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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> |
52d4b9ac | 54 | #include <linux/page_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 | |
c255a458 | 75 | #ifdef CONFIG_MEMCG_SWAP |
338c8431 | 76 | /* Turned on only when memory cgroup is enabled && really_do_swap_account = 1 */ |
c077719b | 77 | int do_swap_account __read_mostly; |
a42c390c MH |
78 | |
79 | /* for remember boot option*/ | |
c255a458 | 80 | #ifdef CONFIG_MEMCG_SWAP_ENABLED |
a42c390c MH |
81 | static int really_do_swap_account __initdata = 1; |
82 | #else | |
ada4ba59 | 83 | static int really_do_swap_account __initdata; |
a42c390c MH |
84 | #endif |
85 | ||
c077719b | 86 | #else |
a0db00fc | 87 | #define do_swap_account 0 |
c077719b KH |
88 | #endif |
89 | ||
90 | ||
af7c4b0e JW |
91 | static const char * const mem_cgroup_stat_names[] = { |
92 | "cache", | |
93 | "rss", | |
b070e65c | 94 | "rss_huge", |
af7c4b0e | 95 | "mapped_file", |
3ea67d06 | 96 | "writeback", |
af7c4b0e JW |
97 | "swap", |
98 | }; | |
99 | ||
e9f8974f JW |
100 | enum mem_cgroup_events_index { |
101 | MEM_CGROUP_EVENTS_PGPGIN, /* # of pages paged in */ | |
102 | MEM_CGROUP_EVENTS_PGPGOUT, /* # of pages paged out */ | |
456f998e YH |
103 | MEM_CGROUP_EVENTS_PGFAULT, /* # of page-faults */ |
104 | MEM_CGROUP_EVENTS_PGMAJFAULT, /* # of major page-faults */ | |
e9f8974f JW |
105 | MEM_CGROUP_EVENTS_NSTATS, |
106 | }; | |
af7c4b0e JW |
107 | |
108 | static const char * const mem_cgroup_events_names[] = { | |
109 | "pgpgin", | |
110 | "pgpgout", | |
111 | "pgfault", | |
112 | "pgmajfault", | |
113 | }; | |
114 | ||
58cf188e SZ |
115 | static const char * const mem_cgroup_lru_names[] = { |
116 | "inactive_anon", | |
117 | "active_anon", | |
118 | "inactive_file", | |
119 | "active_file", | |
120 | "unevictable", | |
121 | }; | |
122 | ||
7a159cc9 JW |
123 | /* |
124 | * Per memcg event counter is incremented at every pagein/pageout. With THP, | |
125 | * it will be incremated by the number of pages. This counter is used for | |
126 | * for trigger some periodic events. This is straightforward and better | |
127 | * than using jiffies etc. to handle periodic memcg event. | |
128 | */ | |
129 | enum mem_cgroup_events_target { | |
130 | MEM_CGROUP_TARGET_THRESH, | |
bb4cc1a8 | 131 | MEM_CGROUP_TARGET_SOFTLIMIT, |
453a9bf3 | 132 | MEM_CGROUP_TARGET_NUMAINFO, |
7a159cc9 JW |
133 | MEM_CGROUP_NTARGETS, |
134 | }; | |
a0db00fc KS |
135 | #define THRESHOLDS_EVENTS_TARGET 128 |
136 | #define SOFTLIMIT_EVENTS_TARGET 1024 | |
137 | #define NUMAINFO_EVENTS_TARGET 1024 | |
e9f8974f | 138 | |
d52aa412 | 139 | struct mem_cgroup_stat_cpu { |
7a159cc9 | 140 | long count[MEM_CGROUP_STAT_NSTATS]; |
e9f8974f | 141 | unsigned long events[MEM_CGROUP_EVENTS_NSTATS]; |
13114716 | 142 | unsigned long nr_page_events; |
7a159cc9 | 143 | unsigned long targets[MEM_CGROUP_NTARGETS]; |
d52aa412 KH |
144 | }; |
145 | ||
5ac8fb31 JW |
146 | struct reclaim_iter { |
147 | struct mem_cgroup *position; | |
527a5ec9 JW |
148 | /* scan generation, increased every round-trip */ |
149 | unsigned int generation; | |
150 | }; | |
151 | ||
6d12e2d8 KH |
152 | /* |
153 | * per-zone information in memory controller. | |
154 | */ | |
6d12e2d8 | 155 | struct mem_cgroup_per_zone { |
6290df54 | 156 | struct lruvec lruvec; |
1eb49272 | 157 | unsigned long lru_size[NR_LRU_LISTS]; |
3e2f41f1 | 158 | |
5ac8fb31 | 159 | struct reclaim_iter iter[DEF_PRIORITY + 1]; |
527a5ec9 | 160 | |
bb4cc1a8 | 161 | struct rb_node tree_node; /* RB tree node */ |
3e32cb2e | 162 | unsigned long usage_in_excess;/* Set to the value by which */ |
bb4cc1a8 AM |
163 | /* the soft limit is exceeded*/ |
164 | bool on_tree; | |
d79154bb | 165 | struct mem_cgroup *memcg; /* Back pointer, we cannot */ |
4e416953 | 166 | /* use container_of */ |
6d12e2d8 | 167 | }; |
6d12e2d8 KH |
168 | |
169 | struct mem_cgroup_per_node { | |
170 | struct mem_cgroup_per_zone zoneinfo[MAX_NR_ZONES]; | |
171 | }; | |
172 | ||
bb4cc1a8 AM |
173 | /* |
174 | * Cgroups above their limits are maintained in a RB-Tree, independent of | |
175 | * their hierarchy representation | |
176 | */ | |
177 | ||
178 | struct mem_cgroup_tree_per_zone { | |
179 | struct rb_root rb_root; | |
180 | spinlock_t lock; | |
181 | }; | |
182 | ||
183 | struct mem_cgroup_tree_per_node { | |
184 | struct mem_cgroup_tree_per_zone rb_tree_per_zone[MAX_NR_ZONES]; | |
185 | }; | |
186 | ||
187 | struct mem_cgroup_tree { | |
188 | struct mem_cgroup_tree_per_node *rb_tree_per_node[MAX_NUMNODES]; | |
189 | }; | |
190 | ||
191 | static struct mem_cgroup_tree soft_limit_tree __read_mostly; | |
192 | ||
2e72b634 KS |
193 | struct mem_cgroup_threshold { |
194 | struct eventfd_ctx *eventfd; | |
3e32cb2e | 195 | unsigned long threshold; |
2e72b634 KS |
196 | }; |
197 | ||
9490ff27 | 198 | /* For threshold */ |
2e72b634 | 199 | struct mem_cgroup_threshold_ary { |
748dad36 | 200 | /* An array index points to threshold just below or equal to usage. */ |
5407a562 | 201 | int current_threshold; |
2e72b634 KS |
202 | /* Size of entries[] */ |
203 | unsigned int size; | |
204 | /* Array of thresholds */ | |
205 | struct mem_cgroup_threshold entries[0]; | |
206 | }; | |
2c488db2 KS |
207 | |
208 | struct mem_cgroup_thresholds { | |
209 | /* Primary thresholds array */ | |
210 | struct mem_cgroup_threshold_ary *primary; | |
211 | /* | |
212 | * Spare threshold array. | |
213 | * This is needed to make mem_cgroup_unregister_event() "never fail". | |
214 | * It must be able to store at least primary->size - 1 entries. | |
215 | */ | |
216 | struct mem_cgroup_threshold_ary *spare; | |
217 | }; | |
218 | ||
9490ff27 KH |
219 | /* for OOM */ |
220 | struct mem_cgroup_eventfd_list { | |
221 | struct list_head list; | |
222 | struct eventfd_ctx *eventfd; | |
223 | }; | |
2e72b634 | 224 | |
79bd9814 TH |
225 | /* |
226 | * cgroup_event represents events which userspace want to receive. | |
227 | */ | |
3bc942f3 | 228 | struct mem_cgroup_event { |
79bd9814 | 229 | /* |
59b6f873 | 230 | * memcg which the event belongs to. |
79bd9814 | 231 | */ |
59b6f873 | 232 | struct mem_cgroup *memcg; |
79bd9814 TH |
233 | /* |
234 | * eventfd to signal userspace about the event. | |
235 | */ | |
236 | struct eventfd_ctx *eventfd; | |
237 | /* | |
238 | * Each of these stored in a list by the cgroup. | |
239 | */ | |
240 | struct list_head list; | |
fba94807 TH |
241 | /* |
242 | * register_event() callback will be used to add new userspace | |
243 | * waiter for changes related to this event. Use eventfd_signal() | |
244 | * on eventfd to send notification to userspace. | |
245 | */ | |
59b6f873 | 246 | int (*register_event)(struct mem_cgroup *memcg, |
347c4a87 | 247 | struct eventfd_ctx *eventfd, const char *args); |
fba94807 TH |
248 | /* |
249 | * unregister_event() callback will be called when userspace closes | |
250 | * the eventfd or on cgroup removing. This callback must be set, | |
251 | * if you want provide notification functionality. | |
252 | */ | |
59b6f873 | 253 | void (*unregister_event)(struct mem_cgroup *memcg, |
fba94807 | 254 | struct eventfd_ctx *eventfd); |
79bd9814 TH |
255 | /* |
256 | * All fields below needed to unregister event when | |
257 | * userspace closes eventfd. | |
258 | */ | |
259 | poll_table pt; | |
260 | wait_queue_head_t *wqh; | |
261 | wait_queue_t wait; | |
262 | struct work_struct remove; | |
263 | }; | |
264 | ||
c0ff4b85 R |
265 | static void mem_cgroup_threshold(struct mem_cgroup *memcg); |
266 | static void mem_cgroup_oom_notify(struct mem_cgroup *memcg); | |
2e72b634 | 267 | |
8cdea7c0 BS |
268 | /* |
269 | * The memory controller data structure. The memory controller controls both | |
270 | * page cache and RSS per cgroup. We would eventually like to provide | |
271 | * statistics based on the statistics developed by Rik Van Riel for clock-pro, | |
272 | * to help the administrator determine what knobs to tune. | |
273 | * | |
274 | * TODO: Add a water mark for the memory controller. Reclaim will begin when | |
8a9f3ccd BS |
275 | * we hit the water mark. May be even add a low water mark, such that |
276 | * no reclaim occurs from a cgroup at it's low water mark, this is | |
277 | * a feature that will be implemented much later in the future. | |
8cdea7c0 BS |
278 | */ |
279 | struct mem_cgroup { | |
280 | struct cgroup_subsys_state css; | |
3e32cb2e JW |
281 | |
282 | /* Accounted resources */ | |
283 | struct page_counter memory; | |
284 | struct page_counter memsw; | |
285 | struct page_counter kmem; | |
286 | ||
287 | unsigned long soft_limit; | |
59927fb9 | 288 | |
70ddf637 AV |
289 | /* vmpressure notifications */ |
290 | struct vmpressure vmpressure; | |
291 | ||
2f7dd7a4 JW |
292 | /* css_online() has been completed */ |
293 | int initialized; | |
294 | ||
18f59ea7 BS |
295 | /* |
296 | * Should the accounting and control be hierarchical, per subtree? | |
297 | */ | |
298 | bool use_hierarchy; | |
510fc4e1 | 299 | unsigned long kmem_account_flags; /* See KMEM_ACCOUNTED_*, below */ |
79dfdacc MH |
300 | |
301 | bool oom_lock; | |
302 | atomic_t under_oom; | |
3812c8c8 | 303 | atomic_t oom_wakeups; |
79dfdacc | 304 | |
1f4c025b | 305 | int swappiness; |
3c11ecf4 KH |
306 | /* OOM-Killer disable */ |
307 | int oom_kill_disable; | |
a7885eb8 | 308 | |
2e72b634 KS |
309 | /* protect arrays of thresholds */ |
310 | struct mutex thresholds_lock; | |
311 | ||
312 | /* thresholds for memory usage. RCU-protected */ | |
2c488db2 | 313 | struct mem_cgroup_thresholds thresholds; |
907860ed | 314 | |
2e72b634 | 315 | /* thresholds for mem+swap usage. RCU-protected */ |
2c488db2 | 316 | struct mem_cgroup_thresholds memsw_thresholds; |
907860ed | 317 | |
9490ff27 KH |
318 | /* For oom notifier event fd */ |
319 | struct list_head oom_notify; | |
185efc0f | 320 | |
7dc74be0 DN |
321 | /* |
322 | * Should we move charges of a task when a task is moved into this | |
323 | * mem_cgroup ? And what type of charges should we move ? | |
324 | */ | |
f894ffa8 | 325 | unsigned long move_charge_at_immigrate; |
619d094b KH |
326 | /* |
327 | * set > 0 if pages under this cgroup are moving to other cgroup. | |
328 | */ | |
329 | atomic_t moving_account; | |
312734c0 KH |
330 | /* taken only while moving_account > 0 */ |
331 | spinlock_t move_lock; | |
d52aa412 | 332 | /* |
c62b1a3b | 333 | * percpu counter. |
d52aa412 | 334 | */ |
3a7951b4 | 335 | struct mem_cgroup_stat_cpu __percpu *stat; |
711d3d2c KH |
336 | /* |
337 | * used when a cpu is offlined or other synchronizations | |
338 | * See mem_cgroup_read_stat(). | |
339 | */ | |
340 | struct mem_cgroup_stat_cpu nocpu_base; | |
341 | spinlock_t pcp_counter_lock; | |
d1a4c0b3 | 342 | |
4bd2c1ee | 343 | #if defined(CONFIG_MEMCG_KMEM) && defined(CONFIG_INET) |
2e685cad | 344 | struct cg_proto tcp_mem; |
d1a4c0b3 | 345 | #endif |
2633d7a0 | 346 | #if defined(CONFIG_MEMCG_KMEM) |
bd673145 VD |
347 | /* analogous to slab_common's slab_caches list, but per-memcg; |
348 | * protected by memcg_slab_mutex */ | |
2633d7a0 | 349 | struct list_head memcg_slab_caches; |
2633d7a0 GC |
350 | /* Index in the kmem_cache->memcg_params->memcg_caches array */ |
351 | int kmemcg_id; | |
352 | #endif | |
45cf7ebd GC |
353 | |
354 | int last_scanned_node; | |
355 | #if MAX_NUMNODES > 1 | |
356 | nodemask_t scan_nodes; | |
357 | atomic_t numainfo_events; | |
358 | atomic_t numainfo_updating; | |
359 | #endif | |
70ddf637 | 360 | |
fba94807 TH |
361 | /* List of events which userspace want to receive */ |
362 | struct list_head event_list; | |
363 | spinlock_t event_list_lock; | |
364 | ||
54f72fe0 JW |
365 | struct mem_cgroup_per_node *nodeinfo[0]; |
366 | /* WARNING: nodeinfo must be the last member here */ | |
8cdea7c0 BS |
367 | }; |
368 | ||
510fc4e1 GC |
369 | /* internal only representation about the status of kmem accounting. */ |
370 | enum { | |
6de64beb | 371 | KMEM_ACCOUNTED_ACTIVE, /* accounted by this cgroup itself */ |
510fc4e1 GC |
372 | }; |
373 | ||
510fc4e1 GC |
374 | #ifdef CONFIG_MEMCG_KMEM |
375 | static inline void memcg_kmem_set_active(struct mem_cgroup *memcg) | |
376 | { | |
377 | set_bit(KMEM_ACCOUNTED_ACTIVE, &memcg->kmem_account_flags); | |
378 | } | |
7de37682 GC |
379 | |
380 | static bool memcg_kmem_is_active(struct mem_cgroup *memcg) | |
381 | { | |
382 | return test_bit(KMEM_ACCOUNTED_ACTIVE, &memcg->kmem_account_flags); | |
383 | } | |
384 | ||
510fc4e1 GC |
385 | #endif |
386 | ||
7dc74be0 DN |
387 | /* Stuffs for move charges at task migration. */ |
388 | /* | |
ee5e8472 GC |
389 | * Types of charges to be moved. "move_charge_at_immitgrate" and |
390 | * "immigrate_flags" are treated as a left-shifted bitmap of these types. | |
7dc74be0 DN |
391 | */ |
392 | enum move_type { | |
4ffef5fe | 393 | MOVE_CHARGE_TYPE_ANON, /* private anonymous page and swap of it */ |
87946a72 | 394 | MOVE_CHARGE_TYPE_FILE, /* file page(including tmpfs) and swap of it */ |
7dc74be0 DN |
395 | NR_MOVE_TYPE, |
396 | }; | |
397 | ||
4ffef5fe DN |
398 | /* "mc" and its members are protected by cgroup_mutex */ |
399 | static struct move_charge_struct { | |
b1dd693e | 400 | spinlock_t lock; /* for from, to */ |
4ffef5fe DN |
401 | struct mem_cgroup *from; |
402 | struct mem_cgroup *to; | |
ee5e8472 | 403 | unsigned long immigrate_flags; |
4ffef5fe | 404 | unsigned long precharge; |
854ffa8d | 405 | unsigned long moved_charge; |
483c30b5 | 406 | unsigned long moved_swap; |
8033b97c DN |
407 | struct task_struct *moving_task; /* a task moving charges */ |
408 | wait_queue_head_t waitq; /* a waitq for other context */ | |
409 | } mc = { | |
2bd9bb20 | 410 | .lock = __SPIN_LOCK_UNLOCKED(mc.lock), |
8033b97c DN |
411 | .waitq = __WAIT_QUEUE_HEAD_INITIALIZER(mc.waitq), |
412 | }; | |
4ffef5fe | 413 | |
90254a65 DN |
414 | static bool move_anon(void) |
415 | { | |
ee5e8472 | 416 | return test_bit(MOVE_CHARGE_TYPE_ANON, &mc.immigrate_flags); |
90254a65 DN |
417 | } |
418 | ||
87946a72 DN |
419 | static bool move_file(void) |
420 | { | |
ee5e8472 | 421 | return test_bit(MOVE_CHARGE_TYPE_FILE, &mc.immigrate_flags); |
87946a72 DN |
422 | } |
423 | ||
4e416953 BS |
424 | /* |
425 | * Maximum loops in mem_cgroup_hierarchical_reclaim(), used for soft | |
426 | * limit reclaim to prevent infinite loops, if they ever occur. | |
427 | */ | |
a0db00fc | 428 | #define MEM_CGROUP_MAX_RECLAIM_LOOPS 100 |
bb4cc1a8 | 429 | #define MEM_CGROUP_MAX_SOFT_LIMIT_RECLAIM_LOOPS 2 |
4e416953 | 430 | |
217bc319 KH |
431 | enum charge_type { |
432 | MEM_CGROUP_CHARGE_TYPE_CACHE = 0, | |
41326c17 | 433 | MEM_CGROUP_CHARGE_TYPE_ANON, |
d13d1443 | 434 | MEM_CGROUP_CHARGE_TYPE_SWAPOUT, /* for accounting swapcache */ |
8a9478ca | 435 | MEM_CGROUP_CHARGE_TYPE_DROP, /* a page was unused swap cache */ |
c05555b5 KH |
436 | NR_CHARGE_TYPE, |
437 | }; | |
438 | ||
8c7c6e34 | 439 | /* for encoding cft->private value on file */ |
86ae53e1 GC |
440 | enum res_type { |
441 | _MEM, | |
442 | _MEMSWAP, | |
443 | _OOM_TYPE, | |
510fc4e1 | 444 | _KMEM, |
86ae53e1 GC |
445 | }; |
446 | ||
a0db00fc KS |
447 | #define MEMFILE_PRIVATE(x, val) ((x) << 16 | (val)) |
448 | #define MEMFILE_TYPE(val) ((val) >> 16 & 0xffff) | |
8c7c6e34 | 449 | #define MEMFILE_ATTR(val) ((val) & 0xffff) |
9490ff27 KH |
450 | /* Used for OOM nofiier */ |
451 | #define OOM_CONTROL (0) | |
8c7c6e34 | 452 | |
0999821b GC |
453 | /* |
454 | * The memcg_create_mutex will be held whenever a new cgroup is created. | |
455 | * As a consequence, any change that needs to protect against new child cgroups | |
456 | * appearing has to hold it as well. | |
457 | */ | |
458 | static DEFINE_MUTEX(memcg_create_mutex); | |
459 | ||
b2145145 WL |
460 | struct mem_cgroup *mem_cgroup_from_css(struct cgroup_subsys_state *s) |
461 | { | |
a7c6d554 | 462 | return s ? container_of(s, struct mem_cgroup, css) : NULL; |
b2145145 WL |
463 | } |
464 | ||
70ddf637 AV |
465 | /* Some nice accessors for the vmpressure. */ |
466 | struct vmpressure *memcg_to_vmpressure(struct mem_cgroup *memcg) | |
467 | { | |
468 | if (!memcg) | |
469 | memcg = root_mem_cgroup; | |
470 | return &memcg->vmpressure; | |
471 | } | |
472 | ||
473 | struct cgroup_subsys_state *vmpressure_to_css(struct vmpressure *vmpr) | |
474 | { | |
475 | return &container_of(vmpr, struct mem_cgroup, vmpressure)->css; | |
476 | } | |
477 | ||
7ffc0edc MH |
478 | static inline bool mem_cgroup_is_root(struct mem_cgroup *memcg) |
479 | { | |
480 | return (memcg == root_mem_cgroup); | |
481 | } | |
482 | ||
4219b2da LZ |
483 | /* |
484 | * We restrict the id in the range of [1, 65535], so it can fit into | |
485 | * an unsigned short. | |
486 | */ | |
487 | #define MEM_CGROUP_ID_MAX USHRT_MAX | |
488 | ||
34c00c31 LZ |
489 | static inline unsigned short mem_cgroup_id(struct mem_cgroup *memcg) |
490 | { | |
15a4c835 | 491 | return memcg->css.id; |
34c00c31 LZ |
492 | } |
493 | ||
494 | static inline struct mem_cgroup *mem_cgroup_from_id(unsigned short id) | |
495 | { | |
496 | struct cgroup_subsys_state *css; | |
497 | ||
7d699ddb | 498 | css = css_from_id(id, &memory_cgrp_subsys); |
34c00c31 LZ |
499 | return mem_cgroup_from_css(css); |
500 | } | |
501 | ||
e1aab161 | 502 | /* Writing them here to avoid exposing memcg's inner layout */ |
4bd2c1ee | 503 | #if defined(CONFIG_INET) && defined(CONFIG_MEMCG_KMEM) |
e1aab161 | 504 | |
e1aab161 GC |
505 | void sock_update_memcg(struct sock *sk) |
506 | { | |
376be5ff | 507 | if (mem_cgroup_sockets_enabled) { |
e1aab161 | 508 | struct mem_cgroup *memcg; |
3f134619 | 509 | struct cg_proto *cg_proto; |
e1aab161 GC |
510 | |
511 | BUG_ON(!sk->sk_prot->proto_cgroup); | |
512 | ||
f3f511e1 GC |
513 | /* Socket cloning can throw us here with sk_cgrp already |
514 | * filled. It won't however, necessarily happen from | |
515 | * process context. So the test for root memcg given | |
516 | * the current task's memcg won't help us in this case. | |
517 | * | |
518 | * Respecting the original socket's memcg is a better | |
519 | * decision in this case. | |
520 | */ | |
521 | if (sk->sk_cgrp) { | |
522 | BUG_ON(mem_cgroup_is_root(sk->sk_cgrp->memcg)); | |
5347e5ae | 523 | css_get(&sk->sk_cgrp->memcg->css); |
f3f511e1 GC |
524 | return; |
525 | } | |
526 | ||
e1aab161 GC |
527 | rcu_read_lock(); |
528 | memcg = mem_cgroup_from_task(current); | |
3f134619 | 529 | cg_proto = sk->sk_prot->proto_cgroup(memcg); |
5347e5ae | 530 | if (!mem_cgroup_is_root(memcg) && |
ec903c0c TH |
531 | memcg_proto_active(cg_proto) && |
532 | css_tryget_online(&memcg->css)) { | |
3f134619 | 533 | sk->sk_cgrp = cg_proto; |
e1aab161 GC |
534 | } |
535 | rcu_read_unlock(); | |
536 | } | |
537 | } | |
538 | EXPORT_SYMBOL(sock_update_memcg); | |
539 | ||
540 | void sock_release_memcg(struct sock *sk) | |
541 | { | |
376be5ff | 542 | if (mem_cgroup_sockets_enabled && sk->sk_cgrp) { |
e1aab161 GC |
543 | struct mem_cgroup *memcg; |
544 | WARN_ON(!sk->sk_cgrp->memcg); | |
545 | memcg = sk->sk_cgrp->memcg; | |
5347e5ae | 546 | css_put(&sk->sk_cgrp->memcg->css); |
e1aab161 GC |
547 | } |
548 | } | |
d1a4c0b3 GC |
549 | |
550 | struct cg_proto *tcp_proto_cgroup(struct mem_cgroup *memcg) | |
551 | { | |
552 | if (!memcg || mem_cgroup_is_root(memcg)) | |
553 | return NULL; | |
554 | ||
2e685cad | 555 | return &memcg->tcp_mem; |
d1a4c0b3 GC |
556 | } |
557 | EXPORT_SYMBOL(tcp_proto_cgroup); | |
e1aab161 | 558 | |
3f134619 GC |
559 | static void disarm_sock_keys(struct mem_cgroup *memcg) |
560 | { | |
2e685cad | 561 | if (!memcg_proto_activated(&memcg->tcp_mem)) |
3f134619 GC |
562 | return; |
563 | static_key_slow_dec(&memcg_socket_limit_enabled); | |
564 | } | |
565 | #else | |
566 | static void disarm_sock_keys(struct mem_cgroup *memcg) | |
567 | { | |
568 | } | |
569 | #endif | |
570 | ||
a8964b9b | 571 | #ifdef CONFIG_MEMCG_KMEM |
55007d84 GC |
572 | /* |
573 | * This will be the memcg's index in each cache's ->memcg_params->memcg_caches. | |
b8627835 LZ |
574 | * The main reason for not using cgroup id for this: |
575 | * this works better in sparse environments, where we have a lot of memcgs, | |
576 | * but only a few kmem-limited. Or also, if we have, for instance, 200 | |
577 | * memcgs, and none but the 200th is kmem-limited, we'd have to have a | |
578 | * 200 entry array for that. | |
55007d84 GC |
579 | * |
580 | * The current size of the caches array is stored in | |
581 | * memcg_limited_groups_array_size. It will double each time we have to | |
582 | * increase it. | |
583 | */ | |
584 | static DEFINE_IDA(kmem_limited_groups); | |
749c5415 GC |
585 | int memcg_limited_groups_array_size; |
586 | ||
55007d84 GC |
587 | /* |
588 | * MIN_SIZE is different than 1, because we would like to avoid going through | |
589 | * the alloc/free process all the time. In a small machine, 4 kmem-limited | |
590 | * cgroups is a reasonable guess. In the future, it could be a parameter or | |
591 | * tunable, but that is strictly not necessary. | |
592 | * | |
b8627835 | 593 | * MAX_SIZE should be as large as the number of cgrp_ids. Ideally, we could get |
55007d84 GC |
594 | * this constant directly from cgroup, but it is understandable that this is |
595 | * better kept as an internal representation in cgroup.c. In any case, the | |
b8627835 | 596 | * cgrp_id space is not getting any smaller, and we don't have to necessarily |
55007d84 GC |
597 | * increase ours as well if it increases. |
598 | */ | |
599 | #define MEMCG_CACHES_MIN_SIZE 4 | |
b8627835 | 600 | #define MEMCG_CACHES_MAX_SIZE MEM_CGROUP_ID_MAX |
55007d84 | 601 | |
d7f25f8a GC |
602 | /* |
603 | * A lot of the calls to the cache allocation functions are expected to be | |
604 | * inlined by the compiler. Since the calls to memcg_kmem_get_cache are | |
605 | * conditional to this static branch, we'll have to allow modules that does | |
606 | * kmem_cache_alloc and the such to see this symbol as well | |
607 | */ | |
a8964b9b | 608 | struct static_key memcg_kmem_enabled_key; |
d7f25f8a | 609 | EXPORT_SYMBOL(memcg_kmem_enabled_key); |
a8964b9b | 610 | |
f3bb3043 VD |
611 | static void memcg_free_cache_id(int id); |
612 | ||
a8964b9b GC |
613 | static void disarm_kmem_keys(struct mem_cgroup *memcg) |
614 | { | |
55007d84 | 615 | if (memcg_kmem_is_active(memcg)) { |
a8964b9b | 616 | static_key_slow_dec(&memcg_kmem_enabled_key); |
f3bb3043 | 617 | memcg_free_cache_id(memcg->kmemcg_id); |
55007d84 | 618 | } |
bea207c8 GC |
619 | /* |
620 | * This check can't live in kmem destruction function, | |
621 | * since the charges will outlive the cgroup | |
622 | */ | |
3e32cb2e | 623 | WARN_ON(page_counter_read(&memcg->kmem)); |
a8964b9b GC |
624 | } |
625 | #else | |
626 | static void disarm_kmem_keys(struct mem_cgroup *memcg) | |
627 | { | |
628 | } | |
629 | #endif /* CONFIG_MEMCG_KMEM */ | |
630 | ||
631 | static void disarm_static_keys(struct mem_cgroup *memcg) | |
632 | { | |
633 | disarm_sock_keys(memcg); | |
634 | disarm_kmem_keys(memcg); | |
635 | } | |
636 | ||
c0ff4b85 | 637 | static void drain_all_stock_async(struct mem_cgroup *memcg); |
8c7c6e34 | 638 | |
f64c3f54 | 639 | static struct mem_cgroup_per_zone * |
e231875b | 640 | mem_cgroup_zone_zoneinfo(struct mem_cgroup *memcg, struct zone *zone) |
f64c3f54 | 641 | { |
e231875b JZ |
642 | int nid = zone_to_nid(zone); |
643 | int zid = zone_idx(zone); | |
644 | ||
54f72fe0 | 645 | return &memcg->nodeinfo[nid]->zoneinfo[zid]; |
f64c3f54 BS |
646 | } |
647 | ||
c0ff4b85 | 648 | struct cgroup_subsys_state *mem_cgroup_css(struct mem_cgroup *memcg) |
d324236b | 649 | { |
c0ff4b85 | 650 | return &memcg->css; |
d324236b WF |
651 | } |
652 | ||
f64c3f54 | 653 | static struct mem_cgroup_per_zone * |
e231875b | 654 | mem_cgroup_page_zoneinfo(struct mem_cgroup *memcg, struct page *page) |
f64c3f54 | 655 | { |
97a6c37b JW |
656 | int nid = page_to_nid(page); |
657 | int zid = page_zonenum(page); | |
f64c3f54 | 658 | |
e231875b | 659 | return &memcg->nodeinfo[nid]->zoneinfo[zid]; |
f64c3f54 BS |
660 | } |
661 | ||
bb4cc1a8 AM |
662 | static struct mem_cgroup_tree_per_zone * |
663 | soft_limit_tree_node_zone(int nid, int zid) | |
664 | { | |
665 | return &soft_limit_tree.rb_tree_per_node[nid]->rb_tree_per_zone[zid]; | |
666 | } | |
667 | ||
668 | static struct mem_cgroup_tree_per_zone * | |
669 | soft_limit_tree_from_page(struct page *page) | |
670 | { | |
671 | int nid = page_to_nid(page); | |
672 | int zid = page_zonenum(page); | |
673 | ||
674 | return &soft_limit_tree.rb_tree_per_node[nid]->rb_tree_per_zone[zid]; | |
675 | } | |
676 | ||
cf2c8127 JW |
677 | static void __mem_cgroup_insert_exceeded(struct mem_cgroup_per_zone *mz, |
678 | struct mem_cgroup_tree_per_zone *mctz, | |
3e32cb2e | 679 | unsigned long new_usage_in_excess) |
bb4cc1a8 AM |
680 | { |
681 | struct rb_node **p = &mctz->rb_root.rb_node; | |
682 | struct rb_node *parent = NULL; | |
683 | struct mem_cgroup_per_zone *mz_node; | |
684 | ||
685 | if (mz->on_tree) | |
686 | return; | |
687 | ||
688 | mz->usage_in_excess = new_usage_in_excess; | |
689 | if (!mz->usage_in_excess) | |
690 | return; | |
691 | while (*p) { | |
692 | parent = *p; | |
693 | mz_node = rb_entry(parent, struct mem_cgroup_per_zone, | |
694 | tree_node); | |
695 | if (mz->usage_in_excess < mz_node->usage_in_excess) | |
696 | p = &(*p)->rb_left; | |
697 | /* | |
698 | * We can't avoid mem cgroups that are over their soft | |
699 | * limit by the same amount | |
700 | */ | |
701 | else if (mz->usage_in_excess >= mz_node->usage_in_excess) | |
702 | p = &(*p)->rb_right; | |
703 | } | |
704 | rb_link_node(&mz->tree_node, parent, p); | |
705 | rb_insert_color(&mz->tree_node, &mctz->rb_root); | |
706 | mz->on_tree = true; | |
707 | } | |
708 | ||
cf2c8127 JW |
709 | static void __mem_cgroup_remove_exceeded(struct mem_cgroup_per_zone *mz, |
710 | struct mem_cgroup_tree_per_zone *mctz) | |
bb4cc1a8 AM |
711 | { |
712 | if (!mz->on_tree) | |
713 | return; | |
714 | rb_erase(&mz->tree_node, &mctz->rb_root); | |
715 | mz->on_tree = false; | |
716 | } | |
717 | ||
cf2c8127 JW |
718 | static void mem_cgroup_remove_exceeded(struct mem_cgroup_per_zone *mz, |
719 | struct mem_cgroup_tree_per_zone *mctz) | |
bb4cc1a8 | 720 | { |
0a31bc97 JW |
721 | unsigned long flags; |
722 | ||
723 | spin_lock_irqsave(&mctz->lock, flags); | |
cf2c8127 | 724 | __mem_cgroup_remove_exceeded(mz, mctz); |
0a31bc97 | 725 | spin_unlock_irqrestore(&mctz->lock, flags); |
bb4cc1a8 AM |
726 | } |
727 | ||
3e32cb2e JW |
728 | static unsigned long soft_limit_excess(struct mem_cgroup *memcg) |
729 | { | |
730 | unsigned long nr_pages = page_counter_read(&memcg->memory); | |
731 | unsigned long soft_limit = ACCESS_ONCE(memcg->soft_limit); | |
732 | unsigned long excess = 0; | |
733 | ||
734 | if (nr_pages > soft_limit) | |
735 | excess = nr_pages - soft_limit; | |
736 | ||
737 | return excess; | |
738 | } | |
bb4cc1a8 AM |
739 | |
740 | static void mem_cgroup_update_tree(struct mem_cgroup *memcg, struct page *page) | |
741 | { | |
3e32cb2e | 742 | unsigned long excess; |
bb4cc1a8 AM |
743 | struct mem_cgroup_per_zone *mz; |
744 | struct mem_cgroup_tree_per_zone *mctz; | |
bb4cc1a8 | 745 | |
e231875b | 746 | mctz = soft_limit_tree_from_page(page); |
bb4cc1a8 AM |
747 | /* |
748 | * Necessary to update all ancestors when hierarchy is used. | |
749 | * because their event counter is not touched. | |
750 | */ | |
751 | for (; memcg; memcg = parent_mem_cgroup(memcg)) { | |
e231875b | 752 | mz = mem_cgroup_page_zoneinfo(memcg, page); |
3e32cb2e | 753 | excess = soft_limit_excess(memcg); |
bb4cc1a8 AM |
754 | /* |
755 | * We have to update the tree if mz is on RB-tree or | |
756 | * mem is over its softlimit. | |
757 | */ | |
758 | if (excess || mz->on_tree) { | |
0a31bc97 JW |
759 | unsigned long flags; |
760 | ||
761 | spin_lock_irqsave(&mctz->lock, flags); | |
bb4cc1a8 AM |
762 | /* if on-tree, remove it */ |
763 | if (mz->on_tree) | |
cf2c8127 | 764 | __mem_cgroup_remove_exceeded(mz, mctz); |
bb4cc1a8 AM |
765 | /* |
766 | * Insert again. mz->usage_in_excess will be updated. | |
767 | * If excess is 0, no tree ops. | |
768 | */ | |
cf2c8127 | 769 | __mem_cgroup_insert_exceeded(mz, mctz, excess); |
0a31bc97 | 770 | spin_unlock_irqrestore(&mctz->lock, flags); |
bb4cc1a8 AM |
771 | } |
772 | } | |
773 | } | |
774 | ||
775 | static void mem_cgroup_remove_from_trees(struct mem_cgroup *memcg) | |
776 | { | |
bb4cc1a8 | 777 | struct mem_cgroup_tree_per_zone *mctz; |
e231875b JZ |
778 | struct mem_cgroup_per_zone *mz; |
779 | int nid, zid; | |
bb4cc1a8 | 780 | |
e231875b JZ |
781 | for_each_node(nid) { |
782 | for (zid = 0; zid < MAX_NR_ZONES; zid++) { | |
783 | mz = &memcg->nodeinfo[nid]->zoneinfo[zid]; | |
784 | mctz = soft_limit_tree_node_zone(nid, zid); | |
cf2c8127 | 785 | mem_cgroup_remove_exceeded(mz, mctz); |
bb4cc1a8 AM |
786 | } |
787 | } | |
788 | } | |
789 | ||
790 | static struct mem_cgroup_per_zone * | |
791 | __mem_cgroup_largest_soft_limit_node(struct mem_cgroup_tree_per_zone *mctz) | |
792 | { | |
793 | struct rb_node *rightmost = NULL; | |
794 | struct mem_cgroup_per_zone *mz; | |
795 | ||
796 | retry: | |
797 | mz = NULL; | |
798 | rightmost = rb_last(&mctz->rb_root); | |
799 | if (!rightmost) | |
800 | goto done; /* Nothing to reclaim from */ | |
801 | ||
802 | mz = rb_entry(rightmost, struct mem_cgroup_per_zone, tree_node); | |
803 | /* | |
804 | * Remove the node now but someone else can add it back, | |
805 | * we will to add it back at the end of reclaim to its correct | |
806 | * position in the tree. | |
807 | */ | |
cf2c8127 | 808 | __mem_cgroup_remove_exceeded(mz, mctz); |
3e32cb2e | 809 | if (!soft_limit_excess(mz->memcg) || |
ec903c0c | 810 | !css_tryget_online(&mz->memcg->css)) |
bb4cc1a8 AM |
811 | goto retry; |
812 | done: | |
813 | return mz; | |
814 | } | |
815 | ||
816 | static struct mem_cgroup_per_zone * | |
817 | mem_cgroup_largest_soft_limit_node(struct mem_cgroup_tree_per_zone *mctz) | |
818 | { | |
819 | struct mem_cgroup_per_zone *mz; | |
820 | ||
0a31bc97 | 821 | spin_lock_irq(&mctz->lock); |
bb4cc1a8 | 822 | mz = __mem_cgroup_largest_soft_limit_node(mctz); |
0a31bc97 | 823 | spin_unlock_irq(&mctz->lock); |
bb4cc1a8 AM |
824 | return mz; |
825 | } | |
826 | ||
711d3d2c KH |
827 | /* |
828 | * Implementation Note: reading percpu statistics for memcg. | |
829 | * | |
830 | * Both of vmstat[] and percpu_counter has threshold and do periodic | |
831 | * synchronization to implement "quick" read. There are trade-off between | |
832 | * reading cost and precision of value. Then, we may have a chance to implement | |
833 | * a periodic synchronizion of counter in memcg's counter. | |
834 | * | |
835 | * But this _read() function is used for user interface now. The user accounts | |
836 | * memory usage by memory cgroup and he _always_ requires exact value because | |
837 | * he accounts memory. Even if we provide quick-and-fuzzy read, we always | |
838 | * have to visit all online cpus and make sum. So, for now, unnecessary | |
839 | * synchronization is not implemented. (just implemented for cpu hotplug) | |
840 | * | |
841 | * If there are kernel internal actions which can make use of some not-exact | |
842 | * value, and reading all cpu value can be performance bottleneck in some | |
843 | * common workload, threashold and synchonization as vmstat[] should be | |
844 | * implemented. | |
845 | */ | |
c0ff4b85 | 846 | static long mem_cgroup_read_stat(struct mem_cgroup *memcg, |
7a159cc9 | 847 | enum mem_cgroup_stat_index idx) |
c62b1a3b | 848 | { |
7a159cc9 | 849 | long val = 0; |
c62b1a3b | 850 | int cpu; |
c62b1a3b | 851 | |
711d3d2c KH |
852 | get_online_cpus(); |
853 | for_each_online_cpu(cpu) | |
c0ff4b85 | 854 | val += per_cpu(memcg->stat->count[idx], cpu); |
711d3d2c | 855 | #ifdef CONFIG_HOTPLUG_CPU |
c0ff4b85 R |
856 | spin_lock(&memcg->pcp_counter_lock); |
857 | val += memcg->nocpu_base.count[idx]; | |
858 | spin_unlock(&memcg->pcp_counter_lock); | |
711d3d2c KH |
859 | #endif |
860 | put_online_cpus(); | |
c62b1a3b KH |
861 | return val; |
862 | } | |
863 | ||
c0ff4b85 | 864 | static unsigned long mem_cgroup_read_events(struct mem_cgroup *memcg, |
e9f8974f JW |
865 | enum mem_cgroup_events_index idx) |
866 | { | |
867 | unsigned long val = 0; | |
868 | int cpu; | |
869 | ||
9c567512 | 870 | get_online_cpus(); |
e9f8974f | 871 | for_each_online_cpu(cpu) |
c0ff4b85 | 872 | val += per_cpu(memcg->stat->events[idx], cpu); |
e9f8974f | 873 | #ifdef CONFIG_HOTPLUG_CPU |
c0ff4b85 R |
874 | spin_lock(&memcg->pcp_counter_lock); |
875 | val += memcg->nocpu_base.events[idx]; | |
876 | spin_unlock(&memcg->pcp_counter_lock); | |
e9f8974f | 877 | #endif |
9c567512 | 878 | put_online_cpus(); |
e9f8974f JW |
879 | return val; |
880 | } | |
881 | ||
c0ff4b85 | 882 | static void mem_cgroup_charge_statistics(struct mem_cgroup *memcg, |
b070e65c | 883 | struct page *page, |
0a31bc97 | 884 | int nr_pages) |
d52aa412 | 885 | { |
b2402857 KH |
886 | /* |
887 | * Here, RSS means 'mapped anon' and anon's SwapCache. Shmem/tmpfs is | |
888 | * counted as CACHE even if it's on ANON LRU. | |
889 | */ | |
0a31bc97 | 890 | if (PageAnon(page)) |
b2402857 | 891 | __this_cpu_add(memcg->stat->count[MEM_CGROUP_STAT_RSS], |
c0ff4b85 | 892 | nr_pages); |
d52aa412 | 893 | else |
b2402857 | 894 | __this_cpu_add(memcg->stat->count[MEM_CGROUP_STAT_CACHE], |
c0ff4b85 | 895 | nr_pages); |
55e462b0 | 896 | |
b070e65c DR |
897 | if (PageTransHuge(page)) |
898 | __this_cpu_add(memcg->stat->count[MEM_CGROUP_STAT_RSS_HUGE], | |
899 | nr_pages); | |
900 | ||
e401f176 KH |
901 | /* pagein of a big page is an event. So, ignore page size */ |
902 | if (nr_pages > 0) | |
c0ff4b85 | 903 | __this_cpu_inc(memcg->stat->events[MEM_CGROUP_EVENTS_PGPGIN]); |
3751d604 | 904 | else { |
c0ff4b85 | 905 | __this_cpu_inc(memcg->stat->events[MEM_CGROUP_EVENTS_PGPGOUT]); |
3751d604 KH |
906 | nr_pages = -nr_pages; /* for event */ |
907 | } | |
e401f176 | 908 | |
13114716 | 909 | __this_cpu_add(memcg->stat->nr_page_events, nr_pages); |
6d12e2d8 KH |
910 | } |
911 | ||
e231875b | 912 | unsigned long mem_cgroup_get_lru_size(struct lruvec *lruvec, enum lru_list lru) |
074291fe KK |
913 | { |
914 | struct mem_cgroup_per_zone *mz; | |
915 | ||
916 | mz = container_of(lruvec, struct mem_cgroup_per_zone, lruvec); | |
917 | return mz->lru_size[lru]; | |
918 | } | |
919 | ||
e231875b JZ |
920 | static unsigned long mem_cgroup_node_nr_lru_pages(struct mem_cgroup *memcg, |
921 | int nid, | |
922 | unsigned int lru_mask) | |
bb2a0de9 | 923 | { |
e231875b | 924 | unsigned long nr = 0; |
889976db YH |
925 | int zid; |
926 | ||
e231875b | 927 | VM_BUG_ON((unsigned)nid >= nr_node_ids); |
bb2a0de9 | 928 | |
e231875b JZ |
929 | for (zid = 0; zid < MAX_NR_ZONES; zid++) { |
930 | struct mem_cgroup_per_zone *mz; | |
931 | enum lru_list lru; | |
932 | ||
933 | for_each_lru(lru) { | |
934 | if (!(BIT(lru) & lru_mask)) | |
935 | continue; | |
936 | mz = &memcg->nodeinfo[nid]->zoneinfo[zid]; | |
937 | nr += mz->lru_size[lru]; | |
938 | } | |
939 | } | |
940 | return nr; | |
889976db | 941 | } |
bb2a0de9 | 942 | |
c0ff4b85 | 943 | static unsigned long mem_cgroup_nr_lru_pages(struct mem_cgroup *memcg, |
bb2a0de9 | 944 | unsigned int lru_mask) |
6d12e2d8 | 945 | { |
e231875b | 946 | unsigned long nr = 0; |
889976db | 947 | int nid; |
6d12e2d8 | 948 | |
31aaea4a | 949 | for_each_node_state(nid, N_MEMORY) |
e231875b JZ |
950 | nr += mem_cgroup_node_nr_lru_pages(memcg, nid, lru_mask); |
951 | return nr; | |
d52aa412 KH |
952 | } |
953 | ||
f53d7ce3 JW |
954 | static bool mem_cgroup_event_ratelimit(struct mem_cgroup *memcg, |
955 | enum mem_cgroup_events_target target) | |
7a159cc9 JW |
956 | { |
957 | unsigned long val, next; | |
958 | ||
13114716 | 959 | val = __this_cpu_read(memcg->stat->nr_page_events); |
4799401f | 960 | next = __this_cpu_read(memcg->stat->targets[target]); |
7a159cc9 | 961 | /* from time_after() in jiffies.h */ |
f53d7ce3 JW |
962 | if ((long)next - (long)val < 0) { |
963 | switch (target) { | |
964 | case MEM_CGROUP_TARGET_THRESH: | |
965 | next = val + THRESHOLDS_EVENTS_TARGET; | |
966 | break; | |
bb4cc1a8 AM |
967 | case MEM_CGROUP_TARGET_SOFTLIMIT: |
968 | next = val + SOFTLIMIT_EVENTS_TARGET; | |
969 | break; | |
f53d7ce3 JW |
970 | case MEM_CGROUP_TARGET_NUMAINFO: |
971 | next = val + NUMAINFO_EVENTS_TARGET; | |
972 | break; | |
973 | default: | |
974 | break; | |
975 | } | |
976 | __this_cpu_write(memcg->stat->targets[target], next); | |
977 | return true; | |
7a159cc9 | 978 | } |
f53d7ce3 | 979 | return false; |
d2265e6f KH |
980 | } |
981 | ||
982 | /* | |
983 | * Check events in order. | |
984 | * | |
985 | */ | |
c0ff4b85 | 986 | static void memcg_check_events(struct mem_cgroup *memcg, struct page *page) |
d2265e6f KH |
987 | { |
988 | /* threshold event is triggered in finer grain than soft limit */ | |
f53d7ce3 JW |
989 | if (unlikely(mem_cgroup_event_ratelimit(memcg, |
990 | MEM_CGROUP_TARGET_THRESH))) { | |
bb4cc1a8 | 991 | bool do_softlimit; |
82b3f2a7 | 992 | bool do_numainfo __maybe_unused; |
f53d7ce3 | 993 | |
bb4cc1a8 AM |
994 | do_softlimit = mem_cgroup_event_ratelimit(memcg, |
995 | MEM_CGROUP_TARGET_SOFTLIMIT); | |
f53d7ce3 JW |
996 | #if MAX_NUMNODES > 1 |
997 | do_numainfo = mem_cgroup_event_ratelimit(memcg, | |
998 | MEM_CGROUP_TARGET_NUMAINFO); | |
999 | #endif | |
c0ff4b85 | 1000 | mem_cgroup_threshold(memcg); |
bb4cc1a8 AM |
1001 | if (unlikely(do_softlimit)) |
1002 | mem_cgroup_update_tree(memcg, page); | |
453a9bf3 | 1003 | #if MAX_NUMNODES > 1 |
f53d7ce3 | 1004 | if (unlikely(do_numainfo)) |
c0ff4b85 | 1005 | atomic_inc(&memcg->numainfo_events); |
453a9bf3 | 1006 | #endif |
0a31bc97 | 1007 | } |
d2265e6f KH |
1008 | } |
1009 | ||
cf475ad2 | 1010 | struct mem_cgroup *mem_cgroup_from_task(struct task_struct *p) |
78fb7466 | 1011 | { |
31a78f23 BS |
1012 | /* |
1013 | * mm_update_next_owner() may clear mm->owner to NULL | |
1014 | * if it races with swapoff, page migration, etc. | |
1015 | * So this can be called with p == NULL. | |
1016 | */ | |
1017 | if (unlikely(!p)) | |
1018 | return NULL; | |
1019 | ||
073219e9 | 1020 | return mem_cgroup_from_css(task_css(p, memory_cgrp_id)); |
78fb7466 PE |
1021 | } |
1022 | ||
df381975 | 1023 | static struct mem_cgroup *get_mem_cgroup_from_mm(struct mm_struct *mm) |
54595fe2 | 1024 | { |
c0ff4b85 | 1025 | struct mem_cgroup *memcg = NULL; |
0b7f569e | 1026 | |
54595fe2 KH |
1027 | rcu_read_lock(); |
1028 | do { | |
6f6acb00 MH |
1029 | /* |
1030 | * Page cache insertions can happen withou an | |
1031 | * actual mm context, e.g. during disk probing | |
1032 | * on boot, loopback IO, acct() writes etc. | |
1033 | */ | |
1034 | if (unlikely(!mm)) | |
df381975 | 1035 | memcg = root_mem_cgroup; |
6f6acb00 MH |
1036 | else { |
1037 | memcg = mem_cgroup_from_task(rcu_dereference(mm->owner)); | |
1038 | if (unlikely(!memcg)) | |
1039 | memcg = root_mem_cgroup; | |
1040 | } | |
ec903c0c | 1041 | } while (!css_tryget_online(&memcg->css)); |
54595fe2 | 1042 | rcu_read_unlock(); |
c0ff4b85 | 1043 | return memcg; |
54595fe2 KH |
1044 | } |
1045 | ||
5660048c JW |
1046 | /** |
1047 | * mem_cgroup_iter - iterate over memory cgroup hierarchy | |
1048 | * @root: hierarchy root | |
1049 | * @prev: previously returned memcg, NULL on first invocation | |
1050 | * @reclaim: cookie for shared reclaim walks, NULL for full walks | |
1051 | * | |
1052 | * Returns references to children of the hierarchy below @root, or | |
1053 | * @root itself, or %NULL after a full round-trip. | |
1054 | * | |
1055 | * Caller must pass the return value in @prev on subsequent | |
1056 | * invocations for reference counting, or use mem_cgroup_iter_break() | |
1057 | * to cancel a hierarchy walk before the round-trip is complete. | |
1058 | * | |
1059 | * Reclaimers can specify a zone and a priority level in @reclaim to | |
1060 | * divide up the memcgs in the hierarchy among all concurrent | |
1061 | * reclaimers operating on the same zone and priority. | |
1062 | */ | |
694fbc0f | 1063 | struct mem_cgroup *mem_cgroup_iter(struct mem_cgroup *root, |
5660048c | 1064 | struct mem_cgroup *prev, |
694fbc0f | 1065 | struct mem_cgroup_reclaim_cookie *reclaim) |
14067bb3 | 1066 | { |
5ac8fb31 JW |
1067 | struct reclaim_iter *uninitialized_var(iter); |
1068 | struct cgroup_subsys_state *css = NULL; | |
9f3a0d09 | 1069 | struct mem_cgroup *memcg = NULL; |
5ac8fb31 | 1070 | struct mem_cgroup *pos = NULL; |
711d3d2c | 1071 | |
694fbc0f AM |
1072 | if (mem_cgroup_disabled()) |
1073 | return NULL; | |
5660048c | 1074 | |
9f3a0d09 JW |
1075 | if (!root) |
1076 | root = root_mem_cgroup; | |
7d74b06f | 1077 | |
9f3a0d09 | 1078 | if (prev && !reclaim) |
5ac8fb31 | 1079 | pos = prev; |
14067bb3 | 1080 | |
9f3a0d09 JW |
1081 | if (!root->use_hierarchy && root != root_mem_cgroup) { |
1082 | if (prev) | |
5ac8fb31 | 1083 | goto out; |
694fbc0f | 1084 | return root; |
9f3a0d09 | 1085 | } |
14067bb3 | 1086 | |
542f85f9 | 1087 | rcu_read_lock(); |
5f578161 | 1088 | |
5ac8fb31 JW |
1089 | if (reclaim) { |
1090 | struct mem_cgroup_per_zone *mz; | |
1091 | ||
1092 | mz = mem_cgroup_zone_zoneinfo(root, reclaim->zone); | |
1093 | iter = &mz->iter[reclaim->priority]; | |
1094 | ||
1095 | if (prev && reclaim->generation != iter->generation) | |
1096 | goto out_unlock; | |
1097 | ||
1098 | do { | |
1099 | pos = ACCESS_ONCE(iter->position); | |
1100 | /* | |
1101 | * A racing update may change the position and | |
1102 | * put the last reference, hence css_tryget(), | |
1103 | * or retry to see the updated position. | |
1104 | */ | |
1105 | } while (pos && !css_tryget(&pos->css)); | |
1106 | } | |
1107 | ||
1108 | if (pos) | |
1109 | css = &pos->css; | |
1110 | ||
1111 | for (;;) { | |
1112 | css = css_next_descendant_pre(css, &root->css); | |
1113 | if (!css) { | |
1114 | /* | |
1115 | * Reclaimers share the hierarchy walk, and a | |
1116 | * new one might jump in right at the end of | |
1117 | * the hierarchy - make sure they see at least | |
1118 | * one group and restart from the beginning. | |
1119 | */ | |
1120 | if (!prev) | |
1121 | continue; | |
1122 | break; | |
527a5ec9 | 1123 | } |
7d74b06f | 1124 | |
5ac8fb31 JW |
1125 | /* |
1126 | * Verify the css and acquire a reference. The root | |
1127 | * is provided by the caller, so we know it's alive | |
1128 | * and kicking, and don't take an extra reference. | |
1129 | */ | |
1130 | memcg = mem_cgroup_from_css(css); | |
14067bb3 | 1131 | |
5ac8fb31 JW |
1132 | if (css == &root->css) |
1133 | break; | |
542f85f9 | 1134 | |
b2052564 | 1135 | if (css_tryget(css)) { |
5ac8fb31 JW |
1136 | /* |
1137 | * Make sure the memcg is initialized: | |
1138 | * mem_cgroup_css_online() orders the the | |
1139 | * initialization against setting the flag. | |
1140 | */ | |
1141 | if (smp_load_acquire(&memcg->initialized)) | |
1142 | break; | |
1143 | ||
1144 | css_put(css); | |
527a5ec9 | 1145 | } |
9f3a0d09 | 1146 | |
5ac8fb31 JW |
1147 | memcg = NULL; |
1148 | } | |
1149 | ||
1150 | if (reclaim) { | |
1151 | if (cmpxchg(&iter->position, pos, memcg) == pos) { | |
1152 | if (memcg) | |
1153 | css_get(&memcg->css); | |
1154 | if (pos) | |
1155 | css_put(&pos->css); | |
1156 | } | |
1157 | ||
1158 | /* | |
1159 | * pairs with css_tryget when dereferencing iter->position | |
1160 | * above. | |
1161 | */ | |
1162 | if (pos) | |
1163 | css_put(&pos->css); | |
1164 | ||
1165 | if (!memcg) | |
1166 | iter->generation++; | |
1167 | else if (!prev) | |
1168 | reclaim->generation = iter->generation; | |
9f3a0d09 | 1169 | } |
5ac8fb31 | 1170 | |
542f85f9 MH |
1171 | out_unlock: |
1172 | rcu_read_unlock(); | |
5ac8fb31 | 1173 | out: |
c40046f3 MH |
1174 | if (prev && prev != root) |
1175 | css_put(&prev->css); | |
1176 | ||
9f3a0d09 | 1177 | return memcg; |
14067bb3 | 1178 | } |
7d74b06f | 1179 | |
5660048c JW |
1180 | /** |
1181 | * mem_cgroup_iter_break - abort a hierarchy walk prematurely | |
1182 | * @root: hierarchy root | |
1183 | * @prev: last visited hierarchy member as returned by mem_cgroup_iter() | |
1184 | */ | |
1185 | void mem_cgroup_iter_break(struct mem_cgroup *root, | |
1186 | struct mem_cgroup *prev) | |
9f3a0d09 JW |
1187 | { |
1188 | if (!root) | |
1189 | root = root_mem_cgroup; | |
1190 | if (prev && prev != root) | |
1191 | css_put(&prev->css); | |
1192 | } | |
7d74b06f | 1193 | |
9f3a0d09 JW |
1194 | /* |
1195 | * Iteration constructs for visiting all cgroups (under a tree). If | |
1196 | * loops are exited prematurely (break), mem_cgroup_iter_break() must | |
1197 | * be used for reference counting. | |
1198 | */ | |
1199 | #define for_each_mem_cgroup_tree(iter, root) \ | |
527a5ec9 | 1200 | for (iter = mem_cgroup_iter(root, NULL, NULL); \ |
9f3a0d09 | 1201 | iter != NULL; \ |
527a5ec9 | 1202 | iter = mem_cgroup_iter(root, iter, NULL)) |
711d3d2c | 1203 | |
9f3a0d09 | 1204 | #define for_each_mem_cgroup(iter) \ |
527a5ec9 | 1205 | for (iter = mem_cgroup_iter(NULL, NULL, NULL); \ |
9f3a0d09 | 1206 | iter != NULL; \ |
527a5ec9 | 1207 | iter = mem_cgroup_iter(NULL, iter, NULL)) |
14067bb3 | 1208 | |
68ae564b | 1209 | void __mem_cgroup_count_vm_event(struct mm_struct *mm, enum vm_event_item idx) |
456f998e | 1210 | { |
c0ff4b85 | 1211 | struct mem_cgroup *memcg; |
456f998e | 1212 | |
456f998e | 1213 | rcu_read_lock(); |
c0ff4b85 R |
1214 | memcg = mem_cgroup_from_task(rcu_dereference(mm->owner)); |
1215 | if (unlikely(!memcg)) | |
456f998e YH |
1216 | goto out; |
1217 | ||
1218 | switch (idx) { | |
456f998e | 1219 | case PGFAULT: |
0e574a93 JW |
1220 | this_cpu_inc(memcg->stat->events[MEM_CGROUP_EVENTS_PGFAULT]); |
1221 | break; | |
1222 | case PGMAJFAULT: | |
1223 | this_cpu_inc(memcg->stat->events[MEM_CGROUP_EVENTS_PGMAJFAULT]); | |
456f998e YH |
1224 | break; |
1225 | default: | |
1226 | BUG(); | |
1227 | } | |
1228 | out: | |
1229 | rcu_read_unlock(); | |
1230 | } | |
68ae564b | 1231 | EXPORT_SYMBOL(__mem_cgroup_count_vm_event); |
456f998e | 1232 | |
925b7673 JW |
1233 | /** |
1234 | * mem_cgroup_zone_lruvec - get the lru list vector for a zone and memcg | |
1235 | * @zone: zone of the wanted lruvec | |
fa9add64 | 1236 | * @memcg: memcg of the wanted lruvec |
925b7673 JW |
1237 | * |
1238 | * Returns the lru list vector holding pages for the given @zone and | |
1239 | * @mem. This can be the global zone lruvec, if the memory controller | |
1240 | * is disabled. | |
1241 | */ | |
1242 | struct lruvec *mem_cgroup_zone_lruvec(struct zone *zone, | |
1243 | struct mem_cgroup *memcg) | |
1244 | { | |
1245 | struct mem_cgroup_per_zone *mz; | |
bea8c150 | 1246 | struct lruvec *lruvec; |
925b7673 | 1247 | |
bea8c150 HD |
1248 | if (mem_cgroup_disabled()) { |
1249 | lruvec = &zone->lruvec; | |
1250 | goto out; | |
1251 | } | |
925b7673 | 1252 | |
e231875b | 1253 | mz = mem_cgroup_zone_zoneinfo(memcg, zone); |
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; | |
925b7673 JW |
1264 | } |
1265 | ||
925b7673 | 1266 | /** |
fa9add64 | 1267 | * mem_cgroup_page_lruvec - return lruvec for adding an lru page |
925b7673 | 1268 | * @page: the page |
fa9add64 | 1269 | * @zone: zone of the page |
925b7673 | 1270 | */ |
fa9add64 | 1271 | struct lruvec *mem_cgroup_page_lruvec(struct page *page, struct zone *zone) |
08e552c6 | 1272 | { |
08e552c6 | 1273 | struct mem_cgroup_per_zone *mz; |
925b7673 JW |
1274 | struct mem_cgroup *memcg; |
1275 | struct page_cgroup *pc; | |
bea8c150 | 1276 | struct lruvec *lruvec; |
6d12e2d8 | 1277 | |
bea8c150 HD |
1278 | if (mem_cgroup_disabled()) { |
1279 | lruvec = &zone->lruvec; | |
1280 | goto out; | |
1281 | } | |
925b7673 | 1282 | |
08e552c6 | 1283 | pc = lookup_page_cgroup(page); |
38c5d72f | 1284 | memcg = pc->mem_cgroup; |
7512102c HD |
1285 | |
1286 | /* | |
fa9add64 | 1287 | * Surreptitiously switch any uncharged offlist page to root: |
7512102c HD |
1288 | * an uncharged page off lru does nothing to secure |
1289 | * its former mem_cgroup from sudden removal. | |
1290 | * | |
1291 | * Our caller holds lru_lock, and PageCgroupUsed is updated | |
1292 | * under page_cgroup lock: between them, they make all uses | |
1293 | * of pc->mem_cgroup safe. | |
1294 | */ | |
fa9add64 | 1295 | if (!PageLRU(page) && !PageCgroupUsed(pc) && memcg != root_mem_cgroup) |
7512102c HD |
1296 | pc->mem_cgroup = memcg = root_mem_cgroup; |
1297 | ||
e231875b | 1298 | mz = mem_cgroup_page_zoneinfo(memcg, page); |
bea8c150 HD |
1299 | lruvec = &mz->lruvec; |
1300 | out: | |
1301 | /* | |
1302 | * Since a node can be onlined after the mem_cgroup was created, | |
1303 | * we have to be prepared to initialize lruvec->zone here; | |
1304 | * and if offlined then reonlined, we need to reinitialize it. | |
1305 | */ | |
1306 | if (unlikely(lruvec->zone != zone)) | |
1307 | lruvec->zone = zone; | |
1308 | return lruvec; | |
08e552c6 | 1309 | } |
b69408e8 | 1310 | |
925b7673 | 1311 | /** |
fa9add64 HD |
1312 | * mem_cgroup_update_lru_size - account for adding or removing an lru page |
1313 | * @lruvec: mem_cgroup per zone lru vector | |
1314 | * @lru: index of lru list the page is sitting on | |
1315 | * @nr_pages: positive when adding or negative when removing | |
925b7673 | 1316 | * |
fa9add64 HD |
1317 | * This function must be called when a page is added to or removed from an |
1318 | * lru list. | |
3f58a829 | 1319 | */ |
fa9add64 HD |
1320 | void mem_cgroup_update_lru_size(struct lruvec *lruvec, enum lru_list lru, |
1321 | int nr_pages) | |
3f58a829 MK |
1322 | { |
1323 | struct mem_cgroup_per_zone *mz; | |
fa9add64 | 1324 | unsigned long *lru_size; |
3f58a829 MK |
1325 | |
1326 | if (mem_cgroup_disabled()) | |
1327 | return; | |
1328 | ||
fa9add64 HD |
1329 | mz = container_of(lruvec, struct mem_cgroup_per_zone, lruvec); |
1330 | lru_size = mz->lru_size + lru; | |
1331 | *lru_size += nr_pages; | |
1332 | VM_BUG_ON((long)(*lru_size) < 0); | |
08e552c6 | 1333 | } |
544122e5 | 1334 | |
3e92041d | 1335 | /* |
c0ff4b85 | 1336 | * Checks whether given mem is same or in the root_mem_cgroup's |
3e92041d MH |
1337 | * hierarchy subtree |
1338 | */ | |
c3ac9a8a JW |
1339 | bool __mem_cgroup_same_or_subtree(const struct mem_cgroup *root_memcg, |
1340 | struct mem_cgroup *memcg) | |
3e92041d | 1341 | { |
91c63734 JW |
1342 | if (root_memcg == memcg) |
1343 | return true; | |
3a981f48 | 1344 | if (!root_memcg->use_hierarchy || !memcg) |
91c63734 | 1345 | return false; |
b47f77b5 | 1346 | return cgroup_is_descendant(memcg->css.cgroup, root_memcg->css.cgroup); |
c3ac9a8a JW |
1347 | } |
1348 | ||
1349 | static bool mem_cgroup_same_or_subtree(const struct mem_cgroup *root_memcg, | |
1350 | struct mem_cgroup *memcg) | |
1351 | { | |
1352 | bool ret; | |
1353 | ||
91c63734 | 1354 | rcu_read_lock(); |
c3ac9a8a | 1355 | ret = __mem_cgroup_same_or_subtree(root_memcg, memcg); |
91c63734 JW |
1356 | rcu_read_unlock(); |
1357 | return ret; | |
3e92041d MH |
1358 | } |
1359 | ||
ffbdccf5 DR |
1360 | bool task_in_mem_cgroup(struct task_struct *task, |
1361 | const struct mem_cgroup *memcg) | |
4c4a2214 | 1362 | { |
0b7f569e | 1363 | struct mem_cgroup *curr = NULL; |
158e0a2d | 1364 | struct task_struct *p; |
ffbdccf5 | 1365 | bool ret; |
4c4a2214 | 1366 | |
158e0a2d | 1367 | p = find_lock_task_mm(task); |
de077d22 | 1368 | if (p) { |
df381975 | 1369 | curr = get_mem_cgroup_from_mm(p->mm); |
de077d22 DR |
1370 | task_unlock(p); |
1371 | } else { | |
1372 | /* | |
1373 | * All threads may have already detached their mm's, but the oom | |
1374 | * killer still needs to detect if they have already been oom | |
1375 | * killed to prevent needlessly killing additional tasks. | |
1376 | */ | |
ffbdccf5 | 1377 | rcu_read_lock(); |
de077d22 DR |
1378 | curr = mem_cgroup_from_task(task); |
1379 | if (curr) | |
1380 | css_get(&curr->css); | |
ffbdccf5 | 1381 | rcu_read_unlock(); |
de077d22 | 1382 | } |
d31f56db | 1383 | /* |
c0ff4b85 | 1384 | * We should check use_hierarchy of "memcg" not "curr". Because checking |
d31f56db | 1385 | * use_hierarchy of "curr" here make this function true if hierarchy is |
c0ff4b85 R |
1386 | * enabled in "curr" and "curr" is a child of "memcg" in *cgroup* |
1387 | * hierarchy(even if use_hierarchy is disabled in "memcg"). | |
d31f56db | 1388 | */ |
c0ff4b85 | 1389 | ret = mem_cgroup_same_or_subtree(memcg, curr); |
0b7f569e | 1390 | css_put(&curr->css); |
4c4a2214 DR |
1391 | return ret; |
1392 | } | |
1393 | ||
c56d5c7d | 1394 | int mem_cgroup_inactive_anon_is_low(struct lruvec *lruvec) |
14797e23 | 1395 | { |
9b272977 | 1396 | unsigned long inactive_ratio; |
14797e23 | 1397 | unsigned long inactive; |
9b272977 | 1398 | unsigned long active; |
c772be93 | 1399 | unsigned long gb; |
14797e23 | 1400 | |
4d7dcca2 HD |
1401 | inactive = mem_cgroup_get_lru_size(lruvec, LRU_INACTIVE_ANON); |
1402 | active = mem_cgroup_get_lru_size(lruvec, LRU_ACTIVE_ANON); | |
14797e23 | 1403 | |
c772be93 KM |
1404 | gb = (inactive + active) >> (30 - PAGE_SHIFT); |
1405 | if (gb) | |
1406 | inactive_ratio = int_sqrt(10 * gb); | |
1407 | else | |
1408 | inactive_ratio = 1; | |
1409 | ||
9b272977 | 1410 | return inactive * inactive_ratio < active; |
14797e23 KM |
1411 | } |
1412 | ||
3e32cb2e | 1413 | #define mem_cgroup_from_counter(counter, member) \ |
6d61ef40 BS |
1414 | container_of(counter, struct mem_cgroup, member) |
1415 | ||
19942822 | 1416 | /** |
9d11ea9f | 1417 | * mem_cgroup_margin - calculate chargeable space of a memory cgroup |
dad7557e | 1418 | * @memcg: the memory cgroup |
19942822 | 1419 | * |
9d11ea9f | 1420 | * Returns the maximum amount of memory @mem can be charged with, in |
7ec99d62 | 1421 | * pages. |
19942822 | 1422 | */ |
c0ff4b85 | 1423 | static unsigned long mem_cgroup_margin(struct mem_cgroup *memcg) |
19942822 | 1424 | { |
3e32cb2e JW |
1425 | unsigned long margin = 0; |
1426 | unsigned long count; | |
1427 | unsigned long limit; | |
9d11ea9f | 1428 | |
3e32cb2e JW |
1429 | count = page_counter_read(&memcg->memory); |
1430 | limit = ACCESS_ONCE(memcg->memory.limit); | |
1431 | if (count < limit) | |
1432 | margin = limit - count; | |
1433 | ||
1434 | if (do_swap_account) { | |
1435 | count = page_counter_read(&memcg->memsw); | |
1436 | limit = ACCESS_ONCE(memcg->memsw.limit); | |
1437 | if (count <= limit) | |
1438 | margin = min(margin, limit - count); | |
1439 | } | |
1440 | ||
1441 | return margin; | |
19942822 JW |
1442 | } |
1443 | ||
1f4c025b | 1444 | int mem_cgroup_swappiness(struct mem_cgroup *memcg) |
a7885eb8 | 1445 | { |
a7885eb8 | 1446 | /* root ? */ |
14208b0e | 1447 | if (mem_cgroup_disabled() || !memcg->css.parent) |
a7885eb8 KM |
1448 | return vm_swappiness; |
1449 | ||
bf1ff263 | 1450 | return memcg->swappiness; |
a7885eb8 KM |
1451 | } |
1452 | ||
619d094b KH |
1453 | /* |
1454 | * memcg->moving_account is used for checking possibility that some thread is | |
1455 | * calling move_account(). When a thread on CPU-A starts moving pages under | |
1456 | * a memcg, other threads should check memcg->moving_account under | |
1457 | * rcu_read_lock(), like this: | |
1458 | * | |
1459 | * CPU-A CPU-B | |
1460 | * rcu_read_lock() | |
1461 | * memcg->moving_account+1 if (memcg->mocing_account) | |
1462 | * take heavy locks. | |
1463 | * synchronize_rcu() update something. | |
1464 | * rcu_read_unlock() | |
1465 | * start move here. | |
1466 | */ | |
4331f7d3 | 1467 | |
c0ff4b85 | 1468 | static void mem_cgroup_start_move(struct mem_cgroup *memcg) |
32047e2a | 1469 | { |
619d094b | 1470 | atomic_inc(&memcg->moving_account); |
32047e2a KH |
1471 | synchronize_rcu(); |
1472 | } | |
1473 | ||
c0ff4b85 | 1474 | static void mem_cgroup_end_move(struct mem_cgroup *memcg) |
32047e2a | 1475 | { |
619d094b KH |
1476 | /* |
1477 | * Now, mem_cgroup_clear_mc() may call this function with NULL. | |
1478 | * We check NULL in callee rather than caller. | |
1479 | */ | |
d7365e78 | 1480 | if (memcg) |
619d094b | 1481 | atomic_dec(&memcg->moving_account); |
32047e2a | 1482 | } |
619d094b | 1483 | |
32047e2a | 1484 | /* |
bdcbb659 | 1485 | * A routine for checking "mem" is under move_account() or not. |
32047e2a | 1486 | * |
bdcbb659 QH |
1487 | * Checking a cgroup is mc.from or mc.to or under hierarchy of |
1488 | * moving cgroups. This is for waiting at high-memory pressure | |
1489 | * caused by "move". | |
32047e2a | 1490 | */ |
c0ff4b85 | 1491 | static bool mem_cgroup_under_move(struct mem_cgroup *memcg) |
4b534334 | 1492 | { |
2bd9bb20 KH |
1493 | struct mem_cgroup *from; |
1494 | struct mem_cgroup *to; | |
4b534334 | 1495 | bool ret = false; |
2bd9bb20 KH |
1496 | /* |
1497 | * Unlike task_move routines, we access mc.to, mc.from not under | |
1498 | * mutual exclusion by cgroup_mutex. Here, we take spinlock instead. | |
1499 | */ | |
1500 | spin_lock(&mc.lock); | |
1501 | from = mc.from; | |
1502 | to = mc.to; | |
1503 | if (!from) | |
1504 | goto unlock; | |
3e92041d | 1505 | |
c0ff4b85 R |
1506 | ret = mem_cgroup_same_or_subtree(memcg, from) |
1507 | || mem_cgroup_same_or_subtree(memcg, to); | |
2bd9bb20 KH |
1508 | unlock: |
1509 | spin_unlock(&mc.lock); | |
4b534334 KH |
1510 | return ret; |
1511 | } | |
1512 | ||
c0ff4b85 | 1513 | static bool mem_cgroup_wait_acct_move(struct mem_cgroup *memcg) |
4b534334 KH |
1514 | { |
1515 | if (mc.moving_task && current != mc.moving_task) { | |
c0ff4b85 | 1516 | if (mem_cgroup_under_move(memcg)) { |
4b534334 KH |
1517 | DEFINE_WAIT(wait); |
1518 | prepare_to_wait(&mc.waitq, &wait, TASK_INTERRUPTIBLE); | |
1519 | /* moving charge context might have finished. */ | |
1520 | if (mc.moving_task) | |
1521 | schedule(); | |
1522 | finish_wait(&mc.waitq, &wait); | |
1523 | return true; | |
1524 | } | |
1525 | } | |
1526 | return false; | |
1527 | } | |
1528 | ||
312734c0 KH |
1529 | /* |
1530 | * Take this lock when | |
1531 | * - a code tries to modify page's memcg while it's USED. | |
1532 | * - a code tries to modify page state accounting in a memcg. | |
312734c0 KH |
1533 | */ |
1534 | static void move_lock_mem_cgroup(struct mem_cgroup *memcg, | |
1535 | unsigned long *flags) | |
1536 | { | |
1537 | spin_lock_irqsave(&memcg->move_lock, *flags); | |
1538 | } | |
1539 | ||
1540 | static void move_unlock_mem_cgroup(struct mem_cgroup *memcg, | |
1541 | unsigned long *flags) | |
1542 | { | |
1543 | spin_unlock_irqrestore(&memcg->move_lock, *flags); | |
1544 | } | |
1545 | ||
58cf188e | 1546 | #define K(x) ((x) << (PAGE_SHIFT-10)) |
e222432b | 1547 | /** |
58cf188e | 1548 | * mem_cgroup_print_oom_info: Print OOM information relevant to memory controller. |
e222432b BS |
1549 | * @memcg: The memory cgroup that went over limit |
1550 | * @p: Task that is going to be killed | |
1551 | * | |
1552 | * NOTE: @memcg and @p's mem_cgroup can be different when hierarchy is | |
1553 | * enabled | |
1554 | */ | |
1555 | void mem_cgroup_print_oom_info(struct mem_cgroup *memcg, struct task_struct *p) | |
1556 | { | |
e61734c5 | 1557 | /* oom_info_lock ensures that parallel ooms do not interleave */ |
08088cb9 | 1558 | static DEFINE_MUTEX(oom_info_lock); |
58cf188e SZ |
1559 | struct mem_cgroup *iter; |
1560 | unsigned int i; | |
e222432b | 1561 | |
58cf188e | 1562 | if (!p) |
e222432b BS |
1563 | return; |
1564 | ||
08088cb9 | 1565 | mutex_lock(&oom_info_lock); |
e222432b BS |
1566 | rcu_read_lock(); |
1567 | ||
e61734c5 TH |
1568 | pr_info("Task in "); |
1569 | pr_cont_cgroup_path(task_cgroup(p, memory_cgrp_id)); | |
1570 | pr_info(" killed as a result of limit of "); | |
1571 | pr_cont_cgroup_path(memcg->css.cgroup); | |
1572 | pr_info("\n"); | |
e222432b | 1573 | |
e222432b BS |
1574 | rcu_read_unlock(); |
1575 | ||
3e32cb2e JW |
1576 | pr_info("memory: usage %llukB, limit %llukB, failcnt %lu\n", |
1577 | K((u64)page_counter_read(&memcg->memory)), | |
1578 | K((u64)memcg->memory.limit), memcg->memory.failcnt); | |
1579 | pr_info("memory+swap: usage %llukB, limit %llukB, failcnt %lu\n", | |
1580 | K((u64)page_counter_read(&memcg->memsw)), | |
1581 | K((u64)memcg->memsw.limit), memcg->memsw.failcnt); | |
1582 | pr_info("kmem: usage %llukB, limit %llukB, failcnt %lu\n", | |
1583 | K((u64)page_counter_read(&memcg->kmem)), | |
1584 | K((u64)memcg->kmem.limit), memcg->kmem.failcnt); | |
58cf188e SZ |
1585 | |
1586 | for_each_mem_cgroup_tree(iter, memcg) { | |
e61734c5 TH |
1587 | pr_info("Memory cgroup stats for "); |
1588 | pr_cont_cgroup_path(iter->css.cgroup); | |
58cf188e SZ |
1589 | pr_cont(":"); |
1590 | ||
1591 | for (i = 0; i < MEM_CGROUP_STAT_NSTATS; i++) { | |
1592 | if (i == MEM_CGROUP_STAT_SWAP && !do_swap_account) | |
1593 | continue; | |
1594 | pr_cont(" %s:%ldKB", mem_cgroup_stat_names[i], | |
1595 | K(mem_cgroup_read_stat(iter, i))); | |
1596 | } | |
1597 | ||
1598 | for (i = 0; i < NR_LRU_LISTS; i++) | |
1599 | pr_cont(" %s:%luKB", mem_cgroup_lru_names[i], | |
1600 | K(mem_cgroup_nr_lru_pages(iter, BIT(i)))); | |
1601 | ||
1602 | pr_cont("\n"); | |
1603 | } | |
08088cb9 | 1604 | mutex_unlock(&oom_info_lock); |
e222432b BS |
1605 | } |
1606 | ||
81d39c20 KH |
1607 | /* |
1608 | * This function returns the number of memcg under hierarchy tree. Returns | |
1609 | * 1(self count) if no children. | |
1610 | */ | |
c0ff4b85 | 1611 | static int mem_cgroup_count_children(struct mem_cgroup *memcg) |
81d39c20 KH |
1612 | { |
1613 | int num = 0; | |
7d74b06f KH |
1614 | struct mem_cgroup *iter; |
1615 | ||
c0ff4b85 | 1616 | for_each_mem_cgroup_tree(iter, memcg) |
7d74b06f | 1617 | num++; |
81d39c20 KH |
1618 | return num; |
1619 | } | |
1620 | ||
a63d83f4 DR |
1621 | /* |
1622 | * Return the memory (and swap, if configured) limit for a memcg. | |
1623 | */ | |
3e32cb2e | 1624 | static unsigned long mem_cgroup_get_limit(struct mem_cgroup *memcg) |
a63d83f4 | 1625 | { |
3e32cb2e | 1626 | unsigned long limit; |
a63d83f4 | 1627 | |
3e32cb2e | 1628 | limit = memcg->memory.limit; |
9a5a8f19 | 1629 | if (mem_cgroup_swappiness(memcg)) { |
3e32cb2e | 1630 | unsigned long memsw_limit; |
9a5a8f19 | 1631 | |
3e32cb2e JW |
1632 | memsw_limit = memcg->memsw.limit; |
1633 | limit = min(limit + total_swap_pages, memsw_limit); | |
9a5a8f19 | 1634 | } |
9a5a8f19 | 1635 | return limit; |
a63d83f4 DR |
1636 | } |
1637 | ||
19965460 DR |
1638 | static void mem_cgroup_out_of_memory(struct mem_cgroup *memcg, gfp_t gfp_mask, |
1639 | int order) | |
9cbb78bb DR |
1640 | { |
1641 | struct mem_cgroup *iter; | |
1642 | unsigned long chosen_points = 0; | |
1643 | unsigned long totalpages; | |
1644 | unsigned int points = 0; | |
1645 | struct task_struct *chosen = NULL; | |
1646 | ||
876aafbf | 1647 | /* |
465adcf1 DR |
1648 | * If current has a pending SIGKILL or is exiting, then automatically |
1649 | * select it. The goal is to allow it to allocate so that it may | |
1650 | * quickly exit and free its memory. | |
876aafbf | 1651 | */ |
465adcf1 | 1652 | if (fatal_signal_pending(current) || current->flags & PF_EXITING) { |
876aafbf DR |
1653 | set_thread_flag(TIF_MEMDIE); |
1654 | return; | |
1655 | } | |
1656 | ||
1657 | check_panic_on_oom(CONSTRAINT_MEMCG, gfp_mask, order, NULL); | |
3e32cb2e | 1658 | totalpages = mem_cgroup_get_limit(memcg) ? : 1; |
9cbb78bb | 1659 | for_each_mem_cgroup_tree(iter, memcg) { |
72ec7029 | 1660 | struct css_task_iter it; |
9cbb78bb DR |
1661 | struct task_struct *task; |
1662 | ||
72ec7029 TH |
1663 | css_task_iter_start(&iter->css, &it); |
1664 | while ((task = css_task_iter_next(&it))) { | |
9cbb78bb DR |
1665 | switch (oom_scan_process_thread(task, totalpages, NULL, |
1666 | false)) { | |
1667 | case OOM_SCAN_SELECT: | |
1668 | if (chosen) | |
1669 | put_task_struct(chosen); | |
1670 | chosen = task; | |
1671 | chosen_points = ULONG_MAX; | |
1672 | get_task_struct(chosen); | |
1673 | /* fall through */ | |
1674 | case OOM_SCAN_CONTINUE: | |
1675 | continue; | |
1676 | case OOM_SCAN_ABORT: | |
72ec7029 | 1677 | css_task_iter_end(&it); |
9cbb78bb DR |
1678 | mem_cgroup_iter_break(memcg, iter); |
1679 | if (chosen) | |
1680 | put_task_struct(chosen); | |
1681 | return; | |
1682 | case OOM_SCAN_OK: | |
1683 | break; | |
1684 | }; | |
1685 | points = oom_badness(task, memcg, NULL, totalpages); | |
d49ad935 DR |
1686 | if (!points || points < chosen_points) |
1687 | continue; | |
1688 | /* Prefer thread group leaders for display purposes */ | |
1689 | if (points == chosen_points && | |
1690 | thread_group_leader(chosen)) | |
1691 | continue; | |
1692 | ||
1693 | if (chosen) | |
1694 | put_task_struct(chosen); | |
1695 | chosen = task; | |
1696 | chosen_points = points; | |
1697 | get_task_struct(chosen); | |
9cbb78bb | 1698 | } |
72ec7029 | 1699 | css_task_iter_end(&it); |
9cbb78bb DR |
1700 | } |
1701 | ||
1702 | if (!chosen) | |
1703 | return; | |
1704 | points = chosen_points * 1000 / totalpages; | |
9cbb78bb DR |
1705 | oom_kill_process(chosen, gfp_mask, order, points, totalpages, memcg, |
1706 | NULL, "Memory cgroup out of memory"); | |
9cbb78bb DR |
1707 | } |
1708 | ||
4d0c066d KH |
1709 | /** |
1710 | * test_mem_cgroup_node_reclaimable | |
dad7557e | 1711 | * @memcg: the target memcg |
4d0c066d KH |
1712 | * @nid: the node ID to be checked. |
1713 | * @noswap : specify true here if the user wants flle only information. | |
1714 | * | |
1715 | * This function returns whether the specified memcg contains any | |
1716 | * reclaimable pages on a node. Returns true if there are any reclaimable | |
1717 | * pages in the node. | |
1718 | */ | |
c0ff4b85 | 1719 | static bool test_mem_cgroup_node_reclaimable(struct mem_cgroup *memcg, |
4d0c066d KH |
1720 | int nid, bool noswap) |
1721 | { | |
c0ff4b85 | 1722 | if (mem_cgroup_node_nr_lru_pages(memcg, nid, LRU_ALL_FILE)) |
4d0c066d KH |
1723 | return true; |
1724 | if (noswap || !total_swap_pages) | |
1725 | return false; | |
c0ff4b85 | 1726 | if (mem_cgroup_node_nr_lru_pages(memcg, nid, LRU_ALL_ANON)) |
4d0c066d KH |
1727 | return true; |
1728 | return false; | |
1729 | ||
1730 | } | |
bb4cc1a8 | 1731 | #if MAX_NUMNODES > 1 |
889976db YH |
1732 | |
1733 | /* | |
1734 | * Always updating the nodemask is not very good - even if we have an empty | |
1735 | * list or the wrong list here, we can start from some node and traverse all | |
1736 | * nodes based on the zonelist. So update the list loosely once per 10 secs. | |
1737 | * | |
1738 | */ | |
c0ff4b85 | 1739 | static void mem_cgroup_may_update_nodemask(struct mem_cgroup *memcg) |
889976db YH |
1740 | { |
1741 | int nid; | |
453a9bf3 KH |
1742 | /* |
1743 | * numainfo_events > 0 means there was at least NUMAINFO_EVENTS_TARGET | |
1744 | * pagein/pageout changes since the last update. | |
1745 | */ | |
c0ff4b85 | 1746 | if (!atomic_read(&memcg->numainfo_events)) |
453a9bf3 | 1747 | return; |
c0ff4b85 | 1748 | if (atomic_inc_return(&memcg->numainfo_updating) > 1) |
889976db YH |
1749 | return; |
1750 | ||
889976db | 1751 | /* make a nodemask where this memcg uses memory from */ |
31aaea4a | 1752 | memcg->scan_nodes = node_states[N_MEMORY]; |
889976db | 1753 | |
31aaea4a | 1754 | for_each_node_mask(nid, node_states[N_MEMORY]) { |
889976db | 1755 | |
c0ff4b85 R |
1756 | if (!test_mem_cgroup_node_reclaimable(memcg, nid, false)) |
1757 | node_clear(nid, memcg->scan_nodes); | |
889976db | 1758 | } |
453a9bf3 | 1759 | |
c0ff4b85 R |
1760 | atomic_set(&memcg->numainfo_events, 0); |
1761 | atomic_set(&memcg->numainfo_updating, 0); | |
889976db YH |
1762 | } |
1763 | ||
1764 | /* | |
1765 | * Selecting a node where we start reclaim from. Because what we need is just | |
1766 | * reducing usage counter, start from anywhere is O,K. Considering | |
1767 | * memory reclaim from current node, there are pros. and cons. | |
1768 | * | |
1769 | * Freeing memory from current node means freeing memory from a node which | |
1770 | * we'll use or we've used. So, it may make LRU bad. And if several threads | |
1771 | * hit limits, it will see a contention on a node. But freeing from remote | |
1772 | * node means more costs for memory reclaim because of memory latency. | |
1773 | * | |
1774 | * Now, we use round-robin. Better algorithm is welcomed. | |
1775 | */ | |
c0ff4b85 | 1776 | int mem_cgroup_select_victim_node(struct mem_cgroup *memcg) |
889976db YH |
1777 | { |
1778 | int node; | |
1779 | ||
c0ff4b85 R |
1780 | mem_cgroup_may_update_nodemask(memcg); |
1781 | node = memcg->last_scanned_node; | |
889976db | 1782 | |
c0ff4b85 | 1783 | node = next_node(node, memcg->scan_nodes); |
889976db | 1784 | if (node == MAX_NUMNODES) |
c0ff4b85 | 1785 | node = first_node(memcg->scan_nodes); |
889976db YH |
1786 | /* |
1787 | * We call this when we hit limit, not when pages are added to LRU. | |
1788 | * No LRU may hold pages because all pages are UNEVICTABLE or | |
1789 | * memcg is too small and all pages are not on LRU. In that case, | |
1790 | * we use curret node. | |
1791 | */ | |
1792 | if (unlikely(node == MAX_NUMNODES)) | |
1793 | node = numa_node_id(); | |
1794 | ||
c0ff4b85 | 1795 | memcg->last_scanned_node = node; |
889976db YH |
1796 | return node; |
1797 | } | |
1798 | ||
bb4cc1a8 AM |
1799 | /* |
1800 | * Check all nodes whether it contains reclaimable pages or not. | |
1801 | * For quick scan, we make use of scan_nodes. This will allow us to skip | |
1802 | * unused nodes. But scan_nodes is lazily updated and may not cotain | |
1803 | * enough new information. We need to do double check. | |
1804 | */ | |
1805 | static bool mem_cgroup_reclaimable(struct mem_cgroup *memcg, bool noswap) | |
1806 | { | |
1807 | int nid; | |
1808 | ||
1809 | /* | |
1810 | * quick check...making use of scan_node. | |
1811 | * We can skip unused nodes. | |
1812 | */ | |
1813 | if (!nodes_empty(memcg->scan_nodes)) { | |
1814 | for (nid = first_node(memcg->scan_nodes); | |
1815 | nid < MAX_NUMNODES; | |
1816 | nid = next_node(nid, memcg->scan_nodes)) { | |
1817 | ||
1818 | if (test_mem_cgroup_node_reclaimable(memcg, nid, noswap)) | |
1819 | return true; | |
1820 | } | |
1821 | } | |
1822 | /* | |
1823 | * Check rest of nodes. | |
1824 | */ | |
1825 | for_each_node_state(nid, N_MEMORY) { | |
1826 | if (node_isset(nid, memcg->scan_nodes)) | |
1827 | continue; | |
1828 | if (test_mem_cgroup_node_reclaimable(memcg, nid, noswap)) | |
1829 | return true; | |
1830 | } | |
1831 | return false; | |
1832 | } | |
1833 | ||
889976db | 1834 | #else |
c0ff4b85 | 1835 | int mem_cgroup_select_victim_node(struct mem_cgroup *memcg) |
889976db YH |
1836 | { |
1837 | return 0; | |
1838 | } | |
4d0c066d | 1839 | |
bb4cc1a8 AM |
1840 | static bool mem_cgroup_reclaimable(struct mem_cgroup *memcg, bool noswap) |
1841 | { | |
1842 | return test_mem_cgroup_node_reclaimable(memcg, 0, noswap); | |
1843 | } | |
889976db YH |
1844 | #endif |
1845 | ||
0608f43d AM |
1846 | static int mem_cgroup_soft_reclaim(struct mem_cgroup *root_memcg, |
1847 | struct zone *zone, | |
1848 | gfp_t gfp_mask, | |
1849 | unsigned long *total_scanned) | |
1850 | { | |
1851 | struct mem_cgroup *victim = NULL; | |
1852 | int total = 0; | |
1853 | int loop = 0; | |
1854 | unsigned long excess; | |
1855 | unsigned long nr_scanned; | |
1856 | struct mem_cgroup_reclaim_cookie reclaim = { | |
1857 | .zone = zone, | |
1858 | .priority = 0, | |
1859 | }; | |
1860 | ||
3e32cb2e | 1861 | excess = soft_limit_excess(root_memcg); |
0608f43d AM |
1862 | |
1863 | while (1) { | |
1864 | victim = mem_cgroup_iter(root_memcg, victim, &reclaim); | |
1865 | if (!victim) { | |
1866 | loop++; | |
1867 | if (loop >= 2) { | |
1868 | /* | |
1869 | * If we have not been able to reclaim | |
1870 | * anything, it might because there are | |
1871 | * no reclaimable pages under this hierarchy | |
1872 | */ | |
1873 | if (!total) | |
1874 | break; | |
1875 | /* | |
1876 | * We want to do more targeted reclaim. | |
1877 | * excess >> 2 is not to excessive so as to | |
1878 | * reclaim too much, nor too less that we keep | |
1879 | * coming back to reclaim from this cgroup | |
1880 | */ | |
1881 | if (total >= (excess >> 2) || | |
1882 | (loop > MEM_CGROUP_MAX_RECLAIM_LOOPS)) | |
1883 | break; | |
1884 | } | |
1885 | continue; | |
1886 | } | |
1887 | if (!mem_cgroup_reclaimable(victim, false)) | |
1888 | continue; | |
1889 | total += mem_cgroup_shrink_node_zone(victim, gfp_mask, false, | |
1890 | zone, &nr_scanned); | |
1891 | *total_scanned += nr_scanned; | |
3e32cb2e | 1892 | if (!soft_limit_excess(root_memcg)) |
0608f43d | 1893 | break; |
6d61ef40 | 1894 | } |
0608f43d AM |
1895 | mem_cgroup_iter_break(root_memcg, victim); |
1896 | return total; | |
6d61ef40 BS |
1897 | } |
1898 | ||
0056f4e6 JW |
1899 | #ifdef CONFIG_LOCKDEP |
1900 | static struct lockdep_map memcg_oom_lock_dep_map = { | |
1901 | .name = "memcg_oom_lock", | |
1902 | }; | |
1903 | #endif | |
1904 | ||
fb2a6fc5 JW |
1905 | static DEFINE_SPINLOCK(memcg_oom_lock); |
1906 | ||
867578cb KH |
1907 | /* |
1908 | * Check OOM-Killer is already running under our hierarchy. | |
1909 | * If someone is running, return false. | |
1910 | */ | |
fb2a6fc5 | 1911 | static bool mem_cgroup_oom_trylock(struct mem_cgroup *memcg) |
867578cb | 1912 | { |
79dfdacc | 1913 | struct mem_cgroup *iter, *failed = NULL; |
a636b327 | 1914 | |
fb2a6fc5 JW |
1915 | spin_lock(&memcg_oom_lock); |
1916 | ||
9f3a0d09 | 1917 | for_each_mem_cgroup_tree(iter, memcg) { |
23751be0 | 1918 | if (iter->oom_lock) { |
79dfdacc MH |
1919 | /* |
1920 | * this subtree of our hierarchy is already locked | |
1921 | * so we cannot give a lock. | |
1922 | */ | |
79dfdacc | 1923 | failed = iter; |
9f3a0d09 JW |
1924 | mem_cgroup_iter_break(memcg, iter); |
1925 | break; | |
23751be0 JW |
1926 | } else |
1927 | iter->oom_lock = true; | |
7d74b06f | 1928 | } |
867578cb | 1929 | |
fb2a6fc5 JW |
1930 | if (failed) { |
1931 | /* | |
1932 | * OK, we failed to lock the whole subtree so we have | |
1933 | * to clean up what we set up to the failing subtree | |
1934 | */ | |
1935 | for_each_mem_cgroup_tree(iter, memcg) { | |
1936 | if (iter == failed) { | |
1937 | mem_cgroup_iter_break(memcg, iter); | |
1938 | break; | |
1939 | } | |
1940 | iter->oom_lock = false; | |
79dfdacc | 1941 | } |
0056f4e6 JW |
1942 | } else |
1943 | mutex_acquire(&memcg_oom_lock_dep_map, 0, 1, _RET_IP_); | |
fb2a6fc5 JW |
1944 | |
1945 | spin_unlock(&memcg_oom_lock); | |
1946 | ||
1947 | return !failed; | |
a636b327 | 1948 | } |
0b7f569e | 1949 | |
fb2a6fc5 | 1950 | static void mem_cgroup_oom_unlock(struct mem_cgroup *memcg) |
0b7f569e | 1951 | { |
7d74b06f KH |
1952 | struct mem_cgroup *iter; |
1953 | ||
fb2a6fc5 | 1954 | spin_lock(&memcg_oom_lock); |
0056f4e6 | 1955 | mutex_release(&memcg_oom_lock_dep_map, 1, _RET_IP_); |
c0ff4b85 | 1956 | for_each_mem_cgroup_tree(iter, memcg) |
79dfdacc | 1957 | iter->oom_lock = false; |
fb2a6fc5 | 1958 | spin_unlock(&memcg_oom_lock); |
79dfdacc MH |
1959 | } |
1960 | ||
c0ff4b85 | 1961 | static void mem_cgroup_mark_under_oom(struct mem_cgroup *memcg) |
79dfdacc MH |
1962 | { |
1963 | struct mem_cgroup *iter; | |
1964 | ||
c0ff4b85 | 1965 | for_each_mem_cgroup_tree(iter, memcg) |
79dfdacc MH |
1966 | atomic_inc(&iter->under_oom); |
1967 | } | |
1968 | ||
c0ff4b85 | 1969 | static void mem_cgroup_unmark_under_oom(struct mem_cgroup *memcg) |
79dfdacc MH |
1970 | { |
1971 | struct mem_cgroup *iter; | |
1972 | ||
867578cb KH |
1973 | /* |
1974 | * When a new child is created while the hierarchy is under oom, | |
1975 | * mem_cgroup_oom_lock() may not be called. We have to use | |
1976 | * atomic_add_unless() here. | |
1977 | */ | |
c0ff4b85 | 1978 | for_each_mem_cgroup_tree(iter, memcg) |
79dfdacc | 1979 | atomic_add_unless(&iter->under_oom, -1, 0); |
0b7f569e KH |
1980 | } |
1981 | ||
867578cb KH |
1982 | static DECLARE_WAIT_QUEUE_HEAD(memcg_oom_waitq); |
1983 | ||
dc98df5a | 1984 | struct oom_wait_info { |
d79154bb | 1985 | struct mem_cgroup *memcg; |
dc98df5a KH |
1986 | wait_queue_t wait; |
1987 | }; | |
1988 | ||
1989 | static int memcg_oom_wake_function(wait_queue_t *wait, | |
1990 | unsigned mode, int sync, void *arg) | |
1991 | { | |
d79154bb HD |
1992 | struct mem_cgroup *wake_memcg = (struct mem_cgroup *)arg; |
1993 | struct mem_cgroup *oom_wait_memcg; | |
dc98df5a KH |
1994 | struct oom_wait_info *oom_wait_info; |
1995 | ||
1996 | oom_wait_info = container_of(wait, struct oom_wait_info, wait); | |
d79154bb | 1997 | oom_wait_memcg = oom_wait_info->memcg; |
dc98df5a | 1998 | |
dc98df5a | 1999 | /* |
d79154bb | 2000 | * Both of oom_wait_info->memcg and wake_memcg are stable under us. |
dc98df5a KH |
2001 | * Then we can use css_is_ancestor without taking care of RCU. |
2002 | */ | |
c0ff4b85 R |
2003 | if (!mem_cgroup_same_or_subtree(oom_wait_memcg, wake_memcg) |
2004 | && !mem_cgroup_same_or_subtree(wake_memcg, oom_wait_memcg)) | |
dc98df5a | 2005 | return 0; |
dc98df5a KH |
2006 | return autoremove_wake_function(wait, mode, sync, arg); |
2007 | } | |
2008 | ||
c0ff4b85 | 2009 | static void memcg_wakeup_oom(struct mem_cgroup *memcg) |
dc98df5a | 2010 | { |
3812c8c8 | 2011 | atomic_inc(&memcg->oom_wakeups); |
c0ff4b85 R |
2012 | /* for filtering, pass "memcg" as argument. */ |
2013 | __wake_up(&memcg_oom_waitq, TASK_NORMAL, 0, memcg); | |
dc98df5a KH |
2014 | } |
2015 | ||
c0ff4b85 | 2016 | static void memcg_oom_recover(struct mem_cgroup *memcg) |
3c11ecf4 | 2017 | { |
c0ff4b85 R |
2018 | if (memcg && atomic_read(&memcg->under_oom)) |
2019 | memcg_wakeup_oom(memcg); | |
3c11ecf4 KH |
2020 | } |
2021 | ||
3812c8c8 | 2022 | static void mem_cgroup_oom(struct mem_cgroup *memcg, gfp_t mask, int order) |
0b7f569e | 2023 | { |
3812c8c8 JW |
2024 | if (!current->memcg_oom.may_oom) |
2025 | return; | |
867578cb | 2026 | /* |
49426420 JW |
2027 | * We are in the middle of the charge context here, so we |
2028 | * don't want to block when potentially sitting on a callstack | |
2029 | * that holds all kinds of filesystem and mm locks. | |
2030 | * | |
2031 | * Also, the caller may handle a failed allocation gracefully | |
2032 | * (like optional page cache readahead) and so an OOM killer | |
2033 | * invocation might not even be necessary. | |
2034 | * | |
2035 | * That's why we don't do anything here except remember the | |
2036 | * OOM context and then deal with it at the end of the page | |
2037 | * fault when the stack is unwound, the locks are released, | |
2038 | * and when we know whether the fault was overall successful. | |
867578cb | 2039 | */ |
49426420 JW |
2040 | css_get(&memcg->css); |
2041 | current->memcg_oom.memcg = memcg; | |
2042 | current->memcg_oom.gfp_mask = mask; | |
2043 | current->memcg_oom.order = order; | |
3812c8c8 JW |
2044 | } |
2045 | ||
2046 | /** | |
2047 | * mem_cgroup_oom_synchronize - complete memcg OOM handling | |
49426420 | 2048 | * @handle: actually kill/wait or just clean up the OOM state |
3812c8c8 | 2049 | * |
49426420 JW |
2050 | * This has to be called at the end of a page fault if the memcg OOM |
2051 | * handler was enabled. | |
3812c8c8 | 2052 | * |
49426420 | 2053 | * Memcg supports userspace OOM handling where failed allocations must |
3812c8c8 JW |
2054 | * sleep on a waitqueue until the userspace task resolves the |
2055 | * situation. Sleeping directly in the charge context with all kinds | |
2056 | * of locks held is not a good idea, instead we remember an OOM state | |
2057 | * in the task and mem_cgroup_oom_synchronize() has to be called at | |
49426420 | 2058 | * the end of the page fault to complete the OOM handling. |
3812c8c8 JW |
2059 | * |
2060 | * Returns %true if an ongoing memcg OOM situation was detected and | |
49426420 | 2061 | * completed, %false otherwise. |
3812c8c8 | 2062 | */ |
49426420 | 2063 | bool mem_cgroup_oom_synchronize(bool handle) |
3812c8c8 | 2064 | { |
49426420 | 2065 | struct mem_cgroup *memcg = current->memcg_oom.memcg; |
3812c8c8 | 2066 | struct oom_wait_info owait; |
49426420 | 2067 | bool locked; |
3812c8c8 JW |
2068 | |
2069 | /* OOM is global, do not handle */ | |
3812c8c8 | 2070 | if (!memcg) |
49426420 | 2071 | return false; |
3812c8c8 | 2072 | |
49426420 JW |
2073 | if (!handle) |
2074 | goto cleanup; | |
3812c8c8 JW |
2075 | |
2076 | owait.memcg = memcg; | |
2077 | owait.wait.flags = 0; | |
2078 | owait.wait.func = memcg_oom_wake_function; | |
2079 | owait.wait.private = current; | |
2080 | INIT_LIST_HEAD(&owait.wait.task_list); | |
867578cb | 2081 | |
3812c8c8 | 2082 | prepare_to_wait(&memcg_oom_waitq, &owait.wait, TASK_KILLABLE); |
49426420 JW |
2083 | mem_cgroup_mark_under_oom(memcg); |
2084 | ||
2085 | locked = mem_cgroup_oom_trylock(memcg); | |
2086 | ||
2087 | if (locked) | |
2088 | mem_cgroup_oom_notify(memcg); | |
2089 | ||
2090 | if (locked && !memcg->oom_kill_disable) { | |
2091 | mem_cgroup_unmark_under_oom(memcg); | |
2092 | finish_wait(&memcg_oom_waitq, &owait.wait); | |
2093 | mem_cgroup_out_of_memory(memcg, current->memcg_oom.gfp_mask, | |
2094 | current->memcg_oom.order); | |
2095 | } else { | |
3812c8c8 | 2096 | schedule(); |
49426420 JW |
2097 | mem_cgroup_unmark_under_oom(memcg); |
2098 | finish_wait(&memcg_oom_waitq, &owait.wait); | |
2099 | } | |
2100 | ||
2101 | if (locked) { | |
fb2a6fc5 JW |
2102 | mem_cgroup_oom_unlock(memcg); |
2103 | /* | |
2104 | * There is no guarantee that an OOM-lock contender | |
2105 | * sees the wakeups triggered by the OOM kill | |
2106 | * uncharges. Wake any sleepers explicitely. | |
2107 | */ | |
2108 | memcg_oom_recover(memcg); | |
2109 | } | |
49426420 JW |
2110 | cleanup: |
2111 | current->memcg_oom.memcg = NULL; | |
3812c8c8 | 2112 | css_put(&memcg->css); |
867578cb | 2113 | return true; |
0b7f569e KH |
2114 | } |
2115 | ||
d7365e78 JW |
2116 | /** |
2117 | * mem_cgroup_begin_page_stat - begin a page state statistics transaction | |
2118 | * @page: page that is going to change accounted state | |
2119 | * @locked: &memcg->move_lock slowpath was taken | |
2120 | * @flags: IRQ-state flags for &memcg->move_lock | |
32047e2a | 2121 | * |
d7365e78 JW |
2122 | * This function must mark the beginning of an accounted page state |
2123 | * change to prevent double accounting when the page is concurrently | |
2124 | * being moved to another memcg: | |
32047e2a | 2125 | * |
d7365e78 JW |
2126 | * memcg = mem_cgroup_begin_page_stat(page, &locked, &flags); |
2127 | * if (TestClearPageState(page)) | |
2128 | * mem_cgroup_update_page_stat(memcg, state, -1); | |
2129 | * mem_cgroup_end_page_stat(memcg, locked, flags); | |
32047e2a | 2130 | * |
d7365e78 JW |
2131 | * The RCU lock is held throughout the transaction. The fast path can |
2132 | * get away without acquiring the memcg->move_lock (@locked is false) | |
2133 | * because page moving starts with an RCU grace period. | |
32047e2a | 2134 | * |
d7365e78 JW |
2135 | * The RCU lock also protects the memcg from being freed when the page |
2136 | * state that is going to change is the only thing preventing the page | |
2137 | * from being uncharged. E.g. end-writeback clearing PageWriteback(), | |
2138 | * which allows migration to go ahead and uncharge the page before the | |
2139 | * account transaction might be complete. | |
d69b042f | 2140 | */ |
d7365e78 JW |
2141 | struct mem_cgroup *mem_cgroup_begin_page_stat(struct page *page, |
2142 | bool *locked, | |
2143 | unsigned long *flags) | |
89c06bd5 KH |
2144 | { |
2145 | struct mem_cgroup *memcg; | |
2146 | struct page_cgroup *pc; | |
2147 | ||
d7365e78 JW |
2148 | rcu_read_lock(); |
2149 | ||
2150 | if (mem_cgroup_disabled()) | |
2151 | return NULL; | |
2152 | ||
89c06bd5 KH |
2153 | pc = lookup_page_cgroup(page); |
2154 | again: | |
2155 | memcg = pc->mem_cgroup; | |
2156 | if (unlikely(!memcg || !PageCgroupUsed(pc))) | |
d7365e78 JW |
2157 | return NULL; |
2158 | ||
2159 | *locked = false; | |
bdcbb659 | 2160 | if (atomic_read(&memcg->moving_account) <= 0) |
d7365e78 | 2161 | return memcg; |
89c06bd5 KH |
2162 | |
2163 | move_lock_mem_cgroup(memcg, flags); | |
2164 | if (memcg != pc->mem_cgroup || !PageCgroupUsed(pc)) { | |
2165 | move_unlock_mem_cgroup(memcg, flags); | |
2166 | goto again; | |
2167 | } | |
2168 | *locked = true; | |
d7365e78 JW |
2169 | |
2170 | return memcg; | |
89c06bd5 KH |
2171 | } |
2172 | ||
d7365e78 JW |
2173 | /** |
2174 | * mem_cgroup_end_page_stat - finish a page state statistics transaction | |
2175 | * @memcg: the memcg that was accounted against | |
2176 | * @locked: value received from mem_cgroup_begin_page_stat() | |
2177 | * @flags: value received from mem_cgroup_begin_page_stat() | |
2178 | */ | |
2179 | void mem_cgroup_end_page_stat(struct mem_cgroup *memcg, bool locked, | |
2180 | unsigned long flags) | |
89c06bd5 | 2181 | { |
d7365e78 JW |
2182 | if (memcg && locked) |
2183 | move_unlock_mem_cgroup(memcg, &flags); | |
89c06bd5 | 2184 | |
d7365e78 | 2185 | rcu_read_unlock(); |
89c06bd5 KH |
2186 | } |
2187 | ||
d7365e78 JW |
2188 | /** |
2189 | * mem_cgroup_update_page_stat - update page state statistics | |
2190 | * @memcg: memcg to account against | |
2191 | * @idx: page state item to account | |
2192 | * @val: number of pages (positive or negative) | |
2193 | * | |
2194 | * See mem_cgroup_begin_page_stat() for locking requirements. | |
2195 | */ | |
2196 | void mem_cgroup_update_page_stat(struct mem_cgroup *memcg, | |
68b4876d | 2197 | enum mem_cgroup_stat_index idx, int val) |
d69b042f | 2198 | { |
658b72c5 | 2199 | VM_BUG_ON(!rcu_read_lock_held()); |
26174efd | 2200 | |
d7365e78 JW |
2201 | if (memcg) |
2202 | this_cpu_add(memcg->stat->count[idx], val); | |
d69b042f | 2203 | } |
26174efd | 2204 | |
cdec2e42 KH |
2205 | /* |
2206 | * size of first charge trial. "32" comes from vmscan.c's magic value. | |
2207 | * TODO: maybe necessary to use big numbers in big irons. | |
2208 | */ | |
7ec99d62 | 2209 | #define CHARGE_BATCH 32U |
cdec2e42 KH |
2210 | struct memcg_stock_pcp { |
2211 | struct mem_cgroup *cached; /* this never be root cgroup */ | |
11c9ea4e | 2212 | unsigned int nr_pages; |
cdec2e42 | 2213 | struct work_struct work; |
26fe6168 | 2214 | unsigned long flags; |
a0db00fc | 2215 | #define FLUSHING_CACHED_CHARGE 0 |
cdec2e42 KH |
2216 | }; |
2217 | static DEFINE_PER_CPU(struct memcg_stock_pcp, memcg_stock); | |
9f50fad6 | 2218 | static DEFINE_MUTEX(percpu_charge_mutex); |
cdec2e42 | 2219 | |
a0956d54 SS |
2220 | /** |
2221 | * consume_stock: Try to consume stocked charge on this cpu. | |
2222 | * @memcg: memcg to consume from. | |
2223 | * @nr_pages: how many pages to charge. | |
2224 | * | |
2225 | * The charges will only happen if @memcg matches the current cpu's memcg | |
2226 | * stock, and at least @nr_pages are available in that stock. Failure to | |
2227 | * service an allocation will refill the stock. | |
2228 | * | |
2229 | * returns true if successful, false otherwise. | |
cdec2e42 | 2230 | */ |
a0956d54 | 2231 | static bool consume_stock(struct mem_cgroup *memcg, unsigned int nr_pages) |
cdec2e42 KH |
2232 | { |
2233 | struct memcg_stock_pcp *stock; | |
3e32cb2e | 2234 | bool ret = false; |
cdec2e42 | 2235 | |
a0956d54 | 2236 | if (nr_pages > CHARGE_BATCH) |
3e32cb2e | 2237 | return ret; |
a0956d54 | 2238 | |
cdec2e42 | 2239 | stock = &get_cpu_var(memcg_stock); |
3e32cb2e | 2240 | if (memcg == stock->cached && stock->nr_pages >= nr_pages) { |
a0956d54 | 2241 | stock->nr_pages -= nr_pages; |
3e32cb2e JW |
2242 | ret = true; |
2243 | } | |
cdec2e42 KH |
2244 | put_cpu_var(memcg_stock); |
2245 | return ret; | |
2246 | } | |
2247 | ||
2248 | /* | |
3e32cb2e | 2249 | * Returns stocks cached in percpu and reset cached information. |
cdec2e42 KH |
2250 | */ |
2251 | static void drain_stock(struct memcg_stock_pcp *stock) | |
2252 | { | |
2253 | struct mem_cgroup *old = stock->cached; | |
2254 | ||
11c9ea4e | 2255 | if (stock->nr_pages) { |
3e32cb2e | 2256 | page_counter_uncharge(&old->memory, stock->nr_pages); |
cdec2e42 | 2257 | if (do_swap_account) |
3e32cb2e | 2258 | page_counter_uncharge(&old->memsw, stock->nr_pages); |
e8ea14cc | 2259 | css_put_many(&old->css, stock->nr_pages); |
11c9ea4e | 2260 | stock->nr_pages = 0; |
cdec2e42 KH |
2261 | } |
2262 | stock->cached = NULL; | |
cdec2e42 KH |
2263 | } |
2264 | ||
2265 | /* | |
2266 | * This must be called under preempt disabled or must be called by | |
2267 | * a thread which is pinned to local cpu. | |
2268 | */ | |
2269 | static void drain_local_stock(struct work_struct *dummy) | |
2270 | { | |
7c8e0181 | 2271 | struct memcg_stock_pcp *stock = this_cpu_ptr(&memcg_stock); |
cdec2e42 | 2272 | drain_stock(stock); |
26fe6168 | 2273 | clear_bit(FLUSHING_CACHED_CHARGE, &stock->flags); |
cdec2e42 KH |
2274 | } |
2275 | ||
e4777496 MH |
2276 | static void __init memcg_stock_init(void) |
2277 | { | |
2278 | int cpu; | |
2279 | ||
2280 | for_each_possible_cpu(cpu) { | |
2281 | struct memcg_stock_pcp *stock = | |
2282 | &per_cpu(memcg_stock, cpu); | |
2283 | INIT_WORK(&stock->work, drain_local_stock); | |
2284 | } | |
2285 | } | |
2286 | ||
cdec2e42 | 2287 | /* |
3e32cb2e | 2288 | * Cache charges(val) to local per_cpu area. |
320cc51d | 2289 | * This will be consumed by consume_stock() function, later. |
cdec2e42 | 2290 | */ |
c0ff4b85 | 2291 | static void refill_stock(struct mem_cgroup *memcg, unsigned int nr_pages) |
cdec2e42 KH |
2292 | { |
2293 | struct memcg_stock_pcp *stock = &get_cpu_var(memcg_stock); | |
2294 | ||
c0ff4b85 | 2295 | if (stock->cached != memcg) { /* reset if necessary */ |
cdec2e42 | 2296 | drain_stock(stock); |
c0ff4b85 | 2297 | stock->cached = memcg; |
cdec2e42 | 2298 | } |
11c9ea4e | 2299 | stock->nr_pages += nr_pages; |
cdec2e42 KH |
2300 | put_cpu_var(memcg_stock); |
2301 | } | |
2302 | ||
2303 | /* | |
c0ff4b85 | 2304 | * Drains all per-CPU charge caches for given root_memcg resp. subtree |
d38144b7 MH |
2305 | * of the hierarchy under it. sync flag says whether we should block |
2306 | * until the work is done. | |
cdec2e42 | 2307 | */ |
c0ff4b85 | 2308 | static void drain_all_stock(struct mem_cgroup *root_memcg, bool sync) |
cdec2e42 | 2309 | { |
26fe6168 | 2310 | int cpu, curcpu; |
d38144b7 | 2311 | |
cdec2e42 | 2312 | /* Notify other cpus that system-wide "drain" is running */ |
cdec2e42 | 2313 | get_online_cpus(); |
5af12d0e | 2314 | curcpu = get_cpu(); |
cdec2e42 KH |
2315 | for_each_online_cpu(cpu) { |
2316 | struct memcg_stock_pcp *stock = &per_cpu(memcg_stock, cpu); | |
c0ff4b85 | 2317 | struct mem_cgroup *memcg; |
26fe6168 | 2318 | |
c0ff4b85 R |
2319 | memcg = stock->cached; |
2320 | if (!memcg || !stock->nr_pages) | |
26fe6168 | 2321 | continue; |
c0ff4b85 | 2322 | if (!mem_cgroup_same_or_subtree(root_memcg, memcg)) |
3e92041d | 2323 | continue; |
d1a05b69 MH |
2324 | if (!test_and_set_bit(FLUSHING_CACHED_CHARGE, &stock->flags)) { |
2325 | if (cpu == curcpu) | |
2326 | drain_local_stock(&stock->work); | |
2327 | else | |
2328 | schedule_work_on(cpu, &stock->work); | |
2329 | } | |
cdec2e42 | 2330 | } |
5af12d0e | 2331 | put_cpu(); |
d38144b7 MH |
2332 | |
2333 | if (!sync) | |
2334 | goto out; | |
2335 | ||
2336 | for_each_online_cpu(cpu) { | |
2337 | struct memcg_stock_pcp *stock = &per_cpu(memcg_stock, cpu); | |
9f50fad6 | 2338 | if (test_bit(FLUSHING_CACHED_CHARGE, &stock->flags)) |
d38144b7 MH |
2339 | flush_work(&stock->work); |
2340 | } | |
2341 | out: | |
f894ffa8 | 2342 | put_online_cpus(); |
d38144b7 MH |
2343 | } |
2344 | ||
2345 | /* | |
2346 | * Tries to drain stocked charges in other cpus. This function is asynchronous | |
2347 | * and just put a work per cpu for draining localy on each cpu. Caller can | |
3e32cb2e | 2348 | * expects some charges will be back later but cannot wait for it. |
d38144b7 | 2349 | */ |
c0ff4b85 | 2350 | static void drain_all_stock_async(struct mem_cgroup *root_memcg) |
d38144b7 | 2351 | { |
9f50fad6 MH |
2352 | /* |
2353 | * If someone calls draining, avoid adding more kworker runs. | |
2354 | */ | |
2355 | if (!mutex_trylock(&percpu_charge_mutex)) | |
2356 | return; | |
c0ff4b85 | 2357 | drain_all_stock(root_memcg, false); |
9f50fad6 | 2358 | mutex_unlock(&percpu_charge_mutex); |
cdec2e42 KH |
2359 | } |
2360 | ||
2361 | /* This is a synchronous drain interface. */ | |
c0ff4b85 | 2362 | static void drain_all_stock_sync(struct mem_cgroup *root_memcg) |
cdec2e42 KH |
2363 | { |
2364 | /* called when force_empty is called */ | |
9f50fad6 | 2365 | mutex_lock(&percpu_charge_mutex); |
c0ff4b85 | 2366 | drain_all_stock(root_memcg, true); |
9f50fad6 | 2367 | mutex_unlock(&percpu_charge_mutex); |
cdec2e42 KH |
2368 | } |
2369 | ||
711d3d2c KH |
2370 | /* |
2371 | * This function drains percpu counter value from DEAD cpu and | |
2372 | * move it to local cpu. Note that this function can be preempted. | |
2373 | */ | |
c0ff4b85 | 2374 | static void mem_cgroup_drain_pcp_counter(struct mem_cgroup *memcg, int cpu) |
711d3d2c KH |
2375 | { |
2376 | int i; | |
2377 | ||
c0ff4b85 | 2378 | spin_lock(&memcg->pcp_counter_lock); |
6104621d | 2379 | for (i = 0; i < MEM_CGROUP_STAT_NSTATS; i++) { |
c0ff4b85 | 2380 | long x = per_cpu(memcg->stat->count[i], cpu); |
711d3d2c | 2381 | |
c0ff4b85 R |
2382 | per_cpu(memcg->stat->count[i], cpu) = 0; |
2383 | memcg->nocpu_base.count[i] += x; | |
711d3d2c | 2384 | } |
e9f8974f | 2385 | for (i = 0; i < MEM_CGROUP_EVENTS_NSTATS; i++) { |
c0ff4b85 | 2386 | unsigned long x = per_cpu(memcg->stat->events[i], cpu); |
e9f8974f | 2387 | |
c0ff4b85 R |
2388 | per_cpu(memcg->stat->events[i], cpu) = 0; |
2389 | memcg->nocpu_base.events[i] += x; | |
e9f8974f | 2390 | } |
c0ff4b85 | 2391 | spin_unlock(&memcg->pcp_counter_lock); |
711d3d2c KH |
2392 | } |
2393 | ||
0db0628d | 2394 | static int memcg_cpu_hotplug_callback(struct notifier_block *nb, |
cdec2e42 KH |
2395 | unsigned long action, |
2396 | void *hcpu) | |
2397 | { | |
2398 | int cpu = (unsigned long)hcpu; | |
2399 | struct memcg_stock_pcp *stock; | |
711d3d2c | 2400 | struct mem_cgroup *iter; |
cdec2e42 | 2401 | |
619d094b | 2402 | if (action == CPU_ONLINE) |
1489ebad | 2403 | return NOTIFY_OK; |
1489ebad | 2404 | |
d833049b | 2405 | if (action != CPU_DEAD && action != CPU_DEAD_FROZEN) |
cdec2e42 | 2406 | return NOTIFY_OK; |
711d3d2c | 2407 | |
9f3a0d09 | 2408 | for_each_mem_cgroup(iter) |
711d3d2c KH |
2409 | mem_cgroup_drain_pcp_counter(iter, cpu); |
2410 | ||
cdec2e42 KH |
2411 | stock = &per_cpu(memcg_stock, cpu); |
2412 | drain_stock(stock); | |
2413 | return NOTIFY_OK; | |
2414 | } | |
2415 | ||
00501b53 JW |
2416 | static int try_charge(struct mem_cgroup *memcg, gfp_t gfp_mask, |
2417 | unsigned int nr_pages) | |
8a9f3ccd | 2418 | { |
7ec99d62 | 2419 | unsigned int batch = max(CHARGE_BATCH, nr_pages); |
9b130619 | 2420 | int nr_retries = MEM_CGROUP_RECLAIM_RETRIES; |
6539cc05 | 2421 | struct mem_cgroup *mem_over_limit; |
3e32cb2e | 2422 | struct page_counter *counter; |
6539cc05 | 2423 | unsigned long nr_reclaimed; |
b70a2a21 JW |
2424 | bool may_swap = true; |
2425 | bool drained = false; | |
05b84301 | 2426 | int ret = 0; |
a636b327 | 2427 | |
ce00a967 JW |
2428 | if (mem_cgroup_is_root(memcg)) |
2429 | goto done; | |
6539cc05 | 2430 | retry: |
b6b6cc72 MH |
2431 | if (consume_stock(memcg, nr_pages)) |
2432 | goto done; | |
8a9f3ccd | 2433 | |
3fbe7244 | 2434 | if (!do_swap_account || |
3e32cb2e JW |
2435 | !page_counter_try_charge(&memcg->memsw, batch, &counter)) { |
2436 | if (!page_counter_try_charge(&memcg->memory, batch, &counter)) | |
6539cc05 | 2437 | goto done_restock; |
3fbe7244 | 2438 | if (do_swap_account) |
3e32cb2e JW |
2439 | page_counter_uncharge(&memcg->memsw, batch); |
2440 | mem_over_limit = mem_cgroup_from_counter(counter, memory); | |
3fbe7244 | 2441 | } else { |
3e32cb2e | 2442 | mem_over_limit = mem_cgroup_from_counter(counter, memsw); |
b70a2a21 | 2443 | may_swap = false; |
3fbe7244 | 2444 | } |
7a81b88c | 2445 | |
6539cc05 JW |
2446 | if (batch > nr_pages) { |
2447 | batch = nr_pages; | |
2448 | goto retry; | |
2449 | } | |
6d61ef40 | 2450 | |
06b078fc JW |
2451 | /* |
2452 | * Unlike in global OOM situations, memcg is not in a physical | |
2453 | * memory shortage. Allow dying and OOM-killed tasks to | |
2454 | * bypass the last charges so that they can exit quickly and | |
2455 | * free their memory. | |
2456 | */ | |
2457 | if (unlikely(test_thread_flag(TIF_MEMDIE) || | |
2458 | fatal_signal_pending(current) || | |
2459 | current->flags & PF_EXITING)) | |
2460 | goto bypass; | |
2461 | ||
2462 | if (unlikely(task_in_memcg_oom(current))) | |
2463 | goto nomem; | |
2464 | ||
6539cc05 JW |
2465 | if (!(gfp_mask & __GFP_WAIT)) |
2466 | goto nomem; | |
4b534334 | 2467 | |
b70a2a21 JW |
2468 | nr_reclaimed = try_to_free_mem_cgroup_pages(mem_over_limit, nr_pages, |
2469 | gfp_mask, may_swap); | |
6539cc05 | 2470 | |
61e02c74 | 2471 | if (mem_cgroup_margin(mem_over_limit) >= nr_pages) |
6539cc05 | 2472 | goto retry; |
28c34c29 | 2473 | |
b70a2a21 JW |
2474 | if (!drained) { |
2475 | drain_all_stock_async(mem_over_limit); | |
2476 | drained = true; | |
2477 | goto retry; | |
2478 | } | |
2479 | ||
28c34c29 JW |
2480 | if (gfp_mask & __GFP_NORETRY) |
2481 | goto nomem; | |
6539cc05 JW |
2482 | /* |
2483 | * Even though the limit is exceeded at this point, reclaim | |
2484 | * may have been able to free some pages. Retry the charge | |
2485 | * before killing the task. | |
2486 | * | |
2487 | * Only for regular pages, though: huge pages are rather | |
2488 | * unlikely to succeed so close to the limit, and we fall back | |
2489 | * to regular pages anyway in case of failure. | |
2490 | */ | |
61e02c74 | 2491 | if (nr_reclaimed && nr_pages <= (1 << PAGE_ALLOC_COSTLY_ORDER)) |
6539cc05 JW |
2492 | goto retry; |
2493 | /* | |
2494 | * At task move, charge accounts can be doubly counted. So, it's | |
2495 | * better to wait until the end of task_move if something is going on. | |
2496 | */ | |
2497 | if (mem_cgroup_wait_acct_move(mem_over_limit)) | |
2498 | goto retry; | |
2499 | ||
9b130619 JW |
2500 | if (nr_retries--) |
2501 | goto retry; | |
2502 | ||
06b078fc JW |
2503 | if (gfp_mask & __GFP_NOFAIL) |
2504 | goto bypass; | |
2505 | ||
6539cc05 JW |
2506 | if (fatal_signal_pending(current)) |
2507 | goto bypass; | |
2508 | ||
61e02c74 | 2509 | mem_cgroup_oom(mem_over_limit, gfp_mask, get_order(nr_pages)); |
7a81b88c | 2510 | nomem: |
6d1fdc48 | 2511 | if (!(gfp_mask & __GFP_NOFAIL)) |
3168ecbe | 2512 | return -ENOMEM; |
867578cb | 2513 | bypass: |
ce00a967 | 2514 | return -EINTR; |
6539cc05 JW |
2515 | |
2516 | done_restock: | |
e8ea14cc | 2517 | css_get_many(&memcg->css, batch); |
6539cc05 JW |
2518 | if (batch > nr_pages) |
2519 | refill_stock(memcg, batch - nr_pages); | |
2520 | done: | |
05b84301 | 2521 | return ret; |
7a81b88c | 2522 | } |
8a9f3ccd | 2523 | |
00501b53 | 2524 | static void cancel_charge(struct mem_cgroup *memcg, unsigned int nr_pages) |
a3032a2c | 2525 | { |
ce00a967 JW |
2526 | if (mem_cgroup_is_root(memcg)) |
2527 | return; | |
2528 | ||
3e32cb2e | 2529 | page_counter_uncharge(&memcg->memory, nr_pages); |
05b84301 | 2530 | if (do_swap_account) |
3e32cb2e | 2531 | page_counter_uncharge(&memcg->memsw, nr_pages); |
e8ea14cc JW |
2532 | |
2533 | css_put_many(&memcg->css, nr_pages); | |
d01dd17f KH |
2534 | } |
2535 | ||
a3b2d692 KH |
2536 | /* |
2537 | * A helper function to get mem_cgroup from ID. must be called under | |
ec903c0c TH |
2538 | * rcu_read_lock(). The caller is responsible for calling |
2539 | * css_tryget_online() if the mem_cgroup is used for charging. (dropping | |
2540 | * refcnt from swap can be called against removed memcg.) | |
a3b2d692 KH |
2541 | */ |
2542 | static struct mem_cgroup *mem_cgroup_lookup(unsigned short id) | |
2543 | { | |
a3b2d692 KH |
2544 | /* ID 0 is unused ID */ |
2545 | if (!id) | |
2546 | return NULL; | |
34c00c31 | 2547 | return mem_cgroup_from_id(id); |
a3b2d692 KH |
2548 | } |
2549 | ||
0a31bc97 JW |
2550 | /* |
2551 | * try_get_mem_cgroup_from_page - look up page's memcg association | |
2552 | * @page: the page | |
2553 | * | |
2554 | * Look up, get a css reference, and return the memcg that owns @page. | |
2555 | * | |
2556 | * The page must be locked to prevent racing with swap-in and page | |
2557 | * cache charges. If coming from an unlocked page table, the caller | |
2558 | * must ensure the page is on the LRU or this can race with charging. | |
2559 | */ | |
e42d9d5d | 2560 | struct mem_cgroup *try_get_mem_cgroup_from_page(struct page *page) |
b5a84319 | 2561 | { |
c0ff4b85 | 2562 | struct mem_cgroup *memcg = NULL; |
3c776e64 | 2563 | struct page_cgroup *pc; |
a3b2d692 | 2564 | unsigned short id; |
b5a84319 KH |
2565 | swp_entry_t ent; |
2566 | ||
309381fe | 2567 | VM_BUG_ON_PAGE(!PageLocked(page), page); |
3c776e64 | 2568 | |
3c776e64 | 2569 | pc = lookup_page_cgroup(page); |
a3b2d692 | 2570 | if (PageCgroupUsed(pc)) { |
c0ff4b85 | 2571 | memcg = pc->mem_cgroup; |
ec903c0c | 2572 | if (memcg && !css_tryget_online(&memcg->css)) |
c0ff4b85 | 2573 | memcg = NULL; |
e42d9d5d | 2574 | } else if (PageSwapCache(page)) { |
3c776e64 | 2575 | ent.val = page_private(page); |
9fb4b7cc | 2576 | id = lookup_swap_cgroup_id(ent); |
a3b2d692 | 2577 | rcu_read_lock(); |
c0ff4b85 | 2578 | memcg = mem_cgroup_lookup(id); |
ec903c0c | 2579 | if (memcg && !css_tryget_online(&memcg->css)) |
c0ff4b85 | 2580 | memcg = NULL; |
a3b2d692 | 2581 | rcu_read_unlock(); |
3c776e64 | 2582 | } |
c0ff4b85 | 2583 | return memcg; |
b5a84319 KH |
2584 | } |
2585 | ||
0a31bc97 JW |
2586 | static void lock_page_lru(struct page *page, int *isolated) |
2587 | { | |
2588 | struct zone *zone = page_zone(page); | |
2589 | ||
2590 | spin_lock_irq(&zone->lru_lock); | |
2591 | if (PageLRU(page)) { | |
2592 | struct lruvec *lruvec; | |
2593 | ||
2594 | lruvec = mem_cgroup_page_lruvec(page, zone); | |
2595 | ClearPageLRU(page); | |
2596 | del_page_from_lru_list(page, lruvec, page_lru(page)); | |
2597 | *isolated = 1; | |
2598 | } else | |
2599 | *isolated = 0; | |
2600 | } | |
2601 | ||
2602 | static void unlock_page_lru(struct page *page, int isolated) | |
2603 | { | |
2604 | struct zone *zone = page_zone(page); | |
2605 | ||
2606 | if (isolated) { | |
2607 | struct lruvec *lruvec; | |
2608 | ||
2609 | lruvec = mem_cgroup_page_lruvec(page, zone); | |
2610 | VM_BUG_ON_PAGE(PageLRU(page), page); | |
2611 | SetPageLRU(page); | |
2612 | add_page_to_lru_list(page, lruvec, page_lru(page)); | |
2613 | } | |
2614 | spin_unlock_irq(&zone->lru_lock); | |
2615 | } | |
2616 | ||
00501b53 | 2617 | static void commit_charge(struct page *page, struct mem_cgroup *memcg, |
6abb5a86 | 2618 | bool lrucare) |
7a81b88c | 2619 | { |
ce587e65 | 2620 | struct page_cgroup *pc = lookup_page_cgroup(page); |
0a31bc97 | 2621 | int isolated; |
9ce70c02 | 2622 | |
309381fe | 2623 | VM_BUG_ON_PAGE(PageCgroupUsed(pc), page); |
ca3e0214 KH |
2624 | /* |
2625 | * we don't need page_cgroup_lock about tail pages, becase they are not | |
2626 | * accessed by any other context at this point. | |
2627 | */ | |
9ce70c02 HD |
2628 | |
2629 | /* | |
2630 | * In some cases, SwapCache and FUSE(splice_buf->radixtree), the page | |
2631 | * may already be on some other mem_cgroup's LRU. Take care of it. | |
2632 | */ | |
0a31bc97 JW |
2633 | if (lrucare) |
2634 | lock_page_lru(page, &isolated); | |
9ce70c02 | 2635 | |
0a31bc97 JW |
2636 | /* |
2637 | * Nobody should be changing or seriously looking at | |
2638 | * pc->mem_cgroup and pc->flags at this point: | |
2639 | * | |
2640 | * - the page is uncharged | |
2641 | * | |
2642 | * - the page is off-LRU | |
2643 | * | |
2644 | * - an anonymous fault has exclusive page access, except for | |
2645 | * a locked page table | |
2646 | * | |
2647 | * - a page cache insertion, a swapin fault, or a migration | |
2648 | * have the page locked | |
2649 | */ | |
c0ff4b85 | 2650 | pc->mem_cgroup = memcg; |
0a31bc97 | 2651 | pc->flags = PCG_USED | PCG_MEM | (do_swap_account ? PCG_MEMSW : 0); |
9ce70c02 | 2652 | |
0a31bc97 JW |
2653 | if (lrucare) |
2654 | unlock_page_lru(page, isolated); | |
7a81b88c | 2655 | } |
66e1707b | 2656 | |
7ae1e1d0 | 2657 | #ifdef CONFIG_MEMCG_KMEM |
bd673145 VD |
2658 | /* |
2659 | * The memcg_slab_mutex is held whenever a per memcg kmem cache is created or | |
2660 | * destroyed. It protects memcg_caches arrays and memcg_slab_caches lists. | |
2661 | */ | |
2662 | static DEFINE_MUTEX(memcg_slab_mutex); | |
2663 | ||
d6441637 VD |
2664 | static DEFINE_MUTEX(activate_kmem_mutex); |
2665 | ||
1f458cbf GC |
2666 | /* |
2667 | * This is a bit cumbersome, but it is rarely used and avoids a backpointer | |
2668 | * in the memcg_cache_params struct. | |
2669 | */ | |
2670 | static struct kmem_cache *memcg_params_to_cache(struct memcg_cache_params *p) | |
2671 | { | |
2672 | struct kmem_cache *cachep; | |
2673 | ||
2674 | VM_BUG_ON(p->is_root_cache); | |
2675 | cachep = p->root_cache; | |
7a67d7ab | 2676 | return cache_from_memcg_idx(cachep, memcg_cache_id(p->memcg)); |
1f458cbf GC |
2677 | } |
2678 | ||
749c5415 | 2679 | #ifdef CONFIG_SLABINFO |
2da8ca82 | 2680 | static int mem_cgroup_slabinfo_read(struct seq_file *m, void *v) |
749c5415 | 2681 | { |
2da8ca82 | 2682 | struct mem_cgroup *memcg = mem_cgroup_from_css(seq_css(m)); |
749c5415 GC |
2683 | struct memcg_cache_params *params; |
2684 | ||
cf2b8fbf | 2685 | if (!memcg_kmem_is_active(memcg)) |
749c5415 GC |
2686 | return -EIO; |
2687 | ||
2688 | print_slabinfo_header(m); | |
2689 | ||
bd673145 | 2690 | mutex_lock(&memcg_slab_mutex); |
749c5415 GC |
2691 | list_for_each_entry(params, &memcg->memcg_slab_caches, list) |
2692 | cache_show(memcg_params_to_cache(params), m); | |
bd673145 | 2693 | mutex_unlock(&memcg_slab_mutex); |
749c5415 GC |
2694 | |
2695 | return 0; | |
2696 | } | |
2697 | #endif | |
2698 | ||
3e32cb2e JW |
2699 | static int memcg_charge_kmem(struct mem_cgroup *memcg, gfp_t gfp, |
2700 | unsigned long nr_pages) | |
7ae1e1d0 | 2701 | { |
3e32cb2e | 2702 | struct page_counter *counter; |
7ae1e1d0 | 2703 | int ret = 0; |
7ae1e1d0 | 2704 | |
3e32cb2e JW |
2705 | ret = page_counter_try_charge(&memcg->kmem, nr_pages, &counter); |
2706 | if (ret < 0) | |
7ae1e1d0 GC |
2707 | return ret; |
2708 | ||
3e32cb2e | 2709 | ret = try_charge(memcg, gfp, nr_pages); |
7ae1e1d0 GC |
2710 | if (ret == -EINTR) { |
2711 | /* | |
00501b53 JW |
2712 | * try_charge() chose to bypass to root due to OOM kill or |
2713 | * fatal signal. Since our only options are to either fail | |
2714 | * the allocation or charge it to this cgroup, do it as a | |
2715 | * temporary condition. But we can't fail. From a kmem/slab | |
2716 | * perspective, the cache has already been selected, by | |
2717 | * mem_cgroup_kmem_get_cache(), so it is too late to change | |
7ae1e1d0 GC |
2718 | * our minds. |
2719 | * | |
2720 | * This condition will only trigger if the task entered | |
00501b53 JW |
2721 | * memcg_charge_kmem in a sane state, but was OOM-killed |
2722 | * during try_charge() above. Tasks that were already dying | |
2723 | * when the allocation triggers should have been already | |
7ae1e1d0 GC |
2724 | * directed to the root cgroup in memcontrol.h |
2725 | */ | |
3e32cb2e | 2726 | page_counter_charge(&memcg->memory, nr_pages); |
7ae1e1d0 | 2727 | if (do_swap_account) |
3e32cb2e | 2728 | page_counter_charge(&memcg->memsw, nr_pages); |
e8ea14cc | 2729 | css_get_many(&memcg->css, nr_pages); |
7ae1e1d0 GC |
2730 | ret = 0; |
2731 | } else if (ret) | |
3e32cb2e | 2732 | page_counter_uncharge(&memcg->kmem, nr_pages); |
7ae1e1d0 GC |
2733 | |
2734 | return ret; | |
2735 | } | |
2736 | ||
3e32cb2e JW |
2737 | static void memcg_uncharge_kmem(struct mem_cgroup *memcg, |
2738 | unsigned long nr_pages) | |
7ae1e1d0 | 2739 | { |
3e32cb2e | 2740 | page_counter_uncharge(&memcg->memory, nr_pages); |
7ae1e1d0 | 2741 | if (do_swap_account) |
3e32cb2e | 2742 | page_counter_uncharge(&memcg->memsw, nr_pages); |
7de37682 | 2743 | |
64f21993 | 2744 | page_counter_uncharge(&memcg->kmem, nr_pages); |
e8ea14cc JW |
2745 | |
2746 | css_put_many(&memcg->css, nr_pages); | |
7ae1e1d0 GC |
2747 | } |
2748 | ||
2633d7a0 GC |
2749 | /* |
2750 | * helper for acessing a memcg's index. It will be used as an index in the | |
2751 | * child cache array in kmem_cache, and also to derive its name. This function | |
2752 | * will return -1 when this is not a kmem-limited memcg. | |
2753 | */ | |
2754 | int memcg_cache_id(struct mem_cgroup *memcg) | |
2755 | { | |
2756 | return memcg ? memcg->kmemcg_id : -1; | |
2757 | } | |
2758 | ||
f3bb3043 | 2759 | static int memcg_alloc_cache_id(void) |
55007d84 | 2760 | { |
f3bb3043 VD |
2761 | int id, size; |
2762 | int err; | |
2763 | ||
2764 | id = ida_simple_get(&kmem_limited_groups, | |
2765 | 0, MEMCG_CACHES_MAX_SIZE, GFP_KERNEL); | |
2766 | if (id < 0) | |
2767 | return id; | |
55007d84 | 2768 | |
f3bb3043 VD |
2769 | if (id < memcg_limited_groups_array_size) |
2770 | return id; | |
2771 | ||
2772 | /* | |
2773 | * There's no space for the new id in memcg_caches arrays, | |
2774 | * so we have to grow them. | |
2775 | */ | |
2776 | ||
2777 | size = 2 * (id + 1); | |
55007d84 GC |
2778 | if (size < MEMCG_CACHES_MIN_SIZE) |
2779 | size = MEMCG_CACHES_MIN_SIZE; | |
2780 | else if (size > MEMCG_CACHES_MAX_SIZE) | |
2781 | size = MEMCG_CACHES_MAX_SIZE; | |
2782 | ||
f3bb3043 VD |
2783 | mutex_lock(&memcg_slab_mutex); |
2784 | err = memcg_update_all_caches(size); | |
2785 | mutex_unlock(&memcg_slab_mutex); | |
2786 | ||
2787 | if (err) { | |
2788 | ida_simple_remove(&kmem_limited_groups, id); | |
2789 | return err; | |
2790 | } | |
2791 | return id; | |
2792 | } | |
2793 | ||
2794 | static void memcg_free_cache_id(int id) | |
2795 | { | |
2796 | ida_simple_remove(&kmem_limited_groups, id); | |
55007d84 GC |
2797 | } |
2798 | ||
2799 | /* | |
2800 | * We should update the current array size iff all caches updates succeed. This | |
2801 | * can only be done from the slab side. The slab mutex needs to be held when | |
2802 | * calling this. | |
2803 | */ | |
2804 | void memcg_update_array_size(int num) | |
2805 | { | |
f3bb3043 | 2806 | memcg_limited_groups_array_size = num; |
55007d84 GC |
2807 | } |
2808 | ||
776ed0f0 VD |
2809 | static void memcg_register_cache(struct mem_cgroup *memcg, |
2810 | struct kmem_cache *root_cache) | |
2633d7a0 | 2811 | { |
93f39eea VD |
2812 | static char memcg_name_buf[NAME_MAX + 1]; /* protected by |
2813 | memcg_slab_mutex */ | |
bd673145 | 2814 | struct kmem_cache *cachep; |
d7f25f8a GC |
2815 | int id; |
2816 | ||
bd673145 VD |
2817 | lockdep_assert_held(&memcg_slab_mutex); |
2818 | ||
2819 | id = memcg_cache_id(memcg); | |
2820 | ||
2821 | /* | |
2822 | * Since per-memcg caches are created asynchronously on first | |
2823 | * allocation (see memcg_kmem_get_cache()), several threads can try to | |
2824 | * create the same cache, but only one of them may succeed. | |
2825 | */ | |
2826 | if (cache_from_memcg_idx(root_cache, id)) | |
1aa13254 VD |
2827 | return; |
2828 | ||
073ee1c6 | 2829 | cgroup_name(memcg->css.cgroup, memcg_name_buf, NAME_MAX + 1); |
776ed0f0 | 2830 | cachep = memcg_create_kmem_cache(memcg, root_cache, memcg_name_buf); |
2edefe11 | 2831 | /* |
bd673145 VD |
2832 | * If we could not create a memcg cache, do not complain, because |
2833 | * that's not critical at all as we can always proceed with the root | |
2834 | * cache. | |
2edefe11 | 2835 | */ |
bd673145 VD |
2836 | if (!cachep) |
2837 | return; | |
2edefe11 | 2838 | |
33a690c4 | 2839 | css_get(&memcg->css); |
bd673145 | 2840 | list_add(&cachep->memcg_params->list, &memcg->memcg_slab_caches); |
1aa13254 | 2841 | |
d7f25f8a | 2842 | /* |
959c8963 VD |
2843 | * Since readers won't lock (see cache_from_memcg_idx()), we need a |
2844 | * barrier here to ensure nobody will see the kmem_cache partially | |
2845 | * initialized. | |
d7f25f8a | 2846 | */ |
959c8963 VD |
2847 | smp_wmb(); |
2848 | ||
bd673145 VD |
2849 | BUG_ON(root_cache->memcg_params->memcg_caches[id]); |
2850 | root_cache->memcg_params->memcg_caches[id] = cachep; | |
1aa13254 | 2851 | } |
d7f25f8a | 2852 | |
776ed0f0 | 2853 | static void memcg_unregister_cache(struct kmem_cache *cachep) |
1aa13254 | 2854 | { |
bd673145 | 2855 | struct kmem_cache *root_cache; |
1aa13254 VD |
2856 | struct mem_cgroup *memcg; |
2857 | int id; | |
2858 | ||
bd673145 | 2859 | lockdep_assert_held(&memcg_slab_mutex); |
d7f25f8a | 2860 | |
bd673145 | 2861 | BUG_ON(is_root_cache(cachep)); |
2edefe11 | 2862 | |
bd673145 VD |
2863 | root_cache = cachep->memcg_params->root_cache; |
2864 | memcg = cachep->memcg_params->memcg; | |
96403da2 | 2865 | id = memcg_cache_id(memcg); |
d7f25f8a | 2866 | |
bd673145 VD |
2867 | BUG_ON(root_cache->memcg_params->memcg_caches[id] != cachep); |
2868 | root_cache->memcg_params->memcg_caches[id] = NULL; | |
d7f25f8a | 2869 | |
bd673145 VD |
2870 | list_del(&cachep->memcg_params->list); |
2871 | ||
2872 | kmem_cache_destroy(cachep); | |
33a690c4 VD |
2873 | |
2874 | /* drop the reference taken in memcg_register_cache */ | |
2875 | css_put(&memcg->css); | |
2633d7a0 GC |
2876 | } |
2877 | ||
0e9d92f2 GC |
2878 | /* |
2879 | * During the creation a new cache, we need to disable our accounting mechanism | |
2880 | * altogether. This is true even if we are not creating, but rather just | |
2881 | * enqueing new caches to be created. | |
2882 | * | |
2883 | * This is because that process will trigger allocations; some visible, like | |
2884 | * explicit kmallocs to auxiliary data structures, name strings and internal | |
2885 | * cache structures; some well concealed, like INIT_WORK() that can allocate | |
2886 | * objects during debug. | |
2887 | * | |
2888 | * If any allocation happens during memcg_kmem_get_cache, we will recurse back | |
2889 | * to it. This may not be a bounded recursion: since the first cache creation | |
2890 | * failed to complete (waiting on the allocation), we'll just try to create the | |
2891 | * cache again, failing at the same point. | |
2892 | * | |
2893 | * memcg_kmem_get_cache is prepared to abort after seeing a positive count of | |
2894 | * memcg_kmem_skip_account. So we enclose anything that might allocate memory | |
2895 | * inside the following two functions. | |
2896 | */ | |
2897 | static inline void memcg_stop_kmem_account(void) | |
2898 | { | |
2899 | VM_BUG_ON(!current->mm); | |
2900 | current->memcg_kmem_skip_account++; | |
2901 | } | |
2902 | ||
2903 | static inline void memcg_resume_kmem_account(void) | |
2904 | { | |
2905 | VM_BUG_ON(!current->mm); | |
2906 | current->memcg_kmem_skip_account--; | |
2907 | } | |
2908 | ||
776ed0f0 | 2909 | int __memcg_cleanup_cache_params(struct kmem_cache *s) |
7cf27982 GC |
2910 | { |
2911 | struct kmem_cache *c; | |
b8529907 | 2912 | int i, failed = 0; |
7cf27982 | 2913 | |
bd673145 | 2914 | mutex_lock(&memcg_slab_mutex); |
7a67d7ab QH |
2915 | for_each_memcg_cache_index(i) { |
2916 | c = cache_from_memcg_idx(s, i); | |
7cf27982 GC |
2917 | if (!c) |
2918 | continue; | |
2919 | ||
776ed0f0 | 2920 | memcg_unregister_cache(c); |
b8529907 VD |
2921 | |
2922 | if (cache_from_memcg_idx(s, i)) | |
2923 | failed++; | |
7cf27982 | 2924 | } |
bd673145 | 2925 | mutex_unlock(&memcg_slab_mutex); |
b8529907 | 2926 | return failed; |
7cf27982 GC |
2927 | } |
2928 | ||
776ed0f0 | 2929 | static void memcg_unregister_all_caches(struct mem_cgroup *memcg) |
1f458cbf GC |
2930 | { |
2931 | struct kmem_cache *cachep; | |
bd673145 | 2932 | struct memcg_cache_params *params, *tmp; |
1f458cbf GC |
2933 | |
2934 | if (!memcg_kmem_is_active(memcg)) | |
2935 | return; | |
2936 | ||
bd673145 VD |
2937 | mutex_lock(&memcg_slab_mutex); |
2938 | list_for_each_entry_safe(params, tmp, &memcg->memcg_slab_caches, list) { | |
1f458cbf | 2939 | cachep = memcg_params_to_cache(params); |
bd673145 VD |
2940 | kmem_cache_shrink(cachep); |
2941 | if (atomic_read(&cachep->memcg_params->nr_pages) == 0) | |
776ed0f0 | 2942 | memcg_unregister_cache(cachep); |
1f458cbf | 2943 | } |
bd673145 | 2944 | mutex_unlock(&memcg_slab_mutex); |
1f458cbf GC |
2945 | } |
2946 | ||
776ed0f0 | 2947 | struct memcg_register_cache_work { |
5722d094 VD |
2948 | struct mem_cgroup *memcg; |
2949 | struct kmem_cache *cachep; | |
2950 | struct work_struct work; | |
2951 | }; | |
2952 | ||
776ed0f0 | 2953 | static void memcg_register_cache_func(struct work_struct *w) |
d7f25f8a | 2954 | { |
776ed0f0 VD |
2955 | struct memcg_register_cache_work *cw = |
2956 | container_of(w, struct memcg_register_cache_work, work); | |
5722d094 VD |
2957 | struct mem_cgroup *memcg = cw->memcg; |
2958 | struct kmem_cache *cachep = cw->cachep; | |
d7f25f8a | 2959 | |
bd673145 | 2960 | mutex_lock(&memcg_slab_mutex); |
776ed0f0 | 2961 | memcg_register_cache(memcg, cachep); |
bd673145 VD |
2962 | mutex_unlock(&memcg_slab_mutex); |
2963 | ||
5722d094 | 2964 | css_put(&memcg->css); |
d7f25f8a GC |
2965 | kfree(cw); |
2966 | } | |
2967 | ||
2968 | /* | |
2969 | * Enqueue the creation of a per-memcg kmem_cache. | |
d7f25f8a | 2970 | */ |
776ed0f0 VD |
2971 | static void __memcg_schedule_register_cache(struct mem_cgroup *memcg, |
2972 | struct kmem_cache *cachep) | |
d7f25f8a | 2973 | { |
776ed0f0 | 2974 | struct memcg_register_cache_work *cw; |
d7f25f8a | 2975 | |
776ed0f0 | 2976 | cw = kmalloc(sizeof(*cw), GFP_NOWAIT); |
ca0dde97 LZ |
2977 | if (cw == NULL) { |
2978 | css_put(&memcg->css); | |
d7f25f8a GC |
2979 | return; |
2980 | } | |
2981 | ||
2982 | cw->memcg = memcg; | |
2983 | cw->cachep = cachep; | |
2984 | ||
776ed0f0 | 2985 | INIT_WORK(&cw->work, memcg_register_cache_func); |
d7f25f8a GC |
2986 | schedule_work(&cw->work); |
2987 | } | |
2988 | ||
776ed0f0 VD |
2989 | static void memcg_schedule_register_cache(struct mem_cgroup *memcg, |
2990 | struct kmem_cache *cachep) | |
0e9d92f2 GC |
2991 | { |
2992 | /* | |
2993 | * We need to stop accounting when we kmalloc, because if the | |
2994 | * corresponding kmalloc cache is not yet created, the first allocation | |
776ed0f0 | 2995 | * in __memcg_schedule_register_cache will recurse. |
0e9d92f2 GC |
2996 | * |
2997 | * However, it is better to enclose the whole function. Depending on | |
2998 | * the debugging options enabled, INIT_WORK(), for instance, can | |
2999 | * trigger an allocation. This too, will make us recurse. Because at | |
3000 | * this point we can't allow ourselves back into memcg_kmem_get_cache, | |
3001 | * the safest choice is to do it like this, wrapping the whole function. | |
3002 | */ | |
3003 | memcg_stop_kmem_account(); | |
776ed0f0 | 3004 | __memcg_schedule_register_cache(memcg, cachep); |
0e9d92f2 GC |
3005 | memcg_resume_kmem_account(); |
3006 | } | |
c67a8a68 VD |
3007 | |
3008 | int __memcg_charge_slab(struct kmem_cache *cachep, gfp_t gfp, int order) | |
3009 | { | |
3e32cb2e | 3010 | unsigned int nr_pages = 1 << order; |
c67a8a68 VD |
3011 | int res; |
3012 | ||
3e32cb2e | 3013 | res = memcg_charge_kmem(cachep->memcg_params->memcg, gfp, nr_pages); |
c67a8a68 | 3014 | if (!res) |
3e32cb2e | 3015 | atomic_add(nr_pages, &cachep->memcg_params->nr_pages); |
c67a8a68 VD |
3016 | return res; |
3017 | } | |
3018 | ||
3019 | void __memcg_uncharge_slab(struct kmem_cache *cachep, int order) | |
3020 | { | |
3e32cb2e JW |
3021 | unsigned int nr_pages = 1 << order; |
3022 | ||
3023 | memcg_uncharge_kmem(cachep->memcg_params->memcg, nr_pages); | |
3024 | atomic_sub(nr_pages, &cachep->memcg_params->nr_pages); | |
c67a8a68 VD |
3025 | } |
3026 | ||
d7f25f8a GC |
3027 | /* |
3028 | * Return the kmem_cache we're supposed to use for a slab allocation. | |
3029 | * We try to use the current memcg's version of the cache. | |
3030 | * | |
3031 | * If the cache does not exist yet, if we are the first user of it, | |
3032 | * we either create it immediately, if possible, or create it asynchronously | |
3033 | * in a workqueue. | |
3034 | * In the latter case, we will let the current allocation go through with | |
3035 | * the original cache. | |
3036 | * | |
3037 | * Can't be called in interrupt context or from kernel threads. | |
3038 | * This function needs to be called with rcu_read_lock() held. | |
3039 | */ | |
3040 | struct kmem_cache *__memcg_kmem_get_cache(struct kmem_cache *cachep, | |
3041 | gfp_t gfp) | |
3042 | { | |
3043 | struct mem_cgroup *memcg; | |
959c8963 | 3044 | struct kmem_cache *memcg_cachep; |
d7f25f8a GC |
3045 | |
3046 | VM_BUG_ON(!cachep->memcg_params); | |
3047 | VM_BUG_ON(!cachep->memcg_params->is_root_cache); | |
3048 | ||
0e9d92f2 GC |
3049 | if (!current->mm || current->memcg_kmem_skip_account) |
3050 | return cachep; | |
3051 | ||
d7f25f8a GC |
3052 | rcu_read_lock(); |
3053 | memcg = mem_cgroup_from_task(rcu_dereference(current->mm->owner)); | |
d7f25f8a | 3054 | |
cf2b8fbf | 3055 | if (!memcg_kmem_is_active(memcg)) |
ca0dde97 | 3056 | goto out; |
d7f25f8a | 3057 | |
959c8963 VD |
3058 | memcg_cachep = cache_from_memcg_idx(cachep, memcg_cache_id(memcg)); |
3059 | if (likely(memcg_cachep)) { | |
3060 | cachep = memcg_cachep; | |
ca0dde97 | 3061 | goto out; |
d7f25f8a GC |
3062 | } |
3063 | ||
ca0dde97 | 3064 | /* The corresponding put will be done in the workqueue. */ |
ec903c0c | 3065 | if (!css_tryget_online(&memcg->css)) |
ca0dde97 LZ |
3066 | goto out; |
3067 | rcu_read_unlock(); | |
3068 | ||
3069 | /* | |
3070 | * If we are in a safe context (can wait, and not in interrupt | |
3071 | * context), we could be be predictable and return right away. | |
3072 | * This would guarantee that the allocation being performed | |
3073 | * already belongs in the new cache. | |
3074 | * | |
3075 | * However, there are some clashes that can arrive from locking. | |
3076 | * For instance, because we acquire the slab_mutex while doing | |
776ed0f0 VD |
3077 | * memcg_create_kmem_cache, this means no further allocation |
3078 | * could happen with the slab_mutex held. So it's better to | |
3079 | * defer everything. | |
ca0dde97 | 3080 | */ |
776ed0f0 | 3081 | memcg_schedule_register_cache(memcg, cachep); |
ca0dde97 LZ |
3082 | return cachep; |
3083 | out: | |
3084 | rcu_read_unlock(); | |
3085 | return cachep; | |
d7f25f8a | 3086 | } |
d7f25f8a | 3087 | |
7ae1e1d0 GC |
3088 | /* |
3089 | * We need to verify if the allocation against current->mm->owner's memcg is | |
3090 | * possible for the given order. But the page is not allocated yet, so we'll | |
3091 | * need a further commit step to do the final arrangements. | |
3092 | * | |
3093 | * It is possible for the task to switch cgroups in this mean time, so at | |
3094 | * commit time, we can't rely on task conversion any longer. We'll then use | |
3095 | * the handle argument to return to the caller which cgroup we should commit | |
3096 | * against. We could also return the memcg directly and avoid the pointer | |
3097 | * passing, but a boolean return value gives better semantics considering | |
3098 | * the compiled-out case as well. | |
3099 | * | |
3100 | * Returning true means the allocation is possible. | |
3101 | */ | |
3102 | bool | |
3103 | __memcg_kmem_newpage_charge(gfp_t gfp, struct mem_cgroup **_memcg, int order) | |
3104 | { | |
3105 | struct mem_cgroup *memcg; | |
3106 | int ret; | |
3107 | ||
3108 | *_memcg = NULL; | |
6d42c232 GC |
3109 | |
3110 | /* | |
3111 | * Disabling accounting is only relevant for some specific memcg | |
3112 | * internal allocations. Therefore we would initially not have such | |
52383431 VD |
3113 | * check here, since direct calls to the page allocator that are |
3114 | * accounted to kmemcg (alloc_kmem_pages and friends) only happen | |
3115 | * outside memcg core. We are mostly concerned with cache allocations, | |
3116 | * and by having this test at memcg_kmem_get_cache, we are already able | |
3117 | * to relay the allocation to the root cache and bypass the memcg cache | |
3118 | * altogether. | |
6d42c232 GC |
3119 | * |
3120 | * There is one exception, though: the SLUB allocator does not create | |
3121 | * large order caches, but rather service large kmallocs directly from | |
3122 | * the page allocator. Therefore, the following sequence when backed by | |
3123 | * the SLUB allocator: | |
3124 | * | |
f894ffa8 AM |
3125 | * memcg_stop_kmem_account(); |
3126 | * kmalloc(<large_number>) | |
3127 | * memcg_resume_kmem_account(); | |
6d42c232 GC |
3128 | * |
3129 | * would effectively ignore the fact that we should skip accounting, | |
3130 | * since it will drive us directly to this function without passing | |
3131 | * through the cache selector memcg_kmem_get_cache. Such large | |
3132 | * allocations are extremely rare but can happen, for instance, for the | |
3133 | * cache arrays. We bring this test here. | |
3134 | */ | |
3135 | if (!current->mm || current->memcg_kmem_skip_account) | |
3136 | return true; | |
3137 | ||
df381975 | 3138 | memcg = get_mem_cgroup_from_mm(current->mm); |
7ae1e1d0 | 3139 | |
cf2b8fbf | 3140 | if (!memcg_kmem_is_active(memcg)) { |
7ae1e1d0 GC |
3141 | css_put(&memcg->css); |
3142 | return true; | |
3143 | } | |
3144 | ||
3e32cb2e | 3145 | ret = memcg_charge_kmem(memcg, gfp, 1 << order); |
7ae1e1d0 GC |
3146 | if (!ret) |
3147 | *_memcg = memcg; | |
7ae1e1d0 GC |
3148 | |
3149 | css_put(&memcg->css); | |
3150 | return (ret == 0); | |
3151 | } | |
3152 | ||
3153 | void __memcg_kmem_commit_charge(struct page *page, struct mem_cgroup *memcg, | |
3154 | int order) | |
3155 | { | |
3156 | struct page_cgroup *pc; | |
3157 | ||
3158 | VM_BUG_ON(mem_cgroup_is_root(memcg)); | |
3159 | ||
3160 | /* The page allocation failed. Revert */ | |
3161 | if (!page) { | |
3e32cb2e | 3162 | memcg_uncharge_kmem(memcg, 1 << order); |
7ae1e1d0 GC |
3163 | return; |
3164 | } | |
a840cda6 JW |
3165 | /* |
3166 | * The page is freshly allocated and not visible to any | |
3167 | * outside callers yet. Set up pc non-atomically. | |
3168 | */ | |
7ae1e1d0 | 3169 | pc = lookup_page_cgroup(page); |
7ae1e1d0 | 3170 | pc->mem_cgroup = memcg; |
a840cda6 | 3171 | pc->flags = PCG_USED; |
7ae1e1d0 GC |
3172 | } |
3173 | ||
3174 | void __memcg_kmem_uncharge_pages(struct page *page, int order) | |
3175 | { | |
3176 | struct mem_cgroup *memcg = NULL; | |
3177 | struct page_cgroup *pc; | |
3178 | ||
3179 | ||
3180 | pc = lookup_page_cgroup(page); | |
7ae1e1d0 GC |
3181 | if (!PageCgroupUsed(pc)) |
3182 | return; | |
3183 | ||
a840cda6 JW |
3184 | memcg = pc->mem_cgroup; |
3185 | pc->flags = 0; | |
7ae1e1d0 GC |
3186 | |
3187 | /* | |
3188 | * We trust that only if there is a memcg associated with the page, it | |
3189 | * is a valid allocation | |
3190 | */ | |
3191 | if (!memcg) | |
3192 | return; | |
3193 | ||
309381fe | 3194 | VM_BUG_ON_PAGE(mem_cgroup_is_root(memcg), page); |
3e32cb2e | 3195 | memcg_uncharge_kmem(memcg, 1 << order); |
7ae1e1d0 | 3196 | } |
1f458cbf | 3197 | #else |
776ed0f0 | 3198 | static inline void memcg_unregister_all_caches(struct mem_cgroup *memcg) |
1f458cbf GC |
3199 | { |
3200 | } | |
7ae1e1d0 GC |
3201 | #endif /* CONFIG_MEMCG_KMEM */ |
3202 | ||
ca3e0214 KH |
3203 | #ifdef CONFIG_TRANSPARENT_HUGEPAGE |
3204 | ||
ca3e0214 KH |
3205 | /* |
3206 | * Because tail pages are not marked as "used", set it. We're under | |
e94c8a9c KH |
3207 | * zone->lru_lock, 'splitting on pmd' and compound_lock. |
3208 | * charge/uncharge will be never happen and move_account() is done under | |
3209 | * compound_lock(), so we don't have to take care of races. | |
ca3e0214 | 3210 | */ |
e94c8a9c | 3211 | void mem_cgroup_split_huge_fixup(struct page *head) |
ca3e0214 KH |
3212 | { |
3213 | struct page_cgroup *head_pc = lookup_page_cgroup(head); | |
e94c8a9c | 3214 | struct page_cgroup *pc; |
b070e65c | 3215 | struct mem_cgroup *memcg; |
e94c8a9c | 3216 | int i; |
ca3e0214 | 3217 | |
3d37c4a9 KH |
3218 | if (mem_cgroup_disabled()) |
3219 | return; | |
b070e65c DR |
3220 | |
3221 | memcg = head_pc->mem_cgroup; | |
e94c8a9c KH |
3222 | for (i = 1; i < HPAGE_PMD_NR; i++) { |
3223 | pc = head_pc + i; | |
b070e65c | 3224 | pc->mem_cgroup = memcg; |
0a31bc97 | 3225 | pc->flags = head_pc->flags; |
e94c8a9c | 3226 | } |
b070e65c DR |
3227 | __this_cpu_sub(memcg->stat->count[MEM_CGROUP_STAT_RSS_HUGE], |
3228 | HPAGE_PMD_NR); | |
ca3e0214 | 3229 | } |
12d27107 | 3230 | #endif /* CONFIG_TRANSPARENT_HUGEPAGE */ |
ca3e0214 | 3231 | |
f817ed48 | 3232 | /** |
de3638d9 | 3233 | * mem_cgroup_move_account - move account of the page |
5564e88b | 3234 | * @page: the page |
7ec99d62 | 3235 | * @nr_pages: number of regular pages (>1 for huge pages) |
f817ed48 KH |
3236 | * @pc: page_cgroup of the page. |
3237 | * @from: mem_cgroup which the page is moved from. | |
3238 | * @to: mem_cgroup which the page is moved to. @from != @to. | |
3239 | * | |
3240 | * The caller must confirm following. | |
08e552c6 | 3241 | * - page is not on LRU (isolate_page() is useful.) |
7ec99d62 | 3242 | * - compound_lock is held when nr_pages > 1 |
f817ed48 | 3243 | * |
2f3479b1 KH |
3244 | * This function doesn't do "charge" to new cgroup and doesn't do "uncharge" |
3245 | * from old cgroup. | |
f817ed48 | 3246 | */ |
7ec99d62 JW |
3247 | static int mem_cgroup_move_account(struct page *page, |
3248 | unsigned int nr_pages, | |
3249 | struct page_cgroup *pc, | |
3250 | struct mem_cgroup *from, | |
2f3479b1 | 3251 | struct mem_cgroup *to) |
f817ed48 | 3252 | { |
de3638d9 JW |
3253 | unsigned long flags; |
3254 | int ret; | |
987eba66 | 3255 | |
f817ed48 | 3256 | VM_BUG_ON(from == to); |
309381fe | 3257 | VM_BUG_ON_PAGE(PageLRU(page), page); |
de3638d9 JW |
3258 | /* |
3259 | * The page is isolated from LRU. So, collapse function | |
3260 | * will not handle this page. But page splitting can happen. | |
3261 | * Do this check under compound_page_lock(). The caller should | |
3262 | * hold it. | |
3263 | */ | |
3264 | ret = -EBUSY; | |
7ec99d62 | 3265 | if (nr_pages > 1 && !PageTransHuge(page)) |
de3638d9 JW |
3266 | goto out; |
3267 | ||
0a31bc97 JW |
3268 | /* |
3269 | * Prevent mem_cgroup_migrate() from looking at pc->mem_cgroup | |
3270 | * of its source page while we change it: page migration takes | |
3271 | * both pages off the LRU, but page cache replacement doesn't. | |
3272 | */ | |
3273 | if (!trylock_page(page)) | |
3274 | goto out; | |
de3638d9 JW |
3275 | |
3276 | ret = -EINVAL; | |
3277 | if (!PageCgroupUsed(pc) || pc->mem_cgroup != from) | |
0a31bc97 | 3278 | goto out_unlock; |
de3638d9 | 3279 | |
312734c0 | 3280 | move_lock_mem_cgroup(from, &flags); |
f817ed48 | 3281 | |
0a31bc97 | 3282 | if (!PageAnon(page) && page_mapped(page)) { |
59d1d256 JW |
3283 | __this_cpu_sub(from->stat->count[MEM_CGROUP_STAT_FILE_MAPPED], |
3284 | nr_pages); | |
3285 | __this_cpu_add(to->stat->count[MEM_CGROUP_STAT_FILE_MAPPED], | |
3286 | nr_pages); | |
3287 | } | |
3ea67d06 | 3288 | |
59d1d256 JW |
3289 | if (PageWriteback(page)) { |
3290 | __this_cpu_sub(from->stat->count[MEM_CGROUP_STAT_WRITEBACK], | |
3291 | nr_pages); | |
3292 | __this_cpu_add(to->stat->count[MEM_CGROUP_STAT_WRITEBACK], | |
3293 | nr_pages); | |
3294 | } | |
3ea67d06 | 3295 | |
0a31bc97 JW |
3296 | /* |
3297 | * It is safe to change pc->mem_cgroup here because the page | |
3298 | * is referenced, charged, and isolated - we can't race with | |
3299 | * uncharging, charging, migration, or LRU putback. | |
3300 | */ | |
d69b042f | 3301 | |
854ffa8d | 3302 | /* caller should have done css_get */ |
08e552c6 | 3303 | pc->mem_cgroup = to; |
312734c0 | 3304 | move_unlock_mem_cgroup(from, &flags); |
de3638d9 | 3305 | ret = 0; |
0a31bc97 JW |
3306 | |
3307 | local_irq_disable(); | |
3308 | mem_cgroup_charge_statistics(to, page, nr_pages); | |
5564e88b | 3309 | memcg_check_events(to, page); |
0a31bc97 | 3310 | mem_cgroup_charge_statistics(from, page, -nr_pages); |
5564e88b | 3311 | memcg_check_events(from, page); |
0a31bc97 JW |
3312 | local_irq_enable(); |
3313 | out_unlock: | |
3314 | unlock_page(page); | |
de3638d9 | 3315 | out: |
f817ed48 KH |
3316 | return ret; |
3317 | } | |
3318 | ||
c255a458 | 3319 | #ifdef CONFIG_MEMCG_SWAP |
0a31bc97 JW |
3320 | static void mem_cgroup_swap_statistics(struct mem_cgroup *memcg, |
3321 | bool charge) | |
d13d1443 | 3322 | { |
0a31bc97 JW |
3323 | int val = (charge) ? 1 : -1; |
3324 | this_cpu_add(memcg->stat->count[MEM_CGROUP_STAT_SWAP], val); | |
d13d1443 | 3325 | } |
02491447 DN |
3326 | |
3327 | /** | |
3328 | * mem_cgroup_move_swap_account - move swap charge and swap_cgroup's record. | |
3329 | * @entry: swap entry to be moved | |
3330 | * @from: mem_cgroup which the entry is moved from | |
3331 | * @to: mem_cgroup which the entry is moved to | |
3332 | * | |
3333 | * It succeeds only when the swap_cgroup's record for this entry is the same | |
3334 | * as the mem_cgroup's id of @from. | |
3335 | * | |
3336 | * Returns 0 on success, -EINVAL on failure. | |
3337 | * | |
3e32cb2e | 3338 | * The caller must have charged to @to, IOW, called page_counter_charge() about |
02491447 DN |
3339 | * both res and memsw, and called css_get(). |
3340 | */ | |
3341 | static int mem_cgroup_move_swap_account(swp_entry_t entry, | |
e91cbb42 | 3342 | struct mem_cgroup *from, struct mem_cgroup *to) |
02491447 DN |
3343 | { |
3344 | unsigned short old_id, new_id; | |
3345 | ||
34c00c31 LZ |
3346 | old_id = mem_cgroup_id(from); |
3347 | new_id = mem_cgroup_id(to); | |
02491447 DN |
3348 | |
3349 | if (swap_cgroup_cmpxchg(entry, old_id, new_id) == old_id) { | |
02491447 | 3350 | mem_cgroup_swap_statistics(from, false); |
483c30b5 | 3351 | mem_cgroup_swap_statistics(to, true); |
02491447 | 3352 | /* |
483c30b5 | 3353 | * This function is only called from task migration context now. |
3e32cb2e | 3354 | * It postpones page_counter and refcount handling till the end |
483c30b5 | 3355 | * of task migration(mem_cgroup_clear_mc()) for performance |
4050377b LZ |
3356 | * improvement. But we cannot postpone css_get(to) because if |
3357 | * the process that has been moved to @to does swap-in, the | |
3358 | * refcount of @to might be decreased to 0. | |
3359 | * | |
3360 | * We are in attach() phase, so the cgroup is guaranteed to be | |
3361 | * alive, so we can just call css_get(). | |
02491447 | 3362 | */ |
4050377b | 3363 | css_get(&to->css); |
02491447 DN |
3364 | return 0; |
3365 | } | |
3366 | return -EINVAL; | |
3367 | } | |
3368 | #else | |
3369 | static inline int mem_cgroup_move_swap_account(swp_entry_t entry, | |
e91cbb42 | 3370 | struct mem_cgroup *from, struct mem_cgroup *to) |
02491447 DN |
3371 | { |
3372 | return -EINVAL; | |
3373 | } | |
8c7c6e34 | 3374 | #endif |
d13d1443 | 3375 | |
f212ad7c DN |
3376 | #ifdef CONFIG_DEBUG_VM |
3377 | static struct page_cgroup *lookup_page_cgroup_used(struct page *page) | |
3378 | { | |
3379 | struct page_cgroup *pc; | |
3380 | ||
3381 | pc = lookup_page_cgroup(page); | |
cfa44946 JW |
3382 | /* |
3383 | * Can be NULL while feeding pages into the page allocator for | |
3384 | * the first time, i.e. during boot or memory hotplug; | |
3385 | * or when mem_cgroup_disabled(). | |
3386 | */ | |
f212ad7c DN |
3387 | if (likely(pc) && PageCgroupUsed(pc)) |
3388 | return pc; | |
3389 | return NULL; | |
3390 | } | |
3391 | ||
3392 | bool mem_cgroup_bad_page_check(struct page *page) | |
3393 | { | |
3394 | if (mem_cgroup_disabled()) | |
3395 | return false; | |
3396 | ||
3397 | return lookup_page_cgroup_used(page) != NULL; | |
3398 | } | |
3399 | ||
3400 | void mem_cgroup_print_bad_page(struct page *page) | |
3401 | { | |
3402 | struct page_cgroup *pc; | |
3403 | ||
3404 | pc = lookup_page_cgroup_used(page); | |
3405 | if (pc) { | |
d045197f AM |
3406 | pr_alert("pc:%p pc->flags:%lx pc->mem_cgroup:%p\n", |
3407 | pc, pc->flags, pc->mem_cgroup); | |
f212ad7c DN |
3408 | } |
3409 | } | |
3410 | #endif | |
3411 | ||
3e32cb2e JW |
3412 | static DEFINE_MUTEX(memcg_limit_mutex); |
3413 | ||
d38d2a75 | 3414 | static int mem_cgroup_resize_limit(struct mem_cgroup *memcg, |
3e32cb2e | 3415 | unsigned long limit) |
628f4235 | 3416 | { |
3e32cb2e JW |
3417 | unsigned long curusage; |
3418 | unsigned long oldusage; | |
3419 | bool enlarge = false; | |
81d39c20 | 3420 | int retry_count; |
3e32cb2e | 3421 | int ret; |
81d39c20 KH |
3422 | |
3423 | /* | |
3424 | * For keeping hierarchical_reclaim simple, how long we should retry | |
3425 | * is depends on callers. We set our retry-count to be function | |
3426 | * of # of children which we should visit in this loop. | |
3427 | */ | |
3e32cb2e JW |
3428 | retry_count = MEM_CGROUP_RECLAIM_RETRIES * |
3429 | mem_cgroup_count_children(memcg); | |
81d39c20 | 3430 | |
3e32cb2e | 3431 | oldusage = page_counter_read(&memcg->memory); |
628f4235 | 3432 | |
3e32cb2e | 3433 | do { |
628f4235 KH |
3434 | if (signal_pending(current)) { |
3435 | ret = -EINTR; | |
3436 | break; | |
3437 | } | |
3e32cb2e JW |
3438 | |
3439 | mutex_lock(&memcg_limit_mutex); | |
3440 | if (limit > memcg->memsw.limit) { | |
3441 | mutex_unlock(&memcg_limit_mutex); | |
8c7c6e34 | 3442 | ret = -EINVAL; |
628f4235 KH |
3443 | break; |
3444 | } | |
3e32cb2e JW |
3445 | if (limit > memcg->memory.limit) |
3446 | enlarge = true; | |
3447 | ret = page_counter_limit(&memcg->memory, limit); | |
3448 | mutex_unlock(&memcg_limit_mutex); | |
8c7c6e34 KH |
3449 | |
3450 | if (!ret) | |
3451 | break; | |
3452 | ||
b70a2a21 JW |
3453 | try_to_free_mem_cgroup_pages(memcg, 1, GFP_KERNEL, true); |
3454 | ||
3e32cb2e | 3455 | curusage = page_counter_read(&memcg->memory); |
81d39c20 | 3456 | /* Usage is reduced ? */ |
f894ffa8 | 3457 | if (curusage >= oldusage) |
81d39c20 KH |
3458 | retry_count--; |
3459 | else | |
3460 | oldusage = curusage; | |
3e32cb2e JW |
3461 | } while (retry_count); |
3462 | ||
3c11ecf4 KH |
3463 | if (!ret && enlarge) |
3464 | memcg_oom_recover(memcg); | |
14797e23 | 3465 | |
8c7c6e34 KH |
3466 | return ret; |
3467 | } | |
3468 | ||
338c8431 | 3469 | static int mem_cgroup_resize_memsw_limit(struct mem_cgroup *memcg, |
3e32cb2e | 3470 | unsigned long limit) |
8c7c6e34 | 3471 | { |
3e32cb2e JW |
3472 | unsigned long curusage; |
3473 | unsigned long oldusage; | |
3474 | bool enlarge = false; | |
81d39c20 | 3475 | int retry_count; |
3e32cb2e | 3476 | int ret; |
8c7c6e34 | 3477 | |
81d39c20 | 3478 | /* see mem_cgroup_resize_res_limit */ |
3e32cb2e JW |
3479 | retry_count = MEM_CGROUP_RECLAIM_RETRIES * |
3480 | mem_cgroup_count_children(memcg); | |
3481 | ||
3482 | oldusage = page_counter_read(&memcg->memsw); | |
3483 | ||
3484 | do { | |
8c7c6e34 KH |
3485 | if (signal_pending(current)) { |
3486 | ret = -EINTR; | |
3487 | break; | |
3488 | } | |
3e32cb2e JW |
3489 | |
3490 | mutex_lock(&memcg_limit_mutex); | |
3491 | if (limit < memcg->memory.limit) { | |
3492 | mutex_unlock(&memcg_limit_mutex); | |
8c7c6e34 | 3493 | ret = -EINVAL; |
8c7c6e34 KH |
3494 | break; |
3495 | } | |
3e32cb2e JW |
3496 | if (limit > memcg->memsw.limit) |
3497 | enlarge = true; | |
3498 | ret = page_counter_limit(&memcg->memsw, limit); | |
3499 | mutex_unlock(&memcg_limit_mutex); | |
8c7c6e34 KH |
3500 | |
3501 | if (!ret) | |
3502 | break; | |
3503 | ||
b70a2a21 JW |
3504 | try_to_free_mem_cgroup_pages(memcg, 1, GFP_KERNEL, false); |
3505 | ||
3e32cb2e | 3506 | curusage = page_counter_read(&memcg->memsw); |
81d39c20 | 3507 | /* Usage is reduced ? */ |
8c7c6e34 | 3508 | if (curusage >= oldusage) |
628f4235 | 3509 | retry_count--; |
81d39c20 KH |
3510 | else |
3511 | oldusage = curusage; | |
3e32cb2e JW |
3512 | } while (retry_count); |
3513 | ||
3c11ecf4 KH |
3514 | if (!ret && enlarge) |
3515 | memcg_oom_recover(memcg); | |
3e32cb2e | 3516 | |
628f4235 KH |
3517 | return ret; |
3518 | } | |
3519 | ||
0608f43d AM |
3520 | unsigned long mem_cgroup_soft_limit_reclaim(struct zone *zone, int order, |
3521 | gfp_t gfp_mask, | |
3522 | unsigned long *total_scanned) | |
3523 | { | |
3524 | unsigned long nr_reclaimed = 0; | |
3525 | struct mem_cgroup_per_zone *mz, *next_mz = NULL; | |
3526 | unsigned long reclaimed; | |
3527 | int loop = 0; | |
3528 | struct mem_cgroup_tree_per_zone *mctz; | |
3e32cb2e | 3529 | unsigned long excess; |
0608f43d AM |
3530 | unsigned long nr_scanned; |
3531 | ||
3532 | if (order > 0) | |
3533 | return 0; | |
3534 | ||
3535 | mctz = soft_limit_tree_node_zone(zone_to_nid(zone), zone_idx(zone)); | |
3536 | /* | |
3537 | * This loop can run a while, specially if mem_cgroup's continuously | |
3538 | * keep exceeding their soft limit and putting the system under | |
3539 | * pressure | |
3540 | */ | |
3541 | do { | |
3542 | if (next_mz) | |
3543 | mz = next_mz; | |
3544 | else | |
3545 | mz = mem_cgroup_largest_soft_limit_node(mctz); | |
3546 | if (!mz) | |
3547 | break; | |
3548 | ||
3549 | nr_scanned = 0; | |
3550 | reclaimed = mem_cgroup_soft_reclaim(mz->memcg, zone, | |
3551 | gfp_mask, &nr_scanned); | |
3552 | nr_reclaimed += reclaimed; | |
3553 | *total_scanned += nr_scanned; | |
0a31bc97 | 3554 | spin_lock_irq(&mctz->lock); |
0608f43d AM |
3555 | |
3556 | /* | |
3557 | * If we failed to reclaim anything from this memory cgroup | |
3558 | * it is time to move on to the next cgroup | |
3559 | */ | |
3560 | next_mz = NULL; | |
3561 | if (!reclaimed) { | |
3562 | do { | |
3563 | /* | |
3564 | * Loop until we find yet another one. | |
3565 | * | |
3566 | * By the time we get the soft_limit lock | |
3567 | * again, someone might have aded the | |
3568 | * group back on the RB tree. Iterate to | |
3569 | * make sure we get a different mem. | |
3570 | * mem_cgroup_largest_soft_limit_node returns | |
3571 | * NULL if no other cgroup is present on | |
3572 | * the tree | |
3573 | */ | |
3574 | next_mz = | |
3575 | __mem_cgroup_largest_soft_limit_node(mctz); | |
3576 | if (next_mz == mz) | |
3577 | css_put(&next_mz->memcg->css); | |
3578 | else /* next_mz == NULL or other memcg */ | |
3579 | break; | |
3580 | } while (1); | |
3581 | } | |
cf2c8127 | 3582 | __mem_cgroup_remove_exceeded(mz, mctz); |
3e32cb2e | 3583 | excess = soft_limit_excess(mz->memcg); |
0608f43d AM |
3584 | /* |
3585 | * One school of thought says that we should not add | |
3586 | * back the node to the tree if reclaim returns 0. | |
3587 | * But our reclaim could return 0, simply because due | |
3588 | * to priority we are exposing a smaller subset of | |
3589 | * memory to reclaim from. Consider this as a longer | |
3590 | * term TODO. | |
3591 | */ | |
3592 | /* If excess == 0, no tree ops */ | |
cf2c8127 | 3593 | __mem_cgroup_insert_exceeded(mz, mctz, excess); |
0a31bc97 | 3594 | spin_unlock_irq(&mctz->lock); |
0608f43d AM |
3595 | css_put(&mz->memcg->css); |
3596 | loop++; | |
3597 | /* | |
3598 | * Could not reclaim anything and there are no more | |
3599 | * mem cgroups to try or we seem to be looping without | |
3600 | * reclaiming anything. | |
3601 | */ | |
3602 | if (!nr_reclaimed && | |
3603 | (next_mz == NULL || | |
3604 | loop > MEM_CGROUP_MAX_SOFT_LIMIT_RECLAIM_LOOPS)) | |
3605 | break; | |
3606 | } while (!nr_reclaimed); | |
3607 | if (next_mz) | |
3608 | css_put(&next_mz->memcg->css); | |
3609 | return nr_reclaimed; | |
3610 | } | |
3611 | ||
ea280e7b TH |
3612 | /* |
3613 | * Test whether @memcg has children, dead or alive. Note that this | |
3614 | * function doesn't care whether @memcg has use_hierarchy enabled and | |
3615 | * returns %true if there are child csses according to the cgroup | |
3616 | * hierarchy. Testing use_hierarchy is the caller's responsiblity. | |
3617 | */ | |
b5f99b53 GC |
3618 | static inline bool memcg_has_children(struct mem_cgroup *memcg) |
3619 | { | |
ea280e7b TH |
3620 | bool ret; |
3621 | ||
696ac172 | 3622 | /* |
ea280e7b TH |
3623 | * The lock does not prevent addition or deletion of children, but |
3624 | * it prevents a new child from being initialized based on this | |
3625 | * parent in css_online(), so it's enough to decide whether | |
3626 | * hierarchically inherited attributes can still be changed or not. | |
696ac172 | 3627 | */ |
ea280e7b TH |
3628 | lockdep_assert_held(&memcg_create_mutex); |
3629 | ||
3630 | rcu_read_lock(); | |
3631 | ret = css_next_child(NULL, &memcg->css); | |
3632 | rcu_read_unlock(); | |
3633 | return ret; | |
b5f99b53 GC |
3634 | } |
3635 | ||
c26251f9 MH |
3636 | /* |
3637 | * Reclaims as many pages from the given memcg as possible and moves | |
3638 | * the rest to the parent. | |
3639 | * | |
3640 | * Caller is responsible for holding css reference for memcg. | |
3641 | */ | |
3642 | static int mem_cgroup_force_empty(struct mem_cgroup *memcg) | |
3643 | { | |
3644 | int nr_retries = MEM_CGROUP_RECLAIM_RETRIES; | |
c26251f9 | 3645 | |
c1e862c1 KH |
3646 | /* we call try-to-free pages for make this cgroup empty */ |
3647 | lru_add_drain_all(); | |
f817ed48 | 3648 | /* try to free all pages in this cgroup */ |
3e32cb2e | 3649 | while (nr_retries && page_counter_read(&memcg->memory)) { |
f817ed48 | 3650 | int progress; |
c1e862c1 | 3651 | |
c26251f9 MH |
3652 | if (signal_pending(current)) |
3653 | return -EINTR; | |
3654 | ||
b70a2a21 JW |
3655 | progress = try_to_free_mem_cgroup_pages(memcg, 1, |
3656 | GFP_KERNEL, true); | |
c1e862c1 | 3657 | if (!progress) { |
f817ed48 | 3658 | nr_retries--; |
c1e862c1 | 3659 | /* maybe some writeback is necessary */ |
8aa7e847 | 3660 | congestion_wait(BLK_RW_ASYNC, HZ/10); |
c1e862c1 | 3661 | } |
f817ed48 KH |
3662 | |
3663 | } | |
ab5196c2 MH |
3664 | |
3665 | return 0; | |
cc847582 KH |
3666 | } |
3667 | ||
6770c64e TH |
3668 | static ssize_t mem_cgroup_force_empty_write(struct kernfs_open_file *of, |
3669 | char *buf, size_t nbytes, | |
3670 | loff_t off) | |
c1e862c1 | 3671 | { |
6770c64e | 3672 | struct mem_cgroup *memcg = mem_cgroup_from_css(of_css(of)); |
c26251f9 | 3673 | |
d8423011 MH |
3674 | if (mem_cgroup_is_root(memcg)) |
3675 | return -EINVAL; | |
6770c64e | 3676 | return mem_cgroup_force_empty(memcg) ?: nbytes; |
c1e862c1 KH |
3677 | } |
3678 | ||
182446d0 TH |
3679 | static u64 mem_cgroup_hierarchy_read(struct cgroup_subsys_state *css, |
3680 | struct cftype *cft) | |
18f59ea7 | 3681 | { |
182446d0 | 3682 | return mem_cgroup_from_css(css)->use_hierarchy; |
18f59ea7 BS |
3683 | } |
3684 | ||
182446d0 TH |
3685 | static int mem_cgroup_hierarchy_write(struct cgroup_subsys_state *css, |
3686 | struct cftype *cft, u64 val) | |
18f59ea7 BS |
3687 | { |
3688 | int retval = 0; | |
182446d0 | 3689 | struct mem_cgroup *memcg = mem_cgroup_from_css(css); |
5c9d535b | 3690 | struct mem_cgroup *parent_memcg = mem_cgroup_from_css(memcg->css.parent); |
18f59ea7 | 3691 | |
0999821b | 3692 | mutex_lock(&memcg_create_mutex); |
567fb435 GC |
3693 | |
3694 | if (memcg->use_hierarchy == val) | |
3695 | goto out; | |
3696 | ||
18f59ea7 | 3697 | /* |
af901ca1 | 3698 | * If parent's use_hierarchy is set, we can't make any modifications |
18f59ea7 BS |
3699 | * in the child subtrees. If it is unset, then the change can |
3700 | * occur, provided the current cgroup has no children. | |
3701 | * | |
3702 | * For the root cgroup, parent_mem is NULL, we allow value to be | |
3703 | * set if there are no children. | |
3704 | */ | |
c0ff4b85 | 3705 | if ((!parent_memcg || !parent_memcg->use_hierarchy) && |
18f59ea7 | 3706 | (val == 1 || val == 0)) { |
ea280e7b | 3707 | if (!memcg_has_children(memcg)) |
c0ff4b85 | 3708 | memcg->use_hierarchy = val; |
18f59ea7 BS |
3709 | else |
3710 | retval = -EBUSY; | |
3711 | } else | |
3712 | retval = -EINVAL; | |
567fb435 GC |
3713 | |
3714 | out: | |
0999821b | 3715 | mutex_unlock(&memcg_create_mutex); |
18f59ea7 BS |
3716 | |
3717 | return retval; | |
3718 | } | |
3719 | ||
3e32cb2e JW |
3720 | static unsigned long tree_stat(struct mem_cgroup *memcg, |
3721 | enum mem_cgroup_stat_index idx) | |
ce00a967 JW |
3722 | { |
3723 | struct mem_cgroup *iter; | |
3724 | long val = 0; | |
3725 | ||
3726 | /* Per-cpu values can be negative, use a signed accumulator */ | |
3727 | for_each_mem_cgroup_tree(iter, memcg) | |
3728 | val += mem_cgroup_read_stat(iter, idx); | |
3729 | ||
3730 | if (val < 0) /* race ? */ | |
3731 | val = 0; | |
3732 | return val; | |
3733 | } | |
3734 | ||
3735 | static inline u64 mem_cgroup_usage(struct mem_cgroup *memcg, bool swap) | |
3736 | { | |
3737 | u64 val; | |
3738 | ||
3e32cb2e JW |
3739 | if (mem_cgroup_is_root(memcg)) { |
3740 | val = tree_stat(memcg, MEM_CGROUP_STAT_CACHE); | |
3741 | val += tree_stat(memcg, MEM_CGROUP_STAT_RSS); | |
3742 | if (swap) | |
3743 | val += tree_stat(memcg, MEM_CGROUP_STAT_SWAP); | |
3744 | } else { | |
ce00a967 | 3745 | if (!swap) |
3e32cb2e | 3746 | val = page_counter_read(&memcg->memory); |
ce00a967 | 3747 | else |
3e32cb2e | 3748 | val = page_counter_read(&memcg->memsw); |
ce00a967 | 3749 | } |
ce00a967 JW |
3750 | return val << PAGE_SHIFT; |
3751 | } | |
3752 | ||
3e32cb2e JW |
3753 | enum { |
3754 | RES_USAGE, | |
3755 | RES_LIMIT, | |
3756 | RES_MAX_USAGE, | |
3757 | RES_FAILCNT, | |
3758 | RES_SOFT_LIMIT, | |
3759 | }; | |
ce00a967 | 3760 | |
791badbd | 3761 | static u64 mem_cgroup_read_u64(struct cgroup_subsys_state *css, |
05b84301 | 3762 | struct cftype *cft) |
8cdea7c0 | 3763 | { |
182446d0 | 3764 | struct mem_cgroup *memcg = mem_cgroup_from_css(css); |
3e32cb2e | 3765 | struct page_counter *counter; |
af36f906 | 3766 | |
3e32cb2e | 3767 | switch (MEMFILE_TYPE(cft->private)) { |
8c7c6e34 | 3768 | case _MEM: |
3e32cb2e JW |
3769 | counter = &memcg->memory; |
3770 | break; | |
8c7c6e34 | 3771 | case _MEMSWAP: |
3e32cb2e JW |
3772 | counter = &memcg->memsw; |
3773 | break; | |
510fc4e1 | 3774 | case _KMEM: |
3e32cb2e | 3775 | counter = &memcg->kmem; |
510fc4e1 | 3776 | break; |
8c7c6e34 KH |
3777 | default: |
3778 | BUG(); | |
8c7c6e34 | 3779 | } |
3e32cb2e JW |
3780 | |
3781 | switch (MEMFILE_ATTR(cft->private)) { | |
3782 | case RES_USAGE: | |
3783 | if (counter == &memcg->memory) | |
3784 | return mem_cgroup_usage(memcg, false); | |
3785 | if (counter == &memcg->memsw) | |
3786 | return mem_cgroup_usage(memcg, true); | |
3787 | return (u64)page_counter_read(counter) * PAGE_SIZE; | |
3788 | case RES_LIMIT: | |
3789 | return (u64)counter->limit * PAGE_SIZE; | |
3790 | case RES_MAX_USAGE: | |
3791 | return (u64)counter->watermark * PAGE_SIZE; | |
3792 | case RES_FAILCNT: | |
3793 | return counter->failcnt; | |
3794 | case RES_SOFT_LIMIT: | |
3795 | return (u64)memcg->soft_limit * PAGE_SIZE; | |
3796 | default: | |
3797 | BUG(); | |
3798 | } | |
8cdea7c0 | 3799 | } |
510fc4e1 | 3800 | |
510fc4e1 | 3801 | #ifdef CONFIG_MEMCG_KMEM |
d6441637 VD |
3802 | /* should be called with activate_kmem_mutex held */ |
3803 | static int __memcg_activate_kmem(struct mem_cgroup *memcg, | |
3e32cb2e | 3804 | unsigned long nr_pages) |
d6441637 VD |
3805 | { |
3806 | int err = 0; | |
3807 | int memcg_id; | |
3808 | ||
3809 | if (memcg_kmem_is_active(memcg)) | |
3810 | return 0; | |
3811 | ||
3812 | /* | |
3813 | * We are going to allocate memory for data shared by all memory | |
3814 | * cgroups so let's stop accounting here. | |
3815 | */ | |
3816 | memcg_stop_kmem_account(); | |
3817 | ||
510fc4e1 GC |
3818 | /* |
3819 | * For simplicity, we won't allow this to be disabled. It also can't | |
3820 | * be changed if the cgroup has children already, or if tasks had | |
3821 | * already joined. | |
3822 | * | |
3823 | * If tasks join before we set the limit, a person looking at | |
3824 | * kmem.usage_in_bytes will have no way to determine when it took | |
3825 | * place, which makes the value quite meaningless. | |
3826 | * | |
3827 | * After it first became limited, changes in the value of the limit are | |
3828 | * of course permitted. | |
510fc4e1 | 3829 | */ |
0999821b | 3830 | mutex_lock(&memcg_create_mutex); |
ea280e7b TH |
3831 | if (cgroup_has_tasks(memcg->css.cgroup) || |
3832 | (memcg->use_hierarchy && memcg_has_children(memcg))) | |
d6441637 VD |
3833 | err = -EBUSY; |
3834 | mutex_unlock(&memcg_create_mutex); | |
3835 | if (err) | |
3836 | goto out; | |
510fc4e1 | 3837 | |
f3bb3043 | 3838 | memcg_id = memcg_alloc_cache_id(); |
d6441637 VD |
3839 | if (memcg_id < 0) { |
3840 | err = memcg_id; | |
3841 | goto out; | |
3842 | } | |
3843 | ||
d6441637 VD |
3844 | memcg->kmemcg_id = memcg_id; |
3845 | INIT_LIST_HEAD(&memcg->memcg_slab_caches); | |
d6441637 VD |
3846 | |
3847 | /* | |
3848 | * We couldn't have accounted to this cgroup, because it hasn't got the | |
3849 | * active bit set yet, so this should succeed. | |
3850 | */ | |
3e32cb2e | 3851 | err = page_counter_limit(&memcg->kmem, nr_pages); |
d6441637 VD |
3852 | VM_BUG_ON(err); |
3853 | ||
3854 | static_key_slow_inc(&memcg_kmem_enabled_key); | |
3855 | /* | |
3856 | * Setting the active bit after enabling static branching will | |
3857 | * guarantee no one starts accounting before all call sites are | |
3858 | * patched. | |
3859 | */ | |
3860 | memcg_kmem_set_active(memcg); | |
510fc4e1 | 3861 | out: |
d6441637 VD |
3862 | memcg_resume_kmem_account(); |
3863 | return err; | |
d6441637 VD |
3864 | } |
3865 | ||
3866 | static int memcg_activate_kmem(struct mem_cgroup *memcg, | |
3e32cb2e | 3867 | unsigned long nr_pages) |
d6441637 VD |
3868 | { |
3869 | int ret; | |
3870 | ||
3871 | mutex_lock(&activate_kmem_mutex); | |
3e32cb2e | 3872 | ret = __memcg_activate_kmem(memcg, nr_pages); |
d6441637 VD |
3873 | mutex_unlock(&activate_kmem_mutex); |
3874 | return ret; | |
3875 | } | |
3876 | ||
3877 | static int memcg_update_kmem_limit(struct mem_cgroup *memcg, | |
3e32cb2e | 3878 | unsigned long limit) |
d6441637 VD |
3879 | { |
3880 | int ret; | |
3881 | ||
3e32cb2e | 3882 | mutex_lock(&memcg_limit_mutex); |
d6441637 | 3883 | if (!memcg_kmem_is_active(memcg)) |
3e32cb2e | 3884 | ret = memcg_activate_kmem(memcg, limit); |
d6441637 | 3885 | else |
3e32cb2e JW |
3886 | ret = page_counter_limit(&memcg->kmem, limit); |
3887 | mutex_unlock(&memcg_limit_mutex); | |
510fc4e1 GC |
3888 | return ret; |
3889 | } | |
3890 | ||
55007d84 | 3891 | static int memcg_propagate_kmem(struct mem_cgroup *memcg) |
510fc4e1 | 3892 | { |
55007d84 | 3893 | int ret = 0; |
510fc4e1 | 3894 | struct mem_cgroup *parent = parent_mem_cgroup(memcg); |
55007d84 | 3895 | |
d6441637 VD |
3896 | if (!parent) |
3897 | return 0; | |
55007d84 | 3898 | |
d6441637 | 3899 | mutex_lock(&activate_kmem_mutex); |
55007d84 | 3900 | /* |
d6441637 VD |
3901 | * If the parent cgroup is not kmem-active now, it cannot be activated |
3902 | * after this point, because it has at least one child already. | |
55007d84 | 3903 | */ |
d6441637 | 3904 | if (memcg_kmem_is_active(parent)) |
3e32cb2e | 3905 | ret = __memcg_activate_kmem(memcg, PAGE_COUNTER_MAX); |
d6441637 | 3906 | mutex_unlock(&activate_kmem_mutex); |
55007d84 | 3907 | return ret; |
510fc4e1 | 3908 | } |
d6441637 VD |
3909 | #else |
3910 | static int memcg_update_kmem_limit(struct mem_cgroup *memcg, | |
3e32cb2e | 3911 | unsigned long limit) |
d6441637 VD |
3912 | { |
3913 | return -EINVAL; | |
3914 | } | |
6d043990 | 3915 | #endif /* CONFIG_MEMCG_KMEM */ |
510fc4e1 | 3916 | |
628f4235 KH |
3917 | /* |
3918 | * The user of this function is... | |
3919 | * RES_LIMIT. | |
3920 | */ | |
451af504 TH |
3921 | static ssize_t mem_cgroup_write(struct kernfs_open_file *of, |
3922 | char *buf, size_t nbytes, loff_t off) | |
8cdea7c0 | 3923 | { |
451af504 | 3924 | struct mem_cgroup *memcg = mem_cgroup_from_css(of_css(of)); |
3e32cb2e | 3925 | unsigned long nr_pages; |
628f4235 KH |
3926 | int ret; |
3927 | ||
451af504 | 3928 | buf = strstrip(buf); |
3e32cb2e JW |
3929 | ret = page_counter_memparse(buf, &nr_pages); |
3930 | if (ret) | |
3931 | return ret; | |
af36f906 | 3932 | |
3e32cb2e | 3933 | switch (MEMFILE_ATTR(of_cft(of)->private)) { |
628f4235 | 3934 | case RES_LIMIT: |
4b3bde4c BS |
3935 | if (mem_cgroup_is_root(memcg)) { /* Can't set limit on root */ |
3936 | ret = -EINVAL; | |
3937 | break; | |
3938 | } | |
3e32cb2e JW |
3939 | switch (MEMFILE_TYPE(of_cft(of)->private)) { |
3940 | case _MEM: | |
3941 | ret = mem_cgroup_resize_limit(memcg, nr_pages); | |
8c7c6e34 | 3942 | break; |
3e32cb2e JW |
3943 | case _MEMSWAP: |
3944 | ret = mem_cgroup_resize_memsw_limit(memcg, nr_pages); | |
296c81d8 | 3945 | break; |
3e32cb2e JW |
3946 | case _KMEM: |
3947 | ret = memcg_update_kmem_limit(memcg, nr_pages); | |
3948 | break; | |
3949 | } | |
296c81d8 | 3950 | break; |
3e32cb2e JW |
3951 | case RES_SOFT_LIMIT: |
3952 | memcg->soft_limit = nr_pages; | |
3953 | ret = 0; | |
628f4235 KH |
3954 | break; |
3955 | } | |
451af504 | 3956 | return ret ?: nbytes; |
8cdea7c0 BS |
3957 | } |
3958 | ||
6770c64e TH |
3959 | static ssize_t mem_cgroup_reset(struct kernfs_open_file *of, char *buf, |
3960 | size_t nbytes, loff_t off) | |
c84872e1 | 3961 | { |
6770c64e | 3962 | struct mem_cgroup *memcg = mem_cgroup_from_css(of_css(of)); |
3e32cb2e | 3963 | struct page_counter *counter; |
c84872e1 | 3964 | |
3e32cb2e JW |
3965 | switch (MEMFILE_TYPE(of_cft(of)->private)) { |
3966 | case _MEM: | |
3967 | counter = &memcg->memory; | |
3968 | break; | |
3969 | case _MEMSWAP: | |
3970 | counter = &memcg->memsw; | |
3971 | break; | |
3972 | case _KMEM: | |
3973 | counter = &memcg->kmem; | |
3974 | break; | |
3975 | default: | |
3976 | BUG(); | |
3977 | } | |
af36f906 | 3978 | |
3e32cb2e | 3979 | switch (MEMFILE_ATTR(of_cft(of)->private)) { |
29f2a4da | 3980 | case RES_MAX_USAGE: |
3e32cb2e | 3981 | page_counter_reset_watermark(counter); |
29f2a4da PE |
3982 | break; |
3983 | case RES_FAILCNT: | |
3e32cb2e | 3984 | counter->failcnt = 0; |
29f2a4da | 3985 | break; |
3e32cb2e JW |
3986 | default: |
3987 | BUG(); | |
29f2a4da | 3988 | } |
f64c3f54 | 3989 | |
6770c64e | 3990 | return nbytes; |
c84872e1 PE |
3991 | } |
3992 | ||
182446d0 | 3993 | static u64 mem_cgroup_move_charge_read(struct cgroup_subsys_state *css, |
7dc74be0 DN |
3994 | struct cftype *cft) |
3995 | { | |
182446d0 | 3996 | return mem_cgroup_from_css(css)->move_charge_at_immigrate; |
7dc74be0 DN |
3997 | } |
3998 | ||
02491447 | 3999 | #ifdef CONFIG_MMU |
182446d0 | 4000 | static int mem_cgroup_move_charge_write(struct cgroup_subsys_state *css, |
7dc74be0 DN |
4001 | struct cftype *cft, u64 val) |
4002 | { | |
182446d0 | 4003 | struct mem_cgroup *memcg = mem_cgroup_from_css(css); |
7dc74be0 DN |
4004 | |
4005 | if (val >= (1 << NR_MOVE_TYPE)) | |
4006 | return -EINVAL; | |
ee5e8472 | 4007 | |
7dc74be0 | 4008 | /* |
ee5e8472 GC |
4009 | * No kind of locking is needed in here, because ->can_attach() will |
4010 | * check this value once in the beginning of the process, and then carry | |
4011 | * on with stale data. This means that changes to this value will only | |
4012 | * affect task migrations starting after the change. | |
7dc74be0 | 4013 | */ |
c0ff4b85 | 4014 | memcg->move_charge_at_immigrate = val; |
7dc74be0 DN |
4015 | return 0; |
4016 | } | |
02491447 | 4017 | #else |
182446d0 | 4018 | static int mem_cgroup_move_charge_write(struct cgroup_subsys_state *css, |
02491447 DN |
4019 | struct cftype *cft, u64 val) |
4020 | { | |
4021 | return -ENOSYS; | |
4022 | } | |
4023 | #endif | |
7dc74be0 | 4024 | |
406eb0c9 | 4025 | #ifdef CONFIG_NUMA |
2da8ca82 | 4026 | static int memcg_numa_stat_show(struct seq_file *m, void *v) |
406eb0c9 | 4027 | { |
25485de6 GT |
4028 | struct numa_stat { |
4029 | const char *name; | |
4030 | unsigned int lru_mask; | |
4031 | }; | |
4032 | ||
4033 | static const struct numa_stat stats[] = { | |
4034 | { "total", LRU_ALL }, | |
4035 | { "file", LRU_ALL_FILE }, | |
4036 | { "anon", LRU_ALL_ANON }, | |
4037 | { "unevictable", BIT(LRU_UNEVICTABLE) }, | |
4038 | }; | |
4039 | const struct numa_stat *stat; | |
406eb0c9 | 4040 | int nid; |
25485de6 | 4041 | unsigned long nr; |
2da8ca82 | 4042 | struct mem_cgroup *memcg = mem_cgroup_from_css(seq_css(m)); |
406eb0c9 | 4043 | |
25485de6 GT |
4044 | for (stat = stats; stat < stats + ARRAY_SIZE(stats); stat++) { |
4045 | nr = mem_cgroup_nr_lru_pages(memcg, stat->lru_mask); | |
4046 | seq_printf(m, "%s=%lu", stat->name, nr); | |
4047 | for_each_node_state(nid, N_MEMORY) { | |
4048 | nr = mem_cgroup_node_nr_lru_pages(memcg, nid, | |
4049 | stat->lru_mask); | |
4050 | seq_printf(m, " N%d=%lu", nid, nr); | |
4051 | } | |
4052 | seq_putc(m, '\n'); | |
406eb0c9 | 4053 | } |
406eb0c9 | 4054 | |
071aee13 YH |
4055 | for (stat = stats; stat < stats + ARRAY_SIZE(stats); stat++) { |
4056 | struct mem_cgroup *iter; | |
4057 | ||
4058 | nr = 0; | |
4059 | for_each_mem_cgroup_tree(iter, memcg) | |
4060 | nr += mem_cgroup_nr_lru_pages(iter, stat->lru_mask); | |
4061 | seq_printf(m, "hierarchical_%s=%lu", stat->name, nr); | |
4062 | for_each_node_state(nid, N_MEMORY) { | |
4063 | nr = 0; | |
4064 | for_each_mem_cgroup_tree(iter, memcg) | |
4065 | nr += mem_cgroup_node_nr_lru_pages( | |
4066 | iter, nid, stat->lru_mask); | |
4067 | seq_printf(m, " N%d=%lu", nid, nr); | |
4068 | } | |
4069 | seq_putc(m, '\n'); | |
406eb0c9 | 4070 | } |
406eb0c9 | 4071 | |
406eb0c9 YH |
4072 | return 0; |
4073 | } | |
4074 | #endif /* CONFIG_NUMA */ | |
4075 | ||
af7c4b0e JW |
4076 | static inline void mem_cgroup_lru_names_not_uptodate(void) |
4077 | { | |
4078 | BUILD_BUG_ON(ARRAY_SIZE(mem_cgroup_lru_names) != NR_LRU_LISTS); | |
4079 | } | |
4080 | ||
2da8ca82 | 4081 | static int memcg_stat_show(struct seq_file *m, void *v) |
d2ceb9b7 | 4082 | { |
2da8ca82 | 4083 | struct mem_cgroup *memcg = mem_cgroup_from_css(seq_css(m)); |
3e32cb2e | 4084 | unsigned long memory, memsw; |
af7c4b0e JW |
4085 | struct mem_cgroup *mi; |
4086 | unsigned int i; | |
406eb0c9 | 4087 | |
af7c4b0e | 4088 | for (i = 0; i < MEM_CGROUP_STAT_NSTATS; i++) { |
bff6bb83 | 4089 | if (i == MEM_CGROUP_STAT_SWAP && !do_swap_account) |
1dd3a273 | 4090 | continue; |
af7c4b0e JW |
4091 | seq_printf(m, "%s %ld\n", mem_cgroup_stat_names[i], |
4092 | mem_cgroup_read_stat(memcg, i) * PAGE_SIZE); | |
1dd3a273 | 4093 | } |
7b854121 | 4094 | |
af7c4b0e JW |
4095 | for (i = 0; i < MEM_CGROUP_EVENTS_NSTATS; i++) |
4096 | seq_printf(m, "%s %lu\n", mem_cgroup_events_names[i], | |
4097 | mem_cgroup_read_events(memcg, i)); | |
4098 | ||
4099 | for (i = 0; i < NR_LRU_LISTS; i++) | |
4100 | seq_printf(m, "%s %lu\n", mem_cgroup_lru_names[i], | |
4101 | mem_cgroup_nr_lru_pages(memcg, BIT(i)) * PAGE_SIZE); | |
4102 | ||
14067bb3 | 4103 | /* Hierarchical information */ |
3e32cb2e JW |
4104 | memory = memsw = PAGE_COUNTER_MAX; |
4105 | for (mi = memcg; mi; mi = parent_mem_cgroup(mi)) { | |
4106 | memory = min(memory, mi->memory.limit); | |
4107 | memsw = min(memsw, mi->memsw.limit); | |
fee7b548 | 4108 | } |
3e32cb2e JW |
4109 | seq_printf(m, "hierarchical_memory_limit %llu\n", |
4110 | (u64)memory * PAGE_SIZE); | |
4111 | if (do_swap_account) | |
4112 | seq_printf(m, "hierarchical_memsw_limit %llu\n", | |
4113 | (u64)memsw * PAGE_SIZE); | |
7f016ee8 | 4114 | |
af7c4b0e JW |
4115 | for (i = 0; i < MEM_CGROUP_STAT_NSTATS; i++) { |
4116 | long long val = 0; | |
4117 | ||
bff6bb83 | 4118 | if (i == MEM_CGROUP_STAT_SWAP && !do_swap_account) |
1dd3a273 | 4119 | continue; |
af7c4b0e JW |
4120 | for_each_mem_cgroup_tree(mi, memcg) |
4121 | val += mem_cgroup_read_stat(mi, i) * PAGE_SIZE; | |
4122 | seq_printf(m, "total_%s %lld\n", mem_cgroup_stat_names[i], val); | |
4123 | } | |
4124 | ||
4125 | for (i = 0; i < MEM_CGROUP_EVENTS_NSTATS; i++) { | |
4126 | unsigned long long val = 0; | |
4127 | ||
4128 | for_each_mem_cgroup_tree(mi, memcg) | |
4129 | val += mem_cgroup_read_events(mi, i); | |
4130 | seq_printf(m, "total_%s %llu\n", | |
4131 | mem_cgroup_events_names[i], val); | |
4132 | } | |
4133 | ||
4134 | for (i = 0; i < NR_LRU_LISTS; i++) { | |
4135 | unsigned long long val = 0; | |
4136 | ||
4137 | for_each_mem_cgroup_tree(mi, memcg) | |
4138 | val += mem_cgroup_nr_lru_pages(mi, BIT(i)) * PAGE_SIZE; | |
4139 | seq_printf(m, "total_%s %llu\n", mem_cgroup_lru_names[i], val); | |
1dd3a273 | 4140 | } |
14067bb3 | 4141 | |
7f016ee8 | 4142 | #ifdef CONFIG_DEBUG_VM |
7f016ee8 KM |
4143 | { |
4144 | int nid, zid; | |
4145 | struct mem_cgroup_per_zone *mz; | |
89abfab1 | 4146 | struct zone_reclaim_stat *rstat; |
7f016ee8 KM |
4147 | unsigned long recent_rotated[2] = {0, 0}; |
4148 | unsigned long recent_scanned[2] = {0, 0}; | |
4149 | ||
4150 | for_each_online_node(nid) | |
4151 | for (zid = 0; zid < MAX_NR_ZONES; zid++) { | |
e231875b | 4152 | mz = &memcg->nodeinfo[nid]->zoneinfo[zid]; |
89abfab1 | 4153 | rstat = &mz->lruvec.reclaim_stat; |
7f016ee8 | 4154 | |
89abfab1 HD |
4155 | recent_rotated[0] += rstat->recent_rotated[0]; |
4156 | recent_rotated[1] += rstat->recent_rotated[1]; | |
4157 | recent_scanned[0] += rstat->recent_scanned[0]; | |
4158 | recent_scanned[1] += rstat->recent_scanned[1]; | |
7f016ee8 | 4159 | } |
78ccf5b5 JW |
4160 | seq_printf(m, "recent_rotated_anon %lu\n", recent_rotated[0]); |
4161 | seq_printf(m, "recent_rotated_file %lu\n", recent_rotated[1]); | |
4162 | seq_printf(m, "recent_scanned_anon %lu\n", recent_scanned[0]); | |
4163 | seq_printf(m, "recent_scanned_file %lu\n", recent_scanned[1]); | |
7f016ee8 KM |
4164 | } |
4165 | #endif | |
4166 | ||
d2ceb9b7 KH |
4167 | return 0; |
4168 | } | |
4169 | ||
182446d0 TH |
4170 | static u64 mem_cgroup_swappiness_read(struct cgroup_subsys_state *css, |
4171 | struct cftype *cft) | |
a7885eb8 | 4172 | { |
182446d0 | 4173 | struct mem_cgroup *memcg = mem_cgroup_from_css(css); |
a7885eb8 | 4174 | |
1f4c025b | 4175 | return mem_cgroup_swappiness(memcg); |
a7885eb8 KM |
4176 | } |
4177 | ||
182446d0 TH |
4178 | static int mem_cgroup_swappiness_write(struct cgroup_subsys_state *css, |
4179 | struct cftype *cft, u64 val) | |
a7885eb8 | 4180 | { |
182446d0 | 4181 | struct mem_cgroup *memcg = mem_cgroup_from_css(css); |
a7885eb8 | 4182 | |
3dae7fec | 4183 | if (val > 100) |
a7885eb8 KM |
4184 | return -EINVAL; |
4185 | ||
14208b0e | 4186 | if (css->parent) |
3dae7fec JW |
4187 | memcg->swappiness = val; |
4188 | else | |
4189 | vm_swappiness = val; | |
068b38c1 | 4190 | |
a7885eb8 KM |
4191 | return 0; |
4192 | } | |
4193 | ||
2e72b634 KS |
4194 | static void __mem_cgroup_threshold(struct mem_cgroup *memcg, bool swap) |
4195 | { | |
4196 | struct mem_cgroup_threshold_ary *t; | |
3e32cb2e | 4197 | unsigned long usage; |
2e72b634 KS |
4198 | int i; |
4199 | ||
4200 | rcu_read_lock(); | |
4201 | if (!swap) | |
2c488db2 | 4202 | t = rcu_dereference(memcg->thresholds.primary); |
2e72b634 | 4203 | else |
2c488db2 | 4204 | t = rcu_dereference(memcg->memsw_thresholds.primary); |
2e72b634 KS |
4205 | |
4206 | if (!t) | |
4207 | goto unlock; | |
4208 | ||
ce00a967 | 4209 | usage = mem_cgroup_usage(memcg, swap); |
2e72b634 KS |
4210 | |
4211 | /* | |
748dad36 | 4212 | * current_threshold points to threshold just below or equal to usage. |
2e72b634 KS |
4213 | * If it's not true, a threshold was crossed after last |
4214 | * call of __mem_cgroup_threshold(). | |
4215 | */ | |
5407a562 | 4216 | i = t->current_threshold; |
2e72b634 KS |
4217 | |
4218 | /* | |
4219 | * Iterate backward over array of thresholds starting from | |
4220 | * current_threshold and check if a threshold is crossed. | |
4221 | * If none of thresholds below usage is crossed, we read | |
4222 | * only one element of the array here. | |
4223 | */ | |
4224 | for (; i >= 0 && unlikely(t->entries[i].threshold > usage); i--) | |
4225 | eventfd_signal(t->entries[i].eventfd, 1); | |
4226 | ||
4227 | /* i = current_threshold + 1 */ | |
4228 | i++; | |
4229 | ||
4230 | /* | |
4231 | * Iterate forward over array of thresholds starting from | |
4232 | * current_threshold+1 and check if a threshold is crossed. | |
4233 | * If none of thresholds above usage is crossed, we read | |
4234 | * only one element of the array here. | |
4235 | */ | |
4236 | for (; i < t->size && unlikely(t->entries[i].threshold <= usage); i++) | |
4237 | eventfd_signal(t->entries[i].eventfd, 1); | |
4238 | ||
4239 | /* Update current_threshold */ | |
5407a562 | 4240 | t->current_threshold = i - 1; |
2e72b634 KS |
4241 | unlock: |
4242 | rcu_read_unlock(); | |
4243 | } | |
4244 | ||
4245 | static void mem_cgroup_threshold(struct mem_cgroup *memcg) | |
4246 | { | |
ad4ca5f4 KS |
4247 | while (memcg) { |
4248 | __mem_cgroup_threshold(memcg, false); | |
4249 | if (do_swap_account) | |
4250 | __mem_cgroup_threshold(memcg, true); | |
4251 | ||
4252 | memcg = parent_mem_cgroup(memcg); | |
4253 | } | |
2e72b634 KS |
4254 | } |
4255 | ||
4256 | static int compare_thresholds(const void *a, const void *b) | |
4257 | { | |
4258 | const struct mem_cgroup_threshold *_a = a; | |
4259 | const struct mem_cgroup_threshold *_b = b; | |
4260 | ||
2bff24a3 GT |
4261 | if (_a->threshold > _b->threshold) |
4262 | return 1; | |
4263 | ||
4264 | if (_a->threshold < _b->threshold) | |
4265 | return -1; | |
4266 | ||
4267 | return 0; | |
2e72b634 KS |
4268 | } |
4269 | ||
c0ff4b85 | 4270 | static int mem_cgroup_oom_notify_cb(struct mem_cgroup *memcg) |
9490ff27 KH |
4271 | { |
4272 | struct mem_cgroup_eventfd_list *ev; | |
4273 | ||
2bcf2e92 MH |
4274 | spin_lock(&memcg_oom_lock); |
4275 | ||
c0ff4b85 | 4276 | list_for_each_entry(ev, &memcg->oom_notify, list) |
9490ff27 | 4277 | eventfd_signal(ev->eventfd, 1); |
2bcf2e92 MH |
4278 | |
4279 | spin_unlock(&memcg_oom_lock); | |
9490ff27 KH |
4280 | return 0; |
4281 | } | |
4282 | ||
c0ff4b85 | 4283 | static void mem_cgroup_oom_notify(struct mem_cgroup *memcg) |
9490ff27 | 4284 | { |
7d74b06f KH |
4285 | struct mem_cgroup *iter; |
4286 | ||
c0ff4b85 | 4287 | for_each_mem_cgroup_tree(iter, memcg) |
7d74b06f | 4288 | mem_cgroup_oom_notify_cb(iter); |
9490ff27 KH |
4289 | } |
4290 | ||
59b6f873 | 4291 | static int __mem_cgroup_usage_register_event(struct mem_cgroup *memcg, |
347c4a87 | 4292 | struct eventfd_ctx *eventfd, const char *args, enum res_type type) |
2e72b634 | 4293 | { |
2c488db2 KS |
4294 | struct mem_cgroup_thresholds *thresholds; |
4295 | struct mem_cgroup_threshold_ary *new; | |
3e32cb2e JW |
4296 | unsigned long threshold; |
4297 | unsigned long usage; | |
2c488db2 | 4298 | int i, size, ret; |
2e72b634 | 4299 | |
3e32cb2e | 4300 | ret = page_counter_memparse(args, &threshold); |
2e72b634 KS |
4301 | if (ret) |
4302 | return ret; | |
4303 | ||
4304 | mutex_lock(&memcg->thresholds_lock); | |
2c488db2 | 4305 | |
05b84301 | 4306 | if (type == _MEM) { |
2c488db2 | 4307 | thresholds = &memcg->thresholds; |
ce00a967 | 4308 | usage = mem_cgroup_usage(memcg, false); |
05b84301 | 4309 | } else if (type == _MEMSWAP) { |
2c488db2 | 4310 | thresholds = &memcg->memsw_thresholds; |
ce00a967 | 4311 | usage = mem_cgroup_usage(memcg, true); |
05b84301 | 4312 | } else |
2e72b634 KS |
4313 | BUG(); |
4314 | ||
2e72b634 | 4315 | /* Check if a threshold crossed before adding a new one */ |
2c488db2 | 4316 | if (thresholds->primary) |
2e72b634 KS |
4317 | __mem_cgroup_threshold(memcg, type == _MEMSWAP); |
4318 | ||
2c488db2 | 4319 | size = thresholds->primary ? thresholds->primary->size + 1 : 1; |
2e72b634 KS |
4320 | |
4321 | /* Allocate memory for new array of thresholds */ | |
2c488db2 | 4322 | new = kmalloc(sizeof(*new) + size * sizeof(struct mem_cgroup_threshold), |
2e72b634 | 4323 | GFP_KERNEL); |
2c488db2 | 4324 | if (!new) { |
2e72b634 KS |
4325 | ret = -ENOMEM; |
4326 | goto unlock; | |
4327 | } | |
2c488db2 | 4328 | new->size = size; |
2e72b634 KS |
4329 | |
4330 | /* Copy thresholds (if any) to new array */ | |
2c488db2 KS |
4331 | if (thresholds->primary) { |
4332 | memcpy(new->entries, thresholds->primary->entries, (size - 1) * | |
2e72b634 | 4333 | sizeof(struct mem_cgroup_threshold)); |
2c488db2 KS |
4334 | } |
4335 | ||
2e72b634 | 4336 | /* Add new threshold */ |
2c488db2 KS |
4337 | new->entries[size - 1].eventfd = eventfd; |
4338 | new->entries[size - 1].threshold = threshold; | |
2e72b634 KS |
4339 | |
4340 | /* Sort thresholds. Registering of new threshold isn't time-critical */ | |
2c488db2 | 4341 | sort(new->entries, size, sizeof(struct mem_cgroup_threshold), |
2e72b634 KS |
4342 | compare_thresholds, NULL); |
4343 | ||
4344 | /* Find current threshold */ | |
2c488db2 | 4345 | new->current_threshold = -1; |
2e72b634 | 4346 | for (i = 0; i < size; i++) { |
748dad36 | 4347 | if (new->entries[i].threshold <= usage) { |
2e72b634 | 4348 | /* |
2c488db2 KS |
4349 | * new->current_threshold will not be used until |
4350 | * rcu_assign_pointer(), so it's safe to increment | |
2e72b634 KS |
4351 | * it here. |
4352 | */ | |
2c488db2 | 4353 | ++new->current_threshold; |
748dad36 SZ |
4354 | } else |
4355 | break; | |
2e72b634 KS |
4356 | } |
4357 | ||
2c488db2 KS |
4358 | /* Free old spare buffer and save old primary buffer as spare */ |
4359 | kfree(thresholds->spare); | |
4360 | thresholds->spare = thresholds->primary; | |
4361 | ||
4362 | rcu_assign_pointer(thresholds->primary, new); | |
2e72b634 | 4363 | |
907860ed | 4364 | /* To be sure that nobody uses thresholds */ |
2e72b634 KS |
4365 | synchronize_rcu(); |
4366 | ||
2e72b634 KS |
4367 | unlock: |
4368 | mutex_unlock(&memcg->thresholds_lock); | |
4369 | ||
4370 | return ret; | |
4371 | } | |
4372 | ||
59b6f873 | 4373 | static int mem_cgroup_usage_register_event(struct mem_cgroup *memcg, |
347c4a87 TH |
4374 | struct eventfd_ctx *eventfd, const char *args) |
4375 | { | |
59b6f873 | 4376 | return __mem_cgroup_usage_register_event(memcg, eventfd, args, _MEM); |
347c4a87 TH |
4377 | } |
4378 | ||
59b6f873 | 4379 | static int memsw_cgroup_usage_register_event(struct mem_cgroup *memcg, |
347c4a87 TH |
4380 | struct eventfd_ctx *eventfd, const char *args) |
4381 | { | |
59b6f873 | 4382 | return __mem_cgroup_usage_register_event(memcg, eventfd, args, _MEMSWAP); |
347c4a87 TH |
4383 | } |
4384 | ||
59b6f873 | 4385 | static void __mem_cgroup_usage_unregister_event(struct mem_cgroup *memcg, |
347c4a87 | 4386 | struct eventfd_ctx *eventfd, enum res_type type) |
2e72b634 | 4387 | { |
2c488db2 KS |
4388 | struct mem_cgroup_thresholds *thresholds; |
4389 | struct mem_cgroup_threshold_ary *new; | |
3e32cb2e | 4390 | unsigned long usage; |
2c488db2 | 4391 | int i, j, size; |
2e72b634 KS |
4392 | |
4393 | mutex_lock(&memcg->thresholds_lock); | |
05b84301 JW |
4394 | |
4395 | if (type == _MEM) { | |
2c488db2 | 4396 | thresholds = &memcg->thresholds; |
ce00a967 | 4397 | usage = mem_cgroup_usage(memcg, false); |
05b84301 | 4398 | } else if (type == _MEMSWAP) { |
2c488db2 | 4399 | thresholds = &memcg->memsw_thresholds; |
ce00a967 | 4400 | usage = mem_cgroup_usage(memcg, true); |
05b84301 | 4401 | } else |
2e72b634 KS |
4402 | BUG(); |
4403 | ||
371528ca AV |
4404 | if (!thresholds->primary) |
4405 | goto unlock; | |
4406 | ||
2e72b634 KS |
4407 | /* Check if a threshold crossed before removing */ |
4408 | __mem_cgroup_threshold(memcg, type == _MEMSWAP); | |
4409 | ||
4410 | /* Calculate new number of threshold */ | |
2c488db2 KS |
4411 | size = 0; |
4412 | for (i = 0; i < thresholds->primary->size; i++) { | |
4413 | if (thresholds->primary->entries[i].eventfd != eventfd) | |
2e72b634 KS |
4414 | size++; |
4415 | } | |
4416 | ||
2c488db2 | 4417 | new = thresholds->spare; |
907860ed | 4418 | |
2e72b634 KS |
4419 | /* Set thresholds array to NULL if we don't have thresholds */ |
4420 | if (!size) { | |
2c488db2 KS |
4421 | kfree(new); |
4422 | new = NULL; | |
907860ed | 4423 | goto swap_buffers; |
2e72b634 KS |
4424 | } |
4425 | ||
2c488db2 | 4426 | new->size = size; |
2e72b634 KS |
4427 | |
4428 | /* Copy thresholds and find current threshold */ | |
2c488db2 KS |
4429 | new->current_threshold = -1; |
4430 | for (i = 0, j = 0; i < thresholds->primary->size; i++) { | |
4431 | if (thresholds->primary->entries[i].eventfd == eventfd) | |
2e72b634 KS |
4432 | continue; |
4433 | ||
2c488db2 | 4434 | new->entries[j] = thresholds->primary->entries[i]; |
748dad36 | 4435 | if (new->entries[j].threshold <= usage) { |
2e72b634 | 4436 | /* |
2c488db2 | 4437 | * new->current_threshold will not be used |
2e72b634 KS |
4438 | * until rcu_assign_pointer(), so it's safe to increment |
4439 | * it here. | |
4440 | */ | |
2c488db2 | 4441 | ++new->current_threshold; |
2e72b634 KS |
4442 | } |
4443 | j++; | |
4444 | } | |
4445 | ||
907860ed | 4446 | swap_buffers: |
2c488db2 KS |
4447 | /* Swap primary and spare array */ |
4448 | thresholds->spare = thresholds->primary; | |
8c757763 SZ |
4449 | /* If all events are unregistered, free the spare array */ |
4450 | if (!new) { | |
4451 | kfree(thresholds->spare); | |
4452 | thresholds->spare = NULL; | |
4453 | } | |
4454 | ||
2c488db2 | 4455 | rcu_assign_pointer(thresholds->primary, new); |
2e72b634 | 4456 | |
907860ed | 4457 | /* To be sure that nobody uses thresholds */ |
2e72b634 | 4458 | synchronize_rcu(); |
371528ca | 4459 | unlock: |
2e72b634 | 4460 | mutex_unlock(&memcg->thresholds_lock); |
2e72b634 | 4461 | } |
c1e862c1 | 4462 | |
59b6f873 | 4463 | static void mem_cgroup_usage_unregister_event(struct mem_cgroup *memcg, |
347c4a87 TH |
4464 | struct eventfd_ctx *eventfd) |
4465 | { | |
59b6f873 | 4466 | return __mem_cgroup_usage_unregister_event(memcg, eventfd, _MEM); |
347c4a87 TH |
4467 | } |
4468 | ||
59b6f873 | 4469 | static void memsw_cgroup_usage_unregister_event(struct mem_cgroup *memcg, |
347c4a87 TH |
4470 | struct eventfd_ctx *eventfd) |
4471 | { | |
59b6f873 | 4472 | return __mem_cgroup_usage_unregister_event(memcg, eventfd, _MEMSWAP); |
347c4a87 TH |
4473 | } |
4474 | ||
59b6f873 | 4475 | static int mem_cgroup_oom_register_event(struct mem_cgroup *memcg, |
347c4a87 | 4476 | struct eventfd_ctx *eventfd, const char *args) |
9490ff27 | 4477 | { |
9490ff27 | 4478 | struct mem_cgroup_eventfd_list *event; |
9490ff27 | 4479 | |
9490ff27 KH |
4480 | event = kmalloc(sizeof(*event), GFP_KERNEL); |
4481 | if (!event) | |
4482 | return -ENOMEM; | |
4483 | ||
1af8efe9 | 4484 | spin_lock(&memcg_oom_lock); |
9490ff27 KH |
4485 | |
4486 | event->eventfd = eventfd; | |
4487 | list_add(&event->list, &memcg->oom_notify); | |
4488 | ||
4489 | /* already in OOM ? */ | |
79dfdacc | 4490 | if (atomic_read(&memcg->under_oom)) |
9490ff27 | 4491 | eventfd_signal(eventfd, 1); |
1af8efe9 | 4492 | spin_unlock(&memcg_oom_lock); |
9490ff27 KH |
4493 | |
4494 | return 0; | |
4495 | } | |
4496 | ||
59b6f873 | 4497 | static void mem_cgroup_oom_unregister_event(struct mem_cgroup *memcg, |
347c4a87 | 4498 | struct eventfd_ctx *eventfd) |
9490ff27 | 4499 | { |
9490ff27 | 4500 | struct mem_cgroup_eventfd_list *ev, *tmp; |
9490ff27 | 4501 | |
1af8efe9 | 4502 | spin_lock(&memcg_oom_lock); |
9490ff27 | 4503 | |
c0ff4b85 | 4504 | list_for_each_entry_safe(ev, tmp, &memcg->oom_notify, list) { |
9490ff27 KH |
4505 | if (ev->eventfd == eventfd) { |
4506 | list_del(&ev->list); | |
4507 | kfree(ev); | |
4508 | } | |
4509 | } | |
4510 | ||
1af8efe9 | 4511 | spin_unlock(&memcg_oom_lock); |
9490ff27 KH |
4512 | } |
4513 | ||
2da8ca82 | 4514 | static int mem_cgroup_oom_control_read(struct seq_file *sf, void *v) |
3c11ecf4 | 4515 | { |
2da8ca82 | 4516 | struct mem_cgroup *memcg = mem_cgroup_from_css(seq_css(sf)); |
3c11ecf4 | 4517 | |
791badbd TH |
4518 | seq_printf(sf, "oom_kill_disable %d\n", memcg->oom_kill_disable); |
4519 | seq_printf(sf, "under_oom %d\n", (bool)atomic_read(&memcg->under_oom)); | |
3c11ecf4 KH |
4520 | return 0; |
4521 | } | |
4522 | ||
182446d0 | 4523 | static int mem_cgroup_oom_control_write(struct cgroup_subsys_state *css, |
3c11ecf4 KH |
4524 | struct cftype *cft, u64 val) |
4525 | { | |
182446d0 | 4526 | struct mem_cgroup *memcg = mem_cgroup_from_css(css); |
3c11ecf4 KH |
4527 | |
4528 | /* cannot set to root cgroup and only 0 and 1 are allowed */ | |
14208b0e | 4529 | if (!css->parent || !((val == 0) || (val == 1))) |
3c11ecf4 KH |
4530 | return -EINVAL; |
4531 | ||
c0ff4b85 | 4532 | memcg->oom_kill_disable = val; |
4d845ebf | 4533 | if (!val) |
c0ff4b85 | 4534 | memcg_oom_recover(memcg); |
3dae7fec | 4535 | |
3c11ecf4 KH |
4536 | return 0; |
4537 | } | |
4538 | ||
c255a458 | 4539 | #ifdef CONFIG_MEMCG_KMEM |
cbe128e3 | 4540 | static int memcg_init_kmem(struct mem_cgroup *memcg, struct cgroup_subsys *ss) |
e5671dfa | 4541 | { |
55007d84 GC |
4542 | int ret; |
4543 | ||
2633d7a0 | 4544 | memcg->kmemcg_id = -1; |
55007d84 GC |
4545 | ret = memcg_propagate_kmem(memcg); |
4546 | if (ret) | |
4547 | return ret; | |
2633d7a0 | 4548 | |
1d62e436 | 4549 | return mem_cgroup_sockets_init(memcg, ss); |
573b400d | 4550 | } |
e5671dfa | 4551 | |
10d5ebf4 | 4552 | static void memcg_destroy_kmem(struct mem_cgroup *memcg) |
d1a4c0b3 | 4553 | { |
1d62e436 | 4554 | mem_cgroup_sockets_destroy(memcg); |
10d5ebf4 | 4555 | } |
e5671dfa | 4556 | #else |
cbe128e3 | 4557 | static int memcg_init_kmem(struct mem_cgroup *memcg, struct cgroup_subsys *ss) |
e5671dfa GC |
4558 | { |
4559 | return 0; | |
4560 | } | |
d1a4c0b3 | 4561 | |
10d5ebf4 LZ |
4562 | static void memcg_destroy_kmem(struct mem_cgroup *memcg) |
4563 | { | |
4564 | } | |
e5671dfa GC |
4565 | #endif |
4566 | ||
3bc942f3 TH |
4567 | /* |
4568 | * DO NOT USE IN NEW FILES. | |
4569 | * | |
4570 | * "cgroup.event_control" implementation. | |
4571 | * | |
4572 | * This is way over-engineered. It tries to support fully configurable | |
4573 | * events for each user. Such level of flexibility is completely | |
4574 | * unnecessary especially in the light of the planned unified hierarchy. | |
4575 | * | |
4576 | * Please deprecate this and replace with something simpler if at all | |
4577 | * possible. | |
4578 | */ | |
4579 | ||
79bd9814 TH |
4580 | /* |
4581 | * Unregister event and free resources. | |
4582 | * | |
4583 | * Gets called from workqueue. | |
4584 | */ | |
3bc942f3 | 4585 | static void memcg_event_remove(struct work_struct *work) |
79bd9814 | 4586 | { |
3bc942f3 TH |
4587 | struct mem_cgroup_event *event = |
4588 | container_of(work, struct mem_cgroup_event, remove); | |
59b6f873 | 4589 | struct mem_cgroup *memcg = event->memcg; |
79bd9814 TH |
4590 | |
4591 | remove_wait_queue(event->wqh, &event->wait); | |
4592 | ||
59b6f873 | 4593 | event->unregister_event(memcg, event->eventfd); |
79bd9814 TH |
4594 | |
4595 | /* Notify userspace the event is going away. */ | |
4596 | eventfd_signal(event->eventfd, 1); | |
4597 | ||
4598 | eventfd_ctx_put(event->eventfd); | |
4599 | kfree(event); | |
59b6f873 | 4600 | css_put(&memcg->css); |
79bd9814 TH |
4601 | } |
4602 | ||
4603 | /* | |
4604 | * Gets called on POLLHUP on eventfd when user closes it. | |
4605 | * | |
4606 | * Called with wqh->lock held and interrupts disabled. | |
4607 | */ | |
3bc942f3 TH |
4608 | static int memcg_event_wake(wait_queue_t *wait, unsigned mode, |
4609 | int sync, void *key) | |
79bd9814 | 4610 | { |
3bc942f3 TH |
4611 | struct mem_cgroup_event *event = |
4612 | container_of(wait, struct mem_cgroup_event, wait); | |
59b6f873 | 4613 | struct mem_cgroup *memcg = event->memcg; |
79bd9814 TH |
4614 | unsigned long flags = (unsigned long)key; |
4615 | ||
4616 | if (flags & POLLHUP) { | |
4617 | /* | |
4618 | * If the event has been detached at cgroup removal, we | |
4619 | * can simply return knowing the other side will cleanup | |
4620 | * for us. | |
4621 | * | |
4622 | * We can't race against event freeing since the other | |
4623 | * side will require wqh->lock via remove_wait_queue(), | |
4624 | * which we hold. | |
4625 | */ | |
fba94807 | 4626 | spin_lock(&memcg->event_list_lock); |
79bd9814 TH |
4627 | if (!list_empty(&event->list)) { |
4628 | list_del_init(&event->list); | |
4629 | /* | |
4630 | * We are in atomic context, but cgroup_event_remove() | |
4631 | * may sleep, so we have to call it in workqueue. | |
4632 | */ | |
4633 | schedule_work(&event->remove); | |
4634 | } | |
fba94807 | 4635 | spin_unlock(&memcg->event_list_lock); |
79bd9814 TH |
4636 | } |
4637 | ||
4638 | return 0; | |
4639 | } | |
4640 | ||
3bc942f3 | 4641 | static void memcg_event_ptable_queue_proc(struct file *file, |
79bd9814 TH |
4642 | wait_queue_head_t *wqh, poll_table *pt) |
4643 | { | |
3bc942f3 TH |
4644 | struct mem_cgroup_event *event = |
4645 | container_of(pt, struct mem_cgroup_event, pt); | |
79bd9814 TH |
4646 | |
4647 | event->wqh = wqh; | |
4648 | add_wait_queue(wqh, &event->wait); | |
4649 | } | |
4650 | ||
4651 | /* | |
3bc942f3 TH |
4652 | * DO NOT USE IN NEW FILES. |
4653 | * | |
79bd9814 TH |
4654 | * Parse input and register new cgroup event handler. |
4655 | * | |
4656 | * Input must be in format '<event_fd> <control_fd> <args>'. | |
4657 | * Interpretation of args is defined by control file implementation. | |
4658 | */ | |
451af504 TH |
4659 | static ssize_t memcg_write_event_control(struct kernfs_open_file *of, |
4660 | char *buf, size_t nbytes, loff_t off) | |
79bd9814 | 4661 | { |
451af504 | 4662 | struct cgroup_subsys_state *css = of_css(of); |
fba94807 | 4663 | struct mem_cgroup *memcg = mem_cgroup_from_css(css); |
3bc942f3 | 4664 | struct mem_cgroup_event *event; |
79bd9814 TH |
4665 | struct cgroup_subsys_state *cfile_css; |
4666 | unsigned int efd, cfd; | |
4667 | struct fd efile; | |
4668 | struct fd cfile; | |
fba94807 | 4669 | const char *name; |
79bd9814 TH |
4670 | char *endp; |
4671 | int ret; | |
4672 | ||
451af504 TH |
4673 | buf = strstrip(buf); |
4674 | ||
4675 | efd = simple_strtoul(buf, &endp, 10); | |
79bd9814 TH |
4676 | if (*endp != ' ') |
4677 | return -EINVAL; | |
451af504 | 4678 | buf = endp + 1; |
79bd9814 | 4679 | |
451af504 | 4680 | cfd = simple_strtoul(buf, &endp, 10); |
79bd9814 TH |
4681 | if ((*endp != ' ') && (*endp != '\0')) |
4682 | return -EINVAL; | |
451af504 | 4683 | buf = endp + 1; |
79bd9814 TH |
4684 | |
4685 | event = kzalloc(sizeof(*event), GFP_KERNEL); | |
4686 | if (!event) | |
4687 | return -ENOMEM; | |
4688 | ||
59b6f873 | 4689 | event->memcg = memcg; |
79bd9814 | 4690 | INIT_LIST_HEAD(&event->list); |
3bc942f3 TH |
4691 | init_poll_funcptr(&event->pt, memcg_event_ptable_queue_proc); |
4692 | init_waitqueue_func_entry(&event->wait, memcg_event_wake); | |
4693 | INIT_WORK(&event->remove, memcg_event_remove); | |
79bd9814 TH |
4694 | |
4695 | efile = fdget(efd); | |
4696 | if (!efile.file) { | |
4697 | ret = -EBADF; | |
4698 | goto out_kfree; | |
4699 | } | |
4700 | ||
4701 | event->eventfd = eventfd_ctx_fileget(efile.file); | |
4702 | if (IS_ERR(event->eventfd)) { | |
4703 | ret = PTR_ERR(event->eventfd); | |
4704 | goto out_put_efile; | |
4705 | } | |
4706 | ||
4707 | cfile = fdget(cfd); | |
4708 | if (!cfile.file) { | |
4709 | ret = -EBADF; | |
4710 | goto out_put_eventfd; | |
4711 | } | |
4712 | ||
4713 | /* the process need read permission on control file */ | |
4714 | /* AV: shouldn't we check that it's been opened for read instead? */ | |
4715 | ret = inode_permission(file_inode(cfile.file), MAY_READ); | |
4716 | if (ret < 0) | |
4717 | goto out_put_cfile; | |
4718 | ||
fba94807 TH |
4719 | /* |
4720 | * Determine the event callbacks and set them in @event. This used | |
4721 | * to be done via struct cftype but cgroup core no longer knows | |
4722 | * about these events. The following is crude but the whole thing | |
4723 | * is for compatibility anyway. | |
3bc942f3 TH |
4724 | * |
4725 | * DO NOT ADD NEW FILES. | |
fba94807 TH |
4726 | */ |
4727 | name = cfile.file->f_dentry->d_name.name; | |
4728 | ||
4729 | if (!strcmp(name, "memory.usage_in_bytes")) { | |
4730 | event->register_event = mem_cgroup_usage_register_event; | |
4731 | event->unregister_event = mem_cgroup_usage_unregister_event; | |
4732 | } else if (!strcmp(name, "memory.oom_control")) { | |
4733 | event->register_event = mem_cgroup_oom_register_event; | |
4734 | event->unregister_event = mem_cgroup_oom_unregister_event; | |
4735 | } else if (!strcmp(name, "memory.pressure_level")) { | |
4736 | event->register_event = vmpressure_register_event; | |
4737 | event->unregister_event = vmpressure_unregister_event; | |
4738 | } else if (!strcmp(name, "memory.memsw.usage_in_bytes")) { | |
347c4a87 TH |
4739 | event->register_event = memsw_cgroup_usage_register_event; |
4740 | event->unregister_event = memsw_cgroup_usage_unregister_event; | |
fba94807 TH |
4741 | } else { |
4742 | ret = -EINVAL; | |
4743 | goto out_put_cfile; | |
4744 | } | |
4745 | ||
79bd9814 | 4746 | /* |
b5557c4c TH |
4747 | * Verify @cfile should belong to @css. Also, remaining events are |
4748 | * automatically removed on cgroup destruction but the removal is | |
4749 | * asynchronous, so take an extra ref on @css. | |
79bd9814 | 4750 | */ |
ec903c0c TH |
4751 | cfile_css = css_tryget_online_from_dir(cfile.file->f_dentry->d_parent, |
4752 | &memory_cgrp_subsys); | |
79bd9814 | 4753 | ret = -EINVAL; |
5a17f543 | 4754 | if (IS_ERR(cfile_css)) |
79bd9814 | 4755 | goto out_put_cfile; |
5a17f543 TH |
4756 | if (cfile_css != css) { |
4757 | css_put(cfile_css); | |
79bd9814 | 4758 | goto out_put_cfile; |
5a17f543 | 4759 | } |
79bd9814 | 4760 | |
451af504 | 4761 | ret = event->register_event(memcg, event->eventfd, buf); |
79bd9814 TH |
4762 | if (ret) |
4763 | goto out_put_css; | |
4764 | ||
4765 | efile.file->f_op->poll(efile.file, &event->pt); | |
4766 | ||
fba94807 TH |
4767 | spin_lock(&memcg->event_list_lock); |
4768 | list_add(&event->list, &memcg->event_list); | |
4769 | spin_unlock(&memcg->event_list_lock); | |
79bd9814 TH |
4770 | |
4771 | fdput(cfile); | |
4772 | fdput(efile); | |
4773 | ||
451af504 | 4774 | return nbytes; |
79bd9814 TH |
4775 | |
4776 | out_put_css: | |
b5557c4c | 4777 | css_put(css); |
79bd9814 TH |
4778 | out_put_cfile: |
4779 | fdput(cfile); | |
4780 | out_put_eventfd: | |
4781 | eventfd_ctx_put(event->eventfd); | |
4782 | out_put_efile: | |
4783 | fdput(efile); | |
4784 | out_kfree: | |
4785 | kfree(event); | |
4786 | ||
4787 | return ret; | |
4788 | } | |
4789 | ||
8cdea7c0 BS |
4790 | static struct cftype mem_cgroup_files[] = { |
4791 | { | |
0eea1030 | 4792 | .name = "usage_in_bytes", |
8c7c6e34 | 4793 | .private = MEMFILE_PRIVATE(_MEM, RES_USAGE), |
791badbd | 4794 | .read_u64 = mem_cgroup_read_u64, |
8cdea7c0 | 4795 | }, |
c84872e1 PE |
4796 | { |
4797 | .name = "max_usage_in_bytes", | |
8c7c6e34 | 4798 | .private = MEMFILE_PRIVATE(_MEM, RES_MAX_USAGE), |
6770c64e | 4799 | .write = mem_cgroup_reset, |
791badbd | 4800 | .read_u64 = mem_cgroup_read_u64, |
c84872e1 | 4801 | }, |
8cdea7c0 | 4802 | { |
0eea1030 | 4803 | .name = "limit_in_bytes", |
8c7c6e34 | 4804 | .private = MEMFILE_PRIVATE(_MEM, RES_LIMIT), |
451af504 | 4805 | .write = mem_cgroup_write, |
791badbd | 4806 | .read_u64 = mem_cgroup_read_u64, |
8cdea7c0 | 4807 | }, |
296c81d8 BS |
4808 | { |
4809 | .name = "soft_limit_in_bytes", | |
4810 | .private = MEMFILE_PRIVATE(_MEM, RES_SOFT_LIMIT), | |
451af504 | 4811 | .write = mem_cgroup_write, |
791badbd | 4812 | .read_u64 = mem_cgroup_read_u64, |
296c81d8 | 4813 | }, |
8cdea7c0 BS |
4814 | { |
4815 | .name = "failcnt", | |
8c7c6e34 | 4816 | .private = MEMFILE_PRIVATE(_MEM, RES_FAILCNT), |
6770c64e | 4817 | .write = mem_cgroup_reset, |
791badbd | 4818 | .read_u64 = mem_cgroup_read_u64, |
8cdea7c0 | 4819 | }, |
d2ceb9b7 KH |
4820 | { |
4821 | .name = "stat", | |
2da8ca82 | 4822 | .seq_show = memcg_stat_show, |
d2ceb9b7 | 4823 | }, |
c1e862c1 KH |
4824 | { |
4825 | .name = "force_empty", | |
6770c64e | 4826 | .write = mem_cgroup_force_empty_write, |
c1e862c1 | 4827 | }, |
18f59ea7 BS |
4828 | { |
4829 | .name = "use_hierarchy", | |
4830 | .write_u64 = mem_cgroup_hierarchy_write, | |
4831 | .read_u64 = mem_cgroup_hierarchy_read, | |
4832 | }, | |
79bd9814 | 4833 | { |
3bc942f3 | 4834 | .name = "cgroup.event_control", /* XXX: for compat */ |
451af504 | 4835 | .write = memcg_write_event_control, |
79bd9814 TH |
4836 | .flags = CFTYPE_NO_PREFIX, |
4837 | .mode = S_IWUGO, | |
4838 | }, | |
a7885eb8 KM |
4839 | { |
4840 | .name = "swappiness", | |
4841 | .read_u64 = mem_cgroup_swappiness_read, | |
4842 | .write_u64 = mem_cgroup_swappiness_write, | |
4843 | }, | |
7dc74be0 DN |
4844 | { |
4845 | .name = "move_charge_at_immigrate", | |
4846 | .read_u64 = mem_cgroup_move_charge_read, | |
4847 | .write_u64 = mem_cgroup_move_charge_write, | |
4848 | }, | |
9490ff27 KH |
4849 | { |
4850 | .name = "oom_control", | |
2da8ca82 | 4851 | .seq_show = mem_cgroup_oom_control_read, |
3c11ecf4 | 4852 | .write_u64 = mem_cgroup_oom_control_write, |
9490ff27 KH |
4853 | .private = MEMFILE_PRIVATE(_OOM_TYPE, OOM_CONTROL), |
4854 | }, | |
70ddf637 AV |
4855 | { |
4856 | .name = "pressure_level", | |
70ddf637 | 4857 | }, |
406eb0c9 YH |
4858 | #ifdef CONFIG_NUMA |
4859 | { | |
4860 | .name = "numa_stat", | |
2da8ca82 | 4861 | .seq_show = memcg_numa_stat_show, |
406eb0c9 YH |
4862 | }, |
4863 | #endif | |
510fc4e1 GC |
4864 | #ifdef CONFIG_MEMCG_KMEM |
4865 | { | |
4866 | .name = "kmem.limit_in_bytes", | |
4867 | .private = MEMFILE_PRIVATE(_KMEM, RES_LIMIT), | |
451af504 | 4868 | .write = mem_cgroup_write, |
791badbd | 4869 | .read_u64 = mem_cgroup_read_u64, |
510fc4e1 GC |
4870 | }, |
4871 | { | |
4872 | .name = "kmem.usage_in_bytes", | |
4873 | .private = MEMFILE_PRIVATE(_KMEM, RES_USAGE), | |
791badbd | 4874 | .read_u64 = mem_cgroup_read_u64, |
510fc4e1 GC |
4875 | }, |
4876 | { | |
4877 | .name = "kmem.failcnt", | |
4878 | .private = MEMFILE_PRIVATE(_KMEM, RES_FAILCNT), | |
6770c64e | 4879 | .write = mem_cgroup_reset, |
791badbd | 4880 | .read_u64 = mem_cgroup_read_u64, |
510fc4e1 GC |
4881 | }, |
4882 | { | |
4883 | .name = "kmem.max_usage_in_bytes", | |
4884 | .private = MEMFILE_PRIVATE(_KMEM, RES_MAX_USAGE), | |
6770c64e | 4885 | .write = mem_cgroup_reset, |
791badbd | 4886 | .read_u64 = mem_cgroup_read_u64, |
510fc4e1 | 4887 | }, |
749c5415 GC |
4888 | #ifdef CONFIG_SLABINFO |
4889 | { | |
4890 | .name = "kmem.slabinfo", | |
2da8ca82 | 4891 | .seq_show = mem_cgroup_slabinfo_read, |
749c5415 GC |
4892 | }, |
4893 | #endif | |
8c7c6e34 | 4894 | #endif |
6bc10349 | 4895 | { }, /* terminate */ |
af36f906 | 4896 | }; |
8c7c6e34 | 4897 | |
2d11085e MH |
4898 | #ifdef CONFIG_MEMCG_SWAP |
4899 | static struct cftype memsw_cgroup_files[] = { | |
4900 | { | |
4901 | .name = "memsw.usage_in_bytes", | |
4902 | .private = MEMFILE_PRIVATE(_MEMSWAP, RES_USAGE), | |
791badbd | 4903 | .read_u64 = mem_cgroup_read_u64, |
2d11085e MH |
4904 | }, |
4905 | { | |
4906 | .name = "memsw.max_usage_in_bytes", | |
4907 | .private = MEMFILE_PRIVATE(_MEMSWAP, RES_MAX_USAGE), | |
6770c64e | 4908 | .write = mem_cgroup_reset, |
791badbd | 4909 | .read_u64 = mem_cgroup_read_u64, |
2d11085e MH |
4910 | }, |
4911 | { | |
4912 | .name = "memsw.limit_in_bytes", | |
4913 | .private = MEMFILE_PRIVATE(_MEMSWAP, RES_LIMIT), | |
451af504 | 4914 | .write = mem_cgroup_write, |
791badbd | 4915 | .read_u64 = mem_cgroup_read_u64, |
2d11085e MH |
4916 | }, |
4917 | { | |
4918 | .name = "memsw.failcnt", | |
4919 | .private = MEMFILE_PRIVATE(_MEMSWAP, RES_FAILCNT), | |
6770c64e | 4920 | .write = mem_cgroup_reset, |
791badbd | 4921 | .read_u64 = mem_cgroup_read_u64, |
2d11085e MH |
4922 | }, |
4923 | { }, /* terminate */ | |
4924 | }; | |
4925 | #endif | |
c0ff4b85 | 4926 | static int alloc_mem_cgroup_per_zone_info(struct mem_cgroup *memcg, int node) |
6d12e2d8 KH |
4927 | { |
4928 | struct mem_cgroup_per_node *pn; | |
1ecaab2b | 4929 | struct mem_cgroup_per_zone *mz; |
41e3355d | 4930 | int zone, tmp = node; |
1ecaab2b KH |
4931 | /* |
4932 | * This routine is called against possible nodes. | |
4933 | * But it's BUG to call kmalloc() against offline node. | |
4934 | * | |
4935 | * TODO: this routine can waste much memory for nodes which will | |
4936 | * never be onlined. It's better to use memory hotplug callback | |
4937 | * function. | |
4938 | */ | |
41e3355d KH |
4939 | if (!node_state(node, N_NORMAL_MEMORY)) |
4940 | tmp = -1; | |
17295c88 | 4941 | pn = kzalloc_node(sizeof(*pn), GFP_KERNEL, tmp); |
6d12e2d8 KH |
4942 | if (!pn) |
4943 | return 1; | |
1ecaab2b | 4944 | |
1ecaab2b KH |
4945 | for (zone = 0; zone < MAX_NR_ZONES; zone++) { |
4946 | mz = &pn->zoneinfo[zone]; | |
bea8c150 | 4947 | lruvec_init(&mz->lruvec); |
bb4cc1a8 AM |
4948 | mz->usage_in_excess = 0; |
4949 | mz->on_tree = false; | |
d79154bb | 4950 | mz->memcg = memcg; |
1ecaab2b | 4951 | } |
54f72fe0 | 4952 | memcg->nodeinfo[node] = pn; |
6d12e2d8 KH |
4953 | return 0; |
4954 | } | |
4955 | ||
c0ff4b85 | 4956 | static void free_mem_cgroup_per_zone_info(struct mem_cgroup *memcg, int node) |
1ecaab2b | 4957 | { |
54f72fe0 | 4958 | kfree(memcg->nodeinfo[node]); |
1ecaab2b KH |
4959 | } |
4960 | ||
33327948 KH |
4961 | static struct mem_cgroup *mem_cgroup_alloc(void) |
4962 | { | |
d79154bb | 4963 | struct mem_cgroup *memcg; |
8ff69e2c | 4964 | size_t size; |
33327948 | 4965 | |
8ff69e2c VD |
4966 | size = sizeof(struct mem_cgroup); |
4967 | size += nr_node_ids * sizeof(struct mem_cgroup_per_node *); | |
33327948 | 4968 | |
8ff69e2c | 4969 | memcg = kzalloc(size, GFP_KERNEL); |
d79154bb | 4970 | if (!memcg) |
e7bbcdf3 DC |
4971 | return NULL; |
4972 | ||
d79154bb HD |
4973 | memcg->stat = alloc_percpu(struct mem_cgroup_stat_cpu); |
4974 | if (!memcg->stat) | |
d2e61b8d | 4975 | goto out_free; |
d79154bb HD |
4976 | spin_lock_init(&memcg->pcp_counter_lock); |
4977 | return memcg; | |
d2e61b8d DC |
4978 | |
4979 | out_free: | |
8ff69e2c | 4980 | kfree(memcg); |
d2e61b8d | 4981 | return NULL; |
33327948 KH |
4982 | } |
4983 | ||
59927fb9 | 4984 | /* |
c8b2a36f GC |
4985 | * At destroying mem_cgroup, references from swap_cgroup can remain. |
4986 | * (scanning all at force_empty is too costly...) | |
4987 | * | |
4988 | * Instead of clearing all references at force_empty, we remember | |
4989 | * the number of reference from swap_cgroup and free mem_cgroup when | |
4990 | * it goes down to 0. | |
4991 | * | |
4992 | * Removal of cgroup itself succeeds regardless of refs from swap. | |
59927fb9 | 4993 | */ |
c8b2a36f GC |
4994 | |
4995 | static void __mem_cgroup_free(struct mem_cgroup *memcg) | |
59927fb9 | 4996 | { |
c8b2a36f | 4997 | int node; |
59927fb9 | 4998 | |
bb4cc1a8 | 4999 | mem_cgroup_remove_from_trees(memcg); |
c8b2a36f GC |
5000 | |
5001 | for_each_node(node) | |
5002 | free_mem_cgroup_per_zone_info(memcg, node); | |
5003 | ||
5004 | free_percpu(memcg->stat); | |
5005 | ||
3f134619 GC |
5006 | /* |
5007 | * We need to make sure that (at least for now), the jump label | |
5008 | * destruction code runs outside of the cgroup lock. This is because | |
5009 | * get_online_cpus(), which is called from the static_branch update, | |
5010 | * can't be called inside the cgroup_lock. cpusets are the ones | |
5011 | * enforcing this dependency, so if they ever change, we might as well. | |
5012 | * | |
5013 | * schedule_work() will guarantee this happens. Be careful if you need | |
5014 | * to move this code around, and make sure it is outside | |
5015 | * the cgroup_lock. | |
5016 | */ | |
a8964b9b | 5017 | disarm_static_keys(memcg); |
8ff69e2c | 5018 | kfree(memcg); |
59927fb9 | 5019 | } |
3afe36b1 | 5020 | |
7bcc1bb1 DN |
5021 | /* |
5022 | * Returns the parent mem_cgroup in memcgroup hierarchy with hierarchy enabled. | |
5023 | */ | |
e1aab161 | 5024 | struct mem_cgroup *parent_mem_cgroup(struct mem_cgroup *memcg) |
7bcc1bb1 | 5025 | { |
3e32cb2e | 5026 | if (!memcg->memory.parent) |
7bcc1bb1 | 5027 | return NULL; |
3e32cb2e | 5028 | return mem_cgroup_from_counter(memcg->memory.parent, memory); |
7bcc1bb1 | 5029 | } |
e1aab161 | 5030 | EXPORT_SYMBOL(parent_mem_cgroup); |
33327948 | 5031 | |
bb4cc1a8 AM |
5032 | static void __init mem_cgroup_soft_limit_tree_init(void) |
5033 | { | |
5034 | struct mem_cgroup_tree_per_node *rtpn; | |
5035 | struct mem_cgroup_tree_per_zone *rtpz; | |
5036 | int tmp, node, zone; | |
5037 | ||
5038 | for_each_node(node) { | |
5039 | tmp = node; | |
5040 | if (!node_state(node, N_NORMAL_MEMORY)) | |
5041 | tmp = -1; | |
5042 | rtpn = kzalloc_node(sizeof(*rtpn), GFP_KERNEL, tmp); | |
5043 | BUG_ON(!rtpn); | |
5044 | ||
5045 | soft_limit_tree.rb_tree_per_node[node] = rtpn; | |
5046 | ||
5047 | for (zone = 0; zone < MAX_NR_ZONES; zone++) { | |
5048 | rtpz = &rtpn->rb_tree_per_zone[zone]; | |
5049 | rtpz->rb_root = RB_ROOT; | |
5050 | spin_lock_init(&rtpz->lock); | |
5051 | } | |
5052 | } | |
5053 | } | |
5054 | ||
0eb253e2 | 5055 | static struct cgroup_subsys_state * __ref |
eb95419b | 5056 | mem_cgroup_css_alloc(struct cgroup_subsys_state *parent_css) |
8cdea7c0 | 5057 | { |
d142e3e6 | 5058 | struct mem_cgroup *memcg; |
04046e1a | 5059 | long error = -ENOMEM; |
6d12e2d8 | 5060 | int node; |
8cdea7c0 | 5061 | |
c0ff4b85 R |
5062 | memcg = mem_cgroup_alloc(); |
5063 | if (!memcg) | |
04046e1a | 5064 | return ERR_PTR(error); |
78fb7466 | 5065 | |
3ed28fa1 | 5066 | for_each_node(node) |
c0ff4b85 | 5067 | if (alloc_mem_cgroup_per_zone_info(memcg, node)) |
6d12e2d8 | 5068 | goto free_out; |
f64c3f54 | 5069 | |
c077719b | 5070 | /* root ? */ |
eb95419b | 5071 | if (parent_css == NULL) { |
a41c58a6 | 5072 | root_mem_cgroup = memcg; |
3e32cb2e JW |
5073 | page_counter_init(&memcg->memory, NULL); |
5074 | page_counter_init(&memcg->memsw, NULL); | |
5075 | page_counter_init(&memcg->kmem, NULL); | |
18f59ea7 | 5076 | } |
28dbc4b6 | 5077 | |
d142e3e6 GC |
5078 | memcg->last_scanned_node = MAX_NUMNODES; |
5079 | INIT_LIST_HEAD(&memcg->oom_notify); | |
d142e3e6 GC |
5080 | memcg->move_charge_at_immigrate = 0; |
5081 | mutex_init(&memcg->thresholds_lock); | |
5082 | spin_lock_init(&memcg->move_lock); | |
70ddf637 | 5083 | vmpressure_init(&memcg->vmpressure); |
fba94807 TH |
5084 | INIT_LIST_HEAD(&memcg->event_list); |
5085 | spin_lock_init(&memcg->event_list_lock); | |
d142e3e6 GC |
5086 | |
5087 | return &memcg->css; | |
5088 | ||
5089 | free_out: | |
5090 | __mem_cgroup_free(memcg); | |
5091 | return ERR_PTR(error); | |
5092 | } | |
5093 | ||
5094 | static int | |
eb95419b | 5095 | mem_cgroup_css_online(struct cgroup_subsys_state *css) |
d142e3e6 | 5096 | { |
eb95419b | 5097 | struct mem_cgroup *memcg = mem_cgroup_from_css(css); |
5c9d535b | 5098 | struct mem_cgroup *parent = mem_cgroup_from_css(css->parent); |
2f7dd7a4 | 5099 | int ret; |
d142e3e6 | 5100 | |
15a4c835 | 5101 | if (css->id > MEM_CGROUP_ID_MAX) |
4219b2da LZ |
5102 | return -ENOSPC; |
5103 | ||
63876986 | 5104 | if (!parent) |
d142e3e6 GC |
5105 | return 0; |
5106 | ||
0999821b | 5107 | mutex_lock(&memcg_create_mutex); |
d142e3e6 GC |
5108 | |
5109 | memcg->use_hierarchy = parent->use_hierarchy; | |
5110 | memcg->oom_kill_disable = parent->oom_kill_disable; | |
5111 | memcg->swappiness = mem_cgroup_swappiness(parent); | |
5112 | ||
5113 | if (parent->use_hierarchy) { | |
3e32cb2e JW |
5114 | page_counter_init(&memcg->memory, &parent->memory); |
5115 | page_counter_init(&memcg->memsw, &parent->memsw); | |
5116 | page_counter_init(&memcg->kmem, &parent->kmem); | |
55007d84 | 5117 | |
7bcc1bb1 | 5118 | /* |
8d76a979 LZ |
5119 | * No need to take a reference to the parent because cgroup |
5120 | * core guarantees its existence. | |
7bcc1bb1 | 5121 | */ |
18f59ea7 | 5122 | } else { |
3e32cb2e JW |
5123 | page_counter_init(&memcg->memory, NULL); |
5124 | page_counter_init(&memcg->memsw, NULL); | |
5125 | page_counter_init(&memcg->kmem, NULL); | |
8c7f6edb TH |
5126 | /* |
5127 | * Deeper hierachy with use_hierarchy == false doesn't make | |
5128 | * much sense so let cgroup subsystem know about this | |
5129 | * unfortunate state in our controller. | |
5130 | */ | |
d142e3e6 | 5131 | if (parent != root_mem_cgroup) |
073219e9 | 5132 | memory_cgrp_subsys.broken_hierarchy = true; |
18f59ea7 | 5133 | } |
0999821b | 5134 | mutex_unlock(&memcg_create_mutex); |
d6441637 | 5135 | |
2f7dd7a4 JW |
5136 | ret = memcg_init_kmem(memcg, &memory_cgrp_subsys); |
5137 | if (ret) | |
5138 | return ret; | |
5139 | ||
5140 | /* | |
5141 | * Make sure the memcg is initialized: mem_cgroup_iter() | |
5142 | * orders reading memcg->initialized against its callers | |
5143 | * reading the memcg members. | |
5144 | */ | |
5145 | smp_store_release(&memcg->initialized, 1); | |
5146 | ||
5147 | return 0; | |
8cdea7c0 BS |
5148 | } |
5149 | ||
eb95419b | 5150 | static void mem_cgroup_css_offline(struct cgroup_subsys_state *css) |
df878fb0 | 5151 | { |
eb95419b | 5152 | struct mem_cgroup *memcg = mem_cgroup_from_css(css); |
3bc942f3 | 5153 | struct mem_cgroup_event *event, *tmp; |
79bd9814 TH |
5154 | |
5155 | /* | |
5156 | * Unregister events and notify userspace. | |
5157 | * Notify userspace about cgroup removing only after rmdir of cgroup | |
5158 | * directory to avoid race between userspace and kernelspace. | |
5159 | */ | |
fba94807 TH |
5160 | spin_lock(&memcg->event_list_lock); |
5161 | list_for_each_entry_safe(event, tmp, &memcg->event_list, list) { | |
79bd9814 TH |
5162 | list_del_init(&event->list); |
5163 | schedule_work(&event->remove); | |
5164 | } | |
fba94807 | 5165 | spin_unlock(&memcg->event_list_lock); |
ec64f515 | 5166 | |
776ed0f0 | 5167 | memcg_unregister_all_caches(memcg); |
33cb876e | 5168 | vmpressure_cleanup(&memcg->vmpressure); |
df878fb0 KH |
5169 | } |
5170 | ||
eb95419b | 5171 | static void mem_cgroup_css_free(struct cgroup_subsys_state *css) |
8cdea7c0 | 5172 | { |
eb95419b | 5173 | struct mem_cgroup *memcg = mem_cgroup_from_css(css); |
c268e994 | 5174 | |
10d5ebf4 | 5175 | memcg_destroy_kmem(memcg); |
465939a1 | 5176 | __mem_cgroup_free(memcg); |
8cdea7c0 BS |
5177 | } |
5178 | ||
1ced953b TH |
5179 | /** |
5180 | * mem_cgroup_css_reset - reset the states of a mem_cgroup | |
5181 | * @css: the target css | |
5182 | * | |
5183 | * Reset the states of the mem_cgroup associated with @css. This is | |
5184 | * invoked when the userland requests disabling on the default hierarchy | |
5185 | * but the memcg is pinned through dependency. The memcg should stop | |
5186 | * applying policies and should revert to the vanilla state as it may be | |
5187 | * made visible again. | |
5188 | * | |
5189 | * The current implementation only resets the essential configurations. | |
5190 | * This needs to be expanded to cover all the visible parts. | |
5191 | */ | |
5192 | static void mem_cgroup_css_reset(struct cgroup_subsys_state *css) | |
5193 | { | |
5194 | struct mem_cgroup *memcg = mem_cgroup_from_css(css); | |
5195 | ||
3e32cb2e JW |
5196 | mem_cgroup_resize_limit(memcg, PAGE_COUNTER_MAX); |
5197 | mem_cgroup_resize_memsw_limit(memcg, PAGE_COUNTER_MAX); | |
5198 | memcg_update_kmem_limit(memcg, PAGE_COUNTER_MAX); | |
5199 | memcg->soft_limit = 0; | |
1ced953b TH |
5200 | } |
5201 | ||
02491447 | 5202 | #ifdef CONFIG_MMU |
7dc74be0 | 5203 | /* Handlers for move charge at task migration. */ |
854ffa8d | 5204 | static int mem_cgroup_do_precharge(unsigned long count) |
7dc74be0 | 5205 | { |
05b84301 | 5206 | int ret; |
9476db97 JW |
5207 | |
5208 | /* Try a single bulk charge without reclaim first */ | |
00501b53 | 5209 | ret = try_charge(mc.to, GFP_KERNEL & ~__GFP_WAIT, count); |
9476db97 | 5210 | if (!ret) { |
854ffa8d | 5211 | mc.precharge += count; |
854ffa8d DN |
5212 | return ret; |
5213 | } | |
692e7c45 | 5214 | if (ret == -EINTR) { |
00501b53 | 5215 | cancel_charge(root_mem_cgroup, count); |
692e7c45 JW |
5216 | return ret; |
5217 | } | |
9476db97 JW |
5218 | |
5219 | /* Try charges one by one with reclaim */ | |
854ffa8d | 5220 | while (count--) { |
00501b53 | 5221 | ret = try_charge(mc.to, GFP_KERNEL & ~__GFP_NORETRY, 1); |
9476db97 JW |
5222 | /* |
5223 | * In case of failure, any residual charges against | |
5224 | * mc.to will be dropped by mem_cgroup_clear_mc() | |
692e7c45 JW |
5225 | * later on. However, cancel any charges that are |
5226 | * bypassed to root right away or they'll be lost. | |
9476db97 | 5227 | */ |
692e7c45 | 5228 | if (ret == -EINTR) |
00501b53 | 5229 | cancel_charge(root_mem_cgroup, 1); |
38c5d72f | 5230 | if (ret) |
38c5d72f | 5231 | return ret; |
854ffa8d | 5232 | mc.precharge++; |
9476db97 | 5233 | cond_resched(); |
854ffa8d | 5234 | } |
9476db97 | 5235 | return 0; |
4ffef5fe DN |
5236 | } |
5237 | ||
5238 | /** | |
8d32ff84 | 5239 | * get_mctgt_type - get target type of moving charge |
4ffef5fe DN |
5240 | * @vma: the vma the pte to be checked belongs |
5241 | * @addr: the address corresponding to the pte to be checked | |
5242 | * @ptent: the pte to be checked | |
02491447 | 5243 | * @target: the pointer the target page or swap ent will be stored(can be NULL) |
4ffef5fe DN |
5244 | * |
5245 | * Returns | |
5246 | * 0(MC_TARGET_NONE): if the pte is not a target for move charge. | |
5247 | * 1(MC_TARGET_PAGE): if the page corresponding to this pte is a target for | |
5248 | * move charge. if @target is not NULL, the page is stored in target->page | |
5249 | * with extra refcnt got(Callers should handle it). | |
02491447 DN |
5250 | * 2(MC_TARGET_SWAP): if the swap entry corresponding to this pte is a |
5251 | * target for charge migration. if @target is not NULL, the entry is stored | |
5252 | * in target->ent. | |
4ffef5fe DN |
5253 | * |
5254 | * Called with pte lock held. | |
5255 | */ | |
4ffef5fe DN |
5256 | union mc_target { |
5257 | struct page *page; | |
02491447 | 5258 | swp_entry_t ent; |
4ffef5fe DN |
5259 | }; |
5260 | ||
4ffef5fe | 5261 | enum mc_target_type { |
8d32ff84 | 5262 | MC_TARGET_NONE = 0, |
4ffef5fe | 5263 | MC_TARGET_PAGE, |
02491447 | 5264 | MC_TARGET_SWAP, |
4ffef5fe DN |
5265 | }; |
5266 | ||
90254a65 DN |
5267 | static struct page *mc_handle_present_pte(struct vm_area_struct *vma, |
5268 | unsigned long addr, pte_t ptent) | |
4ffef5fe | 5269 | { |
90254a65 | 5270 | struct page *page = vm_normal_page(vma, addr, ptent); |
4ffef5fe | 5271 | |
90254a65 DN |
5272 | if (!page || !page_mapped(page)) |
5273 | return NULL; | |
5274 | if (PageAnon(page)) { | |
5275 | /* we don't move shared anon */ | |
4b91355e | 5276 | if (!move_anon()) |
90254a65 | 5277 | return NULL; |
87946a72 DN |
5278 | } else if (!move_file()) |
5279 | /* we ignore mapcount for file pages */ | |
90254a65 DN |
5280 | return NULL; |
5281 | if (!get_page_unless_zero(page)) | |
5282 | return NULL; | |
5283 | ||
5284 | return page; | |
5285 | } | |
5286 | ||
4b91355e | 5287 | #ifdef CONFIG_SWAP |
90254a65 DN |
5288 | static struct page *mc_handle_swap_pte(struct vm_area_struct *vma, |
5289 | unsigned long addr, pte_t ptent, swp_entry_t *entry) | |
5290 | { | |
90254a65 DN |
5291 | struct page *page = NULL; |
5292 | swp_entry_t ent = pte_to_swp_entry(ptent); | |
5293 | ||
5294 | if (!move_anon() || non_swap_entry(ent)) | |
5295 | return NULL; | |
4b91355e KH |
5296 | /* |
5297 | * Because lookup_swap_cache() updates some statistics counter, | |
5298 | * we call find_get_page() with swapper_space directly. | |
5299 | */ | |
33806f06 | 5300 | page = find_get_page(swap_address_space(ent), ent.val); |
90254a65 DN |
5301 | if (do_swap_account) |
5302 | entry->val = ent.val; | |
5303 | ||
5304 | return page; | |
5305 | } | |
4b91355e KH |
5306 | #else |
5307 | static struct page *mc_handle_swap_pte(struct vm_area_struct *vma, | |
5308 | unsigned long addr, pte_t ptent, swp_entry_t *entry) | |
5309 | { | |
5310 | return NULL; | |
5311 | } | |
5312 | #endif | |
90254a65 | 5313 | |
87946a72 DN |
5314 | static struct page *mc_handle_file_pte(struct vm_area_struct *vma, |
5315 | unsigned long addr, pte_t ptent, swp_entry_t *entry) | |
5316 | { | |
5317 | struct page *page = NULL; | |
87946a72 DN |
5318 | struct address_space *mapping; |
5319 | pgoff_t pgoff; | |
5320 | ||
5321 | if (!vma->vm_file) /* anonymous vma */ | |
5322 | return NULL; | |
5323 | if (!move_file()) | |
5324 | return NULL; | |
5325 | ||
87946a72 DN |
5326 | mapping = vma->vm_file->f_mapping; |
5327 | if (pte_none(ptent)) | |
5328 | pgoff = linear_page_index(vma, addr); | |
5329 | else /* pte_file(ptent) is true */ | |
5330 | pgoff = pte_to_pgoff(ptent); | |
5331 | ||
5332 | /* page is moved even if it's not RSS of this task(page-faulted). */ | |
aa3b1895 HD |
5333 | #ifdef CONFIG_SWAP |
5334 | /* shmem/tmpfs may report page out on swap: account for that too. */ | |
139b6a6f JW |
5335 | if (shmem_mapping(mapping)) { |
5336 | page = find_get_entry(mapping, pgoff); | |
5337 | if (radix_tree_exceptional_entry(page)) { | |
5338 | swp_entry_t swp = radix_to_swp_entry(page); | |
5339 | if (do_swap_account) | |
5340 | *entry = swp; | |
5341 | page = find_get_page(swap_address_space(swp), swp.val); | |
5342 | } | |
5343 | } else | |
5344 | page = find_get_page(mapping, pgoff); | |
5345 | #else | |
5346 | page = find_get_page(mapping, pgoff); | |
aa3b1895 | 5347 | #endif |
87946a72 DN |
5348 | return page; |
5349 | } | |
5350 | ||
8d32ff84 | 5351 | static enum mc_target_type get_mctgt_type(struct vm_area_struct *vma, |
90254a65 DN |
5352 | unsigned long addr, pte_t ptent, union mc_target *target) |
5353 | { | |
5354 | struct page *page = NULL; | |
5355 | struct page_cgroup *pc; | |
8d32ff84 | 5356 | enum mc_target_type ret = MC_TARGET_NONE; |
90254a65 DN |
5357 | swp_entry_t ent = { .val = 0 }; |
5358 | ||
5359 | if (pte_present(ptent)) | |
5360 | page = mc_handle_present_pte(vma, addr, ptent); | |
5361 | else if (is_swap_pte(ptent)) | |
5362 | page = mc_handle_swap_pte(vma, addr, ptent, &ent); | |
87946a72 DN |
5363 | else if (pte_none(ptent) || pte_file(ptent)) |
5364 | page = mc_handle_file_pte(vma, addr, ptent, &ent); | |
90254a65 DN |
5365 | |
5366 | if (!page && !ent.val) | |
8d32ff84 | 5367 | return ret; |
02491447 DN |
5368 | if (page) { |
5369 | pc = lookup_page_cgroup(page); | |
5370 | /* | |
0a31bc97 JW |
5371 | * Do only loose check w/o serialization. |
5372 | * mem_cgroup_move_account() checks the pc is valid or | |
5373 | * not under LRU exclusion. | |
02491447 DN |
5374 | */ |
5375 | if (PageCgroupUsed(pc) && pc->mem_cgroup == mc.from) { | |
5376 | ret = MC_TARGET_PAGE; | |
5377 | if (target) | |
5378 | target->page = page; | |
5379 | } | |
5380 | if (!ret || !target) | |
5381 | put_page(page); | |
5382 | } | |
90254a65 DN |
5383 | /* There is a swap entry and a page doesn't exist or isn't charged */ |
5384 | if (ent.val && !ret && | |
34c00c31 | 5385 | mem_cgroup_id(mc.from) == lookup_swap_cgroup_id(ent)) { |
7f0f1546 KH |
5386 | ret = MC_TARGET_SWAP; |
5387 | if (target) | |
5388 | target->ent = ent; | |
4ffef5fe | 5389 | } |
4ffef5fe DN |
5390 | return ret; |
5391 | } | |
5392 | ||
12724850 NH |
5393 | #ifdef CONFIG_TRANSPARENT_HUGEPAGE |
5394 | /* | |
5395 | * We don't consider swapping or file mapped pages because THP does not | |
5396 | * support them for now. | |
5397 | * Caller should make sure that pmd_trans_huge(pmd) is true. | |
5398 | */ | |
5399 | static enum mc_target_type get_mctgt_type_thp(struct vm_area_struct *vma, | |
5400 | unsigned long addr, pmd_t pmd, union mc_target *target) | |
5401 | { | |
5402 | struct page *page = NULL; | |
5403 | struct page_cgroup *pc; | |
5404 | enum mc_target_type ret = MC_TARGET_NONE; | |
5405 | ||
5406 | page = pmd_page(pmd); | |
309381fe | 5407 | VM_BUG_ON_PAGE(!page || !PageHead(page), page); |
12724850 NH |
5408 | if (!move_anon()) |
5409 | return ret; | |
5410 | pc = lookup_page_cgroup(page); | |
5411 | if (PageCgroupUsed(pc) && pc->mem_cgroup == mc.from) { | |
5412 | ret = MC_TARGET_PAGE; | |
5413 | if (target) { | |
5414 | get_page(page); | |
5415 | target->page = page; | |
5416 | } | |
5417 | } | |
5418 | return ret; | |
5419 | } | |
5420 | #else | |
5421 | static inline enum mc_target_type get_mctgt_type_thp(struct vm_area_struct *vma, | |
5422 | unsigned long addr, pmd_t pmd, union mc_target *target) | |
5423 | { | |
5424 | return MC_TARGET_NONE; | |
5425 | } | |
5426 | #endif | |
5427 | ||
4ffef5fe DN |
5428 | static int mem_cgroup_count_precharge_pte_range(pmd_t *pmd, |
5429 | unsigned long addr, unsigned long end, | |
5430 | struct mm_walk *walk) | |
5431 | { | |
5432 | struct vm_area_struct *vma = walk->private; | |
5433 | pte_t *pte; | |
5434 | spinlock_t *ptl; | |
5435 | ||
bf929152 | 5436 | if (pmd_trans_huge_lock(pmd, vma, &ptl) == 1) { |
12724850 NH |
5437 | if (get_mctgt_type_thp(vma, addr, *pmd, NULL) == MC_TARGET_PAGE) |
5438 | mc.precharge += HPAGE_PMD_NR; | |
bf929152 | 5439 | spin_unlock(ptl); |
1a5a9906 | 5440 | return 0; |
12724850 | 5441 | } |
03319327 | 5442 | |
45f83cef AA |
5443 | if (pmd_trans_unstable(pmd)) |
5444 | return 0; | |
4ffef5fe DN |
5445 | pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl); |
5446 | for (; addr != end; pte++, addr += PAGE_SIZE) | |
8d32ff84 | 5447 | if (get_mctgt_type(vma, addr, *pte, NULL)) |
4ffef5fe DN |
5448 | mc.precharge++; /* increment precharge temporarily */ |
5449 | pte_unmap_unlock(pte - 1, ptl); | |
5450 | cond_resched(); | |
5451 | ||
7dc74be0 DN |
5452 | return 0; |
5453 | } | |
5454 | ||
4ffef5fe DN |
5455 | static unsigned long mem_cgroup_count_precharge(struct mm_struct *mm) |
5456 | { | |
5457 | unsigned long precharge; | |
5458 | struct vm_area_struct *vma; | |
5459 | ||
dfe076b0 | 5460 | down_read(&mm->mmap_sem); |
4ffef5fe DN |
5461 | for (vma = mm->mmap; vma; vma = vma->vm_next) { |
5462 | struct mm_walk mem_cgroup_count_precharge_walk = { | |
5463 | .pmd_entry = mem_cgroup_count_precharge_pte_range, | |
5464 | .mm = mm, | |
5465 | .private = vma, | |
5466 | }; | |
5467 | if (is_vm_hugetlb_page(vma)) | |
5468 | continue; | |
4ffef5fe DN |
5469 | walk_page_range(vma->vm_start, vma->vm_end, |
5470 | &mem_cgroup_count_precharge_walk); | |
5471 | } | |
dfe076b0 | 5472 | up_read(&mm->mmap_sem); |
4ffef5fe DN |
5473 | |
5474 | precharge = mc.precharge; | |
5475 | mc.precharge = 0; | |
5476 | ||
5477 | return precharge; | |
5478 | } | |
5479 | ||
4ffef5fe DN |
5480 | static int mem_cgroup_precharge_mc(struct mm_struct *mm) |
5481 | { | |
dfe076b0 DN |
5482 | unsigned long precharge = mem_cgroup_count_precharge(mm); |
5483 | ||
5484 | VM_BUG_ON(mc.moving_task); | |
5485 | mc.moving_task = current; | |
5486 | return mem_cgroup_do_precharge(precharge); | |
4ffef5fe DN |
5487 | } |
5488 | ||
dfe076b0 DN |
5489 | /* cancels all extra charges on mc.from and mc.to, and wakes up all waiters. */ |
5490 | static void __mem_cgroup_clear_mc(void) | |
4ffef5fe | 5491 | { |
2bd9bb20 KH |
5492 | struct mem_cgroup *from = mc.from; |
5493 | struct mem_cgroup *to = mc.to; | |
5494 | ||
4ffef5fe | 5495 | /* we must uncharge all the leftover precharges from mc.to */ |
854ffa8d | 5496 | if (mc.precharge) { |
00501b53 | 5497 | cancel_charge(mc.to, mc.precharge); |
854ffa8d DN |
5498 | mc.precharge = 0; |
5499 | } | |
5500 | /* | |
5501 | * we didn't uncharge from mc.from at mem_cgroup_move_account(), so | |
5502 | * we must uncharge here. | |
5503 | */ | |
5504 | if (mc.moved_charge) { | |
00501b53 | 5505 | cancel_charge(mc.from, mc.moved_charge); |
854ffa8d | 5506 | mc.moved_charge = 0; |
4ffef5fe | 5507 | } |
483c30b5 DN |
5508 | /* we must fixup refcnts and charges */ |
5509 | if (mc.moved_swap) { | |
483c30b5 | 5510 | /* uncharge swap account from the old cgroup */ |
ce00a967 | 5511 | if (!mem_cgroup_is_root(mc.from)) |
3e32cb2e | 5512 | page_counter_uncharge(&mc.from->memsw, mc.moved_swap); |
483c30b5 | 5513 | |
05b84301 | 5514 | /* |
3e32cb2e JW |
5515 | * we charged both to->memory and to->memsw, so we |
5516 | * should uncharge to->memory. | |
05b84301 | 5517 | */ |
ce00a967 | 5518 | if (!mem_cgroup_is_root(mc.to)) |
3e32cb2e JW |
5519 | page_counter_uncharge(&mc.to->memory, mc.moved_swap); |
5520 | ||
e8ea14cc | 5521 | css_put_many(&mc.from->css, mc.moved_swap); |
3e32cb2e | 5522 | |
4050377b | 5523 | /* we've already done css_get(mc.to) */ |
483c30b5 DN |
5524 | mc.moved_swap = 0; |
5525 | } | |
dfe076b0 DN |
5526 | memcg_oom_recover(from); |
5527 | memcg_oom_recover(to); | |
5528 | wake_up_all(&mc.waitq); | |
5529 | } | |
5530 | ||
5531 | static void mem_cgroup_clear_mc(void) | |
5532 | { | |
5533 | struct mem_cgroup *from = mc.from; | |
5534 | ||
5535 | /* | |
5536 | * we must clear moving_task before waking up waiters at the end of | |
5537 | * task migration. | |
5538 | */ | |
5539 | mc.moving_task = NULL; | |
5540 | __mem_cgroup_clear_mc(); | |
2bd9bb20 | 5541 | spin_lock(&mc.lock); |
4ffef5fe DN |
5542 | mc.from = NULL; |
5543 | mc.to = NULL; | |
2bd9bb20 | 5544 | spin_unlock(&mc.lock); |
32047e2a | 5545 | mem_cgroup_end_move(from); |
4ffef5fe DN |
5546 | } |
5547 | ||
eb95419b | 5548 | static int mem_cgroup_can_attach(struct cgroup_subsys_state *css, |
761b3ef5 | 5549 | struct cgroup_taskset *tset) |
7dc74be0 | 5550 | { |
2f7ee569 | 5551 | struct task_struct *p = cgroup_taskset_first(tset); |
7dc74be0 | 5552 | int ret = 0; |
eb95419b | 5553 | struct mem_cgroup *memcg = mem_cgroup_from_css(css); |
ee5e8472 | 5554 | unsigned long move_charge_at_immigrate; |
7dc74be0 | 5555 | |
ee5e8472 GC |
5556 | /* |
5557 | * We are now commited to this value whatever it is. Changes in this | |
5558 | * tunable will only affect upcoming migrations, not the current one. | |
5559 | * So we need to save it, and keep it going. | |
5560 | */ | |
5561 | move_charge_at_immigrate = memcg->move_charge_at_immigrate; | |
5562 | if (move_charge_at_immigrate) { | |
7dc74be0 DN |
5563 | struct mm_struct *mm; |
5564 | struct mem_cgroup *from = mem_cgroup_from_task(p); | |
5565 | ||
c0ff4b85 | 5566 | VM_BUG_ON(from == memcg); |
7dc74be0 DN |
5567 | |
5568 | mm = get_task_mm(p); | |
5569 | if (!mm) | |
5570 | return 0; | |
7dc74be0 | 5571 | /* We move charges only when we move a owner of the mm */ |
4ffef5fe DN |
5572 | if (mm->owner == p) { |
5573 | VM_BUG_ON(mc.from); | |
5574 | VM_BUG_ON(mc.to); | |
5575 | VM_BUG_ON(mc.precharge); | |
854ffa8d | 5576 | VM_BUG_ON(mc.moved_charge); |
483c30b5 | 5577 | VM_BUG_ON(mc.moved_swap); |
32047e2a | 5578 | mem_cgroup_start_move(from); |
2bd9bb20 | 5579 | spin_lock(&mc.lock); |
4ffef5fe | 5580 | mc.from = from; |
c0ff4b85 | 5581 | mc.to = memcg; |
ee5e8472 | 5582 | mc.immigrate_flags = move_charge_at_immigrate; |
2bd9bb20 | 5583 | spin_unlock(&mc.lock); |
dfe076b0 | 5584 | /* We set mc.moving_task later */ |
4ffef5fe DN |
5585 | |
5586 | ret = mem_cgroup_precharge_mc(mm); | |
5587 | if (ret) | |
5588 | mem_cgroup_clear_mc(); | |
dfe076b0 DN |
5589 | } |
5590 | mmput(mm); | |
7dc74be0 DN |
5591 | } |
5592 | return ret; | |
5593 | } | |
5594 | ||
eb95419b | 5595 | static void mem_cgroup_cancel_attach(struct cgroup_subsys_state *css, |
761b3ef5 | 5596 | struct cgroup_taskset *tset) |
7dc74be0 | 5597 | { |
4ffef5fe | 5598 | mem_cgroup_clear_mc(); |
7dc74be0 DN |
5599 | } |
5600 | ||
4ffef5fe DN |
5601 | static int mem_cgroup_move_charge_pte_range(pmd_t *pmd, |
5602 | unsigned long addr, unsigned long end, | |
5603 | struct mm_walk *walk) | |
7dc74be0 | 5604 | { |
4ffef5fe DN |
5605 | int ret = 0; |
5606 | struct vm_area_struct *vma = walk->private; | |
5607 | pte_t *pte; | |
5608 | spinlock_t *ptl; | |
12724850 NH |
5609 | enum mc_target_type target_type; |
5610 | union mc_target target; | |
5611 | struct page *page; | |
5612 | struct page_cgroup *pc; | |
4ffef5fe | 5613 | |
12724850 NH |
5614 | /* |
5615 | * We don't take compound_lock() here but no race with splitting thp | |
5616 | * happens because: | |
5617 | * - if pmd_trans_huge_lock() returns 1, the relevant thp is not | |
5618 | * under splitting, which means there's no concurrent thp split, | |
5619 | * - if another thread runs into split_huge_page() just after we | |
5620 | * entered this if-block, the thread must wait for page table lock | |
5621 | * to be unlocked in __split_huge_page_splitting(), where the main | |
5622 | * part of thp split is not executed yet. | |
5623 | */ | |
bf929152 | 5624 | if (pmd_trans_huge_lock(pmd, vma, &ptl) == 1) { |
62ade86a | 5625 | if (mc.precharge < HPAGE_PMD_NR) { |
bf929152 | 5626 | spin_unlock(ptl); |
12724850 NH |
5627 | return 0; |
5628 | } | |
5629 | target_type = get_mctgt_type_thp(vma, addr, *pmd, &target); | |
5630 | if (target_type == MC_TARGET_PAGE) { | |
5631 | page = target.page; | |
5632 | if (!isolate_lru_page(page)) { | |
5633 | pc = lookup_page_cgroup(page); | |
5634 | if (!mem_cgroup_move_account(page, HPAGE_PMD_NR, | |
2f3479b1 | 5635 | pc, mc.from, mc.to)) { |
12724850 NH |
5636 | mc.precharge -= HPAGE_PMD_NR; |
5637 | mc.moved_charge += HPAGE_PMD_NR; | |
5638 | } | |
5639 | putback_lru_page(page); | |
5640 | } | |
5641 | put_page(page); | |
5642 | } | |
bf929152 | 5643 | spin_unlock(ptl); |
1a5a9906 | 5644 | return 0; |
12724850 NH |
5645 | } |
5646 | ||
45f83cef AA |
5647 | if (pmd_trans_unstable(pmd)) |
5648 | return 0; | |
4ffef5fe DN |
5649 | retry: |
5650 | pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl); | |
5651 | for (; addr != end; addr += PAGE_SIZE) { | |
5652 | pte_t ptent = *(pte++); | |
02491447 | 5653 | swp_entry_t ent; |
4ffef5fe DN |
5654 | |
5655 | if (!mc.precharge) | |
5656 | break; | |
5657 | ||
8d32ff84 | 5658 | switch (get_mctgt_type(vma, addr, ptent, &target)) { |
4ffef5fe DN |
5659 | case MC_TARGET_PAGE: |
5660 | page = target.page; | |
5661 | if (isolate_lru_page(page)) | |
5662 | goto put; | |
5663 | pc = lookup_page_cgroup(page); | |
7ec99d62 | 5664 | if (!mem_cgroup_move_account(page, 1, pc, |
2f3479b1 | 5665 | mc.from, mc.to)) { |
4ffef5fe | 5666 | mc.precharge--; |
854ffa8d DN |
5667 | /* we uncharge from mc.from later. */ |
5668 | mc.moved_charge++; | |
4ffef5fe DN |
5669 | } |
5670 | putback_lru_page(page); | |
8d32ff84 | 5671 | put: /* get_mctgt_type() gets the page */ |
4ffef5fe DN |
5672 | put_page(page); |
5673 | break; | |
02491447 DN |
5674 | case MC_TARGET_SWAP: |
5675 | ent = target.ent; | |
e91cbb42 | 5676 | if (!mem_cgroup_move_swap_account(ent, mc.from, mc.to)) { |
02491447 | 5677 | mc.precharge--; |
483c30b5 DN |
5678 | /* we fixup refcnts and charges later. */ |
5679 | mc.moved_swap++; | |
5680 | } | |
02491447 | 5681 | break; |
4ffef5fe DN |
5682 | default: |
5683 | break; | |
5684 | } | |
5685 | } | |
5686 | pte_unmap_unlock(pte - 1, ptl); | |
5687 | cond_resched(); | |
5688 | ||
5689 | if (addr != end) { | |
5690 | /* | |
5691 | * We have consumed all precharges we got in can_attach(). | |
5692 | * We try charge one by one, but don't do any additional | |
5693 | * charges to mc.to if we have failed in charge once in attach() | |
5694 | * phase. | |
5695 | */ | |
854ffa8d | 5696 | ret = mem_cgroup_do_precharge(1); |
4ffef5fe DN |
5697 | if (!ret) |
5698 | goto retry; | |
5699 | } | |
5700 | ||
5701 | return ret; | |
5702 | } | |
5703 | ||
5704 | static void mem_cgroup_move_charge(struct mm_struct *mm) | |
5705 | { | |
5706 | struct vm_area_struct *vma; | |
5707 | ||
5708 | lru_add_drain_all(); | |
dfe076b0 DN |
5709 | retry: |
5710 | if (unlikely(!down_read_trylock(&mm->mmap_sem))) { | |
5711 | /* | |
5712 | * Someone who are holding the mmap_sem might be waiting in | |
5713 | * waitq. So we cancel all extra charges, wake up all waiters, | |
5714 | * and retry. Because we cancel precharges, we might not be able | |
5715 | * to move enough charges, but moving charge is a best-effort | |
5716 | * feature anyway, so it wouldn't be a big problem. | |
5717 | */ | |
5718 | __mem_cgroup_clear_mc(); | |
5719 | cond_resched(); | |
5720 | goto retry; | |
5721 | } | |
4ffef5fe DN |
5722 | for (vma = mm->mmap; vma; vma = vma->vm_next) { |
5723 | int ret; | |
5724 | struct mm_walk mem_cgroup_move_charge_walk = { | |
5725 | .pmd_entry = mem_cgroup_move_charge_pte_range, | |
5726 | .mm = mm, | |
5727 | .private = vma, | |
5728 | }; | |
5729 | if (is_vm_hugetlb_page(vma)) | |
5730 | continue; | |
4ffef5fe DN |
5731 | ret = walk_page_range(vma->vm_start, vma->vm_end, |
5732 | &mem_cgroup_move_charge_walk); | |
5733 | if (ret) | |
5734 | /* | |
5735 | * means we have consumed all precharges and failed in | |
5736 | * doing additional charge. Just abandon here. | |
5737 | */ | |
5738 | break; | |
5739 | } | |
dfe076b0 | 5740 | up_read(&mm->mmap_sem); |
7dc74be0 DN |
5741 | } |
5742 | ||
eb95419b | 5743 | static void mem_cgroup_move_task(struct cgroup_subsys_state *css, |
761b3ef5 | 5744 | struct cgroup_taskset *tset) |
67e465a7 | 5745 | { |
2f7ee569 | 5746 | struct task_struct *p = cgroup_taskset_first(tset); |
a433658c | 5747 | struct mm_struct *mm = get_task_mm(p); |
dfe076b0 | 5748 | |
dfe076b0 | 5749 | if (mm) { |
a433658c KM |
5750 | if (mc.to) |
5751 | mem_cgroup_move_charge(mm); | |
dfe076b0 DN |
5752 | mmput(mm); |
5753 | } | |
a433658c KM |
5754 | if (mc.to) |
5755 | mem_cgroup_clear_mc(); | |
67e465a7 | 5756 | } |
5cfb80a7 | 5757 | #else /* !CONFIG_MMU */ |
eb95419b | 5758 | static int mem_cgroup_can_attach(struct cgroup_subsys_state *css, |
761b3ef5 | 5759 | struct cgroup_taskset *tset) |
5cfb80a7 DN |
5760 | { |
5761 | return 0; | |
5762 | } | |
eb95419b | 5763 | static void mem_cgroup_cancel_attach(struct cgroup_subsys_state *css, |
761b3ef5 | 5764 | struct cgroup_taskset *tset) |
5cfb80a7 DN |
5765 | { |
5766 | } | |
eb95419b | 5767 | static void mem_cgroup_move_task(struct cgroup_subsys_state *css, |
761b3ef5 | 5768 | struct cgroup_taskset *tset) |
5cfb80a7 DN |
5769 | { |
5770 | } | |
5771 | #endif | |
67e465a7 | 5772 | |
f00baae7 TH |
5773 | /* |
5774 | * Cgroup retains root cgroups across [un]mount cycles making it necessary | |
aa6ec29b TH |
5775 | * to verify whether we're attached to the default hierarchy on each mount |
5776 | * attempt. | |
f00baae7 | 5777 | */ |
eb95419b | 5778 | static void mem_cgroup_bind(struct cgroup_subsys_state *root_css) |
f00baae7 TH |
5779 | { |
5780 | /* | |
aa6ec29b | 5781 | * use_hierarchy is forced on the default hierarchy. cgroup core |
f00baae7 TH |
5782 | * guarantees that @root doesn't have any children, so turning it |
5783 | * on for the root memcg is enough. | |
5784 | */ | |
aa6ec29b | 5785 | if (cgroup_on_dfl(root_css->cgroup)) |
eb95419b | 5786 | mem_cgroup_from_css(root_css)->use_hierarchy = true; |
f00baae7 TH |
5787 | } |
5788 | ||
073219e9 | 5789 | struct cgroup_subsys memory_cgrp_subsys = { |
92fb9748 | 5790 | .css_alloc = mem_cgroup_css_alloc, |
d142e3e6 | 5791 | .css_online = mem_cgroup_css_online, |
92fb9748 TH |
5792 | .css_offline = mem_cgroup_css_offline, |
5793 | .css_free = mem_cgroup_css_free, | |
1ced953b | 5794 | .css_reset = mem_cgroup_css_reset, |
7dc74be0 DN |
5795 | .can_attach = mem_cgroup_can_attach, |
5796 | .cancel_attach = mem_cgroup_cancel_attach, | |
67e465a7 | 5797 | .attach = mem_cgroup_move_task, |
f00baae7 | 5798 | .bind = mem_cgroup_bind, |
5577964e | 5799 | .legacy_cftypes = mem_cgroup_files, |
6d12e2d8 | 5800 | .early_init = 0, |
8cdea7c0 | 5801 | }; |
c077719b | 5802 | |
c255a458 | 5803 | #ifdef CONFIG_MEMCG_SWAP |
a42c390c MH |
5804 | static int __init enable_swap_account(char *s) |
5805 | { | |
a2c8990a | 5806 | if (!strcmp(s, "1")) |
a42c390c | 5807 | really_do_swap_account = 1; |
a2c8990a | 5808 | else if (!strcmp(s, "0")) |
a42c390c MH |
5809 | really_do_swap_account = 0; |
5810 | return 1; | |
5811 | } | |
a2c8990a | 5812 | __setup("swapaccount=", enable_swap_account); |
c077719b | 5813 | |
2d11085e MH |
5814 | static void __init memsw_file_init(void) |
5815 | { | |
2cf669a5 TH |
5816 | WARN_ON(cgroup_add_legacy_cftypes(&memory_cgrp_subsys, |
5817 | memsw_cgroup_files)); | |
6acc8b02 MH |
5818 | } |
5819 | ||
5820 | static void __init enable_swap_cgroup(void) | |
5821 | { | |
5822 | if (!mem_cgroup_disabled() && really_do_swap_account) { | |
5823 | do_swap_account = 1; | |
5824 | memsw_file_init(); | |
5825 | } | |
2d11085e | 5826 | } |
6acc8b02 | 5827 | |
2d11085e | 5828 | #else |
6acc8b02 | 5829 | static void __init enable_swap_cgroup(void) |
2d11085e MH |
5830 | { |
5831 | } | |
c077719b | 5832 | #endif |
2d11085e | 5833 | |
0a31bc97 JW |
5834 | #ifdef CONFIG_MEMCG_SWAP |
5835 | /** | |
5836 | * mem_cgroup_swapout - transfer a memsw charge to swap | |
5837 | * @page: page whose memsw charge to transfer | |
5838 | * @entry: swap entry to move the charge to | |
5839 | * | |
5840 | * Transfer the memsw charge of @page to @entry. | |
5841 | */ | |
5842 | void mem_cgroup_swapout(struct page *page, swp_entry_t entry) | |
5843 | { | |
5844 | struct page_cgroup *pc; | |
5845 | unsigned short oldid; | |
5846 | ||
5847 | VM_BUG_ON_PAGE(PageLRU(page), page); | |
5848 | VM_BUG_ON_PAGE(page_count(page), page); | |
5849 | ||
5850 | if (!do_swap_account) | |
5851 | return; | |
5852 | ||
5853 | pc = lookup_page_cgroup(page); | |
5854 | ||
5855 | /* Readahead page, never charged */ | |
5856 | if (!PageCgroupUsed(pc)) | |
5857 | return; | |
5858 | ||
5859 | VM_BUG_ON_PAGE(!(pc->flags & PCG_MEMSW), page); | |
5860 | ||
5861 | oldid = swap_cgroup_record(entry, mem_cgroup_id(pc->mem_cgroup)); | |
5862 | VM_BUG_ON_PAGE(oldid, page); | |
5863 | ||
5864 | pc->flags &= ~PCG_MEMSW; | |
5865 | css_get(&pc->mem_cgroup->css); | |
5866 | mem_cgroup_swap_statistics(pc->mem_cgroup, true); | |
5867 | } | |
5868 | ||
5869 | /** | |
5870 | * mem_cgroup_uncharge_swap - uncharge a swap entry | |
5871 | * @entry: swap entry to uncharge | |
5872 | * | |
5873 | * Drop the memsw charge associated with @entry. | |
5874 | */ | |
5875 | void mem_cgroup_uncharge_swap(swp_entry_t entry) | |
5876 | { | |
5877 | struct mem_cgroup *memcg; | |
5878 | unsigned short id; | |
5879 | ||
5880 | if (!do_swap_account) | |
5881 | return; | |
5882 | ||
5883 | id = swap_cgroup_record(entry, 0); | |
5884 | rcu_read_lock(); | |
5885 | memcg = mem_cgroup_lookup(id); | |
5886 | if (memcg) { | |
ce00a967 | 5887 | if (!mem_cgroup_is_root(memcg)) |
3e32cb2e | 5888 | page_counter_uncharge(&memcg->memsw, 1); |
0a31bc97 JW |
5889 | mem_cgroup_swap_statistics(memcg, false); |
5890 | css_put(&memcg->css); | |
5891 | } | |
5892 | rcu_read_unlock(); | |
5893 | } | |
5894 | #endif | |
5895 | ||
00501b53 JW |
5896 | /** |
5897 | * mem_cgroup_try_charge - try charging a page | |
5898 | * @page: page to charge | |
5899 | * @mm: mm context of the victim | |
5900 | * @gfp_mask: reclaim mode | |
5901 | * @memcgp: charged memcg return | |
5902 | * | |
5903 | * Try to charge @page to the memcg that @mm belongs to, reclaiming | |
5904 | * pages according to @gfp_mask if necessary. | |
5905 | * | |
5906 | * Returns 0 on success, with *@memcgp pointing to the charged memcg. | |
5907 | * Otherwise, an error code is returned. | |
5908 | * | |
5909 | * After page->mapping has been set up, the caller must finalize the | |
5910 | * charge with mem_cgroup_commit_charge(). Or abort the transaction | |
5911 | * with mem_cgroup_cancel_charge() in case page instantiation fails. | |
5912 | */ | |
5913 | int mem_cgroup_try_charge(struct page *page, struct mm_struct *mm, | |
5914 | gfp_t gfp_mask, struct mem_cgroup **memcgp) | |
5915 | { | |
5916 | struct mem_cgroup *memcg = NULL; | |
5917 | unsigned int nr_pages = 1; | |
5918 | int ret = 0; | |
5919 | ||
5920 | if (mem_cgroup_disabled()) | |
5921 | goto out; | |
5922 | ||
5923 | if (PageSwapCache(page)) { | |
5924 | struct page_cgroup *pc = lookup_page_cgroup(page); | |
5925 | /* | |
5926 | * Every swap fault against a single page tries to charge the | |
5927 | * page, bail as early as possible. shmem_unuse() encounters | |
5928 | * already charged pages, too. The USED bit is protected by | |
5929 | * the page lock, which serializes swap cache removal, which | |
5930 | * in turn serializes uncharging. | |
5931 | */ | |
5932 | if (PageCgroupUsed(pc)) | |
5933 | goto out; | |
5934 | } | |
5935 | ||
5936 | if (PageTransHuge(page)) { | |
5937 | nr_pages <<= compound_order(page); | |
5938 | VM_BUG_ON_PAGE(!PageTransHuge(page), page); | |
5939 | } | |
5940 | ||
5941 | if (do_swap_account && PageSwapCache(page)) | |
5942 | memcg = try_get_mem_cgroup_from_page(page); | |
5943 | if (!memcg) | |
5944 | memcg = get_mem_cgroup_from_mm(mm); | |
5945 | ||
5946 | ret = try_charge(memcg, gfp_mask, nr_pages); | |
5947 | ||
5948 | css_put(&memcg->css); | |
5949 | ||
5950 | if (ret == -EINTR) { | |
5951 | memcg = root_mem_cgroup; | |
5952 | ret = 0; | |
5953 | } | |
5954 | out: | |
5955 | *memcgp = memcg; | |
5956 | return ret; | |
5957 | } | |
5958 | ||
5959 | /** | |
5960 | * mem_cgroup_commit_charge - commit a page charge | |
5961 | * @page: page to charge | |
5962 | * @memcg: memcg to charge the page to | |
5963 | * @lrucare: page might be on LRU already | |
5964 | * | |
5965 | * Finalize a charge transaction started by mem_cgroup_try_charge(), | |
5966 | * after page->mapping has been set up. This must happen atomically | |
5967 | * as part of the page instantiation, i.e. under the page table lock | |
5968 | * for anonymous pages, under the page lock for page and swap cache. | |
5969 | * | |
5970 | * In addition, the page must not be on the LRU during the commit, to | |
5971 | * prevent racing with task migration. If it might be, use @lrucare. | |
5972 | * | |
5973 | * Use mem_cgroup_cancel_charge() to cancel the transaction instead. | |
5974 | */ | |
5975 | void mem_cgroup_commit_charge(struct page *page, struct mem_cgroup *memcg, | |
5976 | bool lrucare) | |
5977 | { | |
5978 | unsigned int nr_pages = 1; | |
5979 | ||
5980 | VM_BUG_ON_PAGE(!page->mapping, page); | |
5981 | VM_BUG_ON_PAGE(PageLRU(page) && !lrucare, page); | |
5982 | ||
5983 | if (mem_cgroup_disabled()) | |
5984 | return; | |
5985 | /* | |
5986 | * Swap faults will attempt to charge the same page multiple | |
5987 | * times. But reuse_swap_page() might have removed the page | |
5988 | * from swapcache already, so we can't check PageSwapCache(). | |
5989 | */ | |
5990 | if (!memcg) | |
5991 | return; | |
5992 | ||
6abb5a86 JW |
5993 | commit_charge(page, memcg, lrucare); |
5994 | ||
00501b53 JW |
5995 | if (PageTransHuge(page)) { |
5996 | nr_pages <<= compound_order(page); | |
5997 | VM_BUG_ON_PAGE(!PageTransHuge(page), page); | |
5998 | } | |
5999 | ||
6abb5a86 JW |
6000 | local_irq_disable(); |
6001 | mem_cgroup_charge_statistics(memcg, page, nr_pages); | |
6002 | memcg_check_events(memcg, page); | |
6003 | local_irq_enable(); | |
00501b53 JW |
6004 | |
6005 | if (do_swap_account && PageSwapCache(page)) { | |
6006 | swp_entry_t entry = { .val = page_private(page) }; | |
6007 | /* | |
6008 | * The swap entry might not get freed for a long time, | |
6009 | * let's not wait for it. The page already received a | |
6010 | * memory+swap charge, drop the swap entry duplicate. | |
6011 | */ | |
6012 | mem_cgroup_uncharge_swap(entry); | |
6013 | } | |
6014 | } | |
6015 | ||
6016 | /** | |
6017 | * mem_cgroup_cancel_charge - cancel a page charge | |
6018 | * @page: page to charge | |
6019 | * @memcg: memcg to charge the page to | |
6020 | * | |
6021 | * Cancel a charge transaction started by mem_cgroup_try_charge(). | |
6022 | */ | |
6023 | void mem_cgroup_cancel_charge(struct page *page, struct mem_cgroup *memcg) | |
6024 | { | |
6025 | unsigned int nr_pages = 1; | |
6026 | ||
6027 | if (mem_cgroup_disabled()) | |
6028 | return; | |
6029 | /* | |
6030 | * Swap faults will attempt to charge the same page multiple | |
6031 | * times. But reuse_swap_page() might have removed the page | |
6032 | * from swapcache already, so we can't check PageSwapCache(). | |
6033 | */ | |
6034 | if (!memcg) | |
6035 | return; | |
6036 | ||
6037 | if (PageTransHuge(page)) { | |
6038 | nr_pages <<= compound_order(page); | |
6039 | VM_BUG_ON_PAGE(!PageTransHuge(page), page); | |
6040 | } | |
6041 | ||
6042 | cancel_charge(memcg, nr_pages); | |
6043 | } | |
6044 | ||
747db954 JW |
6045 | static void uncharge_batch(struct mem_cgroup *memcg, unsigned long pgpgout, |
6046 | unsigned long nr_mem, unsigned long nr_memsw, | |
6047 | unsigned long nr_anon, unsigned long nr_file, | |
6048 | unsigned long nr_huge, struct page *dummy_page) | |
6049 | { | |
6050 | unsigned long flags; | |
6051 | ||
ce00a967 JW |
6052 | if (!mem_cgroup_is_root(memcg)) { |
6053 | if (nr_mem) | |
3e32cb2e | 6054 | page_counter_uncharge(&memcg->memory, nr_mem); |
ce00a967 | 6055 | if (nr_memsw) |
3e32cb2e | 6056 | page_counter_uncharge(&memcg->memsw, nr_memsw); |
ce00a967 JW |
6057 | memcg_oom_recover(memcg); |
6058 | } | |
747db954 JW |
6059 | |
6060 | local_irq_save(flags); | |
6061 | __this_cpu_sub(memcg->stat->count[MEM_CGROUP_STAT_RSS], nr_anon); | |
6062 | __this_cpu_sub(memcg->stat->count[MEM_CGROUP_STAT_CACHE], nr_file); | |
6063 | __this_cpu_sub(memcg->stat->count[MEM_CGROUP_STAT_RSS_HUGE], nr_huge); | |
6064 | __this_cpu_add(memcg->stat->events[MEM_CGROUP_EVENTS_PGPGOUT], pgpgout); | |
6065 | __this_cpu_add(memcg->stat->nr_page_events, nr_anon + nr_file); | |
6066 | memcg_check_events(memcg, dummy_page); | |
6067 | local_irq_restore(flags); | |
e8ea14cc JW |
6068 | |
6069 | if (!mem_cgroup_is_root(memcg)) | |
6070 | css_put_many(&memcg->css, max(nr_mem, nr_memsw)); | |
747db954 JW |
6071 | } |
6072 | ||
6073 | static void uncharge_list(struct list_head *page_list) | |
6074 | { | |
6075 | struct mem_cgroup *memcg = NULL; | |
6076 | unsigned long nr_memsw = 0; | |
6077 | unsigned long nr_anon = 0; | |
6078 | unsigned long nr_file = 0; | |
6079 | unsigned long nr_huge = 0; | |
6080 | unsigned long pgpgout = 0; | |
6081 | unsigned long nr_mem = 0; | |
6082 | struct list_head *next; | |
6083 | struct page *page; | |
6084 | ||
6085 | next = page_list->next; | |
6086 | do { | |
6087 | unsigned int nr_pages = 1; | |
6088 | struct page_cgroup *pc; | |
6089 | ||
6090 | page = list_entry(next, struct page, lru); | |
6091 | next = page->lru.next; | |
6092 | ||
6093 | VM_BUG_ON_PAGE(PageLRU(page), page); | |
6094 | VM_BUG_ON_PAGE(page_count(page), page); | |
6095 | ||
6096 | pc = lookup_page_cgroup(page); | |
6097 | if (!PageCgroupUsed(pc)) | |
6098 | continue; | |
6099 | ||
6100 | /* | |
6101 | * Nobody should be changing or seriously looking at | |
6102 | * pc->mem_cgroup and pc->flags at this point, we have | |
6103 | * fully exclusive access to the page. | |
6104 | */ | |
6105 | ||
6106 | if (memcg != pc->mem_cgroup) { | |
6107 | if (memcg) { | |
6108 | uncharge_batch(memcg, pgpgout, nr_mem, nr_memsw, | |
6109 | nr_anon, nr_file, nr_huge, page); | |
6110 | pgpgout = nr_mem = nr_memsw = 0; | |
6111 | nr_anon = nr_file = nr_huge = 0; | |
6112 | } | |
6113 | memcg = pc->mem_cgroup; | |
6114 | } | |
6115 | ||
6116 | if (PageTransHuge(page)) { | |
6117 | nr_pages <<= compound_order(page); | |
6118 | VM_BUG_ON_PAGE(!PageTransHuge(page), page); | |
6119 | nr_huge += nr_pages; | |
6120 | } | |
6121 | ||
6122 | if (PageAnon(page)) | |
6123 | nr_anon += nr_pages; | |
6124 | else | |
6125 | nr_file += nr_pages; | |
6126 | ||
6127 | if (pc->flags & PCG_MEM) | |
6128 | nr_mem += nr_pages; | |
6129 | if (pc->flags & PCG_MEMSW) | |
6130 | nr_memsw += nr_pages; | |
6131 | pc->flags = 0; | |
6132 | ||
6133 | pgpgout++; | |
6134 | } while (next != page_list); | |
6135 | ||
6136 | if (memcg) | |
6137 | uncharge_batch(memcg, pgpgout, nr_mem, nr_memsw, | |
6138 | nr_anon, nr_file, nr_huge, page); | |
6139 | } | |
6140 | ||
0a31bc97 JW |
6141 | /** |
6142 | * mem_cgroup_uncharge - uncharge a page | |
6143 | * @page: page to uncharge | |
6144 | * | |
6145 | * Uncharge a page previously charged with mem_cgroup_try_charge() and | |
6146 | * mem_cgroup_commit_charge(). | |
6147 | */ | |
6148 | void mem_cgroup_uncharge(struct page *page) | |
6149 | { | |
0a31bc97 | 6150 | struct page_cgroup *pc; |
0a31bc97 JW |
6151 | |
6152 | if (mem_cgroup_disabled()) | |
6153 | return; | |
6154 | ||
747db954 | 6155 | /* Don't touch page->lru of any random page, pre-check: */ |
0a31bc97 | 6156 | pc = lookup_page_cgroup(page); |
0a31bc97 JW |
6157 | if (!PageCgroupUsed(pc)) |
6158 | return; | |
6159 | ||
747db954 JW |
6160 | INIT_LIST_HEAD(&page->lru); |
6161 | uncharge_list(&page->lru); | |
6162 | } | |
0a31bc97 | 6163 | |
747db954 JW |
6164 | /** |
6165 | * mem_cgroup_uncharge_list - uncharge a list of page | |
6166 | * @page_list: list of pages to uncharge | |
6167 | * | |
6168 | * Uncharge a list of pages previously charged with | |
6169 | * mem_cgroup_try_charge() and mem_cgroup_commit_charge(). | |
6170 | */ | |
6171 | void mem_cgroup_uncharge_list(struct list_head *page_list) | |
6172 | { | |
6173 | if (mem_cgroup_disabled()) | |
6174 | return; | |
0a31bc97 | 6175 | |
747db954 JW |
6176 | if (!list_empty(page_list)) |
6177 | uncharge_list(page_list); | |
0a31bc97 JW |
6178 | } |
6179 | ||
6180 | /** | |
6181 | * mem_cgroup_migrate - migrate a charge to another page | |
6182 | * @oldpage: currently charged page | |
6183 | * @newpage: page to transfer the charge to | |
6184 | * @lrucare: both pages might be on the LRU already | |
6185 | * | |
6186 | * Migrate the charge from @oldpage to @newpage. | |
6187 | * | |
6188 | * Both pages must be locked, @newpage->mapping must be set up. | |
6189 | */ | |
6190 | void mem_cgroup_migrate(struct page *oldpage, struct page *newpage, | |
6191 | bool lrucare) | |
6192 | { | |
0a31bc97 JW |
6193 | struct page_cgroup *pc; |
6194 | int isolated; | |
6195 | ||
6196 | VM_BUG_ON_PAGE(!PageLocked(oldpage), oldpage); | |
6197 | VM_BUG_ON_PAGE(!PageLocked(newpage), newpage); | |
6198 | VM_BUG_ON_PAGE(!lrucare && PageLRU(oldpage), oldpage); | |
6199 | VM_BUG_ON_PAGE(!lrucare && PageLRU(newpage), newpage); | |
6200 | VM_BUG_ON_PAGE(PageAnon(oldpage) != PageAnon(newpage), newpage); | |
6abb5a86 JW |
6201 | VM_BUG_ON_PAGE(PageTransHuge(oldpage) != PageTransHuge(newpage), |
6202 | newpage); | |
0a31bc97 JW |
6203 | |
6204 | if (mem_cgroup_disabled()) | |
6205 | return; | |
6206 | ||
6207 | /* Page cache replacement: new page already charged? */ | |
6208 | pc = lookup_page_cgroup(newpage); | |
6209 | if (PageCgroupUsed(pc)) | |
6210 | return; | |
6211 | ||
6212 | /* Re-entrant migration: old page already uncharged? */ | |
6213 | pc = lookup_page_cgroup(oldpage); | |
6214 | if (!PageCgroupUsed(pc)) | |
6215 | return; | |
6216 | ||
6217 | VM_BUG_ON_PAGE(!(pc->flags & PCG_MEM), oldpage); | |
6218 | VM_BUG_ON_PAGE(do_swap_account && !(pc->flags & PCG_MEMSW), oldpage); | |
6219 | ||
0a31bc97 JW |
6220 | if (lrucare) |
6221 | lock_page_lru(oldpage, &isolated); | |
6222 | ||
6223 | pc->flags = 0; | |
6224 | ||
6225 | if (lrucare) | |
6226 | unlock_page_lru(oldpage, isolated); | |
6227 | ||
6abb5a86 | 6228 | commit_charge(newpage, pc->mem_cgroup, lrucare); |
0a31bc97 JW |
6229 | } |
6230 | ||
2d11085e | 6231 | /* |
1081312f MH |
6232 | * subsys_initcall() for memory controller. |
6233 | * | |
6234 | * Some parts like hotcpu_notifier() have to be initialized from this context | |
6235 | * because of lock dependencies (cgroup_lock -> cpu hotplug) but basically | |
6236 | * everything that doesn't depend on a specific mem_cgroup structure should | |
6237 | * be initialized from here. | |
2d11085e MH |
6238 | */ |
6239 | static int __init mem_cgroup_init(void) | |
6240 | { | |
6241 | hotcpu_notifier(memcg_cpu_hotplug_callback, 0); | |
6acc8b02 | 6242 | enable_swap_cgroup(); |
bb4cc1a8 | 6243 | mem_cgroup_soft_limit_tree_init(); |
e4777496 | 6244 | memcg_stock_init(); |
2d11085e MH |
6245 | return 0; |
6246 | } | |
6247 | subsys_initcall(mem_cgroup_init); |