memcg) { |
1316 | atomic_dec(&memcg_moving); | |
619d094b | 1317 | atomic_dec(&memcg->moving_account); |
4331f7d3 | 1318 | } |
32047e2a | 1319 | } |
619d094b | 1320 | |
32047e2a KH |
1321 | /* |
1322 | * 2 routines for checking "mem" is under move_account() or not. | |
1323 | * | |
13fd1dd9 AM |
1324 | * mem_cgroup_stolen() - checking whether a cgroup is mc.from or not. This |
1325 | * is used for avoiding races in accounting. If true, | |
32047e2a KH |
1326 | * pc->mem_cgroup may be overwritten. |
1327 | * | |
1328 | * mem_cgroup_under_move() - checking a cgroup is mc.from or mc.to or | |
1329 | * under hierarchy of moving cgroups. This is for | |
1330 | * waiting at hith-memory prressure caused by "move". | |
1331 | */ | |
1332 | ||
13fd1dd9 | 1333 | static bool mem_cgroup_stolen(struct mem_cgroup *memcg) |
32047e2a KH |
1334 | { |
1335 | VM_BUG_ON(!rcu_read_lock_held()); | |
619d094b | 1336 | return atomic_read(&memcg->moving_account) > 0; |
32047e2a | 1337 | } |
4b534334 | 1338 | |
c0ff4b85 | 1339 | static bool mem_cgroup_under_move(struct mem_cgroup *memcg) |
4b534334 | 1340 | { |
2bd9bb20 KH |
1341 | struct mem_cgroup *from; |
1342 | struct mem_cgroup *to; | |
4b534334 | 1343 | bool ret = false; |
2bd9bb20 KH |
1344 | /* |
1345 | * Unlike task_move routines, we access mc.to, mc.from not under | |
1346 | * mutual exclusion by cgroup_mutex. Here, we take spinlock instead. | |
1347 | */ | |
1348 | spin_lock(&mc.lock); | |
1349 | from = mc.from; | |
1350 | to = mc.to; | |
1351 | if (!from) | |
1352 | goto unlock; | |
3e92041d | 1353 | |
c0ff4b85 R |
1354 | ret = mem_cgroup_same_or_subtree(memcg, from) |
1355 | || mem_cgroup_same_or_subtree(memcg, to); | |
2bd9bb20 KH |
1356 | unlock: |
1357 | spin_unlock(&mc.lock); | |
4b534334 KH |
1358 | return ret; |
1359 | } | |
1360 | ||
c0ff4b85 | 1361 | static bool mem_cgroup_wait_acct_move(struct mem_cgroup *memcg) |
4b534334 KH |
1362 | { |
1363 | if (mc.moving_task && current != mc.moving_task) { | |
c0ff4b85 | 1364 | if (mem_cgroup_under_move(memcg)) { |
4b534334 KH |
1365 | DEFINE_WAIT(wait); |
1366 | prepare_to_wait(&mc.waitq, &wait, TASK_INTERRUPTIBLE); | |
1367 | /* moving charge context might have finished. */ | |
1368 | if (mc.moving_task) | |
1369 | schedule(); | |
1370 | finish_wait(&mc.waitq, &wait); | |
1371 | return true; | |
1372 | } | |
1373 | } | |
1374 | return false; | |
1375 | } | |
1376 | ||
312734c0 KH |
1377 | /* |
1378 | * Take this lock when | |
1379 | * - a code tries to modify page's memcg while it's USED. | |
1380 | * - a code tries to modify page state accounting in a memcg. | |
13fd1dd9 | 1381 | * see mem_cgroup_stolen(), too. |
312734c0 KH |
1382 | */ |
1383 | static void move_lock_mem_cgroup(struct mem_cgroup *memcg, | |
1384 | unsigned long *flags) | |
1385 | { | |
1386 | spin_lock_irqsave(&memcg->move_lock, *flags); | |
1387 | } | |
1388 | ||
1389 | static void move_unlock_mem_cgroup(struct mem_cgroup *memcg, | |
1390 | unsigned long *flags) | |
1391 | { | |
1392 | spin_unlock_irqrestore(&memcg->move_lock, *flags); | |
1393 | } | |
1394 | ||
e222432b | 1395 | /** |
6a6135b6 | 1396 | * mem_cgroup_print_oom_info: Called from OOM with tasklist_lock held in read mode. |
e222432b BS |
1397 | * @memcg: The memory cgroup that went over limit |
1398 | * @p: Task that is going to be killed | |
1399 | * | |
1400 | * NOTE: @memcg and @p's mem_cgroup can be different when hierarchy is | |
1401 | * enabled | |
1402 | */ | |
1403 | void mem_cgroup_print_oom_info(struct mem_cgroup *memcg, struct task_struct *p) | |
1404 | { | |
1405 | struct cgroup *task_cgrp; | |
1406 | struct cgroup *mem_cgrp; | |
1407 | /* | |
1408 | * Need a buffer in BSS, can't rely on allocations. The code relies | |
1409 | * on the assumption that OOM is serialized for memory controller. | |
1410 | * If this assumption is broken, revisit this code. | |
1411 | */ | |
1412 | static char memcg_name[PATH_MAX]; | |
1413 | int ret; | |
1414 | ||
d31f56db | 1415 | if (!memcg || !p) |
e222432b BS |
1416 | return; |
1417 | ||
e222432b BS |
1418 | rcu_read_lock(); |
1419 | ||
1420 | mem_cgrp = memcg->css.cgroup; | |
1421 | task_cgrp = task_cgroup(p, mem_cgroup_subsys_id); | |
1422 | ||
1423 | ret = cgroup_path(task_cgrp, memcg_name, PATH_MAX); | |
1424 | if (ret < 0) { | |
1425 | /* | |
1426 | * Unfortunately, we are unable to convert to a useful name | |
1427 | * But we'll still print out the usage information | |
1428 | */ | |
1429 | rcu_read_unlock(); | |
1430 | goto done; | |
1431 | } | |
1432 | rcu_read_unlock(); | |
1433 | ||
1434 | printk(KERN_INFO "Task in %s killed", memcg_name); | |
1435 | ||
1436 | rcu_read_lock(); | |
1437 | ret = cgroup_path(mem_cgrp, memcg_name, PATH_MAX); | |
1438 | if (ret < 0) { | |
1439 | rcu_read_unlock(); | |
1440 | goto done; | |
1441 | } | |
1442 | rcu_read_unlock(); | |
1443 | ||
1444 | /* | |
1445 | * Continues from above, so we don't need an KERN_ level | |
1446 | */ | |
1447 | printk(KERN_CONT " as a result of limit of %s\n", memcg_name); | |
1448 | done: | |
1449 | ||
1450 | printk(KERN_INFO "memory: usage %llukB, limit %llukB, failcnt %llu\n", | |
1451 | res_counter_read_u64(&memcg->res, RES_USAGE) >> 10, | |
1452 | res_counter_read_u64(&memcg->res, RES_LIMIT) >> 10, | |
1453 | res_counter_read_u64(&memcg->res, RES_FAILCNT)); | |
1454 | printk(KERN_INFO "memory+swap: usage %llukB, limit %llukB, " | |
1455 | "failcnt %llu\n", | |
1456 | res_counter_read_u64(&memcg->memsw, RES_USAGE) >> 10, | |
1457 | res_counter_read_u64(&memcg->memsw, RES_LIMIT) >> 10, | |
1458 | res_counter_read_u64(&memcg->memsw, RES_FAILCNT)); | |
1459 | } | |
1460 | ||
81d39c20 KH |
1461 | /* |
1462 | * This function returns the number of memcg under hierarchy tree. Returns | |
1463 | * 1(self count) if no children. | |
1464 | */ | |
c0ff4b85 | 1465 | static int mem_cgroup_count_children(struct mem_cgroup *memcg) |
81d39c20 KH |
1466 | { |
1467 | int num = 0; | |
7d74b06f KH |
1468 | struct mem_cgroup *iter; |
1469 | ||
c0ff4b85 | 1470 | for_each_mem_cgroup_tree(iter, memcg) |
7d74b06f | 1471 | num++; |
81d39c20 KH |
1472 | return num; |
1473 | } | |
1474 | ||
a63d83f4 DR |
1475 | /* |
1476 | * Return the memory (and swap, if configured) limit for a memcg. | |
1477 | */ | |
9cbb78bb | 1478 | static u64 mem_cgroup_get_limit(struct mem_cgroup *memcg) |
a63d83f4 DR |
1479 | { |
1480 | u64 limit; | |
a63d83f4 | 1481 | |
f3e8eb70 | 1482 | limit = res_counter_read_u64(&memcg->res, RES_LIMIT); |
f3e8eb70 | 1483 | |
a63d83f4 | 1484 | /* |
9a5a8f19 | 1485 | * Do not consider swap space if we cannot swap due to swappiness |
a63d83f4 | 1486 | */ |
9a5a8f19 MH |
1487 | if (mem_cgroup_swappiness(memcg)) { |
1488 | u64 memsw; | |
1489 | ||
1490 | limit += total_swap_pages << PAGE_SHIFT; | |
1491 | memsw = res_counter_read_u64(&memcg->memsw, RES_LIMIT); | |
1492 | ||
1493 | /* | |
1494 | * If memsw is finite and limits the amount of swap space | |
1495 | * available to this memcg, return that limit. | |
1496 | */ | |
1497 | limit = min(limit, memsw); | |
1498 | } | |
1499 | ||
1500 | return limit; | |
a63d83f4 DR |
1501 | } |
1502 | ||
19965460 DR |
1503 | static void mem_cgroup_out_of_memory(struct mem_cgroup *memcg, gfp_t gfp_mask, |
1504 | int order) | |
9cbb78bb DR |
1505 | { |
1506 | struct mem_cgroup *iter; | |
1507 | unsigned long chosen_points = 0; | |
1508 | unsigned long totalpages; | |
1509 | unsigned int points = 0; | |
1510 | struct task_struct *chosen = NULL; | |
1511 | ||
876aafbf DR |
1512 | /* |
1513 | * If current has a pending SIGKILL, then automatically select it. The | |
1514 | * goal is to allow it to allocate so that it may quickly exit and free | |
1515 | * its memory. | |
1516 | */ | |
1517 | if (fatal_signal_pending(current)) { | |
1518 | set_thread_flag(TIF_MEMDIE); | |
1519 | return; | |
1520 | } | |
1521 | ||
1522 | check_panic_on_oom(CONSTRAINT_MEMCG, gfp_mask, order, NULL); | |
9cbb78bb DR |
1523 | totalpages = mem_cgroup_get_limit(memcg) >> PAGE_SHIFT ? : 1; |
1524 | for_each_mem_cgroup_tree(iter, memcg) { | |
1525 | struct cgroup *cgroup = iter->css.cgroup; | |
1526 | struct cgroup_iter it; | |
1527 | struct task_struct *task; | |
1528 | ||
1529 | cgroup_iter_start(cgroup, &it); | |
1530 | while ((task = cgroup_iter_next(cgroup, &it))) { | |
1531 | switch (oom_scan_process_thread(task, totalpages, NULL, | |
1532 | false)) { | |
1533 | case OOM_SCAN_SELECT: | |
1534 | if (chosen) | |
1535 | put_task_struct(chosen); | |
1536 | chosen = task; | |
1537 | chosen_points = ULONG_MAX; | |
1538 | get_task_struct(chosen); | |
1539 | /* fall through */ | |
1540 | case OOM_SCAN_CONTINUE: | |
1541 | continue; | |
1542 | case OOM_SCAN_ABORT: | |
1543 | cgroup_iter_end(cgroup, &it); | |
1544 | mem_cgroup_iter_break(memcg, iter); | |
1545 | if (chosen) | |
1546 | put_task_struct(chosen); | |
1547 | return; | |
1548 | case OOM_SCAN_OK: | |
1549 | break; | |
1550 | }; | |
1551 | points = oom_badness(task, memcg, NULL, totalpages); | |
1552 | if (points > chosen_points) { | |
1553 | if (chosen) | |
1554 | put_task_struct(chosen); | |
1555 | chosen = task; | |
1556 | chosen_points = points; | |
1557 | get_task_struct(chosen); | |
1558 | } | |
1559 | } | |
1560 | cgroup_iter_end(cgroup, &it); | |
1561 | } | |
1562 | ||
1563 | if (!chosen) | |
1564 | return; | |
1565 | points = chosen_points * 1000 / totalpages; | |
9cbb78bb DR |
1566 | oom_kill_process(chosen, gfp_mask, order, points, totalpages, memcg, |
1567 | NULL, "Memory cgroup out of memory"); | |
9cbb78bb DR |
1568 | } |
1569 | ||
5660048c JW |
1570 | static unsigned long mem_cgroup_reclaim(struct mem_cgroup *memcg, |
1571 | gfp_t gfp_mask, | |
1572 | unsigned long flags) | |
1573 | { | |
1574 | unsigned long total = 0; | |
1575 | bool noswap = false; | |
1576 | int loop; | |
1577 | ||
1578 | if (flags & MEM_CGROUP_RECLAIM_NOSWAP) | |
1579 | noswap = true; | |
1580 | if (!(flags & MEM_CGROUP_RECLAIM_SHRINK) && memcg->memsw_is_minimum) | |
1581 | noswap = true; | |
1582 | ||
1583 | for (loop = 0; loop < MEM_CGROUP_MAX_RECLAIM_LOOPS; loop++) { | |
1584 | if (loop) | |
1585 | drain_all_stock_async(memcg); | |
1586 | total += try_to_free_mem_cgroup_pages(memcg, gfp_mask, noswap); | |
1587 | /* | |
1588 | * Allow limit shrinkers, which are triggered directly | |
1589 | * by userspace, to catch signals and stop reclaim | |
1590 | * after minimal progress, regardless of the margin. | |
1591 | */ | |
1592 | if (total && (flags & MEM_CGROUP_RECLAIM_SHRINK)) | |
1593 | break; | |
1594 | if (mem_cgroup_margin(memcg)) | |
1595 | break; | |
1596 | /* | |
1597 | * If nothing was reclaimed after two attempts, there | |
1598 | * may be no reclaimable pages in this hierarchy. | |
1599 | */ | |
1600 | if (loop && !total) | |
1601 | break; | |
1602 | } | |
1603 | return total; | |
1604 | } | |
1605 | ||
4d0c066d KH |
1606 | /** |
1607 | * test_mem_cgroup_node_reclaimable | |
dad7557e | 1608 | * @memcg: the target memcg |
4d0c066d KH |
1609 | * @nid: the node ID to be checked. |
1610 | * @noswap : specify true here if the user wants flle only information. | |
1611 | * | |
1612 | * This function returns whether the specified memcg contains any | |
1613 | * reclaimable pages on a node. Returns true if there are any reclaimable | |
1614 | * pages in the node. | |
1615 | */ | |
c0ff4b85 | 1616 | static bool test_mem_cgroup_node_reclaimable(struct mem_cgroup *memcg, |
4d0c066d KH |
1617 | int nid, bool noswap) |
1618 | { | |
c0ff4b85 | 1619 | if (mem_cgroup_node_nr_lru_pages(memcg, nid, LRU_ALL_FILE)) |
4d0c066d KH |
1620 | return true; |
1621 | if (noswap || !total_swap_pages) | |
1622 | return false; | |
c0ff4b85 | 1623 | if (mem_cgroup_node_nr_lru_pages(memcg, nid, LRU_ALL_ANON)) |
4d0c066d KH |
1624 | return true; |
1625 | return false; | |
1626 | ||
1627 | } | |
889976db YH |
1628 | #if MAX_NUMNODES > 1 |
1629 | ||
1630 | /* | |
1631 | * Always updating the nodemask is not very good - even if we have an empty | |
1632 | * list or the wrong list here, we can start from some node and traverse all | |
1633 | * nodes based on the zonelist. So update the list loosely once per 10 secs. | |
1634 | * | |
1635 | */ | |
c0ff4b85 | 1636 | static void mem_cgroup_may_update_nodemask(struct mem_cgroup *memcg) |
889976db YH |
1637 | { |
1638 | int nid; | |
453a9bf3 KH |
1639 | /* |
1640 | * numainfo_events > 0 means there was at least NUMAINFO_EVENTS_TARGET | |
1641 | * pagein/pageout changes since the last update. | |
1642 | */ | |
c0ff4b85 | 1643 | if (!atomic_read(&memcg->numainfo_events)) |
453a9bf3 | 1644 | return; |
c0ff4b85 | 1645 | if (atomic_inc_return(&memcg->numainfo_updating) > 1) |
889976db YH |
1646 | return; |
1647 | ||
889976db | 1648 | /* make a nodemask where this memcg uses memory from */ |
31aaea4a | 1649 | memcg->scan_nodes = node_states[N_MEMORY]; |
889976db | 1650 | |
31aaea4a | 1651 | for_each_node_mask(nid, node_states[N_MEMORY]) { |
889976db | 1652 | |
c0ff4b85 R |
1653 | if (!test_mem_cgroup_node_reclaimable(memcg, nid, false)) |
1654 | node_clear(nid, memcg->scan_nodes); | |
889976db | 1655 | } |
453a9bf3 | 1656 | |
c0ff4b85 R |
1657 | atomic_set(&memcg->numainfo_events, 0); |
1658 | atomic_set(&memcg->numainfo_updating, 0); | |
889976db YH |
1659 | } |
1660 | ||
1661 | /* | |
1662 | * Selecting a node where we start reclaim from. Because what we need is just | |
1663 | * reducing usage counter, start from anywhere is O,K. Considering | |
1664 | * memory reclaim from current node, there are pros. and cons. | |
1665 | * | |
1666 | * Freeing memory from current node means freeing memory from a node which | |
1667 | * we'll use or we've used. So, it may make LRU bad. And if several threads | |
1668 | * hit limits, it will see a contention on a node. But freeing from remote | |
1669 | * node means more costs for memory reclaim because of memory latency. | |
1670 | * | |
1671 | * Now, we use round-robin. Better algorithm is welcomed. | |
1672 | */ | |
c0ff4b85 | 1673 | int mem_cgroup_select_victim_node(struct mem_cgroup *memcg) |
889976db YH |
1674 | { |
1675 | int node; | |
1676 | ||
c0ff4b85 R |
1677 | mem_cgroup_may_update_nodemask(memcg); |
1678 | node = memcg->last_scanned_node; | |
889976db | 1679 | |
c0ff4b85 | 1680 | node = next_node(node, memcg->scan_nodes); |
889976db | 1681 | if (node == MAX_NUMNODES) |
c0ff4b85 | 1682 | node = first_node(memcg->scan_nodes); |
889976db YH |
1683 | /* |
1684 | * We call this when we hit limit, not when pages are added to LRU. | |
1685 | * No LRU may hold pages because all pages are UNEVICTABLE or | |
1686 | * memcg is too small and all pages are not on LRU. In that case, | |
1687 | * we use curret node. | |
1688 | */ | |
1689 | if (unlikely(node == MAX_NUMNODES)) | |
1690 | node = numa_node_id(); | |
1691 | ||
c0ff4b85 | 1692 | memcg->last_scanned_node = node; |
889976db YH |
1693 | return node; |
1694 | } | |
1695 | ||
4d0c066d KH |
1696 | /* |
1697 | * Check all nodes whether it contains reclaimable pages or not. | |
1698 | * For quick scan, we make use of scan_nodes. This will allow us to skip | |
1699 | * unused nodes. But scan_nodes is lazily updated and may not cotain | |
1700 | * enough new information. We need to do double check. | |
1701 | */ | |
6bbda35c | 1702 | static bool mem_cgroup_reclaimable(struct mem_cgroup *memcg, bool noswap) |
4d0c066d KH |
1703 | { |
1704 | int nid; | |
1705 | ||
1706 | /* | |
1707 | * quick check...making use of scan_node. | |
1708 | * We can skip unused nodes. | |
1709 | */ | |
c0ff4b85 R |
1710 | if (!nodes_empty(memcg->scan_nodes)) { |
1711 | for (nid = first_node(memcg->scan_nodes); | |
4d0c066d | 1712 | nid < MAX_NUMNODES; |
c0ff4b85 | 1713 | nid = next_node(nid, memcg->scan_nodes)) { |
4d0c066d | 1714 | |
c0ff4b85 | 1715 | if (test_mem_cgroup_node_reclaimable(memcg, nid, noswap)) |
4d0c066d KH |
1716 | return true; |
1717 | } | |
1718 | } | |
1719 | /* | |
1720 | * Check rest of nodes. | |
1721 | */ | |
31aaea4a | 1722 | for_each_node_state(nid, N_MEMORY) { |
c0ff4b85 | 1723 | if (node_isset(nid, memcg->scan_nodes)) |
4d0c066d | 1724 | continue; |
c0ff4b85 | 1725 | if (test_mem_cgroup_node_reclaimable(memcg, nid, noswap)) |
4d0c066d KH |
1726 | return true; |
1727 | } | |
1728 | return false; | |
1729 | } | |
1730 | ||
889976db | 1731 | #else |
c0ff4b85 | 1732 | int mem_cgroup_select_victim_node(struct mem_cgroup *memcg) |
889976db YH |
1733 | { |
1734 | return 0; | |
1735 | } | |
4d0c066d | 1736 | |
6bbda35c | 1737 | static bool mem_cgroup_reclaimable(struct mem_cgroup *memcg, bool noswap) |
4d0c066d | 1738 | { |
c0ff4b85 | 1739 | return test_mem_cgroup_node_reclaimable(memcg, 0, noswap); |
4d0c066d | 1740 | } |
889976db YH |
1741 | #endif |
1742 | ||
5660048c JW |
1743 | static int mem_cgroup_soft_reclaim(struct mem_cgroup *root_memcg, |
1744 | struct zone *zone, | |
1745 | gfp_t gfp_mask, | |
1746 | unsigned long *total_scanned) | |
6d61ef40 | 1747 | { |
9f3a0d09 | 1748 | struct mem_cgroup *victim = NULL; |
5660048c | 1749 | int total = 0; |
04046e1a | 1750 | int loop = 0; |
9d11ea9f | 1751 | unsigned long excess; |
185efc0f | 1752 | unsigned long nr_scanned; |
527a5ec9 JW |
1753 | struct mem_cgroup_reclaim_cookie reclaim = { |
1754 | .zone = zone, | |
1755 | .priority = 0, | |
1756 | }; | |
9d11ea9f | 1757 | |
c0ff4b85 | 1758 | excess = res_counter_soft_limit_excess(&root_memcg->res) >> PAGE_SHIFT; |
04046e1a | 1759 | |
4e416953 | 1760 | while (1) { |
527a5ec9 | 1761 | victim = mem_cgroup_iter(root_memcg, victim, &reclaim); |
9f3a0d09 | 1762 | if (!victim) { |
04046e1a | 1763 | loop++; |
4e416953 BS |
1764 | if (loop >= 2) { |
1765 | /* | |
1766 | * If we have not been able to reclaim | |
1767 | * anything, it might because there are | |
1768 | * no reclaimable pages under this hierarchy | |
1769 | */ | |
5660048c | 1770 | if (!total) |
4e416953 | 1771 | break; |
4e416953 | 1772 | /* |
25985edc | 1773 | * We want to do more targeted reclaim. |
4e416953 BS |
1774 | * excess >> 2 is not to excessive so as to |
1775 | * reclaim too much, nor too less that we keep | |
1776 | * coming back to reclaim from this cgroup | |
1777 | */ | |
1778 | if (total >= (excess >> 2) || | |
9f3a0d09 | 1779 | (loop > MEM_CGROUP_MAX_RECLAIM_LOOPS)) |
4e416953 | 1780 | break; |
4e416953 | 1781 | } |
9f3a0d09 | 1782 | continue; |
4e416953 | 1783 | } |
5660048c | 1784 | if (!mem_cgroup_reclaimable(victim, false)) |
6d61ef40 | 1785 | continue; |
5660048c JW |
1786 | total += mem_cgroup_shrink_node_zone(victim, gfp_mask, false, |
1787 | zone, &nr_scanned); | |
1788 | *total_scanned += nr_scanned; | |
1789 | if (!res_counter_soft_limit_excess(&root_memcg->res)) | |
9f3a0d09 | 1790 | break; |
6d61ef40 | 1791 | } |
9f3a0d09 | 1792 | mem_cgroup_iter_break(root_memcg, victim); |
04046e1a | 1793 | return total; |
6d61ef40 BS |
1794 | } |
1795 | ||
867578cb KH |
1796 | /* |
1797 | * Check OOM-Killer is already running under our hierarchy. | |
1798 | * If someone is running, return false. | |
1af8efe9 | 1799 | * Has to be called with memcg_oom_lock |
867578cb | 1800 | */ |
c0ff4b85 | 1801 | static bool mem_cgroup_oom_lock(struct mem_cgroup *memcg) |
867578cb | 1802 | { |
79dfdacc | 1803 | struct mem_cgroup *iter, *failed = NULL; |
a636b327 | 1804 | |
9f3a0d09 | 1805 | for_each_mem_cgroup_tree(iter, memcg) { |
23751be0 | 1806 | if (iter->oom_lock) { |
79dfdacc MH |
1807 | /* |
1808 | * this subtree of our hierarchy is already locked | |
1809 | * so we cannot give a lock. | |
1810 | */ | |
79dfdacc | 1811 | failed = iter; |
9f3a0d09 JW |
1812 | mem_cgroup_iter_break(memcg, iter); |
1813 | break; | |
23751be0 JW |
1814 | } else |
1815 | iter->oom_lock = true; | |
7d74b06f | 1816 | } |
867578cb | 1817 | |
79dfdacc | 1818 | if (!failed) |
23751be0 | 1819 | return true; |
79dfdacc MH |
1820 | |
1821 | /* | |
1822 | * OK, we failed to lock the whole subtree so we have to clean up | |
1823 | * what we set up to the failing subtree | |
1824 | */ | |
9f3a0d09 | 1825 | for_each_mem_cgroup_tree(iter, memcg) { |
79dfdacc | 1826 | if (iter == failed) { |
9f3a0d09 JW |
1827 | mem_cgroup_iter_break(memcg, iter); |
1828 | break; | |
79dfdacc MH |
1829 | } |
1830 | iter->oom_lock = false; | |
1831 | } | |
23751be0 | 1832 | return false; |
a636b327 | 1833 | } |
0b7f569e | 1834 | |
79dfdacc | 1835 | /* |
1af8efe9 | 1836 | * Has to be called with memcg_oom_lock |
79dfdacc | 1837 | */ |
c0ff4b85 | 1838 | static int mem_cgroup_oom_unlock(struct mem_cgroup *memcg) |
0b7f569e | 1839 | { |
7d74b06f KH |
1840 | struct mem_cgroup *iter; |
1841 | ||
c0ff4b85 | 1842 | for_each_mem_cgroup_tree(iter, memcg) |
79dfdacc MH |
1843 | iter->oom_lock = false; |
1844 | return 0; | |
1845 | } | |
1846 | ||
c0ff4b85 | 1847 | static void mem_cgroup_mark_under_oom(struct mem_cgroup *memcg) |
79dfdacc MH |
1848 | { |
1849 | struct mem_cgroup *iter; | |
1850 | ||
c0ff4b85 | 1851 | for_each_mem_cgroup_tree(iter, memcg) |
79dfdacc MH |
1852 | atomic_inc(&iter->under_oom); |
1853 | } | |
1854 | ||
c0ff4b85 | 1855 | static void mem_cgroup_unmark_under_oom(struct mem_cgroup *memcg) |
79dfdacc MH |
1856 | { |
1857 | struct mem_cgroup *iter; | |
1858 | ||
867578cb KH |
1859 | /* |
1860 | * When a new child is created while the hierarchy is under oom, | |
1861 | * mem_cgroup_oom_lock() may not be called. We have to use | |
1862 | * atomic_add_unless() here. | |
1863 | */ | |
c0ff4b85 | 1864 | for_each_mem_cgroup_tree(iter, memcg) |
79dfdacc | 1865 | atomic_add_unless(&iter->under_oom, -1, 0); |
0b7f569e KH |
1866 | } |
1867 | ||
1af8efe9 | 1868 | static DEFINE_SPINLOCK(memcg_oom_lock); |
867578cb KH |
1869 | static DECLARE_WAIT_QUEUE_HEAD(memcg_oom_waitq); |
1870 | ||
dc98df5a | 1871 | struct oom_wait_info { |
d79154bb | 1872 | struct mem_cgroup *memcg; |
dc98df5a KH |
1873 | wait_queue_t wait; |
1874 | }; | |
1875 | ||
1876 | static int memcg_oom_wake_function(wait_queue_t *wait, | |
1877 | unsigned mode, int sync, void *arg) | |
1878 | { | |
d79154bb HD |
1879 | struct mem_cgroup *wake_memcg = (struct mem_cgroup *)arg; |
1880 | struct mem_cgroup *oom_wait_memcg; | |
dc98df5a KH |
1881 | struct oom_wait_info *oom_wait_info; |
1882 | ||
1883 | oom_wait_info = container_of(wait, struct oom_wait_info, wait); | |
d79154bb | 1884 | oom_wait_memcg = oom_wait_info->memcg; |
dc98df5a | 1885 | |
dc98df5a | 1886 | /* |
d79154bb | 1887 | * Both of oom_wait_info->memcg and wake_memcg are stable under us. |
dc98df5a KH |
1888 | * Then we can use css_is_ancestor without taking care of RCU. |
1889 | */ | |
c0ff4b85 R |
1890 | if (!mem_cgroup_same_or_subtree(oom_wait_memcg, wake_memcg) |
1891 | && !mem_cgroup_same_or_subtree(wake_memcg, oom_wait_memcg)) | |
dc98df5a | 1892 | return 0; |
dc98df5a KH |
1893 | return autoremove_wake_function(wait, mode, sync, arg); |
1894 | } | |
1895 | ||
c0ff4b85 | 1896 | static void memcg_wakeup_oom(struct mem_cgroup *memcg) |
dc98df5a | 1897 | { |
c0ff4b85 R |
1898 | /* for filtering, pass "memcg" as argument. */ |
1899 | __wake_up(&memcg_oom_waitq, TASK_NORMAL, 0, memcg); | |
dc98df5a KH |
1900 | } |
1901 | ||
c0ff4b85 | 1902 | static void memcg_oom_recover(struct mem_cgroup *memcg) |
3c11ecf4 | 1903 | { |
c0ff4b85 R |
1904 | if (memcg && atomic_read(&memcg->under_oom)) |
1905 | memcg_wakeup_oom(memcg); | |
3c11ecf4 KH |
1906 | } |
1907 | ||
867578cb KH |
1908 | /* |
1909 | * try to call OOM killer. returns false if we should exit memory-reclaim loop. | |
1910 | */ | |
6bbda35c KS |
1911 | static bool mem_cgroup_handle_oom(struct mem_cgroup *memcg, gfp_t mask, |
1912 | int order) | |
0b7f569e | 1913 | { |
dc98df5a | 1914 | struct oom_wait_info owait; |
3c11ecf4 | 1915 | bool locked, need_to_kill; |
867578cb | 1916 | |
d79154bb | 1917 | owait.memcg = memcg; |
dc98df5a KH |
1918 | owait.wait.flags = 0; |
1919 | owait.wait.func = memcg_oom_wake_function; | |
1920 | owait.wait.private = current; | |
1921 | INIT_LIST_HEAD(&owait.wait.task_list); | |
3c11ecf4 | 1922 | need_to_kill = true; |
c0ff4b85 | 1923 | mem_cgroup_mark_under_oom(memcg); |
79dfdacc | 1924 | |
c0ff4b85 | 1925 | /* At first, try to OOM lock hierarchy under memcg.*/ |
1af8efe9 | 1926 | spin_lock(&memcg_oom_lock); |
c0ff4b85 | 1927 | locked = mem_cgroup_oom_lock(memcg); |
867578cb KH |
1928 | /* |
1929 | * Even if signal_pending(), we can't quit charge() loop without | |
1930 | * accounting. So, UNINTERRUPTIBLE is appropriate. But SIGKILL | |
1931 | * under OOM is always welcomed, use TASK_KILLABLE here. | |
1932 | */ | |
3c11ecf4 | 1933 | prepare_to_wait(&memcg_oom_waitq, &owait.wait, TASK_KILLABLE); |
c0ff4b85 | 1934 | if (!locked || memcg->oom_kill_disable) |
3c11ecf4 KH |
1935 | need_to_kill = false; |
1936 | if (locked) | |
c0ff4b85 | 1937 | mem_cgroup_oom_notify(memcg); |
1af8efe9 | 1938 | spin_unlock(&memcg_oom_lock); |
867578cb | 1939 | |
3c11ecf4 KH |
1940 | if (need_to_kill) { |
1941 | finish_wait(&memcg_oom_waitq, &owait.wait); | |
e845e199 | 1942 | mem_cgroup_out_of_memory(memcg, mask, order); |
3c11ecf4 | 1943 | } else { |
867578cb | 1944 | schedule(); |
dc98df5a | 1945 | finish_wait(&memcg_oom_waitq, &owait.wait); |
867578cb | 1946 | } |
1af8efe9 | 1947 | spin_lock(&memcg_oom_lock); |
79dfdacc | 1948 | if (locked) |
c0ff4b85 R |
1949 | mem_cgroup_oom_unlock(memcg); |
1950 | memcg_wakeup_oom(memcg); | |
1af8efe9 | 1951 | spin_unlock(&memcg_oom_lock); |
867578cb | 1952 | |
c0ff4b85 | 1953 | mem_cgroup_unmark_under_oom(memcg); |
79dfdacc | 1954 | |
867578cb KH |
1955 | if (test_thread_flag(TIF_MEMDIE) || fatal_signal_pending(current)) |
1956 | return false; | |
1957 | /* Give chance to dying process */ | |
715a5ee8 | 1958 | schedule_timeout_uninterruptible(1); |
867578cb | 1959 | return true; |
0b7f569e KH |
1960 | } |
1961 | ||
d69b042f BS |
1962 | /* |
1963 | * Currently used to update mapped file statistics, but the routine can be | |
1964 | * generalized to update other statistics as well. | |
32047e2a KH |
1965 | * |
1966 | * Notes: Race condition | |
1967 | * | |
1968 | * We usually use page_cgroup_lock() for accessing page_cgroup member but | |
1969 | * it tends to be costly. But considering some conditions, we doesn't need | |
1970 | * to do so _always_. | |
1971 | * | |
1972 | * Considering "charge", lock_page_cgroup() is not required because all | |
1973 | * file-stat operations happen after a page is attached to radix-tree. There | |
1974 | * are no race with "charge". | |
1975 | * | |
1976 | * Considering "uncharge", we know that memcg doesn't clear pc->mem_cgroup | |
1977 | * at "uncharge" intentionally. So, we always see valid pc->mem_cgroup even | |
1978 | * if there are race with "uncharge". Statistics itself is properly handled | |
1979 | * by flags. | |
1980 | * | |
1981 | * Considering "move", this is an only case we see a race. To make the race | |
619d094b KH |
1982 | * small, we check mm->moving_account and detect there are possibility of race |
1983 | * If there is, we take a lock. | |
d69b042f | 1984 | */ |
26174efd | 1985 | |
89c06bd5 KH |
1986 | void __mem_cgroup_begin_update_page_stat(struct page *page, |
1987 | bool *locked, unsigned long *flags) | |
1988 | { | |
1989 | struct mem_cgroup *memcg; | |
1990 | struct page_cgroup *pc; | |
1991 | ||
1992 | pc = lookup_page_cgroup(page); | |
1993 | again: | |
1994 | memcg = pc->mem_cgroup; | |
1995 | if (unlikely(!memcg || !PageCgroupUsed(pc))) | |
1996 | return; | |
1997 | /* | |
1998 | * If this memory cgroup is not under account moving, we don't | |
da92c47d | 1999 | * need to take move_lock_mem_cgroup(). Because we already hold |
89c06bd5 | 2000 | * rcu_read_lock(), any calls to move_account will be delayed until |
13fd1dd9 | 2001 | * rcu_read_unlock() if mem_cgroup_stolen() == true. |
89c06bd5 | 2002 | */ |
13fd1dd9 | 2003 | if (!mem_cgroup_stolen(memcg)) |
89c06bd5 KH |
2004 | return; |
2005 | ||
2006 | move_lock_mem_cgroup(memcg, flags); | |
2007 | if (memcg != pc->mem_cgroup || !PageCgroupUsed(pc)) { | |
2008 | move_unlock_mem_cgroup(memcg, flags); | |
2009 | goto again; | |
2010 | } | |
2011 | *locked = true; | |
2012 | } | |
2013 | ||
2014 | void __mem_cgroup_end_update_page_stat(struct page *page, unsigned long *flags) | |
2015 | { | |
2016 | struct page_cgroup *pc = lookup_page_cgroup(page); | |
2017 | ||
2018 | /* | |
2019 | * It's guaranteed that pc->mem_cgroup never changes while | |
2020 | * lock is held because a routine modifies pc->mem_cgroup | |
da92c47d | 2021 | * should take move_lock_mem_cgroup(). |
89c06bd5 KH |
2022 | */ |
2023 | move_unlock_mem_cgroup(pc->mem_cgroup, flags); | |
2024 | } | |
2025 | ||
2a7106f2 GT |
2026 | void mem_cgroup_update_page_stat(struct page *page, |
2027 | enum mem_cgroup_page_stat_item idx, int val) | |
d69b042f | 2028 | { |
c0ff4b85 | 2029 | struct mem_cgroup *memcg; |
32047e2a | 2030 | struct page_cgroup *pc = lookup_page_cgroup(page); |
dbd4ea78 | 2031 | unsigned long uninitialized_var(flags); |
d69b042f | 2032 | |
cfa44946 | 2033 | if (mem_cgroup_disabled()) |
d69b042f | 2034 | return; |
89c06bd5 | 2035 | |
c0ff4b85 R |
2036 | memcg = pc->mem_cgroup; |
2037 | if (unlikely(!memcg || !PageCgroupUsed(pc))) | |
89c06bd5 | 2038 | return; |
26174efd | 2039 | |
26174efd | 2040 | switch (idx) { |
2a7106f2 | 2041 | case MEMCG_NR_FILE_MAPPED: |
2a7106f2 | 2042 | idx = MEM_CGROUP_STAT_FILE_MAPPED; |
26174efd KH |
2043 | break; |
2044 | default: | |
2045 | BUG(); | |
8725d541 | 2046 | } |
d69b042f | 2047 | |
c0ff4b85 | 2048 | this_cpu_add(memcg->stat->count[idx], val); |
d69b042f | 2049 | } |
26174efd | 2050 | |
cdec2e42 KH |
2051 | /* |
2052 | * size of first charge trial. "32" comes from vmscan.c's magic value. | |
2053 | * TODO: maybe necessary to use big numbers in big irons. | |
2054 | */ | |
7ec99d62 | 2055 | #define CHARGE_BATCH 32U |
cdec2e42 KH |
2056 | struct memcg_stock_pcp { |
2057 | struct mem_cgroup *cached; /* this never be root cgroup */ | |
11c9ea4e | 2058 | unsigned int nr_pages; |
cdec2e42 | 2059 | struct work_struct work; |
26fe6168 | 2060 | unsigned long flags; |
a0db00fc | 2061 | #define FLUSHING_CACHED_CHARGE 0 |
cdec2e42 KH |
2062 | }; |
2063 | static DEFINE_PER_CPU(struct memcg_stock_pcp, memcg_stock); | |
9f50fad6 | 2064 | static DEFINE_MUTEX(percpu_charge_mutex); |
cdec2e42 | 2065 | |
a0956d54 SS |
2066 | /** |
2067 | * consume_stock: Try to consume stocked charge on this cpu. | |
2068 | * @memcg: memcg to consume from. | |
2069 | * @nr_pages: how many pages to charge. | |
2070 | * | |
2071 | * The charges will only happen if @memcg matches the current cpu's memcg | |
2072 | * stock, and at least @nr_pages are available in that stock. Failure to | |
2073 | * service an allocation will refill the stock. | |
2074 | * | |
2075 | * returns true if successful, false otherwise. | |
cdec2e42 | 2076 | */ |
a0956d54 | 2077 | static bool consume_stock(struct mem_cgroup *memcg, unsigned int nr_pages) |
cdec2e42 KH |
2078 | { |
2079 | struct memcg_stock_pcp *stock; | |
2080 | bool ret = true; | |
2081 | ||
a0956d54 SS |
2082 | if (nr_pages > CHARGE_BATCH) |
2083 | return false; | |
2084 | ||
cdec2e42 | 2085 | stock = &get_cpu_var(memcg_stock); |
a0956d54 SS |
2086 | if (memcg == stock->cached && stock->nr_pages >= nr_pages) |
2087 | stock->nr_pages -= nr_pages; | |
cdec2e42 KH |
2088 | else /* need to call res_counter_charge */ |
2089 | ret = false; | |
2090 | put_cpu_var(memcg_stock); | |
2091 | return ret; | |
2092 | } | |
2093 | ||
2094 | /* | |
2095 | * Returns stocks cached in percpu to res_counter and reset cached information. | |
2096 | */ | |
2097 | static void drain_stock(struct memcg_stock_pcp *stock) | |
2098 | { | |
2099 | struct mem_cgroup *old = stock->cached; | |
2100 | ||
11c9ea4e JW |
2101 | if (stock->nr_pages) { |
2102 | unsigned long bytes = stock->nr_pages * PAGE_SIZE; | |
2103 | ||
2104 | res_counter_uncharge(&old->res, bytes); | |
cdec2e42 | 2105 | if (do_swap_account) |
11c9ea4e JW |
2106 | res_counter_uncharge(&old->memsw, bytes); |
2107 | stock->nr_pages = 0; | |
cdec2e42 KH |
2108 | } |
2109 | stock->cached = NULL; | |
cdec2e42 KH |
2110 | } |
2111 | ||
2112 | /* | |
2113 | * This must be called under preempt disabled or must be called by | |
2114 | * a thread which is pinned to local cpu. | |
2115 | */ | |
2116 | static void drain_local_stock(struct work_struct *dummy) | |
2117 | { | |
2118 | struct memcg_stock_pcp *stock = &__get_cpu_var(memcg_stock); | |
2119 | drain_stock(stock); | |
26fe6168 | 2120 | clear_bit(FLUSHING_CACHED_CHARGE, &stock->flags); |
cdec2e42 KH |
2121 | } |
2122 | ||
2123 | /* | |
2124 | * Cache charges(val) which is from res_counter, to local per_cpu area. | |
320cc51d | 2125 | * This will be consumed by consume_stock() function, later. |
cdec2e42 | 2126 | */ |
c0ff4b85 | 2127 | static void refill_stock(struct mem_cgroup *memcg, unsigned int nr_pages) |
cdec2e42 KH |
2128 | { |
2129 | struct memcg_stock_pcp *stock = &get_cpu_var(memcg_stock); | |
2130 | ||
c0ff4b85 | 2131 | if (stock->cached != memcg) { /* reset if necessary */ |
cdec2e42 | 2132 | drain_stock(stock); |
c0ff4b85 | 2133 | stock->cached = memcg; |
cdec2e42 | 2134 | } |
11c9ea4e | 2135 | stock->nr_pages += nr_pages; |
cdec2e42 KH |
2136 | put_cpu_var(memcg_stock); |
2137 | } | |
2138 | ||
2139 | /* | |
c0ff4b85 | 2140 | * Drains all per-CPU charge caches for given root_memcg resp. subtree |
d38144b7 MH |
2141 | * of the hierarchy under it. sync flag says whether we should block |
2142 | * until the work is done. | |
cdec2e42 | 2143 | */ |
c0ff4b85 | 2144 | static void drain_all_stock(struct mem_cgroup *root_memcg, bool sync) |
cdec2e42 | 2145 | { |
26fe6168 | 2146 | int cpu, curcpu; |
d38144b7 | 2147 | |
cdec2e42 | 2148 | /* Notify other cpus that system-wide "drain" is running */ |
cdec2e42 | 2149 | get_online_cpus(); |
5af12d0e | 2150 | curcpu = get_cpu(); |
cdec2e42 KH |
2151 | for_each_online_cpu(cpu) { |
2152 | struct memcg_stock_pcp *stock = &per_cpu(memcg_stock, cpu); | |
c0ff4b85 | 2153 | struct mem_cgroup *memcg; |
26fe6168 | 2154 | |
c0ff4b85 R |
2155 | memcg = stock->cached; |
2156 | if (!memcg || !stock->nr_pages) | |
26fe6168 | 2157 | continue; |
c0ff4b85 | 2158 | if (!mem_cgroup_same_or_subtree(root_memcg, memcg)) |
3e92041d | 2159 | continue; |
d1a05b69 MH |
2160 | if (!test_and_set_bit(FLUSHING_CACHED_CHARGE, &stock->flags)) { |
2161 | if (cpu == curcpu) | |
2162 | drain_local_stock(&stock->work); | |
2163 | else | |
2164 | schedule_work_on(cpu, &stock->work); | |
2165 | } | |
cdec2e42 | 2166 | } |
5af12d0e | 2167 | put_cpu(); |
d38144b7 MH |
2168 | |
2169 | if (!sync) | |
2170 | goto out; | |
2171 | ||
2172 | for_each_online_cpu(cpu) { | |
2173 | struct memcg_stock_pcp *stock = &per_cpu(memcg_stock, cpu); | |
9f50fad6 | 2174 | if (test_bit(FLUSHING_CACHED_CHARGE, &stock->flags)) |
d38144b7 MH |
2175 | flush_work(&stock->work); |
2176 | } | |
2177 | out: | |
cdec2e42 | 2178 | put_online_cpus(); |
d38144b7 MH |
2179 | } |
2180 | ||
2181 | /* | |
2182 | * Tries to drain stocked charges in other cpus. This function is asynchronous | |
2183 | * and just put a work per cpu for draining localy on each cpu. Caller can | |
2184 | * expects some charges will be back to res_counter later but cannot wait for | |
2185 | * it. | |
2186 | */ | |
c0ff4b85 | 2187 | static void drain_all_stock_async(struct mem_cgroup *root_memcg) |
d38144b7 | 2188 | { |
9f50fad6 MH |
2189 | /* |
2190 | * If someone calls draining, avoid adding more kworker runs. | |
2191 | */ | |
2192 | if (!mutex_trylock(&percpu_charge_mutex)) | |
2193 | return; | |
c0ff4b85 | 2194 | drain_all_stock(root_memcg, false); |
9f50fad6 | 2195 | mutex_unlock(&percpu_charge_mutex); |
cdec2e42 KH |
2196 | } |
2197 | ||
2198 | /* This is a synchronous drain interface. */ | |
c0ff4b85 | 2199 | static void drain_all_stock_sync(struct mem_cgroup *root_memcg) |
cdec2e42 KH |
2200 | { |
2201 | /* called when force_empty is called */ | |
9f50fad6 | 2202 | mutex_lock(&percpu_charge_mutex); |
c0ff4b85 | 2203 | drain_all_stock(root_memcg, true); |
9f50fad6 | 2204 | mutex_unlock(&percpu_charge_mutex); |
cdec2e42 KH |
2205 | } |
2206 | ||
711d3d2c KH |
2207 | /* |
2208 | * This function drains percpu counter value from DEAD cpu and | |
2209 | * move it to local cpu. Note that this function can be preempted. | |
2210 | */ | |
c0ff4b85 | 2211 | static void mem_cgroup_drain_pcp_counter(struct mem_cgroup *memcg, int cpu) |
711d3d2c KH |
2212 | { |
2213 | int i; | |
2214 | ||
c0ff4b85 | 2215 | spin_lock(&memcg->pcp_counter_lock); |
6104621d | 2216 | for (i = 0; i < MEM_CGROUP_STAT_NSTATS; i++) { |
c0ff4b85 | 2217 | long x = per_cpu(memcg->stat->count[i], cpu); |
711d3d2c | 2218 | |
c0ff4b85 R |
2219 | per_cpu(memcg->stat->count[i], cpu) = 0; |
2220 | memcg->nocpu_base.count[i] += x; | |
711d3d2c | 2221 | } |
e9f8974f | 2222 | for (i = 0; i < MEM_CGROUP_EVENTS_NSTATS; i++) { |
c0ff4b85 | 2223 | unsigned long x = per_cpu(memcg->stat->events[i], cpu); |
e9f8974f | 2224 | |
c0ff4b85 R |
2225 | per_cpu(memcg->stat->events[i], cpu) = 0; |
2226 | memcg->nocpu_base.events[i] += x; | |
e9f8974f | 2227 | } |
c0ff4b85 | 2228 | spin_unlock(&memcg->pcp_counter_lock); |
711d3d2c KH |
2229 | } |
2230 | ||
2231 | static int __cpuinit memcg_cpu_hotplug_callback(struct notifier_block *nb, | |
cdec2e42 KH |
2232 | unsigned long action, |
2233 | void *hcpu) | |
2234 | { | |
2235 | int cpu = (unsigned long)hcpu; | |
2236 | struct memcg_stock_pcp *stock; | |
711d3d2c | 2237 | struct mem_cgroup *iter; |
cdec2e42 | 2238 | |
619d094b | 2239 | if (action == CPU_ONLINE) |
1489ebad | 2240 | return NOTIFY_OK; |
1489ebad | 2241 | |
d833049b | 2242 | if (action != CPU_DEAD && action != CPU_DEAD_FROZEN) |
cdec2e42 | 2243 | return NOTIFY_OK; |
711d3d2c | 2244 | |
9f3a0d09 | 2245 | for_each_mem_cgroup(iter) |
711d3d2c KH |
2246 | mem_cgroup_drain_pcp_counter(iter, cpu); |
2247 | ||
cdec2e42 KH |
2248 | stock = &per_cpu(memcg_stock, cpu); |
2249 | drain_stock(stock); | |
2250 | return NOTIFY_OK; | |
2251 | } | |
2252 | ||
4b534334 KH |
2253 | |
2254 | /* See __mem_cgroup_try_charge() for details */ | |
2255 | enum { | |
2256 | CHARGE_OK, /* success */ | |
2257 | CHARGE_RETRY, /* need to retry but retry is not bad */ | |
2258 | CHARGE_NOMEM, /* we can't do more. return -ENOMEM */ | |
2259 | CHARGE_WOULDBLOCK, /* GFP_WAIT wasn't set and no enough res. */ | |
2260 | CHARGE_OOM_DIE, /* the current is killed because of OOM */ | |
2261 | }; | |
2262 | ||
c0ff4b85 | 2263 | static int mem_cgroup_do_charge(struct mem_cgroup *memcg, gfp_t gfp_mask, |
4c9c5359 SS |
2264 | unsigned int nr_pages, unsigned int min_pages, |
2265 | bool oom_check) | |
4b534334 | 2266 | { |
7ec99d62 | 2267 | unsigned long csize = nr_pages * PAGE_SIZE; |
4b534334 KH |
2268 | struct mem_cgroup *mem_over_limit; |
2269 | struct res_counter *fail_res; | |
2270 | unsigned long flags = 0; | |
2271 | int ret; | |
2272 | ||
c0ff4b85 | 2273 | ret = res_counter_charge(&memcg->res, csize, &fail_res); |
4b534334 KH |
2274 | |
2275 | if (likely(!ret)) { | |
2276 | if (!do_swap_account) | |
2277 | return CHARGE_OK; | |
c0ff4b85 | 2278 | ret = res_counter_charge(&memcg->memsw, csize, &fail_res); |
4b534334 KH |
2279 | if (likely(!ret)) |
2280 | return CHARGE_OK; | |
2281 | ||
c0ff4b85 | 2282 | res_counter_uncharge(&memcg->res, csize); |
4b534334 KH |
2283 | mem_over_limit = mem_cgroup_from_res_counter(fail_res, memsw); |
2284 | flags |= MEM_CGROUP_RECLAIM_NOSWAP; | |
2285 | } else | |
2286 | mem_over_limit = mem_cgroup_from_res_counter(fail_res, res); | |
9221edb7 | 2287 | /* |
9221edb7 JW |
2288 | * Never reclaim on behalf of optional batching, retry with a |
2289 | * single page instead. | |
2290 | */ | |
4c9c5359 | 2291 | if (nr_pages > min_pages) |
4b534334 KH |
2292 | return CHARGE_RETRY; |
2293 | ||
2294 | if (!(gfp_mask & __GFP_WAIT)) | |
2295 | return CHARGE_WOULDBLOCK; | |
2296 | ||
4c9c5359 SS |
2297 | if (gfp_mask & __GFP_NORETRY) |
2298 | return CHARGE_NOMEM; | |
2299 | ||
5660048c | 2300 | ret = mem_cgroup_reclaim(mem_over_limit, gfp_mask, flags); |
7ec99d62 | 2301 | if (mem_cgroup_margin(mem_over_limit) >= nr_pages) |
19942822 | 2302 | return CHARGE_RETRY; |
4b534334 | 2303 | /* |
19942822 JW |
2304 | * Even though the limit is exceeded at this point, reclaim |
2305 | * may have been able to free some pages. Retry the charge | |
2306 | * before killing the task. | |
2307 | * | |
2308 | * Only for regular pages, though: huge pages are rather | |
2309 | * unlikely to succeed so close to the limit, and we fall back | |
2310 | * to regular pages anyway in case of failure. | |
4b534334 | 2311 | */ |
4c9c5359 | 2312 | if (nr_pages <= (1 << PAGE_ALLOC_COSTLY_ORDER) && ret) |
4b534334 KH |
2313 | return CHARGE_RETRY; |
2314 | ||
2315 | /* | |
2316 | * At task move, charge accounts can be doubly counted. So, it's | |
2317 | * better to wait until the end of task_move if something is going on. | |
2318 | */ | |
2319 | if (mem_cgroup_wait_acct_move(mem_over_limit)) | |
2320 | return CHARGE_RETRY; | |
2321 | ||
2322 | /* If we don't need to call oom-killer at el, return immediately */ | |
2323 | if (!oom_check) | |
2324 | return CHARGE_NOMEM; | |
2325 | /* check OOM */ | |
e845e199 | 2326 | if (!mem_cgroup_handle_oom(mem_over_limit, gfp_mask, get_order(csize))) |
4b534334 KH |
2327 | return CHARGE_OOM_DIE; |
2328 | ||
2329 | return CHARGE_RETRY; | |
2330 | } | |
2331 | ||
f817ed48 | 2332 | /* |
38c5d72f KH |
2333 | * __mem_cgroup_try_charge() does |
2334 | * 1. detect memcg to be charged against from passed *mm and *ptr, | |
2335 | * 2. update res_counter | |
2336 | * 3. call memory reclaim if necessary. | |
2337 | * | |
2338 | * In some special case, if the task is fatal, fatal_signal_pending() or | |
2339 | * has TIF_MEMDIE, this function returns -EINTR while writing root_mem_cgroup | |
2340 | * to *ptr. There are two reasons for this. 1: fatal threads should quit as soon | |
2341 | * as possible without any hazards. 2: all pages should have a valid | |
2342 | * pc->mem_cgroup. If mm is NULL and the caller doesn't pass a valid memcg | |
2343 | * pointer, that is treated as a charge to root_mem_cgroup. | |
2344 | * | |
2345 | * So __mem_cgroup_try_charge() will return | |
2346 | * 0 ... on success, filling *ptr with a valid memcg pointer. | |
2347 | * -ENOMEM ... charge failure because of resource limits. | |
2348 | * -EINTR ... if thread is fatal. *ptr is filled with root_mem_cgroup. | |
2349 | * | |
2350 | * Unlike the exported interface, an "oom" parameter is added. if oom==true, | |
2351 | * the oom-killer can be invoked. | |
8a9f3ccd | 2352 | */ |
f817ed48 | 2353 | static int __mem_cgroup_try_charge(struct mm_struct *mm, |
ec168510 | 2354 | gfp_t gfp_mask, |
7ec99d62 | 2355 | unsigned int nr_pages, |
c0ff4b85 | 2356 | struct mem_cgroup **ptr, |
7ec99d62 | 2357 | bool oom) |
8a9f3ccd | 2358 | { |
7ec99d62 | 2359 | unsigned int batch = max(CHARGE_BATCH, nr_pages); |
4b534334 | 2360 | int nr_oom_retries = MEM_CGROUP_RECLAIM_RETRIES; |
c0ff4b85 | 2361 | struct mem_cgroup *memcg = NULL; |
4b534334 | 2362 | int ret; |
a636b327 | 2363 | |
867578cb KH |
2364 | /* |
2365 | * Unlike gloval-vm's OOM-kill, we're not in memory shortage | |
2366 | * in system level. So, allow to go ahead dying process in addition to | |
2367 | * MEMDIE process. | |
2368 | */ | |
2369 | if (unlikely(test_thread_flag(TIF_MEMDIE) | |
2370 | || fatal_signal_pending(current))) | |
2371 | goto bypass; | |
a636b327 | 2372 | |
8a9f3ccd | 2373 | /* |
3be91277 HD |
2374 | * We always charge the cgroup the mm_struct belongs to. |
2375 | * The mm_struct's mem_cgroup changes on task migration if the | |
8a9f3ccd | 2376 | * thread group leader migrates. It's possible that mm is not |
24467cac | 2377 | * set, if so charge the root memcg (happens for pagecache usage). |
8a9f3ccd | 2378 | */ |
c0ff4b85 | 2379 | if (!*ptr && !mm) |
38c5d72f | 2380 | *ptr = root_mem_cgroup; |
f75ca962 | 2381 | again: |
c0ff4b85 R |
2382 | if (*ptr) { /* css should be a valid one */ |
2383 | memcg = *ptr; | |
c0ff4b85 | 2384 | if (mem_cgroup_is_root(memcg)) |
f75ca962 | 2385 | goto done; |
a0956d54 | 2386 | if (consume_stock(memcg, nr_pages)) |
f75ca962 | 2387 | goto done; |
c0ff4b85 | 2388 | css_get(&memcg->css); |
4b534334 | 2389 | } else { |
f75ca962 | 2390 | struct task_struct *p; |
54595fe2 | 2391 | |
f75ca962 KH |
2392 | rcu_read_lock(); |
2393 | p = rcu_dereference(mm->owner); | |
f75ca962 | 2394 | /* |
ebb76ce1 | 2395 | * Because we don't have task_lock(), "p" can exit. |
c0ff4b85 | 2396 | * In that case, "memcg" can point to root or p can be NULL with |
ebb76ce1 KH |
2397 | * race with swapoff. Then, we have small risk of mis-accouning. |
2398 | * But such kind of mis-account by race always happens because | |
2399 | * we don't have cgroup_mutex(). It's overkill and we allo that | |
2400 | * small race, here. | |
2401 | * (*) swapoff at el will charge against mm-struct not against | |
2402 | * task-struct. So, mm->owner can be NULL. | |
f75ca962 | 2403 | */ |
c0ff4b85 | 2404 | memcg = mem_cgroup_from_task(p); |
38c5d72f KH |
2405 | if (!memcg) |
2406 | memcg = root_mem_cgroup; | |
2407 | if (mem_cgroup_is_root(memcg)) { | |
f75ca962 KH |
2408 | rcu_read_unlock(); |
2409 | goto done; | |
2410 | } | |
a0956d54 | 2411 | if (consume_stock(memcg, nr_pages)) { |
f75ca962 KH |
2412 | /* |
2413 | * It seems dagerous to access memcg without css_get(). | |
2414 | * But considering how consume_stok works, it's not | |
2415 | * necessary. If consume_stock success, some charges | |
2416 | * from this memcg are cached on this cpu. So, we | |
2417 | * don't need to call css_get()/css_tryget() before | |
2418 | * calling consume_stock(). | |
2419 | */ | |
2420 | rcu_read_unlock(); | |
2421 | goto done; | |
2422 | } | |
2423 | /* after here, we may be blocked. we need to get refcnt */ | |
c0ff4b85 | 2424 | if (!css_tryget(&memcg->css)) { |
f75ca962 KH |
2425 | rcu_read_unlock(); |
2426 | goto again; | |
2427 | } | |
2428 | rcu_read_unlock(); | |
2429 | } | |
8a9f3ccd | 2430 | |
4b534334 KH |
2431 | do { |
2432 | bool oom_check; | |
7a81b88c | 2433 | |
4b534334 | 2434 | /* If killed, bypass charge */ |
f75ca962 | 2435 | if (fatal_signal_pending(current)) { |
c0ff4b85 | 2436 | css_put(&memcg->css); |
4b534334 | 2437 | goto bypass; |
f75ca962 | 2438 | } |
6d61ef40 | 2439 | |
4b534334 KH |
2440 | oom_check = false; |
2441 | if (oom && !nr_oom_retries) { | |
2442 | oom_check = true; | |
2443 | nr_oom_retries = MEM_CGROUP_RECLAIM_RETRIES; | |
cdec2e42 | 2444 | } |
66e1707b | 2445 | |
4c9c5359 SS |
2446 | ret = mem_cgroup_do_charge(memcg, gfp_mask, batch, nr_pages, |
2447 | oom_check); | |
4b534334 KH |
2448 | switch (ret) { |
2449 | case CHARGE_OK: | |
2450 | break; | |
2451 | case CHARGE_RETRY: /* not in OOM situation but retry */ | |
7ec99d62 | 2452 | batch = nr_pages; |
c0ff4b85 R |
2453 | css_put(&memcg->css); |
2454 | memcg = NULL; | |
f75ca962 | 2455 | goto again; |
4b534334 | 2456 | case CHARGE_WOULDBLOCK: /* !__GFP_WAIT */ |
c0ff4b85 | 2457 | css_put(&memcg->css); |
4b534334 KH |
2458 | goto nomem; |
2459 | case CHARGE_NOMEM: /* OOM routine works */ | |
f75ca962 | 2460 | if (!oom) { |
c0ff4b85 | 2461 | css_put(&memcg->css); |
867578cb | 2462 | goto nomem; |
f75ca962 | 2463 | } |
4b534334 KH |
2464 | /* If oom, we never return -ENOMEM */ |
2465 | nr_oom_retries--; | |
2466 | break; | |
2467 | case CHARGE_OOM_DIE: /* Killed by OOM Killer */ | |
c0ff4b85 | 2468 | css_put(&memcg->css); |
867578cb | 2469 | goto bypass; |
66e1707b | 2470 | } |
4b534334 KH |
2471 | } while (ret != CHARGE_OK); |
2472 | ||
7ec99d62 | 2473 | if (batch > nr_pages) |
c0ff4b85 R |
2474 | refill_stock(memcg, batch - nr_pages); |
2475 | css_put(&memcg->css); | |
0c3e73e8 | 2476 | done: |
c0ff4b85 | 2477 | *ptr = memcg; |
7a81b88c KH |
2478 | return 0; |
2479 | nomem: | |
c0ff4b85 | 2480 | *ptr = NULL; |
7a81b88c | 2481 | return -ENOMEM; |
867578cb | 2482 | bypass: |
38c5d72f KH |
2483 | *ptr = root_mem_cgroup; |
2484 | return -EINTR; | |
7a81b88c | 2485 | } |
8a9f3ccd | 2486 | |
a3032a2c DN |
2487 | /* |
2488 | * Somemtimes we have to undo a charge we got by try_charge(). | |
2489 | * This function is for that and do uncharge, put css's refcnt. | |
2490 | * gotten by try_charge(). | |
2491 | */ | |
c0ff4b85 | 2492 | static void __mem_cgroup_cancel_charge(struct mem_cgroup *memcg, |
e7018b8d | 2493 | unsigned int nr_pages) |
a3032a2c | 2494 | { |
c0ff4b85 | 2495 | if (!mem_cgroup_is_root(memcg)) { |
e7018b8d JW |
2496 | unsigned long bytes = nr_pages * PAGE_SIZE; |
2497 | ||
c0ff4b85 | 2498 | res_counter_uncharge(&memcg->res, bytes); |
a3032a2c | 2499 | if (do_swap_account) |
c0ff4b85 | 2500 | res_counter_uncharge(&memcg->memsw, bytes); |
a3032a2c | 2501 | } |
854ffa8d DN |
2502 | } |
2503 | ||
d01dd17f KH |
2504 | /* |
2505 | * Cancel chrages in this cgroup....doesn't propagate to parent cgroup. | |
2506 | * This is useful when moving usage to parent cgroup. | |
2507 | */ | |
2508 | static void __mem_cgroup_cancel_local_charge(struct mem_cgroup *memcg, | |
2509 | unsigned int nr_pages) | |
2510 | { | |
2511 | unsigned long bytes = nr_pages * PAGE_SIZE; | |
2512 | ||
2513 | if (mem_cgroup_is_root(memcg)) | |
2514 | return; | |
2515 | ||
2516 | res_counter_uncharge_until(&memcg->res, memcg->res.parent, bytes); | |
2517 | if (do_swap_account) | |
2518 | res_counter_uncharge_until(&memcg->memsw, | |
2519 | memcg->memsw.parent, bytes); | |
2520 | } | |
2521 | ||
a3b2d692 KH |
2522 | /* |
2523 | * A helper function to get mem_cgroup from ID. must be called under | |
e9316080 TH |
2524 | * rcu_read_lock(). The caller is responsible for calling css_tryget if |
2525 | * the mem_cgroup is used for charging. (dropping refcnt from swap can be | |
2526 | * called against removed memcg.) | |
a3b2d692 KH |
2527 | */ |
2528 | static struct mem_cgroup *mem_cgroup_lookup(unsigned short id) | |
2529 | { | |
2530 | struct cgroup_subsys_state *css; | |
2531 | ||
2532 | /* ID 0 is unused ID */ | |
2533 | if (!id) | |
2534 | return NULL; | |
2535 | css = css_lookup(&mem_cgroup_subsys, id); | |
2536 | if (!css) | |
2537 | return NULL; | |
b2145145 | 2538 | return mem_cgroup_from_css(css); |
a3b2d692 KH |
2539 | } |
2540 | ||
e42d9d5d | 2541 | struct mem_cgroup *try_get_mem_cgroup_from_page(struct page *page) |
b5a84319 | 2542 | { |
c0ff4b85 | 2543 | struct mem_cgroup *memcg = NULL; |
3c776e64 | 2544 | struct page_cgroup *pc; |
a3b2d692 | 2545 | unsigned short id; |
b5a84319 KH |
2546 | swp_entry_t ent; |
2547 | ||
3c776e64 DN |
2548 | VM_BUG_ON(!PageLocked(page)); |
2549 | ||
3c776e64 | 2550 | pc = lookup_page_cgroup(page); |
c0bd3f63 | 2551 | lock_page_cgroup(pc); |
a3b2d692 | 2552 | if (PageCgroupUsed(pc)) { |
c0ff4b85 R |
2553 | memcg = pc->mem_cgroup; |
2554 | if (memcg && !css_tryget(&memcg->css)) | |
2555 | memcg = NULL; | |
e42d9d5d | 2556 | } else if (PageSwapCache(page)) { |
3c776e64 | 2557 | ent.val = page_private(page); |
9fb4b7cc | 2558 | id = lookup_swap_cgroup_id(ent); |
a3b2d692 | 2559 | rcu_read_lock(); |
c0ff4b85 R |
2560 | memcg = mem_cgroup_lookup(id); |
2561 | if (memcg && !css_tryget(&memcg->css)) | |
2562 | memcg = NULL; | |
a3b2d692 | 2563 | rcu_read_unlock(); |
3c776e64 | 2564 | } |
c0bd3f63 | 2565 | unlock_page_cgroup(pc); |
c0ff4b85 | 2566 | return memcg; |
b5a84319 KH |
2567 | } |
2568 | ||
c0ff4b85 | 2569 | static void __mem_cgroup_commit_charge(struct mem_cgroup *memcg, |
5564e88b | 2570 | struct page *page, |
7ec99d62 | 2571 | unsigned int nr_pages, |
9ce70c02 HD |
2572 | enum charge_type ctype, |
2573 | bool lrucare) | |
7a81b88c | 2574 | { |
ce587e65 | 2575 | struct page_cgroup *pc = lookup_page_cgroup(page); |
9ce70c02 | 2576 | struct zone *uninitialized_var(zone); |
fa9add64 | 2577 | struct lruvec *lruvec; |
9ce70c02 | 2578 | bool was_on_lru = false; |
b2402857 | 2579 | bool anon; |
9ce70c02 | 2580 | |
ca3e0214 | 2581 | lock_page_cgroup(pc); |
90deb788 | 2582 | VM_BUG_ON(PageCgroupUsed(pc)); |
ca3e0214 KH |
2583 | /* |
2584 | * we don't need page_cgroup_lock about tail pages, becase they are not | |
2585 | * accessed by any other context at this point. | |
2586 | */ | |
9ce70c02 HD |
2587 | |
2588 | /* | |
2589 | * In some cases, SwapCache and FUSE(splice_buf->radixtree), the page | |
2590 | * may already be on some other mem_cgroup's LRU. Take care of it. | |
2591 | */ | |
2592 | if (lrucare) { | |
2593 | zone = page_zone(page); | |
2594 | spin_lock_irq(&zone->lru_lock); | |
2595 | if (PageLRU(page)) { | |
fa9add64 | 2596 | lruvec = mem_cgroup_zone_lruvec(zone, pc->mem_cgroup); |
9ce70c02 | 2597 | ClearPageLRU(page); |
fa9add64 | 2598 | del_page_from_lru_list(page, lruvec, page_lru(page)); |
9ce70c02 HD |
2599 | was_on_lru = true; |
2600 | } | |
2601 | } | |
2602 | ||
c0ff4b85 | 2603 | pc->mem_cgroup = memcg; |
261fb61a KH |
2604 | /* |
2605 | * We access a page_cgroup asynchronously without lock_page_cgroup(). | |
2606 | * Especially when a page_cgroup is taken from a page, pc->mem_cgroup | |
2607 | * is accessed after testing USED bit. To make pc->mem_cgroup visible | |
2608 | * before USED bit, we need memory barrier here. | |
2609 | * See mem_cgroup_add_lru_list(), etc. | |
2610 | */ | |
08e552c6 | 2611 | smp_wmb(); |
b2402857 | 2612 | SetPageCgroupUsed(pc); |
3be91277 | 2613 | |
9ce70c02 HD |
2614 | if (lrucare) { |
2615 | if (was_on_lru) { | |
fa9add64 | 2616 | lruvec = mem_cgroup_zone_lruvec(zone, pc->mem_cgroup); |
9ce70c02 HD |
2617 | VM_BUG_ON(PageLRU(page)); |
2618 | SetPageLRU(page); | |
fa9add64 | 2619 | add_page_to_lru_list(page, lruvec, page_lru(page)); |
9ce70c02 HD |
2620 | } |
2621 | spin_unlock_irq(&zone->lru_lock); | |
2622 | } | |
2623 | ||
41326c17 | 2624 | if (ctype == MEM_CGROUP_CHARGE_TYPE_ANON) |
b2402857 KH |
2625 | anon = true; |
2626 | else | |
2627 | anon = false; | |
2628 | ||
2629 | mem_cgroup_charge_statistics(memcg, anon, nr_pages); | |
52d4b9ac | 2630 | unlock_page_cgroup(pc); |
9ce70c02 | 2631 | |
430e4863 KH |
2632 | /* |
2633 | * "charge_statistics" updated event counter. Then, check it. | |
2634 | * Insert ancestor (and ancestor's ancestors), to softlimit RB-tree. | |
2635 | * if they exceeds softlimit. | |
2636 | */ | |
c0ff4b85 | 2637 | memcg_check_events(memcg, page); |
7a81b88c | 2638 | } |
66e1707b | 2639 | |
ca3e0214 KH |
2640 | #ifdef CONFIG_TRANSPARENT_HUGEPAGE |
2641 | ||
a0db00fc | 2642 | #define PCGF_NOCOPY_AT_SPLIT (1 << PCG_LOCK | 1 << PCG_MIGRATION) |
ca3e0214 KH |
2643 | /* |
2644 | * Because tail pages are not marked as "used", set it. We're under | |
e94c8a9c KH |
2645 | * zone->lru_lock, 'splitting on pmd' and compound_lock. |
2646 | * charge/uncharge will be never happen and move_account() is done under | |
2647 | * compound_lock(), so we don't have to take care of races. | |
ca3e0214 | 2648 | */ |
e94c8a9c | 2649 | void mem_cgroup_split_huge_fixup(struct page *head) |
ca3e0214 KH |
2650 | { |
2651 | struct page_cgroup *head_pc = lookup_page_cgroup(head); | |
e94c8a9c KH |
2652 | struct page_cgroup *pc; |
2653 | int i; | |
ca3e0214 | 2654 | |
3d37c4a9 KH |
2655 | if (mem_cgroup_disabled()) |
2656 | return; | |
e94c8a9c KH |
2657 | for (i = 1; i < HPAGE_PMD_NR; i++) { |
2658 | pc = head_pc + i; | |
2659 | pc->mem_cgroup = head_pc->mem_cgroup; | |
2660 | smp_wmb();/* see __commit_charge() */ | |
e94c8a9c KH |
2661 | pc->flags = head_pc->flags & ~PCGF_NOCOPY_AT_SPLIT; |
2662 | } | |
ca3e0214 | 2663 | } |
12d27107 | 2664 | #endif /* CONFIG_TRANSPARENT_HUGEPAGE */ |
ca3e0214 | 2665 | |
f817ed48 | 2666 | /** |
de3638d9 | 2667 | * mem_cgroup_move_account - move account of the page |
5564e88b | 2668 | * @page: the page |
7ec99d62 | 2669 | * @nr_pages: number of regular pages (>1 for huge pages) |
f817ed48 KH |
2670 | * @pc: page_cgroup of the page. |
2671 | * @from: mem_cgroup which the page is moved from. | |
2672 | * @to: mem_cgroup which the page is moved to. @from != @to. | |
2673 | * | |
2674 | * The caller must confirm following. | |
08e552c6 | 2675 | * - page is not on LRU (isolate_page() is useful.) |
7ec99d62 | 2676 | * - compound_lock is held when nr_pages > 1 |
f817ed48 | 2677 | * |
2f3479b1 KH |
2678 | * This function doesn't do "charge" to new cgroup and doesn't do "uncharge" |
2679 | * from old cgroup. | |
f817ed48 | 2680 | */ |
7ec99d62 JW |
2681 | static int mem_cgroup_move_account(struct page *page, |
2682 | unsigned int nr_pages, | |
2683 | struct page_cgroup *pc, | |
2684 | struct mem_cgroup *from, | |
2f3479b1 | 2685 | struct mem_cgroup *to) |
f817ed48 | 2686 | { |
de3638d9 JW |
2687 | unsigned long flags; |
2688 | int ret; | |
b2402857 | 2689 | bool anon = PageAnon(page); |
987eba66 | 2690 | |
f817ed48 | 2691 | VM_BUG_ON(from == to); |
5564e88b | 2692 | VM_BUG_ON(PageLRU(page)); |
de3638d9 JW |
2693 | /* |
2694 | * The page is isolated from LRU. So, collapse function | |
2695 | * will not handle this page. But page splitting can happen. | |
2696 | * Do this check under compound_page_lock(). The caller should | |
2697 | * hold it. | |
2698 | */ | |
2699 | ret = -EBUSY; | |
7ec99d62 | 2700 | if (nr_pages > 1 && !PageTransHuge(page)) |
de3638d9 JW |
2701 | goto out; |
2702 | ||
2703 | lock_page_cgroup(pc); | |
2704 | ||
2705 | ret = -EINVAL; | |
2706 | if (!PageCgroupUsed(pc) || pc->mem_cgroup != from) | |
2707 | goto unlock; | |
2708 | ||
312734c0 | 2709 | move_lock_mem_cgroup(from, &flags); |
f817ed48 | 2710 | |
2ff76f11 | 2711 | if (!anon && page_mapped(page)) { |
c62b1a3b KH |
2712 | /* Update mapped_file data for mem_cgroup */ |
2713 | preempt_disable(); | |
2714 | __this_cpu_dec(from->stat->count[MEM_CGROUP_STAT_FILE_MAPPED]); | |
2715 | __this_cpu_inc(to->stat->count[MEM_CGROUP_STAT_FILE_MAPPED]); | |
2716 | preempt_enable(); | |
d69b042f | 2717 | } |
b2402857 | 2718 | mem_cgroup_charge_statistics(from, anon, -nr_pages); |
d69b042f | 2719 | |
854ffa8d | 2720 | /* caller should have done css_get */ |
08e552c6 | 2721 | pc->mem_cgroup = to; |
b2402857 | 2722 | mem_cgroup_charge_statistics(to, anon, nr_pages); |
312734c0 | 2723 | move_unlock_mem_cgroup(from, &flags); |
de3638d9 JW |
2724 | ret = 0; |
2725 | unlock: | |
57f9fd7d | 2726 | unlock_page_cgroup(pc); |
d2265e6f KH |
2727 | /* |
2728 | * check events | |
2729 | */ | |
5564e88b JW |
2730 | memcg_check_events(to, page); |
2731 | memcg_check_events(from, page); | |
de3638d9 | 2732 | out: |
f817ed48 KH |
2733 | return ret; |
2734 | } | |
2735 | ||
2ef37d3f MH |
2736 | /** |
2737 | * mem_cgroup_move_parent - moves page to the parent group | |
2738 | * @page: the page to move | |
2739 | * @pc: page_cgroup of the page | |
2740 | * @child: page's cgroup | |
2741 | * | |
2742 | * move charges to its parent or the root cgroup if the group has no | |
2743 | * parent (aka use_hierarchy==0). | |
2744 | * Although this might fail (get_page_unless_zero, isolate_lru_page or | |
2745 | * mem_cgroup_move_account fails) the failure is always temporary and | |
2746 | * it signals a race with a page removal/uncharge or migration. In the | |
2747 | * first case the page is on the way out and it will vanish from the LRU | |
2748 | * on the next attempt and the call should be retried later. | |
2749 | * Isolation from the LRU fails only if page has been isolated from | |
2750 | * the LRU since we looked at it and that usually means either global | |
2751 | * reclaim or migration going on. The page will either get back to the | |
2752 | * LRU or vanish. | |
2753 | * Finaly mem_cgroup_move_account fails only if the page got uncharged | |
2754 | * (!PageCgroupUsed) or moved to a different group. The page will | |
2755 | * disappear in the next attempt. | |
f817ed48 | 2756 | */ |
5564e88b JW |
2757 | static int mem_cgroup_move_parent(struct page *page, |
2758 | struct page_cgroup *pc, | |
6068bf01 | 2759 | struct mem_cgroup *child) |
f817ed48 | 2760 | { |
f817ed48 | 2761 | struct mem_cgroup *parent; |
7ec99d62 | 2762 | unsigned int nr_pages; |
4be4489f | 2763 | unsigned long uninitialized_var(flags); |
f817ed48 KH |
2764 | int ret; |
2765 | ||
d8423011 | 2766 | VM_BUG_ON(mem_cgroup_is_root(child)); |
f817ed48 | 2767 | |
57f9fd7d DN |
2768 | ret = -EBUSY; |
2769 | if (!get_page_unless_zero(page)) | |
2770 | goto out; | |
2771 | if (isolate_lru_page(page)) | |
2772 | goto put; | |
52dbb905 | 2773 | |
7ec99d62 | 2774 | nr_pages = hpage_nr_pages(page); |
08e552c6 | 2775 | |
cc926f78 KH |
2776 | parent = parent_mem_cgroup(child); |
2777 | /* | |
2778 | * If no parent, move charges to root cgroup. | |
2779 | */ | |
2780 | if (!parent) | |
2781 | parent = root_mem_cgroup; | |
f817ed48 | 2782 | |
2ef37d3f MH |
2783 | if (nr_pages > 1) { |
2784 | VM_BUG_ON(!PageTransHuge(page)); | |
987eba66 | 2785 | flags = compound_lock_irqsave(page); |
2ef37d3f | 2786 | } |
987eba66 | 2787 | |
cc926f78 | 2788 | ret = mem_cgroup_move_account(page, nr_pages, |
2f3479b1 | 2789 | pc, child, parent); |
cc926f78 KH |
2790 | if (!ret) |
2791 | __mem_cgroup_cancel_local_charge(child, nr_pages); | |
8dba474f | 2792 | |
7ec99d62 | 2793 | if (nr_pages > 1) |
987eba66 | 2794 | compound_unlock_irqrestore(page, flags); |
08e552c6 | 2795 | putback_lru_page(page); |
57f9fd7d | 2796 | put: |
40d58138 | 2797 | put_page(page); |
57f9fd7d | 2798 | out: |
f817ed48 KH |
2799 | return ret; |
2800 | } | |
2801 | ||
7a81b88c KH |
2802 | /* |
2803 | * Charge the memory controller for page usage. | |
2804 | * Return | |
2805 | * 0 if the charge was successful | |
2806 | * < 0 if the cgroup is over its limit | |
2807 | */ | |
2808 | static int mem_cgroup_charge_common(struct page *page, struct mm_struct *mm, | |
73045c47 | 2809 | gfp_t gfp_mask, enum charge_type ctype) |
7a81b88c | 2810 | { |
c0ff4b85 | 2811 | struct mem_cgroup *memcg = NULL; |
7ec99d62 | 2812 | unsigned int nr_pages = 1; |
8493ae43 | 2813 | bool oom = true; |
7a81b88c | 2814 | int ret; |
ec168510 | 2815 | |
37c2ac78 | 2816 | if (PageTransHuge(page)) { |
7ec99d62 | 2817 | nr_pages <<= compound_order(page); |
37c2ac78 | 2818 | VM_BUG_ON(!PageTransHuge(page)); |
8493ae43 JW |
2819 | /* |
2820 | * Never OOM-kill a process for a huge page. The | |
2821 | * fault handler will fall back to regular pages. | |
2822 | */ | |
2823 | oom = false; | |
37c2ac78 | 2824 | } |
7a81b88c | 2825 | |
c0ff4b85 | 2826 | ret = __mem_cgroup_try_charge(mm, gfp_mask, nr_pages, &memcg, oom); |
38c5d72f | 2827 | if (ret == -ENOMEM) |
7a81b88c | 2828 | return ret; |
ce587e65 | 2829 | __mem_cgroup_commit_charge(memcg, page, nr_pages, ctype, false); |
8a9f3ccd | 2830 | return 0; |
8a9f3ccd BS |
2831 | } |
2832 | ||
7a81b88c KH |
2833 | int mem_cgroup_newpage_charge(struct page *page, |
2834 | struct mm_struct *mm, gfp_t gfp_mask) | |
217bc319 | 2835 | { |
f8d66542 | 2836 | if (mem_cgroup_disabled()) |
cede86ac | 2837 | return 0; |
7a0524cf JW |
2838 | VM_BUG_ON(page_mapped(page)); |
2839 | VM_BUG_ON(page->mapping && !PageAnon(page)); | |
2840 | VM_BUG_ON(!mm); | |
217bc319 | 2841 | return mem_cgroup_charge_common(page, mm, gfp_mask, |
41326c17 | 2842 | MEM_CGROUP_CHARGE_TYPE_ANON); |
217bc319 KH |
2843 | } |
2844 | ||
54595fe2 KH |
2845 | /* |
2846 | * While swap-in, try_charge -> commit or cancel, the page is locked. | |
2847 | * And when try_charge() successfully returns, one refcnt to memcg without | |
21ae2956 | 2848 | * struct page_cgroup is acquired. This refcnt will be consumed by |
54595fe2 KH |
2849 | * "commit()" or removed by "cancel()" |
2850 | */ | |
0435a2fd JW |
2851 | static int __mem_cgroup_try_charge_swapin(struct mm_struct *mm, |
2852 | struct page *page, | |
2853 | gfp_t mask, | |
2854 | struct mem_cgroup **memcgp) | |
8c7c6e34 | 2855 | { |
c0ff4b85 | 2856 | struct mem_cgroup *memcg; |
90deb788 | 2857 | struct page_cgroup *pc; |
54595fe2 | 2858 | int ret; |
8c7c6e34 | 2859 | |
90deb788 JW |
2860 | pc = lookup_page_cgroup(page); |
2861 | /* | |
2862 | * Every swap fault against a single page tries to charge the | |
2863 | * page, bail as early as possible. shmem_unuse() encounters | |
2864 | * already charged pages, too. The USED bit is protected by | |
2865 | * the page lock, which serializes swap cache removal, which | |
2866 | * in turn serializes uncharging. | |
2867 | */ | |
2868 | if (PageCgroupUsed(pc)) | |
2869 | return 0; | |
8c7c6e34 KH |
2870 | if (!do_swap_account) |
2871 | goto charge_cur_mm; | |
c0ff4b85 R |
2872 | memcg = try_get_mem_cgroup_from_page(page); |
2873 | if (!memcg) | |
54595fe2 | 2874 | goto charge_cur_mm; |
72835c86 JW |
2875 | *memcgp = memcg; |
2876 | ret = __mem_cgroup_try_charge(NULL, mask, 1, memcgp, true); | |
c0ff4b85 | 2877 | css_put(&memcg->css); |
38c5d72f KH |
2878 | if (ret == -EINTR) |
2879 | ret = 0; | |
54595fe2 | 2880 | return ret; |
8c7c6e34 | 2881 | charge_cur_mm: |
38c5d72f KH |
2882 | ret = __mem_cgroup_try_charge(mm, mask, 1, memcgp, true); |
2883 | if (ret == -EINTR) | |
2884 | ret = 0; | |
2885 | return ret; | |
8c7c6e34 KH |
2886 | } |
2887 | ||
0435a2fd JW |
2888 | int mem_cgroup_try_charge_swapin(struct mm_struct *mm, struct page *page, |
2889 | gfp_t gfp_mask, struct mem_cgroup **memcgp) | |
2890 | { | |
2891 | *memcgp = NULL; | |
2892 | if (mem_cgroup_disabled()) | |
2893 | return 0; | |
bdf4f4d2 JW |
2894 | /* |
2895 | * A racing thread's fault, or swapoff, may have already | |
2896 | * updated the pte, and even removed page from swap cache: in | |
2897 | * those cases unuse_pte()'s pte_same() test will fail; but | |
2898 | * there's also a KSM case which does need to charge the page. | |
2899 | */ | |
2900 | if (!PageSwapCache(page)) { | |
2901 | int ret; | |
2902 | ||
2903 | ret = __mem_cgroup_try_charge(mm, gfp_mask, 1, memcgp, true); | |
2904 | if (ret == -EINTR) | |
2905 | ret = 0; | |
2906 | return ret; | |
2907 | } | |
0435a2fd JW |
2908 | return __mem_cgroup_try_charge_swapin(mm, page, gfp_mask, memcgp); |
2909 | } | |
2910 | ||
827a03d2 JW |
2911 | void mem_cgroup_cancel_charge_swapin(struct mem_cgroup *memcg) |
2912 | { | |
2913 | if (mem_cgroup_disabled()) | |
2914 | return; | |
2915 | if (!memcg) | |
2916 | return; | |
2917 | __mem_cgroup_cancel_charge(memcg, 1); | |
2918 | } | |
2919 | ||
83aae4c7 | 2920 | static void |
72835c86 | 2921 | __mem_cgroup_commit_charge_swapin(struct page *page, struct mem_cgroup *memcg, |
83aae4c7 | 2922 | enum charge_type ctype) |
7a81b88c | 2923 | { |
f8d66542 | 2924 | if (mem_cgroup_disabled()) |
7a81b88c | 2925 | return; |
72835c86 | 2926 | if (!memcg) |
7a81b88c | 2927 | return; |
5a6475a4 | 2928 | |
ce587e65 | 2929 | __mem_cgroup_commit_charge(memcg, page, 1, ctype, true); |
8c7c6e34 KH |
2930 | /* |
2931 | * Now swap is on-memory. This means this page may be | |
2932 | * counted both as mem and swap....double count. | |
03f3c433 KH |
2933 | * Fix it by uncharging from memsw. Basically, this SwapCache is stable |
2934 | * under lock_page(). But in do_swap_page()::memory.c, reuse_swap_page() | |
2935 | * may call delete_from_swap_cache() before reach here. | |
8c7c6e34 | 2936 | */ |
03f3c433 | 2937 | if (do_swap_account && PageSwapCache(page)) { |
8c7c6e34 | 2938 | swp_entry_t ent = {.val = page_private(page)}; |
86493009 | 2939 | mem_cgroup_uncharge_swap(ent); |
8c7c6e34 | 2940 | } |
7a81b88c KH |
2941 | } |
2942 | ||
72835c86 JW |
2943 | void mem_cgroup_commit_charge_swapin(struct page *page, |
2944 | struct mem_cgroup *memcg) | |
83aae4c7 | 2945 | { |
72835c86 | 2946 | __mem_cgroup_commit_charge_swapin(page, memcg, |
41326c17 | 2947 | MEM_CGROUP_CHARGE_TYPE_ANON); |
83aae4c7 DN |
2948 | } |
2949 | ||
827a03d2 JW |
2950 | int mem_cgroup_cache_charge(struct page *page, struct mm_struct *mm, |
2951 | gfp_t gfp_mask) | |
7a81b88c | 2952 | { |
827a03d2 JW |
2953 | struct mem_cgroup *memcg = NULL; |
2954 | enum charge_type type = MEM_CGROUP_CHARGE_TYPE_CACHE; | |
2955 | int ret; | |
2956 | ||
f8d66542 | 2957 | if (mem_cgroup_disabled()) |
827a03d2 JW |
2958 | return 0; |
2959 | if (PageCompound(page)) | |
2960 | return 0; | |
2961 | ||
827a03d2 JW |
2962 | if (!PageSwapCache(page)) |
2963 | ret = mem_cgroup_charge_common(page, mm, gfp_mask, type); | |
2964 | else { /* page is swapcache/shmem */ | |
0435a2fd JW |
2965 | ret = __mem_cgroup_try_charge_swapin(mm, page, |
2966 | gfp_mask, &memcg); | |
827a03d2 JW |
2967 | if (!ret) |
2968 | __mem_cgroup_commit_charge_swapin(page, memcg, type); | |
2969 | } | |
2970 | return ret; | |
7a81b88c KH |
2971 | } |
2972 | ||
c0ff4b85 | 2973 | static void mem_cgroup_do_uncharge(struct mem_cgroup *memcg, |
7ec99d62 JW |
2974 | unsigned int nr_pages, |
2975 | const enum charge_type ctype) | |
569b846d KH |
2976 | { |
2977 | struct memcg_batch_info *batch = NULL; | |
2978 | bool uncharge_memsw = true; | |
7ec99d62 | 2979 | |
569b846d KH |
2980 | /* If swapout, usage of swap doesn't decrease */ |
2981 | if (!do_swap_account || ctype == MEM_CGROUP_CHARGE_TYPE_SWAPOUT) | |
2982 | uncharge_memsw = false; | |
569b846d KH |
2983 | |
2984 | batch = ¤t->memcg_batch; | |
2985 | /* | |
2986 | * In usual, we do css_get() when we remember memcg pointer. | |
2987 | * But in this case, we keep res->usage until end of a series of | |
2988 | * uncharges. Then, it's ok to ignore memcg's refcnt. | |
2989 | */ | |
2990 | if (!batch->memcg) | |
c0ff4b85 | 2991 | batch->memcg = memcg; |
3c11ecf4 KH |
2992 | /* |
2993 | * do_batch > 0 when unmapping pages or inode invalidate/truncate. | |
25985edc | 2994 | * In those cases, all pages freed continuously can be expected to be in |
3c11ecf4 KH |
2995 | * the same cgroup and we have chance to coalesce uncharges. |
2996 | * But we do uncharge one by one if this is killed by OOM(TIF_MEMDIE) | |
2997 | * because we want to do uncharge as soon as possible. | |
2998 | */ | |
2999 | ||
3000 | if (!batch->do_batch || test_thread_flag(TIF_MEMDIE)) | |
3001 | goto direct_uncharge; | |
3002 | ||
7ec99d62 | 3003 | if (nr_pages > 1) |
ec168510 AA |
3004 | goto direct_uncharge; |
3005 | ||
569b846d KH |
3006 | /* |
3007 | * In typical case, batch->memcg == mem. This means we can | |
3008 | * merge a series of uncharges to an uncharge of res_counter. | |
3009 | * If not, we uncharge res_counter ony by one. | |
3010 | */ | |
c0ff4b85 | 3011 | if (batch->memcg != memcg) |
569b846d KH |
3012 | goto direct_uncharge; |
3013 | /* remember freed charge and uncharge it later */ | |
7ffd4ca7 | 3014 | batch->nr_pages++; |
569b846d | 3015 | if (uncharge_memsw) |
7ffd4ca7 | 3016 | batch->memsw_nr_pages++; |
569b846d KH |
3017 | return; |
3018 | direct_uncharge: | |
c0ff4b85 | 3019 | res_counter_uncharge(&memcg->res, nr_pages * PAGE_SIZE); |
569b846d | 3020 | if (uncharge_memsw) |
c0ff4b85 R |
3021 | res_counter_uncharge(&memcg->memsw, nr_pages * PAGE_SIZE); |
3022 | if (unlikely(batch->memcg != memcg)) | |
3023 | memcg_oom_recover(memcg); | |
569b846d | 3024 | } |
7a81b88c | 3025 | |
8a9f3ccd | 3026 | /* |
69029cd5 | 3027 | * uncharge if !page_mapped(page) |
8a9f3ccd | 3028 | */ |
8c7c6e34 | 3029 | static struct mem_cgroup * |
0030f535 JW |
3030 | __mem_cgroup_uncharge_common(struct page *page, enum charge_type ctype, |
3031 | bool end_migration) | |
8a9f3ccd | 3032 | { |
c0ff4b85 | 3033 | struct mem_cgroup *memcg = NULL; |
7ec99d62 JW |
3034 | unsigned int nr_pages = 1; |
3035 | struct page_cgroup *pc; | |
b2402857 | 3036 | bool anon; |
8a9f3ccd | 3037 | |
f8d66542 | 3038 | if (mem_cgroup_disabled()) |
8c7c6e34 | 3039 | return NULL; |
4077960e | 3040 | |
0c59b89c | 3041 | VM_BUG_ON(PageSwapCache(page)); |
d13d1443 | 3042 | |
37c2ac78 | 3043 | if (PageTransHuge(page)) { |
7ec99d62 | 3044 | nr_pages <<= compound_order(page); |
37c2ac78 AA |
3045 | VM_BUG_ON(!PageTransHuge(page)); |
3046 | } | |
8697d331 | 3047 | /* |
3c541e14 | 3048 | * Check if our page_cgroup is valid |
8697d331 | 3049 | */ |
52d4b9ac | 3050 | pc = lookup_page_cgroup(page); |
cfa44946 | 3051 | if (unlikely(!PageCgroupUsed(pc))) |
8c7c6e34 | 3052 | return NULL; |
b9c565d5 | 3053 | |
52d4b9ac | 3054 | lock_page_cgroup(pc); |
d13d1443 | 3055 | |
c0ff4b85 | 3056 | memcg = pc->mem_cgroup; |
8c7c6e34 | 3057 | |
d13d1443 KH |
3058 | if (!PageCgroupUsed(pc)) |
3059 | goto unlock_out; | |
3060 | ||
b2402857 KH |
3061 | anon = PageAnon(page); |
3062 | ||
d13d1443 | 3063 | switch (ctype) { |
41326c17 | 3064 | case MEM_CGROUP_CHARGE_TYPE_ANON: |
2ff76f11 KH |
3065 | /* |
3066 | * Generally PageAnon tells if it's the anon statistics to be | |
3067 | * updated; but sometimes e.g. mem_cgroup_uncharge_page() is | |
3068 | * used before page reached the stage of being marked PageAnon. | |
3069 | */ | |
b2402857 KH |
3070 | anon = true; |
3071 | /* fallthrough */ | |
8a9478ca | 3072 | case MEM_CGROUP_CHARGE_TYPE_DROP: |
ac39cf8c | 3073 | /* See mem_cgroup_prepare_migration() */ |
0030f535 JW |
3074 | if (page_mapped(page)) |
3075 | goto unlock_out; | |
3076 | /* | |
3077 | * Pages under migration may not be uncharged. But | |
3078 | * end_migration() /must/ be the one uncharging the | |
3079 | * unused post-migration page and so it has to call | |
3080 | * here with the migration bit still set. See the | |
3081 | * res_counter handling below. | |
3082 | */ | |
3083 | if (!end_migration && PageCgroupMigration(pc)) | |
d13d1443 KH |
3084 | goto unlock_out; |
3085 | break; | |
3086 | case MEM_CGROUP_CHARGE_TYPE_SWAPOUT: | |
3087 | if (!PageAnon(page)) { /* Shared memory */ | |
3088 | if (page->mapping && !page_is_file_cache(page)) | |
3089 | goto unlock_out; | |
3090 | } else if (page_mapped(page)) /* Anon */ | |
3091 | goto unlock_out; | |
3092 | break; | |
3093 | default: | |
3094 | break; | |
52d4b9ac | 3095 | } |
d13d1443 | 3096 | |
b2402857 | 3097 | mem_cgroup_charge_statistics(memcg, anon, -nr_pages); |
04046e1a | 3098 | |
52d4b9ac | 3099 | ClearPageCgroupUsed(pc); |
544122e5 KH |
3100 | /* |
3101 | * pc->mem_cgroup is not cleared here. It will be accessed when it's | |
3102 | * freed from LRU. This is safe because uncharged page is expected not | |
3103 | * to be reused (freed soon). Exception is SwapCache, it's handled by | |
3104 | * special functions. | |
3105 | */ | |
b9c565d5 | 3106 | |
52d4b9ac | 3107 | unlock_page_cgroup(pc); |
f75ca962 | 3108 | /* |
c0ff4b85 | 3109 | * even after unlock, we have memcg->res.usage here and this memcg |
f75ca962 KH |
3110 | * will never be freed. |
3111 | */ | |
c0ff4b85 | 3112 | memcg_check_events(memcg, page); |
f75ca962 | 3113 | if (do_swap_account && ctype == MEM_CGROUP_CHARGE_TYPE_SWAPOUT) { |
c0ff4b85 R |
3114 | mem_cgroup_swap_statistics(memcg, true); |
3115 | mem_cgroup_get(memcg); | |
f75ca962 | 3116 | } |
0030f535 JW |
3117 | /* |
3118 | * Migration does not charge the res_counter for the | |
3119 | * replacement page, so leave it alone when phasing out the | |
3120 | * page that is unused after the migration. | |
3121 | */ | |
3122 | if (!end_migration && !mem_cgroup_is_root(memcg)) | |
c0ff4b85 | 3123 | mem_cgroup_do_uncharge(memcg, nr_pages, ctype); |
6d12e2d8 | 3124 | |
c0ff4b85 | 3125 | return memcg; |
d13d1443 KH |
3126 | |
3127 | unlock_out: | |
3128 | unlock_page_cgroup(pc); | |
8c7c6e34 | 3129 | return NULL; |
3c541e14 BS |
3130 | } |
3131 | ||
69029cd5 KH |
3132 | void mem_cgroup_uncharge_page(struct page *page) |
3133 | { | |
52d4b9ac KH |
3134 | /* early check. */ |
3135 | if (page_mapped(page)) | |
3136 | return; | |
40f23a21 | 3137 | VM_BUG_ON(page->mapping && !PageAnon(page)); |
0c59b89c JW |
3138 | if (PageSwapCache(page)) |
3139 | return; | |
0030f535 | 3140 | __mem_cgroup_uncharge_common(page, MEM_CGROUP_CHARGE_TYPE_ANON, false); |
69029cd5 KH |
3141 | } |
3142 | ||
3143 | void mem_cgroup_uncharge_cache_page(struct page *page) | |
3144 | { | |
3145 | VM_BUG_ON(page_mapped(page)); | |
b7abea96 | 3146 | VM_BUG_ON(page->mapping); |
0030f535 | 3147 | __mem_cgroup_uncharge_common(page, MEM_CGROUP_CHARGE_TYPE_CACHE, false); |
69029cd5 KH |
3148 | } |
3149 | ||
569b846d KH |
3150 | /* |
3151 | * Batch_start/batch_end is called in unmap_page_range/invlidate/trucate. | |
3152 | * In that cases, pages are freed continuously and we can expect pages | |
3153 | * are in the same memcg. All these calls itself limits the number of | |
3154 | * pages freed at once, then uncharge_start/end() is called properly. | |
3155 | * This may be called prural(2) times in a context, | |
3156 | */ | |
3157 | ||
3158 | void mem_cgroup_uncharge_start(void) | |
3159 | { | |
3160 | current->memcg_batch.do_batch++; | |
3161 | /* We can do nest. */ | |
3162 | if (current->memcg_batch.do_batch == 1) { | |
3163 | current->memcg_batch.memcg = NULL; | |
7ffd4ca7 JW |
3164 | current->memcg_batch.nr_pages = 0; |
3165 | current->memcg_batch.memsw_nr_pages = 0; | |
569b846d KH |
3166 | } |
3167 | } | |
3168 | ||
3169 | void mem_cgroup_uncharge_end(void) | |
3170 | { | |
3171 | struct memcg_batch_info *batch = ¤t->memcg_batch; | |
3172 | ||
3173 | if (!batch->do_batch) | |
3174 | return; | |
3175 | ||
3176 | batch->do_batch--; | |
3177 | if (batch->do_batch) /* If stacked, do nothing. */ | |
3178 | return; | |
3179 | ||
3180 | if (!batch->memcg) | |
3181 | return; | |
3182 | /* | |
3183 | * This "batch->memcg" is valid without any css_get/put etc... | |
3184 | * bacause we hide charges behind us. | |
3185 | */ | |
7ffd4ca7 JW |
3186 | if (batch->nr_pages) |
3187 | res_counter_uncharge(&batch->memcg->res, | |
3188 | batch->nr_pages * PAGE_SIZE); | |
3189 | if (batch->memsw_nr_pages) | |
3190 | res_counter_uncharge(&batch->memcg->memsw, | |
3191 | batch->memsw_nr_pages * PAGE_SIZE); | |
3c11ecf4 | 3192 | memcg_oom_recover(batch->memcg); |
569b846d KH |
3193 | /* forget this pointer (for sanity check) */ |
3194 | batch->memcg = NULL; | |
3195 | } | |
3196 | ||
e767e056 | 3197 | #ifdef CONFIG_SWAP |
8c7c6e34 | 3198 | /* |
e767e056 | 3199 | * called after __delete_from_swap_cache() and drop "page" account. |
8c7c6e34 KH |
3200 | * memcg information is recorded to swap_cgroup of "ent" |
3201 | */ | |
8a9478ca KH |
3202 | void |
3203 | mem_cgroup_uncharge_swapcache(struct page *page, swp_entry_t ent, bool swapout) | |
8c7c6e34 KH |
3204 | { |
3205 | struct mem_cgroup *memcg; | |
8a9478ca KH |
3206 | int ctype = MEM_CGROUP_CHARGE_TYPE_SWAPOUT; |
3207 | ||
3208 | if (!swapout) /* this was a swap cache but the swap is unused ! */ | |
3209 | ctype = MEM_CGROUP_CHARGE_TYPE_DROP; | |
3210 | ||
0030f535 | 3211 | memcg = __mem_cgroup_uncharge_common(page, ctype, false); |
8c7c6e34 | 3212 | |
f75ca962 KH |
3213 | /* |
3214 | * record memcg information, if swapout && memcg != NULL, | |
3215 | * mem_cgroup_get() was called in uncharge(). | |
3216 | */ | |
3217 | if (do_swap_account && swapout && memcg) | |
a3b2d692 | 3218 | swap_cgroup_record(ent, css_id(&memcg->css)); |
8c7c6e34 | 3219 | } |
e767e056 | 3220 | #endif |
8c7c6e34 | 3221 | |
c255a458 | 3222 | #ifdef CONFIG_MEMCG_SWAP |
8c7c6e34 KH |
3223 | /* |
3224 | * called from swap_entry_free(). remove record in swap_cgroup and | |
3225 | * uncharge "memsw" account. | |
3226 | */ | |
3227 | void mem_cgroup_uncharge_swap(swp_entry_t ent) | |
d13d1443 | 3228 | { |
8c7c6e34 | 3229 | struct mem_cgroup *memcg; |
a3b2d692 | 3230 | unsigned short id; |
8c7c6e34 KH |
3231 | |
3232 | if (!do_swap_account) | |
3233 | return; | |
3234 | ||
a3b2d692 KH |
3235 | id = swap_cgroup_record(ent, 0); |
3236 | rcu_read_lock(); | |
3237 | memcg = mem_cgroup_lookup(id); | |
8c7c6e34 | 3238 | if (memcg) { |
a3b2d692 KH |
3239 | /* |
3240 | * We uncharge this because swap is freed. | |
3241 | * This memcg can be obsolete one. We avoid calling css_tryget | |
3242 | */ | |
0c3e73e8 | 3243 | if (!mem_cgroup_is_root(memcg)) |
4e649152 | 3244 | res_counter_uncharge(&memcg->memsw, PAGE_SIZE); |
0c3e73e8 | 3245 | mem_cgroup_swap_statistics(memcg, false); |
8c7c6e34 KH |
3246 | mem_cgroup_put(memcg); |
3247 | } | |
a3b2d692 | 3248 | rcu_read_unlock(); |
d13d1443 | 3249 | } |
02491447 DN |
3250 | |
3251 | /** | |
3252 | * mem_cgroup_move_swap_account - move swap charge and swap_cgroup's record. | |
3253 | * @entry: swap entry to be moved | |
3254 | * @from: mem_cgroup which the entry is moved from | |
3255 | * @to: mem_cgroup which the entry is moved to | |
3256 | * | |
3257 | * It succeeds only when the swap_cgroup's record for this entry is the same | |
3258 | * as the mem_cgroup's id of @from. | |
3259 | * | |
3260 | * Returns 0 on success, -EINVAL on failure. | |
3261 | * | |
3262 | * The caller must have charged to @to, IOW, called res_counter_charge() about | |
3263 | * both res and memsw, and called css_get(). | |
3264 | */ | |
3265 | static int mem_cgroup_move_swap_account(swp_entry_t entry, | |
e91cbb42 | 3266 | struct mem_cgroup *from, struct mem_cgroup *to) |
02491447 DN |
3267 | { |
3268 | unsigned short old_id, new_id; | |
3269 | ||
3270 | old_id = css_id(&from->css); | |
3271 | new_id = css_id(&to->css); | |
3272 | ||
3273 | if (swap_cgroup_cmpxchg(entry, old_id, new_id) == old_id) { | |
02491447 | 3274 | mem_cgroup_swap_statistics(from, false); |
483c30b5 | 3275 | mem_cgroup_swap_statistics(to, true); |
02491447 | 3276 | /* |
483c30b5 DN |
3277 | * This function is only called from task migration context now. |
3278 | * It postpones res_counter and refcount handling till the end | |
3279 | * of task migration(mem_cgroup_clear_mc()) for performance | |
3280 | * improvement. But we cannot postpone mem_cgroup_get(to) | |
3281 | * because if the process that has been moved to @to does | |
3282 | * swap-in, the refcount of @to might be decreased to 0. | |
02491447 | 3283 | */ |
02491447 | 3284 | mem_cgroup_get(to); |
02491447 DN |
3285 | return 0; |
3286 | } | |
3287 | return -EINVAL; | |
3288 | } | |
3289 | #else | |
3290 | static inline int mem_cgroup_move_swap_account(swp_entry_t entry, | |
e91cbb42 | 3291 | struct mem_cgroup *from, struct mem_cgroup *to) |
02491447 DN |
3292 | { |
3293 | return -EINVAL; | |
3294 | } | |
8c7c6e34 | 3295 | #endif |
d13d1443 | 3296 | |
ae41be37 | 3297 | /* |
01b1ae63 KH |
3298 | * Before starting migration, account PAGE_SIZE to mem_cgroup that the old |
3299 | * page belongs to. | |
ae41be37 | 3300 | */ |
0030f535 JW |
3301 | void mem_cgroup_prepare_migration(struct page *page, struct page *newpage, |
3302 | struct mem_cgroup **memcgp) | |
ae41be37 | 3303 | { |
c0ff4b85 | 3304 | struct mem_cgroup *memcg = NULL; |
b32967ff | 3305 | unsigned int nr_pages = 1; |
7ec99d62 | 3306 | struct page_cgroup *pc; |
ac39cf8c | 3307 | enum charge_type ctype; |
8869b8f6 | 3308 | |
72835c86 | 3309 | *memcgp = NULL; |
56039efa | 3310 | |
f8d66542 | 3311 | if (mem_cgroup_disabled()) |
0030f535 | 3312 | return; |
4077960e | 3313 | |
b32967ff MG |
3314 | if (PageTransHuge(page)) |
3315 | nr_pages <<= compound_order(page); | |
3316 | ||
52d4b9ac KH |
3317 | pc = lookup_page_cgroup(page); |
3318 | lock_page_cgroup(pc); | |
3319 | if (PageCgroupUsed(pc)) { | |
c0ff4b85 R |
3320 | memcg = pc->mem_cgroup; |
3321 | css_get(&memcg->css); | |
ac39cf8c AM |
3322 | /* |
3323 | * At migrating an anonymous page, its mapcount goes down | |
3324 | * to 0 and uncharge() will be called. But, even if it's fully | |
3325 | * unmapped, migration may fail and this page has to be | |
3326 | * charged again. We set MIGRATION flag here and delay uncharge | |
3327 | * until end_migration() is called | |
3328 | * | |
3329 | * Corner Case Thinking | |
3330 | * A) | |
3331 | * When the old page was mapped as Anon and it's unmap-and-freed | |
3332 | * while migration was ongoing. | |
3333 | * If unmap finds the old page, uncharge() of it will be delayed | |
3334 | * until end_migration(). If unmap finds a new page, it's | |
3335 | * uncharged when it make mapcount to be 1->0. If unmap code | |
3336 | * finds swap_migration_entry, the new page will not be mapped | |
3337 | * and end_migration() will find it(mapcount==0). | |
3338 | * | |
3339 | * B) | |
3340 | * When the old page was mapped but migraion fails, the kernel | |
3341 | * remaps it. A charge for it is kept by MIGRATION flag even | |
3342 | * if mapcount goes down to 0. We can do remap successfully | |
3343 | * without charging it again. | |
3344 | * | |
3345 | * C) | |
3346 | * The "old" page is under lock_page() until the end of | |
3347 | * migration, so, the old page itself will not be swapped-out. | |
3348 | * If the new page is swapped out before end_migraton, our | |
3349 | * hook to usual swap-out path will catch the event. | |
3350 | */ | |
3351 | if (PageAnon(page)) | |
3352 | SetPageCgroupMigration(pc); | |
e8589cc1 | 3353 | } |
52d4b9ac | 3354 | unlock_page_cgroup(pc); |
ac39cf8c AM |
3355 | /* |
3356 | * If the page is not charged at this point, | |
3357 | * we return here. | |
3358 | */ | |
c0ff4b85 | 3359 | if (!memcg) |
0030f535 | 3360 | return; |
01b1ae63 | 3361 | |
72835c86 | 3362 | *memcgp = memcg; |
ac39cf8c AM |
3363 | /* |
3364 | * We charge new page before it's used/mapped. So, even if unlock_page() | |
3365 | * is called before end_migration, we can catch all events on this new | |
3366 | * page. In the case new page is migrated but not remapped, new page's | |
3367 | * mapcount will be finally 0 and we call uncharge in end_migration(). | |
3368 | */ | |
ac39cf8c | 3369 | if (PageAnon(page)) |
41326c17 | 3370 | ctype = MEM_CGROUP_CHARGE_TYPE_ANON; |
ac39cf8c | 3371 | else |
62ba7442 | 3372 | ctype = MEM_CGROUP_CHARGE_TYPE_CACHE; |
0030f535 JW |
3373 | /* |
3374 | * The page is committed to the memcg, but it's not actually | |
3375 | * charged to the res_counter since we plan on replacing the | |
3376 | * old one and only one page is going to be left afterwards. | |
3377 | */ | |
b32967ff | 3378 | __mem_cgroup_commit_charge(memcg, newpage, nr_pages, ctype, false); |
ae41be37 | 3379 | } |
8869b8f6 | 3380 | |
69029cd5 | 3381 | /* remove redundant charge if migration failed*/ |
c0ff4b85 | 3382 | void mem_cgroup_end_migration(struct mem_cgroup *memcg, |
50de1dd9 | 3383 | struct page *oldpage, struct page *newpage, bool migration_ok) |
ae41be37 | 3384 | { |
ac39cf8c | 3385 | struct page *used, *unused; |
01b1ae63 | 3386 | struct page_cgroup *pc; |
b2402857 | 3387 | bool anon; |
01b1ae63 | 3388 | |
c0ff4b85 | 3389 | if (!memcg) |
01b1ae63 | 3390 | return; |
b25ed609 | 3391 | |
50de1dd9 | 3392 | if (!migration_ok) { |
ac39cf8c AM |
3393 | used = oldpage; |
3394 | unused = newpage; | |
01b1ae63 | 3395 | } else { |
ac39cf8c | 3396 | used = newpage; |
01b1ae63 KH |
3397 | unused = oldpage; |
3398 | } | |
0030f535 | 3399 | anon = PageAnon(used); |
7d188958 JW |
3400 | __mem_cgroup_uncharge_common(unused, |
3401 | anon ? MEM_CGROUP_CHARGE_TYPE_ANON | |
3402 | : MEM_CGROUP_CHARGE_TYPE_CACHE, | |
3403 | true); | |
0030f535 | 3404 | css_put(&memcg->css); |
69029cd5 | 3405 | /* |
ac39cf8c AM |
3406 | * We disallowed uncharge of pages under migration because mapcount |
3407 | * of the page goes down to zero, temporarly. | |
3408 | * Clear the flag and check the page should be charged. | |
01b1ae63 | 3409 | */ |
ac39cf8c AM |
3410 | pc = lookup_page_cgroup(oldpage); |
3411 | lock_page_cgroup(pc); | |
3412 | ClearPageCgroupMigration(pc); | |
3413 | unlock_page_cgroup(pc); | |
ac39cf8c | 3414 | |
01b1ae63 | 3415 | /* |
ac39cf8c AM |
3416 | * If a page is a file cache, radix-tree replacement is very atomic |
3417 | * and we can skip this check. When it was an Anon page, its mapcount | |
3418 | * goes down to 0. But because we added MIGRATION flage, it's not | |
3419 | * uncharged yet. There are several case but page->mapcount check | |
3420 | * and USED bit check in mem_cgroup_uncharge_page() will do enough | |
3421 | * check. (see prepare_charge() also) | |
69029cd5 | 3422 | */ |
b2402857 | 3423 | if (anon) |
ac39cf8c | 3424 | mem_cgroup_uncharge_page(used); |
ae41be37 | 3425 | } |
78fb7466 | 3426 | |
ab936cbc KH |
3427 | /* |
3428 | * At replace page cache, newpage is not under any memcg but it's on | |
3429 | * LRU. So, this function doesn't touch res_counter but handles LRU | |
3430 | * in correct way. Both pages are locked so we cannot race with uncharge. | |
3431 | */ | |
3432 | void mem_cgroup_replace_page_cache(struct page *oldpage, | |
3433 | struct page *newpage) | |
3434 | { | |
bde05d1c | 3435 | struct mem_cgroup *memcg = NULL; |
ab936cbc | 3436 | struct page_cgroup *pc; |
ab936cbc | 3437 | enum charge_type type = MEM_CGROUP_CHARGE_TYPE_CACHE; |
ab936cbc KH |
3438 | |
3439 | if (mem_cgroup_disabled()) | |
3440 | return; | |
3441 | ||
3442 | pc = lookup_page_cgroup(oldpage); | |
3443 | /* fix accounting on old pages */ | |
3444 | lock_page_cgroup(pc); | |
bde05d1c HD |
3445 | if (PageCgroupUsed(pc)) { |
3446 | memcg = pc->mem_cgroup; | |
3447 | mem_cgroup_charge_statistics(memcg, false, -1); | |
3448 | ClearPageCgroupUsed(pc); | |
3449 | } | |
ab936cbc KH |
3450 | unlock_page_cgroup(pc); |
3451 | ||
bde05d1c HD |
3452 | /* |
3453 | * When called from shmem_replace_page(), in some cases the | |
3454 | * oldpage has already been charged, and in some cases not. | |
3455 | */ | |
3456 | if (!memcg) | |
3457 | return; | |
ab936cbc KH |
3458 | /* |
3459 | * Even if newpage->mapping was NULL before starting replacement, | |
3460 | * the newpage may be on LRU(or pagevec for LRU) already. We lock | |
3461 | * LRU while we overwrite pc->mem_cgroup. | |
3462 | */ | |
ce587e65 | 3463 | __mem_cgroup_commit_charge(memcg, newpage, 1, type, true); |
ab936cbc KH |
3464 | } |
3465 | ||
f212ad7c DN |
3466 | #ifdef CONFIG_DEBUG_VM |
3467 | static struct page_cgroup *lookup_page_cgroup_used(struct page *page) | |
3468 | { | |
3469 | struct page_cgroup *pc; | |
3470 | ||
3471 | pc = lookup_page_cgroup(page); | |
cfa44946 JW |
3472 | /* |
3473 | * Can be NULL while feeding pages into the page allocator for | |
3474 | * the first time, i.e. during boot or memory hotplug; | |
3475 | * or when mem_cgroup_disabled(). | |
3476 | */ | |
f212ad7c DN |
3477 | if (likely(pc) && PageCgroupUsed(pc)) |
3478 | return pc; | |
3479 | return NULL; | |
3480 | } | |
3481 | ||
3482 | bool mem_cgroup_bad_page_check(struct page *page) | |
3483 | { | |
3484 | if (mem_cgroup_disabled()) | |
3485 | return false; | |
3486 | ||
3487 | return lookup_page_cgroup_used(page) != NULL; | |
3488 | } | |
3489 | ||
3490 | void mem_cgroup_print_bad_page(struct page *page) | |
3491 | { | |
3492 | struct page_cgroup *pc; | |
3493 | ||
3494 | pc = lookup_page_cgroup_used(page); | |
3495 | if (pc) { | |
90b3feae | 3496 | printk(KERN_ALERT "pc:%p pc->flags:%lx pc->mem_cgroup:%p\n", |
f212ad7c | 3497 | pc, pc->flags, pc->mem_cgroup); |
f212ad7c DN |
3498 | } |
3499 | } | |
3500 | #endif | |
3501 | ||
8c7c6e34 KH |
3502 | static DEFINE_MUTEX(set_limit_mutex); |
3503 | ||
d38d2a75 | 3504 | static int mem_cgroup_resize_limit(struct mem_cgroup *memcg, |
8c7c6e34 | 3505 | unsigned long long val) |
628f4235 | 3506 | { |
81d39c20 | 3507 | int retry_count; |
3c11ecf4 | 3508 | u64 memswlimit, memlimit; |
628f4235 | 3509 | int ret = 0; |
81d39c20 KH |
3510 | int children = mem_cgroup_count_children(memcg); |
3511 | u64 curusage, oldusage; | |
3c11ecf4 | 3512 | int enlarge; |
81d39c20 KH |
3513 | |
3514 | /* | |
3515 | * For keeping hierarchical_reclaim simple, how long we should retry | |
3516 | * is depends on callers. We set our retry-count to be function | |
3517 | * of # of children which we should visit in this loop. | |
3518 | */ | |
3519 | retry_count = MEM_CGROUP_RECLAIM_RETRIES * children; | |
3520 | ||
3521 | oldusage = res_counter_read_u64(&memcg->res, RES_USAGE); | |
628f4235 | 3522 | |
3c11ecf4 | 3523 | enlarge = 0; |
8c7c6e34 | 3524 | while (retry_count) { |
628f4235 KH |
3525 | if (signal_pending(current)) { |
3526 | ret = -EINTR; | |
3527 | break; | |
3528 | } | |
8c7c6e34 KH |
3529 | /* |
3530 | * Rather than hide all in some function, I do this in | |
3531 | * open coded manner. You see what this really does. | |
aaad153e | 3532 | * We have to guarantee memcg->res.limit <= memcg->memsw.limit. |
8c7c6e34 KH |
3533 | */ |
3534 | mutex_lock(&set_limit_mutex); | |
3535 | memswlimit = res_counter_read_u64(&memcg->memsw, RES_LIMIT); | |
3536 | if (memswlimit < val) { | |
3537 | ret = -EINVAL; | |
3538 | mutex_unlock(&set_limit_mutex); | |
628f4235 KH |
3539 | break; |
3540 | } | |
3c11ecf4 KH |
3541 | |
3542 | memlimit = res_counter_read_u64(&memcg->res, RES_LIMIT); | |
3543 | if (memlimit < val) | |
3544 | enlarge = 1; | |
3545 | ||
8c7c6e34 | 3546 | ret = res_counter_set_limit(&memcg->res, val); |
22a668d7 KH |
3547 | if (!ret) { |
3548 | if (memswlimit == val) | |
3549 | memcg->memsw_is_minimum = true; | |
3550 | else | |
3551 | memcg->memsw_is_minimum = false; | |
3552 | } | |
8c7c6e34 KH |
3553 | mutex_unlock(&set_limit_mutex); |
3554 | ||
3555 | if (!ret) | |
3556 | break; | |
3557 | ||
5660048c JW |
3558 | mem_cgroup_reclaim(memcg, GFP_KERNEL, |
3559 | MEM_CGROUP_RECLAIM_SHRINK); | |
81d39c20 KH |
3560 | curusage = res_counter_read_u64(&memcg->res, RES_USAGE); |
3561 | /* Usage is reduced ? */ | |
3562 | if (curusage >= oldusage) | |
3563 | retry_count--; | |
3564 | else | |
3565 | oldusage = curusage; | |
8c7c6e34 | 3566 | } |
3c11ecf4 KH |
3567 | if (!ret && enlarge) |
3568 | memcg_oom_recover(memcg); | |
14797e23 | 3569 | |
8c7c6e34 KH |
3570 | return ret; |
3571 | } | |
3572 | ||
338c8431 LZ |
3573 | static int mem_cgroup_resize_memsw_limit(struct mem_cgroup *memcg, |
3574 | unsigned long long val) | |
8c7c6e34 | 3575 | { |
81d39c20 | 3576 | int retry_count; |
3c11ecf4 | 3577 | u64 memlimit, memswlimit, oldusage, curusage; |
81d39c20 KH |
3578 | int children = mem_cgroup_count_children(memcg); |
3579 | int ret = -EBUSY; | |
3c11ecf4 | 3580 | int enlarge = 0; |
8c7c6e34 | 3581 | |
81d39c20 KH |
3582 | /* see mem_cgroup_resize_res_limit */ |
3583 | retry_count = children * MEM_CGROUP_RECLAIM_RETRIES; | |
3584 | oldusage = res_counter_read_u64(&memcg->memsw, RES_USAGE); | |
8c7c6e34 KH |
3585 | while (retry_count) { |
3586 | if (signal_pending(current)) { | |
3587 | ret = -EINTR; | |
3588 | break; | |
3589 | } | |
3590 | /* | |
3591 | * Rather than hide all in some function, I do this in | |
3592 | * open coded manner. You see what this really does. | |
aaad153e | 3593 | * We have to guarantee memcg->res.limit <= memcg->memsw.limit. |
8c7c6e34 KH |
3594 | */ |
3595 | mutex_lock(&set_limit_mutex); | |
3596 | memlimit = res_counter_read_u64(&memcg->res, RES_LIMIT); | |
3597 | if (memlimit > val) { | |
3598 | ret = -EINVAL; | |
3599 | mutex_unlock(&set_limit_mutex); | |
3600 | break; | |
3601 | } | |
3c11ecf4 KH |
3602 | memswlimit = res_counter_read_u64(&memcg->memsw, RES_LIMIT); |
3603 | if (memswlimit < val) | |
3604 | enlarge = 1; | |
8c7c6e34 | 3605 | ret = res_counter_set_limit(&memcg->memsw, val); |
22a668d7 KH |
3606 | if (!ret) { |
3607 | if (memlimit == val) | |
3608 | memcg->memsw_is_minimum = true; | |
3609 | else | |
3610 | memcg->memsw_is_minimum = false; | |
3611 | } | |
8c7c6e34 KH |
3612 | mutex_unlock(&set_limit_mutex); |
3613 | ||
3614 | if (!ret) | |
3615 | break; | |
3616 | ||
5660048c JW |
3617 | mem_cgroup_reclaim(memcg, GFP_KERNEL, |
3618 | MEM_CGROUP_RECLAIM_NOSWAP | | |
3619 | MEM_CGROUP_RECLAIM_SHRINK); | |
8c7c6e34 | 3620 | curusage = res_counter_read_u64(&memcg->memsw, RES_USAGE); |
81d39c20 | 3621 | /* Usage is reduced ? */ |
8c7c6e34 | 3622 | if (curusage >= oldusage) |
628f4235 | 3623 | retry_count--; |
81d39c20 KH |
3624 | else |
3625 | oldusage = curusage; | |
628f4235 | 3626 | } |
3c11ecf4 KH |
3627 | if (!ret && enlarge) |
3628 | memcg_oom_recover(memcg); | |
628f4235 KH |
3629 | return ret; |
3630 | } | |
3631 | ||
4e416953 | 3632 | unsigned long mem_cgroup_soft_limit_reclaim(struct zone *zone, int order, |
0ae5e89c YH |
3633 | gfp_t gfp_mask, |
3634 | unsigned long *total_scanned) | |
4e416953 BS |
3635 | { |
3636 | unsigned long nr_reclaimed = 0; | |
3637 | struct mem_cgroup_per_zone *mz, *next_mz = NULL; | |
3638 | unsigned long reclaimed; | |
3639 | int loop = 0; | |
3640 | struct mem_cgroup_tree_per_zone *mctz; | |
ef8745c1 | 3641 | unsigned long long excess; |
0ae5e89c | 3642 | unsigned long nr_scanned; |
4e416953 BS |
3643 | |
3644 | if (order > 0) | |
3645 | return 0; | |
3646 | ||
00918b6a | 3647 | mctz = soft_limit_tree_node_zone(zone_to_nid(zone), zone_idx(zone)); |
4e416953 BS |
3648 | /* |
3649 | * This loop can run a while, specially if mem_cgroup's continuously | |
3650 | * keep exceeding their soft limit and putting the system under | |
3651 | * pressure | |
3652 | */ | |
3653 | do { | |
3654 | if (next_mz) | |
3655 | mz = next_mz; | |
3656 | else | |
3657 | mz = mem_cgroup_largest_soft_limit_node(mctz); | |
3658 | if (!mz) | |
3659 | break; | |
3660 | ||
0ae5e89c | 3661 | nr_scanned = 0; |
d79154bb | 3662 | reclaimed = mem_cgroup_soft_reclaim(mz->memcg, zone, |
5660048c | 3663 | gfp_mask, &nr_scanned); |
4e416953 | 3664 | nr_reclaimed += reclaimed; |
0ae5e89c | 3665 | *total_scanned += nr_scanned; |
4e416953 BS |
3666 | spin_lock(&mctz->lock); |
3667 | ||
3668 | /* | |
3669 | * If we failed to reclaim anything from this memory cgroup | |
3670 | * it is time to move on to the next cgroup | |
3671 | */ | |
3672 | next_mz = NULL; | |
3673 | if (!reclaimed) { | |
3674 | do { | |
3675 | /* | |
3676 | * Loop until we find yet another one. | |
3677 | * | |
3678 | * By the time we get the soft_limit lock | |
3679 | * again, someone might have aded the | |
3680 | * group back on the RB tree. Iterate to | |
3681 | * make sure we get a different mem. | |
3682 | * mem_cgroup_largest_soft_limit_node returns | |
3683 | * NULL if no other cgroup is present on | |
3684 | * the tree | |
3685 | */ | |
3686 | next_mz = | |
3687 | __mem_cgroup_largest_soft_limit_node(mctz); | |
39cc98f1 | 3688 | if (next_mz == mz) |
d79154bb | 3689 | css_put(&next_mz->memcg->css); |
39cc98f1 | 3690 | else /* next_mz == NULL or other memcg */ |
4e416953 BS |
3691 | break; |
3692 | } while (1); | |
3693 | } | |
d79154bb HD |
3694 | __mem_cgroup_remove_exceeded(mz->memcg, mz, mctz); |
3695 | excess = res_counter_soft_limit_excess(&mz->memcg->res); | |
4e416953 BS |
3696 | /* |
3697 | * One school of thought says that we should not add | |
3698 | * back the node to the tree if reclaim returns 0. | |
3699 | * But our reclaim could return 0, simply because due | |
3700 | * to priority we are exposing a smaller subset of | |
3701 | * memory to reclaim from. Consider this as a longer | |
3702 | * term TODO. | |
3703 | */ | |
ef8745c1 | 3704 | /* If excess == 0, no tree ops */ |
d79154bb | 3705 | __mem_cgroup_insert_exceeded(mz->memcg, mz, mctz, excess); |
4e416953 | 3706 | spin_unlock(&mctz->lock); |
d79154bb | 3707 | css_put(&mz->memcg->css); |
4e416953 BS |
3708 | loop++; |
3709 | /* | |
3710 | * Could not reclaim anything and there are no more | |
3711 | * mem cgroups to try or we seem to be looping without | |
3712 | * reclaiming anything. | |
3713 | */ | |
3714 | if (!nr_reclaimed && | |
3715 | (next_mz == NULL || | |
3716 | loop > MEM_CGROUP_MAX_SOFT_LIMIT_RECLAIM_LOOPS)) | |
3717 | break; | |
3718 | } while (!nr_reclaimed); | |
3719 | if (next_mz) | |
d79154bb | 3720 | css_put(&next_mz->memcg->css); |
4e416953 BS |
3721 | return nr_reclaimed; |
3722 | } | |
3723 | ||
2ef37d3f MH |
3724 | /** |
3725 | * mem_cgroup_force_empty_list - clears LRU of a group | |
3726 | * @memcg: group to clear | |
3727 | * @node: NUMA node | |
3728 | * @zid: zone id | |
3729 | * @lru: lru to to clear | |
3730 | * | |
3c935d18 | 3731 | * Traverse a specified page_cgroup list and try to drop them all. This doesn't |
2ef37d3f MH |
3732 | * reclaim the pages page themselves - pages are moved to the parent (or root) |
3733 | * group. | |
cc847582 | 3734 | */ |
2ef37d3f | 3735 | static void mem_cgroup_force_empty_list(struct mem_cgroup *memcg, |
08e552c6 | 3736 | int node, int zid, enum lru_list lru) |
cc847582 | 3737 | { |
bea8c150 | 3738 | struct lruvec *lruvec; |
2ef37d3f | 3739 | unsigned long flags; |
072c56c1 | 3740 | struct list_head *list; |
925b7673 JW |
3741 | struct page *busy; |
3742 | struct zone *zone; | |
072c56c1 | 3743 | |
08e552c6 | 3744 | zone = &NODE_DATA(node)->node_zones[zid]; |
bea8c150 HD |
3745 | lruvec = mem_cgroup_zone_lruvec(zone, memcg); |
3746 | list = &lruvec->lists[lru]; | |
cc847582 | 3747 | |
f817ed48 | 3748 | busy = NULL; |
2ef37d3f | 3749 | do { |
925b7673 | 3750 | struct page_cgroup *pc; |
5564e88b JW |
3751 | struct page *page; |
3752 | ||
08e552c6 | 3753 | spin_lock_irqsave(&zone->lru_lock, flags); |
f817ed48 | 3754 | if (list_empty(list)) { |
08e552c6 | 3755 | spin_unlock_irqrestore(&zone->lru_lock, flags); |
52d4b9ac | 3756 | break; |
f817ed48 | 3757 | } |
925b7673 JW |
3758 | page = list_entry(list->prev, struct page, lru); |
3759 | if (busy == page) { | |
3760 | list_move(&page->lru, list); | |
648bcc77 | 3761 | busy = NULL; |
08e552c6 | 3762 | spin_unlock_irqrestore(&zone->lru_lock, flags); |
f817ed48 KH |
3763 | continue; |
3764 | } | |
08e552c6 | 3765 | spin_unlock_irqrestore(&zone->lru_lock, flags); |
f817ed48 | 3766 | |
925b7673 | 3767 | pc = lookup_page_cgroup(page); |
5564e88b | 3768 | |
3c935d18 | 3769 | if (mem_cgroup_move_parent(page, pc, memcg)) { |
f817ed48 | 3770 | /* found lock contention or "pc" is obsolete. */ |
925b7673 | 3771 | busy = page; |
f817ed48 KH |
3772 | cond_resched(); |
3773 | } else | |
3774 | busy = NULL; | |
2ef37d3f | 3775 | } while (!list_empty(list)); |
cc847582 KH |
3776 | } |
3777 | ||
3778 | /* | |
c26251f9 MH |
3779 | * make mem_cgroup's charge to be 0 if there is no task by moving |
3780 | * all the charges and pages to the parent. | |
cc847582 | 3781 | * This enables deleting this mem_cgroup. |
c26251f9 MH |
3782 | * |
3783 | * Caller is responsible for holding css reference on the memcg. | |
cc847582 | 3784 | */ |
ab5196c2 | 3785 | static void mem_cgroup_reparent_charges(struct mem_cgroup *memcg) |
cc847582 | 3786 | { |
c26251f9 | 3787 | int node, zid; |
f817ed48 | 3788 | |
fce66477 | 3789 | do { |
52d4b9ac KH |
3790 | /* This is for making all *used* pages to be on LRU. */ |
3791 | lru_add_drain_all(); | |
c0ff4b85 | 3792 | drain_all_stock_sync(memcg); |
c0ff4b85 | 3793 | mem_cgroup_start_move(memcg); |
31aaea4a | 3794 | for_each_node_state(node, N_MEMORY) { |
2ef37d3f | 3795 | for (zid = 0; zid < MAX_NR_ZONES; zid++) { |
f156ab93 HD |
3796 | enum lru_list lru; |
3797 | for_each_lru(lru) { | |
2ef37d3f | 3798 | mem_cgroup_force_empty_list(memcg, |
f156ab93 | 3799 | node, zid, lru); |
f817ed48 | 3800 | } |
1ecaab2b | 3801 | } |
f817ed48 | 3802 | } |
c0ff4b85 R |
3803 | mem_cgroup_end_move(memcg); |
3804 | memcg_oom_recover(memcg); | |
52d4b9ac | 3805 | cond_resched(); |
f817ed48 | 3806 | |
2ef37d3f MH |
3807 | /* |
3808 | * This is a safety check because mem_cgroup_force_empty_list | |
3809 | * could have raced with mem_cgroup_replace_page_cache callers | |
3810 | * so the lru seemed empty but the page could have been added | |
3811 | * right after the check. RES_USAGE should be safe as we always | |
3812 | * charge before adding to the LRU. | |
3813 | */ | |
3814 | } while (res_counter_read_u64(&memcg->res, RES_USAGE) > 0); | |
c26251f9 MH |
3815 | } |
3816 | ||
3817 | /* | |
3818 | * Reclaims as many pages from the given memcg as possible and moves | |
3819 | * the rest to the parent. | |
3820 | * | |
3821 | * Caller is responsible for holding css reference for memcg. | |
3822 | */ | |
3823 | static int mem_cgroup_force_empty(struct mem_cgroup *memcg) | |
3824 | { | |
3825 | int nr_retries = MEM_CGROUP_RECLAIM_RETRIES; | |
3826 | struct cgroup *cgrp = memcg->css.cgroup; | |
f817ed48 | 3827 | |
c1e862c1 | 3828 | /* returns EBUSY if there is a task or if we come here twice. */ |
c26251f9 MH |
3829 | if (cgroup_task_count(cgrp) || !list_empty(&cgrp->children)) |
3830 | return -EBUSY; | |
3831 | ||
c1e862c1 KH |
3832 | /* we call try-to-free pages for make this cgroup empty */ |
3833 | lru_add_drain_all(); | |
f817ed48 | 3834 | /* try to free all pages in this cgroup */ |
569530fb | 3835 | while (nr_retries && res_counter_read_u64(&memcg->res, RES_USAGE) > 0) { |
f817ed48 | 3836 | int progress; |
c1e862c1 | 3837 | |
c26251f9 MH |
3838 | if (signal_pending(current)) |
3839 | return -EINTR; | |
3840 | ||
c0ff4b85 | 3841 | progress = try_to_free_mem_cgroup_pages(memcg, GFP_KERNEL, |
185efc0f | 3842 | false); |
c1e862c1 | 3843 | if (!progress) { |
f817ed48 | 3844 | nr_retries--; |
c1e862c1 | 3845 | /* maybe some writeback is necessary */ |
8aa7e847 | 3846 | congestion_wait(BLK_RW_ASYNC, HZ/10); |
c1e862c1 | 3847 | } |
f817ed48 KH |
3848 | |
3849 | } | |
08e552c6 | 3850 | lru_add_drain(); |
ab5196c2 MH |
3851 | mem_cgroup_reparent_charges(memcg); |
3852 | ||
3853 | return 0; | |
cc847582 KH |
3854 | } |
3855 | ||
6bbda35c | 3856 | static int mem_cgroup_force_empty_write(struct cgroup *cont, unsigned int event) |
c1e862c1 | 3857 | { |
c26251f9 MH |
3858 | struct mem_cgroup *memcg = mem_cgroup_from_cont(cont); |
3859 | int ret; | |
3860 | ||
d8423011 MH |
3861 | if (mem_cgroup_is_root(memcg)) |
3862 | return -EINVAL; | |
c26251f9 MH |
3863 | css_get(&memcg->css); |
3864 | ret = mem_cgroup_force_empty(memcg); | |
3865 | css_put(&memcg->css); | |
3866 | ||
3867 | return ret; | |
c1e862c1 KH |
3868 | } |
3869 | ||
3870 | ||
18f59ea7 BS |
3871 | static u64 mem_cgroup_hierarchy_read(struct cgroup *cont, struct cftype *cft) |
3872 | { | |
3873 | return mem_cgroup_from_cont(cont)->use_hierarchy; | |
3874 | } | |
3875 | ||
3876 | static int mem_cgroup_hierarchy_write(struct cgroup *cont, struct cftype *cft, | |
3877 | u64 val) | |
3878 | { | |
3879 | int retval = 0; | |
c0ff4b85 | 3880 | struct mem_cgroup *memcg = mem_cgroup_from_cont(cont); |
18f59ea7 | 3881 | struct cgroup *parent = cont->parent; |
c0ff4b85 | 3882 | struct mem_cgroup *parent_memcg = NULL; |
18f59ea7 BS |
3883 | |
3884 | if (parent) | |
c0ff4b85 | 3885 | parent_memcg = mem_cgroup_from_cont(parent); |
18f59ea7 BS |
3886 | |
3887 | cgroup_lock(); | |
567fb435 GC |
3888 | |
3889 | if (memcg->use_hierarchy == val) | |
3890 | goto out; | |
3891 | ||
18f59ea7 | 3892 | /* |
af901ca1 | 3893 | * If parent's use_hierarchy is set, we can't make any modifications |
18f59ea7 BS |
3894 | * in the child subtrees. If it is unset, then the change can |
3895 | * occur, provided the current cgroup has no children. | |
3896 | * | |
3897 | * For the root cgroup, parent_mem is NULL, we allow value to be | |
3898 | * set if there are no children. | |
3899 | */ | |
c0ff4b85 | 3900 | if ((!parent_memcg || !parent_memcg->use_hierarchy) && |
18f59ea7 BS |
3901 | (val == 1 || val == 0)) { |
3902 | if (list_empty(&cont->children)) | |
c0ff4b85 | 3903 | memcg->use_hierarchy = val; |
18f59ea7 BS |
3904 | else |
3905 | retval = -EBUSY; | |
3906 | } else | |
3907 | retval = -EINVAL; | |
567fb435 GC |
3908 | |
3909 | out: | |
18f59ea7 BS |
3910 | cgroup_unlock(); |
3911 | ||
3912 | return retval; | |
3913 | } | |
3914 | ||
0c3e73e8 | 3915 | |
c0ff4b85 | 3916 | static unsigned long mem_cgroup_recursive_stat(struct mem_cgroup *memcg, |
7a159cc9 | 3917 | enum mem_cgroup_stat_index idx) |
0c3e73e8 | 3918 | { |
7d74b06f | 3919 | struct mem_cgroup *iter; |
7a159cc9 | 3920 | long val = 0; |
0c3e73e8 | 3921 | |
7a159cc9 | 3922 | /* Per-cpu values can be negative, use a signed accumulator */ |
c0ff4b85 | 3923 | for_each_mem_cgroup_tree(iter, memcg) |
7d74b06f KH |
3924 | val += mem_cgroup_read_stat(iter, idx); |
3925 | ||
3926 | if (val < 0) /* race ? */ | |
3927 | val = 0; | |
3928 | return val; | |
0c3e73e8 BS |
3929 | } |
3930 | ||
c0ff4b85 | 3931 | static inline u64 mem_cgroup_usage(struct mem_cgroup *memcg, bool swap) |
104f3928 | 3932 | { |
7d74b06f | 3933 | u64 val; |
104f3928 | 3934 | |
c0ff4b85 | 3935 | if (!mem_cgroup_is_root(memcg)) { |
104f3928 | 3936 | if (!swap) |
65c64ce8 | 3937 | return res_counter_read_u64(&memcg->res, RES_USAGE); |
104f3928 | 3938 | else |
65c64ce8 | 3939 | return res_counter_read_u64(&memcg->memsw, RES_USAGE); |
104f3928 KS |
3940 | } |
3941 | ||
c0ff4b85 R |
3942 | val = mem_cgroup_recursive_stat(memcg, MEM_CGROUP_STAT_CACHE); |
3943 | val += mem_cgroup_recursive_stat(memcg, MEM_CGROUP_STAT_RSS); | |
104f3928 | 3944 | |
7d74b06f | 3945 | if (swap) |
bff6bb83 | 3946 | val += mem_cgroup_recursive_stat(memcg, MEM_CGROUP_STAT_SWAP); |
104f3928 KS |
3947 | |
3948 | return val << PAGE_SHIFT; | |
3949 | } | |
3950 | ||
af36f906 TH |
3951 | static ssize_t mem_cgroup_read(struct cgroup *cont, struct cftype *cft, |
3952 | struct file *file, char __user *buf, | |
3953 | size_t nbytes, loff_t *ppos) | |
8cdea7c0 | 3954 | { |
c0ff4b85 | 3955 | struct mem_cgroup *memcg = mem_cgroup_from_cont(cont); |
af36f906 | 3956 | char str[64]; |
104f3928 | 3957 | u64 val; |
86ae53e1 GC |
3958 | int name, len; |
3959 | enum res_type type; | |
8c7c6e34 KH |
3960 | |
3961 | type = MEMFILE_TYPE(cft->private); | |
3962 | name = MEMFILE_ATTR(cft->private); | |
af36f906 TH |
3963 | |
3964 | if (!do_swap_account && type == _MEMSWAP) | |
3965 | return -EOPNOTSUPP; | |
3966 | ||
8c7c6e34 KH |
3967 | switch (type) { |
3968 | case _MEM: | |
104f3928 | 3969 | if (name == RES_USAGE) |
c0ff4b85 | 3970 | val = mem_cgroup_usage(memcg, false); |
104f3928 | 3971 | else |
c0ff4b85 | 3972 | val = res_counter_read_u64(&memcg->res, name); |
8c7c6e34 KH |
3973 | break; |
3974 | case _MEMSWAP: | |
104f3928 | 3975 | if (name == RES_USAGE) |
c0ff4b85 | 3976 | val = mem_cgroup_usage(memcg, true); |
104f3928 | 3977 | else |
c0ff4b85 | 3978 | val = res_counter_read_u64(&memcg->memsw, name); |
8c7c6e34 KH |
3979 | break; |
3980 | default: | |
3981 | BUG(); | |
8c7c6e34 | 3982 | } |
af36f906 TH |
3983 | |
3984 | len = scnprintf(str, sizeof(str), "%llu\n", (unsigned long long)val); | |
3985 | return simple_read_from_buffer(buf, nbytes, ppos, str, len); | |
8cdea7c0 | 3986 | } |
628f4235 KH |
3987 | /* |
3988 | * The user of this function is... | |
3989 | * RES_LIMIT. | |
3990 | */ | |
856c13aa PM |
3991 | static int mem_cgroup_write(struct cgroup *cont, struct cftype *cft, |
3992 | const char *buffer) | |
8cdea7c0 | 3993 | { |
628f4235 | 3994 | struct mem_cgroup *memcg = mem_cgroup_from_cont(cont); |
86ae53e1 GC |
3995 | enum res_type type; |
3996 | int name; | |
628f4235 KH |
3997 | unsigned long long val; |
3998 | int ret; | |
3999 | ||
8c7c6e34 KH |
4000 | type = MEMFILE_TYPE(cft->private); |
4001 | name = MEMFILE_ATTR(cft->private); | |
af36f906 TH |
4002 | |
4003 | if (!do_swap_account && type == _MEMSWAP) | |
4004 | return -EOPNOTSUPP; | |
4005 | ||
8c7c6e34 | 4006 | switch (name) { |
628f4235 | 4007 | case RES_LIMIT: |
4b3bde4c BS |
4008 | if (mem_cgroup_is_root(memcg)) { /* Can't set limit on root */ |
4009 | ret = -EINVAL; | |
4010 | break; | |
4011 | } | |
628f4235 KH |
4012 | /* This function does all necessary parse...reuse it */ |
4013 | ret = res_counter_memparse_write_strategy(buffer, &val); | |
8c7c6e34 KH |
4014 | if (ret) |
4015 | break; | |
4016 | if (type == _MEM) | |
628f4235 | 4017 | ret = mem_cgroup_resize_limit(memcg, val); |
8c7c6e34 KH |
4018 | else |
4019 | ret = mem_cgroup_resize_memsw_limit(memcg, val); | |
628f4235 | 4020 | break; |
296c81d8 BS |
4021 | case RES_SOFT_LIMIT: |
4022 | ret = res_counter_memparse_write_strategy(buffer, &val); | |
4023 | if (ret) | |
4024 | break; | |
4025 | /* | |
4026 | * For memsw, soft limits are hard to implement in terms | |
4027 | * of semantics, for now, we support soft limits for | |
4028 | * control without swap | |
4029 | */ | |
4030 | if (type == _MEM) | |
4031 | ret = res_counter_set_soft_limit(&memcg->res, val); | |
4032 | else | |
4033 | ret = -EINVAL; | |
4034 | break; | |
628f4235 KH |
4035 | default: |
4036 | ret = -EINVAL; /* should be BUG() ? */ | |
4037 | break; | |
4038 | } | |
4039 | return ret; | |
8cdea7c0 BS |
4040 | } |
4041 | ||
fee7b548 KH |
4042 | static void memcg_get_hierarchical_limit(struct mem_cgroup *memcg, |
4043 | unsigned long long *mem_limit, unsigned long long *memsw_limit) | |
4044 | { | |
4045 | struct cgroup *cgroup; | |
4046 | unsigned long long min_limit, min_memsw_limit, tmp; | |
4047 | ||
4048 | min_limit = res_counter_read_u64(&memcg->res, RES_LIMIT); | |
4049 | min_memsw_limit = res_counter_read_u64(&memcg->memsw, RES_LIMIT); | |
4050 | cgroup = memcg->css.cgroup; | |
4051 | if (!memcg->use_hierarchy) | |
4052 | goto out; | |
4053 | ||
4054 | while (cgroup->parent) { | |
4055 | cgroup = cgroup->parent; | |
4056 | memcg = mem_cgroup_from_cont(cgroup); | |
4057 | if (!memcg->use_hierarchy) | |
4058 | break; | |
4059 | tmp = res_counter_read_u64(&memcg->res, RES_LIMIT); | |
4060 | min_limit = min(min_limit, tmp); | |
4061 | tmp = res_counter_read_u64(&memcg->memsw, RES_LIMIT); | |
4062 | min_memsw_limit = min(min_memsw_limit, tmp); | |
4063 | } | |
4064 | out: | |
4065 | *mem_limit = min_limit; | |
4066 | *memsw_limit = min_memsw_limit; | |
fee7b548 KH |
4067 | } |
4068 | ||
29f2a4da | 4069 | static int mem_cgroup_reset(struct cgroup *cont, unsigned int event) |
c84872e1 | 4070 | { |
af36f906 | 4071 | struct mem_cgroup *memcg = mem_cgroup_from_cont(cont); |
86ae53e1 GC |
4072 | int name; |
4073 | enum res_type type; | |
c84872e1 | 4074 | |
8c7c6e34 KH |
4075 | type = MEMFILE_TYPE(event); |
4076 | name = MEMFILE_ATTR(event); | |
af36f906 TH |
4077 | |
4078 | if (!do_swap_account && type == _MEMSWAP) | |
4079 | return -EOPNOTSUPP; | |
4080 | ||
8c7c6e34 | 4081 | switch (name) { |
29f2a4da | 4082 | case RES_MAX_USAGE: |
8c7c6e34 | 4083 | if (type == _MEM) |
c0ff4b85 | 4084 | res_counter_reset_max(&memcg->res); |
8c7c6e34 | 4085 | else |
c0ff4b85 | 4086 | res_counter_reset_max(&memcg->memsw); |
29f2a4da PE |
4087 | break; |
4088 | case RES_FAILCNT: | |
8c7c6e34 | 4089 | if (type == _MEM) |
c0ff4b85 | 4090 | res_counter_reset_failcnt(&memcg->res); |
8c7c6e34 | 4091 | else |
c0ff4b85 | 4092 | res_counter_reset_failcnt(&memcg->memsw); |
29f2a4da PE |
4093 | break; |
4094 | } | |
f64c3f54 | 4095 | |
85cc59db | 4096 | return 0; |
c84872e1 PE |
4097 | } |
4098 | ||
7dc74be0 DN |
4099 | static u64 mem_cgroup_move_charge_read(struct cgroup *cgrp, |
4100 | struct cftype *cft) | |
4101 | { | |
4102 | return mem_cgroup_from_cont(cgrp)->move_charge_at_immigrate; | |
4103 | } | |
4104 | ||
02491447 | 4105 | #ifdef CONFIG_MMU |
7dc74be0 DN |
4106 | static int mem_cgroup_move_charge_write(struct cgroup *cgrp, |
4107 | struct cftype *cft, u64 val) | |
4108 | { | |
c0ff4b85 | 4109 | struct mem_cgroup *memcg = mem_cgroup_from_cont(cgrp); |
7dc74be0 DN |
4110 | |
4111 | if (val >= (1 << NR_MOVE_TYPE)) | |
4112 | return -EINVAL; | |
4113 | /* | |
4114 | * We check this value several times in both in can_attach() and | |
4115 | * attach(), so we need cgroup lock to prevent this value from being | |
4116 | * inconsistent. | |
4117 | */ | |
4118 | cgroup_lock(); | |
c0ff4b85 | 4119 | memcg->move_charge_at_immigrate = val; |
7dc74be0 DN |
4120 | cgroup_unlock(); |
4121 | ||
4122 | return 0; | |
4123 | } | |
02491447 DN |
4124 | #else |
4125 | static int mem_cgroup_move_charge_write(struct cgroup *cgrp, | |
4126 | struct cftype *cft, u64 val) | |
4127 | { | |
4128 | return -ENOSYS; | |
4129 | } | |
4130 | #endif | |
7dc74be0 | 4131 | |
406eb0c9 | 4132 | #ifdef CONFIG_NUMA |
ab215884 | 4133 | static int memcg_numa_stat_show(struct cgroup *cont, struct cftype *cft, |
fada52ca | 4134 | struct seq_file *m) |
406eb0c9 YH |
4135 | { |
4136 | int nid; | |
4137 | unsigned long total_nr, file_nr, anon_nr, unevictable_nr; | |
4138 | unsigned long node_nr; | |
d79154bb | 4139 | struct mem_cgroup *memcg = mem_cgroup_from_cont(cont); |
406eb0c9 | 4140 | |
d79154bb | 4141 | total_nr = mem_cgroup_nr_lru_pages(memcg, LRU_ALL); |
406eb0c9 | 4142 | seq_printf(m, "total=%lu", total_nr); |
31aaea4a | 4143 | for_each_node_state(nid, N_MEMORY) { |
d79154bb | 4144 | node_nr = mem_cgroup_node_nr_lru_pages(memcg, nid, LRU_ALL); |
406eb0c9 YH |
4145 | seq_printf(m, " N%d=%lu", nid, node_nr); |
4146 | } | |
4147 | seq_putc(m, '\n'); | |
4148 | ||
d79154bb | 4149 | file_nr = mem_cgroup_nr_lru_pages(memcg, LRU_ALL_FILE); |
406eb0c9 | 4150 | seq_printf(m, "file=%lu", file_nr); |
31aaea4a | 4151 | for_each_node_state(nid, N_MEMORY) { |
d79154bb | 4152 | node_nr = mem_cgroup_node_nr_lru_pages(memcg, nid, |
bb2a0de9 | 4153 | LRU_ALL_FILE); |
406eb0c9 YH |
4154 | seq_printf(m, " N%d=%lu", nid, node_nr); |
4155 | } | |
4156 | seq_putc(m, '\n'); | |
4157 | ||
d79154bb | 4158 | anon_nr = mem_cgroup_nr_lru_pages(memcg, LRU_ALL_ANON); |
406eb0c9 | 4159 | seq_printf(m, "anon=%lu", anon_nr); |
31aaea4a | 4160 | for_each_node_state(nid, N_MEMORY) { |
d79154bb | 4161 | node_nr = mem_cgroup_node_nr_lru_pages(memcg, nid, |
bb2a0de9 | 4162 | LRU_ALL_ANON); |
406eb0c9 YH |
4163 | seq_printf(m, " N%d=%lu", nid, node_nr); |
4164 | } | |
4165 | seq_putc(m, '\n'); | |
4166 | ||
d79154bb | 4167 | unevictable_nr = mem_cgroup_nr_lru_pages(memcg, BIT(LRU_UNEVICTABLE)); |
406eb0c9 | 4168 | seq_printf(m, "unevictable=%lu", unevictable_nr); |
31aaea4a | 4169 | for_each_node_state(nid, N_MEMORY) { |
d79154bb | 4170 | node_nr = mem_cgroup_node_nr_lru_pages(memcg, nid, |
bb2a0de9 | 4171 | BIT(LRU_UNEVICTABLE)); |
406eb0c9 YH |
4172 | seq_printf(m, " N%d=%lu", nid, node_nr); |
4173 | } | |
4174 | seq_putc(m, '\n'); | |
4175 | return 0; | |
4176 | } | |
4177 | #endif /* CONFIG_NUMA */ | |
4178 | ||
af7c4b0e JW |
4179 | static const char * const mem_cgroup_lru_names[] = { |
4180 | "inactive_anon", | |
4181 | "active_anon", | |
4182 | "inactive_file", | |
4183 | "active_file", | |
4184 | "unevictable", | |
4185 | }; | |
4186 | ||
4187 | static inline void mem_cgroup_lru_names_not_uptodate(void) | |
4188 | { | |
4189 | BUILD_BUG_ON(ARRAY_SIZE(mem_cgroup_lru_names) != NR_LRU_LISTS); | |
4190 | } | |
4191 | ||
ab215884 | 4192 | static int memcg_stat_show(struct cgroup *cont, struct cftype *cft, |
78ccf5b5 | 4193 | struct seq_file *m) |
d2ceb9b7 | 4194 | { |
d79154bb | 4195 | struct mem_cgroup *memcg = mem_cgroup_from_cont(cont); |
af7c4b0e JW |
4196 | struct mem_cgroup *mi; |
4197 | unsigned int i; | |
406eb0c9 | 4198 | |
af7c4b0e | 4199 | for (i = 0; i < MEM_CGROUP_STAT_NSTATS; i++) { |
bff6bb83 | 4200 | if (i == MEM_CGROUP_STAT_SWAP && !do_swap_account) |
1dd3a273 | 4201 | continue; |
af7c4b0e JW |
4202 | seq_printf(m, "%s %ld\n", mem_cgroup_stat_names[i], |
4203 | mem_cgroup_read_stat(memcg, i) * PAGE_SIZE); | |
1dd3a273 | 4204 | } |
7b854121 | 4205 | |
af7c4b0e JW |
4206 | for (i = 0; i < MEM_CGROUP_EVENTS_NSTATS; i++) |
4207 | seq_printf(m, "%s %lu\n", mem_cgroup_events_names[i], | |
4208 | mem_cgroup_read_events(memcg, i)); | |
4209 | ||
4210 | for (i = 0; i < NR_LRU_LISTS; i++) | |
4211 | seq_printf(m, "%s %lu\n", mem_cgroup_lru_names[i], | |
4212 | mem_cgroup_nr_lru_pages(memcg, BIT(i)) * PAGE_SIZE); | |
4213 | ||
14067bb3 | 4214 | /* Hierarchical information */ |
fee7b548 KH |
4215 | { |
4216 | unsigned long long limit, memsw_limit; | |
d79154bb | 4217 | memcg_get_hierarchical_limit(memcg, &limit, &memsw_limit); |
78ccf5b5 | 4218 | seq_printf(m, "hierarchical_memory_limit %llu\n", limit); |
fee7b548 | 4219 | if (do_swap_account) |
78ccf5b5 JW |
4220 | seq_printf(m, "hierarchical_memsw_limit %llu\n", |
4221 | memsw_limit); | |
fee7b548 | 4222 | } |
7f016ee8 | 4223 | |
af7c4b0e JW |
4224 | for (i = 0; i < MEM_CGROUP_STAT_NSTATS; i++) { |
4225 | long long val = 0; | |
4226 | ||
bff6bb83 | 4227 | if (i == MEM_CGROUP_STAT_SWAP && !do_swap_account) |
1dd3a273 | 4228 | continue; |
af7c4b0e JW |
4229 | for_each_mem_cgroup_tree(mi, memcg) |
4230 | val += mem_cgroup_read_stat(mi, i) * PAGE_SIZE; | |
4231 | seq_printf(m, "total_%s %lld\n", mem_cgroup_stat_names[i], val); | |
4232 | } | |
4233 | ||
4234 | for (i = 0; i < MEM_CGROUP_EVENTS_NSTATS; i++) { | |
4235 | unsigned long long val = 0; | |
4236 | ||
4237 | for_each_mem_cgroup_tree(mi, memcg) | |
4238 | val += mem_cgroup_read_events(mi, i); | |
4239 | seq_printf(m, "total_%s %llu\n", | |
4240 | mem_cgroup_events_names[i], val); | |
4241 | } | |
4242 | ||
4243 | for (i = 0; i < NR_LRU_LISTS; i++) { | |
4244 | unsigned long long val = 0; | |
4245 | ||
4246 | for_each_mem_cgroup_tree(mi, memcg) | |
4247 | val += mem_cgroup_nr_lru_pages(mi, BIT(i)) * PAGE_SIZE; | |
4248 | seq_printf(m, "total_%s %llu\n", mem_cgroup_lru_names[i], val); | |
1dd3a273 | 4249 | } |
14067bb3 | 4250 | |
7f016ee8 | 4251 | #ifdef CONFIG_DEBUG_VM |
7f016ee8 KM |
4252 | { |
4253 | int nid, zid; | |
4254 | struct mem_cgroup_per_zone *mz; | |
89abfab1 | 4255 | struct zone_reclaim_stat *rstat; |
7f016ee8 KM |
4256 | unsigned long recent_rotated[2] = {0, 0}; |
4257 | unsigned long recent_scanned[2] = {0, 0}; | |
4258 | ||
4259 | for_each_online_node(nid) | |
4260 | for (zid = 0; zid < MAX_NR_ZONES; zid++) { | |
d79154bb | 4261 | mz = mem_cgroup_zoneinfo(memcg, nid, zid); |
89abfab1 | 4262 | rstat = &mz->lruvec.reclaim_stat; |
7f016ee8 | 4263 | |
89abfab1 HD |
4264 | recent_rotated[0] += rstat->recent_rotated[0]; |
4265 | recent_rotated[1] += rstat->recent_rotated[1]; | |
4266 | recent_scanned[0] += rstat->recent_scanned[0]; | |
4267 | recent_scanned[1] += rstat->recent_scanned[1]; | |
7f016ee8 | 4268 | } |
78ccf5b5 JW |
4269 | seq_printf(m, "recent_rotated_anon %lu\n", recent_rotated[0]); |
4270 | seq_printf(m, "recent_rotated_file %lu\n", recent_rotated[1]); | |
4271 | seq_printf(m, "recent_scanned_anon %lu\n", recent_scanned[0]); | |
4272 | seq_printf(m, "recent_scanned_file %lu\n", recent_scanned[1]); | |
7f016ee8 KM |
4273 | } |
4274 | #endif | |
4275 | ||
d2ceb9b7 KH |
4276 | return 0; |
4277 | } | |
4278 | ||
a7885eb8 KM |
4279 | static u64 mem_cgroup_swappiness_read(struct cgroup *cgrp, struct cftype *cft) |
4280 | { | |
4281 | struct mem_cgroup *memcg = mem_cgroup_from_cont(cgrp); | |
4282 | ||
1f4c025b | 4283 | return mem_cgroup_swappiness(memcg); |
a7885eb8 KM |
4284 | } |
4285 | ||
4286 | static int mem_cgroup_swappiness_write(struct cgroup *cgrp, struct cftype *cft, | |
4287 | u64 val) | |
4288 | { | |
4289 | struct mem_cgroup *memcg = mem_cgroup_from_cont(cgrp); | |
4290 | struct mem_cgroup *parent; | |
068b38c1 | 4291 | |
a7885eb8 KM |
4292 | if (val > 100) |
4293 | return -EINVAL; | |
4294 | ||
4295 | if (cgrp->parent == NULL) | |
4296 | return -EINVAL; | |
4297 | ||
4298 | parent = mem_cgroup_from_cont(cgrp->parent); | |
068b38c1 LZ |
4299 | |
4300 | cgroup_lock(); | |
4301 | ||
a7885eb8 KM |
4302 | /* If under hierarchy, only empty-root can set this value */ |
4303 | if ((parent->use_hierarchy) || | |
068b38c1 LZ |
4304 | (memcg->use_hierarchy && !list_empty(&cgrp->children))) { |
4305 | cgroup_unlock(); | |
a7885eb8 | 4306 | return -EINVAL; |
068b38c1 | 4307 | } |
a7885eb8 | 4308 | |
a7885eb8 | 4309 | memcg->swappiness = val; |
a7885eb8 | 4310 | |
068b38c1 LZ |
4311 | cgroup_unlock(); |
4312 | ||
a7885eb8 KM |
4313 | return 0; |
4314 | } | |
4315 | ||
2e72b634 KS |
4316 | static void __mem_cgroup_threshold(struct mem_cgroup *memcg, bool swap) |
4317 | { | |
4318 | struct mem_cgroup_threshold_ary *t; | |
4319 | u64 usage; | |
4320 | int i; | |
4321 | ||
4322 | rcu_read_lock(); | |
4323 | if (!swap) | |
2c488db2 | 4324 | t = rcu_dereference(memcg->thresholds.primary); |
2e72b634 | 4325 | else |
2c488db2 | 4326 | t = rcu_dereference(memcg->memsw_thresholds.primary); |
2e72b634 KS |
4327 | |
4328 | if (!t) | |
4329 | goto unlock; | |
4330 | ||
4331 | usage = mem_cgroup_usage(memcg, swap); | |
4332 | ||
4333 | /* | |
748dad36 | 4334 | * current_threshold points to threshold just below or equal to usage. |
2e72b634 KS |
4335 | * If it's not true, a threshold was crossed after last |
4336 | * call of __mem_cgroup_threshold(). | |
4337 | */ | |
5407a562 | 4338 | i = t->current_threshold; |
2e72b634 KS |
4339 | |
4340 | /* | |
4341 | * Iterate backward over array of thresholds starting from | |
4342 | * current_threshold and check if a threshold is crossed. | |
4343 | * If none of thresholds below usage is crossed, we read | |
4344 | * only one element of the array here. | |
4345 | */ | |
4346 | for (; i >= 0 && unlikely(t->entries[i].threshold > usage); i--) | |
4347 | eventfd_signal(t->entries[i].eventfd, 1); | |
4348 | ||
4349 | /* i = current_threshold + 1 */ | |
4350 | i++; | |
4351 | ||
4352 | /* | |
4353 | * Iterate forward over array of thresholds starting from | |
4354 | * current_threshold+1 and check if a threshold is crossed. | |
4355 | * If none of thresholds above usage is crossed, we read | |
4356 | * only one element of the array here. | |
4357 | */ | |
4358 | for (; i < t->size && unlikely(t->entries[i].threshold <= usage); i++) | |
4359 | eventfd_signal(t->entries[i].eventfd, 1); | |
4360 | ||
4361 | /* Update current_threshold */ | |
5407a562 | 4362 | t->current_threshold = i - 1; |
2e72b634 KS |
4363 | unlock: |
4364 | rcu_read_unlock(); | |
4365 | } | |
4366 | ||
4367 | static void mem_cgroup_threshold(struct mem_cgroup *memcg) | |
4368 | { | |
ad4ca5f4 KS |
4369 | while (memcg) { |
4370 | __mem_cgroup_threshold(memcg, false); | |
4371 | if (do_swap_account) | |
4372 | __mem_cgroup_threshold(memcg, true); | |
4373 | ||
4374 | memcg = parent_mem_cgroup(memcg); | |
4375 | } | |
2e72b634 KS |
4376 | } |
4377 | ||
4378 | static int compare_thresholds(const void *a, const void *b) | |
4379 | { | |
4380 | const struct mem_cgroup_threshold *_a = a; | |
4381 | const struct mem_cgroup_threshold *_b = b; | |
4382 | ||
4383 | return _a->threshold - _b->threshold; | |
4384 | } | |
4385 | ||
c0ff4b85 | 4386 | static int mem_cgroup_oom_notify_cb(struct mem_cgroup *memcg) |
9490ff27 KH |
4387 | { |
4388 | struct mem_cgroup_eventfd_list *ev; | |
4389 | ||
c0ff4b85 | 4390 | list_for_each_entry(ev, &memcg->oom_notify, list) |
9490ff27 KH |
4391 | eventfd_signal(ev->eventfd, 1); |
4392 | return 0; | |
4393 | } | |
4394 | ||
c0ff4b85 | 4395 | static void mem_cgroup_oom_notify(struct mem_cgroup *memcg) |
9490ff27 | 4396 | { |
7d74b06f KH |
4397 | struct mem_cgroup *iter; |
4398 | ||
c0ff4b85 | 4399 | for_each_mem_cgroup_tree(iter, memcg) |
7d74b06f | 4400 | mem_cgroup_oom_notify_cb(iter); |
9490ff27 KH |
4401 | } |
4402 | ||
4403 | static int mem_cgroup_usage_register_event(struct cgroup *cgrp, | |
4404 | struct cftype *cft, struct eventfd_ctx *eventfd, const char *args) | |
2e72b634 KS |
4405 | { |
4406 | struct mem_cgroup *memcg = mem_cgroup_from_cont(cgrp); | |
2c488db2 KS |
4407 | struct mem_cgroup_thresholds *thresholds; |
4408 | struct mem_cgroup_threshold_ary *new; | |
86ae53e1 | 4409 | enum res_type type = MEMFILE_TYPE(cft->private); |
2e72b634 | 4410 | u64 threshold, usage; |
2c488db2 | 4411 | int i, size, ret; |
2e72b634 KS |
4412 | |
4413 | ret = res_counter_memparse_write_strategy(args, &threshold); | |
4414 | if (ret) | |
4415 | return ret; | |
4416 | ||
4417 | mutex_lock(&memcg->thresholds_lock); | |
2c488db2 | 4418 | |
2e72b634 | 4419 | if (type == _MEM) |
2c488db2 | 4420 | thresholds = &memcg->thresholds; |
2e72b634 | 4421 | else if (type == _MEMSWAP) |
2c488db2 | 4422 | thresholds = &memcg->memsw_thresholds; |
2e72b634 KS |
4423 | else |
4424 | BUG(); | |
4425 | ||
4426 | usage = mem_cgroup_usage(memcg, type == _MEMSWAP); | |
4427 | ||
4428 | /* Check if a threshold crossed before adding a new one */ | |
2c488db2 | 4429 | if (thresholds->primary) |
2e72b634 KS |
4430 | __mem_cgroup_threshold(memcg, type == _MEMSWAP); |
4431 | ||
2c488db2 | 4432 | size = thresholds->primary ? thresholds->primary->size + 1 : 1; |
2e72b634 KS |
4433 | |
4434 | /* Allocate memory for new array of thresholds */ | |
2c488db2 | 4435 | new = kmalloc(sizeof(*new) + size * sizeof(struct mem_cgroup_threshold), |
2e72b634 | 4436 | GFP_KERNEL); |
2c488db2 | 4437 | if (!new) { |
2e72b634 KS |
4438 | ret = -ENOMEM; |
4439 | goto unlock; | |
4440 | } | |
2c488db2 | 4441 | new->size = size; |
2e72b634 KS |
4442 | |
4443 | /* Copy thresholds (if any) to new array */ | |
2c488db2 KS |
4444 | if (thresholds->primary) { |
4445 | memcpy(new->entries, thresholds->primary->entries, (size - 1) * | |
2e72b634 | 4446 | sizeof(struct mem_cgroup_threshold)); |
2c488db2 KS |
4447 | } |
4448 | ||
2e72b634 | 4449 | /* Add new threshold */ |
2c488db2 KS |
4450 | new->entries[size - 1].eventfd = eventfd; |
4451 | new->entries[size - 1].threshold = threshold; | |
2e72b634 KS |
4452 | |
4453 | /* Sort thresholds. Registering of new threshold isn't time-critical */ | |
2c488db2 | 4454 | sort(new->entries, size, sizeof(struct mem_cgroup_threshold), |
2e72b634 KS |
4455 | compare_thresholds, NULL); |
4456 | ||
4457 | /* Find current threshold */ | |
2c488db2 | 4458 | new->current_threshold = -1; |
2e72b634 | 4459 | for (i = 0; i < size; i++) { |
748dad36 | 4460 | if (new->entries[i].threshold <= usage) { |
2e72b634 | 4461 | /* |
2c488db2 KS |
4462 | * new->current_threshold will not be used until |
4463 | * rcu_assign_pointer(), so it's safe to increment | |
2e72b634 KS |
4464 | * it here. |
4465 | */ | |
2c488db2 | 4466 | ++new->current_threshold; |
748dad36 SZ |
4467 | } else |
4468 | break; | |
2e72b634 KS |
4469 | } |
4470 | ||
2c488db2 KS |
4471 | /* Free old spare buffer and save old primary buffer as spare */ |
4472 | kfree(thresholds->spare); | |
4473 | thresholds->spare = thresholds->primary; | |
4474 | ||
4475 | rcu_assign_pointer(thresholds->primary, new); | |
2e72b634 | 4476 | |
907860ed | 4477 | /* To be sure that nobody uses thresholds */ |
2e72b634 KS |
4478 | synchronize_rcu(); |
4479 | ||
2e72b634 KS |
4480 | unlock: |
4481 | mutex_unlock(&memcg->thresholds_lock); | |
4482 | ||
4483 | return ret; | |
4484 | } | |
4485 | ||
907860ed | 4486 | static void mem_cgroup_usage_unregister_event(struct cgroup *cgrp, |
9490ff27 | 4487 | struct cftype *cft, struct eventfd_ctx *eventfd) |
2e72b634 KS |
4488 | { |
4489 | struct mem_cgroup *memcg = mem_cgroup_from_cont(cgrp); | |
2c488db2 KS |
4490 | struct mem_cgroup_thresholds *thresholds; |
4491 | struct mem_cgroup_threshold_ary *new; | |
86ae53e1 | 4492 | enum res_type type = MEMFILE_TYPE(cft->private); |
2e72b634 | 4493 | u64 usage; |
2c488db2 | 4494 | int i, j, size; |
2e72b634 KS |
4495 | |
4496 | mutex_lock(&memcg->thresholds_lock); | |
4497 | if (type == _MEM) | |
2c488db2 | 4498 | thresholds = &memcg->thresholds; |
2e72b634 | 4499 | else if (type == _MEMSWAP) |
2c488db2 | 4500 | thresholds = &memcg->memsw_thresholds; |
2e72b634 KS |
4501 | else |
4502 | BUG(); | |
4503 | ||
371528ca AV |
4504 | if (!thresholds->primary) |
4505 | goto unlock; | |
4506 | ||
2e72b634 KS |
4507 | usage = mem_cgroup_usage(memcg, type == _MEMSWAP); |
4508 | ||
4509 | /* Check if a threshold crossed before removing */ | |
4510 | __mem_cgroup_threshold(memcg, type == _MEMSWAP); | |
4511 | ||
4512 | /* Calculate new number of threshold */ | |
2c488db2 KS |
4513 | size = 0; |
4514 | for (i = 0; i < thresholds->primary->size; i++) { | |
4515 | if (thresholds->primary->entries[i].eventfd != eventfd) | |
2e72b634 KS |
4516 | size++; |
4517 | } | |
4518 | ||
2c488db2 | 4519 | new = thresholds->spare; |
907860ed | 4520 | |
2e72b634 KS |
4521 | /* Set thresholds array to NULL if we don't have thresholds */ |
4522 | if (!size) { | |
2c488db2 KS |
4523 | kfree(new); |
4524 | new = NULL; | |
907860ed | 4525 | goto swap_buffers; |
2e72b634 KS |
4526 | } |
4527 | ||
2c488db2 | 4528 | new->size = size; |
2e72b634 KS |
4529 | |
4530 | /* Copy thresholds and find current threshold */ | |
2c488db2 KS |
4531 | new->current_threshold = -1; |
4532 | for (i = 0, j = 0; i < thresholds->primary->size; i++) { | |
4533 | if (thresholds->primary->entries[i].eventfd == eventfd) | |
2e72b634 KS |
4534 | continue; |
4535 | ||
2c488db2 | 4536 | new->entries[j] = thresholds->primary->entries[i]; |
748dad36 | 4537 | if (new->entries[j].threshold <= usage) { |
2e72b634 | 4538 | /* |
2c488db2 | 4539 | * new->current_threshold will not be used |
2e72b634 KS |
4540 | * until rcu_assign_pointer(), so it's safe to increment |
4541 | * it here. | |
4542 | */ | |
2c488db2 | 4543 | ++new->current_threshold; |
2e72b634 KS |
4544 | } |
4545 | j++; | |
4546 | } | |
4547 | ||
907860ed | 4548 | swap_buffers: |
2c488db2 KS |
4549 | /* Swap primary and spare array */ |
4550 | thresholds->spare = thresholds->primary; | |
8c757763 SZ |
4551 | /* If all events are unregistered, free the spare array */ |
4552 | if (!new) { | |
4553 | kfree(thresholds->spare); | |
4554 | thresholds->spare = NULL; | |
4555 | } | |
4556 | ||
2c488db2 | 4557 | rcu_assign_pointer(thresholds->primary, new); |
2e72b634 | 4558 | |
907860ed | 4559 | /* To be sure that nobody uses thresholds */ |
2e72b634 | 4560 | synchronize_rcu(); |
371528ca | 4561 | unlock: |
2e72b634 | 4562 | mutex_unlock(&memcg->thresholds_lock); |
2e72b634 | 4563 | } |
c1e862c1 | 4564 | |
9490ff27 KH |
4565 | static int mem_cgroup_oom_register_event(struct cgroup *cgrp, |
4566 | struct cftype *cft, struct eventfd_ctx *eventfd, const char *args) | |
4567 | { | |
4568 | struct mem_cgroup *memcg = mem_cgroup_from_cont(cgrp); | |
4569 | struct mem_cgroup_eventfd_list *event; | |
86ae53e1 | 4570 | enum res_type type = MEMFILE_TYPE(cft->private); |
9490ff27 KH |
4571 | |
4572 | BUG_ON(type != _OOM_TYPE); | |
4573 | event = kmalloc(sizeof(*event), GFP_KERNEL); | |
4574 | if (!event) | |
4575 | return -ENOMEM; | |
4576 | ||
1af8efe9 | 4577 | spin_lock(&memcg_oom_lock); |
9490ff27 KH |
4578 | |
4579 | event->eventfd = eventfd; | |
4580 | list_add(&event->list, &memcg->oom_notify); | |
4581 | ||
4582 | /* already in OOM ? */ | |
79dfdacc | 4583 | if (atomic_read(&memcg->under_oom)) |
9490ff27 | 4584 | eventfd_signal(eventfd, 1); |
1af8efe9 | 4585 | spin_unlock(&memcg_oom_lock); |
9490ff27 KH |
4586 | |
4587 | return 0; | |
4588 | } | |
4589 | ||
907860ed | 4590 | static void mem_cgroup_oom_unregister_event(struct cgroup *cgrp, |
9490ff27 KH |
4591 | struct cftype *cft, struct eventfd_ctx *eventfd) |
4592 | { | |
c0ff4b85 | 4593 | struct mem_cgroup *memcg = mem_cgroup_from_cont(cgrp); |
9490ff27 | 4594 | struct mem_cgroup_eventfd_list *ev, *tmp; |
86ae53e1 | 4595 | enum res_type type = MEMFILE_TYPE(cft->private); |
9490ff27 KH |
4596 | |
4597 | BUG_ON(type != _OOM_TYPE); | |
4598 | ||
1af8efe9 | 4599 | spin_lock(&memcg_oom_lock); |
9490ff27 | 4600 | |
c0ff4b85 | 4601 | list_for_each_entry_safe(ev, tmp, &memcg->oom_notify, list) { |
9490ff27 KH |
4602 | if (ev->eventfd == eventfd) { |
4603 | list_del(&ev->list); | |
4604 | kfree(ev); | |
4605 | } | |
4606 | } | |
4607 | ||
1af8efe9 | 4608 | spin_unlock(&memcg_oom_lock); |
9490ff27 KH |
4609 | } |
4610 | ||
3c11ecf4 KH |
4611 | static int mem_cgroup_oom_control_read(struct cgroup *cgrp, |
4612 | struct cftype *cft, struct cgroup_map_cb *cb) | |
4613 | { | |
c0ff4b85 | 4614 | struct mem_cgroup *memcg = mem_cgroup_from_cont(cgrp); |
3c11ecf4 | 4615 | |
c0ff4b85 | 4616 | cb->fill(cb, "oom_kill_disable", memcg->oom_kill_disable); |
3c11ecf4 | 4617 | |
c0ff4b85 | 4618 | if (atomic_read(&memcg->under_oom)) |
3c11ecf4 KH |
4619 | cb->fill(cb, "under_oom", 1); |
4620 | else | |
4621 | cb->fill(cb, "under_oom", 0); | |
4622 | return 0; | |
4623 | } | |
4624 | ||
3c11ecf4 KH |
4625 | static int mem_cgroup_oom_control_write(struct cgroup *cgrp, |
4626 | struct cftype *cft, u64 val) | |
4627 | { | |
c0ff4b85 | 4628 | struct mem_cgroup *memcg = mem_cgroup_from_cont(cgrp); |
3c11ecf4 KH |
4629 | struct mem_cgroup *parent; |
4630 | ||
4631 | /* cannot set to root cgroup and only 0 and 1 are allowed */ | |
4632 | if (!cgrp->parent || !((val == 0) || (val == 1))) | |
4633 | return -EINVAL; | |
4634 | ||
4635 | parent = mem_cgroup_from_cont(cgrp->parent); | |
4636 | ||
4637 | cgroup_lock(); | |
4638 | /* oom-kill-disable is a flag for subhierarchy. */ | |
4639 | if ((parent->use_hierarchy) || | |
c0ff4b85 | 4640 | (memcg->use_hierarchy && !list_empty(&cgrp->children))) { |
3c11ecf4 KH |
4641 | cgroup_unlock(); |
4642 | return -EINVAL; | |
4643 | } | |
c0ff4b85 | 4644 | memcg->oom_kill_disable = val; |
4d845ebf | 4645 | if (!val) |
c0ff4b85 | 4646 | memcg_oom_recover(memcg); |
3c11ecf4 KH |
4647 | cgroup_unlock(); |
4648 | return 0; | |
4649 | } | |
4650 | ||
c255a458 | 4651 | #ifdef CONFIG_MEMCG_KMEM |
cbe128e3 | 4652 | static int memcg_init_kmem(struct mem_cgroup *memcg, struct cgroup_subsys *ss) |
e5671dfa | 4653 | { |
1d62e436 | 4654 | return mem_cgroup_sockets_init(memcg, ss); |
e5671dfa GC |
4655 | }; |
4656 | ||
1d62e436 | 4657 | static void kmem_cgroup_destroy(struct mem_cgroup *memcg) |
d1a4c0b3 | 4658 | { |
1d62e436 | 4659 | mem_cgroup_sockets_destroy(memcg); |
d1a4c0b3 | 4660 | } |
e5671dfa | 4661 | #else |
cbe128e3 | 4662 | static int memcg_init_kmem(struct mem_cgroup *memcg, struct cgroup_subsys *ss) |
e5671dfa GC |
4663 | { |
4664 | return 0; | |
4665 | } | |
d1a4c0b3 | 4666 | |
1d62e436 | 4667 | static void kmem_cgroup_destroy(struct mem_cgroup *memcg) |
d1a4c0b3 GC |
4668 | { |
4669 | } | |
e5671dfa GC |
4670 | #endif |
4671 | ||
8cdea7c0 BS |
4672 | static struct cftype mem_cgroup_files[] = { |
4673 | { | |
0eea1030 | 4674 | .name = "usage_in_bytes", |
8c7c6e34 | 4675 | .private = MEMFILE_PRIVATE(_MEM, RES_USAGE), |
af36f906 | 4676 | .read = mem_cgroup_read, |
9490ff27 KH |
4677 | .register_event = mem_cgroup_usage_register_event, |
4678 | .unregister_event = mem_cgroup_usage_unregister_event, | |
8cdea7c0 | 4679 | }, |
c84872e1 PE |
4680 | { |
4681 | .name = "max_usage_in_bytes", | |
8c7c6e34 | 4682 | .private = MEMFILE_PRIVATE(_MEM, RES_MAX_USAGE), |
29f2a4da | 4683 | .trigger = mem_cgroup_reset, |
af36f906 | 4684 | .read = mem_cgroup_read, |
c84872e1 | 4685 | }, |
8cdea7c0 | 4686 | { |
0eea1030 | 4687 | .name = "limit_in_bytes", |
8c7c6e34 | 4688 | .private = MEMFILE_PRIVATE(_MEM, RES_LIMIT), |
856c13aa | 4689 | .write_string = mem_cgroup_write, |
af36f906 | 4690 | .read = mem_cgroup_read, |
8cdea7c0 | 4691 | }, |
296c81d8 BS |
4692 | { |
4693 | .name = "soft_limit_in_bytes", | |
4694 | .private = MEMFILE_PRIVATE(_MEM, RES_SOFT_LIMIT), | |
4695 | .write_string = mem_cgroup_write, | |
af36f906 | 4696 | .read = mem_cgroup_read, |
296c81d8 | 4697 | }, |
8cdea7c0 BS |
4698 | { |
4699 | .name = "failcnt", | |
8c7c6e34 | 4700 | .private = MEMFILE_PRIVATE(_MEM, RES_FAILCNT), |
29f2a4da | 4701 | .trigger = mem_cgroup_reset, |
af36f906 | 4702 | .read = mem_cgroup_read, |
8cdea7c0 | 4703 | }, |
d2ceb9b7 KH |
4704 | { |
4705 | .name = "stat", | |
ab215884 | 4706 | .read_seq_string = memcg_stat_show, |
d2ceb9b7 | 4707 | }, |
c1e862c1 KH |
4708 | { |
4709 | .name = "force_empty", | |
4710 | .trigger = mem_cgroup_force_empty_write, | |
4711 | }, | |
18f59ea7 BS |
4712 | { |
4713 | .name = "use_hierarchy", | |
4714 | .write_u64 = mem_cgroup_hierarchy_write, | |
4715 | .read_u64 = mem_cgroup_hierarchy_read, | |
4716 | }, | |
a7885eb8 KM |
4717 | { |
4718 | .name = "swappiness", | |
4719 | .read_u64 = mem_cgroup_swappiness_read, | |
4720 | .write_u64 = mem_cgroup_swappiness_write, | |
4721 | }, | |
7dc74be0 DN |
4722 | { |
4723 | .name = "move_charge_at_immigrate", | |
4724 | .read_u64 = mem_cgroup_move_charge_read, | |
4725 | .write_u64 = mem_cgroup_move_charge_write, | |
4726 | }, | |
9490ff27 KH |
4727 | { |
4728 | .name = "oom_control", | |
3c11ecf4 KH |
4729 | .read_map = mem_cgroup_oom_control_read, |
4730 | .write_u64 = mem_cgroup_oom_control_write, | |
9490ff27 KH |
4731 | .register_event = mem_cgroup_oom_register_event, |
4732 | .unregister_event = mem_cgroup_oom_unregister_event, | |
4733 | .private = MEMFILE_PRIVATE(_OOM_TYPE, OOM_CONTROL), | |
4734 | }, | |
406eb0c9 YH |
4735 | #ifdef CONFIG_NUMA |
4736 | { | |
4737 | .name = "numa_stat", | |
ab215884 | 4738 | .read_seq_string = memcg_numa_stat_show, |
406eb0c9 YH |
4739 | }, |
4740 | #endif | |
c255a458 | 4741 | #ifdef CONFIG_MEMCG_SWAP |
8c7c6e34 KH |
4742 | { |
4743 | .name = "memsw.usage_in_bytes", | |
4744 | .private = MEMFILE_PRIVATE(_MEMSWAP, RES_USAGE), | |
af36f906 | 4745 | .read = mem_cgroup_read, |
9490ff27 KH |
4746 | .register_event = mem_cgroup_usage_register_event, |
4747 | .unregister_event = mem_cgroup_usage_unregister_event, | |
8c7c6e34 KH |
4748 | }, |
4749 | { | |
4750 | .name = "memsw.max_usage_in_bytes", | |
4751 | .private = MEMFILE_PRIVATE(_MEMSWAP, RES_MAX_USAGE), | |
4752 | .trigger = mem_cgroup_reset, | |
af36f906 | 4753 | .read = mem_cgroup_read, |
8c7c6e34 KH |
4754 | }, |
4755 | { | |
4756 | .name = "memsw.limit_in_bytes", | |
4757 | .private = MEMFILE_PRIVATE(_MEMSWAP, RES_LIMIT), | |
4758 | .write_string = mem_cgroup_write, | |
af36f906 | 4759 | .read = mem_cgroup_read, |
8c7c6e34 KH |
4760 | }, |
4761 | { | |
4762 | .name = "memsw.failcnt", | |
4763 | .private = MEMFILE_PRIVATE(_MEMSWAP, RES_FAILCNT), | |
4764 | .trigger = mem_cgroup_reset, | |
af36f906 | 4765 | .read = mem_cgroup_read, |
8c7c6e34 | 4766 | }, |
8c7c6e34 | 4767 | #endif |
6bc10349 | 4768 | { }, /* terminate */ |
af36f906 | 4769 | }; |
8c7c6e34 | 4770 | |
c0ff4b85 | 4771 | static int alloc_mem_cgroup_per_zone_info(struct mem_cgroup *memcg, int node) |
6d12e2d8 KH |
4772 | { |
4773 | struct mem_cgroup_per_node *pn; | |
1ecaab2b | 4774 | struct mem_cgroup_per_zone *mz; |
41e3355d | 4775 | int zone, tmp = node; |
1ecaab2b KH |
4776 | /* |
4777 | * This routine is called against possible nodes. | |
4778 | * But it's BUG to call kmalloc() against offline node. | |
4779 | * | |
4780 | * TODO: this routine can waste much memory for nodes which will | |
4781 | * never be onlined. It's better to use memory hotplug callback | |
4782 | * function. | |
4783 | */ | |
41e3355d KH |
4784 | if (!node_state(node, N_NORMAL_MEMORY)) |
4785 | tmp = -1; | |
17295c88 | 4786 | pn = kzalloc_node(sizeof(*pn), GFP_KERNEL, tmp); |
6d12e2d8 KH |
4787 | if (!pn) |
4788 | return 1; | |
1ecaab2b | 4789 | |
1ecaab2b KH |
4790 | for (zone = 0; zone < MAX_NR_ZONES; zone++) { |
4791 | mz = &pn->zoneinfo[zone]; | |
bea8c150 | 4792 | lruvec_init(&mz->lruvec); |
f64c3f54 | 4793 | mz->usage_in_excess = 0; |
4e416953 | 4794 | mz->on_tree = false; |
d79154bb | 4795 | mz->memcg = memcg; |
1ecaab2b | 4796 | } |
0a619e58 | 4797 | memcg->info.nodeinfo[node] = pn; |
6d12e2d8 KH |
4798 | return 0; |
4799 | } | |
4800 | ||
c0ff4b85 | 4801 | static void free_mem_cgroup_per_zone_info(struct mem_cgroup *memcg, int node) |
1ecaab2b | 4802 | { |
c0ff4b85 | 4803 | kfree(memcg->info.nodeinfo[node]); |
1ecaab2b KH |
4804 | } |
4805 | ||
33327948 KH |
4806 | static struct mem_cgroup *mem_cgroup_alloc(void) |
4807 | { | |
d79154bb | 4808 | struct mem_cgroup *memcg; |
c62b1a3b | 4809 | int size = sizeof(struct mem_cgroup); |
33327948 | 4810 | |
c62b1a3b | 4811 | /* Can be very big if MAX_NUMNODES is very big */ |
c8dad2bb | 4812 | if (size < PAGE_SIZE) |
d79154bb | 4813 | memcg = kzalloc(size, GFP_KERNEL); |
33327948 | 4814 | else |
d79154bb | 4815 | memcg = vzalloc(size); |
33327948 | 4816 | |
d79154bb | 4817 | if (!memcg) |
e7bbcdf3 DC |
4818 | return NULL; |
4819 | ||
d79154bb HD |
4820 | memcg->stat = alloc_percpu(struct mem_cgroup_stat_cpu); |
4821 | if (!memcg->stat) | |
d2e61b8d | 4822 | goto out_free; |
d79154bb HD |
4823 | spin_lock_init(&memcg->pcp_counter_lock); |
4824 | return memcg; | |
d2e61b8d DC |
4825 | |
4826 | out_free: | |
4827 | if (size < PAGE_SIZE) | |
d79154bb | 4828 | kfree(memcg); |
d2e61b8d | 4829 | else |
d79154bb | 4830 | vfree(memcg); |
d2e61b8d | 4831 | return NULL; |
33327948 KH |
4832 | } |
4833 | ||
59927fb9 | 4834 | /* |
3afe36b1 | 4835 | * Helpers for freeing a kmalloc()ed/vzalloc()ed mem_cgroup by RCU, |
59927fb9 HD |
4836 | * but in process context. The work_freeing structure is overlaid |
4837 | * on the rcu_freeing structure, which itself is overlaid on memsw. | |
4838 | */ | |
3afe36b1 | 4839 | static void free_work(struct work_struct *work) |
59927fb9 HD |
4840 | { |
4841 | struct mem_cgroup *memcg; | |
3afe36b1 | 4842 | int size = sizeof(struct mem_cgroup); |
59927fb9 HD |
4843 | |
4844 | memcg = container_of(work, struct mem_cgroup, work_freeing); | |
3f134619 GC |
4845 | /* |
4846 | * We need to make sure that (at least for now), the jump label | |
4847 | * destruction code runs outside of the cgroup lock. This is because | |
4848 | * get_online_cpus(), which is called from the static_branch update, | |
4849 | * can't be called inside the cgroup_lock. cpusets are the ones | |
4850 | * enforcing this dependency, so if they ever change, we might as well. | |
4851 | * | |
4852 | * schedule_work() will guarantee this happens. Be careful if you need | |
4853 | * to move this code around, and make sure it is outside | |
4854 | * the cgroup_lock. | |
4855 | */ | |
4856 | disarm_sock_keys(memcg); | |
3afe36b1 GC |
4857 | if (size < PAGE_SIZE) |
4858 | kfree(memcg); | |
4859 | else | |
4860 | vfree(memcg); | |
59927fb9 | 4861 | } |
3afe36b1 GC |
4862 | |
4863 | static void free_rcu(struct rcu_head *rcu_head) | |
59927fb9 HD |
4864 | { |
4865 | struct mem_cgroup *memcg; | |
4866 | ||
4867 | memcg = container_of(rcu_head, struct mem_cgroup, rcu_freeing); | |
3afe36b1 | 4868 | INIT_WORK(&memcg->work_freeing, free_work); |
59927fb9 HD |
4869 | schedule_work(&memcg->work_freeing); |
4870 | } | |
4871 | ||
8c7c6e34 KH |
4872 | /* |
4873 | * At destroying mem_cgroup, references from swap_cgroup can remain. | |
4874 | * (scanning all at force_empty is too costly...) | |
4875 | * | |
4876 | * Instead of clearing all references at force_empty, we remember | |
4877 | * the number of reference from swap_cgroup and free mem_cgroup when | |
4878 | * it goes down to 0. | |
4879 | * | |
8c7c6e34 KH |
4880 | * Removal of cgroup itself succeeds regardless of refs from swap. |
4881 | */ | |
4882 | ||
c0ff4b85 | 4883 | static void __mem_cgroup_free(struct mem_cgroup *memcg) |
33327948 | 4884 | { |
08e552c6 KH |
4885 | int node; |
4886 | ||
c0ff4b85 R |
4887 | mem_cgroup_remove_from_trees(memcg); |
4888 | free_css_id(&mem_cgroup_subsys, &memcg->css); | |
04046e1a | 4889 | |
3ed28fa1 | 4890 | for_each_node(node) |
c0ff4b85 | 4891 | free_mem_cgroup_per_zone_info(memcg, node); |
08e552c6 | 4892 | |
c0ff4b85 | 4893 | free_percpu(memcg->stat); |
3afe36b1 | 4894 | call_rcu(&memcg->rcu_freeing, free_rcu); |
33327948 KH |
4895 | } |
4896 | ||
c0ff4b85 | 4897 | static void mem_cgroup_get(struct mem_cgroup *memcg) |
8c7c6e34 | 4898 | { |
c0ff4b85 | 4899 | atomic_inc(&memcg->refcnt); |
8c7c6e34 KH |
4900 | } |
4901 | ||
c0ff4b85 | 4902 | static void __mem_cgroup_put(struct mem_cgroup *memcg, int count) |
8c7c6e34 | 4903 | { |
c0ff4b85 R |
4904 | if (atomic_sub_and_test(count, &memcg->refcnt)) { |
4905 | struct mem_cgroup *parent = parent_mem_cgroup(memcg); | |
4906 | __mem_cgroup_free(memcg); | |
7bcc1bb1 DN |
4907 | if (parent) |
4908 | mem_cgroup_put(parent); | |
4909 | } | |
8c7c6e34 KH |
4910 | } |
4911 | ||
c0ff4b85 | 4912 | static void mem_cgroup_put(struct mem_cgroup *memcg) |
483c30b5 | 4913 | { |
c0ff4b85 | 4914 | __mem_cgroup_put(memcg, 1); |
483c30b5 DN |
4915 | } |
4916 | ||
7bcc1bb1 DN |
4917 | /* |
4918 | * Returns the parent mem_cgroup in memcgroup hierarchy with hierarchy enabled. | |
4919 | */ | |
e1aab161 | 4920 | struct mem_cgroup *parent_mem_cgroup(struct mem_cgroup *memcg) |
7bcc1bb1 | 4921 | { |
c0ff4b85 | 4922 | if (!memcg->res.parent) |
7bcc1bb1 | 4923 | return NULL; |
c0ff4b85 | 4924 | return mem_cgroup_from_res_counter(memcg->res.parent, res); |
7bcc1bb1 | 4925 | } |
e1aab161 | 4926 | EXPORT_SYMBOL(parent_mem_cgroup); |
33327948 | 4927 | |
c255a458 | 4928 | #ifdef CONFIG_MEMCG_SWAP |
c077719b KH |
4929 | static void __init enable_swap_cgroup(void) |
4930 | { | |
f8d66542 | 4931 | if (!mem_cgroup_disabled() && really_do_swap_account) |
c077719b KH |
4932 | do_swap_account = 1; |
4933 | } | |
4934 | #else | |
4935 | static void __init enable_swap_cgroup(void) | |
4936 | { | |
4937 | } | |
4938 | #endif | |
4939 | ||
f64c3f54 BS |
4940 | static int mem_cgroup_soft_limit_tree_init(void) |
4941 | { | |
4942 | struct mem_cgroup_tree_per_node *rtpn; | |
4943 | struct mem_cgroup_tree_per_zone *rtpz; | |
4944 | int tmp, node, zone; | |
4945 | ||
3ed28fa1 | 4946 | for_each_node(node) { |
f64c3f54 BS |
4947 | tmp = node; |
4948 | if (!node_state(node, N_NORMAL_MEMORY)) | |
4949 | tmp = -1; | |
4950 | rtpn = kzalloc_node(sizeof(*rtpn), GFP_KERNEL, tmp); | |
4951 | if (!rtpn) | |
c3cecc68 | 4952 | goto err_cleanup; |
f64c3f54 BS |
4953 | |
4954 | soft_limit_tree.rb_tree_per_node[node] = rtpn; | |
4955 | ||
4956 | for (zone = 0; zone < MAX_NR_ZONES; zone++) { | |
4957 | rtpz = &rtpn->rb_tree_per_zone[zone]; | |
4958 | rtpz->rb_root = RB_ROOT; | |
4959 | spin_lock_init(&rtpz->lock); | |
4960 | } | |
4961 | } | |
4962 | return 0; | |
c3cecc68 MH |
4963 | |
4964 | err_cleanup: | |
3ed28fa1 | 4965 | for_each_node(node) { |
c3cecc68 MH |
4966 | if (!soft_limit_tree.rb_tree_per_node[node]) |
4967 | break; | |
4968 | kfree(soft_limit_tree.rb_tree_per_node[node]); | |
4969 | soft_limit_tree.rb_tree_per_node[node] = NULL; | |
4970 | } | |
4971 | return 1; | |
4972 | ||
f64c3f54 BS |
4973 | } |
4974 | ||
0eb253e2 | 4975 | static struct cgroup_subsys_state * __ref |
92fb9748 | 4976 | mem_cgroup_css_alloc(struct cgroup *cont) |
8cdea7c0 | 4977 | { |
c0ff4b85 | 4978 | struct mem_cgroup *memcg, *parent; |
04046e1a | 4979 | long error = -ENOMEM; |
6d12e2d8 | 4980 | int node; |
8cdea7c0 | 4981 | |
c0ff4b85 R |
4982 | memcg = mem_cgroup_alloc(); |
4983 | if (!memcg) | |
04046e1a | 4984 | return ERR_PTR(error); |
78fb7466 | 4985 | |
3ed28fa1 | 4986 | for_each_node(node) |
c0ff4b85 | 4987 | if (alloc_mem_cgroup_per_zone_info(memcg, node)) |
6d12e2d8 | 4988 | goto free_out; |
f64c3f54 | 4989 | |
c077719b | 4990 | /* root ? */ |
28dbc4b6 | 4991 | if (cont->parent == NULL) { |
cdec2e42 | 4992 | int cpu; |
c077719b | 4993 | enable_swap_cgroup(); |
28dbc4b6 | 4994 | parent = NULL; |
f64c3f54 BS |
4995 | if (mem_cgroup_soft_limit_tree_init()) |
4996 | goto free_out; | |
a41c58a6 | 4997 | root_mem_cgroup = memcg; |
cdec2e42 KH |
4998 | for_each_possible_cpu(cpu) { |
4999 | struct memcg_stock_pcp *stock = | |
5000 | &per_cpu(memcg_stock, cpu); | |
5001 | INIT_WORK(&stock->work, drain_local_stock); | |
5002 | } | |
711d3d2c | 5003 | hotcpu_notifier(memcg_cpu_hotplug_callback, 0); |
18f59ea7 | 5004 | } else { |
28dbc4b6 | 5005 | parent = mem_cgroup_from_cont(cont->parent); |
c0ff4b85 R |
5006 | memcg->use_hierarchy = parent->use_hierarchy; |
5007 | memcg->oom_kill_disable = parent->oom_kill_disable; | |
18f59ea7 | 5008 | } |
28dbc4b6 | 5009 | |
18f59ea7 | 5010 | if (parent && parent->use_hierarchy) { |
c0ff4b85 R |
5011 | res_counter_init(&memcg->res, &parent->res); |
5012 | res_counter_init(&memcg->memsw, &parent->memsw); | |
7bcc1bb1 DN |
5013 | /* |
5014 | * We increment refcnt of the parent to ensure that we can | |
5015 | * safely access it on res_counter_charge/uncharge. | |
5016 | * This refcnt will be decremented when freeing this | |
5017 | * mem_cgroup(see mem_cgroup_put). | |
5018 | */ | |
5019 | mem_cgroup_get(parent); | |
18f59ea7 | 5020 | } else { |
c0ff4b85 R |
5021 | res_counter_init(&memcg->res, NULL); |
5022 | res_counter_init(&memcg->memsw, NULL); | |
8c7f6edb TH |
5023 | /* |
5024 | * Deeper hierachy with use_hierarchy == false doesn't make | |
5025 | * much sense so let cgroup subsystem know about this | |
5026 | * unfortunate state in our controller. | |
5027 | */ | |
5028 | if (parent && parent != root_mem_cgroup) | |
5029 | mem_cgroup_subsys.broken_hierarchy = true; | |
18f59ea7 | 5030 | } |
c0ff4b85 R |
5031 | memcg->last_scanned_node = MAX_NUMNODES; |
5032 | INIT_LIST_HEAD(&memcg->oom_notify); | |
6d61ef40 | 5033 | |
a7885eb8 | 5034 | if (parent) |
c0ff4b85 R |
5035 | memcg->swappiness = mem_cgroup_swappiness(parent); |
5036 | atomic_set(&memcg->refcnt, 1); | |
5037 | memcg->move_charge_at_immigrate = 0; | |
5038 | mutex_init(&memcg->thresholds_lock); | |
312734c0 | 5039 | spin_lock_init(&memcg->move_lock); |
cbe128e3 GC |
5040 | |
5041 | error = memcg_init_kmem(memcg, &mem_cgroup_subsys); | |
5042 | if (error) { | |
5043 | /* | |
5044 | * We call put now because our (and parent's) refcnts | |
5045 | * are already in place. mem_cgroup_put() will internally | |
5046 | * call __mem_cgroup_free, so return directly | |
5047 | */ | |
5048 | mem_cgroup_put(memcg); | |
5049 | return ERR_PTR(error); | |
5050 | } | |
c0ff4b85 | 5051 | return &memcg->css; |
6d12e2d8 | 5052 | free_out: |
c0ff4b85 | 5053 | __mem_cgroup_free(memcg); |
04046e1a | 5054 | return ERR_PTR(error); |
8cdea7c0 BS |
5055 | } |
5056 | ||
92fb9748 | 5057 | static void mem_cgroup_css_offline(struct cgroup *cont) |
df878fb0 | 5058 | { |
c0ff4b85 | 5059 | struct mem_cgroup *memcg = mem_cgroup_from_cont(cont); |
ec64f515 | 5060 | |
ab5196c2 | 5061 | mem_cgroup_reparent_charges(memcg); |
df878fb0 KH |
5062 | } |
5063 | ||
92fb9748 | 5064 | static void mem_cgroup_css_free(struct cgroup *cont) |
8cdea7c0 | 5065 | { |
c0ff4b85 | 5066 | struct mem_cgroup *memcg = mem_cgroup_from_cont(cont); |
c268e994 | 5067 | |
1d62e436 | 5068 | kmem_cgroup_destroy(memcg); |
d1a4c0b3 | 5069 | |
c0ff4b85 | 5070 | mem_cgroup_put(memcg); |
8cdea7c0 BS |
5071 | } |
5072 | ||
02491447 | 5073 | #ifdef CONFIG_MMU |
7dc74be0 | 5074 | /* Handlers for move charge at task migration. */ |
854ffa8d DN |
5075 | #define PRECHARGE_COUNT_AT_ONCE 256 |
5076 | static int mem_cgroup_do_precharge(unsigned long count) | |
7dc74be0 | 5077 | { |
854ffa8d DN |
5078 | int ret = 0; |
5079 | int batch_count = PRECHARGE_COUNT_AT_ONCE; | |
c0ff4b85 | 5080 | struct mem_cgroup *memcg = mc.to; |
4ffef5fe | 5081 | |
c0ff4b85 | 5082 | if (mem_cgroup_is_root(memcg)) { |
854ffa8d DN |
5083 | mc.precharge += count; |
5084 | /* we don't need css_get for root */ | |
5085 | return ret; | |
5086 | } | |
5087 | /* try to charge at once */ | |
5088 | if (count > 1) { | |
5089 | struct res_counter *dummy; | |
5090 | /* | |
c0ff4b85 | 5091 | * "memcg" cannot be under rmdir() because we've already checked |
854ffa8d DN |
5092 | * by cgroup_lock_live_cgroup() that it is not removed and we |
5093 | * are still under the same cgroup_mutex. So we can postpone | |
5094 | * css_get(). | |
5095 | */ | |
c0ff4b85 | 5096 | if (res_counter_charge(&memcg->res, PAGE_SIZE * count, &dummy)) |
854ffa8d | 5097 | goto one_by_one; |
c0ff4b85 | 5098 | if (do_swap_account && res_counter_charge(&memcg->memsw, |
854ffa8d | 5099 | PAGE_SIZE * count, &dummy)) { |
c0ff4b85 | 5100 | res_counter_uncharge(&memcg->res, PAGE_SIZE * count); |
854ffa8d DN |
5101 | goto one_by_one; |
5102 | } | |
5103 | mc.precharge += count; | |
854ffa8d DN |
5104 | return ret; |
5105 | } | |
5106 | one_by_one: | |
5107 | /* fall back to one by one charge */ | |
5108 | while (count--) { | |
5109 | if (signal_pending(current)) { | |
5110 | ret = -EINTR; | |
5111 | break; | |
5112 | } | |
5113 | if (!batch_count--) { | |
5114 | batch_count = PRECHARGE_COUNT_AT_ONCE; | |
5115 | cond_resched(); | |
5116 | } | |
c0ff4b85 R |
5117 | ret = __mem_cgroup_try_charge(NULL, |
5118 | GFP_KERNEL, 1, &memcg, false); | |
38c5d72f | 5119 | if (ret) |
854ffa8d | 5120 | /* mem_cgroup_clear_mc() will do uncharge later */ |
38c5d72f | 5121 | return ret; |
854ffa8d DN |
5122 | mc.precharge++; |
5123 | } | |
4ffef5fe DN |
5124 | return ret; |
5125 | } | |
5126 | ||
5127 | /** | |
8d32ff84 | 5128 | * get_mctgt_type - get target type of moving charge |
4ffef5fe DN |
5129 | * @vma: the vma the pte to be checked belongs |
5130 | * @addr: the address corresponding to the pte to be checked | |
5131 | * @ptent: the pte to be checked | |
02491447 | 5132 | * @target: the pointer the target page or swap ent will be stored(can be NULL) |
4ffef5fe DN |
5133 | * |
5134 | * Returns | |
5135 | * 0(MC_TARGET_NONE): if the pte is not a target for move charge. | |
5136 | * 1(MC_TARGET_PAGE): if the page corresponding to this pte is a target for | |
5137 | * move charge. if @target is not NULL, the page is stored in target->page | |
5138 | * with extra refcnt got(Callers should handle it). | |
02491447 DN |
5139 | * 2(MC_TARGET_SWAP): if the swap entry corresponding to this pte is a |
5140 | * target for charge migration. if @target is not NULL, the entry is stored | |
5141 | * in target->ent. | |
4ffef5fe DN |
5142 | * |
5143 | * Called with pte lock held. | |
5144 | */ | |
4ffef5fe DN |
5145 | union mc_target { |
5146 | struct page *page; | |
02491447 | 5147 | swp_entry_t ent; |
4ffef5fe DN |
5148 | }; |
5149 | ||
4ffef5fe | 5150 | enum mc_target_type { |
8d32ff84 | 5151 | MC_TARGET_NONE = 0, |
4ffef5fe | 5152 | MC_TARGET_PAGE, |
02491447 | 5153 | MC_TARGET_SWAP, |
4ffef5fe DN |
5154 | }; |
5155 | ||
90254a65 DN |
5156 | static struct page *mc_handle_present_pte(struct vm_area_struct *vma, |
5157 | unsigned long addr, pte_t ptent) | |
4ffef5fe | 5158 | { |
90254a65 | 5159 | struct page *page = vm_normal_page(vma, addr, ptent); |
4ffef5fe | 5160 | |
90254a65 DN |
5161 | if (!page || !page_mapped(page)) |
5162 | return NULL; | |
5163 | if (PageAnon(page)) { | |
5164 | /* we don't move shared anon */ | |
4b91355e | 5165 | if (!move_anon()) |
90254a65 | 5166 | return NULL; |
87946a72 DN |
5167 | } else if (!move_file()) |
5168 | /* we ignore mapcount for file pages */ | |
90254a65 DN |
5169 | return NULL; |
5170 | if (!get_page_unless_zero(page)) | |
5171 | return NULL; | |
5172 | ||
5173 | return page; | |
5174 | } | |
5175 | ||
4b91355e | 5176 | #ifdef CONFIG_SWAP |
90254a65 DN |
5177 | static struct page *mc_handle_swap_pte(struct vm_area_struct *vma, |
5178 | unsigned long addr, pte_t ptent, swp_entry_t *entry) | |
5179 | { | |
90254a65 DN |
5180 | struct page *page = NULL; |
5181 | swp_entry_t ent = pte_to_swp_entry(ptent); | |
5182 | ||
5183 | if (!move_anon() || non_swap_entry(ent)) | |
5184 | return NULL; | |
4b91355e KH |
5185 | /* |
5186 | * Because lookup_swap_cache() updates some statistics counter, | |
5187 | * we call find_get_page() with swapper_space directly. | |
5188 | */ | |
5189 | page = find_get_page(&swapper_space, ent.val); | |
90254a65 DN |
5190 | if (do_swap_account) |
5191 | entry->val = ent.val; | |
5192 | ||
5193 | return page; | |
5194 | } | |
4b91355e KH |
5195 | #else |
5196 | static struct page *mc_handle_swap_pte(struct vm_area_struct *vma, | |
5197 | unsigned long addr, pte_t ptent, swp_entry_t *entry) | |
5198 | { | |
5199 | return NULL; | |
5200 | } | |
5201 | #endif | |
90254a65 | 5202 | |
87946a72 DN |
5203 | static struct page *mc_handle_file_pte(struct vm_area_struct *vma, |
5204 | unsigned long addr, pte_t ptent, swp_entry_t *entry) | |
5205 | { | |
5206 | struct page *page = NULL; | |
87946a72 DN |
5207 | struct address_space *mapping; |
5208 | pgoff_t pgoff; | |
5209 | ||
5210 | if (!vma->vm_file) /* anonymous vma */ | |
5211 | return NULL; | |
5212 | if (!move_file()) | |
5213 | return NULL; | |
5214 | ||
87946a72 DN |
5215 | mapping = vma->vm_file->f_mapping; |
5216 | if (pte_none(ptent)) | |
5217 | pgoff = linear_page_index(vma, addr); | |
5218 | else /* pte_file(ptent) is true */ | |
5219 | pgoff = pte_to_pgoff(ptent); | |
5220 | ||
5221 | /* page is moved even if it's not RSS of this task(page-faulted). */ | |
aa3b1895 HD |
5222 | page = find_get_page(mapping, pgoff); |
5223 | ||
5224 | #ifdef CONFIG_SWAP | |
5225 | /* shmem/tmpfs may report page out on swap: account for that too. */ | |
5226 | if (radix_tree_exceptional_entry(page)) { | |
5227 | swp_entry_t swap = radix_to_swp_entry(page); | |
87946a72 | 5228 | if (do_swap_account) |
aa3b1895 HD |
5229 | *entry = swap; |
5230 | page = find_get_page(&swapper_space, swap.val); | |
87946a72 | 5231 | } |
aa3b1895 | 5232 | #endif |
87946a72 DN |
5233 | return page; |
5234 | } | |
5235 | ||
8d32ff84 | 5236 | static enum mc_target_type get_mctgt_type(struct vm_area_struct *vma, |
90254a65 DN |
5237 | unsigned long addr, pte_t ptent, union mc_target *target) |
5238 | { | |
5239 | struct page *page = NULL; | |
5240 | struct page_cgroup *pc; | |
8d32ff84 | 5241 | enum mc_target_type ret = MC_TARGET_NONE; |
90254a65 DN |
5242 | swp_entry_t ent = { .val = 0 }; |
5243 | ||
5244 | if (pte_present(ptent)) | |
5245 | page = mc_handle_present_pte(vma, addr, ptent); | |
5246 | else if (is_swap_pte(ptent)) | |
5247 | page = mc_handle_swap_pte(vma, addr, ptent, &ent); | |
87946a72 DN |
5248 | else if (pte_none(ptent) || pte_file(ptent)) |
5249 | page = mc_handle_file_pte(vma, addr, ptent, &ent); | |
90254a65 DN |
5250 | |
5251 | if (!page && !ent.val) | |
8d32ff84 | 5252 | return ret; |
02491447 DN |
5253 | if (page) { |
5254 | pc = lookup_page_cgroup(page); | |
5255 | /* | |
5256 | * Do only loose check w/o page_cgroup lock. | |
5257 | * mem_cgroup_move_account() checks the pc is valid or not under | |
5258 | * the lock. | |
5259 | */ | |
5260 | if (PageCgroupUsed(pc) && pc->mem_cgroup == mc.from) { | |
5261 | ret = MC_TARGET_PAGE; | |
5262 | if (target) | |
5263 | target->page = page; | |
5264 | } | |
5265 | if (!ret || !target) | |
5266 | put_page(page); | |
5267 | } | |
90254a65 DN |
5268 | /* There is a swap entry and a page doesn't exist or isn't charged */ |
5269 | if (ent.val && !ret && | |
9fb4b7cc | 5270 | css_id(&mc.from->css) == lookup_swap_cgroup_id(ent)) { |
7f0f1546 KH |
5271 | ret = MC_TARGET_SWAP; |
5272 | if (target) | |
5273 | target->ent = ent; | |
4ffef5fe | 5274 | } |
4ffef5fe DN |
5275 | return ret; |
5276 | } | |
5277 | ||
12724850 NH |
5278 | #ifdef CONFIG_TRANSPARENT_HUGEPAGE |
5279 | /* | |
5280 | * We don't consider swapping or file mapped pages because THP does not | |
5281 | * support them for now. | |
5282 | * Caller should make sure that pmd_trans_huge(pmd) is true. | |
5283 | */ | |
5284 | static enum mc_target_type get_mctgt_type_thp(struct vm_area_struct *vma, | |
5285 | unsigned long addr, pmd_t pmd, union mc_target *target) | |
5286 | { | |
5287 | struct page *page = NULL; | |
5288 | struct page_cgroup *pc; | |
5289 | enum mc_target_type ret = MC_TARGET_NONE; | |
5290 | ||
5291 | page = pmd_page(pmd); | |
5292 | VM_BUG_ON(!page || !PageHead(page)); | |
5293 | if (!move_anon()) | |
5294 | return ret; | |
5295 | pc = lookup_page_cgroup(page); | |
5296 | if (PageCgroupUsed(pc) && pc->mem_cgroup == mc.from) { | |
5297 | ret = MC_TARGET_PAGE; | |
5298 | if (target) { | |
5299 | get_page(page); | |
5300 | target->page = page; | |
5301 | } | |
5302 | } | |
5303 | return ret; | |
5304 | } | |
5305 | #else | |
5306 | static inline enum mc_target_type get_mctgt_type_thp(struct vm_area_struct *vma, | |
5307 | unsigned long addr, pmd_t pmd, union mc_target *target) | |
5308 | { | |
5309 | return MC_TARGET_NONE; | |
5310 | } | |
5311 | #endif | |
5312 | ||
4ffef5fe DN |
5313 | static int mem_cgroup_count_precharge_pte_range(pmd_t *pmd, |
5314 | unsigned long addr, unsigned long end, | |
5315 | struct mm_walk *walk) | |
5316 | { | |
5317 | struct vm_area_struct *vma = walk->private; | |
5318 | pte_t *pte; | |
5319 | spinlock_t *ptl; | |
5320 | ||
12724850 NH |
5321 | if (pmd_trans_huge_lock(pmd, vma) == 1) { |
5322 | if (get_mctgt_type_thp(vma, addr, *pmd, NULL) == MC_TARGET_PAGE) | |
5323 | mc.precharge += HPAGE_PMD_NR; | |
5324 | spin_unlock(&vma->vm_mm->page_table_lock); | |
1a5a9906 | 5325 | return 0; |
12724850 | 5326 | } |
03319327 | 5327 | |
45f83cef AA |
5328 | if (pmd_trans_unstable(pmd)) |
5329 | return 0; | |
4ffef5fe DN |
5330 | pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl); |
5331 | for (; addr != end; pte++, addr += PAGE_SIZE) | |
8d32ff84 | 5332 | if (get_mctgt_type(vma, addr, *pte, NULL)) |
4ffef5fe DN |
5333 | mc.precharge++; /* increment precharge temporarily */ |
5334 | pte_unmap_unlock(pte - 1, ptl); | |
5335 | cond_resched(); | |
5336 | ||
7dc74be0 DN |
5337 | return 0; |
5338 | } | |
5339 | ||
4ffef5fe DN |
5340 | static unsigned long mem_cgroup_count_precharge(struct mm_struct *mm) |
5341 | { | |
5342 | unsigned long precharge; | |
5343 | struct vm_area_struct *vma; | |
5344 | ||
dfe076b0 | 5345 | down_read(&mm->mmap_sem); |
4ffef5fe DN |
5346 | for (vma = mm->mmap; vma; vma = vma->vm_next) { |
5347 | struct mm_walk mem_cgroup_count_precharge_walk = { | |
5348 | .pmd_entry = mem_cgroup_count_precharge_pte_range, | |
5349 | .mm = mm, | |
5350 | .private = vma, | |
5351 | }; | |
5352 | if (is_vm_hugetlb_page(vma)) | |
5353 | continue; | |
4ffef5fe DN |
5354 | walk_page_range(vma->vm_start, vma->vm_end, |
5355 | &mem_cgroup_count_precharge_walk); | |
5356 | } | |
dfe076b0 | 5357 | up_read(&mm->mmap_sem); |
4ffef5fe DN |
5358 | |
5359 | precharge = mc.precharge; | |
5360 | mc.precharge = 0; | |
5361 | ||
5362 | return precharge; | |
5363 | } | |
5364 | ||
4ffef5fe DN |
5365 | static int mem_cgroup_precharge_mc(struct mm_struct *mm) |
5366 | { | |
dfe076b0 DN |
5367 | unsigned long precharge = mem_cgroup_count_precharge(mm); |
5368 | ||
5369 | VM_BUG_ON(mc.moving_task); | |
5370 | mc.moving_task = current; | |
5371 | return mem_cgroup_do_precharge(precharge); | |
4ffef5fe DN |
5372 | } |
5373 | ||
dfe076b0 DN |
5374 | /* cancels all extra charges on mc.from and mc.to, and wakes up all waiters. */ |
5375 | static void __mem_cgroup_clear_mc(void) | |
4ffef5fe | 5376 | { |
2bd9bb20 KH |
5377 | struct mem_cgroup *from = mc.from; |
5378 | struct mem_cgroup *to = mc.to; | |
5379 | ||
4ffef5fe | 5380 | /* we must uncharge all the leftover precharges from mc.to */ |
854ffa8d DN |
5381 | if (mc.precharge) { |
5382 | __mem_cgroup_cancel_charge(mc.to, mc.precharge); | |
5383 | mc.precharge = 0; | |
5384 | } | |
5385 | /* | |
5386 | * we didn't uncharge from mc.from at mem_cgroup_move_account(), so | |
5387 | * we must uncharge here. | |
5388 | */ | |
5389 | if (mc.moved_charge) { | |
5390 | __mem_cgroup_cancel_charge(mc.from, mc.moved_charge); | |
5391 | mc.moved_charge = 0; | |
4ffef5fe | 5392 | } |
483c30b5 DN |
5393 | /* we must fixup refcnts and charges */ |
5394 | if (mc.moved_swap) { | |
483c30b5 DN |
5395 | /* uncharge swap account from the old cgroup */ |
5396 | if (!mem_cgroup_is_root(mc.from)) | |
5397 | res_counter_uncharge(&mc.from->memsw, | |
5398 | PAGE_SIZE * mc.moved_swap); | |
5399 | __mem_cgroup_put(mc.from, mc.moved_swap); | |
5400 | ||
5401 | if (!mem_cgroup_is_root(mc.to)) { | |
5402 | /* | |
5403 | * we charged both to->res and to->memsw, so we should | |
5404 | * uncharge to->res. | |
5405 | */ | |
5406 | res_counter_uncharge(&mc.to->res, | |
5407 | PAGE_SIZE * mc.moved_swap); | |
483c30b5 DN |
5408 | } |
5409 | /* we've already done mem_cgroup_get(mc.to) */ | |
483c30b5 DN |
5410 | mc.moved_swap = 0; |
5411 | } | |
dfe076b0 DN |
5412 | memcg_oom_recover(from); |
5413 | memcg_oom_recover(to); | |
5414 | wake_up_all(&mc.waitq); | |
5415 | } | |
5416 | ||
5417 | static void mem_cgroup_clear_mc(void) | |
5418 | { | |
5419 | struct mem_cgroup *from = mc.from; | |
5420 | ||
5421 | /* | |
5422 | * we must clear moving_task before waking up waiters at the end of | |
5423 | * task migration. | |
5424 | */ | |
5425 | mc.moving_task = NULL; | |
5426 | __mem_cgroup_clear_mc(); | |
2bd9bb20 | 5427 | spin_lock(&mc.lock); |
4ffef5fe DN |
5428 | mc.from = NULL; |
5429 | mc.to = NULL; | |
2bd9bb20 | 5430 | spin_unlock(&mc.lock); |
32047e2a | 5431 | mem_cgroup_end_move(from); |
4ffef5fe DN |
5432 | } |
5433 | ||
761b3ef5 LZ |
5434 | static int mem_cgroup_can_attach(struct cgroup *cgroup, |
5435 | struct cgroup_taskset *tset) | |
7dc74be0 | 5436 | { |
2f7ee569 | 5437 | struct task_struct *p = cgroup_taskset_first(tset); |
7dc74be0 | 5438 | int ret = 0; |
c0ff4b85 | 5439 | struct mem_cgroup *memcg = mem_cgroup_from_cont(cgroup); |
7dc74be0 | 5440 | |
c0ff4b85 | 5441 | if (memcg->move_charge_at_immigrate) { |
7dc74be0 DN |
5442 | struct mm_struct *mm; |
5443 | struct mem_cgroup *from = mem_cgroup_from_task(p); | |
5444 | ||
c0ff4b85 | 5445 | VM_BUG_ON(from == memcg); |
7dc74be0 DN |
5446 | |
5447 | mm = get_task_mm(p); | |
5448 | if (!mm) | |
5449 | return 0; | |
7dc74be0 | 5450 | /* We move charges only when we move a owner of the mm */ |
4ffef5fe DN |
5451 | if (mm->owner == p) { |
5452 | VM_BUG_ON(mc.from); | |
5453 | VM_BUG_ON(mc.to); | |
5454 | VM_BUG_ON(mc.precharge); | |
854ffa8d | 5455 | VM_BUG_ON(mc.moved_charge); |
483c30b5 | 5456 | VM_BUG_ON(mc.moved_swap); |
32047e2a | 5457 | mem_cgroup_start_move(from); |
2bd9bb20 | 5458 | spin_lock(&mc.lock); |
4ffef5fe | 5459 | mc.from = from; |
c0ff4b85 | 5460 | mc.to = memcg; |
2bd9bb20 | 5461 | spin_unlock(&mc.lock); |
dfe076b0 | 5462 | /* We set mc.moving_task later */ |
4ffef5fe DN |
5463 | |
5464 | ret = mem_cgroup_precharge_mc(mm); | |
5465 | if (ret) | |
5466 | mem_cgroup_clear_mc(); | |
dfe076b0 DN |
5467 | } |
5468 | mmput(mm); | |
7dc74be0 DN |
5469 | } |
5470 | return ret; | |
5471 | } | |
5472 | ||
761b3ef5 LZ |
5473 | static void mem_cgroup_cancel_attach(struct cgroup *cgroup, |
5474 | struct cgroup_taskset *tset) | |
7dc74be0 | 5475 | { |
4ffef5fe | 5476 | mem_cgroup_clear_mc(); |
7dc74be0 DN |
5477 | } |
5478 | ||
4ffef5fe DN |
5479 | static int mem_cgroup_move_charge_pte_range(pmd_t *pmd, |
5480 | unsigned long addr, unsigned long end, | |
5481 | struct mm_walk *walk) | |
7dc74be0 | 5482 | { |
4ffef5fe DN |
5483 | int ret = 0; |
5484 | struct vm_area_struct *vma = walk->private; | |
5485 | pte_t *pte; | |
5486 | spinlock_t *ptl; | |
12724850 NH |
5487 | enum mc_target_type target_type; |
5488 | union mc_target target; | |
5489 | struct page *page; | |
5490 | struct page_cgroup *pc; | |
4ffef5fe | 5491 | |
12724850 NH |
5492 | /* |
5493 | * We don't take compound_lock() here but no race with splitting thp | |
5494 | * happens because: | |
5495 | * - if pmd_trans_huge_lock() returns 1, the relevant thp is not | |
5496 | * under splitting, which means there's no concurrent thp split, | |
5497 | * - if another thread runs into split_huge_page() just after we | |
5498 | * entered this if-block, the thread must wait for page table lock | |
5499 | * to be unlocked in __split_huge_page_splitting(), where the main | |
5500 | * part of thp split is not executed yet. | |
5501 | */ | |
5502 | if (pmd_trans_huge_lock(pmd, vma) == 1) { | |
62ade86a | 5503 | if (mc.precharge < HPAGE_PMD_NR) { |
12724850 NH |
5504 | spin_unlock(&vma->vm_mm->page_table_lock); |
5505 | return 0; | |
5506 | } | |
5507 | target_type = get_mctgt_type_thp(vma, addr, *pmd, &target); | |
5508 | if (target_type == MC_TARGET_PAGE) { | |
5509 | page = target.page; | |
5510 | if (!isolate_lru_page(page)) { | |
5511 | pc = lookup_page_cgroup(page); | |
5512 | if (!mem_cgroup_move_account(page, HPAGE_PMD_NR, | |
2f3479b1 | 5513 | pc, mc.from, mc.to)) { |
12724850 NH |
5514 | mc.precharge -= HPAGE_PMD_NR; |
5515 | mc.moved_charge += HPAGE_PMD_NR; | |
5516 | } | |
5517 | putback_lru_page(page); | |
5518 | } | |
5519 | put_page(page); | |
5520 | } | |
5521 | spin_unlock(&vma->vm_mm->page_table_lock); | |
1a5a9906 | 5522 | return 0; |
12724850 NH |
5523 | } |
5524 | ||
45f83cef AA |
5525 | if (pmd_trans_unstable(pmd)) |
5526 | return 0; | |
4ffef5fe DN |
5527 | retry: |
5528 | pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl); | |
5529 | for (; addr != end; addr += PAGE_SIZE) { | |
5530 | pte_t ptent = *(pte++); | |
02491447 | 5531 | swp_entry_t ent; |
4ffef5fe DN |
5532 | |
5533 | if (!mc.precharge) | |
5534 | break; | |
5535 | ||
8d32ff84 | 5536 | switch (get_mctgt_type(vma, addr, ptent, &target)) { |
4ffef5fe DN |
5537 | case MC_TARGET_PAGE: |
5538 | page = target.page; | |
5539 | if (isolate_lru_page(page)) | |
5540 | goto put; | |
5541 | pc = lookup_page_cgroup(page); | |
7ec99d62 | 5542 | if (!mem_cgroup_move_account(page, 1, pc, |
2f3479b1 | 5543 | mc.from, mc.to)) { |
4ffef5fe | 5544 | mc.precharge--; |
854ffa8d DN |
5545 | /* we uncharge from mc.from later. */ |
5546 | mc.moved_charge++; | |
4ffef5fe DN |
5547 | } |
5548 | putback_lru_page(page); | |
8d32ff84 | 5549 | put: /* get_mctgt_type() gets the page */ |
4ffef5fe DN |
5550 | put_page(page); |
5551 | break; | |
02491447 DN |
5552 | case MC_TARGET_SWAP: |
5553 | ent = target.ent; | |
e91cbb42 | 5554 | if (!mem_cgroup_move_swap_account(ent, mc.from, mc.to)) { |
02491447 | 5555 | mc.precharge--; |
483c30b5 DN |
5556 | /* we fixup refcnts and charges later. */ |
5557 | mc.moved_swap++; | |
5558 | } | |
02491447 | 5559 | break; |
4ffef5fe DN |
5560 | default: |
5561 | break; | |
5562 | } | |
5563 | } | |
5564 | pte_unmap_unlock(pte - 1, ptl); | |
5565 | cond_resched(); | |
5566 | ||
5567 | if (addr != end) { | |
5568 | /* | |
5569 | * We have consumed all precharges we got in can_attach(). | |
5570 | * We try charge one by one, but don't do any additional | |
5571 | * charges to mc.to if we have failed in charge once in attach() | |
5572 | * phase. | |
5573 | */ | |
854ffa8d | 5574 | ret = mem_cgroup_do_precharge(1); |
4ffef5fe DN |
5575 | if (!ret) |
5576 | goto retry; | |
5577 | } | |
5578 | ||
5579 | return ret; | |
5580 | } | |
5581 | ||
5582 | static void mem_cgroup_move_charge(struct mm_struct *mm) | |
5583 | { | |
5584 | struct vm_area_struct *vma; | |
5585 | ||
5586 | lru_add_drain_all(); | |
dfe076b0 DN |
5587 | retry: |
5588 | if (unlikely(!down_read_trylock(&mm->mmap_sem))) { | |
5589 | /* | |
5590 | * Someone who are holding the mmap_sem might be waiting in | |
5591 | * waitq. So we cancel all extra charges, wake up all waiters, | |
5592 | * and retry. Because we cancel precharges, we might not be able | |
5593 | * to move enough charges, but moving charge is a best-effort | |
5594 | * feature anyway, so it wouldn't be a big problem. | |
5595 | */ | |
5596 | __mem_cgroup_clear_mc(); | |
5597 | cond_resched(); | |
5598 | goto retry; | |
5599 | } | |
4ffef5fe DN |
5600 | for (vma = mm->mmap; vma; vma = vma->vm_next) { |
5601 | int ret; | |
5602 | struct mm_walk mem_cgroup_move_charge_walk = { | |
5603 | .pmd_entry = mem_cgroup_move_charge_pte_range, | |
5604 | .mm = mm, | |
5605 | .private = vma, | |
5606 | }; | |
5607 | if (is_vm_hugetlb_page(vma)) | |
5608 | continue; | |
4ffef5fe DN |
5609 | ret = walk_page_range(vma->vm_start, vma->vm_end, |
5610 | &mem_cgroup_move_charge_walk); | |
5611 | if (ret) | |
5612 | /* | |
5613 | * means we have consumed all precharges and failed in | |
5614 | * doing additional charge. Just abandon here. | |
5615 | */ | |
5616 | break; | |
5617 | } | |
dfe076b0 | 5618 | up_read(&mm->mmap_sem); |
7dc74be0 DN |
5619 | } |
5620 | ||
761b3ef5 LZ |
5621 | static void mem_cgroup_move_task(struct cgroup *cont, |
5622 | struct cgroup_taskset *tset) | |
67e465a7 | 5623 | { |
2f7ee569 | 5624 | struct task_struct *p = cgroup_taskset_first(tset); |
a433658c | 5625 | struct mm_struct *mm = get_task_mm(p); |
dfe076b0 | 5626 | |
dfe076b0 | 5627 | if (mm) { |
a433658c KM |
5628 | if (mc.to) |
5629 | mem_cgroup_move_charge(mm); | |
dfe076b0 DN |
5630 | mmput(mm); |
5631 | } | |
a433658c KM |
5632 | if (mc.to) |
5633 | mem_cgroup_clear_mc(); | |
67e465a7 | 5634 | } |
5cfb80a7 | 5635 | #else /* !CONFIG_MMU */ |
761b3ef5 LZ |
5636 | static int mem_cgroup_can_attach(struct cgroup *cgroup, |
5637 | struct cgroup_taskset *tset) | |
5cfb80a7 DN |
5638 | { |
5639 | return 0; | |
5640 | } | |
761b3ef5 LZ |
5641 | static void mem_cgroup_cancel_attach(struct cgroup *cgroup, |
5642 | struct cgroup_taskset *tset) | |
5cfb80a7 DN |
5643 | { |
5644 | } | |
761b3ef5 LZ |
5645 | static void mem_cgroup_move_task(struct cgroup *cont, |
5646 | struct cgroup_taskset *tset) | |
5cfb80a7 DN |
5647 | { |
5648 | } | |
5649 | #endif | |
67e465a7 | 5650 | |
8cdea7c0 BS |
5651 | struct cgroup_subsys mem_cgroup_subsys = { |
5652 | .name = "memory", | |
5653 | .subsys_id = mem_cgroup_subsys_id, | |
92fb9748 TH |
5654 | .css_alloc = mem_cgroup_css_alloc, |
5655 | .css_offline = mem_cgroup_css_offline, | |
5656 | .css_free = mem_cgroup_css_free, | |
7dc74be0 DN |
5657 | .can_attach = mem_cgroup_can_attach, |
5658 | .cancel_attach = mem_cgroup_cancel_attach, | |
67e465a7 | 5659 | .attach = mem_cgroup_move_task, |
6bc10349 | 5660 | .base_cftypes = mem_cgroup_files, |
6d12e2d8 | 5661 | .early_init = 0, |
04046e1a | 5662 | .use_id = 1, |
8cdea7c0 | 5663 | }; |
c077719b | 5664 | |
c255a458 | 5665 | #ifdef CONFIG_MEMCG_SWAP |
a42c390c MH |
5666 | static int __init enable_swap_account(char *s) |
5667 | { | |
5668 | /* consider enabled if no parameter or 1 is given */ | |
a2c8990a | 5669 | if (!strcmp(s, "1")) |
a42c390c | 5670 | really_do_swap_account = 1; |
a2c8990a | 5671 | else if (!strcmp(s, "0")) |
a42c390c MH |
5672 | really_do_swap_account = 0; |
5673 | return 1; | |
5674 | } | |
a2c8990a | 5675 | __setup("swapaccount=", enable_swap_account); |
c077719b | 5676 | |
c077719b | 5677 | #endif |