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8cdea7c0 BS |
1 | /* memcontrol.c - Memory Controller |
2 | * | |
3 | * Copyright IBM Corporation, 2007 | |
4 | * Author Balbir Singh <balbir@linux.vnet.ibm.com> | |
5 | * | |
78fb7466 PE |
6 | * Copyright 2007 OpenVZ SWsoft Inc |
7 | * Author: Pavel Emelianov <xemul@openvz.org> | |
8 | * | |
2e72b634 KS |
9 | * Memory thresholds |
10 | * Copyright (C) 2009 Nokia Corporation | |
11 | * Author: Kirill A. Shutemov | |
12 | * | |
7ae1e1d0 GC |
13 | * Kernel Memory Controller |
14 | * Copyright (C) 2012 Parallels Inc. and Google Inc. | |
15 | * Authors: Glauber Costa and Suleiman Souhlal | |
16 | * | |
8cdea7c0 BS |
17 | * This program is free software; you can redistribute it and/or modify |
18 | * it under the terms of the GNU General Public License as published by | |
19 | * the Free Software Foundation; either version 2 of the License, or | |
20 | * (at your option) any later version. | |
21 | * | |
22 | * This program is distributed in the hope that it will be useful, | |
23 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
24 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
25 | * GNU General Public License for more details. | |
26 | */ | |
27 | ||
3e32cb2e | 28 | #include <linux/page_counter.h> |
8cdea7c0 BS |
29 | #include <linux/memcontrol.h> |
30 | #include <linux/cgroup.h> | |
78fb7466 | 31 | #include <linux/mm.h> |
4ffef5fe | 32 | #include <linux/hugetlb.h> |
d13d1443 | 33 | #include <linux/pagemap.h> |
d52aa412 | 34 | #include <linux/smp.h> |
8a9f3ccd | 35 | #include <linux/page-flags.h> |
66e1707b | 36 | #include <linux/backing-dev.h> |
8a9f3ccd BS |
37 | #include <linux/bit_spinlock.h> |
38 | #include <linux/rcupdate.h> | |
e222432b | 39 | #include <linux/limits.h> |
b9e15baf | 40 | #include <linux/export.h> |
8c7c6e34 | 41 | #include <linux/mutex.h> |
bb4cc1a8 | 42 | #include <linux/rbtree.h> |
b6ac57d5 | 43 | #include <linux/slab.h> |
66e1707b | 44 | #include <linux/swap.h> |
02491447 | 45 | #include <linux/swapops.h> |
66e1707b | 46 | #include <linux/spinlock.h> |
2e72b634 | 47 | #include <linux/eventfd.h> |
79bd9814 | 48 | #include <linux/poll.h> |
2e72b634 | 49 | #include <linux/sort.h> |
66e1707b | 50 | #include <linux/fs.h> |
d2ceb9b7 | 51 | #include <linux/seq_file.h> |
70ddf637 | 52 | #include <linux/vmpressure.h> |
b69408e8 | 53 | #include <linux/mm_inline.h> |
5d1ea48b | 54 | #include <linux/swap_cgroup.h> |
cdec2e42 | 55 | #include <linux/cpu.h> |
158e0a2d | 56 | #include <linux/oom.h> |
0056f4e6 | 57 | #include <linux/lockdep.h> |
79bd9814 | 58 | #include <linux/file.h> |
08e552c6 | 59 | #include "internal.h" |
d1a4c0b3 | 60 | #include <net/sock.h> |
4bd2c1ee | 61 | #include <net/ip.h> |
d1a4c0b3 | 62 | #include <net/tcp_memcontrol.h> |
f35c3a8e | 63 | #include "slab.h" |
8cdea7c0 | 64 | |
8697d331 BS |
65 | #include <asm/uaccess.h> |
66 | ||
cc8e970c KM |
67 | #include <trace/events/vmscan.h> |
68 | ||
073219e9 TH |
69 | struct cgroup_subsys memory_cgrp_subsys __read_mostly; |
70 | EXPORT_SYMBOL(memory_cgrp_subsys); | |
68ae564b | 71 | |
a181b0e8 | 72 | #define MEM_CGROUP_RECLAIM_RETRIES 5 |
6bbda35c | 73 | static struct mem_cgroup *root_mem_cgroup __read_mostly; |
8cdea7c0 | 74 | |
21afa38e | 75 | /* Whether the swap controller is active */ |
c255a458 | 76 | #ifdef CONFIG_MEMCG_SWAP |
c077719b | 77 | int do_swap_account __read_mostly; |
c077719b | 78 | #else |
a0db00fc | 79 | #define do_swap_account 0 |
c077719b KH |
80 | #endif |
81 | ||
af7c4b0e JW |
82 | static const char * const mem_cgroup_stat_names[] = { |
83 | "cache", | |
84 | "rss", | |
b070e65c | 85 | "rss_huge", |
af7c4b0e | 86 | "mapped_file", |
3ea67d06 | 87 | "writeback", |
af7c4b0e JW |
88 | "swap", |
89 | }; | |
90 | ||
af7c4b0e JW |
91 | static const char * const mem_cgroup_events_names[] = { |
92 | "pgpgin", | |
93 | "pgpgout", | |
94 | "pgfault", | |
95 | "pgmajfault", | |
96 | }; | |
97 | ||
58cf188e SZ |
98 | static const char * const mem_cgroup_lru_names[] = { |
99 | "inactive_anon", | |
100 | "active_anon", | |
101 | "inactive_file", | |
102 | "active_file", | |
103 | "unevictable", | |
104 | }; | |
105 | ||
7a159cc9 JW |
106 | /* |
107 | * Per memcg event counter is incremented at every pagein/pageout. With THP, | |
108 | * it will be incremated by the number of pages. This counter is used for | |
109 | * for trigger some periodic events. This is straightforward and better | |
110 | * than using jiffies etc. to handle periodic memcg event. | |
111 | */ | |
112 | enum mem_cgroup_events_target { | |
113 | MEM_CGROUP_TARGET_THRESH, | |
bb4cc1a8 | 114 | MEM_CGROUP_TARGET_SOFTLIMIT, |
453a9bf3 | 115 | MEM_CGROUP_TARGET_NUMAINFO, |
7a159cc9 JW |
116 | MEM_CGROUP_NTARGETS, |
117 | }; | |
a0db00fc KS |
118 | #define THRESHOLDS_EVENTS_TARGET 128 |
119 | #define SOFTLIMIT_EVENTS_TARGET 1024 | |
120 | #define NUMAINFO_EVENTS_TARGET 1024 | |
e9f8974f | 121 | |
d52aa412 | 122 | struct mem_cgroup_stat_cpu { |
7a159cc9 | 123 | long count[MEM_CGROUP_STAT_NSTATS]; |
241994ed | 124 | unsigned long events[MEMCG_NR_EVENTS]; |
13114716 | 125 | unsigned long nr_page_events; |
7a159cc9 | 126 | unsigned long targets[MEM_CGROUP_NTARGETS]; |
d52aa412 KH |
127 | }; |
128 | ||
5ac8fb31 JW |
129 | struct reclaim_iter { |
130 | struct mem_cgroup *position; | |
527a5ec9 JW |
131 | /* scan generation, increased every round-trip */ |
132 | unsigned int generation; | |
133 | }; | |
134 | ||
6d12e2d8 KH |
135 | /* |
136 | * per-zone information in memory controller. | |
137 | */ | |
6d12e2d8 | 138 | struct mem_cgroup_per_zone { |
6290df54 | 139 | struct lruvec lruvec; |
1eb49272 | 140 | unsigned long lru_size[NR_LRU_LISTS]; |
3e2f41f1 | 141 | |
5ac8fb31 | 142 | struct reclaim_iter iter[DEF_PRIORITY + 1]; |
527a5ec9 | 143 | |
bb4cc1a8 | 144 | struct rb_node tree_node; /* RB tree node */ |
3e32cb2e | 145 | unsigned long usage_in_excess;/* Set to the value by which */ |
bb4cc1a8 AM |
146 | /* the soft limit is exceeded*/ |
147 | bool on_tree; | |
d79154bb | 148 | struct mem_cgroup *memcg; /* Back pointer, we cannot */ |
4e416953 | 149 | /* use container_of */ |
6d12e2d8 | 150 | }; |
6d12e2d8 KH |
151 | |
152 | struct mem_cgroup_per_node { | |
153 | struct mem_cgroup_per_zone zoneinfo[MAX_NR_ZONES]; | |
154 | }; | |
155 | ||
bb4cc1a8 AM |
156 | /* |
157 | * Cgroups above their limits are maintained in a RB-Tree, independent of | |
158 | * their hierarchy representation | |
159 | */ | |
160 | ||
161 | struct mem_cgroup_tree_per_zone { | |
162 | struct rb_root rb_root; | |
163 | spinlock_t lock; | |
164 | }; | |
165 | ||
166 | struct mem_cgroup_tree_per_node { | |
167 | struct mem_cgroup_tree_per_zone rb_tree_per_zone[MAX_NR_ZONES]; | |
168 | }; | |
169 | ||
170 | struct mem_cgroup_tree { | |
171 | struct mem_cgroup_tree_per_node *rb_tree_per_node[MAX_NUMNODES]; | |
172 | }; | |
173 | ||
174 | static struct mem_cgroup_tree soft_limit_tree __read_mostly; | |
175 | ||
2e72b634 KS |
176 | struct mem_cgroup_threshold { |
177 | struct eventfd_ctx *eventfd; | |
3e32cb2e | 178 | unsigned long threshold; |
2e72b634 KS |
179 | }; |
180 | ||
9490ff27 | 181 | /* For threshold */ |
2e72b634 | 182 | struct mem_cgroup_threshold_ary { |
748dad36 | 183 | /* An array index points to threshold just below or equal to usage. */ |
5407a562 | 184 | int current_threshold; |
2e72b634 KS |
185 | /* Size of entries[] */ |
186 | unsigned int size; | |
187 | /* Array of thresholds */ | |
188 | struct mem_cgroup_threshold entries[0]; | |
189 | }; | |
2c488db2 KS |
190 | |
191 | struct mem_cgroup_thresholds { | |
192 | /* Primary thresholds array */ | |
193 | struct mem_cgroup_threshold_ary *primary; | |
194 | /* | |
195 | * Spare threshold array. | |
196 | * This is needed to make mem_cgroup_unregister_event() "never fail". | |
197 | * It must be able to store at least primary->size - 1 entries. | |
198 | */ | |
199 | struct mem_cgroup_threshold_ary *spare; | |
200 | }; | |
201 | ||
9490ff27 KH |
202 | /* for OOM */ |
203 | struct mem_cgroup_eventfd_list { | |
204 | struct list_head list; | |
205 | struct eventfd_ctx *eventfd; | |
206 | }; | |
2e72b634 | 207 | |
79bd9814 TH |
208 | /* |
209 | * cgroup_event represents events which userspace want to receive. | |
210 | */ | |
3bc942f3 | 211 | struct mem_cgroup_event { |
79bd9814 | 212 | /* |
59b6f873 | 213 | * memcg which the event belongs to. |
79bd9814 | 214 | */ |
59b6f873 | 215 | struct mem_cgroup *memcg; |
79bd9814 TH |
216 | /* |
217 | * eventfd to signal userspace about the event. | |
218 | */ | |
219 | struct eventfd_ctx *eventfd; | |
220 | /* | |
221 | * Each of these stored in a list by the cgroup. | |
222 | */ | |
223 | struct list_head list; | |
fba94807 TH |
224 | /* |
225 | * register_event() callback will be used to add new userspace | |
226 | * waiter for changes related to this event. Use eventfd_signal() | |
227 | * on eventfd to send notification to userspace. | |
228 | */ | |
59b6f873 | 229 | int (*register_event)(struct mem_cgroup *memcg, |
347c4a87 | 230 | struct eventfd_ctx *eventfd, const char *args); |
fba94807 TH |
231 | /* |
232 | * unregister_event() callback will be called when userspace closes | |
233 | * the eventfd or on cgroup removing. This callback must be set, | |
234 | * if you want provide notification functionality. | |
235 | */ | |
59b6f873 | 236 | void (*unregister_event)(struct mem_cgroup *memcg, |
fba94807 | 237 | struct eventfd_ctx *eventfd); |
79bd9814 TH |
238 | /* |
239 | * All fields below needed to unregister event when | |
240 | * userspace closes eventfd. | |
241 | */ | |
242 | poll_table pt; | |
243 | wait_queue_head_t *wqh; | |
244 | wait_queue_t wait; | |
245 | struct work_struct remove; | |
246 | }; | |
247 | ||
c0ff4b85 R |
248 | static void mem_cgroup_threshold(struct mem_cgroup *memcg); |
249 | static void mem_cgroup_oom_notify(struct mem_cgroup *memcg); | |
2e72b634 | 250 | |
8cdea7c0 BS |
251 | /* |
252 | * The memory controller data structure. The memory controller controls both | |
253 | * page cache and RSS per cgroup. We would eventually like to provide | |
254 | * statistics based on the statistics developed by Rik Van Riel for clock-pro, | |
255 | * to help the administrator determine what knobs to tune. | |
256 | * | |
257 | * TODO: Add a water mark for the memory controller. Reclaim will begin when | |
8a9f3ccd BS |
258 | * we hit the water mark. May be even add a low water mark, such that |
259 | * no reclaim occurs from a cgroup at it's low water mark, this is | |
260 | * a feature that will be implemented much later in the future. | |
8cdea7c0 BS |
261 | */ |
262 | struct mem_cgroup { | |
263 | struct cgroup_subsys_state css; | |
3e32cb2e JW |
264 | |
265 | /* Accounted resources */ | |
266 | struct page_counter memory; | |
267 | struct page_counter memsw; | |
268 | struct page_counter kmem; | |
269 | ||
241994ed JW |
270 | /* Normal memory consumption range */ |
271 | unsigned long low; | |
272 | unsigned long high; | |
273 | ||
3e32cb2e | 274 | unsigned long soft_limit; |
59927fb9 | 275 | |
70ddf637 AV |
276 | /* vmpressure notifications */ |
277 | struct vmpressure vmpressure; | |
278 | ||
2f7dd7a4 JW |
279 | /* css_online() has been completed */ |
280 | int initialized; | |
281 | ||
18f59ea7 BS |
282 | /* |
283 | * Should the accounting and control be hierarchical, per subtree? | |
284 | */ | |
285 | bool use_hierarchy; | |
79dfdacc MH |
286 | |
287 | bool oom_lock; | |
288 | atomic_t under_oom; | |
3812c8c8 | 289 | atomic_t oom_wakeups; |
79dfdacc | 290 | |
1f4c025b | 291 | int swappiness; |
3c11ecf4 KH |
292 | /* OOM-Killer disable */ |
293 | int oom_kill_disable; | |
a7885eb8 | 294 | |
2e72b634 KS |
295 | /* protect arrays of thresholds */ |
296 | struct mutex thresholds_lock; | |
297 | ||
298 | /* thresholds for memory usage. RCU-protected */ | |
2c488db2 | 299 | struct mem_cgroup_thresholds thresholds; |
907860ed | 300 | |
2e72b634 | 301 | /* thresholds for mem+swap usage. RCU-protected */ |
2c488db2 | 302 | struct mem_cgroup_thresholds memsw_thresholds; |
907860ed | 303 | |
9490ff27 KH |
304 | /* For oom notifier event fd */ |
305 | struct list_head oom_notify; | |
185efc0f | 306 | |
7dc74be0 DN |
307 | /* |
308 | * Should we move charges of a task when a task is moved into this | |
309 | * mem_cgroup ? And what type of charges should we move ? | |
310 | */ | |
f894ffa8 | 311 | unsigned long move_charge_at_immigrate; |
619d094b KH |
312 | /* |
313 | * set > 0 if pages under this cgroup are moving to other cgroup. | |
314 | */ | |
6de22619 | 315 | atomic_t moving_account; |
312734c0 | 316 | /* taken only while moving_account > 0 */ |
6de22619 JW |
317 | spinlock_t move_lock; |
318 | struct task_struct *move_lock_task; | |
319 | unsigned long move_lock_flags; | |
d52aa412 | 320 | /* |
c62b1a3b | 321 | * percpu counter. |
d52aa412 | 322 | */ |
3a7951b4 | 323 | struct mem_cgroup_stat_cpu __percpu *stat; |
711d3d2c KH |
324 | /* |
325 | * used when a cpu is offlined or other synchronizations | |
326 | * See mem_cgroup_read_stat(). | |
327 | */ | |
328 | struct mem_cgroup_stat_cpu nocpu_base; | |
329 | spinlock_t pcp_counter_lock; | |
d1a4c0b3 | 330 | |
4bd2c1ee | 331 | #if defined(CONFIG_MEMCG_KMEM) && defined(CONFIG_INET) |
2e685cad | 332 | struct cg_proto tcp_mem; |
d1a4c0b3 | 333 | #endif |
2633d7a0 | 334 | #if defined(CONFIG_MEMCG_KMEM) |
2633d7a0 GC |
335 | /* Index in the kmem_cache->memcg_params->memcg_caches array */ |
336 | int kmemcg_id; | |
337 | #endif | |
45cf7ebd GC |
338 | |
339 | int last_scanned_node; | |
340 | #if MAX_NUMNODES > 1 | |
341 | nodemask_t scan_nodes; | |
342 | atomic_t numainfo_events; | |
343 | atomic_t numainfo_updating; | |
344 | #endif | |
70ddf637 | 345 | |
fba94807 TH |
346 | /* List of events which userspace want to receive */ |
347 | struct list_head event_list; | |
348 | spinlock_t event_list_lock; | |
349 | ||
54f72fe0 JW |
350 | struct mem_cgroup_per_node *nodeinfo[0]; |
351 | /* WARNING: nodeinfo must be the last member here */ | |
8cdea7c0 BS |
352 | }; |
353 | ||
510fc4e1 | 354 | #ifdef CONFIG_MEMCG_KMEM |
7de37682 GC |
355 | static bool memcg_kmem_is_active(struct mem_cgroup *memcg) |
356 | { | |
900a38f0 | 357 | return memcg->kmemcg_id >= 0; |
7de37682 | 358 | } |
510fc4e1 GC |
359 | #endif |
360 | ||
7dc74be0 DN |
361 | /* Stuffs for move charges at task migration. */ |
362 | /* | |
1dfab5ab | 363 | * Types of charges to be moved. |
7dc74be0 | 364 | */ |
1dfab5ab JW |
365 | #define MOVE_ANON 0x1U |
366 | #define MOVE_FILE 0x2U | |
367 | #define MOVE_MASK (MOVE_ANON | MOVE_FILE) | |
7dc74be0 | 368 | |
4ffef5fe DN |
369 | /* "mc" and its members are protected by cgroup_mutex */ |
370 | static struct move_charge_struct { | |
b1dd693e | 371 | spinlock_t lock; /* for from, to */ |
4ffef5fe DN |
372 | struct mem_cgroup *from; |
373 | struct mem_cgroup *to; | |
1dfab5ab | 374 | unsigned long flags; |
4ffef5fe | 375 | unsigned long precharge; |
854ffa8d | 376 | unsigned long moved_charge; |
483c30b5 | 377 | unsigned long moved_swap; |
8033b97c DN |
378 | struct task_struct *moving_task; /* a task moving charges */ |
379 | wait_queue_head_t waitq; /* a waitq for other context */ | |
380 | } mc = { | |
2bd9bb20 | 381 | .lock = __SPIN_LOCK_UNLOCKED(mc.lock), |
8033b97c DN |
382 | .waitq = __WAIT_QUEUE_HEAD_INITIALIZER(mc.waitq), |
383 | }; | |
4ffef5fe | 384 | |
4e416953 BS |
385 | /* |
386 | * Maximum loops in mem_cgroup_hierarchical_reclaim(), used for soft | |
387 | * limit reclaim to prevent infinite loops, if they ever occur. | |
388 | */ | |
a0db00fc | 389 | #define MEM_CGROUP_MAX_RECLAIM_LOOPS 100 |
bb4cc1a8 | 390 | #define MEM_CGROUP_MAX_SOFT_LIMIT_RECLAIM_LOOPS 2 |
4e416953 | 391 | |
217bc319 KH |
392 | enum charge_type { |
393 | MEM_CGROUP_CHARGE_TYPE_CACHE = 0, | |
41326c17 | 394 | MEM_CGROUP_CHARGE_TYPE_ANON, |
d13d1443 | 395 | MEM_CGROUP_CHARGE_TYPE_SWAPOUT, /* for accounting swapcache */ |
8a9478ca | 396 | MEM_CGROUP_CHARGE_TYPE_DROP, /* a page was unused swap cache */ |
c05555b5 KH |
397 | NR_CHARGE_TYPE, |
398 | }; | |
399 | ||
8c7c6e34 | 400 | /* for encoding cft->private value on file */ |
86ae53e1 GC |
401 | enum res_type { |
402 | _MEM, | |
403 | _MEMSWAP, | |
404 | _OOM_TYPE, | |
510fc4e1 | 405 | _KMEM, |
86ae53e1 GC |
406 | }; |
407 | ||
a0db00fc KS |
408 | #define MEMFILE_PRIVATE(x, val) ((x) << 16 | (val)) |
409 | #define MEMFILE_TYPE(val) ((val) >> 16 & 0xffff) | |
8c7c6e34 | 410 | #define MEMFILE_ATTR(val) ((val) & 0xffff) |
9490ff27 KH |
411 | /* Used for OOM nofiier */ |
412 | #define OOM_CONTROL (0) | |
8c7c6e34 | 413 | |
0999821b GC |
414 | /* |
415 | * The memcg_create_mutex will be held whenever a new cgroup is created. | |
416 | * As a consequence, any change that needs to protect against new child cgroups | |
417 | * appearing has to hold it as well. | |
418 | */ | |
419 | static DEFINE_MUTEX(memcg_create_mutex); | |
420 | ||
b2145145 WL |
421 | struct mem_cgroup *mem_cgroup_from_css(struct cgroup_subsys_state *s) |
422 | { | |
a7c6d554 | 423 | return s ? container_of(s, struct mem_cgroup, css) : NULL; |
b2145145 WL |
424 | } |
425 | ||
70ddf637 AV |
426 | /* Some nice accessors for the vmpressure. */ |
427 | struct vmpressure *memcg_to_vmpressure(struct mem_cgroup *memcg) | |
428 | { | |
429 | if (!memcg) | |
430 | memcg = root_mem_cgroup; | |
431 | return &memcg->vmpressure; | |
432 | } | |
433 | ||
434 | struct cgroup_subsys_state *vmpressure_to_css(struct vmpressure *vmpr) | |
435 | { | |
436 | return &container_of(vmpr, struct mem_cgroup, vmpressure)->css; | |
437 | } | |
438 | ||
7ffc0edc MH |
439 | static inline bool mem_cgroup_is_root(struct mem_cgroup *memcg) |
440 | { | |
441 | return (memcg == root_mem_cgroup); | |
442 | } | |
443 | ||
4219b2da LZ |
444 | /* |
445 | * We restrict the id in the range of [1, 65535], so it can fit into | |
446 | * an unsigned short. | |
447 | */ | |
448 | #define MEM_CGROUP_ID_MAX USHRT_MAX | |
449 | ||
34c00c31 LZ |
450 | static inline unsigned short mem_cgroup_id(struct mem_cgroup *memcg) |
451 | { | |
15a4c835 | 452 | return memcg->css.id; |
34c00c31 LZ |
453 | } |
454 | ||
455 | static inline struct mem_cgroup *mem_cgroup_from_id(unsigned short id) | |
456 | { | |
457 | struct cgroup_subsys_state *css; | |
458 | ||
7d699ddb | 459 | css = css_from_id(id, &memory_cgrp_subsys); |
34c00c31 LZ |
460 | return mem_cgroup_from_css(css); |
461 | } | |
462 | ||
e1aab161 | 463 | /* Writing them here to avoid exposing memcg's inner layout */ |
4bd2c1ee | 464 | #if defined(CONFIG_INET) && defined(CONFIG_MEMCG_KMEM) |
e1aab161 | 465 | |
e1aab161 GC |
466 | void sock_update_memcg(struct sock *sk) |
467 | { | |
376be5ff | 468 | if (mem_cgroup_sockets_enabled) { |
e1aab161 | 469 | struct mem_cgroup *memcg; |
3f134619 | 470 | struct cg_proto *cg_proto; |
e1aab161 GC |
471 | |
472 | BUG_ON(!sk->sk_prot->proto_cgroup); | |
473 | ||
f3f511e1 GC |
474 | /* Socket cloning can throw us here with sk_cgrp already |
475 | * filled. It won't however, necessarily happen from | |
476 | * process context. So the test for root memcg given | |
477 | * the current task's memcg won't help us in this case. | |
478 | * | |
479 | * Respecting the original socket's memcg is a better | |
480 | * decision in this case. | |
481 | */ | |
482 | if (sk->sk_cgrp) { | |
483 | BUG_ON(mem_cgroup_is_root(sk->sk_cgrp->memcg)); | |
5347e5ae | 484 | css_get(&sk->sk_cgrp->memcg->css); |
f3f511e1 GC |
485 | return; |
486 | } | |
487 | ||
e1aab161 GC |
488 | rcu_read_lock(); |
489 | memcg = mem_cgroup_from_task(current); | |
3f134619 | 490 | cg_proto = sk->sk_prot->proto_cgroup(memcg); |
5347e5ae | 491 | if (!mem_cgroup_is_root(memcg) && |
ec903c0c TH |
492 | memcg_proto_active(cg_proto) && |
493 | css_tryget_online(&memcg->css)) { | |
3f134619 | 494 | sk->sk_cgrp = cg_proto; |
e1aab161 GC |
495 | } |
496 | rcu_read_unlock(); | |
497 | } | |
498 | } | |
499 | EXPORT_SYMBOL(sock_update_memcg); | |
500 | ||
501 | void sock_release_memcg(struct sock *sk) | |
502 | { | |
376be5ff | 503 | if (mem_cgroup_sockets_enabled && sk->sk_cgrp) { |
e1aab161 GC |
504 | struct mem_cgroup *memcg; |
505 | WARN_ON(!sk->sk_cgrp->memcg); | |
506 | memcg = sk->sk_cgrp->memcg; | |
5347e5ae | 507 | css_put(&sk->sk_cgrp->memcg->css); |
e1aab161 GC |
508 | } |
509 | } | |
d1a4c0b3 GC |
510 | |
511 | struct cg_proto *tcp_proto_cgroup(struct mem_cgroup *memcg) | |
512 | { | |
513 | if (!memcg || mem_cgroup_is_root(memcg)) | |
514 | return NULL; | |
515 | ||
2e685cad | 516 | return &memcg->tcp_mem; |
d1a4c0b3 GC |
517 | } |
518 | EXPORT_SYMBOL(tcp_proto_cgroup); | |
e1aab161 | 519 | |
3f134619 GC |
520 | static void disarm_sock_keys(struct mem_cgroup *memcg) |
521 | { | |
2e685cad | 522 | if (!memcg_proto_activated(&memcg->tcp_mem)) |
3f134619 GC |
523 | return; |
524 | static_key_slow_dec(&memcg_socket_limit_enabled); | |
525 | } | |
526 | #else | |
527 | static void disarm_sock_keys(struct mem_cgroup *memcg) | |
528 | { | |
529 | } | |
530 | #endif | |
531 | ||
a8964b9b | 532 | #ifdef CONFIG_MEMCG_KMEM |
55007d84 GC |
533 | /* |
534 | * This will be the memcg's index in each cache's ->memcg_params->memcg_caches. | |
b8627835 LZ |
535 | * The main reason for not using cgroup id for this: |
536 | * this works better in sparse environments, where we have a lot of memcgs, | |
537 | * but only a few kmem-limited. Or also, if we have, for instance, 200 | |
538 | * memcgs, and none but the 200th is kmem-limited, we'd have to have a | |
539 | * 200 entry array for that. | |
55007d84 GC |
540 | * |
541 | * The current size of the caches array is stored in | |
542 | * memcg_limited_groups_array_size. It will double each time we have to | |
543 | * increase it. | |
544 | */ | |
545 | static DEFINE_IDA(kmem_limited_groups); | |
749c5415 GC |
546 | int memcg_limited_groups_array_size; |
547 | ||
55007d84 GC |
548 | /* |
549 | * MIN_SIZE is different than 1, because we would like to avoid going through | |
550 | * the alloc/free process all the time. In a small machine, 4 kmem-limited | |
551 | * cgroups is a reasonable guess. In the future, it could be a parameter or | |
552 | * tunable, but that is strictly not necessary. | |
553 | * | |
b8627835 | 554 | * MAX_SIZE should be as large as the number of cgrp_ids. Ideally, we could get |
55007d84 GC |
555 | * this constant directly from cgroup, but it is understandable that this is |
556 | * better kept as an internal representation in cgroup.c. In any case, the | |
b8627835 | 557 | * cgrp_id space is not getting any smaller, and we don't have to necessarily |
55007d84 GC |
558 | * increase ours as well if it increases. |
559 | */ | |
560 | #define MEMCG_CACHES_MIN_SIZE 4 | |
b8627835 | 561 | #define MEMCG_CACHES_MAX_SIZE MEM_CGROUP_ID_MAX |
55007d84 | 562 | |
d7f25f8a GC |
563 | /* |
564 | * A lot of the calls to the cache allocation functions are expected to be | |
565 | * inlined by the compiler. Since the calls to memcg_kmem_get_cache are | |
566 | * conditional to this static branch, we'll have to allow modules that does | |
567 | * kmem_cache_alloc and the such to see this symbol as well | |
568 | */ | |
a8964b9b | 569 | struct static_key memcg_kmem_enabled_key; |
d7f25f8a | 570 | EXPORT_SYMBOL(memcg_kmem_enabled_key); |
a8964b9b | 571 | |
f3bb3043 VD |
572 | static void memcg_free_cache_id(int id); |
573 | ||
a8964b9b GC |
574 | static void disarm_kmem_keys(struct mem_cgroup *memcg) |
575 | { | |
55007d84 | 576 | if (memcg_kmem_is_active(memcg)) { |
a8964b9b | 577 | static_key_slow_dec(&memcg_kmem_enabled_key); |
f3bb3043 | 578 | memcg_free_cache_id(memcg->kmemcg_id); |
55007d84 | 579 | } |
bea207c8 GC |
580 | /* |
581 | * This check can't live in kmem destruction function, | |
582 | * since the charges will outlive the cgroup | |
583 | */ | |
3e32cb2e | 584 | WARN_ON(page_counter_read(&memcg->kmem)); |
a8964b9b GC |
585 | } |
586 | #else | |
587 | static void disarm_kmem_keys(struct mem_cgroup *memcg) | |
588 | { | |
589 | } | |
590 | #endif /* CONFIG_MEMCG_KMEM */ | |
591 | ||
592 | static void disarm_static_keys(struct mem_cgroup *memcg) | |
593 | { | |
594 | disarm_sock_keys(memcg); | |
595 | disarm_kmem_keys(memcg); | |
596 | } | |
597 | ||
f64c3f54 | 598 | static struct mem_cgroup_per_zone * |
e231875b | 599 | mem_cgroup_zone_zoneinfo(struct mem_cgroup *memcg, struct zone *zone) |
f64c3f54 | 600 | { |
e231875b JZ |
601 | int nid = zone_to_nid(zone); |
602 | int zid = zone_idx(zone); | |
603 | ||
54f72fe0 | 604 | return &memcg->nodeinfo[nid]->zoneinfo[zid]; |
f64c3f54 BS |
605 | } |
606 | ||
c0ff4b85 | 607 | struct cgroup_subsys_state *mem_cgroup_css(struct mem_cgroup *memcg) |
d324236b | 608 | { |
c0ff4b85 | 609 | return &memcg->css; |
d324236b WF |
610 | } |
611 | ||
f64c3f54 | 612 | static struct mem_cgroup_per_zone * |
e231875b | 613 | mem_cgroup_page_zoneinfo(struct mem_cgroup *memcg, struct page *page) |
f64c3f54 | 614 | { |
97a6c37b JW |
615 | int nid = page_to_nid(page); |
616 | int zid = page_zonenum(page); | |
f64c3f54 | 617 | |
e231875b | 618 | return &memcg->nodeinfo[nid]->zoneinfo[zid]; |
f64c3f54 BS |
619 | } |
620 | ||
bb4cc1a8 AM |
621 | static struct mem_cgroup_tree_per_zone * |
622 | soft_limit_tree_node_zone(int nid, int zid) | |
623 | { | |
624 | return &soft_limit_tree.rb_tree_per_node[nid]->rb_tree_per_zone[zid]; | |
625 | } | |
626 | ||
627 | static struct mem_cgroup_tree_per_zone * | |
628 | soft_limit_tree_from_page(struct page *page) | |
629 | { | |
630 | int nid = page_to_nid(page); | |
631 | int zid = page_zonenum(page); | |
632 | ||
633 | return &soft_limit_tree.rb_tree_per_node[nid]->rb_tree_per_zone[zid]; | |
634 | } | |
635 | ||
cf2c8127 JW |
636 | static void __mem_cgroup_insert_exceeded(struct mem_cgroup_per_zone *mz, |
637 | struct mem_cgroup_tree_per_zone *mctz, | |
3e32cb2e | 638 | unsigned long new_usage_in_excess) |
bb4cc1a8 AM |
639 | { |
640 | struct rb_node **p = &mctz->rb_root.rb_node; | |
641 | struct rb_node *parent = NULL; | |
642 | struct mem_cgroup_per_zone *mz_node; | |
643 | ||
644 | if (mz->on_tree) | |
645 | return; | |
646 | ||
647 | mz->usage_in_excess = new_usage_in_excess; | |
648 | if (!mz->usage_in_excess) | |
649 | return; | |
650 | while (*p) { | |
651 | parent = *p; | |
652 | mz_node = rb_entry(parent, struct mem_cgroup_per_zone, | |
653 | tree_node); | |
654 | if (mz->usage_in_excess < mz_node->usage_in_excess) | |
655 | p = &(*p)->rb_left; | |
656 | /* | |
657 | * We can't avoid mem cgroups that are over their soft | |
658 | * limit by the same amount | |
659 | */ | |
660 | else if (mz->usage_in_excess >= mz_node->usage_in_excess) | |
661 | p = &(*p)->rb_right; | |
662 | } | |
663 | rb_link_node(&mz->tree_node, parent, p); | |
664 | rb_insert_color(&mz->tree_node, &mctz->rb_root); | |
665 | mz->on_tree = true; | |
666 | } | |
667 | ||
cf2c8127 JW |
668 | static void __mem_cgroup_remove_exceeded(struct mem_cgroup_per_zone *mz, |
669 | struct mem_cgroup_tree_per_zone *mctz) | |
bb4cc1a8 AM |
670 | { |
671 | if (!mz->on_tree) | |
672 | return; | |
673 | rb_erase(&mz->tree_node, &mctz->rb_root); | |
674 | mz->on_tree = false; | |
675 | } | |
676 | ||
cf2c8127 JW |
677 | static void mem_cgroup_remove_exceeded(struct mem_cgroup_per_zone *mz, |
678 | struct mem_cgroup_tree_per_zone *mctz) | |
bb4cc1a8 | 679 | { |
0a31bc97 JW |
680 | unsigned long flags; |
681 | ||
682 | spin_lock_irqsave(&mctz->lock, flags); | |
cf2c8127 | 683 | __mem_cgroup_remove_exceeded(mz, mctz); |
0a31bc97 | 684 | spin_unlock_irqrestore(&mctz->lock, flags); |
bb4cc1a8 AM |
685 | } |
686 | ||
3e32cb2e JW |
687 | static unsigned long soft_limit_excess(struct mem_cgroup *memcg) |
688 | { | |
689 | unsigned long nr_pages = page_counter_read(&memcg->memory); | |
690 | unsigned long soft_limit = ACCESS_ONCE(memcg->soft_limit); | |
691 | unsigned long excess = 0; | |
692 | ||
693 | if (nr_pages > soft_limit) | |
694 | excess = nr_pages - soft_limit; | |
695 | ||
696 | return excess; | |
697 | } | |
bb4cc1a8 AM |
698 | |
699 | static void mem_cgroup_update_tree(struct mem_cgroup *memcg, struct page *page) | |
700 | { | |
3e32cb2e | 701 | unsigned long excess; |
bb4cc1a8 AM |
702 | struct mem_cgroup_per_zone *mz; |
703 | struct mem_cgroup_tree_per_zone *mctz; | |
bb4cc1a8 | 704 | |
e231875b | 705 | mctz = soft_limit_tree_from_page(page); |
bb4cc1a8 AM |
706 | /* |
707 | * Necessary to update all ancestors when hierarchy is used. | |
708 | * because their event counter is not touched. | |
709 | */ | |
710 | for (; memcg; memcg = parent_mem_cgroup(memcg)) { | |
e231875b | 711 | mz = mem_cgroup_page_zoneinfo(memcg, page); |
3e32cb2e | 712 | excess = soft_limit_excess(memcg); |
bb4cc1a8 AM |
713 | /* |
714 | * We have to update the tree if mz is on RB-tree or | |
715 | * mem is over its softlimit. | |
716 | */ | |
717 | if (excess || mz->on_tree) { | |
0a31bc97 JW |
718 | unsigned long flags; |
719 | ||
720 | spin_lock_irqsave(&mctz->lock, flags); | |
bb4cc1a8 AM |
721 | /* if on-tree, remove it */ |
722 | if (mz->on_tree) | |
cf2c8127 | 723 | __mem_cgroup_remove_exceeded(mz, mctz); |
bb4cc1a8 AM |
724 | /* |
725 | * Insert again. mz->usage_in_excess will be updated. | |
726 | * If excess is 0, no tree ops. | |
727 | */ | |
cf2c8127 | 728 | __mem_cgroup_insert_exceeded(mz, mctz, excess); |
0a31bc97 | 729 | spin_unlock_irqrestore(&mctz->lock, flags); |
bb4cc1a8 AM |
730 | } |
731 | } | |
732 | } | |
733 | ||
734 | static void mem_cgroup_remove_from_trees(struct mem_cgroup *memcg) | |
735 | { | |
bb4cc1a8 | 736 | struct mem_cgroup_tree_per_zone *mctz; |
e231875b JZ |
737 | struct mem_cgroup_per_zone *mz; |
738 | int nid, zid; | |
bb4cc1a8 | 739 | |
e231875b JZ |
740 | for_each_node(nid) { |
741 | for (zid = 0; zid < MAX_NR_ZONES; zid++) { | |
742 | mz = &memcg->nodeinfo[nid]->zoneinfo[zid]; | |
743 | mctz = soft_limit_tree_node_zone(nid, zid); | |
cf2c8127 | 744 | mem_cgroup_remove_exceeded(mz, mctz); |
bb4cc1a8 AM |
745 | } |
746 | } | |
747 | } | |
748 | ||
749 | static struct mem_cgroup_per_zone * | |
750 | __mem_cgroup_largest_soft_limit_node(struct mem_cgroup_tree_per_zone *mctz) | |
751 | { | |
752 | struct rb_node *rightmost = NULL; | |
753 | struct mem_cgroup_per_zone *mz; | |
754 | ||
755 | retry: | |
756 | mz = NULL; | |
757 | rightmost = rb_last(&mctz->rb_root); | |
758 | if (!rightmost) | |
759 | goto done; /* Nothing to reclaim from */ | |
760 | ||
761 | mz = rb_entry(rightmost, struct mem_cgroup_per_zone, tree_node); | |
762 | /* | |
763 | * Remove the node now but someone else can add it back, | |
764 | * we will to add it back at the end of reclaim to its correct | |
765 | * position in the tree. | |
766 | */ | |
cf2c8127 | 767 | __mem_cgroup_remove_exceeded(mz, mctz); |
3e32cb2e | 768 | if (!soft_limit_excess(mz->memcg) || |
ec903c0c | 769 | !css_tryget_online(&mz->memcg->css)) |
bb4cc1a8 AM |
770 | goto retry; |
771 | done: | |
772 | return mz; | |
773 | } | |
774 | ||
775 | static struct mem_cgroup_per_zone * | |
776 | mem_cgroup_largest_soft_limit_node(struct mem_cgroup_tree_per_zone *mctz) | |
777 | { | |
778 | struct mem_cgroup_per_zone *mz; | |
779 | ||
0a31bc97 | 780 | spin_lock_irq(&mctz->lock); |
bb4cc1a8 | 781 | mz = __mem_cgroup_largest_soft_limit_node(mctz); |
0a31bc97 | 782 | spin_unlock_irq(&mctz->lock); |
bb4cc1a8 AM |
783 | return mz; |
784 | } | |
785 | ||
711d3d2c KH |
786 | /* |
787 | * Implementation Note: reading percpu statistics for memcg. | |
788 | * | |
789 | * Both of vmstat[] and percpu_counter has threshold and do periodic | |
790 | * synchronization to implement "quick" read. There are trade-off between | |
791 | * reading cost and precision of value. Then, we may have a chance to implement | |
792 | * a periodic synchronizion of counter in memcg's counter. | |
793 | * | |
794 | * But this _read() function is used for user interface now. The user accounts | |
795 | * memory usage by memory cgroup and he _always_ requires exact value because | |
796 | * he accounts memory. Even if we provide quick-and-fuzzy read, we always | |
797 | * have to visit all online cpus and make sum. So, for now, unnecessary | |
798 | * synchronization is not implemented. (just implemented for cpu hotplug) | |
799 | * | |
800 | * If there are kernel internal actions which can make use of some not-exact | |
801 | * value, and reading all cpu value can be performance bottleneck in some | |
802 | * common workload, threashold and synchonization as vmstat[] should be | |
803 | * implemented. | |
804 | */ | |
c0ff4b85 | 805 | static long mem_cgroup_read_stat(struct mem_cgroup *memcg, |
7a159cc9 | 806 | enum mem_cgroup_stat_index idx) |
c62b1a3b | 807 | { |
7a159cc9 | 808 | long val = 0; |
c62b1a3b | 809 | int cpu; |
c62b1a3b | 810 | |
711d3d2c KH |
811 | get_online_cpus(); |
812 | for_each_online_cpu(cpu) | |
c0ff4b85 | 813 | val += per_cpu(memcg->stat->count[idx], cpu); |
711d3d2c | 814 | #ifdef CONFIG_HOTPLUG_CPU |
c0ff4b85 R |
815 | spin_lock(&memcg->pcp_counter_lock); |
816 | val += memcg->nocpu_base.count[idx]; | |
817 | spin_unlock(&memcg->pcp_counter_lock); | |
711d3d2c KH |
818 | #endif |
819 | put_online_cpus(); | |
c62b1a3b KH |
820 | return val; |
821 | } | |
822 | ||
c0ff4b85 | 823 | static unsigned long mem_cgroup_read_events(struct mem_cgroup *memcg, |
e9f8974f JW |
824 | enum mem_cgroup_events_index idx) |
825 | { | |
826 | unsigned long val = 0; | |
827 | int cpu; | |
828 | ||
9c567512 | 829 | get_online_cpus(); |
e9f8974f | 830 | for_each_online_cpu(cpu) |
c0ff4b85 | 831 | val += per_cpu(memcg->stat->events[idx], cpu); |
e9f8974f | 832 | #ifdef CONFIG_HOTPLUG_CPU |
c0ff4b85 R |
833 | spin_lock(&memcg->pcp_counter_lock); |
834 | val += memcg->nocpu_base.events[idx]; | |
835 | spin_unlock(&memcg->pcp_counter_lock); | |
e9f8974f | 836 | #endif |
9c567512 | 837 | put_online_cpus(); |
e9f8974f JW |
838 | return val; |
839 | } | |
840 | ||
c0ff4b85 | 841 | static void mem_cgroup_charge_statistics(struct mem_cgroup *memcg, |
b070e65c | 842 | struct page *page, |
0a31bc97 | 843 | int nr_pages) |
d52aa412 | 844 | { |
b2402857 KH |
845 | /* |
846 | * Here, RSS means 'mapped anon' and anon's SwapCache. Shmem/tmpfs is | |
847 | * counted as CACHE even if it's on ANON LRU. | |
848 | */ | |
0a31bc97 | 849 | if (PageAnon(page)) |
b2402857 | 850 | __this_cpu_add(memcg->stat->count[MEM_CGROUP_STAT_RSS], |
c0ff4b85 | 851 | nr_pages); |
d52aa412 | 852 | else |
b2402857 | 853 | __this_cpu_add(memcg->stat->count[MEM_CGROUP_STAT_CACHE], |
c0ff4b85 | 854 | nr_pages); |
55e462b0 | 855 | |
b070e65c DR |
856 | if (PageTransHuge(page)) |
857 | __this_cpu_add(memcg->stat->count[MEM_CGROUP_STAT_RSS_HUGE], | |
858 | nr_pages); | |
859 | ||
e401f176 KH |
860 | /* pagein of a big page is an event. So, ignore page size */ |
861 | if (nr_pages > 0) | |
c0ff4b85 | 862 | __this_cpu_inc(memcg->stat->events[MEM_CGROUP_EVENTS_PGPGIN]); |
3751d604 | 863 | else { |
c0ff4b85 | 864 | __this_cpu_inc(memcg->stat->events[MEM_CGROUP_EVENTS_PGPGOUT]); |
3751d604 KH |
865 | nr_pages = -nr_pages; /* for event */ |
866 | } | |
e401f176 | 867 | |
13114716 | 868 | __this_cpu_add(memcg->stat->nr_page_events, nr_pages); |
6d12e2d8 KH |
869 | } |
870 | ||
e231875b | 871 | unsigned long mem_cgroup_get_lru_size(struct lruvec *lruvec, enum lru_list lru) |
074291fe KK |
872 | { |
873 | struct mem_cgroup_per_zone *mz; | |
874 | ||
875 | mz = container_of(lruvec, struct mem_cgroup_per_zone, lruvec); | |
876 | return mz->lru_size[lru]; | |
877 | } | |
878 | ||
e231875b JZ |
879 | static unsigned long mem_cgroup_node_nr_lru_pages(struct mem_cgroup *memcg, |
880 | int nid, | |
881 | unsigned int lru_mask) | |
bb2a0de9 | 882 | { |
e231875b | 883 | unsigned long nr = 0; |
889976db YH |
884 | int zid; |
885 | ||
e231875b | 886 | VM_BUG_ON((unsigned)nid >= nr_node_ids); |
bb2a0de9 | 887 | |
e231875b JZ |
888 | for (zid = 0; zid < MAX_NR_ZONES; zid++) { |
889 | struct mem_cgroup_per_zone *mz; | |
890 | enum lru_list lru; | |
891 | ||
892 | for_each_lru(lru) { | |
893 | if (!(BIT(lru) & lru_mask)) | |
894 | continue; | |
895 | mz = &memcg->nodeinfo[nid]->zoneinfo[zid]; | |
896 | nr += mz->lru_size[lru]; | |
897 | } | |
898 | } | |
899 | return nr; | |
889976db | 900 | } |
bb2a0de9 | 901 | |
c0ff4b85 | 902 | static unsigned long mem_cgroup_nr_lru_pages(struct mem_cgroup *memcg, |
bb2a0de9 | 903 | unsigned int lru_mask) |
6d12e2d8 | 904 | { |
e231875b | 905 | unsigned long nr = 0; |
889976db | 906 | int nid; |
6d12e2d8 | 907 | |
31aaea4a | 908 | for_each_node_state(nid, N_MEMORY) |
e231875b JZ |
909 | nr += mem_cgroup_node_nr_lru_pages(memcg, nid, lru_mask); |
910 | return nr; | |
d52aa412 KH |
911 | } |
912 | ||
f53d7ce3 JW |
913 | static bool mem_cgroup_event_ratelimit(struct mem_cgroup *memcg, |
914 | enum mem_cgroup_events_target target) | |
7a159cc9 JW |
915 | { |
916 | unsigned long val, next; | |
917 | ||
13114716 | 918 | val = __this_cpu_read(memcg->stat->nr_page_events); |
4799401f | 919 | next = __this_cpu_read(memcg->stat->targets[target]); |
7a159cc9 | 920 | /* from time_after() in jiffies.h */ |
f53d7ce3 JW |
921 | if ((long)next - (long)val < 0) { |
922 | switch (target) { | |
923 | case MEM_CGROUP_TARGET_THRESH: | |
924 | next = val + THRESHOLDS_EVENTS_TARGET; | |
925 | break; | |
bb4cc1a8 AM |
926 | case MEM_CGROUP_TARGET_SOFTLIMIT: |
927 | next = val + SOFTLIMIT_EVENTS_TARGET; | |
928 | break; | |
f53d7ce3 JW |
929 | case MEM_CGROUP_TARGET_NUMAINFO: |
930 | next = val + NUMAINFO_EVENTS_TARGET; | |
931 | break; | |
932 | default: | |
933 | break; | |
934 | } | |
935 | __this_cpu_write(memcg->stat->targets[target], next); | |
936 | return true; | |
7a159cc9 | 937 | } |
f53d7ce3 | 938 | return false; |
d2265e6f KH |
939 | } |
940 | ||
941 | /* | |
942 | * Check events in order. | |
943 | * | |
944 | */ | |
c0ff4b85 | 945 | static void memcg_check_events(struct mem_cgroup *memcg, struct page *page) |
d2265e6f KH |
946 | { |
947 | /* threshold event is triggered in finer grain than soft limit */ | |
f53d7ce3 JW |
948 | if (unlikely(mem_cgroup_event_ratelimit(memcg, |
949 | MEM_CGROUP_TARGET_THRESH))) { | |
bb4cc1a8 | 950 | bool do_softlimit; |
82b3f2a7 | 951 | bool do_numainfo __maybe_unused; |
f53d7ce3 | 952 | |
bb4cc1a8 AM |
953 | do_softlimit = mem_cgroup_event_ratelimit(memcg, |
954 | MEM_CGROUP_TARGET_SOFTLIMIT); | |
f53d7ce3 JW |
955 | #if MAX_NUMNODES > 1 |
956 | do_numainfo = mem_cgroup_event_ratelimit(memcg, | |
957 | MEM_CGROUP_TARGET_NUMAINFO); | |
958 | #endif | |
c0ff4b85 | 959 | mem_cgroup_threshold(memcg); |
bb4cc1a8 AM |
960 | if (unlikely(do_softlimit)) |
961 | mem_cgroup_update_tree(memcg, page); | |
453a9bf3 | 962 | #if MAX_NUMNODES > 1 |
f53d7ce3 | 963 | if (unlikely(do_numainfo)) |
c0ff4b85 | 964 | atomic_inc(&memcg->numainfo_events); |
453a9bf3 | 965 | #endif |
0a31bc97 | 966 | } |
d2265e6f KH |
967 | } |
968 | ||
cf475ad2 | 969 | struct mem_cgroup *mem_cgroup_from_task(struct task_struct *p) |
78fb7466 | 970 | { |
31a78f23 BS |
971 | /* |
972 | * mm_update_next_owner() may clear mm->owner to NULL | |
973 | * if it races with swapoff, page migration, etc. | |
974 | * So this can be called with p == NULL. | |
975 | */ | |
976 | if (unlikely(!p)) | |
977 | return NULL; | |
978 | ||
073219e9 | 979 | return mem_cgroup_from_css(task_css(p, memory_cgrp_id)); |
78fb7466 PE |
980 | } |
981 | ||
df381975 | 982 | static struct mem_cgroup *get_mem_cgroup_from_mm(struct mm_struct *mm) |
54595fe2 | 983 | { |
c0ff4b85 | 984 | struct mem_cgroup *memcg = NULL; |
0b7f569e | 985 | |
54595fe2 KH |
986 | rcu_read_lock(); |
987 | do { | |
6f6acb00 MH |
988 | /* |
989 | * Page cache insertions can happen withou an | |
990 | * actual mm context, e.g. during disk probing | |
991 | * on boot, loopback IO, acct() writes etc. | |
992 | */ | |
993 | if (unlikely(!mm)) | |
df381975 | 994 | memcg = root_mem_cgroup; |
6f6acb00 MH |
995 | else { |
996 | memcg = mem_cgroup_from_task(rcu_dereference(mm->owner)); | |
997 | if (unlikely(!memcg)) | |
998 | memcg = root_mem_cgroup; | |
999 | } | |
ec903c0c | 1000 | } while (!css_tryget_online(&memcg->css)); |
54595fe2 | 1001 | rcu_read_unlock(); |
c0ff4b85 | 1002 | return memcg; |
54595fe2 KH |
1003 | } |
1004 | ||
5660048c JW |
1005 | /** |
1006 | * mem_cgroup_iter - iterate over memory cgroup hierarchy | |
1007 | * @root: hierarchy root | |
1008 | * @prev: previously returned memcg, NULL on first invocation | |
1009 | * @reclaim: cookie for shared reclaim walks, NULL for full walks | |
1010 | * | |
1011 | * Returns references to children of the hierarchy below @root, or | |
1012 | * @root itself, or %NULL after a full round-trip. | |
1013 | * | |
1014 | * Caller must pass the return value in @prev on subsequent | |
1015 | * invocations for reference counting, or use mem_cgroup_iter_break() | |
1016 | * to cancel a hierarchy walk before the round-trip is complete. | |
1017 | * | |
1018 | * Reclaimers can specify a zone and a priority level in @reclaim to | |
1019 | * divide up the memcgs in the hierarchy among all concurrent | |
1020 | * reclaimers operating on the same zone and priority. | |
1021 | */ | |
694fbc0f | 1022 | struct mem_cgroup *mem_cgroup_iter(struct mem_cgroup *root, |
5660048c | 1023 | struct mem_cgroup *prev, |
694fbc0f | 1024 | struct mem_cgroup_reclaim_cookie *reclaim) |
14067bb3 | 1025 | { |
5ac8fb31 JW |
1026 | struct reclaim_iter *uninitialized_var(iter); |
1027 | struct cgroup_subsys_state *css = NULL; | |
9f3a0d09 | 1028 | struct mem_cgroup *memcg = NULL; |
5ac8fb31 | 1029 | struct mem_cgroup *pos = NULL; |
711d3d2c | 1030 | |
694fbc0f AM |
1031 | if (mem_cgroup_disabled()) |
1032 | return NULL; | |
5660048c | 1033 | |
9f3a0d09 JW |
1034 | if (!root) |
1035 | root = root_mem_cgroup; | |
7d74b06f | 1036 | |
9f3a0d09 | 1037 | if (prev && !reclaim) |
5ac8fb31 | 1038 | pos = prev; |
14067bb3 | 1039 | |
9f3a0d09 JW |
1040 | if (!root->use_hierarchy && root != root_mem_cgroup) { |
1041 | if (prev) | |
5ac8fb31 | 1042 | goto out; |
694fbc0f | 1043 | return root; |
9f3a0d09 | 1044 | } |
14067bb3 | 1045 | |
542f85f9 | 1046 | rcu_read_lock(); |
5f578161 | 1047 | |
5ac8fb31 JW |
1048 | if (reclaim) { |
1049 | struct mem_cgroup_per_zone *mz; | |
1050 | ||
1051 | mz = mem_cgroup_zone_zoneinfo(root, reclaim->zone); | |
1052 | iter = &mz->iter[reclaim->priority]; | |
1053 | ||
1054 | if (prev && reclaim->generation != iter->generation) | |
1055 | goto out_unlock; | |
1056 | ||
1057 | do { | |
1058 | pos = ACCESS_ONCE(iter->position); | |
1059 | /* | |
1060 | * A racing update may change the position and | |
1061 | * put the last reference, hence css_tryget(), | |
1062 | * or retry to see the updated position. | |
1063 | */ | |
1064 | } while (pos && !css_tryget(&pos->css)); | |
1065 | } | |
1066 | ||
1067 | if (pos) | |
1068 | css = &pos->css; | |
1069 | ||
1070 | for (;;) { | |
1071 | css = css_next_descendant_pre(css, &root->css); | |
1072 | if (!css) { | |
1073 | /* | |
1074 | * Reclaimers share the hierarchy walk, and a | |
1075 | * new one might jump in right at the end of | |
1076 | * the hierarchy - make sure they see at least | |
1077 | * one group and restart from the beginning. | |
1078 | */ | |
1079 | if (!prev) | |
1080 | continue; | |
1081 | break; | |
527a5ec9 | 1082 | } |
7d74b06f | 1083 | |
5ac8fb31 JW |
1084 | /* |
1085 | * Verify the css and acquire a reference. The root | |
1086 | * is provided by the caller, so we know it's alive | |
1087 | * and kicking, and don't take an extra reference. | |
1088 | */ | |
1089 | memcg = mem_cgroup_from_css(css); | |
14067bb3 | 1090 | |
5ac8fb31 JW |
1091 | if (css == &root->css) |
1092 | break; | |
14067bb3 | 1093 | |
b2052564 | 1094 | if (css_tryget(css)) { |
5ac8fb31 JW |
1095 | /* |
1096 | * Make sure the memcg is initialized: | |
1097 | * mem_cgroup_css_online() orders the the | |
1098 | * initialization against setting the flag. | |
1099 | */ | |
1100 | if (smp_load_acquire(&memcg->initialized)) | |
1101 | break; | |
542f85f9 | 1102 | |
5ac8fb31 | 1103 | css_put(css); |
527a5ec9 | 1104 | } |
9f3a0d09 | 1105 | |
5ac8fb31 | 1106 | memcg = NULL; |
9f3a0d09 | 1107 | } |
5ac8fb31 JW |
1108 | |
1109 | if (reclaim) { | |
1110 | if (cmpxchg(&iter->position, pos, memcg) == pos) { | |
1111 | if (memcg) | |
1112 | css_get(&memcg->css); | |
1113 | if (pos) | |
1114 | css_put(&pos->css); | |
1115 | } | |
1116 | ||
1117 | /* | |
1118 | * pairs with css_tryget when dereferencing iter->position | |
1119 | * above. | |
1120 | */ | |
1121 | if (pos) | |
1122 | css_put(&pos->css); | |
1123 | ||
1124 | if (!memcg) | |
1125 | iter->generation++; | |
1126 | else if (!prev) | |
1127 | reclaim->generation = iter->generation; | |
9f3a0d09 | 1128 | } |
5ac8fb31 | 1129 | |
542f85f9 MH |
1130 | out_unlock: |
1131 | rcu_read_unlock(); | |
5ac8fb31 | 1132 | out: |
c40046f3 MH |
1133 | if (prev && prev != root) |
1134 | css_put(&prev->css); | |
1135 | ||
9f3a0d09 | 1136 | return memcg; |
14067bb3 | 1137 | } |
7d74b06f | 1138 | |
5660048c JW |
1139 | /** |
1140 | * mem_cgroup_iter_break - abort a hierarchy walk prematurely | |
1141 | * @root: hierarchy root | |
1142 | * @prev: last visited hierarchy member as returned by mem_cgroup_iter() | |
1143 | */ | |
1144 | void mem_cgroup_iter_break(struct mem_cgroup *root, | |
1145 | struct mem_cgroup *prev) | |
9f3a0d09 JW |
1146 | { |
1147 | if (!root) | |
1148 | root = root_mem_cgroup; | |
1149 | if (prev && prev != root) | |
1150 | css_put(&prev->css); | |
1151 | } | |
7d74b06f | 1152 | |
9f3a0d09 JW |
1153 | /* |
1154 | * Iteration constructs for visiting all cgroups (under a tree). If | |
1155 | * loops are exited prematurely (break), mem_cgroup_iter_break() must | |
1156 | * be used for reference counting. | |
1157 | */ | |
1158 | #define for_each_mem_cgroup_tree(iter, root) \ | |
527a5ec9 | 1159 | for (iter = mem_cgroup_iter(root, NULL, NULL); \ |
9f3a0d09 | 1160 | iter != NULL; \ |
527a5ec9 | 1161 | iter = mem_cgroup_iter(root, iter, NULL)) |
711d3d2c | 1162 | |
9f3a0d09 | 1163 | #define for_each_mem_cgroup(iter) \ |
527a5ec9 | 1164 | for (iter = mem_cgroup_iter(NULL, NULL, NULL); \ |
9f3a0d09 | 1165 | iter != NULL; \ |
527a5ec9 | 1166 | iter = mem_cgroup_iter(NULL, iter, NULL)) |
14067bb3 | 1167 | |
68ae564b | 1168 | void __mem_cgroup_count_vm_event(struct mm_struct *mm, enum vm_event_item idx) |
456f998e | 1169 | { |
c0ff4b85 | 1170 | struct mem_cgroup *memcg; |
456f998e | 1171 | |
456f998e | 1172 | rcu_read_lock(); |
c0ff4b85 R |
1173 | memcg = mem_cgroup_from_task(rcu_dereference(mm->owner)); |
1174 | if (unlikely(!memcg)) | |
456f998e YH |
1175 | goto out; |
1176 | ||
1177 | switch (idx) { | |
456f998e | 1178 | case PGFAULT: |
0e574a93 JW |
1179 | this_cpu_inc(memcg->stat->events[MEM_CGROUP_EVENTS_PGFAULT]); |
1180 | break; | |
1181 | case PGMAJFAULT: | |
1182 | this_cpu_inc(memcg->stat->events[MEM_CGROUP_EVENTS_PGMAJFAULT]); | |
456f998e YH |
1183 | break; |
1184 | default: | |
1185 | BUG(); | |
1186 | } | |
1187 | out: | |
1188 | rcu_read_unlock(); | |
1189 | } | |
68ae564b | 1190 | EXPORT_SYMBOL(__mem_cgroup_count_vm_event); |
456f998e | 1191 | |
925b7673 JW |
1192 | /** |
1193 | * mem_cgroup_zone_lruvec - get the lru list vector for a zone and memcg | |
1194 | * @zone: zone of the wanted lruvec | |
fa9add64 | 1195 | * @memcg: memcg of the wanted lruvec |
925b7673 JW |
1196 | * |
1197 | * Returns the lru list vector holding pages for the given @zone and | |
1198 | * @mem. This can be the global zone lruvec, if the memory controller | |
1199 | * is disabled. | |
1200 | */ | |
1201 | struct lruvec *mem_cgroup_zone_lruvec(struct zone *zone, | |
1202 | struct mem_cgroup *memcg) | |
1203 | { | |
1204 | struct mem_cgroup_per_zone *mz; | |
bea8c150 | 1205 | struct lruvec *lruvec; |
925b7673 | 1206 | |
bea8c150 HD |
1207 | if (mem_cgroup_disabled()) { |
1208 | lruvec = &zone->lruvec; | |
1209 | goto out; | |
1210 | } | |
925b7673 | 1211 | |
e231875b | 1212 | mz = mem_cgroup_zone_zoneinfo(memcg, zone); |
bea8c150 HD |
1213 | lruvec = &mz->lruvec; |
1214 | out: | |
1215 | /* | |
1216 | * Since a node can be onlined after the mem_cgroup was created, | |
1217 | * we have to be prepared to initialize lruvec->zone here; | |
1218 | * and if offlined then reonlined, we need to reinitialize it. | |
1219 | */ | |
1220 | if (unlikely(lruvec->zone != zone)) | |
1221 | lruvec->zone = zone; | |
1222 | return lruvec; | |
925b7673 JW |
1223 | } |
1224 | ||
925b7673 | 1225 | /** |
dfe0e773 | 1226 | * mem_cgroup_page_lruvec - return lruvec for isolating/putting an LRU page |
925b7673 | 1227 | * @page: the page |
fa9add64 | 1228 | * @zone: zone of the page |
dfe0e773 JW |
1229 | * |
1230 | * This function is only safe when following the LRU page isolation | |
1231 | * and putback protocol: the LRU lock must be held, and the page must | |
1232 | * either be PageLRU() or the caller must have isolated/allocated it. | |
925b7673 | 1233 | */ |
fa9add64 | 1234 | struct lruvec *mem_cgroup_page_lruvec(struct page *page, struct zone *zone) |
08e552c6 | 1235 | { |
08e552c6 | 1236 | struct mem_cgroup_per_zone *mz; |
925b7673 | 1237 | struct mem_cgroup *memcg; |
bea8c150 | 1238 | struct lruvec *lruvec; |
6d12e2d8 | 1239 | |
bea8c150 HD |
1240 | if (mem_cgroup_disabled()) { |
1241 | lruvec = &zone->lruvec; | |
1242 | goto out; | |
1243 | } | |
925b7673 | 1244 | |
1306a85a | 1245 | memcg = page->mem_cgroup; |
7512102c | 1246 | /* |
dfe0e773 | 1247 | * Swapcache readahead pages are added to the LRU - and |
29833315 | 1248 | * possibly migrated - before they are charged. |
7512102c | 1249 | */ |
29833315 JW |
1250 | if (!memcg) |
1251 | memcg = root_mem_cgroup; | |
7512102c | 1252 | |
e231875b | 1253 | mz = mem_cgroup_page_zoneinfo(memcg, page); |
bea8c150 HD |
1254 | lruvec = &mz->lruvec; |
1255 | out: | |
1256 | /* | |
1257 | * Since a node can be onlined after the mem_cgroup was created, | |
1258 | * we have to be prepared to initialize lruvec->zone here; | |
1259 | * and if offlined then reonlined, we need to reinitialize it. | |
1260 | */ | |
1261 | if (unlikely(lruvec->zone != zone)) | |
1262 | lruvec->zone = zone; | |
1263 | return lruvec; | |
08e552c6 | 1264 | } |
b69408e8 | 1265 | |
925b7673 | 1266 | /** |
fa9add64 HD |
1267 | * mem_cgroup_update_lru_size - account for adding or removing an lru page |
1268 | * @lruvec: mem_cgroup per zone lru vector | |
1269 | * @lru: index of lru list the page is sitting on | |
1270 | * @nr_pages: positive when adding or negative when removing | |
925b7673 | 1271 | * |
fa9add64 HD |
1272 | * This function must be called when a page is added to or removed from an |
1273 | * lru list. | |
3f58a829 | 1274 | */ |
fa9add64 HD |
1275 | void mem_cgroup_update_lru_size(struct lruvec *lruvec, enum lru_list lru, |
1276 | int nr_pages) | |
3f58a829 MK |
1277 | { |
1278 | struct mem_cgroup_per_zone *mz; | |
fa9add64 | 1279 | unsigned long *lru_size; |
3f58a829 MK |
1280 | |
1281 | if (mem_cgroup_disabled()) | |
1282 | return; | |
1283 | ||
fa9add64 HD |
1284 | mz = container_of(lruvec, struct mem_cgroup_per_zone, lruvec); |
1285 | lru_size = mz->lru_size + lru; | |
1286 | *lru_size += nr_pages; | |
1287 | VM_BUG_ON((long)(*lru_size) < 0); | |
08e552c6 | 1288 | } |
544122e5 | 1289 | |
2314b42d | 1290 | bool mem_cgroup_is_descendant(struct mem_cgroup *memcg, struct mem_cgroup *root) |
3e92041d | 1291 | { |
2314b42d | 1292 | if (root == memcg) |
91c63734 | 1293 | return true; |
2314b42d | 1294 | if (!root->use_hierarchy) |
91c63734 | 1295 | return false; |
2314b42d | 1296 | return cgroup_is_descendant(memcg->css.cgroup, root->css.cgroup); |
c3ac9a8a JW |
1297 | } |
1298 | ||
2314b42d | 1299 | bool task_in_mem_cgroup(struct task_struct *task, struct mem_cgroup *memcg) |
c3ac9a8a | 1300 | { |
2314b42d | 1301 | struct mem_cgroup *task_memcg; |
158e0a2d | 1302 | struct task_struct *p; |
ffbdccf5 | 1303 | bool ret; |
4c4a2214 | 1304 | |
158e0a2d | 1305 | p = find_lock_task_mm(task); |
de077d22 | 1306 | if (p) { |
2314b42d | 1307 | task_memcg = get_mem_cgroup_from_mm(p->mm); |
de077d22 DR |
1308 | task_unlock(p); |
1309 | } else { | |
1310 | /* | |
1311 | * All threads may have already detached their mm's, but the oom | |
1312 | * killer still needs to detect if they have already been oom | |
1313 | * killed to prevent needlessly killing additional tasks. | |
1314 | */ | |
ffbdccf5 | 1315 | rcu_read_lock(); |
2314b42d JW |
1316 | task_memcg = mem_cgroup_from_task(task); |
1317 | css_get(&task_memcg->css); | |
ffbdccf5 | 1318 | rcu_read_unlock(); |
de077d22 | 1319 | } |
2314b42d JW |
1320 | ret = mem_cgroup_is_descendant(task_memcg, memcg); |
1321 | css_put(&task_memcg->css); | |
4c4a2214 DR |
1322 | return ret; |
1323 | } | |
1324 | ||
c56d5c7d | 1325 | int mem_cgroup_inactive_anon_is_low(struct lruvec *lruvec) |
14797e23 | 1326 | { |
9b272977 | 1327 | unsigned long inactive_ratio; |
14797e23 | 1328 | unsigned long inactive; |
9b272977 | 1329 | unsigned long active; |
c772be93 | 1330 | unsigned long gb; |
14797e23 | 1331 | |
4d7dcca2 HD |
1332 | inactive = mem_cgroup_get_lru_size(lruvec, LRU_INACTIVE_ANON); |
1333 | active = mem_cgroup_get_lru_size(lruvec, LRU_ACTIVE_ANON); | |
14797e23 | 1334 | |
c772be93 KM |
1335 | gb = (inactive + active) >> (30 - PAGE_SHIFT); |
1336 | if (gb) | |
1337 | inactive_ratio = int_sqrt(10 * gb); | |
1338 | else | |
1339 | inactive_ratio = 1; | |
1340 | ||
9b272977 | 1341 | return inactive * inactive_ratio < active; |
14797e23 KM |
1342 | } |
1343 | ||
90cbc250 VD |
1344 | bool mem_cgroup_lruvec_online(struct lruvec *lruvec) |
1345 | { | |
1346 | struct mem_cgroup_per_zone *mz; | |
1347 | struct mem_cgroup *memcg; | |
1348 | ||
1349 | if (mem_cgroup_disabled()) | |
1350 | return true; | |
1351 | ||
1352 | mz = container_of(lruvec, struct mem_cgroup_per_zone, lruvec); | |
1353 | memcg = mz->memcg; | |
1354 | ||
1355 | return !!(memcg->css.flags & CSS_ONLINE); | |
1356 | } | |
1357 | ||
3e32cb2e | 1358 | #define mem_cgroup_from_counter(counter, member) \ |
6d61ef40 BS |
1359 | container_of(counter, struct mem_cgroup, member) |
1360 | ||
19942822 | 1361 | /** |
9d11ea9f | 1362 | * mem_cgroup_margin - calculate chargeable space of a memory cgroup |
dad7557e | 1363 | * @memcg: the memory cgroup |
19942822 | 1364 | * |
9d11ea9f | 1365 | * Returns the maximum amount of memory @mem can be charged with, in |
7ec99d62 | 1366 | * pages. |
19942822 | 1367 | */ |
c0ff4b85 | 1368 | static unsigned long mem_cgroup_margin(struct mem_cgroup *memcg) |
19942822 | 1369 | { |
3e32cb2e JW |
1370 | unsigned long margin = 0; |
1371 | unsigned long count; | |
1372 | unsigned long limit; | |
9d11ea9f | 1373 | |
3e32cb2e JW |
1374 | count = page_counter_read(&memcg->memory); |
1375 | limit = ACCESS_ONCE(memcg->memory.limit); | |
1376 | if (count < limit) | |
1377 | margin = limit - count; | |
1378 | ||
1379 | if (do_swap_account) { | |
1380 | count = page_counter_read(&memcg->memsw); | |
1381 | limit = ACCESS_ONCE(memcg->memsw.limit); | |
1382 | if (count <= limit) | |
1383 | margin = min(margin, limit - count); | |
1384 | } | |
1385 | ||
1386 | return margin; | |
19942822 JW |
1387 | } |
1388 | ||
1f4c025b | 1389 | int mem_cgroup_swappiness(struct mem_cgroup *memcg) |
a7885eb8 | 1390 | { |
a7885eb8 | 1391 | /* root ? */ |
14208b0e | 1392 | if (mem_cgroup_disabled() || !memcg->css.parent) |
a7885eb8 KM |
1393 | return vm_swappiness; |
1394 | ||
bf1ff263 | 1395 | return memcg->swappiness; |
a7885eb8 KM |
1396 | } |
1397 | ||
32047e2a | 1398 | /* |
bdcbb659 | 1399 | * A routine for checking "mem" is under move_account() or not. |
32047e2a | 1400 | * |
bdcbb659 QH |
1401 | * Checking a cgroup is mc.from or mc.to or under hierarchy of |
1402 | * moving cgroups. This is for waiting at high-memory pressure | |
1403 | * caused by "move". | |
32047e2a | 1404 | */ |
c0ff4b85 | 1405 | static bool mem_cgroup_under_move(struct mem_cgroup *memcg) |
4b534334 | 1406 | { |
2bd9bb20 KH |
1407 | struct mem_cgroup *from; |
1408 | struct mem_cgroup *to; | |
4b534334 | 1409 | bool ret = false; |
2bd9bb20 KH |
1410 | /* |
1411 | * Unlike task_move routines, we access mc.to, mc.from not under | |
1412 | * mutual exclusion by cgroup_mutex. Here, we take spinlock instead. | |
1413 | */ | |
1414 | spin_lock(&mc.lock); | |
1415 | from = mc.from; | |
1416 | to = mc.to; | |
1417 | if (!from) | |
1418 | goto unlock; | |
3e92041d | 1419 | |
2314b42d JW |
1420 | ret = mem_cgroup_is_descendant(from, memcg) || |
1421 | mem_cgroup_is_descendant(to, memcg); | |
2bd9bb20 KH |
1422 | unlock: |
1423 | spin_unlock(&mc.lock); | |
4b534334 KH |
1424 | return ret; |
1425 | } | |
1426 | ||
c0ff4b85 | 1427 | static bool mem_cgroup_wait_acct_move(struct mem_cgroup *memcg) |
4b534334 KH |
1428 | { |
1429 | if (mc.moving_task && current != mc.moving_task) { | |
c0ff4b85 | 1430 | if (mem_cgroup_under_move(memcg)) { |
4b534334 KH |
1431 | DEFINE_WAIT(wait); |
1432 | prepare_to_wait(&mc.waitq, &wait, TASK_INTERRUPTIBLE); | |
1433 | /* moving charge context might have finished. */ | |
1434 | if (mc.moving_task) | |
1435 | schedule(); | |
1436 | finish_wait(&mc.waitq, &wait); | |
1437 | return true; | |
1438 | } | |
1439 | } | |
1440 | return false; | |
1441 | } | |
1442 | ||
58cf188e | 1443 | #define K(x) ((x) << (PAGE_SHIFT-10)) |
e222432b | 1444 | /** |
58cf188e | 1445 | * mem_cgroup_print_oom_info: Print OOM information relevant to memory controller. |
e222432b BS |
1446 | * @memcg: The memory cgroup that went over limit |
1447 | * @p: Task that is going to be killed | |
1448 | * | |
1449 | * NOTE: @memcg and @p's mem_cgroup can be different when hierarchy is | |
1450 | * enabled | |
1451 | */ | |
1452 | void mem_cgroup_print_oom_info(struct mem_cgroup *memcg, struct task_struct *p) | |
1453 | { | |
e61734c5 | 1454 | /* oom_info_lock ensures that parallel ooms do not interleave */ |
08088cb9 | 1455 | static DEFINE_MUTEX(oom_info_lock); |
58cf188e SZ |
1456 | struct mem_cgroup *iter; |
1457 | unsigned int i; | |
e222432b | 1458 | |
58cf188e | 1459 | if (!p) |
e222432b BS |
1460 | return; |
1461 | ||
08088cb9 | 1462 | mutex_lock(&oom_info_lock); |
e222432b BS |
1463 | rcu_read_lock(); |
1464 | ||
e61734c5 TH |
1465 | pr_info("Task in "); |
1466 | pr_cont_cgroup_path(task_cgroup(p, memory_cgrp_id)); | |
0346dadb | 1467 | pr_cont(" killed as a result of limit of "); |
e61734c5 | 1468 | pr_cont_cgroup_path(memcg->css.cgroup); |
0346dadb | 1469 | pr_cont("\n"); |
e222432b | 1470 | |
e222432b BS |
1471 | rcu_read_unlock(); |
1472 | ||
3e32cb2e JW |
1473 | pr_info("memory: usage %llukB, limit %llukB, failcnt %lu\n", |
1474 | K((u64)page_counter_read(&memcg->memory)), | |
1475 | K((u64)memcg->memory.limit), memcg->memory.failcnt); | |
1476 | pr_info("memory+swap: usage %llukB, limit %llukB, failcnt %lu\n", | |
1477 | K((u64)page_counter_read(&memcg->memsw)), | |
1478 | K((u64)memcg->memsw.limit), memcg->memsw.failcnt); | |
1479 | pr_info("kmem: usage %llukB, limit %llukB, failcnt %lu\n", | |
1480 | K((u64)page_counter_read(&memcg->kmem)), | |
1481 | K((u64)memcg->kmem.limit), memcg->kmem.failcnt); | |
58cf188e SZ |
1482 | |
1483 | for_each_mem_cgroup_tree(iter, memcg) { | |
e61734c5 TH |
1484 | pr_info("Memory cgroup stats for "); |
1485 | pr_cont_cgroup_path(iter->css.cgroup); | |
58cf188e SZ |
1486 | pr_cont(":"); |
1487 | ||
1488 | for (i = 0; i < MEM_CGROUP_STAT_NSTATS; i++) { | |
1489 | if (i == MEM_CGROUP_STAT_SWAP && !do_swap_account) | |
1490 | continue; | |
1491 | pr_cont(" %s:%ldKB", mem_cgroup_stat_names[i], | |
1492 | K(mem_cgroup_read_stat(iter, i))); | |
1493 | } | |
1494 | ||
1495 | for (i = 0; i < NR_LRU_LISTS; i++) | |
1496 | pr_cont(" %s:%luKB", mem_cgroup_lru_names[i], | |
1497 | K(mem_cgroup_nr_lru_pages(iter, BIT(i)))); | |
1498 | ||
1499 | pr_cont("\n"); | |
1500 | } | |
08088cb9 | 1501 | mutex_unlock(&oom_info_lock); |
e222432b BS |
1502 | } |
1503 | ||
81d39c20 KH |
1504 | /* |
1505 | * This function returns the number of memcg under hierarchy tree. Returns | |
1506 | * 1(self count) if no children. | |
1507 | */ | |
c0ff4b85 | 1508 | static int mem_cgroup_count_children(struct mem_cgroup *memcg) |
81d39c20 KH |
1509 | { |
1510 | int num = 0; | |
7d74b06f KH |
1511 | struct mem_cgroup *iter; |
1512 | ||
c0ff4b85 | 1513 | for_each_mem_cgroup_tree(iter, memcg) |
7d74b06f | 1514 | num++; |
81d39c20 KH |
1515 | return num; |
1516 | } | |
1517 | ||
a63d83f4 DR |
1518 | /* |
1519 | * Return the memory (and swap, if configured) limit for a memcg. | |
1520 | */ | |
3e32cb2e | 1521 | static unsigned long mem_cgroup_get_limit(struct mem_cgroup *memcg) |
a63d83f4 | 1522 | { |
3e32cb2e | 1523 | unsigned long limit; |
f3e8eb70 | 1524 | |
3e32cb2e | 1525 | limit = memcg->memory.limit; |
9a5a8f19 | 1526 | if (mem_cgroup_swappiness(memcg)) { |
3e32cb2e | 1527 | unsigned long memsw_limit; |
9a5a8f19 | 1528 | |
3e32cb2e JW |
1529 | memsw_limit = memcg->memsw.limit; |
1530 | limit = min(limit + total_swap_pages, memsw_limit); | |
9a5a8f19 | 1531 | } |
9a5a8f19 | 1532 | return limit; |
a63d83f4 DR |
1533 | } |
1534 | ||
19965460 DR |
1535 | static void mem_cgroup_out_of_memory(struct mem_cgroup *memcg, gfp_t gfp_mask, |
1536 | int order) | |
9cbb78bb DR |
1537 | { |
1538 | struct mem_cgroup *iter; | |
1539 | unsigned long chosen_points = 0; | |
1540 | unsigned long totalpages; | |
1541 | unsigned int points = 0; | |
1542 | struct task_struct *chosen = NULL; | |
1543 | ||
876aafbf | 1544 | /* |
465adcf1 DR |
1545 | * If current has a pending SIGKILL or is exiting, then automatically |
1546 | * select it. The goal is to allow it to allocate so that it may | |
1547 | * quickly exit and free its memory. | |
876aafbf | 1548 | */ |
d003f371 | 1549 | if (fatal_signal_pending(current) || task_will_free_mem(current)) { |
49550b60 | 1550 | mark_tsk_oom_victim(current); |
876aafbf DR |
1551 | return; |
1552 | } | |
1553 | ||
1554 | check_panic_on_oom(CONSTRAINT_MEMCG, gfp_mask, order, NULL); | |
3e32cb2e | 1555 | totalpages = mem_cgroup_get_limit(memcg) ? : 1; |
9cbb78bb | 1556 | for_each_mem_cgroup_tree(iter, memcg) { |
72ec7029 | 1557 | struct css_task_iter it; |
9cbb78bb DR |
1558 | struct task_struct *task; |
1559 | ||
72ec7029 TH |
1560 | css_task_iter_start(&iter->css, &it); |
1561 | while ((task = css_task_iter_next(&it))) { | |
9cbb78bb DR |
1562 | switch (oom_scan_process_thread(task, totalpages, NULL, |
1563 | false)) { | |
1564 | case OOM_SCAN_SELECT: | |
1565 | if (chosen) | |
1566 | put_task_struct(chosen); | |
1567 | chosen = task; | |
1568 | chosen_points = ULONG_MAX; | |
1569 | get_task_struct(chosen); | |
1570 | /* fall through */ | |
1571 | case OOM_SCAN_CONTINUE: | |
1572 | continue; | |
1573 | case OOM_SCAN_ABORT: | |
72ec7029 | 1574 | css_task_iter_end(&it); |
9cbb78bb DR |
1575 | mem_cgroup_iter_break(memcg, iter); |
1576 | if (chosen) | |
1577 | put_task_struct(chosen); | |
1578 | return; | |
1579 | case OOM_SCAN_OK: | |
1580 | break; | |
1581 | }; | |
1582 | points = oom_badness(task, memcg, NULL, totalpages); | |
d49ad935 DR |
1583 | if (!points || points < chosen_points) |
1584 | continue; | |
1585 | /* Prefer thread group leaders for display purposes */ | |
1586 | if (points == chosen_points && | |
1587 | thread_group_leader(chosen)) | |
1588 | continue; | |
1589 | ||
1590 | if (chosen) | |
1591 | put_task_struct(chosen); | |
1592 | chosen = task; | |
1593 | chosen_points = points; | |
1594 | get_task_struct(chosen); | |
9cbb78bb | 1595 | } |
72ec7029 | 1596 | css_task_iter_end(&it); |
9cbb78bb DR |
1597 | } |
1598 | ||
1599 | if (!chosen) | |
1600 | return; | |
1601 | points = chosen_points * 1000 / totalpages; | |
9cbb78bb DR |
1602 | oom_kill_process(chosen, gfp_mask, order, points, totalpages, memcg, |
1603 | NULL, "Memory cgroup out of memory"); | |
9cbb78bb DR |
1604 | } |
1605 | ||
ae6e71d3 MC |
1606 | #if MAX_NUMNODES > 1 |
1607 | ||
4d0c066d KH |
1608 | /** |
1609 | * test_mem_cgroup_node_reclaimable | |
dad7557e | 1610 | * @memcg: the target memcg |
4d0c066d KH |
1611 | * @nid: the node ID to be checked. |
1612 | * @noswap : specify true here if the user wants flle only information. | |
1613 | * | |
1614 | * This function returns whether the specified memcg contains any | |
1615 | * reclaimable pages on a node. Returns true if there are any reclaimable | |
1616 | * pages in the node. | |
1617 | */ | |
c0ff4b85 | 1618 | static bool test_mem_cgroup_node_reclaimable(struct mem_cgroup *memcg, |
4d0c066d KH |
1619 | int nid, bool noswap) |
1620 | { | |
c0ff4b85 | 1621 | if (mem_cgroup_node_nr_lru_pages(memcg, nid, LRU_ALL_FILE)) |
4d0c066d KH |
1622 | return true; |
1623 | if (noswap || !total_swap_pages) | |
1624 | return false; | |
c0ff4b85 | 1625 | if (mem_cgroup_node_nr_lru_pages(memcg, nid, LRU_ALL_ANON)) |
4d0c066d KH |
1626 | return true; |
1627 | return false; | |
1628 | ||
1629 | } | |
889976db YH |
1630 | |
1631 | /* | |
1632 | * Always updating the nodemask is not very good - even if we have an empty | |
1633 | * list or the wrong list here, we can start from some node and traverse all | |
1634 | * nodes based on the zonelist. So update the list loosely once per 10 secs. | |
1635 | * | |
1636 | */ | |
c0ff4b85 | 1637 | static void mem_cgroup_may_update_nodemask(struct mem_cgroup *memcg) |
889976db YH |
1638 | { |
1639 | int nid; | |
453a9bf3 KH |
1640 | /* |
1641 | * numainfo_events > 0 means there was at least NUMAINFO_EVENTS_TARGET | |
1642 | * pagein/pageout changes since the last update. | |
1643 | */ | |
c0ff4b85 | 1644 | if (!atomic_read(&memcg->numainfo_events)) |
453a9bf3 | 1645 | return; |
c0ff4b85 | 1646 | if (atomic_inc_return(&memcg->numainfo_updating) > 1) |
889976db YH |
1647 | return; |
1648 | ||
889976db | 1649 | /* make a nodemask where this memcg uses memory from */ |
31aaea4a | 1650 | memcg->scan_nodes = node_states[N_MEMORY]; |
889976db | 1651 | |
31aaea4a | 1652 | for_each_node_mask(nid, node_states[N_MEMORY]) { |
889976db | 1653 | |
c0ff4b85 R |
1654 | if (!test_mem_cgroup_node_reclaimable(memcg, nid, false)) |
1655 | node_clear(nid, memcg->scan_nodes); | |
889976db | 1656 | } |
453a9bf3 | 1657 | |
c0ff4b85 R |
1658 | atomic_set(&memcg->numainfo_events, 0); |
1659 | atomic_set(&memcg->numainfo_updating, 0); | |
889976db YH |
1660 | } |
1661 | ||
1662 | /* | |
1663 | * Selecting a node where we start reclaim from. Because what we need is just | |
1664 | * reducing usage counter, start from anywhere is O,K. Considering | |
1665 | * memory reclaim from current node, there are pros. and cons. | |
1666 | * | |
1667 | * Freeing memory from current node means freeing memory from a node which | |
1668 | * we'll use or we've used. So, it may make LRU bad. And if several threads | |
1669 | * hit limits, it will see a contention on a node. But freeing from remote | |
1670 | * node means more costs for memory reclaim because of memory latency. | |
1671 | * | |
1672 | * Now, we use round-robin. Better algorithm is welcomed. | |
1673 | */ | |
c0ff4b85 | 1674 | int mem_cgroup_select_victim_node(struct mem_cgroup *memcg) |
889976db YH |
1675 | { |
1676 | int node; | |
1677 | ||
c0ff4b85 R |
1678 | mem_cgroup_may_update_nodemask(memcg); |
1679 | node = memcg->last_scanned_node; | |
889976db | 1680 | |
c0ff4b85 | 1681 | node = next_node(node, memcg->scan_nodes); |
889976db | 1682 | if (node == MAX_NUMNODES) |
c0ff4b85 | 1683 | node = first_node(memcg->scan_nodes); |
889976db YH |
1684 | /* |
1685 | * We call this when we hit limit, not when pages are added to LRU. | |
1686 | * No LRU may hold pages because all pages are UNEVICTABLE or | |
1687 | * memcg is too small and all pages are not on LRU. In that case, | |
1688 | * we use curret node. | |
1689 | */ | |
1690 | if (unlikely(node == MAX_NUMNODES)) | |
1691 | node = numa_node_id(); | |
1692 | ||
c0ff4b85 | 1693 | memcg->last_scanned_node = node; |
889976db YH |
1694 | return node; |
1695 | } | |
889976db | 1696 | #else |
c0ff4b85 | 1697 | int mem_cgroup_select_victim_node(struct mem_cgroup *memcg) |
889976db YH |
1698 | { |
1699 | return 0; | |
1700 | } | |
1701 | #endif | |
1702 | ||
0608f43d AM |
1703 | static int mem_cgroup_soft_reclaim(struct mem_cgroup *root_memcg, |
1704 | struct zone *zone, | |
1705 | gfp_t gfp_mask, | |
1706 | unsigned long *total_scanned) | |
1707 | { | |
1708 | struct mem_cgroup *victim = NULL; | |
1709 | int total = 0; | |
1710 | int loop = 0; | |
1711 | unsigned long excess; | |
1712 | unsigned long nr_scanned; | |
1713 | struct mem_cgroup_reclaim_cookie reclaim = { | |
1714 | .zone = zone, | |
1715 | .priority = 0, | |
1716 | }; | |
1717 | ||
3e32cb2e | 1718 | excess = soft_limit_excess(root_memcg); |
0608f43d AM |
1719 | |
1720 | while (1) { | |
1721 | victim = mem_cgroup_iter(root_memcg, victim, &reclaim); | |
1722 | if (!victim) { | |
1723 | loop++; | |
1724 | if (loop >= 2) { | |
1725 | /* | |
1726 | * If we have not been able to reclaim | |
1727 | * anything, it might because there are | |
1728 | * no reclaimable pages under this hierarchy | |
1729 | */ | |
1730 | if (!total) | |
1731 | break; | |
1732 | /* | |
1733 | * We want to do more targeted reclaim. | |
1734 | * excess >> 2 is not to excessive so as to | |
1735 | * reclaim too much, nor too less that we keep | |
1736 | * coming back to reclaim from this cgroup | |
1737 | */ | |
1738 | if (total >= (excess >> 2) || | |
1739 | (loop > MEM_CGROUP_MAX_RECLAIM_LOOPS)) | |
1740 | break; | |
1741 | } | |
1742 | continue; | |
1743 | } | |
0608f43d AM |
1744 | total += mem_cgroup_shrink_node_zone(victim, gfp_mask, false, |
1745 | zone, &nr_scanned); | |
1746 | *total_scanned += nr_scanned; | |
3e32cb2e | 1747 | if (!soft_limit_excess(root_memcg)) |
0608f43d | 1748 | break; |
6d61ef40 | 1749 | } |
0608f43d AM |
1750 | mem_cgroup_iter_break(root_memcg, victim); |
1751 | return total; | |
6d61ef40 BS |
1752 | } |
1753 | ||
0056f4e6 JW |
1754 | #ifdef CONFIG_LOCKDEP |
1755 | static struct lockdep_map memcg_oom_lock_dep_map = { | |
1756 | .name = "memcg_oom_lock", | |
1757 | }; | |
1758 | #endif | |
1759 | ||
fb2a6fc5 JW |
1760 | static DEFINE_SPINLOCK(memcg_oom_lock); |
1761 | ||
867578cb KH |
1762 | /* |
1763 | * Check OOM-Killer is already running under our hierarchy. | |
1764 | * If someone is running, return false. | |
1765 | */ | |
fb2a6fc5 | 1766 | static bool mem_cgroup_oom_trylock(struct mem_cgroup *memcg) |
867578cb | 1767 | { |
79dfdacc | 1768 | struct mem_cgroup *iter, *failed = NULL; |
a636b327 | 1769 | |
fb2a6fc5 JW |
1770 | spin_lock(&memcg_oom_lock); |
1771 | ||
9f3a0d09 | 1772 | for_each_mem_cgroup_tree(iter, memcg) { |
23751be0 | 1773 | if (iter->oom_lock) { |
79dfdacc MH |
1774 | /* |
1775 | * this subtree of our hierarchy is already locked | |
1776 | * so we cannot give a lock. | |
1777 | */ | |
79dfdacc | 1778 | failed = iter; |
9f3a0d09 JW |
1779 | mem_cgroup_iter_break(memcg, iter); |
1780 | break; | |
23751be0 JW |
1781 | } else |
1782 | iter->oom_lock = true; | |
7d74b06f | 1783 | } |
867578cb | 1784 | |
fb2a6fc5 JW |
1785 | if (failed) { |
1786 | /* | |
1787 | * OK, we failed to lock the whole subtree so we have | |
1788 | * to clean up what we set up to the failing subtree | |
1789 | */ | |
1790 | for_each_mem_cgroup_tree(iter, memcg) { | |
1791 | if (iter == failed) { | |
1792 | mem_cgroup_iter_break(memcg, iter); | |
1793 | break; | |
1794 | } | |
1795 | iter->oom_lock = false; | |
79dfdacc | 1796 | } |
0056f4e6 JW |
1797 | } else |
1798 | mutex_acquire(&memcg_oom_lock_dep_map, 0, 1, _RET_IP_); | |
fb2a6fc5 JW |
1799 | |
1800 | spin_unlock(&memcg_oom_lock); | |
1801 | ||
1802 | return !failed; | |
a636b327 | 1803 | } |
0b7f569e | 1804 | |
fb2a6fc5 | 1805 | static void mem_cgroup_oom_unlock(struct mem_cgroup *memcg) |
0b7f569e | 1806 | { |
7d74b06f KH |
1807 | struct mem_cgroup *iter; |
1808 | ||
fb2a6fc5 | 1809 | spin_lock(&memcg_oom_lock); |
0056f4e6 | 1810 | mutex_release(&memcg_oom_lock_dep_map, 1, _RET_IP_); |
c0ff4b85 | 1811 | for_each_mem_cgroup_tree(iter, memcg) |
79dfdacc | 1812 | iter->oom_lock = false; |
fb2a6fc5 | 1813 | spin_unlock(&memcg_oom_lock); |
79dfdacc MH |
1814 | } |
1815 | ||
c0ff4b85 | 1816 | static void mem_cgroup_mark_under_oom(struct mem_cgroup *memcg) |
79dfdacc MH |
1817 | { |
1818 | struct mem_cgroup *iter; | |
1819 | ||
c0ff4b85 | 1820 | for_each_mem_cgroup_tree(iter, memcg) |
79dfdacc MH |
1821 | atomic_inc(&iter->under_oom); |
1822 | } | |
1823 | ||
c0ff4b85 | 1824 | static void mem_cgroup_unmark_under_oom(struct mem_cgroup *memcg) |
79dfdacc MH |
1825 | { |
1826 | struct mem_cgroup *iter; | |
1827 | ||
867578cb KH |
1828 | /* |
1829 | * When a new child is created while the hierarchy is under oom, | |
1830 | * mem_cgroup_oom_lock() may not be called. We have to use | |
1831 | * atomic_add_unless() here. | |
1832 | */ | |
c0ff4b85 | 1833 | for_each_mem_cgroup_tree(iter, memcg) |
79dfdacc | 1834 | atomic_add_unless(&iter->under_oom, -1, 0); |
0b7f569e KH |
1835 | } |
1836 | ||
867578cb KH |
1837 | static DECLARE_WAIT_QUEUE_HEAD(memcg_oom_waitq); |
1838 | ||
dc98df5a | 1839 | struct oom_wait_info { |
d79154bb | 1840 | struct mem_cgroup *memcg; |
dc98df5a KH |
1841 | wait_queue_t wait; |
1842 | }; | |
1843 | ||
1844 | static int memcg_oom_wake_function(wait_queue_t *wait, | |
1845 | unsigned mode, int sync, void *arg) | |
1846 | { | |
d79154bb HD |
1847 | struct mem_cgroup *wake_memcg = (struct mem_cgroup *)arg; |
1848 | struct mem_cgroup *oom_wait_memcg; | |
dc98df5a KH |
1849 | struct oom_wait_info *oom_wait_info; |
1850 | ||
1851 | oom_wait_info = container_of(wait, struct oom_wait_info, wait); | |
d79154bb | 1852 | oom_wait_memcg = oom_wait_info->memcg; |
dc98df5a | 1853 | |
2314b42d JW |
1854 | if (!mem_cgroup_is_descendant(wake_memcg, oom_wait_memcg) && |
1855 | !mem_cgroup_is_descendant(oom_wait_memcg, wake_memcg)) | |
dc98df5a | 1856 | return 0; |
dc98df5a KH |
1857 | return autoremove_wake_function(wait, mode, sync, arg); |
1858 | } | |
1859 | ||
c0ff4b85 | 1860 | static void memcg_wakeup_oom(struct mem_cgroup *memcg) |
dc98df5a | 1861 | { |
3812c8c8 | 1862 | atomic_inc(&memcg->oom_wakeups); |
c0ff4b85 R |
1863 | /* for filtering, pass "memcg" as argument. */ |
1864 | __wake_up(&memcg_oom_waitq, TASK_NORMAL, 0, memcg); | |
dc98df5a KH |
1865 | } |
1866 | ||
c0ff4b85 | 1867 | static void memcg_oom_recover(struct mem_cgroup *memcg) |
3c11ecf4 | 1868 | { |
c0ff4b85 R |
1869 | if (memcg && atomic_read(&memcg->under_oom)) |
1870 | memcg_wakeup_oom(memcg); | |
3c11ecf4 KH |
1871 | } |
1872 | ||
3812c8c8 | 1873 | static void mem_cgroup_oom(struct mem_cgroup *memcg, gfp_t mask, int order) |
0b7f569e | 1874 | { |
3812c8c8 JW |
1875 | if (!current->memcg_oom.may_oom) |
1876 | return; | |
867578cb | 1877 | /* |
49426420 JW |
1878 | * We are in the middle of the charge context here, so we |
1879 | * don't want to block when potentially sitting on a callstack | |
1880 | * that holds all kinds of filesystem and mm locks. | |
1881 | * | |
1882 | * Also, the caller may handle a failed allocation gracefully | |
1883 | * (like optional page cache readahead) and so an OOM killer | |
1884 | * invocation might not even be necessary. | |
1885 | * | |
1886 | * That's why we don't do anything here except remember the | |
1887 | * OOM context and then deal with it at the end of the page | |
1888 | * fault when the stack is unwound, the locks are released, | |
1889 | * and when we know whether the fault was overall successful. | |
867578cb | 1890 | */ |
49426420 JW |
1891 | css_get(&memcg->css); |
1892 | current->memcg_oom.memcg = memcg; | |
1893 | current->memcg_oom.gfp_mask = mask; | |
1894 | current->memcg_oom.order = order; | |
3812c8c8 JW |
1895 | } |
1896 | ||
1897 | /** | |
1898 | * mem_cgroup_oom_synchronize - complete memcg OOM handling | |
49426420 | 1899 | * @handle: actually kill/wait or just clean up the OOM state |
3812c8c8 | 1900 | * |
49426420 JW |
1901 | * This has to be called at the end of a page fault if the memcg OOM |
1902 | * handler was enabled. | |
3812c8c8 | 1903 | * |
49426420 | 1904 | * Memcg supports userspace OOM handling where failed allocations must |
3812c8c8 JW |
1905 | * sleep on a waitqueue until the userspace task resolves the |
1906 | * situation. Sleeping directly in the charge context with all kinds | |
1907 | * of locks held is not a good idea, instead we remember an OOM state | |
1908 | * in the task and mem_cgroup_oom_synchronize() has to be called at | |
49426420 | 1909 | * the end of the page fault to complete the OOM handling. |
3812c8c8 JW |
1910 | * |
1911 | * Returns %true if an ongoing memcg OOM situation was detected and | |
49426420 | 1912 | * completed, %false otherwise. |
3812c8c8 | 1913 | */ |
49426420 | 1914 | bool mem_cgroup_oom_synchronize(bool handle) |
3812c8c8 | 1915 | { |
49426420 | 1916 | struct mem_cgroup *memcg = current->memcg_oom.memcg; |
3812c8c8 | 1917 | struct oom_wait_info owait; |
49426420 | 1918 | bool locked; |
3812c8c8 JW |
1919 | |
1920 | /* OOM is global, do not handle */ | |
3812c8c8 | 1921 | if (!memcg) |
49426420 | 1922 | return false; |
3812c8c8 | 1923 | |
c32b3cbe | 1924 | if (!handle || oom_killer_disabled) |
49426420 | 1925 | goto cleanup; |
3812c8c8 JW |
1926 | |
1927 | owait.memcg = memcg; | |
1928 | owait.wait.flags = 0; | |
1929 | owait.wait.func = memcg_oom_wake_function; | |
1930 | owait.wait.private = current; | |
1931 | INIT_LIST_HEAD(&owait.wait.task_list); | |
867578cb | 1932 | |
3812c8c8 | 1933 | prepare_to_wait(&memcg_oom_waitq, &owait.wait, TASK_KILLABLE); |
49426420 JW |
1934 | mem_cgroup_mark_under_oom(memcg); |
1935 | ||
1936 | locked = mem_cgroup_oom_trylock(memcg); | |
1937 | ||
1938 | if (locked) | |
1939 | mem_cgroup_oom_notify(memcg); | |
1940 | ||
1941 | if (locked && !memcg->oom_kill_disable) { | |
1942 | mem_cgroup_unmark_under_oom(memcg); | |
1943 | finish_wait(&memcg_oom_waitq, &owait.wait); | |
1944 | mem_cgroup_out_of_memory(memcg, current->memcg_oom.gfp_mask, | |
1945 | current->memcg_oom.order); | |
1946 | } else { | |
3812c8c8 | 1947 | schedule(); |
49426420 JW |
1948 | mem_cgroup_unmark_under_oom(memcg); |
1949 | finish_wait(&memcg_oom_waitq, &owait.wait); | |
1950 | } | |
1951 | ||
1952 | if (locked) { | |
fb2a6fc5 JW |
1953 | mem_cgroup_oom_unlock(memcg); |
1954 | /* | |
1955 | * There is no guarantee that an OOM-lock contender | |
1956 | * sees the wakeups triggered by the OOM kill | |
1957 | * uncharges. Wake any sleepers explicitely. | |
1958 | */ | |
1959 | memcg_oom_recover(memcg); | |
1960 | } | |
49426420 JW |
1961 | cleanup: |
1962 | current->memcg_oom.memcg = NULL; | |
3812c8c8 | 1963 | css_put(&memcg->css); |
867578cb | 1964 | return true; |
0b7f569e KH |
1965 | } |
1966 | ||
d7365e78 JW |
1967 | /** |
1968 | * mem_cgroup_begin_page_stat - begin a page state statistics transaction | |
1969 | * @page: page that is going to change accounted state | |
32047e2a | 1970 | * |
d7365e78 JW |
1971 | * This function must mark the beginning of an accounted page state |
1972 | * change to prevent double accounting when the page is concurrently | |
1973 | * being moved to another memcg: | |
32047e2a | 1974 | * |
6de22619 | 1975 | * memcg = mem_cgroup_begin_page_stat(page); |
d7365e78 JW |
1976 | * if (TestClearPageState(page)) |
1977 | * mem_cgroup_update_page_stat(memcg, state, -1); | |
6de22619 | 1978 | * mem_cgroup_end_page_stat(memcg); |
d69b042f | 1979 | */ |
6de22619 | 1980 | struct mem_cgroup *mem_cgroup_begin_page_stat(struct page *page) |
89c06bd5 KH |
1981 | { |
1982 | struct mem_cgroup *memcg; | |
6de22619 | 1983 | unsigned long flags; |
89c06bd5 | 1984 | |
6de22619 JW |
1985 | /* |
1986 | * The RCU lock is held throughout the transaction. The fast | |
1987 | * path can get away without acquiring the memcg->move_lock | |
1988 | * because page moving starts with an RCU grace period. | |
1989 | * | |
1990 | * The RCU lock also protects the memcg from being freed when | |
1991 | * the page state that is going to change is the only thing | |
1992 | * preventing the page from being uncharged. | |
1993 | * E.g. end-writeback clearing PageWriteback(), which allows | |
1994 | * migration to go ahead and uncharge the page before the | |
1995 | * account transaction might be complete. | |
1996 | */ | |
d7365e78 JW |
1997 | rcu_read_lock(); |
1998 | ||
1999 | if (mem_cgroup_disabled()) | |
2000 | return NULL; | |
89c06bd5 | 2001 | again: |
1306a85a | 2002 | memcg = page->mem_cgroup; |
29833315 | 2003 | if (unlikely(!memcg)) |
d7365e78 JW |
2004 | return NULL; |
2005 | ||
bdcbb659 | 2006 | if (atomic_read(&memcg->moving_account) <= 0) |
d7365e78 | 2007 | return memcg; |
89c06bd5 | 2008 | |
6de22619 | 2009 | spin_lock_irqsave(&memcg->move_lock, flags); |
1306a85a | 2010 | if (memcg != page->mem_cgroup) { |
6de22619 | 2011 | spin_unlock_irqrestore(&memcg->move_lock, flags); |
89c06bd5 KH |
2012 | goto again; |
2013 | } | |
6de22619 JW |
2014 | |
2015 | /* | |
2016 | * When charge migration first begins, we can have locked and | |
2017 | * unlocked page stat updates happening concurrently. Track | |
2018 | * the task who has the lock for mem_cgroup_end_page_stat(). | |
2019 | */ | |
2020 | memcg->move_lock_task = current; | |
2021 | memcg->move_lock_flags = flags; | |
d7365e78 JW |
2022 | |
2023 | return memcg; | |
89c06bd5 KH |
2024 | } |
2025 | ||
d7365e78 JW |
2026 | /** |
2027 | * mem_cgroup_end_page_stat - finish a page state statistics transaction | |
2028 | * @memcg: the memcg that was accounted against | |
d7365e78 | 2029 | */ |
6de22619 | 2030 | void mem_cgroup_end_page_stat(struct mem_cgroup *memcg) |
89c06bd5 | 2031 | { |
6de22619 JW |
2032 | if (memcg && memcg->move_lock_task == current) { |
2033 | unsigned long flags = memcg->move_lock_flags; | |
2034 | ||
2035 | memcg->move_lock_task = NULL; | |
2036 | memcg->move_lock_flags = 0; | |
2037 | ||
2038 | spin_unlock_irqrestore(&memcg->move_lock, flags); | |
2039 | } | |
89c06bd5 | 2040 | |
d7365e78 | 2041 | rcu_read_unlock(); |
89c06bd5 KH |
2042 | } |
2043 | ||
d7365e78 JW |
2044 | /** |
2045 | * mem_cgroup_update_page_stat - update page state statistics | |
2046 | * @memcg: memcg to account against | |
2047 | * @idx: page state item to account | |
2048 | * @val: number of pages (positive or negative) | |
2049 | * | |
2050 | * See mem_cgroup_begin_page_stat() for locking requirements. | |
2051 | */ | |
2052 | void mem_cgroup_update_page_stat(struct mem_cgroup *memcg, | |
68b4876d | 2053 | enum mem_cgroup_stat_index idx, int val) |
d69b042f | 2054 | { |
658b72c5 | 2055 | VM_BUG_ON(!rcu_read_lock_held()); |
26174efd | 2056 | |
d7365e78 JW |
2057 | if (memcg) |
2058 | this_cpu_add(memcg->stat->count[idx], val); | |
d69b042f | 2059 | } |
26174efd | 2060 | |
cdec2e42 KH |
2061 | /* |
2062 | * size of first charge trial. "32" comes from vmscan.c's magic value. | |
2063 | * TODO: maybe necessary to use big numbers in big irons. | |
2064 | */ | |
7ec99d62 | 2065 | #define CHARGE_BATCH 32U |
cdec2e42 KH |
2066 | struct memcg_stock_pcp { |
2067 | struct mem_cgroup *cached; /* this never be root cgroup */ | |
11c9ea4e | 2068 | unsigned int nr_pages; |
cdec2e42 | 2069 | struct work_struct work; |
26fe6168 | 2070 | unsigned long flags; |
a0db00fc | 2071 | #define FLUSHING_CACHED_CHARGE 0 |
cdec2e42 KH |
2072 | }; |
2073 | static DEFINE_PER_CPU(struct memcg_stock_pcp, memcg_stock); | |
9f50fad6 | 2074 | static DEFINE_MUTEX(percpu_charge_mutex); |
cdec2e42 | 2075 | |
a0956d54 SS |
2076 | /** |
2077 | * consume_stock: Try to consume stocked charge on this cpu. | |
2078 | * @memcg: memcg to consume from. | |
2079 | * @nr_pages: how many pages to charge. | |
2080 | * | |
2081 | * The charges will only happen if @memcg matches the current cpu's memcg | |
2082 | * stock, and at least @nr_pages are available in that stock. Failure to | |
2083 | * service an allocation will refill the stock. | |
2084 | * | |
2085 | * returns true if successful, false otherwise. | |
cdec2e42 | 2086 | */ |
a0956d54 | 2087 | static bool consume_stock(struct mem_cgroup *memcg, unsigned int nr_pages) |
cdec2e42 KH |
2088 | { |
2089 | struct memcg_stock_pcp *stock; | |
3e32cb2e | 2090 | bool ret = false; |
cdec2e42 | 2091 | |
a0956d54 | 2092 | if (nr_pages > CHARGE_BATCH) |
3e32cb2e | 2093 | return ret; |
a0956d54 | 2094 | |
cdec2e42 | 2095 | stock = &get_cpu_var(memcg_stock); |
3e32cb2e | 2096 | if (memcg == stock->cached && stock->nr_pages >= nr_pages) { |
a0956d54 | 2097 | stock->nr_pages -= nr_pages; |
3e32cb2e JW |
2098 | ret = true; |
2099 | } | |
cdec2e42 KH |
2100 | put_cpu_var(memcg_stock); |
2101 | return ret; | |
2102 | } | |
2103 | ||
2104 | /* | |
3e32cb2e | 2105 | * Returns stocks cached in percpu and reset cached information. |
cdec2e42 KH |
2106 | */ |
2107 | static void drain_stock(struct memcg_stock_pcp *stock) | |
2108 | { | |
2109 | struct mem_cgroup *old = stock->cached; | |
2110 | ||
11c9ea4e | 2111 | if (stock->nr_pages) { |
3e32cb2e | 2112 | page_counter_uncharge(&old->memory, stock->nr_pages); |
cdec2e42 | 2113 | if (do_swap_account) |
3e32cb2e | 2114 | page_counter_uncharge(&old->memsw, stock->nr_pages); |
e8ea14cc | 2115 | css_put_many(&old->css, stock->nr_pages); |
11c9ea4e | 2116 | stock->nr_pages = 0; |
cdec2e42 KH |
2117 | } |
2118 | stock->cached = NULL; | |
cdec2e42 KH |
2119 | } |
2120 | ||
2121 | /* | |
2122 | * This must be called under preempt disabled or must be called by | |
2123 | * a thread which is pinned to local cpu. | |
2124 | */ | |
2125 | static void drain_local_stock(struct work_struct *dummy) | |
2126 | { | |
7c8e0181 | 2127 | struct memcg_stock_pcp *stock = this_cpu_ptr(&memcg_stock); |
cdec2e42 | 2128 | drain_stock(stock); |
26fe6168 | 2129 | clear_bit(FLUSHING_CACHED_CHARGE, &stock->flags); |
cdec2e42 KH |
2130 | } |
2131 | ||
2132 | /* | |
3e32cb2e | 2133 | * Cache charges(val) to local per_cpu area. |
320cc51d | 2134 | * This will be consumed by consume_stock() function, later. |
cdec2e42 | 2135 | */ |
c0ff4b85 | 2136 | static void refill_stock(struct mem_cgroup *memcg, unsigned int nr_pages) |
cdec2e42 KH |
2137 | { |
2138 | struct memcg_stock_pcp *stock = &get_cpu_var(memcg_stock); | |
2139 | ||
c0ff4b85 | 2140 | if (stock->cached != memcg) { /* reset if necessary */ |
cdec2e42 | 2141 | drain_stock(stock); |
c0ff4b85 | 2142 | stock->cached = memcg; |
cdec2e42 | 2143 | } |
11c9ea4e | 2144 | stock->nr_pages += nr_pages; |
cdec2e42 KH |
2145 | put_cpu_var(memcg_stock); |
2146 | } | |
2147 | ||
2148 | /* | |
c0ff4b85 | 2149 | * Drains all per-CPU charge caches for given root_memcg resp. subtree |
6d3d6aa2 | 2150 | * of the hierarchy under it. |
cdec2e42 | 2151 | */ |
6d3d6aa2 | 2152 | static void drain_all_stock(struct mem_cgroup *root_memcg) |
cdec2e42 | 2153 | { |
26fe6168 | 2154 | int cpu, curcpu; |
d38144b7 | 2155 | |
6d3d6aa2 JW |
2156 | /* If someone's already draining, avoid adding running more workers. */ |
2157 | if (!mutex_trylock(&percpu_charge_mutex)) | |
2158 | return; | |
cdec2e42 | 2159 | /* Notify other cpus that system-wide "drain" is running */ |
cdec2e42 | 2160 | get_online_cpus(); |
5af12d0e | 2161 | curcpu = get_cpu(); |
cdec2e42 KH |
2162 | for_each_online_cpu(cpu) { |
2163 | struct memcg_stock_pcp *stock = &per_cpu(memcg_stock, cpu); | |
c0ff4b85 | 2164 | struct mem_cgroup *memcg; |
26fe6168 | 2165 | |
c0ff4b85 R |
2166 | memcg = stock->cached; |
2167 | if (!memcg || !stock->nr_pages) | |
26fe6168 | 2168 | continue; |
2314b42d | 2169 | if (!mem_cgroup_is_descendant(memcg, root_memcg)) |
3e92041d | 2170 | continue; |
d1a05b69 MH |
2171 | if (!test_and_set_bit(FLUSHING_CACHED_CHARGE, &stock->flags)) { |
2172 | if (cpu == curcpu) | |
2173 | drain_local_stock(&stock->work); | |
2174 | else | |
2175 | schedule_work_on(cpu, &stock->work); | |
2176 | } | |
cdec2e42 | 2177 | } |
5af12d0e | 2178 | put_cpu(); |
f894ffa8 | 2179 | put_online_cpus(); |
9f50fad6 | 2180 | mutex_unlock(&percpu_charge_mutex); |
cdec2e42 KH |
2181 | } |
2182 | ||
711d3d2c KH |
2183 | /* |
2184 | * This function drains percpu counter value from DEAD cpu and | |
2185 | * move it to local cpu. Note that this function can be preempted. | |
2186 | */ | |
c0ff4b85 | 2187 | static void mem_cgroup_drain_pcp_counter(struct mem_cgroup *memcg, int cpu) |
711d3d2c KH |
2188 | { |
2189 | int i; | |
2190 | ||
c0ff4b85 | 2191 | spin_lock(&memcg->pcp_counter_lock); |
6104621d | 2192 | for (i = 0; i < MEM_CGROUP_STAT_NSTATS; i++) { |
c0ff4b85 | 2193 | long x = per_cpu(memcg->stat->count[i], cpu); |
711d3d2c | 2194 | |
c0ff4b85 R |
2195 | per_cpu(memcg->stat->count[i], cpu) = 0; |
2196 | memcg->nocpu_base.count[i] += x; | |
711d3d2c | 2197 | } |
e9f8974f | 2198 | for (i = 0; i < MEM_CGROUP_EVENTS_NSTATS; i++) { |
c0ff4b85 | 2199 | unsigned long x = per_cpu(memcg->stat->events[i], cpu); |
e9f8974f | 2200 | |
c0ff4b85 R |
2201 | per_cpu(memcg->stat->events[i], cpu) = 0; |
2202 | memcg->nocpu_base.events[i] += x; | |
e9f8974f | 2203 | } |
c0ff4b85 | 2204 | spin_unlock(&memcg->pcp_counter_lock); |
711d3d2c KH |
2205 | } |
2206 | ||
0db0628d | 2207 | static int memcg_cpu_hotplug_callback(struct notifier_block *nb, |
cdec2e42 KH |
2208 | unsigned long action, |
2209 | void *hcpu) | |
2210 | { | |
2211 | int cpu = (unsigned long)hcpu; | |
2212 | struct memcg_stock_pcp *stock; | |
711d3d2c | 2213 | struct mem_cgroup *iter; |
cdec2e42 | 2214 | |
619d094b | 2215 | if (action == CPU_ONLINE) |
1489ebad | 2216 | return NOTIFY_OK; |
1489ebad | 2217 | |
d833049b | 2218 | if (action != CPU_DEAD && action != CPU_DEAD_FROZEN) |
cdec2e42 | 2219 | return NOTIFY_OK; |
711d3d2c | 2220 | |
9f3a0d09 | 2221 | for_each_mem_cgroup(iter) |
711d3d2c KH |
2222 | mem_cgroup_drain_pcp_counter(iter, cpu); |
2223 | ||
cdec2e42 KH |
2224 | stock = &per_cpu(memcg_stock, cpu); |
2225 | drain_stock(stock); | |
2226 | return NOTIFY_OK; | |
2227 | } | |
2228 | ||
00501b53 JW |
2229 | static int try_charge(struct mem_cgroup *memcg, gfp_t gfp_mask, |
2230 | unsigned int nr_pages) | |
8a9f3ccd | 2231 | { |
7ec99d62 | 2232 | unsigned int batch = max(CHARGE_BATCH, nr_pages); |
9b130619 | 2233 | int nr_retries = MEM_CGROUP_RECLAIM_RETRIES; |
6539cc05 | 2234 | struct mem_cgroup *mem_over_limit; |
3e32cb2e | 2235 | struct page_counter *counter; |
6539cc05 | 2236 | unsigned long nr_reclaimed; |
b70a2a21 JW |
2237 | bool may_swap = true; |
2238 | bool drained = false; | |
05b84301 | 2239 | int ret = 0; |
a636b327 | 2240 | |
ce00a967 JW |
2241 | if (mem_cgroup_is_root(memcg)) |
2242 | goto done; | |
6539cc05 | 2243 | retry: |
b6b6cc72 MH |
2244 | if (consume_stock(memcg, nr_pages)) |
2245 | goto done; | |
8a9f3ccd | 2246 | |
3fbe7244 | 2247 | if (!do_swap_account || |
3e32cb2e JW |
2248 | !page_counter_try_charge(&memcg->memsw, batch, &counter)) { |
2249 | if (!page_counter_try_charge(&memcg->memory, batch, &counter)) | |
6539cc05 | 2250 | goto done_restock; |
3fbe7244 | 2251 | if (do_swap_account) |
3e32cb2e JW |
2252 | page_counter_uncharge(&memcg->memsw, batch); |
2253 | mem_over_limit = mem_cgroup_from_counter(counter, memory); | |
3fbe7244 | 2254 | } else { |
3e32cb2e | 2255 | mem_over_limit = mem_cgroup_from_counter(counter, memsw); |
b70a2a21 | 2256 | may_swap = false; |
3fbe7244 | 2257 | } |
7a81b88c | 2258 | |
6539cc05 JW |
2259 | if (batch > nr_pages) { |
2260 | batch = nr_pages; | |
2261 | goto retry; | |
2262 | } | |
6d61ef40 | 2263 | |
06b078fc JW |
2264 | /* |
2265 | * Unlike in global OOM situations, memcg is not in a physical | |
2266 | * memory shortage. Allow dying and OOM-killed tasks to | |
2267 | * bypass the last charges so that they can exit quickly and | |
2268 | * free their memory. | |
2269 | */ | |
2270 | if (unlikely(test_thread_flag(TIF_MEMDIE) || | |
2271 | fatal_signal_pending(current) || | |
2272 | current->flags & PF_EXITING)) | |
2273 | goto bypass; | |
2274 | ||
2275 | if (unlikely(task_in_memcg_oom(current))) | |
2276 | goto nomem; | |
2277 | ||
6539cc05 JW |
2278 | if (!(gfp_mask & __GFP_WAIT)) |
2279 | goto nomem; | |
4b534334 | 2280 | |
241994ed JW |
2281 | mem_cgroup_events(mem_over_limit, MEMCG_MAX, 1); |
2282 | ||
b70a2a21 JW |
2283 | nr_reclaimed = try_to_free_mem_cgroup_pages(mem_over_limit, nr_pages, |
2284 | gfp_mask, may_swap); | |
6539cc05 | 2285 | |
61e02c74 | 2286 | if (mem_cgroup_margin(mem_over_limit) >= nr_pages) |
6539cc05 | 2287 | goto retry; |
28c34c29 | 2288 | |
b70a2a21 | 2289 | if (!drained) { |
6d3d6aa2 | 2290 | drain_all_stock(mem_over_limit); |
b70a2a21 JW |
2291 | drained = true; |
2292 | goto retry; | |
2293 | } | |
2294 | ||
28c34c29 JW |
2295 | if (gfp_mask & __GFP_NORETRY) |
2296 | goto nomem; | |
6539cc05 JW |
2297 | /* |
2298 | * Even though the limit is exceeded at this point, reclaim | |
2299 | * may have been able to free some pages. Retry the charge | |
2300 | * before killing the task. | |
2301 | * | |
2302 | * Only for regular pages, though: huge pages are rather | |
2303 | * unlikely to succeed so close to the limit, and we fall back | |
2304 | * to regular pages anyway in case of failure. | |
2305 | */ | |
61e02c74 | 2306 | if (nr_reclaimed && nr_pages <= (1 << PAGE_ALLOC_COSTLY_ORDER)) |
6539cc05 JW |
2307 | goto retry; |
2308 | /* | |
2309 | * At task move, charge accounts can be doubly counted. So, it's | |
2310 | * better to wait until the end of task_move if something is going on. | |
2311 | */ | |
2312 | if (mem_cgroup_wait_acct_move(mem_over_limit)) | |
2313 | goto retry; | |
2314 | ||
9b130619 JW |
2315 | if (nr_retries--) |
2316 | goto retry; | |
2317 | ||
06b078fc JW |
2318 | if (gfp_mask & __GFP_NOFAIL) |
2319 | goto bypass; | |
2320 | ||
6539cc05 JW |
2321 | if (fatal_signal_pending(current)) |
2322 | goto bypass; | |
2323 | ||
241994ed JW |
2324 | mem_cgroup_events(mem_over_limit, MEMCG_OOM, 1); |
2325 | ||
61e02c74 | 2326 | mem_cgroup_oom(mem_over_limit, gfp_mask, get_order(nr_pages)); |
7a81b88c | 2327 | nomem: |
6d1fdc48 | 2328 | if (!(gfp_mask & __GFP_NOFAIL)) |
3168ecbe | 2329 | return -ENOMEM; |
867578cb | 2330 | bypass: |
ce00a967 | 2331 | return -EINTR; |
6539cc05 JW |
2332 | |
2333 | done_restock: | |
e8ea14cc | 2334 | css_get_many(&memcg->css, batch); |
6539cc05 JW |
2335 | if (batch > nr_pages) |
2336 | refill_stock(memcg, batch - nr_pages); | |
241994ed JW |
2337 | /* |
2338 | * If the hierarchy is above the normal consumption range, | |
2339 | * make the charging task trim their excess contribution. | |
2340 | */ | |
2341 | do { | |
2342 | if (page_counter_read(&memcg->memory) <= memcg->high) | |
2343 | continue; | |
2344 | mem_cgroup_events(memcg, MEMCG_HIGH, 1); | |
2345 | try_to_free_mem_cgroup_pages(memcg, nr_pages, gfp_mask, true); | |
2346 | } while ((memcg = parent_mem_cgroup(memcg))); | |
6539cc05 | 2347 | done: |
05b84301 | 2348 | return ret; |
7a81b88c | 2349 | } |
8a9f3ccd | 2350 | |
00501b53 | 2351 | static void cancel_charge(struct mem_cgroup *memcg, unsigned int nr_pages) |
a3032a2c | 2352 | { |
ce00a967 JW |
2353 | if (mem_cgroup_is_root(memcg)) |
2354 | return; | |
2355 | ||
3e32cb2e | 2356 | page_counter_uncharge(&memcg->memory, nr_pages); |
05b84301 | 2357 | if (do_swap_account) |
3e32cb2e | 2358 | page_counter_uncharge(&memcg->memsw, nr_pages); |
ce00a967 | 2359 | |
e8ea14cc | 2360 | css_put_many(&memcg->css, nr_pages); |
d01dd17f KH |
2361 | } |
2362 | ||
a3b2d692 KH |
2363 | /* |
2364 | * A helper function to get mem_cgroup from ID. must be called under | |
ec903c0c TH |
2365 | * rcu_read_lock(). The caller is responsible for calling |
2366 | * css_tryget_online() if the mem_cgroup is used for charging. (dropping | |
2367 | * refcnt from swap can be called against removed memcg.) | |
a3b2d692 KH |
2368 | */ |
2369 | static struct mem_cgroup *mem_cgroup_lookup(unsigned short id) | |
2370 | { | |
a3b2d692 KH |
2371 | /* ID 0 is unused ID */ |
2372 | if (!id) | |
2373 | return NULL; | |
34c00c31 | 2374 | return mem_cgroup_from_id(id); |
a3b2d692 KH |
2375 | } |
2376 | ||
0a31bc97 JW |
2377 | /* |
2378 | * try_get_mem_cgroup_from_page - look up page's memcg association | |
2379 | * @page: the page | |
2380 | * | |
2381 | * Look up, get a css reference, and return the memcg that owns @page. | |
2382 | * | |
2383 | * The page must be locked to prevent racing with swap-in and page | |
2384 | * cache charges. If coming from an unlocked page table, the caller | |
2385 | * must ensure the page is on the LRU or this can race with charging. | |
2386 | */ | |
e42d9d5d | 2387 | struct mem_cgroup *try_get_mem_cgroup_from_page(struct page *page) |
b5a84319 | 2388 | { |
29833315 | 2389 | struct mem_cgroup *memcg; |
a3b2d692 | 2390 | unsigned short id; |
b5a84319 KH |
2391 | swp_entry_t ent; |
2392 | ||
309381fe | 2393 | VM_BUG_ON_PAGE(!PageLocked(page), page); |
3c776e64 | 2394 | |
1306a85a | 2395 | memcg = page->mem_cgroup; |
29833315 JW |
2396 | if (memcg) { |
2397 | if (!css_tryget_online(&memcg->css)) | |
c0ff4b85 | 2398 | memcg = NULL; |
e42d9d5d | 2399 | } else if (PageSwapCache(page)) { |
3c776e64 | 2400 | ent.val = page_private(page); |
9fb4b7cc | 2401 | id = lookup_swap_cgroup_id(ent); |
a3b2d692 | 2402 | rcu_read_lock(); |
c0ff4b85 | 2403 | memcg = mem_cgroup_lookup(id); |
ec903c0c | 2404 | if (memcg && !css_tryget_online(&memcg->css)) |
c0ff4b85 | 2405 | memcg = NULL; |
a3b2d692 | 2406 | rcu_read_unlock(); |
3c776e64 | 2407 | } |
c0ff4b85 | 2408 | return memcg; |
b5a84319 KH |
2409 | } |
2410 | ||
0a31bc97 JW |
2411 | static void lock_page_lru(struct page *page, int *isolated) |
2412 | { | |
2413 | struct zone *zone = page_zone(page); | |
2414 | ||
2415 | spin_lock_irq(&zone->lru_lock); | |
2416 | if (PageLRU(page)) { | |
2417 | struct lruvec *lruvec; | |
2418 | ||
2419 | lruvec = mem_cgroup_page_lruvec(page, zone); | |
2420 | ClearPageLRU(page); | |
2421 | del_page_from_lru_list(page, lruvec, page_lru(page)); | |
2422 | *isolated = 1; | |
2423 | } else | |
2424 | *isolated = 0; | |
2425 | } | |
2426 | ||
2427 | static void unlock_page_lru(struct page *page, int isolated) | |
2428 | { | |
2429 | struct zone *zone = page_zone(page); | |
2430 | ||
2431 | if (isolated) { | |
2432 | struct lruvec *lruvec; | |
2433 | ||
2434 | lruvec = mem_cgroup_page_lruvec(page, zone); | |
2435 | VM_BUG_ON_PAGE(PageLRU(page), page); | |
2436 | SetPageLRU(page); | |
2437 | add_page_to_lru_list(page, lruvec, page_lru(page)); | |
2438 | } | |
2439 | spin_unlock_irq(&zone->lru_lock); | |
2440 | } | |
2441 | ||
00501b53 | 2442 | static void commit_charge(struct page *page, struct mem_cgroup *memcg, |
6abb5a86 | 2443 | bool lrucare) |
7a81b88c | 2444 | { |
0a31bc97 | 2445 | int isolated; |
9ce70c02 | 2446 | |
1306a85a | 2447 | VM_BUG_ON_PAGE(page->mem_cgroup, page); |
9ce70c02 HD |
2448 | |
2449 | /* | |
2450 | * In some cases, SwapCache and FUSE(splice_buf->radixtree), the page | |
2451 | * may already be on some other mem_cgroup's LRU. Take care of it. | |
2452 | */ | |
0a31bc97 JW |
2453 | if (lrucare) |
2454 | lock_page_lru(page, &isolated); | |
9ce70c02 | 2455 | |
0a31bc97 JW |
2456 | /* |
2457 | * Nobody should be changing or seriously looking at | |
1306a85a | 2458 | * page->mem_cgroup at this point: |
0a31bc97 JW |
2459 | * |
2460 | * - the page is uncharged | |
2461 | * | |
2462 | * - the page is off-LRU | |
2463 | * | |
2464 | * - an anonymous fault has exclusive page access, except for | |
2465 | * a locked page table | |
2466 | * | |
2467 | * - a page cache insertion, a swapin fault, or a migration | |
2468 | * have the page locked | |
2469 | */ | |
1306a85a | 2470 | page->mem_cgroup = memcg; |
9ce70c02 | 2471 | |
0a31bc97 JW |
2472 | if (lrucare) |
2473 | unlock_page_lru(page, isolated); | |
7a81b88c | 2474 | } |
66e1707b | 2475 | |
7ae1e1d0 | 2476 | #ifdef CONFIG_MEMCG_KMEM |
dbf22eb6 VD |
2477 | int memcg_charge_kmem(struct mem_cgroup *memcg, gfp_t gfp, |
2478 | unsigned long nr_pages) | |
7ae1e1d0 | 2479 | { |
3e32cb2e | 2480 | struct page_counter *counter; |
7ae1e1d0 | 2481 | int ret = 0; |
7ae1e1d0 | 2482 | |
3e32cb2e JW |
2483 | ret = page_counter_try_charge(&memcg->kmem, nr_pages, &counter); |
2484 | if (ret < 0) | |
7ae1e1d0 GC |
2485 | return ret; |
2486 | ||
3e32cb2e | 2487 | ret = try_charge(memcg, gfp, nr_pages); |
7ae1e1d0 GC |
2488 | if (ret == -EINTR) { |
2489 | /* | |
00501b53 JW |
2490 | * try_charge() chose to bypass to root due to OOM kill or |
2491 | * fatal signal. Since our only options are to either fail | |
2492 | * the allocation or charge it to this cgroup, do it as a | |
2493 | * temporary condition. But we can't fail. From a kmem/slab | |
2494 | * perspective, the cache has already been selected, by | |
2495 | * mem_cgroup_kmem_get_cache(), so it is too late to change | |
7ae1e1d0 GC |
2496 | * our minds. |
2497 | * | |
2498 | * This condition will only trigger if the task entered | |
00501b53 JW |
2499 | * memcg_charge_kmem in a sane state, but was OOM-killed |
2500 | * during try_charge() above. Tasks that were already dying | |
2501 | * when the allocation triggers should have been already | |
7ae1e1d0 GC |
2502 | * directed to the root cgroup in memcontrol.h |
2503 | */ | |
3e32cb2e | 2504 | page_counter_charge(&memcg->memory, nr_pages); |
7ae1e1d0 | 2505 | if (do_swap_account) |
3e32cb2e | 2506 | page_counter_charge(&memcg->memsw, nr_pages); |
e8ea14cc | 2507 | css_get_many(&memcg->css, nr_pages); |
7ae1e1d0 GC |
2508 | ret = 0; |
2509 | } else if (ret) | |
3e32cb2e | 2510 | page_counter_uncharge(&memcg->kmem, nr_pages); |
7ae1e1d0 GC |
2511 | |
2512 | return ret; | |
2513 | } | |
2514 | ||
dbf22eb6 | 2515 | void memcg_uncharge_kmem(struct mem_cgroup *memcg, unsigned long nr_pages) |
7ae1e1d0 | 2516 | { |
3e32cb2e | 2517 | page_counter_uncharge(&memcg->memory, nr_pages); |
7ae1e1d0 | 2518 | if (do_swap_account) |
3e32cb2e | 2519 | page_counter_uncharge(&memcg->memsw, nr_pages); |
7de37682 | 2520 | |
64f21993 | 2521 | page_counter_uncharge(&memcg->kmem, nr_pages); |
7de37682 | 2522 | |
e8ea14cc | 2523 | css_put_many(&memcg->css, nr_pages); |
7ae1e1d0 GC |
2524 | } |
2525 | ||
2633d7a0 GC |
2526 | /* |
2527 | * helper for acessing a memcg's index. It will be used as an index in the | |
2528 | * child cache array in kmem_cache, and also to derive its name. This function | |
2529 | * will return -1 when this is not a kmem-limited memcg. | |
2530 | */ | |
2531 | int memcg_cache_id(struct mem_cgroup *memcg) | |
2532 | { | |
2533 | return memcg ? memcg->kmemcg_id : -1; | |
2534 | } | |
2535 | ||
f3bb3043 | 2536 | static int memcg_alloc_cache_id(void) |
55007d84 | 2537 | { |
f3bb3043 VD |
2538 | int id, size; |
2539 | int err; | |
2540 | ||
2541 | id = ida_simple_get(&kmem_limited_groups, | |
2542 | 0, MEMCG_CACHES_MAX_SIZE, GFP_KERNEL); | |
2543 | if (id < 0) | |
2544 | return id; | |
55007d84 | 2545 | |
f3bb3043 VD |
2546 | if (id < memcg_limited_groups_array_size) |
2547 | return id; | |
2548 | ||
2549 | /* | |
2550 | * There's no space for the new id in memcg_caches arrays, | |
2551 | * so we have to grow them. | |
2552 | */ | |
2553 | ||
2554 | size = 2 * (id + 1); | |
55007d84 GC |
2555 | if (size < MEMCG_CACHES_MIN_SIZE) |
2556 | size = MEMCG_CACHES_MIN_SIZE; | |
2557 | else if (size > MEMCG_CACHES_MAX_SIZE) | |
2558 | size = MEMCG_CACHES_MAX_SIZE; | |
2559 | ||
f3bb3043 | 2560 | err = memcg_update_all_caches(size); |
f3bb3043 VD |
2561 | if (err) { |
2562 | ida_simple_remove(&kmem_limited_groups, id); | |
2563 | return err; | |
2564 | } | |
2565 | return id; | |
2566 | } | |
2567 | ||
2568 | static void memcg_free_cache_id(int id) | |
2569 | { | |
2570 | ida_simple_remove(&kmem_limited_groups, id); | |
55007d84 GC |
2571 | } |
2572 | ||
2573 | /* | |
2574 | * We should update the current array size iff all caches updates succeed. This | |
2575 | * can only be done from the slab side. The slab mutex needs to be held when | |
2576 | * calling this. | |
2577 | */ | |
2578 | void memcg_update_array_size(int num) | |
2579 | { | |
f3bb3043 | 2580 | memcg_limited_groups_array_size = num; |
55007d84 GC |
2581 | } |
2582 | ||
d5b3cf71 | 2583 | struct memcg_kmem_cache_create_work { |
5722d094 VD |
2584 | struct mem_cgroup *memcg; |
2585 | struct kmem_cache *cachep; | |
2586 | struct work_struct work; | |
2587 | }; | |
2588 | ||
d5b3cf71 | 2589 | static void memcg_kmem_cache_create_func(struct work_struct *w) |
d7f25f8a | 2590 | { |
d5b3cf71 VD |
2591 | struct memcg_kmem_cache_create_work *cw = |
2592 | container_of(w, struct memcg_kmem_cache_create_work, work); | |
5722d094 VD |
2593 | struct mem_cgroup *memcg = cw->memcg; |
2594 | struct kmem_cache *cachep = cw->cachep; | |
d7f25f8a | 2595 | |
d5b3cf71 | 2596 | memcg_create_kmem_cache(memcg, cachep); |
bd673145 | 2597 | |
5722d094 | 2598 | css_put(&memcg->css); |
d7f25f8a GC |
2599 | kfree(cw); |
2600 | } | |
2601 | ||
2602 | /* | |
2603 | * Enqueue the creation of a per-memcg kmem_cache. | |
d7f25f8a | 2604 | */ |
d5b3cf71 VD |
2605 | static void __memcg_schedule_kmem_cache_create(struct mem_cgroup *memcg, |
2606 | struct kmem_cache *cachep) | |
d7f25f8a | 2607 | { |
d5b3cf71 | 2608 | struct memcg_kmem_cache_create_work *cw; |
d7f25f8a | 2609 | |
776ed0f0 | 2610 | cw = kmalloc(sizeof(*cw), GFP_NOWAIT); |
8135be5a | 2611 | if (!cw) |
d7f25f8a | 2612 | return; |
8135be5a VD |
2613 | |
2614 | css_get(&memcg->css); | |
d7f25f8a GC |
2615 | |
2616 | cw->memcg = memcg; | |
2617 | cw->cachep = cachep; | |
d5b3cf71 | 2618 | INIT_WORK(&cw->work, memcg_kmem_cache_create_func); |
d7f25f8a | 2619 | |
d7f25f8a GC |
2620 | schedule_work(&cw->work); |
2621 | } | |
2622 | ||
d5b3cf71 VD |
2623 | static void memcg_schedule_kmem_cache_create(struct mem_cgroup *memcg, |
2624 | struct kmem_cache *cachep) | |
0e9d92f2 GC |
2625 | { |
2626 | /* | |
2627 | * We need to stop accounting when we kmalloc, because if the | |
2628 | * corresponding kmalloc cache is not yet created, the first allocation | |
d5b3cf71 | 2629 | * in __memcg_schedule_kmem_cache_create will recurse. |
0e9d92f2 GC |
2630 | * |
2631 | * However, it is better to enclose the whole function. Depending on | |
2632 | * the debugging options enabled, INIT_WORK(), for instance, can | |
2633 | * trigger an allocation. This too, will make us recurse. Because at | |
2634 | * this point we can't allow ourselves back into memcg_kmem_get_cache, | |
2635 | * the safest choice is to do it like this, wrapping the whole function. | |
2636 | */ | |
6f185c29 | 2637 | current->memcg_kmem_skip_account = 1; |
d5b3cf71 | 2638 | __memcg_schedule_kmem_cache_create(memcg, cachep); |
6f185c29 | 2639 | current->memcg_kmem_skip_account = 0; |
0e9d92f2 | 2640 | } |
c67a8a68 | 2641 | |
d7f25f8a GC |
2642 | /* |
2643 | * Return the kmem_cache we're supposed to use for a slab allocation. | |
2644 | * We try to use the current memcg's version of the cache. | |
2645 | * | |
2646 | * If the cache does not exist yet, if we are the first user of it, | |
2647 | * we either create it immediately, if possible, or create it asynchronously | |
2648 | * in a workqueue. | |
2649 | * In the latter case, we will let the current allocation go through with | |
2650 | * the original cache. | |
2651 | * | |
2652 | * Can't be called in interrupt context or from kernel threads. | |
2653 | * This function needs to be called with rcu_read_lock() held. | |
2654 | */ | |
056b7cce | 2655 | struct kmem_cache *__memcg_kmem_get_cache(struct kmem_cache *cachep) |
d7f25f8a GC |
2656 | { |
2657 | struct mem_cgroup *memcg; | |
959c8963 | 2658 | struct kmem_cache *memcg_cachep; |
d7f25f8a GC |
2659 | |
2660 | VM_BUG_ON(!cachep->memcg_params); | |
2661 | VM_BUG_ON(!cachep->memcg_params->is_root_cache); | |
2662 | ||
9d100c5e | 2663 | if (current->memcg_kmem_skip_account) |
0e9d92f2 GC |
2664 | return cachep; |
2665 | ||
8135be5a | 2666 | memcg = get_mem_cgroup_from_mm(current->mm); |
cf2b8fbf | 2667 | if (!memcg_kmem_is_active(memcg)) |
ca0dde97 | 2668 | goto out; |
d7f25f8a | 2669 | |
959c8963 | 2670 | memcg_cachep = cache_from_memcg_idx(cachep, memcg_cache_id(memcg)); |
8135be5a VD |
2671 | if (likely(memcg_cachep)) |
2672 | return memcg_cachep; | |
ca0dde97 LZ |
2673 | |
2674 | /* | |
2675 | * If we are in a safe context (can wait, and not in interrupt | |
2676 | * context), we could be be predictable and return right away. | |
2677 | * This would guarantee that the allocation being performed | |
2678 | * already belongs in the new cache. | |
2679 | * | |
2680 | * However, there are some clashes that can arrive from locking. | |
2681 | * For instance, because we acquire the slab_mutex while doing | |
776ed0f0 VD |
2682 | * memcg_create_kmem_cache, this means no further allocation |
2683 | * could happen with the slab_mutex held. So it's better to | |
2684 | * defer everything. | |
ca0dde97 | 2685 | */ |
d5b3cf71 | 2686 | memcg_schedule_kmem_cache_create(memcg, cachep); |
ca0dde97 | 2687 | out: |
8135be5a | 2688 | css_put(&memcg->css); |
ca0dde97 | 2689 | return cachep; |
d7f25f8a | 2690 | } |
d7f25f8a | 2691 | |
8135be5a VD |
2692 | void __memcg_kmem_put_cache(struct kmem_cache *cachep) |
2693 | { | |
2694 | if (!is_root_cache(cachep)) | |
2695 | css_put(&cachep->memcg_params->memcg->css); | |
2696 | } | |
2697 | ||
7ae1e1d0 GC |
2698 | /* |
2699 | * We need to verify if the allocation against current->mm->owner's memcg is | |
2700 | * possible for the given order. But the page is not allocated yet, so we'll | |
2701 | * need a further commit step to do the final arrangements. | |
2702 | * | |
2703 | * It is possible for the task to switch cgroups in this mean time, so at | |
2704 | * commit time, we can't rely on task conversion any longer. We'll then use | |
2705 | * the handle argument to return to the caller which cgroup we should commit | |
2706 | * against. We could also return the memcg directly and avoid the pointer | |
2707 | * passing, but a boolean return value gives better semantics considering | |
2708 | * the compiled-out case as well. | |
2709 | * | |
2710 | * Returning true means the allocation is possible. | |
2711 | */ | |
2712 | bool | |
2713 | __memcg_kmem_newpage_charge(gfp_t gfp, struct mem_cgroup **_memcg, int order) | |
2714 | { | |
2715 | struct mem_cgroup *memcg; | |
2716 | int ret; | |
2717 | ||
2718 | *_memcg = NULL; | |
6d42c232 | 2719 | |
df381975 | 2720 | memcg = get_mem_cgroup_from_mm(current->mm); |
7ae1e1d0 | 2721 | |
cf2b8fbf | 2722 | if (!memcg_kmem_is_active(memcg)) { |
7ae1e1d0 GC |
2723 | css_put(&memcg->css); |
2724 | return true; | |
2725 | } | |
2726 | ||
3e32cb2e | 2727 | ret = memcg_charge_kmem(memcg, gfp, 1 << order); |
7ae1e1d0 GC |
2728 | if (!ret) |
2729 | *_memcg = memcg; | |
7ae1e1d0 GC |
2730 | |
2731 | css_put(&memcg->css); | |
2732 | return (ret == 0); | |
2733 | } | |
2734 | ||
2735 | void __memcg_kmem_commit_charge(struct page *page, struct mem_cgroup *memcg, | |
2736 | int order) | |
2737 | { | |
7ae1e1d0 GC |
2738 | VM_BUG_ON(mem_cgroup_is_root(memcg)); |
2739 | ||
2740 | /* The page allocation failed. Revert */ | |
2741 | if (!page) { | |
3e32cb2e | 2742 | memcg_uncharge_kmem(memcg, 1 << order); |
7ae1e1d0 GC |
2743 | return; |
2744 | } | |
1306a85a | 2745 | page->mem_cgroup = memcg; |
7ae1e1d0 GC |
2746 | } |
2747 | ||
2748 | void __memcg_kmem_uncharge_pages(struct page *page, int order) | |
2749 | { | |
1306a85a | 2750 | struct mem_cgroup *memcg = page->mem_cgroup; |
7ae1e1d0 | 2751 | |
7ae1e1d0 GC |
2752 | if (!memcg) |
2753 | return; | |
2754 | ||
309381fe | 2755 | VM_BUG_ON_PAGE(mem_cgroup_is_root(memcg), page); |
29833315 | 2756 | |
3e32cb2e | 2757 | memcg_uncharge_kmem(memcg, 1 << order); |
1306a85a | 2758 | page->mem_cgroup = NULL; |
7ae1e1d0 GC |
2759 | } |
2760 | #endif /* CONFIG_MEMCG_KMEM */ | |
2761 | ||
ca3e0214 KH |
2762 | #ifdef CONFIG_TRANSPARENT_HUGEPAGE |
2763 | ||
ca3e0214 KH |
2764 | /* |
2765 | * Because tail pages are not marked as "used", set it. We're under | |
e94c8a9c KH |
2766 | * zone->lru_lock, 'splitting on pmd' and compound_lock. |
2767 | * charge/uncharge will be never happen and move_account() is done under | |
2768 | * compound_lock(), so we don't have to take care of races. | |
ca3e0214 | 2769 | */ |
e94c8a9c | 2770 | void mem_cgroup_split_huge_fixup(struct page *head) |
ca3e0214 | 2771 | { |
e94c8a9c | 2772 | int i; |
ca3e0214 | 2773 | |
3d37c4a9 KH |
2774 | if (mem_cgroup_disabled()) |
2775 | return; | |
b070e65c | 2776 | |
29833315 | 2777 | for (i = 1; i < HPAGE_PMD_NR; i++) |
1306a85a | 2778 | head[i].mem_cgroup = head->mem_cgroup; |
b9982f8d | 2779 | |
1306a85a | 2780 | __this_cpu_sub(head->mem_cgroup->stat->count[MEM_CGROUP_STAT_RSS_HUGE], |
b070e65c | 2781 | HPAGE_PMD_NR); |
ca3e0214 | 2782 | } |
12d27107 | 2783 | #endif /* CONFIG_TRANSPARENT_HUGEPAGE */ |
ca3e0214 | 2784 | |
f817ed48 | 2785 | /** |
de3638d9 | 2786 | * mem_cgroup_move_account - move account of the page |
5564e88b | 2787 | * @page: the page |
7ec99d62 | 2788 | * @nr_pages: number of regular pages (>1 for huge pages) |
f817ed48 KH |
2789 | * @from: mem_cgroup which the page is moved from. |
2790 | * @to: mem_cgroup which the page is moved to. @from != @to. | |
2791 | * | |
2792 | * The caller must confirm following. | |
08e552c6 | 2793 | * - page is not on LRU (isolate_page() is useful.) |
7ec99d62 | 2794 | * - compound_lock is held when nr_pages > 1 |
f817ed48 | 2795 | * |
2f3479b1 KH |
2796 | * This function doesn't do "charge" to new cgroup and doesn't do "uncharge" |
2797 | * from old cgroup. | |
f817ed48 | 2798 | */ |
7ec99d62 JW |
2799 | static int mem_cgroup_move_account(struct page *page, |
2800 | unsigned int nr_pages, | |
7ec99d62 | 2801 | struct mem_cgroup *from, |
2f3479b1 | 2802 | struct mem_cgroup *to) |
f817ed48 | 2803 | { |
de3638d9 JW |
2804 | unsigned long flags; |
2805 | int ret; | |
987eba66 | 2806 | |
f817ed48 | 2807 | VM_BUG_ON(from == to); |
309381fe | 2808 | VM_BUG_ON_PAGE(PageLRU(page), page); |
de3638d9 JW |
2809 | /* |
2810 | * The page is isolated from LRU. So, collapse function | |
2811 | * will not handle this page. But page splitting can happen. | |
2812 | * Do this check under compound_page_lock(). The caller should | |
2813 | * hold it. | |
2814 | */ | |
2815 | ret = -EBUSY; | |
7ec99d62 | 2816 | if (nr_pages > 1 && !PageTransHuge(page)) |
de3638d9 JW |
2817 | goto out; |
2818 | ||
0a31bc97 | 2819 | /* |
1306a85a | 2820 | * Prevent mem_cgroup_migrate() from looking at page->mem_cgroup |
0a31bc97 JW |
2821 | * of its source page while we change it: page migration takes |
2822 | * both pages off the LRU, but page cache replacement doesn't. | |
2823 | */ | |
2824 | if (!trylock_page(page)) | |
2825 | goto out; | |
de3638d9 JW |
2826 | |
2827 | ret = -EINVAL; | |
1306a85a | 2828 | if (page->mem_cgroup != from) |
0a31bc97 | 2829 | goto out_unlock; |
de3638d9 | 2830 | |
354a4783 | 2831 | spin_lock_irqsave(&from->move_lock, flags); |
f817ed48 | 2832 | |
0a31bc97 | 2833 | if (!PageAnon(page) && page_mapped(page)) { |
59d1d256 JW |
2834 | __this_cpu_sub(from->stat->count[MEM_CGROUP_STAT_FILE_MAPPED], |
2835 | nr_pages); | |
2836 | __this_cpu_add(to->stat->count[MEM_CGROUP_STAT_FILE_MAPPED], | |
2837 | nr_pages); | |
2838 | } | |
3ea67d06 | 2839 | |
59d1d256 JW |
2840 | if (PageWriteback(page)) { |
2841 | __this_cpu_sub(from->stat->count[MEM_CGROUP_STAT_WRITEBACK], | |
2842 | nr_pages); | |
2843 | __this_cpu_add(to->stat->count[MEM_CGROUP_STAT_WRITEBACK], | |
2844 | nr_pages); | |
2845 | } | |
3ea67d06 | 2846 | |
0a31bc97 | 2847 | /* |
1306a85a | 2848 | * It is safe to change page->mem_cgroup here because the page |
0a31bc97 JW |
2849 | * is referenced, charged, and isolated - we can't race with |
2850 | * uncharging, charging, migration, or LRU putback. | |
2851 | */ | |
d69b042f | 2852 | |
854ffa8d | 2853 | /* caller should have done css_get */ |
1306a85a | 2854 | page->mem_cgroup = to; |
354a4783 JW |
2855 | spin_unlock_irqrestore(&from->move_lock, flags); |
2856 | ||
de3638d9 | 2857 | ret = 0; |
0a31bc97 JW |
2858 | |
2859 | local_irq_disable(); | |
2860 | mem_cgroup_charge_statistics(to, page, nr_pages); | |
5564e88b | 2861 | memcg_check_events(to, page); |
0a31bc97 | 2862 | mem_cgroup_charge_statistics(from, page, -nr_pages); |
5564e88b | 2863 | memcg_check_events(from, page); |
0a31bc97 JW |
2864 | local_irq_enable(); |
2865 | out_unlock: | |
2866 | unlock_page(page); | |
de3638d9 | 2867 | out: |
f817ed48 KH |
2868 | return ret; |
2869 | } | |
2870 | ||
c255a458 | 2871 | #ifdef CONFIG_MEMCG_SWAP |
0a31bc97 JW |
2872 | static void mem_cgroup_swap_statistics(struct mem_cgroup *memcg, |
2873 | bool charge) | |
d13d1443 | 2874 | { |
0a31bc97 JW |
2875 | int val = (charge) ? 1 : -1; |
2876 | this_cpu_add(memcg->stat->count[MEM_CGROUP_STAT_SWAP], val); | |
d13d1443 | 2877 | } |
02491447 DN |
2878 | |
2879 | /** | |
2880 | * mem_cgroup_move_swap_account - move swap charge and swap_cgroup's record. | |
2881 | * @entry: swap entry to be moved | |
2882 | * @from: mem_cgroup which the entry is moved from | |
2883 | * @to: mem_cgroup which the entry is moved to | |
2884 | * | |
2885 | * It succeeds only when the swap_cgroup's record for this entry is the same | |
2886 | * as the mem_cgroup's id of @from. | |
2887 | * | |
2888 | * Returns 0 on success, -EINVAL on failure. | |
2889 | * | |
3e32cb2e | 2890 | * The caller must have charged to @to, IOW, called page_counter_charge() about |
02491447 DN |
2891 | * both res and memsw, and called css_get(). |
2892 | */ | |
2893 | static int mem_cgroup_move_swap_account(swp_entry_t entry, | |
e91cbb42 | 2894 | struct mem_cgroup *from, struct mem_cgroup *to) |
02491447 DN |
2895 | { |
2896 | unsigned short old_id, new_id; | |
2897 | ||
34c00c31 LZ |
2898 | old_id = mem_cgroup_id(from); |
2899 | new_id = mem_cgroup_id(to); | |
02491447 DN |
2900 | |
2901 | if (swap_cgroup_cmpxchg(entry, old_id, new_id) == old_id) { | |
02491447 | 2902 | mem_cgroup_swap_statistics(from, false); |
483c30b5 | 2903 | mem_cgroup_swap_statistics(to, true); |
02491447 DN |
2904 | return 0; |
2905 | } | |
2906 | return -EINVAL; | |
2907 | } | |
2908 | #else | |
2909 | static inline int mem_cgroup_move_swap_account(swp_entry_t entry, | |
e91cbb42 | 2910 | struct mem_cgroup *from, struct mem_cgroup *to) |
02491447 DN |
2911 | { |
2912 | return -EINVAL; | |
2913 | } | |
8c7c6e34 | 2914 | #endif |
d13d1443 | 2915 | |
3e32cb2e | 2916 | static DEFINE_MUTEX(memcg_limit_mutex); |
f212ad7c | 2917 | |
d38d2a75 | 2918 | static int mem_cgroup_resize_limit(struct mem_cgroup *memcg, |
3e32cb2e | 2919 | unsigned long limit) |
628f4235 | 2920 | { |
3e32cb2e JW |
2921 | unsigned long curusage; |
2922 | unsigned long oldusage; | |
2923 | bool enlarge = false; | |
81d39c20 | 2924 | int retry_count; |
3e32cb2e | 2925 | int ret; |
81d39c20 KH |
2926 | |
2927 | /* | |
2928 | * For keeping hierarchical_reclaim simple, how long we should retry | |
2929 | * is depends on callers. We set our retry-count to be function | |
2930 | * of # of children which we should visit in this loop. | |
2931 | */ | |
3e32cb2e JW |
2932 | retry_count = MEM_CGROUP_RECLAIM_RETRIES * |
2933 | mem_cgroup_count_children(memcg); | |
81d39c20 | 2934 | |
3e32cb2e | 2935 | oldusage = page_counter_read(&memcg->memory); |
628f4235 | 2936 | |
3e32cb2e | 2937 | do { |
628f4235 KH |
2938 | if (signal_pending(current)) { |
2939 | ret = -EINTR; | |
2940 | break; | |
2941 | } | |
3e32cb2e JW |
2942 | |
2943 | mutex_lock(&memcg_limit_mutex); | |
2944 | if (limit > memcg->memsw.limit) { | |
2945 | mutex_unlock(&memcg_limit_mutex); | |
8c7c6e34 | 2946 | ret = -EINVAL; |
628f4235 KH |
2947 | break; |
2948 | } | |
3e32cb2e JW |
2949 | if (limit > memcg->memory.limit) |
2950 | enlarge = true; | |
2951 | ret = page_counter_limit(&memcg->memory, limit); | |
2952 | mutex_unlock(&memcg_limit_mutex); | |
8c7c6e34 KH |
2953 | |
2954 | if (!ret) | |
2955 | break; | |
2956 | ||
b70a2a21 JW |
2957 | try_to_free_mem_cgroup_pages(memcg, 1, GFP_KERNEL, true); |
2958 | ||
3e32cb2e | 2959 | curusage = page_counter_read(&memcg->memory); |
81d39c20 | 2960 | /* Usage is reduced ? */ |
f894ffa8 | 2961 | if (curusage >= oldusage) |
81d39c20 KH |
2962 | retry_count--; |
2963 | else | |
2964 | oldusage = curusage; | |
3e32cb2e JW |
2965 | } while (retry_count); |
2966 | ||
3c11ecf4 KH |
2967 | if (!ret && enlarge) |
2968 | memcg_oom_recover(memcg); | |
14797e23 | 2969 | |
8c7c6e34 KH |
2970 | return ret; |
2971 | } | |
2972 | ||
338c8431 | 2973 | static int mem_cgroup_resize_memsw_limit(struct mem_cgroup *memcg, |
3e32cb2e | 2974 | unsigned long limit) |
8c7c6e34 | 2975 | { |
3e32cb2e JW |
2976 | unsigned long curusage; |
2977 | unsigned long oldusage; | |
2978 | bool enlarge = false; | |
81d39c20 | 2979 | int retry_count; |
3e32cb2e | 2980 | int ret; |
8c7c6e34 | 2981 | |
81d39c20 | 2982 | /* see mem_cgroup_resize_res_limit */ |
3e32cb2e JW |
2983 | retry_count = MEM_CGROUP_RECLAIM_RETRIES * |
2984 | mem_cgroup_count_children(memcg); | |
2985 | ||
2986 | oldusage = page_counter_read(&memcg->memsw); | |
2987 | ||
2988 | do { | |
8c7c6e34 KH |
2989 | if (signal_pending(current)) { |
2990 | ret = -EINTR; | |
2991 | break; | |
2992 | } | |
3e32cb2e JW |
2993 | |
2994 | mutex_lock(&memcg_limit_mutex); | |
2995 | if (limit < memcg->memory.limit) { | |
2996 | mutex_unlock(&memcg_limit_mutex); | |
8c7c6e34 | 2997 | ret = -EINVAL; |
8c7c6e34 KH |
2998 | break; |
2999 | } | |
3e32cb2e JW |
3000 | if (limit > memcg->memsw.limit) |
3001 | enlarge = true; | |
3002 | ret = page_counter_limit(&memcg->memsw, limit); | |
3003 | mutex_unlock(&memcg_limit_mutex); | |
8c7c6e34 KH |
3004 | |
3005 | if (!ret) | |
3006 | break; | |
3007 | ||
b70a2a21 JW |
3008 | try_to_free_mem_cgroup_pages(memcg, 1, GFP_KERNEL, false); |
3009 | ||
3e32cb2e | 3010 | curusage = page_counter_read(&memcg->memsw); |
81d39c20 | 3011 | /* Usage is reduced ? */ |
8c7c6e34 | 3012 | if (curusage >= oldusage) |
628f4235 | 3013 | retry_count--; |
81d39c20 KH |
3014 | else |
3015 | oldusage = curusage; | |
3e32cb2e JW |
3016 | } while (retry_count); |
3017 | ||
3c11ecf4 KH |
3018 | if (!ret && enlarge) |
3019 | memcg_oom_recover(memcg); | |
3e32cb2e | 3020 | |
628f4235 KH |
3021 | return ret; |
3022 | } | |
3023 | ||
0608f43d AM |
3024 | unsigned long mem_cgroup_soft_limit_reclaim(struct zone *zone, int order, |
3025 | gfp_t gfp_mask, | |
3026 | unsigned long *total_scanned) | |
3027 | { | |
3028 | unsigned long nr_reclaimed = 0; | |
3029 | struct mem_cgroup_per_zone *mz, *next_mz = NULL; | |
3030 | unsigned long reclaimed; | |
3031 | int loop = 0; | |
3032 | struct mem_cgroup_tree_per_zone *mctz; | |
3e32cb2e | 3033 | unsigned long excess; |
0608f43d AM |
3034 | unsigned long nr_scanned; |
3035 | ||
3036 | if (order > 0) | |
3037 | return 0; | |
3038 | ||
3039 | mctz = soft_limit_tree_node_zone(zone_to_nid(zone), zone_idx(zone)); | |
3040 | /* | |
3041 | * This loop can run a while, specially if mem_cgroup's continuously | |
3042 | * keep exceeding their soft limit and putting the system under | |
3043 | * pressure | |
3044 | */ | |
3045 | do { | |
3046 | if (next_mz) | |
3047 | mz = next_mz; | |
3048 | else | |
3049 | mz = mem_cgroup_largest_soft_limit_node(mctz); | |
3050 | if (!mz) | |
3051 | break; | |
3052 | ||
3053 | nr_scanned = 0; | |
3054 | reclaimed = mem_cgroup_soft_reclaim(mz->memcg, zone, | |
3055 | gfp_mask, &nr_scanned); | |
3056 | nr_reclaimed += reclaimed; | |
3057 | *total_scanned += nr_scanned; | |
0a31bc97 | 3058 | spin_lock_irq(&mctz->lock); |
bc2f2e7f | 3059 | __mem_cgroup_remove_exceeded(mz, mctz); |
0608f43d AM |
3060 | |
3061 | /* | |
3062 | * If we failed to reclaim anything from this memory cgroup | |
3063 | * it is time to move on to the next cgroup | |
3064 | */ | |
3065 | next_mz = NULL; | |
bc2f2e7f VD |
3066 | if (!reclaimed) |
3067 | next_mz = __mem_cgroup_largest_soft_limit_node(mctz); | |
3068 | ||
3e32cb2e | 3069 | excess = soft_limit_excess(mz->memcg); |
0608f43d AM |
3070 | /* |
3071 | * One school of thought says that we should not add | |
3072 | * back the node to the tree if reclaim returns 0. | |
3073 | * But our reclaim could return 0, simply because due | |
3074 | * to priority we are exposing a smaller subset of | |
3075 | * memory to reclaim from. Consider this as a longer | |
3076 | * term TODO. | |
3077 | */ | |
3078 | /* If excess == 0, no tree ops */ | |
cf2c8127 | 3079 | __mem_cgroup_insert_exceeded(mz, mctz, excess); |
0a31bc97 | 3080 | spin_unlock_irq(&mctz->lock); |
0608f43d AM |
3081 | css_put(&mz->memcg->css); |
3082 | loop++; | |
3083 | /* | |
3084 | * Could not reclaim anything and there are no more | |
3085 | * mem cgroups to try or we seem to be looping without | |
3086 | * reclaiming anything. | |
3087 | */ | |
3088 | if (!nr_reclaimed && | |
3089 | (next_mz == NULL || | |
3090 | loop > MEM_CGROUP_MAX_SOFT_LIMIT_RECLAIM_LOOPS)) | |
3091 | break; | |
3092 | } while (!nr_reclaimed); | |
3093 | if (next_mz) | |
3094 | css_put(&next_mz->memcg->css); | |
3095 | return nr_reclaimed; | |
3096 | } | |
3097 | ||
ea280e7b TH |
3098 | /* |
3099 | * Test whether @memcg has children, dead or alive. Note that this | |
3100 | * function doesn't care whether @memcg has use_hierarchy enabled and | |
3101 | * returns %true if there are child csses according to the cgroup | |
3102 | * hierarchy. Testing use_hierarchy is the caller's responsiblity. | |
3103 | */ | |
b5f99b53 GC |
3104 | static inline bool memcg_has_children(struct mem_cgroup *memcg) |
3105 | { | |
ea280e7b TH |
3106 | bool ret; |
3107 | ||
696ac172 | 3108 | /* |
ea280e7b TH |
3109 | * The lock does not prevent addition or deletion of children, but |
3110 | * it prevents a new child from being initialized based on this | |
3111 | * parent in css_online(), so it's enough to decide whether | |
3112 | * hierarchically inherited attributes can still be changed or not. | |
696ac172 | 3113 | */ |
ea280e7b TH |
3114 | lockdep_assert_held(&memcg_create_mutex); |
3115 | ||
3116 | rcu_read_lock(); | |
3117 | ret = css_next_child(NULL, &memcg->css); | |
3118 | rcu_read_unlock(); | |
3119 | return ret; | |
b5f99b53 GC |
3120 | } |
3121 | ||
c26251f9 MH |
3122 | /* |
3123 | * Reclaims as many pages from the given memcg as possible and moves | |
3124 | * the rest to the parent. | |
3125 | * | |
3126 | * Caller is responsible for holding css reference for memcg. | |
3127 | */ | |
3128 | static int mem_cgroup_force_empty(struct mem_cgroup *memcg) | |
3129 | { | |
3130 | int nr_retries = MEM_CGROUP_RECLAIM_RETRIES; | |
c26251f9 | 3131 | |
c1e862c1 KH |
3132 | /* we call try-to-free pages for make this cgroup empty */ |
3133 | lru_add_drain_all(); | |
f817ed48 | 3134 | /* try to free all pages in this cgroup */ |
3e32cb2e | 3135 | while (nr_retries && page_counter_read(&memcg->memory)) { |
f817ed48 | 3136 | int progress; |
c1e862c1 | 3137 | |
c26251f9 MH |
3138 | if (signal_pending(current)) |
3139 | return -EINTR; | |
3140 | ||
b70a2a21 JW |
3141 | progress = try_to_free_mem_cgroup_pages(memcg, 1, |
3142 | GFP_KERNEL, true); | |
c1e862c1 | 3143 | if (!progress) { |
f817ed48 | 3144 | nr_retries--; |
c1e862c1 | 3145 | /* maybe some writeback is necessary */ |
8aa7e847 | 3146 | congestion_wait(BLK_RW_ASYNC, HZ/10); |
c1e862c1 | 3147 | } |
f817ed48 KH |
3148 | |
3149 | } | |
ab5196c2 MH |
3150 | |
3151 | return 0; | |
cc847582 KH |
3152 | } |
3153 | ||
6770c64e TH |
3154 | static ssize_t mem_cgroup_force_empty_write(struct kernfs_open_file *of, |
3155 | char *buf, size_t nbytes, | |
3156 | loff_t off) | |
c1e862c1 | 3157 | { |
6770c64e | 3158 | struct mem_cgroup *memcg = mem_cgroup_from_css(of_css(of)); |
c26251f9 | 3159 | |
d8423011 MH |
3160 | if (mem_cgroup_is_root(memcg)) |
3161 | return -EINVAL; | |
6770c64e | 3162 | return mem_cgroup_force_empty(memcg) ?: nbytes; |
c1e862c1 KH |
3163 | } |
3164 | ||
182446d0 TH |
3165 | static u64 mem_cgroup_hierarchy_read(struct cgroup_subsys_state *css, |
3166 | struct cftype *cft) | |
18f59ea7 | 3167 | { |
182446d0 | 3168 | return mem_cgroup_from_css(css)->use_hierarchy; |
18f59ea7 BS |
3169 | } |
3170 | ||
182446d0 TH |
3171 | static int mem_cgroup_hierarchy_write(struct cgroup_subsys_state *css, |
3172 | struct cftype *cft, u64 val) | |
18f59ea7 BS |
3173 | { |
3174 | int retval = 0; | |
182446d0 | 3175 | struct mem_cgroup *memcg = mem_cgroup_from_css(css); |
5c9d535b | 3176 | struct mem_cgroup *parent_memcg = mem_cgroup_from_css(memcg->css.parent); |
18f59ea7 | 3177 | |
0999821b | 3178 | mutex_lock(&memcg_create_mutex); |
567fb435 GC |
3179 | |
3180 | if (memcg->use_hierarchy == val) | |
3181 | goto out; | |
3182 | ||
18f59ea7 | 3183 | /* |
af901ca1 | 3184 | * If parent's use_hierarchy is set, we can't make any modifications |
18f59ea7 BS |
3185 | * in the child subtrees. If it is unset, then the change can |
3186 | * occur, provided the current cgroup has no children. | |
3187 | * | |
3188 | * For the root cgroup, parent_mem is NULL, we allow value to be | |
3189 | * set if there are no children. | |
3190 | */ | |
c0ff4b85 | 3191 | if ((!parent_memcg || !parent_memcg->use_hierarchy) && |
18f59ea7 | 3192 | (val == 1 || val == 0)) { |
ea280e7b | 3193 | if (!memcg_has_children(memcg)) |
c0ff4b85 | 3194 | memcg->use_hierarchy = val; |
18f59ea7 BS |
3195 | else |
3196 | retval = -EBUSY; | |
3197 | } else | |
3198 | retval = -EINVAL; | |
567fb435 GC |
3199 | |
3200 | out: | |
0999821b | 3201 | mutex_unlock(&memcg_create_mutex); |
18f59ea7 BS |
3202 | |
3203 | return retval; | |
3204 | } | |
3205 | ||
3e32cb2e JW |
3206 | static unsigned long tree_stat(struct mem_cgroup *memcg, |
3207 | enum mem_cgroup_stat_index idx) | |
ce00a967 JW |
3208 | { |
3209 | struct mem_cgroup *iter; | |
3210 | long val = 0; | |
3211 | ||
3212 | /* Per-cpu values can be negative, use a signed accumulator */ | |
3213 | for_each_mem_cgroup_tree(iter, memcg) | |
3214 | val += mem_cgroup_read_stat(iter, idx); | |
3215 | ||
3216 | if (val < 0) /* race ? */ | |
3217 | val = 0; | |
3218 | return val; | |
3219 | } | |
3220 | ||
3221 | static inline u64 mem_cgroup_usage(struct mem_cgroup *memcg, bool swap) | |
3222 | { | |
3223 | u64 val; | |
3224 | ||
3e32cb2e JW |
3225 | if (mem_cgroup_is_root(memcg)) { |
3226 | val = tree_stat(memcg, MEM_CGROUP_STAT_CACHE); | |
3227 | val += tree_stat(memcg, MEM_CGROUP_STAT_RSS); | |
3228 | if (swap) | |
3229 | val += tree_stat(memcg, MEM_CGROUP_STAT_SWAP); | |
3230 | } else { | |
ce00a967 | 3231 | if (!swap) |
3e32cb2e | 3232 | val = page_counter_read(&memcg->memory); |
ce00a967 | 3233 | else |
3e32cb2e | 3234 | val = page_counter_read(&memcg->memsw); |
ce00a967 | 3235 | } |
ce00a967 JW |
3236 | return val << PAGE_SHIFT; |
3237 | } | |
3238 | ||
3e32cb2e JW |
3239 | enum { |
3240 | RES_USAGE, | |
3241 | RES_LIMIT, | |
3242 | RES_MAX_USAGE, | |
3243 | RES_FAILCNT, | |
3244 | RES_SOFT_LIMIT, | |
3245 | }; | |
ce00a967 | 3246 | |
791badbd | 3247 | static u64 mem_cgroup_read_u64(struct cgroup_subsys_state *css, |
05b84301 | 3248 | struct cftype *cft) |
8cdea7c0 | 3249 | { |
182446d0 | 3250 | struct mem_cgroup *memcg = mem_cgroup_from_css(css); |
3e32cb2e | 3251 | struct page_counter *counter; |
af36f906 | 3252 | |
3e32cb2e | 3253 | switch (MEMFILE_TYPE(cft->private)) { |
8c7c6e34 | 3254 | case _MEM: |
3e32cb2e JW |
3255 | counter = &memcg->memory; |
3256 | break; | |
8c7c6e34 | 3257 | case _MEMSWAP: |
3e32cb2e JW |
3258 | counter = &memcg->memsw; |
3259 | break; | |
510fc4e1 | 3260 | case _KMEM: |
3e32cb2e | 3261 | counter = &memcg->kmem; |
510fc4e1 | 3262 | break; |
8c7c6e34 KH |
3263 | default: |
3264 | BUG(); | |
8c7c6e34 | 3265 | } |
3e32cb2e JW |
3266 | |
3267 | switch (MEMFILE_ATTR(cft->private)) { | |
3268 | case RES_USAGE: | |
3269 | if (counter == &memcg->memory) | |
3270 | return mem_cgroup_usage(memcg, false); | |
3271 | if (counter == &memcg->memsw) | |
3272 | return mem_cgroup_usage(memcg, true); | |
3273 | return (u64)page_counter_read(counter) * PAGE_SIZE; | |
3274 | case RES_LIMIT: | |
3275 | return (u64)counter->limit * PAGE_SIZE; | |
3276 | case RES_MAX_USAGE: | |
3277 | return (u64)counter->watermark * PAGE_SIZE; | |
3278 | case RES_FAILCNT: | |
3279 | return counter->failcnt; | |
3280 | case RES_SOFT_LIMIT: | |
3281 | return (u64)memcg->soft_limit * PAGE_SIZE; | |
3282 | default: | |
3283 | BUG(); | |
3284 | } | |
8cdea7c0 | 3285 | } |
510fc4e1 | 3286 | |
510fc4e1 | 3287 | #ifdef CONFIG_MEMCG_KMEM |
8c0145b6 VD |
3288 | static int memcg_activate_kmem(struct mem_cgroup *memcg, |
3289 | unsigned long nr_pages) | |
d6441637 VD |
3290 | { |
3291 | int err = 0; | |
3292 | int memcg_id; | |
3293 | ||
3294 | if (memcg_kmem_is_active(memcg)) | |
3295 | return 0; | |
3296 | ||
510fc4e1 GC |
3297 | /* |
3298 | * For simplicity, we won't allow this to be disabled. It also can't | |
3299 | * be changed if the cgroup has children already, or if tasks had | |
3300 | * already joined. | |
3301 | * | |
3302 | * If tasks join before we set the limit, a person looking at | |
3303 | * kmem.usage_in_bytes will have no way to determine when it took | |
3304 | * place, which makes the value quite meaningless. | |
3305 | * | |
3306 | * After it first became limited, changes in the value of the limit are | |
3307 | * of course permitted. | |
510fc4e1 | 3308 | */ |
0999821b | 3309 | mutex_lock(&memcg_create_mutex); |
ea280e7b TH |
3310 | if (cgroup_has_tasks(memcg->css.cgroup) || |
3311 | (memcg->use_hierarchy && memcg_has_children(memcg))) | |
d6441637 VD |
3312 | err = -EBUSY; |
3313 | mutex_unlock(&memcg_create_mutex); | |
3314 | if (err) | |
3315 | goto out; | |
510fc4e1 | 3316 | |
f3bb3043 | 3317 | memcg_id = memcg_alloc_cache_id(); |
d6441637 VD |
3318 | if (memcg_id < 0) { |
3319 | err = memcg_id; | |
3320 | goto out; | |
3321 | } | |
3322 | ||
d6441637 | 3323 | /* |
900a38f0 VD |
3324 | * We couldn't have accounted to this cgroup, because it hasn't got |
3325 | * activated yet, so this should succeed. | |
d6441637 | 3326 | */ |
3e32cb2e | 3327 | err = page_counter_limit(&memcg->kmem, nr_pages); |
d6441637 VD |
3328 | VM_BUG_ON(err); |
3329 | ||
3330 | static_key_slow_inc(&memcg_kmem_enabled_key); | |
3331 | /* | |
900a38f0 VD |
3332 | * A memory cgroup is considered kmem-active as soon as it gets |
3333 | * kmemcg_id. Setting the id after enabling static branching will | |
d6441637 VD |
3334 | * guarantee no one starts accounting before all call sites are |
3335 | * patched. | |
3336 | */ | |
900a38f0 | 3337 | memcg->kmemcg_id = memcg_id; |
510fc4e1 | 3338 | out: |
d6441637 | 3339 | return err; |
d6441637 VD |
3340 | } |
3341 | ||
d6441637 | 3342 | static int memcg_update_kmem_limit(struct mem_cgroup *memcg, |
3e32cb2e | 3343 | unsigned long limit) |
d6441637 VD |
3344 | { |
3345 | int ret; | |
3346 | ||
3e32cb2e | 3347 | mutex_lock(&memcg_limit_mutex); |
d6441637 | 3348 | if (!memcg_kmem_is_active(memcg)) |
3e32cb2e | 3349 | ret = memcg_activate_kmem(memcg, limit); |
d6441637 | 3350 | else |
3e32cb2e JW |
3351 | ret = page_counter_limit(&memcg->kmem, limit); |
3352 | mutex_unlock(&memcg_limit_mutex); | |
510fc4e1 GC |
3353 | return ret; |
3354 | } | |
3355 | ||
55007d84 | 3356 | static int memcg_propagate_kmem(struct mem_cgroup *memcg) |
510fc4e1 | 3357 | { |
55007d84 | 3358 | int ret = 0; |
510fc4e1 | 3359 | struct mem_cgroup *parent = parent_mem_cgroup(memcg); |
55007d84 | 3360 | |
d6441637 VD |
3361 | if (!parent) |
3362 | return 0; | |
55007d84 | 3363 | |
8c0145b6 | 3364 | mutex_lock(&memcg_limit_mutex); |
55007d84 | 3365 | /* |
d6441637 VD |
3366 | * If the parent cgroup is not kmem-active now, it cannot be activated |
3367 | * after this point, because it has at least one child already. | |
55007d84 | 3368 | */ |
d6441637 | 3369 | if (memcg_kmem_is_active(parent)) |
8c0145b6 VD |
3370 | ret = memcg_activate_kmem(memcg, PAGE_COUNTER_MAX); |
3371 | mutex_unlock(&memcg_limit_mutex); | |
55007d84 | 3372 | return ret; |
510fc4e1 | 3373 | } |
d6441637 VD |
3374 | #else |
3375 | static int memcg_update_kmem_limit(struct mem_cgroup *memcg, | |
3e32cb2e | 3376 | unsigned long limit) |
d6441637 VD |
3377 | { |
3378 | return -EINVAL; | |
3379 | } | |
6d043990 | 3380 | #endif /* CONFIG_MEMCG_KMEM */ |
510fc4e1 | 3381 | |
628f4235 KH |
3382 | /* |
3383 | * The user of this function is... | |
3384 | * RES_LIMIT. | |
3385 | */ | |
451af504 TH |
3386 | static ssize_t mem_cgroup_write(struct kernfs_open_file *of, |
3387 | char *buf, size_t nbytes, loff_t off) | |
8cdea7c0 | 3388 | { |
451af504 | 3389 | struct mem_cgroup *memcg = mem_cgroup_from_css(of_css(of)); |
3e32cb2e | 3390 | unsigned long nr_pages; |
628f4235 KH |
3391 | int ret; |
3392 | ||
451af504 | 3393 | buf = strstrip(buf); |
650c5e56 | 3394 | ret = page_counter_memparse(buf, "-1", &nr_pages); |
3e32cb2e JW |
3395 | if (ret) |
3396 | return ret; | |
af36f906 | 3397 | |
3e32cb2e | 3398 | switch (MEMFILE_ATTR(of_cft(of)->private)) { |
628f4235 | 3399 | case RES_LIMIT: |
4b3bde4c BS |
3400 | if (mem_cgroup_is_root(memcg)) { /* Can't set limit on root */ |
3401 | ret = -EINVAL; | |
3402 | break; | |
3403 | } | |
3e32cb2e JW |
3404 | switch (MEMFILE_TYPE(of_cft(of)->private)) { |
3405 | case _MEM: | |
3406 | ret = mem_cgroup_resize_limit(memcg, nr_pages); | |
8c7c6e34 | 3407 | break; |
3e32cb2e JW |
3408 | case _MEMSWAP: |
3409 | ret = mem_cgroup_resize_memsw_limit(memcg, nr_pages); | |
296c81d8 | 3410 | break; |
3e32cb2e JW |
3411 | case _KMEM: |
3412 | ret = memcg_update_kmem_limit(memcg, nr_pages); | |
3413 | break; | |
3414 | } | |
296c81d8 | 3415 | break; |
3e32cb2e JW |
3416 | case RES_SOFT_LIMIT: |
3417 | memcg->soft_limit = nr_pages; | |
3418 | ret = 0; | |
628f4235 KH |
3419 | break; |
3420 | } | |
451af504 | 3421 | return ret ?: nbytes; |
8cdea7c0 BS |
3422 | } |
3423 | ||
6770c64e TH |
3424 | static ssize_t mem_cgroup_reset(struct kernfs_open_file *of, char *buf, |
3425 | size_t nbytes, loff_t off) | |
c84872e1 | 3426 | { |
6770c64e | 3427 | struct mem_cgroup *memcg = mem_cgroup_from_css(of_css(of)); |
3e32cb2e | 3428 | struct page_counter *counter; |
c84872e1 | 3429 | |
3e32cb2e JW |
3430 | switch (MEMFILE_TYPE(of_cft(of)->private)) { |
3431 | case _MEM: | |
3432 | counter = &memcg->memory; | |
3433 | break; | |
3434 | case _MEMSWAP: | |
3435 | counter = &memcg->memsw; | |
3436 | break; | |
3437 | case _KMEM: | |
3438 | counter = &memcg->kmem; | |
3439 | break; | |
3440 | default: | |
3441 | BUG(); | |
3442 | } | |
af36f906 | 3443 | |
3e32cb2e | 3444 | switch (MEMFILE_ATTR(of_cft(of)->private)) { |
29f2a4da | 3445 | case RES_MAX_USAGE: |
3e32cb2e | 3446 | page_counter_reset_watermark(counter); |
29f2a4da PE |
3447 | break; |
3448 | case RES_FAILCNT: | |
3e32cb2e | 3449 | counter->failcnt = 0; |
29f2a4da | 3450 | break; |
3e32cb2e JW |
3451 | default: |
3452 | BUG(); | |
29f2a4da | 3453 | } |
f64c3f54 | 3454 | |
6770c64e | 3455 | return nbytes; |
c84872e1 PE |
3456 | } |
3457 | ||
182446d0 | 3458 | static u64 mem_cgroup_move_charge_read(struct cgroup_subsys_state *css, |
7dc74be0 DN |
3459 | struct cftype *cft) |
3460 | { | |
182446d0 | 3461 | return mem_cgroup_from_css(css)->move_charge_at_immigrate; |
7dc74be0 DN |
3462 | } |
3463 | ||
02491447 | 3464 | #ifdef CONFIG_MMU |
182446d0 | 3465 | static int mem_cgroup_move_charge_write(struct cgroup_subsys_state *css, |
7dc74be0 DN |
3466 | struct cftype *cft, u64 val) |
3467 | { | |
182446d0 | 3468 | struct mem_cgroup *memcg = mem_cgroup_from_css(css); |
7dc74be0 | 3469 | |
1dfab5ab | 3470 | if (val & ~MOVE_MASK) |
7dc74be0 | 3471 | return -EINVAL; |
ee5e8472 | 3472 | |
7dc74be0 | 3473 | /* |
ee5e8472 GC |
3474 | * No kind of locking is needed in here, because ->can_attach() will |
3475 | * check this value once in the beginning of the process, and then carry | |
3476 | * on with stale data. This means that changes to this value will only | |
3477 | * affect task migrations starting after the change. | |
7dc74be0 | 3478 | */ |
c0ff4b85 | 3479 | memcg->move_charge_at_immigrate = val; |
7dc74be0 DN |
3480 | return 0; |
3481 | } | |
02491447 | 3482 | #else |
182446d0 | 3483 | static int mem_cgroup_move_charge_write(struct cgroup_subsys_state *css, |
02491447 DN |
3484 | struct cftype *cft, u64 val) |
3485 | { | |
3486 | return -ENOSYS; | |
3487 | } | |
3488 | #endif | |
7dc74be0 | 3489 | |
406eb0c9 | 3490 | #ifdef CONFIG_NUMA |
2da8ca82 | 3491 | static int memcg_numa_stat_show(struct seq_file *m, void *v) |
406eb0c9 | 3492 | { |
25485de6 GT |
3493 | struct numa_stat { |
3494 | const char *name; | |
3495 | unsigned int lru_mask; | |
3496 | }; | |
3497 | ||
3498 | static const struct numa_stat stats[] = { | |
3499 | { "total", LRU_ALL }, | |
3500 | { "file", LRU_ALL_FILE }, | |
3501 | { "anon", LRU_ALL_ANON }, | |
3502 | { "unevictable", BIT(LRU_UNEVICTABLE) }, | |
3503 | }; | |
3504 | const struct numa_stat *stat; | |
406eb0c9 | 3505 | int nid; |
25485de6 | 3506 | unsigned long nr; |
2da8ca82 | 3507 | struct mem_cgroup *memcg = mem_cgroup_from_css(seq_css(m)); |
406eb0c9 | 3508 | |
25485de6 GT |
3509 | for (stat = stats; stat < stats + ARRAY_SIZE(stats); stat++) { |
3510 | nr = mem_cgroup_nr_lru_pages(memcg, stat->lru_mask); | |
3511 | seq_printf(m, "%s=%lu", stat->name, nr); | |
3512 | for_each_node_state(nid, N_MEMORY) { | |
3513 | nr = mem_cgroup_node_nr_lru_pages(memcg, nid, | |
3514 | stat->lru_mask); | |
3515 | seq_printf(m, " N%d=%lu", nid, nr); | |
3516 | } | |
3517 | seq_putc(m, '\n'); | |
406eb0c9 | 3518 | } |
406eb0c9 | 3519 | |
071aee13 YH |
3520 | for (stat = stats; stat < stats + ARRAY_SIZE(stats); stat++) { |
3521 | struct mem_cgroup *iter; | |
3522 | ||
3523 | nr = 0; | |
3524 | for_each_mem_cgroup_tree(iter, memcg) | |
3525 | nr += mem_cgroup_nr_lru_pages(iter, stat->lru_mask); | |
3526 | seq_printf(m, "hierarchical_%s=%lu", stat->name, nr); | |
3527 | for_each_node_state(nid, N_MEMORY) { | |
3528 | nr = 0; | |
3529 | for_each_mem_cgroup_tree(iter, memcg) | |
3530 | nr += mem_cgroup_node_nr_lru_pages( | |
3531 | iter, nid, stat->lru_mask); | |
3532 | seq_printf(m, " N%d=%lu", nid, nr); | |
3533 | } | |
3534 | seq_putc(m, '\n'); | |
406eb0c9 | 3535 | } |
406eb0c9 | 3536 | |
406eb0c9 YH |
3537 | return 0; |
3538 | } | |
3539 | #endif /* CONFIG_NUMA */ | |
3540 | ||
2da8ca82 | 3541 | static int memcg_stat_show(struct seq_file *m, void *v) |
d2ceb9b7 | 3542 | { |
2da8ca82 | 3543 | struct mem_cgroup *memcg = mem_cgroup_from_css(seq_css(m)); |
3e32cb2e | 3544 | unsigned long memory, memsw; |
af7c4b0e JW |
3545 | struct mem_cgroup *mi; |
3546 | unsigned int i; | |
406eb0c9 | 3547 | |
0ca44b14 GT |
3548 | BUILD_BUG_ON(ARRAY_SIZE(mem_cgroup_stat_names) != |
3549 | MEM_CGROUP_STAT_NSTATS); | |
3550 | BUILD_BUG_ON(ARRAY_SIZE(mem_cgroup_events_names) != | |
3551 | MEM_CGROUP_EVENTS_NSTATS); | |
70bc068c RS |
3552 | BUILD_BUG_ON(ARRAY_SIZE(mem_cgroup_lru_names) != NR_LRU_LISTS); |
3553 | ||
af7c4b0e | 3554 | for (i = 0; i < MEM_CGROUP_STAT_NSTATS; i++) { |
bff6bb83 | 3555 | if (i == MEM_CGROUP_STAT_SWAP && !do_swap_account) |
1dd3a273 | 3556 | continue; |
af7c4b0e JW |
3557 | seq_printf(m, "%s %ld\n", mem_cgroup_stat_names[i], |
3558 | mem_cgroup_read_stat(memcg, i) * PAGE_SIZE); | |
1dd3a273 | 3559 | } |
7b854121 | 3560 | |
af7c4b0e JW |
3561 | for (i = 0; i < MEM_CGROUP_EVENTS_NSTATS; i++) |
3562 | seq_printf(m, "%s %lu\n", mem_cgroup_events_names[i], | |
3563 | mem_cgroup_read_events(memcg, i)); | |
3564 | ||
3565 | for (i = 0; i < NR_LRU_LISTS; i++) | |
3566 | seq_printf(m, "%s %lu\n", mem_cgroup_lru_names[i], | |
3567 | mem_cgroup_nr_lru_pages(memcg, BIT(i)) * PAGE_SIZE); | |
3568 | ||
14067bb3 | 3569 | /* Hierarchical information */ |
3e32cb2e JW |
3570 | memory = memsw = PAGE_COUNTER_MAX; |
3571 | for (mi = memcg; mi; mi = parent_mem_cgroup(mi)) { | |
3572 | memory = min(memory, mi->memory.limit); | |
3573 | memsw = min(memsw, mi->memsw.limit); | |
fee7b548 | 3574 | } |
3e32cb2e JW |
3575 | seq_printf(m, "hierarchical_memory_limit %llu\n", |
3576 | (u64)memory * PAGE_SIZE); | |
3577 | if (do_swap_account) | |
3578 | seq_printf(m, "hierarchical_memsw_limit %llu\n", | |
3579 | (u64)memsw * PAGE_SIZE); | |
7f016ee8 | 3580 | |
af7c4b0e JW |
3581 | for (i = 0; i < MEM_CGROUP_STAT_NSTATS; i++) { |
3582 | long long val = 0; | |
3583 | ||
bff6bb83 | 3584 | if (i == MEM_CGROUP_STAT_SWAP && !do_swap_account) |
1dd3a273 | 3585 | continue; |
af7c4b0e JW |
3586 | for_each_mem_cgroup_tree(mi, memcg) |
3587 | val += mem_cgroup_read_stat(mi, i) * PAGE_SIZE; | |
3588 | seq_printf(m, "total_%s %lld\n", mem_cgroup_stat_names[i], val); | |
3589 | } | |
3590 | ||
3591 | for (i = 0; i < MEM_CGROUP_EVENTS_NSTATS; i++) { | |
3592 | unsigned long long val = 0; | |
3593 | ||
3594 | for_each_mem_cgroup_tree(mi, memcg) | |
3595 | val += mem_cgroup_read_events(mi, i); | |
3596 | seq_printf(m, "total_%s %llu\n", | |
3597 | mem_cgroup_events_names[i], val); | |
3598 | } | |
3599 | ||
3600 | for (i = 0; i < NR_LRU_LISTS; i++) { | |
3601 | unsigned long long val = 0; | |
3602 | ||
3603 | for_each_mem_cgroup_tree(mi, memcg) | |
3604 | val += mem_cgroup_nr_lru_pages(mi, BIT(i)) * PAGE_SIZE; | |
3605 | seq_printf(m, "total_%s %llu\n", mem_cgroup_lru_names[i], val); | |
1dd3a273 | 3606 | } |
14067bb3 | 3607 | |
7f016ee8 | 3608 | #ifdef CONFIG_DEBUG_VM |
7f016ee8 KM |
3609 | { |
3610 | int nid, zid; | |
3611 | struct mem_cgroup_per_zone *mz; | |
89abfab1 | 3612 | struct zone_reclaim_stat *rstat; |
7f016ee8 KM |
3613 | unsigned long recent_rotated[2] = {0, 0}; |
3614 | unsigned long recent_scanned[2] = {0, 0}; | |
3615 | ||
3616 | for_each_online_node(nid) | |
3617 | for (zid = 0; zid < MAX_NR_ZONES; zid++) { | |
e231875b | 3618 | mz = &memcg->nodeinfo[nid]->zoneinfo[zid]; |
89abfab1 | 3619 | rstat = &mz->lruvec.reclaim_stat; |
7f016ee8 | 3620 | |
89abfab1 HD |
3621 | recent_rotated[0] += rstat->recent_rotated[0]; |
3622 | recent_rotated[1] += rstat->recent_rotated[1]; | |
3623 | recent_scanned[0] += rstat->recent_scanned[0]; | |
3624 | recent_scanned[1] += rstat->recent_scanned[1]; | |
7f016ee8 | 3625 | } |
78ccf5b5 JW |
3626 | seq_printf(m, "recent_rotated_anon %lu\n", recent_rotated[0]); |
3627 | seq_printf(m, "recent_rotated_file %lu\n", recent_rotated[1]); | |
3628 | seq_printf(m, "recent_scanned_anon %lu\n", recent_scanned[0]); | |
3629 | seq_printf(m, "recent_scanned_file %lu\n", recent_scanned[1]); | |
7f016ee8 KM |
3630 | } |
3631 | #endif | |
3632 | ||
d2ceb9b7 KH |
3633 | return 0; |
3634 | } | |
3635 | ||
182446d0 TH |
3636 | static u64 mem_cgroup_swappiness_read(struct cgroup_subsys_state *css, |
3637 | struct cftype *cft) | |
a7885eb8 | 3638 | { |
182446d0 | 3639 | struct mem_cgroup *memcg = mem_cgroup_from_css(css); |
a7885eb8 | 3640 | |
1f4c025b | 3641 | return mem_cgroup_swappiness(memcg); |
a7885eb8 KM |
3642 | } |
3643 | ||
182446d0 TH |
3644 | static int mem_cgroup_swappiness_write(struct cgroup_subsys_state *css, |
3645 | struct cftype *cft, u64 val) | |
a7885eb8 | 3646 | { |
182446d0 | 3647 | struct mem_cgroup *memcg = mem_cgroup_from_css(css); |
a7885eb8 | 3648 | |
3dae7fec | 3649 | if (val > 100) |
a7885eb8 KM |
3650 | return -EINVAL; |
3651 | ||
14208b0e | 3652 | if (css->parent) |
3dae7fec JW |
3653 | memcg->swappiness = val; |
3654 | else | |
3655 | vm_swappiness = val; | |
068b38c1 | 3656 | |
a7885eb8 KM |
3657 | return 0; |
3658 | } | |
3659 | ||
2e72b634 KS |
3660 | static void __mem_cgroup_threshold(struct mem_cgroup *memcg, bool swap) |
3661 | { | |
3662 | struct mem_cgroup_threshold_ary *t; | |
3e32cb2e | 3663 | unsigned long usage; |
2e72b634 KS |
3664 | int i; |
3665 | ||
3666 | rcu_read_lock(); | |
3667 | if (!swap) | |
2c488db2 | 3668 | t = rcu_dereference(memcg->thresholds.primary); |
2e72b634 | 3669 | else |
2c488db2 | 3670 | t = rcu_dereference(memcg->memsw_thresholds.primary); |
2e72b634 KS |
3671 | |
3672 | if (!t) | |
3673 | goto unlock; | |
3674 | ||
ce00a967 | 3675 | usage = mem_cgroup_usage(memcg, swap); |
2e72b634 KS |
3676 | |
3677 | /* | |
748dad36 | 3678 | * current_threshold points to threshold just below or equal to usage. |
2e72b634 KS |
3679 | * If it's not true, a threshold was crossed after last |
3680 | * call of __mem_cgroup_threshold(). | |
3681 | */ | |
5407a562 | 3682 | i = t->current_threshold; |
2e72b634 KS |
3683 | |
3684 | /* | |
3685 | * Iterate backward over array of thresholds starting from | |
3686 | * current_threshold and check if a threshold is crossed. | |
3687 | * If none of thresholds below usage is crossed, we read | |
3688 | * only one element of the array here. | |
3689 | */ | |
3690 | for (; i >= 0 && unlikely(t->entries[i].threshold > usage); i--) | |
3691 | eventfd_signal(t->entries[i].eventfd, 1); | |
3692 | ||
3693 | /* i = current_threshold + 1 */ | |
3694 | i++; | |
3695 | ||
3696 | /* | |
3697 | * Iterate forward over array of thresholds starting from | |
3698 | * current_threshold+1 and check if a threshold is crossed. | |
3699 | * If none of thresholds above usage is crossed, we read | |
3700 | * only one element of the array here. | |
3701 | */ | |
3702 | for (; i < t->size && unlikely(t->entries[i].threshold <= usage); i++) | |
3703 | eventfd_signal(t->entries[i].eventfd, 1); | |
3704 | ||
3705 | /* Update current_threshold */ | |
5407a562 | 3706 | t->current_threshold = i - 1; |
2e72b634 KS |
3707 | unlock: |
3708 | rcu_read_unlock(); | |
3709 | } | |
3710 | ||
3711 | static void mem_cgroup_threshold(struct mem_cgroup *memcg) | |
3712 | { | |
ad4ca5f4 KS |
3713 | while (memcg) { |
3714 | __mem_cgroup_threshold(memcg, false); | |
3715 | if (do_swap_account) | |
3716 | __mem_cgroup_threshold(memcg, true); | |
3717 | ||
3718 | memcg = parent_mem_cgroup(memcg); | |
3719 | } | |
2e72b634 KS |
3720 | } |
3721 | ||
3722 | static int compare_thresholds(const void *a, const void *b) | |
3723 | { | |
3724 | const struct mem_cgroup_threshold *_a = a; | |
3725 | const struct mem_cgroup_threshold *_b = b; | |
3726 | ||
2bff24a3 GT |
3727 | if (_a->threshold > _b->threshold) |
3728 | return 1; | |
3729 | ||
3730 | if (_a->threshold < _b->threshold) | |
3731 | return -1; | |
3732 | ||
3733 | return 0; | |
2e72b634 KS |
3734 | } |
3735 | ||
c0ff4b85 | 3736 | static int mem_cgroup_oom_notify_cb(struct mem_cgroup *memcg) |
9490ff27 KH |
3737 | { |
3738 | struct mem_cgroup_eventfd_list *ev; | |
3739 | ||
2bcf2e92 MH |
3740 | spin_lock(&memcg_oom_lock); |
3741 | ||
c0ff4b85 | 3742 | list_for_each_entry(ev, &memcg->oom_notify, list) |
9490ff27 | 3743 | eventfd_signal(ev->eventfd, 1); |
2bcf2e92 MH |
3744 | |
3745 | spin_unlock(&memcg_oom_lock); | |
9490ff27 KH |
3746 | return 0; |
3747 | } | |
3748 | ||
c0ff4b85 | 3749 | static void mem_cgroup_oom_notify(struct mem_cgroup *memcg) |
9490ff27 | 3750 | { |
7d74b06f KH |
3751 | struct mem_cgroup *iter; |
3752 | ||
c0ff4b85 | 3753 | for_each_mem_cgroup_tree(iter, memcg) |
7d74b06f | 3754 | mem_cgroup_oom_notify_cb(iter); |
9490ff27 KH |
3755 | } |
3756 | ||
59b6f873 | 3757 | static int __mem_cgroup_usage_register_event(struct mem_cgroup *memcg, |
347c4a87 | 3758 | struct eventfd_ctx *eventfd, const char *args, enum res_type type) |
2e72b634 | 3759 | { |
2c488db2 KS |
3760 | struct mem_cgroup_thresholds *thresholds; |
3761 | struct mem_cgroup_threshold_ary *new; | |
3e32cb2e JW |
3762 | unsigned long threshold; |
3763 | unsigned long usage; | |
2c488db2 | 3764 | int i, size, ret; |
2e72b634 | 3765 | |
650c5e56 | 3766 | ret = page_counter_memparse(args, "-1", &threshold); |
2e72b634 KS |
3767 | if (ret) |
3768 | return ret; | |
3769 | ||
3770 | mutex_lock(&memcg->thresholds_lock); | |
2c488db2 | 3771 | |
05b84301 | 3772 | if (type == _MEM) { |
2c488db2 | 3773 | thresholds = &memcg->thresholds; |
ce00a967 | 3774 | usage = mem_cgroup_usage(memcg, false); |
05b84301 | 3775 | } else if (type == _MEMSWAP) { |
2c488db2 | 3776 | thresholds = &memcg->memsw_thresholds; |
ce00a967 | 3777 | usage = mem_cgroup_usage(memcg, true); |
05b84301 | 3778 | } else |
2e72b634 KS |
3779 | BUG(); |
3780 | ||
2e72b634 | 3781 | /* Check if a threshold crossed before adding a new one */ |
2c488db2 | 3782 | if (thresholds->primary) |
2e72b634 KS |
3783 | __mem_cgroup_threshold(memcg, type == _MEMSWAP); |
3784 | ||
2c488db2 | 3785 | size = thresholds->primary ? thresholds->primary->size + 1 : 1; |
2e72b634 KS |
3786 | |
3787 | /* Allocate memory for new array of thresholds */ | |
2c488db2 | 3788 | new = kmalloc(sizeof(*new) + size * sizeof(struct mem_cgroup_threshold), |
2e72b634 | 3789 | GFP_KERNEL); |
2c488db2 | 3790 | if (!new) { |
2e72b634 KS |
3791 | ret = -ENOMEM; |
3792 | goto unlock; | |
3793 | } | |
2c488db2 | 3794 | new->size = size; |
2e72b634 KS |
3795 | |
3796 | /* Copy thresholds (if any) to new array */ | |
2c488db2 KS |
3797 | if (thresholds->primary) { |
3798 | memcpy(new->entries, thresholds->primary->entries, (size - 1) * | |
2e72b634 | 3799 | sizeof(struct mem_cgroup_threshold)); |
2c488db2 KS |
3800 | } |
3801 | ||
2e72b634 | 3802 | /* Add new threshold */ |
2c488db2 KS |
3803 | new->entries[size - 1].eventfd = eventfd; |
3804 | new->entries[size - 1].threshold = threshold; | |
2e72b634 KS |
3805 | |
3806 | /* Sort thresholds. Registering of new threshold isn't time-critical */ | |
2c488db2 | 3807 | sort(new->entries, size, sizeof(struct mem_cgroup_threshold), |
2e72b634 KS |
3808 | compare_thresholds, NULL); |
3809 | ||
3810 | /* Find current threshold */ | |
2c488db2 | 3811 | new->current_threshold = -1; |
2e72b634 | 3812 | for (i = 0; i < size; i++) { |
748dad36 | 3813 | if (new->entries[i].threshold <= usage) { |
2e72b634 | 3814 | /* |
2c488db2 KS |
3815 | * new->current_threshold will not be used until |
3816 | * rcu_assign_pointer(), so it's safe to increment | |
2e72b634 KS |
3817 | * it here. |
3818 | */ | |
2c488db2 | 3819 | ++new->current_threshold; |
748dad36 SZ |
3820 | } else |
3821 | break; | |
2e72b634 KS |
3822 | } |
3823 | ||
2c488db2 KS |
3824 | /* Free old spare buffer and save old primary buffer as spare */ |
3825 | kfree(thresholds->spare); | |
3826 | thresholds->spare = thresholds->primary; | |
3827 | ||
3828 | rcu_assign_pointer(thresholds->primary, new); | |
2e72b634 | 3829 | |
907860ed | 3830 | /* To be sure that nobody uses thresholds */ |
2e72b634 KS |
3831 | synchronize_rcu(); |
3832 | ||
2e72b634 KS |
3833 | unlock: |
3834 | mutex_unlock(&memcg->thresholds_lock); | |
3835 | ||
3836 | return ret; | |
3837 | } | |
3838 | ||
59b6f873 | 3839 | static int mem_cgroup_usage_register_event(struct mem_cgroup *memcg, |
347c4a87 TH |
3840 | struct eventfd_ctx *eventfd, const char *args) |
3841 | { | |
59b6f873 | 3842 | return __mem_cgroup_usage_register_event(memcg, eventfd, args, _MEM); |
347c4a87 TH |
3843 | } |
3844 | ||
59b6f873 | 3845 | static int memsw_cgroup_usage_register_event(struct mem_cgroup *memcg, |
347c4a87 TH |
3846 | struct eventfd_ctx *eventfd, const char *args) |
3847 | { | |
59b6f873 | 3848 | return __mem_cgroup_usage_register_event(memcg, eventfd, args, _MEMSWAP); |
347c4a87 TH |
3849 | } |
3850 | ||
59b6f873 | 3851 | static void __mem_cgroup_usage_unregister_event(struct mem_cgroup *memcg, |
347c4a87 | 3852 | struct eventfd_ctx *eventfd, enum res_type type) |
2e72b634 | 3853 | { |
2c488db2 KS |
3854 | struct mem_cgroup_thresholds *thresholds; |
3855 | struct mem_cgroup_threshold_ary *new; | |
3e32cb2e | 3856 | unsigned long usage; |
2c488db2 | 3857 | int i, j, size; |
2e72b634 KS |
3858 | |
3859 | mutex_lock(&memcg->thresholds_lock); | |
05b84301 JW |
3860 | |
3861 | if (type == _MEM) { | |
2c488db2 | 3862 | thresholds = &memcg->thresholds; |
ce00a967 | 3863 | usage = mem_cgroup_usage(memcg, false); |
05b84301 | 3864 | } else if (type == _MEMSWAP) { |
2c488db2 | 3865 | thresholds = &memcg->memsw_thresholds; |
ce00a967 | 3866 | usage = mem_cgroup_usage(memcg, true); |
05b84301 | 3867 | } else |
2e72b634 KS |
3868 | BUG(); |
3869 | ||
371528ca AV |
3870 | if (!thresholds->primary) |
3871 | goto unlock; | |
3872 | ||
2e72b634 KS |
3873 | /* Check if a threshold crossed before removing */ |
3874 | __mem_cgroup_threshold(memcg, type == _MEMSWAP); | |
3875 | ||
3876 | /* Calculate new number of threshold */ | |
2c488db2 KS |
3877 | size = 0; |
3878 | for (i = 0; i < thresholds->primary->size; i++) { | |
3879 | if (thresholds->primary->entries[i].eventfd != eventfd) | |
2e72b634 KS |
3880 | size++; |
3881 | } | |
3882 | ||
2c488db2 | 3883 | new = thresholds->spare; |
907860ed | 3884 | |
2e72b634 KS |
3885 | /* Set thresholds array to NULL if we don't have thresholds */ |
3886 | if (!size) { | |
2c488db2 KS |
3887 | kfree(new); |
3888 | new = NULL; | |
907860ed | 3889 | goto swap_buffers; |
2e72b634 KS |
3890 | } |
3891 | ||
2c488db2 | 3892 | new->size = size; |
2e72b634 KS |
3893 | |
3894 | /* Copy thresholds and find current threshold */ | |
2c488db2 KS |
3895 | new->current_threshold = -1; |
3896 | for (i = 0, j = 0; i < thresholds->primary->size; i++) { | |
3897 | if (thresholds->primary->entries[i].eventfd == eventfd) | |
2e72b634 KS |
3898 | continue; |
3899 | ||
2c488db2 | 3900 | new->entries[j] = thresholds->primary->entries[i]; |
748dad36 | 3901 | if (new->entries[j].threshold <= usage) { |
2e72b634 | 3902 | /* |
2c488db2 | 3903 | * new->current_threshold will not be used |
2e72b634 KS |
3904 | * until rcu_assign_pointer(), so it's safe to increment |
3905 | * it here. | |
3906 | */ | |
2c488db2 | 3907 | ++new->current_threshold; |
2e72b634 KS |
3908 | } |
3909 | j++; | |
3910 | } | |
3911 | ||
907860ed | 3912 | swap_buffers: |
2c488db2 KS |
3913 | /* Swap primary and spare array */ |
3914 | thresholds->spare = thresholds->primary; | |
8c757763 SZ |
3915 | /* If all events are unregistered, free the spare array */ |
3916 | if (!new) { | |
3917 | kfree(thresholds->spare); | |
3918 | thresholds->spare = NULL; | |
3919 | } | |
3920 | ||
2c488db2 | 3921 | rcu_assign_pointer(thresholds->primary, new); |
2e72b634 | 3922 | |
907860ed | 3923 | /* To be sure that nobody uses thresholds */ |
2e72b634 | 3924 | synchronize_rcu(); |
371528ca | 3925 | unlock: |
2e72b634 | 3926 | mutex_unlock(&memcg->thresholds_lock); |
2e72b634 | 3927 | } |
c1e862c1 | 3928 | |
59b6f873 | 3929 | static void mem_cgroup_usage_unregister_event(struct mem_cgroup *memcg, |
347c4a87 TH |
3930 | struct eventfd_ctx *eventfd) |
3931 | { | |
59b6f873 | 3932 | return __mem_cgroup_usage_unregister_event(memcg, eventfd, _MEM); |
347c4a87 TH |
3933 | } |
3934 | ||
59b6f873 | 3935 | static void memsw_cgroup_usage_unregister_event(struct mem_cgroup *memcg, |
347c4a87 TH |
3936 | struct eventfd_ctx *eventfd) |
3937 | { | |
59b6f873 | 3938 | return __mem_cgroup_usage_unregister_event(memcg, eventfd, _MEMSWAP); |
347c4a87 TH |
3939 | } |
3940 | ||
59b6f873 | 3941 | static int mem_cgroup_oom_register_event(struct mem_cgroup *memcg, |
347c4a87 | 3942 | struct eventfd_ctx *eventfd, const char *args) |
9490ff27 | 3943 | { |
9490ff27 | 3944 | struct mem_cgroup_eventfd_list *event; |
9490ff27 | 3945 | |
9490ff27 KH |
3946 | event = kmalloc(sizeof(*event), GFP_KERNEL); |
3947 | if (!event) | |
3948 | return -ENOMEM; | |
3949 | ||
1af8efe9 | 3950 | spin_lock(&memcg_oom_lock); |
9490ff27 KH |
3951 | |
3952 | event->eventfd = eventfd; | |
3953 | list_add(&event->list, &memcg->oom_notify); | |
3954 | ||
3955 | /* already in OOM ? */ | |
79dfdacc | 3956 | if (atomic_read(&memcg->under_oom)) |
9490ff27 | 3957 | eventfd_signal(eventfd, 1); |
1af8efe9 | 3958 | spin_unlock(&memcg_oom_lock); |
9490ff27 KH |
3959 | |
3960 | return 0; | |
3961 | } | |
3962 | ||
59b6f873 | 3963 | static void mem_cgroup_oom_unregister_event(struct mem_cgroup *memcg, |
347c4a87 | 3964 | struct eventfd_ctx *eventfd) |
9490ff27 | 3965 | { |
9490ff27 | 3966 | struct mem_cgroup_eventfd_list *ev, *tmp; |
9490ff27 | 3967 | |
1af8efe9 | 3968 | spin_lock(&memcg_oom_lock); |
9490ff27 | 3969 | |
c0ff4b85 | 3970 | list_for_each_entry_safe(ev, tmp, &memcg->oom_notify, list) { |
9490ff27 KH |
3971 | if (ev->eventfd == eventfd) { |
3972 | list_del(&ev->list); | |
3973 | kfree(ev); | |
3974 | } | |
3975 | } | |
3976 | ||
1af8efe9 | 3977 | spin_unlock(&memcg_oom_lock); |
9490ff27 KH |
3978 | } |
3979 | ||
2da8ca82 | 3980 | static int mem_cgroup_oom_control_read(struct seq_file *sf, void *v) |
3c11ecf4 | 3981 | { |
2da8ca82 | 3982 | struct mem_cgroup *memcg = mem_cgroup_from_css(seq_css(sf)); |
3c11ecf4 | 3983 | |
791badbd TH |
3984 | seq_printf(sf, "oom_kill_disable %d\n", memcg->oom_kill_disable); |
3985 | seq_printf(sf, "under_oom %d\n", (bool)atomic_read(&memcg->under_oom)); | |
3c11ecf4 KH |
3986 | return 0; |
3987 | } | |
3988 | ||
182446d0 | 3989 | static int mem_cgroup_oom_control_write(struct cgroup_subsys_state *css, |
3c11ecf4 KH |
3990 | struct cftype *cft, u64 val) |
3991 | { | |
182446d0 | 3992 | struct mem_cgroup *memcg = mem_cgroup_from_css(css); |
3c11ecf4 KH |
3993 | |
3994 | /* cannot set to root cgroup and only 0 and 1 are allowed */ | |
14208b0e | 3995 | if (!css->parent || !((val == 0) || (val == 1))) |
3c11ecf4 KH |
3996 | return -EINVAL; |
3997 | ||
c0ff4b85 | 3998 | memcg->oom_kill_disable = val; |
4d845ebf | 3999 | if (!val) |
c0ff4b85 | 4000 | memcg_oom_recover(memcg); |
3dae7fec | 4001 | |
3c11ecf4 KH |
4002 | return 0; |
4003 | } | |
4004 | ||
c255a458 | 4005 | #ifdef CONFIG_MEMCG_KMEM |
cbe128e3 | 4006 | static int memcg_init_kmem(struct mem_cgroup *memcg, struct cgroup_subsys *ss) |
e5671dfa | 4007 | { |
55007d84 GC |
4008 | int ret; |
4009 | ||
55007d84 GC |
4010 | ret = memcg_propagate_kmem(memcg); |
4011 | if (ret) | |
4012 | return ret; | |
2633d7a0 | 4013 | |
1d62e436 | 4014 | return mem_cgroup_sockets_init(memcg, ss); |
573b400d | 4015 | } |
e5671dfa | 4016 | |
10d5ebf4 | 4017 | static void memcg_destroy_kmem(struct mem_cgroup *memcg) |
d1a4c0b3 | 4018 | { |
d5b3cf71 | 4019 | memcg_destroy_kmem_caches(memcg); |
1d62e436 | 4020 | mem_cgroup_sockets_destroy(memcg); |
10d5ebf4 | 4021 | } |
e5671dfa | 4022 | #else |
cbe128e3 | 4023 | static int memcg_init_kmem(struct mem_cgroup *memcg, struct cgroup_subsys *ss) |
e5671dfa GC |
4024 | { |
4025 | return 0; | |
4026 | } | |
d1a4c0b3 | 4027 | |
10d5ebf4 LZ |
4028 | static void memcg_destroy_kmem(struct mem_cgroup *memcg) |
4029 | { | |
4030 | } | |
e5671dfa GC |
4031 | #endif |
4032 | ||
3bc942f3 TH |
4033 | /* |
4034 | * DO NOT USE IN NEW FILES. | |
4035 | * | |
4036 | * "cgroup.event_control" implementation. | |
4037 | * | |
4038 | * This is way over-engineered. It tries to support fully configurable | |
4039 | * events for each user. Such level of flexibility is completely | |
4040 | * unnecessary especially in the light of the planned unified hierarchy. | |
4041 | * | |
4042 | * Please deprecate this and replace with something simpler if at all | |
4043 | * possible. | |
4044 | */ | |
4045 | ||
79bd9814 TH |
4046 | /* |
4047 | * Unregister event and free resources. | |
4048 | * | |
4049 | * Gets called from workqueue. | |
4050 | */ | |
3bc942f3 | 4051 | static void memcg_event_remove(struct work_struct *work) |
79bd9814 | 4052 | { |
3bc942f3 TH |
4053 | struct mem_cgroup_event *event = |
4054 | container_of(work, struct mem_cgroup_event, remove); | |
59b6f873 | 4055 | struct mem_cgroup *memcg = event->memcg; |
79bd9814 TH |
4056 | |
4057 | remove_wait_queue(event->wqh, &event->wait); | |
4058 | ||
59b6f873 | 4059 | event->unregister_event(memcg, event->eventfd); |
79bd9814 TH |
4060 | |
4061 | /* Notify userspace the event is going away. */ | |
4062 | eventfd_signal(event->eventfd, 1); | |
4063 | ||
4064 | eventfd_ctx_put(event->eventfd); | |
4065 | kfree(event); | |
59b6f873 | 4066 | css_put(&memcg->css); |
79bd9814 TH |
4067 | } |
4068 | ||
4069 | /* | |
4070 | * Gets called on POLLHUP on eventfd when user closes it. | |
4071 | * | |
4072 | * Called with wqh->lock held and interrupts disabled. | |
4073 | */ | |
3bc942f3 TH |
4074 | static int memcg_event_wake(wait_queue_t *wait, unsigned mode, |
4075 | int sync, void *key) | |
79bd9814 | 4076 | { |
3bc942f3 TH |
4077 | struct mem_cgroup_event *event = |
4078 | container_of(wait, struct mem_cgroup_event, wait); | |
59b6f873 | 4079 | struct mem_cgroup *memcg = event->memcg; |
79bd9814 TH |
4080 | unsigned long flags = (unsigned long)key; |
4081 | ||
4082 | if (flags & POLLHUP) { | |
4083 | /* | |
4084 | * If the event has been detached at cgroup removal, we | |
4085 | * can simply return knowing the other side will cleanup | |
4086 | * for us. | |
4087 | * | |
4088 | * We can't race against event freeing since the other | |
4089 | * side will require wqh->lock via remove_wait_queue(), | |
4090 | * which we hold. | |
4091 | */ | |
fba94807 | 4092 | spin_lock(&memcg->event_list_lock); |
79bd9814 TH |
4093 | if (!list_empty(&event->list)) { |
4094 | list_del_init(&event->list); | |
4095 | /* | |
4096 | * We are in atomic context, but cgroup_event_remove() | |
4097 | * may sleep, so we have to call it in workqueue. | |
4098 | */ | |
4099 | schedule_work(&event->remove); | |
4100 | } | |
fba94807 | 4101 | spin_unlock(&memcg->event_list_lock); |
79bd9814 TH |
4102 | } |
4103 | ||
4104 | return 0; | |
4105 | } | |
4106 | ||
3bc942f3 | 4107 | static void memcg_event_ptable_queue_proc(struct file *file, |
79bd9814 TH |
4108 | wait_queue_head_t *wqh, poll_table *pt) |
4109 | { | |
3bc942f3 TH |
4110 | struct mem_cgroup_event *event = |
4111 | container_of(pt, struct mem_cgroup_event, pt); | |
79bd9814 TH |
4112 | |
4113 | event->wqh = wqh; | |
4114 | add_wait_queue(wqh, &event->wait); | |
4115 | } | |
4116 | ||
4117 | /* | |
3bc942f3 TH |
4118 | * DO NOT USE IN NEW FILES. |
4119 | * | |
79bd9814 TH |
4120 | * Parse input and register new cgroup event handler. |
4121 | * | |
4122 | * Input must be in format '<event_fd> <control_fd> <args>'. | |
4123 | * Interpretation of args is defined by control file implementation. | |
4124 | */ | |
451af504 TH |
4125 | static ssize_t memcg_write_event_control(struct kernfs_open_file *of, |
4126 | char *buf, size_t nbytes, loff_t off) | |
79bd9814 | 4127 | { |
451af504 | 4128 | struct cgroup_subsys_state *css = of_css(of); |
fba94807 | 4129 | struct mem_cgroup *memcg = mem_cgroup_from_css(css); |
3bc942f3 | 4130 | struct mem_cgroup_event *event; |
79bd9814 TH |
4131 | struct cgroup_subsys_state *cfile_css; |
4132 | unsigned int efd, cfd; | |
4133 | struct fd efile; | |
4134 | struct fd cfile; | |
fba94807 | 4135 | const char *name; |
79bd9814 TH |
4136 | char *endp; |
4137 | int ret; | |
4138 | ||
451af504 TH |
4139 | buf = strstrip(buf); |
4140 | ||
4141 | efd = simple_strtoul(buf, &endp, 10); | |
79bd9814 TH |
4142 | if (*endp != ' ') |
4143 | return -EINVAL; | |
451af504 | 4144 | buf = endp + 1; |
79bd9814 | 4145 | |
451af504 | 4146 | cfd = simple_strtoul(buf, &endp, 10); |
79bd9814 TH |
4147 | if ((*endp != ' ') && (*endp != '\0')) |
4148 | return -EINVAL; | |
451af504 | 4149 | buf = endp + 1; |
79bd9814 TH |
4150 | |
4151 | event = kzalloc(sizeof(*event), GFP_KERNEL); | |
4152 | if (!event) | |
4153 | return -ENOMEM; | |
4154 | ||
59b6f873 | 4155 | event->memcg = memcg; |
79bd9814 | 4156 | INIT_LIST_HEAD(&event->list); |
3bc942f3 TH |
4157 | init_poll_funcptr(&event->pt, memcg_event_ptable_queue_proc); |
4158 | init_waitqueue_func_entry(&event->wait, memcg_event_wake); | |
4159 | INIT_WORK(&event->remove, memcg_event_remove); | |
79bd9814 TH |
4160 | |
4161 | efile = fdget(efd); | |
4162 | if (!efile.file) { | |
4163 | ret = -EBADF; | |
4164 | goto out_kfree; | |
4165 | } | |
4166 | ||
4167 | event->eventfd = eventfd_ctx_fileget(efile.file); | |
4168 | if (IS_ERR(event->eventfd)) { | |
4169 | ret = PTR_ERR(event->eventfd); | |
4170 | goto out_put_efile; | |
4171 | } | |
4172 | ||
4173 | cfile = fdget(cfd); | |
4174 | if (!cfile.file) { | |
4175 | ret = -EBADF; | |
4176 | goto out_put_eventfd; | |
4177 | } | |
4178 | ||
4179 | /* the process need read permission on control file */ | |
4180 | /* AV: shouldn't we check that it's been opened for read instead? */ | |
4181 | ret = inode_permission(file_inode(cfile.file), MAY_READ); | |
4182 | if (ret < 0) | |
4183 | goto out_put_cfile; | |
4184 | ||
fba94807 TH |
4185 | /* |
4186 | * Determine the event callbacks and set them in @event. This used | |
4187 | * to be done via struct cftype but cgroup core no longer knows | |
4188 | * about these events. The following is crude but the whole thing | |
4189 | * is for compatibility anyway. | |
3bc942f3 TH |
4190 | * |
4191 | * DO NOT ADD NEW FILES. | |
fba94807 | 4192 | */ |
b583043e | 4193 | name = cfile.file->f_path.dentry->d_name.name; |
fba94807 TH |
4194 | |
4195 | if (!strcmp(name, "memory.usage_in_bytes")) { | |
4196 | event->register_event = mem_cgroup_usage_register_event; | |
4197 | event->unregister_event = mem_cgroup_usage_unregister_event; | |
4198 | } else if (!strcmp(name, "memory.oom_control")) { | |
4199 | event->register_event = mem_cgroup_oom_register_event; | |
4200 | event->unregister_event = mem_cgroup_oom_unregister_event; | |
4201 | } else if (!strcmp(name, "memory.pressure_level")) { | |
4202 | event->register_event = vmpressure_register_event; | |
4203 | event->unregister_event = vmpressure_unregister_event; | |
4204 | } else if (!strcmp(name, "memory.memsw.usage_in_bytes")) { | |
347c4a87 TH |
4205 | event->register_event = memsw_cgroup_usage_register_event; |
4206 | event->unregister_event = memsw_cgroup_usage_unregister_event; | |
fba94807 TH |
4207 | } else { |
4208 | ret = -EINVAL; | |
4209 | goto out_put_cfile; | |
4210 | } | |
4211 | ||
79bd9814 | 4212 | /* |
b5557c4c TH |
4213 | * Verify @cfile should belong to @css. Also, remaining events are |
4214 | * automatically removed on cgroup destruction but the removal is | |
4215 | * asynchronous, so take an extra ref on @css. | |
79bd9814 | 4216 | */ |
b583043e | 4217 | cfile_css = css_tryget_online_from_dir(cfile.file->f_path.dentry->d_parent, |
ec903c0c | 4218 | &memory_cgrp_subsys); |
79bd9814 | 4219 | ret = -EINVAL; |
5a17f543 | 4220 | if (IS_ERR(cfile_css)) |
79bd9814 | 4221 | goto out_put_cfile; |
5a17f543 TH |
4222 | if (cfile_css != css) { |
4223 | css_put(cfile_css); | |
79bd9814 | 4224 | goto out_put_cfile; |
5a17f543 | 4225 | } |
79bd9814 | 4226 | |
451af504 | 4227 | ret = event->register_event(memcg, event->eventfd, buf); |
79bd9814 TH |
4228 | if (ret) |
4229 | goto out_put_css; | |
4230 | ||
4231 | efile.file->f_op->poll(efile.file, &event->pt); | |
4232 | ||
fba94807 TH |
4233 | spin_lock(&memcg->event_list_lock); |
4234 | list_add(&event->list, &memcg->event_list); | |
4235 | spin_unlock(&memcg->event_list_lock); | |
79bd9814 TH |
4236 | |
4237 | fdput(cfile); | |
4238 | fdput(efile); | |
4239 | ||
451af504 | 4240 | return nbytes; |
79bd9814 TH |
4241 | |
4242 | out_put_css: | |
b5557c4c | 4243 | css_put(css); |
79bd9814 TH |
4244 | out_put_cfile: |
4245 | fdput(cfile); | |
4246 | out_put_eventfd: | |
4247 | eventfd_ctx_put(event->eventfd); | |
4248 | out_put_efile: | |
4249 | fdput(efile); | |
4250 | out_kfree: | |
4251 | kfree(event); | |
4252 | ||
4253 | return ret; | |
4254 | } | |
4255 | ||
241994ed | 4256 | static struct cftype mem_cgroup_legacy_files[] = { |
8cdea7c0 | 4257 | { |
0eea1030 | 4258 | .name = "usage_in_bytes", |
8c7c6e34 | 4259 | .private = MEMFILE_PRIVATE(_MEM, RES_USAGE), |
791badbd | 4260 | .read_u64 = mem_cgroup_read_u64, |
8cdea7c0 | 4261 | }, |
c84872e1 PE |
4262 | { |
4263 | .name = "max_usage_in_bytes", | |
8c7c6e34 | 4264 | .private = MEMFILE_PRIVATE(_MEM, RES_MAX_USAGE), |
6770c64e | 4265 | .write = mem_cgroup_reset, |
791badbd | 4266 | .read_u64 = mem_cgroup_read_u64, |
c84872e1 | 4267 | }, |
8cdea7c0 | 4268 | { |
0eea1030 | 4269 | .name = "limit_in_bytes", |
8c7c6e34 | 4270 | .private = MEMFILE_PRIVATE(_MEM, RES_LIMIT), |
451af504 | 4271 | .write = mem_cgroup_write, |
791badbd | 4272 | .read_u64 = mem_cgroup_read_u64, |
8cdea7c0 | 4273 | }, |
296c81d8 BS |
4274 | { |
4275 | .name = "soft_limit_in_bytes", | |
4276 | .private = MEMFILE_PRIVATE(_MEM, RES_SOFT_LIMIT), | |
451af504 | 4277 | .write = mem_cgroup_write, |
791badbd | 4278 | .read_u64 = mem_cgroup_read_u64, |
296c81d8 | 4279 | }, |
8cdea7c0 BS |
4280 | { |
4281 | .name = "failcnt", | |
8c7c6e34 | 4282 | .private = MEMFILE_PRIVATE(_MEM, RES_FAILCNT), |
6770c64e | 4283 | .write = mem_cgroup_reset, |
791badbd | 4284 | .read_u64 = mem_cgroup_read_u64, |
8cdea7c0 | 4285 | }, |
d2ceb9b7 KH |
4286 | { |
4287 | .name = "stat", | |
2da8ca82 | 4288 | .seq_show = memcg_stat_show, |
d2ceb9b7 | 4289 | }, |
c1e862c1 KH |
4290 | { |
4291 | .name = "force_empty", | |
6770c64e | 4292 | .write = mem_cgroup_force_empty_write, |
c1e862c1 | 4293 | }, |
18f59ea7 BS |
4294 | { |
4295 | .name = "use_hierarchy", | |
4296 | .write_u64 = mem_cgroup_hierarchy_write, | |
4297 | .read_u64 = mem_cgroup_hierarchy_read, | |
4298 | }, | |
79bd9814 | 4299 | { |
3bc942f3 | 4300 | .name = "cgroup.event_control", /* XXX: for compat */ |
451af504 | 4301 | .write = memcg_write_event_control, |
79bd9814 TH |
4302 | .flags = CFTYPE_NO_PREFIX, |
4303 | .mode = S_IWUGO, | |
4304 | }, | |
a7885eb8 KM |
4305 | { |
4306 | .name = "swappiness", | |
4307 | .read_u64 = mem_cgroup_swappiness_read, | |
4308 | .write_u64 = mem_cgroup_swappiness_write, | |
4309 | }, | |
7dc74be0 DN |
4310 | { |
4311 | .name = "move_charge_at_immigrate", | |
4312 | .read_u64 = mem_cgroup_move_charge_read, | |
4313 | .write_u64 = mem_cgroup_move_charge_write, | |
4314 | }, | |
9490ff27 KH |
4315 | { |
4316 | .name = "oom_control", | |
2da8ca82 | 4317 | .seq_show = mem_cgroup_oom_control_read, |
3c11ecf4 | 4318 | .write_u64 = mem_cgroup_oom_control_write, |
9490ff27 KH |
4319 | .private = MEMFILE_PRIVATE(_OOM_TYPE, OOM_CONTROL), |
4320 | }, | |
70ddf637 AV |
4321 | { |
4322 | .name = "pressure_level", | |
70ddf637 | 4323 | }, |
406eb0c9 YH |
4324 | #ifdef CONFIG_NUMA |
4325 | { | |
4326 | .name = "numa_stat", | |
2da8ca82 | 4327 | .seq_show = memcg_numa_stat_show, |
406eb0c9 YH |
4328 | }, |
4329 | #endif | |
510fc4e1 GC |
4330 | #ifdef CONFIG_MEMCG_KMEM |
4331 | { | |
4332 | .name = "kmem.limit_in_bytes", | |
4333 | .private = MEMFILE_PRIVATE(_KMEM, RES_LIMIT), | |
451af504 | 4334 | .write = mem_cgroup_write, |
791badbd | 4335 | .read_u64 = mem_cgroup_read_u64, |
510fc4e1 GC |
4336 | }, |
4337 | { | |
4338 | .name = "kmem.usage_in_bytes", | |
4339 | .private = MEMFILE_PRIVATE(_KMEM, RES_USAGE), | |
791badbd | 4340 | .read_u64 = mem_cgroup_read_u64, |
510fc4e1 GC |
4341 | }, |
4342 | { | |
4343 | .name = "kmem.failcnt", | |
4344 | .private = MEMFILE_PRIVATE(_KMEM, RES_FAILCNT), | |
6770c64e | 4345 | .write = mem_cgroup_reset, |
791badbd | 4346 | .read_u64 = mem_cgroup_read_u64, |
510fc4e1 GC |
4347 | }, |
4348 | { | |
4349 | .name = "kmem.max_usage_in_bytes", | |
4350 | .private = MEMFILE_PRIVATE(_KMEM, RES_MAX_USAGE), | |
6770c64e | 4351 | .write = mem_cgroup_reset, |
791badbd | 4352 | .read_u64 = mem_cgroup_read_u64, |
510fc4e1 | 4353 | }, |
749c5415 GC |
4354 | #ifdef CONFIG_SLABINFO |
4355 | { | |
4356 | .name = "kmem.slabinfo", | |
b047501c VD |
4357 | .seq_start = slab_start, |
4358 | .seq_next = slab_next, | |
4359 | .seq_stop = slab_stop, | |
4360 | .seq_show = memcg_slab_show, | |
749c5415 GC |
4361 | }, |
4362 | #endif | |
8c7c6e34 | 4363 | #endif |
6bc10349 | 4364 | { }, /* terminate */ |
af36f906 | 4365 | }; |
8c7c6e34 | 4366 | |
c0ff4b85 | 4367 | static int alloc_mem_cgroup_per_zone_info(struct mem_cgroup *memcg, int node) |
6d12e2d8 KH |
4368 | { |
4369 | struct mem_cgroup_per_node *pn; | |
1ecaab2b | 4370 | struct mem_cgroup_per_zone *mz; |
41e3355d | 4371 | int zone, tmp = node; |
1ecaab2b KH |
4372 | /* |
4373 | * This routine is called against possible nodes. | |
4374 | * But it's BUG to call kmalloc() against offline node. | |
4375 | * | |
4376 | * TODO: this routine can waste much memory for nodes which will | |
4377 | * never be onlined. It's better to use memory hotplug callback | |
4378 | * function. | |
4379 | */ | |
41e3355d KH |
4380 | if (!node_state(node, N_NORMAL_MEMORY)) |
4381 | tmp = -1; | |
17295c88 | 4382 | pn = kzalloc_node(sizeof(*pn), GFP_KERNEL, tmp); |
6d12e2d8 KH |
4383 | if (!pn) |
4384 | return 1; | |
1ecaab2b | 4385 | |
1ecaab2b KH |
4386 | for (zone = 0; zone < MAX_NR_ZONES; zone++) { |
4387 | mz = &pn->zoneinfo[zone]; | |
bea8c150 | 4388 | lruvec_init(&mz->lruvec); |
bb4cc1a8 AM |
4389 | mz->usage_in_excess = 0; |
4390 | mz->on_tree = false; | |
d79154bb | 4391 | mz->memcg = memcg; |
1ecaab2b | 4392 | } |
54f72fe0 | 4393 | memcg->nodeinfo[node] = pn; |
6d12e2d8 KH |
4394 | return 0; |
4395 | } | |
4396 | ||
c0ff4b85 | 4397 | static void free_mem_cgroup_per_zone_info(struct mem_cgroup *memcg, int node) |
1ecaab2b | 4398 | { |
54f72fe0 | 4399 | kfree(memcg->nodeinfo[node]); |
1ecaab2b KH |
4400 | } |
4401 | ||
33327948 KH |
4402 | static struct mem_cgroup *mem_cgroup_alloc(void) |
4403 | { | |
d79154bb | 4404 | struct mem_cgroup *memcg; |
8ff69e2c | 4405 | size_t size; |
33327948 | 4406 | |
8ff69e2c VD |
4407 | size = sizeof(struct mem_cgroup); |
4408 | size += nr_node_ids * sizeof(struct mem_cgroup_per_node *); | |
33327948 | 4409 | |
8ff69e2c | 4410 | memcg = kzalloc(size, GFP_KERNEL); |
d79154bb | 4411 | if (!memcg) |
e7bbcdf3 DC |
4412 | return NULL; |
4413 | ||
d79154bb HD |
4414 | memcg->stat = alloc_percpu(struct mem_cgroup_stat_cpu); |
4415 | if (!memcg->stat) | |
d2e61b8d | 4416 | goto out_free; |
d79154bb HD |
4417 | spin_lock_init(&memcg->pcp_counter_lock); |
4418 | return memcg; | |
d2e61b8d DC |
4419 | |
4420 | out_free: | |
8ff69e2c | 4421 | kfree(memcg); |
d2e61b8d | 4422 | return NULL; |
33327948 KH |
4423 | } |
4424 | ||
59927fb9 | 4425 | /* |
c8b2a36f GC |
4426 | * At destroying mem_cgroup, references from swap_cgroup can remain. |
4427 | * (scanning all at force_empty is too costly...) | |
4428 | * | |
4429 | * Instead of clearing all references at force_empty, we remember | |
4430 | * the number of reference from swap_cgroup and free mem_cgroup when | |
4431 | * it goes down to 0. | |
4432 | * | |
4433 | * Removal of cgroup itself succeeds regardless of refs from swap. | |
59927fb9 | 4434 | */ |
c8b2a36f GC |
4435 | |
4436 | static void __mem_cgroup_free(struct mem_cgroup *memcg) | |
59927fb9 | 4437 | { |
c8b2a36f | 4438 | int node; |
59927fb9 | 4439 | |
bb4cc1a8 | 4440 | mem_cgroup_remove_from_trees(memcg); |
c8b2a36f GC |
4441 | |
4442 | for_each_node(node) | |
4443 | free_mem_cgroup_per_zone_info(memcg, node); | |
4444 | ||
4445 | free_percpu(memcg->stat); | |
4446 | ||
a8964b9b | 4447 | disarm_static_keys(memcg); |
8ff69e2c | 4448 | kfree(memcg); |
59927fb9 | 4449 | } |
3afe36b1 | 4450 | |
7bcc1bb1 DN |
4451 | /* |
4452 | * Returns the parent mem_cgroup in memcgroup hierarchy with hierarchy enabled. | |
4453 | */ | |
e1aab161 | 4454 | struct mem_cgroup *parent_mem_cgroup(struct mem_cgroup *memcg) |
7bcc1bb1 | 4455 | { |
3e32cb2e | 4456 | if (!memcg->memory.parent) |
7bcc1bb1 | 4457 | return NULL; |
3e32cb2e | 4458 | return mem_cgroup_from_counter(memcg->memory.parent, memory); |
7bcc1bb1 | 4459 | } |
e1aab161 | 4460 | EXPORT_SYMBOL(parent_mem_cgroup); |
33327948 | 4461 | |
0eb253e2 | 4462 | static struct cgroup_subsys_state * __ref |
eb95419b | 4463 | mem_cgroup_css_alloc(struct cgroup_subsys_state *parent_css) |
8cdea7c0 | 4464 | { |
d142e3e6 | 4465 | struct mem_cgroup *memcg; |
04046e1a | 4466 | long error = -ENOMEM; |
6d12e2d8 | 4467 | int node; |
8cdea7c0 | 4468 | |
c0ff4b85 R |
4469 | memcg = mem_cgroup_alloc(); |
4470 | if (!memcg) | |
04046e1a | 4471 | return ERR_PTR(error); |
78fb7466 | 4472 | |
3ed28fa1 | 4473 | for_each_node(node) |
c0ff4b85 | 4474 | if (alloc_mem_cgroup_per_zone_info(memcg, node)) |
6d12e2d8 | 4475 | goto free_out; |
f64c3f54 | 4476 | |
c077719b | 4477 | /* root ? */ |
eb95419b | 4478 | if (parent_css == NULL) { |
a41c58a6 | 4479 | root_mem_cgroup = memcg; |
3e32cb2e | 4480 | page_counter_init(&memcg->memory, NULL); |
241994ed | 4481 | memcg->high = PAGE_COUNTER_MAX; |
24d404dc | 4482 | memcg->soft_limit = PAGE_COUNTER_MAX; |
3e32cb2e JW |
4483 | page_counter_init(&memcg->memsw, NULL); |
4484 | page_counter_init(&memcg->kmem, NULL); | |
18f59ea7 | 4485 | } |
28dbc4b6 | 4486 | |
d142e3e6 GC |
4487 | memcg->last_scanned_node = MAX_NUMNODES; |
4488 | INIT_LIST_HEAD(&memcg->oom_notify); | |
d142e3e6 GC |
4489 | memcg->move_charge_at_immigrate = 0; |
4490 | mutex_init(&memcg->thresholds_lock); | |
4491 | spin_lock_init(&memcg->move_lock); | |
70ddf637 | 4492 | vmpressure_init(&memcg->vmpressure); |
fba94807 TH |
4493 | INIT_LIST_HEAD(&memcg->event_list); |
4494 | spin_lock_init(&memcg->event_list_lock); | |
900a38f0 VD |
4495 | #ifdef CONFIG_MEMCG_KMEM |
4496 | memcg->kmemcg_id = -1; | |
900a38f0 | 4497 | #endif |
d142e3e6 GC |
4498 | |
4499 | return &memcg->css; | |
4500 | ||
4501 | free_out: | |
4502 | __mem_cgroup_free(memcg); | |
4503 | return ERR_PTR(error); | |
4504 | } | |
4505 | ||
4506 | static int | |
eb95419b | 4507 | mem_cgroup_css_online(struct cgroup_subsys_state *css) |
d142e3e6 | 4508 | { |
eb95419b | 4509 | struct mem_cgroup *memcg = mem_cgroup_from_css(css); |
5c9d535b | 4510 | struct mem_cgroup *parent = mem_cgroup_from_css(css->parent); |
2f7dd7a4 | 4511 | int ret; |
d142e3e6 | 4512 | |
15a4c835 | 4513 | if (css->id > MEM_CGROUP_ID_MAX) |
4219b2da LZ |
4514 | return -ENOSPC; |
4515 | ||
63876986 | 4516 | if (!parent) |
d142e3e6 GC |
4517 | return 0; |
4518 | ||
0999821b | 4519 | mutex_lock(&memcg_create_mutex); |
d142e3e6 GC |
4520 | |
4521 | memcg->use_hierarchy = parent->use_hierarchy; | |
4522 | memcg->oom_kill_disable = parent->oom_kill_disable; | |
4523 | memcg->swappiness = mem_cgroup_swappiness(parent); | |
4524 | ||
4525 | if (parent->use_hierarchy) { | |
3e32cb2e | 4526 | page_counter_init(&memcg->memory, &parent->memory); |
241994ed | 4527 | memcg->high = PAGE_COUNTER_MAX; |
24d404dc | 4528 | memcg->soft_limit = PAGE_COUNTER_MAX; |
3e32cb2e JW |
4529 | page_counter_init(&memcg->memsw, &parent->memsw); |
4530 | page_counter_init(&memcg->kmem, &parent->kmem); | |
55007d84 | 4531 | |
7bcc1bb1 | 4532 | /* |
8d76a979 LZ |
4533 | * No need to take a reference to the parent because cgroup |
4534 | * core guarantees its existence. | |
7bcc1bb1 | 4535 | */ |
18f59ea7 | 4536 | } else { |
3e32cb2e | 4537 | page_counter_init(&memcg->memory, NULL); |
241994ed | 4538 | memcg->high = PAGE_COUNTER_MAX; |
24d404dc | 4539 | memcg->soft_limit = PAGE_COUNTER_MAX; |
3e32cb2e JW |
4540 | page_counter_init(&memcg->memsw, NULL); |
4541 | page_counter_init(&memcg->kmem, NULL); | |
8c7f6edb TH |
4542 | /* |
4543 | * Deeper hierachy with use_hierarchy == false doesn't make | |
4544 | * much sense so let cgroup subsystem know about this | |
4545 | * unfortunate state in our controller. | |
4546 | */ | |
d142e3e6 | 4547 | if (parent != root_mem_cgroup) |
073219e9 | 4548 | memory_cgrp_subsys.broken_hierarchy = true; |
18f59ea7 | 4549 | } |
0999821b | 4550 | mutex_unlock(&memcg_create_mutex); |
d6441637 | 4551 | |
2f7dd7a4 JW |
4552 | ret = memcg_init_kmem(memcg, &memory_cgrp_subsys); |
4553 | if (ret) | |
4554 | return ret; | |
4555 | ||
4556 | /* | |
4557 | * Make sure the memcg is initialized: mem_cgroup_iter() | |
4558 | * orders reading memcg->initialized against its callers | |
4559 | * reading the memcg members. | |
4560 | */ | |
4561 | smp_store_release(&memcg->initialized, 1); | |
4562 | ||
4563 | return 0; | |
8cdea7c0 BS |
4564 | } |
4565 | ||
eb95419b | 4566 | static void mem_cgroup_css_offline(struct cgroup_subsys_state *css) |
df878fb0 | 4567 | { |
eb95419b | 4568 | struct mem_cgroup *memcg = mem_cgroup_from_css(css); |
3bc942f3 | 4569 | struct mem_cgroup_event *event, *tmp; |
79bd9814 TH |
4570 | |
4571 | /* | |
4572 | * Unregister events and notify userspace. | |
4573 | * Notify userspace about cgroup removing only after rmdir of cgroup | |
4574 | * directory to avoid race between userspace and kernelspace. | |
4575 | */ | |
fba94807 TH |
4576 | spin_lock(&memcg->event_list_lock); |
4577 | list_for_each_entry_safe(event, tmp, &memcg->event_list, list) { | |
79bd9814 TH |
4578 | list_del_init(&event->list); |
4579 | schedule_work(&event->remove); | |
4580 | } | |
fba94807 | 4581 | spin_unlock(&memcg->event_list_lock); |
ec64f515 | 4582 | |
33cb876e | 4583 | vmpressure_cleanup(&memcg->vmpressure); |
df878fb0 KH |
4584 | } |
4585 | ||
eb95419b | 4586 | static void mem_cgroup_css_free(struct cgroup_subsys_state *css) |
8cdea7c0 | 4587 | { |
eb95419b | 4588 | struct mem_cgroup *memcg = mem_cgroup_from_css(css); |
c268e994 | 4589 | |
10d5ebf4 | 4590 | memcg_destroy_kmem(memcg); |
465939a1 | 4591 | __mem_cgroup_free(memcg); |
8cdea7c0 BS |
4592 | } |
4593 | ||
1ced953b TH |
4594 | /** |
4595 | * mem_cgroup_css_reset - reset the states of a mem_cgroup | |
4596 | * @css: the target css | |
4597 | * | |
4598 | * Reset the states of the mem_cgroup associated with @css. This is | |
4599 | * invoked when the userland requests disabling on the default hierarchy | |
4600 | * but the memcg is pinned through dependency. The memcg should stop | |
4601 | * applying policies and should revert to the vanilla state as it may be | |
4602 | * made visible again. | |
4603 | * | |
4604 | * The current implementation only resets the essential configurations. | |
4605 | * This needs to be expanded to cover all the visible parts. | |
4606 | */ | |
4607 | static void mem_cgroup_css_reset(struct cgroup_subsys_state *css) | |
4608 | { | |
4609 | struct mem_cgroup *memcg = mem_cgroup_from_css(css); | |
4610 | ||
3e32cb2e JW |
4611 | mem_cgroup_resize_limit(memcg, PAGE_COUNTER_MAX); |
4612 | mem_cgroup_resize_memsw_limit(memcg, PAGE_COUNTER_MAX); | |
4613 | memcg_update_kmem_limit(memcg, PAGE_COUNTER_MAX); | |
241994ed JW |
4614 | memcg->low = 0; |
4615 | memcg->high = PAGE_COUNTER_MAX; | |
24d404dc | 4616 | memcg->soft_limit = PAGE_COUNTER_MAX; |
1ced953b TH |
4617 | } |
4618 | ||
02491447 | 4619 | #ifdef CONFIG_MMU |
7dc74be0 | 4620 | /* Handlers for move charge at task migration. */ |
854ffa8d | 4621 | static int mem_cgroup_do_precharge(unsigned long count) |
7dc74be0 | 4622 | { |
05b84301 | 4623 | int ret; |
9476db97 JW |
4624 | |
4625 | /* Try a single bulk charge without reclaim first */ | |
00501b53 | 4626 | ret = try_charge(mc.to, GFP_KERNEL & ~__GFP_WAIT, count); |
9476db97 | 4627 | if (!ret) { |
854ffa8d | 4628 | mc.precharge += count; |
854ffa8d DN |
4629 | return ret; |
4630 | } | |
692e7c45 | 4631 | if (ret == -EINTR) { |
00501b53 | 4632 | cancel_charge(root_mem_cgroup, count); |
692e7c45 JW |
4633 | return ret; |
4634 | } | |
9476db97 JW |
4635 | |
4636 | /* Try charges one by one with reclaim */ | |
854ffa8d | 4637 | while (count--) { |
00501b53 | 4638 | ret = try_charge(mc.to, GFP_KERNEL & ~__GFP_NORETRY, 1); |
9476db97 JW |
4639 | /* |
4640 | * In case of failure, any residual charges against | |
4641 | * mc.to will be dropped by mem_cgroup_clear_mc() | |
692e7c45 JW |
4642 | * later on. However, cancel any charges that are |
4643 | * bypassed to root right away or they'll be lost. | |
9476db97 | 4644 | */ |
692e7c45 | 4645 | if (ret == -EINTR) |
00501b53 | 4646 | cancel_charge(root_mem_cgroup, 1); |
38c5d72f | 4647 | if (ret) |
38c5d72f | 4648 | return ret; |
854ffa8d | 4649 | mc.precharge++; |
9476db97 | 4650 | cond_resched(); |
854ffa8d | 4651 | } |
9476db97 | 4652 | return 0; |
4ffef5fe DN |
4653 | } |
4654 | ||
4655 | /** | |
8d32ff84 | 4656 | * get_mctgt_type - get target type of moving charge |
4ffef5fe DN |
4657 | * @vma: the vma the pte to be checked belongs |
4658 | * @addr: the address corresponding to the pte to be checked | |
4659 | * @ptent: the pte to be checked | |
02491447 | 4660 | * @target: the pointer the target page or swap ent will be stored(can be NULL) |
4ffef5fe DN |
4661 | * |
4662 | * Returns | |
4663 | * 0(MC_TARGET_NONE): if the pte is not a target for move charge. | |
4664 | * 1(MC_TARGET_PAGE): if the page corresponding to this pte is a target for | |
4665 | * move charge. if @target is not NULL, the page is stored in target->page | |
4666 | * with extra refcnt got(Callers should handle it). | |
02491447 DN |
4667 | * 2(MC_TARGET_SWAP): if the swap entry corresponding to this pte is a |
4668 | * target for charge migration. if @target is not NULL, the entry is stored | |
4669 | * in target->ent. | |
4ffef5fe DN |
4670 | * |
4671 | * Called with pte lock held. | |
4672 | */ | |
4ffef5fe DN |
4673 | union mc_target { |
4674 | struct page *page; | |
02491447 | 4675 | swp_entry_t ent; |
4ffef5fe DN |
4676 | }; |
4677 | ||
4ffef5fe | 4678 | enum mc_target_type { |
8d32ff84 | 4679 | MC_TARGET_NONE = 0, |
4ffef5fe | 4680 | MC_TARGET_PAGE, |
02491447 | 4681 | MC_TARGET_SWAP, |
4ffef5fe DN |
4682 | }; |
4683 | ||
90254a65 DN |
4684 | static struct page *mc_handle_present_pte(struct vm_area_struct *vma, |
4685 | unsigned long addr, pte_t ptent) | |
4ffef5fe | 4686 | { |
90254a65 | 4687 | struct page *page = vm_normal_page(vma, addr, ptent); |
4ffef5fe | 4688 | |
90254a65 DN |
4689 | if (!page || !page_mapped(page)) |
4690 | return NULL; | |
4691 | if (PageAnon(page)) { | |
1dfab5ab | 4692 | if (!(mc.flags & MOVE_ANON)) |
90254a65 | 4693 | return NULL; |
1dfab5ab JW |
4694 | } else { |
4695 | if (!(mc.flags & MOVE_FILE)) | |
4696 | return NULL; | |
4697 | } | |
90254a65 DN |
4698 | if (!get_page_unless_zero(page)) |
4699 | return NULL; | |
4700 | ||
4701 | return page; | |
4702 | } | |
4703 | ||
4b91355e | 4704 | #ifdef CONFIG_SWAP |
90254a65 DN |
4705 | static struct page *mc_handle_swap_pte(struct vm_area_struct *vma, |
4706 | unsigned long addr, pte_t ptent, swp_entry_t *entry) | |
4707 | { | |
90254a65 DN |
4708 | struct page *page = NULL; |
4709 | swp_entry_t ent = pte_to_swp_entry(ptent); | |
4710 | ||
1dfab5ab | 4711 | if (!(mc.flags & MOVE_ANON) || non_swap_entry(ent)) |
90254a65 | 4712 | return NULL; |
4b91355e KH |
4713 | /* |
4714 | * Because lookup_swap_cache() updates some statistics counter, | |
4715 | * we call find_get_page() with swapper_space directly. | |
4716 | */ | |
33806f06 | 4717 | page = find_get_page(swap_address_space(ent), ent.val); |
90254a65 DN |
4718 | if (do_swap_account) |
4719 | entry->val = ent.val; | |
4720 | ||
4721 | return page; | |
4722 | } | |
4b91355e KH |
4723 | #else |
4724 | static struct page *mc_handle_swap_pte(struct vm_area_struct *vma, | |
4725 | unsigned long addr, pte_t ptent, swp_entry_t *entry) | |
4726 | { | |
4727 | return NULL; | |
4728 | } | |
4729 | #endif | |
90254a65 | 4730 | |
87946a72 DN |
4731 | static struct page *mc_handle_file_pte(struct vm_area_struct *vma, |
4732 | unsigned long addr, pte_t ptent, swp_entry_t *entry) | |
4733 | { | |
4734 | struct page *page = NULL; | |
87946a72 DN |
4735 | struct address_space *mapping; |
4736 | pgoff_t pgoff; | |
4737 | ||
4738 | if (!vma->vm_file) /* anonymous vma */ | |
4739 | return NULL; | |
1dfab5ab | 4740 | if (!(mc.flags & MOVE_FILE)) |
87946a72 DN |
4741 | return NULL; |
4742 | ||
87946a72 | 4743 | mapping = vma->vm_file->f_mapping; |
0661a336 | 4744 | pgoff = linear_page_index(vma, addr); |
87946a72 DN |
4745 | |
4746 | /* page is moved even if it's not RSS of this task(page-faulted). */ | |
aa3b1895 HD |
4747 | #ifdef CONFIG_SWAP |
4748 | /* shmem/tmpfs may report page out on swap: account for that too. */ | |
139b6a6f JW |
4749 | if (shmem_mapping(mapping)) { |
4750 | page = find_get_entry(mapping, pgoff); | |
4751 | if (radix_tree_exceptional_entry(page)) { | |
4752 | swp_entry_t swp = radix_to_swp_entry(page); | |
4753 | if (do_swap_account) | |
4754 | *entry = swp; | |
4755 | page = find_get_page(swap_address_space(swp), swp.val); | |
4756 | } | |
4757 | } else | |
4758 | page = find_get_page(mapping, pgoff); | |
4759 | #else | |
4760 | page = find_get_page(mapping, pgoff); | |
aa3b1895 | 4761 | #endif |
87946a72 DN |
4762 | return page; |
4763 | } | |
4764 | ||
8d32ff84 | 4765 | static enum mc_target_type get_mctgt_type(struct vm_area_struct *vma, |
90254a65 DN |
4766 | unsigned long addr, pte_t ptent, union mc_target *target) |
4767 | { | |
4768 | struct page *page = NULL; | |
8d32ff84 | 4769 | enum mc_target_type ret = MC_TARGET_NONE; |
90254a65 DN |
4770 | swp_entry_t ent = { .val = 0 }; |
4771 | ||
4772 | if (pte_present(ptent)) | |
4773 | page = mc_handle_present_pte(vma, addr, ptent); | |
4774 | else if (is_swap_pte(ptent)) | |
4775 | page = mc_handle_swap_pte(vma, addr, ptent, &ent); | |
0661a336 | 4776 | else if (pte_none(ptent)) |
87946a72 | 4777 | page = mc_handle_file_pte(vma, addr, ptent, &ent); |
90254a65 DN |
4778 | |
4779 | if (!page && !ent.val) | |
8d32ff84 | 4780 | return ret; |
02491447 | 4781 | if (page) { |
02491447 | 4782 | /* |
0a31bc97 | 4783 | * Do only loose check w/o serialization. |
1306a85a | 4784 | * mem_cgroup_move_account() checks the page is valid or |
0a31bc97 | 4785 | * not under LRU exclusion. |
02491447 | 4786 | */ |
1306a85a | 4787 | if (page->mem_cgroup == mc.from) { |
02491447 DN |
4788 | ret = MC_TARGET_PAGE; |
4789 | if (target) | |
4790 | target->page = page; | |
4791 | } | |
4792 | if (!ret || !target) | |
4793 | put_page(page); | |
4794 | } | |
90254a65 DN |
4795 | /* There is a swap entry and a page doesn't exist or isn't charged */ |
4796 | if (ent.val && !ret && | |
34c00c31 | 4797 | mem_cgroup_id(mc.from) == lookup_swap_cgroup_id(ent)) { |
7f0f1546 KH |
4798 | ret = MC_TARGET_SWAP; |
4799 | if (target) | |
4800 | target->ent = ent; | |
4ffef5fe | 4801 | } |
4ffef5fe DN |
4802 | return ret; |
4803 | } | |
4804 | ||
12724850 NH |
4805 | #ifdef CONFIG_TRANSPARENT_HUGEPAGE |
4806 | /* | |
4807 | * We don't consider swapping or file mapped pages because THP does not | |
4808 | * support them for now. | |
4809 | * Caller should make sure that pmd_trans_huge(pmd) is true. | |
4810 | */ | |
4811 | static enum mc_target_type get_mctgt_type_thp(struct vm_area_struct *vma, | |
4812 | unsigned long addr, pmd_t pmd, union mc_target *target) | |
4813 | { | |
4814 | struct page *page = NULL; | |
12724850 NH |
4815 | enum mc_target_type ret = MC_TARGET_NONE; |
4816 | ||
4817 | page = pmd_page(pmd); | |
309381fe | 4818 | VM_BUG_ON_PAGE(!page || !PageHead(page), page); |
1dfab5ab | 4819 | if (!(mc.flags & MOVE_ANON)) |
12724850 | 4820 | return ret; |
1306a85a | 4821 | if (page->mem_cgroup == mc.from) { |
12724850 NH |
4822 | ret = MC_TARGET_PAGE; |
4823 | if (target) { | |
4824 | get_page(page); | |
4825 | target->page = page; | |
4826 | } | |
4827 | } | |
4828 | return ret; | |
4829 | } | |
4830 | #else | |
4831 | static inline enum mc_target_type get_mctgt_type_thp(struct vm_area_struct *vma, | |
4832 | unsigned long addr, pmd_t pmd, union mc_target *target) | |
4833 | { | |
4834 | return MC_TARGET_NONE; | |
4835 | } | |
4836 | #endif | |
4837 | ||
4ffef5fe DN |
4838 | static int mem_cgroup_count_precharge_pte_range(pmd_t *pmd, |
4839 | unsigned long addr, unsigned long end, | |
4840 | struct mm_walk *walk) | |
4841 | { | |
4842 | struct vm_area_struct *vma = walk->private; | |
4843 | pte_t *pte; | |
4844 | spinlock_t *ptl; | |
4845 | ||
bf929152 | 4846 | if (pmd_trans_huge_lock(pmd, vma, &ptl) == 1) { |
12724850 NH |
4847 | if (get_mctgt_type_thp(vma, addr, *pmd, NULL) == MC_TARGET_PAGE) |
4848 | mc.precharge += HPAGE_PMD_NR; | |
bf929152 | 4849 | spin_unlock(ptl); |
1a5a9906 | 4850 | return 0; |
12724850 | 4851 | } |
03319327 | 4852 | |
45f83cef AA |
4853 | if (pmd_trans_unstable(pmd)) |
4854 | return 0; | |
4ffef5fe DN |
4855 | pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl); |
4856 | for (; addr != end; pte++, addr += PAGE_SIZE) | |
8d32ff84 | 4857 | if (get_mctgt_type(vma, addr, *pte, NULL)) |
4ffef5fe DN |
4858 | mc.precharge++; /* increment precharge temporarily */ |
4859 | pte_unmap_unlock(pte - 1, ptl); | |
4860 | cond_resched(); | |
4861 | ||
7dc74be0 DN |
4862 | return 0; |
4863 | } | |
4864 | ||
4ffef5fe DN |
4865 | static unsigned long mem_cgroup_count_precharge(struct mm_struct *mm) |
4866 | { | |
4867 | unsigned long precharge; | |
4868 | struct vm_area_struct *vma; | |
4869 | ||
dfe076b0 | 4870 | down_read(&mm->mmap_sem); |
4ffef5fe DN |
4871 | for (vma = mm->mmap; vma; vma = vma->vm_next) { |
4872 | struct mm_walk mem_cgroup_count_precharge_walk = { | |
4873 | .pmd_entry = mem_cgroup_count_precharge_pte_range, | |
4874 | .mm = mm, | |
4875 | .private = vma, | |
4876 | }; | |
4877 | if (is_vm_hugetlb_page(vma)) | |
4878 | continue; | |
4ffef5fe DN |
4879 | walk_page_range(vma->vm_start, vma->vm_end, |
4880 | &mem_cgroup_count_precharge_walk); | |
4881 | } | |
dfe076b0 | 4882 | up_read(&mm->mmap_sem); |
4ffef5fe DN |
4883 | |
4884 | precharge = mc.precharge; | |
4885 | mc.precharge = 0; | |
4886 | ||
4887 | return precharge; | |
4888 | } | |
4889 | ||
4ffef5fe DN |
4890 | static int mem_cgroup_precharge_mc(struct mm_struct *mm) |
4891 | { | |
dfe076b0 DN |
4892 | unsigned long precharge = mem_cgroup_count_precharge(mm); |
4893 | ||
4894 | VM_BUG_ON(mc.moving_task); | |
4895 | mc.moving_task = current; | |
4896 | return mem_cgroup_do_precharge(precharge); | |
4ffef5fe DN |
4897 | } |
4898 | ||
dfe076b0 DN |
4899 | /* cancels all extra charges on mc.from and mc.to, and wakes up all waiters. */ |
4900 | static void __mem_cgroup_clear_mc(void) | |
4ffef5fe | 4901 | { |
2bd9bb20 KH |
4902 | struct mem_cgroup *from = mc.from; |
4903 | struct mem_cgroup *to = mc.to; | |
4904 | ||
4ffef5fe | 4905 | /* we must uncharge all the leftover precharges from mc.to */ |
854ffa8d | 4906 | if (mc.precharge) { |
00501b53 | 4907 | cancel_charge(mc.to, mc.precharge); |
854ffa8d DN |
4908 | mc.precharge = 0; |
4909 | } | |
4910 | /* | |
4911 | * we didn't uncharge from mc.from at mem_cgroup_move_account(), so | |
4912 | * we must uncharge here. | |
4913 | */ | |
4914 | if (mc.moved_charge) { | |
00501b53 | 4915 | cancel_charge(mc.from, mc.moved_charge); |
854ffa8d | 4916 | mc.moved_charge = 0; |
4ffef5fe | 4917 | } |
483c30b5 DN |
4918 | /* we must fixup refcnts and charges */ |
4919 | if (mc.moved_swap) { | |
483c30b5 | 4920 | /* uncharge swap account from the old cgroup */ |
ce00a967 | 4921 | if (!mem_cgroup_is_root(mc.from)) |
3e32cb2e | 4922 | page_counter_uncharge(&mc.from->memsw, mc.moved_swap); |
483c30b5 | 4923 | |
05b84301 | 4924 | /* |
3e32cb2e JW |
4925 | * we charged both to->memory and to->memsw, so we |
4926 | * should uncharge to->memory. | |
05b84301 | 4927 | */ |
ce00a967 | 4928 | if (!mem_cgroup_is_root(mc.to)) |
3e32cb2e JW |
4929 | page_counter_uncharge(&mc.to->memory, mc.moved_swap); |
4930 | ||
e8ea14cc | 4931 | css_put_many(&mc.from->css, mc.moved_swap); |
3e32cb2e | 4932 | |
4050377b | 4933 | /* we've already done css_get(mc.to) */ |
483c30b5 DN |
4934 | mc.moved_swap = 0; |
4935 | } | |
dfe076b0 DN |
4936 | memcg_oom_recover(from); |
4937 | memcg_oom_recover(to); | |
4938 | wake_up_all(&mc.waitq); | |
4939 | } | |
4940 | ||
4941 | static void mem_cgroup_clear_mc(void) | |
4942 | { | |
dfe076b0 DN |
4943 | /* |
4944 | * we must clear moving_task before waking up waiters at the end of | |
4945 | * task migration. | |
4946 | */ | |
4947 | mc.moving_task = NULL; | |
4948 | __mem_cgroup_clear_mc(); | |
2bd9bb20 | 4949 | spin_lock(&mc.lock); |
4ffef5fe DN |
4950 | mc.from = NULL; |
4951 | mc.to = NULL; | |
2bd9bb20 | 4952 | spin_unlock(&mc.lock); |
4ffef5fe DN |
4953 | } |
4954 | ||
eb95419b | 4955 | static int mem_cgroup_can_attach(struct cgroup_subsys_state *css, |
761b3ef5 | 4956 | struct cgroup_taskset *tset) |
7dc74be0 | 4957 | { |
2f7ee569 | 4958 | struct task_struct *p = cgroup_taskset_first(tset); |
7dc74be0 | 4959 | int ret = 0; |
eb95419b | 4960 | struct mem_cgroup *memcg = mem_cgroup_from_css(css); |
1dfab5ab | 4961 | unsigned long move_flags; |
7dc74be0 | 4962 | |
ee5e8472 GC |
4963 | /* |
4964 | * We are now commited to this value whatever it is. Changes in this | |
4965 | * tunable will only affect upcoming migrations, not the current one. | |
4966 | * So we need to save it, and keep it going. | |
4967 | */ | |
1dfab5ab JW |
4968 | move_flags = ACCESS_ONCE(memcg->move_charge_at_immigrate); |
4969 | if (move_flags) { | |
7dc74be0 DN |
4970 | struct mm_struct *mm; |
4971 | struct mem_cgroup *from = mem_cgroup_from_task(p); | |
4972 | ||
c0ff4b85 | 4973 | VM_BUG_ON(from == memcg); |
7dc74be0 DN |
4974 | |
4975 | mm = get_task_mm(p); | |
4976 | if (!mm) | |
4977 | return 0; | |
7dc74be0 | 4978 | /* We move charges only when we move a owner of the mm */ |
4ffef5fe DN |
4979 | if (mm->owner == p) { |
4980 | VM_BUG_ON(mc.from); | |
4981 | VM_BUG_ON(mc.to); | |
4982 | VM_BUG_ON(mc.precharge); | |
854ffa8d | 4983 | VM_BUG_ON(mc.moved_charge); |
483c30b5 | 4984 | VM_BUG_ON(mc.moved_swap); |
247b1447 | 4985 | |
2bd9bb20 | 4986 | spin_lock(&mc.lock); |
4ffef5fe | 4987 | mc.from = from; |
c0ff4b85 | 4988 | mc.to = memcg; |
1dfab5ab | 4989 | mc.flags = move_flags; |
2bd9bb20 | 4990 | spin_unlock(&mc.lock); |
dfe076b0 | 4991 | /* We set mc.moving_task later */ |
4ffef5fe DN |
4992 | |
4993 | ret = mem_cgroup_precharge_mc(mm); | |
4994 | if (ret) | |
4995 | mem_cgroup_clear_mc(); | |
dfe076b0 DN |
4996 | } |
4997 | mmput(mm); | |
7dc74be0 DN |
4998 | } |
4999 | return ret; | |
5000 | } | |
5001 | ||
eb95419b | 5002 | static void mem_cgroup_cancel_attach(struct cgroup_subsys_state *css, |
761b3ef5 | 5003 | struct cgroup_taskset *tset) |
7dc74be0 | 5004 | { |
4e2f245d JW |
5005 | if (mc.to) |
5006 | mem_cgroup_clear_mc(); | |
7dc74be0 DN |
5007 | } |
5008 | ||
4ffef5fe DN |
5009 | static int mem_cgroup_move_charge_pte_range(pmd_t *pmd, |
5010 | unsigned long addr, unsigned long end, | |
5011 | struct mm_walk *walk) | |
7dc74be0 | 5012 | { |
4ffef5fe DN |
5013 | int ret = 0; |
5014 | struct vm_area_struct *vma = walk->private; | |
5015 | pte_t *pte; | |
5016 | spinlock_t *ptl; | |
12724850 NH |
5017 | enum mc_target_type target_type; |
5018 | union mc_target target; | |
5019 | struct page *page; | |
4ffef5fe | 5020 | |
12724850 NH |
5021 | /* |
5022 | * We don't take compound_lock() here but no race with splitting thp | |
5023 | * happens because: | |
5024 | * - if pmd_trans_huge_lock() returns 1, the relevant thp is not | |
5025 | * under splitting, which means there's no concurrent thp split, | |
5026 | * - if another thread runs into split_huge_page() just after we | |
5027 | * entered this if-block, the thread must wait for page table lock | |
5028 | * to be unlocked in __split_huge_page_splitting(), where the main | |
5029 | * part of thp split is not executed yet. | |
5030 | */ | |
bf929152 | 5031 | if (pmd_trans_huge_lock(pmd, vma, &ptl) == 1) { |
62ade86a | 5032 | if (mc.precharge < HPAGE_PMD_NR) { |
bf929152 | 5033 | spin_unlock(ptl); |
12724850 NH |
5034 | return 0; |
5035 | } | |
5036 | target_type = get_mctgt_type_thp(vma, addr, *pmd, &target); | |
5037 | if (target_type == MC_TARGET_PAGE) { | |
5038 | page = target.page; | |
5039 | if (!isolate_lru_page(page)) { | |
12724850 | 5040 | if (!mem_cgroup_move_account(page, HPAGE_PMD_NR, |
1306a85a | 5041 | mc.from, mc.to)) { |
12724850 NH |
5042 | mc.precharge -= HPAGE_PMD_NR; |
5043 | mc.moved_charge += HPAGE_PMD_NR; | |
5044 | } | |
5045 | putback_lru_page(page); | |
5046 | } | |
5047 | put_page(page); | |
5048 | } | |
bf929152 | 5049 | spin_unlock(ptl); |
1a5a9906 | 5050 | return 0; |
12724850 NH |
5051 | } |
5052 | ||
45f83cef AA |
5053 | if (pmd_trans_unstable(pmd)) |
5054 | return 0; | |
4ffef5fe DN |
5055 | retry: |
5056 | pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl); | |
5057 | for (; addr != end; addr += PAGE_SIZE) { | |
5058 | pte_t ptent = *(pte++); | |
02491447 | 5059 | swp_entry_t ent; |
4ffef5fe DN |
5060 | |
5061 | if (!mc.precharge) | |
5062 | break; | |
5063 | ||
8d32ff84 | 5064 | switch (get_mctgt_type(vma, addr, ptent, &target)) { |
4ffef5fe DN |
5065 | case MC_TARGET_PAGE: |
5066 | page = target.page; | |
5067 | if (isolate_lru_page(page)) | |
5068 | goto put; | |
1306a85a | 5069 | if (!mem_cgroup_move_account(page, 1, mc.from, mc.to)) { |
4ffef5fe | 5070 | mc.precharge--; |
854ffa8d DN |
5071 | /* we uncharge from mc.from later. */ |
5072 | mc.moved_charge++; | |
4ffef5fe DN |
5073 | } |
5074 | putback_lru_page(page); | |
8d32ff84 | 5075 | put: /* get_mctgt_type() gets the page */ |
4ffef5fe DN |
5076 | put_page(page); |
5077 | break; | |
02491447 DN |
5078 | case MC_TARGET_SWAP: |
5079 | ent = target.ent; | |
e91cbb42 | 5080 | if (!mem_cgroup_move_swap_account(ent, mc.from, mc.to)) { |
02491447 | 5081 | mc.precharge--; |
483c30b5 DN |
5082 | /* we fixup refcnts and charges later. */ |
5083 | mc.moved_swap++; | |
5084 | } | |
02491447 | 5085 | break; |
4ffef5fe DN |
5086 | default: |
5087 | break; | |
5088 | } | |
5089 | } | |
5090 | pte_unmap_unlock(pte - 1, ptl); | |
5091 | cond_resched(); | |
5092 | ||
5093 | if (addr != end) { | |
5094 | /* | |
5095 | * We have consumed all precharges we got in can_attach(). | |
5096 | * We try charge one by one, but don't do any additional | |
5097 | * charges to mc.to if we have failed in charge once in attach() | |
5098 | * phase. | |
5099 | */ | |
854ffa8d | 5100 | ret = mem_cgroup_do_precharge(1); |
4ffef5fe DN |
5101 | if (!ret) |
5102 | goto retry; | |
5103 | } | |
5104 | ||
5105 | return ret; | |
5106 | } | |
5107 | ||
5108 | static void mem_cgroup_move_charge(struct mm_struct *mm) | |
5109 | { | |
5110 | struct vm_area_struct *vma; | |
5111 | ||
5112 | lru_add_drain_all(); | |
312722cb JW |
5113 | /* |
5114 | * Signal mem_cgroup_begin_page_stat() to take the memcg's | |
5115 | * move_lock while we're moving its pages to another memcg. | |
5116 | * Then wait for already started RCU-only updates to finish. | |
5117 | */ | |
5118 | atomic_inc(&mc.from->moving_account); | |
5119 | synchronize_rcu(); | |
dfe076b0 DN |
5120 | retry: |
5121 | if (unlikely(!down_read_trylock(&mm->mmap_sem))) { | |
5122 | /* | |
5123 | * Someone who are holding the mmap_sem might be waiting in | |
5124 | * waitq. So we cancel all extra charges, wake up all waiters, | |
5125 | * and retry. Because we cancel precharges, we might not be able | |
5126 | * to move enough charges, but moving charge is a best-effort | |
5127 | * feature anyway, so it wouldn't be a big problem. | |
5128 | */ | |
5129 | __mem_cgroup_clear_mc(); | |
5130 | cond_resched(); | |
5131 | goto retry; | |
5132 | } | |
4ffef5fe DN |
5133 | for (vma = mm->mmap; vma; vma = vma->vm_next) { |
5134 | int ret; | |
5135 | struct mm_walk mem_cgroup_move_charge_walk = { | |
5136 | .pmd_entry = mem_cgroup_move_charge_pte_range, | |
5137 | .mm = mm, | |
5138 | .private = vma, | |
5139 | }; | |
5140 | if (is_vm_hugetlb_page(vma)) | |
5141 | continue; | |
4ffef5fe DN |
5142 | ret = walk_page_range(vma->vm_start, vma->vm_end, |
5143 | &mem_cgroup_move_charge_walk); | |
5144 | if (ret) | |
5145 | /* | |
5146 | * means we have consumed all precharges and failed in | |
5147 | * doing additional charge. Just abandon here. | |
5148 | */ | |
5149 | break; | |
5150 | } | |
dfe076b0 | 5151 | up_read(&mm->mmap_sem); |
312722cb | 5152 | atomic_dec(&mc.from->moving_account); |
7dc74be0 DN |
5153 | } |
5154 | ||
eb95419b | 5155 | static void mem_cgroup_move_task(struct cgroup_subsys_state *css, |
761b3ef5 | 5156 | struct cgroup_taskset *tset) |
67e465a7 | 5157 | { |
2f7ee569 | 5158 | struct task_struct *p = cgroup_taskset_first(tset); |
a433658c | 5159 | struct mm_struct *mm = get_task_mm(p); |
dfe076b0 | 5160 | |
dfe076b0 | 5161 | if (mm) { |
a433658c KM |
5162 | if (mc.to) |
5163 | mem_cgroup_move_charge(mm); | |
dfe076b0 DN |
5164 | mmput(mm); |
5165 | } | |
a433658c KM |
5166 | if (mc.to) |
5167 | mem_cgroup_clear_mc(); | |
67e465a7 | 5168 | } |
5cfb80a7 | 5169 | #else /* !CONFIG_MMU */ |
eb95419b | 5170 | static int mem_cgroup_can_attach(struct cgroup_subsys_state *css, |
761b3ef5 | 5171 | struct cgroup_taskset *tset) |
5cfb80a7 DN |
5172 | { |
5173 | return 0; | |
5174 | } | |
eb95419b | 5175 | static void mem_cgroup_cancel_attach(struct cgroup_subsys_state *css, |
761b3ef5 | 5176 | struct cgroup_taskset *tset) |
5cfb80a7 DN |
5177 | { |
5178 | } | |
eb95419b | 5179 | static void mem_cgroup_move_task(struct cgroup_subsys_state *css, |
761b3ef5 | 5180 | struct cgroup_taskset *tset) |
5cfb80a7 DN |
5181 | { |
5182 | } | |
5183 | #endif | |
67e465a7 | 5184 | |
f00baae7 TH |
5185 | /* |
5186 | * Cgroup retains root cgroups across [un]mount cycles making it necessary | |
aa6ec29b TH |
5187 | * to verify whether we're attached to the default hierarchy on each mount |
5188 | * attempt. | |
f00baae7 | 5189 | */ |
eb95419b | 5190 | static void mem_cgroup_bind(struct cgroup_subsys_state *root_css) |
f00baae7 TH |
5191 | { |
5192 | /* | |
aa6ec29b | 5193 | * use_hierarchy is forced on the default hierarchy. cgroup core |
f00baae7 TH |
5194 | * guarantees that @root doesn't have any children, so turning it |
5195 | * on for the root memcg is enough. | |
5196 | */ | |
aa6ec29b | 5197 | if (cgroup_on_dfl(root_css->cgroup)) |
eb95419b | 5198 | mem_cgroup_from_css(root_css)->use_hierarchy = true; |
f00baae7 TH |
5199 | } |
5200 | ||
241994ed JW |
5201 | static u64 memory_current_read(struct cgroup_subsys_state *css, |
5202 | struct cftype *cft) | |
5203 | { | |
5204 | return mem_cgroup_usage(mem_cgroup_from_css(css), false); | |
5205 | } | |
5206 | ||
5207 | static int memory_low_show(struct seq_file *m, void *v) | |
5208 | { | |
5209 | struct mem_cgroup *memcg = mem_cgroup_from_css(seq_css(m)); | |
5210 | unsigned long low = ACCESS_ONCE(memcg->low); | |
5211 | ||
5212 | if (low == PAGE_COUNTER_MAX) | |
5213 | seq_puts(m, "infinity\n"); | |
5214 | else | |
5215 | seq_printf(m, "%llu\n", (u64)low * PAGE_SIZE); | |
5216 | ||
5217 | return 0; | |
5218 | } | |
5219 | ||
5220 | static ssize_t memory_low_write(struct kernfs_open_file *of, | |
5221 | char *buf, size_t nbytes, loff_t off) | |
5222 | { | |
5223 | struct mem_cgroup *memcg = mem_cgroup_from_css(of_css(of)); | |
5224 | unsigned long low; | |
5225 | int err; | |
5226 | ||
5227 | buf = strstrip(buf); | |
5228 | err = page_counter_memparse(buf, "infinity", &low); | |
5229 | if (err) | |
5230 | return err; | |
5231 | ||
5232 | memcg->low = low; | |
5233 | ||
5234 | return nbytes; | |
5235 | } | |
5236 | ||
5237 | static int memory_high_show(struct seq_file *m, void *v) | |
5238 | { | |
5239 | struct mem_cgroup *memcg = mem_cgroup_from_css(seq_css(m)); | |
5240 | unsigned long high = ACCESS_ONCE(memcg->high); | |
5241 | ||
5242 | if (high == PAGE_COUNTER_MAX) | |
5243 | seq_puts(m, "infinity\n"); | |
5244 | else | |
5245 | seq_printf(m, "%llu\n", (u64)high * PAGE_SIZE); | |
5246 | ||
5247 | return 0; | |
5248 | } | |
5249 | ||
5250 | static ssize_t memory_high_write(struct kernfs_open_file *of, | |
5251 | char *buf, size_t nbytes, loff_t off) | |
5252 | { | |
5253 | struct mem_cgroup *memcg = mem_cgroup_from_css(of_css(of)); | |
5254 | unsigned long high; | |
5255 | int err; | |
5256 | ||
5257 | buf = strstrip(buf); | |
5258 | err = page_counter_memparse(buf, "infinity", &high); | |
5259 | if (err) | |
5260 | return err; | |
5261 | ||
5262 | memcg->high = high; | |
5263 | ||
5264 | return nbytes; | |
5265 | } | |
5266 | ||
5267 | static int memory_max_show(struct seq_file *m, void *v) | |
5268 | { | |
5269 | struct mem_cgroup *memcg = mem_cgroup_from_css(seq_css(m)); | |
5270 | unsigned long max = ACCESS_ONCE(memcg->memory.limit); | |
5271 | ||
5272 | if (max == PAGE_COUNTER_MAX) | |
5273 | seq_puts(m, "infinity\n"); | |
5274 | else | |
5275 | seq_printf(m, "%llu\n", (u64)max * PAGE_SIZE); | |
5276 | ||
5277 | return 0; | |
5278 | } | |
5279 | ||
5280 | static ssize_t memory_max_write(struct kernfs_open_file *of, | |
5281 | char *buf, size_t nbytes, loff_t off) | |
5282 | { | |
5283 | struct mem_cgroup *memcg = mem_cgroup_from_css(of_css(of)); | |
5284 | unsigned long max; | |
5285 | int err; | |
5286 | ||
5287 | buf = strstrip(buf); | |
5288 | err = page_counter_memparse(buf, "infinity", &max); | |
5289 | if (err) | |
5290 | return err; | |
5291 | ||
5292 | err = mem_cgroup_resize_limit(memcg, max); | |
5293 | if (err) | |
5294 | return err; | |
5295 | ||
5296 | return nbytes; | |
5297 | } | |
5298 | ||
5299 | static int memory_events_show(struct seq_file *m, void *v) | |
5300 | { | |
5301 | struct mem_cgroup *memcg = mem_cgroup_from_css(seq_css(m)); | |
5302 | ||
5303 | seq_printf(m, "low %lu\n", mem_cgroup_read_events(memcg, MEMCG_LOW)); | |
5304 | seq_printf(m, "high %lu\n", mem_cgroup_read_events(memcg, MEMCG_HIGH)); | |
5305 | seq_printf(m, "max %lu\n", mem_cgroup_read_events(memcg, MEMCG_MAX)); | |
5306 | seq_printf(m, "oom %lu\n", mem_cgroup_read_events(memcg, MEMCG_OOM)); | |
5307 | ||
5308 | return 0; | |
5309 | } | |
5310 | ||
5311 | static struct cftype memory_files[] = { | |
5312 | { | |
5313 | .name = "current", | |
5314 | .read_u64 = memory_current_read, | |
5315 | }, | |
5316 | { | |
5317 | .name = "low", | |
5318 | .flags = CFTYPE_NOT_ON_ROOT, | |
5319 | .seq_show = memory_low_show, | |
5320 | .write = memory_low_write, | |
5321 | }, | |
5322 | { | |
5323 | .name = "high", | |
5324 | .flags = CFTYPE_NOT_ON_ROOT, | |
5325 | .seq_show = memory_high_show, | |
5326 | .write = memory_high_write, | |
5327 | }, | |
5328 | { | |
5329 | .name = "max", | |
5330 | .flags = CFTYPE_NOT_ON_ROOT, | |
5331 | .seq_show = memory_max_show, | |
5332 | .write = memory_max_write, | |
5333 | }, | |
5334 | { | |
5335 | .name = "events", | |
5336 | .flags = CFTYPE_NOT_ON_ROOT, | |
5337 | .seq_show = memory_events_show, | |
5338 | }, | |
5339 | { } /* terminate */ | |
5340 | }; | |
5341 | ||
073219e9 | 5342 | struct cgroup_subsys memory_cgrp_subsys = { |
92fb9748 | 5343 | .css_alloc = mem_cgroup_css_alloc, |
d142e3e6 | 5344 | .css_online = mem_cgroup_css_online, |
92fb9748 TH |
5345 | .css_offline = mem_cgroup_css_offline, |
5346 | .css_free = mem_cgroup_css_free, | |
1ced953b | 5347 | .css_reset = mem_cgroup_css_reset, |
7dc74be0 DN |
5348 | .can_attach = mem_cgroup_can_attach, |
5349 | .cancel_attach = mem_cgroup_cancel_attach, | |
67e465a7 | 5350 | .attach = mem_cgroup_move_task, |
f00baae7 | 5351 | .bind = mem_cgroup_bind, |
241994ed JW |
5352 | .dfl_cftypes = memory_files, |
5353 | .legacy_cftypes = mem_cgroup_legacy_files, | |
6d12e2d8 | 5354 | .early_init = 0, |
8cdea7c0 | 5355 | }; |
c077719b | 5356 | |
241994ed JW |
5357 | /** |
5358 | * mem_cgroup_events - count memory events against a cgroup | |
5359 | * @memcg: the memory cgroup | |
5360 | * @idx: the event index | |
5361 | * @nr: the number of events to account for | |
5362 | */ | |
5363 | void mem_cgroup_events(struct mem_cgroup *memcg, | |
5364 | enum mem_cgroup_events_index idx, | |
5365 | unsigned int nr) | |
5366 | { | |
5367 | this_cpu_add(memcg->stat->events[idx], nr); | |
5368 | } | |
5369 | ||
5370 | /** | |
5371 | * mem_cgroup_low - check if memory consumption is below the normal range | |
5372 | * @root: the highest ancestor to consider | |
5373 | * @memcg: the memory cgroup to check | |
5374 | * | |
5375 | * Returns %true if memory consumption of @memcg, and that of all | |
5376 | * configurable ancestors up to @root, is below the normal range. | |
5377 | */ | |
5378 | bool mem_cgroup_low(struct mem_cgroup *root, struct mem_cgroup *memcg) | |
5379 | { | |
5380 | if (mem_cgroup_disabled()) | |
5381 | return false; | |
5382 | ||
5383 | /* | |
5384 | * The toplevel group doesn't have a configurable range, so | |
5385 | * it's never low when looked at directly, and it is not | |
5386 | * considered an ancestor when assessing the hierarchy. | |
5387 | */ | |
5388 | ||
5389 | if (memcg == root_mem_cgroup) | |
5390 | return false; | |
5391 | ||
5392 | if (page_counter_read(&memcg->memory) > memcg->low) | |
5393 | return false; | |
5394 | ||
5395 | while (memcg != root) { | |
5396 | memcg = parent_mem_cgroup(memcg); | |
5397 | ||
5398 | if (memcg == root_mem_cgroup) | |
5399 | break; | |
5400 | ||
5401 | if (page_counter_read(&memcg->memory) > memcg->low) | |
5402 | return false; | |
5403 | } | |
5404 | return true; | |
5405 | } | |
5406 | ||
00501b53 JW |
5407 | /** |
5408 | * mem_cgroup_try_charge - try charging a page | |
5409 | * @page: page to charge | |
5410 | * @mm: mm context of the victim | |
5411 | * @gfp_mask: reclaim mode | |
5412 | * @memcgp: charged memcg return | |
5413 | * | |
5414 | * Try to charge @page to the memcg that @mm belongs to, reclaiming | |
5415 | * pages according to @gfp_mask if necessary. | |
5416 | * | |
5417 | * Returns 0 on success, with *@memcgp pointing to the charged memcg. | |
5418 | * Otherwise, an error code is returned. | |
5419 | * | |
5420 | * After page->mapping has been set up, the caller must finalize the | |
5421 | * charge with mem_cgroup_commit_charge(). Or abort the transaction | |
5422 | * with mem_cgroup_cancel_charge() in case page instantiation fails. | |
5423 | */ | |
5424 | int mem_cgroup_try_charge(struct page *page, struct mm_struct *mm, | |
5425 | gfp_t gfp_mask, struct mem_cgroup **memcgp) | |
5426 | { | |
5427 | struct mem_cgroup *memcg = NULL; | |
5428 | unsigned int nr_pages = 1; | |
5429 | int ret = 0; | |
5430 | ||
5431 | if (mem_cgroup_disabled()) | |
5432 | goto out; | |
5433 | ||
5434 | if (PageSwapCache(page)) { | |
00501b53 JW |
5435 | /* |
5436 | * Every swap fault against a single page tries to charge the | |
5437 | * page, bail as early as possible. shmem_unuse() encounters | |
5438 | * already charged pages, too. The USED bit is protected by | |
5439 | * the page lock, which serializes swap cache removal, which | |
5440 | * in turn serializes uncharging. | |
5441 | */ | |
1306a85a | 5442 | if (page->mem_cgroup) |
00501b53 JW |
5443 | goto out; |
5444 | } | |
5445 | ||
5446 | if (PageTransHuge(page)) { | |
5447 | nr_pages <<= compound_order(page); | |
5448 | VM_BUG_ON_PAGE(!PageTransHuge(page), page); | |
5449 | } | |
5450 | ||
5451 | if (do_swap_account && PageSwapCache(page)) | |
5452 | memcg = try_get_mem_cgroup_from_page(page); | |
5453 | if (!memcg) | |
5454 | memcg = get_mem_cgroup_from_mm(mm); | |
5455 | ||
5456 | ret = try_charge(memcg, gfp_mask, nr_pages); | |
5457 | ||
5458 | css_put(&memcg->css); | |
5459 | ||
5460 | if (ret == -EINTR) { | |
5461 | memcg = root_mem_cgroup; | |
5462 | ret = 0; | |
5463 | } | |
5464 | out: | |
5465 | *memcgp = memcg; | |
5466 | return ret; | |
5467 | } | |
5468 | ||
5469 | /** | |
5470 | * mem_cgroup_commit_charge - commit a page charge | |
5471 | * @page: page to charge | |
5472 | * @memcg: memcg to charge the page to | |
5473 | * @lrucare: page might be on LRU already | |
5474 | * | |
5475 | * Finalize a charge transaction started by mem_cgroup_try_charge(), | |
5476 | * after page->mapping has been set up. This must happen atomically | |
5477 | * as part of the page instantiation, i.e. under the page table lock | |
5478 | * for anonymous pages, under the page lock for page and swap cache. | |
5479 | * | |
5480 | * In addition, the page must not be on the LRU during the commit, to | |
5481 | * prevent racing with task migration. If it might be, use @lrucare. | |
5482 | * | |
5483 | * Use mem_cgroup_cancel_charge() to cancel the transaction instead. | |
5484 | */ | |
5485 | void mem_cgroup_commit_charge(struct page *page, struct mem_cgroup *memcg, | |
5486 | bool lrucare) | |
5487 | { | |
5488 | unsigned int nr_pages = 1; | |
5489 | ||
5490 | VM_BUG_ON_PAGE(!page->mapping, page); | |
5491 | VM_BUG_ON_PAGE(PageLRU(page) && !lrucare, page); | |
5492 | ||
5493 | if (mem_cgroup_disabled()) | |
5494 | return; | |
5495 | /* | |
5496 | * Swap faults will attempt to charge the same page multiple | |
5497 | * times. But reuse_swap_page() might have removed the page | |
5498 | * from swapcache already, so we can't check PageSwapCache(). | |
5499 | */ | |
5500 | if (!memcg) | |
5501 | return; | |
5502 | ||
6abb5a86 JW |
5503 | commit_charge(page, memcg, lrucare); |
5504 | ||
00501b53 JW |
5505 | if (PageTransHuge(page)) { |
5506 | nr_pages <<= compound_order(page); | |
5507 | VM_BUG_ON_PAGE(!PageTransHuge(page), page); | |
5508 | } | |
5509 | ||
6abb5a86 JW |
5510 | local_irq_disable(); |
5511 | mem_cgroup_charge_statistics(memcg, page, nr_pages); | |
5512 | memcg_check_events(memcg, page); | |
5513 | local_irq_enable(); | |
00501b53 JW |
5514 | |
5515 | if (do_swap_account && PageSwapCache(page)) { | |
5516 | swp_entry_t entry = { .val = page_private(page) }; | |
5517 | /* | |
5518 | * The swap entry might not get freed for a long time, | |
5519 | * let's not wait for it. The page already received a | |
5520 | * memory+swap charge, drop the swap entry duplicate. | |
5521 | */ | |
5522 | mem_cgroup_uncharge_swap(entry); | |
5523 | } | |
5524 | } | |
5525 | ||
5526 | /** | |
5527 | * mem_cgroup_cancel_charge - cancel a page charge | |
5528 | * @page: page to charge | |
5529 | * @memcg: memcg to charge the page to | |
5530 | * | |
5531 | * Cancel a charge transaction started by mem_cgroup_try_charge(). | |
5532 | */ | |
5533 | void mem_cgroup_cancel_charge(struct page *page, struct mem_cgroup *memcg) | |
5534 | { | |
5535 | unsigned int nr_pages = 1; | |
5536 | ||
5537 | if (mem_cgroup_disabled()) | |
5538 | return; | |
5539 | /* | |
5540 | * Swap faults will attempt to charge the same page multiple | |
5541 | * times. But reuse_swap_page() might have removed the page | |
5542 | * from swapcache already, so we can't check PageSwapCache(). | |
5543 | */ | |
5544 | if (!memcg) | |
5545 | return; | |
5546 | ||
5547 | if (PageTransHuge(page)) { | |
5548 | nr_pages <<= compound_order(page); | |
5549 | VM_BUG_ON_PAGE(!PageTransHuge(page), page); | |
5550 | } | |
5551 | ||
5552 | cancel_charge(memcg, nr_pages); | |
5553 | } | |
5554 | ||
747db954 | 5555 | static void uncharge_batch(struct mem_cgroup *memcg, unsigned long pgpgout, |
747db954 JW |
5556 | unsigned long nr_anon, unsigned long nr_file, |
5557 | unsigned long nr_huge, struct page *dummy_page) | |
5558 | { | |
18eca2e6 | 5559 | unsigned long nr_pages = nr_anon + nr_file; |
747db954 JW |
5560 | unsigned long flags; |
5561 | ||
ce00a967 | 5562 | if (!mem_cgroup_is_root(memcg)) { |
18eca2e6 JW |
5563 | page_counter_uncharge(&memcg->memory, nr_pages); |
5564 | if (do_swap_account) | |
5565 | page_counter_uncharge(&memcg->memsw, nr_pages); | |
ce00a967 JW |
5566 | memcg_oom_recover(memcg); |
5567 | } | |
747db954 JW |
5568 | |
5569 | local_irq_save(flags); | |
5570 | __this_cpu_sub(memcg->stat->count[MEM_CGROUP_STAT_RSS], nr_anon); | |
5571 | __this_cpu_sub(memcg->stat->count[MEM_CGROUP_STAT_CACHE], nr_file); | |
5572 | __this_cpu_sub(memcg->stat->count[MEM_CGROUP_STAT_RSS_HUGE], nr_huge); | |
5573 | __this_cpu_add(memcg->stat->events[MEM_CGROUP_EVENTS_PGPGOUT], pgpgout); | |
18eca2e6 | 5574 | __this_cpu_add(memcg->stat->nr_page_events, nr_pages); |
747db954 JW |
5575 | memcg_check_events(memcg, dummy_page); |
5576 | local_irq_restore(flags); | |
e8ea14cc JW |
5577 | |
5578 | if (!mem_cgroup_is_root(memcg)) | |
18eca2e6 | 5579 | css_put_many(&memcg->css, nr_pages); |
747db954 JW |
5580 | } |
5581 | ||
5582 | static void uncharge_list(struct list_head *page_list) | |
5583 | { | |
5584 | struct mem_cgroup *memcg = NULL; | |
747db954 JW |
5585 | unsigned long nr_anon = 0; |
5586 | unsigned long nr_file = 0; | |
5587 | unsigned long nr_huge = 0; | |
5588 | unsigned long pgpgout = 0; | |
747db954 JW |
5589 | struct list_head *next; |
5590 | struct page *page; | |
5591 | ||
5592 | next = page_list->next; | |
5593 | do { | |
5594 | unsigned int nr_pages = 1; | |
747db954 JW |
5595 | |
5596 | page = list_entry(next, struct page, lru); | |
5597 | next = page->lru.next; | |
5598 | ||
5599 | VM_BUG_ON_PAGE(PageLRU(page), page); | |
5600 | VM_BUG_ON_PAGE(page_count(page), page); | |
5601 | ||
1306a85a | 5602 | if (!page->mem_cgroup) |
747db954 JW |
5603 | continue; |
5604 | ||
5605 | /* | |
5606 | * Nobody should be changing or seriously looking at | |
1306a85a | 5607 | * page->mem_cgroup at this point, we have fully |
29833315 | 5608 | * exclusive access to the page. |
747db954 JW |
5609 | */ |
5610 | ||
1306a85a | 5611 | if (memcg != page->mem_cgroup) { |
747db954 | 5612 | if (memcg) { |
18eca2e6 JW |
5613 | uncharge_batch(memcg, pgpgout, nr_anon, nr_file, |
5614 | nr_huge, page); | |
5615 | pgpgout = nr_anon = nr_file = nr_huge = 0; | |
747db954 | 5616 | } |
1306a85a | 5617 | memcg = page->mem_cgroup; |
747db954 JW |
5618 | } |
5619 | ||
5620 | if (PageTransHuge(page)) { | |
5621 | nr_pages <<= compound_order(page); | |
5622 | VM_BUG_ON_PAGE(!PageTransHuge(page), page); | |
5623 | nr_huge += nr_pages; | |
5624 | } | |
5625 | ||
5626 | if (PageAnon(page)) | |
5627 | nr_anon += nr_pages; | |
5628 | else | |
5629 | nr_file += nr_pages; | |
5630 | ||
1306a85a | 5631 | page->mem_cgroup = NULL; |
747db954 JW |
5632 | |
5633 | pgpgout++; | |
5634 | } while (next != page_list); | |
5635 | ||
5636 | if (memcg) | |
18eca2e6 JW |
5637 | uncharge_batch(memcg, pgpgout, nr_anon, nr_file, |
5638 | nr_huge, page); | |
747db954 JW |
5639 | } |
5640 | ||
0a31bc97 JW |
5641 | /** |
5642 | * mem_cgroup_uncharge - uncharge a page | |
5643 | * @page: page to uncharge | |
5644 | * | |
5645 | * Uncharge a page previously charged with mem_cgroup_try_charge() and | |
5646 | * mem_cgroup_commit_charge(). | |
5647 | */ | |
5648 | void mem_cgroup_uncharge(struct page *page) | |
5649 | { | |
0a31bc97 JW |
5650 | if (mem_cgroup_disabled()) |
5651 | return; | |
5652 | ||
747db954 | 5653 | /* Don't touch page->lru of any random page, pre-check: */ |
1306a85a | 5654 | if (!page->mem_cgroup) |
0a31bc97 JW |
5655 | return; |
5656 | ||
747db954 JW |
5657 | INIT_LIST_HEAD(&page->lru); |
5658 | uncharge_list(&page->lru); | |
5659 | } | |
0a31bc97 | 5660 | |
747db954 JW |
5661 | /** |
5662 | * mem_cgroup_uncharge_list - uncharge a list of page | |
5663 | * @page_list: list of pages to uncharge | |
5664 | * | |
5665 | * Uncharge a list of pages previously charged with | |
5666 | * mem_cgroup_try_charge() and mem_cgroup_commit_charge(). | |
5667 | */ | |
5668 | void mem_cgroup_uncharge_list(struct list_head *page_list) | |
5669 | { | |
5670 | if (mem_cgroup_disabled()) | |
5671 | return; | |
0a31bc97 | 5672 | |
747db954 JW |
5673 | if (!list_empty(page_list)) |
5674 | uncharge_list(page_list); | |
0a31bc97 JW |
5675 | } |
5676 | ||
5677 | /** | |
5678 | * mem_cgroup_migrate - migrate a charge to another page | |
5679 | * @oldpage: currently charged page | |
5680 | * @newpage: page to transfer the charge to | |
f5e03a49 | 5681 | * @lrucare: either or both pages might be on the LRU already |
0a31bc97 JW |
5682 | * |
5683 | * Migrate the charge from @oldpage to @newpage. | |
5684 | * | |
5685 | * Both pages must be locked, @newpage->mapping must be set up. | |
5686 | */ | |
5687 | void mem_cgroup_migrate(struct page *oldpage, struct page *newpage, | |
5688 | bool lrucare) | |
5689 | { | |
29833315 | 5690 | struct mem_cgroup *memcg; |
0a31bc97 JW |
5691 | int isolated; |
5692 | ||
5693 | VM_BUG_ON_PAGE(!PageLocked(oldpage), oldpage); | |
5694 | VM_BUG_ON_PAGE(!PageLocked(newpage), newpage); | |
5695 | VM_BUG_ON_PAGE(!lrucare && PageLRU(oldpage), oldpage); | |
5696 | VM_BUG_ON_PAGE(!lrucare && PageLRU(newpage), newpage); | |
5697 | VM_BUG_ON_PAGE(PageAnon(oldpage) != PageAnon(newpage), newpage); | |
6abb5a86 JW |
5698 | VM_BUG_ON_PAGE(PageTransHuge(oldpage) != PageTransHuge(newpage), |
5699 | newpage); | |
0a31bc97 JW |
5700 | |
5701 | if (mem_cgroup_disabled()) | |
5702 | return; | |
5703 | ||
5704 | /* Page cache replacement: new page already charged? */ | |
1306a85a | 5705 | if (newpage->mem_cgroup) |
0a31bc97 JW |
5706 | return; |
5707 | ||
7d5e3245 JW |
5708 | /* |
5709 | * Swapcache readahead pages can get migrated before being | |
5710 | * charged, and migration from compaction can happen to an | |
5711 | * uncharged page when the PFN walker finds a page that | |
5712 | * reclaim just put back on the LRU but has not released yet. | |
5713 | */ | |
1306a85a | 5714 | memcg = oldpage->mem_cgroup; |
29833315 | 5715 | if (!memcg) |
0a31bc97 JW |
5716 | return; |
5717 | ||
0a31bc97 JW |
5718 | if (lrucare) |
5719 | lock_page_lru(oldpage, &isolated); | |
5720 | ||
1306a85a | 5721 | oldpage->mem_cgroup = NULL; |
0a31bc97 JW |
5722 | |
5723 | if (lrucare) | |
5724 | unlock_page_lru(oldpage, isolated); | |
5725 | ||
29833315 | 5726 | commit_charge(newpage, memcg, lrucare); |
0a31bc97 JW |
5727 | } |
5728 | ||
2d11085e | 5729 | /* |
1081312f MH |
5730 | * subsys_initcall() for memory controller. |
5731 | * | |
5732 | * Some parts like hotcpu_notifier() have to be initialized from this context | |
5733 | * because of lock dependencies (cgroup_lock -> cpu hotplug) but basically | |
5734 | * everything that doesn't depend on a specific mem_cgroup structure should | |
5735 | * be initialized from here. | |
2d11085e MH |
5736 | */ |
5737 | static int __init mem_cgroup_init(void) | |
5738 | { | |
95a045f6 JW |
5739 | int cpu, node; |
5740 | ||
2d11085e | 5741 | hotcpu_notifier(memcg_cpu_hotplug_callback, 0); |
95a045f6 JW |
5742 | |
5743 | for_each_possible_cpu(cpu) | |
5744 | INIT_WORK(&per_cpu_ptr(&memcg_stock, cpu)->work, | |
5745 | drain_local_stock); | |
5746 | ||
5747 | for_each_node(node) { | |
5748 | struct mem_cgroup_tree_per_node *rtpn; | |
5749 | int zone; | |
5750 | ||
5751 | rtpn = kzalloc_node(sizeof(*rtpn), GFP_KERNEL, | |
5752 | node_online(node) ? node : NUMA_NO_NODE); | |
5753 | ||
5754 | for (zone = 0; zone < MAX_NR_ZONES; zone++) { | |
5755 | struct mem_cgroup_tree_per_zone *rtpz; | |
5756 | ||
5757 | rtpz = &rtpn->rb_tree_per_zone[zone]; | |
5758 | rtpz->rb_root = RB_ROOT; | |
5759 | spin_lock_init(&rtpz->lock); | |
5760 | } | |
5761 | soft_limit_tree.rb_tree_per_node[node] = rtpn; | |
5762 | } | |
5763 | ||
2d11085e MH |
5764 | return 0; |
5765 | } | |
5766 | subsys_initcall(mem_cgroup_init); | |
21afa38e JW |
5767 | |
5768 | #ifdef CONFIG_MEMCG_SWAP | |
5769 | /** | |
5770 | * mem_cgroup_swapout - transfer a memsw charge to swap | |
5771 | * @page: page whose memsw charge to transfer | |
5772 | * @entry: swap entry to move the charge to | |
5773 | * | |
5774 | * Transfer the memsw charge of @page to @entry. | |
5775 | */ | |
5776 | void mem_cgroup_swapout(struct page *page, swp_entry_t entry) | |
5777 | { | |
5778 | struct mem_cgroup *memcg; | |
5779 | unsigned short oldid; | |
5780 | ||
5781 | VM_BUG_ON_PAGE(PageLRU(page), page); | |
5782 | VM_BUG_ON_PAGE(page_count(page), page); | |
5783 | ||
5784 | if (!do_swap_account) | |
5785 | return; | |
5786 | ||
5787 | memcg = page->mem_cgroup; | |
5788 | ||
5789 | /* Readahead page, never charged */ | |
5790 | if (!memcg) | |
5791 | return; | |
5792 | ||
5793 | oldid = swap_cgroup_record(entry, mem_cgroup_id(memcg)); | |
5794 | VM_BUG_ON_PAGE(oldid, page); | |
5795 | mem_cgroup_swap_statistics(memcg, true); | |
5796 | ||
5797 | page->mem_cgroup = NULL; | |
5798 | ||
5799 | if (!mem_cgroup_is_root(memcg)) | |
5800 | page_counter_uncharge(&memcg->memory, 1); | |
5801 | ||
5802 | /* XXX: caller holds IRQ-safe mapping->tree_lock */ | |
5803 | VM_BUG_ON(!irqs_disabled()); | |
5804 | ||
5805 | mem_cgroup_charge_statistics(memcg, page, -1); | |
5806 | memcg_check_events(memcg, page); | |
5807 | } | |
5808 | ||
5809 | /** | |
5810 | * mem_cgroup_uncharge_swap - uncharge a swap entry | |
5811 | * @entry: swap entry to uncharge | |
5812 | * | |
5813 | * Drop the memsw charge associated with @entry. | |
5814 | */ | |
5815 | void mem_cgroup_uncharge_swap(swp_entry_t entry) | |
5816 | { | |
5817 | struct mem_cgroup *memcg; | |
5818 | unsigned short id; | |
5819 | ||
5820 | if (!do_swap_account) | |
5821 | return; | |
5822 | ||
5823 | id = swap_cgroup_record(entry, 0); | |
5824 | rcu_read_lock(); | |
5825 | memcg = mem_cgroup_lookup(id); | |
5826 | if (memcg) { | |
5827 | if (!mem_cgroup_is_root(memcg)) | |
5828 | page_counter_uncharge(&memcg->memsw, 1); | |
5829 | mem_cgroup_swap_statistics(memcg, false); | |
5830 | css_put(&memcg->css); | |
5831 | } | |
5832 | rcu_read_unlock(); | |
5833 | } | |
5834 | ||
5835 | /* for remember boot option*/ | |
5836 | #ifdef CONFIG_MEMCG_SWAP_ENABLED | |
5837 | static int really_do_swap_account __initdata = 1; | |
5838 | #else | |
5839 | static int really_do_swap_account __initdata; | |
5840 | #endif | |
5841 | ||
5842 | static int __init enable_swap_account(char *s) | |
5843 | { | |
5844 | if (!strcmp(s, "1")) | |
5845 | really_do_swap_account = 1; | |
5846 | else if (!strcmp(s, "0")) | |
5847 | really_do_swap_account = 0; | |
5848 | return 1; | |
5849 | } | |
5850 | __setup("swapaccount=", enable_swap_account); | |
5851 | ||
5852 | static struct cftype memsw_cgroup_files[] = { | |
5853 | { | |
5854 | .name = "memsw.usage_in_bytes", | |
5855 | .private = MEMFILE_PRIVATE(_MEMSWAP, RES_USAGE), | |
5856 | .read_u64 = mem_cgroup_read_u64, | |
5857 | }, | |
5858 | { | |
5859 | .name = "memsw.max_usage_in_bytes", | |
5860 | .private = MEMFILE_PRIVATE(_MEMSWAP, RES_MAX_USAGE), | |
5861 | .write = mem_cgroup_reset, | |
5862 | .read_u64 = mem_cgroup_read_u64, | |
5863 | }, | |
5864 | { | |
5865 | .name = "memsw.limit_in_bytes", | |
5866 | .private = MEMFILE_PRIVATE(_MEMSWAP, RES_LIMIT), | |
5867 | .write = mem_cgroup_write, | |
5868 | .read_u64 = mem_cgroup_read_u64, | |
5869 | }, | |
5870 | { | |
5871 | .name = "memsw.failcnt", | |
5872 | .private = MEMFILE_PRIVATE(_MEMSWAP, RES_FAILCNT), | |
5873 | .write = mem_cgroup_reset, | |
5874 | .read_u64 = mem_cgroup_read_u64, | |
5875 | }, | |
5876 | { }, /* terminate */ | |
5877 | }; | |
5878 | ||
5879 | static int __init mem_cgroup_swap_init(void) | |
5880 | { | |
5881 | if (!mem_cgroup_disabled() && really_do_swap_account) { | |
5882 | do_swap_account = 1; | |
5883 | WARN_ON(cgroup_add_legacy_cftypes(&memory_cgrp_subsys, | |
5884 | memsw_cgroup_files)); | |
5885 | } | |
5886 | return 0; | |
5887 | } | |
5888 | subsys_initcall(mem_cgroup_swap_init); | |
5889 | ||
5890 | #endif /* CONFIG_MEMCG_SWAP */ |